xref: /dragonfly/sys/netinet6/in6_ifattach.c (revision 3641b7ca)
1 /*	$FreeBSD: src/sys/netinet6/in6_ifattach.c,v 1.2.2.6 2002/04/28 05:40:26 suz Exp $	*/
2 /*	$DragonFly: src/sys/netinet6/in6_ifattach.c,v 1.22 2008/03/07 11:34:21 sephe Exp $	*/
3 /*	$KAME: in6_ifattach.c,v 1.118 2001/05/24 07:44:00 itojun Exp $	*/
4 
5 /*
6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the project nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/malloc.h>
37 #include <sys/socket.h>
38 #include <sys/sockio.h>
39 #include <sys/kernel.h>
40 #include <sys/syslog.h>
41 #include <sys/md5.h>
42 #include <sys/thread2.h>
43 
44 #include <net/if.h>
45 #include <net/if_dl.h>
46 #include <net/if_types.h>
47 #include <net/route.h>
48 
49 #include <netinet/in.h>
50 #include <netinet/in_var.h>
51 #include <netinet/if_ether.h>
52 #include <netinet/in_pcb.h>
53 
54 #include <netinet/ip6.h>
55 #include <netinet6/ip6_var.h>
56 #include <netinet6/in6_var.h>
57 #include <netinet6/in6_pcb.h>
58 #include <netinet6/in6_ifattach.h>
59 #include <netinet6/ip6_var.h>
60 #include <netinet6/nd6.h>
61 #include <netinet6/scope6_var.h>
62 
63 #include <net/net_osdep.h>
64 
65 unsigned long in6_maxmtu = 0;
66 
67 #ifdef IP6_AUTO_LINKLOCAL
68 int ip6_auto_linklocal = IP6_AUTO_LINKLOCAL;
69 #else
70 int ip6_auto_linklocal = 1;	/* enable by default */
71 #endif
72 
73 struct callout in6_tmpaddrtimer_ch;
74 
75 extern struct inpcbinfo udbinfo;
76 extern struct inpcbinfo ripcbinfo;
77 
78 static int get_rand_ifid (struct ifnet *, struct in6_addr *);
79 static int generate_tmp_ifid (u_int8_t *, const u_int8_t *, u_int8_t *);
80 static int get_hw_ifid (struct ifnet *, struct in6_addr *);
81 static int get_ifid (struct ifnet *, struct ifnet *, struct in6_addr *);
82 static int in6_ifattach_linklocal (struct ifnet *, struct ifnet *);
83 static int in6_ifattach_loopback (struct ifnet *);
84 
85 #define EUI64_GBIT	0x01
86 #define EUI64_UBIT	0x02
87 #define EUI64_TO_IFID(in6)	do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (0)
88 #define EUI64_GROUP(in6)	((in6)->s6_addr[8] & EUI64_GBIT)
89 #define EUI64_INDIVIDUAL(in6)	(!EUI64_GROUP(in6))
90 #define EUI64_LOCAL(in6)	((in6)->s6_addr[8] & EUI64_UBIT)
91 #define EUI64_UNIVERSAL(in6)	(!EUI64_LOCAL(in6))
92 
93 #define IFID_LOCAL(in6)		(!EUI64_LOCAL(in6))
94 #define IFID_UNIVERSAL(in6)	(!EUI64_UNIVERSAL(in6))
95 
96 /*
97  * Generate a last-resort interface identifier, when the machine has no
98  * IEEE802/EUI64 address sources.
99  * The goal here is to get an interface identifier that is
100  * (1) random enough and (2) does not change across reboot.
101  * We currently use MD5(hostname) for it.
102  */
103 static int
104 get_rand_ifid(struct ifnet *ifp,
105 	      struct in6_addr *in6)	/* upper 64bits are preserved */
106 {
107 	MD5_CTX ctxt;
108 	u_int8_t digest[16];
109 	int hostnamelen	= strlen(hostname);
110 
111 #if 0
112 	/* we need at least several letters as seed for ifid */
113 	if (hostnamelen < 3)
114 		return -1;
115 #endif
116 
117 	/* generate 8 bytes of pseudo-random value. */
118 	bzero(&ctxt, sizeof(ctxt));
119 	MD5Init(&ctxt);
120 	MD5Update(&ctxt, hostname, hostnamelen);
121 	MD5Final(digest, &ctxt);
122 
123 	/* assumes sizeof(digest) > sizeof(ifid) */
124 	bcopy(digest, &in6->s6_addr[8], 8);
125 
126 	/* make sure to set "u" bit to local, and "g" bit to individual. */
127 	in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
128 	in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
129 
130 	/* convert EUI64 into IPv6 interface identifier */
131 	EUI64_TO_IFID(in6);
132 
133 	return 0;
134 }
135 
136 static int
137 generate_tmp_ifid(u_int8_t *seed0, const u_int8_t *seed1, u_int8_t *ret)
138 {
139 	MD5_CTX ctxt;
140 	u_int8_t seed[16], digest[16], nullbuf[8];
141 	u_int32_t val32;
142 	struct timeval tv;
143 
144 	/* If there's no hisotry, start with a random seed. */
145 	bzero(nullbuf, sizeof(nullbuf));
146 	if (bcmp(nullbuf, seed0, sizeof(nullbuf)) == 0) {
147 		int i;
148 
149 		for (i = 0; i < 2; i++) {
150 			microtime(&tv);
151 			val32 = krandom() ^ tv.tv_usec;
152 			bcopy(&val32, seed + sizeof(val32) * i, sizeof(val32));
153 		}
154 	} else {
155 		bcopy(seed0, seed, 8);
156 	}
157 
158 	/* copy the right-most 64-bits of the given address */
159 	/* XXX assumption on the size of IFID */
160 	bcopy(seed1, &seed[8], 8);
161 
162 	if (0) {		/* for debugging purposes only */
163 		int i;
164 
165 		kprintf("generate_tmp_ifid: new randomized ID from: ");
166 		for (i = 0; i < 16; i++)
167 			kprintf("%02x", seed[i]);
168 		kprintf(" ");
169 	}
170 
171 	/* generate 16 bytes of pseudo-random value. */
172 	bzero(&ctxt, sizeof(ctxt));
173 	MD5Init(&ctxt);
174 	MD5Update(&ctxt, seed, sizeof(seed));
175 	MD5Final(digest, &ctxt);
176 
177 	/*
178 	 * RFC 3041 3.2.1. (3)
179 	 * Take the left-most 64-bits of the MD5 digest and set bit 6 (the
180 	 * left-most bit is numbered 0) to zero.
181 	 */
182 	bcopy(digest, ret, 8);
183 	ret[0] &= ~EUI64_UBIT;
184 
185 	/*
186 	 * XXX: we'd like to ensure that the generated value is not zero
187 	 * for simplicity.  If the caclculated digest happens to be zero,
188 	 * use a random non-zero value as the last resort.
189 	 */
190 	if (bcmp(nullbuf, ret, sizeof(nullbuf)) == 0) {
191 		log(LOG_INFO,
192 		    "generate_tmp_ifid: computed MD5 value is zero.\n");
193 
194 		microtime(&tv);
195 		val32 = krandom() ^ tv.tv_usec;
196 		val32 = 1 + (val32 % (0xffffffff - 1));
197 	}
198 
199 	/*
200 	 * RFC 3041 3.2.1. (4)
201 	 * Take the rightmost 64-bits of the MD5 digest and save them in
202 	 * stable storage as the history value to be used in the next
203 	 * iteration of the algorithm.
204 	 */
205 	bcopy(&digest[8], seed0, 8);
206 
207 	if (0) {		/* for debugging purposes only */
208 		int i;
209 
210 		kprintf("to: ");
211 		for (i = 0; i < 16; i++)
212 			kprintf("%02x", digest[i]);
213 		kprintf("\n");
214 	}
215 
216 	return 0;
217 }
218 
219 /*
220  * Get interface identifier for the specified interface.
221  * XXX assumes single sockaddr_dl (AF_LINK address) per an interface
222  */
223 static int
224 get_hw_ifid(struct ifnet *ifp,
225 	    struct in6_addr *in6)	/* upper 64bits are preserved */
226 {
227 	struct ifaddr_container *ifac;
228 	struct sockaddr_dl *sdl;
229 	u_int8_t *addr;
230 	size_t addrlen;
231 	static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
232 	static u_int8_t allone[8] =
233 		{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
234 
235 	TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
236 		struct ifaddr *ifa = ifac->ifa;
237 
238 		if (ifa->ifa_addr->sa_family != AF_LINK)
239 			continue;
240 		sdl = (struct sockaddr_dl *)ifa->ifa_addr;
241 		if (sdl == NULL)
242 			continue;
243 		if (sdl->sdl_alen == 0)
244 			continue;
245 
246 		goto found;
247 	}
248 
249 	return -1;
250 
251 found:
252 	addr = LLADDR(sdl);
253 	addrlen = sdl->sdl_alen;
254 
255 	/* get EUI64 */
256 	switch (ifp->if_type) {
257 	case IFT_ETHER:
258 	case IFT_ATM:
259 	case IFT_IEEE1394:
260 #ifdef IFT_IEEE80211
261 	case IFT_IEEE80211:
262 #endif
263 		/* IEEE802/EUI64 cases - what others? */
264 		/* IEEE1394 uses 16byte length address starting with EUI64 */
265 		if (addrlen > 8)
266 			addrlen = 8;
267 
268 		/* look at IEEE802/EUI64 only */
269 		if (addrlen != 8 && addrlen != 6)
270 			return -1;
271 
272 		/*
273 		 * check for invalid MAC address - on bsdi, we see it a lot
274 		 * since wildboar configures all-zero MAC on pccard before
275 		 * card insertion.
276 		 */
277 		if (bcmp(addr, allzero, addrlen) == 0)
278 			return -1;
279 		if (bcmp(addr, allone, addrlen) == 0)
280 			return -1;
281 
282 		/* make EUI64 address */
283 		if (addrlen == 8)
284 			bcopy(addr, &in6->s6_addr[8], 8);
285 		else if (addrlen == 6) {
286 			in6->s6_addr[8] = addr[0];
287 			in6->s6_addr[9] = addr[1];
288 			in6->s6_addr[10] = addr[2];
289 			in6->s6_addr[11] = 0xff;
290 			in6->s6_addr[12] = 0xfe;
291 			in6->s6_addr[13] = addr[3];
292 			in6->s6_addr[14] = addr[4];
293 			in6->s6_addr[15] = addr[5];
294 		}
295 		break;
296 	case IFT_GIF:
297 #ifdef IFT_STF
298 	case IFT_STF:
299 #endif
300 		/*
301 		 * RFC2893 says: "SHOULD use IPv4 address as ifid source".
302 		 * however, IPv4 address is not very suitable as unique
303 		 * identifier source (can be renumbered).
304 		 * we don't do this.
305 		 */
306 		return -1;
307 
308 	default:
309 		return -1;
310 	}
311 
312 	/* sanity check: g bit must not indicate "group" */
313 	if (EUI64_GROUP(in6))
314 		return -1;
315 
316 	/* convert EUI64 into IPv6 interface identifier */
317 	EUI64_TO_IFID(in6);
318 
319 	/*
320 	 * sanity check: ifid must not be all zero, avoid conflict with
321 	 * subnet router anycast
322 	 */
323 	if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
324 	    bcmp(&in6->s6_addr[9], allzero, 7) == 0) {
325 		return -1;
326 	}
327 
328 	return 0;
329 }
330 
331 /*
332  * Get interface identifier for the specified interface.  If it is not
333  * available on ifp0, borrow interface identifier from other information
334  * sources.
335  */
336 static int
337 get_ifid(struct ifnet *ifp0,
338 	 struct ifnet *altifp,	/* secondary EUI64 source */
339 	 struct in6_addr *in6)
340 {
341 	struct ifnet *ifp;
342 
343 	/* first, try to get it from the interface itself */
344 	if (get_hw_ifid(ifp0, in6) == 0) {
345 		nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n",
346 		    if_name(ifp0)));
347 		goto success;
348 	}
349 
350 	/* try secondary EUI64 source. this basically is for ATM PVC */
351 	if (altifp && get_hw_ifid(altifp, in6) == 0) {
352 		nd6log((LOG_DEBUG, "%s: got interface identifier from %s\n",
353 		    if_name(ifp0), if_name(altifp)));
354 		goto success;
355 	}
356 
357 	/* next, try to get it from some other hardware interface */
358 	TAILQ_FOREACH(ifp, &ifnet, if_list) {
359 		if (ifp == ifp0)
360 			continue;
361 		if (get_hw_ifid(ifp, in6) != 0)
362 			continue;
363 
364 		/*
365 		 * to borrow ifid from other interface, ifid needs to be
366 		 * globally unique
367 		 */
368 		if (IFID_UNIVERSAL(in6)) {
369 			nd6log((LOG_DEBUG,
370 			    "%s: borrow interface identifier from %s\n",
371 			    if_name(ifp0), if_name(ifp)));
372 			goto success;
373 		}
374 	}
375 
376 	/* last resort: get from random number source */
377 	if (get_rand_ifid(ifp, in6) == 0) {
378 		nd6log((LOG_DEBUG,
379 		    "%s: interface identifier generated by random number\n",
380 		    if_name(ifp0)));
381 		goto success;
382 	}
383 
384 	kprintf("%s: failed to get interface identifier\n", if_name(ifp0));
385 	return -1;
386 
387 success:
388 	nd6log((LOG_INFO, "%s: ifid: "
389 		"%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
390 		if_name(ifp0),
391 		in6->s6_addr[8], in6->s6_addr[9],
392 		in6->s6_addr[10], in6->s6_addr[11],
393 		in6->s6_addr[12], in6->s6_addr[13],
394 		in6->s6_addr[14], in6->s6_addr[15]));
395 	return 0;
396 }
397 
398 static int
399 in6_ifattach_linklocal(struct ifnet *ifp,
400 		       struct ifnet *altifp)	/* secondary EUI64 source */
401 {
402 	struct in6_ifaddr *ia;
403 	struct in6_aliasreq ifra;
404 	struct nd_prefix pr0;
405 	int i, error;
406 
407 	/*
408 	 * configure link-local address.
409 	 */
410 	bzero(&ifra, sizeof(ifra));
411 
412 	/*
413 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
414 	 * for safety.
415 	 */
416 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
417 
418 	ifra.ifra_addr.sin6_family = AF_INET6;
419 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
420 	ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80);
421 	ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index); /* XXX */
422 	ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
423 	if (ifp->if_flags & IFF_LOOPBACK) {
424 		ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
425 		ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
426 	} else {
427 		if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) {
428 			nd6log((LOG_ERR,
429 			    "%s: no ifid available\n", if_name(ifp)));
430 			return -1;
431 		}
432 	}
433 
434 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
435 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
436 	ifra.ifra_prefixmask.sin6_addr = in6mask64;
437 
438 	/* link-local addresses should NEVER expire. */
439 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
440 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
441 
442 	/*
443 	 * Do not let in6_update_ifa() do DAD, since we need a random delay
444 	 * before sending an NS at the first time the interface becomes up.
445 	 * Instead, in6_if_up() will start DAD with a proper random delay.
446 	 */
447 	ifra.ifra_flags |= IN6_IFF_NODAD;
448 
449 	/*
450 	 * Now call in6_update_ifa() to do a bunch of procedures to configure
451 	 * a link-local address. We can set NULL to the 3rd argument, because
452 	 * we know there's no other link-local address on the interface
453 	 * and therefore we are adding one (instead of updating one).
454 	 */
455 	if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0) {
456 		/*
457 		 * XXX: When the interface does not support IPv6, this call
458 		 * would fail in the SIOCSIFADDR ioctl.  I believe the
459 		 * notification is rather confusing in this case, so just
460 		 * supress it.  (jinmei@kame.net 20010130)
461 		 */
462 		if (error != EAFNOSUPPORT)
463 			log(LOG_NOTICE, "in6_ifattach_linklocal: failed to "
464 			    "configure a link-local address on %s "
465 			    "(errno=%d)\n",
466 			    if_name(ifp), error);
467 		return (-1);
468 	}
469 
470 	/*
471 	 * Adjust ia6_flags so that in6_if_up will perform DAD.
472 	 * XXX: Some P2P interfaces seem not to send packets just after
473 	 * becoming up, so we skip p2p interfaces for safety.
474 	 */
475 	ia = in6ifa_ifpforlinklocal(ifp, 0); /* ia must not be NULL */
476 #ifdef DIAGNOSTIC
477 	if (!ia) {
478 		panic("ia == NULL in in6_ifattach_linklocal");
479 		/* NOTREACHED */
480 	}
481 #endif
482 	if (in6if_do_dad(ifp) && !(ifp->if_flags & IFF_POINTOPOINT)) {
483 		ia->ia6_flags &= ~IN6_IFF_NODAD;
484 		ia->ia6_flags |= IN6_IFF_TENTATIVE;
485 	}
486 
487 	/*
488 	 * Make the link-local prefix (fe80::/64%link) as on-link.
489 	 * Since we'd like to manage prefixes separately from addresses,
490 	 * we make an ND6 prefix structure for the link-local prefix,
491 	 * and add it to the prefix list as a never-expire prefix.
492 	 * XXX: this change might affect some existing code base...
493 	 */
494 	bzero(&pr0, sizeof(pr0));
495 	pr0.ndpr_ifp = ifp;
496 	/* this should be 64 at this moment. */
497 	pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
498 	pr0.ndpr_mask = ifra.ifra_prefixmask.sin6_addr;
499 	pr0.ndpr_prefix = ifra.ifra_addr;
500 	/* apply the mask for safety. (nd6_prelist_add will apply it again) */
501 	for (i = 0; i < 4; i++) {
502 		pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
503 			in6mask64.s6_addr32[i];
504 	}
505 	/*
506 	 * Initialize parameters.  The link-local prefix must always be
507 	 * on-link, and its lifetimes never expire.
508 	 */
509 	pr0.ndpr_raf_onlink = 1;
510 	pr0.ndpr_raf_auto = 1;	/* probably meaningless */
511 	pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
512 	pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
513 	/*
514 	 * Since there is no other link-local addresses, nd6_prefix_lookup()
515 	 * probably returns NULL.  However, we cannot always expect the result.
516 	 * For example, if we first remove the (only) existing link-local
517 	 * address, and then reconfigure another one, the prefix is still
518 	 * valid with referring to the old link-local address.
519 	 */
520 	if (nd6_prefix_lookup(&pr0) == NULL) {
521 		if ((error = nd6_prelist_add(&pr0, NULL, NULL)) != 0)
522 			return (error);
523 	}
524 
525 	return 0;
526 }
527 
528 static int
529 in6_ifattach_loopback(struct ifnet *ifp)	/* must be IFT_LOOP */
530 {
531 	struct in6_aliasreq ifra;
532 	int error;
533 
534 	bzero(&ifra, sizeof(ifra));
535 
536 	/*
537 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
538 	 * for safety.
539 	 */
540 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
541 
542 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
543 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
544 	ifra.ifra_prefixmask.sin6_addr = in6mask128;
545 
546 	/*
547 	 * Always initialize ia_dstaddr (= broadcast address) to loopback
548 	 * address.  Follows IPv4 practice - see in_ifinit().
549 	 */
550 	ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
551 	ifra.ifra_dstaddr.sin6_family = AF_INET6;
552 	ifra.ifra_dstaddr.sin6_addr = kin6addr_loopback;
553 
554 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
555 	ifra.ifra_addr.sin6_family = AF_INET6;
556 	ifra.ifra_addr.sin6_addr = kin6addr_loopback;
557 
558 	/* the loopback  address should NEVER expire. */
559 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
560 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
561 
562 	/* we don't need to perform DAD on loopback interfaces. */
563 	ifra.ifra_flags |= IN6_IFF_NODAD;
564 
565 	/* skip registration to the prefix list. XXX should be temporary. */
566 	ifra.ifra_flags |= IN6_IFF_NOPFX;
567 
568 	/*
569 	 * We are sure that this is a newly assigned address, so we can set
570 	 * NULL to the 3rd arg.
571 	 */
572 	if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0) {
573 		log(LOG_ERR, "in6_ifattach_loopback: failed to configure "
574 		    "the loopback address on %s (errno=%d)\n",
575 		    if_name(ifp), error);
576 		return (-1);
577 	}
578 
579 	return 0;
580 }
581 
582 /*
583  * compute NI group address, based on the current hostname setting.
584  * see draft-ietf-ipngwg-icmp-name-lookup-* (04 and later).
585  *
586  * when ifp == NULL, the caller is responsible for filling scopeid.
587  */
588 int
589 in6_nigroup(struct ifnet *ifp, const char *name, int namelen,
590 	    struct in6_addr *in6)
591 {
592 	const char *p;
593 	u_char *q;
594 	MD5_CTX ctxt;
595 	u_int8_t digest[16];
596 	char l;
597 	char n[64];	/* a single label must not exceed 63 chars */
598 
599 	if (!namelen || !name)
600 		return -1;
601 
602 	p = name;
603 	while (p && *p && *p != '.' && p - name < namelen)
604 		p++;
605 	if (p - name > sizeof(n) - 1)
606 		return -1;	/* label too long */
607 	l = p - name;
608 	strncpy(n, name, l);
609 	n[(int)l] = '\0';
610 	for (q = n; *q; q++) {
611 		if ('A' <= *q && *q <= 'Z')
612 			*q = *q - 'A' + 'a';
613 	}
614 
615 	/* generate 8 bytes of pseudo-random value. */
616 	bzero(&ctxt, sizeof(ctxt));
617 	MD5Init(&ctxt);
618 	MD5Update(&ctxt, &l, sizeof(l));
619 	MD5Update(&ctxt, n, l);
620 	MD5Final(digest, &ctxt);
621 
622 	bzero(in6, sizeof(*in6));
623 	in6->s6_addr16[0] = htons(0xff02);
624 	if (ifp)
625 		in6->s6_addr16[1] = htons(ifp->if_index);
626 	in6->s6_addr8[11] = 2;
627 	bcopy(digest, &in6->s6_addr32[3], sizeof(in6->s6_addr32[3]));
628 
629 	return 0;
630 }
631 
632 void
633 in6_nigroup_attach(const char *name, int namelen)
634 {
635 	struct ifnet *ifp;
636 	struct sockaddr_in6 mltaddr;
637 	struct in6_multi *in6m;
638 	int error;
639 
640 	bzero(&mltaddr, sizeof(mltaddr));
641 	mltaddr.sin6_family = AF_INET6;
642 	mltaddr.sin6_len = sizeof(struct sockaddr_in6);
643 	if (in6_nigroup(NULL, name, namelen, &mltaddr.sin6_addr) != 0)
644 		return;
645 
646 	TAILQ_FOREACH(ifp, &ifnet, if_list) {
647 		mltaddr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
648 		IN6_LOOKUP_MULTI(mltaddr.sin6_addr, ifp, in6m);
649 		if (!in6m) {
650 			if (!in6_addmulti(&mltaddr.sin6_addr, ifp, &error)) {
651 				nd6log((LOG_ERR, "%s: failed to join %s "
652 				    "(errno=%d)\n", if_name(ifp),
653 				    ip6_sprintf(&mltaddr.sin6_addr),
654 				    error));
655 			}
656 		}
657 	}
658 }
659 
660 void
661 in6_nigroup_detach(const char *name, int namelen)
662 {
663 	struct ifnet *ifp;
664 	struct sockaddr_in6 mltaddr;
665 	struct in6_multi *in6m;
666 
667 	bzero(&mltaddr, sizeof(mltaddr));
668 	mltaddr.sin6_family = AF_INET6;
669 	mltaddr.sin6_len = sizeof(struct sockaddr_in6);
670 	if (in6_nigroup(NULL, name, namelen, &mltaddr.sin6_addr) != 0)
671 		return;
672 
673 	TAILQ_FOREACH(ifp, &ifnet, if_list) {
674 		mltaddr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
675 		IN6_LOOKUP_MULTI(mltaddr.sin6_addr, ifp, in6m);
676 		if (in6m)
677 			in6_delmulti(in6m);
678 	}
679 }
680 
681 /*
682  * XXX multiple loopback interface needs more care.  for instance,
683  * nodelocal address needs to be configured onto only one of them.
684  * XXX multiple link-local address case
685  */
686 void
687 in6_ifattach(struct ifnet *ifp,
688 	     struct ifnet *altifp)	/* secondary EUI64 source */
689 {
690 	struct in6_ifaddr *ia;
691 	struct in6_addr in6;
692 
693 	/* some of the interfaces are inherently not IPv6 capable */
694 	switch (ifp->if_type) {
695 #ifdef IFT_BRIDGE	/*OpenBSD 2.8*/
696 	case IFT_BRIDGE:
697 		return;
698 #endif
699 	case IFT_PFLOG:
700 	case IFT_PFSYNC:
701 	case IFT_CARP:
702 		return;
703 	}
704 
705 	/*
706 	 * quirks based on interface type
707 	 */
708 	switch (ifp->if_type) {
709 #ifdef IFT_STF
710 	case IFT_STF:
711 		/*
712 		 * 6to4 interface is a very special kind of beast.
713 		 * no multicast, no linklocal.  RFC2529 specifies how to make
714 		 * linklocals for 6to4 interface, but there's no use and
715 		 * it is rather harmful to have one.
716 		 */
717 		goto statinit;
718 #endif
719 	default:
720 		break;
721 	}
722 
723 	/*
724 	 * usually, we require multicast capability to the interface
725 	 */
726 	if (!(ifp->if_flags & IFF_MULTICAST)) {
727 		log(LOG_INFO, "in6_ifattach: "
728 		    "%s is not multicast capable, IPv6 not enabled\n",
729 		    if_name(ifp));
730 		return;
731 	}
732 
733 	/*
734 	 * assign loopback address for loopback interface.
735 	 * XXX multiple loopback interface case.
736 	 */
737 	if (ifp->if_flags & IFF_LOOPBACK) {
738 		in6 = kin6addr_loopback;
739 		if (in6ifa_ifpwithaddr(ifp, &in6) == NULL) {
740 			if (in6_ifattach_loopback(ifp) != 0)
741 				return;
742 		}
743 	}
744 
745 	/*
746 	 * assign a link-local address, if there's none.
747 	 */
748 	if (ip6_auto_linklocal) {
749 		ia = in6ifa_ifpforlinklocal(ifp, 0);
750 		if (ia == NULL) {
751 			if (in6_ifattach_linklocal(ifp, altifp) == 0) {
752 				/* linklocal address assigned */
753 			} else {
754 				/* failed to assign linklocal address. bark? */
755 			}
756 		}
757 	}
758 
759 #ifdef IFT_STF			/* XXX */
760 statinit:
761 #endif
762 
763 	/* update dynamically. */
764 	if (in6_maxmtu < ifp->if_mtu)
765 		in6_maxmtu = ifp->if_mtu;
766 }
767 
768 /*
769  * NOTE: in6_ifdetach() does not support loopback if at this moment.
770  * We don't need this function in bsdi, because interfaces are never removed
771  * from the ifnet list in bsdi.
772  */
773 void
774 in6_ifdetach(struct ifnet *ifp)
775 {
776 	struct in6_ifaddr *ia, *oia;
777 	struct ifaddr_container *ifac, *next;
778 	struct rtentry *rt;
779 	short rtflags;
780 	struct sockaddr_in6 sin6;
781 	struct in6_multi *in6m;
782 	struct in6_multi *in6m_next;
783 
784 	/* nuke prefix list.  this may try to remove some of ifaddrs as well */
785 	in6_purgeprefix(ifp);
786 
787 	/* remove neighbor management table */
788 	nd6_purge(ifp);
789 
790 	/* nuke any of IPv6 addresses we have */
791 	TAILQ_FOREACH_MUTABLE(ifac, &ifp->if_addrheads[mycpuid], ifa_link, next) {
792 		struct ifaddr *ifa = ifac->ifa;
793 
794 		if (ifa->ifa_addr->sa_family != AF_INET6)
795 			continue;
796 		in6_purgeaddr(ifa);
797 	}
798 
799 	/* undo everything done by in6_ifattach(), just in case */
800 	TAILQ_FOREACH_MUTABLE(ifac, &ifp->if_addrheads[mycpuid], ifa_link, next) {
801 		struct ifaddr *ifa = ifac->ifa;
802 
803 		if (ifa->ifa_addr->sa_family != AF_INET6
804 		 || !IN6_IS_ADDR_LINKLOCAL(&satosin6(&ifa->ifa_addr)->sin6_addr)) {
805 			continue;
806 		}
807 
808 		ia = (struct in6_ifaddr *)ifa;
809 
810 		/* remove from the routing table */
811 		if ((ia->ia_flags & IFA_ROUTE) &&
812 		    (rt = rtpurelookup((struct sockaddr *)&ia->ia_addr))) {
813 			rtflags = rt->rt_flags;
814 			--rt->rt_refcnt;
815 			rtrequest(RTM_DELETE,
816 				(struct sockaddr *)&ia->ia_addr,
817 				(struct sockaddr *)&ia->ia_addr,
818 				(struct sockaddr *)&ia->ia_prefixmask,
819 				rtflags, (struct rtentry **)0);
820 		}
821 
822 		/* remove from the linked list */
823 		ifa_ifunlink((struct ifaddr *)ia, ifp);
824 
825 		/* also remove from the IPv6 address chain(itojun&jinmei) */
826 		oia = ia;
827 		if (oia == (ia = in6_ifaddr))
828 			in6_ifaddr = ia->ia_next;
829 		else {
830 			while (ia->ia_next && (ia->ia_next != oia))
831 				ia = ia->ia_next;
832 			if (ia->ia_next)
833 				ia->ia_next = oia->ia_next;
834 			else {
835 				nd6log((LOG_ERR,
836 				    "%s: didn't unlink in6ifaddr from "
837 				    "list\n", if_name(ifp)));
838 			}
839 		}
840 
841 		crit_enter();	/* XXX MP not MP safe */
842 		_IFAFREE(&oia->ia_ifa, 0);
843 		crit_exit();
844 
845 		ifa_destroy(&ia->ia_ifa);
846 	}
847 
848 	/* leave from all multicast groups joined */
849 	in6_pcbpurgeif0(LIST_FIRST(&udbinfo.pcblisthead), ifp);
850 	in6_pcbpurgeif0(LIST_FIRST(&ripcbinfo.pcblisthead), ifp);
851 	for (in6m = LIST_FIRST(&in6_multihead); in6m; in6m = in6m_next) {
852 		in6m_next = LIST_NEXT(in6m, in6m_entry);
853 		if (in6m->in6m_ifp != ifp)
854 			continue;
855 		in6_delmulti(in6m);
856 		in6m = NULL;
857 	}
858 
859 	/*
860 	 * remove neighbor management table.  we call it twice just to make
861 	 * sure we nuke everything.  maybe we need just one call.
862 	 * XXX: since the first call did not release addresses, some prefixes
863 	 * might remain.  We should call nd6_purge() again to release the
864 	 * prefixes after removing all addresses above.
865 	 * (Or can we just delay calling nd6_purge until at this point?)
866 	 */
867 	nd6_purge(ifp);
868 
869 	/* remove route to link-local allnodes multicast (ff02::1) */
870 	bzero(&sin6, sizeof(sin6));
871 	sin6.sin6_len = sizeof(struct sockaddr_in6);
872 	sin6.sin6_family = AF_INET6;
873 	sin6.sin6_addr = kin6addr_linklocal_allnodes;
874 	sin6.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
875 	rt = rtpurelookup((struct sockaddr *)&sin6);
876 	if (rt != NULL && rt->rt_ifp == ifp) {
877 		--rt->rt_refcnt;
878 		rtrequest(RTM_DELETE, (struct sockaddr *)rt_key(rt),
879 			rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
880 	}
881 }
882 
883 void
884 in6_get_tmpifid(struct ifnet *ifp, u_int8_t *retbuf, const u_int8_t *baseid,
885 		int generate)
886 {
887 	u_int8_t nullbuf[8];
888 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
889 
890 	bzero(nullbuf, sizeof(nullbuf));
891 	if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
892 		/* we've never created a random ID.  Create a new one. */
893 		generate = 1;
894 	}
895 
896 	if (generate) {
897 		bcopy(baseid, ndi->randomseed1, sizeof(ndi->randomseed1));
898 
899 		/* generate_tmp_ifid will update seedn and buf */
900 		generate_tmp_ifid(ndi->randomseed0, ndi->randomseed1,
901 				  ndi->randomid);
902 	}
903 	bcopy(ndi->randomid, retbuf, 8);
904 }
905 
906 void
907 in6_tmpaddrtimer(void *ignored_arg)
908 {
909 	struct nd_ifinfo *ndi;
910 	u_int8_t nullbuf[8];
911 	struct ifnet *ifp;
912 
913 	crit_enter();
914 
915 	callout_reset(&in6_tmpaddrtimer_ch,
916 		      (ip6_temp_preferred_lifetime - ip6_desync_factor -
917 		       ip6_temp_regen_advance) * hz,
918 		      in6_tmpaddrtimer, NULL);
919 
920 	bzero(nullbuf, sizeof(nullbuf));
921 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
922 		ndi = ND_IFINFO(ifp);
923 		if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
924 			/*
925 			 * We've been generating a random ID on this interface.
926 			 * Create a new one.
927 			 */
928 			generate_tmp_ifid(ndi->randomseed0,
929 					  ndi->randomseed1,
930 					  ndi->randomid);
931 		}
932 	}
933 
934 	crit_exit();
935 }
936