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