xref: /freebsd/sys/netinet6/in6_ifattach.c (revision d8a0fe102c0cfdfcd5b818f850eff09d8536c9bc)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the project nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	$KAME: in6_ifattach.c,v 1.118 2001/05/24 07:44:00 itojun Exp $
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/malloc.h>
40 #include <sys/socket.h>
41 #include <sys/sockio.h>
42 #include <sys/jail.h>
43 #include <sys/kernel.h>
44 #include <sys/lock.h>
45 #include <sys/proc.h>
46 #include <sys/rmlock.h>
47 #include <sys/syslog.h>
48 #include <sys/md5.h>
49 
50 #include <net/if.h>
51 #include <net/if_var.h>
52 #include <net/if_dl.h>
53 #include <net/if_types.h>
54 #include <net/route.h>
55 #include <net/vnet.h>
56 
57 #include <netinet/in.h>
58 #include <netinet/in_var.h>
59 #include <netinet/if_ether.h>
60 #include <netinet/in_pcb.h>
61 #include <netinet/ip_var.h>
62 #include <netinet/udp.h>
63 #include <netinet/udp_var.h>
64 
65 #include <netinet/ip6.h>
66 #include <netinet6/ip6_var.h>
67 #include <netinet6/in6_var.h>
68 #include <netinet6/in6_pcb.h>
69 #include <netinet6/in6_ifattach.h>
70 #include <netinet6/ip6_var.h>
71 #include <netinet6/nd6.h>
72 #include <netinet6/mld6_var.h>
73 #include <netinet6/scope6_var.h>
74 
75 VNET_DEFINE(unsigned long, in6_maxmtu) = 0;
76 
77 #ifdef IP6_AUTO_LINKLOCAL
78 VNET_DEFINE(int, ip6_auto_linklocal) = IP6_AUTO_LINKLOCAL;
79 #else
80 VNET_DEFINE(int, ip6_auto_linklocal) = 1;	/* enabled by default */
81 #endif
82 
83 VNET_DEFINE(struct callout, in6_tmpaddrtimer_ch);
84 #define	V_in6_tmpaddrtimer_ch		VNET(in6_tmpaddrtimer_ch)
85 
86 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
87 #define	V_ripcbinfo			VNET(ripcbinfo)
88 
89 static int get_rand_ifid(struct ifnet *, struct in6_addr *);
90 static int generate_tmp_ifid(u_int8_t *, const u_int8_t *, u_int8_t *);
91 static int get_ifid(struct ifnet *, struct ifnet *, struct in6_addr *);
92 static int in6_ifattach_linklocal(struct ifnet *, struct ifnet *);
93 static int in6_ifattach_loopback(struct ifnet *);
94 static void in6_purgemaddrs(struct ifnet *);
95 
96 #define EUI64_GBIT	0x01
97 #define EUI64_UBIT	0x02
98 #define EUI64_TO_IFID(in6)	do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (0)
99 #define EUI64_GROUP(in6)	((in6)->s6_addr[8] & EUI64_GBIT)
100 #define EUI64_INDIVIDUAL(in6)	(!EUI64_GROUP(in6))
101 #define EUI64_LOCAL(in6)	((in6)->s6_addr[8] & EUI64_UBIT)
102 #define EUI64_UNIVERSAL(in6)	(!EUI64_LOCAL(in6))
103 
104 #define IFID_LOCAL(in6)		(!EUI64_LOCAL(in6))
105 #define IFID_UNIVERSAL(in6)	(!EUI64_UNIVERSAL(in6))
106 
107 /*
108  * Generate a last-resort interface identifier, when the machine has no
109  * IEEE802/EUI64 address sources.
110  * The goal here is to get an interface identifier that is
111  * (1) random enough and (2) does not change across reboot.
112  * We currently use MD5(hostname) for it.
113  *
114  * in6 - upper 64bits are preserved
115  */
116 static int
117 get_rand_ifid(struct ifnet *ifp, struct in6_addr *in6)
118 {
119 	MD5_CTX ctxt;
120 	struct prison *pr;
121 	u_int8_t digest[16];
122 	int hostnamelen;
123 
124 	pr = curthread->td_ucred->cr_prison;
125 	mtx_lock(&pr->pr_mtx);
126 	hostnamelen = strlen(pr->pr_hostname);
127 #if 0
128 	/* we need at least several letters as seed for ifid */
129 	if (hostnamelen < 3) {
130 		mtx_unlock(&pr->pr_mtx);
131 		return -1;
132 	}
133 #endif
134 
135 	/* generate 8 bytes of pseudo-random value. */
136 	bzero(&ctxt, sizeof(ctxt));
137 	MD5Init(&ctxt);
138 	MD5Update(&ctxt, pr->pr_hostname, hostnamelen);
139 	mtx_unlock(&pr->pr_mtx);
140 	MD5Final(digest, &ctxt);
141 
142 	/* assumes sizeof(digest) > sizeof(ifid) */
143 	bcopy(digest, &in6->s6_addr[8], 8);
144 
145 	/* make sure to set "u" bit to local, and "g" bit to individual. */
146 	in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
147 	in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
148 
149 	/* convert EUI64 into IPv6 interface identifier */
150 	EUI64_TO_IFID(in6);
151 
152 	return 0;
153 }
154 
155 static int
156 generate_tmp_ifid(u_int8_t *seed0, const u_int8_t *seed1, u_int8_t *ret)
157 {
158 	MD5_CTX ctxt;
159 	u_int8_t seed[16], digest[16], nullbuf[8];
160 	u_int32_t val32;
161 
162 	/* If there's no history, start with a random seed. */
163 	bzero(nullbuf, sizeof(nullbuf));
164 	if (bcmp(nullbuf, seed0, sizeof(nullbuf)) == 0) {
165 		int i;
166 
167 		for (i = 0; i < 2; i++) {
168 			val32 = arc4random();
169 			bcopy(&val32, seed + sizeof(val32) * i, sizeof(val32));
170 		}
171 	} else
172 		bcopy(seed0, seed, 8);
173 
174 	/* copy the right-most 64-bits of the given address */
175 	/* XXX assumption on the size of IFID */
176 	bcopy(seed1, &seed[8], 8);
177 
178 	if (0) {		/* for debugging purposes only */
179 		int i;
180 
181 		printf("generate_tmp_ifid: new randomized ID from: ");
182 		for (i = 0; i < 16; i++)
183 			printf("%02x", seed[i]);
184 		printf(" ");
185 	}
186 
187 	/* generate 16 bytes of pseudo-random value. */
188 	bzero(&ctxt, sizeof(ctxt));
189 	MD5Init(&ctxt);
190 	MD5Update(&ctxt, seed, sizeof(seed));
191 	MD5Final(digest, &ctxt);
192 
193 	/*
194 	 * RFC 3041 3.2.1. (3)
195 	 * Take the left-most 64-bits of the MD5 digest and set bit 6 (the
196 	 * left-most bit is numbered 0) to zero.
197 	 */
198 	bcopy(digest, ret, 8);
199 	ret[0] &= ~EUI64_UBIT;
200 
201 	/*
202 	 * XXX: we'd like to ensure that the generated value is not zero
203 	 * for simplicity.  If the caclculated digest happens to be zero,
204 	 * use a random non-zero value as the last resort.
205 	 */
206 	if (bcmp(nullbuf, ret, sizeof(nullbuf)) == 0) {
207 		nd6log((LOG_INFO,
208 		    "generate_tmp_ifid: computed MD5 value is zero.\n"));
209 
210 		val32 = arc4random();
211 		val32 = 1 + (val32 % (0xffffffff - 1));
212 	}
213 
214 	/*
215 	 * RFC 3041 3.2.1. (4)
216 	 * Take the rightmost 64-bits of the MD5 digest and save them in
217 	 * stable storage as the history value to be used in the next
218 	 * iteration of the algorithm.
219 	 */
220 	bcopy(&digest[8], seed0, 8);
221 
222 	if (0) {		/* for debugging purposes only */
223 		int i;
224 
225 		printf("to: ");
226 		for (i = 0; i < 16; i++)
227 			printf("%02x", digest[i]);
228 		printf("\n");
229 	}
230 
231 	return 0;
232 }
233 
234 /*
235  * Get interface identifier for the specified interface.
236  * XXX assumes single sockaddr_dl (AF_LINK address) per an interface
237  *
238  * in6 - upper 64bits are preserved
239  */
240 int
241 in6_get_hw_ifid(struct ifnet *ifp, struct in6_addr *in6)
242 {
243 	struct ifaddr *ifa;
244 	struct sockaddr_dl *sdl;
245 	u_int8_t *addr;
246 	size_t addrlen;
247 	static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
248 	static u_int8_t allone[8] =
249 		{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
250 
251 	IF_ADDR_RLOCK(ifp);
252 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
253 		if (ifa->ifa_addr->sa_family != AF_LINK)
254 			continue;
255 		sdl = (struct sockaddr_dl *)ifa->ifa_addr;
256 		if (sdl == NULL)
257 			continue;
258 		if (sdl->sdl_alen == 0)
259 			continue;
260 
261 		goto found;
262 	}
263 	IF_ADDR_RUNLOCK(ifp);
264 
265 	return -1;
266 
267 found:
268 	IF_ADDR_LOCK_ASSERT(ifp);
269 	addr = LLADDR(sdl);
270 	addrlen = sdl->sdl_alen;
271 
272 	/* get EUI64 */
273 	switch (ifp->if_type) {
274 	case IFT_BRIDGE:
275 	case IFT_ETHER:
276 	case IFT_L2VLAN:
277 	case IFT_FDDI:
278 	case IFT_ISO88025:
279 	case IFT_ATM:
280 	case IFT_IEEE1394:
281 		/* IEEE802/EUI64 cases - what others? */
282 		/* IEEE1394 uses 16byte length address starting with EUI64 */
283 		if (addrlen > 8)
284 			addrlen = 8;
285 
286 		/* look at IEEE802/EUI64 only */
287 		if (addrlen != 8 && addrlen != 6) {
288 			IF_ADDR_RUNLOCK(ifp);
289 			return -1;
290 		}
291 
292 		/*
293 		 * check for invalid MAC address - on bsdi, we see it a lot
294 		 * since wildboar configures all-zero MAC on pccard before
295 		 * card insertion.
296 		 */
297 		if (bcmp(addr, allzero, addrlen) == 0) {
298 			IF_ADDR_RUNLOCK(ifp);
299 			return -1;
300 		}
301 		if (bcmp(addr, allone, addrlen) == 0) {
302 			IF_ADDR_RUNLOCK(ifp);
303 			return -1;
304 		}
305 
306 		/* make EUI64 address */
307 		if (addrlen == 8)
308 			bcopy(addr, &in6->s6_addr[8], 8);
309 		else if (addrlen == 6) {
310 			in6->s6_addr[8] = addr[0];
311 			in6->s6_addr[9] = addr[1];
312 			in6->s6_addr[10] = addr[2];
313 			in6->s6_addr[11] = 0xff;
314 			in6->s6_addr[12] = 0xfe;
315 			in6->s6_addr[13] = addr[3];
316 			in6->s6_addr[14] = addr[4];
317 			in6->s6_addr[15] = addr[5];
318 		}
319 		break;
320 
321 	case IFT_ARCNET:
322 		if (addrlen != 1) {
323 			IF_ADDR_RUNLOCK(ifp);
324 			return -1;
325 		}
326 		if (!addr[0]) {
327 			IF_ADDR_RUNLOCK(ifp);
328 			return -1;
329 		}
330 
331 		bzero(&in6->s6_addr[8], 8);
332 		in6->s6_addr[15] = addr[0];
333 
334 		/*
335 		 * due to insufficient bitwidth, we mark it local.
336 		 */
337 		in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
338 		in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
339 		break;
340 
341 	case IFT_GIF:
342 	case IFT_STF:
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_link) {
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 	struct nd_prefix *pr;
458 	int error;
459 
460 	/*
461 	 * configure link-local address.
462 	 */
463 	in6_prepare_ifra(&ifra, NULL, &in6mask64);
464 
465 	ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000);
466 	ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
467 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
468 		ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
469 		ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
470 	} else {
471 		if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) {
472 			nd6log((LOG_ERR,
473 			    "%s: no ifid available\n", if_name(ifp)));
474 			return (-1);
475 		}
476 	}
477 	if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL))
478 		return (-1);
479 
480 	/* link-local addresses should NEVER expire. */
481 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
482 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
483 
484 	/*
485 	 * Now call in6_update_ifa() to do a bunch of procedures to configure
486 	 * a link-local address. We can set the 3rd argument to NULL, because
487 	 * we know there's no other link-local address on the interface
488 	 * and therefore we are adding one (instead of updating one).
489 	 */
490 	if ((error = in6_update_ifa(ifp, &ifra, NULL,
491 				    IN6_IFAUPDATE_DADDELAY)) != 0) {
492 		/*
493 		 * XXX: When the interface does not support IPv6, this call
494 		 * would fail in the SIOCSIFADDR ioctl.  I believe the
495 		 * notification is rather confusing in this case, so just
496 		 * suppress it.  (jinmei@kame.net 20010130)
497 		 */
498 		if (error != EAFNOSUPPORT)
499 			nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to "
500 			    "configure a link-local address on %s "
501 			    "(errno=%d)\n",
502 			    if_name(ifp), error));
503 		return (-1);
504 	}
505 
506 	ia = in6ifa_ifpforlinklocal(ifp, 0); /* ia must not be NULL */
507 	KASSERT(ia != NULL, ("%s: ia == NULL, ifp=%p", __func__, ifp));
508 
509 	ifa_free(&ia->ia_ifa);
510 
511 	/*
512 	 * Make the link-local prefix (fe80::%link/64) as on-link.
513 	 * Since we'd like to manage prefixes separately from addresses,
514 	 * we make an ND6 prefix structure for the link-local prefix,
515 	 * and add it to the prefix list as a never-expire prefix.
516 	 * XXX: this change might affect some existing code base...
517 	 */
518 	bzero(&pr0, sizeof(pr0));
519 	pr0.ndpr_ifp = ifp;
520 	/* this should be 64 at this moment. */
521 	pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
522 	pr0.ndpr_prefix = ifra.ifra_addr;
523 	/* apply the mask for safety. (nd6_prelist_add will apply it again) */
524 	IN6_MASK_ADDR(&pr0.ndpr_prefix.sin6_addr, &in6mask64);
525 	/*
526 	 * Initialize parameters.  The link-local prefix must always be
527 	 * on-link, and its lifetimes never expire.
528 	 */
529 	pr0.ndpr_raf_onlink = 1;
530 	pr0.ndpr_raf_auto = 1;	/* probably meaningless */
531 	pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
532 	pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
533 	/*
534 	 * Since there is no other link-local addresses, nd6_prefix_lookup()
535 	 * probably returns NULL.  However, we cannot always expect the result.
536 	 * For example, if we first remove the (only) existing link-local
537 	 * address, and then reconfigure another one, the prefix is still
538 	 * valid with referring to the old link-local address.
539 	 */
540 	if ((pr = nd6_prefix_lookup(&pr0)) == NULL) {
541 		if ((error = nd6_prelist_add(&pr0, NULL, NULL)) != 0)
542 			return (error);
543 	} else
544 		nd6_prefix_rele(pr);
545 
546 	return 0;
547 }
548 
549 /*
550  * ifp - must be IFT_LOOP
551  */
552 static int
553 in6_ifattach_loopback(struct ifnet *ifp)
554 {
555 	struct in6_aliasreq ifra;
556 	int error;
557 
558 	in6_prepare_ifra(&ifra, &in6addr_loopback, &in6mask128);
559 
560 	/*
561 	 * Always initialize ia_dstaddr (= broadcast address) to loopback
562 	 * address.  Follows IPv4 practice - see in_ifinit().
563 	 */
564 	ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
565 	ifra.ifra_dstaddr.sin6_family = AF_INET6;
566 	ifra.ifra_dstaddr.sin6_addr = in6addr_loopback;
567 
568 	/* the loopback  address should NEVER expire. */
569 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
570 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
571 
572 	/*
573 	 * We are sure that this is a newly assigned address, so we can set
574 	 * NULL to the 3rd arg.
575 	 */
576 	if ((error = in6_update_ifa(ifp, &ifra, NULL, 0)) != 0) {
577 		nd6log((LOG_ERR, "in6_ifattach_loopback: failed to configure "
578 		    "the loopback address on %s (errno=%d)\n",
579 		    if_name(ifp), error));
580 		return (-1);
581 	}
582 
583 	return 0;
584 }
585 
586 /*
587  * compute NI group address, based on the current hostname setting.
588  * see RFC 4620.
589  *
590  * when ifp == NULL, the caller is responsible for filling scopeid.
591  *
592  * If oldmcprefix == 1, FF02:0:0:0:0:2::/96 is used for NI group address
593  * while it is FF02:0:0:0:0:2:FF00::/104 in RFC 4620.
594  */
595 static int
596 in6_nigroup0(struct ifnet *ifp, const char *name, int namelen,
597     struct in6_addr *in6, int oldmcprefix)
598 {
599 	struct prison *pr;
600 	const char *p;
601 	u_char *q;
602 	MD5_CTX ctxt;
603 	u_int8_t digest[16];
604 	char l;
605 	char n[64];	/* a single label must not exceed 63 chars */
606 
607 	/*
608 	 * If no name is given and namelen is -1,
609 	 * we try to do the hostname lookup ourselves.
610 	 */
611 	if (!name && namelen == -1) {
612 		pr = curthread->td_ucred->cr_prison;
613 		mtx_lock(&pr->pr_mtx);
614 		name = pr->pr_hostname;
615 		namelen = strlen(name);
616 	} else
617 		pr = NULL;
618 	if (!name || !namelen) {
619 		if (pr != NULL)
620 			mtx_unlock(&pr->pr_mtx);
621 		return -1;
622 	}
623 
624 	p = name;
625 	while (p && *p && *p != '.' && p - name < namelen)
626 		p++;
627 	if (p == name || p - name > sizeof(n) - 1) {
628 		if (pr != NULL)
629 			mtx_unlock(&pr->pr_mtx);
630 		return -1;	/* label too long */
631 	}
632 	l = p - name;
633 	strncpy(n, name, l);
634 	if (pr != NULL)
635 		mtx_unlock(&pr->pr_mtx);
636 	n[(int)l] = '\0';
637 	for (q = n; *q; q++) {
638 		if ('A' <= *q && *q <= 'Z')
639 			*q = *q - 'A' + 'a';
640 	}
641 
642 	/* generate 16 bytes of pseudo-random value. */
643 	bzero(&ctxt, sizeof(ctxt));
644 	MD5Init(&ctxt);
645 	MD5Update(&ctxt, &l, sizeof(l));
646 	MD5Update(&ctxt, n, l);
647 	MD5Final(digest, &ctxt);
648 
649 	bzero(in6, sizeof(*in6));
650 	in6->s6_addr16[0] = IPV6_ADDR_INT16_MLL;
651 	in6->s6_addr8[11] = 2;
652 	if (oldmcprefix == 0) {
653 		in6->s6_addr8[12] = 0xff;
654 	 	/* Copy the first 24 bits of 128-bit hash into the address. */
655 		bcopy(digest, &in6->s6_addr8[13], 3);
656 	} else {
657 	 	/* Copy the first 32 bits of 128-bit hash into the address. */
658 		bcopy(digest, &in6->s6_addr32[3], sizeof(in6->s6_addr32[3]));
659 	}
660 	if (in6_setscope(in6, ifp, NULL))
661 		return (-1); /* XXX: should not fail */
662 
663 	return 0;
664 }
665 
666 int
667 in6_nigroup(struct ifnet *ifp, const char *name, int namelen,
668     struct in6_addr *in6)
669 {
670 
671 	return (in6_nigroup0(ifp, name, namelen, in6, 0));
672 }
673 
674 int
675 in6_nigroup_oldmcprefix(struct ifnet *ifp, const char *name, int namelen,
676     struct in6_addr *in6)
677 {
678 
679 	return (in6_nigroup0(ifp, name, namelen, in6, 1));
680 }
681 
682 /*
683  * XXX multiple loopback interface needs more care.  for instance,
684  * nodelocal address needs to be configured onto only one of them.
685  * XXX multiple link-local address case
686  *
687  * altifp - secondary EUI64 source
688  */
689 void
690 in6_ifattach(struct ifnet *ifp, struct ifnet *altifp)
691 {
692 	struct in6_ifaddr *ia;
693 	struct in6_addr in6;
694 
695 	if (ifp->if_afdata[AF_INET6] == NULL)
696 		return;
697 	/*
698 	 * quirks based on interface type
699 	 */
700 	switch (ifp->if_type) {
701 	case IFT_STF:
702 		/*
703 		 * 6to4 interface is a very special kind of beast.
704 		 * no multicast, no linklocal.  RFC2529 specifies how to make
705 		 * linklocals for 6to4 interface, but there's no use and
706 		 * it is rather harmful to have one.
707 		 */
708 		ND_IFINFO(ifp)->flags &= ~ND6_IFF_AUTO_LINKLOCAL;
709 		break;
710 	default:
711 		break;
712 	}
713 
714 	/*
715 	 * usually, we require multicast capability to the interface
716 	 */
717 	if ((ifp->if_flags & IFF_MULTICAST) == 0) {
718 		nd6log((LOG_INFO, "in6_ifattach: "
719 		    "%s is not multicast capable, IPv6 not enabled\n",
720 		    if_name(ifp)));
721 		return;
722 	}
723 
724 	/*
725 	 * assign loopback address for loopback interface.
726 	 * XXX multiple loopback interface case.
727 	 */
728 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
729 		struct ifaddr *ifa;
730 
731 		in6 = in6addr_loopback;
732 		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &in6);
733 		if (ifa == NULL) {
734 			if (in6_ifattach_loopback(ifp) != 0)
735 				return;
736 		} else
737 			ifa_free(ifa);
738 	}
739 
740 	/*
741 	 * assign a link-local address, if there's none.
742 	 */
743 	if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
744 	    ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL) {
745 		int error;
746 
747 		ia = in6ifa_ifpforlinklocal(ifp, 0);
748 		if (ia == NULL) {
749 			error = in6_ifattach_linklocal(ifp, altifp);
750 #if 0
751 			if (error)
752 				log(LOG_NOTICE, "in6_ifattach_linklocal: "
753 				    "failed to add a link-local addr to %s\n",
754 				    if_name(ifp));
755 #endif
756 		} else
757 			ifa_free(&ia->ia_ifa);
758 	}
759 
760 	/* update dynamically. */
761 	if (V_in6_maxmtu < ifp->if_mtu)
762 		V_in6_maxmtu = ifp->if_mtu;
763 }
764 
765 /*
766  * NOTE: in6_ifdetach() does not support loopback if at this moment.
767  *
768  * When shutting down a VNET we clean up layers top-down.  In that case
769  * upper layer protocols (ulp) are cleaned up already and locks are destroyed
770  * and we must not call into these cleanup functions anymore, thus purgeulp
771  * is set to 0 in that case by in6_ifdetach_destroy().
772  * The normal case of destroying a (cloned) interface still needs to cleanup
773  * everything related to the interface and will have purgeulp set to 1.
774  */
775 static void
776 _in6_ifdetach(struct ifnet *ifp, int purgeulp)
777 {
778 	struct ifaddr *ifa, *next;
779 
780 	if (ifp->if_afdata[AF_INET6] == NULL)
781 		return;
782 
783 	/*
784 	 * nuke any of IPv6 addresses we have
785 	 * XXX: all addresses should be already removed
786 	 */
787 	TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
788 		if (ifa->ifa_addr->sa_family != AF_INET6)
789 			continue;
790 		in6_purgeaddr(ifa);
791 	}
792 	if (purgeulp) {
793 		in6_pcbpurgeif0(&V_udbinfo, ifp);
794 		in6_pcbpurgeif0(&V_ulitecbinfo, ifp);
795 		in6_pcbpurgeif0(&V_ripcbinfo, ifp);
796 	}
797 	/* leave from all multicast groups joined */
798 	in6_purgemaddrs(ifp);
799 
800 	/*
801 	 * Remove neighbor management table.
802 	 * Enabling the nd6_purge will panic on vmove for interfaces on VNET
803 	 * teardown as the IPv6 layer is cleaned up already and the locks
804 	 * are destroyed.
805 	 */
806 	if (purgeulp)
807 		nd6_purge(ifp);
808 }
809 
810 void
811 in6_ifdetach(struct ifnet *ifp)
812 {
813 
814 	_in6_ifdetach(ifp, 1);
815 }
816 
817 void
818 in6_ifdetach_destroy(struct ifnet *ifp)
819 {
820 
821 	_in6_ifdetach(ifp, 0);
822 }
823 
824 int
825 in6_get_tmpifid(struct ifnet *ifp, u_int8_t *retbuf,
826     const u_int8_t *baseid, int generate)
827 {
828 	u_int8_t nullbuf[8];
829 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
830 
831 	bzero(nullbuf, sizeof(nullbuf));
832 	if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
833 		/* we've never created a random ID.  Create a new one. */
834 		generate = 1;
835 	}
836 
837 	if (generate) {
838 		bcopy(baseid, ndi->randomseed1, sizeof(ndi->randomseed1));
839 
840 		/* generate_tmp_ifid will update seedn and buf */
841 		(void)generate_tmp_ifid(ndi->randomseed0, ndi->randomseed1,
842 		    ndi->randomid);
843 	}
844 	bcopy(ndi->randomid, retbuf, 8);
845 
846 	return (0);
847 }
848 
849 void
850 in6_tmpaddrtimer(void *arg)
851 {
852 	CURVNET_SET((struct vnet *) arg);
853 	struct nd_ifinfo *ndi;
854 	u_int8_t nullbuf[8];
855 	struct ifnet *ifp;
856 
857 	callout_reset(&V_in6_tmpaddrtimer_ch,
858 	    (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
859 	    V_ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, curvnet);
860 
861 	bzero(nullbuf, sizeof(nullbuf));
862 	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
863 		if (ifp->if_afdata[AF_INET6] == NULL)
864 			continue;
865 		ndi = ND_IFINFO(ifp);
866 		if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
867 			/*
868 			 * We've been generating a random ID on this interface.
869 			 * Create a new one.
870 			 */
871 			(void)generate_tmp_ifid(ndi->randomseed0,
872 			    ndi->randomseed1, ndi->randomid);
873 		}
874 	}
875 
876 	CURVNET_RESTORE();
877 }
878 
879 static void
880 in6_purgemaddrs(struct ifnet *ifp)
881 {
882 	LIST_HEAD(,in6_multi)	 purgeinms;
883 	struct in6_multi	*inm, *tinm;
884 	struct ifmultiaddr	*ifma;
885 
886 	LIST_INIT(&purgeinms);
887 	IN6_MULTI_LOCK();
888 
889 	/*
890 	 * Extract list of in6_multi associated with the detaching ifp
891 	 * which the PF_INET6 layer is about to release.
892 	 * We need to do this as IF_ADDR_LOCK() may be re-acquired
893 	 * by code further down.
894 	 */
895 	IF_ADDR_RLOCK(ifp);
896 	TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
897 		if (ifma->ifma_addr->sa_family != AF_INET6 ||
898 		    ifma->ifma_protospec == NULL)
899 			continue;
900 		inm = (struct in6_multi *)ifma->ifma_protospec;
901 		LIST_INSERT_HEAD(&purgeinms, inm, in6m_entry);
902 	}
903 	IF_ADDR_RUNLOCK(ifp);
904 
905 	LIST_FOREACH_SAFE(inm, &purgeinms, in6m_entry, tinm) {
906 		LIST_REMOVE(inm, in6m_entry);
907 		in6m_release_locked(inm);
908 	}
909 	mld_ifdetach(ifp);
910 
911 	IN6_MULTI_UNLOCK();
912 }
913 
914 void
915 in6_ifattach_destroy(void)
916 {
917 
918 	callout_drain(&V_in6_tmpaddrtimer_ch);
919 }
920 
921 static void
922 in6_ifattach_init(void *dummy)
923 {
924 
925 	/* Timer for regeneranation of temporary addresses randomize ID. */
926 	callout_init(&V_in6_tmpaddrtimer_ch, 0);
927 	callout_reset(&V_in6_tmpaddrtimer_ch,
928 	    (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
929 	    V_ip6_temp_regen_advance) * hz,
930 	    in6_tmpaddrtimer, curvnet);
931 }
932 
933 /*
934  * Cheat.
935  * This must be after route_init(), which is now SI_ORDER_THIRD.
936  */
937 SYSINIT(in6_ifattach_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
938     in6_ifattach_init, NULL);
939