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