nd6_nbr.c revision 1.8
1 /* $NetBSD: nd6_nbr.c,v 1.8 1999/09/19 21:31:35 is Exp $ */ 2 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 32 #if (defined(__FreeBSD__) && __FreeBSD__ >= 3) || defined(__NetBSD__) 33 #include "opt_inet.h" 34 #ifdef __NetBSD__ /*XXX*/ 35 #include "opt_ipsec.h" 36 #endif 37 #endif 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/malloc.h> 42 #include <sys/mbuf.h> 43 #include <sys/socket.h> 44 #include <sys/sockio.h> 45 #include <sys/time.h> 46 #include <sys/kernel.h> 47 #include <sys/errno.h> 48 #if !defined(__FreeBSD__) || __FreeBSD__ < 3 49 #include <sys/ioctl.h> 50 #endif 51 #include <sys/syslog.h> 52 #include <sys/queue.h> 53 54 #include <net/if.h> 55 #include <net/if_types.h> 56 #include <net/if_dl.h> 57 #include <net/route.h> 58 59 #include <netinet/in.h> 60 #include <netinet/in_var.h> 61 #include <netinet6/in6_var.h> 62 #include <netinet6/ip6.h> 63 #include <netinet6/ip6_var.h> 64 #include <netinet6/nd6.h> 65 #include <netinet6/icmp6.h> 66 67 #define SDL(s) ((struct sockaddr_dl *)s) 68 69 #if 0 70 extern struct timeval time; 71 #endif 72 73 struct dadq; 74 static struct dadq *nd6_dad_find __P((struct ifaddr *)); 75 static void nd6_dad_timer __P((struct ifaddr *)); 76 static void nd6_dad_ns_input __P((struct ifaddr *)); 77 static void nd6_dad_na_input __P((struct ifaddr *)); 78 79 /* ignore NS in DAD - specwise incorrect, */ 80 int dad_ignore_ns = 0; 81 82 /* 83 * Input an Neighbor Solicitation Message. 84 * 85 * Based on RFC 2461 86 * Based on RFC 2462 (duplicated address detection) 87 * 88 * XXX proxy advertisement 89 */ 90 void 91 nd6_ns_input(m, off, icmp6len) 92 struct mbuf *m; 93 int off, icmp6len; 94 { 95 struct ifnet *ifp = m->m_pkthdr.rcvif; 96 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 97 struct nd_neighbor_solicit *nd_ns 98 = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 99 struct in6_addr saddr6 = ip6->ip6_src; 100 struct in6_addr daddr6 = ip6->ip6_dst; 101 struct in6_addr taddr6 = nd_ns->nd_ns_target; 102 struct in6_addr myaddr6; 103 char *lladdr = NULL; 104 struct ifaddr *ifa; 105 int lladdrlen = 0; 106 int anycast = 0, proxy = 0, tentative = 0; 107 int tlladdr; 108 union nd_opts ndopts; 109 110 if (ip6->ip6_hlim != 255) { 111 log(LOG_ERR, 112 "nd6_ns_input: invalid hlim %d\n", ip6->ip6_hlim); 113 return; 114 } 115 116 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 117 /* dst has to be solicited node multicast address. */ 118 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL 119 /*don't check ifindex portion*/ 120 && daddr6.s6_addr32[1] == 0 121 && daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE 122 && daddr6.s6_addr8[12] == 0xff) { 123 ; /*good*/ 124 } else { 125 log(LOG_INFO, "nd6_ns_input: bad DAD packet " 126 "(wrong ip6 dst)\n"); 127 goto bad; 128 } 129 } 130 131 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 132 log(LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"); 133 goto bad; 134 } 135 136 if (IN6_IS_SCOPE_LINKLOCAL(&taddr6)) 137 taddr6.s6_addr16[1] = htons(ifp->if_index); 138 139 icmp6len -= sizeof(*nd_ns); 140 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 141 if (nd6_options(&ndopts) < 0) { 142 log(LOG_INFO, "nd6_ns_input: invalid ND option, ignored\n"); 143 goto bad; 144 } 145 146 if (ndopts.nd_opts_src_lladdr) { 147 lladdr = (char *)(ndopts.nd_opts_src_lladdr +1); 148 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 149 } 150 151 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 152 log(LOG_INFO, "nd6_ns_input: bad DAD packet " 153 "(link-layer address option)\n"); 154 goto bad; 155 } 156 157 /* 158 * Attaching target link-layer address to the NA? 159 * (RFC 2461 7.2.4) 160 * 161 * NS IP dst is unicast/anycast MUST NOT add 162 * NS IP dst is solicited-node multicast MUST add 163 * 164 * In implementation, we add target link-layer address by default. 165 * We do not add one in MUST NOT cases. 166 */ 167 #if 0 /* too much! */ 168 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &daddr6); 169 if (ifa && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)) 170 tlladdr = 0; 171 else 172 #endif 173 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 174 tlladdr = 0; 175 else 176 tlladdr = 1; 177 178 /* 179 * Target address (taddr6) must be either: 180 * (1) Valid unicast/anycast address for my receiving interface, 181 * (2) Unicast address for which I'm offering proxy service, or 182 * (3) "tentative" address on which DAD is being performed. 183 */ 184 /* (1) and (3) check. */ 185 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 186 187 /* (2) check. */ 188 if (!ifa && nd6_proxyall) { 189 struct rtentry *rt; 190 struct sockaddr_in6 tsin6; 191 192 bzero(&tsin6, sizeof tsin6); 193 tsin6.sin6_len = sizeof(struct sockaddr_in6); 194 tsin6.sin6_family = AF_INET6; 195 tsin6.sin6_addr = taddr6; 196 197 rt = rtalloc1((struct sockaddr *)&tsin6, 0 198 #ifdef __FreeBSD__ 199 , 0 200 #endif /* __FreeBSD__ */ 201 ); 202 if (rt && rt->rt_ifp != ifp) { 203 /* 204 * search link local addr for ifp, and use it for 205 * proxy NA. 206 */ 207 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp); 208 if (ifa) 209 proxy = 1; 210 } 211 rtfree(rt); 212 } 213 if (!ifa) { 214 /* 215 * We've got a NS packet, and we don't have that adddress 216 * assigned for us. We MUST silently ignore it. 217 * See RFC2461 7.2.3. 218 */ 219 return; 220 } 221 myaddr6 = IFA_IN6(ifa); 222 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 223 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 224 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 225 return; 226 227 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 228 log(LOG_INFO, 229 "nd6_ns_input: lladdrlen mismatch for %s " 230 "(if %d, NS packet %d)\n", 231 ip6_sprintf(&taddr6), ifp->if_addrlen, lladdrlen - 2); 232 } 233 234 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 235 log(LOG_INFO, 236 "nd6_ns_input: duplicate IP6 address %s\n", 237 ip6_sprintf(&saddr6)); 238 return; 239 } 240 241 /* 242 * We have neighbor solicitation packet, with target address equals to 243 * one of my tentative address. 244 * 245 * src addr how to process? 246 * --- --- 247 * multicast of course, invalid (rejected in ip6_input) 248 * unicast somebody is doing address resolution -> ignore 249 * unspec dup address detection 250 * 251 * The processing is defined in RFC 2462. 252 */ 253 if (tentative) { 254 /* 255 * If source address is unspecified address, it is for 256 * duplicated address detection. 257 * 258 * If not, the packet is for addess resolution; 259 * silently ignore it. 260 */ 261 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 262 nd6_dad_ns_input(ifa); 263 264 return; 265 } 266 267 /* 268 * If the source address is unspecified address, entries must not 269 * be created or updated. 270 * It looks that sender is performing DAD. Output NA toward 271 * all-node multicast address, to tell the sender that I'm using 272 * the address. 273 * S bit ("solicited") must be zero. 274 */ 275 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 276 saddr6 = in6addr_linklocal_allnodes; 277 saddr6.s6_addr16[1] = htons(ifp->if_index); 278 nd6_na_output(ifp, &saddr6, &taddr6, 279 ((anycast || proxy || !tlladdr) 280 ? 0 : ND_NA_FLAG_OVERRIDE) 281 | (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0), 282 tlladdr); 283 return; 284 } 285 286 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_NEIGHBOR_SOLICIT, 0); 287 288 nd6_na_output(ifp, &saddr6, &taddr6, 289 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) 290 | (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0) 291 | ND_NA_FLAG_SOLICITED, 292 tlladdr); 293 return; 294 295 bad: 296 log(LOG_ERR, "nd6_ns_input: src=%s\n", ip6_sprintf(&saddr6)); 297 log(LOG_ERR, "nd6_ns_input: dst=%s\n", ip6_sprintf(&daddr6)); 298 log(LOG_ERR, "nd6_ns_input: tgt=%s\n", ip6_sprintf(&taddr6)); 299 return; 300 } 301 302 /* 303 * Output an Neighbor Solicitation Message. Caller specifies: 304 * - ICMP6 header source IP6 address 305 * - ND6 header target IP6 address 306 * - ND6 header source datalink address 307 * 308 * Based on RFC 2461 309 * Based on RFC 2462 (duplicated address detection) 310 */ 311 void 312 nd6_ns_output(ifp, daddr6, taddr6, ln, dad) 313 struct ifnet *ifp; 314 struct in6_addr *daddr6, *taddr6; 315 struct llinfo_nd6 *ln; /* for source address determination */ 316 int dad; /* duplicated address detection */ 317 { 318 struct mbuf *m; 319 struct ip6_hdr *ip6; 320 struct nd_neighbor_solicit *nd_ns; 321 struct in6_ifaddr *ia = NULL; 322 struct ip6_moptions im6o; 323 int icmp6len; 324 caddr_t mac; 325 326 if (IN6_IS_ADDR_MULTICAST(taddr6)) 327 return; 328 329 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 330 return; 331 332 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 333 m->m_flags |= M_MCAST; 334 im6o.im6o_multicast_ifp = ifp; 335 im6o.im6o_multicast_hlim = 255; 336 im6o.im6o_multicast_loop = 0; 337 } 338 339 icmp6len = sizeof(*nd_ns); 340 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 341 MH_ALIGN(m, m->m_len + 16); /* 1+1+6 is enought. but just in case */ 342 343 /* fill neighbor solicitation packet */ 344 ip6 = mtod(m, struct ip6_hdr *); 345 ip6->ip6_flow = 0; 346 ip6->ip6_vfc = IPV6_VERSION; 347 /* ip6->ip6_plen will be set later */ 348 ip6->ip6_nxt = IPPROTO_ICMPV6; 349 ip6->ip6_hlim = 255; 350 if (daddr6) 351 ip6->ip6_dst = *daddr6; 352 else { 353 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 354 ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index); 355 ip6->ip6_dst.s6_addr32[1] = 0; 356 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 357 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 358 ip6->ip6_dst.s6_addr8[12] = 0xff; 359 } 360 if (!dad) { 361 #if 0 /* KAME way, exact address scope match */ 362 /* 363 * Select a source whose scope is the same as that of the dest. 364 * Typically, the dest is link-local solicitation multicast 365 * (i.e. neighbor discovery) or link-local/global unicast 366 * (i.e. neighbor un-reachability detection). 367 */ 368 ia = in6_ifawithifp(ifp, &ip6->ip6_dst); 369 if (ia == NULL) { 370 m_freem(m); 371 return; 372 } 373 ip6->ip6_src = ia->ia_addr.sin6_addr; 374 #else /* spec-wise correct */ 375 /* 376 * RFC2461 7.2.2: 377 * "If the source address of the packet prompting the 378 * solicitation is the same as one of the addresses assigned 379 * to the outgoing interface, that address SHOULD be placed 380 * in the IP Source Address of the outgoing solicitation. 381 * Otherwise, any one of the addresses assigned to the 382 * interface should be used." 383 * 384 * We use the source address for the prompting packet 385 * (saddr6), if: 386 * - saddr6 is given from the caller (by giving "ln"), and 387 * - saddr6 belongs to the outgoing interface. 388 * Otherwise, we perform a scope-wise match. 389 */ 390 struct ip6_hdr *hip6; /*hold ip6*/ 391 struct in6_addr *saddr6; 392 393 if (ln && ln->ln_hold) { 394 hip6 = mtod(ln->ln_hold, struct ip6_hdr *); 395 /* XXX pullup? */ 396 if (sizeof(*hip6) < ln->ln_hold->m_len) 397 saddr6 = &hip6->ip6_src; 398 else 399 saddr6 = NULL; 400 } else 401 saddr6 = NULL; 402 if (saddr6 && in6ifa_ifpwithaddr(ifp, saddr6)) 403 bcopy(saddr6, &ip6->ip6_src, sizeof(*saddr6)); 404 else { 405 ia = in6_ifawithifp(ifp, &ip6->ip6_dst); 406 if (ia == NULL) { 407 m_freem(m); /*XXX*/ 408 return; 409 } 410 ip6->ip6_src = ia->ia_addr.sin6_addr; 411 } 412 #endif 413 } else { 414 /* 415 * Source address for DAD packet must always be IPv6 416 * unspecified address. (0::0) 417 */ 418 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 419 } 420 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 421 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 422 nd_ns->nd_ns_code = 0; 423 nd_ns->nd_ns_reserved = 0; 424 nd_ns->nd_ns_target = *taddr6; 425 426 if (IN6_IS_SCOPE_LINKLOCAL(&nd_ns->nd_ns_target)) 427 nd_ns->nd_ns_target.s6_addr16[1] = 0; 428 429 /* 430 * Add source link-layer address option. 431 * 432 * spec implementation 433 * --- --- 434 * DAD packet MUST NOT do not add the option 435 * there's no link layer address: 436 * impossible do not add the option 437 * there's link layer address: 438 * Multicast NS MUST add one add the option 439 * Unicast NS SHOULD add one add the option 440 */ 441 if (!dad && (mac = nd6_ifptomac(ifp))) { 442 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 443 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 444 /* 8 byte alignments... */ 445 optlen = (optlen + 7) & ~7; 446 447 m->m_pkthdr.len += optlen; 448 m->m_len += optlen; 449 icmp6len += optlen; 450 bzero((caddr_t)nd_opt, optlen); 451 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 452 nd_opt->nd_opt_len = optlen >> 3; 453 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 454 } 455 456 ip6->ip6_plen = htons((u_short)icmp6len); 457 nd_ns->nd_ns_cksum = 0; 458 nd_ns->nd_ns_cksum 459 = in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 460 461 #ifdef IPSEC 462 m->m_pkthdr.rcvif = NULL; 463 #endif /*IPSEC*/ 464 ip6_output(m, NULL, NULL, dad ? IPV6_DADOUTPUT : 0, &im6o); 465 icmp6stat.icp6s_outhist[ND_NEIGHBOR_SOLICIT]++; 466 } 467 468 /* 469 * Neighbor advertisement input handling. 470 * 471 * Based on RFC 2461 472 * Based on RFC 2462 (duplicated address detection) 473 */ 474 void 475 nd6_na_input(m, off, icmp6len) 476 struct mbuf *m; 477 int off, icmp6len; 478 { 479 struct ifnet *ifp = m->m_pkthdr.rcvif; 480 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 481 struct nd_neighbor_advert *nd_na 482 = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 483 #if 0 484 struct in6_addr saddr6 = ip6->ip6_src; 485 #endif 486 struct in6_addr daddr6 = ip6->ip6_dst; 487 struct in6_addr taddr6 = nd_na->nd_na_target; 488 int flags = nd_na->nd_na_flags_reserved; 489 int is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 490 int is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 491 int is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 492 char *lladdr = NULL; 493 int lladdrlen = 0; 494 struct ifaddr *ifa; 495 struct llinfo_nd6 *ln; 496 struct rtentry *rt; 497 struct sockaddr_dl *sdl; 498 union nd_opts ndopts; 499 500 if (ip6->ip6_hlim != 255) { 501 log(LOG_ERR, 502 "nd6_na_input: invalid hlim %d\n", ip6->ip6_hlim); 503 return; 504 } 505 506 if (IN6_IS_SCOPE_LINKLOCAL(&taddr6)) 507 taddr6.s6_addr16[1] = htons(ifp->if_index); 508 509 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 510 log(LOG_ERR, 511 "nd6_na_input: invalid target address %s\n", 512 ip6_sprintf(&taddr6)); 513 return; 514 } 515 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 516 if (is_solicited) { 517 log(LOG_ERR, 518 "nd6_na_input: a solicited adv is multicasted\n"); 519 return; 520 } 521 522 icmp6len -= sizeof(*nd_na); 523 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 524 if (nd6_options(&ndopts) < 0) { 525 log(LOG_INFO, "nd6_na_input: invalid ND option, ignored\n"); 526 return; 527 } 528 529 if (ndopts.nd_opts_tgt_lladdr) { 530 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 531 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 532 } 533 534 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 535 536 /* 537 * Target address matches one of my interface address. 538 * 539 * If my address is tentative, this means that there's somebody 540 * already using the same address as mine. This indicates DAD failure. 541 * This is defined in RFC 2462. 542 * 543 * Otherwise, process as defined in RFC 2461. 544 */ 545 if (ifa 546 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 547 nd6_dad_na_input(ifa); 548 return; 549 } 550 551 /* Just for safety, maybe unnecessery. */ 552 if (ifa) { 553 log(LOG_ERR, 554 "nd6_na_input: duplicate IP6 address %s\n", 555 ip6_sprintf(&taddr6)); 556 return; 557 } 558 559 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 560 log(LOG_INFO, 561 "nd6_na_input: lladdrlen mismatch for %s " 562 "(if %d, NA packet %d)\n", 563 ip6_sprintf(&taddr6), ifp->if_addrlen, lladdrlen - 2); 564 } 565 566 /* 567 * If no neighbor cache entry is found, NA SHOULD silently be discarded. 568 */ 569 rt = nd6_lookup(&taddr6, 0, ifp); 570 if ((rt == NULL) || 571 ((ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) || 572 ((sdl = SDL(rt->rt_gateway)) == NULL)) 573 return; 574 575 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 576 /* 577 * If the link-layer has address, and no lladdr option came, 578 * discard the packet. 579 */ 580 if (ifp->if_addrlen && !lladdr) 581 return; 582 583 /* 584 * Record link-layer address, and update the state. 585 */ 586 sdl->sdl_alen = ifp->if_addrlen; 587 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); 588 if (is_solicited) { 589 ln->ln_state = ND6_LLINFO_REACHABLE; 590 if (ln->ln_expire) 591 #if !defined(__FreeBSD__) || __FreeBSD__ < 3 592 ln->ln_expire = time.tv_sec + 593 #else 594 ln->ln_expire = time_second + 595 #endif 596 nd_ifinfo[rt->rt_ifp->if_index].reachable; 597 } else 598 ln->ln_state = ND6_LLINFO_STALE; 599 ln->ln_router = is_router; 600 } else { 601 int llchange; 602 603 /* 604 * Check if the link-layer address has changed or not. 605 */ 606 if (!lladdr) 607 llchange = 0; 608 else { 609 if (sdl->sdl_alen) { 610 if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen)) 611 llchange = 1; 612 else 613 llchange = 0; 614 } else 615 llchange = 1; 616 } 617 618 /* 619 * This is VERY complex. Look at it with care. 620 * 621 * override solicit lladdr llchange action 622 * (L: record lladdr) 623 * 624 * 0 0 n -- (2c) 625 * 0 0 y n (2b) L 626 * 0 0 y y (1) REACHABLE->STALE 627 * 0 1 n -- (2c) *->REACHABLE 628 * 0 1 y n (2b) L *->REACHABLE 629 * 0 1 y y (1) REACHABLE->STALE 630 * 1 0 n -- (2a) 631 * 1 0 y n (2a) L 632 * 1 0 y y (2a) L *->STALE 633 * 1 1 n -- (2a) *->REACHABLE 634 * 1 1 y n (2a) L *->REACHABLE 635 * 1 1 y y (2a) L *->REACHABLE 636 */ 637 if (!is_override && (lladdr && llchange)) { /* (1) */ 638 /* 639 * If state is REACHABLE, make it STALE. 640 * no other updates should be done. 641 */ 642 if (ln->ln_state == ND6_LLINFO_REACHABLE) 643 ln->ln_state = ND6_LLINFO_STALE; 644 return; 645 } else if (is_override /* (2a) */ 646 || (!is_override && (lladdr && !llchange)) /* (2b) */ 647 || !lladdr) { /* (2c) */ 648 /* 649 * Update link-local address, if any. 650 */ 651 if (lladdr) { 652 sdl->sdl_alen = ifp->if_addrlen; 653 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); 654 } 655 656 /* 657 * If solicited, make the state REACHABLE. 658 * If not solicited and the link-layer address was 659 * changed, make it STALE. 660 */ 661 if (is_solicited) { 662 ln->ln_state = ND6_LLINFO_REACHABLE; 663 if (ln->ln_expire) { 664 #if !defined(__FreeBSD__) || __FreeBSD__ < 3 665 ln->ln_expire = time.tv_sec + 666 #else 667 ln->ln_expire = time_second + 668 #endif 669 nd_ifinfo[ifp->if_index].reachable; 670 } 671 } else { 672 if (lladdr && llchange) 673 ln->ln_state = ND6_LLINFO_STALE; 674 } 675 } 676 677 if (ln->ln_router && !is_router) { 678 /* 679 * The peer dropped the router flag. 680 * Remove the sender from the Default Router List and 681 * update the Destination Cache entries. 682 */ 683 struct nd_defrouter *dr; 684 struct in6_addr *in6; 685 int s; 686 687 in6 = &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr; 688 s = splsoftnet(); 689 dr = defrouter_lookup(in6, rt->rt_ifp); 690 if (dr) 691 defrtrlist_del(dr); 692 else if (!ip6_forwarding && ip6_accept_rtadv) { 693 /* 694 * Even if the neighbor is not in the default 695 * router list, the neighbor may be used 696 * as a next hop for some destinations 697 * (e.g. redirect case). So we must 698 * call rt6_flush explicitly. 699 */ 700 rt6_flush(&ip6->ip6_src, rt->rt_ifp); 701 } 702 splx(s); 703 } 704 ln->ln_router = is_router; 705 } 706 rt->rt_flags &= ~RTF_REJECT; 707 ln->ln_asked = 0; 708 if (ln->ln_hold) { 709 (*ifp->if_output)(ifp, ln->ln_hold, rt_key(rt), rt); 710 ln->ln_hold = 0; 711 } 712 } 713 714 /* 715 * Neighbor advertisement output handling. 716 * 717 * Based on RFC 2461 718 * 719 * XXX NA delay for anycast address is not implemented yet 720 * (RFC 2461 7.2.7) 721 * XXX proxy advertisement? 722 */ 723 void 724 nd6_na_output(ifp, daddr6, taddr6, flags, tlladdr) 725 struct ifnet *ifp; 726 struct in6_addr *daddr6, *taddr6; 727 u_long flags; 728 int tlladdr; /* 1 if include target link-layer address */ 729 { 730 struct mbuf *m; 731 struct ip6_hdr *ip6; 732 struct nd_neighbor_advert *nd_na; 733 struct in6_ifaddr *ia = NULL; 734 struct ip6_moptions im6o; 735 int icmp6len; 736 caddr_t mac; 737 738 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 739 return; 740 741 if (IN6_IS_ADDR_MULTICAST(daddr6)) { 742 m->m_flags |= M_MCAST; 743 im6o.im6o_multicast_ifp = ifp; 744 im6o.im6o_multicast_hlim = 255; 745 im6o.im6o_multicast_loop = 0; 746 } 747 748 icmp6len = sizeof(*nd_na); 749 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 750 MH_ALIGN(m, m->m_len + 16); /* 1+1+6 is enough. but just in case */ 751 752 /* fill neighbor advertisement packet */ 753 ip6 = mtod(m, struct ip6_hdr *); 754 ip6->ip6_flow = 0; 755 ip6->ip6_vfc = IPV6_VERSION; 756 ip6->ip6_nxt = IPPROTO_ICMPV6; 757 ip6->ip6_hlim = 255; 758 if (IN6_IS_ADDR_UNSPECIFIED(daddr6)) { 759 /* reply to DAD */ 760 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 761 ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index); 762 ip6->ip6_dst.s6_addr32[1] = 0; 763 ip6->ip6_dst.s6_addr32[2] = 0; 764 ip6->ip6_dst.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 765 flags &= ~ND_NA_FLAG_SOLICITED; 766 } else 767 ip6->ip6_dst = *daddr6; 768 769 /* 770 * Select a source whose scope is the same as that of the dest. 771 */ 772 ia = in6_ifawithifp(ifp, &ip6->ip6_dst); 773 if (ia == NULL) { 774 m_freem(m); 775 return; 776 } 777 ip6->ip6_src = ia->ia_addr.sin6_addr; 778 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 779 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 780 nd_na->nd_na_code = 0; 781 nd_na->nd_na_target = *taddr6; 782 if (IN6_IS_SCOPE_LINKLOCAL(&nd_na->nd_na_target)) 783 nd_na->nd_na_target.s6_addr16[1] = 0; 784 785 /* 786 * "tlladdr" indicates NS's condition for adding tlladdr or not. 787 * see nd6_ns_input() for details. 788 * Basically, if NS packet is sent to unicast/anycast addr, 789 * target lladdr option SHOULD NOT be included. 790 */ 791 if (tlladdr && (mac = nd6_ifptomac(ifp))) { 792 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 793 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 794 795 /* roundup to 8 bytes alignment! */ 796 optlen = (optlen + 7) & ~7; 797 798 m->m_pkthdr.len += optlen; 799 m->m_len += optlen; 800 icmp6len += optlen; 801 bzero((caddr_t)nd_opt, optlen); 802 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 803 nd_opt->nd_opt_len = optlen >> 3; 804 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 805 } else 806 flags &= ~ND_NA_FLAG_OVERRIDE; 807 808 ip6->ip6_plen = htons((u_short)icmp6len); 809 nd_na->nd_na_flags_reserved = flags; 810 nd_na->nd_na_cksum = 0; 811 nd_na->nd_na_cksum = 812 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 813 814 #ifdef IPSEC 815 m->m_pkthdr.rcvif = NULL; 816 #endif /*IPSEC*/ 817 ip6_output(m, NULL, NULL, 0, &im6o); 818 icmp6stat.icp6s_outhist[ND_NEIGHBOR_ADVERT]++; 819 } 820 821 caddr_t 822 nd6_ifptomac(ifp) 823 struct ifnet *ifp; 824 { 825 switch (ifp->if_type) { 826 case IFT_ARCNET: 827 case IFT_ETHER: 828 case IFT_FDDI: 829 #ifdef __NetBSD__ 830 return LLADDR(ifp->if_sadl); 831 #else 832 return ((caddr_t)(ifp + 1)); 833 #endif 834 break; 835 default: 836 return NULL; 837 } 838 } 839 840 TAILQ_HEAD(dadq_head, dadq); 841 struct dadq { 842 TAILQ_ENTRY(dadq) dad_list; 843 struct ifaddr *dad_ifa; 844 int dad_count; /* max NS to send */ 845 int dad_ns_ocount; /* NS sent so far */ 846 int dad_ns_icount; 847 int dad_na_icount; 848 #if defined(__FreeBSD__) && __FreeBSD__ >= 3 849 struct callout_handle dad_timer; 850 #endif 851 }; 852 853 static struct dadq_head dadq; 854 855 static struct dadq * 856 nd6_dad_find(ifa) 857 struct ifaddr *ifa; 858 { 859 struct dadq *dp; 860 861 for (dp = dadq.tqh_first; dp; dp = dp->dad_list.tqe_next) { 862 if (dp->dad_ifa == ifa) 863 return dp; 864 } 865 return NULL; 866 } 867 868 /* 869 * Start Duplicated Address Detection (DAD) for specified interface address. 870 */ 871 void 872 nd6_dad_start(ifa, tick) 873 struct ifaddr *ifa; 874 int *tick; /* minimum delay ticks for IFF_UP event */ 875 { 876 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 877 struct dadq *dp; 878 static int dad_init = 0; 879 880 if (!dad_init) { 881 TAILQ_INIT(&dadq); 882 dad_init++; 883 } 884 885 /* 886 * If we don't need DAD, don't do it. 887 * There are several cases: 888 * - DAD is disabled (ip6_dad_count == 0) 889 * - the interface address is anycast 890 */ 891 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 892 printf("nd6_dad_start: called with non-tentative address " 893 "%s(%s)\n", 894 ip6_sprintf(&ia->ia_addr.sin6_addr), 895 ifa->ifa_ifp ? ifa->ifa_ifp->if_xname : "???"); 896 return; 897 } 898 if (ia->ia6_flags & IN6_IFF_ANYCAST) { 899 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 900 return; 901 } 902 if (!ip6_dad_count) { 903 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 904 return; 905 } 906 if (!ifa->ifa_ifp) 907 panic("nd6_dad_start: ifa->ifa_ifp == NULL"); 908 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 909 return; 910 if (nd6_dad_find(ifa) != NULL) { 911 /* DAD already in progress */ 912 return; 913 } 914 915 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT); 916 if (dp == NULL) { 917 printf("nd6_dad_start: memory allocation failed for " 918 "%s(%s)\n", 919 ip6_sprintf(&ia->ia_addr.sin6_addr), 920 ifa->ifa_ifp ? ifa->ifa_ifp->if_xname : "???"); 921 return; 922 } 923 bzero(dp, sizeof(*dp)); 924 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); 925 926 /* XXXJRT This is probably a purely debugging message. */ 927 printf("%s: starting DAD for %s\n", ifa->ifa_ifp->if_xname, 928 ip6_sprintf(&ia->ia_addr.sin6_addr)); 929 930 /* 931 * Send NS packet for DAD, ip6_dad_count times. 932 * Note that we must delay the first transmission, if this is the 933 * first packet to be sent from the interface after interface 934 * (re)initialization. 935 */ 936 dp->dad_ifa = ifa; 937 ifa->ifa_refcnt++; /*just for safety*/ 938 dp->dad_count = ip6_dad_count; 939 dp->dad_ns_icount = dp->dad_na_icount = 0; 940 dp->dad_ns_ocount = 0; 941 if (!tick) { 942 dp->dad_ns_ocount++; 943 nd6_ns_output(ifa->ifa_ifp, NULL, &ia->ia_addr.sin6_addr, 944 NULL, 1); 945 #if defined(__FreeBSD__) && __FreeBSD__ >= 3 946 dp->dad_timer = 947 #endif 948 timeout((void (*) __P((void *)))nd6_dad_timer, (void *)ifa, 949 nd_ifinfo[ifa->ifa_ifp->if_index].retrans * hz / 1000); 950 } else { 951 int ntick; 952 953 if (*tick == 0) 954 ntick = random() % (MAX_RTR_SOLICITATION_DELAY * hz); 955 else 956 ntick = *tick + random() % (hz / 2); 957 *tick = ntick; 958 #if defined(__FreeBSD__) && __FreeBSD__ >= 3 959 dp->dad_timer = 960 #endif 961 timeout((void (*) __P((void *)))nd6_dad_timer, (void *)ifa, 962 ntick); 963 } 964 } 965 966 static void 967 nd6_dad_timer(ifa) 968 struct ifaddr *ifa; 969 { 970 int s; 971 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 972 struct dadq *dp; 973 974 s = splsoftnet(); /*XXX*/ 975 976 /* Sanity check */ 977 if (ia == NULL) { 978 printf("nd6_dad_timer: called with null parameter\n"); 979 goto done; 980 } 981 dp = nd6_dad_find(ifa); 982 if (dp == NULL) { 983 printf("nd6_dad_timer: DAD structure not found\n"); 984 goto done; 985 } 986 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 987 printf("nd6_dad_timer: called with duplicated address " 988 "%s(%s)\n", 989 ip6_sprintf(&ia->ia_addr.sin6_addr), 990 ifa->ifa_ifp ? ifa->ifa_ifp->if_xname : "???"); 991 goto done; 992 } 993 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 994 printf("nd6_dad_timer: called with non-tentative address " 995 "%s(%s)\n", 996 ip6_sprintf(&ia->ia_addr.sin6_addr), 997 ifa->ifa_ifp ? ifa->ifa_ifp->if_xname : "???"); 998 goto done; 999 } 1000 1001 /* Need more checks? */ 1002 if (dp->dad_ns_ocount < dp->dad_count) { 1003 /* 1004 * We have more NS to go. Send NS packet for DAD. 1005 */ 1006 dp->dad_ns_ocount++; 1007 nd6_ns_output(ifa->ifa_ifp, NULL, &ia->ia_addr.sin6_addr, 1008 NULL, 1); 1009 #if defined(__FreeBSD__) && __FreeBSD__ >= 3 1010 dp->dad_timer = 1011 #endif 1012 timeout((void (*) __P((void *)))nd6_dad_timer, (void *)ifa, 1013 nd_ifinfo[ifa->ifa_ifp->if_index].retrans * hz / 1000); 1014 } else { 1015 /* 1016 * We have transmitted sufficient number of DAD packets. 1017 * See what we've got. 1018 */ 1019 int duplicate; 1020 1021 duplicate = 0; 1022 1023 if (dp->dad_na_icount) { 1024 /* 1025 * the check is in nd6_dad_na_input(), 1026 * but just in case 1027 */ 1028 duplicate++; 1029 } 1030 1031 if (dp->dad_ns_icount) { 1032 #if 0 /*heuristics*/ 1033 /* 1034 * if 1035 * - we have sent many(?) DAD NS, and 1036 * - the number of NS we sent equals to the 1037 * number of NS we've got, and 1038 * - we've got no NA 1039 * we may have a faulty network card/driver which 1040 * loops back multicasts to myself. 1041 */ 1042 if (3 < dp->dad_count 1043 && dp->dad_ns_icount == dp->dad_count 1044 && dp->dad_na_icount == 0) { 1045 log(LOG_INFO, "DAD questionable for %s(%s): " 1046 "network card loops back multicast?\n", 1047 ip6_sprintf(&ia->ia_addr.sin6_addr), 1048 ifa->ifa_ifp->if_xname); 1049 /* XXX consider it a duplicate or not? */ 1050 /* duplicate++; */ 1051 } else { 1052 /* We've seen NS, means DAD has failed. */ 1053 duplicate++; 1054 } 1055 #else 1056 /* We've seen NS, means DAD has failed. */ 1057 duplicate++; 1058 #endif 1059 } 1060 1061 if (duplicate) { 1062 /* (*dp) will be freed in nd6_dad_duplicated() */ 1063 dp = NULL; 1064 nd6_dad_duplicated(ifa); 1065 } else { 1066 /* 1067 * We are done with DAD. No NA came, no NS came. 1068 * duplicated address found. 1069 */ 1070 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1071 1072 /* XXXJRT This is probably a purely debugging message */ 1073 printf("%s: DAD complete for %s - no duplicates " 1074 "found\n", ifa->ifa_ifp->if_xname, 1075 ip6_sprintf(&ia->ia_addr.sin6_addr)); 1076 1077 TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list); 1078 free(dp, M_IP6NDP); 1079 dp = NULL; 1080 ifa->ifa_refcnt--; 1081 } 1082 } 1083 1084 done: 1085 splx(s); 1086 } 1087 1088 void 1089 nd6_dad_duplicated(ifa) 1090 struct ifaddr *ifa; 1091 { 1092 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1093 struct dadq *dp; 1094 1095 dp = nd6_dad_find(ifa); 1096 if (dp == NULL) { 1097 printf("nd6_dad_duplicated: DAD structure not found\n"); 1098 return; 1099 } 1100 1101 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: %d NS, " 1102 "%d NA\n", ifa->ifa_ifp->if_xname, 1103 ip6_sprintf(&ia->ia_addr.sin6_addr), 1104 dp->dad_ns_icount, dp->dad_na_icount); 1105 1106 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1107 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1108 1109 /* We are done with DAD, with duplicated address found. (failure) */ 1110 untimeout((void (*) __P((void *)))nd6_dad_timer, (void *)ifa 1111 #if defined(__FreeBSD__) && __FreeBSD__ >= 3 1112 , dp->dad_timer 1113 #endif 1114 ); 1115 1116 /* XXXJRT This is probably a purely debugging message. */ 1117 printf("%s: DAD complete for %s - duplicate found\n", 1118 ifa->ifa_ifp->if_xname, ip6_sprintf(&ia->ia_addr.sin6_addr)); 1119 printf("%s: manual intervention required\n", ifa->ifa_ifp->if_xname); 1120 1121 TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list); 1122 free(dp, M_IP6NDP); 1123 dp = NULL; 1124 ifa->ifa_refcnt--; 1125 } 1126 1127 void 1128 nd6_dad_ns_input(ifa) 1129 struct ifaddr *ifa; 1130 { 1131 struct in6_ifaddr *ia; 1132 struct ifnet *ifp; 1133 struct in6_addr *taddr6; 1134 struct dadq *dp; 1135 int duplicate; 1136 1137 if (!ifa) 1138 panic("ifa == NULL in nd6_dad_ns_input"); 1139 1140 ia = (struct in6_ifaddr *)ifa; 1141 ifp = ifa->ifa_ifp; 1142 taddr6 = &ia->ia_addr.sin6_addr; 1143 duplicate = 0; 1144 dp = nd6_dad_find(ifa); 1145 1146 /* 1147 * If it is from myself, ignore this. 1148 */ 1149 if (ifp && (ifp->if_flags & IFF_LOOPBACK)) 1150 return; 1151 1152 /* Quickhack - completely ignore DAD NS packets */ 1153 if (dad_ignore_ns) { 1154 log(LOG_INFO, "nd6_dad_ns_input: ignoring DAD NS packet for " 1155 "address %s(%s)\n", ip6_sprintf(taddr6), 1156 ifa->ifa_ifp->if_xname); 1157 return; 1158 } 1159 1160 /* 1161 * if I'm yet to start DAD, someone else started using this address 1162 * first. I have a duplicate and you win. 1163 */ 1164 if (!dp || dp->dad_ns_ocount == 0) 1165 duplicate++; 1166 1167 /* XXX more checks for loopback situation - see nd6_dad_timer too */ 1168 1169 if (duplicate) { 1170 dp = NULL; /* will be freed in nd6_dad_duplicated() */ 1171 nd6_dad_duplicated(ifa); 1172 } else { 1173 /* 1174 * not sure if I got a duplicate. 1175 * increment ns count and see what happens. 1176 */ 1177 if (dp) 1178 dp->dad_ns_icount++; 1179 } 1180 } 1181 1182 void 1183 nd6_dad_na_input(ifa) 1184 struct ifaddr *ifa; 1185 { 1186 struct dadq *dp; 1187 1188 if (!ifa) 1189 panic("ifa == NULL in nd6_dad_na_input"); 1190 1191 dp = nd6_dad_find(ifa); 1192 if (dp) 1193 dp->dad_na_icount++; 1194 1195 /* remove the address. */ 1196 nd6_dad_duplicated(ifa); 1197 } 1198
Indexes created Sat Sep 27 14:09:57 GMT 2025