Improve the customizeiso step to allow restarts

[dragonfly.git] / sys / net / if.c

/*
 * Copyright (c) 1980, 1986, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)if.c        8.3 (Berkeley) 1/4/94
 * $FreeBSD: src/sys/net/if.c,v 1.185 2004/03/13 02:35:03 brooks Exp $
 * $DragonFly: src/sys/net/if.c,v 1.84 2008/11/15 11:58:16 sephe Exp $
 */

#include "opt_compat.h"
#include "opt_inet6.h"
#include "opt_inet.h"
#include "opt_polling.h"

#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/priv.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/socketops.h>
#include <sys/protosw.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/sockio.h>
#include <sys/syslog.h>
#include <sys/sysctl.h>
#include <sys/domain.h>
#include <sys/thread.h>
#include <sys/thread2.h>
#include <sys/serialize.h>
#include <sys/msgport2.h>
#include <sys/bus.h>

#include <net/if.h>
#include <net/if_arp.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/if_var.h>
#include <net/ifq_var.h>
#include <net/radix.h>
#include <net/route.h>
#include <net/if_clone.h>
#include <net/netisr.h>
#include <net/netmsg2.h>

#include <machine/atomic.h>
#include <machine/stdarg.h>
#include <machine/smp.h>

#if defined(INET) || defined(INET6)
/*XXX*/
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/if_ether.h>
#ifdef INET6
#include <netinet6/in6_var.h>
#include <netinet6/in6_ifattach.h>
#endif
#endif

#if defined(COMPAT_43)
#include <emulation/43bsd/43bsd_socket.h>
#endif /* COMPAT_43 */

struct netmsg_ifaddr {
        struct netmsg   netmsg;
        struct ifaddr   *ifa;
        struct ifnet    *ifp;
        int             tail;
};

/*
 * System initialization
 */
static void     if_attachdomain(void *);
static void     if_attachdomain1(struct ifnet *);
static int      ifconf(u_long, caddr_t, struct ucred *);
static void     ifinit(void *);
static void     ifnetinit(void *);
static void     if_slowtimo(void *);
static void     link_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
static int      if_rtdel(struct radix_node *, void *);

#ifdef INET6
/*
 * XXX: declare here to avoid to include many inet6 related files..
 * should be more generalized?
 */
extern void     nd6_setmtu(struct ifnet *);
#endif

SYSCTL_NODE(_net, PF_LINK, link, CTLFLAG_RW, 0, "Link layers");
SYSCTL_NODE(_net_link, 0, generic, CTLFLAG_RW, 0, "Generic link-management");

SYSINIT(interfaces, SI_SUB_PROTO_IF, SI_ORDER_FIRST, ifinit, NULL)
/* Must be after netisr_init */
SYSINIT(ifnet, SI_SUB_PRE_DRIVERS, SI_ORDER_SECOND, ifnetinit, NULL)

MALLOC_DEFINE(M_IFADDR, "ifaddr", "interface address");
MALLOC_DEFINE(M_IFMADDR, "ether_multi", "link-level multicast address");

int                     ifqmaxlen = IFQ_MAXLEN;
struct ifnethead        ifnet = TAILQ_HEAD_INITIALIZER(ifnet);

/* In ifq_dispatch(), try to do direct ifnet.if_start first */
static int              ifq_dispatch_schedonly = 0;
SYSCTL_INT(_net_link_generic, OID_AUTO, ifq_dispatch_schedonly, CTLFLAG_RW,
           &ifq_dispatch_schedonly, 0, "");

/* In ifq_dispatch(), schedule ifnet.if_start without checking ifnet.if_snd */
static int              ifq_dispatch_schednochk = 0;
SYSCTL_INT(_net_link_generic, OID_AUTO, ifq_dispatch_schednochk, CTLFLAG_RW,
           &ifq_dispatch_schednochk, 0, "");

/* In if_devstart(), try to do direct ifnet.if_start first */
static int              if_devstart_schedonly = 0;
SYSCTL_INT(_net_link_generic, OID_AUTO, if_devstart_schedonly, CTLFLAG_RW,
           &if_devstart_schedonly, 0, "");

/* In if_devstart(), schedule ifnet.if_start without checking ifnet.if_snd */
static int              if_devstart_schednochk = 0;
SYSCTL_INT(_net_link_generic, OID_AUTO, if_devstart_schednochk, CTLFLAG_RW,
           &if_devstart_schednochk, 0, "");

#ifdef SMP
/* Schedule ifnet.if_start on the current CPU */
static int              if_start_oncpu_sched = 0;
SYSCTL_INT(_net_link_generic, OID_AUTO, if_start_oncpu_sched, CTLFLAG_RW,
           &if_start_oncpu_sched, 0, "");
#endif

struct callout          if_slowtimo_timer;

int                     if_index = 0;
struct ifnet            **ifindex2ifnet = NULL;
static struct thread    ifnet_threads[MAXCPU];
static int              ifnet_mpsafe_thread = NETMSG_SERVICE_MPSAFE;

#define IFQ_KTR_STRING          "ifq=%p"
#define IFQ_KTR_ARG_SIZE        (sizeof(void *))
#ifndef KTR_IFQ
#define KTR_IFQ                 KTR_ALL
#endif
KTR_INFO_MASTER(ifq);
KTR_INFO(KTR_IFQ, ifq, enqueue, 0, IFQ_KTR_STRING, IFQ_KTR_ARG_SIZE);
KTR_INFO(KTR_IFQ, ifq, dequeue, 1, IFQ_KTR_STRING, IFQ_KTR_ARG_SIZE);
#define logifq(name, arg)       KTR_LOG(ifq_ ## name, arg)

#define IF_START_KTR_STRING     "ifp=%p"
#define IF_START_KTR_ARG_SIZE   (sizeof(void *))
#ifndef KTR_IF_START
#define KTR_IF_START            KTR_ALL
#endif
KTR_INFO_MASTER(if_start);
KTR_INFO(KTR_IF_START, if_start, run, 0,
         IF_START_KTR_STRING, IF_START_KTR_ARG_SIZE);
KTR_INFO(KTR_IF_START, if_start, sched, 1,
         IF_START_KTR_STRING, IF_START_KTR_ARG_SIZE);
KTR_INFO(KTR_IF_START, if_start, avoid, 2,
         IF_START_KTR_STRING, IF_START_KTR_ARG_SIZE);
KTR_INFO(KTR_IF_START, if_start, contend_sched, 3,
         IF_START_KTR_STRING, IF_START_KTR_ARG_SIZE);
KTR_INFO(KTR_IF_START, if_start, chase_sched, 4,
         IF_START_KTR_STRING, IF_START_KTR_ARG_SIZE);
#define logifstart(name, arg)   KTR_LOG(if_start_ ## name, arg)

/*
 * Network interface utility routines.
 *
 * Routines with ifa_ifwith* names take sockaddr *'s as
 * parameters.
 */
/* ARGSUSED*/
void
ifinit(void *dummy)
{
        struct ifnet *ifp;

        callout_init(&if_slowtimo_timer);

        crit_enter();
        TAILQ_FOREACH(ifp, &ifnet, if_link) {
                if (ifp->if_snd.ifq_maxlen == 0) {
                        if_printf(ifp, "XXX: driver didn't set ifq_maxlen\n");
                        ifp->if_snd.ifq_maxlen = ifqmaxlen;
                }
        }
        crit_exit();

        if_slowtimo(0);
}

static int
if_start_cpuid(struct ifnet *ifp)
{
        return ifp->if_cpuid;
}

#ifdef DEVICE_POLLING
static int
if_start_cpuid_poll(struct ifnet *ifp)
{
        int poll_cpuid = ifp->if_poll_cpuid;

        if (poll_cpuid >= 0)
                return poll_cpuid;
        else
                return ifp->if_cpuid;
}
#endif

static void
if_start_ipifunc(void *arg)
{
        struct ifnet *ifp = arg;
        struct lwkt_msg *lmsg = &ifp->if_start_nmsg[mycpuid].nm_lmsg;

        crit_enter();
        if (lmsg->ms_flags & MSGF_DONE)
                lwkt_sendmsg(ifnet_portfn(mycpuid), lmsg);
        crit_exit();
}

/*
 * Schedule ifnet.if_start on ifnet's CPU
 */
static void
if_start_schedule(struct ifnet *ifp)
{
#ifdef SMP
        int cpu;

        if (if_start_oncpu_sched)
                cpu = mycpuid;
        else
                cpu = ifp->if_start_cpuid(ifp);

        if (cpu != mycpuid)
                lwkt_send_ipiq(globaldata_find(cpu), if_start_ipifunc, ifp);
        else
#endif
        if_start_ipifunc(ifp);
}

/*
 * NOTE:
 * This function will release ifnet.if_start interlock,
 * if ifnet.if_start does not need to be scheduled
 */
static __inline int
if_start_need_schedule(struct ifaltq *ifq, int running)
{
        if (!running || ifq_is_empty(ifq)
#ifdef ALTQ
            || ifq->altq_tbr != NULL
#endif
        ) {
                ALTQ_LOCK(ifq);
                /*
                 * ifnet.if_start interlock is released, if:
                 * 1) Hardware can not take any packets, due to
                 *    o  interface is marked down
                 *    o  hardware queue is full (IFF_OACTIVE)
                 *    Under the second situation, hardware interrupt
                 *    or polling(4) will call/schedule ifnet.if_start
                 *    when hardware queue is ready
                 * 2) There is not packet in the ifnet.if_snd.
                 *    Further ifq_dispatch or ifq_handoff will call/
                 *    schedule ifnet.if_start
                 * 3) TBR is used and it does not allow further
                 *    dequeueing.
                 *    TBR callout will call ifnet.if_start
                 */
                if (!running || !ifq_data_ready(ifq)) {
                        ifq->altq_started = 0;
                        ALTQ_UNLOCK(ifq);
                        return 0;
                }
                ALTQ_UNLOCK(ifq);
        }
        return 1;
}

static void
if_start_dispatch(struct netmsg *nmsg)
{
        struct lwkt_msg *lmsg = &nmsg->nm_lmsg;
        struct ifnet *ifp = lmsg->u.ms_resultp;
        struct ifaltq *ifq = &ifp->if_snd;
        int running = 0;

        crit_enter();
        lwkt_replymsg(lmsg, 0); /* reply ASAP */
        crit_exit();

#ifdef SMP
        if (!if_start_oncpu_sched && mycpuid != ifp->if_start_cpuid(ifp)) {
                /*
                 * If the ifnet is still up, we need to
                 * chase its CPU change.
                 */
                if (ifp->if_flags & IFF_UP) {
                        logifstart(chase_sched, ifp);
                        if_start_schedule(ifp);
                        return;
                } else {
                        goto check;
                }
        }
#endif

        if (ifp->if_flags & IFF_UP) {
                lwkt_serialize_enter(ifp->if_serializer); /* XXX try? */
                if ((ifp->if_flags & IFF_OACTIVE) == 0) {
                        logifstart(run, ifp);
                        ifp->if_start(ifp);
                        if ((ifp->if_flags &
                        (IFF_OACTIVE | IFF_RUNNING)) == IFF_RUNNING)
                                running = 1;
                }
                lwkt_serialize_exit(ifp->if_serializer);
        }
#ifdef SMP
check:
#endif
        if (if_start_need_schedule(ifq, running)) {
                crit_enter();
                if (lmsg->ms_flags & MSGF_DONE) { /* XXX necessary? */
                        logifstart(sched, ifp);
                        lwkt_sendmsg(ifnet_portfn(mycpuid), lmsg);
                }
                crit_exit();
        }
}

/* Device driver ifnet.if_start helper function */
void
if_devstart(struct ifnet *ifp)
{
        struct ifaltq *ifq = &ifp->if_snd;
        int running = 0;

        ASSERT_SERIALIZED(ifp->if_serializer);

        ALTQ_LOCK(ifq);
        if (ifq->altq_started || !ifq_data_ready(ifq)) {
                logifstart(avoid, ifp);
                ALTQ_UNLOCK(ifq);
                return;
        }
        ifq->altq_started = 1;
        ALTQ_UNLOCK(ifq);

        if (if_devstart_schedonly) {
                /*
                 * Always schedule ifnet.if_start on ifnet's CPU,
                 * short circuit the rest of this function.
                 */
                logifstart(sched, ifp);
                if_start_schedule(ifp);
                return;
        }

        logifstart(run, ifp);
        ifp->if_start(ifp);

        if ((ifp->if_flags & (IFF_OACTIVE | IFF_RUNNING)) == IFF_RUNNING)
                running = 1;

        if (if_devstart_schednochk || if_start_need_schedule(ifq, running)) {
                /*
                 * More data need to be transmitted, ifnet.if_start is
                 * scheduled on ifnet's CPU, and we keep going.
                 * NOTE: ifnet.if_start interlock is not released.
                 */
                logifstart(sched, ifp);
                if_start_schedule(ifp);
        }
}

/*
 * Attach an interface to the list of "active" interfaces.
 *
 * The serializer is optional.  If non-NULL access to the interface
 * may be MPSAFE.
 */
void
if_attach(struct ifnet *ifp, lwkt_serialize_t serializer)
{
        unsigned socksize, ifasize;
        int namelen, masklen;
        struct sockaddr_dl *sdl;
        struct ifaddr *ifa;
        struct ifaltq *ifq;
        int i;

        static int if_indexlim = 8;

        /*
         * The serializer can be passed in from the device, allowing the
         * same serializer to be used for both the interrupt interlock and
         * the device queue.  If not specified, the netif structure will
         * use an embedded serializer.
         */
        if (serializer == NULL) {
                serializer = &ifp->if_default_serializer;
                lwkt_serialize_init(serializer);
        }
        ifp->if_serializer = serializer;

        ifp->if_start_cpuid = if_start_cpuid;
        ifp->if_cpuid = 0;

#ifdef DEVICE_POLLING
        /* Device is not in polling mode by default */
        ifp->if_poll_cpuid = -1;
        if (ifp->if_poll != NULL)
                ifp->if_start_cpuid = if_start_cpuid_poll;
#endif

        ifp->if_start_nmsg = kmalloc(ncpus * sizeof(struct netmsg),
                                     M_LWKTMSG, M_WAITOK);
        for (i = 0; i < ncpus; ++i) {
                netmsg_init(&ifp->if_start_nmsg[i], &netisr_adone_rport, 0,
                            if_start_dispatch);
                ifp->if_start_nmsg[i].nm_lmsg.u.ms_resultp = ifp;
        }

        TAILQ_INSERT_TAIL(&ifnet, ifp, if_link);
        ifp->if_index = ++if_index;

        /*
         * XXX -
         * The old code would work if the interface passed a pre-existing
         * chain of ifaddrs to this code.  We don't trust our callers to
         * properly initialize the tailq, however, so we no longer allow
         * this unlikely case.
         */
        ifp->if_addrheads = kmalloc(ncpus * sizeof(struct ifaddrhead),
                                    M_IFADDR, M_WAITOK | M_ZERO);
        for (i = 0; i < ncpus; ++i)
                TAILQ_INIT(&ifp->if_addrheads[i]);

        TAILQ_INIT(&ifp->if_prefixhead);
        LIST_INIT(&ifp->if_multiaddrs);
        getmicrotime(&ifp->if_lastchange);
        if (ifindex2ifnet == NULL || if_index >= if_indexlim) {
                unsigned int n;
                struct ifnet **q;

                if_indexlim <<= 1;

                /* grow ifindex2ifnet */
                n = if_indexlim * sizeof(*q);
                q = kmalloc(n, M_IFADDR, M_WAITOK | M_ZERO);
                if (ifindex2ifnet) {
                        bcopy(ifindex2ifnet, q, n/2);
                        kfree(ifindex2ifnet, M_IFADDR);
                }
                ifindex2ifnet = q;
        }

        ifindex2ifnet[if_index] = ifp;

        /*
         * create a Link Level name for this device
         */
        namelen = strlen(ifp->if_xname);
#define _offsetof(t, m) ((int)((caddr_t)&((t *)0)->m))
        masklen = _offsetof(struct sockaddr_dl, sdl_data[0]) + namelen;
        socksize = masklen + ifp->if_addrlen;
#define ROUNDUP(a) (1 + (((a) - 1) | (sizeof(long) - 1)))
        if (socksize < sizeof(*sdl))
                socksize = sizeof(*sdl);
        socksize = ROUNDUP(socksize);
        ifasize = sizeof(struct ifaddr) + 2 * socksize;
        ifa = ifa_create(ifasize, M_WAITOK);
        sdl = (struct sockaddr_dl *)(ifa + 1);
        sdl->sdl_len = socksize;
        sdl->sdl_family = AF_LINK;
        bcopy(ifp->if_xname, sdl->sdl_data, namelen);
        sdl->sdl_nlen = namelen;
        sdl->sdl_index = ifp->if_index;
        sdl->sdl_type = ifp->if_type;
        ifp->if_lladdr = ifa;
        ifa->ifa_ifp = ifp;
        ifa->ifa_rtrequest = link_rtrequest;
        ifa->ifa_addr = (struct sockaddr *)sdl;
        sdl = (struct sockaddr_dl *)(socksize + (caddr_t)sdl);
        ifa->ifa_netmask = (struct sockaddr *)sdl;
        sdl->sdl_len = masklen;
        while (namelen != 0)
                sdl->sdl_data[--namelen] = 0xff;
        ifa_iflink(ifa, ifp, 0 /* Insert head */);

        EVENTHANDLER_INVOKE(ifnet_attach_event, ifp);
        devctl_notify("IFNET", ifp->if_xname, "ATTACH", NULL);

        ifq = &ifp->if_snd;
        ifq->altq_type = 0;
        ifq->altq_disc = NULL;
        ifq->altq_flags &= ALTQF_CANTCHANGE;
        ifq->altq_tbr = NULL;
        ifq->altq_ifp = ifp;
        ifq->altq_started = 0;
        ifq->altq_prepended = NULL;
        ALTQ_LOCK_INIT(ifq);
        ifq_set_classic(ifq);

        if (!SLIST_EMPTY(&domains))
                if_attachdomain1(ifp);

        /* Announce the interface. */
        rt_ifannouncemsg(ifp, IFAN_ARRIVAL);
}

static void
if_attachdomain(void *dummy)
{
        struct ifnet *ifp;

        crit_enter();
        TAILQ_FOREACH(ifp, &ifnet, if_list)
                if_attachdomain1(ifp);
        crit_exit();
}
SYSINIT(domainifattach, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_FIRST,
        if_attachdomain, NULL);

static void
if_attachdomain1(struct ifnet *ifp)
{
        struct domain *dp;

        crit_enter();

        /* address family dependent data region */
        bzero(ifp->if_afdata, sizeof(ifp->if_afdata));
        SLIST_FOREACH(dp, &domains, dom_next)
                if (dp->dom_ifattach)
                        ifp->if_afdata[dp->dom_family] =
                                (*dp->dom_ifattach)(ifp);
        crit_exit();
}

/*
 * Purge all addresses whose type is _not_ AF_LINK
 */
void
if_purgeaddrs_nolink(struct ifnet *ifp)
{
        struct ifaddr_container *ifac, *next;

        TAILQ_FOREACH_MUTABLE(ifac, &ifp->if_addrheads[mycpuid],
                              ifa_link, next) {
                struct ifaddr *ifa = ifac->ifa;

                /* Leave link ifaddr as it is */
                if (ifa->ifa_addr->sa_family == AF_LINK)
                        continue;
#ifdef INET
                /* XXX: Ugly!! ad hoc just for INET */
                if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) {
                        struct ifaliasreq ifr;
#ifdef IFADDR_DEBUG_VERBOSE
                        int i;

                        kprintf("purge in4 addr %p: ", ifa);
                        for (i = 0; i < ncpus; ++i)
                                kprintf("%d ", ifa->ifa_containers[i].ifa_refcnt);
                        kprintf("\n");
#endif

                        bzero(&ifr, sizeof ifr);
                        ifr.ifra_addr = *ifa->ifa_addr;
                        if (ifa->ifa_dstaddr)
                                ifr.ifra_broadaddr = *ifa->ifa_dstaddr;
                        if (in_control(NULL, SIOCDIFADDR, (caddr_t)&ifr, ifp,
                                       NULL) == 0)
                                continue;
                }
#endif /* INET */
#ifdef INET6
                if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET6) {
#ifdef IFADDR_DEBUG_VERBOSE
                        int i;

                        kprintf("purge in6 addr %p: ", ifa);
                        for (i = 0; i < ncpus; ++i)
                                kprintf("%d ", ifa->ifa_containers[i].ifa_refcnt);
                        kprintf("\n");
#endif

                        in6_purgeaddr(ifa);
                        /* ifp_addrhead is already updated */
                        continue;
                }
#endif /* INET6 */
                ifa_ifunlink(ifa, ifp);
                ifa_destroy(ifa);
        }
}

/*
 * Detach an interface, removing it from the
 * list of "active" interfaces.
 */
void
if_detach(struct ifnet *ifp)
{
        struct radix_node_head  *rnh;
        int i;
        int cpu, origcpu;
        struct domain *dp;

        EVENTHANDLER_INVOKE(ifnet_detach_event, ifp);

        /*
         * Remove routes and flush queues.
         */
        crit_enter();
#ifdef DEVICE_POLLING
        if (ifp->if_flags & IFF_POLLING)
                ether_poll_deregister(ifp);
#endif
        if_down(ifp);

        if (ifq_is_enabled(&ifp->if_snd))
                altq_disable(&ifp->if_snd);
        if (ifq_is_attached(&ifp->if_snd))
                altq_detach(&ifp->if_snd);

        /*
         * Clean up all addresses.
         */
        ifp->if_lladdr = NULL;

        if_purgeaddrs_nolink(ifp);
        if (!TAILQ_EMPTY(&ifp->if_addrheads[mycpuid])) {
                struct ifaddr *ifa;

                ifa = TAILQ_FIRST(&ifp->if_addrheads[mycpuid])->ifa;
                KASSERT(ifa->ifa_addr->sa_family == AF_LINK,
                        ("non-link ifaddr is left on if_addrheads"));

                ifa_ifunlink(ifa, ifp);
                ifa_destroy(ifa);
                KASSERT(TAILQ_EMPTY(&ifp->if_addrheads[mycpuid]),
                        ("there are still ifaddrs left on if_addrheads"));
        }

#ifdef INET
        /*
         * Remove all IPv4 kernel structures related to ifp.
         */
        in_ifdetach(ifp);
#endif

#ifdef INET6
        /*
         * Remove all IPv6 kernel structs related to ifp.  This should be done
         * before removing routing entries below, since IPv6 interface direct
         * routes are expected to be removed by the IPv6-specific kernel API.
         * Otherwise, the kernel will detect some inconsistency and bark it.
         */
        in6_ifdetach(ifp);
#endif

        /*
         * Delete all remaining routes using this interface
         * Unfortuneatly the only way to do this is to slog through
         * the entire routing table looking for routes which point
         * to this interface...oh well...
         */
        origcpu = mycpuid;
        for (cpu = 0; cpu < ncpus2; cpu++) {
                lwkt_migratecpu(cpu);
                for (i = 1; i <= AF_MAX; i++) {
                        if ((rnh = rt_tables[cpu][i]) == NULL)
                                continue;
                        rnh->rnh_walktree(rnh, if_rtdel, ifp);
                }
        }
        lwkt_migratecpu(origcpu);

        /* Announce that the interface is gone. */
        rt_ifannouncemsg(ifp, IFAN_DEPARTURE);
        devctl_notify("IFNET", ifp->if_xname, "DETACH", NULL);

        SLIST_FOREACH(dp, &domains, dom_next)
                if (dp->dom_ifdetach && ifp->if_afdata[dp->dom_family])
                        (*dp->dom_ifdetach)(ifp,
                                ifp->if_afdata[dp->dom_family]);

        /*
         * Remove interface from ifindex2ifp[] and maybe decrement if_index.
         */
        ifindex2ifnet[ifp->if_index] = NULL;
        while (if_index > 0 && ifindex2ifnet[if_index] == NULL)
                if_index--;

        TAILQ_REMOVE(&ifnet, ifp, if_link);
        kfree(ifp->if_addrheads, M_IFADDR);
        kfree(ifp->if_start_nmsg, M_LWKTMSG);
        crit_exit();
}

/*
 * Delete Routes for a Network Interface
 *
 * Called for each routing entry via the rnh->rnh_walktree() call above
 * to delete all route entries referencing a detaching network interface.
 *
 * Arguments:
 *      rn      pointer to node in the routing table
 *      arg     argument passed to rnh->rnh_walktree() - detaching interface
 *
 * Returns:
 *      0       successful
 *      errno   failed - reason indicated
 *
 */
static int
if_rtdel(struct radix_node *rn, void *arg)
{
        struct rtentry  *rt = (struct rtentry *)rn;
        struct ifnet    *ifp = arg;
        int             err;

        if (rt->rt_ifp == ifp) {

                /*
                 * Protect (sorta) against walktree recursion problems
                 * with cloned routes
                 */
                if (!(rt->rt_flags & RTF_UP))
                        return (0);

                err = rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway,
                                rt_mask(rt), rt->rt_flags,
                                (struct rtentry **) NULL);
                if (err) {
                        log(LOG_WARNING, "if_rtdel: error %d\n", err);
                }
        }

        return (0);
}

/*
 * Locate an interface based on a complete address.
 */
struct ifaddr *
ifa_ifwithaddr(struct sockaddr *addr)
{
        struct ifnet *ifp;

        TAILQ_FOREACH(ifp, &ifnet, if_link) {
                struct ifaddr_container *ifac;

                TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
                        struct ifaddr *ifa = ifac->ifa;

                        if (ifa->ifa_addr->sa_family != addr->sa_family)
                                continue;
                        if (sa_equal(addr, ifa->ifa_addr))
                                return (ifa);
                        if ((ifp->if_flags & IFF_BROADCAST) &&
                            ifa->ifa_broadaddr &&
                            /* IPv6 doesn't have broadcast */
                            ifa->ifa_broadaddr->sa_len != 0 &&
                            sa_equal(ifa->ifa_broadaddr, addr))
                                return (ifa);
                }
        }
        return (NULL);
}
/*
 * Locate the point to point interface with a given destination address.
 */
struct ifaddr *
ifa_ifwithdstaddr(struct sockaddr *addr)
{
        struct ifnet *ifp;

        TAILQ_FOREACH(ifp, &ifnet, if_link) {
                struct ifaddr_container *ifac;

                if (!(ifp->if_flags & IFF_POINTOPOINT))
                        continue;

                TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
                        struct ifaddr *ifa = ifac->ifa;

                        if (ifa->ifa_addr->sa_family != addr->sa_family)
                                continue;
                        if (ifa->ifa_dstaddr &&
                            sa_equal(addr, ifa->ifa_dstaddr))
                                return (ifa);
                }
        }
        return (NULL);
}

/*
 * Find an interface on a specific network.  If many, choice
 * is most specific found.
 */
struct ifaddr *
ifa_ifwithnet(struct sockaddr *addr)
{
        struct ifnet *ifp;
        struct ifaddr *ifa_maybe = NULL;
        u_int af = addr->sa_family;
        char *addr_data = addr->sa_data, *cplim;

        /*
         * AF_LINK addresses can be looked up directly by their index number,
         * so do that if we can.
         */
        if (af == AF_LINK) {
                struct sockaddr_dl *sdl = (struct sockaddr_dl *)addr;

                if (sdl->sdl_index && sdl->sdl_index <= if_index)
                        return (ifindex2ifnet[sdl->sdl_index]->if_lladdr);
        }

        /*
         * Scan though each interface, looking for ones that have
         * addresses in this address family.
         */
        TAILQ_FOREACH(ifp, &ifnet, if_link) {
                struct ifaddr_container *ifac;

                TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
                        struct ifaddr *ifa = ifac->ifa;
                        char *cp, *cp2, *cp3;

                        if (ifa->ifa_addr->sa_family != af)
next:                           continue;
                        if (af == AF_INET && ifp->if_flags & IFF_POINTOPOINT) {
                                /*
                                 * This is a bit broken as it doesn't
                                 * take into account that the remote end may
                                 * be a single node in the network we are
                                 * looking for.
                                 * The trouble is that we don't know the
                                 * netmask for the remote end.
                                 */
                                if (ifa->ifa_dstaddr != NULL &&
                                    sa_equal(addr, ifa->ifa_dstaddr))
                                        return (ifa);
                        } else {
                                /*
                                 * if we have a special address handler,
                                 * then use it instead of the generic one.
                                 */
                                if (ifa->ifa_claim_addr) {
                                        if ((*ifa->ifa_claim_addr)(ifa, addr)) {
                                                return (ifa);
                                        } else {
                                                continue;
                                        }
                                }

                                /*
                                 * Scan all the bits in the ifa's address.
                                 * If a bit dissagrees with what we are
                                 * looking for, mask it with the netmask
                                 * to see if it really matters.
                                 * (A byte at a time)
                                 */
                                if (ifa->ifa_netmask == 0)
                                        continue;
                                cp = addr_data;
                                cp2 = ifa->ifa_addr->sa_data;
                                cp3 = ifa->ifa_netmask->sa_data;
                                cplim = ifa->ifa_netmask->sa_len +
                                        (char *)ifa->ifa_netmask;
                                while (cp3 < cplim)
                                        if ((*cp++ ^ *cp2++) & *cp3++)
                                                goto next; /* next address! */
                                /*
                                 * If the netmask of what we just found
                                 * is more specific than what we had before
                                 * (if we had one) then remember the new one
                                 * before continuing to search
                                 * for an even better one.
                                 */
                                if (ifa_maybe == 0 ||
                                    rn_refines((char *)ifa->ifa_netmask,
                                               (char *)ifa_maybe->ifa_netmask))
                                        ifa_maybe = ifa;
                        }
                }
        }
        return (ifa_maybe);
}

/*
 * Find an interface address specific to an interface best matching
 * a given address.
 */
struct ifaddr *
ifaof_ifpforaddr(struct sockaddr *addr, struct ifnet *ifp)
{
        struct ifaddr_container *ifac;
        char *cp, *cp2, *cp3;
        char *cplim;
        struct ifaddr *ifa_maybe = 0;
        u_int af = addr->sa_family;

        if (af >= AF_MAX)
                return (0);
        TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
                struct ifaddr *ifa = ifac->ifa;

                if (ifa->ifa_addr->sa_family != af)
                        continue;
                if (ifa_maybe == 0)
                        ifa_maybe = ifa;
                if (ifa->ifa_netmask == NULL) {
                        if (sa_equal(addr, ifa->ifa_addr) ||
                            (ifa->ifa_dstaddr != NULL &&
                             sa_equal(addr, ifa->ifa_dstaddr)))
                                return (ifa);
                        continue;
                }
                if (ifp->if_flags & IFF_POINTOPOINT) {
                        if (sa_equal(addr, ifa->ifa_dstaddr))
                                return (ifa);
                } else {
                        cp = addr->sa_data;
                        cp2 = ifa->ifa_addr->sa_data;
                        cp3 = ifa->ifa_netmask->sa_data;
                        cplim = ifa->ifa_netmask->sa_len + (char *)ifa->ifa_netmask;
                        for (; cp3 < cplim; cp3++)
                                if ((*cp++ ^ *cp2++) & *cp3)
                                        break;
                        if (cp3 == cplim)
                                return (ifa);
                }
        }
        return (ifa_maybe);
}

/*
 * Default action when installing a route with a Link Level gateway.
 * Lookup an appropriate real ifa to point to.
 * This should be moved to /sys/net/link.c eventually.
 */
static void
link_rtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info)
{
        struct ifaddr *ifa;
        struct sockaddr *dst;
        struct ifnet *ifp;

        if (cmd != RTM_ADD || (ifa = rt->rt_ifa) == NULL ||
            (ifp = ifa->ifa_ifp) == NULL || (dst = rt_key(rt)) == NULL)
                return;
        ifa = ifaof_ifpforaddr(dst, ifp);
        if (ifa != NULL) {
                IFAFREE(rt->rt_ifa);
                IFAREF(ifa);
                rt->rt_ifa = ifa;
                if (ifa->ifa_rtrequest && ifa->ifa_rtrequest != link_rtrequest)
                        ifa->ifa_rtrequest(cmd, rt, info);
        }
}

/*
 * Mark an interface down and notify protocols of
 * the transition.
 * NOTE: must be called at splnet or eqivalent.
 */
void
if_unroute(struct ifnet *ifp, int flag, int fam)
{
        struct ifaddr_container *ifac;

        ifp->if_flags &= ~flag;
        getmicrotime(&ifp->if_lastchange);
        TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
                struct ifaddr *ifa = ifac->ifa;

                if (fam == PF_UNSPEC || (fam == ifa->ifa_addr->sa_family))
                        kpfctlinput(PRC_IFDOWN, ifa->ifa_addr);
        }
        ifq_purge(&ifp->if_snd);
        rt_ifmsg(ifp);
}

/*
 * Mark an interface up and notify protocols of
 * the transition.
 * NOTE: must be called at splnet or eqivalent.
 */
void
if_route(struct ifnet *ifp, int flag, int fam)
{
        struct ifaddr_container *ifac;

        ifq_purge(&ifp->if_snd);
        ifp->if_flags |= flag;
        getmicrotime(&ifp->if_lastchange);
        TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
                struct ifaddr *ifa = ifac->ifa;

                if (fam == PF_UNSPEC || (fam == ifa->ifa_addr->sa_family))
                        kpfctlinput(PRC_IFUP, ifa->ifa_addr);
        }
        rt_ifmsg(ifp);
#ifdef INET6
        in6_if_up(ifp);
#endif
}

/*
 * Mark an interface down and notify protocols of the transition.  An
 * interface going down is also considered to be a synchronizing event.
 * We must ensure that all packet processing related to the interface
 * has completed before we return so e.g. the caller can free the ifnet
 * structure that the mbufs may be referencing.
 *
 * NOTE: must be called at splnet or eqivalent.
 */
void
if_down(struct ifnet *ifp)
{
        if_unroute(ifp, IFF_UP, AF_UNSPEC);
        netmsg_service_sync();
}

/*
 * Mark an interface up and notify protocols of
 * the transition.
 * NOTE: must be called at splnet or eqivalent.
 */
void
if_up(struct ifnet *ifp)
{
        if_route(ifp, IFF_UP, AF_UNSPEC);
}

/*
 * Process a link state change.
 * NOTE: must be called at splsoftnet or equivalent.
 */
void
if_link_state_change(struct ifnet *ifp)
{
        int link_state = ifp->if_link_state;

        rt_ifmsg(ifp);
        devctl_notify("IFNET", ifp->if_xname,
            (link_state == LINK_STATE_UP) ? "LINK_UP" : "LINK_DOWN", NULL);
}

/*
 * Handle interface watchdog timer routines.  Called
 * from softclock, we decrement timers (if set) and
 * call the appropriate interface routine on expiration.
 */
static void
if_slowtimo(void *arg)
{
        struct ifnet *ifp;

        crit_enter();

        TAILQ_FOREACH(ifp, &ifnet, if_link) {
                if (ifp->if_timer == 0 || --ifp->if_timer)
                        continue;
                if (ifp->if_watchdog) {
                        if (lwkt_serialize_try(ifp->if_serializer)) {
                                (*ifp->if_watchdog)(ifp);
                                lwkt_serialize_exit(ifp->if_serializer);
                        } else {
                                /* try again next timeout */
                                ++ifp->if_timer;
                        }
                }
        }

        crit_exit();

        callout_reset(&if_slowtimo_timer, hz / IFNET_SLOWHZ, if_slowtimo, NULL);
}

/*
 * Map interface name to
 * interface structure pointer.
 */
struct ifnet *
ifunit(const char *name)
{
        struct ifnet *ifp;

        /*
         * Search all the interfaces for this name/number
         */

        TAILQ_FOREACH(ifp, &ifnet, if_link) {
                if (strncmp(ifp->if_xname, name, IFNAMSIZ) == 0)
                        break;
        }
        return (ifp);
}


/*
 * Map interface name in a sockaddr_dl to
 * interface structure pointer.
 */
struct ifnet *
if_withname(struct sockaddr *sa)
{
        char ifname[IFNAMSIZ+1];
        struct sockaddr_dl *sdl = (struct sockaddr_dl *)sa;

        if ( (sa->sa_family != AF_LINK) || (sdl->sdl_nlen == 0) ||
             (sdl->sdl_nlen > IFNAMSIZ) )
                return NULL;

        /*
         * ifunit wants a null-terminated name.  It may not be null-terminated
         * in the sockaddr.  We don't want to change the caller's sockaddr,
         * and there might not be room to put the trailing null anyway, so we
         * make a local copy that we know we can null terminate safely.
         */

        bcopy(sdl->sdl_data, ifname, sdl->sdl_nlen);
        ifname[sdl->sdl_nlen] = '\0';
        return ifunit(ifname);
}


/*
 * Interface ioctls.
 */
int
ifioctl(struct socket *so, u_long cmd, caddr_t data, struct ucred *cred)
{
        struct ifnet *ifp;
        struct ifreq *ifr;
        struct ifstat *ifs;
        int error;
        short oif_flags;
        int new_flags;
        size_t namelen, onamelen;
        char new_name[IFNAMSIZ];
        struct ifaddr *ifa;
        struct sockaddr_dl *sdl;

        switch (cmd) {

        case SIOCGIFCONF:
        case OSIOCGIFCONF:
                return (ifconf(cmd, data, cred));
        }
        ifr = (struct ifreq *)data;

        switch (cmd) {
        case SIOCIFCREATE:
        case SIOCIFDESTROY:
                if ((error = priv_check_cred(cred, PRIV_ROOT, 0)) != 0)
                        return (error);
                return ((cmd == SIOCIFCREATE) ?
                        if_clone_create(ifr->ifr_name, sizeof(ifr->ifr_name)) :
                        if_clone_destroy(ifr->ifr_name));

        case SIOCIFGCLONERS:
                return (if_clone_list((struct if_clonereq *)data));
        }

        ifp = ifunit(ifr->ifr_name);
        if (ifp == 0)
                return (ENXIO);
        switch (cmd) {

        case SIOCGIFFLAGS:
                ifr->ifr_flags = ifp->if_flags;
                ifr->ifr_flagshigh = ifp->if_flags >> 16;
                break;

        case SIOCGIFCAP:
                ifr->ifr_reqcap = ifp->if_capabilities;
                ifr->ifr_curcap = ifp->if_capenable;
                break;

        case SIOCGIFMETRIC:
                ifr->ifr_metric = ifp->if_metric;
                break;

        case SIOCGIFMTU:
                ifr->ifr_mtu = ifp->if_mtu;
                break;

        case SIOCGIFPHYS:
                ifr->ifr_phys = ifp->if_physical;
                break;

        case SIOCGIFPOLLCPU:
#ifdef DEVICE_POLLING
                ifr->ifr_pollcpu = ifp->if_poll_cpuid;
#else
                ifr->ifr_pollcpu = -1;
#endif
                break;

        case SIOCSIFPOLLCPU:
#ifdef DEVICE_POLLING
                if ((ifp->if_flags & IFF_POLLING) == 0)
                        ether_pollcpu_register(ifp, ifr->ifr_pollcpu);
#endif
                break;

        case SIOCSIFFLAGS:
                error = priv_check_cred(cred, PRIV_ROOT, 0);
                if (error)
                        return (error);
                new_flags = (ifr->ifr_flags & 0xffff) |
                    (ifr->ifr_flagshigh << 16);
                if (ifp->if_flags & IFF_SMART) {
                        /* Smart drivers twiddle their own routes */
                } else if (ifp->if_flags & IFF_UP &&
                    (new_flags & IFF_UP) == 0) {
                        crit_enter();
                        if_down(ifp);
                        crit_exit();
                } else if (new_flags & IFF_UP &&
                    (ifp->if_flags & IFF_UP) == 0) {
                        crit_enter();
                        if_up(ifp);
                        crit_exit();
                }

#ifdef DEVICE_POLLING
                if ((new_flags ^ ifp->if_flags) & IFF_POLLING) {
                        if (new_flags & IFF_POLLING) {
                                ether_poll_register(ifp);
                        } else {
                                ether_poll_deregister(ifp);
                        }
                }
#endif

                ifp->if_flags = (ifp->if_flags & IFF_CANTCHANGE) |
                        (new_flags &~ IFF_CANTCHANGE);
                if (new_flags & IFF_PPROMISC) {
                        /* Permanently promiscuous mode requested */
                        ifp->if_flags |= IFF_PROMISC;
                } else if (ifp->if_pcount == 0) {
                        ifp->if_flags &= ~IFF_PROMISC;
                }
                if (ifp->if_ioctl) {
                        lwkt_serialize_enter(ifp->if_serializer);
                        ifp->if_ioctl(ifp, cmd, data, cred);
                        lwkt_serialize_exit(ifp->if_serializer);
                }
                getmicrotime(&ifp->if_lastchange);
                break;

        case SIOCSIFCAP:
                error = priv_check_cred(cred, PRIV_ROOT, 0);
                if (error)
                        return (error);
                if (ifr->ifr_reqcap & ~ifp->if_capabilities)
                        return (EINVAL);
                lwkt_serialize_enter(ifp->if_serializer);
                ifp->if_ioctl(ifp, cmd, data, cred);
                lwkt_serialize_exit(ifp->if_serializer);
                break;

        case SIOCSIFNAME:
                error = priv_check_cred(cred, PRIV_ROOT, 0);
                if (error != 0)
                        return (error);
                error = copyinstr(ifr->ifr_data, new_name, IFNAMSIZ, NULL);
                if (error != 0)
                        return (error);
                if (new_name[0] == '\0')
                        return (EINVAL);
                if (ifunit(new_name) != NULL)
                        return (EEXIST);

                EVENTHANDLER_INVOKE(ifnet_detach_event, ifp);

                /* Announce the departure of the interface. */
                rt_ifannouncemsg(ifp, IFAN_DEPARTURE);

                strlcpy(ifp->if_xname, new_name, sizeof(ifp->if_xname));
                ifa = TAILQ_FIRST(&ifp->if_addrheads[mycpuid])->ifa;
                /* XXX IFA_LOCK(ifa); */
                sdl = (struct sockaddr_dl *)ifa->ifa_addr;
                namelen = strlen(new_name);
                onamelen = sdl->sdl_nlen;
                /*
                 * Move the address if needed.  This is safe because we
                 * allocate space for a name of length IFNAMSIZ when we
                 * create this in if_attach().
                 */
                if (namelen != onamelen) {
                        bcopy(sdl->sdl_data + onamelen,
                            sdl->sdl_data + namelen, sdl->sdl_alen);
                }
                bcopy(new_name, sdl->sdl_data, namelen);
                sdl->sdl_nlen = namelen;
                sdl = (struct sockaddr_dl *)ifa->ifa_netmask;
                bzero(sdl->sdl_data, onamelen);
                while (namelen != 0)
                        sdl->sdl_data[--namelen] = 0xff;
                /* XXX IFA_UNLOCK(ifa) */

                EVENTHANDLER_INVOKE(ifnet_attach_event, ifp);

                /* Announce the return of the interface. */
                rt_ifannouncemsg(ifp, IFAN_ARRIVAL);
                break;

        case SIOCSIFMETRIC:
                error = priv_check_cred(cred, PRIV_ROOT, 0);
                if (error)
                        return (error);
                ifp->if_metric = ifr->ifr_metric;
                getmicrotime(&ifp->if_lastchange);
                break;

        case SIOCSIFPHYS:
                error = priv_check_cred(cred, PRIV_ROOT, 0);
                if (error)
                        return error;
                if (!ifp->if_ioctl)
                        return EOPNOTSUPP;
                lwkt_serialize_enter(ifp->if_serializer);
                error = ifp->if_ioctl(ifp, cmd, data, cred);
                lwkt_serialize_exit(ifp->if_serializer);
                if (error == 0)
                        getmicrotime(&ifp->if_lastchange);
                return (error);

        case SIOCSIFMTU:
        {
                u_long oldmtu = ifp->if_mtu;

                error = priv_check_cred(cred, PRIV_ROOT, 0);
                if (error)
                        return (error);
                if (ifp->if_ioctl == NULL)
                        return (EOPNOTSUPP);
                if (ifr->ifr_mtu < IF_MINMTU || ifr->ifr_mtu > IF_MAXMTU)
                        return (EINVAL);
                lwkt_serialize_enter(ifp->if_serializer);
                error = ifp->if_ioctl(ifp, cmd, data, cred);
                lwkt_serialize_exit(ifp->if_serializer);
                if (error == 0) {
                        getmicrotime(&ifp->if_lastchange);
                        rt_ifmsg(ifp);
                }
                /*
                 * If the link MTU changed, do network layer specific procedure.
                 */
                if (ifp->if_mtu != oldmtu) {
#ifdef INET6
                        nd6_setmtu(ifp);
#endif
                }
                return (error);
        }

        case SIOCADDMULTI:
        case SIOCDELMULTI:
                error = priv_check_cred(cred, PRIV_ROOT, 0);
                if (error)
                        return (error);

                /* Don't allow group membership on non-multicast interfaces. */
                if ((ifp->if_flags & IFF_MULTICAST) == 0)
                        return EOPNOTSUPP;

                /* Don't let users screw up protocols' entries. */
                if (ifr->ifr_addr.sa_family != AF_LINK)
                        return EINVAL;

                if (cmd == SIOCADDMULTI) {
                        struct ifmultiaddr *ifma;
                        error = if_addmulti(ifp, &ifr->ifr_addr, &ifma);
                } else {
                        error = if_delmulti(ifp, &ifr->ifr_addr);
                }
                if (error == 0)
                        getmicrotime(&ifp->if_lastchange);
                return error;

        case SIOCSIFPHYADDR:
        case SIOCDIFPHYADDR:
#ifdef INET6
        case SIOCSIFPHYADDR_IN6:
#endif
        case SIOCSLIFPHYADDR:
        case SIOCSIFMEDIA:
        case SIOCSIFGENERIC:
                error = priv_check_cred(cred, PRIV_ROOT, 0);
                if (error)
                        return (error);
                if (ifp->if_ioctl == 0)
                        return (EOPNOTSUPP);
                lwkt_serialize_enter(ifp->if_serializer);
                error = ifp->if_ioctl(ifp, cmd, data, cred);
                lwkt_serialize_exit(ifp->if_serializer);
                if (error == 0)
                        getmicrotime(&ifp->if_lastchange);
                return error;

        case SIOCGIFSTATUS:
                ifs = (struct ifstat *)data;
                ifs->ascii[0] = '\0';

        case SIOCGIFPSRCADDR:
        case SIOCGIFPDSTADDR:
        case SIOCGLIFPHYADDR:
        case SIOCGIFMEDIA:
        case SIOCGIFGENERIC:
                if (ifp->if_ioctl == NULL)
                        return (EOPNOTSUPP);
                lwkt_serialize_enter(ifp->if_serializer);
                error = ifp->if_ioctl(ifp, cmd, data, cred);
                lwkt_serialize_exit(ifp->if_serializer);
                return (error);

        case SIOCSIFLLADDR:
                error = priv_check_cred(cred, PRIV_ROOT, 0);
                if (error)
                        return (error);
                return if_setlladdr(ifp,
                    ifr->ifr_addr.sa_data, ifr->ifr_addr.sa_len);

        default:
                oif_flags = ifp->if_flags;
                if (so->so_proto == 0)
                        return (EOPNOTSUPP);
#ifndef COMPAT_43
                error = so_pru_control(so, cmd, data, ifp);
#else
            {
                int ocmd = cmd;

                switch (cmd) {

                case SIOCSIFDSTADDR:
                case SIOCSIFADDR:
                case SIOCSIFBRDADDR:
                case SIOCSIFNETMASK:
#if BYTE_ORDER != BIG_ENDIAN
                        if (ifr->ifr_addr.sa_family == 0 &&
                            ifr->ifr_addr.sa_len < 16) {
                                ifr->ifr_addr.sa_family = ifr->ifr_addr.sa_len;
                                ifr->ifr_addr.sa_len = 16;
                        }
#else
                        if (ifr->ifr_addr.sa_len == 0)
                                ifr->ifr_addr.sa_len = 16;
#endif
                        break;

                case OSIOCGIFADDR:
                        cmd = SIOCGIFADDR;
                        break;

                case OSIOCGIFDSTADDR:
                        cmd = SIOCGIFDSTADDR;
                        break;

                case OSIOCGIFBRDADDR:
                        cmd = SIOCGIFBRDADDR;
                        break;

                case OSIOCGIFNETMASK:
                        cmd = SIOCGIFNETMASK;
                }
                error =  so_pru_control(so, cmd, data, ifp);
                switch (ocmd) {

                case OSIOCGIFADDR:
                case OSIOCGIFDSTADDR:
                case OSIOCGIFBRDADDR:
                case OSIOCGIFNETMASK:
                        *(u_short *)&ifr->ifr_addr = ifr->ifr_addr.sa_family;

                }
            }
#endif /* COMPAT_43 */

                if ((oif_flags ^ ifp->if_flags) & IFF_UP) {
#ifdef INET6
                        DELAY(100);/* XXX: temporary workaround for fxp issue*/
                        if (ifp->if_flags & IFF_UP) {
                                crit_enter();
                                in6_if_up(ifp);
                                crit_exit();
                        }
#endif
                }
                return (error);

        }
        return (0);
}

/*
 * Set/clear promiscuous mode on interface ifp based on the truth value
 * of pswitch.  The calls are reference counted so that only the first
 * "on" request actually has an effect, as does the final "off" request.
 * Results are undefined if the "off" and "on" requests are not matched.
 */
int
ifpromisc(struct ifnet *ifp, int pswitch)
{
        struct ifreq ifr;
        int error;
        int oldflags;

        oldflags = ifp->if_flags;
        if (ifp->if_flags & IFF_PPROMISC) {
                /* Do nothing if device is in permanently promiscuous mode */
                ifp->if_pcount += pswitch ? 1 : -1;
                return (0);
        }
        if (pswitch) {
                /*
                 * If the device is not configured up, we cannot put it in
                 * promiscuous mode.
                 */
                if ((ifp->if_flags & IFF_UP) == 0)
                        return (ENETDOWN);
                if (ifp->if_pcount++ != 0)
                        return (0);
                ifp->if_flags |= IFF_PROMISC;
                log(LOG_INFO, "%s: promiscuous mode enabled\n",
                    ifp->if_xname);
        } else {
                if (--ifp->if_pcount > 0)
                        return (0);
                ifp->if_flags &= ~IFF_PROMISC;
                log(LOG_INFO, "%s: promiscuous mode disabled\n",
                    ifp->if_xname);
        }
        ifr.ifr_flags = ifp->if_flags;
        ifr.ifr_flagshigh = ifp->if_flags >> 16;
        lwkt_serialize_enter(ifp->if_serializer);
        error = ifp->if_ioctl(ifp, SIOCSIFFLAGS, (caddr_t)&ifr,
                                 (struct ucred *)NULL);
        lwkt_serialize_exit(ifp->if_serializer);
        if (error == 0)
                rt_ifmsg(ifp);
        else
                ifp->if_flags = oldflags;
        return error;
}

/*
 * Return interface configuration
 * of system.  List may be used
 * in later ioctl's (above) to get
 * other information.
 */
static int
ifconf(u_long cmd, caddr_t data, struct ucred *cred)
{
        struct ifconf *ifc = (struct ifconf *)data;
        struct ifnet *ifp;
        struct sockaddr *sa;
        struct ifreq ifr, *ifrp;
        int space = ifc->ifc_len, error = 0;

        ifrp = ifc->ifc_req;
        TAILQ_FOREACH(ifp, &ifnet, if_link) {
                struct ifaddr_container *ifac;
                int addrs;

                if (space <= sizeof ifr)
                        break;

                /*
                 * Zero the stack declared structure first to prevent
                 * memory disclosure.
                 */
                bzero(&ifr, sizeof(ifr));
                if (strlcpy(ifr.ifr_name, ifp->if_xname, sizeof(ifr.ifr_name))
                    >= sizeof(ifr.ifr_name)) {
                        error = ENAMETOOLONG;
                        break;
                }

                addrs = 0;
                TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
                        struct ifaddr *ifa = ifac->ifa;

                        if (space <= sizeof ifr)
                                break;
                        sa = ifa->ifa_addr;
                        if (cred->cr_prison &&
                            prison_if(cred, sa))
                                continue;
                        addrs++;
#ifdef COMPAT_43
                        if (cmd == OSIOCGIFCONF) {
                                struct osockaddr *osa =
                                         (struct osockaddr *)&ifr.ifr_addr;
                                ifr.ifr_addr = *sa;
                                osa->sa_family = sa->sa_family;
                                error = copyout(&ifr, ifrp, sizeof ifr);
                                ifrp++;
                        } else
#endif
                        if (sa->sa_len <= sizeof(*sa)) {
                                ifr.ifr_addr = *sa;
                                error = copyout(&ifr, ifrp, sizeof ifr);
                                ifrp++;
                        } else {
                                if (space < (sizeof ifr) + sa->sa_len -
                                            sizeof(*sa))
                                        break;
                                space -= sa->sa_len - sizeof(*sa);
                                error = copyout(&ifr, ifrp,
                                                sizeof ifr.ifr_name);
                                if (error == 0)
                                        error = copyout(sa, &ifrp->ifr_addr,
                                                        sa->sa_len);
                                ifrp = (struct ifreq *)
                                        (sa->sa_len + (caddr_t)&ifrp->ifr_addr);
                        }
                        if (error)
                                break;
                        space -= sizeof ifr;
                }
                if (error)
                        break;
                if (!addrs) {
                        bzero(&ifr.ifr_addr, sizeof ifr.ifr_addr);
                        error = copyout(&ifr, ifrp, sizeof ifr);
                        if (error)
                                break;
                        space -= sizeof ifr;
                        ifrp++;
                }
        }
        ifc->ifc_len -= space;
        return (error);
}

/*
 * Just like if_promisc(), but for all-multicast-reception mode.
 */
int
if_allmulti(struct ifnet *ifp, int onswitch)
{
        int error = 0;
        struct ifreq ifr;

        crit_enter();

        if (onswitch) {
                if (ifp->if_amcount++ == 0) {
                        ifp->if_flags |= IFF_ALLMULTI;
                        ifr.ifr_flags = ifp->if_flags;
                        ifr.ifr_flagshigh = ifp->if_flags >> 16;
                        lwkt_serialize_enter(ifp->if_serializer);
                        error = ifp->if_ioctl(ifp, SIOCSIFFLAGS, (caddr_t)&ifr,
                                              (struct ucred *)NULL);
                        lwkt_serialize_exit(ifp->if_serializer);
                }
        } else {
                if (ifp->if_amcount > 1) {
                        ifp->if_amcount--;
                } else {
                        ifp->if_amcount = 0;
                        ifp->if_flags &= ~IFF_ALLMULTI;
                        ifr.ifr_flags = ifp->if_flags;
                        ifr.ifr_flagshigh = ifp->if_flags >> 16;
                        lwkt_serialize_enter(ifp->if_serializer);
                        error = ifp->if_ioctl(ifp, SIOCSIFFLAGS, (caddr_t)&ifr,
                                              (struct ucred *)NULL);
                        lwkt_serialize_exit(ifp->if_serializer);
                }
        }

        crit_exit();

        if (error == 0)
                rt_ifmsg(ifp);
        return error;
}

/*
 * Add a multicast listenership to the interface in question.
 * The link layer provides a routine which converts
 */
int
if_addmulti(
        struct ifnet *ifp,      /* interface to manipulate */
        struct sockaddr *sa,    /* address to add */
        struct ifmultiaddr **retifma)
{
        struct sockaddr *llsa, *dupsa;
        int error;
        struct ifmultiaddr *ifma;

        /*
         * If the matching multicast address already exists
         * then don't add a new one, just add a reference
         */
        LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
                if (sa_equal(sa, ifma->ifma_addr)) {
                        ifma->ifma_refcount++;
                        if (retifma)
                                *retifma = ifma;
                        return 0;
                }
        }

        /*
         * Give the link layer a chance to accept/reject it, and also
         * find out which AF_LINK address this maps to, if it isn't one
         * already.
         */
        if (ifp->if_resolvemulti) {
                lwkt_serialize_enter(ifp->if_serializer);
                error = ifp->if_resolvemulti(ifp, &llsa, sa);
                lwkt_serialize_exit(ifp->if_serializer);
                if (error) 
                        return error;
        } else {
                llsa = 0;
        }

        MALLOC(ifma, struct ifmultiaddr *, sizeof *ifma, M_IFMADDR, M_WAITOK);
        MALLOC(dupsa, struct sockaddr *, sa->sa_len, M_IFMADDR, M_WAITOK);
        bcopy(sa, dupsa, sa->sa_len);

        ifma->ifma_addr = dupsa;
        ifma->ifma_lladdr = llsa;
        ifma->ifma_ifp = ifp;
        ifma->ifma_refcount = 1;
        ifma->ifma_protospec = 0;
        rt_newmaddrmsg(RTM_NEWMADDR, ifma);

        /*
         * Some network interfaces can scan the address list at
         * interrupt time; lock them out.
         */
        crit_enter();
        LIST_INSERT_HEAD(&ifp->if_multiaddrs, ifma, ifma_link);
        crit_exit();
        *retifma = ifma;

        if (llsa != 0) {
                LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
                        if (sa_equal(ifma->ifma_addr, llsa))
                                break;
                }
                if (ifma) {
                        ifma->ifma_refcount++;
                } else {
                        MALLOC(ifma, struct ifmultiaddr *, sizeof *ifma,
                               M_IFMADDR, M_WAITOK);
                        MALLOC(dupsa, struct sockaddr *, llsa->sa_len,
                               M_IFMADDR, M_WAITOK);
                        bcopy(llsa, dupsa, llsa->sa_len);
                        ifma->ifma_addr = dupsa;
                        ifma->ifma_ifp = ifp;
                        ifma->ifma_refcount = 1;
                        crit_enter();
                        LIST_INSERT_HEAD(&ifp->if_multiaddrs, ifma, ifma_link);
                        crit_exit();
                }
        }
        /*
         * We are certain we have added something, so call down to the
         * interface to let them know about it.
         */
        crit_enter();
        lwkt_serialize_enter(ifp->if_serializer);
        ifp->if_ioctl(ifp, SIOCADDMULTI, 0, (struct ucred *)NULL);
        lwkt_serialize_exit(ifp->if_serializer);
        crit_exit();

        return 0;
}

/*
 * Remove a reference to a multicast address on this interface.  Yell
 * if the request does not match an existing membership.
 */
int
if_delmulti(struct ifnet *ifp, struct sockaddr *sa)
{
        struct ifmultiaddr *ifma;

        LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link)
                if (sa_equal(sa, ifma->ifma_addr))
                        break;
        if (ifma == 0)
                return ENOENT;

        if (ifma->ifma_refcount > 1) {
                ifma->ifma_refcount--;
                return 0;
        }

        rt_newmaddrmsg(RTM_DELMADDR, ifma);
        sa = ifma->ifma_lladdr;
        crit_enter();
        LIST_REMOVE(ifma, ifma_link);
        /*
         * Make sure the interface driver is notified
         * in the case of a link layer mcast group being left.
         */
        if (ifma->ifma_addr->sa_family == AF_LINK && sa == 0) {
                lwkt_serialize_enter(ifp->if_serializer);
                ifp->if_ioctl(ifp, SIOCDELMULTI, 0, (struct ucred *)NULL);
                lwkt_serialize_exit(ifp->if_serializer);
        }
        crit_exit();
        kfree(ifma->ifma_addr, M_IFMADDR);
        kfree(ifma, M_IFMADDR);
        if (sa == 0)
                return 0;

        /*
         * Now look for the link-layer address which corresponds to
         * this network address.  It had been squirreled away in
         * ifma->ifma_lladdr for this purpose (so we don't have
         * to call ifp->if_resolvemulti() again), and we saved that
         * value in sa above.  If some nasty deleted the
         * link-layer address out from underneath us, we can deal because
         * the address we stored was is not the same as the one which was
         * in the record for the link-layer address.  (So we don't complain
         * in that case.)
         */
        LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link)
                if (sa_equal(sa, ifma->ifma_addr))
                        break;
        if (ifma == 0)
                return 0;

        if (ifma->ifma_refcount > 1) {
                ifma->ifma_refcount--;
                return 0;
        }

        crit_enter();
        lwkt_serialize_enter(ifp->if_serializer);
        LIST_REMOVE(ifma, ifma_link);
        ifp->if_ioctl(ifp, SIOCDELMULTI, 0, (struct ucred *)NULL);
        lwkt_serialize_exit(ifp->if_serializer);
        crit_exit();
        kfree(ifma->ifma_addr, M_IFMADDR);
        kfree(sa, M_IFMADDR);
        kfree(ifma, M_IFMADDR);

        return 0;
}

/*
 * Set the link layer address on an interface.
 *
 * At this time we only support certain types of interfaces,
 * and we don't allow the length of the address to change.
 */
int
if_setlladdr(struct ifnet *ifp, const u_char *lladdr, int len)
{
        struct sockaddr_dl *sdl;
        struct ifreq ifr;

        sdl = IF_LLSOCKADDR(ifp);
        if (sdl == NULL)
                return (EINVAL);
        if (len != sdl->sdl_alen)       /* don't allow length to change */
                return (EINVAL);
        switch (ifp->if_type) {
        case IFT_ETHER:                 /* these types use struct arpcom */
        case IFT_XETHER:
        case IFT_L2VLAN:
                bcopy(lladdr, ((struct arpcom *)ifp->if_softc)->ac_enaddr, len);
                bcopy(lladdr, LLADDR(sdl), len);
                break;
        default:
                return (ENODEV);
        }
        /*
         * If the interface is already up, we need
         * to re-init it in order to reprogram its
         * address filter.
         */
        lwkt_serialize_enter(ifp->if_serializer);
        if ((ifp->if_flags & IFF_UP) != 0) {
                struct ifaddr_container *ifac;

                ifp->if_flags &= ~IFF_UP;
                ifr.ifr_flags = ifp->if_flags;
                ifr.ifr_flagshigh = ifp->if_flags >> 16;
                ifp->if_ioctl(ifp, SIOCSIFFLAGS, (caddr_t)&ifr,
                              (struct ucred *)NULL);
                ifp->if_flags |= IFF_UP;
                ifr.ifr_flags = ifp->if_flags;
                ifr.ifr_flagshigh = ifp->if_flags >> 16;
                ifp->if_ioctl(ifp, SIOCSIFFLAGS, (caddr_t)&ifr,
                                 (struct ucred *)NULL);
#ifdef INET
                /*
                 * Also send gratuitous ARPs to notify other nodes about
                 * the address change.
                 */
                TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
                        struct ifaddr *ifa = ifac->ifa;

                        if (ifa->ifa_addr != NULL &&
                            ifa->ifa_addr->sa_family == AF_INET)
                                arp_ifinit(ifp, ifa);
                }
#endif
        }
        lwkt_serialize_exit(ifp->if_serializer);
        return (0);
}

struct ifmultiaddr *
ifmaof_ifpforaddr(struct sockaddr *sa, struct ifnet *ifp)
{
        struct ifmultiaddr *ifma;

        LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link)
                if (sa_equal(ifma->ifma_addr, sa))
                        break;

        return ifma;
}

/*
 * This function locates the first real ethernet MAC from a network
 * card and loads it into node, returning 0 on success or ENOENT if
 * no suitable interfaces were found.  It is used by the uuid code to
 * generate a unique 6-byte number.
 */
int
if_getanyethermac(uint16_t *node, int minlen)
{
        struct ifnet *ifp;
        struct sockaddr_dl *sdl;

        TAILQ_FOREACH(ifp, &ifnet, if_link) {
                if (ifp->if_type != IFT_ETHER)
                        continue;
                sdl = IF_LLSOCKADDR(ifp);
                if (sdl->sdl_alen < minlen)
                        continue;
                bcopy(((struct arpcom *)ifp->if_softc)->ac_enaddr, node,
                      minlen);
                return(0);
        }
        return (ENOENT);
}

/*
 * The name argument must be a pointer to storage which will last as
 * long as the interface does.  For physical devices, the result of
 * device_get_name(dev) is a good choice and for pseudo-devices a
 * static string works well.
 */
void
if_initname(struct ifnet *ifp, const char *name, int unit)
{
        ifp->if_dname = name;
        ifp->if_dunit = unit;
        if (unit != IF_DUNIT_NONE)
                ksnprintf(ifp->if_xname, IFNAMSIZ, "%s%d", name, unit);
        else
                strlcpy(ifp->if_xname, name, IFNAMSIZ);
}

int
if_printf(struct ifnet *ifp, const char *fmt, ...)
{
        __va_list ap;
        int retval;

        retval = kprintf("%s: ", ifp->if_xname);
        __va_start(ap, fmt);
        retval += kvprintf(fmt, ap);
        __va_end(ap);
        return (retval);
}

void
ifq_set_classic(struct ifaltq *ifq)
{
        ifq->altq_enqueue = ifq_classic_enqueue;
        ifq->altq_dequeue = ifq_classic_dequeue;
        ifq->altq_request = ifq_classic_request;
}

int
ifq_classic_enqueue(struct ifaltq *ifq, struct mbuf *m,
                    struct altq_pktattr *pa __unused)
{
        logifq(enqueue, ifq);
        if (IF_QFULL(ifq)) {
                m_freem(m);
                return(ENOBUFS);
        } else {
                IF_ENQUEUE(ifq, m);
                return(0);
        }       
}

struct mbuf *
ifq_classic_dequeue(struct ifaltq *ifq, struct mbuf *mpolled, int op)
{
        struct mbuf *m;

        switch (op) {
        case ALTDQ_POLL:
                IF_POLL(ifq, m);
                break;
        case ALTDQ_REMOVE:
                logifq(dequeue, ifq);
                IF_DEQUEUE(ifq, m);
                break;
        default:
                panic("unsupported ALTQ dequeue op: %d", op);
        }
        KKASSERT(mpolled == NULL || mpolled == m);
        return(m);
}

int
ifq_classic_request(struct ifaltq *ifq, int req, void *arg)
{
        switch (req) {
        case ALTRQ_PURGE:
                IF_DRAIN(ifq);
                break;
        default:
                panic("unsupported ALTQ request: %d", req);
        }
        return(0);
}

int
ifq_dispatch(struct ifnet *ifp, struct mbuf *m, struct altq_pktattr *pa)
{
        struct ifaltq *ifq = &ifp->if_snd;
        int running = 0, error, start = 0;

        ASSERT_NOT_SERIALIZED(ifp->if_serializer);

        ALTQ_LOCK(ifq);
        error = ifq_enqueue_locked(ifq, m, pa);
        if (error) {
                ALTQ_UNLOCK(ifq);
                return error;
        }
        if (!ifq->altq_started) {
                /*
                 * Hold the interlock of ifnet.if_start
                 */
                ifq->altq_started = 1;
                start = 1;
        }
        ALTQ_UNLOCK(ifq);

        ifp->if_obytes += m->m_pkthdr.len;
        if (m->m_flags & M_MCAST)
                ifp->if_omcasts++;

        if (!start) {
                logifstart(avoid, ifp);
                return 0;
        }

        if (ifq_dispatch_schedonly) {
                /*
                 * Always schedule ifnet.if_start on ifnet's CPU,
                 * short circuit the rest of this function.
                 */
                logifstart(sched, ifp);
                if_start_schedule(ifp);
                return 0;
        }

        /*
         * Try to do direct ifnet.if_start first, if there is
         * contention on ifnet's serializer, ifnet.if_start will
         * be scheduled on ifnet's CPU.
         */
        if (!lwkt_serialize_try(ifp->if_serializer)) {
                /*
                 * ifnet serializer contention happened,
                 * ifnet.if_start is scheduled on ifnet's
                 * CPU, and we keep going.
                 */
                logifstart(contend_sched, ifp);
                if_start_schedule(ifp);
                return 0;
        }

        if ((ifp->if_flags & IFF_OACTIVE) == 0) {
                logifstart(run, ifp);
                ifp->if_start(ifp);
                if ((ifp->if_flags &
                     (IFF_OACTIVE | IFF_RUNNING)) == IFF_RUNNING)
                        running = 1;
        }

        lwkt_serialize_exit(ifp->if_serializer);

        if (ifq_dispatch_schednochk || if_start_need_schedule(ifq, running)) {
                /*
                 * More data need to be transmitted, ifnet.if_start is
                 * scheduled on ifnet's CPU, and we keep going.
                 * NOTE: ifnet.if_start interlock is not released.
                 */
                logifstart(sched, ifp);
                if_start_schedule(ifp);
        }
        return 0;
}

void *
ifa_create(int size, int flags)
{
        struct ifaddr *ifa;
        int i;

        KASSERT(size >= sizeof(*ifa), ("ifaddr size too small\n"));

        ifa = kmalloc(size, M_IFADDR, flags | M_ZERO);
        if (ifa == NULL)
                return NULL;

        ifa->ifa_containers = kmalloc(ncpus * sizeof(struct ifaddr_container),
                                      M_IFADDR, M_WAITOK | M_ZERO);
        ifa->ifa_ncnt = ncpus;
        for (i = 0; i < ncpus; ++i) {
                struct ifaddr_container *ifac = &ifa->ifa_containers[i];

                ifac->ifa_magic = IFA_CONTAINER_MAGIC;
                ifac->ifa = ifa;
                ifac->ifa_refcnt = 1;
        }
#ifdef IFADDR_DEBUG
        kprintf("alloc ifa %p %d\n", ifa, size);
#endif
        return ifa;
}

void
ifac_free(struct ifaddr_container *ifac, int cpu_id)
{
        struct ifaddr *ifa = ifac->ifa;

        KKASSERT(ifac->ifa_magic == IFA_CONTAINER_MAGIC);
        KKASSERT(ifac->ifa_refcnt == 0);
        KASSERT(ifac->ifa_listmask == 0,
                ("ifa is still on %#x lists\n", ifac->ifa_listmask));

        ifac->ifa_magic = IFA_CONTAINER_DEAD;

#ifdef IFADDR_DEBUG_VERBOSE
        kprintf("try free ifa %p cpu_id %d\n", ifac->ifa, cpu_id);
#endif

        KASSERT(ifa->ifa_ncnt > 0 && ifa->ifa_ncnt <= ncpus,
                ("invalid # of ifac, %d\n", ifa->ifa_ncnt));
        if (atomic_fetchadd_int(&ifa->ifa_ncnt, -1) == 1) {
#ifdef IFADDR_DEBUG
                kprintf("free ifa %p\n", ifa);
#endif
                kfree(ifa->ifa_containers, M_IFADDR);
                kfree(ifa, M_IFADDR);
        }
}

static void
ifa_iflink_dispatch(struct netmsg *nmsg)
{
        struct netmsg_ifaddr *msg = (struct netmsg_ifaddr *)nmsg;
        struct ifaddr *ifa = msg->ifa;
        struct ifnet *ifp = msg->ifp;
        int cpu = mycpuid;
        struct ifaddr_container *ifac;

        crit_enter();

        ifac = &ifa->ifa_containers[cpu];
        ASSERT_IFAC_VALID(ifac);
        KASSERT((ifac->ifa_listmask & IFA_LIST_IFADDRHEAD) == 0,
                ("ifaddr is on if_addrheads\n"));

        ifac->ifa_listmask |= IFA_LIST_IFADDRHEAD;
        if (msg->tail)
                TAILQ_INSERT_TAIL(&ifp->if_addrheads[cpu], ifac, ifa_link);
        else
                TAILQ_INSERT_HEAD(&ifp->if_addrheads[cpu], ifac, ifa_link);

        crit_exit();

        ifa_forwardmsg(&nmsg->nm_lmsg, cpu + 1);
}

void
ifa_iflink(struct ifaddr *ifa, struct ifnet *ifp, int tail)
{
        struct netmsg_ifaddr msg;

        netmsg_init(&msg.netmsg, &curthread->td_msgport, 0,
                    ifa_iflink_dispatch);
        msg.ifa = ifa;
        msg.ifp = ifp;
        msg.tail = tail;

        ifa_domsg(&msg.netmsg.nm_lmsg, 0);
}

static void
ifa_ifunlink_dispatch(struct netmsg *nmsg)
{
        struct netmsg_ifaddr *msg = (struct netmsg_ifaddr *)nmsg;
        struct ifaddr *ifa = msg->ifa;
        struct ifnet *ifp = msg->ifp;
        int cpu = mycpuid;
        struct ifaddr_container *ifac;

        crit_enter();

        ifac = &ifa->ifa_containers[cpu];
        ASSERT_IFAC_VALID(ifac);
        KASSERT(ifac->ifa_listmask & IFA_LIST_IFADDRHEAD,
                ("ifaddr is not on if_addrhead\n"));

        TAILQ_REMOVE(&ifp->if_addrheads[cpu], ifac, ifa_link);
        ifac->ifa_listmask &= ~IFA_LIST_IFADDRHEAD;

        crit_exit();

        ifa_forwardmsg(&nmsg->nm_lmsg, cpu + 1);
}

void
ifa_ifunlink(struct ifaddr *ifa, struct ifnet *ifp)
{
        struct netmsg_ifaddr msg;

        netmsg_init(&msg.netmsg, &curthread->td_msgport, 0,
                    ifa_ifunlink_dispatch);
        msg.ifa = ifa;
        msg.ifp = ifp;

        ifa_domsg(&msg.netmsg.nm_lmsg, 0);
}

static void
ifa_destroy_dispatch(struct netmsg *nmsg)
{
        struct netmsg_ifaddr *msg = (struct netmsg_ifaddr *)nmsg;

        IFAFREE(msg->ifa);
        ifa_forwardmsg(&nmsg->nm_lmsg, mycpuid + 1);
}

void
ifa_destroy(struct ifaddr *ifa)
{
        struct netmsg_ifaddr msg;

        netmsg_init(&msg.netmsg, &curthread->td_msgport, 0,
                    ifa_destroy_dispatch);
        msg.ifa = ifa;

        ifa_domsg(&msg.netmsg.nm_lmsg, 0);
}

struct lwkt_port *
ifnet_portfn(int cpu)
{
        return &ifnet_threads[cpu].td_msgport;
}

void
ifnet_forwardmsg(struct lwkt_msg *lmsg, int next_cpu)
{
        KKASSERT(next_cpu > mycpuid && next_cpu <= ncpus);

        if (next_cpu < ncpus)
                lwkt_forwardmsg(ifnet_portfn(next_cpu), lmsg);
        else
                lwkt_replymsg(lmsg, 0);
}

int
ifnet_domsg(struct lwkt_msg *lmsg, int cpu)
{
        KKASSERT(cpu < ncpus);
        return lwkt_domsg(ifnet_portfn(cpu), lmsg, 0);
}

void
ifnet_sendmsg(struct lwkt_msg *lmsg, int cpu)
{
        KKASSERT(cpu < ncpus);
        lwkt_sendmsg(ifnet_portfn(cpu), lmsg);
}

static void
ifnetinit(void *dummy __unused)
{
        int i;

        for (i = 0; i < ncpus; ++i) {
                struct thread *thr = &ifnet_threads[i];

                lwkt_create(netmsg_service_loop, &ifnet_mpsafe_thread, NULL,
                            thr, TDF_NETWORK | TDF_MPSAFE, i, "ifnet %d", i);
                netmsg_service_port_init(&thr->td_msgport);
        }
}