nd6_nbr.c revision 226340
1/*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $ 30 */ 31 32#include <sys/cdefs.h> 33__FBSDID("$FreeBSD: head/sys/netinet6/nd6_nbr.c 226340 2011-10-13 13:33:23Z glebius $"); 34 35#include "opt_inet.h" 36#include "opt_inet6.h" 37#include "opt_ipsec.h" 38#include "opt_mpath.h" 39 40#include <sys/param.h> 41#include <sys/systm.h> 42#include <sys/malloc.h> 43#include <sys/lock.h> 44#include <sys/rwlock.h> 45#include <sys/mbuf.h> 46#include <sys/socket.h> 47#include <sys/sockio.h> 48#include <sys/time.h> 49#include <sys/kernel.h> 50#include <sys/errno.h> 51#include <sys/syslog.h> 52#include <sys/queue.h> 53#include <sys/callout.h> 54 55#include <net/if.h> 56#include <net/if_types.h> 57#include <net/if_dl.h> 58#include <net/if_var.h> 59#include <net/route.h> 60#ifdef RADIX_MPATH 61#include <net/radix_mpath.h> 62#endif 63 64#include <netinet/in.h> 65#include <netinet/in_var.h> 66#include <net/if_llatbl.h> 67#define L3_ADDR_SIN6(le) ((struct sockaddr_in6 *) L3_ADDR(le)) 68#include <netinet6/in6_var.h> 69#include <netinet6/in6_ifattach.h> 70#include <netinet/ip6.h> 71#include <netinet6/ip6_var.h> 72#include <netinet6/scope6_var.h> 73#include <netinet6/nd6.h> 74#include <netinet/icmp6.h> 75#include <netinet/ip_carp.h> 76#include <netinet6/send.h> 77 78#define SDL(s) ((struct sockaddr_dl *)s) 79 80struct dadq; 81static struct dadq *nd6_dad_find(struct ifaddr *); 82static void nd6_dad_starttimer(struct dadq *, int); 83static void nd6_dad_stoptimer(struct dadq *); 84static void nd6_dad_timer(struct dadq *); 85static void nd6_dad_ns_output(struct dadq *, struct ifaddr *); 86static void nd6_dad_ns_input(struct ifaddr *); 87static void nd6_dad_na_input(struct ifaddr *); 88 89VNET_DEFINE(int, dad_ignore_ns) = 0; /* ignore NS in DAD - specwise incorrect*/ 90VNET_DEFINE(int, dad_maxtry) = 15; /* max # of *tries* to transmit DAD packet */ 91#define V_dad_ignore_ns VNET(dad_ignore_ns) 92#define V_dad_maxtry VNET(dad_maxtry) 93 94/* 95 * Input a Neighbor Solicitation Message. 96 * 97 * Based on RFC 2461 98 * Based on RFC 2462 (duplicate address detection) 99 */ 100void 101nd6_ns_input(struct mbuf *m, int off, int icmp6len) 102{ 103 struct ifnet *ifp = m->m_pkthdr.rcvif; 104 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 105 struct nd_neighbor_solicit *nd_ns; 106 struct in6_addr saddr6 = ip6->ip6_src; 107 struct in6_addr daddr6 = ip6->ip6_dst; 108 struct in6_addr taddr6; 109 struct in6_addr myaddr6; 110 char *lladdr = NULL; 111 struct ifaddr *ifa = NULL; 112 int lladdrlen = 0; 113 int anycast = 0, proxy = 0, tentative = 0; 114 int tlladdr; 115 int rflag; 116 union nd_opts ndopts; 117 struct sockaddr_dl proxydl; 118 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 119 120 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 121 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 122 rflag = 0; 123#ifndef PULLDOWN_TEST 124 IP6_EXTHDR_CHECK(m, off, icmp6len,); 125 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 126#else 127 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); 128 if (nd_ns == NULL) { 129 ICMP6STAT_INC(icp6s_tooshort); 130 return; 131 } 132#endif 133 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ 134 taddr6 = nd_ns->nd_ns_target; 135 if (in6_setscope(&taddr6, ifp, NULL) != 0) 136 goto bad; 137 138 if (ip6->ip6_hlim != 255) { 139 nd6log((LOG_ERR, 140 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 141 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 142 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 143 goto bad; 144 } 145 146 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 147 /* dst has to be a solicited node multicast address. */ 148 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 149 /* don't check ifindex portion */ 150 daddr6.s6_addr32[1] == 0 && 151 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 152 daddr6.s6_addr8[12] == 0xff) { 153 ; /* good */ 154 } else { 155 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 156 "(wrong ip6 dst)\n")); 157 goto bad; 158 } 159 } else if (!V_nd6_onlink_ns_rfc4861) { 160 struct sockaddr_in6 src_sa6; 161 162 /* 163 * According to recent IETF discussions, it is not a good idea 164 * to accept a NS from an address which would not be deemed 165 * to be a neighbor otherwise. This point is expected to be 166 * clarified in future revisions of the specification. 167 */ 168 bzero(&src_sa6, sizeof(src_sa6)); 169 src_sa6.sin6_family = AF_INET6; 170 src_sa6.sin6_len = sizeof(src_sa6); 171 src_sa6.sin6_addr = saddr6; 172 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 173 nd6log((LOG_INFO, "nd6_ns_input: " 174 "NS packet from non-neighbor\n")); 175 goto bad; 176 } 177 } 178 179 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 180 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 181 goto bad; 182 } 183 184 icmp6len -= sizeof(*nd_ns); 185 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 186 if (nd6_options(&ndopts) < 0) { 187 nd6log((LOG_INFO, 188 "nd6_ns_input: invalid ND option, ignored\n")); 189 /* nd6_options have incremented stats */ 190 goto freeit; 191 } 192 193 if (ndopts.nd_opts_src_lladdr) { 194 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 195 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 196 } 197 198 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 199 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 200 "(link-layer address option)\n")); 201 goto bad; 202 } 203 204 /* 205 * Attaching target link-layer address to the NA? 206 * (RFC 2461 7.2.4) 207 * 208 * NS IP dst is unicast/anycast MUST NOT add 209 * NS IP dst is solicited-node multicast MUST add 210 * 211 * In implementation, we add target link-layer address by default. 212 * We do not add one in MUST NOT cases. 213 */ 214 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 215 tlladdr = 0; 216 else 217 tlladdr = 1; 218 219 /* 220 * Target address (taddr6) must be either: 221 * (1) Valid unicast/anycast address for my receiving interface, 222 * (2) Unicast address for which I'm offering proxy service, or 223 * (3) "tentative" address on which DAD is being performed. 224 */ 225 /* (1) and (3) check. */ 226 if (ifp->if_carp) 227 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 228 if (ifa == NULL) 229 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 230 231 /* (2) check. */ 232 if (ifa == NULL) { 233 struct rtentry *rt; 234 struct sockaddr_in6 tsin6; 235 int need_proxy; 236#ifdef RADIX_MPATH 237 struct route_in6 ro; 238#endif 239 240 bzero(&tsin6, sizeof tsin6); 241 tsin6.sin6_len = sizeof(struct sockaddr_in6); 242 tsin6.sin6_family = AF_INET6; 243 tsin6.sin6_addr = taddr6; 244 245#ifdef RADIX_MPATH 246 bzero(&ro, sizeof(ro)); 247 ro.ro_dst = tsin6; 248 rtalloc_mpath((struct route *)&ro, RTF_ANNOUNCE); 249 rt = ro.ro_rt; 250#else 251 rt = rtalloc1((struct sockaddr *)&tsin6, 0, 0); 252#endif 253 need_proxy = (rt && (rt->rt_flags & RTF_ANNOUNCE) != 0 && 254 rt->rt_gateway->sa_family == AF_LINK); 255 if (rt != NULL) { 256 /* 257 * Make a copy while we can be sure that rt_gateway 258 * is still stable before unlocking to avoid lock 259 * order problems. proxydl will only be used if 260 * proxy will be set in the next block. 261 */ 262 if (need_proxy) 263 proxydl = *SDL(rt->rt_gateway); 264 RTFREE_LOCKED(rt); 265 } 266 if (need_proxy) { 267 /* 268 * proxy NDP for single entry 269 */ 270 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 271 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 272 if (ifa) 273 proxy = 1; 274 } 275 } 276 if (ifa == NULL) { 277 /* 278 * We've got an NS packet, and we don't have that adddress 279 * assigned for us. We MUST silently ignore it. 280 * See RFC2461 7.2.3. 281 */ 282 goto freeit; 283 } 284 myaddr6 = *IFA_IN6(ifa); 285 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 286 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 287 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 288 goto freeit; 289 290 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 291 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 292 "(if %d, NS packet %d)\n", 293 ip6_sprintf(ip6bufs, &taddr6), 294 ifp->if_addrlen, lladdrlen - 2)); 295 goto bad; 296 } 297 298 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 299 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 300 ip6_sprintf(ip6bufs, &saddr6))); 301 goto freeit; 302 } 303 304 /* 305 * We have neighbor solicitation packet, with target address equals to 306 * one of my tentative address. 307 * 308 * src addr how to process? 309 * --- --- 310 * multicast of course, invalid (rejected in ip6_input) 311 * unicast somebody is doing address resolution -> ignore 312 * unspec dup address detection 313 * 314 * The processing is defined in RFC 2462. 315 */ 316 if (tentative) { 317 /* 318 * If source address is unspecified address, it is for 319 * duplicate address detection. 320 * 321 * If not, the packet is for addess resolution; 322 * silently ignore it. 323 */ 324 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 325 nd6_dad_ns_input(ifa); 326 327 goto freeit; 328 } 329 330 /* 331 * If the source address is unspecified address, entries must not 332 * be created or updated. 333 * It looks that sender is performing DAD. Output NA toward 334 * all-node multicast address, to tell the sender that I'm using 335 * the address. 336 * S bit ("solicited") must be zero. 337 */ 338 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 339 struct in6_addr in6_all; 340 341 in6_all = in6addr_linklocal_allnodes; 342 if (in6_setscope(&in6_all, ifp, NULL) != 0) 343 goto bad; 344 nd6_na_output(ifp, &in6_all, &taddr6, 345 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 346 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL); 347 goto freeit; 348 } 349 350 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 351 ND_NEIGHBOR_SOLICIT, 0); 352 353 nd6_na_output(ifp, &saddr6, &taddr6, 354 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 355 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 356 proxy ? (struct sockaddr *)&proxydl : NULL); 357 freeit: 358 if (ifa != NULL) 359 ifa_free(ifa); 360 m_freem(m); 361 return; 362 363 bad: 364 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 365 ip6_sprintf(ip6bufs, &saddr6))); 366 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 367 ip6_sprintf(ip6bufs, &daddr6))); 368 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 369 ip6_sprintf(ip6bufs, &taddr6))); 370 ICMP6STAT_INC(icp6s_badns); 371 if (ifa != NULL) 372 ifa_free(ifa); 373 m_freem(m); 374} 375 376/* 377 * Output a Neighbor Solicitation Message. Caller specifies: 378 * - ICMP6 header source IP6 address 379 * - ND6 header target IP6 address 380 * - ND6 header source datalink address 381 * 382 * Based on RFC 2461 383 * Based on RFC 2462 (duplicate address detection) 384 * 385 * ln - for source address determination 386 * dad - duplicate address detection 387 */ 388void 389nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6, 390 const struct in6_addr *taddr6, struct llentry *ln, int dad) 391{ 392 struct mbuf *m; 393 struct m_tag *mtag; 394 struct ip6_hdr *ip6; 395 struct nd_neighbor_solicit *nd_ns; 396 struct ip6_moptions im6o; 397 int icmp6len; 398 int maxlen; 399 caddr_t mac; 400 struct route_in6 ro; 401 402 if (IN6_IS_ADDR_MULTICAST(taddr6)) 403 return; 404 405 /* estimate the size of message */ 406 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 407 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 408 if (max_linkhdr + maxlen >= MCLBYTES) { 409#ifdef DIAGNOSTIC 410 printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES " 411 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES); 412#endif 413 return; 414 } 415 416 MGETHDR(m, M_DONTWAIT, MT_DATA); 417 if (m && max_linkhdr + maxlen >= MHLEN) { 418 MCLGET(m, M_DONTWAIT); 419 if ((m->m_flags & M_EXT) == 0) { 420 m_free(m); 421 m = NULL; 422 } 423 } 424 if (m == NULL) 425 return; 426 m->m_pkthdr.rcvif = NULL; 427 428 bzero(&ro, sizeof(ro)); 429 430 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 431 m->m_flags |= M_MCAST; 432 im6o.im6o_multicast_ifp = ifp; 433 im6o.im6o_multicast_hlim = 255; 434 im6o.im6o_multicast_loop = 0; 435 } 436 437 icmp6len = sizeof(*nd_ns); 438 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 439 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 440 441 /* fill neighbor solicitation packet */ 442 ip6 = mtod(m, struct ip6_hdr *); 443 ip6->ip6_flow = 0; 444 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 445 ip6->ip6_vfc |= IPV6_VERSION; 446 /* ip6->ip6_plen will be set later */ 447 ip6->ip6_nxt = IPPROTO_ICMPV6; 448 ip6->ip6_hlim = 255; 449 if (daddr6) 450 ip6->ip6_dst = *daddr6; 451 else { 452 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 453 ip6->ip6_dst.s6_addr16[1] = 0; 454 ip6->ip6_dst.s6_addr32[1] = 0; 455 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 456 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 457 ip6->ip6_dst.s6_addr8[12] = 0xff; 458 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 459 goto bad; 460 } 461 if (!dad) { 462 struct ifaddr *ifa; 463 464 /* 465 * RFC2461 7.2.2: 466 * "If the source address of the packet prompting the 467 * solicitation is the same as one of the addresses assigned 468 * to the outgoing interface, that address SHOULD be placed 469 * in the IP Source Address of the outgoing solicitation. 470 * Otherwise, any one of the addresses assigned to the 471 * interface should be used." 472 * 473 * We use the source address for the prompting packet 474 * (saddr6), if: 475 * - saddr6 is given from the caller (by giving "ln"), and 476 * - saddr6 belongs to the outgoing interface. 477 * Otherwise, we perform the source address selection as usual. 478 */ 479 struct in6_addr *hsrc; 480 481 hsrc = NULL; 482 if (ln != NULL) { 483 LLE_RLOCK(ln); 484 if (ln->la_hold != NULL) { 485 struct ip6_hdr *hip6; /* hold ip6 */ 486 487 /* 488 * assuming every packet in la_hold has the same IP 489 * header 490 */ 491 hip6 = mtod(ln->la_hold, struct ip6_hdr *); 492 /* XXX pullup? */ 493 if (sizeof(*hip6) < ln->la_hold->m_len) { 494 ip6->ip6_src = hip6->ip6_src; 495 hsrc = &hip6->ip6_src; 496 } 497 } 498 LLE_RUNLOCK(ln); 499 } 500 if (hsrc && (ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, 501 hsrc)) != NULL) { 502 /* ip6_src set already. */ 503 ifa_free(ifa); 504 } else { 505 int error; 506 struct sockaddr_in6 dst_sa; 507 struct in6_addr src_in; 508 509 bzero(&dst_sa, sizeof(dst_sa)); 510 dst_sa.sin6_family = AF_INET6; 511 dst_sa.sin6_len = sizeof(dst_sa); 512 dst_sa.sin6_addr = ip6->ip6_dst; 513 514 error = in6_selectsrc(&dst_sa, NULL, 515 NULL, &ro, NULL, NULL, &src_in); 516 if (error) { 517 char ip6buf[INET6_ADDRSTRLEN]; 518 nd6log((LOG_DEBUG, 519 "nd6_ns_output: source can't be " 520 "determined: dst=%s, error=%d\n", 521 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), 522 error)); 523 goto bad; 524 } 525 ip6->ip6_src = src_in; 526 } 527 } else { 528 /* 529 * Source address for DAD packet must always be IPv6 530 * unspecified address. (0::0) 531 * We actually don't have to 0-clear the address (we did it 532 * above), but we do so here explicitly to make the intention 533 * clearer. 534 */ 535 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 536 } 537 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 538 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 539 nd_ns->nd_ns_code = 0; 540 nd_ns->nd_ns_reserved = 0; 541 nd_ns->nd_ns_target = *taddr6; 542 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 543 544 /* 545 * Add source link-layer address option. 546 * 547 * spec implementation 548 * --- --- 549 * DAD packet MUST NOT do not add the option 550 * there's no link layer address: 551 * impossible do not add the option 552 * there's link layer address: 553 * Multicast NS MUST add one add the option 554 * Unicast NS SHOULD add one add the option 555 */ 556 if (!dad && (mac = nd6_ifptomac(ifp))) { 557 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 558 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 559 /* 8 byte alignments... */ 560 optlen = (optlen + 7) & ~7; 561 562 m->m_pkthdr.len += optlen; 563 m->m_len += optlen; 564 icmp6len += optlen; 565 bzero((caddr_t)nd_opt, optlen); 566 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 567 nd_opt->nd_opt_len = optlen >> 3; 568 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 569 } 570 571 ip6->ip6_plen = htons((u_short)icmp6len); 572 nd_ns->nd_ns_cksum = 0; 573 nd_ns->nd_ns_cksum = 574 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 575 576 if (send_sendso_input_hook != NULL) { 577 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 578 sizeof(unsigned short), M_NOWAIT); 579 if (mtag == NULL) 580 goto bad; 581 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 582 m_tag_prepend(m, mtag); 583 } 584 585 ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL, NULL); 586 icmp6_ifstat_inc(ifp, ifs6_out_msg); 587 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 588 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 589 590 if (ro.ro_rt) { /* we don't cache this route. */ 591 RTFREE(ro.ro_rt); 592 } 593 return; 594 595 bad: 596 if (ro.ro_rt) { 597 RTFREE(ro.ro_rt); 598 } 599 m_freem(m); 600 return; 601} 602 603/* 604 * Neighbor advertisement input handling. 605 * 606 * Based on RFC 2461 607 * Based on RFC 2462 (duplicate address detection) 608 * 609 * the following items are not implemented yet: 610 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 611 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 612 */ 613void 614nd6_na_input(struct mbuf *m, int off, int icmp6len) 615{ 616 struct ifnet *ifp = m->m_pkthdr.rcvif; 617 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 618 struct nd_neighbor_advert *nd_na; 619 struct in6_addr daddr6 = ip6->ip6_dst; 620 struct in6_addr taddr6; 621 int flags; 622 int is_router; 623 int is_solicited; 624 int is_override; 625 char *lladdr = NULL; 626 int lladdrlen = 0; 627 int checklink = 0; 628 struct ifaddr *ifa; 629 struct llentry *ln = NULL; 630 union nd_opts ndopts; 631 struct mbuf *chain = NULL; 632 struct m_tag *mtag; 633 struct sockaddr_in6 sin6; 634 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 635 636 if (ip6->ip6_hlim != 255) { 637 nd6log((LOG_ERR, 638 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 639 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 640 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 641 goto bad; 642 } 643 644#ifndef PULLDOWN_TEST 645 IP6_EXTHDR_CHECK(m, off, icmp6len,); 646 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 647#else 648 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 649 if (nd_na == NULL) { 650 ICMP6STAT_INC(icp6s_tooshort); 651 return; 652 } 653#endif 654 655 flags = nd_na->nd_na_flags_reserved; 656 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 657 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 658 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 659 660 taddr6 = nd_na->nd_na_target; 661 if (in6_setscope(&taddr6, ifp, NULL)) 662 goto bad; /* XXX: impossible */ 663 664 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 665 nd6log((LOG_ERR, 666 "nd6_na_input: invalid target address %s\n", 667 ip6_sprintf(ip6bufs, &taddr6))); 668 goto bad; 669 } 670 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 671 if (is_solicited) { 672 nd6log((LOG_ERR, 673 "nd6_na_input: a solicited adv is multicasted\n")); 674 goto bad; 675 } 676 677 icmp6len -= sizeof(*nd_na); 678 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 679 if (nd6_options(&ndopts) < 0) { 680 nd6log((LOG_INFO, 681 "nd6_na_input: invalid ND option, ignored\n")); 682 /* nd6_options have incremented stats */ 683 goto freeit; 684 } 685 686 if (ndopts.nd_opts_tgt_lladdr) { 687 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 688 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 689 } 690 691 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 692 693 /* 694 * Target address matches one of my interface address. 695 * 696 * If my address is tentative, this means that there's somebody 697 * already using the same address as mine. This indicates DAD failure. 698 * This is defined in RFC 2462. 699 * 700 * Otherwise, process as defined in RFC 2461. 701 */ 702 if (ifa 703 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 704 ifa_free(ifa); 705 nd6_dad_na_input(ifa); 706 goto freeit; 707 } 708 709 /* Just for safety, maybe unnecessary. */ 710 if (ifa) { 711 ifa_free(ifa); 712 log(LOG_ERR, 713 "nd6_na_input: duplicate IP6 address %s\n", 714 ip6_sprintf(ip6bufs, &taddr6)); 715 goto freeit; 716 } 717 718 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 719 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 720 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 721 ifp->if_addrlen, lladdrlen - 2)); 722 goto bad; 723 } 724 725 /* 726 * If no neighbor cache entry is found, NA SHOULD silently be 727 * discarded. 728 */ 729 IF_AFDATA_LOCK(ifp); 730 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 731 IF_AFDATA_UNLOCK(ifp); 732 if (ln == NULL) { 733 goto freeit; 734 } 735 736 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 737 /* 738 * If the link-layer has address, and no lladdr option came, 739 * discard the packet. 740 */ 741 if (ifp->if_addrlen && lladdr == NULL) { 742 goto freeit; 743 } 744 745 /* 746 * Record link-layer address, and update the state. 747 */ 748 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen); 749 ln->la_flags |= LLE_VALID; 750 if (is_solicited) { 751 ln->ln_state = ND6_LLINFO_REACHABLE; 752 ln->ln_byhint = 0; 753 if (!ND6_LLINFO_PERMANENT(ln)) { 754 nd6_llinfo_settimer_locked(ln, 755 (long)ND_IFINFO(ln->lle_tbl->llt_ifp)->reachable * hz); 756 } 757 } else { 758 ln->ln_state = ND6_LLINFO_STALE; 759 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz); 760 } 761 if ((ln->ln_router = is_router) != 0) { 762 /* 763 * This means a router's state has changed from 764 * non-reachable to probably reachable, and might 765 * affect the status of associated prefixes.. 766 */ 767 checklink = 1; 768 } 769 } else { 770 int llchange; 771 772 /* 773 * Check if the link-layer address has changed or not. 774 */ 775 if (lladdr == NULL) 776 llchange = 0; 777 else { 778 if (ln->la_flags & LLE_VALID) { 779 if (bcmp(lladdr, &ln->ll_addr, ifp->if_addrlen)) 780 llchange = 1; 781 else 782 llchange = 0; 783 } else 784 llchange = 1; 785 } 786 787 /* 788 * This is VERY complex. Look at it with care. 789 * 790 * override solicit lladdr llchange action 791 * (L: record lladdr) 792 * 793 * 0 0 n -- (2c) 794 * 0 0 y n (2b) L 795 * 0 0 y y (1) REACHABLE->STALE 796 * 0 1 n -- (2c) *->REACHABLE 797 * 0 1 y n (2b) L *->REACHABLE 798 * 0 1 y y (1) REACHABLE->STALE 799 * 1 0 n -- (2a) 800 * 1 0 y n (2a) L 801 * 1 0 y y (2a) L *->STALE 802 * 1 1 n -- (2a) *->REACHABLE 803 * 1 1 y n (2a) L *->REACHABLE 804 * 1 1 y y (2a) L *->REACHABLE 805 */ 806 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 807 /* 808 * If state is REACHABLE, make it STALE. 809 * no other updates should be done. 810 */ 811 if (ln->ln_state == ND6_LLINFO_REACHABLE) { 812 ln->ln_state = ND6_LLINFO_STALE; 813 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz); 814 } 815 goto freeit; 816 } else if (is_override /* (2a) */ 817 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 818 || lladdr == NULL) { /* (2c) */ 819 /* 820 * Update link-local address, if any. 821 */ 822 if (lladdr != NULL) { 823 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen); 824 ln->la_flags |= LLE_VALID; 825 } 826 827 /* 828 * If solicited, make the state REACHABLE. 829 * If not solicited and the link-layer address was 830 * changed, make it STALE. 831 */ 832 if (is_solicited) { 833 ln->ln_state = ND6_LLINFO_REACHABLE; 834 ln->ln_byhint = 0; 835 if (!ND6_LLINFO_PERMANENT(ln)) { 836 nd6_llinfo_settimer_locked(ln, 837 (long)ND_IFINFO(ifp)->reachable * hz); 838 } 839 } else { 840 if (lladdr != NULL && llchange) { 841 ln->ln_state = ND6_LLINFO_STALE; 842 nd6_llinfo_settimer_locked(ln, 843 (long)V_nd6_gctimer * hz); 844 } 845 } 846 } 847 848 if (ln->ln_router && !is_router) { 849 /* 850 * The peer dropped the router flag. 851 * Remove the sender from the Default Router List and 852 * update the Destination Cache entries. 853 */ 854 struct nd_defrouter *dr; 855 struct in6_addr *in6; 856 857 in6 = &L3_ADDR_SIN6(ln)->sin6_addr; 858 859 /* 860 * Lock to protect the default router list. 861 * XXX: this might be unnecessary, since this function 862 * is only called under the network software interrupt 863 * context. However, we keep it just for safety. 864 */ 865 dr = defrouter_lookup(in6, ln->lle_tbl->llt_ifp); 866 if (dr) 867 defrtrlist_del(dr); 868 else if (ND_IFINFO(ln->lle_tbl->llt_ifp)->flags & 869 ND6_IFF_ACCEPT_RTADV) { 870 /* 871 * Even if the neighbor is not in the default 872 * router list, the neighbor may be used 873 * as a next hop for some destinations 874 * (e.g. redirect case). So we must 875 * call rt6_flush explicitly. 876 */ 877 rt6_flush(&ip6->ip6_src, ifp); 878 } 879 } 880 ln->ln_router = is_router; 881 } 882 /* XXX - QL 883 * Does this matter? 884 * rt->rt_flags &= ~RTF_REJECT; 885 */ 886 ln->la_asked = 0; 887 if (ln->la_hold) { 888 struct mbuf *m_hold, *m_hold_next; 889 890 /* 891 * reset the la_hold in advance, to explicitly 892 * prevent a la_hold lookup in nd6_output() 893 * (wouldn't happen, though...) 894 */ 895 for (m_hold = ln->la_hold, ln->la_hold = NULL; 896 m_hold; m_hold = m_hold_next) { 897 m_hold_next = m_hold->m_nextpkt; 898 m_hold->m_nextpkt = NULL; 899 /* 900 * we assume ifp is not a loopback here, so just set 901 * the 2nd argument as the 1st one. 902 */ 903 904 if (send_sendso_input_hook != NULL) { 905 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 906 sizeof(unsigned short), M_NOWAIT); 907 if (mtag == NULL) 908 goto bad; 909 m_tag_prepend(m, mtag); 910 } 911 912 nd6_output_lle(ifp, ifp, m_hold, L3_ADDR_SIN6(ln), NULL, ln, &chain); 913 } 914 } 915 freeit: 916 if (ln != NULL) { 917 if (chain) 918 memcpy(&sin6, L3_ADDR_SIN6(ln), sizeof(sin6)); 919 LLE_WUNLOCK(ln); 920 921 if (chain) 922 nd6_output_flush(ifp, ifp, chain, &sin6, NULL); 923 } 924 if (checklink) 925 pfxlist_onlink_check(); 926 927 m_freem(m); 928 return; 929 930 bad: 931 if (ln != NULL) 932 LLE_WUNLOCK(ln); 933 934 ICMP6STAT_INC(icp6s_badna); 935 m_freem(m); 936} 937 938/* 939 * Neighbor advertisement output handling. 940 * 941 * Based on RFC 2461 942 * 943 * the following items are not implemented yet: 944 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 945 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 946 * 947 * tlladdr - 1 if include target link-layer address 948 * sdl0 - sockaddr_dl (= proxy NA) or NULL 949 */ 950void 951nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 952 const struct in6_addr *taddr6, u_long flags, int tlladdr, 953 struct sockaddr *sdl0) 954{ 955 struct mbuf *m; 956 struct m_tag *mtag; 957 struct ip6_hdr *ip6; 958 struct nd_neighbor_advert *nd_na; 959 struct ip6_moptions im6o; 960 struct in6_addr src, daddr6; 961 struct sockaddr_in6 dst_sa; 962 int icmp6len, maxlen, error; 963 caddr_t mac = NULL; 964 struct route_in6 ro; 965 966 bzero(&ro, sizeof(ro)); 967 968 daddr6 = *daddr6_0; /* make a local copy for modification */ 969 970 /* estimate the size of message */ 971 maxlen = sizeof(*ip6) + sizeof(*nd_na); 972 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 973 if (max_linkhdr + maxlen >= MCLBYTES) { 974#ifdef DIAGNOSTIC 975 printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES " 976 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES); 977#endif 978 return; 979 } 980 981 MGETHDR(m, M_DONTWAIT, MT_DATA); 982 if (m && max_linkhdr + maxlen >= MHLEN) { 983 MCLGET(m, M_DONTWAIT); 984 if ((m->m_flags & M_EXT) == 0) { 985 m_free(m); 986 m = NULL; 987 } 988 } 989 if (m == NULL) 990 return; 991 m->m_pkthdr.rcvif = NULL; 992 993 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 994 m->m_flags |= M_MCAST; 995 im6o.im6o_multicast_ifp = ifp; 996 im6o.im6o_multicast_hlim = 255; 997 im6o.im6o_multicast_loop = 0; 998 } 999 1000 icmp6len = sizeof(*nd_na); 1001 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 1002 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 1003 1004 /* fill neighbor advertisement packet */ 1005 ip6 = mtod(m, struct ip6_hdr *); 1006 ip6->ip6_flow = 0; 1007 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 1008 ip6->ip6_vfc |= IPV6_VERSION; 1009 ip6->ip6_nxt = IPPROTO_ICMPV6; 1010 ip6->ip6_hlim = 255; 1011 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 1012 /* reply to DAD */ 1013 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 1014 daddr6.s6_addr16[1] = 0; 1015 daddr6.s6_addr32[1] = 0; 1016 daddr6.s6_addr32[2] = 0; 1017 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 1018 if (in6_setscope(&daddr6, ifp, NULL)) 1019 goto bad; 1020 1021 flags &= ~ND_NA_FLAG_SOLICITED; 1022 } 1023 ip6->ip6_dst = daddr6; 1024 bzero(&dst_sa, sizeof(struct sockaddr_in6)); 1025 dst_sa.sin6_family = AF_INET6; 1026 dst_sa.sin6_len = sizeof(struct sockaddr_in6); 1027 dst_sa.sin6_addr = daddr6; 1028 1029 /* 1030 * Select a source whose scope is the same as that of the dest. 1031 */ 1032 bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa)); 1033 error = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, NULL, &src); 1034 if (error) { 1035 char ip6buf[INET6_ADDRSTRLEN]; 1036 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1037 "determined: dst=%s, error=%d\n", 1038 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), error)); 1039 goto bad; 1040 } 1041 ip6->ip6_src = src; 1042 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1043 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1044 nd_na->nd_na_code = 0; 1045 nd_na->nd_na_target = *taddr6; 1046 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1047 1048 /* 1049 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1050 * see nd6_ns_input() for details. 1051 * Basically, if NS packet is sent to unicast/anycast addr, 1052 * target lladdr option SHOULD NOT be included. 1053 */ 1054 if (tlladdr) { 1055 /* 1056 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1057 * lladdr in sdl0. If we are not proxying (sending NA for 1058 * my address) use lladdr configured for the interface. 1059 */ 1060 if (sdl0 == NULL) { 1061 if (ifp->if_carp) 1062 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1063 if (mac == NULL) 1064 mac = nd6_ifptomac(ifp); 1065 } else if (sdl0->sa_family == AF_LINK) { 1066 struct sockaddr_dl *sdl; 1067 sdl = (struct sockaddr_dl *)sdl0; 1068 if (sdl->sdl_alen == ifp->if_addrlen) 1069 mac = LLADDR(sdl); 1070 } 1071 } 1072 if (tlladdr && mac) { 1073 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1074 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1075 1076 /* roundup to 8 bytes alignment! */ 1077 optlen = (optlen + 7) & ~7; 1078 1079 m->m_pkthdr.len += optlen; 1080 m->m_len += optlen; 1081 icmp6len += optlen; 1082 bzero((caddr_t)nd_opt, optlen); 1083 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1084 nd_opt->nd_opt_len = optlen >> 3; 1085 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1086 } else 1087 flags &= ~ND_NA_FLAG_OVERRIDE; 1088 1089 ip6->ip6_plen = htons((u_short)icmp6len); 1090 nd_na->nd_na_flags_reserved = flags; 1091 nd_na->nd_na_cksum = 0; 1092 nd_na->nd_na_cksum = 1093 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1094 1095 if (send_sendso_input_hook != NULL) { 1096 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1097 sizeof(unsigned short), M_NOWAIT); 1098 if (mtag == NULL) 1099 goto bad; 1100 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1101 m_tag_prepend(m, mtag); 1102 } 1103 1104 ip6_output(m, NULL, &ro, 0, &im6o, NULL, NULL); 1105 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1106 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1107 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1108 1109 if (ro.ro_rt) { /* we don't cache this route. */ 1110 RTFREE(ro.ro_rt); 1111 } 1112 return; 1113 1114 bad: 1115 if (ro.ro_rt) { 1116 RTFREE(ro.ro_rt); 1117 } 1118 m_freem(m); 1119 return; 1120} 1121 1122caddr_t 1123nd6_ifptomac(struct ifnet *ifp) 1124{ 1125 switch (ifp->if_type) { 1126 case IFT_ARCNET: 1127 case IFT_ETHER: 1128 case IFT_FDDI: 1129 case IFT_IEEE1394: 1130#ifdef IFT_L2VLAN 1131 case IFT_L2VLAN: 1132#endif 1133#ifdef IFT_IEEE80211 1134 case IFT_IEEE80211: 1135#endif 1136#ifdef IFT_CARP 1137 case IFT_CARP: 1138#endif 1139 case IFT_INFINIBAND: 1140 case IFT_BRIDGE: 1141 case IFT_ISO88025: 1142 return IF_LLADDR(ifp); 1143 default: 1144 return NULL; 1145 } 1146} 1147 1148struct dadq { 1149 TAILQ_ENTRY(dadq) dad_list; 1150 struct ifaddr *dad_ifa; 1151 int dad_count; /* max NS to send */ 1152 int dad_ns_tcount; /* # of trials to send NS */ 1153 int dad_ns_ocount; /* NS sent so far */ 1154 int dad_ns_icount; 1155 int dad_na_icount; 1156 struct callout dad_timer_ch; 1157 struct vnet *dad_vnet; 1158}; 1159 1160static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq); 1161VNET_DEFINE(int, dad_init) = 0; 1162#define V_dadq VNET(dadq) 1163#define V_dad_init VNET(dad_init) 1164 1165static struct dadq * 1166nd6_dad_find(struct ifaddr *ifa) 1167{ 1168 struct dadq *dp; 1169 1170 TAILQ_FOREACH(dp, &V_dadq, dad_list) 1171 if (dp->dad_ifa == ifa) 1172 return (dp); 1173 1174 return (NULL); 1175} 1176 1177static void 1178nd6_dad_starttimer(struct dadq *dp, int ticks) 1179{ 1180 1181 callout_reset(&dp->dad_timer_ch, ticks, 1182 (void (*)(void *))nd6_dad_timer, (void *)dp); 1183} 1184 1185static void 1186nd6_dad_stoptimer(struct dadq *dp) 1187{ 1188 1189 callout_stop(&dp->dad_timer_ch); 1190} 1191 1192/* 1193 * Start Duplicate Address Detection (DAD) for specified interface address. 1194 */ 1195void 1196nd6_dad_start(struct ifaddr *ifa, int delay) 1197{ 1198 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1199 struct dadq *dp; 1200 char ip6buf[INET6_ADDRSTRLEN]; 1201 1202 if (!V_dad_init) { 1203 TAILQ_INIT(&V_dadq); 1204 V_dad_init++; 1205 } 1206 1207 /* 1208 * If we don't need DAD, don't do it. 1209 * There are several cases: 1210 * - DAD is disabled (ip6_dad_count == 0) 1211 * - the interface address is anycast 1212 */ 1213 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1214 log(LOG_DEBUG, 1215 "nd6_dad_start: called with non-tentative address " 1216 "%s(%s)\n", 1217 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1218 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1219 return; 1220 } 1221 if (ia->ia6_flags & IN6_IFF_ANYCAST) { 1222 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1223 return; 1224 } 1225 if (!V_ip6_dad_count) { 1226 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1227 return; 1228 } 1229 if (ifa->ifa_ifp == NULL) 1230 panic("nd6_dad_start: ifa->ifa_ifp == NULL"); 1231 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) { 1232 return; 1233 } 1234 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) 1235 return; 1236 if (nd6_dad_find(ifa) != NULL) { 1237 /* DAD already in progress */ 1238 return; 1239 } 1240 1241 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT); 1242 if (dp == NULL) { 1243 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1244 "%s(%s)\n", 1245 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1246 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1247 return; 1248 } 1249 bzero(dp, sizeof(*dp)); 1250 callout_init(&dp->dad_timer_ch, 0); 1251#ifdef VIMAGE 1252 dp->dad_vnet = curvnet; 1253#endif 1254 TAILQ_INSERT_TAIL(&V_dadq, (struct dadq *)dp, dad_list); 1255 1256 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1257 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1258 1259 /* 1260 * Send NS packet for DAD, ip6_dad_count times. 1261 * Note that we must delay the first transmission, if this is the 1262 * first packet to be sent from the interface after interface 1263 * (re)initialization. 1264 */ 1265 dp->dad_ifa = ifa; 1266 ifa_ref(ifa); /* just for safety */ 1267 dp->dad_count = V_ip6_dad_count; 1268 dp->dad_ns_icount = dp->dad_na_icount = 0; 1269 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1270 if (delay == 0) { 1271 nd6_dad_ns_output(dp, ifa); 1272 nd6_dad_starttimer(dp, 1273 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1274 } else { 1275 nd6_dad_starttimer(dp, delay); 1276 } 1277} 1278 1279/* 1280 * terminate DAD unconditionally. used for address removals. 1281 */ 1282void 1283nd6_dad_stop(struct ifaddr *ifa) 1284{ 1285 struct dadq *dp; 1286 1287 if (!V_dad_init) 1288 return; 1289 dp = nd6_dad_find(ifa); 1290 if (!dp) { 1291 /* DAD wasn't started yet */ 1292 return; 1293 } 1294 1295 nd6_dad_stoptimer(dp); 1296 1297 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list); 1298 free(dp, M_IP6NDP); 1299 dp = NULL; 1300 ifa_free(ifa); 1301} 1302 1303static void 1304nd6_dad_timer(struct dadq *dp) 1305{ 1306 CURVNET_SET(dp->dad_vnet); 1307 int s; 1308 struct ifaddr *ifa = dp->dad_ifa; 1309 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1310 char ip6buf[INET6_ADDRSTRLEN]; 1311 1312 s = splnet(); /* XXX */ 1313 1314 /* Sanity check */ 1315 if (ia == NULL) { 1316 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n"); 1317 goto done; 1318 } 1319 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1320 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1321 "%s(%s)\n", 1322 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1323 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1324 goto done; 1325 } 1326 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1327 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1328 "%s(%s)\n", 1329 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1330 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1331 goto done; 1332 } 1333 1334 /* timeouted with IFF_{RUNNING,UP} check */ 1335 if (dp->dad_ns_tcount > V_dad_maxtry) { 1336 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n", 1337 if_name(ifa->ifa_ifp))); 1338 1339 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list); 1340 free(dp, M_IP6NDP); 1341 dp = NULL; 1342 ifa_free(ifa); 1343 goto done; 1344 } 1345 1346 /* Need more checks? */ 1347 if (dp->dad_ns_ocount < dp->dad_count) { 1348 /* 1349 * We have more NS to go. Send NS packet for DAD. 1350 */ 1351 nd6_dad_ns_output(dp, ifa); 1352 nd6_dad_starttimer(dp, 1353 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1354 } else { 1355 /* 1356 * We have transmitted sufficient number of DAD packets. 1357 * See what we've got. 1358 */ 1359 int duplicate; 1360 1361 duplicate = 0; 1362 1363 if (dp->dad_na_icount) { 1364 /* 1365 * the check is in nd6_dad_na_input(), 1366 * but just in case 1367 */ 1368 duplicate++; 1369 } 1370 1371 if (dp->dad_ns_icount) { 1372 /* We've seen NS, means DAD has failed. */ 1373 duplicate++; 1374 } 1375 1376 if (duplicate) { 1377 /* (*dp) will be freed in nd6_dad_duplicated() */ 1378 dp = NULL; 1379 nd6_dad_duplicated(ifa); 1380 } else { 1381 /* 1382 * We are done with DAD. No NA came, no NS came. 1383 * No duplicate address found. 1384 */ 1385 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1386 1387 nd6log((LOG_DEBUG, 1388 "%s: DAD complete for %s - no duplicates found\n", 1389 if_name(ifa->ifa_ifp), 1390 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1391 1392 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list); 1393 free(dp, M_IP6NDP); 1394 dp = NULL; 1395 ifa_free(ifa); 1396 } 1397 } 1398 1399done: 1400 splx(s); 1401 CURVNET_RESTORE(); 1402} 1403 1404void 1405nd6_dad_duplicated(struct ifaddr *ifa) 1406{ 1407 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1408 struct ifnet *ifp; 1409 struct dadq *dp; 1410 char ip6buf[INET6_ADDRSTRLEN]; 1411 1412 dp = nd6_dad_find(ifa); 1413 if (dp == NULL) { 1414 log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n"); 1415 return; 1416 } 1417 1418 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1419 "NS in/out=%d/%d, NA in=%d\n", 1420 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1421 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount); 1422 1423 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1424 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1425 1426 /* We are done with DAD, with duplicate address found. (failure) */ 1427 nd6_dad_stoptimer(dp); 1428 1429 ifp = ifa->ifa_ifp; 1430 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1431 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1432 log(LOG_ERR, "%s: manual intervention required\n", 1433 if_name(ifp)); 1434 1435 /* 1436 * If the address is a link-local address formed from an interface 1437 * identifier based on the hardware address which is supposed to be 1438 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1439 * operation on the interface SHOULD be disabled. 1440 * [RFC 4862, Section 5.4.5] 1441 */ 1442 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1443 struct in6_addr in6; 1444 1445 /* 1446 * To avoid over-reaction, we only apply this logic when we are 1447 * very sure that hardware addresses are supposed to be unique. 1448 */ 1449 switch (ifp->if_type) { 1450 case IFT_ETHER: 1451 case IFT_FDDI: 1452 case IFT_ATM: 1453 case IFT_IEEE1394: 1454#ifdef IFT_IEEE80211 1455 case IFT_IEEE80211: 1456#endif 1457 case IFT_INFINIBAND: 1458 in6 = ia->ia_addr.sin6_addr; 1459 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1460 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1461 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1462 log(LOG_ERR, "%s: possible hardware address " 1463 "duplication detected, disable IPv6\n", 1464 if_name(ifp)); 1465 } 1466 break; 1467 } 1468 } 1469 1470 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list); 1471 free(dp, M_IP6NDP); 1472 dp = NULL; 1473 ifa_free(ifa); 1474} 1475 1476static void 1477nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa) 1478{ 1479 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1480 struct ifnet *ifp = ifa->ifa_ifp; 1481 1482 dp->dad_ns_tcount++; 1483 if ((ifp->if_flags & IFF_UP) == 0) { 1484 return; 1485 } 1486 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1487 return; 1488 } 1489 1490 dp->dad_ns_ocount++; 1491 nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1); 1492} 1493 1494static void 1495nd6_dad_ns_input(struct ifaddr *ifa) 1496{ 1497 struct in6_ifaddr *ia; 1498 struct ifnet *ifp; 1499 const struct in6_addr *taddr6; 1500 struct dadq *dp; 1501 int duplicate; 1502 1503 if (ifa == NULL) 1504 panic("ifa == NULL in nd6_dad_ns_input"); 1505 1506 ia = (struct in6_ifaddr *)ifa; 1507 ifp = ifa->ifa_ifp; 1508 taddr6 = &ia->ia_addr.sin6_addr; 1509 duplicate = 0; 1510 dp = nd6_dad_find(ifa); 1511 1512 /* Quickhack - completely ignore DAD NS packets */ 1513 if (V_dad_ignore_ns) { 1514 char ip6buf[INET6_ADDRSTRLEN]; 1515 nd6log((LOG_INFO, 1516 "nd6_dad_ns_input: ignoring DAD NS packet for " 1517 "address %s(%s)\n", ip6_sprintf(ip6buf, taddr6), 1518 if_name(ifa->ifa_ifp))); 1519 return; 1520 } 1521 1522 /* 1523 * if I'm yet to start DAD, someone else started using this address 1524 * first. I have a duplicate and you win. 1525 */ 1526 if (dp == NULL || dp->dad_ns_ocount == 0) 1527 duplicate++; 1528 1529 /* XXX more checks for loopback situation - see nd6_dad_timer too */ 1530 1531 if (duplicate) { 1532 dp = NULL; /* will be freed in nd6_dad_duplicated() */ 1533 nd6_dad_duplicated(ifa); 1534 } else { 1535 /* 1536 * not sure if I got a duplicate. 1537 * increment ns count and see what happens. 1538 */ 1539 if (dp) 1540 dp->dad_ns_icount++; 1541 } 1542} 1543 1544static void 1545nd6_dad_na_input(struct ifaddr *ifa) 1546{ 1547 struct dadq *dp; 1548 1549 if (ifa == NULL) 1550 panic("ifa == NULL in nd6_dad_na_input"); 1551 1552 dp = nd6_dad_find(ifa); 1553 if (dp) 1554 dp->dad_na_icount++; 1555 1556 /* remove the address. */ 1557 nd6_dad_duplicated(ifa); 1558} 1559