in6_ifattach.c revision 1.108
1/* $OpenBSD: in6_ifattach.c,v 1.108 2018/07/10 20:43:26 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 memcpy(&in6->s6_addr[8], addr, 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 memcpy(&in6->s6_addr[8], digest + (sizeof(digest) - 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 goto success; 282 } 283 284 /* last resort: get from random number source */ 285 in6_get_rand_ifid(ifp, in6); 286 nd6log((LOG_DEBUG, 287 "%s: interface identifier generated by random number\n", 288 ifp0->if_xname)); 289success: 290 nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n", 291 ifp0->if_xname, in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10], 292 in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13], 293 in6->s6_addr[14], in6->s6_addr[15])); 294} 295 296/* 297 * ifid - used as EUI64 if not NULL, overrides other EUI64 sources 298 */ 299 300int 301in6_ifattach_linklocal(struct ifnet *ifp, struct in6_addr *ifid) 302{ 303 struct in6_aliasreq ifra; 304 struct in6_ifaddr *ia6; 305 int error, flags; 306 307 NET_ASSERT_LOCKED(); 308 309 /* 310 * configure link-local address. 311 */ 312 bzero(&ifra, sizeof(ifra)); 313 strncpy(ifra.ifra_name, ifp->if_xname, sizeof(ifra.ifra_name)); 314 ifra.ifra_addr.sin6_family = AF_INET6; 315 ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6); 316 ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80); 317 ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 318 ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0; 319 if ((ifp->if_flags & IFF_LOOPBACK) != 0) { 320 ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0; 321 ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1); 322 } else if (ifid) { 323 ifra.ifra_addr.sin6_addr = *ifid; 324 ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80); 325 ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 326 ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0; 327 ifra.ifra_addr.sin6_addr.s6_addr[8] &= ~EUI64_GBIT; 328 ifra.ifra_addr.sin6_addr.s6_addr[8] |= EUI64_UBIT; 329 } else 330 in6_get_ifid(ifp, &ifra.ifra_addr.sin6_addr); 331 332 ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6); 333 ifra.ifra_prefixmask.sin6_family = AF_INET6; 334 ifra.ifra_prefixmask.sin6_addr = in6mask64; 335 /* link-local addresses should NEVER expire. */ 336 ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME; 337 ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME; 338 339 /* 340 * XXX: Some P2P interfaces seem not to send packets just after 341 * becoming up, so we skip p2p interfaces for safety. 342 */ 343 if (in6if_do_dad(ifp) && ((ifp->if_flags & IFF_POINTOPOINT) == 0)) 344 ifra.ifra_flags |= IN6_IFF_TENTATIVE; 345 346 error = in6_update_ifa(ifp, &ifra, in6ifa_ifpforlinklocal(ifp, 0)); 347 if (error != 0) 348 return (error); 349 350 ia6 = in6ifa_ifpforlinklocal(ifp, 0); 351 352 /* Perform DAD, if needed. */ 353 if (ia6->ia6_flags & IN6_IFF_TENTATIVE) 354 nd6_dad_start(&ia6->ia_ifa); 355 356 if (ifp->if_flags & IFF_LOOPBACK) { 357 dohooks(ifp->if_addrhooks, 0); 358 return (0); /* No need to install a connected route. */ 359 } 360 361 flags = RTF_CONNECTED; 362 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 363 flags |= RTF_CLONING; 364 365 error = rt_ifa_add(&ia6->ia_ifa, flags, ia6->ia_ifa.ifa_addr); 366 if (error) { 367 in6_purgeaddr(&ia6->ia_ifa); 368 return (error); 369 } 370 dohooks(ifp->if_addrhooks, 0); 371 372 return (0); 373} 374 375int 376in6_ifattach_loopback(struct ifnet *ifp) 377{ 378 struct in6_aliasreq ifra; 379 380 KASSERT(ifp->if_flags & IFF_LOOPBACK); 381 382 bzero(&ifra, sizeof(ifra)); 383 strncpy(ifra.ifra_name, ifp->if_xname, sizeof(ifra.ifra_name)); 384 ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6); 385 ifra.ifra_prefixmask.sin6_family = AF_INET6; 386 ifra.ifra_prefixmask.sin6_addr = in6mask128; 387 388 /* 389 * Always initialize ia_dstaddr (= broadcast address) to loopback 390 * address. Follows IPv4 practice - see in_ifinit(). 391 */ 392 ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6); 393 ifra.ifra_dstaddr.sin6_family = AF_INET6; 394 ifra.ifra_dstaddr.sin6_addr = in6addr_loopback; 395 396 ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6); 397 ifra.ifra_addr.sin6_family = AF_INET6; 398 ifra.ifra_addr.sin6_addr = in6addr_loopback; 399 400 /* the loopback address should NEVER expire. */ 401 ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME; 402 ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME; 403 404 /* 405 * We are sure that this is a newly assigned address, so we can set 406 * NULL to the 3rd arg. 407 */ 408 return (in6_update_ifa(ifp, &ifra, NULL)); 409} 410 411/* 412 * compute NI group address, based on the current hostname setting. 413 * see draft-ietf-ipngwg-icmp-name-lookup-* (04 and later). 414 * 415 * when ifp == NULL, the caller is responsible for filling scopeid. 416 */ 417int 418in6_nigroup(struct ifnet *ifp, const char *name, int namelen, 419 struct sockaddr_in6 *sa6) 420{ 421 const char *p; 422 u_int8_t *q; 423 SHA2_CTX ctx; 424 u_int8_t digest[SHA512_DIGEST_LENGTH]; 425 u_int8_t l; 426 u_int8_t n[64]; /* a single label must not exceed 63 chars */ 427 428 if (!namelen || !name) 429 return -1; 430 431 p = name; 432 while (p && *p && *p != '.' && p - name < namelen) 433 p++; 434 if (p - name > sizeof(n) - 1) 435 return -1; /* label too long */ 436 l = p - name; 437 strncpy((char *)n, name, l); 438 n[(int)l] = '\0'; 439 for (q = n; *q; q++) { 440 if ('A' <= *q && *q <= 'Z') 441 *q = *q - 'A' + 'a'; 442 } 443 444 /* generate 8 bytes of pseudo-random value. */ 445 SHA512Init(&ctx); 446 SHA512Update(&ctx, &l, sizeof(l)); 447 SHA512Update(&ctx, n, l); 448 SHA512Final(digest, &ctx); 449 450 bzero(sa6, sizeof(*sa6)); 451 sa6->sin6_family = AF_INET6; 452 sa6->sin6_len = sizeof(*sa6); 453 sa6->sin6_addr.s6_addr16[0] = htons(0xff02); 454 sa6->sin6_addr.s6_addr16[1] = htons(ifp->if_index); 455 sa6->sin6_addr.s6_addr8[11] = 2; 456 memcpy(&sa6->sin6_addr.s6_addr32[3], digest, 457 sizeof(sa6->sin6_addr.s6_addr32[3])); 458 459 return 0; 460} 461 462/* 463 * XXX multiple loopback interface needs more care. for instance, 464 * nodelocal address needs to be configured onto only one of them. 465 * XXX multiple link-local address case 466 */ 467int 468in6_ifattach(struct ifnet *ifp) 469{ 470 /* some of the interfaces are inherently not IPv6 capable */ 471 switch (ifp->if_type) { 472 case IFT_BRIDGE: 473 case IFT_ENC: 474 case IFT_PFLOG: 475 case IFT_PFSYNC: 476 return (0); 477 } 478 479 /* 480 * if link mtu is too small, don't try to configure IPv6. 481 * remember there could be some link-layer that has special 482 * fragmentation logic. 483 */ 484 if (ifp->if_mtu < IPV6_MMTU) 485 return (EINVAL); 486 487 if ((ifp->if_flags & IFF_MULTICAST) == 0) 488 return (EINVAL); 489 490 /* Assign loopback address, if there's none. */ 491 if (ifp->if_flags & IFF_LOOPBACK) { 492 struct in6_addr in6 = in6addr_loopback; 493 int error; 494 495 if (in6ifa_ifpwithaddr(ifp, &in6) != NULL) 496 return (0); 497 498 error = in6_ifattach_loopback(ifp); 499 if (error) 500 return (error); 501 } 502 503 /* Assign a link-local address, if there's none. */ 504 if (in6ifa_ifpforlinklocal(ifp, 0) == NULL) { 505 if (in6_ifattach_linklocal(ifp, NULL) != 0) { 506 /* failed to assign linklocal address. bark? */ 507 } 508 } 509 510 return (0); 511} 512 513/* 514 * NOTE: in6_ifdetach() does not support loopback if at this moment. 515 */ 516void 517in6_ifdetach(struct ifnet *ifp) 518{ 519 struct ifaddr *ifa, *next; 520 struct rtentry *rt; 521 struct sockaddr_in6 sin6; 522 523#ifdef MROUTING 524 /* remove ip6_mrouter stuff */ 525 ip6_mrouter_detach(ifp); 526#endif 527 528 /* nuke any of IPv6 addresses we have */ 529 TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrlist, ifa_list, next) { 530 if (ifa->ifa_addr->sa_family != AF_INET6) 531 continue; 532 in6_purgeaddr(ifa); 533 dohooks(ifp->if_addrhooks, 0); 534 } 535 536 /* 537 * Remove neighbor management table. Must be called after 538 * purging addresses. 539 */ 540 nd6_purge(ifp); 541 542 /* remove route to interface local allnodes multicast (ff01::1) */ 543 bzero(&sin6, sizeof(sin6)); 544 sin6.sin6_len = sizeof(struct sockaddr_in6); 545 sin6.sin6_family = AF_INET6; 546 sin6.sin6_addr = in6addr_intfacelocal_allnodes; 547 sin6.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 548 rt = rtalloc(sin6tosa(&sin6), 0, ifp->if_rdomain); 549 if (rt && rt->rt_ifidx == ifp->if_index) { 550 rtdeletemsg(rt, ifp, ifp->if_rdomain); 551 rtfree(rt); 552 } 553 554 /* remove route to link-local allnodes multicast (ff02::1) */ 555 bzero(&sin6, sizeof(sin6)); 556 sin6.sin6_len = sizeof(struct sockaddr_in6); 557 sin6.sin6_family = AF_INET6; 558 sin6.sin6_addr = in6addr_linklocal_allnodes; 559 sin6.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 560 rt = rtalloc(sin6tosa(&sin6), 0, ifp->if_rdomain); 561 if (rt && rt->rt_ifidx == ifp->if_index) { 562 rtdeletemsg(rt, ifp, ifp->if_rdomain); 563 rtfree(rt); 564 } 565 566 if (ifp->if_xflags & IFXF_AUTOCONF6) 567 ifp->if_xflags &= ~IFXF_AUTOCONF6; 568} 569