Unleashed v1.4

[unleashed.git] / kernel / net / ip / ip.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 1990 Mentat Inc.
 * Copyright (c) 2017 OmniTI Computer Consulting, Inc. All rights reserved.
 * Copyright (c) 2016 by Delphix. All rights reserved.
 * Copyright (c) 2018 Joyent, Inc. All rights reserved.
 */

#include <sys/types.h>
#include <sys/stream.h>
#include <sys/dlpi.h>
#include <sys/stropts.h>
#include <sys/sysmacros.h>
#include <sys/strsubr.h>
#include <sys/strlog.h>
#include <sys/strsun.h>
#include <sys/zone.h>
#define _SUN_TPI_VERSION 2
#include <sys/tihdr.h>
#include <sys/xti_inet.h>
#include <sys/ddi.h>
#include <sys/suntpi.h>
#include <sys/cmn_err.h>
#include <sys/debug.h>
#include <sys/kobj.h>
#include <sys/modctl.h>
#include <sys/atomic.h>
#include <sys/policy.h>
#include <sys/priv.h>
#include <sys/taskq.h>

#include <sys/systm.h>
#include <sys/param.h>
#include <sys/kmem.h>
#include <sys/sdt.h>
#include <sys/socket.h>
#include <sys/vtrace.h>
#include <sys/isa_defs.h>
#include <sys/mac.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <net/route.h>
#include <sys/sockio.h>
#include <netinet/in.h>
#include <net/if_dl.h>

#include <inet/common.h>
#include <inet/mi.h>
#include <inet/mib2.h>
#include <inet/nd.h>
#include <inet/arp.h>
#include <inet/snmpcom.h>
#include <inet/optcom.h>
#include <inet/kstatcom.h>

#include <netinet/igmp_var.h>
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#include <netinet/sctp.h>

#include <inet/ip.h>
#include <inet/ip_impl.h>
#include <inet/ip6.h>
#include <inet/ip6_asp.h>
#include <inet/tcp.h>
#include <inet/tcp_impl.h>
#include <inet/ip_multi.h>
#include <inet/ip_if.h>
#include <inet/ip_ire.h>
#include <inet/ip_ftable.h>
#include <inet/ip_rts.h>
#include <inet/ip_ndp.h>
#include <inet/ip_listutils.h>
#include <netinet/igmp.h>
#include <netinet/ip_mroute.h>
#include <inet/ipp_common.h>

#include <net/pfkeyv2.h>
#include <inet/sadb.h>
#include <inet/ipsec_impl.h>
#include <inet/iptun/iptun_impl.h>
#include <inet/ipdrop.h>
#include <inet/ip_netinfo.h>
#include <inet/ilb_ip.h>

#include <sys/ethernet.h>
#include <net/if_types.h>
#include <sys/cpuvar.h>

#include <ipp/ipp.h>
#include <ipp/ipp_impl.h>
#include <ipp/ipgpc/ipgpc.h>

#include <sys/pattr.h>
#include <inet/ipclassifier.h>
#include <inet/sctp_ip.h>
#include <inet/sctp/sctp_impl.h>
#include <inet/udp_impl.h>
#include <inet/rawip_impl.h>
#include <inet/rts_impl.h>

#include <sys/squeue_impl.h>
#include <inet/ip_arp.h>

#include <sys/clock_impl.h>     /* For LBOLT_FASTPATH{,64} */

/*
 * Values for squeue switch:
 * IP_SQUEUE_ENTER_NODRAIN: SQ_NODRAIN
 * IP_SQUEUE_ENTER: SQ_PROCESS
 * IP_SQUEUE_FILL: SQ_FILL
 */
int ip_squeue_enter = IP_SQUEUE_ENTER;  /* Setable in /etc/system */

int ip_squeue_flag;

/*
 * Setable in /etc/system
 */
int ip_poll_normal_ms = 100;
int ip_poll_normal_ticks = 0;
int ip_modclose_ackwait_ms = 3000;

/*
 * It would be nice to have these present only in DEBUG systems, but the
 * current design of the global symbol checking logic requires them to be
 * unconditionally present.
 */
uint_t ip_thread_data;                  /* TSD key for debug support */
krwlock_t ip_thread_rwlock;
list_t  ip_thread_list;

/*
 * Structure to represent a linked list of msgblks. Used by ip_snmp_ functions.
 */

struct listptr_s {
        mblk_t  *lp_head;       /* pointer to the head of the list */
        mblk_t  *lp_tail;       /* pointer to the tail of the list */
};

typedef struct listptr_s listptr_t;

/*
 * This is used by ip_snmp_get_mib2_ip_route_media and
 * ip_snmp_get_mib2_ip6_route_media to carry the lists of return data.
 */
typedef struct iproutedata_s {
        uint_t          ird_idx;
        uint_t          ird_flags;      /* see below */
        listptr_t       ird_route;      /* ipRouteEntryTable */
        listptr_t       ird_netmedia;   /* ipNetToMediaEntryTable */
} iproutedata_t;

/* Include ire_testhidden and IRE_IF_CLONE routes */
#define IRD_REPORT_ALL  0x01

/*
 * Synchronization notes:
 *
 * IP is a fully D_MP STREAMS module/driver. Thus it does not depend on any
 * MT level protection given by STREAMS. IP uses a combination of its own
 * internal serialization mechanism and standard Solaris locking techniques.
 * The internal serialization is per phyint.  This is used to serialize
 * plumbing operations, IPMP operations, most set ioctls, etc.
 *
 * Plumbing is a long sequence of operations involving message
 * exchanges between IP, ARP and device drivers. Many set ioctls are typically
 * involved in plumbing operations. A natural model is to serialize these
 * ioctls one per ill. For example plumbing of hme0 and qfe0 can go on in
 * parallel without any interference. But various set ioctls on hme0 are best
 * serialized, along with IPMP operations and processing of DLPI control
 * messages received from drivers on a per phyint basis. This serialization is
 * provided by the ipsq_t and primitives operating on this. Details can
 * be found in ip_if.c above the core primitives operating on ipsq_t.
 *
 * Lookups of an ipif or ill by a thread return a refheld ipif / ill.
 * Simiarly lookup of an ire by a thread also returns a refheld ire.
 * In addition ipif's and ill's referenced by the ire are also indirectly
 * refheld. Thus no ipif or ill can vanish as long as an ipif is refheld
 * directly or indirectly. For example an SIOCSLIFADDR ioctl that changes the
 * address of an ipif has to go through the ipsq_t. This ensures that only
 * one such exclusive operation proceeds at any time on the ipif. It then
 * waits for all refcnts
 * associated with this ipif to come down to zero. The address is changed
 * only after the ipif has been quiesced. Then the ipif is brought up again.
 * More details are described above the comment in ip_sioctl_flags.
 *
 * Packet processing is based mostly on IREs and are fully multi-threaded
 * using standard Solaris MT techniques.
 *
 * There are explicit locks in IP to handle:
 * - The ip_g_head list maintained by mi_open_link() and friends.
 *
 * - The reassembly data structures (one lock per hash bucket)
 *
 * - conn_lock is meant to protect conn_t fields. The fields actually
 *   protected by conn_lock are documented in the conn_t definition.
 *
 * - ire_lock to protect some of the fields of the ire, IRE tables
 *   (one lock per hash bucket). Refer to ip_ire.c for details.
 *
 * - ndp_g_lock and ncec_lock for protecting NCEs.
 *
 * - ill_lock protects fields of the ill and ipif. Details in ip.h
 *
 * - ill_g_lock: This is a global reader/writer lock. Protects the following
 *      * The AVL tree based global multi list of all ills.
 *      * The linked list of all ipifs of an ill
 *      * The <ipsq-xop> mapping
 *      * <ill-phyint> association
 *   Insertion/deletion of an ill in the system, insertion/deletion of an ipif
 *   into an ill, changing the <ipsq-xop> mapping of an ill, changing the
 *   <ill-phyint> assoc of an ill will all have to hold the ill_g_lock as
 *   writer for the actual duration of the insertion/deletion/change.
 *
 * - ill_lock:  This is a per ill mutex.
 *   It protects some members of the ill_t struct; see ip.h for details.
 *   It also protects the <ill-phyint> assoc.
 *   It also protects the list of ipifs hanging off the ill.
 *
 * - ipsq_lock: This is a per ipsq_t mutex lock.
 *   This protects some members of the ipsq_t struct; see ip.h for details.
 *   It also protects the <ipsq-ipxop> mapping
 *
 * - ipx_lock: This is a per ipxop_t mutex lock.
 *   This protects some members of the ipxop_t struct; see ip.h for details.
 *
 * - phyint_lock: This is a per phyint mutex lock. Protects just the
 *   phyint_flags
 *
 * - ip_addr_avail_lock: This is used to ensure the uniqueness of IP addresses.
 *   This lock is held in ipif_up_done and the ipif is marked IPIF_UP and the
 *   uniqueness check also done atomically.
 *
 * - ill_g_usesrc_lock: This readers/writer lock protects the usesrc
 *   group list linked by ill_usesrc_grp_next. It also protects the
 *   ill_usesrc_ifindex field. It is taken as a writer when a member of the
 *   group is being added or deleted.  This lock is taken as a reader when
 *   walking the list/group(eg: to get the number of members in a usesrc group).
 *   Note, it is only necessary to take this lock if the ill_usesrc_grp_next
 *   field is changing state i.e from NULL to non-NULL or vice-versa. For
 *   example, it is not necessary to take this lock in the initial portion
 *   of ip_sioctl_slifusesrc or at all in ip_sioctl_flags since these
 *   operations are executed exclusively and that ensures that the "usesrc
 *   group state" cannot change. The "usesrc group state" change can happen
 *   only in the latter part of ip_sioctl_slifusesrc and in ill_delete.
 *
 * Changing <ill-phyint>, <ipsq-xop> assocications:
 *
 * To change the <ill-phyint> association, the ill_g_lock must be held
 * as writer, and the ill_locks of both the v4 and v6 instance of the ill
 * must be held.
 *
 * To change the <ipsq-xop> association, the ill_g_lock must be held as
 * writer, the ipsq_lock must be held, and one must be writer on the ipsq.
 * This is only done when ills are added or removed from IPMP groups.
 *
 * To add or delete an ipif from the list of ipifs hanging off the ill,
 * ill_g_lock (writer) and ill_lock must be held and the thread must be
 * a writer on the associated ipsq.
 *
 * To add or delete an ill to the system, the ill_g_lock must be held as
 * writer and the thread must be a writer on the associated ipsq.
 *
 * To add or delete an ilm to an ill, the ill_lock must be held and the thread
 * must be a writer on the associated ipsq.
 *
 * Lock hierarchy
 *
 * Some lock hierarchy scenarios are listed below.
 *
 * ill_g_lock -> conn_lock -> ill_lock -> ipsq_lock -> ipx_lock
 * ill_g_lock -> ill_lock(s) -> phyint_lock
 * ill_g_lock -> ndp_g_lock -> ill_lock -> ncec_lock
 * ill_g_lock -> ip_addr_avail_lock
 * conn_lock -> irb_lock -> ill_lock -> ire_lock
 * ill_g_lock -> ip_g_nd_lock
 * ill_g_lock -> ips_ipmp_lock -> ill_lock -> nce_lock
 * ill_g_lock -> ndp_g_lock -> ill_lock -> ncec_lock -> nce_lock
 * arl_lock -> ill_lock
 * ips_ire_dep_lock -> irb_lock
 *
 * When more than 1 ill lock is needed to be held, all ill lock addresses
 * are sorted on address and locked starting from highest addressed lock
 * downward.
 *
 * Multicast scenarios
 * ips_ill_g_lock -> ill_mcast_lock
 * conn_ilg_lock -> ips_ill_g_lock -> ill_lock
 * ill_mcast_serializer -> ill_mcast_lock -> ips_ipmp_lock -> ill_lock
 * ill_mcast_serializer -> ill_mcast_lock -> connf_lock -> conn_lock
 * ill_mcast_serializer -> ill_mcast_lock -> conn_ilg_lock
 * ill_mcast_serializer -> ill_mcast_lock -> ips_igmp_timer_lock
 *
 * IPsec scenarios
 *
 * ipsa_lock -> ill_g_lock -> ill_lock
 * ill_g_usesrc_lock -> ill_g_lock -> ill_lock
 *
 * squeue(sq_lock), flow related (ft_lock, fe_lock) locking
 *
 * cpu_lock --> ill_lock --> sqset_lock --> sq_lock
 * sq_lock -> conn_lock -> QLOCK(q)
 * ill_lock -> ft_lock -> fe_lock
 *
 * Routing/forwarding table locking notes:
 *
 * Lock acquisition order: Radix tree lock, irb_lock.
 * Requirements:
 * i.  Walker must not hold any locks during the walker callback.
 * ii  Walker must not see a truncated tree during the walk because of any node
 *     deletion.
 * iii Existing code assumes ire_bucket is valid if it is non-null and is used
 *     in many places in the code to walk the irb list. Thus even if all the
 *     ires in a bucket have been deleted, we still can't free the radix node
 *     until the ires have actually been inactive'd (freed).
 *
 * Tree traversal - Need to hold the global tree lock in read mode.
 * Before dropping the global tree lock, need to either increment the ire_refcnt
 * to ensure that the radix node can't be deleted.
 *
 * Tree add - Need to hold the global tree lock in write mode to add a
 * radix node. To prevent the node from being deleted, increment the
 * irb_refcnt, after the node is added to the tree. The ire itself is
 * added later while holding the irb_lock, but not the tree lock.
 *
 * Tree delete - Need to hold the global tree lock and irb_lock in write mode.
 * All associated ires must be inactive (i.e. freed), and irb_refcnt
 * must be zero.
 *
 * Walker - Increment irb_refcnt before calling the walker callback. Hold the
 * global tree lock (read mode) for traversal.
 *
 * IRE dependencies - In some cases we hold ips_ire_dep_lock across ire_refrele
 * hence we will acquire irb_lock while holding ips_ire_dep_lock.
 *
 * IPsec notes :
 *
 * IP interacts with the IPsec code (AH/ESP) by storing IPsec attributes
 * in the ip_xmit_attr_t ip_recv_attr_t. For outbound datagrams, the
 * ip_xmit_attr_t has the
 * information used by the IPsec code for applying the right level of
 * protection. The information initialized by IP in the ip_xmit_attr_t
 * is determined by the per-socket policy or global policy in the system.
 * For inbound datagrams, the ip_recv_attr_t
 * starts out with nothing in it. It gets filled
 * with the right information if it goes through the AH/ESP code, which
 * happens if the incoming packet is secure. The information initialized
 * by AH/ESP, is later used by IP (during fanouts to ULP) to see whether
 * the policy requirements needed by per-socket policy or global policy
 * is met or not.
 *
 * For fully connected sockets i.e dst, src [addr, port] is known,
 * conn_policy_cached is set indicating that policy has been cached.
 * conn_in_enforce_policy may or may not be set depending on whether
 * there is a global policy match or per-socket policy match.
 * Policy inheriting happpens in ip_policy_set once the destination is known.
 * Once the right policy is set on the conn_t, policy cannot change for
 * this socket. This makes life simpler for TCP (UDP ?) where
 * re-transmissions go out with the same policy. For symmetry, policy
 * is cached for fully connected UDP sockets also. Thus if policy is cached,
 * it also implies that policy is latched i.e policy cannot change
 * on these sockets. As we have the right policy on the conn, we don't
 * have to lookup global policy for every outbound and inbound datagram
 * and thus serving as an optimization. Note that a global policy change
 * does not affect fully connected sockets if they have policy. If fully
 * connected sockets did not have any policy associated with it, global
 * policy change may affect them.
 *
 * IP Flow control notes:
 * ---------------------
 * Non-TCP streams are flow controlled by IP. The way this is accomplished
 * differs when ILL_CAPAB_DLD_DIRECT is enabled for that IP instance. When
 * ILL_DIRECT_CAPABLE(ill) is TRUE, IP can do direct function calls into
 * GLDv3. Otherwise packets are sent down to lower layers using STREAMS
 * functions.
 *
 * Per Tx ring udp flow control:
 * This is applicable only when ILL_CAPAB_DLD_DIRECT capability is set in
 * the ill (i.e. ILL_DIRECT_CAPABLE(ill) is true).
 *
 * The underlying link can expose multiple Tx rings to the GLDv3 mac layer.
 * To achieve best performance, outgoing traffic need to be fanned out among
 * these Tx ring. mac_tx() is called (via str_mdata_fastpath_put()) to send
 * traffic out of the NIC and it takes a fanout hint. UDP connections pass
 * the address of connp as fanout hint to mac_tx(). Under flow controlled
 * condition, mac_tx() returns a non-NULL cookie (ip_mac_tx_cookie_t). This
 * cookie points to a specific Tx ring that is blocked. The cookie is used to
 * hash into an idl_tx_list[] entry in idl_tx_list[] array. Each idl_tx_list_t
 * point to drain_lists (idl_t's). These drain list will store the blocked UDP
 * connp's. The drain list is not a single list but a configurable number of
 * lists.
 *
 * The diagram below shows idl_tx_list_t's and their drain_lists. ip_stack_t
 * has an array of idl_tx_list_t. The size of the array is TX_FANOUT_SIZE
 * which is equal to 128. This array in turn contains a pointer to idl_t[],
 * the ip drain list. The idl_t[] array size is MIN(max_ncpus, 8). The drain
 * list will point to the list of connp's that are flow controlled.
 *
 *                      ---------------   -------   -------   -------
 *                   |->|drain_list[0]|-->|connp|-->|connp|-->|connp|-->
 *                   |  ---------------   -------   -------   -------
 *                   |  ---------------   -------   -------   -------
 *                   |->|drain_list[1]|-->|connp|-->|connp|-->|connp|-->
 * ----------------  |  ---------------   -------   -------   -------
 * |idl_tx_list[0]|->|  ---------------   -------   -------   -------
 * ----------------  |->|drain_list[2]|-->|connp|-->|connp|-->|connp|-->
 *                   |  ---------------   -------   -------   -------
 *                   .        .              .         .         .
 *                   |  ---------------   -------   -------   -------
 *                   |->|drain_list[n]|-->|connp|-->|connp|-->|connp|-->
 *                      ---------------   -------   -------   -------
 *                      ---------------   -------   -------   -------
 *                   |->|drain_list[0]|-->|connp|-->|connp|-->|connp|-->
 *                   |  ---------------   -------   -------   -------
 *                   |  ---------------   -------   -------   -------
 * ----------------  |->|drain_list[1]|-->|connp|-->|connp|-->|connp|-->
 * |idl_tx_list[1]|->|  ---------------   -------   -------   -------
 * ----------------  |        .              .         .         .
 *                   |  ---------------   -------   -------   -------
 *                   |->|drain_list[n]|-->|connp|-->|connp|-->|connp|-->
 *                      ---------------   -------   -------   -------
 *     .....
 * ----------------
 * |idl_tx_list[n]|-> ...
 * ----------------
 *
 * When mac_tx() returns a cookie, the cookie is hashed into an index into
 * ips_idl_tx_list[], and conn_drain_insert() is called with the idl_tx_list
 * to insert the conn onto.  conn_drain_insert() asserts flow control for the
 * sockets via su_txq_full() (non-STREAMS) or QFULL on conn_wq (STREAMS).
 * Further, conn_blocked is set to indicate that the conn is blocked.
 *
 * GLDv3 calls ill_flow_enable() when flow control is relieved.  The cookie
 * passed in the call to ill_flow_enable() identifies the blocked Tx ring and
 * is again hashed to locate the appropriate idl_tx_list, which is then
 * drained via conn_walk_drain().  conn_walk_drain() goes through each conn in
 * the drain list and calls conn_drain_remove() to clear flow control (via
 * calling su_txq_full() or clearing QFULL), and remove the conn from the
 * drain list.
 *
 * Note that the drain list is not a single list but a (configurable) array of
 * lists (8 elements by default).  Synchronization between drain insertion and
 * flow control wakeup is handled by using idl_txl->txl_lock, and only
 * conn_drain_insert() and conn_drain_remove() manipulate the drain list.
 *
 * Flow control via STREAMS is used when ILL_DIRECT_CAPABLE() returns FALSE.
 * On the send side, if the packet cannot be sent down to the driver by IP
 * (canput() fails), ip_xmit() drops the packet and returns EWOULDBLOCK to the
 * caller, who may then invoke ixa_check_drain_insert() to insert the conn on
 * the 0'th drain list.  When ip_wsrv() runs on the ill_wq because flow
 * control has been relieved, the blocked conns in the 0'th drain list are
 * drained as in the non-STREAMS case.
 *
 * In both the STREAMS and non-STREAMS cases, the sockfs upcall to set QFULL
 * is done when the conn is inserted into the drain list (conn_drain_insert())
 * and cleared when the conn is removed from the it (conn_drain_remove()).
 *
 * IPQOS notes:
 *
 * IPQoS Policies are applied to packets using IPPF (IP Policy framework)
 * and IPQoS modules. IPPF includes hooks in IP at different control points
 * (callout positions) which direct packets to IPQoS modules for policy
 * processing. Policies, if present, are global.
 *
 * The callout positions are located in the following paths:
 *              o local_in (packets destined for this host)
 *              o local_out (packets orginating from this host )
 *              o fwd_in  (packets forwarded by this m/c - inbound)
 *              o fwd_out (packets forwarded by this m/c - outbound)
 * Hooks at these callout points can be enabled/disabled using the ndd variable
 * ip_policy_mask (a bit mask with the 4 LSB indicating the callout positions).
 * By default all the callout positions are enabled.
 *
 * Outbound (local_out)
 * Hooks are placed in ire_send_wire_v4 and ire_send_wire_v6.
 *
 * Inbound (local_in)
 * Hooks are placed in ip_fanout_v4 and ip_fanout_v6.
 *
 * Forwarding (in and out)
 * Hooks are placed in ire_recv_forward_v4/v6.
 *
 * IP Policy Framework processing (IPPF processing)
 * Policy processing for a packet is initiated by ip_process, which ascertains
 * that the classifier (ipgpc) is loaded and configured, failing which the
 * packet resumes normal processing in IP. If the clasifier is present, the
 * packet is acted upon by one or more IPQoS modules (action instances), per
 * filters configured in ipgpc and resumes normal IP processing thereafter.
 * An action instance can drop a packet in course of its processing.
 *
 * Zones notes:
 *
 * The partitioning rules for networking are as follows:
 * 1) Packets coming from a zone must have a source address belonging to that
 * zone.
 * 2) Packets coming from a zone can only be sent on a physical interface on
 * which the zone has an IP address.
 * 3) Between two zones on the same machine, packet delivery is only allowed if
 * there's a matching route for the destination and zone in the forwarding
 * table.
 * 4) The TCP and UDP port spaces are per-zone; that is, two processes in
 * different zones can bind to the same port with the wildcard address
 * (INADDR_ANY).
 *
 * The granularity of interface partitioning is at the logical interface level.
 * Therefore, every zone has its own IP addresses, and incoming packets can be
 * attributed to a zone unambiguously. A logical interface is placed into a zone
 * using the SIOCSLIFZONE ioctl; this sets the ipif_zoneid field in the ipif_t
 * structure. Rule (1) is implemented by modifying the source address selection
 * algorithm so that the list of eligible addresses is filtered based on the
 * sending process zone.
 *
 * The Internet Routing Entries (IREs) are either exclusive to a zone or shared
 * across all zones, depending on their type. Here is the break-up:
 *
 * IRE type                             Shared/exclusive
 * --------                             ----------------
 * IRE_BROADCAST                        Exclusive
 * IRE_DEFAULT (default routes)         Shared (*)
 * IRE_LOCAL                            Exclusive (x)
 * IRE_LOOPBACK                         Exclusive
 * IRE_PREFIX (net routes)              Shared (*)
 * IRE_IF_NORESOLVER (interface routes) Exclusive
 * IRE_IF_RESOLVER (interface routes)   Exclusive
 * IRE_IF_CLONE (interface routes)      Exclusive
 * IRE_HOST (host routes)               Shared (*)
 *
 * (*) A zone can only use a default or off-subnet route if the gateway is
 * directly reachable from the zone, that is, if the gateway's address matches
 * one of the zone's logical interfaces.
 *
 * (x) IRE_LOCAL are handled a bit differently.
 * When ip_restrict_interzone_loopback is set (the default),
 * ire_route_recursive restricts loopback using an IRE_LOCAL
 * between zone to the case when L2 would have conceptually looped the packet
 * back, i.e. the loopback which is required since neither Ethernet drivers
 * nor Ethernet hardware loops them back. This is the case when the normal
 * routes (ignoring IREs with different zoneids) would send out the packet on
 * the same ill as the ill with which is IRE_LOCAL is associated.
 *
 * Multiple zones can share a common broadcast address; typically all zones
 * share the 255.255.255.255 address. Incoming as well as locally originated
 * broadcast packets must be dispatched to all the zones on the broadcast
 * network. For directed broadcasts (e.g. 10.16.72.255) this is not trivial
 * since some zones may not be on the 10.16.72/24 network. To handle this, each
 * zone has its own set of IRE_BROADCAST entries; then, broadcast packets are
 * sent to every zone that has an IRE_BROADCAST entry for the destination
 * address on the input ill, see ip_input_broadcast().
 *
 * Applications in different zones can join the same multicast group address.
 * The same logic applies for multicast as for broadcast. ip_input_multicast
 * dispatches packets to all zones that have members on the physical interface.
 */

/*
 * Squeue Fanout flags:
 *      0: No fanout.
 *      1: Fanout across all squeues
 */
boolean_t       ip_squeue_fanout = 0;

/*
 * Maximum dups allowed per packet.
 */
uint_t ip_max_frag_dups = 10;

static int      ip_open(queue_t *q, dev_t *devp, int flag, int sflag,
                    cred_t *credp, boolean_t isv6);
static mblk_t   *ip_xmit_attach_llhdr(mblk_t *, nce_t *);

static boolean_t icmp_inbound_verify_v4(mblk_t *, icmph_t *, ip_recv_attr_t *);
static void     icmp_inbound_too_big_v4(icmph_t *, ip_recv_attr_t *);
static void     icmp_inbound_error_fanout_v4(mblk_t *, icmph_t *,
    ip_recv_attr_t *);
static void     icmp_options_update(ipha_t *);
static void     icmp_param_problem(mblk_t *, uint8_t,  ip_recv_attr_t *);
static void     icmp_pkt(mblk_t *, void *, size_t, ip_recv_attr_t *);
static mblk_t   *icmp_pkt_err_ok(mblk_t *, ip_recv_attr_t *);
static void     icmp_redirect_v4(mblk_t *mp, ipha_t *, icmph_t *,
    ip_recv_attr_t *);
static void     icmp_send_redirect(mblk_t *, ipaddr_t, ip_recv_attr_t *);
static void     icmp_send_reply_v4(mblk_t *, ipha_t *, icmph_t *,
    ip_recv_attr_t *);

mblk_t          *ip_dlpi_alloc(size_t, t_uscalar_t);
char            *ip_dot_addr(ipaddr_t, char *);
mblk_t          *ip_carve_mp(mblk_t **, ssize_t);
static char     *ip_dot_saddr(uchar_t *, char *);
static int      ip_lrput(queue_t *, mblk_t *);
ipaddr_t        ip_net_mask(ipaddr_t);
char            *ip_nv_lookup(nv_t *, int);
int             ip_rput(queue_t *, mblk_t *);
static void     ip_rput_dlpi_writer(ipsq_t *dummy_sq, queue_t *q, mblk_t *mp,
                    void *dummy_arg);
int             ip_snmp_get(queue_t *, mblk_t *, int, boolean_t);
static mblk_t   *ip_snmp_get_mib2_ip(queue_t *, mblk_t *,
                    mib2_ipIfStatsEntry_t *, ip_stack_t *, boolean_t);
static mblk_t   *ip_snmp_get_mib2_ip_traffic_stats(queue_t *, mblk_t *,
                    ip_stack_t *, boolean_t);
static mblk_t   *ip_snmp_get_mib2_ip6(queue_t *, mblk_t *, ip_stack_t *,
                    boolean_t);
static mblk_t   *ip_snmp_get_mib2_icmp(queue_t *, mblk_t *, ip_stack_t *ipst);
static mblk_t   *ip_snmp_get_mib2_icmp6(queue_t *, mblk_t *, ip_stack_t *ipst);
static mblk_t   *ip_snmp_get_mib2_igmp(queue_t *, mblk_t *, ip_stack_t *ipst);
static mblk_t   *ip_snmp_get_mib2_multi(queue_t *, mblk_t *, ip_stack_t *ipst);
static mblk_t   *ip_snmp_get_mib2_ip_addr(queue_t *, mblk_t *,
                    ip_stack_t *ipst, boolean_t);
static mblk_t   *ip_snmp_get_mib2_ip6_addr(queue_t *, mblk_t *,
                    ip_stack_t *ipst, boolean_t);
static mblk_t   *ip_snmp_get_mib2_ip_group_src(queue_t *, mblk_t *,
                    ip_stack_t *ipst);
static mblk_t   *ip_snmp_get_mib2_ip6_group_src(queue_t *, mblk_t *,
                    ip_stack_t *ipst);
static mblk_t   *ip_snmp_get_mib2_ip_group_mem(queue_t *, mblk_t *,
                    ip_stack_t *ipst);
static mblk_t   *ip_snmp_get_mib2_ip6_group_mem(queue_t *, mblk_t *,
                    ip_stack_t *ipst);
static mblk_t   *ip_snmp_get_mib2_virt_multi(queue_t *, mblk_t *,
                    ip_stack_t *ipst);
static mblk_t   *ip_snmp_get_mib2_multi_rtable(queue_t *, mblk_t *,
                    ip_stack_t *ipst);
static mblk_t   *ip_snmp_get_mib2_ip_route_media(queue_t *, mblk_t *, int,
                    ip_stack_t *ipst);
static mblk_t   *ip_snmp_get_mib2_ip6_route_media(queue_t *, mblk_t *, int,
                    ip_stack_t *ipst);
static void     ip_snmp_get2_v4(ire_t *, iproutedata_t *);
static void     ip_snmp_get2_v6_route(ire_t *, iproutedata_t *);
static void     ip_snmp_get2_v4_media(ncec_t *, void *);
static void     ip_snmp_get2_v6_media(ncec_t *, void *);
int             ip_snmp_set(queue_t *, int, int, uchar_t *, int);

static mblk_t   *ip_fragment_copyhdr(uchar_t *, int, int, ip_stack_t *,
                    mblk_t *);

static void     conn_drain_init(ip_stack_t *);
static void     conn_drain_fini(ip_stack_t *);
static void     conn_drain(conn_t *connp, boolean_t closing);

static void     conn_walk_drain(ip_stack_t *, idl_tx_list_t *);
static void     conn_walk_sctp(pfv_t, void *, zoneid_t, netstack_t *);

static void     *ip_stack_init(netstackid_t stackid, netstack_t *ns);
static void     ip_stack_shutdown(netstackid_t stackid, void *arg);
static void     ip_stack_fini(netstackid_t stackid, void *arg);

static int      ip_squeue_switch(int);

static void     *ip_kstat_init(netstackid_t, ip_stack_t *);
static void     ip_kstat_fini(netstackid_t, kstat_t *);
static int      ip_kstat_update(kstat_t *kp, int rw);
static void     *icmp_kstat_init(netstackid_t);
static void     icmp_kstat_fini(netstackid_t, kstat_t *);
static int      icmp_kstat_update(kstat_t *kp, int rw);
static void     *ip_kstat2_init(netstackid_t, ip_stat_t *);
static void     ip_kstat2_fini(netstackid_t, kstat_t *);

static void     ipobs_init(ip_stack_t *);
static void     ipobs_fini(ip_stack_t *);

static int      ip_tp_cpu_update(cpu_setup_t, int, void *);

ipaddr_t        ip_g_all_ones = IP_HOST_MASK;

static long ip_rput_pullups;
int     dohwcksum = 1;  /* use h/w cksum if supported by the hardware */

vmem_t *ip_minor_arena_sa; /* for minor nos. from INET_MIN_DEV+2 thru 2^^18-1 */
vmem_t *ip_minor_arena_la; /* for minor nos. from 2^^18 thru 2^^32-1 */

int     ip_debug;

/*
 * IP tunables related declarations. Definitions are in ip_tunables.c
 */
extern mod_prop_info_t ip_propinfo_tbl[];
extern int ip_propinfo_count;

/*
 * Table of IP ioctls encoding the various properties of the ioctl and
 * indexed based on the last byte of the ioctl command. Occasionally there
 * is a clash, and there is more than 1 ioctl with the same last byte.
 * In such a case 1 ioctl is encoded in the ndx table and the remaining
 * ioctls are encoded in the misc table. An entry in the ndx table is
 * retrieved by indexing on the last byte of the ioctl command and comparing
 * the ioctl command with the value in the ndx table. In the event of a
 * mismatch the misc table is then searched sequentially for the desired
 * ioctl command.
 *
 * Entry: <command> <copyin_size> <flags> <cmd_type> <function> <restart_func>
 */
ip_ioctl_cmd_t ip_ndx_ioctl_table[] = {
        /* 000 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 001 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 002 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 003 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 004 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 005 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 006 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 007 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 008 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 009 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

        /* 010 */ { SIOCADDRT,  sizeof (struct rtentry), IPI_PRIV,
                        MISC_CMD, ip_siocaddrt, NULL },
        /* 011 */ { SIOCDELRT,  sizeof (struct rtentry), IPI_PRIV,
                        MISC_CMD, ip_siocdelrt, NULL },

        /* 012 */ { SIOCSIFADDR, sizeof (struct ifreq), IPI_PRIV | IPI_WR,
                        IF_CMD, ip_sioctl_addr, ip_sioctl_addr_restart },
        /* 013 */ { SIOCGIFADDR, sizeof (struct ifreq), IPI_GET_CMD,
                        IF_CMD, ip_sioctl_get_addr, NULL },

        /* 014 */ { SIOCSIFDSTADDR, sizeof (struct ifreq), IPI_PRIV | IPI_WR,
                        IF_CMD, ip_sioctl_dstaddr, ip_sioctl_dstaddr_restart },
        /* 015 */ { SIOCGIFDSTADDR, sizeof (struct ifreq),
                        IPI_GET_CMD, IF_CMD, ip_sioctl_get_dstaddr, NULL },

        /* 016 */ { SIOCSIFFLAGS, sizeof (struct ifreq),
                        IPI_PRIV | IPI_WR,
                        IF_CMD, ip_sioctl_flags, ip_sioctl_flags_restart },
        /* 017 */ { SIOCGIFFLAGS, sizeof (struct ifreq),
                        IPI_MODOK | IPI_GET_CMD,
                        IF_CMD, ip_sioctl_get_flags, NULL },

        /* 018 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 019 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

        /* copyin size cannot be coded for SIOCGIFCONF */
        /* 020 */ { O_SIOCGIFCONF, 0, IPI_GET_CMD,
                        MISC_CMD, ip_sioctl_get_ifconf, NULL },

        /* 021 */ { SIOCSIFMTU, sizeof (struct ifreq), IPI_PRIV | IPI_WR,
                        IF_CMD, ip_sioctl_mtu, NULL },
        /* 022 */ { SIOCGIFMTU, sizeof (struct ifreq), IPI_GET_CMD,
                        IF_CMD, ip_sioctl_get_mtu, NULL },
        /* 023 */ { SIOCGIFBRDADDR, sizeof (struct ifreq),
                        IPI_GET_CMD, IF_CMD, ip_sioctl_get_brdaddr, NULL },
        /* 024 */ { SIOCSIFBRDADDR, sizeof (struct ifreq), IPI_PRIV | IPI_WR,
                        IF_CMD, ip_sioctl_brdaddr, NULL },
        /* 025 */ { SIOCGIFNETMASK, sizeof (struct ifreq),
                        IPI_GET_CMD, IF_CMD, ip_sioctl_get_netmask, NULL },
        /* 026 */ { SIOCSIFNETMASK, sizeof (struct ifreq), IPI_PRIV | IPI_WR,
                        IF_CMD, ip_sioctl_netmask, ip_sioctl_netmask_restart },
        /* 027 */ { SIOCGIFMETRIC, sizeof (struct ifreq),
                        IPI_GET_CMD, IF_CMD, ip_sioctl_get_metric, NULL },
        /* 028 */ { SIOCSIFMETRIC, sizeof (struct ifreq), IPI_PRIV,
                        IF_CMD, ip_sioctl_metric, NULL },
        /* 029 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

        /* See 166-168 below for extended SIOC*XARP ioctls */
        /* 030 */ { SIOCSARP, sizeof (struct arpreq), IPI_PRIV | IPI_WR,
                        ARP_CMD, ip_sioctl_arp, NULL },
        /* 031 */ { SIOCGARP, sizeof (struct arpreq), IPI_GET_CMD,
                        ARP_CMD, ip_sioctl_arp, NULL },
        /* 032 */ { SIOCDARP, sizeof (struct arpreq), IPI_PRIV | IPI_WR,
                        ARP_CMD, ip_sioctl_arp, NULL },

        /* 033 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 034 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 035 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 036 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 037 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 038 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 039 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 040 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 041 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 042 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 043 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 044 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 045 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 046 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 047 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 048 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 049 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 050 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 051 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 052 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 053 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

        /* 054 */ { IF_UNITSEL, sizeof (int), IPI_PRIV | IPI_WR | IPI_MODOK,
                        MISC_CMD, if_unitsel, if_unitsel_restart },

        /* 055 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 056 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 057 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 058 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 059 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 060 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 061 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 062 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 063 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 064 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 065 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 066 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 067 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 068 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 069 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 070 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 071 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 072 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

        /* 073 */ { SIOCSIFNAME, sizeof (struct ifreq),
                        IPI_PRIV | IPI_WR | IPI_MODOK,
                        IF_CMD, ip_sioctl_sifname, NULL },

        /* 074 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 075 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 076 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 077 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 078 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 079 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 080 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 081 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 082 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 083 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 084 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 085 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 086 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

        /* 087 */ { SIOCGIFNUM, sizeof (int), IPI_GET_CMD,
                        MISC_CMD, ip_sioctl_get_ifnum, NULL },
        /* 088 */ { SIOCGIFMUXID, sizeof (struct ifreq), IPI_GET_CMD,
                        IF_CMD, ip_sioctl_get_muxid, NULL },
        /* 089 */ { SIOCSIFMUXID, sizeof (struct ifreq),
                        IPI_PRIV | IPI_WR, IF_CMD, ip_sioctl_muxid, NULL },

        /* Both if and lif variants share same func */
        /* 090 */ { SIOCGIFINDEX, sizeof (struct ifreq), IPI_GET_CMD,
                        IF_CMD, ip_sioctl_get_lifindex, NULL },
        /* Both if and lif variants share same func */
        /* 091 */ { SIOCSIFINDEX, sizeof (struct ifreq),
                        IPI_PRIV | IPI_WR, IF_CMD, ip_sioctl_slifindex, NULL },

        /* copyin size cannot be coded for SIOCGIFCONF */
        /* 092 */ { SIOCGIFCONF, 0, IPI_GET_CMD,
                        MISC_CMD, ip_sioctl_get_ifconf, NULL },
        /* 093 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 094 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 095 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 096 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 097 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 098 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 099 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 100 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 101 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 102 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 103 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 104 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 105 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 106 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 107 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 108 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 109 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

        /* 110 */ { SIOCLIFREMOVEIF, sizeof (struct lifreq),
                        IPI_PRIV | IPI_WR, LIF_CMD, ip_sioctl_removeif,
                        ip_sioctl_removeif_restart },
        /* 111 */ { SIOCLIFADDIF, sizeof (struct lifreq),
                        IPI_GET_CMD | IPI_PRIV | IPI_WR,
                        LIF_CMD, ip_sioctl_addif, NULL },
#define SIOCLIFADDR_NDX 112
        /* 112 */ { SIOCSLIFADDR, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
                        LIF_CMD, ip_sioctl_addr, ip_sioctl_addr_restart },
        /* 113 */ { SIOCGLIFADDR, sizeof (struct lifreq),
                        IPI_GET_CMD, LIF_CMD, ip_sioctl_get_addr, NULL },
        /* 114 */ { SIOCSLIFDSTADDR, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
                        LIF_CMD, ip_sioctl_dstaddr, ip_sioctl_dstaddr_restart },
        /* 115 */ { SIOCGLIFDSTADDR, sizeof (struct lifreq),
                        IPI_GET_CMD, LIF_CMD, ip_sioctl_get_dstaddr, NULL },
        /* 116 */ { SIOCSLIFFLAGS, sizeof (struct lifreq),
                        IPI_PRIV | IPI_WR,
                        LIF_CMD, ip_sioctl_flags, ip_sioctl_flags_restart },
        /* 117 */ { SIOCGLIFFLAGS, sizeof (struct lifreq),
                        IPI_GET_CMD | IPI_MODOK,
                        LIF_CMD, ip_sioctl_get_flags, NULL },

        /* 118 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 119 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

        /* 120 */ { O_SIOCGLIFCONF, 0, IPI_GET_CMD, MISC_CMD,
                        ip_sioctl_get_lifconf, NULL },
        /* 121 */ { SIOCSLIFMTU, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
                        LIF_CMD, ip_sioctl_mtu, NULL },
        /* 122 */ { SIOCGLIFMTU, sizeof (struct lifreq), IPI_GET_CMD,
                        LIF_CMD, ip_sioctl_get_mtu, NULL },
        /* 123 */ { SIOCGLIFBRDADDR, sizeof (struct lifreq),
                        IPI_GET_CMD, LIF_CMD, ip_sioctl_get_brdaddr, NULL },
        /* 124 */ { SIOCSLIFBRDADDR, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
                        LIF_CMD, ip_sioctl_brdaddr, NULL },
        /* 125 */ { SIOCGLIFNETMASK, sizeof (struct lifreq),
                        IPI_GET_CMD, LIF_CMD, ip_sioctl_get_netmask, NULL },
        /* 126 */ { SIOCSLIFNETMASK, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
                        LIF_CMD, ip_sioctl_netmask, ip_sioctl_netmask_restart },
        /* 127 */ { SIOCGLIFMETRIC, sizeof (struct lifreq),
                        IPI_GET_CMD, LIF_CMD, ip_sioctl_get_metric, NULL },
        /* 128 */ { SIOCSLIFMETRIC, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
                        LIF_CMD, ip_sioctl_metric, NULL },
        /* 129 */ { SIOCSLIFNAME, sizeof (struct lifreq),
                        IPI_PRIV | IPI_WR | IPI_MODOK,
                        LIF_CMD, ip_sioctl_slifname,
                        ip_sioctl_slifname_restart },

        /* 130 */ { SIOCGLIFNUM, sizeof (struct lifnum), IPI_GET_CMD,
                        MISC_CMD, ip_sioctl_get_lifnum, NULL },
        /* 131 */ { SIOCGLIFMUXID, sizeof (struct lifreq),
                        IPI_GET_CMD, LIF_CMD, ip_sioctl_get_muxid, NULL },
        /* 132 */ { SIOCSLIFMUXID, sizeof (struct lifreq),
                        IPI_PRIV | IPI_WR, LIF_CMD, ip_sioctl_muxid, NULL },
        /* 133 */ { SIOCGLIFINDEX, sizeof (struct lifreq),
                        IPI_GET_CMD, LIF_CMD, ip_sioctl_get_lifindex, 0 },
        /* 134 */ { SIOCSLIFINDEX, sizeof (struct lifreq),
                        IPI_PRIV | IPI_WR, LIF_CMD, ip_sioctl_slifindex, 0 },
        /* 135 */ { SIOCSLIFTOKEN, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
                        LIF_CMD, ip_sioctl_token, NULL },
        /* 136 */ { SIOCGLIFTOKEN, sizeof (struct lifreq),
                        IPI_GET_CMD, LIF_CMD, ip_sioctl_get_token, NULL },
        /* 137 */ { SIOCSLIFSUBNET, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
                        LIF_CMD, ip_sioctl_subnet, ip_sioctl_subnet_restart },
        /* 138 */ { SIOCGLIFSUBNET, sizeof (struct lifreq),
                        IPI_GET_CMD, LIF_CMD, ip_sioctl_get_subnet, NULL },
        /* 139 */ { SIOCSLIFLNKINFO, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
                        LIF_CMD, ip_sioctl_lnkinfo, NULL },

        /* 140 */ { SIOCGLIFLNKINFO, sizeof (struct lifreq),
                        IPI_GET_CMD, LIF_CMD, ip_sioctl_get_lnkinfo, NULL },
        /* 141 */ { SIOCLIFDELND, sizeof (struct lifreq), IPI_PRIV,
                        LIF_CMD, ip_siocdelndp_v6, NULL },
        /* 142 */ { SIOCLIFGETND, sizeof (struct lifreq), IPI_GET_CMD,
                        LIF_CMD, ip_siocqueryndp_v6, NULL },
        /* 143 */ { SIOCLIFSETND, sizeof (struct lifreq), IPI_PRIV,
                        LIF_CMD, ip_siocsetndp_v6, NULL },
        /* 144 */ { SIOCTMYADDR, sizeof (struct sioc_addrreq), IPI_GET_CMD,
                        MISC_CMD, ip_sioctl_tmyaddr, NULL },
        /* 145 */ { SIOCTONLINK, sizeof (struct sioc_addrreq), IPI_GET_CMD,
                        MISC_CMD, ip_sioctl_tonlink, NULL },
        /* 146 */ { SIOCTMYSITE, sizeof (struct sioc_addrreq), 0,
                        MISC_CMD, ip_sioctl_tmysite, NULL },
        /* 147 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 148 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

        /* Old *IPSECONFIG ioctls are now deprecated, now see spdsock.c */
        /* 149 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 150 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 151 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 152 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

        /* 153 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

        /* 154 */ { SIOCGLIFBINDING, sizeof (struct lifreq), IPI_GET_CMD,
                        LIF_CMD, ip_sioctl_get_binding, NULL },
        /* 155 */ { SIOCSLIFGROUPNAME, sizeof (struct lifreq),
                        IPI_PRIV | IPI_WR,
                        LIF_CMD, ip_sioctl_groupname, ip_sioctl_groupname },
        /* 156 */ { SIOCGLIFGROUPNAME, sizeof (struct lifreq),
                        IPI_GET_CMD, LIF_CMD, ip_sioctl_get_groupname, NULL },
        /* 157 */ { SIOCGLIFGROUPINFO, sizeof (lifgroupinfo_t),
                        IPI_GET_CMD, MISC_CMD, ip_sioctl_groupinfo, NULL },

        /* Leave 158-160 unused; used to be SIOC*IFARP ioctls */
        /* 158 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 159 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 160 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

        /* 161 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },

        /* These are handled in ip_sioctl_copyin_setup itself */
        /* 162 */ { SIOCGIP6ADDRPOLICY, 0, IPI_NULL_BCONT,
                        MISC_CMD, NULL, NULL },
        /* 163 */ { SIOCSIP6ADDRPOLICY, 0, IPI_PRIV | IPI_NULL_BCONT,
                        MISC_CMD, NULL, NULL },
        /* 164 */ { SIOCGDSTINFO, 0, IPI_GET_CMD, MISC_CMD, NULL, NULL },

        /* 165 */ { SIOCGLIFCONF, 0, IPI_GET_CMD, MISC_CMD,
                        ip_sioctl_get_lifconf, NULL },

        /* 166 */ { SIOCSXARP, sizeof (struct xarpreq), IPI_PRIV | IPI_WR,
                        XARP_CMD, ip_sioctl_arp, NULL },
        /* 167 */ { SIOCGXARP, sizeof (struct xarpreq), IPI_GET_CMD,
                        XARP_CMD, ip_sioctl_arp, NULL },
        /* 168 */ { SIOCDXARP, sizeof (struct xarpreq), IPI_PRIV | IPI_WR,
                        XARP_CMD, ip_sioctl_arp, NULL },

        /* SIOCPOPSOCKFS is not handled by IP */
        /* 169 */ { IPI_DONTCARE /* SIOCPOPSOCKFS */, 0, 0, 0, NULL, NULL },

        /* 170 */ { SIOCGLIFZONE, sizeof (struct lifreq),
                        IPI_GET_CMD, LIF_CMD, ip_sioctl_get_lifzone, NULL },
        /* 171 */ { SIOCSLIFZONE, sizeof (struct lifreq),
                        IPI_PRIV | IPI_WR, LIF_CMD, ip_sioctl_slifzone,
                        ip_sioctl_slifzone_restart },
        /* 172-174 are SCTP ioctls and not handled by IP */
        /* 172 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 173 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 174 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* 175 */ { SIOCGLIFUSESRC, sizeof (struct lifreq),
                        IPI_GET_CMD, LIF_CMD,
                        ip_sioctl_get_lifusesrc, 0 },
        /* 176 */ { SIOCSLIFUSESRC, sizeof (struct lifreq),
                        IPI_PRIV | IPI_WR,
                        LIF_CMD, ip_sioctl_slifusesrc,
                        NULL },
        /* 177 */ { SIOCGLIFSRCOF, 0, IPI_GET_CMD, MISC_CMD,
                        ip_sioctl_get_lifsrcof, NULL },
        /* 178 */ { SIOCGMSFILTER, sizeof (struct group_filter), IPI_GET_CMD,
                        MSFILT_CMD, ip_sioctl_msfilter, NULL },
        /* 179 */ { SIOCSMSFILTER, sizeof (struct group_filter), 0,
                        MSFILT_CMD, ip_sioctl_msfilter, NULL },
        /* 180 */ { SIOCGIPMSFILTER, sizeof (struct ip_msfilter), IPI_GET_CMD,
                        MSFILT_CMD, ip_sioctl_msfilter, NULL },
        /* 181 */ { SIOCSIPMSFILTER, sizeof (struct ip_msfilter), 0,
                        MSFILT_CMD, ip_sioctl_msfilter, NULL },
        /* 182 */ { IPI_DONTCARE, 0, 0, 0, NULL, NULL },
        /* SIOCSENABLESDP is handled by SDP */
        /* 183 */ { IPI_DONTCARE /* SIOCSENABLESDP */, 0, 0, 0, NULL, NULL },
        /* 184 */ { IPI_DONTCARE /* SIOCSQPTR */, 0, 0, 0, NULL, NULL },
        /* 185 */ { SIOCGIFHWADDR, sizeof (struct ifreq), IPI_GET_CMD,
                        IF_CMD, ip_sioctl_get_ifhwaddr, NULL },
        /* 186 */ { IPI_DONTCARE /* SIOCGSTAMP */, 0, 0, 0, NULL, NULL },
        /* 187 */ { SIOCILB, 0, IPI_PRIV | IPI_GET_CMD, MISC_CMD,
                        ip_sioctl_ilb_cmd, NULL },
        /* 188 */ { SIOCGETPROP, sizeof (mod_ioc_prop_t), IPI_GET_CMD,
                MISC_CMD, ip_sioctl_getsetprop, NULL },
        /* 189 */ { SIOCSETPROP, sizeof (mod_ioc_prop_t), IPI_PRIV,
                MISC_CMD, ip_sioctl_getsetprop, NULL},
        /* 190 */ { SIOCGLIFDADSTATE, sizeof (struct lifreq),
                        IPI_GET_CMD, LIF_CMD, ip_sioctl_get_dadstate, NULL },
        /* 191 */ { SIOCSLIFPREFIX, sizeof (struct lifreq), IPI_PRIV | IPI_WR,
                        LIF_CMD, ip_sioctl_prefix, ip_sioctl_prefix_restart },
        /* 192 */ { SIOCGLIFHWADDR, sizeof (struct lifreq), IPI_GET_CMD,
                        LIF_CMD, ip_sioctl_get_lifhwaddr, NULL }
};

int ip_ndx_ioctl_count = sizeof (ip_ndx_ioctl_table) / sizeof (ip_ioctl_cmd_t);

ip_ioctl_cmd_t ip_misc_ioctl_table[] = {
        { I_LINK,       0, IPI_PRIV | IPI_WR, 0, NULL, NULL },
        { I_UNLINK,     0, IPI_PRIV | IPI_WR, 0, NULL, NULL },
        { I_PLINK,      0, IPI_PRIV | IPI_WR, 0, NULL, NULL },
        { I_PUNLINK,    0, IPI_PRIV | IPI_WR, 0, NULL, NULL },
        { ND_GET,       0, 0, 0, NULL, NULL },
        { ND_SET,       0, IPI_PRIV | IPI_WR, 0, NULL, NULL },
        { IP_IOCTL,     0, 0, 0, NULL, NULL },
        { SIOCGETVIFCNT, sizeof (struct sioc_vif_req), IPI_GET_CMD,
                MISC_CMD, mrt_ioctl},
        { SIOCGETSGCNT, sizeof (struct sioc_sg_req), IPI_GET_CMD,
                MISC_CMD, mrt_ioctl},
        { SIOCGETLSGCNT, sizeof (struct sioc_lsg_req), IPI_GET_CMD,
                MISC_CMD, mrt_ioctl}
};

int ip_misc_ioctl_count =
    sizeof (ip_misc_ioctl_table) / sizeof (ip_ioctl_cmd_t);

int     conn_drain_nthreads;            /* Number of drainers reqd. */
                                        /* Settable in /etc/system */
/* Defined in ip_ire.c */
extern uint32_t ip_ire_max_bucket_cnt, ip6_ire_max_bucket_cnt;
extern uint32_t ip_ire_min_bucket_cnt, ip6_ire_min_bucket_cnt;
extern uint32_t ip_ire_mem_ratio, ip_ire_cpu_ratio;

static nv_t     ire_nv_arr[] = {
        { IRE_BROADCAST, "BROADCAST" },
        { IRE_LOCAL, "LOCAL" },
        { IRE_LOOPBACK, "LOOPBACK" },
        { IRE_DEFAULT, "DEFAULT" },
        { IRE_PREFIX, "PREFIX" },
        { IRE_IF_NORESOLVER, "IF_NORESOL" },
        { IRE_IF_RESOLVER, "IF_RESOLV" },
        { IRE_IF_CLONE, "IF_CLONE" },
        { IRE_HOST, "HOST" },
        { IRE_MULTICAST, "MULTICAST" },
        { IRE_NOROUTE, "NOROUTE" },
        { 0 }
};

nv_t    *ire_nv_tbl = ire_nv_arr;

/* Simple ICMP IP Header Template */
static ipha_t icmp_ipha = {
        IP_SIMPLE_HDR_VERSION, 0, 0, 0, 0, 0, IPPROTO_ICMP
};

struct module_info ip_mod_info = {
        IP_MOD_ID, IP_MOD_NAME, IP_MOD_MINPSZ, IP_MOD_MAXPSZ, IP_MOD_HIWAT,
        IP_MOD_LOWAT
};

/*
 * Duplicate static symbols within a module confuses mdb; so we avoid the
 * problem by making the symbols here distinct from those in udp.c.
 */

/*
 * Entry points for IP as a device and as a module.
 * We have separate open functions for the /dev/ip and /dev/ip6 devices.
 */
static struct qinit iprinitv4 = {
        ip_rput, NULL, ip_openv4, ip_close, NULL, &ip_mod_info
};

struct qinit iprinitv6 = {
        ip_rput_v6, NULL, ip_openv6, ip_close, NULL, &ip_mod_info
};

static struct qinit ipwinit = {
        ip_wput_nondata, ip_wsrv, NULL, NULL, NULL, &ip_mod_info
};

static struct qinit iplrinit = {
        ip_lrput, NULL, ip_openv4, ip_close, NULL, &ip_mod_info
};

static struct qinit iplwinit = {
        ip_lwput, NULL, NULL, NULL, NULL, &ip_mod_info
};

/* For AF_INET aka /dev/ip */
struct streamtab ipinfov4 = {
        &iprinitv4, &ipwinit, &iplrinit, &iplwinit
};

/* For AF_INET6 aka /dev/ip6 */
struct streamtab ipinfov6 = {
        &iprinitv6, &ipwinit, &iplrinit, &iplwinit
};

#ifdef  DEBUG
boolean_t skip_sctp_cksum = B_FALSE;
#endif

/*
 * Generate an ICMP fragmentation needed message.
 * When called from ip_output side a minimal ip_recv_attr_t needs to be
 * constructed by the caller.
 */
void
icmp_frag_needed(mblk_t *mp, int mtu, ip_recv_attr_t *ira)
{
        icmph_t icmph;
        ip_stack_t      *ipst = ira->ira_ill->ill_ipst;

        mp = icmp_pkt_err_ok(mp, ira);
        if (mp == NULL)
                return;

        bzero(&icmph, sizeof (icmph_t));
        icmph.icmph_type = ICMP_DEST_UNREACHABLE;
        icmph.icmph_code = ICMP_FRAGMENTATION_NEEDED;
        icmph.icmph_du_mtu = htons((uint16_t)mtu);
        BUMP_MIB(&ipst->ips_icmp_mib, icmpOutFragNeeded);
        BUMP_MIB(&ipst->ips_icmp_mib, icmpOutDestUnreachs);

        icmp_pkt(mp, &icmph, sizeof (icmph_t), ira);
}

/*
 * icmp_inbound_v4 deals with ICMP messages that are handled by IP.
 * If the ICMP message is consumed by IP, i.e., it should not be delivered
 * to any IPPROTO_ICMP raw sockets, then it returns NULL.
 * Likewise, if the ICMP error is misformed (too short, etc), then it
 * returns NULL. The caller uses this to determine whether or not to send
 * to raw sockets.
 *
 * All error messages are passed to the matching transport stream.
 *
 * The following cases are handled by icmp_inbound:
 * 1) It needs to send a reply back and possibly delivering it
 *    to the "interested" upper clients.
 * 2) Return the mblk so that the caller can pass it to the RAW socket clients.
 * 3) It needs to change some values in IP only.
 * 4) It needs to change some values in IP and upper layers e.g TCP
 *    by delivering an error to the upper layers.
 *
 * We handle the above three cases in the context of IPsec in the
 * following way :
 *
 * 1) Send the reply back in the same way as the request came in.
 *    If it came in encrypted, it goes out encrypted. If it came in
 *    clear, it goes out in clear. Thus, this will prevent chosen
 *    plain text attack.
 * 2) The client may or may not expect things to come in secure.
 *    If it comes in secure, the policy constraints are checked
 *    before delivering it to the upper layers. If it comes in
 *    clear, ipsec_inbound_accept_clear will decide whether to
 *    accept this in clear or not. In both the cases, if the returned
 *    message (IP header + 8 bytes) that caused the icmp message has
 *    AH/ESP headers, it is sent up to AH/ESP for validation before
 *    sending up. If there are only 8 bytes of returned message, then
 *    upper client will not be notified.
 * 3) Check with global policy to see whether it matches the constaints.
 *    But this will be done only if icmp_accept_messages_in_clear is
 *    zero.
 * 4) If we need to change both in IP and ULP, then the decision taken
 *    while affecting the values in IP and while delivering up to TCP
 *    should be the same.
 *
 *      There are two cases.
 *
 *      a) If we reject data at the IP layer (ipsec_check_global_policy()
 *         failed), we will not deliver it to the ULP, even though they
 *         are *willing* to accept in *clear*. This is fine as our global
 *         disposition to icmp messages asks us reject the datagram.
 *
 *      b) If we accept data at the IP layer (ipsec_check_global_policy()
 *         succeeded or icmp_accept_messages_in_clear is 1), and not able
 *         to deliver it to ULP (policy failed), it can lead to
 *         consistency problems. The cases known at this time are
 *         ICMP_DESTINATION_UNREACHABLE  messages with following code
 *         values :
 *
 *         - ICMP_FRAGMENTATION_NEEDED : IP adapts to the new value
 *           and Upper layer rejects. Then the communication will
 *           come to a stop. This is solved by making similar decisions
 *           at both levels. Currently, when we are unable to deliver
 *           to the Upper Layer (due to policy failures) while IP has
 *           adjusted dce_pmtu, the next outbound datagram would
 *           generate a local ICMP_FRAGMENTATION_NEEDED message - which
 *           will be with the right level of protection. Thus the right
 *           value will be communicated even if we are not able to
 *           communicate when we get from the wire initially. But this
 *           assumes there would be at least one outbound datagram after
 *           IP has adjusted its dce_pmtu value. To make things
 *           simpler, we accept in clear after the validation of
 *           AH/ESP headers.
 *
 *         - Other ICMP ERRORS : We may not be able to deliver it to the
 *           upper layer depending on the level of protection the upper
 *           layer expects and the disposition in ipsec_inbound_accept_clear().
 *           ipsec_inbound_accept_clear() decides whether a given ICMP error
 *           should be accepted in clear when the Upper layer expects secure.
 *           Thus the communication may get aborted by some bad ICMP
 *           packets.
 */
mblk_t *
icmp_inbound_v4(mblk_t *mp, ip_recv_attr_t *ira)
{
        icmph_t         *icmph;
        ipha_t          *ipha;          /* Outer header */
        int             ip_hdr_length;  /* Outer header length */
        boolean_t       interested;
        ipif_t          *ipif;
        uint32_t        ts;
        uint32_t        *tsp;
        timestruc_t     now;
        ill_t           *ill = ira->ira_ill;
        ip_stack_t      *ipst = ill->ill_ipst;
        zoneid_t        zoneid = ira->ira_zoneid;
        int             len_needed;
        mblk_t          *mp_ret = NULL;

        ipha = (ipha_t *)mp->b_rptr;

        BUMP_MIB(&ipst->ips_icmp_mib, icmpInMsgs);

        ip_hdr_length = ira->ira_ip_hdr_length;
        if ((mp->b_wptr - mp->b_rptr) < (ip_hdr_length + ICMPH_SIZE)) {
                if (ira->ira_pktlen < (ip_hdr_length + ICMPH_SIZE)) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInTruncatedPkts);
                        ip_drop_input("ipIfStatsInTruncatedPkts", mp, ill);
                        freemsg(mp);
                        return (NULL);
                }
                /* Last chance to get real. */
                ipha = ip_pullup(mp, ip_hdr_length + ICMPH_SIZE, ira);
                if (ipha == NULL) {
                        BUMP_MIB(&ipst->ips_icmp_mib, icmpInErrors);
                        freemsg(mp);
                        return (NULL);
                }
        }

        /* The IP header will always be a multiple of four bytes */
        icmph = (icmph_t *)&mp->b_rptr[ip_hdr_length];
        ip2dbg(("icmp_inbound_v4: type %d code %d\n", icmph->icmph_type,
            icmph->icmph_code));

        /*
         * We will set "interested" to "true" if we should pass a copy to
         * the transport or if we handle the packet locally.
         */
        interested = B_FALSE;
        switch (icmph->icmph_type) {
        case ICMP_ECHO_REPLY:
                BUMP_MIB(&ipst->ips_icmp_mib, icmpInEchoReps);
                break;
        case ICMP_DEST_UNREACHABLE:
                if (icmph->icmph_code == ICMP_FRAGMENTATION_NEEDED)
                        BUMP_MIB(&ipst->ips_icmp_mib, icmpInFragNeeded);
                interested = B_TRUE;    /* Pass up to transport */
                BUMP_MIB(&ipst->ips_icmp_mib, icmpInDestUnreachs);
                break;
        case ICMP_SOURCE_QUENCH:
                interested = B_TRUE;    /* Pass up to transport */
                BUMP_MIB(&ipst->ips_icmp_mib, icmpInSrcQuenchs);
                break;
        case ICMP_REDIRECT:
                if (!ipst->ips_ip_ignore_redirect)
                        interested = B_TRUE;
                BUMP_MIB(&ipst->ips_icmp_mib, icmpInRedirects);
                break;
        case ICMP_ECHO_REQUEST:
                /*
                 * Whether to respond to echo requests that come in as IP
                 * broadcasts or as IP multicast is subject to debate
                 * (what isn't?).  We aim to please, you pick it.
                 * Default is do it.
                 */
                if (ira->ira_flags & IRAF_MULTICAST) {
                        /* multicast: respond based on tunable */
                        interested = ipst->ips_ip_g_resp_to_echo_mcast;
                } else if (ira->ira_flags & IRAF_BROADCAST) {
                        /* broadcast: respond based on tunable */
                        interested = ipst->ips_ip_g_resp_to_echo_bcast;
                } else {
                        /* unicast: always respond */
                        interested = B_TRUE;
                }
                BUMP_MIB(&ipst->ips_icmp_mib, icmpInEchos);
                if (!interested) {
                        /* We never pass these to RAW sockets */
                        freemsg(mp);
                        return (NULL);
                }

                /* Check db_ref to make sure we can modify the packet. */
                if (mp->b_datap->db_ref > 1) {
                        mblk_t  *mp1;

                        mp1 = copymsg(mp);
                        freemsg(mp);
                        if (!mp1) {
                                BUMP_MIB(&ipst->ips_icmp_mib, icmpOutDrops);
                                return (NULL);
                        }
                        mp = mp1;
                        ipha = (ipha_t *)mp->b_rptr;
                        icmph = (icmph_t *)&mp->b_rptr[ip_hdr_length];
                }
                icmph->icmph_type = ICMP_ECHO_REPLY;
                BUMP_MIB(&ipst->ips_icmp_mib, icmpOutEchoReps);
                icmp_send_reply_v4(mp, ipha, icmph, ira);
                return (NULL);

        case ICMP_ROUTER_ADVERTISEMENT:
        case ICMP_ROUTER_SOLICITATION:
                break;
        case ICMP_TIME_EXCEEDED:
                interested = B_TRUE;    /* Pass up to transport */
                BUMP_MIB(&ipst->ips_icmp_mib, icmpInTimeExcds);
                break;
        case ICMP_PARAM_PROBLEM:
                interested = B_TRUE;    /* Pass up to transport */
                BUMP_MIB(&ipst->ips_icmp_mib, icmpInParmProbs);
                break;
        case ICMP_TIME_STAMP_REQUEST:
                /* Response to Time Stamp Requests is local policy. */
                if (ipst->ips_ip_g_resp_to_timestamp) {
                        if (ira->ira_flags & IRAF_MULTIBROADCAST)
                                interested =
                                    ipst->ips_ip_g_resp_to_timestamp_bcast;
                        else
                                interested = B_TRUE;
                }
                if (!interested) {
                        /* We never pass these to RAW sockets */
                        freemsg(mp);
                        return (NULL);
                }

                /* Make sure we have enough of the packet */
                len_needed = ip_hdr_length + ICMPH_SIZE +
                    3 * sizeof (uint32_t);

                if (mp->b_wptr - mp->b_rptr < len_needed) {
                        ipha = ip_pullup(mp, len_needed, ira);
                        if (ipha == NULL) {
                                BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                                ip_drop_input("ipIfStatsInDiscards - ip_pullup",
                                    mp, ill);
                                freemsg(mp);
                                return (NULL);
                        }
                        /* Refresh following the pullup. */
                        icmph = (icmph_t *)&mp->b_rptr[ip_hdr_length];
                }
                BUMP_MIB(&ipst->ips_icmp_mib, icmpInTimestamps);
                /* Check db_ref to make sure we can modify the packet. */
                if (mp->b_datap->db_ref > 1) {
                        mblk_t  *mp1;

                        mp1 = copymsg(mp);
                        freemsg(mp);
                        if (!mp1) {
                                BUMP_MIB(&ipst->ips_icmp_mib, icmpOutDrops);
                                return (NULL);
                        }
                        mp = mp1;
                        ipha = (ipha_t *)mp->b_rptr;
                        icmph = (icmph_t *)&mp->b_rptr[ip_hdr_length];
                }
                icmph->icmph_type = ICMP_TIME_STAMP_REPLY;
                tsp = (uint32_t *)&icmph[1];
                tsp++;          /* Skip past 'originate time' */
                /* Compute # of milliseconds since midnight */
                gethrestime(&now);
                ts = (now.tv_sec % (24 * 60 * 60)) * 1000 +
                    NSEC2MSEC(now.tv_nsec);
                *tsp++ = htonl(ts);     /* Lay in 'receive time' */
                *tsp++ = htonl(ts);     /* Lay in 'send time' */
                BUMP_MIB(&ipst->ips_icmp_mib, icmpOutTimestampReps);
                icmp_send_reply_v4(mp, ipha, icmph, ira);
                return (NULL);

        case ICMP_TIME_STAMP_REPLY:
                BUMP_MIB(&ipst->ips_icmp_mib, icmpInTimestampReps);
                break;
        case ICMP_INFO_REQUEST:
                /* Per RFC 1122 3.2.2.7, ignore this. */
        case ICMP_INFO_REPLY:
                break;
        case ICMP_ADDRESS_MASK_REQUEST:
                if (ira->ira_flags & IRAF_MULTIBROADCAST) {
                        interested =
                            ipst->ips_ip_respond_to_address_mask_broadcast;
                } else {
                        interested = B_TRUE;
                }
                if (!interested) {
                        /* We never pass these to RAW sockets */
                        freemsg(mp);
                        return (NULL);
                }
                len_needed = ip_hdr_length + ICMPH_SIZE + IP_ADDR_LEN;
                if (mp->b_wptr - mp->b_rptr < len_needed) {
                        ipha = ip_pullup(mp, len_needed, ira);
                        if (ipha == NULL) {
                                BUMP_MIB(ill->ill_ip_mib,
                                    ipIfStatsInTruncatedPkts);
                                ip_drop_input("ipIfStatsInTruncatedPkts", mp,
                                    ill);
                                freemsg(mp);
                                return (NULL);
                        }
                        /* Refresh following the pullup. */
                        icmph = (icmph_t *)&mp->b_rptr[ip_hdr_length];
                }
                BUMP_MIB(&ipst->ips_icmp_mib, icmpInAddrMasks);
                /* Check db_ref to make sure we can modify the packet. */
                if (mp->b_datap->db_ref > 1) {
                        mblk_t  *mp1;

                        mp1 = copymsg(mp);
                        freemsg(mp);
                        if (!mp1) {
                                BUMP_MIB(&ipst->ips_icmp_mib, icmpOutDrops);
                                return (NULL);
                        }
                        mp = mp1;
                        ipha = (ipha_t *)mp->b_rptr;
                        icmph = (icmph_t *)&mp->b_rptr[ip_hdr_length];
                }
                /*
                 * Need the ipif with the mask be the same as the source
                 * address of the mask reply. For unicast we have a specific
                 * ipif. For multicast/broadcast we only handle onlink
                 * senders, and use the source address to pick an ipif.
                 */
                ipif = ipif_lookup_addr(ipha->ipha_dst, ill, zoneid, ipst);
                if (ipif == NULL) {
                        /* Broadcast or multicast */
                        ipif = ipif_lookup_remote(ill, ipha->ipha_src, zoneid);
                        if (ipif == NULL) {
                                freemsg(mp);
                                return (NULL);
                        }
                }
                icmph->icmph_type = ICMP_ADDRESS_MASK_REPLY;
                bcopy(&ipif->ipif_net_mask, &icmph[1], IP_ADDR_LEN);
                ipif_refrele(ipif);
                BUMP_MIB(&ipst->ips_icmp_mib, icmpOutAddrMaskReps);
                icmp_send_reply_v4(mp, ipha, icmph, ira);
                return (NULL);

        case ICMP_ADDRESS_MASK_REPLY:
                BUMP_MIB(&ipst->ips_icmp_mib, icmpInAddrMaskReps);
                break;
        default:
                interested = B_TRUE;    /* Pass up to transport */
                BUMP_MIB(&ipst->ips_icmp_mib, icmpInUnknowns);
                break;
        }
        /*
         * See if there is an ICMP client to avoid an extra copymsg/freemsg
         * if there isn't one.
         */
        if (ipst->ips_ipcl_proto_fanout_v4[IPPROTO_ICMP].connf_head != NULL) {
                /* If there is an ICMP client and we want one too, copy it. */

                if (!interested) {
                        /* Caller will deliver to RAW sockets */
                        return (mp);
                }
                mp_ret = copymsg(mp);
                if (mp_ret == NULL) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                        ip_drop_input("ipIfStatsInDiscards - copymsg", mp, ill);
                }
        } else if (!interested) {
                /* Neither we nor raw sockets are interested. Drop packet now */
                freemsg(mp);
                return (NULL);
        }

        /*
         * ICMP error or redirect packet. Make sure we have enough of
         * the header and that db_ref == 1 since we might end up modifying
         * the packet.
         */
        if (mp->b_cont != NULL) {
                if (ip_pullup(mp, -1, ira) == NULL) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                        ip_drop_input("ipIfStatsInDiscards - ip_pullup",
                            mp, ill);
                        freemsg(mp);
                        return (mp_ret);
                }
        }

        if (mp->b_datap->db_ref > 1) {
                mblk_t  *mp1;

                mp1 = copymsg(mp);
                if (mp1 == NULL) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                        ip_drop_input("ipIfStatsInDiscards - copymsg", mp, ill);
                        freemsg(mp);
                        return (mp_ret);
                }
                freemsg(mp);
                mp = mp1;
        }

        /*
         * In case mp has changed, verify the message before any further
         * processes.
         */
        ipha = (ipha_t *)mp->b_rptr;
        icmph = (icmph_t *)&mp->b_rptr[ip_hdr_length];
        if (!icmp_inbound_verify_v4(mp, icmph, ira)) {
                freemsg(mp);
                return (mp_ret);
        }

        switch (icmph->icmph_type) {
        case ICMP_REDIRECT:
                icmp_redirect_v4(mp, ipha, icmph, ira);
                break;
        case ICMP_DEST_UNREACHABLE:
                if (icmph->icmph_code == ICMP_FRAGMENTATION_NEEDED) {
                        /* Update DCE and adjust MTU is icmp header if needed */
                        icmp_inbound_too_big_v4(icmph, ira);
                }
                /* FALLTHROUGH */
        default:
                icmp_inbound_error_fanout_v4(mp, icmph, ira);
                break;
        }
        return (mp_ret);
}

/*
 * Send an ICMP echo, timestamp or address mask reply.
 * The caller has already updated the payload part of the packet.
 * We handle the ICMP checksum, IP source address selection and feed
 * the packet into ip_output_simple.
 */
static void
icmp_send_reply_v4(mblk_t *mp, ipha_t *ipha, icmph_t *icmph,
    ip_recv_attr_t *ira)
{
        uint_t          ip_hdr_length = ira->ira_ip_hdr_length;
        ill_t           *ill = ira->ira_ill;
        ip_stack_t      *ipst = ill->ill_ipst;
        ip_xmit_attr_t  ixas;

        /* Send out an ICMP packet */
        icmph->icmph_checksum = 0;
        icmph->icmph_checksum = IP_CSUM(mp, ip_hdr_length, 0);
        /* Reset time to live. */
        ipha->ipha_ttl = ipst->ips_ip_def_ttl;
        {
                /* Swap source and destination addresses */
                ipaddr_t tmp;

                tmp = ipha->ipha_src;
                ipha->ipha_src = ipha->ipha_dst;
                ipha->ipha_dst = tmp;
        }
        ipha->ipha_ident = 0;
        if (!IS_SIMPLE_IPH(ipha))
                icmp_options_update(ipha);

        bzero(&ixas, sizeof (ixas));
        ixas.ixa_flags = IXAF_BASIC_SIMPLE_V4;
        ixas.ixa_zoneid = ira->ira_zoneid;
        ixas.ixa_cred = kcred;
        ixas.ixa_cpid = NOPID;
        ixas.ixa_ifindex = 0;
        ixas.ixa_ipst = ipst;
        ixas.ixa_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;

        if (!(ira->ira_flags & IRAF_IPSEC_SECURE)) {
                /*
                 * This packet should go out the same way as it
                 * came in i.e in clear, independent of the IPsec policy
                 * for transmitting packets.
                 */
                ixas.ixa_flags |= IXAF_NO_IPSEC;
        } else {
                if (!ipsec_in_to_out(ira, &ixas, mp, ipha, NULL)) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                        /* Note: mp already consumed and ip_drop_packet done */
                        return;
                }
        }
        if (ira->ira_flags & IRAF_MULTIBROADCAST) {
                /*
                 * Not one or our addresses (IRE_LOCALs), thus we let
                 * ip_output_simple pick the source.
                 */
                ipha->ipha_src = INADDR_ANY;
                ixas.ixa_flags |= IXAF_SET_SOURCE;
        }
        /* Should we send with DF and use dce_pmtu? */
        if (ipst->ips_ipv4_icmp_return_pmtu) {
                ixas.ixa_flags |= IXAF_PMTU_DISCOVERY;
                ipha->ipha_fragment_offset_and_flags |= IPH_DF_HTONS;
        }

        BUMP_MIB(&ipst->ips_icmp_mib, icmpOutMsgs);

        (void) ip_output_simple(mp, &ixas);
        ixa_cleanup(&ixas);
}

/*
 * Verify the ICMP messages for either for ICMP error or redirect packet.
 * The caller should have fully pulled up the message. If it's a redirect
 * packet, only basic checks on IP header will be done; otherwise, verify
 * the packet by looking at the included ULP header.
 *
 * Called before icmp_inbound_error_fanout_v4 is called.
 */
static boolean_t
icmp_inbound_verify_v4(mblk_t *mp, icmph_t *icmph, ip_recv_attr_t *ira)
{
        ill_t           *ill = ira->ira_ill;
        int             hdr_length;
        ip_stack_t      *ipst = ira->ira_ill->ill_ipst;
        conn_t          *connp;
        ipha_t          *ipha;  /* Inner IP header */

        ipha = (ipha_t *)&icmph[1];
        if ((uchar_t *)ipha + IP_SIMPLE_HDR_LENGTH > mp->b_wptr)
                goto truncated;

        hdr_length = IPH_HDR_LENGTH(ipha);

        if ((IPH_HDR_VERSION(ipha) != IPV4_VERSION))
                goto discard_pkt;

        if (hdr_length < sizeof (ipha_t))
                goto truncated;

        if ((uchar_t *)ipha + hdr_length > mp->b_wptr)
                goto truncated;

        /*
         * Stop here for ICMP_REDIRECT.
         */
        if (icmph->icmph_type == ICMP_REDIRECT)
                return (B_TRUE);

        /*
         * ICMP errors only.
         */
        switch (ipha->ipha_protocol) {
        case IPPROTO_UDP:
                /*
                 * Verify we have at least ICMP_MIN_TP_HDR_LEN bytes of
                 * transport header.
                 */
                if ((uchar_t *)ipha + hdr_length + ICMP_MIN_TP_HDR_LEN >
                    mp->b_wptr)
                        goto truncated;
                break;
        case IPPROTO_TCP: {
                tcpha_t         *tcpha;

                /*
                 * Verify we have at least ICMP_MIN_TP_HDR_LEN bytes of
                 * transport header.
                 */
                if ((uchar_t *)ipha + hdr_length + ICMP_MIN_TP_HDR_LEN >
                    mp->b_wptr)
                        goto truncated;

                tcpha = (tcpha_t *)((uchar_t *)ipha + hdr_length);
                connp = ipcl_tcp_lookup_reversed_ipv4(ipha, tcpha, TCPS_LISTEN,
                    ipst);
                if (connp == NULL)
                        goto discard_pkt;

                if ((connp->conn_verifyicmp != NULL) &&
                    !connp->conn_verifyicmp(connp, tcpha, icmph, NULL, ira)) {
                        CONN_DEC_REF(connp);
                        goto discard_pkt;
                }
                CONN_DEC_REF(connp);
                break;
        }
        case IPPROTO_SCTP:
                /*
                 * Verify we have at least ICMP_MIN_TP_HDR_LEN bytes of
                 * transport header.
                 */
                if ((uchar_t *)ipha + hdr_length + ICMP_MIN_TP_HDR_LEN >
                    mp->b_wptr)
                        goto truncated;
                break;
        case IPPROTO_ESP:
        case IPPROTO_AH:
                break;
        case IPPROTO_ENCAP:
                if ((uchar_t *)ipha + hdr_length + sizeof (ipha_t) >
                    mp->b_wptr)
                        goto truncated;
                break;
        default:
                break;
        }

        return (B_TRUE);

discard_pkt:
        /* Bogus ICMP error. */
        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
        return (B_FALSE);

truncated:
        /* We pulled up everthing already. Must be truncated */
        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInTruncatedPkts);
        ip_drop_input("ipIfStatsInTruncatedPkts", mp, ill);
        return (B_FALSE);
}

/* Table from RFC 1191 */
static int icmp_frag_size_table[] =
{ 32000, 17914, 8166, 4352, 2002, 1496, 1006, 508, 296, 68 };

/*
 * Process received ICMP Packet too big.
 * Just handles the DCE create/update, including using the above table of
 * PMTU guesses. The caller is responsible for validating the packet before
 * passing it in and also to fanout the ICMP error to any matching transport
 * conns. Assumes the message has been fully pulled up and verified.
 *
 * Before getting here, the caller has called icmp_inbound_verify_v4()
 * that should have verified with ULP to prevent undoing the changes we're
 * going to make to DCE. For example, TCP might have verified that the packet
 * which generated error is in the send window.
 *
 * In some cases modified this MTU in the ICMP header packet; the caller
 * should pass to the matching ULP after this returns.
 */
static void
icmp_inbound_too_big_v4(icmph_t *icmph, ip_recv_attr_t *ira)
{
        dce_t           *dce;
        int             old_mtu;
        int             mtu, orig_mtu;
        ipaddr_t        dst;
        boolean_t       disable_pmtud;
        ill_t           *ill = ira->ira_ill;
        ip_stack_t      *ipst = ill->ill_ipst;
        uint_t          hdr_length;
        ipha_t          *ipha;

        /* Caller already pulled up everything. */
        ipha = (ipha_t *)&icmph[1];
        ASSERT(icmph->icmph_type == ICMP_DEST_UNREACHABLE &&
            icmph->icmph_code == ICMP_FRAGMENTATION_NEEDED);
        ASSERT(ill != NULL);

        hdr_length = IPH_HDR_LENGTH(ipha);

        /*
         * We handle path MTU for source routed packets since the DCE
         * is looked up using the final destination.
         */
        dst = ip_get_dst(ipha);

        dce = dce_lookup_and_add_v4(dst, ipst);
        if (dce == NULL) {
                /* Couldn't add a unique one - ENOMEM */
                ip1dbg(("icmp_inbound_too_big_v4: no dce for 0x%x\n",
                    ntohl(dst)));
                return;
        }

        /* Check for MTU discovery advice as described in RFC 1191 */
        mtu = ntohs(icmph->icmph_du_mtu);
        orig_mtu = mtu;
        disable_pmtud = B_FALSE;

        mutex_enter(&dce->dce_lock);
        if (dce->dce_flags & DCEF_PMTU)
                old_mtu = dce->dce_pmtu;
        else
                old_mtu = ill->ill_mtu;

        if (icmph->icmph_du_zero != 0 || mtu < ipst->ips_ip_pmtu_min) {
                uint32_t length;
                int     i;

                /*
                 * Use the table from RFC 1191 to figure out
                 * the next "plateau" based on the length in
                 * the original IP packet.
                 */
                length = ntohs(ipha->ipha_length);
                DTRACE_PROBE2(ip4__pmtu__guess, dce_t *, dce,
                    uint32_t, length);
                if (old_mtu <= length &&
                    old_mtu >= length - hdr_length) {
                        /*
                         * Handle broken BSD 4.2 systems that
                         * return the wrong ipha_length in ICMP
                         * errors.
                         */
                        ip1dbg(("Wrong mtu: sent %d, dce %d\n",
                            length, old_mtu));
                        length -= hdr_length;
                }
                for (i = 0; i < A_CNT(icmp_frag_size_table); i++) {
                        if (length > icmp_frag_size_table[i])
                                break;
                }
                if (i == A_CNT(icmp_frag_size_table)) {
                        /* Smaller than IP_MIN_MTU! */
                        ip1dbg(("Too big for packet size %d\n",
                            length));
                        disable_pmtud = B_TRUE;
                        mtu = ipst->ips_ip_pmtu_min;
                } else {
                        mtu = icmp_frag_size_table[i];
                        ip1dbg(("Calculated mtu %d, packet size %d, "
                            "before %d\n", mtu, length, old_mtu));
                        if (mtu < ipst->ips_ip_pmtu_min) {
                                mtu = ipst->ips_ip_pmtu_min;
                                disable_pmtud = B_TRUE;
                        }
                }
        }
        if (disable_pmtud)
                dce->dce_flags |= DCEF_TOO_SMALL_PMTU;
        else
                dce->dce_flags &= ~DCEF_TOO_SMALL_PMTU;

        dce->dce_pmtu = MIN(old_mtu, mtu);
        /* Prepare to send the new max frag size for the ULP. */
        icmph->icmph_du_zero = 0;
        icmph->icmph_du_mtu =  htons((uint16_t)dce->dce_pmtu);
        DTRACE_PROBE4(ip4__pmtu__change, icmph_t *, icmph, dce_t *,
            dce, int, orig_mtu, int, mtu);

        /* We now have a PMTU for sure */
        dce->dce_flags |= DCEF_PMTU;
        dce->dce_last_change_time = TICK_TO_SEC(ddi_get_lbolt64());
        mutex_exit(&dce->dce_lock);
        /*
         * After dropping the lock the new value is visible to everyone.
         * Then we bump the generation number so any cached values reinspect
         * the dce_t.
         */
        dce_increment_generation(dce);
        dce_refrele(dce);
}

/*
 * If the packet in error is Self-Encapsulated, icmp_inbound_error_fanout_v4
 * calls this function.
 */
static mblk_t *
icmp_inbound_self_encap_error_v4(mblk_t *mp, ipha_t *ipha, ipha_t *in_ipha)
{
        int length;

        ASSERT(mp->b_datap->db_type == M_DATA);

        /* icmp_inbound_v4 has already pulled up the whole error packet */
        ASSERT(mp->b_cont == NULL);

        /*
         * The length that we want to overlay is the inner header
         * and what follows it.
         */
        length = msgdsize(mp) - ((uchar_t *)in_ipha - mp->b_rptr);

        /*
         * Overlay the inner header and whatever follows it over the
         * outer header.
         */
        bcopy((uchar_t *)in_ipha, (uchar_t *)ipha, length);

        /* Adjust for what we removed */
        mp->b_wptr -= (uchar_t *)in_ipha - (uchar_t *)ipha;
        return (mp);
}

/*
 * Try to pass the ICMP message upstream in case the ULP cares.
 *
 * If the packet that caused the ICMP error is secure, we send
 * it to AH/ESP to make sure that the attached packet has a
 * valid association. ipha in the code below points to the
 * IP header of the packet that caused the error.
 *
 * For IPsec cases, we let the next-layer-up (which has access to
 * cached policy on the conn_t, or can query the SPD directly)
 * subtract out any IPsec overhead if they must.  We therefore make no
 * adjustments here for IPsec overhead.
 *
 * IFN could have been generated locally or by some router.
 *
 * LOCAL : ire_send_wire (before calling ipsec_out_process) can call
 * icmp_frag_needed/icmp_pkt2big_v6 to generated a local IFN.
 *          This happens because IP adjusted its value of MTU on an
 *          earlier IFN message and could not tell the upper layer,
 *          the new adjusted value of MTU e.g. Packet was encrypted
 *          or there was not enough information to fanout to upper
 *          layers. Thus on the next outbound datagram, ire_send_wire
 *          generates the IFN, where IPsec processing has *not* been
 *          done.
 *
 *          Note that we retain ixa_fragsize across IPsec thus once
 *          we have picking ixa_fragsize and entered ipsec_out_process we do
 *          no change the fragsize even if the path MTU changes before
 *          we reach ip_output_post_ipsec.
 *
 *          In the local case, IRAF_LOOPBACK will be set indicating
 *          that IFN was generated locally.
 *
 * ROUTER : IFN could be secure or non-secure.
 *
 *          * SECURE : We use the IPSEC_IN to fanout to AH/ESP if the
 *            packet in error has AH/ESP headers to validate the AH/ESP
 *            headers. AH/ESP will verify whether there is a valid SA or
 *            not and send it back. We will fanout again if we have more
 *            data in the packet.
 *
 *            If the packet in error does not have AH/ESP, we handle it
 *            like any other case.
 *
 *          * NON_SECURE : If the packet in error has AH/ESP headers, we send it
 *            up to AH/ESP for validation. AH/ESP will verify whether there is a
 *            valid SA or not and send it back. We will fanout again if
 *            we have more data in the packet.
 *
 *            If the packet in error does not have AH/ESP, we handle it
 *            like any other case.
 *
 * The caller must have called icmp_inbound_verify_v4.
 */
static void
icmp_inbound_error_fanout_v4(mblk_t *mp, icmph_t *icmph, ip_recv_attr_t *ira)
{
        uint16_t        *up;    /* Pointer to ports in ULP header */
        uint32_t        ports;  /* reversed ports for fanout */
        ipha_t          ripha;  /* With reversed addresses */
        ipha_t          *ipha;  /* Inner IP header */
        uint_t          hdr_length; /* Inner IP header length */
        tcpha_t         *tcpha;
        conn_t          *connp;
        ill_t           *ill = ira->ira_ill;
        ip_stack_t      *ipst = ill->ill_ipst;
        ipsec_stack_t   *ipss = ipst->ips_netstack->netstack_ipsec;
        ill_t           *rill = ira->ira_rill;

        /* Caller already pulled up everything. */
        ipha = (ipha_t *)&icmph[1];
        ASSERT((uchar_t *)&ipha[1] <= mp->b_wptr);
        ASSERT(mp->b_cont == NULL);

        hdr_length = IPH_HDR_LENGTH(ipha);
        ira->ira_protocol = ipha->ipha_protocol;

        /*
         * We need a separate IP header with the source and destination
         * addresses reversed to do fanout/classification because the ipha in
         * the ICMP error is in the form we sent it out.
         */
        ripha.ipha_src = ipha->ipha_dst;
        ripha.ipha_dst = ipha->ipha_src;
        ripha.ipha_protocol = ipha->ipha_protocol;
        ripha.ipha_version_and_hdr_length = ipha->ipha_version_and_hdr_length;

        ip2dbg(("icmp_inbound_error_v4: proto %d %x to %x: %d/%d\n",
            ripha.ipha_protocol, ntohl(ipha->ipha_src),
            ntohl(ipha->ipha_dst),
            icmph->icmph_type, icmph->icmph_code));

        switch (ipha->ipha_protocol) {
        case IPPROTO_UDP:
                up = (uint16_t *)((uchar_t *)ipha + hdr_length);

                /* Attempt to find a client stream based on port. */
                ip2dbg(("icmp_inbound_error_v4: UDP ports %d to %d\n",
                    ntohs(up[0]), ntohs(up[1])));

                /* Note that we send error to all matches. */
                ira->ira_flags |= IRAF_ICMP_ERROR;
                ip_fanout_udp_multi_v4(mp, &ripha, up[0], up[1], ira);
                ira->ira_flags &= ~IRAF_ICMP_ERROR;
                return;

        case IPPROTO_TCP:
                /*
                 * Find a TCP client stream for this packet.
                 * Note that we do a reverse lookup since the header is
                 * in the form we sent it out.
                 */
                tcpha = (tcpha_t *)((uchar_t *)ipha + hdr_length);
                connp = ipcl_tcp_lookup_reversed_ipv4(ipha, tcpha, TCPS_LISTEN,
                    ipst);
                if (connp == NULL)
                        goto discard_pkt;

                if (CONN_INBOUND_POLICY_PRESENT(connp, ipss) ||
                    (ira->ira_flags & IRAF_IPSEC_SECURE)) {
                        mp = ipsec_check_inbound_policy(mp, connp,
                            ipha, NULL, ira);
                        if (mp == NULL) {
                                BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                                /* Note that mp is NULL */
                                ip_drop_input("ipIfStatsInDiscards", mp, ill);
                                CONN_DEC_REF(connp);
                                return;
                        }
                }

                ira->ira_flags |= IRAF_ICMP_ERROR;
                ira->ira_ill = ira->ira_rill = NULL;
                if (IPCL_IS_TCP(connp)) {
                        SQUEUE_ENTER_ONE(connp->conn_sqp, mp,
                            connp->conn_recvicmp, connp, ira, SQ_FILL,
                            SQTAG_TCP_INPUT_ICMP_ERR);
                } else {
                        /* Not TCP; must be SOCK_RAW, IPPROTO_TCP */
                        (connp->conn_recv)(connp, mp, NULL, ira);
                        CONN_DEC_REF(connp);
                }
                ira->ira_ill = ill;
                ira->ira_rill = rill;
                ira->ira_flags &= ~IRAF_ICMP_ERROR;
                return;

        case IPPROTO_SCTP:
                up = (uint16_t *)((uchar_t *)ipha + hdr_length);
                /* Find a SCTP client stream for this packet. */
                ((uint16_t *)&ports)[0] = up[1];
                ((uint16_t *)&ports)[1] = up[0];

                ira->ira_flags |= IRAF_ICMP_ERROR;
                ip_fanout_sctp(mp, &ripha, NULL, ports, ira);
                ira->ira_flags &= ~IRAF_ICMP_ERROR;
                return;

        case IPPROTO_ESP:
        case IPPROTO_AH:
                if (!ipsec_loaded(ipss)) {
                        ip_proto_not_sup(mp, ira);
                        return;
                }

                if (ipha->ipha_protocol == IPPROTO_ESP)
                        mp = ipsecesp_icmp_error(mp, ira);
                else
                        mp = ipsecah_icmp_error(mp, ira);
                if (mp == NULL)
                        return;

                /* Just in case ipsec didn't preserve the NULL b_cont */
                if (mp->b_cont != NULL) {
                        if (!pullupmsg(mp, -1))
                                goto discard_pkt;
                }

                /*
                 * Note that ira_pktlen and ira_ip_hdr_length are no longer
                 * correct, but we don't use them any more here.
                 *
                 * If succesful, the mp has been modified to not include
                 * the ESP/AH header so we can fanout to the ULP's icmp
                 * error handler.
                 */
                if (mp->b_wptr - mp->b_rptr < IP_SIMPLE_HDR_LENGTH)
                        goto truncated;

                /* Verify the modified message before any further processes. */
                ipha = (ipha_t *)mp->b_rptr;
                hdr_length = IPH_HDR_LENGTH(ipha);
                icmph = (icmph_t *)&mp->b_rptr[hdr_length];
                if (!icmp_inbound_verify_v4(mp, icmph, ira)) {
                        freemsg(mp);
                        return;
                }

                icmp_inbound_error_fanout_v4(mp, icmph, ira);
                return;

        case IPPROTO_ENCAP: {
                /* Look for self-encapsulated packets that caused an error */
                ipha_t *in_ipha;

                /*
                 * Caller has verified that length has to be
                 * at least the size of IP header.
                 */
                ASSERT(hdr_length >= sizeof (ipha_t));
                /*
                 * Check the sanity of the inner IP header like
                 * we did for the outer header.
                 */
                in_ipha = (ipha_t *)((uchar_t *)ipha + hdr_length);
                if ((IPH_HDR_VERSION(in_ipha) != IPV4_VERSION)) {
                        goto discard_pkt;
                }
                if (IPH_HDR_LENGTH(in_ipha) < sizeof (ipha_t)) {
                        goto discard_pkt;
                }
                /* Check for Self-encapsulated tunnels */
                if (in_ipha->ipha_src == ipha->ipha_src &&
                    in_ipha->ipha_dst == ipha->ipha_dst) {

                        mp = icmp_inbound_self_encap_error_v4(mp, ipha,
                            in_ipha);
                        if (mp == NULL)
                                goto discard_pkt;

                        /*
                         * Just in case self_encap didn't preserve the NULL
                         * b_cont
                         */
                        if (mp->b_cont != NULL) {
                                if (!pullupmsg(mp, -1))
                                        goto discard_pkt;
                        }
                        /*
                         * Note that ira_pktlen and ira_ip_hdr_length are no
                         * longer correct, but we don't use them any more here.
                         */
                        if (mp->b_wptr - mp->b_rptr < IP_SIMPLE_HDR_LENGTH)
                                goto truncated;

                        /*
                         * Verify the modified message before any further
                         * processes.
                         */
                        ipha = (ipha_t *)mp->b_rptr;
                        hdr_length = IPH_HDR_LENGTH(ipha);
                        icmph = (icmph_t *)&mp->b_rptr[hdr_length];
                        if (!icmp_inbound_verify_v4(mp, icmph, ira)) {
                                freemsg(mp);
                                return;
                        }

                        /*
                         * The packet in error is self-encapsualted.
                         * And we are finding it further encapsulated
                         * which we could not have possibly generated.
                         */
                        if (ipha->ipha_protocol == IPPROTO_ENCAP) {
                                goto discard_pkt;
                        }
                        icmp_inbound_error_fanout_v4(mp, icmph, ira);
                        return;
                }
                /* No self-encapsulated */
        }
        /* FALLTHROUGH */
        case IPPROTO_IPV6:
                if ((connp = ipcl_iptun_classify_v4(&ripha.ipha_src,
                    &ripha.ipha_dst, ipst)) != NULL) {
                        ira->ira_flags |= IRAF_ICMP_ERROR;
                        connp->conn_recvicmp(connp, mp, NULL, ira);
                        CONN_DEC_REF(connp);
                        ira->ira_flags &= ~IRAF_ICMP_ERROR;
                        return;
                }
                /*
                 * No IP tunnel is interested, fallthrough and see
                 * if a raw socket will want it.
                 */
                /* FALLTHROUGH */
        default:
                ira->ira_flags |= IRAF_ICMP_ERROR;
                ip_fanout_proto_v4(mp, &ripha, ira);
                ira->ira_flags &= ~IRAF_ICMP_ERROR;
                return;
        }
        /* NOTREACHED */
discard_pkt:
        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
        ip1dbg(("icmp_inbound_error_fanout_v4: drop pkt\n"));
        ip_drop_input("ipIfStatsInDiscards", mp, ill);
        freemsg(mp);
        return;

truncated:
        /* We pulled up everthing already. Must be truncated */
        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInTruncatedPkts);
        ip_drop_input("ipIfStatsInTruncatedPkts", mp, ill);
        freemsg(mp);
}

/*
 * Common IP options parser.
 *
 * Setup routine: fill in *optp with options-parsing state, then
 * tail-call ipoptp_next to return the first option.
 */
uint8_t
ipoptp_first(ipoptp_t *optp, ipha_t *ipha)
{
        uint32_t totallen; /* total length of all options */

        totallen = ipha->ipha_version_and_hdr_length -
            (uint8_t)((IP_VERSION << 4) + IP_SIMPLE_HDR_LENGTH_IN_WORDS);
        totallen <<= 2;
        optp->ipoptp_next = (uint8_t *)(&ipha[1]);
        optp->ipoptp_end = optp->ipoptp_next + totallen;
        optp->ipoptp_flags = 0;
        return (ipoptp_next(optp));
}

/* Like above but without an ipha_t */
uint8_t
ipoptp_first2(ipoptp_t *optp, uint32_t totallen, uint8_t *opt)
{
        optp->ipoptp_next = opt;
        optp->ipoptp_end = optp->ipoptp_next + totallen;
        optp->ipoptp_flags = 0;
        return (ipoptp_next(optp));
}

/*
 * Common IP options parser: extract next option.
 */
uint8_t
ipoptp_next(ipoptp_t *optp)
{
        uint8_t *end = optp->ipoptp_end;
        uint8_t *cur = optp->ipoptp_next;
        uint8_t opt, len, pointer;

        /*
         * If cur > end already, then the ipoptp_end or ipoptp_next pointer
         * has been corrupted.
         */
        ASSERT(cur <= end);

        if (cur == end)
                return (IPOPT_EOL);

        opt = cur[IPOPT_OPTVAL];

        /*
         * Skip any NOP options.
         */
        while (opt == IPOPT_NOP) {
                cur++;
                if (cur == end)
                        return (IPOPT_EOL);
                opt = cur[IPOPT_OPTVAL];
        }

        if (opt == IPOPT_EOL)
                return (IPOPT_EOL);

        /*
         * Option requiring a length.
         */
        if ((cur + 1) >= end) {
                optp->ipoptp_flags |= IPOPTP_ERROR;
                return (IPOPT_EOL);
        }
        len = cur[IPOPT_OLEN];
        if (len < 2) {
                optp->ipoptp_flags |= IPOPTP_ERROR;
                return (IPOPT_EOL);
        }
        optp->ipoptp_cur = cur;
        optp->ipoptp_len = len;
        optp->ipoptp_next = cur + len;
        if (cur + len > end) {
                optp->ipoptp_flags |= IPOPTP_ERROR;
                return (IPOPT_EOL);
        }

        /*
         * For the options which require a pointer field, make sure
         * its there, and make sure it points to either something
         * inside this option, or the end of the option.
         */
        switch (opt) {
        case IPOPT_RR:
        case IPOPT_TS:
        case IPOPT_LSRR:
        case IPOPT_SSRR:
                if (len <= IPOPT_OFFSET) {
                        optp->ipoptp_flags |= IPOPTP_ERROR;
                        return (opt);
                }
                pointer = cur[IPOPT_OFFSET];
                if (pointer - 1 > len) {
                        optp->ipoptp_flags |= IPOPTP_ERROR;
                        return (opt);
                }
                break;
        }

        /*
         * Sanity check the pointer field based on the type of the
         * option.
         */
        switch (opt) {
        case IPOPT_RR:
        case IPOPT_SSRR:
        case IPOPT_LSRR:
                if (pointer < IPOPT_MINOFF_SR)
                        optp->ipoptp_flags |= IPOPTP_ERROR;
                break;
        case IPOPT_TS:
                if (pointer < IPOPT_MINOFF_IT)
                        optp->ipoptp_flags |= IPOPTP_ERROR;
                /*
                 * Note that the Internet Timestamp option also
                 * contains two four bit fields (the Overflow field,
                 * and the Flag field), which follow the pointer
                 * field.  We don't need to check that these fields
                 * fall within the length of the option because this
                 * was implicitely done above.  We've checked that the
                 * pointer value is at least IPOPT_MINOFF_IT, and that
                 * it falls within the option.  Since IPOPT_MINOFF_IT >
                 * IPOPT_POS_OV_FLG, we don't need the explicit check.
                 */
                ASSERT(len > IPOPT_POS_OV_FLG);
                break;
        }

        return (opt);
}

/*
 * Use the outgoing IP header to create an IP_OPTIONS option the way
 * it was passed down from the application.
 *
 * This is compatible with BSD in that it returns
 * the reverse source route with the final destination
 * as the last entry. The first 4 bytes of the option
 * will contain the final destination.
 */
int
ip_opt_get_user(conn_t *connp, uchar_t *buf)
{
        ipoptp_t        opts;
        uchar_t         *opt;
        uint8_t         optval;
        uint8_t         optlen;
        uint32_t        len = 0;
        uchar_t         *buf1 = buf;
        uint32_t        totallen;
        ipaddr_t        dst;
        ip_pkt_t        *ipp = &connp->conn_xmit_ipp;

        if (!(ipp->ipp_fields & IPPF_IPV4_OPTIONS))
                return (0);

        totallen = ipp->ipp_ipv4_options_len;
        if (totallen & 0x3)
                return (0);

        buf += IP_ADDR_LEN;     /* Leave room for final destination */
        len += IP_ADDR_LEN;
        bzero(buf1, IP_ADDR_LEN);

        dst = connp->conn_faddr_v4;

        for (optval = ipoptp_first2(&opts, totallen, ipp->ipp_ipv4_options);
            optval != IPOPT_EOL;
            optval = ipoptp_next(&opts)) {
                int     off;

                opt = opts.ipoptp_cur;
                if ((opts.ipoptp_flags & IPOPTP_ERROR) != 0) {
                        break;
                }
                optlen = opts.ipoptp_len;

                switch (optval) {
                case IPOPT_SSRR:
                case IPOPT_LSRR:

                        /*
                         * Insert destination as the first entry in the source
                         * route and move down the entries on step.
                         * The last entry gets placed at buf1.
                         */
                        buf[IPOPT_OPTVAL] = optval;
                        buf[IPOPT_OLEN] = optlen;
                        buf[IPOPT_OFFSET] = optlen;

                        off = optlen - IP_ADDR_LEN;
                        if (off < 0) {
                                /* No entries in source route */
                                break;
                        }
                        /* Last entry in source route if not already set */
                        if (dst == INADDR_ANY)
                                bcopy(opt + off, buf1, IP_ADDR_LEN);
                        off -= IP_ADDR_LEN;

                        while (off > 0) {
                                bcopy(opt + off,
                                    buf + off + IP_ADDR_LEN,
                                    IP_ADDR_LEN);
                                off -= IP_ADDR_LEN;
                        }
                        /* ipha_dst into first slot */
                        bcopy(&dst, buf + off + IP_ADDR_LEN,
                            IP_ADDR_LEN);
                        buf += optlen;
                        len += optlen;
                        break;

                default:
                        bcopy(opt, buf, optlen);
                        buf += optlen;
                        len += optlen;
                        break;
                }
        }
done:
        /* Pad the resulting options */
        while (len & 0x3) {
                *buf++ = IPOPT_EOL;
                len++;
        }
        return (len);
}

/*
 * Update any record route or timestamp options to include this host.
 * Reverse any source route option.
 * This routine assumes that the options are well formed i.e. that they
 * have already been checked.
 */
static void
icmp_options_update(ipha_t *ipha)
{
        ipoptp_t        opts;
        uchar_t         *opt;
        uint8_t         optval;
        ipaddr_t        src;            /* Our local address */
        ipaddr_t        dst;

        ip2dbg(("icmp_options_update\n"));
        src = ipha->ipha_src;
        dst = ipha->ipha_dst;

        for (optval = ipoptp_first(&opts, ipha);
            optval != IPOPT_EOL;
            optval = ipoptp_next(&opts)) {
                ASSERT((opts.ipoptp_flags & IPOPTP_ERROR) == 0);
                opt = opts.ipoptp_cur;
                ip2dbg(("icmp_options_update: opt %d, len %d\n",
                    optval, opts.ipoptp_len));
                switch (optval) {
                        int off1, off2;
                case IPOPT_SSRR:
                case IPOPT_LSRR:
                        /*
                         * Reverse the source route.  The first entry
                         * should be the next to last one in the current
                         * source route (the last entry is our address).
                         * The last entry should be the final destination.
                         */
                        off1 = IPOPT_MINOFF_SR - 1;
                        off2 = opt[IPOPT_OFFSET] - IP_ADDR_LEN - 1;
                        if (off2 < 0) {
                                /* No entries in source route */
                                ip1dbg((
                                    "icmp_options_update: bad src route\n"));
                                break;
                        }
                        bcopy((char *)opt + off2, &dst, IP_ADDR_LEN);
                        bcopy(&ipha->ipha_dst, (char *)opt + off2, IP_ADDR_LEN);
                        bcopy(&dst, &ipha->ipha_dst, IP_ADDR_LEN);
                        off2 -= IP_ADDR_LEN;

                        while (off1 < off2) {
                                bcopy((char *)opt + off1, &src, IP_ADDR_LEN);
                                bcopy((char *)opt + off2, (char *)opt + off1,
                                    IP_ADDR_LEN);
                                bcopy(&src, (char *)opt + off2, IP_ADDR_LEN);
                                off1 += IP_ADDR_LEN;
                                off2 -= IP_ADDR_LEN;
                        }
                        opt[IPOPT_OFFSET] = IPOPT_MINOFF_SR;
                        break;
                }
        }
}

/*
 * Process received ICMP Redirect messages.
 * Assumes the caller has verified that the headers are in the pulled up mblk.
 * Consumes mp.
 */
static void
icmp_redirect_v4(mblk_t *mp, ipha_t *ipha, icmph_t *icmph, ip_recv_attr_t *ira)
{
        ire_t           *ire, *nire;
        ire_t           *prev_ire;
        ipaddr_t        src, dst, gateway;
        ip_stack_t      *ipst = ira->ira_ill->ill_ipst;
        ipha_t          *inner_ipha;    /* Inner IP header */

        /* Caller already pulled up everything. */
        inner_ipha = (ipha_t *)&icmph[1];
        src = ipha->ipha_src;
        dst = inner_ipha->ipha_dst;
        gateway = icmph->icmph_rd_gateway;
        /* Make sure the new gateway is reachable somehow. */
        ire = ire_ftable_lookup_v4(gateway, 0, 0, IRE_ONLINK, NULL,
            ALL_ZONES, MATCH_IRE_TYPE, 0, ipst, NULL);
        /*
         * Make sure we had a route for the dest in question and that
         * that route was pointing to the old gateway (the source of the
         * redirect packet.)
         * We do longest match and then compare ire_gateway_addr below.
         */
        prev_ire = ire_ftable_lookup_v4(dst, 0, 0, 0, NULL, ALL_ZONES,
            MATCH_IRE_DSTONLY, 0, ipst, NULL);
        /*
         * Check that
         *      the redirect was not from ourselves
         *      the new gateway and the old gateway are directly reachable
         */
        if (prev_ire == NULL || ire == NULL ||
            (prev_ire->ire_type & (IRE_LOCAL|IRE_LOOPBACK)) ||
            (prev_ire->ire_flags & (RTF_REJECT|RTF_BLACKHOLE)) ||
            !(ire->ire_type & IRE_IF_ALL) ||
            prev_ire->ire_gateway_addr != src) {
                BUMP_MIB(&ipst->ips_icmp_mib, icmpInBadRedirects);
                ip_drop_input("icmpInBadRedirects - ire", mp, ira->ira_ill);
                freemsg(mp);
                if (ire != NULL)
                        ire_refrele(ire);
                if (prev_ire != NULL)
                        ire_refrele(prev_ire);
                return;
        }

        ire_refrele(prev_ire);
        ire_refrele(ire);

        /*
         * TODO: more precise handling for cases 0, 2, 3, the latter two
         * require TOS routing
         */
        switch (icmph->icmph_code) {
        case 0:
        case 1:
                /* TODO: TOS specificity for cases 2 and 3 */
        case 2:
        case 3:
                break;
        default:
                BUMP_MIB(&ipst->ips_icmp_mib, icmpInBadRedirects);
                ip_drop_input("icmpInBadRedirects - code", mp, ira->ira_ill);
                freemsg(mp);
                return;
        }
        /*
         * Create a Route Association.  This will allow us to remember that
         * someone we believe told us to use the particular gateway.
         */
        ire = ire_create(
            (uchar_t *)&dst,                    /* dest addr */
            (uchar_t *)&ip_g_all_ones,          /* mask */
            (uchar_t *)&gateway,                /* gateway addr */
            IRE_HOST,
            NULL,                               /* ill */
            ALL_ZONES,
            (RTF_DYNAMIC | RTF_GATEWAY | RTF_HOST),
            ipst);

        if (ire == NULL) {
                freemsg(mp);
                return;
        }
        nire = ire_add(ire);
        /* Check if it was a duplicate entry */
        if (nire != NULL && nire != ire) {
                ASSERT(nire->ire_identical_ref > 1);
                ire_delete(nire);
                ire_refrele(nire);
                nire = NULL;
        }
        ire = nire;
        if (ire != NULL) {
                ire_refrele(ire);               /* Held in ire_add */

                /* tell routing sockets that we received a redirect */
                ip_rts_change(RTM_REDIRECT, dst, gateway, IP_HOST_MASK, 0, src,
                    (RTF_DYNAMIC | RTF_GATEWAY | RTF_HOST), 0,
                    (RTA_DST | RTA_GATEWAY | RTA_NETMASK | RTA_AUTHOR), ipst);
        }

        /*
         * Delete any existing IRE_HOST type redirect ires for this destination.
         * This together with the added IRE has the effect of
         * modifying an existing redirect.
         */
        prev_ire = ire_ftable_lookup_v4(dst, 0, src, IRE_HOST, NULL,
            ALL_ZONES, (MATCH_IRE_GW | MATCH_IRE_TYPE), 0, ipst, NULL);
        if (prev_ire != NULL) {
                if (prev_ire ->ire_flags & RTF_DYNAMIC)
                        ire_delete(prev_ire);
                ire_refrele(prev_ire);
        }

        freemsg(mp);
}

/*
 * Generate an ICMP parameter problem message.
 * When called from ip_output side a minimal ip_recv_attr_t needs to be
 * constructed by the caller.
 */
static void
icmp_param_problem(mblk_t *mp, uint8_t ptr, ip_recv_attr_t *ira)
{
        icmph_t icmph;
        ip_stack_t      *ipst = ira->ira_ill->ill_ipst;

        mp = icmp_pkt_err_ok(mp, ira);
        if (mp == NULL)
                return;

        bzero(&icmph, sizeof (icmph_t));
        icmph.icmph_type = ICMP_PARAM_PROBLEM;
        icmph.icmph_pp_ptr = ptr;
        BUMP_MIB(&ipst->ips_icmp_mib, icmpOutParmProbs);
        icmp_pkt(mp, &icmph, sizeof (icmph_t), ira);
}

/*
 * Build and ship an IPv4 ICMP message using the packet data in mp, and
 * the ICMP header pointed to by "stuff".  (May be called as writer.)
 * Note: assumes that icmp_pkt_err_ok has been called to verify that
 * an icmp error packet can be sent.
 * Assigns an appropriate source address to the packet. If ipha_dst is
 * one of our addresses use it for source. Otherwise let ip_output_simple
 * pick the source address.
 */
static void
icmp_pkt(mblk_t *mp, void *stuff, size_t len, ip_recv_attr_t *ira)
{
        ipaddr_t dst;
        icmph_t *icmph;
        ipha_t  *ipha;
        uint_t  len_needed;
        size_t  msg_len;
        mblk_t  *mp1;
        ipaddr_t src;
        ire_t   *ire;
        ip_xmit_attr_t ixas;
        ip_stack_t *ipst = ira->ira_ill->ill_ipst;

        ipha = (ipha_t *)mp->b_rptr;

        bzero(&ixas, sizeof (ixas));
        ixas.ixa_flags = IXAF_BASIC_SIMPLE_V4;
        ixas.ixa_zoneid = ira->ira_zoneid;
        ixas.ixa_ifindex = 0;
        ixas.ixa_ipst = ipst;
        ixas.ixa_cred = kcred;
        ixas.ixa_cpid = NOPID;
        ixas.ixa_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;

        if (ira->ira_flags & IRAF_IPSEC_SECURE) {
                /*
                 * Apply IPsec based on how IPsec was applied to
                 * the packet that had the error.
                 *
                 * If it was an outbound packet that caused the ICMP
                 * error, then the caller will have setup the IRA
                 * appropriately.
                 */
                if (!ipsec_in_to_out(ira, &ixas, mp, ipha, NULL)) {
                        BUMP_MIB(&ipst->ips_ip_mib, ipIfStatsOutDiscards);
                        /* Note: mp already consumed and ip_drop_packet done */
                        return;
                }
        } else {
                /*
                 * This is in clear. The icmp message we are building
                 * here should go out in clear, independent of our policy.
                 */
                ixas.ixa_flags |= IXAF_NO_IPSEC;
        }

        /* Remember our eventual destination */
        dst = ipha->ipha_src;

        /*
         * If the packet was for one of our unicast addresses, make
         * sure we respond with that as the source. Otherwise
         * have ip_output_simple pick the source address.
         */
        ire = ire_ftable_lookup_v4(ipha->ipha_dst, 0, 0,
            (IRE_LOCAL|IRE_LOOPBACK), NULL, ira->ira_zoneid,
            MATCH_IRE_TYPE|MATCH_IRE_ZONEONLY, 0, ipst, NULL);
        if (ire != NULL) {
                ire_refrele(ire);
                src = ipha->ipha_dst;
        } else {
                src = INADDR_ANY;
                ixas.ixa_flags |= IXAF_SET_SOURCE;
        }

        /*
         * Check if we can send back more then 8 bytes in addition to
         * the IP header.  We try to send 64 bytes of data and the internal
         * header in the special cases of ipv4 encapsulated ipv4 or ipv6.
         */
        len_needed = IPH_HDR_LENGTH(ipha);
        if (ipha->ipha_protocol == IPPROTO_ENCAP ||
            ipha->ipha_protocol == IPPROTO_IPV6) {
                if (!pullupmsg(mp, -1)) {
                        BUMP_MIB(&ipst->ips_ip_mib, ipIfStatsOutDiscards);
                        ip_drop_output("ipIfStatsOutDiscards", mp, NULL);
                        freemsg(mp);
                        return;
                }
                ipha = (ipha_t *)mp->b_rptr;

                if (ipha->ipha_protocol == IPPROTO_ENCAP) {
                        len_needed += IPH_HDR_LENGTH(((uchar_t *)ipha +
                            len_needed));
                } else {
                        ip6_t *ip6h = (ip6_t *)((uchar_t *)ipha + len_needed);

                        ASSERT(ipha->ipha_protocol == IPPROTO_IPV6);
                        len_needed += ip_hdr_length_v6(mp, ip6h);
                }
        }
        len_needed += ipst->ips_ip_icmp_return;
        msg_len = msgdsize(mp);
        if (msg_len > len_needed) {
                (void) adjmsg(mp, len_needed - msg_len);
                msg_len = len_needed;
        }
        mp1 = allocb(sizeof (icmp_ipha) + len, BPRI_MED);
        if (mp1 == NULL) {
                BUMP_MIB(&ipst->ips_icmp_mib, icmpOutErrors);
                freemsg(mp);
                return;
        }
        mp1->b_cont = mp;
        mp = mp1;

        /*
         * Set IXAF_TRUSTED_ICMP so we can let the ICMP messages this
         * node generates be accepted in peace by all on-host destinations.
         * If we do NOT assume that all on-host destinations trust
         * self-generated ICMP messages, then rework here, ip6.c, and spd.c.
         * (Look for IXAF_TRUSTED_ICMP).
         */
        ixas.ixa_flags |= IXAF_TRUSTED_ICMP;

        ipha = (ipha_t *)mp->b_rptr;
        mp1->b_wptr = (uchar_t *)ipha + (sizeof (icmp_ipha) + len);
        *ipha = icmp_ipha;
        ipha->ipha_src = src;
        ipha->ipha_dst = dst;
        ipha->ipha_ttl = ipst->ips_ip_def_ttl;
        msg_len += sizeof (icmp_ipha) + len;
        if (msg_len > IP_MAXPACKET) {
                (void) adjmsg(mp, IP_MAXPACKET - msg_len);
                msg_len = IP_MAXPACKET;
        }
        ipha->ipha_length = htons((uint16_t)msg_len);
        icmph = (icmph_t *)&ipha[1];
        bcopy(stuff, icmph, len);
        icmph->icmph_checksum = 0;
        icmph->icmph_checksum = IP_CSUM(mp, (int32_t)sizeof (ipha_t), 0);
        BUMP_MIB(&ipst->ips_icmp_mib, icmpOutMsgs);

        (void) ip_output_simple(mp, &ixas);
        ixa_cleanup(&ixas);
}

/*
 * Determine if an ICMP error packet can be sent given the rate limit.
 * The limit consists of an average frequency (icmp_pkt_err_interval measured
 * in milliseconds) and a burst size. Burst size number of packets can
 * be sent arbitrarely closely spaced.
 * The state is tracked using two variables to implement an approximate
 * token bucket filter:
 *      icmp_pkt_err_last - lbolt value when the last burst started
 *      icmp_pkt_err_sent - number of packets sent in current burst
 */
boolean_t
icmp_err_rate_limit(ip_stack_t *ipst)
{
        clock_t now = TICK_TO_MSEC(ddi_get_lbolt());
        uint_t refilled; /* Number of packets refilled in tbf since last */
        /* Guard against changes by loading into local variable */
        uint_t err_interval = ipst->ips_ip_icmp_err_interval;

        if (err_interval == 0)
                return (B_FALSE);

        if (ipst->ips_icmp_pkt_err_last > now) {
                /* 100HZ lbolt in ms for 32bit arch wraps every 49.7 days */
                ipst->ips_icmp_pkt_err_last = 0;
                ipst->ips_icmp_pkt_err_sent = 0;
        }
        /*
         * If we are in a burst update the token bucket filter.
         * Update the "last" time to be close to "now" but make sure
         * we don't loose precision.
         */
        if (ipst->ips_icmp_pkt_err_sent != 0) {
                refilled = (now - ipst->ips_icmp_pkt_err_last)/err_interval;
                if (refilled > ipst->ips_icmp_pkt_err_sent) {
                        ipst->ips_icmp_pkt_err_sent = 0;
                } else {
                        ipst->ips_icmp_pkt_err_sent -= refilled;
                        ipst->ips_icmp_pkt_err_last += refilled * err_interval;
                }
        }
        if (ipst->ips_icmp_pkt_err_sent == 0) {
                /* Start of new burst */
                ipst->ips_icmp_pkt_err_last = now;
        }
        if (ipst->ips_icmp_pkt_err_sent < ipst->ips_ip_icmp_err_burst) {
                ipst->ips_icmp_pkt_err_sent++;
                ip1dbg(("icmp_err_rate_limit: %d sent in burst\n",
                    ipst->ips_icmp_pkt_err_sent));
                return (B_FALSE);
        }
        ip1dbg(("icmp_err_rate_limit: dropped\n"));
        return (B_TRUE);
}

/*
 * Check if it is ok to send an IPv4 ICMP error packet in
 * response to the IPv4 packet in mp.
 * Free the message and return null if no
 * ICMP error packet should be sent.
 */
static mblk_t *
icmp_pkt_err_ok(mblk_t *mp, ip_recv_attr_t *ira)
{
        ip_stack_t      *ipst = ira->ira_ill->ill_ipst;
        icmph_t *icmph;
        ipha_t  *ipha;
        uint_t  len_needed;

        if (!mp)
                return (NULL);
        ipha = (ipha_t *)mp->b_rptr;
        if (ip_csum_hdr(ipha)) {
                BUMP_MIB(&ipst->ips_ip_mib, ipIfStatsInCksumErrs);
                ip_drop_input("ipIfStatsInCksumErrs", mp, NULL);
                freemsg(mp);
                return (NULL);
        }
        if (ip_type_v4(ipha->ipha_dst, ipst) == IRE_BROADCAST ||
            ip_type_v4(ipha->ipha_src, ipst) == IRE_BROADCAST ||
            CLASSD(ipha->ipha_dst) ||
            CLASSD(ipha->ipha_src) ||
            (ntohs(ipha->ipha_fragment_offset_and_flags) & IPH_OFFSET)) {
                /* Note: only errors to the fragment with offset 0 */
                BUMP_MIB(&ipst->ips_icmp_mib, icmpOutDrops);
                freemsg(mp);
                return (NULL);
        }
        if (ipha->ipha_protocol == IPPROTO_ICMP) {
                /*
                 * Check the ICMP type.  RFC 1122 sez:  don't send ICMP
                 * errors in response to any ICMP errors.
                 */
                len_needed = IPH_HDR_LENGTH(ipha) + ICMPH_SIZE;
                if (mp->b_wptr - mp->b_rptr < len_needed) {
                        if (!pullupmsg(mp, len_needed)) {
                                BUMP_MIB(&ipst->ips_icmp_mib, icmpInErrors);
                                freemsg(mp);
                                return (NULL);
                        }
                        ipha = (ipha_t *)mp->b_rptr;
                }
                icmph = (icmph_t *)
                    (&((char *)ipha)[IPH_HDR_LENGTH(ipha)]);
                switch (icmph->icmph_type) {
                case ICMP_DEST_UNREACHABLE:
                case ICMP_SOURCE_QUENCH:
                case ICMP_TIME_EXCEEDED:
                case ICMP_PARAM_PROBLEM:
                case ICMP_REDIRECT:
                        BUMP_MIB(&ipst->ips_icmp_mib, icmpOutDrops);
                        freemsg(mp);
                        return (NULL);
                default:
                        break;
                }
        }
        if (icmp_err_rate_limit(ipst)) {
                /*
                 * Only send ICMP error packets every so often.
                 * This should be done on a per port/source basis,
                 * but for now this will suffice.
                 */
                freemsg(mp);
                return (NULL);
        }
        return (mp);
}

/*
 * Called when a packet was sent out the same link that it arrived on.
 * Check if it is ok to send a redirect and then send it.
 */
void
ip_send_potential_redirect_v4(mblk_t *mp, ipha_t *ipha, ire_t *ire,
    ip_recv_attr_t *ira)
{
        ip_stack_t      *ipst = ira->ira_ill->ill_ipst;
        ipaddr_t        src, nhop;
        mblk_t          *mp1;
        ire_t           *nhop_ire;

        /*
         * Check the source address to see if it originated
         * on the same logical subnet it is going back out on.
         * If so, we should be able to send it a redirect.
         * Avoid sending a redirect if the destination
         * is directly connected (i.e., we matched an IRE_ONLINK),
         * or if the packet was source routed out this interface.
         *
         * We avoid sending a redirect if the
         * destination is directly connected
         * because it is possible that multiple
         * IP subnets may have been configured on
         * the link, and the source may not
         * be on the same subnet as ip destination,
         * even though they are on the same
         * physical link.
         */
        if ((ire->ire_type & IRE_ONLINK) ||
            ip_source_routed(ipha, ipst))
                return;

        nhop_ire = ire_nexthop(ire);
        if (nhop_ire == NULL)
                return;

        nhop = nhop_ire->ire_addr;

        if (nhop_ire->ire_type & IRE_IF_CLONE) {
                ire_t   *ire2;

                /* Follow ire_dep_parent to find non-clone IRE_INTERFACE */
                mutex_enter(&nhop_ire->ire_lock);
                ire2 = nhop_ire->ire_dep_parent;
                if (ire2 != NULL)
                        ire_refhold(ire2);
                mutex_exit(&nhop_ire->ire_lock);
                ire_refrele(nhop_ire);
                nhop_ire = ire2;
        }
        if (nhop_ire == NULL)
                return;

        ASSERT(!(nhop_ire->ire_type & IRE_IF_CLONE));

        src = ipha->ipha_src;

        /*
         * We look at the interface ire for the nexthop,
         * to see if ipha_src is in the same subnet
         * as the nexthop.
         */
        if ((src & nhop_ire->ire_mask) == (nhop & nhop_ire->ire_mask)) {
                /*
                 * The source is directly connected.
                 */
                mp1 = copymsg(mp);
                if (mp1 != NULL) {
                        icmp_send_redirect(mp1, nhop, ira);
                }
        }
        ire_refrele(nhop_ire);
}

/*
 * Generate an ICMP redirect message.
 */
static void
icmp_send_redirect(mblk_t *mp, ipaddr_t gateway, ip_recv_attr_t *ira)
{
        icmph_t icmph;
        ip_stack_t *ipst = ira->ira_ill->ill_ipst;

        mp = icmp_pkt_err_ok(mp, ira);
        if (mp == NULL)
                return;

        bzero(&icmph, sizeof (icmph_t));
        icmph.icmph_type = ICMP_REDIRECT;
        icmph.icmph_code = 1;
        icmph.icmph_rd_gateway = gateway;
        BUMP_MIB(&ipst->ips_icmp_mib, icmpOutRedirects);
        icmp_pkt(mp, &icmph, sizeof (icmph_t), ira);
}

/*
 * Generate an ICMP time exceeded message.
 */
void
icmp_time_exceeded(mblk_t *mp, uint8_t code, ip_recv_attr_t *ira)
{
        icmph_t icmph;
        ip_stack_t *ipst = ira->ira_ill->ill_ipst;

        mp = icmp_pkt_err_ok(mp, ira);
        if (mp == NULL)
                return;

        bzero(&icmph, sizeof (icmph_t));
        icmph.icmph_type = ICMP_TIME_EXCEEDED;
        icmph.icmph_code = code;
        BUMP_MIB(&ipst->ips_icmp_mib, icmpOutTimeExcds);
        icmp_pkt(mp, &icmph, sizeof (icmph_t), ira);
}

/*
 * Generate an ICMP unreachable message.
 * When called from ip_output side a minimal ip_recv_attr_t needs to be
 * constructed by the caller.
 */
void
icmp_unreachable(mblk_t *mp, uint8_t code, ip_recv_attr_t *ira)
{
        icmph_t icmph;
        ip_stack_t *ipst = ira->ira_ill->ill_ipst;

        mp = icmp_pkt_err_ok(mp, ira);
        if (mp == NULL)
                return;

        bzero(&icmph, sizeof (icmph_t));
        icmph.icmph_type = ICMP_DEST_UNREACHABLE;
        icmph.icmph_code = code;
        BUMP_MIB(&ipst->ips_icmp_mib, icmpOutDestUnreachs);
        icmp_pkt(mp, &icmph, sizeof (icmph_t), ira);
}

/*
 * Latch in the IPsec state for a stream based the policy in the listener
 * and the actions in the ip_recv_attr_t.
 * Called directly from TCP and SCTP.
 */
boolean_t
ip_ipsec_policy_inherit(conn_t *connp, conn_t *lconnp, ip_recv_attr_t *ira)
{
        ASSERT(lconnp->conn_policy != NULL);
        ASSERT(connp->conn_policy == NULL);

        IPPH_REFHOLD(lconnp->conn_policy);
        connp->conn_policy = lconnp->conn_policy;

        if (ira->ira_ipsec_action != NULL) {
                if (connp->conn_latch == NULL) {
                        connp->conn_latch = iplatch_create();
                        if (connp->conn_latch == NULL)
                                return (B_FALSE);
                }
                ipsec_latch_inbound(connp, ira);
        }
        return (B_TRUE);
}

/*
 * Verify whether or not the IP address is a valid local address.
 * Could be a unicast, including one for a down interface.
 * If allow_mcbc then a multicast or broadcast address is also
 * acceptable.
 *
 * In the case of a broadcast/multicast address, however, the
 * upper protocol is expected to reset the src address
 * to zero when we return IPVL_MCAST/IPVL_BCAST so that
 * no packets are emitted with broadcast/multicast address as
 * source address (that violates hosts requirements RFC 1122)
 * The addresses valid for bind are:
 *      (1) - INADDR_ANY (0)
 *      (2) - IP address of an UP interface
 *      (3) - IP address of a DOWN interface
 *      (4) - valid local IP broadcast addresses. In this case
 *      the conn will only receive packets destined to
 *      the specified broadcast address.
 *      (5) - a multicast address. In this case
 *      the conn will only receive packets destined to
 *      the specified multicast address. Note: the
 *      application still has to issue an
 *      IP_ADD_MEMBERSHIP socket option.
 *
 * In all the above cases, the bound address must be valid in the current zone.
 * When the address is loopback, multicast or broadcast, there might be many
 * matching IREs so bind has to look up based on the zone.
 */
ip_laddr_t
ip_laddr_verify_v4(ipaddr_t src_addr, zoneid_t zoneid,
    ip_stack_t *ipst, boolean_t allow_mcbc)
{
        ire_t *src_ire;

        ASSERT(src_addr != INADDR_ANY);

        src_ire = ire_ftable_lookup_v4(src_addr, 0, 0, 0,
            NULL, zoneid, MATCH_IRE_ZONEONLY, 0, ipst, NULL);

        /*
         * If an address other than in6addr_any is requested,
         * we verify that it is a valid address for bind
         * Note: Following code is in if-else-if form for
         * readability compared to a condition check.
         */
        if (src_ire != NULL && (src_ire->ire_type & (IRE_LOCAL|IRE_LOOPBACK))) {
                /*
                 * (2) Bind to address of local UP interface
                 */
                ire_refrele(src_ire);
                return (IPVL_UNICAST_UP);
        } else if (src_ire != NULL && src_ire->ire_type & IRE_BROADCAST) {
                /*
                 * (4) Bind to broadcast address
                 */
                ire_refrele(src_ire);
                if (allow_mcbc)
                        return (IPVL_BCAST);
                else
                        return (IPVL_BAD);
        } else if (CLASSD(src_addr)) {
                /* (5) bind to multicast address. */
                if (src_ire != NULL)
                        ire_refrele(src_ire);

                if (allow_mcbc)
                        return (IPVL_MCAST);
                else
                        return (IPVL_BAD);
        } else {
                ipif_t *ipif;

                /*
                 * (3) Bind to address of local DOWN interface?
                 * (ipif_lookup_addr() looks up all interfaces
                 * but we do not get here for UP interfaces
                 * - case (2) above)
                 */
                if (src_ire != NULL)
                        ire_refrele(src_ire);

                ipif = ipif_lookup_addr(src_addr, NULL, zoneid, ipst);
                if (ipif == NULL)
                        return (IPVL_BAD);

                /* Not a useful source? */
                if (ipif->ipif_flags & (IPIF_NOLOCAL | IPIF_ANYCAST)) {
                        ipif_refrele(ipif);
                        return (IPVL_BAD);
                }
                ipif_refrele(ipif);
                return (IPVL_UNICAST_DOWN);
        }
}

/*
 * Insert in the bind fanout for IPv4 and IPv6.
 * The caller should already have used ip_laddr_verify_v*() before calling
 * this.
 */
int
ip_laddr_fanout_insert(conn_t *connp)
{
        int             error;

        /*
         * Allow setting new policies. For example, disconnects result
         * in us being called. As we would have set conn_policy_cached
         * to B_TRUE before, we should set it to B_FALSE, so that policy
         * can change after the disconnect.
         */
        connp->conn_policy_cached = B_FALSE;

        return (ipcl_bind_insert(connp));
}

/*
 * Verify that both the source and destination addresses are valid. If
 * IPDF_VERIFY_DST is not set, then the destination address may be unreachable,
 * i.e. have no route to it.  Protocols like TCP want to verify destination
 * reachability, while tunnels do not.
 *
 * Determine the route, the interface, and (optionally) the source address
 * to use to reach a given destination.
 * Note that we allow connect to broadcast and multicast addresses when
 * IPDF_ALLOW_MCBC is set.
 * first_hop and dst_addr are normally the same, but if source routing
 * they will differ; in that case the first_hop is what we'll use for the
 * routing lookup but the dce checks will be done on dst_addr,
 *
 * If uinfo is set, then we fill in the best available information
 * we have for the destination. This is based on (in priority order) any
 * metrics and path MTU stored in a dce_t, route metrics, and finally the
 * ill_mtu/ill_mc_mtu.
 */
int
ip_set_destination_v4(ipaddr_t *src_addrp, ipaddr_t dst_addr, ipaddr_t firsthop,
    ip_xmit_attr_t *ixa, iulp_t *uinfo, uint32_t flags)
{
        ire_t           *ire = NULL;
        int             error = 0;
        ipaddr_t        setsrc;                         /* RTF_SETSRC */
        zoneid_t        zoneid = ixa->ixa_zoneid;       /* Honors SO_ALLZONES */
        ip_stack_t      *ipst = ixa->ixa_ipst;
        dce_t           *dce;
        uint_t          pmtu;
        uint_t          generation;
        nce_t           *nce;
        ill_t           *ill = NULL;

        ASSERT(ixa->ixa_flags & IXAF_IS_IPV4);

        /*
         * We never send to zero; the ULPs map it to the loopback address.
         * We can't allow it since we use zero to mean unitialized in some
         * places.
         */
        ASSERT(dst_addr != INADDR_ANY);

        setsrc = INADDR_ANY;
        /*
         * Select a route; For IPMP interfaces, we would only select
         * a "hidden" route (i.e., going through a specific under_ill)
         * if ixa_ifindex has been specified.
         */
        ire = ip_select_route_v4(firsthop, *src_addrp, ixa,
            &generation, &setsrc, &error);
        ASSERT(ire != NULL);    /* IRE_NOROUTE if none found */
        if (error != 0)
                goto bad_addr;

        /*
         * ire can't be a broadcast or multicast unless IPDF_ALLOW_MCBC is set.
         * If IPDF_VERIFY_DST is set, the destination must be reachable;
         * Otherwise the destination needn't be reachable.
         *
         * If we match on a reject or black hole, then we've got a
         * local failure.  May as well fail out the connect() attempt,
         * since it's never going to succeed.
         */
        if (ire->ire_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
                /*
                 * If we're verifying destination reachability, we always want
                 * to complain here.
                 *
                 * If we're not verifying destination reachability but the
                 * destination has a route, we still want to fail on the
                 * temporary address and broadcast address tests.
                 *
                 * In both cases do we let the code continue so some reasonable
                 * information is returned to the caller. That enables the
                 * caller to use (and even cache) the IRE. conn_ip_ouput will
                 * use the generation mismatch path to check for the unreachable
                 * case thereby avoiding any specific check in the main path.
                 */
                ASSERT(generation == IRE_GENERATION_VERIFY);
                if (flags & IPDF_VERIFY_DST) {
                        /*
                         * Set errno but continue to set up ixa_ire to be
                         * the RTF_REJECT|RTF_BLACKHOLE IRE.
                         * That allows callers to use ip_output to get an
                         * ICMP error back.
                         */
                        if (!(ire->ire_type & IRE_HOST))
                                error = ENETUNREACH;
                        else
                                error = EHOSTUNREACH;
                }
        }

        if ((ire->ire_type & (IRE_BROADCAST|IRE_MULTICAST)) &&
            !(flags & IPDF_ALLOW_MCBC)) {
                ire_refrele(ire);
                ire = ire_reject(ipst, B_FALSE);
                generation = IRE_GENERATION_VERIFY;
                error = ENETUNREACH;
        }

        /* Cache things */
        if (ixa->ixa_ire != NULL)
                ire_refrele_notr(ixa->ixa_ire);
#ifdef DEBUG
        ire_refhold_notr(ire);
        ire_refrele(ire);
#endif
        ixa->ixa_ire = ire;
        ixa->ixa_ire_generation = generation;

        /*
         * Ensure that ixa_dce is always set any time that ixa_ire is set,
         * since some callers will send a packet to conn_ip_output() even if
         * there's an error.
         */
        if (flags & IPDF_UNIQUE_DCE) {
                /* Fallback to the default dce if allocation fails */
                dce = dce_lookup_and_add_v4(dst_addr, ipst);
                if (dce != NULL)
                        generation = dce->dce_generation;
                else
                        dce = dce_lookup_v4(dst_addr, ipst, &generation);
        } else {
                dce = dce_lookup_v4(dst_addr, ipst, &generation);
        }
        ASSERT(dce != NULL);
        if (ixa->ixa_dce != NULL)
                dce_refrele_notr(ixa->ixa_dce);
#ifdef DEBUG
        dce_refhold_notr(dce);
        dce_refrele(dce);
#endif
        ixa->ixa_dce = dce;
        ixa->ixa_dce_generation = generation;
        ixa->ixa_postfragfn = ire->ire_postfragfn;

        if (!(ire->ire_flags & (RTF_REJECT|RTF_BLACKHOLE))) {
                /* Get an nce to cache. */
                nce = ire_to_nce(ire, firsthop, NULL);
                if (nce == NULL) {
                        /* Allocation failure? */
                        ixa->ixa_ire_generation = IRE_GENERATION_VERIFY;
                } else {
                        if (ixa->ixa_nce != NULL)
                                nce_refrele(ixa->ixa_nce);
                        ixa->ixa_nce = nce;
                }
        }

        /*
         * If the source address is a loopback address, the
         * destination had best be local or multicast.
         * If we are sending to an IRE_LOCAL using a loopback source then
         * it had better be the same zoneid.
         */
        if (*src_addrp == htonl(INADDR_LOOPBACK)) {
                if ((ire->ire_type & IRE_LOCAL) && ire->ire_zoneid != zoneid) {
                        ire = NULL;     /* Stored in ixa_ire */
                        error = EADDRNOTAVAIL;
                        goto bad_addr;
                }
                if (!(ire->ire_type & (IRE_LOOPBACK|IRE_LOCAL|IRE_MULTICAST))) {
                        ire = NULL;     /* Stored in ixa_ire */
                        error = EADDRNOTAVAIL;
                        goto bad_addr;
                }
        }
        if (ire->ire_type & IRE_BROADCAST) {
                /*
                 * If the ULP didn't have a specified source, then we
                 * make sure we reselect the source when sending
                 * broadcasts out different interfaces.
                 */
                if (flags & IPDF_SELECT_SRC)
                        ixa->ixa_flags |= IXAF_SET_SOURCE;
                else
                        ixa->ixa_flags &= ~IXAF_SET_SOURCE;
        }

        /*
         * Does the caller want us to pick a source address?
         */
        if (flags & IPDF_SELECT_SRC) {
                ipaddr_t        src_addr;

                /*
                 * We use use ire_nexthop_ill to avoid the under ipmp
                 * interface for source address selection. Note that for ipmp
                 * probe packets, ixa_ifindex would have been specified, and
                 * the ip_select_route() invocation would have picked an ire
                 * will ire_ill pointing at an under interface.
                 */
                ill = ire_nexthop_ill(ire);

                /* If unreachable we have no ill but need some source */
                if (ill == NULL) {
                        src_addr = htonl(INADDR_LOOPBACK);
                        /* Make sure we look for a better source address */
                        generation = SRC_GENERATION_VERIFY;
                } else {
                        error = ip_select_source_v4(ill, setsrc, dst_addr,
                            ixa->ixa_multicast_ifaddr, zoneid,
                            ipst, &src_addr, &generation, NULL);
                        if (error != 0) {
                                ire = NULL;     /* Stored in ixa_ire */
                                goto bad_addr;
                        }
                }

                /*
                 * We allow the source address to to down.
                 * However, we check that we don't use the loopback address
                 * as a source when sending out on the wire.
                 */
                if ((src_addr == htonl(INADDR_LOOPBACK)) &&
                    !(ire->ire_type & (IRE_LOCAL|IRE_LOOPBACK|IRE_MULTICAST)) &&
                    !(ire->ire_flags & (RTF_REJECT|RTF_BLACKHOLE))) {
                        ire = NULL;     /* Stored in ixa_ire */
                        error = EADDRNOTAVAIL;
                        goto bad_addr;
                }

                *src_addrp = src_addr;
                ixa->ixa_src_generation = generation;
        }

        /*
         * Make sure we don't leave an unreachable ixa_nce in place
         * since ip_select_route is used when we unplumb i.e., remove
         * references on ixa_ire, ixa_nce, and ixa_dce.
         */
        nce = ixa->ixa_nce;
        if (nce != NULL && nce->nce_is_condemned) {
                nce_refrele(nce);
                ixa->ixa_nce = NULL;
                ixa->ixa_ire_generation = IRE_GENERATION_VERIFY;
        }

        /*
         * The caller has set IXAF_PMTU_DISCOVERY if path MTU is desired.
         * However, we can't do it for IPv4 multicast or broadcast.
         */
        if (ire->ire_type & (IRE_BROADCAST|IRE_MULTICAST))
                ixa->ixa_flags &= ~IXAF_PMTU_DISCOVERY;

        /*
         * Set initial value for fragmentation limit. Either conn_ip_output
         * or ULP might updates it when there are routing changes.
         * Handles a NULL ixa_ire->ire_ill or a NULL ixa_nce for RTF_REJECT.
         */
        pmtu = ip_get_pmtu(ixa);
        ixa->ixa_fragsize = pmtu;
        /* Make sure ixa_fragsize and ixa_pmtu remain identical */
        if (ixa->ixa_flags & IXAF_VERIFY_PMTU)
                ixa->ixa_pmtu = pmtu;

        /*
         * Extract information useful for some transports.
         * First we look for DCE metrics. Then we take what we have in
         * the metrics in the route, where the offlink is used if we have
         * one.
         */
        if (uinfo != NULL) {
                bzero(uinfo, sizeof (*uinfo));

                if (dce->dce_flags & DCEF_UINFO)
                        *uinfo = dce->dce_uinfo;

                rts_merge_metrics(uinfo, &ire->ire_metrics);

                /* Allow ire_metrics to decrease the path MTU from above */
                if (uinfo->iulp_mtu == 0 || uinfo->iulp_mtu > pmtu)
                        uinfo->iulp_mtu = pmtu;

                uinfo->iulp_localnet = (ire->ire_type & IRE_ONLINK) != 0;
                uinfo->iulp_loopback = (ire->ire_type & IRE_LOOPBACK) != 0;
                uinfo->iulp_local = (ire->ire_type & IRE_LOCAL) != 0;
        }

        if (ill != NULL)
                ill_refrele(ill);

        return (error);

bad_addr:
        if (ire != NULL)
                ire_refrele(ire);

        if (ill != NULL)
                ill_refrele(ill);

        /*
         * Make sure we don't leave an unreachable ixa_nce in place
         * since ip_select_route is used when we unplumb i.e., remove
         * references on ixa_ire, ixa_nce, and ixa_dce.
         */
        nce = ixa->ixa_nce;
        if (nce != NULL && nce->nce_is_condemned) {
                nce_refrele(nce);
                ixa->ixa_nce = NULL;
                ixa->ixa_ire_generation = IRE_GENERATION_VERIFY;
        }

        return (error);
}


/*
 * Get the base MTU for the case when path MTU discovery is not used.
 * Takes the MTU of the IRE into account.
 */
uint_t
ip_get_base_mtu(ill_t *ill, ire_t *ire)
{
        uint_t mtu;
        uint_t iremtu = ire->ire_metrics.iulp_mtu;

        if (ire->ire_type & (IRE_MULTICAST|IRE_BROADCAST))
                mtu = ill->ill_mc_mtu;
        else
                mtu = ill->ill_mtu;

        if (iremtu != 0 && iremtu < mtu)
                mtu = iremtu;

        return (mtu);
}

/*
 * Get the PMTU for the attributes. Handles both IPv4 and IPv6.
 * Assumes that ixa_ire, dce, and nce have already been set up.
 *
 * The caller has set IXAF_PMTU_DISCOVERY if path MTU discovery is desired.
 * We avoid path MTU discovery if it is disabled with ndd.
 * Furtermore, if the path MTU is too small, then we don't set DF for IPv4.
 *
 * NOTE: We also used to turn it off for source routed packets. That
 * is no longer required since the dce is per final destination.
 */
uint_t
ip_get_pmtu(ip_xmit_attr_t *ixa)
{
        ip_stack_t      *ipst = ixa->ixa_ipst;
        dce_t           *dce;
        nce_t           *nce;
        ire_t           *ire;
        uint_t          pmtu;

        ire = ixa->ixa_ire;
        dce = ixa->ixa_dce;
        nce = ixa->ixa_nce;

        /*
         * If path MTU discovery has been turned off by ndd, then we ignore
         * any dce_pmtu and for IPv4 we will not set DF.
         */
        if (!ipst->ips_ip_path_mtu_discovery)
                ixa->ixa_flags &= ~IXAF_PMTU_DISCOVERY;

        pmtu = IP_MAXPACKET;
        /*
         * Decide whether whether IPv4 sets DF
         * For IPv6 "no DF" means to use the 1280 mtu
         */
        if (ixa->ixa_flags & IXAF_PMTU_DISCOVERY) {
                ixa->ixa_flags |= IXAF_PMTU_IPV4_DF;
        } else {
                ixa->ixa_flags &= ~IXAF_PMTU_IPV4_DF;
                if (!(ixa->ixa_flags & IXAF_IS_IPV4))
                        pmtu = IPV6_MIN_MTU;
        }

        /* Check if the PMTU is to old before we use it */
        if ((dce->dce_flags & DCEF_PMTU) &&
            TICK_TO_SEC(ddi_get_lbolt64()) - dce->dce_last_change_time >
            ipst->ips_ip_pathmtu_interval) {
                /*
                 * Older than 20 minutes. Drop the path MTU information.
                 */
                mutex_enter(&dce->dce_lock);
                dce->dce_flags &= ~(DCEF_PMTU|DCEF_TOO_SMALL_PMTU);
                dce->dce_last_change_time = TICK_TO_SEC(ddi_get_lbolt64());
                mutex_exit(&dce->dce_lock);
                dce_increment_generation(dce);
        }

        /* The metrics on the route can lower the path MTU */
        if (ire->ire_metrics.iulp_mtu != 0 &&
            ire->ire_metrics.iulp_mtu < pmtu)
                pmtu = ire->ire_metrics.iulp_mtu;

        /*
         * If the path MTU is smaller than some minimum, we still use dce_pmtu
         * above (would be 576 for IPv4 and 1280 for IPv6), but we clear
         * IXAF_PMTU_IPV4_DF so that we avoid setting DF for IPv4.
         */
        if (ixa->ixa_flags & IXAF_PMTU_DISCOVERY) {
                if (dce->dce_flags & DCEF_PMTU) {
                        if (dce->dce_pmtu < pmtu)
                                pmtu = dce->dce_pmtu;

                        if (dce->dce_flags & DCEF_TOO_SMALL_PMTU) {
                                ixa->ixa_flags |= IXAF_PMTU_TOO_SMALL;
                                ixa->ixa_flags &= ~IXAF_PMTU_IPV4_DF;
                        } else {
                                ixa->ixa_flags &= ~IXAF_PMTU_TOO_SMALL;
                                ixa->ixa_flags |= IXAF_PMTU_IPV4_DF;
                        }
                } else {
                        ixa->ixa_flags &= ~IXAF_PMTU_TOO_SMALL;
                        ixa->ixa_flags |= IXAF_PMTU_IPV4_DF;
                }
        }

        /*
         * If we have an IRE_LOCAL we use the loopback mtu instead of
         * the ill for going out the wire i.e., IRE_LOCAL gets the same
         * mtu as IRE_LOOPBACK.
         */
        if (ire->ire_type & (IRE_LOCAL|IRE_LOOPBACK)) {
                uint_t loopback_mtu;

                loopback_mtu = (ire->ire_ipversion == IPV6_VERSION) ?
                    ip_loopback_mtu_v6plus : ip_loopback_mtuplus;

                if (loopback_mtu < pmtu)
                        pmtu = loopback_mtu;
        } else if (nce != NULL) {
                /*
                 * Make sure we don't exceed the interface MTU.
                 * In the case of RTF_REJECT or RTF_BLACKHOLE we might not have
                 * an ill. We'd use the above IP_MAXPACKET in that case just
                 * to tell the transport something larger than zero.
                 */
                if (ire->ire_type & (IRE_MULTICAST|IRE_BROADCAST)) {
                        if (nce->nce_common->ncec_ill->ill_mc_mtu < pmtu)
                                pmtu = nce->nce_common->ncec_ill->ill_mc_mtu;
                        if (nce->nce_common->ncec_ill != nce->nce_ill &&
                            nce->nce_ill->ill_mc_mtu < pmtu) {
                                /*
                                 * for interfaces in an IPMP group, the mtu of
                                 * the nce_ill (under_ill) could be different
                                 * from the mtu of the ncec_ill, so we take the
                                 * min of the two.
                                 */
                                pmtu = nce->nce_ill->ill_mc_mtu;
                        }
                } else {
                        if (nce->nce_common->ncec_ill->ill_mtu < pmtu)
                                pmtu = nce->nce_common->ncec_ill->ill_mtu;
                        if (nce->nce_common->ncec_ill != nce->nce_ill &&
                            nce->nce_ill->ill_mtu < pmtu) {
                                /*
                                 * for interfaces in an IPMP group, the mtu of
                                 * the nce_ill (under_ill) could be different
                                 * from the mtu of the ncec_ill, so we take the
                                 * min of the two.
                                 */
                                pmtu = nce->nce_ill->ill_mtu;
                        }
                }
        }

        /*
         * Handle the IPV6_USE_MIN_MTU socket option or ancillary data.
         * Only applies to IPv6.
         */
        if (!(ixa->ixa_flags & IXAF_IS_IPV4)) {
                if (ixa->ixa_flags & IXAF_USE_MIN_MTU) {
                        switch (ixa->ixa_use_min_mtu) {
                        case IPV6_USE_MIN_MTU_MULTICAST:
                                if (ire->ire_type & IRE_MULTICAST)
                                        pmtu = IPV6_MIN_MTU;
                                break;
                        case IPV6_USE_MIN_MTU_ALWAYS:
                                pmtu = IPV6_MIN_MTU;
                                break;
                        case IPV6_USE_MIN_MTU_NEVER:
                                break;
                        }
                } else {
                        /* Default is IPV6_USE_MIN_MTU_MULTICAST */
                        if (ire->ire_type & IRE_MULTICAST)
                                pmtu = IPV6_MIN_MTU;
                }
        }

        return (pmtu);
}

/*
 * Carve "len" bytes out of an mblk chain, consuming any we empty, and duping
 * the final piece where we don't.  Return a pointer to the first mblk in the
 * result, and update the pointer to the next mblk to chew on.  If anything
 * goes wrong (i.e., dupb fails), we waste everything in sight and return a
 * NULL pointer.
 */
mblk_t *
ip_carve_mp(mblk_t **mpp, ssize_t len)
{
        mblk_t  *mp0;
        mblk_t  *mp1;
        mblk_t  *mp2;

        if (!len || !mpp || !(mp0 = *mpp))
                return (NULL);
        /* If we aren't going to consume the first mblk, we need a dup. */
        if (mp0->b_wptr - mp0->b_rptr > len) {
                mp1 = dupb(mp0);
                if (mp1) {
                        /* Partition the data between the two mblks. */
                        mp1->b_wptr = mp1->b_rptr + len;
                        mp0->b_rptr = mp1->b_wptr;
                        /*
                         * after adjustments if mblk not consumed is now
                         * unaligned, try to align it. If this fails free
                         * all messages and let upper layer recover.
                         */
                        if (!OK_32PTR(mp0->b_rptr)) {
                                if (!pullupmsg(mp0, -1)) {
                                        freemsg(mp0);
                                        freemsg(mp1);
                                        *mpp = NULL;
                                        return (NULL);
                                }
                        }
                }
                return (mp1);
        }
        /* Eat through as many mblks as we need to get len bytes. */
        len -= mp0->b_wptr - mp0->b_rptr;
        for (mp2 = mp1 = mp0; (mp2 = mp2->b_cont) != 0 && len; mp1 = mp2) {
                if (mp2->b_wptr - mp2->b_rptr > len) {
                        /*
                         * We won't consume the entire last mblk.  Like
                         * above, dup and partition it.
                         */
                        mp1->b_cont = dupb(mp2);
                        mp1 = mp1->b_cont;
                        if (!mp1) {
                                /*
                                 * Trouble.  Rather than go to a lot of
                                 * trouble to clean up, we free the messages.
                                 * This won't be any worse than losing it on
                                 * the wire.
                                 */
                                freemsg(mp0);
                                freemsg(mp2);
                                *mpp = NULL;
                                return (NULL);
                        }
                        mp1->b_wptr = mp1->b_rptr + len;
                        mp2->b_rptr = mp1->b_wptr;
                        /*
                         * after adjustments if mblk not consumed is now
                         * unaligned, try to align it. If this fails free
                         * all messages and let upper layer recover.
                         */
                        if (!OK_32PTR(mp2->b_rptr)) {
                                if (!pullupmsg(mp2, -1)) {
                                        freemsg(mp0);
                                        freemsg(mp2);
                                        *mpp = NULL;
                                        return (NULL);
                                }
                        }
                        *mpp = mp2;
                        return (mp0);
                }
                /* Decrement len by the amount we just got. */
                len -= mp2->b_wptr - mp2->b_rptr;
        }
        /*
         * len should be reduced to zero now.  If not our caller has
         * screwed up.
         */
        if (len) {
                /* Shouldn't happen! */
                freemsg(mp0);
                *mpp = NULL;
                return (NULL);
        }
        /*
         * We consumed up to exactly the end of an mblk.  Detach the part
         * we are returning from the rest of the chain.
         */
        mp1->b_cont = NULL;
        *mpp = mp2;
        return (mp0);
}

/* The ill stream is being unplumbed. Called from ip_close */
int
ip_modclose(ill_t *ill)
{
        boolean_t success;
        ipsq_t  *ipsq;
        ipif_t  *ipif;
        queue_t *q = ill->ill_rq;
        ip_stack_t      *ipst = ill->ill_ipst;
        int     i;
        arl_ill_common_t *ai = ill->ill_common;

        /*
         * The punlink prior to this may have initiated a capability
         * negotiation. But ipsq_enter will block until that finishes or
         * times out.
         */
        success = ipsq_enter(ill, B_FALSE, NEW_OP);

        /*
         * Open/close/push/pop is guaranteed to be single threaded
         * per stream by STREAMS. FS guarantees that all references
         * from top are gone before close is called. So there can't
         * be another close thread that has set CONDEMNED on this ill.
         * and cause ipsq_enter to return failure.
         */
        ASSERT(success);
        ipsq = ill->ill_phyint->phyint_ipsq;

        /*
         * Mark it condemned. No new reference will be made to this ill.
         * Lookup functions will return an error. Threads that try to
         * increment the refcnt must check for ILL_CAN_LOOKUP. This ensures
         * that the refcnt will drop down to zero.
         */
        mutex_enter(&ill->ill_lock);
        ill->ill_state_flags |= ILL_CONDEMNED;
        for (ipif = ill->ill_ipif; ipif != NULL;
            ipif = ipif->ipif_next) {
                ipif->ipif_state_flags |= IPIF_CONDEMNED;
        }
        /*
         * Wake up anybody waiting to enter the ipsq. ipsq_enter
         * returns  error if ILL_CONDEMNED is set
         */
        cv_broadcast(&ill->ill_cv);
        mutex_exit(&ill->ill_lock);

        /*
         * Send all the deferred DLPI messages downstream which came in
         * during the small window right before ipsq_enter(). We do this
         * without waiting for the ACKs because all the ACKs for M_PROTO
         * messages are ignored in ip_rput() when ILL_CONDEMNED is set.
         */
        ill_dlpi_send_deferred(ill);

        /*
         * Shut down fragmentation reassembly.
         * ill_frag_timer won't start a timer again.
         * Now cancel any existing timer
         */
        (void) untimeout(ill->ill_frag_timer_id);
        (void) ill_frag_timeout(ill, 0);

        /*
         * Call ill_delete to bring down the ipifs, ilms and ill on
         * this ill. Then wait for the refcnts to drop to zero.
         * ill_is_freeable checks whether the ill is really quiescent.
         * Then make sure that threads that are waiting to enter the
         * ipsq have seen the error returned by ipsq_enter and have
         * gone away. Then we call ill_delete_tail which does the
         * DL_UNBIND_REQ with the driver and then qprocsoff.
         */
        ill_delete(ill);
        mutex_enter(&ill->ill_lock);
        while (!ill_is_freeable(ill))
                cv_wait(&ill->ill_cv, &ill->ill_lock);

        while (ill->ill_waiters)
                cv_wait(&ill->ill_cv, &ill->ill_lock);

        mutex_exit(&ill->ill_lock);

        /*
         * ill_delete_tail drops reference on ill_ipst, but we need to keep
         * it held until the end of the function since the cleanup
         * below needs to be able to use the ip_stack_t.
         */
        netstack_hold(ipst->ips_netstack);

        /* qprocsoff is done via ill_delete_tail */
        ill_delete_tail(ill);
        /*
         * synchronously wait for arp stream to unbind. After this, we
         * cannot get any data packets up from the driver.
         */
        arp_unbind_complete(ill);
        ASSERT(ill->ill_ipst == NULL);

        /*
         * Walk through all conns and qenable those that have queued data.
         * Close synchronization needs this to
         * be done to ensure that all upper layers blocked
         * due to flow control to the closing device
         * get unblocked.
         */
        ip1dbg(("ip_wsrv: walking\n"));
        for (i = 0; i < TX_FANOUT_SIZE; i++) {
                conn_walk_drain(ipst, &ipst->ips_idl_tx_list[i]);
        }

        /*
         * ai can be null if this is an IPv6 ill, or if the IPv4
         * stream is being torn down before ARP was plumbed (e.g.,
         * /sbin/ifconfig plumbing a stream twice, and encountering
         * an error
         */
        if (ai != NULL) {
                ASSERT(!ill->ill_isv6);
                mutex_enter(&ai->ai_lock);
                ai->ai_ill = NULL;
                if (ai->ai_arl == NULL) {
                        mutex_destroy(&ai->ai_lock);
                        kmem_free(ai, sizeof (*ai));
                } else {
                        cv_signal(&ai->ai_ill_unplumb_done);
                        mutex_exit(&ai->ai_lock);
                }
        }

        mutex_enter(&ipst->ips_ip_mi_lock);
        mi_close_unlink(&ipst->ips_ip_g_head, (IDP)ill);
        mutex_exit(&ipst->ips_ip_mi_lock);

        /*
         * credp could be null if the open didn't succeed and ip_modopen
         * itself calls ip_close.
         */
        if (ill->ill_credp != NULL)
                crfree(ill->ill_credp);

        mutex_destroy(&ill->ill_saved_ire_lock);
        mutex_destroy(&ill->ill_lock);
        rw_destroy(&ill->ill_mcast_lock);
        mutex_destroy(&ill->ill_mcast_serializer);
        list_destroy(&ill->ill_nce);

        /*
         * Now we are done with the module close pieces that
         * need the netstack_t.
         */
        netstack_rele(ipst->ips_netstack);

        mi_close_free((IDP)ill);
        q->q_ptr = WR(q)->q_ptr = NULL;

        ipsq_exit(ipsq);

        return (0);
}

/*
 * This is called as part of close() for IP, UDP, ICMP, and RTS
 * in order to quiesce the conn.
 */
void
ip_quiesce_conn(conn_t *connp)
{
        boolean_t       drain_cleanup_reqd = B_FALSE;
        boolean_t       conn_ioctl_cleanup_reqd = B_FALSE;
        boolean_t       ilg_cleanup_reqd = B_FALSE;
        ip_stack_t      *ipst;

        ASSERT(!IPCL_IS_TCP(connp));
        ipst = connp->conn_netstack->netstack_ip;

        /*
         * Mark the conn as closing, and this conn must not be
         * inserted in future into any list. Eg. conn_drain_insert(),
         * won't insert this conn into the conn_drain_list.
         *
         * conn_idl, and conn_ilg cannot get set henceforth.
         */
        mutex_enter(&connp->conn_lock);
        ASSERT(!(connp->conn_state_flags & CONN_QUIESCED));
        connp->conn_state_flags |= CONN_CLOSING;
        if (connp->conn_idl != NULL)
                drain_cleanup_reqd = B_TRUE;
        if (connp->conn_oper_pending_ill != NULL)
                conn_ioctl_cleanup_reqd = B_TRUE;
        if (connp->conn_dhcpinit_ill != NULL) {
                ASSERT(connp->conn_dhcpinit_ill->ill_dhcpinit != 0);
                atomic_dec_32(&connp->conn_dhcpinit_ill->ill_dhcpinit);
                ill_set_inputfn(connp->conn_dhcpinit_ill);
                connp->conn_dhcpinit_ill = NULL;
        }
        if (connp->conn_ilg != NULL)
                ilg_cleanup_reqd = B_TRUE;
        mutex_exit(&connp->conn_lock);

        if (conn_ioctl_cleanup_reqd)
                conn_ioctl_cleanup(connp);

        /*
         * Remove this conn from any fanout list it is on.
         * and then wait for any threads currently operating
         * on this endpoint to finish
         */
        ipcl_hash_remove(connp);

        /*
         * Remove this conn from the drain list, and do any other cleanup that
         * may be required.  (TCP conns are never flow controlled, and
         * conn_idl will be NULL.)
         */
        if (drain_cleanup_reqd && connp->conn_idl != NULL) {
                idl_t *idl = connp->conn_idl;

                mutex_enter(&idl->idl_lock);
                conn_drain(connp, B_TRUE);
                mutex_exit(&idl->idl_lock);
        }

        if (connp == ipst->ips_ip_g_mrouter)
                (void) ip_mrouter_done(ipst);

        if (ilg_cleanup_reqd)
                ilg_delete_all(connp);

        /*
         * Now conn refcnt can increase only thru CONN_INC_REF_LOCKED.
         * callers from write side can't be there now because close
         * is in progress. The only other caller is ipcl_walk
         * which checks for the condemned flag.
         */
        mutex_enter(&connp->conn_lock);
        connp->conn_state_flags |= CONN_CONDEMNED;
        while (connp->conn_ref != 1)
                cv_wait(&connp->conn_cv, &connp->conn_lock);
        connp->conn_state_flags |= CONN_QUIESCED;
        mutex_exit(&connp->conn_lock);
}

/* ARGSUSED */
int
ip_close(queue_t *q, int flags, cred_t *credp __unused)
{
        conn_t          *connp;

        /*
         * Call the appropriate delete routine depending on whether this is
         * a module or device.
         */
        if (WR(q)->q_next != NULL) {
                /* This is a module close */
                return (ip_modclose((ill_t *)q->q_ptr));
        }

        connp = q->q_ptr;
        ip_quiesce_conn(connp);

        qprocsoff(q);

        /*
         * Now we are truly single threaded on this stream, and can
         * delete the things hanging off the connp, and finally the connp.
         * We removed this connp from the fanout list, it cannot be
         * accessed thru the fanouts, and we already waited for the
         * conn_ref to drop to 0. We are already in close, so
         * there cannot be any other thread from the top. qprocsoff
         * has completed, and service has completed or won't run in
         * future.
         */
        ASSERT(connp->conn_ref == 1);

        inet_minor_free(connp->conn_minor_arena, connp->conn_dev);

        connp->conn_ref--;
        ipcl_conn_destroy(connp);

        q->q_ptr = WR(q)->q_ptr = NULL;
        return (0);
}

/*
 * Wapper around putnext() so that ip_rts_request can merely use
 * conn_recv.
 */
/*ARGSUSED2*/
static void
ip_conn_input(void *arg1, mblk_t *mp, void *arg2, ip_recv_attr_t *ira)
{
        conn_t *connp = (conn_t *)arg1;

        putnext(connp->conn_rq, mp);
}

/* Dummy in case ICMP error delivery is attempted to a /dev/ip instance */
/* ARGSUSED */
static void
ip_conn_input_icmp(void *arg1, mblk_t *mp, void *arg2, ip_recv_attr_t *ira)
{
        freemsg(mp);
}

/*
 * Called when the module is about to be unloaded
 */
void
ip_ddi_destroy(void)
{
        /* This needs to be called before destroying any transports. */
        mutex_enter(&cpu_lock);
        unregister_cpu_setup_func(ip_tp_cpu_update, NULL);
        mutex_exit(&cpu_lock);

        icmp_ddi_g_destroy();
        rts_ddi_g_destroy();
        udp_ddi_g_destroy();
        sctp_ddi_g_destroy();
        tcp_ddi_g_destroy();
        ilb_ddi_g_destroy();
        dce_g_destroy();
        ipsec_policy_g_destroy();
        ipcl_g_destroy();
        ip_net_g_destroy();
        ip_ire_g_fini();
        inet_minor_destroy(ip_minor_arena_sa);
#if defined(_LP64)
        inet_minor_destroy(ip_minor_arena_la);
#endif

#ifdef DEBUG
        list_destroy(&ip_thread_list);
        rw_destroy(&ip_thread_rwlock);
        tsd_destroy(&ip_thread_data);
#endif

        netstack_unregister(NS_IP);
}

/*
 * First step in cleanup.
 */
/* ARGSUSED */
static void
ip_stack_shutdown(netstackid_t stackid, void *arg)
{
        ip_stack_t *ipst = (ip_stack_t *)arg;
        kt_did_t ktid;

#ifdef NS_DEBUG
        printf("ip_stack_shutdown(%p, stack %d)\n", (void *)ipst, stackid);
#endif

        /*
         * Perform cleanup for special interfaces (loopback and IPMP).
         */
        ip_interface_cleanup(ipst);

        /*
         * The *_hook_shutdown()s start the process of notifying any
         * consumers that things are going away.... nothing is destroyed.
         */
        ipv4_hook_shutdown(ipst);
        ipv6_hook_shutdown(ipst);
        arp_hook_shutdown(ipst);

        mutex_enter(&ipst->ips_capab_taskq_lock);
        ktid = ipst->ips_capab_taskq_thread->t_did;
        ipst->ips_capab_taskq_quit = B_TRUE;
        cv_signal(&ipst->ips_capab_taskq_cv);
        mutex_exit(&ipst->ips_capab_taskq_lock);

        /*
         * In rare occurrences, particularly on virtual hardware where CPUs can
         * be de-scheduled, the thread that we just signaled will not run until
         * after we have gotten through parts of ip_stack_fini. If that happens
         * then we'll try to grab the ips_capab_taskq_lock as part of returning
         * from cv_wait which no longer exists.
         */
        thread_join(ktid);
}

/*
 * Free the IP stack instance.
 */
static void
ip_stack_fini(netstackid_t stackid, void *arg)
{
        ip_stack_t *ipst = (ip_stack_t *)arg;
        int ret;

#ifdef NS_DEBUG
        printf("ip_stack_fini(%p, stack %d)\n", (void *)ipst, stackid);
#endif
        /*
         * At this point, all of the notifications that the events and
         * protocols are going away have been run, meaning that we can
         * now set about starting to clean things up.
         */
        ipobs_fini(ipst);
        ipv4_hook_destroy(ipst);
        ipv6_hook_destroy(ipst);
        arp_hook_destroy(ipst);
        ip_net_destroy(ipst);

        ipmp_destroy(ipst);

        ip_kstat_fini(stackid, ipst->ips_ip_mibkp);
        ipst->ips_ip_mibkp = NULL;
        icmp_kstat_fini(stackid, ipst->ips_icmp_mibkp);
        ipst->ips_icmp_mibkp = NULL;
        ip_kstat2_fini(stackid, ipst->ips_ip_kstat);
        ipst->ips_ip_kstat = NULL;
        bzero(&ipst->ips_ip_statistics, sizeof (ipst->ips_ip_statistics));
        ip6_kstat_fini(stackid, ipst->ips_ip6_kstat);
        ipst->ips_ip6_kstat = NULL;
        bzero(&ipst->ips_ip6_statistics, sizeof (ipst->ips_ip6_statistics));

        kmem_free(ipst->ips_propinfo_tbl,
            ip_propinfo_count * sizeof (mod_prop_info_t));
        ipst->ips_propinfo_tbl = NULL;

        dce_stack_destroy(ipst);
        ip_mrouter_stack_destroy(ipst);

        /*
         * Quiesce all of our timers. Note we set the quiesce flags before we
         * call untimeout. The slowtimers may actually kick off another instance
         * of the non-slow timers.
         */
        mutex_enter(&ipst->ips_igmp_timer_lock);
        ipst->ips_igmp_timer_quiesce = B_TRUE;
        mutex_exit(&ipst->ips_igmp_timer_lock);

        mutex_enter(&ipst->ips_mld_timer_lock);
        ipst->ips_mld_timer_quiesce = B_TRUE;
        mutex_exit(&ipst->ips_mld_timer_lock);

        mutex_enter(&ipst->ips_igmp_slowtimeout_lock);
        ipst->ips_igmp_slowtimeout_quiesce = B_TRUE;
        mutex_exit(&ipst->ips_igmp_slowtimeout_lock);

        mutex_enter(&ipst->ips_mld_slowtimeout_lock);
        ipst->ips_mld_slowtimeout_quiesce = B_TRUE;
        mutex_exit(&ipst->ips_mld_slowtimeout_lock);

        ret = untimeout(ipst->ips_igmp_timeout_id);
        if (ret == -1) {
                ASSERT(ipst->ips_igmp_timeout_id == 0);
        } else {
                ASSERT(ipst->ips_igmp_timeout_id != 0);
                ipst->ips_igmp_timeout_id = 0;
        }
        ret = untimeout(ipst->ips_igmp_slowtimeout_id);
        if (ret == -1) {
                ASSERT(ipst->ips_igmp_slowtimeout_id == 0);
        } else {
                ASSERT(ipst->ips_igmp_slowtimeout_id != 0);
                ipst->ips_igmp_slowtimeout_id = 0;
        }
        ret = untimeout(ipst->ips_mld_timeout_id);
        if (ret == -1) {
                ASSERT(ipst->ips_mld_timeout_id == 0);
        } else {
                ASSERT(ipst->ips_mld_timeout_id != 0);
                ipst->ips_mld_timeout_id = 0;
        }
        ret = untimeout(ipst->ips_mld_slowtimeout_id);
        if (ret == -1) {
                ASSERT(ipst->ips_mld_slowtimeout_id == 0);
        } else {
                ASSERT(ipst->ips_mld_slowtimeout_id != 0);
                ipst->ips_mld_slowtimeout_id = 0;
        }

        ip_ire_fini(ipst);
        ip6_asp_free(ipst);
        conn_drain_fini(ipst);
        ipcl_destroy(ipst);

        mutex_destroy(&ipst->ips_ndp4->ndp_g_lock);
        mutex_destroy(&ipst->ips_ndp6->ndp_g_lock);
        kmem_free(ipst->ips_ndp4, sizeof (ndp_g_t));
        ipst->ips_ndp4 = NULL;
        kmem_free(ipst->ips_ndp6, sizeof (ndp_g_t));
        ipst->ips_ndp6 = NULL;

        if (ipst->ips_loopback_ksp != NULL) {
                kstat_delete_netstack(ipst->ips_loopback_ksp, stackid);
                ipst->ips_loopback_ksp = NULL;
        }

        mutex_destroy(&ipst->ips_capab_taskq_lock);
        cv_destroy(&ipst->ips_capab_taskq_cv);

        rw_destroy(&ipst->ips_srcid_lock);

        mutex_destroy(&ipst->ips_ip_mi_lock);
        rw_destroy(&ipst->ips_ill_g_usesrc_lock);

        mutex_destroy(&ipst->ips_igmp_timer_lock);
        mutex_destroy(&ipst->ips_mld_timer_lock);
        mutex_destroy(&ipst->ips_igmp_slowtimeout_lock);
        mutex_destroy(&ipst->ips_mld_slowtimeout_lock);
        mutex_destroy(&ipst->ips_ip_addr_avail_lock);
        rw_destroy(&ipst->ips_ill_g_lock);

        kmem_free(ipst->ips_phyint_g_list, sizeof (phyint_list_t));
        ipst->ips_phyint_g_list = NULL;
        kmem_free(ipst->ips_ill_g_heads, sizeof (ill_g_head_t) * MAX_G_HEADS);
        ipst->ips_ill_g_heads = NULL;

        ldi_ident_release(ipst->ips_ldi_ident);
        kmem_free(ipst, sizeof (*ipst));
}

/*
 * This function is called from the TSD destructor, and is used to debug
 * reference count issues in IP. See block comment in <inet/ip_if.h> for
 * details.
 */
static void
ip_thread_exit(void *phash)
{
        th_hash_t *thh = phash;

        rw_enter(&ip_thread_rwlock, RW_WRITER);
        list_remove(&ip_thread_list, thh);
        rw_exit(&ip_thread_rwlock);
        mod_hash_destroy_hash(thh->thh_hash);
        kmem_free(thh, sizeof (*thh));
}

/*
 * Called when the IP kernel module is loaded into the kernel
 */
void
ip_ddi_init(void)
{
        ip_squeue_flag = ip_squeue_switch(ip_squeue_enter);

        /*
         * For IP and TCP the minor numbers should start from 2 since we have 4
         * initial devices: ip, ip6, tcp, tcp6.
         */
        /*
         * If this is a 64-bit kernel, then create two separate arenas -
         * one for TLIs in the range of INET_MIN_DEV+2 through 2^^18-1, and the
         * other for socket apps in the range 2^^18 through 2^^32-1.
         */
        ip_minor_arena_la = NULL;
        ip_minor_arena_sa = NULL;
#if defined(_LP64)
        if ((ip_minor_arena_sa = inet_minor_create("ip_minor_arena_sa",
            INET_MIN_DEV + 2, MAXMIN32, KM_SLEEP)) == NULL) {
                cmn_err(CE_PANIC,
                    "ip_ddi_init: ip_minor_arena_sa creation failed\n");
        }
        if ((ip_minor_arena_la = inet_minor_create("ip_minor_arena_la",
            MAXMIN32 + 1, MAXMIN64, KM_SLEEP)) == NULL) {
                cmn_err(CE_PANIC,
                    "ip_ddi_init: ip_minor_arena_la creation failed\n");
        }
#else
        if ((ip_minor_arena_sa = inet_minor_create("ip_minor_arena_sa",
            INET_MIN_DEV + 2, MAXMIN, KM_SLEEP)) == NULL) {
                cmn_err(CE_PANIC,
                    "ip_ddi_init: ip_minor_arena_sa creation failed\n");
        }
#endif
        ip_poll_normal_ticks = MSEC_TO_TICK_ROUNDUP(ip_poll_normal_ms);

        ipcl_g_init();
        ip_ire_g_init();
        ip_net_g_init();

#ifdef DEBUG
        tsd_create(&ip_thread_data, ip_thread_exit);
        rw_init(&ip_thread_rwlock, NULL, RW_DEFAULT, NULL);
        list_create(&ip_thread_list, sizeof (th_hash_t),
            offsetof(th_hash_t, thh_link));
#endif
        ipsec_policy_g_init();
        tcp_ddi_g_init();
        sctp_ddi_g_init();
        dce_g_init();

        /*
         * We want to be informed each time a stack is created or
         * destroyed in the kernel, so we can maintain the
         * set of udp_stack_t's.
         */
        netstack_register(NS_IP, ip_stack_init, ip_stack_shutdown,
            ip_stack_fini);

        udp_ddi_g_init();
        rts_ddi_g_init();
        icmp_ddi_g_init();
        ilb_ddi_g_init();

        /* This needs to be called after all transports are initialized. */
        mutex_enter(&cpu_lock);
        register_cpu_setup_func(ip_tp_cpu_update, NULL);
        mutex_exit(&cpu_lock);
}

/*
 * Initialize the IP stack instance.
 */
static void *
ip_stack_init(netstackid_t stackid, netstack_t *ns)
{
        ip_stack_t      *ipst;
        size_t          arrsz;
        major_t         major;

#ifdef NS_DEBUG
        printf("ip_stack_init(stack %d)\n", stackid);
#endif

        ipst = (ip_stack_t *)kmem_zalloc(sizeof (*ipst), KM_SLEEP);
        ipst->ips_netstack = ns;

        ipst->ips_ill_g_heads = kmem_zalloc(sizeof (ill_g_head_t) * MAX_G_HEADS,
            KM_SLEEP);
        ipst->ips_phyint_g_list = kmem_zalloc(sizeof (phyint_list_t),
            KM_SLEEP);
        ipst->ips_ndp4 = kmem_zalloc(sizeof (ndp_g_t), KM_SLEEP);
        ipst->ips_ndp6 = kmem_zalloc(sizeof (ndp_g_t), KM_SLEEP);
        mutex_init(&ipst->ips_ndp4->ndp_g_lock, NULL, MUTEX_DEFAULT, NULL);
        mutex_init(&ipst->ips_ndp6->ndp_g_lock, NULL, MUTEX_DEFAULT, NULL);

        mutex_init(&ipst->ips_igmp_timer_lock, NULL, MUTEX_DEFAULT, NULL);
        ipst->ips_igmp_deferred_next = INFINITY;
        mutex_init(&ipst->ips_mld_timer_lock, NULL, MUTEX_DEFAULT, NULL);
        ipst->ips_mld_deferred_next = INFINITY;
        mutex_init(&ipst->ips_igmp_slowtimeout_lock, NULL, MUTEX_DEFAULT, NULL);
        mutex_init(&ipst->ips_mld_slowtimeout_lock, NULL, MUTEX_DEFAULT, NULL);
        mutex_init(&ipst->ips_ip_mi_lock, NULL, MUTEX_DEFAULT, NULL);
        mutex_init(&ipst->ips_ip_addr_avail_lock, NULL, MUTEX_DEFAULT, NULL);
        rw_init(&ipst->ips_ill_g_lock, NULL, RW_DEFAULT, NULL);
        rw_init(&ipst->ips_ill_g_usesrc_lock, NULL, RW_DEFAULT, NULL);

        ipcl_init(ipst);
        ip_ire_init(ipst);
        ip6_asp_init(ipst);
        ipif_init(ipst);
        conn_drain_init(ipst);
        ip_mrouter_stack_init(ipst);
        dce_stack_init(ipst);

        ipst->ips_ill_index = 1;

        ipst->ips_saved_ip_forwarding = -1;
        ipst->ips_reg_vif_num = ALL_VIFS;       /* Index to Register vif */

        arrsz = ip_propinfo_count * sizeof (mod_prop_info_t);
        ipst->ips_propinfo_tbl = (mod_prop_info_t *)kmem_alloc(arrsz, KM_SLEEP);
        bcopy(ip_propinfo_tbl, ipst->ips_propinfo_tbl, arrsz);

        ipst->ips_ip_mibkp = ip_kstat_init(stackid, ipst);
        ipst->ips_icmp_mibkp = icmp_kstat_init(stackid);
        ipst->ips_ip_kstat = ip_kstat2_init(stackid, &ipst->ips_ip_statistics);
        ipst->ips_ip6_kstat =
            ip6_kstat_init(stackid, &ipst->ips_ip6_statistics);

        ipst->ips_ip_src_id = 1;
        rw_init(&ipst->ips_srcid_lock, NULL, RW_DEFAULT, NULL);

        ipst->ips_src_generation = SRC_GENERATION_INITIAL;

        ip_net_init(ipst, ns);
        ipv4_hook_init(ipst);
        ipv6_hook_init(ipst);
        arp_hook_init(ipst);
        ipmp_init(ipst);
        ipobs_init(ipst);

        /*
         * Create the taskq dispatcher thread and initialize related stuff.
         */
        mutex_init(&ipst->ips_capab_taskq_lock, NULL, MUTEX_DEFAULT, NULL);
        cv_init(&ipst->ips_capab_taskq_cv, NULL, CV_DEFAULT, NULL);
        ipst->ips_capab_taskq_thread = thread_create(NULL, 0,
            ill_taskq_dispatch, ipst, 0, &p0, TS_RUN, minclsyspri);

        major = mod_name_to_major(INET_NAME);
        (void) ldi_ident_from_major(major, &ipst->ips_ldi_ident);
        return (ipst);
}

/*
 * Allocate and initialize a DLPI template of the specified length.  (May be
 * called as writer.)
 */
mblk_t *
ip_dlpi_alloc(size_t len, t_uscalar_t prim)
{
        mblk_t  *mp;

        mp = allocb(len, BPRI_MED);
        if (!mp)
                return (NULL);

        /*
         * DLPIv2 says that DL_INFO_REQ and DL_TOKEN_REQ (the latter
         * of which we don't seem to use) are sent with M_PCPROTO, and
         * that other DLPI are M_PROTO.
         */
        if (prim == DL_INFO_REQ) {
                mp->b_datap->db_type = M_PCPROTO;
        } else {
                mp->b_datap->db_type = M_PROTO;
        }

        mp->b_wptr = mp->b_rptr + len;
        bzero(mp->b_rptr, len);
        ((dl_unitdata_req_t *)mp->b_rptr)->dl_primitive = prim;
        return (mp);
}

/*
 * Allocate and initialize a DLPI notification.  (May be called as writer.)
 */
mblk_t *
ip_dlnotify_alloc(uint_t notification, uint_t data)
{
        dl_notify_ind_t *notifyp;
        mblk_t          *mp;

        if ((mp = ip_dlpi_alloc(DL_NOTIFY_IND_SIZE, DL_NOTIFY_IND)) == NULL)
                return (NULL);

        notifyp = (dl_notify_ind_t *)mp->b_rptr;
        notifyp->dl_notification = notification;
        notifyp->dl_data = data;
        return (mp);
}

mblk_t *
ip_dlnotify_alloc2(uint_t notification, uint_t data1, uint_t data2)
{
        dl_notify_ind_t *notifyp;
        mblk_t          *mp;

        if ((mp = ip_dlpi_alloc(DL_NOTIFY_IND_SIZE, DL_NOTIFY_IND)) == NULL)
                return (NULL);

        notifyp = (dl_notify_ind_t *)mp->b_rptr;
        notifyp->dl_notification = notification;
        notifyp->dl_data1 = data1;
        notifyp->dl_data2 = data2;
        return (mp);
}

/*
 * Debug formatting routine.  Returns a character string representation of the
 * addr in buf, of the form xxx.xxx.xxx.xxx.  This routine takes the address
 * in the form of a ipaddr_t and calls ip_dot_saddr with a pointer.
 *
 * Once the ndd table-printing interfaces are removed, this can be changed to
 * standard dotted-decimal form.
 */
char *
ip_dot_addr(ipaddr_t addr, char *buf)
{
        uint8_t *ap = (uint8_t *)&addr;

        (void) mi_sprintf(buf, "%03d.%03d.%03d.%03d",
            ap[0] & 0xFF, ap[1] & 0xFF, ap[2] & 0xFF, ap[3] & 0xFF);
        return (buf);
}

/*
 * Write the given MAC address as a printable string in the usual colon-
 * separated format.
 */
const char *
mac_colon_addr(const uint8_t *addr, size_t alen, char *buf, size_t buflen)
{
        char *bp;

        if (alen == 0 || buflen < 4)
                return ("?");
        bp = buf;
        for (;;) {
                /*
                 * If there are more MAC address bytes available, but we won't
                 * have any room to print them, then add "..." to the string
                 * instead.  See below for the 'magic number' explanation.
                 */
                if ((alen == 2 && buflen < 6) || (alen > 2 && buflen < 7)) {
                        (void) strcpy(bp, "...");
                        break;
                }
                (void) sprintf(bp, "%02x", *addr++);
                bp += 2;
                if (--alen == 0)
                        break;
                *bp++ = ':';
                buflen -= 3;
                /*
                 * At this point, based on the first 'if' statement above,
                 * either alen == 1 and buflen >= 3, or alen > 1 and
                 * buflen >= 4.  The first case leaves room for the final "xx"
                 * number and trailing NUL byte.  The second leaves room for at
                 * least "...".  Thus the apparently 'magic' numbers chosen for
                 * that statement.
                 */
        }
        return (buf);
}

/*
 * Called when it is conceptually a ULP that would sent the packet
 * e.g., port unreachable and protocol unreachable. Check that the packet
 * would have passed the IPsec global policy before sending the error.
 *
 * Send an ICMP error after patching up the packet appropriately.
 * Uses ip_drop_input and bumps the appropriate MIB.
 */
void
ip_fanout_send_icmp_v4(mblk_t *mp, uint_t icmp_type, uint_t icmp_code,
    ip_recv_attr_t *ira)
{
        ipha_t          *ipha;
        boolean_t       secure;
        ill_t           *ill = ira->ira_ill;
        ip_stack_t      *ipst = ill->ill_ipst;
        netstack_t      *ns = ipst->ips_netstack;
        ipsec_stack_t   *ipss = ns->netstack_ipsec;

        secure = ira->ira_flags & IRAF_IPSEC_SECURE;

        /*
         * We are generating an icmp error for some inbound packet.
         * Called from all ip_fanout_(udp, tcp, proto) functions.
         * Before we generate an error, check with global policy
         * to see whether this is allowed to enter the system. As
         * there is no "conn", we are checking with global policy.
         */
        ipha = (ipha_t *)mp->b_rptr;
        if (secure || ipss->ipsec_inbound_v4_policy_present) {
                mp = ipsec_check_global_policy(mp, NULL, ipha, NULL, ira, ns);
                if (mp == NULL)
                        return;
        }

        /* We never send errors for protocols that we do implement */
        if (ira->ira_protocol == IPPROTO_ICMP ||
            ira->ira_protocol == IPPROTO_IGMP) {
                BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                ip_drop_input("ip_fanout_send_icmp_v4", mp, ill);
                freemsg(mp);
                return;
        }
        /*
         * Have to correct checksum since
         * the packet might have been
         * fragmented and the reassembly code in ip_rput
         * does not restore the IP checksum.
         */
        ipha->ipha_hdr_checksum = 0;
        ipha->ipha_hdr_checksum = ip_csum_hdr(ipha);

        switch (icmp_type) {
        case ICMP_DEST_UNREACHABLE:
                switch (icmp_code) {
                case ICMP_PROTOCOL_UNREACHABLE:
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInUnknownProtos);
                        ip_drop_input("ipIfStatsInUnknownProtos", mp, ill);
                        break;
                case ICMP_PORT_UNREACHABLE:
                        BUMP_MIB(ill->ill_ip_mib, udpIfStatsNoPorts);
                        ip_drop_input("ipIfStatsNoPorts", mp, ill);
                        break;
                }

                icmp_unreachable(mp, icmp_code, ira);
                break;
        default:
#ifdef DEBUG
                panic("ip_fanout_send_icmp_v4: wrong type");
                /*NOTREACHED*/
#else
                freemsg(mp);
                break;
#endif
        }
}

/*
 * Used to send an ICMP error message when a packet is received for
 * a protocol that is not supported. The mblk passed as argument
 * is consumed by this function.
 */
void
ip_proto_not_sup(mblk_t *mp, ip_recv_attr_t *ira)
{
        ipha_t          *ipha;

        ipha = (ipha_t *)mp->b_rptr;
        if (ira->ira_flags & IRAF_IS_IPV4) {
                ASSERT(IPH_HDR_VERSION(ipha) == IP_VERSION);
                ip_fanout_send_icmp_v4(mp, ICMP_DEST_UNREACHABLE,
                    ICMP_PROTOCOL_UNREACHABLE, ira);
        } else {
                ASSERT(IPH_HDR_VERSION(ipha) == IPV6_VERSION);
                ip_fanout_send_icmp_v6(mp, ICMP6_PARAM_PROB,
                    ICMP6_PARAMPROB_NEXTHEADER, ira);
        }
}

/*
 * Deliver a rawip packet to the given conn, possibly applying ipsec policy.
 * Handles IPv4 and IPv6.
 * We are responsible for disposing of mp, such as by freemsg() or putnext()
 * Caller is responsible for dropping references to the conn.
 */
void
ip_fanout_proto_conn(conn_t *connp, mblk_t *mp, ipha_t *ipha, ip6_t *ip6h,
    ip_recv_attr_t *ira)
{
        ill_t           *ill = ira->ira_ill;
        ip_stack_t      *ipst = ill->ill_ipst;
        ipsec_stack_t   *ipss = ipst->ips_netstack->netstack_ipsec;
        boolean_t       secure;
        uint_t          protocol = ira->ira_protocol;
        iaflags_t       iraflags = ira->ira_flags;
        queue_t         *rq;

        secure = iraflags & IRAF_IPSEC_SECURE;

        rq = connp->conn_rq;
        if (IPCL_IS_NONSTR(connp) ? connp->conn_flow_cntrld : !canputnext(rq)) {
                switch (protocol) {
                case IPPROTO_ICMPV6:
                        BUMP_MIB(ill->ill_icmp6_mib, ipv6IfIcmpInOverflows);
                        break;
                case IPPROTO_ICMP:
                        BUMP_MIB(&ipst->ips_icmp_mib, icmpInOverflows);
                        break;
                default:
                        BUMP_MIB(ill->ill_ip_mib, rawipIfStatsInOverflows);
                        break;
                }
                freemsg(mp);
                return;
        }

        ASSERT(!(IPCL_IS_IPTUN(connp)));

        if (((iraflags & IRAF_IS_IPV4) ?
            CONN_INBOUND_POLICY_PRESENT(connp, ipss) :
            CONN_INBOUND_POLICY_PRESENT_V6(connp, ipss)) ||
            secure) {
                mp = ipsec_check_inbound_policy(mp, connp, ipha,
                    ip6h, ira);
                if (mp == NULL) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                        /* Note that mp is NULL */
                        ip_drop_input("ipIfStatsInDiscards", mp, ill);
                        return;
                }
        }

        if (iraflags & IRAF_ICMP_ERROR) {
                (connp->conn_recvicmp)(connp, mp, NULL, ira);
        } else {
                ill_t *rill = ira->ira_rill;

                BUMP_MIB(ill->ill_ip_mib, ipIfStatsHCInDelivers);
                ira->ira_ill = ira->ira_rill = NULL;
                /* Send it upstream */
                (connp->conn_recv)(connp, mp, NULL, ira);
                ira->ira_ill = ill;
                ira->ira_rill = rill;
        }
}

/*
 * Handle protocols with which IP is less intimate.  There
 * can be more than one stream bound to a particular
 * protocol.  When this is the case, normally each one gets a copy
 * of any incoming packets.
 *
 * IPsec NOTE :
 *
 * Don't allow a secure packet going up a non-secure connection.
 * We don't allow this because
 *
 * 1) Reply might go out in clear which will be dropped at
 *    the sending side.
 * 2) If the reply goes out in clear it will give the
 *    adversary enough information for getting the key in
 *    most of the cases.
 *
 * Moreover getting a secure packet when we expect clear
 * implies that SA's were added without checking for
 * policy on both ends. This should not happen once ISAKMP
 * is used to negotiate SAs as SAs will be added only after
 * verifying the policy.
 *
 * Zones notes:
 * Earlier in ip_input on a system with multiple shared-IP zones we
 * duplicate the multicast and broadcast packets and send them up
 * with each explicit zoneid that exists on that ill.
 * This means that here we can match the zoneid with SO_ALLZONES being special.
 */
void
ip_fanout_proto_v4(mblk_t *mp, ipha_t *ipha, ip_recv_attr_t *ira)
{
        mblk_t          *mp1;
        ipaddr_t        laddr;
        conn_t          *connp, *first_connp, *next_connp;
        connf_t         *connfp;
        ill_t           *ill = ira->ira_ill;
        ip_stack_t      *ipst = ill->ill_ipst;

        laddr = ipha->ipha_dst;

        connfp = &ipst->ips_ipcl_proto_fanout_v4[ira->ira_protocol];
        mutex_enter(&connfp->connf_lock);
        connp = connfp->connf_head;

        if (connp == NULL) {
                /*
                 * No one bound to these addresses.  Is
                 * there a client that wants all
                 * unclaimed datagrams?
                 */
                mutex_exit(&connfp->connf_lock);
                ip_fanout_send_icmp_v4(mp, ICMP_DEST_UNREACHABLE,
                    ICMP_PROTOCOL_UNREACHABLE, ira);
                return;
        }

        ASSERT(IPCL_IS_NONSTR(connp) || connp->conn_rq != NULL);

        CONN_INC_REF(connp);
        first_connp = connp;
        connp = connp->conn_next;

        for (;;) {
                while (connp != NULL) {
                        /* Note: IPCL_PROTO_MATCH includes conn_wantpacket */
                        if (IPCL_PROTO_MATCH(connp, ira, ipha))
                                break;
                        connp = connp->conn_next;
                }

                if (connp == NULL) {
                        /* No more interested clients */
                        connp = first_connp;
                        break;
                }
                if (((mp1 = dupmsg(mp)) == NULL) &&
                    ((mp1 = copymsg(mp)) == NULL)) {
                        /* Memory allocation failed */
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                        ip_drop_input("ipIfStatsInDiscards", mp, ill);
                        connp = first_connp;
                        break;
                }

                CONN_INC_REF(connp);
                mutex_exit(&connfp->connf_lock);

                ip_fanout_proto_conn(connp, mp1, (ipha_t *)mp1->b_rptr, NULL,
                    ira);

                mutex_enter(&connfp->connf_lock);
                /* Follow the next pointer before releasing the conn. */
                next_connp = connp->conn_next;
                CONN_DEC_REF(connp);
                connp = next_connp;
        }

        /* Last one.  Send it upstream. */
        mutex_exit(&connfp->connf_lock);

        ip_fanout_proto_conn(connp, mp, ipha, NULL, ira);

        CONN_DEC_REF(connp);
}

/*
 * If we have a IPsec NAT-Traversal packet, strip the zero-SPI or
 * pass it along to ESP if the SPI is non-zero.  Returns the mblk if the mblk
 * is not consumed.
 *
 * One of three things can happen, all of which affect the passed-in mblk:
 *
 * 1.) The packet is stock UDP and gets its zero-SPI stripped.  Return mblk..
 *
 * 2.) The packet is ESP-in-UDP, gets transformed into an equivalent
 *     ESP packet, and is passed along to ESP for consumption.  Return NULL.
 *
 * 3.) The packet is an ESP-in-UDP Keepalive.  Drop it and return NULL.
 */
mblk_t *
zero_spi_check(mblk_t *mp, ip_recv_attr_t *ira)
{
        int shift, plen, iph_len;
        ipha_t *ipha;
        udpha_t *udpha;
        uint32_t *spi;
        uint32_t esp_ports;
        uint8_t *orptr;
        ip_stack_t      *ipst = ira->ira_ill->ill_ipst;
        ipsec_stack_t   *ipss = ipst->ips_netstack->netstack_ipsec;

        ipha = (ipha_t *)mp->b_rptr;
        iph_len = ira->ira_ip_hdr_length;
        plen = ira->ira_pktlen;

        if (plen - iph_len - sizeof (udpha_t) < sizeof (uint32_t)) {
                /*
                 * Most likely a keepalive for the benefit of an intervening
                 * NAT.  These aren't for us, per se, so drop it.
                 *
                 * RFC 3947/8 doesn't say for sure what to do for 2-3
                 * byte packets (keepalives are 1-byte), but we'll drop them
                 * also.
                 */
                ip_drop_packet(mp, B_TRUE, ira->ira_ill,
                    DROPPER(ipss, ipds_esp_nat_t_ka), &ipss->ipsec_dropper);
                return (NULL);
        }

        if (MBLKL(mp) < iph_len + sizeof (udpha_t) + sizeof (*spi)) {
                /* might as well pull it all up - it might be ESP. */
                if (!pullupmsg(mp, -1)) {
                        ip_drop_packet(mp, B_TRUE, ira->ira_ill,
                            DROPPER(ipss, ipds_esp_nomem),
                            &ipss->ipsec_dropper);
                        return (NULL);
                }

                ipha = (ipha_t *)mp->b_rptr;
        }
        spi = (uint32_t *)(mp->b_rptr + iph_len + sizeof (udpha_t));
        if (*spi == 0) {
                /* UDP packet - remove 0-spi. */
                shift = sizeof (uint32_t);
        } else {
                /* ESP-in-UDP packet - reduce to ESP. */
                ipha->ipha_protocol = IPPROTO_ESP;
                shift = sizeof (udpha_t);
        }

        /* Fix IP header */
        ira->ira_pktlen = (plen - shift);
        ipha->ipha_length = htons(ira->ira_pktlen);
        ipha->ipha_hdr_checksum = 0;

        orptr = mp->b_rptr;
        mp->b_rptr += shift;

        udpha = (udpha_t *)(orptr + iph_len);
        if (*spi == 0) {
                ASSERT((uint8_t *)ipha == orptr);
                udpha->uha_length = htons(plen - shift - iph_len);
                iph_len += sizeof (udpha_t);    /* For the call to ovbcopy(). */
                esp_ports = 0;
        } else {
                esp_ports = *((uint32_t *)udpha);
                ASSERT(esp_ports != 0);
        }
        ovbcopy(orptr, orptr + shift, iph_len);
        if (esp_ports != 0) /* Punt up for ESP processing. */ {
                ipha = (ipha_t *)(orptr + shift);

                ira->ira_flags |= IRAF_ESP_UDP_PORTS;
                ira->ira_esp_udp_ports = esp_ports;
                ip_fanout_v4(mp, ipha, ira);
                return (NULL);
        }
        return (mp);
}

/*
 * Deliver a udp packet to the given conn, possibly applying ipsec policy.
 * Handles IPv4 and IPv6.
 * We are responsible for disposing of mp, such as by freemsg() or putnext()
 * Caller is responsible for dropping references to the conn.
 */
void
ip_fanout_udp_conn(conn_t *connp, mblk_t *mp, ipha_t *ipha, ip6_t *ip6h,
    ip_recv_attr_t *ira)
{
        ill_t           *ill = ira->ira_ill;
        ip_stack_t      *ipst = ill->ill_ipst;
        ipsec_stack_t   *ipss = ipst->ips_netstack->netstack_ipsec;
        boolean_t       secure;
        iaflags_t       iraflags = ira->ira_flags;

        secure = iraflags & IRAF_IPSEC_SECURE;

        if (IPCL_IS_NONSTR(connp) ? connp->conn_flow_cntrld :
            !canputnext(connp->conn_rq)) {
                BUMP_MIB(ill->ill_ip_mib, udpIfStatsInOverflows);
                freemsg(mp);
                return;
        }

        if (((iraflags & IRAF_IS_IPV4) ?
            CONN_INBOUND_POLICY_PRESENT(connp, ipss) :
            CONN_INBOUND_POLICY_PRESENT_V6(connp, ipss)) ||
            secure) {
                mp = ipsec_check_inbound_policy(mp, connp, ipha,
                    ip6h, ira);
                if (mp == NULL) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                        /* Note that mp is NULL */
                        ip_drop_input("ipIfStatsInDiscards", mp, ill);
                        return;
                }
        }

        /*
         * Since this code is not used for UDP unicast we don't need a NAT_T
         * check. Only ip_fanout_v4 has that check.
         */
        if (ira->ira_flags & IRAF_ICMP_ERROR) {
                (connp->conn_recvicmp)(connp, mp, NULL, ira);
        } else {
                ill_t *rill = ira->ira_rill;

                BUMP_MIB(ill->ill_ip_mib, ipIfStatsHCInDelivers);
                ira->ira_ill = ira->ira_rill = NULL;
                /* Send it upstream */
                (connp->conn_recv)(connp, mp, NULL, ira);
                ira->ira_ill = ill;
                ira->ira_rill = rill;
        }
}

/*
 * Fanout for UDP packets that are multicast or broadcast, and ICMP errors.
 * (Unicast fanout is handled in ip_input_v4.)
 *
 * If SO_REUSEADDR is set all multicast and broadcast packets
 * will be delivered to all conns bound to the same port.
 *
 * If there is at least one matching AF_INET receiver, then we will
 * ignore any AF_INET6 receivers.
 * In the special case where an AF_INET socket binds to 0.0.0.0/<port> and an
 * AF_INET6 socket binds to ::/<port>, only the AF_INET socket receives the IPv4
 * packets.
 *
 * Zones notes:
 * Earlier in ip_input on a system with multiple shared-IP zones we
 * duplicate the multicast and broadcast packets and send them up
 * with each explicit zoneid that exists on that ill.
 * This means that here we can match the zoneid with SO_ALLZONES being special.
 */
void
ip_fanout_udp_multi_v4(mblk_t *mp, ipha_t *ipha, uint16_t lport, uint16_t fport,
    ip_recv_attr_t *ira)
{
        ipaddr_t        laddr;
        in6_addr_t      v6faddr;
        conn_t          *connp;
        connf_t         *connfp;
        ipaddr_t        faddr;
        ill_t           *ill = ira->ira_ill;
        ip_stack_t      *ipst = ill->ill_ipst;

        ASSERT(ira->ira_flags & (IRAF_MULTIBROADCAST|IRAF_ICMP_ERROR));

        laddr = ipha->ipha_dst;
        faddr = ipha->ipha_src;

        connfp = &ipst->ips_ipcl_udp_fanout[IPCL_UDP_HASH(lport, ipst)];
        mutex_enter(&connfp->connf_lock);
        connp = connfp->connf_head;

        /*
         * If SO_REUSEADDR has been set on the first we send the
         * packet to all clients that have joined the group and
         * match the port.
         */
        while (connp != NULL) {
                if ((IPCL_UDP_MATCH(connp, lport, laddr, fport, faddr)) &&
                    conn_wantpacket(connp, ira, ipha))
                        break;
                connp = connp->conn_next;
        }

        if (connp == NULL)
                goto notfound;

        CONN_INC_REF(connp);

        if (connp->conn_reuseaddr) {
                conn_t          *first_connp = connp;
                conn_t          *next_connp;
                mblk_t          *mp1;

                connp = connp->conn_next;
                for (;;) {
                        while (connp != NULL) {
                                if (IPCL_UDP_MATCH(connp, lport, laddr,
                                    fport, faddr) &&
                                    conn_wantpacket(connp, ira, ipha))
                                        break;
                                connp = connp->conn_next;
                        }
                        if (connp == NULL) {
                                /* No more interested clients */
                                connp = first_connp;
                                break;
                        }
                        if (((mp1 = dupmsg(mp)) == NULL) &&
                            ((mp1 = copymsg(mp)) == NULL)) {
                                /* Memory allocation failed */
                                BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                                ip_drop_input("ipIfStatsInDiscards", mp, ill);
                                connp = first_connp;
                                break;
                        }
                        CONN_INC_REF(connp);
                        mutex_exit(&connfp->connf_lock);

                        IP_STAT(ipst, ip_udp_fanmb);
                        ip_fanout_udp_conn(connp, mp1, (ipha_t *)mp1->b_rptr,
                            NULL, ira);
                        mutex_enter(&connfp->connf_lock);
                        /* Follow the next pointer before releasing the conn */
                        next_connp = connp->conn_next;
                        CONN_DEC_REF(connp);
                        connp = next_connp;
                }
        }

        /* Last one.  Send it upstream. */
        mutex_exit(&connfp->connf_lock);
        IP_STAT(ipst, ip_udp_fanmb);
        ip_fanout_udp_conn(connp, mp, ipha, NULL, ira);
        CONN_DEC_REF(connp);
        return;

notfound:
        mutex_exit(&connfp->connf_lock);
        /*
         * IPv6 endpoints bound to multicast IPv4-mapped addresses
         * have already been matched above, since they live in the IPv4
         * fanout tables. This implies we only need to
         * check for IPv6 in6addr_any endpoints here.
         * Thus we compare using ipv6_all_zeros instead of the destination
         * address, except for the multicast group membership lookup which
         * uses the IPv4 destination.
         */
        IN6_IPADDR_TO_V4MAPPED(ipha->ipha_src, &v6faddr);
        connfp = &ipst->ips_ipcl_udp_fanout[IPCL_UDP_HASH(lport, ipst)];
        mutex_enter(&connfp->connf_lock);
        connp = connfp->connf_head;
        /*
         * IPv4 multicast packet being delivered to an AF_INET6
         * in6addr_any endpoint.
         * Need to check conn_wantpacket(). Note that we use conn_wantpacket()
         * and not conn_wantpacket_v6() since any multicast membership is
         * for an IPv4-mapped multicast address.
         */
        while (connp != NULL) {
                if (IPCL_UDP_MATCH_V6(connp, lport, ipv6_all_zeros,
                    fport, v6faddr) &&
                    conn_wantpacket(connp, ira, ipha))
                        break;
                connp = connp->conn_next;
        }

        if (connp == NULL) {
                /*
                 * No one bound to this port.  Is
                 * there a client that wants all
                 * unclaimed datagrams?
                 */
                mutex_exit(&connfp->connf_lock);

                if (ipst->ips_ipcl_proto_fanout_v4[IPPROTO_UDP].connf_head !=
                    NULL) {
                        ASSERT(ira->ira_protocol == IPPROTO_UDP);
                        ip_fanout_proto_v4(mp, ipha, ira);
                } else {
                        /*
                         * We used to attempt to send an icmp error here, but
                         * since this is known to be a multicast packet
                         * and we don't send icmp errors in response to
                         * multicast, just drop the packet and give up sooner.
                         */
                        BUMP_MIB(ill->ill_ip_mib, udpIfStatsNoPorts);
                        freemsg(mp);
                }
                return;
        }
        CONN_INC_REF(connp);
        ASSERT(IPCL_IS_NONSTR(connp) || connp->conn_rq != NULL);

        /*
         * If SO_REUSEADDR has been set on the first we send the
         * packet to all clients that have joined the group and
         * match the port.
         */
        if (connp->conn_reuseaddr) {
                conn_t          *first_connp = connp;
                conn_t          *next_connp;
                mblk_t          *mp1;

                connp = connp->conn_next;
                for (;;) {
                        while (connp != NULL) {
                                if (IPCL_UDP_MATCH_V6(connp, lport,
                                    ipv6_all_zeros, fport, v6faddr) &&
                                    conn_wantpacket(connp, ira, ipha))
                                        break;
                                connp = connp->conn_next;
                        }
                        if (connp == NULL) {
                                /* No more interested clients */
                                connp = first_connp;
                                break;
                        }
                        if (((mp1 = dupmsg(mp)) == NULL) &&
                            ((mp1 = copymsg(mp)) == NULL)) {
                                /* Memory allocation failed */
                                BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                                ip_drop_input("ipIfStatsInDiscards", mp, ill);
                                connp = first_connp;
                                break;
                        }
                        CONN_INC_REF(connp);
                        mutex_exit(&connfp->connf_lock);

                        IP_STAT(ipst, ip_udp_fanmb);
                        ip_fanout_udp_conn(connp, mp1, (ipha_t *)mp1->b_rptr,
                            NULL, ira);
                        mutex_enter(&connfp->connf_lock);
                        /* Follow the next pointer before releasing the conn */
                        next_connp = connp->conn_next;
                        CONN_DEC_REF(connp);
                        connp = next_connp;
                }
        }

        /* Last one.  Send it upstream. */
        mutex_exit(&connfp->connf_lock);
        IP_STAT(ipst, ip_udp_fanmb);
        ip_fanout_udp_conn(connp, mp, ipha, NULL, ira);
        CONN_DEC_REF(connp);
}

/*
 * Split an incoming packet's IPv4 options into options.
 * If 'allocate' is set it does memory allocation for the ip_pkt_t, including
 * clearing out any leftover options.
 * Otherwise it just makes ipp point into the packet.
 *
 * Returns zero if ok; ENOMEM if the buffer couldn't be allocated.
 */
int
ip_find_hdr_v4(ipha_t *ipha, ip_pkt_t *ipp, boolean_t allocate)
{
        uchar_t         *opt;
        uint32_t        totallen;
        uint32_t        optval;
        uint32_t        optlen;

        ipp->ipp_fields |= IPPF_HOPLIMIT | IPPF_TCLASS | IPPF_ADDR;
        ipp->ipp_hoplimit = ipha->ipha_ttl;
        ipp->ipp_type_of_service = ipha->ipha_type_of_service;
        IN6_IPADDR_TO_V4MAPPED(ipha->ipha_dst, &ipp->ipp_addr);

        /*
         * Get length (in 4 byte octets) of IP header options.
         */
        totallen = ipha->ipha_version_and_hdr_length -
            (uint8_t)((IP_VERSION << 4) + IP_SIMPLE_HDR_LENGTH_IN_WORDS);

        if (totallen == 0) {
                if (!allocate)
                        return (0);

                /* Clear out anything from a previous packet */
                if (ipp->ipp_fields & IPPF_IPV4_OPTIONS) {
                        kmem_free(ipp->ipp_ipv4_options,
                            ipp->ipp_ipv4_options_len);
                        ipp->ipp_ipv4_options = NULL;
                        ipp->ipp_ipv4_options_len = 0;
                        ipp->ipp_fields &= ~IPPF_IPV4_OPTIONS;
                }
                return (0);
        }

        totallen <<= 2;
        opt = (uchar_t *)&ipha[1];

copyall:
        if (!allocate) {
                if (totallen != 0) {
                        ipp->ipp_ipv4_options = opt;
                        ipp->ipp_ipv4_options_len = totallen;
                        ipp->ipp_fields |= IPPF_IPV4_OPTIONS;
                }
                return (0);
        }
        /* Just copy all of options */
        if (ipp->ipp_fields & IPPF_IPV4_OPTIONS) {
                if (totallen == ipp->ipp_ipv4_options_len) {
                        bcopy(opt, ipp->ipp_ipv4_options, totallen);
                        return (0);
                }
                kmem_free(ipp->ipp_ipv4_options,
                    ipp->ipp_ipv4_options_len);
                ipp->ipp_ipv4_options = NULL;
                ipp->ipp_ipv4_options_len = 0;
                ipp->ipp_fields &= ~IPPF_IPV4_OPTIONS;
        }
        if (totallen == 0)
                return (0);

        ipp->ipp_ipv4_options = kmem_alloc(totallen, KM_NOSLEEP);
        if (ipp->ipp_ipv4_options == NULL)
                return (ENOMEM);
        ipp->ipp_ipv4_options_len = totallen;
        ipp->ipp_fields |= IPPF_IPV4_OPTIONS;
        bcopy(opt, ipp->ipp_ipv4_options, totallen);
        return (0);

        totallen = ipha->ipha_version_and_hdr_length -
            (uint8_t)((IP_VERSION << 4) + IP_SIMPLE_HDR_LENGTH_IN_WORDS);
        totallen <<= 2;
        opt = (uchar_t *)&ipha[1];
        goto copyall;
}

/*
 * Efficient versions of lookup for an IRE when we only
 * match the address.
 * For RTF_REJECT or BLACKHOLE we return IRE_NOROUTE.
 * Does not handle multicast addresses.
 */
uint_t
ip_type_v4(ipaddr_t addr, ip_stack_t *ipst)
{
        ire_t *ire;
        uint_t result;

        ire = ire_ftable_lookup_simple_v4(addr, 0, ipst, NULL);
        ASSERT(ire != NULL);
        if (ire->ire_flags & (RTF_REJECT|RTF_BLACKHOLE))
                result = IRE_NOROUTE;
        else
                result = ire->ire_type;
        ire_refrele(ire);
        return (result);
}

/*
 * Efficient versions of lookup for an IRE when we only
 * match the address.
 * For RTF_REJECT or BLACKHOLE we return IRE_NOROUTE.
 * Does not handle multicast addresses.
 */
uint_t
ip_type_v6(const in6_addr_t *addr, ip_stack_t *ipst)
{
        ire_t *ire;
        uint_t result;

        ire = ire_ftable_lookup_simple_v6(addr, 0, ipst, NULL);
        ASSERT(ire != NULL);
        if (ire->ire_flags & (RTF_REJECT|RTF_BLACKHOLE))
                result = IRE_NOROUTE;
        else
                result = ire->ire_type;
        ire_refrele(ire);
        return (result);
}

/*
 * Nobody should be sending
 * packets up this stream
 */
static int
ip_lrput(queue_t *q, mblk_t *mp)
{
        switch (mp->b_datap->db_type) {
        case M_FLUSH:
                /* Turn around */
                if (*mp->b_rptr & FLUSHW) {
                        *mp->b_rptr &= ~FLUSHR;
                        qreply(q, mp);
                        return (0);
                }
                break;
        }
        freemsg(mp);
        return (0);
}

/* Nobody should be sending packets down this stream */
/* ARGSUSED */
int
ip_lwput(queue_t *q, mblk_t *mp)
{
        freemsg(mp);
        return (0);
}

/*
 * Move the first hop in any source route to ipha_dst and remove that part of
 * the source route.  Called by other protocols.  Errors in option formatting
 * are ignored - will be handled by ip_output_options. Return the final
 * destination (either ipha_dst or the last entry in a source route.)
 */
ipaddr_t
ip_massage_options(ipha_t *ipha, netstack_t *ns)
{
        ipoptp_t        opts;
        uchar_t         *opt;
        uint8_t         optval;
        uint8_t         optlen;
        ipaddr_t        dst;
        int             i;
        ip_stack_t      *ipst = ns->netstack_ip;

        ip2dbg(("ip_massage_options\n"));
        dst = ipha->ipha_dst;
        for (optval = ipoptp_first(&opts, ipha);
            optval != IPOPT_EOL;
            optval = ipoptp_next(&opts)) {
                opt = opts.ipoptp_cur;
                switch (optval) {
                        uint8_t off;
                case IPOPT_SSRR:
                case IPOPT_LSRR:
                        if ((opts.ipoptp_flags & IPOPTP_ERROR) != 0) {
                                ip1dbg(("ip_massage_options: bad src route\n"));
                                break;
                        }
                        optlen = opts.ipoptp_len;
                        off = opt[IPOPT_OFFSET];
                        off--;
                redo_srr:
                        if (optlen < IP_ADDR_LEN ||
                            off > optlen - IP_ADDR_LEN) {
                                /* End of source route */
                                ip1dbg(("ip_massage_options: end of SR\n"));
                                break;
                        }
                        bcopy((char *)opt + off, &dst, IP_ADDR_LEN);
                        ip1dbg(("ip_massage_options: next hop 0x%x\n",
                            ntohl(dst)));
                        /*
                         * Check if our address is present more than
                         * once as consecutive hops in source route.
                         * XXX verify per-interface ip_forwarding
                         * for source route?
                         */
                        if (ip_type_v4(dst, ipst) == IRE_LOCAL) {
                                off += IP_ADDR_LEN;
                                goto redo_srr;
                        }
                        if (dst == htonl(INADDR_LOOPBACK)) {
                                ip1dbg(("ip_massage_options: loopback addr in "
                                    "source route!\n"));
                                break;
                        }
                        /*
                         * Update ipha_dst to be the first hop and remove the
                         * first hop from the source route (by overwriting
                         * part of the option with NOP options).
                         */
                        ipha->ipha_dst = dst;
                        /* Put the last entry in dst */
                        off = ((optlen - IP_ADDR_LEN - 3) & ~(IP_ADDR_LEN-1)) +
                            3;
                        bcopy(&opt[off], &dst, IP_ADDR_LEN);

                        ip1dbg(("ip_massage_options: last hop 0x%x\n",
                            ntohl(dst)));
                        /* Move down and overwrite */
                        opt[IP_ADDR_LEN] = opt[0];
                        opt[IP_ADDR_LEN+1] = opt[IPOPT_OLEN] - IP_ADDR_LEN;
                        opt[IP_ADDR_LEN+2] = opt[IPOPT_OFFSET];
                        for (i = 0; i < IP_ADDR_LEN; i++)
                                opt[i] = IPOPT_NOP;
                        break;
                }
        }
        return (dst);
}

/*
 * Return the network mask
 * associated with the specified address.
 */
ipaddr_t
ip_net_mask(ipaddr_t addr)
{
        uchar_t *up = (uchar_t *)&addr;
        ipaddr_t mask = 0;
        uchar_t *maskp = (uchar_t *)&mask;

#if defined(__i386) || defined(__amd64)
#define TOTALLY_BRAIN_DAMAGED_C_COMPILER
#endif
#ifdef  TOTALLY_BRAIN_DAMAGED_C_COMPILER
        maskp[0] = maskp[1] = maskp[2] = maskp[3] = 0;
#endif
        if (CLASSD(addr)) {
                maskp[0] = 0xF0;
                return (mask);
        }

        /* We assume Class E default netmask to be 32 */
        if (CLASSE(addr))
                return (0xffffffffU);

        if (addr == 0)
                return (0);
        maskp[0] = 0xFF;
        if ((up[0] & 0x80) == 0)
                return (mask);

        maskp[1] = 0xFF;
        if ((up[0] & 0xC0) == 0x80)
                return (mask);

        maskp[2] = 0xFF;
        if ((up[0] & 0xE0) == 0xC0)
                return (mask);

        /* Otherwise return no mask */
        return ((ipaddr_t)0);
}

/* Name/Value Table Lookup Routine */
char *
ip_nv_lookup(nv_t *nv, int value)
{
        if (!nv)
                return (NULL);
        for (; nv->nv_name; nv++) {
                if (nv->nv_value == value)
                        return (nv->nv_name);
        }
        return ("unknown");
}

static int
ip_wait_for_info_ack(ill_t *ill)
{
        int err;

        mutex_enter(&ill->ill_lock);
        while (ill->ill_state_flags & ILL_LL_SUBNET_PENDING) {
                /*
                 * Return value of 0 indicates a pending signal.
                 */
                err = cv_wait_sig(&ill->ill_cv, &ill->ill_lock);
                if (err == 0) {
                        mutex_exit(&ill->ill_lock);
                        return (EINTR);
                }
        }
        mutex_exit(&ill->ill_lock);
        /*
         * ip_rput_other could have set an error  in ill_error on
         * receipt of M_ERROR.
         */
        return (ill->ill_error);
}

/*
 * This is a module open, i.e. this is a control stream for access
 * to a DLPI device.  We allocate an ill_t as the instance data in
 * this case.
 */
static int
ip_modopen(queue_t *q, dev_t *devp, int flag, int sflag, cred_t *credp)
{
        ill_t   *ill;
        int     err;
        zoneid_t zoneid;
        netstack_t *ns;
        ip_stack_t *ipst;

        /*
         * Prevent unprivileged processes from pushing IP so that
         * they can't send raw IP.
         */
        if (secpolicy_net_rawaccess(credp) != 0)
                return (EPERM);

        ns = netstack_find_by_cred(credp);
        ASSERT(ns != NULL);
        ipst = ns->netstack_ip;
        ASSERT(ipst != NULL);

        /*
         * For exclusive stacks we set the zoneid to zero
         * to make IP operate as if in the global zone.
         */
        if (ipst->ips_netstack->netstack_stackid != GLOBAL_NETSTACKID)
                zoneid = GLOBAL_ZONEID;
        else
                zoneid = crgetzoneid(credp);

        ill = (ill_t *)mi_open_alloc_sleep(sizeof (ill_t));
        q->q_ptr = WR(q)->q_ptr = ill;
        ill->ill_ipst = ipst;
        ill->ill_zoneid = zoneid;

        /*
         * ill_init initializes the ill fields and then sends down
         * down a DL_INFO_REQ after calling qprocson.
         */
        err = ill_init(q, ill);

        if (err != 0) {
                mi_free(ill);
                netstack_rele(ipst->ips_netstack);
                q->q_ptr = NULL;
                WR(q)->q_ptr = NULL;
                return (err);
        }

        /*
         * Wait for the DL_INFO_ACK if a DL_INFO_REQ was sent.
         *
         * ill_init initializes the ipsq marking this thread as
         * writer
         */
        ipsq_exit(ill->ill_phyint->phyint_ipsq);
        err = ip_wait_for_info_ack(ill);
        if (err == 0)
                ill->ill_credp = credp;
        else
                goto fail;

        crhold(credp);

        mutex_enter(&ipst->ips_ip_mi_lock);
        err = mi_open_link(&ipst->ips_ip_g_head, (IDP)q->q_ptr, devp, flag,
            sflag, credp);
        mutex_exit(&ipst->ips_ip_mi_lock);
fail:
        if (err) {
                (void) ip_close(q, 0, credp);
                return (err);
        }
        return (0);
}

/* For /dev/ip aka AF_INET open */
int
ip_openv4(queue_t *q, dev_t *devp, int flag, int sflag, cred_t *credp)
{
        return (ip_open(q, devp, flag, sflag, credp, B_FALSE));
}

/* For /dev/ip6 aka AF_INET6 open */
int
ip_openv6(queue_t *q, dev_t *devp, int flag, int sflag, cred_t *credp)
{
        return (ip_open(q, devp, flag, sflag, credp, B_TRUE));
}

/* IP open routine. */
int
ip_open(queue_t *q, dev_t *devp, int flag, int sflag, cred_t *credp,
    boolean_t isv6)
{
        conn_t          *connp;
        major_t         maj;
        zoneid_t        zoneid;
        netstack_t      *ns;
        ip_stack_t      *ipst;

        /* Allow reopen. */
        if (q->q_ptr != NULL)
                return (0);

        if (sflag & MODOPEN) {
                /* This is a module open */
                return (ip_modopen(q, devp, flag, sflag, credp));
        }

        if ((flag & ~(FKLYR)) == IP_HELPER_STR) {
                /*
                 * Non streams based socket looking for a stream
                 * to access IP
                 */
                return (ip_helper_stream_setup(q, devp, flag, sflag,
                    credp, isv6));
        }

        ns = netstack_find_by_cred(credp);
        ASSERT(ns != NULL);
        ipst = ns->netstack_ip;
        ASSERT(ipst != NULL);

        /*
         * For exclusive stacks we set the zoneid to zero
         * to make IP operate as if in the global zone.
         */
        if (ipst->ips_netstack->netstack_stackid != GLOBAL_NETSTACKID)
                zoneid = GLOBAL_ZONEID;
        else
                zoneid = crgetzoneid(credp);

        /*
         * We are opening as a device. This is an IP client stream, and we
         * allocate an conn_t as the instance data.
         */
        connp = ipcl_conn_create(IPCL_IPCCONN, KM_SLEEP, ipst->ips_netstack);

        /*
         * ipcl_conn_create did a netstack_hold. Undo the hold that was
         * done by netstack_find_by_cred()
         */
        netstack_rele(ipst->ips_netstack);

        connp->conn_ixa->ixa_flags |= IXAF_MULTICAST_LOOP | IXAF_SET_ULP_CKSUM;
        /* conn_allzones can not be set this early, hence no IPCL_ZONEID */
        connp->conn_ixa->ixa_zoneid = zoneid;
        connp->conn_zoneid = zoneid;

        connp->conn_rq = q;
        q->q_ptr = WR(q)->q_ptr = connp;

        /* Minor tells us which /dev entry was opened */
        if (isv6) {
                connp->conn_family = AF_INET6;
                connp->conn_ipversion = IPV6_VERSION;
                connp->conn_ixa->ixa_flags &= ~IXAF_IS_IPV4;
                connp->conn_ixa->ixa_src_preferences = IPV6_PREFER_SRC_DEFAULT;
        } else {
                connp->conn_family = AF_INET;
                connp->conn_ipversion = IPV4_VERSION;
                connp->conn_ixa->ixa_flags |= IXAF_IS_IPV4;
        }

        if ((ip_minor_arena_la != NULL) && (flag & SO_SOCKSTR) &&
            ((connp->conn_dev = inet_minor_alloc(ip_minor_arena_la)) != 0)) {
                connp->conn_minor_arena = ip_minor_arena_la;
        } else {
                /*
                 * Either minor numbers in the large arena were exhausted
                 * or a non socket application is doing the open.
                 * Try to allocate from the small arena.
                 */
                if ((connp->conn_dev =
                    inet_minor_alloc(ip_minor_arena_sa)) == 0) {
                        /* CONN_DEC_REF takes care of netstack_rele() */
                        q->q_ptr = WR(q)->q_ptr = NULL;
                        CONN_DEC_REF(connp);
                        return (EBUSY);
                }
                connp->conn_minor_arena = ip_minor_arena_sa;
        }

        maj = getemajor(*devp);
        *devp = makedevice(maj, (minor_t)connp->conn_dev);

        /*
         * connp->conn_cred is crfree()ed in ipcl_conn_destroy()
         */
        connp->conn_cred = credp;
        connp->conn_cpid = curproc->p_pid;
        /* Cache things in ixa without an extra refhold */
        ASSERT(!(connp->conn_ixa->ixa_free_flags & IXA_FREE_CRED));
        connp->conn_ixa->ixa_cred = connp->conn_cred;
        connp->conn_ixa->ixa_cpid = connp->conn_cpid;

        /*
         * Handle IP_IOC_RTS_REQUEST and other ioctls which use conn_recv
         */
        connp->conn_recv = ip_conn_input;
        connp->conn_recvicmp = ip_conn_input_icmp;

        crhold(connp->conn_cred);

        connp->conn_zone_is_global = (crgetzoneid(credp) == GLOBAL_ZONEID);

        connp->conn_rq = q;
        connp->conn_wq = WR(q);

        /* Non-zero default values */
        connp->conn_ixa->ixa_flags |= IXAF_MULTICAST_LOOP;

        /*
         * Make the conn globally visible to walkers
         */
        ASSERT(connp->conn_ref == 1);
        mutex_enter(&connp->conn_lock);
        connp->conn_state_flags &= ~CONN_INCIPIENT;
        mutex_exit(&connp->conn_lock);

        qprocson(q);

        return (0);
}

/*
 * Set IPsec policy from an ipsec_req_t. If the req is not "zero" and valid,
 * all of them are copied to the conn_t. If the req is "zero", the policy is
 * zeroed out. A "zero" policy has zero ipsr_{ah,req,self_encap}_req
 * fields.
 * We keep only the latest setting of the policy and thus policy setting
 * is not incremental/cumulative.
 *
 * Requests to set policies with multiple alternative actions will
 * go through a different API.
 */
int
ipsec_set_req(cred_t *cr, conn_t *connp, ipsec_req_t *req)
{
        uint_t ah_req = 0;
        uint_t esp_req = 0;
        uint_t se_req = 0;
        ipsec_act_t *actp = NULL;
        uint_t nact;
        ipsec_policy_head_t *ph;
        boolean_t is_pol_reset, is_pol_inserted = B_FALSE;
        int error = 0;
        netstack_t      *ns = connp->conn_netstack;
        ip_stack_t      *ipst = ns->netstack_ip;
        ipsec_stack_t   *ipss = ns->netstack_ipsec;

#define REQ_MASK (IPSEC_PREF_REQUIRED|IPSEC_PREF_NEVER)

        /*
         * The IP_SEC_OPT option does not allow variable length parameters,
         * hence a request cannot be NULL.
         */
        if (req == NULL)
                return (EINVAL);

        ah_req = req->ipsr_ah_req;
        esp_req = req->ipsr_esp_req;
        se_req = req->ipsr_self_encap_req;

        /* Don't allow setting self-encap without one or more of AH/ESP. */
        if (se_req != 0 && esp_req == 0 && ah_req == 0)
                return (EINVAL);

        /*
         * Are we dealing with a request to reset the policy (i.e.
         * zero requests).
         */
        is_pol_reset = ((ah_req & REQ_MASK) == 0 &&
            (esp_req & REQ_MASK) == 0 &&
            (se_req & REQ_MASK) == 0);

        if (!is_pol_reset) {
                /*
                 * If we couldn't load IPsec, fail with "protocol
                 * not supported".
                 * IPsec may not have been loaded for a request with zero
                 * policies, so we don't fail in this case.
                 */
                mutex_enter(&ipss->ipsec_loader_lock);
                if (ipss->ipsec_loader_state != IPSEC_LOADER_SUCCEEDED) {
                        mutex_exit(&ipss->ipsec_loader_lock);
                        return (EPROTONOSUPPORT);
                }
                mutex_exit(&ipss->ipsec_loader_lock);

                /*
                 * Test for valid requests. Invalid algorithms
                 * need to be tested by IPsec code because new
                 * algorithms can be added dynamically.
                 */
                if ((ah_req & ~(REQ_MASK|IPSEC_PREF_UNIQUE)) != 0 ||
                    (esp_req & ~(REQ_MASK|IPSEC_PREF_UNIQUE)) != 0 ||
                    (se_req & ~(REQ_MASK|IPSEC_PREF_UNIQUE)) != 0) {
                        return (EINVAL);
                }

                /*
                 * Only privileged users can issue these
                 * requests.
                 */
                if (((ah_req & IPSEC_PREF_NEVER) ||
                    (esp_req & IPSEC_PREF_NEVER) ||
                    (se_req & IPSEC_PREF_NEVER)) &&
                    secpolicy_ip_config(cr, B_FALSE) != 0) {
                        return (EPERM);
                }

                /*
                 * The IPSEC_PREF_REQUIRED and IPSEC_PREF_NEVER
                 * are mutually exclusive.
                 */
                if (((ah_req & REQ_MASK) == REQ_MASK) ||
                    ((esp_req & REQ_MASK) == REQ_MASK) ||
                    ((se_req & REQ_MASK) == REQ_MASK)) {
                        /* Both of them are set */
                        return (EINVAL);
                }
        }

        ASSERT(MUTEX_HELD(&connp->conn_lock));

        /*
         * If we have already cached policies in conn_connect(), don't
         * let them change now. We cache policies for connections
         * whose src,dst [addr, port] is known.
         */
        if (connp->conn_policy_cached) {
                return (EINVAL);
        }

        /*
         * We have a zero policies, reset the connection policy if already
         * set. This will cause the connection to inherit the
         * global policy, if any.
         */
        if (is_pol_reset) {
                if (connp->conn_policy != NULL) {
                        IPPH_REFRELE(connp->conn_policy, ipst->ips_netstack);
                        connp->conn_policy = NULL;
                }
                connp->conn_in_enforce_policy = B_FALSE;
                connp->conn_out_enforce_policy = B_FALSE;
                return (0);
        }

        ph = connp->conn_policy = ipsec_polhead_split(connp->conn_policy,
            ipst->ips_netstack);
        if (ph == NULL)
                goto enomem;

        ipsec_actvec_from_req(req, &actp, &nact, ipst->ips_netstack);
        if (actp == NULL)
                goto enomem;

        /*
         * Always insert IPv4 policy entries, since they can also apply to
         * ipv6 sockets being used in ipv4-compat mode.
         */
        if (!ipsec_polhead_insert(ph, actp, nact, IPSEC_AF_V4,
            IPSEC_TYPE_INBOUND, ns))
                goto enomem;
        is_pol_inserted = B_TRUE;
        if (!ipsec_polhead_insert(ph, actp, nact, IPSEC_AF_V4,
            IPSEC_TYPE_OUTBOUND, ns))
                goto enomem;

        /*
         * We're looking at a v6 socket, also insert the v6-specific
         * entries.
         */
        if (connp->conn_family == AF_INET6) {
                if (!ipsec_polhead_insert(ph, actp, nact, IPSEC_AF_V6,
                    IPSEC_TYPE_INBOUND, ns))
                        goto enomem;
                if (!ipsec_polhead_insert(ph, actp, nact, IPSEC_AF_V6,
                    IPSEC_TYPE_OUTBOUND, ns))
                        goto enomem;
        }

        ipsec_actvec_free(actp, nact);

        /*
         * If the requests need security, set enforce_policy.
         * If the requests are IPSEC_PREF_NEVER, one should
         * still set conn_out_enforce_policy so that ip_set_destination
         * marks the ip_xmit_attr_t appropriatly. This is needed so that
         * for connections that we don't cache policy in at connect time,
         * if global policy matches in ip_output_attach_policy, we
         * don't wrongly inherit global policy. Similarly, we need
         * to set conn_in_enforce_policy also so that we don't verify
         * policy wrongly.
         */
        if ((ah_req & REQ_MASK) != 0 ||
            (esp_req & REQ_MASK) != 0 ||
            (se_req & REQ_MASK) != 0) {
                connp->conn_in_enforce_policy = B_TRUE;
                connp->conn_out_enforce_policy = B_TRUE;
        }

        return (error);
#undef REQ_MASK

        /*
         * Common memory-allocation-failure exit path.
         */
enomem:
        if (actp != NULL)
                ipsec_actvec_free(actp, nact);
        if (is_pol_inserted)
                ipsec_polhead_flush(ph, ns);
        return (ENOMEM);
}

/*
 * Set socket options for joining and leaving multicast groups.
 * Common to IPv4 and IPv6; inet6 indicates the type of socket.
 * The caller has already check that the option name is consistent with
 * the address family of the socket.
 */
int
ip_opt_set_multicast_group(conn_t *connp, t_scalar_t name,
    uchar_t *invalp, boolean_t inet6, boolean_t checkonly)
{
        int             *i1 = (int *)invalp;
        int             error = 0;
        ip_stack_t      *ipst = connp->conn_netstack->netstack_ip;
        struct ip_mreq  *v4_mreqp;
        struct ipv6_mreq *v6_mreqp;
        struct group_req *greqp;
        ire_t *ire;
        boolean_t done = B_FALSE;
        ipaddr_t ifaddr;
        in6_addr_t v6group;
        uint_t ifindex;
        boolean_t mcast_opt = B_TRUE;
        mcast_record_t fmode;
        int (*optfn)(conn_t *, boolean_t, const in6_addr_t *,
            ipaddr_t, uint_t, mcast_record_t, const in6_addr_t *);

        switch (name) {
        case IP_ADD_MEMBERSHIP:
        case IPV6_JOIN_GROUP:
                mcast_opt = B_FALSE;
                /* FALLTHROUGH */
        case MCAST_JOIN_GROUP:
                fmode = MODE_IS_EXCLUDE;
                optfn = ip_opt_add_group;
                break;

        case IP_DROP_MEMBERSHIP:
        case IPV6_LEAVE_GROUP:
                mcast_opt = B_FALSE;
                /* FALLTHROUGH */
        case MCAST_LEAVE_GROUP:
                fmode = MODE_IS_INCLUDE;
                optfn = ip_opt_delete_group;
                break;
        default:
                ASSERT(0);
        }

        if (mcast_opt) {
                struct sockaddr_in *sin;
                struct sockaddr_in6 *sin6;

                greqp = (struct group_req *)i1;
                if (greqp->gr_group.ss_family == AF_INET) {
                        sin = (struct sockaddr_in *)&(greqp->gr_group);
                        IN6_INADDR_TO_V4MAPPED(&sin->sin_addr, &v6group);
                } else {
                        if (!inet6)
                                return (EINVAL);        /* Not on INET socket */

                        sin6 = (struct sockaddr_in6 *)&(greqp->gr_group);
                        v6group = sin6->sin6_addr;
                }
                ifaddr = INADDR_ANY;
                ifindex = greqp->gr_interface;
        } else if (inet6) {
                v6_mreqp = (struct ipv6_mreq *)i1;
                v6group = v6_mreqp->ipv6mr_multiaddr;
                ifaddr = INADDR_ANY;
                ifindex = v6_mreqp->ipv6mr_interface;
        } else {
                v4_mreqp = (struct ip_mreq *)i1;
                IN6_INADDR_TO_V4MAPPED(&v4_mreqp->imr_multiaddr, &v6group);
                ifaddr = (ipaddr_t)v4_mreqp->imr_interface.s_addr;
                ifindex = 0;
        }

        /*
         * In the multirouting case, we need to replicate
         * the request on all interfaces that will take part
         * in replication.  We do so because multirouting is
         * reflective, thus we will probably receive multi-
         * casts on those interfaces.
         */
        if (IN6_IS_ADDR_V4MAPPED(&v6group)) {
                ipaddr_t group;

                IN6_V4MAPPED_TO_IPADDR(&v6group, group);

                ire = ire_ftable_lookup_v4(group, IP_HOST_MASK, 0,
                    IRE_HOST | IRE_INTERFACE, NULL, ALL_ZONES,
                    MATCH_IRE_MASK | MATCH_IRE_TYPE, 0, ipst, NULL);
        } else {
                ire = ire_ftable_lookup_v6(&v6group, &ipv6_all_ones, 0,
                    IRE_HOST | IRE_INTERFACE, NULL, ALL_ZONES,
                    MATCH_IRE_MASK | MATCH_IRE_TYPE, 0, ipst, NULL);
        }
        if (ire != NULL)
                ire_refrele(ire);

        if (!done) {
                error = optfn(connp, checkonly, &v6group, ifaddr, ifindex,
                    fmode, &ipv6_all_zeros);
        }
        return (error);
}

/*
 * Set socket options for joining and leaving multicast groups
 * for specific sources.
 * Common to IPv4 and IPv6; inet6 indicates the type of socket.
 * The caller has already check that the option name is consistent with
 * the address family of the socket.
 */
int
ip_opt_set_multicast_sources(conn_t *connp, t_scalar_t name,
    uchar_t *invalp, boolean_t inet6, boolean_t checkonly)
{
        int             *i1 = (int *)invalp;
        ip_stack_t      *ipst = connp->conn_netstack->netstack_ip;
        struct ip_mreq_source *imreqp;
        struct group_source_req *gsreqp;
        in6_addr_t v6group, v6src;
        uint32_t ifindex;
        ipaddr_t ifaddr;
        boolean_t mcast_opt = B_TRUE;
        mcast_record_t fmode;
        ire_t *ire;
        int (*optfn)(conn_t *, boolean_t, const in6_addr_t *,
            ipaddr_t, uint_t, mcast_record_t, const in6_addr_t *);

        switch (name) {
        case IP_BLOCK_SOURCE:
                mcast_opt = B_FALSE;
                /* FALLTHROUGH */
        case MCAST_BLOCK_SOURCE:
                fmode = MODE_IS_EXCLUDE;
                optfn = ip_opt_add_group;
                break;

        case IP_UNBLOCK_SOURCE:
                mcast_opt = B_FALSE;
                /* FALLTHROUGH */
        case MCAST_UNBLOCK_SOURCE:
                fmode = MODE_IS_EXCLUDE;
                optfn = ip_opt_delete_group;
                break;

        case IP_ADD_SOURCE_MEMBERSHIP:
                mcast_opt = B_FALSE;
                /* FALLTHROUGH */
        case MCAST_JOIN_SOURCE_GROUP:
                fmode = MODE_IS_INCLUDE;
                optfn = ip_opt_add_group;
                break;

        case IP_DROP_SOURCE_MEMBERSHIP:
                mcast_opt = B_FALSE;
                /* FALLTHROUGH */
        case MCAST_LEAVE_SOURCE_GROUP:
                fmode = MODE_IS_INCLUDE;
                optfn = ip_opt_delete_group;
                break;
        default:
                ASSERT(0);
        }

        if (mcast_opt) {
                gsreqp = (struct group_source_req *)i1;
                ifindex = gsreqp->gsr_interface;
                if (gsreqp->gsr_group.ss_family == AF_INET) {
                        struct sockaddr_in *s;
                        s = (struct sockaddr_in *)&gsreqp->gsr_group;
                        IN6_INADDR_TO_V4MAPPED(&s->sin_addr, &v6group);
                        s = (struct sockaddr_in *)&gsreqp->gsr_source;
                        IN6_INADDR_TO_V4MAPPED(&s->sin_addr, &v6src);
                } else {
                        struct sockaddr_in6 *s6;

                        if (!inet6)
                                return (EINVAL);        /* Not on INET socket */

                        s6 = (struct sockaddr_in6 *)&gsreqp->gsr_group;
                        v6group = s6->sin6_addr;
                        s6 = (struct sockaddr_in6 *)&gsreqp->gsr_source;
                        v6src = s6->sin6_addr;
                }
                ifaddr = INADDR_ANY;
        } else {
                imreqp = (struct ip_mreq_source *)i1;
                IN6_INADDR_TO_V4MAPPED(&imreqp->imr_multiaddr, &v6group);
                IN6_INADDR_TO_V4MAPPED(&imreqp->imr_sourceaddr, &v6src);
                ifaddr = (ipaddr_t)imreqp->imr_interface.s_addr;
                ifindex = 0;
        }

        /*
         * Handle src being mapped INADDR_ANY by changing it to unspecified.
         */
        if (IN6_IS_ADDR_V4MAPPED_ANY(&v6src))
                v6src = ipv6_all_zeros;

        /*
         * In the multirouting case, we need to replicate
         * the request as noted in the mcast cases above.
         */
        if (IN6_IS_ADDR_V4MAPPED(&v6group)) {
                ipaddr_t group;

                IN6_V4MAPPED_TO_IPADDR(&v6group, group);

                ire = ire_ftable_lookup_v4(group, IP_HOST_MASK, 0,
                    IRE_HOST | IRE_INTERFACE, NULL, ALL_ZONES,
                    MATCH_IRE_MASK | MATCH_IRE_TYPE, 0, ipst, NULL);
        } else {
                ire = ire_ftable_lookup_v6(&v6group, &ipv6_all_ones, 0,
                    IRE_HOST | IRE_INTERFACE, NULL, ALL_ZONES,
                    MATCH_IRE_MASK | MATCH_IRE_TYPE, 0, ipst, NULL);
        }
        if (ire != NULL)
                ire_refrele(ire);
        return (optfn(connp, checkonly, &v6group, ifaddr, ifindex,
            fmode, &v6src));
}

/*
 * Given a destination address and a pointer to where to put the information
 * this routine fills in the mtuinfo.
 * The socket must be connected.
 * For sctp conn_faddr is the primary address.
 */
int
ip_fill_mtuinfo(conn_t *connp, ip_xmit_attr_t *ixa, struct ip6_mtuinfo *mtuinfo)
{
        uint32_t        pmtu = IP_MAXPACKET;
        uint_t          scopeid;

        if (IN6_IS_ADDR_UNSPECIFIED(&connp->conn_faddr_v6))
                return (-1);

        /* In case we never sent or called ip_set_destination_v4/v6 */
        if (ixa->ixa_ire != NULL)
                pmtu = ip_get_pmtu(ixa);

        if (ixa->ixa_flags & IXAF_SCOPEID_SET)
                scopeid = ixa->ixa_scopeid;
        else
                scopeid = 0;

        bzero(mtuinfo, sizeof (*mtuinfo));
        mtuinfo->ip6m_addr.sin6_family = AF_INET6;
        mtuinfo->ip6m_addr.sin6_port = connp->conn_fport;
        mtuinfo->ip6m_addr.sin6_addr = connp->conn_faddr_v6;
        mtuinfo->ip6m_addr.sin6_scope_id = scopeid;
        mtuinfo->ip6m_mtu = pmtu;

        return (sizeof (struct ip6_mtuinfo));
}

/*
 * When the src multihoming is changed from weak to [strong, preferred]
 * ip_ire_rebind_walker is called to walk the list of all ire_t entries
 * and identify routes that were created by user-applications in the
 * unbound state (i.e., without RTA_IFP), and for which an ire_ill is not
 * currently defined. These routes are then 'rebound', i.e., their ire_ill
 * is selected by finding an interface route for the gateway.
 */
/* ARGSUSED */
void
ip_ire_rebind_walker(ire_t *ire, void *notused)
{
        if (!ire->ire_unbound || ire->ire_ill != NULL)
                return;
        ire_rebind(ire);
        ire_delete(ire);
}

/*
 * When the src multihoming is changed from  [strong, preferred] to weak,
 * ip_ire_unbind_walker is called to walk the list of all ire_t entries, and
 * set any entries that were created by user-applications in the unbound state
 * (i.e., without RTA_IFP) back to having a NULL ire_ill.
 */
/* ARGSUSED */
void
ip_ire_unbind_walker(ire_t *ire, void *notused)
{
        ire_t *new_ire;

        if (!ire->ire_unbound || ire->ire_ill == NULL)
                return;
        if (ire->ire_ipversion == IPV6_VERSION) {
                new_ire = ire_create_v6(&ire->ire_addr_v6, &ire->ire_mask_v6,
                    &ire->ire_gateway_addr_v6, ire->ire_type, NULL,
                    ire->ire_zoneid, ire->ire_flags, ire->ire_ipst);
        } else {
                new_ire = ire_create((uchar_t *)&ire->ire_addr,
                    (uchar_t *)&ire->ire_mask,
                    (uchar_t *)&ire->ire_gateway_addr, ire->ire_type, NULL,
                    ire->ire_zoneid, ire->ire_flags, ire->ire_ipst);
        }
        if (new_ire == NULL)
                return;
        new_ire->ire_unbound = B_TRUE;
        /*
         * The bound ire must first be deleted so that we don't return
         * the existing one on the attempt to add the unbound new_ire.
         */
        ire_delete(ire);
        new_ire = ire_add(new_ire);
        if (new_ire != NULL)
                ire_refrele(new_ire);
}

/*
 * When the settings of ip*_strict_src_multihoming tunables are changed,
 * all cached routes need to be recomputed. This recomputation needs to be
 * done when going from weaker to stronger modes so that the cached ire
 * for the connection does not violate the current ip*_strict_src_multihoming
 * setting. It also needs to be done when going from stronger to weaker modes,
 * so that we fall back to matching on the longest-matching-route (as opposed
 * to a shorter match that may have been selected in the strong mode
 * to satisfy src_multihoming settings).
 *
 * The cached ixa_ire entires for all conn_t entries are marked as
 * "verify" so that they will be recomputed for the next packet.
 */
void
conn_ire_revalidate(conn_t *connp, void *arg)
{
        boolean_t isv6 = (boolean_t)arg;

        if ((isv6 && connp->conn_ipversion != IPV6_VERSION) ||
            (!isv6 && connp->conn_ipversion != IPV4_VERSION))
                return;
        connp->conn_ixa->ixa_ire_generation = IRE_GENERATION_VERIFY;
}

/*
 * Handles both IPv4 and IPv6 reassembly - doing the out-of-order cases,
 * When an ipf is passed here for the first time, if
 * we already have in-order fragments on the queue, we convert from the fast-
 * path reassembly scheme to the hard-case scheme.  From then on, additional
 * fragments are reassembled here.  We keep track of the start and end offsets
 * of each piece, and the number of holes in the chain.  When the hole count
 * goes to zero, we are done!
 *
 * The ipf_count will be updated to account for any mblk(s) added (pointed to
 * by mp) or subtracted (freeb()ed dups), upon return the caller must update
 * ipfb_count and ill_frag_count by the difference of ipf_count before and
 * after the call to ip_reassemble().
 */
int
ip_reassemble(mblk_t *mp, ipf_t *ipf, uint_t start, boolean_t more, ill_t *ill,
    size_t msg_len)
{
        uint_t  end;
        mblk_t  *next_mp;
        mblk_t  *mp1;
        uint_t  offset;
        boolean_t incr_dups = B_TRUE;
        boolean_t offset_zero_seen = B_FALSE;
        boolean_t pkt_boundary_checked = B_FALSE;

        /* If start == 0 then ipf_nf_hdr_len has to be set. */
        ASSERT(start != 0 || ipf->ipf_nf_hdr_len != 0);

        /* Add in byte count */
        ipf->ipf_count += msg_len;
        if (ipf->ipf_end) {
                /*
                 * We were part way through in-order reassembly, but now there
                 * is a hole.  We walk through messages already queued, and
                 * mark them for hard case reassembly.  We know that up till
                 * now they were in order starting from offset zero.
                 */
                offset = 0;
                for (mp1 = ipf->ipf_mp->b_cont; mp1; mp1 = mp1->b_cont) {
                        IP_REASS_SET_START(mp1, offset);
                        if (offset == 0) {
                                ASSERT(ipf->ipf_nf_hdr_len != 0);
                                offset = -ipf->ipf_nf_hdr_len;
                        }
                        offset += mp1->b_wptr - mp1->b_rptr;
                        IP_REASS_SET_END(mp1, offset);
                }
                /* One hole at the end. */
                ipf->ipf_hole_cnt = 1;
                /* Brand it as a hard case, forever. */
                ipf->ipf_end = 0;
        }
        /* Walk through all the new pieces. */
        do {
                end = start + (mp->b_wptr - mp->b_rptr);
                /*
                 * If start is 0, decrease 'end' only for the first mblk of
                 * the fragment. Otherwise 'end' can get wrong value in the
                 * second pass of the loop if first mblk is exactly the
                 * size of ipf_nf_hdr_len.
                 */
                if (start == 0 && !offset_zero_seen) {
                        /* First segment */
                        ASSERT(ipf->ipf_nf_hdr_len != 0);
                        end -= ipf->ipf_nf_hdr_len;
                        offset_zero_seen = B_TRUE;
                }
                next_mp = mp->b_cont;
                /*
                 * We are checking to see if there is any interesing data
                 * to process.  If there isn't and the mblk isn't the
                 * one which carries the unfragmentable header then we
                 * drop it.  It's possible to have just the unfragmentable
                 * header come through without any data.  That needs to be
                 * saved.
                 *
                 * If the assert at the top of this function holds then the
                 * term "ipf->ipf_nf_hdr_len != 0" isn't needed.  This code
                 * is infrequently traveled enough that the test is left in
                 * to protect against future code changes which break that
                 * invariant.
                 */
                if (start == end && start != 0 && ipf->ipf_nf_hdr_len != 0) {
                        /* Empty.  Blast it. */
                        IP_REASS_SET_START(mp, 0);
                        IP_REASS_SET_END(mp, 0);
                        /*
                         * If the ipf points to the mblk we are about to free,
                         * update ipf to point to the next mblk (or NULL
                         * if none).
                         */
                        if (ipf->ipf_mp->b_cont == mp)
                                ipf->ipf_mp->b_cont = next_mp;
                        freeb(mp);
                        continue;
                }
                mp->b_cont = NULL;
                IP_REASS_SET_START(mp, start);
                IP_REASS_SET_END(mp, end);
                if (!ipf->ipf_tail_mp) {
                        ipf->ipf_tail_mp = mp;
                        ipf->ipf_mp->b_cont = mp;
                        if (start == 0 || !more) {
                                ipf->ipf_hole_cnt = 1;
                                /*
                                 * if the first fragment comes in more than one
                                 * mblk, this loop will be executed for each
                                 * mblk. Need to adjust hole count so exiting
                                 * this routine will leave hole count at 1.
                                 */
                                if (next_mp)
                                        ipf->ipf_hole_cnt++;
                        } else
                                ipf->ipf_hole_cnt = 2;
                        continue;
                } else if (ipf->ipf_last_frag_seen && !more &&
                    !pkt_boundary_checked) {
                        /*
                         * We check datagram boundary only if this fragment
                         * claims to be the last fragment and we have seen a
                         * last fragment in the past too. We do this only
                         * once for a given fragment.
                         *
                         * start cannot be 0 here as fragments with start=0
                         * and MF=0 gets handled as a complete packet. These
                         * fragments should not reach here.
                         */

                        if (start + msgdsize(mp) !=
                            IP_REASS_END(ipf->ipf_tail_mp)) {
                                /*
                                 * We have two fragments both of which claim
                                 * to be the last fragment but gives conflicting
                                 * information about the whole datagram size.
                                 * Something fishy is going on. Drop the
                                 * fragment and free up the reassembly list.
                                 */
                                return (IP_REASS_FAILED);
                        }

                        /*
                         * We shouldn't come to this code block again for this
                         * particular fragment.
                         */
                        pkt_boundary_checked = B_TRUE;
                }

                /* New stuff at or beyond tail? */
                offset = IP_REASS_END(ipf->ipf_tail_mp);
                if (start >= offset) {
                        if (ipf->ipf_last_frag_seen) {
                                /* current fragment is beyond last fragment */
                                return (IP_REASS_FAILED);
                        }
                        /* Link it on end. */
                        ipf->ipf_tail_mp->b_cont = mp;
                        ipf->ipf_tail_mp = mp;
                        if (more) {
                                if (start != offset)
                                        ipf->ipf_hole_cnt++;
                        } else if (start == offset && next_mp == NULL)
                                        ipf->ipf_hole_cnt--;
                        continue;
                }
                mp1 = ipf->ipf_mp->b_cont;
                offset = IP_REASS_START(mp1);
                /* New stuff at the front? */
                if (start < offset) {
                        if (start == 0) {
                                if (end >= offset) {
                                        /* Nailed the hole at the begining. */
                                        ipf->ipf_hole_cnt--;
                                }
                        } else if (end < offset) {
                                /*
                                 * A hole, stuff, and a hole where there used
                                 * to be just a hole.
                                 */
                                ipf->ipf_hole_cnt++;
                        }
                        mp->b_cont = mp1;
                        /* Check for overlap. */
                        while (end > offset) {
                                if (end < IP_REASS_END(mp1)) {
                                        mp->b_wptr -= end - offset;
                                        IP_REASS_SET_END(mp, offset);
                                        BUMP_MIB(ill->ill_ip_mib,
                                            ipIfStatsReasmPartDups);
                                        break;
                                }
                                /* Did we cover another hole? */
                                if ((mp1->b_cont &&
                                    IP_REASS_END(mp1) !=
                                    IP_REASS_START(mp1->b_cont) &&
                                    end >= IP_REASS_START(mp1->b_cont)) ||
                                    (!ipf->ipf_last_frag_seen && !more)) {
                                        ipf->ipf_hole_cnt--;
                                }
                                /* Clip out mp1. */
                                if ((mp->b_cont = mp1->b_cont) == NULL) {
                                        /*
                                         * After clipping out mp1, this guy
                                         * is now hanging off the end.
                                         */
                                        ipf->ipf_tail_mp = mp;
                                }
                                IP_REASS_SET_START(mp1, 0);
                                IP_REASS_SET_END(mp1, 0);
                                /* Subtract byte count */
                                ipf->ipf_count -= mp1->b_datap->db_lim -
                                    mp1->b_datap->db_base;
                                freeb(mp1);
                                BUMP_MIB(ill->ill_ip_mib,
                                    ipIfStatsReasmPartDups);
                                mp1 = mp->b_cont;
                                if (!mp1)
                                        break;
                                offset = IP_REASS_START(mp1);
                        }
                        ipf->ipf_mp->b_cont = mp;
                        continue;
                }
                /*
                 * The new piece starts somewhere between the start of the head
                 * and before the end of the tail.
                 */
                for (; mp1; mp1 = mp1->b_cont) {
                        offset = IP_REASS_END(mp1);
                        if (start < offset) {
                                if (end <= offset) {
                                        /* Nothing new. */
                                        IP_REASS_SET_START(mp, 0);
                                        IP_REASS_SET_END(mp, 0);
                                        /* Subtract byte count */
                                        ipf->ipf_count -= mp->b_datap->db_lim -
                                            mp->b_datap->db_base;
                                        if (incr_dups) {
                                                ipf->ipf_num_dups++;
                                                incr_dups = B_FALSE;
                                        }
                                        freeb(mp);
                                        BUMP_MIB(ill->ill_ip_mib,
                                            ipIfStatsReasmDuplicates);
                                        break;
                                }
                                /*
                                 * Trim redundant stuff off beginning of new
                                 * piece.
                                 */
                                IP_REASS_SET_START(mp, offset);
                                mp->b_rptr += offset - start;
                                BUMP_MIB(ill->ill_ip_mib,
                                    ipIfStatsReasmPartDups);
                                start = offset;
                                if (!mp1->b_cont) {
                                        /*
                                         * After trimming, this guy is now
                                         * hanging off the end.
                                         */
                                        mp1->b_cont = mp;
                                        ipf->ipf_tail_mp = mp;
                                        if (!more) {
                                                ipf->ipf_hole_cnt--;
                                        }
                                        break;
                                }
                        }
                        if (start >= IP_REASS_START(mp1->b_cont))
                                continue;
                        /* Fill a hole */
                        if (start > offset)
                                ipf->ipf_hole_cnt++;
                        mp->b_cont = mp1->b_cont;
                        mp1->b_cont = mp;
                        mp1 = mp->b_cont;
                        offset = IP_REASS_START(mp1);
                        if (end >= offset) {
                                ipf->ipf_hole_cnt--;
                                /* Check for overlap. */
                                while (end > offset) {
                                        if (end < IP_REASS_END(mp1)) {
                                                mp->b_wptr -= end - offset;
                                                IP_REASS_SET_END(mp, offset);
                                                /*
                                                 * TODO we might bump
                                                 * this up twice if there is
                                                 * overlap at both ends.
                                                 */
                                                BUMP_MIB(ill->ill_ip_mib,
                                                    ipIfStatsReasmPartDups);
                                                break;
                                        }
                                        /* Did we cover another hole? */
                                        if ((mp1->b_cont &&
                                            IP_REASS_END(mp1)
                                            != IP_REASS_START(mp1->b_cont) &&
                                            end >=
                                            IP_REASS_START(mp1->b_cont)) ||
                                            (!ipf->ipf_last_frag_seen &&
                                            !more)) {
                                                ipf->ipf_hole_cnt--;
                                        }
                                        /* Clip out mp1. */
                                        if ((mp->b_cont = mp1->b_cont) ==
                                            NULL) {
                                                /*
                                                 * After clipping out mp1,
                                                 * this guy is now hanging
                                                 * off the end.
                                                 */
                                                ipf->ipf_tail_mp = mp;
                                        }
                                        IP_REASS_SET_START(mp1, 0);
                                        IP_REASS_SET_END(mp1, 0);
                                        /* Subtract byte count */
                                        ipf->ipf_count -=
                                            mp1->b_datap->db_lim -
                                            mp1->b_datap->db_base;
                                        freeb(mp1);
                                        BUMP_MIB(ill->ill_ip_mib,
                                            ipIfStatsReasmPartDups);
                                        mp1 = mp->b_cont;
                                        if (!mp1)
                                                break;
                                        offset = IP_REASS_START(mp1);
                                }
                        }
                        break;
                }
        } while (start = end, mp = next_mp);

        /* Fragment just processed could be the last one. Remember this fact */
        if (!more)
                ipf->ipf_last_frag_seen = B_TRUE;

        /* Still got holes? */
        if (ipf->ipf_hole_cnt)
                return (IP_REASS_PARTIAL);
        /* Clean up overloaded fields to avoid upstream disasters. */
        for (mp1 = ipf->ipf_mp->b_cont; mp1; mp1 = mp1->b_cont) {
                IP_REASS_SET_START(mp1, 0);
                IP_REASS_SET_END(mp1, 0);
        }
        return (IP_REASS_COMPLETE);
}

/*
 * Fragmentation reassembly.  Each ILL has a hash table for
 * queuing packets undergoing reassembly for all IPIFs
 * associated with the ILL.  The hash is based on the packet
 * IP ident field.  The ILL frag hash table was allocated
 * as a timer block at the time the ILL was created.  Whenever
 * there is anything on the reassembly queue, the timer will
 * be running.  Returns the reassembled packet if reassembly completes.
 */
mblk_t *
ip_input_fragment(mblk_t *mp, ipha_t *ipha, ip_recv_attr_t *ira)
{
        uint32_t        frag_offset_flags;
        mblk_t          *t_mp;
        ipaddr_t        dst;
        uint8_t         proto = ipha->ipha_protocol;
        uint32_t        sum_val;
        uint16_t        sum_flags;
        ipf_t           *ipf;
        ipf_t           **ipfp;
        ipfb_t          *ipfb;
        uint16_t        ident;
        uint32_t        offset;
        ipaddr_t        src;
        uint_t          hdr_length;
        uint32_t        end;
        mblk_t          *mp1;
        mblk_t          *tail_mp;
        size_t          count;
        size_t          msg_len;
        uint8_t         ecn_info = 0;
        uint32_t        packet_size;
        boolean_t       pruned = B_FALSE;
        ill_t           *ill = ira->ira_ill;
        ip_stack_t      *ipst = ill->ill_ipst;

        /*
         * Drop the fragmented as early as possible, if
         * we don't have resource(s) to re-assemble.
         */
        if (ipst->ips_ip_reass_queue_bytes == 0) {
                freemsg(mp);
                return (NULL);
        }

        /* Check for fragmentation offset; return if there's none */
        if ((frag_offset_flags = ntohs(ipha->ipha_fragment_offset_and_flags) &
            (IPH_MF | IPH_OFFSET)) == 0)
                return (mp);

        /*
         * We utilize hardware computed checksum info only for UDP since
         * IP fragmentation is a normal occurrence for the protocol.  In
         * addition, checksum offload support for IP fragments carrying
         * UDP payload is commonly implemented across network adapters.
         */
        ASSERT(ira->ira_rill != NULL);
        if (proto == IPPROTO_UDP && dohwcksum &&
            ILL_HCKSUM_CAPABLE(ira->ira_rill) &&
            (DB_CKSUMFLAGS(mp) & (HCK_FULLCKSUM | HCK_PARTIALCKSUM))) {
                mblk_t *mp1 = mp->b_cont;
                int32_t len;

                /* Record checksum information from the packet */
                sum_val = (uint32_t)DB_CKSUM16(mp);
                sum_flags = DB_CKSUMFLAGS(mp);

                /* IP payload offset from beginning of mblk */
                offset = ((uchar_t *)ipha + IPH_HDR_LENGTH(ipha)) - mp->b_rptr;

                if ((sum_flags & HCK_PARTIALCKSUM) &&
                    (mp1 == NULL || mp1->b_cont == NULL) &&
                    offset >= DB_CKSUMSTART(mp) &&
                    ((len = offset - DB_CKSUMSTART(mp)) & 1) == 0) {
                        uint32_t adj;
                        /*
                         * Partial checksum has been calculated by hardware
                         * and attached to the packet; in addition, any
                         * prepended extraneous data is even byte aligned.
                         * If any such data exists, we adjust the checksum;
                         * this would also handle any postpended data.
                         */
                        IP_ADJCKSUM_PARTIAL(mp->b_rptr + DB_CKSUMSTART(mp),
                            mp, mp1, len, adj);

                        /* One's complement subtract extraneous checksum */
                        if (adj >= sum_val)
                                sum_val = ~(adj - sum_val) & 0xFFFF;
                        else
                                sum_val -= adj;
                }
        } else {
                sum_val = 0;
                sum_flags = 0;
        }

        /* Clear hardware checksumming flag */
        DB_CKSUMFLAGS(mp) = 0;

        ident = ipha->ipha_ident;
        offset = (frag_offset_flags << 3) & 0xFFFF;
        src = ipha->ipha_src;
        dst = ipha->ipha_dst;
        hdr_length = IPH_HDR_LENGTH(ipha);
        end = ntohs(ipha->ipha_length) - hdr_length;

        /* If end == 0 then we have a packet with no data, so just free it */
        if (end == 0) {
                freemsg(mp);
                return (NULL);
        }

        /* Record the ECN field info. */
        ecn_info = (ipha->ipha_type_of_service & 0x3);
        if (offset != 0) {
                /*
                 * If this isn't the first piece, strip the header, and
                 * add the offset to the end value.
                 */
                mp->b_rptr += hdr_length;
                end += offset;
        }

        /* Handle vnic loopback of fragments */
        if (mp->b_datap->db_ref > 2)
                msg_len = 0;
        else
                msg_len = MBLKSIZE(mp);

        tail_mp = mp;
        while (tail_mp->b_cont != NULL) {
                tail_mp = tail_mp->b_cont;
                if (tail_mp->b_datap->db_ref <= 2)
                        msg_len += MBLKSIZE(tail_mp);
        }

        /* If the reassembly list for this ILL will get too big, prune it */
        if ((msg_len + sizeof (*ipf) + ill->ill_frag_count) >=
            ipst->ips_ip_reass_queue_bytes) {
                DTRACE_PROBE3(ip_reass_queue_bytes, uint_t, msg_len,
                    uint_t, ill->ill_frag_count,
                    uint_t, ipst->ips_ip_reass_queue_bytes);
                ill_frag_prune(ill,
                    (ipst->ips_ip_reass_queue_bytes < msg_len) ? 0 :
                    (ipst->ips_ip_reass_queue_bytes - msg_len));
                pruned = B_TRUE;
        }

        ipfb = &ill->ill_frag_hash_tbl[ILL_FRAG_HASH(src, ident)];
        mutex_enter(&ipfb->ipfb_lock);

        ipfp = &ipfb->ipfb_ipf;
        /* Try to find an existing fragment queue for this packet. */
        for (;;) {
                ipf = ipfp[0];
                if (ipf != NULL) {
                        /*
                         * It has to match on ident and src/dst address.
                         */
                        if (ipf->ipf_ident == ident &&
                            ipf->ipf_src == src &&
                            ipf->ipf_dst == dst &&
                            ipf->ipf_protocol == proto) {
                                /*
                                 * If we have received too many
                                 * duplicate fragments for this packet
                                 * free it.
                                 */
                                if (ipf->ipf_num_dups > ip_max_frag_dups) {
                                        ill_frag_free_pkts(ill, ipfb, ipf, 1);
                                        freemsg(mp);
                                        mutex_exit(&ipfb->ipfb_lock);
                                        return (NULL);
                                }
                                /* Found it. */
                                break;
                        }
                        ipfp = &ipf->ipf_hash_next;
                        continue;
                }

                /*
                 * If we pruned the list, do we want to store this new
                 * fragment?. We apply an optimization here based on the
                 * fact that most fragments will be received in order.
                 * So if the offset of this incoming fragment is zero,
                 * it is the first fragment of a new packet. We will
                 * keep it.  Otherwise drop the fragment, as we have
                 * probably pruned the packet already (since the
                 * packet cannot be found).
                 */
                if (pruned && offset != 0) {
                        mutex_exit(&ipfb->ipfb_lock);
                        freemsg(mp);
                        return (NULL);
                }

                if (ipfb->ipfb_frag_pkts >= MAX_FRAG_PKTS(ipst))  {
                        /*
                         * Too many fragmented packets in this hash
                         * bucket. Free the oldest.
                         */
                        ill_frag_free_pkts(ill, ipfb, ipfb->ipfb_ipf, 1);
                }

                /* New guy.  Allocate a frag message. */
                mp1 = allocb(sizeof (*ipf), BPRI_MED);
                if (mp1 == NULL) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                        ip_drop_input("ipIfStatsInDiscards", mp, ill);
                        freemsg(mp);
reass_done:
                        mutex_exit(&ipfb->ipfb_lock);
                        return (NULL);
                }

                BUMP_MIB(ill->ill_ip_mib, ipIfStatsReasmReqds);
                mp1->b_cont = mp;

                /* Initialize the fragment header. */
                ipf = (ipf_t *)mp1->b_rptr;
                ipf->ipf_mp = mp1;
                ipf->ipf_ptphn = ipfp;
                ipfp[0] = ipf;
                ipf->ipf_hash_next = NULL;
                ipf->ipf_ident = ident;
                ipf->ipf_protocol = proto;
                ipf->ipf_src = src;
                ipf->ipf_dst = dst;
                ipf->ipf_nf_hdr_len = 0;
                /* Record reassembly start time. */
                ipf->ipf_timestamp = gethrestime_sec();
                /* Record ipf generation and account for frag header */
                ipf->ipf_gen = ill->ill_ipf_gen++;
                ipf->ipf_count = MBLKSIZE(mp1);
                ipf->ipf_last_frag_seen = B_FALSE;
                ipf->ipf_ecn = ecn_info;
                ipf->ipf_num_dups = 0;
                ipfb->ipfb_frag_pkts++;
                ipf->ipf_checksum = 0;
                ipf->ipf_checksum_flags = 0;

                /* Store checksum value in fragment header */
                if (sum_flags != 0) {
                        sum_val = (sum_val & 0xFFFF) + (sum_val >> 16);
                        sum_val = (sum_val & 0xFFFF) + (sum_val >> 16);
                        ipf->ipf_checksum = sum_val;
                        ipf->ipf_checksum_flags = sum_flags;
                }

                /*
                 * We handle reassembly two ways.  In the easy case,
                 * where all the fragments show up in order, we do
                 * minimal bookkeeping, and just clip new pieces on
                 * the end.  If we ever see a hole, then we go off
                 * to ip_reassemble which has to mark the pieces and
                 * keep track of the number of holes, etc.  Obviously,
                 * the point of having both mechanisms is so we can
                 * handle the easy case as efficiently as possible.
                 */
                if (offset == 0) {
                        /* Easy case, in-order reassembly so far. */
                        ipf->ipf_count += msg_len;
                        ipf->ipf_tail_mp = tail_mp;
                        /*
                         * Keep track of next expected offset in
                         * ipf_end.
                         */
                        ipf->ipf_end = end;
                        ipf->ipf_nf_hdr_len = hdr_length;
                } else {
                        /* Hard case, hole at the beginning. */
                        ipf->ipf_tail_mp = NULL;
                        /*
                         * ipf_end == 0 means that we have given up
                         * on easy reassembly.
                         */
                        ipf->ipf_end = 0;

                        /* Forget checksum offload from now on */
                        ipf->ipf_checksum_flags = 0;

                        /*
                         * ipf_hole_cnt is set by ip_reassemble.
                         * ipf_count is updated by ip_reassemble.
                         * No need to check for return value here
                         * as we don't expect reassembly to complete
                         * or fail for the first fragment itself.
                         */
                        (void) ip_reassemble(mp, ipf,
                            (frag_offset_flags & IPH_OFFSET) << 3,
                            (frag_offset_flags & IPH_MF), ill, msg_len);
                }
                /* Update per ipfb and ill byte counts */
                ipfb->ipfb_count += ipf->ipf_count;
                ASSERT(ipfb->ipfb_count > 0);   /* Wraparound */
                atomic_add_32(&ill->ill_frag_count, ipf->ipf_count);
                /* If the frag timer wasn't already going, start it. */
                mutex_enter(&ill->ill_lock);
                ill_frag_timer_start(ill);
                mutex_exit(&ill->ill_lock);
                goto reass_done;
        }

        /*
         * If the packet's flag has changed (it could be coming up
         * from an interface different than the previous, therefore
         * possibly different checksum capability), then forget about
         * any stored checksum states.  Otherwise add the value to
         * the existing one stored in the fragment header.
         */
        if (sum_flags != 0 && sum_flags == ipf->ipf_checksum_flags) {
                sum_val += ipf->ipf_checksum;
                sum_val = (sum_val & 0xFFFF) + (sum_val >> 16);
                sum_val = (sum_val & 0xFFFF) + (sum_val >> 16);
                ipf->ipf_checksum = sum_val;
        } else if (ipf->ipf_checksum_flags != 0) {
                /* Forget checksum offload from now on */
                ipf->ipf_checksum_flags = 0;
        }

        /*
         * We have a new piece of a datagram which is already being
         * reassembled.  Update the ECN info if all IP fragments
         * are ECN capable.  If there is one which is not, clear
         * all the info.  If there is at least one which has CE
         * code point, IP needs to report that up to transport.
         */
        if (ecn_info != IPH_ECN_NECT && ipf->ipf_ecn != IPH_ECN_NECT) {
                if (ecn_info == IPH_ECN_CE)
                        ipf->ipf_ecn = IPH_ECN_CE;
        } else {
                ipf->ipf_ecn = IPH_ECN_NECT;
        }
        if (offset && ipf->ipf_end == offset) {
                /* The new fragment fits at the end */
                ipf->ipf_tail_mp->b_cont = mp;
                /* Update the byte count */
                ipf->ipf_count += msg_len;
                /* Update per ipfb and ill byte counts */
                ipfb->ipfb_count += msg_len;
                ASSERT(ipfb->ipfb_count > 0);   /* Wraparound */
                atomic_add_32(&ill->ill_frag_count, msg_len);
                if (frag_offset_flags & IPH_MF) {
                        /* More to come. */
                        ipf->ipf_end = end;
                        ipf->ipf_tail_mp = tail_mp;
                        goto reass_done;
                }
        } else {
                /* Go do the hard cases. */
                int ret;

                if (offset == 0)
                        ipf->ipf_nf_hdr_len = hdr_length;

                /* Save current byte count */
                count = ipf->ipf_count;
                ret = ip_reassemble(mp, ipf,
                    (frag_offset_flags & IPH_OFFSET) << 3,
                    (frag_offset_flags & IPH_MF), ill, msg_len);
                /* Count of bytes added and subtracted (freeb()ed) */
                count = ipf->ipf_count - count;
                if (count) {
                        /* Update per ipfb and ill byte counts */
                        ipfb->ipfb_count += count;
                        ASSERT(ipfb->ipfb_count > 0); /* Wraparound */
                        atomic_add_32(&ill->ill_frag_count, count);
                }
                if (ret == IP_REASS_PARTIAL) {
                        goto reass_done;
                } else if (ret == IP_REASS_FAILED) {
                        /* Reassembly failed. Free up all resources */
                        ill_frag_free_pkts(ill, ipfb, ipf, 1);
                        for (t_mp = mp; t_mp != NULL; t_mp = t_mp->b_cont) {
                                IP_REASS_SET_START(t_mp, 0);
                                IP_REASS_SET_END(t_mp, 0);
                        }
                        freemsg(mp);
                        goto reass_done;
                }
                /* We will reach here iff 'ret' is IP_REASS_COMPLETE */
        }
        /*
         * We have completed reassembly.  Unhook the frag header from
         * the reassembly list.
         *
         * Before we free the frag header, record the ECN info
         * to report back to the transport.
         */
        ecn_info = ipf->ipf_ecn;
        BUMP_MIB(ill->ill_ip_mib, ipIfStatsReasmOKs);
        ipfp = ipf->ipf_ptphn;

        /* We need to supply these to caller */
        if ((sum_flags = ipf->ipf_checksum_flags) != 0)
                sum_val = ipf->ipf_checksum;
        else
                sum_val = 0;

        mp1 = ipf->ipf_mp;
        count = ipf->ipf_count;
        ipf = ipf->ipf_hash_next;
        if (ipf != NULL)
                ipf->ipf_ptphn = ipfp;
        ipfp[0] = ipf;
        atomic_add_32(&ill->ill_frag_count, -count);
        ASSERT(ipfb->ipfb_count >= count);
        ipfb->ipfb_count -= count;
        ipfb->ipfb_frag_pkts--;
        mutex_exit(&ipfb->ipfb_lock);
        /* Ditch the frag header. */
        mp = mp1->b_cont;

        freeb(mp1);

        /* Restore original IP length in header. */
        packet_size = (uint32_t)msgdsize(mp);
        if (packet_size > IP_MAXPACKET) {
                BUMP_MIB(ill->ill_ip_mib, ipIfStatsInHdrErrors);
                ip_drop_input("Reassembled packet too large", mp, ill);
                freemsg(mp);
                return (NULL);
        }

        if (DB_REF(mp) > 1) {
                mblk_t *mp2 = copymsg(mp);

                if (mp2 == NULL) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                        ip_drop_input("ipIfStatsInDiscards", mp, ill);
                        freemsg(mp);
                        return (NULL);
                }
                freemsg(mp);
                mp = mp2;
        }
        ipha = (ipha_t *)mp->b_rptr;

        ipha->ipha_length = htons((uint16_t)packet_size);
        /* We're now complete, zip the frag state */
        ipha->ipha_fragment_offset_and_flags = 0;
        /* Record the ECN info. */
        ipha->ipha_type_of_service &= 0xFC;
        ipha->ipha_type_of_service |= ecn_info;

        /* Update the receive attributes */
        ira->ira_pktlen = packet_size;
        ira->ira_ip_hdr_length = IPH_HDR_LENGTH(ipha);

        /* Reassembly is successful; set checksum information in packet */
        DB_CKSUM16(mp) = (uint16_t)sum_val;
        DB_CKSUMFLAGS(mp) = sum_flags;
        DB_CKSUMSTART(mp) = ira->ira_ip_hdr_length;

        return (mp);
}

/*
 * Pullup function that should be used for IP input in order to
 * ensure we do not loose the L2 source address; we need the l2 source
 * address for IP_RECVSLLA and for ndp_input.
 *
 * We return either NULL or b_rptr.
 */
void *
ip_pullup(mblk_t *mp, ssize_t len, ip_recv_attr_t *ira)
{
        ill_t           *ill = ira->ira_ill;

        if (ip_rput_pullups++ == 0) {
                (void) mi_strlog(ill->ill_rq, 1, SL_ERROR|SL_TRACE,
                    "ip_pullup: %s forced us to "
                    " pullup pkt, hdr len %ld, hdr addr %p",
                    ill->ill_name, len, (void *)mp->b_rptr);
        }
        if (!(ira->ira_flags & IRAF_L2SRC_SET))
                ip_setl2src(mp, ira, ira->ira_rill);
        ASSERT(ira->ira_flags & IRAF_L2SRC_SET);
        if (!pullupmsg(mp, len))
                return (NULL);
        else
                return (mp->b_rptr);
}

/*
 * Make sure ira_l2src has an address. If we don't have one fill with zeros.
 * When called from the ULP ira_rill will be NULL hence the caller has to
 * pass in the ill.
 */
/* ARGSUSED */
void
ip_setl2src(mblk_t *mp, ip_recv_attr_t *ira, ill_t *ill)
{
        const uchar_t *addr;
        int alen;

        if (ira->ira_flags & IRAF_L2SRC_SET)
                return;

        ASSERT(ill != NULL);
        alen = ill->ill_phys_addr_length;
        ASSERT(alen <= sizeof (ira->ira_l2src));
        if (ira->ira_mhip != NULL &&
            (addr = ira->ira_mhip->mhi_saddr) != NULL) {
                bcopy(addr, ira->ira_l2src, alen);
        } else if ((ira->ira_flags & IRAF_L2SRC_LOOPBACK) &&
            (addr = ill->ill_phys_addr) != NULL) {
                bcopy(addr, ira->ira_l2src, alen);
        } else {
                bzero(ira->ira_l2src, alen);
        }
        ira->ira_flags |= IRAF_L2SRC_SET;
}

/*
 * check ip header length and align it.
 */
mblk_t *
ip_check_and_align_header(mblk_t *mp, uint_t min_size, ip_recv_attr_t *ira)
{
        ill_t   *ill = ira->ira_ill;
        ssize_t len;

        len = MBLKL(mp);

        if (!OK_32PTR(mp->b_rptr))
                IP_STAT(ill->ill_ipst, ip_notaligned);
        else
                IP_STAT(ill->ill_ipst, ip_recv_pullup);

        /* Guard against bogus device drivers */
        if (len < 0) {
                BUMP_MIB(ill->ill_ip_mib, ipIfStatsInHdrErrors);
                ip_drop_input("ipIfStatsInHdrErrors", mp, ill);
                freemsg(mp);
                return (NULL);
        }

        if (len == 0) {
                /* GLD sometimes sends up mblk with b_rptr == b_wptr! */
                mblk_t *mp1 = mp->b_cont;

                if (!(ira->ira_flags & IRAF_L2SRC_SET))
                        ip_setl2src(mp, ira, ira->ira_rill);
                ASSERT(ira->ira_flags & IRAF_L2SRC_SET);

                freeb(mp);
                mp = mp1;
                if (mp == NULL)
                        return (NULL);

                if (OK_32PTR(mp->b_rptr) && MBLKL(mp) >= min_size)
                        return (mp);
        }
        if (ip_pullup(mp, min_size, ira) == NULL) {
                if (msgdsize(mp) < min_size) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInHdrErrors);
                        ip_drop_input("ipIfStatsInHdrErrors", mp, ill);
                } else {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                        ip_drop_input("ipIfStatsInDiscards", mp, ill);
                }
                freemsg(mp);
                return (NULL);
        }
        return (mp);
}

/*
 * Common code for IPv4 and IPv6 to check and pullup multi-mblks
 */
mblk_t *
ip_check_length(mblk_t *mp, uchar_t *rptr, ssize_t len, uint_t pkt_len,
    uint_t min_size, ip_recv_attr_t *ira)
{
        ill_t   *ill = ira->ira_ill;

        /*
         * Make sure we have data length consistent
         * with the IP header.
         */
        if (mp->b_cont == NULL) {
                /* pkt_len is based on ipha_len, not the mblk length */
                if (pkt_len < min_size) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInHdrErrors);
                        ip_drop_input("ipIfStatsInHdrErrors", mp, ill);
                        freemsg(mp);
                        return (NULL);
                }
                if (len < 0) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInTruncatedPkts);
                        ip_drop_input("ipIfStatsInTruncatedPkts", mp, ill);
                        freemsg(mp);
                        return (NULL);
                }
                /* Drop any pad */
                mp->b_wptr = rptr + pkt_len;
        } else if ((len += msgdsize(mp->b_cont)) != 0) {
                ASSERT(pkt_len >= min_size);
                if (pkt_len < min_size) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInHdrErrors);
                        ip_drop_input("ipIfStatsInHdrErrors", mp, ill);
                        freemsg(mp);
                        return (NULL);
                }
                if (len < 0) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInTruncatedPkts);
                        ip_drop_input("ipIfStatsInTruncatedPkts", mp, ill);
                        freemsg(mp);
                        return (NULL);
                }
                /* Drop any pad */
                (void) adjmsg(mp, -len);
                /*
                 * adjmsg may have freed an mblk from the chain, hence
                 * invalidate any hw checksum here. This will force IP to
                 * calculate the checksum in sw, but only for this packet.
                 */
                DB_CKSUMFLAGS(mp) = 0;
                IP_STAT(ill->ill_ipst, ip_multimblk);
        }
        return (mp);
}

/*
 * Check that the IPv4 opt_len is consistent with the packet and pullup
 * the options.
 */
mblk_t *
ip_check_optlen(mblk_t *mp, ipha_t *ipha, uint_t opt_len, uint_t pkt_len,
    ip_recv_attr_t *ira)
{
        ill_t   *ill = ira->ira_ill;
        ssize_t len;

        /* Assume no IPv6 packets arrive over the IPv4 queue */
        if (IPH_HDR_VERSION(ipha) != IPV4_VERSION) {
                BUMP_MIB(ill->ill_ip_mib, ipIfStatsInHdrErrors);
                BUMP_MIB(ill->ill_ip_mib, ipIfStatsInWrongIPVersion);
                ip_drop_input("IPvN packet on IPv4 ill", mp, ill);
                freemsg(mp);
                return (NULL);
        }

        if (opt_len > (15 - IP_SIMPLE_HDR_LENGTH_IN_WORDS)) {
                BUMP_MIB(ill->ill_ip_mib, ipIfStatsInHdrErrors);
                ip_drop_input("ipIfStatsInHdrErrors", mp, ill);
                freemsg(mp);
                return (NULL);
        }
        /*
         * Recompute complete header length and make sure we
         * have access to all of it.
         */
        len = ((size_t)opt_len + IP_SIMPLE_HDR_LENGTH_IN_WORDS) << 2;
        if (len > (mp->b_wptr - mp->b_rptr)) {
                if (len > pkt_len) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInHdrErrors);
                        ip_drop_input("ipIfStatsInHdrErrors", mp, ill);
                        freemsg(mp);
                        return (NULL);
                }
                if (ip_pullup(mp, len, ira) == NULL) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                        ip_drop_input("ipIfStatsInDiscards", mp, ill);
                        freemsg(mp);
                        return (NULL);
                }
        }
        return (mp);
}

/*
 * Returns a new ire, or the same ire, or NULL.
 * If a different IRE is returned, then it is held; the caller
 * needs to release it.
 * In no case is there any hold/release on the ire argument.
 */
ire_t *
ip_check_multihome(void *addr, ire_t *ire, ill_t *ill)
{
        ire_t           *new_ire;
        ill_t           *ire_ill;
        uint_t          ifindex;
        ip_stack_t      *ipst = ill->ill_ipst;
        boolean_t       strict_check = B_FALSE;

        /*
         * IPMP common case: if IRE and ILL are in the same group, there's no
         * issue (e.g. packet received on an underlying interface matched an
         * IRE_LOCAL on its associated group interface).
         */
        ASSERT(ire->ire_ill != NULL);
        if (IS_IN_SAME_ILLGRP(ill, ire->ire_ill))
                return (ire);

        /*
         * Do another ire lookup here, using the ingress ill, to see if the
         * interface is in a usesrc group.
         * As long as the ills belong to the same group, we don't consider
         * them to be arriving on the wrong interface. Thus, if the switch
         * is doing inbound load spreading, we won't drop packets when the
         * ip*_strict_dst_multihoming switch is on.
         * We also need to check for IPIF_UNNUMBERED point2point interfaces
         * where the local address may not be unique. In this case we were
         * at the mercy of the initial ire lookup and the IRE_LOCAL it
         * actually returned. The new lookup, which is more specific, should
         * only find the IRE_LOCAL associated with the ingress ill if one
         * exists.
         */
        if (ire->ire_ipversion == IPV4_VERSION) {
                if (ipst->ips_ip_strict_dst_multihoming)
                        strict_check = B_TRUE;
                new_ire = ire_ftable_lookup_v4(*((ipaddr_t *)addr), 0, 0,
                    IRE_LOCAL, ill, ALL_ZONES,
                    (MATCH_IRE_TYPE|MATCH_IRE_ILL), 0, ipst, NULL);
        } else {
                ASSERT(!IN6_IS_ADDR_MULTICAST((in6_addr_t *)addr));
                if (ipst->ips_ipv6_strict_dst_multihoming)
                        strict_check = B_TRUE;
                new_ire = ire_ftable_lookup_v6((in6_addr_t *)addr, NULL, NULL,
                    IRE_LOCAL, ill, ALL_ZONES,
                    (MATCH_IRE_TYPE|MATCH_IRE_ILL), 0, ipst, NULL);
        }
        /*
         * If the same ire that was returned in ip_input() is found then this
         * is an indication that usesrc groups are in use. The packet
         * arrived on a different ill in the group than the one associated with
         * the destination address.  If a different ire was found then the same
         * IP address must be hosted on multiple ills. This is possible with
         * unnumbered point2point interfaces. We switch to use this new ire in
         * order to have accurate interface statistics.
         */
        if (new_ire != NULL) {
                /* Note: held in one case but not the other? Caller handles */
                if (new_ire != ire)
                        return (new_ire);
                /* Unchanged */
                ire_refrele(new_ire);
                return (ire);
        }

        /*
         * Chase pointers once and store locally.
         */
        ASSERT(ire->ire_ill != NULL);
        ire_ill = ire->ire_ill;
        ifindex = ill->ill_usesrc_ifindex;

        /*
         * Check if it's a legal address on the 'usesrc' interface.
         * For IPMP data addresses the IRE_LOCAL is the upper, hence we
         * can just check phyint_ifindex.
         */
        if (ifindex != 0 && ifindex == ire_ill->ill_phyint->phyint_ifindex) {
                return (ire);
        }

        /*
         * If the ip*_strict_dst_multihoming switch is on then we can
         * only accept this packet if the interface is marked as routing.
         */
        if (!(strict_check))
                return (ire);

        if ((ill->ill_flags & ire->ire_ill->ill_flags & ILLF_ROUTER) != 0) {
                return (ire);
        }
        return (NULL);
}

/*
 * This function is used to construct a mac_header_info_s from a
 * DL_UNITDATA_IND message.
 * The address fields in the mhi structure points into the message,
 * thus the caller can't use those fields after freeing the message.
 *
 * We determine whether the packet received is a non-unicast packet
 * and in doing so, determine whether or not it is broadcast vs multicast.
 * For it to be a broadcast packet, we must have the appropriate mblk_t
 * hanging off the ill_t.  If this is either not present or doesn't match
 * the destination mac address in the DL_UNITDATA_IND, the packet is deemed
 * to be multicast.  Thus NICs that have no broadcast address (or no
 * capability for one, such as point to point links) cannot return as
 * the packet being broadcast.
 */
void
ip_dlur_to_mhi(ill_t *ill, mblk_t *mb, struct mac_header_info_s *mhip)
{
        dl_unitdata_ind_t *ind = (dl_unitdata_ind_t *)mb->b_rptr;
        mblk_t *bmp;
        uint_t extra_offset;

        bzero(mhip, sizeof (struct mac_header_info_s));

        mhip->mhi_dsttype = MAC_ADDRTYPE_UNICAST;

        if (ill->ill_sap_length < 0)
                extra_offset = 0;
        else
                extra_offset = ill->ill_sap_length;

        mhip->mhi_daddr = (uchar_t *)ind + ind->dl_dest_addr_offset +
            extra_offset;
        mhip->mhi_saddr = (uchar_t *)ind + ind->dl_src_addr_offset +
            extra_offset;

        if (!ind->dl_group_address)
                return;

        /* Multicast or broadcast */
        mhip->mhi_dsttype = MAC_ADDRTYPE_MULTICAST;

        if (ind->dl_dest_addr_offset > sizeof (*ind) &&
            ind->dl_dest_addr_offset + ind->dl_dest_addr_length < MBLKL(mb) &&
            (bmp = ill->ill_bcast_mp) != NULL) {
                dl_unitdata_req_t *dlur;
                uint8_t *bphys_addr;

                dlur = (dl_unitdata_req_t *)bmp->b_rptr;
                bphys_addr = (uchar_t *)dlur + dlur->dl_dest_addr_offset +
                    extra_offset;

                if (bcmp(mhip->mhi_daddr, bphys_addr,
                    ind->dl_dest_addr_length) == 0)
                        mhip->mhi_dsttype = MAC_ADDRTYPE_BROADCAST;
        }
}

/*
 * This function is used to construct a mac_header_info_s from a
 * M_DATA fastpath message from a DLPI driver.
 * The address fields in the mhi structure points into the message,
 * thus the caller can't use those fields after freeing the message.
 *
 * We determine whether the packet received is a non-unicast packet
 * and in doing so, determine whether or not it is broadcast vs multicast.
 * For it to be a broadcast packet, we must have the appropriate mblk_t
 * hanging off the ill_t.  If this is either not present or doesn't match
 * the destination mac address in the DL_UNITDATA_IND, the packet is deemed
 * to be multicast.  Thus NICs that have no broadcast address (or no
 * capability for one, such as point to point links) cannot return as
 * the packet being broadcast.
 */
void
ip_mdata_to_mhi(ill_t *ill, mblk_t *mp, struct mac_header_info_s *mhip)
{
        mblk_t *bmp;
        struct ether_header *pether;

        bzero(mhip, sizeof (struct mac_header_info_s));

        mhip->mhi_dsttype = MAC_ADDRTYPE_UNICAST;

        pether = (struct ether_header *)((char *)mp->b_rptr
            - sizeof (struct ether_header));

        /*
         * Make sure the interface is an ethernet type, since we don't
         * know the header format for anything but Ethernet. Also make
         * sure we are pointing correctly above db_base.
         */
        if (ill->ill_type != IFT_ETHER)
                return;

retry:
        if ((uchar_t *)pether < mp->b_datap->db_base)
                return;

        /* Is there a VLAN tag? */
        if (ill->ill_isv6) {
                if (pether->ether_type != htons(ETHERTYPE_IPV6)) {
                        pether = (struct ether_header *)((char *)pether - 4);
                        goto retry;
                }
        } else {
                if (pether->ether_type != htons(ETHERTYPE_IP)) {
                        pether = (struct ether_header *)((char *)pether - 4);
                        goto retry;
                }
        }
        mhip->mhi_daddr = (uchar_t *)&pether->ether_dhost;
        mhip->mhi_saddr = (uchar_t *)&pether->ether_shost;

        if (!(mhip->mhi_daddr[0] & 0x01))
                return;

        /* Multicast or broadcast */
        mhip->mhi_dsttype = MAC_ADDRTYPE_MULTICAST;

        if ((bmp = ill->ill_bcast_mp) != NULL) {
                dl_unitdata_req_t *dlur;
                uint8_t *bphys_addr;
                uint_t  addrlen;

                dlur = (dl_unitdata_req_t *)bmp->b_rptr;
                addrlen = dlur->dl_dest_addr_length;
                if (ill->ill_sap_length < 0) {
                        bphys_addr = (uchar_t *)dlur +
                            dlur->dl_dest_addr_offset;
                        addrlen += ill->ill_sap_length;
                } else {
                        bphys_addr = (uchar_t *)dlur +
                            dlur->dl_dest_addr_offset +
                            ill->ill_sap_length;
                        addrlen -= ill->ill_sap_length;
                }
                if (bcmp(mhip->mhi_daddr, bphys_addr, addrlen) == 0)
                        mhip->mhi_dsttype = MAC_ADDRTYPE_BROADCAST;
        }
}

/*
 * Handle anything but M_DATA messages
 * We see the DL_UNITDATA_IND which are part
 * of the data path, and also the other messages from the driver.
 */
void
ip_rput_notdata(ill_t *ill, mblk_t *mp)
{
        mblk_t          *first_mp;
        struct iocblk   *iocp;
        struct mac_header_info_s mhi;

        switch (DB_TYPE(mp)) {
        case M_PROTO:
        case M_PCPROTO: {
                if (((dl_unitdata_ind_t *)mp->b_rptr)->dl_primitive !=
                    DL_UNITDATA_IND) {
                        /* Go handle anything other than data elsewhere. */
                        ip_rput_dlpi(ill, mp);
                        return;
                }

                first_mp = mp;
                mp = first_mp->b_cont;
                first_mp->b_cont = NULL;

                if (mp == NULL) {
                        freeb(first_mp);
                        return;
                }
                ip_dlur_to_mhi(ill, first_mp, &mhi);
                if (ill->ill_isv6)
                        ip_input_v6(ill, NULL, mp, &mhi);
                else
                        ip_input(ill, NULL, mp, &mhi);

                /* Ditch the DLPI header. */
                freeb(first_mp);
                return;
        }
        case M_IOCACK:
                iocp = (struct iocblk *)mp->b_rptr;
                switch (iocp->ioc_cmd) {
                case DL_IOC_HDR_INFO:
                        ill_fastpath_ack(ill, mp);
                        return;
                default:
                        putnext(ill->ill_rq, mp);
                        return;
                }
                /* FALLTHROUGH */
        case M_ERROR:
        case M_HANGUP:
                mutex_enter(&ill->ill_lock);
                if (ill->ill_state_flags & ILL_CONDEMNED) {
                        mutex_exit(&ill->ill_lock);
                        freemsg(mp);
                        return;
                }
                ill_refhold_locked(ill);
                mutex_exit(&ill->ill_lock);
                qwriter_ip(ill, ill->ill_rq, mp, ip_rput_other, CUR_OP,
                    B_FALSE);
                return;
        case M_CTL:
                putnext(ill->ill_rq, mp);
                return;
        case M_IOCNAK:
                ip1dbg(("got iocnak "));
                iocp = (struct iocblk *)mp->b_rptr;
                switch (iocp->ioc_cmd) {
                case DL_IOC_HDR_INFO:
                        ip_rput_other(NULL, ill->ill_rq, mp, NULL);
                        return;
                default:
                        break;
                }
                /* FALLTHROUGH */
        default:
                putnext(ill->ill_rq, mp);
                return;
        }
}

/* Read side put procedure.  Packets coming from the wire arrive here. */
int
ip_rput(queue_t *q, mblk_t *mp)
{
        ill_t   *ill;
        union DL_primitives *dl;

        ill = (ill_t *)q->q_ptr;

        if (ill->ill_state_flags & (ILL_CONDEMNED | ILL_LL_SUBNET_PENDING)) {
                /*
                 * If things are opening or closing, only accept high-priority
                 * DLPI messages.  (On open ill->ill_ipif has not yet been
                 * created; on close, things hanging off the ill may have been
                 * freed already.)
                 */
                dl = (union DL_primitives *)mp->b_rptr;
                if (DB_TYPE(mp) != M_PCPROTO ||
                    dl->dl_primitive == DL_UNITDATA_IND) {
                        inet_freemsg(mp);
                        return (0);
                }
        }
        if (DB_TYPE(mp) == M_DATA) {
                struct mac_header_info_s mhi;

                ip_mdata_to_mhi(ill, mp, &mhi);
                ip_input(ill, NULL, mp, &mhi);
        } else {
                ip_rput_notdata(ill, mp);
        }
        return (0);
}

/*
 * Move the information to a copy.
 */
mblk_t *
ip_fix_dbref(mblk_t *mp, ip_recv_attr_t *ira)
{
        mblk_t          *mp1;
        ill_t           *ill = ira->ira_ill;
        ip_stack_t      *ipst = ill->ill_ipst;

        IP_STAT(ipst, ip_db_ref);

        /* Make sure we have ira_l2src before we loose the original mblk */
        if (!(ira->ira_flags & IRAF_L2SRC_SET))
                ip_setl2src(mp, ira, ira->ira_rill);

        mp1 = copymsg(mp);
        if (mp1 == NULL) {
                BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                ip_drop_input("ipIfStatsInDiscards", mp, ill);
                freemsg(mp);
                return (NULL);
        }
        /* preserve the hardware checksum flags and data, if present */
        if (DB_CKSUMFLAGS(mp) != 0) {
                DB_CKSUMFLAGS(mp1) = DB_CKSUMFLAGS(mp);
                DB_CKSUMSTART(mp1) = DB_CKSUMSTART(mp);
                DB_CKSUMSTUFF(mp1) = DB_CKSUMSTUFF(mp);
                DB_CKSUMEND(mp1) = DB_CKSUMEND(mp);
                DB_CKSUM16(mp1) = DB_CKSUM16(mp);
        }
        freemsg(mp);
        return (mp1);
}

static void
ip_dlpi_error(ill_t *ill, t_uscalar_t prim, t_uscalar_t dl_err,
    t_uscalar_t err)
{
        if (dl_err == DL_SYSERR) {
                (void) mi_strlog(ill->ill_rq, 1, SL_CONSOLE|SL_ERROR|SL_TRACE,
                    "%s: %s failed: DL_SYSERR (errno %u)\n",
                    ill->ill_name, dl_primstr(prim), err);
                return;
        }

        (void) mi_strlog(ill->ill_rq, 1, SL_CONSOLE|SL_ERROR|SL_TRACE,
            "%s: %s failed: %s\n", ill->ill_name, dl_primstr(prim),
            dl_errstr(dl_err));
}

/*
 * ip_rput_dlpi is called by ip_rput to handle all DLPI messages other
 * than DL_UNITDATA_IND messages. If we need to process this message
 * exclusively, we call qwriter_ip, in which case we also need to call
 * ill_refhold before that, since qwriter_ip does an ill_refrele.
 */
void
ip_rput_dlpi(ill_t *ill, mblk_t *mp)
{
        dl_ok_ack_t     *dloa = (dl_ok_ack_t *)mp->b_rptr;
        dl_error_ack_t  *dlea = (dl_error_ack_t *)dloa;
        queue_t         *q = ill->ill_rq;
        t_uscalar_t     prim = dloa->dl_primitive;
        t_uscalar_t     reqprim = DL_PRIM_INVAL;

        DTRACE_PROBE3(ill__dlpi, char *, "ip_rput_dlpi",
            char *, dl_primstr(prim), ill_t *, ill);
        ip1dbg(("ip_rput_dlpi"));

        /*
         * If we received an ACK but didn't send a request for it, then it
         * can't be part of any pending operation; discard up-front.
         */
        switch (prim) {
        case DL_ERROR_ACK:
                reqprim = dlea->dl_error_primitive;
                ip2dbg(("ip_rput_dlpi(%s): DL_ERROR_ACK for %s (0x%x): %s "
                    "(0x%x), unix %u\n", ill->ill_name, dl_primstr(reqprim),
                    reqprim, dl_errstr(dlea->dl_errno), dlea->dl_errno,
                    dlea->dl_unix_errno));
                break;
        case DL_OK_ACK:
                reqprim = dloa->dl_correct_primitive;
                break;
        case DL_INFO_ACK:
                reqprim = DL_INFO_REQ;
                break;
        case DL_BIND_ACK:
                reqprim = DL_BIND_REQ;
                break;
        case DL_PHYS_ADDR_ACK:
                reqprim = DL_PHYS_ADDR_REQ;
                break;
        case DL_NOTIFY_ACK:
                reqprim = DL_NOTIFY_REQ;
                break;
        case DL_CAPABILITY_ACK:
                reqprim = DL_CAPABILITY_REQ;
                break;
        }

        if (prim != DL_NOTIFY_IND) {
                if (reqprim == DL_PRIM_INVAL ||
                    !ill_dlpi_pending(ill, reqprim)) {
                        /* Not a DLPI message we support or expected */
                        freemsg(mp);
                        return;
                }
                ip1dbg(("ip_rput: received %s for %s\n", dl_primstr(prim),
                    dl_primstr(reqprim)));
        }

        switch (reqprim) {
        case DL_UNBIND_REQ:
                /*
                 * NOTE: we mark the unbind as complete even if we got a
                 * DL_ERROR_ACK, since there's not much else we can do.
                 */
                mutex_enter(&ill->ill_lock);
                ill->ill_state_flags &= ~ILL_DL_UNBIND_IN_PROGRESS;
                cv_signal(&ill->ill_cv);
                mutex_exit(&ill->ill_lock);
                break;

        case DL_ENABMULTI_REQ:
                if (prim == DL_OK_ACK) {
                        if (ill->ill_dlpi_multicast_state == IDS_INPROGRESS)
                                ill->ill_dlpi_multicast_state = IDS_OK;
                }
                break;
        }

        /*
         * The message is one we're waiting for (or DL_NOTIFY_IND), but we
         * need to become writer to continue to process it.  Because an
         * exclusive operation doesn't complete until replies to all queued
         * DLPI messages have been received, we know we're in the middle of an
         * exclusive operation and pass CUR_OP (except for DL_NOTIFY_IND).
         *
         * As required by qwriter_ip(), we refhold the ill; it will refrele.
         * Since this is on the ill stream we unconditionally bump up the
         * refcount without doing ILL_CAN_LOOKUP().
         */
        ill_refhold(ill);
        if (prim == DL_NOTIFY_IND)
                qwriter_ip(ill, q, mp, ip_rput_dlpi_writer, NEW_OP, B_FALSE);
        else
                qwriter_ip(ill, q, mp, ip_rput_dlpi_writer, CUR_OP, B_FALSE);
}

/*
 * Handling of DLPI messages that require exclusive access to the ipsq.
 *
 * Need to do ipsq_pending_mp_get on ioctl completion, which could
 * happen here. (along with mi_copy_done)
 */
/* ARGSUSED */
static void
ip_rput_dlpi_writer(ipsq_t *ipsq, queue_t *q, mblk_t *mp, void *dummy_arg)
{
        dl_ok_ack_t     *dloa = (dl_ok_ack_t *)mp->b_rptr;
        dl_error_ack_t  *dlea = (dl_error_ack_t *)dloa;
        int             err = 0;
        ill_t           *ill = (ill_t *)q->q_ptr;
        ipif_t          *ipif = NULL;
        mblk_t          *mp1 = NULL;
        conn_t          *connp = NULL;
        t_uscalar_t     paddrreq;
        mblk_t          *mp_hw;
        boolean_t       success;
        boolean_t       ioctl_aborted = B_FALSE;
        boolean_t       log = B_TRUE;

        DTRACE_PROBE3(ill__dlpi, char *, "ip_rput_dlpi_writer",
            char *, dl_primstr(dloa->dl_primitive), ill_t *, ill);

        ip1dbg(("ip_rput_dlpi_writer .."));
        ASSERT(ipsq->ipsq_xop == ill->ill_phyint->phyint_ipsq->ipsq_xop);
        ASSERT(IAM_WRITER_ILL(ill));

        ipif = ipsq->ipsq_xop->ipx_pending_ipif;
        /*
         * The current ioctl could have been aborted by the user and a new
         * ioctl to bring up another ill could have started. We could still
         * get a response from the driver later.
         */
        if (ipif != NULL && ipif->ipif_ill != ill)
                ioctl_aborted = B_TRUE;

        switch (dloa->dl_primitive) {
        case DL_ERROR_ACK:
                ip1dbg(("ip_rput_dlpi_writer: got DL_ERROR_ACK for %s\n",
                    dl_primstr(dlea->dl_error_primitive)));

                DTRACE_PROBE3(ill__dlpi, char *, "ip_rput_dlpi_writer error",
                    char *, dl_primstr(dlea->dl_error_primitive),
                    ill_t *, ill);

                switch (dlea->dl_error_primitive) {
                case DL_DISABMULTI_REQ:
                        ill_dlpi_done(ill, dlea->dl_error_primitive);
                        break;
                case DL_PROMISCON_REQ:
                case DL_PROMISCOFF_REQ:
                case DL_UNBIND_REQ:
                case DL_ATTACH_REQ:
                case DL_INFO_REQ:
                        ill_dlpi_done(ill, dlea->dl_error_primitive);
                        break;
                case DL_NOTIFY_REQ:
                        ill_dlpi_done(ill, DL_NOTIFY_REQ);
                        log = B_FALSE;
                        break;
                case DL_PHYS_ADDR_REQ:
                        /*
                         * For IPv6 only, there are two additional
                         * phys_addr_req's sent to the driver to get the
                         * IPv6 token and lla. This allows IP to acquire
                         * the hardware address format for a given interface
                         * without having built in knowledge of the hardware
                         * address. ill_phys_addr_pend keeps track of the last
                         * DL_PAR sent so we know which response we are
                         * dealing with. ill_dlpi_done will update
                         * ill_phys_addr_pend when it sends the next req.
                         * We don't complete the IOCTL until all three DL_PARs
                         * have been attempted, so set *_len to 0 and break.
                         */
                        paddrreq = ill->ill_phys_addr_pend;
                        ill_dlpi_done(ill, DL_PHYS_ADDR_REQ);
                        if (paddrreq == DL_IPV6_TOKEN) {
                                ill->ill_token_length = 0;
                                log = B_FALSE;
                                break;
                        } else if (paddrreq == DL_IPV6_LINK_LAYER_ADDR) {
                                ill->ill_nd_lla_len = 0;
                                log = B_FALSE;
                                break;
                        }
                        /*
                         * Something went wrong with the DL_PHYS_ADDR_REQ.
                         * We presumably have an IOCTL hanging out waiting
                         * for completion. Find it and complete the IOCTL
                         * with the error noted.
                         * However, ill_dl_phys was called on an ill queue
                         * (from SIOCSLIFNAME), thus conn_pending_ill is not
                         * set. But the ioctl is known to be pending on ill_wq.
                         */
                        if (!ill->ill_ifname_pending)
                                break;
                        ill->ill_ifname_pending = 0;
                        if (!ioctl_aborted)
                                mp1 = ipsq_pending_mp_get(ipsq, &connp);
                        if (mp1 != NULL) {
                                /*
                                 * This operation (SIOCSLIFNAME) must have
                                 * happened on the ill. Assert there is no conn
                                 */
                                ASSERT(connp == NULL);
                                q = ill->ill_wq;
                        }
                        break;
                case DL_BIND_REQ:
                        ill_dlpi_done(ill, DL_BIND_REQ);
                        if (ill->ill_ifname_pending)
                                break;
                        mutex_enter(&ill->ill_lock);
                        ill->ill_state_flags &= ~ILL_DOWN_IN_PROGRESS;
                        mutex_exit(&ill->ill_lock);
                        /*
                         * Something went wrong with the bind.  We presumably
                         * have an IOCTL hanging out waiting for completion.
                         * Find it, take down the interface that was coming
                         * up, and complete the IOCTL with the error noted.
                         */
                        if (!ioctl_aborted)
                                mp1 = ipsq_pending_mp_get(ipsq, &connp);
                        if (mp1 != NULL) {
                                /*
                                 * This might be a result of a DL_NOTE_REPLUMB
                                 * notification. In that case, connp is NULL.
                                 */
                                if (connp != NULL)
                                        q = CONNP_TO_WQ(connp);

                                (void) ipif_down(ipif, NULL, NULL);
                                /* error is set below the switch */
                        }
                        break;
                case DL_ENABMULTI_REQ:
                        ill_dlpi_done(ill, DL_ENABMULTI_REQ);

                        if (ill->ill_dlpi_multicast_state == IDS_INPROGRESS)
                                ill->ill_dlpi_multicast_state = IDS_FAILED;
                        if (ill->ill_dlpi_multicast_state == IDS_FAILED) {

                                printf("ip: joining multicasts failed (%d)"
                                    " on %s - will use link layer "
                                    "broadcasts for multicast\n",
                                    dlea->dl_errno, ill->ill_name);

                                /*
                                 * Set up for multi_bcast; We are the
                                 * writer, so ok to access ill->ill_ipif
                                 * without any lock.
                                 */
                                mutex_enter(&ill->ill_phyint->phyint_lock);
                                ill->ill_phyint->phyint_flags |=
                                    PHYI_MULTI_BCAST;
                                mutex_exit(&ill->ill_phyint->phyint_lock);

                        }
                        freemsg(mp);    /* Don't want to pass this up */
                        return;
                case DL_CAPABILITY_REQ:
                        ip1dbg(("ip_rput_dlpi_writer: got DL_ERROR_ACK for "
                            "DL_CAPABILITY REQ\n"));
                        if (ill->ill_dlpi_capab_state == IDCS_PROBE_SENT)
                                ill->ill_dlpi_capab_state = IDCS_FAILED;
                        ill_capability_done(ill);
                        freemsg(mp);
                        return;
                }
                /*
                 * Note the error for IOCTL completion (mp1 is set when
                 * ready to complete ioctl). If ill_ifname_pending_err is
                 * set, an error occured during plumbing (ill_ifname_pending),
                 * so we want to report that error.
                 *
                 * NOTE: there are two addtional DL_PHYS_ADDR_REQ's
                 * (DL_IPV6_TOKEN and DL_IPV6_LINK_LAYER_ADDR) that are
                 * expected to get errack'd if the driver doesn't support
                 * these flags (e.g. ethernet). log will be set to B_FALSE
                 * if these error conditions are encountered.
                 */
                if (mp1 != NULL) {
                        if (ill->ill_ifname_pending_err != 0)  {
                                err = ill->ill_ifname_pending_err;
                                ill->ill_ifname_pending_err = 0;
                        } else {
                                err = dlea->dl_unix_errno ?
                                    dlea->dl_unix_errno : ENXIO;
                        }
                /*
                 * If we're plumbing an interface and an error hasn't already
                 * been saved, set ill_ifname_pending_err to the error passed
                 * up. Ignore the error if log is B_FALSE (see comment above).
                 */
                } else if (log && ill->ill_ifname_pending &&
                    ill->ill_ifname_pending_err == 0) {
                        ill->ill_ifname_pending_err = dlea->dl_unix_errno ?
                            dlea->dl_unix_errno : ENXIO;
                }

                if (log)
                        ip_dlpi_error(ill, dlea->dl_error_primitive,
                            dlea->dl_errno, dlea->dl_unix_errno);
                break;
        case DL_CAPABILITY_ACK:
                ill_capability_ack(ill, mp);
                /*
                 * The message has been handed off to ill_capability_ack
                 * and must not be freed below
                 */
                mp = NULL;
                break;

        case DL_INFO_ACK:
                /* Call a routine to handle this one. */
                ill_dlpi_done(ill, DL_INFO_REQ);
                ip_ll_subnet_defaults(ill, mp);
                ASSERT(!MUTEX_HELD(&ill->ill_phyint->phyint_ipsq->ipsq_lock));
                return;
        case DL_BIND_ACK:
                /*
                 * We should have an IOCTL waiting on this unless
                 * sent by ill_dl_phys, in which case just return
                 */
                ill_dlpi_done(ill, DL_BIND_REQ);

                if (ill->ill_ifname_pending) {
                        DTRACE_PROBE2(ip__rput__dlpi__ifname__pending,
                            ill_t *, ill, mblk_t *, mp);
                        break;
                }
                mutex_enter(&ill->ill_lock);
                ill->ill_dl_up = 1;
                ill->ill_state_flags &= ~ILL_DOWN_IN_PROGRESS;
                mutex_exit(&ill->ill_lock);

                if (!ioctl_aborted)
                        mp1 = ipsq_pending_mp_get(ipsq, &connp);
                if (mp1 == NULL) {
                        DTRACE_PROBE1(ip__rput__dlpi__no__mblk, ill_t *, ill);
                        break;
                }
                /*
                 * mp1 was added by ill_dl_up(). if that is a result of
                 * a DL_NOTE_REPLUMB notification, connp could be NULL.
                 */
                if (connp != NULL)
                        q = CONNP_TO_WQ(connp);
                /*
                 * We are exclusive. So nothing can change even after
                 * we get the pending mp.
                 */
                ip1dbg(("ip_rput_dlpi: bind_ack %s\n", ill->ill_name));
                DTRACE_PROBE1(ip__rput__dlpi__bind__ack, ill_t *, ill);
                ill_nic_event_dispatch(ill, 0, NE_UP, NULL, 0);

                /*
                 * Now bring up the resolver; when that is complete, we'll
                 * create IREs.  Note that we intentionally mirror what
                 * ipif_up() would have done, because we got here by way of
                 * ill_dl_up(), which stopped ipif_up()'s processing.
                 */
                if (ill->ill_isv6) {
                        /*
                         * v6 interfaces.
                         * Unlike ARP which has to do another bind
                         * and attach, once we get here we are
                         * done with NDP
                         */
                        (void) ipif_resolver_up(ipif, Res_act_initial);
                        if ((err = ipif_ndp_up(ipif, B_TRUE)) == 0)
                                err = ipif_up_done_v6(ipif);
                } else if (ill->ill_net_type == IRE_IF_RESOLVER) {
                        /*
                         * ARP and other v4 external resolvers.
                         * Leave the pending mblk intact so that
                         * the ioctl completes in ip_rput().
                         */
                        if (connp != NULL)
                                mutex_enter(&connp->conn_lock);
                        mutex_enter(&ill->ill_lock);
                        success = ipsq_pending_mp_add(connp, ipif, q, mp1, 0);
                        mutex_exit(&ill->ill_lock);
                        if (connp != NULL)
                                mutex_exit(&connp->conn_lock);
                        if (success) {
                                err = ipif_resolver_up(ipif, Res_act_initial);
                                if (err == EINPROGRESS) {
                                        freemsg(mp);
                                        return;
                                }
                                mp1 = ipsq_pending_mp_get(ipsq, &connp);
                        } else {
                                /* The conn has started closing */
                                err = EINTR;
                        }
                } else {
                        /*
                         * This one is complete. Reply to pending ioctl.
                         */
                        (void) ipif_resolver_up(ipif, Res_act_initial);
                        err = ipif_up_done(ipif);
                }

                if ((err == 0) && (ill->ill_up_ipifs)) {
                        err = ill_up_ipifs(ill, q, mp1);
                        if (err == EINPROGRESS) {
                                freemsg(mp);
                                return;
                        }
                }

                /*
                 * If we have a moved ipif to bring up, and everything has
                 * succeeded to this point, bring it up on the IPMP ill.
                 * Otherwise, leave it down -- the admin can try to bring it
                 * up by hand if need be.
                 */
                if (ill->ill_move_ipif != NULL) {
                        if (err != 0) {
                                ill->ill_move_ipif = NULL;
                        } else {
                                ipif = ill->ill_move_ipif;
                                ill->ill_move_ipif = NULL;
                                err = ipif_up(ipif, q, mp1);
                                if (err == EINPROGRESS) {
                                        freemsg(mp);
                                        return;
                                }
                        }
                }
                break;

        case DL_NOTIFY_IND: {
                dl_notify_ind_t *notify = (dl_notify_ind_t *)mp->b_rptr;
                uint_t orig_mtu, orig_mc_mtu;

                switch (notify->dl_notification) {
                case DL_NOTE_PHYS_ADDR:
                        err = ill_set_phys_addr(ill, mp);
                        break;

                case DL_NOTE_REPLUMB:
                        /*
                         * Directly return after calling ill_replumb().
                         * Note that we should not free mp as it is reused
                         * in the ill_replumb() function.
                         */
                        err = ill_replumb(ill, mp);
                        return;

                case DL_NOTE_FASTPATH_FLUSH:
                        nce_flush(ill, B_FALSE);
                        break;

                case DL_NOTE_SDU_SIZE:
                case DL_NOTE_SDU_SIZE2:
                        /*
                         * The dce and fragmentation code can cope with
                         * this changing while packets are being sent.
                         * When packets are sent ip_output will discover
                         * a change.
                         *
                         * Change the MTU size of the interface.
                         */
                        mutex_enter(&ill->ill_lock);
                        orig_mtu = ill->ill_mtu;
                        orig_mc_mtu = ill->ill_mc_mtu;
                        switch (notify->dl_notification) {
                        case DL_NOTE_SDU_SIZE:
                                ill->ill_current_frag =
                                    (uint_t)notify->dl_data;
                                ill->ill_mc_mtu = (uint_t)notify->dl_data;
                                break;
                        case DL_NOTE_SDU_SIZE2:
                                ill->ill_current_frag =
                                    (uint_t)notify->dl_data1;
                                ill->ill_mc_mtu = (uint_t)notify->dl_data2;
                                break;
                        }
                        if (ill->ill_current_frag > ill->ill_max_frag)
                                ill->ill_max_frag = ill->ill_current_frag;

                        if (!(ill->ill_flags & ILLF_FIXEDMTU)) {
                                ill->ill_mtu = ill->ill_current_frag;

                                /*
                                 * If ill_user_mtu was set (via
                                 * SIOCSLIFLNKINFO), clamp ill_mtu at it.
                                 */
                                if (ill->ill_user_mtu != 0 &&
                                    ill->ill_user_mtu < ill->ill_mtu)
                                        ill->ill_mtu = ill->ill_user_mtu;

                                if (ill->ill_user_mtu != 0 &&
                                    ill->ill_user_mtu < ill->ill_mc_mtu)
                                        ill->ill_mc_mtu = ill->ill_user_mtu;

                                if (ill->ill_isv6) {
                                        if (ill->ill_mtu < IPV6_MIN_MTU)
                                                ill->ill_mtu = IPV6_MIN_MTU;
                                        if (ill->ill_mc_mtu < IPV6_MIN_MTU)
                                                ill->ill_mc_mtu = IPV6_MIN_MTU;
                                } else {
                                        if (ill->ill_mtu < IP_MIN_MTU)
                                                ill->ill_mtu = IP_MIN_MTU;
                                        if (ill->ill_mc_mtu < IP_MIN_MTU)
                                                ill->ill_mc_mtu = IP_MIN_MTU;
                                }
                        } else if (ill->ill_mc_mtu > ill->ill_mtu) {
                                ill->ill_mc_mtu = ill->ill_mtu;
                        }

                        mutex_exit(&ill->ill_lock);
                        /*
                         * Make sure all dce_generation checks find out
                         * that ill_mtu/ill_mc_mtu has changed.
                         */
                        if (orig_mtu != ill->ill_mtu ||
                            orig_mc_mtu != ill->ill_mc_mtu) {
                                dce_increment_all_generations(ill->ill_isv6,
                                    ill->ill_ipst);
                        }

                        /*
                         * Refresh IPMP meta-interface MTU if necessary.
                         */
                        if (IS_UNDER_IPMP(ill))
                                ipmp_illgrp_refresh_mtu(ill->ill_grp);
                        break;

                case DL_NOTE_LINK_UP:
                case DL_NOTE_LINK_DOWN: {
                        /*
                         * We are writer. ill / phyint / ipsq assocs stable.
                         * The RUNNING flag reflects the state of the link.
                         */
                        phyint_t *phyint = ill->ill_phyint;
                        uint64_t new_phyint_flags;
                        boolean_t changed = B_FALSE;
                        boolean_t went_up;

                        went_up = notify->dl_notification == DL_NOTE_LINK_UP;
                        mutex_enter(&phyint->phyint_lock);

                        new_phyint_flags = went_up ?
                            phyint->phyint_flags | PHYI_RUNNING :
                            phyint->phyint_flags & ~PHYI_RUNNING;

                        if (IS_IPMP(ill)) {
                                new_phyint_flags = went_up ?
                                    new_phyint_flags & ~PHYI_FAILED :
                                    new_phyint_flags | PHYI_FAILED;
                        }

                        if (new_phyint_flags != phyint->phyint_flags) {
                                phyint->phyint_flags = new_phyint_flags;
                                changed = B_TRUE;
                        }
                        mutex_exit(&phyint->phyint_lock);
                        /*
                         * ill_restart_dad handles the DAD restart and routing
                         * socket notification logic.
                         */
                        if (changed) {
                                ill_restart_dad(phyint->phyint_illv4, went_up);
                                ill_restart_dad(phyint->phyint_illv6, went_up);
                        }
                        break;
                }
                case DL_NOTE_PROMISC_ON_PHYS: {
                        phyint_t *phyint = ill->ill_phyint;

                        mutex_enter(&phyint->phyint_lock);
                        phyint->phyint_flags |= PHYI_PROMISC;
                        mutex_exit(&phyint->phyint_lock);
                        break;
                }
                case DL_NOTE_PROMISC_OFF_PHYS: {
                        phyint_t *phyint = ill->ill_phyint;

                        mutex_enter(&phyint->phyint_lock);
                        phyint->phyint_flags &= ~PHYI_PROMISC;
                        mutex_exit(&phyint->phyint_lock);
                        break;
                }
                case DL_NOTE_CAPAB_RENEG:
                        /*
                         * Something changed on the driver side.
                         * It wants us to renegotiate the capabilities
                         * on this ill. One possible cause is the aggregation
                         * interface under us where a port got added or
                         * went away.
                         *
                         * If the capability negotiation is already done
                         * or is in progress, reset the capabilities and
                         * mark the ill's ill_capab_reneg to be B_TRUE,
                         * so that when the ack comes back, we can start
                         * the renegotiation process.
                         *
                         * Note that if ill_capab_reneg is already B_TRUE
                         * (ill_dlpi_capab_state is IDS_UNKNOWN in this case),
                         * the capability resetting request has been sent
                         * and the renegotiation has not been started yet;
                         * nothing needs to be done in this case.
                         */
                        ipsq_current_start(ipsq, ill->ill_ipif, 0);
                        ill_capability_reset(ill, B_TRUE);
                        ipsq_current_finish(ipsq);
                        break;

                case DL_NOTE_ALLOWED_IPS:
                        ill_set_allowed_ips(ill, mp);
                        break;
                default:
                        ip0dbg(("ip_rput_dlpi_writer: unknown notification "
                            "type 0x%x for DL_NOTIFY_IND\n",
                            notify->dl_notification));
                        break;
                }

                /*
                 * As this is an asynchronous operation, we
                 * should not call ill_dlpi_done
                 */
                break;
        }
        case DL_NOTIFY_ACK: {
                dl_notify_ack_t *noteack = (dl_notify_ack_t *)mp->b_rptr;

                if (noteack->dl_notifications & DL_NOTE_LINK_UP)
                        ill->ill_note_link = 1;
                ill_dlpi_done(ill, DL_NOTIFY_REQ);
                break;
        }
        case DL_PHYS_ADDR_ACK: {
                /*
                 * As part of plumbing the interface via SIOCSLIFNAME,
                 * ill_dl_phys() will queue a series of DL_PHYS_ADDR_REQs,
                 * whose answers we receive here.  As each answer is received,
                 * we call ill_dlpi_done() to dispatch the next request as
                 * we're processing the current one.  Once all answers have
                 * been received, we use ipsq_pending_mp_get() to dequeue the
                 * outstanding IOCTL and reply to it.  (Because ill_dl_phys()
                 * is invoked from an ill queue, conn_oper_pending_ill is not
                 * available, but we know the ioctl is pending on ill_wq.)
                 */
                uint_t  paddrlen, paddroff;
                uint8_t *addr;

                paddrreq = ill->ill_phys_addr_pend;
                paddrlen = ((dl_phys_addr_ack_t *)mp->b_rptr)->dl_addr_length;
                paddroff = ((dl_phys_addr_ack_t *)mp->b_rptr)->dl_addr_offset;
                addr = mp->b_rptr + paddroff;

                ill_dlpi_done(ill, DL_PHYS_ADDR_REQ);
                if (paddrreq == DL_IPV6_TOKEN) {
                        /*
                         * bcopy to low-order bits of ill_token
                         *
                         * XXX Temporary hack - currently, all known tokens
                         * are 64 bits, so I'll cheat for the moment.
                         */
                        bcopy(addr, &ill->ill_token.s6_addr32[2], paddrlen);
                        ill->ill_token_length = paddrlen;
                        break;
                } else if (paddrreq == DL_IPV6_LINK_LAYER_ADDR) {
                        ASSERT(ill->ill_nd_lla_mp == NULL);
                        ill_set_ndmp(ill, mp, paddroff, paddrlen);
                        mp = NULL;
                        break;
                } else if (paddrreq == DL_CURR_DEST_ADDR) {
                        ASSERT(ill->ill_dest_addr_mp == NULL);
                        ill->ill_dest_addr_mp = mp;
                        ill->ill_dest_addr = addr;
                        mp = NULL;
                        if (ill->ill_isv6) {
                                ill_setdesttoken(ill);
                                ipif_setdestlinklocal(ill->ill_ipif);
                        }
                        break;
                }

                ASSERT(paddrreq == DL_CURR_PHYS_ADDR);
                ASSERT(ill->ill_phys_addr_mp == NULL);
                if (!ill->ill_ifname_pending)
                        break;
                ill->ill_ifname_pending = 0;
                if (!ioctl_aborted)
                        mp1 = ipsq_pending_mp_get(ipsq, &connp);
                if (mp1 != NULL) {
                        ASSERT(connp == NULL);
                        q = ill->ill_wq;
                }
                /*
                 * If any error acks received during the plumbing sequence,
                 * ill_ifname_pending_err will be set. Break out and send up
                 * the error to the pending ioctl.
                 */
                if (ill->ill_ifname_pending_err != 0) {
                        err = ill->ill_ifname_pending_err;
                        ill->ill_ifname_pending_err = 0;
                        break;
                }

                ill->ill_phys_addr_mp = mp;
                ill->ill_phys_addr = (paddrlen == 0 ? NULL : addr);
                mp = NULL;

                /*
                 * If paddrlen or ill_phys_addr_length is zero, the DLPI
                 * provider doesn't support physical addresses.  We check both
                 * paddrlen and ill_phys_addr_length because sppp (PPP) does
                 * not have physical addresses, but historically adversises a
                 * physical address length of 0 in its DL_INFO_ACK, but 6 in
                 * its DL_PHYS_ADDR_ACK.
                 */
                if (paddrlen == 0 || ill->ill_phys_addr_length == 0) {
                        ill->ill_phys_addr = NULL;
                } else if (paddrlen != ill->ill_phys_addr_length) {
                        ip0dbg(("DL_PHYS_ADDR_ACK: got addrlen %d, expected %d",
                            paddrlen, ill->ill_phys_addr_length));
                        err = EINVAL;
                        break;
                }

                if (ill->ill_nd_lla_mp == NULL) {
                        if ((mp_hw = copyb(ill->ill_phys_addr_mp)) == NULL) {
                                err = ENOMEM;
                                break;
                        }
                        ill_set_ndmp(ill, mp_hw, paddroff, paddrlen);
                }

                if (ill->ill_isv6) {
                        ill_setdefaulttoken(ill);
                        ipif_setlinklocal(ill->ill_ipif);
                }
                break;
        }
        case DL_OK_ACK:
                ip2dbg(("DL_OK_ACK %s (0x%x)\n",
                    dl_primstr((int)dloa->dl_correct_primitive),
                    dloa->dl_correct_primitive));
                DTRACE_PROBE3(ill__dlpi, char *, "ip_rput_dlpi_writer ok",
                    char *, dl_primstr(dloa->dl_correct_primitive),
                    ill_t *, ill);

                switch (dloa->dl_correct_primitive) {
                case DL_ENABMULTI_REQ:
                case DL_DISABMULTI_REQ:
                        ill_dlpi_done(ill, dloa->dl_correct_primitive);
                        break;
                case DL_PROMISCON_REQ:
                case DL_PROMISCOFF_REQ:
                case DL_UNBIND_REQ:
                case DL_ATTACH_REQ:
                        ill_dlpi_done(ill, dloa->dl_correct_primitive);
                        break;
                }
                break;
        default:
                break;
        }

        freemsg(mp);
        if (mp1 == NULL)
                return;

        /*
         * The operation must complete without EINPROGRESS since
         * ipsq_pending_mp_get() has removed the mblk (mp1).  Otherwise,
         * the operation will be stuck forever inside the IPSQ.
         */
        ASSERT(err != EINPROGRESS);

        DTRACE_PROBE4(ipif__ioctl, char *, "ip_rput_dlpi_writer finish",
            int, ipsq->ipsq_xop->ipx_current_ioctl, ill_t *, ill,
            ipif_t *, NULL);

        switch (ipsq->ipsq_xop->ipx_current_ioctl) {
        case 0:
                ipsq_current_finish(ipsq);
                break;

        case SIOCSLIFNAME:
        case IF_UNITSEL: {
                ill_t *ill_other = ILL_OTHER(ill);

                /*
                 * If SIOCSLIFNAME or IF_UNITSEL is about to succeed, and the
                 * ill has a peer which is in an IPMP group, then place ill
                 * into the same group.  One catch: although ifconfig plumbs
                 * the appropriate IPMP meta-interface prior to plumbing this
                 * ill, it is possible for multiple ifconfig applications to
                 * race (or for another application to adjust plumbing), in
                 * which case the IPMP meta-interface we need will be missing.
                 * If so, kick the phyint out of the group.
                 */
                if (err == 0 && ill_other != NULL && IS_UNDER_IPMP(ill_other)) {
                        ipmp_grp_t      *grp = ill->ill_phyint->phyint_grp;
                        ipmp_illgrp_t   *illg;

                        illg = ill->ill_isv6 ? grp->gr_v6 : grp->gr_v4;
                        if (illg == NULL)
                                ipmp_phyint_leave_grp(ill->ill_phyint);
                        else
                                ipmp_ill_join_illgrp(ill, illg);
                }

                if (ipsq->ipsq_xop->ipx_current_ioctl == IF_UNITSEL)
                        ip_ioctl_finish(q, mp1, err, NO_COPYOUT, ipsq);
                else
                        ip_ioctl_finish(q, mp1, err, COPYOUT, ipsq);
                break;
        }
        case SIOCLIFADDIF:
                ip_ioctl_finish(q, mp1, err, COPYOUT, ipsq);
                break;

        default:
                ip_ioctl_finish(q, mp1, err, NO_COPYOUT, ipsq);
                break;
        }
}

/*
 * ip_rput_other is called by ip_rput to handle messages modifying the global
 * state in IP.  If 'ipsq' is non-NULL, caller is writer on it.
 */
/* ARGSUSED */
void
ip_rput_other(ipsq_t *ipsq, queue_t *q, mblk_t *mp, void *dummy_arg)
{
        ill_t           *ill = q->q_ptr;
        struct iocblk   *iocp;

        ip1dbg(("ip_rput_other "));
        if (ipsq != NULL) {
                ASSERT(IAM_WRITER_IPSQ(ipsq));
                ASSERT(ipsq->ipsq_xop ==
                    ill->ill_phyint->phyint_ipsq->ipsq_xop);
        }

        switch (mp->b_datap->db_type) {
        case M_ERROR:
        case M_HANGUP:
                /*
                 * The device has a problem.  We force the ILL down.  It can
                 * be brought up again manually using SIOCSIFFLAGS (via
                 * ifconfig or equivalent).
                 */
                ASSERT(ipsq != NULL);
                if (mp->b_rptr < mp->b_wptr)
                        ill->ill_error = (int)(*mp->b_rptr & 0xFF);
                if (ill->ill_error == 0)
                        ill->ill_error = ENXIO;
                if (!ill_down_start(q, mp))
                        return;
                ipif_all_down_tail(ipsq, q, mp, NULL);
                break;
        case M_IOCNAK: {
                iocp = (struct iocblk *)mp->b_rptr;

                ASSERT(iocp->ioc_cmd == DL_IOC_HDR_INFO);
                /*
                 * If this was the first attempt, turn off the fastpath
                 * probing.
                 */
                mutex_enter(&ill->ill_lock);
                if (ill->ill_dlpi_fastpath_state == IDS_INPROGRESS) {
                        ill->ill_dlpi_fastpath_state = IDS_FAILED;
                        mutex_exit(&ill->ill_lock);
                        /*
                         * don't flush the nce_t entries: we use them
                         * as an index to the ncec itself.
                         */
                        ip1dbg(("ip_rput: DLPI fastpath off on interface %s\n",
                            ill->ill_name));
                } else {
                        mutex_exit(&ill->ill_lock);
                }
                freemsg(mp);
                break;
        }
        default:
                ASSERT(0);
                break;
        }
}

/*
 * Update any source route, record route or timestamp options
 * When it fails it has consumed the message and BUMPed the MIB.
 */
boolean_t
ip_forward_options(mblk_t *mp, ipha_t *ipha, ill_t *dst_ill,
    ip_recv_attr_t *ira)
{
        ipoptp_t        opts;
        uchar_t         *opt;
        uint8_t         optval;
        uint8_t         optlen;
        ipaddr_t        dst;
        ipaddr_t        ifaddr;
        uint32_t        ts;
        timestruc_t     now;
        ip_stack_t      *ipst = ira->ira_ill->ill_ipst;

        ip2dbg(("ip_forward_options\n"));
        dst = ipha->ipha_dst;
        for (optval = ipoptp_first(&opts, ipha);
            optval != IPOPT_EOL;
            optval = ipoptp_next(&opts)) {
                ASSERT((opts.ipoptp_flags & IPOPTP_ERROR) == 0);
                opt = opts.ipoptp_cur;
                optlen = opts.ipoptp_len;
                ip2dbg(("ip_forward_options: opt %d, len %d\n",
                    optval, opts.ipoptp_len));
                switch (optval) {
                        uint32_t off;
                case IPOPT_SSRR:
                case IPOPT_LSRR:
                        /* Check if adminstratively disabled */
                        if (!ipst->ips_ip_forward_src_routed) {
                                BUMP_MIB(dst_ill->ill_ip_mib,
                                    ipIfStatsForwProhibits);
                                ip_drop_input("ICMP_SOURCE_ROUTE_FAILED",
                                    mp, dst_ill);
                                icmp_unreachable(mp, ICMP_SOURCE_ROUTE_FAILED,
                                    ira);
                                return (B_FALSE);
                        }
                        if (ip_type_v4(dst, ipst) != IRE_LOCAL) {
                                /*
                                 * Must be partial since ip_input_options
                                 * checked for strict.
                                 */
                                break;
                        }
                        off = opt[IPOPT_OFFSET];
                        off--;
                redo_srr:
                        if (optlen < IP_ADDR_LEN ||
                            off > optlen - IP_ADDR_LEN) {
                                /* End of source route */
                                ip1dbg((
                                    "ip_forward_options: end of SR\n"));
                                break;
                        }
                        /* Pick a reasonable address on the outbound if */
                        ASSERT(dst_ill != NULL);
                        if (ip_select_source_v4(dst_ill, INADDR_ANY, dst,
                            INADDR_ANY, ALL_ZONES, ipst, &ifaddr, NULL,
                            NULL) != 0) {
                                /* No source! Shouldn't happen */
                                ifaddr = INADDR_ANY;
                        }
                        bcopy((char *)opt + off, &dst, IP_ADDR_LEN);
                        bcopy(&ifaddr, (char *)opt + off, IP_ADDR_LEN);
                        ip1dbg(("ip_forward_options: next hop 0x%x\n",
                            ntohl(dst)));

                        /*
                         * Check if our address is present more than
                         * once as consecutive hops in source route.
                         */
                        if (ip_type_v4(dst, ipst) == IRE_LOCAL) {
                                off += IP_ADDR_LEN;
                                opt[IPOPT_OFFSET] += IP_ADDR_LEN;
                                goto redo_srr;
                        }
                        ipha->ipha_dst = dst;
                        opt[IPOPT_OFFSET] += IP_ADDR_LEN;
                        break;
                case IPOPT_RR:
                        off = opt[IPOPT_OFFSET];
                        off--;
                        if (optlen < IP_ADDR_LEN ||
                            off > optlen - IP_ADDR_LEN) {
                                /* No more room - ignore */
                                ip1dbg((
                                    "ip_forward_options: end of RR\n"));
                                break;
                        }
                        /* Pick a reasonable address on the outbound if */
                        ASSERT(dst_ill != NULL);
                        if (ip_select_source_v4(dst_ill, INADDR_ANY, dst,
                            INADDR_ANY, ALL_ZONES, ipst, &ifaddr, NULL,
                            NULL) != 0) {
                                /* No source! Shouldn't happen */
                                ifaddr = INADDR_ANY;
                        }
                        bcopy(&ifaddr, (char *)opt + off, IP_ADDR_LEN);
                        opt[IPOPT_OFFSET] += IP_ADDR_LEN;
                        break;
                case IPOPT_TS:
                        /* Insert timestamp if there is room */
                        switch (opt[IPOPT_POS_OV_FLG] & 0x0F) {
                        case IPOPT_TS_TSONLY:
                                off = IPOPT_TS_TIMELEN;
                                break;
                        case IPOPT_TS_PRESPEC:
                        case IPOPT_TS_PRESPEC_RFC791:
                                /* Verify that the address matched */
                                off = opt[IPOPT_OFFSET] - 1;
                                bcopy((char *)opt + off, &dst, IP_ADDR_LEN);
                                if (ip_type_v4(dst, ipst) != IRE_LOCAL) {
                                        /* Not for us */
                                        break;
                                }
                                /* FALLTHROUGH */
                        case IPOPT_TS_TSANDADDR:
                                off = IP_ADDR_LEN + IPOPT_TS_TIMELEN;
                                break;
                        default:
                                /*
                                 * ip_*put_options should have already
                                 * dropped this packet.
                                 */
                                cmn_err(CE_PANIC, "ip_forward_options: "
                                    "unknown IT - bug in ip_input_options?\n");
                                return (B_TRUE);        /* Keep "lint" happy */
                        }
                        if (opt[IPOPT_OFFSET] - 1 + off > optlen) {
                                /* Increase overflow counter */
                                off = (opt[IPOPT_POS_OV_FLG] >> 4) + 1;
                                opt[IPOPT_POS_OV_FLG] =
                                    (uint8_t)((opt[IPOPT_POS_OV_FLG] & 0x0F) |
                                    (off << 4));
                                break;
                        }
                        off = opt[IPOPT_OFFSET] - 1;
                        switch (opt[IPOPT_POS_OV_FLG] & 0x0F) {
                        case IPOPT_TS_PRESPEC:
                        case IPOPT_TS_PRESPEC_RFC791:
                        case IPOPT_TS_TSANDADDR:
                                /* Pick a reasonable addr on the outbound if */
                                ASSERT(dst_ill != NULL);
                                if (ip_select_source_v4(dst_ill, INADDR_ANY,
                                    dst, INADDR_ANY, ALL_ZONES, ipst, &ifaddr,
                                    NULL, NULL) != 0) {
                                        /* No source! Shouldn't happen */
                                        ifaddr = INADDR_ANY;
                                }
                                bcopy(&ifaddr, (char *)opt + off, IP_ADDR_LEN);
                                opt[IPOPT_OFFSET] += IP_ADDR_LEN;
                                /* FALLTHROUGH */
                        case IPOPT_TS_TSONLY:
                                off = opt[IPOPT_OFFSET] - 1;
                                /* Compute # of milliseconds since midnight */
                                gethrestime(&now);
                                ts = (now.tv_sec % (24 * 60 * 60)) * 1000 +
                                    NSEC2MSEC(now.tv_nsec);
                                bcopy(&ts, (char *)opt + off, IPOPT_TS_TIMELEN);
                                opt[IPOPT_OFFSET] += IPOPT_TS_TIMELEN;
                                break;
                        }
                        break;
                }
        }
        return (B_TRUE);
}

/*
 * Call ill_frag_timeout to do garbage collection. ill_frag_timeout
 * returns 'true' if there are still fragments left on the queue, in
 * which case we restart the timer.
 */
void
ill_frag_timer(void *arg)
{
        ill_t   *ill = (ill_t *)arg;
        boolean_t frag_pending;
        ip_stack_t *ipst = ill->ill_ipst;
        time_t  timeout;

        mutex_enter(&ill->ill_lock);
        ASSERT(!ill->ill_fragtimer_executing);
        if (ill->ill_state_flags & ILL_CONDEMNED) {
                ill->ill_frag_timer_id = 0;
                mutex_exit(&ill->ill_lock);
                return;
        }
        ill->ill_fragtimer_executing = 1;
        mutex_exit(&ill->ill_lock);

        timeout = (ill->ill_isv6 ? ipst->ips_ipv6_reassembly_timeout :
            ipst->ips_ip_reassembly_timeout);

        frag_pending = ill_frag_timeout(ill, timeout);

        /*
         * Restart the timer, if we have fragments pending or if someone
         * wanted us to be scheduled again.
         */
        mutex_enter(&ill->ill_lock);
        ill->ill_fragtimer_executing = 0;
        ill->ill_frag_timer_id = 0;
        if (frag_pending || ill->ill_fragtimer_needrestart)
                ill_frag_timer_start(ill);
        mutex_exit(&ill->ill_lock);
}

void
ill_frag_timer_start(ill_t *ill)
{
        ip_stack_t *ipst = ill->ill_ipst;
        clock_t timeo_ms;

        ASSERT(MUTEX_HELD(&ill->ill_lock));

        /* If the ill is closing or opening don't proceed */
        if (ill->ill_state_flags & ILL_CONDEMNED)
                return;

        if (ill->ill_fragtimer_executing) {
                /*
                 * ill_frag_timer is currently executing. Just record the
                 * the fact that we want the timer to be restarted.
                 * ill_frag_timer will post a timeout before it returns,
                 * ensuring it will be called again.
                 */
                ill->ill_fragtimer_needrestart = 1;
                return;
        }

        if (ill->ill_frag_timer_id == 0) {
                timeo_ms = (ill->ill_isv6 ? ipst->ips_ipv6_reassembly_timeout :
                    ipst->ips_ip_reassembly_timeout) * SECONDS;

                /*
                 * The timer is neither running nor is the timeout handler
                 * executing. Post a timeout so that ill_frag_timer will be
                 * called
                 */
                ill->ill_frag_timer_id = timeout(ill_frag_timer, ill,
                    MSEC_TO_TICK(timeo_ms >> 1));
                ill->ill_fragtimer_needrestart = 0;
        }
}

/*
 * Update any source route, record route or timestamp options.
 * Check that we are at end of strict source route.
 * The options have already been checked for sanity in ip_input_options().
 */
boolean_t
ip_input_local_options(mblk_t *mp, ipha_t *ipha, ip_recv_attr_t *ira)
{
        ipoptp_t        opts;
        uchar_t         *opt;
        uint8_t         optval;
        uint8_t         optlen;
        ipaddr_t        dst;
        ipaddr_t        ifaddr;
        uint32_t        ts;
        timestruc_t     now;
        ill_t           *ill = ira->ira_ill;
        ip_stack_t      *ipst = ill->ill_ipst;

        ip2dbg(("ip_input_local_options\n"));

        for (optval = ipoptp_first(&opts, ipha);
            optval != IPOPT_EOL;
            optval = ipoptp_next(&opts)) {
                ASSERT((opts.ipoptp_flags & IPOPTP_ERROR) == 0);
                opt = opts.ipoptp_cur;
                optlen = opts.ipoptp_len;
                ip2dbg(("ip_input_local_options: opt %d, len %d\n",
                    optval, optlen));
                switch (optval) {
                        uint32_t off;
                case IPOPT_SSRR:
                case IPOPT_LSRR:
                        off = opt[IPOPT_OFFSET];
                        off--;
                        if (optlen < IP_ADDR_LEN ||
                            off > optlen - IP_ADDR_LEN) {
                                /* End of source route */
                                ip1dbg(("ip_input_local_options: end of SR\n"));
                                break;
                        }
                        /*
                         * This will only happen if two consecutive entries
                         * in the source route contains our address or if
                         * it is a packet with a loose source route which
                         * reaches us before consuming the whole source route
                         */
                        ip1dbg(("ip_input_local_options: not end of SR\n"));
                        if (optval == IPOPT_SSRR) {
                                goto bad_src_route;
                        }
                        /*
                         * Hack: instead of dropping the packet truncate the
                         * source route to what has been used by filling the
                         * rest with IPOPT_NOP.
                         */
                        opt[IPOPT_OLEN] = (uint8_t)off;
                        while (off < optlen) {
                                opt[off++] = IPOPT_NOP;
                        }
                        break;
                case IPOPT_RR:
                        off = opt[IPOPT_OFFSET];
                        off--;
                        if (optlen < IP_ADDR_LEN ||
                            off > optlen - IP_ADDR_LEN) {
                                /* No more room - ignore */
                                ip1dbg((
                                    "ip_input_local_options: end of RR\n"));
                                break;
                        }
                        /* Pick a reasonable address on the outbound if */
                        if (ip_select_source_v4(ill, INADDR_ANY, ipha->ipha_dst,
                            INADDR_ANY, ALL_ZONES, ipst, &ifaddr, NULL,
                            NULL) != 0) {
                                /* No source! Shouldn't happen */
                                ifaddr = INADDR_ANY;
                        }
                        bcopy(&ifaddr, (char *)opt + off, IP_ADDR_LEN);
                        opt[IPOPT_OFFSET] += IP_ADDR_LEN;
                        break;
                case IPOPT_TS:
                        /* Insert timestamp if there is romm */
                        switch (opt[IPOPT_POS_OV_FLG] & 0x0F) {
                        case IPOPT_TS_TSONLY:
                                off = IPOPT_TS_TIMELEN;
                                break;
                        case IPOPT_TS_PRESPEC:
                        case IPOPT_TS_PRESPEC_RFC791:
                                /* Verify that the address matched */
                                off = opt[IPOPT_OFFSET] - 1;
                                bcopy((char *)opt + off, &dst, IP_ADDR_LEN);
                                if (ip_type_v4(dst, ipst) != IRE_LOCAL) {
                                        /* Not for us */
                                        break;
                                }
                                /* FALLTHROUGH */
                        case IPOPT_TS_TSANDADDR:
                                off = IP_ADDR_LEN + IPOPT_TS_TIMELEN;
                                break;
                        default:
                                /*
                                 * ip_*put_options should have already
                                 * dropped this packet.
                                 */
                                cmn_err(CE_PANIC, "ip_input_local_options: "
                                    "unknown IT - bug in ip_input_options?\n");
                                return (B_TRUE);        /* Keep "lint" happy */
                        }
                        if (opt[IPOPT_OFFSET] - 1 + off > optlen) {
                                /* Increase overflow counter */
                                off = (opt[IPOPT_POS_OV_FLG] >> 4) + 1;
                                opt[IPOPT_POS_OV_FLG] =
                                    (uint8_t)((opt[IPOPT_POS_OV_FLG] & 0x0F) |
                                    (off << 4));
                                break;
                        }
                        off = opt[IPOPT_OFFSET] - 1;
                        switch (opt[IPOPT_POS_OV_FLG] & 0x0F) {
                        case IPOPT_TS_PRESPEC:
                        case IPOPT_TS_PRESPEC_RFC791:
                        case IPOPT_TS_TSANDADDR:
                                /* Pick a reasonable addr on the outbound if */
                                if (ip_select_source_v4(ill, INADDR_ANY,
                                    ipha->ipha_dst, INADDR_ANY, ALL_ZONES, ipst,
                                    &ifaddr, NULL, NULL) != 0) {
                                        /* No source! Shouldn't happen */
                                        ifaddr = INADDR_ANY;
                                }
                                bcopy(&ifaddr, (char *)opt + off, IP_ADDR_LEN);
                                opt[IPOPT_OFFSET] += IP_ADDR_LEN;
                                /* FALLTHROUGH */
                        case IPOPT_TS_TSONLY:
                                off = opt[IPOPT_OFFSET] - 1;
                                /* Compute # of milliseconds since midnight */
                                gethrestime(&now);
                                ts = (now.tv_sec % (24 * 60 * 60)) * 1000 +
                                    NSEC2MSEC(now.tv_nsec);
                                bcopy(&ts, (char *)opt + off, IPOPT_TS_TIMELEN);
                                opt[IPOPT_OFFSET] += IPOPT_TS_TIMELEN;
                                break;
                        }
                        break;
                }
        }
        return (B_TRUE);

bad_src_route:
        /* make sure we clear any indication of a hardware checksum */
        DB_CKSUMFLAGS(mp) = 0;
        ip_drop_input("ICMP_SOURCE_ROUTE_FAILED", mp, ill);
        icmp_unreachable(mp, ICMP_SOURCE_ROUTE_FAILED, ira);
        return (B_FALSE);

}

/*
 * Process IP options in an inbound packet.  Always returns the nexthop.
 * Normally this is the passed in nexthop, but if there is an option
 * that effects the nexthop (such as a source route) that will be returned.
 * Sets *errorp if there is an error, in which case an ICMP error has been sent
 * and mp freed.
 */
ipaddr_t
ip_input_options(ipha_t *ipha, ipaddr_t dst, mblk_t *mp,
    ip_recv_attr_t *ira, int *errorp)
{
        ip_stack_t      *ipst = ira->ira_ill->ill_ipst;
        ipoptp_t        opts;
        uchar_t         *opt;
        uint8_t         optval;
        uint8_t         optlen;
        intptr_t        code = 0;
        ire_t           *ire;

        ip2dbg(("ip_input_options\n"));
        *errorp = 0;
        for (optval = ipoptp_first(&opts, ipha);
            optval != IPOPT_EOL;
            optval = ipoptp_next(&opts)) {
                opt = opts.ipoptp_cur;
                optlen = opts.ipoptp_len;
                ip2dbg(("ip_input_options: opt %d, len %d\n",
                    optval, optlen));
                /*
                 * Note: we need to verify the checksum before we
                 * modify anything thus this routine only extracts the next
                 * hop dst from any source route.
                 */
                switch (optval) {
                        uint32_t off;
                case IPOPT_SSRR:
                case IPOPT_LSRR:
                        if (ip_type_v4(dst, ipst) != IRE_LOCAL) {
                                if (optval == IPOPT_SSRR) {
                                        ip1dbg(("ip_input_options: not next"
                                            " strict source route 0x%x\n",
                                            ntohl(dst)));
                                        code = (char *)&ipha->ipha_dst -
                                            (char *)ipha;
                                        goto param_prob; /* RouterReq's */
                                }
                                ip2dbg(("ip_input_options: "
                                    "not next source route 0x%x\n",
                                    ntohl(dst)));
                                break;
                        }

                        if ((opts.ipoptp_flags & IPOPTP_ERROR) != 0) {
                                ip1dbg((
                                    "ip_input_options: bad option offset\n"));
                                code = (char *)&opt[IPOPT_OLEN] -
                                    (char *)ipha;
                                goto param_prob;
                        }
                        off = opt[IPOPT_OFFSET];
                        off--;
                redo_srr:
                        if (optlen < IP_ADDR_LEN ||
                            off > optlen - IP_ADDR_LEN) {
                                /* End of source route */
                                ip1dbg(("ip_input_options: end of SR\n"));
                                break;
                        }
                        bcopy((char *)opt + off, &dst, IP_ADDR_LEN);
                        ip1dbg(("ip_input_options: next hop 0x%x\n",
                            ntohl(dst)));

                        /*
                         * Check if our address is present more than
                         * once as consecutive hops in source route.
                         * XXX verify per-interface ip_forwarding
                         * for source route?
                         */
                        if (ip_type_v4(dst, ipst) == IRE_LOCAL) {
                                off += IP_ADDR_LEN;
                                goto redo_srr;
                        }

                        if (dst == htonl(INADDR_LOOPBACK)) {
                                ip1dbg(("ip_input_options: loopback addr in "
                                    "source route!\n"));
                                goto bad_src_route;
                        }
                        /*
                         * For strict: verify that dst is directly
                         * reachable.
                         */
                        if (optval == IPOPT_SSRR) {
                                ire = ire_ftable_lookup_v4(dst, 0, 0,
                                    IRE_INTERFACE, NULL, ALL_ZONES,
                                    MATCH_IRE_TYPE, 0, ipst, NULL);
                                if (ire == NULL) {
                                        ip1dbg(("ip_input_options: SSRR not "
                                            "directly reachable: 0x%x\n",
                                            ntohl(dst)));
                                        goto bad_src_route;
                                }
                                ire_refrele(ire);
                        }
                        /*
                         * Defer update of the offset and the record route
                         * until the packet is forwarded.
                         */
                        break;
                case IPOPT_RR:
                        if ((opts.ipoptp_flags & IPOPTP_ERROR) != 0) {
                                ip1dbg((
                                    "ip_input_options: bad option offset\n"));
                                code = (char *)&opt[IPOPT_OLEN] -
                                    (char *)ipha;
                                goto param_prob;
                        }
                        break;
                case IPOPT_TS:
                        /*
                         * Verify that length >= 5 and that there is either
                         * room for another timestamp or that the overflow
                         * counter is not maxed out.
                         */
                        code = (char *)&opt[IPOPT_OLEN] - (char *)ipha;
                        if (optlen < IPOPT_MINLEN_IT) {
                                goto param_prob;
                        }
                        if ((opts.ipoptp_flags & IPOPTP_ERROR) != 0) {
                                ip1dbg((
                                    "ip_input_options: bad option offset\n"));
                                code = (char *)&opt[IPOPT_OFFSET] -
                                    (char *)ipha;
                                goto param_prob;
                        }
                        switch (opt[IPOPT_POS_OV_FLG] & 0x0F) {
                        case IPOPT_TS_TSONLY:
                                off = IPOPT_TS_TIMELEN;
                                break;
                        case IPOPT_TS_TSANDADDR:
                        case IPOPT_TS_PRESPEC:
                        case IPOPT_TS_PRESPEC_RFC791:
                                off = IP_ADDR_LEN + IPOPT_TS_TIMELEN;
                                break;
                        default:
                                code = (char *)&opt[IPOPT_POS_OV_FLG] -
                                    (char *)ipha;
                                goto param_prob;
                        }
                        if (opt[IPOPT_OFFSET] - 1 + off > optlen &&
                            (opt[IPOPT_POS_OV_FLG] & 0xF0) == 0xF0) {
                                /*
                                 * No room and the overflow counter is 15
                                 * already.
                                 */
                                goto param_prob;
                        }
                        break;
                }
        }

        if ((opts.ipoptp_flags & IPOPTP_ERROR) == 0) {
                return (dst);
        }

        ip1dbg(("ip_input_options: error processing IP options."));
        code = (char *)&opt[IPOPT_OFFSET] - (char *)ipha;

param_prob:
        /* make sure we clear any indication of a hardware checksum */
        DB_CKSUMFLAGS(mp) = 0;
        ip_drop_input("ICMP_PARAM_PROBLEM", mp, ira->ira_ill);
        icmp_param_problem(mp, (uint8_t)code, ira);
        *errorp = -1;
        return (dst);

bad_src_route:
        /* make sure we clear any indication of a hardware checksum */
        DB_CKSUMFLAGS(mp) = 0;
        ip_drop_input("ICMP_SOURCE_ROUTE_FAILED", mp, ira->ira_ill);
        icmp_unreachable(mp, ICMP_SOURCE_ROUTE_FAILED, ira);
        *errorp = -1;
        return (dst);
}

/*
 * IP & ICMP info in >=14 msg's ...
 *  - ip fixed part (mib2_ip_t)
 *  - icmp fixed part (mib2_icmp_t)
 *  - ipAddrEntryTable (ip 20)          all IPv4 ipifs
 *  - ipRouteEntryTable (ip 21)         all IPv4 IREs
 *  - ipNetToMediaEntryTable (ip 22)    all IPv4 Neighbor Cache entries
 *  - ip multicast membership (ip_member_t)
 *  - ip multicast source filtering (ip_grpsrc_t)
 *  - igmp fixed part (struct igmpstat)
 *  - multicast routing stats (struct mrtstat)
 *  - multicast routing vifs (array of struct vifctl)
 *  - multicast routing routes (array of struct mfcctl)
 *  - ip6 fixed part (mib2_ipv6IfStatsEntry_t)
 *                                      One per ill plus one generic
 *  - icmp6 fixed part (mib2_ipv6IfIcmpEntry_t)
 *                                      One per ill plus one generic
 *  - ipv6RouteEntry                    all IPv6 IREs
 *  - ipv6NetToMediaEntry               all IPv6 Neighbor Cache entries
 *  - ipv6AddrEntry                     all IPv6 ipifs
 *  - ipv6 multicast membership (ipv6_member_t)
 *  - ipv6 multicast source filtering (ipv6_grpsrc_t)
 *
 * NOTE: original mpctl is copied for msg's 2..N, since its ctl part is
 * already filled in by the caller.
 * If legacy_req is true then MIB structures needs to be truncated to their
 * legacy sizes before being returned.
 * Return value of 0 indicates that no messages were sent and caller
 * should free mpctl.
 */
int
ip_snmp_get(queue_t *q, mblk_t *mpctl, int level, boolean_t legacy_req)
{
        ip_stack_t *ipst;
        sctp_stack_t *sctps;

        if (q->q_next != NULL) {
                ipst = ILLQ_TO_IPST(q);
        } else {
                ipst = CONNQ_TO_IPST(q);
        }
        ASSERT(ipst != NULL);
        sctps = ipst->ips_netstack->netstack_sctp;

        if (mpctl == NULL || mpctl->b_cont == NULL) {
                return (0);
        }

        /*
         * For the purposes of the (broken) packet shell use
         * of the level we make sure MIB2_TCP/MIB2_UDP can be used
         * to make TCP and UDP appear first in the list of mib items.
         * TBD: We could expand this and use it in netstat so that
         * the kernel doesn't have to produce large tables (connections,
         * routes, etc) when netstat only wants the statistics or a particular
         * table.
         */
        if (!(level == MIB2_TCP || level == MIB2_UDP)) {
                if ((mpctl = icmp_snmp_get(q, mpctl)) == NULL) {
                        return (1);
                }
        }

        if (level != MIB2_TCP) {
                if ((mpctl = udp_snmp_get(q, mpctl, legacy_req)) == NULL) {
                        return (1);
                }
        }

        if (level != MIB2_UDP) {
                if ((mpctl = tcp_snmp_get(q, mpctl, legacy_req)) == NULL) {
                        return (1);
                }
        }

        if ((mpctl = ip_snmp_get_mib2_ip_traffic_stats(q, mpctl,
            ipst, legacy_req)) == NULL) {
                return (1);
        }

        if ((mpctl = ip_snmp_get_mib2_ip6(q, mpctl, ipst,
            legacy_req)) == NULL) {
                return (1);
        }

        if ((mpctl = ip_snmp_get_mib2_icmp(q, mpctl, ipst)) == NULL) {
                return (1);
        }

        if ((mpctl = ip_snmp_get_mib2_icmp6(q, mpctl, ipst)) == NULL) {
                return (1);
        }

        if ((mpctl = ip_snmp_get_mib2_igmp(q, mpctl, ipst)) == NULL) {
                return (1);
        }

        if ((mpctl = ip_snmp_get_mib2_multi(q, mpctl, ipst)) == NULL) {
                return (1);
        }

        if ((mpctl = ip_snmp_get_mib2_ip_addr(q, mpctl, ipst,
            legacy_req)) == NULL) {
                return (1);
        }

        if ((mpctl = ip_snmp_get_mib2_ip6_addr(q, mpctl, ipst,
            legacy_req)) == NULL) {
                return (1);
        }

        if ((mpctl = ip_snmp_get_mib2_ip_group_mem(q, mpctl, ipst)) == NULL) {
                return (1);
        }

        if ((mpctl = ip_snmp_get_mib2_ip6_group_mem(q, mpctl, ipst)) == NULL) {
                return (1);
        }

        if ((mpctl = ip_snmp_get_mib2_ip_group_src(q, mpctl, ipst)) == NULL) {
                return (1);
        }

        if ((mpctl = ip_snmp_get_mib2_ip6_group_src(q, mpctl, ipst)) == NULL) {
                return (1);
        }

        if ((mpctl = ip_snmp_get_mib2_virt_multi(q, mpctl, ipst)) == NULL) {
                return (1);
        }

        if ((mpctl = ip_snmp_get_mib2_multi_rtable(q, mpctl, ipst)) == NULL) {
                return (1);
        }

        mpctl = ip_snmp_get_mib2_ip_route_media(q, mpctl, level, ipst);
        if (mpctl == NULL)
                return (1);

        mpctl = ip_snmp_get_mib2_ip6_route_media(q, mpctl, level, ipst);
        if (mpctl == NULL)
                return (1);

        if ((mpctl = sctp_snmp_get_mib2(q, mpctl, sctps)) == NULL) {
                return (1);
        }
        if ((mpctl = ip_snmp_get_mib2_ip_dce(q, mpctl, ipst)) == NULL) {
                return (1);
        }
        freemsg(mpctl);
        return (1);
}

/* Get global (legacy) IPv4 statistics */
static mblk_t *
ip_snmp_get_mib2_ip(queue_t *q, mblk_t *mpctl, mib2_ipIfStatsEntry_t *ipmib,
    ip_stack_t *ipst, boolean_t legacy_req)
{
        mib2_ip_t               old_ip_mib;
        struct opthdr           *optp;
        mblk_t                  *mp2ctl;
        mib2_ipAddrEntry_t      mae;

        /*
         * make a copy of the original message
         */
        mp2ctl = copymsg(mpctl);

        /* fixed length IP structure... */
        optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = MIB2_IP;
        optp->name = 0;
        SET_MIB(old_ip_mib.ipForwarding,
            (WE_ARE_FORWARDING(ipst) ? 1 : 2));
        SET_MIB(old_ip_mib.ipDefaultTTL,
            (uint32_t)ipst->ips_ip_def_ttl);
        SET_MIB(old_ip_mib.ipReasmTimeout,
            ipst->ips_ip_reassembly_timeout);
        SET_MIB(old_ip_mib.ipAddrEntrySize,
            (legacy_req) ? LEGACY_MIB_SIZE(&mae, mib2_ipAddrEntry_t) :
            sizeof (mib2_ipAddrEntry_t));
        SET_MIB(old_ip_mib.ipRouteEntrySize,
            sizeof (mib2_ipRouteEntry_t));
        SET_MIB(old_ip_mib.ipNetToMediaEntrySize,
            sizeof (mib2_ipNetToMediaEntry_t));
        SET_MIB(old_ip_mib.ipMemberEntrySize, sizeof (ip_member_t));
        SET_MIB(old_ip_mib.ipGroupSourceEntrySize, sizeof (ip_grpsrc_t));
        SET_MIB(old_ip_mib.ipDestEntrySize, sizeof (dest_cache_entry_t));

        /*
         * Grab the statistics from the new IP MIB
         */
        SET_MIB(old_ip_mib.ipInReceives,
            (uint32_t)ipmib->ipIfStatsHCInReceives);
        SET_MIB(old_ip_mib.ipInHdrErrors, ipmib->ipIfStatsInHdrErrors);
        SET_MIB(old_ip_mib.ipInAddrErrors, ipmib->ipIfStatsInAddrErrors);
        SET_MIB(old_ip_mib.ipForwDatagrams,
            (uint32_t)ipmib->ipIfStatsHCOutForwDatagrams);
        SET_MIB(old_ip_mib.ipInUnknownProtos,
            ipmib->ipIfStatsInUnknownProtos);
        SET_MIB(old_ip_mib.ipInDiscards, ipmib->ipIfStatsInDiscards);
        SET_MIB(old_ip_mib.ipInDelivers,
            (uint32_t)ipmib->ipIfStatsHCInDelivers);
        SET_MIB(old_ip_mib.ipOutRequests,
            (uint32_t)ipmib->ipIfStatsHCOutRequests);
        SET_MIB(old_ip_mib.ipOutDiscards, ipmib->ipIfStatsOutDiscards);
        SET_MIB(old_ip_mib.ipOutNoRoutes, ipmib->ipIfStatsOutNoRoutes);
        SET_MIB(old_ip_mib.ipReasmReqds, ipmib->ipIfStatsReasmReqds);
        SET_MIB(old_ip_mib.ipReasmOKs, ipmib->ipIfStatsReasmOKs);
        SET_MIB(old_ip_mib.ipReasmFails, ipmib->ipIfStatsReasmFails);
        SET_MIB(old_ip_mib.ipFragOKs, ipmib->ipIfStatsOutFragOKs);
        SET_MIB(old_ip_mib.ipFragFails, ipmib->ipIfStatsOutFragFails);
        SET_MIB(old_ip_mib.ipFragCreates, ipmib->ipIfStatsOutFragCreates);

        /* ipRoutingDiscards is not being used */
        SET_MIB(old_ip_mib.ipRoutingDiscards, 0);
        SET_MIB(old_ip_mib.tcpInErrs, ipmib->tcpIfStatsInErrs);
        SET_MIB(old_ip_mib.udpNoPorts, ipmib->udpIfStatsNoPorts);
        SET_MIB(old_ip_mib.ipInCksumErrs, ipmib->ipIfStatsInCksumErrs);
        SET_MIB(old_ip_mib.ipReasmDuplicates,
            ipmib->ipIfStatsReasmDuplicates);
        SET_MIB(old_ip_mib.ipReasmPartDups, ipmib->ipIfStatsReasmPartDups);
        SET_MIB(old_ip_mib.ipForwProhibits, ipmib->ipIfStatsForwProhibits);
        SET_MIB(old_ip_mib.udpInCksumErrs, ipmib->udpIfStatsInCksumErrs);
        SET_MIB(old_ip_mib.udpInOverflows, ipmib->udpIfStatsInOverflows);
        SET_MIB(old_ip_mib.rawipInOverflows,
            ipmib->rawipIfStatsInOverflows);

        SET_MIB(old_ip_mib.ipsecInSucceeded, ipmib->ipsecIfStatsInSucceeded);
        SET_MIB(old_ip_mib.ipsecInFailed, ipmib->ipsecIfStatsInFailed);
        SET_MIB(old_ip_mib.ipInIPv6, ipmib->ipIfStatsInWrongIPVersion);
        SET_MIB(old_ip_mib.ipOutIPv6, ipmib->ipIfStatsOutWrongIPVersion);
        SET_MIB(old_ip_mib.ipOutSwitchIPv6,
            ipmib->ipIfStatsOutSwitchIPVersion);

        if (!snmp_append_data(mpctl->b_cont, (char *)&old_ip_mib,
            (int)sizeof (old_ip_mib))) {
                ip1dbg(("ip_snmp_get_mib2_ip: failed to allocate %u bytes\n",
                    (uint_t)sizeof (old_ip_mib)));
        }

        optp->len = (t_uscalar_t)msgdsize(mpctl->b_cont);
        ip3dbg(("ip_snmp_get_mib2_ip: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mpctl);
        return (mp2ctl);
}

/* Per interface IPv4 statistics */
static mblk_t *
ip_snmp_get_mib2_ip_traffic_stats(queue_t *q, mblk_t *mpctl, ip_stack_t *ipst,
    boolean_t legacy_req)
{
        struct opthdr           *optp;
        mblk_t                  *mp2ctl;
        ill_t                   *ill;
        ill_walk_context_t      ctx;
        mblk_t                  *mp_tail = NULL;
        mib2_ipIfStatsEntry_t   global_ip_mib;
        mib2_ipAddrEntry_t      mae;

        /*
         * Make a copy of the original message
         */
        mp2ctl = copymsg(mpctl);

        optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = MIB2_IP;
        optp->name = MIB2_IP_TRAFFIC_STATS;
        /* Include "unknown interface" ip_mib */
        ipst->ips_ip_mib.ipIfStatsIPVersion = MIB2_INETADDRESSTYPE_ipv4;
        ipst->ips_ip_mib.ipIfStatsIfIndex =
            MIB2_UNKNOWN_INTERFACE; /* Flag to netstat */
        SET_MIB(ipst->ips_ip_mib.ipIfStatsForwarding,
            (ipst->ips_ip_forwarding ? 1 : 2));
        SET_MIB(ipst->ips_ip_mib.ipIfStatsDefaultTTL,
            (uint32_t)ipst->ips_ip_def_ttl);
        SET_MIB(ipst->ips_ip_mib.ipIfStatsEntrySize,
            sizeof (mib2_ipIfStatsEntry_t));
        SET_MIB(ipst->ips_ip_mib.ipIfStatsAddrEntrySize,
            sizeof (mib2_ipAddrEntry_t));
        SET_MIB(ipst->ips_ip_mib.ipIfStatsRouteEntrySize,
            sizeof (mib2_ipRouteEntry_t));
        SET_MIB(ipst->ips_ip_mib.ipIfStatsNetToMediaEntrySize,
            sizeof (mib2_ipNetToMediaEntry_t));
        SET_MIB(ipst->ips_ip_mib.ipIfStatsMemberEntrySize,
            sizeof (ip_member_t));
        SET_MIB(ipst->ips_ip_mib.ipIfStatsGroupSourceEntrySize,
            sizeof (ip_grpsrc_t));

        bcopy(&ipst->ips_ip_mib, &global_ip_mib, sizeof (global_ip_mib));

        if (legacy_req) {
                SET_MIB(global_ip_mib.ipIfStatsAddrEntrySize,
                    LEGACY_MIB_SIZE(&mae, mib2_ipAddrEntry_t));
        }

        if (!snmp_append_data2(mpctl->b_cont, &mp_tail,
            (char *)&global_ip_mib, (int)sizeof (global_ip_mib))) {
                ip1dbg(("ip_snmp_get_mib2_ip_traffic_stats: "
                    "failed to allocate %u bytes\n",
                    (uint_t)sizeof (global_ip_mib)));
        }

        rw_enter(&ipst->ips_ill_g_lock, RW_READER);
        ill = ILL_START_WALK_V4(&ctx, ipst);
        for (; ill != NULL; ill = ill_next(&ctx, ill)) {
                ill->ill_ip_mib->ipIfStatsIfIndex =
                    ill->ill_phyint->phyint_ifindex;
                SET_MIB(ill->ill_ip_mib->ipIfStatsForwarding,
                    (ipst->ips_ip_forwarding ? 1 : 2));
                SET_MIB(ill->ill_ip_mib->ipIfStatsDefaultTTL,
                    (uint32_t)ipst->ips_ip_def_ttl);

                ip_mib2_add_ip_stats(&global_ip_mib, ill->ill_ip_mib);
                if (!snmp_append_data2(mpctl->b_cont, &mp_tail,
                    (char *)ill->ill_ip_mib,
                    (int)sizeof (*ill->ill_ip_mib))) {
                        ip1dbg(("ip_snmp_get_mib2_ip_traffic_stats: "
                            "failed to allocate %u bytes\n",
                            (uint_t)sizeof (*ill->ill_ip_mib)));
                }
        }
        rw_exit(&ipst->ips_ill_g_lock);

        optp->len = (t_uscalar_t)msgdsize(mpctl->b_cont);
        ip3dbg(("ip_snmp_get_mib2_ip_traffic_stats: "
            "level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mpctl);

        if (mp2ctl == NULL)
                return (NULL);

        return (ip_snmp_get_mib2_ip(q, mp2ctl, &global_ip_mib, ipst,
            legacy_req));
}

/* Global IPv4 ICMP statistics */
static mblk_t *
ip_snmp_get_mib2_icmp(queue_t *q, mblk_t *mpctl, ip_stack_t *ipst)
{
        struct opthdr           *optp;
        mblk_t                  *mp2ctl;

        /*
         * Make a copy of the original message
         */
        mp2ctl = copymsg(mpctl);

        optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = MIB2_ICMP;
        optp->name = 0;
        if (!snmp_append_data(mpctl->b_cont, (char *)&ipst->ips_icmp_mib,
            (int)sizeof (ipst->ips_icmp_mib))) {
                ip1dbg(("ip_snmp_get_mib2_icmp: failed to allocate %u bytes\n",
                    (uint_t)sizeof (ipst->ips_icmp_mib)));
        }
        optp->len = (t_uscalar_t)msgdsize(mpctl->b_cont);
        ip3dbg(("ip_snmp_get_mib2_icmp: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mpctl);
        return (mp2ctl);
}

/* Global IPv4 IGMP statistics */
static mblk_t *
ip_snmp_get_mib2_igmp(queue_t *q, mblk_t *mpctl, ip_stack_t *ipst)
{
        struct opthdr           *optp;
        mblk_t                  *mp2ctl;

        /*
         * make a copy of the original message
         */
        mp2ctl = copymsg(mpctl);

        optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = EXPER_IGMP;
        optp->name = 0;
        if (!snmp_append_data(mpctl->b_cont, (char *)&ipst->ips_igmpstat,
            (int)sizeof (ipst->ips_igmpstat))) {
                ip1dbg(("ip_snmp_get_mib2_igmp: failed to allocate %u bytes\n",
                    (uint_t)sizeof (ipst->ips_igmpstat)));
        }
        optp->len = (t_uscalar_t)msgdsize(mpctl->b_cont);
        ip3dbg(("ip_snmp_get_mib2_igmp: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mpctl);
        return (mp2ctl);
}

/* Global IPv4 Multicast Routing statistics */
static mblk_t *
ip_snmp_get_mib2_multi(queue_t *q, mblk_t *mpctl, ip_stack_t *ipst)
{
        struct opthdr           *optp;
        mblk_t                  *mp2ctl;

        /*
         * make a copy of the original message
         */
        mp2ctl = copymsg(mpctl);

        optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = EXPER_DVMRP;
        optp->name = 0;
        if (!ip_mroute_stats(mpctl->b_cont, ipst)) {
                ip0dbg(("ip_mroute_stats: failed\n"));
        }
        optp->len = (t_uscalar_t)msgdsize(mpctl->b_cont);
        ip3dbg(("ip_snmp_get_mib2_multi: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mpctl);
        return (mp2ctl);
}

/* IPv4 address information */
static mblk_t *
ip_snmp_get_mib2_ip_addr(queue_t *q, mblk_t *mpctl, ip_stack_t *ipst,
    boolean_t legacy_req)
{
        struct opthdr           *optp;
        mblk_t                  *mp2ctl;
        mblk_t                  *mp_tail = NULL;
        ill_t                   *ill;
        ipif_t                  *ipif;
        uint_t                  bitval;
        mib2_ipAddrEntry_t      mae;
        size_t                  mae_size;
        zoneid_t                zoneid;
        ill_walk_context_t      ctx;

        /*
         * make a copy of the original message
         */
        mp2ctl = copymsg(mpctl);

        mae_size = (legacy_req) ? LEGACY_MIB_SIZE(&mae, mib2_ipAddrEntry_t) :
            sizeof (mib2_ipAddrEntry_t);

        /* ipAddrEntryTable */

        optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = MIB2_IP;
        optp->name = MIB2_IP_ADDR;
        zoneid = Q_TO_CONN(q)->conn_zoneid;

        rw_enter(&ipst->ips_ill_g_lock, RW_READER);
        ill = ILL_START_WALK_V4(&ctx, ipst);
        for (; ill != NULL; ill = ill_next(&ctx, ill)) {
                for (ipif = ill->ill_ipif; ipif != NULL;
                    ipif = ipif->ipif_next) {
                        if (ipif->ipif_zoneid != zoneid &&
                            ipif->ipif_zoneid != ALL_ZONES)
                                continue;
                        /* Sum of count from dead IRE_LO* and our current */
                        mae.ipAdEntInfo.ae_ibcnt = ipif->ipif_ib_pkt_count;
                        if (ipif->ipif_ire_local != NULL) {
                                mae.ipAdEntInfo.ae_ibcnt +=
                                    ipif->ipif_ire_local->ire_ib_pkt_count;
                        }
                        mae.ipAdEntInfo.ae_obcnt = 0;
                        mae.ipAdEntInfo.ae_focnt = 0;

                        ipif_get_name(ipif, mae.ipAdEntIfIndex.o_bytes,
                            OCTET_LENGTH);
                        mae.ipAdEntIfIndex.o_length =
                            mi_strlen(mae.ipAdEntIfIndex.o_bytes);
                        mae.ipAdEntAddr = ipif->ipif_lcl_addr;
                        mae.ipAdEntNetMask = ipif->ipif_net_mask;
                        mae.ipAdEntInfo.ae_subnet = ipif->ipif_subnet;
                        mae.ipAdEntInfo.ae_subnet_len =
                            ip_mask_to_plen(ipif->ipif_net_mask);
                        mae.ipAdEntInfo.ae_src_addr = ipif->ipif_lcl_addr;
                        for (bitval = 1;
                            bitval &&
                            !(bitval & ipif->ipif_brd_addr);
                            bitval <<= 1)
                                noop;
                        mae.ipAdEntBcastAddr = bitval;
                        mae.ipAdEntReasmMaxSize = IP_MAXPACKET;
                        mae.ipAdEntInfo.ae_mtu = ipif->ipif_ill->ill_mtu;
                        mae.ipAdEntInfo.ae_metric  = ipif->ipif_ill->ill_metric;
                        mae.ipAdEntInfo.ae_broadcast_addr =
                            ipif->ipif_brd_addr;
                        mae.ipAdEntInfo.ae_pp_dst_addr =
                            ipif->ipif_pp_dst_addr;
                        mae.ipAdEntInfo.ae_flags = ipif->ipif_flags |
                            ill->ill_flags | ill->ill_phyint->phyint_flags;
                        mae.ipAdEntRetransmitTime =
                            ill->ill_reachable_retrans_time;

                        if (!snmp_append_data2(mpctl->b_cont, &mp_tail,
                            (char *)&mae, (int)mae_size)) {
                                ip1dbg(("ip_snmp_get_mib2_ip_addr: failed to "
                                    "allocate %u bytes\n", (uint_t)mae_size));
                        }
                }
        }
        rw_exit(&ipst->ips_ill_g_lock);

        optp->len = (t_uscalar_t)msgdsize(mpctl->b_cont);
        ip3dbg(("ip_snmp_get_mib2_ip_addr: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mpctl);
        return (mp2ctl);
}

/* IPv6 address information */
static mblk_t *
ip_snmp_get_mib2_ip6_addr(queue_t *q, mblk_t *mpctl, ip_stack_t *ipst,
    boolean_t legacy_req)
{
        struct opthdr           *optp;
        mblk_t                  *mp2ctl;
        mblk_t                  *mp_tail = NULL;
        ill_t                   *ill;
        ipif_t                  *ipif;
        mib2_ipv6AddrEntry_t    mae6;
        size_t                  mae6_size;
        zoneid_t                zoneid;
        ill_walk_context_t      ctx;

        /*
         * make a copy of the original message
         */
        mp2ctl = copymsg(mpctl);

        mae6_size = (legacy_req) ?
            LEGACY_MIB_SIZE(&mae6, mib2_ipv6AddrEntry_t) :
            sizeof (mib2_ipv6AddrEntry_t);

        /* ipv6AddrEntryTable */

        optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = MIB2_IP6;
        optp->name = MIB2_IP6_ADDR;
        zoneid = Q_TO_CONN(q)->conn_zoneid;

        rw_enter(&ipst->ips_ill_g_lock, RW_READER);
        ill = ILL_START_WALK_V6(&ctx, ipst);
        for (; ill != NULL; ill = ill_next(&ctx, ill)) {
                for (ipif = ill->ill_ipif; ipif != NULL;
                    ipif = ipif->ipif_next) {
                        if (ipif->ipif_zoneid != zoneid &&
                            ipif->ipif_zoneid != ALL_ZONES)
                                continue;
                        /* Sum of count from dead IRE_LO* and our current */
                        mae6.ipv6AddrInfo.ae_ibcnt = ipif->ipif_ib_pkt_count;
                        if (ipif->ipif_ire_local != NULL) {
                                mae6.ipv6AddrInfo.ae_ibcnt +=
                                    ipif->ipif_ire_local->ire_ib_pkt_count;
                        }
                        mae6.ipv6AddrInfo.ae_obcnt = 0;
                        mae6.ipv6AddrInfo.ae_focnt = 0;

                        ipif_get_name(ipif, mae6.ipv6AddrIfIndex.o_bytes,
                            OCTET_LENGTH);
                        mae6.ipv6AddrIfIndex.o_length =
                            mi_strlen(mae6.ipv6AddrIfIndex.o_bytes);
                        mae6.ipv6AddrAddress = ipif->ipif_v6lcl_addr;
                        mae6.ipv6AddrPfxLength =
                            ip_mask_to_plen_v6(&ipif->ipif_v6net_mask);
                        mae6.ipv6AddrInfo.ae_subnet = ipif->ipif_v6subnet;
                        mae6.ipv6AddrInfo.ae_subnet_len =
                            mae6.ipv6AddrPfxLength;
                        mae6.ipv6AddrInfo.ae_src_addr = ipif->ipif_v6lcl_addr;

                        /* Type: stateless(1), stateful(2), unknown(3) */
                        if (ipif->ipif_flags & IPIF_ADDRCONF)
                                mae6.ipv6AddrType = 1;
                        else
                                mae6.ipv6AddrType = 2;
                        /* Anycast: true(1), false(2) */
                        if (ipif->ipif_flags & IPIF_ANYCAST)
                                mae6.ipv6AddrAnycastFlag = 1;
                        else
                                mae6.ipv6AddrAnycastFlag = 2;

                        /*
                         * Address status: preferred(1), deprecated(2),
                         * invalid(3), inaccessible(4), unknown(5)
                         */
                        if (ipif->ipif_flags & IPIF_NOLOCAL)
                                mae6.ipv6AddrStatus = 3;
                        else if (ipif->ipif_flags & IPIF_DEPRECATED)
                                mae6.ipv6AddrStatus = 2;
                        else
                                mae6.ipv6AddrStatus = 1;
                        mae6.ipv6AddrInfo.ae_mtu = ipif->ipif_ill->ill_mtu;
                        mae6.ipv6AddrInfo.ae_metric  =
                            ipif->ipif_ill->ill_metric;
                        mae6.ipv6AddrInfo.ae_pp_dst_addr =
                            ipif->ipif_v6pp_dst_addr;
                        mae6.ipv6AddrInfo.ae_flags = ipif->ipif_flags |
                            ill->ill_flags | ill->ill_phyint->phyint_flags;
                        mae6.ipv6AddrReasmMaxSize = IP_MAXPACKET;
                        mae6.ipv6AddrIdentifier = ill->ill_token;
                        mae6.ipv6AddrIdentifierLen = ill->ill_token_length;
                        mae6.ipv6AddrReachableTime = ill->ill_reachable_time;
                        mae6.ipv6AddrRetransmitTime =
                            ill->ill_reachable_retrans_time;
                        if (!snmp_append_data2(mpctl->b_cont, &mp_tail,
                            (char *)&mae6, (int)mae6_size)) {
                                ip1dbg(("ip_snmp_get_mib2_ip6_addr: failed to "
                                    "allocate %u bytes\n",
                                    (uint_t)mae6_size));
                        }
                }
        }
        rw_exit(&ipst->ips_ill_g_lock);

        optp->len = (t_uscalar_t)msgdsize(mpctl->b_cont);
        ip3dbg(("ip_snmp_get_mib2_ip6_addr: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mpctl);
        return (mp2ctl);
}

/* IPv4 multicast group membership. */
static mblk_t *
ip_snmp_get_mib2_ip_group_mem(queue_t *q, mblk_t *mpctl, ip_stack_t *ipst)
{
        struct opthdr           *optp;
        mblk_t                  *mp2ctl;
        ill_t                   *ill;
        ipif_t                  *ipif;
        ilm_t                   *ilm;
        ip_member_t             ipm;
        mblk_t                  *mp_tail = NULL;
        ill_walk_context_t      ctx;
        zoneid_t                zoneid;

        /*
         * make a copy of the original message
         */
        mp2ctl = copymsg(mpctl);
        zoneid = Q_TO_CONN(q)->conn_zoneid;

        /* ipGroupMember table */
        optp = (struct opthdr *)&mpctl->b_rptr[
            sizeof (struct T_optmgmt_ack)];
        optp->level = MIB2_IP;
        optp->name = EXPER_IP_GROUP_MEMBERSHIP;

        rw_enter(&ipst->ips_ill_g_lock, RW_READER);
        ill = ILL_START_WALK_V4(&ctx, ipst);
        for (; ill != NULL; ill = ill_next(&ctx, ill)) {
                /* Make sure the ill isn't going away. */
                if (!ill_check_and_refhold(ill))
                        continue;
                rw_exit(&ipst->ips_ill_g_lock);
                rw_enter(&ill->ill_mcast_lock, RW_READER);
                for (ilm = ill->ill_ilm; ilm; ilm = ilm->ilm_next) {
                        if (ilm->ilm_zoneid != zoneid &&
                            ilm->ilm_zoneid != ALL_ZONES)
                                continue;

                        /* Is there an ipif for ilm_ifaddr? */
                        for (ipif = ill->ill_ipif; ipif != NULL;
                            ipif = ipif->ipif_next) {
                                if (!IPIF_IS_CONDEMNED(ipif) &&
                                    ipif->ipif_lcl_addr == ilm->ilm_ifaddr &&
                                    ilm->ilm_ifaddr != INADDR_ANY)
                                        break;
                        }
                        if (ipif != NULL) {
                                ipif_get_name(ipif,
                                    ipm.ipGroupMemberIfIndex.o_bytes,
                                    OCTET_LENGTH);
                        } else {
                                ill_get_name(ill,
                                    ipm.ipGroupMemberIfIndex.o_bytes,
                                    OCTET_LENGTH);
                        }
                        ipm.ipGroupMemberIfIndex.o_length =
                            mi_strlen(ipm.ipGroupMemberIfIndex.o_bytes);

                        ipm.ipGroupMemberAddress = ilm->ilm_addr;
                        ipm.ipGroupMemberRefCnt = ilm->ilm_refcnt;
                        ipm.ipGroupMemberFilterMode = ilm->ilm_fmode;
                        if (!snmp_append_data2(mpctl->b_cont, &mp_tail,
                            (char *)&ipm, (int)sizeof (ipm))) {
                                ip1dbg(("ip_snmp_get_mib2_ip_group: "
                                    "failed to allocate %u bytes\n",
                                    (uint_t)sizeof (ipm)));
                        }
                }
                rw_exit(&ill->ill_mcast_lock);
                ill_refrele(ill);
                rw_enter(&ipst->ips_ill_g_lock, RW_READER);
        }
        rw_exit(&ipst->ips_ill_g_lock);
        optp->len = (t_uscalar_t)msgdsize(mpctl->b_cont);
        ip3dbg(("ip_snmp_get: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mpctl);
        return (mp2ctl);
}

/* IPv6 multicast group membership. */
static mblk_t *
ip_snmp_get_mib2_ip6_group_mem(queue_t *q, mblk_t *mpctl, ip_stack_t *ipst)
{
        struct opthdr           *optp;
        mblk_t                  *mp2ctl;
        ill_t                   *ill;
        ilm_t                   *ilm;
        ipv6_member_t           ipm6;
        mblk_t                  *mp_tail = NULL;
        ill_walk_context_t      ctx;
        zoneid_t                zoneid;

        /*
         * make a copy of the original message
         */
        mp2ctl = copymsg(mpctl);
        zoneid = Q_TO_CONN(q)->conn_zoneid;

        /* ip6GroupMember table */
        optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = MIB2_IP6;
        optp->name = EXPER_IP6_GROUP_MEMBERSHIP;

        rw_enter(&ipst->ips_ill_g_lock, RW_READER);
        ill = ILL_START_WALK_V6(&ctx, ipst);
        for (; ill != NULL; ill = ill_next(&ctx, ill)) {
                /* Make sure the ill isn't going away. */
                if (!ill_check_and_refhold(ill))
                        continue;
                rw_exit(&ipst->ips_ill_g_lock);
                /*
                 * Normally we don't have any members on under IPMP interfaces.
                 * We report them as a debugging aid.
                 */
                rw_enter(&ill->ill_mcast_lock, RW_READER);
                ipm6.ipv6GroupMemberIfIndex = ill->ill_phyint->phyint_ifindex;
                for (ilm = ill->ill_ilm; ilm; ilm = ilm->ilm_next) {
                        if (ilm->ilm_zoneid != zoneid &&
                            ilm->ilm_zoneid != ALL_ZONES)
                                continue;       /* not this zone */
                        ipm6.ipv6GroupMemberAddress = ilm->ilm_v6addr;
                        ipm6.ipv6GroupMemberRefCnt = ilm->ilm_refcnt;
                        ipm6.ipv6GroupMemberFilterMode = ilm->ilm_fmode;
                        if (!snmp_append_data2(mpctl->b_cont,
                            &mp_tail,
                            (char *)&ipm6, (int)sizeof (ipm6))) {
                                ip1dbg(("ip_snmp_get_mib2_ip6_group: "
                                    "failed to allocate %u bytes\n",
                                    (uint_t)sizeof (ipm6)));
                        }
                }
                rw_exit(&ill->ill_mcast_lock);
                ill_refrele(ill);
                rw_enter(&ipst->ips_ill_g_lock, RW_READER);
        }
        rw_exit(&ipst->ips_ill_g_lock);

        optp->len = (t_uscalar_t)msgdsize(mpctl->b_cont);
        ip3dbg(("ip_snmp_get: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mpctl);
        return (mp2ctl);
}

/* IP multicast filtered sources */
static mblk_t *
ip_snmp_get_mib2_ip_group_src(queue_t *q, mblk_t *mpctl, ip_stack_t *ipst)
{
        struct opthdr           *optp;
        mblk_t                  *mp2ctl;
        ill_t                   *ill;
        ipif_t                  *ipif;
        ilm_t                   *ilm;
        ip_grpsrc_t             ips;
        mblk_t                  *mp_tail = NULL;
        ill_walk_context_t      ctx;
        zoneid_t                zoneid;
        int                     i;
        slist_t                 *sl;

        /*
         * make a copy of the original message
         */
        mp2ctl = copymsg(mpctl);
        zoneid = Q_TO_CONN(q)->conn_zoneid;

        /* ipGroupSource table */
        optp = (struct opthdr *)&mpctl->b_rptr[
            sizeof (struct T_optmgmt_ack)];
        optp->level = MIB2_IP;
        optp->name = EXPER_IP_GROUP_SOURCES;

        rw_enter(&ipst->ips_ill_g_lock, RW_READER);
        ill = ILL_START_WALK_V4(&ctx, ipst);
        for (; ill != NULL; ill = ill_next(&ctx, ill)) {
                /* Make sure the ill isn't going away. */
                if (!ill_check_and_refhold(ill))
                        continue;
                rw_exit(&ipst->ips_ill_g_lock);
                rw_enter(&ill->ill_mcast_lock, RW_READER);
                for (ilm = ill->ill_ilm; ilm; ilm = ilm->ilm_next) {
                        sl = ilm->ilm_filter;
                        if (ilm->ilm_zoneid != zoneid &&
                            ilm->ilm_zoneid != ALL_ZONES)
                                continue;
                        if (SLIST_IS_EMPTY(sl))
                                continue;

                        /* Is there an ipif for ilm_ifaddr? */
                        for (ipif = ill->ill_ipif; ipif != NULL;
                            ipif = ipif->ipif_next) {
                                if (!IPIF_IS_CONDEMNED(ipif) &&
                                    ipif->ipif_lcl_addr == ilm->ilm_ifaddr &&
                                    ilm->ilm_ifaddr != INADDR_ANY)
                                        break;
                        }
                        if (ipif != NULL) {
                                ipif_get_name(ipif,
                                    ips.ipGroupSourceIfIndex.o_bytes,
                                    OCTET_LENGTH);
                        } else {
                                ill_get_name(ill,
                                    ips.ipGroupSourceIfIndex.o_bytes,
                                    OCTET_LENGTH);
                        }
                        ips.ipGroupSourceIfIndex.o_length =
                            mi_strlen(ips.ipGroupSourceIfIndex.o_bytes);

                        ips.ipGroupSourceGroup = ilm->ilm_addr;
                        for (i = 0; i < sl->sl_numsrc; i++) {
                                if (!IN6_IS_ADDR_V4MAPPED(&sl->sl_addr[i]))
                                        continue;
                                IN6_V4MAPPED_TO_IPADDR(&sl->sl_addr[i],
                                    ips.ipGroupSourceAddress);
                                if (snmp_append_data2(mpctl->b_cont, &mp_tail,
                                    (char *)&ips, (int)sizeof (ips)) == 0) {
                                        ip1dbg(("ip_snmp_get_mib2_ip_group_src:"
                                            " failed to allocate %u bytes\n",
                                            (uint_t)sizeof (ips)));
                                }
                        }
                }
                rw_exit(&ill->ill_mcast_lock);
                ill_refrele(ill);
                rw_enter(&ipst->ips_ill_g_lock, RW_READER);
        }
        rw_exit(&ipst->ips_ill_g_lock);
        optp->len = (t_uscalar_t)msgdsize(mpctl->b_cont);
        ip3dbg(("ip_snmp_get: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mpctl);
        return (mp2ctl);
}

/* IPv6 multicast filtered sources. */
static mblk_t *
ip_snmp_get_mib2_ip6_group_src(queue_t *q, mblk_t *mpctl, ip_stack_t *ipst)
{
        struct opthdr           *optp;
        mblk_t                  *mp2ctl;
        ill_t                   *ill;
        ilm_t                   *ilm;
        ipv6_grpsrc_t           ips6;
        mblk_t                  *mp_tail = NULL;
        ill_walk_context_t      ctx;
        zoneid_t                zoneid;
        int                     i;
        slist_t                 *sl;

        /*
         * make a copy of the original message
         */
        mp2ctl = copymsg(mpctl);
        zoneid = Q_TO_CONN(q)->conn_zoneid;

        /* ip6GroupMember table */
        optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = MIB2_IP6;
        optp->name = EXPER_IP6_GROUP_SOURCES;

        rw_enter(&ipst->ips_ill_g_lock, RW_READER);
        ill = ILL_START_WALK_V6(&ctx, ipst);
        for (; ill != NULL; ill = ill_next(&ctx, ill)) {
                /* Make sure the ill isn't going away. */
                if (!ill_check_and_refhold(ill))
                        continue;
                rw_exit(&ipst->ips_ill_g_lock);
                /*
                 * Normally we don't have any members on under IPMP interfaces.
                 * We report them as a debugging aid.
                 */
                rw_enter(&ill->ill_mcast_lock, RW_READER);
                ips6.ipv6GroupSourceIfIndex = ill->ill_phyint->phyint_ifindex;
                for (ilm = ill->ill_ilm; ilm; ilm = ilm->ilm_next) {
                        sl = ilm->ilm_filter;
                        if (ilm->ilm_zoneid != zoneid &&
                            ilm->ilm_zoneid != ALL_ZONES)
                                continue;
                        if (SLIST_IS_EMPTY(sl))
                                continue;
                        ips6.ipv6GroupSourceGroup = ilm->ilm_v6addr;
                        for (i = 0; i < sl->sl_numsrc; i++) {
                                ips6.ipv6GroupSourceAddress = sl->sl_addr[i];
                                if (!snmp_append_data2(mpctl->b_cont, &mp_tail,
                                    (char *)&ips6, (int)sizeof (ips6))) {
                                        ip1dbg(("ip_snmp_get_mib2_ip6_"
                                            "group_src: failed to allocate "
                                            "%u bytes\n",
                                            (uint_t)sizeof (ips6)));
                                }
                        }
                }
                rw_exit(&ill->ill_mcast_lock);
                ill_refrele(ill);
                rw_enter(&ipst->ips_ill_g_lock, RW_READER);
        }
        rw_exit(&ipst->ips_ill_g_lock);

        optp->len = (t_uscalar_t)msgdsize(mpctl->b_cont);
        ip3dbg(("ip_snmp_get: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mpctl);
        return (mp2ctl);
}

/* Multicast routing virtual interface table. */
static mblk_t *
ip_snmp_get_mib2_virt_multi(queue_t *q, mblk_t *mpctl, ip_stack_t *ipst)
{
        struct opthdr           *optp;
        mblk_t                  *mp2ctl;

        /*
         * make a copy of the original message
         */
        mp2ctl = copymsg(mpctl);

        optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = EXPER_DVMRP;
        optp->name = EXPER_DVMRP_VIF;
        if (!ip_mroute_vif(mpctl->b_cont, ipst)) {
                ip0dbg(("ip_mroute_vif: failed\n"));
        }
        optp->len = (t_uscalar_t)msgdsize(mpctl->b_cont);
        ip3dbg(("ip_snmp_get_mib2_virt_multi: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mpctl);
        return (mp2ctl);
}

/* Multicast routing table. */
static mblk_t *
ip_snmp_get_mib2_multi_rtable(queue_t *q, mblk_t *mpctl, ip_stack_t *ipst)
{
        struct opthdr           *optp;
        mblk_t                  *mp2ctl;

        /*
         * make a copy of the original message
         */
        mp2ctl = copymsg(mpctl);

        optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = EXPER_DVMRP;
        optp->name = EXPER_DVMRP_MRT;
        if (!ip_mroute_mrt(mpctl->b_cont, ipst)) {
                ip0dbg(("ip_mroute_mrt: failed\n"));
        }
        optp->len = (t_uscalar_t)msgdsize(mpctl->b_cont);
        ip3dbg(("ip_snmp_get_mib2_multi_rtable: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mpctl);
        return (mp2ctl);
}

/*
 * Return ipRouteEntryTable and ipNetToMediaEntryTable in one IRE walk.
 */
static mblk_t *
ip_snmp_get_mib2_ip_route_media(queue_t *q, mblk_t *mpctl, int level,
    ip_stack_t *ipst)
{
        struct opthdr   *optp;
        mblk_t          *mp2ctl;        /* Returned */
        mblk_t          *mp3ctl;        /* nettomedia */
        iproutedata_t   ird;
        zoneid_t        zoneid;

        /*
         * make copies of the original message
         *      - mp2ctl is returned unchanged to the caller for its use
         *      - mpctl is sent upstream as ipRouteEntryTable
         *      - mp3ctl is sent upstream as ipNetToMediaEntryTable
         */
        mp2ctl = copymsg(mpctl);
        mp3ctl = copymsg(mpctl);
        if (mp3ctl == NULL) {
                freemsg(mp3ctl);
                freemsg(mp2ctl);
                freemsg(mpctl);
                return (NULL);
        }

        bzero(&ird, sizeof (ird));

        ird.ird_route.lp_head = mpctl->b_cont;
        ird.ird_netmedia.lp_head = mp3ctl->b_cont;
        /*
         * If the level has been set the special EXPER_IP_AND_ALL_IRES value,
         * then also include ire_testhidden IREs and IRE_IF_CLONE.  This is
         * intended a temporary solution until a proper MIB API is provided
         * that provides complete filtering/caller-opt-in.
         */
        if (level == EXPER_IP_AND_ALL_IRES)
                ird.ird_flags |= IRD_REPORT_ALL;

        zoneid = Q_TO_CONN(q)->conn_zoneid;
        ire_walk_v4(ip_snmp_get2_v4, &ird, zoneid, ipst);

        /* ipRouteEntryTable in mpctl */
        optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = MIB2_IP;
        optp->name = MIB2_IP_ROUTE;
        optp->len = msgdsize(ird.ird_route.lp_head);
        ip3dbg(("ip_snmp_get_mib2_ip_route_media: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mpctl);

        /* ipNetToMediaEntryTable in mp3ctl */
        ncec_walk(NULL, ip_snmp_get2_v4_media, &ird, ipst);

        optp = (struct opthdr *)&mp3ctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = MIB2_IP;
        optp->name = MIB2_IP_MEDIA;
        optp->len = msgdsize(ird.ird_netmedia.lp_head);
        ip3dbg(("ip_snmp_get_mib2_ip_route_media: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mp3ctl);

        return (mp2ctl);
}

/*
 * Return ipv6RouteEntryTable in one IRE walk, and ipv6NetToMediaEntryTable in
 * an NDP walk.
 */
static mblk_t *
ip_snmp_get_mib2_ip6_route_media(queue_t *q, mblk_t *mpctl, int level,
    ip_stack_t *ipst)
{
        struct opthdr   *optp;
        mblk_t          *mp2ctl;        /* Returned */
        mblk_t          *mp3ctl;        /* nettomedia */
        iproutedata_t   ird;
        zoneid_t        zoneid;

        /*
         * make copies of the original message
         *      - mp2ctl is returned unchanged to the caller for its use
         *      - mpctl is sent upstream as ipv6RouteEntryTable
         *      - mp3ctl is sent upstream as ipv6NetToMediaEntryTable
         */
        mp2ctl = copymsg(mpctl);
        mp3ctl = copymsg(mpctl);
        if (mp3ctl == NULL) {
                freemsg(mp3ctl);
                freemsg(mp2ctl);
                freemsg(mpctl);
                return (NULL);
        }

        bzero(&ird, sizeof (ird));

        ird.ird_route.lp_head = mpctl->b_cont;
        ird.ird_netmedia.lp_head = mp3ctl->b_cont;
        /*
         * If the level has been set the special EXPER_IP_AND_ALL_IRES value,
         * then also include ire_testhidden IREs and IRE_IF_CLONE.  This is
         * intended a temporary solution until a proper MIB API is provided
         * that provides complete filtering/caller-opt-in.
         */
        if (level == EXPER_IP_AND_ALL_IRES)
                ird.ird_flags |= IRD_REPORT_ALL;

        zoneid = Q_TO_CONN(q)->conn_zoneid;
        ire_walk_v6(ip_snmp_get2_v6_route, &ird, zoneid, ipst);

        optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = MIB2_IP6;
        optp->name = MIB2_IP6_ROUTE;
        optp->len = msgdsize(ird.ird_route.lp_head);
        ip3dbg(("ip_snmp_get_mib2_ip6_route_media: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mpctl);

        /* ipv6NetToMediaEntryTable in mp3ctl */
        ncec_walk(NULL, ip_snmp_get2_v6_media, &ird, ipst);

        optp = (struct opthdr *)&mp3ctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = MIB2_IP6;
        optp->name = MIB2_IP6_MEDIA;
        optp->len = msgdsize(ird.ird_netmedia.lp_head);
        ip3dbg(("ip_snmp_get_mib2_ip6_route_media: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mp3ctl);

        return (mp2ctl);
}

/*
 * IPv6 mib: One per ill
 */
static mblk_t *
ip_snmp_get_mib2_ip6(queue_t *q, mblk_t *mpctl, ip_stack_t *ipst,
    boolean_t legacy_req)
{
        struct opthdr           *optp;
        mblk_t                  *mp2ctl;
        ill_t                   *ill;
        ill_walk_context_t      ctx;
        mblk_t                  *mp_tail = NULL;
        mib2_ipv6AddrEntry_t    mae6;
        mib2_ipIfStatsEntry_t   *ise;
        size_t                  ise_size, iae_size;

        /*
         * Make a copy of the original message
         */
        mp2ctl = copymsg(mpctl);

        /* fixed length IPv6 structure ... */

        if (legacy_req) {
                ise_size = LEGACY_MIB_SIZE(&ipst->ips_ip6_mib,
                    mib2_ipIfStatsEntry_t);
                iae_size = LEGACY_MIB_SIZE(&mae6, mib2_ipv6AddrEntry_t);
        } else {
                ise_size = sizeof (mib2_ipIfStatsEntry_t);
                iae_size = sizeof (mib2_ipv6AddrEntry_t);
        }

        optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = MIB2_IP6;
        optp->name = 0;
        /* Include "unknown interface" ip6_mib */
        ipst->ips_ip6_mib.ipIfStatsIPVersion = MIB2_INETADDRESSTYPE_ipv6;
        ipst->ips_ip6_mib.ipIfStatsIfIndex =
            MIB2_UNKNOWN_INTERFACE; /* Flag to netstat */
        SET_MIB(ipst->ips_ip6_mib.ipIfStatsForwarding,
            ipst->ips_ipv6_forwarding ? 1 : 2);
        SET_MIB(ipst->ips_ip6_mib.ipIfStatsDefaultHopLimit,
            ipst->ips_ipv6_def_hops);
        SET_MIB(ipst->ips_ip6_mib.ipIfStatsEntrySize,
            sizeof (mib2_ipIfStatsEntry_t));
        SET_MIB(ipst->ips_ip6_mib.ipIfStatsAddrEntrySize,
            sizeof (mib2_ipv6AddrEntry_t));
        SET_MIB(ipst->ips_ip6_mib.ipIfStatsRouteEntrySize,
            sizeof (mib2_ipv6RouteEntry_t));
        SET_MIB(ipst->ips_ip6_mib.ipIfStatsNetToMediaEntrySize,
            sizeof (mib2_ipv6NetToMediaEntry_t));
        SET_MIB(ipst->ips_ip6_mib.ipIfStatsMemberEntrySize,
            sizeof (ipv6_member_t));
        SET_MIB(ipst->ips_ip6_mib.ipIfStatsGroupSourceEntrySize,
            sizeof (ipv6_grpsrc_t));

        /*
         * Synchronize 64- and 32-bit counters
         */
        SYNC32_MIB(&ipst->ips_ip6_mib, ipIfStatsInReceives,
            ipIfStatsHCInReceives);
        SYNC32_MIB(&ipst->ips_ip6_mib, ipIfStatsInDelivers,
            ipIfStatsHCInDelivers);
        SYNC32_MIB(&ipst->ips_ip6_mib, ipIfStatsOutRequests,
            ipIfStatsHCOutRequests);
        SYNC32_MIB(&ipst->ips_ip6_mib, ipIfStatsOutForwDatagrams,
            ipIfStatsHCOutForwDatagrams);
        SYNC32_MIB(&ipst->ips_ip6_mib, ipIfStatsOutMcastPkts,
            ipIfStatsHCOutMcastPkts);
        SYNC32_MIB(&ipst->ips_ip6_mib, ipIfStatsInMcastPkts,
            ipIfStatsHCInMcastPkts);

        if (!snmp_append_data2(mpctl->b_cont, &mp_tail,
            (char *)&ipst->ips_ip6_mib, (int)ise_size)) {
                ip1dbg(("ip_snmp_get_mib2_ip6: failed to allocate %u bytes\n",
                    (uint_t)ise_size));
        } else if (legacy_req) {
                /* Adjust the EntrySize fields for legacy requests. */
                ise =
                    (mib2_ipIfStatsEntry_t *)(mp_tail->b_wptr - (int)ise_size);
                SET_MIB(ise->ipIfStatsEntrySize, ise_size);
                SET_MIB(ise->ipIfStatsAddrEntrySize, iae_size);
        }

        rw_enter(&ipst->ips_ill_g_lock, RW_READER);
        ill = ILL_START_WALK_V6(&ctx, ipst);
        for (; ill != NULL; ill = ill_next(&ctx, ill)) {
                ill->ill_ip_mib->ipIfStatsIfIndex =
                    ill->ill_phyint->phyint_ifindex;
                SET_MIB(ill->ill_ip_mib->ipIfStatsForwarding,
                    ipst->ips_ipv6_forwarding ? 1 : 2);
                SET_MIB(ill->ill_ip_mib->ipIfStatsDefaultHopLimit,
                    ill->ill_max_hops);

                /*
                 * Synchronize 64- and 32-bit counters
                 */
                SYNC32_MIB(ill->ill_ip_mib, ipIfStatsInReceives,
                    ipIfStatsHCInReceives);
                SYNC32_MIB(ill->ill_ip_mib, ipIfStatsInDelivers,
                    ipIfStatsHCInDelivers);
                SYNC32_MIB(ill->ill_ip_mib, ipIfStatsOutRequests,
                    ipIfStatsHCOutRequests);
                SYNC32_MIB(ill->ill_ip_mib, ipIfStatsOutForwDatagrams,
                    ipIfStatsHCOutForwDatagrams);
                SYNC32_MIB(ill->ill_ip_mib, ipIfStatsOutMcastPkts,
                    ipIfStatsHCOutMcastPkts);
                SYNC32_MIB(ill->ill_ip_mib, ipIfStatsInMcastPkts,
                    ipIfStatsHCInMcastPkts);

                if (!snmp_append_data2(mpctl->b_cont, &mp_tail,
                    (char *)ill->ill_ip_mib, (int)ise_size)) {
                        ip1dbg(("ip_snmp_get_mib2_ip6: failed to allocate "
                        "%u bytes\n", (uint_t)ise_size));
                } else if (legacy_req) {
                        /* Adjust the EntrySize fields for legacy requests. */
                        ise = (mib2_ipIfStatsEntry_t *)(mp_tail->b_wptr -
                            (int)ise_size);
                        SET_MIB(ise->ipIfStatsEntrySize, ise_size);
                        SET_MIB(ise->ipIfStatsAddrEntrySize, iae_size);
                }
        }
        rw_exit(&ipst->ips_ill_g_lock);

        optp->len = (t_uscalar_t)msgdsize(mpctl->b_cont);
        ip3dbg(("ip_snmp_get_mib2_ip6: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mpctl);
        return (mp2ctl);
}

/*
 * ICMPv6 mib: One per ill
 */
static mblk_t *
ip_snmp_get_mib2_icmp6(queue_t *q, mblk_t *mpctl, ip_stack_t *ipst)
{
        struct opthdr           *optp;
        mblk_t                  *mp2ctl;
        ill_t                   *ill;
        ill_walk_context_t      ctx;
        mblk_t                  *mp_tail = NULL;
        /*
         * Make a copy of the original message
         */
        mp2ctl = copymsg(mpctl);

        /* fixed length ICMPv6 structure ... */

        optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = MIB2_ICMP6;
        optp->name = 0;
        /* Include "unknown interface" icmp6_mib */
        ipst->ips_icmp6_mib.ipv6IfIcmpIfIndex =
            MIB2_UNKNOWN_INTERFACE; /* netstat flag */
        ipst->ips_icmp6_mib.ipv6IfIcmpEntrySize =
            sizeof (mib2_ipv6IfIcmpEntry_t);
        if (!snmp_append_data2(mpctl->b_cont, &mp_tail,
            (char *)&ipst->ips_icmp6_mib,
            (int)sizeof (ipst->ips_icmp6_mib))) {
                ip1dbg(("ip_snmp_get_mib2_icmp6: failed to allocate %u bytes\n",
                    (uint_t)sizeof (ipst->ips_icmp6_mib)));
        }

        rw_enter(&ipst->ips_ill_g_lock, RW_READER);
        ill = ILL_START_WALK_V6(&ctx, ipst);
        for (; ill != NULL; ill = ill_next(&ctx, ill)) {
                ill->ill_icmp6_mib->ipv6IfIcmpIfIndex =
                    ill->ill_phyint->phyint_ifindex;
                if (!snmp_append_data2(mpctl->b_cont, &mp_tail,
                    (char *)ill->ill_icmp6_mib,
                    (int)sizeof (*ill->ill_icmp6_mib))) {
                        ip1dbg(("ip_snmp_get_mib2_icmp6: failed to allocate "
                            "%u bytes\n",
                            (uint_t)sizeof (*ill->ill_icmp6_mib)));
                }
        }
        rw_exit(&ipst->ips_ill_g_lock);

        optp->len = (t_uscalar_t)msgdsize(mpctl->b_cont);
        ip3dbg(("ip_snmp_get_mib2_icmp6: level %d, name %d, len %d\n",
            (int)optp->level, (int)optp->name, (int)optp->len));
        qreply(q, mpctl);
        return (mp2ctl);
}

/*
 * ire_walk routine to create ipRouteEntryTable in one IRE walk
 */
static void
ip_snmp_get2_v4(ire_t *ire, iproutedata_t *ird)
{
        ill_t                           *ill;
        mib2_ipRouteEntry_t             *re;
        ip_stack_t                      *ipst = ire->ire_ipst;

        ASSERT(ire->ire_ipversion == IPV4_VERSION);

        if (!(ird->ird_flags & IRD_REPORT_ALL)) {
                if (ire->ire_testhidden)
                        return;
                if (ire->ire_type & IRE_IF_CLONE)
                        return;
        }

        if ((re = kmem_zalloc(sizeof (*re), KM_NOSLEEP)) == NULL)
                return;

        /*
         * Return all IRE types for route table... let caller pick and choose
         */
        re->ipRouteDest = ire->ire_addr;
        ill = ire->ire_ill;
        re->ipRouteIfIndex.o_length = 0;
        if (ill != NULL) {
                ill_get_name(ill, re->ipRouteIfIndex.o_bytes, OCTET_LENGTH);
                re->ipRouteIfIndex.o_length =
                    mi_strlen(re->ipRouteIfIndex.o_bytes);
        }
        re->ipRouteMetric1 = -1;
        re->ipRouteMetric2 = -1;
        re->ipRouteMetric3 = -1;
        re->ipRouteMetric4 = -1;

        re->ipRouteNextHop = ire->ire_gateway_addr;
        /* indirect(4), direct(3), or invalid(2) */
        if (ire->ire_flags & (RTF_REJECT | RTF_BLACKHOLE))
                re->ipRouteType = 2;
        else if (ire->ire_type & IRE_ONLINK)
                re->ipRouteType = 3;
        else
                re->ipRouteType = 4;

        re->ipRouteProto = -1;
        re->ipRouteAge = gethrestime_sec() - ire->ire_create_time;
        re->ipRouteMask = ire->ire_mask;
        re->ipRouteMetric5 = -1;
        re->ipRouteInfo.re_max_frag = ire->ire_metrics.iulp_mtu;
        if (ire->ire_ill != NULL && re->ipRouteInfo.re_max_frag == 0)
                re->ipRouteInfo.re_max_frag = ire->ire_ill->ill_mtu;

        re->ipRouteInfo.re_frag_flag    = 0;
        re->ipRouteInfo.re_rtt          = 0;
        re->ipRouteInfo.re_src_addr     = 0;
        re->ipRouteInfo.re_ref          = ire->ire_refcnt;
        re->ipRouteInfo.re_obpkt        = ire->ire_ob_pkt_count;
        re->ipRouteInfo.re_ibpkt        = ire->ire_ib_pkt_count;
        re->ipRouteInfo.re_flags        = ire->ire_flags;

        /* Add the IRE_IF_CLONE's counters to their parent IRE_INTERFACE */
        if (ire->ire_type & IRE_INTERFACE) {
                ire_t *child;

                rw_enter(&ipst->ips_ire_dep_lock, RW_READER);
                child = ire->ire_dep_children;
                while (child != NULL) {
                        re->ipRouteInfo.re_obpkt += child->ire_ob_pkt_count;
                        re->ipRouteInfo.re_ibpkt += child->ire_ib_pkt_count;
                        child = child->ire_dep_sib_next;
                }
                rw_exit(&ipst->ips_ire_dep_lock);
        }

        if (ire->ire_flags & RTF_DYNAMIC) {
                re->ipRouteInfo.re_ire_type     = IRE_HOST_REDIRECT;
        } else {
                re->ipRouteInfo.re_ire_type     = ire->ire_type;
        }

        if (!snmp_append_data2(ird->ird_route.lp_head, &ird->ird_route.lp_tail,
            (char *)re, (int)sizeof (*re))) {
                ip1dbg(("ip_snmp_get2_v4: failed to allocate %u bytes\n",
                    (uint_t)sizeof (*re)));
        }

        /* bump route index for next pass */
        ird->ird_idx++;

        kmem_free(re, sizeof (*re));
}

/*
 * ire_walk routine to create ipv6RouteEntryTable and ipRouteEntryTable.
 */
static void
ip_snmp_get2_v6_route(ire_t *ire, iproutedata_t *ird)
{
        ill_t                           *ill;
        mib2_ipv6RouteEntry_t           *re;
        ip_stack_t                      *ipst = ire->ire_ipst;

        ASSERT(ire->ire_ipversion == IPV6_VERSION);

        if (!(ird->ird_flags & IRD_REPORT_ALL)) {
                if (ire->ire_testhidden)
                        return;
                if (ire->ire_type & IRE_IF_CLONE)
                        return;
        }

        if ((re = kmem_zalloc(sizeof (*re), KM_NOSLEEP)) == NULL)
                return;

        /*
         * Return all IRE types for route table... let caller pick and choose
         */
        re->ipv6RouteDest = ire->ire_addr_v6;
        re->ipv6RoutePfxLength = ip_mask_to_plen_v6(&ire->ire_mask_v6);
        re->ipv6RouteIndex = 0; /* Unique when multiple with same dest/plen */
        re->ipv6RouteIfIndex.o_length = 0;
        ill = ire->ire_ill;
        if (ill != NULL) {
                ill_get_name(ill, re->ipv6RouteIfIndex.o_bytes, OCTET_LENGTH);
                re->ipv6RouteIfIndex.o_length =
                    mi_strlen(re->ipv6RouteIfIndex.o_bytes);
        }

        ASSERT(!(ire->ire_type & IRE_BROADCAST));

        mutex_enter(&ire->ire_lock);
        re->ipv6RouteNextHop = ire->ire_gateway_addr_v6;
        mutex_exit(&ire->ire_lock);

        /* remote(4), local(3), or discard(2) */
        if (ire->ire_flags & (RTF_REJECT | RTF_BLACKHOLE))
                re->ipv6RouteType = 2;
        else if (ire->ire_type & IRE_ONLINK)
                re->ipv6RouteType = 3;
        else
                re->ipv6RouteType = 4;

        re->ipv6RouteProtocol   = -1;
        re->ipv6RoutePolicy     = 0;
        re->ipv6RouteAge        = gethrestime_sec() - ire->ire_create_time;
        re->ipv6RouteNextHopRDI = 0;
        re->ipv6RouteWeight     = 0;
        re->ipv6RouteMetric     = 0;
        re->ipv6RouteInfo.re_max_frag = ire->ire_metrics.iulp_mtu;
        if (ire->ire_ill != NULL && re->ipv6RouteInfo.re_max_frag == 0)
                re->ipv6RouteInfo.re_max_frag = ire->ire_ill->ill_mtu;

        re->ipv6RouteInfo.re_frag_flag  = 0;
        re->ipv6RouteInfo.re_rtt        = 0;
        re->ipv6RouteInfo.re_src_addr   = ipv6_all_zeros;
        re->ipv6RouteInfo.re_obpkt      = ire->ire_ob_pkt_count;
        re->ipv6RouteInfo.re_ibpkt      = ire->ire_ib_pkt_count;
        re->ipv6RouteInfo.re_ref        = ire->ire_refcnt;
        re->ipv6RouteInfo.re_flags      = ire->ire_flags;

        /* Add the IRE_IF_CLONE's counters to their parent IRE_INTERFACE */
        if (ire->ire_type & IRE_INTERFACE) {
                ire_t *child;

                rw_enter(&ipst->ips_ire_dep_lock, RW_READER);
                child = ire->ire_dep_children;
                while (child != NULL) {
                        re->ipv6RouteInfo.re_obpkt += child->ire_ob_pkt_count;
                        re->ipv6RouteInfo.re_ibpkt += child->ire_ib_pkt_count;
                        child = child->ire_dep_sib_next;
                }
                rw_exit(&ipst->ips_ire_dep_lock);
        }
        if (ire->ire_flags & RTF_DYNAMIC) {
                re->ipv6RouteInfo.re_ire_type   = IRE_HOST_REDIRECT;
        } else {
                re->ipv6RouteInfo.re_ire_type   = ire->ire_type;
        }

        if (!snmp_append_data2(ird->ird_route.lp_head, &ird->ird_route.lp_tail,
            (char *)re, (int)sizeof (*re))) {
                ip1dbg(("ip_snmp_get2_v6: failed to allocate %u bytes\n",
                    (uint_t)sizeof (*re)));
        }

        /* bump route index for next pass */
        ird->ird_idx++;

        kmem_free(re, sizeof (*re));
}

/*
 * ncec_walk routine to create ipv6NetToMediaEntryTable
 */
static void
ip_snmp_get2_v6_media(ncec_t *ncec, void *ptr)
{
        iproutedata_t *ird              = ptr;
        ill_t                           *ill;
        mib2_ipv6NetToMediaEntry_t      ntme;

        ill = ncec->ncec_ill;
        /* skip arpce entries, and loopback ncec entries */
        if (ill->ill_isv6 == B_FALSE || ill->ill_net_type == IRE_LOOPBACK)
                return;
        /*
         * Neighbor cache entry attached to IRE with on-link
         * destination.
         * We report all IPMP groups on ncec_ill which is normally the upper.
         */
        ntme.ipv6NetToMediaIfIndex = ill->ill_phyint->phyint_ifindex;
        ntme.ipv6NetToMediaNetAddress = ncec->ncec_addr;
        ntme.ipv6NetToMediaPhysAddress.o_length = ill->ill_phys_addr_length;
        if (ncec->ncec_lladdr != NULL) {
                bcopy(ncec->ncec_lladdr, ntme.ipv6NetToMediaPhysAddress.o_bytes,
                    ntme.ipv6NetToMediaPhysAddress.o_length);
        }
        /*
         * Note: Returns ND_* states. Should be:
         * reachable(1), stale(2), delay(3), probe(4),
         * invalid(5), unknown(6)
         */
        ntme.ipv6NetToMediaState = ncec->ncec_state;
        ntme.ipv6NetToMediaLastUpdated = 0;

        /* other(1), dynamic(2), static(3), local(4) */
        if (NCE_MYADDR(ncec)) {
                ntme.ipv6NetToMediaType = 4;
        } else if (ncec->ncec_flags & NCE_F_PUBLISH) {
                ntme.ipv6NetToMediaType = 1; /* proxy */
        } else if (ncec->ncec_flags & NCE_F_STATIC) {
                ntme.ipv6NetToMediaType = 3;
        } else if (ncec->ncec_flags & (NCE_F_MCAST|NCE_F_BCAST)) {
                ntme.ipv6NetToMediaType = 1;
        } else {
                ntme.ipv6NetToMediaType = 2;
        }

        if (!snmp_append_data2(ird->ird_netmedia.lp_head,
            &ird->ird_netmedia.lp_tail, (char *)&ntme, sizeof (ntme))) {
                ip1dbg(("ip_snmp_get2_v6_media: failed to allocate %u bytes\n",
                    (uint_t)sizeof (ntme)));
        }
}

int
nce2ace(ncec_t *ncec)
{
        int flags = 0;

        if (NCE_ISREACHABLE(ncec))
                flags |= ACE_F_RESOLVED;
        if (ncec->ncec_flags & NCE_F_AUTHORITY)
                flags |= ACE_F_AUTHORITY;
        if (ncec->ncec_flags & NCE_F_PUBLISH)
                flags |= ACE_F_PUBLISH;
        if ((ncec->ncec_flags & NCE_F_NONUD) != 0)
                flags |= ACE_F_PERMANENT;
        if (NCE_MYADDR(ncec))
                flags |= (ACE_F_MYADDR | ACE_F_AUTHORITY);
        if (ncec->ncec_flags & NCE_F_UNVERIFIED)
                flags |= ACE_F_UNVERIFIED;
        if (ncec->ncec_flags & NCE_F_AUTHORITY)
                flags |= ACE_F_AUTHORITY;
        if (ncec->ncec_flags & NCE_F_DELAYED)
                flags |= ACE_F_DELAYED;
        return (flags);
}

/*
 * ncec_walk routine to create ipNetToMediaEntryTable
 */
static void
ip_snmp_get2_v4_media(ncec_t *ncec, void *ptr)
{
        iproutedata_t *ird              = ptr;
        ill_t                           *ill;
        mib2_ipNetToMediaEntry_t        ntme;
        const char                      *name = "unknown";
        ipaddr_t                        ncec_addr;

        ill = ncec->ncec_ill;
        if (ill->ill_isv6 || (ncec->ncec_flags & NCE_F_BCAST) ||
            ill->ill_net_type == IRE_LOOPBACK)
                return;

        /* We report all IPMP groups on ncec_ill which is normally the upper. */
        name = ill->ill_name;
        /* Based on RFC 4293: other(1), inval(2), dyn(3), stat(4) */
        if (NCE_MYADDR(ncec)) {
                ntme.ipNetToMediaType = 4;
        } else if (ncec->ncec_flags & (NCE_F_MCAST|NCE_F_BCAST|NCE_F_PUBLISH)) {
                ntme.ipNetToMediaType = 1;
        } else {
                ntme.ipNetToMediaType = 3;
        }
        ntme.ipNetToMediaIfIndex.o_length = MIN(OCTET_LENGTH, strlen(name));
        bcopy(name, ntme.ipNetToMediaIfIndex.o_bytes,
            ntme.ipNetToMediaIfIndex.o_length);

        IN6_V4MAPPED_TO_IPADDR(&ncec->ncec_addr, ncec_addr);
        bcopy(&ncec_addr, &ntme.ipNetToMediaNetAddress, sizeof (ncec_addr));

        ntme.ipNetToMediaInfo.ntm_mask.o_length = sizeof (ipaddr_t);
        ncec_addr = INADDR_BROADCAST;
        bcopy(&ncec_addr, ntme.ipNetToMediaInfo.ntm_mask.o_bytes,
            sizeof (ncec_addr));
        /*
         * map all the flags to the ACE counterpart.
         */
        ntme.ipNetToMediaInfo.ntm_flags = nce2ace(ncec);

        ntme.ipNetToMediaPhysAddress.o_length =
            MIN(OCTET_LENGTH, ill->ill_phys_addr_length);

        if (!NCE_ISREACHABLE(ncec))
                ntme.ipNetToMediaPhysAddress.o_length = 0;
        else {
                if (ncec->ncec_lladdr != NULL) {
                        bcopy(ncec->ncec_lladdr,
                            ntme.ipNetToMediaPhysAddress.o_bytes,
                            ntme.ipNetToMediaPhysAddress.o_length);
                }
        }

        if (!snmp_append_data2(ird->ird_netmedia.lp_head,
            &ird->ird_netmedia.lp_tail, (char *)&ntme, sizeof (ntme))) {
                ip1dbg(("ip_snmp_get2_v4_media: failed to allocate %u bytes\n",
                    (uint_t)sizeof (ntme)));
        }
}

/*
 * return (0) if invalid set request, 1 otherwise, including non-tcp requests
 */
/* ARGSUSED */
int
ip_snmp_set(queue_t *q, int level, int name, uchar_t *ptr, int len)
{
        switch (level) {
        case MIB2_IP:
        case MIB2_ICMP:
                switch (name) {
                default:
                        break;
                }
                return (1);
        default:
                return (1);
        }
}

/*
 * When there exists both a 64- and 32-bit counter of a particular type
 * (i.e., InReceives), only the 64-bit counters are added.
 */
void
ip_mib2_add_ip_stats(mib2_ipIfStatsEntry_t *o1, mib2_ipIfStatsEntry_t *o2)
{
        UPDATE_MIB(o1, ipIfStatsInHdrErrors, o2->ipIfStatsInHdrErrors);
        UPDATE_MIB(o1, ipIfStatsInTooBigErrors, o2->ipIfStatsInTooBigErrors);
        UPDATE_MIB(o1, ipIfStatsInNoRoutes, o2->ipIfStatsInNoRoutes);
        UPDATE_MIB(o1, ipIfStatsInAddrErrors, o2->ipIfStatsInAddrErrors);
        UPDATE_MIB(o1, ipIfStatsInUnknownProtos, o2->ipIfStatsInUnknownProtos);
        UPDATE_MIB(o1, ipIfStatsInTruncatedPkts, o2->ipIfStatsInTruncatedPkts);
        UPDATE_MIB(o1, ipIfStatsInDiscards, o2->ipIfStatsInDiscards);
        UPDATE_MIB(o1, ipIfStatsOutDiscards, o2->ipIfStatsOutDiscards);
        UPDATE_MIB(o1, ipIfStatsOutFragOKs, o2->ipIfStatsOutFragOKs);
        UPDATE_MIB(o1, ipIfStatsOutFragFails, o2->ipIfStatsOutFragFails);
        UPDATE_MIB(o1, ipIfStatsOutFragCreates, o2->ipIfStatsOutFragCreates);
        UPDATE_MIB(o1, ipIfStatsReasmReqds, o2->ipIfStatsReasmReqds);
        UPDATE_MIB(o1, ipIfStatsReasmOKs, o2->ipIfStatsReasmOKs);
        UPDATE_MIB(o1, ipIfStatsReasmFails, o2->ipIfStatsReasmFails);
        UPDATE_MIB(o1, ipIfStatsOutNoRoutes, o2->ipIfStatsOutNoRoutes);
        UPDATE_MIB(o1, ipIfStatsReasmDuplicates, o2->ipIfStatsReasmDuplicates);
        UPDATE_MIB(o1, ipIfStatsReasmPartDups, o2->ipIfStatsReasmPartDups);
        UPDATE_MIB(o1, ipIfStatsForwProhibits, o2->ipIfStatsForwProhibits);
        UPDATE_MIB(o1, udpInCksumErrs, o2->udpInCksumErrs);
        UPDATE_MIB(o1, udpInOverflows, o2->udpInOverflows);
        UPDATE_MIB(o1, rawipInOverflows, o2->rawipInOverflows);
        UPDATE_MIB(o1, ipIfStatsInWrongIPVersion,
            o2->ipIfStatsInWrongIPVersion);
        UPDATE_MIB(o1, ipIfStatsOutWrongIPVersion,
            o2->ipIfStatsInWrongIPVersion);
        UPDATE_MIB(o1, ipIfStatsOutSwitchIPVersion,
            o2->ipIfStatsOutSwitchIPVersion);
        UPDATE_MIB(o1, ipIfStatsHCInReceives, o2->ipIfStatsHCInReceives);
        UPDATE_MIB(o1, ipIfStatsHCInOctets, o2->ipIfStatsHCInOctets);
        UPDATE_MIB(o1, ipIfStatsHCInForwDatagrams,
            o2->ipIfStatsHCInForwDatagrams);
        UPDATE_MIB(o1, ipIfStatsHCInDelivers, o2->ipIfStatsHCInDelivers);
        UPDATE_MIB(o1, ipIfStatsHCOutRequests, o2->ipIfStatsHCOutRequests);
        UPDATE_MIB(o1, ipIfStatsHCOutForwDatagrams,
            o2->ipIfStatsHCOutForwDatagrams);
        UPDATE_MIB(o1, ipIfStatsOutFragReqds, o2->ipIfStatsOutFragReqds);
        UPDATE_MIB(o1, ipIfStatsHCOutTransmits, o2->ipIfStatsHCOutTransmits);
        UPDATE_MIB(o1, ipIfStatsHCOutOctets, o2->ipIfStatsHCOutOctets);
        UPDATE_MIB(o1, ipIfStatsHCInMcastPkts, o2->ipIfStatsHCInMcastPkts);
        UPDATE_MIB(o1, ipIfStatsHCInMcastOctets, o2->ipIfStatsHCInMcastOctets);
        UPDATE_MIB(o1, ipIfStatsHCOutMcastPkts, o2->ipIfStatsHCOutMcastPkts);
        UPDATE_MIB(o1, ipIfStatsHCOutMcastOctets,
            o2->ipIfStatsHCOutMcastOctets);
        UPDATE_MIB(o1, ipIfStatsHCInBcastPkts, o2->ipIfStatsHCInBcastPkts);
        UPDATE_MIB(o1, ipIfStatsHCOutBcastPkts, o2->ipIfStatsHCOutBcastPkts);
        UPDATE_MIB(o1, ipsecInSucceeded, o2->ipsecInSucceeded);
        UPDATE_MIB(o1, ipsecInFailed, o2->ipsecInFailed);
        UPDATE_MIB(o1, ipInCksumErrs, o2->ipInCksumErrs);
        UPDATE_MIB(o1, tcpInErrs, o2->tcpInErrs);
        UPDATE_MIB(o1, udpNoPorts, o2->udpNoPorts);
}

void
ip_mib2_add_icmp6_stats(mib2_ipv6IfIcmpEntry_t *o1, mib2_ipv6IfIcmpEntry_t *o2)
{
        UPDATE_MIB(o1, ipv6IfIcmpInMsgs, o2->ipv6IfIcmpInMsgs);
        UPDATE_MIB(o1, ipv6IfIcmpInErrors, o2->ipv6IfIcmpInErrors);
        UPDATE_MIB(o1, ipv6IfIcmpInDestUnreachs, o2->ipv6IfIcmpInDestUnreachs);
        UPDATE_MIB(o1, ipv6IfIcmpInAdminProhibs, o2->ipv6IfIcmpInAdminProhibs);
        UPDATE_MIB(o1, ipv6IfIcmpInTimeExcds, o2->ipv6IfIcmpInTimeExcds);
        UPDATE_MIB(o1, ipv6IfIcmpInParmProblems, o2->ipv6IfIcmpInParmProblems);
        UPDATE_MIB(o1, ipv6IfIcmpInPktTooBigs, o2->ipv6IfIcmpInPktTooBigs);
        UPDATE_MIB(o1, ipv6IfIcmpInEchos, o2->ipv6IfIcmpInEchos);
        UPDATE_MIB(o1, ipv6IfIcmpInEchoReplies, o2->ipv6IfIcmpInEchoReplies);
        UPDATE_MIB(o1, ipv6IfIcmpInRouterSolicits,
            o2->ipv6IfIcmpInRouterSolicits);
        UPDATE_MIB(o1, ipv6IfIcmpInRouterAdvertisements,
            o2->ipv6IfIcmpInRouterAdvertisements);
        UPDATE_MIB(o1, ipv6IfIcmpInNeighborSolicits,
            o2->ipv6IfIcmpInNeighborSolicits);
        UPDATE_MIB(o1, ipv6IfIcmpInNeighborAdvertisements,
            o2->ipv6IfIcmpInNeighborAdvertisements);
        UPDATE_MIB(o1, ipv6IfIcmpInRedirects, o2->ipv6IfIcmpInRedirects);
        UPDATE_MIB(o1, ipv6IfIcmpInGroupMembQueries,
            o2->ipv6IfIcmpInGroupMembQueries);
        UPDATE_MIB(o1, ipv6IfIcmpInGroupMembResponses,
            o2->ipv6IfIcmpInGroupMembResponses);
        UPDATE_MIB(o1, ipv6IfIcmpInGroupMembReductions,
            o2->ipv6IfIcmpInGroupMembReductions);
        UPDATE_MIB(o1, ipv6IfIcmpOutMsgs, o2->ipv6IfIcmpOutMsgs);
        UPDATE_MIB(o1, ipv6IfIcmpOutErrors, o2->ipv6IfIcmpOutErrors);
        UPDATE_MIB(o1, ipv6IfIcmpOutDestUnreachs,
            o2->ipv6IfIcmpOutDestUnreachs);
        UPDATE_MIB(o1, ipv6IfIcmpOutAdminProhibs,
            o2->ipv6IfIcmpOutAdminProhibs);
        UPDATE_MIB(o1, ipv6IfIcmpOutTimeExcds, o2->ipv6IfIcmpOutTimeExcds);
        UPDATE_MIB(o1, ipv6IfIcmpOutParmProblems,
            o2->ipv6IfIcmpOutParmProblems);
        UPDATE_MIB(o1, ipv6IfIcmpOutPktTooBigs, o2->ipv6IfIcmpOutPktTooBigs);
        UPDATE_MIB(o1, ipv6IfIcmpOutEchos, o2->ipv6IfIcmpOutEchos);
        UPDATE_MIB(o1, ipv6IfIcmpOutEchoReplies, o2->ipv6IfIcmpOutEchoReplies);
        UPDATE_MIB(o1, ipv6IfIcmpOutRouterSolicits,
            o2->ipv6IfIcmpOutRouterSolicits);
        UPDATE_MIB(o1, ipv6IfIcmpOutRouterAdvertisements,
            o2->ipv6IfIcmpOutRouterAdvertisements);
        UPDATE_MIB(o1, ipv6IfIcmpOutNeighborSolicits,
            o2->ipv6IfIcmpOutNeighborSolicits);
        UPDATE_MIB(o1, ipv6IfIcmpOutNeighborAdvertisements,
            o2->ipv6IfIcmpOutNeighborAdvertisements);
        UPDATE_MIB(o1, ipv6IfIcmpOutRedirects, o2->ipv6IfIcmpOutRedirects);
        UPDATE_MIB(o1, ipv6IfIcmpOutGroupMembQueries,
            o2->ipv6IfIcmpOutGroupMembQueries);
        UPDATE_MIB(o1, ipv6IfIcmpOutGroupMembResponses,
            o2->ipv6IfIcmpOutGroupMembResponses);
        UPDATE_MIB(o1, ipv6IfIcmpOutGroupMembReductions,
            o2->ipv6IfIcmpOutGroupMembReductions);
        UPDATE_MIB(o1, ipv6IfIcmpInOverflows, o2->ipv6IfIcmpInOverflows);
        UPDATE_MIB(o1, ipv6IfIcmpBadHoplimit, o2->ipv6IfIcmpBadHoplimit);
        UPDATE_MIB(o1, ipv6IfIcmpInBadNeighborAdvertisements,
            o2->ipv6IfIcmpInBadNeighborAdvertisements);
        UPDATE_MIB(o1, ipv6IfIcmpInBadNeighborSolicitations,
            o2->ipv6IfIcmpInBadNeighborSolicitations);
        UPDATE_MIB(o1, ipv6IfIcmpInBadRedirects, o2->ipv6IfIcmpInBadRedirects);
        UPDATE_MIB(o1, ipv6IfIcmpInGroupMembTotal,
            o2->ipv6IfIcmpInGroupMembTotal);
        UPDATE_MIB(o1, ipv6IfIcmpInGroupMembBadQueries,
            o2->ipv6IfIcmpInGroupMembBadQueries);
        UPDATE_MIB(o1, ipv6IfIcmpInGroupMembBadReports,
            o2->ipv6IfIcmpInGroupMembBadReports);
        UPDATE_MIB(o1, ipv6IfIcmpInGroupMembOurReports,
            o2->ipv6IfIcmpInGroupMembOurReports);
}

/*
 * Called before the options are updated to check if this packet will
 * be source routed from here.
 * This routine assumes that the options are well formed i.e. that they
 * have already been checked.
 */
boolean_t
ip_source_routed(ipha_t *ipha, ip_stack_t *ipst)
{
        ipoptp_t        opts;
        uchar_t         *opt;
        uint8_t         optval;
        uint8_t         optlen;
        ipaddr_t        dst;

        if (IS_SIMPLE_IPH(ipha)) {
                ip2dbg(("not source routed\n"));
                return (B_FALSE);
        }
        dst = ipha->ipha_dst;
        for (optval = ipoptp_first(&opts, ipha);
            optval != IPOPT_EOL;
            optval = ipoptp_next(&opts)) {
                ASSERT((opts.ipoptp_flags & IPOPTP_ERROR) == 0);
                opt = opts.ipoptp_cur;
                optlen = opts.ipoptp_len;
                ip2dbg(("ip_source_routed: opt %d, len %d\n",
                    optval, optlen));
                switch (optval) {
                        uint32_t off;
                case IPOPT_SSRR:
                case IPOPT_LSRR:
                        /*
                         * If dst is one of our addresses and there are some
                         * entries left in the source route return (true).
                         */
                        if (ip_type_v4(dst, ipst) != IRE_LOCAL) {
                                ip2dbg(("ip_source_routed: not next"
                                    " source route 0x%x\n",
                                    ntohl(dst)));
                                return (B_FALSE);
                        }
                        off = opt[IPOPT_OFFSET];
                        off--;
                        if (optlen < IP_ADDR_LEN ||
                            off > optlen - IP_ADDR_LEN) {
                                /* End of source route */
                                ip1dbg(("ip_source_routed: end of SR\n"));
                                return (B_FALSE);
                        }
                        return (B_TRUE);
                }
        }
        ip2dbg(("not source routed\n"));
        return (B_FALSE);
}

/*
 * ip_unbind is called by the transports to remove a conn from
 * the fanout table.
 */
void
ip_unbind(conn_t *connp)
{

        ASSERT(!MUTEX_HELD(&connp->conn_lock));

        ipcl_hash_remove(connp);
}

/*
 * Used for deciding the MSS size for the upper layer. Thus
 * we need to check the outbound policy values in the conn.
 */
int
conn_ipsec_length(conn_t *connp)
{
        ipsec_latch_t *ipl;

        ipl = connp->conn_latch;
        if (ipl == NULL)
                return (0);

        if (connp->conn_ixa->ixa_ipsec_policy == NULL)
                return (0);

        return (connp->conn_ixa->ixa_ipsec_policy->ipsp_act->ipa_ovhd);
}

/*
 * Returns an estimate of the IPsec headers size. This is used if
 * we don't want to call into IPsec to get the exact size.
 */
int
ipsec_out_extra_length(ip_xmit_attr_t *ixa)
{
        ipsec_action_t *a;

        if (!(ixa->ixa_flags & IXAF_IPSEC_SECURE))
                return (0);

        a = ixa->ixa_ipsec_action;
        if (a == NULL) {
                ASSERT(ixa->ixa_ipsec_policy != NULL);
                a = ixa->ixa_ipsec_policy->ipsp_act;
        }
        ASSERT(a != NULL);

        return (a->ipa_ovhd);
}

/*
 * If there are any source route options, return the true final
 * destination. Otherwise, return the destination.
 */
ipaddr_t
ip_get_dst(ipha_t *ipha)
{
        ipoptp_t        opts;
        uchar_t         *opt;
        uint8_t         optval;
        uint8_t         optlen;
        ipaddr_t        dst;
        uint32_t off;

        dst = ipha->ipha_dst;

        if (IS_SIMPLE_IPH(ipha))
                return (dst);

        for (optval = ipoptp_first(&opts, ipha);
            optval != IPOPT_EOL;
            optval = ipoptp_next(&opts)) {
                opt = opts.ipoptp_cur;
                optlen = opts.ipoptp_len;
                ASSERT((opts.ipoptp_flags & IPOPTP_ERROR) == 0);
                switch (optval) {
                case IPOPT_SSRR:
                case IPOPT_LSRR:
                        off = opt[IPOPT_OFFSET];
                        /*
                         * If one of the conditions is true, it means
                         * end of options and dst already has the right
                         * value.
                         */
                        if (!(optlen < IP_ADDR_LEN || off > optlen - 3)) {
                                off = optlen - IP_ADDR_LEN;
                                bcopy(&opt[off], &dst, IP_ADDR_LEN);
                        }
                        return (dst);
                default:
                        break;
                }
        }

        return (dst);
}

/*
 * Outbound IP fragmentation routine.
 * Assumes the caller has checked whether or not fragmentation should
 * be allowed. Here we copy the DF bit from the header to all the generated
 * fragments.
 */
int
ip_fragment_v4(mblk_t *mp_orig, nce_t *nce, iaflags_t ixaflags,
    uint_t pkt_len, uint32_t max_frag, uint32_t xmit_hint, zoneid_t szone,
    zoneid_t nolzid, pfirepostfrag_t postfragfn, uintptr_t *ixa_cookie)
{
        int             i1;
        int             hdr_len;
        mblk_t          *hdr_mp;
        ipha_t          *ipha;
        int             ip_data_end;
        int             len;
        mblk_t          *mp = mp_orig;
        int             offset;
        ill_t           *ill = nce->nce_ill;
        ip_stack_t      *ipst = ill->ill_ipst;
        mblk_t          *carve_mp;
        uint32_t        frag_flag;
        uint_t          priority = mp->b_band;
        int             error = 0;

        BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutFragReqds);

        if (pkt_len != msgdsize(mp)) {
                ip0dbg(("Packet length mismatch: %d, %ld\n",
                    pkt_len, msgdsize(mp)));
                freemsg(mp);
                return (EINVAL);
        }

        if (max_frag == 0) {
                ip1dbg(("ip_fragment_v4: max_frag is zero. Dropping packet\n"));
                BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutFragFails);
                ip_drop_output("FragFails: zero max_frag", mp, ill);
                freemsg(mp);
                return (EINVAL);
        }

        ASSERT(MBLKL(mp) >= sizeof (ipha_t));
        ipha = (ipha_t *)mp->b_rptr;
        ASSERT(ntohs(ipha->ipha_length) == pkt_len);
        frag_flag = ntohs(ipha->ipha_fragment_offset_and_flags) & IPH_DF;

        /*
         * Establish the starting offset.  May not be zero if we are fragging
         * a fragment that is being forwarded.
         */
        offset = ntohs(ipha->ipha_fragment_offset_and_flags) & IPH_OFFSET;

        /* TODO why is this test needed? */
        if (((max_frag - ntohs(ipha->ipha_length)) & ~7) < 8) {
                /* TODO: notify ulp somehow */
                BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutFragFails);
                ip_drop_output("FragFails: bad starting offset", mp, ill);
                freemsg(mp);
                return (EINVAL);
        }

        hdr_len = IPH_HDR_LENGTH(ipha);
        ipha->ipha_hdr_checksum = 0;

        /*
         * Establish the number of bytes maximum per frag, after putting
         * in the header.
         */
        len = (max_frag - hdr_len) & ~7;

        /* Get a copy of the header for the trailing frags */
        hdr_mp = ip_fragment_copyhdr((uchar_t *)ipha, hdr_len, offset, ipst,
            mp);
        if (hdr_mp == NULL) {
                BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutFragFails);
                ip_drop_output("FragFails: no hdr_mp", mp, ill);
                freemsg(mp);
                return (ENOBUFS);
        }

        /* Store the starting offset, with the MoreFrags flag. */
        i1 = offset | IPH_MF | frag_flag;
        ipha->ipha_fragment_offset_and_flags = htons((uint16_t)i1);

        /* Establish the ending byte offset, based on the starting offset. */
        offset <<= 3;
        ip_data_end = offset + ntohs(ipha->ipha_length) - hdr_len;

        /* Store the length of the first fragment in the IP header. */
        i1 = len + hdr_len;
        ASSERT(i1 <= IP_MAXPACKET);
        ipha->ipha_length = htons((uint16_t)i1);

        /*
         * Compute the IP header checksum for the first frag.  We have to
         * watch out that we stop at the end of the header.
         */
        ipha->ipha_hdr_checksum = ip_csum_hdr(ipha);

        /*
         * Now carve off the first frag.  Note that this will include the
         * original IP header.
         */
        if (!(mp = ip_carve_mp(&mp_orig, i1))) {
                BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutFragFails);
                ip_drop_output("FragFails: could not carve mp", mp_orig, ill);
                freeb(hdr_mp);
                freemsg(mp_orig);
                return (ENOBUFS);
        }

        BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutFragCreates);

        error = postfragfn(mp, nce, ixaflags, i1, xmit_hint, szone, nolzid,
            ixa_cookie);
        if (error != 0 && error != EWOULDBLOCK) {
                /* No point in sending the other fragments */
                BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutFragFails);
                ip_drop_output("FragFails: postfragfn failed", mp_orig, ill);
                freeb(hdr_mp);
                freemsg(mp_orig);
                return (error);
        }

        /* No need to redo state machine in loop */
        ixaflags &= ~IXAF_REACH_CONF;

        /* Advance the offset to the second frag starting point. */
        offset += len;
        /*
         * Update hdr_len from the copied header - there might be less options
         * in the later fragments.
         */
        hdr_len = IPH_HDR_LENGTH(hdr_mp->b_rptr);
        /* Loop until done. */
        for (;;) {
                uint16_t        offset_and_flags;
                uint16_t        ip_len;

                if (ip_data_end - offset > len) {
                        /*
                         * Carve off the appropriate amount from the original
                         * datagram.
                         */
                        if (!(carve_mp = ip_carve_mp(&mp_orig, len))) {
                                mp = NULL;
                                break;
                        }
                        /*
                         * More frags after this one.  Get another copy
                         * of the header.
                         */
                        if (carve_mp->b_datap->db_ref == 1 &&
                            hdr_mp->b_wptr - hdr_mp->b_rptr <
                            carve_mp->b_rptr - carve_mp->b_datap->db_base) {
                                /* Inline IP header */
                                carve_mp->b_rptr -= hdr_mp->b_wptr -
                                    hdr_mp->b_rptr;
                                bcopy(hdr_mp->b_rptr, carve_mp->b_rptr,
                                    hdr_mp->b_wptr - hdr_mp->b_rptr);
                                mp = carve_mp;
                        } else {
                                if (!(mp = copyb(hdr_mp))) {
                                        freemsg(carve_mp);
                                        break;
                                }
                                /* Get priority marking, if any. */
                                mp->b_band = priority;
                                mp->b_cont = carve_mp;
                        }
                        ipha = (ipha_t *)mp->b_rptr;
                        offset_and_flags = IPH_MF;
                } else {
                        /*
                         * Last frag.  Consume the header. Set len to
                         * the length of this last piece.
                         */
                        len = ip_data_end - offset;

                        /*
                         * Carve off the appropriate amount from the original
                         * datagram.
                         */
                        if (!(carve_mp = ip_carve_mp(&mp_orig, len))) {
                                mp = NULL;
                                break;
                        }
                        if (carve_mp->b_datap->db_ref == 1 &&
                            hdr_mp->b_wptr - hdr_mp->b_rptr <
                            carve_mp->b_rptr - carve_mp->b_datap->db_base) {
                                /* Inline IP header */
                                carve_mp->b_rptr -= hdr_mp->b_wptr -
                                    hdr_mp->b_rptr;
                                bcopy(hdr_mp->b_rptr, carve_mp->b_rptr,
                                    hdr_mp->b_wptr - hdr_mp->b_rptr);
                                mp = carve_mp;
                                freeb(hdr_mp);
                                hdr_mp = mp;
                        } else {
                                mp = hdr_mp;
                                /* Get priority marking, if any. */
                                mp->b_band = priority;
                                mp->b_cont = carve_mp;
                        }
                        ipha = (ipha_t *)mp->b_rptr;
                        /* A frag of a frag might have IPH_MF non-zero */
                        offset_and_flags =
                            ntohs(ipha->ipha_fragment_offset_and_flags) &
                            IPH_MF;
                }
                offset_and_flags |= (uint16_t)(offset >> 3);
                offset_and_flags |= (uint16_t)frag_flag;
                /* Store the offset and flags in the IP header. */
                ipha->ipha_fragment_offset_and_flags = htons(offset_and_flags);

                /* Store the length in the IP header. */
                ip_len = (uint16_t)(len + hdr_len);
                ipha->ipha_length = htons(ip_len);

                /*
                 * Set the IP header checksum.  Note that mp is just
                 * the header, so this is easy to pass to ip_csum.
                 */
                ipha->ipha_hdr_checksum = ip_csum_hdr(ipha);

                BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutFragCreates);

                error = postfragfn(mp, nce, ixaflags, ip_len, xmit_hint, szone,
                    nolzid, ixa_cookie);
                /* All done if we just consumed the hdr_mp. */
                if (mp == hdr_mp) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutFragOKs);
                        return (error);
                }
                if (error != 0 && error != EWOULDBLOCK) {
                        DTRACE_PROBE2(ip__xmit__frag__fail, ill_t *, ill,
                            mblk_t *, hdr_mp);
                        /* No point in sending the other fragments */
                        break;
                }

                /* Otherwise, advance and loop. */
                offset += len;
        }
        /* Clean up following allocation failure. */
        BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutFragFails);
        ip_drop_output("FragFails: loop ended", NULL, ill);
        if (mp != hdr_mp)
                freeb(hdr_mp);
        if (mp != mp_orig)
                freemsg(mp_orig);
        return (error);
}

/*
 * Copy the header plus those options which have the copy bit set
 */
static mblk_t *
ip_fragment_copyhdr(uchar_t *rptr, int hdr_len, int offset, ip_stack_t *ipst,
    mblk_t *src)
{
        mblk_t  *mp;
        uchar_t *up;

        /*
         * Quick check if we need to look for options without the copy bit
         * set
         */
        mp = allocb_tmpl(ipst->ips_ip_wroff_extra + hdr_len, src);
        if (!mp)
                return (mp);
        mp->b_rptr += ipst->ips_ip_wroff_extra;
        if (hdr_len == IP_SIMPLE_HDR_LENGTH || offset != 0) {
                bcopy(rptr, mp->b_rptr, hdr_len);
                mp->b_wptr += hdr_len + ipst->ips_ip_wroff_extra;
                return (mp);
        }
        up  = mp->b_rptr;
        bcopy(rptr, up, IP_SIMPLE_HDR_LENGTH);
        up += IP_SIMPLE_HDR_LENGTH;
        rptr += IP_SIMPLE_HDR_LENGTH;
        hdr_len -= IP_SIMPLE_HDR_LENGTH;
        while (hdr_len > 0) {
                uint32_t optval;
                uint32_t optlen;

                optval = *rptr;
                if (optval == IPOPT_EOL)
                        break;
                if (optval == IPOPT_NOP)
                        optlen = 1;
                else
                        optlen = rptr[1];
                if (optval & IPOPT_COPY) {
                        bcopy(rptr, up, optlen);
                        up += optlen;
                }
                rptr += optlen;
                hdr_len -= optlen;
        }
        /*
         * Make sure that we drop an even number of words by filling
         * with EOL to the next word boundary.
         */
        for (hdr_len = up - (mp->b_rptr + IP_SIMPLE_HDR_LENGTH);
            hdr_len & 0x3; hdr_len++)
                *up++ = IPOPT_EOL;
        mp->b_wptr = up;
        /* Update header length */
        mp->b_rptr[0] = (uint8_t)((IP_VERSION << 4) | ((up - mp->b_rptr) >> 2));
        return (mp);
}

/*
 * Update any source route, record route, or timestamp options when
 * sending a packet back to ourselves.
 * Check that we are at end of strict source route.
 * The options have been sanity checked by ip_output_options().
 */
void
ip_output_local_options(ipha_t *ipha, ip_stack_t *ipst)
{
        ipoptp_t        opts;
        uchar_t         *opt;
        uint8_t         optval;
        uint8_t         optlen;
        ipaddr_t        dst;
        uint32_t        ts;
        timestruc_t     now;

        for (optval = ipoptp_first(&opts, ipha);
            optval != IPOPT_EOL;
            optval = ipoptp_next(&opts)) {
                opt = opts.ipoptp_cur;
                optlen = opts.ipoptp_len;
                ASSERT((opts.ipoptp_flags & IPOPTP_ERROR) == 0);
                switch (optval) {
                        uint32_t off;
                case IPOPT_SSRR:
                case IPOPT_LSRR:
                        off = opt[IPOPT_OFFSET];
                        off--;
                        if (optlen < IP_ADDR_LEN ||
                            off > optlen - IP_ADDR_LEN) {
                                /* End of source route */
                                break;
                        }
                        /*
                         * This will only happen if two consecutive entries
                         * in the source route contains our address or if
                         * it is a packet with a loose source route which
                         * reaches us before consuming the whole source route
                         */

                        if (optval == IPOPT_SSRR) {
                                return;
                        }
                        /*
                         * Hack: instead of dropping the packet truncate the
                         * source route to what has been used by filling the
                         * rest with IPOPT_NOP.
                         */
                        opt[IPOPT_OLEN] = (uint8_t)off;
                        while (off < optlen) {
                                opt[off++] = IPOPT_NOP;
                        }
                        break;
                case IPOPT_RR:
                        off = opt[IPOPT_OFFSET];
                        off--;
                        if (optlen < IP_ADDR_LEN ||
                            off > optlen - IP_ADDR_LEN) {
                                /* No more room - ignore */
                                ip1dbg((
                                    "ip_output_local_options: end of RR\n"));
                                break;
                        }
                        dst = htonl(INADDR_LOOPBACK);
                        bcopy(&dst, (char *)opt + off, IP_ADDR_LEN);
                        opt[IPOPT_OFFSET] += IP_ADDR_LEN;
                        break;
                case IPOPT_TS:
                        /* Insert timestamp if there is romm */
                        switch (opt[IPOPT_POS_OV_FLG] & 0x0F) {
                        case IPOPT_TS_TSONLY:
                                off = IPOPT_TS_TIMELEN;
                                break;
                        case IPOPT_TS_PRESPEC:
                        case IPOPT_TS_PRESPEC_RFC791:
                                /* Verify that the address matched */
                                off = opt[IPOPT_OFFSET] - 1;
                                bcopy((char *)opt + off, &dst, IP_ADDR_LEN);
                                if (ip_type_v4(dst, ipst) != IRE_LOCAL) {
                                        /* Not for us */
                                        break;
                                }
                                /* FALLTHROUGH */
                        case IPOPT_TS_TSANDADDR:
                                off = IP_ADDR_LEN + IPOPT_TS_TIMELEN;
                                break;
                        default:
                                /*
                                 * ip_*put_options should have already
                                 * dropped this packet.
                                 */
                                cmn_err(CE_PANIC, "ip_output_local_options: "
                                    "unknown IT - bug in ip_output_options?\n");
                                return; /* Keep "lint" happy */
                        }
                        if (opt[IPOPT_OFFSET] - 1 + off > optlen) {
                                /* Increase overflow counter */
                                off = (opt[IPOPT_POS_OV_FLG] >> 4) + 1;
                                opt[IPOPT_POS_OV_FLG] = (uint8_t)
                                    (opt[IPOPT_POS_OV_FLG] & 0x0F) |
                                    (off << 4);
                                break;
                        }
                        off = opt[IPOPT_OFFSET] - 1;
                        switch (opt[IPOPT_POS_OV_FLG] & 0x0F) {
                        case IPOPT_TS_PRESPEC:
                        case IPOPT_TS_PRESPEC_RFC791:
                        case IPOPT_TS_TSANDADDR:
                                dst = htonl(INADDR_LOOPBACK);
                                bcopy(&dst, (char *)opt + off, IP_ADDR_LEN);
                                opt[IPOPT_OFFSET] += IP_ADDR_LEN;
                                /* FALLTHROUGH */
                        case IPOPT_TS_TSONLY:
                                off = opt[IPOPT_OFFSET] - 1;
                                /* Compute # of milliseconds since midnight */
                                gethrestime(&now);
                                ts = (now.tv_sec % (24 * 60 * 60)) * 1000 +
                                    NSEC2MSEC(now.tv_nsec);
                                bcopy(&ts, (char *)opt + off, IPOPT_TS_TIMELEN);
                                opt[IPOPT_OFFSET] += IPOPT_TS_TIMELEN;
                                break;
                        }
                        break;
                }
        }
}

/*
 * Prepend an M_DATA fastpath header, and if none present prepend a
 * DL_UNITDATA_REQ. Frees the mblk on failure.
 *
 * nce_dlur_mp and nce_fp_mp can not disappear once they have been set.
 * If there is a change to them, the nce will be deleted (condemned) and
 * a new nce_t will be created when packets are sent. Thus we need no locks
 * to access those fields.
 *
 * We preserve b_band to support IPQoS. If a DL_UNITDATA_REQ is prepended
 * we place b_band in dl_priority.dl_max.
 */
static mblk_t *
ip_xmit_attach_llhdr(mblk_t *mp, nce_t *nce)
{
        uint_t  hlen;
        mblk_t *mp1;
        uint_t  priority;
        uchar_t *rptr;

        rptr = mp->b_rptr;

        ASSERT(DB_TYPE(mp) == M_DATA);
        priority = mp->b_band;

        ASSERT(nce != NULL);
        if ((mp1 = nce->nce_fp_mp) != NULL) {
                hlen = MBLKL(mp1);
                /*
                 * Check if we have enough room to prepend fastpath
                 * header
                 */
                if (hlen != 0 && (rptr - mp->b_datap->db_base) >= hlen) {
                        rptr -= hlen;
                        bcopy(mp1->b_rptr, rptr, hlen);
                        /*
                         * Set the b_rptr to the start of the link layer
                         * header
                         */
                        mp->b_rptr = rptr;
                        return (mp);
                }
                mp1 = copyb(mp1);
                if (mp1 == NULL) {
                        ill_t *ill = nce->nce_ill;

                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutDiscards);
                        ip_drop_output("ipIfStatsOutDiscards", mp, ill);
                        freemsg(mp);
                        return (NULL);
                }
                mp1->b_band = priority;
                mp1->b_cont = mp;
                DB_CKSUMSTART(mp1) = DB_CKSUMSTART(mp);
                DB_CKSUMSTUFF(mp1) = DB_CKSUMSTUFF(mp);
                DB_CKSUMEND(mp1) = DB_CKSUMEND(mp);
                DB_CKSUMFLAGS(mp1) = DB_CKSUMFLAGS(mp);
                DB_LSOMSS(mp1) = DB_LSOMSS(mp);
                DTRACE_PROBE1(ip__xmit__copyb, (mblk_t *), mp1);
                /*
                 * XXX disable ICK_VALID and compute checksum
                 * here; can happen if nce_fp_mp changes and
                 * it can't be copied now due to insufficient
                 * space. (unlikely, fp mp can change, but it
                 * does not increase in length)
                 */
                return (mp1);
        }
        mp1 = copyb(nce->nce_dlur_mp);

        if (mp1 == NULL) {
                ill_t *ill = nce->nce_ill;

                BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutDiscards);
                ip_drop_output("ipIfStatsOutDiscards", mp, ill);
                freemsg(mp);
                return (NULL);
        }
        mp1->b_cont = mp;
        if (priority != 0) {
                mp1->b_band = priority;
                ((dl_unitdata_req_t *)(mp1->b_rptr))->dl_priority.dl_max =
                    priority;
        }
        return (mp1);
}

/*
 * Finish the outbound IPsec processing. This function is called from
 * ipsec_out_process() if the IPsec packet was processed
 * synchronously, or from {ah,esp}_kcf_callback_outbound() if it was processed
 * asynchronously.
 *
 * This is common to IPv4 and IPv6.
 */
int
ip_output_post_ipsec(mblk_t *mp, ip_xmit_attr_t *ixa)
{
        iaflags_t       ixaflags = ixa->ixa_flags;
        uint_t          pktlen;


        /* AH/ESP don't update ixa_pktlen when they modify the packet */
        if (ixaflags & IXAF_IS_IPV4) {
                ipha_t          *ipha = (ipha_t *)mp->b_rptr;

                ASSERT(IPH_HDR_VERSION(ipha) == IPV4_VERSION);
                pktlen = ntohs(ipha->ipha_length);
        } else {
                ip6_t           *ip6h = (ip6_t *)mp->b_rptr;

                ASSERT(IPH_HDR_VERSION(mp->b_rptr) == IPV6_VERSION);
                pktlen = ntohs(ip6h->ip6_plen) + IPV6_HDR_LEN;
        }

        /*
         * We release any hard reference on the SAs here to make
         * sure the SAs can be garbage collected. ipsr_sa has a soft reference
         * on the SAs.
         * If in the future we want the hard latching of the SAs in the
         * ip_xmit_attr_t then we should remove this.
         */
        if (ixa->ixa_ipsec_esp_sa != NULL) {
                IPSA_REFRELE(ixa->ixa_ipsec_esp_sa);
                ixa->ixa_ipsec_esp_sa = NULL;
        }
        if (ixa->ixa_ipsec_ah_sa != NULL) {
                IPSA_REFRELE(ixa->ixa_ipsec_ah_sa);
                ixa->ixa_ipsec_ah_sa = NULL;
        }

        /* Do we need to fragment? */
        if ((ixa->ixa_flags & IXAF_IPV6_ADD_FRAGHDR) ||
            pktlen > ixa->ixa_fragsize) {
                if (ixaflags & IXAF_IS_IPV4) {
                        ASSERT(!(ixa->ixa_flags & IXAF_IPV6_ADD_FRAGHDR));
                        /*
                         * We check for the DF case in ipsec_out_process
                         * hence this only handles the non-DF case.
                         */
                        return (ip_fragment_v4(mp, ixa->ixa_nce, ixa->ixa_flags,
                            pktlen, ixa->ixa_fragsize,
                            ixa->ixa_xmit_hint, ixa->ixa_zoneid,
                            ixa->ixa_no_loop_zoneid, ixa->ixa_postfragfn,
                            &ixa->ixa_cookie));
                } else {
                        mp = ip_fraghdr_add_v6(mp, ixa->ixa_ident, ixa);
                        if (mp == NULL) {
                                /* MIB and ip_drop_output already done */
                                return (ENOMEM);
                        }
                        pktlen += sizeof (ip6_frag_t);
                        if (pktlen > ixa->ixa_fragsize) {
                                return (ip_fragment_v6(mp, ixa->ixa_nce,
                                    ixa->ixa_flags, pktlen,
                                    ixa->ixa_fragsize, ixa->ixa_xmit_hint,
                                    ixa->ixa_zoneid, ixa->ixa_no_loop_zoneid,
                                    ixa->ixa_postfragfn, &ixa->ixa_cookie));
                        }
                }
        }
        return ((ixa->ixa_postfragfn)(mp, ixa->ixa_nce, ixa->ixa_flags,
            pktlen, ixa->ixa_xmit_hint, ixa->ixa_zoneid,
            ixa->ixa_no_loop_zoneid, NULL));
}

/*
 * Finish the inbound IPsec processing. This function is called from
 * ipsec_out_process() if the IPsec packet was processed
 * synchronously, or from {ah,esp}_kcf_callback_outbound() if it was processed
 * asynchronously.
 *
 * This is common to IPv4 and IPv6.
 */
void
ip_input_post_ipsec(mblk_t *mp, ip_recv_attr_t *ira)
{
        iaflags_t       iraflags = ira->ira_flags;

        /* Length might have changed */
        if (iraflags & IRAF_IS_IPV4) {
                ipha_t          *ipha = (ipha_t *)mp->b_rptr;

                ASSERT(IPH_HDR_VERSION(ipha) == IPV4_VERSION);
                ira->ira_pktlen = ntohs(ipha->ipha_length);
                ira->ira_ip_hdr_length = IPH_HDR_LENGTH(ipha);
                ira->ira_protocol = ipha->ipha_protocol;

                ip_fanout_v4(mp, ipha, ira);
        } else {
                ip6_t           *ip6h = (ip6_t *)mp->b_rptr;
                uint8_t         *nexthdrp;

                ASSERT(IPH_HDR_VERSION(mp->b_rptr) == IPV6_VERSION);
                ira->ira_pktlen = ntohs(ip6h->ip6_plen) + IPV6_HDR_LEN;
                if (!ip_hdr_length_nexthdr_v6(mp, ip6h, &ira->ira_ip_hdr_length,
                    &nexthdrp)) {
                        /* Malformed packet */
                        BUMP_MIB(ira->ira_ill->ill_ip_mib, ipIfStatsInDiscards);
                        ip_drop_input("ipIfStatsInDiscards", mp, ira->ira_ill);
                        freemsg(mp);
                        return;
                }
                ira->ira_protocol = *nexthdrp;
                ip_fanout_v6(mp, ip6h, ira);
        }
}

/*
 * Select which AH & ESP SA's to use (if any) for the outbound packet.
 *
 * If this function returns B_TRUE, the requested SA's have been filled
 * into the ixa_ipsec_*_sa pointers.
 *
 * If the function returns B_FALSE, the packet has been "consumed", most
 * likely by an ACQUIRE sent up via PF_KEY to a key management daemon.
 *
 * The SA references created by the protocol-specific "select"
 * function will be released in ip_output_post_ipsec.
 */
static boolean_t
ipsec_out_select_sa(mblk_t *mp, ip_xmit_attr_t *ixa)
{
        boolean_t need_ah_acquire = B_FALSE, need_esp_acquire = B_FALSE;
        ipsec_policy_t *pp;
        ipsec_action_t *ap;

        ASSERT(ixa->ixa_flags & IXAF_IPSEC_SECURE);
        ASSERT((ixa->ixa_ipsec_policy != NULL) ||
            (ixa->ixa_ipsec_action != NULL));

        ap = ixa->ixa_ipsec_action;
        if (ap == NULL) {
                pp = ixa->ixa_ipsec_policy;
                ASSERT(pp != NULL);
                ap = pp->ipsp_act;
                ASSERT(ap != NULL);
        }

        /*
         * We have an action.  now, let's select SA's.
         * A side effect of setting ixa_ipsec_*_sa is that it will
         * be cached in the conn_t.
         */
        if (ap->ipa_want_esp) {
                if (ixa->ixa_ipsec_esp_sa == NULL) {
                        need_esp_acquire = !ipsec_outbound_sa(mp, ixa,
                            IPPROTO_ESP);
                }
                ASSERT(need_esp_acquire || ixa->ixa_ipsec_esp_sa != NULL);
        }

        if (ap->ipa_want_ah) {
                if (ixa->ixa_ipsec_ah_sa == NULL) {
                        need_ah_acquire = !ipsec_outbound_sa(mp, ixa,
                            IPPROTO_AH);
                }
                ASSERT(need_ah_acquire || ixa->ixa_ipsec_ah_sa != NULL);
                /*
                 * The ESP and AH processing order needs to be preserved
                 * when both protocols are required (ESP should be applied
                 * before AH for an outbound packet). Force an ESP ACQUIRE
                 * when both ESP and AH are required, and an AH ACQUIRE
                 * is needed.
                 */
                if (ap->ipa_want_esp && need_ah_acquire)
                        need_esp_acquire = B_TRUE;
        }

        /*
         * Send an ACQUIRE (extended, regular, or both) if we need one.
         * Release SAs that got referenced, but will not be used until we
         * acquire _all_ of the SAs we need.
         */
        if (need_ah_acquire || need_esp_acquire) {
                if (ixa->ixa_ipsec_ah_sa != NULL) {
                        IPSA_REFRELE(ixa->ixa_ipsec_ah_sa);
                        ixa->ixa_ipsec_ah_sa = NULL;
                }
                if (ixa->ixa_ipsec_esp_sa != NULL) {
                        IPSA_REFRELE(ixa->ixa_ipsec_esp_sa);
                        ixa->ixa_ipsec_esp_sa = NULL;
                }

                sadb_acquire(mp, ixa, need_ah_acquire, need_esp_acquire);
                return (B_FALSE);
        }

        return (B_TRUE);
}

/*
 * Handle IPsec output processing.
 * This function is only entered once for a given packet.
 * We try to do things synchronously, but if we need to have user-level
 * set up SAs, or ESP or AH uses asynchronous kEF, then the operation
 * will be completed
 *  - when the SAs are added in esp_add_sa_finish/ah_add_sa_finish
 *  - when asynchronous ESP is done it will do AH
 *
 * In all cases we come back in ip_output_post_ipsec() to fragment and
 * send out the packet.
 */
int
ipsec_out_process(mblk_t *mp, ip_xmit_attr_t *ixa)
{
        ill_t           *ill = ixa->ixa_nce->nce_ill;
        ip_stack_t      *ipst = ixa->ixa_ipst;
        ipsec_stack_t   *ipss;
        ipsec_policy_t  *pp;
        ipsec_action_t  *ap;

        ASSERT(ixa->ixa_flags & IXAF_IPSEC_SECURE);

        ASSERT((ixa->ixa_ipsec_policy != NULL) ||
            (ixa->ixa_ipsec_action != NULL));

        ipss = ipst->ips_netstack->netstack_ipsec;
        if (!ipsec_loaded(ipss)) {
                BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutDiscards);
                ip_drop_packet(mp, B_TRUE, ill,
                    DROPPER(ipss, ipds_ip_ipsec_not_loaded),
                    &ipss->ipsec_dropper);
                return (ENOTSUP);
        }

        ap = ixa->ixa_ipsec_action;
        if (ap == NULL) {
                pp = ixa->ixa_ipsec_policy;
                ASSERT(pp != NULL);
                ap = pp->ipsp_act;
                ASSERT(ap != NULL);
        }

        /* Handle explicit drop action and bypass. */
        switch (ap->ipa_act.ipa_type) {
        case IPSEC_ACT_DISCARD:
        case IPSEC_ACT_REJECT:
                ip_drop_packet(mp, B_FALSE, ill,
                    DROPPER(ipss, ipds_spd_explicit), &ipss->ipsec_spd_dropper);
                return (EHOSTUNREACH);  /* IPsec policy failure */
        case IPSEC_ACT_BYPASS:
                return (ip_output_post_ipsec(mp, ixa));
        }

        /*
         * The order of processing is first insert a IP header if needed.
         * Then insert the ESP header and then the AH header.
         */
        if ((ixa->ixa_flags & IXAF_IS_IPV4) && ap->ipa_want_se) {
                /*
                 * First get the outer IP header before sending
                 * it to ESP.
                 */
                ipha_t *oipha, *iipha;
                mblk_t *outer_mp, *inner_mp;

                if ((outer_mp = allocb(sizeof (ipha_t), BPRI_HI)) == NULL) {
                        (void) mi_strlog(ill->ill_rq, 0,
                            SL_ERROR|SL_TRACE|SL_CONSOLE,
                            "ipsec_out_process: "
                            "Self-Encapsulation failed: Out of memory\n");
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutDiscards);
                        ip_drop_output("ipIfStatsOutDiscards", mp, ill);
                        freemsg(mp);
                        return (ENOBUFS);
                }
                inner_mp = mp;
                ASSERT(inner_mp->b_datap->db_type == M_DATA);
                oipha = (ipha_t *)outer_mp->b_rptr;
                iipha = (ipha_t *)inner_mp->b_rptr;
                *oipha = *iipha;
                outer_mp->b_wptr += sizeof (ipha_t);
                oipha->ipha_length = htons(ntohs(iipha->ipha_length) +
                    sizeof (ipha_t));
                oipha->ipha_protocol = IPPROTO_ENCAP;
                oipha->ipha_version_and_hdr_length =
                    IP_SIMPLE_HDR_VERSION;
                oipha->ipha_hdr_checksum = 0;
                oipha->ipha_hdr_checksum = ip_csum_hdr(oipha);
                outer_mp->b_cont = inner_mp;
                mp = outer_mp;

                ixa->ixa_flags |= IXAF_IPSEC_TUNNEL;
        }

        /* If we need to wait for a SA then we can't return any errno */
        if (((ap->ipa_want_ah && (ixa->ixa_ipsec_ah_sa == NULL)) ||
            (ap->ipa_want_esp && (ixa->ixa_ipsec_esp_sa == NULL))) &&
            !ipsec_out_select_sa(mp, ixa))
                return (0);

        /*
         * By now, we know what SA's to use.  Toss over to ESP & AH
         * to do the heavy lifting.
         */
        if (ap->ipa_want_esp) {
                ASSERT(ixa->ixa_ipsec_esp_sa != NULL);

                mp = ixa->ixa_ipsec_esp_sa->ipsa_output_func(mp, ixa);
                if (mp == NULL) {
                        /*
                         * Either it failed or is pending. In the former case
                         * ipIfStatsInDiscards was increased.
                         */
                        return (0);
                }
        }

        if (ap->ipa_want_ah) {
                ASSERT(ixa->ixa_ipsec_ah_sa != NULL);

                mp = ixa->ixa_ipsec_ah_sa->ipsa_output_func(mp, ixa);
                if (mp == NULL) {
                        /*
                         * Either it failed or is pending. In the former case
                         * ipIfStatsInDiscards was increased.
                         */
                        return (0);
                }
        }
        /*
         * We are done with IPsec processing. Send it over
         * the wire.
         */
        return (ip_output_post_ipsec(mp, ixa));
}

/*
 * ioctls that go through a down/up sequence may need to wait for the down
 * to complete. This involves waiting for the ire and ipif refcnts to go down
 * to zero. Subsequently the ioctl is restarted from ipif_ill_refrele_tail.
 */
/* ARGSUSED */
void
ip_reprocess_ioctl(ipsq_t *ipsq, queue_t *q, mblk_t *mp, void *dummy_arg)
{
        struct iocblk *iocp;
        mblk_t *mp1;
        ip_ioctl_cmd_t *ipip;
        int err;
        sin_t   *sin;
        struct lifreq *lifr;
        struct ifreq *ifr;

        iocp = (struct iocblk *)mp->b_rptr;
        ASSERT(ipsq != NULL);
        /* Existence of mp1 verified in ip_wput_nondata */
        mp1 = mp->b_cont->b_cont;
        ipip = ip_sioctl_lookup(iocp->ioc_cmd);
        if (ipip->ipi_cmd == SIOCSLIFNAME || ipip->ipi_cmd == IF_UNITSEL) {
                /*
                 * Special case where ipx_current_ipif is not set:
                 * ill_phyint_reinit merged the v4 and v6 into a single ipsq.
                 * We are here as were not able to complete the operation in
                 * ipif_set_values because we could not become exclusive on
                 * the new ipsq.
                 */
                ill_t *ill = q->q_ptr;
                ipsq_current_start(ipsq, ill->ill_ipif, ipip->ipi_cmd);
        }
        ASSERT(ipsq->ipsq_xop->ipx_current_ipif != NULL);

        if (ipip->ipi_cmd_type == IF_CMD) {
                /* This a old style SIOC[GS]IF* command */
                ifr = (struct ifreq *)mp1->b_rptr;
                sin = (sin_t *)&ifr->ifr_addr;
        } else if (ipip->ipi_cmd_type == LIF_CMD) {
                /* This a new style SIOC[GS]LIF* command */
                lifr = (struct lifreq *)mp1->b_rptr;
                sin = (sin_t *)&lifr->lifr_addr;
        } else {
                sin = NULL;
        }

        err = (*ipip->ipi_func_restart)(ipsq->ipsq_xop->ipx_current_ipif, sin,
            q, mp, ipip, mp1->b_rptr);

        DTRACE_PROBE4(ipif__ioctl, char *, "ip_reprocess_ioctl finish",
            int, ipip->ipi_cmd,
            ill_t *, ipsq->ipsq_xop->ipx_current_ipif->ipif_ill,
            ipif_t *, ipsq->ipsq_xop->ipx_current_ipif);

        ip_ioctl_finish(q, mp, err, IPI2MODE(ipip), ipsq);
}

/*
 * ioctl processing
 *
 * ioctl processing starts with ip_sioctl_copyin_setup(), which looks up
 * the ioctl command in the ioctl tables, determines the copyin data size
 * from the ipi_copyin_size field, and does an mi_copyin() of that size.
 *
 * ioctl processing then continues when the M_IOCDATA makes its way down to
 * ip_wput_nondata().  The ioctl is looked up again in the ioctl table, its
 * associated 'conn' is refheld till the end of the ioctl and the general
 * ioctl processing function ip_process_ioctl() is called to extract the
 * arguments and process the ioctl.  To simplify extraction, ioctl commands
 * are "typed" based on the arguments they take (e.g., LIF_CMD which takes a
 * `struct lifreq'), and a common extract function (e.g., ip_extract_lifreq())
 * is used to extract the ioctl's arguments.
 *
 * ip_process_ioctl determines if the ioctl needs to be serialized, and if
 * so goes thru the serialization primitive ipsq_try_enter. Then the
 * appropriate function to handle the ioctl is called based on the entry in
 * the ioctl table. ioctl completion is encapsulated in ip_ioctl_finish
 * which also refreleases the 'conn' that was refheld at the start of the
 * ioctl. Finally ipsq_exit is called if needed to exit the ipsq.
 *
 * Many exclusive ioctls go thru an internal down up sequence as part of
 * the operation. For example an attempt to change the IP address of an
 * ipif entails ipif_down, set address, ipif_up. Bringing down the interface
 * does all the cleanup such as deleting all ires that use this address.
 * Then we need to wait till all references to the interface go away.
 */
void
ip_process_ioctl(ipsq_t *ipsq, queue_t *q, mblk_t *mp, void *arg)
{
        struct iocblk *iocp = (struct iocblk *)mp->b_rptr;
        ip_ioctl_cmd_t *ipip = arg;
        ip_extract_func_t *extract_funcp;
        cmd_info_t ci;
        int err;
        boolean_t entered_ipsq = B_FALSE;

        ip3dbg(("ip_process_ioctl: ioctl %X\n", iocp->ioc_cmd));

        if (ipip == NULL)
                ipip = ip_sioctl_lookup(iocp->ioc_cmd);

        /*
         * SIOCLIFADDIF needs to go thru a special path since the
         * ill may not exist yet. This happens in the case of lo0
         * which is created using this ioctl.
         */
        if (ipip->ipi_cmd == SIOCLIFADDIF) {
                err = ip_sioctl_addif(NULL, NULL, q, mp, NULL, NULL);
                DTRACE_PROBE4(ipif__ioctl, char *, "ip_process_ioctl finish",
                    int, ipip->ipi_cmd, ill_t *, NULL, ipif_t *, NULL);
                ip_ioctl_finish(q, mp, err, IPI2MODE(ipip), NULL);
                return;
        }

        ci.ci_ipif = NULL;
        switch (ipip->ipi_cmd_type) {
        case MISC_CMD:
        case MSFILT_CMD:
                /*
                 * All MISC_CMD ioctls come in here -- e.g. SIOCGLIFCONF.
                 */
                if (ipip->ipi_cmd == IF_UNITSEL) {
                        /* ioctl comes down the ill */
                        ci.ci_ipif = ((ill_t *)q->q_ptr)->ill_ipif;
                        ipif_refhold(ci.ci_ipif);
                }
                err = 0;
                ci.ci_sin = NULL;
                ci.ci_sin6 = NULL;
                ci.ci_lifr = NULL;
                extract_funcp = NULL;
                break;

        case IF_CMD:
        case LIF_CMD:
                extract_funcp = ip_extract_lifreq;
                break;

        case ARP_CMD:
        case XARP_CMD:
                extract_funcp = ip_extract_arpreq;
                break;

        default:
                ASSERT(0);
        }

        if (extract_funcp != NULL) {
                err = (*extract_funcp)(q, mp, ipip, &ci);
                if (err != 0) {
                        DTRACE_PROBE4(ipif__ioctl,
                            char *, "ip_process_ioctl finish err",
                            int, ipip->ipi_cmd, ill_t *, NULL, ipif_t *, NULL);
                        ip_ioctl_finish(q, mp, err, IPI2MODE(ipip), NULL);
                        return;
                }

                /*
                 * All of the extraction functions return a refheld ipif.
                 */
                ASSERT(ci.ci_ipif != NULL);
        }

        if (!(ipip->ipi_flags & IPI_WR)) {
                /*
                 * A return value of EINPROGRESS means the ioctl is
                 * either queued and waiting for some reason or has
                 * already completed.
                 */
                err = (*ipip->ipi_func)(ci.ci_ipif, ci.ci_sin, q, mp, ipip,
                    ci.ci_lifr);
                if (ci.ci_ipif != NULL) {
                        DTRACE_PROBE4(ipif__ioctl,
                            char *, "ip_process_ioctl finish RD",
                            int, ipip->ipi_cmd, ill_t *, ci.ci_ipif->ipif_ill,
                            ipif_t *, ci.ci_ipif);
                        ipif_refrele(ci.ci_ipif);
                } else {
                        DTRACE_PROBE4(ipif__ioctl,
                            char *, "ip_process_ioctl finish RD",
                            int, ipip->ipi_cmd, ill_t *, NULL, ipif_t *, NULL);
                }
                ip_ioctl_finish(q, mp, err, IPI2MODE(ipip), NULL);
                return;
        }

        ASSERT(ci.ci_ipif != NULL);

        /*
         * If ipsq is non-NULL, we are already being called exclusively
         */
        ASSERT(ipsq == NULL || IAM_WRITER_IPSQ(ipsq));
        if (ipsq == NULL) {
                ipsq = ipsq_try_enter(ci.ci_ipif, NULL, q, mp, ip_process_ioctl,
                    NEW_OP, B_TRUE);
                if (ipsq == NULL) {
                        ipif_refrele(ci.ci_ipif);
                        return;
                }
                entered_ipsq = B_TRUE;
        }
        /*
         * Release the ipif so that ipif_down and friends that wait for
         * references to go away are not misled about the current ipif_refcnt
         * values. We are writer so we can access the ipif even after releasing
         * the ipif.
         */
        ipif_refrele(ci.ci_ipif);

        ipsq_current_start(ipsq, ci.ci_ipif, ipip->ipi_cmd);

        /*
         * A return value of EINPROGRESS means the ioctl is
         * either queued and waiting for some reason or has
         * already completed.
         */
        err = (*ipip->ipi_func)(ci.ci_ipif, ci.ci_sin, q, mp, ipip, ci.ci_lifr);

        DTRACE_PROBE4(ipif__ioctl, char *, "ip_process_ioctl finish WR",
            int, ipip->ipi_cmd,
            ill_t *, ci.ci_ipif == NULL ? NULL : ci.ci_ipif->ipif_ill,
            ipif_t *, ci.ci_ipif);
        ip_ioctl_finish(q, mp, err, IPI2MODE(ipip), ipsq);

        if (entered_ipsq)
                ipsq_exit(ipsq);
}

/*
 * Complete the ioctl. Typically ioctls use the mi package and need to
 * do mi_copyout/mi_copy_done.
 */
void
ip_ioctl_finish(queue_t *q, mblk_t *mp, int err, int mode, ipsq_t *ipsq)
{
        conn_t  *connp = NULL;

        if (err == EINPROGRESS)
                return;

        if (CONN_Q(q)) {
                connp = Q_TO_CONN(q);
                ASSERT(connp->conn_ref >= 2);
        }

        switch (mode) {
        case COPYOUT:
                if (err == 0)
                        mi_copyout(q, mp);
                else
                        mi_copy_done(q, mp, err);
                break;

        case NO_COPYOUT:
                mi_copy_done(q, mp, err);
                break;

        default:
                ASSERT(mode == CONN_CLOSE);     /* aborted through CONN_CLOSE */
                break;
        }

        /*
         * The conn refhold and ioctlref placed on the conn at the start of the
         * ioctl are released here.
         */
        if (connp != NULL) {
                CONN_DEC_IOCTLREF(connp);
                CONN_OPER_PENDING_DONE(connp);
        }

        if (ipsq != NULL)
                ipsq_current_finish(ipsq);
}

/* Handles all non data messages */
int
ip_wput_nondata(queue_t *q, mblk_t *mp)
{
        mblk_t          *mp1;
        struct iocblk   *iocp;
        ip_ioctl_cmd_t  *ipip;
        conn_t          *connp;
        cred_t          *cr;
        char            *proto_str;

        if (CONN_Q(q))
                connp = Q_TO_CONN(q);
        else
                connp = NULL;

        switch (DB_TYPE(mp)) {
        case M_IOCTL:
                /*
                 * IOCTL processing begins in ip_sioctl_copyin_setup which
                 * will arrange to copy in associated control structures.
                 */
                ip_sioctl_copyin_setup(q, mp);
                return (0);
        case M_IOCDATA:
                /*
                 * Ensure that this is associated with one of our trans-
                 * parent ioctls.  If it's not ours, discard it if we're
                 * running as a driver, or pass it on if we're a module.
                 */
                iocp = (struct iocblk *)mp->b_rptr;
                ipip = ip_sioctl_lookup(iocp->ioc_cmd);
                if (ipip == NULL) {
                        if (q->q_next == NULL) {
                                goto nak;
                        } else {
                                putnext(q, mp);
                        }
                        return (0);
                }
                if ((q->q_next != NULL) && !(ipip->ipi_flags & IPI_MODOK)) {
                        /*
                         * The ioctl is one we recognise, but is not consumed
                         * by IP as a module and we are a module, so we drop
                         */
                        goto nak;
                }

                /* IOCTL continuation following copyin or copyout. */
                if (mi_copy_state(q, mp, NULL) == -1) {
                        /*
                         * The copy operation failed.  mi_copy_state already
                         * cleaned up, so we're out of here.
                         */
                        return (0);
                }
                /*
                 * If we just completed a copy in, we become writer and
                 * continue processing in ip_sioctl_copyin_done.  If it
                 * was a copy out, we call mi_copyout again.  If there is
                 * nothing more to copy out, it will complete the IOCTL.
                 */
                if (MI_COPY_DIRECTION(mp) == MI_COPY_IN) {
                        if (!(mp1 = mp->b_cont) || !(mp1 = mp1->b_cont)) {
                                mi_copy_done(q, mp, EPROTO);
                                return (0);
                        }
                        /*
                         * Check for cases that need more copying.  A return
                         * value of 0 means a second copyin has been started,
                         * so we return; a return value of 1 means no more
                         * copying is needed, so we continue.
                         */
                        if (ipip->ipi_cmd_type == MSFILT_CMD &&
                            MI_COPY_COUNT(mp) == 1) {
                                if (ip_copyin_msfilter(q, mp) == 0)
                                        return (0);
                        }
                        /*
                         * Refhold the conn, till the ioctl completes. This is
                         * needed in case the ioctl ends up in the pending mp
                         * list. Every mp in the ipx_pending_mp list must have
                         * a refhold on the conn to resume processing. The
                         * refhold is released when the ioctl completes
                         * (whether normally or abnormally). An ioctlref is also
                         * placed on the conn to prevent TCP from removing the
                         * queue needed to send the ioctl reply back.
                         * In all cases ip_ioctl_finish is called to finish
                         * the ioctl and release the refholds.
                         */
                        if (connp != NULL) {
                                /* This is not a reentry */
                                CONN_INC_REF(connp);
                                CONN_INC_IOCTLREF(connp);
                        } else {
                                if (!(ipip->ipi_flags & IPI_MODOK)) {
                                        mi_copy_done(q, mp, EINVAL);
                                        return (0);
                                }
                        }

                        ip_process_ioctl(NULL, q, mp, ipip);

                } else {
                        mi_copyout(q, mp);
                }
                return (0);

        case M_IOCNAK:
                /*
                 * The only way we could get here is if a resolver didn't like
                 * an IOCTL we sent it.  This shouldn't happen.
                 */
                (void) mi_strlog(q, 1, SL_ERROR|SL_TRACE,
                    "ip_wput_nondata: unexpected M_IOCNAK, ioc_cmd 0x%x",
                    ((struct iocblk *)mp->b_rptr)->ioc_cmd);
                freemsg(mp);
                return (0);
        case M_IOCACK:
                /* /dev/ip shouldn't see this */
                goto nak;
        case M_FLUSH:
                if (*mp->b_rptr & FLUSHW)
                        flushq(q, FLUSHALL);
                if (q->q_next) {
                        putnext(q, mp);
                        return (0);
                }
                if (*mp->b_rptr & FLUSHR) {
                        *mp->b_rptr &= ~FLUSHW;
                        qreply(q, mp);
                        return (0);
                }
                freemsg(mp);
                return (0);
        case M_CTL:
                break;
        case M_PROTO:
        case M_PCPROTO:
                /*
                 * The only PROTO messages we expect are SNMP-related.
                 */
                switch (((union T_primitives *)mp->b_rptr)->type) {
                case T_SVR4_OPTMGMT_REQ:
                        ip2dbg(("ip_wput_nondata: T_SVR4_OPTMGMT_REQ "
                            "flags %x\n",
                            ((struct T_optmgmt_req *)mp->b_rptr)->MGMT_flags));

                        if (connp == NULL) {
                                proto_str = "T_SVR4_OPTMGMT_REQ";
                                goto protonak;
                        }

                        /*
                         * All Solaris components should pass a db_credp
                         * for this TPI message, hence we ASSERT.
                         * But in case there is some other M_PROTO that looks
                         * like a TPI message sent by some other kernel
                         * component, we check and return an error.
                         */
                        cr = msg_getcred(mp, NULL);
                        ASSERT(cr != NULL);
                        if (cr == NULL) {
                                mp = mi_tpi_err_ack_alloc(mp, TSYSERR, EINVAL);
                                if (mp != NULL)
                                        qreply(q, mp);
                                return (0);
                        }

                        if (!snmpcom_req(q, mp, ip_snmp_set, ip_snmp_get, cr)) {
                                proto_str = "Bad SNMPCOM request?";
                                goto protonak;
                        }
                        return (0);
                default:
                        ip1dbg(("ip_wput_nondata: dropping M_PROTO prim %u\n",
                            (int)*(uint_t *)mp->b_rptr));
                        freemsg(mp);
                        return (0);
                }
        default:
                break;
        }
        if (q->q_next) {
                putnext(q, mp);
        } else
                freemsg(mp);
        return (0);

nak:
        iocp->ioc_error = EINVAL;
        mp->b_datap->db_type = M_IOCNAK;
        iocp->ioc_count = 0;
        qreply(q, mp);
        return (0);

protonak:
        cmn_err(CE_NOTE, "IP doesn't process %s as a module", proto_str);
        if ((mp = mi_tpi_err_ack_alloc(mp, TPROTO, EINVAL)) != NULL)
                qreply(q, mp);
        return (0);
}

/*
 * Process IP options in an outbound packet.  Verify that the nexthop in a
 * strict source route is onlink.
 * Returns non-zero if something fails in which case an ICMP error has been
 * sent and mp freed.
 *
 * Assumes the ULP has called ip_massage_options to move nexthop into ipha_dst.
 */
int
ip_output_options(mblk_t *mp, ipha_t *ipha, ip_xmit_attr_t *ixa, ill_t *ill)
{
        ipoptp_t        opts;
        uchar_t         *opt;
        uint8_t         optval;
        uint8_t         optlen;
        ipaddr_t        dst;
        intptr_t        code = 0;
        ire_t           *ire;
        ip_stack_t      *ipst = ixa->ixa_ipst;
        ip_recv_attr_t  iras;

        ip2dbg(("ip_output_options\n"));

        dst = ipha->ipha_dst;
        for (optval = ipoptp_first(&opts, ipha);
            optval != IPOPT_EOL;
            optval = ipoptp_next(&opts)) {
                opt = opts.ipoptp_cur;
                optlen = opts.ipoptp_len;
                ip2dbg(("ip_output_options: opt %d, len %d\n",
                    optval, optlen));
                switch (optval) {
                        uint32_t off;
                case IPOPT_SSRR:
                case IPOPT_LSRR:
                        if ((opts.ipoptp_flags & IPOPTP_ERROR) != 0) {
                                ip1dbg((
                                    "ip_output_options: bad option offset\n"));
                                code = (char *)&opt[IPOPT_OLEN] -
                                    (char *)ipha;
                                goto param_prob;
                        }
                        off = opt[IPOPT_OFFSET];
                        ip1dbg(("ip_output_options: next hop 0x%x\n",
                            ntohl(dst)));
                        /*
                         * For strict: verify that dst is directly
                         * reachable.
                         */
                        if (optval == IPOPT_SSRR) {
                                ire = ire_ftable_lookup_v4(dst, 0, 0,
                                    IRE_INTERFACE, NULL, ALL_ZONES,
                                    MATCH_IRE_TYPE, 0, ipst, NULL);
                                if (ire == NULL) {
                                        ip1dbg(("ip_output_options: SSRR not"
                                            " directly reachable: 0x%x\n",
                                            ntohl(dst)));
                                        goto bad_src_route;
                                }
                                ire_refrele(ire);
                        }
                        break;
                case IPOPT_RR:
                        if ((opts.ipoptp_flags & IPOPTP_ERROR) != 0) {
                                ip1dbg((
                                    "ip_output_options: bad option offset\n"));
                                code = (char *)&opt[IPOPT_OLEN] -
                                    (char *)ipha;
                                goto param_prob;
                        }
                        break;
                case IPOPT_TS:
                        /*
                         * Verify that length >=5 and that there is either
                         * room for another timestamp or that the overflow
                         * counter is not maxed out.
                         */
                        code = (char *)&opt[IPOPT_OLEN] - (char *)ipha;
                        if (optlen < IPOPT_MINLEN_IT) {
                                goto param_prob;
                        }
                        if ((opts.ipoptp_flags & IPOPTP_ERROR) != 0) {
                                ip1dbg((
                                    "ip_output_options: bad option offset\n"));
                                code = (char *)&opt[IPOPT_OFFSET] -
                                    (char *)ipha;
                                goto param_prob;
                        }
                        switch (opt[IPOPT_POS_OV_FLG] & 0x0F) {
                        case IPOPT_TS_TSONLY:
                                off = IPOPT_TS_TIMELEN;
                                break;
                        case IPOPT_TS_TSANDADDR:
                        case IPOPT_TS_PRESPEC:
                        case IPOPT_TS_PRESPEC_RFC791:
                                off = IP_ADDR_LEN + IPOPT_TS_TIMELEN;
                                break;
                        default:
                                code = (char *)&opt[IPOPT_POS_OV_FLG] -
                                    (char *)ipha;
                                goto param_prob;
                        }
                        if (opt[IPOPT_OFFSET] - 1 + off > optlen &&
                            (opt[IPOPT_POS_OV_FLG] & 0xF0) == 0xF0) {
                                /*
                                 * No room and the overflow counter is 15
                                 * already.
                                 */
                                goto param_prob;
                        }
                        break;
                }
        }

        if ((opts.ipoptp_flags & IPOPTP_ERROR) == 0)
                return (0);

        ip1dbg(("ip_output_options: error processing IP options."));
        code = (char *)&opt[IPOPT_OFFSET] - (char *)ipha;

param_prob:
        bzero(&iras, sizeof (iras));
        iras.ira_ill = iras.ira_rill = ill;
        iras.ira_ruifindex = ill->ill_phyint->phyint_ifindex;
        iras.ira_rifindex = iras.ira_ruifindex;
        iras.ira_flags = IRAF_IS_IPV4;

        ip_drop_output("ip_output_options", mp, ill);
        icmp_param_problem(mp, (uint8_t)code, &iras);
        ASSERT(!(iras.ira_flags & IRAF_IPSEC_SECURE));
        return (-1);

bad_src_route:
        bzero(&iras, sizeof (iras));
        iras.ira_ill = iras.ira_rill = ill;
        iras.ira_ruifindex = ill->ill_phyint->phyint_ifindex;
        iras.ira_rifindex = iras.ira_ruifindex;
        iras.ira_flags = IRAF_IS_IPV4;

        ip_drop_input("ICMP_SOURCE_ROUTE_FAILED", mp, ill);
        icmp_unreachable(mp, ICMP_SOURCE_ROUTE_FAILED, &iras);
        ASSERT(!(iras.ira_flags & IRAF_IPSEC_SECURE));
        return (-1);
}

/*
 * The maximum value of conn_drain_list_cnt is CONN_MAXDRAINCNT.
 * conn_drain_list_cnt can be changed by setting conn_drain_nthreads
 * thru /etc/system.
 */
#define CONN_MAXDRAINCNT        64

static void
conn_drain_init(ip_stack_t *ipst)
{
        int i, j;
        idl_tx_list_t *itl_tx;

        ipst->ips_conn_drain_list_cnt = conn_drain_nthreads;

        if ((ipst->ips_conn_drain_list_cnt == 0) ||
            (ipst->ips_conn_drain_list_cnt > CONN_MAXDRAINCNT)) {
                /*
                 * Default value of the number of drainers is the
                 * number of cpus, subject to maximum of 8 drainers.
                 */
                if (boot_max_ncpus != -1)
                        ipst->ips_conn_drain_list_cnt = MIN(boot_max_ncpus, 8);
                else
                        ipst->ips_conn_drain_list_cnt = MIN(max_ncpus, 8);
        }

        ipst->ips_idl_tx_list =
            kmem_zalloc(TX_FANOUT_SIZE * sizeof (idl_tx_list_t), KM_SLEEP);
        for (i = 0; i < TX_FANOUT_SIZE; i++) {
                itl_tx =  &ipst->ips_idl_tx_list[i];
                itl_tx->txl_drain_list =
                    kmem_zalloc(ipst->ips_conn_drain_list_cnt *
                    sizeof (idl_t), KM_SLEEP);
                mutex_init(&itl_tx->txl_lock, NULL, MUTEX_DEFAULT, NULL);
                for (j = 0; j < ipst->ips_conn_drain_list_cnt; j++) {
                        mutex_init(&itl_tx->txl_drain_list[j].idl_lock, NULL,
                            MUTEX_DEFAULT, NULL);
                        itl_tx->txl_drain_list[j].idl_itl = itl_tx;
                }
        }
}

static void
conn_drain_fini(ip_stack_t *ipst)
{
        int i;
        idl_tx_list_t *itl_tx;

        for (i = 0; i < TX_FANOUT_SIZE; i++) {
                itl_tx =  &ipst->ips_idl_tx_list[i];
                kmem_free(itl_tx->txl_drain_list,
                    ipst->ips_conn_drain_list_cnt * sizeof (idl_t));
        }
        kmem_free(ipst->ips_idl_tx_list,
            TX_FANOUT_SIZE * sizeof (idl_tx_list_t));
        ipst->ips_idl_tx_list = NULL;
}

/*
 * Flow control has blocked us from proceeding.  Insert the given conn in one
 * of the conn drain lists.  When flow control is unblocked, either ip_wsrv()
 * (STREAMS) or ill_flow_enable() (direct) will be called back, which in turn
 * will call conn_walk_drain().  See the flow control notes at the top of this
 * file for more details.
 */
void
conn_drain_insert(conn_t *connp, idl_tx_list_t *tx_list)
{
        idl_t   *idl = tx_list->txl_drain_list;
        uint_t  index;
        ip_stack_t      *ipst = connp->conn_netstack->netstack_ip;

        mutex_enter(&connp->conn_lock);
        if (connp->conn_state_flags & CONN_CLOSING) {
                /*
                 * The conn is closing as a result of which CONN_CLOSING
                 * is set. Return.
                 */
                mutex_exit(&connp->conn_lock);
                return;
        } else if (connp->conn_idl == NULL) {
                /*
                 * Assign the next drain list round robin. We dont' use
                 * a lock, and thus it may not be strictly round robin.
                 * Atomicity of load/stores is enough to make sure that
                 * conn_drain_list_index is always within bounds.
                 */
                index = tx_list->txl_drain_index;
                ASSERT(index < ipst->ips_conn_drain_list_cnt);
                connp->conn_idl = &tx_list->txl_drain_list[index];
                index++;
                if (index == ipst->ips_conn_drain_list_cnt)
                        index = 0;
                tx_list->txl_drain_index = index;
        } else {
                ASSERT(connp->conn_idl->idl_itl == tx_list);
        }
        mutex_exit(&connp->conn_lock);

        idl = connp->conn_idl;
        mutex_enter(&idl->idl_lock);
        if ((connp->conn_drain_prev != NULL) ||
            (connp->conn_state_flags & CONN_CLOSING)) {
                /*
                 * The conn is either already in the drain list or closing.
                 * (We needed to check for CONN_CLOSING again since close can
                 * sneak in between dropping conn_lock and acquiring idl_lock.)
                 */
                mutex_exit(&idl->idl_lock);
                return;
        }

        /*
         * The conn is not in the drain list. Insert it at the
         * tail of the drain list. The drain list is circular
         * and doubly linked. idl_conn points to the 1st element
         * in the list.
         */
        if (idl->idl_conn == NULL) {
                idl->idl_conn = connp;
                connp->conn_drain_next = connp;
                connp->conn_drain_prev = connp;
        } else {
                conn_t *head = idl->idl_conn;

                connp->conn_drain_next = head;
                connp->conn_drain_prev = head->conn_drain_prev;
                head->conn_drain_prev->conn_drain_next = connp;
                head->conn_drain_prev = connp;
        }
        /*
         * For non streams based sockets assert flow control.
         */
        conn_setqfull(connp, NULL);
        mutex_exit(&idl->idl_lock);
}

static void
conn_drain_remove(conn_t *connp)
{
        idl_t *idl = connp->conn_idl;

        if (idl != NULL) {
                /*
                 * Remove ourself from the drain list.
                 */
                if (connp->conn_drain_next == connp) {
                        /* Singleton in the list */
                        ASSERT(connp->conn_drain_prev == connp);
                        idl->idl_conn = NULL;
                } else {
                        connp->conn_drain_prev->conn_drain_next =
                            connp->conn_drain_next;
                        connp->conn_drain_next->conn_drain_prev =
                            connp->conn_drain_prev;
                        if (idl->idl_conn == connp)
                                idl->idl_conn = connp->conn_drain_next;
                }

                /*
                 * NOTE: because conn_idl is associated with a specific drain
                 * list which in turn is tied to the index the TX ring
                 * (txl_cookie) hashes to, and because the TX ring can change
                 * over the lifetime of the conn_t, we must clear conn_idl so
                 * a subsequent conn_drain_insert() will set conn_idl again
                 * based on the latest txl_cookie.
                 */
                connp->conn_idl = NULL;
        }
        connp->conn_drain_next = NULL;
        connp->conn_drain_prev = NULL;

        conn_clrqfull(connp, NULL);
        /*
         * For streams based sockets open up flow control.
         */
        if (!IPCL_IS_NONSTR(connp))
                enableok(connp->conn_wq);
}

/*
 * This conn is closing, and we are called from ip_close. OR
 * this conn is draining because flow-control on the ill has been relieved.
 *
 * We must also need to remove conn's on this idl from the list, and also
 * inform the sockfs upcalls about the change in flow-control.
 */
static void
conn_drain(conn_t *connp, boolean_t closing)
{
        idl_t *idl;
        conn_t *next_connp;

        /*
         * connp->conn_idl is stable at this point, and no lock is needed
         * to check it. If we are called from ip_close, close has already
         * set CONN_CLOSING, thus freezing the value of conn_idl, and
         * called us only because conn_idl is non-null. If we are called thru
         * service, conn_idl could be null, but it cannot change because
         * service is single-threaded per queue, and there cannot be another
         * instance of service trying to call conn_drain_insert on this conn
         * now.
         */
        ASSERT(!closing || connp == NULL || connp->conn_idl != NULL);

        /*
         * If the conn doesn't exist or is not on a drain list, bail.
         */
        if (connp == NULL || connp->conn_idl == NULL ||
            connp->conn_drain_prev == NULL) {
                return;
        }

        idl = connp->conn_idl;
        ASSERT(MUTEX_HELD(&idl->idl_lock));

        if (!closing) {
                next_connp = connp->conn_drain_next;
                while (next_connp != connp) {
                        conn_t *delconnp = next_connp;

                        next_connp = next_connp->conn_drain_next;
                        conn_drain_remove(delconnp);
                }
                ASSERT(connp->conn_drain_next == idl->idl_conn);
        }
        conn_drain_remove(connp);
}

/*
 * Write service routine. Shared perimeter entry point.
 * The device queue's messages has fallen below the low water mark and STREAMS
 * has backenabled the ill_wq. Send sockfs notification about flow-control on
 * each waiting conn.
 */
int
ip_wsrv(queue_t *q)
{
        ill_t   *ill;

        ill = (ill_t *)q->q_ptr;
        if (ill->ill_state_flags == 0) {
                ip_stack_t *ipst = ill->ill_ipst;

                /*
                 * The device flow control has opened up.
                 * Walk through conn drain lists and qenable the
                 * first conn in each list. This makes sense only
                 * if the stream is fully plumbed and setup.
                 * Hence the ill_state_flags check above.
                 */
                ip1dbg(("ip_wsrv: walking\n"));
                conn_walk_drain(ipst, &ipst->ips_idl_tx_list[0]);
                enableok(ill->ill_wq);
        }
        return (0);
}

/*
 * Callback to disable flow control in IP.
 *
 * This is a mac client callback added when the DLD_CAPAB_DIRECT capability
 * is enabled.
 *
 * When MAC_TX() is not able to send any more packets, dld sets its queue
 * to QFULL and enable the STREAMS flow control. Later, when the underlying
 * driver is able to continue to send packets, it calls mac_tx_(ring_)update()
 * function and wakes up corresponding mac worker threads, which in turn
 * calls this callback function, and disables flow control.
 */
void
ill_flow_enable(void *arg, ip_mac_tx_cookie_t cookie)
{
        ill_t *ill = (ill_t *)arg;
        ip_stack_t *ipst = ill->ill_ipst;
        idl_tx_list_t *idl_txl;

        idl_txl = &ipst->ips_idl_tx_list[IDLHASHINDEX(cookie)];
        mutex_enter(&idl_txl->txl_lock);
        /* add code to to set a flag to indicate idl_txl is enabled */
        conn_walk_drain(ipst, idl_txl);
        mutex_exit(&idl_txl->txl_lock);
}

/*
 * Flow control has been relieved and STREAMS has backenabled us; drain
 * all the conn lists on `tx_list'.
 */
static void
conn_walk_drain(ip_stack_t *ipst, idl_tx_list_t *tx_list)
{
        int i;
        idl_t *idl;

        IP_STAT(ipst, ip_conn_walk_drain);

        for (i = 0; i < ipst->ips_conn_drain_list_cnt; i++) {
                idl = &tx_list->txl_drain_list[i];
                mutex_enter(&idl->idl_lock);
                conn_drain(idl->idl_conn, B_FALSE);
                mutex_exit(&idl->idl_lock);
        }
}

/*
 * Determine if the ill and multicast aspects of that packets
 * "matches" the conn.
 */
boolean_t
conn_wantpacket(conn_t *connp, ip_recv_attr_t *ira, ipha_t *ipha)
{
        ill_t           *ill = ira->ira_rill;
        zoneid_t        zoneid = ira->ira_zoneid;
        uint_t          in_ifindex;
        ipaddr_t        dst, src;

        dst = ipha->ipha_dst;
        src = ipha->ipha_src;

        /*
         * conn_incoming_ifindex is set by IP_BOUND_IF which limits
         * unicast, broadcast and multicast reception to
         * conn_incoming_ifindex.
         * conn_wantpacket is called for unicast, broadcast and
         * multicast packets.
         */
        in_ifindex = connp->conn_incoming_ifindex;

        /* mpathd can bind to the under IPMP interface, which we allow */
        if (in_ifindex != 0 && in_ifindex != ill->ill_phyint->phyint_ifindex) {
                if (!IS_UNDER_IPMP(ill))
                        return (B_FALSE);

                if (in_ifindex != ipmp_ill_get_ipmp_ifindex(ill))
                        return (B_FALSE);
        }

        if (!IPCL_ZONE_MATCH(connp, zoneid))
                return (B_FALSE);

        if (!(ira->ira_flags & IRAF_MULTICAST))
                return (B_TRUE);

        if (connp->conn_multi_router) {
                /* multicast packet and multicast router socket: send up */
                return (B_TRUE);
        }

        if (ipha->ipha_protocol == IPPROTO_PIM ||
            ipha->ipha_protocol == IPPROTO_RSVP)
                return (B_TRUE);

        return (conn_hasmembers_ill_withsrc_v4(connp, dst, src, ira->ira_ill));
}

void
conn_setqfull(conn_t *connp, boolean_t *flow_stopped)
{
        if (IPCL_IS_NONSTR(connp)) {
                (*connp->conn_upcalls->su_txq_full)
                    (connp->conn_upper_handle, B_TRUE);
                if (flow_stopped != NULL)
                        *flow_stopped = B_TRUE;
        } else {
                queue_t *q = connp->conn_wq;

                ASSERT(q != NULL);
                if (!(q->q_flag & QFULL)) {
                        mutex_enter(QLOCK(q));
                        if (!(q->q_flag & QFULL)) {
                                /* still need to set QFULL */
                                q->q_flag |= QFULL;
                                /* set flow_stopped to true under QLOCK */
                                if (flow_stopped != NULL)
                                        *flow_stopped = B_TRUE;
                                mutex_exit(QLOCK(q));
                        } else {
                                /* flow_stopped is left unchanged */
                                mutex_exit(QLOCK(q));
                        }
                }
        }
}

void
conn_clrqfull(conn_t *connp, boolean_t *flow_stopped)
{
        if (IPCL_IS_NONSTR(connp)) {
                (*connp->conn_upcalls->su_txq_full)
                    (connp->conn_upper_handle, B_FALSE);
                if (flow_stopped != NULL)
                        *flow_stopped = B_FALSE;
        } else {
                queue_t *q = connp->conn_wq;

                ASSERT(q != NULL);
                if (q->q_flag & QFULL) {
                        mutex_enter(QLOCK(q));
                        if (q->q_flag & QFULL) {
                                q->q_flag &= ~QFULL;
                                /* set flow_stopped to false under QLOCK */
                                if (flow_stopped != NULL)
                                        *flow_stopped = B_FALSE;
                                mutex_exit(QLOCK(q));
                                if (q->q_flag & QWANTW)
                                        qbackenable(q, 0);
                        } else {
                                /* flow_stopped is left unchanged */
                                mutex_exit(QLOCK(q));
                        }
                }
        }

        mutex_enter(&connp->conn_lock);
        connp->conn_blocked = B_FALSE;
        mutex_exit(&connp->conn_lock);
}

/*
 * Return the length in bytes of the IPv4 headers (base header and IP options)
 * that will be needed based on the ip_pkt_t structure passed by the caller.
 *
 * The returned length does not include the length of the upper level
 * protocol (ULP) header.
 * The caller needs to check that the length doesn't exceed the max for IPv4.
 */
int
ip_total_hdrs_len_v4(const ip_pkt_t *ipp)
{
        int len;

        len = IP_SIMPLE_HDR_LENGTH;

        if (ipp->ipp_fields & IPPF_IPV4_OPTIONS) {
                ASSERT(ipp->ipp_ipv4_options_len != 0);
                ASSERT((ipp->ipp_ipv4_options_len & 3) == 0);
                len += ipp->ipp_ipv4_options_len;
        }
        return (len);
}

/*
 * All-purpose routine to build an IPv4 header with options based
 * on the abstract ip_pkt_t.
 *
 * The caller has to set the source and destination address as well as
 * ipha_length. The caller has to massage any source route and compensate
 * for the ULP pseudo-header checksum due to the source route.
 */
void
ip_build_hdrs_v4(uchar_t *buf, uint_t buf_len, const ip_pkt_t *ipp,
    uint8_t protocol)
{
        ipha_t  *ipha = (ipha_t *)buf;
        uint8_t *cp;

        /* Initialize IPv4 header */
        ipha->ipha_type_of_service = ipp->ipp_type_of_service;
        ipha->ipha_length = 0;  /* Caller will set later */
        ipha->ipha_ident = 0;
        ipha->ipha_fragment_offset_and_flags = 0;
        ipha->ipha_ttl = ipp->ipp_unicast_hops;
        ipha->ipha_protocol = protocol;
        ipha->ipha_hdr_checksum = 0;

        if ((ipp->ipp_fields & IPPF_ADDR) &&
            IN6_IS_ADDR_V4MAPPED(&ipp->ipp_addr))
                ipha->ipha_src = ipp->ipp_addr_v4;

        cp = (uint8_t *)&ipha[1];

        if (ipp->ipp_fields & IPPF_IPV4_OPTIONS) {
                ASSERT(ipp->ipp_ipv4_options_len != 0);
                ASSERT((ipp->ipp_ipv4_options_len & 3) == 0);
                bcopy(ipp->ipp_ipv4_options, cp, ipp->ipp_ipv4_options_len);
                cp += ipp->ipp_ipv4_options_len;
        }
        ipha->ipha_version_and_hdr_length =
            (uint8_t)((IP_VERSION << 4) + buf_len / 4);

        ASSERT((int)(cp - buf) == buf_len);
}

/* Allocate the private structure */
static int
ip_priv_alloc(void **bufp)
{
        void    *buf;

        if ((buf = kmem_alloc(sizeof (ip_priv_t), KM_NOSLEEP)) == NULL)
                return (ENOMEM);

        *bufp = buf;
        return (0);
}

/* Function to delete the private structure */
void
ip_priv_free(void *buf)
{
        ASSERT(buf != NULL);
        kmem_free(buf, sizeof (ip_priv_t));
}

/*
 * The entry point for IPPF processing.
 * If the classifier (IPGPC_CLASSIFY) is not loaded and configured, the
 * routine just returns.
 *
 * When called, ip_process generates an ipp_packet_t structure
 * which holds the state information for this packet and invokes the
 * the classifier (via ipp_packet_process). The classification, depending on
 * configured filters, results in a list of actions for this packet. Invoking
 * an action may cause the packet to be dropped, in which case we return NULL.
 * proc indicates the callout position for
 * this packet and ill is the interface this packet arrived on or will leave
 * on (inbound and outbound resp.).
 *
 * We do the processing on the rill (mapped to the upper if ipmp), but MIB
 * on the ill corrsponding to the destination IP address.
 */
mblk_t *
ip_process(ip_proc_t proc, mblk_t *mp, ill_t *rill, ill_t *ill)
{
        ip_priv_t       *priv;
        ipp_action_id_t aid;
        int             rc = 0;
        ipp_packet_t    *pp;

        /* If the classifier is not loaded, return  */
        if ((aid = ipp_action_lookup(IPGPC_CLASSIFY)) == IPP_ACTION_INVAL) {
                return (mp);
        }

        ASSERT(mp != NULL);

        /* Allocate the packet structure */
        rc = ipp_packet_alloc(&pp, "ip", aid);
        if (rc != 0)
                goto drop;

        /* Allocate the private structure */
        rc = ip_priv_alloc((void **)&priv);
        if (rc != 0) {
                ipp_packet_free(pp);
                goto drop;
        }
        priv->proc = proc;
        priv->ill_index = ill_get_upper_ifindex(rill);

        ipp_packet_set_private(pp, priv, ip_priv_free);
        ipp_packet_set_data(pp, mp);

        /* Invoke the classifier */
        rc = ipp_packet_process(&pp);
        if (pp != NULL) {
                mp = ipp_packet_get_data(pp);
                ipp_packet_free(pp);
                if (rc != 0)
                        goto drop;
                return (mp);
        } else {
                /* No mp to trace in ip_drop_input/ip_drop_output  */
                mp = NULL;
        }
drop:
        if (proc == IPP_LOCAL_IN || proc == IPP_FWD_IN) {
                BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                ip_drop_input("ip_process", mp, ill);
        } else {
                BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutDiscards);
                ip_drop_output("ip_process", mp, ill);
        }
        freemsg(mp);
        return (NULL);
}

static int
ip_squeue_switch(int val)
{
        int rval;

        switch (val) {
        case IP_SQUEUE_ENTER_NODRAIN:
                rval = SQ_NODRAIN;
                break;
        case IP_SQUEUE_ENTER:
                rval = SQ_PROCESS;
                break;
        case IP_SQUEUE_FILL:
        default:
                rval = SQ_FILL;
                break;
        }
        return (rval);
}

static void *
ip_kstat2_init(netstackid_t stackid, ip_stat_t *ip_statisticsp)
{
        kstat_t *ksp;

        ip_stat_t template = {
                { "ip_udp_fannorm",             KSTAT_DATA_UINT64 },
                { "ip_udp_fanmb",               KSTAT_DATA_UINT64 },
                { "ip_recv_pullup",             KSTAT_DATA_UINT64 },
                { "ip_db_ref",                  KSTAT_DATA_UINT64 },
                { "ip_notaligned",              KSTAT_DATA_UINT64 },
                { "ip_multimblk",               KSTAT_DATA_UINT64 },
                { "ip_opt",                     KSTAT_DATA_UINT64 },
                { "ipsec_proto_ahesp",          KSTAT_DATA_UINT64 },
                { "ip_conn_flputbq",            KSTAT_DATA_UINT64 },
                { "ip_conn_walk_drain",         KSTAT_DATA_UINT64 },
                { "ip_out_sw_cksum",            KSTAT_DATA_UINT64 },
                { "ip_out_sw_cksum_bytes",      KSTAT_DATA_UINT64 },
                { "ip_in_sw_cksum",             KSTAT_DATA_UINT64 },
                { "ip_ire_reclaim_calls",       KSTAT_DATA_UINT64 },
                { "ip_ire_reclaim_deleted",     KSTAT_DATA_UINT64 },
                { "ip_nce_reclaim_calls",       KSTAT_DATA_UINT64 },
                { "ip_nce_reclaim_deleted",     KSTAT_DATA_UINT64 },
                { "ip_dce_reclaim_calls",       KSTAT_DATA_UINT64 },
                { "ip_dce_reclaim_deleted",     KSTAT_DATA_UINT64 },
                { "ip_tcp_in_full_hw_cksum_err",        KSTAT_DATA_UINT64 },
                { "ip_tcp_in_part_hw_cksum_err",        KSTAT_DATA_UINT64 },
                { "ip_tcp_in_sw_cksum_err",             KSTAT_DATA_UINT64 },
                { "ip_udp_in_full_hw_cksum_err",        KSTAT_DATA_UINT64 },
                { "ip_udp_in_part_hw_cksum_err",        KSTAT_DATA_UINT64 },
                { "ip_udp_in_sw_cksum_err",     KSTAT_DATA_UINT64 },
                { "conn_in_recvdstaddr",        KSTAT_DATA_UINT64 },
                { "conn_in_recvopts",           KSTAT_DATA_UINT64 },
                { "conn_in_recvif",             KSTAT_DATA_UINT64 },
                { "conn_in_recvslla",           KSTAT_DATA_UINT64 },
                { "conn_in_recvucred",          KSTAT_DATA_UINT64 },
                { "conn_in_recvttl",            KSTAT_DATA_UINT64 },
                { "conn_in_recvhopopts",        KSTAT_DATA_UINT64 },
                { "conn_in_recvhoplimit",       KSTAT_DATA_UINT64 },
                { "conn_in_recvdstopts",        KSTAT_DATA_UINT64 },
                { "conn_in_recvrthdrdstopts",   KSTAT_DATA_UINT64 },
                { "conn_in_recvrthdr",          KSTAT_DATA_UINT64 },
                { "conn_in_recvpktinfo",        KSTAT_DATA_UINT64 },
                { "conn_in_recvtclass",         KSTAT_DATA_UINT64 },
                { "conn_in_timestamp",          KSTAT_DATA_UINT64 },
        };

        ksp = kstat_create_netstack("ip", 0, "ipstat", "net",
            KSTAT_TYPE_NAMED, sizeof (template) / sizeof (kstat_named_t),
            KSTAT_FLAG_VIRTUAL, stackid);

        if (ksp == NULL)
                return (NULL);

        bcopy(&template, ip_statisticsp, sizeof (template));
        ksp->ks_data = (void *)ip_statisticsp;
        ksp->ks_private = (void *)(uintptr_t)stackid;

        kstat_install(ksp);
        return (ksp);
}

static void
ip_kstat2_fini(netstackid_t stackid, kstat_t *ksp)
{
        if (ksp != NULL) {
                ASSERT(stackid == (netstackid_t)(uintptr_t)ksp->ks_private);
                kstat_delete_netstack(ksp, stackid);
        }
}

static void *
ip_kstat_init(netstackid_t stackid, ip_stack_t *ipst)
{
        kstat_t *ksp;

        ip_named_kstat_t template = {
                { "forwarding",         KSTAT_DATA_UINT32, 0 },
                { "defaultTTL",         KSTAT_DATA_UINT32, 0 },
                { "inReceives",         KSTAT_DATA_UINT64, 0 },
                { "inHdrErrors",        KSTAT_DATA_UINT32, 0 },
                { "inAddrErrors",       KSTAT_DATA_UINT32, 0 },
                { "forwDatagrams",      KSTAT_DATA_UINT64, 0 },
                { "inUnknownProtos",    KSTAT_DATA_UINT32, 0 },
                { "inDiscards",         KSTAT_DATA_UINT32, 0 },
                { "inDelivers",         KSTAT_DATA_UINT64, 0 },
                { "outRequests",        KSTAT_DATA_UINT64, 0 },
                { "outDiscards",        KSTAT_DATA_UINT32, 0 },
                { "outNoRoutes",        KSTAT_DATA_UINT32, 0 },
                { "reasmTimeout",       KSTAT_DATA_UINT32, 0 },
                { "reasmReqds",         KSTAT_DATA_UINT32, 0 },
                { "reasmOKs",           KSTAT_DATA_UINT32, 0 },
                { "reasmFails",         KSTAT_DATA_UINT32, 0 },
                { "fragOKs",            KSTAT_DATA_UINT32, 0 },
                { "fragFails",          KSTAT_DATA_UINT32, 0 },
                { "fragCreates",        KSTAT_DATA_UINT32, 0 },
                { "addrEntrySize",      KSTAT_DATA_INT32, 0 },
                { "routeEntrySize",     KSTAT_DATA_INT32, 0 },
                { "netToMediaEntrySize",        KSTAT_DATA_INT32, 0 },
                { "routingDiscards",    KSTAT_DATA_UINT32, 0 },
                { "inErrs",             KSTAT_DATA_UINT32, 0 },
                { "noPorts",            KSTAT_DATA_UINT32, 0 },
                { "inCksumErrs",        KSTAT_DATA_UINT32, 0 },
                { "reasmDuplicates",    KSTAT_DATA_UINT32, 0 },
                { "reasmPartDups",      KSTAT_DATA_UINT32, 0 },
                { "forwProhibits",      KSTAT_DATA_UINT32, 0 },
                { "udpInCksumErrs",     KSTAT_DATA_UINT32, 0 },
                { "udpInOverflows",     KSTAT_DATA_UINT32, 0 },
                { "rawipInOverflows",   KSTAT_DATA_UINT32, 0 },
                { "ipsecInSucceeded",   KSTAT_DATA_UINT32, 0 },
                { "ipsecInFailed",      KSTAT_DATA_INT32, 0 },
                { "memberEntrySize",    KSTAT_DATA_INT32, 0 },
                { "inIPv6",             KSTAT_DATA_UINT32, 0 },
                { "outIPv6",            KSTAT_DATA_UINT32, 0 },
                { "outSwitchIPv6",      KSTAT_DATA_UINT32, 0 },
        };

        ksp = kstat_create_netstack("ip", 0, "ip", "mib2", KSTAT_TYPE_NAMED,
            NUM_OF_FIELDS(ip_named_kstat_t), 0, stackid);
        if (ksp == NULL || ksp->ks_data == NULL)
                return (NULL);

        template.forwarding.value.ui32 = WE_ARE_FORWARDING(ipst) ? 1:2;
        template.defaultTTL.value.ui32 = (uint32_t)ipst->ips_ip_def_ttl;
        template.reasmTimeout.value.ui32 = ipst->ips_ip_reassembly_timeout;
        template.addrEntrySize.value.i32 = sizeof (mib2_ipAddrEntry_t);
        template.routeEntrySize.value.i32 = sizeof (mib2_ipRouteEntry_t);

        template.netToMediaEntrySize.value.i32 =
            sizeof (mib2_ipNetToMediaEntry_t);

        template.memberEntrySize.value.i32 = sizeof (ipv6_member_t);

        bcopy(&template, ksp->ks_data, sizeof (template));
        ksp->ks_update = ip_kstat_update;
        ksp->ks_private = (void *)(uintptr_t)stackid;

        kstat_install(ksp);
        return (ksp);
}

static void
ip_kstat_fini(netstackid_t stackid, kstat_t *ksp)
{
        if (ksp != NULL) {
                ASSERT(stackid == (netstackid_t)(uintptr_t)ksp->ks_private);
                kstat_delete_netstack(ksp, stackid);
        }
}

static int
ip_kstat_update(kstat_t *kp, int rw)
{
        ip_named_kstat_t *ipkp;
        mib2_ipIfStatsEntry_t ipmib;
        ill_walk_context_t ctx;
        ill_t *ill;
        netstackid_t    stackid = (zoneid_t)(uintptr_t)kp->ks_private;
        netstack_t      *ns;
        ip_stack_t      *ipst;

        if (kp == NULL || kp->ks_data == NULL)
                return (EIO);

        if (rw == KSTAT_WRITE)
                return (EACCES);

        ns = netstack_find_by_stackid(stackid);
        if (ns == NULL)
                return (-1);
        ipst = ns->netstack_ip;
        if (ipst == NULL) {
                netstack_rele(ns);
                return (-1);
        }
        ipkp = (ip_named_kstat_t *)kp->ks_data;

        bcopy(&ipst->ips_ip_mib, &ipmib, sizeof (ipmib));
        rw_enter(&ipst->ips_ill_g_lock, RW_READER);
        ill = ILL_START_WALK_V4(&ctx, ipst);
        for (; ill != NULL; ill = ill_next(&ctx, ill))
                ip_mib2_add_ip_stats(&ipmib, ill->ill_ip_mib);
        rw_exit(&ipst->ips_ill_g_lock);

        ipkp->forwarding.value.ui32 =           ipmib.ipIfStatsForwarding;
        ipkp->defaultTTL.value.ui32 =           ipmib.ipIfStatsDefaultTTL;
        ipkp->inReceives.value.ui64 =           ipmib.ipIfStatsHCInReceives;
        ipkp->inHdrErrors.value.ui32 =          ipmib.ipIfStatsInHdrErrors;
        ipkp->inAddrErrors.value.ui32 =         ipmib.ipIfStatsInAddrErrors;
        ipkp->forwDatagrams.value.ui64 = ipmib.ipIfStatsHCOutForwDatagrams;
        ipkp->inUnknownProtos.value.ui32 =      ipmib.ipIfStatsInUnknownProtos;
        ipkp->inDiscards.value.ui32 =           ipmib.ipIfStatsInDiscards;
        ipkp->inDelivers.value.ui64 =           ipmib.ipIfStatsHCInDelivers;
        ipkp->outRequests.value.ui64 =          ipmib.ipIfStatsHCOutRequests;
        ipkp->outDiscards.value.ui32 =          ipmib.ipIfStatsOutDiscards;
        ipkp->outNoRoutes.value.ui32 =          ipmib.ipIfStatsOutNoRoutes;
        ipkp->reasmTimeout.value.ui32 =         ipst->ips_ip_reassembly_timeout;
        ipkp->reasmReqds.value.ui32 =           ipmib.ipIfStatsReasmReqds;
        ipkp->reasmOKs.value.ui32 =             ipmib.ipIfStatsReasmOKs;
        ipkp->reasmFails.value.ui32 =           ipmib.ipIfStatsReasmFails;
        ipkp->fragOKs.value.ui32 =              ipmib.ipIfStatsOutFragOKs;
        ipkp->fragFails.value.ui32 =            ipmib.ipIfStatsOutFragFails;
        ipkp->fragCreates.value.ui32 =          ipmib.ipIfStatsOutFragCreates;

        ipkp->routingDiscards.value.ui32 =      0;
        ipkp->inErrs.value.ui32 =               ipmib.tcpIfStatsInErrs;
        ipkp->noPorts.value.ui32 =              ipmib.udpIfStatsNoPorts;
        ipkp->inCksumErrs.value.ui32 =          ipmib.ipIfStatsInCksumErrs;
        ipkp->reasmDuplicates.value.ui32 =      ipmib.ipIfStatsReasmDuplicates;
        ipkp->reasmPartDups.value.ui32 =        ipmib.ipIfStatsReasmPartDups;
        ipkp->forwProhibits.value.ui32 =        ipmib.ipIfStatsForwProhibits;
        ipkp->udpInCksumErrs.value.ui32 =       ipmib.udpIfStatsInCksumErrs;
        ipkp->udpInOverflows.value.ui32 =       ipmib.udpIfStatsInOverflows;
        ipkp->rawipInOverflows.value.ui32 =     ipmib.rawipIfStatsInOverflows;
        ipkp->ipsecInSucceeded.value.ui32 =     ipmib.ipsecIfStatsInSucceeded;
        ipkp->ipsecInFailed.value.i32 =         ipmib.ipsecIfStatsInFailed;

        ipkp->inIPv6.value.ui32 =       ipmib.ipIfStatsInWrongIPVersion;
        ipkp->outIPv6.value.ui32 =      ipmib.ipIfStatsOutWrongIPVersion;
        ipkp->outSwitchIPv6.value.ui32 = ipmib.ipIfStatsOutSwitchIPVersion;

        netstack_rele(ns);

        return (0);
}

static void *
icmp_kstat_init(netstackid_t stackid)
{
        kstat_t *ksp;

        icmp_named_kstat_t template = {
                { "inMsgs",             KSTAT_DATA_UINT32 },
                { "inErrors",           KSTAT_DATA_UINT32 },
                { "inDestUnreachs",     KSTAT_DATA_UINT32 },
                { "inTimeExcds",        KSTAT_DATA_UINT32 },
                { "inParmProbs",        KSTAT_DATA_UINT32 },
                { "inSrcQuenchs",       KSTAT_DATA_UINT32 },
                { "inRedirects",        KSTAT_DATA_UINT32 },
                { "inEchos",            KSTAT_DATA_UINT32 },
                { "inEchoReps",         KSTAT_DATA_UINT32 },
                { "inTimestamps",       KSTAT_DATA_UINT32 },
                { "inTimestampReps",    KSTAT_DATA_UINT32 },
                { "inAddrMasks",        KSTAT_DATA_UINT32 },
                { "inAddrMaskReps",     KSTAT_DATA_UINT32 },
                { "outMsgs",            KSTAT_DATA_UINT32 },
                { "outErrors",          KSTAT_DATA_UINT32 },
                { "outDestUnreachs",    KSTAT_DATA_UINT32 },
                { "outTimeExcds",       KSTAT_DATA_UINT32 },
                { "outParmProbs",       KSTAT_DATA_UINT32 },
                { "outSrcQuenchs",      KSTAT_DATA_UINT32 },
                { "outRedirects",       KSTAT_DATA_UINT32 },
                { "outEchos",           KSTAT_DATA_UINT32 },
                { "outEchoReps",        KSTAT_DATA_UINT32 },
                { "outTimestamps",      KSTAT_DATA_UINT32 },
                { "outTimestampReps",   KSTAT_DATA_UINT32 },
                { "outAddrMasks",       KSTAT_DATA_UINT32 },
                { "outAddrMaskReps",    KSTAT_DATA_UINT32 },
                { "inChksumErrs",       KSTAT_DATA_UINT32 },
                { "inUnknowns",         KSTAT_DATA_UINT32 },
                { "inFragNeeded",       KSTAT_DATA_UINT32 },
                { "outFragNeeded",      KSTAT_DATA_UINT32 },
                { "outDrops",           KSTAT_DATA_UINT32 },
                { "inOverFlows",        KSTAT_DATA_UINT32 },
                { "inBadRedirects",     KSTAT_DATA_UINT32 },
        };

        ksp = kstat_create_netstack("ip", 0, "icmp", "mib2", KSTAT_TYPE_NAMED,
            NUM_OF_FIELDS(icmp_named_kstat_t), 0, stackid);
        if (ksp == NULL || ksp->ks_data == NULL)
                return (NULL);

        bcopy(&template, ksp->ks_data, sizeof (template));

        ksp->ks_update = icmp_kstat_update;
        ksp->ks_private = (void *)(uintptr_t)stackid;

        kstat_install(ksp);
        return (ksp);
}

static void
icmp_kstat_fini(netstackid_t stackid, kstat_t *ksp)
{
        if (ksp != NULL) {
                ASSERT(stackid == (netstackid_t)(uintptr_t)ksp->ks_private);
                kstat_delete_netstack(ksp, stackid);
        }
}

static int
icmp_kstat_update(kstat_t *kp, int rw)
{
        icmp_named_kstat_t *icmpkp;
        netstackid_t    stackid = (zoneid_t)(uintptr_t)kp->ks_private;
        netstack_t      *ns;
        ip_stack_t      *ipst;

        if ((kp == NULL) || (kp->ks_data == NULL))
                return (EIO);

        if (rw == KSTAT_WRITE)
                return (EACCES);

        ns = netstack_find_by_stackid(stackid);
        if (ns == NULL)
                return (-1);
        ipst = ns->netstack_ip;
        if (ipst == NULL) {
                netstack_rele(ns);
                return (-1);
        }
        icmpkp = (icmp_named_kstat_t *)kp->ks_data;

        icmpkp->inMsgs.value.ui32 =         ipst->ips_icmp_mib.icmpInMsgs;
        icmpkp->inErrors.value.ui32 =       ipst->ips_icmp_mib.icmpInErrors;
        icmpkp->inDestUnreachs.value.ui32 =
            ipst->ips_icmp_mib.icmpInDestUnreachs;
        icmpkp->inTimeExcds.value.ui32 =    ipst->ips_icmp_mib.icmpInTimeExcds;
        icmpkp->inParmProbs.value.ui32 =    ipst->ips_icmp_mib.icmpInParmProbs;
        icmpkp->inSrcQuenchs.value.ui32 =   ipst->ips_icmp_mib.icmpInSrcQuenchs;
        icmpkp->inRedirects.value.ui32 =    ipst->ips_icmp_mib.icmpInRedirects;
        icmpkp->inEchos.value.ui32 =        ipst->ips_icmp_mib.icmpInEchos;
        icmpkp->inEchoReps.value.ui32 =     ipst->ips_icmp_mib.icmpInEchoReps;
        icmpkp->inTimestamps.value.ui32 =   ipst->ips_icmp_mib.icmpInTimestamps;
        icmpkp->inTimestampReps.value.ui32 =
            ipst->ips_icmp_mib.icmpInTimestampReps;
        icmpkp->inAddrMasks.value.ui32 =    ipst->ips_icmp_mib.icmpInAddrMasks;
        icmpkp->inAddrMaskReps.value.ui32 =
            ipst->ips_icmp_mib.icmpInAddrMaskReps;
        icmpkp->outMsgs.value.ui32 =        ipst->ips_icmp_mib.icmpOutMsgs;
        icmpkp->outErrors.value.ui32 =      ipst->ips_icmp_mib.icmpOutErrors;
        icmpkp->outDestUnreachs.value.ui32 =
            ipst->ips_icmp_mib.icmpOutDestUnreachs;
        icmpkp->outTimeExcds.value.ui32 =   ipst->ips_icmp_mib.icmpOutTimeExcds;
        icmpkp->outParmProbs.value.ui32 =   ipst->ips_icmp_mib.icmpOutParmProbs;
        icmpkp->outSrcQuenchs.value.ui32 =
            ipst->ips_icmp_mib.icmpOutSrcQuenchs;
        icmpkp->outRedirects.value.ui32 =   ipst->ips_icmp_mib.icmpOutRedirects;
        icmpkp->outEchos.value.ui32 =       ipst->ips_icmp_mib.icmpOutEchos;
        icmpkp->outEchoReps.value.ui32 =    ipst->ips_icmp_mib.icmpOutEchoReps;
        icmpkp->outTimestamps.value.ui32 =
            ipst->ips_icmp_mib.icmpOutTimestamps;
        icmpkp->outTimestampReps.value.ui32 =
            ipst->ips_icmp_mib.icmpOutTimestampReps;
        icmpkp->outAddrMasks.value.ui32 =
            ipst->ips_icmp_mib.icmpOutAddrMasks;
        icmpkp->outAddrMaskReps.value.ui32 =
            ipst->ips_icmp_mib.icmpOutAddrMaskReps;
        icmpkp->inCksumErrs.value.ui32 =    ipst->ips_icmp_mib.icmpInCksumErrs;
        icmpkp->inUnknowns.value.ui32 =     ipst->ips_icmp_mib.icmpInUnknowns;
        icmpkp->inFragNeeded.value.ui32 =   ipst->ips_icmp_mib.icmpInFragNeeded;
        icmpkp->outFragNeeded.value.ui32 =
            ipst->ips_icmp_mib.icmpOutFragNeeded;
        icmpkp->outDrops.value.ui32 =       ipst->ips_icmp_mib.icmpOutDrops;
        icmpkp->inOverflows.value.ui32 =    ipst->ips_icmp_mib.icmpInOverflows;
        icmpkp->inBadRedirects.value.ui32 =
            ipst->ips_icmp_mib.icmpInBadRedirects;

        netstack_rele(ns);
        return (0);
}

/*
 * This is the fanout function for raw socket opened for SCTP.  Note
 * that it is called after SCTP checks that there is no socket which
 * wants a packet.  Then before SCTP handles this out of the blue packet,
 * this function is called to see if there is any raw socket for SCTP.
 * If there is and it is bound to the correct address, the packet will
 * be sent to that socket.  Note that only one raw socket can be bound to
 * a port.  This is assured in ipcl_sctp_hash_insert();
 */
void
ip_fanout_sctp_raw(mblk_t *mp, ipha_t *ipha, ip6_t *ip6h, uint32_t ports,
    ip_recv_attr_t *ira)
{
        conn_t          *connp;
        queue_t         *rq;
        boolean_t       secure;
        ill_t           *ill = ira->ira_ill;
        ip_stack_t      *ipst = ill->ill_ipst;
        ipsec_stack_t   *ipss = ipst->ips_netstack->netstack_ipsec;
        sctp_stack_t    *sctps = ipst->ips_netstack->netstack_sctp;
        iaflags_t       iraflags = ira->ira_flags;
        ill_t           *rill = ira->ira_rill;

        secure = iraflags & IRAF_IPSEC_SECURE;

        connp = ipcl_classify_raw(mp, IPPROTO_SCTP, ports, ipha, ip6h,
            ira, ipst);
        if (connp == NULL) {
                /*
                 * Although raw sctp is not summed, OOB chunks must be.
                 * Drop the packet here if the sctp checksum failed.
                 */
                if (iraflags & IRAF_SCTP_CSUM_ERR) {
                        SCTPS_BUMP_MIB(sctps, sctpChecksumError);
                        freemsg(mp);
                        return;
                }
                ira->ira_ill = ira->ira_rill = NULL;
                sctp_ootb_input(mp, ira, ipst);
                ira->ira_ill = ill;
                ira->ira_rill = rill;
                return;
        }
        rq = connp->conn_rq;
        if (IPCL_IS_NONSTR(connp) ? connp->conn_flow_cntrld : !canputnext(rq)) {
                CONN_DEC_REF(connp);
                BUMP_MIB(ill->ill_ip_mib, rawipIfStatsInOverflows);
                freemsg(mp);
                return;
        }
        if (((iraflags & IRAF_IS_IPV4) ?
            CONN_INBOUND_POLICY_PRESENT(connp, ipss) :
            CONN_INBOUND_POLICY_PRESENT_V6(connp, ipss)) ||
            secure) {
                mp = ipsec_check_inbound_policy(mp, connp, ipha,
                    ip6h, ira);
                if (mp == NULL) {
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsInDiscards);
                        /* Note that mp is NULL */
                        ip_drop_input("ipIfStatsInDiscards", mp, ill);
                        CONN_DEC_REF(connp);
                        return;
                }
        }

        if (iraflags & IRAF_ICMP_ERROR) {
                (connp->conn_recvicmp)(connp, mp, NULL, ira);
        } else {
                ill_t *rill = ira->ira_rill;

                BUMP_MIB(ill->ill_ip_mib, ipIfStatsHCInDelivers);
                /* This is the SOCK_RAW, IPPROTO_SCTP case. */
                ira->ira_ill = ira->ira_rill = NULL;
                (connp->conn_recv)(connp, mp, NULL, ira);
                ira->ira_ill = ill;
                ira->ira_rill = rill;
        }
        CONN_DEC_REF(connp);
}

/*
 * Free a packet that has the link-layer dl_unitdata_req_t or fast-path
 * header before the ip payload.
 */
static void
ip_xmit_flowctl_drop(ill_t *ill, mblk_t *mp, boolean_t is_fp_mp, int fp_mp_len)
{
        int len = (mp->b_wptr - mp->b_rptr);
        mblk_t *ip_mp;

        BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutDiscards);
        if (is_fp_mp || len != fp_mp_len) {
                if (len > fp_mp_len) {
                        /*
                         * fastpath header and ip header in the first mblk
                         */
                        mp->b_rptr += fp_mp_len;
                } else {
                        /*
                         * ip_xmit_attach_llhdr had to prepend an mblk to
                         * attach the fastpath header before ip header.
                         */
                        ip_mp = mp->b_cont;
                        freeb(mp);
                        mp = ip_mp;
                        mp->b_rptr += (fp_mp_len - len);
                }
        } else {
                ip_mp = mp->b_cont;
                freeb(mp);
                mp = ip_mp;
        }
        ip_drop_output("ipIfStatsOutDiscards - flow ctl", mp, ill);
        freemsg(mp);
}

/*
 * Normal post fragmentation function.
 *
 * Send a packet using the passed in nce. This handles both IPv4 and IPv6
 * using the same state machine.
 *
 * We return an error on failure. In particular we return EWOULDBLOCK
 * when the driver flow controls. In that case this ensures that ip_wsrv runs
 * (currently by canputnext failure resulting in backenabling from GLD.)
 * This allows the callers of conn_ip_output() to use EWOULDBLOCK as an
 * indication that they can flow control until ip_wsrv() tells then to restart.
 *
 * If the nce passed by caller is incomplete, this function
 * queues the packet and if necessary, sends ARP request and bails.
 * If the Neighbor Cache passed is fully resolved, we simply prepend
 * the link-layer header to the packet, do ipsec hw acceleration
 * work if necessary, and send the packet out on the wire.
 */
/* ARGSUSED6 */
int
ip_xmit(mblk_t *mp, nce_t *nce, iaflags_t ixaflags, uint_t pkt_len,
    uint32_t xmit_hint, zoneid_t szone, zoneid_t nolzid, uintptr_t *ixacookie)
{
        queue_t         *wq;
        ill_t           *ill = nce->nce_ill;
        ip_stack_t      *ipst = ill->ill_ipst;
        uint64_t        delta;
        boolean_t       isv6 = ill->ill_isv6;
        boolean_t       fp_mp;
        ncec_t          *ncec = nce->nce_common;
        int64_t         now = LBOLT_FASTPATH64;
        boolean_t       is_probe;

        DTRACE_PROBE1(ip__xmit, nce_t *, nce);

        ASSERT(mp != NULL);
        ASSERT(mp->b_datap->db_type == M_DATA);
        ASSERT(pkt_len == msgdsize(mp));

        /*
         * If we have already been here and are coming back after ARP/ND.
         * the IXAF_NO_TRACE flag is set. We skip FW_HOOKS, DTRACE and ipobs
         * in that case since they have seen the packet when it came here
         * the first time.
         */
        if (ixaflags & IXAF_NO_TRACE)
                goto sendit;

        if (ixaflags & IXAF_IS_IPV4) {
                ipha_t *ipha = (ipha_t *)mp->b_rptr;

                ASSERT(!isv6);
                ASSERT(pkt_len == ntohs(((ipha_t *)mp->b_rptr)->ipha_length));
                if (HOOKS4_INTERESTED_PHYSICAL_OUT(ipst) &&
                    !(ixaflags & IXAF_NO_PFHOOK)) {
                        int     error;

                        FW_HOOKS(ipst->ips_ip4_physical_out_event,
                            ipst->ips_ipv4firewall_physical_out,
                            NULL, ill, ipha, mp, mp, 0, ipst, error);
                        DTRACE_PROBE1(ip4__physical__out__end,
                            mblk_t *, mp);
                        if (mp == NULL)
                                return (error);

                        /* The length could have changed */
                        pkt_len = msgdsize(mp);
                }
                if (ipst->ips_ip4_observe.he_interested) {
                        /*
                         * Note that for TX the zoneid is the sending
                         * zone, whether or not MLP is in play.
                         * Since the szone argument is the IP zoneid (i.e.,
                         * zero for exclusive-IP zones) and ipobs wants
                         * the system zoneid, we map it here.
                         */
                        szone = IP_REAL_ZONEID(szone, ipst);

                        /*
                         * On the outbound path the destination zone will be
                         * unknown as we're sending this packet out on the
                         * wire.
                         */
                        ipobs_hook(mp, IPOBS_HOOK_OUTBOUND, szone, ALL_ZONES,
                            ill, ipst);
                }
                DTRACE_IP7(send, mblk_t *, mp,  conn_t *, NULL,
                    void_ip_t *, ipha,  __dtrace_ipsr_ill_t *, ill,
                    ipha_t *, ipha, ip6_t *, NULL, int, 0);
        } else {
                ip6_t *ip6h = (ip6_t *)mp->b_rptr;

                ASSERT(isv6);
                ASSERT(pkt_len ==
                    ntohs(((ip6_t *)mp->b_rptr)->ip6_plen) + IPV6_HDR_LEN);
                if (HOOKS6_INTERESTED_PHYSICAL_OUT(ipst) &&
                    !(ixaflags & IXAF_NO_PFHOOK)) {
                        int     error;

                        FW_HOOKS6(ipst->ips_ip6_physical_out_event,
                            ipst->ips_ipv6firewall_physical_out,
                            NULL, ill, ip6h, mp, mp, 0, ipst, error);
                        DTRACE_PROBE1(ip6__physical__out__end,
                            mblk_t *, mp);
                        if (mp == NULL)
                                return (error);

                        /* The length could have changed */
                        pkt_len = msgdsize(mp);
                }
                if (ipst->ips_ip6_observe.he_interested) {
                        /* See above */
                        szone = IP_REAL_ZONEID(szone, ipst);

                        ipobs_hook(mp, IPOBS_HOOK_OUTBOUND, szone, ALL_ZONES,
                            ill, ipst);
                }
                DTRACE_IP7(send, mblk_t *, mp,  conn_t *, NULL,
                    void_ip_t *, ip6h,  __dtrace_ipsr_ill_t *, ill,
                    ipha_t *, NULL, ip6_t *, ip6h, int, 0);
        }

sendit:
        /*
         * We check the state without a lock because the state can never
         * move "backwards" to initial or incomplete.
         */
        switch (ncec->ncec_state) {
        case ND_REACHABLE:
        case ND_STALE:
        case ND_DELAY:
        case ND_PROBE:
                mp = ip_xmit_attach_llhdr(mp, nce);
                if (mp == NULL) {
                        /*
                         * ip_xmit_attach_llhdr has increased
                         * ipIfStatsOutDiscards and called ip_drop_output()
                         */
                        return (ENOBUFS);
                }
                /*
                 * check if nce_fastpath completed and we tagged on a
                 * copy of nce_fp_mp in ip_xmit_attach_llhdr().
                 */
                fp_mp = (mp->b_datap->db_type == M_DATA);

                if (fp_mp &&
                    (ill->ill_capabilities & ILL_CAPAB_DLD_DIRECT)) {
                        ill_dld_direct_t *idd;

                        idd = &ill->ill_dld_capab->idc_direct;
                        /*
                         * Send the packet directly to DLD, where it
                         * may be queued depending on the availability
                         * of transmit resources at the media layer.
                         * Return value should be taken into
                         * account and flow control the TCP.
                         */
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsHCOutTransmits);
                        UPDATE_MIB(ill->ill_ip_mib, ipIfStatsHCOutOctets,
                            pkt_len);

                        if (ixaflags & IXAF_NO_DEV_FLOW_CTL) {
                                (void) idd->idd_tx_df(idd->idd_tx_dh, mp,
                                    (uintptr_t)xmit_hint, IP_DROP_ON_NO_DESC);
                        } else {
                                uintptr_t cookie;

                                if ((cookie = idd->idd_tx_df(idd->idd_tx_dh,
                                    mp, (uintptr_t)xmit_hint, 0)) != 0) {
                                        if (ixacookie != NULL)
                                                *ixacookie = cookie;
                                        return (EWOULDBLOCK);
                                }
                        }
                } else {
                        wq = ill->ill_wq;

                        if (!(ixaflags & IXAF_NO_DEV_FLOW_CTL) &&
                            !canputnext(wq)) {
                                if (ixacookie != NULL)
                                        *ixacookie = 0;
                                ip_xmit_flowctl_drop(ill, mp, fp_mp,
                                    nce->nce_fp_mp != NULL ?
                                    MBLKL(nce->nce_fp_mp) : 0);
                                return (EWOULDBLOCK);
                        }
                        BUMP_MIB(ill->ill_ip_mib, ipIfStatsHCOutTransmits);
                        UPDATE_MIB(ill->ill_ip_mib, ipIfStatsHCOutOctets,
                            pkt_len);
                        putnext(wq, mp);
                }

                /*
                 * The rest of this function implements Neighbor Unreachability
                 * detection. Determine if the ncec is eligible for NUD.
                 */
                if (ncec->ncec_flags & NCE_F_NONUD)
                        return (0);

                ASSERT(ncec->ncec_state != ND_INCOMPLETE);

                /*
                 * Check for upper layer advice
                 */
                if (ixaflags & IXAF_REACH_CONF) {
                        timeout_id_t tid;

                        /*
                         * It should be o.k. to check the state without
                         * a lock here, at most we lose an advice.
                         */
                        ncec->ncec_last = TICK_TO_MSEC(now);
                        if (ncec->ncec_state != ND_REACHABLE) {
                                mutex_enter(&ncec->ncec_lock);
                                ncec->ncec_state = ND_REACHABLE;
                                tid = ncec->ncec_timeout_id;
                                ncec->ncec_timeout_id = 0;
                                mutex_exit(&ncec->ncec_lock);
                                (void) untimeout(tid);
                                if (ip_debug > 2) {
                                        /* ip1dbg */
                                        pr_addr_dbg("ip_xmit: state"
                                            " for %s changed to"
                                            " REACHABLE\n", AF_INET6,
                                            &ncec->ncec_addr);
                                }
                        }
                        return (0);
                }

                delta =  TICK_TO_MSEC(now) - ncec->ncec_last;
                ip1dbg(("ip_xmit: delta = %" PRId64
                    " ill_reachable_time = %d \n", delta,
                    ill->ill_reachable_time));
                if (delta > (uint64_t)ill->ill_reachable_time) {
                        mutex_enter(&ncec->ncec_lock);
                        switch (ncec->ncec_state) {
                        case ND_REACHABLE:
                                ASSERT((ncec->ncec_flags & NCE_F_NONUD) == 0);
                                /* FALLTHROUGH */
                        case ND_STALE:
                                /*
                                 * ND_REACHABLE is identical to
                                 * ND_STALE in this specific case. If
                                 * reachable time has expired for this
                                 * neighbor (delta is greater than
                                 * reachable time), conceptually, the
                                 * neighbor cache is no longer in
                                 * REACHABLE state, but already in
                                 * STALE state.  So the correct
                                 * transition here is to ND_DELAY.
                                 */
                                ncec->ncec_state = ND_DELAY;
                                mutex_exit(&ncec->ncec_lock);
                                nce_restart_timer(ncec,
                                    ipst->ips_delay_first_probe_time);
                                if (ip_debug > 3) {
                                        /* ip2dbg */
                                        pr_addr_dbg("ip_xmit: state"
                                            " for %s changed to"
                                            " DELAY\n", AF_INET6,
                                            &ncec->ncec_addr);
                                }
                                break;
                        case ND_DELAY:
                        case ND_PROBE:
                                mutex_exit(&ncec->ncec_lock);
                                /* Timers have already started */
                                break;
                        case ND_UNREACHABLE:
                                /*
                                 * nce_timer has detected that this ncec
                                 * is unreachable and initiated deleting
                                 * this ncec.
                                 * This is a harmless race where we found the
                                 * ncec before it was deleted and have
                                 * just sent out a packet using this
                                 * unreachable ncec.
                                 */
                                mutex_exit(&ncec->ncec_lock);
                                break;
                        default:
                                ASSERT(0);
                                mutex_exit(&ncec->ncec_lock);
                        }
                }
                return (0);

        case ND_INCOMPLETE:
                /*
                 * the state could have changed since we didn't hold the lock.
                 * Re-verify state under lock.
                 */
                is_probe = ipmp_packet_is_probe(mp, nce->nce_ill);
                mutex_enter(&ncec->ncec_lock);
                if (NCE_ISREACHABLE(ncec)) {
                        mutex_exit(&ncec->ncec_lock);
                        goto sendit;
                }
                /* queue the packet */
                nce_queue_mp(ncec, mp, is_probe);
                mutex_exit(&ncec->ncec_lock);
                DTRACE_PROBE2(ip__xmit__incomplete,
                    (ncec_t *), ncec, (mblk_t *), mp);
                return (0);

        case ND_INITIAL:
                /*
                 * State could have changed since we didn't hold the lock, so
                 * re-verify state.
                 */
                is_probe = ipmp_packet_is_probe(mp, nce->nce_ill);
                mutex_enter(&ncec->ncec_lock);
                if (NCE_ISREACHABLE(ncec))  {
                        mutex_exit(&ncec->ncec_lock);
                        goto sendit;
                }
                nce_queue_mp(ncec, mp, is_probe);
                if (ncec->ncec_state == ND_INITIAL) {
                        ncec->ncec_state = ND_INCOMPLETE;
                        mutex_exit(&ncec->ncec_lock);
                        /*
                         * figure out the source we want to use
                         * and resolve it.
                         */
                        ip_ndp_resolve(ncec);
                } else  {
                        mutex_exit(&ncec->ncec_lock);
                }
                return (0);

        case ND_UNREACHABLE:
                BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutDiscards);
                ip_drop_output("ipIfStatsOutDiscards - ND_UNREACHABLE",
                    mp, ill);
                freemsg(mp);
                return (0);

        default:
                ASSERT(0);
                BUMP_MIB(ill->ill_ip_mib, ipIfStatsOutDiscards);
                ip_drop_output("ipIfStatsOutDiscards - ND_other",
                    mp, ill);
                freemsg(mp);
                return (ENETUNREACH);
        }
}

/*
 * Return B_TRUE if the buffers differ in length or content.
 * This is used for comparing extension header buffers.
 * Note that an extension header would be declared different
 * even if all that changed was the next header value in that header i.e.
 * what really changed is the next extension header.
 */
boolean_t
ip_cmpbuf(const void *abuf, uint_t alen, boolean_t b_valid, const void *bbuf,
    uint_t blen)
{
        if (!b_valid)
                blen = 0;

        if (alen != blen)
                return (B_TRUE);
        if (alen == 0)
                return (B_FALSE);       /* Both zero length */
        return (bcmp(abuf, bbuf, alen));
}

/*
 * Preallocate memory for ip_savebuf(). Returns B_TRUE if ok.
 * Return B_FALSE if memory allocation fails - don't change any state!
 */
boolean_t
ip_allocbuf(void **dstp, uint_t *dstlenp, boolean_t src_valid,
    const void *src, uint_t srclen)
{
        void *dst;

        if (!src_valid)
                srclen = 0;

        ASSERT(*dstlenp == 0);
        if (src != NULL && srclen != 0) {
                dst = mi_alloc(srclen, BPRI_MED);
                if (dst == NULL)
                        return (B_FALSE);
        } else {
                dst = NULL;
        }
        if (*dstp != NULL)
                mi_free(*dstp);
        *dstp = dst;
        *dstlenp = dst == NULL ? 0 : srclen;
        return (B_TRUE);
}

/*
 * Replace what is in *dst, *dstlen with the source.
 * Assumes ip_allocbuf has already been called.
 */
void
ip_savebuf(void **dstp, uint_t *dstlenp, boolean_t src_valid,
    const void *src, uint_t srclen)
{
        if (!src_valid)
                srclen = 0;

        ASSERT(*dstlenp == srclen);
        if (src != NULL && srclen != 0)
                bcopy(src, *dstp, srclen);
}

/*
 * Free the storage pointed to by the members of an ip_pkt_t.
 */
void
ip_pkt_free(ip_pkt_t *ipp)
{
        uint_t  fields = ipp->ipp_fields;

        if (fields & IPPF_HOPOPTS) {
                kmem_free(ipp->ipp_hopopts, ipp->ipp_hopoptslen);
                ipp->ipp_hopopts = NULL;
                ipp->ipp_hopoptslen = 0;
        }
        if (fields & IPPF_RTHDRDSTOPTS) {
                kmem_free(ipp->ipp_rthdrdstopts, ipp->ipp_rthdrdstoptslen);
                ipp->ipp_rthdrdstopts = NULL;
                ipp->ipp_rthdrdstoptslen = 0;
        }
        if (fields & IPPF_DSTOPTS) {
                kmem_free(ipp->ipp_dstopts, ipp->ipp_dstoptslen);
                ipp->ipp_dstopts = NULL;
                ipp->ipp_dstoptslen = 0;
        }
        if (fields & IPPF_RTHDR) {
                kmem_free(ipp->ipp_rthdr, ipp->ipp_rthdrlen);
                ipp->ipp_rthdr = NULL;
                ipp->ipp_rthdrlen = 0;
        }
        if (fields & IPPF_IPV4_OPTIONS) {
                kmem_free(ipp->ipp_ipv4_options, ipp->ipp_ipv4_options_len);
                ipp->ipp_ipv4_options = NULL;
                ipp->ipp_ipv4_options_len = 0;
        }
        ipp->ipp_fields &= ~(IPPF_HOPOPTS | IPPF_RTHDRDSTOPTS | IPPF_DSTOPTS |
            IPPF_RTHDR | IPPF_IPV4_OPTIONS);
}

/*
 * Copy from src to dst and allocate as needed.
 * Returns zero or ENOMEM.
 *
 * The caller must initialize dst to zero.
 */
int
ip_pkt_copy(ip_pkt_t *src, ip_pkt_t *dst, int kmflag)
{
        uint_t  fields = src->ipp_fields;

        /* Start with fields that don't require memory allocation */
        dst->ipp_fields = fields &
            ~(IPPF_HOPOPTS | IPPF_RTHDRDSTOPTS | IPPF_DSTOPTS |
            IPPF_RTHDR | IPPF_IPV4_OPTIONS);

        dst->ipp_addr = src->ipp_addr;
        dst->ipp_unicast_hops = src->ipp_unicast_hops;
        dst->ipp_hoplimit = src->ipp_hoplimit;
        dst->ipp_tclass = src->ipp_tclass;
        dst->ipp_type_of_service = src->ipp_type_of_service;

        if (!(fields & (IPPF_HOPOPTS | IPPF_RTHDRDSTOPTS | IPPF_DSTOPTS |
            IPPF_RTHDR | IPPF_IPV4_OPTIONS)))
                return (0);

        if (fields & IPPF_HOPOPTS) {
                dst->ipp_hopopts = kmem_alloc(src->ipp_hopoptslen, kmflag);
                if (dst->ipp_hopopts == NULL) {
                        ip_pkt_free(dst);
                        return (ENOMEM);
                }
                dst->ipp_fields |= IPPF_HOPOPTS;
                bcopy(src->ipp_hopopts, dst->ipp_hopopts,
                    src->ipp_hopoptslen);
                dst->ipp_hopoptslen = src->ipp_hopoptslen;
        }
        if (fields & IPPF_RTHDRDSTOPTS) {
                dst->ipp_rthdrdstopts = kmem_alloc(src->ipp_rthdrdstoptslen,
                    kmflag);
                if (dst->ipp_rthdrdstopts == NULL) {
                        ip_pkt_free(dst);
                        return (ENOMEM);
                }
                dst->ipp_fields |= IPPF_RTHDRDSTOPTS;
                bcopy(src->ipp_rthdrdstopts, dst->ipp_rthdrdstopts,
                    src->ipp_rthdrdstoptslen);
                dst->ipp_rthdrdstoptslen = src->ipp_rthdrdstoptslen;
        }
        if (fields & IPPF_DSTOPTS) {
                dst->ipp_dstopts = kmem_alloc(src->ipp_dstoptslen, kmflag);
                if (dst->ipp_dstopts == NULL) {
                        ip_pkt_free(dst);
                        return (ENOMEM);
                }
                dst->ipp_fields |= IPPF_DSTOPTS;
                bcopy(src->ipp_dstopts, dst->ipp_dstopts,
                    src->ipp_dstoptslen);
                dst->ipp_dstoptslen = src->ipp_dstoptslen;
        }
        if (fields & IPPF_RTHDR) {
                dst->ipp_rthdr = kmem_alloc(src->ipp_rthdrlen, kmflag);
                if (dst->ipp_rthdr == NULL) {
                        ip_pkt_free(dst);
                        return (ENOMEM);
                }
                dst->ipp_fields |= IPPF_RTHDR;
                bcopy(src->ipp_rthdr, dst->ipp_rthdr,
                    src->ipp_rthdrlen);
                dst->ipp_rthdrlen = src->ipp_rthdrlen;
        }
        if (fields & IPPF_IPV4_OPTIONS) {
                dst->ipp_ipv4_options = kmem_alloc(src->ipp_ipv4_options_len,
                    kmflag);
                if (dst->ipp_ipv4_options == NULL) {
                        ip_pkt_free(dst);
                        return (ENOMEM);
                }
                dst->ipp_fields |= IPPF_IPV4_OPTIONS;
                bcopy(src->ipp_ipv4_options, dst->ipp_ipv4_options,
                    src->ipp_ipv4_options_len);
                dst->ipp_ipv4_options_len = src->ipp_ipv4_options_len;
        }
        if (fields & IPPF_FRAGHDR) {
                dst->ipp_fraghdr = kmem_alloc(src->ipp_fraghdrlen, kmflag);
                if (dst->ipp_fraghdr == NULL) {
                        ip_pkt_free(dst);
                        return (ENOMEM);
                }
                dst->ipp_fields |= IPPF_FRAGHDR;
                bcopy(src->ipp_fraghdr, dst->ipp_fraghdr,
                    src->ipp_fraghdrlen);
                dst->ipp_fraghdrlen = src->ipp_fraghdrlen;
        }
        return (0);
}

/*
 * Returns INADDR_ANY if no source route
 */
ipaddr_t
ip_pkt_source_route_v4(const ip_pkt_t *ipp)
{
        ipaddr_t        nexthop = INADDR_ANY;
        ipoptp_t        opts;
        uchar_t         *opt;
        uint8_t         optval;
        uint8_t         optlen;
        uint32_t        totallen;

        if (!(ipp->ipp_fields & IPPF_IPV4_OPTIONS))
                return (INADDR_ANY);

        totallen = ipp->ipp_ipv4_options_len;
        if (totallen & 0x3)
                return (INADDR_ANY);

        for (optval = ipoptp_first2(&opts, totallen, ipp->ipp_ipv4_options);
            optval != IPOPT_EOL;
            optval = ipoptp_next(&opts)) {
                opt = opts.ipoptp_cur;
                switch (optval) {
                        uint8_t off;
                case IPOPT_SSRR:
                case IPOPT_LSRR:
                        if ((opts.ipoptp_flags & IPOPTP_ERROR) != 0) {
                                break;
                        }
                        optlen = opts.ipoptp_len;
                        off = opt[IPOPT_OFFSET];
                        off--;
                        if (optlen < IP_ADDR_LEN ||
                            off > optlen - IP_ADDR_LEN) {
                                /* End of source route */
                                break;
                        }
                        bcopy((char *)opt + off, &nexthop, IP_ADDR_LEN);
                        if (nexthop == htonl(INADDR_LOOPBACK)) {
                                /* Ignore */
                                nexthop = INADDR_ANY;
                                break;
                        }
                        break;
                }
        }
        return (nexthop);
}

/*
 * Reverse a source route.
 */
void
ip_pkt_source_route_reverse_v4(ip_pkt_t *ipp)
{
        ipaddr_t        tmp;
        ipoptp_t        opts;
        uchar_t         *opt;
        uint8_t         optval;
        uint32_t        totallen;

        if (!(ipp->ipp_fields & IPPF_IPV4_OPTIONS))
                return;

        totallen = ipp->ipp_ipv4_options_len;
        if (totallen & 0x3)
                return;

        for (optval = ipoptp_first2(&opts, totallen, ipp->ipp_ipv4_options);
            optval != IPOPT_EOL;
            optval = ipoptp_next(&opts)) {
                uint8_t off1, off2;

                opt = opts.ipoptp_cur;
                switch (optval) {
                case IPOPT_SSRR:
                case IPOPT_LSRR:
                        if ((opts.ipoptp_flags & IPOPTP_ERROR) != 0) {
                                break;
                        }
                        off1 = IPOPT_MINOFF_SR - 1;
                        off2 = opt[IPOPT_OFFSET] - IP_ADDR_LEN - 1;
                        while (off2 > off1) {
                                bcopy(opt + off2, &tmp, IP_ADDR_LEN);
                                bcopy(opt + off1, opt + off2, IP_ADDR_LEN);
                                bcopy(&tmp, opt + off2, IP_ADDR_LEN);
                                off2 -= IP_ADDR_LEN;
                                off1 += IP_ADDR_LEN;
                        }
                        opt[IPOPT_OFFSET] = IPOPT_MINOFF_SR;
                        break;
                }
        }
}

/*
 * Returns NULL if no routing header
 */
in6_addr_t *
ip_pkt_source_route_v6(const ip_pkt_t *ipp)
{
        in6_addr_t      *nexthop = NULL;
        ip6_rthdr0_t    *rthdr;

        if (!(ipp->ipp_fields & IPPF_RTHDR))
                return (NULL);

        rthdr = (ip6_rthdr0_t *)ipp->ipp_rthdr;
        if (rthdr->ip6r0_segleft == 0)
                return (NULL);

        nexthop = (in6_addr_t *)((char *)rthdr + sizeof (*rthdr));
        return (nexthop);
}

zoneid_t
ip_get_zoneid_v4(ipaddr_t addr, mblk_t *mp, ip_recv_attr_t *ira,
    zoneid_t lookup_zoneid)
{
        ip_stack_t      *ipst = ira->ira_ill->ill_ipst;
        ire_t           *ire;
        int             ire_flags = MATCH_IRE_TYPE;
        zoneid_t        zoneid = ALL_ZONES;

        if (lookup_zoneid != ALL_ZONES)
                ire_flags |= MATCH_IRE_ZONEONLY;
        ire = ire_ftable_lookup_v4(addr, 0, 0, IRE_LOCAL | IRE_LOOPBACK,
            NULL, lookup_zoneid, ire_flags, 0, ipst, NULL);
        if (ire != NULL) {
                zoneid = IP_REAL_ZONEID(ire->ire_zoneid, ipst);
                ire_refrele(ire);
        }
        return (zoneid);
}

zoneid_t
ip_get_zoneid_v6(in6_addr_t *addr, mblk_t *mp, const ill_t *ill,
    ip_recv_attr_t *ira, zoneid_t lookup_zoneid)
{
        ip_stack_t      *ipst = ira->ira_ill->ill_ipst;
        ire_t           *ire;
        int             ire_flags = MATCH_IRE_TYPE;
        zoneid_t        zoneid = ALL_ZONES;

        if (IN6_IS_ADDR_LINKLOCAL(addr))
                ire_flags |= MATCH_IRE_ILL;

        if (lookup_zoneid != ALL_ZONES)
                ire_flags |= MATCH_IRE_ZONEONLY;
        ire = ire_ftable_lookup_v6(addr, NULL, NULL, IRE_LOCAL | IRE_LOOPBACK,
            ill, lookup_zoneid, ire_flags, 0, ipst, NULL);
        if (ire != NULL) {
                zoneid = IP_REAL_ZONEID(ire->ire_zoneid, ipst);
                ire_refrele(ire);
        }
        return (zoneid);
}

/*
 * IP obserability hook support functions.
 */
static void
ipobs_init(ip_stack_t *ipst)
{
        netid_t id;

        id = net_getnetidbynetstackid(ipst->ips_netstack->netstack_stackid);

        ipst->ips_ip4_observe_pr = net_protocol_lookup(id, NHF_INET);
        VERIFY(ipst->ips_ip4_observe_pr != NULL);

        ipst->ips_ip6_observe_pr = net_protocol_lookup(id, NHF_INET6);
        VERIFY(ipst->ips_ip6_observe_pr != NULL);
}

static void
ipobs_fini(ip_stack_t *ipst)
{

        VERIFY(net_protocol_release(ipst->ips_ip4_observe_pr) == 0);
        VERIFY(net_protocol_release(ipst->ips_ip6_observe_pr) == 0);
}

/*
 * hook_pkt_observe_t is composed in network byte order so that the
 * entire mblk_t chain handed into hook_run can be used as-is.
 * The caveat is that use of the fields, such as the zone fields,
 * requires conversion into host byte order first.
 */
void
ipobs_hook(mblk_t *mp, int htype, zoneid_t zsrc, zoneid_t zdst,
    const ill_t *ill, ip_stack_t *ipst)
{
        hook_pkt_observe_t *hdr;
        uint64_t grifindex;
        mblk_t *imp;

        imp = allocb(sizeof (*hdr), BPRI_HI);
        if (imp == NULL)
                return;

        hdr = (hook_pkt_observe_t *)imp->b_rptr;
        /*
         * b_wptr is set to make the apparent size of the data in the mblk_t
         * to exclude the pointers at the end of hook_pkt_observer_t.
         */
        imp->b_wptr = imp->b_rptr + sizeof (dl_ipnetinfo_t);
        imp->b_cont = mp;

        ASSERT(DB_TYPE(mp) == M_DATA);

        if (IS_UNDER_IPMP(ill))
                grifindex = ipmp_ill_get_ipmp_ifindex(ill);
        else
                grifindex = 0;

        hdr->hpo_version = 1;
        hdr->hpo_htype = htons(htype);
        hdr->hpo_pktlen = htonl((ulong_t)msgdsize(mp));
        hdr->hpo_ifindex = htonl(ill->ill_phyint->phyint_ifindex);
        hdr->hpo_grifindex = htonl(grifindex);
        hdr->hpo_zsrc = htonl(zsrc);
        hdr->hpo_zdst = htonl(zdst);
        hdr->hpo_pkt = imp;
        hdr->hpo_ctx = ipst->ips_netstack;

        if (ill->ill_isv6) {
                hdr->hpo_family = AF_INET6;
                (void) hook_run(ipst->ips_ipv6_net_data->netd_hooks,
                    ipst->ips_ipv6observing, (hook_data_t)hdr);
        } else {
                hdr->hpo_family = AF_INET;
                (void) hook_run(ipst->ips_ipv4_net_data->netd_hooks,
                    ipst->ips_ipv4observing, (hook_data_t)hdr);
        }

        imp->b_cont = NULL;
        freemsg(imp);
}

/*
 * Utility routine that checks if `v4srcp' is a valid address on underlying
 * interface `ill'.  If `ipifp' is non-NULL, it's set to a held ipif
 * associated with `v4srcp' on success.  NOTE: if this is not called from
 * inside the IPSQ (ill_g_lock is not held), `ill' may be removed from the
 * group during or after this lookup.
 */
boolean_t
ipif_lookup_testaddr_v4(ill_t *ill, const in_addr_t *v4srcp, ipif_t **ipifp)
{
        ipif_t *ipif;

        ipif = ipif_lookup_addr_exact(*v4srcp, ill, ill->ill_ipst);
        if (ipif != NULL) {
                if (ipifp != NULL)
                        *ipifp = ipif;
                else
                        ipif_refrele(ipif);
                return (B_TRUE);
        }

        ip1dbg(("ipif_lookup_testaddr_v4: cannot find ipif for src %x\n",
            *v4srcp));
        return (B_FALSE);
}

/*
 * Transport protocol call back function for CPU state change.
 */
/* ARGSUSED */
static int
ip_tp_cpu_update(cpu_setup_t what, int id, void *arg)
{
        processorid_t cpu_seqid;
        netstack_handle_t nh;
        netstack_t *ns;

        ASSERT(MUTEX_HELD(&cpu_lock));

        switch (what) {
        case CPU_CONFIG:
        case CPU_ON:
        case CPU_INIT:
        case CPU_CPUPART_IN:
                cpu_seqid = cpu[id]->cpu_seqid;
                netstack_next_init(&nh);
                while ((ns = netstack_next(&nh)) != NULL) {
                        tcp_stack_cpu_add(ns->netstack_tcp, cpu_seqid);
                        sctp_stack_cpu_add(ns->netstack_sctp, cpu_seqid);
                        udp_stack_cpu_add(ns->netstack_udp, cpu_seqid);
                        netstack_rele(ns);
                }
                netstack_next_fini(&nh);
                break;
        case CPU_UNCONFIG:
        case CPU_OFF:
        case CPU_CPUPART_OUT:
                /*
                 * Nothing to do.  We don't remove the per CPU stats from
                 * the IP stack even when the CPU goes offline.
                 */
                break;
        default:
                break;
        }
        return (0);
}