1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 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 * $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $ 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 #include "opt_ipsec.h" 40 #include "opt_mpath.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/eventhandler.h> 45 #include <sys/malloc.h> 46 #include <sys/libkern.h> 47 #include <sys/lock.h> 48 #include <sys/rwlock.h> 49 #include <sys/mbuf.h> 50 #include <sys/socket.h> 51 #include <sys/sockio.h> 52 #include <sys/time.h> 53 #include <sys/kernel.h> 54 #include <sys/errno.h> 55 #include <sys/sysctl.h> 56 #include <sys/syslog.h> 57 #include <sys/queue.h> 58 #include <sys/callout.h> 59 #include <sys/refcount.h> 60 61 #include <net/if.h> 62 #include <net/if_types.h> 63 #include <net/if_dl.h> 64 #include <net/if_var.h> 65 #include <net/route.h> 66 #ifdef RADIX_MPATH 67 #include <net/radix_mpath.h> 68 #endif 69 #include <net/vnet.h> 70 71 #include <netinet/in.h> 72 #include <netinet/in_var.h> 73 #include <net/if_llatbl.h> 74 #include <netinet6/in6_var.h> 75 #include <netinet6/in6_ifattach.h> 76 #include <netinet/ip6.h> 77 #include <netinet6/ip6_var.h> 78 #include <netinet6/scope6_var.h> 79 #include <netinet6/nd6.h> 80 #include <netinet/icmp6.h> 81 #include <netinet/ip_carp.h> 82 #include <netinet6/send.h> 83 84 #define SDL(s) ((struct sockaddr_dl *)s) 85 86 struct dadq; 87 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *); 88 static void nd6_dad_add(struct dadq *dp); 89 static void nd6_dad_del(struct dadq *dp); 90 static void nd6_dad_rele(struct dadq *); 91 static void nd6_dad_starttimer(struct dadq *, int, int); 92 static void nd6_dad_stoptimer(struct dadq *); 93 static void nd6_dad_timer(struct dadq *); 94 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *); 95 static void nd6_dad_ns_output(struct dadq *); 96 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *); 97 static void nd6_dad_na_input(struct ifaddr *); 98 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 99 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 100 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *, 101 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int); 102 103 VNET_DEFINE_STATIC(int, dad_enhanced) = 1; 104 #define V_dad_enhanced VNET(dad_enhanced) 105 106 SYSCTL_DECL(_net_inet6_ip6); 107 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW, 108 &VNET_NAME(dad_enhanced), 0, 109 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD."); 110 111 VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to 112 transmit DAD packet */ 113 #define V_dad_maxtry VNET(dad_maxtry) 114 115 /* 116 * Input a Neighbor Solicitation Message. 117 * 118 * Based on RFC 2461 119 * Based on RFC 2462 (duplicate address detection) 120 */ 121 void 122 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 123 { 124 struct ifnet *ifp; 125 struct ip6_hdr *ip6; 126 struct nd_neighbor_solicit *nd_ns; 127 struct in6_addr daddr6, myaddr6, saddr6, taddr6; 128 struct ifaddr *ifa; 129 struct sockaddr_dl proxydl; 130 union nd_opts ndopts; 131 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 132 char *lladdr; 133 int anycast, lladdrlen, proxy, rflag, tentative, tlladdr; 134 135 ifa = NULL; 136 137 /* RFC 6980: Nodes MUST silently ignore fragments */ 138 if(m->m_flags & M_FRAGMENTED) 139 goto freeit; 140 141 ifp = m->m_pkthdr.rcvif; 142 ip6 = mtod(m, struct ip6_hdr *); 143 if (ip6->ip6_hlim != 255) { 144 nd6log((LOG_ERR, 145 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 146 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 147 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 148 goto bads; 149 } 150 151 if (m->m_len < off + icmp6len) { 152 m = m_pullup(m, off + icmp6len); 153 if (m == NULL) { 154 IP6STAT_INC(ip6s_exthdrtoolong); 155 return; 156 } 157 } 158 ip6 = mtod(m, struct ip6_hdr *); 159 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 160 161 saddr6 = ip6->ip6_src; 162 daddr6 = ip6->ip6_dst; 163 taddr6 = nd_ns->nd_ns_target; 164 if (in6_setscope(&taddr6, ifp, NULL) != 0) 165 goto bad; 166 167 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 168 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 169 rflag = 0; 170 171 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 172 /* dst has to be a solicited node multicast address. */ 173 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 174 /* don't check ifindex portion */ 175 daddr6.s6_addr32[1] == 0 && 176 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 177 daddr6.s6_addr8[12] == 0xff) { 178 ; /* good */ 179 } else { 180 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 181 "(wrong ip6 dst)\n")); 182 goto bad; 183 } 184 } else if (!V_nd6_onlink_ns_rfc4861) { 185 struct sockaddr_in6 src_sa6; 186 187 /* 188 * According to recent IETF discussions, it is not a good idea 189 * to accept a NS from an address which would not be deemed 190 * to be a neighbor otherwise. This point is expected to be 191 * clarified in future revisions of the specification. 192 */ 193 bzero(&src_sa6, sizeof(src_sa6)); 194 src_sa6.sin6_family = AF_INET6; 195 src_sa6.sin6_len = sizeof(src_sa6); 196 src_sa6.sin6_addr = saddr6; 197 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 198 nd6log((LOG_INFO, "nd6_ns_input: " 199 "NS packet from non-neighbor\n")); 200 goto bad; 201 } 202 } 203 204 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 205 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 206 goto bad; 207 } 208 209 icmp6len -= sizeof(*nd_ns); 210 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 211 if (nd6_options(&ndopts) < 0) { 212 nd6log((LOG_INFO, 213 "nd6_ns_input: invalid ND option, ignored\n")); 214 /* nd6_options have incremented stats */ 215 goto freeit; 216 } 217 218 lladdr = NULL; 219 lladdrlen = 0; 220 if (ndopts.nd_opts_src_lladdr) { 221 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 222 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 223 } 224 225 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 226 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 227 "(link-layer address option)\n")); 228 goto bad; 229 } 230 231 /* 232 * Attaching target link-layer address to the NA? 233 * (RFC 2461 7.2.4) 234 * 235 * NS IP dst is unicast/anycast MUST NOT add 236 * NS IP dst is solicited-node multicast MUST add 237 * 238 * In implementation, we add target link-layer address by default. 239 * We do not add one in MUST NOT cases. 240 */ 241 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 242 tlladdr = 0; 243 else 244 tlladdr = 1; 245 246 /* 247 * Target address (taddr6) must be either: 248 * (1) Valid unicast/anycast address for my receiving interface, 249 * (2) Unicast address for which I'm offering proxy service, or 250 * (3) "tentative" address on which DAD is being performed. 251 */ 252 /* (1) and (3) check. */ 253 if (ifp->if_carp) 254 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 255 else 256 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 257 258 /* (2) check. */ 259 proxy = 0; 260 if (ifa == NULL) { 261 struct sockaddr_dl rt_gateway; 262 struct rt_addrinfo info; 263 struct sockaddr_in6 dst6; 264 265 bzero(&dst6, sizeof(dst6)); 266 dst6.sin6_len = sizeof(struct sockaddr_in6); 267 dst6.sin6_family = AF_INET6; 268 dst6.sin6_addr = taddr6; 269 270 bzero(&rt_gateway, sizeof(rt_gateway)); 271 rt_gateway.sdl_len = sizeof(rt_gateway); 272 bzero(&info, sizeof(info)); 273 info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway; 274 275 if (rib_lookup_info(ifp->if_fib, (struct sockaddr *)&dst6, 276 0, 0, &info) == 0) { 277 if ((info.rti_flags & RTF_ANNOUNCE) != 0 && 278 rt_gateway.sdl_family == AF_LINK) { 279 280 /* 281 * proxy NDP for single entry 282 */ 283 proxydl = *SDL(&rt_gateway); 284 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal( 285 ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 286 if (ifa) 287 proxy = 1; 288 } 289 } 290 } 291 if (ifa == NULL) { 292 /* 293 * We've got an NS packet, and we don't have that adddress 294 * assigned for us. We MUST silently ignore it. 295 * See RFC2461 7.2.3. 296 */ 297 goto freeit; 298 } 299 myaddr6 = *IFA_IN6(ifa); 300 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 301 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 302 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 303 goto freeit; 304 305 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 306 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 307 "(if %d, NS packet %d)\n", 308 ip6_sprintf(ip6bufs, &taddr6), 309 ifp->if_addrlen, lladdrlen - 2)); 310 goto bad; 311 } 312 313 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 314 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 315 ip6_sprintf(ip6bufs, &saddr6))); 316 goto freeit; 317 } 318 319 /* 320 * We have neighbor solicitation packet, with target address equals to 321 * one of my tentative address. 322 * 323 * src addr how to process? 324 * --- --- 325 * multicast of course, invalid (rejected in ip6_input) 326 * unicast somebody is doing address resolution -> ignore 327 * unspec dup address detection 328 * 329 * The processing is defined in RFC 2462. 330 */ 331 if (tentative) { 332 /* 333 * If source address is unspecified address, it is for 334 * duplicate address detection. 335 * 336 * If not, the packet is for addess resolution; 337 * silently ignore it. 338 */ 339 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 340 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 341 342 goto freeit; 343 } 344 345 /* 346 * If the source address is unspecified address, entries must not 347 * be created or updated. 348 * It looks that sender is performing DAD. Output NA toward 349 * all-node multicast address, to tell the sender that I'm using 350 * the address. 351 * S bit ("solicited") must be zero. 352 */ 353 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 354 struct in6_addr in6_all; 355 356 in6_all = in6addr_linklocal_allnodes; 357 if (in6_setscope(&in6_all, ifp, NULL) != 0) 358 goto bad; 359 nd6_na_output_fib(ifp, &in6_all, &taddr6, 360 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 361 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 362 M_GETFIB(m)); 363 goto freeit; 364 } 365 366 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 367 ND_NEIGHBOR_SOLICIT, 0); 368 369 nd6_na_output_fib(ifp, &saddr6, &taddr6, 370 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 371 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 372 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 373 freeit: 374 if (ifa != NULL) 375 ifa_free(ifa); 376 m_freem(m); 377 return; 378 379 bad: 380 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 381 ip6_sprintf(ip6bufs, &saddr6))); 382 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 383 ip6_sprintf(ip6bufs, &daddr6))); 384 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 385 ip6_sprintf(ip6bufs, &taddr6))); 386 bads: 387 ICMP6STAT_INC(icp6s_badns); 388 if (ifa != NULL) 389 ifa_free(ifa); 390 m_freem(m); 391 } 392 393 /* 394 * Output a Neighbor Solicitation Message. Caller specifies: 395 * - ICMP6 header source IP6 address 396 * - ND6 header target IP6 address 397 * - ND6 header source datalink address 398 * 399 * Based on RFC 2461 400 * Based on RFC 2462 (duplicate address detection) 401 * 402 * ln - for source address determination 403 * nonce - If non-NULL, NS is used for duplicate address detection and 404 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 405 */ 406 static void 407 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 408 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 409 uint8_t *nonce, u_int fibnum) 410 { 411 struct mbuf *m; 412 struct m_tag *mtag; 413 struct ip6_hdr *ip6; 414 struct nd_neighbor_solicit *nd_ns; 415 struct ip6_moptions im6o; 416 int icmp6len; 417 int maxlen; 418 caddr_t mac; 419 420 if (IN6_IS_ADDR_MULTICAST(taddr6)) 421 return; 422 423 /* estimate the size of message */ 424 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 425 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 426 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 427 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 428 __func__, max_linkhdr, maxlen, MCLBYTES)); 429 430 if (max_linkhdr + maxlen > MHLEN) 431 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 432 else 433 m = m_gethdr(M_NOWAIT, MT_DATA); 434 if (m == NULL) 435 return; 436 M_SETFIB(m, fibnum); 437 438 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 439 m->m_flags |= M_MCAST; 440 im6o.im6o_multicast_ifp = ifp; 441 im6o.im6o_multicast_hlim = 255; 442 im6o.im6o_multicast_loop = 0; 443 } 444 445 icmp6len = sizeof(*nd_ns); 446 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 447 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 448 449 /* fill neighbor solicitation packet */ 450 ip6 = mtod(m, struct ip6_hdr *); 451 ip6->ip6_flow = 0; 452 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 453 ip6->ip6_vfc |= IPV6_VERSION; 454 /* ip6->ip6_plen will be set later */ 455 ip6->ip6_nxt = IPPROTO_ICMPV6; 456 ip6->ip6_hlim = 255; 457 if (daddr6) 458 ip6->ip6_dst = *daddr6; 459 else { 460 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 461 ip6->ip6_dst.s6_addr16[1] = 0; 462 ip6->ip6_dst.s6_addr32[1] = 0; 463 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 464 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 465 ip6->ip6_dst.s6_addr8[12] = 0xff; 466 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 467 goto bad; 468 } 469 if (nonce == NULL) { 470 struct ifaddr *ifa = NULL; 471 472 /* 473 * RFC2461 7.2.2: 474 * "If the source address of the packet prompting the 475 * solicitation is the same as one of the addresses assigned 476 * to the outgoing interface, that address SHOULD be placed 477 * in the IP Source Address of the outgoing solicitation. 478 * Otherwise, any one of the addresses assigned to the 479 * interface should be used." 480 * 481 * We use the source address for the prompting packet 482 * (saddr6), if saddr6 belongs to the outgoing interface. 483 * Otherwise, we perform the source address selection as usual. 484 */ 485 486 if (saddr6 != NULL) 487 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 488 if (ifa != NULL) { 489 /* ip6_src set already. */ 490 ip6->ip6_src = *saddr6; 491 ifa_free(ifa); 492 } else { 493 int error; 494 struct in6_addr dst6, src6; 495 uint32_t scopeid; 496 497 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); 498 error = in6_selectsrc_addr(fibnum, &dst6, 499 scopeid, ifp, &src6, NULL); 500 if (error) { 501 char ip6buf[INET6_ADDRSTRLEN]; 502 nd6log((LOG_DEBUG, "%s: source can't be " 503 "determined: dst=%s, error=%d\n", __func__, 504 ip6_sprintf(ip6buf, &dst6), 505 error)); 506 goto bad; 507 } 508 ip6->ip6_src = src6; 509 } 510 } else { 511 /* 512 * Source address for DAD packet must always be IPv6 513 * unspecified address. (0::0) 514 * We actually don't have to 0-clear the address (we did it 515 * above), but we do so here explicitly to make the intention 516 * clearer. 517 */ 518 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 519 } 520 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 521 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 522 nd_ns->nd_ns_code = 0; 523 nd_ns->nd_ns_reserved = 0; 524 nd_ns->nd_ns_target = *taddr6; 525 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 526 527 /* 528 * Add source link-layer address option. 529 * 530 * spec implementation 531 * --- --- 532 * DAD packet MUST NOT do not add the option 533 * there's no link layer address: 534 * impossible do not add the option 535 * there's link layer address: 536 * Multicast NS MUST add one add the option 537 * Unicast NS SHOULD add one add the option 538 */ 539 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 540 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 541 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 542 /* 8 byte alignments... */ 543 optlen = (optlen + 7) & ~7; 544 545 m->m_pkthdr.len += optlen; 546 m->m_len += optlen; 547 icmp6len += optlen; 548 bzero((caddr_t)nd_opt, optlen); 549 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 550 nd_opt->nd_opt_len = optlen >> 3; 551 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 552 } 553 /* 554 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 555 * This behavior is documented as Enhanced Duplicate Address 556 * Detection in RFC 7527. 557 * net.inet6.ip6.dad_enhanced=0 disables this. 558 */ 559 if (V_dad_enhanced != 0 && nonce != NULL) { 560 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 561 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 562 /* 8-byte alignment is required. */ 563 optlen = (optlen + 7) & ~7; 564 565 m->m_pkthdr.len += optlen; 566 m->m_len += optlen; 567 icmp6len += optlen; 568 bzero((caddr_t)nd_opt, optlen); 569 nd_opt->nd_opt_type = ND_OPT_NONCE; 570 nd_opt->nd_opt_len = optlen >> 3; 571 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 572 } 573 ip6->ip6_plen = htons((u_short)icmp6len); 574 nd_ns->nd_ns_cksum = 0; 575 nd_ns->nd_ns_cksum = 576 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 577 578 if (send_sendso_input_hook != NULL) { 579 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 580 sizeof(unsigned short), M_NOWAIT); 581 if (mtag == NULL) 582 goto bad; 583 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 584 m_tag_prepend(m, mtag); 585 } 586 587 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 588 &im6o, NULL, NULL); 589 icmp6_ifstat_inc(ifp, ifs6_out_msg); 590 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 591 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 592 593 return; 594 595 bad: 596 m_freem(m); 597 } 598 599 #ifndef BURN_BRIDGES 600 void 601 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 602 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 603 { 604 605 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 606 } 607 #endif 608 /* 609 * Neighbor advertisement input handling. 610 * 611 * Based on RFC 2461 612 * Based on RFC 2462 (duplicate address detection) 613 * 614 * the following items are not implemented yet: 615 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 616 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 617 */ 618 void 619 nd6_na_input(struct mbuf *m, int off, int icmp6len) 620 { 621 struct ifnet *ifp; 622 struct ip6_hdr *ip6; 623 struct ifaddr *ifa; 624 struct llentry *ln; 625 struct mbuf *chain; 626 struct nd_neighbor_advert *nd_na; 627 struct in6_addr daddr6, taddr6; 628 struct sockaddr_in6 sin6; 629 union nd_opts ndopts; 630 u_char linkhdr[LLE_MAX_LINKHDR]; 631 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 632 char *lladdr; 633 size_t linkhdrsize; 634 int flags, is_override, is_router, is_solicited; 635 int lladdr_off, lladdrlen, checklink; 636 637 NET_EPOCH_ASSERT(); 638 639 chain = NULL; 640 ln = NULL; 641 checklink = 0; 642 643 /* RFC 6980: Nodes MUST silently ignore fragments */ 644 if(m->m_flags & M_FRAGMENTED) 645 goto freeit; 646 647 ifp = m->m_pkthdr.rcvif; 648 ip6 = mtod(m, struct ip6_hdr *); 649 if (ip6->ip6_hlim != 255) { 650 nd6log((LOG_ERR, 651 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 652 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 653 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 654 goto bad; 655 } 656 657 if (m->m_len < off + icmp6len) { 658 m = m_pullup(m, off + icmp6len); 659 if (m == NULL) { 660 IP6STAT_INC(ip6s_exthdrtoolong); 661 return; 662 } 663 } 664 ip6 = mtod(m, struct ip6_hdr *); 665 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 666 667 flags = nd_na->nd_na_flags_reserved; 668 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 669 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 670 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 671 672 taddr6 = nd_na->nd_na_target; 673 if (in6_setscope(&taddr6, ifp, NULL)) 674 goto bad; /* XXX: impossible */ 675 676 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 677 nd6log((LOG_ERR, 678 "nd6_na_input: invalid target address %s\n", 679 ip6_sprintf(ip6bufs, &taddr6))); 680 goto bad; 681 } 682 683 daddr6 = ip6->ip6_dst; 684 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 685 if (is_solicited) { 686 nd6log((LOG_ERR, 687 "nd6_na_input: a solicited adv is multicasted\n")); 688 goto bad; 689 } 690 691 icmp6len -= sizeof(*nd_na); 692 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 693 if (nd6_options(&ndopts) < 0) { 694 nd6log((LOG_INFO, 695 "nd6_na_input: invalid ND option, ignored\n")); 696 /* nd6_options have incremented stats */ 697 goto freeit; 698 } 699 700 lladdr = NULL; 701 lladdrlen = 0; 702 if (ndopts.nd_opts_tgt_lladdr) { 703 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 704 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 705 } 706 707 /* 708 * This effectively disables the DAD check on a non-master CARP 709 * address. 710 */ 711 if (ifp->if_carp) 712 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 713 else 714 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 715 716 /* 717 * Target address matches one of my interface address. 718 * 719 * If my address is tentative, this means that there's somebody 720 * already using the same address as mine. This indicates DAD failure. 721 * This is defined in RFC 2462. 722 * 723 * Otherwise, process as defined in RFC 2461. 724 */ 725 if (ifa 726 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 727 nd6_dad_na_input(ifa); 728 ifa_free(ifa); 729 goto freeit; 730 } 731 732 /* Just for safety, maybe unnecessary. */ 733 if (ifa) { 734 ifa_free(ifa); 735 log(LOG_ERR, 736 "nd6_na_input: duplicate IP6 address %s\n", 737 ip6_sprintf(ip6bufs, &taddr6)); 738 goto freeit; 739 } 740 741 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 742 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 743 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 744 ifp->if_addrlen, lladdrlen - 2)); 745 goto bad; 746 } 747 748 /* 749 * If no neighbor cache entry is found, NA SHOULD silently be 750 * discarded. 751 */ 752 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 753 if (ln == NULL) { 754 goto freeit; 755 } 756 757 /* 758 * Do not try to override static entry. 759 */ 760 if (ln->la_flags & LLE_STATIC) 761 goto freeit; 762 763 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 764 /* 765 * If the link-layer has address, and no lladdr option came, 766 * discard the packet. 767 */ 768 if (ifp->if_addrlen && lladdr == NULL) { 769 goto freeit; 770 } 771 772 /* 773 * Record link-layer address, and update the state. 774 */ 775 linkhdrsize = sizeof(linkhdr); 776 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 777 linkhdr, &linkhdrsize, &lladdr_off) != 0) 778 return; 779 780 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize, 781 lladdr_off) == 0) { 782 ln = NULL; 783 goto freeit; 784 } 785 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 786 if (is_solicited) 787 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 788 else 789 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 790 if ((ln->ln_router = is_router) != 0) { 791 /* 792 * This means a router's state has changed from 793 * non-reachable to probably reachable, and might 794 * affect the status of associated prefixes.. 795 */ 796 checklink = 1; 797 } 798 } else { 799 int llchange; 800 801 /* 802 * Check if the link-layer address has changed or not. 803 */ 804 if (lladdr == NULL) 805 llchange = 0; 806 else { 807 if (ln->la_flags & LLE_VALID) { 808 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 809 llchange = 1; 810 else 811 llchange = 0; 812 } else 813 llchange = 1; 814 } 815 816 /* 817 * This is VERY complex. Look at it with care. 818 * 819 * override solicit lladdr llchange action 820 * (L: record lladdr) 821 * 822 * 0 0 n -- (2c) 823 * 0 0 y n (2b) L 824 * 0 0 y y (1) REACHABLE->STALE 825 * 0 1 n -- (2c) *->REACHABLE 826 * 0 1 y n (2b) L *->REACHABLE 827 * 0 1 y y (1) REACHABLE->STALE 828 * 1 0 n -- (2a) 829 * 1 0 y n (2a) L 830 * 1 0 y y (2a) L *->STALE 831 * 1 1 n -- (2a) *->REACHABLE 832 * 1 1 y n (2a) L *->REACHABLE 833 * 1 1 y y (2a) L *->REACHABLE 834 */ 835 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 836 /* 837 * If state is REACHABLE, make it STALE. 838 * no other updates should be done. 839 */ 840 if (ln->ln_state == ND6_LLINFO_REACHABLE) 841 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 842 goto freeit; 843 } else if (is_override /* (2a) */ 844 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 845 || lladdr == NULL) { /* (2c) */ 846 /* 847 * Update link-local address, if any. 848 */ 849 if (lladdr != NULL) { 850 linkhdrsize = sizeof(linkhdr); 851 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 852 linkhdr, &linkhdrsize, &lladdr_off) != 0) 853 goto freeit; 854 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 855 linkhdrsize, lladdr_off) == 0) { 856 ln = NULL; 857 goto freeit; 858 } 859 EVENTHANDLER_INVOKE(lle_event, ln, 860 LLENTRY_RESOLVED); 861 } 862 863 /* 864 * If solicited, make the state REACHABLE. 865 * If not solicited and the link-layer address was 866 * changed, make it STALE. 867 */ 868 if (is_solicited) 869 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 870 else { 871 if (lladdr != NULL && llchange) 872 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 873 } 874 } 875 876 if (ln->ln_router && !is_router) { 877 /* 878 * The peer dropped the router flag. 879 * Remove the sender from the Default Router List and 880 * update the Destination Cache entries. 881 */ 882 struct ifnet *nd6_ifp; 883 884 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 885 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 886 (ND_IFINFO(nd6_ifp)->flags & 887 ND6_IFF_ACCEPT_RTADV) != 0) 888 /* 889 * Even if the neighbor is not in the default 890 * router list, the neighbor may be used as a 891 * next hop for some destinations (e.g. redirect 892 * case). So we must call rt6_flush explicitly. 893 */ 894 rt6_flush(&ip6->ip6_src, ifp); 895 } 896 ln->ln_router = is_router; 897 } 898 /* XXX - QL 899 * Does this matter? 900 * rt->rt_flags &= ~RTF_REJECT; 901 */ 902 ln->la_asked = 0; 903 if (ln->la_hold != NULL) { 904 memset(&sin6, 0, sizeof(sin6)); 905 nd6_grab_holdchain(ln, &chain, &sin6); 906 } 907 freeit: 908 if (ln != NULL) 909 LLE_WUNLOCK(ln); 910 911 if (chain != NULL) 912 nd6_flush_holdchain(ifp, chain, &sin6); 913 914 if (checklink) 915 pfxlist_onlink_check(); 916 917 m_freem(m); 918 return; 919 920 bad: 921 if (ln != NULL) 922 LLE_WUNLOCK(ln); 923 924 ICMP6STAT_INC(icp6s_badna); 925 m_freem(m); 926 } 927 928 /* 929 * Neighbor advertisement output handling. 930 * 931 * Based on RFC 2461 932 * 933 * the following items are not implemented yet: 934 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 935 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 936 * 937 * tlladdr - 1 if include target link-layer address 938 * sdl0 - sockaddr_dl (= proxy NA) or NULL 939 */ 940 static void 941 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 942 const struct in6_addr *taddr6, u_long flags, int tlladdr, 943 struct sockaddr *sdl0, u_int fibnum) 944 { 945 struct mbuf *m; 946 struct m_tag *mtag; 947 struct ip6_hdr *ip6; 948 struct nd_neighbor_advert *nd_na; 949 struct ip6_moptions im6o; 950 struct in6_addr daddr6, dst6, src6; 951 uint32_t scopeid; 952 953 int icmp6len, maxlen, error; 954 caddr_t mac = NULL; 955 956 daddr6 = *daddr6_0; /* make a local copy for modification */ 957 958 /* estimate the size of message */ 959 maxlen = sizeof(*ip6) + sizeof(*nd_na); 960 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 961 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 962 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 963 __func__, max_linkhdr, maxlen, MCLBYTES)); 964 965 if (max_linkhdr + maxlen > MHLEN) 966 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 967 else 968 m = m_gethdr(M_NOWAIT, MT_DATA); 969 if (m == NULL) 970 return; 971 M_SETFIB(m, fibnum); 972 973 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 974 m->m_flags |= M_MCAST; 975 im6o.im6o_multicast_ifp = ifp; 976 im6o.im6o_multicast_hlim = 255; 977 im6o.im6o_multicast_loop = 0; 978 } 979 980 icmp6len = sizeof(*nd_na); 981 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 982 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 983 984 /* fill neighbor advertisement packet */ 985 ip6 = mtod(m, struct ip6_hdr *); 986 ip6->ip6_flow = 0; 987 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 988 ip6->ip6_vfc |= IPV6_VERSION; 989 ip6->ip6_nxt = IPPROTO_ICMPV6; 990 ip6->ip6_hlim = 255; 991 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 992 /* reply to DAD */ 993 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 994 daddr6.s6_addr16[1] = 0; 995 daddr6.s6_addr32[1] = 0; 996 daddr6.s6_addr32[2] = 0; 997 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 998 if (in6_setscope(&daddr6, ifp, NULL)) 999 goto bad; 1000 1001 flags &= ~ND_NA_FLAG_SOLICITED; 1002 } 1003 ip6->ip6_dst = daddr6; 1004 1005 /* 1006 * Select a source whose scope is the same as that of the dest. 1007 */ 1008 in6_splitscope(&daddr6, &dst6, &scopeid); 1009 error = in6_selectsrc_addr(fibnum, &dst6, 1010 scopeid, ifp, &src6, NULL); 1011 if (error) { 1012 char ip6buf[INET6_ADDRSTRLEN]; 1013 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1014 "determined: dst=%s, error=%d\n", 1015 ip6_sprintf(ip6buf, &daddr6), error)); 1016 goto bad; 1017 } 1018 ip6->ip6_src = src6; 1019 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1020 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1021 nd_na->nd_na_code = 0; 1022 nd_na->nd_na_target = *taddr6; 1023 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1024 1025 /* 1026 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1027 * see nd6_ns_input() for details. 1028 * Basically, if NS packet is sent to unicast/anycast addr, 1029 * target lladdr option SHOULD NOT be included. 1030 */ 1031 if (tlladdr) { 1032 /* 1033 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1034 * lladdr in sdl0. If we are not proxying (sending NA for 1035 * my address) use lladdr configured for the interface. 1036 */ 1037 if (sdl0 == NULL) { 1038 if (ifp->if_carp) 1039 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1040 if (mac == NULL) 1041 mac = nd6_ifptomac(ifp); 1042 } else if (sdl0->sa_family == AF_LINK) { 1043 struct sockaddr_dl *sdl; 1044 sdl = (struct sockaddr_dl *)sdl0; 1045 if (sdl->sdl_alen == ifp->if_addrlen) 1046 mac = LLADDR(sdl); 1047 } 1048 } 1049 if (tlladdr && mac) { 1050 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1051 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1052 1053 /* roundup to 8 bytes alignment! */ 1054 optlen = (optlen + 7) & ~7; 1055 1056 m->m_pkthdr.len += optlen; 1057 m->m_len += optlen; 1058 icmp6len += optlen; 1059 bzero((caddr_t)nd_opt, optlen); 1060 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1061 nd_opt->nd_opt_len = optlen >> 3; 1062 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1063 } else 1064 flags &= ~ND_NA_FLAG_OVERRIDE; 1065 1066 ip6->ip6_plen = htons((u_short)icmp6len); 1067 nd_na->nd_na_flags_reserved = flags; 1068 nd_na->nd_na_cksum = 0; 1069 nd_na->nd_na_cksum = 1070 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1071 1072 if (send_sendso_input_hook != NULL) { 1073 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1074 sizeof(unsigned short), M_NOWAIT); 1075 if (mtag == NULL) 1076 goto bad; 1077 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1078 m_tag_prepend(m, mtag); 1079 } 1080 1081 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1082 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1083 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1084 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1085 1086 return; 1087 1088 bad: 1089 m_freem(m); 1090 } 1091 1092 #ifndef BURN_BRIDGES 1093 void 1094 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1095 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1096 struct sockaddr *sdl0) 1097 { 1098 1099 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1100 RT_DEFAULT_FIB); 1101 } 1102 #endif 1103 1104 caddr_t 1105 nd6_ifptomac(struct ifnet *ifp) 1106 { 1107 switch (ifp->if_type) { 1108 case IFT_ETHER: 1109 case IFT_IEEE1394: 1110 case IFT_L2VLAN: 1111 case IFT_INFINIBAND: 1112 case IFT_BRIDGE: 1113 return IF_LLADDR(ifp); 1114 default: 1115 return NULL; 1116 } 1117 } 1118 1119 struct dadq { 1120 TAILQ_ENTRY(dadq) dad_list; 1121 struct ifaddr *dad_ifa; 1122 int dad_count; /* max NS to send */ 1123 int dad_ns_tcount; /* # of trials to send NS */ 1124 int dad_ns_ocount; /* NS sent so far */ 1125 int dad_ns_icount; 1126 int dad_na_icount; 1127 int dad_ns_lcount; /* looped back NS */ 1128 int dad_loopbackprobe; /* probing state for loopback detection */ 1129 struct callout dad_timer_ch; 1130 struct vnet *dad_vnet; 1131 u_int dad_refcnt; 1132 #define ND_OPT_NONCE_LEN32 \ 1133 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1134 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1135 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */ 1136 }; 1137 1138 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq); 1139 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock); 1140 #define V_dadq VNET(dadq) 1141 #define V_dad_rwlock VNET(dad_rwlock) 1142 1143 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1144 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1145 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1146 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1147 1148 static void 1149 nd6_dad_add(struct dadq *dp) 1150 { 1151 1152 DADQ_WLOCK(); 1153 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1154 dp->dad_ondadq = true; 1155 DADQ_WUNLOCK(); 1156 } 1157 1158 static void 1159 nd6_dad_del(struct dadq *dp) 1160 { 1161 1162 DADQ_WLOCK(); 1163 if (dp->dad_ondadq) { 1164 /* 1165 * Remove dp from the dadq and release the dadq's 1166 * reference. 1167 */ 1168 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1169 dp->dad_ondadq = false; 1170 DADQ_WUNLOCK(); 1171 nd6_dad_rele(dp); 1172 } else 1173 DADQ_WUNLOCK(); 1174 } 1175 1176 static struct dadq * 1177 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1178 { 1179 struct dadq *dp; 1180 1181 DADQ_RLOCK(); 1182 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1183 if (dp->dad_ifa != ifa) 1184 continue; 1185 /* 1186 * Skip if the nonce matches the received one. 1187 * +2 in the length is required because of type and 1188 * length fields are included in a header. 1189 */ 1190 if (n != NULL && 1191 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1192 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1193 ND_OPT_NONCE_LEN) == 0) { 1194 dp->dad_ns_lcount++; 1195 continue; 1196 } 1197 refcount_acquire(&dp->dad_refcnt); 1198 break; 1199 } 1200 DADQ_RUNLOCK(); 1201 1202 return (dp); 1203 } 1204 1205 static void 1206 nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns) 1207 { 1208 1209 NET_EPOCH_ASSERT(); 1210 1211 if (send_ns != 0) 1212 nd6_dad_ns_output(dp); 1213 callout_reset(&dp->dad_timer_ch, ticks, 1214 (void (*)(void *))nd6_dad_timer, (void *)dp); 1215 } 1216 1217 static void 1218 nd6_dad_stoptimer(struct dadq *dp) 1219 { 1220 1221 callout_drain(&dp->dad_timer_ch); 1222 } 1223 1224 static void 1225 nd6_dad_rele(struct dadq *dp) 1226 { 1227 1228 if (refcount_release(&dp->dad_refcnt)) { 1229 ifa_free(dp->dad_ifa); 1230 free(dp, M_IP6NDP); 1231 } 1232 } 1233 1234 void 1235 nd6_dad_init(void) 1236 { 1237 1238 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1239 TAILQ_INIT(&V_dadq); 1240 } 1241 1242 /* 1243 * Start Duplicate Address Detection (DAD) for specified interface address. 1244 */ 1245 void 1246 nd6_dad_start(struct ifaddr *ifa, int delay) 1247 { 1248 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1249 struct dadq *dp; 1250 char ip6buf[INET6_ADDRSTRLEN]; 1251 struct epoch_tracker et; 1252 1253 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0, 1254 ("starting DAD on non-tentative address %p", ifa)); 1255 1256 /* 1257 * If we don't need DAD, don't do it. 1258 * There are several cases: 1259 * - DAD is disabled globally or on the interface 1260 * - the interface address is anycast 1261 */ 1262 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 || 1263 V_ip6_dad_count == 0 || 1264 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) != 0) { 1265 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1266 return; 1267 } 1268 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 || 1269 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || 1270 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) != 0) 1271 return; 1272 1273 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1274 /* 1275 * DAD is already in progress. Let the existing entry 1276 * finish it. 1277 */ 1278 nd6_dad_rele(dp); 1279 return; 1280 } 1281 1282 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1283 if (dp == NULL) { 1284 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1285 "%s(%s)\n", 1286 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1287 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1288 return; 1289 } 1290 callout_init(&dp->dad_timer_ch, 0); 1291 #ifdef VIMAGE 1292 dp->dad_vnet = curvnet; 1293 #endif 1294 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1295 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1296 1297 /* 1298 * Send NS packet for DAD, ip6_dad_count times. 1299 * Note that we must delay the first transmission, if this is the 1300 * first packet to be sent from the interface after interface 1301 * (re)initialization. 1302 */ 1303 dp->dad_ifa = ifa; 1304 ifa_ref(dp->dad_ifa); 1305 dp->dad_count = V_ip6_dad_count; 1306 dp->dad_ns_icount = dp->dad_na_icount = 0; 1307 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1308 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1309 1310 /* Add this to the dadq and add a reference for the dadq. */ 1311 refcount_init(&dp->dad_refcnt, 1); 1312 nd6_dad_add(dp); 1313 NET_EPOCH_ENTER(et); 1314 nd6_dad_starttimer(dp, delay, 0); 1315 NET_EPOCH_EXIT(et); 1316 } 1317 1318 /* 1319 * terminate DAD unconditionally. used for address removals. 1320 */ 1321 void 1322 nd6_dad_stop(struct ifaddr *ifa) 1323 { 1324 struct dadq *dp; 1325 1326 dp = nd6_dad_find(ifa, NULL); 1327 if (!dp) { 1328 /* DAD wasn't started yet */ 1329 return; 1330 } 1331 1332 nd6_dad_stoptimer(dp); 1333 nd6_dad_del(dp); 1334 1335 /* Release this function's reference, acquired by nd6_dad_find(). */ 1336 nd6_dad_rele(dp); 1337 } 1338 1339 static void 1340 nd6_dad_timer(struct dadq *dp) 1341 { 1342 CURVNET_SET(dp->dad_vnet); 1343 struct ifaddr *ifa = dp->dad_ifa; 1344 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1345 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1346 char ip6buf[INET6_ADDRSTRLEN]; 1347 struct epoch_tracker et; 1348 1349 KASSERT(ia != NULL, ("DAD entry %p with no address", dp)); 1350 1351 NET_EPOCH_ENTER(et); 1352 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1353 /* Do not need DAD for ifdisabled interface. */ 1354 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1355 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1356 goto err; 1357 } 1358 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1359 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1360 "%s(%s)\n", 1361 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1362 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1363 goto err; 1364 } 1365 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1366 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1367 "%s(%s)\n", 1368 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1369 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1370 goto err; 1371 } 1372 1373 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1374 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1375 (((ifp->if_flags & IFF_UP) == 0) || 1376 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1377 nd6log((LOG_INFO, "%s: could not run DAD " 1378 "because the interface was down or not running.\n", 1379 if_name(ifa->ifa_ifp))); 1380 goto err; 1381 } 1382 1383 /* Need more checks? */ 1384 if (dp->dad_ns_ocount < dp->dad_count) { 1385 /* 1386 * We have more NS to go. Send NS packet for DAD. 1387 */ 1388 nd6_dad_starttimer(dp, 1389 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1); 1390 goto done; 1391 } else { 1392 /* 1393 * We have transmitted sufficient number of DAD packets. 1394 * See what we've got. 1395 */ 1396 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1397 /* We've seen NS or NA, means DAD has failed. */ 1398 nd6_dad_duplicated(ifa, dp); 1399 else if (V_dad_enhanced != 0 && 1400 dp->dad_ns_lcount > 0 && 1401 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1402 /* 1403 * Sec. 4.1 in RFC 7527 requires transmission of 1404 * additional probes until the loopback condition 1405 * becomes clear when a looped back probe is detected. 1406 */ 1407 log(LOG_ERR, "%s: a looped back NS message is " 1408 "detected during DAD for %s. " 1409 "Another DAD probes are being sent.\n", 1410 if_name(ifa->ifa_ifp), 1411 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1412 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1413 /* 1414 * Send an NS immediately and increase dad_count by 1415 * V_nd6_mmaxtries - 1. 1416 */ 1417 dp->dad_count = 1418 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1419 nd6_dad_starttimer(dp, 1420 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1421 1); 1422 goto done; 1423 } else { 1424 /* 1425 * We are done with DAD. No NA came, no NS came. 1426 * No duplicate address found. Check IFDISABLED flag 1427 * again in case that it is changed between the 1428 * beginning of this function and here. 1429 */ 1430 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1431 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1432 1433 nd6log((LOG_DEBUG, 1434 "%s: DAD complete for %s - no duplicates found\n", 1435 if_name(ifa->ifa_ifp), 1436 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1437 if (dp->dad_ns_lcount > 0) 1438 log(LOG_ERR, "%s: DAD completed while " 1439 "a looped back NS message is detected " 1440 "during DAD for %s.\n", 1441 if_name(ifa->ifa_ifp), 1442 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1443 } 1444 } 1445 err: 1446 nd6_dad_del(dp); 1447 done: 1448 NET_EPOCH_EXIT(et); 1449 CURVNET_RESTORE(); 1450 } 1451 1452 static void 1453 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1454 { 1455 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1456 struct ifnet *ifp; 1457 char ip6buf[INET6_ADDRSTRLEN]; 1458 1459 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1460 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1461 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1462 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1463 dp->dad_na_icount); 1464 1465 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1466 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1467 1468 ifp = ifa->ifa_ifp; 1469 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1470 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1471 log(LOG_ERR, "%s: manual intervention required\n", 1472 if_name(ifp)); 1473 1474 /* 1475 * If the address is a link-local address formed from an interface 1476 * identifier based on the hardware address which is supposed to be 1477 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1478 * operation on the interface SHOULD be disabled. 1479 * [RFC 4862, Section 5.4.5] 1480 */ 1481 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1482 struct in6_addr in6; 1483 1484 /* 1485 * To avoid over-reaction, we only apply this logic when we are 1486 * very sure that hardware addresses are supposed to be unique. 1487 */ 1488 switch (ifp->if_type) { 1489 case IFT_ETHER: 1490 case IFT_ATM: 1491 case IFT_IEEE1394: 1492 case IFT_INFINIBAND: 1493 in6 = ia->ia_addr.sin6_addr; 1494 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1495 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1496 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1497 log(LOG_ERR, "%s: possible hardware address " 1498 "duplication detected, disable IPv6\n", 1499 if_name(ifp)); 1500 } 1501 break; 1502 } 1503 } 1504 } 1505 1506 static void 1507 nd6_dad_ns_output(struct dadq *dp) 1508 { 1509 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1510 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1511 int i; 1512 1513 dp->dad_ns_tcount++; 1514 if ((ifp->if_flags & IFF_UP) == 0) { 1515 return; 1516 } 1517 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1518 return; 1519 } 1520 1521 dp->dad_ns_ocount++; 1522 if (V_dad_enhanced != 0) { 1523 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1524 dp->dad_nonce[i] = arc4random(); 1525 /* 1526 * XXXHRS: Note that in the case that 1527 * DupAddrDetectTransmits > 1, multiple NS messages with 1528 * different nonces can be looped back in an unexpected 1529 * order. The current implementation recognizes only 1530 * the latest nonce on the sender side. Practically it 1531 * should work well in almost all cases. 1532 */ 1533 } 1534 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1535 (uint8_t *)&dp->dad_nonce[0]); 1536 } 1537 1538 static void 1539 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1540 { 1541 struct dadq *dp; 1542 1543 if (ifa == NULL) 1544 panic("ifa == NULL in nd6_dad_ns_input"); 1545 1546 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1547 if (V_dad_enhanced == 0) 1548 ndopt_nonce = NULL; 1549 dp = nd6_dad_find(ifa, ndopt_nonce); 1550 if (dp == NULL) 1551 return; 1552 1553 dp->dad_ns_icount++; 1554 nd6_dad_rele(dp); 1555 } 1556 1557 static void 1558 nd6_dad_na_input(struct ifaddr *ifa) 1559 { 1560 struct dadq *dp; 1561 1562 if (ifa == NULL) 1563 panic("ifa == NULL in nd6_dad_na_input"); 1564 1565 dp = nd6_dad_find(ifa, NULL); 1566 if (dp != NULL) { 1567 dp->dad_na_icount++; 1568 nd6_dad_rele(dp); 1569 } 1570 } 1571