in6_ifattach.c revision 1.106
1/* $OpenBSD: in6_ifattach.c,v 1.106 2018/03/13 13:58:03 florian Exp $ */ 2/* $KAME: in6_ifattach.c,v 1.124 2001/07/18 08:32:51 jinmei Exp $ */ 3 4/* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33#include <sys/param.h> 34#include <sys/systm.h> 35#include <sys/socket.h> 36#include <sys/sockio.h> 37#include <sys/kernel.h> 38#include <sys/syslog.h> 39 40#include <crypto/sha2.h> 41 42#include <net/if.h> 43#include <net/if_var.h> 44#include <net/if_dl.h> 45#include <net/if_types.h> 46#include <net/route.h> 47 48#include <netinet/in.h> 49 50#include <netinet6/in6_var.h> 51#include <netinet/ip6.h> 52#include <netinet6/ip6_var.h> 53#include <netinet6/in6_ifattach.h> 54#include <netinet6/nd6.h> 55#ifdef MROUTING 56#include <netinet6/ip6_mroute.h> 57#endif 58 59void in6_get_rand_ifid(struct ifnet *, struct in6_addr *); 60int in6_get_hw_ifid(struct ifnet *, struct in6_addr *); 61int in6_get_soii_ifid(struct ifnet *, struct in6_addr *); 62void in6_get_ifid(struct ifnet *, struct in6_addr *); 63int in6_ifattach_loopback(struct ifnet *); 64 65#define EUI64_GBIT 0x01 66#define EUI64_UBIT 0x02 67#define EUI64_TO_IFID(in6) do {(in6)->s6_addr[8] ^= EUI64_UBIT; } while (0) 68#define EUI64_GROUP(in6) ((in6)->s6_addr[8] & EUI64_GBIT) 69#define EUI64_INDIVIDUAL(in6) (!EUI64_GROUP(in6)) 70#define EUI64_LOCAL(in6) ((in6)->s6_addr[8] & EUI64_UBIT) 71#define EUI64_UNIVERSAL(in6) (!EUI64_LOCAL(in6)) 72 73#define IFID_LOCAL(in6) (!EUI64_LOCAL(in6)) 74#define IFID_UNIVERSAL(in6) (!EUI64_UNIVERSAL(in6)) 75 76void 77in6_soiiupdate(struct ifnet *ifp) 78{ 79 struct ifaddr *ifa; 80 81 NET_ASSERT_LOCKED(); 82 83 /* 84 * Update the link-local address. 85 */ 86 ifa = &in6ifa_ifpforlinklocal(ifp, 0)->ia_ifa; 87 if (ifa) { 88 in6_purgeaddr(ifa); 89 dohooks(ifp->if_addrhooks, 0); 90 in6_ifattach(ifp); 91 } 92} 93 94/* 95 * Generate a random interface identifier. 96 * 97 * in6 - upper 64bits are preserved 98 */ 99void 100in6_get_rand_ifid(struct ifnet *ifp, struct in6_addr *in6) 101{ 102 arc4random_buf(&in6->s6_addr32[2], 8); 103 104 /* make sure to set "u" bit to local, and "g" bit to individual. */ 105 in6->s6_addr[8] &= ~EUI64_GBIT; /* g bit to "individual" */ 106 in6->s6_addr[8] |= EUI64_UBIT; /* u bit to "local" */ 107 108 /* convert EUI64 into IPv6 interface identifier */ 109 EUI64_TO_IFID(in6); 110} 111 112/* 113 * Get interface identifier for the specified interface. 114 * 115 * in6 - upper 64bits are preserved 116 */ 117int 118in6_get_hw_ifid(struct ifnet *ifp, struct in6_addr *in6) 119{ 120 struct sockaddr_dl *sdl; 121 char *addr; 122 size_t addrlen; 123 static u_int8_t allzero[8] = { 0, 0, 0, 0, 0, 0, 0, 0 }; 124 static u_int8_t allone[8] = 125 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 126 127 sdl = ifp->if_sadl; 128 if (sdl == NULL || sdl->sdl_alen == 0) 129 return -1; 130 131 addr = LLADDR(sdl); 132 addrlen = sdl->sdl_alen; 133 134 switch (ifp->if_type) { 135 case IFT_IEEE1394: 136 case IFT_IEEE80211: 137 /* IEEE1394 uses 16byte length address starting with EUI64 */ 138 if (addrlen > 8) 139 addrlen = 8; 140 break; 141 default: 142 break; 143 } 144 145 /* get EUI64 */ 146 switch (ifp->if_type) { 147 /* IEEE802/EUI64 cases - what others? */ 148 case IFT_ETHER: 149 case IFT_CARP: 150 case IFT_IEEE1394: 151 case IFT_IEEE80211: 152 /* look at IEEE802/EUI64 only */ 153 if (addrlen != 8 && addrlen != 6) 154 return -1; 155 156 /* 157 * check for invalid MAC address - on bsdi, we see it a lot 158 * since wildboar configures all-zero MAC on pccard before 159 * card insertion. 160 */ 161 if (bcmp(addr, allzero, addrlen) == 0) 162 return -1; 163 if (bcmp(addr, allone, addrlen) == 0) 164 return -1; 165 166 /* make EUI64 address */ 167 if (addrlen == 8) 168 bcopy(addr, &in6->s6_addr[8], 8); 169 else if (addrlen == 6) { 170 in6->s6_addr[8] = addr[0]; 171 in6->s6_addr[9] = addr[1]; 172 in6->s6_addr[10] = addr[2]; 173 in6->s6_addr[11] = 0xff; 174 in6->s6_addr[12] = 0xfe; 175 in6->s6_addr[13] = addr[3]; 176 in6->s6_addr[14] = addr[4]; 177 in6->s6_addr[15] = addr[5]; 178 } 179 break; 180 181 case IFT_GIF: 182 /* 183 * RFC2893 says: "SHOULD use IPv4 address as ifid source". 184 * however, IPv4 address is not very suitable as unique 185 * identifier source (can be renumbered). 186 * we don't do this. 187 */ 188 return -1; 189 190 default: 191 return -1; 192 } 193 194 /* sanity check: g bit must not indicate "group" */ 195 if (EUI64_GROUP(in6)) 196 return -1; 197 198 /* convert EUI64 into IPv6 interface identifier */ 199 EUI64_TO_IFID(in6); 200 201 /* 202 * sanity check: ifid must not be all zero, avoid conflict with 203 * subnet router anycast 204 */ 205 if ((in6->s6_addr[8] & ~(EUI64_GBIT | EUI64_UBIT)) == 0x00 && 206 bcmp(&in6->s6_addr[9], allzero, 7) == 0) { 207 return -1; 208 } 209 210 return 0; 211} 212 213/* 214 * Generate a Semantically Opaque Interface Identifier according to RFC 7217 215 * 216 * in6 - upper 64bits are preserved 217 */ 218int 219in6_get_soii_ifid(struct ifnet *ifp, struct in6_addr *in6) 220{ 221 SHA2_CTX ctx; 222 u_int8_t digest[SHA512_DIGEST_LENGTH]; 223 struct in6_addr prefix; 224 struct sockaddr_dl *sdl; 225 int dad_counter = 0; /* XXX not used */ 226 char *addr; 227 228 if (ifp->if_xflags & IFXF_INET6_NOSOII) 229 return -1; 230 231 sdl = ifp->if_sadl; 232 if (sdl == NULL || sdl->sdl_alen == 0) 233 return -1; 234 235 memset(&prefix, 0, sizeof(prefix)); 236 prefix.s6_addr16[0] = htons(0xfe80); 237 addr = LLADDR(sdl); 238 239 SHA512Init(&ctx); 240 241 SHA512Update(&ctx, &prefix, sizeof(prefix)); 242 SHA512Update(&ctx, addr, sdl->sdl_alen); 243 SHA512Update(&ctx, &dad_counter, sizeof(dad_counter)); 244 SHA512Update(&ctx, ip6_soiikey, sizeof(ip6_soiikey)); 245 SHA512Final(digest, &ctx); 246 247 bcopy(digest + (sizeof(digest) - 8), &in6->s6_addr[8], 8); 248 249 return 0; 250} 251 252/* 253 * Get interface identifier for the specified interface. If it is not 254 * available on ifp0, borrow interface identifier from other information 255 * sources. 256 */ 257void 258in6_get_ifid(struct ifnet *ifp0, struct in6_addr *in6) 259{ 260 struct ifnet *ifp; 261 262 /* first, try to generate a Semantically Opaque Interface Identifier */ 263 if (in6_get_soii_ifid(ifp0, in6) == 0) { 264 nd6log((LOG_DEBUG, "%s: got Semantically Opaque Interface " 265 "Identifier\n", ifp0->if_xname)); 266 goto success; 267 } 268 269 /* next, try to get it from the interface itself */ 270 if (in6_get_hw_ifid(ifp0, in6) == 0) { 271 nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n", 272 ifp0->if_xname)); 273 goto success; 274 } 275 276 /* next, try to get it from some other hardware interface */ 277 TAILQ_FOREACH(ifp, &ifnet, if_list) { 278 if (ifp == ifp0) 279 continue; 280 if (in6_get_hw_ifid(ifp, in6) != 0) 281 continue; 282 283 /* 284 * to borrow ifid from other interface, ifid needs to be 285 * globally unique 286 */ 287 if (IFID_UNIVERSAL(in6)) { 288 nd6log((LOG_DEBUG, 289 "%s: borrow interface identifier from %s\n", 290 ifp0->if_xname, ifp->if_xname)); 291 goto success; 292 } 293 } 294 295 /* last resort: get from random number source */ 296 in6_get_rand_ifid(ifp, in6); 297 nd6log((LOG_DEBUG, 298 "%s: interface identifier generated by random number\n", 299 ifp0->if_xname)); 300success: 301 nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n", 302 ifp0->if_xname, in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10], 303 in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13], 304 in6->s6_addr[14], in6->s6_addr[15])); 305} 306 307/* 308 * ifid - used as EUI64 if not NULL, overrides other EUI64 sources 309 */ 310 311int 312in6_ifattach_linklocal(struct ifnet *ifp, struct in6_addr *ifid) 313{ 314 struct in6_aliasreq ifra; 315 struct in6_ifaddr *ia6; 316 int error, flags; 317 318 NET_ASSERT_LOCKED(); 319 320 /* 321 * configure link-local address. 322 */ 323 bzero(&ifra, sizeof(ifra)); 324 strncpy(ifra.ifra_name, ifp->if_xname, sizeof(ifra.ifra_name)); 325 ifra.ifra_addr.sin6_family = AF_INET6; 326 ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6); 327 ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80); 328 ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 329 ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0; 330 if ((ifp->if_flags & IFF_LOOPBACK) != 0) { 331 ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0; 332 ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1); 333 } else if (ifid) { 334 ifra.ifra_addr.sin6_addr = *ifid; 335 ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80); 336 ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 337 ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0; 338 ifra.ifra_addr.sin6_addr.s6_addr[8] &= ~EUI64_GBIT; 339 ifra.ifra_addr.sin6_addr.s6_addr[8] |= EUI64_UBIT; 340 } else 341 in6_get_ifid(ifp, &ifra.ifra_addr.sin6_addr); 342 343 ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6); 344 ifra.ifra_prefixmask.sin6_family = AF_INET6; 345 ifra.ifra_prefixmask.sin6_addr = in6mask64; 346 /* link-local addresses should NEVER expire. */ 347 ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME; 348 ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME; 349 350 /* 351 * XXX: Some P2P interfaces seem not to send packets just after 352 * becoming up, so we skip p2p interfaces for safety. 353 */ 354 if (in6if_do_dad(ifp) && ((ifp->if_flags & IFF_POINTOPOINT) == 0)) 355 ifra.ifra_flags |= IN6_IFF_TENTATIVE; 356 357 error = in6_update_ifa(ifp, &ifra, in6ifa_ifpforlinklocal(ifp, 0)); 358 if (error != 0) 359 return (error); 360 361 ia6 = in6ifa_ifpforlinklocal(ifp, 0); 362 363 /* Perform DAD, if needed. */ 364 if (ia6->ia6_flags & IN6_IFF_TENTATIVE) 365 nd6_dad_start(&ia6->ia_ifa); 366 367 if (ifp->if_flags & IFF_LOOPBACK) { 368 dohooks(ifp->if_addrhooks, 0); 369 return (0); /* No need to install a connected route. */ 370 } 371 372 flags = RTF_CONNECTED; 373 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 374 flags |= RTF_CLONING; 375 376 error = rt_ifa_add(&ia6->ia_ifa, flags, ia6->ia_ifa.ifa_addr); 377 if (error) { 378 in6_purgeaddr(&ia6->ia_ifa); 379 return (error); 380 } 381 dohooks(ifp->if_addrhooks, 0); 382 383 return (0); 384} 385 386int 387in6_ifattach_loopback(struct ifnet *ifp) 388{ 389 struct in6_aliasreq ifra; 390 391 KASSERT(ifp->if_flags & IFF_LOOPBACK); 392 393 bzero(&ifra, sizeof(ifra)); 394 strncpy(ifra.ifra_name, ifp->if_xname, sizeof(ifra.ifra_name)); 395 ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6); 396 ifra.ifra_prefixmask.sin6_family = AF_INET6; 397 ifra.ifra_prefixmask.sin6_addr = in6mask128; 398 399 /* 400 * Always initialize ia_dstaddr (= broadcast address) to loopback 401 * address. Follows IPv4 practice - see in_ifinit(). 402 */ 403 ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6); 404 ifra.ifra_dstaddr.sin6_family = AF_INET6; 405 ifra.ifra_dstaddr.sin6_addr = in6addr_loopback; 406 407 ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6); 408 ifra.ifra_addr.sin6_family = AF_INET6; 409 ifra.ifra_addr.sin6_addr = in6addr_loopback; 410 411 /* the loopback address should NEVER expire. */ 412 ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME; 413 ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME; 414 415 /* 416 * We are sure that this is a newly assigned address, so we can set 417 * NULL to the 3rd arg. 418 */ 419 return (in6_update_ifa(ifp, &ifra, NULL)); 420} 421 422/* 423 * compute NI group address, based on the current hostname setting. 424 * see draft-ietf-ipngwg-icmp-name-lookup-* (04 and later). 425 * 426 * when ifp == NULL, the caller is responsible for filling scopeid. 427 */ 428int 429in6_nigroup(struct ifnet *ifp, const char *name, int namelen, 430 struct sockaddr_in6 *sa6) 431{ 432 const char *p; 433 u_int8_t *q; 434 SHA2_CTX ctx; 435 u_int8_t digest[SHA512_DIGEST_LENGTH]; 436 u_int8_t l; 437 u_int8_t n[64]; /* a single label must not exceed 63 chars */ 438 439 if (!namelen || !name) 440 return -1; 441 442 p = name; 443 while (p && *p && *p != '.' && p - name < namelen) 444 p++; 445 if (p - name > sizeof(n) - 1) 446 return -1; /* label too long */ 447 l = p - name; 448 strncpy((char *)n, name, l); 449 n[(int)l] = '\0'; 450 for (q = n; *q; q++) { 451 if ('A' <= *q && *q <= 'Z') 452 *q = *q - 'A' + 'a'; 453 } 454 455 /* generate 8 bytes of pseudo-random value. */ 456 SHA512Init(&ctx); 457 SHA512Update(&ctx, &l, sizeof(l)); 458 SHA512Update(&ctx, n, l); 459 SHA512Final(digest, &ctx); 460 461 bzero(sa6, sizeof(*sa6)); 462 sa6->sin6_family = AF_INET6; 463 sa6->sin6_len = sizeof(*sa6); 464 sa6->sin6_addr.s6_addr16[0] = htons(0xff02); 465 sa6->sin6_addr.s6_addr16[1] = htons(ifp->if_index); 466 sa6->sin6_addr.s6_addr8[11] = 2; 467 bcopy(digest, &sa6->sin6_addr.s6_addr32[3], 468 sizeof(sa6->sin6_addr.s6_addr32[3])); 469 470 return 0; 471} 472 473/* 474 * XXX multiple loopback interface needs more care. for instance, 475 * nodelocal address needs to be configured onto only one of them. 476 * XXX multiple link-local address case 477 */ 478int 479in6_ifattach(struct ifnet *ifp) 480{ 481 /* some of the interfaces are inherently not IPv6 capable */ 482 switch (ifp->if_type) { 483 case IFT_BRIDGE: 484 case IFT_ENC: 485 case IFT_PFLOG: 486 case IFT_PFSYNC: 487 return (0); 488 } 489 490 /* 491 * if link mtu is too small, don't try to configure IPv6. 492 * remember there could be some link-layer that has special 493 * fragmentation logic. 494 */ 495 if (ifp->if_mtu < IPV6_MMTU) 496 return (EINVAL); 497 498 if ((ifp->if_flags & IFF_MULTICAST) == 0) 499 return (EINVAL); 500 501 /* Assign loopback address, if there's none. */ 502 if (ifp->if_flags & IFF_LOOPBACK) { 503 struct in6_addr in6 = in6addr_loopback; 504 int error; 505 506 if (in6ifa_ifpwithaddr(ifp, &in6) != NULL) 507 return (0); 508 509 error = in6_ifattach_loopback(ifp); 510 if (error) 511 return (error); 512 } 513 514 /* Assign a link-local address, if there's none. */ 515 if (in6ifa_ifpforlinklocal(ifp, 0) == NULL) { 516 if (in6_ifattach_linklocal(ifp, NULL) != 0) { 517 /* failed to assign linklocal address. bark? */ 518 } 519 } 520 521 return (0); 522} 523 524/* 525 * NOTE: in6_ifdetach() does not support loopback if at this moment. 526 */ 527void 528in6_ifdetach(struct ifnet *ifp) 529{ 530 struct ifaddr *ifa, *next; 531 struct rtentry *rt; 532 struct sockaddr_in6 sin6; 533 534#ifdef MROUTING 535 /* remove ip6_mrouter stuff */ 536 ip6_mrouter_detach(ifp); 537#endif 538 539 /* nuke any of IPv6 addresses we have */ 540 TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrlist, ifa_list, next) { 541 if (ifa->ifa_addr->sa_family != AF_INET6) 542 continue; 543 in6_purgeaddr(ifa); 544 dohooks(ifp->if_addrhooks, 0); 545 } 546 547 /* 548 * Remove neighbor management table. Must be called after 549 * purging addresses. 550 */ 551 nd6_purge(ifp); 552 553 /* remove route to interface local allnodes multicast (ff01::1) */ 554 bzero(&sin6, sizeof(sin6)); 555 sin6.sin6_len = sizeof(struct sockaddr_in6); 556 sin6.sin6_family = AF_INET6; 557 sin6.sin6_addr = in6addr_intfacelocal_allnodes; 558 sin6.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 559 rt = rtalloc(sin6tosa(&sin6), 0, ifp->if_rdomain); 560 if (rt && rt->rt_ifidx == ifp->if_index) { 561 rtdeletemsg(rt, ifp, ifp->if_rdomain); 562 rtfree(rt); 563 } 564 565 /* remove route to link-local allnodes multicast (ff02::1) */ 566 bzero(&sin6, sizeof(sin6)); 567 sin6.sin6_len = sizeof(struct sockaddr_in6); 568 sin6.sin6_family = AF_INET6; 569 sin6.sin6_addr = in6addr_linklocal_allnodes; 570 sin6.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 571 rt = rtalloc(sin6tosa(&sin6), 0, ifp->if_rdomain); 572 if (rt && rt->rt_ifidx == ifp->if_index) { 573 rtdeletemsg(rt, ifp, ifp->if_rdomain); 574 rtfree(rt); 575 } 576 577 if (ifp->if_xflags & IFXF_AUTOCONF6) 578 ifp->if_xflags &= ~IFXF_AUTOCONF6; 579} 580