xref: /freebsd/sys/netinet6/in6_ifattach.c (revision b3aaa0cc21c63d388230c7ef2a80abd631ff20d5)
1 /*-
2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the project nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	$KAME: in6_ifattach.c,v 1.118 2001/05/24 07:44:00 itojun Exp $
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/malloc.h>
38 #include <sys/socket.h>
39 #include <sys/sockio.h>
40 #include <sys/kernel.h>
41 #include <sys/syslog.h>
42 #include <sys/md5.h>
43 #include <sys/vimage.h>
44 
45 #include <net/if.h>
46 #include <net/if_dl.h>
47 #include <net/if_types.h>
48 #include <net/route.h>
49 #include <net/vnet.h>
50 
51 #include <netinet/in.h>
52 #include <netinet/in_var.h>
53 #include <netinet/if_ether.h>
54 #include <netinet/in_pcb.h>
55 #include <netinet/vinet.h>
56 
57 #include <netinet/ip6.h>
58 #include <netinet6/ip6_var.h>
59 #include <netinet6/in6_var.h>
60 #include <netinet6/in6_pcb.h>
61 #include <netinet6/in6_ifattach.h>
62 #include <netinet6/ip6_var.h>
63 #include <netinet6/nd6.h>
64 #include <netinet6/scope6_var.h>
65 #include <netinet6/vinet6.h>
66 
67 #ifdef VIMAGE_GLOBALS
68 unsigned long in6_maxmtu;
69 int ip6_auto_linklocal;
70 struct callout in6_tmpaddrtimer_ch;
71 extern struct inpcbinfo ripcbinfo;
72 #endif
73 
74 static int get_rand_ifid(struct ifnet *, struct in6_addr *);
75 static int generate_tmp_ifid(u_int8_t *, const u_int8_t *, u_int8_t *);
76 static int get_ifid(struct ifnet *, struct ifnet *, struct in6_addr *);
77 static int in6_ifattach_linklocal(struct ifnet *, struct ifnet *);
78 static int in6_ifattach_loopback(struct ifnet *);
79 static void in6_purgemaddrs(struct ifnet *);
80 
81 #define EUI64_GBIT	0x01
82 #define EUI64_UBIT	0x02
83 #define EUI64_TO_IFID(in6)	do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (0)
84 #define EUI64_GROUP(in6)	((in6)->s6_addr[8] & EUI64_GBIT)
85 #define EUI64_INDIVIDUAL(in6)	(!EUI64_GROUP(in6))
86 #define EUI64_LOCAL(in6)	((in6)->s6_addr[8] & EUI64_UBIT)
87 #define EUI64_UNIVERSAL(in6)	(!EUI64_LOCAL(in6))
88 
89 #define IFID_LOCAL(in6)		(!EUI64_LOCAL(in6))
90 #define IFID_UNIVERSAL(in6)	(!EUI64_UNIVERSAL(in6))
91 
92 /*
93  * Generate a last-resort interface identifier, when the machine has no
94  * IEEE802/EUI64 address sources.
95  * The goal here is to get an interface identifier that is
96  * (1) random enough and (2) does not change across reboot.
97  * We currently use MD5(hostname) for it.
98  *
99  * in6 - upper 64bits are preserved
100  */
101 static int
102 get_rand_ifid(struct ifnet *ifp, struct in6_addr *in6)
103 {
104 	INIT_VPROCG(TD_TO_VPROCG(curthread)); /* XXX V_hostname needs this */
105 	MD5_CTX ctxt;
106 	u_int8_t digest[16];
107 	int hostnamelen;
108 
109 	mtx_lock(&hostname_mtx);
110 	hostnamelen = strlen(V_hostname);
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, V_hostname, hostnamelen);
121 	mtx_unlock(&hostname_mtx);
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 	INIT_VNET_INET6(curvnet);
141 	MD5_CTX ctxt;
142 	u_int8_t seed[16], digest[16], nullbuf[8];
143 	u_int32_t val32;
144 
145 	/* If there's no history, 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 			val32 = arc4random();
152 			bcopy(&val32, seed + sizeof(val32) * i, sizeof(val32));
153 		}
154 	} else
155 		bcopy(seed0, seed, 8);
156 
157 	/* copy the right-most 64-bits of the given address */
158 	/* XXX assumption on the size of IFID */
159 	bcopy(seed1, &seed[8], 8);
160 
161 	if (0) {		/* for debugging purposes only */
162 		int i;
163 
164 		printf("generate_tmp_ifid: new randomized ID from: ");
165 		for (i = 0; i < 16; i++)
166 			printf("%02x", seed[i]);
167 		printf(" ");
168 	}
169 
170 	/* generate 16 bytes of pseudo-random value. */
171 	bzero(&ctxt, sizeof(ctxt));
172 	MD5Init(&ctxt);
173 	MD5Update(&ctxt, seed, sizeof(seed));
174 	MD5Final(digest, &ctxt);
175 
176 	/*
177 	 * RFC 3041 3.2.1. (3)
178 	 * Take the left-most 64-bits of the MD5 digest and set bit 6 (the
179 	 * left-most bit is numbered 0) to zero.
180 	 */
181 	bcopy(digest, ret, 8);
182 	ret[0] &= ~EUI64_UBIT;
183 
184 	/*
185 	 * XXX: we'd like to ensure that the generated value is not zero
186 	 * for simplicity.  If the caclculated digest happens to be zero,
187 	 * use a random non-zero value as the last resort.
188 	 */
189 	if (bcmp(nullbuf, ret, sizeof(nullbuf)) == 0) {
190 		nd6log((LOG_INFO,
191 		    "generate_tmp_ifid: computed MD5 value is zero.\n"));
192 
193 		val32 = arc4random();
194 		val32 = 1 + (val32 % (0xffffffff - 1));
195 	}
196 
197 	/*
198 	 * RFC 3041 3.2.1. (4)
199 	 * Take the rightmost 64-bits of the MD5 digest and save them in
200 	 * stable storage as the history value to be used in the next
201 	 * iteration of the algorithm.
202 	 */
203 	bcopy(&digest[8], seed0, 8);
204 
205 	if (0) {		/* for debugging purposes only */
206 		int i;
207 
208 		printf("to: ");
209 		for (i = 0; i < 16; i++)
210 			printf("%02x", digest[i]);
211 		printf("\n");
212 	}
213 
214 	return 0;
215 }
216 
217 /*
218  * Get interface identifier for the specified interface.
219  * XXX assumes single sockaddr_dl (AF_LINK address) per an interface
220  *
221  * in6 - upper 64bits are preserved
222  */
223 int
224 in6_get_hw_ifid(struct ifnet *ifp, struct in6_addr *in6)
225 {
226 	struct ifaddr *ifa;
227 	struct sockaddr_dl *sdl;
228 	u_int8_t *addr;
229 	size_t addrlen;
230 	static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
231 	static u_int8_t allone[8] =
232 		{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
233 
234 	for (ifa = ifp->if_addrlist.tqh_first;
235 	     ifa;
236 	     ifa = ifa->ifa_list.tqe_next) {
237 		if (ifa->ifa_addr->sa_family != AF_LINK)
238 			continue;
239 		sdl = (struct sockaddr_dl *)ifa->ifa_addr;
240 		if (sdl == NULL)
241 			continue;
242 		if (sdl->sdl_alen == 0)
243 			continue;
244 
245 		goto found;
246 	}
247 
248 	return -1;
249 
250 found:
251 	addr = LLADDR(sdl);
252 	addrlen = sdl->sdl_alen;
253 
254 	/* get EUI64 */
255 	switch (ifp->if_type) {
256 	case IFT_ETHER:
257 	case IFT_FDDI:
258 	case IFT_ISO88025:
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 
298 	case IFT_ARCNET:
299 		if (addrlen != 1)
300 			return -1;
301 		if (!addr[0])
302 			return -1;
303 
304 		bzero(&in6->s6_addr[8], 8);
305 		in6->s6_addr[15] = addr[0];
306 
307 		/*
308 		 * due to insufficient bitwidth, we mark it local.
309 		 */
310 		in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
311 		in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
312 		break;
313 
314 	case IFT_GIF:
315 #ifdef IFT_STF
316 	case IFT_STF:
317 #endif
318 		/*
319 		 * RFC2893 says: "SHOULD use IPv4 address as ifid source".
320 		 * however, IPv4 address is not very suitable as unique
321 		 * identifier source (can be renumbered).
322 		 * we don't do this.
323 		 */
324 		return -1;
325 
326 	default:
327 		return -1;
328 	}
329 
330 	/* sanity check: g bit must not indicate "group" */
331 	if (EUI64_GROUP(in6))
332 		return -1;
333 
334 	/* convert EUI64 into IPv6 interface identifier */
335 	EUI64_TO_IFID(in6);
336 
337 	/*
338 	 * sanity check: ifid must not be all zero, avoid conflict with
339 	 * subnet router anycast
340 	 */
341 	if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
342 	    bcmp(&in6->s6_addr[9], allzero, 7) == 0) {
343 		return -1;
344 	}
345 
346 	return 0;
347 }
348 
349 /*
350  * Get interface identifier for the specified interface.  If it is not
351  * available on ifp0, borrow interface identifier from other information
352  * sources.
353  *
354  * altifp - secondary EUI64 source
355  */
356 static int
357 get_ifid(struct ifnet *ifp0, struct ifnet *altifp,
358     struct in6_addr *in6)
359 {
360 	INIT_VNET_NET(ifp0->if_vnet);
361 	INIT_VNET_INET6(ifp0->if_vnet);
362 	struct ifnet *ifp;
363 
364 	/* first, try to get it from the interface itself */
365 	if (in6_get_hw_ifid(ifp0, in6) == 0) {
366 		nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n",
367 		    if_name(ifp0)));
368 		goto success;
369 	}
370 
371 	/* try secondary EUI64 source. this basically is for ATM PVC */
372 	if (altifp && in6_get_hw_ifid(altifp, in6) == 0) {
373 		nd6log((LOG_DEBUG, "%s: got interface identifier from %s\n",
374 		    if_name(ifp0), if_name(altifp)));
375 		goto success;
376 	}
377 
378 	/* next, try to get it from some other hardware interface */
379 	IFNET_RLOCK();
380 	for (ifp = V_ifnet.tqh_first; ifp; ifp = ifp->if_list.tqe_next) {
381 		if (ifp == ifp0)
382 			continue;
383 		if (in6_get_hw_ifid(ifp, in6) != 0)
384 			continue;
385 
386 		/*
387 		 * to borrow ifid from other interface, ifid needs to be
388 		 * globally unique
389 		 */
390 		if (IFID_UNIVERSAL(in6)) {
391 			nd6log((LOG_DEBUG,
392 			    "%s: borrow interface identifier from %s\n",
393 			    if_name(ifp0), if_name(ifp)));
394 			IFNET_RUNLOCK();
395 			goto success;
396 		}
397 	}
398 	IFNET_RUNLOCK();
399 
400 	/* last resort: get from random number source */
401 	if (get_rand_ifid(ifp, in6) == 0) {
402 		nd6log((LOG_DEBUG,
403 		    "%s: interface identifier generated by random number\n",
404 		    if_name(ifp0)));
405 		goto success;
406 	}
407 
408 	printf("%s: failed to get interface identifier\n", if_name(ifp0));
409 	return -1;
410 
411 success:
412 	nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
413 	    if_name(ifp0), in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10],
414 	    in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13],
415 	    in6->s6_addr[14], in6->s6_addr[15]));
416 	return 0;
417 }
418 
419 /*
420  * altifp - secondary EUI64 source
421  */
422 static int
423 in6_ifattach_linklocal(struct ifnet *ifp, struct ifnet *altifp)
424 {
425 	INIT_VNET_INET6(curvnet);
426 	struct in6_ifaddr *ia;
427 	struct in6_aliasreq ifra;
428 	struct nd_prefixctl pr0;
429 	int i, error;
430 
431 	/*
432 	 * configure link-local address.
433 	 */
434 	bzero(&ifra, sizeof(ifra));
435 
436 	/*
437 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
438 	 * for safety.
439 	 */
440 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
441 
442 	ifra.ifra_addr.sin6_family = AF_INET6;
443 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
444 	ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000);
445 	ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
446 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
447 		ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
448 		ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
449 	} else {
450 		if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) {
451 			nd6log((LOG_ERR,
452 			    "%s: no ifid available\n", if_name(ifp)));
453 			return (-1);
454 		}
455 	}
456 	if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL))
457 		return (-1);
458 
459 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
460 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
461 	ifra.ifra_prefixmask.sin6_addr = in6mask64;
462 	/* link-local addresses should NEVER expire. */
463 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
464 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
465 
466 	/*
467 	 * Now call in6_update_ifa() to do a bunch of procedures to configure
468 	 * a link-local address. We can set the 3rd argument to NULL, because
469 	 * we know there's no other link-local address on the interface
470 	 * and therefore we are adding one (instead of updating one).
471 	 */
472 	if ((error = in6_update_ifa(ifp, &ifra, NULL,
473 				    IN6_IFAUPDATE_DADDELAY)) != 0) {
474 		/*
475 		 * XXX: When the interface does not support IPv6, this call
476 		 * would fail in the SIOCSIFADDR ioctl.  I believe the
477 		 * notification is rather confusing in this case, so just
478 		 * suppress it.  (jinmei@kame.net 20010130)
479 		 */
480 		if (error != EAFNOSUPPORT)
481 			nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to "
482 			    "configure a link-local address on %s "
483 			    "(errno=%d)\n",
484 			    if_name(ifp), error));
485 		return (-1);
486 	}
487 
488 	ia = in6ifa_ifpforlinklocal(ifp, 0); /* ia must not be NULL */
489 #ifdef DIAGNOSTIC
490 	if (!ia) {
491 		panic("ia == NULL in in6_ifattach_linklocal");
492 		/* NOTREACHED */
493 	}
494 #endif
495 
496 	/*
497 	 * Make the link-local prefix (fe80::%link/64) as on-link.
498 	 * Since we'd like to manage prefixes separately from addresses,
499 	 * we make an ND6 prefix structure for the link-local prefix,
500 	 * and add it to the prefix list as a never-expire prefix.
501 	 * XXX: this change might affect some existing code base...
502 	 */
503 	bzero(&pr0, sizeof(pr0));
504 	pr0.ndpr_ifp = ifp;
505 	/* this should be 64 at this moment. */
506 	pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
507 	pr0.ndpr_prefix = ifra.ifra_addr;
508 	/* apply the mask for safety. (nd6_prelist_add will apply it again) */
509 	for (i = 0; i < 4; i++) {
510 		pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
511 		    in6mask64.s6_addr32[i];
512 	}
513 	/*
514 	 * Initialize parameters.  The link-local prefix must always be
515 	 * on-link, and its lifetimes never expire.
516 	 */
517 	pr0.ndpr_raf_onlink = 1;
518 	pr0.ndpr_raf_auto = 1;	/* probably meaningless */
519 	pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
520 	pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
521 	/*
522 	 * Since there is no other link-local addresses, nd6_prefix_lookup()
523 	 * probably returns NULL.  However, we cannot always expect the result.
524 	 * For example, if we first remove the (only) existing link-local
525 	 * address, and then reconfigure another one, the prefix is still
526 	 * valid with referring to the old link-local address.
527 	 */
528 	if (nd6_prefix_lookup(&pr0) == NULL) {
529 		if ((error = nd6_prelist_add(&pr0, NULL, NULL)) != 0)
530 			return (error);
531 	}
532 
533 	return 0;
534 }
535 
536 /*
537  * ifp - must be IFT_LOOP
538  */
539 static int
540 in6_ifattach_loopback(struct ifnet *ifp)
541 {
542 	INIT_VNET_INET6(curvnet);
543 	struct in6_aliasreq ifra;
544 	int error;
545 
546 	bzero(&ifra, sizeof(ifra));
547 
548 	/*
549 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
550 	 * for safety.
551 	 */
552 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
553 
554 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
555 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
556 	ifra.ifra_prefixmask.sin6_addr = in6mask128;
557 
558 	/*
559 	 * Always initialize ia_dstaddr (= broadcast address) to loopback
560 	 * address.  Follows IPv4 practice - see in_ifinit().
561 	 */
562 	ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
563 	ifra.ifra_dstaddr.sin6_family = AF_INET6;
564 	ifra.ifra_dstaddr.sin6_addr = in6addr_loopback;
565 
566 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
567 	ifra.ifra_addr.sin6_family = AF_INET6;
568 	ifra.ifra_addr.sin6_addr = in6addr_loopback;
569 
570 	/* the loopback  address should NEVER expire. */
571 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
572 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
573 
574 	/* we don't need to perform DAD on loopback interfaces. */
575 	ifra.ifra_flags |= IN6_IFF_NODAD;
576 
577 	/* skip registration to the prefix list. XXX should be temporary. */
578 	ifra.ifra_flags |= IN6_IFF_NOPFX;
579 
580 	/*
581 	 * We are sure that this is a newly assigned address, so we can set
582 	 * NULL to the 3rd arg.
583 	 */
584 	if ((error = in6_update_ifa(ifp, &ifra, NULL, 0)) != 0) {
585 		nd6log((LOG_ERR, "in6_ifattach_loopback: failed to configure "
586 		    "the loopback address on %s (errno=%d)\n",
587 		    if_name(ifp), error));
588 		return (-1);
589 	}
590 
591 	return 0;
592 }
593 
594 /*
595  * compute NI group address, based on the current hostname setting.
596  * see draft-ietf-ipngwg-icmp-name-lookup-* (04 and later).
597  *
598  * when ifp == NULL, the caller is responsible for filling scopeid.
599  */
600 int
601 in6_nigroup(struct ifnet *ifp, const char *name, int namelen,
602     struct in6_addr *in6)
603 {
604 	const char *p;
605 	u_char *q;
606 	MD5_CTX ctxt;
607 	u_int8_t digest[16];
608 	char l;
609 	char n[64];	/* a single label must not exceed 63 chars */
610 
611 	if (!namelen || !name)
612 		return -1;
613 
614 	p = name;
615 	while (p && *p && *p != '.' && p - name < namelen)
616 		p++;
617 	if (p - name > sizeof(n) - 1)
618 		return -1;	/* label too long */
619 	l = p - name;
620 	strncpy(n, name, l);
621 	n[(int)l] = '\0';
622 	for (q = n; *q; q++) {
623 		if ('A' <= *q && *q <= 'Z')
624 			*q = *q - 'A' + 'a';
625 	}
626 
627 	/* generate 8 bytes of pseudo-random value. */
628 	bzero(&ctxt, sizeof(ctxt));
629 	MD5Init(&ctxt);
630 	MD5Update(&ctxt, &l, sizeof(l));
631 	MD5Update(&ctxt, n, l);
632 	MD5Final(digest, &ctxt);
633 
634 	bzero(in6, sizeof(*in6));
635 	in6->s6_addr16[0] = IPV6_ADDR_INT16_MLL;
636 	in6->s6_addr8[11] = 2;
637 	bcopy(digest, &in6->s6_addr32[3], sizeof(in6->s6_addr32[3]));
638 	if (in6_setscope(in6, ifp, NULL))
639 		return (-1); /* XXX: should not fail */
640 
641 	return 0;
642 }
643 
644 /*
645  * XXX multiple loopback interface needs more care.  for instance,
646  * nodelocal address needs to be configured onto only one of them.
647  * XXX multiple link-local address case
648  *
649  * altifp - secondary EUI64 source
650  */
651 void
652 in6_ifattach(struct ifnet *ifp, struct ifnet *altifp)
653 {
654 	INIT_VNET_INET6(ifp->if_vnet);
655 	struct in6_ifaddr *ia;
656 	struct in6_addr in6;
657 
658 	/* some of the interfaces are inherently not IPv6 capable */
659 	switch (ifp->if_type) {
660 	case IFT_PFLOG:
661 	case IFT_PFSYNC:
662 	case IFT_CARP:
663 		return;
664 	}
665 
666 	/*
667 	 * quirks based on interface type
668 	 */
669 	switch (ifp->if_type) {
670 #ifdef IFT_STF
671 	case IFT_STF:
672 		/*
673 		 * 6to4 interface is a very special kind of beast.
674 		 * no multicast, no linklocal.  RFC2529 specifies how to make
675 		 * linklocals for 6to4 interface, but there's no use and
676 		 * it is rather harmful to have one.
677 		 */
678 		goto statinit;
679 #endif
680 	default:
681 		break;
682 	}
683 
684 	/*
685 	 * usually, we require multicast capability to the interface
686 	 */
687 	if ((ifp->if_flags & IFF_MULTICAST) == 0) {
688 		nd6log((LOG_INFO, "in6_ifattach: "
689 		    "%s is not multicast capable, IPv6 not enabled\n",
690 		    if_name(ifp)));
691 		return;
692 	}
693 
694 	/*
695 	 * assign loopback address for loopback interface.
696 	 * XXX multiple loopback interface case.
697 	 */
698 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
699 		in6 = in6addr_loopback;
700 		if (in6ifa_ifpwithaddr(ifp, &in6) == NULL) {
701 			if (in6_ifattach_loopback(ifp) != 0)
702 				return;
703 		}
704 	}
705 
706 	/*
707 	 * assign a link-local address, if there's none.
708 	 */
709 	if (V_ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE) {
710 		ia = in6ifa_ifpforlinklocal(ifp, 0);
711 		if (ia == NULL) {
712 			if (in6_ifattach_linklocal(ifp, altifp) == 0) {
713 				/* linklocal address assigned */
714 			} else {
715 				/* failed to assign linklocal address. bark? */
716 			}
717 		}
718 	}
719 
720 #ifdef IFT_STF			/* XXX */
721 statinit:
722 #endif
723 
724 	/* update dynamically. */
725 	if (V_in6_maxmtu < ifp->if_mtu)
726 		V_in6_maxmtu = ifp->if_mtu;
727 }
728 
729 /*
730  * NOTE: in6_ifdetach() does not support loopback if at this moment.
731  * We don't need this function in bsdi, because interfaces are never removed
732  * from the ifnet list in bsdi.
733  */
734 void
735 in6_ifdetach(struct ifnet *ifp)
736 {
737 	INIT_VNET_NET(ifp->if_vnet);
738 	INIT_VNET_INET(ifp->if_vnet);
739 	INIT_VNET_INET6(ifp->if_vnet);
740 	struct in6_ifaddr *ia, *oia;
741 	struct ifaddr *ifa, *next;
742 	struct rtentry *rt;
743 	short rtflags;
744 	struct sockaddr_in6 sin6;
745 	struct in6_multi_mship *imm;
746 
747 	/* remove neighbor management table */
748 	nd6_purge(ifp);
749 
750 	/* nuke any of IPv6 addresses we have */
751 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = next) {
752 		next = ifa->ifa_list.tqe_next;
753 		if (ifa->ifa_addr->sa_family != AF_INET6)
754 			continue;
755 		in6_purgeaddr(ifa);
756 	}
757 
758 	/* undo everything done by in6_ifattach(), just in case */
759 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = next) {
760 		next = ifa->ifa_list.tqe_next;
761 
762 		if (ifa->ifa_addr->sa_family != AF_INET6
763 		 || !IN6_IS_ADDR_LINKLOCAL(&satosin6(&ifa->ifa_addr)->sin6_addr)) {
764 			continue;
765 		}
766 
767 		ia = (struct in6_ifaddr *)ifa;
768 
769 		/*
770 		 * leave from multicast groups we have joined for the interface
771 		 */
772 		while ((imm = ia->ia6_memberships.lh_first) != NULL) {
773 			LIST_REMOVE(imm, i6mm_chain);
774 			in6_leavegroup(imm);
775 		}
776 
777 		/* remove from the routing table */
778 		if ((ia->ia_flags & IFA_ROUTE) &&
779 		    (rt = rtalloc1((struct sockaddr *)&ia->ia_addr, 0, 0UL))) {
780 			rtflags = rt->rt_flags;
781 			RTFREE_LOCKED(rt);
782 			rtrequest(RTM_DELETE, (struct sockaddr *)&ia->ia_addr,
783 			    (struct sockaddr *)&ia->ia_addr,
784 			    (struct sockaddr *)&ia->ia_prefixmask,
785 			    rtflags, (struct rtentry **)0);
786 		}
787 
788 		/* remove from the linked list */
789 		TAILQ_REMOVE(&ifp->if_addrlist, (struct ifaddr *)ia, ifa_list);
790 		IFAFREE(&ia->ia_ifa);
791 
792 		/* also remove from the IPv6 address chain(itojun&jinmei) */
793 		oia = ia;
794 		if (oia == (ia = V_in6_ifaddr))
795 			V_in6_ifaddr = ia->ia_next;
796 		else {
797 			while (ia->ia_next && (ia->ia_next != oia))
798 				ia = ia->ia_next;
799 			if (ia->ia_next)
800 				ia->ia_next = oia->ia_next;
801 			else {
802 				nd6log((LOG_ERR,
803 				    "%s: didn't unlink in6ifaddr from list\n",
804 				    if_name(ifp)));
805 			}
806 		}
807 
808 		IFAFREE(&oia->ia_ifa);
809 	}
810 
811 	in6_pcbpurgeif0(&V_udbinfo, ifp);
812 	in6_pcbpurgeif0(&V_ripcbinfo, ifp);
813 	/* leave from all multicast groups joined */
814 	in6_purgemaddrs(ifp);
815 
816 	/*
817 	 * remove neighbor management table.  we call it twice just to make
818 	 * sure we nuke everything.  maybe we need just one call.
819 	 * XXX: since the first call did not release addresses, some prefixes
820 	 * might remain.  We should call nd6_purge() again to release the
821 	 * prefixes after removing all addresses above.
822 	 * (Or can we just delay calling nd6_purge until at this point?)
823 	 */
824 	nd6_purge(ifp);
825 
826 	/* remove route to link-local allnodes multicast (ff02::1) */
827 	bzero(&sin6, sizeof(sin6));
828 	sin6.sin6_len = sizeof(struct sockaddr_in6);
829 	sin6.sin6_family = AF_INET6;
830 	sin6.sin6_addr = in6addr_linklocal_allnodes;
831 	if (in6_setscope(&sin6.sin6_addr, ifp, NULL))
832 		/* XXX: should not fail */
833 		return;
834 	/* XXX grab lock first to avoid LOR */
835 	if (V_rt_tables[0][AF_INET6] != NULL) {
836 		RADIX_NODE_HEAD_LOCK(V_rt_tables[0][AF_INET6]);
837 		rt = rtalloc1((struct sockaddr *)&sin6, 0, RTF_RNH_LOCKED);
838 		if (rt) {
839 			if (rt->rt_ifp == ifp)
840 				rtexpunge(rt);
841 			RTFREE_LOCKED(rt);
842 		}
843 		RADIX_NODE_HEAD_UNLOCK(V_rt_tables[0][AF_INET6]);
844 	}
845 }
846 
847 int
848 in6_get_tmpifid(struct ifnet *ifp, u_int8_t *retbuf,
849     const u_int8_t *baseid, int generate)
850 {
851 	u_int8_t nullbuf[8];
852 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
853 
854 	bzero(nullbuf, sizeof(nullbuf));
855 	if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
856 		/* we've never created a random ID.  Create a new one. */
857 		generate = 1;
858 	}
859 
860 	if (generate) {
861 		bcopy(baseid, ndi->randomseed1, sizeof(ndi->randomseed1));
862 
863 		/* generate_tmp_ifid will update seedn and buf */
864 		(void)generate_tmp_ifid(ndi->randomseed0, ndi->randomseed1,
865 		    ndi->randomid);
866 	}
867 	bcopy(ndi->randomid, retbuf, 8);
868 
869 	return (0);
870 }
871 
872 void
873 in6_tmpaddrtimer(void *ignored_arg)
874 {
875 	INIT_VNET_NET(curvnet);
876 	INIT_VNET_INET6(curvnet);
877 	struct nd_ifinfo *ndi;
878 	u_int8_t nullbuf[8];
879 	struct ifnet *ifp;
880 
881 	callout_reset(&V_in6_tmpaddrtimer_ch,
882 	    (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
883 	    V_ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, NULL);
884 
885 	bzero(nullbuf, sizeof(nullbuf));
886 	for (ifp = TAILQ_FIRST(&V_ifnet); ifp;
887 	    ifp = TAILQ_NEXT(ifp, if_list)) {
888 		ndi = ND_IFINFO(ifp);
889 		if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
890 			/*
891 			 * We've been generating a random ID on this interface.
892 			 * Create a new one.
893 			 */
894 			(void)generate_tmp_ifid(ndi->randomseed0,
895 			    ndi->randomseed1, ndi->randomid);
896 		}
897 	}
898 
899 }
900 
901 static void
902 in6_purgemaddrs(struct ifnet *ifp)
903 {
904 	struct in6_multi *in6m;
905 	struct in6_multi *oin6m;
906 
907 	IFF_LOCKGIANT(ifp);
908 	LIST_FOREACH_SAFE(in6m, &in6_multihead, in6m_entry, oin6m) {
909 		if (in6m->in6m_ifp == ifp)
910 			in6_delmulti(in6m);
911 	}
912 	IFF_UNLOCKGIANT(ifp);
913 }
914