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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 #include "opt_mpath.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.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 #ifdef RADIX_MPATH 66 #include <net/radix_mpath.h> 67 #endif 68 #include <net/vnet.h> 69 70 #include <netinet/in.h> 71 #include <netinet/in_var.h> 72 #include <net/if_llatbl.h> 73 #include <netinet6/in6_var.h> 74 #include <netinet6/in6_ifattach.h> 75 #include <netinet/ip6.h> 76 #include <netinet6/ip6_var.h> 77 #include <netinet6/scope6_var.h> 78 #include <netinet6/nd6.h> 79 #include <netinet/icmp6.h> 80 #include <netinet/ip_carp.h> 81 #include <netinet6/send.h> 82 83 #define SDL(s) ((struct sockaddr_dl *)s) 84 85 struct dadq; 86 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *); 87 static void nd6_dad_add(struct dadq *dp); 88 static void nd6_dad_del(struct dadq *dp); 89 static void nd6_dad_rele(struct dadq *); 90 static void nd6_dad_starttimer(struct dadq *, int, int); 91 static void nd6_dad_stoptimer(struct dadq *); 92 static void nd6_dad_timer(struct dadq *); 93 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *); 94 static void nd6_dad_ns_output(struct dadq *); 95 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *); 96 static void nd6_dad_na_input(struct ifaddr *); 97 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 98 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 99 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *, 100 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int); 101 102 VNET_DEFINE_STATIC(int, dad_enhanced) = 1; 103 #define V_dad_enhanced VNET(dad_enhanced) 104 105 SYSCTL_DECL(_net_inet6_ip6); 106 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW, 107 &VNET_NAME(dad_enhanced), 0, 108 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD."); 109 110 VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to 111 transmit DAD packet */ 112 #define V_dad_maxtry VNET(dad_maxtry) 113 114 /* 115 * Input a Neighbor Solicitation Message. 116 * 117 * Based on RFC 2461 118 * Based on RFC 2462 (duplicate address detection) 119 */ 120 void 121 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 122 { 123 struct ifnet *ifp; 124 struct ip6_hdr *ip6; 125 struct nd_neighbor_solicit *nd_ns; 126 struct in6_addr daddr6, myaddr6, saddr6, taddr6; 127 struct ifaddr *ifa; 128 struct sockaddr_dl proxydl; 129 union nd_opts ndopts; 130 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 131 char *lladdr; 132 int anycast, lladdrlen, proxy, rflag, tentative, tlladdr; 133 134 ifa = NULL; 135 136 /* RFC 6980: Nodes MUST silently ignore fragments */ 137 if(m->m_flags & M_FRAGMENTED) 138 goto freeit; 139 140 ifp = m->m_pkthdr.rcvif; 141 ip6 = mtod(m, struct ip6_hdr *); 142 if (ip6->ip6_hlim != 255) { 143 nd6log((LOG_ERR, 144 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 145 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 146 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 147 goto bads; 148 } 149 150 if (m->m_len < off + icmp6len) { 151 m = m_pullup(m, off + icmp6len); 152 if (m == NULL) { 153 IP6STAT_INC(ip6s_exthdrtoolong); 154 return; 155 } 156 } 157 ip6 = mtod(m, struct ip6_hdr *); 158 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 159 160 saddr6 = ip6->ip6_src; 161 daddr6 = ip6->ip6_dst; 162 taddr6 = nd_ns->nd_ns_target; 163 if (in6_setscope(&taddr6, ifp, NULL) != 0) 164 goto bad; 165 166 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 167 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 168 rflag = 0; 169 170 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 171 /* dst has to be a solicited node multicast address. */ 172 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 173 /* don't check ifindex portion */ 174 daddr6.s6_addr32[1] == 0 && 175 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 176 daddr6.s6_addr8[12] == 0xff) { 177 ; /* good */ 178 } else { 179 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 180 "(wrong ip6 dst)\n")); 181 goto bad; 182 } 183 } else if (!V_nd6_onlink_ns_rfc4861) { 184 struct sockaddr_in6 src_sa6; 185 186 /* 187 * According to recent IETF discussions, it is not a good idea 188 * to accept a NS from an address which would not be deemed 189 * to be a neighbor otherwise. This point is expected to be 190 * clarified in future revisions of the specification. 191 */ 192 bzero(&src_sa6, sizeof(src_sa6)); 193 src_sa6.sin6_family = AF_INET6; 194 src_sa6.sin6_len = sizeof(src_sa6); 195 src_sa6.sin6_addr = saddr6; 196 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 197 nd6log((LOG_INFO, "nd6_ns_input: " 198 "NS packet from non-neighbor\n")); 199 goto bad; 200 } 201 } 202 203 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 204 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 205 goto bad; 206 } 207 208 icmp6len -= sizeof(*nd_ns); 209 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 210 if (nd6_options(&ndopts) < 0) { 211 nd6log((LOG_INFO, 212 "nd6_ns_input: invalid ND option, ignored\n")); 213 /* nd6_options have incremented stats */ 214 goto freeit; 215 } 216 217 lladdr = NULL; 218 lladdrlen = 0; 219 if (ndopts.nd_opts_src_lladdr) { 220 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 221 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 222 } 223 224 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 225 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 226 "(link-layer address option)\n")); 227 goto bad; 228 } 229 230 /* 231 * Attaching target link-layer address to the NA? 232 * (RFC 2461 7.2.4) 233 * 234 * NS IP dst is unicast/anycast MUST NOT add 235 * NS IP dst is solicited-node multicast MUST add 236 * 237 * In implementation, we add target link-layer address by default. 238 * We do not add one in MUST NOT cases. 239 */ 240 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 241 tlladdr = 0; 242 else 243 tlladdr = 1; 244 245 /* 246 * Target address (taddr6) must be either: 247 * (1) Valid unicast/anycast address for my receiving interface, 248 * (2) Unicast address for which I'm offering proxy service, or 249 * (3) "tentative" address on which DAD is being performed. 250 */ 251 /* (1) and (3) check. */ 252 if (ifp->if_carp) 253 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 254 else 255 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 256 257 /* (2) check. */ 258 proxy = 0; 259 if (ifa == NULL) { 260 struct sockaddr_dl rt_gateway; 261 struct rt_addrinfo info; 262 struct sockaddr_in6 dst6; 263 264 bzero(&dst6, sizeof(dst6)); 265 dst6.sin6_len = sizeof(struct sockaddr_in6); 266 dst6.sin6_family = AF_INET6; 267 dst6.sin6_addr = taddr6; 268 269 bzero(&rt_gateway, sizeof(rt_gateway)); 270 rt_gateway.sdl_len = sizeof(rt_gateway); 271 bzero(&info, sizeof(info)); 272 info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway; 273 274 if (rib_lookup_info(ifp->if_fib, (struct sockaddr *)&dst6, 275 0, 0, &info) == 0) { 276 if ((info.rti_flags & RTF_ANNOUNCE) != 0 && 277 rt_gateway.sdl_family == AF_LINK) { 278 279 /* 280 * proxy NDP for single entry 281 */ 282 proxydl = *SDL(&rt_gateway); 283 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal( 284 ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 285 if (ifa) 286 proxy = 1; 287 } 288 } 289 } 290 if (ifa == NULL) { 291 /* 292 * We've got an NS packet, and we don't have that adddress 293 * assigned for us. We MUST silently ignore it. 294 * See RFC2461 7.2.3. 295 */ 296 goto freeit; 297 } 298 myaddr6 = *IFA_IN6(ifa); 299 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 300 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 301 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 302 goto freeit; 303 304 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 305 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 306 "(if %d, NS packet %d)\n", 307 ip6_sprintf(ip6bufs, &taddr6), 308 ifp->if_addrlen, lladdrlen - 2)); 309 goto bad; 310 } 311 312 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 313 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 314 ip6_sprintf(ip6bufs, &saddr6))); 315 goto freeit; 316 } 317 318 /* 319 * We have neighbor solicitation packet, with target address equals to 320 * one of my tentative address. 321 * 322 * src addr how to process? 323 * --- --- 324 * multicast of course, invalid (rejected in ip6_input) 325 * unicast somebody is doing address resolution -> ignore 326 * unspec dup address detection 327 * 328 * The processing is defined in RFC 2462. 329 */ 330 if (tentative) { 331 /* 332 * If source address is unspecified address, it is for 333 * duplicate address detection. 334 * 335 * If not, the packet is for addess resolution; 336 * silently ignore it. 337 */ 338 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 339 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 340 341 goto freeit; 342 } 343 344 /* 345 * If the source address is unspecified address, entries must not 346 * be created or updated. 347 * It looks that sender is performing DAD. Output NA toward 348 * all-node multicast address, to tell the sender that I'm using 349 * the address. 350 * S bit ("solicited") must be zero. 351 */ 352 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 353 struct in6_addr in6_all; 354 355 in6_all = in6addr_linklocal_allnodes; 356 if (in6_setscope(&in6_all, ifp, NULL) != 0) 357 goto bad; 358 nd6_na_output_fib(ifp, &in6_all, &taddr6, 359 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 360 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 361 M_GETFIB(m)); 362 goto freeit; 363 } 364 365 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 366 ND_NEIGHBOR_SOLICIT, 0); 367 368 nd6_na_output_fib(ifp, &saddr6, &taddr6, 369 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 370 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 371 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 372 freeit: 373 if (ifa != NULL) 374 ifa_free(ifa); 375 m_freem(m); 376 return; 377 378 bad: 379 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 380 ip6_sprintf(ip6bufs, &saddr6))); 381 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 382 ip6_sprintf(ip6bufs, &daddr6))); 383 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 384 ip6_sprintf(ip6bufs, &taddr6))); 385 bads: 386 ICMP6STAT_INC(icp6s_badns); 387 if (ifa != NULL) 388 ifa_free(ifa); 389 m_freem(m); 390 } 391 392 /* 393 * Output a Neighbor Solicitation Message. Caller specifies: 394 * - ICMP6 header source IP6 address 395 * - ND6 header target IP6 address 396 * - ND6 header source datalink address 397 * 398 * Based on RFC 2461 399 * Based on RFC 2462 (duplicate address detection) 400 * 401 * ln - for source address determination 402 * nonce - If non-NULL, NS is used for duplicate address detection and 403 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 404 */ 405 static void 406 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 407 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 408 uint8_t *nonce, u_int fibnum) 409 { 410 struct mbuf *m; 411 struct m_tag *mtag; 412 struct ip6_hdr *ip6; 413 struct nd_neighbor_solicit *nd_ns; 414 struct ip6_moptions im6o; 415 int icmp6len; 416 int maxlen; 417 caddr_t mac; 418 419 if (IN6_IS_ADDR_MULTICAST(taddr6)) 420 return; 421 422 /* estimate the size of message */ 423 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 424 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 425 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 426 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 427 __func__, max_linkhdr, maxlen, MCLBYTES)); 428 429 if (max_linkhdr + maxlen > MHLEN) 430 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 431 else 432 m = m_gethdr(M_NOWAIT, MT_DATA); 433 if (m == NULL) 434 return; 435 M_SETFIB(m, fibnum); 436 437 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 438 m->m_flags |= M_MCAST; 439 im6o.im6o_multicast_ifp = ifp; 440 im6o.im6o_multicast_hlim = 255; 441 im6o.im6o_multicast_loop = 0; 442 } 443 444 icmp6len = sizeof(*nd_ns); 445 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 446 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 447 448 /* fill neighbor solicitation packet */ 449 ip6 = mtod(m, struct ip6_hdr *); 450 ip6->ip6_flow = 0; 451 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 452 ip6->ip6_vfc |= IPV6_VERSION; 453 /* ip6->ip6_plen will be set later */ 454 ip6->ip6_nxt = IPPROTO_ICMPV6; 455 ip6->ip6_hlim = 255; 456 if (daddr6) 457 ip6->ip6_dst = *daddr6; 458 else { 459 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 460 ip6->ip6_dst.s6_addr16[1] = 0; 461 ip6->ip6_dst.s6_addr32[1] = 0; 462 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 463 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 464 ip6->ip6_dst.s6_addr8[12] = 0xff; 465 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 466 goto bad; 467 } 468 if (nonce == NULL) { 469 struct ifaddr *ifa = NULL; 470 471 /* 472 * RFC2461 7.2.2: 473 * "If the source address of the packet prompting the 474 * solicitation is the same as one of the addresses assigned 475 * to the outgoing interface, that address SHOULD be placed 476 * in the IP Source Address of the outgoing solicitation. 477 * Otherwise, any one of the addresses assigned to the 478 * interface should be used." 479 * 480 * We use the source address for the prompting packet 481 * (saddr6), if saddr6 belongs to the outgoing interface. 482 * Otherwise, we perform the source address selection as usual. 483 */ 484 485 if (saddr6 != NULL) 486 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 487 if (ifa != NULL) { 488 /* ip6_src set already. */ 489 ip6->ip6_src = *saddr6; 490 ifa_free(ifa); 491 } else { 492 int error; 493 struct in6_addr dst6, src6; 494 uint32_t scopeid; 495 496 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); 497 error = in6_selectsrc_addr(fibnum, &dst6, 498 scopeid, ifp, &src6, NULL); 499 if (error) { 500 char ip6buf[INET6_ADDRSTRLEN]; 501 nd6log((LOG_DEBUG, "%s: source can't be " 502 "determined: dst=%s, error=%d\n", __func__, 503 ip6_sprintf(ip6buf, &dst6), 504 error)); 505 goto bad; 506 } 507 ip6->ip6_src = src6; 508 } 509 } else { 510 /* 511 * Source address for DAD packet must always be IPv6 512 * unspecified address. (0::0) 513 * We actually don't have to 0-clear the address (we did it 514 * above), but we do so here explicitly to make the intention 515 * clearer. 516 */ 517 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 518 } 519 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 520 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 521 nd_ns->nd_ns_code = 0; 522 nd_ns->nd_ns_reserved = 0; 523 nd_ns->nd_ns_target = *taddr6; 524 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 525 526 /* 527 * Add source link-layer address option. 528 * 529 * spec implementation 530 * --- --- 531 * DAD packet MUST NOT do not add the option 532 * there's no link layer address: 533 * impossible do not add the option 534 * there's link layer address: 535 * Multicast NS MUST add one add the option 536 * Unicast NS SHOULD add one add the option 537 */ 538 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 539 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 540 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 541 /* 8 byte alignments... */ 542 optlen = (optlen + 7) & ~7; 543 544 m->m_pkthdr.len += optlen; 545 m->m_len += optlen; 546 icmp6len += optlen; 547 bzero((caddr_t)nd_opt, optlen); 548 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 549 nd_opt->nd_opt_len = optlen >> 3; 550 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 551 } 552 /* 553 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 554 * This behavior is documented as Enhanced Duplicate Address 555 * Detection in RFC 7527. 556 * net.inet6.ip6.dad_enhanced=0 disables this. 557 */ 558 if (V_dad_enhanced != 0 && nonce != NULL) { 559 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 560 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 561 /* 8-byte alignment is required. */ 562 optlen = (optlen + 7) & ~7; 563 564 m->m_pkthdr.len += optlen; 565 m->m_len += optlen; 566 icmp6len += optlen; 567 bzero((caddr_t)nd_opt, optlen); 568 nd_opt->nd_opt_type = ND_OPT_NONCE; 569 nd_opt->nd_opt_len = optlen >> 3; 570 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 571 } 572 ip6->ip6_plen = htons((u_short)icmp6len); 573 nd_ns->nd_ns_cksum = 0; 574 nd_ns->nd_ns_cksum = 575 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 576 577 if (send_sendso_input_hook != NULL) { 578 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 579 sizeof(unsigned short), M_NOWAIT); 580 if (mtag == NULL) 581 goto bad; 582 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 583 m_tag_prepend(m, mtag); 584 } 585 586 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 587 &im6o, NULL, NULL); 588 icmp6_ifstat_inc(ifp, ifs6_out_msg); 589 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 590 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 591 592 return; 593 594 bad: 595 m_freem(m); 596 } 597 598 #ifndef BURN_BRIDGES 599 void 600 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 601 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 602 { 603 604 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 605 } 606 #endif 607 /* 608 * Neighbor advertisement input handling. 609 * 610 * Based on RFC 2461 611 * Based on RFC 2462 (duplicate address detection) 612 * 613 * the following items are not implemented yet: 614 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 615 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 616 */ 617 void 618 nd6_na_input(struct mbuf *m, int off, int icmp6len) 619 { 620 struct ifnet *ifp; 621 struct ip6_hdr *ip6; 622 struct ifaddr *ifa; 623 struct llentry *ln; 624 struct mbuf *chain; 625 struct nd_neighbor_advert *nd_na; 626 struct in6_addr daddr6, taddr6; 627 struct sockaddr_in6 sin6; 628 union nd_opts ndopts; 629 u_char linkhdr[LLE_MAX_LINKHDR]; 630 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 631 char *lladdr; 632 size_t linkhdrsize; 633 int flags, is_override, is_router, is_solicited; 634 int lladdr_off, lladdrlen, checklink; 635 636 chain = NULL; 637 ln = NULL; 638 checklink = 0; 639 640 /* RFC 6980: Nodes MUST silently ignore fragments */ 641 if(m->m_flags & M_FRAGMENTED) 642 goto freeit; 643 644 ifp = m->m_pkthdr.rcvif; 645 ip6 = mtod(m, struct ip6_hdr *); 646 if (ip6->ip6_hlim != 255) { 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 IF_AFDATA_RLOCK(ifp); 750 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 751 IF_AFDATA_RUNLOCK(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 linkhdrsize = sizeof(linkhdr); 775 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 776 linkhdr, &linkhdrsize, &lladdr_off) != 0) 777 return; 778 779 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize, 780 lladdr_off) == 0) { 781 ln = NULL; 782 goto freeit; 783 } 784 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 785 if (is_solicited) 786 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 787 else 788 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 789 if ((ln->ln_router = is_router) != 0) { 790 /* 791 * This means a router's state has changed from 792 * non-reachable to probably reachable, and might 793 * affect the status of associated prefixes.. 794 */ 795 checklink = 1; 796 } 797 } else { 798 int llchange; 799 800 /* 801 * Check if the link-layer address has changed or not. 802 */ 803 if (lladdr == NULL) 804 llchange = 0; 805 else { 806 if (ln->la_flags & LLE_VALID) { 807 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 808 llchange = 1; 809 else 810 llchange = 0; 811 } else 812 llchange = 1; 813 } 814 815 /* 816 * This is VERY complex. Look at it with care. 817 * 818 * override solicit lladdr llchange action 819 * (L: record lladdr) 820 * 821 * 0 0 n -- (2c) 822 * 0 0 y n (2b) L 823 * 0 0 y y (1) REACHABLE->STALE 824 * 0 1 n -- (2c) *->REACHABLE 825 * 0 1 y n (2b) L *->REACHABLE 826 * 0 1 y y (1) REACHABLE->STALE 827 * 1 0 n -- (2a) 828 * 1 0 y n (2a) L 829 * 1 0 y y (2a) L *->STALE 830 * 1 1 n -- (2a) *->REACHABLE 831 * 1 1 y n (2a) L *->REACHABLE 832 * 1 1 y y (2a) L *->REACHABLE 833 */ 834 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 835 /* 836 * If state is REACHABLE, make it STALE. 837 * no other updates should be done. 838 */ 839 if (ln->ln_state == ND6_LLINFO_REACHABLE) 840 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 841 goto freeit; 842 } else if (is_override /* (2a) */ 843 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 844 || lladdr == NULL) { /* (2c) */ 845 /* 846 * Update link-local address, if any. 847 */ 848 if (lladdr != NULL) { 849 linkhdrsize = sizeof(linkhdr); 850 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 851 linkhdr, &linkhdrsize, &lladdr_off) != 0) 852 goto freeit; 853 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 854 linkhdrsize, lladdr_off) == 0) { 855 ln = NULL; 856 goto freeit; 857 } 858 EVENTHANDLER_INVOKE(lle_event, ln, 859 LLENTRY_RESOLVED); 860 } 861 862 /* 863 * If solicited, make the state REACHABLE. 864 * If not solicited and the link-layer address was 865 * changed, make it STALE. 866 */ 867 if (is_solicited) 868 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 869 else { 870 if (lladdr != NULL && llchange) 871 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 872 } 873 } 874 875 if (ln->ln_router && !is_router) { 876 /* 877 * The peer dropped the router flag. 878 * Remove the sender from the Default Router List and 879 * update the Destination Cache entries. 880 */ 881 struct ifnet *nd6_ifp; 882 883 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 884 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 885 (ND_IFINFO(nd6_ifp)->flags & 886 ND6_IFF_ACCEPT_RTADV) != 0) 887 /* 888 * Even if the neighbor is not in the default 889 * router list, the neighbor may be used as a 890 * next hop for some destinations (e.g. redirect 891 * case). So we must call rt6_flush explicitly. 892 */ 893 rt6_flush(&ip6->ip6_src, ifp); 894 } 895 ln->ln_router = is_router; 896 } 897 /* XXX - QL 898 * Does this matter? 899 * rt->rt_flags &= ~RTF_REJECT; 900 */ 901 ln->la_asked = 0; 902 if (ln->la_hold != NULL) { 903 memset(&sin6, 0, sizeof(sin6)); 904 nd6_grab_holdchain(ln, &chain, &sin6); 905 } 906 freeit: 907 if (ln != NULL) 908 LLE_WUNLOCK(ln); 909 910 if (chain != NULL) 911 nd6_flush_holdchain(ifp, chain, &sin6); 912 913 if (checklink) 914 pfxlist_onlink_check(); 915 916 m_freem(m); 917 return; 918 919 bad: 920 if (ln != NULL) 921 LLE_WUNLOCK(ln); 922 923 ICMP6STAT_INC(icp6s_badna); 924 m_freem(m); 925 } 926 927 /* 928 * Neighbor advertisement output handling. 929 * 930 * Based on RFC 2461 931 * 932 * the following items are not implemented yet: 933 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 934 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 935 * 936 * tlladdr - 1 if include target link-layer address 937 * sdl0 - sockaddr_dl (= proxy NA) or NULL 938 */ 939 static void 940 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 941 const struct in6_addr *taddr6, u_long flags, int tlladdr, 942 struct sockaddr *sdl0, u_int fibnum) 943 { 944 struct mbuf *m; 945 struct m_tag *mtag; 946 struct ip6_hdr *ip6; 947 struct nd_neighbor_advert *nd_na; 948 struct ip6_moptions im6o; 949 struct in6_addr daddr6, dst6, src6; 950 uint32_t scopeid; 951 952 int icmp6len, maxlen, error; 953 caddr_t mac = NULL; 954 955 daddr6 = *daddr6_0; /* make a local copy for modification */ 956 957 /* estimate the size of message */ 958 maxlen = sizeof(*ip6) + sizeof(*nd_na); 959 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 960 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 961 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 962 __func__, max_linkhdr, maxlen, MCLBYTES)); 963 964 if (max_linkhdr + maxlen > MHLEN) 965 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 966 else 967 m = m_gethdr(M_NOWAIT, MT_DATA); 968 if (m == NULL) 969 return; 970 M_SETFIB(m, fibnum); 971 972 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 973 m->m_flags |= M_MCAST; 974 im6o.im6o_multicast_ifp = ifp; 975 im6o.im6o_multicast_hlim = 255; 976 im6o.im6o_multicast_loop = 0; 977 } 978 979 icmp6len = sizeof(*nd_na); 980 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 981 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 982 983 /* fill neighbor advertisement packet */ 984 ip6 = mtod(m, struct ip6_hdr *); 985 ip6->ip6_flow = 0; 986 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 987 ip6->ip6_vfc |= IPV6_VERSION; 988 ip6->ip6_nxt = IPPROTO_ICMPV6; 989 ip6->ip6_hlim = 255; 990 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 991 /* reply to DAD */ 992 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 993 daddr6.s6_addr16[1] = 0; 994 daddr6.s6_addr32[1] = 0; 995 daddr6.s6_addr32[2] = 0; 996 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 997 if (in6_setscope(&daddr6, ifp, NULL)) 998 goto bad; 999 1000 flags &= ~ND_NA_FLAG_SOLICITED; 1001 } 1002 ip6->ip6_dst = daddr6; 1003 1004 /* 1005 * Select a source whose scope is the same as that of the dest. 1006 */ 1007 in6_splitscope(&daddr6, &dst6, &scopeid); 1008 error = in6_selectsrc_addr(fibnum, &dst6, 1009 scopeid, ifp, &src6, NULL); 1010 if (error) { 1011 char ip6buf[INET6_ADDRSTRLEN]; 1012 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1013 "determined: dst=%s, error=%d\n", 1014 ip6_sprintf(ip6buf, &daddr6), error)); 1015 goto bad; 1016 } 1017 ip6->ip6_src = src6; 1018 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1019 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1020 nd_na->nd_na_code = 0; 1021 nd_na->nd_na_target = *taddr6; 1022 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1023 1024 /* 1025 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1026 * see nd6_ns_input() for details. 1027 * Basically, if NS packet is sent to unicast/anycast addr, 1028 * target lladdr option SHOULD NOT be included. 1029 */ 1030 if (tlladdr) { 1031 /* 1032 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1033 * lladdr in sdl0. If we are not proxying (sending NA for 1034 * my address) use lladdr configured for the interface. 1035 */ 1036 if (sdl0 == NULL) { 1037 if (ifp->if_carp) 1038 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1039 if (mac == NULL) 1040 mac = nd6_ifptomac(ifp); 1041 } else if (sdl0->sa_family == AF_LINK) { 1042 struct sockaddr_dl *sdl; 1043 sdl = (struct sockaddr_dl *)sdl0; 1044 if (sdl->sdl_alen == ifp->if_addrlen) 1045 mac = LLADDR(sdl); 1046 } 1047 } 1048 if (tlladdr && mac) { 1049 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1050 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1051 1052 /* roundup to 8 bytes alignment! */ 1053 optlen = (optlen + 7) & ~7; 1054 1055 m->m_pkthdr.len += optlen; 1056 m->m_len += optlen; 1057 icmp6len += optlen; 1058 bzero((caddr_t)nd_opt, optlen); 1059 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1060 nd_opt->nd_opt_len = optlen >> 3; 1061 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1062 } else 1063 flags &= ~ND_NA_FLAG_OVERRIDE; 1064 1065 ip6->ip6_plen = htons((u_short)icmp6len); 1066 nd_na->nd_na_flags_reserved = flags; 1067 nd_na->nd_na_cksum = 0; 1068 nd_na->nd_na_cksum = 1069 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1070 1071 if (send_sendso_input_hook != NULL) { 1072 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1073 sizeof(unsigned short), M_NOWAIT); 1074 if (mtag == NULL) 1075 goto bad; 1076 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1077 m_tag_prepend(m, mtag); 1078 } 1079 1080 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1081 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1082 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1083 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1084 1085 return; 1086 1087 bad: 1088 m_freem(m); 1089 } 1090 1091 #ifndef BURN_BRIDGES 1092 void 1093 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1094 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1095 struct sockaddr *sdl0) 1096 { 1097 1098 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1099 RT_DEFAULT_FIB); 1100 } 1101 #endif 1102 1103 caddr_t 1104 nd6_ifptomac(struct ifnet *ifp) 1105 { 1106 switch (ifp->if_type) { 1107 case IFT_ETHER: 1108 case IFT_IEEE1394: 1109 case IFT_L2VLAN: 1110 case IFT_INFINIBAND: 1111 case IFT_BRIDGE: 1112 return IF_LLADDR(ifp); 1113 default: 1114 return NULL; 1115 } 1116 } 1117 1118 struct dadq { 1119 TAILQ_ENTRY(dadq) dad_list; 1120 struct ifaddr *dad_ifa; 1121 int dad_count; /* max NS to send */ 1122 int dad_ns_tcount; /* # of trials to send NS */ 1123 int dad_ns_ocount; /* NS sent so far */ 1124 int dad_ns_icount; 1125 int dad_na_icount; 1126 int dad_ns_lcount; /* looped back NS */ 1127 int dad_loopbackprobe; /* probing state for loopback detection */ 1128 struct callout dad_timer_ch; 1129 struct vnet *dad_vnet; 1130 u_int dad_refcnt; 1131 #define ND_OPT_NONCE_LEN32 \ 1132 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1133 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1134 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */ 1135 }; 1136 1137 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq); 1138 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock); 1139 #define V_dadq VNET(dadq) 1140 #define V_dad_rwlock VNET(dad_rwlock) 1141 1142 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1143 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1144 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1145 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1146 1147 static void 1148 nd6_dad_add(struct dadq *dp) 1149 { 1150 1151 DADQ_WLOCK(); 1152 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1153 dp->dad_ondadq = true; 1154 DADQ_WUNLOCK(); 1155 } 1156 1157 static void 1158 nd6_dad_del(struct dadq *dp) 1159 { 1160 1161 DADQ_WLOCK(); 1162 if (dp->dad_ondadq) { 1163 /* 1164 * Remove dp from the dadq and release the dadq's 1165 * reference. 1166 */ 1167 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1168 dp->dad_ondadq = false; 1169 DADQ_WUNLOCK(); 1170 nd6_dad_rele(dp); 1171 } else 1172 DADQ_WUNLOCK(); 1173 } 1174 1175 static struct dadq * 1176 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1177 { 1178 struct dadq *dp; 1179 1180 DADQ_RLOCK(); 1181 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1182 if (dp->dad_ifa != ifa) 1183 continue; 1184 /* 1185 * Skip if the nonce matches the received one. 1186 * +2 in the length is required because of type and 1187 * length fields are included in a header. 1188 */ 1189 if (n != NULL && 1190 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1191 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1192 ND_OPT_NONCE_LEN) == 0) { 1193 dp->dad_ns_lcount++; 1194 continue; 1195 } 1196 refcount_acquire(&dp->dad_refcnt); 1197 break; 1198 } 1199 DADQ_RUNLOCK(); 1200 1201 return (dp); 1202 } 1203 1204 static void 1205 nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns) 1206 { 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 1249 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0, 1250 ("starting DAD on non-tentative address %p", ifa)); 1251 1252 /* 1253 * If we don't need DAD, don't do it. 1254 * There are several cases: 1255 * - DAD is disabled globally or on the interface 1256 * - the interface address is anycast 1257 */ 1258 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 || 1259 V_ip6_dad_count == 0 || 1260 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) != 0) { 1261 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1262 return; 1263 } 1264 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 || 1265 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || 1266 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) != 0) 1267 return; 1268 1269 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1270 /* 1271 * DAD is already in progress. Let the existing entry 1272 * finish it. 1273 */ 1274 nd6_dad_rele(dp); 1275 return; 1276 } 1277 1278 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1279 if (dp == NULL) { 1280 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1281 "%s(%s)\n", 1282 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1283 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1284 return; 1285 } 1286 callout_init(&dp->dad_timer_ch, 0); 1287 #ifdef VIMAGE 1288 dp->dad_vnet = curvnet; 1289 #endif 1290 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1291 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1292 1293 /* 1294 * Send NS packet for DAD, ip6_dad_count times. 1295 * Note that we must delay the first transmission, if this is the 1296 * first packet to be sent from the interface after interface 1297 * (re)initialization. 1298 */ 1299 dp->dad_ifa = ifa; 1300 ifa_ref(dp->dad_ifa); 1301 dp->dad_count = V_ip6_dad_count; 1302 dp->dad_ns_icount = dp->dad_na_icount = 0; 1303 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1304 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1305 1306 /* Add this to the dadq and add a reference for the dadq. */ 1307 refcount_init(&dp->dad_refcnt, 1); 1308 nd6_dad_add(dp); 1309 nd6_dad_starttimer(dp, delay, 0); 1310 } 1311 1312 /* 1313 * terminate DAD unconditionally. used for address removals. 1314 */ 1315 void 1316 nd6_dad_stop(struct ifaddr *ifa) 1317 { 1318 struct dadq *dp; 1319 1320 dp = nd6_dad_find(ifa, NULL); 1321 if (!dp) { 1322 /* DAD wasn't started yet */ 1323 return; 1324 } 1325 1326 nd6_dad_stoptimer(dp); 1327 nd6_dad_del(dp); 1328 1329 /* Release this function's reference, acquired by nd6_dad_find(). */ 1330 nd6_dad_rele(dp); 1331 } 1332 1333 static void 1334 nd6_dad_timer(struct dadq *dp) 1335 { 1336 CURVNET_SET(dp->dad_vnet); 1337 struct ifaddr *ifa = dp->dad_ifa; 1338 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1339 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1340 char ip6buf[INET6_ADDRSTRLEN]; 1341 1342 KASSERT(ia != NULL, ("DAD entry %p with no address", dp)); 1343 1344 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1345 /* Do not need DAD for ifdisabled interface. */ 1346 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1347 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1348 goto err; 1349 } 1350 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1351 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1352 "%s(%s)\n", 1353 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1354 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1355 goto err; 1356 } 1357 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1358 log(LOG_ERR, "nd6_dad_timer: called with non-tentative 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 1365 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1366 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1367 (((ifp->if_flags & IFF_UP) == 0) || 1368 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1369 nd6log((LOG_INFO, "%s: could not run DAD " 1370 "because the interface was down or not running.\n", 1371 if_name(ifa->ifa_ifp))); 1372 goto err; 1373 } 1374 1375 /* Need more checks? */ 1376 if (dp->dad_ns_ocount < dp->dad_count) { 1377 /* 1378 * We have more NS to go. Send NS packet for DAD. 1379 */ 1380 nd6_dad_starttimer(dp, 1381 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1); 1382 goto done; 1383 } else { 1384 /* 1385 * We have transmitted sufficient number of DAD packets. 1386 * See what we've got. 1387 */ 1388 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1389 /* We've seen NS or NA, means DAD has failed. */ 1390 nd6_dad_duplicated(ifa, dp); 1391 else if (V_dad_enhanced != 0 && 1392 dp->dad_ns_lcount > 0 && 1393 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1394 /* 1395 * Sec. 4.1 in RFC 7527 requires transmission of 1396 * additional probes until the loopback condition 1397 * becomes clear when a looped back probe is detected. 1398 */ 1399 log(LOG_ERR, "%s: a looped back NS message is " 1400 "detected during DAD for %s. " 1401 "Another DAD probes are being sent.\n", 1402 if_name(ifa->ifa_ifp), 1403 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1404 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1405 /* 1406 * Send an NS immediately and increase dad_count by 1407 * V_nd6_mmaxtries - 1. 1408 */ 1409 dp->dad_count = 1410 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1411 nd6_dad_starttimer(dp, 1412 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1413 1); 1414 goto done; 1415 } else { 1416 /* 1417 * We are done with DAD. No NA came, no NS came. 1418 * No duplicate address found. Check IFDISABLED flag 1419 * again in case that it is changed between the 1420 * beginning of this function and here. 1421 */ 1422 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1423 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1424 1425 nd6log((LOG_DEBUG, 1426 "%s: DAD complete for %s - no duplicates found\n", 1427 if_name(ifa->ifa_ifp), 1428 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1429 if (dp->dad_ns_lcount > 0) 1430 log(LOG_ERR, "%s: DAD completed while " 1431 "a looped back NS message is detected " 1432 "during DAD for %s.\n", 1433 if_name(ifa->ifa_ifp), 1434 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1435 } 1436 } 1437 err: 1438 nd6_dad_del(dp); 1439 done: 1440 CURVNET_RESTORE(); 1441 } 1442 1443 static void 1444 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1445 { 1446 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1447 struct ifnet *ifp; 1448 char ip6buf[INET6_ADDRSTRLEN]; 1449 1450 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1451 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1452 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1453 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1454 dp->dad_na_icount); 1455 1456 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1457 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1458 1459 ifp = ifa->ifa_ifp; 1460 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1461 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1462 log(LOG_ERR, "%s: manual intervention required\n", 1463 if_name(ifp)); 1464 1465 /* 1466 * If the address is a link-local address formed from an interface 1467 * identifier based on the hardware address which is supposed to be 1468 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1469 * operation on the interface SHOULD be disabled. 1470 * [RFC 4862, Section 5.4.5] 1471 */ 1472 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1473 struct in6_addr in6; 1474 1475 /* 1476 * To avoid over-reaction, we only apply this logic when we are 1477 * very sure that hardware addresses are supposed to be unique. 1478 */ 1479 switch (ifp->if_type) { 1480 case IFT_ETHER: 1481 case IFT_ATM: 1482 case IFT_IEEE1394: 1483 case IFT_INFINIBAND: 1484 in6 = ia->ia_addr.sin6_addr; 1485 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1486 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1487 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1488 log(LOG_ERR, "%s: possible hardware address " 1489 "duplication detected, disable IPv6\n", 1490 if_name(ifp)); 1491 } 1492 break; 1493 } 1494 } 1495 } 1496 1497 static void 1498 nd6_dad_ns_output(struct dadq *dp) 1499 { 1500 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1501 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1502 int i; 1503 1504 dp->dad_ns_tcount++; 1505 if ((ifp->if_flags & IFF_UP) == 0) { 1506 return; 1507 } 1508 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1509 return; 1510 } 1511 1512 dp->dad_ns_ocount++; 1513 if (V_dad_enhanced != 0) { 1514 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1515 dp->dad_nonce[i] = arc4random(); 1516 /* 1517 * XXXHRS: Note that in the case that 1518 * DupAddrDetectTransmits > 1, multiple NS messages with 1519 * different nonces can be looped back in an unexpected 1520 * order. The current implementation recognizes only 1521 * the latest nonce on the sender side. Practically it 1522 * should work well in almost all cases. 1523 */ 1524 } 1525 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1526 (uint8_t *)&dp->dad_nonce[0]); 1527 } 1528 1529 static void 1530 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1531 { 1532 struct dadq *dp; 1533 1534 if (ifa == NULL) 1535 panic("ifa == NULL in nd6_dad_ns_input"); 1536 1537 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1538 if (V_dad_enhanced == 0) 1539 ndopt_nonce = NULL; 1540 dp = nd6_dad_find(ifa, ndopt_nonce); 1541 if (dp == NULL) 1542 return; 1543 1544 dp->dad_ns_icount++; 1545 nd6_dad_rele(dp); 1546 } 1547 1548 static void 1549 nd6_dad_na_input(struct ifaddr *ifa) 1550 { 1551 struct dadq *dp; 1552 1553 if (ifa == NULL) 1554 panic("ifa == NULL in nd6_dad_na_input"); 1555 1556 dp = nd6_dad_find(ifa, NULL); 1557 if (dp != NULL) { 1558 dp->dad_na_icount++; 1559 nd6_dad_rele(dp); 1560 } 1561 }
Cache object: 7eea84aae5050fdedb8403b35f52430d
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