xref: /freebsd/sys/netinet6/in6_ifattach.c (revision 830940567b49bb0c08dfaed40418999e76616909)
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/jail.h>
41 #include <sys/kernel.h>
42 #include <sys/proc.h>
43 #include <sys/syslog.h>
44 #include <sys/md5.h>
45 
46 #include <net/if.h>
47 #include <net/if_dl.h>
48 #include <net/if_types.h>
49 #include <net/route.h>
50 #include <net/vnet.h>
51 
52 #include <netinet/in.h>
53 #include <netinet/in_var.h>
54 #include <netinet/if_ether.h>
55 #include <netinet/in_pcb.h>
56 #include <netinet/ip_var.h>
57 #include <netinet/udp.h>
58 #include <netinet/udp_var.h>
59 
60 #include <netinet/ip6.h>
61 #include <netinet6/ip6_var.h>
62 #include <netinet6/in6_var.h>
63 #include <netinet6/in6_pcb.h>
64 #include <netinet6/in6_ifattach.h>
65 #include <netinet6/ip6_var.h>
66 #include <netinet6/nd6.h>
67 #include <netinet6/mld6_var.h>
68 #include <netinet6/scope6_var.h>
69 
70 VNET_DEFINE(unsigned long, in6_maxmtu);
71 VNET_DEFINE(int, ip6_auto_linklocal);
72 VNET_DEFINE(struct callout, in6_tmpaddrtimer_ch);
73 
74 #define	V_in6_tmpaddrtimer_ch		VNET(in6_tmpaddrtimer_ch)
75 
76 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
77 #define	V_ripcbinfo			VNET(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_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 static void in6_purgemaddrs(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  * in6 - upper 64bits are preserved
105  */
106 static int
107 get_rand_ifid(struct ifnet *ifp, struct in6_addr *in6)
108 {
109 	MD5_CTX ctxt;
110 	struct prison *pr;
111 	u_int8_t digest[16];
112 	int hostnamelen;
113 
114 	pr = curthread->td_ucred->cr_prison;
115 	mtx_lock(&pr->pr_mtx);
116 	hostnamelen = strlen(pr->pr_hostname);
117 #if 0
118 	/* we need at least several letters as seed for ifid */
119 	if (hostnamelen < 3) {
120 		mtx_unlock(&pr->pr_mtx);
121 		return -1;
122 	}
123 #endif
124 
125 	/* generate 8 bytes of pseudo-random value. */
126 	bzero(&ctxt, sizeof(ctxt));
127 	MD5Init(&ctxt);
128 	MD5Update(&ctxt, pr->pr_hostname, hostnamelen);
129 	mtx_unlock(&pr->pr_mtx);
130 	MD5Final(digest, &ctxt);
131 
132 	/* assumes sizeof(digest) > sizeof(ifid) */
133 	bcopy(digest, &in6->s6_addr[8], 8);
134 
135 	/* make sure to set "u" bit to local, and "g" bit to individual. */
136 	in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
137 	in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
138 
139 	/* convert EUI64 into IPv6 interface identifier */
140 	EUI64_TO_IFID(in6);
141 
142 	return 0;
143 }
144 
145 static int
146 generate_tmp_ifid(u_int8_t *seed0, const u_int8_t *seed1, u_int8_t *ret)
147 {
148 	MD5_CTX ctxt;
149 	u_int8_t seed[16], digest[16], nullbuf[8];
150 	u_int32_t val32;
151 
152 	/* If there's no history, start with a random seed. */
153 	bzero(nullbuf, sizeof(nullbuf));
154 	if (bcmp(nullbuf, seed0, sizeof(nullbuf)) == 0) {
155 		int i;
156 
157 		for (i = 0; i < 2; i++) {
158 			val32 = arc4random();
159 			bcopy(&val32, seed + sizeof(val32) * i, sizeof(val32));
160 		}
161 	} else
162 		bcopy(seed0, seed, 8);
163 
164 	/* copy the right-most 64-bits of the given address */
165 	/* XXX assumption on the size of IFID */
166 	bcopy(seed1, &seed[8], 8);
167 
168 	if (0) {		/* for debugging purposes only */
169 		int i;
170 
171 		printf("generate_tmp_ifid: new randomized ID from: ");
172 		for (i = 0; i < 16; i++)
173 			printf("%02x", seed[i]);
174 		printf(" ");
175 	}
176 
177 	/* generate 16 bytes of pseudo-random value. */
178 	bzero(&ctxt, sizeof(ctxt));
179 	MD5Init(&ctxt);
180 	MD5Update(&ctxt, seed, sizeof(seed));
181 	MD5Final(digest, &ctxt);
182 
183 	/*
184 	 * RFC 3041 3.2.1. (3)
185 	 * Take the left-most 64-bits of the MD5 digest and set bit 6 (the
186 	 * left-most bit is numbered 0) to zero.
187 	 */
188 	bcopy(digest, ret, 8);
189 	ret[0] &= ~EUI64_UBIT;
190 
191 	/*
192 	 * XXX: we'd like to ensure that the generated value is not zero
193 	 * for simplicity.  If the caclculated digest happens to be zero,
194 	 * use a random non-zero value as the last resort.
195 	 */
196 	if (bcmp(nullbuf, ret, sizeof(nullbuf)) == 0) {
197 		nd6log((LOG_INFO,
198 		    "generate_tmp_ifid: computed MD5 value is zero.\n"));
199 
200 		val32 = arc4random();
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  * in6 - upper 64bits are preserved
229  */
230 int
231 in6_get_hw_ifid(struct ifnet *ifp, struct in6_addr *in6)
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 	IF_ADDR_LOCK(ifp);
242 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
243 		if (ifa->ifa_addr->sa_family != AF_LINK)
244 			continue;
245 		sdl = (struct sockaddr_dl *)ifa->ifa_addr;
246 		if (sdl == NULL)
247 			continue;
248 		if (sdl->sdl_alen == 0)
249 			continue;
250 
251 		goto found;
252 	}
253 	IF_ADDR_UNLOCK(ifp);
254 
255 	return -1;
256 
257 found:
258 	IF_ADDR_LOCK_ASSERT(ifp);
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_ISO88025:
267 	case IFT_ATM:
268 	case IFT_IEEE1394:
269 #ifdef IFT_IEEE80211
270 	case IFT_IEEE80211:
271 #endif
272 		/* IEEE802/EUI64 cases - what others? */
273 		/* IEEE1394 uses 16byte length address starting with EUI64 */
274 		if (addrlen > 8)
275 			addrlen = 8;
276 
277 		/* look at IEEE802/EUI64 only */
278 		if (addrlen != 8 && addrlen != 6) {
279 			IF_ADDR_UNLOCK(ifp);
280 			return -1;
281 		}
282 
283 		/*
284 		 * check for invalid MAC address - on bsdi, we see it a lot
285 		 * since wildboar configures all-zero MAC on pccard before
286 		 * card insertion.
287 		 */
288 		if (bcmp(addr, allzero, addrlen) == 0) {
289 			IF_ADDR_UNLOCK(ifp);
290 			return -1;
291 		}
292 		if (bcmp(addr, allone, addrlen) == 0) {
293 			IF_ADDR_UNLOCK(ifp);
294 			return -1;
295 		}
296 
297 		/* make EUI64 address */
298 		if (addrlen == 8)
299 			bcopy(addr, &in6->s6_addr[8], 8);
300 		else if (addrlen == 6) {
301 			in6->s6_addr[8] = addr[0];
302 			in6->s6_addr[9] = addr[1];
303 			in6->s6_addr[10] = addr[2];
304 			in6->s6_addr[11] = 0xff;
305 			in6->s6_addr[12] = 0xfe;
306 			in6->s6_addr[13] = addr[3];
307 			in6->s6_addr[14] = addr[4];
308 			in6->s6_addr[15] = addr[5];
309 		}
310 		break;
311 
312 	case IFT_ARCNET:
313 		if (addrlen != 1) {
314 			IF_ADDR_UNLOCK(ifp);
315 			return -1;
316 		}
317 		if (!addr[0]) {
318 			IF_ADDR_UNLOCK(ifp);
319 			return -1;
320 		}
321 
322 		bzero(&in6->s6_addr[8], 8);
323 		in6->s6_addr[15] = addr[0];
324 
325 		/*
326 		 * due to insufficient bitwidth, we mark it local.
327 		 */
328 		in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
329 		in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
330 		break;
331 
332 	case IFT_GIF:
333 #ifdef IFT_STF
334 	case IFT_STF:
335 #endif
336 		/*
337 		 * RFC2893 says: "SHOULD use IPv4 address as ifid source".
338 		 * however, IPv4 address is not very suitable as unique
339 		 * identifier source (can be renumbered).
340 		 * we don't do this.
341 		 */
342 		IF_ADDR_UNLOCK(ifp);
343 		return -1;
344 
345 	default:
346 		IF_ADDR_UNLOCK(ifp);
347 		return -1;
348 	}
349 
350 	/* sanity check: g bit must not indicate "group" */
351 	if (EUI64_GROUP(in6)) {
352 		IF_ADDR_UNLOCK(ifp);
353 		return -1;
354 	}
355 
356 	/* convert EUI64 into IPv6 interface identifier */
357 	EUI64_TO_IFID(in6);
358 
359 	/*
360 	 * sanity check: ifid must not be all zero, avoid conflict with
361 	 * subnet router anycast
362 	 */
363 	if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
364 	    bcmp(&in6->s6_addr[9], allzero, 7) == 0) {
365 		IF_ADDR_UNLOCK(ifp);
366 		return -1;
367 	}
368 
369 	IF_ADDR_UNLOCK(ifp);
370 	return 0;
371 }
372 
373 /*
374  * Get interface identifier for the specified interface.  If it is not
375  * available on ifp0, borrow interface identifier from other information
376  * sources.
377  *
378  * altifp - secondary EUI64 source
379  */
380 static int
381 get_ifid(struct ifnet *ifp0, struct ifnet *altifp,
382     struct in6_addr *in6)
383 {
384 	struct ifnet *ifp;
385 
386 	/* first, try to get it from the interface itself */
387 	if (in6_get_hw_ifid(ifp0, in6) == 0) {
388 		nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n",
389 		    if_name(ifp0)));
390 		goto success;
391 	}
392 
393 	/* try secondary EUI64 source. this basically is for ATM PVC */
394 	if (altifp && in6_get_hw_ifid(altifp, in6) == 0) {
395 		nd6log((LOG_DEBUG, "%s: got interface identifier from %s\n",
396 		    if_name(ifp0), if_name(altifp)));
397 		goto success;
398 	}
399 
400 	/* next, try to get it from some other hardware interface */
401 	IFNET_RLOCK();
402 	for (ifp = V_ifnet.tqh_first; ifp; ifp = ifp->if_list.tqe_next) {
403 		if (ifp == ifp0)
404 			continue;
405 		if (in6_get_hw_ifid(ifp, in6) != 0)
406 			continue;
407 
408 		/*
409 		 * to borrow ifid from other interface, ifid needs to be
410 		 * globally unique
411 		 */
412 		if (IFID_UNIVERSAL(in6)) {
413 			nd6log((LOG_DEBUG,
414 			    "%s: borrow interface identifier from %s\n",
415 			    if_name(ifp0), if_name(ifp)));
416 			IFNET_RUNLOCK();
417 			goto success;
418 		}
419 	}
420 	IFNET_RUNLOCK();
421 
422 	/* last resort: get from random number source */
423 	if (get_rand_ifid(ifp, in6) == 0) {
424 		nd6log((LOG_DEBUG,
425 		    "%s: interface identifier generated by random number\n",
426 		    if_name(ifp0)));
427 		goto success;
428 	}
429 
430 	printf("%s: failed to get interface identifier\n", if_name(ifp0));
431 	return -1;
432 
433 success:
434 	nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
435 	    if_name(ifp0), in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10],
436 	    in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13],
437 	    in6->s6_addr[14], in6->s6_addr[15]));
438 	return 0;
439 }
440 
441 /*
442  * altifp - secondary EUI64 source
443  */
444 static int
445 in6_ifattach_linklocal(struct ifnet *ifp, struct ifnet *altifp)
446 {
447 	struct in6_ifaddr *ia;
448 	struct in6_aliasreq ifra;
449 	struct nd_prefixctl pr0;
450 	int i, error;
451 
452 	/*
453 	 * configure link-local address.
454 	 */
455 	bzero(&ifra, sizeof(ifra));
456 
457 	/*
458 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
459 	 * for safety.
460 	 */
461 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
462 
463 	ifra.ifra_addr.sin6_family = AF_INET6;
464 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
465 	ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000);
466 	ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
467 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
468 		ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
469 		ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
470 	} else {
471 		if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) {
472 			nd6log((LOG_ERR,
473 			    "%s: no ifid available\n", if_name(ifp)));
474 			return (-1);
475 		}
476 	}
477 	if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL))
478 		return (-1);
479 
480 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
481 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
482 	ifra.ifra_prefixmask.sin6_addr = in6mask64;
483 	/* link-local addresses should NEVER expire. */
484 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
485 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
486 
487 	/*
488 	 * Now call in6_update_ifa() to do a bunch of procedures to configure
489 	 * a link-local address. We can set the 3rd argument to NULL, because
490 	 * we know there's no other link-local address on the interface
491 	 * and therefore we are adding one (instead of updating one).
492 	 */
493 	if ((error = in6_update_ifa(ifp, &ifra, NULL,
494 				    IN6_IFAUPDATE_DADDELAY)) != 0) {
495 		/*
496 		 * XXX: When the interface does not support IPv6, this call
497 		 * would fail in the SIOCSIFADDR ioctl.  I believe the
498 		 * notification is rather confusing in this case, so just
499 		 * suppress it.  (jinmei@kame.net 20010130)
500 		 */
501 		if (error != EAFNOSUPPORT)
502 			nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to "
503 			    "configure a link-local address on %s "
504 			    "(errno=%d)\n",
505 			    if_name(ifp), error));
506 		return (-1);
507 	}
508 
509 	ia = in6ifa_ifpforlinklocal(ifp, 0); /* ia must not be NULL */
510 #ifdef DIAGNOSTIC
511 	if (!ia) {
512 		panic("ia == NULL in in6_ifattach_linklocal");
513 		/* NOTREACHED */
514 	}
515 #endif
516 	ifa_free(&ia->ia_ifa);
517 
518 	/*
519 	 * Make the link-local prefix (fe80::%link/64) as on-link.
520 	 * Since we'd like to manage prefixes separately from addresses,
521 	 * we make an ND6 prefix structure for the link-local prefix,
522 	 * and add it to the prefix list as a never-expire prefix.
523 	 * XXX: this change might affect some existing code base...
524 	 */
525 	bzero(&pr0, sizeof(pr0));
526 	pr0.ndpr_ifp = ifp;
527 	/* this should be 64 at this moment. */
528 	pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
529 	pr0.ndpr_prefix = ifra.ifra_addr;
530 	/* apply the mask for safety. (nd6_prelist_add will apply it again) */
531 	for (i = 0; i < 4; i++) {
532 		pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
533 		    in6mask64.s6_addr32[i];
534 	}
535 	/*
536 	 * Initialize parameters.  The link-local prefix must always be
537 	 * on-link, and its lifetimes never expire.
538 	 */
539 	pr0.ndpr_raf_onlink = 1;
540 	pr0.ndpr_raf_auto = 1;	/* probably meaningless */
541 	pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
542 	pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
543 	/*
544 	 * Since there is no other link-local addresses, nd6_prefix_lookup()
545 	 * probably returns NULL.  However, we cannot always expect the result.
546 	 * For example, if we first remove the (only) existing link-local
547 	 * address, and then reconfigure another one, the prefix is still
548 	 * valid with referring to the old link-local address.
549 	 */
550 	if (nd6_prefix_lookup(&pr0) == NULL) {
551 		if ((error = nd6_prelist_add(&pr0, NULL, NULL)) != 0)
552 			return (error);
553 	}
554 
555 	return 0;
556 }
557 
558 /*
559  * ifp - must be IFT_LOOP
560  */
561 static int
562 in6_ifattach_loopback(struct ifnet *ifp)
563 {
564 	struct in6_aliasreq ifra;
565 	int error;
566 
567 	bzero(&ifra, sizeof(ifra));
568 
569 	/*
570 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
571 	 * for safety.
572 	 */
573 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
574 
575 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
576 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
577 	ifra.ifra_prefixmask.sin6_addr = in6mask128;
578 
579 	/*
580 	 * Always initialize ia_dstaddr (= broadcast address) to loopback
581 	 * address.  Follows IPv4 practice - see in_ifinit().
582 	 */
583 	ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
584 	ifra.ifra_dstaddr.sin6_family = AF_INET6;
585 	ifra.ifra_dstaddr.sin6_addr = in6addr_loopback;
586 
587 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
588 	ifra.ifra_addr.sin6_family = AF_INET6;
589 	ifra.ifra_addr.sin6_addr = in6addr_loopback;
590 
591 	/* the loopback  address should NEVER expire. */
592 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
593 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
594 
595 	/* we don't need to perform DAD on loopback interfaces. */
596 	ifra.ifra_flags |= IN6_IFF_NODAD;
597 
598 	/* skip registration to the prefix list. XXX should be temporary. */
599 	ifra.ifra_flags |= IN6_IFF_NOPFX;
600 
601 	/*
602 	 * We are sure that this is a newly assigned address, so we can set
603 	 * NULL to the 3rd arg.
604 	 */
605 	if ((error = in6_update_ifa(ifp, &ifra, NULL, 0)) != 0) {
606 		nd6log((LOG_ERR, "in6_ifattach_loopback: failed to configure "
607 		    "the loopback address on %s (errno=%d)\n",
608 		    if_name(ifp), error));
609 		return (-1);
610 	}
611 
612 	return 0;
613 }
614 
615 /*
616  * compute NI group address, based on the current hostname setting.
617  * see draft-ietf-ipngwg-icmp-name-lookup-* (04 and later).
618  *
619  * when ifp == NULL, the caller is responsible for filling scopeid.
620  */
621 int
622 in6_nigroup(struct ifnet *ifp, const char *name, int namelen,
623     struct in6_addr *in6)
624 {
625 	struct prison *pr;
626 	const char *p;
627 	u_char *q;
628 	MD5_CTX ctxt;
629 	u_int8_t digest[16];
630 	char l;
631 	char n[64];	/* a single label must not exceed 63 chars */
632 
633 	/*
634 	 * If no name is given and namelen is -1,
635 	 * we try to do the hostname lookup ourselves.
636 	 */
637 	if (!name && namelen == -1) {
638 		pr = curthread->td_ucred->cr_prison;
639 		mtx_lock(&pr->pr_mtx);
640 		name = pr->pr_hostname;
641 		namelen = strlen(name);
642 	} else
643 		pr = NULL;
644 	if (!name || !namelen) {
645 		if (pr != NULL)
646 			mtx_unlock(&pr->pr_mtx);
647 		return -1;
648 	}
649 
650 	p = name;
651 	while (p && *p && *p != '.' && p - name < namelen)
652 		p++;
653 	if (p == name || p - name > sizeof(n) - 1) {
654 		if (pr != NULL)
655 			mtx_unlock(&pr->pr_mtx);
656 		return -1;	/* label too long */
657 	}
658 	l = p - name;
659 	strncpy(n, name, l);
660 	if (pr != NULL)
661 		mtx_unlock(&pr->pr_mtx);
662 	n[(int)l] = '\0';
663 	for (q = n; *q; q++) {
664 		if ('A' <= *q && *q <= 'Z')
665 			*q = *q - 'A' + 'a';
666 	}
667 
668 	/* generate 8 bytes of pseudo-random value. */
669 	bzero(&ctxt, sizeof(ctxt));
670 	MD5Init(&ctxt);
671 	MD5Update(&ctxt, &l, sizeof(l));
672 	MD5Update(&ctxt, n, l);
673 	MD5Final(digest, &ctxt);
674 
675 	bzero(in6, sizeof(*in6));
676 	in6->s6_addr16[0] = IPV6_ADDR_INT16_MLL;
677 	in6->s6_addr8[11] = 2;
678 	bcopy(digest, &in6->s6_addr32[3], sizeof(in6->s6_addr32[3]));
679 	if (in6_setscope(in6, ifp, NULL))
680 		return (-1); /* XXX: should not fail */
681 
682 	return 0;
683 }
684 
685 /*
686  * XXX multiple loopback interface needs more care.  for instance,
687  * nodelocal address needs to be configured onto only one of them.
688  * XXX multiple link-local address case
689  *
690  * altifp - secondary EUI64 source
691  */
692 void
693 in6_ifattach(struct ifnet *ifp, struct ifnet *altifp)
694 {
695 	struct in6_ifaddr *ia;
696 	struct in6_addr in6;
697 
698 	/* some of the interfaces are inherently not IPv6 capable */
699 	switch (ifp->if_type) {
700 	case IFT_PFLOG:
701 	case IFT_PFSYNC:
702 	case IFT_CARP:
703 		return;
704 	}
705 
706 	/*
707 	 * quirks based on interface type
708 	 */
709 	switch (ifp->if_type) {
710 #ifdef IFT_STF
711 	case IFT_STF:
712 		/*
713 		 * 6to4 interface is a very special kind of beast.
714 		 * no multicast, no linklocal.  RFC2529 specifies how to make
715 		 * linklocals for 6to4 interface, but there's no use and
716 		 * it is rather harmful to have one.
717 		 */
718 		goto statinit;
719 #endif
720 	default:
721 		break;
722 	}
723 
724 	/*
725 	 * usually, we require multicast capability to the interface
726 	 */
727 	if ((ifp->if_flags & IFF_MULTICAST) == 0) {
728 		nd6log((LOG_INFO, "in6_ifattach: "
729 		    "%s is not multicast capable, IPv6 not enabled\n",
730 		    if_name(ifp)));
731 		return;
732 	}
733 
734 	/*
735 	 * assign loopback address for loopback interface.
736 	 * XXX multiple loopback interface case.
737 	 */
738 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
739 		struct ifaddr *ifa;
740 
741 		in6 = in6addr_loopback;
742 		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &in6);
743 		if (ifa == NULL) {
744 			if (in6_ifattach_loopback(ifp) != 0)
745 				return;
746 		} else
747 			ifa_free(ifa);
748 	}
749 
750 	/*
751 	 * assign a link-local address, if there's none.
752 	 */
753 	if (V_ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE) {
754 		ia = in6ifa_ifpforlinklocal(ifp, 0);
755 		if (ia == NULL) {
756 			if (in6_ifattach_linklocal(ifp, altifp) == 0) {
757 				/* linklocal address assigned */
758 			} else {
759 				/* failed to assign linklocal address. bark? */
760 			}
761 		} else
762 			ifa_free(&ia->ia_ifa);
763 	}
764 
765 #ifdef IFT_STF			/* XXX */
766 statinit:
767 #endif
768 
769 	/* update dynamically. */
770 	if (V_in6_maxmtu < ifp->if_mtu)
771 		V_in6_maxmtu = ifp->if_mtu;
772 }
773 
774 /*
775  * NOTE: in6_ifdetach() does not support loopback if at this moment.
776  * We don't need this function in bsdi, because interfaces are never removed
777  * from the ifnet list in bsdi.
778  */
779 void
780 in6_ifdetach(struct ifnet *ifp)
781 {
782 	struct in6_ifaddr *ia;
783 	struct ifaddr *ifa, *next;
784 	struct radix_node_head *rnh;
785 	struct rtentry *rt;
786 	short rtflags;
787 	struct sockaddr_in6 sin6;
788 	struct in6_multi_mship *imm;
789 
790 	/* remove neighbor management table */
791 	nd6_purge(ifp);
792 
793 	/* nuke any of IPv6 addresses we have */
794 	TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
795 		if (ifa->ifa_addr->sa_family != AF_INET6)
796 			continue;
797 		in6_purgeaddr(ifa);
798 	}
799 
800 	/* undo everything done by in6_ifattach(), just in case */
801 	TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
802 		if (ifa->ifa_addr->sa_family != AF_INET6
803 		 || !IN6_IS_ADDR_LINKLOCAL(&satosin6(&ifa->ifa_addr)->sin6_addr)) {
804 			continue;
805 		}
806 
807 		ia = (struct in6_ifaddr *)ifa;
808 
809 		/*
810 		 * leave from multicast groups we have joined for the interface
811 		 */
812 		while ((imm = ia->ia6_memberships.lh_first) != NULL) {
813 			LIST_REMOVE(imm, i6mm_chain);
814 			in6_leavegroup(imm);
815 		}
816 
817 		/* remove from the routing table */
818 		if ((ia->ia_flags & IFA_ROUTE) &&
819 		    (rt = rtalloc1((struct sockaddr *)&ia->ia_addr, 0, 0UL))) {
820 			rtflags = rt->rt_flags;
821 			RTFREE_LOCKED(rt);
822 			rtrequest(RTM_DELETE, (struct sockaddr *)&ia->ia_addr,
823 			    (struct sockaddr *)&ia->ia_addr,
824 			    (struct sockaddr *)&ia->ia_prefixmask,
825 			    rtflags, (struct rtentry **)0);
826 		}
827 
828 		/* remove from the linked list */
829 		IF_ADDR_LOCK(ifp);
830 		TAILQ_REMOVE(&ifp->if_addrhead, ifa, ifa_link);
831 		IF_ADDR_UNLOCK(ifp);
832 		ifa_free(ifa);				/* if_addrhead */
833 
834 		IN6_IFADDR_WLOCK();
835 		TAILQ_REMOVE(&V_in6_ifaddrhead, ia, ia_link);
836 		IN6_IFADDR_WUNLOCK();
837 		ifa_free(ifa);
838 	}
839 
840 	in6_pcbpurgeif0(&V_udbinfo, ifp);
841 	in6_pcbpurgeif0(&V_ripcbinfo, ifp);
842 	/* leave from all multicast groups joined */
843 	in6_purgemaddrs(ifp);
844 
845 	/*
846 	 * remove neighbor management table.  we call it twice just to make
847 	 * sure we nuke everything.  maybe we need just one call.
848 	 * XXX: since the first call did not release addresses, some prefixes
849 	 * might remain.  We should call nd6_purge() again to release the
850 	 * prefixes after removing all addresses above.
851 	 * (Or can we just delay calling nd6_purge until at this point?)
852 	 */
853 	nd6_purge(ifp);
854 
855 	/* remove route to link-local allnodes multicast (ff02::1) */
856 	bzero(&sin6, sizeof(sin6));
857 	sin6.sin6_len = sizeof(struct sockaddr_in6);
858 	sin6.sin6_family = AF_INET6;
859 	sin6.sin6_addr = in6addr_linklocal_allnodes;
860 	if (in6_setscope(&sin6.sin6_addr, ifp, NULL))
861 		/* XXX: should not fail */
862 		return;
863 	/* XXX grab lock first to avoid LOR */
864 	rnh = rt_tables_get_rnh(0, AF_INET6);
865 	if (rnh != NULL) {
866 		RADIX_NODE_HEAD_LOCK(rnh);
867 		rt = rtalloc1((struct sockaddr *)&sin6, 0, RTF_RNH_LOCKED);
868 		if (rt) {
869 			if (rt->rt_ifp == ifp)
870 				rtexpunge(rt);
871 			RTFREE_LOCKED(rt);
872 		}
873 		RADIX_NODE_HEAD_UNLOCK(rnh);
874 	}
875 }
876 
877 int
878 in6_get_tmpifid(struct ifnet *ifp, u_int8_t *retbuf,
879     const u_int8_t *baseid, int generate)
880 {
881 	u_int8_t nullbuf[8];
882 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
883 
884 	bzero(nullbuf, sizeof(nullbuf));
885 	if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
886 		/* we've never created a random ID.  Create a new one. */
887 		generate = 1;
888 	}
889 
890 	if (generate) {
891 		bcopy(baseid, ndi->randomseed1, sizeof(ndi->randomseed1));
892 
893 		/* generate_tmp_ifid will update seedn and buf */
894 		(void)generate_tmp_ifid(ndi->randomseed0, ndi->randomseed1,
895 		    ndi->randomid);
896 	}
897 	bcopy(ndi->randomid, retbuf, 8);
898 
899 	return (0);
900 }
901 
902 void
903 in6_tmpaddrtimer(void *arg)
904 {
905 	CURVNET_SET((struct vnet *) arg);
906 	struct nd_ifinfo *ndi;
907 	u_int8_t nullbuf[8];
908 	struct ifnet *ifp;
909 
910 	callout_reset(&V_in6_tmpaddrtimer_ch,
911 	    (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
912 	    V_ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, curvnet);
913 
914 	bzero(nullbuf, sizeof(nullbuf));
915 	for (ifp = TAILQ_FIRST(&V_ifnet); ifp;
916 	    ifp = TAILQ_NEXT(ifp, if_list)) {
917 		ndi = ND_IFINFO(ifp);
918 		if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
919 			/*
920 			 * We've been generating a random ID on this interface.
921 			 * Create a new one.
922 			 */
923 			(void)generate_tmp_ifid(ndi->randomseed0,
924 			    ndi->randomseed1, ndi->randomid);
925 		}
926 	}
927 
928 	CURVNET_RESTORE();
929 }
930 
931 static void
932 in6_purgemaddrs(struct ifnet *ifp)
933 {
934 	LIST_HEAD(,in6_multi)	 purgeinms;
935 	struct in6_multi	*inm, *tinm;
936 	struct ifmultiaddr	*ifma;
937 
938 	LIST_INIT(&purgeinms);
939 	IN6_MULTI_LOCK();
940 
941 	/*
942 	 * Extract list of in6_multi associated with the detaching ifp
943 	 * which the PF_INET6 layer is about to release.
944 	 * We need to do this as IF_ADDR_LOCK() may be re-acquired
945 	 * by code further down.
946 	 */
947 	IF_ADDR_LOCK(ifp);
948 	TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
949 		if (ifma->ifma_addr->sa_family != AF_INET6 ||
950 		    ifma->ifma_protospec == NULL)
951 			continue;
952 		inm = (struct in6_multi *)ifma->ifma_protospec;
953 		LIST_INSERT_HEAD(&purgeinms, inm, in6m_entry);
954 	}
955 	IF_ADDR_UNLOCK(ifp);
956 
957 	LIST_FOREACH_SAFE(inm, &purgeinms, in6m_entry, tinm) {
958 		LIST_REMOVE(inm, in6m_entry);
959 		in6m_release_locked(inm);
960 	}
961 	mld_ifdetach(ifp);
962 
963 	IN6_MULTI_UNLOCK();
964 }
965