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 = m->m_pkthdr.rcvif; 125 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 126 struct nd_neighbor_solicit *nd_ns; 127 struct in6_addr saddr6 = ip6->ip6_src; 128 struct in6_addr daddr6 = ip6->ip6_dst; 129 struct in6_addr taddr6; 130 struct in6_addr myaddr6; 131 char *lladdr = NULL; 132 struct ifaddr *ifa = NULL; 133 int lladdrlen = 0; 134 int anycast = 0, proxy = 0, tentative = 0; 135 int tlladdr; 136 int rflag; 137 union nd_opts ndopts; 138 struct sockaddr_dl proxydl; 139 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 140 141 /* RFC 6980: Nodes MUST silently ignore fragments */ 142 if(m->m_flags & M_FRAGMENTED) 143 goto freeit; 144 145 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 146 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 147 rflag = 0; 148 #ifndef PULLDOWN_TEST 149 IP6_EXTHDR_CHECK(m, off, icmp6len,); 150 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 151 #else 152 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); 153 if (nd_ns == NULL) { 154 ICMP6STAT_INC(icp6s_tooshort); 155 return; 156 } 157 #endif 158 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ 159 taddr6 = nd_ns->nd_ns_target; 160 if (in6_setscope(&taddr6, ifp, NULL) != 0) 161 goto bad; 162 163 if (ip6->ip6_hlim != 255) { 164 nd6log((LOG_ERR, 165 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 166 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 167 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 168 goto bad; 169 } 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 if (ndopts.nd_opts_src_lladdr) { 219 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 220 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 221 } 222 223 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 224 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 225 "(link-layer address option)\n")); 226 goto bad; 227 } 228 229 /* 230 * Attaching target link-layer address to the NA? 231 * (RFC 2461 7.2.4) 232 * 233 * NS IP dst is unicast/anycast MUST NOT add 234 * NS IP dst is solicited-node multicast MUST add 235 * 236 * In implementation, we add target link-layer address by default. 237 * We do not add one in MUST NOT cases. 238 */ 239 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 240 tlladdr = 0; 241 else 242 tlladdr = 1; 243 244 /* 245 * Target address (taddr6) must be either: 246 * (1) Valid unicast/anycast address for my receiving interface, 247 * (2) Unicast address for which I'm offering proxy service, or 248 * (3) "tentative" address on which DAD is being performed. 249 */ 250 /* (1) and (3) check. */ 251 if (ifp->if_carp) 252 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 253 else 254 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 255 256 /* (2) check. */ 257 if (ifa == NULL) { 258 struct sockaddr_dl rt_gateway; 259 struct rt_addrinfo info; 260 struct sockaddr_in6 dst6; 261 262 bzero(&dst6, sizeof(dst6)); 263 dst6.sin6_len = sizeof(struct sockaddr_in6); 264 dst6.sin6_family = AF_INET6; 265 dst6.sin6_addr = taddr6; 266 267 bzero(&rt_gateway, sizeof(rt_gateway)); 268 rt_gateway.sdl_len = sizeof(rt_gateway); 269 bzero(&info, sizeof(info)); 270 info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway; 271 272 if (rib_lookup_info(ifp->if_fib, (struct sockaddr *)&dst6, 273 0, 0, &info) == 0) { 274 if ((info.rti_flags & RTF_ANNOUNCE) != 0 && 275 rt_gateway.sdl_family == AF_LINK) { 276 277 /* 278 * proxy NDP for single entry 279 */ 280 proxydl = *SDL(&rt_gateway); 281 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal( 282 ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 283 if (ifa) 284 proxy = 1; 285 } 286 } 287 } 288 if (ifa == NULL) { 289 /* 290 * We've got an NS packet, and we don't have that adddress 291 * assigned for us. We MUST silently ignore it. 292 * See RFC2461 7.2.3. 293 */ 294 goto freeit; 295 } 296 myaddr6 = *IFA_IN6(ifa); 297 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 298 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 299 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 300 goto freeit; 301 302 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 303 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 304 "(if %d, NS packet %d)\n", 305 ip6_sprintf(ip6bufs, &taddr6), 306 ifp->if_addrlen, lladdrlen - 2)); 307 goto bad; 308 } 309 310 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 311 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 312 ip6_sprintf(ip6bufs, &saddr6))); 313 goto freeit; 314 } 315 316 /* 317 * We have neighbor solicitation packet, with target address equals to 318 * one of my tentative address. 319 * 320 * src addr how to process? 321 * --- --- 322 * multicast of course, invalid (rejected in ip6_input) 323 * unicast somebody is doing address resolution -> ignore 324 * unspec dup address detection 325 * 326 * The processing is defined in RFC 2462. 327 */ 328 if (tentative) { 329 /* 330 * If source address is unspecified address, it is for 331 * duplicate address detection. 332 * 333 * If not, the packet is for addess resolution; 334 * silently ignore it. 335 */ 336 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 337 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 338 339 goto freeit; 340 } 341 342 /* 343 * If the source address is unspecified address, entries must not 344 * be created or updated. 345 * It looks that sender is performing DAD. Output NA toward 346 * all-node multicast address, to tell the sender that I'm using 347 * the address. 348 * S bit ("solicited") must be zero. 349 */ 350 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 351 struct in6_addr in6_all; 352 353 in6_all = in6addr_linklocal_allnodes; 354 if (in6_setscope(&in6_all, ifp, NULL) != 0) 355 goto bad; 356 nd6_na_output_fib(ifp, &in6_all, &taddr6, 357 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 358 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 359 M_GETFIB(m)); 360 goto freeit; 361 } 362 363 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 364 ND_NEIGHBOR_SOLICIT, 0); 365 366 nd6_na_output_fib(ifp, &saddr6, &taddr6, 367 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 368 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 369 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 370 freeit: 371 if (ifa != NULL) 372 ifa_free(ifa); 373 m_freem(m); 374 return; 375 376 bad: 377 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 378 ip6_sprintf(ip6bufs, &saddr6))); 379 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 380 ip6_sprintf(ip6bufs, &daddr6))); 381 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 382 ip6_sprintf(ip6bufs, &taddr6))); 383 ICMP6STAT_INC(icp6s_badns); 384 if (ifa != NULL) 385 ifa_free(ifa); 386 m_freem(m); 387 } 388 389 /* 390 * Output a Neighbor Solicitation Message. Caller specifies: 391 * - ICMP6 header source IP6 address 392 * - ND6 header target IP6 address 393 * - ND6 header source datalink address 394 * 395 * Based on RFC 2461 396 * Based on RFC 2462 (duplicate address detection) 397 * 398 * ln - for source address determination 399 * nonce - If non-NULL, NS is used for duplicate address detection and 400 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 401 */ 402 static void 403 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 404 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 405 uint8_t *nonce, u_int fibnum) 406 { 407 struct mbuf *m; 408 struct m_tag *mtag; 409 struct ip6_hdr *ip6; 410 struct nd_neighbor_solicit *nd_ns; 411 struct ip6_moptions im6o; 412 int icmp6len; 413 int maxlen; 414 caddr_t mac; 415 416 if (IN6_IS_ADDR_MULTICAST(taddr6)) 417 return; 418 419 /* estimate the size of message */ 420 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 421 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 422 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 423 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 424 __func__, max_linkhdr, maxlen, MCLBYTES)); 425 426 if (max_linkhdr + maxlen > MHLEN) 427 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 428 else 429 m = m_gethdr(M_NOWAIT, MT_DATA); 430 if (m == NULL) 431 return; 432 M_SETFIB(m, fibnum); 433 434 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 435 m->m_flags |= M_MCAST; 436 im6o.im6o_multicast_ifp = ifp; 437 im6o.im6o_multicast_hlim = 255; 438 im6o.im6o_multicast_loop = 0; 439 } 440 441 icmp6len = sizeof(*nd_ns); 442 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 443 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 444 445 /* fill neighbor solicitation packet */ 446 ip6 = mtod(m, struct ip6_hdr *); 447 ip6->ip6_flow = 0; 448 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 449 ip6->ip6_vfc |= IPV6_VERSION; 450 /* ip6->ip6_plen will be set later */ 451 ip6->ip6_nxt = IPPROTO_ICMPV6; 452 ip6->ip6_hlim = 255; 453 if (daddr6) 454 ip6->ip6_dst = *daddr6; 455 else { 456 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 457 ip6->ip6_dst.s6_addr16[1] = 0; 458 ip6->ip6_dst.s6_addr32[1] = 0; 459 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 460 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 461 ip6->ip6_dst.s6_addr8[12] = 0xff; 462 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 463 goto bad; 464 } 465 if (nonce == NULL) { 466 struct ifaddr *ifa = NULL; 467 468 /* 469 * RFC2461 7.2.2: 470 * "If the source address of the packet prompting the 471 * solicitation is the same as one of the addresses assigned 472 * to the outgoing interface, that address SHOULD be placed 473 * in the IP Source Address of the outgoing solicitation. 474 * Otherwise, any one of the addresses assigned to the 475 * interface should be used." 476 * 477 * We use the source address for the prompting packet 478 * (saddr6), if saddr6 belongs to the outgoing interface. 479 * Otherwise, we perform the source address selection as usual. 480 */ 481 482 if (saddr6 != NULL) 483 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 484 if (ifa != NULL) { 485 /* ip6_src set already. */ 486 ip6->ip6_src = *saddr6; 487 ifa_free(ifa); 488 } else { 489 int error; 490 struct in6_addr dst6, src6; 491 uint32_t scopeid; 492 493 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); 494 error = in6_selectsrc_addr(fibnum, &dst6, 495 scopeid, ifp, &src6, NULL); 496 if (error) { 497 char ip6buf[INET6_ADDRSTRLEN]; 498 nd6log((LOG_DEBUG, "%s: source can't be " 499 "determined: dst=%s, error=%d\n", __func__, 500 ip6_sprintf(ip6buf, &dst6), 501 error)); 502 goto bad; 503 } 504 ip6->ip6_src = src6; 505 } 506 } else { 507 /* 508 * Source address for DAD packet must always be IPv6 509 * unspecified address. (0::0) 510 * We actually don't have to 0-clear the address (we did it 511 * above), but we do so here explicitly to make the intention 512 * clearer. 513 */ 514 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 515 } 516 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 517 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 518 nd_ns->nd_ns_code = 0; 519 nd_ns->nd_ns_reserved = 0; 520 nd_ns->nd_ns_target = *taddr6; 521 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 522 523 /* 524 * Add source link-layer address option. 525 * 526 * spec implementation 527 * --- --- 528 * DAD packet MUST NOT do not add the option 529 * there's no link layer address: 530 * impossible do not add the option 531 * there's link layer address: 532 * Multicast NS MUST add one add the option 533 * Unicast NS SHOULD add one add the option 534 */ 535 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 536 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 537 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 538 /* 8 byte alignments... */ 539 optlen = (optlen + 7) & ~7; 540 541 m->m_pkthdr.len += optlen; 542 m->m_len += optlen; 543 icmp6len += optlen; 544 bzero((caddr_t)nd_opt, optlen); 545 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 546 nd_opt->nd_opt_len = optlen >> 3; 547 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 548 } 549 /* 550 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 551 * This behavior is documented as Enhanced Duplicate Address 552 * Detection in RFC 7527. 553 * net.inet6.ip6.dad_enhanced=0 disables this. 554 */ 555 if (V_dad_enhanced != 0 && nonce != NULL) { 556 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 557 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 558 /* 8-byte alignment is required. */ 559 optlen = (optlen + 7) & ~7; 560 561 m->m_pkthdr.len += optlen; 562 m->m_len += optlen; 563 icmp6len += optlen; 564 bzero((caddr_t)nd_opt, optlen); 565 nd_opt->nd_opt_type = ND_OPT_NONCE; 566 nd_opt->nd_opt_len = optlen >> 3; 567 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 568 } 569 ip6->ip6_plen = htons((u_short)icmp6len); 570 nd_ns->nd_ns_cksum = 0; 571 nd_ns->nd_ns_cksum = 572 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 573 574 if (send_sendso_input_hook != NULL) { 575 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 576 sizeof(unsigned short), M_NOWAIT); 577 if (mtag == NULL) 578 goto bad; 579 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 580 m_tag_prepend(m, mtag); 581 } 582 583 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 584 &im6o, NULL, NULL); 585 icmp6_ifstat_inc(ifp, ifs6_out_msg); 586 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 587 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 588 589 return; 590 591 bad: 592 m_freem(m); 593 } 594 595 #ifndef BURN_BRIDGES 596 void 597 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 598 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 599 { 600 601 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 602 } 603 #endif 604 /* 605 * Neighbor advertisement input handling. 606 * 607 * Based on RFC 2461 608 * Based on RFC 2462 (duplicate address detection) 609 * 610 * the following items are not implemented yet: 611 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 612 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 613 */ 614 void 615 nd6_na_input(struct mbuf *m, int off, int icmp6len) 616 { 617 struct ifnet *ifp = m->m_pkthdr.rcvif; 618 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 619 struct nd_neighbor_advert *nd_na; 620 struct in6_addr daddr6 = ip6->ip6_dst; 621 struct in6_addr taddr6; 622 int flags; 623 int is_router; 624 int is_solicited; 625 int is_override; 626 char *lladdr = NULL; 627 int lladdrlen = 0; 628 int checklink = 0; 629 struct ifaddr *ifa; 630 struct llentry *ln = NULL; 631 union nd_opts ndopts; 632 struct mbuf *chain = NULL; 633 struct sockaddr_in6 sin6; 634 u_char linkhdr[LLE_MAX_LINKHDR]; 635 size_t linkhdrsize; 636 int lladdr_off; 637 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 638 639 NET_EPOCH_ASSERT(); 640 641 /* RFC 6980: Nodes MUST silently ignore fragments */ 642 if(m->m_flags & M_FRAGMENTED) 643 goto freeit; 644 645 if (ip6->ip6_hlim != 255) { 646 nd6log((LOG_ERR, 647 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 648 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 649 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 650 goto bad; 651 } 652 653 #ifndef PULLDOWN_TEST 654 IP6_EXTHDR_CHECK(m, off, icmp6len,); 655 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 656 #else 657 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 658 if (nd_na == NULL) { 659 ICMP6STAT_INC(icp6s_tooshort); 660 return; 661 } 662 #endif 663 664 flags = nd_na->nd_na_flags_reserved; 665 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 666 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 667 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 668 memset(&sin6, 0, sizeof(sin6)); 669 670 taddr6 = nd_na->nd_na_target; 671 if (in6_setscope(&taddr6, ifp, NULL)) 672 goto bad; /* XXX: impossible */ 673 674 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 675 nd6log((LOG_ERR, 676 "nd6_na_input: invalid target address %s\n", 677 ip6_sprintf(ip6bufs, &taddr6))); 678 goto bad; 679 } 680 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 681 if (is_solicited) { 682 nd6log((LOG_ERR, 683 "nd6_na_input: a solicited adv is multicasted\n")); 684 goto bad; 685 } 686 687 icmp6len -= sizeof(*nd_na); 688 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 689 if (nd6_options(&ndopts) < 0) { 690 nd6log((LOG_INFO, 691 "nd6_na_input: invalid ND option, ignored\n")); 692 /* nd6_options have incremented stats */ 693 goto freeit; 694 } 695 696 if (ndopts.nd_opts_tgt_lladdr) { 697 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 698 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 699 } 700 701 /* 702 * This effectively disables the DAD check on a non-master CARP 703 * address. 704 */ 705 if (ifp->if_carp) 706 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 707 else 708 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 709 710 /* 711 * Target address matches one of my interface address. 712 * 713 * If my address is tentative, this means that there's somebody 714 * already using the same address as mine. This indicates DAD failure. 715 * This is defined in RFC 2462. 716 * 717 * Otherwise, process as defined in RFC 2461. 718 */ 719 if (ifa 720 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 721 nd6_dad_na_input(ifa); 722 ifa_free(ifa); 723 goto freeit; 724 } 725 726 /* Just for safety, maybe unnecessary. */ 727 if (ifa) { 728 ifa_free(ifa); 729 log(LOG_ERR, 730 "nd6_na_input: duplicate IP6 address %s\n", 731 ip6_sprintf(ip6bufs, &taddr6)); 732 goto freeit; 733 } 734 735 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 736 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 737 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 738 ifp->if_addrlen, lladdrlen - 2)); 739 goto bad; 740 } 741 742 /* 743 * If no neighbor cache entry is found, NA SHOULD silently be 744 * discarded. 745 */ 746 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 747 if (ln == NULL) { 748 goto freeit; 749 } 750 751 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 752 /* 753 * If the link-layer has address, and no lladdr option came, 754 * discard the packet. 755 */ 756 if (ifp->if_addrlen && lladdr == NULL) { 757 goto freeit; 758 } 759 760 /* 761 * Record link-layer address, and update the state. 762 */ 763 linkhdrsize = sizeof(linkhdr); 764 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 765 linkhdr, &linkhdrsize, &lladdr_off) != 0) 766 return; 767 768 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize, 769 lladdr_off) == 0) { 770 ln = NULL; 771 goto freeit; 772 } 773 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 774 if (is_solicited) 775 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 776 else 777 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 778 if ((ln->ln_router = is_router) != 0) { 779 /* 780 * This means a router's state has changed from 781 * non-reachable to probably reachable, and might 782 * affect the status of associated prefixes.. 783 */ 784 checklink = 1; 785 } 786 } else { 787 int llchange; 788 789 /* 790 * Check if the link-layer address has changed or not. 791 */ 792 if (lladdr == NULL) 793 llchange = 0; 794 else { 795 if (ln->la_flags & LLE_VALID) { 796 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 797 llchange = 1; 798 else 799 llchange = 0; 800 } else 801 llchange = 1; 802 } 803 804 /* 805 * This is VERY complex. Look at it with care. 806 * 807 * override solicit lladdr llchange action 808 * (L: record lladdr) 809 * 810 * 0 0 n -- (2c) 811 * 0 0 y n (2b) L 812 * 0 0 y y (1) REACHABLE->STALE 813 * 0 1 n -- (2c) *->REACHABLE 814 * 0 1 y n (2b) L *->REACHABLE 815 * 0 1 y y (1) REACHABLE->STALE 816 * 1 0 n -- (2a) 817 * 1 0 y n (2a) L 818 * 1 0 y y (2a) L *->STALE 819 * 1 1 n -- (2a) *->REACHABLE 820 * 1 1 y n (2a) L *->REACHABLE 821 * 1 1 y y (2a) L *->REACHABLE 822 */ 823 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 824 /* 825 * If state is REACHABLE, make it STALE. 826 * no other updates should be done. 827 */ 828 if (ln->ln_state == ND6_LLINFO_REACHABLE) 829 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 830 goto freeit; 831 } else if (is_override /* (2a) */ 832 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 833 || lladdr == NULL) { /* (2c) */ 834 /* 835 * Update link-local address, if any. 836 */ 837 if (lladdr != NULL) { 838 linkhdrsize = sizeof(linkhdr); 839 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 840 linkhdr, &linkhdrsize, &lladdr_off) != 0) 841 goto freeit; 842 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 843 linkhdrsize, lladdr_off) == 0) { 844 ln = NULL; 845 goto freeit; 846 } 847 EVENTHANDLER_INVOKE(lle_event, ln, 848 LLENTRY_RESOLVED); 849 } 850 851 /* 852 * If solicited, make the state REACHABLE. 853 * If not solicited and the link-layer address was 854 * changed, make it STALE. 855 */ 856 if (is_solicited) 857 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 858 else { 859 if (lladdr != NULL && llchange) 860 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 861 } 862 } 863 864 if (ln->ln_router && !is_router) { 865 /* 866 * The peer dropped the router flag. 867 * Remove the sender from the Default Router List and 868 * update the Destination Cache entries. 869 */ 870 struct ifnet *nd6_ifp; 871 872 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 873 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 874 (ND_IFINFO(nd6_ifp)->flags & 875 ND6_IFF_ACCEPT_RTADV) != 0) 876 /* 877 * Even if the neighbor is not in the default 878 * router list, the neighbor may be used as a 879 * next hop for some destinations (e.g. redirect 880 * case). So we must call rt6_flush explicitly. 881 */ 882 rt6_flush(&ip6->ip6_src, ifp); 883 } 884 ln->ln_router = is_router; 885 } 886 /* XXX - QL 887 * Does this matter? 888 * rt->rt_flags &= ~RTF_REJECT; 889 */ 890 ln->la_asked = 0; 891 if (ln->la_hold != NULL) 892 nd6_grab_holdchain(ln, &chain, &sin6); 893 freeit: 894 if (ln != NULL) 895 LLE_WUNLOCK(ln); 896 897 if (chain != NULL) 898 nd6_flush_holdchain(ifp, chain, &sin6); 899 900 if (checklink) 901 pfxlist_onlink_check(); 902 903 m_freem(m); 904 return; 905 906 bad: 907 if (ln != NULL) 908 LLE_WUNLOCK(ln); 909 910 ICMP6STAT_INC(icp6s_badna); 911 m_freem(m); 912 } 913 914 /* 915 * Neighbor advertisement output handling. 916 * 917 * Based on RFC 2461 918 * 919 * the following items are not implemented yet: 920 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 921 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 922 * 923 * tlladdr - 1 if include target link-layer address 924 * sdl0 - sockaddr_dl (= proxy NA) or NULL 925 */ 926 static void 927 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 928 const struct in6_addr *taddr6, u_long flags, int tlladdr, 929 struct sockaddr *sdl0, u_int fibnum) 930 { 931 struct mbuf *m; 932 struct m_tag *mtag; 933 struct ip6_hdr *ip6; 934 struct nd_neighbor_advert *nd_na; 935 struct ip6_moptions im6o; 936 struct in6_addr daddr6, dst6, src6; 937 uint32_t scopeid; 938 939 int icmp6len, maxlen, error; 940 caddr_t mac = NULL; 941 942 daddr6 = *daddr6_0; /* make a local copy for modification */ 943 944 /* estimate the size of message */ 945 maxlen = sizeof(*ip6) + sizeof(*nd_na); 946 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 947 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 948 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 949 __func__, max_linkhdr, maxlen, MCLBYTES)); 950 951 if (max_linkhdr + maxlen > MHLEN) 952 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 953 else 954 m = m_gethdr(M_NOWAIT, MT_DATA); 955 if (m == NULL) 956 return; 957 M_SETFIB(m, fibnum); 958 959 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 960 m->m_flags |= M_MCAST; 961 im6o.im6o_multicast_ifp = ifp; 962 im6o.im6o_multicast_hlim = 255; 963 im6o.im6o_multicast_loop = 0; 964 } 965 966 icmp6len = sizeof(*nd_na); 967 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 968 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 969 970 /* fill neighbor advertisement packet */ 971 ip6 = mtod(m, struct ip6_hdr *); 972 ip6->ip6_flow = 0; 973 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 974 ip6->ip6_vfc |= IPV6_VERSION; 975 ip6->ip6_nxt = IPPROTO_ICMPV6; 976 ip6->ip6_hlim = 255; 977 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 978 /* reply to DAD */ 979 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 980 daddr6.s6_addr16[1] = 0; 981 daddr6.s6_addr32[1] = 0; 982 daddr6.s6_addr32[2] = 0; 983 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 984 if (in6_setscope(&daddr6, ifp, NULL)) 985 goto bad; 986 987 flags &= ~ND_NA_FLAG_SOLICITED; 988 } 989 ip6->ip6_dst = daddr6; 990 991 /* 992 * Select a source whose scope is the same as that of the dest. 993 */ 994 in6_splitscope(&daddr6, &dst6, &scopeid); 995 error = in6_selectsrc_addr(fibnum, &dst6, 996 scopeid, ifp, &src6, NULL); 997 if (error) { 998 char ip6buf[INET6_ADDRSTRLEN]; 999 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1000 "determined: dst=%s, error=%d\n", 1001 ip6_sprintf(ip6buf, &daddr6), error)); 1002 goto bad; 1003 } 1004 ip6->ip6_src = src6; 1005 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1006 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1007 nd_na->nd_na_code = 0; 1008 nd_na->nd_na_target = *taddr6; 1009 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1010 1011 /* 1012 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1013 * see nd6_ns_input() for details. 1014 * Basically, if NS packet is sent to unicast/anycast addr, 1015 * target lladdr option SHOULD NOT be included. 1016 */ 1017 if (tlladdr) { 1018 /* 1019 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1020 * lladdr in sdl0. If we are not proxying (sending NA for 1021 * my address) use lladdr configured for the interface. 1022 */ 1023 if (sdl0 == NULL) { 1024 if (ifp->if_carp) 1025 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1026 if (mac == NULL) 1027 mac = nd6_ifptomac(ifp); 1028 } else if (sdl0->sa_family == AF_LINK) { 1029 struct sockaddr_dl *sdl; 1030 sdl = (struct sockaddr_dl *)sdl0; 1031 if (sdl->sdl_alen == ifp->if_addrlen) 1032 mac = LLADDR(sdl); 1033 } 1034 } 1035 if (tlladdr && mac) { 1036 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1037 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1038 1039 /* roundup to 8 bytes alignment! */ 1040 optlen = (optlen + 7) & ~7; 1041 1042 m->m_pkthdr.len += optlen; 1043 m->m_len += optlen; 1044 icmp6len += optlen; 1045 bzero((caddr_t)nd_opt, optlen); 1046 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1047 nd_opt->nd_opt_len = optlen >> 3; 1048 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1049 } else 1050 flags &= ~ND_NA_FLAG_OVERRIDE; 1051 1052 ip6->ip6_plen = htons((u_short)icmp6len); 1053 nd_na->nd_na_flags_reserved = flags; 1054 nd_na->nd_na_cksum = 0; 1055 nd_na->nd_na_cksum = 1056 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1057 1058 if (send_sendso_input_hook != NULL) { 1059 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1060 sizeof(unsigned short), M_NOWAIT); 1061 if (mtag == NULL) 1062 goto bad; 1063 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1064 m_tag_prepend(m, mtag); 1065 } 1066 1067 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1068 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1069 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1070 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1071 1072 return; 1073 1074 bad: 1075 m_freem(m); 1076 } 1077 1078 #ifndef BURN_BRIDGES 1079 void 1080 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1081 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1082 struct sockaddr *sdl0) 1083 { 1084 1085 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1086 RT_DEFAULT_FIB); 1087 } 1088 #endif 1089 1090 caddr_t 1091 nd6_ifptomac(struct ifnet *ifp) 1092 { 1093 switch (ifp->if_type) { 1094 case IFT_ETHER: 1095 case IFT_IEEE1394: 1096 case IFT_L2VLAN: 1097 case IFT_INFINIBAND: 1098 case IFT_BRIDGE: 1099 return IF_LLADDR(ifp); 1100 default: 1101 return NULL; 1102 } 1103 } 1104 1105 struct dadq { 1106 TAILQ_ENTRY(dadq) dad_list; 1107 struct ifaddr *dad_ifa; 1108 int dad_count; /* max NS to send */ 1109 int dad_ns_tcount; /* # of trials to send NS */ 1110 int dad_ns_ocount; /* NS sent so far */ 1111 int dad_ns_icount; 1112 int dad_na_icount; 1113 int dad_ns_lcount; /* looped back NS */ 1114 int dad_loopbackprobe; /* probing state for loopback detection */ 1115 struct callout dad_timer_ch; 1116 struct vnet *dad_vnet; 1117 u_int dad_refcnt; 1118 #define ND_OPT_NONCE_LEN32 \ 1119 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1120 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1121 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */ 1122 }; 1123 1124 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq); 1125 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock); 1126 #define V_dadq VNET(dadq) 1127 #define V_dad_rwlock VNET(dad_rwlock) 1128 1129 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1130 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1131 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1132 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1133 1134 static void 1135 nd6_dad_add(struct dadq *dp) 1136 { 1137 1138 DADQ_WLOCK(); 1139 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1140 dp->dad_ondadq = true; 1141 DADQ_WUNLOCK(); 1142 } 1143 1144 static void 1145 nd6_dad_del(struct dadq *dp) 1146 { 1147 1148 DADQ_WLOCK(); 1149 if (dp->dad_ondadq) { 1150 /* 1151 * Remove dp from the dadq and release the dadq's 1152 * reference. 1153 */ 1154 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1155 dp->dad_ondadq = false; 1156 DADQ_WUNLOCK(); 1157 nd6_dad_rele(dp); 1158 } else 1159 DADQ_WUNLOCK(); 1160 } 1161 1162 static struct dadq * 1163 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1164 { 1165 struct dadq *dp; 1166 1167 DADQ_RLOCK(); 1168 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1169 if (dp->dad_ifa != ifa) 1170 continue; 1171 /* 1172 * Skip if the nonce matches the received one. 1173 * +2 in the length is required because of type and 1174 * length fields are included in a header. 1175 */ 1176 if (n != NULL && 1177 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1178 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1179 ND_OPT_NONCE_LEN) == 0) { 1180 dp->dad_ns_lcount++; 1181 continue; 1182 } 1183 refcount_acquire(&dp->dad_refcnt); 1184 break; 1185 } 1186 DADQ_RUNLOCK(); 1187 1188 return (dp); 1189 } 1190 1191 static void 1192 nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns) 1193 { 1194 1195 NET_EPOCH_ASSERT(); 1196 1197 if (send_ns != 0) 1198 nd6_dad_ns_output(dp); 1199 callout_reset(&dp->dad_timer_ch, ticks, 1200 (void (*)(void *))nd6_dad_timer, (void *)dp); 1201 } 1202 1203 static void 1204 nd6_dad_stoptimer(struct dadq *dp) 1205 { 1206 1207 callout_drain(&dp->dad_timer_ch); 1208 } 1209 1210 static void 1211 nd6_dad_rele(struct dadq *dp) 1212 { 1213 1214 if (refcount_release(&dp->dad_refcnt)) { 1215 ifa_free(dp->dad_ifa); 1216 free(dp, M_IP6NDP); 1217 } 1218 } 1219 1220 void 1221 nd6_dad_init(void) 1222 { 1223 1224 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1225 TAILQ_INIT(&V_dadq); 1226 } 1227 1228 /* 1229 * Start Duplicate Address Detection (DAD) for specified interface address. 1230 */ 1231 void 1232 nd6_dad_start(struct ifaddr *ifa, int delay) 1233 { 1234 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1235 struct dadq *dp; 1236 char ip6buf[INET6_ADDRSTRLEN]; 1237 struct epoch_tracker et; 1238 1239 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0, 1240 ("starting DAD on non-tentative address %p", ifa)); 1241 1242 /* 1243 * If we don't need DAD, don't do it. 1244 * There are several cases: 1245 * - DAD is disabled globally or on the interface 1246 * - the interface address is anycast 1247 */ 1248 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 || 1249 V_ip6_dad_count == 0 || 1250 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) != 0) { 1251 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1252 return; 1253 } 1254 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 || 1255 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || 1256 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) != 0) 1257 return; 1258 1259 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1260 /* 1261 * DAD is already in progress. Let the existing entry 1262 * finish it. 1263 */ 1264 nd6_dad_rele(dp); 1265 return; 1266 } 1267 1268 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1269 if (dp == NULL) { 1270 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1271 "%s(%s)\n", 1272 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1273 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1274 return; 1275 } 1276 callout_init(&dp->dad_timer_ch, 0); 1277 #ifdef VIMAGE 1278 dp->dad_vnet = curvnet; 1279 #endif 1280 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1281 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1282 1283 /* 1284 * Send NS packet for DAD, ip6_dad_count times. 1285 * Note that we must delay the first transmission, if this is the 1286 * first packet to be sent from the interface after interface 1287 * (re)initialization. 1288 */ 1289 dp->dad_ifa = ifa; 1290 ifa_ref(dp->dad_ifa); 1291 dp->dad_count = V_ip6_dad_count; 1292 dp->dad_ns_icount = dp->dad_na_icount = 0; 1293 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1294 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1295 1296 /* Add this to the dadq and add a reference for the dadq. */ 1297 refcount_init(&dp->dad_refcnt, 1); 1298 nd6_dad_add(dp); 1299 NET_EPOCH_ENTER(et); 1300 nd6_dad_starttimer(dp, delay, 0); 1301 NET_EPOCH_EXIT(et); 1302 } 1303 1304 /* 1305 * terminate DAD unconditionally. used for address removals. 1306 */ 1307 void 1308 nd6_dad_stop(struct ifaddr *ifa) 1309 { 1310 struct dadq *dp; 1311 1312 dp = nd6_dad_find(ifa, NULL); 1313 if (!dp) { 1314 /* DAD wasn't started yet */ 1315 return; 1316 } 1317 1318 nd6_dad_stoptimer(dp); 1319 nd6_dad_del(dp); 1320 1321 /* Release this function's reference, acquired by nd6_dad_find(). */ 1322 nd6_dad_rele(dp); 1323 } 1324 1325 static void 1326 nd6_dad_timer(struct dadq *dp) 1327 { 1328 CURVNET_SET(dp->dad_vnet); 1329 struct ifaddr *ifa = dp->dad_ifa; 1330 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1331 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1332 char ip6buf[INET6_ADDRSTRLEN]; 1333 struct epoch_tracker et; 1334 1335 KASSERT(ia != NULL, ("DAD entry %p with no address", dp)); 1336 1337 NET_EPOCH_ENTER(et); 1338 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1339 /* Do not need DAD for ifdisabled interface. */ 1340 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1341 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1342 goto err; 1343 } 1344 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1345 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1346 "%s(%s)\n", 1347 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1348 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1349 goto err; 1350 } 1351 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1352 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1353 "%s(%s)\n", 1354 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1355 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1356 goto err; 1357 } 1358 1359 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1360 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1361 (((ifp->if_flags & IFF_UP) == 0) || 1362 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1363 nd6log((LOG_INFO, "%s: could not run DAD " 1364 "because the interface was down or not running.\n", 1365 if_name(ifa->ifa_ifp))); 1366 goto err; 1367 } 1368 1369 /* Need more checks? */ 1370 if (dp->dad_ns_ocount < dp->dad_count) { 1371 /* 1372 * We have more NS to go. Send NS packet for DAD. 1373 */ 1374 nd6_dad_starttimer(dp, 1375 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1); 1376 goto done; 1377 } else { 1378 /* 1379 * We have transmitted sufficient number of DAD packets. 1380 * See what we've got. 1381 */ 1382 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1383 /* We've seen NS or NA, means DAD has failed. */ 1384 nd6_dad_duplicated(ifa, dp); 1385 else if (V_dad_enhanced != 0 && 1386 dp->dad_ns_lcount > 0 && 1387 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1388 /* 1389 * Sec. 4.1 in RFC 7527 requires transmission of 1390 * additional probes until the loopback condition 1391 * becomes clear when a looped back probe is detected. 1392 */ 1393 log(LOG_ERR, "%s: a looped back NS message is " 1394 "detected during DAD for %s. " 1395 "Another DAD probes are being sent.\n", 1396 if_name(ifa->ifa_ifp), 1397 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1398 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1399 /* 1400 * Send an NS immediately and increase dad_count by 1401 * V_nd6_mmaxtries - 1. 1402 */ 1403 dp->dad_count = 1404 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1405 nd6_dad_starttimer(dp, 1406 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1407 1); 1408 goto done; 1409 } else { 1410 /* 1411 * We are done with DAD. No NA came, no NS came. 1412 * No duplicate address found. Check IFDISABLED flag 1413 * again in case that it is changed between the 1414 * beginning of this function and here. 1415 */ 1416 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1417 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1418 1419 nd6log((LOG_DEBUG, 1420 "%s: DAD complete for %s - no duplicates found\n", 1421 if_name(ifa->ifa_ifp), 1422 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1423 if (dp->dad_ns_lcount > 0) 1424 log(LOG_ERR, "%s: DAD completed while " 1425 "a looped back NS message is detected " 1426 "during DAD for %s.\n", 1427 if_name(ifa->ifa_ifp), 1428 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1429 } 1430 } 1431 err: 1432 nd6_dad_del(dp); 1433 done: 1434 NET_EPOCH_EXIT(et); 1435 CURVNET_RESTORE(); 1436 } 1437 1438 static void 1439 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1440 { 1441 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1442 struct ifnet *ifp; 1443 char ip6buf[INET6_ADDRSTRLEN]; 1444 1445 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1446 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1447 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1448 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1449 dp->dad_na_icount); 1450 1451 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1452 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1453 1454 ifp = ifa->ifa_ifp; 1455 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1456 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1457 log(LOG_ERR, "%s: manual intervention required\n", 1458 if_name(ifp)); 1459 1460 /* 1461 * If the address is a link-local address formed from an interface 1462 * identifier based on the hardware address which is supposed to be 1463 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1464 * operation on the interface SHOULD be disabled. 1465 * [RFC 4862, Section 5.4.5] 1466 */ 1467 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1468 struct in6_addr in6; 1469 1470 /* 1471 * To avoid over-reaction, we only apply this logic when we are 1472 * very sure that hardware addresses are supposed to be unique. 1473 */ 1474 switch (ifp->if_type) { 1475 case IFT_ETHER: 1476 case IFT_ATM: 1477 case IFT_IEEE1394: 1478 case IFT_INFINIBAND: 1479 in6 = ia->ia_addr.sin6_addr; 1480 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1481 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1482 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1483 log(LOG_ERR, "%s: possible hardware address " 1484 "duplication detected, disable IPv6\n", 1485 if_name(ifp)); 1486 } 1487 break; 1488 } 1489 } 1490 } 1491 1492 static void 1493 nd6_dad_ns_output(struct dadq *dp) 1494 { 1495 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1496 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1497 int i; 1498 1499 dp->dad_ns_tcount++; 1500 if ((ifp->if_flags & IFF_UP) == 0) { 1501 return; 1502 } 1503 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1504 return; 1505 } 1506 1507 dp->dad_ns_ocount++; 1508 if (V_dad_enhanced != 0) { 1509 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1510 dp->dad_nonce[i] = arc4random(); 1511 /* 1512 * XXXHRS: Note that in the case that 1513 * DupAddrDetectTransmits > 1, multiple NS messages with 1514 * different nonces can be looped back in an unexpected 1515 * order. The current implementation recognizes only 1516 * the latest nonce on the sender side. Practically it 1517 * should work well in almost all cases. 1518 */ 1519 } 1520 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1521 (uint8_t *)&dp->dad_nonce[0]); 1522 } 1523 1524 static void 1525 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1526 { 1527 struct dadq *dp; 1528 1529 if (ifa == NULL) 1530 panic("ifa == NULL in nd6_dad_ns_input"); 1531 1532 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1533 if (V_dad_enhanced == 0) 1534 ndopt_nonce = NULL; 1535 dp = nd6_dad_find(ifa, ndopt_nonce); 1536 if (dp == NULL) 1537 return; 1538 1539 dp->dad_ns_icount++; 1540 nd6_dad_rele(dp); 1541 } 1542 1543 static void 1544 nd6_dad_na_input(struct ifaddr *ifa) 1545 { 1546 struct dadq *dp; 1547 1548 if (ifa == NULL) 1549 panic("ifa == NULL in nd6_dad_na_input"); 1550 1551 dp = nd6_dad_find(ifa, NULL); 1552 if (dp != NULL) { 1553 dp->dad_na_icount++; 1554 nd6_dad_rele(dp); 1555 } 1556 } 1557