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/if_private.h> 65 #include <net/route.h> 66 #include <net/vnet.h> 67 68 #include <netinet/in.h> 69 #include <netinet/in_var.h> 70 #include <net/if_llatbl.h> 71 #include <netinet6/in6_var.h> 72 #include <netinet6/in6_ifattach.h> 73 #include <netinet/ip6.h> 74 #include <netinet6/ip6_var.h> 75 #include <netinet6/scope6_var.h> 76 #include <netinet6/nd6.h> 77 #include <netinet/icmp6.h> 78 #include <netinet/ip_carp.h> 79 #include <netinet6/send.h> 80 81 #define SDL(s) ((struct sockaddr_dl *)s) 82 83 struct dadq; 84 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *); 85 static void nd6_dad_add(struct dadq *dp); 86 static void nd6_dad_del(struct dadq *dp); 87 static void nd6_dad_rele(struct dadq *); 88 static void nd6_dad_starttimer(struct dadq *, int); 89 static void nd6_dad_stoptimer(struct dadq *); 90 static void nd6_dad_timer(void *); 91 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *); 92 static void nd6_dad_ns_output(struct dadq *); 93 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *); 94 static void nd6_dad_na_input(struct ifaddr *); 95 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 96 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 97 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *, 98 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int); 99 100 static struct ifaddr *nd6_proxy_fill_sdl(struct ifnet *, 101 const struct in6_addr *, struct sockaddr_dl *); 102 103 VNET_DEFINE_STATIC(int, dad_enhanced) = 1; 104 #define V_dad_enhanced VNET(dad_enhanced) 105 106 SYSCTL_DECL(_net_inet6_ip6); 107 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW, 108 &VNET_NAME(dad_enhanced), 0, 109 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD."); 110 111 VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to 112 transmit DAD packet */ 113 #define V_dad_maxtry VNET(dad_maxtry) 114 115 /* 116 * Input a Neighbor Solicitation Message. 117 * 118 * Based on RFC 2461 119 * Based on RFC 2462 (duplicate address detection) 120 */ 121 void 122 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 123 { 124 struct ifnet *ifp; 125 struct ip6_hdr *ip6; 126 struct nd_neighbor_solicit *nd_ns; 127 struct in6_addr daddr6, myaddr6, saddr6, taddr6; 128 struct ifaddr *ifa; 129 struct sockaddr_dl proxydl; 130 union nd_opts ndopts; 131 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 132 char *lladdr; 133 int anycast, lladdrlen, proxy, rflag, tentative, tlladdr; 134 135 ifa = NULL; 136 137 /* RFC 6980: Nodes MUST silently ignore fragments */ 138 if(m->m_flags & M_FRAGMENTED) 139 goto freeit; 140 141 ifp = m->m_pkthdr.rcvif; 142 ip6 = mtod(m, struct ip6_hdr *); 143 if (__predict_false(ip6->ip6_hlim != 255)) { 144 ICMP6STAT_INC(icp6s_invlhlim); 145 nd6log((LOG_ERR, 146 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 147 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 148 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 149 goto bads; 150 } 151 152 if (m->m_len < off + icmp6len) { 153 m = m_pullup(m, off + icmp6len); 154 if (m == NULL) { 155 IP6STAT_INC(ip6s_exthdrtoolong); 156 return; 157 } 158 } 159 ip6 = mtod(m, struct ip6_hdr *); 160 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 161 162 saddr6 = ip6->ip6_src; 163 daddr6 = ip6->ip6_dst; 164 taddr6 = nd_ns->nd_ns_target; 165 if (in6_setscope(&taddr6, ifp, NULL) != 0) 166 goto bad; 167 168 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 169 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 170 rflag = 0; 171 172 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 173 /* dst has to be a solicited node multicast address. */ 174 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 175 /* don't check ifindex portion */ 176 daddr6.s6_addr32[1] == 0 && 177 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 178 daddr6.s6_addr8[12] == 0xff) { 179 ; /* good */ 180 } else { 181 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 182 "(wrong ip6 dst)\n")); 183 goto bad; 184 } 185 } else if (!V_nd6_onlink_ns_rfc4861) { 186 struct sockaddr_in6 src_sa6; 187 188 /* 189 * According to recent IETF discussions, it is not a good idea 190 * to accept a NS from an address which would not be deemed 191 * to be a neighbor otherwise. This point is expected to be 192 * clarified in future revisions of the specification. 193 */ 194 bzero(&src_sa6, sizeof(src_sa6)); 195 src_sa6.sin6_family = AF_INET6; 196 src_sa6.sin6_len = sizeof(src_sa6); 197 src_sa6.sin6_addr = saddr6; 198 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 199 nd6log((LOG_INFO, "nd6_ns_input: " 200 "NS packet from non-neighbor\n")); 201 goto bad; 202 } 203 } 204 205 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 206 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 207 goto bad; 208 } 209 210 icmp6len -= sizeof(*nd_ns); 211 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 212 if (nd6_options(&ndopts) < 0) { 213 nd6log((LOG_INFO, 214 "nd6_ns_input: invalid ND option, ignored\n")); 215 /* nd6_options have incremented stats */ 216 goto freeit; 217 } 218 219 lladdr = NULL; 220 lladdrlen = 0; 221 if (ndopts.nd_opts_src_lladdr) { 222 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 223 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 224 } 225 226 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 227 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 228 "(link-layer address option)\n")); 229 goto bad; 230 } 231 232 /* 233 * Attaching target link-layer address to the NA? 234 * (RFC 2461 7.2.4) 235 * 236 * NS IP dst is unicast/anycast MUST NOT add 237 * NS IP dst is solicited-node multicast MUST add 238 * 239 * In implementation, we add target link-layer address by default. 240 * We do not add one in MUST NOT cases. 241 */ 242 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 243 tlladdr = 0; 244 else 245 tlladdr = 1; 246 247 /* 248 * Target address (taddr6) must be either: 249 * (1) Valid unicast/anycast address for my receiving interface, 250 * (2) Unicast address for which I'm offering proxy service, or 251 * (3) "tentative" address on which DAD is being performed. 252 */ 253 /* (1) and (3) check. */ 254 if (ifp->if_carp) 255 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 256 else 257 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 258 259 /* (2) check. */ 260 proxy = 0; 261 if (ifa == NULL) { 262 if ((ifa = nd6_proxy_fill_sdl(ifp, &taddr6, &proxydl)) != NULL) 263 proxy = 1; 264 } 265 if (ifa == NULL) { 266 /* 267 * We've got an NS packet, and we don't have that adddress 268 * assigned for us. We MUST silently ignore it. 269 * See RFC2461 7.2.3. 270 */ 271 goto freeit; 272 } 273 myaddr6 = *IFA_IN6(ifa); 274 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 275 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 276 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 277 goto freeit; 278 279 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 280 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 281 "(if %d, NS packet %d)\n", 282 ip6_sprintf(ip6bufs, &taddr6), 283 ifp->if_addrlen, lladdrlen - 2)); 284 goto bad; 285 } 286 287 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 288 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 289 ip6_sprintf(ip6bufs, &saddr6))); 290 goto freeit; 291 } 292 293 /* 294 * We have neighbor solicitation packet, with target address equals to 295 * one of my tentative address. 296 * 297 * src addr how to process? 298 * --- --- 299 * multicast of course, invalid (rejected in ip6_input) 300 * unicast somebody is doing address resolution -> ignore 301 * unspec dup address detection 302 * 303 * The processing is defined in RFC 2462. 304 */ 305 if (tentative) { 306 /* 307 * If source address is unspecified address, it is for 308 * duplicate address detection. 309 * 310 * If not, the packet is for addess resolution; 311 * silently ignore it. 312 */ 313 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 314 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 315 316 goto freeit; 317 } 318 319 /* 320 * If the source address is unspecified address, entries must not 321 * be created or updated. 322 * It looks that sender is performing DAD. Output NA toward 323 * all-node multicast address, to tell the sender that I'm using 324 * the address. 325 * S bit ("solicited") must be zero. 326 */ 327 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 328 struct in6_addr in6_all; 329 330 in6_all = in6addr_linklocal_allnodes; 331 if (in6_setscope(&in6_all, ifp, NULL) != 0) 332 goto bad; 333 nd6_na_output_fib(ifp, &in6_all, &taddr6, 334 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 335 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 336 M_GETFIB(m)); 337 goto freeit; 338 } 339 340 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 341 ND_NEIGHBOR_SOLICIT, 0); 342 343 nd6_na_output_fib(ifp, &saddr6, &taddr6, 344 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 345 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 346 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 347 freeit: 348 if (ifa != NULL) 349 ifa_free(ifa); 350 m_freem(m); 351 return; 352 353 bad: 354 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 355 ip6_sprintf(ip6bufs, &saddr6))); 356 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 357 ip6_sprintf(ip6bufs, &daddr6))); 358 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 359 ip6_sprintf(ip6bufs, &taddr6))); 360 bads: 361 ICMP6STAT_INC(icp6s_badns); 362 if (ifa != NULL) 363 ifa_free(ifa); 364 m_freem(m); 365 } 366 367 static struct ifaddr * 368 nd6_proxy_fill_sdl(struct ifnet *ifp, const struct in6_addr *taddr6, 369 struct sockaddr_dl *sdl) 370 { 371 struct ifaddr *ifa; 372 struct llentry *ln; 373 374 ifa = NULL; 375 ln = nd6_lookup(taddr6, LLE_SF(AF_INET6, 0), ifp); 376 if (ln == NULL) 377 return (ifa); 378 if ((ln->la_flags & (LLE_PUB | LLE_VALID)) == (LLE_PUB | LLE_VALID)) { 379 link_init_sdl(ifp, (struct sockaddr *)sdl, ifp->if_type); 380 sdl->sdl_alen = ifp->if_addrlen; 381 bcopy(ln->ll_addr, &sdl->sdl_data, ifp->if_addrlen); 382 LLE_RUNLOCK(ln); 383 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 384 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 385 } else 386 LLE_RUNLOCK(ln); 387 388 return (ifa); 389 } 390 391 /* 392 * Output a Neighbor Solicitation Message. Caller specifies: 393 * - ICMP6 header source IP6 address 394 * - ND6 header target IP6 address 395 * - ND6 header source datalink address 396 * 397 * Based on RFC 2461 398 * Based on RFC 2462 (duplicate address detection) 399 * 400 * ln - for source address determination 401 * nonce - If non-NULL, NS is used for duplicate address detection and 402 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 403 */ 404 static void 405 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 406 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 407 uint8_t *nonce, u_int fibnum) 408 { 409 struct mbuf *m; 410 struct m_tag *mtag; 411 struct ip6_hdr *ip6; 412 struct nd_neighbor_solicit *nd_ns; 413 struct ip6_moptions im6o; 414 int icmp6len; 415 int maxlen; 416 417 NET_EPOCH_ASSERT(); 418 419 if (IN6_IS_ADDR_MULTICAST(taddr6)) 420 return; 421 422 /* estimate the size of message */ 423 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 424 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 425 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 426 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 427 __func__, max_linkhdr, maxlen, MCLBYTES)); 428 429 if (max_linkhdr + maxlen > MHLEN) 430 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 431 else 432 m = m_gethdr(M_NOWAIT, MT_DATA); 433 if (m == NULL) 434 return; 435 M_SETFIB(m, fibnum); 436 437 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 438 m->m_flags |= M_MCAST; 439 im6o.im6o_multicast_ifp = ifp; 440 im6o.im6o_multicast_hlim = 255; 441 im6o.im6o_multicast_loop = 0; 442 } 443 444 icmp6len = sizeof(*nd_ns); 445 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 446 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 447 448 /* fill neighbor solicitation packet */ 449 ip6 = mtod(m, struct ip6_hdr *); 450 ip6->ip6_flow = 0; 451 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 452 ip6->ip6_vfc |= IPV6_VERSION; 453 /* ip6->ip6_plen will be set later */ 454 ip6->ip6_nxt = IPPROTO_ICMPV6; 455 ip6->ip6_hlim = 255; 456 if (daddr6) 457 ip6->ip6_dst = *daddr6; 458 else { 459 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 460 ip6->ip6_dst.s6_addr16[1] = 0; 461 ip6->ip6_dst.s6_addr32[1] = 0; 462 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 463 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 464 ip6->ip6_dst.s6_addr8[12] = 0xff; 465 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 466 goto bad; 467 } 468 if (nonce == NULL) { 469 char ip6buf[INET6_ADDRSTRLEN]; 470 struct ifaddr *ifa = NULL; 471 472 /* 473 * RFC2461 7.2.2: 474 * "If the source address of the packet prompting the 475 * solicitation is the same as one of the addresses assigned 476 * to the outgoing interface, that address SHOULD be placed 477 * in the IP Source Address of the outgoing solicitation. 478 * Otherwise, any one of the addresses assigned to the 479 * interface should be used." 480 * 481 * We use the source address for the prompting packet 482 * (saddr6), if saddr6 belongs to the outgoing interface. 483 * Otherwise, we perform the source address selection as usual. 484 */ 485 if (saddr6 != NULL) 486 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 487 if (ifa == NULL) { 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 nd6log((LOG_DEBUG, "%s: source can't be " 497 "determined: dst=%s, error=%d\n", __func__, 498 ip6_sprintf(ip6buf, &dst6), 499 error)); 500 goto bad; 501 } 502 ip6->ip6_src = src6; 503 } else 504 ip6->ip6_src = *saddr6; 505 506 if (ifp->if_carp != NULL) { 507 /* 508 * Check that selected source address belongs to 509 * CARP addresses. 510 */ 511 if (ifa == NULL) 512 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, 513 &ip6->ip6_src); 514 /* 515 * Do not send NS for CARP address if we are not 516 * the CARP master. 517 */ 518 if (ifa != NULL && ifa->ifa_carp != NULL && 519 !(*carp_master_p)(ifa)) { 520 log(LOG_DEBUG, 521 "nd6_ns_output: NS from BACKUP CARP address %s\n", 522 ip6_sprintf(ip6buf, &ip6->ip6_src)); 523 ifa_free(ifa); 524 goto bad; 525 } 526 } 527 if (ifa != NULL) 528 ifa_free(ifa); 529 } else { 530 /* 531 * Source address for DAD packet must always be IPv6 532 * unspecified address. (0::0) 533 * We actually don't have to 0-clear the address (we did it 534 * above), but we do so here explicitly to make the intention 535 * clearer. 536 */ 537 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 538 } 539 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 540 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 541 nd_ns->nd_ns_code = 0; 542 nd_ns->nd_ns_reserved = 0; 543 nd_ns->nd_ns_target = *taddr6; 544 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 545 546 /* 547 * Add source link-layer address option. 548 * 549 * spec implementation 550 * --- --- 551 * DAD packet MUST NOT do not add the option 552 * there's no link layer address: 553 * impossible do not add the option 554 * there's link layer address: 555 * Multicast NS MUST add one add the option 556 * Unicast NS SHOULD add one add the option 557 */ 558 if (nonce == NULL) { 559 struct nd_opt_hdr *nd_opt; 560 char *mac; 561 int optlen; 562 563 mac = NULL; 564 if (ifp->if_carp) 565 mac = (*carp_macmatch6_p)(ifp, m, &ip6->ip6_src); 566 if (mac == NULL) 567 mac = nd6_ifptomac(ifp); 568 569 if (mac != NULL) { 570 nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 571 optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 572 /* 8 byte alignments... */ 573 optlen = (optlen + 7) & ~7; 574 m->m_pkthdr.len += optlen; 575 m->m_len += optlen; 576 icmp6len += optlen; 577 bzero(nd_opt, optlen); 578 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 579 nd_opt->nd_opt_len = optlen >> 3; 580 bcopy(mac, nd_opt + 1, ifp->if_addrlen); 581 } 582 } 583 /* 584 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 585 * This behavior is documented as Enhanced Duplicate Address 586 * Detection in RFC 7527. 587 * net.inet6.ip6.dad_enhanced=0 disables this. 588 */ 589 if (V_dad_enhanced != 0 && nonce != NULL) { 590 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 591 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 592 /* 8-byte alignment is required. */ 593 optlen = (optlen + 7) & ~7; 594 595 m->m_pkthdr.len += optlen; 596 m->m_len += optlen; 597 icmp6len += optlen; 598 bzero((caddr_t)nd_opt, optlen); 599 nd_opt->nd_opt_type = ND_OPT_NONCE; 600 nd_opt->nd_opt_len = optlen >> 3; 601 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 602 } 603 ip6->ip6_plen = htons((u_short)icmp6len); 604 nd_ns->nd_ns_cksum = 0; 605 nd_ns->nd_ns_cksum = 606 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 607 608 if (send_sendso_input_hook != NULL) { 609 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 610 sizeof(unsigned short), M_NOWAIT); 611 if (mtag == NULL) 612 goto bad; 613 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 614 m_tag_prepend(m, mtag); 615 } 616 617 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 618 &im6o, NULL, NULL); 619 icmp6_ifstat_inc(ifp, ifs6_out_msg); 620 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 621 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 622 623 return; 624 625 bad: 626 m_freem(m); 627 } 628 629 #ifndef BURN_BRIDGES 630 void 631 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 632 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 633 { 634 635 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 636 } 637 #endif 638 /* 639 * Neighbor advertisement input handling. 640 * 641 * Based on RFC 2461 642 * Based on RFC 2462 (duplicate address detection) 643 * 644 * the following items are not implemented yet: 645 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 646 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 647 */ 648 void 649 nd6_na_input(struct mbuf *m, int off, int icmp6len) 650 { 651 struct ifnet *ifp; 652 struct ip6_hdr *ip6; 653 struct ifaddr *ifa; 654 struct llentry *ln; 655 struct mbuf *chain; 656 struct nd_neighbor_advert *nd_na; 657 struct in6_addr daddr6, taddr6; 658 union nd_opts ndopts; 659 u_char linkhdr[LLE_MAX_LINKHDR]; 660 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 661 char *lladdr; 662 size_t linkhdrsize; 663 int flags, is_override, is_router, is_solicited; 664 int lladdr_off, lladdrlen, checklink; 665 bool flush_holdchain = false; 666 667 NET_EPOCH_ASSERT(); 668 669 chain = NULL; 670 ln = NULL; 671 checklink = 0; 672 673 /* RFC 6980: Nodes MUST silently ignore fragments */ 674 if(m->m_flags & M_FRAGMENTED) 675 goto freeit; 676 677 ifp = m->m_pkthdr.rcvif; 678 ip6 = mtod(m, struct ip6_hdr *); 679 if (__predict_false(ip6->ip6_hlim != 255)) { 680 ICMP6STAT_INC(icp6s_invlhlim); 681 nd6log((LOG_ERR, 682 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 683 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 684 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 685 goto bad; 686 } 687 688 if (m->m_len < off + icmp6len) { 689 m = m_pullup(m, off + icmp6len); 690 if (m == NULL) { 691 IP6STAT_INC(ip6s_exthdrtoolong); 692 return; 693 } 694 } 695 ip6 = mtod(m, struct ip6_hdr *); 696 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 697 698 flags = nd_na->nd_na_flags_reserved; 699 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 700 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 701 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 702 703 taddr6 = nd_na->nd_na_target; 704 if (in6_setscope(&taddr6, ifp, NULL)) 705 goto bad; /* XXX: impossible */ 706 707 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 708 nd6log((LOG_ERR, 709 "nd6_na_input: invalid target address %s\n", 710 ip6_sprintf(ip6bufs, &taddr6))); 711 goto bad; 712 } 713 714 daddr6 = ip6->ip6_dst; 715 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 716 if (is_solicited) { 717 nd6log((LOG_ERR, 718 "nd6_na_input: a solicited adv is multicasted\n")); 719 goto bad; 720 } 721 722 icmp6len -= sizeof(*nd_na); 723 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 724 if (nd6_options(&ndopts) < 0) { 725 nd6log((LOG_INFO, 726 "nd6_na_input: invalid ND option, ignored\n")); 727 /* nd6_options have incremented stats */ 728 goto freeit; 729 } 730 731 lladdr = NULL; 732 lladdrlen = 0; 733 if (ndopts.nd_opts_tgt_lladdr) { 734 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 735 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 736 } 737 738 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 739 if (ifa != NULL && ifa->ifa_carp != NULL) { 740 /* 741 * Silently ignore NAs for CARP addresses if we are not 742 * the CARP master. 743 */ 744 if (!(*carp_master_p)(ifa)) { 745 log(LOG_DEBUG, 746 "nd6_na_input: NA for BACKUP CARP address %s\n", 747 ip6_sprintf(ip6bufs, &taddr6)); 748 ifa_free(ifa); 749 goto freeit; 750 } 751 } 752 /* 753 * Target address matches one of my interface address. 754 * 755 * If my address is tentative, this means that there's somebody 756 * already using the same address as mine. This indicates DAD failure. 757 * This is defined in RFC 2462. 758 * 759 * Otherwise, process as defined in RFC 2461. 760 */ 761 if (ifa 762 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 763 nd6_dad_na_input(ifa); 764 ifa_free(ifa); 765 goto freeit; 766 } 767 768 /* Just for safety, maybe unnecessary. */ 769 if (ifa) { 770 ifa_free(ifa); 771 log(LOG_ERR, 772 "nd6_na_input: duplicate IP6 address %s\n", 773 ip6_sprintf(ip6bufs, &taddr6)); 774 goto freeit; 775 } 776 777 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 778 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 779 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 780 ifp->if_addrlen, lladdrlen - 2)); 781 goto bad; 782 } 783 784 /* 785 * If no neighbor cache entry is found, NA SHOULD silently be 786 * discarded. 787 */ 788 ln = nd6_lookup(&taddr6, LLE_SF(AF_INET6, LLE_EXCLUSIVE), ifp); 789 if (ln == NULL) { 790 goto freeit; 791 } 792 793 /* 794 * Do not try to override static entry. 795 */ 796 if (ln->la_flags & LLE_STATIC) 797 goto freeit; 798 799 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 800 /* 801 * If the link-layer has address, and no lladdr option came, 802 * discard the packet. 803 */ 804 if (ifp->if_addrlen && lladdr == NULL) { 805 goto freeit; 806 } 807 808 /* 809 * Record link-layer address, and update the state. 810 */ 811 if (!nd6_try_set_entry_addr(ifp, ln, lladdr)) 812 goto freeit; 813 814 flush_holdchain = true; 815 if (is_solicited) 816 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 817 else 818 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 819 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 820 if ((ln->ln_router = is_router) != 0) { 821 /* 822 * This means a router's state has changed from 823 * non-reachable to probably reachable, and might 824 * affect the status of associated prefixes.. 825 */ 826 checklink = 1; 827 } 828 } else { 829 int llchange; 830 831 /* 832 * Check if the link-layer address has changed or not. 833 */ 834 if (lladdr == NULL) 835 llchange = 0; 836 else { 837 if (ln->la_flags & LLE_VALID) { 838 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 839 llchange = 1; 840 else 841 llchange = 0; 842 } else 843 llchange = 1; 844 } 845 846 /* 847 * This is VERY complex. Look at it with care. 848 * 849 * override solicit lladdr llchange action 850 * (L: record lladdr) 851 * 852 * 0 0 n -- (2c) 853 * 0 0 y n (2b) L 854 * 0 0 y y (1) REACHABLE->STALE 855 * 0 1 n -- (2c) *->REACHABLE 856 * 0 1 y n (2b) L *->REACHABLE 857 * 0 1 y y (1) REACHABLE->STALE 858 * 1 0 n -- (2a) 859 * 1 0 y n (2a) L 860 * 1 0 y y (2a) L *->STALE 861 * 1 1 n -- (2a) *->REACHABLE 862 * 1 1 y n (2a) L *->REACHABLE 863 * 1 1 y y (2a) L *->REACHABLE 864 */ 865 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 866 /* 867 * If state is REACHABLE, make it STALE. 868 * no other updates should be done. 869 */ 870 if (ln->ln_state == ND6_LLINFO_REACHABLE) 871 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 872 goto freeit; 873 } else if (is_override /* (2a) */ 874 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 875 || lladdr == NULL) { /* (2c) */ 876 /* 877 * Update link-local address, if any. 878 */ 879 if (lladdr != NULL) { 880 linkhdrsize = sizeof(linkhdr); 881 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 882 linkhdr, &linkhdrsize, &lladdr_off) != 0) 883 goto freeit; 884 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 885 linkhdrsize, lladdr_off) == 0) 886 goto freeit; 887 EVENTHANDLER_INVOKE(lle_event, ln, 888 LLENTRY_RESOLVED); 889 } 890 891 /* 892 * If solicited, make the state REACHABLE. 893 * If not solicited and the link-layer address was 894 * changed, make it STALE. 895 */ 896 if (is_solicited) 897 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 898 else { 899 if (lladdr != NULL && llchange) 900 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 901 } 902 } 903 904 if (ln->ln_router && !is_router) { 905 /* 906 * The peer dropped the router flag. 907 * Remove the sender from the Default Router List and 908 * update the Destination Cache entries. 909 */ 910 struct ifnet *nd6_ifp; 911 912 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 913 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 914 (ND_IFINFO(nd6_ifp)->flags & 915 ND6_IFF_ACCEPT_RTADV) != 0) 916 /* 917 * Even if the neighbor is not in the default 918 * router list, the neighbor may be used as a 919 * next hop for some destinations (e.g. redirect 920 * case). So we must call rt6_flush explicitly. 921 */ 922 rt6_flush(&ip6->ip6_src, ifp); 923 } 924 ln->ln_router = is_router; 925 } 926 /* XXX - QL 927 * Does this matter? 928 * rt->rt_flags &= ~RTF_REJECT; 929 */ 930 ln->la_asked = 0; 931 if (ln->la_hold != NULL) 932 chain = nd6_grab_holdchain(ln); 933 freeit: 934 if (ln != NULL) 935 LLE_WUNLOCK(ln); 936 937 if (chain != NULL) 938 nd6_flush_holdchain(ifp, ln, chain); 939 if (flush_holdchain) 940 nd6_flush_children_holdchain(ifp, ln); 941 942 if (checklink) 943 pfxlist_onlink_check(); 944 945 m_freem(m); 946 return; 947 948 bad: 949 if (ln != NULL) 950 LLE_WUNLOCK(ln); 951 952 ICMP6STAT_INC(icp6s_badna); 953 m_freem(m); 954 } 955 956 /* 957 * Neighbor advertisement output handling. 958 * 959 * Based on RFC 2461 960 * 961 * the following items are not implemented yet: 962 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 963 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 964 * 965 * tlladdr - 1 if include target link-layer address 966 * sdl0 - sockaddr_dl (= proxy NA) or NULL 967 */ 968 static void 969 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 970 const struct in6_addr *taddr6, u_long flags, int tlladdr, 971 struct sockaddr *sdl0, u_int fibnum) 972 { 973 struct mbuf *m; 974 struct m_tag *mtag; 975 struct ip6_hdr *ip6; 976 struct nd_neighbor_advert *nd_na; 977 struct ip6_moptions im6o; 978 struct in6_addr daddr6, dst6, src6; 979 uint32_t scopeid; 980 981 NET_EPOCH_ASSERT(); 982 983 int icmp6len, maxlen, error; 984 caddr_t mac = NULL; 985 986 daddr6 = *daddr6_0; /* make a local copy for modification */ 987 988 /* estimate the size of message */ 989 maxlen = sizeof(*ip6) + sizeof(*nd_na); 990 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 991 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 992 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 993 __func__, max_linkhdr, maxlen, MCLBYTES)); 994 995 if (max_linkhdr + maxlen > MHLEN) 996 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 997 else 998 m = m_gethdr(M_NOWAIT, MT_DATA); 999 if (m == NULL) 1000 return; 1001 M_SETFIB(m, fibnum); 1002 1003 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 1004 m->m_flags |= M_MCAST; 1005 im6o.im6o_multicast_ifp = ifp; 1006 im6o.im6o_multicast_hlim = 255; 1007 im6o.im6o_multicast_loop = 0; 1008 } 1009 1010 icmp6len = sizeof(*nd_na); 1011 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 1012 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 1013 1014 /* fill neighbor advertisement packet */ 1015 ip6 = mtod(m, struct ip6_hdr *); 1016 ip6->ip6_flow = 0; 1017 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 1018 ip6->ip6_vfc |= IPV6_VERSION; 1019 ip6->ip6_nxt = IPPROTO_ICMPV6; 1020 ip6->ip6_hlim = 255; 1021 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 1022 /* reply to DAD */ 1023 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 1024 daddr6.s6_addr16[1] = 0; 1025 daddr6.s6_addr32[1] = 0; 1026 daddr6.s6_addr32[2] = 0; 1027 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 1028 if (in6_setscope(&daddr6, ifp, NULL)) 1029 goto bad; 1030 1031 flags &= ~ND_NA_FLAG_SOLICITED; 1032 } 1033 ip6->ip6_dst = daddr6; 1034 1035 /* 1036 * Select a source whose scope is the same as that of the dest. 1037 */ 1038 in6_splitscope(&daddr6, &dst6, &scopeid); 1039 error = in6_selectsrc_addr(fibnum, &dst6, 1040 scopeid, ifp, &src6, NULL); 1041 if (error) { 1042 char ip6buf[INET6_ADDRSTRLEN]; 1043 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1044 "determined: dst=%s, error=%d\n", 1045 ip6_sprintf(ip6buf, &daddr6), error)); 1046 goto bad; 1047 } 1048 ip6->ip6_src = src6; 1049 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1050 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1051 nd_na->nd_na_code = 0; 1052 nd_na->nd_na_target = *taddr6; 1053 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1054 1055 /* 1056 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1057 * see nd6_ns_input() for details. 1058 * Basically, if NS packet is sent to unicast/anycast addr, 1059 * target lladdr option SHOULD NOT be included. 1060 */ 1061 if (tlladdr) { 1062 /* 1063 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1064 * lladdr in sdl0. If we are not proxying (sending NA for 1065 * my address) use lladdr configured for the interface. 1066 */ 1067 if (sdl0 == NULL) { 1068 if (ifp->if_carp) 1069 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1070 if (mac == NULL) 1071 mac = nd6_ifptomac(ifp); 1072 } else if (sdl0->sa_family == AF_LINK) { 1073 struct sockaddr_dl *sdl; 1074 sdl = (struct sockaddr_dl *)sdl0; 1075 if (sdl->sdl_alen == ifp->if_addrlen) 1076 mac = LLADDR(sdl); 1077 } 1078 } 1079 if (tlladdr && mac) { 1080 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1081 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1082 1083 /* roundup to 8 bytes alignment! */ 1084 optlen = (optlen + 7) & ~7; 1085 1086 m->m_pkthdr.len += optlen; 1087 m->m_len += optlen; 1088 icmp6len += optlen; 1089 bzero((caddr_t)nd_opt, optlen); 1090 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1091 nd_opt->nd_opt_len = optlen >> 3; 1092 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1093 } else 1094 flags &= ~ND_NA_FLAG_OVERRIDE; 1095 1096 ip6->ip6_plen = htons((u_short)icmp6len); 1097 nd_na->nd_na_flags_reserved = flags; 1098 nd_na->nd_na_cksum = 0; 1099 nd_na->nd_na_cksum = 1100 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1101 1102 if (send_sendso_input_hook != NULL) { 1103 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1104 sizeof(unsigned short), M_NOWAIT); 1105 if (mtag == NULL) 1106 goto bad; 1107 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1108 m_tag_prepend(m, mtag); 1109 } 1110 1111 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1112 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1113 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1114 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1115 1116 return; 1117 1118 bad: 1119 m_freem(m); 1120 } 1121 1122 #ifndef BURN_BRIDGES 1123 void 1124 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1125 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1126 struct sockaddr *sdl0) 1127 { 1128 1129 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1130 RT_DEFAULT_FIB); 1131 } 1132 #endif 1133 1134 caddr_t 1135 nd6_ifptomac(struct ifnet *ifp) 1136 { 1137 switch (ifp->if_type) { 1138 case IFT_ETHER: 1139 case IFT_IEEE1394: 1140 case IFT_L2VLAN: 1141 case IFT_INFINIBAND: 1142 case IFT_BRIDGE: 1143 return IF_LLADDR(ifp); 1144 default: 1145 return NULL; 1146 } 1147 } 1148 1149 struct dadq { 1150 TAILQ_ENTRY(dadq) dad_list; 1151 struct ifaddr *dad_ifa; 1152 int dad_count; /* max NS to send */ 1153 int dad_ns_tcount; /* # of trials to send NS */ 1154 int dad_ns_ocount; /* NS sent so far */ 1155 int dad_ns_icount; 1156 int dad_na_icount; 1157 int dad_ns_lcount; /* looped back NS */ 1158 int dad_loopbackprobe; /* probing state for loopback detection */ 1159 struct callout dad_timer_ch; 1160 struct vnet *dad_vnet; 1161 u_int dad_refcnt; 1162 #define ND_OPT_NONCE_LEN32 \ 1163 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1164 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1165 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */ 1166 }; 1167 1168 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq); 1169 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock); 1170 #define V_dadq VNET(dadq) 1171 #define V_dad_rwlock VNET(dad_rwlock) 1172 1173 #define DADQ_LOCKPTR() (&V_dad_rwlock) 1174 #define DADQ_LOCK_INIT() rw_init(DADQ_LOCKPTR(), "nd6 DAD queue") 1175 #define DADQ_RLOCK() rw_rlock(DADQ_LOCKPTR()) 1176 #define DADQ_RUNLOCK() rw_runlock(DADQ_LOCKPTR()) 1177 #define DADQ_WLOCK() rw_wlock(DADQ_LOCKPTR()) 1178 #define DADQ_WUNLOCK() rw_wunlock(DADQ_LOCKPTR()) 1179 1180 #define DADQ_LOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_LOCKED); 1181 #define DADQ_RLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_RLOCKED); 1182 #define DADQ_WLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_WLOCKED); 1183 1184 static void 1185 nd6_dad_add(struct dadq *dp) 1186 { 1187 DADQ_WLOCK_ASSERT(); 1188 1189 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1190 dp->dad_ondadq = true; 1191 } 1192 1193 static void 1194 nd6_dad_del(struct dadq *dp) 1195 { 1196 DADQ_WLOCK_ASSERT(); 1197 1198 if (dp->dad_ondadq) { 1199 /* 1200 * Remove dp from the dadq and release the dadq's 1201 * reference. 1202 */ 1203 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1204 dp->dad_ondadq = false; 1205 nd6_dad_rele(dp); 1206 } 1207 } 1208 1209 static struct dadq * 1210 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1211 { 1212 struct dadq *dp; 1213 1214 DADQ_LOCK_ASSERT(); 1215 1216 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1217 if (dp->dad_ifa != ifa) 1218 continue; 1219 1220 /* 1221 * Skip if the nonce matches the received one. 1222 * +2 in the length is required because of type and 1223 * length fields are included in a header. 1224 */ 1225 if (n != NULL && 1226 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1227 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1228 ND_OPT_NONCE_LEN) == 0) { 1229 dp->dad_ns_lcount++; 1230 continue; 1231 } 1232 break; 1233 } 1234 1235 return (dp); 1236 } 1237 1238 static void 1239 nd6_dad_starttimer(struct dadq *dp, int ticks) 1240 { 1241 DADQ_WLOCK_ASSERT(); 1242 1243 callout_reset(&dp->dad_timer_ch, ticks, nd6_dad_timer, dp); 1244 } 1245 1246 static void 1247 nd6_dad_stoptimer(struct dadq *dp) 1248 { 1249 callout_drain(&dp->dad_timer_ch); 1250 } 1251 1252 static void 1253 nd6_dad_rele(struct dadq *dp) 1254 { 1255 if (refcount_release(&dp->dad_refcnt)) { 1256 KASSERT(!dp->dad_ondadq, ("dp %p still on DAD queue", dp)); 1257 ifa_free(dp->dad_ifa); 1258 free(dp, M_IP6NDP); 1259 } 1260 } 1261 1262 void 1263 nd6_dad_init(void) 1264 { 1265 DADQ_LOCK_INIT(); 1266 TAILQ_INIT(&V_dadq); 1267 } 1268 1269 /* 1270 * Start Duplicate Address Detection (DAD) for specified interface address. 1271 */ 1272 void 1273 nd6_dad_start(struct ifaddr *ifa, int delay) 1274 { 1275 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1276 struct dadq *dp; 1277 char ip6buf[INET6_ADDRSTRLEN]; 1278 1279 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0, 1280 ("starting DAD on non-tentative address %p", ifa)); 1281 1282 /* 1283 * If we don't need DAD, don't do it. 1284 * There are several cases: 1285 * - DAD is disabled globally or on the interface 1286 * - the interface address is anycast 1287 */ 1288 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 || 1289 V_ip6_dad_count == 0 || 1290 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) != 0) { 1291 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1292 return; 1293 } 1294 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 || 1295 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || 1296 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) != 0) 1297 return; 1298 1299 DADQ_WLOCK(); 1300 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1301 /* 1302 * DAD is already in progress. Let the existing entry 1303 * finish it. 1304 */ 1305 DADQ_WUNLOCK(); 1306 return; 1307 } 1308 1309 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1310 if (dp == NULL) { 1311 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1312 "%s(%s)\n", 1313 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1314 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1315 return; 1316 } 1317 callout_init_rw(&dp->dad_timer_ch, DADQ_LOCKPTR(), 1318 CALLOUT_RETURNUNLOCKED); 1319 #ifdef VIMAGE 1320 dp->dad_vnet = curvnet; 1321 #endif 1322 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1323 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1324 1325 /* 1326 * Send NS packet for DAD, ip6_dad_count times. 1327 * Note that we must delay the first transmission, if this is the 1328 * first packet to be sent from the interface after interface 1329 * (re)initialization. 1330 */ 1331 dp->dad_ifa = ifa; 1332 ifa_ref(dp->dad_ifa); 1333 dp->dad_count = V_ip6_dad_count; 1334 dp->dad_ns_icount = dp->dad_na_icount = 0; 1335 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1336 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1337 1338 /* Add this to the dadq and add a reference for the dadq. */ 1339 refcount_init(&dp->dad_refcnt, 1); 1340 nd6_dad_add(dp); 1341 nd6_dad_starttimer(dp, delay); 1342 DADQ_WUNLOCK(); 1343 } 1344 1345 /* 1346 * terminate DAD unconditionally. used for address removals. 1347 */ 1348 void 1349 nd6_dad_stop(struct ifaddr *ifa) 1350 { 1351 struct dadq *dp; 1352 1353 DADQ_WLOCK(); 1354 dp = nd6_dad_find(ifa, NULL); 1355 if (dp == NULL) { 1356 DADQ_WUNLOCK(); 1357 /* DAD wasn't started yet */ 1358 return; 1359 } 1360 1361 /* 1362 * Acquire a temporary reference so that we can safely stop the callout. 1363 */ 1364 (void)refcount_acquire(&dp->dad_refcnt); 1365 nd6_dad_del(dp); 1366 DADQ_WUNLOCK(); 1367 1368 nd6_dad_stoptimer(dp); 1369 nd6_dad_rele(dp); 1370 } 1371 1372 static void 1373 nd6_dad_timer(void *arg) 1374 { 1375 struct dadq *dp = arg; 1376 struct ifaddr *ifa = dp->dad_ifa; 1377 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1378 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1379 char ip6buf[INET6_ADDRSTRLEN]; 1380 struct epoch_tracker et; 1381 1382 CURVNET_SET(dp->dad_vnet); 1383 KASSERT(ia != NULL, ("DAD entry %p with no address", dp)); 1384 1385 NET_EPOCH_ENTER(et); 1386 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1387 /* Do not need DAD for ifdisabled interface. */ 1388 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1389 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1390 goto err; 1391 } 1392 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1393 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1394 "%s(%s)\n", 1395 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1396 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1397 goto err; 1398 } 1399 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1400 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1401 "%s(%s)\n", 1402 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1403 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1404 goto err; 1405 } 1406 1407 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1408 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1409 (((ifp->if_flags & IFF_UP) == 0) || 1410 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1411 nd6log((LOG_INFO, "%s: could not run DAD " 1412 "because the interface was down or not running.\n", 1413 if_name(ifa->ifa_ifp))); 1414 goto err; 1415 } 1416 1417 /* Need more checks? */ 1418 if (dp->dad_ns_ocount < dp->dad_count) { 1419 /* 1420 * We have more NS to go. Send NS packet for DAD. 1421 */ 1422 nd6_dad_starttimer(dp, 1423 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1424 nd6_dad_ns_output(dp); 1425 goto done; 1426 } else { 1427 /* 1428 * We have transmitted sufficient number of DAD packets. 1429 * See what we've got. 1430 */ 1431 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) { 1432 /* We've seen NS or NA, means DAD has failed. */ 1433 nd6_dad_duplicated(ifa, dp); 1434 } else if (V_dad_enhanced != 0 && 1435 dp->dad_ns_lcount > 0 && 1436 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1437 /* 1438 * Sec. 4.1 in RFC 7527 requires transmission of 1439 * additional probes until the loopback condition 1440 * becomes clear when a looped back probe is detected. 1441 */ 1442 log(LOG_ERR, "%s: a looped back NS message is " 1443 "detected during DAD for %s. " 1444 "Another DAD probes are being sent.\n", 1445 if_name(ifa->ifa_ifp), 1446 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1447 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1448 /* 1449 * Send an NS immediately and increase dad_count by 1450 * V_nd6_mmaxtries - 1. 1451 */ 1452 dp->dad_count = 1453 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1454 nd6_dad_starttimer(dp, 1455 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1456 nd6_dad_ns_output(dp); 1457 goto done; 1458 } else { 1459 /* 1460 * We are done with DAD. No NA came, no NS came. 1461 * No duplicate address found. Check IFDISABLED flag 1462 * again in case that it is changed between the 1463 * beginning of this function and here. 1464 */ 1465 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1466 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1467 1468 nd6log((LOG_DEBUG, 1469 "%s: DAD complete for %s - no duplicates found\n", 1470 if_name(ifa->ifa_ifp), 1471 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1472 if (dp->dad_ns_lcount > 0) 1473 log(LOG_ERR, "%s: DAD completed while " 1474 "a looped back NS message is detected " 1475 "during DAD for %s.\n", 1476 if_name(ifa->ifa_ifp), 1477 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1478 } 1479 } 1480 err: 1481 nd6_dad_del(dp); 1482 DADQ_WUNLOCK(); 1483 done: 1484 NET_EPOCH_EXIT(et); 1485 CURVNET_RESTORE(); 1486 } 1487 1488 static void 1489 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1490 { 1491 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1492 struct ifnet *ifp; 1493 char ip6buf[INET6_ADDRSTRLEN]; 1494 1495 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1496 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1497 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1498 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1499 dp->dad_na_icount); 1500 1501 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1502 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1503 1504 ifp = ifa->ifa_ifp; 1505 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1506 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1507 log(LOG_ERR, "%s: manual intervention required\n", 1508 if_name(ifp)); 1509 1510 /* 1511 * If the address is a link-local address formed from an interface 1512 * identifier based on the hardware address which is supposed to be 1513 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1514 * operation on the interface SHOULD be disabled. 1515 * [RFC 4862, Section 5.4.5] 1516 */ 1517 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1518 struct in6_addr in6; 1519 1520 /* 1521 * To avoid over-reaction, we only apply this logic when we are 1522 * very sure that hardware addresses are supposed to be unique. 1523 */ 1524 switch (ifp->if_type) { 1525 case IFT_ETHER: 1526 case IFT_ATM: 1527 case IFT_IEEE1394: 1528 case IFT_INFINIBAND: 1529 in6 = ia->ia_addr.sin6_addr; 1530 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1531 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1532 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1533 log(LOG_ERR, "%s: possible hardware address " 1534 "duplication detected, disable IPv6\n", 1535 if_name(ifp)); 1536 } 1537 break; 1538 } 1539 } 1540 } 1541 1542 /* 1543 * Transmit a neighbour solicitation for the purpose of DAD. Returns with the 1544 * DAD queue unlocked. 1545 */ 1546 static void 1547 nd6_dad_ns_output(struct dadq *dp) 1548 { 1549 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1550 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1551 int i; 1552 1553 DADQ_WLOCK_ASSERT(); 1554 1555 dp->dad_ns_tcount++; 1556 if ((ifp->if_flags & IFF_UP) == 0) { 1557 DADQ_WUNLOCK(); 1558 return; 1559 } 1560 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1561 DADQ_WUNLOCK(); 1562 return; 1563 } 1564 1565 dp->dad_ns_ocount++; 1566 if (V_dad_enhanced != 0) { 1567 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1568 dp->dad_nonce[i] = arc4random(); 1569 /* 1570 * XXXHRS: Note that in the case that 1571 * DupAddrDetectTransmits > 1, multiple NS messages with 1572 * different nonces can be looped back in an unexpected 1573 * order. The current implementation recognizes only 1574 * the latest nonce on the sender side. Practically it 1575 * should work well in almost all cases. 1576 */ 1577 } 1578 DADQ_WUNLOCK(); 1579 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1580 (uint8_t *)&dp->dad_nonce[0]); 1581 } 1582 1583 static void 1584 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1585 { 1586 struct dadq *dp; 1587 1588 if (ifa == NULL) 1589 panic("ifa == NULL in nd6_dad_ns_input"); 1590 1591 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1592 if (V_dad_enhanced == 0) 1593 ndopt_nonce = NULL; 1594 DADQ_RLOCK(); 1595 dp = nd6_dad_find(ifa, ndopt_nonce); 1596 if (dp != NULL) 1597 dp->dad_ns_icount++; 1598 DADQ_RUNLOCK(); 1599 } 1600 1601 static void 1602 nd6_dad_na_input(struct ifaddr *ifa) 1603 { 1604 struct dadq *dp; 1605 1606 if (ifa == NULL) 1607 panic("ifa == NULL in nd6_dad_na_input"); 1608 1609 DADQ_RLOCK(); 1610 dp = nd6_dad_find(ifa, NULL); 1611 if (dp != NULL) 1612 dp->dad_na_icount++; 1613 DADQ_RUNLOCK(); 1614 } 1615