xref: /freebsd/sys/netinet6/in6_ifattach.c (revision 287472b39c7985d968be84ea145c3e75a3e6b875)
1 /*-
2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the project nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	$KAME: in6_ifattach.c,v 1.118 2001/05/24 07:44:00 itojun Exp $
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/malloc.h>
38 #include <sys/socket.h>
39 #include <sys/sockio.h>
40 #include <sys/jail.h>
41 #include <sys/kernel.h>
42 #include <sys/proc.h>
43 #include <sys/syslog.h>
44 #include <sys/md5.h>
45 
46 #include <net/if.h>
47 #include <net/if_dl.h>
48 #include <net/if_types.h>
49 #include <net/route.h>
50 #include <net/vnet.h>
51 
52 #include <netinet/in.h>
53 #include <netinet/in_var.h>
54 #include <netinet/if_ether.h>
55 #include <netinet/in_pcb.h>
56 #include <netinet/ip_var.h>
57 #include <netinet/udp.h>
58 #include <netinet/udp_var.h>
59 
60 #include <netinet/ip6.h>
61 #include <netinet6/ip6_var.h>
62 #include <netinet6/in6_var.h>
63 #include <netinet6/in6_pcb.h>
64 #include <netinet6/in6_ifattach.h>
65 #include <netinet6/ip6_var.h>
66 #include <netinet6/nd6.h>
67 #include <netinet6/mld6_var.h>
68 #include <netinet6/scope6_var.h>
69 
70 VNET_DEFINE(unsigned long, in6_maxmtu) = 0;
71 
72 #ifdef IP6_AUTO_LINKLOCAL
73 VNET_DEFINE(int, ip6_auto_linklocal) = IP6_AUTO_LINKLOCAL;
74 #else
75 VNET_DEFINE(int, ip6_auto_linklocal) = 1;	/* enabled by default */
76 #endif
77 
78 VNET_DEFINE(struct callout, in6_tmpaddrtimer_ch);
79 #define	V_in6_tmpaddrtimer_ch		VNET(in6_tmpaddrtimer_ch)
80 
81 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
82 #define	V_ripcbinfo			VNET(ripcbinfo)
83 
84 static int get_rand_ifid(struct ifnet *, struct in6_addr *);
85 static int generate_tmp_ifid(u_int8_t *, const u_int8_t *, u_int8_t *);
86 static int get_ifid(struct ifnet *, struct ifnet *, struct in6_addr *);
87 static int in6_ifattach_linklocal(struct ifnet *, struct ifnet *);
88 static int in6_ifattach_loopback(struct ifnet *);
89 static void in6_purgemaddrs(struct ifnet *);
90 
91 #define EUI64_GBIT	0x01
92 #define EUI64_UBIT	0x02
93 #define EUI64_TO_IFID(in6)	do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (0)
94 #define EUI64_GROUP(in6)	((in6)->s6_addr[8] & EUI64_GBIT)
95 #define EUI64_INDIVIDUAL(in6)	(!EUI64_GROUP(in6))
96 #define EUI64_LOCAL(in6)	((in6)->s6_addr[8] & EUI64_UBIT)
97 #define EUI64_UNIVERSAL(in6)	(!EUI64_LOCAL(in6))
98 
99 #define IFID_LOCAL(in6)		(!EUI64_LOCAL(in6))
100 #define IFID_UNIVERSAL(in6)	(!EUI64_UNIVERSAL(in6))
101 
102 /*
103  * Generate a last-resort interface identifier, when the machine has no
104  * IEEE802/EUI64 address sources.
105  * The goal here is to get an interface identifier that is
106  * (1) random enough and (2) does not change across reboot.
107  * We currently use MD5(hostname) for it.
108  *
109  * in6 - upper 64bits are preserved
110  */
111 static int
112 get_rand_ifid(struct ifnet *ifp, struct in6_addr *in6)
113 {
114 	MD5_CTX ctxt;
115 	struct prison *pr;
116 	u_int8_t digest[16];
117 	int hostnamelen;
118 
119 	pr = curthread->td_ucred->cr_prison;
120 	mtx_lock(&pr->pr_mtx);
121 	hostnamelen = strlen(pr->pr_hostname);
122 #if 0
123 	/* we need at least several letters as seed for ifid */
124 	if (hostnamelen < 3) {
125 		mtx_unlock(&pr->pr_mtx);
126 		return -1;
127 	}
128 #endif
129 
130 	/* generate 8 bytes of pseudo-random value. */
131 	bzero(&ctxt, sizeof(ctxt));
132 	MD5Init(&ctxt);
133 	MD5Update(&ctxt, pr->pr_hostname, hostnamelen);
134 	mtx_unlock(&pr->pr_mtx);
135 	MD5Final(digest, &ctxt);
136 
137 	/* assumes sizeof(digest) > sizeof(ifid) */
138 	bcopy(digest, &in6->s6_addr[8], 8);
139 
140 	/* make sure to set "u" bit to local, and "g" bit to individual. */
141 	in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
142 	in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
143 
144 	/* convert EUI64 into IPv6 interface identifier */
145 	EUI64_TO_IFID(in6);
146 
147 	return 0;
148 }
149 
150 static int
151 generate_tmp_ifid(u_int8_t *seed0, const u_int8_t *seed1, u_int8_t *ret)
152 {
153 	MD5_CTX ctxt;
154 	u_int8_t seed[16], digest[16], nullbuf[8];
155 	u_int32_t val32;
156 
157 	/* If there's no history, start with a random seed. */
158 	bzero(nullbuf, sizeof(nullbuf));
159 	if (bcmp(nullbuf, seed0, sizeof(nullbuf)) == 0) {
160 		int i;
161 
162 		for (i = 0; i < 2; i++) {
163 			val32 = arc4random();
164 			bcopy(&val32, seed + sizeof(val32) * i, sizeof(val32));
165 		}
166 	} else
167 		bcopy(seed0, seed, 8);
168 
169 	/* copy the right-most 64-bits of the given address */
170 	/* XXX assumption on the size of IFID */
171 	bcopy(seed1, &seed[8], 8);
172 
173 	if (0) {		/* for debugging purposes only */
174 		int i;
175 
176 		printf("generate_tmp_ifid: new randomized ID from: ");
177 		for (i = 0; i < 16; i++)
178 			printf("%02x", seed[i]);
179 		printf(" ");
180 	}
181 
182 	/* generate 16 bytes of pseudo-random value. */
183 	bzero(&ctxt, sizeof(ctxt));
184 	MD5Init(&ctxt);
185 	MD5Update(&ctxt, seed, sizeof(seed));
186 	MD5Final(digest, &ctxt);
187 
188 	/*
189 	 * RFC 3041 3.2.1. (3)
190 	 * Take the left-most 64-bits of the MD5 digest and set bit 6 (the
191 	 * left-most bit is numbered 0) to zero.
192 	 */
193 	bcopy(digest, ret, 8);
194 	ret[0] &= ~EUI64_UBIT;
195 
196 	/*
197 	 * XXX: we'd like to ensure that the generated value is not zero
198 	 * for simplicity.  If the caclculated digest happens to be zero,
199 	 * use a random non-zero value as the last resort.
200 	 */
201 	if (bcmp(nullbuf, ret, sizeof(nullbuf)) == 0) {
202 		nd6log((LOG_INFO,
203 		    "generate_tmp_ifid: computed MD5 value is zero.\n"));
204 
205 		val32 = arc4random();
206 		val32 = 1 + (val32 % (0xffffffff - 1));
207 	}
208 
209 	/*
210 	 * RFC 3041 3.2.1. (4)
211 	 * Take the rightmost 64-bits of the MD5 digest and save them in
212 	 * stable storage as the history value to be used in the next
213 	 * iteration of the algorithm.
214 	 */
215 	bcopy(&digest[8], seed0, 8);
216 
217 	if (0) {		/* for debugging purposes only */
218 		int i;
219 
220 		printf("to: ");
221 		for (i = 0; i < 16; i++)
222 			printf("%02x", digest[i]);
223 		printf("\n");
224 	}
225 
226 	return 0;
227 }
228 
229 /*
230  * Get interface identifier for the specified interface.
231  * XXX assumes single sockaddr_dl (AF_LINK address) per an interface
232  *
233  * in6 - upper 64bits are preserved
234  */
235 int
236 in6_get_hw_ifid(struct ifnet *ifp, struct in6_addr *in6)
237 {
238 	struct ifaddr *ifa;
239 	struct sockaddr_dl *sdl;
240 	u_int8_t *addr;
241 	size_t addrlen;
242 	static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
243 	static u_int8_t allone[8] =
244 		{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
245 
246 	IF_ADDR_RLOCK(ifp);
247 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
248 		if (ifa->ifa_addr->sa_family != AF_LINK)
249 			continue;
250 		sdl = (struct sockaddr_dl *)ifa->ifa_addr;
251 		if (sdl == NULL)
252 			continue;
253 		if (sdl->sdl_alen == 0)
254 			continue;
255 
256 		goto found;
257 	}
258 	IF_ADDR_RUNLOCK(ifp);
259 
260 	return -1;
261 
262 found:
263 	IF_ADDR_LOCK_ASSERT(ifp);
264 	addr = LLADDR(sdl);
265 	addrlen = sdl->sdl_alen;
266 
267 	/* get EUI64 */
268 	switch (ifp->if_type) {
269 	case IFT_BRIDGE:
270 	case IFT_ETHER:
271 	case IFT_L2VLAN:
272 	case IFT_FDDI:
273 	case IFT_ISO88025:
274 	case IFT_ATM:
275 	case IFT_IEEE1394:
276 #ifdef IFT_IEEE80211
277 	case IFT_IEEE80211:
278 #endif
279 		/* IEEE802/EUI64 cases - what others? */
280 		/* IEEE1394 uses 16byte length address starting with EUI64 */
281 		if (addrlen > 8)
282 			addrlen = 8;
283 
284 		/* look at IEEE802/EUI64 only */
285 		if (addrlen != 8 && addrlen != 6) {
286 			IF_ADDR_RUNLOCK(ifp);
287 			return -1;
288 		}
289 
290 		/*
291 		 * check for invalid MAC address - on bsdi, we see it a lot
292 		 * since wildboar configures all-zero MAC on pccard before
293 		 * card insertion.
294 		 */
295 		if (bcmp(addr, allzero, addrlen) == 0) {
296 			IF_ADDR_RUNLOCK(ifp);
297 			return -1;
298 		}
299 		if (bcmp(addr, allone, addrlen) == 0) {
300 			IF_ADDR_RUNLOCK(ifp);
301 			return -1;
302 		}
303 
304 		/* make EUI64 address */
305 		if (addrlen == 8)
306 			bcopy(addr, &in6->s6_addr[8], 8);
307 		else if (addrlen == 6) {
308 			in6->s6_addr[8] = addr[0];
309 			in6->s6_addr[9] = addr[1];
310 			in6->s6_addr[10] = addr[2];
311 			in6->s6_addr[11] = 0xff;
312 			in6->s6_addr[12] = 0xfe;
313 			in6->s6_addr[13] = addr[3];
314 			in6->s6_addr[14] = addr[4];
315 			in6->s6_addr[15] = addr[5];
316 		}
317 		break;
318 
319 	case IFT_ARCNET:
320 		if (addrlen != 1) {
321 			IF_ADDR_RUNLOCK(ifp);
322 			return -1;
323 		}
324 		if (!addr[0]) {
325 			IF_ADDR_RUNLOCK(ifp);
326 			return -1;
327 		}
328 
329 		bzero(&in6->s6_addr[8], 8);
330 		in6->s6_addr[15] = addr[0];
331 
332 		/*
333 		 * due to insufficient bitwidth, we mark it local.
334 		 */
335 		in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
336 		in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
337 		break;
338 
339 	case IFT_GIF:
340 #ifdef IFT_STF
341 	case IFT_STF:
342 #endif
343 		/*
344 		 * RFC2893 says: "SHOULD use IPv4 address as ifid source".
345 		 * however, IPv4 address is not very suitable as unique
346 		 * identifier source (can be renumbered).
347 		 * we don't do this.
348 		 */
349 		IF_ADDR_RUNLOCK(ifp);
350 		return -1;
351 
352 	default:
353 		IF_ADDR_RUNLOCK(ifp);
354 		return -1;
355 	}
356 
357 	/* sanity check: g bit must not indicate "group" */
358 	if (EUI64_GROUP(in6)) {
359 		IF_ADDR_RUNLOCK(ifp);
360 		return -1;
361 	}
362 
363 	/* convert EUI64 into IPv6 interface identifier */
364 	EUI64_TO_IFID(in6);
365 
366 	/*
367 	 * sanity check: ifid must not be all zero, avoid conflict with
368 	 * subnet router anycast
369 	 */
370 	if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
371 	    bcmp(&in6->s6_addr[9], allzero, 7) == 0) {
372 		IF_ADDR_RUNLOCK(ifp);
373 		return -1;
374 	}
375 
376 	IF_ADDR_RUNLOCK(ifp);
377 	return 0;
378 }
379 
380 /*
381  * Get interface identifier for the specified interface.  If it is not
382  * available on ifp0, borrow interface identifier from other information
383  * sources.
384  *
385  * altifp - secondary EUI64 source
386  */
387 static int
388 get_ifid(struct ifnet *ifp0, struct ifnet *altifp,
389     struct in6_addr *in6)
390 {
391 	struct ifnet *ifp;
392 
393 	/* first, try to get it from the interface itself */
394 	if (in6_get_hw_ifid(ifp0, in6) == 0) {
395 		nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n",
396 		    if_name(ifp0)));
397 		goto success;
398 	}
399 
400 	/* try secondary EUI64 source. this basically is for ATM PVC */
401 	if (altifp && in6_get_hw_ifid(altifp, in6) == 0) {
402 		nd6log((LOG_DEBUG, "%s: got interface identifier from %s\n",
403 		    if_name(ifp0), if_name(altifp)));
404 		goto success;
405 	}
406 
407 	/* next, try to get it from some other hardware interface */
408 	IFNET_RLOCK_NOSLEEP();
409 	TAILQ_FOREACH(ifp, &V_ifnet, if_list) {
410 		if (ifp == ifp0)
411 			continue;
412 		if (in6_get_hw_ifid(ifp, in6) != 0)
413 			continue;
414 
415 		/*
416 		 * to borrow ifid from other interface, ifid needs to be
417 		 * globally unique
418 		 */
419 		if (IFID_UNIVERSAL(in6)) {
420 			nd6log((LOG_DEBUG,
421 			    "%s: borrow interface identifier from %s\n",
422 			    if_name(ifp0), if_name(ifp)));
423 			IFNET_RUNLOCK_NOSLEEP();
424 			goto success;
425 		}
426 	}
427 	IFNET_RUNLOCK_NOSLEEP();
428 
429 	/* last resort: get from random number source */
430 	if (get_rand_ifid(ifp, in6) == 0) {
431 		nd6log((LOG_DEBUG,
432 		    "%s: interface identifier generated by random number\n",
433 		    if_name(ifp0)));
434 		goto success;
435 	}
436 
437 	printf("%s: failed to get interface identifier\n", if_name(ifp0));
438 	return -1;
439 
440 success:
441 	nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
442 	    if_name(ifp0), in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10],
443 	    in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13],
444 	    in6->s6_addr[14], in6->s6_addr[15]));
445 	return 0;
446 }
447 
448 /*
449  * altifp - secondary EUI64 source
450  */
451 static int
452 in6_ifattach_linklocal(struct ifnet *ifp, struct ifnet *altifp)
453 {
454 	struct in6_ifaddr *ia;
455 	struct in6_aliasreq ifra;
456 	struct nd_prefixctl pr0;
457 	int i, error;
458 
459 	/*
460 	 * configure link-local address.
461 	 */
462 	bzero(&ifra, sizeof(ifra));
463 
464 	/*
465 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
466 	 * for safety.
467 	 */
468 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
469 
470 	ifra.ifra_addr.sin6_family = AF_INET6;
471 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
472 	ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000);
473 	ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
474 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
475 		ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
476 		ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
477 	} else {
478 		if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) {
479 			nd6log((LOG_ERR,
480 			    "%s: no ifid available\n", if_name(ifp)));
481 			return (-1);
482 		}
483 	}
484 	if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL))
485 		return (-1);
486 
487 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
488 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
489 	ifra.ifra_prefixmask.sin6_addr = in6mask64;
490 	/* link-local addresses should NEVER expire. */
491 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
492 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
493 
494 	/*
495 	 * Now call in6_update_ifa() to do a bunch of procedures to configure
496 	 * a link-local address. We can set the 3rd argument to NULL, because
497 	 * we know there's no other link-local address on the interface
498 	 * and therefore we are adding one (instead of updating one).
499 	 */
500 	if ((error = in6_update_ifa(ifp, &ifra, NULL,
501 				    IN6_IFAUPDATE_DADDELAY)) != 0) {
502 		/*
503 		 * XXX: When the interface does not support IPv6, this call
504 		 * would fail in the SIOCSIFADDR ioctl.  I believe the
505 		 * notification is rather confusing in this case, so just
506 		 * suppress it.  (jinmei@kame.net 20010130)
507 		 */
508 		if (error != EAFNOSUPPORT)
509 			nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to "
510 			    "configure a link-local address on %s "
511 			    "(errno=%d)\n",
512 			    if_name(ifp), error));
513 		return (-1);
514 	}
515 
516 	ia = in6ifa_ifpforlinklocal(ifp, 0); /* ia must not be NULL */
517 	KASSERT(ia != NULL, ("%s: ia == NULL, ifp=%p", __func__, ifp));
518 
519 	ifa_free(&ia->ia_ifa);
520 
521 	/*
522 	 * Make the link-local prefix (fe80::%link/64) as on-link.
523 	 * Since we'd like to manage prefixes separately from addresses,
524 	 * we make an ND6 prefix structure for the link-local prefix,
525 	 * and add it to the prefix list as a never-expire prefix.
526 	 * XXX: this change might affect some existing code base...
527 	 */
528 	bzero(&pr0, sizeof(pr0));
529 	pr0.ndpr_ifp = ifp;
530 	/* this should be 64 at this moment. */
531 	pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
532 	pr0.ndpr_prefix = ifra.ifra_addr;
533 	/* apply the mask for safety. (nd6_prelist_add will apply it again) */
534 	for (i = 0; i < 4; i++) {
535 		pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
536 		    in6mask64.s6_addr32[i];
537 	}
538 	/*
539 	 * Initialize parameters.  The link-local prefix must always be
540 	 * on-link, and its lifetimes never expire.
541 	 */
542 	pr0.ndpr_raf_onlink = 1;
543 	pr0.ndpr_raf_auto = 1;	/* probably meaningless */
544 	pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
545 	pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
546 	/*
547 	 * Since there is no other link-local addresses, nd6_prefix_lookup()
548 	 * probably returns NULL.  However, we cannot always expect the result.
549 	 * For example, if we first remove the (only) existing link-local
550 	 * address, and then reconfigure another one, the prefix is still
551 	 * valid with referring to the old link-local address.
552 	 */
553 	if (nd6_prefix_lookup(&pr0) == NULL) {
554 		if ((error = nd6_prelist_add(&pr0, NULL, NULL)) != 0)
555 			return (error);
556 	}
557 
558 	return 0;
559 }
560 
561 /*
562  * ifp - must be IFT_LOOP
563  */
564 static int
565 in6_ifattach_loopback(struct ifnet *ifp)
566 {
567 	struct in6_aliasreq ifra;
568 	int error;
569 
570 	bzero(&ifra, sizeof(ifra));
571 
572 	/*
573 	 * in6_update_ifa() does not use ifra_name, but we accurately set it
574 	 * for safety.
575 	 */
576 	strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
577 
578 	ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
579 	ifra.ifra_prefixmask.sin6_family = AF_INET6;
580 	ifra.ifra_prefixmask.sin6_addr = in6mask128;
581 
582 	/*
583 	 * Always initialize ia_dstaddr (= broadcast address) to loopback
584 	 * address.  Follows IPv4 practice - see in_ifinit().
585 	 */
586 	ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
587 	ifra.ifra_dstaddr.sin6_family = AF_INET6;
588 	ifra.ifra_dstaddr.sin6_addr = in6addr_loopback;
589 
590 	ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
591 	ifra.ifra_addr.sin6_family = AF_INET6;
592 	ifra.ifra_addr.sin6_addr = in6addr_loopback;
593 
594 	/* the loopback  address should NEVER expire. */
595 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
596 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
597 
598 	/* we don't need to perform DAD on loopback interfaces. */
599 	ifra.ifra_flags |= IN6_IFF_NODAD;
600 
601 	/* skip registration to the prefix list. XXX should be temporary. */
602 	ifra.ifra_flags |= IN6_IFF_NOPFX;
603 
604 	/*
605 	 * We are sure that this is a newly assigned address, so we can set
606 	 * NULL to the 3rd arg.
607 	 */
608 	if ((error = in6_update_ifa(ifp, &ifra, NULL, 0)) != 0) {
609 		nd6log((LOG_ERR, "in6_ifattach_loopback: failed to configure "
610 		    "the loopback address on %s (errno=%d)\n",
611 		    if_name(ifp), error));
612 		return (-1);
613 	}
614 
615 	return 0;
616 }
617 
618 /*
619  * compute NI group address, based on the current hostname setting.
620  * see RFC 4620.
621  *
622  * when ifp == NULL, the caller is responsible for filling scopeid.
623  *
624  * If oldmcprefix == 1, FF02:0:0:0:0:2::/96 is used for NI group address
625  * while it is FF02:0:0:0:0:2:FF00::/104 in RFC 4620.
626  */
627 static int
628 in6_nigroup0(struct ifnet *ifp, const char *name, int namelen,
629     struct in6_addr *in6, int oldmcprefix)
630 {
631 	struct prison *pr;
632 	const char *p;
633 	u_char *q;
634 	MD5_CTX ctxt;
635 	u_int8_t digest[16];
636 	char l;
637 	char n[64];	/* a single label must not exceed 63 chars */
638 
639 	/*
640 	 * If no name is given and namelen is -1,
641 	 * we try to do the hostname lookup ourselves.
642 	 */
643 	if (!name && namelen == -1) {
644 		pr = curthread->td_ucred->cr_prison;
645 		mtx_lock(&pr->pr_mtx);
646 		name = pr->pr_hostname;
647 		namelen = strlen(name);
648 	} else
649 		pr = NULL;
650 	if (!name || !namelen) {
651 		if (pr != NULL)
652 			mtx_unlock(&pr->pr_mtx);
653 		return -1;
654 	}
655 
656 	p = name;
657 	while (p && *p && *p != '.' && p - name < namelen)
658 		p++;
659 	if (p == name || p - name > sizeof(n) - 1) {
660 		if (pr != NULL)
661 			mtx_unlock(&pr->pr_mtx);
662 		return -1;	/* label too long */
663 	}
664 	l = p - name;
665 	strncpy(n, name, l);
666 	if (pr != NULL)
667 		mtx_unlock(&pr->pr_mtx);
668 	n[(int)l] = '\0';
669 	for (q = n; *q; q++) {
670 		if ('A' <= *q && *q <= 'Z')
671 			*q = *q - 'A' + 'a';
672 	}
673 
674 	/* generate 16 bytes of pseudo-random value. */
675 	bzero(&ctxt, sizeof(ctxt));
676 	MD5Init(&ctxt);
677 	MD5Update(&ctxt, &l, sizeof(l));
678 	MD5Update(&ctxt, n, l);
679 	MD5Final(digest, &ctxt);
680 
681 	bzero(in6, sizeof(*in6));
682 	in6->s6_addr16[0] = IPV6_ADDR_INT16_MLL;
683 	in6->s6_addr8[11] = 2;
684 	if (oldmcprefix == 0) {
685 		in6->s6_addr8[12] = 0xff;
686 	 	/* Copy the first 24 bits of 128-bit hash into the address. */
687 		bcopy(digest, &in6->s6_addr8[13], 3);
688 	} else {
689 	 	/* Copy the first 32 bits of 128-bit hash into the address. */
690 		bcopy(digest, &in6->s6_addr32[3], sizeof(in6->s6_addr32[3]));
691 	}
692 	if (in6_setscope(in6, ifp, NULL))
693 		return (-1); /* XXX: should not fail */
694 
695 	return 0;
696 }
697 
698 int
699 in6_nigroup(struct ifnet *ifp, const char *name, int namelen,
700     struct in6_addr *in6)
701 {
702 
703 	return (in6_nigroup0(ifp, name, namelen, in6, 0));
704 }
705 
706 int
707 in6_nigroup_oldmcprefix(struct ifnet *ifp, const char *name, int namelen,
708     struct in6_addr *in6)
709 {
710 
711 	return (in6_nigroup0(ifp, name, namelen, in6, 1));
712 }
713 
714 /*
715  * XXX multiple loopback interface needs more care.  for instance,
716  * nodelocal address needs to be configured onto only one of them.
717  * XXX multiple link-local address case
718  *
719  * altifp - secondary EUI64 source
720  */
721 void
722 in6_ifattach(struct ifnet *ifp, struct ifnet *altifp)
723 {
724 	struct in6_ifaddr *ia;
725 	struct in6_addr in6;
726 
727 	if (ifp->if_afdata[AF_INET6] == NULL)
728 		return;
729 	/*
730 	 * quirks based on interface type
731 	 */
732 	switch (ifp->if_type) {
733 	case IFT_STF:
734 		/*
735 		 * 6to4 interface is a very special kind of beast.
736 		 * no multicast, no linklocal.  RFC2529 specifies how to make
737 		 * linklocals for 6to4 interface, but there's no use and
738 		 * it is rather harmful to have one.
739 		 */
740 		ND_IFINFO(ifp)->flags &= ~ND6_IFF_AUTO_LINKLOCAL;
741 		break;
742 	default:
743 		break;
744 	}
745 
746 	/*
747 	 * usually, we require multicast capability to the interface
748 	 */
749 	if ((ifp->if_flags & IFF_MULTICAST) == 0) {
750 		nd6log((LOG_INFO, "in6_ifattach: "
751 		    "%s is not multicast capable, IPv6 not enabled\n",
752 		    if_name(ifp)));
753 		return;
754 	}
755 
756 	/*
757 	 * assign loopback address for loopback interface.
758 	 * XXX multiple loopback interface case.
759 	 */
760 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
761 		struct ifaddr *ifa;
762 
763 		in6 = in6addr_loopback;
764 		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &in6);
765 		if (ifa == NULL) {
766 			if (in6_ifattach_loopback(ifp) != 0)
767 				return;
768 		} else
769 			ifa_free(ifa);
770 	}
771 
772 	/*
773 	 * assign a link-local address, if there's none.
774 	 */
775 	if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
776 	    ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL) {
777 		int error;
778 
779 		ia = in6ifa_ifpforlinklocal(ifp, 0);
780 		if (ia == NULL) {
781 			error = in6_ifattach_linklocal(ifp, altifp);
782 #if 0
783 			if (error)
784 				log(LOG_NOTICE, "in6_ifattach_linklocal: "
785 				    "failed to add a link-local addr to %s\n",
786 				    if_name(ifp));
787 #endif
788 		} else
789 			ifa_free(&ia->ia_ifa);
790 	}
791 
792 	/* update dynamically. */
793 	if (V_in6_maxmtu < ifp->if_mtu)
794 		V_in6_maxmtu = ifp->if_mtu;
795 }
796 
797 /*
798  * NOTE: in6_ifdetach() does not support loopback if at this moment.
799  * We don't need this function in bsdi, because interfaces are never removed
800  * from the ifnet list in bsdi.
801  */
802 void
803 in6_ifdetach(struct ifnet *ifp)
804 {
805 	struct in6_ifaddr *ia;
806 	struct ifaddr *ifa, *next;
807 	struct radix_node_head *rnh;
808 	struct rtentry *rt;
809 	struct sockaddr_in6 sin6;
810 	struct in6_multi_mship *imm;
811 
812 	/* remove neighbor management table */
813 	nd6_purge(ifp);
814 
815 	/* nuke any of IPv6 addresses we have */
816 	TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
817 		if (ifa->ifa_addr->sa_family != AF_INET6)
818 			continue;
819 		in6_purgeaddr(ifa);
820 	}
821 
822 	/* undo everything done by in6_ifattach(), just in case */
823 	TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
824 		if (ifa->ifa_addr->sa_family != AF_INET6
825 		 || !IN6_IS_ADDR_LINKLOCAL(&satosin6(&ifa->ifa_addr)->sin6_addr)) {
826 			continue;
827 		}
828 
829 		ia = (struct in6_ifaddr *)ifa;
830 
831 		/*
832 		 * leave from multicast groups we have joined for the interface
833 		 */
834 		while ((imm = LIST_FIRST(&ia->ia6_memberships)) != NULL) {
835 			LIST_REMOVE(imm, i6mm_chain);
836 			in6_leavegroup(imm);
837 		}
838 
839 		/* Remove link-local from the routing table. */
840 		if (ia->ia_flags & IFA_ROUTE)
841 			(void)rtinit(&ia->ia_ifa, RTM_DELETE, ia->ia_flags);
842 
843 		/* remove from the linked list */
844 		IF_ADDR_WLOCK(ifp);
845 		TAILQ_REMOVE(&ifp->if_addrhead, ifa, ifa_link);
846 		IF_ADDR_WUNLOCK(ifp);
847 		ifa_free(ifa);				/* if_addrhead */
848 
849 		IN6_IFADDR_WLOCK();
850 		TAILQ_REMOVE(&V_in6_ifaddrhead, ia, ia_link);
851 		IN6_IFADDR_WUNLOCK();
852 		ifa_free(ifa);
853 	}
854 
855 	in6_pcbpurgeif0(&V_udbinfo, ifp);
856 	in6_pcbpurgeif0(&V_ripcbinfo, ifp);
857 	/* leave from all multicast groups joined */
858 	in6_purgemaddrs(ifp);
859 
860 	/*
861 	 * remove neighbor management table.  we call it twice just to make
862 	 * sure we nuke everything.  maybe we need just one call.
863 	 * XXX: since the first call did not release addresses, some prefixes
864 	 * might remain.  We should call nd6_purge() again to release the
865 	 * prefixes after removing all addresses above.
866 	 * (Or can we just delay calling nd6_purge until at this point?)
867 	 */
868 	nd6_purge(ifp);
869 
870 	/*
871 	 * Remove route to link-local allnodes multicast (ff02::1).
872 	 * These only get automatically installed for the default FIB.
873 	 */
874 	bzero(&sin6, sizeof(sin6));
875 	sin6.sin6_len = sizeof(struct sockaddr_in6);
876 	sin6.sin6_family = AF_INET6;
877 	sin6.sin6_addr = in6addr_linklocal_allnodes;
878 	if (in6_setscope(&sin6.sin6_addr, ifp, NULL))
879 		/* XXX: should not fail */
880 		return;
881 	/* XXX grab lock first to avoid LOR */
882 	rnh = rt_tables_get_rnh(RT_DEFAULT_FIB, AF_INET6);
883 	if (rnh != NULL) {
884 		RADIX_NODE_HEAD_LOCK(rnh);
885 		rt = in6_rtalloc1((struct sockaddr *)&sin6, 0, RTF_RNH_LOCKED,
886 		    RT_DEFAULT_FIB);
887 		if (rt) {
888 			if (rt->rt_ifp == ifp)
889 				rtexpunge(rt);
890 			RTFREE_LOCKED(rt);
891 		}
892 		RADIX_NODE_HEAD_UNLOCK(rnh);
893 	}
894 }
895 
896 int
897 in6_get_tmpifid(struct ifnet *ifp, u_int8_t *retbuf,
898     const u_int8_t *baseid, int generate)
899 {
900 	u_int8_t nullbuf[8];
901 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
902 
903 	bzero(nullbuf, sizeof(nullbuf));
904 	if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
905 		/* we've never created a random ID.  Create a new one. */
906 		generate = 1;
907 	}
908 
909 	if (generate) {
910 		bcopy(baseid, ndi->randomseed1, sizeof(ndi->randomseed1));
911 
912 		/* generate_tmp_ifid will update seedn and buf */
913 		(void)generate_tmp_ifid(ndi->randomseed0, ndi->randomseed1,
914 		    ndi->randomid);
915 	}
916 	bcopy(ndi->randomid, retbuf, 8);
917 
918 	return (0);
919 }
920 
921 void
922 in6_tmpaddrtimer(void *arg)
923 {
924 	CURVNET_SET((struct vnet *) arg);
925 	struct nd_ifinfo *ndi;
926 	u_int8_t nullbuf[8];
927 	struct ifnet *ifp;
928 
929 	callout_reset(&V_in6_tmpaddrtimer_ch,
930 	    (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
931 	    V_ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, curvnet);
932 
933 	bzero(nullbuf, sizeof(nullbuf));
934 	TAILQ_FOREACH(ifp, &V_ifnet, if_list) {
935 		if (ifp->if_afdata[AF_INET6] == NULL)
936 			continue;
937 		ndi = ND_IFINFO(ifp);
938 		if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
939 			/*
940 			 * We've been generating a random ID on this interface.
941 			 * Create a new one.
942 			 */
943 			(void)generate_tmp_ifid(ndi->randomseed0,
944 			    ndi->randomseed1, ndi->randomid);
945 		}
946 	}
947 
948 	CURVNET_RESTORE();
949 }
950 
951 static void
952 in6_purgemaddrs(struct ifnet *ifp)
953 {
954 	LIST_HEAD(,in6_multi)	 purgeinms;
955 	struct in6_multi	*inm, *tinm;
956 	struct ifmultiaddr	*ifma;
957 
958 	LIST_INIT(&purgeinms);
959 	IN6_MULTI_LOCK();
960 
961 	/*
962 	 * Extract list of in6_multi associated with the detaching ifp
963 	 * which the PF_INET6 layer is about to release.
964 	 * We need to do this as IF_ADDR_LOCK() may be re-acquired
965 	 * by code further down.
966 	 */
967 	IF_ADDR_RLOCK(ifp);
968 	TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
969 		if (ifma->ifma_addr->sa_family != AF_INET6 ||
970 		    ifma->ifma_protospec == NULL)
971 			continue;
972 		inm = (struct in6_multi *)ifma->ifma_protospec;
973 		LIST_INSERT_HEAD(&purgeinms, inm, in6m_entry);
974 	}
975 	IF_ADDR_RUNLOCK(ifp);
976 
977 	LIST_FOREACH_SAFE(inm, &purgeinms, in6m_entry, tinm) {
978 		LIST_REMOVE(inm, in6m_entry);
979 		in6m_release_locked(inm);
980 	}
981 	mld_ifdetach(ifp);
982 
983 	IN6_MULTI_UNLOCK();
984 }
985