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 /*
387 * RFC 7217 section 7
388 *
389 * default max retries
390 */
391 if (dad_failures > V_ip6_stableaddr_maxretries)
392 return (false);
393
394 /*
395 * Use hostuuid as basis for HMAC key
396 */
397 memset(hmac_key, 0, sizeof(hmac_key));
398 if (hostuuid_len <= SHA256_BLOCK_LENGTH) {
399 /* copy to hmac key variable, zero padded */
400 memcpy(hmac_key, hostuuid, hostuuid_len);
401 } else {
402 /* if longer than block length, use hash of the value, zero padded */
403 SHA256_Init(&ctxt);
404 SHA256_Update(&ctxt, hostuuid, hostuuid_len);
405 SHA256_Final(hmac_key, &ctxt);
406 }
407 /* XOR key with ipad and opad values */
408 for (uint16_t i = 0; i < sizeof(hmac_key); i++) {
409 hk_ipad[i] = hmac_key[i] ^ HMAC_IPAD;
410 hk_opad[i] = hmac_key[i] ^ HMAC_OPAD;
411 }
412
413 /*
414 * Generate interface id in a loop, adding an offset to be factored in the hash function.
415 * This is necessary, because if the generated interface id happens to be invalid we
416 * want to force the hash function to generate a different one, otherwise we would end up
417 * in an infinite loop trying the same invalid interface id over and over again.
418 *
419 * Using an uint8 counter for the offset, so limit iteration at UINT8_MAX. This is a safety
420 * measure, this will never iterate more than once or twice in practice.
421 */
422 for(uint8_t offset = 0; offset < UINT8_MAX; offset++) {
423 uint8_t digest[SHA256_DIGEST_LENGTH];
424
425 /* Calculate inner hash */
426 SHA256_Init(&ctxt);
427 SHA256_Update(&ctxt, hk_ipad, sizeof(hk_ipad));
428 SHA256_Update(&ctxt, in6->s6_addr, prefixlen / 8);
429 SHA256_Update(&ctxt, netiface, netiface_len);
430 SHA256_Update(&ctxt, (uint8_t *)&dad_failures, 8);
431 SHA256_Update(&ctxt, hostuuid, hostuuid_len);
432 SHA256_Update(&ctxt, &offset, 1);
433 SHA256_Final(digest, &ctxt);
434
435 /* Calculate outer hash */
436 SHA256_Init(&ctxt);
437 SHA256_Update(&ctxt, hk_opad, sizeof(hk_opad));
438 SHA256_Update(&ctxt, digest, sizeof(digest));
439 SHA256_Final(digest, &ctxt);
440
441 if (validate_ifid(digest)) {
442 /* assumes sizeof(digest) > sizeof(ifid) */
443 memcpy(&in6->s6_addr[8], digest, 8);
444
445 return (true);
446 }
447 }
448
449 return (false);
450 }
451
452 /*
453 * Get interface identifier for the specified interface. If it is not
454 * available on ifp0, borrow interface identifier from other information
455 * sources.
456 *
457 * altifp - secondary EUI64 source
458 */
459 int
in6_get_ifid(struct ifnet * ifp0,struct ifnet * altifp,struct in6_addr * in6)460 in6_get_ifid(struct ifnet *ifp0, struct ifnet *altifp,
461 struct in6_addr *in6)
462 {
463 struct ifnet *ifp;
464
465 NET_EPOCH_ASSERT();
466
467 /* first, try to get it from the interface itself, with stable algorithm, if configured */
468 if ((ND_IFINFO(ifp0)->flags & ND6_IFF_STABLEADDR) && in6_get_stableifid(ifp0, in6, 64) == 0) {
469 nd6log((LOG_DEBUG, "%s: got interface identifier from itself (stable private)\n",
470 if_name(ifp0)));
471 goto success;
472 }
473
474 /* then/otherwise try to get it from the interface itself */
475 if (in6_get_hw_ifid(ifp0, in6) == 0) {
476 nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n",
477 if_name(ifp0)));
478 goto success;
479 }
480
481 /* try secondary EUI64 source. this basically is for ATM PVC */
482 if (altifp && in6_get_hw_ifid(altifp, in6) == 0) {
483 nd6log((LOG_DEBUG, "%s: got interface identifier from %s\n",
484 if_name(ifp0), if_name(altifp)));
485 goto success;
486 }
487
488 /* next, try to get it from some other hardware interface */
489 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
490 if (ifp == ifp0)
491 continue;
492 if (in6_get_hw_ifid(ifp, in6) != 0)
493 continue;
494
495 /*
496 * to borrow ifid from other interface, ifid needs to be
497 * globally unique
498 */
499 if (IFID_UNIVERSAL(in6)) {
500 nd6log((LOG_DEBUG,
501 "%s: borrow interface identifier from %s\n",
502 if_name(ifp0), if_name(ifp)));
503 goto success;
504 }
505 }
506
507 /* last resort: get from random number source */
508 if (get_rand_ifid(ifp, in6) == 0) {
509 nd6log((LOG_DEBUG,
510 "%s: interface identifier generated by random number\n",
511 if_name(ifp0)));
512 goto success;
513 }
514
515 printf("%s: failed to get interface identifier\n", if_name(ifp0));
516 return -1;
517
518 success:
519 nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
520 if_name(ifp0), in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10],
521 in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13],
522 in6->s6_addr[14], in6->s6_addr[15]));
523 return 0;
524 }
525
526 /*
527 * altifp - secondary EUI64 source
528 */
529 static int
in6_ifattach_linklocal(struct ifnet * ifp,struct ifnet * altifp)530 in6_ifattach_linklocal(struct ifnet *ifp, struct ifnet *altifp)
531 {
532 struct in6_ifaddr *ia;
533 struct in6_aliasreq ifra;
534 struct nd_prefixctl pr0;
535 struct epoch_tracker et;
536 struct nd_prefix *pr;
537 int error;
538
539 /*
540 * configure link-local address.
541 */
542 in6_prepare_ifra(&ifra, NULL, &in6mask64);
543
544 ifra.ifra_addr.sin6_addr.s6_addr32[0] = htonl(0xfe800000);
545 ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
546 if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
547 ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0;
548 ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1);
549 } else {
550 NET_EPOCH_ENTER(et);
551 error = in6_get_ifid(ifp, altifp, &ifra.ifra_addr.sin6_addr);
552 NET_EPOCH_EXIT(et);
553 if (error != 0) {
554 nd6log((LOG_ERR,
555 "%s: no ifid available\n", if_name(ifp)));
556 return (-1);
557 }
558 }
559 if (in6_setscope(&ifra.ifra_addr.sin6_addr, ifp, NULL))
560 return (-1);
561
562 /* link-local addresses should NEVER expire. */
563 ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
564 ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
565
566 /*
567 * Now call in6_update_ifa() to do a bunch of procedures to configure
568 * a link-local address. We can set the 3rd argument to NULL, because
569 * we know there's no other link-local address on the interface
570 * and therefore we are adding one (instead of updating one).
571 */
572 if ((error = in6_update_ifa(ifp, &ifra, NULL,
573 IN6_IFAUPDATE_DADDELAY)) != 0) {
574 /*
575 * XXX: When the interface does not support IPv6, this call
576 * would fail in the SIOCSIFADDR ioctl. I believe the
577 * notification is rather confusing in this case, so just
578 * suppress it. (jinmei@kame.net 20010130)
579 */
580 if (error != EAFNOSUPPORT)
581 nd6log((LOG_NOTICE, "in6_ifattach_linklocal: failed to "
582 "configure a link-local address on %s "
583 "(errno=%d)\n",
584 if_name(ifp), error));
585 return (-1);
586 }
587
588 NET_EPOCH_ENTER(et);
589 ia = in6ifa_ifpforlinklocal(ifp, 0);
590 NET_EPOCH_EXIT(et);
591 if (ia == NULL) {
592 /*
593 * Another thread removed the address that we just added.
594 * This should be rare, but it happens.
595 */
596 nd6log((LOG_NOTICE, "%s: %s: new link-local address "
597 "disappeared\n", __func__, if_name(ifp)));
598 return (-1);
599 }
600 ifa_free(&ia->ia_ifa);
601
602 /*
603 * Make the link-local prefix (fe80::%link/64) as on-link.
604 * Since we'd like to manage prefixes separately from addresses,
605 * we make an ND6 prefix structure for the link-local prefix,
606 * and add it to the prefix list as a never-expire prefix.
607 * XXX: this change might affect some existing code base...
608 */
609 bzero(&pr0, sizeof(pr0));
610 pr0.ndpr_ifp = ifp;
611 /* this should be 64 at this moment. */
612 pr0.ndpr_plen = in6_mask2len(&ifra.ifra_prefixmask.sin6_addr, NULL);
613 pr0.ndpr_prefix = ifra.ifra_addr;
614 /* apply the mask for safety. (nd6_prelist_add will apply it again) */
615 IN6_MASK_ADDR(&pr0.ndpr_prefix.sin6_addr, &in6mask64);
616 /*
617 * Initialize parameters. The link-local prefix must always be
618 * on-link, and its lifetimes never expire.
619 */
620 pr0.ndpr_raf_onlink = 1;
621 pr0.ndpr_raf_auto = 1; /* probably meaningless */
622 pr0.ndpr_vltime = ND6_INFINITE_LIFETIME;
623 pr0.ndpr_pltime = ND6_INFINITE_LIFETIME;
624 /*
625 * Since there is no other link-local addresses, nd6_prefix_lookup()
626 * probably returns NULL. However, we cannot always expect the result.
627 * For example, if we first remove the (only) existing link-local
628 * address, and then reconfigure another one, the prefix is still
629 * valid with referring to the old link-local address.
630 */
631 if ((pr = nd6_prefix_lookup(&pr0)) == NULL) {
632 if ((error = nd6_prelist_add(&pr0, NULL, &pr)) != 0)
633 return (error);
634 /* Reference prefix */
635 ia->ia6_ndpr = pr;
636 pr->ndpr_addrcnt++;
637 } else
638 nd6_prefix_rele(pr);
639
640 return 0;
641 }
642
643 /*
644 * ifp - must be IFT_LOOP
645 */
646 static int
in6_ifattach_loopback(struct ifnet * ifp)647 in6_ifattach_loopback(struct ifnet *ifp)
648 {
649 struct in6_aliasreq ifra;
650 int error;
651
652 in6_prepare_ifra(&ifra, &in6addr_loopback, &in6mask128);
653
654 /*
655 * Always initialize ia_dstaddr (= broadcast address) to loopback
656 * address. Follows IPv4 practice - see in_ifinit().
657 */
658 ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
659 ifra.ifra_dstaddr.sin6_family = AF_INET6;
660 ifra.ifra_dstaddr.sin6_addr = in6addr_loopback;
661
662 /* the loopback address should NEVER expire. */
663 ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
664 ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
665
666 /*
667 * We are sure that this is a newly assigned address, so we can set
668 * NULL to the 3rd arg.
669 */
670 if ((error = in6_update_ifa(ifp, &ifra, NULL, 0)) != 0) {
671 nd6log((LOG_ERR, "in6_ifattach_loopback: failed to configure "
672 "the loopback address on %s (errno=%d)\n",
673 if_name(ifp), error));
674 return (-1);
675 }
676
677 return 0;
678 }
679
680 /*
681 * compute NI group address, based on the current hostname setting.
682 * see RFC 4620.
683 *
684 * when ifp == NULL, the caller is responsible for filling scopeid.
685 *
686 * If oldmcprefix == 1, FF02:0:0:0:0:2::/96 is used for NI group address
687 * while it is FF02:0:0:0:0:2:FF00::/104 in RFC 4620.
688 */
689 static int
in6_nigroup0(struct ifnet * ifp,const char * name,int namelen,struct in6_addr * in6,int oldmcprefix)690 in6_nigroup0(struct ifnet *ifp, const char *name, int namelen,
691 struct in6_addr *in6, int oldmcprefix)
692 {
693 struct prison *pr;
694 const char *p;
695 u_char *q;
696 MD5_CTX ctxt;
697 u_int8_t digest[16];
698 char l;
699 char n[64]; /* a single label must not exceed 63 chars */
700
701 /*
702 * If no name is given and namelen is -1,
703 * we try to do the hostname lookup ourselves.
704 */
705 if (!name && namelen == -1) {
706 pr = curthread->td_ucred->cr_prison;
707 mtx_lock(&pr->pr_mtx);
708 name = pr->pr_hostname;
709 namelen = strlen(name);
710 } else
711 pr = NULL;
712 if (!name || !namelen) {
713 if (pr != NULL)
714 mtx_unlock(&pr->pr_mtx);
715 return -1;
716 }
717
718 p = name;
719 while (p && *p && *p != '.' && p - name < namelen)
720 p++;
721 if (p == name || p - name > sizeof(n) - 1) {
722 if (pr != NULL)
723 mtx_unlock(&pr->pr_mtx);
724 return -1; /* label too long */
725 }
726 l = p - name;
727 strncpy(n, name, l);
728 if (pr != NULL)
729 mtx_unlock(&pr->pr_mtx);
730 n[(int)l] = '\0';
731 for (q = n; *q; q++) {
732 if ('A' <= *q && *q <= 'Z')
733 *q = *q - 'A' + 'a';
734 }
735
736 /* generate 16 bytes of pseudo-random value. */
737 bzero(&ctxt, sizeof(ctxt));
738 MD5Init(&ctxt);
739 MD5Update(&ctxt, &l, sizeof(l));
740 MD5Update(&ctxt, n, l);
741 MD5Final(digest, &ctxt);
742
743 bzero(in6, sizeof(*in6));
744 in6->s6_addr16[0] = IPV6_ADDR_INT16_MLL;
745 in6->s6_addr8[11] = 2;
746 if (oldmcprefix == 0) {
747 in6->s6_addr8[12] = 0xff;
748 /* Copy the first 24 bits of 128-bit hash into the address. */
749 bcopy(digest, &in6->s6_addr8[13], 3);
750 } else {
751 /* Copy the first 32 bits of 128-bit hash into the address. */
752 bcopy(digest, &in6->s6_addr32[3], sizeof(in6->s6_addr32[3]));
753 }
754 if (in6_setscope(in6, ifp, NULL))
755 return (-1); /* XXX: should not fail */
756
757 return 0;
758 }
759
760 int
in6_nigroup(struct ifnet * ifp,const char * name,int namelen,struct in6_addr * in6)761 in6_nigroup(struct ifnet *ifp, const char *name, int namelen,
762 struct in6_addr *in6)
763 {
764
765 return (in6_nigroup0(ifp, name, namelen, in6, 0));
766 }
767
768 int
in6_nigroup_oldmcprefix(struct ifnet * ifp,const char * name,int namelen,struct in6_addr * in6)769 in6_nigroup_oldmcprefix(struct ifnet *ifp, const char *name, int namelen,
770 struct in6_addr *in6)
771 {
772
773 return (in6_nigroup0(ifp, name, namelen, in6, 1));
774 }
775
776 /*
777 * XXX multiple loopback interface needs more care. for instance,
778 * nodelocal address needs to be configured onto only one of them.
779 * XXX multiple link-local address case
780 *
781 * altifp - secondary EUI64 source
782 */
783 void
in6_ifattach(struct ifnet * ifp,struct ifnet * altifp)784 in6_ifattach(struct ifnet *ifp, struct ifnet *altifp)
785 {
786 struct in6_ifaddr *ia;
787
788 /* XXXGL: can this happen after IFT_PFLOG and IFT_PFSYNC are gone? */
789 if (ifp->if_inet6 == NULL)
790 return;
791 /*
792 * quirks based on interface type
793 */
794 switch (ifp->if_type) {
795 case IFT_STF:
796 /*
797 * 6to4 interface is a very special kind of beast.
798 * no multicast, no linklocal. RFC2529 specifies how to make
799 * linklocals for 6to4 interface, but there's no use and
800 * it is rather harmful to have one.
801 */
802 ND_IFINFO(ifp)->flags &= ~ND6_IFF_AUTO_LINKLOCAL;
803 ND_IFINFO(ifp)->flags |= ND6_IFF_NO_DAD;
804 break;
805 default:
806 break;
807 }
808
809 /*
810 * usually, we require multicast capability to the interface
811 */
812 if ((ifp->if_flags & IFF_MULTICAST) == 0) {
813 nd6log((LOG_INFO, "in6_ifattach: "
814 "%s is not multicast capable, IPv6 not enabled\n",
815 if_name(ifp)));
816 return;
817 }
818
819 /*
820 * assign loopback address for loopback interface.
821 */
822 if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
823 /*
824 * check that loopback address doesn't exist yet.
825 */
826 ia = in6ifa_ifwithaddr(&in6addr_loopback, 0, false);
827 if (ia == NULL)
828 in6_ifattach_loopback(ifp);
829 }
830
831 /*
832 * assign a link-local address, if there's none.
833 */
834 if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
835 ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL) {
836 struct epoch_tracker et;
837
838 NET_EPOCH_ENTER(et);
839 ia = in6ifa_ifpforlinklocal(ifp, 0);
840 NET_EPOCH_EXIT(et);
841 if (ia == NULL)
842 in6_ifattach_linklocal(ifp, altifp);
843 else
844 ifa_free(&ia->ia_ifa);
845 }
846 }
847
848 /*
849 * NOTE: in6_ifdetach() does not support loopback if at this moment.
850 *
851 * When shutting down a VNET we clean up layers top-down. In that case
852 * upper layer protocols (ulp) are cleaned up already and locks are destroyed
853 * and we must not call into these cleanup functions anymore, thus purgeulp
854 * is set to 0 in that case by in6_ifdetach_destroy().
855 * The normal case of destroying a (cloned) interface still needs to cleanup
856 * everything related to the interface and will have purgeulp set to 1.
857 */
858 static void
_in6_ifdetach(struct ifnet * ifp,int purgeulp)859 _in6_ifdetach(struct ifnet *ifp, int purgeulp)
860 {
861 struct ifaddr *ifa, *next;
862
863 /* XXXGL: can this happen after IFT_PFLOG and IFT_PFSYNC are gone? */
864 if (ifp->if_inet6 == NULL)
865 return;
866
867 /*
868 * nuke any of IPv6 addresses we have
869 */
870 CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
871 if (ifa->ifa_addr->sa_family != AF_INET6)
872 continue;
873 in6_purgeaddr(ifa);
874 }
875 if (purgeulp) {
876 IN6_MULTI_LOCK();
877 in6_pcbpurgeif0(&V_udbinfo, ifp);
878 in6_pcbpurgeif0(&V_ulitecbinfo, ifp);
879 in6_pcbpurgeif0(&V_ripcbinfo, ifp);
880 IN6_MULTI_UNLOCK();
881 }
882 /* leave from all multicast groups joined */
883 in6_purgemaddrs(ifp);
884
885 /*
886 * Remove neighbor management table.
887 * Enabling the nd6_purge will panic on vmove for interfaces on VNET
888 * teardown as the IPv6 layer is cleaned up already and the locks
889 * are destroyed.
890 */
891 if (purgeulp)
892 nd6_purge(ifp);
893 }
894
895 void
in6_ifdetach(struct ifnet * ifp)896 in6_ifdetach(struct ifnet *ifp)
897 {
898
899 _in6_ifdetach(ifp, 1);
900 }
901
902 static void
in6_ifdeparture(void * arg __unused,struct ifnet * ifp)903 in6_ifdeparture(void *arg __unused, struct ifnet *ifp)
904 {
905 struct in6_ifextra *ext = ifp->if_inet6;
906
907 /* XXXGL: can this happen after IFT_PFLOG and IFT_PFSYNC are gone? */
908 if (ifp->if_inet6 == NULL)
909 return;
910
911 #ifdef VIMAGE
912 /*
913 * On VNET shutdown abort here as the stack teardown will do all
914 * the work top-down for us. XXXGL: see comment in in.c:in_ifdetach().
915 */
916 if (!VNET_IS_SHUTTING_DOWN(ifp->if_vnet))
917 #endif
918 _in6_ifdetach(ifp, 1);
919 mld_domifdetach(ifp);
920 scope6_ifdetach(ext->scope6_id);
921 nd6_ifdetach(ifp, ext->nd_ifinfo);
922 lltable_free(ext->lltable);
923 COUNTER_ARRAY_FREE(ext->in6_ifstat,
924 sizeof(struct in6_ifstat) / sizeof(uint64_t));
925 free(ext->in6_ifstat, M_IFADDR);
926 COUNTER_ARRAY_FREE(ext->icmp6_ifstat,
927 sizeof(struct icmp6_ifstat) / sizeof(uint64_t));
928 free(ext->icmp6_ifstat, M_IFADDR);
929 free(ext, M_IFADDR);
930 }
931 EVENTHANDLER_DEFINE(ifnet_departure_event, in6_ifdeparture, NULL,
932 EVENTHANDLER_PRI_ANY);
933
934 void
in6_ifdetach_destroy(struct ifnet * ifp)935 in6_ifdetach_destroy(struct ifnet *ifp)
936 {
937
938 _in6_ifdetach(ifp, 0);
939 }
940
941 void
in6_tmpaddrtimer(void * arg)942 in6_tmpaddrtimer(void *arg)
943 {
944 CURVNET_SET((struct vnet *) arg);
945
946 callout_reset(&V_in6_tmpaddrtimer_ch,
947 (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
948 V_ip6_temp_regen_advance) * hz, in6_tmpaddrtimer, curvnet);
949
950 CURVNET_RESTORE();
951 }
952
953 static void
in6_purgemaddrs(struct ifnet * ifp)954 in6_purgemaddrs(struct ifnet *ifp)
955 {
956 struct in6_multi_head inmh;
957
958 SLIST_INIT(&inmh);
959 IN6_MULTI_LOCK();
960 IN6_MULTI_LIST_LOCK();
961 mld_ifdetach(ifp, &inmh);
962 IN6_MULTI_LIST_UNLOCK();
963 IN6_MULTI_UNLOCK();
964 in6m_release_list_deferred(&inmh);
965
966 /*
967 * Make sure all multicast deletions invoking if_ioctl() are
968 * completed before returning. Else we risk accessing a freed
969 * ifnet structure pointer.
970 */
971 in6m_release_wait(NULL);
972 }
973
974 void
in6_ifattach_destroy(void)975 in6_ifattach_destroy(void)
976 {
977
978 callout_drain(&V_in6_tmpaddrtimer_ch);
979 }
980
981 static void
in6_ifattach_init(void * dummy)982 in6_ifattach_init(void *dummy)
983 {
984
985 /* Timer for regeneranation of temporary addresses randomize ID. */
986 callout_init(&V_in6_tmpaddrtimer_ch, 1);
987 callout_reset(&V_in6_tmpaddrtimer_ch,
988 (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
989 V_ip6_temp_regen_advance) * hz,
990 in6_tmpaddrtimer, curvnet);
991 }
992
993 /*
994 * Cheat.
995 * This must be after route_init(), which is now SI_ORDER_THIRD.
996 */
997 SYSINIT(in6_ifattach_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE,
998 in6_ifattach_init, NULL);
999