16666 loader: reading from large dosfs fails

[illumos-gate.git] / usr / src / uts / common / inet / ip / icmp.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) 2013 by Delphix. All rights reserved.
 * Copyright 2014, OmniTI Computer Consulting, Inc. All rights reserved.
 * Copyright (c) 2018, Joyent, Inc.
 * Copyright 2024 Oxide Computer Company
 */
/* Copyright (c) 1990 Mentat Inc. */

#include <sys/types.h>
#include <sys/stream.h>
#include <sys/stropts.h>
#include <sys/strlog.h>
#include <sys/strsun.h>
#define _SUN_TPI_VERSION 2
#include <sys/tihdr.h>
#include <sys/timod.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/strsubr.h>
#include <sys/suntpi.h>
#include <sys/xti_inet.h>
#include <sys/cmn_err.h>
#include <sys/kmem.h>
#include <sys/cred.h>
#include <sys/policy.h>
#include <sys/priv.h>
#include <sys/ucred.h>
#include <sys/zone.h>

#include <sys/sockio.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/vtrace.h>
#include <sys/sdt.h>
#include <sys/debug.h>
#include <sys/isa_defs.h>
#include <sys/random.h>
#include <netinet/in.h>
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#include <netinet/udp.h>

#include <inet/common.h>
#include <inet/ip.h>
#include <inet/ip_impl.h>
#include <inet/ipsec_impl.h>
#include <inet/ip6.h>
#include <inet/ip_ire.h>
#include <inet/ip_if.h>
#include <inet/ip_multi.h>
#include <inet/ip_ndp.h>
#include <inet/proto_set.h>
#include <inet/mib2.h>
#include <inet/nd.h>
#include <inet/optcom.h>
#include <inet/snmpcom.h>
#include <inet/kstatcom.h>
#include <inet/ipclassifier.h>

#include <sys/tsol/label.h>
#include <sys/tsol/tnet.h>

#include <inet/rawip_impl.h>

#include <sys/disp.h>

/*
 * Synchronization notes:
 *
 * RAWIP is MT and uses the usual kernel synchronization primitives. We use
 * conn_lock to protect the icmp_t.
 *
 * Plumbing notes:
 * ICMP is always a device driver. For compatibility with mibopen() code
 * it is possible to I_PUSH "icmp", but that results in pushing a passthrough
 * dummy module.
 */
static void     icmp_addr_req(queue_t *q, mblk_t *mp);
static void     icmp_tpi_bind(queue_t *q, mblk_t *mp);
static void     icmp_bind_proto(icmp_t *icmp);
static int      icmp_build_hdr_template(conn_t *, const in6_addr_t *,
    const in6_addr_t *, uint32_t);
static void     icmp_capability_req(queue_t *q, mblk_t *mp);
static int      icmp_close(queue_t *q, int flags, cred_t *);
static void     icmp_close_free(conn_t *);
static void     icmp_tpi_connect(queue_t *q, mblk_t *mp);
static void     icmp_tpi_disconnect(queue_t *q, mblk_t *mp);
static void     icmp_err_ack(queue_t *q, mblk_t *mp, t_scalar_t t_error,
    int sys_error);
static void     icmp_err_ack_prim(queue_t *q, mblk_t *mp, t_scalar_t primitive,
    t_scalar_t tlierr, int sys_error);
static void     icmp_icmp_input(void *arg1, mblk_t *mp, void *arg2,
    ip_recv_attr_t *);
static void     icmp_icmp_error_ipv6(conn_t *connp, mblk_t *mp,
    ip_recv_attr_t *);
static void     icmp_info_req(queue_t *q, mblk_t *mp);
static void     icmp_input(void *, mblk_t *, void *, ip_recv_attr_t *);
static conn_t   *icmp_open(int family, cred_t *credp, int *err, int flags);
static int      icmp_openv4(queue_t *q, dev_t *devp, int flag, int sflag,
                    cred_t *credp);
static int      icmp_openv6(queue_t *q, dev_t *devp, int flag, int sflag,
                    cred_t *credp);
static boolean_t icmp_opt_allow_udr_set(t_scalar_t level, t_scalar_t name);
int             icmp_opt_set(conn_t *connp, uint_t optset_context,
                    int level, int name, uint_t inlen,
                    uchar_t *invalp, uint_t *outlenp, uchar_t *outvalp,
                    void *thisdg_attrs, cred_t *cr);
int             icmp_opt_get(conn_t *connp, int level, int name,
                    uchar_t *ptr);
static int      icmp_output_newdst(conn_t *connp, mblk_t *data_mp, sin_t *sin,
                    sin6_t *sin6, cred_t *cr, pid_t pid, ip_xmit_attr_t *ixa);
static mblk_t   *icmp_prepend_hdr(conn_t *, ip_xmit_attr_t *, const ip_pkt_t *,
    const in6_addr_t *, const in6_addr_t *, uint32_t, mblk_t *, int *);
static mblk_t   *icmp_prepend_header_template(conn_t *, ip_xmit_attr_t *,
    mblk_t *, const in6_addr_t *, uint32_t, int *);
static int      icmp_snmp_set(queue_t *q, t_scalar_t level, t_scalar_t name,
                    uchar_t *ptr, int len);
static void     icmp_ud_err(queue_t *q, mblk_t *mp, t_scalar_t err);
static void     icmp_tpi_unbind(queue_t *q, mblk_t *mp);
static int      icmp_wput(queue_t *q, mblk_t *mp);
static int      icmp_wput_fallback(queue_t *q, mblk_t *mp);
static void     icmp_wput_other(queue_t *q, mblk_t *mp);
static void     icmp_wput_iocdata(queue_t *q, mblk_t *mp);
static void     icmp_wput_restricted(queue_t *q, mblk_t *mp);
static void     icmp_ulp_recv(conn_t *, mblk_t *, uint_t);

static void     *rawip_stack_init(netstackid_t stackid, netstack_t *ns);
static void     rawip_stack_fini(netstackid_t stackid, void *arg);

static void     *rawip_kstat_init(netstackid_t stackid);
static void     rawip_kstat_fini(netstackid_t stackid, kstat_t *ksp);
static int      rawip_kstat_update(kstat_t *kp, int rw);
static void     rawip_stack_shutdown(netstackid_t stackid, void *arg);

/* Common routines for TPI and socket module */
static conn_t   *rawip_do_open(int, cred_t *, int *, int);
static void     rawip_do_close(conn_t *);
static int      rawip_do_bind(conn_t *, struct sockaddr *, socklen_t);
static int      rawip_do_unbind(conn_t *);
static int      rawip_do_connect(conn_t *, const struct sockaddr *, socklen_t,
    cred_t *, pid_t);

int             rawip_getsockname(sock_lower_handle_t, struct sockaddr *,
                    socklen_t *, cred_t *);
int             rawip_getpeername(sock_lower_handle_t, struct sockaddr *,
                    socklen_t *, cred_t *);

static struct module_info icmp_mod_info =  {
        5707, "icmp", 1, INFPSZ, 512, 128
};

/*
 * Entry points for ICMP as a device.
 * We have separate open functions for the /dev/icmp and /dev/icmp6 devices.
 */
static struct qinit icmprinitv4 = {
        NULL, NULL, icmp_openv4, icmp_close, NULL, &icmp_mod_info
};

static struct qinit icmprinitv6 = {
        NULL, NULL, icmp_openv6, icmp_close, NULL, &icmp_mod_info
};

static struct qinit icmpwinit = {
        icmp_wput, ip_wsrv, NULL, NULL, NULL, &icmp_mod_info
};

/* ICMP entry point during fallback */
static struct qinit icmp_fallback_sock_winit = {
        icmp_wput_fallback, NULL, NULL, NULL, NULL, &icmp_mod_info
};

/* For AF_INET aka /dev/icmp */
struct streamtab icmpinfov4 = {
        &icmprinitv4, &icmpwinit
};

/* For AF_INET6 aka /dev/icmp6 */
struct streamtab icmpinfov6 = {
        &icmprinitv6, &icmpwinit
};

/* Default structure copied into T_INFO_ACK messages */
static struct T_info_ack icmp_g_t_info_ack = {
        T_INFO_ACK,
        IP_MAXPACKET,    /* TSDU_size.  icmp allows maximum size messages. */
        T_INVALID,      /* ETSDU_size.  icmp does not support expedited data. */
        T_INVALID,      /* CDATA_size. icmp does not support connect data. */
        T_INVALID,      /* DDATA_size. icmp does not support disconnect data. */
        0,              /* ADDR_size - filled in later. */
        0,              /* OPT_size - not initialized here */
        IP_MAXPACKET,   /* TIDU_size.  icmp allows maximum size messages. */
        T_CLTS,         /* SERV_type.  icmp supports connection-less. */
        TS_UNBND,       /* CURRENT_state.  This is set from icmp_state. */
        (XPG4_1|SENDZERO) /* PROVIDER_flag */
};

static int
icmp_set_buf_prop(netstack_t *stack, cred_t *cr, mod_prop_info_t *pinfo,
    const char *ifname, const void *pval, uint_t flags)
{
        return (mod_set_buf_prop(stack->netstack_icmp->is_propinfo_tbl,
            stack, cr, pinfo, ifname, pval, flags));
}

static int
icmp_get_buf_prop(netstack_t *stack, mod_prop_info_t *pinfo, const char *ifname,
    void *val, uint_t psize, uint_t flags)
{
        return (mod_get_buf_prop(stack->netstack_icmp->is_propinfo_tbl, stack,
            pinfo, ifname, val, psize, flags));
}

/*
 * All of these are alterable, within the min/max values given, at run time.
 *
 * Note: All those tunables which do not start with "icmp_" are Committed and
 * therefore are public. See PSARC 2010/080.
 */
static mod_prop_info_t icmp_propinfo_tbl[] = {
        /* tunable - 0 */
        { "_wroff_extra", MOD_PROTO_RAWIP,
            mod_set_uint32, mod_get_uint32,
            {0, 128, 32}, {32} },

        { "_ipv4_ttl", MOD_PROTO_RAWIP,
            mod_set_uint32, mod_get_uint32,
            {1, 255, 255}, {255} },

        { "_ipv6_hoplimit", MOD_PROTO_RAWIP,
            mod_set_uint32, mod_get_uint32,
            {0, IPV6_MAX_HOPS, IPV6_DEFAULT_HOPS},
            {IPV6_DEFAULT_HOPS} },

        { "_bsd_compat", MOD_PROTO_RAWIP,
            mod_set_boolean, mod_get_boolean,
            {B_TRUE}, {B_TRUE} },

        { "send_buf", MOD_PROTO_RAWIP,
            icmp_set_buf_prop, icmp_get_buf_prop,
            {4096, 65536, 8192}, {8192} },

        { "_xmit_lowat", MOD_PROTO_RAWIP,
            mod_set_uint32, mod_get_uint32,
            {0, 65536, 1024}, {1024} },

        { "recv_buf", MOD_PROTO_RAWIP,
            icmp_set_buf_prop, icmp_get_buf_prop,
            {4096, 65536, 8192}, {8192} },

        { "max_buf", MOD_PROTO_RAWIP,
            mod_set_uint32, mod_get_uint32,
            {65536, ULP_MAX_BUF, 256*1024}, {256*1024} },

        { "_pmtu_discovery", MOD_PROTO_RAWIP,
            mod_set_boolean, mod_get_boolean,
            {B_FALSE}, {B_FALSE} },

        { "_sendto_ignerr", MOD_PROTO_RAWIP,
            mod_set_boolean, mod_get_boolean,
            {B_FALSE}, {B_FALSE} },

        { "?", MOD_PROTO_RAWIP, NULL, mod_get_allprop, {0}, {0} },

        { NULL, 0, NULL, NULL, {0}, {0} }
};

#define is_wroff_extra                  is_propinfo_tbl[0].prop_cur_uval
#define is_ipv4_ttl                     is_propinfo_tbl[1].prop_cur_uval
#define is_ipv6_hoplimit                is_propinfo_tbl[2].prop_cur_uval
#define is_bsd_compat                   is_propinfo_tbl[3].prop_cur_bval
#define is_xmit_hiwat                   is_propinfo_tbl[4].prop_cur_uval
#define is_xmit_lowat                   is_propinfo_tbl[5].prop_cur_uval
#define is_recv_hiwat                   is_propinfo_tbl[6].prop_cur_uval
#define is_max_buf                      is_propinfo_tbl[7].prop_cur_uval
#define is_pmtu_discovery               is_propinfo_tbl[8].prop_cur_bval
#define is_sendto_ignerr                is_propinfo_tbl[9].prop_cur_bval

typedef union T_primitives *t_primp_t;

/*
 * This routine is called to handle each O_T_BIND_REQ/T_BIND_REQ message
 * passed to icmp_wput.
 * It calls IP to verify the local IP address, and calls IP to insert
 * the conn_t in the fanout table.
 * If everything is ok it then sends the T_BIND_ACK back up.
 */
static void
icmp_tpi_bind(queue_t *q, mblk_t *mp)
{
        int     error;
        struct sockaddr *sa;
        struct T_bind_req *tbr;
        socklen_t       len;
        sin_t   *sin;
        sin6_t  *sin6;
        icmp_t          *icmp;
        conn_t  *connp = Q_TO_CONN(q);
        mblk_t *mp1;
        cred_t *cr;

        /*
         * 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) {
                icmp_err_ack(q, mp, TSYSERR, EINVAL);
                return;
        }

        icmp = connp->conn_icmp;
        if ((mp->b_wptr - mp->b_rptr) < sizeof (*tbr)) {
                (void) mi_strlog(q, 1, SL_ERROR|SL_TRACE,
                    "icmp_bind: bad req, len %u",
                    (uint_t)(mp->b_wptr - mp->b_rptr));
                icmp_err_ack(q, mp, TPROTO, 0);
                return;
        }

        if (icmp->icmp_state != TS_UNBND) {
                (void) mi_strlog(q, 1, SL_ERROR|SL_TRACE,
                    "icmp_bind: bad state, %u", icmp->icmp_state);
                icmp_err_ack(q, mp, TOUTSTATE, 0);
                return;
        }

        /*
         * Reallocate the message to make sure we have enough room for an
         * address.
         */
        mp1 = reallocb(mp, sizeof (struct T_bind_ack) + sizeof (sin6_t), 1);
        if (mp1 == NULL) {
                icmp_err_ack(q, mp, TSYSERR, ENOMEM);
                return;
        }
        mp = mp1;

        /* Reset the message type in preparation for shipping it back. */
        DB_TYPE(mp) = M_PCPROTO;
        tbr = (struct T_bind_req *)mp->b_rptr;
        len = tbr->ADDR_length;
        switch (len) {
        case 0: /* request for a generic port */
                tbr->ADDR_offset = sizeof (struct T_bind_req);
                if (connp->conn_family == AF_INET) {
                        tbr->ADDR_length = sizeof (sin_t);
                        sin = (sin_t *)&tbr[1];
                        *sin = sin_null;
                        sin->sin_family = AF_INET;
                        mp->b_wptr = (uchar_t *)&sin[1];
                        sa = (struct sockaddr *)sin;
                        len = sizeof (sin_t);
                } else {
                        ASSERT(connp->conn_family == AF_INET6);
                        tbr->ADDR_length = sizeof (sin6_t);
                        sin6 = (sin6_t *)&tbr[1];
                        *sin6 = sin6_null;
                        sin6->sin6_family = AF_INET6;
                        mp->b_wptr = (uchar_t *)&sin6[1];
                        sa = (struct sockaddr *)sin6;
                        len = sizeof (sin6_t);
                }
                break;

        case sizeof (sin_t):    /* Complete IPv4 address */
                sa = (struct sockaddr *)mi_offset_param(mp, tbr->ADDR_offset,
                    sizeof (sin_t));
                break;

        case sizeof (sin6_t):   /* Complete IPv6 address */
                sa = (struct sockaddr *)mi_offset_param(mp,
                    tbr->ADDR_offset, sizeof (sin6_t));
                break;

        default:
                (void) mi_strlog(q, 1, SL_ERROR|SL_TRACE,
                    "icmp_bind: bad ADDR_length %u", tbr->ADDR_length);
                icmp_err_ack(q, mp, TBADADDR, 0);
                return;
        }

        error = rawip_do_bind(connp, sa, len);
        if (error != 0) {
                if (error > 0) {
                        icmp_err_ack(q, mp, TSYSERR, error);
                } else {
                        icmp_err_ack(q, mp, -error, 0);
                }
        } else {
                tbr->PRIM_type = T_BIND_ACK;
                qreply(q, mp);
        }
}

static int
rawip_do_bind(conn_t *connp, struct sockaddr *sa, socklen_t len)
{
        sin_t           *sin;
        sin6_t          *sin6;
        icmp_t          *icmp = connp->conn_icmp;
        int             error = 0;
        ip_laddr_t      laddr_type = IPVL_UNICAST_UP;   /* INADDR_ANY */
        in_port_t       lport;          /* Network byte order */
        ipaddr_t        v4src;          /* Set if AF_INET */
        in6_addr_t      v6src;
        uint_t          scopeid = 0;
        zoneid_t        zoneid = IPCL_ZONEID(connp);
        ip_stack_t      *ipst = connp->conn_netstack->netstack_ip;

        if (sa == NULL || !OK_32PTR((char *)sa)) {
                return (EINVAL);
        }

        switch (len) {
        case sizeof (sin_t):    /* Complete IPv4 address */
                sin = (sin_t *)sa;
                if (sin->sin_family != AF_INET ||
                    connp->conn_family != AF_INET) {
                        /* TSYSERR, EAFNOSUPPORT */
                        return (EAFNOSUPPORT);
                }
                v4src = sin->sin_addr.s_addr;
                IN6_IPADDR_TO_V4MAPPED(v4src, &v6src);
                if (v4src != INADDR_ANY) {
                        laddr_type = ip_laddr_verify_v4(v4src, zoneid, ipst,
                            B_TRUE);
                }
                lport = sin->sin_port;
                break;
        case sizeof (sin6_t): /* Complete IPv6 address */
                sin6 = (sin6_t *)sa;
                if (sin6->sin6_family != AF_INET6 ||
                    connp->conn_family != AF_INET6) {
                        /* TSYSERR, EAFNOSUPPORT */
                        return (EAFNOSUPPORT);
                }
                /* No support for mapped addresses on raw sockets */
                if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
                        /* TSYSERR, EADDRNOTAVAIL */
                        return (EADDRNOTAVAIL);
                }
                v6src = sin6->sin6_addr;
                if (!IN6_IS_ADDR_UNSPECIFIED(&v6src)) {
                        if (IN6_IS_ADDR_LINKSCOPE(&v6src))
                                scopeid = sin6->sin6_scope_id;
                        laddr_type = ip_laddr_verify_v6(&v6src, zoneid, ipst,
                            B_TRUE, scopeid);
                }
                lport = sin6->sin6_port;
                break;

        default:
                /* TBADADDR */
                return (EADDRNOTAVAIL);
        }

        /* Is the local address a valid unicast, multicast, or broadcast? */
        if (laddr_type == IPVL_BAD)
                return (EADDRNOTAVAIL);

        /*
         * The state must be TS_UNBND.
         */
        mutex_enter(&connp->conn_lock);
        if (icmp->icmp_state != TS_UNBND) {
                mutex_exit(&connp->conn_lock);
                return (-TOUTSTATE);
        }

        /*
         * Copy the source address into our icmp structure.  This address
         * may still be zero; if so, ip will fill in the correct address
         * each time an outbound packet is passed to it.
         * If we are binding to a broadcast or multicast address then
         * we just set the conn_bound_addr since we don't want to use
         * that as the source address when sending.
         */
        connp->conn_bound_addr_v6 = v6src;
        connp->conn_laddr_v6 = v6src;
        if (scopeid != 0) {
                connp->conn_ixa->ixa_flags |= IXAF_SCOPEID_SET;
                connp->conn_ixa->ixa_scopeid = scopeid;
                connp->conn_incoming_ifindex = scopeid;
        } else {
                connp->conn_ixa->ixa_flags &= ~IXAF_SCOPEID_SET;
                connp->conn_incoming_ifindex = connp->conn_bound_if;
        }

        switch (laddr_type) {
        case IPVL_UNICAST_UP:
        case IPVL_UNICAST_DOWN:
                connp->conn_saddr_v6 = v6src;
                connp->conn_mcbc_bind = B_FALSE;
                break;
        case IPVL_MCAST:
        case IPVL_BCAST:
                /* ip_set_destination will pick a source address later */
                connp->conn_saddr_v6 = ipv6_all_zeros;
                connp->conn_mcbc_bind = B_TRUE;
                break;
        }

        /* Any errors after this point should use late_error */

        /*
         * Use sin_port/sin6_port since applications like psh use SOCK_RAW
         * with IPPROTO_TCP.
         */
        connp->conn_lport = lport;
        connp->conn_fport = 0;

        if (connp->conn_family == AF_INET) {
                ASSERT(connp->conn_ipversion == IPV4_VERSION);
        } else {
                ASSERT(connp->conn_ipversion == IPV6_VERSION);
        }

        icmp->icmp_state = TS_IDLE;

        /*
         * We create an initial header template here to make a subsequent
         * sendto have a starting point. Since conn_last_dst is zero the
         * first sendto will always follow the 'dst changed' code path.
         * Note that we defer massaging options and the related checksum
         * adjustment until we have a destination address.
         */
        error = icmp_build_hdr_template(connp, &connp->conn_saddr_v6,
            &connp->conn_faddr_v6, connp->conn_flowinfo);
        if (error != 0) {
                mutex_exit(&connp->conn_lock);
                goto late_error;
        }
        /* Just in case */
        connp->conn_faddr_v6 = ipv6_all_zeros;
        connp->conn_v6lastdst = ipv6_all_zeros;
        mutex_exit(&connp->conn_lock);

        error = ip_laddr_fanout_insert(connp);
        if (error != 0)
                goto late_error;

        /* Bind succeeded */
        return (0);

late_error:
        mutex_enter(&connp->conn_lock);
        connp->conn_saddr_v6 = ipv6_all_zeros;
        connp->conn_bound_addr_v6 = ipv6_all_zeros;
        connp->conn_laddr_v6 = ipv6_all_zeros;
        if (scopeid != 0) {
                connp->conn_ixa->ixa_flags &= ~IXAF_SCOPEID_SET;
                connp->conn_incoming_ifindex = connp->conn_bound_if;
        }
        icmp->icmp_state = TS_UNBND;
        connp->conn_v6lastdst = ipv6_all_zeros;
        connp->conn_lport = 0;

        /* Restore the header that was built above - different source address */
        (void) icmp_build_hdr_template(connp, &connp->conn_saddr_v6,
            &connp->conn_faddr_v6, connp->conn_flowinfo);
        mutex_exit(&connp->conn_lock);
        return (error);
}

/*
 * Tell IP to just bind to the protocol.
 */
static void
icmp_bind_proto(icmp_t *icmp)
{
        conn_t  *connp = icmp->icmp_connp;

        mutex_enter(&connp->conn_lock);
        connp->conn_saddr_v6 = ipv6_all_zeros;
        connp->conn_laddr_v6 = ipv6_all_zeros;
        connp->conn_faddr_v6 = ipv6_all_zeros;
        connp->conn_v6lastdst = ipv6_all_zeros;
        mutex_exit(&connp->conn_lock);

        (void) ip_laddr_fanout_insert(connp);
}

/*
 * This routine handles each T_CONN_REQ message passed to icmp.  It
 * associates a default destination address with the stream.
 *
 * After various error checks are completed, icmp_connect() lays
 * the target address and port into the composite header template.
 * Then we ask IP for information, including a source address if we didn't
 * already have one. Finally we send up the T_OK_ACK reply message.
 */
static void
icmp_tpi_connect(queue_t *q, mblk_t *mp)
{
        conn_t  *connp = Q_TO_CONN(q);
        struct T_conn_req       *tcr;
        struct sockaddr *sa;
        socklen_t len;
        int error;
        cred_t *cr;
        pid_t pid;
        /*
         * 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, &pid);
        ASSERT(cr != NULL);
        if (cr == NULL) {
                icmp_err_ack(q, mp, TSYSERR, EINVAL);
                return;
        }

        tcr = (struct T_conn_req *)mp->b_rptr;
        /* Sanity checks */
        if ((mp->b_wptr - mp->b_rptr) < sizeof (struct T_conn_req)) {
                icmp_err_ack(q, mp, TPROTO, 0);
                return;
        }

        if (tcr->OPT_length != 0) {
                icmp_err_ack(q, mp, TBADOPT, 0);
                return;
        }

        len = tcr->DEST_length;

        switch (len) {
        default:
                icmp_err_ack(q, mp, TBADADDR, 0);
                return;
        case sizeof (sin_t):
                sa = (struct sockaddr *)mi_offset_param(mp, tcr->DEST_offset,
                    sizeof (sin_t));
                break;
        case sizeof (sin6_t):
                sa = (struct sockaddr *)mi_offset_param(mp,
                    tcr->DEST_offset, sizeof (sin6_t));
                break;
        }

        error = proto_verify_ip_addr(connp->conn_family, sa, len);
        if (error != 0) {
                icmp_err_ack(q, mp, TSYSERR, error);
                return;
        }

        error = rawip_do_connect(connp, sa, len, cr, pid);
        if (error != 0) {
                if (error < 0) {
                        icmp_err_ack(q, mp, -error, 0);
                } else {
                        icmp_err_ack(q, mp, 0, error);
                }
        } else {
                mblk_t *mp1;

                /*
                 * We have to send a connection confirmation to
                 * keep TLI happy.
                 */
                if (connp->conn_family == AF_INET) {
                        mp1 = mi_tpi_conn_con(NULL, (char *)sa,
                            sizeof (sin_t), NULL, 0);
                } else {
                        ASSERT(connp->conn_family == AF_INET6);
                        mp1 = mi_tpi_conn_con(NULL, (char *)sa,
                            sizeof (sin6_t), NULL, 0);
                }
                if (mp1 == NULL) {
                        icmp_err_ack(q, mp, TSYSERR, ENOMEM);
                        return;
                }

                /*
                 * Send ok_ack for T_CONN_REQ
                 */
                mp = mi_tpi_ok_ack_alloc(mp);
                if (mp == NULL) {
                        /* Unable to reuse the T_CONN_REQ for the ack. */
                        icmp_err_ack_prim(q, mp1, T_CONN_REQ, TSYSERR, ENOMEM);
                        return;
                }
                putnext(connp->conn_rq, mp);
                putnext(connp->conn_rq, mp1);
        }
}

static int
rawip_do_connect(conn_t *connp, const struct sockaddr *sa, socklen_t len,
    cred_t *cr, pid_t pid)
{
        icmp_t          *icmp;
        sin_t           *sin;
        sin6_t          *sin6;
        int             error;
        uint16_t        dstport;
        ipaddr_t        v4dst;
        in6_addr_t      v6dst;
        uint32_t        flowinfo;
        ip_xmit_attr_t  *ixa;
        ip_xmit_attr_t  *oldixa;
        uint_t          scopeid = 0;
        uint_t          srcid = 0;
        in6_addr_t      v6src = connp->conn_saddr_v6;

        icmp = connp->conn_icmp;

        if (sa == NULL || !OK_32PTR((char *)sa)) {
                return (EINVAL);
        }

        ASSERT(sa != NULL && len != 0);
        sin = NULL;
        sin6 = NULL;
        dstport = 0;
        flowinfo = 0;
        v4dst = INADDR_ANY;

        /*
         * Determine packet type based on type of address passed in
         * the request should contain an IPv4 or IPv6 address.
         * Make sure that address family matches the type of
         * family of the address passed down.
         */
        switch (len) {
        case sizeof (sin_t):
                sin = (sin_t *)sa;

                v4dst = sin->sin_addr.s_addr;
                dstport = sin->sin_port;
                IN6_IPADDR_TO_V4MAPPED(v4dst, &v6dst);
                ASSERT(connp->conn_ipversion == IPV4_VERSION);
                break;

        case sizeof (sin6_t):
                sin6 = (sin6_t *)sa;

                /* No support for mapped addresses on raw sockets */
                if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
                        return (EADDRNOTAVAIL);
                }
                v6dst = sin6->sin6_addr;
                dstport = sin6->sin6_port;
                ASSERT(connp->conn_ipversion == IPV6_VERSION);
                flowinfo = sin6->sin6_flowinfo;
                if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
                        scopeid = sin6->sin6_scope_id;
                srcid = sin6->__sin6_src_id;
                if (srcid != 0 && IN6_IS_ADDR_UNSPECIFIED(&v6src)) {
                        /* Due to check above, we know sin6_addr is v6-only. */
                        if (!ip_srcid_find_id(srcid, &v6src, IPCL_ZONEID(connp),
                            B_FALSE, connp->conn_netstack)) {
                                /* Mismatch - v6src would be v4mapped. */
                                return (EADDRNOTAVAIL);
                        }
                }
                break;
        }

        /*
         * If there is a different thread using conn_ixa then we get a new
         * copy and cut the old one loose from conn_ixa. Otherwise we use
         * conn_ixa and prevent any other thread from using/changing it.
         * Once connect() is done other threads can use conn_ixa since the
         * refcnt will be back at one.
         * We defer updating conn_ixa until later to handle any concurrent
         * conn_ixa_cleanup thread.
         */
        ixa = conn_get_ixa(connp, B_FALSE);
        if (ixa == NULL)
                return (ENOMEM);

        mutex_enter(&connp->conn_lock);
        /*
         * This icmp_t must have bound already before doing a connect.
         * Reject if a connect is in progress (we drop conn_lock during
         * rawip_do_connect).
         */
        if (icmp->icmp_state == TS_UNBND || icmp->icmp_state == TS_WCON_CREQ) {
                mutex_exit(&connp->conn_lock);
                ixa_refrele(ixa);
                return (-TOUTSTATE);
        }

        if (icmp->icmp_state == TS_DATA_XFER) {
                /* Already connected - clear out state */
                if (connp->conn_mcbc_bind)
                        connp->conn_saddr_v6 = ipv6_all_zeros;
                else
                        connp->conn_saddr_v6 = connp->conn_bound_addr_v6;
                connp->conn_laddr_v6 = connp->conn_bound_addr_v6;
                connp->conn_faddr_v6 = ipv6_all_zeros;
                icmp->icmp_state = TS_IDLE;
        }

        /*
         * Use sin_port/sin6_port since applications like psh use SOCK_RAW
         * with IPPROTO_TCP.
         */
        connp->conn_fport = dstport;
        if (connp->conn_ipversion == IPV4_VERSION) {
                /*
                 * Interpret a zero destination to mean loopback.
                 * Update the T_CONN_REQ (sin/sin6) since it is used to
                 * generate the T_CONN_CON.
                 */
                if (v4dst == INADDR_ANY) {
                        v4dst = htonl(INADDR_LOOPBACK);
                        IN6_IPADDR_TO_V4MAPPED(v4dst, &v6dst);
                        ASSERT(connp->conn_family == AF_INET);
                        sin->sin_addr.s_addr = v4dst;
                }
                connp->conn_faddr_v6 = v6dst;
                connp->conn_flowinfo = 0;
        } else {
                ASSERT(connp->conn_ipversion == IPV6_VERSION);
                /*
                 * Interpret a zero destination to mean loopback.
                 * Update the T_CONN_REQ (sin/sin6) since it is used to
                 * generate the T_CONN_CON.
                 */
                if (IN6_IS_ADDR_UNSPECIFIED(&v6dst)) {
                        v6dst = ipv6_loopback;
                        sin6->sin6_addr = v6dst;
                }
                connp->conn_faddr_v6 = v6dst;
                connp->conn_flowinfo = flowinfo;
        }

        /*
         * We update our cred/cpid based on the caller of connect
         */
        if (connp->conn_cred != cr) {
                crhold(cr);
                crfree(connp->conn_cred);
                connp->conn_cred = cr;
        }
        connp->conn_cpid = pid;
        ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
        ixa->ixa_cred = cr;
        ixa->ixa_cpid = pid;
        if (is_system_labeled()) {
                /* We need to restart with a label based on the cred */
                ip_xmit_attr_restore_tsl(ixa, ixa->ixa_cred);
        }

        if (scopeid != 0) {
                ixa->ixa_flags |= IXAF_SCOPEID_SET;
                ixa->ixa_scopeid = scopeid;
                connp->conn_incoming_ifindex = scopeid;
        } else {
                ixa->ixa_flags &= ~IXAF_SCOPEID_SET;
                connp->conn_incoming_ifindex = connp->conn_bound_if;
        }

        /*
         * conn_connect will drop conn_lock and reacquire it.
         * To prevent a send* from messing with this icmp_t while the lock
         * is dropped we set icmp_state and clear conn_v6lastdst.
         * That will make all send* fail with EISCONN.
         */
        connp->conn_v6lastdst = ipv6_all_zeros;
        icmp->icmp_state = TS_WCON_CREQ;

        error = conn_connect(connp, NULL, IPDF_ALLOW_MCBC);
        mutex_exit(&connp->conn_lock);
        if (error != 0)
                goto connect_failed;

        /*
         * The addresses have been verified. Time to insert in
         * the correct fanout list.
         */
        error = ipcl_conn_insert(connp);
        if (error != 0)
                goto connect_failed;

        mutex_enter(&connp->conn_lock);
        error = icmp_build_hdr_template(connp, &connp->conn_saddr_v6,
            &connp->conn_faddr_v6, connp->conn_flowinfo);
        if (error != 0) {
                mutex_exit(&connp->conn_lock);
                goto connect_failed;
        }

        icmp->icmp_state = TS_DATA_XFER;
        /* Record this as the "last" send even though we haven't sent any */
        connp->conn_v6lastdst = connp->conn_faddr_v6;
        connp->conn_lastipversion = connp->conn_ipversion;
        connp->conn_lastdstport = connp->conn_fport;
        connp->conn_lastflowinfo = connp->conn_flowinfo;
        connp->conn_lastscopeid = scopeid;
        connp->conn_lastsrcid = srcid;
        /* Also remember a source to use together with lastdst */
        connp->conn_v6lastsrc = v6src;

        oldixa = conn_replace_ixa(connp, ixa);
        mutex_exit(&connp->conn_lock);
        ixa_refrele(oldixa);

        ixa_refrele(ixa);
        return (0);

connect_failed:
        if (ixa != NULL)
                ixa_refrele(ixa);
        mutex_enter(&connp->conn_lock);
        icmp->icmp_state = TS_IDLE;
        /* In case the source address was set above */
        if (connp->conn_mcbc_bind)
                connp->conn_saddr_v6 = ipv6_all_zeros;
        else
                connp->conn_saddr_v6 = connp->conn_bound_addr_v6;
        connp->conn_laddr_v6 = connp->conn_bound_addr_v6;
        connp->conn_faddr_v6 = ipv6_all_zeros;
        connp->conn_v6lastdst = ipv6_all_zeros;
        connp->conn_flowinfo = 0;

        (void) icmp_build_hdr_template(connp, &connp->conn_saddr_v6,
            &connp->conn_faddr_v6, connp->conn_flowinfo);
        mutex_exit(&connp->conn_lock);
        return (error);
}

static void
rawip_do_close(conn_t *connp)
{
        ASSERT(connp != NULL && IPCL_IS_RAWIP(connp));

        ip_quiesce_conn(connp);

        if (!IPCL_IS_NONSTR(connp)) {
                qprocsoff(connp->conn_rq);
        }

        icmp_close_free(connp);

        /*
         * 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);

        if (!IPCL_IS_NONSTR(connp)) {
                inet_minor_free(connp->conn_minor_arena, connp->conn_dev);
        } else {
                ip_free_helper_stream(connp);
        }

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

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

        if (flags & SO_FALLBACK) {
                /*
                 * stream is being closed while in fallback
                 * simply free the resources that were allocated
                 */
                inet_minor_free(WR(q)->q_ptr, (dev_t)(RD(q)->q_ptr));
                qprocsoff(q);
                goto done;
        }

        connp = Q_TO_CONN(q);
        (void) rawip_do_close(connp);
done:
        q->q_ptr = WR(q)->q_ptr = NULL;
        return (0);
}

static void
icmp_close_free(conn_t *connp)
{
        icmp_t *icmp = connp->conn_icmp;

        if (icmp->icmp_filter != NULL) {
                kmem_free(icmp->icmp_filter, sizeof (icmp6_filter_t));
                icmp->icmp_filter = NULL;
        }

        /*
         * Clear any fields which the kmem_cache constructor clears.
         * Only icmp_connp needs to be preserved.
         * TBD: We should make this more efficient to avoid clearing
         * everything.
         */
        ASSERT(icmp->icmp_connp == connp);
        bzero(icmp, sizeof (icmp_t));
        icmp->icmp_connp = connp;
}

/*
 * This routine handles each T_DISCON_REQ message passed to icmp
 * as an indicating that ICMP is no longer connected. This results
 * in telling IP to restore the binding to just the local address.
 */
static int
icmp_do_disconnect(conn_t *connp)
{
        icmp_t  *icmp = connp->conn_icmp;
        int     error;

        mutex_enter(&connp->conn_lock);
        if (icmp->icmp_state != TS_DATA_XFER) {
                mutex_exit(&connp->conn_lock);
                return (-TOUTSTATE);
        }
        if (connp->conn_mcbc_bind)
                connp->conn_saddr_v6 = ipv6_all_zeros;
        else
                connp->conn_saddr_v6 = connp->conn_bound_addr_v6;
        connp->conn_laddr_v6 = connp->conn_bound_addr_v6;
        connp->conn_faddr_v6 = ipv6_all_zeros;
        icmp->icmp_state = TS_IDLE;

        connp->conn_v6lastdst = ipv6_all_zeros;
        error = icmp_build_hdr_template(connp, &connp->conn_saddr_v6,
            &connp->conn_faddr_v6, connp->conn_flowinfo);
        mutex_exit(&connp->conn_lock);
        if (error != 0)
                return (error);

        /*
         * Tell IP to remove the full binding and revert
         * to the local address binding.
         */
        return (ip_laddr_fanout_insert(connp));
}

static void
icmp_tpi_disconnect(queue_t *q, mblk_t *mp)
{
        conn_t  *connp = Q_TO_CONN(q);
        int     error;

        /*
         * Allocate the largest primitive we need to send back
         * T_error_ack is > than T_ok_ack
         */
        mp = reallocb(mp, sizeof (struct T_error_ack), 1);
        if (mp == NULL) {
                /* Unable to reuse the T_DISCON_REQ for the ack. */
                icmp_err_ack_prim(q, mp, T_DISCON_REQ, TSYSERR, ENOMEM);
                return;
        }

        error = icmp_do_disconnect(connp);

        if (error != 0) {
                if (error > 0) {
                        icmp_err_ack(q, mp, 0, error);
                } else {
                        icmp_err_ack(q, mp, -error, 0);
                }
        } else {
                mp = mi_tpi_ok_ack_alloc(mp);
                ASSERT(mp != NULL);
                qreply(q, mp);
        }
}

static int
icmp_disconnect(conn_t *connp)
{
        int     error;

        connp->conn_dgram_errind = B_FALSE;

        error = icmp_do_disconnect(connp);

        if (error < 0)
                error = proto_tlitosyserr(-error);
        return (error);
}

/* This routine creates a T_ERROR_ACK message and passes it upstream. */
static void
icmp_err_ack(queue_t *q, mblk_t *mp, t_scalar_t t_error, int sys_error)
{
        if ((mp = mi_tpi_err_ack_alloc(mp, t_error, sys_error)) != NULL)
                qreply(q, mp);
}

/* Shorthand to generate and send TPI error acks to our client */
static void
icmp_err_ack_prim(queue_t *q, mblk_t *mp, t_scalar_t primitive,
    t_scalar_t t_error, int sys_error)
{
        struct T_error_ack      *teackp;

        if ((mp = tpi_ack_alloc(mp, sizeof (struct T_error_ack),
            M_PCPROTO, T_ERROR_ACK)) != NULL) {
                teackp = (struct T_error_ack *)mp->b_rptr;
                teackp->ERROR_prim = primitive;
                teackp->TLI_error = t_error;
                teackp->UNIX_error = sys_error;
                qreply(q, mp);
        }
}

/*
 * icmp_icmp_input is called as conn_recvicmp to process ICMP messages.
 * Generates the appropriate T_UDERROR_IND for permanent (non-transient) errors.
 * Assumes that IP has pulled up everything up to and including the ICMP header.
 */
/* ARGSUSED2 */
static void
icmp_icmp_input(void *arg1, mblk_t *mp, void *arg2, ip_recv_attr_t *ira)
{
        conn_t          *connp = (conn_t *)arg1;
        icmp_t          *icmp = connp->conn_icmp;
        icmph_t         *icmph;
        ipha_t          *ipha;
        int             iph_hdr_length;
        sin_t           sin;
        mblk_t          *mp1;
        int             error = 0;

        ipha = (ipha_t *)mp->b_rptr;

        ASSERT(OK_32PTR(mp->b_rptr));

        if (IPH_HDR_VERSION(ipha) != IPV4_VERSION) {
                ASSERT(IPH_HDR_VERSION(ipha) == IPV6_VERSION);
                icmp_icmp_error_ipv6(connp, mp, ira);
                return;
        }
        ASSERT(IPH_HDR_VERSION(ipha) == IPV4_VERSION);

        /* Skip past the outer IP and ICMP headers */
        ASSERT(IPH_HDR_LENGTH(ipha) == ira->ira_ip_hdr_length);
        iph_hdr_length = ira->ira_ip_hdr_length;
        icmph = (icmph_t *)&mp->b_rptr[iph_hdr_length];
        ipha = (ipha_t *)&icmph[1];     /* Inner IP header */

        iph_hdr_length = IPH_HDR_LENGTH(ipha);

        switch (icmph->icmph_type) {
        case ICMP_DEST_UNREACHABLE:
                switch (icmph->icmph_code) {
                case ICMP_FRAGMENTATION_NEEDED: {
                        ipha_t          *ipha;
                        ip_xmit_attr_t  *ixa;
                        /*
                         * IP has already adjusted the path MTU.
                         * But we need to adjust DF for IPv4.
                         */
                        if (connp->conn_ipversion != IPV4_VERSION)
                                break;

                        ixa = conn_get_ixa(connp, B_FALSE);
                        if (ixa == NULL || ixa->ixa_ire == NULL) {
                                /*
                                 * Some other thread holds conn_ixa. We will
                                 * redo this on the next ICMP too big.
                                 */
                                if (ixa != NULL)
                                        ixa_refrele(ixa);
                                break;
                        }
                        (void) ip_get_pmtu(ixa);

                        mutex_enter(&connp->conn_lock);
                        ipha = (ipha_t *)connp->conn_ht_iphc;
                        if (ixa->ixa_flags & IXAF_PMTU_IPV4_DF) {
                                ipha->ipha_fragment_offset_and_flags |=
                                    IPH_DF_HTONS;
                        } else {
                                ipha->ipha_fragment_offset_and_flags &=
                                    ~IPH_DF_HTONS;
                        }
                        mutex_exit(&connp->conn_lock);
                        ixa_refrele(ixa);
                        break;
                }
                case ICMP_PORT_UNREACHABLE:
                case ICMP_PROTOCOL_UNREACHABLE:
                        error = ECONNREFUSED;
                        break;
                default:
                        /* Transient errors */
                        break;
                }
                break;
        default:
                /* Transient errors */
                break;
        }
        if (error == 0) {
                freemsg(mp);
                return;
        }

        /*
         * Deliver T_UDERROR_IND when the application has asked for it.
         * The socket layer enables this automatically when connected.
         */
        if (!connp->conn_dgram_errind) {
                freemsg(mp);
                return;
        }

        sin = sin_null;
        sin.sin_family = AF_INET;
        sin.sin_addr.s_addr = ipha->ipha_dst;

        if (IPCL_IS_NONSTR(connp)) {
                mutex_enter(&connp->conn_lock);
                if (icmp->icmp_state == TS_DATA_XFER) {
                        if (sin.sin_addr.s_addr == connp->conn_faddr_v4) {
                                mutex_exit(&connp->conn_lock);
                                (*connp->conn_upcalls->su_set_error)
                                    (connp->conn_upper_handle, error);
                                goto done;
                        }
                } else {
                        icmp->icmp_delayed_error = error;
                        *((sin_t *)&icmp->icmp_delayed_addr) = sin;
                }
                mutex_exit(&connp->conn_lock);
        } else {
                mp1 = mi_tpi_uderror_ind((char *)&sin, sizeof (sin_t), NULL, 0,
                    error);
                if (mp1 != NULL)
                        putnext(connp->conn_rq, mp1);
        }
done:
        freemsg(mp);
}

/*
 * icmp_icmp_error_ipv6 is called by icmp_icmp_error to process ICMP for IPv6.
 * Generates the appropriate T_UDERROR_IND for permanent (non-transient) errors.
 * Assumes that IP has pulled up all the extension headers as well as the
 * ICMPv6 header.
 */
static void
icmp_icmp_error_ipv6(conn_t *connp, mblk_t *mp, ip_recv_attr_t *ira)
{
        icmp6_t         *icmp6;
        ip6_t           *ip6h, *outer_ip6h;
        uint16_t        iph_hdr_length;
        uint8_t         *nexthdrp;
        sin6_t          sin6;
        mblk_t          *mp1;
        int             error = 0;
        icmp_t          *icmp = connp->conn_icmp;

        outer_ip6h = (ip6_t *)mp->b_rptr;
#ifdef DEBUG
        if (outer_ip6h->ip6_nxt != IPPROTO_ICMPV6)
                iph_hdr_length = ip_hdr_length_v6(mp, outer_ip6h);
        else
                iph_hdr_length = IPV6_HDR_LEN;
        ASSERT(iph_hdr_length == ira->ira_ip_hdr_length);
#endif
        /* Skip past the outer IP and ICMP headers */
        iph_hdr_length = ira->ira_ip_hdr_length;
        icmp6 = (icmp6_t *)&mp->b_rptr[iph_hdr_length];

        ip6h = (ip6_t *)&icmp6[1];      /* Inner IP header */
        if (!ip_hdr_length_nexthdr_v6(mp, ip6h, &iph_hdr_length, &nexthdrp)) {
                freemsg(mp);
                return;
        }

        switch (icmp6->icmp6_type) {
        case ICMP6_DST_UNREACH:
                switch (icmp6->icmp6_code) {
                case ICMP6_DST_UNREACH_NOPORT:
                        error = ECONNREFUSED;
                        break;
                case ICMP6_DST_UNREACH_ADMIN:
                case ICMP6_DST_UNREACH_NOROUTE:
                case ICMP6_DST_UNREACH_BEYONDSCOPE:
                case ICMP6_DST_UNREACH_ADDR:
                        /* Transient errors */
                        break;
                default:
                        break;
                }
                break;
        case ICMP6_PACKET_TOO_BIG: {
                struct T_unitdata_ind   *tudi;
                struct T_opthdr         *toh;
                size_t                  udi_size;
                mblk_t                  *newmp;
                t_scalar_t              opt_length = sizeof (struct T_opthdr) +
                    sizeof (struct ip6_mtuinfo);
                sin6_t                  *sin6;
                struct ip6_mtuinfo      *mtuinfo;

                /*
                 * If the application has requested to receive path mtu
                 * information, send up an empty message containing an
                 * IPV6_PATHMTU ancillary data item.
                 */
                if (!connp->conn_ipv6_recvpathmtu)
                        break;

                udi_size = sizeof (struct T_unitdata_ind) + sizeof (sin6_t) +
                    opt_length;
                if ((newmp = allocb(udi_size, BPRI_MED)) == NULL) {
                        BUMP_MIB(&icmp->icmp_is->is_rawip_mib, rawipInErrors);
                        break;
                }

                /*
                 * newmp->b_cont is left to NULL on purpose.  This is an
                 * empty message containing only ancillary data.
                 */
                newmp->b_datap->db_type = M_PROTO;
                tudi = (struct T_unitdata_ind *)newmp->b_rptr;
                newmp->b_wptr = (uchar_t *)tudi + udi_size;
                tudi->PRIM_type = T_UNITDATA_IND;
                tudi->SRC_length = sizeof (sin6_t);
                tudi->SRC_offset = sizeof (struct T_unitdata_ind);
                tudi->OPT_offset = tudi->SRC_offset + sizeof (sin6_t);
                tudi->OPT_length = opt_length;

                sin6 = (sin6_t *)&tudi[1];
                bzero(sin6, sizeof (sin6_t));
                sin6->sin6_family = AF_INET6;
                sin6->sin6_addr = connp->conn_faddr_v6;

                toh = (struct T_opthdr *)&sin6[1];
                toh->level = IPPROTO_IPV6;
                toh->name = IPV6_PATHMTU;
                toh->len = opt_length;
                toh->status = 0;

                mtuinfo = (struct ip6_mtuinfo *)&toh[1];
                bzero(mtuinfo, sizeof (struct ip6_mtuinfo));
                mtuinfo->ip6m_addr.sin6_family = AF_INET6;
                mtuinfo->ip6m_addr.sin6_addr = ip6h->ip6_dst;
                mtuinfo->ip6m_mtu = icmp6->icmp6_mtu;
                /*
                 * We've consumed everything we need from the original
                 * message.  Free it, then send our empty message.
                 */
                freemsg(mp);
                icmp_ulp_recv(connp, newmp, msgdsize(newmp));
                return;
        }
        case ICMP6_TIME_EXCEEDED:
                /* Transient errors */
                break;
        case ICMP6_PARAM_PROB:
                /* If this corresponds to an ICMP_PROTOCOL_UNREACHABLE */
                if (icmp6->icmp6_code == ICMP6_PARAMPROB_NEXTHEADER &&
                    (uchar_t *)ip6h + icmp6->icmp6_pptr ==
                    (uchar_t *)nexthdrp) {
                        error = ECONNREFUSED;
                        break;
                }
                break;
        }
        if (error == 0) {
                freemsg(mp);
                return;
        }

        /*
         * Deliver T_UDERROR_IND when the application has asked for it.
         * The socket layer enables this automatically when connected.
         */
        if (!connp->conn_dgram_errind) {
                freemsg(mp);
                return;
        }

        sin6 = sin6_null;
        sin6.sin6_family = AF_INET6;
        sin6.sin6_addr = ip6h->ip6_dst;
        sin6.sin6_flowinfo = ip6h->ip6_vcf & ~IPV6_VERS_AND_FLOW_MASK;
        if (IPCL_IS_NONSTR(connp)) {
                mutex_enter(&connp->conn_lock);
                if (icmp->icmp_state == TS_DATA_XFER) {
                        if (IN6_ARE_ADDR_EQUAL(&sin6.sin6_addr,
                            &connp->conn_faddr_v6)) {
                                mutex_exit(&connp->conn_lock);
                                (*connp->conn_upcalls->su_set_error)
                                    (connp->conn_upper_handle, error);
                                goto done;
                        }
                } else {
                        icmp->icmp_delayed_error = error;
                        *((sin6_t *)&icmp->icmp_delayed_addr) = sin6;
                }
                mutex_exit(&connp->conn_lock);
        } else {
                mp1 = mi_tpi_uderror_ind((char *)&sin6, sizeof (sin6_t),
                    NULL, 0, error);
                if (mp1 != NULL)
                        putnext(connp->conn_rq, mp1);
        }
done:
        freemsg(mp);
}

/*
 * This routine responds to T_ADDR_REQ messages.  It is called by icmp_wput.
 * The local address is filled in if endpoint is bound. The remote address
 * is filled in if remote address has been precified ("connected endpoint")
 * (The concept of connected CLTS sockets is alien to published TPI
 *  but we support it anyway).
 */
static void
icmp_addr_req(queue_t *q, mblk_t *mp)
{
        struct sockaddr *sa;
        mblk_t  *ackmp;
        struct T_addr_ack *taa;
        icmp_t  *icmp = Q_TO_ICMP(q);
        conn_t  *connp = icmp->icmp_connp;
        uint_t  addrlen;

        /* Make it large enough for worst case */
        ackmp = reallocb(mp, sizeof (struct T_addr_ack) +
            2 * sizeof (sin6_t), 1);
        if (ackmp == NULL) {
                icmp_err_ack(q, mp, TSYSERR, ENOMEM);
                return;
        }
        taa = (struct T_addr_ack *)ackmp->b_rptr;

        bzero(taa, sizeof (struct T_addr_ack));
        ackmp->b_wptr = (uchar_t *)&taa[1];

        taa->PRIM_type = T_ADDR_ACK;
        ackmp->b_datap->db_type = M_PCPROTO;

        if (connp->conn_family == AF_INET)
                addrlen = sizeof (sin_t);
        else
                addrlen = sizeof (sin6_t);

        mutex_enter(&connp->conn_lock);
        /*
         * Note: Following code assumes 32 bit alignment of basic
         * data structures like sin_t and struct T_addr_ack.
         */
        if (icmp->icmp_state != TS_UNBND) {
                /*
                 * Fill in local address first
                 */
                taa->LOCADDR_offset = sizeof (*taa);
                taa->LOCADDR_length = addrlen;
                sa = (struct sockaddr *)&taa[1];
                (void) conn_getsockname(connp, sa, &addrlen);
                ackmp->b_wptr += addrlen;
        }
        if (icmp->icmp_state == TS_DATA_XFER) {
                /*
                 * connected, fill remote address too
                 */
                taa->REMADDR_length = addrlen;
                /* assumed 32-bit alignment */
                taa->REMADDR_offset = taa->LOCADDR_offset + taa->LOCADDR_length;
                sa = (struct sockaddr *)(ackmp->b_rptr + taa->REMADDR_offset);
                (void) conn_getpeername(connp, sa, &addrlen);
                ackmp->b_wptr += addrlen;
        }
        mutex_exit(&connp->conn_lock);
        ASSERT(ackmp->b_wptr <= ackmp->b_datap->db_lim);
        qreply(q, ackmp);
}

static void
icmp_copy_info(struct T_info_ack *tap, icmp_t *icmp)
{
        conn_t          *connp = icmp->icmp_connp;

        *tap = icmp_g_t_info_ack;

        if (connp->conn_family == AF_INET6)
                tap->ADDR_size = sizeof (sin6_t);
        else
                tap->ADDR_size = sizeof (sin_t);
        tap->CURRENT_state = icmp->icmp_state;
        tap->OPT_size = icmp_max_optsize;
}

static void
icmp_do_capability_ack(icmp_t *icmp, struct T_capability_ack *tcap,
    t_uscalar_t cap_bits1)
{
        tcap->CAP_bits1 = 0;

        if (cap_bits1 & TC1_INFO) {
                icmp_copy_info(&tcap->INFO_ack, icmp);
                tcap->CAP_bits1 |= TC1_INFO;
        }
}

/*
 * This routine responds to T_CAPABILITY_REQ messages.  It is called by
 * icmp_wput.  Much of the T_CAPABILITY_ACK information is copied from
 * icmp_g_t_info_ack.  The current state of the stream is copied from
 * icmp_state.
 */
static void
icmp_capability_req(queue_t *q, mblk_t *mp)
{
        icmp_t                  *icmp = Q_TO_ICMP(q);
        t_uscalar_t             cap_bits1;
        struct T_capability_ack *tcap;

        cap_bits1 = ((struct T_capability_req *)mp->b_rptr)->CAP_bits1;

        mp = tpi_ack_alloc(mp, sizeof (struct T_capability_ack),
            mp->b_datap->db_type, T_CAPABILITY_ACK);
        if (!mp)
                return;

        tcap = (struct T_capability_ack *)mp->b_rptr;

        icmp_do_capability_ack(icmp, tcap, cap_bits1);

        qreply(q, mp);
}

/*
 * This routine responds to T_INFO_REQ messages.  It is called by icmp_wput.
 * Most of the T_INFO_ACK information is copied from icmp_g_t_info_ack.
 * The current state of the stream is copied from icmp_state.
 */
static void
icmp_info_req(queue_t *q, mblk_t *mp)
{
        icmp_t  *icmp = Q_TO_ICMP(q);

        /* Create a T_INFO_ACK message. */
        mp = tpi_ack_alloc(mp, sizeof (struct T_info_ack), M_PCPROTO,
            T_INFO_ACK);
        if (!mp)
                return;
        icmp_copy_info((struct T_info_ack *)mp->b_rptr, icmp);
        qreply(q, mp);
}

static int
icmp_tpi_open(queue_t *q, dev_t *devp, int flag, int sflag, cred_t *credp,
    int family)
{
        conn_t *connp;
        dev_t   conn_dev;
        int     error;

        /* If the stream is already open, return immediately. */
        if (q->q_ptr != NULL)
                return (0);

        if (sflag == MODOPEN)
                return (EINVAL);

        /*
         * Since ICMP is not used so heavily, allocating from the small
         * arena should be sufficient.
         */
        if ((conn_dev = inet_minor_alloc(ip_minor_arena_sa)) == 0) {
                return (EBUSY);
        }

        if (flag & SO_FALLBACK) {
                /*
                 * Non streams socket needs a stream to fallback to
                 */
                RD(q)->q_ptr = (void *)conn_dev;
                WR(q)->q_qinfo = &icmp_fallback_sock_winit;
                WR(q)->q_ptr = (void *)ip_minor_arena_sa;
                qprocson(q);
                return (0);
        }

        connp = rawip_do_open(family, credp, &error, KM_SLEEP);
        if (connp == NULL) {
                ASSERT(error != 0);
                inet_minor_free(ip_minor_arena_sa, conn_dev);
                return (error);
        }

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

        /*
         * Initialize the icmp_t structure for this stream.
         */
        q->q_ptr = connp;
        WR(q)->q_ptr = connp;
        connp->conn_rq = q;
        connp->conn_wq = WR(q);

        WR(q)->q_hiwat = connp->conn_sndbuf;
        WR(q)->q_lowat = connp->conn_sndlowat;

        qprocson(q);

        /* Set the Stream head write offset. */
        (void) proto_set_tx_wroff(q, connp, connp->conn_wroff);
        (void) proto_set_rx_hiwat(connp->conn_rq, connp, connp->conn_rcvbuf);

        mutex_enter(&connp->conn_lock);
        connp->conn_state_flags &= ~CONN_INCIPIENT;
        mutex_exit(&connp->conn_lock);

        icmp_bind_proto(connp->conn_icmp);

        return (0);
}

/* For /dev/icmp aka AF_INET open */
static int
icmp_openv4(queue_t *q, dev_t *devp, int flag, int sflag, cred_t *credp)
{
        return (icmp_tpi_open(q, devp, flag, sflag, credp, AF_INET));
}

/* For /dev/icmp6 aka AF_INET6 open */
static int
icmp_openv6(queue_t *q, dev_t *devp, int flag, int sflag, cred_t *credp)
{
        return (icmp_tpi_open(q, devp, flag, sflag, credp, AF_INET6));
}

/*
 * This is the open routine for icmp.  It allocates a icmp_t structure for
 * the stream and, on the first open of the module, creates an ND table.
 */
static conn_t *
rawip_do_open(int family, cred_t *credp, int *err, int flags)
{
        icmp_t  *icmp;
        conn_t *connp;
        zoneid_t zoneid;
        netstack_t *ns;
        icmp_stack_t *is;
        int len;
        boolean_t isv6 = B_FALSE;

        *err = secpolicy_net_icmpaccess(credp);
        if (*err != 0)
                return (NULL);

        if (family == AF_INET6)
                isv6 = B_TRUE;

        ns = netstack_find_by_cred(credp);
        ASSERT(ns != NULL);
        is = ns->netstack_icmp;
        ASSERT(is != NULL);

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

        ASSERT(flags == KM_SLEEP || flags == KM_NOSLEEP);

        connp = ipcl_conn_create(IPCL_RAWIPCONN, flags, ns);
        icmp = connp->conn_icmp;

        /*
         * ipcl_conn_create did a netstack_hold. Undo the hold that was
         * done by netstack_find_by_cred()
         */
        netstack_rele(ns);

        /*
         * Since this conn_t/icmp_t is not yet visible to anybody else we don't
         * need to lock anything.
         */
        ASSERT(connp->conn_proto == IPPROTO_ICMP);
        ASSERT(connp->conn_icmp == icmp);
        ASSERT(icmp->icmp_connp == connp);

        /* Set the initial state of the stream and the privilege status. */
        icmp->icmp_state = TS_UNBND;
        connp->conn_ixa->ixa_flags |= IXAF_VERIFY_SOURCE;
        if (isv6) {
                connp->conn_family = AF_INET6;
                connp->conn_ipversion = IPV6_VERSION;
                connp->conn_ixa->ixa_flags &= ~IXAF_IS_IPV4;
                connp->conn_proto = IPPROTO_ICMPV6;
                /* May be changed by a SO_PROTOTYPE socket option. */
                connp->conn_proto = IPPROTO_ICMPV6;
                connp->conn_ixa->ixa_protocol = connp->conn_proto;
                connp->conn_ixa->ixa_raw_cksum_offset = 2;
                connp->conn_default_ttl = is->is_ipv6_hoplimit;
                len = sizeof (ip6_t);
        } else {
                connp->conn_family = AF_INET;
                connp->conn_ipversion = IPV4_VERSION;
                connp->conn_ixa->ixa_flags |= IXAF_IS_IPV4;
                /* May be changed by a SO_PROTOTYPE socket option. */
                connp->conn_proto = IPPROTO_ICMP;
                connp->conn_ixa->ixa_protocol = connp->conn_proto;
                connp->conn_default_ttl = is->is_ipv4_ttl;
                len = sizeof (ipha_t);
        }
        connp->conn_xmit_ipp.ipp_unicast_hops = connp->conn_default_ttl;

        connp->conn_ixa->ixa_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;

        /*
         * For the socket of protocol IPPROTO_RAW or when IP_HDRINCL is set,
         * the checksum is provided in the pre-built packet. We clear
         * IXAF_SET_ULP_CKSUM to tell IP that the application has sent a
         * complete IP header and not to compute the transport checksum.
         */
        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;

        /*
         * If the caller has the process-wide flag set, then default to MAC
         * exempt mode.  This allows read-down to unlabeled hosts.
         */
        if (getpflags(NET_MAC_AWARE, credp) != 0)
                connp->conn_mac_mode = CONN_MAC_AWARE;

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

        icmp->icmp_is = is;

        connp->conn_rcvbuf = is->is_recv_hiwat;
        connp->conn_sndbuf = is->is_xmit_hiwat;
        connp->conn_sndlowat = is->is_xmit_lowat;
        connp->conn_rcvlowat = icmp_mod_info.mi_lowat;

        connp->conn_wroff = len + is->is_wroff_extra;
        connp->conn_so_type = SOCK_RAW;

        connp->conn_recv = icmp_input;
        connp->conn_recvicmp = icmp_icmp_input;
        crhold(credp);
        connp->conn_cred = credp;
        connp->conn_cpid = curproc->p_pid;
        connp->conn_open_time = ddi_get_lbolt64();
        /* 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;
        if (is_system_labeled())
                connp->conn_ixa->ixa_tsl = crgetlabel(connp->conn_cred);

        connp->conn_flow_cntrld = B_FALSE;

        if (is->is_pmtu_discovery)
                connp->conn_ixa->ixa_flags |= IXAF_PMTU_DISCOVERY;

        return (connp);
}

/*
 * Which ICMP options OK to set through T_UNITDATA_REQ...
 */
/* ARGSUSED */
static boolean_t
icmp_opt_allow_udr_set(t_scalar_t level, t_scalar_t name)
{
        return (B_TRUE);
}

/*
 * This routine gets default values of certain options whose default
 * values are maintained by protcol specific code
 */
int
icmp_opt_default(queue_t *q, t_scalar_t level, t_scalar_t name, uchar_t *ptr)
{
        icmp_t *icmp = Q_TO_ICMP(q);
        icmp_stack_t *is = icmp->icmp_is;
        int *i1 = (int *)ptr;

        switch (level) {
        case IPPROTO_IP:
                switch (name) {
                case IP_MULTICAST_TTL:
                        *ptr = (uchar_t)IP_DEFAULT_MULTICAST_TTL;
                        return (sizeof (uchar_t));
                case IP_MULTICAST_LOOP:
                        *ptr = (uchar_t)IP_DEFAULT_MULTICAST_LOOP;
                        return (sizeof (uchar_t));
                }
                break;
        case IPPROTO_IPV6:
                switch (name) {
                case IPV6_MULTICAST_HOPS:
                        *i1 = IP_DEFAULT_MULTICAST_TTL;
                        return (sizeof (int));
                case IPV6_MULTICAST_LOOP:
                        *i1 = IP_DEFAULT_MULTICAST_LOOP;
                        return (sizeof (int));
                case IPV6_UNICAST_HOPS:
                        *i1 = is->is_ipv6_hoplimit;
                        return (sizeof (int));
                }
                break;
        case IPPROTO_ICMPV6:
                switch (name) {
                case ICMP6_FILTER:
                        /* Make it look like "pass all" */
                        ICMP6_FILTER_SETPASSALL((icmp6_filter_t *)ptr);
                        return (sizeof (icmp6_filter_t));
                }
                break;
        }
        return (-1);
}

/*
 * This routine retrieves the current status of socket options.
 * It returns the size of the option retrieved, or -1.
 */
int
icmp_opt_get(conn_t *connp, int level, int name, uchar_t *ptr)
{
        icmp_t          *icmp = connp->conn_icmp;
        int             *i1 = (int *)ptr;
        conn_opt_arg_t  coas;
        int             retval;

        coas.coa_connp = connp;
        coas.coa_ixa = connp->conn_ixa;
        coas.coa_ipp = &connp->conn_xmit_ipp;
        coas.coa_ancillary = B_FALSE;
        coas.coa_changed = 0;

        /*
         * We assume that the optcom framework has checked for the set
         * of levels and names that are supported, hence we don't worry
         * about rejecting based on that.
         * First check for ICMP specific handling, then pass to common routine.
         */
        switch (level) {
        case IPPROTO_IP:
                /*
                 * Only allow IPv4 option processing on IPv4 sockets.
                 */
                if (connp->conn_family != AF_INET)
                        return (-1);

                switch (name) {
                case IP_OPTIONS:
                case T_IP_OPTIONS:
                        /* Options are passed up with each packet */
                        return (0);
                case IP_HDRINCL:
                        mutex_enter(&connp->conn_lock);
                        *i1 = (int)icmp->icmp_hdrincl;
                        mutex_exit(&connp->conn_lock);
                        return (sizeof (int));
                }
                break;

        case IPPROTO_IPV6:
                /*
                 * Only allow IPv6 option processing on native IPv6 sockets.
                 */
                if (connp->conn_family != AF_INET6)
                        return (-1);

                switch (name) {
                case IPV6_CHECKSUM:
                        /*
                         * Return offset or -1 if no checksum offset.
                         * Does not apply to IPPROTO_ICMPV6
                         */
                        if (connp->conn_proto == IPPROTO_ICMPV6)
                                return (-1);

                        mutex_enter(&connp->conn_lock);
                        if (connp->conn_ixa->ixa_flags & IXAF_SET_RAW_CKSUM)
                                *i1 = connp->conn_ixa->ixa_raw_cksum_offset;
                        else
                                *i1 = -1;
                        mutex_exit(&connp->conn_lock);
                        return (sizeof (int));
                }
                break;

        case IPPROTO_ICMPV6:
                /*
                 * Only allow IPv6 option processing on native IPv6 sockets.
                 */
                if (connp->conn_family != AF_INET6)
                        return (-1);

                if (connp->conn_proto != IPPROTO_ICMPV6)
                        return (-1);

                switch (name) {
                case ICMP6_FILTER:
                        mutex_enter(&connp->conn_lock);
                        if (icmp->icmp_filter == NULL) {
                                /* Make it look like "pass all" */
                                ICMP6_FILTER_SETPASSALL((icmp6_filter_t *)ptr);
                        } else {
                                (void) bcopy(icmp->icmp_filter, ptr,
                                    sizeof (icmp6_filter_t));
                        }
                        mutex_exit(&connp->conn_lock);
                        return (sizeof (icmp6_filter_t));
                }
        }
        mutex_enter(&connp->conn_lock);
        retval = conn_opt_get(&coas, level, name, ptr);
        mutex_exit(&connp->conn_lock);
        return (retval);
}

/*
 * This routine retrieves the current status of socket options.
 * It returns the size of the option retrieved, or -1.
 */
int
icmp_tpi_opt_get(queue_t *q, int level, int name, uchar_t *ptr)
{
        conn_t          *connp = Q_TO_CONN(q);
        int             err;

        err = icmp_opt_get(connp, level, name, ptr);
        return (err);
}

/*
 * This routine sets socket options.
 */
int
icmp_do_opt_set(conn_opt_arg_t *coa, int level, int name,
    uint_t inlen, uchar_t *invalp, cred_t *cr, boolean_t checkonly)
{
        conn_t          *connp = coa->coa_connp;
        ip_xmit_attr_t  *ixa = coa->coa_ixa;
        icmp_t          *icmp = connp->conn_icmp;
        icmp_stack_t    *is = icmp->icmp_is;
        int             *i1 = (int *)invalp;
        boolean_t       onoff = (*i1 == 0) ? 0 : 1;
        int             error;

        ASSERT(MUTEX_NOT_HELD(&coa->coa_connp->conn_lock));

        /*
         * For fixed length options, no sanity check
         * of passed in length is done. It is assumed *_optcom_req()
         * routines do the right thing.
         */

        switch (level) {
        case SOL_SOCKET:
                switch (name) {
                case SO_PROTOTYPE:
                        if ((*i1 & 0xFF) != IPPROTO_ICMP &&
                            (*i1 & 0xFF) != IPPROTO_ICMPV6 &&
                            secpolicy_net_rawaccess(cr) != 0) {
                                return (EACCES);
                        }
                        if (checkonly)
                                break;

                        mutex_enter(&connp->conn_lock);
                        connp->conn_proto = *i1 & 0xFF;
                        ixa->ixa_protocol = connp->conn_proto;
                        if ((connp->conn_proto == IPPROTO_RAW ||
                            connp->conn_proto == IPPROTO_IGMP) &&
                            connp->conn_family == AF_INET) {
                                icmp->icmp_hdrincl = 1;
                                ixa->ixa_flags &= ~IXAF_SET_ULP_CKSUM;
                        } else if (connp->conn_proto == IPPROTO_UDP ||
                            connp->conn_proto == IPPROTO_TCP ||
                            connp->conn_proto == IPPROTO_SCTP) {
                                /* Used by test applications like psh */
                                icmp->icmp_hdrincl = 0;
                                ixa->ixa_flags &= ~IXAF_SET_ULP_CKSUM;
                        } else {
                                icmp->icmp_hdrincl = 0;
                                ixa->ixa_flags |= IXAF_SET_ULP_CKSUM;
                        }

                        if (connp->conn_family == AF_INET6 &&
                            connp->conn_proto == IPPROTO_ICMPV6) {
                                /* Set offset for icmp6_cksum */
                                ixa->ixa_flags &= ~IXAF_SET_RAW_CKSUM;
                                ixa->ixa_raw_cksum_offset = 2;
                        }
                        if (icmp->icmp_filter != NULL &&
                            connp->conn_proto != IPPROTO_ICMPV6) {
                                kmem_free(icmp->icmp_filter,
                                    sizeof (icmp6_filter_t));
                                icmp->icmp_filter = NULL;
                        }
                        mutex_exit(&connp->conn_lock);

                        coa->coa_changed |= COA_HEADER_CHANGED;
                        /*
                         * For SCTP, we don't use icmp_bind_proto() for
                         * raw socket binding.
                         */
                        if (connp->conn_proto == IPPROTO_SCTP)
                                return (0);

                        coa->coa_changed |= COA_ICMP_BIND_NEEDED;
                        return (0);

                case SO_SNDBUF:
                        if (*i1 > is->is_max_buf) {
                                return (ENOBUFS);
                        }
                        break;
                case SO_RCVBUF:
                        if (*i1 > is->is_max_buf) {
                                return (ENOBUFS);
                        }
                        break;
                }
                break;

        case IPPROTO_IP:
                /*
                 * Only allow IPv4 option processing on IPv4 sockets.
                 */
                if (connp->conn_family != AF_INET)
                        return (EINVAL);

                switch (name) {
                case IP_HDRINCL:
                        if (!checkonly) {
                                mutex_enter(&connp->conn_lock);
                                icmp->icmp_hdrincl = onoff;
                                if (onoff)
                                        ixa->ixa_flags &= ~IXAF_SET_ULP_CKSUM;
                                else
                                        ixa->ixa_flags |= IXAF_SET_ULP_CKSUM;
                                mutex_exit(&connp->conn_lock);
                        }
                        break;
                }
                break;

        case IPPROTO_IPV6:
                if (connp->conn_family != AF_INET6)
                        return (EINVAL);

                switch (name) {
                case IPV6_CHECKSUM:
                        /*
                         * Integer offset into the user data of where the
                         * checksum is located.
                         * Offset of -1 disables option.
                         * Does not apply to IPPROTO_ICMPV6.
                         */
                        if (connp->conn_proto == IPPROTO_ICMPV6 ||
                            coa->coa_ancillary) {
                                return (EINVAL);
                        }
                        if ((*i1 != -1) && ((*i1 < 0) || (*i1 & 0x1) != 0)) {
                                /* Negative or not 16 bit aligned offset */
                                return (EINVAL);
                        }
                        if (checkonly)
                                break;

                        mutex_enter(&connp->conn_lock);
                        if (*i1 == -1) {
                                ixa->ixa_flags &= ~IXAF_SET_RAW_CKSUM;
                                ixa->ixa_raw_cksum_offset = 0;
                                ixa->ixa_flags &= ~IXAF_SET_ULP_CKSUM;
                        } else {
                                ixa->ixa_flags |= IXAF_SET_RAW_CKSUM;
                                ixa->ixa_raw_cksum_offset = *i1;
                                ixa->ixa_flags |= IXAF_SET_ULP_CKSUM;
                        }
                        mutex_exit(&connp->conn_lock);
                        break;
                }
                break;

        case IPPROTO_ICMPV6:
                /*
                 * Only allow IPv6 option processing on IPv6 sockets.
                 */
                if (connp->conn_family != AF_INET6)
                        return (EINVAL);
                if (connp->conn_proto != IPPROTO_ICMPV6)
                        return (EINVAL);

                switch (name) {
                case ICMP6_FILTER:
                        if (checkonly)
                                break;

                        if ((inlen != 0) &&
                            (inlen != sizeof (icmp6_filter_t)))
                                return (EINVAL);

                        mutex_enter(&connp->conn_lock);
                        if (inlen == 0) {
                                if (icmp->icmp_filter != NULL) {
                                        kmem_free(icmp->icmp_filter,
                                            sizeof (icmp6_filter_t));
                                        icmp->icmp_filter = NULL;
                                }
                        } else {
                                if (icmp->icmp_filter == NULL) {
                                        icmp->icmp_filter = kmem_alloc(
                                            sizeof (icmp6_filter_t),
                                            KM_NOSLEEP);
                                        if (icmp->icmp_filter == NULL) {
                                                mutex_exit(&connp->conn_lock);
                                                return (ENOBUFS);
                                        }
                                }
                                (void) bcopy(invalp, icmp->icmp_filter, inlen);
                        }
                        mutex_exit(&connp->conn_lock);
                        break;
                }
                break;
        }
        error = conn_opt_set(coa, level, name, inlen, invalp,
            checkonly, cr);
        return (error);
}

/*
 * This routine sets socket options.
 */
int
icmp_opt_set(conn_t *connp, uint_t optset_context, int level, int name,
    uint_t inlen, uchar_t *invalp, uint_t *outlenp, uchar_t *outvalp,
    void *thisdg_attrs, cred_t *cr)
{
        icmp_t          *icmp = connp->conn_icmp;
        int             err;
        conn_opt_arg_t  coas, *coa;
        boolean_t       checkonly;
        icmp_stack_t    *is = icmp->icmp_is;

        switch (optset_context) {
        case SETFN_OPTCOM_CHECKONLY:
                checkonly = B_TRUE;
                /*
                 * Note: Implies T_CHECK semantics for T_OPTCOM_REQ
                 * inlen != 0 implies value supplied and
                 *      we have to "pretend" to set it.
                 * inlen == 0 implies that there is no
                 *      value part in T_CHECK request and just validation
                 * done elsewhere should be enough, we just return here.
                 */
                if (inlen == 0) {
                        *outlenp = 0;
                        return (0);
                }
                break;
        case SETFN_OPTCOM_NEGOTIATE:
                checkonly = B_FALSE;
                break;
        case SETFN_UD_NEGOTIATE:
        case SETFN_CONN_NEGOTIATE:
                checkonly = B_FALSE;
                /*
                 * Negotiating local and "association-related" options
                 * through T_UNITDATA_REQ.
                 *
                 * Following routine can filter out ones we do not
                 * want to be "set" this way.
                 */
                if (!icmp_opt_allow_udr_set(level, name)) {
                        *outlenp = 0;
                        return (EINVAL);
                }
                break;
        default:
                /*
                 * We should never get here
                 */
                *outlenp = 0;
                return (EINVAL);
        }

        ASSERT((optset_context != SETFN_OPTCOM_CHECKONLY) ||
            (optset_context == SETFN_OPTCOM_CHECKONLY && inlen != 0));

        if (thisdg_attrs != NULL) {
                /* Options from T_UNITDATA_REQ */
                coa = (conn_opt_arg_t *)thisdg_attrs;
                ASSERT(coa->coa_connp == connp);
                ASSERT(coa->coa_ixa != NULL);
                ASSERT(coa->coa_ipp != NULL);
                ASSERT(coa->coa_ancillary);
        } else {
                coa = &coas;
                coas.coa_connp = connp;
                /* Get a reference on conn_ixa to prevent concurrent mods */
                coas.coa_ixa = conn_get_ixa(connp, B_TRUE);
                if (coas.coa_ixa == NULL) {
                        *outlenp = 0;
                        return (ENOMEM);
                }
                coas.coa_ipp = &connp->conn_xmit_ipp;
                coas.coa_ancillary = B_FALSE;
                coas.coa_changed = 0;
        }

        err = icmp_do_opt_set(coa, level, name, inlen, invalp,
            cr, checkonly);
        if (err != 0) {
errout:
                if (!coa->coa_ancillary)
                        ixa_refrele(coa->coa_ixa);
                *outlenp = 0;
                return (err);
        }

        /*
         * Common case of OK return with outval same as inval.
         */
        if (invalp != outvalp) {
                /* don't trust bcopy for identical src/dst */
                (void) bcopy(invalp, outvalp, inlen);
        }
        *outlenp = inlen;

        /*
         * If this was not ancillary data, then we rebuild the headers,
         * update the IRE/NCE, and IPsec as needed.
         * Since the label depends on the destination we go through
         * ip_set_destination first.
         */
        if (coa->coa_ancillary) {
                return (0);
        }

        if (coa->coa_changed & COA_ROUTE_CHANGED) {
                in6_addr_t saddr, faddr, nexthop;
                in_port_t fport;

                /*
                 * We clear lastdst to make sure we pick up the change
                 * next time sending.
                 * If we are connected we re-cache the information.
                 * We ignore errors to preserve BSD behavior.
                 * Note that we don't redo IPsec policy lookup here
                 * since the final destination (or source) didn't change.
                 */
                mutex_enter(&connp->conn_lock);
                connp->conn_v6lastdst = ipv6_all_zeros;

                ip_attr_nexthop(coa->coa_ipp, coa->coa_ixa,
                    &connp->conn_faddr_v6, &nexthop);
                saddr = connp->conn_saddr_v6;
                faddr = connp->conn_faddr_v6;
                fport = connp->conn_fport;
                mutex_exit(&connp->conn_lock);

                if (!IN6_IS_ADDR_UNSPECIFIED(&faddr) &&
                    !IN6_IS_ADDR_V4MAPPED_ANY(&faddr)) {
                        (void) ip_attr_connect(connp, coa->coa_ixa,
                            &saddr, &faddr, &nexthop, fport, NULL, NULL,
                            IPDF_ALLOW_MCBC | IPDF_VERIFY_DST);
                }
        }

        ixa_refrele(coa->coa_ixa);

        if (coa->coa_changed & COA_HEADER_CHANGED) {
                /*
                 * Rebuild the header template if we are connected.
                 * Otherwise clear conn_v6lastdst so we rebuild the header
                 * in the data path.
                 */
                mutex_enter(&connp->conn_lock);
                if (!IN6_IS_ADDR_UNSPECIFIED(&connp->conn_faddr_v6) &&
                    !IN6_IS_ADDR_V4MAPPED_ANY(&connp->conn_faddr_v6)) {
                        err = icmp_build_hdr_template(connp,
                            &connp->conn_saddr_v6, &connp->conn_faddr_v6,
                            connp->conn_flowinfo);
                        if (err != 0) {
                                mutex_exit(&connp->conn_lock);
                                return (err);
                        }
                } else {
                        connp->conn_v6lastdst = ipv6_all_zeros;
                }
                mutex_exit(&connp->conn_lock);
        }
        if (coa->coa_changed & COA_RCVBUF_CHANGED) {
                (void) proto_set_rx_hiwat(connp->conn_rq, connp,
                    connp->conn_rcvbuf);
        }
        if ((coa->coa_changed & COA_SNDBUF_CHANGED) && !IPCL_IS_NONSTR(connp)) {
                connp->conn_wq->q_hiwat = connp->conn_sndbuf;
        }
        if (coa->coa_changed & COA_WROFF_CHANGED) {
                /* Increase wroff if needed */
                uint_t wroff;

                mutex_enter(&connp->conn_lock);
                wroff = connp->conn_ht_iphc_allocated + is->is_wroff_extra;
                if (wroff > connp->conn_wroff) {
                        connp->conn_wroff = wroff;
                        mutex_exit(&connp->conn_lock);
                        (void) proto_set_tx_wroff(connp->conn_rq, connp, wroff);
                } else {
                        mutex_exit(&connp->conn_lock);
                }
        }
        if (coa->coa_changed & COA_ICMP_BIND_NEEDED) {
                icmp_bind_proto(icmp);
        }
        return (err);
}

/* This routine sets socket options. */
int
icmp_tpi_opt_set(queue_t *q, uint_t optset_context, int level, int name,
    uint_t inlen, uchar_t *invalp, uint_t *outlenp, uchar_t *outvalp,
    void *thisdg_attrs, cred_t *cr)
{
        conn_t  *connp = Q_TO_CONN(q);
        int error;

        error = icmp_opt_set(connp, optset_context, level, name, inlen, invalp,
            outlenp, outvalp, thisdg_attrs, cr);
        return (error);
}

/*
 * Setup IP headers.
 *
 * Note that IP_HDRINCL has ipha_protocol that is different than conn_proto,
 * but icmp_output_hdrincl restores ipha_protocol once we return.
 */
mblk_t *
icmp_prepend_hdr(conn_t *connp, ip_xmit_attr_t *ixa, const ip_pkt_t *ipp,
    const in6_addr_t *v6src, const in6_addr_t *v6dst, uint32_t flowinfo,
    mblk_t *data_mp, int *errorp)
{
        mblk_t          *mp;
        icmp_stack_t    *is = connp->conn_netstack->netstack_icmp;
        uint_t          data_len;
        uint32_t        cksum;

        data_len = msgdsize(data_mp);
        mp = conn_prepend_hdr(ixa, ipp, v6src, v6dst, connp->conn_proto,
            flowinfo, 0, data_mp, data_len, is->is_wroff_extra, &cksum, errorp);
        if (mp == NULL) {
                ASSERT(*errorp != 0);
                return (NULL);
        }

        ixa->ixa_pktlen = data_len + ixa->ixa_ip_hdr_length;

        /*
         * If there was a routing option/header then conn_prepend_hdr
         * has massaged it and placed the pseudo-header checksum difference
         * in the cksum argument.
         *
         * Prepare for ICMPv6 checksum done in IP.
         *
         * We make it easy for IP to include our pseudo header
         * by putting our length (and any routing header adjustment)
         * in the ICMPv6 checksum field.
         * The IP source, destination, and length have already been set by
         * conn_prepend_hdr.
         */
        cksum += data_len;
        cksum = (cksum >> 16) + (cksum & 0xFFFF);
        ASSERT(cksum < 0x10000);

        if (ixa->ixa_flags & IXAF_IS_IPV4) {
                ipha_t  *ipha = (ipha_t *)mp->b_rptr;

                ASSERT(ntohs(ipha->ipha_length) == ixa->ixa_pktlen);
        } else {
                ip6_t   *ip6h = (ip6_t *)mp->b_rptr;
                uint_t  cksum_offset = 0;

                ASSERT(ntohs(ip6h->ip6_plen) + IPV6_HDR_LEN == ixa->ixa_pktlen);

                if (ixa->ixa_flags & IXAF_SET_ULP_CKSUM) {
                        if (connp->conn_proto == IPPROTO_ICMPV6) {
                                cksum_offset = ixa->ixa_ip_hdr_length +
                                    offsetof(icmp6_t, icmp6_cksum);
                        } else if (ixa->ixa_flags & IXAF_SET_RAW_CKSUM) {
                                cksum_offset = ixa->ixa_ip_hdr_length +
                                    ixa->ixa_raw_cksum_offset;
                        }
                }
                if (cksum_offset != 0) {
                        uint16_t *ptr;

                        /* Make sure the checksum fits in the first mblk */
                        if (cksum_offset + sizeof (short) > MBLKL(mp)) {
                                mblk_t *mp1;

                                mp1 = msgpullup(mp,
                                    cksum_offset + sizeof (short));
                                freemsg(mp);
                                if (mp1 == NULL) {
                                        *errorp = ENOMEM;
                                        return (NULL);
                                }
                                mp = mp1;
                                ip6h = (ip6_t *)mp->b_rptr;
                        }
                        ptr = (uint16_t *)(mp->b_rptr + cksum_offset);
                        *ptr = htons(cksum);
                }
        }

        /* Note that we don't try to update wroff due to ancillary data */
        return (mp);
}

static int
icmp_build_hdr_template(conn_t *connp, const in6_addr_t *v6src,
    const in6_addr_t *v6dst, uint32_t flowinfo)
{
        int             error;

        ASSERT(MUTEX_HELD(&connp->conn_lock));
        /*
         * We clear lastdst to make sure we don't use the lastdst path
         * next time sending since we might not have set v6dst yet.
         */
        connp->conn_v6lastdst = ipv6_all_zeros;

        error = conn_build_hdr_template(connp, 0, 0, v6src, v6dst, flowinfo);
        if (error != 0)
                return (error);

        /*
         * Any routing header/option has been massaged. The checksum difference
         * is stored in conn_sum.
         */
        return (0);
}

static mblk_t *
icmp_queue_fallback(icmp_t *icmp, mblk_t *mp)
{
        ASSERT(MUTEX_HELD(&icmp->icmp_recv_lock));
        if (IPCL_IS_NONSTR(icmp->icmp_connp)) {
                /*
                 * fallback has started but messages have not been moved yet
                 */
                if (icmp->icmp_fallback_queue_head == NULL) {
                        ASSERT(icmp->icmp_fallback_queue_tail == NULL);
                        icmp->icmp_fallback_queue_head = mp;
                        icmp->icmp_fallback_queue_tail = mp;
                } else {
                        ASSERT(icmp->icmp_fallback_queue_tail != NULL);
                        icmp->icmp_fallback_queue_tail->b_next = mp;
                        icmp->icmp_fallback_queue_tail = mp;
                }
                return (NULL);
        } else {
                /*
                 * Fallback completed, let the caller putnext() the mblk.
                 */
                return (mp);
        }
}

/*
 * Deliver data to ULP. In case we have a socket, and it's falling back to
 * TPI, then we'll queue the mp for later processing.
 */
static void
icmp_ulp_recv(conn_t *connp, mblk_t *mp, uint_t len)
{
        if (IPCL_IS_NONSTR(connp)) {
                icmp_t *icmp = connp->conn_icmp;
                int error;

                ASSERT(len == msgdsize(mp));
                if ((*connp->conn_upcalls->su_recv)
                    (connp->conn_upper_handle, mp, len, 0, &error, NULL) < 0) {
                        mutex_enter(&icmp->icmp_recv_lock);
                        if (error == ENOSPC) {
                                /*
                                 * let's confirm while holding the lock
                                 */
                                if ((*connp->conn_upcalls->su_recv)
                                    (connp->conn_upper_handle, NULL, 0, 0,
                                    &error, NULL) < 0) {
                                        ASSERT(error == ENOSPC);
                                        if (error == ENOSPC) {
                                                connp->conn_flow_cntrld =
                                                    B_TRUE;
                                        }
                                }
                                mutex_exit(&icmp->icmp_recv_lock);
                        } else {
                                ASSERT(error == EOPNOTSUPP);
                                mp = icmp_queue_fallback(icmp, mp);
                                mutex_exit(&icmp->icmp_recv_lock);
                                if (mp != NULL)
                                        putnext(connp->conn_rq, mp);
                        }
                }
                ASSERT(MUTEX_NOT_HELD(&icmp->icmp_recv_lock));
        } else {
                putnext(connp->conn_rq, mp);
        }
}

/*
 * This is the inbound data path.
 * IP has already pulled up the IP headers and verified alignment
 * etc.
 */
/* ARGSUSED2 */
static void
icmp_input(void *arg1, mblk_t *mp, void *arg2, ip_recv_attr_t *ira)
{
        conn_t                  *connp = (conn_t *)arg1;
        struct T_unitdata_ind   *tudi;
        uchar_t                 *rptr;          /* Pointer to IP header */
        int                     ip_hdr_length;
        int                     udi_size;       /* Size of T_unitdata_ind */
        int                     pkt_len;
        icmp_t                  *icmp;
        ip_pkt_t                ipps;
        ip6_t                   *ip6h;
        mblk_t                  *mp1;
        crb_t                   recv_ancillary;
        icmp_stack_t            *is;
        sin_t                   *sin;
        sin6_t                  *sin6;
        ipha_t                  *ipha;

        ASSERT(connp->conn_flags & IPCL_RAWIPCONN);

        icmp = connp->conn_icmp;
        is = icmp->icmp_is;
        rptr = mp->b_rptr;

        ASSERT(DB_TYPE(mp) == M_DATA);
        ASSERT(OK_32PTR(rptr));
        ASSERT(ira->ira_pktlen == msgdsize(mp));
        pkt_len = ira->ira_pktlen;

        /*
         * Get a snapshot of these and allow other threads to change
         * them after that. We need the same recv_ancillary when determining
         * the size as when adding the ancillary data items.
         */
        mutex_enter(&connp->conn_lock);
        recv_ancillary = connp->conn_recv_ancillary;
        mutex_exit(&connp->conn_lock);

        ip_hdr_length = ira->ira_ip_hdr_length;
        ASSERT(MBLKL(mp) >= ip_hdr_length);     /* IP did a pullup */

        /* Initialize regardless of IP version */
        ipps.ipp_fields = 0;

        if (ira->ira_flags & IRAF_IS_IPV4) {
                ASSERT(IPH_HDR_VERSION(rptr) == IPV4_VERSION);
                ASSERT(MBLKL(mp) >= sizeof (ipha_t));
                ASSERT(ira->ira_ip_hdr_length == IPH_HDR_LENGTH(rptr));

                ipha = (ipha_t *)mp->b_rptr;
                if (recv_ancillary.crb_all != 0)
                        (void) ip_find_hdr_v4(ipha, &ipps, B_FALSE);

                /*
                 * BSD for some reason adjusts ipha_length to exclude the
                 * IP header length. We do the same.
                 */
                if (is->is_bsd_compat) {
                        ushort_t len;

                        len = ntohs(ipha->ipha_length);
                        if (mp->b_datap->db_ref > 1) {
                                /*
                                 * Allocate a new IP header so that we can
                                 * modify ipha_length.
                                 */
                                mblk_t  *mp1;

                                mp1 = allocb(ip_hdr_length, BPRI_MED);
                                if (mp1 == NULL) {
                                        freemsg(mp);
                                        BUMP_MIB(&is->is_rawip_mib,
                                            rawipInErrors);
                                        return;
                                }
                                bcopy(rptr, mp1->b_rptr, ip_hdr_length);
                                mp->b_rptr = rptr + ip_hdr_length;
                                rptr = mp1->b_rptr;
                                ipha = (ipha_t *)rptr;
                                mp1->b_cont = mp;
                                mp1->b_wptr = rptr + ip_hdr_length;
                                mp = mp1;
                        }
                        len -= ip_hdr_length;
                        ipha->ipha_length = htons(len);
                }

                /*
                 * For RAW sockets we not pass ICMP/IPv4 packets to AF_INET6
                 * sockets. This is ensured by icmp_bind and the IP fanout code.
                 */
                ASSERT(connp->conn_family == AF_INET);

                /*
                 * This is the inbound data path.  Packets are passed upstream
                 * as T_UNITDATA_IND messages with full IPv4 headers still
                 * attached.
                 */

                /*
                 * Normally only send up the source address.
                 * If any ancillary data items are wanted we add those.
                 */
                udi_size = sizeof (struct T_unitdata_ind) + sizeof (sin_t);
                if (recv_ancillary.crb_all != 0) {
                        udi_size += conn_recvancillary_size(connp,
                            recv_ancillary, ira, mp, &ipps);
                }

                /* Allocate a message block for the T_UNITDATA_IND structure. */
                mp1 = allocb(udi_size, BPRI_MED);
                if (mp1 == NULL) {
                        freemsg(mp);
                        BUMP_MIB(&is->is_rawip_mib, rawipInErrors);
                        return;
                }
                mp1->b_cont = mp;
                tudi = (struct T_unitdata_ind *)mp1->b_rptr;
                mp1->b_datap->db_type = M_PROTO;
                mp1->b_wptr = (uchar_t *)tudi + udi_size;
                tudi->PRIM_type = T_UNITDATA_IND;
                tudi->SRC_length = sizeof (sin_t);
                tudi->SRC_offset = sizeof (struct T_unitdata_ind);
                sin = (sin_t *)&tudi[1];
                *sin = sin_null;
                sin->sin_family = AF_INET;
                sin->sin_addr.s_addr = ipha->ipha_src;
                *(uint32_t *)&sin->sin_zero[0] = 0;
                *(uint32_t *)&sin->sin_zero[4] = 0;
                tudi->OPT_offset =  sizeof (struct T_unitdata_ind) +
                    sizeof (sin_t);
                udi_size -= (sizeof (struct T_unitdata_ind) + sizeof (sin_t));
                tudi->OPT_length = udi_size;

                /*
                 * Add options if IP_RECVIF etc is set
                 */
                if (udi_size != 0) {
                        conn_recvancillary_add(connp, recv_ancillary, ira,
                            &ipps, (uchar_t *)&sin[1], udi_size);
                }
                goto deliver;
        }

        ASSERT(IPH_HDR_VERSION(rptr) == IPV6_VERSION);
        /*
         * IPv6 packets can only be received by applications
         * that are prepared to receive IPv6 addresses.
         * The IP fanout must ensure this.
         */
        ASSERT(connp->conn_family == AF_INET6);

        /*
         * Handle IPv6 packets. We don't pass up the IP headers with the
         * payload for IPv6.
         */

        ip6h = (ip6_t *)rptr;
        if (recv_ancillary.crb_all != 0) {
                /*
                 * Call on ip_find_hdr_v6 which gets individual lenghts of
                 * extension headers (and pointers to them).
                 */
                uint8_t         nexthdr;

                /* We don't care about the length or nextheader. */
                (void) ip_find_hdr_v6(mp, ip6h, B_TRUE, &ipps, &nexthdr);

                /*
                 * We do not pass up hop-by-hop options or any other
                 * extension header as part of the packet. Applications
                 * that want to see them have to specify IPV6_RECV* socket
                 * options. And conn_recvancillary_size/add explicitly
                 * drops the TX option from IPV6_HOPOPTS as it does for UDP.
                 *
                 * If we had multilevel ICMP sockets, then we'd want to
                 * modify conn_recvancillary_size/add to
                 * allow the user to see the label.
                 */
        }

        /*
         * Check a filter for ICMPv6 types if needed.
         * Verify raw checksums if needed.
         */
        mutex_enter(&connp->conn_lock);
        if (icmp->icmp_filter != NULL) {
                int type;

                /* Assumes that IP has done the pullupmsg */
                type = mp->b_rptr[ip_hdr_length];

                ASSERT(mp->b_rptr + ip_hdr_length <= mp->b_wptr);
                if (ICMP6_FILTER_WILLBLOCK(type, icmp->icmp_filter)) {
                        mutex_exit(&connp->conn_lock);
                        freemsg(mp);
                        return;
                }
        }
        if (connp->conn_ixa->ixa_flags & IXAF_SET_RAW_CKSUM) {
                /* Checksum */
                uint16_t        *up;
                uint32_t        sum;
                int             remlen;

                up = (uint16_t *)&ip6h->ip6_src;

                remlen = msgdsize(mp) - ip_hdr_length;
                sum = htons(connp->conn_proto + remlen)
                    + up[0] + up[1] + up[2] + up[3]
                    + up[4] + up[5] + up[6] + up[7]
                    + up[8] + up[9] + up[10] + up[11]
                    + up[12] + up[13] + up[14] + up[15];
                sum = (sum & 0xffff) + (sum >> 16);
                sum = IP_CSUM(mp, ip_hdr_length, sum);
                if (sum != 0) {
                        /* IPv6 RAW checksum failed */
                        ip0dbg(("icmp_rput: RAW checksum failed %x\n", sum));
                        mutex_exit(&connp->conn_lock);
                        freemsg(mp);
                        BUMP_MIB(&is->is_rawip_mib, rawipInCksumErrs);
                        return;
                }
        }
        mutex_exit(&connp->conn_lock);

        udi_size = sizeof (struct T_unitdata_ind) + sizeof (sin6_t);

        if (recv_ancillary.crb_all != 0) {
                udi_size += conn_recvancillary_size(connp,
                    recv_ancillary, ira, mp, &ipps);
        }

        mp1 = allocb(udi_size, BPRI_MED);
        if (mp1 == NULL) {
                freemsg(mp);
                BUMP_MIB(&is->is_rawip_mib, rawipInErrors);
                return;
        }
        mp1->b_cont = mp;
        mp1->b_datap->db_type = M_PROTO;
        tudi = (struct T_unitdata_ind *)mp1->b_rptr;
        mp1->b_wptr = (uchar_t *)tudi + udi_size;
        tudi->PRIM_type = T_UNITDATA_IND;
        tudi->SRC_length = sizeof (sin6_t);
        tudi->SRC_offset = sizeof (struct T_unitdata_ind);
        tudi->OPT_offset = sizeof (struct T_unitdata_ind) + sizeof (sin6_t);
        udi_size -= (sizeof (struct T_unitdata_ind) + sizeof (sin6_t));
        tudi->OPT_length = udi_size;
        sin6 = (sin6_t *)&tudi[1];
        *sin6 = sin6_null;
        sin6->sin6_port = 0;
        sin6->sin6_family = AF_INET6;

        sin6->sin6_addr = ip6h->ip6_src;
        /* No sin6_flowinfo per API */
        sin6->sin6_flowinfo = 0;
        /* For link-scope pass up scope id */
        if (IN6_IS_ADDR_LINKSCOPE(&ip6h->ip6_src))
                sin6->sin6_scope_id = ira->ira_ruifindex;
        else
                sin6->sin6_scope_id = 0;
        sin6->__sin6_src_id = ip_srcid_find_addr(&ip6h->ip6_dst,
            IPCL_ZONEID(connp), is->is_netstack);

        if (udi_size != 0) {
                conn_recvancillary_add(connp, recv_ancillary, ira,
                    &ipps, (uchar_t *)&sin6[1], udi_size);
        }

        /* Skip all the IPv6 headers per API */
        mp->b_rptr += ip_hdr_length;
        pkt_len -= ip_hdr_length;

deliver:
        BUMP_MIB(&is->is_rawip_mib, rawipInDatagrams);
        icmp_ulp_recv(connp, mp1, pkt_len);
}

/*
 * return SNMP stuff in buffer in mpdata. We don't hold any lock and report
 * information that can be changing beneath us.
 */
mblk_t *
icmp_snmp_get(queue_t *q, mblk_t *mpctl)
{
        mblk_t                  *mpdata;
        struct opthdr           *optp;
        conn_t                  *connp = Q_TO_CONN(q);
        icmp_stack_t            *is = connp->conn_netstack->netstack_icmp;
        mblk_t                  *mp2ctl;

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

        if (mpctl == NULL ||
            (mpdata = mpctl->b_cont) == NULL) {
                freemsg(mpctl);
                freemsg(mp2ctl);
                return (0);
        }

        /* fixed length structure for IPv4 and IPv6 counters */
        optp = (struct opthdr *)&mpctl->b_rptr[sizeof (struct T_optmgmt_ack)];
        optp->level = EXPER_RAWIP;
        optp->name = 0;
        (void) snmp_append_data(mpdata, (char *)&is->is_rawip_mib,
            sizeof (is->is_rawip_mib));
        optp->len = msgdsize(mpdata);
        qreply(q, mpctl);

        return (mp2ctl);
}

/*
 * Return 0 if invalid set request, 1 otherwise, including non-rawip requests.
 * TODO:  If this ever actually tries to set anything, it needs to be
 * to do the appropriate locking.
 */
/* ARGSUSED */
int
icmp_snmp_set(queue_t *q, t_scalar_t level, t_scalar_t name,
    uchar_t *ptr, int len)
{
        switch (level) {
        case EXPER_RAWIP:
                return (0);
        default:
                return (1);
        }
}

/*
 * This routine creates a T_UDERROR_IND message and passes it upstream.
 * The address and options are copied from the T_UNITDATA_REQ message
 * passed in mp.  This message is freed.
 */
static void
icmp_ud_err(queue_t *q, mblk_t *mp, t_scalar_t err)
{
        struct T_unitdata_req *tudr;
        mblk_t  *mp1;
        uchar_t *destaddr;
        t_scalar_t destlen;
        uchar_t *optaddr;
        t_scalar_t optlen;

        if ((mp->b_wptr < mp->b_rptr) ||
            (MBLKL(mp)) < sizeof (struct T_unitdata_req)) {
                goto done;
        }
        tudr = (struct T_unitdata_req *)mp->b_rptr;
        destaddr = mp->b_rptr + tudr->DEST_offset;
        if (destaddr < mp->b_rptr || destaddr >= mp->b_wptr ||
            destaddr + tudr->DEST_length < mp->b_rptr ||
            destaddr + tudr->DEST_length > mp->b_wptr) {
                goto done;
        }
        optaddr = mp->b_rptr + tudr->OPT_offset;
        if (optaddr < mp->b_rptr || optaddr >= mp->b_wptr ||
            optaddr + tudr->OPT_length < mp->b_rptr ||
            optaddr + tudr->OPT_length > mp->b_wptr) {
                goto done;
        }
        destlen = tudr->DEST_length;
        optlen = tudr->OPT_length;

        mp1 = mi_tpi_uderror_ind((char *)destaddr, destlen,
            (char *)optaddr, optlen, err);
        if (mp1 != NULL)
                qreply(q, mp1);

done:
        freemsg(mp);
}

static int
rawip_do_unbind(conn_t *connp)
{
        icmp_t  *icmp = connp->conn_icmp;

        mutex_enter(&connp->conn_lock);
        /* If a bind has not been done, we can't unbind. */
        if (icmp->icmp_state == TS_UNBND) {
                mutex_exit(&connp->conn_lock);
                return (-TOUTSTATE);
        }
        connp->conn_saddr_v6 = ipv6_all_zeros;
        connp->conn_bound_addr_v6 = ipv6_all_zeros;
        connp->conn_laddr_v6 = ipv6_all_zeros;
        connp->conn_mcbc_bind = B_FALSE;
        connp->conn_lport = 0;
        connp->conn_fport = 0;
        /* In case we were also connected */
        connp->conn_faddr_v6 = ipv6_all_zeros;
        connp->conn_v6lastdst = ipv6_all_zeros;

        icmp->icmp_state = TS_UNBND;

        (void) icmp_build_hdr_template(connp, &connp->conn_saddr_v6,
            &connp->conn_faddr_v6, connp->conn_flowinfo);
        mutex_exit(&connp->conn_lock);

        ip_unbind(connp);
        return (0);
}

/*
 * This routine is called by icmp_wput to handle T_UNBIND_REQ messages.
 * After some error checking, the message is passed downstream to ip.
 */
static void
icmp_tpi_unbind(queue_t *q, mblk_t *mp)
{
        conn_t  *connp = Q_TO_CONN(q);
        int     error;

        ASSERT(mp->b_cont == NULL);
        error = rawip_do_unbind(connp);
        if (error) {
                if (error < 0) {
                        icmp_err_ack(q, mp, -error, 0);
                } else {
                        icmp_err_ack(q, mp, 0, error);
                }
                return;
        }

        /*
         * Convert mp into a T_OK_ACK
         */

        mp = mi_tpi_ok_ack_alloc(mp);

        /*
         * should not happen in practice... T_OK_ACK is smaller than the
         * original message.
         */
        ASSERT(mp != NULL);
        ASSERT(((struct T_ok_ack *)mp->b_rptr)->PRIM_type == T_OK_ACK);
        qreply(q, mp);
}

/*
 * Process IPv4 packets that already include an IP header.
 * Used when IP_HDRINCL has been set (implicit for IPPROTO_RAW and
 * IPPROTO_IGMP).
 * In this case we ignore the address and any options in the T_UNITDATA_REQ.
 *
 * The packet is assumed to have a base (20 byte) IP header followed
 * by the upper-layer protocol. We include any IP_OPTIONS including a
 * CIPSO label but otherwise preserve the base IP header.
 */
static int
icmp_output_hdrincl(conn_t *connp, mblk_t *mp, cred_t *cr, pid_t pid)
{
        icmp_t          *icmp = connp->conn_icmp;
        icmp_stack_t    *is = icmp->icmp_is;
        ipha_t          iphas;
        ipha_t          *ipha;
        int             ip_hdr_length;
        int             tp_hdr_len;
        ip_xmit_attr_t  *ixa;
        ip_pkt_t        *ipp;
        in6_addr_t      v6src;
        in6_addr_t      v6dst;
        in6_addr_t      v6nexthop;
        int             error;
        boolean_t       do_ipsec;

        /*
         * We need an exclusive copy of conn_ixa since the included IP
         * header could have any destination.
         * That copy has no pointers hence we
         * need to set them up once we've parsed the ancillary data.
         */
        ixa = conn_get_ixa_exclusive(connp);
        if (ixa == NULL) {
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                freemsg(mp);
                return (ENOMEM);
        }
        ASSERT(cr != NULL);
        /*
         * Caller has a reference on cr; from db_credp or because we
         * are running in process context.
         */
        ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
        ixa->ixa_cred = cr;
        ixa->ixa_cpid = pid;
        if (is_system_labeled()) {
                /* We need to restart with a label based on the cred */
                ip_xmit_attr_restore_tsl(ixa, ixa->ixa_cred);
        }

        /* In case previous destination was multicast or multirt */
        ip_attr_newdst(ixa);

        /* Get a copy of conn_xmit_ipp since the TX label might change it */
        ipp = kmem_zalloc(sizeof (*ipp), KM_NOSLEEP);
        if (ipp == NULL) {
                ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
                ixa->ixa_cred = connp->conn_cred;       /* Restore */
                ixa->ixa_cpid = connp->conn_cpid;
                ixa_refrele(ixa);
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                freemsg(mp);
                return (ENOMEM);
        }
        mutex_enter(&connp->conn_lock);
        error = ip_pkt_copy(&connp->conn_xmit_ipp, ipp, KM_NOSLEEP);
        mutex_exit(&connp->conn_lock);
        if (error != 0) {
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                freemsg(mp);
                goto done;
        }

        /* Sanity check length of packet */
        ipha = (ipha_t *)mp->b_rptr;

        ip_hdr_length = IP_SIMPLE_HDR_LENGTH;
        if ((mp->b_wptr - mp->b_rptr) < IP_SIMPLE_HDR_LENGTH) {
                if (!pullupmsg(mp, IP_SIMPLE_HDR_LENGTH)) {
                        BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                        freemsg(mp);
                        goto done;
                }
                ipha = (ipha_t *)mp->b_rptr;
        }
        ipha->ipha_version_and_hdr_length =
            (IP_VERSION<<4) | (ip_hdr_length>>2);

        /*
         * We set IXAF_DONTFRAG if the application set DF which makes
         * IP not fragment.
         */
        ipha->ipha_fragment_offset_and_flags &= htons(IPH_DF);
        if (ipha->ipha_fragment_offset_and_flags & htons(IPH_DF))
                ixa->ixa_flags |= (IXAF_DONTFRAG | IXAF_PMTU_IPV4_DF);
        else
                ixa->ixa_flags &= ~(IXAF_DONTFRAG | IXAF_PMTU_IPV4_DF);

        /* Even for multicast and broadcast we honor the apps ttl */
        ixa->ixa_flags |= IXAF_NO_TTL_CHANGE;

        /*
         * No source verification for non-local addresses
         */
        if (ipha->ipha_src != INADDR_ANY &&
            ip_laddr_verify_v4(ipha->ipha_src, ixa->ixa_zoneid,
            is->is_netstack->netstack_ip, B_FALSE)
            != IPVL_UNICAST_UP) {
                ixa->ixa_flags &= ~IXAF_VERIFY_SOURCE;
        }

        if (ipha->ipha_dst == INADDR_ANY)
                ipha->ipha_dst = htonl(INADDR_LOOPBACK);

        IN6_IPADDR_TO_V4MAPPED(ipha->ipha_src, &v6src);
        IN6_IPADDR_TO_V4MAPPED(ipha->ipha_dst, &v6dst);

        /* Defer IPsec if it might need to look at ICMP type/code */
        do_ipsec = ipha->ipha_protocol != IPPROTO_ICMP;
        ixa->ixa_flags |= IXAF_IS_IPV4;

        ip_attr_nexthop(ipp, ixa, &v6dst, &v6nexthop);
        error = ip_attr_connect(connp, ixa, &v6src, &v6dst, &v6nexthop,
            connp->conn_fport, &v6src, NULL, IPDF_ALLOW_MCBC | IPDF_VERIFY_DST |
            (do_ipsec ? IPDF_IPSEC : 0));
        switch (error) {
        case 0:
                break;
        case EADDRNOTAVAIL:
                /*
                 * IXAF_VERIFY_SOURCE tells us to pick a better source.
                 * Don't have the application see that errno
                 */
                error = ENETUNREACH;
                goto failed;
        case ENETDOWN:
                /*
                 * Have !ipif_addr_ready address; drop packet silently
                 * until we can get applications to not send until we
                 * are ready.
                 */
                error = 0;
                goto failed;
        case EHOSTUNREACH:
        case ENETUNREACH:
                if (ixa->ixa_ire != NULL) {
                        /*
                         * Let conn_ip_output/ire_send_noroute return
                         * the error and send any local ICMP error.
                         */
                        error = 0;
                        break;
                }
                /* FALLTHRU */
        default:
        failed:
                freemsg(mp);
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                goto done;
        }
        if (ipha->ipha_src == INADDR_ANY)
                IN6_V4MAPPED_TO_IPADDR(&v6src, ipha->ipha_src);

        /*
         * We might be going to a different destination than last time,
         * thus check that TX allows the communication and compute any
         * needed label.
         *
         * TSOL Note: We have an exclusive ipp and ixa for this thread so we
         * don't have to worry about concurrent threads.
         */
        if (is_system_labeled()) {
                /*
                 * Check whether Trusted Solaris policy allows communication
                 * with this host, and pretend that the destination is
                 * unreachable if not.
                 * Compute any needed label and place it in ipp_label_v4/v6.
                 *
                 * Later conn_build_hdr_template/conn_prepend_hdr takes
                 * ipp_label_v4/v6 to form the packet.
                 *
                 * Tsol note: We have ipp structure local to this thread so
                 * no locking is needed.
                 */
                error = conn_update_label(connp, ixa, &v6dst, ipp);
                if (error != 0) {
                        freemsg(mp);
                        BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                        goto done;
                }
        }

        /*
         * Save away a copy of the IPv4 header the application passed down
         * and then prepend an IPv4 header complete with any IP options
         * including label.
         * We need a struct copy since icmp_prepend_hdr will reuse the available
         * space in the mblk.
         */
        iphas = *ipha;
        mp->b_rptr += IP_SIMPLE_HDR_LENGTH;

        mp = icmp_prepend_hdr(connp, ixa, ipp, &v6src, &v6dst, 0, mp, &error);
        if (mp == NULL) {
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                ASSERT(error != 0);
                goto done;
        }
        if (ixa->ixa_pktlen > IP_MAXPACKET) {
                error = EMSGSIZE;
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                freemsg(mp);
                goto done;
        }
        /* Restore key parts of the header that the application passed down */
        ipha = (ipha_t *)mp->b_rptr;
        ipha->ipha_type_of_service = iphas.ipha_type_of_service;
        ipha->ipha_ident = iphas.ipha_ident;
        ipha->ipha_fragment_offset_and_flags =
            iphas.ipha_fragment_offset_and_flags;
        ipha->ipha_ttl = iphas.ipha_ttl;
        ipha->ipha_protocol = iphas.ipha_protocol;
        ipha->ipha_src = iphas.ipha_src;
        ipha->ipha_dst = iphas.ipha_dst;

        ixa->ixa_protocol = ipha->ipha_protocol;

        /*
         * Make sure that the IP header plus any transport header that is
         * checksumed by ip_output is in the first mblk. (ip_output assumes
         * that at least the checksum field is in the first mblk.)
         */
        switch (ipha->ipha_protocol) {
        case IPPROTO_UDP:
                tp_hdr_len = 8;
                break;
        case IPPROTO_TCP:
                tp_hdr_len = 20;
                break;
        default:
                tp_hdr_len = 0;
                break;
        }
        ip_hdr_length = IPH_HDR_LENGTH(ipha);
        if (mp->b_wptr - mp->b_rptr < ip_hdr_length + tp_hdr_len) {
                if (!pullupmsg(mp, ip_hdr_length + tp_hdr_len)) {
                        BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                        if (mp->b_cont == NULL)
                                error = EINVAL;
                        else
                                error = ENOMEM;
                        freemsg(mp);
                        goto done;
                }
        }

        if (!do_ipsec) {
                /* Policy might differ for different ICMP type/code */
                if (ixa->ixa_ipsec_policy != NULL) {
                        IPPOL_REFRELE(ixa->ixa_ipsec_policy);
                        ixa->ixa_ipsec_policy = NULL;
                        ixa->ixa_flags &= ~IXAF_IPSEC_SECURE;
                }
                mp = ip_output_attach_policy(mp, ipha, NULL, connp, ixa);
                if (mp == NULL) {
                        BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                        error = EHOSTUNREACH;   /* IPsec policy failure */
                        goto done;
                }
        }

        /* We're done.  Pass the packet to ip. */
        BUMP_MIB(&is->is_rawip_mib, rawipOutDatagrams);

        error = conn_ip_output(mp, ixa);
        /* No rawipOutErrors if an error since IP increases its error counter */
        switch (error) {
        case 0:
                break;
        case EWOULDBLOCK:
                (void) ixa_check_drain_insert(connp, ixa);
                error = 0;
                break;
        case EADDRNOTAVAIL:
                /*
                 * IXAF_VERIFY_SOURCE tells us to pick a better source.
                 * Don't have the application see that errno
                 */
                error = ENETUNREACH;
                break;
        }
done:
        ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
        ixa->ixa_cred = connp->conn_cred;       /* Restore */
        ixa->ixa_cpid = connp->conn_cpid;
        ixa_refrele(ixa);
        ip_pkt_free(ipp);
        kmem_free(ipp, sizeof (*ipp));
        return (error);
}

static mblk_t *
icmp_output_attach_policy(mblk_t *mp, conn_t *connp, ip_xmit_attr_t *ixa)
{
        ipha_t  *ipha = NULL;
        ip6_t   *ip6h = NULL;

        if (ixa->ixa_flags & IXAF_IS_IPV4)
                ipha = (ipha_t *)mp->b_rptr;
        else
                ip6h = (ip6_t *)mp->b_rptr;

        if (ixa->ixa_ipsec_policy != NULL) {
                IPPOL_REFRELE(ixa->ixa_ipsec_policy);
                ixa->ixa_ipsec_policy = NULL;
                ixa->ixa_flags &= ~IXAF_IPSEC_SECURE;
        }
        return (ip_output_attach_policy(mp, ipha, ip6h, connp, ixa));
}

/*
 * Handle T_UNITDATA_REQ with options. Both IPv4 and IPv6
 * Either tudr_mp or msg is set. If tudr_mp we take ancillary data from
 * the TPI options, otherwise we take them from msg_control.
 * If both sin and sin6 is set it is a connected socket and we use conn_faddr.
 * Always consumes mp; never consumes tudr_mp.
 */
static int
icmp_output_ancillary(conn_t *connp, sin_t *sin, sin6_t *sin6, mblk_t *mp,
    mblk_t *tudr_mp, struct nmsghdr *msg, cred_t *cr, pid_t pid)
{
        icmp_t          *icmp = connp->conn_icmp;
        icmp_stack_t    *is = icmp->icmp_is;
        int             error;
        ip_xmit_attr_t  *ixa;
        ip_pkt_t        *ipp;
        in6_addr_t      v6src;
        in6_addr_t      v6dst;
        in6_addr_t      v6nexthop;
        in_port_t       dstport;
        uint32_t        flowinfo;
        int             is_absreq_failure = 0;
        conn_opt_arg_t  coas, *coa;

        ASSERT(tudr_mp != NULL || msg != NULL);

        /*
         * Get ixa before checking state to handle a disconnect race.
         *
         * We need an exclusive copy of conn_ixa since the ancillary data
         * options might modify it. That copy has no pointers hence we
         * need to set them up once we've parsed the ancillary data.
         */
        ixa = conn_get_ixa_exclusive(connp);
        if (ixa == NULL) {
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                freemsg(mp);
                return (ENOMEM);
        }
        ASSERT(cr != NULL);
        ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
        ixa->ixa_cred = cr;
        ixa->ixa_cpid = pid;
        if (is_system_labeled()) {
                /* We need to restart with a label based on the cred */
                ip_xmit_attr_restore_tsl(ixa, ixa->ixa_cred);
        }

        /* In case previous destination was multicast or multirt */
        ip_attr_newdst(ixa);

        /* Get a copy of conn_xmit_ipp since the options might change it */
        ipp = kmem_zalloc(sizeof (*ipp), KM_NOSLEEP);
        if (ipp == NULL) {
                ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
                ixa->ixa_cred = connp->conn_cred;       /* Restore */
                ixa->ixa_cpid = connp->conn_cpid;
                ixa_refrele(ixa);
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                freemsg(mp);
                return (ENOMEM);
        }
        mutex_enter(&connp->conn_lock);
        error = ip_pkt_copy(&connp->conn_xmit_ipp, ipp, KM_NOSLEEP);
        mutex_exit(&connp->conn_lock);
        if (error != 0) {
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                freemsg(mp);
                goto done;
        }

        /*
         * Parse the options and update ixa and ipp as a result.
         */

        coa = &coas;
        coa->coa_connp = connp;
        coa->coa_ixa = ixa;
        coa->coa_ipp = ipp;
        coa->coa_ancillary = B_TRUE;
        coa->coa_changed = 0;

        if (msg != NULL) {
                error = process_auxiliary_options(connp, msg->msg_control,
                    msg->msg_controllen, coa, &icmp_opt_obj, icmp_opt_set, cr);
        } else {
                struct T_unitdata_req *tudr;

                tudr = (struct T_unitdata_req *)tudr_mp->b_rptr;
                ASSERT(tudr->PRIM_type == T_UNITDATA_REQ);
                error = tpi_optcom_buf(connp->conn_wq, tudr_mp,
                    &tudr->OPT_length, tudr->OPT_offset, cr, &icmp_opt_obj,
                    coa, &is_absreq_failure);
        }
        if (error != 0) {
                /*
                 * Note: No special action needed in this
                 * module for "is_absreq_failure"
                 */
                freemsg(mp);
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                goto done;
        }
        ASSERT(is_absreq_failure == 0);

        mutex_enter(&connp->conn_lock);
        /*
         * If laddr is unspecified then we look at sin6_src_id.
         * We will give precedence to a source address set with IPV6_PKTINFO
         * (aka IPPF_ADDR) but that is handled in build_hdrs. However, we don't
         * want ip_attr_connect to select a source (since it can fail) when
         * IPV6_PKTINFO is specified.
         * If this doesn't result in a source address then we get a source
         * from ip_attr_connect() below.
         */
        v6src = connp->conn_saddr_v6;
        if (sin != NULL) {
                IN6_IPADDR_TO_V4MAPPED(sin->sin_addr.s_addr, &v6dst);
                dstport = sin->sin_port;
                flowinfo = 0;
                ixa->ixa_flags &= ~IXAF_SCOPEID_SET;
                ixa->ixa_flags |= IXAF_IS_IPV4;
        } else if (sin6 != NULL) {
                boolean_t v4mapped;
                uint_t srcid;

                v6dst = sin6->sin6_addr;
                dstport = sin6->sin6_port;
                flowinfo = sin6->sin6_flowinfo;
                srcid = sin6->__sin6_src_id;
                if (IN6_IS_ADDR_LINKSCOPE(&v6dst) && sin6->sin6_scope_id != 0) {
                        ixa->ixa_scopeid = sin6->sin6_scope_id;
                        ixa->ixa_flags |= IXAF_SCOPEID_SET;
                } else {
                        ixa->ixa_flags &= ~IXAF_SCOPEID_SET;
                }
                v4mapped = IN6_IS_ADDR_V4MAPPED(&v6dst);
                if (v4mapped)
                        ixa->ixa_flags |= IXAF_IS_IPV4;
                else
                        ixa->ixa_flags &= ~IXAF_IS_IPV4;
                if (srcid != 0 && IN6_IS_ADDR_UNSPECIFIED(&v6src)) {
                        if (!ip_srcid_find_id(srcid, &v6src, IPCL_ZONEID(connp),
                            v4mapped, connp->conn_netstack)) {
                                /* Mismatched v4mapped/v6 specified by srcid. */
                                mutex_exit(&connp->conn_lock);
                                error = EADDRNOTAVAIL;
                                goto failed;    /* Does freemsg() and mib. */
                        }
                }
        } else {
                /* Connected case */
                dstport = connp->conn_fport;
                v6dst = connp->conn_faddr_v6;
                flowinfo = connp->conn_flowinfo;
        }
        mutex_exit(&connp->conn_lock);
        /* Handle IP_PKTINFO/IPV6_PKTINFO setting source address. */
        if (ipp->ipp_fields & IPPF_ADDR) {
                if (ixa->ixa_flags & IXAF_IS_IPV4) {
                        if (IN6_IS_ADDR_V4MAPPED(&ipp->ipp_addr))
                                v6src = ipp->ipp_addr;
                } else {
                        if (!IN6_IS_ADDR_V4MAPPED(&ipp->ipp_addr))
                                v6src = ipp->ipp_addr;
                }
        }
        /*
         * Allow source not assigned to the system
         * only if it is not a local addresses
         */
        if (!V6_OR_V4_INADDR_ANY(v6src)) {
                ip_laddr_t laddr_type;

                if (ixa->ixa_flags & IXAF_IS_IPV4) {
                        ipaddr_t v4src;

                        IN6_V4MAPPED_TO_IPADDR(&v6src, v4src);
                        laddr_type = ip_laddr_verify_v4(v4src, ixa->ixa_zoneid,
                            is->is_netstack->netstack_ip, B_FALSE);
                } else {
                        laddr_type = ip_laddr_verify_v6(&v6src, ixa->ixa_zoneid,
                            is->is_netstack->netstack_ip, B_FALSE, B_FALSE);
                }
                if (laddr_type != IPVL_UNICAST_UP)
                        ixa->ixa_flags &= ~IXAF_VERIFY_SOURCE;
        }

        ip_attr_nexthop(ipp, ixa, &v6dst, &v6nexthop);
        error = ip_attr_connect(connp, ixa, &v6src, &v6dst, &v6nexthop, dstport,
            &v6src, NULL, IPDF_ALLOW_MCBC | IPDF_VERIFY_DST);

        switch (error) {
        case 0:
                break;
        case EADDRNOTAVAIL:
                /*
                 * IXAF_VERIFY_SOURCE tells us to pick a better source.
                 * Don't have the application see that errno
                 */
                error = ENETUNREACH;
                goto failed;
        case ENETDOWN:
                /*
                 * Have !ipif_addr_ready address; drop packet silently
                 * until we can get applications to not send until we
                 * are ready.
                 */
                error = 0;
                goto failed;
        case EHOSTUNREACH:
        case ENETUNREACH:
                if (ixa->ixa_ire != NULL) {
                        /*
                         * Let conn_ip_output/ire_send_noroute return
                         * the error and send any local ICMP error.
                         */
                        error = 0;
                        break;
                }
                /* FALLTHRU */
        default:
        failed:
                freemsg(mp);
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                goto done;
        }

        /*
         * We might be going to a different destination than last time,
         * thus check that TX allows the communication and compute any
         * needed label.
         *
         * TSOL Note: We have an exclusive ipp and ixa for this thread so we
         * don't have to worry about concurrent threads.
         */
        if (is_system_labeled()) {
                /*
                 * Check whether Trusted Solaris policy allows communication
                 * with this host, and pretend that the destination is
                 * unreachable if not.
                 * Compute any needed label and place it in ipp_label_v4/v6.
                 *
                 * Later conn_build_hdr_template/conn_prepend_hdr takes
                 * ipp_label_v4/v6 to form the packet.
                 *
                 * Tsol note: We have ipp structure local to this thread so
                 * no locking is needed.
                 */
                error = conn_update_label(connp, ixa, &v6dst, ipp);
                if (error != 0) {
                        freemsg(mp);
                        BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                        goto done;
                }
        }
        mp = icmp_prepend_hdr(connp, ixa, ipp, &v6src, &v6dst, flowinfo, mp,
            &error);
        if (mp == NULL) {
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                ASSERT(error != 0);
                goto done;
        }
        if (ixa->ixa_pktlen > IP_MAXPACKET) {
                error = EMSGSIZE;
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                freemsg(mp);
                goto done;
        }

        /* Policy might differ for different ICMP type/code */
        mp = icmp_output_attach_policy(mp, connp, ixa);
        if (mp == NULL) {
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                error = EHOSTUNREACH;   /* IPsec policy failure */
                goto done;
        }

        /* We're done.  Pass the packet to ip. */
        BUMP_MIB(&is->is_rawip_mib, rawipOutDatagrams);

        error = conn_ip_output(mp, ixa);
        if (!connp->conn_unspec_src)
                ixa->ixa_flags |= IXAF_VERIFY_SOURCE;
        /* No rawipOutErrors if an error since IP increases its error counter */
        switch (error) {
        case 0:
                break;
        case EWOULDBLOCK:
                (void) ixa_check_drain_insert(connp, ixa);
                error = 0;
                break;
        case EADDRNOTAVAIL:
                /*
                 * IXAF_VERIFY_SOURCE tells us to pick a better source.
                 * Don't have the application see that errno
                 */
                error = ENETUNREACH;
                /* FALLTHRU */
        default:
                mutex_enter(&connp->conn_lock);
                /*
                 * Clear the source and v6lastdst so we call ip_attr_connect
                 * for the next packet and try to pick a better source.
                 */
                if (connp->conn_mcbc_bind)
                        connp->conn_saddr_v6 = ipv6_all_zeros;
                else
                        connp->conn_saddr_v6 = connp->conn_bound_addr_v6;
                connp->conn_v6lastdst = ipv6_all_zeros;
                mutex_exit(&connp->conn_lock);
                break;
        }
done:
        ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
        ixa->ixa_cred = connp->conn_cred;       /* Restore */
        ixa->ixa_cpid = connp->conn_cpid;
        ixa_refrele(ixa);
        ip_pkt_free(ipp);
        kmem_free(ipp, sizeof (*ipp));
        return (error);
}

/*
 * Handle sending an M_DATA for a connected socket.
 * Handles both IPv4 and IPv6.
 */
int
icmp_output_connected(conn_t *connp, mblk_t *mp, cred_t *cr, pid_t pid)
{
        icmp_t          *icmp = connp->conn_icmp;
        icmp_stack_t    *is = icmp->icmp_is;
        int             error;
        ip_xmit_attr_t  *ixa;
        boolean_t       do_ipsec;

        /*
         * If no other thread is using conn_ixa this just gets a reference to
         * conn_ixa. Otherwise we get a safe copy of conn_ixa.
         */
        ixa = conn_get_ixa(connp, B_FALSE);
        if (ixa == NULL) {
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                freemsg(mp);
                return (ENOMEM);
        }

        ASSERT(cr != NULL);
        ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
        ixa->ixa_cred = cr;
        ixa->ixa_cpid = pid;

        /* Defer IPsec if it might need to look at ICMP type/code */
        switch (ixa->ixa_protocol) {
        case IPPROTO_ICMP:
        case IPPROTO_ICMPV6:
                do_ipsec = B_FALSE;
                break;
        default:
                do_ipsec = B_TRUE;
        }

        mutex_enter(&connp->conn_lock);
        mp = icmp_prepend_header_template(connp, ixa, mp,
            &connp->conn_saddr_v6, connp->conn_flowinfo, &error);

        if (mp == NULL) {
                ASSERT(error != 0);
                mutex_exit(&connp->conn_lock);
                ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
                ixa->ixa_cred = connp->conn_cred;       /* Restore */
                ixa->ixa_cpid = connp->conn_cpid;
                ixa_refrele(ixa);
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                freemsg(mp);
                return (error);
        }

        if (!do_ipsec) {
                /* Policy might differ for different ICMP type/code */
                mp = icmp_output_attach_policy(mp, connp, ixa);
                if (mp == NULL) {
                        mutex_exit(&connp->conn_lock);
                        BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                        ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
                        ixa->ixa_cred = connp->conn_cred;       /* Restore */
                        ixa->ixa_cpid = connp->conn_cpid;
                        ixa_refrele(ixa);
                        return (EHOSTUNREACH);  /* IPsec policy failure */
                }
        }

        /*
         * In case we got a safe copy of conn_ixa, or if opt_set made us a new
         * safe copy, then we need to fill in any pointers in it.
         */
        if (ixa->ixa_ire == NULL) {
                in6_addr_t      faddr, saddr;
                in6_addr_t      nexthop;
                in_port_t       fport;

                saddr = connp->conn_saddr_v6;
                faddr = connp->conn_faddr_v6;
                fport = connp->conn_fport;
                ip_attr_nexthop(&connp->conn_xmit_ipp, ixa, &faddr, &nexthop);
                mutex_exit(&connp->conn_lock);

                error = ip_attr_connect(connp, ixa, &saddr, &faddr, &nexthop,
                    fport, NULL, NULL, IPDF_ALLOW_MCBC | IPDF_VERIFY_DST |
                    (do_ipsec ? IPDF_IPSEC : 0));
                switch (error) {
                case 0:
                        break;
                case EADDRNOTAVAIL:
                        /*
                         * IXAF_VERIFY_SOURCE tells us to pick a better source.
                         * Don't have the application see that errno
                         */
                        error = ENETUNREACH;
                        goto failed;
                case ENETDOWN:
                        /*
                         * Have !ipif_addr_ready address; drop packet silently
                         * until we can get applications to not send until we
                         * are ready.
                         */
                        error = 0;
                        goto failed;
                case EHOSTUNREACH:
                case ENETUNREACH:
                        if (ixa->ixa_ire != NULL) {
                                /*
                                 * Let conn_ip_output/ire_send_noroute return
                                 * the error and send any local ICMP error.
                                 */
                                error = 0;
                                break;
                        }
                        /* FALLTHRU */
                default:
                failed:
                        ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
                        ixa->ixa_cred = connp->conn_cred;       /* Restore */
                        ixa->ixa_cpid = connp->conn_cpid;
                        ixa_refrele(ixa);
                        BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                        freemsg(mp);
                        return (error);
                }
        } else {
                /* Done with conn_t */
                mutex_exit(&connp->conn_lock);
        }

        /* We're done.  Pass the packet to ip. */
        BUMP_MIB(&is->is_rawip_mib, rawipOutDatagrams);

        error = conn_ip_output(mp, ixa);
        /* No rawipOutErrors if an error since IP increases its error counter */
        switch (error) {
        case 0:
                break;
        case EWOULDBLOCK:
                (void) ixa_check_drain_insert(connp, ixa);
                error = 0;
                break;
        case EADDRNOTAVAIL:
                /*
                 * IXAF_VERIFY_SOURCE tells us to pick a better source.
                 * Don't have the application see that errno
                 */
                error = ENETUNREACH;
                break;
        }
        ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
        ixa->ixa_cred = connp->conn_cred;       /* Restore */
        ixa->ixa_cpid = connp->conn_cpid;
        ixa_refrele(ixa);
        return (error);
}

/*
 * Handle sending an M_DATA to the last destination.
 * Handles both IPv4 and IPv6.
 *
 * NOTE: The caller must hold conn_lock and we drop it here.
 */
int
icmp_output_lastdst(conn_t *connp, mblk_t *mp, cred_t *cr, pid_t pid,
    ip_xmit_attr_t *ixa)
{
        icmp_t          *icmp = connp->conn_icmp;
        icmp_stack_t    *is = icmp->icmp_is;
        int             error;
        boolean_t       do_ipsec;

        ASSERT(MUTEX_HELD(&connp->conn_lock));
        ASSERT(ixa != NULL);

        ASSERT(cr != NULL);
        ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
        ixa->ixa_cred = cr;
        ixa->ixa_cpid = pid;

        /* Defer IPsec if it might need to look at ICMP type/code */
        switch (ixa->ixa_protocol) {
        case IPPROTO_ICMP:
        case IPPROTO_ICMPV6:
                do_ipsec = B_FALSE;
                break;
        default:
                do_ipsec = B_TRUE;
        }


        mp = icmp_prepend_header_template(connp, ixa, mp,
            &connp->conn_v6lastsrc, connp->conn_lastflowinfo, &error);

        if (mp == NULL) {
                ASSERT(error != 0);
                mutex_exit(&connp->conn_lock);
                ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
                ixa->ixa_cred = connp->conn_cred;       /* Restore */
                ixa->ixa_cpid = connp->conn_cpid;
                ixa_refrele(ixa);
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                freemsg(mp);
                return (error);
        }

        if (!do_ipsec) {
                /* Policy might differ for different ICMP type/code */
                mp = icmp_output_attach_policy(mp, connp, ixa);
                if (mp == NULL) {
                        mutex_exit(&connp->conn_lock);
                        BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                        ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
                        ixa->ixa_cred = connp->conn_cred;       /* Restore */
                        ixa->ixa_cpid = connp->conn_cpid;
                        ixa_refrele(ixa);
                        return (EHOSTUNREACH);  /* IPsec policy failure */
                }
        }

        /*
         * In case we got a safe copy of conn_ixa, or if opt_set made us a new
         * safe copy, then we need to fill in any pointers in it.
         */
        if (ixa->ixa_ire == NULL) {
                in6_addr_t      lastdst, lastsrc;
                in6_addr_t      nexthop;
                in_port_t       lastport;

                lastsrc = connp->conn_v6lastsrc;
                lastdst = connp->conn_v6lastdst;
                lastport = connp->conn_lastdstport;
                ip_attr_nexthop(&connp->conn_xmit_ipp, ixa, &lastdst, &nexthop);
                mutex_exit(&connp->conn_lock);

                error = ip_attr_connect(connp, ixa, &lastsrc, &lastdst,
                    &nexthop, lastport, NULL, NULL, IPDF_ALLOW_MCBC |
                    IPDF_VERIFY_DST | (do_ipsec ? IPDF_IPSEC : 0));
                switch (error) {
                case 0:
                        break;
                case EADDRNOTAVAIL:
                        /*
                         * IXAF_VERIFY_SOURCE tells us to pick a better source.
                         * Don't have the application see that errno
                         */
                        error = ENETUNREACH;
                        goto failed;
                case ENETDOWN:
                        /*
                         * Have !ipif_addr_ready address; drop packet silently
                         * until we can get applications to not send until we
                         * are ready.
                         */
                        error = 0;
                        goto failed;
                case EHOSTUNREACH:
                case ENETUNREACH:
                        if (ixa->ixa_ire != NULL) {
                                /*
                                 * Let conn_ip_output/ire_send_noroute return
                                 * the error and send any local ICMP error.
                                 */
                                error = 0;
                                break;
                        }
                        /* FALLTHRU */
                default:
                failed:
                        ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
                        ixa->ixa_cred = connp->conn_cred;       /* Restore */
                        ixa->ixa_cpid = connp->conn_cpid;
                        ixa_refrele(ixa);
                        BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                        freemsg(mp);
                        return (error);
                }
        } else {
                /* Done with conn_t */
                mutex_exit(&connp->conn_lock);
        }

        /* We're done.  Pass the packet to ip. */
        BUMP_MIB(&is->is_rawip_mib, rawipOutDatagrams);
        error = conn_ip_output(mp, ixa);
        /* No rawipOutErrors if an error since IP increases its error counter */
        switch (error) {
        case 0:
                break;
        case EWOULDBLOCK:
                (void) ixa_check_drain_insert(connp, ixa);
                error = 0;
                break;
        case EADDRNOTAVAIL:
                /*
                 * IXAF_VERIFY_SOURCE tells us to pick a better source.
                 * Don't have the application see that errno
                 */
                error = ENETUNREACH;
                /* FALLTHRU */
        default:
                mutex_enter(&connp->conn_lock);
                /*
                 * Clear the source and v6lastdst so we call ip_attr_connect
                 * for the next packet and try to pick a better source.
                 */
                if (connp->conn_mcbc_bind)
                        connp->conn_saddr_v6 = ipv6_all_zeros;
                else
                        connp->conn_saddr_v6 = connp->conn_bound_addr_v6;
                connp->conn_v6lastdst = ipv6_all_zeros;
                mutex_exit(&connp->conn_lock);
                break;
        }
        ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
        ixa->ixa_cred = connp->conn_cred;       /* Restore */
        ixa->ixa_cpid = connp->conn_cpid;
        ixa_refrele(ixa);
        return (error);
}


/*
 * Prepend the header template and then fill in the source and
 * flowinfo. The caller needs to handle the destination address since
 * it's setting is different if rthdr or source route.
 *
 * Returns NULL is allocation failed or if the packet would exceed IP_MAXPACKET.
 * When it returns NULL it sets errorp.
 */
static mblk_t *
icmp_prepend_header_template(conn_t *connp, ip_xmit_attr_t *ixa, mblk_t *mp,
    const in6_addr_t *v6src, uint32_t flowinfo, int *errorp)
{
        icmp_t          *icmp = connp->conn_icmp;
        icmp_stack_t    *is = icmp->icmp_is;
        uint_t          pktlen;
        uint_t          copylen;
        uint8_t         *iph;
        uint_t          ip_hdr_length;
        uint32_t        cksum;
        ip_pkt_t        *ipp;

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

        /*
         * Copy the header template.
         */
        copylen = connp->conn_ht_iphc_len;
        pktlen = copylen + msgdsize(mp);
        if (pktlen > IP_MAXPACKET) {
                freemsg(mp);
                *errorp = EMSGSIZE;
                return (NULL);
        }
        ixa->ixa_pktlen = pktlen;

        /* check/fix buffer config, setup pointers into it */
        iph = mp->b_rptr - copylen;
        if (DB_REF(mp) != 1 || iph < DB_BASE(mp) || !OK_32PTR(iph)) {
                mblk_t *mp1;

                mp1 = allocb(copylen + is->is_wroff_extra, BPRI_MED);
                if (mp1 == NULL) {
                        freemsg(mp);
                        *errorp = ENOMEM;
                        return (NULL);
                }
                mp1->b_wptr = DB_LIM(mp1);
                mp1->b_cont = mp;
                mp = mp1;
                iph = (mp->b_wptr - copylen);
        }
        mp->b_rptr = iph;
        bcopy(connp->conn_ht_iphc, iph, copylen);
        ip_hdr_length = (uint_t)(connp->conn_ht_ulp - connp->conn_ht_iphc);

        ixa->ixa_ip_hdr_length = ip_hdr_length;

        /*
         * Prepare for ICMPv6 checksum done in IP.
         *
         * icmp_build_hdr_template has already massaged any routing header
         * and placed the result in conn_sum.
         *
         * We make it easy for IP to include our pseudo header
         * by putting our length (and any routing header adjustment)
         * in the ICMPv6 checksum field.
         */
        cksum = pktlen - ip_hdr_length;

        cksum += connp->conn_sum;
        cksum = (cksum >> 16) + (cksum & 0xFFFF);
        ASSERT(cksum < 0x10000);

        ipp = &connp->conn_xmit_ipp;
        if (ixa->ixa_flags & IXAF_IS_IPV4) {
                ipha_t  *ipha = (ipha_t *)iph;

                ipha->ipha_length = htons((uint16_t)pktlen);

                /* if IP_PKTINFO specified an addres it wins over bind() */
                if ((ipp->ipp_fields & IPPF_ADDR) &&
                    IN6_IS_ADDR_V4MAPPED(&ipp->ipp_addr)) {
                        ASSERT(ipp->ipp_addr_v4 != INADDR_ANY);
                        ipha->ipha_src = ipp->ipp_addr_v4;
                } else {
                        IN6_V4MAPPED_TO_IPADDR(v6src, ipha->ipha_src);
                }
        } else {
                ip6_t *ip6h = (ip6_t *)iph;
                uint_t  cksum_offset = 0;

                ip6h->ip6_plen =  htons((uint16_t)(pktlen - IPV6_HDR_LEN));

                /* if IP_PKTINFO specified an addres it wins over bind() */
                if ((ipp->ipp_fields & IPPF_ADDR) &&
                    !IN6_IS_ADDR_V4MAPPED(&ipp->ipp_addr)) {
                        ASSERT(!IN6_IS_ADDR_UNSPECIFIED(&ipp->ipp_addr));
                        ip6h->ip6_src = ipp->ipp_addr;
                } else {
                        ip6h->ip6_src = *v6src;
                }
                ip6h->ip6_vcf =
                    (IPV6_DEFAULT_VERS_AND_FLOW & IPV6_VERS_AND_FLOW_MASK) |
                    (flowinfo & ~IPV6_VERS_AND_FLOW_MASK);
                if (ipp->ipp_fields & IPPF_TCLASS) {
                        /* Overrides the class part of flowinfo */
                        ip6h->ip6_vcf = IPV6_TCLASS_FLOW(ip6h->ip6_vcf,
                            ipp->ipp_tclass);
                }

                if (ixa->ixa_flags & IXAF_SET_ULP_CKSUM) {
                        if (connp->conn_proto == IPPROTO_ICMPV6) {
                                cksum_offset = ixa->ixa_ip_hdr_length +
                                    offsetof(icmp6_t, icmp6_cksum);
                        } else if (ixa->ixa_flags & IXAF_SET_RAW_CKSUM) {
                                cksum_offset = ixa->ixa_ip_hdr_length +
                                    ixa->ixa_raw_cksum_offset;
                        }
                }
                if (cksum_offset != 0) {
                        uint16_t *ptr;

                        /* Make sure the checksum fits in the first mblk */
                        if (cksum_offset + sizeof (short) > MBLKL(mp)) {
                                mblk_t *mp1;

                                mp1 = msgpullup(mp,
                                    cksum_offset + sizeof (short));
                                freemsg(mp);
                                if (mp1 == NULL) {
                                        *errorp = ENOMEM;
                                        return (NULL);
                                }
                                mp = mp1;
                                iph = mp->b_rptr;
                                ip6h = (ip6_t *)iph;
                        }
                        ptr = (uint16_t *)(mp->b_rptr + cksum_offset);
                        *ptr = htons(cksum);
                }
        }

        return (mp);
}

/*
 * This routine handles all messages passed downstream.  It either
 * consumes the message or passes it downstream; it never queues a
 * a message.
 */
int
icmp_wput(queue_t *q, mblk_t *mp)
{
        sin6_t          *sin6;
        sin_t           *sin = NULL;
        uint_t          srcid;
        conn_t          *connp = Q_TO_CONN(q);
        icmp_t          *icmp = connp->conn_icmp;
        int             error = 0;
        struct sockaddr *addr = NULL;
        socklen_t       addrlen;
        icmp_stack_t    *is = icmp->icmp_is;
        struct T_unitdata_req *tudr;
        mblk_t          *data_mp;
        cred_t          *cr;
        pid_t           pid;

        /*
         * We directly handle several cases here: T_UNITDATA_REQ message
         * coming down as M_PROTO/M_PCPROTO and M_DATA messages for connected
         * socket.
         */
        switch (DB_TYPE(mp)) {
        case M_DATA:
                /* sockfs never sends down M_DATA */
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                freemsg(mp);
                return (0);

        case M_PROTO:
        case M_PCPROTO:
                tudr = (struct T_unitdata_req *)mp->b_rptr;
                if (MBLKL(mp) < sizeof (*tudr) ||
                    ((t_primp_t)mp->b_rptr)->type != T_UNITDATA_REQ) {
                        icmp_wput_other(q, mp);
                        return (0);
                }
                break;

        default:
                icmp_wput_other(q, mp);
                return (0);
        }

        /* Handle valid T_UNITDATA_REQ here */
        data_mp = mp->b_cont;
        if (data_mp == NULL) {
                error = EPROTO;
                goto ud_error2;
        }
        mp->b_cont = NULL;

        if (!MBLKIN(mp, 0, tudr->DEST_offset + tudr->DEST_length)) {
                error = EADDRNOTAVAIL;
                goto ud_error2;
        }

        /*
         * All Solaris components should pass a db_credp
         * for this message, hence we ASSERT.
         * On production kernels we return an error to be robust against
         * random streams modules sitting on top of us.
         */
        cr = msg_getcred(mp, &pid);
        ASSERT(cr != NULL);
        if (cr == NULL) {
                error = EINVAL;
                goto ud_error2;
        }

        /*
         * If a port has not been bound to the stream, fail.
         * This is not a problem when sockfs is directly
         * above us, because it will ensure that the socket
         * is first bound before allowing data to be sent.
         */
        if (icmp->icmp_state == TS_UNBND) {
                error = EPROTO;
                goto ud_error2;
        }
        addr = (struct sockaddr *)&mp->b_rptr[tudr->DEST_offset];
        addrlen = tudr->DEST_length;

        switch (connp->conn_family) {
        case AF_INET6:
                sin6 = (sin6_t *)addr;
                if (!OK_32PTR((char *)sin6) || (addrlen != sizeof (sin6_t)) ||
                    (sin6->sin6_family != AF_INET6)) {
                        error = EADDRNOTAVAIL;
                        goto ud_error2;
                }

                /* No support for mapped addresses on raw sockets */
                if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
                        error = EADDRNOTAVAIL;
                        goto ud_error2;
                }
                srcid = sin6->__sin6_src_id;

                /*
                 * If the local address is a mapped address return
                 * an error.
                 * It would be possible to send an IPv6 packet but the
                 * response would never make it back to the application
                 * since it is bound to a mapped address.
                 */
                if (IN6_IS_ADDR_V4MAPPED(&connp->conn_saddr_v6)) {
                        error = EADDRNOTAVAIL;
                        goto ud_error2;
                }

                if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr))
                        sin6->sin6_addr = ipv6_loopback;

                if (tudr->OPT_length != 0) {
                        /*
                         * If we are connected then the destination needs to be
                         * the same as the connected one.
                         */
                        if (icmp->icmp_state == TS_DATA_XFER &&
                            !conn_same_as_last_v6(connp, sin6)) {
                                error = EISCONN;
                                goto ud_error2;
                        }
                        error = icmp_output_ancillary(connp, NULL, sin6,
                            data_mp, mp, NULL, cr, pid);
                } else {
                        ip_xmit_attr_t *ixa;

                        /*
                         * We have to allocate an ip_xmit_attr_t before we grab
                         * conn_lock and we need to hold conn_lock once we've
                         * checked conn_same_as_last_v6 to handle concurrent
                         * send* calls on a socket.
                         */
                        ixa = conn_get_ixa(connp, B_FALSE);
                        if (ixa == NULL) {
                                error = ENOMEM;
                                goto ud_error2;
                        }
                        mutex_enter(&connp->conn_lock);

                        if (conn_same_as_last_v6(connp, sin6) &&
                            connp->conn_lastsrcid == srcid &&
                            ipsec_outbound_policy_current(ixa)) {
                                /* icmp_output_lastdst drops conn_lock */
                                error = icmp_output_lastdst(connp, data_mp, cr,
                                    pid, ixa);
                        } else {
                                /* icmp_output_newdst drops conn_lock */
                                error = icmp_output_newdst(connp, data_mp, NULL,
                                    sin6, cr, pid, ixa);
                        }
                        ASSERT(MUTEX_NOT_HELD(&connp->conn_lock));
                }
                if (error == 0) {
                        freeb(mp);
                        return (0);
                }
                break;

        case AF_INET:
                sin = (sin_t *)addr;
                if ((!OK_32PTR((char *)sin) || addrlen != sizeof (sin_t)) ||
                    (sin->sin_family != AF_INET)) {
                        error = EADDRNOTAVAIL;
                        goto ud_error2;
                }
                if (sin->sin_addr.s_addr == INADDR_ANY)
                        sin->sin_addr.s_addr = htonl(INADDR_LOOPBACK);

                /* Protocol 255 contains full IP headers */
                /* Read without holding lock */
                if (icmp->icmp_hdrincl) {
                        if (MBLKL(data_mp) < IP_SIMPLE_HDR_LENGTH) {
                                if (!pullupmsg(data_mp, IP_SIMPLE_HDR_LENGTH)) {
                                        error = EINVAL;
                                        goto ud_error2;
                                }
                        }
                        error = icmp_output_hdrincl(connp, data_mp, cr, pid);
                        if (error == 0) {
                                freeb(mp);
                                return (0);
                        }
                        /* data_mp consumed above */
                        data_mp = NULL;
                        goto ud_error2;
                }

                if (tudr->OPT_length != 0) {
                        /*
                         * If we are connected then the destination needs to be
                         * the same as the connected one.
                         */
                        if (icmp->icmp_state == TS_DATA_XFER &&
                            !conn_same_as_last_v4(connp, sin)) {
                                error = EISCONN;
                                goto ud_error2;
                        }
                        error = icmp_output_ancillary(connp, sin, NULL,
                            data_mp, mp, NULL, cr, pid);
                } else {
                        ip_xmit_attr_t *ixa;

                        /*
                         * We have to allocate an ip_xmit_attr_t before we grab
                         * conn_lock and we need to hold conn_lock once we've
                         * checked conn_same_as_last_v4 to handle concurrent
                         * send* calls on a socket.
                         */
                        ixa = conn_get_ixa(connp, B_FALSE);
                        if (ixa == NULL) {
                                error = ENOMEM;
                                goto ud_error2;
                        }
                        mutex_enter(&connp->conn_lock);

                        if (conn_same_as_last_v4(connp, sin) &&
                            ipsec_outbound_policy_current(ixa)) {
                                /* icmp_output_lastdst drops conn_lock */
                                error = icmp_output_lastdst(connp, data_mp, cr,
                                    pid, ixa);
                        } else {
                                /* icmp_output_newdst drops conn_lock */
                                error = icmp_output_newdst(connp, data_mp, sin,
                                    NULL, cr, pid, ixa);
                        }
                        ASSERT(MUTEX_NOT_HELD(&connp->conn_lock));
                }
                if (error == 0) {
                        freeb(mp);
                        return (0);
                }
                break;
        }
        ASSERT(mp != NULL);
        /* mp is freed by the following routine */
        icmp_ud_err(q, mp, (t_scalar_t)error);
        return (0);

ud_error2:
        BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
        freemsg(data_mp);
        ASSERT(mp != NULL);
        /* mp is freed by the following routine */
        icmp_ud_err(q, mp, (t_scalar_t)error);
        return (0);
}

/*
 * Handle the case of the IP address or flow label being different
 * for both IPv4 and IPv6.
 *
 * NOTE: The caller must hold conn_lock and we drop it here.
 */
static int
icmp_output_newdst(conn_t *connp, mblk_t *data_mp, sin_t *sin, sin6_t *sin6,
    cred_t *cr, pid_t pid, ip_xmit_attr_t *ixa)
{
        icmp_t          *icmp = connp->conn_icmp;
        icmp_stack_t    *is = icmp->icmp_is;
        int             error;
        ip_xmit_attr_t  *oldixa;
        boolean_t       do_ipsec;
        uint_t          srcid;
        uint32_t        flowinfo;
        in6_addr_t      v6src;
        in6_addr_t      v6dst;
        in6_addr_t      v6nexthop;
        in_port_t       dstport;

        ASSERT(MUTEX_HELD(&connp->conn_lock));
        ASSERT(ixa != NULL);

        /*
         * We hold conn_lock across all the use and modifications of
         * the conn_lastdst, conn_ixa, and conn_xmit_ipp to ensure that they
         * stay consistent.
         */

        ASSERT(cr != NULL);
        ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
        ixa->ixa_cred = cr;
        ixa->ixa_cpid = pid;
        if (is_system_labeled()) {
                /* We need to restart with a label based on the cred */
                ip_xmit_attr_restore_tsl(ixa, ixa->ixa_cred);
        }
        /*
         * If we are connected then the destination needs to be the
         * same as the connected one, which is not the case here since we
         * checked for that above.
         */
        if (icmp->icmp_state == TS_DATA_XFER) {
                mutex_exit(&connp->conn_lock);
                error = EISCONN;
                goto ud_error;
        }

        /*
         * Before we modify the ixa at all, invalidate our most recent address
         * to assure that any subsequent call to conn_same_as_last_v6() will
         * not indicate a match: any thread that picks up conn_lock after we
         * drop it (but before we pick it up again and properly set the most
         * recent address) must not associate the ixa with the (now old) last
         * address.
         */
        connp->conn_v6lastdst = ipv6_all_zeros;

        /* In case previous destination was multicast or multirt */
        ip_attr_newdst(ixa);

        /*
         * If laddr is unspecified then we look at sin6_src_id.
         * We will give precedence to a source address set with IPV6_PKTINFO
         * (aka IPPF_ADDR) but that is handled in build_hdrs. However, we don't
         * want ip_attr_connect to select a source (since it can fail) when
         * IPV6_PKTINFO is specified.
         * If this doesn't result in a source address then we get a source
         * from ip_attr_connect() below.
         */
        v6src = connp->conn_saddr_v6;
        if (sin != NULL) {
                IN6_IPADDR_TO_V4MAPPED(sin->sin_addr.s_addr, &v6dst);
                dstport = sin->sin_port;
                flowinfo = 0;
                /* Don't bother with ip_srcid_find_id(), but indicate anyway. */
                srcid = 0;
                ixa->ixa_flags &= ~IXAF_SCOPEID_SET;
                ixa->ixa_flags |= IXAF_IS_IPV4;
        } else {
                boolean_t v4mapped;

                v6dst = sin6->sin6_addr;
                dstport = sin6->sin6_port;
                flowinfo = sin6->sin6_flowinfo;
                srcid = sin6->__sin6_src_id;
                if (IN6_IS_ADDR_LINKSCOPE(&v6dst) && sin6->sin6_scope_id != 0) {
                        ixa->ixa_scopeid = sin6->sin6_scope_id;
                        ixa->ixa_flags |= IXAF_SCOPEID_SET;
                } else {
                        ixa->ixa_flags &= ~IXAF_SCOPEID_SET;
                }
                v4mapped = IN6_IS_ADDR_V4MAPPED(&v6dst);
                if (v4mapped)
                        ixa->ixa_flags |= IXAF_IS_IPV4;
                else
                        ixa->ixa_flags &= ~IXAF_IS_IPV4;
                if (srcid != 0 && IN6_IS_ADDR_UNSPECIFIED(&v6src)) {
                        if (!ip_srcid_find_id(srcid, &v6src, IPCL_ZONEID(connp),
                            v4mapped, connp->conn_netstack)) {
                                /* Mismatched v4mapped/v6 specified by srcid. */
                                mutex_exit(&connp->conn_lock);
                                error = EADDRNOTAVAIL;
                                goto ud_error;
                        }
                }
        }
        /* Handle IP_PKTINFO/IPV6_PKTINFO setting source address. */
        if (connp->conn_xmit_ipp.ipp_fields & IPPF_ADDR) {
                ip_pkt_t *ipp = &connp->conn_xmit_ipp;

                if (ixa->ixa_flags & IXAF_IS_IPV4) {
                        if (IN6_IS_ADDR_V4MAPPED(&ipp->ipp_addr))
                                v6src = ipp->ipp_addr;
                } else {
                        if (!IN6_IS_ADDR_V4MAPPED(&ipp->ipp_addr))
                                v6src = ipp->ipp_addr;
                }
        }

        /* Defer IPsec if it might need to look at ICMP type/code */
        switch (ixa->ixa_protocol) {
        case IPPROTO_ICMP:
        case IPPROTO_ICMPV6:
                do_ipsec = B_FALSE;
                break;
        default:
                do_ipsec = B_TRUE;
        }

        ip_attr_nexthop(&connp->conn_xmit_ipp, ixa, &v6dst, &v6nexthop);
        mutex_exit(&connp->conn_lock);

        error = ip_attr_connect(connp, ixa, &v6src, &v6dst, &v6nexthop, dstport,
            &v6src, NULL, IPDF_ALLOW_MCBC | IPDF_VERIFY_DST |
            (do_ipsec ? IPDF_IPSEC : 0));
        switch (error) {
        case 0:
                break;
        case EADDRNOTAVAIL:
                /*
                 * IXAF_VERIFY_SOURCE tells us to pick a better source.
                 * Don't have the application see that errno
                 */
                error = ENETUNREACH;
                goto failed;
        case ENETDOWN:
                /*
                 * Have !ipif_addr_ready address; drop packet silently
                 * until we can get applications to not send until we
                 * are ready.
                 */
                error = 0;
                goto failed;
        case EHOSTUNREACH:
        case ENETUNREACH:
                if (ixa->ixa_ire != NULL) {
                        /*
                         * Let conn_ip_output/ire_send_noroute return
                         * the error and send any local ICMP error.
                         */
                        error = 0;
                        break;
                }
                /* FALLTHRU */
        default:
        failed:
                goto ud_error;
        }

        mutex_enter(&connp->conn_lock);
        /*
         * While we dropped the lock some other thread might have connected
         * this socket. If so we bail out with EISCONN to ensure that the
         * connecting thread is the one that updates conn_ixa, conn_ht_*
         * and conn_*last*.
         */
        if (icmp->icmp_state == TS_DATA_XFER) {
                mutex_exit(&connp->conn_lock);
                error = EISCONN;
                goto ud_error;
        }

        /*
         * We need to rebuild the headers if
         *  - we are labeling packets (could be different for different
         *    destinations)
         *  - we have a source route (or routing header) since we need to
         *    massage that to get the pseudo-header checksum
         *  - a socket option with COA_HEADER_CHANGED has been set which
         *    set conn_v6lastdst to zero.
         *
         * Otherwise the prepend function will just update the src, dst,
         * and flow label.
         */
        if (is_system_labeled()) {
                /* TX MLP requires SCM_UCRED and don't have that here */
                if (connp->conn_mlp_type != mlptSingle) {
                        mutex_exit(&connp->conn_lock);
                        error = ECONNREFUSED;
                        goto ud_error;
                }
                /*
                 * Check whether Trusted Solaris policy allows communication
                 * with this host, and pretend that the destination is
                 * unreachable if not.
                 * Compute any needed label and place it in ipp_label_v4/v6.
                 *
                 * Later conn_build_hdr_template/conn_prepend_hdr takes
                 * ipp_label_v4/v6 to form the packet.
                 *
                 * Tsol note: Since we hold conn_lock we know no other
                 * thread manipulates conn_xmit_ipp.
                 */
                error = conn_update_label(connp, ixa, &v6dst,
                    &connp->conn_xmit_ipp);
                if (error != 0) {
                        mutex_exit(&connp->conn_lock);
                        goto ud_error;
                }
                /* Rebuild the header template */
                error = icmp_build_hdr_template(connp, &v6src, &v6dst,
                    flowinfo);
                if (error != 0) {
                        mutex_exit(&connp->conn_lock);
                        goto ud_error;
                }
        } else if (connp->conn_xmit_ipp.ipp_fields &
            (IPPF_IPV4_OPTIONS|IPPF_RTHDR) ||
            IN6_IS_ADDR_UNSPECIFIED(&connp->conn_v6lastdst)) {
                /* Rebuild the header template */
                error = icmp_build_hdr_template(connp, &v6src, &v6dst,
                    flowinfo);
                if (error != 0) {
                        mutex_exit(&connp->conn_lock);
                        goto ud_error;
                }
        } else {
                /* Simply update the destination address if no source route */
                if (ixa->ixa_flags & IXAF_IS_IPV4) {
                        ipha_t  *ipha = (ipha_t *)connp->conn_ht_iphc;

                        IN6_V4MAPPED_TO_IPADDR(&v6dst, ipha->ipha_dst);
                        if (ixa->ixa_flags & IXAF_PMTU_IPV4_DF) {
                                ipha->ipha_fragment_offset_and_flags |=
                                    IPH_DF_HTONS;
                        } else {
                                ipha->ipha_fragment_offset_and_flags &=
                                    ~IPH_DF_HTONS;
                        }
                } else {
                        ip6_t *ip6h = (ip6_t *)connp->conn_ht_iphc;
                        ip6h->ip6_dst = v6dst;
                }
        }

        /*
         * Remember the dst etc which corresponds to the built header
         * template and conn_ixa.
         */
        oldixa = conn_replace_ixa(connp, ixa);
        connp->conn_v6lastdst = v6dst;
        connp->conn_lastflowinfo = flowinfo;
        connp->conn_lastscopeid = ixa->ixa_scopeid;
        connp->conn_lastsrcid = srcid;
        /* Also remember a source to use together with lastdst */
        connp->conn_v6lastsrc = v6src;

        data_mp = icmp_prepend_header_template(connp, ixa, data_mp, &v6src,
            flowinfo, &error);

        /* Done with conn_t */
        mutex_exit(&connp->conn_lock);
        ixa_refrele(oldixa);

        if (data_mp == NULL) {
                ASSERT(error != 0);
                goto ud_error;
        }

        if (!do_ipsec) {
                /* Policy might differ for different ICMP type/code */
                data_mp = icmp_output_attach_policy(data_mp, connp, ixa);
                if (data_mp == NULL) {
                        BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                        error = EHOSTUNREACH;   /* IPsec policy failure */
                        goto done;
                }
        }

        /* We're done.  Pass the packet to ip. */
        BUMP_MIB(&is->is_rawip_mib, rawipOutDatagrams);

        error = conn_ip_output(data_mp, ixa);
        /* No rawipOutErrors if an error since IP increases its error counter */
        switch (error) {
        case 0:
                break;
        case EWOULDBLOCK:
                (void) ixa_check_drain_insert(connp, ixa);
                error = 0;
                break;
        case EADDRNOTAVAIL:
                /*
                 * IXAF_VERIFY_SOURCE tells us to pick a better source.
                 * Don't have the application see that errno
                 */
                error = ENETUNREACH;
                /* FALLTHRU */
        default:
                mutex_enter(&connp->conn_lock);
                /*
                 * Clear the source and v6lastdst so we call ip_attr_connect
                 * for the next packet and try to pick a better source.
                 */
                if (connp->conn_mcbc_bind)
                        connp->conn_saddr_v6 = ipv6_all_zeros;
                else
                        connp->conn_saddr_v6 = connp->conn_bound_addr_v6;
                connp->conn_v6lastdst = ipv6_all_zeros;
                mutex_exit(&connp->conn_lock);
                break;
        }
done:
        ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
        ixa->ixa_cred = connp->conn_cred;       /* Restore */
        ixa->ixa_cpid = connp->conn_cpid;
        ixa_refrele(ixa);
        return (error);

ud_error:
        ASSERT(!(ixa->ixa_free_flags & IXA_FREE_CRED));
        ixa->ixa_cred = connp->conn_cred;       /* Restore */
        ixa->ixa_cpid = connp->conn_cpid;
        ixa_refrele(ixa);

        BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
        freemsg(data_mp);
        return (error);
}

/* ARGSUSED */
static int
icmp_wput_fallback(queue_t *q, mblk_t *mp)
{
#ifdef DEBUG
        cmn_err(CE_CONT, "icmp_wput_fallback: Message during fallback \n");
#endif
        freemsg(mp);
        return (0);
}

static void
icmp_wput_other(queue_t *q, mblk_t *mp)
{
        uchar_t *rptr = mp->b_rptr;
        struct iocblk *iocp;
        conn_t  *connp = Q_TO_CONN(q);
        icmp_t  *icmp = connp->conn_icmp;
        cred_t *cr;

        switch (mp->b_datap->db_type) {
        case M_PROTO:
        case M_PCPROTO:
                if (mp->b_wptr - rptr < sizeof (t_scalar_t)) {
                        /*
                         * If the message does not contain a PRIM_type,
                         * throw it away.
                         */
                        freemsg(mp);
                        return;
                }
                switch (((t_primp_t)rptr)->type) {
                case T_ADDR_REQ:
                        icmp_addr_req(q, mp);
                        return;
                case O_T_BIND_REQ:
                case T_BIND_REQ:
                        icmp_tpi_bind(q, mp);
                        return;
                case T_CONN_REQ:
                        icmp_tpi_connect(q, mp);
                        return;
                case T_CAPABILITY_REQ:
                        icmp_capability_req(q, mp);
                        return;
                case T_INFO_REQ:
                        icmp_info_req(q, mp);
                        return;
                case T_UNITDATA_REQ:
                        /*
                         * If a T_UNITDATA_REQ gets here, the address must
                         * be bad.  Valid T_UNITDATA_REQs are handled
                         * in icmp_wput.
                         */
                        icmp_ud_err(q, mp, EADDRNOTAVAIL);
                        return;
                case T_UNBIND_REQ:
                        icmp_tpi_unbind(q, mp);
                        return;
                case T_SVR4_OPTMGMT_REQ:
                        /*
                         * 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) {
                                icmp_err_ack(q, mp, TSYSERR, EINVAL);
                                return;
                        }

                        if (!snmpcom_req(q, mp, icmp_snmp_set, ip_snmp_get,
                            cr)) {
                                svr4_optcom_req(q, mp, cr, &icmp_opt_obj);
                        }
                        return;

                case T_OPTMGMT_REQ:
                        /*
                         * 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) {
                                icmp_err_ack(q, mp, TSYSERR, EINVAL);
                                return;
                        }
                        tpi_optcom_req(q, mp, cr, &icmp_opt_obj);
                        return;

                case T_DISCON_REQ:
                        icmp_tpi_disconnect(q, mp);
                        return;

                /* The following TPI message is not supported by icmp. */
                case O_T_CONN_RES:
                case T_CONN_RES:
                        icmp_err_ack(q, mp, TNOTSUPPORT, 0);
                        return;

                /* The following 3 TPI requests are illegal for icmp. */
                case T_DATA_REQ:
                case T_EXDATA_REQ:
                case T_ORDREL_REQ:
                        icmp_err_ack(q, mp, TNOTSUPPORT, 0);
                        return;
                default:
                        break;
                }
                break;
        case M_FLUSH:
                if (*rptr & FLUSHW)
                        flushq(q, FLUSHDATA);
                break;
        case M_IOCTL:
                iocp = (struct iocblk *)mp->b_rptr;
                switch (iocp->ioc_cmd) {
                case TI_GETPEERNAME:
                        if (icmp->icmp_state != TS_DATA_XFER) {
                                /*
                                 * If a default destination address has not
                                 * been associated with the stream, then we
                                 * don't know the peer's name.
                                 */
                                iocp->ioc_error = ENOTCONN;
                                iocp->ioc_count = 0;
                                mp->b_datap->db_type = M_IOCACK;
                                qreply(q, mp);
                                return;
                        }
                        /* FALLTHRU */
                case TI_GETMYNAME:
                        /*
                         * For TI_GETPEERNAME and TI_GETMYNAME, we first
                         * need to copyin the user's strbuf structure.
                         * Processing will continue in the M_IOCDATA case
                         * below.
                         */
                        mi_copyin(q, mp, NULL,
                            SIZEOF_STRUCT(strbuf, iocp->ioc_flag));
                        return;
                default:
                        break;
                }
                break;
        case M_IOCDATA:
                icmp_wput_iocdata(q, mp);
                return;
        default:
                /* Unrecognized messages are passed through without change. */
                break;
        }
        ip_wput_nondata(q, mp);
}

/*
 * icmp_wput_iocdata is called by icmp_wput_other to handle all M_IOCDATA
 * messages.
 */
static void
icmp_wput_iocdata(queue_t *q, mblk_t *mp)
{
        mblk_t          *mp1;
        STRUCT_HANDLE(strbuf, sb);
        uint_t          addrlen;
        conn_t          *connp = Q_TO_CONN(q);
        icmp_t          *icmp = connp->conn_icmp;

        /* Make sure it is one of ours. */
        switch (((struct iocblk *)mp->b_rptr)->ioc_cmd) {
        case TI_GETMYNAME:
        case TI_GETPEERNAME:
                break;
        default:
                ip_wput_nondata(q, mp);
                return;
        }

        switch (mi_copy_state(q, mp, &mp1)) {
        case -1:
                return;
        case MI_COPY_CASE(MI_COPY_IN, 1):
                break;
        case MI_COPY_CASE(MI_COPY_OUT, 1):
                /*
                 * The address has been copied out, so now
                 * copyout the strbuf.
                 */
                mi_copyout(q, mp);
                return;
        case MI_COPY_CASE(MI_COPY_OUT, 2):
                /*
                 * The address and strbuf have been copied out.
                 * We're done, so just acknowledge the original
                 * M_IOCTL.
                 */
                mi_copy_done(q, mp, 0);
                return;
        default:
                /*
                 * Something strange has happened, so acknowledge
                 * the original M_IOCTL with an EPROTO error.
                 */
                mi_copy_done(q, mp, EPROTO);
                return;
        }

        /*
         * Now we have the strbuf structure for TI_GETMYNAME
         * and TI_GETPEERNAME.  Next we copyout the requested
         * address and then we'll copyout the strbuf.
         */
        STRUCT_SET_HANDLE(sb, ((struct iocblk *)mp->b_rptr)->ioc_flag,
            (void *)mp1->b_rptr);

        if (connp->conn_family == AF_INET)
                addrlen = sizeof (sin_t);
        else
                addrlen = sizeof (sin6_t);

        if (STRUCT_FGET(sb, maxlen) < addrlen) {
                mi_copy_done(q, mp, EINVAL);
                return;
        }
        switch (((struct iocblk *)mp->b_rptr)->ioc_cmd) {
        case TI_GETMYNAME:
                break;
        case TI_GETPEERNAME:
                if (icmp->icmp_state != TS_DATA_XFER) {
                        mi_copy_done(q, mp, ENOTCONN);
                        return;
                }
                break;
        default:
                mi_copy_done(q, mp, EPROTO);
                return;
        }
        mp1 = mi_copyout_alloc(q, mp, STRUCT_FGETP(sb, buf), addrlen, B_TRUE);
        if (!mp1)
                return;

        STRUCT_FSET(sb, len, addrlen);
        switch (((struct iocblk *)mp->b_rptr)->ioc_cmd) {
        case TI_GETMYNAME:
                (void) conn_getsockname(connp, (struct sockaddr *)mp1->b_wptr,
                    &addrlen);
                break;
        case TI_GETPEERNAME:
                (void) conn_getpeername(connp, (struct sockaddr *)mp1->b_wptr,
                    &addrlen);
                break;
        }
        mp1->b_wptr += addrlen;
        /* Copy out the address */
        mi_copyout(q, mp);
}

void
icmp_ddi_g_init(void)
{
        icmp_max_optsize = optcom_max_optsize(icmp_opt_obj.odb_opt_des_arr,
            icmp_opt_obj.odb_opt_arr_cnt);

        /*
         * We want to be informed each time a stack is created or
         * destroyed in the kernel, so we can maintain the
         * set of icmp_stack_t's.
         */
        netstack_register(NS_ICMP, rawip_stack_init, NULL, rawip_stack_fini);
}

void
icmp_ddi_g_destroy(void)
{
        netstack_unregister(NS_ICMP);
}

#define INET_NAME       "ip"

/*
 * Initialize the ICMP stack instance.
 */
static void *
rawip_stack_init(netstackid_t stackid, netstack_t *ns)
{
        icmp_stack_t    *is;
        int             error = 0;
        size_t          arrsz;
        major_t         major;

        is = (icmp_stack_t *)kmem_zalloc(sizeof (*is), KM_SLEEP);
        is->is_netstack = ns;

        arrsz = sizeof (icmp_propinfo_tbl);
        is->is_propinfo_tbl = (mod_prop_info_t *)kmem_alloc(arrsz, KM_SLEEP);
        bcopy(icmp_propinfo_tbl, is->is_propinfo_tbl, arrsz);

        is->is_ksp = rawip_kstat_init(stackid);

        major = mod_name_to_major(INET_NAME);
        error = ldi_ident_from_major(major, &is->is_ldi_ident);
        ASSERT(error == 0);
        return (is);
}

/*
 * Free the ICMP stack instance.
 */
static void
rawip_stack_fini(netstackid_t stackid, void *arg)
{
        icmp_stack_t *is = (icmp_stack_t *)arg;

        kmem_free(is->is_propinfo_tbl, sizeof (icmp_propinfo_tbl));
        is->is_propinfo_tbl = NULL;

        rawip_kstat_fini(stackid, is->is_ksp);
        is->is_ksp = NULL;
        ldi_ident_release(is->is_ldi_ident);
        kmem_free(is, sizeof (*is));
}

static void *
rawip_kstat_init(netstackid_t stackid)
{
        kstat_t *ksp;

        rawip_named_kstat_t template = {
                { "inDatagrams",        KSTAT_DATA_UINT32, 0 },
                { "inCksumErrs",        KSTAT_DATA_UINT32, 0 },
                { "inErrors",           KSTAT_DATA_UINT32, 0 },
                { "outDatagrams",       KSTAT_DATA_UINT32, 0 },
                { "outErrors",          KSTAT_DATA_UINT32, 0 },
        };

        ksp = kstat_create_netstack("icmp", 0, "rawip", "mib2",
            KSTAT_TYPE_NAMED, NUM_OF_FIELDS(rawip_named_kstat_t), 0, stackid);
        if (ksp == NULL || ksp->ks_data == NULL)
                return (NULL);

        bcopy(&template, ksp->ks_data, sizeof (template));
        ksp->ks_update = rawip_kstat_update;
        ksp->ks_private = (void *)(uintptr_t)stackid;

        kstat_install(ksp);
        return (ksp);
}

static void
rawip_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
rawip_kstat_update(kstat_t *ksp, int rw)
{
        rawip_named_kstat_t *rawipkp;
        netstackid_t    stackid = (netstackid_t)(uintptr_t)ksp->ks_private;
        netstack_t      *ns;
        icmp_stack_t    *is;

        if (ksp->ks_data == NULL)
                return (EIO);

        if (rw == KSTAT_WRITE)
                return (EACCES);

        rawipkp = (rawip_named_kstat_t *)ksp->ks_data;

        ns = netstack_find_by_stackid(stackid);
        if (ns == NULL)
                return (-1);
        is = ns->netstack_icmp;
        if (is == NULL) {
                netstack_rele(ns);
                return (-1);
        }
        rawipkp->inDatagrams.value.ui32 =  is->is_rawip_mib.rawipInDatagrams;
        rawipkp->inCksumErrs.value.ui32 =  is->is_rawip_mib.rawipInCksumErrs;
        rawipkp->inErrors.value.ui32 =     is->is_rawip_mib.rawipInErrors;
        rawipkp->outDatagrams.value.ui32 = is->is_rawip_mib.rawipOutDatagrams;
        rawipkp->outErrors.value.ui32 =    is->is_rawip_mib.rawipOutErrors;
        netstack_rele(ns);
        return (0);
}

/* ARGSUSED */
int
rawip_accept(sock_lower_handle_t lproto_handle,
    sock_lower_handle_t eproto_handle, sock_upper_handle_t sock_handle,
    cred_t *cr)
{
        return (EOPNOTSUPP);
}

/* ARGSUSED */
int
rawip_bind(sock_lower_handle_t proto_handle, struct sockaddr *sa,
    socklen_t len, cred_t *cr)
{
        conn_t  *connp = (conn_t *)proto_handle;
        int     error;

        /* All Solaris components should pass a cred for this operation. */
        ASSERT(cr != NULL);

        /* Binding to a NULL address really means unbind */
        if (sa == NULL)
                error = rawip_do_unbind(connp);
        else
                error = rawip_do_bind(connp, sa, len);

        if (error < 0) {
                if (error == -TOUTSTATE)
                        error = EINVAL;
                else
                        error = proto_tlitosyserr(-error);
        }
        return (error);
}

static int
rawip_implicit_bind(conn_t *connp)
{
        sin6_t sin6addr;
        sin_t *sin;
        sin6_t *sin6;
        socklen_t len;
        int error;

        if (connp->conn_family == AF_INET) {
                len = sizeof (struct sockaddr_in);
                sin = (sin_t *)&sin6addr;
                *sin = sin_null;
                sin->sin_family = AF_INET;
                sin->sin_addr.s_addr = INADDR_ANY;
        } else {
                ASSERT(connp->conn_family == AF_INET6);
                len = sizeof (sin6_t);
                sin6 = (sin6_t *)&sin6addr;
                *sin6 = sin6_null;
                sin6->sin6_family = AF_INET6;
                V6_SET_ZERO(sin6->sin6_addr);
        }

        error = rawip_do_bind(connp, (struct sockaddr *)&sin6addr, len);

        return ((error < 0) ? proto_tlitosyserr(-error) : error);
}

static int
rawip_unbind(conn_t *connp)
{
        int error;

        error = rawip_do_unbind(connp);
        if (error < 0) {
                error = proto_tlitosyserr(-error);
        }
        return (error);
}

/* ARGSUSED */
int
rawip_listen(sock_lower_handle_t proto_handle, int backlog, cred_t *cr)
{
        return (EOPNOTSUPP);
}

int
rawip_connect(sock_lower_handle_t proto_handle, const struct sockaddr *sa,
    socklen_t len, sock_connid_t *id, cred_t *cr)
{
        conn_t  *connp = (conn_t *)proto_handle;
        icmp_t *icmp = connp->conn_icmp;
        int     error;
        boolean_t did_bind = B_FALSE;
        pid_t   pid = curproc->p_pid;

        /* All Solaris components should pass a cred for this operation. */
        ASSERT(cr != NULL);

        if (sa == NULL) {
                /*
                 * Disconnect
                 * Make sure we are connected
                 */
                if (icmp->icmp_state != TS_DATA_XFER)
                        return (EINVAL);

                error = icmp_disconnect(connp);
                return (error);
        }

        error = proto_verify_ip_addr(connp->conn_family, sa, len);
        if (error != 0)
                return (error);

        /* do an implicit bind if necessary */
        if (icmp->icmp_state == TS_UNBND) {
                error = rawip_implicit_bind(connp);
                /*
                 * We could be racing with an actual bind, in which case
                 * we would see EPROTO. We cross our fingers and try
                 * to connect.
                 */
                if (!(error == 0 || error == EPROTO))
                        return (error);
                did_bind = B_TRUE;
        }

        /*
         * set SO_DGRAM_ERRIND
         */
        connp->conn_dgram_errind = B_TRUE;

        error = rawip_do_connect(connp, sa, len, cr, pid);
        if (error != 0 && did_bind) {
                int unbind_err;

                unbind_err = rawip_unbind(connp);
                ASSERT(unbind_err == 0);
        }

        if (error == 0) {
                *id = 0;
                (*connp->conn_upcalls->su_connected)(connp->conn_upper_handle,
                    0, NULL, -1);
        } else if (error < 0) {
                error = proto_tlitosyserr(-error);
        }
        return (error);
}

/* ARGSUSED2 */
int
rawip_fallback(sock_lower_handle_t proto_handle, queue_t *q,
    boolean_t direct_sockfs, so_proto_quiesced_cb_t quiesced_cb,
    sock_quiesce_arg_t *arg)
{
        conn_t  *connp = (conn_t *)proto_handle;
        icmp_t  *icmp;
        struct T_capability_ack tca;
        struct sockaddr_in6 laddr, faddr;
        socklen_t laddrlen, faddrlen;
        short opts;
        struct stroptions *stropt;
        mblk_t *mp, *stropt_mp;
        int error;

        icmp = connp->conn_icmp;

        stropt_mp = allocb_wait(sizeof (*stropt), BPRI_HI, STR_NOSIG, NULL);

        /*
         * setup the fallback stream that was allocated
         */
        connp->conn_dev = (dev_t)RD(q)->q_ptr;
        connp->conn_minor_arena = WR(q)->q_ptr;

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

        WR(q)->q_qinfo = &icmpwinit;

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

        /* Notify stream head about options before sending up data */
        stropt_mp->b_datap->db_type = M_SETOPTS;
        stropt_mp->b_wptr += sizeof (*stropt);
        stropt = (struct stroptions *)stropt_mp->b_rptr;
        stropt->so_flags = SO_WROFF | SO_HIWAT;
        stropt->so_wroff = connp->conn_wroff;
        stropt->so_hiwat = connp->conn_rcvbuf;
        putnext(RD(q), stropt_mp);

        /*
         * free helper stream
         */
        ip_free_helper_stream(connp);

        /*
         * Collect the information needed to sync with the sonode
         */
        icmp_do_capability_ack(icmp, &tca, TC1_INFO);

        laddrlen = faddrlen = sizeof (sin6_t);
        (void) rawip_getsockname((sock_lower_handle_t)connp,
            (struct sockaddr *)&laddr, &laddrlen, CRED());
        error = rawip_getpeername((sock_lower_handle_t)connp,
            (struct sockaddr *)&faddr, &faddrlen, CRED());
        if (error != 0)
                faddrlen = 0;
        opts = 0;
        if (connp->conn_dgram_errind)
                opts |= SO_DGRAM_ERRIND;
        if (connp->conn_ixa->ixa_flags & IXAF_DONTROUTE)
                opts |= SO_DONTROUTE;

        mp = (*quiesced_cb)(connp->conn_upper_handle, arg, &tca,
            (struct sockaddr *)&laddr, laddrlen,
            (struct sockaddr *)&faddr, faddrlen, opts);

        /*
         * Attempts to send data up during fallback will result in it being
         * queued in icmp_t. Now we push up any queued packets.
         */
        mutex_enter(&icmp->icmp_recv_lock);
        if (mp != NULL) {
                mp->b_next = icmp->icmp_fallback_queue_head;
                icmp->icmp_fallback_queue_head = mp;
        }
        while (icmp->icmp_fallback_queue_head != NULL) {
                mp = icmp->icmp_fallback_queue_head;
                icmp->icmp_fallback_queue_head = mp->b_next;
                mp->b_next = NULL;
                mutex_exit(&icmp->icmp_recv_lock);
                putnext(RD(q), mp);
                mutex_enter(&icmp->icmp_recv_lock);
        }
        icmp->icmp_fallback_queue_tail = icmp->icmp_fallback_queue_head;

        /*
         * No longer a streams less socket
         */
        mutex_enter(&connp->conn_lock);
        connp->conn_flags &= ~IPCL_NONSTR;
        mutex_exit(&connp->conn_lock);

        mutex_exit(&icmp->icmp_recv_lock);

        ASSERT(icmp->icmp_fallback_queue_head == NULL &&
            icmp->icmp_fallback_queue_tail == NULL);

        ASSERT(connp->conn_ref >= 1);

        return (0);
}

/* ARGSUSED2 */
sock_lower_handle_t
rawip_create(int family, int type, int proto, sock_downcalls_t **sock_downcalls,
    uint_t *smodep, int *errorp, int flags, cred_t *credp)
{
        conn_t *connp;

        if (type != SOCK_RAW || (family != AF_INET && family != AF_INET6)) {
                *errorp = EPROTONOSUPPORT;
                return (NULL);
        }

        connp = rawip_do_open(family, credp, errorp, flags);
        if (connp != NULL) {
                connp->conn_flags |= IPCL_NONSTR;

                mutex_enter(&connp->conn_lock);
                connp->conn_state_flags &= ~CONN_INCIPIENT;
                mutex_exit(&connp->conn_lock);
                *sock_downcalls = &sock_rawip_downcalls;
                *smodep = SM_ATOMIC;
        } else {
                ASSERT(*errorp != 0);
        }

        return ((sock_lower_handle_t)connp);
}

/* ARGSUSED3 */
void
rawip_activate(sock_lower_handle_t proto_handle,
    sock_upper_handle_t sock_handle, sock_upcalls_t *sock_upcalls, int flags,
    cred_t *cr)
{
        conn_t *connp = (conn_t *)proto_handle;
        struct sock_proto_props sopp;

        /* All Solaris components should pass a cred for this operation. */
        ASSERT(cr != NULL);

        connp->conn_upcalls = sock_upcalls;
        connp->conn_upper_handle = sock_handle;

        sopp.sopp_flags = SOCKOPT_WROFF | SOCKOPT_RCVHIWAT | SOCKOPT_RCVLOWAT |
            SOCKOPT_MAXBLK | SOCKOPT_MAXPSZ | SOCKOPT_MINPSZ;
        sopp.sopp_wroff = connp->conn_wroff;
        sopp.sopp_rxhiwat = connp->conn_rcvbuf;
        sopp.sopp_rxlowat = connp->conn_rcvlowat;
        sopp.sopp_maxblk = INFPSZ;
        sopp.sopp_maxpsz = IP_MAXPACKET;
        sopp.sopp_minpsz = (icmp_mod_info.mi_minpsz == 1) ? 0 :
            icmp_mod_info.mi_minpsz;

        (*connp->conn_upcalls->su_set_proto_props)
            (connp->conn_upper_handle, &sopp);

        icmp_bind_proto(connp->conn_icmp);
}

/* ARGSUSED3 */
int
rawip_getpeername(sock_lower_handle_t proto_handle, struct sockaddr *sa,
    socklen_t *salenp, cred_t *cr)
{
        conn_t  *connp = (conn_t *)proto_handle;
        icmp_t  *icmp = connp->conn_icmp;
        int     error;

        /* All Solaris components should pass a cred for this operation. */
        ASSERT(cr != NULL);

        mutex_enter(&connp->conn_lock);
        if (icmp->icmp_state != TS_DATA_XFER)
                error = ENOTCONN;
        else
                error = conn_getpeername(connp, sa, salenp);
        mutex_exit(&connp->conn_lock);
        return (error);
}

/* ARGSUSED3 */
int
rawip_getsockname(sock_lower_handle_t proto_handle, struct sockaddr *sa,
    socklen_t *salenp, cred_t *cr)
{
        conn_t  *connp = (conn_t *)proto_handle;
        int     error;

        /* All Solaris components should pass a cred for this operation. */
        ASSERT(cr != NULL);

        mutex_enter(&connp->conn_lock);
        error = conn_getsockname(connp, sa, salenp);
        mutex_exit(&connp->conn_lock);
        return (error);
}

int
rawip_setsockopt(sock_lower_handle_t proto_handle, int level, int option_name,
    const void *optvalp, socklen_t optlen, cred_t *cr)
{
        conn_t  *connp = (conn_t *)proto_handle;
        int error;

        /* All Solaris components should pass a cred for this operation. */
        ASSERT(cr != NULL);

        error = proto_opt_check(level, option_name, optlen, NULL,
            icmp_opt_obj.odb_opt_des_arr,
            icmp_opt_obj.odb_opt_arr_cnt,
            B_TRUE, B_FALSE, cr);

        if (error != 0) {
                /*
                 * option not recognized
                 */
                if (error < 0) {
                        error = proto_tlitosyserr(-error);
                }
                return (error);
        }

        error = icmp_opt_set(connp, SETFN_OPTCOM_NEGOTIATE, level,
            option_name, optlen, (uchar_t *)optvalp, (uint_t *)&optlen,
            (uchar_t *)optvalp, NULL, cr);

        ASSERT(error >= 0);

        return (error);
}

int
rawip_getsockopt(sock_lower_handle_t proto_handle, int level, int option_name,
    void *optvalp, socklen_t *optlen, cred_t *cr)
{
        int             error;
        conn_t          *connp = (conn_t *)proto_handle;
        t_uscalar_t     max_optbuf_len;
        void            *optvalp_buf;
        int             len;

        /* All Solaris components should pass a cred for this operation. */
        ASSERT(cr != NULL);

        error = proto_opt_check(level, option_name, *optlen, &max_optbuf_len,
            icmp_opt_obj.odb_opt_des_arr,
            icmp_opt_obj.odb_opt_arr_cnt,
            B_FALSE, B_TRUE, cr);

        if (error != 0) {
                if (error < 0) {
                        error = proto_tlitosyserr(-error);
                }
                return (error);
        }

        optvalp_buf = kmem_alloc(max_optbuf_len, KM_SLEEP);
        len = icmp_opt_get(connp, level, option_name, optvalp_buf);
        if (len == -1) {
                kmem_free(optvalp_buf, max_optbuf_len);
                return (EINVAL);
        }

        /*
         * update optlen and copy option value
         */
        t_uscalar_t size = MIN(len, *optlen);

        bcopy(optvalp_buf, optvalp, size);
        bcopy(&size, optlen, sizeof (size));

        kmem_free(optvalp_buf, max_optbuf_len);
        return (0);
}

/* ARGSUSED1 */
int
rawip_close(sock_lower_handle_t proto_handle, int flags, cred_t *cr)
{
        conn_t  *connp = (conn_t *)proto_handle;

        /* All Solaris components should pass a cred for this operation. */
        ASSERT(cr != NULL);

        (void) rawip_do_close(connp);
        return (0);
}

/* ARGSUSED2 */
int
rawip_shutdown(sock_lower_handle_t proto_handle, int how, cred_t *cr)
{
        conn_t  *connp = (conn_t *)proto_handle;

        /* All Solaris components should pass a cred for this operation. */
        ASSERT(cr != NULL);

        /* shut down the send side */
        if (how != SHUT_RD)
                (*connp->conn_upcalls->su_opctl)(connp->conn_upper_handle,
                    SOCK_OPCTL_SHUT_SEND, 0);
        /* shut down the recv side */
        if (how != SHUT_WR)
                (*connp->conn_upcalls->su_opctl)(connp->conn_upper_handle,
                    SOCK_OPCTL_SHUT_RECV, 0);
        return (0);
}

void
rawip_clr_flowctrl(sock_lower_handle_t proto_handle)
{
        conn_t  *connp = (conn_t *)proto_handle;
        icmp_t  *icmp = connp->conn_icmp;

        mutex_enter(&icmp->icmp_recv_lock);
        connp->conn_flow_cntrld = B_FALSE;
        mutex_exit(&icmp->icmp_recv_lock);
}

int
rawip_ioctl(sock_lower_handle_t proto_handle, int cmd, intptr_t arg,
    int mode, int32_t *rvalp, cred_t *cr)
{
        conn_t          *connp = (conn_t *)proto_handle;
        int             error;

        /* All Solaris components should pass a cred for this operation. */
        ASSERT(cr != NULL);

        /*
         * If we don't have a helper stream then create one.
         * ip_create_helper_stream takes care of locking the conn_t,
         * so this check for NULL is just a performance optimization.
         */
        if (connp->conn_helper_info == NULL) {
                icmp_stack_t *is = connp->conn_icmp->icmp_is;

                ASSERT(is->is_ldi_ident != NULL);

                /*
                 * Create a helper stream for non-STREAMS socket.
                 */
                error = ip_create_helper_stream(connp, is->is_ldi_ident);
                if (error != 0) {
                        ip0dbg(("rawip_ioctl: create of IP helper stream "
                            "failed %d\n", error));
                        return (error);
                }
        }

        switch (cmd) {
        case _SIOCSOCKFALLBACK:
        case TI_GETPEERNAME:
        case TI_GETMYNAME:
#ifdef DEBUG
                cmn_err(CE_CONT, "icmp_ioctl cmd 0x%x on non streams"
                    " socket", cmd);
#endif
                error = EINVAL;
                break;
        default:
                /*
                 * Pass on to IP using helper stream
                 */
                error = ldi_ioctl(connp->conn_helper_info->iphs_handle,
                    cmd, arg, mode, cr, rvalp);
                break;
        }
        return (error);
}

int
rawip_send(sock_lower_handle_t proto_handle, mblk_t *mp, struct nmsghdr *msg,
    cred_t *cr)
{
        sin6_t          *sin6;
        sin_t           *sin = NULL;
        uint_t          srcid;
        conn_t          *connp = (conn_t *)proto_handle;
        icmp_t          *icmp = connp->conn_icmp;
        int             error = 0;
        icmp_stack_t    *is = icmp->icmp_is;
        pid_t           pid = curproc->p_pid;
        ip_xmit_attr_t  *ixa;

        ASSERT(DB_TYPE(mp) == M_DATA);

        /* All Solaris components should pass a cred for this operation. */
        ASSERT(cr != NULL);

        /* do an implicit bind if necessary */
        if (icmp->icmp_state == TS_UNBND) {
                error = rawip_implicit_bind(connp);
                /*
                 * We could be racing with an actual bind, in which case
                 * we would see EPROTO. We cross our fingers and try
                 * to connect.
                 */
                if (!(error == 0 || error == EPROTO)) {
                        freemsg(mp);
                        return (error);
                }
        }

        /* Protocol 255 contains full IP headers */
        /* Read without holding lock */
        if (icmp->icmp_hdrincl) {
                ASSERT(connp->conn_ipversion == IPV4_VERSION);
                if (mp->b_wptr - mp->b_rptr < IP_SIMPLE_HDR_LENGTH) {
                        if (!pullupmsg(mp, IP_SIMPLE_HDR_LENGTH)) {
                                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                                freemsg(mp);
                                return (EINVAL);
                        }
                }
                error = icmp_output_hdrincl(connp, mp, cr, pid);
                if (is->is_sendto_ignerr)
                        return (0);
                else
                        return (error);
        }

        /* Connected? */
        if (msg->msg_name == NULL) {
                if (icmp->icmp_state != TS_DATA_XFER) {
                        BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                        return (EDESTADDRREQ);
                }
                if (msg->msg_controllen != 0) {
                        error = icmp_output_ancillary(connp, NULL, NULL, mp,
                            NULL, msg, cr, pid);
                } else {
                        error = icmp_output_connected(connp, mp, cr, pid);
                }
                if (is->is_sendto_ignerr)
                        return (0);
                else
                        return (error);
        }
        if (icmp->icmp_state == TS_DATA_XFER) {
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                return (EISCONN);
        }
        error = proto_verify_ip_addr(connp->conn_family,
            (struct sockaddr *)msg->msg_name, msg->msg_namelen);
        if (error != 0) {
                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                return (error);
        }
        switch (connp->conn_family) {
        case AF_INET6:
                sin6 = (sin6_t *)msg->msg_name;

                /* No support for mapped addresses on raw sockets */
                if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
                        BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                        return (EADDRNOTAVAIL);
                }
                srcid = sin6->__sin6_src_id;

                /*
                 * If the local address is a mapped address return
                 * an error.
                 * It would be possible to send an IPv6 packet but the
                 * response would never make it back to the application
                 * since it is bound to a mapped address.
                 */
                if (IN6_IS_ADDR_V4MAPPED(&connp->conn_saddr_v6)) {
                        BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                        return (EADDRNOTAVAIL);
                }

                if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr))
                        sin6->sin6_addr = ipv6_loopback;

                /*
                 * We have to allocate an ip_xmit_attr_t before we grab
                 * conn_lock and we need to hold conn_lock once we've check
                 * conn_same_as_last_v6 to handle concurrent send* calls on a
                 * socket.
                 */
                if (msg->msg_controllen == 0) {
                        ixa = conn_get_ixa(connp, B_FALSE);
                        if (ixa == NULL) {
                                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                                return (ENOMEM);
                        }
                } else {
                        ixa = NULL;
                }
                mutex_enter(&connp->conn_lock);
                if (icmp->icmp_delayed_error != 0) {
                        sin6_t  *sin2 = (sin6_t *)&icmp->icmp_delayed_addr;

                        error = icmp->icmp_delayed_error;
                        icmp->icmp_delayed_error = 0;

                        /* Compare IP address and family */

                        if (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr,
                            &sin2->sin6_addr) &&
                            sin6->sin6_family == sin2->sin6_family) {
                                mutex_exit(&connp->conn_lock);
                                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                                if (ixa != NULL)
                                        ixa_refrele(ixa);
                                return (error);
                        }
                }
                if (msg->msg_controllen != 0) {
                        mutex_exit(&connp->conn_lock);
                        ASSERT(ixa == NULL);
                        error = icmp_output_ancillary(connp, NULL, sin6, mp,
                            NULL, msg, cr, pid);
                } else if (conn_same_as_last_v6(connp, sin6) &&
                    connp->conn_lastsrcid == srcid &&
                    ipsec_outbound_policy_current(ixa)) {
                        /* icmp_output_lastdst drops conn_lock */
                        error = icmp_output_lastdst(connp, mp, cr, pid, ixa);
                } else {
                        /* icmp_output_newdst drops conn_lock */
                        error = icmp_output_newdst(connp, mp, NULL, sin6, cr,
                            pid, ixa);
                }
                ASSERT(MUTEX_NOT_HELD(&connp->conn_lock));
                if (is->is_sendto_ignerr)
                        return (0);
                else
                        return (error);
        case AF_INET:
                sin = (sin_t *)msg->msg_name;

                if (sin->sin_addr.s_addr == INADDR_ANY)
                        sin->sin_addr.s_addr = htonl(INADDR_LOOPBACK);

                /*
                 * We have to allocate an ip_xmit_attr_t before we grab
                 * conn_lock and we need to hold conn_lock once we've check
                 * conn_same_as_last_v6 to handle concurrent send* on a socket.
                 */
                if (msg->msg_controllen == 0) {
                        ixa = conn_get_ixa(connp, B_FALSE);
                        if (ixa == NULL) {
                                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                                return (ENOMEM);
                        }
                } else {
                        ixa = NULL;
                }
                mutex_enter(&connp->conn_lock);
                if (icmp->icmp_delayed_error != 0) {
                        sin_t  *sin2 = (sin_t *)&icmp->icmp_delayed_addr;

                        error = icmp->icmp_delayed_error;
                        icmp->icmp_delayed_error = 0;

                        /* Compare IP address */

                        if (sin->sin_addr.s_addr == sin2->sin_addr.s_addr) {
                                mutex_exit(&connp->conn_lock);
                                BUMP_MIB(&is->is_rawip_mib, rawipOutErrors);
                                if (ixa != NULL)
                                        ixa_refrele(ixa);
                                return (error);
                        }
                }

                if (msg->msg_controllen != 0) {
                        mutex_exit(&connp->conn_lock);
                        ASSERT(ixa == NULL);
                        error = icmp_output_ancillary(connp, sin, NULL, mp,
                            NULL, msg, cr, pid);
                } else if (conn_same_as_last_v4(connp, sin) &&
                    ipsec_outbound_policy_current(ixa)) {
                        /* icmp_output_lastdst drops conn_lock */
                        error = icmp_output_lastdst(connp, mp, cr, pid, ixa);
                } else {
                        /* icmp_output_newdst drops conn_lock */
                        error = icmp_output_newdst(connp, mp, sin, NULL, cr,
                            pid, ixa);
                }
                ASSERT(MUTEX_NOT_HELD(&connp->conn_lock));
                if (is->is_sendto_ignerr)
                        return (0);
                else
                        return (error);
        default:
                return (EINVAL);
        }
}

sock_downcalls_t sock_rawip_downcalls = {
        rawip_activate,
        rawip_accept,
        rawip_bind,
        rawip_listen,
        rawip_connect,
        rawip_getpeername,
        rawip_getsockname,
        rawip_getsockopt,
        rawip_setsockopt,
        rawip_send,
        NULL,
        NULL,
        NULL,
        rawip_shutdown,
        rawip_clr_flowctrl,
        rawip_ioctl,
        rawip_close
};