xref: /netbsd-src/sys/netinet6/in6_ifattach.c (revision c38e7cc395b1472a774ff828e46123de44c628e9)
1 /*	$NetBSD: in6_ifattach.c,v 1.115 2018/05/01 07:21:39 maxv Exp $	*/
2 /*	$KAME: in6_ifattach.c,v 1.124 2001/07/18 08:32:51 jinmei 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/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: in6_ifattach.c,v 1.115 2018/05/01 07:21:39 maxv Exp $");
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/kmem.h>
39 #include <sys/socket.h>
40 #include <sys/sockio.h>
41 #include <sys/kernel.h>
42 #include <sys/syslog.h>
43 #include <sys/md5.h>
44 #include <sys/socketvar.h>
45 #include <sys/cprng.h>
46 
47 #include <net/if.h>
48 #include <net/if_dl.h>
49 #include <net/if_types.h>
50 #include <net/route.h>
51 
52 #include <netinet/in.h>
53 #include <netinet/in_var.h>
54 
55 #include <netinet/ip6.h>
56 #include <netinet6/in6_ifattach.h>
57 #include <netinet6/ip6_var.h>
58 #include <netinet6/nd6.h>
59 #include <netinet6/ip6_mroute.h>
60 #include <netinet6/scope6_var.h>
61 
62 unsigned long in6_maxmtu = 0;
63 
64 int ip6_auto_linklocal = 1;	/* enable by default */
65 
66 callout_t in6_tmpaddrtimer_ch;
67 
68 
69 #if 0
70 static int get_hostid_ifid(struct ifnet *, struct in6_addr *);
71 #endif
72 static int get_rand_ifid(struct in6_addr *);
73 static int generate_tmp_ifid(u_int8_t *, const u_int8_t *, u_int8_t *);
74 static int get_ifid(struct ifnet *, struct ifnet *, struct in6_addr *);
75 static int in6_ifattach_linklocal(struct ifnet *, struct ifnet *);
76 static int in6_ifattach_loopback(struct ifnet *);
77 
78 #define EUI64_GBIT	0x01
79 #define EUI64_UBIT	0x02
80 #define EUI64_TO_IFID(in6)	do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (/*CONSTCOND*/ 0)
81 #define EUI64_GROUP(in6)	((in6)->s6_addr[8] & EUI64_GBIT)
82 #define EUI64_INDIVIDUAL(in6)	(!EUI64_GROUP(in6))
83 #define EUI64_LOCAL(in6)	((in6)->s6_addr[8] & EUI64_UBIT)
84 #define EUI64_UNIVERSAL(in6)	(!EUI64_LOCAL(in6))
85 
86 #define IFID_LOCAL(in6)		(!EUI64_LOCAL(in6))
87 #define IFID_UNIVERSAL(in6)	(!EUI64_UNIVERSAL(in6))
88 
89 #define GEN_TEMPID_RETRY_MAX 5
90 
91 #if 0
92 /*
93  * Generate a last-resort interface identifier from hostid.
94  * works only for certain architectures (like sparc).
95  * also, using hostid itself may constitute a privacy threat, much worse
96  * than MAC addresses (hostids are used for software licensing).
97  * maybe we should use MD5(hostid) instead.
98  *
99  * in6 - upper 64bits are preserved
100  */
101 static int
102 get_hostid_ifid(struct ifnet *ifp, struct in6_addr *in6)
103 {
104 	int off, len;
105 	static const uint8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
106 	static const uint8_t allone[8] =
107 	    { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
108 
109 	if (!hostid)
110 		return -1;
111 
112 	/* get up to 8 bytes from the hostid field - should we get */
113 	len = (sizeof(hostid) > 8) ? 8 : sizeof(hostid);
114 	off = sizeof(*in6) - len;
115 	memcpy(&in6->s6_addr[off], &hostid, len);
116 
117 	/* make sure we do not return anything bogus */
118 	if (memcmp(&in6->s6_addr[8], allzero, sizeof(allzero)))
119 		return -1;
120 	if (memcmp(&in6->s6_addr[8], allone, sizeof(allone)))
121 		return -1;
122 
123 	/* make sure to set "u" bit to local, and "g" bit to individual. */
124 	in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
125 	in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
126 
127 	/* convert EUI64 into IPv6 interface identifier */
128 	EUI64_TO_IFID(in6);
129 
130 	return 0;
131 }
132 #endif
133 
134 /*
135  * Generate a last-resort interface identifier, when the machine has no
136  * IEEE802/EUI64 address sources.
137  * The goal here is to get an interface identifier that is
138  * (1) random enough and (2) does not change across reboot.
139  * We currently use MD5(hostname) for it.
140  */
141 static int
142 get_rand_ifid(struct in6_addr *in6)	/* upper 64bits are preserved */
143 {
144 	MD5_CTX ctxt;
145 	u_int8_t digest[16];
146 
147 #if 0
148 	/* we need at least several letters as seed for ifid */
149 	if (hostnamelen < 3)
150 		return -1;
151 #endif
152 
153 	/* generate 8 bytes of pseudo-random value. */
154 	memset(&ctxt, 0, sizeof(ctxt));
155 	MD5Init(&ctxt);
156 	MD5Update(&ctxt, (u_char *)hostname, hostnamelen);
157 	MD5Final(digest, &ctxt);
158 
159 	/* assumes sizeof(digest) > sizeof(ifid) */
160 	memcpy(&in6->s6_addr[8], digest, 8);
161 
162 	/* make sure to set "u" bit to local, and "g" bit to individual. */
163 	in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
164 	in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
165 
166 	/* convert EUI64 into IPv6 interface identifier */
167 	EUI64_TO_IFID(in6);
168 
169 	return 0;
170 }
171 
172 static int
173 generate_tmp_ifid(u_int8_t *seed0, const u_int8_t *seed1, u_int8_t *ret)
174 {
175 	MD5_CTX ctxt;
176 	u_int8_t seed[16], digest[16], nullbuf[8];
177 	/*
178 	 * interface ID for subnet anycast addresses.
179 	 * XXX: we assume the unicast address range that requires IDs
180 	 * in EUI-64 format.
181 	 */
182 	static const uint8_t anycast_id[8] = { 0xfd, 0xff, 0xff, 0xff,
183 	    0xff, 0xff, 0xff, 0x80 };
184 	static const uint8_t isatap_id[4] = { 0x00, 0x00, 0x5e, 0xfe };
185 	int badid, retry = 0;
186 
187 	/* If there's no hisotry, start with a random seed. */
188 	memset(nullbuf, 0, sizeof(nullbuf));
189 	if (memcmp(nullbuf, seed0, sizeof(nullbuf)) == 0) {
190 		cprng_fast(seed, sizeof(seed));
191 	} else
192 		memcpy(seed, seed0, 8);
193 
194 	/* copy the right-most 64-bits of the given address */
195 	/* XXX assumption on the size of IFID */
196 	memcpy(&seed[8], seed1, 8);
197 
198   again:
199 	/* for debugging purposes only */
200 #if 0
201 	{
202 		int i;
203 
204 		printf("generate_tmp_ifid: new randomized ID from: ");
205 		for (i = 0; i < 16; i++)
206 			printf("%02x", seed[i]);
207 		printf(" ");
208 	}
209 #endif
210 
211 	/* generate 16 bytes of pseudo-random value. */
212 	memset(&ctxt, 0, sizeof(ctxt));
213 	MD5Init(&ctxt);
214 	MD5Update(&ctxt, seed, sizeof(seed));
215 	MD5Final(digest, &ctxt);
216 
217 	/*
218 	 * draft-ietf-ipngwg-temp-addresses-v2-00.txt 3.2.1. (3)
219 	 * Take the left-most 64-bits of the MD5 digest and set bit 6 (the
220 	 * left-most bit is numbered 0) to zero.
221 	 */
222 	memcpy(ret, digest, 8);
223 	ret[0] &= ~EUI64_UBIT;
224 
225 	/*
226 	 * Reject inappropriate identifiers according to
227 	 * draft-ietf-ipngwg-temp-addresses-v2-00.txt 3.2.1. (4)
228 	 * At this moment, we reject following cases:
229 	 * - all 0 identifier
230 	 * - identifiers that conflict with reserved subnet anycast addresses,
231 	 *   which are defined in RFC 2526.
232 	 * - identifiers that conflict with ISATAP addresses
233 	 * - identifiers used in our own addresses
234 	 */
235 	badid = 0;
236 	if (memcmp(nullbuf, ret, sizeof(nullbuf)) == 0)
237 		badid = 1;
238 	else if (memcmp(anycast_id, ret, 7) == 0 &&
239 	    (anycast_id[7] & ret[7]) == anycast_id[7]) {
240 		badid = 1;
241 	} else if (memcmp(isatap_id, ret, sizeof(isatap_id)) == 0)
242 		badid = 1;
243 	else {
244 		struct in6_ifaddr *ia;
245 		int s = pserialize_read_enter();
246 
247 		IN6_ADDRLIST_READER_FOREACH(ia) {
248 			if (!memcmp(&ia->ia_addr.sin6_addr.s6_addr[8],
249 			    ret, 8)) {
250 				badid = 1;
251 				break;
252 			}
253 		}
254 		pserialize_read_exit(s);
255 	}
256 
257 	/*
258 	 * In the event that an unacceptable identifier has been generated,
259 	 * restart the process, using the right-most 64 bits of the MD5 digest
260 	 * obtained in place of the history value.
261 	 */
262 	if (badid) {
263 		/* for debugging purposes only */
264 #if 0
265 		{
266 			int i;
267 
268 			printf("unacceptable random ID: ");
269 			for (i = 0; i < 16; i++)
270 				printf("%02x", digest[i]);
271 			printf("\n");
272 		}
273 #endif
274 
275 		if (++retry < GEN_TEMPID_RETRY_MAX) {
276 			memcpy(seed, &digest[8], 8);
277 			goto again;
278 		} else {
279 			/*
280 			 * We're so unlucky.  Give up for now, and return
281 			 * all 0 IDs to tell the caller not to make a
282 			 * temporary address.
283 			 */
284 			nd6log(LOG_NOTICE, "never found a good ID\n");
285 			memset(ret, 0, 8);
286 		}
287 	}
288 
289 	/*
290 	 * draft-ietf-ipngwg-temp-addresses-v2-00.txt 3.2.1. (6)
291 	 * Take the rightmost 64-bits of the MD5 digest and save them in
292 	 * stable storage as the history value to be used in the next
293 	 * iteration of the algorithm.
294 	 */
295 	memcpy(seed0, &digest[8], 8);
296 
297 	/* for debugging purposes only */
298 #if 0
299 	{
300 		int i;
301 
302 		printf("to: ");
303 		for (i = 0; i < 16; i++)
304 			printf("%02x", digest[i]);
305 		printf("\n");
306 	}
307 #endif
308 
309 	return 0;
310 }
311 
312 /*
313  * Get interface identifier for the specified interface.
314  *
315  * in6 - upper 64bits are preserved
316  */
317 int
318 in6_get_hw_ifid(struct ifnet *ifp, struct in6_addr *in6)
319 {
320 	struct ifaddr *ifa;
321 	const struct sockaddr_dl *sdl = NULL;
322 	const char *addr = NULL; /* XXX gcc 4.8 -Werror=maybe-uninitialized */
323 	size_t addrlen = 0; /* XXX gcc 4.8 -Werror=maybe-uninitialized */
324 	static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
325 	static u_int8_t allone[8] =
326 		{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
327 	int s;
328 
329 	s = pserialize_read_enter();
330 	IFADDR_READER_FOREACH(ifa, ifp) {
331 		const struct sockaddr_dl *tsdl;
332 		if (ifa->ifa_addr->sa_family != AF_LINK)
333 			continue;
334 		tsdl = satocsdl(ifa->ifa_addr);
335 		if (tsdl == NULL || tsdl->sdl_alen == 0)
336 			continue;
337 		if (sdl == NULL || ifa == ifp->if_dl || ifa == ifp->if_hwdl) {
338 			sdl = tsdl;
339 			addr = CLLADDR(sdl);
340 			addrlen = sdl->sdl_alen;
341 		}
342 		if (ifa == ifp->if_hwdl)
343 			break;
344 	}
345 	pserialize_read_exit(s);
346 
347 	if (sdl == NULL)
348 		return -1;
349 
350 	switch (ifp->if_type) {
351 	case IFT_IEEE1394:
352 	case IFT_IEEE80211:
353 		/* IEEE1394 uses 16byte length address starting with EUI64 */
354 		if (addrlen > 8)
355 			addrlen = 8;
356 		break;
357 	default:
358 		break;
359 	}
360 
361 	/* get EUI64 */
362 	switch (ifp->if_type) {
363 	/* IEEE802/EUI64 cases - what others? */
364 	case IFT_ETHER:
365 	case IFT_FDDI:
366 	case IFT_ATM:
367 	case IFT_IEEE1394:
368 	case IFT_IEEE80211:
369 		/* look at IEEE802/EUI64 only */
370 		if (addrlen != 8 && addrlen != 6)
371 			return -1;
372 
373 		/*
374 		 * check for invalid MAC address - on bsdi, we see it a lot
375 		 * since wildboar configures all-zero MAC on pccard before
376 		 * card insertion.
377 		 */
378 		if (memcmp(addr, allzero, addrlen) == 0)
379 			return -1;
380 		if (memcmp(addr, allone, addrlen) == 0)
381 			return -1;
382 
383 		/* make EUI64 address */
384 		if (addrlen == 8)
385 			memcpy(&in6->s6_addr[8], addr, 8);
386 		else if (addrlen == 6) {
387 			in6->s6_addr[8] = addr[0];
388 			in6->s6_addr[9] = addr[1];
389 			in6->s6_addr[10] = addr[2];
390 			in6->s6_addr[11] = 0xff;
391 			in6->s6_addr[12] = 0xfe;
392 			in6->s6_addr[13] = addr[3];
393 			in6->s6_addr[14] = addr[4];
394 			in6->s6_addr[15] = addr[5];
395 		}
396 		break;
397 
398 	case IFT_ARCNET:
399 		if (addrlen != 1)
400 			return -1;
401 		if (!addr[0])
402 			return -1;
403 
404 		memset(&in6->s6_addr[8], 0, 8);
405 		in6->s6_addr[15] = addr[0];
406 
407 		/*
408 		 * due to insufficient bitwidth, we mark it local.
409 		 */
410 		in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
411 		in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
412 		break;
413 
414 	case IFT_GIF:
415 #ifdef IFT_STF
416 	case IFT_STF:
417 #endif
418 		/*
419 		 * RFC2893 says: "SHOULD use IPv4 address as ifid source".
420 		 * however, IPv4 address is not very suitable as unique
421 		 * identifier source (can be renumbered).
422 		 * we don't do this.
423 		 */
424 		return -1;
425 
426 	default:
427 		return -1;
428 	}
429 
430 	/* sanity check: g bit must not indicate "group" */
431 	if (EUI64_GROUP(in6))
432 		return -1;
433 
434 	/* convert EUI64 into IPv6 interface identifier */
435 	EUI64_TO_IFID(in6);
436 
437 	/*
438 	 * sanity check: ifid must not be all zero, avoid conflict with
439 	 * subnet router anycast
440 	 */
441 	if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
442 	    memcmp(&in6->s6_addr[9], allzero, 7) == 0) {
443 		return -1;
444 	}
445 
446 	return 0;
447 }
448 
449 /*
450  * Get interface identifier for the specified interface.  If it is not
451  * available on ifp0, borrow interface identifier from other information
452  * sources.
453  *
454  * altifp - secondary EUI64 source
455  */
456 static int
457 get_ifid(struct ifnet *ifp0, struct ifnet *altifp,
458 	struct in6_addr *in6)
459 {
460 	struct ifnet *ifp;
461 	int s;
462 
463 	/* first, try to get it from the interface itself */
464 	if (in6_get_hw_ifid(ifp0, in6) == 0) {
465 		nd6log(LOG_DEBUG, "%s: got interface identifier from itself\n",
466 		    if_name(ifp0));
467 		goto success;
468 	}
469 
470 	/* try secondary EUI64 source. this basically is for ATM PVC */
471 	if (altifp && in6_get_hw_ifid(altifp, in6) == 0) {
472 		nd6log(LOG_DEBUG, "%s: got interface identifier from %s\n",
473 		    if_name(ifp0), if_name(altifp));
474 		goto success;
475 	}
476 
477 	/* next, try to get it from some other hardware interface */
478 	s = pserialize_read_enter();
479 	IFNET_READER_FOREACH(ifp) {
480 		if (ifp == ifp0)
481 			continue;
482 		if (in6_get_hw_ifid(ifp, in6) != 0)
483 			continue;
484 
485 		/*
486 		 * to borrow ifid from other interface, ifid needs to be
487 		 * globally unique
488 		 */
489 		if (IFID_UNIVERSAL(in6)) {
490 			nd6log(LOG_DEBUG,
491 			    "%s: borrow interface identifier from %s\n",
492 			    if_name(ifp0), if_name(ifp));
493 			pserialize_read_exit(s);
494 			goto success;
495 		}
496 	}
497 	pserialize_read_exit(s);
498 
499 #if 0
500 	/* get from hostid - only for certain architectures */
501 	if (get_hostid_ifid(ifp, in6) == 0) {
502 		nd6log(LOG_DEBUG,
503 		    "%s: interface identifier generated by hostid\n",
504 		    if_name(ifp0));
505 		goto success;
506 	}
507 #endif
508 
509 	/* last resort: get from random number source */
510 	if (get_rand_ifid(in6) == 0) {
511 		nd6log(LOG_DEBUG,
512 		    "%s: interface identifier generated by random number\n",
513 		    if_name(ifp0));
514 		goto success;
515 	}
516 
517 	printf("%s: failed to get interface identifier\n", if_name(ifp0));
518 	return -1;
519 
520 success:
521 	nd6log(LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
522 	    if_name(ifp0), in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10],
523 	    in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13],
524 	    in6->s6_addr[14], in6->s6_addr[15]);
525 	return 0;
526 }
527 
528 /*
529  * altifp - secondary EUI64 source
530  */
531 
532 static int
533 in6_ifattach_linklocal(struct ifnet *ifp, struct ifnet *altifp)
534 {
535 	struct in6_aliasreq ifra;
536 	int error;
537 
538 	/*
539 	 * configure link-local address.
540 	 */
541 	memset(&ifra, 0, sizeof(ifra));
542 
543 	/*
544 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
545 	 * for safety.
546 	 */
547 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
548 
549 	ifra.ifra_addr.sin6_family = AF_INET6;
550 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
551 	ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000);
552 	ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
553 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
554 		ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
555 		ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
556 	} else {
557 		if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) {
558 			nd6log(LOG_ERR,
559 			    "%s: no ifid available\n", if_name(ifp));
560 			return -1;
561 		}
562 	}
563 	if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL))
564 		return -1;
565 
566 	sockaddr_in6_init(&ifra.ifra_prefixmask, &in6mask64, 0, 0, 0);
567 	/* link-local addresses should NEVER expire. */
568 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
569 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
570 
571 	/*
572 	 * Now call in6_update_ifa() to do a bunch of procedures to configure
573 	 * a link-local address. We can set the 3rd argument to NULL, because
574 	 * we know there's no other link-local address on the interface
575 	 * and therefore we are adding one (instead of updating one).
576 	 */
577 	if ((error = in6_update_ifa(ifp, &ifra, IN6_IFAUPDATE_DADDELAY)) != 0) {
578 		/*
579 		 * XXX: When the interface does not support IPv6, this call
580 		 * would fail in the SIOCINITIFADDR ioctl.  I believe the
581 		 * notification is rather confusing in this case, so just
582 		 * suppress it.  (jinmei@kame.net 20010130)
583 		 */
584 		if (error != EAFNOSUPPORT)
585 			nd6log(LOG_NOTICE,
586 			    "failed to configure a link-local address on %s "
587 			    "(errno=%d)\n",
588 			    if_name(ifp), error);
589 		return -1;
590 	}
591 
592 	return 0;
593 }
594 
595 /*
596  * ifp - mut be IFT_LOOP
597  */
598 
599 static int
600 in6_ifattach_loopback(struct ifnet *ifp)
601 {
602 	struct in6_aliasreq ifra;
603 	int error;
604 
605 	memset(&ifra, 0, sizeof(ifra));
606 
607 	/*
608 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
609 	 * for safety.
610 	 */
611 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
612 
613 	sockaddr_in6_init(&ifra.ifra_prefixmask, &in6mask128, 0, 0, 0);
614 
615 	/*
616 	 * Always initialize ia_dstaddr (= broadcast address) to loopback
617 	 * address.  Follows IPv4 practice - see in_ifinit().
618 	 */
619 	sockaddr_in6_init(&ifra.ifra_dstaddr, &in6addr_loopback, 0, 0, 0);
620 
621 	sockaddr_in6_init(&ifra.ifra_addr, &in6addr_loopback, 0, 0, 0);
622 
623 	/* the loopback  address should NEVER expire. */
624 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
625 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
626 
627 	/* we don't need to perform DAD on loopback interfaces. */
628 	ifra.ifra_flags |= IN6_IFF_NODAD;
629 
630 	/*
631 	 * We are sure that this is a newly assigned address, so we can set
632 	 * NULL to the 3rd arg.
633 	 */
634 	if ((error = in6_update_ifa(ifp, &ifra, 0)) != 0) {
635 		nd6log(LOG_ERR, "failed to configure "
636 		    "the loopback address on %s (errno=%d)\n",
637 		    if_name(ifp), error);
638 		return -1;
639 	}
640 
641 	return 0;
642 }
643 
644 /*
645  * compute NI group address, based on the current hostname setting.
646  * see draft-ietf-ipngwg-icmp-name-lookup-* (04 and later).
647  *
648  * when ifp == NULL, the caller is responsible for filling scopeid.
649  */
650 int
651 in6_nigroup(struct ifnet *ifp, const char *name, int namelen,
652 	struct sockaddr_in6 *sa6)
653 {
654 	const char *p;
655 	u_int8_t *q;
656 	MD5_CTX ctxt;
657 	u_int8_t digest[16];
658 	u_int8_t l;
659 	u_int8_t n[64];	/* a single label must not exceed 63 chars */
660 
661 	if (!namelen || !name)
662 		return -1;
663 
664 	p = name;
665 	while (p && *p && *p != '.' && p - name < namelen)
666 		p++;
667 	if (p - name > sizeof(n) - 1)
668 		return -1;	/* label too long */
669 	l = p - name;
670 	strncpy((char *)n, name, l);
671 	n[(int)l] = '\0';
672 	for (q = n; *q; q++) {
673 		if ('A' <= *q && *q <= 'Z')
674 			*q = *q - 'A' + 'a';
675 	}
676 
677 	/* generate 8 bytes of pseudo-random value. */
678 	memset(&ctxt, 0, sizeof(ctxt));
679 	MD5Init(&ctxt);
680 	MD5Update(&ctxt, &l, sizeof(l));
681 	MD5Update(&ctxt, n, l);
682 	MD5Final(digest, &ctxt);
683 
684 	memset(sa6, 0, sizeof(*sa6));
685 	sa6->sin6_family = AF_INET6;
686 	sa6->sin6_len = sizeof(*sa6);
687 	sa6->sin6_addr.s6_addr16[0] = htons(0xff02);
688 	sa6->sin6_addr.s6_addr8[11] = 2;
689 	memcpy(&sa6->sin6_addr.s6_addr32[3], digest,
690 	    sizeof(sa6->sin6_addr.s6_addr32[3]));
691 	if (in6_setscope(&sa6->sin6_addr, ifp, NULL))
692 		return -1; /* XXX: should not fail */
693 
694 	return 0;
695 }
696 
697 /*
698  * XXX multiple loopback interface needs more care.  for instance,
699  * nodelocal address needs to be configured onto only one of them.
700  * XXX multiple link-local address case
701  *
702  * altifp - secondary EUI64 source
703  */
704 void
705 in6_ifattach(struct ifnet *ifp, struct ifnet *altifp)
706 {
707 	struct in6_ifaddr *ia;
708 	struct in6_addr in6;
709 
710 	KASSERT(IFNET_LOCKED(ifp));
711 
712 	/* some of the interfaces are inherently not IPv6 capable */
713 	switch (ifp->if_type) {
714 	case IFT_BRIDGE:
715 	case IFT_L2TP:
716 #ifdef IFT_PFLOG
717 	case IFT_PFLOG:
718 #endif
719 #ifdef IFT_PFSYNC
720 	case IFT_PFSYNC:
721 #endif
722 		ND_IFINFO(ifp)->flags &= ~ND6_IFF_AUTO_LINKLOCAL;
723 		ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
724 		return;
725 	}
726 
727 	/*
728 	 * if link mtu is too small, don't try to configure IPv6.
729 	 * remember there could be some link-layer that has special
730 	 * fragmentation logic.
731 	 */
732 	if (ifp->if_mtu < IPV6_MMTU) {
733 		nd6log(LOG_INFO, "%s has too small MTU, IPv6 not enabled\n",
734 		    if_name(ifp));
735 		return;
736 	}
737 
738 	/*
739 	 * quirks based on interface type
740 	 */
741 	switch (ifp->if_type) {
742 #ifdef IFT_STF
743 	case IFT_STF:
744 		/*
745 		 * 6to4 interface is a very special kind of beast.
746 		 * no multicast, no linklocal.  RFC2529 specifies how to make
747 		 * linklocals for 6to4 interface, but there's no use and
748 		 * it is rather harmful to have one.
749 		 */
750 		ND_IFINFO(ifp)->flags &= ~ND6_IFF_AUTO_LINKLOCAL;
751 		return;
752 #endif
753 	case IFT_CARP:
754 		return;
755 	default:
756 		break;
757 	}
758 
759 	/*
760 	 * usually, we require multicast capability to the interface
761 	 */
762 	if ((ifp->if_flags & IFF_MULTICAST) == 0) {
763 		nd6log(LOG_INFO,
764 		    "%s is not multicast capable, IPv6 not enabled\n",
765 		    if_name(ifp));
766 		return;
767 	}
768 
769 	/*
770 	 * assign loopback address for loopback interface.
771 	 * XXX multiple loopback interface case.
772 	 */
773 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
774 		in6 = in6addr_loopback;
775 		/* These are safe and atomic thanks to IFNET_LOCK */
776 		if (in6ifa_ifpwithaddr(ifp, &in6) == NULL) {
777 			if (in6_ifattach_loopback(ifp) != 0)
778 				return;
779 		}
780 	}
781 
782 	/*
783 	 * assign a link-local address, if there's none.
784 	 */
785 	if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
786 	    ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL) {
787 		int bound = curlwp_bind();
788 		struct psref psref;
789 		ia = in6ifa_ifpforlinklocal_psref(ifp, 0, &psref);
790 		if (ia == NULL && in6_ifattach_linklocal(ifp, altifp) != 0) {
791 			printf("%s: cannot assign link-local address\n",
792 			    ifp->if_xname);
793 		}
794 		ia6_release(ia, &psref);
795 		curlwp_bindx(bound);
796 	}
797 }
798 
799 /*
800  * NOTE: in6_ifdetach() does not support loopback if at this moment.
801  * We don't need this function in bsdi, because interfaces are never removed
802  * from the ifnet list in bsdi.
803  */
804 void
805 in6_ifdetach(struct ifnet *ifp)
806 {
807 
808 	/* nuke any of IPv6 addresses we have */
809 	if_purgeaddrs(ifp, AF_INET6, in6_purgeaddr);
810 
811 	in6_purge_multi(ifp);
812 
813 	/* remove ip6_mrouter stuff */
814 	ip6_mrouter_detach(ifp);
815 
816 	/* remove neighbor management table */
817 	nd6_purge(ifp, NULL);
818 
819 	nd6_assert_purged(ifp);
820 }
821 
822 int
823 in6_get_tmpifid(struct ifnet *ifp, u_int8_t *retbuf,
824 	const u_int8_t *baseid, int generate)
825 {
826 	u_int8_t nullbuf[8];
827 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
828 
829 	memset(nullbuf, 0, sizeof(nullbuf));
830 	if (memcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
831 		/* we've never created a random ID.  Create a new one. */
832 		generate = 1;
833 	}
834 
835 	if (generate) {
836 		memcpy(ndi->randomseed1, baseid, sizeof(ndi->randomseed1));
837 
838 		/* generate_tmp_ifid will update seedn and buf */
839 		(void)generate_tmp_ifid(ndi->randomseed0, ndi->randomseed1,
840 		    ndi->randomid);
841 	}
842 	memcpy(retbuf, ndi->randomid, 8);
843 	if (generate && memcmp(retbuf, nullbuf, sizeof(nullbuf)) == 0) {
844 		/* generate_tmp_ifid could not found a good ID. */
845 		return -1;
846 	}
847 
848 	return 0;
849 }
850 
851 void
852 in6_tmpaddrtimer(void *ignored_arg)
853 {
854 	struct nd_ifinfo *ndi;
855 	u_int8_t nullbuf[8];
856 	struct ifnet *ifp;
857 	int s;
858 
859 	/* XXX NOMPSAFE still need softnet_lock */
860 	mutex_enter(softnet_lock);
861 	KERNEL_LOCK(1, NULL);
862 
863 	callout_reset(&in6_tmpaddrtimer_ch,
864 	    (ip6_temp_preferred_lifetime - ip6_desync_factor -
865 	    ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, NULL);
866 
867 	memset(nullbuf, 0, sizeof(nullbuf));
868 	s = pserialize_read_enter();
869 	IFNET_READER_FOREACH(ifp) {
870 		ndi = ND_IFINFO(ifp);
871 		if (memcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
872 			/*
873 			 * We've been generating a random ID on this interface.
874 			 * Create a new one.
875 			 */
876 			(void)generate_tmp_ifid(ndi->randomseed0,
877 			    ndi->randomseed1, ndi->randomid);
878 		}
879 	}
880 	pserialize_read_exit(s);
881 
882 	KERNEL_UNLOCK_ONE(NULL);
883 	mutex_exit(softnet_lock);
884 }
885