/*      $NetBSD: if_arp.c,v 1.320 2026/05/29 02:45:14 ozaki-r Exp $     */

/*
 * Copyright (c) 1998, 2000, 2008 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Public Access Networks Corporation ("Panix").  It was developed under
 * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*
 * Copyright (c) 1982, 1986, 1988, 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. 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_ether.c  8.2 (Berkeley) 9/26/94
 */

/*
 * Ethernet address resolution protocol.
 * TODO:
 *      add "inuse/lock" bit (or ref. count) along with valid bit
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.320 2026/05/29 02:45:14 ozaki-r Exp $");

#ifdef _KERNEL_OPT
#include "opt_ddb.h"
#include "opt_inet.h"
#include "opt_net_mpsafe.h"
#endif

#ifdef INET

#include "arp.h"
#include "bridge.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/kmem.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/timetc.h>
#include <sys/kernel.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/syslog.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/domain.h>
#include <sys/sysctl.h>
#include <sys/socketvar.h>
#include <sys/percpu.h>
#include <sys/cprng.h>
#include <sys/kmem.h>

#include <net/ethertypes.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/if_ether.h>
#include <net/if_llatbl.h>
#include <net/nd.h>
#include <net/route.h>
#include <net/net_stats.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/if_inarp.h>

#include "arcnet.h"
#if NARCNET > 0
#include <net/if_arc.h>
#endif
#include "carp.h"
#if NCARP > 0
#include <netinet/ip_carp.h>
#endif

/*
 * ARP trailer negotiation.  Trailer protocol is not IP specific,
 * but ARP request/response use IP addresses.
 */
#define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL

/* timers */
static int arp_reachable = REACHABLE_TIME;
static int arp_retrans = RETRANS_TIMER;
static int arp_perform_nud = 1;

static bool arp_nud_enabled(struct ifnet *);
static unsigned int arp_llinfo_reachable(struct ifnet *);
static unsigned int arp_llinfo_retrans(struct ifnet *);
static union l3addr *arp_llinfo_holdsrc(struct llentry *, union l3addr *);
static void arp_llinfo_output(struct ifnet *, const union l3addr *,
    const union l3addr *, const uint8_t *, const union l3addr *);
static void arp_llinfo_missed(struct ifnet *, const union l3addr *,
    int16_t, struct mbuf *);
static void arp_free(struct llentry *, int);

static struct nd_domain arp_nd_domain = {
        .nd_family = AF_INET,
        .nd_delay = 5,          /* delay first probe time 5 second */
        .nd_mmaxtries = 3,      /* maximum broadcast query */
        .nd_umaxtries = 3,      /* maximum unicast query */
        .nd_retransmultiple = BACKOFF_MULTIPLE,
        .nd_maxretrans = MAX_RETRANS_TIMER,
        .nd_maxnudhint = 0,     /* max # of subsequent upper layer hints */
        .nd_maxqueuelen = 1,    /* max # of packets in unresolved ND entries */
        .nd_gctimer = 24*60*60, /* stale neighbor GC timer duration */
        .nd_nud_enabled = arp_nud_enabled,
        .nd_reachable = arp_llinfo_reachable,
        .nd_retrans = arp_llinfo_retrans,
        .nd_holdsrc = arp_llinfo_holdsrc,
        .nd_output = arp_llinfo_output,
        .nd_missed = arp_llinfo_missed,
        .nd_free = arp_free,
};

int ip_dad_count = PROBE_NUM;
#ifdef ARP_DEBUG
int arp_debug = 1;
#else
int arp_debug = 0;
#endif

static void arp_init(void);
static void arp_dad_init(void);

static void arprequest(struct ifnet *,
    const struct in_addr *, const struct in_addr *,
    const uint8_t *, const uint8_t *);
static void arpannounce1(struct ifaddr *);
static struct sockaddr *arp_setgate(struct rtentry *, struct sockaddr *,
    const struct sockaddr *);
static struct llentry *arpcreate(struct ifnet *,
    const struct in_addr *, const struct sockaddr *, int);
static void in_arpinput(struct mbuf *);
static void in_revarpinput(struct mbuf *);
static void revarprequest(struct ifnet *);

static void arp_drainstub(void);

struct dadq;
static void arp_dad_timer(struct dadq *);
static void arp_dad_start(struct ifaddr *);
static void arp_dad_stop(struct ifaddr *);
static void arp_dad_duplicated(struct ifaddr *, const struct sockaddr_dl *);

#define ARP_MAXQLEN     50
pktqueue_t *            arp_pktq                __read_mostly;

static int useloopback = 1;     /* use loopback interface for local traffic */

static percpu_t *arpstat_percpu;

#define ARP_STAT_GETREF()       _NET_STAT_GETREF(arpstat_percpu)
#define ARP_STAT_PUTREF()       _NET_STAT_PUTREF(arpstat_percpu)

#define ARP_STATINC(x)          _NET_STATINC(arpstat_percpu, x)
#define ARP_STATADD(x, v)       _NET_STATADD(arpstat_percpu, x, v)

/* revarp state */
static struct in_addr myip, srv_ip;
static int myip_initialized = 0;
static int revarp_in_progress = 0;
static struct ifnet *myip_ifp = NULL;

static int arp_drainwanted;

static int log_movements = 0;
static int log_permanent_modify = 1;
static int log_wrong_iface = 1;

DOMAIN_DEFINE(arpdomain);       /* forward declare and add to link set */

static void
arp_fasttimo(void)
{
        if (arp_drainwanted) {
                arp_drain();
                arp_drainwanted = 0;
        }
}

static const struct protosw arpsw[] = {
        {
                .pr_type = 0,
                .pr_domain = &arpdomain,
                .pr_protocol = 0,
                .pr_flags = 0,
                .pr_input = 0,
                .pr_ctlinput = 0,
                .pr_ctloutput = 0,
                .pr_usrreqs = 0,
                .pr_init = arp_init,
                .pr_fasttimo = arp_fasttimo,
                .pr_slowtimo = 0,
                .pr_drain = arp_drainstub,
        }
};

struct domain arpdomain = {
        .dom_family = PF_ARP,
        .dom_name = "arp",
        .dom_protosw = arpsw,
        .dom_protoswNPROTOSW = &arpsw[__arraycount(arpsw)],
#ifdef MBUFTRACE
        .dom_mowner = MOWNER_INIT("internet", "arp"),
#endif
};

static void sysctl_net_inet_arp_setup(struct sysctllog **);

void
arp_init(void)
{

        arp_pktq = pktq_create(ARP_MAXQLEN, arpintr, NULL);
        KASSERT(arp_pktq != NULL);

        sysctl_net_inet_arp_setup(NULL);
        arpstat_percpu = percpu_alloc(sizeof(uint64_t) * ARP_NSTATS);

#ifdef MBUFTRACE
        MOWNER_ATTACH(&arpdomain.dom_mowner);
#endif

        nd_attach_domain(&arp_nd_domain);
        arp_dad_init();
}

static void
arp_drainstub(void)
{
        arp_drainwanted = 1;
}

/*
 * ARP protocol drain routine.  Called when memory is in short supply.
 * Called at splvm();  don't acquire softnet_lock as can be called from
 * hardware interrupt handlers.
 */
void
arp_drain(void)
{

        lltable_drain(AF_INET);
}

/*
 * We set the gateway for RTF_CLONING routes to a "prototype"
 * link-layer sockaddr whose interface type (if_type) and interface
 * index (if_index) fields are prepared.
 */
static struct sockaddr *
arp_setgate(struct rtentry *rt, struct sockaddr *gate,
    const struct sockaddr *netmask)
{
        const struct ifnet *ifp = rt->rt_ifp;
        uint8_t namelen = strlen(ifp->if_xname);
        uint8_t addrlen = ifp->if_addrlen;

        /*
         * XXX: If this is a manually added route to interface
         * such as older version of routed or gated might provide,
         * restore cloning bit.
         */
        if ((rt->rt_flags & RTF_HOST) == 0 && netmask != NULL &&
            satocsin(netmask)->sin_addr.s_addr != 0xffffffff)
                rt->rt_flags |= RTF_CONNECTED;

        if ((rt->rt_flags & (RTF_CONNECTED | RTF_LOCAL))) {
                union {
                        struct sockaddr sa;
                        struct sockaddr_storage ss;
                        struct sockaddr_dl sdl;
                } u;
                /*
                 * Case 1: This route should come from a route to iface.
                 */
                sockaddr_dl_init(&u.sdl, sizeof(u.ss),
                    ifp->if_index, ifp->if_type, NULL, namelen, NULL, addrlen);
                rt_setgate(rt, &u.sa);
                gate = rt->rt_gateway;
        }
        return gate;
}

/*
 * Parallel to llc_rtrequest.
 */
void
arp_rtrequest(int req, struct rtentry *rt, const struct rt_addrinfo *info)
{
        struct sockaddr *gate = rt->rt_gateway;
        struct in_ifaddr *ia;
        struct ifaddr *ifa;
        struct ifnet *ifp = rt->rt_ifp;
        int bound;
        int s;

        if (req == RTM_LLINFO_UPD) {
                if ((ifa = info->rti_ifa) != NULL)
                        arpannounce1(ifa);
                return;
        }

        if ((rt->rt_flags & RTF_GATEWAY) != 0) {
                if (req != RTM_ADD)
                        return;

                /*
                 * linklayers with particular link MTU limitation.
                 */
                switch(ifp->if_type) {
#if NARCNET > 0
                case IFT_ARCNET:
                    {
                        int arcipifmtu;

                        if (ifp->if_flags & IFF_LINK0)
                                arcipifmtu = arc_ipmtu;
                        else
                                arcipifmtu = ARCMTU;
                        if (ifp->if_mtu > arcipifmtu)
                                rt->rt_rmx.rmx_mtu = arcipifmtu;
                        break;
                    }
#endif
                }
                return;
        }

        switch (req) {
        case RTM_SETGATE:
                gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]);
                break;
        case RTM_ADD:
                gate = arp_setgate(rt, gate, info->rti_info[RTAX_NETMASK]);
                if (gate == NULL) {
                        log(LOG_ERR, "%s: arp_setgate failed\n", __func__);
                        break;
                }
                if ((rt->rt_flags & RTF_CONNECTED) ||
                    (rt->rt_flags & RTF_LOCAL)) {
                        /*
                         * linklayers with particular link MTU limitation.
                         */
                        switch (ifp->if_type) {
#if NARCNET > 0
                        case IFT_ARCNET:
                            {
                                int arcipifmtu;
                                if (ifp->if_flags & IFF_LINK0)
                                        arcipifmtu = arc_ipmtu;
                                else
                                        arcipifmtu = ARCMTU;

                                if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0 &&
                                    (rt->rt_rmx.rmx_mtu > arcipifmtu ||
                                     (rt->rt_rmx.rmx_mtu == 0 &&
                                      ifp->if_mtu > arcipifmtu)))
                                        rt->rt_rmx.rmx_mtu = arcipifmtu;
                                break;
                            }
#endif
                        }
                        if (rt->rt_flags & RTF_CONNECTED)
                                break;
                }

                bound = curlwp_bind();
                /* Announce a new entry if requested. */
                if (rt->rt_flags & RTF_ANNOUNCE) {
                        struct psref psref;
                        ia = in_get_ia_on_iface_psref(
                            satocsin(rt_getkey(rt))->sin_addr, ifp, &psref);
                        if (ia != NULL) {
                                arpannounce(ifp, &ia->ia_ifa,
                                    CLLADDR(satocsdl(gate)));
                                ia4_release(ia, &psref);
                        }
                }

                if (gate->sa_family != AF_LINK ||
                    gate->sa_len < sockaddr_dl_measure(0, ifp->if_addrlen)) {
                        log(LOG_DEBUG, "%s: bad gateway value\n", __func__);
                        goto out;
                }

                satosdl(gate)->sdl_type = ifp->if_type;
                satosdl(gate)->sdl_index = ifp->if_index;

                /*
                 * If the route is for a broadcast address mark it as such.
                 * This way we can avoid an expensive call to in_broadcast()
                 * in ip_output() most of the time (because the route passed
                 * to ip_output() is almost always a host route).
                 */
                if (rt->rt_flags & RTF_HOST &&
                    !(rt->rt_flags & RTF_BROADCAST) &&
                    in_broadcast(satocsin(rt_getkey(rt))->sin_addr, rt->rt_ifp))
                        rt->rt_flags |= RTF_BROADCAST;
                /* There is little point in resolving the broadcast address */
                if (rt->rt_flags & RTF_BROADCAST)
                        goto out;

                /*
                 * When called from rt_ifa_addlocal, we cannot depend on that
                 * the address (rt_getkey(rt)) exits in the address list of the
                 * interface. So check RTF_LOCAL instead.
                 */
                if (rt->rt_flags & RTF_LOCAL) {
                        if (useloopback) {
                                rt->rt_ifp = lo0ifp;
                                rt->rt_rmx.rmx_mtu = 0;
                        }
                        goto out;
                }

                s = pserialize_read_enter();
                ia = in_get_ia_on_iface(satocsin(rt_getkey(rt))->sin_addr, ifp);
                if (ia == NULL) {
                        pserialize_read_exit(s);
                        goto out;
                }

                if (useloopback) {
                        rt->rt_ifp = lo0ifp;
                        rt->rt_rmx.rmx_mtu = 0;
                }
                rt->rt_flags |= RTF_LOCAL;

                if (ISSET(info->rti_flags, RTF_DONTCHANGEIFA)) {
                        pserialize_read_exit(s);
                        goto out;
                }
                /*
                 * make sure to set rt->rt_ifa to the interface
                 * address we are using, otherwise we will have trouble
                 * with source address selection.
                 */
                ifa = &ia->ia_ifa;
                if (ifa != rt->rt_ifa)
                        /* Assume it doesn't sleep */
                        rt_replace_ifa(rt, ifa);
                pserialize_read_exit(s);
        out:
                curlwp_bindx(bound);
                break;
        }
}

/*
 * Broadcast an ARP request. Caller specifies:
 *      - arp header source ip address
 *      - arp header target ip address
 *      - arp header source ethernet address
 */
static void
arprequest(struct ifnet *ifp,
    const struct in_addr *sip, const struct in_addr *tip,
    const uint8_t *saddr, const uint8_t *taddr)
{
        struct mbuf *m;
        struct arphdr *ah;
        struct sockaddr sa;
        net_stat_ref_t arps;

        KASSERT(sip != NULL);
        KASSERT(tip != NULL);
        KASSERT(saddr != NULL);

        if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
                return;
        MCLAIM(m, &arpdomain.dom_mowner);
        switch (ifp->if_type) {
        case IFT_IEEE1394:
                m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) +
                    ifp->if_addrlen;
                break;
        default:
                m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) +
                    2 * ifp->if_addrlen;
                break;
        }
        m->m_pkthdr.len = m->m_len;
        m_align(m, m->m_len);
        ah = mtod(m, struct arphdr *);
        memset(ah, 0, m->m_len);
        switch (ifp->if_type) {
        case IFT_IEEE1394:      /* RFC2734 */
                /* fill it now for ar_tpa computation */
                ah->ar_hrd = htons(ARPHRD_IEEE1394);
                break;
        default:
                /* ifp->if_output will fill ar_hrd */
                break;
        }
        ah->ar_pro = htons(ETHERTYPE_IP);
        ah->ar_hln = ifp->if_addrlen;           /* hardware address length */
        ah->ar_pln = sizeof(struct in_addr);    /* protocol address length */
        ah->ar_op = htons(ARPOP_REQUEST);
        memcpy(ar_sha(ah), saddr, ah->ar_hln);
        if (taddr == NULL)
                m->m_flags |= M_BCAST;
        else
                memcpy(ar_tha(ah), taddr, ah->ar_hln);
        memcpy(ar_spa(ah), sip, ah->ar_pln);
        memcpy(ar_tpa(ah), tip, ah->ar_pln);
        sa.sa_family = AF_ARP;
        sa.sa_len = 2;
        arps = ARP_STAT_GETREF();
        _NET_STATINC_REF(arps, ARP_STAT_SNDTOTAL);
        _NET_STATINC_REF(arps, ARP_STAT_SENDREQUEST);
        ARP_STAT_PUTREF();
        if_output_lock(ifp, ifp, m, &sa, NULL);
}

void
arpannounce(struct ifnet *ifp, struct ifaddr *ifa, const uint8_t *enaddr)
{
        struct in_ifaddr *ia = ifatoia(ifa);
        struct in_addr *ip = &IA_SIN(ifa)->sin_addr;

        if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED)) {
                ARPLOG(LOG_DEBUG, "%s not ready\n", ARPLOGADDR(ip));
                return;
        }
        arprequest(ifp, ip, ip, enaddr, NULL);
}

static void
arpannounce1(struct ifaddr *ifa)
{

        arpannounce(ifa->ifa_ifp, ifa, CLLADDR(ifa->ifa_ifp->if_sadl));
}

/*
 * Resolve an IP address into an ethernet address.  If success, desten is
 * filled in. If there is no entry in arptab, set one up and broadcast a
 * request for the IP address. Hold onto this mbuf and resend it once the
 * address is finally resolved.
 *
 * A return value of 0 indicates that desten has been filled in and the packet
 * should be sent normally; a return value of EWOULDBLOCK indicates that the
 * packet has been held pending resolution. Any other value indicates an
 * error.
 */
int
arpresolve(struct ifnet *ifp, const struct rtentry *rt, struct mbuf *m,
    const struct sockaddr *dst, void *desten, size_t destlen)
{
        struct llentry *la;
        const char *create_lookup;
        int error;

#if NCARP > 0
        if (rt != NULL && rt->rt_ifp->if_type == IFT_CARP)
                ifp = rt->rt_ifp;
#endif

        KASSERT(m != NULL);

        la = arplookup(ifp, NULL, dst, 0);
        if (la == NULL)
                goto notfound;

        if (la->la_flags & LLE_VALID && la->ln_state == ND_LLINFO_REACHABLE) {
                KASSERT(destlen >= ifp->if_addrlen);
                memcpy(desten, &la->ll_addr, ifp->if_addrlen);
                LLE_RUNLOCK(la);
                return 0;
        }

notfound:
        if (ifp->if_flags & IFF_NOARP) {
                if (la != NULL)
                        LLE_RUNLOCK(la);
                error = ENOTSUP;
                goto bad;
        }

        if (la == NULL) {
                struct rtentry *_rt;

                create_lookup = "create";
                _rt = rtalloc1(dst, 0);
                IF_AFDATA_WLOCK(ifp);
                la = lla_create(LLTABLE(ifp), LLE_EXCLUSIVE, dst, _rt);
                IF_AFDATA_WUNLOCK(ifp);
                if (_rt != NULL)
                        rt_unref(_rt);
                if (la == NULL)
                        ARP_STATINC(ARP_STAT_ALLOCFAIL);
                else
                        la->ln_state = ND_LLINFO_NOSTATE;
        } else if (LLE_TRY_UPGRADE(la) == 0) {
                create_lookup = "lookup";
                LLE_RUNLOCK(la);
                IF_AFDATA_RLOCK(ifp);
                la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst);
                IF_AFDATA_RUNLOCK(ifp);
        }

        error = EINVAL;
        if (la == NULL) {
                log(LOG_DEBUG,
                    "%s: failed to %s llentry for %s on %s\n",
                    __func__, create_lookup, inet_ntoa(satocsin(dst)->sin_addr),
                    ifp->if_xname);
                goto bad;
        }

        error = nd_resolve(la, rt, m, desten, destlen);
        return error;

bad:
        m_freem(m);
        return error;
}

/*
 * Common length and type checks are done here,
 * then the protocol-specific routine is called.
 */
void
arpintr(void *arg __unused)
{
        struct mbuf *m;
        struct arphdr *ar;
        int s;
        int arplen;
        struct ifnet *rcvif;
        bool badhrd;

        SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE();
        while ((m = pktq_dequeue(arp_pktq)) != NULL) {
                if ((m->m_flags & M_PKTHDR) == 0)
                        panic("arpintr");

                MCLAIM(m, &arpdomain.dom_mowner);
                ARP_STATINC(ARP_STAT_RCVTOTAL);

                if (__predict_false(m->m_len < sizeof(*ar))) {
                        if ((m = m_pullup(m, sizeof(*ar))) == NULL)
                                goto badlen;
                }
                ar = mtod(m, struct arphdr *);
                KASSERT(ACCESSIBLE_POINTER(ar, struct arphdr));

                rcvif = m_get_rcvif(m, &s);
                if (__predict_false(rcvif == NULL)) {
                        ARP_STATINC(ARP_STAT_RCVNOINT);
                        goto free;
                }

                /*
                 * We don't want non-IEEE1394 ARP packets on IEEE1394
                 * interfaces, and vice versa. Our life depends on that.
                 */
                if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394)
                        badhrd = rcvif->if_type != IFT_IEEE1394;
                else
                        badhrd = rcvif->if_type == IFT_IEEE1394;

                m_put_rcvif(rcvif, &s);

                if (badhrd) {
                        ARP_STATINC(ARP_STAT_RCVBADPROTO);
                        goto free;
                }

                arplen = sizeof(*ar) + 2 * ar->ar_hln + 2 * ar->ar_pln;
                if (__predict_false(m->m_len < arplen)) {
                        if ((m = m_pullup(m, arplen)) == NULL)
                                goto badlen;
                        ar = mtod(m, struct arphdr *);
                        KASSERT(ACCESSIBLE_POINTER(ar, struct arphdr));
                }

                switch (ntohs(ar->ar_pro)) {
                case ETHERTYPE_IP:
                case ETHERTYPE_IPTRAILERS:
                        in_arpinput(m);
                        continue;
                default:
                        ARP_STATINC(ARP_STAT_RCVBADPROTO);
                        goto free;
                }

badlen:
                ARP_STATINC(ARP_STAT_RCVBADLEN);
free:
                m_freem(m);
        }
        SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE();
        return; /* XXX gcc */
}

/*
 * ARP for Internet protocols on 10 Mb/s Ethernet. Algorithm is that given in
 * RFC 826. In addition, a sanity check is performed on the sender protocol
 * address, to catch impersonators.
 *
 * We no longer handle negotiations for use of trailer protocol: formerly, ARP
 * replied for protocol type ETHERTYPE_TRAIL sent along with IP replies if we
 * wanted trailers sent to us, and also sent them in response to IP replies.
 * This allowed either end to announce the desire to receive trailer packets.
 *
 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, but
 * formerly didn't normally send requests.
 */
static void
in_arpinput(struct mbuf *m)
{
        struct arphdr *ah;
        struct ifnet *ifp, *rcvif = NULL;
        struct llentry *la = NULL;
        struct in_ifaddr *ia = NULL;
#if NBRIDGE > 0
        struct in_ifaddr *bridge_ia = NULL;
#endif
#if NCARP > 0
        uint32_t count = 0, index = 0;
#endif
        struct sockaddr sa;
        struct in_addr isaddr, itaddr, myaddr;
        int op, rt_cmd, new_state = 0;
        void *tha;
        net_stat_ref_t arps;
        struct psref psref, psref_ia;
        int s;
        char ipbuf[INET_ADDRSTRLEN];
        bool find_source, do_dad;

        if (__predict_false(m_makewritable(&m, 0, m->m_pkthdr.len, M_DONTWAIT)))
                goto out;
        ah = mtod(m, struct arphdr *);
        op = ntohs(ah->ar_op);

        if (ah->ar_pln != sizeof(struct in_addr))
                goto out;

        /* RFC5227 2.4 says any of the host's own interface addresses
         * are not conflicting ARP packets. */
        ifp = if_get_bylla(ar_sha(ah), ah->ar_hln, &psref);
        if (ifp) {
                /* it's from me, ignore it. */
                if_put(ifp, &psref);
                ARP_STATINC(ARP_STAT_RCVLOCALSHA);
                goto out;
        }

        rcvif = ifp = m_get_rcvif_psref(m, &psref);
        if (__predict_false(rcvif == NULL))
                goto out;
        if (rcvif->if_flags & IFF_NOARP)
                goto out;

        memcpy(&isaddr, ar_spa(ah), sizeof(isaddr));
        memcpy(&itaddr, ar_tpa(ah), sizeof(itaddr));

        if (m->m_flags & (M_BCAST|M_MCAST))
                ARP_STATINC(ARP_STAT_RCVMCAST);

        /*
         * Search for a matching interface address
         * or any address on the interface to use
         * as a dummy address in the rest of this function.
         *
         * First try and find the source address for early
         * duplicate address detection.
         */
        if (in_nullhost(isaddr)) {
                if (in_nullhost(itaddr)) /* very bogus ARP */
                        goto out;
                find_source = false;
                myaddr = itaddr;
        } else {
                find_source = true;
                myaddr = isaddr;
        }
        s = pserialize_read_enter();
again:
        IN_ADDRHASH_READER_FOREACH(ia, myaddr.s_addr) {
                if (!in_hosteq(ia->ia_addr.sin_addr, myaddr))
                        continue;
#if NCARP > 0
                if (ia->ia_ifp->if_type == IFT_CARP &&
                    ((ia->ia_ifp->if_flags & (IFF_UP|IFF_RUNNING)) ==
                    (IFF_UP|IFF_RUNNING))) {
                        index++;
                        /* XXX: ar_hln? */
                        if (ia->ia_ifp == rcvif && (ah->ar_hln >= 6) &&
                            carp_iamatch(ia, ar_sha(ah),
                            &count, index)) {
                                break;
                        }
                } else
#endif
                if (ia->ia_ifp == rcvif)
                        break;
#if NBRIDGE > 0
                /*
                 * If the interface we received the packet on
                 * is part of a bridge, check to see if we need
                 * to "bridge" the packet to ourselves at this
                 * layer.  Note we still prefer a perfect match,
                 * but allow this weaker match if necessary.
                 */
                if (rcvif->if_bridge != NULL &&
                    rcvif->if_bridge == ia->ia_ifp->if_bridge)
                        bridge_ia = ia;
#endif
        }

#if NBRIDGE > 0
        if (ia == NULL && bridge_ia != NULL) {
                ia = bridge_ia;
                m_put_rcvif_psref(rcvif, &psref);
                rcvif = NULL;
                /* FIXME */
                ifp = bridge_ia->ia_ifp;
        }
#endif

        /* If we failed to find the source address then find
         * the target address. */
        if (ia == NULL && find_source && !in_nullhost(itaddr)) {
                find_source = false;
                myaddr = itaddr;
                goto again;
        }

        if (ia != NULL)
                ia4_acquire(ia, &psref_ia);
        pserialize_read_exit(s);

        if (ah->ar_hln != ifp->if_addrlen) {
                ARP_STATINC(ARP_STAT_RCVBADLEN);
                log(LOG_WARNING,
                    "arp from %s: addr len: new %d, i/f %d (ignored)\n",
                    IN_PRINT(ipbuf, &isaddr), ah->ar_hln, ifp->if_addrlen);
                goto out;
        }

        /* Only do DaD if we have a matching address. */
        do_dad = (ia != NULL);

        if (ia == NULL) {
                ia = in_get_ia_on_iface_psref(isaddr, rcvif, &psref_ia);
                if (ia == NULL) {
                        ia = in_get_ia_from_ifp_psref(ifp, &psref_ia);
                        if (ia == NULL) {
                                ARP_STATINC(ARP_STAT_RCVNOINT);
                                goto out;
                        }
                }
        }

        myaddr = ia->ia_addr.sin_addr;

        /* XXX checks for bridge case? */
        if (!memcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) {
                ARP_STATINC(ARP_STAT_RCVBCASTSHA);
                log(LOG_ERR,
                    "%s: arp: link address is broadcast for IP address %s!\n",
                    ifp->if_xname, IN_PRINT(ipbuf, &isaddr));
                goto out;
        }

        /*
         * If the source IP address is zero, this is an RFC 5227 ARP probe
         */
        if (in_nullhost(isaddr))
                ARP_STATINC(ARP_STAT_RCVZEROSPA);
        else if (in_hosteq(isaddr, myaddr)) {
                ARP_STATINC(ARP_STAT_RCVLOCALSPA);
                /* This is the original behavior prior to supporting IPv4 DAD */
                if (!ip_dad_enabled()) {
                        char llabuf[LLA_ADDRSTRLEN];
                        log(LOG_ERR,
                            "duplicate IP address %s sent from link address %s\n",
                            IN_PRINT(ipbuf, &isaddr),
                            lla_snprintf(llabuf, sizeof(llabuf), ar_sha(ah),
                                         ah->ar_hln));
                        itaddr = myaddr;
                        goto reply;
                }
        }

        if (in_nullhost(itaddr))
                ARP_STATINC(ARP_STAT_RCVZEROTPA);

        /*
         * DAD check, RFC 5227.
         * ARP sender hardware address must match the interface
         * address of the interface sending the packet.
         * Collision on sender address is always a duplicate.
         * Collision on target address is only a duplicate
         * IF the sender address is the null host (ie a DAD probe)
         * AND the message was broadcast
         * AND our address is either tentative or duplicated
         * If it was unicast then it's a valid Unicast Poll from RFC 1122.
         */
        if (ip_dad_enabled() && do_dad &&
            (in_hosteq(isaddr, myaddr) ||
            (in_nullhost(isaddr) && in_hosteq(itaddr, myaddr) &&
             m->m_flags & M_BCAST &&
             ia->ia4_flags & (IN_IFF_TENTATIVE | IN_IFF_DUPLICATED))))
        {
                struct m_tag *mtag;

                mtag = m_tag_find(m, PACKET_TAG_ETHERNET_SRC);
                if (mtag == NULL || (ah->ar_hln == ETHER_ADDR_LEN &&
                    memcmp(mtag + 1, ar_sha(ah), ah->ar_hln) == 0)) {
                        struct sockaddr_dl sdl, *sdlp;

                        sdlp = sockaddr_dl_init(&sdl, sizeof(sdl),
                            ifp->if_index, ifp->if_type,
                            NULL, 0, ar_sha(ah), ah->ar_hln);
                        arp_dad_duplicated((struct ifaddr *)ia, sdlp);
                        goto out;
                }
        }

        /*
         * If the target IP address is zero, ignore the packet.
         * This prevents the code below from trying to answer
         * when we are using IP address zero (booting).
         */
        if (in_nullhost(itaddr))
                goto out;

        if (in_nullhost(isaddr))
                goto reply;

        if (in_hosteq(itaddr, myaddr))
                la = arpcreate(ifp, &isaddr, NULL, 1);
        else
                la = arplookup(ifp, &isaddr, NULL, 1);
        if (la == NULL)
                goto reply;

        if ((la->la_flags & LLE_VALID) &&
            memcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen))
        {
                char llabuf[LLA_ADDRSTRLEN], *llastr;

                llastr = lla_snprintf(llabuf, sizeof(llabuf),
                    ar_sha(ah), ah->ar_hln);

                if (la->la_flags & LLE_STATIC) {
                        ARP_STATINC(ARP_STAT_RCVOVERPERM);
                        if (!log_permanent_modify)
                                goto out;
                        log(LOG_INFO,
                            "%s tried to overwrite permanent arp info"
                            " for %s\n", llastr, IN_PRINT(ipbuf, &isaddr));
                        goto out;
                } else if (la->lle_tbl->llt_ifp != ifp) {
                        /* XXX should not happen? */
                        ARP_STATINC(ARP_STAT_RCVOVERINT);
                        if (!log_wrong_iface)
                                goto out;
                        log(LOG_INFO,
                            "%s on %s tried to overwrite "
                            "arp info for %s on %s\n",
                            llastr,
                            ifp->if_xname, IN_PRINT(ipbuf, &isaddr),
                            la->lle_tbl->llt_ifp->if_xname);
                                goto out;
                } else {
                        ARP_STATINC(ARP_STAT_RCVOVER);
                        if (log_movements)
                                log(LOG_INFO, "arp info overwritten "
                                    "for %s by %s\n",
                                    IN_PRINT(ipbuf, &isaddr), llastr);
                }
                rt_cmd = RTM_CHANGE;
                new_state = ND_LLINFO_STALE;
        } else {
                if (op == ARPOP_REPLY && in_hosteq(itaddr, myaddr)) {
                        /* This was a solicited ARP reply. */
                        la->ln_byhint = 0;
                        new_state = ND_LLINFO_REACHABLE;
                } else if (op == ARPOP_REQUEST &&
                           (la->ln_state == ND_LLINFO_NOSTATE ||
                            la->ln_state == ND_LLINFO_INCOMPLETE)) {
                        /*
                         * If an ARP request comes but there is no entry
                         * and a new one has been created or an entry exists
                         * but incomplete, make it stale to allow to send
                         * packets to the requester without an ARP resolution.
                         */
                        la->ln_byhint = 0;
                        new_state = ND_LLINFO_STALE;
                }
                rt_cmd = la->la_flags & LLE_VALID ? 0 : RTM_ADD;
        }

        KASSERT(ifp->if_sadl->sdl_alen == ifp->if_addrlen);

        KASSERT(sizeof(la->ll_addr) >= ifp->if_addrlen);
        memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen);
        la->la_flags |= LLE_VALID;
        la->la_flags &= ~LLE_UNRESOLVED;
        la->ln_asked = 0;
        if (new_state != 0) {
                la->ln_state = new_state;

                if (new_state != ND_LLINFO_REACHABLE ||
                    !(la->la_flags & LLE_STATIC))
                {
                        int timer = ND_TIMER_GC;

                        if (new_state == ND_LLINFO_REACHABLE)
                                timer = ND_TIMER_REACHABLE;
                        nd_set_timer(la, timer);
                }
        }

        if (rt_cmd != 0) {
                struct sockaddr_in sin;

                sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0);
                rt_clonedmsg(rt_cmd, NULL, sintosa(&sin), ar_sha(ah), ifp);
        }

        if (la->la_hold != NULL) {
                int n = la->la_numheld;
                struct mbuf *m_hold, *m_hold_next;
                struct sockaddr_in sin;

                sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0);

                m_hold = la->la_hold;
                la->la_hold = NULL;
                la->la_numheld = 0;
                /*
                 * We have to unlock here because if_output would call
                 * arpresolve
                 */
                LLE_WUNLOCK(la);
                ARP_STATADD(ARP_STAT_DFRSENT, n);
                ARP_STATADD(ARP_STAT_DFRTOTAL, n);
                for (; m_hold != NULL; m_hold = m_hold_next) {
                        m_hold_next = m_hold->m_nextpkt;
                        m_hold->m_nextpkt = NULL;
                        if_output_lock(ifp, ifp, m_hold, sintosa(&sin), NULL);
                }
        } else
                LLE_WUNLOCK(la);
        la = NULL;

reply:
        if (la != NULL) {
                LLE_WUNLOCK(la);
                la = NULL;
        }
        if (op != ARPOP_REQUEST) {
                if (op == ARPOP_REPLY)
                        ARP_STATINC(ARP_STAT_RCVREPLY);
                goto out;
        }
        ARP_STATINC(ARP_STAT_RCVREQUEST);
        if (in_hosteq(itaddr, myaddr)) {
                /* If our address is unusable, don't reply */
                if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED))
                        goto out;
                /* I am the target */
                tha = ar_tha(ah);
                if (tha)
                        memcpy(tha, ar_sha(ah), ah->ar_hln);
                memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln);
        } else {
                /* Proxy ARP */
                struct llentry *lle = NULL;
                struct sockaddr_in sin;

#if NCARP > 0
                if (ifp->if_type == IFT_CARP) {
                        struct ifnet *_rcvif = m_get_rcvif(m, &s);
                        int iftype = 0;
                        if (__predict_true(_rcvif != NULL))
                                iftype = _rcvif->if_type;
                        m_put_rcvif(_rcvif, &s);
                        if (iftype != IFT_CARP)
                                goto out;
                }
#endif

                tha = ar_tha(ah);

                sockaddr_in_init(&sin, &itaddr, 0);

                IF_AFDATA_RLOCK(ifp);
                lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin);
                IF_AFDATA_RUNLOCK(ifp);

                if ((lle != NULL) && (lle->la_flags & LLE_PUB)) {
                        if (tha)
                                memcpy(tha, ar_sha(ah), ah->ar_hln);
                        memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln);
                        LLE_RUNLOCK(lle);
                } else {
                        if (lle != NULL)
                                LLE_RUNLOCK(lle);
                        goto out;
                }
        }
        ia4_release(ia, &psref_ia);

        /*
         * XXX XXX: Here we're recycling the mbuf. But the mbuf could have
         * other mbufs in its chain, and just overwriting m->m_pkthdr.len
         * would be wrong in this case (the length becomes smaller than the
         * real chain size).
         *
         * This can theoretically cause bugs in the lower layers (drivers,
         * and L2encap), in some corner cases.
         */
        memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln);
        memcpy(ar_spa(ah), &itaddr, ah->ar_pln);
        ah->ar_op = htons(ARPOP_REPLY);
        ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */
        switch (ifp->if_type) {
        case IFT_IEEE1394:
                /* ieee1394 arp reply is broadcast */
                m->m_flags &= ~M_MCAST;
                m->m_flags |= M_BCAST;
                m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + ah->ar_hln;
                break;
        default:
                m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */
                m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln);
                break;
        }
        m->m_pkthdr.len = m->m_len;
        m->m_pkthdr.csum_flags = 0; /* Clear any in-bound checksum flags. */
        sa.sa_family = AF_ARP;
        sa.sa_len = 2;
        arps = ARP_STAT_GETREF();
        _NET_STATINC_REF(arps, ARP_STAT_SNDTOTAL);
        _NET_STATINC_REF(arps, ARP_STAT_SNDREPLY);
        ARP_STAT_PUTREF();
        if_output_lock(ifp, ifp, m, &sa, NULL);
        if (rcvif != NULL)
                m_put_rcvif_psref(rcvif, &psref);
        return;

out:
        if (la != NULL)
                LLE_WUNLOCK(la);
        if (ia != NULL)
                ia4_release(ia, &psref_ia);
        if (rcvif != NULL)
                m_put_rcvif_psref(rcvif, &psref);
        m_freem(m);
}

/*
 * Lookup or a new address in arptab.
 */
struct llentry *
arplookup(struct ifnet *ifp, const struct in_addr *addr,
    const struct sockaddr *sa, int wlock)
{
        struct sockaddr_in sin;
        struct llentry *la;
        int flags = wlock ? LLE_EXCLUSIVE : 0;

        if (sa == NULL) {
                KASSERT(addr != NULL);
                sockaddr_in_init(&sin, addr, 0);
                sa = sintocsa(&sin);
        }

        IF_AFDATA_RLOCK(ifp);
        la = lla_lookup(LLTABLE(ifp), flags, sa);
        IF_AFDATA_RUNLOCK(ifp);

        return la;
}

static struct llentry *
arpcreate(struct ifnet *ifp, const struct in_addr *addr,
    const struct sockaddr *sa, int wlock)
{
        struct sockaddr_in sin;
        struct llentry *la;
        int flags = wlock ? LLE_EXCLUSIVE : 0;

        if (sa == NULL) {
                KASSERT(addr != NULL);
                sockaddr_in_init(&sin, addr, 0);
                sa = sintocsa(&sin);
        }

        la = arplookup(ifp, addr, sa, wlock);

        if (la == NULL) {
                struct rtentry *rt;

                rt = rtalloc1(sa, 0);
                IF_AFDATA_WLOCK(ifp);
                la = lla_create(LLTABLE(ifp), flags, sa, rt);
                IF_AFDATA_WUNLOCK(ifp);
                if (rt != NULL)
                        rt_unref(rt);

                if (la != NULL)
                        la->ln_state = ND_LLINFO_NOSTATE;
        }

        return la;
}

int
arpioctl(u_long cmd, void *data)
{

        return EOPNOTSUPP;
}

void
arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa)
{
        struct in_ifaddr *ia = (struct in_ifaddr *)ifa;

        ifa->ifa_rtrequest = arp_rtrequest;
        ifa->ifa_flags |= RTF_CONNECTED;

        /* ARP will handle DAD for this address. */
        if (in_nullhost(IA_SIN(ifa)->sin_addr)) {
                if (ia->ia_dad_stop != NULL)    /* safety */
                        ia->ia_dad_stop(ifa);
                ia->ia_dad_start = NULL;
                ia->ia_dad_stop = NULL;
                ia->ia4_flags &= ~IN_IFF_TENTATIVE;
        } else {
                ia->ia_dad_start = arp_dad_start;
                ia->ia_dad_stop = arp_dad_stop;
                if (ia->ia4_flags & IN_IFF_TRYTENTATIVE && ip_dad_enabled())
                        ia->ia4_flags |= IN_IFF_TENTATIVE;
                else
                        arpannounce1(ifa);
        }
}

static bool
arp_nud_enabled(__unused struct ifnet *ifp)
{

        return arp_perform_nud != 0;
}

static unsigned int
arp_llinfo_reachable(__unused struct ifnet *ifp)
{

        return arp_reachable;
}

static unsigned int
arp_llinfo_retrans(__unused struct ifnet *ifp)
{

        return arp_retrans;
}

/*
 * Gets source address of the first packet in hold queue
 * and stores it in @src.
 * Returns pointer to @src (if hold queue is not empty) or NULL.
 */
static union l3addr *
arp_llinfo_holdsrc(struct llentry *ln, union l3addr *src)
{
        struct ip *ip;

        if (ln == NULL || ln->ln_hold == NULL)
                return NULL;

        /*
         * assuming every packet in ln_hold has the same IP header
         */
        ip = mtod(ln->ln_hold, struct ip *);
        /* XXX pullup? */
        if (sizeof(*ip) < ln->ln_hold->m_len)
                src->addr4 = ip->ip_src;
        else
                src = NULL;

        return src;
}

static void
arp_llinfo_output(struct ifnet *ifp, __unused const union l3addr *daddr,
    const union l3addr *taddr, const uint8_t *tlladdr,
    const union l3addr *hsrc)
{
        struct in_addr tip = taddr->addr4, sip = zeroin_addr;
        const uint8_t *slladdr = CLLADDR(ifp->if_sadl);

        if (hsrc != NULL) {
                struct in_ifaddr *ia;
                struct psref psref;

                ia = in_get_ia_on_iface_psref(hsrc->addr4, ifp, &psref);
                if (ia != NULL) {
                        sip = hsrc->addr4;
                        ia4_release(ia, &psref);
                }
        }

        if (sip.s_addr == INADDR_ANY) {
                struct sockaddr_in dst;
                struct rtentry *rt;

                sockaddr_in_init(&dst, &tip, 0);
                rt = rtalloc1(sintosa(&dst), 0);
                if (rt != NULL) {
                        if (rt->rt_ifp == ifp &&
                            rt->rt_ifa != NULL &&
                            rt->rt_ifa->ifa_addr->sa_family == AF_INET)
                                sip = satosin(rt->rt_ifa->ifa_addr)->sin_addr;
                        rt_unref(rt);
                }
                if (sip.s_addr == INADDR_ANY) {
                        char ipbuf[INET_ADDRSTRLEN];

                        log(LOG_DEBUG, "%s: source can't be "
                            "determined: dst=%s\n", __func__,
                            IN_PRINT(ipbuf, &tip));
                        return;
                }
        }

        arprequest(ifp, &sip, &tip, slladdr, tlladdr);
}


static void
arp_llinfo_missed(struct ifnet *ifp, const union l3addr *taddr,
    __unused int16_t type, struct mbuf *m)
{
        struct in_addr mdaddr = zeroin_addr;
        struct sockaddr_in dsin, tsin;
        struct sockaddr *sa;

        if (m != NULL) {
                struct ip *ip = mtod(m, struct ip *);

                if (sizeof(*ip) < m->m_len)
                        mdaddr = ip->ip_src;

                /* ip_input() will send ICMP_UNREACH_HOST, not us. */
                m_freem(m);
        }

        if (mdaddr.s_addr != INADDR_ANY) {
                sockaddr_in_init(&dsin, &mdaddr, 0);
                sa = sintosa(&dsin);
        } else
                sa = NULL;

        sockaddr_in_init(&tsin, &taddr->addr4, 0);
        rt_clonedmsg(RTM_MISS, sa, sintosa(&tsin), NULL, ifp);
}

static void
arp_free(struct llentry *ln, int gc)
{
        struct ifnet *ifp;

        KASSERT(ln != NULL);
        LLE_WLOCK_ASSERT(ln);

        ifp = ln->lle_tbl->llt_ifp;

        if (ln->la_flags & LLE_VALID || gc) {
                struct sockaddr_in sin;
                const char *lladdr;

                sockaddr_in_init(&sin, &ln->r_l3addr.addr4, 0);
                lladdr = ln->la_flags & LLE_VALID ?
                    (const char *)&ln->ll_addr : NULL;
                rt_clonedmsg(RTM_DELETE, NULL, sintosa(&sin), lladdr, ifp);
        }

        /*
         * Save to unlock. We still hold an extra reference and will not
         * free(9) in llentry_free() if someone else holds one as well.
         */
        LLE_WUNLOCK(ln);
        IF_AFDATA_LOCK(ifp);
        LLE_WLOCK(ln);

        lltable_free_entry(LLTABLE(ifp), ln);

        IF_AFDATA_UNLOCK(ifp);
}

/*
 * Upper-layer reachability hint for Neighbor Unreachability Detection.
 *
 * XXX cost-effective methods?
 */
void
arp_nud_hint(struct rtentry *rt)
{
        struct llentry *ln;
        struct ifnet *ifp;

        if (rt == NULL)
                return;

        ifp = rt->rt_ifp;
        ln = arplookup(ifp, NULL, rt_getkey(rt), 1);
        nd_nud_hint(ln);
}

TAILQ_HEAD(dadq_head, dadq);
struct dadq {
        TAILQ_ENTRY(dadq) dad_list;
        struct ifaddr *dad_ifa;
        int dad_count;          /* max ARP to send */
        int dad_arp_tcount;     /* # of trials to send ARP */
        int dad_arp_ocount;     /* ARP sent so far */
        int dad_arp_announce;   /* max ARP announcements */
        int dad_arp_acount;     /* # of announcements */
        struct callout dad_timer_ch;
};

static struct dadq_head dadq;
static int dad_maxtry = 15;     /* max # of *tries* to transmit DAD packet */
static kmutex_t arp_dad_lock;

static void
arp_dad_init(void)
{

        TAILQ_INIT(&dadq);
        mutex_init(&arp_dad_lock, MUTEX_DEFAULT, IPL_NONE);
}

static struct dadq *
arp_dad_find(struct ifaddr *ifa)
{
        struct dadq *dp;

        KASSERT(mutex_owned(&arp_dad_lock));

        TAILQ_FOREACH(dp, &dadq, dad_list) {
                if (dp->dad_ifa == ifa)
                        return dp;
        }
        return NULL;
}

static void
arp_dad_starttimer(struct dadq *dp, int ticks)
{

        callout_reset(&dp->dad_timer_ch, ticks,
            (void (*)(void *))arp_dad_timer, dp);
}

static void
arp_dad_stoptimer(struct dadq *dp)
{

        KASSERT(mutex_owned(&arp_dad_lock));

        TAILQ_REMOVE(&dadq, dp, dad_list);
        /* Tell the timer that dp is being destroyed. */
        dp->dad_ifa = NULL;
        callout_halt(&dp->dad_timer_ch, &arp_dad_lock);
}

static void
arp_dad_destroytimer(struct dadq *dp)
{

        callout_destroy(&dp->dad_timer_ch);
        KASSERT(dp->dad_ifa == NULL);
        kmem_intr_free(dp, sizeof(*dp));
}

static void
arp_dad_output(struct dadq *dp, struct ifaddr *ifa)
{
        struct in_ifaddr *ia = (struct in_ifaddr *)ifa;
        struct ifnet *ifp = ifa->ifa_ifp;
        struct in_addr sip;

        dp->dad_arp_tcount++;
        if ((ifp->if_flags & IFF_UP) == 0)
                return;
        if ((ifp->if_flags & IFF_RUNNING) == 0)
                return;

        dp->dad_arp_tcount = 0;
        dp->dad_arp_ocount++;

        memset(&sip, 0, sizeof(sip));
        arprequest(ifa->ifa_ifp, &sip, &ia->ia_addr.sin_addr,
            CLLADDR(ifa->ifa_ifp->if_sadl), NULL);
}

/*
 * Start Duplicate Address Detection (DAD) for specified interface address.
 */
static void
arp_dad_start(struct ifaddr *ifa)
{
        struct in_ifaddr *ia = (struct in_ifaddr *)ifa;
        struct dadq *dp;
        char ipbuf[INET_ADDRSTRLEN];

        /*
         * If we don't need DAD, don't do it.
         * - DAD is disabled
         */
        if (!(ia->ia4_flags & IN_IFF_TENTATIVE)) {
                log(LOG_DEBUG,
                    "%s: called with non-tentative address %s(%s)\n", __func__,
                    IN_PRINT(ipbuf, &ia->ia_addr.sin_addr),
                    ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
                return;
        }
        if (!ip_dad_enabled()) {
                ia->ia4_flags &= ~IN_IFF_TENTATIVE;
                rt_addrmsg(RTM_NEWADDR, ifa);
                arpannounce1(ifa);
                return;
        }
        KASSERT(ifa->ifa_ifp != NULL);
        if (!(ifa->ifa_ifp->if_flags & IFF_UP))
                return;

        dp = kmem_intr_alloc(sizeof(*dp), KM_NOSLEEP);

        mutex_enter(&arp_dad_lock);
        if (arp_dad_find(ifa) != NULL) {
                mutex_exit(&arp_dad_lock);
                /* DAD already in progress */
                if (dp != NULL)
                        kmem_intr_free(dp, sizeof(*dp));
                return;
        }

        if (dp == NULL) {
                mutex_exit(&arp_dad_lock);
                log(LOG_ERR, "%s: memory allocation failed for %s(%s)\n",
                    __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr),
                    ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
                return;
        }

        /*
         * Send ARP packet for DAD, ip_dad_count times.
         * Note that we must delay the first transmission.
         */
        callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE);
        dp->dad_ifa = ifa;
        ifaref(ifa);    /* just for safety */
        dp->dad_count = ip_dad_count;
        dp->dad_arp_announce = 0; /* Will be set when starting to announce */
        dp->dad_arp_acount = dp->dad_arp_ocount = dp->dad_arp_tcount = 0;
        TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list);

        ARPLOG(LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
            ARPLOGADDR(&ia->ia_addr.sin_addr));

        arp_dad_starttimer(dp, cprng_fast32() % (PROBE_WAIT * hz));

        mutex_exit(&arp_dad_lock);
}

/*
 * terminate DAD unconditionally.  used for address removals.
 */
static void
arp_dad_stop(struct ifaddr *ifa)
{
        struct dadq *dp;

        mutex_enter(&arp_dad_lock);
        dp = arp_dad_find(ifa);
        if (dp == NULL) {
                mutex_exit(&arp_dad_lock);
                /* DAD wasn't started yet */
                return;
        }

        arp_dad_stoptimer(dp);

        mutex_exit(&arp_dad_lock);

        arp_dad_destroytimer(dp);
        ifafree(ifa);
}

static void
arp_dad_timer(struct dadq *dp)
{
        struct ifaddr *ifa;
        struct in_ifaddr *ia;
        char ipbuf[INET_ADDRSTRLEN];
        bool need_free = false;

        KERNEL_LOCK_UNLESS_NET_MPSAFE();
        mutex_enter(&arp_dad_lock);

        ifa = dp->dad_ifa;
        if (ifa == NULL) {
                /* dp is being destroyed by someone.  Do nothing. */
                goto done;
        }

        ia = (struct in_ifaddr *)ifa;
        if (ia->ia4_flags & IN_IFF_DUPLICATED) {
                log(LOG_ERR, "%s: called with duplicate address %s(%s)\n",
                    __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr),
                    ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
                goto done;
        }
        if ((ia->ia4_flags & IN_IFF_TENTATIVE) == 0 && dp->dad_arp_acount == 0)
        {
                log(LOG_ERR, "%s: called with non-tentative address %s(%s)\n",
                    __func__, IN_PRINT(ipbuf, &ia->ia_addr.sin_addr),
                    ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
                goto done;
        }

        /* timeouted with IFF_{RUNNING,UP} check */
        if (dp->dad_arp_tcount > dad_maxtry) {
                ARPLOG(LOG_INFO, "%s: could not run DAD, driver problem?\n",
                    if_name(ifa->ifa_ifp));

                arp_dad_stoptimer(dp);
                need_free = true;
                goto done;
        }

        /* Need more checks? */
        if (dp->dad_arp_ocount < dp->dad_count) {
                int adelay;

                /*
                 * We have more ARP to go.  Send ARP packet for DAD.
                 */
                arp_dad_output(dp, ifa);
                if (dp->dad_arp_ocount < dp->dad_count)
                        adelay = (PROBE_MIN * hz) +
                            (cprng_fast32() %
                            ((PROBE_MAX * hz) - (PROBE_MIN * hz)));
                else
                        adelay = ANNOUNCE_WAIT * hz;
                arp_dad_starttimer(dp, adelay);
                goto done;
        } else if (dp->dad_arp_acount == 0) {
                /*
                 * We are done with DAD.
                 * No duplicate address found.
                 */
                ia->ia4_flags &= ~IN_IFF_TENTATIVE;
                rt_addrmsg(RTM_NEWADDR, ifa);
                ARPLOG(LOG_DEBUG,
                    "%s: DAD complete for %s - no duplicates found\n",
                    if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr));
                dp->dad_arp_announce = ANNOUNCE_NUM;
                goto announce;
        } else if (dp->dad_arp_acount < dp->dad_arp_announce) {
announce:
                /*
                 * Announce the address.
                 */
                arpannounce1(ifa);
                dp->dad_arp_acount++;
                if (dp->dad_arp_acount < dp->dad_arp_announce) {
                        arp_dad_starttimer(dp, ANNOUNCE_INTERVAL * hz);
                        goto done;
                }
                ARPLOG(LOG_DEBUG,
                    "%s: ARP announcement complete for %s\n",
                    if_name(ifa->ifa_ifp), ARPLOGADDR(&ia->ia_addr.sin_addr));
        }

        arp_dad_stoptimer(dp);
        need_free = true;
done:
        mutex_exit(&arp_dad_lock);

        if (need_free) {
                arp_dad_destroytimer(dp);
                KASSERT(ifa != NULL);
                ifafree(ifa);
        }

        KERNEL_UNLOCK_UNLESS_NET_MPSAFE();
}

static void
arp_dad_duplicated(struct ifaddr *ifa, const struct sockaddr_dl *from)
{
        struct in_ifaddr *ia = ifatoia(ifa);
        struct ifnet *ifp = ifa->ifa_ifp;
        char ipbuf[INET_ADDRSTRLEN], llabuf[LLA_ADDRSTRLEN];
        const char *iastr, *llastr;

        iastr = IN_PRINT(ipbuf, &ia->ia_addr.sin_addr);
        if (__predict_false(from == NULL))
                llastr = NULL;
        else
                llastr = lla_snprintf(llabuf, sizeof(llabuf),
                    CLLADDR(from), from->sdl_alen);

        if (ia->ia4_flags & (IN_IFF_TENTATIVE|IN_IFF_DUPLICATED)) {
                log(LOG_ERR,
                    "%s: DAD duplicate address %s from %s\n",
                    if_name(ifp), iastr, llastr);
        } else if (ia->ia_dad_defended == 0 ||
                   ia->ia_dad_defended < time_uptime - DEFEND_INTERVAL) {
                ia->ia_dad_defended = time_uptime;
                arpannounce1(ifa);
                log(LOG_ERR,
                    "%s: DAD defended address %s from %s\n",
                    if_name(ifp), iastr, llastr);
                return;
        } else {
                /* If DAD is disabled, just report the duplicate. */
                if (!ip_dad_enabled()) {
                        log(LOG_ERR,
                            "%s: DAD ignoring duplicate address %s from %s\n",
                            if_name(ifp), iastr, llastr);
                        return;
                }
                log(LOG_ERR,
                    "%s: DAD defence failed for %s from %s\n",
                    if_name(ifp), iastr, llastr);
        }

        arp_dad_stop(ifa);

        ia->ia4_flags &= ~IN_IFF_TENTATIVE;
        if ((ia->ia4_flags & IN_IFF_DUPLICATED) == 0) {
                ia->ia4_flags |= IN_IFF_DUPLICATED;
                /* Inform the routing socket of the duplicate address */
                rt_addrmsg_src(RTM_NEWADDR, ifa, (const struct sockaddr *)from);
        }
}

/*
 * Called from 10 Mb/s Ethernet interrupt handlers
 * when ether packet type ETHERTYPE_REVARP
 * is received.  Common length and type checks are done here,
 * then the protocol-specific routine is called.
 */
void
revarpinput(struct mbuf *m)
{
        struct arphdr *ar;
        int arplen;

        arplen = sizeof(struct arphdr);
        if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL)
                return;
        ar = mtod(m, struct arphdr *);

        if (ntohs(ar->ar_hrd) == ARPHRD_IEEE1394) {
                goto out;
        }

        arplen = sizeof(struct arphdr) + 2 * (ar->ar_hln + ar->ar_pln);
        if (m->m_len < arplen && (m = m_pullup(m, arplen)) == NULL)
                return;
        ar = mtod(m, struct arphdr *);

        switch (ntohs(ar->ar_pro)) {
        case ETHERTYPE_IP:
        case ETHERTYPE_IPTRAILERS:
                in_revarpinput(m);
                return;

        default:
                break;
        }

out:
        m_freem(m);
}

/*
 * RARP for Internet protocols on 10 Mb/s Ethernet.
 * Algorithm is that given in RFC 903.
 * We are only using for bootstrap purposes to get an ip address for one of
 * our interfaces.  Thus we support no user-interface.
 *
 * Since the contents of the RARP reply are specific to the interface that
 * sent the request, this code must ensure that they are properly associated.
 *
 * Note: also supports ARP via RARP packets, per the RFC.
 */
void
in_revarpinput(struct mbuf *m)
{
        struct arphdr *ah;
        void *tha;
        int op;
        struct ifnet *rcvif;
        int s;

        ah = mtod(m, struct arphdr *);
        op = ntohs(ah->ar_op);

        rcvif = m_get_rcvif(m, &s);
        if (__predict_false(rcvif == NULL))
                goto out;
        if (rcvif->if_flags & IFF_NOARP)
                goto out;

        switch (rcvif->if_type) {
        case IFT_IEEE1394:
                /* ARP without target hardware address is not supported */
                goto out;
        default:
                break;
        }

        switch (op) {
        case ARPOP_REQUEST:
        case ARPOP_REPLY:       /* per RFC */
                m_put_rcvif(rcvif, &s);
                in_arpinput(m);
                return;
        case ARPOP_REVREPLY:
                break;
        case ARPOP_REVREQUEST:  /* handled by rarpd(8) */
        default:
                goto out;
        }
        if (!revarp_in_progress)
                goto out;
        if (rcvif != myip_ifp) /* !same interface */
                goto out;
        if (myip_initialized)
                goto wake;
        tha = ar_tha(ah);
        if (tha == NULL)
                goto out;
        if (ah->ar_pln != sizeof(struct in_addr))
                goto out;
        if (ah->ar_hln != rcvif->if_sadl->sdl_alen)
                goto out;
        if (memcmp(tha, CLLADDR(rcvif->if_sadl), rcvif->if_sadl->sdl_alen))
                goto out;
        memcpy(&srv_ip, ar_spa(ah), sizeof(srv_ip));
        memcpy(&myip, ar_tpa(ah), sizeof(myip));
        myip_initialized = 1;
wake:   /* Do wakeup every time in case it was missed. */
        wakeup((void *)&myip);

out:
        m_put_rcvif(rcvif, &s);
        m_freem(m);
}

/*
 * Send a RARP request for the ip address of the specified interface.
 * The request should be RFC 903-compliant.
 */
static void
revarprequest(struct ifnet *ifp)
{
        struct sockaddr sa;
        struct mbuf *m;
        struct arphdr *ah;
        void *tha;

        if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
                return;
        MCLAIM(m, &arpdomain.dom_mowner);
        m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) +
            2*ifp->if_addrlen;
        m->m_pkthdr.len = m->m_len;
        m_align(m, m->m_len);
        ah = mtod(m, struct arphdr *);
        memset(ah, 0, m->m_len);
        ah->ar_pro = htons(ETHERTYPE_IP);
        ah->ar_hln = ifp->if_addrlen;           /* hardware address length */
        ah->ar_pln = sizeof(struct in_addr);    /* protocol address length */
        ah->ar_op = htons(ARPOP_REVREQUEST);

        memcpy(ar_sha(ah), CLLADDR(ifp->if_sadl), ah->ar_hln);
        tha = ar_tha(ah);
        if (tha == NULL) {
                m_free(m);
                return;
        }
        memcpy(tha, CLLADDR(ifp->if_sadl), ah->ar_hln);

        sa.sa_family = AF_ARP;
        sa.sa_len = 2;
        m->m_flags |= M_BCAST;

        if_output_lock(ifp, ifp, m, &sa, NULL);
}

/*
 * RARP for the ip address of the specified interface, but also
 * save the ip address of the server that sent the answer.
 * Timeout if no response is received.
 */
int
revarpwhoarewe(struct ifnet *ifp, struct in_addr *serv_in,
    struct in_addr *clnt_in)
{
        int result, count = 20;

        myip_initialized = 0;
        myip_ifp = ifp;

        revarp_in_progress = 1;
        while (count--) {
                revarprequest(ifp);
                result = tsleep((void *)&myip, PSOCK, "revarp", hz/2);
                if (result != EWOULDBLOCK)
                        break;
        }
        revarp_in_progress = 0;

        if (!myip_initialized)
                return ENETUNREACH;

        memcpy(serv_in, &srv_ip, sizeof(*serv_in));
        memcpy(clnt_in, &myip, sizeof(*clnt_in));
        return 0;
}

void
arp_stat_add(int type, uint64_t count)
{
        ARP_STATADD(type, count);
}

static int
sysctl_net_inet_arp_stats(SYSCTLFN_ARGS)
{

        return NETSTAT_SYSCTL(arpstat_percpu, ARP_NSTATS);
}

static void
sysctl_net_inet_arp_setup(struct sysctllog **clog)
{
        const struct sysctlnode *node;

        sysctl_createv(clog, 0, NULL, NULL,
                        CTLFLAG_PERMANENT,
                        CTLTYPE_NODE, "inet", NULL,
                        NULL, 0, NULL, 0,
                        CTL_NET, PF_INET, CTL_EOL);
        sysctl_createv(clog, 0, NULL, &node,
                        CTLFLAG_PERMANENT,
                        CTLTYPE_NODE, "arp",
                        SYSCTL_DESCR("Address Resolution Protocol"),
                        NULL, 0, NULL, 0,
                        CTL_NET, PF_INET, CTL_CREATE, CTL_EOL);

        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "nd_delay",
                       SYSCTL_DESCR("First probe delay time"),
                       NULL, 0, &arp_nd_domain.nd_delay, 0,
                       CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "nd_bmaxtries",
                       SYSCTL_DESCR("Number of broadcast discovery attempts"),
                       NULL, 0, &arp_nd_domain.nd_mmaxtries, 0,
                       CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "nd_umaxtries",
                       SYSCTL_DESCR("Number of unicast discovery attempts"),
                       NULL, 0, &arp_nd_domain.nd_umaxtries, 0,
                       CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "nd_reachable",
                       SYSCTL_DESCR("Reachable time"),
                       NULL, 0, &arp_reachable, 0,
                       CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "nd_retrans",
                       SYSCTL_DESCR("Retransmission time"),
                       NULL, 0, &arp_retrans, 0,
                       CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "nd_nud",
                       SYSCTL_DESCR("Perform neighbour unreachability detection"),
                       NULL, 0, &arp_perform_nud, 0,
                       CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "nd_maxnudhint",
                       SYSCTL_DESCR("Maximum neighbor unreachable hint count"),
                       NULL, 0, &arp_nd_domain.nd_maxnudhint, 0,
                       CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "maxqueuelen",
                       SYSCTL_DESCR("max packet queue len for a unresolved ARP"),
                       NULL, 1, &arp_nd_domain.nd_maxqueuelen, 0,
                       CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);

        sysctl_createv(clog, 0, NULL, NULL,
                        CTLFLAG_PERMANENT,
                        CTLTYPE_STRUCT, "stats",
                        SYSCTL_DESCR("ARP statistics"),
                        sysctl_net_inet_arp_stats, 0, NULL, 0,
                        CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);

        sysctl_createv(clog, 0, NULL, NULL,
                        CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                        CTLTYPE_INT, "log_movements",
                        SYSCTL_DESCR("log ARP replies from MACs different than"
                            " the one in the cache"),
                        NULL, 0, &log_movements, 0,
                        CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);

        sysctl_createv(clog, 0, NULL, NULL,
                        CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                        CTLTYPE_INT, "log_permanent_modify",
                        SYSCTL_DESCR("log ARP replies from MACs different than"
                            " the one in the permanent arp entry"),
                        NULL, 0, &log_permanent_modify, 0,
                        CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);

        sysctl_createv(clog, 0, NULL, NULL,
                        CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                        CTLTYPE_INT, "log_wrong_iface",
                        SYSCTL_DESCR("log ARP packets arriving on the wrong"
                            " interface"),
                        NULL, 0, &log_wrong_iface, 0,
                        CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);

        sysctl_createv(clog, 0, NULL, NULL,
                        CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                        CTLTYPE_INT, "debug",
                        SYSCTL_DESCR("Enable ARP DAD debug output"),
                        NULL, 0, &arp_debug, 0,
                        CTL_NET, PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
}

#endif /* INET */