1 /*
2 * Copyright (c) 2003-2021 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29 /*
30 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
31 * All rights reserved.
32 *
33 * Redistribution and use in source and binary forms, with or without
34 * modification, are permitted provided that the following conditions
35 * are met:
36 * 1. Redistributions of source code must retain the above copyright
37 * notice, this list of conditions and the following disclaimer.
38 * 2. Redistributions in binary form must reproduce the above copyright
39 * notice, this list of conditions and the following disclaimer in the
40 * documentation and/or other materials provided with the distribution.
41 * 3. Neither the name of the project nor the names of its contributors
42 * may be used to endorse or promote products derived from this software
43 * without specific prior written permission.
44 *
45 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
46 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
48 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
49 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
50 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
51 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
52 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
53 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
54 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
55 * SUCH DAMAGE.
56 */
57
58 #include <sys/param.h>
59 #include <sys/systm.h>
60 #include <sys/malloc.h>
61 #include <sys/socket.h>
62 #include <sys/socketvar.h>
63 #include <sys/sockio.h>
64 #include <sys/kernel.h>
65 #include <sys/syslog.h>
66 #include <libkern/crypto/sha2.h>
67 #include <libkern/OSAtomic.h>
68 #include <kern/locks.h>
69
70 #include <net/if.h>
71 #include <net/if_dl.h>
72 #include <net/if_types.h>
73 #include <net/route.h>
74 #include <net/kpi_protocol.h>
75
76 #include <netinet/in.h>
77 #include <netinet/in_var.h>
78 #include <netinet/if_ether.h>
79 #include <netinet/in_pcb.h>
80 #include <netinet/icmp6.h>
81
82 #include <netinet/ip6.h>
83 #include <netinet6/ip6_var.h>
84 #include <netinet6/in6_var.h>
85 #include <netinet6/in6_pcb.h>
86 #include <netinet6/in6_ifattach.h>
87 #include <netinet6/ip6_var.h>
88 #include <netinet6/nd6.h>
89 #include <netinet6/scope6_var.h>
90
91 #include <net/net_osdep.h>
92 #include <dev/random/randomdev.h>
93
94 #include <net/sockaddr_utils.h>
95
96 u_int32_t in6_maxmtu = 0;
97
98 #if IP6_AUTO_LINKLOCAL
99 int ip6_auto_linklocal = IP6_AUTO_LINKLOCAL;
100 #else
101 int ip6_auto_linklocal = 1; /* enable by default */
102 #endif
103
104 extern struct inpcbinfo udbinfo;
105 extern struct inpcbinfo ripcbinfo;
106
107 static int get_rand_iid(struct ifnet *, struct in6_addr *);
108 static int in6_generate_tmp_iid(u_int8_t *, const u_int8_t *, u_int8_t *);
109 static int in6_select_iid_from_all_hw(struct ifnet *, struct ifnet *,
110 struct in6_addr *);
111 static int in6_ifattach_linklocal(struct ifnet *, struct in6_aliasreq *);
112 static int in6_ifattach_loopback(struct ifnet *);
113
114 /*
115 * Generate a last-resort interface identifier, when the machine has no
116 * IEEE802/EUI64 address sources.
117 * The goal here is to get an interface identifier that is
118 * (1) random enough and (2) does not change across reboot.
119 * We currently use SHA256(hostname) for it.
120 *
121 * in6 - upper 64bits are preserved
122 */
123 static int
get_rand_iid(__unused struct ifnet * ifp,struct in6_addr * in6)124 get_rand_iid(
125 __unused struct ifnet *ifp,
126 struct in6_addr *in6) /* upper 64bits are preserved */
127 {
128 SHA256_CTX ctxt;
129 u_int8_t digest[SHA256_DIGEST_LENGTH];
130 size_t hostnlen;
131
132 /* generate 8 bytes of pseudo-random value. */
133 bzero(&ctxt, sizeof(ctxt));
134 SHA256_Init(&ctxt);
135 lck_mtx_lock(&hostname_lock);
136 hostnlen = strlen(hostname);
137 SHA256_Update(&ctxt, hostname, hostnlen);
138 lck_mtx_unlock(&hostname_lock);
139 SHA256_Final(digest, &ctxt);
140
141 /* assumes sizeof (digest) > sizeof (iid) */
142 bcopy(digest, &in6->s6_addr[8], 8);
143
144 /* make sure to set "u" bit to local, and "g" bit to individual. */
145 in6->s6_addr[8] &= ~ND6_EUI64_GBIT; /* g bit to "individual" */
146 in6->s6_addr[8] |= ND6_EUI64_UBIT; /* u bit to "local" */
147
148 /* convert EUI64 into IPv6 interface identifier */
149 ND6_EUI64_TO_IFID(in6);
150
151 return 0;
152 }
153
154 static int
in6_generate_tmp_iid(u_int8_t * seed0,const u_int8_t * seed1,u_int8_t * ret)155 in6_generate_tmp_iid(
156 u_int8_t *seed0,
157 const u_int8_t *seed1,
158 u_int8_t *ret)
159 {
160 SHA256_CTX ctxt;
161 u_int8_t seed[16], nullbuf[8], digest[SHA256_DIGEST_LENGTH];
162 u_int32_t val32;
163 struct timeval tv;
164
165 /* If there's no history, start with a random seed. */
166 bzero(nullbuf, sizeof(nullbuf));
167 if (bcmp(nullbuf, seed0, sizeof(nullbuf)) == 0) {
168 int i;
169
170 for (i = 0; i < 2; i++) {
171 getmicrotime(&tv);
172 val32 = RandomULong() ^ tv.tv_usec;
173 bcopy(&val32, seed + sizeof(val32) * i,
174 sizeof(val32));
175 }
176 } else {
177 bcopy(seed0, seed, 8);
178 }
179
180 /* copy the right-most 64-bits of the given address */
181 /* XXX assumption on the size of IFID */
182 bcopy(seed1, &seed[8], 8);
183
184 #if DEVELOPMENT || DEBUG
185 if ((0)) { /* for debugging purposes only */
186 int i;
187
188 printf("%s: new randomized ID from: ", __func__);
189 for (i = 0; i < 16; i++) {
190 printf("%02x", seed[i]);
191 }
192 printf(" ");
193 }
194 #endif /* DEVELOPMENT || DEBUG */
195
196 /* generate 16 bytes of pseudo-random value. */
197 bzero(&ctxt, sizeof(ctxt));
198 SHA256_Init(&ctxt);
199 SHA256_Update(&ctxt, seed, sizeof(seed));
200 SHA256_Final(digest, &ctxt);
201
202 /*
203 * RFC 4941 3.2.1. (3)
204 * Take the left-most 64-bits of the SHA256 digest and set bit 6 (the
205 * left-most bit is numbered 0) to zero.
206 */
207 bcopy(digest, ret, 8);
208 ret[0] &= ~ND6_EUI64_UBIT;
209
210 /*
211 * XXX: we'd like to ensure that the generated value is not zero
212 * for simplicity. If the caclculated digest happens to be zero,
213 * use a random non-zero value as the last resort.
214 */
215 if (bcmp(nullbuf, ret, sizeof(nullbuf)) == 0) {
216 nd6log(info,
217 "%s: computed SHA256 value is zero.\n", __func__);
218
219 getmicrotime(&tv);
220 val32 = random() ^ tv.tv_usec;
221 val32 = 1 + (val32 % (0xffffffff - 1));
222 }
223
224 /*
225 * RFC 4941 3.2.1. (4)
226 * Take the next 64-bits of the SHA256 digest and save them in
227 * stable storage as the history value to be used in the next
228 * iteration of the algorithm.
229 */
230 bcopy(&digest[8], seed0, 8);
231
232 #if DEVELOPMENT || DEBUG
233 if ((0)) { /* for debugging purposes only */
234 int i;
235
236 printf("to: ");
237 for (i = 0; i < 16; i++) {
238 printf("%02x", digest[i]);
239 }
240 printf("\n");
241 }
242 #endif
243
244 return 0;
245 }
246
247 /*
248 * Get interface identifier for the specified interface using the method in
249 * Appendix A of RFC 4291.
250 *
251 * XXX assumes single sockaddr_dl (AF_LINK address) per an interface
252 *
253 * in6 - upper 64bits are preserved
254 */
255 int
in6_iid_from_hw(struct ifnet * ifp,struct in6_addr * in6)256 in6_iid_from_hw(struct ifnet *ifp, struct in6_addr *in6)
257 {
258 struct ifaddr *ifa = NULL;
259 struct sockaddr_dl *sdl;
260 u_int8_t *addr;
261 size_t addrlen;
262 static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
263 static u_int8_t allone[8] =
264 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
265 int err = -1;
266
267 /* Why doesn't this code use ifnet_addrs? */
268 ifnet_lock_shared(ifp);
269 ifa = ifp->if_lladdr;
270 sdl = SDL(ifa->ifa_addr);
271 if (sdl->sdl_alen == 0) {
272 ifnet_lock_done(ifp);
273 return -1;
274 }
275 ifa_addref(ifa); /* for this routine */
276 ifnet_lock_done(ifp);
277
278 IFA_LOCK(ifa);
279 addr = (u_int8_t *) LLADDR(sdl);
280 addrlen = sdl->sdl_alen;
281
282 /* get EUI64 */
283 switch (ifp->if_type) {
284 case IFT_ETHER:
285 case IFT_FDDI:
286 case IFT_ISO88025:
287 case IFT_ATM:
288 case IFT_IEEE1394:
289 case IFT_L2VLAN:
290 case IFT_IEEE8023ADLAG:
291 #if IFT_IEEE80211
292 case IFT_IEEE80211:
293 #endif
294 case IFT_BRIDGE:
295 /* IEEE802/EUI64 cases - what others? */
296 /* IEEE1394 uses 16byte length address starting with EUI64 */
297 if (addrlen > 8) {
298 addrlen = 8;
299 }
300
301 /* look at IEEE802/EUI64 only */
302 if (addrlen != 8 && addrlen != 6) {
303 goto done;
304 }
305
306 /*
307 * check for invalid MAC address - on bsdi, we see it a lot
308 * since wildboar configures all-zero MAC on pccard before
309 * card insertion.
310 */
311 if (bcmp(addr, allzero, addrlen) == 0) {
312 goto done;
313 }
314 if (bcmp(addr, allone, addrlen) == 0) {
315 goto done;
316 }
317
318 /* make EUI64 address */
319 if (addrlen == 8) {
320 bcopy(addr, &in6->s6_addr[8], 8);
321 } else if (addrlen == 6) {
322 in6->s6_addr[8] = addr[0];
323 in6->s6_addr[9] = addr[1];
324 in6->s6_addr[10] = addr[2];
325 in6->s6_addr[11] = 0xff;
326 in6->s6_addr[12] = 0xfe;
327 in6->s6_addr[13] = addr[3];
328 in6->s6_addr[14] = addr[4];
329 in6->s6_addr[15] = addr[5];
330 }
331 break;
332
333 case IFT_ARCNET:
334 if (addrlen != 1) {
335 goto done;
336 }
337 if (!addr[0]) {
338 goto done;
339 }
340
341 bzero(&in6->s6_addr[8], 8);
342 in6->s6_addr[15] = addr[0];
343
344 /*
345 * due to insufficient bitwidth, we mark it local.
346 */
347 in6->s6_addr[8] &= ~ND6_EUI64_GBIT; /* g to "individual" */
348 in6->s6_addr[8] |= ND6_EUI64_UBIT; /* u to "local" */
349 break;
350
351 case IFT_GIF:
352 #if IFT_STF
353 case IFT_STF:
354 #endif
355 /*
356 * RFC2893 says: "SHOULD use IPv4 address as IID source".
357 * however, IPv4 address is not very suitable as unique
358 * identifier source (can be renumbered).
359 * we don't do this.
360 */
361 goto done;
362
363 case IFT_CELLULAR:
364 goto done;
365
366 default:
367 goto done;
368 }
369
370 /* sanity check: g bit must not indicate "group" */
371 if (ND6_EUI64_GROUP(in6)) {
372 goto done;
373 }
374
375 /* convert EUI64 into IPv6 interface identifier */
376 ND6_EUI64_TO_IFID(in6);
377
378 /*
379 * sanity check: iid must not be all zero, avoid conflict with
380 * subnet router anycast
381 */
382 if ((in6->s6_addr[8] & ~(ND6_EUI64_GBIT | ND6_EUI64_UBIT)) == 0x00 &&
383 bcmp(&in6->s6_addr[9], allzero, 7) == 0) {
384 goto done;
385 }
386
387 err = 0; /* found */
388
389 done:
390 IFA_UNLOCK(ifa);
391 ifa_remref(ifa);
392 return err;
393 }
394
395 /*
396 * Get interface identifier for the specified interface using the method in
397 * Appendix A of RFC 4291. If it is not available on ifp0, borrow interface
398 * identifier from other information sources.
399 *
400 * ifp - primary EUI64 source
401 * altifp - secondary EUI64 source
402 * in6 - IPv6 address to output IID
403 */
404 static int
in6_select_iid_from_all_hw(struct ifnet * ifp0,struct ifnet * altifp,struct in6_addr * in6)405 in6_select_iid_from_all_hw(
406 struct ifnet *ifp0,
407 struct ifnet *altifp, /* secondary EUI64 source */
408 struct in6_addr *in6)
409 {
410 struct ifnet *ifp;
411
412 /* first, try to get it from the interface itself */
413 if (in6_iid_from_hw(ifp0, in6) == 0) {
414 nd6log(debug, "%s: IID derived from HW interface.\n",
415 if_name(ifp0));
416 goto success;
417 }
418
419 /* try secondary EUI64 source. this basically is for ATM PVC */
420 if (altifp && in6_iid_from_hw(altifp, in6) == 0) {
421 nd6log(debug, "%s: IID from alterate HW interface %s.\n",
422 if_name(ifp0), if_name(altifp));
423 goto success;
424 }
425
426 /* next, try to get it from some other hardware interface */
427 ifnet_head_lock_shared();
428 TAILQ_FOREACH(ifp, &ifnet_head, if_list) {
429 if (ifp == ifp0) {
430 continue;
431 }
432 if (in6_iid_from_hw(ifp, in6) != 0) {
433 continue;
434 }
435
436 /*
437 * to borrow IID from other interface, IID needs to be
438 * globally unique
439 */
440 if (ND6_IFID_UNIVERSAL(in6)) {
441 nd6log(debug, "%s: borrowed IID from %s\n",
442 if_name(ifp0), if_name(ifp));
443 ifnet_head_done();
444 goto success;
445 }
446 }
447 ifnet_head_done();
448
449 /* last resort: get from random number source */
450 if (get_rand_iid(ifp, in6) == 0) {
451 nd6log(debug, "%s: IID from PRNG.\n", if_name(ifp0));
452 goto success;
453 }
454
455 printf("%s: failed to get interface identifier\n", if_name(ifp0));
456 return -1;
457
458 success:
459 nd6log(info, "%s: IID: "
460 "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
461 if_name(ifp0),
462 in6->s6_addr[8], in6->s6_addr[9],
463 in6->s6_addr[10], in6->s6_addr[11],
464 in6->s6_addr[12], in6->s6_addr[13],
465 in6->s6_addr[14], in6->s6_addr[15]);
466 return 0;
467 }
468
469 static int
in6_ifattach_linklocal(struct ifnet * ifp,struct in6_aliasreq * ifra)470 in6_ifattach_linklocal(struct ifnet *ifp, struct in6_aliasreq *ifra)
471 {
472 struct in6_ifaddr *ia;
473 struct nd_prefix pr0, *pr;
474 int i, error;
475
476 VERIFY(ifra != NULL);
477
478 proto_plumb(PF_INET6, ifp);
479
480 error = in6_update_ifa(ifp, ifra, IN6_IFAUPDATE_DADDELAY, &ia);
481 if (error != 0) {
482 /*
483 * XXX: When the interface does not support IPv6, this call
484 * would fail in the SIOCSIFADDR ioctl. I believe the
485 * notification is rather confusing in this case, so just
486 * suppress it. ([email protected] 20010130)
487 */
488 if (error != EAFNOSUPPORT) {
489 nd6log(info, "%s: failed to "
490 "configure a link-local address on %s "
491 "(errno=%d)\n",
492 __func__, if_name(ifp), error);
493 }
494 return EADDRNOTAVAIL;
495 }
496 VERIFY(ia != NULL);
497
498 /*
499 * Make the link-local prefix (fe80::%link/64) as on-link.
500 * Since we'd like to manage prefixes separately from addresses,
501 * we make an ND6 prefix structure for the link-local prefix,
502 * and add it to the prefix list as a never-expire prefix.
503 * XXX: this change might affect some existing code base...
504 */
505 bzero(&pr0, sizeof(pr0));
506 lck_mtx_init(&pr0.ndpr_lock, &ifa_mtx_grp, &ifa_mtx_attr);
507 pr0.ndpr_ifp = ifp;
508 /* this should be 64 at this moment. */
509 pr0.ndpr_plen = (u_char)in6_mask2len(&ifra->ifra_prefixmask.sin6_addr, NULL);
510 pr0.ndpr_mask = ifra->ifra_prefixmask.sin6_addr;
511 pr0.ndpr_prefix = ifra->ifra_addr;
512 /* apply the mask for safety. (nd6_prelist_add will apply it again) */
513 for (i = 0; i < 4; i++) {
514 pr0.ndpr_prefix.sin6_addr.s6_addr32[i] &=
515 in6mask64.s6_addr32[i];
516 }
517 /*
518 * Initialize parameters. The link-local prefix must always be
519 * on-link, and its lifetimes never expire.
520 */
521 pr0.ndpr_raf_onlink = 1;
522 pr0.ndpr_raf_auto = 1; /* probably meaningless */
523 pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
524 pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
525 pr0.ndpr_stateflags |= NDPRF_STATIC;
526 /*
527 * Since there is no other link-local addresses, nd6_prefix_lookup()
528 * probably returns NULL. However, we cannot always expect the result.
529 * For example, if we first remove the (only) existing link-local
530 * address, and then reconfigure another one, the prefix is still
531 * valid with referring to the old link-local address.
532 */
533 if ((pr = nd6_prefix_lookup(&pr0, ND6_PREFIX_EXPIRY_UNSPEC)) == NULL) {
534 if ((error = nd6_prelist_add(&pr0, NULL, &pr, TRUE)) != 0) {
535 ifa_remref(&ia->ia_ifa);
536 lck_mtx_destroy(&pr0.ndpr_lock, &ifa_mtx_grp);
537 return error;
538 }
539 }
540
541 in6_post_msg(ifp, KEV_INET6_NEW_LL_ADDR, ia, NULL);
542 ifa_remref(&ia->ia_ifa);
543
544 /* Drop use count held above during lookup/add */
545 if (pr != NULL) {
546 NDPR_REMREF(pr);
547 }
548
549 lck_mtx_destroy(&pr0.ndpr_lock, &ifa_mtx_grp);
550 return 0;
551 }
552
553 static int
in6_ifattach_loopback(struct ifnet * ifp)554 in6_ifattach_loopback(
555 struct ifnet *ifp) /* must be IFT_LOOP */
556 {
557 struct in6_aliasreq ifra;
558 struct in6_ifaddr *ia;
559 int error;
560
561 bzero(&ifra, sizeof(ifra));
562
563 /*
564 * in6_update_ifa() does not use ifra_name, but we accurately set it
565 * for safety.
566 */
567 strlcpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
568
569 ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
570 ifra.ifra_prefixmask.sin6_family = AF_INET6;
571 ifra.ifra_prefixmask.sin6_addr = in6mask128;
572
573 /*
574 * Always initialize ia_dstaddr (= broadcast address) to loopback
575 * address. Follows IPv4 practice - see in_ifinit().
576 */
577 ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
578 ifra.ifra_dstaddr.sin6_family = AF_INET6;
579 ifra.ifra_dstaddr.sin6_addr = in6addr_loopback;
580
581 ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
582 ifra.ifra_addr.sin6_family = AF_INET6;
583 ifra.ifra_addr.sin6_addr = in6addr_loopback;
584
585 /* the loopback address should NEVER expire. */
586 ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
587 ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
588
589 /* we don't need to perform DAD on loopback interfaces. */
590 ifra.ifra_flags |= IN6_IFF_NODAD;
591
592 /* add the new interface address */
593 error = in6_update_ifa(ifp, &ifra, 0, &ia);
594 if (error != 0) {
595 nd6log(error,
596 "%s: failed to configure loopback address %s (error=%d)\n",
597 __func__, if_name(ifp), error);
598 VERIFY(ia == NULL);
599 return EADDRNOTAVAIL;
600 }
601
602 VERIFY(ia != NULL);
603 ifa_remref(&ia->ia_ifa);
604 return 0;
605 }
606
607 /*
608 * compute NI group address, based on the current hostname setting.
609 * see RFC 4620.
610 *
611 * when ifp == NULL, the caller is responsible for filling scopeid.
612 */
613 int
in6_nigroup(struct ifnet * ifp,const char * name,size_t namelen,struct in6_addr * in6,uint32_t * ifscopep)614 in6_nigroup(
615 struct ifnet *ifp,
616 const char *name,
617 size_t namelen,
618 struct in6_addr *in6,
619 uint32_t *ifscopep)
620 {
621 const char *p;
622 u_char *q;
623 SHA256_CTX ctxt;
624 u_int8_t digest[SHA256_DIGEST_LENGTH];
625 size_t l;
626 char n[64]; /* a single label must not exceed 63 chars */
627
628 if (!namelen || !name) {
629 return -1;
630 }
631
632 p = name;
633 while (p && *p && *p != '.' && p - name < namelen) {
634 p++;
635 }
636 if (p - name > sizeof(n) - 1) {
637 return -1; /* label too long */
638 }
639 l = p - name;
640 strlcpy(n, name, l);
641 n[(int)l] = '\0';
642 for (q = (u_char *) n; *q; q++) {
643 if ('A' <= *q && *q <= 'Z') {
644 *q = *q - 'A' + 'a';
645 }
646 }
647
648 /* generate 16 bytes of pseudo-random value. */
649 bzero(&ctxt, sizeof(ctxt));
650 SHA256_Init(&ctxt);
651 SHA256_Update(&ctxt, &l, sizeof(l));
652 SHA256_Update(&ctxt, n, l);
653 SHA256_Final(digest, &ctxt);
654
655 bzero(in6, sizeof(*in6));
656 in6->s6_addr16[0] = IPV6_ADDR_INT16_MLL;
657 in6->s6_addr8[11] = 2;
658 in6->s6_addr8[12] = 0xff;
659 /* copy first 3 bytes of prefix into address */
660 bcopy(digest, &in6->s6_addr8[13], 3);
661 if (in6_setscope(in6, ifp, ifscopep)) {
662 return -1; /* XXX: should not fail */
663 }
664 return 0;
665 }
666
667 int
in6_domifattach(struct ifnet * ifp)668 in6_domifattach(struct ifnet *ifp)
669 {
670 int error;
671
672 VERIFY(ifp != NULL);
673
674 error = proto_plumb(PF_INET6, ifp);
675 if (error != 0) {
676 if (error != EEXIST) {
677 log(LOG_ERR, "%s: proto_plumb returned %d if=%s\n",
678 __func__, error, if_name(ifp));
679 }
680 } else {
681 error = in6_ifattach_prelim(ifp);
682 if (error != 0) {
683 int errorx;
684
685 log(LOG_ERR,
686 "%s: in6_ifattach_prelim returned %d if=%s%d\n",
687 __func__, error, ifp->if_name, ifp->if_unit);
688
689 errorx = proto_unplumb(PF_INET6, ifp);
690 if (errorx != 0) { /* XXX should not fail */
691 log(LOG_ERR,
692 "%s: proto_unplumb returned %d if=%s%d\n",
693 __func__, errorx, ifp->if_name,
694 ifp->if_unit);
695 }
696 }
697 }
698
699 return error;
700 }
701
702 int
in6_ifattach_prelim(struct ifnet * ifp)703 in6_ifattach_prelim(struct ifnet *ifp)
704 {
705 int error = 0;
706 struct in6_ifaddr *ia6 = NULL;
707
708 VERIFY(ifp != NULL);
709
710 /* quirks based on interface type */
711 switch (ifp->if_type) {
712 #if IFT_STF
713 case IFT_STF:
714 /*
715 * 6to4 interface is a very special kind of beast.
716 * no multicast, no linklocal. RFC2529 specifies how to make
717 * linklocals for 6to4 interface, but there's no use and
718 * it is rather harmful to have one.
719 */
720 goto skipmcast;
721 #endif
722 default:
723 break;
724 }
725
726 /*
727 * IPv6 requires multicast capability at the interface.
728 * (previously, this was a silent error.)
729 */
730 if ((ifp->if_flags & IFF_MULTICAST) == 0) {
731 nd6log0(info, "in6_ifattach: %s is not multicast capable, IPv6 not enabled\n",
732 if_name(ifp));
733 return EINVAL;
734 }
735
736 #if IFT_STF
737 skipmcast:
738 #endif
739
740 if (ifp->if_inet6data == NULL) {
741 ifp->if_inet6data = zalloc_permanent_type(struct in6_ifextra);
742 } else {
743 /*
744 * Since the structure is never freed, we need to zero out
745 * some of its members. We avoid zeroing out the scope6
746 * structure on purpose because other threads might be
747 * using its contents.
748 */
749 bzero(&IN6_IFEXTRA(ifp)->icmp6_ifstat,
750 sizeof(IN6_IFEXTRA(ifp)->icmp6_ifstat));
751 bzero(&IN6_IFEXTRA(ifp)->in6_ifstat,
752 sizeof(IN6_IFEXTRA(ifp)->in6_ifstat));
753 /*
754 * XXX When recycling, nd_ifinfo gets initialized, other
755 * than the lock, inside nd6_ifattach
756 */
757 }
758
759 /*
760 * XXX Only initialize IPv6 configuration for the interface
761 * if interface has not yet been configured with
762 * link local IPv6 address.
763 * Could possibly be optimized with an interface flag if need
764 * be. For now using in6ifa_ifpforlinklocal.
765 */
766 ia6 = in6ifa_ifpforlinklocal(ifp, 0);
767 if (ia6 == NULL) {
768 IN6_IFEXTRA(ifp)->netsig_len = 0;
769 bzero(&IN6_IFEXTRA(ifp)->netsig,
770 sizeof(IN6_IFEXTRA(ifp)->netsig));
771 bzero(IN6_IFEXTRA(ifp)->nat64_prefixes,
772 sizeof(IN6_IFEXTRA(ifp)->nat64_prefixes));
773 /* initialize NDP variables */
774 nd6_ifattach(ifp);
775 } else {
776 VERIFY(ND_IFINFO(ifp)->initialized);
777 ifa_remref(&ia6->ia_ifa);
778 ia6 = NULL;
779 }
780 scope6_ifattach(ifp);
781
782 /* initialize loopback interface address */
783 if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
784 error = in6_ifattach_loopback(ifp);
785 if (error != 0) {
786 log(LOG_ERR, "%s: in6_ifattach_loopback returned %d\n",
787 __func__, error);
788 return error;
789 }
790 }
791
792 /* update dynamically. */
793 if (in6_maxmtu < ifp->if_mtu) {
794 in6_maxmtu = ifp->if_mtu;
795 }
796
797 VERIFY(error == 0);
798 return 0;
799 }
800
801 /*
802 * This routine is only meant to configure IPv6 Link Local
803 * addresses.
804 */
805 int
in6_ifattach_aliasreq(struct ifnet * ifp,struct ifnet * altifp,struct in6_aliasreq * ifra0)806 in6_ifattach_aliasreq(struct ifnet *ifp, struct ifnet *altifp,
807 struct in6_aliasreq *ifra0)
808 {
809 int error;
810 struct in6_ifaddr *ia6;
811 struct in6_aliasreq ifra;
812
813 error = in6_ifattach_prelim(ifp);
814 if (error != 0) {
815 return error;
816 }
817
818 if (!ip6_auto_linklocal) {
819 return 0;
820 }
821
822 /*
823 * Assign a link-local address, only if there isn't one here already.
824 * XXX If we ever allow more than one LLA on the interface
825 * make sure that the corresponding prefix on the prefixlist
826 * is reference counted and the address's prefix pointer
827 * points to the prefix.
828 */
829 ia6 = in6ifa_ifpforlinklocal(ifp, 0);
830 if (ia6 != NULL) {
831 ifa_remref(&ia6->ia_ifa);
832 return 0;
833 }
834
835 bzero(&ifra, sizeof(ifra));
836
837 /*
838 * in6_update_ifa() does not use ifra_name, but we accurately set it
839 * for safety.
840 */
841 strlcpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
842
843 /* Initialize the IPv6 interface address in our in6_aliasreq block */
844 if (ifra0 != NULL) {
845 /* interface provided both addresses for us */
846 struct sockaddr_in6 *sin6 = &ifra.ifra_addr;
847 struct in6_addr *in6 = &sin6->sin6_addr;
848 boolean_t ok = TRUE;
849
850 SOCKADDR_COPY(&ifra0->ifra_addr, sin6, sizeof(struct sockaddr_in6));
851
852 if (sin6->sin6_family != AF_INET6 || sin6->sin6_port != 0) {
853 ok = FALSE;
854 }
855 if (ok && (in6->s6_addr16[0] != htons(0xfe80))) {
856 ok = FALSE;
857 }
858
859 if (ok) {
860 if (sin6->sin6_scope_id == 0 && in6->s6_addr16[1] == 0) {
861 if (in6_embedded_scope) {
862 in6->s6_addr16[1] = htons(ifp->if_index);
863 } else {
864 sin6->sin6_scope_id = ifp->if_index;
865 }
866 } else if (sin6->sin6_scope_id != 0 &&
867 sin6->sin6_scope_id != ifp->if_index) {
868 ok = FALSE;
869 } else if (in6_embedded_scope && in6->s6_addr16[1] != 0 &&
870 ntohs(in6->s6_addr16[1]) != ifp->if_index) {
871 ok = FALSE;
872 }
873 }
874 if (ok && (in6->s6_addr32[1] != 0)) {
875 ok = FALSE;
876 }
877 if (!ok) {
878 return EINVAL;
879 }
880 } else {
881 ifra.ifra_addr.sin6_family = AF_INET6;
882 ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
883 ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80);
884 if (in6_embedded_scope) {
885 ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
886 } else {
887 ifra.ifra_addr.sin6_addr.s6_addr16[1] = 0;
888 ifra.ifra_addr.sin6_scope_id = ifp->if_index;
889 }
890 ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
891 if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
892 ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
893 ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
894 if (!in6_embedded_scope) {
895 ifra.ifra_addr.sin6_scope_id = ifp->if_index;
896 }
897 } else {
898 if (in6_select_iid_from_all_hw(ifp, altifp,
899 &ifra.ifra_addr.sin6_addr) != 0) {
900 nd6log(error, "%s: no IID available\n",
901 if_name(ifp));
902 return EADDRNOTAVAIL;
903 }
904 }
905 }
906
907 if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, IN6_NULL_IF_EMBEDDED_SCOPE(&ifra.ifra_addr.sin6_scope_id))) {
908 return EADDRNOTAVAIL;
909 }
910
911 /* Set the prefix mask */
912 ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
913 ifra.ifra_prefixmask.sin6_family = AF_INET6;
914 ifra.ifra_prefixmask.sin6_addr = in6mask64;
915
916 /* link-local addresses should NEVER expire. */
917 ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
918 ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
919
920 /* Attach the link-local address */
921 if (in6_ifattach_linklocal(ifp, &ifra) != 0) {
922 nd6log(info,
923 "%s: %s could not attach link-local address.\n",
924 __func__, if_name(ifp));
925 /* NB: not an error */
926 }
927
928 return 0;
929 }
930
931 int
in6_ifattach_llcgareq(struct ifnet * ifp,struct in6_cgareq * llcgasr)932 in6_ifattach_llcgareq(struct ifnet *ifp, struct in6_cgareq *llcgasr)
933 {
934 struct in6_aliasreq ifra;
935 struct in6_ifaddr *ia6 = NULL;
936 struct nd_ifinfo *ndi = NULL;
937 int error;
938
939 VERIFY(llcgasr != NULL);
940
941 error = in6_ifattach_prelim(ifp);
942 if (error != 0) {
943 return error;
944 }
945
946 if (!ip6_auto_linklocal) {
947 return 0;
948 }
949
950 if (nd6_send_opstate == ND6_SEND_OPMODE_DISABLED) {
951 return ENXIO;
952 }
953
954 ndi = ND_IFINFO(ifp);
955 VERIFY(ndi != NULL && ndi->initialized);
956 if ((ndi->flags & ND6_IFF_INSECURE) != 0) {
957 return ENXIO;
958 }
959
960 /*
961 * Assign a link-local address, only if there isn't one here already.
962 * XXX If we ever allow more than one LLA on the interface
963 * make sure that the corresponding prefix on the prefixlist
964 * is reference counted and the address's prefix pointer
965 * points to the prefix.
966 */
967 ia6 = in6ifa_ifpforlinklocal(ifp, 0);
968 if (ia6 != NULL) {
969 ifa_remref(&ia6->ia_ifa);
970 return 0;
971 }
972
973 bzero(&ifra, sizeof(ifra));
974 strlcpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
975
976 ifra.ifra_addr.sin6_family = AF_INET6;
977 ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
978 ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80);
979 ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
980 ifra.ifra_flags = IN6_IFF_SECURED;
981
982 in6_cga_node_lock();
983 if (in6_cga_generate(&llcgasr->cgar_cgaprep, llcgasr->cgar_collision_count,
984 &ifra.ifra_addr.sin6_addr, ifp)) {
985 in6_cga_node_unlock();
986 return EADDRNOTAVAIL;
987 }
988 in6_cga_node_unlock();
989 if (in6_embedded_scope) {
990 ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
991 } else {
992 ifra.ifra_addr.sin6_addr.s6_addr16[1] = 0;
993 }
994
995 if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, IN6_NULL_IF_EMBEDDED_SCOPE(&ifra.ifra_addr.sin6_scope_id))) {
996 return EADDRNOTAVAIL;
997 }
998
999 /* Set the prefix mask */
1000 ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
1001 ifra.ifra_prefixmask.sin6_family = AF_INET6;
1002 ifra.ifra_prefixmask.sin6_addr = in6mask64;
1003
1004 /*
1005 * link-local addresses should NEVER expire, but cryptographic
1006 * ones may have finite preferred lifetime [if it's important to
1007 * keep them from being used by applications as persistent device
1008 * identifiers].
1009 */
1010 ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
1011 ifra.ifra_lifetime.ia6t_pltime = llcgasr->cgar_lifetime.ia6t_pltime;
1012
1013 /* Attach the link-local address */
1014 if (in6_ifattach_linklocal(ifp, &ifra) != 0) {
1015 /* NB: not an error */
1016 nd6log(info,
1017 "%s: %s could not attach link-local address.\n",
1018 __func__, if_name(ifp));
1019 }
1020
1021 VERIFY(error == 0);
1022 return error;
1023 }
1024
1025 /*
1026 * NOTE: in6_ifdetach() does not support loopback if at this moment.
1027 */
1028 void
in6_ifdetach(struct ifnet * ifp)1029 in6_ifdetach(struct ifnet *ifp)
1030 {
1031 struct in6_ifaddr *ia, *nia;
1032 struct ifaddr *ifa;
1033 struct rtentry *rt;
1034 struct sockaddr_in6 sin6;
1035 struct in6_multi_mship *imm;
1036 int unlinked;
1037
1038 LCK_MTX_ASSERT(nd6_mutex, LCK_MTX_ASSERT_NOTOWNED);
1039
1040 /* remove neighbor management table */
1041 nd6_purge(ifp);
1042
1043 /* nuke any of IPv6 addresses we have */
1044 lck_rw_lock_exclusive(&in6_ifaddr_rwlock);
1045 boolean_t from_begining = TRUE;
1046 while (from_begining) {
1047 from_begining = FALSE;
1048 TAILQ_FOREACH(ia, &in6_ifaddrhead, ia6_link) {
1049 if (ia->ia_ifa.ifa_ifp != ifp) {
1050 continue;
1051 }
1052 ifa_addref(&ia->ia_ifa); /* for us */
1053 lck_rw_done(&in6_ifaddr_rwlock);
1054 in6_purgeaddr(&ia->ia_ifa);
1055 ifa_remref(&ia->ia_ifa); /* for us */
1056 lck_rw_lock_exclusive(&in6_ifaddr_rwlock);
1057 /*
1058 * Purging the address caused in6_ifaddr_rwlock
1059 * to be dropped and reacquired;
1060 * therefore search again from the beginning
1061 * of in6_ifaddrs list.
1062 */
1063 from_begining = TRUE;
1064 break;
1065 }
1066 }
1067 lck_rw_done(&in6_ifaddr_rwlock);
1068
1069 ifnet_lock_exclusive(ifp);
1070
1071 /* undo everything done by in6_ifattach(), just in case */
1072 ifa = TAILQ_FIRST(&ifp->if_addrlist);
1073 while (ifa != NULL) {
1074 IFA_LOCK(ifa);
1075 if (ifa->ifa_addr->sa_family != AF_INET6 ||
1076 !IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa->ifa_addr)->sin6_addr)) {
1077 IFA_UNLOCK(ifa);
1078 ifa = TAILQ_NEXT(ifa, ifa_list);
1079 continue;
1080 }
1081
1082 ia = (struct in6_ifaddr *)ifa;
1083
1084 /* hold a reference for this routine */
1085 ifa_addref(ifa);
1086 /* remove from the linked list */
1087 if_detach_ifa(ifp, ifa);
1088 IFA_UNLOCK(ifa);
1089
1090 /*
1091 * Leaving the multicast group(s) may involve freeing the
1092 * link address multicast structure(s) for the interface,
1093 * which is protected by ifnet lock. To avoid violating
1094 * lock ordering, we must drop ifnet lock before doing so.
1095 * The ifa won't go away since we held a refcnt above.
1096 */
1097 ifnet_lock_done(ifp);
1098
1099 /*
1100 * We have to do this work manually here instead of calling
1101 * in6_purgeaddr() since in6_purgeaddr() uses the RTM_HOST flag.
1102 */
1103
1104 /*
1105 * leave from multicast groups we have joined for the interface
1106 */
1107 IFA_LOCK(ifa);
1108 while ((imm = ia->ia6_memberships.lh_first) != NULL) {
1109 LIST_REMOVE(imm, i6mm_chain);
1110 IFA_UNLOCK(ifa);
1111 in6_leavegroup(imm);
1112 IFA_LOCK(ifa);
1113 }
1114
1115 /* remove from the routing table */
1116 if (ia->ia_flags & IFA_ROUTE) {
1117 IFA_UNLOCK(ifa);
1118 rt = rtalloc1(SA(&ia->ia_addr), 0, 0);
1119 if (rt != NULL) {
1120 (void) rtrequest(RTM_DELETE,
1121 SA(&ia->ia_addr),
1122 SA(&ia->ia_addr),
1123 SA(&ia->ia_prefixmask),
1124 rt->rt_flags, (struct rtentry **)0);
1125 rtfree(rt);
1126 }
1127 } else {
1128 IFA_UNLOCK(ifa);
1129 }
1130
1131 /* also remove from the IPv6 address chain(itojun&jinmei) */
1132 unlinked = 0;
1133 lck_rw_lock_exclusive(&in6_ifaddr_rwlock);
1134 TAILQ_FOREACH(nia, &in6_ifaddrhead, ia6_link) {
1135 if (ia == nia) {
1136 TAILQ_REMOVE(&in6_ifaddrhead, ia, ia6_link);
1137 os_atomic_inc(&in6_ifaddrlist_genid, relaxed);
1138 unlinked = 1;
1139 break;
1140 }
1141 }
1142 lck_rw_done(&in6_ifaddr_rwlock);
1143
1144 /*
1145 * release another refcnt for the link from in6_ifaddrs.
1146 * Do this only if it's not already unlinked in the event
1147 * that we lost the race, since in6_ifaddr_rwlock was
1148 * momentarily dropped above.
1149 */
1150 if (unlinked) {
1151 ifa_remref(ifa);
1152 }
1153 /* release reference held for this routine */
1154 ifa_remref(ifa);
1155
1156 /*
1157 * This is suboptimal, but since we dropped ifnet lock above
1158 * the list might have changed. Repeat the search from the
1159 * beginning until we find the first eligible IPv6 address.
1160 */
1161 ifnet_lock_exclusive(ifp);
1162 ifa = TAILQ_FIRST(&ifp->if_addrlist);
1163 }
1164 ifnet_lock_done(ifp);
1165
1166 /* invalidate route caches */
1167 routegenid_inet6_update();
1168
1169 /*
1170 * remove neighbor management table. we call it twice just to make
1171 * sure we nuke everything. maybe we need just one call.
1172 * XXX: since the first call did not release addresses, some prefixes
1173 * might remain. We should call nd6_purge() again to release the
1174 * prefixes after removing all addresses above.
1175 * (Or can we just delay calling nd6_purge until at this point?)
1176 */
1177 nd6_purge(ifp);
1178
1179 /* remove route to link-local allnodes multicast (ff02::1) */
1180 SOCKADDR_ZERO(&sin6, sizeof(sin6));
1181 sin6.sin6_len = sizeof(struct sockaddr_in6);
1182 sin6.sin6_family = AF_INET6;
1183 sin6.sin6_addr = in6addr_linklocal_allnodes;
1184 if (in6_embedded_scope) {
1185 sin6.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
1186 } else {
1187 sin6.sin6_scope_id = ifp->if_index;
1188 }
1189 rt = rtalloc1(SA(&sin6), 0, 0);
1190 if (rt != NULL) {
1191 RT_LOCK(rt);
1192 if (rt->rt_ifp == ifp) {
1193 /*
1194 * Prevent another thread from modifying rt_key,
1195 * rt_gateway via rt_setgate() after the rt_lock
1196 * is dropped by marking the route as defunct.
1197 */
1198 rt->rt_flags |= RTF_CONDEMNED;
1199 RT_UNLOCK(rt);
1200 (void) rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway,
1201 rt_mask(rt), rt->rt_flags, 0);
1202 } else {
1203 RT_UNLOCK(rt);
1204 }
1205 rtfree(rt);
1206 }
1207 }
1208
1209 void
in6_iid_mktmp(struct ifnet * ifp,u_int8_t * retbuf,const u_int8_t * baseid,int generate)1210 in6_iid_mktmp(struct ifnet *ifp, u_int8_t *retbuf, const u_int8_t *baseid,
1211 int generate)
1212 {
1213 u_int8_t nullbuf[8];
1214 struct nd_ifinfo *ndi = ND_IFINFO(ifp);
1215
1216 VERIFY(ndi != NULL && ndi->initialized);
1217 lck_mtx_lock(&ndi->lock);
1218 bzero(nullbuf, sizeof(nullbuf));
1219 if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) == 0) {
1220 /* we've never created a random ID. Create a new one. */
1221 generate = 1;
1222 }
1223
1224 if (generate) {
1225 bcopy(baseid, ndi->randomseed1, sizeof(ndi->randomseed1));
1226
1227 /* in6_generate_tmp_iid will update seedn and buf */
1228 (void) in6_generate_tmp_iid(ndi->randomseed0, ndi->randomseed1,
1229 ndi->randomid);
1230 }
1231
1232 bcopy(ndi->randomid, retbuf, 8);
1233 lck_mtx_unlock(&ndi->lock);
1234 }
1235
1236 void
in6_tmpaddrtimer(void * arg)1237 in6_tmpaddrtimer(void *arg)
1238 {
1239 #pragma unused(arg)
1240 struct ifnet *ifp = NULL;
1241 struct nd_ifinfo *ndi = NULL;
1242 u_int8_t nullbuf[8];
1243
1244 timeout(in6_tmpaddrtimer, (caddr_t)0, (ip6_temp_preferred_lifetime -
1245 ip6_desync_factor - ip6_temp_regen_advance) * hz);
1246
1247 bzero(nullbuf, sizeof(nullbuf));
1248 ifnet_head_lock_shared();
1249 for (ifp = ifnet_head.tqh_first; ifp;
1250 ifp = ifp->if_link.tqe_next) {
1251 ndi = ND_IFINFO(ifp);
1252 if ((NULL == ndi) || (FALSE == ndi->initialized)) {
1253 continue;
1254 }
1255 lck_mtx_lock(&ndi->lock);
1256 if (bcmp(ndi->randomid, nullbuf, sizeof(nullbuf)) != 0) {
1257 /*
1258 * We've been generating a random ID on this interface.
1259 * Create a new one.
1260 */
1261 (void) in6_generate_tmp_iid(ndi->randomseed0,
1262 ndi->randomseed1, ndi->randomid);
1263 }
1264 lck_mtx_unlock(&ndi->lock);
1265 }
1266 ifnet_head_done();
1267 }
1268