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/param.h>
35 #include <sys/eventhandler.h>
36 #include <sys/systm.h>
37 #include <sys/counter.h>
38 #include <sys/malloc.h>
39 #include <sys/socket.h>
40 #include <sys/sockio.h>
41 #include <sys/jail.h>
42 #include <sys/kernel.h>
43 #include <sys/lock.h>
44 #include <sys/proc.h>
45 #include <sys/rmlock.h>
46 #include <sys/syslog.h>
47 #include <sys/md5.h>
48
49 #include <net/if.h>
50 #include <net/if_var.h>
51 #include <net/if_dl.h>
52 #include <net/if_private.h>
53 #include <net/if_types.h>
54 #include <net/if_llatbl.h>
55 #include <net/route.h>
56 #include <net/vnet.h>
57
58 #include <netinet/in.h>
59 #include <netinet/in_var.h>
60 #include <netinet/if_ether.h>
61 #include <netinet/in_pcb.h>
62 #include <netinet/ip_var.h>
63 #include <netinet/udp.h>
64 #include <netinet/udp_var.h>
65
66 #include <netinet/ip6.h>
67 #include <netinet6/ip6_var.h>
68 #include <netinet6/in6_var.h>
69 #include <netinet6/in6_pcb.h>
70 #include <netinet6/in6_ifattach.h>
71 #include <netinet6/ip6_var.h>
72 #include <netinet6/nd6.h>
73 #include <netinet6/mld6_var.h>
74 #include <netinet6/scope6_var.h>
75
76 #include <crypto/sha2/sha256.h>
77 #include <machine/atomic.h>
78
79 #ifdef IP6_AUTO_LINKLOCAL
80 VNET_DEFINE(int, ip6_auto_linklocal) = IP6_AUTO_LINKLOCAL;
81 #else
82 VNET_DEFINE(int, ip6_auto_linklocal) = 1; /* enabled by default */
83 #endif
84
85 VNET_DEFINE(struct callout, in6_tmpaddrtimer_ch);
86 #define V_in6_tmpaddrtimer_ch VNET(in6_tmpaddrtimer_ch)
87
88 VNET_DEFINE(int, ip6_stableaddr_netifsource) = IP6_STABLEADDR_NETIFSRC_NAME; /* Use interface name by default */
89
90 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
91 #define V_ripcbinfo VNET(ripcbinfo)
92
93 static int get_rand_ifid(struct ifnet *, struct in6_addr *);
94 static int in6_ifattach_linklocal(struct ifnet *, struct ifnet *);
95 static int in6_ifattach_loopback(struct ifnet *);
96 static void in6_purgemaddrs(struct ifnet *);
97
98 #define EUI64_GBIT 0x01
99 #define EUI64_UBIT 0x02
100 #define EUI64_TO_IFID(in6) do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (0)
101 #define EUI64_GROUP(in6) ((in6)->s6_addr[8] & EUI64_GBIT)
102 #define EUI64_INDIVIDUAL(in6) (!EUI64_GROUP(in6))
103 #define EUI64_LOCAL(in6) ((in6)->s6_addr[8] & EUI64_UBIT)
104 #define EUI64_UNIVERSAL(in6) (!EUI64_LOCAL(in6))
105
106 #define IFID_LOCAL(in6) (!EUI64_LOCAL(in6))
107 #define IFID_UNIVERSAL(in6) (!EUI64_UNIVERSAL(in6))
108
109 #define HMAC_IPAD 0x36
110 #define HMAC_OPAD 0x5C
111
112 /*
113 * Generate a last-resort interface identifier, when the machine has no
114 * IEEE802/EUI64 address sources.
115 * The goal here is to get an interface identifier that is
116 * (1) random enough and (2) does not change across reboot.
117 * We currently use MD5(hostname) for it.
118 *
119 * in6 - upper 64bits are preserved
120 */
121 static int
get_rand_ifid(struct ifnet * ifp,struct in6_addr * in6)122 get_rand_ifid(struct ifnet *ifp, struct in6_addr *in6)
123 {
124 MD5_CTX ctxt;
125 struct prison *pr;
126 u_int8_t digest[16];
127 int hostnamelen;
128
129 pr = curthread->td_ucred->cr_prison;
130 mtx_lock(&pr->pr_mtx);
131 hostnamelen = strlen(pr->pr_hostname);
132 #if 0
133 /* we need at least several letters as seed for ifid */
134 if (hostnamelen < 3) {
135 mtx_unlock(&pr->pr_mtx);
136 return -1;
137 }
138 #endif
139
140 /* generate 8 bytes of pseudo-random value. */
141 bzero(&ctxt, sizeof(ctxt));
142 MD5Init(&ctxt);
143 MD5Update(&ctxt, pr->pr_hostname, hostnamelen);
144 mtx_unlock(&pr->pr_mtx);
145 MD5Final(digest, &ctxt);
146
147 /* assumes sizeof(digest) > sizeof(ifid) */
148 bcopy(digest, &in6->s6_addr[8], 8);
149
150 /* make sure to set "u" bit to local, and "g" bit to individual. */
151 in6->s6_addr[8] &= ~EUI64_GBIT; /* g bit to "individual" */
152 in6->s6_addr[8] |= EUI64_UBIT; /* u bit to "local" */
153
154 /* convert EUI64 into IPv6 interface identifier */
155 EUI64_TO_IFID(in6);
156
157 return 0;
158 }
159
160
161 /*
162 * Get interface link level sockaddr
163 */
164 static struct sockaddr_dl *
get_interface_link_level(struct ifnet * ifp)165 get_interface_link_level(struct ifnet *ifp)
166 {
167 struct ifaddr *ifa;
168 struct sockaddr_dl *sdl;
169
170 NET_EPOCH_ASSERT();
171
172 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
173 if (ifa->ifa_addr->sa_family != AF_LINK)
174 continue;
175 sdl = (struct sockaddr_dl *)ifa->ifa_addr;
176 if (sdl == NULL)
177 continue;
178 if (sdl->sdl_alen == 0)
179 continue;
180
181 return (sdl);
182 }
183
184 return (NULL);
185 }
186
187 /*
188 * Get hwaddr from link interface
189 */
190 static uint8_t *
in6_get_interface_hwaddr(struct ifnet * ifp,size_t * len)191 in6_get_interface_hwaddr(struct ifnet *ifp, size_t *len)
192 {
193 struct sockaddr_dl *sdl;
194 u_int8_t *addr;
195 static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
196 static u_int8_t allone[8] =
197 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
198
199 sdl = get_interface_link_level(ifp);
200 if (sdl == NULL)
201 return (NULL);
202
203 addr = LLADDR(sdl);
204 *len = sdl->sdl_alen;
205
206 /* get EUI64 */
207 switch (ifp->if_type) {
208 case IFT_BRIDGE:
209 case IFT_ETHER:
210 case IFT_L2VLAN:
211 case IFT_ATM:
212 case IFT_IEEE1394:
213 /* IEEE802/EUI64 cases - what others? */
214 /* IEEE1394 uses 16byte length address starting with EUI64 */
215 if (*len > 8)
216 *len = 8;
217
218 /* look at IEEE802/EUI64 only */
219 if (*len != 8 && *len != 6)
220 return (NULL);
221
222 /*
223 * check for invalid MAC address - on bsdi, we see it a lot
224 * since wildboar configures all-zero MAC on pccard before
225 * card insertion.
226 */
227 if (memcmp(addr, allzero, *len) == 0 || memcmp(addr, allone, *len) == 0)
228 return (NULL);
229
230 break;
231
232 case IFT_GIF:
233 case IFT_STF:
234 /*
235 * RFC2893 says: "SHOULD use IPv4 address as ifid source".
236 * however, IPv4 address is not very suitable as unique
237 * identifier source (can be renumbered).
238 * we don't do this.
239 */
240 return (NULL);
241
242 case IFT_INFINIBAND:
243 if (*len != 20)
244 return (NULL);
245 *len = 8;
246 addr += 12;
247 break;
248
249 default:
250 return (NULL);
251 }
252
253 return (addr);
254 }
255
256 /*
257 * Get interface identifier for the specified interface.
258 * XXX assumes single sockaddr_dl (AF_LINK address) per an interface
259 *
260 * in6 - upper 64bits are preserved
261 */
262 int
in6_get_hw_ifid(struct ifnet * ifp,struct in6_addr * in6)263 in6_get_hw_ifid(struct ifnet *ifp, struct in6_addr *in6)
264 {
265 size_t hwaddr_len;
266 uint8_t *hwaddr;
267 static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
268
269 hwaddr = in6_get_interface_hwaddr(ifp, &hwaddr_len);
270 if (hwaddr == NULL || (hwaddr_len != 6 && hwaddr_len != 8))
271 return (-1);
272
273 /* make EUI64 address */
274 if (hwaddr_len == 8)
275 memcpy(&in6->s6_addr[8], hwaddr, 8);
276 else if (hwaddr_len == 6) {
277 in6->s6_addr[8] = hwaddr[0];
278 in6->s6_addr[9] = hwaddr[1];
279 in6->s6_addr[10] = hwaddr[2];
280 in6->s6_addr[11] = 0xff;
281 in6->s6_addr[12] = 0xfe;
282 in6->s6_addr[13] = hwaddr[3];
283 in6->s6_addr[14] = hwaddr[4];
284 in6->s6_addr[15] = hwaddr[5];
285 }
286
287 /* sanity check: g bit must not indicate "group" */
288 if (EUI64_GROUP(in6))
289 return -1;
290
291 /* convert EUI64 into IPv6 interface identifier */
292 EUI64_TO_IFID(in6);
293
294 /*
295 * sanity check: ifid must not be all zero, avoid conflict with
296 * subnet router anycast
297 */
298 if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 &&
299 bcmp(&in6->s6_addr[9], allzero, 7) == 0)
300 return -1;
301
302 return 0;
303 }
304
305 /*
306 * Validate generated interface id to make sure it does not fall in any reserved range:
307 *
308 * https://www.iana.org/assignments/ipv6-interface-ids/ipv6-interface-ids.xhtml
309 */
310 static bool
validate_ifid(uint8_t * iid)311 validate_ifid(uint8_t *iid)
312 {
313 static uint8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
314 static uint8_t reserved_eth[5] = { 0x02, 0x00, 0x5E, 0xFF, 0xFE };
315 static uint8_t reserved_anycast[7] = { 0xFD, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
316
317 /* Subnet-Router Anycast (RFC 4291) */
318 if (memcmp(iid, allzero, 8) == 0)
319 return (false);
320
321 /*
322 * Reserved IPv6 Interface Identifiers corresponding to the IANA Ethernet Block (RFC 4291)
323 * and
324 * Proxy Mobile IPv6 (RFC 6543)
325 */
326 if (memcmp(iid, reserved_eth, 5) == 0)
327 return (false);
328
329 /* Reserved Subnet Anycast Addresses (RFC 2526) */
330 if (memcmp(iid, reserved_anycast, 7) == 0 && iid[7] >= 0x80)
331 return (false);
332
333 return (true);
334 }
335
336 /*
337 * Get interface identifier for the specified interface, according to
338 * RFC 7217 Stable and Opaque IDs with SLAAC, using HMAC-SHA256 digest.
339 *
340 * in6 - upper 64bits are preserved
341 */
342 bool
in6_get_stableifid(struct ifnet * ifp,struct in6_addr * in6,int prefixlen)343 in6_get_stableifid(struct ifnet *ifp, struct in6_addr *in6, int prefixlen)
344 {
345 struct sockaddr_dl *sdl;
346 const uint8_t *netiface;
347 size_t netiface_len, hostuuid_len;
348 uint8_t hostuuid[HOSTUUIDLEN + 1], hmac_key[SHA256_BLOCK_LENGTH],
349 hk_ipad[SHA256_BLOCK_LENGTH], hk_opad[SHA256_BLOCK_LENGTH];
350 uint64_t dad_failures;
351 SHA256_CTX ctxt;
352
353 switch (V_ip6_stableaddr_netifsource) {
354 case IP6_STABLEADDR_NETIFSRC_ID:
355 sdl = get_interface_link_level(ifp);
356 if (sdl == NULL)
357 return (false);
358 netiface = (uint8_t *)&LLINDEX(sdl);
359 netiface_len = sizeof(u_short); /* real return type of LLINDEX */
360 break;
361
362 case IP6_STABLEADDR_NETIFSRC_MAC:
363 netiface = in6_get_interface_hwaddr(ifp, &netiface_len);
364 if (netiface == NULL)
365 return (false);
366 break;
367
368 case IP6_STABLEADDR_NETIFSRC_NAME:
369 default:
370 netiface = (const uint8_t *)if_name(ifp);
371 netiface_len = strlen(netiface);
372 break;
373 }
374
375 /* Use hostuuid as constant "secret" key */
376 getcredhostuuid(curthread->td_ucred, hostuuid, sizeof(hostuuid));
377 if (strncmp(hostuuid, DEFAULT_HOSTUUID, sizeof(hostuuid)) == 0) {
378 /* If hostuuid is not set, use a random value */
379 arc4rand(hostuuid, HOSTUUIDLEN, 0);
380 hostuuid[HOSTUUIDLEN] = '\0';
381 }
382 hostuuid_len = strlen(hostuuid);
383
384 dad_failures = atomic_load_int(&DAD_FAILURES(ifp));
385
386 /* RFC 7217 section 7, default max retries */
387 if (dad_failures > V_ip6_stableaddr_maxretries)
388 return (false);
389
390 /*
391 * Use hostuuid as basis for HMAC key
392 */
393 memset(hmac_key, 0, sizeof(hmac_key));
394 if (hostuuid_len <= SHA256_BLOCK_LENGTH) {
395 /* copy to hmac key variable, zero padded */
396 memcpy(hmac_key, hostuuid, hostuuid_len);
397 } else {
398 /* if longer than block length, use hash of the value, zero padded */
399 SHA256_Init(&ctxt);
400 SHA256_Update(&ctxt, hostuuid, hostuuid_len);
401 SHA256_Final(hmac_key, &ctxt);
402 }
403 /* XOR key with ipad and opad values */
404 for (uint16_t i = 0; i < sizeof(hmac_key); i++) {
405 hk_ipad[i] = hmac_key[i] ^ HMAC_IPAD;
406 hk_opad[i] = hmac_key[i] ^ HMAC_OPAD;
407 }
408
409 /*
410 * Generate interface id in a loop, adding an offset to be factored in the hash function.
411 * This is necessary, because if the generated interface id happens to be invalid we
412 * want to force the hash function to generate a different one, otherwise we would end up
413 * in an infinite loop trying the same invalid interface id over and over again.
414 *
415 * Using an uint8 counter for the offset, so limit iteration at UINT8_MAX. This is a safety
416 * measure, this will never iterate more than once or twice in practice.
417 */
418 for(uint8_t offset = 0; offset < UINT8_MAX; offset++) {
419 uint8_t digest[SHA256_DIGEST_LENGTH];
420
421 /* Calculate inner hash */
422 SHA256_Init(&ctxt);
423 SHA256_Update(&ctxt, hk_ipad, sizeof(hk_ipad));
424 SHA256_Update(&ctxt, in6->s6_addr, prefixlen / 8);
425 SHA256_Update(&ctxt, netiface, netiface_len);
426 SHA256_Update(&ctxt, (uint8_t *)&dad_failures, 8);
427 SHA256_Update(&ctxt, hostuuid, hostuuid_len);
428 SHA256_Update(&ctxt, &offset, 1);
429 SHA256_Final(digest, &ctxt);
430
431 /* Calculate outer hash */
432 SHA256_Init(&ctxt);
433 SHA256_Update(&ctxt, hk_opad, sizeof(hk_opad));
434 SHA256_Update(&ctxt, digest, sizeof(digest));
435 SHA256_Final(digest, &ctxt);
436
437 if (validate_ifid(digest)) {
438 /* assumes sizeof(digest) > sizeof(ifid) */
439 memcpy(&in6->s6_addr[8], digest, 8);
440
441 return (true);
442 }
443 }
444
445 return (false);
446 }
447
448 /*
449 * Get interface identifier for the specified interface. If it is not
450 * available on ifp0, borrow interface identifier from other information
451 * sources.
452 *
453 * altifp - secondary EUI64 source
454 */
455 int
in6_get_ifid(struct ifnet * ifp0,struct ifnet * altifp,struct in6_addr * in6)456 in6_get_ifid(struct ifnet *ifp0, struct ifnet *altifp,
457 struct in6_addr *in6)
458 {
459 struct ifnet *ifp;
460
461 NET_EPOCH_ASSERT();
462
463 /* first, try to get it from the interface itself, with stable algorithm, if configured */
464 if ((ifp0->if_inet6->nd_flags & ND6_IFF_STABLEADDR) && in6_get_stableifid(ifp0, in6, 64) == 0) {
465 nd6log((LOG_DEBUG, "%s: got interface identifier from itself (stable private)\n",
466 if_name(ifp0)));
467 goto success;
468 }
469
470 /* then/otherwise try to get it from the interface itself */
471 if (in6_get_hw_ifid(ifp0, in6) == 0) {
472 nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n",
473 if_name(ifp0)));
474 goto success;
475 }
476
477 /* try secondary EUI64 source. this basically is for ATM PVC */
478 if (altifp && in6_get_hw_ifid(altifp, in6) == 0) {
479 nd6log((LOG_DEBUG, "%s: got interface identifier from %s\n",
480 if_name(ifp0), if_name(altifp)));
481 goto success;
482 }
483
484 /* next, try to get it from some other hardware interface */
485 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
486 if (ifp == ifp0)
487 continue;
488 if (in6_get_hw_ifid(ifp, in6) != 0)
489 continue;
490
491 /*
492 * to borrow ifid from other interface, ifid needs to be
493 * globally unique
494 */
495 if (IFID_UNIVERSAL(in6)) {
496 nd6log((LOG_DEBUG,
497 "%s: borrow interface identifier from %s\n",
498 if_name(ifp0), if_name(ifp)));
499 goto success;
500 }
501 }
502
503 /* last resort: get from random number source */
504 if (get_rand_ifid(ifp, in6) == 0) {
505 nd6log((LOG_DEBUG,
506 "%s: interface identifier generated by random number\n",
507 if_name(ifp0)));
508 goto success;
509 }
510
511 printf("%s: failed to get interface identifier\n", if_name(ifp0));
512 return -1;
513
514 success:
515 nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
516 if_name(ifp0), in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10],
517 in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13],
518 in6->s6_addr[14], in6->s6_addr[15]));
519 return 0;
520 }
521
522 /*
523 * altifp - secondary EUI64 source
524 */
525 static int
in6_ifattach_linklocal(struct ifnet * ifp,struct ifnet * altifp)526 in6_ifattach_linklocal(struct ifnet *ifp, struct ifnet *altifp)
527 {
528 struct in6_ifaddr *ia;
529 struct in6_aliasreq ifra;
530 struct nd_prefixctl pr0;
531 struct epoch_tracker et;
532 struct nd_prefix *pr;
533 int error;
534
535 /*
536 * configure link-local address.
537 */
538 in6_prepare_ifra(&ifra, NULL, &in6mask64);
539
540 ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000);
541 ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
542 if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
543 ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
544 ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
545 } else {
546 NET_EPOCH_ENTER(et);
547 error = in6_get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr);
548 NET_EPOCH_EXIT(et);
549 if (error != 0) {
550 nd6log((LOG_ERR,
551 "%s: no ifid available\n", if_name(ifp)));
552 return (-1);
553 }
554 }
555 if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL))
556 return (-1);
557
558 /* link-local addresses should NEVER expire. */
559 ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
560 ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
561
562 /*
563 * Now call in6_update_ifa() to do a bunch of procedures to configure
564 * a link-local address. We can set the 3rd argument to NULL, because
565 * we know there's no other link-local address on the interface
566 * and therefore we are adding one (instead of updating one).
567 */
568 if ((error = in6_update_ifa(ifp, &ifra, NULL,
569 IN6_IFAUPDATE_DADDELAY)) != 0) {
570 /*
571 * XXX: When the interface does not support IPv6, this call
572 * would fail in the SIOCSIFADDR ioctl. I believe the
573 * notification is rather confusing in this case, so just
574 * suppress it. (jinmei@kame.net 20010130)
575 */
576 if (error != EAFNOSUPPORT)
577 nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to "
578 "configure a link-local address on %s "
579 "(errno=%d)\n",
580 if_name(ifp), error));
581 return (-1);
582 }
583
584 NET_EPOCH_ENTER(et);
585 ia = in6ifa_ifpforlinklocal(ifp, 0);
586 NET_EPOCH_EXIT(et);
587 if (ia == NULL) {
588 /*
589 * Another thread removed the address that we just added.
590 * This should be rare, but it happens.
591 */
592 nd6log((LOG_NOTICE, "%s: %s: new link-local address "
593 "disappeared\n", __func__, if_name(ifp)));
594 return (-1);
595 }
596 ifa_free(&ia->ia_ifa);
597
598 /*
599 * Make the link-local prefix (fe80::%link/64) as on-link.
600 * Since we'd like to manage prefixes separately from addresses,
601 * we make an ND6 prefix structure for the link-local prefix,
602 * and add it to the prefix list as a never-expire prefix.
603 * XXX: this change might affect some existing code base...
604 */
605 bzero(&pr0, sizeof(pr0));
606 pr0.ndpr_ifp = ifp;
607 /* this should be 64 at this moment. */
608 pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
609 pr0.ndpr_prefix = ifra.ifra_addr;
610 /* apply the mask for safety. (nd6_prelist_add will apply it again) */
611 IN6_MASK_ADDR(&pr0.ndpr_prefix.sin6_addr, &in6mask64);
612 /*
613 * Initialize parameters. The link-local prefix must always be
614 * on-link, and its lifetimes never expire.
615 */
616 pr0.ndpr_raf_onlink = 1;
617 pr0.ndpr_raf_auto = 1; /* probably meaningless */
618 pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
619 pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
620 /*
621 * Since there is no other link-local addresses, nd6_prefix_lookup()
622 * probably returns NULL. However, we cannot always expect the result.
623 * For example, if we first remove the (only) existing link-local
624 * address, and then reconfigure another one, the prefix is still
625 * valid with referring to the old link-local address.
626 */
627 if ((pr = nd6_prefix_lookup(&pr0)) == NULL) {
628 if ((error = nd6_prelist_add(&pr0, NULL, &pr)) != 0)
629 return (error);
630 /* Reference prefix */
631 ia->ia6_ndpr = pr;
632 pr->ndpr_addrcnt++;
633 }
634 nd6_prefix_rele(pr);
635
636 return 0;
637 }
638
639 /*
640 * ifp - must be IFT_LOOP
641 */
642 static int
in6_ifattach_loopback(struct ifnet * ifp)643 in6_ifattach_loopback(struct ifnet *ifp)
644 {
645 struct in6_aliasreq ifra;
646 int error;
647
648 in6_prepare_ifra(&ifra, &in6addr_loopback, &in6mask128);
649
650 /*
651 * Always initialize ia_dstaddr (= broadcast address) to loopback
652 * address. Follows IPv4 practice - see in_ifinit().
653 */
654 ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
655 ifra.ifra_dstaddr.sin6_family = AF_INET6;
656 ifra.ifra_dstaddr.sin6_addr = in6addr_loopback;
657
658 /* the loopback address should NEVER expire. */
659 ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
660 ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
661
662 /*
663 * We are sure that this is a newly assigned address, so we can set
664 * NULL to the 3rd arg.
665 */
666 if ((error = in6_update_ifa(ifp, &ifra, NULL, 0)) != 0) {
667 nd6log((LOG_ERR, "in6_ifattach_loopback: failed to configure "
668 "the loopback address on %s (errno=%d)\n",
669 if_name(ifp), error));
670 return (-1);
671 }
672
673 return 0;
674 }
675
676 /*
677 * compute NI group address, based on the current hostname setting.
678 * see RFC 4620.
679 *
680 * when ifp == NULL, the caller is responsible for filling scopeid.
681 *
682 * If oldmcprefix == 1, FF02:0:0:0:0:2::/96 is used for NI group address
683 * while it is FF02:0:0:0:0:2:FF00::/104 in RFC 4620.
684 */
685 static int
in6_nigroup0(struct ifnet * ifp,const char * name,int namelen,struct in6_addr * in6,int oldmcprefix)686 in6_nigroup0(struct ifnet *ifp, const char *name, int namelen,
687 struct in6_addr *in6, int oldmcprefix)
688 {
689 struct prison *pr;
690 const char *p;
691 u_char *q;
692 MD5_CTX ctxt;
693 u_int8_t digest[16];
694 char l;
695 char n[64]; /* a single label must not exceed 63 chars */
696
697 /*
698 * If no name is given and namelen is -1,
699 * we try to do the hostname lookup ourselves.
700 */
701 if (!name && namelen == -1) {
702 pr = curthread->td_ucred->cr_prison;
703 mtx_lock(&pr->pr_mtx);
704 name = pr->pr_hostname;
705 namelen = strlen(name);
706 } else
707 pr = NULL;
708 if (!name || !namelen) {
709 if (pr != NULL)
710 mtx_unlock(&pr->pr_mtx);
711 return -1;
712 }
713
714 p = name;
715 while (p && *p && *p != '.' && p - name < namelen)
716 p++;
717 if (p == name || p - name > sizeof(n) - 1) {
718 if (pr != NULL)
719 mtx_unlock(&pr->pr_mtx);
720 return -1; /* label too long */
721 }
722 l = p - name;
723 strncpy(n, name, l);
724 if (pr != NULL)
725 mtx_unlock(&pr->pr_mtx);
726 n[(int)l] = '\0';
727 for (q = n; *q; q++) {
728 if ('A' <= *q && *q <= 'Z')
729 *q = *q - 'A' + 'a';
730 }
731
732 /* generate 16 bytes of pseudo-random value. */
733 bzero(&ctxt, sizeof(ctxt));
734 MD5Init(&ctxt);
735 MD5Update(&ctxt, &l, sizeof(l));
736 MD5Update(&ctxt, n, l);
737 MD5Final(digest, &ctxt);
738
739 bzero(in6, sizeof(*in6));
740 in6->s6_addr16[0] = IPV6_ADDR_INT16_MLL;
741 in6->s6_addr8[11] = 2;
742 if (oldmcprefix == 0) {
743 in6->s6_addr8[12] = 0xff;
744 /* Copy the first 24 bits of 128-bit hash into the address. */
745 bcopy(digest, &in6->s6_addr8[13], 3);
746 } else {
747 /* Copy the first 32 bits of 128-bit hash into the address. */
748 bcopy(digest, &in6->s6_addr32[3], sizeof(in6->s6_addr32[3]));
749 }
750 if (in6_setscope(in6, ifp, NULL))
751 return (-1); /* XXX: should not fail */
752
753 return 0;
754 }
755
756 int
in6_nigroup(struct ifnet * ifp,const char * name,int namelen,struct in6_addr * in6)757 in6_nigroup(struct ifnet *ifp, const char *name, int namelen,
758 struct in6_addr *in6)
759 {
760
761 return (in6_nigroup0(ifp, name, namelen, in6, 0));
762 }
763
764 int
in6_nigroup_oldmcprefix(struct ifnet * ifp,const char * name,int namelen,struct in6_addr * in6)765 in6_nigroup_oldmcprefix(struct ifnet *ifp, const char *name, int namelen,
766 struct in6_addr *in6)
767 {
768
769 return (in6_nigroup0(ifp, name, namelen, in6, 1));
770 }
771
772 /*
773 * XXX multiple loopback interface needs more care. for instance,
774 * nodelocal address needs to be configured onto only one of them.
775 * XXX multiple link-local address case
776 *
777 * altifp - secondary EUI64 source
778 */
779 void
in6_ifattach(struct ifnet * ifp,struct ifnet * altifp)780 in6_ifattach(struct ifnet *ifp, struct ifnet *altifp)
781 {
782 struct in6_ifaddr *ia;
783
784 /* XXXGL: can this happen after IFT_PFLOG and IFT_PFSYNC are gone? */
785 if (ifp->if_inet6 == NULL)
786 return;
787 /*
788 * quirks based on interface type
789 */
790 switch (ifp->if_type) {
791 case IFT_STF:
792 /*
793 * 6to4 interface is a very special kind of beast.
794 * no multicast, no linklocal. RFC2529 specifies how to make
795 * linklocals for 6to4 interface, but there's no use and
796 * it is rather harmful to have one.
797 */
798 ifp->if_inet6->nd_flags &= ~ND6_IFF_AUTO_LINKLOCAL;
799 ifp->if_inet6->nd_flags |= ND6_IFF_NO_DAD;
800 break;
801 default:
802 break;
803 }
804
805 /*
806 * usually, we require multicast capability to the interface
807 */
808 if ((ifp->if_flags & IFF_MULTICAST) == 0) {
809 nd6log((LOG_INFO, "in6_ifattach: "
810 "%s is not multicast capable, IPv6 not enabled\n",
811 if_name(ifp)));
812 return;
813 }
814
815 /*
816 * assign loopback address for loopback interface.
817 */
818 if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
819 /*
820 * check that loopback address doesn't exist yet.
821 */
822 ia = in6ifa_ifwithaddr(&in6addr_loopback, 0, false);
823 if (ia == NULL)
824 in6_ifattach_loopback(ifp);
825 }
826
827 /*
828 * assign a link-local address, if there's none.
829 */
830 if (!(ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED) &&
831 ifp->if_inet6->nd_flags & ND6_IFF_AUTO_LINKLOCAL) {
832 struct epoch_tracker et;
833
834 NET_EPOCH_ENTER(et);
835 ia = in6ifa_ifpforlinklocal(ifp, 0);
836 NET_EPOCH_EXIT(et);
837 if (ia == NULL)
838 in6_ifattach_linklocal(ifp, altifp);
839 else
840 ifa_free(&ia->ia_ifa);
841 }
842 }
843
844 /*
845 * NOTE: in6_ifdetach() does not support loopback if at this moment.
846 *
847 * When shutting down a VNET we clean up layers top-down. In that case
848 * upper layer protocols (ulp) are cleaned up already and locks are destroyed
849 * and we must not call into these cleanup functions anymore, thus purgeulp
850 * is set to 0 in that case by in6_ifdetach_destroy().
851 * The normal case of destroying a (cloned) interface still needs to cleanup
852 * everything related to the interface and will have purgeulp set to 1.
853 */
854 static void
_in6_ifdetach(struct ifnet * ifp,int purgeulp)855 _in6_ifdetach(struct ifnet *ifp, int purgeulp)
856 {
857 struct ifaddr *ifa, *next;
858
859 /* XXXGL: can this happen after IFT_PFLOG and IFT_PFSYNC are gone? */
860 if (ifp->if_inet6 == NULL)
861 return;
862
863 /*
864 * nuke any of IPv6 addresses we have
865 */
866 CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
867 if (ifa->ifa_addr->sa_family != AF_INET6)
868 continue;
869 in6_purgeaddr(ifa);
870 }
871 if (purgeulp) {
872 IN6_MULTI_LOCK();
873 in6_pcbpurgeif0(&V_udbinfo, ifp);
874 in6_pcbpurgeif0(&V_ulitecbinfo, ifp);
875 in6_pcbpurgeif0(&V_ripcbinfo, ifp);
876 IN6_MULTI_UNLOCK();
877 }
878 /* leave from all multicast groups joined */
879 in6_purgemaddrs(ifp);
880
881 /*
882 * Remove neighbor management table.
883 * Enabling the nd6_purge will panic on vmove for interfaces on VNET
884 * teardown as the IPv6 layer is cleaned up already and the locks
885 * are destroyed.
886 */
887 if (purgeulp)
888 nd6_purge(ifp);
889 }
890
891 void
in6_ifdetach(struct ifnet * ifp)892 in6_ifdetach(struct ifnet *ifp)
893 {
894
895 _in6_ifdetach(ifp, 1);
896 }
897
898 static void
in6_ifextra_free(epoch_context_t ctx)899 in6_ifextra_free(epoch_context_t ctx)
900 {
901 struct in6_ifextra *ext =
902 __containerof(ctx, struct in6_ifextra, epoch_ctx);
903
904 COUNTER_ARRAY_FREE(ext->in6_ifstat,
905 sizeof(struct in6_ifstat) / sizeof(uint64_t));
906 COUNTER_ARRAY_FREE(ext->icmp6_ifstat,
907 sizeof(struct icmp6_ifstat) / sizeof(uint64_t));
908 free(ext, M_IFADDR);
909 }
910
911 static void
in6_ifdeparture(void * arg __unused,struct ifnet * ifp)912 in6_ifdeparture(void *arg __unused, struct ifnet *ifp)
913 {
914 struct in6_ifextra *ext = ifp->if_inet6;
915
916 /* XXXGL: can this happen after IFT_PFLOG and IFT_PFSYNC are gone? */
917 if (ifp->if_inet6 == NULL)
918 return;
919
920 #ifdef VIMAGE
921 /*
922 * On VNET shutdown abort here as the stack teardown will do all
923 * the work top-down for us. XXXGL: see comment in in.c:in_ifdetach().
924 */
925 if (!VNET_IS_SHUTTING_DOWN(ifp->if_vnet))
926 #endif
927 _in6_ifdetach(ifp, 1);
928 /*
929 * XXXGL: mld and nd bits are left in a consistent state after
930 * destructors, but I'm not sure if it safe to call lltable_free() here.
931 * Individual lle entries are epoch(9) protected, but the table itself
932 * isn't.
933 */
934 mld_domifdetach(ifp);
935 nd6_ifdetach(ifp);
936 lltable_free(ext->lltable);
937 NET_EPOCH_CALL(in6_ifextra_free, &ext->epoch_ctx);
938 }
939 EVENTHANDLER_DEFINE(ifnet_departure_event, in6_ifdeparture, NULL,
940 EVENTHANDLER_PRI_ANY);
941
942 void
in6_ifdetach_destroy(struct ifnet * ifp)943 in6_ifdetach_destroy(struct ifnet *ifp)
944 {
945
946 _in6_ifdetach(ifp, 0);
947 }
948
949 void
in6_tmpaddrtimer(void * arg)950 in6_tmpaddrtimer(void *arg)
951 {
952 CURVNET_SET((struct vnet *) arg);
953
954 callout_reset(&V_in6_tmpaddrtimer_ch,
955 (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
956 V_ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, curvnet);
957
958 CURVNET_RESTORE();
959 }
960
961 static void
in6_purgemaddrs(struct ifnet * ifp)962 in6_purgemaddrs(struct ifnet *ifp)
963 {
964 struct in6_multi_head inmh;
965
966 SLIST_INIT(&inmh);
967 IN6_MULTI_LOCK();
968 IN6_MULTI_LIST_LOCK();
969 mld_ifdetach(ifp, &inmh);
970 IN6_MULTI_LIST_UNLOCK();
971 IN6_MULTI_UNLOCK();
972 in6m_release_list_deferred(&inmh);
973
974 /*
975 * Make sure all multicast deletions invoking if_ioctl() are
976 * completed before returning. Else we risk accessing a freed
977 * ifnet structure pointer.
978 */
979 in6m_release_wait(NULL);
980 }
981
982 void
in6_ifattach_destroy(void)983 in6_ifattach_destroy(void)
984 {
985
986 callout_drain(&V_in6_tmpaddrtimer_ch);
987 }
988
989 static void
in6_ifattach_init(void * dummy)990 in6_ifattach_init(void *dummy)
991 {
992
993 /* Timer for regeneranation of temporary addresses randomize ID. */
994 callout_init(&V_in6_tmpaddrtimer_ch, 1);
995 callout_reset(&V_in6_tmpaddrtimer_ch,
996 (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
997 V_ip6_temp_regen_advance) * hz,
998 in6_tmpaddrtimer, curvnet);
999 }
1000
1001 /*
1002 * Cheat.
1003 * This must be after route_init(), which is now SI_ORDER_THIRD.
1004 */
1005 SYSINIT(in6_ifattach_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
1006 in6_ifattach_init, NULL);
1007