xref: /dflybsd-src/sys/netinet6/in6_ifattach.c (revision 31c068aaf635ad9fa72dbc4c65b32d890ff7544d)
1 /*	$FreeBSD: src/sys/netinet6/in6_ifattach.c,v 1.2.2.6 2002/04/28 05:40:26 suz Exp $	*/
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 #include <sys/thread2.h>
42 
43 #include <net/if.h>
44 #include <net/if_dl.h>
45 #include <net/if_types.h>
46 #include <net/route.h>
47 #include <net/netisr2.h>
48 #include <net/netmsg2.h>
49 
50 #include <netinet/in.h>
51 #include <netinet/in_var.h>
52 #include <netinet/if_ether.h>
53 #include <netinet/in_pcb.h>
54 #include <netinet/udp_var.h>
55 
56 #include <netinet/ip6.h>
57 #include <netinet6/ip6_var.h>
58 #include <netinet6/in6_var.h>
59 #include <netinet6/in6_pcb.h>
60 #include <netinet6/in6_ifattach.h>
61 #include <netinet6/nd6.h>
62 #include <netinet6/scope6_var.h>
63 
64 #include <net/net_osdep.h>
65 
66 unsigned long in6_maxmtu = 0;
67 
68 #ifdef IP6_AUTO_LINKLOCAL
69 int ip6_auto_linklocal = IP6_AUTO_LINKLOCAL;
70 #else
71 int ip6_auto_linklocal = 1;	/* enable by default */
72 #endif
73 
74 static struct callout in6_tmpaddrtimer_ch;
75 static struct netmsg_base in6_tmpaddrtimer_netmsg;
76 
77 extern struct inpcbinfo ripcbinfo;
78 
79 static int get_rand_ifid (struct ifnet *, struct in6_addr *);
80 static int generate_tmp_ifid (u_int8_t *, const u_int8_t *, u_int8_t *);
81 static int get_hw_ifid (struct ifnet *, struct in6_addr *);
82 static int get_ifid (struct ifnet *, struct ifnet *, struct in6_addr *);
83 static int in6_ifattach_linklocal (struct ifnet *, struct ifnet *);
84 static int in6_ifattach_loopback (struct ifnet *);
85 
86 #define EUI64_GBIT	0x01
87 #define EUI64_UBIT	0x02
88 #define EUI64_TO_IFID(in6)	do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (0)
89 #define EUI64_GROUP(in6)	((in6)->s6_addr[8] & EUI64_GBIT)
90 #define EUI64_INDIVIDUAL(in6)	(!EUI64_GROUP(in6))
91 #define EUI64_LOCAL(in6)	((in6)->s6_addr[8] & EUI64_UBIT)
92 #define EUI64_UNIVERSAL(in6)	(!EUI64_LOCAL(in6))
93 
94 #define IFID_LOCAL(in6)		(!EUI64_LOCAL(in6))
95 #define IFID_UNIVERSAL(in6)	(!EUI64_UNIVERSAL(in6))
96 
97 /*
98  * Generate a last-resort interface identifier, when the machine has no
99  * IEEE802/EUI64 address sources.
100  * The goal here is to get an interface identifier that is
101  * (1) random enough and (2) does not change across reboot.
102  * We currently use MD5(hostname) for it.
103  */
104 static int
105 get_rand_ifid(struct ifnet *ifp,
106 	      struct in6_addr *in6)	/* upper 64bits are preserved */
107 {
108 	MD5_CTX ctxt;
109 	u_int8_t digest[16];
110 	int hostnamelen	= strlen(hostname);
111 
112 #if 0
113 	/* we need at least several letters as seed for ifid */
114 	if (hostnamelen < 3)
115 		return -1;
116 #endif
117 
118 	/* generate 8 bytes of pseudo-random value. */
119 	bzero(&ctxt, sizeof(ctxt));
120 	MD5Init(&ctxt);
121 	MD5Update(&ctxt, hostname, hostnamelen);
122 	MD5Final(digest, &ctxt);
123 
124 	/* assumes sizeof(digest) > sizeof(ifid) */
125 	bcopy(digest, &in6->s6_addr[8], 8);
126 
127 	/* make sure to set "u" bit to local, and "g" bit to individual. */
128 	in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
129 	in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
130 
131 	/* convert EUI64 into IPv6 interface identifier */
132 	EUI64_TO_IFID(in6);
133 
134 	return 0;
135 }
136 
137 static int
138 generate_tmp_ifid(u_int8_t *seed0, const u_int8_t *seed1, u_int8_t *ret)
139 {
140 	MD5_CTX ctxt;
141 	u_int8_t seed[16], digest[16], nullbuf[8];
142 	u_int32_t val32;
143 	struct timeval tv;
144 
145 	/* If there's no hisotry, start with a random seed. */
146 	bzero(nullbuf, sizeof(nullbuf));
147 	if (bcmp(nullbuf, seed0, sizeof(nullbuf)) == 0) {
148 		int i;
149 
150 		for (i = 0; i < 2; i++) {
151 			microtime(&tv);
152 			val32 = krandom() ^ tv.tv_usec;
153 			bcopy(&val32, seed + sizeof(val32) * i, sizeof(val32));
154 		}
155 	} else {
156 		bcopy(seed0, seed, 8);
157 	}
158 
159 	/* copy the right-most 64-bits of the given address */
160 	/* XXX assumption on the size of IFID */
161 	bcopy(seed1, &seed[8], 8);
162 
163 	if (0) {		/* for debugging purposes only */
164 		int i;
165 
166 		kprintf("generate_tmp_ifid: new randomized ID from: ");
167 		for (i = 0; i < 16; i++)
168 			kprintf("%02x", seed[i]);
169 		kprintf(" ");
170 	}
171 
172 	/* generate 16 bytes of pseudo-random value. */
173 	bzero(&ctxt, sizeof(ctxt));
174 	MD5Init(&ctxt);
175 	MD5Update(&ctxt, seed, sizeof(seed));
176 	MD5Final(digest, &ctxt);
177 
178 	/*
179 	 * RFC 3041 3.2.1. (3)
180 	 * Take the left-most 64-bits of the MD5 digest and set bit 6 (the
181 	 * left-most bit is numbered 0) to zero.
182 	 */
183 	bcopy(digest, ret, 8);
184 	ret[0] &= ~EUI64_UBIT;
185 
186 	/*
187 	 * XXX: we'd like to ensure that the generated value is not zero
188 	 * for simplicity.  If the caclculated digest happens to be zero,
189 	 * use a random non-zero value as the last resort.
190 	 */
191 	if (bcmp(nullbuf, ret, sizeof(nullbuf)) == 0) {
192 		log(LOG_INFO,
193 		    "generate_tmp_ifid: computed MD5 value is zero.\n");
194 
195 		microtime(&tv);
196 		val32 = krandom() ^ tv.tv_usec;
197 		val32 = 1 + (val32 % (0xffffffff - 1));
198 	}
199 
200 	/*
201 	 * RFC 3041 3.2.1. (4)
202 	 * Take the rightmost 64-bits of the MD5 digest and save them in
203 	 * stable storage as the history value to be used in the next
204 	 * iteration of the algorithm.
205 	 */
206 	bcopy(&digest[8], seed0, 8);
207 
208 	if (0) {		/* for debugging purposes only */
209 		int i;
210 
211 		kprintf("to: ");
212 		for (i = 0; i < 16; i++)
213 			kprintf("%02x", digest[i]);
214 		kprintf("\n");
215 	}
216 
217 	return 0;
218 }
219 
220 /*
221  * Get interface identifier for the specified interface.
222  * XXX assumes single sockaddr_dl (AF_LINK address) per an interface
223  */
224 static int
225 get_hw_ifid(struct ifnet *ifp,
226 	    struct in6_addr *in6)	/* upper 64bits are preserved */
227 {
228 	struct ifaddr_container *ifac;
229 	struct sockaddr_dl *sdl;
230 	u_int8_t *addr;
231 	size_t addrlen;
232 	static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
233 	static u_int8_t allone[8] =
234 		{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
235 
236 	TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
237 		struct ifaddr *ifa = ifac->ifa;
238 
239 		if (ifa->ifa_addr->sa_family != AF_LINK)
240 			continue;
241 		sdl = (struct sockaddr_dl *)ifa->ifa_addr;
242 		if (sdl == NULL)
243 			continue;
244 		if (sdl->sdl_alen == 0)
245 			continue;
246 
247 		goto found;
248 	}
249 
250 	return -1;
251 
252 found:
253 	addr = LLADDR(sdl);
254 	addrlen = sdl->sdl_alen;
255 
256 	/* get EUI64 */
257 	switch (ifp->if_type) {
258 	case IFT_ETHER:
259 	case IFT_ATM:
260 	case IFT_IEEE1394:
261 #ifdef IFT_IEEE80211
262 	case IFT_IEEE80211:
263 #endif
264 		/* IEEE802/EUI64 cases - what others? */
265 		/* IEEE1394 uses 16byte length address starting with EUI64 */
266 		if (addrlen > 8)
267 			addrlen = 8;
268 
269 		/* look at IEEE802/EUI64 only */
270 		if (addrlen != 8 && addrlen != 6)
271 			return -1;
272 
273 		/*
274 		 * check for invalid MAC address - on bsdi, we see it a lot
275 		 * since wildboar configures all-zero MAC on pccard before
276 		 * card insertion.
277 		 */
278 		if (bcmp(addr, allzero, addrlen) == 0)
279 			return -1;
280 		if (bcmp(addr, allone, addrlen) == 0)
281 			return -1;
282 
283 		/* make EUI64 address */
284 		if (addrlen == 8)
285 			bcopy(addr, &in6->s6_addr[8], 8);
286 		else if (addrlen == 6) {
287 			in6->s6_addr[8] = addr[0];
288 			in6->s6_addr[9] = addr[1];
289 			in6->s6_addr[10] = addr[2];
290 			in6->s6_addr[11] = 0xff;
291 			in6->s6_addr[12] = 0xfe;
292 			in6->s6_addr[13] = addr[3];
293 			in6->s6_addr[14] = addr[4];
294 			in6->s6_addr[15] = addr[5];
295 		}
296 		break;
297 	case IFT_GIF:
298 #ifdef IFT_STF
299 	case IFT_STF:
300 #endif
301 		/*
302 		 * RFC2893 says: "SHOULD use IPv4 address as ifid source".
303 		 * however, IPv4 address is not very suitable as unique
304 		 * identifier source (can be renumbered).
305 		 * we don't do this.
306 		 */
307 		return -1;
308 
309 	default:
310 		return -1;
311 	}
312 
313 	/* sanity check: g bit must not indicate "group" */
314 	if (EUI64_GROUP(in6))
315 		return -1;
316 
317 	/* convert EUI64 into IPv6 interface identifier */
318 	EUI64_TO_IFID(in6);
319 
320 	/*
321 	 * sanity check: ifid must not be all zero, avoid conflict with
322 	 * subnet router anycast
323 	 */
324 	if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
325 	    bcmp(&in6->s6_addr[9], allzero, 7) == 0) {
326 		return -1;
327 	}
328 
329 	return 0;
330 }
331 
332 /*
333  * Get interface identifier for the specified interface.  If it is not
334  * available on ifp0, borrow interface identifier from other information
335  * sources.
336  */
337 static int
338 get_ifid(struct ifnet *ifp0,
339 	 struct ifnet *altifp,	/* secondary EUI64 source */
340 	 struct in6_addr *in6)
341 {
342 	struct ifnet *ifp;
343 
344 	/* first, try to get it from the interface itself */
345 	if (get_hw_ifid(ifp0, in6) == 0) {
346 		nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n",
347 		    if_name(ifp0)));
348 		goto success;
349 	}
350 
351 	/* try secondary EUI64 source. this basically is for ATM PVC */
352 	if (altifp && get_hw_ifid(altifp, in6) == 0) {
353 		nd6log((LOG_DEBUG, "%s: got interface identifier from %s\n",
354 		    if_name(ifp0), if_name(altifp)));
355 		goto success;
356 	}
357 
358 	/* next, try to get it from some other hardware interface */
359 	TAILQ_FOREACH(ifp, &ifnet, if_list) {
360 		if (ifp == ifp0)
361 			continue;
362 		if (get_hw_ifid(ifp, in6) != 0)
363 			continue;
364 
365 		/*
366 		 * to borrow ifid from other interface, ifid needs to be
367 		 * globally unique
368 		 */
369 		if (IFID_UNIVERSAL(in6)) {
370 			nd6log((LOG_DEBUG,
371 			    "%s: borrow interface identifier from %s\n",
372 			    if_name(ifp0), if_name(ifp)));
373 			goto success;
374 		}
375 	}
376 
377 	/* last resort: get from random number source */
378 	if (get_rand_ifid(ifp, in6) == 0) {
379 		nd6log((LOG_DEBUG,
380 		    "%s: interface identifier generated by random number\n",
381 		    if_name(ifp0)));
382 		goto success;
383 	}
384 
385 	kprintf("%s: failed to get interface identifier\n", if_name(ifp0));
386 	return -1;
387 
388 success:
389 	nd6log((LOG_INFO, "%s: ifid: "
390 		"%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
391 		if_name(ifp0),
392 		in6->s6_addr[8], in6->s6_addr[9],
393 		in6->s6_addr[10], in6->s6_addr[11],
394 		in6->s6_addr[12], in6->s6_addr[13],
395 		in6->s6_addr[14], in6->s6_addr[15]));
396 	return 0;
397 }
398 
399 static int
400 in6_ifattach_linklocal(struct ifnet *ifp,
401 		       struct ifnet *altifp)	/* secondary EUI64 source */
402 {
403 	struct in6_ifaddr *ia;
404 	struct in6_aliasreq ifra;
405 	struct nd_prefix pr0;
406 	int i, error;
407 
408 	/*
409 	 * configure link-local address.
410 	 */
411 	bzero(&ifra, sizeof(ifra));
412 
413 	/*
414 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
415 	 * for safety.
416 	 */
417 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
418 
419 	ifra.ifra_addr.sin6_family = AF_INET6;
420 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
421 	ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80);
422 	ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index); /* XXX */
423 	ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
424 	if (ifp->if_flags & IFF_LOOPBACK) {
425 		ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
426 		ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
427 	} else {
428 		if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) {
429 			nd6log((LOG_ERR,
430 			    "%s: no ifid available\n", if_name(ifp)));
431 			return -1;
432 		}
433 	}
434 
435 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
436 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
437 	ifra.ifra_prefixmask.sin6_addr = in6mask64;
438 
439 	/* link-local addresses should NEVER expire. */
440 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
441 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
442 
443 	/*
444 	 * Do not let in6_update_ifa() do DAD, since we need a random delay
445 	 * before sending an NS at the first time the interface becomes up.
446 	 * Instead, in6_if_up() will start DAD with a proper random delay.
447 	 */
448 	ifra.ifra_flags |= IN6_IFF_NODAD;
449 
450 	/*
451 	 * Now call in6_update_ifa() to do a bunch of procedures to configure
452 	 * a link-local address. We can set NULL to the 3rd argument, because
453 	 * we know there's no other link-local address on the interface
454 	 * and therefore we are adding one (instead of updating one).
455 	 */
456 	if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0) {
457 		/*
458 		 * XXX: When the interface does not support IPv6, this call
459 		 * would fail in the SIOCSIFADDR ioctl.  I believe the
460 		 * notification is rather confusing in this case, so just
461 		 * supress it.  (jinmei@kame.net 20010130)
462 		 */
463 		if (error != EAFNOSUPPORT)
464 			log(LOG_NOTICE, "in6_ifattach_linklocal: failed to "
465 			    "configure a link-local address on %s "
466 			    "(errno=%d)\n",
467 			    if_name(ifp), error);
468 		return (-1);
469 	}
470 
471 	/*
472 	 * Adjust ia6_flags so that in6_if_up will perform DAD.
473 	 * XXX: Some P2P interfaces seem not to send packets just after
474 	 * becoming up, so we skip p2p interfaces for safety.
475 	 */
476 	ia = in6ifa_ifpforlinklocal(ifp, 0); /* ia must not be NULL */
477 #ifdef DIAGNOSTIC
478 	if (!ia) {
479 		panic("ia == NULL in in6_ifattach_linklocal");
480 		/* NOTREACHED */
481 	}
482 #endif
483 	if (in6if_do_dad(ifp) && !(ifp->if_flags & IFF_POINTOPOINT)) {
484 		ia->ia6_flags &= ~IN6_IFF_NODAD;
485 		ia->ia6_flags |= IN6_IFF_TENTATIVE;
486 	}
487 
488 	/*
489 	 * Make the link-local prefix (fe80::/64%link) as on-link.
490 	 * Since we'd like to manage prefixes separately from addresses,
491 	 * we make an ND6 prefix structure for the link-local prefix,
492 	 * and add it to the prefix list as a never-expire prefix.
493 	 * XXX: this change might affect some existing code base...
494 	 */
495 	bzero(&pr0, sizeof(pr0));
496 	pr0.ndpr_ifp = ifp;
497 	/* this should be 64 at this moment. */
498 	pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
499 	pr0.ndpr_mask = ifra.ifra_prefixmask.sin6_addr;
500 	pr0.ndpr_prefix = ifra.ifra_addr;
501 	/* apply the mask for safety. (nd6_prelist_add will apply it again) */
502 	for (i = 0; i < 4; i++) {
503 		pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
504 			in6mask64.s6_addr32[i];
505 	}
506 	/*
507 	 * Initialize parameters.  The link-local prefix must always be
508 	 * on-link, and its lifetimes never expire.
509 	 */
510 	pr0.ndpr_raf_onlink = 1;
511 	pr0.ndpr_raf_auto = 1;	/* probably meaningless */
512 	pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
513 	pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
514 	/*
515 	 * Since there is no other link-local addresses, nd6_prefix_lookup()
516 	 * probably returns NULL.  However, we cannot always expect the result.
517 	 * For example, if we first remove the (only) existing link-local
518 	 * address, and then reconfigure another one, the prefix is still
519 	 * valid with referring to the old link-local address.
520 	 */
521 	if (nd6_prefix_lookup(&pr0) == NULL) {
522 		if ((error = nd6_prelist_add(&pr0, NULL, NULL)) != 0)
523 			return (error);
524 	}
525 
526 	return 0;
527 }
528 
529 static int
530 in6_ifattach_loopback(struct ifnet *ifp)	/* must be IFT_LOOP */
531 {
532 	struct in6_aliasreq ifra;
533 	int error;
534 
535 	bzero(&ifra, sizeof(ifra));
536 
537 	/*
538 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
539 	 * for safety.
540 	 */
541 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
542 
543 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
544 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
545 	ifra.ifra_prefixmask.sin6_addr = in6mask128;
546 
547 	/*
548 	 * Always initialize ia_dstaddr (= broadcast address) to loopback
549 	 * address.  Follows IPv4 practice - see in_ifinit().
550 	 */
551 	ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
552 	ifra.ifra_dstaddr.sin6_family = AF_INET6;
553 	ifra.ifra_dstaddr.sin6_addr = kin6addr_loopback;
554 
555 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
556 	ifra.ifra_addr.sin6_family = AF_INET6;
557 	ifra.ifra_addr.sin6_addr = kin6addr_loopback;
558 
559 	/* the loopback  address should NEVER expire. */
560 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
561 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
562 
563 	/* we don't need to perform DAD on loopback interfaces. */
564 	ifra.ifra_flags |= IN6_IFF_NODAD;
565 
566 	/* skip registration to the prefix list. XXX should be temporary. */
567 	ifra.ifra_flags |= IN6_IFF_NOPFX;
568 
569 	/*
570 	 * We are sure that this is a newly assigned address, so we can set
571 	 * NULL to the 3rd arg.
572 	 */
573 	if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0) {
574 		log(LOG_ERR, "in6_ifattach_loopback: failed to configure "
575 		    "the loopback address on %s (errno=%d)\n",
576 		    if_name(ifp), error);
577 		return (-1);
578 	}
579 
580 	return 0;
581 }
582 
583 /*
584  * compute NI group address, based on the current hostname setting.
585  * see draft-ietf-ipngwg-icmp-name-lookup-* (04 and later).
586  *
587  * when ifp == NULL, the caller is responsible for filling scopeid.
588  */
589 int
590 in6_nigroup(struct ifnet *ifp, const char *name, int namelen,
591 	    struct in6_addr *in6)
592 {
593 	const char *p;
594 	u_char *q;
595 	MD5_CTX ctxt;
596 	u_int8_t digest[16];
597 	char l;
598 	char n[64];	/* a single label must not exceed 63 chars */
599 
600 	if (!namelen || !name)
601 		return -1;
602 
603 	p = name;
604 	while (p && *p && *p != '.' && p - name < namelen)
605 		p++;
606 	if (p - name > sizeof(n) - 1)
607 		return -1;	/* label too long */
608 	l = p - name;
609 	strncpy(n, name, l);
610 	n[(int)l] = '\0';
611 	for (q = n; *q; q++) {
612 		if ('A' <= *q && *q <= 'Z')
613 			*q = *q - 'A' + 'a';
614 	}
615 
616 	/* generate 8 bytes of pseudo-random value. */
617 	bzero(&ctxt, sizeof(ctxt));
618 	MD5Init(&ctxt);
619 	MD5Update(&ctxt, &l, sizeof(l));
620 	MD5Update(&ctxt, n, l);
621 	MD5Final(digest, &ctxt);
622 
623 	bzero(in6, sizeof(*in6));
624 	in6->s6_addr16[0] = htons(0xff02);
625 	if (ifp)
626 		in6->s6_addr16[1] = htons(ifp->if_index);
627 	in6->s6_addr8[11] = 2;
628 	bcopy(digest, &in6->s6_addr32[3], sizeof(in6->s6_addr32[3]));
629 
630 	return 0;
631 }
632 
633 struct netmsg_nigroup {
634 	struct netmsg_base	nmsg;
635 	const char		*name;
636 	int			namelen;
637 };
638 
639 static void
640 in6_nigroup_attach_dispatch(netmsg_t msg)
641 {
642 	struct netmsg_nigroup *nmsg = (struct netmsg_nigroup *)msg;
643 	struct ifnet *ifp;
644 	struct sockaddr_in6 mltaddr;
645 	struct in6_multi *in6m;
646 	int error;
647 
648 	bzero(&mltaddr, sizeof(mltaddr));
649 	mltaddr.sin6_family = AF_INET6;
650 	mltaddr.sin6_len = sizeof(struct sockaddr_in6);
651 	if (in6_nigroup(NULL, nmsg->name, nmsg->namelen,
652 	    &mltaddr.sin6_addr) != 0)
653 		goto done;
654 
655 	TAILQ_FOREACH(ifp, &ifnet, if_list) {
656 		mltaddr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
657 		in6m = IN6_LOOKUP_MULTI(&mltaddr.sin6_addr, ifp);
658 		if (!in6m) {
659 			if (!in6_addmulti(&mltaddr.sin6_addr, ifp, &error)) {
660 				nd6log((LOG_ERR, "%s: failed to join %s "
661 				    "(errno=%d)\n", if_name(ifp),
662 				    ip6_sprintf(&mltaddr.sin6_addr),
663 				    error));
664 			}
665 		}
666 	}
667 done:
668 	lwkt_replymsg(&nmsg->nmsg.lmsg, 0);
669 }
670 
671 void
672 in6_nigroup_attach(const char *name, int namelen)
673 {
674 	struct netmsg_nigroup nmsg;
675 
676 	netmsg_init(&nmsg.nmsg, NULL, &curthread->td_msgport, 0,
677 	    in6_nigroup_attach_dispatch);
678 	nmsg.name = name;
679 	nmsg.namelen = namelen;
680 	lwkt_domsg(netisr_cpuport(0), &nmsg.nmsg.lmsg, 0);
681 }
682 
683 static void
684 in6_nigroup_detach_dispatch(netmsg_t msg)
685 {
686 	struct netmsg_nigroup *nmsg = (struct netmsg_nigroup *)msg;
687 	struct ifnet *ifp;
688 	struct sockaddr_in6 mltaddr;
689 	struct in6_multi *in6m;
690 
691 	bzero(&mltaddr, sizeof(mltaddr));
692 	mltaddr.sin6_family = AF_INET6;
693 	mltaddr.sin6_len = sizeof(struct sockaddr_in6);
694 	if (in6_nigroup(NULL, nmsg->name, nmsg->namelen,
695 	    &mltaddr.sin6_addr) != 0)
696 		goto done;
697 
698 	TAILQ_FOREACH(ifp, &ifnet, if_list) {
699 		mltaddr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
700 		in6m = IN6_LOOKUP_MULTI(&mltaddr.sin6_addr, ifp);
701 		if (in6m)
702 			in6_delmulti(in6m);
703 	}
704 done:
705 	lwkt_replymsg(&nmsg->nmsg.lmsg, 0);
706 }
707 
708 void
709 in6_nigroup_detach(const char *name, int namelen)
710 {
711 	struct netmsg_nigroup nmsg;
712 
713 	netmsg_init(&nmsg.nmsg, NULL, &curthread->td_msgport, 0,
714 	    in6_nigroup_detach_dispatch);
715 	nmsg.name = name;
716 	nmsg.namelen = namelen;
717 	lwkt_domsg(netisr_cpuport(0), &nmsg.nmsg.lmsg, 0);
718 }
719 
720 /*
721  * XXX multiple loopback interface needs more care.  for instance,
722  * nodelocal address needs to be configured onto only one of them.
723  * XXX multiple link-local address case
724  */
725 void
726 in6_ifattach(struct ifnet *ifp,
727 	     struct ifnet *altifp)	/* secondary EUI64 source */
728 {
729 	struct in6_ifaddr *ia;
730 	struct in6_addr in6;
731 
732 	/* some of the interfaces are inherently not IPv6 capable */
733 	switch (ifp->if_type) {
734 #ifdef IFT_BRIDGE	/*OpenBSD 2.8*/
735 	case IFT_BRIDGE:
736 		return;
737 #endif
738 	case IFT_PFLOG:
739 	case IFT_PFSYNC:
740 	case IFT_CARP:
741 		return;
742 	}
743 
744 	/*
745 	 * quirks based on interface type
746 	 */
747 	switch (ifp->if_type) {
748 #ifdef IFT_STF
749 	case IFT_STF:
750 		/*
751 		 * 6to4 interface is a very special kind of beast.
752 		 * no multicast, no linklocal.  RFC2529 specifies how to make
753 		 * linklocals for 6to4 interface, but there's no use and
754 		 * it is rather harmful to have one.
755 		 */
756 		goto statinit;
757 #endif
758 	default:
759 		break;
760 	}
761 
762 	/*
763 	 * usually, we require multicast capability to the interface
764 	 */
765 	if (!(ifp->if_flags & IFF_MULTICAST)) {
766 		log(LOG_INFO, "in6_ifattach: "
767 		    "%s is not multicast capable, IPv6 not enabled\n",
768 		    if_name(ifp));
769 		return;
770 	}
771 
772 	/*
773 	 * assign loopback address for loopback interface.
774 	 * XXX multiple loopback interface case.
775 	 */
776 	if (ifp->if_flags & IFF_LOOPBACK) {
777 		in6 = kin6addr_loopback;
778 		if (in6ifa_ifpwithaddr(ifp, &in6) == NULL) {
779 			if (in6_ifattach_loopback(ifp) != 0)
780 				return;
781 		}
782 	}
783 
784 	/*
785 	 * assign a link-local address, if there's none.
786 	 */
787 	if (ip6_auto_linklocal) {
788 		ia = in6ifa_ifpforlinklocal(ifp, 0);
789 		if (ia == NULL) {
790 			if (in6_ifattach_linklocal(ifp, altifp) == 0) {
791 				/* linklocal address assigned */
792 			} else {
793 				/* failed to assign linklocal address. bark? */
794 			}
795 		}
796 	}
797 
798 #ifdef IFT_STF			/* XXX */
799 statinit:
800 #endif
801 
802 	/* update dynamically. */
803 	if (in6_maxmtu < ifp->if_mtu)
804 		in6_maxmtu = ifp->if_mtu;
805 }
806 
807 /*
808  * NOTE: in6_ifdetach() does not support loopback if at this moment.
809  */
810 static void
811 in6_ifdetach_dispatch(netmsg_t nmsg)
812 {
813 	struct lwkt_msg *lmsg = &nmsg->lmsg;
814 	struct ifnet *ifp = lmsg->u.ms_resultp;
815 	struct ifaddr_container *ifac, *next;
816 	struct rtentry *rt;
817 	struct sockaddr_in6 sin6;
818 	struct in6_multi *in6m, *in6m_next;
819 
820 	KASSERT(&curthread->td_msgport == netisr_cpuport(0),
821 	    ("not in netisr0"));
822 
823 	/* remove neighbor management table */
824 	nd6_purge(ifp);
825 
826 	/* nuke any of IPv6 addresses we have */
827 	TAILQ_FOREACH_MUTABLE(ifac, &ifp->if_addrheads[mycpuid], ifa_link, next) {
828 		struct ifaddr *ifa = ifac->ifa;
829 
830 		if (ifa->ifa_addr->sa_family != AF_INET6)
831 			continue;
832 		in6_purgeaddr(ifa);
833 	}
834 
835 	/*
836 	 * XXX
837 	 * These were code trying to nuke inet6 addresses again, but all
838 	 * inet6 addresses must have been deleted above; use assertion.
839 	 */
840 	TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
841 		KASSERT(ifac->ifa->ifa_addr->sa_family != AF_INET6,
842 		    ("still has inet6 addr"));
843 	}
844 
845 	/* leave from all multicast groups joined */
846 	in6_pcbpurgeif0(&ripcbinfo, ifp);
847 	in6_pcbpurgeif0(&udbinfo[0], ifp);
848 	for (in6m = LIST_FIRST(&in6_multihead); in6m; in6m = in6m_next) {
849 		in6m_next = LIST_NEXT(in6m, in6m_entry);
850 		if (in6m->in6m_ifp != ifp)
851 			continue;
852 		in6_delmulti(in6m);
853 		in6m = NULL;
854 	}
855 
856 	/*
857 	 * remove neighbor management table.  we call it twice just to make
858 	 * sure we nuke everything.  maybe we need just one call.
859 	 * XXX: since the first call did not release addresses, some prefixes
860 	 * might remain.  We should call nd6_purge() again to release the
861 	 * prefixes after removing all addresses above.
862 	 * (Or can we just delay calling nd6_purge until at this point?)
863 	 */
864 	nd6_purge(ifp);
865 
866 	/* remove route to link-local allnodes multicast (ff02::1) */
867 	bzero(&sin6, sizeof(sin6));
868 	sin6.sin6_len = sizeof(struct sockaddr_in6);
869 	sin6.sin6_family = AF_INET6;
870 	sin6.sin6_addr = kin6addr_linklocal_allnodes;
871 	sin6.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
872 	rt = rtpurelookup((struct sockaddr *)&sin6);
873 	if (rt != NULL && rt->rt_ifp == ifp) {
874 		--rt->rt_refcnt;
875 		rtrequest(RTM_DELETE, (struct sockaddr *)rt_key(rt),
876 			rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
877 	}
878 
879 	lwkt_replymsg(lmsg, 0);
880 }
881 
882 void
883 in6_ifdetach(struct ifnet *ifp)
884 {
885 	struct netmsg_base nmsg;
886 	struct lwkt_msg *lmsg = &nmsg.lmsg;
887 
888 	netmsg_init(&nmsg, NULL, &curthread->td_msgport, 0,
889 	    in6_ifdetach_dispatch);
890 	lmsg->u.ms_resultp = ifp;
891 	lwkt_domsg(netisr_cpuport(0), lmsg, 0);
892 }
893 
894 void
895 in6_get_tmpifid(struct ifnet *ifp, u_int8_t *retbuf, const u_int8_t *baseid,
896 		int generate)
897 {
898 	u_int8_t nullbuf[8];
899 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
900 
901 	bzero(nullbuf, sizeof(nullbuf));
902 	if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
903 		/* we've never created a random ID.  Create a new one. */
904 		generate = 1;
905 	}
906 
907 	if (generate) {
908 		bcopy(baseid, ndi->randomseed1, sizeof(ndi->randomseed1));
909 
910 		/* generate_tmp_ifid will update seedn and buf */
911 		generate_tmp_ifid(ndi->randomseed0, ndi->randomseed1,
912 				  ndi->randomid);
913 	}
914 	bcopy(ndi->randomid, retbuf, 8);
915 }
916 
917 static void
918 in6_tmpaddrtimer(void *arg __unused)
919 {
920 	struct lwkt_msg *lmsg = &in6_tmpaddrtimer_netmsg.lmsg;
921 
922 	KASSERT(mycpuid == 0, ("not on cpu0"));
923 	crit_enter();
924 	if (lmsg->ms_flags & MSGF_DONE)
925 		lwkt_sendmsg_oncpu(netisr_cpuport(0), lmsg);
926 	crit_exit();
927 }
928 
929 static void
930 in6_tmpaddrtimer_dispatch(netmsg_t nmsg)
931 {
932 	struct nd_ifinfo *ndi;
933 	u_int8_t nullbuf[8];
934 	struct ifnet *ifp;
935 
936 	KASSERT(&curthread->td_msgport == netisr_cpuport(0),
937 	    ("not in netisr0"));
938 
939 	crit_enter();
940 	lwkt_replymsg(&nmsg->lmsg, 0);  /* reply ASAP */
941 	crit_exit();
942 
943 	bzero(nullbuf, sizeof(nullbuf));
944 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
945 		if (ifp->if_afdata[AF_INET6] == NULL)
946 			continue;
947 		ndi = ND_IFINFO(ifp);
948 		if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
949 			/*
950 			 * We've been generating a random ID on this interface.
951 			 * Create a new one.
952 			 */
953 			generate_tmp_ifid(ndi->randomseed0,
954 					  ndi->randomseed1,
955 					  ndi->randomid);
956 		}
957 	}
958 
959 	callout_reset(&in6_tmpaddrtimer_ch,
960 		      (ip6_temp_preferred_lifetime - ip6_desync_factor -
961 		       ip6_temp_regen_advance) * hz,
962 		      in6_tmpaddrtimer, NULL);
963 }
964 
965 /*
966  * Timer for regeneranation of temporary addresses randomize ID
967  */
968 void
969 in6_tmpaddrtimer_init(void)
970 {
971 	callout_init_mp(&in6_tmpaddrtimer_ch);
972 	netmsg_init(&in6_tmpaddrtimer_netmsg, NULL, &netisr_adone_rport,
973 	    MSGF_PRIORITY, in6_tmpaddrtimer_dispatch);
974 	callout_reset_bycpu(&in6_tmpaddrtimer_ch,
975 	    (ip6_temp_preferred_lifetime - ip6_desync_factor -
976 	     ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, NULL, 0);
977 }
978