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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, int); 88 static void nd6_dad_stoptimer(struct dadq *); 89 static void nd6_dad_timer(struct dadq *); 90 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *); 91 static void nd6_dad_ns_output(struct dadq *); 92 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *); 93 static void nd6_dad_na_input(struct ifaddr *); 94 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 95 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 96 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *, 97 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int); 98 99 VNET_DEFINE_STATIC(int, dad_enhanced) = 1; 100 #define V_dad_enhanced VNET(dad_enhanced) 101 102 SYSCTL_DECL(_net_inet6_ip6); 103 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW, 104 &VNET_NAME(dad_enhanced), 0, 105 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD."); 106 107 VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to 108 transmit DAD packet */ 109 #define V_dad_maxtry VNET(dad_maxtry) 110 111 /* 112 * Input a Neighbor Solicitation Message. 113 * 114 * Based on RFC 2461 115 * Based on RFC 2462 (duplicate address detection) 116 */ 117 void 118 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 119 { 120 struct ifnet *ifp; 121 struct ip6_hdr *ip6; 122 struct nd_neighbor_solicit *nd_ns; 123 struct in6_addr daddr6, myaddr6, saddr6, taddr6; 124 struct ifaddr *ifa; 125 struct sockaddr_dl proxydl; 126 union nd_opts ndopts; 127 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 128 char *lladdr; 129 int anycast, lladdrlen, proxy, rflag, tentative, tlladdr; 130 131 ifa = NULL; 132 133 /* RFC 6980: Nodes MUST silently ignore fragments */ 134 if(m->m_flags & M_FRAGMENTED) 135 goto freeit; 136 137 ifp = m->m_pkthdr.rcvif; 138 ip6 = mtod(m, struct ip6_hdr *); 139 if (__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 if (IN6_IS_ADDR_MULTICAST(taddr6)) 417 return; 418 419 /* estimate the size of message */ 420 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 421 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 422 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 423 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 424 __func__, max_linkhdr, maxlen, MCLBYTES)); 425 426 if (max_linkhdr + maxlen > MHLEN) 427 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 428 else 429 m = m_gethdr(M_NOWAIT, MT_DATA); 430 if (m == NULL) 431 return; 432 M_SETFIB(m, fibnum); 433 434 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 435 m->m_flags |= M_MCAST; 436 im6o.im6o_multicast_ifp = ifp; 437 im6o.im6o_multicast_hlim = 255; 438 im6o.im6o_multicast_loop = 0; 439 } 440 441 icmp6len = sizeof(*nd_ns); 442 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 443 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 444 445 /* fill neighbor solicitation packet */ 446 ip6 = mtod(m, struct ip6_hdr *); 447 ip6->ip6_flow = 0; 448 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 449 ip6->ip6_vfc |= IPV6_VERSION; 450 /* ip6->ip6_plen will be set later */ 451 ip6->ip6_nxt = IPPROTO_ICMPV6; 452 ip6->ip6_hlim = 255; 453 if (daddr6) 454 ip6->ip6_dst = *daddr6; 455 else { 456 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 457 ip6->ip6_dst.s6_addr16[1] = 0; 458 ip6->ip6_dst.s6_addr32[1] = 0; 459 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 460 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 461 ip6->ip6_dst.s6_addr8[12] = 0xff; 462 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 463 goto bad; 464 } 465 if (nonce == NULL) { 466 struct ifaddr *ifa = NULL; 467 468 /* 469 * RFC2461 7.2.2: 470 * "If the source address of the packet prompting the 471 * solicitation is the same as one of the addresses assigned 472 * to the outgoing interface, that address SHOULD be placed 473 * in the IP Source Address of the outgoing solicitation. 474 * Otherwise, any one of the addresses assigned to the 475 * interface should be used." 476 * 477 * We use the source address for the prompting packet 478 * (saddr6), if saddr6 belongs to the outgoing interface. 479 * Otherwise, we perform the source address selection as usual. 480 */ 481 482 if (saddr6 != NULL) 483 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 484 if (ifa != NULL) { 485 /* ip6_src set already. */ 486 ip6->ip6_src = *saddr6; 487 ifa_free(ifa); 488 } else { 489 int error; 490 struct in6_addr dst6, src6; 491 uint32_t scopeid; 492 493 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); 494 error = in6_selectsrc_addr(fibnum, &dst6, 495 scopeid, ifp, &src6, NULL); 496 if (error) { 497 char ip6buf[INET6_ADDRSTRLEN]; 498 nd6log((LOG_DEBUG, "%s: source can't be " 499 "determined: dst=%s, error=%d\n", __func__, 500 ip6_sprintf(ip6buf, &dst6), 501 error)); 502 goto bad; 503 } 504 ip6->ip6_src = src6; 505 } 506 } else { 507 /* 508 * Source address for DAD packet must always be IPv6 509 * unspecified address. (0::0) 510 * We actually don't have to 0-clear the address (we did it 511 * above), but we do so here explicitly to make the intention 512 * clearer. 513 */ 514 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 515 } 516 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 517 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 518 nd_ns->nd_ns_code = 0; 519 nd_ns->nd_ns_reserved = 0; 520 nd_ns->nd_ns_target = *taddr6; 521 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 522 523 /* 524 * Add source link-layer address option. 525 * 526 * spec implementation 527 * --- --- 528 * DAD packet MUST NOT do not add the option 529 * there's no link layer address: 530 * impossible do not add the option 531 * there's link layer address: 532 * Multicast NS MUST add one add the option 533 * Unicast NS SHOULD add one add the option 534 */ 535 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 536 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 537 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 538 /* 8 byte alignments... */ 539 optlen = (optlen + 7) & ~7; 540 541 m->m_pkthdr.len += optlen; 542 m->m_len += optlen; 543 icmp6len += optlen; 544 bzero((caddr_t)nd_opt, optlen); 545 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 546 nd_opt->nd_opt_len = optlen >> 3; 547 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 548 } 549 /* 550 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 551 * This behavior is documented as Enhanced Duplicate Address 552 * Detection in RFC 7527. 553 * net.inet6.ip6.dad_enhanced=0 disables this. 554 */ 555 if (V_dad_enhanced != 0 && nonce != NULL) { 556 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 557 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 558 /* 8-byte alignment is required. */ 559 optlen = (optlen + 7) & ~7; 560 561 m->m_pkthdr.len += optlen; 562 m->m_len += optlen; 563 icmp6len += optlen; 564 bzero((caddr_t)nd_opt, optlen); 565 nd_opt->nd_opt_type = ND_OPT_NONCE; 566 nd_opt->nd_opt_len = optlen >> 3; 567 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 568 } 569 ip6->ip6_plen = htons((u_short)icmp6len); 570 nd_ns->nd_ns_cksum = 0; 571 nd_ns->nd_ns_cksum = 572 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 573 574 if (send_sendso_input_hook != NULL) { 575 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 576 sizeof(unsigned short), M_NOWAIT); 577 if (mtag == NULL) 578 goto bad; 579 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 580 m_tag_prepend(m, mtag); 581 } 582 583 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 584 &im6o, NULL, NULL); 585 icmp6_ifstat_inc(ifp, ifs6_out_msg); 586 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 587 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 588 589 return; 590 591 bad: 592 m_freem(m); 593 } 594 595 #ifndef BURN_BRIDGES 596 void 597 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 598 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 599 { 600 601 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 602 } 603 #endif 604 /* 605 * Neighbor advertisement input handling. 606 * 607 * Based on RFC 2461 608 * Based on RFC 2462 (duplicate address detection) 609 * 610 * the following items are not implemented yet: 611 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 612 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 613 */ 614 void 615 nd6_na_input(struct mbuf *m, int off, int icmp6len) 616 { 617 struct ifnet *ifp; 618 struct ip6_hdr *ip6; 619 struct ifaddr *ifa; 620 struct llentry *ln; 621 struct mbuf *chain; 622 struct nd_neighbor_advert *nd_na; 623 struct in6_addr daddr6, taddr6; 624 struct sockaddr_in6 sin6; 625 union nd_opts ndopts; 626 u_char linkhdr[LLE_MAX_LINKHDR]; 627 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 628 char *lladdr; 629 size_t linkhdrsize; 630 int flags, is_override, is_router, is_solicited; 631 int lladdr_off, lladdrlen, checklink; 632 633 NET_EPOCH_ASSERT(); 634 635 chain = NULL; 636 ln = NULL; 637 checklink = 0; 638 639 /* RFC 6980: Nodes MUST silently ignore fragments */ 640 if(m->m_flags & M_FRAGMENTED) 641 goto freeit; 642 643 ifp = m->m_pkthdr.rcvif; 644 ip6 = mtod(m, struct ip6_hdr *); 645 if (__predict_false(ip6->ip6_hlim != 255)) { 646 ICMP6STAT_INC(icp6s_invlhlim); 647 nd6log((LOG_ERR, 648 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 649 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 650 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 651 goto bad; 652 } 653 654 if (m->m_len < off + icmp6len) { 655 m = m_pullup(m, off + icmp6len); 656 if (m == NULL) { 657 IP6STAT_INC(ip6s_exthdrtoolong); 658 return; 659 } 660 } 661 ip6 = mtod(m, struct ip6_hdr *); 662 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 663 664 flags = nd_na->nd_na_flags_reserved; 665 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 666 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 667 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 668 669 taddr6 = nd_na->nd_na_target; 670 if (in6_setscope(&taddr6, ifp, NULL)) 671 goto bad; /* XXX: impossible */ 672 673 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 674 nd6log((LOG_ERR, 675 "nd6_na_input: invalid target address %s\n", 676 ip6_sprintf(ip6bufs, &taddr6))); 677 goto bad; 678 } 679 680 daddr6 = ip6->ip6_dst; 681 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 682 if (is_solicited) { 683 nd6log((LOG_ERR, 684 "nd6_na_input: a solicited adv is multicasted\n")); 685 goto bad; 686 } 687 688 icmp6len -= sizeof(*nd_na); 689 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 690 if (nd6_options(&ndopts) < 0) { 691 nd6log((LOG_INFO, 692 "nd6_na_input: invalid ND option, ignored\n")); 693 /* nd6_options have incremented stats */ 694 goto freeit; 695 } 696 697 lladdr = NULL; 698 lladdrlen = 0; 699 if (ndopts.nd_opts_tgt_lladdr) { 700 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 701 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 702 } 703 704 /* 705 * This effectively disables the DAD check on a non-master CARP 706 * address. 707 */ 708 if (ifp->if_carp) 709 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 710 else 711 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 712 713 /* 714 * Target address matches one of my interface address. 715 * 716 * If my address is tentative, this means that there's somebody 717 * already using the same address as mine. This indicates DAD failure. 718 * This is defined in RFC 2462. 719 * 720 * Otherwise, process as defined in RFC 2461. 721 */ 722 if (ifa 723 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 724 nd6_dad_na_input(ifa); 725 ifa_free(ifa); 726 goto freeit; 727 } 728 729 /* Just for safety, maybe unnecessary. */ 730 if (ifa) { 731 ifa_free(ifa); 732 log(LOG_ERR, 733 "nd6_na_input: duplicate IP6 address %s\n", 734 ip6_sprintf(ip6bufs, &taddr6)); 735 goto freeit; 736 } 737 738 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 739 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 740 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 741 ifp->if_addrlen, lladdrlen - 2)); 742 goto bad; 743 } 744 745 /* 746 * If no neighbor cache entry is found, NA SHOULD silently be 747 * discarded. 748 */ 749 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 750 if (ln == NULL) { 751 goto freeit; 752 } 753 754 /* 755 * Do not try to override static entry. 756 */ 757 if (ln->la_flags & LLE_STATIC) 758 goto freeit; 759 760 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 761 /* 762 * If the link-layer has address, and no lladdr option came, 763 * discard the packet. 764 */ 765 if (ifp->if_addrlen && lladdr == NULL) { 766 goto freeit; 767 } 768 769 /* 770 * Record link-layer address, and update the state. 771 */ 772 linkhdrsize = sizeof(linkhdr); 773 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 774 linkhdr, &linkhdrsize, &lladdr_off) != 0) 775 return; 776 777 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize, 778 lladdr_off) == 0) { 779 ln = NULL; 780 goto freeit; 781 } 782 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 783 if (is_solicited) 784 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 785 else 786 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 787 if ((ln->ln_router = is_router) != 0) { 788 /* 789 * This means a router's state has changed from 790 * non-reachable to probably reachable, and might 791 * affect the status of associated prefixes.. 792 */ 793 checklink = 1; 794 } 795 } else { 796 int llchange; 797 798 /* 799 * Check if the link-layer address has changed or not. 800 */ 801 if (lladdr == NULL) 802 llchange = 0; 803 else { 804 if (ln->la_flags & LLE_VALID) { 805 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 806 llchange = 1; 807 else 808 llchange = 0; 809 } else 810 llchange = 1; 811 } 812 813 /* 814 * This is VERY complex. Look at it with care. 815 * 816 * override solicit lladdr llchange action 817 * (L: record lladdr) 818 * 819 * 0 0 n -- (2c) 820 * 0 0 y n (2b) L 821 * 0 0 y y (1) REACHABLE->STALE 822 * 0 1 n -- (2c) *->REACHABLE 823 * 0 1 y n (2b) L *->REACHABLE 824 * 0 1 y y (1) REACHABLE->STALE 825 * 1 0 n -- (2a) 826 * 1 0 y n (2a) L 827 * 1 0 y y (2a) L *->STALE 828 * 1 1 n -- (2a) *->REACHABLE 829 * 1 1 y n (2a) L *->REACHABLE 830 * 1 1 y y (2a) L *->REACHABLE 831 */ 832 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 833 /* 834 * If state is REACHABLE, make it STALE. 835 * no other updates should be done. 836 */ 837 if (ln->ln_state == ND6_LLINFO_REACHABLE) 838 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 839 goto freeit; 840 } else if (is_override /* (2a) */ 841 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 842 || lladdr == NULL) { /* (2c) */ 843 /* 844 * Update link-local address, if any. 845 */ 846 if (lladdr != NULL) { 847 linkhdrsize = sizeof(linkhdr); 848 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 849 linkhdr, &linkhdrsize, &lladdr_off) != 0) 850 goto freeit; 851 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 852 linkhdrsize, lladdr_off) == 0) { 853 ln = NULL; 854 goto freeit; 855 } 856 EVENTHANDLER_INVOKE(lle_event, ln, 857 LLENTRY_RESOLVED); 858 } 859 860 /* 861 * If solicited, make the state REACHABLE. 862 * If not solicited and the link-layer address was 863 * changed, make it STALE. 864 */ 865 if (is_solicited) 866 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 867 else { 868 if (lladdr != NULL && llchange) 869 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 870 } 871 } 872 873 if (ln->ln_router && !is_router) { 874 /* 875 * The peer dropped the router flag. 876 * Remove the sender from the Default Router List and 877 * update the Destination Cache entries. 878 */ 879 struct ifnet *nd6_ifp; 880 881 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 882 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 883 (ND_IFINFO(nd6_ifp)->flags & 884 ND6_IFF_ACCEPT_RTADV) != 0) 885 /* 886 * Even if the neighbor is not in the default 887 * router list, the neighbor may be used as a 888 * next hop for some destinations (e.g. redirect 889 * case). So we must call rt6_flush explicitly. 890 */ 891 rt6_flush(&ip6->ip6_src, ifp); 892 } 893 ln->ln_router = is_router; 894 } 895 /* XXX - QL 896 * Does this matter? 897 * rt->rt_flags &= ~RTF_REJECT; 898 */ 899 ln->la_asked = 0; 900 if (ln->la_hold != NULL) { 901 memset(&sin6, 0, sizeof(sin6)); 902 nd6_grab_holdchain(ln, &chain, &sin6); 903 } 904 freeit: 905 if (ln != NULL) 906 LLE_WUNLOCK(ln); 907 908 if (chain != NULL) 909 nd6_flush_holdchain(ifp, chain, &sin6); 910 911 if (checklink) 912 pfxlist_onlink_check(); 913 914 m_freem(m); 915 return; 916 917 bad: 918 if (ln != NULL) 919 LLE_WUNLOCK(ln); 920 921 ICMP6STAT_INC(icp6s_badna); 922 m_freem(m); 923 } 924 925 /* 926 * Neighbor advertisement output handling. 927 * 928 * Based on RFC 2461 929 * 930 * the following items are not implemented yet: 931 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 932 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 933 * 934 * tlladdr - 1 if include target link-layer address 935 * sdl0 - sockaddr_dl (= proxy NA) or NULL 936 */ 937 static void 938 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 939 const struct in6_addr *taddr6, u_long flags, int tlladdr, 940 struct sockaddr *sdl0, u_int fibnum) 941 { 942 struct mbuf *m; 943 struct m_tag *mtag; 944 struct ip6_hdr *ip6; 945 struct nd_neighbor_advert *nd_na; 946 struct ip6_moptions im6o; 947 struct in6_addr daddr6, dst6, src6; 948 uint32_t scopeid; 949 950 int icmp6len, maxlen, error; 951 caddr_t mac = NULL; 952 953 daddr6 = *daddr6_0; /* make a local copy for modification */ 954 955 /* estimate the size of message */ 956 maxlen = sizeof(*ip6) + sizeof(*nd_na); 957 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 958 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 959 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 960 __func__, max_linkhdr, maxlen, MCLBYTES)); 961 962 if (max_linkhdr + maxlen > MHLEN) 963 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 964 else 965 m = m_gethdr(M_NOWAIT, MT_DATA); 966 if (m == NULL) 967 return; 968 M_SETFIB(m, fibnum); 969 970 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 971 m->m_flags |= M_MCAST; 972 im6o.im6o_multicast_ifp = ifp; 973 im6o.im6o_multicast_hlim = 255; 974 im6o.im6o_multicast_loop = 0; 975 } 976 977 icmp6len = sizeof(*nd_na); 978 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 979 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 980 981 /* fill neighbor advertisement packet */ 982 ip6 = mtod(m, struct ip6_hdr *); 983 ip6->ip6_flow = 0; 984 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 985 ip6->ip6_vfc |= IPV6_VERSION; 986 ip6->ip6_nxt = IPPROTO_ICMPV6; 987 ip6->ip6_hlim = 255; 988 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 989 /* reply to DAD */ 990 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 991 daddr6.s6_addr16[1] = 0; 992 daddr6.s6_addr32[1] = 0; 993 daddr6.s6_addr32[2] = 0; 994 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 995 if (in6_setscope(&daddr6, ifp, NULL)) 996 goto bad; 997 998 flags &= ~ND_NA_FLAG_SOLICITED; 999 } 1000 ip6->ip6_dst = daddr6; 1001 1002 /* 1003 * Select a source whose scope is the same as that of the dest. 1004 */ 1005 in6_splitscope(&daddr6, &dst6, &scopeid); 1006 error = in6_selectsrc_addr(fibnum, &dst6, 1007 scopeid, ifp, &src6, NULL); 1008 if (error) { 1009 char ip6buf[INET6_ADDRSTRLEN]; 1010 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1011 "determined: dst=%s, error=%d\n", 1012 ip6_sprintf(ip6buf, &daddr6), error)); 1013 goto bad; 1014 } 1015 ip6->ip6_src = src6; 1016 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1017 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1018 nd_na->nd_na_code = 0; 1019 nd_na->nd_na_target = *taddr6; 1020 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1021 1022 /* 1023 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1024 * see nd6_ns_input() for details. 1025 * Basically, if NS packet is sent to unicast/anycast addr, 1026 * target lladdr option SHOULD NOT be included. 1027 */ 1028 if (tlladdr) { 1029 /* 1030 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1031 * lladdr in sdl0. If we are not proxying (sending NA for 1032 * my address) use lladdr configured for the interface. 1033 */ 1034 if (sdl0 == NULL) { 1035 if (ifp->if_carp) 1036 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1037 if (mac == NULL) 1038 mac = nd6_ifptomac(ifp); 1039 } else if (sdl0->sa_family == AF_LINK) { 1040 struct sockaddr_dl *sdl; 1041 sdl = (struct sockaddr_dl *)sdl0; 1042 if (sdl->sdl_alen == ifp->if_addrlen) 1043 mac = LLADDR(sdl); 1044 } 1045 } 1046 if (tlladdr && mac) { 1047 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1048 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1049 1050 /* roundup to 8 bytes alignment! */ 1051 optlen = (optlen + 7) & ~7; 1052 1053 m->m_pkthdr.len += optlen; 1054 m->m_len += optlen; 1055 icmp6len += optlen; 1056 bzero((caddr_t)nd_opt, optlen); 1057 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1058 nd_opt->nd_opt_len = optlen >> 3; 1059 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1060 } else 1061 flags &= ~ND_NA_FLAG_OVERRIDE; 1062 1063 ip6->ip6_plen = htons((u_short)icmp6len); 1064 nd_na->nd_na_flags_reserved = flags; 1065 nd_na->nd_na_cksum = 0; 1066 nd_na->nd_na_cksum = 1067 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1068 1069 if (send_sendso_input_hook != NULL) { 1070 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1071 sizeof(unsigned short), M_NOWAIT); 1072 if (mtag == NULL) 1073 goto bad; 1074 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1075 m_tag_prepend(m, mtag); 1076 } 1077 1078 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1079 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1080 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1081 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1082 1083 return; 1084 1085 bad: 1086 m_freem(m); 1087 } 1088 1089 #ifndef BURN_BRIDGES 1090 void 1091 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1092 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1093 struct sockaddr *sdl0) 1094 { 1095 1096 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1097 RT_DEFAULT_FIB); 1098 } 1099 #endif 1100 1101 caddr_t 1102 nd6_ifptomac(struct ifnet *ifp) 1103 { 1104 switch (ifp->if_type) { 1105 case IFT_ETHER: 1106 case IFT_IEEE1394: 1107 case IFT_L2VLAN: 1108 case IFT_INFINIBAND: 1109 case IFT_BRIDGE: 1110 return IF_LLADDR(ifp); 1111 default: 1112 return NULL; 1113 } 1114 } 1115 1116 struct dadq { 1117 TAILQ_ENTRY(dadq) dad_list; 1118 struct ifaddr *dad_ifa; 1119 int dad_count; /* max NS to send */ 1120 int dad_ns_tcount; /* # of trials to send NS */ 1121 int dad_ns_ocount; /* NS sent so far */ 1122 int dad_ns_icount; 1123 int dad_na_icount; 1124 int dad_ns_lcount; /* looped back NS */ 1125 int dad_loopbackprobe; /* probing state for loopback detection */ 1126 struct callout dad_timer_ch; 1127 struct vnet *dad_vnet; 1128 u_int dad_refcnt; 1129 #define ND_OPT_NONCE_LEN32 \ 1130 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1131 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1132 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */ 1133 }; 1134 1135 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq); 1136 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock); 1137 #define V_dadq VNET(dadq) 1138 #define V_dad_rwlock VNET(dad_rwlock) 1139 1140 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1141 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1142 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1143 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1144 1145 static void 1146 nd6_dad_add(struct dadq *dp) 1147 { 1148 1149 DADQ_WLOCK(); 1150 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1151 dp->dad_ondadq = true; 1152 DADQ_WUNLOCK(); 1153 } 1154 1155 static void 1156 nd6_dad_del(struct dadq *dp) 1157 { 1158 1159 DADQ_WLOCK(); 1160 if (dp->dad_ondadq) { 1161 /* 1162 * Remove dp from the dadq and release the dadq's 1163 * reference. 1164 */ 1165 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1166 dp->dad_ondadq = false; 1167 DADQ_WUNLOCK(); 1168 nd6_dad_rele(dp); 1169 } else 1170 DADQ_WUNLOCK(); 1171 } 1172 1173 static struct dadq * 1174 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1175 { 1176 struct dadq *dp; 1177 1178 DADQ_RLOCK(); 1179 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1180 if (dp->dad_ifa != ifa) 1181 continue; 1182 /* 1183 * Skip if the nonce matches the received one. 1184 * +2 in the length is required because of type and 1185 * length fields are included in a header. 1186 */ 1187 if (n != NULL && 1188 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1189 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1190 ND_OPT_NONCE_LEN) == 0) { 1191 dp->dad_ns_lcount++; 1192 continue; 1193 } 1194 refcount_acquire(&dp->dad_refcnt); 1195 break; 1196 } 1197 DADQ_RUNLOCK(); 1198 1199 return (dp); 1200 } 1201 1202 static void 1203 nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns) 1204 { 1205 1206 NET_EPOCH_ASSERT(); 1207 1208 if (send_ns != 0) 1209 nd6_dad_ns_output(dp); 1210 callout_reset(&dp->dad_timer_ch, ticks, 1211 (void (*)(void *))nd6_dad_timer, (void *)dp); 1212 } 1213 1214 static void 1215 nd6_dad_stoptimer(struct dadq *dp) 1216 { 1217 1218 callout_drain(&dp->dad_timer_ch); 1219 } 1220 1221 static void 1222 nd6_dad_rele(struct dadq *dp) 1223 { 1224 1225 if (refcount_release(&dp->dad_refcnt)) { 1226 ifa_free(dp->dad_ifa); 1227 free(dp, M_IP6NDP); 1228 } 1229 } 1230 1231 void 1232 nd6_dad_init(void) 1233 { 1234 1235 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1236 TAILQ_INIT(&V_dadq); 1237 } 1238 1239 /* 1240 * Start Duplicate Address Detection (DAD) for specified interface address. 1241 */ 1242 void 1243 nd6_dad_start(struct ifaddr *ifa, int delay) 1244 { 1245 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1246 struct dadq *dp; 1247 char ip6buf[INET6_ADDRSTRLEN]; 1248 struct epoch_tracker et; 1249 1250 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0, 1251 ("starting DAD on non-tentative address %p", ifa)); 1252 1253 /* 1254 * If we don't need DAD, don't do it. 1255 * There are several cases: 1256 * - DAD is disabled globally or on the interface 1257 * - the interface address is anycast 1258 */ 1259 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 || 1260 V_ip6_dad_count == 0 || 1261 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) != 0) { 1262 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1263 return; 1264 } 1265 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 || 1266 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || 1267 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) != 0) 1268 return; 1269 1270 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1271 /* 1272 * DAD is already in progress. Let the existing entry 1273 * finish it. 1274 */ 1275 nd6_dad_rele(dp); 1276 return; 1277 } 1278 1279 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1280 if (dp == NULL) { 1281 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1282 "%s(%s)\n", 1283 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1284 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1285 return; 1286 } 1287 callout_init(&dp->dad_timer_ch, 0); 1288 #ifdef VIMAGE 1289 dp->dad_vnet = curvnet; 1290 #endif 1291 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1292 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1293 1294 /* 1295 * Send NS packet for DAD, ip6_dad_count times. 1296 * Note that we must delay the first transmission, if this is the 1297 * first packet to be sent from the interface after interface 1298 * (re)initialization. 1299 */ 1300 dp->dad_ifa = ifa; 1301 ifa_ref(dp->dad_ifa); 1302 dp->dad_count = V_ip6_dad_count; 1303 dp->dad_ns_icount = dp->dad_na_icount = 0; 1304 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1305 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1306 1307 /* Add this to the dadq and add a reference for the dadq. */ 1308 refcount_init(&dp->dad_refcnt, 1); 1309 nd6_dad_add(dp); 1310 NET_EPOCH_ENTER(et); 1311 nd6_dad_starttimer(dp, delay, 0); 1312 NET_EPOCH_EXIT(et); 1313 } 1314 1315 /* 1316 * terminate DAD unconditionally. used for address removals. 1317 */ 1318 void 1319 nd6_dad_stop(struct ifaddr *ifa) 1320 { 1321 struct dadq *dp; 1322 1323 dp = nd6_dad_find(ifa, NULL); 1324 if (!dp) { 1325 /* DAD wasn't started yet */ 1326 return; 1327 } 1328 1329 nd6_dad_stoptimer(dp); 1330 nd6_dad_del(dp); 1331 1332 /* Release this function's reference, acquired by nd6_dad_find(). */ 1333 nd6_dad_rele(dp); 1334 } 1335 1336 static void 1337 nd6_dad_timer(struct dadq *dp) 1338 { 1339 CURVNET_SET(dp->dad_vnet); 1340 struct ifaddr *ifa = dp->dad_ifa; 1341 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1342 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1343 char ip6buf[INET6_ADDRSTRLEN]; 1344 struct epoch_tracker et; 1345 1346 KASSERT(ia != NULL, ("DAD entry %p with no address", dp)); 1347 1348 NET_EPOCH_ENTER(et); 1349 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1350 /* Do not need DAD for ifdisabled interface. */ 1351 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1352 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1353 goto err; 1354 } 1355 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1356 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1357 "%s(%s)\n", 1358 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1359 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1360 goto err; 1361 } 1362 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1363 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1364 "%s(%s)\n", 1365 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1366 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1367 goto err; 1368 } 1369 1370 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1371 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1372 (((ifp->if_flags & IFF_UP) == 0) || 1373 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1374 nd6log((LOG_INFO, "%s: could not run DAD " 1375 "because the interface was down or not running.\n", 1376 if_name(ifa->ifa_ifp))); 1377 goto err; 1378 } 1379 1380 /* Need more checks? */ 1381 if (dp->dad_ns_ocount < dp->dad_count) { 1382 /* 1383 * We have more NS to go. Send NS packet for DAD. 1384 */ 1385 nd6_dad_starttimer(dp, 1386 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1); 1387 goto done; 1388 } else { 1389 /* 1390 * We have transmitted sufficient number of DAD packets. 1391 * See what we've got. 1392 */ 1393 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1394 /* We've seen NS or NA, means DAD has failed. */ 1395 nd6_dad_duplicated(ifa, dp); 1396 else if (V_dad_enhanced != 0 && 1397 dp->dad_ns_lcount > 0 && 1398 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1399 /* 1400 * Sec. 4.1 in RFC 7527 requires transmission of 1401 * additional probes until the loopback condition 1402 * becomes clear when a looped back probe is detected. 1403 */ 1404 log(LOG_ERR, "%s: a looped back NS message is " 1405 "detected during DAD for %s. " 1406 "Another DAD probes are being sent.\n", 1407 if_name(ifa->ifa_ifp), 1408 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1409 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1410 /* 1411 * Send an NS immediately and increase dad_count by 1412 * V_nd6_mmaxtries - 1. 1413 */ 1414 dp->dad_count = 1415 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1416 nd6_dad_starttimer(dp, 1417 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1418 1); 1419 goto done; 1420 } else { 1421 /* 1422 * We are done with DAD. No NA came, no NS came. 1423 * No duplicate address found. Check IFDISABLED flag 1424 * again in case that it is changed between the 1425 * beginning of this function and here. 1426 */ 1427 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1428 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1429 1430 nd6log((LOG_DEBUG, 1431 "%s: DAD complete for %s - no duplicates found\n", 1432 if_name(ifa->ifa_ifp), 1433 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1434 if (dp->dad_ns_lcount > 0) 1435 log(LOG_ERR, "%s: DAD completed while " 1436 "a looped back NS message is detected " 1437 "during DAD for %s.\n", 1438 if_name(ifa->ifa_ifp), 1439 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1440 } 1441 } 1442 err: 1443 nd6_dad_del(dp); 1444 done: 1445 NET_EPOCH_EXIT(et); 1446 CURVNET_RESTORE(); 1447 } 1448 1449 static void 1450 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1451 { 1452 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1453 struct ifnet *ifp; 1454 char ip6buf[INET6_ADDRSTRLEN]; 1455 1456 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1457 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1458 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1459 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1460 dp->dad_na_icount); 1461 1462 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1463 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1464 1465 ifp = ifa->ifa_ifp; 1466 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1467 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1468 log(LOG_ERR, "%s: manual intervention required\n", 1469 if_name(ifp)); 1470 1471 /* 1472 * If the address is a link-local address formed from an interface 1473 * identifier based on the hardware address which is supposed to be 1474 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1475 * operation on the interface SHOULD be disabled. 1476 * [RFC 4862, Section 5.4.5] 1477 */ 1478 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1479 struct in6_addr in6; 1480 1481 /* 1482 * To avoid over-reaction, we only apply this logic when we are 1483 * very sure that hardware addresses are supposed to be unique. 1484 */ 1485 switch (ifp->if_type) { 1486 case IFT_ETHER: 1487 case IFT_ATM: 1488 case IFT_IEEE1394: 1489 case IFT_INFINIBAND: 1490 in6 = ia->ia_addr.sin6_addr; 1491 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1492 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1493 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1494 log(LOG_ERR, "%s: possible hardware address " 1495 "duplication detected, disable IPv6\n", 1496 if_name(ifp)); 1497 } 1498 break; 1499 } 1500 } 1501 } 1502 1503 static void 1504 nd6_dad_ns_output(struct dadq *dp) 1505 { 1506 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1507 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1508 int i; 1509 1510 dp->dad_ns_tcount++; 1511 if ((ifp->if_flags & IFF_UP) == 0) { 1512 return; 1513 } 1514 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1515 return; 1516 } 1517 1518 dp->dad_ns_ocount++; 1519 if (V_dad_enhanced != 0) { 1520 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1521 dp->dad_nonce[i] = arc4random(); 1522 /* 1523 * XXXHRS: Note that in the case that 1524 * DupAddrDetectTransmits > 1, multiple NS messages with 1525 * different nonces can be looped back in an unexpected 1526 * order. The current implementation recognizes only 1527 * the latest nonce on the sender side. Practically it 1528 * should work well in almost all cases. 1529 */ 1530 } 1531 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1532 (uint8_t *)&dp->dad_nonce[0]); 1533 } 1534 1535 static void 1536 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1537 { 1538 struct dadq *dp; 1539 1540 if (ifa == NULL) 1541 panic("ifa == NULL in nd6_dad_ns_input"); 1542 1543 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1544 if (V_dad_enhanced == 0) 1545 ndopt_nonce = NULL; 1546 dp = nd6_dad_find(ifa, ndopt_nonce); 1547 if (dp == NULL) 1548 return; 1549 1550 dp->dad_ns_icount++; 1551 nd6_dad_rele(dp); 1552 } 1553 1554 static void 1555 nd6_dad_na_input(struct ifaddr *ifa) 1556 { 1557 struct dadq *dp; 1558 1559 if (ifa == NULL) 1560 panic("ifa == NULL in nd6_dad_na_input"); 1561 1562 dp = nd6_dad_find(ifa, NULL); 1563 if (dp != NULL) { 1564 dp->dad_na_icount++; 1565 nd6_dad_rele(dp); 1566 } 1567 }
Cache object: 323fd4b77d407b9abf9d289d805d178f
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