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sys/netinet6/nd6_nbr.c
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1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $ 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 #include "opt_ipsec.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/eventhandler.h> 44 #include <sys/malloc.h> 45 #include <sys/libkern.h> 46 #include <sys/lock.h> 47 #include <sys/rwlock.h> 48 #include <sys/mbuf.h> 49 #include <sys/socket.h> 50 #include <sys/sockio.h> 51 #include <sys/time.h> 52 #include <sys/kernel.h> 53 #include <sys/errno.h> 54 #include <sys/sysctl.h> 55 #include <sys/syslog.h> 56 #include <sys/queue.h> 57 #include <sys/callout.h> 58 #include <sys/refcount.h> 59 60 #include <net/if.h> 61 #include <net/if_types.h> 62 #include <net/if_dl.h> 63 #include <net/if_var.h> 64 #include <net/route.h> 65 #include <net/vnet.h> 66 67 #include <netinet/in.h> 68 #include <netinet/in_var.h> 69 #include <net/if_llatbl.h> 70 #include <netinet6/in6_var.h> 71 #include <netinet6/in6_ifattach.h> 72 #include <netinet/ip6.h> 73 #include <netinet6/ip6_var.h> 74 #include <netinet6/scope6_var.h> 75 #include <netinet6/nd6.h> 76 #include <netinet/icmp6.h> 77 #include <netinet/ip_carp.h> 78 #include <netinet6/send.h> 79 80 #define SDL(s) ((struct sockaddr_dl *)s) 81 82 struct dadq; 83 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *); 84 static void nd6_dad_add(struct dadq *dp); 85 static void nd6_dad_del(struct dadq *dp); 86 static void nd6_dad_rele(struct dadq *); 87 static void nd6_dad_starttimer(struct dadq *, int); 88 static void nd6_dad_stoptimer(struct dadq *); 89 static void nd6_dad_timer(void *); 90 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *); 91 static void nd6_dad_ns_output(struct dadq *); 92 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *); 93 static void nd6_dad_na_input(struct ifaddr *); 94 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 95 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 96 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *, 97 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int); 98 99 static struct ifaddr *nd6_proxy_fill_sdl(struct ifnet *, 100 const struct in6_addr *, struct sockaddr_dl *); 101 102 VNET_DEFINE_STATIC(int, dad_enhanced) = 1; 103 #define V_dad_enhanced VNET(dad_enhanced) 104 105 SYSCTL_DECL(_net_inet6_ip6); 106 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW, 107 &VNET_NAME(dad_enhanced), 0, 108 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD."); 109 110 VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to 111 transmit DAD packet */ 112 #define V_dad_maxtry VNET(dad_maxtry) 113 114 /* 115 * Input a Neighbor Solicitation Message. 116 * 117 * Based on RFC 2461 118 * Based on RFC 2462 (duplicate address detection) 119 */ 120 void 121 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 122 { 123 struct ifnet *ifp; 124 struct ip6_hdr *ip6; 125 struct nd_neighbor_solicit *nd_ns; 126 struct in6_addr daddr6, myaddr6, saddr6, taddr6; 127 struct ifaddr *ifa; 128 struct sockaddr_dl proxydl; 129 union nd_opts ndopts; 130 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 131 char *lladdr; 132 int anycast, lladdrlen, proxy, rflag, tentative, tlladdr; 133 134 ifa = NULL; 135 136 /* RFC 6980: Nodes MUST silently ignore fragments */ 137 if(m->m_flags & M_FRAGMENTED) 138 goto freeit; 139 140 ifp = m->m_pkthdr.rcvif; 141 ip6 = mtod(m, struct ip6_hdr *); 142 if (__predict_false(ip6->ip6_hlim != 255)) { 143 ICMP6STAT_INC(icp6s_invlhlim); 144 nd6log((LOG_ERR, 145 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 146 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 147 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 148 goto bads; 149 } 150 151 if (m->m_len < off + icmp6len) { 152 m = m_pullup(m, off + icmp6len); 153 if (m == NULL) { 154 IP6STAT_INC(ip6s_exthdrtoolong); 155 return; 156 } 157 } 158 ip6 = mtod(m, struct ip6_hdr *); 159 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 160 161 saddr6 = ip6->ip6_src; 162 daddr6 = ip6->ip6_dst; 163 taddr6 = nd_ns->nd_ns_target; 164 if (in6_setscope(&taddr6, ifp, NULL) != 0) 165 goto bad; 166 167 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 168 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 169 rflag = 0; 170 171 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 172 /* dst has to be a solicited node multicast address. */ 173 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 174 /* don't check ifindex portion */ 175 daddr6.s6_addr32[1] == 0 && 176 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 177 daddr6.s6_addr8[12] == 0xff) { 178 ; /* good */ 179 } else { 180 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 181 "(wrong ip6 dst)\n")); 182 goto bad; 183 } 184 } else if (!V_nd6_onlink_ns_rfc4861) { 185 struct sockaddr_in6 src_sa6; 186 187 /* 188 * According to recent IETF discussions, it is not a good idea 189 * to accept a NS from an address which would not be deemed 190 * to be a neighbor otherwise. This point is expected to be 191 * clarified in future revisions of the specification. 192 */ 193 bzero(&src_sa6, sizeof(src_sa6)); 194 src_sa6.sin6_family = AF_INET6; 195 src_sa6.sin6_len = sizeof(src_sa6); 196 src_sa6.sin6_addr = saddr6; 197 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 198 nd6log((LOG_INFO, "nd6_ns_input: " 199 "NS packet from non-neighbor\n")); 200 goto bad; 201 } 202 } 203 204 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 205 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 206 goto bad; 207 } 208 209 icmp6len -= sizeof(*nd_ns); 210 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 211 if (nd6_options(&ndopts) < 0) { 212 nd6log((LOG_INFO, 213 "nd6_ns_input: invalid ND option, ignored\n")); 214 /* nd6_options have incremented stats */ 215 goto freeit; 216 } 217 218 lladdr = NULL; 219 lladdrlen = 0; 220 if (ndopts.nd_opts_src_lladdr) { 221 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 222 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 223 } 224 225 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 226 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 227 "(link-layer address option)\n")); 228 goto bad; 229 } 230 231 /* 232 * Attaching target link-layer address to the NA? 233 * (RFC 2461 7.2.4) 234 * 235 * NS IP dst is unicast/anycast MUST NOT add 236 * NS IP dst is solicited-node multicast MUST add 237 * 238 * In implementation, we add target link-layer address by default. 239 * We do not add one in MUST NOT cases. 240 */ 241 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 242 tlladdr = 0; 243 else 244 tlladdr = 1; 245 246 /* 247 * Target address (taddr6) must be either: 248 * (1) Valid unicast/anycast address for my receiving interface, 249 * (2) Unicast address for which I'm offering proxy service, or 250 * (3) "tentative" address on which DAD is being performed. 251 */ 252 /* (1) and (3) check. */ 253 if (ifp->if_carp) 254 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 255 else 256 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 257 258 /* (2) check. */ 259 proxy = 0; 260 if (ifa == NULL) { 261 if ((ifa = nd6_proxy_fill_sdl(ifp, &taddr6, &proxydl)) != NULL) 262 proxy = 1; 263 } 264 if (ifa == NULL) { 265 /* 266 * We've got an NS packet, and we don't have that adddress 267 * assigned for us. We MUST silently ignore it. 268 * See RFC2461 7.2.3. 269 */ 270 goto freeit; 271 } 272 myaddr6 = *IFA_IN6(ifa); 273 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 274 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 275 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 276 goto freeit; 277 278 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 279 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 280 "(if %d, NS packet %d)\n", 281 ip6_sprintf(ip6bufs, &taddr6), 282 ifp->if_addrlen, lladdrlen - 2)); 283 goto bad; 284 } 285 286 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 287 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 288 ip6_sprintf(ip6bufs, &saddr6))); 289 goto freeit; 290 } 291 292 /* 293 * We have neighbor solicitation packet, with target address equals to 294 * one of my tentative address. 295 * 296 * src addr how to process? 297 * --- --- 298 * multicast of course, invalid (rejected in ip6_input) 299 * unicast somebody is doing address resolution -> ignore 300 * unspec dup address detection 301 * 302 * The processing is defined in RFC 2462. 303 */ 304 if (tentative) { 305 /* 306 * If source address is unspecified address, it is for 307 * duplicate address detection. 308 * 309 * If not, the packet is for addess resolution; 310 * silently ignore it. 311 */ 312 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 313 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 314 315 goto freeit; 316 } 317 318 /* 319 * If the source address is unspecified address, entries must not 320 * be created or updated. 321 * It looks that sender is performing DAD. Output NA toward 322 * all-node multicast address, to tell the sender that I'm using 323 * the address. 324 * S bit ("solicited") must be zero. 325 */ 326 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 327 struct in6_addr in6_all; 328 329 in6_all = in6addr_linklocal_allnodes; 330 if (in6_setscope(&in6_all, ifp, NULL) != 0) 331 goto bad; 332 nd6_na_output_fib(ifp, &in6_all, &taddr6, 333 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 334 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 335 M_GETFIB(m)); 336 goto freeit; 337 } 338 339 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 340 ND_NEIGHBOR_SOLICIT, 0); 341 342 nd6_na_output_fib(ifp, &saddr6, &taddr6, 343 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 344 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 345 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 346 freeit: 347 if (ifa != NULL) 348 ifa_free(ifa); 349 m_freem(m); 350 return; 351 352 bad: 353 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 354 ip6_sprintf(ip6bufs, &saddr6))); 355 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 356 ip6_sprintf(ip6bufs, &daddr6))); 357 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 358 ip6_sprintf(ip6bufs, &taddr6))); 359 bads: 360 ICMP6STAT_INC(icp6s_badns); 361 if (ifa != NULL) 362 ifa_free(ifa); 363 m_freem(m); 364 } 365 366 static struct ifaddr * 367 nd6_proxy_fill_sdl(struct ifnet *ifp, const struct in6_addr *taddr6, 368 struct sockaddr_dl *sdl) 369 { 370 struct ifaddr *ifa; 371 struct llentry *ln; 372 373 ifa = NULL; 374 ln = nd6_lookup(taddr6, LLE_SF(AF_INET6, 0), ifp); 375 if (ln == NULL) 376 return (ifa); 377 if ((ln->la_flags & (LLE_PUB | LLE_VALID)) == (LLE_PUB | LLE_VALID)) { 378 link_init_sdl(ifp, (struct sockaddr *)sdl, ifp->if_type); 379 sdl->sdl_alen = ifp->if_addrlen; 380 bcopy(ln->ll_addr, &sdl->sdl_data, ifp->if_addrlen); 381 LLE_RUNLOCK(ln); 382 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 383 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 384 } else 385 LLE_RUNLOCK(ln); 386 387 return (ifa); 388 } 389 390 /* 391 * Output a Neighbor Solicitation Message. Caller specifies: 392 * - ICMP6 header source IP6 address 393 * - ND6 header target IP6 address 394 * - ND6 header source datalink address 395 * 396 * Based on RFC 2461 397 * Based on RFC 2462 (duplicate address detection) 398 * 399 * ln - for source address determination 400 * nonce - If non-NULL, NS is used for duplicate address detection and 401 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 402 */ 403 static void 404 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 405 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 406 uint8_t *nonce, u_int fibnum) 407 { 408 struct mbuf *m; 409 struct m_tag *mtag; 410 struct ip6_hdr *ip6; 411 struct nd_neighbor_solicit *nd_ns; 412 struct ip6_moptions im6o; 413 int icmp6len; 414 int maxlen; 415 416 NET_EPOCH_ASSERT(); 417 418 if (IN6_IS_ADDR_MULTICAST(taddr6)) 419 return; 420 421 /* estimate the size of message */ 422 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 423 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 424 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 425 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 426 __func__, max_linkhdr, maxlen, MCLBYTES)); 427 428 if (max_linkhdr + maxlen > MHLEN) 429 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 430 else 431 m = m_gethdr(M_NOWAIT, MT_DATA); 432 if (m == NULL) 433 return; 434 M_SETFIB(m, fibnum); 435 436 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 437 m->m_flags |= M_MCAST; 438 im6o.im6o_multicast_ifp = ifp; 439 im6o.im6o_multicast_hlim = 255; 440 im6o.im6o_multicast_loop = 0; 441 } 442 443 icmp6len = sizeof(*nd_ns); 444 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 445 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 446 447 /* fill neighbor solicitation packet */ 448 ip6 = mtod(m, struct ip6_hdr *); 449 ip6->ip6_flow = 0; 450 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 451 ip6->ip6_vfc |= IPV6_VERSION; 452 /* ip6->ip6_plen will be set later */ 453 ip6->ip6_nxt = IPPROTO_ICMPV6; 454 ip6->ip6_hlim = 255; 455 if (daddr6) 456 ip6->ip6_dst = *daddr6; 457 else { 458 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 459 ip6->ip6_dst.s6_addr16[1] = 0; 460 ip6->ip6_dst.s6_addr32[1] = 0; 461 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 462 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 463 ip6->ip6_dst.s6_addr8[12] = 0xff; 464 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 465 goto bad; 466 } 467 if (nonce == NULL) { 468 char ip6buf[INET6_ADDRSTRLEN]; 469 struct ifaddr *ifa = NULL; 470 471 /* 472 * RFC2461 7.2.2: 473 * "If the source address of the packet prompting the 474 * solicitation is the same as one of the addresses assigned 475 * to the outgoing interface, that address SHOULD be placed 476 * in the IP Source Address of the outgoing solicitation. 477 * Otherwise, any one of the addresses assigned to the 478 * interface should be used." 479 * 480 * We use the source address for the prompting packet 481 * (saddr6), if saddr6 belongs to the outgoing interface. 482 * Otherwise, we perform the source address selection as usual. 483 */ 484 if (saddr6 != NULL) 485 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 486 if (ifa == NULL) { 487 int error; 488 struct in6_addr dst6, src6; 489 uint32_t scopeid; 490 491 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); 492 error = in6_selectsrc_addr(fibnum, &dst6, 493 scopeid, ifp, &src6, NULL); 494 if (error) { 495 nd6log((LOG_DEBUG, "%s: source can't be " 496 "determined: dst=%s, error=%d\n", __func__, 497 ip6_sprintf(ip6buf, &dst6), 498 error)); 499 goto bad; 500 } 501 ip6->ip6_src = src6; 502 } else 503 ip6->ip6_src = *saddr6; 504 505 if (ifp->if_carp != NULL) { 506 /* 507 * Check that selected source address belongs to 508 * CARP addresses. 509 */ 510 if (ifa == NULL) 511 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, 512 &ip6->ip6_src); 513 /* 514 * Do not send NS for CARP address if we are not 515 * the CARP master. 516 */ 517 if (ifa != NULL && ifa->ifa_carp != NULL && 518 !(*carp_master_p)(ifa)) { 519 log(LOG_DEBUG, 520 "nd6_ns_output: NS from BACKUP CARP address %s\n", 521 ip6_sprintf(ip6buf, &ip6->ip6_src)); 522 ifa_free(ifa); 523 goto bad; 524 } 525 } 526 if (ifa != NULL) 527 ifa_free(ifa); 528 } else { 529 /* 530 * Source address for DAD packet must always be IPv6 531 * unspecified address. (0::0) 532 * We actually don't have to 0-clear the address (we did it 533 * above), but we do so here explicitly to make the intention 534 * clearer. 535 */ 536 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 537 } 538 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 539 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 540 nd_ns->nd_ns_code = 0; 541 nd_ns->nd_ns_reserved = 0; 542 nd_ns->nd_ns_target = *taddr6; 543 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 544 545 /* 546 * Add source link-layer address option. 547 * 548 * spec implementation 549 * --- --- 550 * DAD packet MUST NOT do not add the option 551 * there's no link layer address: 552 * impossible do not add the option 553 * there's link layer address: 554 * Multicast NS MUST add one add the option 555 * Unicast NS SHOULD add one add the option 556 */ 557 if (nonce == NULL) { 558 struct nd_opt_hdr *nd_opt; 559 char *mac; 560 int optlen; 561 562 mac = NULL; 563 if (ifp->if_carp) 564 mac = (*carp_macmatch6_p)(ifp, m, &ip6->ip6_src); 565 if (mac == NULL) 566 mac = nd6_ifptomac(ifp); 567 568 if (mac != NULL) { 569 nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 570 optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 571 /* 8 byte alignments... */ 572 optlen = (optlen + 7) & ~7; 573 m->m_pkthdr.len += optlen; 574 m->m_len += optlen; 575 icmp6len += optlen; 576 bzero(nd_opt, optlen); 577 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 578 nd_opt->nd_opt_len = optlen >> 3; 579 bcopy(mac, nd_opt + 1, ifp->if_addrlen); 580 } 581 } 582 /* 583 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 584 * This behavior is documented as Enhanced Duplicate Address 585 * Detection in RFC 7527. 586 * net.inet6.ip6.dad_enhanced=0 disables this. 587 */ 588 if (V_dad_enhanced != 0 && nonce != NULL) { 589 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 590 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 591 /* 8-byte alignment is required. */ 592 optlen = (optlen + 7) & ~7; 593 594 m->m_pkthdr.len += optlen; 595 m->m_len += optlen; 596 icmp6len += optlen; 597 bzero((caddr_t)nd_opt, optlen); 598 nd_opt->nd_opt_type = ND_OPT_NONCE; 599 nd_opt->nd_opt_len = optlen >> 3; 600 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 601 } 602 ip6->ip6_plen = htons((u_short)icmp6len); 603 nd_ns->nd_ns_cksum = 0; 604 nd_ns->nd_ns_cksum = 605 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 606 607 if (send_sendso_input_hook != NULL) { 608 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 609 sizeof(unsigned short), M_NOWAIT); 610 if (mtag == NULL) 611 goto bad; 612 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 613 m_tag_prepend(m, mtag); 614 } 615 616 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 617 &im6o, NULL, NULL); 618 icmp6_ifstat_inc(ifp, ifs6_out_msg); 619 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 620 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 621 622 return; 623 624 bad: 625 m_freem(m); 626 } 627 628 #ifndef BURN_BRIDGES 629 void 630 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 631 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 632 { 633 634 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 635 } 636 #endif 637 /* 638 * Neighbor advertisement input handling. 639 * 640 * Based on RFC 2461 641 * Based on RFC 2462 (duplicate address detection) 642 * 643 * the following items are not implemented yet: 644 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 645 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 646 */ 647 void 648 nd6_na_input(struct mbuf *m, int off, int icmp6len) 649 { 650 struct ifnet *ifp; 651 struct ip6_hdr *ip6; 652 struct ifaddr *ifa; 653 struct llentry *ln; 654 struct mbuf *chain; 655 struct nd_neighbor_advert *nd_na; 656 struct in6_addr daddr6, taddr6; 657 union nd_opts ndopts; 658 u_char linkhdr[LLE_MAX_LINKHDR]; 659 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 660 char *lladdr; 661 size_t linkhdrsize; 662 int flags, is_override, is_router, is_solicited; 663 int lladdr_off, lladdrlen, checklink; 664 bool flush_holdchain = false; 665 666 NET_EPOCH_ASSERT(); 667 668 chain = NULL; 669 ln = NULL; 670 checklink = 0; 671 672 /* RFC 6980: Nodes MUST silently ignore fragments */ 673 if(m->m_flags & M_FRAGMENTED) 674 goto freeit; 675 676 ifp = m->m_pkthdr.rcvif; 677 ip6 = mtod(m, struct ip6_hdr *); 678 if (__predict_false(ip6->ip6_hlim != 255)) { 679 ICMP6STAT_INC(icp6s_invlhlim); 680 nd6log((LOG_ERR, 681 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 682 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 683 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 684 goto bad; 685 } 686 687 if (m->m_len < off + icmp6len) { 688 m = m_pullup(m, off + icmp6len); 689 if (m == NULL) { 690 IP6STAT_INC(ip6s_exthdrtoolong); 691 return; 692 } 693 } 694 ip6 = mtod(m, struct ip6_hdr *); 695 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 696 697 flags = nd_na->nd_na_flags_reserved; 698 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 699 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 700 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 701 702 taddr6 = nd_na->nd_na_target; 703 if (in6_setscope(&taddr6, ifp, NULL)) 704 goto bad; /* XXX: impossible */ 705 706 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 707 nd6log((LOG_ERR, 708 "nd6_na_input: invalid target address %s\n", 709 ip6_sprintf(ip6bufs, &taddr6))); 710 goto bad; 711 } 712 713 daddr6 = ip6->ip6_dst; 714 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 715 if (is_solicited) { 716 nd6log((LOG_ERR, 717 "nd6_na_input: a solicited adv is multicasted\n")); 718 goto bad; 719 } 720 721 icmp6len -= sizeof(*nd_na); 722 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 723 if (nd6_options(&ndopts) < 0) { 724 nd6log((LOG_INFO, 725 "nd6_na_input: invalid ND option, ignored\n")); 726 /* nd6_options have incremented stats */ 727 goto freeit; 728 } 729 730 lladdr = NULL; 731 lladdrlen = 0; 732 if (ndopts.nd_opts_tgt_lladdr) { 733 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 734 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 735 } 736 737 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 738 if (ifa != NULL && ifa->ifa_carp != NULL) { 739 /* 740 * Silently ignore NAs for CARP addresses if we are not 741 * the CARP master. 742 */ 743 if (!(*carp_master_p)(ifa)) { 744 log(LOG_DEBUG, 745 "nd6_na_input: NA for BACKUP CARP address %s\n", 746 ip6_sprintf(ip6bufs, &taddr6)); 747 ifa_free(ifa); 748 goto freeit; 749 } 750 } 751 /* 752 * Target address matches one of my interface address. 753 * 754 * If my address is tentative, this means that there's somebody 755 * already using the same address as mine. This indicates DAD failure. 756 * This is defined in RFC 2462. 757 * 758 * Otherwise, process as defined in RFC 2461. 759 */ 760 if (ifa 761 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 762 nd6_dad_na_input(ifa); 763 ifa_free(ifa); 764 goto freeit; 765 } 766 767 /* Just for safety, maybe unnecessary. */ 768 if (ifa) { 769 ifa_free(ifa); 770 log(LOG_ERR, 771 "nd6_na_input: duplicate IP6 address %s\n", 772 ip6_sprintf(ip6bufs, &taddr6)); 773 goto freeit; 774 } 775 776 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 777 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 778 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 779 ifp->if_addrlen, lladdrlen - 2)); 780 goto bad; 781 } 782 783 /* 784 * If no neighbor cache entry is found, NA SHOULD silently be 785 * discarded. 786 */ 787 ln = nd6_lookup(&taddr6, LLE_SF(AF_INET6, LLE_EXCLUSIVE), ifp); 788 if (ln == NULL) { 789 goto freeit; 790 } 791 792 /* 793 * Do not try to override static entry. 794 */ 795 if (ln->la_flags & LLE_STATIC) 796 goto freeit; 797 798 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 799 /* 800 * If the link-layer has address, and no lladdr option came, 801 * discard the packet. 802 */ 803 if (ifp->if_addrlen && lladdr == NULL) { 804 goto freeit; 805 } 806 807 /* 808 * Record link-layer address, and update the state. 809 */ 810 if (!nd6_try_set_entry_addr(ifp, ln, lladdr)) 811 goto freeit; 812 813 flush_holdchain = true; 814 if (is_solicited) 815 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 816 else 817 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 818 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 819 if ((ln->ln_router = is_router) != 0) { 820 /* 821 * This means a router's state has changed from 822 * non-reachable to probably reachable, and might 823 * affect the status of associated prefixes.. 824 */ 825 checklink = 1; 826 } 827 } else { 828 int llchange; 829 830 /* 831 * Check if the link-layer address has changed or not. 832 */ 833 if (lladdr == NULL) 834 llchange = 0; 835 else { 836 if (ln->la_flags & LLE_VALID) { 837 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 838 llchange = 1; 839 else 840 llchange = 0; 841 } else 842 llchange = 1; 843 } 844 845 /* 846 * This is VERY complex. Look at it with care. 847 * 848 * override solicit lladdr llchange action 849 * (L: record lladdr) 850 * 851 * 0 0 n -- (2c) 852 * 0 0 y n (2b) L 853 * 0 0 y y (1) REACHABLE->STALE 854 * 0 1 n -- (2c) *->REACHABLE 855 * 0 1 y n (2b) L *->REACHABLE 856 * 0 1 y y (1) REACHABLE->STALE 857 * 1 0 n -- (2a) 858 * 1 0 y n (2a) L 859 * 1 0 y y (2a) L *->STALE 860 * 1 1 n -- (2a) *->REACHABLE 861 * 1 1 y n (2a) L *->REACHABLE 862 * 1 1 y y (2a) L *->REACHABLE 863 */ 864 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 865 /* 866 * If state is REACHABLE, make it STALE. 867 * no other updates should be done. 868 */ 869 if (ln->ln_state == ND6_LLINFO_REACHABLE) 870 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 871 goto freeit; 872 } else if (is_override /* (2a) */ 873 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 874 || lladdr == NULL) { /* (2c) */ 875 /* 876 * Update link-local address, if any. 877 */ 878 if (lladdr != NULL) { 879 linkhdrsize = sizeof(linkhdr); 880 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 881 linkhdr, &linkhdrsize, &lladdr_off) != 0) 882 goto freeit; 883 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 884 linkhdrsize, lladdr_off) == 0) 885 goto freeit; 886 EVENTHANDLER_INVOKE(lle_event, ln, 887 LLENTRY_RESOLVED); 888 } 889 890 /* 891 * If solicited, make the state REACHABLE. 892 * If not solicited and the link-layer address was 893 * changed, make it STALE. 894 */ 895 if (is_solicited) 896 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 897 else { 898 if (lladdr != NULL && llchange) 899 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 900 } 901 } 902 903 if (ln->ln_router && !is_router) { 904 /* 905 * The peer dropped the router flag. 906 * Remove the sender from the Default Router List and 907 * update the Destination Cache entries. 908 */ 909 struct ifnet *nd6_ifp; 910 911 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 912 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 913 (ND_IFINFO(nd6_ifp)->flags & 914 ND6_IFF_ACCEPT_RTADV) != 0) 915 /* 916 * Even if the neighbor is not in the default 917 * router list, the neighbor may be used as a 918 * next hop for some destinations (e.g. redirect 919 * case). So we must call rt6_flush explicitly. 920 */ 921 rt6_flush(&ip6->ip6_src, ifp); 922 } 923 ln->ln_router = is_router; 924 } 925 /* XXX - QL 926 * Does this matter? 927 * rt->rt_flags &= ~RTF_REJECT; 928 */ 929 ln->la_asked = 0; 930 if (ln->la_hold != NULL) 931 chain = nd6_grab_holdchain(ln); 932 freeit: 933 if (ln != NULL) 934 LLE_WUNLOCK(ln); 935 936 if (chain != NULL) 937 nd6_flush_holdchain(ifp, ln, chain); 938 if (flush_holdchain) 939 nd6_flush_children_holdchain(ifp, ln); 940 941 if (checklink) 942 pfxlist_onlink_check(); 943 944 m_freem(m); 945 return; 946 947 bad: 948 if (ln != NULL) 949 LLE_WUNLOCK(ln); 950 951 ICMP6STAT_INC(icp6s_badna); 952 m_freem(m); 953 } 954 955 /* 956 * Neighbor advertisement output handling. 957 * 958 * Based on RFC 2461 959 * 960 * the following items are not implemented yet: 961 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 962 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 963 * 964 * tlladdr - 1 if include target link-layer address 965 * sdl0 - sockaddr_dl (= proxy NA) or NULL 966 */ 967 static void 968 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 969 const struct in6_addr *taddr6, u_long flags, int tlladdr, 970 struct sockaddr *sdl0, u_int fibnum) 971 { 972 struct mbuf *m; 973 struct m_tag *mtag; 974 struct ip6_hdr *ip6; 975 struct nd_neighbor_advert *nd_na; 976 struct ip6_moptions im6o; 977 struct in6_addr daddr6, dst6, src6; 978 uint32_t scopeid; 979 980 NET_EPOCH_ASSERT(); 981 982 int icmp6len, maxlen, error; 983 caddr_t mac = NULL; 984 985 daddr6 = *daddr6_0; /* make a local copy for modification */ 986 987 /* estimate the size of message */ 988 maxlen = sizeof(*ip6) + sizeof(*nd_na); 989 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 990 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 991 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 992 __func__, max_linkhdr, maxlen, MCLBYTES)); 993 994 if (max_linkhdr + maxlen > MHLEN) 995 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 996 else 997 m = m_gethdr(M_NOWAIT, MT_DATA); 998 if (m == NULL) 999 return; 1000 M_SETFIB(m, fibnum); 1001 1002 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 1003 m->m_flags |= M_MCAST; 1004 im6o.im6o_multicast_ifp = ifp; 1005 im6o.im6o_multicast_hlim = 255; 1006 im6o.im6o_multicast_loop = 0; 1007 } 1008 1009 icmp6len = sizeof(*nd_na); 1010 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 1011 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 1012 1013 /* fill neighbor advertisement packet */ 1014 ip6 = mtod(m, struct ip6_hdr *); 1015 ip6->ip6_flow = 0; 1016 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 1017 ip6->ip6_vfc |= IPV6_VERSION; 1018 ip6->ip6_nxt = IPPROTO_ICMPV6; 1019 ip6->ip6_hlim = 255; 1020 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 1021 /* reply to DAD */ 1022 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 1023 daddr6.s6_addr16[1] = 0; 1024 daddr6.s6_addr32[1] = 0; 1025 daddr6.s6_addr32[2] = 0; 1026 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 1027 if (in6_setscope(&daddr6, ifp, NULL)) 1028 goto bad; 1029 1030 flags &= ~ND_NA_FLAG_SOLICITED; 1031 } 1032 ip6->ip6_dst = daddr6; 1033 1034 /* 1035 * Select a source whose scope is the same as that of the dest. 1036 */ 1037 in6_splitscope(&daddr6, &dst6, &scopeid); 1038 error = in6_selectsrc_addr(fibnum, &dst6, 1039 scopeid, ifp, &src6, NULL); 1040 if (error) { 1041 char ip6buf[INET6_ADDRSTRLEN]; 1042 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1043 "determined: dst=%s, error=%d\n", 1044 ip6_sprintf(ip6buf, &daddr6), error)); 1045 goto bad; 1046 } 1047 ip6->ip6_src = src6; 1048 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1049 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1050 nd_na->nd_na_code = 0; 1051 nd_na->nd_na_target = *taddr6; 1052 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1053 1054 /* 1055 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1056 * see nd6_ns_input() for details. 1057 * Basically, if NS packet is sent to unicast/anycast addr, 1058 * target lladdr option SHOULD NOT be included. 1059 */ 1060 if (tlladdr) { 1061 /* 1062 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1063 * lladdr in sdl0. If we are not proxying (sending NA for 1064 * my address) use lladdr configured for the interface. 1065 */ 1066 if (sdl0 == NULL) { 1067 if (ifp->if_carp) 1068 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1069 if (mac == NULL) 1070 mac = nd6_ifptomac(ifp); 1071 } else if (sdl0->sa_family == AF_LINK) { 1072 struct sockaddr_dl *sdl; 1073 sdl = (struct sockaddr_dl *)sdl0; 1074 if (sdl->sdl_alen == ifp->if_addrlen) 1075 mac = LLADDR(sdl); 1076 } 1077 } 1078 if (tlladdr && mac) { 1079 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1080 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1081 1082 /* roundup to 8 bytes alignment! */ 1083 optlen = (optlen + 7) & ~7; 1084 1085 m->m_pkthdr.len += optlen; 1086 m->m_len += optlen; 1087 icmp6len += optlen; 1088 bzero((caddr_t)nd_opt, optlen); 1089 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1090 nd_opt->nd_opt_len = optlen >> 3; 1091 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1092 } else 1093 flags &= ~ND_NA_FLAG_OVERRIDE; 1094 1095 ip6->ip6_plen = htons((u_short)icmp6len); 1096 nd_na->nd_na_flags_reserved = flags; 1097 nd_na->nd_na_cksum = 0; 1098 nd_na->nd_na_cksum = 1099 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1100 1101 if (send_sendso_input_hook != NULL) { 1102 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1103 sizeof(unsigned short), M_NOWAIT); 1104 if (mtag == NULL) 1105 goto bad; 1106 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1107 m_tag_prepend(m, mtag); 1108 } 1109 1110 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1111 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1112 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1113 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1114 1115 return; 1116 1117 bad: 1118 m_freem(m); 1119 } 1120 1121 #ifndef BURN_BRIDGES 1122 void 1123 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1124 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1125 struct sockaddr *sdl0) 1126 { 1127 1128 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1129 RT_DEFAULT_FIB); 1130 } 1131 #endif 1132 1133 caddr_t 1134 nd6_ifptomac(struct ifnet *ifp) 1135 { 1136 switch (ifp->if_type) { 1137 case IFT_ETHER: 1138 case IFT_IEEE1394: 1139 case IFT_L2VLAN: 1140 case IFT_INFINIBAND: 1141 case IFT_BRIDGE: 1142 return IF_LLADDR(ifp); 1143 default: 1144 return NULL; 1145 } 1146 } 1147 1148 struct dadq { 1149 TAILQ_ENTRY(dadq) dad_list; 1150 struct ifaddr *dad_ifa; 1151 int dad_count; /* max NS to send */ 1152 int dad_ns_tcount; /* # of trials to send NS */ 1153 int dad_ns_ocount; /* NS sent so far */ 1154 int dad_ns_icount; 1155 int dad_na_icount; 1156 int dad_ns_lcount; /* looped back NS */ 1157 int dad_loopbackprobe; /* probing state for loopback detection */ 1158 struct callout dad_timer_ch; 1159 struct vnet *dad_vnet; 1160 u_int dad_refcnt; 1161 #define ND_OPT_NONCE_LEN32 \ 1162 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1163 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1164 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */ 1165 }; 1166 1167 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq); 1168 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock); 1169 #define V_dadq VNET(dadq) 1170 #define V_dad_rwlock VNET(dad_rwlock) 1171 1172 #define DADQ_LOCKPTR() (&V_dad_rwlock) 1173 #define DADQ_LOCK_INIT() rw_init(DADQ_LOCKPTR(), "nd6 DAD queue") 1174 #define DADQ_RLOCK() rw_rlock(DADQ_LOCKPTR()) 1175 #define DADQ_RUNLOCK() rw_runlock(DADQ_LOCKPTR()) 1176 #define DADQ_WLOCK() rw_wlock(DADQ_LOCKPTR()) 1177 #define DADQ_WUNLOCK() rw_wunlock(DADQ_LOCKPTR()) 1178 1179 #define DADQ_LOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_LOCKED); 1180 #define DADQ_RLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_RLOCKED); 1181 #define DADQ_WLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_WLOCKED); 1182 1183 static void 1184 nd6_dad_add(struct dadq *dp) 1185 { 1186 DADQ_WLOCK_ASSERT(); 1187 1188 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1189 dp->dad_ondadq = true; 1190 } 1191 1192 static void 1193 nd6_dad_del(struct dadq *dp) 1194 { 1195 DADQ_WLOCK_ASSERT(); 1196 1197 if (dp->dad_ondadq) { 1198 /* 1199 * Remove dp from the dadq and release the dadq's 1200 * reference. 1201 */ 1202 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1203 dp->dad_ondadq = false; 1204 nd6_dad_rele(dp); 1205 } 1206 } 1207 1208 static struct dadq * 1209 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1210 { 1211 struct dadq *dp; 1212 1213 DADQ_LOCK_ASSERT(); 1214 1215 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1216 if (dp->dad_ifa != ifa) 1217 continue; 1218 1219 /* 1220 * Skip if the nonce matches the received one. 1221 * +2 in the length is required because of type and 1222 * length fields are included in a header. 1223 */ 1224 if (n != NULL && 1225 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1226 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1227 ND_OPT_NONCE_LEN) == 0) { 1228 dp->dad_ns_lcount++; 1229 continue; 1230 } 1231 break; 1232 } 1233 1234 return (dp); 1235 } 1236 1237 static void 1238 nd6_dad_starttimer(struct dadq *dp, int ticks) 1239 { 1240 DADQ_WLOCK_ASSERT(); 1241 1242 callout_reset(&dp->dad_timer_ch, ticks, nd6_dad_timer, dp); 1243 } 1244 1245 static void 1246 nd6_dad_stoptimer(struct dadq *dp) 1247 { 1248 callout_drain(&dp->dad_timer_ch); 1249 } 1250 1251 static void 1252 nd6_dad_rele(struct dadq *dp) 1253 { 1254 if (refcount_release(&dp->dad_refcnt)) { 1255 KASSERT(!dp->dad_ondadq, ("dp %p still on DAD queue", dp)); 1256 ifa_free(dp->dad_ifa); 1257 free(dp, M_IP6NDP); 1258 } 1259 } 1260 1261 void 1262 nd6_dad_init(void) 1263 { 1264 DADQ_LOCK_INIT(); 1265 TAILQ_INIT(&V_dadq); 1266 } 1267 1268 /* 1269 * Start Duplicate Address Detection (DAD) for specified interface address. 1270 */ 1271 void 1272 nd6_dad_start(struct ifaddr *ifa, int delay) 1273 { 1274 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1275 struct dadq *dp; 1276 char ip6buf[INET6_ADDRSTRLEN]; 1277 1278 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0, 1279 ("starting DAD on non-tentative address %p", ifa)); 1280 1281 /* 1282 * If we don't need DAD, don't do it. 1283 * There are several cases: 1284 * - DAD is disabled globally or on the interface 1285 * - the interface address is anycast 1286 */ 1287 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 || 1288 V_ip6_dad_count == 0 || 1289 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) != 0) { 1290 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1291 return; 1292 } 1293 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 || 1294 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || 1295 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) != 0) 1296 return; 1297 1298 DADQ_WLOCK(); 1299 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1300 /* 1301 * DAD is already in progress. Let the existing entry 1302 * finish it. 1303 */ 1304 DADQ_WUNLOCK(); 1305 return; 1306 } 1307 1308 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1309 if (dp == NULL) { 1310 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1311 "%s(%s)\n", 1312 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1313 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1314 return; 1315 } 1316 callout_init_rw(&dp->dad_timer_ch, DADQ_LOCKPTR(), 1317 CALLOUT_RETURNUNLOCKED); 1318 #ifdef VIMAGE 1319 dp->dad_vnet = curvnet; 1320 #endif 1321 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1322 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1323 1324 /* 1325 * Send NS packet for DAD, ip6_dad_count times. 1326 * Note that we must delay the first transmission, if this is the 1327 * first packet to be sent from the interface after interface 1328 * (re)initialization. 1329 */ 1330 dp->dad_ifa = ifa; 1331 ifa_ref(dp->dad_ifa); 1332 dp->dad_count = V_ip6_dad_count; 1333 dp->dad_ns_icount = dp->dad_na_icount = 0; 1334 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1335 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1336 1337 /* Add this to the dadq and add a reference for the dadq. */ 1338 refcount_init(&dp->dad_refcnt, 1); 1339 nd6_dad_add(dp); 1340 nd6_dad_starttimer(dp, delay); 1341 DADQ_WUNLOCK(); 1342 } 1343 1344 /* 1345 * terminate DAD unconditionally. used for address removals. 1346 */ 1347 void 1348 nd6_dad_stop(struct ifaddr *ifa) 1349 { 1350 struct dadq *dp; 1351 1352 DADQ_WLOCK(); 1353 dp = nd6_dad_find(ifa, NULL); 1354 if (dp == NULL) { 1355 DADQ_WUNLOCK(); 1356 /* DAD wasn't started yet */ 1357 return; 1358 } 1359 1360 /* 1361 * Acquire a temporary reference so that we can safely stop the callout. 1362 */ 1363 (void)refcount_acquire(&dp->dad_refcnt); 1364 nd6_dad_del(dp); 1365 DADQ_WUNLOCK(); 1366 1367 nd6_dad_stoptimer(dp); 1368 nd6_dad_rele(dp); 1369 } 1370 1371 static void 1372 nd6_dad_timer(void *arg) 1373 { 1374 struct dadq *dp = arg; 1375 struct ifaddr *ifa = dp->dad_ifa; 1376 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1377 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1378 char ip6buf[INET6_ADDRSTRLEN]; 1379 struct epoch_tracker et; 1380 1381 CURVNET_SET(dp->dad_vnet); 1382 KASSERT(ia != NULL, ("DAD entry %p with no address", dp)); 1383 1384 NET_EPOCH_ENTER(et); 1385 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1386 /* Do not need DAD for ifdisabled interface. */ 1387 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1388 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1389 goto err; 1390 } 1391 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1392 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1393 "%s(%s)\n", 1394 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1395 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1396 goto err; 1397 } 1398 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1399 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1400 "%s(%s)\n", 1401 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1402 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1403 goto err; 1404 } 1405 1406 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1407 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1408 (((ifp->if_flags & IFF_UP) == 0) || 1409 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1410 nd6log((LOG_INFO, "%s: could not run DAD " 1411 "because the interface was down or not running.\n", 1412 if_name(ifa->ifa_ifp))); 1413 goto err; 1414 } 1415 1416 /* Need more checks? */ 1417 if (dp->dad_ns_ocount < dp->dad_count) { 1418 /* 1419 * We have more NS to go. Send NS packet for DAD. 1420 */ 1421 nd6_dad_starttimer(dp, 1422 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1423 nd6_dad_ns_output(dp); 1424 goto done; 1425 } else { 1426 /* 1427 * We have transmitted sufficient number of DAD packets. 1428 * See what we've got. 1429 */ 1430 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) { 1431 /* We've seen NS or NA, means DAD has failed. */ 1432 nd6_dad_duplicated(ifa, dp); 1433 } else if (V_dad_enhanced != 0 && 1434 dp->dad_ns_lcount > 0 && 1435 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1436 /* 1437 * Sec. 4.1 in RFC 7527 requires transmission of 1438 * additional probes until the loopback condition 1439 * becomes clear when a looped back probe is detected. 1440 */ 1441 log(LOG_ERR, "%s: a looped back NS message is " 1442 "detected during DAD for %s. " 1443 "Another DAD probes are being sent.\n", 1444 if_name(ifa->ifa_ifp), 1445 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1446 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1447 /* 1448 * Send an NS immediately and increase dad_count by 1449 * V_nd6_mmaxtries - 1. 1450 */ 1451 dp->dad_count = 1452 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1453 nd6_dad_starttimer(dp, 1454 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1455 nd6_dad_ns_output(dp); 1456 goto done; 1457 } else { 1458 /* 1459 * We are done with DAD. No NA came, no NS came. 1460 * No duplicate address found. Check IFDISABLED flag 1461 * again in case that it is changed between the 1462 * beginning of this function and here. 1463 */ 1464 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1465 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1466 1467 nd6log((LOG_DEBUG, 1468 "%s: DAD complete for %s - no duplicates found\n", 1469 if_name(ifa->ifa_ifp), 1470 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1471 if (dp->dad_ns_lcount > 0) 1472 log(LOG_ERR, "%s: DAD completed while " 1473 "a looped back NS message is detected " 1474 "during DAD for %s.\n", 1475 if_name(ifa->ifa_ifp), 1476 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1477 } 1478 } 1479 err: 1480 nd6_dad_del(dp); 1481 DADQ_WUNLOCK(); 1482 done: 1483 NET_EPOCH_EXIT(et); 1484 CURVNET_RESTORE(); 1485 } 1486 1487 static void 1488 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1489 { 1490 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1491 struct ifnet *ifp; 1492 char ip6buf[INET6_ADDRSTRLEN]; 1493 1494 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1495 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1496 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1497 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1498 dp->dad_na_icount); 1499 1500 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1501 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1502 1503 ifp = ifa->ifa_ifp; 1504 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1505 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1506 log(LOG_ERR, "%s: manual intervention required\n", 1507 if_name(ifp)); 1508 1509 /* 1510 * If the address is a link-local address formed from an interface 1511 * identifier based on the hardware address which is supposed to be 1512 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1513 * operation on the interface SHOULD be disabled. 1514 * [RFC 4862, Section 5.4.5] 1515 */ 1516 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1517 struct in6_addr in6; 1518 1519 /* 1520 * To avoid over-reaction, we only apply this logic when we are 1521 * very sure that hardware addresses are supposed to be unique. 1522 */ 1523 switch (ifp->if_type) { 1524 case IFT_ETHER: 1525 case IFT_ATM: 1526 case IFT_IEEE1394: 1527 case IFT_INFINIBAND: 1528 in6 = ia->ia_addr.sin6_addr; 1529 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1530 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1531 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1532 log(LOG_ERR, "%s: possible hardware address " 1533 "duplication detected, disable IPv6\n", 1534 if_name(ifp)); 1535 } 1536 break; 1537 } 1538 } 1539 } 1540 1541 /* 1542 * Transmit a neighbour solicitation for the purpose of DAD. Returns with the 1543 * DAD queue unlocked. 1544 */ 1545 static void 1546 nd6_dad_ns_output(struct dadq *dp) 1547 { 1548 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1549 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1550 int i; 1551 1552 DADQ_WLOCK_ASSERT(); 1553 1554 dp->dad_ns_tcount++; 1555 if ((ifp->if_flags & IFF_UP) == 0) { 1556 DADQ_WUNLOCK(); 1557 return; 1558 } 1559 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1560 DADQ_WUNLOCK(); 1561 return; 1562 } 1563 1564 dp->dad_ns_ocount++; 1565 if (V_dad_enhanced != 0) { 1566 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1567 dp->dad_nonce[i] = arc4random(); 1568 /* 1569 * XXXHRS: Note that in the case that 1570 * DupAddrDetectTransmits > 1, multiple NS messages with 1571 * different nonces can be looped back in an unexpected 1572 * order. The current implementation recognizes only 1573 * the latest nonce on the sender side. Practically it 1574 * should work well in almost all cases. 1575 */ 1576 } 1577 DADQ_WUNLOCK(); 1578 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1579 (uint8_t *)&dp->dad_nonce[0]); 1580 } 1581 1582 static void 1583 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1584 { 1585 struct dadq *dp; 1586 1587 if (ifa == NULL) 1588 panic("ifa == NULL in nd6_dad_ns_input"); 1589 1590 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1591 if (V_dad_enhanced == 0) 1592 ndopt_nonce = NULL; 1593 DADQ_RLOCK(); 1594 dp = nd6_dad_find(ifa, ndopt_nonce); 1595 if (dp != NULL) 1596 dp->dad_ns_icount++; 1597 DADQ_RUNLOCK(); 1598 } 1599 1600 static void 1601 nd6_dad_na_input(struct ifaddr *ifa) 1602 { 1603 struct dadq *dp; 1604 1605 if (ifa == NULL) 1606 panic("ifa == NULL in nd6_dad_na_input"); 1607 1608 DADQ_RLOCK(); 1609 dp = nd6_dad_find(ifa, NULL); 1610 if (dp != NULL) 1611 dp->dad_na_icount++; 1612 DADQ_RUNLOCK(); 1613 }
Cache object: 4fdea900e841dcafebeaf9d71fbe669a
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