kernel - Fix excessive ipiq recursion (4)

[dragonfly.git] / sys / netinet6 / in6_ifattach.c

/*      $FreeBSD: src/sys/netinet6/in6_ifattach.c,v 1.2.2.6 2002/04/28 05:40:26 suz Exp $       */
/*      $KAME: in6_ifattach.c,v 1.118 2001/05/24 07:44:00 itojun Exp $  */

/*
 * 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.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <sys/md5.h>
#include <sys/thread2.h>

#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/netisr2.h>
#include <net/netmsg2.h>

#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/if_ether.h>
#include <netinet/in_pcb.h>
#include <netinet/udp_var.h>

#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_var.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/in6_ifattach.h>
#include <netinet6/nd6.h>
#include <netinet6/scope6_var.h>

#include <net/net_osdep.h>

unsigned long in6_maxmtu = 0;

#ifdef IP6_AUTO_LINKLOCAL
int ip6_auto_linklocal = IP6_AUTO_LINKLOCAL;
#else
int ip6_auto_linklocal = 1;     /* enable by default */
#endif

static struct callout in6_tmpaddrtimer_ch;
static struct netmsg_base in6_tmpaddrtimer_netmsg;

extern struct inpcbinfo ripcbinfo;

static int get_rand_ifid (struct in6_addr *);
static int generate_tmp_ifid (u_int8_t *, const u_int8_t *, u_int8_t *);
static int get_hw_ifid (struct ifnet *, struct in6_addr *);
static int get_ifid (struct ifnet *, struct ifnet *, struct in6_addr *);
static int in6_ifattach_linklocal (struct ifnet *, struct ifnet *);
static int in6_ifattach_loopback (struct ifnet *);

#define EUI64_GBIT      0x01
#define EUI64_UBIT      0x02
#define EUI64_TO_IFID(in6)      do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (0)
#define EUI64_GROUP(in6)        ((in6)->s6_addr[8] & EUI64_GBIT)
#define EUI64_INDIVIDUAL(in6)   (!EUI64_GROUP(in6))
#define EUI64_LOCAL(in6)        ((in6)->s6_addr[8] & EUI64_UBIT)
#define EUI64_UNIVERSAL(in6)    (!EUI64_LOCAL(in6))

#define IFID_LOCAL(in6)         (!EUI64_LOCAL(in6))
#define IFID_UNIVERSAL(in6)     (!EUI64_UNIVERSAL(in6))

/*
 * Generate a last-resort interface identifier, when the machine has no
 * IEEE802/EUI64 address sources.
 * The goal here is to get an interface identifier that is
 * (1) random enough and (2) does not change across reboot.
 * We currently use MD5(hostname) for it.
 */
static int
get_rand_ifid(struct in6_addr *in6)     /* upper 64bits are preserved */
{
        MD5_CTX ctxt;
        u_int8_t digest[16];
        int hostnamelen = strlen(hostname);

#if 0
        /* we need at least several letters as seed for ifid */
        if (hostnamelen < 3)
                return -1;
#endif

        /* generate 8 bytes of pseudo-random value. */
        bzero(&ctxt, sizeof(ctxt));
        MD5Init(&ctxt);
        MD5Update(&ctxt, hostname, hostnamelen);
        MD5Final(digest, &ctxt);

        /* assumes sizeof(digest) > sizeof(ifid) */
        bcopy(digest, &in6->s6_addr[8], 8);

        /* make sure to set "u" bit to local, and "g" bit to individual. */
        in6->s6_addr[8] &= ~EUI64_GBIT; /* g bit to "individual" */
        in6->s6_addr[8] |= EUI64_UBIT;  /* u bit to "local" */

        /* convert EUI64 into IPv6 interface identifier */
        EUI64_TO_IFID(in6);

        return 0;
}

static int
generate_tmp_ifid(u_int8_t *seed0, const u_int8_t *seed1, u_int8_t *ret)
{
        MD5_CTX ctxt;
        u_int8_t seed[16], digest[16], nullbuf[8];
        u_int32_t val32;
        struct timeval tv;

        /* If there's no hisotry, start with a random seed. */
        bzero(nullbuf, sizeof(nullbuf));
        if (bcmp(nullbuf, seed0, sizeof(nullbuf)) == 0) {
                int i;

                for (i = 0; i < 2; i++) {
                        microtime(&tv);
                        val32 = krandom() ^ tv.tv_usec;
                        bcopy(&val32, seed + sizeof(val32) * i, sizeof(val32));
                }
        } else {
                bcopy(seed0, seed, 8);
        }

        /* copy the right-most 64-bits of the given address */
        /* XXX assumption on the size of IFID */
        bcopy(seed1, &seed[8], 8);

        if (0) {                /* for debugging purposes only */
                int i;

                kprintf("generate_tmp_ifid: new randomized ID from: ");
                for (i = 0; i < 16; i++)
                        kprintf("%02x", seed[i]);
                kprintf(" ");
        }

        /* generate 16 bytes of pseudo-random value. */
        bzero(&ctxt, sizeof(ctxt));
        MD5Init(&ctxt);
        MD5Update(&ctxt, seed, sizeof(seed));
        MD5Final(digest, &ctxt);

        /*
         * RFC 3041 3.2.1. (3)
         * Take the left-most 64-bits of the MD5 digest and set bit 6 (the
         * left-most bit is numbered 0) to zero.
         */
        bcopy(digest, ret, 8);
        ret[0] &= ~EUI64_UBIT;

        /*
         * XXX: we'd like to ensure that the generated value is not zero
         * for simplicity.  If the caclculated digest happens to be zero,
         * use a random non-zero value as the last resort.
         */
        if (bcmp(nullbuf, ret, sizeof(nullbuf)) == 0) {
                log(LOG_INFO,
                    "generate_tmp_ifid: computed MD5 value is zero.\n");

                microtime(&tv);
                val32 = krandom() ^ tv.tv_usec;
                val32 = 1 + (val32 % (0xffffffff - 1));
        }

        /*
         * RFC 3041 3.2.1. (4)
         * Take the rightmost 64-bits of the MD5 digest and save them in
         * stable storage as the history value to be used in the next
         * iteration of the algorithm.
         */
        bcopy(&digest[8], seed0, 8);

        if (0) {                /* for debugging purposes only */
                int i;

                kprintf("to: ");
                for (i = 0; i < 16; i++)
                        kprintf("%02x", digest[i]);
                kprintf("\n");
        }

        return 0;
}

/*
 * Get interface identifier for the specified interface.
 * XXX assumes single sockaddr_dl (AF_LINK address) per an interface
 */
static int
get_hw_ifid(struct ifnet *ifp,
            struct in6_addr *in6)       /* upper 64bits are preserved */
{
        struct ifaddr_container *ifac;
        struct sockaddr_dl *sdl;
        u_int8_t *addr;
        size_t addrlen;
        static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
        static u_int8_t allone[8] =
                { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };

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

                if (ifa->ifa_addr->sa_family != AF_LINK)
                        continue;
                sdl = (struct sockaddr_dl *)ifa->ifa_addr;
                if (sdl == NULL)
                        continue;
                if (sdl->sdl_alen == 0)
                        continue;

                goto found;
        }

        return -1;

found:
        addr = LLADDR(sdl);
        addrlen = sdl->sdl_alen;

        /* get EUI64 */
        switch (ifp->if_type) {
        case IFT_ETHER:
        case IFT_ATM:
        case IFT_IEEE1394:
#ifdef IFT_IEEE80211
        case IFT_IEEE80211:
#endif
                /* IEEE802/EUI64 cases - what others? */
                /* IEEE1394 uses 16byte length address starting with EUI64 */
                if (addrlen > 8)
                        addrlen = 8;

                /* look at IEEE802/EUI64 only */
                if (addrlen != 8 && addrlen != 6)
                        return -1;

                /*
                 * check for invalid MAC address - on bsdi, we see it a lot
                 * since wildboar configures all-zero MAC on pccard before
                 * card insertion.
                 */
                if (bcmp(addr, allzero, addrlen) == 0)
                        return -1;
                if (bcmp(addr, allone, addrlen) == 0)
                        return -1;

                /* make EUI64 address */
                if (addrlen == 8)
                        bcopy(addr, &in6->s6_addr[8], 8);
                else if (addrlen == 6) {
                        in6->s6_addr[8] = addr[0];
                        in6->s6_addr[9] = addr[1];
                        in6->s6_addr[10] = addr[2];
                        in6->s6_addr[11] = 0xff;
                        in6->s6_addr[12] = 0xfe;
                        in6->s6_addr[13] = addr[3];
                        in6->s6_addr[14] = addr[4];
                        in6->s6_addr[15] = addr[5];
                }
                break;
        case IFT_GIF:
#ifdef IFT_STF
        case IFT_STF:
#endif
                /*
                 * RFC2893 says: "SHOULD use IPv4 address as ifid source".
                 * however, IPv4 address is not very suitable as unique
                 * identifier source (can be renumbered).
                 * we don't do this.
                 */
                return -1;

        default:
                return -1;
        }

        /* sanity check: g bit must not indicate "group" */
        if (EUI64_GROUP(in6))
                return -1;

        /* convert EUI64 into IPv6 interface identifier */
        EUI64_TO_IFID(in6);

        /*
         * sanity check: ifid must not be all zero, avoid conflict with
         * subnet router anycast
         */
        if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
            bcmp(&in6->s6_addr[9], allzero, 7) == 0) {
                return -1;
        }

        return 0;
}

/*
 * Get interface identifier for the specified interface.  If it is not
 * available on ifp0, borrow interface identifier from other information
 * sources.
 */
static int
get_ifid(struct ifnet *ifp0,
         struct ifnet *altifp,  /* secondary EUI64 source */
         struct in6_addr *in6)
{
        const struct ifnet_array *arr;
        int i;

        /* first, try to get it from the interface itself */
        if (get_hw_ifid(ifp0, in6) == 0) {
                nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n",
                    if_name(ifp0)));
                goto success;
        }

        /* try secondary EUI64 source. this basically is for ATM PVC */
        if (altifp && get_hw_ifid(altifp, in6) == 0) {
                nd6log((LOG_DEBUG, "%s: got interface identifier from %s\n",
                    if_name(ifp0), if_name(altifp)));
                goto success;
        }

        /* next, try to get it from some other hardware interface */
        arr = ifnet_array_get();
        for (i = 0; i < arr->ifnet_count; ++i) {
                struct ifnet *ifp = arr->ifnet_arr[i];

                if (ifp == ifp0)
                        continue;
                if (get_hw_ifid(ifp, in6) != 0)
                        continue;

                /*
                 * to borrow ifid from other interface, ifid needs to be
                 * globally unique
                 */
                if (IFID_UNIVERSAL(in6)) {
                        nd6log((LOG_DEBUG,
                            "%s: borrow interface identifier from %s\n",
                            if_name(ifp0), if_name(ifp)));
                        goto success;
                }
        }

        /* last resort: get from random number source */
        if (get_rand_ifid(in6) == 0) {
                nd6log((LOG_DEBUG,
                    "%s: interface identifier generated by random number\n",
                    if_name(ifp0)));
                goto success;
        }

        kprintf("%s: failed to get interface identifier\n", if_name(ifp0));
        return -1;

success:
        nd6log((LOG_INFO, "%s: ifid: "
                "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
                if_name(ifp0),
                in6->s6_addr[8], in6->s6_addr[9],
                in6->s6_addr[10], in6->s6_addr[11],
                in6->s6_addr[12], in6->s6_addr[13],
                in6->s6_addr[14], in6->s6_addr[15]));
        return 0;
}

static int
in6_ifattach_linklocal(struct ifnet *ifp,
                       struct ifnet *altifp)    /* secondary EUI64 source */
{
        struct in6_ifaddr *ia;
        struct in6_aliasreq ifra;
        struct nd_prefix pr0;
        int i, error;

        /*
         * configure link-local address.
         */
        bzero(&ifra, sizeof(ifra));

        /*
         * in6_update_ifa() does not use ifra_name, but we accurately set it
         * for safety.
         */
        strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));

        ifra.ifra_addr.sin6_family = AF_INET6;
        ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
        ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80);
        ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index); /* XXX */
        ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
        if (ifp->if_flags & IFF_LOOPBACK) {
                ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
                ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
        } else {
                if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) {
                        nd6log((LOG_ERR,
                            "%s: no ifid available\n", if_name(ifp)));
                        return -1;
                }
        }

        ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
        ifra.ifra_prefixmask.sin6_family = AF_INET6;
        ifra.ifra_prefixmask.sin6_addr = in6mask64;

        /* link-local addresses should NEVER expire. */
        ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
        ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;

        /*
         * Do not let in6_update_ifa() do DAD, since we need a random delay
         * before sending an NS at the first time the interface becomes up.
         * Instead, in6_if_up() will start DAD with a proper random delay.
         */
        ifra.ifra_flags |= IN6_IFF_NODAD;

        /*
         * Now call in6_update_ifa() to do a bunch of procedures to configure
         * a link-local address. We can set NULL to the 3rd argument, because
         * we know there's no other link-local address on the interface
         * and therefore we are adding one (instead of updating one).
         */
        if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0) {
                /*
                 * XXX: When the interface does not support IPv6, this call
                 * would fail in the SIOCSIFADDR ioctl.  I believe the
                 * notification is rather confusing in this case, so just
                 * suppress it.  (jinmei@kame.net 20010130)
                 */
                if (error != EAFNOSUPPORT)
                        log(LOG_NOTICE, "in6_ifattach_linklocal: failed to "
                            "configure a link-local address on %s "
                            "(errno=%d)\n",
                            if_name(ifp), error);
                return (-1);
        }

        /*
         * Adjust ia6_flags so that in6_if_up will perform DAD.
         * XXX: Some P2P interfaces seem not to send packets just after
         * becoming up, so we skip p2p interfaces for safety.
         */
        ia = in6ifa_ifpforlinklocal(ifp, 0); /* ia must not be NULL */
#ifdef DIAGNOSTIC
        if (!ia) {
                panic("ia == NULL in in6_ifattach_linklocal");
                /* NOTREACHED */
        }
#endif
        if (in6if_do_dad(ifp) && !(ifp->if_flags & IFF_POINTOPOINT)) {
                ia->ia6_flags &= ~IN6_IFF_NODAD;
                ia->ia6_flags |= IN6_IFF_TENTATIVE;
        }

        /*
         * Make the link-local prefix (fe80::%link/64) as on-link.
         * Since we'd like to manage prefixes separately from addresses,
         * we make an ND6 prefix structure for the link-local prefix,
         * and add it to the prefix list as a never-expire prefix.
         * XXX: this change might affect some existing code base...
         */
        bzero(&pr0, sizeof(pr0));
        pr0.ndpr_ifp = ifp;
        /* this should be 64 at this moment. */
        pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
        pr0.ndpr_mask = ifra.ifra_prefixmask.sin6_addr;
        pr0.ndpr_prefix = ifra.ifra_addr;
        /* apply the mask for safety. (nd6_prelist_add will apply it again) */
        for (i = 0; i < 4; i++) {
                pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
                    in6mask64.s6_addr32[i];
        }
        /*
         * Initialize parameters.  The link-local prefix must always be
         * on-link, and its lifetimes never expire.
         */
        pr0.ndpr_raf_onlink = 1;
        pr0.ndpr_raf_auto = 1;  /* probably meaningless */
        pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
        pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
        /*
         * Since there is no other link-local addresses, nd6_prefix_lookup()
         * probably returns NULL.  However, we cannot always expect the result.
         * For example, if we first remove the (only) existing link-local
         * address, and then reconfigure another one, the prefix is still
         * valid with referring to the old link-local address.
         */
        if (nd6_prefix_lookup(&pr0) == NULL) {
                if ((error = nd6_prelist_add(&pr0, NULL, NULL)) != 0)
                        return (error);
        }

        return 0;
}

static int
in6_ifattach_loopback(struct ifnet *ifp)        /* must be IFT_LOOP */
{
        struct in6_aliasreq ifra;
        int error;

        bzero(&ifra, sizeof(ifra));

        /*
         * in6_update_ifa() does not use ifra_name, but we accurately set it
         * for safety.
         */
        strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));

        ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
        ifra.ifra_prefixmask.sin6_family = AF_INET6;
        ifra.ifra_prefixmask.sin6_addr = in6mask128;

        /*
         * Always initialize ia_dstaddr (= broadcast address) to loopback
         * address.  Follows IPv4 practice - see in_ifinit().
         */
        ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
        ifra.ifra_dstaddr.sin6_family = AF_INET6;
        ifra.ifra_dstaddr.sin6_addr = kin6addr_loopback;

        ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
        ifra.ifra_addr.sin6_family = AF_INET6;
        ifra.ifra_addr.sin6_addr = kin6addr_loopback;

        /* the loopback  address should NEVER expire. */
        ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
        ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;

        /* we don't need to perform DAD on loopback interfaces. */
        ifra.ifra_flags |= IN6_IFF_NODAD;

        /* skip registration to the prefix list. XXX should be temporary. */
        ifra.ifra_flags |= IN6_IFF_NOPFX;

        /*
         * We are sure that this is a newly assigned address, so we can set
         * NULL to the 3rd arg.
         */
        if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0) {
                log(LOG_ERR, "in6_ifattach_loopback: failed to configure "
                    "the loopback address on %s (errno=%d)\n",
                    if_name(ifp), error);
                return (-1);
        }

        return 0;
}

/*
 * compute NI group address, based on the current hostname setting.
 * see draft-ietf-ipngwg-icmp-name-lookup-* (04 and later).
 *
 * when ifp == NULL, the caller is responsible for filling scopeid.
 */
int
in6_nigroup(struct ifnet *ifp, const char *name, int namelen,
            struct in6_addr *in6)
{
        const char *p;
        u_char *q;
        MD5_CTX ctxt;
        u_int8_t digest[16];
        char l;
        char n[64];     /* a single label must not exceed 63 chars */

        if (!namelen || !name)
                return -1;

        p = name;
        while (p && *p && *p != '.' && p - name < namelen)
                p++;
        if (p - name > sizeof(n) - 1)
                return -1;      /* label too long */
        l = p - name;
        strncpy(n, name, l);
        n[(int)l] = '\0';
        for (q = n; *q; q++) {
                if ('A' <= *q && *q <= 'Z')
                        *q = *q - 'A' + 'a';
        }

        /* generate 8 bytes of pseudo-random value. */
        bzero(&ctxt, sizeof(ctxt));
        MD5Init(&ctxt);
        MD5Update(&ctxt, &l, sizeof(l));
        MD5Update(&ctxt, n, l);
        MD5Final(digest, &ctxt);

        bzero(in6, sizeof(*in6));
        in6->s6_addr16[0] = htons(0xff02);
        if (ifp)
                in6->s6_addr16[1] = htons(ifp->if_index);
        in6->s6_addr8[11] = 2;
        bcopy(digest, &in6->s6_addr32[3], sizeof(in6->s6_addr32[3]));

        return 0;
}

struct netmsg_nigroup {
        struct netmsg_base      nmsg;
        const char              *name;
        int                     namelen;
};

static void
in6_nigroup_attach_dispatch(netmsg_t msg)
{
        struct netmsg_nigroup *nmsg = (struct netmsg_nigroup *)msg;
        struct sockaddr_in6 mltaddr;
        struct in6_multi *in6m;
        const struct ifnet_array *arr;
        int error, i;

        bzero(&mltaddr, sizeof(mltaddr));
        mltaddr.sin6_family = AF_INET6;
        mltaddr.sin6_len = sizeof(struct sockaddr_in6);
        if (in6_nigroup(NULL, nmsg->name, nmsg->namelen,
            &mltaddr.sin6_addr) != 0)
                goto done;

        arr = ifnet_array_get();
        for (i = 0; i < arr->ifnet_count; ++i) {
                struct ifnet *ifp = arr->ifnet_arr[i];

                mltaddr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
                in6m = IN6_LOOKUP_MULTI(&mltaddr.sin6_addr, ifp);
                if (!in6m) {
                        if (!in6_addmulti(&mltaddr.sin6_addr, ifp, &error)) {
                                nd6log((LOG_ERR, "%s: failed to join %s "
                                    "(errno=%d)\n", if_name(ifp),
                                    ip6_sprintf(&mltaddr.sin6_addr),
                                    error));
                        }
                }
        }
done:
        lwkt_replymsg(&nmsg->nmsg.lmsg, 0);
}

void
in6_nigroup_attach(const char *name, int namelen)
{
        struct netmsg_nigroup nmsg;

        netmsg_init(&nmsg.nmsg, NULL, &curthread->td_msgport, 0,
            in6_nigroup_attach_dispatch);
        nmsg.name = name;
        nmsg.namelen = namelen;
        lwkt_domsg(netisr_cpuport(0), &nmsg.nmsg.lmsg, 0);
}

static void
in6_nigroup_detach_dispatch(netmsg_t msg)
{
        struct netmsg_nigroup *nmsg = (struct netmsg_nigroup *)msg;
        struct sockaddr_in6 mltaddr;
        struct in6_multi *in6m;
        const struct ifnet_array *arr;
        int i;

        bzero(&mltaddr, sizeof(mltaddr));
        mltaddr.sin6_family = AF_INET6;
        mltaddr.sin6_len = sizeof(struct sockaddr_in6);
        if (in6_nigroup(NULL, nmsg->name, nmsg->namelen,
            &mltaddr.sin6_addr) != 0)
                goto done;

        arr = ifnet_array_get();
        for (i = 0; i < arr->ifnet_count; ++i) {
                struct ifnet *ifp = arr->ifnet_arr[i];

                mltaddr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
                in6m = IN6_LOOKUP_MULTI(&mltaddr.sin6_addr, ifp);
                if (in6m)
                        in6_delmulti(in6m);
        }
done:
        lwkt_replymsg(&nmsg->nmsg.lmsg, 0);
}

void
in6_nigroup_detach(const char *name, int namelen)
{
        struct netmsg_nigroup nmsg;

        netmsg_init(&nmsg.nmsg, NULL, &curthread->td_msgport, 0,
            in6_nigroup_detach_dispatch);
        nmsg.name = name;
        nmsg.namelen = namelen;
        lwkt_domsg(netisr_cpuport(0), &nmsg.nmsg.lmsg, 0);
}

/*
 * XXX multiple loopback interface needs more care.  for instance,
 * nodelocal address needs to be configured onto only one of them.
 * XXX multiple link-local address case
 */
void
in6_ifattach(struct ifnet *ifp,
             struct ifnet *altifp)      /* secondary EUI64 source */
{
        struct in6_ifaddr *ia;
        struct in6_addr in6;

        /* some of the interfaces are inherently not IPv6 capable */
        switch (ifp->if_type) {
#ifdef IFT_BRIDGE       /* OpenBSD 2.8, NetBSD 1.6 */
        case IFT_BRIDGE:
                return;
#endif
        case IFT_PFLOG:
        case IFT_PFSYNC:
        case IFT_CARP:
                return;
        }

        /*
         * quirks based on interface type
         */
        switch (ifp->if_type) {
#ifdef IFT_STF
        case IFT_STF:
                /*
                 * 6to4 interface is a very special kind of beast.
                 * no multicast, no linklocal.  RFC2529 specifies how to make
                 * linklocals for 6to4 interface, but there's no use and
                 * it is rather harmful to have one.
                 */
                goto statinit;
#endif
        default:
                break;
        }

        /*
         * usually, we require multicast capability to the interface
         */
        if (!(ifp->if_flags & IFF_MULTICAST)) {
                log(LOG_INFO, "in6_ifattach: "
                    "%s is not multicast capable, IPv6 not enabled\n",
                    if_name(ifp));
                return;
        }

        /*
         * assign loopback address for loopback interface.
         * XXX multiple loopback interface case.
         */
        if (ifp->if_flags & IFF_LOOPBACK) {
                in6 = kin6addr_loopback;
                if (in6ifa_ifpwithaddr(ifp, &in6) == NULL) {
                        if (in6_ifattach_loopback(ifp) != 0)
                                return;
                }
        }

        /*
         * assign a link-local address, if there's none.
         */
        if (ip6_auto_linklocal) {
                ia = in6ifa_ifpforlinklocal(ifp, 0);
                if (ia == NULL) {
                        if (in6_ifattach_linklocal(ifp, altifp) == 0) {
                                /* linklocal address assigned */
                        } else {
                                /* failed to assign linklocal address. bark? */
                        }
                }
        }

#ifdef IFT_STF                  /* XXX */
statinit:
#endif

        /* update dynamically. */
        if (in6_maxmtu < ifp->if_mtu)
                in6_maxmtu = ifp->if_mtu;
}

/*
 * NOTE: in6_ifdetach() does not support loopback if at this moment.
 */
static void
in6_ifdetach_dispatch(netmsg_t nmsg)
{
        struct lwkt_msg *lmsg = &nmsg->lmsg;
        struct ifnet *ifp = lmsg->u.ms_resultp;
        struct ifaddr_container *ifac, *next;
        struct rtentry *rt;
        struct sockaddr_in6 sin6;
        struct in6_multi *in6m, *in6m_next;

        ASSERT_IN_NETISR(0);

        /* remove neighbor management table */
        nd6_purge(ifp);

        /* nuke any of IPv6 addresses we have */
        TAILQ_FOREACH_MUTABLE(ifac, &ifp->if_addrheads[mycpuid], ifa_link,
            next) {
                struct ifaddr *ifa = ifac->ifa;

                if (ifa->ifa_addr->sa_family != AF_INET6)
                        continue;
                in6_purgeaddr(ifa);
        }

        /*
         * XXX
         * These were code trying to nuke inet6 addresses again, but all
         * inet6 addresses must have been deleted above; use assertion.
         */
        TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
                KASSERT(ifac->ifa->ifa_addr->sa_family != AF_INET6,
                    ("still has inet6 addr"));
        }

        /* leave from all multicast groups joined */
        in6_pcbpurgeif0(&ripcbinfo, ifp);
        in6_pcbpurgeif0(&udbinfo[0], ifp);
        for (in6m = LIST_FIRST(&in6_multihead); in6m; in6m = in6m_next) {
                in6m_next = LIST_NEXT(in6m, in6m_entry);
                if (in6m->in6m_ifp != ifp)
                        continue;
                in6_delmulti(in6m);
                in6m = NULL;
        }

        /*
         * remove neighbor management table.  we call it twice just to make
         * sure we nuke everything.  maybe we need just one call.
         * XXX: since the first call did not release addresses, some prefixes
         * might remain.  We should call nd6_purge() again to release the
         * prefixes after removing all addresses above.
         * (Or can we just delay calling nd6_purge until at this point?)
         */
        nd6_purge(ifp);

        /* remove route to link-local allnodes multicast (ff02::1) */
        bzero(&sin6, sizeof(sin6));
        sin6.sin6_len = sizeof(struct sockaddr_in6);
        sin6.sin6_family = AF_INET6;
        sin6.sin6_addr = kin6addr_linklocal_allnodes;
        sin6.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
        rt = rtpurelookup((struct sockaddr *)&sin6);
        if (rt != NULL && rt->rt_ifp == ifp) {
                --rt->rt_refcnt;
                rtrequest(RTM_DELETE, (struct sockaddr *)rt_key(rt),
                    rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
        }

        lwkt_replymsg(lmsg, 0);
}

void
in6_ifdetach(struct ifnet *ifp)
{
        struct netmsg_base nmsg;
        struct lwkt_msg *lmsg = &nmsg.lmsg;

        netmsg_init(&nmsg, NULL, &curthread->td_msgport, 0,
            in6_ifdetach_dispatch);
        lmsg->u.ms_resultp = ifp;
        lwkt_domsg(netisr_cpuport(0), lmsg, 0);
}

void
in6_get_tmpifid(struct ifnet *ifp, u_int8_t *retbuf, const u_int8_t *baseid,
                int generate)
{
        u_int8_t nullbuf[8];
        struct nd_ifinfo *ndi = ND_IFINFO(ifp);

        bzero(nullbuf, sizeof(nullbuf));
        if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
                /* we've never created a random ID.  Create a new one. */
                generate = 1;
        }

        if (generate) {
                bcopy(baseid, ndi->randomseed1, sizeof(ndi->randomseed1));

                /* generate_tmp_ifid will update seedn and buf */
                generate_tmp_ifid(ndi->randomseed0, ndi->randomseed1,
                                  ndi->randomid);
        }
        bcopy(ndi->randomid, retbuf, 8);
}

static void
in6_tmpaddrtimer(void *arg __unused)
{
        struct lwkt_msg *lmsg = &in6_tmpaddrtimer_netmsg.lmsg;

        KASSERT(mycpuid == 0, ("not on cpu0"));
        crit_enter();
        if (lmsg->ms_flags & MSGF_DONE)
                lwkt_sendmsg_oncpu(netisr_cpuport(0), lmsg);
        crit_exit();
}

static void
in6_tmpaddrtimer_dispatch(netmsg_t nmsg)
{
        const struct ifnet_array *arr;
        struct nd_ifinfo *ndi;
        u_int8_t nullbuf[8];
        int i;

        ASSERT_IN_NETISR(0);

        crit_enter();
        lwkt_replymsg(&nmsg->lmsg, 0);  /* reply ASAP */
        crit_exit();

        bzero(nullbuf, sizeof(nullbuf));
        arr = ifnet_array_get();
        for (i = 0; i < arr->ifnet_count; ++i) {
                struct ifnet *ifp = arr->ifnet_arr[i];

                if (ifp->if_afdata[AF_INET6] == NULL)
                        continue;
                ndi = ND_IFINFO(ifp);
                if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
                        /*
                         * We've been generating a random ID on this interface.
                         * Create a new one.
                         */
                        generate_tmp_ifid(ndi->randomseed0,
                                          ndi->randomseed1,
                                          ndi->randomid);
                }
        }

        callout_reset(&in6_tmpaddrtimer_ch,
                      (ip6_temp_preferred_lifetime - ip6_desync_factor -
                       ip6_temp_regen_advance) * hz,
                      in6_tmpaddrtimer, NULL);
}

/*
 * Timer for regeneranation of temporary addresses randomize ID
 */
void
in6_tmpaddrtimer_init(void)
{
        callout_init_mp(&in6_tmpaddrtimer_ch);
        netmsg_init(&in6_tmpaddrtimer_netmsg, NULL, &netisr_adone_rport,
            MSGF_PRIORITY, in6_tmpaddrtimer_dispatch);
        callout_reset_bycpu(&in6_tmpaddrtimer_ch,
            (ip6_temp_preferred_lifetime - ip6_desync_factor -
             ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, NULL, 0);
}