xref: /netbsd-src/sys/netinet6/in6_ifattach.c (revision fad4c9f71477ae11cea2ee75ec82151ac770a534)
1 /*	$NetBSD: in6_ifattach.c,v 1.65 2006/05/18 09:05:51 liamjfoy 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 1.65 2006/05/18 09:05:51 liamjfoy Exp $");
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/malloc.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 
45 #include <net/if.h>
46 #include <net/if_dl.h>
47 #include <net/if_types.h>
48 #include <net/route.h>
49 
50 #include <netinet/in.h>
51 #include <netinet/in_var.h>
52 
53 #include <netinet/ip6.h>
54 #include <netinet6/in6_ifattach.h>
55 #include <netinet6/ip6_var.h>
56 #include <netinet6/nd6.h>
57 #include <netinet6/ip6_mroute.h>
58 #include <netinet6/scope6_var.h>
59 
60 #include <net/net_osdep.h>
61 
62 unsigned long in6_maxmtu = 0;
63 
64 int ip6_auto_linklocal = 1;	/* enable by default */
65 
66 struct callout in6_tmpaddrtimer_ch = CALLOUT_INITIALIZER;
67 
68 
69 #if 0
70 static int get_hostid_ifid __P((struct ifnet *, struct in6_addr *));
71 #endif
72 static int get_rand_ifid __P((struct ifnet *, struct in6_addr *));
73 static int generate_tmp_ifid __P((u_int8_t *, const u_int8_t *, u_int8_t *));
74 static int get_ifid __P((struct ifnet *, struct ifnet *, struct in6_addr *));
75 static int in6_ifattach_linklocal __P((struct ifnet *, struct ifnet *));
76 static int in6_ifattach_loopback __P((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 static int
100 get_hostid_ifid(ifp, in6)
101 	struct ifnet *ifp;
102 	struct in6_addr *in6;	/* upper 64bits are preserved */
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(ifp, in6)
143 	struct ifnet *ifp;
144 	struct in6_addr *in6;	/* upper 64bits are preserved */
145 {
146 	MD5_CTX ctxt;
147 	u_int8_t digest[16];
148 
149 #if 0
150 	/* we need at least several letters as seed for ifid */
151 	if (hostnamelen < 3)
152 		return -1;
153 #endif
154 
155 	/* generate 8 bytes of pseudo-random value. */
156 	memset(&ctxt, 0, sizeof(ctxt));
157 	MD5Init(&ctxt);
158 	MD5Update(&ctxt, (u_char *)hostname, hostnamelen);
159 	MD5Final(digest, &ctxt);
160 
161 	/* assumes sizeof(digest) > sizeof(ifid) */
162 	memcpy(&in6->s6_addr[8], digest, 8);
163 
164 	/* make sure to set "u" bit to local, and "g" bit to individual. */
165 	in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
166 	in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
167 
168 	/* convert EUI64 into IPv6 interface identifier */
169 	EUI64_TO_IFID(in6);
170 
171 	return 0;
172 }
173 
174 static int
175 generate_tmp_ifid(seed0, seed1, ret)
176 	u_int8_t *seed0, *ret;
177 	const u_int8_t *seed1;
178 {
179 	MD5_CTX ctxt;
180 	u_int8_t seed[16], digest[16], nullbuf[8];
181 	u_int32_t val32;
182 	/*
183 	 * interface ID for subnet anycast addresses.
184 	 * XXX: we assume the unicast address range that requires IDs
185 	 * in EUI-64 format.
186 	 */
187 	static const uint8_t anycast_id[8] = { 0xfd, 0xff, 0xff, 0xff,
188 	    0xff, 0xff, 0xff, 0x80 };
189 	static const uint8_t isatap_id[4] = { 0x00, 0x00, 0x5e, 0xfe };
190 	int badid, retry = 0;
191 
192 	/* If there's no hisotry, start with a random seed. */
193 	memset(nullbuf, 0, sizeof(nullbuf));
194 	if (memcmp(nullbuf, seed0, sizeof(nullbuf)) == 0) {
195 		int i;
196 
197 		for (i = 0; i < 2; i++) {
198 			val32 = arc4random();
199 			memcpy(seed + sizeof(val32) * i, &val32, sizeof(val32));
200 		}
201 	} else
202 		memcpy(seed, seed0, 8);
203 
204 	/* copy the right-most 64-bits of the given address */
205 	/* XXX assumption on the size of IFID */
206 	memcpy(&seed[8], seed1, 8);
207 
208   again:
209 	/* for debugging purposes only */
210 #if 0
211 	{
212 		int i;
213 
214 		printf("generate_tmp_ifid: new randomized ID from: ");
215 		for (i = 0; i < 16; i++)
216 			printf("%02x", seed[i]);
217 		printf(" ");
218 	}
219 #endif
220 
221 	/* generate 16 bytes of pseudo-random value. */
222 	memset(&ctxt, 0, sizeof(ctxt));
223 	MD5Init(&ctxt);
224 	MD5Update(&ctxt, seed, sizeof(seed));
225 	MD5Final(digest, &ctxt);
226 
227 	/*
228 	 * draft-ietf-ipngwg-temp-addresses-v2-00.txt 3.2.1. (3)
229 	 * Take the left-most 64-bits of the MD5 digest and set bit 6 (the
230 	 * left-most bit is numbered 0) to zero.
231 	 */
232 	memcpy(ret, digest, 8);
233 	ret[0] &= ~EUI64_UBIT;
234 
235 	/*
236 	 * Reject inappropriate identifiers according to
237 	 * draft-ietf-ipngwg-temp-addresses-v2-00.txt 3.2.1. (4)
238 	 * At this moment, we reject following cases:
239 	 * - all 0 identifier
240 	 * - identifiers that conflict with reserved subnet anycast addresses,
241 	 *   which are defined in RFC 2526.
242 	 * - identifiers that conflict with ISATAP addresses
243 	 * - identifiers used in our own addresses
244 	 */
245 	badid = 0;
246 	if (memcmp(nullbuf, ret, sizeof(nullbuf)) == 0)
247 		badid = 1;
248 	else if (memcmp(anycast_id, ret, 7) == 0 &&
249 	    (anycast_id[7] & ret[7]) == anycast_id[7]) {
250 		badid = 1;
251 	} else if (memcmp(isatap_id, ret, sizeof(isatap_id)) == 0)
252 		badid = 1;
253 	else {
254 		struct in6_ifaddr *ia;
255 
256 		for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
257 			if (!memcmp(&ia->ia_addr.sin6_addr.s6_addr[8],
258 			    ret, 8)) {
259 				badid = 1;
260 				break;
261 			}
262 		}
263 	}
264 
265 	/*
266 	 * In the event that an unacceptable identifier has been generated,
267 	 * restart the process, using the right-most 64 bits of the MD5 digest
268 	 * obtained in place of the history value.
269 	 */
270 	if (badid) {
271 		/* for debugging purposes only */
272 #if 0
273 		{
274 			int i;
275 
276 			printf("unacceptable random ID: ");
277 			for (i = 0; i < 16; i++)
278 				printf("%02x", digest[i]);
279 			printf("\n");
280 		}
281 #endif
282 
283 		if (++retry < GEN_TEMPID_RETRY_MAX) {
284 			memcpy(seed, &digest[8], 8);
285 			goto again;
286 		} else {
287 			/*
288 			 * We're so unlucky.  Give up for now, and return
289 			 * all 0 IDs to tell the caller not to make a
290 			 * temporary address.
291 			 */
292 			nd6log((LOG_NOTICE,
293 			    "generate_tmp_ifid: never found a good ID\n"));
294 			memset(ret, 0, 8);
295 		}
296 	}
297 
298 	/*
299 	 * draft-ietf-ipngwg-temp-addresses-v2-00.txt 3.2.1. (6)
300 	 * Take the rightmost 64-bits of the MD5 digest and save them in
301 	 * stable storage as the history value to be used in the next
302 	 * iteration of the algorithm.
303 	 */
304 	memcpy(seed0, &digest[8], 8);
305 
306 	/* for debugging purposes only */
307 #if 0
308 	{
309 		int i;
310 
311 		printf("to: ");
312 		for (i = 0; i < 16; i++)
313 			printf("%02x", digest[i]);
314 		printf("\n");
315 	}
316 #endif
317 
318 	return 0;
319 }
320 /*
321  * Get interface identifier for the specified interface.
322  * XXX assumes single sockaddr_dl (AF_LINK address) per an interface
323  */
324 int
325 in6_get_hw_ifid(ifp, in6)
326 	struct ifnet *ifp;
327 	struct in6_addr *in6;	/* upper 64bits are preserved */
328 {
329 	struct ifaddr *ifa;
330 	struct sockaddr_dl *sdl;
331 	char *addr;
332 	size_t addrlen;
333 	static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
334 	static u_int8_t allone[8] =
335 		{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
336 
337 	for (ifa = ifp->if_addrlist.tqh_first;
338 	     ifa;
339 	     ifa = ifa->ifa_list.tqe_next)
340 	{
341 		if (ifa->ifa_addr->sa_family != AF_LINK)
342 			continue;
343 		sdl = (struct sockaddr_dl *)ifa->ifa_addr;
344 		if (sdl == NULL)
345 			continue;
346 		if (sdl->sdl_alen == 0)
347 			continue;
348 
349 		goto found;
350 	}
351 
352 	return -1;
353 
354 found:
355 	addr = LLADDR(sdl);
356 	addrlen = sdl->sdl_alen;
357 
358 	switch (ifp->if_type) {
359 	case IFT_IEEE1394:
360 	case IFT_IEEE80211:
361 		/* IEEE1394 uses 16byte length address starting with EUI64 */
362 		if (addrlen > 8)
363 			addrlen = 8;
364 		break;
365 	default:
366 		break;
367 	}
368 
369 	/* get EUI64 */
370 	switch (ifp->if_type) {
371 	/* IEEE802/EUI64 cases - what others? */
372 	case IFT_ETHER:
373 	case IFT_FDDI:
374 	case IFT_ATM:
375 	case IFT_IEEE1394:
376 	case IFT_IEEE80211:
377 		/* look at IEEE802/EUI64 only */
378 		if (addrlen != 8 && addrlen != 6)
379 			return -1;
380 
381 		/*
382 		 * check for invalid MAC address - on bsdi, we see it a lot
383 		 * since wildboar configures all-zero MAC on pccard before
384 		 * card insertion.
385 		 */
386 		if (memcmp(addr, allzero, addrlen) == 0)
387 			return -1;
388 		if (memcmp(addr, allone, addrlen) == 0)
389 			return -1;
390 
391 		/* make EUI64 address */
392 		if (addrlen == 8)
393 			memcpy(&in6->s6_addr[8], addr, 8);
394 		else if (addrlen == 6) {
395 			in6->s6_addr[8] = addr[0];
396 			in6->s6_addr[9] = addr[1];
397 			in6->s6_addr[10] = addr[2];
398 			in6->s6_addr[11] = 0xff;
399 			in6->s6_addr[12] = 0xfe;
400 			in6->s6_addr[13] = addr[3];
401 			in6->s6_addr[14] = addr[4];
402 			in6->s6_addr[15] = addr[5];
403 		}
404 		break;
405 
406 	case IFT_ARCNET:
407 		if (addrlen != 1)
408 			return -1;
409 		if (!addr[0])
410 			return -1;
411 
412 		memset(&in6->s6_addr[8], 0, 8);
413 		in6->s6_addr[15] = addr[0];
414 
415 		/*
416 		 * due to insufficient bitwidth, we mark it local.
417 		 */
418 		in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
419 		in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
420 		break;
421 
422 	case IFT_GIF:
423 #ifdef IFT_STF
424 	case IFT_STF:
425 #endif
426 		/*
427 		 * RFC2893 says: "SHOULD use IPv4 address as ifid source".
428 		 * however, IPv4 address is not very suitable as unique
429 		 * identifier source (can be renumbered).
430 		 * we don't do this.
431 		 */
432 		return -1;
433 
434 	default:
435 		return -1;
436 	}
437 
438 	/* sanity check: g bit must not indicate "group" */
439 	if (EUI64_GROUP(in6))
440 		return -1;
441 
442 	/* convert EUI64 into IPv6 interface identifier */
443 	EUI64_TO_IFID(in6);
444 
445 	/*
446 	 * sanity check: ifid must not be all zero, avoid conflict with
447 	 * subnet router anycast
448 	 */
449 	if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
450 	    memcmp(&in6->s6_addr[9], allzero, 7) == 0) {
451 		return -1;
452 	}
453 
454 	return 0;
455 }
456 
457 /*
458  * Get interface identifier for the specified interface.  If it is not
459  * available on ifp0, borrow interface identifier from other information
460  * sources.
461  */
462 static int
463 get_ifid(ifp0, altifp, in6)
464 	struct ifnet *ifp0;
465 	struct ifnet *altifp;	/*secondary EUI64 source*/
466 	struct in6_addr *in6;
467 {
468 	struct ifnet *ifp;
469 
470 	/* first, try to get it from the interface itself */
471 	if (in6_get_hw_ifid(ifp0, in6) == 0) {
472 		nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n",
473 		    if_name(ifp0)));
474 		goto success;
475 	}
476 
477 	/* try secondary EUI64 source. this basically is for ATM PVC */
478 	if (altifp && in6_get_hw_ifid(altifp, in6) == 0) {
479 		nd6log((LOG_DEBUG, "%s: got interface identifier from %s\n",
480 		    if_name(ifp0), if_name(altifp)));
481 		goto success;
482 	}
483 
484 	/* next, try to get it from some other hardware interface */
485 	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_list.tqe_next)
486 	{
487 		if (ifp == ifp0)
488 			continue;
489 		if (in6_get_hw_ifid(ifp, in6) != 0)
490 			continue;
491 
492 		/*
493 		 * to borrow ifid from other interface, ifid needs to be
494 		 * globally unique
495 		 */
496 		if (IFID_UNIVERSAL(in6)) {
497 			nd6log((LOG_DEBUG,
498 			    "%s: borrow interface identifier from %s\n",
499 			    if_name(ifp0), if_name(ifp)));
500 			goto success;
501 		}
502 	}
503 
504 #if 0
505 	/* get from hostid - only for certain architectures */
506 	if (get_hostid_ifid(ifp, in6) == 0) {
507 		nd6log((LOG_DEBUG,
508 		    "%s: interface identifier generated by hostid\n",
509 		    if_name(ifp0)));
510 		goto success;
511 	}
512 #endif
513 
514 	/* last resort: get from random number source */
515 	if (get_rand_ifid(ifp, in6) == 0) {
516 		nd6log((LOG_DEBUG,
517 		    "%s: interface identifier generated by random number\n",
518 		    if_name(ifp0)));
519 		goto success;
520 	}
521 
522 	printf("%s: failed to get interface identifier\n", if_name(ifp0));
523 	return -1;
524 
525 success:
526 	nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
527 	    if_name(ifp0), in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10],
528 	    in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13],
529 	    in6->s6_addr[14], in6->s6_addr[15]));
530 	return 0;
531 }
532 
533 static int
534 in6_ifattach_linklocal(ifp, altifp)
535 	struct ifnet *ifp;
536 	struct ifnet *altifp;	/*secondary EUI64 source*/
537 {
538 	struct in6_ifaddr *ia;
539 	struct in6_aliasreq ifra;
540 	struct nd_prefixctl pr0;
541 	int i, error;
542 
543 	/*
544 	 * configure link-local address.
545 	 */
546 	memset(&ifra, 0, 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_addr.sin6_family = AF_INET6;
555 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
556 	ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000);
557 	ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
558 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
559 		ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
560 		ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
561 	} else {
562 		if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) {
563 			nd6log((LOG_ERR,
564 			    "%s: no ifid available\n", if_name(ifp)));
565 			return (-1);
566 		}
567 	}
568 	if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL))
569 		return (-1);
570 
571 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
572 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
573 	ifra.ifra_prefixmask.sin6_addr = in6mask64;
574 	/* link-local addresses should NEVER expire. */
575 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
576 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
577 
578 	/*
579 	 * Now call in6_update_ifa() to do a bunch of procedures to configure
580 	 * a link-local address. We can set NULL to the 3rd argument, because
581 	 * we know there's no other link-local address on the interface
582 	 * and therefore we are adding one (instead of updating one).
583 	 */
584 	if ((error = in6_update_ifa(ifp, &ifra, NULL,
585 	    IN6_IFAUPDATE_DADDELAY)) != 0) {
586 		/*
587 		 * XXX: When the interface does not support IPv6, this call
588 		 * would fail in the SIOCSIFADDR ioctl.  I believe the
589 		 * notification is rather confusing in this case, so just
590 		 * suppress it.  (jinmei@kame.net 20010130)
591 		 */
592 		if (error != EAFNOSUPPORT)
593 			nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to "
594 			    "configure a link-local address on %s "
595 			    "(errno=%d)\n",
596 			    if_name(ifp), error));
597 		return (-1);
598 	}
599 
600 	ia = in6ifa_ifpforlinklocal(ifp, 0); /* ia must not be NULL */
601 #ifdef DIAGNOSTIC
602 	if (!ia) {
603 		panic("ia == NULL in in6_ifattach_linklocal");
604 		/* NOTREACHED */
605 	}
606 #endif
607 
608 	/*
609 	 * Make the link-local prefix (fe80::/64%link) as on-link.
610 	 * Since we'd like to manage prefixes separately from addresses,
611 	 * we make an ND6 prefix structure for the link-local prefix,
612 	 * and add it to the prefix list as a never-expire prefix.
613 	 * XXX: this change might affect some existing code base...
614 	 */
615 	memset(&pr0, 0, sizeof(pr0));
616 	pr0.ndpr_ifp = ifp;
617 	/* this should be 64 at this moment. */
618 	pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
619 	pr0.ndpr_prefix = ifra.ifra_addr;
620 	/* apply the mask for safety. (nd6_prelist_add will apply it again) */
621 	for (i = 0; i < 4; i++) {
622 		pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
623 		    in6mask64.s6_addr32[i];
624 	}
625 	/*
626 	 * Initialize parameters.  The link-local prefix must always be
627 	 * on-link, and its lifetimes never expire.
628 	 */
629 	pr0.ndpr_raf_onlink = 1;
630 	pr0.ndpr_raf_auto = 1;	/* probably meaningless */
631 	pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
632 	pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
633 	/*
634 	 * Since there is no other link-local addresses, nd6_prefix_lookup()
635 	 * probably returns NULL.  However, we cannot always expect the result.
636 	 * For example, if we first remove the (only) existing link-local
637 	 * address, and then reconfigure another one, the prefix is still
638 	 * valid with referring to the old link-local address.
639 	 */
640 	if (nd6_prefix_lookup(&pr0) == NULL) {
641 		if ((error = nd6_prelist_add(&pr0, NULL, NULL)) != 0)
642 			return (error);
643 	}
644 
645 	return 0;
646 }
647 
648 static int
649 in6_ifattach_loopback(ifp)
650 	struct ifnet *ifp;	/* must be IFT_LOOP */
651 {
652 	struct in6_aliasreq ifra;
653 	int error;
654 
655 	memset(&ifra, 0, sizeof(ifra));
656 
657 	/*
658 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
659 	 * for safety.
660 	 */
661 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
662 
663 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
664 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
665 	ifra.ifra_prefixmask.sin6_addr = in6mask128;
666 
667 	/*
668 	 * Always initialize ia_dstaddr (= broadcast address) to loopback
669 	 * address.  Follows IPv4 practice - see in_ifinit().
670 	 */
671 	ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
672 	ifra.ifra_dstaddr.sin6_family = AF_INET6;
673 	ifra.ifra_dstaddr.sin6_addr = in6addr_loopback;
674 
675 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
676 	ifra.ifra_addr.sin6_family = AF_INET6;
677 	ifra.ifra_addr.sin6_addr = in6addr_loopback;
678 
679 	/* the loopback  address should NEVER expire. */
680 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
681 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
682 
683 	/* we don't need to perform DAD on loopback interfaces. */
684 	ifra.ifra_flags |= IN6_IFF_NODAD;
685 
686 	/*
687 	 * We are sure that this is a newly assigned address, so we can set
688 	 * NULL to the 3rd arg.
689 	 */
690 	if ((error = in6_update_ifa(ifp, &ifra, NULL, 0)) != 0) {
691 		nd6log((LOG_ERR, "in6_ifattach_loopback: failed to configure "
692 		    "the loopback address on %s (errno=%d)\n",
693 		    if_name(ifp), error));
694 		return (-1);
695 	}
696 
697 	return 0;
698 }
699 
700 /*
701  * compute NI group address, based on the current hostname setting.
702  * see draft-ietf-ipngwg-icmp-name-lookup-* (04 and later).
703  *
704  * when ifp == NULL, the caller is responsible for filling scopeid.
705  */
706 int
707 in6_nigroup(ifp, name, namelen, sa6)
708 	struct ifnet *ifp;
709 	const char *name;
710 	int namelen;
711 	struct sockaddr_in6 *sa6;
712 {
713 	const char *p;
714 	u_int8_t *q;
715 	MD5_CTX ctxt;
716 	u_int8_t digest[16];
717 	u_int8_t l;
718 	u_int8_t n[64];	/* a single label must not exceed 63 chars */
719 
720 	if (!namelen || !name)
721 		return -1;
722 
723 	p = name;
724 	while (p && *p && *p != '.' && p - name < namelen)
725 		p++;
726 	if (p - name > sizeof(n) - 1)
727 		return -1;	/* label too long */
728 	l = p - name;
729 	strncpy((char *)n, name, l);
730 	n[(int)l] = '\0';
731 	for (q = n; *q; q++) {
732 		if ('A' <= *q && *q <= 'Z')
733 			*q = *q - 'A' + 'a';
734 	}
735 
736 	/* generate 8 bytes of pseudo-random value. */
737 	memset(&ctxt, 0, sizeof(ctxt));
738 	MD5Init(&ctxt);
739 	MD5Update(&ctxt, &l, sizeof(l));
740 	MD5Update(&ctxt, n, l);
741 	MD5Final(digest, &ctxt);
742 
743 	memset(sa6, 0, sizeof(*sa6));
744 	sa6->sin6_family = AF_INET6;
745 	sa6->sin6_len = sizeof(*sa6);
746 	sa6->sin6_addr.s6_addr16[0] = htons(0xff02);
747 	sa6->sin6_addr.s6_addr8[11] = 2;
748 	memcpy(&sa6->sin6_addr.s6_addr32[3], digest,
749 	    sizeof(sa6->sin6_addr.s6_addr32[3]));
750 	if (in6_setscope(&sa6->sin6_addr, ifp, NULL))
751 		return (-1); /* XXX: should not fail */
752 
753 	return 0;
754 }
755 
756 /*
757  * XXX multiple loopback interface needs more care.  for instance,
758  * nodelocal address needs to be configured onto only one of them.
759  * XXX multiple link-local address case
760  */
761 void
762 in6_ifattach(ifp, altifp)
763 	struct ifnet *ifp;
764 	struct ifnet *altifp;	/* secondary EUI64 source */
765 {
766 	struct in6_ifaddr *ia;
767 	struct in6_addr in6;
768 
769 	/* some of the interfaces are inherently not IPv6 capable */
770 	switch (ifp->if_type) {
771 	case IFT_BRIDGE:
772 #ifdef IFT_PFLOG
773 	case IFT_PFLOG:
774 #endif
775 #ifdef IFT_PFSYNC
776 	case IFT_PFSYNC:
777 #endif
778 		return;
779 	}
780 
781 	/*
782 	 * if link mtu is too small, don't try to configure IPv6.
783 	 * remember there could be some link-layer that has special
784 	 * fragmentation logic.
785 	 */
786 	if (ifp->if_mtu < IPV6_MMTU) {
787 		nd6log((LOG_INFO, "in6_ifattach: "
788 		    "%s has too small MTU, IPv6 not enabled\n",
789 		    if_name(ifp)));
790 		return;
791 	}
792 
793 	/* create a multicast kludge storage (if we have not had one) */
794 	in6_createmkludge(ifp);
795 
796 	/*
797 	 * quirks based on interface type
798 	 */
799 	switch (ifp->if_type) {
800 #ifdef IFT_STF
801 	case IFT_STF:
802 		/*
803 		 * 6to4 interface is a very special kind of beast.
804 		 * no multicast, no linklocal.  RFC2529 specifies how to make
805 		 * linklocals for 6to4 interface, but there's no use and
806 		 * it is rather harmful to have one.
807 		 */
808 		return;
809 #endif
810 	case IFT_CARP:
811 		return;
812 	default:
813 		break;
814 	}
815 
816 	/*
817 	 * usually, we require multicast capability to the interface
818 	 */
819 	if ((ifp->if_flags & IFF_MULTICAST) == 0) {
820 		nd6log((LOG_INFO, "in6_ifattach: "
821 		    "%s is not multicast capable, IPv6 not enabled\n",
822 		    if_name(ifp)));
823 		return;
824 	}
825 
826 	/*
827 	 * assign loopback address for loopback interface.
828 	 * XXX multiple loopback interface case.
829 	 */
830 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
831 		in6 = in6addr_loopback;
832 		if (in6ifa_ifpwithaddr(ifp, &in6) == NULL) {
833 			if (in6_ifattach_loopback(ifp) != 0)
834 				return;
835 		}
836 	}
837 
838 	/*
839 	 * assign a link-local address, if there's none.
840 	 */
841 	if (ip6_auto_linklocal) {
842 		ia = in6ifa_ifpforlinklocal(ifp, 0);
843 		if (ia == NULL) {
844 			if (in6_ifattach_linklocal(ifp, altifp) == 0) {
845 				/* linklocal address assigned */
846 			} else {
847 				/* failed to assign linklocal address. bark? */
848 			}
849 		}
850 	}
851 }
852 
853 /*
854  * NOTE: in6_ifdetach() does not support loopback if at this moment.
855  * We don't need this function in bsdi, because interfaces are never removed
856  * from the ifnet list in bsdi.
857  */
858 void
859 in6_ifdetach(ifp)
860 	struct ifnet *ifp;
861 {
862 	struct in6_ifaddr *ia, *oia;
863 	struct ifaddr *ifa, *next;
864 	struct rtentry *rt;
865 	short rtflags;
866 	struct in6_multi_mship *imm;
867 
868 	/* remove ip6_mrouter stuff */
869 	ip6_mrouter_detach(ifp);
870 
871 	/* remove neighbor management table */
872 	nd6_purge(ifp);
873 
874 	/* nuke any of IPv6 addresses we have */
875 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = next)
876 	{
877 		next = ifa->ifa_list.tqe_next;
878 		if (ifa->ifa_addr->sa_family != AF_INET6)
879 			continue;
880 		in6_purgeaddr(ifa);
881 	}
882 
883 	/* undo everything done by in6_ifattach(), just in case */
884 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = next)
885 	{
886 		next = ifa->ifa_list.tqe_next;
887 
888 		if (ifa->ifa_addr->sa_family != AF_INET6
889 		 || !IN6_IS_ADDR_LINKLOCAL(&satosin6(&ifa->ifa_addr)->sin6_addr)) {
890 			continue;
891 		}
892 
893 		ia = (struct in6_ifaddr *)ifa;
894 
895 		/*
896 		 * leave from multicast groups we have joined for the interface
897 		 */
898 		while ((imm = ia->ia6_memberships.lh_first) != NULL) {
899 			LIST_REMOVE(imm, i6mm_chain);
900 			in6_leavegroup(imm);
901 		}
902 
903 		/* remove from the routing table */
904 		if ((ia->ia_flags & IFA_ROUTE) &&
905 		    (rt = rtalloc1((struct sockaddr *)&ia->ia_addr, 0))) {
906 			rtflags = rt->rt_flags;
907 			rtfree(rt);
908 			rtrequest(RTM_DELETE, (struct sockaddr *)&ia->ia_addr,
909 			    (struct sockaddr *)&ia->ia_addr,
910 			    (struct sockaddr *)&ia->ia_prefixmask,
911 			    rtflags, (struct rtentry **)0);
912 		}
913 
914 		/* remove from the linked list */
915 		TAILQ_REMOVE(&ifp->if_addrlist, (struct ifaddr *)ia, ifa_list);
916 		IFAFREE(&ia->ia_ifa);
917 
918 		/* also remove from the IPv6 address chain(itojun&jinmei) */
919 		oia = ia;
920 		if (oia == (ia = in6_ifaddr))
921 			in6_ifaddr = ia->ia_next;
922 		else {
923 			while (ia->ia_next && (ia->ia_next != oia))
924 				ia = ia->ia_next;
925 			if (ia->ia_next)
926 				ia->ia_next = oia->ia_next;
927 			else {
928 				nd6log((LOG_ERR,
929 				    "%s: didn't unlink in6ifaddr from list\n",
930 				    if_name(ifp)));
931 			}
932 		}
933 
934 		IFAFREE(&oia->ia_ifa);
935 	}
936 
937 	/* cleanup multicast address kludge table, if there is any */
938 	in6_purgemkludge(ifp);
939 
940 	/*
941 	 * remove neighbor management table.  we call it twice just to make
942 	 * sure we nuke everything.  maybe we need just one call.
943 	 * XXX: since the first call did not release addresses, some prefixes
944 	 * might remain.  We should call nd6_purge() again to release the
945 	 * prefixes after removing all addresses above.
946 	 * (Or can we just delay calling nd6_purge until at this point?)
947 	 */
948 	nd6_purge(ifp);
949 }
950 
951 int
952 in6_get_tmpifid(ifp, retbuf, baseid, generate)
953 	struct ifnet *ifp;
954 	u_int8_t *retbuf;
955 	const u_int8_t *baseid;
956 	int generate;
957 {
958 	u_int8_t nullbuf[8];
959 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
960 
961 	memset(nullbuf, 0, sizeof(nullbuf));
962 	if (memcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
963 		/* we've never created a random ID.  Create a new one. */
964 		generate = 1;
965 	}
966 
967 	if (generate) {
968 		memcpy(ndi->randomseed1, baseid, sizeof(ndi->randomseed1));
969 
970 		/* generate_tmp_ifid will update seedn and buf */
971 		(void)generate_tmp_ifid(ndi->randomseed0, ndi->randomseed1,
972 		    ndi->randomid);
973 	}
974 	memcpy(retbuf, ndi->randomid, 8);
975 	if (generate && memcmp(retbuf, nullbuf, sizeof(nullbuf)) == 0) {
976 		/* generate_tmp_ifid could not found a good ID. */
977 		return (-1);
978 	}
979 
980 	return (0);
981 }
982 
983 void
984 in6_tmpaddrtimer(ignored_arg)
985 	void *ignored_arg;
986 {
987 	struct nd_ifinfo *ndi;
988 	u_int8_t nullbuf[8];
989 	struct ifnet *ifp;
990 	int s = splsoftnet();
991 
992 	callout_reset(&in6_tmpaddrtimer_ch,
993 	    (ip6_temp_preferred_lifetime - ip6_desync_factor -
994 	    ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, NULL);
995 
996 	memset(nullbuf, 0, sizeof(nullbuf));
997 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
998 		ndi = ND_IFINFO(ifp);
999 		if (memcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
1000 			/*
1001 			 * We've been generating a random ID on this interface.
1002 			 * Create a new one.
1003 			 */
1004 			(void)generate_tmp_ifid(ndi->randomseed0,
1005 			    ndi->randomseed1, ndi->randomid);
1006 		}
1007 	}
1008 
1009 	splx(s);
1010 }
1011