9903 qinfo: add typed members

[unleashed.git] / usr / src / uts / common / inet / ipnet / ipnet.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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 * Copyright (c) 2016 by Delphix. All rights reserved.
 */

/*
 * Copyright (c) 2016, Joyent, Inc. All rights reserved.
 */

/*
 * The ipnet device defined here provides access to packets at the IP layer. To
 * provide access to packets at this layer it registers a callback function in
 * the ip module and when there are open instances of the device ip will pass
 * packets into the device. Packets from ip are passed on the input, output and
 * loopback paths. Internally the module returns to ip as soon as possible by
 * deferring processing using a taskq.
 *
 * Management of the devices in /dev/ipnet/ is handled by the devname
 * filesystem and use of the neti interfaces.  This module registers for NIC
 * events using the neti framework so that when IP interfaces are bought up,
 * taken down etc. the ipnet module is notified and its view of the interfaces
 * configured on the system adjusted.  On attach, the module gets an initial
 * view of the system again using the neti framework but as it has already
 * registered for IP interface events, it is still up-to-date with any changes.
 */

#include <sys/types.h>
#include <sys/conf.h>
#include <sys/cred.h>
#include <sys/stat.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/modctl.h>
#include <sys/dlpi.h>
#include <sys/strsun.h>
#include <sys/id_space.h>
#include <sys/kmem.h>
#include <sys/mkdev.h>
#include <sys/neti.h>
#include <net/if.h>
#include <sys/errno.h>
#include <sys/list.h>
#include <sys/ksynch.h>
#include <sys/hook_event.h>
#include <sys/sdt.h>
#include <sys/stropts.h>
#include <sys/sysmacros.h>
#include <inet/ip.h>
#include <inet/ip_if.h>
#include <inet/ip_multi.h>
#include <inet/ip6.h>
#include <inet/ipnet.h>
#include <net/bpf.h>
#include <net/bpfdesc.h>
#include <net/dlt.h>

static struct module_info ipnet_minfo = {
        1,              /* mi_idnum */
        "ipnet",        /* mi_idname */
        0,              /* mi_minpsz */
        INFPSZ,         /* mi_maxpsz */
        2048,           /* mi_hiwat */
        0               /* mi_lowat */
};

/*
 * List to hold static view of ipnetif_t's on the system. This is needed to
 * avoid holding the lock protecting the avl tree of ipnetif's over the
 * callback into the dev filesystem.
 */
typedef struct ipnetif_cbdata {
        char            ic_ifname[LIFNAMSIZ];
        dev_t           ic_dev;
        list_node_t     ic_next;
} ipnetif_cbdata_t;

/*
 * Convenience enumerated type for ipnet_accept().  It describes the
 * properties of a given ipnet_addrp_t relative to a single ipnet_t
 * client stream.  The values represent whether the address is ...
 */
typedef enum {
        IPNETADDR_MYADDR,       /* an address on my ipnetif_t. */
        IPNETADDR_MBCAST,       /* a multicast or broadcast address. */
        IPNETADDR_UNKNOWN       /* none of the above. */
} ipnet_addrtype_t;

/* Argument used for the ipnet_nicevent_taskq callback. */
typedef struct ipnet_nicevent_s {
        nic_event_t             ipne_event;
        net_handle_t            ipne_protocol;
        netstackid_t            ipne_stackid;
        uint64_t                ipne_ifindex;
        uint64_t                ipne_lifindex;
        char                    ipne_ifname[LIFNAMSIZ];
} ipnet_nicevent_t;

static dev_info_t       *ipnet_dip;
static major_t          ipnet_major;
static ddi_taskq_t      *ipnet_taskq;           /* taskq for packets */
static ddi_taskq_t      *ipnet_nicevent_taskq;  /* taskq for NIC events */
static id_space_t       *ipnet_minor_space;
static const int        IPNET_MINOR_LO = 1;     /* minor number for /dev/lo0 */
static const int        IPNET_MINOR_MIN = 2;    /* start of dynamic minors */
static dl_info_ack_t    ipnet_infoack = IPNET_INFO_ACK_INIT;
static ipnet_acceptfn_t ipnet_accept, ipnet_loaccept;
static bpf_itap_fn_t    ipnet_itap;

static void     ipnet_input(mblk_t *);
static int      ipnet_wput(queue_t *, mblk_t *);
static int      ipnet_rsrv(queue_t *);
static int      ipnet_open(queue_t *, dev_t *, int, int, cred_t *);
static int      ipnet_close(queue_t *, int, cred_t *);
static void     ipnet_ioctl(queue_t *, mblk_t *);
static void     ipnet_iocdata(queue_t *, mblk_t *);
static void     ipnet_wputnondata(queue_t *, mblk_t *);
static int      ipnet_attach(dev_info_t *, ddi_attach_cmd_t);
static int      ipnet_detach(dev_info_t *, ddi_detach_cmd_t);
static int      ipnet_devinfo(dev_info_t *, ddi_info_cmd_t, void *, void **);
static void     ipnet_inforeq(queue_t *q, mblk_t *mp);
static void     ipnet_bindreq(queue_t *q, mblk_t *mp);
static void     ipnet_unbindreq(queue_t *q, mblk_t *mp);
static void     ipnet_dlpromisconreq(queue_t *q, mblk_t *mp);
static void     ipnet_dlpromiscoffreq(queue_t *q, mblk_t *mp);
static int      ipnet_join_allmulti(ipnetif_t *, ipnet_stack_t *);
static void     ipnet_leave_allmulti(ipnetif_t *, ipnet_stack_t *);
static int      ipnet_nicevent_cb(hook_event_token_t, hook_data_t, void *);
static void     ipnet_nicevent_task(void *);
static ipnetif_t *ipnetif_create(const char *, uint64_t, ipnet_stack_t *,
    uint64_t);
static void     ipnetif_remove(ipnetif_t *, ipnet_stack_t *);
static ipnetif_addr_t *ipnet_match_lif(ipnetif_t *, lif_if_t, boolean_t);
static ipnetif_t *ipnetif_getby_index(uint64_t, ipnet_stack_t *);
static ipnetif_t *ipnetif_getby_dev(dev_t, ipnet_stack_t *);
static boolean_t ipnetif_in_zone(ipnetif_t *, zoneid_t, ipnet_stack_t *);
static void     ipnetif_zonecheck(ipnetif_t *, ipnet_stack_t *);
static int      ipnet_populate_if(net_handle_t, ipnet_stack_t *, boolean_t);
static int      ipnetif_compare_name(const void *, const void *);
static int      ipnetif_compare_name_zone(const void *, const void *);
static int      ipnetif_compare_index(const void *, const void *);
static void     ipnet_add_ifaddr(uint64_t, ipnetif_t *, net_handle_t);
static void     ipnet_delete_ifaddr(ipnetif_addr_t *, ipnetif_t *, boolean_t);
static void     ipnetif_refhold(ipnetif_t *);
static void     ipnetif_refrele(ipnetif_t *);
static void     ipnet_walkers_inc(ipnet_stack_t *);
static void     ipnet_walkers_dec(ipnet_stack_t *);
static void     ipnet_register_netihook(ipnet_stack_t *);
static void     *ipnet_stack_init(netstackid_t, netstack_t *);
static void     ipnet_stack_fini(netstackid_t, void *);
static void     ipnet_dispatch(void *);
static int      ipobs_bounce_func(hook_event_token_t, hook_data_t, void *);
static int      ipnet_bpf_bounce(hook_event_token_t, hook_data_t, void *);
static ipnetif_t *ipnetif_clone_create(ipnetif_t *, zoneid_t);
static void     ipnetif_clone_release(ipnetif_t *);

static struct qinit ipnet_rinit = {
        NULL,           /* qi_putp */
        ipnet_rsrv,     /* qi_srvp */
        ipnet_open,     /* qi_qopen */
        ipnet_close,    /* qi_qclose */
        NULL,           /* qi_qadmin */
        &ipnet_minfo,   /* qi_minfo */
};

static struct qinit ipnet_winit = {
        ipnet_wput,     /* qi_putp */
        NULL,           /* qi_srvp */
        NULL,           /* qi_qopen */
        NULL,           /* qi_qclose */
        NULL,           /* qi_qadmin */
        &ipnet_minfo,   /* qi_minfo */
};

static struct streamtab ipnet_info = {
        &ipnet_rinit, &ipnet_winit
};

DDI_DEFINE_STREAM_OPS(ipnet_ops, nulldev, nulldev, ipnet_attach,
    ipnet_detach, nodev, ipnet_devinfo, D_MP | D_MTPERMOD, &ipnet_info,
    ddi_quiesce_not_supported);

static struct modldrv modldrv = {
        &mod_driverops,
        "STREAMS ipnet driver",
        &ipnet_ops
};

static struct modlinkage modlinkage = {
        MODREV_1, &modldrv, NULL
};

/*
 * This structure contains the template data (names and type) that is
 * copied, in bulk, into the new kstats structure created by net_kstat_create.
 * No actual statistical information is stored in this instance of the
 * ipnet_kstats_t structure.
 */
static ipnet_kstats_t stats_template = {
        { "duplicationFail",    KSTAT_DATA_UINT64 },
        { "dispatchOk",         KSTAT_DATA_UINT64 },
        { "dispatchFail",       KSTAT_DATA_UINT64 },
        { "dispatchHeaderDrop", KSTAT_DATA_UINT64 },
        { "dispatchDupDrop",    KSTAT_DATA_UINT64 },
        { "dispatchDeliver",    KSTAT_DATA_UINT64 },
        { "acceptOk",           KSTAT_DATA_UINT64 },
        { "acceptFail",         KSTAT_DATA_UINT64 }
};

/*
 * Walk the list of physical interfaces on the machine, for each
 * interface create a new ipnetif_t and add any addresses to it. We
 * need to do the walk twice, once for IPv4 and once for IPv6.
 *
 * The interfaces are destroyed as part of ipnet_stack_fini() for each
 * stack.  Note that we cannot do this initialization in
 * ipnet_stack_init(), since ipnet_stack_init() cannot fail.
 */
static int
ipnetif_init(void)
{
        netstack_handle_t       nh;
        netstack_t              *ns;
        ipnet_stack_t           *ips;
        int                     ret = 0;

        netstack_next_init(&nh);
        while ((ns = netstack_next(&nh)) != NULL) {
                ips = ns->netstack_ipnet;
                if ((ret = ipnet_populate_if(ips->ips_ndv4, ips, B_FALSE)) == 0)
                        ret = ipnet_populate_if(ips->ips_ndv6, ips, B_TRUE);
                netstack_rele(ns);
                if (ret != 0)
                        break;
        }
        netstack_next_fini(&nh);
        return (ret);
}

/*
 * Standard module entry points.
 */
int
_init(void)
{
        int             ret;
        boolean_t       netstack_registered = B_FALSE;

        if ((ipnet_major = ddi_name_to_major("ipnet")) == (major_t)-1)
                return (ENODEV);
        ipnet_minor_space = id_space_create("ipnet_minor_space",
            IPNET_MINOR_MIN, MAXMIN32);

        /*
         * We call ddi_taskq_create() with nthread == 1 to ensure in-order
         * delivery of packets to clients.  Note that we need to create the
         * taskqs before calling netstack_register() since ipnet_stack_init()
         * registers callbacks that use 'em.
         */
        ipnet_taskq = ddi_taskq_create(NULL, "ipnet", 1, TASKQ_DEFAULTPRI, 0);
        ipnet_nicevent_taskq = ddi_taskq_create(NULL, "ipnet_nic_event_queue",
            1, TASKQ_DEFAULTPRI, 0);
        if (ipnet_taskq == NULL || ipnet_nicevent_taskq == NULL) {
                ret = ENOMEM;
                goto done;
        }

        netstack_register(NS_IPNET, ipnet_stack_init, NULL, ipnet_stack_fini);
        netstack_registered = B_TRUE;

        if ((ret = ipnetif_init()) == 0)
                ret = mod_install(&modlinkage);
done:
        if (ret != 0) {
                if (ipnet_taskq != NULL)
                        ddi_taskq_destroy(ipnet_taskq);
                if (ipnet_nicevent_taskq != NULL)
                        ddi_taskq_destroy(ipnet_nicevent_taskq);
                if (netstack_registered)
                        netstack_unregister(NS_IPNET);
                id_space_destroy(ipnet_minor_space);
        }
        return (ret);
}

int
_fini(void)
{
        int     err;

        if ((err = mod_remove(&modlinkage)) != 0)
                return (err);

        netstack_unregister(NS_IPNET);
        ddi_taskq_destroy(ipnet_nicevent_taskq);
        ddi_taskq_destroy(ipnet_taskq);
        id_space_destroy(ipnet_minor_space);
        return (0);
}

int
_info(struct modinfo *modinfop)
{
        return (mod_info(&modlinkage, modinfop));
}

static void
ipnet_register_netihook(ipnet_stack_t *ips)
{
        int             ret;
        zoneid_t        zoneid;
        netid_t         netid;

        HOOK_INIT(ips->ips_nicevents, ipnet_nicevent_cb, "ipnet_nicevents",
            ips);

        /*
         * It is possible for an exclusive stack to be in the process of
         * shutting down here, and the netid and protocol lookups could fail
         * in that case.
         */
        zoneid = netstackid_to_zoneid(ips->ips_netstack->netstack_stackid);
        if ((netid = net_zoneidtonetid(zoneid)) == -1)
                return;

        if ((ips->ips_ndv4 = net_protocol_lookup(netid, NHF_INET)) != NULL) {
                if ((ret = net_hook_register(ips->ips_ndv4, NH_NIC_EVENTS,
                    ips->ips_nicevents)) != 0) {
                        VERIFY(net_protocol_release(ips->ips_ndv4) == 0);
                        ips->ips_ndv4 = NULL;
                        cmn_err(CE_WARN, "unable to register IPv4 netinfo hooks"
                            " in zone %d: %d", zoneid, ret);
                }
        }
        if ((ips->ips_ndv6 = net_protocol_lookup(netid, NHF_INET6)) != NULL) {
                if ((ret = net_hook_register(ips->ips_ndv6, NH_NIC_EVENTS,
                    ips->ips_nicevents)) != 0) {
                        VERIFY(net_protocol_release(ips->ips_ndv6) == 0);
                        ips->ips_ndv6 = NULL;
                        cmn_err(CE_WARN, "unable to register IPv6 netinfo hooks"
                            " in zone %d: %d", zoneid, ret);
                }
        }

        /*
         * Create a local set of kstats for each zone.
         */
        ips->ips_kstatp = net_kstat_create(netid, "ipnet", 0, "ipnet_stats",
            "misc", KSTAT_TYPE_NAMED,
            sizeof (ipnet_kstats_t) / sizeof (kstat_named_t), 0);
        if (ips->ips_kstatp != NULL) {
                bcopy(&stats_template, &ips->ips_stats,
                    sizeof (ips->ips_stats));
                ips->ips_kstatp->ks_data = &ips->ips_stats;
                ips->ips_kstatp->ks_private =
                    (void *)(uintptr_t)ips->ips_netstack->netstack_stackid;
                kstat_install(ips->ips_kstatp);
        } else {
                cmn_err(CE_WARN, "net_kstat_create(%s,%s,%s) failed",
                    "ipnet", "ipnet_stats", "misc");
        }
}

/*
 * This function is called on attach to build an initial view of the
 * interfaces on the system. It will be called once for IPv4 and once
 * for IPv6, although there is only one ipnet interface for both IPv4
 * and IPv6 there are separate address lists.
 */
static int
ipnet_populate_if(net_handle_t nd, ipnet_stack_t *ips, boolean_t isv6)
{
        phy_if_t        phyif;
        lif_if_t        lif;
        ipnetif_t       *ipnetif;
        char            name[LIFNAMSIZ];
        boolean_t       new_if = B_FALSE;
        uint64_t        ifflags;
        int             ret = 0;

        /*
         * If ipnet_register_netihook() was unable to initialize this
         * stack's net_handle_t, then we cannot populate any interface
         * information.  This usually happens when we attempted to
         * grab a net_handle_t as a stack was shutting down.  We don't
         * want to fail the entire _init() operation because of a
         * stack shutdown (other stacks will continue to work just
         * fine), so we silently return success here.
         */
        if (nd == NULL)
                return (0);

        /*
         * Make sure we're not processing NIC events during the
         * population of our interfaces and address lists.
         */
        mutex_enter(&ips->ips_event_lock);

        for (phyif = net_phygetnext(nd, 0); phyif != 0;
            phyif = net_phygetnext(nd, phyif)) {
                if (net_getifname(nd, phyif, name, LIFNAMSIZ) != 0)
                        continue;
                ifflags =  0;
                (void) net_getlifflags(nd, phyif, 0, &ifflags);
                if ((ipnetif = ipnetif_getby_index(phyif, ips)) == NULL) {
                        ipnetif = ipnetif_create(name, phyif, ips, ifflags);
                        if (ipnetif == NULL) {
                                ret = ENOMEM;
                                goto done;
                        }
                        new_if = B_TRUE;
                }
                ipnetif->if_flags |=
                    isv6 ? IPNETIF_IPV6PLUMBED : IPNETIF_IPV4PLUMBED;

                for (lif = net_lifgetnext(nd, phyif, 0); lif != 0;
                    lif = net_lifgetnext(nd, phyif, lif)) {
                        /*
                         * Skip addresses that aren't up.  We'll add
                         * them when we receive an NE_LIF_UP event.
                         */
                        if (net_getlifflags(nd, phyif, lif, &ifflags) != 0 ||
                            !(ifflags & IFF_UP))
                                continue;
                        /* Don't add it if we already have it. */
                        if (ipnet_match_lif(ipnetif, lif, isv6) != NULL)
                                continue;
                        ipnet_add_ifaddr(lif, ipnetif, nd);
                }
                if (!new_if)
                        ipnetif_refrele(ipnetif);
        }

done:
        mutex_exit(&ips->ips_event_lock);
        return (ret);
}

static int
ipnet_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
{
        if (cmd != DDI_ATTACH)
                return (DDI_FAILURE);

        if (ddi_create_minor_node(dip, "lo0", S_IFCHR, IPNET_MINOR_LO,
            DDI_PSEUDO, 0) == DDI_FAILURE)
                return (DDI_FAILURE);

        ipnet_dip = dip;
        return (DDI_SUCCESS);
}

static int
ipnet_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
        if (cmd != DDI_DETACH)
                return (DDI_FAILURE);

        ASSERT(dip == ipnet_dip);
        ddi_remove_minor_node(ipnet_dip, NULL);
        ipnet_dip = NULL;
        return (DDI_SUCCESS);
}

/* ARGSUSED */
static int
ipnet_devinfo(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
{
        int     error = DDI_FAILURE;

        switch (infocmd) {
        case DDI_INFO_DEVT2INSTANCE:
                *result = (void *)0;
                error = DDI_SUCCESS;
                break;
        case DDI_INFO_DEVT2DEVINFO:
                if (ipnet_dip != NULL) {
                        *result = ipnet_dip;
                        error = DDI_SUCCESS;
                }
                break;
        }
        return (error);
}

/* ARGSUSED */
static int
ipnet_open(queue_t *rq, dev_t *dev, int oflag, int sflag, cred_t *crp)
{
        ipnet_t         *ipnet;
        netstack_t      *ns = NULL;
        ipnet_stack_t   *ips;
        int             err = 0;
        zoneid_t        zoneid = crgetzoneid(crp);

        /*
         * If the system is labeled, only the global zone is allowed to open
         * IP observability nodes.
         */
        if (is_system_labeled() && zoneid != GLOBAL_ZONEID)
                return (EACCES);

        /* We don't support open as a module */
        if (sflag & MODOPEN)
                return (ENOTSUP);

        /* This driver is self-cloning, we don't support re-open. */
        if (rq->q_ptr != NULL)
                return (EBUSY);

        if ((ipnet = kmem_zalloc(sizeof (*ipnet), KM_NOSLEEP)) == NULL)
                return (ENOMEM);

        VERIFY((ns = netstack_find_by_cred(crp)) != NULL);
        ips = ns->netstack_ipnet;

        rq->q_ptr = WR(rq)->q_ptr = ipnet;
        ipnet->ipnet_rq = rq;
        ipnet->ipnet_minor = (minor_t)id_alloc(ipnet_minor_space);
        ipnet->ipnet_zoneid = zoneid;
        ipnet->ipnet_dlstate = DL_UNBOUND;
        ipnet->ipnet_ns = ns;

        /*
         * We need to hold ips_event_lock here as any NE_LIF_DOWN events need
         * to be processed after ipnet_if is set and the ipnet_t has been
         * inserted in the ips_str_list.
         */
        mutex_enter(&ips->ips_event_lock);
        if (getminor(*dev) == IPNET_MINOR_LO) {
                ipnet->ipnet_flags |= IPNET_LOMODE;
                ipnet->ipnet_acceptfn = ipnet_loaccept;
        } else {
                ipnet->ipnet_acceptfn = ipnet_accept;
                ipnet->ipnet_if = ipnetif_getby_dev(*dev, ips);
                if (ipnet->ipnet_if == NULL ||
                    !ipnetif_in_zone(ipnet->ipnet_if, zoneid, ips)) {
                        err = ENODEV;
                        goto done;
                }
        }

        mutex_enter(&ips->ips_walkers_lock);
        while (ips->ips_walkers_cnt != 0)
                cv_wait(&ips->ips_walkers_cv, &ips->ips_walkers_lock);
        list_insert_head(&ips->ips_str_list, ipnet);
        *dev = makedevice(getmajor(*dev), ipnet->ipnet_minor);
        qprocson(rq);

        /*
         * Only register our callback if we're the first open client; we call
         * unregister in close() for the last open client.
         */
        if (list_head(&ips->ips_str_list) == list_tail(&ips->ips_str_list))
                ips->ips_hook = ipobs_register_hook(ns, ipnet_input);
        mutex_exit(&ips->ips_walkers_lock);

done:
        mutex_exit(&ips->ips_event_lock);
        if (err != 0) {
                netstack_rele(ns);
                id_free(ipnet_minor_space, ipnet->ipnet_minor);
                if (ipnet->ipnet_if != NULL)
                        ipnetif_refrele(ipnet->ipnet_if);
                kmem_free(ipnet, sizeof (*ipnet));
        }
        return (err);
}

/* ARGSUSED */
static int
ipnet_close(queue_t *rq, int flags __unused, cred_t *credp __unused)
{
        ipnet_t         *ipnet = rq->q_ptr;
        ipnet_stack_t   *ips = ipnet->ipnet_ns->netstack_ipnet;

        if (ipnet->ipnet_flags & IPNET_PROMISC_PHYS)
                ipnet_leave_allmulti(ipnet->ipnet_if, ips);
        if (ipnet->ipnet_flags & IPNET_PROMISC_MULTI)
                ipnet_leave_allmulti(ipnet->ipnet_if, ips);

        mutex_enter(&ips->ips_walkers_lock);
        while (ips->ips_walkers_cnt != 0)
                cv_wait(&ips->ips_walkers_cv, &ips->ips_walkers_lock);

        qprocsoff(rq);

        list_remove(&ips->ips_str_list, ipnet);
        if (ipnet->ipnet_if != NULL)
                ipnetif_refrele(ipnet->ipnet_if);
        id_free(ipnet_minor_space, ipnet->ipnet_minor);

        if (list_is_empty(&ips->ips_str_list)) {
                ipobs_unregister_hook(ips->ips_netstack, ips->ips_hook);
                ips->ips_hook = NULL;
        }

        kmem_free(ipnet, sizeof (*ipnet));

        mutex_exit(&ips->ips_walkers_lock);
        netstack_rele(ips->ips_netstack);
        return (0);
}

static int
ipnet_wput(queue_t *q, mblk_t *mp)
{
        switch (mp->b_datap->db_type) {
        case M_FLUSH:
                if (*mp->b_rptr & FLUSHW) {
                        flushq(q, FLUSHDATA);
                        *mp->b_rptr &= ~FLUSHW;
                }
                if (*mp->b_rptr & FLUSHR)
                        qreply(q, mp);
                else
                        freemsg(mp);
                break;
        case M_PROTO:
        case M_PCPROTO:
                ipnet_wputnondata(q, mp);
                break;
        case M_IOCTL:
                ipnet_ioctl(q, mp);
                break;
        case M_IOCDATA:
                ipnet_iocdata(q, mp);
                break;
        default:
                freemsg(mp);
                break;
        }
        return (0);
}

static int
ipnet_rsrv(queue_t *q)
{
        mblk_t  *mp;

        while ((mp = getq(q)) != NULL) {
                ASSERT(DB_TYPE(mp) == M_DATA);
                if (canputnext(q)) {
                        putnext(q, mp);
                } else {
                        (void) putbq(q, mp);
                        break;
                }
        }
        return (0);
}

static void
ipnet_ioctl(queue_t *q, mblk_t *mp)
{
        struct iocblk   *iocp = (struct iocblk *)mp->b_rptr;

        switch (iocp->ioc_cmd) {
        case DLIOCRAW:
                miocack(q, mp, 0, 0);
                break;
        case DLIOCIPNETINFO:
                if (iocp->ioc_count == TRANSPARENT) {
                        mcopyin(mp, NULL, sizeof (uint_t), NULL);
                        qreply(q, mp);
                        break;
                }
                /* We don't support I_STR with DLIOCIPNETINFO. */
                /* FALLTHROUGH */
        default:
                miocnak(q, mp, 0, EINVAL);
                break;
        }
}

static void
ipnet_iocdata(queue_t *q, mblk_t *mp)
{
        struct iocblk   *iocp = (struct iocblk *)mp->b_rptr;
        ipnet_t *ipnet = q->q_ptr;

        switch (iocp->ioc_cmd) {
        case DLIOCIPNETINFO:
                if (*(int *)mp->b_cont->b_rptr == 1)
                        ipnet->ipnet_flags |= IPNET_INFO;
                else if (*(int *)mp->b_cont->b_rptr == 0)
                        ipnet->ipnet_flags &= ~IPNET_INFO;
                else
                        goto iocnak;
                miocack(q, mp, 0, DL_IPNETINFO_VERSION);
                break;
        default:
iocnak:
                miocnak(q, mp, 0, EINVAL);
                break;
        }
}

static void
ipnet_wputnondata(queue_t *q, mblk_t *mp)
{
        union DL_primitives     *dlp = (union DL_primitives *)mp->b_rptr;
        t_uscalar_t             prim = dlp->dl_primitive;

        switch (prim) {
        case DL_INFO_REQ:
                ipnet_inforeq(q, mp);
                break;
        case DL_UNBIND_REQ:
                ipnet_unbindreq(q, mp);
                break;
        case DL_BIND_REQ:
                ipnet_bindreq(q, mp);
                break;
        case DL_PROMISCON_REQ:
                ipnet_dlpromisconreq(q, mp);
                break;
        case DL_PROMISCOFF_REQ:
                ipnet_dlpromiscoffreq(q, mp);
                break;
        case DL_UNITDATA_REQ:
        case DL_DETACH_REQ:
        case DL_PHYS_ADDR_REQ:
        case DL_SET_PHYS_ADDR_REQ:
        case DL_ENABMULTI_REQ:
        case DL_DISABMULTI_REQ:
        case DL_ATTACH_REQ:
                dlerrorack(q, mp, prim, DL_UNSUPPORTED, 0);
                break;
        default:
                dlerrorack(q, mp, prim, DL_BADPRIM, 0);
                break;
        }
}

static void
ipnet_inforeq(queue_t *q, mblk_t *mp)
{
        dl_info_ack_t   *dlip;
        size_t          size = sizeof (dl_info_ack_t) + sizeof (ushort_t);

        if (MBLKL(mp) < DL_INFO_REQ_SIZE) {
                dlerrorack(q, mp, DL_INFO_REQ, DL_BADPRIM, 0);
                return;
        }

        if ((mp = mexchange(q, mp, size, M_PCPROTO, DL_INFO_ACK)) == NULL)
                return;

        dlip = (dl_info_ack_t *)mp->b_rptr;
        *dlip = ipnet_infoack;
        qreply(q, mp);
}

static void
ipnet_bindreq(queue_t *q, mblk_t *mp)
{
        union DL_primitives     *dlp = (union DL_primitives *)mp->b_rptr;
        ipnet_t                 *ipnet = q->q_ptr;

        if (MBLKL(mp) < DL_BIND_REQ_SIZE) {
                dlerrorack(q, mp, DL_BIND_REQ, DL_BADPRIM, 0);
                return;
        }

        switch (dlp->bind_req.dl_sap) {
        case 0 :
                ipnet->ipnet_family = AF_UNSPEC;
                break;
        case IPV4_VERSION :
                ipnet->ipnet_family = AF_INET;
                break;
        case IPV6_VERSION :
                ipnet->ipnet_family = AF_INET6;
                break;
        default :
                dlerrorack(q, mp, DL_BIND_REQ, DL_BADSAP, 0);
                return;
                /*NOTREACHED*/
        }

        ipnet->ipnet_dlstate = DL_IDLE;
        dlbindack(q, mp, dlp->bind_req.dl_sap, 0, 0, 0, 0);
}

static void
ipnet_unbindreq(queue_t *q, mblk_t *mp)
{
        ipnet_t *ipnet = q->q_ptr;

        if (MBLKL(mp) < DL_UNBIND_REQ_SIZE) {
                dlerrorack(q, mp, DL_UNBIND_REQ, DL_BADPRIM, 0);
                return;
        }

        if (ipnet->ipnet_dlstate != DL_IDLE) {
                dlerrorack(q, mp, DL_UNBIND_REQ, DL_OUTSTATE, 0);
        } else {
                ipnet->ipnet_dlstate = DL_UNBOUND;
                ipnet->ipnet_family = AF_UNSPEC;
                dlokack(q, mp, DL_UNBIND_REQ);
        }
}

static void
ipnet_dlpromisconreq(queue_t *q, mblk_t *mp)
{
        ipnet_t         *ipnet = q->q_ptr;
        t_uscalar_t     level;
        int             err;

        if (MBLKL(mp) < DL_PROMISCON_REQ_SIZE) {
                dlerrorack(q, mp, DL_PROMISCON_REQ, DL_BADPRIM, 0);
                return;
        }

        if (ipnet->ipnet_flags & IPNET_LOMODE) {
                dlokack(q, mp, DL_PROMISCON_REQ);
                return;
        }

        level = ((dl_promiscon_req_t *)mp->b_rptr)->dl_level;
        if (level == DL_PROMISC_PHYS || level == DL_PROMISC_MULTI) {
                if ((err = ipnet_join_allmulti(ipnet->ipnet_if,
                    ipnet->ipnet_ns->netstack_ipnet)) != 0) {
                        dlerrorack(q, mp, DL_PROMISCON_REQ, DL_SYSERR, err);
                        return;
                }
        }

        switch (level) {
        case DL_PROMISC_PHYS:
                ipnet->ipnet_flags |= IPNET_PROMISC_PHYS;
                break;
        case DL_PROMISC_SAP:
                ipnet->ipnet_flags |= IPNET_PROMISC_SAP;
                break;
        case DL_PROMISC_MULTI:
                ipnet->ipnet_flags |= IPNET_PROMISC_MULTI;
                break;
        default:
                dlerrorack(q, mp, DL_PROMISCON_REQ, DL_BADPRIM, 0);
                return;
        }

        dlokack(q, mp, DL_PROMISCON_REQ);
}

static void
ipnet_dlpromiscoffreq(queue_t *q, mblk_t *mp)
{
        ipnet_t         *ipnet = q->q_ptr;
        t_uscalar_t     level;
        uint16_t        orig_ipnet_flags = ipnet->ipnet_flags;

        if (MBLKL(mp) < DL_PROMISCOFF_REQ_SIZE) {
                dlerrorack(q, mp, DL_PROMISCOFF_REQ, DL_BADPRIM, 0);
                return;
        }

        if (ipnet->ipnet_flags & IPNET_LOMODE) {
                dlokack(q, mp, DL_PROMISCOFF_REQ);
                return;
        }

        level = ((dl_promiscon_req_t *)mp->b_rptr)->dl_level;
        switch (level) {
        case DL_PROMISC_PHYS:
                if (ipnet->ipnet_flags & IPNET_PROMISC_PHYS)
                        ipnet->ipnet_flags &= ~IPNET_PROMISC_PHYS;
                break;
        case DL_PROMISC_SAP:
                if (ipnet->ipnet_flags & IPNET_PROMISC_SAP)
                        ipnet->ipnet_flags &= ~IPNET_PROMISC_SAP;
                break;
        case DL_PROMISC_MULTI:
                if (ipnet->ipnet_flags & IPNET_PROMISC_MULTI)
                        ipnet->ipnet_flags &= ~IPNET_PROMISC_MULTI;
                break;
        default:
                dlerrorack(q, mp, DL_PROMISCOFF_REQ, DL_BADPRIM, 0);
                return;
        }

        if (orig_ipnet_flags == ipnet->ipnet_flags) {
                dlerrorack(q, mp, DL_PROMISCOFF_REQ, DL_NOTENAB, 0);
                return;
        }

        if (level == DL_PROMISC_PHYS || level == DL_PROMISC_MULTI) {
                ipnet_leave_allmulti(ipnet->ipnet_if,
                    ipnet->ipnet_ns->netstack_ipnet);
        }

        dlokack(q, mp, DL_PROMISCOFF_REQ);
}

static int
ipnet_join_allmulti(ipnetif_t *ipnetif, ipnet_stack_t *ips)
{
        int             err = 0;
        ip_stack_t      *ipst = ips->ips_netstack->netstack_ip;
        uint64_t        index = ipnetif->if_index;

        mutex_enter(&ips->ips_event_lock);
        if (ipnetif->if_multicnt == 0) {
                ASSERT((ipnetif->if_flags &
                    (IPNETIF_IPV4ALLMULTI | IPNETIF_IPV6ALLMULTI)) == 0);
                if (ipnetif->if_flags & IPNETIF_IPV4PLUMBED) {
                        err = ip_join_allmulti(index, B_FALSE, ipst);
                        if (err != 0)
                                goto done;
                        ipnetif->if_flags |= IPNETIF_IPV4ALLMULTI;
                }
                if (ipnetif->if_flags & IPNETIF_IPV6PLUMBED) {
                        err = ip_join_allmulti(index, B_TRUE, ipst);
                        if (err != 0 &&
                            (ipnetif->if_flags & IPNETIF_IPV4ALLMULTI)) {
                                (void) ip_leave_allmulti(index, B_FALSE, ipst);
                                ipnetif->if_flags &= ~IPNETIF_IPV4ALLMULTI;
                                goto done;
                        }
                        ipnetif->if_flags |= IPNETIF_IPV6ALLMULTI;
                }
        }
        ipnetif->if_multicnt++;

done:
        mutex_exit(&ips->ips_event_lock);
        return (err);
}

static void
ipnet_leave_allmulti(ipnetif_t *ipnetif, ipnet_stack_t *ips)
{
        int             err;
        ip_stack_t      *ipst = ips->ips_netstack->netstack_ip;
        uint64_t        index = ipnetif->if_index;

        mutex_enter(&ips->ips_event_lock);
        ASSERT(ipnetif->if_multicnt != 0);
        if (--ipnetif->if_multicnt == 0) {
                if (ipnetif->if_flags & IPNETIF_IPV4ALLMULTI) {
                        err = ip_leave_allmulti(index, B_FALSE, ipst);
                        ASSERT(err == 0 || err == ENODEV);
                        ipnetif->if_flags &= ~IPNETIF_IPV4ALLMULTI;
                }
                if (ipnetif->if_flags & IPNETIF_IPV6ALLMULTI) {
                        err = ip_leave_allmulti(index, B_TRUE, ipst);
                        ASSERT(err == 0 || err == ENODEV);
                        ipnetif->if_flags &= ~IPNETIF_IPV6ALLMULTI;
                }
        }
        mutex_exit(&ips->ips_event_lock);
}

/*
 * Allocate a new mblk_t and put a dl_ipnetinfo_t in it.
 * The structure it copies the header information from,
 * hook_pkt_observe_t, is constructed using network byte
 * order in ipobs_hook(), so there is no conversion here.
 */
static mblk_t *
ipnet_addheader(hook_pkt_observe_t *hdr, mblk_t *mp)
{
        mblk_t          *dlhdr;
        dl_ipnetinfo_t  *dl;

        if ((dlhdr = allocb(sizeof (dl_ipnetinfo_t), BPRI_HI)) == NULL) {
                freemsg(mp);
                return (NULL);
        }
        dl = (dl_ipnetinfo_t *)dlhdr->b_rptr;
        dl->dli_version = DL_IPNETINFO_VERSION;
        dl->dli_family = hdr->hpo_family;
        dl->dli_htype = hdr->hpo_htype;
        dl->dli_pktlen = hdr->hpo_pktlen;
        dl->dli_ifindex = hdr->hpo_ifindex;
        dl->dli_grifindex = hdr->hpo_grifindex;
        dl->dli_zsrc = hdr->hpo_zsrc;
        dl->dli_zdst = hdr->hpo_zdst;
        dlhdr->b_wptr += sizeof (*dl);
        dlhdr->b_cont = mp;

        return (dlhdr);
}

static ipnet_addrtype_t
ipnet_get_addrtype(ipnet_t *ipnet, ipnet_addrp_t *addr)
{
        list_t                  *list;
        ipnetif_t               *ipnetif = ipnet->ipnet_if;
        ipnetif_addr_t          *ifaddr;
        ipnet_addrtype_t        addrtype = IPNETADDR_UNKNOWN;

        /* First check if the address is multicast or limited broadcast. */
        switch (addr->iap_family) {
        case AF_INET:
                if (CLASSD(*(addr->iap_addr4)) ||
                    *(addr->iap_addr4) == INADDR_BROADCAST)
                        return (IPNETADDR_MBCAST);
                break;
        case AF_INET6:
                if (IN6_IS_ADDR_MULTICAST(addr->iap_addr6))
                        return (IPNETADDR_MBCAST);
                break;
        }

        /*
         * Walk the address list to see if the address belongs to our
         * interface or is one of our subnet broadcast addresses.
         */
        mutex_enter(&ipnetif->if_addr_lock);
        list = (addr->iap_family == AF_INET) ?
            &ipnetif->if_ip4addr_list : &ipnetif->if_ip6addr_list;
        for (ifaddr = list_head(list);
            ifaddr != NULL && addrtype == IPNETADDR_UNKNOWN;
            ifaddr = list_next(list, ifaddr)) {
                /*
                 * If we're not in the global zone, then only look at
                 * addresses in our zone.
                 */
                if (ipnet->ipnet_zoneid != GLOBAL_ZONEID &&
                    ipnet->ipnet_zoneid != ifaddr->ifa_zone)
                        continue;
                switch (addr->iap_family) {
                case AF_INET:
                        if (ifaddr->ifa_ip4addr != INADDR_ANY &&
                            *(addr->iap_addr4) == ifaddr->ifa_ip4addr)
                                addrtype = IPNETADDR_MYADDR;
                        else if (ifaddr->ifa_brdaddr != INADDR_ANY &&
                            *(addr->iap_addr4) == ifaddr->ifa_brdaddr)
                                addrtype = IPNETADDR_MBCAST;
                        break;
                case AF_INET6:
                        if (IN6_ARE_ADDR_EQUAL(addr->iap_addr6,
                            &ifaddr->ifa_ip6addr))
                                addrtype = IPNETADDR_MYADDR;
                        break;
                }
        }
        mutex_exit(&ipnetif->if_addr_lock);

        return (addrtype);
}

/*
 * Verify if the packet contained in hdr should be passed up to the
 * ipnet client stream.
 */
static boolean_t
ipnet_accept(ipnet_t *ipnet, hook_pkt_observe_t *hdr, ipnet_addrp_t *src,
    ipnet_addrp_t *dst)
{
        boolean_t               obsif;
        uint64_t                ifindex = ipnet->ipnet_if->if_index;
        ipnet_addrtype_t        srctype;
        ipnet_addrtype_t        dsttype;

        srctype = ipnet_get_addrtype(ipnet, src);
        dsttype = ipnet_get_addrtype(ipnet, dst);

        /*
         * If the packet's ifindex matches ours, or the packet's group ifindex
         * matches ours, it's on the interface we're observing.  (Thus,
         * observing on the group ifindex matches all ifindexes in the group.)
         */
        obsif = (ntohl(hdr->hpo_ifindex) == ifindex ||
            ntohl(hdr->hpo_grifindex) == ifindex);

        DTRACE_PROBE5(ipnet_accept__addr,
            ipnet_addrtype_t, srctype, ipnet_addrp_t *, src,
            ipnet_addrtype_t, dsttype, ipnet_addrp_t *, dst,
            boolean_t, obsif);

        /*
         * Do not allow an ipnet stream to see packets that are not from or to
         * its zone.  The exception is when zones are using the shared stack
         * model.  In this case, streams in the global zone have visibility
         * into other shared-stack zones, and broadcast and multicast traffic
         * is visible by all zones in the stack.
         */
        if (ipnet->ipnet_zoneid != GLOBAL_ZONEID &&
            dsttype != IPNETADDR_MBCAST) {
                if (ipnet->ipnet_zoneid != ntohl(hdr->hpo_zsrc) &&
                    ipnet->ipnet_zoneid != ntohl(hdr->hpo_zdst))
                        return (B_FALSE);
        }

        /*
         * If DL_PROMISC_SAP isn't enabled, then the bound SAP must match the
         * packet's IP version.
         */
        if (!(ipnet->ipnet_flags & IPNET_PROMISC_SAP) &&
            ipnet->ipnet_family != hdr->hpo_family)
                return (B_FALSE);

        /* If the destination address is ours, then accept the packet. */
        if (dsttype == IPNETADDR_MYADDR)
                return (B_TRUE);

        /*
         * If DL_PROMISC_PHYS is enabled, then we can see all packets that are
         * sent or received on the interface we're observing, or packets that
         * have our source address (this allows us to see packets we send).
         */
        if (ipnet->ipnet_flags & IPNET_PROMISC_PHYS) {
                if (srctype == IPNETADDR_MYADDR || obsif)
                        return (B_TRUE);
        }

        /*
         * We accept multicast and broadcast packets transmitted or received
         * on the interface we're observing.
         */
        if (dsttype == IPNETADDR_MBCAST && obsif)
                return (B_TRUE);

        return (B_FALSE);
}

/*
 * Verify if the packet contained in hdr should be passed up to the ipnet
 * client stream that's in IPNET_LOMODE.
 */
/* ARGSUSED */
static boolean_t
ipnet_loaccept(ipnet_t *ipnet, hook_pkt_observe_t *hdr, ipnet_addrp_t *src,
    ipnet_addrp_t *dst)
{
        if (hdr->hpo_htype != htons(IPOBS_HOOK_LOCAL)) {
                /*
                 * ipnet_if is only NULL for IPNET_MINOR_LO devices.
                 */
                if (ipnet->ipnet_if == NULL)
                        return (B_FALSE);
        }

        /*
         * An ipnet stream must not see packets that are not from/to its zone.
         */
        if (ipnet->ipnet_zoneid != GLOBAL_ZONEID) {
                if (ipnet->ipnet_zoneid != ntohl(hdr->hpo_zsrc) &&
                    ipnet->ipnet_zoneid != ntohl(hdr->hpo_zdst))
                        return (B_FALSE);
        }

        return (ipnet->ipnet_family == AF_UNSPEC ||
            ipnet->ipnet_family == hdr->hpo_family);
}

static void
ipnet_dispatch(void *arg)
{
        mblk_t                  *mp = arg;
        hook_pkt_observe_t      *hdr = (hook_pkt_observe_t *)mp->b_rptr;
        ipnet_t                 *ipnet;
        mblk_t                  *netmp;
        list_t                  *list;
        ipnet_stack_t           *ips;
        ipnet_addrp_t           src;
        ipnet_addrp_t           dst;

        ips = ((netstack_t *)hdr->hpo_ctx)->netstack_ipnet;

        netmp = hdr->hpo_pkt->b_cont;
        src.iap_family = hdr->hpo_family;
        dst.iap_family = hdr->hpo_family;

        if (hdr->hpo_family == AF_INET) {
                src.iap_addr4 = &((ipha_t *)(netmp->b_rptr))->ipha_src;
                dst.iap_addr4 = &((ipha_t *)(netmp->b_rptr))->ipha_dst;
        } else {
                src.iap_addr6 = &((ip6_t *)(netmp->b_rptr))->ip6_src;
                dst.iap_addr6 = &((ip6_t *)(netmp->b_rptr))->ip6_dst;
        }

        ipnet_walkers_inc(ips);

        list = &ips->ips_str_list;
        for (ipnet = list_head(list); ipnet != NULL;
            ipnet = list_next(list, ipnet)) {
                if (!(*ipnet->ipnet_acceptfn)(ipnet, hdr, &src, &dst)) {
                        IPSK_BUMP(ips, ik_acceptFail);
                        continue;
                }
                IPSK_BUMP(ips, ik_acceptOk);

                if (list_next(list, ipnet) == NULL) {
                        netmp = hdr->hpo_pkt->b_cont;
                        hdr->hpo_pkt->b_cont = NULL;
                } else {
                        if ((netmp = dupmsg(hdr->hpo_pkt->b_cont)) == NULL &&
                            (netmp = copymsg(hdr->hpo_pkt->b_cont)) == NULL) {
                                IPSK_BUMP(ips, ik_duplicationFail);
                                continue;
                        }
                }

                if (ipnet->ipnet_flags & IPNET_INFO) {
                        if ((netmp = ipnet_addheader(hdr, netmp)) == NULL) {
                                IPSK_BUMP(ips, ik_dispatchHeaderDrop);
                                continue;
                        }
                }

                if (ipnet->ipnet_rq->q_first == NULL &&
                    canputnext(ipnet->ipnet_rq)) {
                        putnext(ipnet->ipnet_rq, netmp);
                        IPSK_BUMP(ips, ik_dispatchDeliver);
                } else if (canput(ipnet->ipnet_rq)) {
                        (void) putq(ipnet->ipnet_rq, netmp);
                        IPSK_BUMP(ips, ik_dispatchDeliver);
                } else {
                        freemsg(netmp);
                        IPSK_BUMP(ips, ik_dispatchPutDrop);
                }
        }

        ipnet_walkers_dec(ips);

        freemsg(mp);
}

static void
ipnet_input(mblk_t *mp)
{
        hook_pkt_observe_t      *hdr = (hook_pkt_observe_t *)mp->b_rptr;
        ipnet_stack_t           *ips;

        ips = ((netstack_t *)hdr->hpo_ctx)->netstack_ipnet;

        if (ddi_taskq_dispatch(ipnet_taskq, ipnet_dispatch, mp, DDI_NOSLEEP) !=
            DDI_SUCCESS) {
                IPSK_BUMP(ips, ik_dispatchFail);
                freemsg(mp);
        } else {
                IPSK_BUMP(ips, ik_dispatchOk);
        }
}

static ipnetif_t *
ipnet_alloc_if(ipnet_stack_t *ips)
{
        ipnetif_t       *ipnetif;

        if ((ipnetif = kmem_zalloc(sizeof (*ipnetif), KM_NOSLEEP)) == NULL)
                return (NULL);

        mutex_init(&ipnetif->if_addr_lock, NULL, MUTEX_DEFAULT, 0);
        list_create(&ipnetif->if_ip4addr_list, sizeof (ipnetif_addr_t),
            offsetof(ipnetif_addr_t, ifa_link));
        list_create(&ipnetif->if_ip6addr_list, sizeof (ipnetif_addr_t),
            offsetof(ipnetif_addr_t, ifa_link));
        mutex_init(&ipnetif->if_reflock, NULL, MUTEX_DEFAULT, 0);

        ipnetif->if_stackp = ips;

        return (ipnetif);
}

/*
 * Create a new ipnetif_t and new minor node for it.  If creation is
 * successful the new ipnetif_t is inserted into an avl_tree
 * containing ipnetif's for this stack instance.
 */
static ipnetif_t *
ipnetif_create(const char *name, uint64_t index, ipnet_stack_t *ips,
    uint64_t ifflags)
{
        ipnetif_t       *ipnetif;
        avl_index_t     where = 0;
        minor_t         ifminor;

        /*
         * Because ipnetif_create() can be called from a NIC event
         * callback, it should not block.
         */
        ifminor = (minor_t)id_alloc_nosleep(ipnet_minor_space);
        if (ifminor == (minor_t)-1)
                return (NULL);
        if ((ipnetif = ipnet_alloc_if(ips)) == NULL) {
                id_free(ipnet_minor_space, ifminor);
                return (NULL);
        }

        (void) strlcpy(ipnetif->if_name, name, LIFNAMSIZ);
        ipnetif->if_index = (uint_t)index;
        ipnetif->if_zoneid = netstack_get_zoneid(ips->ips_netstack);
        ipnetif->if_dev = makedevice(ipnet_major, ifminor);

        ipnetif->if_refcnt = 1;
        if ((ifflags & IFF_LOOPBACK) != 0)
                ipnetif->if_flags = IPNETIF_LOOPBACK;

        mutex_enter(&ips->ips_avl_lock);
        VERIFY(avl_find(&ips->ips_avl_by_index, &index, &where) == NULL);
        avl_insert(&ips->ips_avl_by_index, ipnetif, where);
        VERIFY(avl_find(&ips->ips_avl_by_name, (void *)name, &where) == NULL);
        avl_insert(&ips->ips_avl_by_name, ipnetif, where);
        mutex_exit(&ips->ips_avl_lock);

        return (ipnetif);
}

static void
ipnetif_remove(ipnetif_t *ipnetif, ipnet_stack_t *ips)
{
        ipnet_t *ipnet;

        ipnet_walkers_inc(ips);
        /* Send a SIGHUP to all open streams associated with this ipnetif. */
        for (ipnet = list_head(&ips->ips_str_list); ipnet != NULL;
            ipnet = list_next(&ips->ips_str_list, ipnet)) {
                if (ipnet->ipnet_if == ipnetif)
                        (void) putnextctl(ipnet->ipnet_rq, M_HANGUP);
        }
        ipnet_walkers_dec(ips);
        mutex_enter(&ips->ips_avl_lock);
        avl_remove(&ips->ips_avl_by_index, ipnetif);
        avl_remove(&ips->ips_avl_by_name, ipnetif);
        mutex_exit(&ips->ips_avl_lock);
        /*
         * Release the reference we implicitly held in ipnetif_create().
         */
        ipnetif_refrele(ipnetif);
}

static void
ipnet_purge_addrlist(list_t *addrlist)
{
        ipnetif_addr_t  *ifa;

        while ((ifa = list_head(addrlist)) != NULL) {
                list_remove(addrlist, ifa);
                if (ifa->ifa_shared != NULL)
                        ipnetif_clone_release(ifa->ifa_shared);
                kmem_free(ifa, sizeof (*ifa));
        }
}

static void
ipnetif_free(ipnetif_t *ipnetif)
{
        ASSERT(ipnetif->if_refcnt == 0);
        ASSERT(ipnetif->if_sharecnt == 0);

        /* Remove IPv4/v6 address lists from the ipnetif */
        ipnet_purge_addrlist(&ipnetif->if_ip4addr_list);
        list_destroy(&ipnetif->if_ip4addr_list);
        ipnet_purge_addrlist(&ipnetif->if_ip6addr_list);
        list_destroy(&ipnetif->if_ip6addr_list);
        mutex_destroy(&ipnetif->if_addr_lock);
        mutex_destroy(&ipnetif->if_reflock);
        if (ipnetif->if_dev != 0)
                id_free(ipnet_minor_space, getminor(ipnetif->if_dev));
        kmem_free(ipnetif, sizeof (*ipnetif));
}

/*
 * Create an ipnetif_addr_t with the given logical interface id (lif)
 * and add it to the supplied ipnetif.  The lif is the netinfo
 * representation of logical interface id, and we use this id to match
 * incoming netinfo events against our lists of addresses.
 */
static void
ipnet_add_ifaddr(uint64_t lif, ipnetif_t *ipnetif, net_handle_t nd)
{
        ipnetif_addr_t          *ifaddr;
        zoneid_t                zoneid;
        struct sockaddr_in      bcast;
        struct sockaddr_storage addr;
        net_ifaddr_t            type = NA_ADDRESS;
        uint64_t                phyif = ipnetif->if_index;

        if (net_getlifaddr(nd, phyif, lif, 1, &type, &addr) != 0 ||
            net_getlifzone(nd, phyif, lif, &zoneid) != 0)
                return;

        if ((ifaddr = kmem_alloc(sizeof (*ifaddr), KM_NOSLEEP)) == NULL)
                return;
        ifaddr->ifa_zone = zoneid;
        ifaddr->ifa_id = lif;
        ifaddr->ifa_shared = NULL;

        switch (addr.ss_family) {
        case AF_INET:
                ifaddr->ifa_ip4addr =
                    ((struct sockaddr_in *)&addr)->sin_addr.s_addr;
                /*
                 * Try and get the broadcast address.  Note that it's okay for
                 * an interface to not have a broadcast address, so we don't
                 * fail the entire operation if net_getlifaddr() fails here.
                 */
                type = NA_BROADCAST;
                if (net_getlifaddr(nd, phyif, lif, 1, &type, &bcast) == 0)
                        ifaddr->ifa_brdaddr = bcast.sin_addr.s_addr;
                break;
        case AF_INET6:
                ifaddr->ifa_ip6addr = ((struct sockaddr_in6 *)&addr)->sin6_addr;
                break;
        }

        /*
         * The zoneid stored in ipnetif_t needs to correspond to the actual
         * zone the address is being used in. This facilitates finding the
         * correct netstack_t pointer, amongst other things, later.
         */
        if (zoneid == ALL_ZONES)
                zoneid = GLOBAL_ZONEID;

        mutex_enter(&ipnetif->if_addr_lock);
        if (zoneid != ipnetif->if_zoneid) {
                ipnetif_t *ifp2;

                ifp2 = ipnetif_clone_create(ipnetif, zoneid);
                ifaddr->ifa_shared = ifp2;
        }
        list_insert_tail(addr.ss_family == AF_INET ?
            &ipnetif->if_ip4addr_list : &ipnetif->if_ip6addr_list, ifaddr);
        mutex_exit(&ipnetif->if_addr_lock);
}

static void
ipnet_delete_ifaddr(ipnetif_addr_t *ifaddr, ipnetif_t *ipnetif, boolean_t isv6)
{
        mutex_enter(&ipnetif->if_addr_lock);
        if (ifaddr->ifa_shared != NULL)
                ipnetif_clone_release(ifaddr->ifa_shared);

        list_remove(isv6 ?
            &ipnetif->if_ip6addr_list : &ipnetif->if_ip4addr_list, ifaddr);
        mutex_exit(&ipnetif->if_addr_lock);
        kmem_free(ifaddr, sizeof (*ifaddr));
}

static void
ipnet_plumb_ev(ipnet_nicevent_t *ipne, ipnet_stack_t *ips, boolean_t isv6)
{
        ipnetif_t       *ipnetif;
        boolean_t       refrele_needed = B_TRUE;
        uint64_t        ifflags;
        uint64_t        ifindex;
        char            *ifname;

        ifflags = 0;
        ifname = ipne->ipne_ifname;
        ifindex = ipne->ipne_ifindex;

        (void) net_getlifflags(ipne->ipne_protocol, ifindex, 0, &ifflags);

        if ((ipnetif = ipnetif_getby_index(ifindex, ips)) == NULL) {
                ipnetif = ipnetif_create(ifname, ifindex, ips, ifflags);
                refrele_needed = B_FALSE;
        }
        if (ipnetif != NULL) {
                ipnetif->if_flags |=
                    isv6 ? IPNETIF_IPV6PLUMBED : IPNETIF_IPV4PLUMBED;
        }

        if (ipnetif->if_multicnt != 0) {
                if (ip_join_allmulti(ifindex, isv6,
                    ips->ips_netstack->netstack_ip) == 0) {
                        ipnetif->if_flags |=
                            isv6 ? IPNETIF_IPV6ALLMULTI : IPNETIF_IPV4ALLMULTI;
                }
        }

        if (refrele_needed)
                ipnetif_refrele(ipnetif);
}

static void
ipnet_unplumb_ev(uint64_t ifindex, ipnet_stack_t *ips, boolean_t isv6)
{
        ipnetif_t       *ipnetif;

        if ((ipnetif = ipnetif_getby_index(ifindex, ips)) == NULL)
                return;

        mutex_enter(&ipnetif->if_addr_lock);
        ipnet_purge_addrlist(isv6 ?
            &ipnetif->if_ip6addr_list : &ipnetif->if_ip4addr_list);
        mutex_exit(&ipnetif->if_addr_lock);

        /*
         * Note that we have one ipnetif for both IPv4 and IPv6, but we receive
         * separate NE_UNPLUMB events for IPv4 and IPv6.  We remove the ipnetif
         * if both IPv4 and IPv6 interfaces have been unplumbed.
         */
        ipnetif->if_flags &= isv6 ? ~IPNETIF_IPV6PLUMBED : ~IPNETIF_IPV4PLUMBED;
        if (!(ipnetif->if_flags & (IPNETIF_IPV4PLUMBED | IPNETIF_IPV6PLUMBED)))
                ipnetif_remove(ipnetif, ips);
        ipnetif_refrele(ipnetif);
}

static void
ipnet_lifup_ev(uint64_t ifindex, uint64_t lifindex, net_handle_t nd,
    ipnet_stack_t *ips, boolean_t isv6)
{
        ipnetif_t       *ipnetif;
        ipnetif_addr_t  *ifaddr;

        if ((ipnetif = ipnetif_getby_index(ifindex, ips)) == NULL)
                return;
        if ((ifaddr = ipnet_match_lif(ipnetif, lifindex, isv6)) != NULL) {
                /*
                 * We must have missed a NE_LIF_DOWN event.  Delete this
                 * ifaddr and re-create it.
                 */
                ipnet_delete_ifaddr(ifaddr, ipnetif, isv6);
        }

        ipnet_add_ifaddr(lifindex, ipnetif, nd);
        ipnetif_refrele(ipnetif);
}

static void
ipnet_lifdown_ev(uint64_t ifindex, uint64_t lifindex, ipnet_stack_t *ips,
    boolean_t isv6)
{
        ipnetif_t       *ipnetif;
        ipnetif_addr_t  *ifaddr;

        if ((ipnetif = ipnetif_getby_index(ifindex, ips)) == NULL)
                return;
        if ((ifaddr = ipnet_match_lif(ipnetif, lifindex, isv6)) != NULL)
                ipnet_delete_ifaddr(ifaddr, ipnetif, isv6);
        ipnetif_refrele(ipnetif);
        /*
         * Make sure that open streams on this ipnetif are still allowed to
         * have it open.
         */
        ipnetif_zonecheck(ipnetif, ips);
}

/*
 * This callback from the NIC event framework dispatches a taskq as the event
 * handlers may block.
 */
/* ARGSUSED */
static int
ipnet_nicevent_cb(hook_event_token_t token, hook_data_t info, void *arg)
{
        ipnet_stack_t           *ips = arg;
        hook_nic_event_t        *hn = (hook_nic_event_t *)info;
        ipnet_nicevent_t        *ipne;

        if ((ipne = kmem_alloc(sizeof (ipnet_nicevent_t), KM_NOSLEEP)) == NULL)
                return (0);
        ipne->ipne_event = hn->hne_event;
        ipne->ipne_protocol = hn->hne_protocol;
        ipne->ipne_stackid = ips->ips_netstack->netstack_stackid;
        ipne->ipne_ifindex = hn->hne_nic;
        ipne->ipne_lifindex = hn->hne_lif;
        if (hn->hne_datalen != 0) {
                (void) strlcpy(ipne->ipne_ifname, hn->hne_data,
                    sizeof (ipne->ipne_ifname));
        }
        (void) ddi_taskq_dispatch(ipnet_nicevent_taskq, ipnet_nicevent_task,
            ipne, DDI_NOSLEEP);
        return (0);
}

static void
ipnet_nicevent_task(void *arg)
{
        ipnet_nicevent_t        *ipne = arg;
        netstack_t              *ns;
        ipnet_stack_t           *ips;
        boolean_t               isv6;

        if ((ns = netstack_find_by_stackid(ipne->ipne_stackid)) == NULL)
                goto done;
        ips = ns->netstack_ipnet;
        isv6 = (ipne->ipne_protocol == ips->ips_ndv6);

        mutex_enter(&ips->ips_event_lock);
        switch (ipne->ipne_event) {
        case NE_PLUMB:
                ipnet_plumb_ev(ipne, ips, isv6);
                break;
        case NE_UNPLUMB:
                ipnet_unplumb_ev(ipne->ipne_ifindex, ips, isv6);
                break;
        case NE_LIF_UP:
                ipnet_lifup_ev(ipne->ipne_ifindex, ipne->ipne_lifindex,
                    ipne->ipne_protocol, ips, isv6);
                break;
        case NE_LIF_DOWN:
                ipnet_lifdown_ev(ipne->ipne_ifindex, ipne->ipne_lifindex, ips,
                    isv6);
                break;
        default:
                break;
        }
        mutex_exit(&ips->ips_event_lock);
done:
        if (ns != NULL)
                netstack_rele(ns);
        kmem_free(ipne, sizeof (ipnet_nicevent_t));
}

dev_t
ipnet_if_getdev(char *name, zoneid_t zoneid)
{
        netstack_t      *ns;
        ipnet_stack_t   *ips;
        ipnetif_t       *ipnetif;
        dev_t           dev = (dev_t)-1;

        if (is_system_labeled() && zoneid != GLOBAL_ZONEID)
                return (dev);
        if ((ns = netstack_find_by_zoneid(zoneid)) == NULL)
                return (dev);

        ips = ns->netstack_ipnet;
        mutex_enter(&ips->ips_avl_lock);
        if ((ipnetif = avl_find(&ips->ips_avl_by_name, name, NULL)) != NULL) {
                if (ipnetif_in_zone(ipnetif, zoneid, ips))
                        dev = ipnetif->if_dev;
        }
        mutex_exit(&ips->ips_avl_lock);
        netstack_rele(ns);

        return (dev);
}

static ipnetif_t *
ipnetif_getby_index(uint64_t id, ipnet_stack_t *ips)
{
        ipnetif_t       *ipnetif;

        mutex_enter(&ips->ips_avl_lock);
        if ((ipnetif = avl_find(&ips->ips_avl_by_index, &id, NULL)) != NULL)
                ipnetif_refhold(ipnetif);
        mutex_exit(&ips->ips_avl_lock);
        return (ipnetif);
}

static ipnetif_t *
ipnetif_getby_dev(dev_t dev, ipnet_stack_t *ips)
{
        ipnetif_t       *ipnetif;
        avl_tree_t      *tree;

        mutex_enter(&ips->ips_avl_lock);
        tree = &ips->ips_avl_by_index;
        for (ipnetif = avl_first(tree); ipnetif != NULL;
            ipnetif = avl_walk(tree, ipnetif, AVL_AFTER)) {
                if (ipnetif->if_dev == dev) {
                        ipnetif_refhold(ipnetif);
                        break;
                }
        }
        mutex_exit(&ips->ips_avl_lock);
        return (ipnetif);
}

static ipnetif_addr_t *
ipnet_match_lif(ipnetif_t *ipnetif, lif_if_t lid, boolean_t isv6)
{
        ipnetif_addr_t  *ifaddr;
        list_t  *list;

        mutex_enter(&ipnetif->if_addr_lock);
        list = isv6 ? &ipnetif->if_ip6addr_list : &ipnetif->if_ip4addr_list;
        for (ifaddr = list_head(list); ifaddr != NULL;
            ifaddr = list_next(list, ifaddr)) {
                if (lid == ifaddr->ifa_id)
                        break;
        }
        mutex_exit(&ipnetif->if_addr_lock);
        return (ifaddr);
}

/* ARGSUSED */
static void *
ipnet_stack_init(netstackid_t stackid, netstack_t *ns)
{
        ipnet_stack_t   *ips;

        ips = kmem_zalloc(sizeof (*ips), KM_SLEEP);
        ips->ips_netstack = ns;
        mutex_init(&ips->ips_avl_lock, NULL, MUTEX_DEFAULT, 0);
        avl_create(&ips->ips_avl_by_index, ipnetif_compare_index,
            sizeof (ipnetif_t), offsetof(ipnetif_t, if_avl_by_index));
        avl_create(&ips->ips_avl_by_name, ipnetif_compare_name,
            sizeof (ipnetif_t), offsetof(ipnetif_t, if_avl_by_name));
        avl_create(&ips->ips_avl_by_shared, ipnetif_compare_name_zone,
            sizeof (ipnetif_t), offsetof(ipnetif_t, if_avl_by_shared));
        mutex_init(&ips->ips_walkers_lock, NULL, MUTEX_DEFAULT, NULL);
        cv_init(&ips->ips_walkers_cv, NULL, CV_DRIVER, NULL);
        list_create(&ips->ips_str_list, sizeof (ipnet_t),
            offsetof(ipnet_t, ipnet_next));
        ipnet_register_netihook(ips);
        return (ips);
}

/* ARGSUSED */
static void
ipnet_stack_fini(netstackid_t stackid, void *arg)
{
        ipnet_stack_t   *ips = arg;
        ipnetif_t       *ipnetif, *nipnetif;

        if (ips->ips_kstatp != NULL) {
                zoneid_t zoneid;

                zoneid = netstackid_to_zoneid(stackid);
                net_kstat_delete(net_zoneidtonetid(zoneid), ips->ips_kstatp);
        }
        if (ips->ips_ndv4 != NULL) {
                VERIFY(net_hook_unregister(ips->ips_ndv4, NH_NIC_EVENTS,
                    ips->ips_nicevents) == 0);
                VERIFY(net_protocol_release(ips->ips_ndv4) == 0);
        }
        if (ips->ips_ndv6 != NULL) {
                VERIFY(net_hook_unregister(ips->ips_ndv6, NH_NIC_EVENTS,
                    ips->ips_nicevents) == 0);
                VERIFY(net_protocol_release(ips->ips_ndv6) == 0);
        }
        hook_free(ips->ips_nicevents);

        for (ipnetif = avl_first(&ips->ips_avl_by_index); ipnetif != NULL;
            ipnetif = nipnetif) {
                nipnetif = AVL_NEXT(&ips->ips_avl_by_index, ipnetif);
                ipnetif_remove(ipnetif, ips);
        }
        avl_destroy(&ips->ips_avl_by_shared);
        avl_destroy(&ips->ips_avl_by_index);
        avl_destroy(&ips->ips_avl_by_name);
        mutex_destroy(&ips->ips_avl_lock);
        mutex_destroy(&ips->ips_walkers_lock);
        cv_destroy(&ips->ips_walkers_cv);
        list_destroy(&ips->ips_str_list);
        kmem_free(ips, sizeof (*ips));
}

/* Do any of the addresses in addrlist belong the supplied zoneid? */
static boolean_t
ipnet_addrs_in_zone(list_t *addrlist, zoneid_t zoneid)
{
        ipnetif_addr_t  *ifa;

        for (ifa = list_head(addrlist); ifa != NULL;
            ifa = list_next(addrlist, ifa)) {
                if (ifa->ifa_zone == zoneid)
                        return (B_TRUE);
        }
        return (B_FALSE);
}

/* Should the supplied ipnetif be visible from the supplied zoneid? */
static boolean_t
ipnetif_in_zone(ipnetif_t *ipnetif, zoneid_t zoneid, ipnet_stack_t *ips)
{
        int     ret;

        /*
         * The global zone has visibility into all interfaces in the global
         * stack, and exclusive stack zones have visibility into all
         * interfaces in their stack.
         */
        if (zoneid == GLOBAL_ZONEID ||
            ips->ips_netstack->netstack_stackid != GLOBAL_NETSTACKID)
                return (B_TRUE);

        /*
         * Shared-stack zones only have visibility for interfaces that have
         * addresses in their zone.
         */
        mutex_enter(&ipnetif->if_addr_lock);
        ret = ipnet_addrs_in_zone(&ipnetif->if_ip4addr_list, zoneid) ||
            ipnet_addrs_in_zone(&ipnetif->if_ip6addr_list, zoneid);
        mutex_exit(&ipnetif->if_addr_lock);
        return (ret);
}

/*
 * Verify that any ipnet_t that has a reference to the supplied ipnetif should
 * still be allowed to have it open.  A given ipnet_t may no longer be allowed
 * to have an ipnetif open if there are no longer any addresses that belong to
 * the ipnetif in the ipnet_t's non-global shared-stack zoneid.  If that's the
 * case, send the ipnet_t an M_HANGUP.
 */
static void
ipnetif_zonecheck(ipnetif_t *ipnetif, ipnet_stack_t *ips)
{
        list_t  *strlist = &ips->ips_str_list;
        ipnet_t *ipnet;

        ipnet_walkers_inc(ips);
        for (ipnet = list_head(strlist); ipnet != NULL;
            ipnet = list_next(strlist, ipnet)) {
                if (ipnet->ipnet_if != ipnetif)
                        continue;
                if (!ipnetif_in_zone(ipnetif, ipnet->ipnet_zoneid, ips))
                        (void) putnextctl(ipnet->ipnet_rq, M_HANGUP);
        }
        ipnet_walkers_dec(ips);
}

void
ipnet_walk_if(ipnet_walkfunc_t *cb, void *arg, zoneid_t zoneid)
{
        ipnetif_t               *ipnetif;
        list_t                  cbdata;
        ipnetif_cbdata_t        *cbnode;
        netstack_t              *ns;
        ipnet_stack_t           *ips;

        /*
         * On labeled systems, non-global zones shouldn't see anything
         * in /dev/ipnet.
         */
        if (is_system_labeled() && zoneid != GLOBAL_ZONEID)
                return;

        if ((ns = netstack_find_by_zoneid(zoneid)) == NULL)
                return;

        ips = ns->netstack_ipnet;
        list_create(&cbdata, sizeof (ipnetif_cbdata_t),
            offsetof(ipnetif_cbdata_t, ic_next));

        mutex_enter(&ips->ips_avl_lock);
        for (ipnetif = avl_first(&ips->ips_avl_by_index); ipnetif != NULL;
            ipnetif = avl_walk(&ips->ips_avl_by_index, ipnetif, AVL_AFTER)) {
                if (!ipnetif_in_zone(ipnetif, zoneid, ips))
                        continue;
                cbnode = kmem_zalloc(sizeof (ipnetif_cbdata_t), KM_SLEEP);
                (void) strlcpy(cbnode->ic_ifname, ipnetif->if_name, LIFNAMSIZ);
                cbnode->ic_dev = ipnetif->if_dev;
                list_insert_head(&cbdata, cbnode);
        }
        mutex_exit(&ips->ips_avl_lock);

        while ((cbnode = list_head(&cbdata)) != NULL) {
                cb(cbnode->ic_ifname, arg, cbnode->ic_dev);
                list_remove(&cbdata, cbnode);
                kmem_free(cbnode, sizeof (ipnetif_cbdata_t));
        }
        list_destroy(&cbdata);
        netstack_rele(ns);
}

static int
ipnetif_compare_index(const void *index_ptr, const void *ipnetifp)
{
        int64_t index1 = *((int64_t *)index_ptr);
        int64_t index2 = (int64_t)((ipnetif_t *)ipnetifp)->if_index;

        return (SIGNOF(index2 - index1));
}

static int
ipnetif_compare_name(const void *name_ptr, const void *ipnetifp)
{
        int     res;

        res = strcmp(((ipnetif_t *)ipnetifp)->if_name, name_ptr);
        return (SIGNOF(res));
}

static int
ipnetif_compare_name_zone(const void *key_ptr, const void *ipnetifp)
{
        const uintptr_t *ptr = key_ptr;
        const ipnetif_t *ifp;
        int             res;

        ifp = ipnetifp;
        res = ifp->if_zoneid - ptr[0];
        if (res != 0)
                return (SIGNOF(res));
        res = strcmp(ifp->if_name, (char *)ptr[1]);
        return (SIGNOF(res));
}

static void
ipnetif_refhold(ipnetif_t *ipnetif)
{
        mutex_enter(&ipnetif->if_reflock);
        ipnetif->if_refcnt++;
        mutex_exit(&ipnetif->if_reflock);
}

static void
ipnetif_refrele(ipnetif_t *ipnetif)
{
        mutex_enter(&ipnetif->if_reflock);
        ASSERT(ipnetif->if_refcnt > 0);
        if (--ipnetif->if_refcnt == 0)
                ipnetif_free(ipnetif);
        else
                mutex_exit(&ipnetif->if_reflock);
}

static void
ipnet_walkers_inc(ipnet_stack_t *ips)
{
        mutex_enter(&ips->ips_walkers_lock);
        ips->ips_walkers_cnt++;
        mutex_exit(&ips->ips_walkers_lock);
}

static void
ipnet_walkers_dec(ipnet_stack_t *ips)
{
        mutex_enter(&ips->ips_walkers_lock);
        ASSERT(ips->ips_walkers_cnt != 0);
        if (--ips->ips_walkers_cnt == 0)
                cv_broadcast(&ips->ips_walkers_cv);
        mutex_exit(&ips->ips_walkers_lock);
}

/*ARGSUSED*/
static int
ipobs_bounce_func(hook_event_token_t token, hook_data_t info, void *arg)
{
        hook_pkt_observe_t      *hdr;
        pfv_t                   func = (pfv_t)arg;
        mblk_t                  *mp;

        hdr = (hook_pkt_observe_t *)info;
        /*
         * Code in ip_input() expects that it is the only one accessing the
         * packet.
         */
        mp = copymsg(hdr->hpo_pkt);
        if (mp == NULL)  {
                netstack_t *ns = hdr->hpo_ctx;
                ipnet_stack_t *ips = ns->netstack_ipnet;

                IPSK_BUMP(ips, ik_dispatchDupDrop);
                return (0);
        }

        hdr = (hook_pkt_observe_t *)mp->b_rptr;
        hdr->hpo_pkt = mp;

        func(mp);

        return (0);
}

hook_t *
ipobs_register_hook(netstack_t *ns, pfv_t func)
{
        ip_stack_t      *ipst = ns->netstack_ip;
        char            name[32];
        hook_t          *hook;

        HOOK_INIT(hook, ipobs_bounce_func, "", (void *)func);
        VERIFY(hook != NULL);

        /*
         * To register multiple hooks with the same callback function,
         * a unique name is needed.
         */
        (void) snprintf(name, sizeof (name), "ipobserve_%p", (void *)hook);
        hook->h_name = strdup(name);

        (void) net_hook_register(ipst->ips_ip4_observe_pr, NH_OBSERVE, hook);
        (void) net_hook_register(ipst->ips_ip6_observe_pr, NH_OBSERVE, hook);

        return (hook);
}

void
ipobs_unregister_hook(netstack_t *ns, hook_t *hook)
{
        ip_stack_t      *ipst = ns->netstack_ip;

        (void) net_hook_unregister(ipst->ips_ip4_observe_pr, NH_OBSERVE, hook);

        (void) net_hook_unregister(ipst->ips_ip6_observe_pr, NH_OBSERVE, hook);

        strfree(hook->h_name);

        hook_free(hook);
}

/* ******************************************************************** */
/* BPF Functions below                                                  */
/* ******************************************************************** */

/*
 * Convenience function to make mapping a zoneid to an ipnet_stack_t easy.
 */
ipnet_stack_t *
ipnet_find_by_zoneid(zoneid_t zoneid)
{
        netstack_t      *ns;

        VERIFY((ns = netstack_find_by_zoneid(zoneid)) != NULL);
        return (ns->netstack_ipnet);
}

/*
 * Functions, such as the above ipnet_find_by_zoneid(), will return a
 * pointer to ipnet_stack_t by calling a netstack lookup function.
 * The netstack_find_*() functions return a pointer after doing a "hold"
 * on the data structure and thereby require a "release" when the caller
 * is finished with it. We need to mirror that API here and thus a caller
 * of ipnet_find_by_zoneid() is required to call ipnet_rele().
 */
void
ipnet_rele(ipnet_stack_t *ips)
{
        netstack_rele(ips->ips_netstack);
}

/*
 */
void
ipnet_set_itap(bpf_itap_fn_t tapfunc)
{
        ipnet_itap = tapfunc;
}

/*
 * The list of interfaces available via ipnet is private for each zone,
 * so the AVL tree of each zone must be searched for a given name, even
 * if all names are unique.
 */
int
ipnet_open_byname(const char *name, ipnetif_t **ptr, zoneid_t zoneid)
{
        ipnet_stack_t   *ips;
        ipnetif_t       *ipnetif;

        ASSERT(ptr != NULL);
        VERIFY((ips = ipnet_find_by_zoneid(zoneid)) != NULL);

        mutex_enter(&ips->ips_avl_lock);

        /*
         * Shared instance zone?
         */
        if (netstackid_to_zoneid(zoneid_to_netstackid(zoneid)) != zoneid) {
                uintptr_t key[2] = { zoneid, (uintptr_t)name };

                ipnetif = avl_find(&ips->ips_avl_by_shared, (void *)key, NULL);
        } else {
                ipnetif = avl_find(&ips->ips_avl_by_name, (void *)name, NULL);
        }
        if (ipnetif != NULL)
                ipnetif_refhold(ipnetif);
        mutex_exit(&ips->ips_avl_lock);

        *ptr = ipnetif;
        ipnet_rele(ips);

        if (ipnetif == NULL)
                return (ESRCH);
        return (0);
}

void
ipnet_close_byhandle(ipnetif_t *ifp)
{
        ASSERT(ifp != NULL);
        ipnetif_refrele(ifp);
}

const char *
ipnet_name(ipnetif_t *ifp)
{
        ASSERT(ifp != NULL);
        return (ifp->if_name);
}

/*
 * To find the linkid for a given name, it is necessary to know which zone
 * the interface name belongs to and to search the avl tree for that zone
 * as there is no master list of all interfaces and which zone they belong
 * to. It is assumed that the caller of this function is somehow already
 * working with the ipnet interfaces and hence the ips_event_lock is held.
 * When BPF calls into this function, it is doing so because of an event
 * in ipnet, and thus ipnet holds the ips_event_lock. Thus the datalink id
 * value returned has meaning without the need for grabbing a hold on the
 * owning structure.
 */
int
ipnet_get_linkid_byname(const char *name, uint_t *idp, zoneid_t zoneid)
{
        ipnet_stack_t   *ips;
        ipnetif_t       *ifp;

        VERIFY((ips = ipnet_find_by_zoneid(zoneid)) != NULL);
        ASSERT(mutex_owned(&ips->ips_event_lock));

        mutex_enter(&ips->ips_avl_lock);
        ifp = avl_find(&ips->ips_avl_by_name, (void *)name, NULL);
        if (ifp != NULL)
                *idp = (uint_t)ifp->if_index;

        /*
         * Shared instance zone?
         */
        if (netstackid_to_zoneid(zoneid_to_netstackid(zoneid)) != zoneid) {
                uintptr_t key[2] = { zoneid, (uintptr_t)name };

                ifp = avl_find(&ips->ips_avl_by_shared, (void *)key, NULL);
                if (ifp != NULL)
                        *idp = (uint_t)ifp->if_index;
        }

        mutex_exit(&ips->ips_avl_lock);
        ipnet_rele(ips);

        if (ifp == NULL)
                return (ESRCH);
        return (0);
}

/*
 * Strictly speaking, there is no such thing as a "client" in ipnet, like
 * there is in mac. BPF only needs to have this because it is required as
 * part of interfacing correctly with mac. The reuse of the original
 * ipnetif_t as a client poses no danger, so long as it is done with its
 * own ref-count'd hold that is given up on close.
 */
int
ipnet_client_open(ipnetif_t *ptr, ipnetif_t **result)
{
        ASSERT(ptr != NULL);
        ASSERT(result != NULL);
        ipnetif_refhold(ptr);
        *result = ptr;

        return (0);
}

void
ipnet_client_close(ipnetif_t *ptr)
{
        ASSERT(ptr != NULL);
        ipnetif_refrele(ptr);
}

/*
 * This is called from BPF when it needs to start receiving packets
 * from ipnet.
 *
 * The use of the ipnet_t structure here is somewhat lightweight when
 * compared to how it is used elsewhere but it already has all of the
 * right fields in it, so reuse here doesn't seem out of order. Its
 * primary purpose here is to provide the means to store pointers for
 * use when ipnet_promisc_remove() needs to be called.
 *
 * This should never be called for the IPNET_MINOR_LO device as it is
 * never created via ipnetif_create.
 */
/*ARGSUSED*/
int
ipnet_promisc_add(void *handle, uint_t how, void *data, uintptr_t *mhandle,
    int flags)
{
        ip_stack_t      *ipst;
        netstack_t      *ns;
        ipnetif_t       *ifp;
        ipnet_t         *ipnet;
        char            name[32];
        int             error;

        ifp = (ipnetif_t *)handle;

        if (how != DL_PROMISC_PHYS && how != DL_PROMISC_MULTI)
                return (EINVAL);

        ns = netstack_find_by_zoneid(ifp->if_zoneid);

        if ((error = ipnet_join_allmulti(ifp, ns->netstack_ipnet)) != 0) {
                netstack_rele(ns);
                return (error);
        }

        ipnet = kmem_zalloc(sizeof (*ipnet), KM_SLEEP);
        ipnet->ipnet_if = ifp;
        ipnet->ipnet_ns = ns;
        ipnet->ipnet_flags = flags;

        if ((ifp->if_flags & IPNETIF_LOOPBACK) != 0) {
                ipnet->ipnet_acceptfn = ipnet_loaccept;
        } else {
                ipnet->ipnet_acceptfn = ipnet_accept;
        }

        /*
         * To register multiple hooks with the same callback function,
         * a unique name is needed.
         */
        HOOK_INIT(ipnet->ipnet_hook, ipnet_bpf_bounce, "", ipnet);
        (void) snprintf(name, sizeof (name), "ipnet_promisc_%p",
            (void *)ipnet->ipnet_hook);
        ipnet->ipnet_hook->h_name = strdup(name);
        ipnet->ipnet_data = data;
        ipnet->ipnet_zoneid = ifp->if_zoneid;

        ipst = ns->netstack_ip;

        error = net_hook_register(ipst->ips_ip4_observe_pr, NH_OBSERVE,
            ipnet->ipnet_hook);
        if (error != 0)
                goto regfail;

        error = net_hook_register(ipst->ips_ip6_observe_pr, NH_OBSERVE,
            ipnet->ipnet_hook);
        if (error != 0) {
                (void) net_hook_unregister(ipst->ips_ip4_observe_pr,
                    NH_OBSERVE, ipnet->ipnet_hook);
                goto regfail;
        }

        *mhandle = (uintptr_t)ipnet;
        netstack_rele(ns);

        return (0);

regfail:
        cmn_err(CE_WARN, "net_hook_register failed: %d", error);
        strfree(ipnet->ipnet_hook->h_name);
        hook_free(ipnet->ipnet_hook);
        netstack_rele(ns);
        return (error);
}

void
ipnet_promisc_remove(void *data)
{
        ip_stack_t      *ipst;
        ipnet_t         *ipnet;
        hook_t          *hook;

        ipnet = data;
        ipst = ipnet->ipnet_ns->netstack_ip;
        hook = ipnet->ipnet_hook;

        VERIFY(net_hook_unregister(ipst->ips_ip4_observe_pr, NH_OBSERVE,
            hook) == 0);

        VERIFY(net_hook_unregister(ipst->ips_ip6_observe_pr, NH_OBSERVE,
            hook) == 0);

        strfree(hook->h_name);

        hook_free(hook);

        kmem_free(ipnet, sizeof (*ipnet));
}

/*
 * arg here comes from the ipnet_t allocated in ipnet_promisc_add.
 * An important field from that structure is "ipnet_data" that
 * contains the "data" pointer passed into ipnet_promisc_add: it needs
 * to be passed back to bpf when we call into ipnet_itap.
 *
 * ipnet_itap is set by ipnet_set_bpfattach, which in turn is called
 * from BPF.
 */
/*ARGSUSED*/
static int
ipnet_bpf_bounce(hook_event_token_t token, hook_data_t info, void *arg)
{
        hook_pkt_observe_t      *hdr;
        ipnet_addrp_t           src;
        ipnet_addrp_t           dst;
        ipnet_stack_t           *ips;
        ipnet_t                 *ipnet;
        mblk_t                  *netmp;
        mblk_t                  *mp;

        hdr = (hook_pkt_observe_t *)info;
        mp = hdr->hpo_pkt;
        ipnet = (ipnet_t *)arg;
        ips = ((netstack_t *)hdr->hpo_ctx)->netstack_ipnet;

        netmp = hdr->hpo_pkt->b_cont;
        src.iap_family = hdr->hpo_family;
        dst.iap_family = hdr->hpo_family;

        if (hdr->hpo_family == AF_INET) {
                src.iap_addr4 = &((ipha_t *)(netmp->b_rptr))->ipha_src;
                dst.iap_addr4 = &((ipha_t *)(netmp->b_rptr))->ipha_dst;
        } else {
                src.iap_addr6 = &((ip6_t *)(netmp->b_rptr))->ip6_src;
                dst.iap_addr6 = &((ip6_t *)(netmp->b_rptr))->ip6_dst;
        }

        if (!(*ipnet->ipnet_acceptfn)(ipnet, hdr, &src, &dst)) {
                IPSK_BUMP(ips, ik_acceptFail);
                return (0);
        }
        IPSK_BUMP(ips, ik_acceptOk);

        ipnet_itap(ipnet->ipnet_data, mp,
            hdr->hpo_htype == htons(IPOBS_HOOK_OUTBOUND),
            ntohl(hdr->hpo_pktlen) + MBLKL(mp));

        return (0);
}

/*
 * clone'd ipnetif_t's are created when a shared IP instance zone comes
 * to life and configures an IP address. The model that BPF uses is that
 * each interface must have a unique pointer and each interface must be
 * representative of what it can capture. They are limited to one DLT
 * per interface and one zone per interface. Thus every interface that
 * can be seen in a zone must be announced via an attach to bpf. For
 * shared instance zones, this means the ipnet driver needs to detect
 * when an address is added to an interface in a zone for the first
 * time (and also when the last address is removed.)
 */
static ipnetif_t *
ipnetif_clone_create(ipnetif_t *ifp, zoneid_t zoneid)
{
        uintptr_t       key[2] = { zoneid, (uintptr_t)ifp->if_name };
        ipnet_stack_t   *ips = ifp->if_stackp;
        avl_index_t     where = 0;
        ipnetif_t       *newif;

        mutex_enter(&ips->ips_avl_lock);
        newif = avl_find(&ips->ips_avl_by_shared, (void *)key, &where);
        if (newif != NULL) {
                ipnetif_refhold(newif);
                newif->if_sharecnt++;
                mutex_exit(&ips->ips_avl_lock);
                return (newif);
        }

        newif = ipnet_alloc_if(ips);
        if (newif == NULL) {
                mutex_exit(&ips->ips_avl_lock);
                return (NULL);
        }

        newif->if_refcnt = 1;
        newif->if_sharecnt = 1;
        newif->if_zoneid = zoneid;
        (void) strlcpy(newif->if_name, ifp->if_name, LIFNAMSIZ);
        newif->if_flags = ifp->if_flags & IPNETIF_LOOPBACK;
        newif->if_index = ifp->if_index;

        avl_insert(&ips->ips_avl_by_shared, newif, where);
        mutex_exit(&ips->ips_avl_lock);

        return (newif);
}

static void
ipnetif_clone_release(ipnetif_t *ipnetif)
{
        boolean_t       dofree = B_FALSE;
        boolean_t       doremove = B_FALSE;
        ipnet_stack_t   *ips = ipnetif->if_stackp;

        mutex_enter(&ipnetif->if_reflock);
        ASSERT(ipnetif->if_refcnt > 0);
        if (--ipnetif->if_refcnt == 0)
                dofree = B_TRUE;
        ASSERT(ipnetif->if_sharecnt > 0);
        if (--ipnetif->if_sharecnt == 0)
                doremove = B_TRUE;
        mutex_exit(&ipnetif->if_reflock);
        if (doremove) {
                mutex_enter(&ips->ips_avl_lock);
                avl_remove(&ips->ips_avl_by_shared, ipnetif);
                mutex_exit(&ips->ips_avl_lock);
        }
        if (dofree) {
                ASSERT(ipnetif->if_sharecnt == 0);
                ipnetif_free(ipnetif);
        }
}