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("$FreeBSD$"); 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 #include <sys/refcount.h> 55 56 #include <net/if.h> 57 #include <net/if_types.h> 58 #include <net/if_dl.h> 59 #include <net/if_var.h> 60 #include <net/route.h> 61 #ifdef RADIX_MPATH 62 #include <net/radix_mpath.h> 63 #endif 64 65 #include <netinet/in.h> 66 #include <netinet/in_var.h> 67 #include <net/if_llatbl.h> 68 #define L3_ADDR_SIN6(le) ((struct sockaddr_in6 *) L3_ADDR(le)) 69 #include <netinet6/in6_var.h> 70 #include <netinet6/in6_ifattach.h> 71 #include <netinet/ip6.h> 72 #include <netinet6/ip6_var.h> 73 #include <netinet6/scope6_var.h> 74 #include <netinet6/nd6.h> 75 #include <netinet/icmp6.h> 76 #include <netinet/ip_carp.h> 77 #include <netinet6/send.h> 78 79 #define SDL(s) ((struct sockaddr_dl *)s) 80 81 struct dadq; 82 static struct dadq *nd6_dad_find(struct ifaddr *); 83 static void nd6_dad_add(struct dadq *dp); 84 static void nd6_dad_del(struct dadq *dp); 85 static void nd6_dad_rele(struct dadq *); 86 static void nd6_dad_starttimer(struct dadq *, int); 87 static void nd6_dad_stoptimer(struct dadq *); 88 static void nd6_dad_timer(struct dadq *); 89 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *); 90 static void nd6_dad_ns_output(struct dadq *, struct ifaddr *); 91 static void nd6_dad_ns_input(struct ifaddr *); 92 static void nd6_dad_na_input(struct ifaddr *); 93 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 94 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 95 96 static VNET_DEFINE(int, dad_ignore_ns) = 0; /* ignore NS in DAD 97 - specwise incorrect */ 98 static VNET_DEFINE(int, dad_maxtry) = 15; /* max # of *tries* to 99 transmit DAD packet */ 100 #define V_dad_ignore_ns VNET(dad_ignore_ns) 101 #define V_dad_maxtry VNET(dad_maxtry) 102 103 /* 104 * Input a Neighbor Solicitation Message. 105 * 106 * Based on RFC 2461 107 * Based on RFC 2462 (duplicate address detection) 108 */ 109 void 110 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 111 { 112 struct ifnet *ifp = m->m_pkthdr.rcvif; 113 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 114 struct nd_neighbor_solicit *nd_ns; 115 struct in6_addr saddr6 = ip6->ip6_src; 116 struct in6_addr daddr6 = ip6->ip6_dst; 117 struct in6_addr taddr6; 118 struct in6_addr myaddr6; 119 char *lladdr = NULL; 120 struct ifaddr *ifa = NULL; 121 int lladdrlen = 0; 122 int anycast = 0, proxy = 0, tentative = 0; 123 int tlladdr; 124 int rflag; 125 union nd_opts ndopts; 126 struct sockaddr_dl proxydl; 127 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 128 129 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 130 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 131 rflag = 0; 132 #ifndef PULLDOWN_TEST 133 IP6_EXTHDR_CHECK(m, off, icmp6len,); 134 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 135 #else 136 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); 137 if (nd_ns == NULL) { 138 ICMP6STAT_INC(icp6s_tooshort); 139 return; 140 } 141 #endif 142 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ 143 taddr6 = nd_ns->nd_ns_target; 144 if (in6_setscope(&taddr6, ifp, NULL) != 0) 145 goto bad; 146 147 if (ip6->ip6_hlim != 255) { 148 nd6log((LOG_ERR, 149 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 150 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 151 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 152 goto bad; 153 } 154 155 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 156 /* dst has to be a solicited node multicast address. */ 157 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 158 /* don't check ifindex portion */ 159 daddr6.s6_addr32[1] == 0 && 160 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 161 daddr6.s6_addr8[12] == 0xff) { 162 ; /* good */ 163 } else { 164 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 165 "(wrong ip6 dst)\n")); 166 goto bad; 167 } 168 } else if (!V_nd6_onlink_ns_rfc4861) { 169 struct sockaddr_in6 src_sa6; 170 171 /* 172 * According to recent IETF discussions, it is not a good idea 173 * to accept a NS from an address which would not be deemed 174 * to be a neighbor otherwise. This point is expected to be 175 * clarified in future revisions of the specification. 176 */ 177 bzero(&src_sa6, sizeof(src_sa6)); 178 src_sa6.sin6_family = AF_INET6; 179 src_sa6.sin6_len = sizeof(src_sa6); 180 src_sa6.sin6_addr = saddr6; 181 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 182 nd6log((LOG_INFO, "nd6_ns_input: " 183 "NS packet from non-neighbor\n")); 184 goto bad; 185 } 186 } 187 188 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 189 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 190 goto bad; 191 } 192 193 icmp6len -= sizeof(*nd_ns); 194 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 195 if (nd6_options(&ndopts) < 0) { 196 nd6log((LOG_INFO, 197 "nd6_ns_input: invalid ND option, ignored\n")); 198 /* nd6_options have incremented stats */ 199 goto freeit; 200 } 201 202 if (ndopts.nd_opts_src_lladdr) { 203 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 204 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 205 } 206 207 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 208 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 209 "(link-layer address option)\n")); 210 goto bad; 211 } 212 213 /* 214 * Attaching target link-layer address to the NA? 215 * (RFC 2461 7.2.4) 216 * 217 * NS IP dst is unicast/anycast MUST NOT add 218 * NS IP dst is solicited-node multicast MUST add 219 * 220 * In implementation, we add target link-layer address by default. 221 * We do not add one in MUST NOT cases. 222 */ 223 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 224 tlladdr = 0; 225 else 226 tlladdr = 1; 227 228 /* 229 * Target address (taddr6) must be either: 230 * (1) Valid unicast/anycast address for my receiving interface, 231 * (2) Unicast address for which I'm offering proxy service, or 232 * (3) "tentative" address on which DAD is being performed. 233 */ 234 /* (1) and (3) check. */ 235 if (ifp->if_carp) 236 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 237 else 238 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 239 240 /* (2) check. */ 241 if (ifa == NULL) { 242 struct route_in6 ro; 243 int need_proxy; 244 245 bzero(&ro, sizeof(ro)); 246 ro.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 247 ro.ro_dst.sin6_family = AF_INET6; 248 ro.ro_dst.sin6_addr = taddr6; 249 250 /* Always use the default FIB. */ 251 #ifdef RADIX_MPATH 252 rtalloc_mpath_fib((struct route *)&ro, ntohl(taddr6.s6_addr32[3]), 253 RT_DEFAULT_FIB); 254 #else 255 in6_rtalloc(&ro, RT_DEFAULT_FIB); 256 #endif 257 need_proxy = (ro.ro_rt && 258 (ro.ro_rt->rt_flags & RTF_ANNOUNCE) != 0 && 259 ro.ro_rt->rt_gateway->sa_family == AF_LINK); 260 if (ro.ro_rt != NULL) { 261 if (need_proxy) 262 proxydl = *SDL(ro.ro_rt->rt_gateway); 263 RTFREE(ro.ro_rt); 264 } 265 if (need_proxy) { 266 /* 267 * proxy NDP for single entry 268 */ 269 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 270 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 271 if (ifa) 272 proxy = 1; 273 } 274 } 275 if (ifa == NULL) { 276 /* 277 * We've got an NS packet, and we don't have that adddress 278 * assigned for us. We MUST silently ignore it. 279 * See RFC2461 7.2.3. 280 */ 281 goto freeit; 282 } 283 myaddr6 = *IFA_IN6(ifa); 284 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 285 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 286 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 287 goto freeit; 288 289 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 290 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 291 "(if %d, NS packet %d)\n", 292 ip6_sprintf(ip6bufs, &taddr6), 293 ifp->if_addrlen, lladdrlen - 2)); 294 goto bad; 295 } 296 297 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 298 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 299 ip6_sprintf(ip6bufs, &saddr6))); 300 goto freeit; 301 } 302 303 /* 304 * We have neighbor solicitation packet, with target address equals to 305 * one of my tentative address. 306 * 307 * src addr how to process? 308 * --- --- 309 * multicast of course, invalid (rejected in ip6_input) 310 * unicast somebody is doing address resolution -> ignore 311 * unspec dup address detection 312 * 313 * The processing is defined in RFC 2462. 314 */ 315 if (tentative) { 316 /* 317 * If source address is unspecified address, it is for 318 * duplicate address detection. 319 * 320 * If not, the packet is for addess resolution; 321 * silently ignore it. 322 */ 323 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 324 nd6_dad_ns_input(ifa); 325 326 goto freeit; 327 } 328 329 /* 330 * If the source address is unspecified address, entries must not 331 * be created or updated. 332 * It looks that sender is performing DAD. Output NA toward 333 * all-node multicast address, to tell the sender that I'm using 334 * the address. 335 * S bit ("solicited") must be zero. 336 */ 337 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 338 struct in6_addr in6_all; 339 340 in6_all = in6addr_linklocal_allnodes; 341 if (in6_setscope(&in6_all, ifp, NULL) != 0) 342 goto bad; 343 nd6_na_output_fib(ifp, &in6_all, &taddr6, 344 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 345 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 346 M_GETFIB(m)); 347 goto freeit; 348 } 349 350 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 351 ND_NEIGHBOR_SOLICIT, 0); 352 353 nd6_na_output_fib(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, M_GETFIB(m)); 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 */ 388 void 389 nd6_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 if (max_linkhdr + maxlen > MHLEN) 417 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 418 else 419 m = m_gethdr(M_NOWAIT, MT_DATA); 420 if (m == NULL) 421 return; 422 423 bzero(&ro, sizeof(ro)); 424 425 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 426 m->m_flags |= M_MCAST; 427 im6o.im6o_multicast_ifp = ifp; 428 im6o.im6o_multicast_hlim = 255; 429 im6o.im6o_multicast_loop = 0; 430 } 431 432 icmp6len = sizeof(*nd_ns); 433 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 434 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 435 436 /* fill neighbor solicitation packet */ 437 ip6 = mtod(m, struct ip6_hdr *); 438 ip6->ip6_flow = 0; 439 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 440 ip6->ip6_vfc |= IPV6_VERSION; 441 /* ip6->ip6_plen will be set later */ 442 ip6->ip6_nxt = IPPROTO_ICMPV6; 443 ip6->ip6_hlim = 255; 444 if (daddr6) 445 ip6->ip6_dst = *daddr6; 446 else { 447 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 448 ip6->ip6_dst.s6_addr16[1] = 0; 449 ip6->ip6_dst.s6_addr32[1] = 0; 450 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 451 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 452 ip6->ip6_dst.s6_addr8[12] = 0xff; 453 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 454 goto bad; 455 } 456 if (!dad) { 457 struct ifaddr *ifa; 458 459 /* 460 * RFC2461 7.2.2: 461 * "If the source address of the packet prompting the 462 * solicitation is the same as one of the addresses assigned 463 * to the outgoing interface, that address SHOULD be placed 464 * in the IP Source Address of the outgoing solicitation. 465 * Otherwise, any one of the addresses assigned to the 466 * interface should be used." 467 * 468 * We use the source address for the prompting packet 469 * (saddr6), if: 470 * - saddr6 is given from the caller (by giving "ln"), and 471 * - saddr6 belongs to the outgoing interface. 472 * Otherwise, we perform the source address selection as usual. 473 */ 474 struct in6_addr *hsrc; 475 476 hsrc = NULL; 477 if (ln != NULL) { 478 LLE_RLOCK(ln); 479 if (ln->la_hold != NULL) { 480 struct ip6_hdr *hip6; /* hold ip6 */ 481 482 /* 483 * assuming every packet in la_hold has the same IP 484 * header 485 */ 486 hip6 = mtod(ln->la_hold, struct ip6_hdr *); 487 /* XXX pullup? */ 488 if (sizeof(*hip6) < ln->la_hold->m_len) { 489 ip6->ip6_src = hip6->ip6_src; 490 hsrc = &hip6->ip6_src; 491 } 492 } 493 LLE_RUNLOCK(ln); 494 } 495 if (hsrc && (ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, 496 hsrc)) != NULL) { 497 /* ip6_src set already. */ 498 ifa_free(ifa); 499 } else { 500 int error; 501 struct sockaddr_in6 dst_sa; 502 struct in6_addr src_in; 503 struct ifnet *oifp; 504 505 bzero(&dst_sa, sizeof(dst_sa)); 506 dst_sa.sin6_family = AF_INET6; 507 dst_sa.sin6_len = sizeof(dst_sa); 508 dst_sa.sin6_addr = ip6->ip6_dst; 509 510 oifp = ifp; 511 error = in6_selectsrc(&dst_sa, NULL, 512 NULL, &ro, NULL, &oifp, &src_in); 513 if (error) { 514 char ip6buf[INET6_ADDRSTRLEN]; 515 nd6log((LOG_DEBUG, 516 "nd6_ns_output: source can't be " 517 "determined: dst=%s, error=%d\n", 518 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), 519 error)); 520 goto bad; 521 } 522 ip6->ip6_src = src_in; 523 } 524 } else { 525 /* 526 * Source address for DAD packet must always be IPv6 527 * unspecified address. (0::0) 528 * We actually don't have to 0-clear the address (we did it 529 * above), but we do so here explicitly to make the intention 530 * clearer. 531 */ 532 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 533 } 534 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 535 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 536 nd_ns->nd_ns_code = 0; 537 nd_ns->nd_ns_reserved = 0; 538 nd_ns->nd_ns_target = *taddr6; 539 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 540 541 /* 542 * Add source link-layer address option. 543 * 544 * spec implementation 545 * --- --- 546 * DAD packet MUST NOT do not add the option 547 * there's no link layer address: 548 * impossible do not add the option 549 * there's link layer address: 550 * Multicast NS MUST add one add the option 551 * Unicast NS SHOULD add one add the option 552 */ 553 if (!dad && (mac = nd6_ifptomac(ifp))) { 554 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 555 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 556 /* 8 byte alignments... */ 557 optlen = (optlen + 7) & ~7; 558 559 m->m_pkthdr.len += optlen; 560 m->m_len += optlen; 561 icmp6len += optlen; 562 bzero((caddr_t)nd_opt, optlen); 563 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 564 nd_opt->nd_opt_len = optlen >> 3; 565 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 566 } 567 568 ip6->ip6_plen = htons((u_short)icmp6len); 569 nd_ns->nd_ns_cksum = 0; 570 nd_ns->nd_ns_cksum = 571 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 572 573 if (send_sendso_input_hook != NULL) { 574 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 575 sizeof(unsigned short), M_NOWAIT); 576 if (mtag == NULL) 577 goto bad; 578 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 579 m_tag_prepend(m, mtag); 580 } 581 582 ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL, NULL); 583 icmp6_ifstat_inc(ifp, ifs6_out_msg); 584 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 585 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 586 587 /* We don't cache this route. */ 588 RO_RTFREE(&ro); 589 590 return; 591 592 bad: 593 if (ro.ro_rt) { 594 RTFREE(ro.ro_rt); 595 } 596 m_freem(m); 597 return; 598 } 599 600 /* 601 * Neighbor advertisement input handling. 602 * 603 * Based on RFC 2461 604 * Based on RFC 2462 (duplicate address detection) 605 * 606 * the following items are not implemented yet: 607 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 608 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 609 */ 610 void 611 nd6_na_input(struct mbuf *m, int off, int icmp6len) 612 { 613 struct ifnet *ifp = m->m_pkthdr.rcvif; 614 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 615 struct nd_neighbor_advert *nd_na; 616 struct in6_addr daddr6 = ip6->ip6_dst; 617 struct in6_addr taddr6; 618 int flags; 619 int is_router; 620 int is_solicited; 621 int is_override; 622 char *lladdr = NULL; 623 int lladdrlen = 0; 624 int checklink = 0; 625 struct ifaddr *ifa; 626 struct llentry *ln = NULL; 627 union nd_opts ndopts; 628 struct mbuf *chain = NULL; 629 struct m_tag *mtag; 630 struct sockaddr_in6 sin6; 631 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 632 633 if (ip6->ip6_hlim != 255) { 634 nd6log((LOG_ERR, 635 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 636 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 637 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 638 goto bad; 639 } 640 641 #ifndef PULLDOWN_TEST 642 IP6_EXTHDR_CHECK(m, off, icmp6len,); 643 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 644 #else 645 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 646 if (nd_na == NULL) { 647 ICMP6STAT_INC(icp6s_tooshort); 648 return; 649 } 650 #endif 651 652 flags = nd_na->nd_na_flags_reserved; 653 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 654 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 655 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 656 657 taddr6 = nd_na->nd_na_target; 658 if (in6_setscope(&taddr6, ifp, NULL)) 659 goto bad; /* XXX: impossible */ 660 661 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 662 nd6log((LOG_ERR, 663 "nd6_na_input: invalid target address %s\n", 664 ip6_sprintf(ip6bufs, &taddr6))); 665 goto bad; 666 } 667 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 668 if (is_solicited) { 669 nd6log((LOG_ERR, 670 "nd6_na_input: a solicited adv is multicasted\n")); 671 goto bad; 672 } 673 674 icmp6len -= sizeof(*nd_na); 675 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 676 if (nd6_options(&ndopts) < 0) { 677 nd6log((LOG_INFO, 678 "nd6_na_input: invalid ND option, ignored\n")); 679 /* nd6_options have incremented stats */ 680 goto freeit; 681 } 682 683 if (ndopts.nd_opts_tgt_lladdr) { 684 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 685 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 686 } 687 688 /* 689 * This effectively disables the DAD check on a non-master CARP 690 * address. 691 */ 692 if (ifp->if_carp) 693 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 694 else 695 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 696 697 /* 698 * Target address matches one of my interface address. 699 * 700 * If my address is tentative, this means that there's somebody 701 * already using the same address as mine. This indicates DAD failure. 702 * This is defined in RFC 2462. 703 * 704 * Otherwise, process as defined in RFC 2461. 705 */ 706 if (ifa 707 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 708 ifa_free(ifa); 709 nd6_dad_na_input(ifa); 710 goto freeit; 711 } 712 713 /* Just for safety, maybe unnecessary. */ 714 if (ifa) { 715 ifa_free(ifa); 716 log(LOG_ERR, 717 "nd6_na_input: duplicate IP6 address %s\n", 718 ip6_sprintf(ip6bufs, &taddr6)); 719 goto freeit; 720 } 721 722 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 723 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 724 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 725 ifp->if_addrlen, lladdrlen - 2)); 726 goto bad; 727 } 728 729 /* 730 * If no neighbor cache entry is found, NA SHOULD silently be 731 * discarded. 732 */ 733 IF_AFDATA_RLOCK(ifp); 734 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 735 IF_AFDATA_RUNLOCK(ifp); 736 if (ln == NULL) { 737 goto freeit; 738 } 739 740 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 741 /* 742 * If the link-layer has address, and no lladdr option came, 743 * discard the packet. 744 */ 745 if (ifp->if_addrlen && lladdr == NULL) { 746 goto freeit; 747 } 748 749 /* 750 * Record link-layer address, and update the state. 751 */ 752 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen); 753 ln->la_flags |= LLE_VALID; 754 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 755 if (is_solicited) { 756 ln->ln_state = ND6_LLINFO_REACHABLE; 757 ln->ln_byhint = 0; 758 if (!ND6_LLINFO_PERMANENT(ln)) { 759 nd6_llinfo_settimer_locked(ln, 760 (long)ND_IFINFO(ln->lle_tbl->llt_ifp)->reachable * hz); 761 } 762 } else { 763 ln->ln_state = ND6_LLINFO_STALE; 764 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz); 765 } 766 if ((ln->ln_router = is_router) != 0) { 767 /* 768 * This means a router's state has changed from 769 * non-reachable to probably reachable, and might 770 * affect the status of associated prefixes.. 771 */ 772 checklink = 1; 773 } 774 } else { 775 int llchange; 776 777 /* 778 * Check if the link-layer address has changed or not. 779 */ 780 if (lladdr == NULL) 781 llchange = 0; 782 else { 783 if (ln->la_flags & LLE_VALID) { 784 if (bcmp(lladdr, &ln->ll_addr, ifp->if_addrlen)) 785 llchange = 1; 786 else 787 llchange = 0; 788 } else 789 llchange = 1; 790 } 791 792 /* 793 * This is VERY complex. Look at it with care. 794 * 795 * override solicit lladdr llchange action 796 * (L: record lladdr) 797 * 798 * 0 0 n -- (2c) 799 * 0 0 y n (2b) L 800 * 0 0 y y (1) REACHABLE->STALE 801 * 0 1 n -- (2c) *->REACHABLE 802 * 0 1 y n (2b) L *->REACHABLE 803 * 0 1 y y (1) REACHABLE->STALE 804 * 1 0 n -- (2a) 805 * 1 0 y n (2a) L 806 * 1 0 y y (2a) L *->STALE 807 * 1 1 n -- (2a) *->REACHABLE 808 * 1 1 y n (2a) L *->REACHABLE 809 * 1 1 y y (2a) L *->REACHABLE 810 */ 811 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 812 /* 813 * If state is REACHABLE, make it STALE. 814 * no other updates should be done. 815 */ 816 if (ln->ln_state == ND6_LLINFO_REACHABLE) { 817 ln->ln_state = ND6_LLINFO_STALE; 818 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz); 819 } 820 goto freeit; 821 } else if (is_override /* (2a) */ 822 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 823 || lladdr == NULL) { /* (2c) */ 824 /* 825 * Update link-local address, if any. 826 */ 827 if (lladdr != NULL) { 828 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen); 829 ln->la_flags |= LLE_VALID; 830 EVENTHANDLER_INVOKE(lle_event, ln, 831 LLENTRY_RESOLVED); 832 } 833 834 /* 835 * If solicited, make the state REACHABLE. 836 * If not solicited and the link-layer address was 837 * changed, make it STALE. 838 */ 839 if (is_solicited) { 840 ln->ln_state = ND6_LLINFO_REACHABLE; 841 ln->ln_byhint = 0; 842 if (!ND6_LLINFO_PERMANENT(ln)) { 843 nd6_llinfo_settimer_locked(ln, 844 (long)ND_IFINFO(ifp)->reachable * hz); 845 } 846 } else { 847 if (lladdr != NULL && llchange) { 848 ln->ln_state = ND6_LLINFO_STALE; 849 nd6_llinfo_settimer_locked(ln, 850 (long)V_nd6_gctimer * hz); 851 } 852 } 853 } 854 855 if (ln->ln_router && !is_router) { 856 /* 857 * The peer dropped the router flag. 858 * Remove the sender from the Default Router List and 859 * update the Destination Cache entries. 860 */ 861 struct nd_defrouter *dr; 862 struct in6_addr *in6; 863 864 in6 = &L3_ADDR_SIN6(ln)->sin6_addr; 865 866 /* 867 * Lock to protect the default router list. 868 * XXX: this might be unnecessary, since this function 869 * is only called under the network software interrupt 870 * context. However, we keep it just for safety. 871 */ 872 dr = defrouter_lookup(in6, ln->lle_tbl->llt_ifp); 873 if (dr) 874 defrtrlist_del(dr); 875 else if (ND_IFINFO(ln->lle_tbl->llt_ifp)->flags & 876 ND6_IFF_ACCEPT_RTADV) { 877 /* 878 * Even if the neighbor is not in the default 879 * router list, the neighbor may be used 880 * as a next hop for some destinations 881 * (e.g. redirect case). So we must 882 * call rt6_flush explicitly. 883 */ 884 rt6_flush(&ip6->ip6_src, ifp); 885 } 886 } 887 ln->ln_router = is_router; 888 } 889 /* XXX - QL 890 * Does this matter? 891 * rt->rt_flags &= ~RTF_REJECT; 892 */ 893 ln->la_asked = 0; 894 if (ln->la_hold) { 895 struct mbuf *m_hold, *m_hold_next; 896 897 /* 898 * reset the la_hold in advance, to explicitly 899 * prevent a la_hold lookup in nd6_output() 900 * (wouldn't happen, though...) 901 */ 902 for (m_hold = ln->la_hold, ln->la_hold = NULL; 903 m_hold; m_hold = m_hold_next) { 904 m_hold_next = m_hold->m_nextpkt; 905 m_hold->m_nextpkt = NULL; 906 /* 907 * we assume ifp is not a loopback here, so just set 908 * the 2nd argument as the 1st one. 909 */ 910 911 if (send_sendso_input_hook != NULL) { 912 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 913 sizeof(unsigned short), M_NOWAIT); 914 if (mtag == NULL) 915 goto bad; 916 m_tag_prepend(m, mtag); 917 } 918 919 nd6_output_lle(ifp, ifp, m_hold, L3_ADDR_SIN6(ln), NULL, ln, &chain); 920 } 921 } 922 freeit: 923 if (ln != NULL) { 924 if (chain) 925 memcpy(&sin6, L3_ADDR_SIN6(ln), sizeof(sin6)); 926 LLE_WUNLOCK(ln); 927 928 if (chain) 929 nd6_output_flush(ifp, ifp, chain, &sin6); 930 } 931 if (checklink) 932 pfxlist_onlink_check(); 933 934 m_freem(m); 935 return; 936 937 bad: 938 if (ln != NULL) 939 LLE_WUNLOCK(ln); 940 941 ICMP6STAT_INC(icp6s_badna); 942 m_freem(m); 943 } 944 945 /* 946 * Neighbor advertisement output handling. 947 * 948 * Based on RFC 2461 949 * 950 * the following items are not implemented yet: 951 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 952 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 953 * 954 * tlladdr - 1 if include target link-layer address 955 * sdl0 - sockaddr_dl (= proxy NA) or NULL 956 */ 957 static void 958 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 959 const struct in6_addr *taddr6, u_long flags, int tlladdr, 960 struct sockaddr *sdl0, u_int fibnum) 961 { 962 struct mbuf *m; 963 struct m_tag *mtag; 964 struct ifnet *oifp; 965 struct ip6_hdr *ip6; 966 struct nd_neighbor_advert *nd_na; 967 struct ip6_moptions im6o; 968 struct in6_addr src, daddr6; 969 struct sockaddr_in6 dst_sa; 970 int icmp6len, maxlen, error; 971 caddr_t mac = NULL; 972 struct route_in6 ro; 973 974 bzero(&ro, sizeof(ro)); 975 976 daddr6 = *daddr6_0; /* make a local copy for modification */ 977 978 /* estimate the size of message */ 979 maxlen = sizeof(*ip6) + sizeof(*nd_na); 980 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 981 if (max_linkhdr + maxlen >= MCLBYTES) { 982 #ifdef DIAGNOSTIC 983 printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES " 984 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES); 985 #endif 986 return; 987 } 988 989 if (max_linkhdr + maxlen > MHLEN) 990 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 991 else 992 m = m_gethdr(M_NOWAIT, MT_DATA); 993 if (m == NULL) 994 return; 995 M_SETFIB(m, fibnum); 996 997 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 998 m->m_flags |= M_MCAST; 999 im6o.im6o_multicast_ifp = ifp; 1000 im6o.im6o_multicast_hlim = 255; 1001 im6o.im6o_multicast_loop = 0; 1002 } 1003 1004 icmp6len = sizeof(*nd_na); 1005 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 1006 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 1007 1008 /* fill neighbor advertisement packet */ 1009 ip6 = mtod(m, struct ip6_hdr *); 1010 ip6->ip6_flow = 0; 1011 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 1012 ip6->ip6_vfc |= IPV6_VERSION; 1013 ip6->ip6_nxt = IPPROTO_ICMPV6; 1014 ip6->ip6_hlim = 255; 1015 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 1016 /* reply to DAD */ 1017 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 1018 daddr6.s6_addr16[1] = 0; 1019 daddr6.s6_addr32[1] = 0; 1020 daddr6.s6_addr32[2] = 0; 1021 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 1022 if (in6_setscope(&daddr6, ifp, NULL)) 1023 goto bad; 1024 1025 flags &= ~ND_NA_FLAG_SOLICITED; 1026 } 1027 ip6->ip6_dst = daddr6; 1028 bzero(&dst_sa, sizeof(struct sockaddr_in6)); 1029 dst_sa.sin6_family = AF_INET6; 1030 dst_sa.sin6_len = sizeof(struct sockaddr_in6); 1031 dst_sa.sin6_addr = daddr6; 1032 1033 /* 1034 * Select a source whose scope is the same as that of the dest. 1035 */ 1036 bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa)); 1037 oifp = ifp; 1038 error = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, &oifp, &src); 1039 if (error) { 1040 char ip6buf[INET6_ADDRSTRLEN]; 1041 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1042 "determined: dst=%s, error=%d\n", 1043 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), error)); 1044 goto bad; 1045 } 1046 ip6->ip6_src = src; 1047 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1048 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1049 nd_na->nd_na_code = 0; 1050 nd_na->nd_na_target = *taddr6; 1051 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1052 1053 /* 1054 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1055 * see nd6_ns_input() for details. 1056 * Basically, if NS packet is sent to unicast/anycast addr, 1057 * target lladdr option SHOULD NOT be included. 1058 */ 1059 if (tlladdr) { 1060 /* 1061 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1062 * lladdr in sdl0. If we are not proxying (sending NA for 1063 * my address) use lladdr configured for the interface. 1064 */ 1065 if (sdl0 == NULL) { 1066 if (ifp->if_carp) 1067 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1068 if (mac == NULL) 1069 mac = nd6_ifptomac(ifp); 1070 } else if (sdl0->sa_family == AF_LINK) { 1071 struct sockaddr_dl *sdl; 1072 sdl = (struct sockaddr_dl *)sdl0; 1073 if (sdl->sdl_alen == ifp->if_addrlen) 1074 mac = LLADDR(sdl); 1075 } 1076 } 1077 if (tlladdr && mac) { 1078 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1079 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1080 1081 /* roundup to 8 bytes alignment! */ 1082 optlen = (optlen + 7) & ~7; 1083 1084 m->m_pkthdr.len += optlen; 1085 m->m_len += optlen; 1086 icmp6len += optlen; 1087 bzero((caddr_t)nd_opt, optlen); 1088 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1089 nd_opt->nd_opt_len = optlen >> 3; 1090 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1091 } else 1092 flags &= ~ND_NA_FLAG_OVERRIDE; 1093 1094 ip6->ip6_plen = htons((u_short)icmp6len); 1095 nd_na->nd_na_flags_reserved = flags; 1096 nd_na->nd_na_cksum = 0; 1097 nd_na->nd_na_cksum = 1098 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1099 1100 if (send_sendso_input_hook != NULL) { 1101 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1102 sizeof(unsigned short), M_NOWAIT); 1103 if (mtag == NULL) 1104 goto bad; 1105 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1106 m_tag_prepend(m, mtag); 1107 } 1108 1109 ip6_output(m, NULL, &ro, 0, &im6o, NULL, NULL); 1110 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1111 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1112 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1113 1114 /* We don't cache this route. */ 1115 RO_RTFREE(&ro); 1116 1117 return; 1118 1119 bad: 1120 if (ro.ro_rt) { 1121 RTFREE(ro.ro_rt); 1122 } 1123 m_freem(m); 1124 return; 1125 } 1126 1127 #ifndef BURN_BRIDGES 1128 void 1129 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1130 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1131 struct sockaddr *sdl0) 1132 { 1133 1134 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1135 RT_DEFAULT_FIB); 1136 } 1137 #endif 1138 1139 caddr_t 1140 nd6_ifptomac(struct ifnet *ifp) 1141 { 1142 switch (ifp->if_type) { 1143 case IFT_ARCNET: 1144 case IFT_ETHER: 1145 case IFT_FDDI: 1146 case IFT_IEEE1394: 1147 #ifdef IFT_L2VLAN 1148 case IFT_L2VLAN: 1149 #endif 1150 #ifdef IFT_IEEE80211 1151 case IFT_IEEE80211: 1152 #endif 1153 case IFT_INFINIBAND: 1154 case IFT_BRIDGE: 1155 case IFT_ISO88025: 1156 return IF_LLADDR(ifp); 1157 default: 1158 return NULL; 1159 } 1160 } 1161 1162 struct dadq { 1163 TAILQ_ENTRY(dadq) dad_list; 1164 struct ifaddr *dad_ifa; 1165 int dad_count; /* max NS to send */ 1166 int dad_ns_tcount; /* # of trials to send NS */ 1167 int dad_ns_ocount; /* NS sent so far */ 1168 int dad_ns_icount; 1169 int dad_na_icount; 1170 struct callout dad_timer_ch; 1171 struct vnet *dad_vnet; 1172 u_int dad_refcnt; 1173 }; 1174 1175 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq); 1176 static VNET_DEFINE(struct rwlock, dad_rwlock); 1177 #define V_dadq VNET(dadq) 1178 #define V_dad_rwlock VNET(dad_rwlock) 1179 1180 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1181 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1182 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1183 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1184 1185 static void 1186 nd6_dad_add(struct dadq *dp) 1187 { 1188 1189 DADQ_WLOCK(); 1190 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1191 DADQ_WUNLOCK(); 1192 } 1193 1194 static void 1195 nd6_dad_del(struct dadq *dp) 1196 { 1197 1198 DADQ_WLOCK(); 1199 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1200 DADQ_WUNLOCK(); 1201 nd6_dad_rele(dp); 1202 } 1203 1204 static struct dadq * 1205 nd6_dad_find(struct ifaddr *ifa) 1206 { 1207 struct dadq *dp; 1208 1209 DADQ_RLOCK(); 1210 TAILQ_FOREACH(dp, &V_dadq, dad_list) 1211 if (dp->dad_ifa == ifa) { 1212 refcount_acquire(&dp->dad_refcnt); 1213 break; 1214 } 1215 DADQ_RUNLOCK(); 1216 1217 return (dp); 1218 } 1219 1220 static void 1221 nd6_dad_starttimer(struct dadq *dp, int ticks) 1222 { 1223 1224 callout_reset(&dp->dad_timer_ch, ticks, 1225 (void (*)(void *))nd6_dad_timer, (void *)dp); 1226 } 1227 1228 static void 1229 nd6_dad_stoptimer(struct dadq *dp) 1230 { 1231 1232 callout_drain(&dp->dad_timer_ch); 1233 } 1234 1235 static void 1236 nd6_dad_rele(struct dadq *dp) 1237 { 1238 1239 if (refcount_release(&dp->dad_refcnt)) { 1240 ifa_free(dp->dad_ifa); 1241 free(dp, M_IP6NDP); 1242 } 1243 } 1244 1245 void 1246 nd6_dad_init(void) 1247 { 1248 1249 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1250 TAILQ_INIT(&V_dadq); 1251 } 1252 1253 /* 1254 * Start Duplicate Address Detection (DAD) for specified interface address. 1255 */ 1256 void 1257 nd6_dad_start(struct ifaddr *ifa, int delay) 1258 { 1259 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1260 struct dadq *dp; 1261 char ip6buf[INET6_ADDRSTRLEN]; 1262 1263 /* 1264 * If we don't need DAD, don't do it. 1265 * There are several cases: 1266 * - DAD is disabled (ip6_dad_count == 0) 1267 * - the interface address is anycast 1268 */ 1269 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1270 log(LOG_DEBUG, 1271 "nd6_dad_start: called with non-tentative address " 1272 "%s(%s)\n", 1273 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1274 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1275 return; 1276 } 1277 if (ia->ia6_flags & IN6_IFF_ANYCAST) { 1278 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1279 return; 1280 } 1281 if (!V_ip6_dad_count) { 1282 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1283 return; 1284 } 1285 if (ifa->ifa_ifp == NULL) 1286 panic("nd6_dad_start: ifa->ifa_ifp == NULL"); 1287 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) { 1288 return; 1289 } 1290 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) 1291 return; 1292 if ((dp = nd6_dad_find(ifa)) != NULL) { 1293 /* DAD already in progress */ 1294 nd6_dad_rele(dp); 1295 return; 1296 } 1297 1298 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1299 if (dp == NULL) { 1300 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1301 "%s(%s)\n", 1302 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1303 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1304 return; 1305 } 1306 callout_init(&dp->dad_timer_ch, 0); 1307 #ifdef VIMAGE 1308 dp->dad_vnet = curvnet; 1309 #endif 1310 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1311 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1312 1313 /* 1314 * Send NS packet for DAD, ip6_dad_count times. 1315 * Note that we must delay the first transmission, if this is the 1316 * first packet to be sent from the interface after interface 1317 * (re)initialization. 1318 */ 1319 dp->dad_ifa = ifa; 1320 ifa_ref(dp->dad_ifa); 1321 dp->dad_count = V_ip6_dad_count; 1322 dp->dad_ns_icount = dp->dad_na_icount = 0; 1323 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1324 refcount_init(&dp->dad_refcnt, 1); 1325 nd6_dad_add(dp); 1326 if (delay == 0) { 1327 nd6_dad_ns_output(dp, ifa); 1328 nd6_dad_starttimer(dp, 1329 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1330 } else { 1331 nd6_dad_starttimer(dp, delay); 1332 } 1333 } 1334 1335 /* 1336 * terminate DAD unconditionally. used for address removals. 1337 */ 1338 void 1339 nd6_dad_stop(struct ifaddr *ifa) 1340 { 1341 struct dadq *dp; 1342 1343 dp = nd6_dad_find(ifa); 1344 if (!dp) { 1345 /* DAD wasn't started yet */ 1346 return; 1347 } 1348 1349 nd6_dad_stoptimer(dp); 1350 1351 /* 1352 * The DAD queue entry may have been removed by nd6_dad_timer() while 1353 * we were waiting for it to stop, so re-do the lookup. 1354 */ 1355 nd6_dad_rele(dp); 1356 if (nd6_dad_find(ifa) == NULL) 1357 return; 1358 1359 nd6_dad_del(dp); 1360 nd6_dad_rele(dp); 1361 } 1362 1363 static void 1364 nd6_dad_timer(struct dadq *dp) 1365 { 1366 CURVNET_SET(dp->dad_vnet); 1367 struct ifaddr *ifa = dp->dad_ifa; 1368 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1369 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1370 char ip6buf[INET6_ADDRSTRLEN]; 1371 1372 /* Sanity check */ 1373 if (ia == NULL) { 1374 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n"); 1375 goto err; 1376 } 1377 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1378 /* Do not need DAD for ifdisabled interface. */ 1379 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1380 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1381 goto err; 1382 } 1383 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1384 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1385 "%s(%s)\n", 1386 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1387 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1388 goto err; 1389 } 1390 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1391 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1392 "%s(%s)\n", 1393 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1394 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1395 goto err; 1396 } 1397 1398 /* timeouted with IFF_{RUNNING,UP} check */ 1399 if (dp->dad_ns_tcount > V_dad_maxtry) { 1400 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n", 1401 if_name(ifa->ifa_ifp))); 1402 goto err; 1403 } 1404 1405 /* Need more checks? */ 1406 if (dp->dad_ns_ocount < dp->dad_count) { 1407 /* 1408 * We have more NS to go. Send NS packet for DAD. 1409 */ 1410 nd6_dad_ns_output(dp, ifa); 1411 nd6_dad_starttimer(dp, 1412 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1413 goto done; 1414 } else { 1415 /* 1416 * We have transmitted sufficient number of DAD packets. 1417 * See what we've got. 1418 */ 1419 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1420 /* We've seen NS or NA, means DAD has failed. */ 1421 nd6_dad_duplicated(ifa, dp); 1422 else { 1423 /* 1424 * We are done with DAD. No NA came, no NS came. 1425 * No duplicate address found. Check IFDISABLED flag 1426 * again in case that it is changed between the 1427 * beginning of this function and here. 1428 */ 1429 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1430 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1431 1432 nd6log((LOG_DEBUG, 1433 "%s: DAD complete for %s - no duplicates found\n", 1434 if_name(ifa->ifa_ifp), 1435 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1436 } 1437 } 1438 err: 1439 nd6_dad_del(dp); 1440 done: 1441 CURVNET_RESTORE(); 1442 } 1443 1444 static void 1445 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1446 { 1447 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1448 struct ifnet *ifp; 1449 char ip6buf[INET6_ADDRSTRLEN]; 1450 1451 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1452 "NS in/out=%d/%d, NA in=%d\n", 1453 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1454 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount); 1455 1456 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1457 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1458 1459 ifp = ifa->ifa_ifp; 1460 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1461 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1462 log(LOG_ERR, "%s: manual intervention required\n", 1463 if_name(ifp)); 1464 1465 /* 1466 * If the address is a link-local address formed from an interface 1467 * identifier based on the hardware address which is supposed to be 1468 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1469 * operation on the interface SHOULD be disabled. 1470 * [RFC 4862, Section 5.4.5] 1471 */ 1472 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1473 struct in6_addr in6; 1474 1475 /* 1476 * To avoid over-reaction, we only apply this logic when we are 1477 * very sure that hardware addresses are supposed to be unique. 1478 */ 1479 switch (ifp->if_type) { 1480 case IFT_ETHER: 1481 case IFT_FDDI: 1482 case IFT_ATM: 1483 case IFT_IEEE1394: 1484 #ifdef IFT_IEEE80211 1485 case IFT_IEEE80211: 1486 #endif 1487 case IFT_INFINIBAND: 1488 in6 = ia->ia_addr.sin6_addr; 1489 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1490 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1491 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1492 log(LOG_ERR, "%s: possible hardware address " 1493 "duplication detected, disable IPv6\n", 1494 if_name(ifp)); 1495 } 1496 break; 1497 } 1498 } 1499 } 1500 1501 static void 1502 nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa) 1503 { 1504 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1505 struct ifnet *ifp = ifa->ifa_ifp; 1506 1507 dp->dad_ns_tcount++; 1508 if ((ifp->if_flags & IFF_UP) == 0) { 1509 return; 1510 } 1511 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1512 return; 1513 } 1514 1515 dp->dad_ns_ocount++; 1516 nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1); 1517 } 1518 1519 static void 1520 nd6_dad_ns_input(struct ifaddr *ifa) 1521 { 1522 struct in6_ifaddr *ia; 1523 struct ifnet *ifp; 1524 const struct in6_addr *taddr6; 1525 struct dadq *dp; 1526 1527 if (ifa == NULL) 1528 panic("ifa == NULL in nd6_dad_ns_input"); 1529 1530 ia = (struct in6_ifaddr *)ifa; 1531 ifp = ifa->ifa_ifp; 1532 taddr6 = &ia->ia_addr.sin6_addr; 1533 dp = nd6_dad_find(ifa); 1534 if (dp == NULL) 1535 return; 1536 1537 /* Quickhack - completely ignore DAD NS packets */ 1538 if (V_dad_ignore_ns) { 1539 char ip6buf[INET6_ADDRSTRLEN]; 1540 nd6log((LOG_INFO, 1541 "nd6_dad_ns_input: ignoring DAD NS packet for " 1542 "address %s(%s)\n", ip6_sprintf(ip6buf, taddr6), 1543 if_name(ifa->ifa_ifp))); 1544 return; 1545 } 1546 1547 /* XXX more checks for loopback situation - see nd6_dad_timer too */ 1548 1549 dp->dad_ns_icount++; 1550 nd6_dad_rele(dp); 1551 } 1552 1553 static void 1554 nd6_dad_na_input(struct ifaddr *ifa) 1555 { 1556 struct dadq *dp; 1557 1558 if (ifa == NULL) 1559 panic("ifa == NULL in nd6_dad_na_input"); 1560 1561 dp = nd6_dad_find(ifa); 1562 if (dp != NULL) { 1563 dp->dad_na_icount++; 1564 nd6_dad_rele(dp); 1565 } 1566 } 1567