xref: /freebsd/sys/netinet6/in6_ifattach.c (revision 35a04710d7286aa9538917fd7f8e417dbee95b82)
1 /*	$FreeBSD$	*/
2 /*	$KAME: in6_ifattach.c,v 1.118 2001/05/24 07:44:00 itojun 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/param.h>
34 #include <sys/systm.h>
35 #include <sys/malloc.h>
36 #include <sys/socket.h>
37 #include <sys/sockio.h>
38 #include <sys/kernel.h>
39 #include <sys/syslog.h>
40 #include <sys/md5.h>
41 
42 #include <net/if.h>
43 #include <net/if_dl.h>
44 #include <net/if_types.h>
45 #include <net/route.h>
46 
47 #include <netinet/in.h>
48 #include <netinet/in_var.h>
49 #include <netinet/if_ether.h>
50 #include <netinet/in_pcb.h>
51 
52 #include <netinet/ip6.h>
53 #include <netinet6/ip6_var.h>
54 #include <netinet6/in6_var.h>
55 #include <netinet6/in6_pcb.h>
56 #include <netinet6/in6_ifattach.h>
57 #include <netinet6/ip6_var.h>
58 #include <netinet6/nd6.h>
59 #include <netinet6/scope6_var.h>
60 
61 unsigned long in6_maxmtu = 0;
62 
63 #ifdef IP6_AUTO_LINKLOCAL
64 int ip6_auto_linklocal = IP6_AUTO_LINKLOCAL;
65 #else
66 int ip6_auto_linklocal = 1;	/* enable by default */
67 #endif
68 
69 struct callout in6_tmpaddrtimer_ch;
70 
71 extern struct inpcbinfo udbinfo;
72 extern struct inpcbinfo ripcbinfo;
73 
74 static int get_rand_ifid __P((struct ifnet *, struct in6_addr *));
75 static int generate_tmp_ifid __P((u_int8_t *, const u_int8_t *, u_int8_t *));
76 static int get_ifid __P((struct ifnet *, struct ifnet *, struct in6_addr *));
77 static int in6_ifattach_linklocal __P((struct ifnet *, struct ifnet *));
78 static int in6_ifattach_loopback __P((struct ifnet *));
79 static void in6_purgemaddrs __P((struct ifnet *));
80 
81 #define EUI64_GBIT	0x01
82 #define EUI64_UBIT	0x02
83 #define EUI64_TO_IFID(in6)	do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (0)
84 #define EUI64_GROUP(in6)	((in6)->s6_addr[8] & EUI64_GBIT)
85 #define EUI64_INDIVIDUAL(in6)	(!EUI64_GROUP(in6))
86 #define EUI64_LOCAL(in6)	((in6)->s6_addr[8] & EUI64_UBIT)
87 #define EUI64_UNIVERSAL(in6)	(!EUI64_LOCAL(in6))
88 
89 #define IFID_LOCAL(in6)		(!EUI64_LOCAL(in6))
90 #define IFID_UNIVERSAL(in6)	(!EUI64_UNIVERSAL(in6))
91 
92 /*
93  * Generate a last-resort interface identifier, when the machine has no
94  * IEEE802/EUI64 address sources.
95  * The goal here is to get an interface identifier that is
96  * (1) random enough and (2) does not change across reboot.
97  * We currently use MD5(hostname) for it.
98  *
99  * in6 - upper 64bits are preserved
100  */
101 static int
102 get_rand_ifid(struct ifnet *ifp, struct in6_addr *in6)
103 {
104 	MD5_CTX ctxt;
105 	u_int8_t digest[16];
106 	int hostnamelen	= strlen(hostname);
107 
108 #if 0
109 	/* we need at least several letters as seed for ifid */
110 	if (hostnamelen < 3)
111 		return -1;
112 #endif
113 
114 	/* generate 8 bytes of pseudo-random value. */
115 	bzero(&ctxt, sizeof(ctxt));
116 	MD5Init(&ctxt);
117 	MD5Update(&ctxt, hostname, hostnamelen);
118 	MD5Final(digest, &ctxt);
119 
120 	/* assumes sizeof(digest) > sizeof(ifid) */
121 	bcopy(digest, &in6->s6_addr[8], 8);
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 
133 static int
134 generate_tmp_ifid(u_int8_t *seed0, const u_int8_t *seed1, u_int8_t *ret)
135 {
136 	MD5_CTX ctxt;
137 	u_int8_t seed[16], digest[16], nullbuf[8];
138 	u_int32_t val32;
139 
140 	/* If there's no history, start with a random seed. */
141 	bzero(nullbuf, sizeof(nullbuf));
142 	if (bcmp(nullbuf, seed0, sizeof(nullbuf)) == 0) {
143 		int i;
144 
145 		for (i = 0; i < 2; i++) {
146 			val32 = arc4random();
147 			bcopy(&val32, seed + sizeof(val32) * i, sizeof(val32));
148 		}
149 	} else
150 		bcopy(seed0, seed, 8);
151 
152 	/* copy the right-most 64-bits of the given address */
153 	/* XXX assumption on the size of IFID */
154 	bcopy(seed1, &seed[8], 8);
155 
156 	if (0) {		/* for debugging purposes only */
157 		int i;
158 
159 		printf("generate_tmp_ifid: new randomized ID from: ");
160 		for (i = 0; i < 16; i++)
161 			printf("%02x", seed[i]);
162 		printf(" ");
163 	}
164 
165 	/* generate 16 bytes of pseudo-random value. */
166 	bzero(&ctxt, sizeof(ctxt));
167 	MD5Init(&ctxt);
168 	MD5Update(&ctxt, seed, sizeof(seed));
169 	MD5Final(digest, &ctxt);
170 
171 	/*
172 	 * RFC 3041 3.2.1. (3)
173 	 * Take the left-most 64-bits of the MD5 digest and set bit 6 (the
174 	 * left-most bit is numbered 0) to zero.
175 	 */
176 	bcopy(digest, ret, 8);
177 	ret[0] &= ~EUI64_UBIT;
178 
179 	/*
180 	 * XXX: we'd like to ensure that the generated value is not zero
181 	 * for simplicity.  If the caclculated digest happens to be zero,
182 	 * use a random non-zero value as the last resort.
183 	 */
184 	if (bcmp(nullbuf, ret, sizeof(nullbuf)) == 0) {
185 		nd6log((LOG_INFO,
186 		    "generate_tmp_ifid: computed MD5 value is zero.\n"));
187 
188 		val32 = arc4random();
189 		val32 = 1 + (val32 % (0xffffffff - 1));
190 	}
191 
192 	/*
193 	 * RFC 3041 3.2.1. (4)
194 	 * Take the rightmost 64-bits of the MD5 digest and save them in
195 	 * stable storage as the history value to be used in the next
196 	 * iteration of the algorithm.
197 	 */
198 	bcopy(&digest[8], seed0, 8);
199 
200 	if (0) {		/* for debugging purposes only */
201 		int i;
202 
203 		printf("to: ");
204 		for (i = 0; i < 16; i++)
205 			printf("%02x", digest[i]);
206 		printf("\n");
207 	}
208 
209 	return 0;
210 }
211 
212 /*
213  * Get interface identifier for the specified interface.
214  * XXX assumes single sockaddr_dl (AF_LINK address) per an interface
215  *
216  * in6 - upper 64bits are preserved
217  */
218 int
219 in6_get_hw_ifid(struct ifnet *ifp, struct in6_addr *in6)
220 {
221 	struct ifaddr *ifa;
222 	struct sockaddr_dl *sdl;
223 	u_int8_t *addr;
224 	size_t addrlen;
225 	static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
226 	static u_int8_t allone[8] =
227 		{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
228 
229 	for (ifa = ifp->if_addrlist.tqh_first;
230 	     ifa;
231 	     ifa = ifa->ifa_list.tqe_next) {
232 		if (ifa->ifa_addr->sa_family != AF_LINK)
233 			continue;
234 		sdl = (struct sockaddr_dl *)ifa->ifa_addr;
235 		if (sdl == NULL)
236 			continue;
237 		if (sdl->sdl_alen == 0)
238 			continue;
239 
240 		goto found;
241 	}
242 
243 	return -1;
244 
245 found:
246 	addr = LLADDR(sdl);
247 	addrlen = sdl->sdl_alen;
248 
249 	/* get EUI64 */
250 	switch (ifp->if_type) {
251 	case IFT_ETHER:
252 	case IFT_FDDI:
253 	case IFT_ISO88025:
254 	case IFT_ATM:
255 	case IFT_IEEE1394:
256 #ifdef IFT_IEEE80211
257 	case IFT_IEEE80211:
258 #endif
259 		/* IEEE802/EUI64 cases - what others? */
260 		/* IEEE1394 uses 16byte length address starting with EUI64 */
261 		if (addrlen > 8)
262 			addrlen = 8;
263 
264 		/* look at IEEE802/EUI64 only */
265 		if (addrlen != 8 && addrlen != 6)
266 			return -1;
267 
268 		/*
269 		 * check for invalid MAC address - on bsdi, we see it a lot
270 		 * since wildboar configures all-zero MAC on pccard before
271 		 * card insertion.
272 		 */
273 		if (bcmp(addr, allzero, addrlen) == 0)
274 			return -1;
275 		if (bcmp(addr, allone, addrlen) == 0)
276 			return -1;
277 
278 		/* make EUI64 address */
279 		if (addrlen == 8)
280 			bcopy(addr, &in6->s6_addr[8], 8);
281 		else if (addrlen == 6) {
282 			in6->s6_addr[8] = addr[0];
283 			in6->s6_addr[9] = addr[1];
284 			in6->s6_addr[10] = addr[2];
285 			in6->s6_addr[11] = 0xff;
286 			in6->s6_addr[12] = 0xfe;
287 			in6->s6_addr[13] = addr[3];
288 			in6->s6_addr[14] = addr[4];
289 			in6->s6_addr[15] = addr[5];
290 		}
291 		break;
292 
293 	case IFT_ARCNET:
294 		if (addrlen != 1)
295 			return -1;
296 		if (!addr[0])
297 			return -1;
298 
299 		bzero(&in6->s6_addr[8], 8);
300 		in6->s6_addr[15] = addr[0];
301 
302 		/*
303 		 * due to insufficient bitwidth, we mark it local.
304 		 */
305 		in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
306 		in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
307 		break;
308 
309 	case IFT_GIF:
310 #ifdef IFT_STF
311 	case IFT_STF:
312 #endif
313 		/*
314 		 * RFC2893 says: "SHOULD use IPv4 address as ifid source".
315 		 * however, IPv4 address is not very suitable as unique
316 		 * identifier source (can be renumbered).
317 		 * we don't do this.
318 		 */
319 		return -1;
320 
321 	default:
322 		return -1;
323 	}
324 
325 	/* sanity check: g bit must not indicate "group" */
326 	if (EUI64_GROUP(in6))
327 		return -1;
328 
329 	/* convert EUI64 into IPv6 interface identifier */
330 	EUI64_TO_IFID(in6);
331 
332 	/*
333 	 * sanity check: ifid must not be all zero, avoid conflict with
334 	 * subnet router anycast
335 	 */
336 	if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
337 	    bcmp(&in6->s6_addr[9], allzero, 7) == 0) {
338 		return -1;
339 	}
340 
341 	return 0;
342 }
343 
344 /*
345  * Get interface identifier for the specified interface.  If it is not
346  * available on ifp0, borrow interface identifier from other information
347  * sources.
348  *
349  * altifp - secondary EUI64 source
350  */
351 static int
352 get_ifid(struct ifnet *ifp0, struct ifnet *altifp,
353     struct in6_addr *in6)
354 {
355 	struct ifnet *ifp;
356 
357 	/* first, try to get it from the interface itself */
358 	if (in6_get_hw_ifid(ifp0, in6) == 0) {
359 		nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n",
360 		    if_name(ifp0)));
361 		goto success;
362 	}
363 
364 	/* try secondary EUI64 source. this basically is for ATM PVC */
365 	if (altifp && in6_get_hw_ifid(altifp, in6) == 0) {
366 		nd6log((LOG_DEBUG, "%s: got interface identifier from %s\n",
367 		    if_name(ifp0), if_name(altifp)));
368 		goto success;
369 	}
370 
371 	/* next, try to get it from some other hardware interface */
372 	IFNET_RLOCK();
373 	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_list.tqe_next) {
374 		if (ifp == ifp0)
375 			continue;
376 		if (in6_get_hw_ifid(ifp, in6) != 0)
377 			continue;
378 
379 		/*
380 		 * to borrow ifid from other interface, ifid needs to be
381 		 * globally unique
382 		 */
383 		if (IFID_UNIVERSAL(in6)) {
384 			nd6log((LOG_DEBUG,
385 			    "%s: borrow interface identifier from %s\n",
386 			    if_name(ifp0), if_name(ifp)));
387 			IFNET_RUNLOCK();
388 			goto success;
389 		}
390 	}
391 	IFNET_RUNLOCK();
392 
393 	/* last resort: get from random number source */
394 	if (get_rand_ifid(ifp, in6) == 0) {
395 		nd6log((LOG_DEBUG,
396 		    "%s: interface identifier generated by random number\n",
397 		    if_name(ifp0)));
398 		goto success;
399 	}
400 
401 	printf("%s: failed to get interface identifier\n", if_name(ifp0));
402 	return -1;
403 
404 success:
405 	nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
406 	    if_name(ifp0), in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10],
407 	    in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13],
408 	    in6->s6_addr[14], in6->s6_addr[15]));
409 	return 0;
410 }
411 
412 /*
413  * altifp - secondary EUI64 source
414  */
415 static int
416 in6_ifattach_linklocal(struct ifnet *ifp, struct ifnet *altifp)
417 {
418 	struct in6_ifaddr *ia;
419 	struct in6_aliasreq ifra;
420 	struct nd_prefixctl pr0;
421 	int i, error;
422 
423 	/*
424 	 * configure link-local address.
425 	 */
426 	bzero(&ifra, sizeof(ifra));
427 
428 	/*
429 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
430 	 * for safety.
431 	 */
432 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
433 
434 	ifra.ifra_addr.sin6_family = AF_INET6;
435 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
436 	ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000);
437 	ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
438 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
439 		ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
440 		ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
441 	} else {
442 		if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) {
443 			nd6log((LOG_ERR,
444 			    "%s: no ifid available\n", if_name(ifp)));
445 			return (-1);
446 		}
447 	}
448 	if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL))
449 		return (-1);
450 
451 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
452 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
453 	ifra.ifra_prefixmask.sin6_addr = in6mask64;
454 	/* link-local addresses should NEVER expire. */
455 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
456 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
457 
458 	/*
459 	 * Now call in6_update_ifa() to do a bunch of procedures to configure
460 	 * a link-local address. We can set the 3rd argument to NULL, because
461 	 * we know there's no other link-local address on the interface
462 	 * and therefore we are adding one (instead of updating one).
463 	 */
464 	if ((error = in6_update_ifa(ifp, &ifra, NULL,
465 				    IN6_IFAUPDATE_DADDELAY)) != 0) {
466 		/*
467 		 * XXX: When the interface does not support IPv6, this call
468 		 * would fail in the SIOCSIFADDR ioctl.  I believe the
469 		 * notification is rather confusing in this case, so just
470 		 * suppress it.  (jinmei@kame.net 20010130)
471 		 */
472 		if (error != EAFNOSUPPORT)
473 			nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to "
474 			    "configure a link-local address on %s "
475 			    "(errno=%d)\n",
476 			    if_name(ifp), error));
477 		return (-1);
478 	}
479 
480 	ia = in6ifa_ifpforlinklocal(ifp, 0); /* ia must not be NULL */
481 #ifdef DIAGNOSTIC
482 	if (!ia) {
483 		panic("ia == NULL in in6_ifattach_linklocal");
484 		/* NOTREACHED */
485 	}
486 #endif
487 
488 	/*
489 	 * Make the link-local prefix (fe80::%link/64) as on-link.
490 	 * Since we'd like to manage prefixes separately from addresses,
491 	 * we make an ND6 prefix structure for the link-local prefix,
492 	 * and add it to the prefix list as a never-expire prefix.
493 	 * XXX: this change might affect some existing code base...
494 	 */
495 	bzero(&pr0, sizeof(pr0));
496 	pr0.ndpr_ifp = ifp;
497 	/* this should be 64 at this moment. */
498 	pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
499 	pr0.ndpr_prefix = ifra.ifra_addr;
500 	/* apply the mask for safety. (nd6_prelist_add will apply it again) */
501 	for (i = 0; i < 4; i++) {
502 		pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
503 		    in6mask64.s6_addr32[i];
504 	}
505 	/*
506 	 * Initialize parameters.  The link-local prefix must always be
507 	 * on-link, and its lifetimes never expire.
508 	 */
509 	pr0.ndpr_raf_onlink = 1;
510 	pr0.ndpr_raf_auto = 1;	/* probably meaningless */
511 	pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
512 	pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
513 	/*
514 	 * Since there is no other link-local addresses, nd6_prefix_lookup()
515 	 * probably returns NULL.  However, we cannot always expect the result.
516 	 * For example, if we first remove the (only) existing link-local
517 	 * address, and then reconfigure another one, the prefix is still
518 	 * valid with referring to the old link-local address.
519 	 */
520 	if (nd6_prefix_lookup(&pr0) == NULL) {
521 		if ((error = nd6_prelist_add(&pr0, NULL, NULL)) != 0)
522 			return (error);
523 	}
524 
525 	return 0;
526 }
527 
528 /*
529  * ifp - must be IFT_LOOP
530  */
531 static int
532 in6_ifattach_loopback(struct ifnet *ifp)
533 {
534 	struct in6_aliasreq ifra;
535 	int error;
536 
537 	bzero(&ifra, sizeof(ifra));
538 
539 	/*
540 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
541 	 * for safety.
542 	 */
543 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
544 
545 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
546 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
547 	ifra.ifra_prefixmask.sin6_addr = in6mask128;
548 
549 	/*
550 	 * Always initialize ia_dstaddr (= broadcast address) to loopback
551 	 * address.  Follows IPv4 practice - see in_ifinit().
552 	 */
553 	ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
554 	ifra.ifra_dstaddr.sin6_family = AF_INET6;
555 	ifra.ifra_dstaddr.sin6_addr = in6addr_loopback;
556 
557 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
558 	ifra.ifra_addr.sin6_family = AF_INET6;
559 	ifra.ifra_addr.sin6_addr = in6addr_loopback;
560 
561 	/* the loopback  address should NEVER expire. */
562 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
563 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
564 
565 	/* we don't need to perform DAD on loopback interfaces. */
566 	ifra.ifra_flags |= IN6_IFF_NODAD;
567 
568 	/* skip registration to the prefix list. XXX should be temporary. */
569 	ifra.ifra_flags |= IN6_IFF_NOPFX;
570 
571 	/*
572 	 * We are sure that this is a newly assigned address, so we can set
573 	 * NULL to the 3rd arg.
574 	 */
575 	if ((error = in6_update_ifa(ifp, &ifra, NULL, 0)) != 0) {
576 		nd6log((LOG_ERR, "in6_ifattach_loopback: failed to configure "
577 		    "the loopback address on %s (errno=%d)\n",
578 		    if_name(ifp), error));
579 		return (-1);
580 	}
581 
582 	return 0;
583 }
584 
585 /*
586  * compute NI group address, based on the current hostname setting.
587  * see draft-ietf-ipngwg-icmp-name-lookup-* (04 and later).
588  *
589  * when ifp == NULL, the caller is responsible for filling scopeid.
590  */
591 int
592 in6_nigroup(struct ifnet *ifp, const char *name, int namelen,
593     struct in6_addr *in6)
594 {
595 	const char *p;
596 	u_char *q;
597 	MD5_CTX ctxt;
598 	u_int8_t digest[16];
599 	char l;
600 	char n[64];	/* a single label must not exceed 63 chars */
601 
602 	if (!namelen || !name)
603 		return -1;
604 
605 	p = name;
606 	while (p && *p && *p != '.' && p - name < namelen)
607 		p++;
608 	if (p - name > sizeof(n) - 1)
609 		return -1;	/* label too long */
610 	l = p - name;
611 	strncpy(n, name, l);
612 	n[(int)l] = '\0';
613 	for (q = n; *q; q++) {
614 		if ('A' <= *q && *q <= 'Z')
615 			*q = *q - 'A' + 'a';
616 	}
617 
618 	/* generate 8 bytes of pseudo-random value. */
619 	bzero(&ctxt, sizeof(ctxt));
620 	MD5Init(&ctxt);
621 	MD5Update(&ctxt, &l, sizeof(l));
622 	MD5Update(&ctxt, n, l);
623 	MD5Final(digest, &ctxt);
624 
625 	bzero(in6, sizeof(*in6));
626 	in6->s6_addr16[0] = IPV6_ADDR_INT16_MLL;
627 	in6->s6_addr8[11] = 2;
628 	bcopy(digest, &in6->s6_addr32[3], sizeof(in6->s6_addr32[3]));
629 	if (in6_setscope(in6, ifp, NULL))
630 		return (-1); /* XXX: should not fail */
631 
632 	return 0;
633 }
634 
635 /*
636  * XXX multiple loopback interface needs more care.  for instance,
637  * nodelocal address needs to be configured onto only one of them.
638  * XXX multiple link-local address case
639  *
640  * altifp - secondary EUI64 source
641  */
642 void
643 in6_ifattach(struct ifnet *ifp, struct ifnet *altifp)
644 {
645 	struct in6_ifaddr *ia;
646 	struct in6_addr in6;
647 
648 	/* some of the interfaces are inherently not IPv6 capable */
649 	switch (ifp->if_type) {
650 	case IFT_PFLOG:
651 	case IFT_PFSYNC:
652 	case IFT_CARP:
653 		return;
654 	}
655 
656 	/*
657 	 * quirks based on interface type
658 	 */
659 	switch (ifp->if_type) {
660 #ifdef IFT_STF
661 	case IFT_STF:
662 		/*
663 		 * 6to4 interface is a very special kind of beast.
664 		 * no multicast, no linklocal.  RFC2529 specifies how to make
665 		 * linklocals for 6to4 interface, but there's no use and
666 		 * it is rather harmful to have one.
667 		 */
668 		goto statinit;
669 #endif
670 	default:
671 		break;
672 	}
673 
674 	/*
675 	 * usually, we require multicast capability to the interface
676 	 */
677 	if ((ifp->if_flags & IFF_MULTICAST) == 0) {
678 		nd6log((LOG_INFO, "in6_ifattach: "
679 		    "%s is not multicast capable, IPv6 not enabled\n",
680 		    if_name(ifp)));
681 		return;
682 	}
683 
684 	/*
685 	 * assign loopback address for loopback interface.
686 	 * XXX multiple loopback interface case.
687 	 */
688 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
689 		in6 = in6addr_loopback;
690 		if (in6ifa_ifpwithaddr(ifp, &in6) == NULL) {
691 			if (in6_ifattach_loopback(ifp) != 0)
692 				return;
693 		}
694 	}
695 
696 	/*
697 	 * assign a link-local address, if there's none.
698 	 */
699 	if (ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE) {
700 		ia = in6ifa_ifpforlinklocal(ifp, 0);
701 		if (ia == NULL) {
702 			if (in6_ifattach_linklocal(ifp, altifp) == 0) {
703 				/* linklocal address assigned */
704 			} else {
705 				/* failed to assign linklocal address. bark? */
706 			}
707 		}
708 	}
709 
710 #ifdef IFT_STF			/* XXX */
711 statinit:
712 #endif
713 
714 	/* update dynamically. */
715 	if (in6_maxmtu < ifp->if_mtu)
716 		in6_maxmtu = ifp->if_mtu;
717 }
718 
719 /*
720  * NOTE: in6_ifdetach() does not support loopback if at this moment.
721  * We don't need this function in bsdi, because interfaces are never removed
722  * from the ifnet list in bsdi.
723  */
724 void
725 in6_ifdetach(struct ifnet *ifp)
726 {
727 	struct in6_ifaddr *ia, *oia;
728 	struct ifaddr *ifa, *next;
729 	struct rtentry *rt;
730 	short rtflags;
731 	struct sockaddr_in6 sin6;
732 	struct in6_multi_mship *imm;
733 
734 	/* remove neighbor management table */
735 	nd6_purge(ifp);
736 
737 	/* nuke any of IPv6 addresses we have */
738 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = next) {
739 		next = ifa->ifa_list.tqe_next;
740 		if (ifa->ifa_addr->sa_family != AF_INET6)
741 			continue;
742 		in6_purgeaddr(ifa);
743 	}
744 
745 	/* undo everything done by in6_ifattach(), just in case */
746 	for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = next) {
747 		next = ifa->ifa_list.tqe_next;
748 
749 		if (ifa->ifa_addr->sa_family != AF_INET6
750 		 || !IN6_IS_ADDR_LINKLOCAL(&satosin6(&ifa->ifa_addr)->sin6_addr)) {
751 			continue;
752 		}
753 
754 		ia = (struct in6_ifaddr *)ifa;
755 
756 		/*
757 		 * leave from multicast groups we have joined for the interface
758 		 */
759 		while ((imm = ia->ia6_memberships.lh_first) != NULL) {
760 			LIST_REMOVE(imm, i6mm_chain);
761 			in6_leavegroup(imm);
762 		}
763 
764 		/* remove from the routing table */
765 		if ((ia->ia_flags & IFA_ROUTE) &&
766 		    (rt = rtalloc1((struct sockaddr *)&ia->ia_addr, 0, 0UL))) {
767 			rtflags = rt->rt_flags;
768 			rtfree(rt);
769 			rtrequest(RTM_DELETE, (struct sockaddr *)&ia->ia_addr,
770 			    (struct sockaddr *)&ia->ia_addr,
771 			    (struct sockaddr *)&ia->ia_prefixmask,
772 			    rtflags, (struct rtentry **)0);
773 		}
774 
775 		/* remove from the linked list */
776 		TAILQ_REMOVE(&ifp->if_addrlist, (struct ifaddr *)ia, ifa_list);
777 		IFAFREE(&ia->ia_ifa);
778 
779 		/* also remove from the IPv6 address chain(itojun&jinmei) */
780 		oia = ia;
781 		if (oia == (ia = in6_ifaddr))
782 			in6_ifaddr = ia->ia_next;
783 		else {
784 			while (ia->ia_next && (ia->ia_next != oia))
785 				ia = ia->ia_next;
786 			if (ia->ia_next)
787 				ia->ia_next = oia->ia_next;
788 			else {
789 				nd6log((LOG_ERR,
790 				    "%s: didn't unlink in6ifaddr from list\n",
791 				    if_name(ifp)));
792 			}
793 		}
794 
795 		IFAFREE(&oia->ia_ifa);
796 	}
797 
798 	in6_pcbpurgeif0(&udbinfo, ifp);
799 	in6_pcbpurgeif0(&ripcbinfo, ifp);
800 	/* leave from all multicast groups joined */
801 	in6_purgemaddrs(ifp);
802 
803 	/*
804 	 * remove neighbor management table.  we call it twice just to make
805 	 * sure we nuke everything.  maybe we need just one call.
806 	 * XXX: since the first call did not release addresses, some prefixes
807 	 * might remain.  We should call nd6_purge() again to release the
808 	 * prefixes after removing all addresses above.
809 	 * (Or can we just delay calling nd6_purge until at this point?)
810 	 */
811 	nd6_purge(ifp);
812 
813 	/* remove route to link-local allnodes multicast (ff02::1) */
814 	bzero(&sin6, sizeof(sin6));
815 	sin6.sin6_len = sizeof(struct sockaddr_in6);
816 	sin6.sin6_family = AF_INET6;
817 	sin6.sin6_addr = in6addr_linklocal_allnodes;
818 	if (in6_setscope(&sin6.sin6_addr, ifp, NULL))
819 		/* XXX: should not fail */
820 		return;
821 	/* XXX grab lock first to avoid LOR */
822 	if (rt_tables[AF_INET6] != NULL) {
823 		RADIX_NODE_HEAD_LOCK(rt_tables[AF_INET6]);
824 		rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
825 		if (rt) {
826 			if (rt->rt_ifp == ifp)
827 				rtexpunge(rt);
828 			RTFREE_LOCKED(rt);
829 		}
830 		RADIX_NODE_HEAD_UNLOCK(rt_tables[AF_INET6]);
831 	}
832 }
833 
834 int
835 in6_get_tmpifid(struct ifnet *ifp, u_int8_t *retbuf,
836     const u_int8_t *baseid, int generate)
837 {
838 	u_int8_t nullbuf[8];
839 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
840 
841 	bzero(nullbuf, sizeof(nullbuf));
842 	if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
843 		/* we've never created a random ID.  Create a new one. */
844 		generate = 1;
845 	}
846 
847 	if (generate) {
848 		bcopy(baseid, ndi->randomseed1, sizeof(ndi->randomseed1));
849 
850 		/* generate_tmp_ifid will update seedn and buf */
851 		(void)generate_tmp_ifid(ndi->randomseed0, ndi->randomseed1,
852 		    ndi->randomid);
853 	}
854 	bcopy(ndi->randomid, retbuf, 8);
855 
856 	return (0);
857 }
858 
859 void
860 in6_tmpaddrtimer(void *ignored_arg)
861 {
862 	struct nd_ifinfo *ndi;
863 	u_int8_t nullbuf[8];
864 	struct ifnet *ifp;
865 	int s = splnet();
866 
867 	callout_reset(&in6_tmpaddrtimer_ch,
868 	    (ip6_temp_preferred_lifetime - ip6_desync_factor -
869 	    ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, NULL);
870 
871 	bzero(nullbuf, sizeof(nullbuf));
872 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
873 		ndi = ND_IFINFO(ifp);
874 		if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
875 			/*
876 			 * We've been generating a random ID on this interface.
877 			 * Create a new one.
878 			 */
879 			(void)generate_tmp_ifid(ndi->randomseed0,
880 			    ndi->randomseed1, ndi->randomid);
881 		}
882 	}
883 
884 	splx(s);
885 }
886 
887 static void
888 in6_purgemaddrs(struct ifnet *ifp)
889 {
890 	struct in6_multi *in6m;
891 	struct in6_multi *oin6m;
892 
893 #ifdef DIAGNOSTIC
894 	printf("%s: purging ifp %p\n", __func__, ifp);
895 #endif
896 
897 	IFF_LOCKGIANT(ifp);
898 	LIST_FOREACH_SAFE(in6m, &in6_multihead, in6m_entry, oin6m) {
899 		if (in6m->in6m_ifp == ifp)
900 			in6_delmulti(in6m);
901 	}
902 	IFF_UNLOCKGIANT(ifp);
903 }
904