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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 VNET_DEFINE_STATIC(int, dad_enhanced) = 1; 100 #define V_dad_enhanced VNET(dad_enhanced) 101 102 SYSCTL_DECL(_net_inet6_ip6); 103 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW, 104 &VNET_NAME(dad_enhanced), 0, 105 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD."); 106 107 VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to 108 transmit DAD packet */ 109 #define V_dad_maxtry VNET(dad_maxtry) 110 111 /* 112 * Input a Neighbor Solicitation Message. 113 * 114 * Based on RFC 2461 115 * Based on RFC 2462 (duplicate address detection) 116 */ 117 void 118 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 119 { 120 struct ifnet *ifp; 121 struct ip6_hdr *ip6; 122 struct nd_neighbor_solicit *nd_ns; 123 struct in6_addr daddr6, myaddr6, saddr6, taddr6; 124 struct ifaddr *ifa; 125 struct sockaddr_dl proxydl; 126 union nd_opts ndopts; 127 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 128 char *lladdr; 129 int anycast, lladdrlen, proxy, rflag, tentative, tlladdr; 130 131 ifa = NULL; 132 133 /* RFC 6980: Nodes MUST silently ignore fragments */ 134 if(m->m_flags & M_FRAGMENTED) 135 goto freeit; 136 137 ifp = m->m_pkthdr.rcvif; 138 ip6 = mtod(m, struct ip6_hdr *); 139 if (__predict_false(ip6->ip6_hlim != 255)) { 140 ICMP6STAT_INC(icp6s_invlhlim); 141 nd6log((LOG_ERR, 142 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 143 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 144 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 145 goto bads; 146 } 147 148 if (m->m_len < off + icmp6len) { 149 m = m_pullup(m, off + icmp6len); 150 if (m == NULL) { 151 IP6STAT_INC(ip6s_exthdrtoolong); 152 return; 153 } 154 } 155 ip6 = mtod(m, struct ip6_hdr *); 156 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 157 158 saddr6 = ip6->ip6_src; 159 daddr6 = ip6->ip6_dst; 160 taddr6 = nd_ns->nd_ns_target; 161 if (in6_setscope(&taddr6, ifp, NULL) != 0) 162 goto bad; 163 164 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 165 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 166 rflag = 0; 167 168 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 169 /* dst has to be a solicited node multicast address. */ 170 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 171 /* don't check ifindex portion */ 172 daddr6.s6_addr32[1] == 0 && 173 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 174 daddr6.s6_addr8[12] == 0xff) { 175 ; /* good */ 176 } else { 177 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 178 "(wrong ip6 dst)\n")); 179 goto bad; 180 } 181 } else if (!V_nd6_onlink_ns_rfc4861) { 182 struct sockaddr_in6 src_sa6; 183 184 /* 185 * According to recent IETF discussions, it is not a good idea 186 * to accept a NS from an address which would not be deemed 187 * to be a neighbor otherwise. This point is expected to be 188 * clarified in future revisions of the specification. 189 */ 190 bzero(&src_sa6, sizeof(src_sa6)); 191 src_sa6.sin6_family = AF_INET6; 192 src_sa6.sin6_len = sizeof(src_sa6); 193 src_sa6.sin6_addr = saddr6; 194 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 195 nd6log((LOG_INFO, "nd6_ns_input: " 196 "NS packet from non-neighbor\n")); 197 goto bad; 198 } 199 } 200 201 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 202 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 203 goto bad; 204 } 205 206 icmp6len -= sizeof(*nd_ns); 207 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 208 if (nd6_options(&ndopts) < 0) { 209 nd6log((LOG_INFO, 210 "nd6_ns_input: invalid ND option, ignored\n")); 211 /* nd6_options have incremented stats */ 212 goto freeit; 213 } 214 215 lladdr = NULL; 216 lladdrlen = 0; 217 if (ndopts.nd_opts_src_lladdr) { 218 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 219 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 220 } 221 222 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 223 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 224 "(link-layer address option)\n")); 225 goto bad; 226 } 227 228 /* 229 * Attaching target link-layer address to the NA? 230 * (RFC 2461 7.2.4) 231 * 232 * NS IP dst is unicast/anycast MUST NOT add 233 * NS IP dst is solicited-node multicast MUST add 234 * 235 * In implementation, we add target link-layer address by default. 236 * We do not add one in MUST NOT cases. 237 */ 238 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 239 tlladdr = 0; 240 else 241 tlladdr = 1; 242 243 /* 244 * Target address (taddr6) must be either: 245 * (1) Valid unicast/anycast address for my receiving interface, 246 * (2) Unicast address for which I'm offering proxy service, or 247 * (3) "tentative" address on which DAD is being performed. 248 */ 249 /* (1) and (3) check. */ 250 if (ifp->if_carp) 251 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 252 else 253 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 254 255 /* (2) check. */ 256 proxy = 0; 257 if (ifa == NULL) { 258 struct sockaddr_dl rt_gateway; 259 struct rt_addrinfo info; 260 struct sockaddr_in6 dst6; 261 262 bzero(&dst6, sizeof(dst6)); 263 dst6.sin6_len = sizeof(struct sockaddr_in6); 264 dst6.sin6_family = AF_INET6; 265 dst6.sin6_addr = taddr6; 266 267 bzero(&rt_gateway, sizeof(rt_gateway)); 268 rt_gateway.sdl_len = sizeof(rt_gateway); 269 bzero(&info, sizeof(info)); 270 info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway; 271 272 if (rib_lookup_info(ifp->if_fib, (struct sockaddr *)&dst6, 273 0, 0, &info) == 0) { 274 if ((info.rti_flags & RTF_ANNOUNCE) != 0 && 275 rt_gateway.sdl_family == AF_LINK) { 276 /* 277 * proxy NDP for single entry 278 */ 279 proxydl = *SDL(&rt_gateway); 280 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal( 281 ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 282 if (ifa) 283 proxy = 1; 284 } 285 } 286 } 287 if (ifa == NULL) { 288 /* 289 * We've got an NS packet, and we don't have that adddress 290 * assigned for us. We MUST silently ignore it. 291 * See RFC2461 7.2.3. 292 */ 293 goto freeit; 294 } 295 myaddr6 = *IFA_IN6(ifa); 296 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 297 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 298 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 299 goto freeit; 300 301 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 302 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 303 "(if %d, NS packet %d)\n", 304 ip6_sprintf(ip6bufs, &taddr6), 305 ifp->if_addrlen, lladdrlen - 2)); 306 goto bad; 307 } 308 309 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 310 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 311 ip6_sprintf(ip6bufs, &saddr6))); 312 goto freeit; 313 } 314 315 /* 316 * We have neighbor solicitation packet, with target address equals to 317 * one of my tentative address. 318 * 319 * src addr how to process? 320 * --- --- 321 * multicast of course, invalid (rejected in ip6_input) 322 * unicast somebody is doing address resolution -> ignore 323 * unspec dup address detection 324 * 325 * The processing is defined in RFC 2462. 326 */ 327 if (tentative) { 328 /* 329 * If source address is unspecified address, it is for 330 * duplicate address detection. 331 * 332 * If not, the packet is for addess resolution; 333 * silently ignore it. 334 */ 335 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 336 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 337 338 goto freeit; 339 } 340 341 /* 342 * If the source address is unspecified address, entries must not 343 * be created or updated. 344 * It looks that sender is performing DAD. Output NA toward 345 * all-node multicast address, to tell the sender that I'm using 346 * the address. 347 * S bit ("solicited") must be zero. 348 */ 349 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 350 struct in6_addr in6_all; 351 352 in6_all = in6addr_linklocal_allnodes; 353 if (in6_setscope(&in6_all, ifp, NULL) != 0) 354 goto bad; 355 nd6_na_output_fib(ifp, &in6_all, &taddr6, 356 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 357 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 358 M_GETFIB(m)); 359 goto freeit; 360 } 361 362 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 363 ND_NEIGHBOR_SOLICIT, 0); 364 365 nd6_na_output_fib(ifp, &saddr6, &taddr6, 366 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 367 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 368 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 369 freeit: 370 if (ifa != NULL) 371 ifa_free(ifa); 372 m_freem(m); 373 return; 374 375 bad: 376 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 377 ip6_sprintf(ip6bufs, &saddr6))); 378 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 379 ip6_sprintf(ip6bufs, &daddr6))); 380 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 381 ip6_sprintf(ip6bufs, &taddr6))); 382 bads: 383 ICMP6STAT_INC(icp6s_badns); 384 if (ifa != NULL) 385 ifa_free(ifa); 386 m_freem(m); 387 } 388 389 /* 390 * Output a Neighbor Solicitation Message. Caller specifies: 391 * - ICMP6 header source IP6 address 392 * - ND6 header target IP6 address 393 * - ND6 header source datalink address 394 * 395 * Based on RFC 2461 396 * Based on RFC 2462 (duplicate address detection) 397 * 398 * ln - for source address determination 399 * nonce - If non-NULL, NS is used for duplicate address detection and 400 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 401 */ 402 static void 403 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 404 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 405 uint8_t *nonce, u_int fibnum) 406 { 407 struct mbuf *m; 408 struct m_tag *mtag; 409 struct ip6_hdr *ip6; 410 struct nd_neighbor_solicit *nd_ns; 411 struct ip6_moptions im6o; 412 int icmp6len; 413 int maxlen; 414 caddr_t mac; 415 416 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 struct ifaddr *ifa = NULL; 469 470 /* 471 * RFC2461 7.2.2: 472 * "If the source address of the packet prompting the 473 * solicitation is the same as one of the addresses assigned 474 * to the outgoing interface, that address SHOULD be placed 475 * in the IP Source Address of the outgoing solicitation. 476 * Otherwise, any one of the addresses assigned to the 477 * interface should be used." 478 * 479 * We use the source address for the prompting packet 480 * (saddr6), if saddr6 belongs to the outgoing interface. 481 * Otherwise, we perform the source address selection as usual. 482 */ 483 484 if (saddr6 != NULL) 485 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 486 if (ifa != NULL) { 487 /* ip6_src set already. */ 488 ip6->ip6_src = *saddr6; 489 ifa_free(ifa); 490 } else { 491 int error; 492 struct in6_addr dst6, src6; 493 uint32_t scopeid; 494 495 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); 496 error = in6_selectsrc_addr(fibnum, &dst6, 497 scopeid, ifp, &src6, NULL); 498 if (error) { 499 char ip6buf[INET6_ADDRSTRLEN]; 500 nd6log((LOG_DEBUG, "%s: source can't be " 501 "determined: dst=%s, error=%d\n", __func__, 502 ip6_sprintf(ip6buf, &dst6), 503 error)); 504 goto bad; 505 } 506 ip6->ip6_src = src6; 507 } 508 } else { 509 /* 510 * Source address for DAD packet must always be IPv6 511 * unspecified address. (0::0) 512 * We actually don't have to 0-clear the address (we did it 513 * above), but we do so here explicitly to make the intention 514 * clearer. 515 */ 516 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 517 } 518 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 519 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 520 nd_ns->nd_ns_code = 0; 521 nd_ns->nd_ns_reserved = 0; 522 nd_ns->nd_ns_target = *taddr6; 523 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 524 525 /* 526 * Add source link-layer address option. 527 * 528 * spec implementation 529 * --- --- 530 * DAD packet MUST NOT do not add the option 531 * there's no link layer address: 532 * impossible do not add the option 533 * there's link layer address: 534 * Multicast NS MUST add one add the option 535 * Unicast NS SHOULD add one add the option 536 */ 537 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 538 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 539 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 540 /* 8 byte alignments... */ 541 optlen = (optlen + 7) & ~7; 542 543 m->m_pkthdr.len += optlen; 544 m->m_len += optlen; 545 icmp6len += optlen; 546 bzero((caddr_t)nd_opt, optlen); 547 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 548 nd_opt->nd_opt_len = optlen >> 3; 549 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 550 } 551 /* 552 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 553 * This behavior is documented as Enhanced Duplicate Address 554 * Detection in RFC 7527. 555 * net.inet6.ip6.dad_enhanced=0 disables this. 556 */ 557 if (V_dad_enhanced != 0 && nonce != NULL) { 558 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 559 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 560 /* 8-byte alignment is required. */ 561 optlen = (optlen + 7) & ~7; 562 563 m->m_pkthdr.len += optlen; 564 m->m_len += optlen; 565 icmp6len += optlen; 566 bzero((caddr_t)nd_opt, optlen); 567 nd_opt->nd_opt_type = ND_OPT_NONCE; 568 nd_opt->nd_opt_len = optlen >> 3; 569 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 570 } 571 ip6->ip6_plen = htons((u_short)icmp6len); 572 nd_ns->nd_ns_cksum = 0; 573 nd_ns->nd_ns_cksum = 574 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 575 576 if (send_sendso_input_hook != NULL) { 577 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 578 sizeof(unsigned short), M_NOWAIT); 579 if (mtag == NULL) 580 goto bad; 581 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 582 m_tag_prepend(m, mtag); 583 } 584 585 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 586 &im6o, NULL, NULL); 587 icmp6_ifstat_inc(ifp, ifs6_out_msg); 588 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 589 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 590 591 return; 592 593 bad: 594 m_freem(m); 595 } 596 597 #ifndef BURN_BRIDGES 598 void 599 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 600 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 601 { 602 603 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 604 } 605 #endif 606 /* 607 * Neighbor advertisement input handling. 608 * 609 * Based on RFC 2461 610 * Based on RFC 2462 (duplicate address detection) 611 * 612 * the following items are not implemented yet: 613 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 614 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 615 */ 616 void 617 nd6_na_input(struct mbuf *m, int off, int icmp6len) 618 { 619 struct ifnet *ifp; 620 struct ip6_hdr *ip6; 621 struct ifaddr *ifa; 622 struct llentry *ln; 623 struct mbuf *chain; 624 struct nd_neighbor_advert *nd_na; 625 struct in6_addr daddr6, taddr6; 626 union nd_opts ndopts; 627 u_char linkhdr[LLE_MAX_LINKHDR]; 628 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 629 char *lladdr; 630 size_t linkhdrsize; 631 int flags, is_override, is_router, is_solicited; 632 int lladdr_off, lladdrlen, checklink; 633 bool flush_holdchain = false; 634 635 NET_EPOCH_ASSERT(); 636 637 chain = NULL; 638 ln = NULL; 639 checklink = 0; 640 641 /* RFC 6980: Nodes MUST silently ignore fragments */ 642 if(m->m_flags & M_FRAGMENTED) 643 goto freeit; 644 645 ifp = m->m_pkthdr.rcvif; 646 ip6 = mtod(m, struct ip6_hdr *); 647 if (__predict_false(ip6->ip6_hlim != 255)) { 648 ICMP6STAT_INC(icp6s_invlhlim); 649 nd6log((LOG_ERR, 650 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 651 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 652 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 653 goto bad; 654 } 655 656 if (m->m_len < off + icmp6len) { 657 m = m_pullup(m, off + icmp6len); 658 if (m == NULL) { 659 IP6STAT_INC(ip6s_exthdrtoolong); 660 return; 661 } 662 } 663 ip6 = mtod(m, struct ip6_hdr *); 664 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 665 666 flags = nd_na->nd_na_flags_reserved; 667 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 668 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 669 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 670 671 taddr6 = nd_na->nd_na_target; 672 if (in6_setscope(&taddr6, ifp, NULL)) 673 goto bad; /* XXX: impossible */ 674 675 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 676 nd6log((LOG_ERR, 677 "nd6_na_input: invalid target address %s\n", 678 ip6_sprintf(ip6bufs, &taddr6))); 679 goto bad; 680 } 681 682 daddr6 = ip6->ip6_dst; 683 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 684 if (is_solicited) { 685 nd6log((LOG_ERR, 686 "nd6_na_input: a solicited adv is multicasted\n")); 687 goto bad; 688 } 689 690 icmp6len -= sizeof(*nd_na); 691 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 692 if (nd6_options(&ndopts) < 0) { 693 nd6log((LOG_INFO, 694 "nd6_na_input: invalid ND option, ignored\n")); 695 /* nd6_options have incremented stats */ 696 goto freeit; 697 } 698 699 lladdr = NULL; 700 lladdrlen = 0; 701 if (ndopts.nd_opts_tgt_lladdr) { 702 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 703 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 704 } 705 706 /* 707 * This effectively disables the DAD check on a non-master CARP 708 * address. 709 */ 710 if (ifp->if_carp) 711 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 712 else 713 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 714 715 /* 716 * Target address matches one of my interface address. 717 * 718 * If my address is tentative, this means that there's somebody 719 * already using the same address as mine. This indicates DAD failure. 720 * This is defined in RFC 2462. 721 * 722 * Otherwise, process as defined in RFC 2461. 723 */ 724 if (ifa 725 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 726 nd6_dad_na_input(ifa); 727 ifa_free(ifa); 728 goto freeit; 729 } 730 731 /* Just for safety, maybe unnecessary. */ 732 if (ifa) { 733 ifa_free(ifa); 734 log(LOG_ERR, 735 "nd6_na_input: duplicate IP6 address %s\n", 736 ip6_sprintf(ip6bufs, &taddr6)); 737 goto freeit; 738 } 739 740 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 741 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 742 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 743 ifp->if_addrlen, lladdrlen - 2)); 744 goto bad; 745 } 746 747 /* 748 * If no neighbor cache entry is found, NA SHOULD silently be 749 * discarded. 750 */ 751 ln = nd6_lookup(&taddr6, LLE_SF(AF_INET6, LLE_EXCLUSIVE), ifp); 752 if (ln == NULL) { 753 goto freeit; 754 } 755 756 /* 757 * Do not try to override static entry. 758 */ 759 if (ln->la_flags & LLE_STATIC) 760 goto freeit; 761 762 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 763 /* 764 * If the link-layer has address, and no lladdr option came, 765 * discard the packet. 766 */ 767 if (ifp->if_addrlen && lladdr == NULL) { 768 goto freeit; 769 } 770 771 /* 772 * Record link-layer address, and update the state. 773 */ 774 if (!nd6_try_set_entry_addr(ifp, ln, lladdr)) 775 goto freeit; 776 777 flush_holdchain = true; 778 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 779 if (is_solicited) 780 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 781 else 782 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 783 if ((ln->ln_router = is_router) != 0) { 784 /* 785 * This means a router's state has changed from 786 * non-reachable to probably reachable, and might 787 * affect the status of associated prefixes.. 788 */ 789 checklink = 1; 790 } 791 } else { 792 int llchange; 793 794 /* 795 * Check if the link-layer address has changed or not. 796 */ 797 if (lladdr == NULL) 798 llchange = 0; 799 else { 800 if (ln->la_flags & LLE_VALID) { 801 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 802 llchange = 1; 803 else 804 llchange = 0; 805 } else 806 llchange = 1; 807 } 808 809 /* 810 * This is VERY complex. Look at it with care. 811 * 812 * override solicit lladdr llchange action 813 * (L: record lladdr) 814 * 815 * 0 0 n -- (2c) 816 * 0 0 y n (2b) L 817 * 0 0 y y (1) REACHABLE->STALE 818 * 0 1 n -- (2c) *->REACHABLE 819 * 0 1 y n (2b) L *->REACHABLE 820 * 0 1 y y (1) REACHABLE->STALE 821 * 1 0 n -- (2a) 822 * 1 0 y n (2a) L 823 * 1 0 y y (2a) L *->STALE 824 * 1 1 n -- (2a) *->REACHABLE 825 * 1 1 y n (2a) L *->REACHABLE 826 * 1 1 y y (2a) L *->REACHABLE 827 */ 828 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 829 /* 830 * If state is REACHABLE, make it STALE. 831 * no other updates should be done. 832 */ 833 if (ln->ln_state == ND6_LLINFO_REACHABLE) 834 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 835 goto freeit; 836 } else if (is_override /* (2a) */ 837 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 838 || lladdr == NULL) { /* (2c) */ 839 /* 840 * Update link-local address, if any. 841 */ 842 if (lladdr != NULL) { 843 linkhdrsize = sizeof(linkhdr); 844 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 845 linkhdr, &linkhdrsize, &lladdr_off) != 0) 846 goto freeit; 847 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 848 linkhdrsize, lladdr_off) == 0) { 849 ln = NULL; 850 goto freeit; 851 } 852 EVENTHANDLER_INVOKE(lle_event, ln, 853 LLENTRY_RESOLVED); 854 } 855 856 /* 857 * If solicited, make the state REACHABLE. 858 * If not solicited and the link-layer address was 859 * changed, make it STALE. 860 */ 861 if (is_solicited) 862 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 863 else { 864 if (lladdr != NULL && llchange) 865 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 866 } 867 } 868 869 if (ln->ln_router && !is_router) { 870 /* 871 * The peer dropped the router flag. 872 * Remove the sender from the Default Router List and 873 * update the Destination Cache entries. 874 */ 875 struct ifnet *nd6_ifp; 876 877 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 878 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 879 (ND_IFINFO(nd6_ifp)->flags & 880 ND6_IFF_ACCEPT_RTADV) != 0) 881 /* 882 * Even if the neighbor is not in the default 883 * router list, the neighbor may be used as a 884 * next hop for some destinations (e.g. redirect 885 * case). So we must call rt6_flush explicitly. 886 */ 887 rt6_flush(&ip6->ip6_src, ifp); 888 } 889 ln->ln_router = is_router; 890 } 891 /* XXX - QL 892 * Does this matter? 893 * rt->rt_flags &= ~RTF_REJECT; 894 */ 895 ln->la_asked = 0; 896 if (ln->la_hold != NULL) 897 chain = nd6_grab_holdchain(ln); 898 freeit: 899 if (ln != NULL) 900 LLE_WUNLOCK(ln); 901 902 if (chain != NULL) 903 nd6_flush_holdchain(ifp, ln, chain); 904 if (flush_holdchain) 905 nd6_flush_children_holdchain(ifp, ln); 906 907 if (checklink) 908 pfxlist_onlink_check(); 909 910 m_freem(m); 911 return; 912 913 bad: 914 if (ln != NULL) 915 LLE_WUNLOCK(ln); 916 917 ICMP6STAT_INC(icp6s_badna); 918 m_freem(m); 919 } 920 921 /* 922 * Neighbor advertisement output handling. 923 * 924 * Based on RFC 2461 925 * 926 * the following items are not implemented yet: 927 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 928 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 929 * 930 * tlladdr - 1 if include target link-layer address 931 * sdl0 - sockaddr_dl (= proxy NA) or NULL 932 */ 933 static void 934 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 935 const struct in6_addr *taddr6, u_long flags, int tlladdr, 936 struct sockaddr *sdl0, u_int fibnum) 937 { 938 struct mbuf *m; 939 struct m_tag *mtag; 940 struct ip6_hdr *ip6; 941 struct nd_neighbor_advert *nd_na; 942 struct ip6_moptions im6o; 943 struct in6_addr daddr6, dst6, src6; 944 uint32_t scopeid; 945 946 NET_EPOCH_ASSERT(); 947 948 int icmp6len, maxlen, error; 949 caddr_t mac = NULL; 950 951 daddr6 = *daddr6_0; /* make a local copy for modification */ 952 953 /* estimate the size of message */ 954 maxlen = sizeof(*ip6) + sizeof(*nd_na); 955 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 956 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 957 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 958 __func__, max_linkhdr, maxlen, MCLBYTES)); 959 960 if (max_linkhdr + maxlen > MHLEN) 961 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 962 else 963 m = m_gethdr(M_NOWAIT, MT_DATA); 964 if (m == NULL) 965 return; 966 M_SETFIB(m, fibnum); 967 968 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 969 m->m_flags |= M_MCAST; 970 im6o.im6o_multicast_ifp = ifp; 971 im6o.im6o_multicast_hlim = 255; 972 im6o.im6o_multicast_loop = 0; 973 } 974 975 icmp6len = sizeof(*nd_na); 976 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 977 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 978 979 /* fill neighbor advertisement packet */ 980 ip6 = mtod(m, struct ip6_hdr *); 981 ip6->ip6_flow = 0; 982 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 983 ip6->ip6_vfc |= IPV6_VERSION; 984 ip6->ip6_nxt = IPPROTO_ICMPV6; 985 ip6->ip6_hlim = 255; 986 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 987 /* reply to DAD */ 988 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 989 daddr6.s6_addr16[1] = 0; 990 daddr6.s6_addr32[1] = 0; 991 daddr6.s6_addr32[2] = 0; 992 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 993 if (in6_setscope(&daddr6, ifp, NULL)) 994 goto bad; 995 996 flags &= ~ND_NA_FLAG_SOLICITED; 997 } 998 ip6->ip6_dst = daddr6; 999 1000 /* 1001 * Select a source whose scope is the same as that of the dest. 1002 */ 1003 in6_splitscope(&daddr6, &dst6, &scopeid); 1004 error = in6_selectsrc_addr(fibnum, &dst6, 1005 scopeid, ifp, &src6, NULL); 1006 if (error) { 1007 char ip6buf[INET6_ADDRSTRLEN]; 1008 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1009 "determined: dst=%s, error=%d\n", 1010 ip6_sprintf(ip6buf, &daddr6), error)); 1011 goto bad; 1012 } 1013 ip6->ip6_src = src6; 1014 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1015 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1016 nd_na->nd_na_code = 0; 1017 nd_na->nd_na_target = *taddr6; 1018 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1019 1020 /* 1021 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1022 * see nd6_ns_input() for details. 1023 * Basically, if NS packet is sent to unicast/anycast addr, 1024 * target lladdr option SHOULD NOT be included. 1025 */ 1026 if (tlladdr) { 1027 /* 1028 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1029 * lladdr in sdl0. If we are not proxying (sending NA for 1030 * my address) use lladdr configured for the interface. 1031 */ 1032 if (sdl0 == NULL) { 1033 if (ifp->if_carp) 1034 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1035 if (mac == NULL) 1036 mac = nd6_ifptomac(ifp); 1037 } else if (sdl0->sa_family == AF_LINK) { 1038 struct sockaddr_dl *sdl; 1039 sdl = (struct sockaddr_dl *)sdl0; 1040 if (sdl->sdl_alen == ifp->if_addrlen) 1041 mac = LLADDR(sdl); 1042 } 1043 } 1044 if (tlladdr && mac) { 1045 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1046 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1047 1048 /* roundup to 8 bytes alignment! */ 1049 optlen = (optlen + 7) & ~7; 1050 1051 m->m_pkthdr.len += optlen; 1052 m->m_len += optlen; 1053 icmp6len += optlen; 1054 bzero((caddr_t)nd_opt, optlen); 1055 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1056 nd_opt->nd_opt_len = optlen >> 3; 1057 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1058 } else 1059 flags &= ~ND_NA_FLAG_OVERRIDE; 1060 1061 ip6->ip6_plen = htons((u_short)icmp6len); 1062 nd_na->nd_na_flags_reserved = flags; 1063 nd_na->nd_na_cksum = 0; 1064 nd_na->nd_na_cksum = 1065 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1066 1067 if (send_sendso_input_hook != NULL) { 1068 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1069 sizeof(unsigned short), M_NOWAIT); 1070 if (mtag == NULL) 1071 goto bad; 1072 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1073 m_tag_prepend(m, mtag); 1074 } 1075 1076 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1077 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1078 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1079 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1080 1081 return; 1082 1083 bad: 1084 m_freem(m); 1085 } 1086 1087 #ifndef BURN_BRIDGES 1088 void 1089 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1090 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1091 struct sockaddr *sdl0) 1092 { 1093 1094 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1095 RT_DEFAULT_FIB); 1096 } 1097 #endif 1098 1099 caddr_t 1100 nd6_ifptomac(struct ifnet *ifp) 1101 { 1102 switch (ifp->if_type) { 1103 case IFT_ETHER: 1104 case IFT_IEEE1394: 1105 case IFT_L2VLAN: 1106 case IFT_INFINIBAND: 1107 case IFT_BRIDGE: 1108 return IF_LLADDR(ifp); 1109 default: 1110 return NULL; 1111 } 1112 } 1113 1114 struct dadq { 1115 TAILQ_ENTRY(dadq) dad_list; 1116 struct ifaddr *dad_ifa; 1117 int dad_count; /* max NS to send */ 1118 int dad_ns_tcount; /* # of trials to send NS */ 1119 int dad_ns_ocount; /* NS sent so far */ 1120 int dad_ns_icount; 1121 int dad_na_icount; 1122 int dad_ns_lcount; /* looped back NS */ 1123 int dad_loopbackprobe; /* probing state for loopback detection */ 1124 struct callout dad_timer_ch; 1125 struct vnet *dad_vnet; 1126 u_int dad_refcnt; 1127 #define ND_OPT_NONCE_LEN32 \ 1128 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1129 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1130 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */ 1131 }; 1132 1133 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq); 1134 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock); 1135 #define V_dadq VNET(dadq) 1136 #define V_dad_rwlock VNET(dad_rwlock) 1137 1138 #define DADQ_LOCKPTR() (&V_dad_rwlock) 1139 #define DADQ_LOCK_INIT() rw_init(DADQ_LOCKPTR(), "nd6 DAD queue") 1140 #define DADQ_RLOCK() rw_rlock(DADQ_LOCKPTR()) 1141 #define DADQ_RUNLOCK() rw_runlock(DADQ_LOCKPTR()) 1142 #define DADQ_WLOCK() rw_wlock(DADQ_LOCKPTR()) 1143 #define DADQ_WUNLOCK() rw_wunlock(DADQ_LOCKPTR()) 1144 1145 #define DADQ_LOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_LOCKED); 1146 #define DADQ_RLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_RLOCKED); 1147 #define DADQ_WLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_WLOCKED); 1148 1149 static void 1150 nd6_dad_add(struct dadq *dp) 1151 { 1152 DADQ_WLOCK_ASSERT(); 1153 1154 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1155 dp->dad_ondadq = true; 1156 } 1157 1158 static void 1159 nd6_dad_del(struct dadq *dp) 1160 { 1161 DADQ_WLOCK_ASSERT(); 1162 1163 if (dp->dad_ondadq) { 1164 /* 1165 * Remove dp from the dadq and release the dadq's 1166 * reference. 1167 */ 1168 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1169 dp->dad_ondadq = false; 1170 nd6_dad_rele(dp); 1171 } 1172 } 1173 1174 static struct dadq * 1175 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1176 { 1177 struct dadq *dp; 1178 1179 DADQ_LOCK_ASSERT(); 1180 1181 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1182 if (dp->dad_ifa != ifa) 1183 continue; 1184 1185 /* 1186 * Skip if the nonce matches the received one. 1187 * +2 in the length is required because of type and 1188 * length fields are included in a header. 1189 */ 1190 if (n != NULL && 1191 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1192 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1193 ND_OPT_NONCE_LEN) == 0) { 1194 dp->dad_ns_lcount++; 1195 continue; 1196 } 1197 break; 1198 } 1199 1200 return (dp); 1201 } 1202 1203 static void 1204 nd6_dad_starttimer(struct dadq *dp, int ticks) 1205 { 1206 DADQ_WLOCK_ASSERT(); 1207 1208 callout_reset(&dp->dad_timer_ch, ticks, nd6_dad_timer, dp); 1209 } 1210 1211 static void 1212 nd6_dad_stoptimer(struct dadq *dp) 1213 { 1214 callout_drain(&dp->dad_timer_ch); 1215 } 1216 1217 static void 1218 nd6_dad_rele(struct dadq *dp) 1219 { 1220 if (refcount_release(&dp->dad_refcnt)) { 1221 KASSERT(!dp->dad_ondadq, ("dp %p still on DAD queue", dp)); 1222 ifa_free(dp->dad_ifa); 1223 free(dp, M_IP6NDP); 1224 } 1225 } 1226 1227 void 1228 nd6_dad_init(void) 1229 { 1230 DADQ_LOCK_INIT(); 1231 TAILQ_INIT(&V_dadq); 1232 } 1233 1234 /* 1235 * Start Duplicate Address Detection (DAD) for specified interface address. 1236 */ 1237 void 1238 nd6_dad_start(struct ifaddr *ifa, int delay) 1239 { 1240 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1241 struct dadq *dp; 1242 char ip6buf[INET6_ADDRSTRLEN]; 1243 1244 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0, 1245 ("starting DAD on non-tentative address %p", ifa)); 1246 1247 /* 1248 * If we don't need DAD, don't do it. 1249 * There are several cases: 1250 * - DAD is disabled globally or on the interface 1251 * - the interface address is anycast 1252 */ 1253 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 || 1254 V_ip6_dad_count == 0 || 1255 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) != 0) { 1256 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1257 return; 1258 } 1259 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 || 1260 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || 1261 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) != 0) 1262 return; 1263 1264 DADQ_WLOCK(); 1265 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1266 /* 1267 * DAD is already in progress. Let the existing entry 1268 * finish it. 1269 */ 1270 DADQ_WUNLOCK(); 1271 return; 1272 } 1273 1274 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1275 if (dp == NULL) { 1276 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1277 "%s(%s)\n", 1278 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1279 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1280 return; 1281 } 1282 callout_init_rw(&dp->dad_timer_ch, DADQ_LOCKPTR(), 1283 CALLOUT_RETURNUNLOCKED); 1284 #ifdef VIMAGE 1285 dp->dad_vnet = curvnet; 1286 #endif 1287 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1288 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1289 1290 /* 1291 * Send NS packet for DAD, ip6_dad_count times. 1292 * Note that we must delay the first transmission, if this is the 1293 * first packet to be sent from the interface after interface 1294 * (re)initialization. 1295 */ 1296 dp->dad_ifa = ifa; 1297 ifa_ref(dp->dad_ifa); 1298 dp->dad_count = V_ip6_dad_count; 1299 dp->dad_ns_icount = dp->dad_na_icount = 0; 1300 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1301 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1302 1303 /* Add this to the dadq and add a reference for the dadq. */ 1304 refcount_init(&dp->dad_refcnt, 1); 1305 nd6_dad_add(dp); 1306 nd6_dad_starttimer(dp, delay); 1307 DADQ_WUNLOCK(); 1308 } 1309 1310 /* 1311 * terminate DAD unconditionally. used for address removals. 1312 */ 1313 void 1314 nd6_dad_stop(struct ifaddr *ifa) 1315 { 1316 struct dadq *dp; 1317 1318 DADQ_WLOCK(); 1319 dp = nd6_dad_find(ifa, NULL); 1320 if (dp == NULL) { 1321 DADQ_WUNLOCK(); 1322 /* DAD wasn't started yet */ 1323 return; 1324 } 1325 1326 /* 1327 * Acquire a temporary reference so that we can safely stop the callout. 1328 */ 1329 (void)refcount_acquire(&dp->dad_refcnt); 1330 nd6_dad_del(dp); 1331 DADQ_WUNLOCK(); 1332 1333 nd6_dad_stoptimer(dp); 1334 nd6_dad_rele(dp); 1335 } 1336 1337 static void 1338 nd6_dad_timer(void *arg) 1339 { 1340 struct dadq *dp = arg; 1341 struct ifaddr *ifa = dp->dad_ifa; 1342 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1343 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1344 char ip6buf[INET6_ADDRSTRLEN]; 1345 struct epoch_tracker et; 1346 1347 CURVNET_SET(dp->dad_vnet); 1348 KASSERT(ia != NULL, ("DAD entry %p with no address", dp)); 1349 1350 NET_EPOCH_ENTER(et); 1351 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1352 /* Do not need DAD for ifdisabled interface. */ 1353 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1354 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1355 goto err; 1356 } 1357 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1358 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1359 "%s(%s)\n", 1360 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1361 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1362 goto err; 1363 } 1364 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1365 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1366 "%s(%s)\n", 1367 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1368 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1369 goto err; 1370 } 1371 1372 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1373 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1374 (((ifp->if_flags & IFF_UP) == 0) || 1375 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1376 nd6log((LOG_INFO, "%s: could not run DAD " 1377 "because the interface was down or not running.\n", 1378 if_name(ifa->ifa_ifp))); 1379 goto err; 1380 } 1381 1382 /* Need more checks? */ 1383 if (dp->dad_ns_ocount < dp->dad_count) { 1384 /* 1385 * We have more NS to go. Send NS packet for DAD. 1386 */ 1387 nd6_dad_starttimer(dp, 1388 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1389 nd6_dad_ns_output(dp); 1390 goto done; 1391 } else { 1392 /* 1393 * We have transmitted sufficient number of DAD packets. 1394 * See what we've got. 1395 */ 1396 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) { 1397 /* We've seen NS or NA, means DAD has failed. */ 1398 nd6_dad_duplicated(ifa, dp); 1399 } else if (V_dad_enhanced != 0 && 1400 dp->dad_ns_lcount > 0 && 1401 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1402 /* 1403 * Sec. 4.1 in RFC 7527 requires transmission of 1404 * additional probes until the loopback condition 1405 * becomes clear when a looped back probe is detected. 1406 */ 1407 log(LOG_ERR, "%s: a looped back NS message is " 1408 "detected during DAD for %s. " 1409 "Another DAD probes are being sent.\n", 1410 if_name(ifa->ifa_ifp), 1411 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1412 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1413 /* 1414 * Send an NS immediately and increase dad_count by 1415 * V_nd6_mmaxtries - 1. 1416 */ 1417 dp->dad_count = 1418 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1419 nd6_dad_starttimer(dp, 1420 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1421 nd6_dad_ns_output(dp); 1422 goto done; 1423 } else { 1424 /* 1425 * We are done with DAD. No NA came, no NS came. 1426 * No duplicate address found. Check IFDISABLED flag 1427 * again in case that it is changed between the 1428 * beginning of this function and here. 1429 */ 1430 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1431 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1432 1433 nd6log((LOG_DEBUG, 1434 "%s: DAD complete for %s - no duplicates found\n", 1435 if_name(ifa->ifa_ifp), 1436 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1437 if (dp->dad_ns_lcount > 0) 1438 log(LOG_ERR, "%s: DAD completed while " 1439 "a looped back NS message is detected " 1440 "during DAD for %s.\n", 1441 if_name(ifa->ifa_ifp), 1442 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1443 } 1444 } 1445 err: 1446 nd6_dad_del(dp); 1447 DADQ_WUNLOCK(); 1448 done: 1449 NET_EPOCH_EXIT(et); 1450 CURVNET_RESTORE(); 1451 } 1452 1453 static void 1454 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1455 { 1456 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1457 struct ifnet *ifp; 1458 char ip6buf[INET6_ADDRSTRLEN]; 1459 1460 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1461 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1462 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1463 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1464 dp->dad_na_icount); 1465 1466 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1467 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1468 1469 ifp = ifa->ifa_ifp; 1470 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1471 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1472 log(LOG_ERR, "%s: manual intervention required\n", 1473 if_name(ifp)); 1474 1475 /* 1476 * If the address is a link-local address formed from an interface 1477 * identifier based on the hardware address which is supposed to be 1478 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1479 * operation on the interface SHOULD be disabled. 1480 * [RFC 4862, Section 5.4.5] 1481 */ 1482 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1483 struct in6_addr in6; 1484 1485 /* 1486 * To avoid over-reaction, we only apply this logic when we are 1487 * very sure that hardware addresses are supposed to be unique. 1488 */ 1489 switch (ifp->if_type) { 1490 case IFT_ETHER: 1491 case IFT_ATM: 1492 case IFT_IEEE1394: 1493 case IFT_INFINIBAND: 1494 in6 = ia->ia_addr.sin6_addr; 1495 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1496 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1497 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1498 log(LOG_ERR, "%s: possible hardware address " 1499 "duplication detected, disable IPv6\n", 1500 if_name(ifp)); 1501 } 1502 break; 1503 } 1504 } 1505 } 1506 1507 /* 1508 * Transmit a neighbour solicitation for the purpose of DAD. Returns with the 1509 * DAD queue unlocked. 1510 */ 1511 static void 1512 nd6_dad_ns_output(struct dadq *dp) 1513 { 1514 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1515 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1516 int i; 1517 1518 DADQ_WLOCK_ASSERT(); 1519 1520 dp->dad_ns_tcount++; 1521 if ((ifp->if_flags & IFF_UP) == 0) { 1522 DADQ_WUNLOCK(); 1523 return; 1524 } 1525 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1526 DADQ_WUNLOCK(); 1527 return; 1528 } 1529 1530 dp->dad_ns_ocount++; 1531 if (V_dad_enhanced != 0) { 1532 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1533 dp->dad_nonce[i] = arc4random(); 1534 /* 1535 * XXXHRS: Note that in the case that 1536 * DupAddrDetectTransmits > 1, multiple NS messages with 1537 * different nonces can be looped back in an unexpected 1538 * order. The current implementation recognizes only 1539 * the latest nonce on the sender side. Practically it 1540 * should work well in almost all cases. 1541 */ 1542 } 1543 DADQ_WUNLOCK(); 1544 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1545 (uint8_t *)&dp->dad_nonce[0]); 1546 } 1547 1548 static void 1549 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1550 { 1551 struct dadq *dp; 1552 1553 if (ifa == NULL) 1554 panic("ifa == NULL in nd6_dad_ns_input"); 1555 1556 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1557 if (V_dad_enhanced == 0) 1558 ndopt_nonce = NULL; 1559 DADQ_RLOCK(); 1560 dp = nd6_dad_find(ifa, ndopt_nonce); 1561 if (dp != NULL) 1562 dp->dad_ns_icount++; 1563 DADQ_RUNLOCK(); 1564 } 1565 1566 static void 1567 nd6_dad_na_input(struct ifaddr *ifa) 1568 { 1569 struct dadq *dp; 1570 1571 if (ifa == NULL) 1572 panic("ifa == NULL in nd6_dad_na_input"); 1573 1574 DADQ_RLOCK(); 1575 dp = nd6_dad_find(ifa, NULL); 1576 if (dp != NULL) 1577 dp->dad_na_icount++; 1578 DADQ_RUNLOCK(); 1579 }
Cache object: 9a67d1e1b3a7502e1583e8d20cdcb217
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