in6_ifattach.c revision 1.113
1/* $OpenBSD: in6_ifattach.c,v 1.113 2019/02/13 23:47:43 dlg 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 *ifp0, struct in6_addr *in6) 220{ 221 struct ifnet *ifp; 222 SHA2_CTX ctx; 223 u_int8_t digest[SHA512_DIGEST_LENGTH]; 224 struct in6_addr prefix; 225 struct sockaddr_dl *sdl; 226 int dad_counter = 0; /* XXX not used */ 227 char *addr; 228 229 if (ifp0->if_xflags & IFXF_INET6_NOSOII) 230 return -1; 231 232 sdl = ifp0->if_sadl; 233 234 if (sdl == NULL || sdl->sdl_alen == 0) { 235 /* 236 * try to get it from some other hardware interface like 237 * in in6_get_ifid() 238 */ 239 TAILQ_FOREACH(ifp, &ifnet, if_list) { 240 if (ifp == ifp0) 241 continue; 242 sdl = ifp->if_sadl; 243 if (sdl != NULL && sdl->sdl_alen != 0) 244 break; 245 } 246 } 247 248 if (sdl == NULL || sdl->sdl_alen == 0) 249 return -1; 250 251 memset(&prefix, 0, sizeof(prefix)); 252 prefix.s6_addr16[0] = htons(0xfe80); 253 addr = LLADDR(sdl); 254 255 SHA512Init(&ctx); 256 257 SHA512Update(&ctx, &prefix, sizeof(prefix)); 258 SHA512Update(&ctx, addr, sdl->sdl_alen); 259 SHA512Update(&ctx, &dad_counter, sizeof(dad_counter)); 260 SHA512Update(&ctx, ip6_soiikey, sizeof(ip6_soiikey)); 261 SHA512Final(digest, &ctx); 262 263 memcpy(&in6->s6_addr[8], digest + (sizeof(digest) - 8), 8); 264 265 return 0; 266} 267 268/* 269 * Get interface identifier for the specified interface. If it is not 270 * available on ifp0, borrow interface identifier from other information 271 * sources. 272 */ 273void 274in6_get_ifid(struct ifnet *ifp0, struct in6_addr *in6) 275{ 276 struct ifnet *ifp; 277 278 /* first, try to generate a Semantically Opaque Interface Identifier */ 279 if (in6_get_soii_ifid(ifp0, in6) == 0) { 280 nd6log((LOG_DEBUG, "%s: got Semantically Opaque Interface " 281 "Identifier\n", ifp0->if_xname)); 282 goto success; 283 } 284 285 /* next, try to get it from the interface itself */ 286 if (in6_get_hw_ifid(ifp0, in6) == 0) { 287 nd6log((LOG_DEBUG, "%s: got interface identifier from itself\n", 288 ifp0->if_xname)); 289 goto success; 290 } 291 292 /* next, try to get it from some other hardware interface */ 293 TAILQ_FOREACH(ifp, &ifnet, if_list) { 294 if (ifp == ifp0) 295 continue; 296 if (in6_get_hw_ifid(ifp, in6) == 0) 297 goto success; 298 } 299 300 /* last resort: get from random number source */ 301 in6_get_rand_ifid(ifp, in6); 302 nd6log((LOG_DEBUG, 303 "%s: interface identifier generated by random number\n", 304 ifp0->if_xname)); 305success: 306 nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n", 307 ifp0->if_xname, in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10], 308 in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13], 309 in6->s6_addr[14], in6->s6_addr[15])); 310} 311 312/* 313 * ifid - used as EUI64 if not NULL, overrides other EUI64 sources 314 */ 315 316int 317in6_ifattach_linklocal(struct ifnet *ifp, struct in6_addr *ifid) 318{ 319 struct in6_aliasreq ifra; 320 struct in6_ifaddr *ia6; 321 int error, flags; 322 323 NET_ASSERT_LOCKED(); 324 325 /* 326 * configure link-local address. 327 */ 328 bzero(&ifra, sizeof(ifra)); 329 strncpy(ifra.ifra_name, ifp->if_xname, sizeof(ifra.ifra_name)); 330 ifra.ifra_addr.sin6_family = AF_INET6; 331 ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6); 332 ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80); 333 ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 334 ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0; 335 if ((ifp->if_flags & IFF_LOOPBACK) != 0) { 336 ifra.ifra_addr.sin6_addr.s6_addr32[2] = 0; 337 ifra.ifra_addr.sin6_addr.s6_addr32[3] = htonl(1); 338 } else if (ifid) { 339 ifra.ifra_addr.sin6_addr = *ifid; 340 ifra.ifra_addr.sin6_addr.s6_addr16[0] = htons(0xfe80); 341 ifra.ifra_addr.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 342 ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0; 343 ifra.ifra_addr.sin6_addr.s6_addr[8] &= ~EUI64_GBIT; 344 ifra.ifra_addr.sin6_addr.s6_addr[8] |= EUI64_UBIT; 345 } else 346 in6_get_ifid(ifp, &ifra.ifra_addr.sin6_addr); 347 348 ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6); 349 ifra.ifra_prefixmask.sin6_family = AF_INET6; 350 ifra.ifra_prefixmask.sin6_addr = in6mask64; 351 /* link-local addresses should NEVER expire. */ 352 ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME; 353 ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME; 354 355 /* 356 * XXX: Some P2P interfaces seem not to send packets just after 357 * becoming up, so we skip p2p interfaces for safety. 358 */ 359 if (in6if_do_dad(ifp) && ((ifp->if_flags & IFF_POINTOPOINT) == 0)) 360 ifra.ifra_flags |= IN6_IFF_TENTATIVE; 361 362 error = in6_update_ifa(ifp, &ifra, in6ifa_ifpforlinklocal(ifp, 0)); 363 if (error != 0) 364 return (error); 365 366 ia6 = in6ifa_ifpforlinklocal(ifp, 0); 367 368 /* Perform DAD, if needed. */ 369 if (ia6->ia6_flags & IN6_IFF_TENTATIVE) 370 nd6_dad_start(&ia6->ia_ifa); 371 372 if (ifp->if_flags & IFF_LOOPBACK) { 373 dohooks(ifp->if_addrhooks, 0); 374 return (0); /* No need to install a connected route. */ 375 } 376 377 flags = RTF_CONNECTED | RTF_MPATH; 378 if ((ifp->if_flags & IFF_POINTOPOINT) == 0) 379 flags |= RTF_CLONING; 380 381 error = rt_ifa_add(&ia6->ia_ifa, flags, ia6->ia_ifa.ifa_addr, 382 ifp->if_rdomain); 383 if (error) { 384 in6_purgeaddr(&ia6->ia_ifa); 385 return (error); 386 } 387 dohooks(ifp->if_addrhooks, 0); 388 389 return (0); 390} 391 392int 393in6_ifattach_loopback(struct ifnet *ifp) 394{ 395 struct in6_addr in6 = in6addr_loopback; 396 struct in6_aliasreq ifra; 397 398 KASSERT(ifp->if_flags & IFF_LOOPBACK); 399 400 if (in6ifa_ifpwithaddr(ifp, &in6) != NULL) 401 return (0); 402 403 bzero(&ifra, sizeof(ifra)); 404 strncpy(ifra.ifra_name, ifp->if_xname, sizeof(ifra.ifra_name)); 405 ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6); 406 ifra.ifra_prefixmask.sin6_family = AF_INET6; 407 ifra.ifra_prefixmask.sin6_addr = in6mask128; 408 409 /* 410 * Always initialize ia_dstaddr (= broadcast address) to loopback 411 * address. Follows IPv4 practice - see in_ifinit(). 412 */ 413 ifra.ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6); 414 ifra.ifra_dstaddr.sin6_family = AF_INET6; 415 ifra.ifra_dstaddr.sin6_addr = in6addr_loopback; 416 417 ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6); 418 ifra.ifra_addr.sin6_family = AF_INET6; 419 ifra.ifra_addr.sin6_addr = in6addr_loopback; 420 421 /* the loopback address should NEVER expire. */ 422 ifra.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME; 423 ifra.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME; 424 425 /* 426 * We are sure that this is a newly assigned address, so we can set 427 * NULL to the 3rd arg. 428 */ 429 return (in6_update_ifa(ifp, &ifra, NULL)); 430} 431 432/* 433 * XXX multiple loopback interface needs more care. for instance, 434 * nodelocal address needs to be configured onto only one of them. 435 * XXX multiple link-local address case 436 */ 437int 438in6_ifattach(struct ifnet *ifp) 439{ 440 /* some of the interfaces are inherently not IPv6 capable */ 441 switch (ifp->if_type) { 442 case IFT_BRIDGE: 443 case IFT_ENC: 444 case IFT_PFLOG: 445 case IFT_PFSYNC: 446 return (0); 447 } 448 449 /* 450 * if link mtu is too small, don't try to configure IPv6. 451 * remember there could be some link-layer that has special 452 * fragmentation logic. 453 */ 454 if (ifp->if_mtu < IPV6_MMTU) 455 return (EINVAL); 456 457 if ((ifp->if_flags & IFF_MULTICAST) == 0) 458 return (EINVAL); 459 460 /* 461 * Assign loopback address if this lo(4) interface is the 462 * default for its rdomain. 463 */ 464 if ((ifp->if_flags & IFF_LOOPBACK) && 465 (ifp->if_index == rtable_loindex(ifp->if_rdomain))) { 466 int error; 467 468 error = in6_ifattach_loopback(ifp); 469 if (error) 470 return (error); 471 } 472 473 /* Assign a link-local address, if there's none. */ 474 if (in6ifa_ifpforlinklocal(ifp, 0) == NULL) { 475 if (in6_ifattach_linklocal(ifp, NULL) != 0) { 476 /* failed to assign linklocal address. bark? */ 477 } 478 } 479 480 return (0); 481} 482 483/* 484 * NOTE: in6_ifdetach() does not support loopback if at this moment. 485 */ 486void 487in6_ifdetach(struct ifnet *ifp) 488{ 489 struct ifaddr *ifa, *next; 490 struct rtentry *rt; 491 struct sockaddr_in6 sin6; 492 493#ifdef MROUTING 494 /* remove ip6_mrouter stuff */ 495 ip6_mrouter_detach(ifp); 496#endif 497 498 /* nuke any of IPv6 addresses we have */ 499 TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrlist, ifa_list, next) { 500 if (ifa->ifa_addr->sa_family != AF_INET6) 501 continue; 502 in6_purgeaddr(ifa); 503 dohooks(ifp->if_addrhooks, 0); 504 } 505 506 /* 507 * Remove neighbor management table. Must be called after 508 * purging addresses. 509 */ 510 nd6_purge(ifp); 511 512 /* remove route to interface local allnodes multicast (ff01::1) */ 513 bzero(&sin6, sizeof(sin6)); 514 sin6.sin6_len = sizeof(struct sockaddr_in6); 515 sin6.sin6_family = AF_INET6; 516 sin6.sin6_addr = in6addr_intfacelocal_allnodes; 517 sin6.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 518 rt = rtalloc(sin6tosa(&sin6), 0, ifp->if_rdomain); 519 if (rt && rt->rt_ifidx == ifp->if_index) { 520 rtdeletemsg(rt, ifp, ifp->if_rdomain); 521 rtfree(rt); 522 } 523 524 /* remove route to link-local allnodes multicast (ff02::1) */ 525 bzero(&sin6, sizeof(sin6)); 526 sin6.sin6_len = sizeof(struct sockaddr_in6); 527 sin6.sin6_family = AF_INET6; 528 sin6.sin6_addr = in6addr_linklocal_allnodes; 529 sin6.sin6_addr.s6_addr16[1] = htons(ifp->if_index); 530 rt = rtalloc(sin6tosa(&sin6), 0, ifp->if_rdomain); 531 if (rt && rt->rt_ifidx == ifp->if_index) { 532 rtdeletemsg(rt, ifp, ifp->if_rdomain); 533 rtfree(rt); 534 } 535 536 if (ifp->if_xflags & IFXF_AUTOCONF6) 537 ifp->if_xflags &= ~IFXF_AUTOCONF6; 538} 539