root/sys/netinet6/in6.c
/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * 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 project 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 PROJECT 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 PROJECT 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.
 *
 *      $KAME: in6.c,v 1.259 2002/01/21 11:37:50 keiichi Exp $
 */

/*-
 * Copyright (c) 1982, 1986, 1991, 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.
 */

#include "opt_inet.h"
#include "opt_inet6.h"

#include <sys/param.h>
#include <sys/eventhandler.h>
#include <sys/errno.h>
#include <sys/jail.h>
#include <sys/malloc.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sockio.h>
#include <sys/systm.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/rmlock.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>

#include <net/if.h>
#include <net/if_var.h>
#include <net/if_private.h>
#include <net/if_types.h>
#include <net/if_bridgevar.h>
#include <net/route.h>
#include <net/route/route_ctl.h>
#include <net/route/nhop.h>
#include <net/if_dl.h>
#include <net/vnet.h>

#include <netinet/in.h>
#include <netinet/in_var.h>
#include <net/if_llatbl.h>
#include <netinet/if_ether.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/ip_carp.h>
#include <netinet/icmp6.h>

#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/nd6.h>
#include <netinet6/mld6_var.h>
#include <netinet6/ip6_mroute.h>
#include <netinet6/in6_ifattach.h>
#include <netinet6/scope6_var.h>
#include <netinet6/in6_fib.h>
#include <netinet6/in6_pcb.h>

#ifdef MAC
#include <security/mac/mac_framework.h>
#endif

/*
 * struct in6_ifreq and struct ifreq must be type punnable for common members
 * of ifr_ifru to allow accessors to be shared.
 */
_Static_assert(offsetof(struct in6_ifreq, ifr_ifru) ==
    offsetof(struct ifreq, ifr_ifru),
    "struct in6_ifreq and struct ifreq are not type punnable");

VNET_DEFINE_STATIC(int, icmp6_nodeinfo_oldmcprefix) = 1;
#define V_icmp6_nodeinfo_oldmcprefix    VNET(icmp6_nodeinfo_oldmcprefix)
SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_NODEINFO_OLDMCPREFIX,
    nodeinfo_oldmcprefix, CTLFLAG_VNET | CTLFLAG_RW,
    &VNET_NAME(icmp6_nodeinfo_oldmcprefix), 0,
    "Join old IPv6 NI group address in draft-ietf-ipngwg-icmp-name-lookup "
    "for compatibility with KAME implementation");

VNET_DEFINE_STATIC(int, nd6_useloopback) = 1;
#define V_nd6_useloopback       VNET(nd6_useloopback)
SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_USELOOPBACK, nd6_useloopback,
    CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_useloopback), 0,
    "Create a loopback route when configuring an IPv6 address");

/*
 * Definitions of some costant IP6 addresses.
 */
const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
const struct in6_addr in6addr_nodelocal_allnodes =
        IN6ADDR_NODELOCAL_ALLNODES_INIT;
const struct in6_addr in6addr_linklocal_allnodes =
        IN6ADDR_LINKLOCAL_ALLNODES_INIT;
const struct in6_addr in6addr_linklocal_allrouters =
        IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
const struct in6_addr in6addr_linklocal_allv2routers =
        IN6ADDR_LINKLOCAL_ALLV2ROUTERS_INIT;

const struct in6_addr in6mask0 = IN6MASK0;
const struct in6_addr in6mask32 = IN6MASK32;
const struct in6_addr in6mask64 = IN6MASK64;
const struct in6_addr in6mask96 = IN6MASK96;
const struct in6_addr in6mask128 = IN6MASK128;

const struct sockaddr_in6 sa6_any =
        { sizeof(sa6_any), AF_INET6, 0, 0, IN6ADDR_ANY_INIT, 0 };

static int in6_notify_ifa(struct ifnet *, struct in6_ifaddr *,
        struct in6_aliasreq *, int);
static void in6_unlink_ifa(struct in6_ifaddr *, struct ifnet *);

static int in6_validate_ifra(struct ifnet *, struct in6_aliasreq *,
    struct in6_ifaddr *, int);
static struct in6_ifaddr *in6_alloc_ifa(struct ifnet *,
    struct in6_aliasreq *, int flags);
static int in6_update_ifa_internal(struct ifnet *, struct in6_aliasreq *,
    struct in6_ifaddr *, int, int);
static int in6_broadcast_ifa(struct ifnet *, struct in6_aliasreq *,
    struct in6_ifaddr *, int);

static void in6_join_proxy_ndp_mc(struct ifnet *, const struct in6_addr *);
static void in6_leave_proxy_ndp_mc(struct ifnet *, const struct in6_addr *);

#define ifa2ia6(ifa)    ((struct in6_ifaddr *)(ifa))
#define ia62ifa(ia6)    (&((ia6)->ia_ifa))

static struct sx in6_control_sx;
SX_SYSINIT(in6_control_sx, &in6_control_sx, "in6_control");

void
in6_newaddrmsg(struct in6_ifaddr *ia, int cmd)
{
        struct rt_addrinfo info;
        struct ifaddr *ifa;
        struct sockaddr_dl gateway;
        int fibnum;

        ifa = &ia->ia_ifa;

        /*
         * Prepare info data for the host route.
         * This code mimics one from ifa_maintain_loopback_route().
         */
        bzero(&info, sizeof(struct rt_addrinfo));
        info.rti_flags = ifa->ifa_flags | RTF_HOST | RTF_STATIC | RTF_PINNED;
        info.rti_info[RTAX_DST] = ifa->ifa_addr;
        info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&gateway;
        link_init_sdl(ifa->ifa_ifp, (struct sockaddr *)&gateway, ifa->ifa_ifp->if_type);
        if (cmd != RTM_DELETE)
                info.rti_ifp = V_loif;

        fibnum = ia62ifa(ia)->ifa_ifp->if_fib;

        if (cmd == RTM_ADD) {
                rt_addrmsg(cmd, &ia->ia_ifa, fibnum);
                rt_routemsg_info(cmd, &info, fibnum);
        } else if (cmd == RTM_DELETE) {
                rt_routemsg_info(cmd, &info, fibnum);
                rt_addrmsg(cmd, &ia->ia_ifa, fibnum);
        }
}

int
in6_mask2len(struct in6_addr *mask, u_char *lim0)
{
        int x = 0, y;
        u_char *lim = lim0, *p;

        /* ignore the scope_id part */
        if (lim0 == NULL || lim0 - (u_char *)mask > sizeof(*mask))
                lim = (u_char *)mask + sizeof(*mask);
        for (p = (u_char *)mask; p < lim; x++, p++) {
                if (*p != 0xff)
                        break;
        }
        y = 0;
        if (p < lim) {
                for (y = 0; y < 8; y++) {
                        if ((*p & (0x80 >> y)) == 0)
                                break;
                }
        }

        /*
         * when the limit pointer is given, do a stricter check on the
         * remaining bits.
         */
        if (p < lim) {
                if (y != 0 && (*p & (0x00ff >> y)) != 0)
                        return (-1);
                for (p = p + 1; p < lim; p++)
                        if (*p != 0)
                                return (-1);
        }

        return x * 8 + y;
}

#ifdef COMPAT_FREEBSD32
struct in6_ndifreq32 {
        char ifname[IFNAMSIZ];
        uint32_t ifindex;
};
#define SIOCGDEFIFACE32_IN6     _IOWR('i', 86, struct in6_ndifreq32)
#endif

int
in6_control_ioctl(u_long cmd, void *data,
    struct ifnet *ifp, struct ucred *cred)
{
        struct  in6_ifreq *ifr = (struct in6_ifreq *)data;
        struct  in6_ifaddr *ia = NULL;
        struct  in6_aliasreq *ifra = (struct in6_aliasreq *)data;
        struct sockaddr_in6 *sa6;
        int error;
        bool control_locked = false;

        /*
         * Compat to make pre-10.x ifconfig(8) operable.
         */
        if (cmd == OSIOCAIFADDR_IN6) {
                cmd = SIOCAIFADDR_IN6;
                ifra->ifra_vhid = 0;
        }

        switch (cmd) {
        case SIOCAADDRCTL_POLICY:
        case SIOCDADDRCTL_POLICY:
                if (cred != NULL) {
                        error = priv_check_cred(cred, PRIV_NETINET_ADDRCTRL6);
                        if (error)
                                return (error);
                }
                return (in6_src_ioctl(cmd, data));
        }

        if (ifp == NULL)
                return (EOPNOTSUPP);

        switch (cmd) {
        case SIOCSNDFLUSH_IN6:
        case SIOCSPFXFLUSH_IN6:
        case SIOCSRTRFLUSH_IN6:
        case SIOCSDEFIFACE_IN6:
        case SIOCSIFINFO_FLAGS:
        case SIOCSIFINFO_IN6:
                if (cred != NULL) {
                        error = priv_check_cred(cred, PRIV_NETINET_ND6);
                        if (error)
                                return (error);
                }
                /* FALLTHROUGH */
        case SIOCGIFINFO_IN6:
        case SIOCGNBRINFO_IN6:
        case SIOCGDEFIFACE_IN6:
                return (nd6_ioctl(cmd, data, ifp));

#ifdef COMPAT_FREEBSD32
        case SIOCGDEFIFACE32_IN6:
                {
                        struct in6_ndifreq ndif;
                        struct in6_ndifreq32 *ndif32;

                        error = nd6_ioctl(SIOCGDEFIFACE_IN6, (caddr_t)&ndif,
                            ifp);
                        if (error)
                                return (error);
                        ndif32 = (struct in6_ndifreq32 *)data;
                        ndif32->ifindex = ndif.ifindex;
                        return (0);
                }
#endif
        }

        switch (cmd) {
        case SIOCSIFPREFIX_IN6:
        case SIOCDIFPREFIX_IN6:
        case SIOCAIFPREFIX_IN6:
        case SIOCCIFPREFIX_IN6:
        case SIOCSGIFPREFIX_IN6:
        case SIOCGIFPREFIX_IN6:
                log(LOG_NOTICE,
                    "prefix ioctls are now invalidated. "
                    "please use ifconfig.\n");
                return (EOPNOTSUPP);
        }

        switch (cmd) {
        case SIOCSSCOPE6:
                if (cred != NULL) {
                        error = priv_check_cred(cred, PRIV_NETINET_SCOPE6);
                        if (error)
                                return (error);
                }
                /* FALLTHROUGH */
        case SIOCGSCOPE6:
        case SIOCGSCOPE6DEF:
                return (scope6_ioctl(cmd, data, ifp));
        }

        /*
         * Find address for this interface, if it exists.
         *
         * In netinet code, we have checked ifra_addr in SIOCSIF*ADDR operation
         * only, and used the first interface address as the target of other
         * operations (without checking ifra_addr).  This was because netinet
         * code/API assumed at most 1 interface address per interface.
         * Since IPv6 allows a node to assign multiple addresses
         * on a single interface, we almost always look and check the
         * presence of ifra_addr, and reject invalid ones here.
         * It also decreases duplicated code among SIOC*_IN6 operations.
         */
        switch (cmd) {
        case SIOCAIFADDR_IN6:
        case SIOCSIFPHYADDR_IN6:
                sa6 = &ifra->ifra_addr;
                break;
        case SIOCSIFADDR_IN6:
        case SIOCGIFADDR_IN6:
        case SIOCSIFDSTADDR_IN6:
        case SIOCSIFNETMASK_IN6:
        case SIOCGIFDSTADDR_IN6:
        case SIOCGIFNETMASK_IN6:
        case SIOCDIFADDR_IN6:
        case SIOCGIFPSRCADDR_IN6:
        case SIOCGIFPDSTADDR_IN6:
        case SIOCGIFAFLAG_IN6:
        case SIOCSNDFLUSH_IN6:
        case SIOCSPFXFLUSH_IN6:
        case SIOCSRTRFLUSH_IN6:
        case SIOCGIFALIFETIME_IN6:
        case SIOCGIFSTAT_IN6:
        case SIOCGIFSTAT_ICMP6:
                sa6 = &ifr->ifr_addr;
                break;
        case SIOCSIFADDR:
        case SIOCSIFBRDADDR:
        case SIOCSIFDSTADDR:
        case SIOCSIFNETMASK:
                /*
                 * Although we should pass any non-INET6 ioctl requests
                 * down to driver, we filter some legacy INET requests.
                 * Drivers trust SIOCSIFADDR et al to come from an already
                 * privileged layer, and do not perform any credentials
                 * checks or input validation.
                 */
                return (EINVAL);
        default:
                sa6 = NULL;
                break;
        }
        if (sa6 && sa6->sin6_family == AF_INET6) {
                if (sa6->sin6_scope_id != 0)
                        error = sa6_embedscope(sa6, 0);
                else
                        error = in6_setscope(&sa6->sin6_addr, ifp, NULL);
                if (error != 0)
                        return (error);
                if (cred != NULL && (error = prison_check_ip6(cred,
                    &sa6->sin6_addr)) != 0)
                        return (error);
                sx_xlock(&in6_control_sx);
                control_locked = true;
                ia = in6ifa_ifpwithaddr(ifp, &sa6->sin6_addr);
        } else
                ia = NULL;

        switch (cmd) {
        case SIOCSIFADDR_IN6:
        case SIOCSIFDSTADDR_IN6:
        case SIOCSIFNETMASK_IN6:
                /*
                 * Since IPv6 allows a node to assign multiple addresses
                 * on a single interface, SIOCSIFxxx ioctls are deprecated.
                 */
                /* we decided to obsolete this command (20000704) */
                error = EINVAL;
                goto out;

        case SIOCDIFADDR_IN6:
                /*
                 * for IPv4, we look for existing in_ifaddr here to allow
                 * "ifconfig if0 delete" to remove the first IPv4 address on
                 * the interface.  For IPv6, as the spec allows multiple
                 * interface address from the day one, we consider "remove the
                 * first one" semantics to be not preferable.
                 */
                if (ia == NULL) {
                        error = EADDRNOTAVAIL;
                        goto out;
                }
                /* FALLTHROUGH */
        case SIOCAIFADDR_IN6:
                /*
                 * We always require users to specify a valid IPv6 address for
                 * the corresponding operation.
                 */
                if (ifra->ifra_addr.sin6_family != AF_INET6 ||
                    ifra->ifra_addr.sin6_len != sizeof(struct sockaddr_in6)) {
                        error = EAFNOSUPPORT;
                        goto out;
                }

                if (cred != NULL) {
                        error = priv_check_cred(cred, (cmd == SIOCDIFADDR_IN6) ?
                            PRIV_NET_DELIFADDR : PRIV_NET_ADDIFADDR);
                        if (error)
                                goto out;
                }
                /* FALLTHROUGH */
        case SIOCGIFSTAT_IN6:
        case SIOCGIFSTAT_ICMP6:
                if (ifp->if_inet6 == NULL) {
                        error = EPFNOSUPPORT;
                        goto out;
                }
                break;

        case SIOCGIFADDR_IN6:
                /* This interface is basically deprecated. use SIOCGIFCONF. */
                /* FALLTHROUGH */
        case SIOCGIFAFLAG_IN6:
        case SIOCGIFNETMASK_IN6:
        case SIOCGIFDSTADDR_IN6:
        case SIOCGIFALIFETIME_IN6:
                /* must think again about its semantics */
                if (ia == NULL) {
                        error = EADDRNOTAVAIL;
                        goto out;
                }
                break;
        }

        switch (cmd) {
        case SIOCGIFADDR_IN6:
                ifr->ifr_addr = ia->ia_addr;
                if ((error = sa6_recoverscope(&ifr->ifr_addr)) != 0)
                        goto out;
                break;

        case SIOCGIFDSTADDR_IN6:
                if ((ifp->if_flags & IFF_POINTOPOINT) == 0) {
                        error = EINVAL;
                        goto out;
                }
                ifr->ifr_dstaddr = ia->ia_dstaddr;
                if ((error = sa6_recoverscope(&ifr->ifr_dstaddr)) != 0)
                        goto out;
                break;

        case SIOCGIFNETMASK_IN6:
                ifr->ifr_addr = ia->ia_prefixmask;
                break;

        case SIOCGIFAFLAG_IN6:
                ifr->ifr_ifru.ifru_flags6 = ia->ia6_flags;
                break;

        case SIOCGIFSTAT_IN6:
                COUNTER_ARRAY_COPY(ifp->if_inet6->in6_ifstat,
                    &ifr->ifr_ifru.ifru_stat,
                    sizeof(struct in6_ifstat) / sizeof(uint64_t));
                break;

        case SIOCGIFSTAT_ICMP6:
                COUNTER_ARRAY_COPY(ifp->if_inet6->icmp6_ifstat,
                    &ifr->ifr_ifru.ifru_icmp6stat,
                    sizeof(struct icmp6_ifstat) / sizeof(uint64_t));
                break;

        case SIOCGIFALIFETIME_IN6:
                ifr->ifr_ifru.ifru_lifetime = ia->ia6_lifetime;
                if (ia->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
                        time_t maxexpire;
                        struct in6_addrlifetime *retlt =
                            &ifr->ifr_ifru.ifru_lifetime;

                        /*
                         * XXX: adjust expiration time assuming time_t is
                         * signed.
                         */
                        maxexpire = (-1) &
                            ~((time_t)1 << ((sizeof(maxexpire) * 8) - 1));
                        if (ia->ia6_lifetime.ia6t_vltime <
                            maxexpire - ia->ia6_updatetime) {
                                retlt->ia6t_expire = ia->ia6_updatetime +
                                    ia->ia6_lifetime.ia6t_vltime;
                        } else
                                retlt->ia6t_expire = maxexpire;
                }
                if (ia->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
                        time_t maxexpire;
                        struct in6_addrlifetime *retlt =
                            &ifr->ifr_ifru.ifru_lifetime;

                        /*
                         * XXX: adjust expiration time assuming time_t is
                         * signed.
                         */
                        maxexpire = (-1) &
                            ~((time_t)1 << ((sizeof(maxexpire) * 8) - 1));
                        if (ia->ia6_lifetime.ia6t_pltime <
                            maxexpire - ia->ia6_updatetime) {
                                retlt->ia6t_preferred = ia->ia6_updatetime +
                                    ia->ia6_lifetime.ia6t_pltime;
                        } else
                                retlt->ia6t_preferred = maxexpire;
                }
                break;

        case SIOCAIFADDR_IN6:
#ifdef MAC
                /* Check if a MAC policy disallows setting the IPv6 address. */
                error = mac_inet6_check_add_addr(cred, &sa6->sin6_addr, ifp);
                if (error != 0)
                        goto out;
#endif
                error = in6_addifaddr(ifp, ifra, ia);
                ia = NULL;
                goto out;

        case SIOCDIFADDR_IN6:
                in6_purgeifaddr(ia);
                EVENTHANDLER_INVOKE(ifaddr_event_ext, ifp, &ia->ia_ifa,
                    IFADDR_EVENT_DEL);
                break;

        default:
                if (ifp->if_ioctl == NULL) {
                        error = EOPNOTSUPP;
                        goto out;
                }
                error = (*ifp->if_ioctl)(ifp, cmd, data);
                goto out;
        }

        error = 0;
out:
        if (control_locked)
                sx_xunlock(&in6_control_sx);

        if (ia != NULL)
                ifa_free(&ia->ia_ifa);
        return (error);
}

int
in6_control(struct socket *so, u_long cmd, void *data,
    struct ifnet *ifp, struct thread *td)
{
        switch (cmd) {
        case SIOCGETSGCNT_IN6:
        case SIOCGETMIFCNT_IN6:
                return (mrt6_ioctl ?
                    mrt6_ioctl(cmd, data, so->so_fibnum) : EOPNOTSUPP);
        }
        return (in6_control_ioctl(cmd, data, ifp, td ? td->td_ucred : NULL));
}

static struct in6_multi_mship *
in6_joingroup_legacy(struct ifnet *ifp, const struct in6_addr *mcaddr,
    int *errorp, int delay)
{
        struct in6_multi_mship *imm;
        int error;

        imm = malloc(sizeof(*imm), M_IP6MADDR, M_NOWAIT);
        if (imm == NULL) {
                *errorp = ENOBUFS;
                return (NULL);
        }

        delay = (delay * MLD_FASTHZ) / hz;

        error = in6_joingroup(ifp, mcaddr, NULL, &imm->i6mm_maddr, delay);
        if (error) {
                *errorp = error;
                free(imm, M_IP6MADDR);
                return (NULL);
        }

        return (imm);
}

static int
in6_solicited_node_maddr(struct in6_addr *maddr,
    struct ifnet *ifp, const struct in6_addr *base)
{
        int error;

        bzero(maddr, sizeof(struct in6_addr));
        maddr->s6_addr32[0] = IPV6_ADDR_INT32_MLL;
        maddr->s6_addr32[2] = htonl(1);
        maddr->s6_addr32[3] = base->s6_addr32[3];
        maddr->s6_addr8[12] = 0xff;
        if ((error = in6_setscope(maddr, ifp, NULL)) != 0) {
                /* XXX: should not happen */
                log(LOG_ERR, "%s: in6_setscope failed\n", __func__);
        }

        return error;
}

/*
 * Join necessary multicast groups.  Factored out from in6_update_ifa().
 * This entire work should only be done once, for the default FIB.
 */
static int
in6_update_ifa_join_mc(struct ifnet *ifp, struct in6_aliasreq *ifra,
    struct in6_ifaddr *ia, int flags, struct in6_multi **in6m_sol)
{
        char ip6buf[INET6_ADDRSTRLEN];
        struct in6_addr mltaddr;
        struct in6_multi_mship *imm;
        int delay, error;

        KASSERT(in6m_sol != NULL, ("%s: in6m_sol is NULL", __func__));

        /* Join solicited multicast addr for new host id. */
        if ((error = in6_solicited_node_maddr(&mltaddr, ifp,
            &ifra->ifra_addr.sin6_addr)) != 0)
                goto cleanup;
        delay = error = 0;
        if ((flags & IN6_IFAUPDATE_DADDELAY)) {
                /*
                 * We need a random delay for DAD on the address being
                 * configured.  It also means delaying transmission of the
                 * corresponding MLD report to avoid report collision.
                 * [RFC 4861, Section 6.3.7]
                 */
                delay = arc4random() % (MAX_RTR_SOLICITATION_DELAY * hz);
        }
        imm = in6_joingroup_legacy(ifp, &mltaddr, &error, delay);
        if (imm == NULL) {
                nd6log((LOG_WARNING, "%s: in6_joingroup failed for %s on %s "
                    "(errno=%d)\n", __func__, ip6_sprintf(ip6buf, &mltaddr),
                    if_name(ifp), error));
                goto cleanup;
        }
        LIST_INSERT_HEAD(&ia->ia6_memberships, imm, i6mm_chain);
        *in6m_sol = imm->i6mm_maddr;

        /*
         * Join link-local all-nodes address.
         */
        mltaddr = in6addr_linklocal_allnodes;
        if ((error = in6_setscope(&mltaddr, ifp, NULL)) != 0)
                goto cleanup; /* XXX: should not fail */

        imm = in6_joingroup_legacy(ifp, &mltaddr, &error, 0);
        if (imm == NULL) {
                nd6log((LOG_WARNING, "%s: in6_joingroup failed for %s on %s "
                    "(errno=%d)\n", __func__, ip6_sprintf(ip6buf, &mltaddr),
                    if_name(ifp), error));
                goto cleanup;
        }
        LIST_INSERT_HEAD(&ia->ia6_memberships, imm, i6mm_chain);

        /*
         * Join node information group address.
         */
        delay = 0;
        if ((flags & IN6_IFAUPDATE_DADDELAY)) {
                /*
                 * The spec does not say anything about delay for this group,
                 * but the same logic should apply.
                 */
                delay = arc4random() % (MAX_RTR_SOLICITATION_DELAY * hz);
        }
        if (in6_nigroup(ifp, NULL, -1, &mltaddr) == 0) {
                /* XXX jinmei */
                imm = in6_joingroup_legacy(ifp, &mltaddr, &error, delay);
                if (imm == NULL)
                        nd6log((LOG_WARNING,
                            "%s: in6_joingroup failed for %s on %s "
                            "(errno=%d)\n", __func__, ip6_sprintf(ip6buf,
                            &mltaddr), if_name(ifp), error));
                        /* XXX not very fatal, go on... */
                else
                        LIST_INSERT_HEAD(&ia->ia6_memberships, imm, i6mm_chain);
        }
        if (V_icmp6_nodeinfo_oldmcprefix &&
            in6_nigroup_oldmcprefix(ifp, NULL, -1, &mltaddr) == 0) {
                imm = in6_joingroup_legacy(ifp, &mltaddr, &error, delay);
                if (imm == NULL)
                        nd6log((LOG_WARNING,
                            "%s: in6_joingroup failed for %s on %s "
                            "(errno=%d)\n", __func__, ip6_sprintf(ip6buf,
                            &mltaddr), if_name(ifp), error));
                        /* XXX not very fatal, go on... */
                else
                        LIST_INSERT_HEAD(&ia->ia6_memberships, imm, i6mm_chain);
        }

        /*
         * Join interface-local all-nodes address.
         * (ff01::1%ifN, and ff01::%ifN/32)
         */
        mltaddr = in6addr_nodelocal_allnodes;
        if ((error = in6_setscope(&mltaddr, ifp, NULL)) != 0)
                goto cleanup; /* XXX: should not fail */

        imm = in6_joingroup_legacy(ifp, &mltaddr, &error, 0);
        if (imm == NULL) {
                nd6log((LOG_WARNING, "%s: in6_joingroup failed for %s on %s "
                    "(errno=%d)\n", __func__, ip6_sprintf(ip6buf,
                    &mltaddr), if_name(ifp), error));
                goto cleanup;
        }
        LIST_INSERT_HEAD(&ia->ia6_memberships, imm, i6mm_chain);

cleanup:
        return (error);
}

/*
 * Update parameters of an IPv6 interface address.
 * If necessary, a new entry is created and linked into address chains.
 * This function is separated from in6_control().
 */
int
in6_update_ifa(struct ifnet *ifp, struct in6_aliasreq *ifra,
    struct in6_ifaddr *ia, int flags)
{
        int error, hostIsNew = 0;

        if ((error = in6_validate_ifra(ifp, ifra, ia, flags)) != 0)
                return (error);

        if (ia == NULL) {
                hostIsNew = 1;
                if ((ia = in6_alloc_ifa(ifp, ifra, flags)) == NULL)
                        return (ENOBUFS);
        }

        error = in6_update_ifa_internal(ifp, ifra, ia, hostIsNew, flags);
        if (error != 0) {
                if (hostIsNew != 0) {
                        in6_unlink_ifa(ia, ifp);
                        ifa_free(&ia->ia_ifa);
                }
                return (error);
        }

        if (hostIsNew)
                error = in6_broadcast_ifa(ifp, ifra, ia, flags);

        return (error);
}

/*
 * Fill in basic IPv6 address request info.
 */
void
in6_prepare_ifra(struct in6_aliasreq *ifra, const struct in6_addr *addr,
    const struct in6_addr *mask)
{

        memset(ifra, 0, sizeof(struct in6_aliasreq));

        ifra->ifra_addr.sin6_family = AF_INET6;
        ifra->ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
        if (addr != NULL)
                ifra->ifra_addr.sin6_addr = *addr;

        ifra->ifra_prefixmask.sin6_family = AF_INET6;
        ifra->ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
        if (mask != NULL)
                ifra->ifra_prefixmask.sin6_addr = *mask;
}

static int
in6_validate_ifra(struct ifnet *ifp, struct in6_aliasreq *ifra,
    struct in6_ifaddr *ia, int flags)
{
        int plen = -1;
        struct sockaddr_in6 dst6;
        struct in6_addrlifetime *lt;
        char ip6buf[INET6_ADDRSTRLEN];

        /* Validate parameters */
        if (ifp == NULL || ifra == NULL) /* this maybe redundant */
                return (EINVAL);

        /*
         * The destination address for a p2p link must have a family
         * of AF_UNSPEC or AF_INET6.
         */
        if ((ifp->if_flags & IFF_POINTOPOINT) != 0 &&
            ifra->ifra_dstaddr.sin6_family != AF_INET6 &&
            ifra->ifra_dstaddr.sin6_family != AF_UNSPEC)
                return (EAFNOSUPPORT);

        /*
         * Validate address
         */
        if (ifra->ifra_addr.sin6_len != sizeof(struct sockaddr_in6) ||
            ifra->ifra_addr.sin6_family != AF_INET6)
                return (EINVAL);

        /*
         * validate ifra_prefixmask.  don't check sin6_family, netmask
         * does not carry fields other than sin6_len.
         */
        if (ifra->ifra_prefixmask.sin6_len > sizeof(struct sockaddr_in6))
                return (EINVAL);
        /*
         * Because the IPv6 address architecture is classless, we require
         * users to specify a (non 0) prefix length (mask) for a new address.
         * We also require the prefix (when specified) mask is valid, and thus
         * reject a non-consecutive mask.
         */
        if (ia == NULL && ifra->ifra_prefixmask.sin6_len == 0)
                return (EINVAL);
        if (ifra->ifra_prefixmask.sin6_len != 0) {
                plen = in6_mask2len(&ifra->ifra_prefixmask.sin6_addr,
                    (u_char *)&ifra->ifra_prefixmask +
                    ifra->ifra_prefixmask.sin6_len);
                if (plen <= 0)
                        return (EINVAL);
        } else {
                /*
                 * In this case, ia must not be NULL.  We just use its prefix
                 * length.
                 */
                plen = in6_mask2len(&ia->ia_prefixmask.sin6_addr, NULL);
        }
        /*
         * If the destination address on a p2p interface is specified,
         * and the address is a scoped one, validate/set the scope
         * zone identifier.
         */
        dst6 = ifra->ifra_dstaddr;
        if ((ifp->if_flags & (IFF_POINTOPOINT|IFF_LOOPBACK)) != 0 &&
            (dst6.sin6_family == AF_INET6)) {
                struct in6_addr in6_tmp;
                u_int32_t zoneid;

                in6_tmp = dst6.sin6_addr;
                if (in6_setscope(&in6_tmp, ifp, &zoneid))
                        return (EINVAL); /* XXX: should be impossible */

                if (dst6.sin6_scope_id != 0) {
                        if (dst6.sin6_scope_id != zoneid)
                                return (EINVAL);
                } else          /* user omit to specify the ID. */
                        dst6.sin6_scope_id = zoneid;

                /* convert into the internal form */
                if (sa6_embedscope(&dst6, 0))
                        return (EINVAL); /* XXX: should be impossible */
        }
        /* Modify original ifra_dstaddr to reflect changes */
        ifra->ifra_dstaddr = dst6;

        /*
         * The destination address can be specified only for a p2p or a
         * loopback interface.  If specified, the corresponding prefix length
         * must be 128.
         */
        if (ifra->ifra_dstaddr.sin6_family == AF_INET6) {
                if ((ifp->if_flags & (IFF_POINTOPOINT|IFF_LOOPBACK)) == 0) {
                        /* XXX: noisy message */
                        nd6log((LOG_INFO, "in6_update_ifa: a destination can "
                            "be specified for a p2p or a loopback IF only\n"));
                        return (EINVAL);
                }
                if (plen != 128) {
                        nd6log((LOG_INFO, "in6_update_ifa: prefixlen should "
                            "be 128 when dstaddr is specified\n"));
                        return (EINVAL);
                }
        }
        /* lifetime consistency check */
        lt = &ifra->ifra_lifetime;
        if (lt->ia6t_pltime > lt->ia6t_vltime)
                return (EINVAL);
        if (lt->ia6t_vltime == 0) {
                /*
                 * the following log might be noisy, but this is a typical
                 * configuration mistake or a tool's bug.
                 */
                nd6log((LOG_INFO,
                    "in6_update_ifa: valid lifetime is 0 for %s\n",
                    ip6_sprintf(ip6buf, &ifra->ifra_addr.sin6_addr)));

                if (ia == NULL)
                        return (0); /* there's nothing to do */
        }

        /* Check prefix mask */
        if (ia != NULL && ifra->ifra_prefixmask.sin6_len != 0) {
                /*
                 * We prohibit changing the prefix length of an existing
                 * address, because
                 * + such an operation should be rare in IPv6, and
                 * + the operation would confuse prefix management.
                 */
                if (ia->ia_prefixmask.sin6_len != 0 &&
                    in6_mask2len(&ia->ia_prefixmask.sin6_addr, NULL) != plen) {
                        nd6log((LOG_INFO, "in6_validate_ifa: the prefix length "
                            "of an existing %s address should not be changed\n",
                            ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));

                        return (EINVAL);
                }
        }

        return (0);
}

/*
 * Allocate a new ifaddr and link it into chains.
 */
static struct in6_ifaddr *
in6_alloc_ifa(struct ifnet *ifp, struct in6_aliasreq *ifra, int flags)
{
        struct in6_ifaddr *ia;

        /*
         * When in6_alloc_ifa() is called in a process of a received
         * RA, it is called under an interrupt context.  So, we should
         * call malloc with M_NOWAIT.
         */
        ia = (struct in6_ifaddr *)ifa_alloc(sizeof(*ia), M_NOWAIT);
        if (ia == NULL)
                return (NULL);
        LIST_INIT(&ia->ia6_memberships);
        /* Initialize the address and masks, and put time stamp */
        ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
        ia->ia_addr.sin6_family = AF_INET6;
        ia->ia_addr.sin6_len = sizeof(ia->ia_addr);
        /* XXX: Can we assign ,sin6_addr and skip the rest? */
        ia->ia_addr = ifra->ifra_addr;
        ia->ia6_createtime = time_uptime;
        if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) != 0) {
                /*
                 * Some functions expect that ifa_dstaddr is not
                 * NULL for p2p interfaces.
                 */
                ia->ia_ifa.ifa_dstaddr =
                    (struct sockaddr *)&ia->ia_dstaddr;
        } else {
                ia->ia_ifa.ifa_dstaddr = NULL;
        }

        /* set prefix mask if any */
        ia->ia_ifa.ifa_netmask = (struct sockaddr *)&ia->ia_prefixmask;
        if (ifra->ifra_prefixmask.sin6_len != 0) {
                ia->ia_prefixmask.sin6_family = AF_INET6;
                ia->ia_prefixmask.sin6_len = ifra->ifra_prefixmask.sin6_len;
                ia->ia_prefixmask.sin6_addr = ifra->ifra_prefixmask.sin6_addr;
        }

        ia->ia_ifp = ifp;
        ifa_ref(&ia->ia_ifa);                   /* if_addrhead */
        IF_ADDR_WLOCK(ifp);
        CK_STAILQ_INSERT_TAIL(&ifp->if_addrhead, &ia->ia_ifa, ifa_link);
        IF_ADDR_WUNLOCK(ifp);

        ifa_ref(&ia->ia_ifa);                   /* in6_ifaddrhead */
        IN6_IFADDR_WLOCK();
        CK_STAILQ_INSERT_TAIL(&V_in6_ifaddrhead, ia, ia_link);
        CK_LIST_INSERT_HEAD(IN6ADDR_HASH(&ia->ia_addr.sin6_addr), ia, ia6_hash);
        IN6_IFADDR_WUNLOCK();

        return (ia);
}

time_t
in6_expire_time(uint32_t ltime)
{
        if (ltime == ND6_INFINITE_LIFETIME)
                return (0);
        else
                return (time_uptime + ltime);
}

/*
 * Update/configure interface address parameters:
 *
 * 1) Update lifetime
 * 2) Update interface metric ad flags
 * 3) Notify other subsystems
 */
static int
in6_update_ifa_internal(struct ifnet *ifp, struct in6_aliasreq *ifra,
    struct in6_ifaddr *ia, int hostIsNew, int flags)
{
        int error;

        /* update timestamp */
        ia->ia6_updatetime = time_uptime;

        /*
         * Set lifetimes.  We do not refer to ia6t_expire and ia6t_preferred
         * to see if the address is deprecated or invalidated, but initialize
         * these members for applications.
         */
        ia->ia6_lifetime = ifra->ifra_lifetime;
        ia->ia6_lifetime.ia6t_expire =
            in6_expire_time(ifra->ifra_lifetime.ia6t_vltime);
        ia->ia6_lifetime.ia6t_preferred =
            in6_expire_time(ifra->ifra_lifetime.ia6t_pltime);

        /*
         * backward compatibility - if IN6_IFF_DEPRECATED is set from the
         * userland, make it deprecated.
         */
        if ((ifra->ifra_flags & IN6_IFF_DEPRECATED) != 0) {
                ia->ia6_lifetime.ia6t_pltime = 0;
                ia->ia6_lifetime.ia6t_preferred = time_uptime;
        }

        /*
         * configure address flags.
         */
        ia->ia6_flags = ifra->ifra_flags;

        /*
         * Make the address tentative before joining multicast addresses,
         * so that corresponding MLD responses would not have a tentative
         * source address.
         */
        ia->ia6_flags &= ~IN6_IFF_DUPLICATED;   /* safety */

        /*
         * DAD should be performed for an new address or addresses on
         * an interface with ND6_IFF_IFDISABLED.
         */
        if (in6if_do_dad(ifp) &&
            (hostIsNew || (ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED)))
                ia->ia6_flags |= IN6_IFF_TENTATIVE;

        /* notify other subsystems */
        error = in6_notify_ifa(ifp, ia, ifra, hostIsNew);

        return (error);
}

/*
 * Do link-level ifa job:
 * 1) Add lle entry for added address
 * 2) Notifies routing socket users about new address
 * 3) join appropriate multicast group
 * 4) start DAD if enabled
 */
static int
in6_broadcast_ifa(struct ifnet *ifp, struct in6_aliasreq *ifra,
    struct in6_ifaddr *ia, int flags)
{
        struct in6_multi *in6m_sol;
        int error = 0;

        /* Add local address to lltable, if necessary (ex. on p2p link). */
        if ((error = nd6_add_ifa_lle(ia)) != 0) {
                in6_purgeaddr(&ia->ia_ifa);
                ifa_free(&ia->ia_ifa);
                return (error);
        }

        /* Join necessary multicast groups. */
        in6m_sol = NULL;
        if ((ifp->if_flags & IFF_MULTICAST) != 0) {
                error = in6_update_ifa_join_mc(ifp, ifra, ia, flags, &in6m_sol);
                if (error != 0) {
                        in6_purgeaddr(&ia->ia_ifa);
                        ifa_free(&ia->ia_ifa);
                        return (error);
                }
        }

        /* Perform DAD, if the address is TENTATIVE. */
        if ((ia->ia6_flags & IN6_IFF_TENTATIVE)) {
                int delay, mindelay, maxdelay;

                delay = 0;
                if ((flags & IN6_IFAUPDATE_DADDELAY)) {
                        /*
                         * We need to impose a delay before sending an NS
                         * for DAD.  Check if we also needed a delay for the
                         * corresponding MLD message.  If we did, the delay
                         * should be larger than the MLD delay (this could be
                         * relaxed a bit, but this simple logic is at least
                         * safe).
                         * XXX: Break data hiding guidelines and look at
                         * state for the solicited multicast group.
                         */
                        mindelay = 0;
                        if (in6m_sol != NULL &&
                            in6m_sol->in6m_state == MLD_REPORTING_MEMBER) {
                                mindelay = in6m_sol->in6m_timer;
                        }
                        maxdelay = MAX_RTR_SOLICITATION_DELAY * hz;
                        if (maxdelay - mindelay == 0)
                                delay = 0;
                        else {
                                delay =
                                    (arc4random() % (maxdelay - mindelay)) +
                                    mindelay;
                        }
                }
                nd6_dad_start((struct ifaddr *)ia, delay);
        }

        in6_newaddrmsg(ia, RTM_ADD);
        ifa_free(&ia->ia_ifa);
        return (error);
}

/*
 * Adds or deletes interface route for p2p ifa.
 * Returns 0 on success or errno.
 */
static int
in6_handle_dstaddr_rtrequest(int cmd, struct in6_ifaddr *ia)
{
        struct epoch_tracker et;
        struct ifaddr *ifa = &ia->ia_ifa;
        int error;

        /* Prepare gateway */
        struct sockaddr_dl_short sdl = {
                .sdl_family = AF_LINK,
                .sdl_len = sizeof(struct sockaddr_dl_short),
                .sdl_type = ifa->ifa_ifp->if_type,
                .sdl_index = ifa->ifa_ifp->if_index,
        };

        struct sockaddr_in6 dst = {
                .sin6_family = AF_INET6,
                .sin6_len = sizeof(struct sockaddr_in6),
                .sin6_addr = ia->ia_dstaddr.sin6_addr,
        };

        struct rt_addrinfo info = {
                .rti_ifa = ifa,
                .rti_ifp = ifa->ifa_ifp,
                .rti_flags = RTF_PINNED | RTF_HOST,
                .rti_info = {
                        [RTAX_DST] = (struct sockaddr *)&dst,
                        [RTAX_GATEWAY] = (struct sockaddr *)&sdl,
                },
        };
        /* Don't set additional per-gw filters on removal */

        NET_EPOCH_ENTER(et);
        error = rib_handle_ifaddr_info(ifa->ifa_ifp->if_fib, cmd, &info);
        NET_EPOCH_EXIT(et);

        return (error);
}

static bool
ifa_is_p2p(struct in6_ifaddr *ia)
{
        int plen;

        plen = in6_mask2len(&ia->ia_prefixmask.sin6_addr, NULL); /* XXX */

        if ((plen == 128) && (ia->ia_dstaddr.sin6_family == AF_INET6) &&
            !IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &ia->ia_dstaddr.sin6_addr))
                return (true);

        return (false);
}

int
in6_addifaddr(struct ifnet *ifp, struct in6_aliasreq *ifra, struct in6_ifaddr *ia)
{
        struct nd_prefixctl pr0;
        struct nd_prefix *pr;
        int carp_attached = 0;
        int error;

        /*
         * Check if bridge wants to allow adding addrs to member interfaces.
         */
        if (ifp->if_bridge != NULL && ifp->if_type != IFT_GIF &&
            bridge_member_ifaddrs_p != NULL) {
                if (bridge_member_ifaddrs_p()) {
                        if_printf(ifp, "WARNING: Assigning an IP address to "
                            "an interface which is also a bridge member is "
                            "deprecated and will be unsupported in a future "
                            "release.\n");
                } else {
                        error = EINVAL;
                        goto out;
                }
        }

        /*
         * first, make or update the interface address structure,
         * and link it to the list.
         */
        if ((error = in6_update_ifa(ifp, ifra, ia, 0)) != 0)
                goto out;
        if (ia != NULL) {
                if (ia->ia_ifa.ifa_carp)
                        (*carp_detach_p)(&ia->ia_ifa, true);
                ifa_free(&ia->ia_ifa);
        }
        if ((ia = in6ifa_ifpwithaddr(ifp, &ifra->ifra_addr.sin6_addr)) == NULL) {
                /*
                 * this can happen when the user specify the 0 valid
                 * lifetime.
                 */
                return (0);
        }

        if (ifra->ifra_vhid > 0) {
                if (carp_attach_p != NULL)
                        error = (*carp_attach_p)(&ia->ia_ifa,
                            ifra->ifra_vhid);
                else
                        error = EPROTONOSUPPORT;
                if (error)
                        goto out;
                else
                        carp_attached = 1;
        }

        /*
         * then, make the prefix on-link on the interface.
         * XXX: we'd rather create the prefix before the address, but
         * we need at least one address to install the corresponding
         * interface route, so we configure the address first.
         */

        /*
         * convert mask to prefix length (prefixmask has already
         * been validated in in6_update_ifa().
         */
        bzero(&pr0, sizeof(pr0));
        pr0.ndpr_ifp = ifp;
        pr0.ndpr_plen = ia->ia_plen =
            in6_mask2len(&ifra->ifra_prefixmask.sin6_addr, NULL);
        if (pr0.ndpr_plen == 128) {
                /* we don't need to install a host route. */
                goto aifaddr_out;
        }
        pr0.ndpr_prefix = ifra->ifra_addr;
        /* apply the mask for safety. */
        IN6_MASK_ADDR(&pr0.ndpr_prefix.sin6_addr,
            &ifra->ifra_prefixmask.sin6_addr);

        /*
         * XXX: since we don't have an API to set prefix (not address)
         * lifetimes, we just use the same lifetimes as addresses.
         * The (temporarily) installed lifetimes can be overridden by
         * later advertised RAs (when accept_rtadv is non 0), which is
         * an intended behavior.
         */
        pr0.ndpr_raf_onlink = 1; /* should be configurable? */
        pr0.ndpr_raf_auto =
            ((ifra->ifra_flags & IN6_IFF_AUTOCONF) != 0);
        pr0.ndpr_vltime = ifra->ifra_lifetime.ia6t_vltime;
        pr0.ndpr_pltime = ifra->ifra_lifetime.ia6t_pltime;

        /* add the prefix if not yet. */
        if ((pr = nd6_prefix_lookup(&pr0)) == NULL) {
                /*
                 * nd6_prelist_add will install the corresponding
                 * interface route.
                 */
                if ((error = nd6_prelist_add(&pr0, NULL, &pr)) != 0) {
                        if (carp_attached)
                                (*carp_detach_p)(&ia->ia_ifa, false);
                        goto out;
                }
        } else if (pr->ndpr_raf_onlink) {
                time_t expiry;

                /*
                 * If the prefix already exists, update lifetimes, but avoid
                 * shortening them.
                 */
                ND6_WLOCK();
                expiry = in6_expire_time(pr0.ndpr_pltime);
                if (pr->ndpr_preferred != 0 &&
                    (pr->ndpr_preferred < expiry || expiry == 0)) {
                        pr->ndpr_pltime = pr0.ndpr_pltime;
                        pr->ndpr_preferred = expiry;
                }
                expiry = in6_expire_time(pr0.ndpr_vltime);
                if (pr->ndpr_expire != 0 &&
                    (pr->ndpr_expire < expiry || expiry == 0)) {
                        pr->ndpr_vltime = pr0.ndpr_vltime;
                        pr->ndpr_expire = expiry;
                }
                pr->ndpr_lastupdate = time_uptime;
                ND6_WUNLOCK();
        }

        /* relate the address to the prefix */
        if (ia->ia6_ndpr == NULL) {
                ia->ia6_ndpr = pr;
                pr->ndpr_addrcnt++;

                /*
                 * If this is the first autoconf address from the
                 * prefix, create a temporary address as well
                 * (when required).
                 */
                if ((ia->ia6_flags & IN6_IFF_AUTOCONF) &&
                    V_ip6_use_tempaddr && pr->ndpr_addrcnt == 1) {
                        int e;
                        if ((e = in6_tmpifadd(ia, 1, 0)) != 0) {
                                log(LOG_NOTICE, "in6_control: failed "
                                    "to create a temporary address, "
                                    "errno=%d\n", e);
                        }
                }
        }
        nd6_prefix_rele(pr);

        /*
         * this might affect the status of autoconfigured addresses,
         * that is, this address might make other addresses detached.
         */
        pfxlist_onlink_check();

aifaddr_out:
        /*
         * Try to clear the flag when a new IPv6 address is added
         * onto an IFDISABLED interface and it succeeds.
         */
        if (ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED) {
                struct in6_ndireq nd;

                memset(&nd, 0, sizeof(nd));
                nd.ndi.flags = ifp->if_inet6->nd_flags;
                nd.ndi.flags &= ~ND6_IFF_IFDISABLED;
                if (nd6_ioctl(SIOCSIFINFO_FLAGS, (caddr_t)&nd, ifp) < 0)
                        log(LOG_NOTICE, "SIOCAIFADDR_IN6: "
                            "SIOCSIFINFO_FLAGS for -ifdisabled "
                            "failed.");
                /*
                 * Ignore failure of clearing the flag intentionally.
                 * The failure means address duplication was detected.
                 */
        }
        error = 0;

out:
        if (ia != NULL)
                ifa_free(&ia->ia_ifa);
        return (error);
}

void
in6_purgeaddr(struct ifaddr *ifa)
{
        struct ifnet *ifp = ifa->ifa_ifp;
        struct in6_ifaddr *ia = (struct in6_ifaddr *) ifa;
        struct in6_multi_mship *imm;
        int error;

        if (ifa->ifa_carp)
                (*carp_detach_p)(ifa, false);

        /*
         * Remove the loopback route to the interface address.
         * The check for the current setting of "nd6_useloopback"
         * is not needed.
         */
        if (ia->ia_flags & IFA_RTSELF) {
                error = ifa_del_loopback_route((struct ifaddr *)ia,
                    (struct sockaddr *)&ia->ia_addr);
                if (error == 0)
                        ia->ia_flags &= ~IFA_RTSELF;
        }

        /* make sure there are no queued ND6 */
        nd6_queue_stop(ifa);

        /* stop DAD processing */
        nd6_dad_stop(ifa);

        /* Leave multicast groups. */
        while ((imm = LIST_FIRST(&ia->ia6_memberships)) != NULL) {
                LIST_REMOVE(imm, i6mm_chain);
                if (imm->i6mm_maddr != NULL)
                        in6_leavegroup(imm->i6mm_maddr, NULL);
                free(imm, M_IP6MADDR);
        }
        /* Check if we need to remove p2p route */
        if ((ia->ia_flags & IFA_ROUTE) && ifa_is_p2p(ia)) {
                error = in6_handle_dstaddr_rtrequest(RTM_DELETE, ia);
                if (error != 0)
                        log(LOG_INFO, "%s: err=%d, destination address delete "
                            "failed\n", __func__, error);
                ia->ia_flags &= ~IFA_ROUTE;
        }

        in6_newaddrmsg(ia, RTM_DELETE);
        in6_unlink_ifa(ia, ifp);
}

/*
 * Removes @ia from the corresponding interfaces and unlinks corresponding
 *  prefix if no addresses are using it anymore.
 */
void
in6_purgeifaddr(struct in6_ifaddr *ia)
{
        struct nd_prefix *pr;

        /*
         * If the address being deleted is the only one that owns
         * the corresponding prefix, expire the prefix as well.
         * XXX: theoretically, we don't have to worry about such
         * relationship, since we separate the address management
         * and the prefix management.  We do this, however, to provide
         * as much backward compatibility as possible in terms of
         * the ioctl operation.
         * Note that in6_purgeaddr() will decrement ndpr_addrcnt.
         */
        pr = ia->ia6_ndpr;
        in6_purgeaddr(&ia->ia_ifa);
        if (pr != NULL && pr->ndpr_addrcnt == 0) {
                ND6_WLOCK();
                nd6_prefix_unlink(pr, NULL);
                ND6_WUNLOCK();
                nd6_prefix_del(pr);
        }
}


static void
in6_unlink_ifa(struct in6_ifaddr *ia, struct ifnet *ifp)
{
        char ip6buf[INET6_ADDRSTRLEN];
        int remove_lle;

        IF_ADDR_WLOCK(ifp);
        CK_STAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifaddr, ifa_link);
        IF_ADDR_WUNLOCK(ifp);
        ifa_free(&ia->ia_ifa);                  /* if_addrhead */

        /*
         * Defer the release of what might be the last reference to the
         * in6_ifaddr so that it can't be freed before the remainder of the
         * cleanup.
         */
        IN6_IFADDR_WLOCK();
        CK_STAILQ_REMOVE(&V_in6_ifaddrhead, ia, in6_ifaddr, ia_link);
        CK_LIST_REMOVE(ia, ia6_hash);
        IN6_IFADDR_WUNLOCK();

        /*
         * Release the reference to the base prefix.  There should be a
         * positive reference.
         */
        remove_lle = 0;
        if (ia->ia6_ndpr != NULL) {
                ia->ia6_ndpr->ndpr_addrcnt--;
                /* Do not delete lles within prefix if refcont != 0 */
                if (ia->ia6_ndpr->ndpr_addrcnt == 0)
                        remove_lle = 1;
                ia->ia6_ndpr = NULL;
        } else if (ia->ia_plen < 128) {
                nd6log((LOG_NOTICE,
                    "in6_unlink_ifa: autoconf'ed address "
                    "%s has no prefix\n", ip6_sprintf(ip6buf, IA6_IN6(ia))));
        }

        nd6_rem_ifa_lle(ia, remove_lle);

        /*
         * Also, if the address being removed is autoconf'ed, call
         * pfxlist_onlink_check() since the release might affect the status of
         * other (detached) addresses.
         */
        if ((ia->ia6_flags & IN6_IFF_AUTOCONF)) {
                pfxlist_onlink_check();
        }
        ifa_free(&ia->ia_ifa);                  /* in6_ifaddrhead */
}

/*
 * Notifies other subsystems about address change/arrival:
 * 1) Notifies device handler on the first IPv6 address assignment
 * 2) Handle routing table changes for P2P links and route
 * 3) Handle routing table changes for address host route
 */
static int
in6_notify_ifa(struct ifnet *ifp, struct in6_ifaddr *ia,
    struct in6_aliasreq *ifra, int hostIsNew)
{
        int     error = 0, ifacount = 0;
        struct ifaddr *ifa;
        struct sockaddr_in6 *pdst;
        char ip6buf[INET6_ADDRSTRLEN];

        /*
         * Give the interface a chance to initialize
         * if this is its first address,
         */
        if (hostIsNew != 0) {
                struct epoch_tracker et;

                NET_EPOCH_ENTER(et);
                CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
                        if (ifa->ifa_addr->sa_family != AF_INET6)
                                continue;
                        ifacount++;
                }
                NET_EPOCH_EXIT(et);
        }

        if (ifacount <= 1 && ifp->if_ioctl) {
                error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia);
                if (error)
                        goto done;
        }

        /*
         * If a new destination address is specified, scrub the old one and
         * install the new destination.  Note that the interface must be
         * p2p or loopback.
         */
        pdst = &ifra->ifra_dstaddr;
        if (pdst->sin6_family == AF_INET6 &&
            !IN6_ARE_ADDR_EQUAL(&pdst->sin6_addr, &ia->ia_dstaddr.sin6_addr)) {
                if ((ia->ia_flags & IFA_ROUTE) != 0 &&
                    (in6_handle_dstaddr_rtrequest(RTM_DELETE, ia) != 0)) {
                        nd6log((LOG_ERR, "in6_update_ifa_internal: failed to "
                            "remove a route to the old destination: %s\n",
                            ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
                        /* proceed anyway... */
                } else
                        ia->ia_flags &= ~IFA_ROUTE;
                ia->ia_dstaddr = *pdst;
        }

        /*
         * If a new destination address is specified for a point-to-point
         * interface, install a route to the destination as an interface
         * direct route.
         * XXX: the logic below rejects assigning multiple addresses on a p2p
         * interface that share the same destination.
         */
        if (!(ia->ia_flags & IFA_ROUTE) && ifa_is_p2p(ia)) {
                error = in6_handle_dstaddr_rtrequest(RTM_ADD, ia);
                if (error)
                        goto done;
                ia->ia_flags |= IFA_ROUTE;
        }

        /*
         * add a loopback route to self if not exists
         */
        if (!(ia->ia_flags & IFA_RTSELF) && V_nd6_useloopback) {
                error = ifa_add_loopback_route((struct ifaddr *)ia,
                    (struct sockaddr *)&ia->ia_addr);
                if (error == 0)
                        ia->ia_flags |= IFA_RTSELF;
        }
done:
        WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
            "Invoking IPv6 network device address event may sleep");

        ifa_ref(&ia->ia_ifa);
        EVENTHANDLER_INVOKE(ifaddr_event_ext, ifp, &ia->ia_ifa,
            IFADDR_EVENT_ADD);
        ifa_free(&ia->ia_ifa);

        return (error);
}

/*
 * Find an IPv6 interface link-local address specific to an interface.
 * ifaddr is returned referenced.
 */
struct in6_ifaddr *
in6ifa_ifpforlinklocal(struct ifnet *ifp, int ignoreflags)
{
        struct ifaddr *ifa;

        NET_EPOCH_ASSERT();

        CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
                if (ifa->ifa_addr->sa_family != AF_INET6)
                        continue;
                if (IN6_IS_ADDR_LINKLOCAL(IFA_IN6(ifa))) {
                        if ((((struct in6_ifaddr *)ifa)->ia6_flags &
                            ignoreflags) != 0)
                                continue;
                        ifa_ref(ifa);
                        break;
                }
        }

        return ((struct in6_ifaddr *)ifa);
}

/*
 * find the interface address corresponding to a given IPv6 address.
 * ifaddr is returned referenced if @referenced flag is set.
 */
struct in6_ifaddr *
in6ifa_ifwithaddr(const struct in6_addr *addr, uint32_t zoneid, bool referenced)
{
        struct rm_priotracker in6_ifa_tracker;
        struct in6_ifaddr *ia;

        IN6_IFADDR_RLOCK(&in6_ifa_tracker);
        CK_LIST_FOREACH(ia, IN6ADDR_HASH(addr), ia6_hash) {
                if (IN6_ARE_ADDR_EQUAL(IA6_IN6(ia), addr)) {
                        if (zoneid != 0 &&
                            zoneid != ia->ia_addr.sin6_scope_id)
                                continue;
                        if (referenced)
                                ifa_ref(&ia->ia_ifa);
                        break;
                }
        }
        IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
        return (ia);
}

/*
 * find the internet address corresponding to a given interface and address.
 * ifaddr is returned referenced.
 */
struct in6_ifaddr *
in6ifa_ifpwithaddr(struct ifnet *ifp, const struct in6_addr *addr)
{
        struct epoch_tracker et;
        struct ifaddr *ifa;

        NET_EPOCH_ENTER(et);
        CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
                if (ifa->ifa_addr->sa_family != AF_INET6)
                        continue;
                if (IN6_ARE_ADDR_EQUAL(addr, IFA_IN6(ifa))) {
                        ifa_ref(ifa);
                        break;
                }
        }
        NET_EPOCH_EXIT(et);

        return ((struct in6_ifaddr *)ifa);
}

/*
 * Find a link-local scoped address on ifp and return it if any.
 */
struct in6_ifaddr *
in6ifa_llaonifp(struct ifnet *ifp)
{
        struct epoch_tracker et;
        struct sockaddr_in6 *sin6;
        struct ifaddr *ifa;

        if (ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED)
                return (NULL);
        NET_EPOCH_ENTER(et);
        CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
                if (ifa->ifa_addr->sa_family != AF_INET6)
                        continue;
                sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
                if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr) ||
                    IN6_IS_ADDR_MC_INTFACELOCAL(&sin6->sin6_addr) ||
                    IN6_IS_ADDR_MC_NODELOCAL(&sin6->sin6_addr))
                        break;
        }
        NET_EPOCH_EXIT(et);

        return ((struct in6_ifaddr *)ifa);
}

/*
 * Convert IP6 address to printable (loggable) representation. Caller
 * has to make sure that ip6buf is at least INET6_ADDRSTRLEN long.
 */
static char digits[] = "0123456789abcdef";
char *
ip6_sprintf(char *ip6buf, const struct in6_addr *addr)
{
        int i, cnt = 0, maxcnt = 0, idx = 0, index = 0;
        char *cp;
        const u_int16_t *a = (const u_int16_t *)addr;
        const u_int8_t *d;
        int dcolon = 0, zero = 0;

        cp = ip6buf;

        for (i = 0; i < 8; i++) {
                if (*(a + i) == 0) {
                        cnt++;
                        if (cnt == 1)
                                idx = i;
                }
                else if (maxcnt < cnt) {
                        maxcnt = cnt;
                        index = idx;
                        cnt = 0;
                }
        }
        if (maxcnt < cnt) {
                maxcnt = cnt;
                index = idx;
        }

        for (i = 0; i < 8; i++) {
                if (dcolon == 1) {
                        if (*a == 0) {
                                if (i == 7)
                                        *cp++ = ':';
                                a++;
                                continue;
                        } else
                                dcolon = 2;
                }
                if (*a == 0) {
                        if (dcolon == 0 && *(a + 1) == 0 && i == index) {
                                if (i == 0)
                                        *cp++ = ':';
                                *cp++ = ':';
                                dcolon = 1;
                        } else {
                                *cp++ = '0';
                                *cp++ = ':';
                        }
                        a++;
                        continue;
                }
                d = (const u_char *)a;
                /* Try to eliminate leading zeros in printout like in :0001. */
                zero = 1;
                *cp = digits[*d >> 4];
                if (*cp != '0') {
                        zero = 0;
                        cp++;
                }
                *cp = digits[*d++ & 0xf];
                if (zero == 0 || (*cp != '0')) {
                        zero = 0;
                        cp++;
                }
                *cp = digits[*d >> 4];
                if (zero == 0 || (*cp != '0')) {
                        zero = 0;
                        cp++;
                }
                *cp++ = digits[*d & 0xf];
                *cp++ = ':';
                a++;
        }
        *--cp = '\0';
        return (ip6buf);
}

int
in6_localaddr(struct in6_addr *in6)
{
        struct rm_priotracker in6_ifa_tracker;
        struct in6_ifaddr *ia;

        if (IN6_IS_ADDR_LOOPBACK(in6) || IN6_IS_ADDR_LINKLOCAL(in6))
                return 1;

        IN6_IFADDR_RLOCK(&in6_ifa_tracker);
        CK_STAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) {
                if (IN6_ARE_MASKED_ADDR_EQUAL(in6, &ia->ia_addr.sin6_addr,
                    &ia->ia_prefixmask.sin6_addr)) {
                        IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
                        return 1;
                }
        }
        IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);

        return (0);
}

/*
 * Return 1 if an internet address is for the local host and configured
 * on one of its interfaces.
 */
int
in6_localip(struct in6_addr *in6)
{
        struct rm_priotracker in6_ifa_tracker;
        struct in6_ifaddr *ia;

        IN6_IFADDR_RLOCK(&in6_ifa_tracker);
        CK_LIST_FOREACH(ia, IN6ADDR_HASH(in6), ia6_hash) {
                if (IN6_ARE_ADDR_EQUAL(in6, &ia->ia_addr.sin6_addr)) {
                        IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
                        return (1);
                }
        }
        IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
        return (0);
}

/*
 * Like in6_localip(), but FIB-aware and carp(4)-aware.
 */
bool
in6_localip_fib(struct in6_addr *in6, uint16_t fib)
{
        struct rm_priotracker in6_ifa_tracker;
        struct in6_ifaddr *ia;

        IN6_IFADDR_RLOCK(&in6_ifa_tracker);
        CK_LIST_FOREACH(ia, IN6ADDR_HASH(in6), ia6_hash) {
                if (IN6_ARE_ADDR_EQUAL(in6, &ia->ia_addr.sin6_addr) &&
                    (ia->ia_ifa.ifa_carp == NULL ||
                    carp_master_p(&ia->ia_ifa)) &&
                    ia->ia_ifa.ifa_ifp->if_fib == fib) {
                        IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
                        return (true);
                }
        }
        IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
        return (false);
}

/*
 * Return 1 if an internet address is configured on an interface.
 */
int
in6_ifhasaddr(struct ifnet *ifp, struct in6_addr *addr)
{
        struct in6_addr in6;
        struct ifaddr *ifa;
        struct in6_ifaddr *ia6;

        NET_EPOCH_ASSERT();

        in6 = *addr;
        if (in6_clearscope(&in6))
                return (0);
        in6_setscope(&in6, ifp, NULL);

        CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
                if (ifa->ifa_addr->sa_family != AF_INET6)
                        continue;
                ia6 = (struct in6_ifaddr *)ifa;
                if (IN6_ARE_ADDR_EQUAL(&ia6->ia_addr.sin6_addr, &in6))
                        return (1);
        }

        return (0);
}

int
in6_is_addr_deprecated(struct sockaddr_in6 *sa6)
{
        struct rm_priotracker in6_ifa_tracker;
        struct in6_ifaddr *ia;

        IN6_IFADDR_RLOCK(&in6_ifa_tracker);
        CK_LIST_FOREACH(ia, IN6ADDR_HASH(&sa6->sin6_addr), ia6_hash) {
                if (IN6_ARE_ADDR_EQUAL(IA6_IN6(ia), &sa6->sin6_addr)) {
                        if (ia->ia6_flags & IN6_IFF_DEPRECATED) {
                                IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
                                return (1); /* true */
                        }
                        break;
                }
        }
        IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);

        return (0);             /* false */
}

/*
 * return length of part which dst and src are equal
 * hard coding...
 */
int
in6_matchlen(struct in6_addr *src, struct in6_addr *dst)
{
        int match = 0;
        u_char *s = (u_char *)src, *d = (u_char *)dst;
        u_char *lim = s + 16, r;

        while (s < lim)
                if ((r = (*d++ ^ *s++)) != 0) {
                        while (r < 128) {
                                match++;
                                r <<= 1;
                        }
                        break;
                } else
                        match += 8;
        return match;
}

/* XXX: to be scope conscious */
int
in6_are_prefix_equal(struct in6_addr *p1, struct in6_addr *p2, int len)
{
        int bytelen, bitlen;

        /* sanity check */
        if (0 > len || len > 128) {
                log(LOG_ERR, "in6_are_prefix_equal: invalid prefix length(%d)\n",
                    len);
                return (0);
        }

        bytelen = len / 8;
        bitlen = len % 8;

        if (bcmp(&p1->s6_addr, &p2->s6_addr, bytelen))
                return (0);
        if (bitlen != 0 &&
            p1->s6_addr[bytelen] >> (8 - bitlen) !=
            p2->s6_addr[bytelen] >> (8 - bitlen))
                return (0);

        return (1);
}

void
in6_prefixlen2mask(struct in6_addr *maskp, int len)
{
        u_char maskarray[8] = {0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff};
        int bytelen, bitlen, i;

        /* sanity check */
        if (0 > len || len > 128) {
                log(LOG_ERR, "in6_prefixlen2mask: invalid prefix length(%d)\n",
                    len);
                return;
        }

        bzero(maskp, sizeof(*maskp));
        bytelen = len / 8;
        bitlen = len % 8;
        for (i = 0; i < bytelen; i++)
                maskp->s6_addr[i] = 0xff;
        if (bitlen)
                maskp->s6_addr[bytelen] = maskarray[bitlen - 1];
}

/*
 * return the best address out of the same scope. if no address was
 * found, return the first valid address from designated IF.
 */
struct in6_ifaddr *
in6_ifawithifp(struct ifnet *ifp, struct in6_addr *dst)
{
        int dst_scope = in6_addrscope(dst), blen = -1, tlen;
        struct ifaddr *ifa;
        struct in6_ifaddr *besta = NULL;
        struct in6_ifaddr *dep[2];      /* last-resort: deprecated */

        NET_EPOCH_ASSERT();

        dep[0] = dep[1] = NULL;

        /*
         * We first look for addresses in the same scope.
         * If there is one, return it.
         * If two or more, return one which matches the dst longest.
         * If none, return one of global addresses assigned other ifs.
         */
        CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
                if (ifa->ifa_addr->sa_family != AF_INET6)
                        continue;
                if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)
                        continue; /* XXX: is there any case to allow anycast? */
                if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY)
                        continue; /* don't use this interface */
                if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DETACHED)
                        continue;
                if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DEPRECATED) {
                        if (V_ip6_use_deprecated)
                                dep[0] = (struct in6_ifaddr *)ifa;
                        continue;
                }

                if (dst_scope == in6_addrscope(IFA_IN6(ifa))) {
                        /*
                         * call in6_matchlen() as few as possible
                         */
                        if (besta) {
                                if (blen == -1)
                                        blen = in6_matchlen(&besta->ia_addr.sin6_addr, dst);
                                tlen = in6_matchlen(IFA_IN6(ifa), dst);
                                if (tlen > blen) {
                                        blen = tlen;
                                        besta = (struct in6_ifaddr *)ifa;
                                }
                        } else
                                besta = (struct in6_ifaddr *)ifa;
                }
        }
        if (besta)
                return (besta);

        CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
                if (ifa->ifa_addr->sa_family != AF_INET6)
                        continue;
                if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)
                        continue; /* XXX: is there any case to allow anycast? */
                if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY)
                        continue; /* don't use this interface */
                if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DETACHED)
                        continue;
                if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DEPRECATED) {
                        if (V_ip6_use_deprecated)
                                dep[1] = (struct in6_ifaddr *)ifa;
                        continue;
                }

                return (struct in6_ifaddr *)ifa;
        }

        /* use the last-resort values, that are, deprecated addresses */
        if (dep[0])
                return dep[0];
        if (dep[1])
                return dep[1];

        return NULL;
}

/*
 * perform DAD when interface becomes IFF_UP.
 */
void
in6_if_up(struct ifnet *ifp)
{
        struct epoch_tracker et;
        struct ifaddr *ifa;
        struct in6_ifaddr *ia;

        NET_EPOCH_ENTER(et);
        CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
                if (ifa->ifa_addr->sa_family != AF_INET6)
                        continue;
                ia = (struct in6_ifaddr *)ifa;
                if (ia->ia6_flags & IN6_IFF_TENTATIVE) {
                        /*
                         * The TENTATIVE flag was likely set by hand
                         * beforehand, implicitly indicating the need for DAD.
                         * We may be able to skip the random delay in this
                         * case, but we impose delays just in case.
                         */
                        nd6_dad_start(ifa,
                            arc4random() % (MAX_RTR_SOLICITATION_DELAY * hz));
                }
        }
        NET_EPOCH_EXIT(et);

        /*
         * special cases, like 6to4, are handled in in6_ifattach
         */
        in6_ifattach(ifp, NULL);
}

static void
in6_ifevent(void *arg __unused, struct ifnet *ifp, int event)
{
        if (event == IFNET_EVENT_UP)
                in6_if_up(ifp);
}

static void
in6_init(void *arg __unused)
{
        EVENTHANDLER_REGISTER(ifnet_event, in6_ifevent, NULL, EVENTHANDLER_PRI_ANY);
}
SYSINIT(in6_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, in6_init, NULL);

int
in6if_do_dad(struct ifnet *ifp)
{

        if ((ifp->if_flags & IFF_LOOPBACK) != 0)
                return (0);
        if ((ifp->if_flags & IFF_MULTICAST) == 0)
                return (0);
        if ((ifp->if_inet6->nd_flags &
            (ND6_IFF_IFDISABLED | ND6_IFF_NO_DAD)) != 0)
                return (0);
        return (1);
}

/*
 * Provide the length of interface identifiers to be used for the link attached
 * to the given interface.  The length should be defined in "IPv6 over
 * xxx-link" document.  Note that address architecture might also define
 * the length for a particular set of address prefixes, regardless of the
 * link type.  As clarified in rfc2462bis, those two definitions should be
 * consistent, and those really are as of August 2004.
 */
int
in6_if2idlen(struct ifnet *ifp)
{
        switch (ifp->if_type) {
        case IFT_ETHER:         /* RFC2464 */
        case IFT_PROPVIRTUAL:   /* XXX: no RFC. treat it as ether */
        case IFT_L2VLAN:        /* ditto */
        case IFT_BRIDGE:        /* bridge(4) only does Ethernet-like links */
        case IFT_INFINIBAND:
                return (64);
        case IFT_PPP:           /* RFC2472 */
                return (64);
        case IFT_FRELAY:        /* RFC2590 */
                return (64);
        case IFT_IEEE1394:      /* RFC3146 */
                return (64);
        case IFT_GIF:
                return (64);    /* draft-ietf-v6ops-mech-v2-07 */
        case IFT_LOOP:
                return (64);    /* XXX: is this really correct? */
        default:
                /*
                 * Unknown link type:
                 * It might be controversial to use the today's common constant
                 * of 64 for these cases unconditionally.  For full compliance,
                 * we should return an error in this case.  On the other hand,
                 * if we simply miss the standard for the link type or a new
                 * standard is defined for a new link type, the IFID length
                 * is very likely to be the common constant.  As a compromise,
                 * we always use the constant, but make an explicit notice
                 * indicating the "unknown" case.
                 */
                printf("in6_if2idlen: unknown link type (%d)\n", ifp->if_type);
                return (64);
        }
}

struct in6_llentry {
        struct llentry          base;
};

#define IN6_LLTBL_DEFAULT_HSIZE 32
#define IN6_LLTBL_HASH(k, h) \
        (((((((k >> 8) ^ k) >> 8) ^ k) >> 8) ^ k) & ((h) - 1))

/*
 * Do actual deallocation of @lle.
 */
static void
in6_lltable_destroy_lle_unlocked(epoch_context_t ctx)
{
        struct llentry *lle;

        lle = __containerof(ctx, struct llentry, lle_epoch_ctx);
        LLE_LOCK_DESTROY(lle);
        LLE_REQ_DESTROY(lle);
        free(lle, M_LLTABLE);
}

/*
 * Called by LLE_FREE_LOCKED when number of references
 * drops to zero.
 */
static void
in6_lltable_destroy_lle(struct llentry *lle)
{

        LLE_WUNLOCK(lle);
        NET_EPOCH_CALL(in6_lltable_destroy_lle_unlocked, &lle->lle_epoch_ctx);
}

static struct llentry *
in6_lltable_new(const struct in6_addr *addr6, u_int flags)
{
        struct in6_llentry *lle;

        lle = malloc(sizeof(struct in6_llentry), M_LLTABLE, M_NOWAIT | M_ZERO);
        if (lle == NULL)                /* NB: caller generates msg */
                return NULL;

        lle->base.r_l3addr.addr6 = *addr6;
        lle->base.lle_refcnt = 1;
        lle->base.lle_free = in6_lltable_destroy_lle;
        LLE_LOCK_INIT(&lle->base);
        LLE_REQ_INIT(&lle->base);
        callout_init(&lle->base.lle_timer, 1);

        return (&lle->base);
}

static int
in6_lltable_match_prefix(const struct sockaddr *saddr,
    const struct sockaddr *smask, u_int flags, struct llentry *lle)
{
        const struct in6_addr *addr, *mask, *lle_addr;

        addr = &((const struct sockaddr_in6 *)saddr)->sin6_addr;
        mask = &((const struct sockaddr_in6 *)smask)->sin6_addr;
        lle_addr = &lle->r_l3addr.addr6;

        if (IN6_ARE_MASKED_ADDR_EQUAL(lle_addr, addr, mask) == 0)
                return (0);

        if (lle->la_flags & LLE_IFADDR) {
                /*
                 * Delete LLE_IFADDR records IFF address & flag matches.
                 * Note that addr is the interface address within prefix
                 * being matched.
                 */
                if (IN6_ARE_ADDR_EQUAL(addr, lle_addr) &&
                    (flags & LLE_STATIC) != 0)
                        return (1);
                return (0);
        }

        /* flags & LLE_STATIC means deleting both dynamic and static entries */
        if ((flags & LLE_STATIC) || !(lle->la_flags & LLE_STATIC))
                return (1);

        return (0);
}

static void
in6_lltable_free_entry(struct lltable *llt, struct llentry *lle)
{

        LLE_WLOCK_ASSERT(lle);
        KASSERT(llt != NULL, ("lltable is NULL"));

        /* Unlink entry from table */
        if ((lle->la_flags & LLE_LINKED) != 0) {
                LLTABLE_LOCK_ASSERT(llt);
                lltable_unlink_entry(llt, lle);
        }

        llentry_free(lle);
}

static int
in6_lltable_rtcheck(struct ifnet *ifp,
                    u_int flags,
                    const struct sockaddr *l3addr)
{
        const struct sockaddr_in6 *sin6;
        struct nhop_object *nh;
        struct in6_addr dst;
        uint32_t scopeid;
        char ip6buf[INET6_ADDRSTRLEN];
        int fibnum;

        NET_EPOCH_ASSERT();
        KASSERT(l3addr->sa_family == AF_INET6,
            ("sin_family %d", l3addr->sa_family));

        sin6 = (const struct sockaddr_in6 *)l3addr;
        in6_splitscope(&sin6->sin6_addr, &dst, &scopeid);
        fibnum = V_rt_add_addr_allfibs ? RT_DEFAULT_FIB : ifp->if_fib;
        nh = fib6_lookup(fibnum, &dst, scopeid, NHR_NONE, 0);
        if (nh && ((nh->nh_flags & NHF_GATEWAY) || nh->nh_ifp != ifp)) {
                struct ifaddr *ifa;
                /*
                 * Create an ND6 cache for an IPv6 neighbor
                 * that is not covered by our own prefix.
                 */
                ifa = ifaof_ifpforaddr(l3addr, ifp);
                if (ifa != NULL) {
                        return 0;
                }
                log(LOG_INFO, "IPv6 address: \"%s\" is not on the network\n",
                    ip6_sprintf(ip6buf, &sin6->sin6_addr));
                return EINVAL;
        }
        return 0;
}

static inline uint32_t
in6_lltable_hash_dst(const struct in6_addr *dst, uint32_t hsize)
{

        return (IN6_LLTBL_HASH(dst->s6_addr32[3], hsize));
}

static uint32_t
in6_lltable_hash(const struct llentry *lle, uint32_t hsize)
{

        return (in6_lltable_hash_dst(&lle->r_l3addr.addr6, hsize));
}

static void
in6_lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa)
{
        struct sockaddr_in6 *sin6;

        sin6 = (struct sockaddr_in6 *)sa;
        bzero(sin6, sizeof(*sin6));
        sin6->sin6_family = AF_INET6;
        sin6->sin6_len = sizeof(*sin6);
        sin6->sin6_addr = lle->r_l3addr.addr6;
}

static inline struct llentry *
in6_lltable_find_dst(struct lltable *llt, const struct in6_addr *dst)
{
        struct llentry *lle;
        struct llentries *lleh;
        u_int hashidx;

        hashidx = in6_lltable_hash_dst(dst, llt->llt_hsize);
        lleh = &llt->lle_head[hashidx];
        CK_LIST_FOREACH(lle, lleh, lle_next) {
                if (lle->la_flags & LLE_DELETED)
                        continue;
                if (IN6_ARE_ADDR_EQUAL(&lle->r_l3addr.addr6, dst))
                        break;
        }

        return (lle);
}

static void
in6_lltable_delete_entry(struct lltable *llt, struct llentry *lle)
{

        lle->la_flags |= LLE_DELETED;

        /* Leave the solicited multicast group. */
        if ((lle->la_flags & LLE_PUB) != 0)
                in6_leave_proxy_ndp_mc(llt->llt_ifp, &lle->r_l3addr.addr6);
        EVENTHANDLER_INVOKE(lle_event, lle, LLENTRY_DELETED);
#ifdef DIAGNOSTIC
        log(LOG_INFO, "ifaddr cache = %p is deleted\n", lle);
#endif
        llentry_free(lle);
}

static struct llentry *
in6_lltable_alloc(struct lltable *llt, u_int flags,
        const struct sockaddr *l3addr)
{
        const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)l3addr;
        struct ifnet *ifp = llt->llt_ifp;
        struct llentry *lle;
        char linkhdr[LLE_MAX_LINKHDR];
        size_t linkhdrsize;
        int lladdr_off;

        KASSERT(l3addr->sa_family == AF_INET6,
            ("sin_family %d", l3addr->sa_family));

        /*
         * A route that covers the given address must have
         * been installed 1st because we are doing a resolution,
         * verify this.
         */
        if (!(flags & LLE_IFADDR) &&
            in6_lltable_rtcheck(ifp, flags, l3addr) != 0)
                return (NULL);

        lle = in6_lltable_new(&sin6->sin6_addr, flags);
        if (lle == NULL) {
                log(LOG_INFO, "lla_lookup: new lle malloc failed\n");
                return (NULL);
        }
        lle->la_flags = flags;
        if ((flags & LLE_IFADDR) == LLE_IFADDR) {
                linkhdrsize = LLE_MAX_LINKHDR;
                if (lltable_calc_llheader(ifp, AF_INET6, IF_LLADDR(ifp),
                    linkhdr, &linkhdrsize, &lladdr_off) != 0) {
                        in6_lltable_free_entry(llt, lle);
                        return (NULL);
                }
                lltable_set_entry_addr(ifp, lle, linkhdr, linkhdrsize,
                    lladdr_off);
                lle->la_flags |= LLE_STATIC;
        }

        if ((lle->la_flags & LLE_STATIC) != 0)
                lle->ln_state = ND6_LLINFO_REACHABLE;

        return (lle);
}

static struct llentry *
in6_lltable_lookup(struct lltable *llt, u_int flags,
        const struct sockaddr *l3addr)
{
        const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)l3addr;
        int family = flags >> 16;
        struct llentry *lle;

        LLTABLE_RLOCK_ASSERT(llt);
        KASSERT(l3addr->sa_family == AF_INET6,
            ("sin_family %d", l3addr->sa_family));
        KASSERT((flags & (LLE_UNLOCKED | LLE_EXCLUSIVE)) !=
            (LLE_UNLOCKED | LLE_EXCLUSIVE),
            ("wrong lle request flags: %#x", flags));

        lle = in6_lltable_find_dst(llt, &sin6->sin6_addr);

        if (__predict_false(family != AF_INET6))
                lle = llentry_lookup_family(lle, family);

        if (lle == NULL)
                return (NULL);

        if (flags & LLE_UNLOCKED)
                return (lle);

        if (flags & LLE_EXCLUSIVE)
                LLE_WLOCK(lle);
        else
                LLE_RLOCK(lle);

        /*
         * If the lltable lock is not held, the LLE may have been unlinked while
         * we were blocked on the LLE lock.  Check for this case.
         */
        if (__predict_false((lle->la_flags & LLE_LINKED) == 0)) {
                if (flags & LLE_EXCLUSIVE)
                        LLE_WUNLOCK(lle);
                else
                        LLE_RUNLOCK(lle);
                return (NULL);
        }
        return (lle);
}

static int
in6_lltable_dump_entry(struct lltable *llt, struct llentry *lle,
    struct sysctl_req *wr)
{
        struct ifnet *ifp = llt->llt_ifp;
        /* XXX stack use */
        struct {
                struct rt_msghdr        rtm;
                struct sockaddr_in6     sin6;
                /*
                 * ndp.c assumes that sdl is word aligned
                 */
#ifdef __LP64__
                uint32_t                pad;
#endif
                struct sockaddr_dl      sdl;
        } ndpc;
        struct sockaddr_dl *sdl;
        int error;

        bzero(&ndpc, sizeof(ndpc));
        /* skip deleted entries */
        if ((lle->la_flags & LLE_DELETED) == LLE_DELETED)
                return (0);
        /* Skip if jailed and not a valid IP of the prison. */
        lltable_fill_sa_entry(lle, (struct sockaddr *)&ndpc.sin6);
        if (prison_if(wr->td->td_ucred, (struct sockaddr *)&ndpc.sin6) != 0)
                return (0);
        /*
         * produce a msg made of:
         *  struct rt_msghdr;
         *  struct sockaddr_in6 (IPv6)
         *  struct sockaddr_dl;
         */
        ndpc.rtm.rtm_msglen = sizeof(ndpc);
        ndpc.rtm.rtm_version = RTM_VERSION;
        ndpc.rtm.rtm_type = RTM_GET;
        ndpc.rtm.rtm_flags = RTF_UP;
        ndpc.rtm.rtm_addrs = RTA_DST | RTA_GATEWAY;
        sa6_recoverscope(&ndpc.sin6);

        /* publish */
        if (lle->la_flags & LLE_PUB)
                ndpc.rtm.rtm_flags |= RTF_ANNOUNCE;

        sdl = &ndpc.sdl;
        sdl->sdl_family = AF_LINK;
        sdl->sdl_len = sizeof(*sdl);
        sdl->sdl_index = ifp->if_index;
        sdl->sdl_type = ifp->if_type;
        if ((lle->la_flags & LLE_VALID) == LLE_VALID) {
                sdl->sdl_alen = ifp->if_addrlen;
                bcopy(lle->ll_addr, LLADDR(sdl), ifp->if_addrlen);
        } else {
                sdl->sdl_alen = 0;
                bzero(LLADDR(sdl), ifp->if_addrlen);
        }
        if (lle->la_expire != 0)
                ndpc.rtm.rtm_rmx.rmx_expire = lle->la_expire +
                    lle->lle_remtime / hz + time_second - time_uptime;
        ndpc.rtm.rtm_flags |= (RTF_HOST | RTF_LLDATA);
        if (lle->la_flags & LLE_STATIC)
                ndpc.rtm.rtm_flags |= RTF_STATIC;
        if (lle->la_flags & LLE_IFADDR)
                ndpc.rtm.rtm_flags |= RTF_PINNED;
        if (lle->ln_router != 0)
                ndpc.rtm.rtm_flags |= RTF_GATEWAY;
        ndpc.rtm.rtm_rmx.rmx_pksent = lle->la_asked;
        /* Store state in rmx_weight value */
        ndpc.rtm.rtm_rmx.rmx_state = lle->ln_state;
        ndpc.rtm.rtm_index = ifp->if_index;
        error = SYSCTL_OUT(wr, &ndpc, sizeof(ndpc));

        return (error);
}

static void
in6_lltable_post_resolved(struct lltable *llt, struct llentry *lle)
{
        /* Join the solicited multicast group for dst. */
        if ((lle->la_flags & LLE_PUB) == LLE_PUB)
                in6_join_proxy_ndp_mc(llt->llt_ifp, &lle->r_l3addr.addr6);
}

static struct lltable *
in6_lltattach(struct ifnet *ifp)
{
        struct lltable *llt;

        llt = lltable_allocate_htbl(IN6_LLTBL_DEFAULT_HSIZE);
        llt->llt_af = AF_INET6;
        llt->llt_ifp = ifp;

        llt->llt_lookup = in6_lltable_lookup;
        llt->llt_alloc_entry = in6_lltable_alloc;
        llt->llt_delete_entry = in6_lltable_delete_entry;
        llt->llt_dump_entry = in6_lltable_dump_entry;
        llt->llt_hash = in6_lltable_hash;
        llt->llt_fill_sa_entry = in6_lltable_fill_sa_entry;
        llt->llt_free_entry = in6_lltable_free_entry;
        llt->llt_match_prefix = in6_lltable_match_prefix;
        llt->llt_mark_used = llentry_mark_used;
        llt->llt_post_resolved = in6_lltable_post_resolved;
        lltable_link(llt);

        return (llt);
}

struct lltable *
in6_lltable_get(struct ifnet *ifp)
{
        if (ifp->if_inet6 == NULL)
                return (NULL);

        return (ifp->if_inet6->lltable);
}

void
in6_ifarrival(void *arg __unused, struct ifnet *ifp)
{
        struct in6_ifextra *ext;

        /* There are not IPv6-capable interfaces. */
        switch (ifp->if_type) {
        case IFT_PFLOG:
        case IFT_PFSYNC:
                ifp->if_inet6 = NULL;
                return;
        }
        ext = ifp->if_inet6 = malloc(sizeof(*ext), M_IFADDR, M_WAITOK | M_ZERO);
        COUNTER_ARRAY_ALLOC(ext->in6_ifstat,
            sizeof(struct in6_ifstat) / sizeof(uint64_t), M_WAITOK);
        COUNTER_ARRAY_ALLOC(ext->icmp6_ifstat,
            sizeof(struct icmp6_ifstat) / sizeof(uint64_t), M_WAITOK);
        nd6_ifattach(ifp);
        mld_domifattach(ifp);
        scope6_ifattach(ifp);

        ext->lltable = in6_lltattach(ifp);
}
EVENTHANDLER_DEFINE(ifnet_arrival_event, in6_ifarrival, NULL,
    EVENTHANDLER_PRI_ANY);

uint32_t
in6_ifmtu(const struct ifnet *ifp)
{
        const uint32_t
            linkmtu = ifp->if_inet6->nd_linkmtu,
            maxmtu = ifp->if_inet6->nd_maxmtu,
            ifmtu = ifp->if_mtu;

        if (linkmtu > 0 && linkmtu < ifmtu)
                return (linkmtu);
        if (maxmtu > 0 && maxmtu < ifmtu)
                return (maxmtu);
        return (ifmtu);
}

/*
 * Convert sockaddr_in6 to sockaddr_in.  Original sockaddr_in6 must be
 * v4 mapped addr or v4 compat addr
 */
void
in6_sin6_2_sin(struct sockaddr_in *sin, const struct sockaddr_in6 *sin6)
{

        bzero(sin, sizeof(*sin));
        sin->sin_len = sizeof(struct sockaddr_in);
        sin->sin_family = AF_INET;
        sin->sin_port = sin6->sin6_port;
        sin->sin_addr.s_addr = sin6->sin6_addr.s6_addr32[3];
}

/* Convert sockaddr_in to sockaddr_in6 in v4 mapped addr format. */
void
in6_sin_2_v4mapsin6(const struct sockaddr_in *sin, struct sockaddr_in6 *sin6)
{
        bzero(sin6, sizeof(*sin6));
        sin6->sin6_len = sizeof(struct sockaddr_in6);
        sin6->sin6_family = AF_INET6;
        sin6->sin6_port = sin->sin_port;
        sin6->sin6_addr.s6_addr32[0] = 0;
        sin6->sin6_addr.s6_addr32[1] = 0;
        sin6->sin6_addr.s6_addr32[2] = IPV6_ADDR_INT32_SMP;
        sin6->sin6_addr.s6_addr32[3] = sin->sin_addr.s_addr;
}

/* Convert sockaddr_in6 into sockaddr_in. */
void
in6_sin6_2_sin_in_sock(struct sockaddr *nam)
{
        struct sockaddr_in *sin_p;
        struct sockaddr_in6 sin6;

        /*
         * Save original sockaddr_in6 addr and convert it
         * to sockaddr_in.
         */
        sin6 = *(struct sockaddr_in6 *)nam;
        sin_p = (struct sockaddr_in *)nam;
        in6_sin6_2_sin(sin_p, &sin6);
}

/*
 * Join/leave the solicited multicast groups for proxy NDP entries.
 */
static void
in6_join_proxy_ndp_mc(struct ifnet *ifp, const struct in6_addr *dst)
{
        struct in6_multi *inm;
        struct in6_addr mltaddr;
        char ip6buf[INET6_ADDRSTRLEN];
        int error;

        if (in6_solicited_node_maddr(&mltaddr, ifp, dst) != 0)
                return; /* error logged in in6_solicited_node_maddr. */

        error = in6_joingroup(ifp, &mltaddr, NULL, &inm, 0);
        if (error != 0) {
                nd6log((LOG_WARNING,
                    "%s: in6_joingroup failed for %s on %s (errno=%d)\n",
                    __func__, ip6_sprintf(ip6buf, &mltaddr), if_name(ifp),
                    error));
        }
}

static void
in6_leave_proxy_ndp_mc(struct ifnet *ifp, const struct in6_addr *dst)
{
        struct epoch_tracker et;
        struct in6_multi *inm;
        struct in6_addr mltaddr;
        char ip6buf[INET6_ADDRSTRLEN];

        if (in6_solicited_node_maddr(&mltaddr, ifp, dst) != 0)
                return; /* error logged in in6_solicited_node_maddr. */

        NET_EPOCH_ENTER(et);
        inm = in6m_lookup(ifp, &mltaddr);
        NET_EPOCH_EXIT(et);
        if (inm != NULL)
                in6_leavegroup(inm, NULL);
        else
                nd6log((LOG_WARNING, "%s: in6m_lookup failed for %s on %s\n",
                    __func__, ip6_sprintf(ip6buf, &mltaddr), if_name(ifp)));
}

static bool
in6_lle_match_pub(struct lltable *llt, struct llentry *lle, void *farg)
{
        return ((lle->la_flags & LLE_PUB) != 0);
}

void
in6_purge_proxy_ndp(struct ifnet *ifp)
{
        struct lltable *llt;
        bool need_purge;

        if (ifp->if_inet6 == NULL)
                return;

        llt = LLTABLE6(ifp);
        LLTABLE_LOCK(llt);
        need_purge = ((llt->llt_flags & LLT_ADDEDPROXY) != 0);
        LLTABLE_UNLOCK(llt);

        /*
         * Ever added proxy ndp entries, leave solicited node multicast
         * before deleting the llentry.
         */
        if (need_purge)
                lltable_delete_conditional(llt, in6_lle_match_pub, NULL);
}