xref: /dragonfly/sys/netinet6/in6_ifattach.c (revision 5f39c7e7)

/*	$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 <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

struct callout in6_tmpaddrtimer_ch;

extern struct inpcbinfo ripcbinfo;

static int get_rand_ifid (struct ifnet *, 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 ifnet *ifp,
	      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)
{
	struct ifnet *ifp;

	/* 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 */
	TAILQ_FOREACH(ifp, &ifnet, if_list) {
		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(ifp, 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
		 * supress 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::/64%link) 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;
}

void
in6_nigroup_attach(const char *name, int namelen)
{
	struct ifnet *ifp;
	struct sockaddr_in6 mltaddr;
	struct in6_multi *in6m;
	int error;

	bzero(&mltaddr, sizeof(mltaddr));
	mltaddr.sin6_family = AF_INET6;
	mltaddr.sin6_len = sizeof(struct sockaddr_in6);
	if (in6_nigroup(NULL, name, namelen, &mltaddr.sin6_addr) != 0)
		return;

	TAILQ_FOREACH(ifp, &ifnet, if_list) {
		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));
			}
		}
	}
}

void
in6_nigroup_detach(const char *name, int namelen)
{
	struct ifnet *ifp;
	struct sockaddr_in6 mltaddr;
	struct in6_multi *in6m;

	bzero(&mltaddr, sizeof(mltaddr));
	mltaddr.sin6_family = AF_INET6;
	mltaddr.sin6_len = sizeof(struct sockaddr_in6);
	if (in6_nigroup(NULL, name, namelen, &mltaddr.sin6_addr) != 0)
		return;

	TAILQ_FOREACH(ifp, &ifnet, if_list) {
		mltaddr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
		in6m = IN6_LOOKUP_MULTI(&mltaddr.sin6_addr, ifp);
		if (in6m)
			in6_delmulti(in6m);
	}
}

/*
 * 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*/
	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.
 * We don't need this function in bsdi, because interfaces are never removed
 * from the ifnet list in bsdi.
 */
void
in6_ifdetach(struct ifnet *ifp)
{
	struct in6_ifaddr *ia, *oia;
	struct ifaddr_container *ifac, *next;
	struct rtentry *rt;
	short rtflags;
	struct sockaddr_in6 sin6;
	struct in6_multi *in6m;
	struct in6_multi *in6m_next;

	/* nuke prefix list.  this may try to remove some of ifaddrs as well */
	in6_purgeprefix(ifp);

	/* 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);
	}

	/* undo everything done by in6_ifattach(), just in case */
	TAILQ_FOREACH_MUTABLE(ifac, &ifp->if_addrheads[mycpuid], ifa_link, next) {
		struct ifaddr *ifa = ifac->ifa;

		if (ifa->ifa_addr->sa_family != AF_INET6
		 || !IN6_IS_ADDR_LINKLOCAL(&satosin6(&ifa->ifa_addr)->sin6_addr)) {
			continue;
		}

		ia = (struct in6_ifaddr *)ifa;

		/* remove from the routing table */
		if ((ia->ia_flags & IFA_ROUTE) &&
		    (rt = rtpurelookup((struct sockaddr *)&ia->ia_addr))) {
			rtflags = rt->rt_flags;
			--rt->rt_refcnt;
			rtrequest(RTM_DELETE,
				(struct sockaddr *)&ia->ia_addr,
				(struct sockaddr *)&ia->ia_addr,
				(struct sockaddr *)&ia->ia_prefixmask,
				rtflags, NULL);
		}

		/* remove from the linked list */
		ifa_ifunlink((struct ifaddr *)ia, ifp);

		/* also remove from the IPv6 address chain(itojun&jinmei) */
		oia = ia;
		if (oia == (ia = in6_ifaddr))
			in6_ifaddr = ia->ia_next;
		else {
			while (ia->ia_next && (ia->ia_next != oia))
				ia = ia->ia_next;
			if (ia->ia_next)
				ia->ia_next = oia->ia_next;
			else {
				nd6log((LOG_ERR,
				    "%s: didn't unlink in6ifaddr from "
				    "list\n", if_name(ifp)));
			}
		}

		crit_enter();	/* XXX MP not MP safe */
		_IFAFREE(&oia->ia_ifa, 0);
		crit_exit();

		ifa_destroy(&ia->ia_ifa);
	}

	/* leave from all multicast groups joined */
	udbinfo_lock();
	in6_pcbpurgeif0(LIST_FIRST(&udbinfo.pcblisthead), ifp);
	udbinfo_unlock();

	in6_pcbpurgeif0(LIST_FIRST(&ripcbinfo.pcblisthead), 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);
	}
}

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);
}

void
in6_tmpaddrtimer(void *ignored_arg)
{
	struct nd_ifinfo *ndi;
	u_int8_t nullbuf[8];
	struct ifnet *ifp;

	crit_enter();

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

	bzero(nullbuf, sizeof(nullbuf));
	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
		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);
		}
	}

	crit_exit();
}