in6_ifattach.c revision 1.77
1/*	$OpenBSD: in6_ifattach.c,v 1.77 2014/11/20 09:55:57 mpi Exp $	*/
2/*	$KAME: in6_ifattach.c,v 1.124 2001/07/18 08:32:51 jinmei Exp $	*/
3
4/*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/param.h>
34#include <sys/systm.h>
35#include <sys/socket.h>
36#include <sys/sockio.h>
37#include <sys/kernel.h>
38#include <sys/syslog.h>
39
40#include <crypto/md5.h>
41
42#include <net/if.h>
43#include <net/if_var.h>
44#include <net/if_dl.h>
45#include <net/if_types.h>
46#include <net/route.h>
47
48#include <netinet/in.h>
49#include <netinet/if_ether.h>
50
51#include <netinet6/in6_var.h>
52#include <netinet/ip6.h>
53#include <netinet6/ip6_var.h>
54#include <netinet6/in6_ifattach.h>
55#include <netinet6/nd6.h>
56#ifdef MROUTING
57#include <netinet6/ip6_mroute.h>
58#endif
59
60int ip6_auto_linklocal = 1;	/* enable by default */
61
62int get_last_resort_ifid(struct ifnet *, struct in6_addr *);
63int get_hw_ifid(struct ifnet *, struct in6_addr *);
64int get_ifid(struct ifnet *, struct in6_addr *);
65int in6_ifattach_loopback(struct ifnet *);
66
67#define EUI64_GBIT	0x01
68#define EUI64_UBIT	0x02
69#define EUI64_TO_IFID(in6)	do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (0)
70#define EUI64_GROUP(in6)	((in6)->s6_addr[8] & EUI64_GBIT)
71#define EUI64_INDIVIDUAL(in6)	(!EUI64_GROUP(in6))
72#define EUI64_LOCAL(in6)	((in6)->s6_addr[8] & EUI64_UBIT)
73#define EUI64_UNIVERSAL(in6)	(!EUI64_LOCAL(in6))
74
75#define IFID_LOCAL(in6)		(!EUI64_LOCAL(in6))
76#define IFID_UNIVERSAL(in6)	(!EUI64_UNIVERSAL(in6))
77
78/*
79 * Generate a last-resort interface identifier, when the machine has no
80 * IEEE802/EUI64 address sources.
81 * The goal here is to get an interface identifier that is
82 * (1) random enough and (2) does not change across reboot.
83 * We currently use MD5(hostname) for it.
84 *
85 * in6 - upper 64bits are preserved
86 */
87int
88get_last_resort_ifid(struct ifnet *ifp, struct in6_addr *in6)
89{
90	MD5_CTX ctxt;
91	u_int8_t digest[16];
92
93#if 0
94	/* we need at least several letters as seed for ifid */
95	if (hostnamelen < 3)
96		return -1;
97#endif
98
99	/* generate 8 bytes of pseudo-random value. */
100	bzero(&ctxt, sizeof(ctxt));
101	MD5Init(&ctxt);
102	MD5Update(&ctxt, hostname, hostnamelen);
103	MD5Final(digest, &ctxt);
104
105	/* assumes sizeof(digest) > sizeof(ifid) */
106	bcopy(digest, &in6->s6_addr[8], 8);
107
108	/* make sure to set "u" bit to local, and "g" bit to individual. */
109	in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
110	in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
111
112	/* convert EUI64 into IPv6 interface identifier */
113	EUI64_TO_IFID(in6);
114
115	return 0;
116}
117
118/*
119 * Generate a random interface identifier.
120 *
121 * in6 - upper 64bits are preserved
122 */
123void
124in6_get_rand_ifid(struct ifnet *ifp, struct in6_addr *in6)
125{
126	arc4random_buf(&in6->s6_addr32[2], 8);
127
128	/* make sure to set "u" bit to local, and "g" bit to individual. */
129	in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
130	in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
131
132	/* convert EUI64 into IPv6 interface identifier */
133	EUI64_TO_IFID(in6);
134}
135
136/*
137 * Get interface identifier for the specified interface.
138 *
139 * in6 - upper 64bits are preserved
140 */
141int
142get_hw_ifid(struct ifnet *ifp, struct in6_addr *in6)
143{
144	struct sockaddr_dl *sdl;
145	char *addr;
146	size_t addrlen;
147	static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
148	static u_int8_t allone[8] =
149		{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
150
151	sdl = (struct sockaddr_dl *)ifp->if_sadl;
152	if (sdl == NULL || sdl->sdl_alen == 0)
153		return -1;
154
155	addr = LLADDR(sdl);
156	addrlen = sdl->sdl_alen;
157
158	switch (ifp->if_type) {
159	case IFT_IEEE1394:
160	case IFT_IEEE80211:
161		/* IEEE1394 uses 16byte length address starting with EUI64 */
162		if (addrlen > 8)
163			addrlen = 8;
164		break;
165	default:
166		break;
167	}
168
169	/* get EUI64 */
170	switch (ifp->if_type) {
171	/* IEEE802/EUI64 cases - what others? */
172	case IFT_ETHER:
173	case IFT_CARP:
174	case IFT_IEEE1394:
175	case IFT_IEEE80211:
176		/* look at IEEE802/EUI64 only */
177		if (addrlen != 8 && addrlen != 6)
178			return -1;
179
180		/*
181		 * check for invalid MAC address - on bsdi, we see it a lot
182		 * since wildboar configures all-zero MAC on pccard before
183		 * card insertion.
184		 */
185		if (bcmp(addr, allzero, addrlen) == 0)
186			return -1;
187		if (bcmp(addr, allone, addrlen) == 0)
188			return -1;
189
190		/* make EUI64 address */
191		if (addrlen == 8)
192			bcopy(addr, &in6->s6_addr[8], 8);
193		else if (addrlen == 6) {
194			in6->s6_addr[8] = addr[0];
195			in6->s6_addr[9] = addr[1];
196			in6->s6_addr[10] = addr[2];
197			in6->s6_addr[11] = 0xff;
198			in6->s6_addr[12] = 0xfe;
199			in6->s6_addr[13] = addr[3];
200			in6->s6_addr[14] = addr[4];
201			in6->s6_addr[15] = addr[5];
202		}
203		break;
204
205	case IFT_GIF:
206		/*
207		 * RFC2893 says: "SHOULD use IPv4 address as ifid source".
208		 * however, IPv4 address is not very suitable as unique
209		 * identifier source (can be renumbered).
210		 * we don't do this.
211		 */
212		return -1;
213
214	default:
215		return -1;
216	}
217
218	/* sanity check: g bit must not indicate "group" */
219	if (EUI64_GROUP(in6))
220		return -1;
221
222	/* convert EUI64 into IPv6 interface identifier */
223	EUI64_TO_IFID(in6);
224
225	/*
226	 * sanity check: ifid must not be all zero, avoid conflict with
227	 * subnet router anycast
228	 */
229	if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
230	    bcmp(&in6->s6_addr[9], allzero, 7) == 0) {
231		return -1;
232	}
233
234	return 0;
235}
236
237/*
238 * Get interface identifier for the specified interface.  If it is not
239 * available on ifp0, borrow interface identifier from other information
240 * sources.
241 */
242int
243get_ifid(struct ifnet *ifp0, struct in6_addr *in6)
244{
245	struct ifnet *ifp;
246
247	/* first, try to get it from the interface itself */
248	if (get_hw_ifid(ifp0, in6) == 0) {
249		nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n",
250		    ifp0->if_xname));
251		goto success;
252	}
253
254	/* next, try to get it from some other hardware interface */
255	TAILQ_FOREACH(ifp, &ifnet, if_list) {
256		if (ifp == ifp0)
257			continue;
258		if (get_hw_ifid(ifp, in6) != 0)
259			continue;
260
261		/*
262		 * to borrow ifid from other interface, ifid needs to be
263		 * globally unique
264		 */
265		if (IFID_UNIVERSAL(in6)) {
266			nd6log((LOG_DEBUG,
267			    "%s: borrow interface identifier from %s\n",
268			    ifp0->if_xname, ifp->if_xname));
269			goto success;
270		}
271	}
272
273	/* last resort: get from random number source */
274	if (get_last_resort_ifid(ifp, in6) == 0) {
275		nd6log((LOG_DEBUG,
276		    "%s: interface identifier generated by random number\n",
277		    ifp0->if_xname));
278		goto success;
279	}
280
281	printf("%s: failed to get interface identifier\n", ifp0->if_xname);
282	return -1;
283
284success:
285	nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
286	    ifp0->if_xname, in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10],
287	    in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13],
288	    in6->s6_addr[14], in6->s6_addr[15]));
289	return 0;
290}
291
292/*
293 * ifid - used as EUI64 if not NULL, overrides other EUI64 sources
294 */
295
296int
297in6_ifattach_linklocal(struct ifnet *ifp, struct in6_addr *ifid)
298{
299	struct in6_ifaddr *ia6;
300	struct in6_aliasreq ifra;
301	struct nd_prefix pr0;
302	int i, s, error;
303
304	/*
305	 * configure link-local address.
306	 */
307	bzero(&ifra, sizeof(ifra));
308
309	/*
310	 * in6_update_ifa() does not use ifra_name, but we accurately set it
311	 * for safety.
312	 */
313	strncpy(ifra.ifra_name, ifp->if_xname, sizeof(ifra.ifra_name));
314
315	ifra.ifra_addr.sin6_family = AF_INET6;
316	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
317	ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80);
318	ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
319	ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
320	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
321		ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
322		ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
323	} else if (ifid) {
324		ifra.ifra_addr.sin6_addr = *ifid;
325		ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80);
326		ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
327		ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
328		ifra.ifra_addr.sin6_addr.s6_addr[8] &= ~EUI64_GBIT;
329		ifra.ifra_addr.sin6_addr.s6_addr[8] |= EUI64_UBIT;
330	} else {
331		if (get_ifid(ifp, &ifra.ifra_addr.sin6_addr) != 0) {
332			nd6log((LOG_ERR,
333			    "%s: no ifid available\n", ifp->if_xname));
334			return (-1);
335		}
336	}
337
338	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
339	ifra.ifra_prefixmask.sin6_family = AF_INET6;
340	ifra.ifra_prefixmask.sin6_addr = in6mask64;
341	/* link-local addresses should NEVER expire. */
342	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
343	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
344
345	/*
346	 * Do not let in6_update_ifa() do DAD, since we need a random delay
347	 * before sending an NS at the first time the interface becomes up.
348	 * Instead, in6_if_up() will start DAD with a proper random delay.
349	 */
350	ifra.ifra_flags |= IN6_IFF_NODAD;
351
352	/*
353	 * Now call in6_update_ifa() to do a bunch of procedures to configure
354	 * a link-local address. In the case of CARP, we may be called after
355	 * one has already been configured, so check if it's already there
356	 * with in6ifa_ifpforlinklocal() and clobber it if it exists.
357	 */
358	s = splsoftnet();
359	error = in6_update_ifa(ifp, &ifra, in6ifa_ifpforlinklocal(ifp, 0));
360	splx(s);
361
362	if (error != 0) {
363		/*
364		 * XXX: When the interface does not support IPv6, this call
365		 * would fail in the SIOCSIFADDR ioctl.  I believe the
366		 * notification is rather confusing in this case, so just
367		 * suppress it.  (jinmei@kame.net 20010130)
368		 */
369		if (error != EAFNOSUPPORT)
370			nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to "
371			    "configure a link-local address on %s "
372			    "(errno=%d)\n",
373			    ifp->if_xname, error));
374		return (-1);
375	}
376
377	/*
378	 * Adjust ia6_flags so that in6_if_up will perform DAD.
379	 * XXX: Some P2P interfaces seem not to send packets just after
380	 * becoming up, so we skip p2p interfaces for safety.
381	 */
382	ia6 = in6ifa_ifpforlinklocal(ifp, 0); /* ia6 must not be NULL */
383#ifdef DIAGNOSTIC
384	if (!ia6) {
385		panic("ia6 == NULL in in6_ifattach_linklocal");
386		/* NOTREACHED */
387	}
388#endif
389	if (in6if_do_dad(ifp) && ((ifp->if_flags & IFF_POINTOPOINT) ||
390	    (ifp->if_type == IFT_CARP)) == 0) {
391		ia6->ia6_flags &= ~IN6_IFF_NODAD;
392		ia6->ia6_flags |= IN6_IFF_TENTATIVE;
393	}
394
395	/*
396	 * Make the link-local prefix (fe80::/64%link) as on-link.
397	 * Since we'd like to manage prefixes separately from addresses,
398	 * we make an ND6 prefix structure for the link-local prefix,
399	 * and add it to the prefix list as a never-expire prefix.
400	 * XXX: this change might affect some existing code base...
401	 */
402	bzero(&pr0, sizeof(pr0));
403	pr0.ndpr_ifp = ifp;
404	/* this should be 64 at this moment. */
405	pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
406	pr0.ndpr_mask = ifra.ifra_prefixmask.sin6_addr;
407	pr0.ndpr_prefix = ifra.ifra_addr;
408	/* apply the mask for safety. (nd6_prelist_add will apply it again) */
409	for (i = 0; i < 4; i++) {
410		pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
411		    in6mask64.s6_addr32[i];
412	}
413	/*
414	 * Initialize parameters.  The link-local prefix must always be
415	 * on-link, and its lifetimes never expire.
416	 */
417	pr0.ndpr_raf_onlink = 1;
418	pr0.ndpr_raf_auto = 1;	/* probably meaningless */
419	pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
420	pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
421	/*
422	 * Since there is no other link-local addresses, nd6_prefix_lookup()
423	 * probably returns NULL.  However, we cannot always expect the result.
424	 * For example, if we first remove the (only) existing link-local
425	 * address, and then reconfigure another one, the prefix is still
426	 * valid with referring to the old link-local address.
427	 */
428	if (nd6_prefix_lookup(&pr0) == NULL) {
429		if ((error = nd6_prelist_add(&pr0, NULL, NULL)) != 0)
430			return (error);
431	}
432
433	return 0;
434}
435
436/*
437 * ifp - must be IFT_LOOP
438 */
439
440int
441in6_ifattach_loopback(struct ifnet *ifp)
442{
443	struct in6_aliasreq ifra;
444	int error;
445
446	bzero(&ifra, sizeof(ifra));
447
448	/*
449	 * in6_update_ifa() does not use ifra_name, but we accurately set it
450	 * for safety.
451	 */
452	strncpy(ifra.ifra_name, ifp->if_xname, sizeof(ifra.ifra_name));
453
454	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
455	ifra.ifra_prefixmask.sin6_family = AF_INET6;
456	ifra.ifra_prefixmask.sin6_addr = in6mask128;
457
458	/*
459	 * Always initialize ia_dstaddr (= broadcast address) to loopback
460	 * address.  Follows IPv4 practice - see in_ifinit().
461	 */
462	ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
463	ifra.ifra_dstaddr.sin6_family = AF_INET6;
464	ifra.ifra_dstaddr.sin6_addr = in6addr_loopback;
465
466	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
467	ifra.ifra_addr.sin6_family = AF_INET6;
468	ifra.ifra_addr.sin6_addr = in6addr_loopback;
469
470	/* the loopback  address should NEVER expire. */
471	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
472	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
473
474	/* we don't need to perform DAD on loopback interfaces. */
475	ifra.ifra_flags |= IN6_IFF_NODAD;
476
477	/*
478	 * We are sure that this is a newly assigned address, so we can set
479	 * NULL to the 3rd arg.
480	 */
481	if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0) {
482		nd6log((LOG_ERR, "in6_ifattach_loopback: failed to configure "
483		    "the loopback address on %s (errno=%d)\n",
484		    ifp->if_xname, error));
485		return (-1);
486	}
487
488	return 0;
489}
490
491/*
492 * compute NI group address, based on the current hostname setting.
493 * see draft-ietf-ipngwg-icmp-name-lookup-* (04 and later).
494 *
495 * when ifp == NULL, the caller is responsible for filling scopeid.
496 */
497int
498in6_nigroup(struct ifnet *ifp, const char *name, int namelen,
499    struct sockaddr_in6 *sa6)
500{
501	const char *p;
502	u_int8_t *q;
503	MD5_CTX ctxt;
504	u_int8_t digest[16];
505	u_int8_t l;
506	u_int8_t n[64];	/* a single label must not exceed 63 chars */
507
508	if (!namelen || !name)
509		return -1;
510
511	p = name;
512	while (p && *p && *p != '.' && p - name < namelen)
513		p++;
514	if (p - name > sizeof(n) - 1)
515		return -1;	/* label too long */
516	l = p - name;
517	strncpy((char *)n, name, l);
518	n[(int)l] = '\0';
519	for (q = n; *q; q++) {
520		if ('A' <= *q && *q <= 'Z')
521			*q = *q - 'A' + 'a';
522	}
523
524	/* generate 8 bytes of pseudo-random value. */
525	bzero(&ctxt, sizeof(ctxt));
526	MD5Init(&ctxt);
527	MD5Update(&ctxt, &l, sizeof(l));
528	MD5Update(&ctxt, n, l);
529	MD5Final(digest, &ctxt);
530
531	bzero(sa6, sizeof(*sa6));
532	sa6->sin6_family = AF_INET6;
533	sa6->sin6_len = sizeof(*sa6);
534	sa6->sin6_addr.s6_addr16[0] = htons(0xff02);
535	sa6->sin6_addr.s6_addr16[1] = htons(ifp->if_index);
536	sa6->sin6_addr.s6_addr8[11] = 2;
537	bcopy(digest, &sa6->sin6_addr.s6_addr32[3],
538	    sizeof(sa6->sin6_addr.s6_addr32[3]));
539
540	return 0;
541}
542
543/*
544 * XXX multiple loopback interface needs more care.  for instance,
545 * nodelocal address needs to be configured onto only one of them.
546 * XXX multiple link-local address case
547 */
548void
549in6_ifattach(struct ifnet *ifp)
550{
551	struct in6_ifaddr *ia6;
552	struct in6_addr in6;
553
554	/* some of the interfaces are inherently not IPv6 capable */
555	switch (ifp->if_type) {
556	case IFT_BRIDGE:
557	case IFT_ENC:
558	case IFT_PFLOG:
559	case IFT_PFSYNC:
560		return;
561	}
562
563	/*
564	 * if link mtu is too small, don't try to configure IPv6.
565	 * remember there could be some link-layer that has special
566	 * fragmentation logic.
567	 */
568	if (ifp->if_mtu < IPV6_MMTU) {
569		nd6log((LOG_INFO, "in6_ifattach: "
570		    "%s has too small MTU, IPv6 not enabled\n",
571		    ifp->if_xname));
572		return;
573	}
574
575	/*
576	 * usually, we require multicast capability to the interface
577	 */
578	if ((ifp->if_flags & IFF_MULTICAST) == 0) {
579		nd6log((LOG_INFO, "in6_ifattach: "
580		    "%s is not multicast capable, IPv6 not enabled\n",
581		    ifp->if_xname));
582		return;
583	}
584
585	/*
586	 * assign loopback address for loopback interface.
587	 * XXX multiple loopback interface case.
588	 */
589	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
590		in6 = in6addr_loopback;
591		if (in6ifa_ifpwithaddr(ifp, &in6) == NULL) {
592			if (in6_ifattach_loopback(ifp) != 0)
593				return;
594		}
595	}
596
597	/*
598	 * assign a link-local address, if there's none.
599	 */
600	if (ip6_auto_linklocal) {
601		ia6 = in6ifa_ifpforlinklocal(ifp, 0);
602		if (ia6 == NULL) {
603			if (in6_ifattach_linklocal(ifp, NULL) == 0) {
604				/* linklocal address assigned */
605			} else {
606				/* failed to assign linklocal address. bark? */
607			}
608		}
609	}
610}
611
612/*
613 * NOTE: in6_ifdetach() does not support loopback if at this moment.
614 */
615void
616in6_ifdetach(struct ifnet *ifp)
617{
618	struct ifaddr *ifa, *next;
619	struct rtentry *rt;
620	struct sockaddr_in6 sin6;
621
622#ifdef MROUTING
623	/* remove ip6_mrouter stuff */
624	ip6_mrouter_detach(ifp);
625#endif
626
627	/* remove neighbor management table */
628	nd6_purge(ifp);
629
630	/* nuke any of IPv6 addresses we have */
631	TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrlist, ifa_list, next) {
632		if (ifa->ifa_addr->sa_family != AF_INET6)
633			continue;
634		in6_purgeaddr(ifa);
635		dohooks(ifp->if_addrhooks, 0);
636	}
637
638	/*
639	 * remove neighbor management table.  we call it twice just to make
640	 * sure we nuke everything.  maybe we need just one call.
641	 * XXX: since the first call did not release addresses, some prefixes
642	 * might remain.  We should call nd6_purge() again to release the
643	 * prefixes after removing all addresses above.
644	 * (Or can we just delay calling nd6_purge until at this point?)
645	 */
646	nd6_purge(ifp);
647
648	/* remove route to interface local allnodes multicast (ff01::1) */
649	bzero(&sin6, sizeof(sin6));
650	sin6.sin6_len = sizeof(struct sockaddr_in6);
651	sin6.sin6_family = AF_INET6;
652	sin6.sin6_addr = in6addr_intfacelocal_allnodes;
653	sin6.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
654	rt = rtalloc(sin6tosa(&sin6), 0, ifp->if_rdomain);
655	if (rt && rt->rt_ifp == ifp) {
656		struct rt_addrinfo info;
657
658		bzero(&info, sizeof(info));
659		info.rti_flags = rt->rt_flags;
660		info.rti_info[RTAX_DST] = rt_key(rt);
661		info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
662		info.rti_info[RTAX_NETMASK] = rt_mask(rt);
663		rtrequest1(RTM_DELETE, &info, rt->rt_priority, NULL,
664		    ifp->if_rdomain);
665		rtfree(rt);
666	}
667
668	/* remove route to link-local allnodes multicast (ff02::1) */
669	bzero(&sin6, sizeof(sin6));
670	sin6.sin6_len = sizeof(struct sockaddr_in6);
671	sin6.sin6_family = AF_INET6;
672	sin6.sin6_addr = in6addr_linklocal_allnodes;
673	sin6.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
674	rt = rtalloc(sin6tosa(&sin6), 0, ifp->if_rdomain);
675	if (rt && rt->rt_ifp == ifp) {
676		struct rt_addrinfo info;
677
678		bzero(&info, sizeof(info));
679		info.rti_flags = rt->rt_flags;
680		info.rti_info[RTAX_DST] = rt_key(rt);
681		info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
682		info.rti_info[RTAX_NETMASK] = rt_mask(rt);
683		rtrequest1(RTM_DELETE, &info, rt->rt_priority, NULL,
684		    ifp->if_rdomain);
685		rtfree(rt);
686	}
687
688	if (ifp->if_xflags & IFXF_AUTOCONF6) {
689		nd6_rs_timeout_count--;
690		if (nd6_rs_timeout_count == 0)
691			timeout_del(&nd6_rs_output_timer);
692		if (RS_LHCOOKIE(ifp) != NULL)
693			hook_disestablish(ifp->if_linkstatehooks,
694			    RS_LHCOOKIE(ifp));
695	}
696}
697