xref: /freebsd/sys/netinet6/in6_ifattach.c (revision f9218d3d4fd34f082473b3a021c6d4d109fb47cf)
1 /*	$FreeBSD$	*/
2 /*	$KAME: in6_ifattach.c,v 1.118 2001/05/24 07:44:00 itojun 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/malloc.h>
36 #include <sys/socket.h>
37 #include <sys/sockio.h>
38 #include <sys/kernel.h>
39 #include <sys/syslog.h>
40 #include <sys/md5.h>
41 
42 #include <net/if.h>
43 #include <net/if_dl.h>
44 #include <net/if_types.h>
45 #include <net/route.h>
46 
47 #include <netinet/in.h>
48 #include <netinet/in_var.h>
49 #include <netinet/if_ether.h>
50 #include <netinet/in_pcb.h>
51 
52 #include <netinet/ip6.h>
53 #include <netinet6/ip6_var.h>
54 #include <netinet6/in6_var.h>
55 #include <netinet6/in6_pcb.h>
56 #include <netinet6/in6_ifattach.h>
57 #include <netinet6/ip6_var.h>
58 #include <netinet6/nd6.h>
59 #include <netinet6/scope6_var.h>
60 
61 #include <net/net_osdep.h>
62 
63 struct in6_ifstat **in6_ifstat = NULL;
64 struct icmp6_ifstat **icmp6_ifstat = NULL;
65 size_t in6_ifstatmax = 0;
66 size_t icmp6_ifstatmax = 0;
67 unsigned long in6_maxmtu = 0;
68 
69 #ifdef IP6_AUTO_LINKLOCAL
70 int ip6_auto_linklocal = IP6_AUTO_LINKLOCAL;
71 #else
72 int ip6_auto_linklocal = 1;	/* enable by default */
73 #endif
74 
75 struct callout in6_tmpaddrtimer_ch;
76 
77 extern struct inpcbinfo udbinfo;
78 extern struct inpcbinfo ripcbinfo;
79 
80 static int get_rand_ifid __P((struct ifnet *, struct in6_addr *));
81 static int generate_tmp_ifid __P((u_int8_t *, const u_int8_t *, u_int8_t *));
82 static int get_hw_ifid __P((struct ifnet *, struct in6_addr *));
83 static int get_ifid __P((struct ifnet *, struct ifnet *, struct in6_addr *));
84 static int in6_ifattach_linklocal __P((struct ifnet *, struct ifnet *));
85 static int in6_ifattach_loopback __P((struct ifnet *));
86 
87 #define EUI64_GBIT	0x01
88 #define EUI64_UBIT	0x02
89 #define EUI64_TO_IFID(in6)	do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (0)
90 #define EUI64_GROUP(in6)	((in6)->s6_addr[8] & EUI64_GBIT)
91 #define EUI64_INDIVIDUAL(in6)	(!EUI64_GROUP(in6))
92 #define EUI64_LOCAL(in6)	((in6)->s6_addr[8] & EUI64_UBIT)
93 #define EUI64_UNIVERSAL(in6)	(!EUI64_LOCAL(in6))
94 
95 #define IFID_LOCAL(in6)		(!EUI64_LOCAL(in6))
96 #define IFID_UNIVERSAL(in6)	(!EUI64_UNIVERSAL(in6))
97 
98 /*
99  * Generate a last-resort interface identifier, when the machine has no
100  * IEEE802/EUI64 address sources.
101  * The goal here is to get an interface identifier that is
102  * (1) random enough and (2) does not change across reboot.
103  * We currently use MD5(hostname) for it.
104  */
105 static int
106 get_rand_ifid(ifp, in6)
107 	struct ifnet *ifp;
108 	struct in6_addr *in6;	/* upper 64bits are preserved */
109 {
110 	MD5_CTX ctxt;
111 	u_int8_t digest[16];
112 	int hostnamelen	= strlen(hostname);
113 
114 #if 0
115 	/* we need at least several letters as seed for ifid */
116 	if (hostnamelen < 3)
117 		return -1;
118 #endif
119 
120 	/* generate 8 bytes of pseudo-random value. */
121 	bzero(&ctxt, sizeof(ctxt));
122 	MD5Init(&ctxt);
123 	MD5Update(&ctxt, hostname, hostnamelen);
124 	MD5Final(digest, &ctxt);
125 
126 	/* assumes sizeof(digest) > sizeof(ifid) */
127 	bcopy(digest, &in6->s6_addr[8], 8);
128 
129 	/* make sure to set "u" bit to local, and "g" bit to individual. */
130 	in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
131 	in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
132 
133 	/* convert EUI64 into IPv6 interface identifier */
134 	EUI64_TO_IFID(in6);
135 
136 	return 0;
137 }
138 
139 static int
140 generate_tmp_ifid(seed0, seed1, ret)
141 	u_int8_t *seed0, *ret;
142 	const u_int8_t *seed1;
143 {
144 	MD5_CTX ctxt;
145 	u_int8_t seed[16], digest[16], nullbuf[8];
146 	u_int32_t val32;
147 	struct timeval tv;
148 
149 	/* If there's no hisotry, start with a random seed. */
150 	bzero(nullbuf, sizeof(nullbuf));
151 	if (bcmp(nullbuf, seed0, sizeof(nullbuf)) == 0) {
152 		int i;
153 
154 		for (i = 0; i < 2; i++) {
155 			microtime(&tv);
156 			val32 = random() ^ tv.tv_usec;
157 			bcopy(&val32, seed + sizeof(val32) * i, sizeof(val32));
158 		}
159 	} else {
160 		bcopy(seed0, seed, 8);
161 	}
162 
163 	/* copy the right-most 64-bits of the given address */
164 	/* XXX assumption on the size of IFID */
165 	bcopy(seed1, &seed[8], 8);
166 
167 	if (0) {		/* for debugging purposes only */
168 		int i;
169 
170 		printf("generate_tmp_ifid: new randomized ID from: ");
171 		for (i = 0; i < 16; i++)
172 			printf("%02x", seed[i]);
173 		printf(" ");
174 	}
175 
176 	/* generate 16 bytes of pseudo-random value. */
177 	bzero(&ctxt, sizeof(ctxt));
178 	MD5Init(&ctxt);
179 	MD5Update(&ctxt, seed, sizeof(seed));
180 	MD5Final(digest, &ctxt);
181 
182 	/*
183 	 * RFC 3041 3.2.1. (3)
184 	 * Take the left-most 64-bits of the MD5 digest and set bit 6 (the
185 	 * left-most bit is numbered 0) to zero.
186 	 */
187 	bcopy(digest, ret, 8);
188 	ret[0] &= ~EUI64_UBIT;
189 
190 	/*
191 	 * XXX: we'd like to ensure that the generated value is not zero
192 	 * for simplicity.  If the caclculated digest happens to be zero,
193 	 * use a random non-zero value as the last resort.
194 	 */
195 	if (bcmp(nullbuf, ret, sizeof(nullbuf)) == 0) {
196 		log(LOG_INFO,
197 		    "generate_tmp_ifid: computed MD5 value is zero.\n");
198 
199 		microtime(&tv);
200 		val32 = random() ^ tv.tv_usec;
201 		val32 = 1 + (val32 % (0xffffffff - 1));
202 	}
203 
204 	/*
205 	 * RFC 3041 3.2.1. (4)
206 	 * Take the rightmost 64-bits of the MD5 digest and save them in
207 	 * stable storage as the history value to be used in the next
208 	 * iteration of the algorithm.
209 	 */
210 	bcopy(&digest[8], seed0, 8);
211 
212 	if (0) {		/* for debugging purposes only */
213 		int i;
214 
215 		printf("to: ");
216 		for (i = 0; i < 16; i++)
217 			printf("%02x", digest[i]);
218 		printf("\n");
219 	}
220 
221 	return 0;
222 }
223 
224 /*
225  * Get interface identifier for the specified interface.
226  * XXX assumes single sockaddr_dl (AF_LINK address) per an interface
227  */
228 static int
229 get_hw_ifid(ifp, in6)
230 	struct ifnet *ifp;
231 	struct in6_addr *in6;	/* upper 64bits are preserved */
232 {
233 	struct ifaddr *ifa;
234 	struct sockaddr_dl *sdl;
235 	u_int8_t *addr;
236 	size_t addrlen;
237 	static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
238 	static u_int8_t allone[8] =
239 		{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
240 
241 	for (ifa = ifp->if_addrlist.tqh_first;
242 	     ifa;
243 	     ifa = ifa->ifa_list.tqe_next)
244 	{
245 		if (ifa->ifa_addr->sa_family != AF_LINK)
246 			continue;
247 		sdl = (struct sockaddr_dl *)ifa->ifa_addr;
248 		if (sdl == NULL)
249 			continue;
250 		if (sdl->sdl_alen == 0)
251 			continue;
252 
253 		goto found;
254 	}
255 
256 	return -1;
257 
258 found:
259 	addr = LLADDR(sdl);
260 	addrlen = sdl->sdl_alen;
261 
262 	/* get EUI64 */
263 	switch (ifp->if_type) {
264 	case IFT_ETHER:
265 	case IFT_FDDI:
266 	case IFT_ATM:
267 	case IFT_IEEE1394:
268 #ifdef IFT_IEEE80211
269 	case IFT_IEEE80211:
270 #endif
271 		/* IEEE802/EUI64 cases - what others? */
272 		/* IEEE1394 uses 16byte length address starting with EUI64 */
273 		if (addrlen > 8)
274 			addrlen = 8;
275 
276 		/* look at IEEE802/EUI64 only */
277 		if (addrlen != 8 && addrlen != 6)
278 			return -1;
279 
280 		/*
281 		 * check for invalid MAC address - on bsdi, we see it a lot
282 		 * since wildboar configures all-zero MAC on pccard before
283 		 * card insertion.
284 		 */
285 		if (bcmp(addr, allzero, addrlen) == 0)
286 			return -1;
287 		if (bcmp(addr, allone, addrlen) == 0)
288 			return -1;
289 
290 		/* make EUI64 address */
291 		if (addrlen == 8)
292 			bcopy(addr, &in6->s6_addr[8], 8);
293 		else if (addrlen == 6) {
294 			in6->s6_addr[8] = addr[0];
295 			in6->s6_addr[9] = addr[1];
296 			in6->s6_addr[10] = addr[2];
297 			in6->s6_addr[11] = 0xff;
298 			in6->s6_addr[12] = 0xfe;
299 			in6->s6_addr[13] = addr[3];
300 			in6->s6_addr[14] = addr[4];
301 			in6->s6_addr[15] = addr[5];
302 		}
303 		break;
304 
305 	case IFT_ARCNET:
306 		if (addrlen != 1)
307 			return -1;
308 		if (!addr[0])
309 			return -1;
310 
311 		bzero(&in6->s6_addr[8], 8);
312 		in6->s6_addr[15] = addr[0];
313 
314 		/*
315 		 * due to insufficient bitwidth, we mark it local.
316 		 */
317 		in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
318 		in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
319 		break;
320 
321 	case IFT_GIF:
322 #ifdef IFT_STF
323 	case IFT_STF:
324 #endif
325 		/*
326 		 * RFC2893 says: "SHOULD use IPv4 address as ifid source".
327 		 * however, IPv4 address is not very suitable as unique
328 		 * identifier source (can be renumbered).
329 		 * we don't do this.
330 		 */
331 		return -1;
332 
333 	default:
334 		return -1;
335 	}
336 
337 	/* sanity check: g bit must not indicate "group" */
338 	if (EUI64_GROUP(in6))
339 		return -1;
340 
341 	/* convert EUI64 into IPv6 interface identifier */
342 	EUI64_TO_IFID(in6);
343 
344 	/*
345 	 * sanity check: ifid must not be all zero, avoid conflict with
346 	 * subnet router anycast
347 	 */
348 	if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
349 	    bcmp(&in6->s6_addr[9], allzero, 7) == 0) {
350 		return -1;
351 	}
352 
353 	return 0;
354 }
355 
356 /*
357  * Get interface identifier for the specified interface.  If it is not
358  * available on ifp0, borrow interface identifier from other information
359  * sources.
360  */
361 static int
362 get_ifid(ifp0, altifp, in6)
363 	struct ifnet *ifp0;
364 	struct ifnet *altifp;	/* secondary EUI64 source */
365 	struct in6_addr *in6;
366 {
367 	struct ifnet *ifp;
368 
369 	/* first, try to get it from the interface itself */
370 	if (get_hw_ifid(ifp0, in6) == 0) {
371 		nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n",
372 		    if_name(ifp0)));
373 		goto success;
374 	}
375 
376 	/* try secondary EUI64 source. this basically is for ATM PVC */
377 	if (altifp && get_hw_ifid(altifp, in6) == 0) {
378 		nd6log((LOG_DEBUG, "%s: got interface identifier from %s\n",
379 		    if_name(ifp0), if_name(altifp)));
380 		goto success;
381 	}
382 
383 	/* next, try to get it from some other hardware interface */
384 	IFNET_RLOCK();
385 	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_list.tqe_next)
386 	{
387 		if (ifp == ifp0)
388 			continue;
389 		if (get_hw_ifid(ifp, in6) != 0)
390 			continue;
391 
392 		/*
393 		 * to borrow ifid from other interface, ifid needs to be
394 		 * globally unique
395 		 */
396 		if (IFID_UNIVERSAL(in6)) {
397 			nd6log((LOG_DEBUG,
398 			    "%s: borrow interface identifier from %s\n",
399 			    if_name(ifp0), if_name(ifp)));
400 			IFNET_RUNLOCK();
401 			goto success;
402 		}
403 	}
404 	IFNET_RUNLOCK();
405 
406 	/* last resort: get from random number source */
407 	if (get_rand_ifid(ifp, in6) == 0) {
408 		nd6log((LOG_DEBUG,
409 		    "%s: interface identifier generated by random number\n",
410 		    if_name(ifp0)));
411 		goto success;
412 	}
413 
414 	printf("%s: failed to get interface identifier\n", if_name(ifp0));
415 	return -1;
416 
417 success:
418 	nd6log((LOG_INFO, "%s: ifid: "
419 		"%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
420 		if_name(ifp0),
421 		in6->s6_addr[8], in6->s6_addr[9],
422 		in6->s6_addr[10], in6->s6_addr[11],
423 		in6->s6_addr[12], in6->s6_addr[13],
424 		in6->s6_addr[14], in6->s6_addr[15]));
425 	return 0;
426 }
427 
428 static int
429 in6_ifattach_linklocal(ifp, altifp)
430 	struct ifnet *ifp;
431 	struct ifnet *altifp;	/* secondary EUI64 source */
432 {
433 	struct in6_ifaddr *ia;
434 	struct in6_aliasreq ifra;
435 	struct nd_prefix pr0;
436 	int i, error;
437 
438 	/*
439 	 * configure link-local address.
440 	 */
441 	bzero(&ifra, sizeof(ifra));
442 
443 	/*
444 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
445 	 * for safety.
446 	 */
447 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
448 
449 	ifra.ifra_addr.sin6_family = AF_INET6;
450 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
451 	ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80);
452 #ifdef SCOPEDROUTING
453 	ifra.ifra_addr.sin6_addr.s6_addr16[1] = 0
454 #else
455 	ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index); /* XXX */
456 #endif
457 	ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
458 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
459 		ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
460 		ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
461 	} else {
462 		if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) {
463 			nd6log((LOG_ERR,
464 			    "%s: no ifid available\n", if_name(ifp)));
465 			return -1;
466 		}
467 	}
468 #ifdef SCOPEDROUTING
469 	ifra.ifra_addr.sin6_scope_id =
470 		in6_addr2scopeid(ifp,  &ifra.ifra_addr.sin6_addr);
471 #endif
472 
473 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
474 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
475 	ifra.ifra_prefixmask.sin6_addr = in6mask64;
476 #ifdef SCOPEDROUTING
477 	/* take into accound the sin6_scope_id field for routing */
478 	ifra.ifra_prefixmask.sin6_scope_id = 0xffffffff;
479 #endif
480 	/* link-local addresses should NEVER expire. */
481 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
482 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
483 
484 	/*
485 	 * Do not let in6_update_ifa() do DAD, since we need a random delay
486 	 * before sending an NS at the first time the interface becomes up.
487 	 * Instead, in6_if_up() will start DAD with a proper random delay.
488 	 */
489 	ifra.ifra_flags |= IN6_IFF_NODAD;
490 
491 	/*
492 	 * Now call in6_update_ifa() to do a bunch of procedures to configure
493 	 * a link-local address. We can set NULL to the 3rd argument, because
494 	 * we know there's no other link-local address on the interface
495 	 * and therefore we are adding one (instead of updating one).
496 	 */
497 	if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0) {
498 		/*
499 		 * XXX: When the interface does not support IPv6, this call
500 		 * would fail in the SIOCSIFADDR ioctl.  I believe the
501 		 * notification is rather confusing in this case, so just
502 		 * supress it.  (jinmei@kame.net 20010130)
503 		 */
504 		if (error != EAFNOSUPPORT)
505 			log(LOG_NOTICE, "in6_ifattach_linklocal: failed to "
506 			    "configure a link-local address on %s "
507 			    "(errno=%d)\n",
508 			    if_name(ifp), error);
509 		return(-1);
510 	}
511 
512 	/*
513 	 * Adjust ia6_flags so that in6_if_up will perform DAD.
514 	 * XXX: Some P2P interfaces seem not to send packets just after
515 	 * becoming up, so we skip p2p interfaces for safety.
516 	 */
517 	ia = in6ifa_ifpforlinklocal(ifp, 0); /* ia must not be NULL */
518 #ifdef DIAGNOSTIC
519 	if (!ia) {
520 		panic("ia == NULL in in6_ifattach_linklocal");
521 		/* NOTREACHED */
522 	}
523 #endif
524 	if (in6if_do_dad(ifp) && (ifp->if_flags & IFF_POINTOPOINT) == 0) {
525 		ia->ia6_flags &= ~IN6_IFF_NODAD;
526 		ia->ia6_flags |= IN6_IFF_TENTATIVE;
527 	}
528 
529 	/*
530 	 * Make the link-local prefix (fe80::/64%link) as on-link.
531 	 * Since we'd like to manage prefixes separately from addresses,
532 	 * we make an ND6 prefix structure for the link-local prefix,
533 	 * and add it to the prefix list as a never-expire prefix.
534 	 * XXX: this change might affect some existing code base...
535 	 */
536 	bzero(&pr0, sizeof(pr0));
537 	pr0.ndpr_ifp = ifp;
538 	/* this should be 64 at this moment. */
539 	pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
540 	pr0.ndpr_mask = ifra.ifra_prefixmask.sin6_addr;
541 	pr0.ndpr_prefix = ifra.ifra_addr;
542 	/* apply the mask for safety. (nd6_prelist_add will apply it again) */
543 	for (i = 0; i < 4; i++) {
544 		pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
545 			in6mask64.s6_addr32[i];
546 	}
547 	/*
548 	 * Initialize parameters.  The link-local prefix must always be
549 	 * on-link, and its lifetimes never expire.
550 	 */
551 	pr0.ndpr_raf_onlink = 1;
552 	pr0.ndpr_raf_auto = 1;	/* probably meaningless */
553 	pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
554 	pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
555 	/*
556 	 * Since there is no other link-local addresses, nd6_prefix_lookup()
557 	 * probably returns NULL.  However, we cannot always expect the result.
558 	 * For example, if we first remove the (only) existing link-local
559 	 * address, and then reconfigure another one, the prefix is still
560 	 * valid with referring to the old link-local address.
561 	 */
562 	if (nd6_prefix_lookup(&pr0) == NULL) {
563 		if ((error = nd6_prelist_add(&pr0, NULL, NULL)) != 0)
564 			return(error);
565 	}
566 
567 	return 0;
568 }
569 
570 static int
571 in6_ifattach_loopback(ifp)
572 	struct ifnet *ifp;	/* must be IFT_LOOP */
573 {
574 	struct in6_aliasreq ifra;
575 	int error;
576 
577 	bzero(&ifra, sizeof(ifra));
578 
579 	/*
580 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
581 	 * for safety.
582 	 */
583 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
584 
585 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
586 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
587 	ifra.ifra_prefixmask.sin6_addr = in6mask128;
588 
589 	/*
590 	 * Always initialize ia_dstaddr (= broadcast address) to loopback
591 	 * address.  Follows IPv4 practice - see in_ifinit().
592 	 */
593 	ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
594 	ifra.ifra_dstaddr.sin6_family = AF_INET6;
595 	ifra.ifra_dstaddr.sin6_addr = in6addr_loopback;
596 
597 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
598 	ifra.ifra_addr.sin6_family = AF_INET6;
599 	ifra.ifra_addr.sin6_addr = in6addr_loopback;
600 
601 	/* the loopback  address should NEVER expire. */
602 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
603 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
604 
605 	/* we don't need to perform DAD on loopback interfaces. */
606 	ifra.ifra_flags |= IN6_IFF_NODAD;
607 
608 	/* skip registration to the prefix list. XXX should be temporary. */
609 	ifra.ifra_flags |= IN6_IFF_NOPFX;
610 
611 	/*
612 	 * We are sure that this is a newly assigned address, so we can set
613 	 * NULL to the 3rd arg.
614 	 */
615 	if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0) {
616 		log(LOG_ERR, "in6_ifattach_loopback: failed to configure "
617 		    "the loopback address on %s (errno=%d)\n",
618 		    if_name(ifp), error);
619 		return(-1);
620 	}
621 
622 	return 0;
623 }
624 
625 /*
626  * compute NI group address, based on the current hostname setting.
627  * see draft-ietf-ipngwg-icmp-name-lookup-* (04 and later).
628  *
629  * when ifp == NULL, the caller is responsible for filling scopeid.
630  */
631 int
632 in6_nigroup(ifp, name, namelen, in6)
633 	struct ifnet *ifp;
634 	const char *name;
635 	int namelen;
636 	struct in6_addr *in6;
637 {
638 	const char *p;
639 	u_char *q;
640 	MD5_CTX ctxt;
641 	u_int8_t digest[16];
642 	char l;
643 	char n[64];	/* a single label must not exceed 63 chars */
644 
645 	if (!namelen || !name)
646 		return -1;
647 
648 	p = name;
649 	while (p && *p && *p != '.' && p - name < namelen)
650 		p++;
651 	if (p - name > sizeof(n) - 1)
652 		return -1;	/* label too long */
653 	l = p - name;
654 	strncpy(n, name, l);
655 	n[(int)l] = '\0';
656 	for (q = n; *q; q++) {
657 		if ('A' <= *q && *q <= 'Z')
658 			*q = *q - 'A' + 'a';
659 	}
660 
661 	/* generate 8 bytes of pseudo-random value. */
662 	bzero(&ctxt, sizeof(ctxt));
663 	MD5Init(&ctxt);
664 	MD5Update(&ctxt, &l, sizeof(l));
665 	MD5Update(&ctxt, n, l);
666 	MD5Final(digest, &ctxt);
667 
668 	bzero(in6, sizeof(*in6));
669 	in6->s6_addr16[0] = htons(0xff02);
670 	if (ifp)
671 		in6->s6_addr16[1] = htons(ifp->if_index);
672 	in6->s6_addr8[11] = 2;
673 	bcopy(digest, &in6->s6_addr32[3], sizeof(in6->s6_addr32[3]));
674 
675 	return 0;
676 }
677 
678 void
679 in6_nigroup_attach(name, namelen)
680 	const char *name;
681 	int namelen;
682 {
683 	struct ifnet *ifp;
684 	struct sockaddr_in6 mltaddr;
685 	struct in6_multi *in6m;
686 	int error;
687 
688 	bzero(&mltaddr, sizeof(mltaddr));
689 	mltaddr.sin6_family = AF_INET6;
690 	mltaddr.sin6_len = sizeof(struct sockaddr_in6);
691 	if (in6_nigroup(NULL, name, namelen, &mltaddr.sin6_addr) != 0)
692 		return;
693 
694 	IFNET_RLOCK();
695 	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_list.tqe_next)
696 	{
697 		mltaddr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
698 		IN6_LOOKUP_MULTI(mltaddr.sin6_addr, ifp, in6m);
699 		if (!in6m) {
700 			if (!in6_addmulti(&mltaddr.sin6_addr, ifp, &error)) {
701 				nd6log((LOG_ERR, "%s: failed to join %s "
702 				    "(errno=%d)\n", if_name(ifp),
703 				    ip6_sprintf(&mltaddr.sin6_addr),
704 				    error));
705 			}
706 		}
707 	}
708 	IFNET_RUNLOCK();
709 }
710 
711 void
712 in6_nigroup_detach(name, namelen)
713 	const char *name;
714 	int namelen;
715 {
716 	struct ifnet *ifp;
717 	struct sockaddr_in6 mltaddr;
718 	struct in6_multi *in6m;
719 
720 	bzero(&mltaddr, sizeof(mltaddr));
721 	mltaddr.sin6_family = AF_INET6;
722 	mltaddr.sin6_len = sizeof(struct sockaddr_in6);
723 	if (in6_nigroup(NULL, name, namelen, &mltaddr.sin6_addr) != 0)
724 		return;
725 
726 	IFNET_RLOCK();
727 	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_list.tqe_next)
728 	{
729 		mltaddr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
730 		IN6_LOOKUP_MULTI(mltaddr.sin6_addr, ifp, in6m);
731 		if (in6m)
732 			in6_delmulti(in6m);
733 	}
734 	IFNET_RUNLOCK();
735 }
736 
737 /*
738  * XXX multiple loopback interface needs more care.  for instance,
739  * nodelocal address needs to be configured onto only one of them.
740  * XXX multiple link-local address case
741  */
742 void
743 in6_ifattach(ifp, altifp)
744 	struct ifnet *ifp;
745 	struct ifnet *altifp;	/* secondary EUI64 source */
746 {
747 	static size_t if_indexlim = 8;
748 	struct in6_ifaddr *ia;
749 	struct in6_addr in6;
750 
751 	/* some of the interfaces are inherently not IPv6 capable */
752 	switch (ifp->if_type) {
753 #ifdef IFT_BRIDGE	/*OpenBSD 2.8*/
754 	case IFT_BRIDGE:
755 		return;
756 #endif
757 	}
758 
759 	/*
760 	 * We have some arrays that should be indexed by if_index.
761 	 * since if_index will grow dynamically, they should grow too.
762 	 *	struct in6_ifstat **in6_ifstat
763 	 *	struct icmp6_ifstat **icmp6_ifstat
764 	 */
765 	if (in6_ifstat == NULL || icmp6_ifstat == NULL ||
766 	    if_index >= if_indexlim) {
767 		size_t n;
768 		caddr_t q;
769 		size_t olim;
770 
771 		olim = if_indexlim;
772 		while (if_index >= if_indexlim)
773 			if_indexlim <<= 1;
774 
775 		/* grow in6_ifstat */
776 		n = if_indexlim * sizeof(struct in6_ifstat *);
777 		q = (caddr_t)malloc(n, M_IFADDR, M_WAITOK);
778 		bzero(q, n);
779 		if (in6_ifstat) {
780 			bcopy((caddr_t)in6_ifstat, q,
781 				olim * sizeof(struct in6_ifstat *));
782 			free((caddr_t)in6_ifstat, M_IFADDR);
783 		}
784 		in6_ifstat = (struct in6_ifstat **)q;
785 		in6_ifstatmax = if_indexlim;
786 
787 		/* grow icmp6_ifstat */
788 		n = if_indexlim * sizeof(struct icmp6_ifstat *);
789 		q = (caddr_t)malloc(n, M_IFADDR, M_WAITOK);
790 		bzero(q, n);
791 		if (icmp6_ifstat) {
792 			bcopy((caddr_t)icmp6_ifstat, q,
793 				olim * sizeof(struct icmp6_ifstat *));
794 			free((caddr_t)icmp6_ifstat, M_IFADDR);
795 		}
796 		icmp6_ifstat = (struct icmp6_ifstat **)q;
797 		icmp6_ifstatmax = if_indexlim;
798 	}
799 
800 	/* initialize scope identifiers */
801 	scope6_ifattach(ifp);
802 
803 	/*
804 	 * quirks based on interface type
805 	 */
806 	switch (ifp->if_type) {
807 #ifdef IFT_STF
808 	case IFT_STF:
809 		/*
810 		 * 6to4 interface is a very special kind of beast.
811 		 * no multicast, no linklocal.  RFC2529 specifies how to make
812 		 * linklocals for 6to4 interface, but there's no use and
813 		 * it is rather harmful to have one.
814 		 */
815 		goto statinit;
816 #endif
817 	default:
818 		break;
819 	}
820 
821 	/*
822 	 * usually, we require multicast capability to the interface
823 	 */
824 	if ((ifp->if_flags & IFF_MULTICAST) == 0) {
825 		log(LOG_INFO, "in6_ifattach: "
826 		    "%s is not multicast capable, IPv6 not enabled\n",
827 		    if_name(ifp));
828 		return;
829 	}
830 
831 	/*
832 	 * assign loopback address for loopback interface.
833 	 * XXX multiple loopback interface case.
834 	 */
835 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
836 		in6 = in6addr_loopback;
837 		if (in6ifa_ifpwithaddr(ifp, &in6) == NULL) {
838 			if (in6_ifattach_loopback(ifp) != 0)
839 				return;
840 		}
841 	}
842 
843 	/*
844 	 * assign a link-local address, if there's none.
845 	 */
846 	if (ip6_auto_linklocal) {
847 		ia = in6ifa_ifpforlinklocal(ifp, 0);
848 		if (ia == NULL) {
849 			if (in6_ifattach_linklocal(ifp, altifp) == 0) {
850 				/* linklocal address assigned */
851 			} else {
852 				/* failed to assign linklocal address. bark? */
853 			}
854 		}
855 	}
856 
857 #ifdef IFT_STF			/* XXX */
858 statinit:
859 #endif
860 
861 	/* update dynamically. */
862 	if (in6_maxmtu < ifp->if_mtu)
863 		in6_maxmtu = ifp->if_mtu;
864 
865 	if (in6_ifstat[ifp->if_index] == NULL) {
866 		in6_ifstat[ifp->if_index] = (struct in6_ifstat *)
867 			malloc(sizeof(struct in6_ifstat), M_IFADDR, M_WAITOK);
868 		bzero(in6_ifstat[ifp->if_index], sizeof(struct in6_ifstat));
869 	}
870 	if (icmp6_ifstat[ifp->if_index] == NULL) {
871 		icmp6_ifstat[ifp->if_index] = (struct icmp6_ifstat *)
872 			malloc(sizeof(struct icmp6_ifstat), M_IFADDR, M_WAITOK);
873 		bzero(icmp6_ifstat[ifp->if_index], sizeof(struct icmp6_ifstat));
874 	}
875 
876 	/* initialize NDP variables */
877 	nd6_ifattach(ifp);
878 }
879 
880 /*
881  * NOTE: in6_ifdetach() does not support loopback if at this moment.
882  * We don't need this function in bsdi, because interfaces are never removed
883  * from the ifnet list in bsdi.
884  */
885 void
886 in6_ifdetach(ifp)
887 	struct ifnet *ifp;
888 {
889 	struct in6_ifaddr *ia, *oia;
890 	struct ifaddr *ifa, *next;
891 	struct rtentry *rt;
892 	short rtflags;
893 	struct sockaddr_in6 sin6;
894 	struct in6_multi *in6m;
895 	struct in6_multi *in6m_next;
896 
897 	/* nuke prefix list.  this may try to remove some of ifaddrs as well */
898 	in6_purgeprefix(ifp);
899 
900 	/* remove neighbor management table */
901 	nd6_purge(ifp);
902 
903 	/* nuke any of IPv6 addresses we have */
904 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = next)
905 	{
906 		next = ifa->ifa_list.tqe_next;
907 		if (ifa->ifa_addr->sa_family != AF_INET6)
908 			continue;
909 		in6_purgeaddr(ifa);
910 	}
911 
912 	/* undo everything done by in6_ifattach(), just in case */
913 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = next)
914 	{
915 		next = ifa->ifa_list.tqe_next;
916 
917 
918 		if (ifa->ifa_addr->sa_family != AF_INET6
919 		 || !IN6_IS_ADDR_LINKLOCAL(&satosin6(&ifa->ifa_addr)->sin6_addr)) {
920 			continue;
921 		}
922 
923 		ia = (struct in6_ifaddr *)ifa;
924 
925 		/* remove from the routing table */
926 		if ((ia->ia_flags & IFA_ROUTE)
927 		 && (rt = rtalloc1((struct sockaddr *)&ia->ia_addr, 0, 0UL))) {
928 			rtflags = rt->rt_flags;
929 			rtfree(rt);
930 			rtrequest(RTM_DELETE,
931 				(struct sockaddr *)&ia->ia_addr,
932 				(struct sockaddr *)&ia->ia_addr,
933 				(struct sockaddr *)&ia->ia_prefixmask,
934 				rtflags, (struct rtentry **)0);
935 		}
936 
937 		/* remove from the linked list */
938 		TAILQ_REMOVE(&ifp->if_addrlist, (struct ifaddr *)ia, ifa_list);
939 		IFAFREE(&ia->ia_ifa);
940 
941 		/* also remove from the IPv6 address chain(itojun&jinmei) */
942 		oia = ia;
943 		if (oia == (ia = in6_ifaddr))
944 			in6_ifaddr = ia->ia_next;
945 		else {
946 			while (ia->ia_next && (ia->ia_next != oia))
947 				ia = ia->ia_next;
948 			if (ia->ia_next)
949 				ia->ia_next = oia->ia_next;
950 			else {
951 				nd6log((LOG_ERR,
952 				    "%s: didn't unlink in6ifaddr from "
953 				    "list\n", if_name(ifp)));
954 			}
955 		}
956 
957 		IFAFREE(&oia->ia_ifa);
958 	}
959 
960 	/* leave from all multicast groups joined */
961 	in6_pcbpurgeif0(LIST_FIRST(udbinfo.listhead), ifp);
962 	in6_pcbpurgeif0(LIST_FIRST(ripcbinfo.listhead), ifp);
963 	for (in6m = LIST_FIRST(&in6_multihead); in6m; in6m = in6m_next) {
964 		in6m_next = LIST_NEXT(in6m, in6m_entry);
965 		if (in6m->in6m_ifp != ifp)
966 			continue;
967 		in6_delmulti(in6m);
968 		in6m = NULL;
969 	}
970 
971 	/*
972 	 * remove neighbor management table.  we call it twice just to make
973 	 * sure we nuke everything.  maybe we need just one call.
974 	 * XXX: since the first call did not release addresses, some prefixes
975 	 * might remain.  We should call nd6_purge() again to release the
976 	 * prefixes after removing all addresses above.
977 	 * (Or can we just delay calling nd6_purge until at this point?)
978 	 */
979 	nd6_purge(ifp);
980 
981 	/* remove route to link-local allnodes multicast (ff02::1) */
982 	bzero(&sin6, sizeof(sin6));
983 	sin6.sin6_len = sizeof(struct sockaddr_in6);
984 	sin6.sin6_family = AF_INET6;
985 	sin6.sin6_addr = in6addr_linklocal_allnodes;
986 	sin6.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
987 	rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
988 	if (rt && rt->rt_ifp == ifp) {
989 		rtrequest(RTM_DELETE, (struct sockaddr *)rt_key(rt),
990 			rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
991 		rtfree(rt);
992 	}
993 }
994 
995 void
996 in6_get_tmpifid(ifp, retbuf, baseid, generate)
997 	struct ifnet *ifp;
998 	u_int8_t *retbuf;
999 	const u_int8_t *baseid;
1000 	int generate;
1001 {
1002 	u_int8_t nullbuf[8];
1003 	struct nd_ifinfo *ndi = &nd_ifinfo[ifp->if_index];
1004 
1005 	bzero(nullbuf, sizeof(nullbuf));
1006 	if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
1007 		/* we've never created a random ID.  Create a new one. */
1008 		generate = 1;
1009 	}
1010 
1011 	if (generate) {
1012 		bcopy(baseid, ndi->randomseed1, sizeof(ndi->randomseed1));
1013 
1014 		/* generate_tmp_ifid will update seedn and buf */
1015 		(void)generate_tmp_ifid(ndi->randomseed0, ndi->randomseed1,
1016 					ndi->randomid);
1017 	}
1018 	bcopy(ndi->randomid, retbuf, 8);
1019 }
1020 
1021 void
1022 in6_tmpaddrtimer(ignored_arg)
1023 	void *ignored_arg;
1024 {
1025 	int i;
1026 	struct nd_ifinfo *ndi;
1027 	u_int8_t nullbuf[8];
1028 	int s = splnet();
1029 
1030 	callout_reset(&in6_tmpaddrtimer_ch,
1031 		      (ip6_temp_preferred_lifetime - ip6_desync_factor -
1032 		       ip6_temp_regen_advance) * hz,
1033 		      in6_tmpaddrtimer, NULL);
1034 
1035 	bzero(nullbuf, sizeof(nullbuf));
1036 	for (i = 1; i < if_index + 1; i++) {
1037 		ndi = &nd_ifinfo[i];
1038 		if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
1039 			/*
1040 			 * We've been generating a random ID on this interface.
1041 			 * Create a new one.
1042 			 */
1043 			(void)generate_tmp_ifid(ndi->randomseed0,
1044 						ndi->randomseed1,
1045 						ndi->randomid);
1046 		}
1047 	}
1048 
1049 	splx(s);
1050 }
1051