xref: /freebsd/sys/netinet6/in6_ifattach.c (revision b2d48be1bc7df45ddd13b143a160d0acb5a383c5)
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/lock.h>
43 #include <sys/proc.h>
44 #include <sys/rmlock.h>
45 #include <sys/syslog.h>
46 #include <sys/md5.h>
47 
48 #include <net/if.h>
49 #include <net/if_var.h>
50 #include <net/if_dl.h>
51 #include <net/if_types.h>
52 #include <net/route.h>
53 #include <net/vnet.h>
54 
55 #include <netinet/in.h>
56 #include <netinet/in_var.h>
57 #include <netinet/if_ether.h>
58 #include <netinet/in_pcb.h>
59 #include <netinet/ip_var.h>
60 #include <netinet/udp.h>
61 #include <netinet/udp_var.h>
62 
63 #include <netinet/ip6.h>
64 #include <netinet6/ip6_var.h>
65 #include <netinet6/in6_var.h>
66 #include <netinet6/in6_pcb.h>
67 #include <netinet6/in6_ifattach.h>
68 #include <netinet6/ip6_var.h>
69 #include <netinet6/nd6.h>
70 #include <netinet6/mld6_var.h>
71 #include <netinet6/scope6_var.h>
72 
73 VNET_DEFINE(unsigned long, in6_maxmtu) = 0;
74 
75 #ifdef IP6_AUTO_LINKLOCAL
76 VNET_DEFINE(int, ip6_auto_linklocal) = IP6_AUTO_LINKLOCAL;
77 #else
78 VNET_DEFINE(int, ip6_auto_linklocal) = 1;	/* enabled by default */
79 #endif
80 
81 VNET_DEFINE(struct callout, in6_tmpaddrtimer_ch);
82 #define	V_in6_tmpaddrtimer_ch		VNET(in6_tmpaddrtimer_ch)
83 
84 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
85 #define	V_ripcbinfo			VNET(ripcbinfo)
86 
87 static int get_rand_ifid(struct ifnet *, struct in6_addr *);
88 static int generate_tmp_ifid(u_int8_t *, const u_int8_t *, u_int8_t *);
89 static int get_ifid(struct ifnet *, struct ifnet *, struct in6_addr *);
90 static int in6_ifattach_linklocal(struct ifnet *, struct ifnet *);
91 static int in6_ifattach_loopback(struct ifnet *);
92 static void in6_purgemaddrs(struct ifnet *);
93 
94 #define EUI64_GBIT	0x01
95 #define EUI64_UBIT	0x02
96 #define EUI64_TO_IFID(in6)	do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (0)
97 #define EUI64_GROUP(in6)	((in6)->s6_addr[8] & EUI64_GBIT)
98 #define EUI64_INDIVIDUAL(in6)	(!EUI64_GROUP(in6))
99 #define EUI64_LOCAL(in6)	((in6)->s6_addr[8] & EUI64_UBIT)
100 #define EUI64_UNIVERSAL(in6)	(!EUI64_LOCAL(in6))
101 
102 #define IFID_LOCAL(in6)		(!EUI64_LOCAL(in6))
103 #define IFID_UNIVERSAL(in6)	(!EUI64_UNIVERSAL(in6))
104 
105 /*
106  * Generate a last-resort interface identifier, when the machine has no
107  * IEEE802/EUI64 address sources.
108  * The goal here is to get an interface identifier that is
109  * (1) random enough and (2) does not change across reboot.
110  * We currently use MD5(hostname) for it.
111  *
112  * in6 - upper 64bits are preserved
113  */
114 static int
115 get_rand_ifid(struct ifnet *ifp, struct in6_addr *in6)
116 {
117 	MD5_CTX ctxt;
118 	struct prison *pr;
119 	u_int8_t digest[16];
120 	int hostnamelen;
121 
122 	pr = curthread->td_ucred->cr_prison;
123 	mtx_lock(&pr->pr_mtx);
124 	hostnamelen = strlen(pr->pr_hostname);
125 #if 0
126 	/* we need at least several letters as seed for ifid */
127 	if (hostnamelen < 3) {
128 		mtx_unlock(&pr->pr_mtx);
129 		return -1;
130 	}
131 #endif
132 
133 	/* generate 8 bytes of pseudo-random value. */
134 	bzero(&ctxt, sizeof(ctxt));
135 	MD5Init(&ctxt);
136 	MD5Update(&ctxt, pr->pr_hostname, hostnamelen);
137 	mtx_unlock(&pr->pr_mtx);
138 	MD5Final(digest, &ctxt);
139 
140 	/* assumes sizeof(digest) > sizeof(ifid) */
141 	bcopy(digest, &in6->s6_addr[8], 8);
142 
143 	/* make sure to set "u" bit to local, and "g" bit to individual. */
144 	in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
145 	in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
146 
147 	/* convert EUI64 into IPv6 interface identifier */
148 	EUI64_TO_IFID(in6);
149 
150 	return 0;
151 }
152 
153 static int
154 generate_tmp_ifid(u_int8_t *seed0, const u_int8_t *seed1, u_int8_t *ret)
155 {
156 	MD5_CTX ctxt;
157 	u_int8_t seed[16], digest[16], nullbuf[8];
158 	u_int32_t val32;
159 
160 	/* If there's no history, start with a random seed. */
161 	bzero(nullbuf, sizeof(nullbuf));
162 	if (bcmp(nullbuf, seed0, sizeof(nullbuf)) == 0) {
163 		int i;
164 
165 		for (i = 0; i < 2; i++) {
166 			val32 = arc4random();
167 			bcopy(&val32, seed + sizeof(val32) * i, sizeof(val32));
168 		}
169 	} else
170 		bcopy(seed0, seed, 8);
171 
172 	/* copy the right-most 64-bits of the given address */
173 	/* XXX assumption on the size of IFID */
174 	bcopy(seed1, &seed[8], 8);
175 
176 	if (0) {		/* for debugging purposes only */
177 		int i;
178 
179 		printf("generate_tmp_ifid: new randomized ID from: ");
180 		for (i = 0; i < 16; i++)
181 			printf("%02x", seed[i]);
182 		printf(" ");
183 	}
184 
185 	/* generate 16 bytes of pseudo-random value. */
186 	bzero(&ctxt, sizeof(ctxt));
187 	MD5Init(&ctxt);
188 	MD5Update(&ctxt, seed, sizeof(seed));
189 	MD5Final(digest, &ctxt);
190 
191 	/*
192 	 * RFC 3041 3.2.1. (3)
193 	 * Take the left-most 64-bits of the MD5 digest and set bit 6 (the
194 	 * left-most bit is numbered 0) to zero.
195 	 */
196 	bcopy(digest, ret, 8);
197 	ret[0] &= ~EUI64_UBIT;
198 
199 	/*
200 	 * XXX: we'd like to ensure that the generated value is not zero
201 	 * for simplicity.  If the caclculated digest happens to be zero,
202 	 * use a random non-zero value as the last resort.
203 	 */
204 	if (bcmp(nullbuf, ret, sizeof(nullbuf)) == 0) {
205 		nd6log((LOG_INFO,
206 		    "generate_tmp_ifid: computed MD5 value is zero.\n"));
207 
208 		val32 = arc4random();
209 		val32 = 1 + (val32 % (0xffffffff - 1));
210 	}
211 
212 	/*
213 	 * RFC 3041 3.2.1. (4)
214 	 * Take the rightmost 64-bits of the MD5 digest and save them in
215 	 * stable storage as the history value to be used in the next
216 	 * iteration of the algorithm.
217 	 */
218 	bcopy(&digest[8], seed0, 8);
219 
220 	if (0) {		/* for debugging purposes only */
221 		int i;
222 
223 		printf("to: ");
224 		for (i = 0; i < 16; i++)
225 			printf("%02x", digest[i]);
226 		printf("\n");
227 	}
228 
229 	return 0;
230 }
231 
232 /*
233  * Get interface identifier for the specified interface.
234  * XXX assumes single sockaddr_dl (AF_LINK address) per an interface
235  *
236  * in6 - upper 64bits are preserved
237  */
238 int
239 in6_get_hw_ifid(struct ifnet *ifp, struct in6_addr *in6)
240 {
241 	struct ifaddr *ifa;
242 	struct sockaddr_dl *sdl;
243 	u_int8_t *addr;
244 	size_t addrlen;
245 	static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
246 	static u_int8_t allone[8] =
247 		{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
248 
249 	IF_ADDR_RLOCK(ifp);
250 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
251 		if (ifa->ifa_addr->sa_family != AF_LINK)
252 			continue;
253 		sdl = (struct sockaddr_dl *)ifa->ifa_addr;
254 		if (sdl == NULL)
255 			continue;
256 		if (sdl->sdl_alen == 0)
257 			continue;
258 
259 		goto found;
260 	}
261 	IF_ADDR_RUNLOCK(ifp);
262 
263 	return -1;
264 
265 found:
266 	IF_ADDR_LOCK_ASSERT(ifp);
267 	addr = LLADDR(sdl);
268 	addrlen = sdl->sdl_alen;
269 
270 	/* get EUI64 */
271 	switch (ifp->if_type) {
272 	case IFT_BRIDGE:
273 	case IFT_ETHER:
274 	case IFT_L2VLAN:
275 	case IFT_FDDI:
276 	case IFT_ISO88025:
277 	case IFT_ATM:
278 	case IFT_IEEE1394:
279 	case IFT_IEEE80211:
280 		/* IEEE802/EUI64 cases - what others? */
281 		/* IEEE1394 uses 16byte length address starting with EUI64 */
282 		if (addrlen > 8)
283 			addrlen = 8;
284 
285 		/* look at IEEE802/EUI64 only */
286 		if (addrlen != 8 && addrlen != 6) {
287 			IF_ADDR_RUNLOCK(ifp);
288 			return -1;
289 		}
290 
291 		/*
292 		 * check for invalid MAC address - on bsdi, we see it a lot
293 		 * since wildboar configures all-zero MAC on pccard before
294 		 * card insertion.
295 		 */
296 		if (bcmp(addr, allzero, addrlen) == 0) {
297 			IF_ADDR_RUNLOCK(ifp);
298 			return -1;
299 		}
300 		if (bcmp(addr, allone, addrlen) == 0) {
301 			IF_ADDR_RUNLOCK(ifp);
302 			return -1;
303 		}
304 
305 		/* make EUI64 address */
306 		if (addrlen == 8)
307 			bcopy(addr, &in6->s6_addr[8], 8);
308 		else if (addrlen == 6) {
309 			in6->s6_addr[8] = addr[0];
310 			in6->s6_addr[9] = addr[1];
311 			in6->s6_addr[10] = addr[2];
312 			in6->s6_addr[11] = 0xff;
313 			in6->s6_addr[12] = 0xfe;
314 			in6->s6_addr[13] = addr[3];
315 			in6->s6_addr[14] = addr[4];
316 			in6->s6_addr[15] = addr[5];
317 		}
318 		break;
319 
320 	case IFT_ARCNET:
321 		if (addrlen != 1) {
322 			IF_ADDR_RUNLOCK(ifp);
323 			return -1;
324 		}
325 		if (!addr[0]) {
326 			IF_ADDR_RUNLOCK(ifp);
327 			return -1;
328 		}
329 
330 		bzero(&in6->s6_addr[8], 8);
331 		in6->s6_addr[15] = addr[0];
332 
333 		/*
334 		 * due to insufficient bitwidth, we mark it local.
335 		 */
336 		in6->s6_addr[8] &= ~EUI64_GBIT;	/* g bit to "individual" */
337 		in6->s6_addr[8] |= EUI64_UBIT;	/* u bit to "local" */
338 		break;
339 
340 	case IFT_GIF:
341 	case IFT_STF:
342 		/*
343 		 * RFC2893 says: "SHOULD use IPv4 address as ifid source".
344 		 * however, IPv4 address is not very suitable as unique
345 		 * identifier source (can be renumbered).
346 		 * we don't do this.
347 		 */
348 		IF_ADDR_RUNLOCK(ifp);
349 		return -1;
350 
351 	default:
352 		IF_ADDR_RUNLOCK(ifp);
353 		return -1;
354 	}
355 
356 	/* sanity check: g bit must not indicate "group" */
357 	if (EUI64_GROUP(in6)) {
358 		IF_ADDR_RUNLOCK(ifp);
359 		return -1;
360 	}
361 
362 	/* convert EUI64 into IPv6 interface identifier */
363 	EUI64_TO_IFID(in6);
364 
365 	/*
366 	 * sanity check: ifid must not be all zero, avoid conflict with
367 	 * subnet router anycast
368 	 */
369 	if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
370 	    bcmp(&in6->s6_addr[9], allzero, 7) == 0) {
371 		IF_ADDR_RUNLOCK(ifp);
372 		return -1;
373 	}
374 
375 	IF_ADDR_RUNLOCK(ifp);
376 	return 0;
377 }
378 
379 /*
380  * Get interface identifier for the specified interface.  If it is not
381  * available on ifp0, borrow interface identifier from other information
382  * sources.
383  *
384  * altifp - secondary EUI64 source
385  */
386 static int
387 get_ifid(struct ifnet *ifp0, struct ifnet *altifp,
388     struct in6_addr *in6)
389 {
390 	struct ifnet *ifp;
391 
392 	/* first, try to get it from the interface itself */
393 	if (in6_get_hw_ifid(ifp0, in6) == 0) {
394 		nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n",
395 		    if_name(ifp0)));
396 		goto success;
397 	}
398 
399 	/* try secondary EUI64 source. this basically is for ATM PVC */
400 	if (altifp && in6_get_hw_ifid(altifp, in6) == 0) {
401 		nd6log((LOG_DEBUG, "%s: got interface identifier from %s\n",
402 		    if_name(ifp0), if_name(altifp)));
403 		goto success;
404 	}
405 
406 	/* next, try to get it from some other hardware interface */
407 	IFNET_RLOCK_NOSLEEP();
408 	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
409 		if (ifp == ifp0)
410 			continue;
411 		if (in6_get_hw_ifid(ifp, in6) != 0)
412 			continue;
413 
414 		/*
415 		 * to borrow ifid from other interface, ifid needs to be
416 		 * globally unique
417 		 */
418 		if (IFID_UNIVERSAL(in6)) {
419 			nd6log((LOG_DEBUG,
420 			    "%s: borrow interface identifier from %s\n",
421 			    if_name(ifp0), if_name(ifp)));
422 			IFNET_RUNLOCK_NOSLEEP();
423 			goto success;
424 		}
425 	}
426 	IFNET_RUNLOCK_NOSLEEP();
427 
428 	/* last resort: get from random number source */
429 	if (get_rand_ifid(ifp, in6) == 0) {
430 		nd6log((LOG_DEBUG,
431 		    "%s: interface identifier generated by random number\n",
432 		    if_name(ifp0)));
433 		goto success;
434 	}
435 
436 	printf("%s: failed to get interface identifier\n", if_name(ifp0));
437 	return -1;
438 
439 success:
440 	nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
441 	    if_name(ifp0), in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10],
442 	    in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13],
443 	    in6->s6_addr[14], in6->s6_addr[15]));
444 	return 0;
445 }
446 
447 /*
448  * altifp - secondary EUI64 source
449  */
450 static int
451 in6_ifattach_linklocal(struct ifnet *ifp, struct ifnet *altifp)
452 {
453 	struct in6_ifaddr *ia;
454 	struct in6_aliasreq ifra;
455 	struct nd_prefixctl pr0;
456 	int error;
457 
458 	/*
459 	 * configure link-local address.
460 	 */
461 	in6_prepare_ifra(&ifra, NULL, &in6mask64);
462 
463 	ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000);
464 	ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
465 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
466 		ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
467 		ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
468 	} else {
469 		if (get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr) != 0) {
470 			nd6log((LOG_ERR,
471 			    "%s: no ifid available\n", if_name(ifp)));
472 			return (-1);
473 		}
474 	}
475 	if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL))
476 		return (-1);
477 
478 	/* link-local addresses should NEVER expire. */
479 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
480 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
481 
482 	/*
483 	 * Now call in6_update_ifa() to do a bunch of procedures to configure
484 	 * a link-local address. We can set the 3rd argument to NULL, because
485 	 * we know there's no other link-local address on the interface
486 	 * and therefore we are adding one (instead of updating one).
487 	 */
488 	if ((error = in6_update_ifa(ifp, &ifra, NULL,
489 				    IN6_IFAUPDATE_DADDELAY)) != 0) {
490 		/*
491 		 * XXX: When the interface does not support IPv6, this call
492 		 * would fail in the SIOCSIFADDR ioctl.  I believe the
493 		 * notification is rather confusing in this case, so just
494 		 * suppress it.  (jinmei@kame.net 20010130)
495 		 */
496 		if (error != EAFNOSUPPORT)
497 			nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to "
498 			    "configure a link-local address on %s "
499 			    "(errno=%d)\n",
500 			    if_name(ifp), error));
501 		return (-1);
502 	}
503 
504 	ia = in6ifa_ifpforlinklocal(ifp, 0); /* ia must not be NULL */
505 	KASSERT(ia != NULL, ("%s: ia == NULL, ifp=%p", __func__, ifp));
506 
507 	ifa_free(&ia->ia_ifa);
508 
509 	/*
510 	 * Make the link-local prefix (fe80::%link/64) as on-link.
511 	 * Since we'd like to manage prefixes separately from addresses,
512 	 * we make an ND6 prefix structure for the link-local prefix,
513 	 * and add it to the prefix list as a never-expire prefix.
514 	 * XXX: this change might affect some existing code base...
515 	 */
516 	bzero(&pr0, sizeof(pr0));
517 	pr0.ndpr_ifp = ifp;
518 	/* this should be 64 at this moment. */
519 	pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
520 	pr0.ndpr_prefix = ifra.ifra_addr;
521 	/* apply the mask for safety. (nd6_prelist_add will apply it again) */
522 	IN6_MASK_ADDR(&pr0.ndpr_prefix.sin6_addr, &in6mask64);
523 	/*
524 	 * Initialize parameters.  The link-local prefix must always be
525 	 * on-link, and its lifetimes never expire.
526 	 */
527 	pr0.ndpr_raf_onlink = 1;
528 	pr0.ndpr_raf_auto = 1;	/* probably meaningless */
529 	pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
530 	pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
531 	/*
532 	 * Since there is no other link-local addresses, nd6_prefix_lookup()
533 	 * probably returns NULL.  However, we cannot always expect the result.
534 	 * For example, if we first remove the (only) existing link-local
535 	 * address, and then reconfigure another one, the prefix is still
536 	 * valid with referring to the old link-local address.
537 	 */
538 	if (nd6_prefix_lookup(&pr0) == NULL) {
539 		if ((error = nd6_prelist_add(&pr0, NULL, NULL)) != 0)
540 			return (error);
541 	}
542 
543 	return 0;
544 }
545 
546 /*
547  * ifp - must be IFT_LOOP
548  */
549 static int
550 in6_ifattach_loopback(struct ifnet *ifp)
551 {
552 	struct in6_aliasreq ifra;
553 	int error;
554 
555 	in6_prepare_ifra(&ifra, &in6addr_loopback, &in6mask128);
556 
557 	/*
558 	 * Always initialize ia_dstaddr (= broadcast address) to loopback
559 	 * address.  Follows IPv4 practice - see in_ifinit().
560 	 */
561 	ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
562 	ifra.ifra_dstaddr.sin6_family = AF_INET6;
563 	ifra.ifra_dstaddr.sin6_addr = in6addr_loopback;
564 
565 	/* the loopback  address should NEVER expire. */
566 	ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
567 	ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
568 
569 	/*
570 	 * We are sure that this is a newly assigned address, so we can set
571 	 * NULL to the 3rd arg.
572 	 */
573 	if ((error = in6_update_ifa(ifp, &ifra, NULL, 0)) != 0) {
574 		nd6log((LOG_ERR, "in6_ifattach_loopback: failed to configure "
575 		    "the loopback address on %s (errno=%d)\n",
576 		    if_name(ifp), error));
577 		return (-1);
578 	}
579 
580 	return 0;
581 }
582 
583 /*
584  * compute NI group address, based on the current hostname setting.
585  * see RFC 4620.
586  *
587  * when ifp == NULL, the caller is responsible for filling scopeid.
588  *
589  * If oldmcprefix == 1, FF02:0:0:0:0:2::/96 is used for NI group address
590  * while it is FF02:0:0:0:0:2:FF00::/104 in RFC 4620.
591  */
592 static int
593 in6_nigroup0(struct ifnet *ifp, const char *name, int namelen,
594     struct in6_addr *in6, int oldmcprefix)
595 {
596 	struct prison *pr;
597 	const char *p;
598 	u_char *q;
599 	MD5_CTX ctxt;
600 	u_int8_t digest[16];
601 	char l;
602 	char n[64];	/* a single label must not exceed 63 chars */
603 
604 	/*
605 	 * If no name is given and namelen is -1,
606 	 * we try to do the hostname lookup ourselves.
607 	 */
608 	if (!name && namelen == -1) {
609 		pr = curthread->td_ucred->cr_prison;
610 		mtx_lock(&pr->pr_mtx);
611 		name = pr->pr_hostname;
612 		namelen = strlen(name);
613 	} else
614 		pr = NULL;
615 	if (!name || !namelen) {
616 		if (pr != NULL)
617 			mtx_unlock(&pr->pr_mtx);
618 		return -1;
619 	}
620 
621 	p = name;
622 	while (p && *p && *p != '.' && p - name < namelen)
623 		p++;
624 	if (p == name || p - name > sizeof(n) - 1) {
625 		if (pr != NULL)
626 			mtx_unlock(&pr->pr_mtx);
627 		return -1;	/* label too long */
628 	}
629 	l = p - name;
630 	strncpy(n, name, l);
631 	if (pr != NULL)
632 		mtx_unlock(&pr->pr_mtx);
633 	n[(int)l] = '\0';
634 	for (q = n; *q; q++) {
635 		if ('A' <= *q && *q <= 'Z')
636 			*q = *q - 'A' + 'a';
637 	}
638 
639 	/* generate 16 bytes of pseudo-random value. */
640 	bzero(&ctxt, sizeof(ctxt));
641 	MD5Init(&ctxt);
642 	MD5Update(&ctxt, &l, sizeof(l));
643 	MD5Update(&ctxt, n, l);
644 	MD5Final(digest, &ctxt);
645 
646 	bzero(in6, sizeof(*in6));
647 	in6->s6_addr16[0] = IPV6_ADDR_INT16_MLL;
648 	in6->s6_addr8[11] = 2;
649 	if (oldmcprefix == 0) {
650 		in6->s6_addr8[12] = 0xff;
651 	 	/* Copy the first 24 bits of 128-bit hash into the address. */
652 		bcopy(digest, &in6->s6_addr8[13], 3);
653 	} else {
654 	 	/* Copy the first 32 bits of 128-bit hash into the address. */
655 		bcopy(digest, &in6->s6_addr32[3], sizeof(in6->s6_addr32[3]));
656 	}
657 	if (in6_setscope(in6, ifp, NULL))
658 		return (-1); /* XXX: should not fail */
659 
660 	return 0;
661 }
662 
663 int
664 in6_nigroup(struct ifnet *ifp, const char *name, int namelen,
665     struct in6_addr *in6)
666 {
667 
668 	return (in6_nigroup0(ifp, name, namelen, in6, 0));
669 }
670 
671 int
672 in6_nigroup_oldmcprefix(struct ifnet *ifp, const char *name, int namelen,
673     struct in6_addr *in6)
674 {
675 
676 	return (in6_nigroup0(ifp, name, namelen, in6, 1));
677 }
678 
679 /*
680  * XXX multiple loopback interface needs more care.  for instance,
681  * nodelocal address needs to be configured onto only one of them.
682  * XXX multiple link-local address case
683  *
684  * altifp - secondary EUI64 source
685  */
686 void
687 in6_ifattach(struct ifnet *ifp, struct ifnet *altifp)
688 {
689 	struct in6_ifaddr *ia;
690 	struct in6_addr in6;
691 
692 	if (ifp->if_afdata[AF_INET6] == NULL)
693 		return;
694 	/*
695 	 * quirks based on interface type
696 	 */
697 	switch (ifp->if_type) {
698 	case IFT_STF:
699 		/*
700 		 * 6to4 interface is a very special kind of beast.
701 		 * no multicast, no linklocal.  RFC2529 specifies how to make
702 		 * linklocals for 6to4 interface, but there's no use and
703 		 * it is rather harmful to have one.
704 		 */
705 		ND_IFINFO(ifp)->flags &= ~ND6_IFF_AUTO_LINKLOCAL;
706 		break;
707 	default:
708 		break;
709 	}
710 
711 	/*
712 	 * usually, we require multicast capability to the interface
713 	 */
714 	if ((ifp->if_flags & IFF_MULTICAST) == 0) {
715 		nd6log((LOG_INFO, "in6_ifattach: "
716 		    "%s is not multicast capable, IPv6 not enabled\n",
717 		    if_name(ifp)));
718 		return;
719 	}
720 
721 	/*
722 	 * assign loopback address for loopback interface.
723 	 * XXX multiple loopback interface case.
724 	 */
725 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
726 		struct ifaddr *ifa;
727 
728 		in6 = in6addr_loopback;
729 		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &in6);
730 		if (ifa == NULL) {
731 			if (in6_ifattach_loopback(ifp) != 0)
732 				return;
733 		} else
734 			ifa_free(ifa);
735 	}
736 
737 	/*
738 	 * assign a link-local address, if there's none.
739 	 */
740 	if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
741 	    ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL) {
742 		int error;
743 
744 		ia = in6ifa_ifpforlinklocal(ifp, 0);
745 		if (ia == NULL) {
746 			error = in6_ifattach_linklocal(ifp, altifp);
747 #if 0
748 			if (error)
749 				log(LOG_NOTICE, "in6_ifattach_linklocal: "
750 				    "failed to add a link-local addr to %s\n",
751 				    if_name(ifp));
752 #endif
753 		} else
754 			ifa_free(&ia->ia_ifa);
755 	}
756 
757 	/* update dynamically. */
758 	if (V_in6_maxmtu < ifp->if_mtu)
759 		V_in6_maxmtu = ifp->if_mtu;
760 }
761 
762 /*
763  * NOTE: in6_ifdetach() does not support loopback if at this moment.
764  * We don't need this function in bsdi, because interfaces are never removed
765  * from the ifnet list in bsdi.
766  */
767 void
768 in6_ifdetach(struct ifnet *ifp)
769 {
770 	struct ifaddr *ifa, *next;
771 
772 	if (ifp->if_afdata[AF_INET6] == NULL)
773 		return;
774 
775 	/* remove neighbor management table */
776 	nd6_purge(ifp);
777 
778 	/*
779 	 * nuke any of IPv6 addresses we have
780 	 * XXX: all addresses should be already removed
781 	 */
782 	TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
783 		if (ifa->ifa_addr->sa_family != AF_INET6)
784 			continue;
785 		in6_purgeaddr(ifa);
786 	}
787 	in6_pcbpurgeif0(&V_udbinfo, ifp);
788 	in6_pcbpurgeif0(&V_ulitecbinfo, ifp);
789 	in6_pcbpurgeif0(&V_ripcbinfo, ifp);
790 	/* leave from all multicast groups joined */
791 	in6_purgemaddrs(ifp);
792 
793 	/*
794 	 * remove neighbor management table.  we call it twice just to make
795 	 * sure we nuke everything.  maybe we need just one call.
796 	 * XXX: since the first call did not release addresses, some prefixes
797 	 * might remain.  We should call nd6_purge() again to release the
798 	 * prefixes after removing all addresses above.
799 	 * (Or can we just delay calling nd6_purge until at this point?)
800 	 */
801 	nd6_purge(ifp);
802 }
803 
804 int
805 in6_get_tmpifid(struct ifnet *ifp, u_int8_t *retbuf,
806     const u_int8_t *baseid, int generate)
807 {
808 	u_int8_t nullbuf[8];
809 	struct nd_ifinfo *ndi = ND_IFINFO(ifp);
810 
811 	bzero(nullbuf, sizeof(nullbuf));
812 	if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
813 		/* we've never created a random ID.  Create a new one. */
814 		generate = 1;
815 	}
816 
817 	if (generate) {
818 		bcopy(baseid, ndi->randomseed1, sizeof(ndi->randomseed1));
819 
820 		/* generate_tmp_ifid will update seedn and buf */
821 		(void)generate_tmp_ifid(ndi->randomseed0, ndi->randomseed1,
822 		    ndi->randomid);
823 	}
824 	bcopy(ndi->randomid, retbuf, 8);
825 
826 	return (0);
827 }
828 
829 void
830 in6_tmpaddrtimer(void *arg)
831 {
832 	CURVNET_SET((struct vnet *) arg);
833 	struct nd_ifinfo *ndi;
834 	u_int8_t nullbuf[8];
835 	struct ifnet *ifp;
836 
837 	callout_reset(&V_in6_tmpaddrtimer_ch,
838 	    (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
839 	    V_ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, curvnet);
840 
841 	bzero(nullbuf, sizeof(nullbuf));
842 	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
843 		if (ifp->if_afdata[AF_INET6] == NULL)
844 			continue;
845 		ndi = ND_IFINFO(ifp);
846 		if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
847 			/*
848 			 * We've been generating a random ID on this interface.
849 			 * Create a new one.
850 			 */
851 			(void)generate_tmp_ifid(ndi->randomseed0,
852 			    ndi->randomseed1, ndi->randomid);
853 		}
854 	}
855 
856 	CURVNET_RESTORE();
857 }
858 
859 static void
860 in6_purgemaddrs(struct ifnet *ifp)
861 {
862 	LIST_HEAD(,in6_multi)	 purgeinms;
863 	struct in6_multi	*inm, *tinm;
864 	struct ifmultiaddr	*ifma;
865 
866 	LIST_INIT(&purgeinms);
867 	IN6_MULTI_LOCK();
868 
869 	/*
870 	 * Extract list of in6_multi associated with the detaching ifp
871 	 * which the PF_INET6 layer is about to release.
872 	 * We need to do this as IF_ADDR_LOCK() may be re-acquired
873 	 * by code further down.
874 	 */
875 	IF_ADDR_RLOCK(ifp);
876 	TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
877 		if (ifma->ifma_addr->sa_family != AF_INET6 ||
878 		    ifma->ifma_protospec == NULL)
879 			continue;
880 		inm = (struct in6_multi *)ifma->ifma_protospec;
881 		LIST_INSERT_HEAD(&purgeinms, inm, in6m_entry);
882 	}
883 	IF_ADDR_RUNLOCK(ifp);
884 
885 	LIST_FOREACH_SAFE(inm, &purgeinms, in6m_entry, tinm) {
886 		LIST_REMOVE(inm, in6m_entry);
887 		in6m_release_locked(inm);
888 	}
889 	mld_ifdetach(ifp);
890 
891 	IN6_MULTI_UNLOCK();
892 }
893