xref: /netbsd-src/sys/netinet6/in6_ifattach.c (revision ce2c90c7c172d95d2402a5b3d96d8f8e6d138a21)
1 /*	$NetBSD: in6_ifattach.c,v 1.66 2006/10/12 01:32:39 christos 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 1.66 2006/10/12 01:32:39 christos 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(struct ifnet *ifp __unused,
143 	struct in6_addr *in6)	/* upper 64bits are preserved */
144 {
145 	MD5_CTX ctxt;
146 	u_int8_t digest[16];
147 
148 #if 0
149 	/* we need at least several letters as seed for ifid */
150 	if (hostnamelen < 3)
151 		return -1;
152 #endif
153 
154 	/* generate 8 bytes of pseudo-random value. */
155 	memset(&ctxt, 0, sizeof(ctxt));
156 	MD5Init(&ctxt);
157 	MD5Update(&ctxt, (u_char *)hostname, hostnamelen);
158 	MD5Final(digest, &ctxt);
159 
160 	/* assumes sizeof(digest) > sizeof(ifid) */
161 	memcpy(&in6->s6_addr[8], digest, 8);
162 
163 	/* make sure to set "u" bit to local, and "g" bit to individual. */
164 	in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
165 	in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
166 
167 	/* convert EUI64 into IPv6 interface identifier */
168 	EUI64_TO_IFID(in6);
169 
170 	return 0;
171 }
172 
173 static int
174 generate_tmp_ifid(seed0, seed1, ret)
175 	u_int8_t *seed0, *ret;
176 	const u_int8_t *seed1;
177 {
178 	MD5_CTX ctxt;
179 	u_int8_t seed[16], digest[16], nullbuf[8];
180 	u_int32_t val32;
181 	/*
182 	 * interface ID for subnet anycast addresses.
183 	 * XXX: we assume the unicast address range that requires IDs
184 	 * in EUI-64 format.
185 	 */
186 	static const uint8_t anycast_id[8] = { 0xfd, 0xff, 0xff, 0xff,
187 	    0xff, 0xff, 0xff, 0x80 };
188 	static const uint8_t isatap_id[4] = { 0x00, 0x00, 0x5e, 0xfe };
189 	int badid, retry = 0;
190 
191 	/* If there's no hisotry, start with a random seed. */
192 	memset(nullbuf, 0, sizeof(nullbuf));
193 	if (memcmp(nullbuf, seed0, sizeof(nullbuf)) == 0) {
194 		int i;
195 
196 		for (i = 0; i < 2; i++) {
197 			val32 = arc4random();
198 			memcpy(seed + sizeof(val32) * i, &val32, sizeof(val32));
199 		}
200 	} else
201 		memcpy(seed, seed0, 8);
202 
203 	/* copy the right-most 64-bits of the given address */
204 	/* XXX assumption on the size of IFID */
205 	memcpy(&seed[8], seed1, 8);
206 
207   again:
208 	/* for debugging purposes only */
209 #if 0
210 	{
211 		int i;
212 
213 		printf("generate_tmp_ifid: new randomized ID from: ");
214 		for (i = 0; i < 16; i++)
215 			printf("%02x", seed[i]);
216 		printf(" ");
217 	}
218 #endif
219 
220 	/* generate 16 bytes of pseudo-random value. */
221 	memset(&ctxt, 0, sizeof(ctxt));
222 	MD5Init(&ctxt);
223 	MD5Update(&ctxt, seed, sizeof(seed));
224 	MD5Final(digest, &ctxt);
225 
226 	/*
227 	 * draft-ietf-ipngwg-temp-addresses-v2-00.txt 3.2.1. (3)
228 	 * Take the left-most 64-bits of the MD5 digest and set bit 6 (the
229 	 * left-most bit is numbered 0) to zero.
230 	 */
231 	memcpy(ret, digest, 8);
232 	ret[0] &= ~EUI64_UBIT;
233 
234 	/*
235 	 * Reject inappropriate identifiers according to
236 	 * draft-ietf-ipngwg-temp-addresses-v2-00.txt 3.2.1. (4)
237 	 * At this moment, we reject following cases:
238 	 * - all 0 identifier
239 	 * - identifiers that conflict with reserved subnet anycast addresses,
240 	 *   which are defined in RFC 2526.
241 	 * - identifiers that conflict with ISATAP addresses
242 	 * - identifiers used in our own addresses
243 	 */
244 	badid = 0;
245 	if (memcmp(nullbuf, ret, sizeof(nullbuf)) == 0)
246 		badid = 1;
247 	else if (memcmp(anycast_id, ret, 7) == 0 &&
248 	    (anycast_id[7] & ret[7]) == anycast_id[7]) {
249 		badid = 1;
250 	} else if (memcmp(isatap_id, ret, sizeof(isatap_id)) == 0)
251 		badid = 1;
252 	else {
253 		struct in6_ifaddr *ia;
254 
255 		for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
256 			if (!memcmp(&ia->ia_addr.sin6_addr.s6_addr[8],
257 			    ret, 8)) {
258 				badid = 1;
259 				break;
260 			}
261 		}
262 	}
263 
264 	/*
265 	 * In the event that an unacceptable identifier has been generated,
266 	 * restart the process, using the right-most 64 bits of the MD5 digest
267 	 * obtained in place of the history value.
268 	 */
269 	if (badid) {
270 		/* for debugging purposes only */
271 #if 0
272 		{
273 			int i;
274 
275 			printf("unacceptable random ID: ");
276 			for (i = 0; i < 16; i++)
277 				printf("%02x", digest[i]);
278 			printf("\n");
279 		}
280 #endif
281 
282 		if (++retry < GEN_TEMPID_RETRY_MAX) {
283 			memcpy(seed, &digest[8], 8);
284 			goto again;
285 		} else {
286 			/*
287 			 * We're so unlucky.  Give up for now, and return
288 			 * all 0 IDs to tell the caller not to make a
289 			 * temporary address.
290 			 */
291 			nd6log((LOG_NOTICE,
292 			    "generate_tmp_ifid: never found a good ID\n"));
293 			memset(ret, 0, 8);
294 		}
295 	}
296 
297 	/*
298 	 * draft-ietf-ipngwg-temp-addresses-v2-00.txt 3.2.1. (6)
299 	 * Take the rightmost 64-bits of the MD5 digest and save them in
300 	 * stable storage as the history value to be used in the next
301 	 * iteration of the algorithm.
302 	 */
303 	memcpy(seed0, &digest[8], 8);
304 
305 	/* for debugging purposes only */
306 #if 0
307 	{
308 		int i;
309 
310 		printf("to: ");
311 		for (i = 0; i < 16; i++)
312 			printf("%02x", digest[i]);
313 		printf("\n");
314 	}
315 #endif
316 
317 	return 0;
318 }
319 /*
320  * Get interface identifier for the specified interface.
321  * XXX assumes single sockaddr_dl (AF_LINK address) per an interface
322  */
323 int
324 in6_get_hw_ifid(ifp, in6)
325 	struct ifnet *ifp;
326 	struct in6_addr *in6;	/* upper 64bits are preserved */
327 {
328 	struct ifaddr *ifa;
329 	struct sockaddr_dl *sdl;
330 	char *addr;
331 	size_t addrlen;
332 	static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
333 	static u_int8_t allone[8] =
334 		{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
335 
336 	for (ifa = ifp->if_addrlist.tqh_first;
337 	     ifa;
338 	     ifa = ifa->ifa_list.tqe_next)
339 	{
340 		if (ifa->ifa_addr->sa_family != AF_LINK)
341 			continue;
342 		sdl = (struct sockaddr_dl *)ifa->ifa_addr;
343 		if (sdl == NULL)
344 			continue;
345 		if (sdl->sdl_alen == 0)
346 			continue;
347 
348 		goto found;
349 	}
350 
351 	return -1;
352 
353 found:
354 	addr = LLADDR(sdl);
355 	addrlen = sdl->sdl_alen;
356 
357 	switch (ifp->if_type) {
358 	case IFT_IEEE1394:
359 	case IFT_IEEE80211:
360 		/* IEEE1394 uses 16byte length address starting with EUI64 */
361 		if (addrlen > 8)
362 			addrlen = 8;
363 		break;
364 	default:
365 		break;
366 	}
367 
368 	/* get EUI64 */
369 	switch (ifp->if_type) {
370 	/* IEEE802/EUI64 cases - what others? */
371 	case IFT_ETHER:
372 	case IFT_FDDI:
373 	case IFT_ATM:
374 	case IFT_IEEE1394:
375 	case IFT_IEEE80211:
376 		/* look at IEEE802/EUI64 only */
377 		if (addrlen != 8 && addrlen != 6)
378 			return -1;
379 
380 		/*
381 		 * check for invalid MAC address - on bsdi, we see it a lot
382 		 * since wildboar configures all-zero MAC on pccard before
383 		 * card insertion.
384 		 */
385 		if (memcmp(addr, allzero, addrlen) == 0)
386 			return -1;
387 		if (memcmp(addr, allone, addrlen) == 0)
388 			return -1;
389 
390 		/* make EUI64 address */
391 		if (addrlen == 8)
392 			memcpy(&in6->s6_addr[8], addr, 8);
393 		else if (addrlen == 6) {
394 			in6->s6_addr[8] = addr[0];
395 			in6->s6_addr[9] = addr[1];
396 			in6->s6_addr[10] = addr[2];
397 			in6->s6_addr[11] = 0xff;
398 			in6->s6_addr[12] = 0xfe;
399 			in6->s6_addr[13] = addr[3];
400 			in6->s6_addr[14] = addr[4];
401 			in6->s6_addr[15] = addr[5];
402 		}
403 		break;
404 
405 	case IFT_ARCNET:
406 		if (addrlen != 1)
407 			return -1;
408 		if (!addr[0])
409 			return -1;
410 
411 		memset(&in6->s6_addr[8], 0, 8);
412 		in6->s6_addr[15] = addr[0];
413 
414 		/*
415 		 * due to insufficient bitwidth, we mark it local.
416 		 */
417 		in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
418 		in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
419 		break;
420 
421 	case IFT_GIF:
422 #ifdef IFT_STF
423 	case IFT_STF:
424 #endif
425 		/*
426 		 * RFC2893 says: "SHOULD use IPv4 address as ifid source".
427 		 * however, IPv4 address is not very suitable as unique
428 		 * identifier source (can be renumbered).
429 		 * we don't do this.
430 		 */
431 		return -1;
432 
433 	default:
434 		return -1;
435 	}
436 
437 	/* sanity check: g bit must not indicate "group" */
438 	if (EUI64_GROUP(in6))
439 		return -1;
440 
441 	/* convert EUI64 into IPv6 interface identifier */
442 	EUI64_TO_IFID(in6);
443 
444 	/*
445 	 * sanity check: ifid must not be all zero, avoid conflict with
446 	 * subnet router anycast
447 	 */
448 	if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
449 	    memcmp(&in6->s6_addr[9], allzero, 7) == 0) {
450 		return -1;
451 	}
452 
453 	return 0;
454 }
455 
456 /*
457  * Get interface identifier for the specified interface.  If it is not
458  * available on ifp0, borrow interface identifier from other information
459  * sources.
460  */
461 static int
462 get_ifid(ifp0, altifp, in6)
463 	struct ifnet *ifp0;
464 	struct ifnet *altifp;	/*secondary EUI64 source*/
465 	struct in6_addr *in6;
466 {
467 	struct ifnet *ifp;
468 
469 	/* first, try to get it from the interface itself */
470 	if (in6_get_hw_ifid(ifp0, in6) == 0) {
471 		nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n",
472 		    if_name(ifp0)));
473 		goto success;
474 	}
475 
476 	/* try secondary EUI64 source. this basically is for ATM PVC */
477 	if (altifp && in6_get_hw_ifid(altifp, in6) == 0) {
478 		nd6log((LOG_DEBUG, "%s: got interface identifier from %s\n",
479 		    if_name(ifp0), if_name(altifp)));
480 		goto success;
481 	}
482 
483 	/* next, try to get it from some other hardware interface */
484 	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_list.tqe_next)
485 	{
486 		if (ifp == ifp0)
487 			continue;
488 		if (in6_get_hw_ifid(ifp, in6) != 0)
489 			continue;
490 
491 		/*
492 		 * to borrow ifid from other interface, ifid needs to be
493 		 * globally unique
494 		 */
495 		if (IFID_UNIVERSAL(in6)) {
496 			nd6log((LOG_DEBUG,
497 			    "%s: borrow interface identifier from %s\n",
498 			    if_name(ifp0), if_name(ifp)));
499 			goto success;
500 		}
501 	}
502 
503 #if 0
504 	/* get from hostid - only for certain architectures */
505 	if (get_hostid_ifid(ifp, in6) == 0) {
506 		nd6log((LOG_DEBUG,
507 		    "%s: interface identifier generated by hostid\n",
508 		    if_name(ifp0)));
509 		goto success;
510 	}
511 #endif
512 
513 	/* last resort: get from random number source */
514 	if (get_rand_ifid(ifp, in6) == 0) {
515 		nd6log((LOG_DEBUG,
516 		    "%s: interface identifier generated by random number\n",
517 		    if_name(ifp0)));
518 		goto success;
519 	}
520 
521 	printf("%s: failed to get interface identifier\n", if_name(ifp0));
522 	return -1;
523 
524 success:
525 	nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
526 	    if_name(ifp0), in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10],
527 	    in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13],
528 	    in6->s6_addr[14], in6->s6_addr[15]));
529 	return 0;
530 }
531 
532 static int
533 in6_ifattach_linklocal(ifp, altifp)
534 	struct ifnet *ifp;
535 	struct ifnet *altifp;	/*secondary EUI64 source*/
536 {
537 	struct in6_ifaddr *ia;
538 	struct in6_aliasreq ifra;
539 	struct nd_prefixctl pr0;
540 	int i, error;
541 
542 	/*
543 	 * configure link-local address.
544 	 */
545 	memset(&ifra, 0, sizeof(ifra));
546 
547 	/*
548 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
549 	 * for safety.
550 	 */
551 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
552 
553 	ifra.ifra_addr.sin6_family = AF_INET6;
554 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
555 	ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000);
556 	ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
557 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
558 		ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
559 		ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
560 	} else {
561 		if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) {
562 			nd6log((LOG_ERR,
563 			    "%s: no ifid available\n", if_name(ifp)));
564 			return (-1);
565 		}
566 	}
567 	if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL))
568 		return (-1);
569 
570 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
571 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
572 	ifra.ifra_prefixmask.sin6_addr = in6mask64;
573 	/* link-local addresses should NEVER expire. */
574 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
575 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
576 
577 	/*
578 	 * Now call in6_update_ifa() to do a bunch of procedures to configure
579 	 * a link-local address. We can set NULL to the 3rd argument, because
580 	 * we know there's no other link-local address on the interface
581 	 * and therefore we are adding one (instead of updating one).
582 	 */
583 	if ((error = in6_update_ifa(ifp, &ifra, NULL,
584 	    IN6_IFAUPDATE_DADDELAY)) != 0) {
585 		/*
586 		 * XXX: When the interface does not support IPv6, this call
587 		 * would fail in the SIOCSIFADDR ioctl.  I believe the
588 		 * notification is rather confusing in this case, so just
589 		 * suppress it.  (jinmei@kame.net 20010130)
590 		 */
591 		if (error != EAFNOSUPPORT)
592 			nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to "
593 			    "configure a link-local address on %s "
594 			    "(errno=%d)\n",
595 			    if_name(ifp), error));
596 		return (-1);
597 	}
598 
599 	ia = in6ifa_ifpforlinklocal(ifp, 0); /* ia must not be NULL */
600 #ifdef DIAGNOSTIC
601 	if (!ia) {
602 		panic("ia == NULL in in6_ifattach_linklocal");
603 		/* NOTREACHED */
604 	}
605 #endif
606 
607 	/*
608 	 * Make the link-local prefix (fe80::/64%link) as on-link.
609 	 * Since we'd like to manage prefixes separately from addresses,
610 	 * we make an ND6 prefix structure for the link-local prefix,
611 	 * and add it to the prefix list as a never-expire prefix.
612 	 * XXX: this change might affect some existing code base...
613 	 */
614 	memset(&pr0, 0, sizeof(pr0));
615 	pr0.ndpr_ifp = ifp;
616 	/* this should be 64 at this moment. */
617 	pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
618 	pr0.ndpr_prefix = ifra.ifra_addr;
619 	/* apply the mask for safety. (nd6_prelist_add will apply it again) */
620 	for (i = 0; i < 4; i++) {
621 		pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
622 		    in6mask64.s6_addr32[i];
623 	}
624 	/*
625 	 * Initialize parameters.  The link-local prefix must always be
626 	 * on-link, and its lifetimes never expire.
627 	 */
628 	pr0.ndpr_raf_onlink = 1;
629 	pr0.ndpr_raf_auto = 1;	/* probably meaningless */
630 	pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
631 	pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
632 	/*
633 	 * Since there is no other link-local addresses, nd6_prefix_lookup()
634 	 * probably returns NULL.  However, we cannot always expect the result.
635 	 * For example, if we first remove the (only) existing link-local
636 	 * address, and then reconfigure another one, the prefix is still
637 	 * valid with referring to the old link-local address.
638 	 */
639 	if (nd6_prefix_lookup(&pr0) == NULL) {
640 		if ((error = nd6_prelist_add(&pr0, NULL, NULL)) != 0)
641 			return (error);
642 	}
643 
644 	return 0;
645 }
646 
647 static int
648 in6_ifattach_loopback(ifp)
649 	struct ifnet *ifp;	/* must be IFT_LOOP */
650 {
651 	struct in6_aliasreq ifra;
652 	int error;
653 
654 	memset(&ifra, 0, sizeof(ifra));
655 
656 	/*
657 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
658 	 * for safety.
659 	 */
660 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
661 
662 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
663 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
664 	ifra.ifra_prefixmask.sin6_addr = in6mask128;
665 
666 	/*
667 	 * Always initialize ia_dstaddr (= broadcast address) to loopback
668 	 * address.  Follows IPv4 practice - see in_ifinit().
669 	 */
670 	ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
671 	ifra.ifra_dstaddr.sin6_family = AF_INET6;
672 	ifra.ifra_dstaddr.sin6_addr = in6addr_loopback;
673 
674 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
675 	ifra.ifra_addr.sin6_family = AF_INET6;
676 	ifra.ifra_addr.sin6_addr = in6addr_loopback;
677 
678 	/* the loopback  address should NEVER expire. */
679 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
680 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
681 
682 	/* we don't need to perform DAD on loopback interfaces. */
683 	ifra.ifra_flags |= IN6_IFF_NODAD;
684 
685 	/*
686 	 * We are sure that this is a newly assigned address, so we can set
687 	 * NULL to the 3rd arg.
688 	 */
689 	if ((error = in6_update_ifa(ifp, &ifra, NULL, 0)) != 0) {
690 		nd6log((LOG_ERR, "in6_ifattach_loopback: failed to configure "
691 		    "the loopback address on %s (errno=%d)\n",
692 		    if_name(ifp), error));
693 		return (-1);
694 	}
695 
696 	return 0;
697 }
698 
699 /*
700  * compute NI group address, based on the current hostname setting.
701  * see draft-ietf-ipngwg-icmp-name-lookup-* (04 and later).
702  *
703  * when ifp == NULL, the caller is responsible for filling scopeid.
704  */
705 int
706 in6_nigroup(ifp, name, namelen, sa6)
707 	struct ifnet *ifp;
708 	const char *name;
709 	int namelen;
710 	struct sockaddr_in6 *sa6;
711 {
712 	const char *p;
713 	u_int8_t *q;
714 	MD5_CTX ctxt;
715 	u_int8_t digest[16];
716 	u_int8_t l;
717 	u_int8_t n[64];	/* a single label must not exceed 63 chars */
718 
719 	if (!namelen || !name)
720 		return -1;
721 
722 	p = name;
723 	while (p && *p && *p != '.' && p - name < namelen)
724 		p++;
725 	if (p - name > sizeof(n) - 1)
726 		return -1;	/* label too long */
727 	l = p - name;
728 	strncpy((char *)n, name, l);
729 	n[(int)l] = '\0';
730 	for (q = n; *q; q++) {
731 		if ('A' <= *q && *q <= 'Z')
732 			*q = *q - 'A' + 'a';
733 	}
734 
735 	/* generate 8 bytes of pseudo-random value. */
736 	memset(&ctxt, 0, sizeof(ctxt));
737 	MD5Init(&ctxt);
738 	MD5Update(&ctxt, &l, sizeof(l));
739 	MD5Update(&ctxt, n, l);
740 	MD5Final(digest, &ctxt);
741 
742 	memset(sa6, 0, sizeof(*sa6));
743 	sa6->sin6_family = AF_INET6;
744 	sa6->sin6_len = sizeof(*sa6);
745 	sa6->sin6_addr.s6_addr16[0] = htons(0xff02);
746 	sa6->sin6_addr.s6_addr8[11] = 2;
747 	memcpy(&sa6->sin6_addr.s6_addr32[3], digest,
748 	    sizeof(sa6->sin6_addr.s6_addr32[3]));
749 	if (in6_setscope(&sa6->sin6_addr, ifp, NULL))
750 		return (-1); /* XXX: should not fail */
751 
752 	return 0;
753 }
754 
755 /*
756  * XXX multiple loopback interface needs more care.  for instance,
757  * nodelocal address needs to be configured onto only one of them.
758  * XXX multiple link-local address case
759  */
760 void
761 in6_ifattach(ifp, altifp)
762 	struct ifnet *ifp;
763 	struct ifnet *altifp;	/* secondary EUI64 source */
764 {
765 	struct in6_ifaddr *ia;
766 	struct in6_addr in6;
767 
768 	/* some of the interfaces are inherently not IPv6 capable */
769 	switch (ifp->if_type) {
770 	case IFT_BRIDGE:
771 #ifdef IFT_PFLOG
772 	case IFT_PFLOG:
773 #endif
774 #ifdef IFT_PFSYNC
775 	case IFT_PFSYNC:
776 #endif
777 		return;
778 	}
779 
780 	/*
781 	 * if link mtu is too small, don't try to configure IPv6.
782 	 * remember there could be some link-layer that has special
783 	 * fragmentation logic.
784 	 */
785 	if (ifp->if_mtu < IPV6_MMTU) {
786 		nd6log((LOG_INFO, "in6_ifattach: "
787 		    "%s has too small MTU, IPv6 not enabled\n",
788 		    if_name(ifp)));
789 		return;
790 	}
791 
792 	/* create a multicast kludge storage (if we have not had one) */
793 	in6_createmkludge(ifp);
794 
795 	/*
796 	 * quirks based on interface type
797 	 */
798 	switch (ifp->if_type) {
799 #ifdef IFT_STF
800 	case IFT_STF:
801 		/*
802 		 * 6to4 interface is a very special kind of beast.
803 		 * no multicast, no linklocal.  RFC2529 specifies how to make
804 		 * linklocals for 6to4 interface, but there's no use and
805 		 * it is rather harmful to have one.
806 		 */
807 		return;
808 #endif
809 	case IFT_CARP:
810 		return;
811 	default:
812 		break;
813 	}
814 
815 	/*
816 	 * usually, we require multicast capability to the interface
817 	 */
818 	if ((ifp->if_flags & IFF_MULTICAST) == 0) {
819 		nd6log((LOG_INFO, "in6_ifattach: "
820 		    "%s is not multicast capable, IPv6 not enabled\n",
821 		    if_name(ifp)));
822 		return;
823 	}
824 
825 	/*
826 	 * assign loopback address for loopback interface.
827 	 * XXX multiple loopback interface case.
828 	 */
829 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
830 		in6 = in6addr_loopback;
831 		if (in6ifa_ifpwithaddr(ifp, &in6) == NULL) {
832 			if (in6_ifattach_loopback(ifp) != 0)
833 				return;
834 		}
835 	}
836 
837 	/*
838 	 * assign a link-local address, if there's none.
839 	 */
840 	if (ip6_auto_linklocal) {
841 		ia = in6ifa_ifpforlinklocal(ifp, 0);
842 		if (ia == NULL) {
843 			if (in6_ifattach_linklocal(ifp, altifp) == 0) {
844 				/* linklocal address assigned */
845 			} else {
846 				/* failed to assign linklocal address. bark? */
847 			}
848 		}
849 	}
850 }
851 
852 /*
853  * NOTE: in6_ifdetach() does not support loopback if at this moment.
854  * We don't need this function in bsdi, because interfaces are never removed
855  * from the ifnet list in bsdi.
856  */
857 void
858 in6_ifdetach(ifp)
859 	struct ifnet *ifp;
860 {
861 	struct in6_ifaddr *ia, *oia;
862 	struct ifaddr *ifa, *next;
863 	struct rtentry *rt;
864 	short rtflags;
865 	struct in6_multi_mship *imm;
866 
867 	/* remove ip6_mrouter stuff */
868 	ip6_mrouter_detach(ifp);
869 
870 	/* remove neighbor management table */
871 	nd6_purge(ifp);
872 
873 	/* nuke any of IPv6 addresses we have */
874 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = next)
875 	{
876 		next = ifa->ifa_list.tqe_next;
877 		if (ifa->ifa_addr->sa_family != AF_INET6)
878 			continue;
879 		in6_purgeaddr(ifa);
880 	}
881 
882 	/* undo everything done by in6_ifattach(), just in case */
883 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = next)
884 	{
885 		next = ifa->ifa_list.tqe_next;
886 
887 		if (ifa->ifa_addr->sa_family != AF_INET6
888 		 || !IN6_IS_ADDR_LINKLOCAL(&satosin6(&ifa->ifa_addr)->sin6_addr)) {
889 			continue;
890 		}
891 
892 		ia = (struct in6_ifaddr *)ifa;
893 
894 		/*
895 		 * leave from multicast groups we have joined for the interface
896 		 */
897 		while ((imm = ia->ia6_memberships.lh_first) != NULL) {
898 			LIST_REMOVE(imm, i6mm_chain);
899 			in6_leavegroup(imm);
900 		}
901 
902 		/* remove from the routing table */
903 		if ((ia->ia_flags & IFA_ROUTE) &&
904 		    (rt = rtalloc1((struct sockaddr *)&ia->ia_addr, 0))) {
905 			rtflags = rt->rt_flags;
906 			rtfree(rt);
907 			rtrequest(RTM_DELETE, (struct sockaddr *)&ia->ia_addr,
908 			    (struct sockaddr *)&ia->ia_addr,
909 			    (struct sockaddr *)&ia->ia_prefixmask,
910 			    rtflags, (struct rtentry **)0);
911 		}
912 
913 		/* remove from the linked list */
914 		TAILQ_REMOVE(&ifp->if_addrlist, (struct ifaddr *)ia, ifa_list);
915 		IFAFREE(&ia->ia_ifa);
916 
917 		/* also remove from the IPv6 address chain(itojun&jinmei) */
918 		oia = ia;
919 		if (oia == (ia = in6_ifaddr))
920 			in6_ifaddr = ia->ia_next;
921 		else {
922 			while (ia->ia_next && (ia->ia_next != oia))
923 				ia = ia->ia_next;
924 			if (ia->ia_next)
925 				ia->ia_next = oia->ia_next;
926 			else {
927 				nd6log((LOG_ERR,
928 				    "%s: didn't unlink in6ifaddr from list\n",
929 				    if_name(ifp)));
930 			}
931 		}
932 
933 		IFAFREE(&oia->ia_ifa);
934 	}
935 
936 	/* cleanup multicast address kludge table, if there is any */
937 	in6_purgemkludge(ifp);
938 
939 	/*
940 	 * remove neighbor management table.  we call it twice just to make
941 	 * sure we nuke everything.  maybe we need just one call.
942 	 * XXX: since the first call did not release addresses, some prefixes
943 	 * might remain.  We should call nd6_purge() again to release the
944 	 * prefixes after removing all addresses above.
945 	 * (Or can we just delay calling nd6_purge until at this point?)
946 	 */
947 	nd6_purge(ifp);
948 }
949 
950 int
951 in6_get_tmpifid(ifp, retbuf, baseid, generate)
952 	struct ifnet *ifp;
953 	u_int8_t *retbuf;
954 	const u_int8_t *baseid;
955 	int generate;
956 {
957 	u_int8_t nullbuf[8];
958 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
959 
960 	memset(nullbuf, 0, sizeof(nullbuf));
961 	if (memcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
962 		/* we've never created a random ID.  Create a new one. */
963 		generate = 1;
964 	}
965 
966 	if (generate) {
967 		memcpy(ndi->randomseed1, baseid, sizeof(ndi->randomseed1));
968 
969 		/* generate_tmp_ifid will update seedn and buf */
970 		(void)generate_tmp_ifid(ndi->randomseed0, ndi->randomseed1,
971 		    ndi->randomid);
972 	}
973 	memcpy(retbuf, ndi->randomid, 8);
974 	if (generate && memcmp(retbuf, nullbuf, sizeof(nullbuf)) == 0) {
975 		/* generate_tmp_ifid could not found a good ID. */
976 		return (-1);
977 	}
978 
979 	return (0);
980 }
981 
982 void
983 in6_tmpaddrtimer(void *ignored_arg __unused)
984 {
985 	struct nd_ifinfo *ndi;
986 	u_int8_t nullbuf[8];
987 	struct ifnet *ifp;
988 	int s = splsoftnet();
989 
990 	callout_reset(&in6_tmpaddrtimer_ch,
991 	    (ip6_temp_preferred_lifetime - ip6_desync_factor -
992 	    ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, NULL);
993 
994 	memset(nullbuf, 0, sizeof(nullbuf));
995 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
996 		ndi = ND_IFINFO(ifp);
997 		if (memcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
998 			/*
999 			 * We've been generating a random ID on this interface.
1000 			 * Create a new one.
1001 			 */
1002 			(void)generate_tmp_ifid(ndi->randomseed0,
1003 			    ndi->randomseed1, ndi->randomid);
1004 		}
1005 	}
1006 
1007 	splx(s);
1008 }
1009