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sys/netinet6/nd6_nbr.c
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1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $ 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 #include "opt_ipsec.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/eventhandler.h> 44 #include <sys/malloc.h> 45 #include <sys/libkern.h> 46 #include <sys/lock.h> 47 #include <sys/rwlock.h> 48 #include <sys/mbuf.h> 49 #include <sys/socket.h> 50 #include <sys/sockio.h> 51 #include <sys/time.h> 52 #include <sys/kernel.h> 53 #include <sys/errno.h> 54 #include <sys/sysctl.h> 55 #include <sys/syslog.h> 56 #include <sys/queue.h> 57 #include <sys/callout.h> 58 #include <sys/refcount.h> 59 60 #include <net/if.h> 61 #include <net/if_types.h> 62 #include <net/if_dl.h> 63 #include <net/if_var.h> 64 #include <net/route.h> 65 #include <net/vnet.h> 66 67 #include <netinet/in.h> 68 #include <netinet/in_var.h> 69 #include <net/if_llatbl.h> 70 #include <netinet6/in6_var.h> 71 #include <netinet6/in6_ifattach.h> 72 #include <netinet/ip6.h> 73 #include <netinet6/ip6_var.h> 74 #include <netinet6/scope6_var.h> 75 #include <netinet6/nd6.h> 76 #include <netinet/icmp6.h> 77 #include <netinet/ip_carp.h> 78 #include <netinet6/send.h> 79 80 #define SDL(s) ((struct sockaddr_dl *)s) 81 82 struct dadq; 83 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *); 84 static void nd6_dad_add(struct dadq *dp); 85 static void nd6_dad_del(struct dadq *dp); 86 static void nd6_dad_rele(struct dadq *); 87 static void nd6_dad_starttimer(struct dadq *, int); 88 static void nd6_dad_stoptimer(struct dadq *); 89 static void nd6_dad_timer(void *); 90 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *); 91 static void nd6_dad_ns_output(struct dadq *); 92 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *); 93 static void nd6_dad_na_input(struct ifaddr *); 94 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 95 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 96 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *, 97 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int); 98 99 VNET_DEFINE_STATIC(int, dad_enhanced) = 1; 100 #define V_dad_enhanced VNET(dad_enhanced) 101 102 SYSCTL_DECL(_net_inet6_ip6); 103 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW, 104 &VNET_NAME(dad_enhanced), 0, 105 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD."); 106 107 VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to 108 transmit DAD packet */ 109 #define V_dad_maxtry VNET(dad_maxtry) 110 111 /* 112 * Input a Neighbor Solicitation Message. 113 * 114 * Based on RFC 2461 115 * Based on RFC 2462 (duplicate address detection) 116 */ 117 void 118 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 119 { 120 struct ifnet *ifp; 121 struct ip6_hdr *ip6; 122 struct nd_neighbor_solicit *nd_ns; 123 struct in6_addr daddr6, myaddr6, saddr6, taddr6; 124 struct ifaddr *ifa; 125 struct sockaddr_dl proxydl; 126 union nd_opts ndopts; 127 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 128 char *lladdr; 129 int anycast, lladdrlen, proxy, rflag, tentative, tlladdr; 130 131 ifa = NULL; 132 133 /* RFC 6980: Nodes MUST silently ignore fragments */ 134 if(m->m_flags & M_FRAGMENTED) 135 goto freeit; 136 137 ifp = m->m_pkthdr.rcvif; 138 ip6 = mtod(m, struct ip6_hdr *); 139 if (__predict_false(ip6->ip6_hlim != 255)) { 140 ICMP6STAT_INC(icp6s_invlhlim); 141 nd6log((LOG_ERR, 142 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 143 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 144 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 145 goto bads; 146 } 147 148 if (m->m_len < off + icmp6len) { 149 m = m_pullup(m, off + icmp6len); 150 if (m == NULL) { 151 IP6STAT_INC(ip6s_exthdrtoolong); 152 return; 153 } 154 } 155 ip6 = mtod(m, struct ip6_hdr *); 156 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 157 158 saddr6 = ip6->ip6_src; 159 daddr6 = ip6->ip6_dst; 160 taddr6 = nd_ns->nd_ns_target; 161 if (in6_setscope(&taddr6, ifp, NULL) != 0) 162 goto bad; 163 164 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 165 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 166 rflag = 0; 167 168 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 169 /* dst has to be a solicited node multicast address. */ 170 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 171 /* don't check ifindex portion */ 172 daddr6.s6_addr32[1] == 0 && 173 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 174 daddr6.s6_addr8[12] == 0xff) { 175 ; /* good */ 176 } else { 177 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 178 "(wrong ip6 dst)\n")); 179 goto bad; 180 } 181 } else if (!V_nd6_onlink_ns_rfc4861) { 182 struct sockaddr_in6 src_sa6; 183 184 /* 185 * According to recent IETF discussions, it is not a good idea 186 * to accept a NS from an address which would not be deemed 187 * to be a neighbor otherwise. This point is expected to be 188 * clarified in future revisions of the specification. 189 */ 190 bzero(&src_sa6, sizeof(src_sa6)); 191 src_sa6.sin6_family = AF_INET6; 192 src_sa6.sin6_len = sizeof(src_sa6); 193 src_sa6.sin6_addr = saddr6; 194 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 195 nd6log((LOG_INFO, "nd6_ns_input: " 196 "NS packet from non-neighbor\n")); 197 goto bad; 198 } 199 } 200 201 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 202 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 203 goto bad; 204 } 205 206 icmp6len -= sizeof(*nd_ns); 207 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 208 if (nd6_options(&ndopts) < 0) { 209 nd6log((LOG_INFO, 210 "nd6_ns_input: invalid ND option, ignored\n")); 211 /* nd6_options have incremented stats */ 212 goto freeit; 213 } 214 215 lladdr = NULL; 216 lladdrlen = 0; 217 if (ndopts.nd_opts_src_lladdr) { 218 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 219 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 220 } 221 222 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 223 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 224 "(link-layer address option)\n")); 225 goto bad; 226 } 227 228 /* 229 * Attaching target link-layer address to the NA? 230 * (RFC 2461 7.2.4) 231 * 232 * NS IP dst is unicast/anycast MUST NOT add 233 * NS IP dst is solicited-node multicast MUST add 234 * 235 * In implementation, we add target link-layer address by default. 236 * We do not add one in MUST NOT cases. 237 */ 238 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 239 tlladdr = 0; 240 else 241 tlladdr = 1; 242 243 /* 244 * Target address (taddr6) must be either: 245 * (1) Valid unicast/anycast address for my receiving interface, 246 * (2) Unicast address for which I'm offering proxy service, or 247 * (3) "tentative" address on which DAD is being performed. 248 */ 249 /* (1) and (3) check. */ 250 if (ifp->if_carp) 251 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 252 else 253 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 254 255 /* (2) check. */ 256 proxy = 0; 257 if (ifa == NULL) { 258 struct sockaddr_dl rt_gateway; 259 struct rt_addrinfo info; 260 struct sockaddr_in6 dst6; 261 262 bzero(&dst6, sizeof(dst6)); 263 dst6.sin6_len = sizeof(struct sockaddr_in6); 264 dst6.sin6_family = AF_INET6; 265 dst6.sin6_addr = taddr6; 266 267 bzero(&rt_gateway, sizeof(rt_gateway)); 268 rt_gateway.sdl_len = sizeof(rt_gateway); 269 bzero(&info, sizeof(info)); 270 info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway; 271 272 if (rib_lookup_info(ifp->if_fib, (struct sockaddr *)&dst6, 273 0, 0, &info) == 0) { 274 if ((info.rti_flags & RTF_ANNOUNCE) != 0 && 275 rt_gateway.sdl_family == AF_LINK) { 276 /* 277 * proxy NDP for single entry 278 */ 279 proxydl = *SDL(&rt_gateway); 280 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal( 281 ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 282 if (ifa) 283 proxy = 1; 284 } 285 } 286 } 287 if (ifa == NULL) { 288 /* 289 * We've got an NS packet, and we don't have that adddress 290 * assigned for us. We MUST silently ignore it. 291 * See RFC2461 7.2.3. 292 */ 293 goto freeit; 294 } 295 myaddr6 = *IFA_IN6(ifa); 296 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 297 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 298 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 299 goto freeit; 300 301 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 302 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 303 "(if %d, NS packet %d)\n", 304 ip6_sprintf(ip6bufs, &taddr6), 305 ifp->if_addrlen, lladdrlen - 2)); 306 goto bad; 307 } 308 309 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 310 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 311 ip6_sprintf(ip6bufs, &saddr6))); 312 goto freeit; 313 } 314 315 /* 316 * We have neighbor solicitation packet, with target address equals to 317 * one of my tentative address. 318 * 319 * src addr how to process? 320 * --- --- 321 * multicast of course, invalid (rejected in ip6_input) 322 * unicast somebody is doing address resolution -> ignore 323 * unspec dup address detection 324 * 325 * The processing is defined in RFC 2462. 326 */ 327 if (tentative) { 328 /* 329 * If source address is unspecified address, it is for 330 * duplicate address detection. 331 * 332 * If not, the packet is for addess resolution; 333 * silently ignore it. 334 */ 335 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 336 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 337 338 goto freeit; 339 } 340 341 /* 342 * If the source address is unspecified address, entries must not 343 * be created or updated. 344 * It looks that sender is performing DAD. Output NA toward 345 * all-node multicast address, to tell the sender that I'm using 346 * the address. 347 * S bit ("solicited") must be zero. 348 */ 349 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 350 struct in6_addr in6_all; 351 352 in6_all = in6addr_linklocal_allnodes; 353 if (in6_setscope(&in6_all, ifp, NULL) != 0) 354 goto bad; 355 nd6_na_output_fib(ifp, &in6_all, &taddr6, 356 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 357 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 358 M_GETFIB(m)); 359 goto freeit; 360 } 361 362 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 363 ND_NEIGHBOR_SOLICIT, 0); 364 365 nd6_na_output_fib(ifp, &saddr6, &taddr6, 366 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 367 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 368 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 369 freeit: 370 if (ifa != NULL) 371 ifa_free(ifa); 372 m_freem(m); 373 return; 374 375 bad: 376 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 377 ip6_sprintf(ip6bufs, &saddr6))); 378 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 379 ip6_sprintf(ip6bufs, &daddr6))); 380 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 381 ip6_sprintf(ip6bufs, &taddr6))); 382 bads: 383 ICMP6STAT_INC(icp6s_badns); 384 if (ifa != NULL) 385 ifa_free(ifa); 386 m_freem(m); 387 } 388 389 /* 390 * Output a Neighbor Solicitation Message. Caller specifies: 391 * - ICMP6 header source IP6 address 392 * - ND6 header target IP6 address 393 * - ND6 header source datalink address 394 * 395 * Based on RFC 2461 396 * Based on RFC 2462 (duplicate address detection) 397 * 398 * ln - for source address determination 399 * nonce - If non-NULL, NS is used for duplicate address detection and 400 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 401 */ 402 static void 403 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 404 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 405 uint8_t *nonce, u_int fibnum) 406 { 407 struct mbuf *m; 408 struct m_tag *mtag; 409 struct ip6_hdr *ip6; 410 struct nd_neighbor_solicit *nd_ns; 411 struct ip6_moptions im6o; 412 int icmp6len; 413 int maxlen; 414 415 NET_EPOCH_ASSERT(); 416 417 if (IN6_IS_ADDR_MULTICAST(taddr6)) 418 return; 419 420 /* estimate the size of message */ 421 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 422 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 423 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 424 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 425 __func__, max_linkhdr, maxlen, MCLBYTES)); 426 427 if (max_linkhdr + maxlen > MHLEN) 428 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 429 else 430 m = m_gethdr(M_NOWAIT, MT_DATA); 431 if (m == NULL) 432 return; 433 M_SETFIB(m, fibnum); 434 435 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 436 m->m_flags |= M_MCAST; 437 im6o.im6o_multicast_ifp = ifp; 438 im6o.im6o_multicast_hlim = 255; 439 im6o.im6o_multicast_loop = 0; 440 } 441 442 icmp6len = sizeof(*nd_ns); 443 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 444 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 445 446 /* fill neighbor solicitation packet */ 447 ip6 = mtod(m, struct ip6_hdr *); 448 ip6->ip6_flow = 0; 449 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 450 ip6->ip6_vfc |= IPV6_VERSION; 451 /* ip6->ip6_plen will be set later */ 452 ip6->ip6_nxt = IPPROTO_ICMPV6; 453 ip6->ip6_hlim = 255; 454 if (daddr6) 455 ip6->ip6_dst = *daddr6; 456 else { 457 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 458 ip6->ip6_dst.s6_addr16[1] = 0; 459 ip6->ip6_dst.s6_addr32[1] = 0; 460 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 461 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 462 ip6->ip6_dst.s6_addr8[12] = 0xff; 463 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 464 goto bad; 465 } 466 if (nonce == NULL) { 467 struct ifaddr *ifa = NULL; 468 469 /* 470 * RFC2461 7.2.2: 471 * "If the source address of the packet prompting the 472 * solicitation is the same as one of the addresses assigned 473 * to the outgoing interface, that address SHOULD be placed 474 * in the IP Source Address of the outgoing solicitation. 475 * Otherwise, any one of the addresses assigned to the 476 * interface should be used." 477 * 478 * We use the source address for the prompting packet 479 * (saddr6), if saddr6 belongs to the outgoing interface. 480 * Otherwise, we perform the source address selection as usual. 481 */ 482 483 if (saddr6 != NULL) 484 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 485 if (ifa != NULL) { 486 /* ip6_src set already. */ 487 ip6->ip6_src = *saddr6; 488 ifa_free(ifa); 489 } else { 490 int error; 491 struct in6_addr dst6, src6; 492 uint32_t scopeid; 493 494 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); 495 error = in6_selectsrc_addr(fibnum, &dst6, 496 scopeid, ifp, &src6, NULL); 497 if (error) { 498 char ip6buf[INET6_ADDRSTRLEN]; 499 nd6log((LOG_DEBUG, "%s: source can't be " 500 "determined: dst=%s, error=%d\n", __func__, 501 ip6_sprintf(ip6buf, &dst6), 502 error)); 503 goto bad; 504 } 505 ip6->ip6_src = src6; 506 } 507 } else { 508 /* 509 * Source address for DAD packet must always be IPv6 510 * unspecified address. (0::0) 511 * We actually don't have to 0-clear the address (we did it 512 * above), but we do so here explicitly to make the intention 513 * clearer. 514 */ 515 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 516 } 517 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 518 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 519 nd_ns->nd_ns_code = 0; 520 nd_ns->nd_ns_reserved = 0; 521 nd_ns->nd_ns_target = *taddr6; 522 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 523 524 /* 525 * Add source link-layer address option. 526 * 527 * spec implementation 528 * --- --- 529 * DAD packet MUST NOT do not add the option 530 * there's no link layer address: 531 * impossible do not add the option 532 * there's link layer address: 533 * Multicast NS MUST add one add the option 534 * Unicast NS SHOULD add one add the option 535 */ 536 if (nonce == NULL) { 537 struct nd_opt_hdr *nd_opt; 538 char *mac; 539 int optlen; 540 541 mac = NULL; 542 if (ifp->if_carp) 543 mac = (*carp_macmatch6_p)(ifp, m, &ip6->ip6_src); 544 if (mac == NULL) 545 mac = nd6_ifptomac(ifp); 546 547 if (mac != NULL) { 548 nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 549 optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 550 /* 8 byte alignments... */ 551 optlen = (optlen + 7) & ~7; 552 m->m_pkthdr.len += optlen; 553 m->m_len += optlen; 554 icmp6len += optlen; 555 bzero(nd_opt, optlen); 556 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 557 nd_opt->nd_opt_len = optlen >> 3; 558 bcopy(mac, nd_opt + 1, ifp->if_addrlen); 559 } 560 } 561 /* 562 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 563 * This behavior is documented as Enhanced Duplicate Address 564 * Detection in RFC 7527. 565 * net.inet6.ip6.dad_enhanced=0 disables this. 566 */ 567 if (V_dad_enhanced != 0 && nonce != NULL) { 568 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 569 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 570 /* 8-byte alignment is required. */ 571 optlen = (optlen + 7) & ~7; 572 573 m->m_pkthdr.len += optlen; 574 m->m_len += optlen; 575 icmp6len += optlen; 576 bzero((caddr_t)nd_opt, optlen); 577 nd_opt->nd_opt_type = ND_OPT_NONCE; 578 nd_opt->nd_opt_len = optlen >> 3; 579 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 580 } 581 ip6->ip6_plen = htons((u_short)icmp6len); 582 nd_ns->nd_ns_cksum = 0; 583 nd_ns->nd_ns_cksum = 584 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 585 586 if (send_sendso_input_hook != NULL) { 587 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 588 sizeof(unsigned short), M_NOWAIT); 589 if (mtag == NULL) 590 goto bad; 591 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 592 m_tag_prepend(m, mtag); 593 } 594 595 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 596 &im6o, NULL, NULL); 597 icmp6_ifstat_inc(ifp, ifs6_out_msg); 598 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 599 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 600 601 return; 602 603 bad: 604 m_freem(m); 605 } 606 607 #ifndef BURN_BRIDGES 608 void 609 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 610 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 611 { 612 613 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 614 } 615 #endif 616 /* 617 * Neighbor advertisement input handling. 618 * 619 * Based on RFC 2461 620 * Based on RFC 2462 (duplicate address detection) 621 * 622 * the following items are not implemented yet: 623 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 624 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 625 */ 626 void 627 nd6_na_input(struct mbuf *m, int off, int icmp6len) 628 { 629 struct ifnet *ifp; 630 struct ip6_hdr *ip6; 631 struct ifaddr *ifa; 632 struct llentry *ln; 633 struct mbuf *chain; 634 struct nd_neighbor_advert *nd_na; 635 struct in6_addr daddr6, taddr6; 636 union nd_opts ndopts; 637 u_char linkhdr[LLE_MAX_LINKHDR]; 638 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 639 char *lladdr; 640 size_t linkhdrsize; 641 int flags, is_override, is_router, is_solicited; 642 int lladdr_off, lladdrlen, checklink; 643 bool flush_holdchain = false; 644 645 NET_EPOCH_ASSERT(); 646 647 chain = NULL; 648 ln = NULL; 649 checklink = 0; 650 651 /* RFC 6980: Nodes MUST silently ignore fragments */ 652 if(m->m_flags & M_FRAGMENTED) 653 goto freeit; 654 655 ifp = m->m_pkthdr.rcvif; 656 ip6 = mtod(m, struct ip6_hdr *); 657 if (__predict_false(ip6->ip6_hlim != 255)) { 658 ICMP6STAT_INC(icp6s_invlhlim); 659 nd6log((LOG_ERR, 660 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 661 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 662 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 663 goto bad; 664 } 665 666 if (m->m_len < off + icmp6len) { 667 m = m_pullup(m, off + icmp6len); 668 if (m == NULL) { 669 IP6STAT_INC(ip6s_exthdrtoolong); 670 return; 671 } 672 } 673 ip6 = mtod(m, struct ip6_hdr *); 674 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 675 676 flags = nd_na->nd_na_flags_reserved; 677 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 678 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 679 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 680 681 taddr6 = nd_na->nd_na_target; 682 if (in6_setscope(&taddr6, ifp, NULL)) 683 goto bad; /* XXX: impossible */ 684 685 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 686 nd6log((LOG_ERR, 687 "nd6_na_input: invalid target address %s\n", 688 ip6_sprintf(ip6bufs, &taddr6))); 689 goto bad; 690 } 691 692 daddr6 = ip6->ip6_dst; 693 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 694 if (is_solicited) { 695 nd6log((LOG_ERR, 696 "nd6_na_input: a solicited adv is multicasted\n")); 697 goto bad; 698 } 699 700 icmp6len -= sizeof(*nd_na); 701 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 702 if (nd6_options(&ndopts) < 0) { 703 nd6log((LOG_INFO, 704 "nd6_na_input: invalid ND option, ignored\n")); 705 /* nd6_options have incremented stats */ 706 goto freeit; 707 } 708 709 lladdr = NULL; 710 lladdrlen = 0; 711 if (ndopts.nd_opts_tgt_lladdr) { 712 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 713 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 714 } 715 716 /* 717 * This effectively disables the DAD check on a non-master CARP 718 * address. 719 */ 720 if (ifp->if_carp) 721 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 722 else 723 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 724 725 /* 726 * Target address matches one of my interface address. 727 * 728 * If my address is tentative, this means that there's somebody 729 * already using the same address as mine. This indicates DAD failure. 730 * This is defined in RFC 2462. 731 * 732 * Otherwise, process as defined in RFC 2461. 733 */ 734 if (ifa 735 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 736 nd6_dad_na_input(ifa); 737 ifa_free(ifa); 738 goto freeit; 739 } 740 741 /* Just for safety, maybe unnecessary. */ 742 if (ifa) { 743 ifa_free(ifa); 744 log(LOG_ERR, 745 "nd6_na_input: duplicate IP6 address %s\n", 746 ip6_sprintf(ip6bufs, &taddr6)); 747 goto freeit; 748 } 749 750 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 751 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 752 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 753 ifp->if_addrlen, lladdrlen - 2)); 754 goto bad; 755 } 756 757 /* 758 * If no neighbor cache entry is found, NA SHOULD silently be 759 * discarded. 760 */ 761 ln = nd6_lookup(&taddr6, LLE_SF(AF_INET6, LLE_EXCLUSIVE), ifp); 762 if (ln == NULL) { 763 goto freeit; 764 } 765 766 /* 767 * Do not try to override static entry. 768 */ 769 if (ln->la_flags & LLE_STATIC) 770 goto freeit; 771 772 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 773 /* 774 * If the link-layer has address, and no lladdr option came, 775 * discard the packet. 776 */ 777 if (ifp->if_addrlen && lladdr == NULL) { 778 goto freeit; 779 } 780 781 /* 782 * Record link-layer address, and update the state. 783 */ 784 if (!nd6_try_set_entry_addr(ifp, ln, lladdr)) 785 goto freeit; 786 787 flush_holdchain = true; 788 if (is_solicited) 789 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 790 else 791 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 792 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 793 if ((ln->ln_router = is_router) != 0) { 794 /* 795 * This means a router's state has changed from 796 * non-reachable to probably reachable, and might 797 * affect the status of associated prefixes.. 798 */ 799 checklink = 1; 800 } 801 } else { 802 int llchange; 803 804 /* 805 * Check if the link-layer address has changed or not. 806 */ 807 if (lladdr == NULL) 808 llchange = 0; 809 else { 810 if (ln->la_flags & LLE_VALID) { 811 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 812 llchange = 1; 813 else 814 llchange = 0; 815 } else 816 llchange = 1; 817 } 818 819 /* 820 * This is VERY complex. Look at it with care. 821 * 822 * override solicit lladdr llchange action 823 * (L: record lladdr) 824 * 825 * 0 0 n -- (2c) 826 * 0 0 y n (2b) L 827 * 0 0 y y (1) REACHABLE->STALE 828 * 0 1 n -- (2c) *->REACHABLE 829 * 0 1 y n (2b) L *->REACHABLE 830 * 0 1 y y (1) REACHABLE->STALE 831 * 1 0 n -- (2a) 832 * 1 0 y n (2a) L 833 * 1 0 y y (2a) L *->STALE 834 * 1 1 n -- (2a) *->REACHABLE 835 * 1 1 y n (2a) L *->REACHABLE 836 * 1 1 y y (2a) L *->REACHABLE 837 */ 838 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 839 /* 840 * If state is REACHABLE, make it STALE. 841 * no other updates should be done. 842 */ 843 if (ln->ln_state == ND6_LLINFO_REACHABLE) 844 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 845 goto freeit; 846 } else if (is_override /* (2a) */ 847 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 848 || lladdr == NULL) { /* (2c) */ 849 /* 850 * Update link-local address, if any. 851 */ 852 if (lladdr != NULL) { 853 linkhdrsize = sizeof(linkhdr); 854 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 855 linkhdr, &linkhdrsize, &lladdr_off) != 0) 856 goto freeit; 857 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 858 linkhdrsize, lladdr_off) == 0) 859 goto freeit; 860 EVENTHANDLER_INVOKE(lle_event, ln, 861 LLENTRY_RESOLVED); 862 } 863 864 /* 865 * If solicited, make the state REACHABLE. 866 * If not solicited and the link-layer address was 867 * changed, make it STALE. 868 */ 869 if (is_solicited) 870 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 871 else { 872 if (lladdr != NULL && llchange) 873 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 874 } 875 } 876 877 if (ln->ln_router && !is_router) { 878 /* 879 * The peer dropped the router flag. 880 * Remove the sender from the Default Router List and 881 * update the Destination Cache entries. 882 */ 883 struct ifnet *nd6_ifp; 884 885 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 886 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 887 (ND_IFINFO(nd6_ifp)->flags & 888 ND6_IFF_ACCEPT_RTADV) != 0) 889 /* 890 * Even if the neighbor is not in the default 891 * router list, the neighbor may be used as a 892 * next hop for some destinations (e.g. redirect 893 * case). So we must call rt6_flush explicitly. 894 */ 895 rt6_flush(&ip6->ip6_src, ifp); 896 } 897 ln->ln_router = is_router; 898 } 899 /* XXX - QL 900 * Does this matter? 901 * rt->rt_flags &= ~RTF_REJECT; 902 */ 903 ln->la_asked = 0; 904 if (ln->la_hold != NULL) 905 chain = nd6_grab_holdchain(ln); 906 freeit: 907 if (ln != NULL) 908 LLE_WUNLOCK(ln); 909 910 if (chain != NULL) 911 nd6_flush_holdchain(ifp, ln, chain); 912 if (flush_holdchain) 913 nd6_flush_children_holdchain(ifp, ln); 914 915 if (checklink) 916 pfxlist_onlink_check(); 917 918 m_freem(m); 919 return; 920 921 bad: 922 if (ln != NULL) 923 LLE_WUNLOCK(ln); 924 925 ICMP6STAT_INC(icp6s_badna); 926 m_freem(m); 927 } 928 929 /* 930 * Neighbor advertisement output handling. 931 * 932 * Based on RFC 2461 933 * 934 * the following items are not implemented yet: 935 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 936 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 937 * 938 * tlladdr - 1 if include target link-layer address 939 * sdl0 - sockaddr_dl (= proxy NA) or NULL 940 */ 941 static void 942 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 943 const struct in6_addr *taddr6, u_long flags, int tlladdr, 944 struct sockaddr *sdl0, u_int fibnum) 945 { 946 struct mbuf *m; 947 struct m_tag *mtag; 948 struct ip6_hdr *ip6; 949 struct nd_neighbor_advert *nd_na; 950 struct ip6_moptions im6o; 951 struct in6_addr daddr6, dst6, src6; 952 uint32_t scopeid; 953 954 NET_EPOCH_ASSERT(); 955 956 int icmp6len, maxlen, error; 957 caddr_t mac = NULL; 958 959 daddr6 = *daddr6_0; /* make a local copy for modification */ 960 961 /* estimate the size of message */ 962 maxlen = sizeof(*ip6) + sizeof(*nd_na); 963 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 964 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 965 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 966 __func__, max_linkhdr, maxlen, MCLBYTES)); 967 968 if (max_linkhdr + maxlen > MHLEN) 969 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 970 else 971 m = m_gethdr(M_NOWAIT, MT_DATA); 972 if (m == NULL) 973 return; 974 M_SETFIB(m, fibnum); 975 976 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 977 m->m_flags |= M_MCAST; 978 im6o.im6o_multicast_ifp = ifp; 979 im6o.im6o_multicast_hlim = 255; 980 im6o.im6o_multicast_loop = 0; 981 } 982 983 icmp6len = sizeof(*nd_na); 984 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 985 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 986 987 /* fill neighbor advertisement packet */ 988 ip6 = mtod(m, struct ip6_hdr *); 989 ip6->ip6_flow = 0; 990 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 991 ip6->ip6_vfc |= IPV6_VERSION; 992 ip6->ip6_nxt = IPPROTO_ICMPV6; 993 ip6->ip6_hlim = 255; 994 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 995 /* reply to DAD */ 996 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 997 daddr6.s6_addr16[1] = 0; 998 daddr6.s6_addr32[1] = 0; 999 daddr6.s6_addr32[2] = 0; 1000 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 1001 if (in6_setscope(&daddr6, ifp, NULL)) 1002 goto bad; 1003 1004 flags &= ~ND_NA_FLAG_SOLICITED; 1005 } 1006 ip6->ip6_dst = daddr6; 1007 1008 /* 1009 * Select a source whose scope is the same as that of the dest. 1010 */ 1011 in6_splitscope(&daddr6, &dst6, &scopeid); 1012 error = in6_selectsrc_addr(fibnum, &dst6, 1013 scopeid, ifp, &src6, NULL); 1014 if (error) { 1015 char ip6buf[INET6_ADDRSTRLEN]; 1016 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1017 "determined: dst=%s, error=%d\n", 1018 ip6_sprintf(ip6buf, &daddr6), error)); 1019 goto bad; 1020 } 1021 ip6->ip6_src = src6; 1022 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1023 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1024 nd_na->nd_na_code = 0; 1025 nd_na->nd_na_target = *taddr6; 1026 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1027 1028 /* 1029 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1030 * see nd6_ns_input() for details. 1031 * Basically, if NS packet is sent to unicast/anycast addr, 1032 * target lladdr option SHOULD NOT be included. 1033 */ 1034 if (tlladdr) { 1035 /* 1036 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1037 * lladdr in sdl0. If we are not proxying (sending NA for 1038 * my address) use lladdr configured for the interface. 1039 */ 1040 if (sdl0 == NULL) { 1041 if (ifp->if_carp) 1042 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1043 if (mac == NULL) 1044 mac = nd6_ifptomac(ifp); 1045 } else if (sdl0->sa_family == AF_LINK) { 1046 struct sockaddr_dl *sdl; 1047 sdl = (struct sockaddr_dl *)sdl0; 1048 if (sdl->sdl_alen == ifp->if_addrlen) 1049 mac = LLADDR(sdl); 1050 } 1051 } 1052 if (tlladdr && mac) { 1053 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1054 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1055 1056 /* roundup to 8 bytes alignment! */ 1057 optlen = (optlen + 7) & ~7; 1058 1059 m->m_pkthdr.len += optlen; 1060 m->m_len += optlen; 1061 icmp6len += optlen; 1062 bzero((caddr_t)nd_opt, optlen); 1063 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1064 nd_opt->nd_opt_len = optlen >> 3; 1065 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1066 } else 1067 flags &= ~ND_NA_FLAG_OVERRIDE; 1068 1069 ip6->ip6_plen = htons((u_short)icmp6len); 1070 nd_na->nd_na_flags_reserved = flags; 1071 nd_na->nd_na_cksum = 0; 1072 nd_na->nd_na_cksum = 1073 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1074 1075 if (send_sendso_input_hook != NULL) { 1076 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1077 sizeof(unsigned short), M_NOWAIT); 1078 if (mtag == NULL) 1079 goto bad; 1080 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1081 m_tag_prepend(m, mtag); 1082 } 1083 1084 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1085 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1086 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1087 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1088 1089 return; 1090 1091 bad: 1092 m_freem(m); 1093 } 1094 1095 #ifndef BURN_BRIDGES 1096 void 1097 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1098 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1099 struct sockaddr *sdl0) 1100 { 1101 1102 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1103 RT_DEFAULT_FIB); 1104 } 1105 #endif 1106 1107 caddr_t 1108 nd6_ifptomac(struct ifnet *ifp) 1109 { 1110 switch (ifp->if_type) { 1111 case IFT_ETHER: 1112 case IFT_IEEE1394: 1113 case IFT_L2VLAN: 1114 case IFT_INFINIBAND: 1115 case IFT_BRIDGE: 1116 return IF_LLADDR(ifp); 1117 default: 1118 return NULL; 1119 } 1120 } 1121 1122 struct dadq { 1123 TAILQ_ENTRY(dadq) dad_list; 1124 struct ifaddr *dad_ifa; 1125 int dad_count; /* max NS to send */ 1126 int dad_ns_tcount; /* # of trials to send NS */ 1127 int dad_ns_ocount; /* NS sent so far */ 1128 int dad_ns_icount; 1129 int dad_na_icount; 1130 int dad_ns_lcount; /* looped back NS */ 1131 int dad_loopbackprobe; /* probing state for loopback detection */ 1132 struct callout dad_timer_ch; 1133 struct vnet *dad_vnet; 1134 u_int dad_refcnt; 1135 #define ND_OPT_NONCE_LEN32 \ 1136 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1137 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1138 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */ 1139 }; 1140 1141 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq); 1142 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock); 1143 #define V_dadq VNET(dadq) 1144 #define V_dad_rwlock VNET(dad_rwlock) 1145 1146 #define DADQ_LOCKPTR() (&V_dad_rwlock) 1147 #define DADQ_LOCK_INIT() rw_init(DADQ_LOCKPTR(), "nd6 DAD queue") 1148 #define DADQ_RLOCK() rw_rlock(DADQ_LOCKPTR()) 1149 #define DADQ_RUNLOCK() rw_runlock(DADQ_LOCKPTR()) 1150 #define DADQ_WLOCK() rw_wlock(DADQ_LOCKPTR()) 1151 #define DADQ_WUNLOCK() rw_wunlock(DADQ_LOCKPTR()) 1152 1153 #define DADQ_LOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_LOCKED); 1154 #define DADQ_RLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_RLOCKED); 1155 #define DADQ_WLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_WLOCKED); 1156 1157 static void 1158 nd6_dad_add(struct dadq *dp) 1159 { 1160 DADQ_WLOCK_ASSERT(); 1161 1162 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1163 dp->dad_ondadq = true; 1164 } 1165 1166 static void 1167 nd6_dad_del(struct dadq *dp) 1168 { 1169 DADQ_WLOCK_ASSERT(); 1170 1171 if (dp->dad_ondadq) { 1172 /* 1173 * Remove dp from the dadq and release the dadq's 1174 * reference. 1175 */ 1176 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1177 dp->dad_ondadq = false; 1178 nd6_dad_rele(dp); 1179 } 1180 } 1181 1182 static struct dadq * 1183 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1184 { 1185 struct dadq *dp; 1186 1187 DADQ_LOCK_ASSERT(); 1188 1189 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1190 if (dp->dad_ifa != ifa) 1191 continue; 1192 1193 /* 1194 * Skip if the nonce matches the received one. 1195 * +2 in the length is required because of type and 1196 * length fields are included in a header. 1197 */ 1198 if (n != NULL && 1199 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1200 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1201 ND_OPT_NONCE_LEN) == 0) { 1202 dp->dad_ns_lcount++; 1203 continue; 1204 } 1205 break; 1206 } 1207 1208 return (dp); 1209 } 1210 1211 static void 1212 nd6_dad_starttimer(struct dadq *dp, int ticks) 1213 { 1214 DADQ_WLOCK_ASSERT(); 1215 1216 callout_reset(&dp->dad_timer_ch, ticks, nd6_dad_timer, dp); 1217 } 1218 1219 static void 1220 nd6_dad_stoptimer(struct dadq *dp) 1221 { 1222 callout_drain(&dp->dad_timer_ch); 1223 } 1224 1225 static void 1226 nd6_dad_rele(struct dadq *dp) 1227 { 1228 if (refcount_release(&dp->dad_refcnt)) { 1229 KASSERT(!dp->dad_ondadq, ("dp %p still on DAD queue", dp)); 1230 ifa_free(dp->dad_ifa); 1231 free(dp, M_IP6NDP); 1232 } 1233 } 1234 1235 void 1236 nd6_dad_init(void) 1237 { 1238 DADQ_LOCK_INIT(); 1239 TAILQ_INIT(&V_dadq); 1240 } 1241 1242 /* 1243 * Start Duplicate Address Detection (DAD) for specified interface address. 1244 */ 1245 void 1246 nd6_dad_start(struct ifaddr *ifa, int delay) 1247 { 1248 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1249 struct dadq *dp; 1250 char ip6buf[INET6_ADDRSTRLEN]; 1251 1252 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0, 1253 ("starting DAD on non-tentative address %p", ifa)); 1254 1255 /* 1256 * If we don't need DAD, don't do it. 1257 * There are several cases: 1258 * - DAD is disabled globally or on the interface 1259 * - the interface address is anycast 1260 */ 1261 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 || 1262 V_ip6_dad_count == 0 || 1263 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) != 0) { 1264 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1265 return; 1266 } 1267 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 || 1268 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || 1269 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) != 0) 1270 return; 1271 1272 DADQ_WLOCK(); 1273 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1274 /* 1275 * DAD is already in progress. Let the existing entry 1276 * finish it. 1277 */ 1278 DADQ_WUNLOCK(); 1279 return; 1280 } 1281 1282 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1283 if (dp == NULL) { 1284 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1285 "%s(%s)\n", 1286 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1287 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1288 return; 1289 } 1290 callout_init_rw(&dp->dad_timer_ch, DADQ_LOCKPTR(), 1291 CALLOUT_RETURNUNLOCKED); 1292 #ifdef VIMAGE 1293 dp->dad_vnet = curvnet; 1294 #endif 1295 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1296 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1297 1298 /* 1299 * Send NS packet for DAD, ip6_dad_count times. 1300 * Note that we must delay the first transmission, if this is the 1301 * first packet to be sent from the interface after interface 1302 * (re)initialization. 1303 */ 1304 dp->dad_ifa = ifa; 1305 ifa_ref(dp->dad_ifa); 1306 dp->dad_count = V_ip6_dad_count; 1307 dp->dad_ns_icount = dp->dad_na_icount = 0; 1308 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1309 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1310 1311 /* Add this to the dadq and add a reference for the dadq. */ 1312 refcount_init(&dp->dad_refcnt, 1); 1313 nd6_dad_add(dp); 1314 nd6_dad_starttimer(dp, delay); 1315 DADQ_WUNLOCK(); 1316 } 1317 1318 /* 1319 * terminate DAD unconditionally. used for address removals. 1320 */ 1321 void 1322 nd6_dad_stop(struct ifaddr *ifa) 1323 { 1324 struct dadq *dp; 1325 1326 DADQ_WLOCK(); 1327 dp = nd6_dad_find(ifa, NULL); 1328 if (dp == NULL) { 1329 DADQ_WUNLOCK(); 1330 /* DAD wasn't started yet */ 1331 return; 1332 } 1333 1334 /* 1335 * Acquire a temporary reference so that we can safely stop the callout. 1336 */ 1337 (void)refcount_acquire(&dp->dad_refcnt); 1338 nd6_dad_del(dp); 1339 DADQ_WUNLOCK(); 1340 1341 nd6_dad_stoptimer(dp); 1342 nd6_dad_rele(dp); 1343 } 1344 1345 static void 1346 nd6_dad_timer(void *arg) 1347 { 1348 struct dadq *dp = arg; 1349 struct ifaddr *ifa = dp->dad_ifa; 1350 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1351 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1352 char ip6buf[INET6_ADDRSTRLEN]; 1353 struct epoch_tracker et; 1354 1355 CURVNET_SET(dp->dad_vnet); 1356 KASSERT(ia != NULL, ("DAD entry %p with no address", dp)); 1357 1358 NET_EPOCH_ENTER(et); 1359 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1360 /* Do not need DAD for ifdisabled interface. */ 1361 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1362 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1363 goto err; 1364 } 1365 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1366 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1367 "%s(%s)\n", 1368 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1369 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1370 goto err; 1371 } 1372 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1373 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1374 "%s(%s)\n", 1375 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1376 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1377 goto err; 1378 } 1379 1380 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1381 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1382 (((ifp->if_flags & IFF_UP) == 0) || 1383 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1384 nd6log((LOG_INFO, "%s: could not run DAD " 1385 "because the interface was down or not running.\n", 1386 if_name(ifa->ifa_ifp))); 1387 goto err; 1388 } 1389 1390 /* Need more checks? */ 1391 if (dp->dad_ns_ocount < dp->dad_count) { 1392 /* 1393 * We have more NS to go. Send NS packet for DAD. 1394 */ 1395 nd6_dad_starttimer(dp, 1396 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1397 nd6_dad_ns_output(dp); 1398 goto done; 1399 } else { 1400 /* 1401 * We have transmitted sufficient number of DAD packets. 1402 * See what we've got. 1403 */ 1404 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) { 1405 /* We've seen NS or NA, means DAD has failed. */ 1406 nd6_dad_duplicated(ifa, dp); 1407 } else if (V_dad_enhanced != 0 && 1408 dp->dad_ns_lcount > 0 && 1409 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1410 /* 1411 * Sec. 4.1 in RFC 7527 requires transmission of 1412 * additional probes until the loopback condition 1413 * becomes clear when a looped back probe is detected. 1414 */ 1415 log(LOG_ERR, "%s: a looped back NS message is " 1416 "detected during DAD for %s. " 1417 "Another DAD probes are being sent.\n", 1418 if_name(ifa->ifa_ifp), 1419 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1420 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1421 /* 1422 * Send an NS immediately and increase dad_count by 1423 * V_nd6_mmaxtries - 1. 1424 */ 1425 dp->dad_count = 1426 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1427 nd6_dad_starttimer(dp, 1428 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1429 nd6_dad_ns_output(dp); 1430 goto done; 1431 } else { 1432 /* 1433 * We are done with DAD. No NA came, no NS came. 1434 * No duplicate address found. Check IFDISABLED flag 1435 * again in case that it is changed between the 1436 * beginning of this function and here. 1437 */ 1438 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1439 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1440 1441 nd6log((LOG_DEBUG, 1442 "%s: DAD complete for %s - no duplicates found\n", 1443 if_name(ifa->ifa_ifp), 1444 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1445 if (dp->dad_ns_lcount > 0) 1446 log(LOG_ERR, "%s: DAD completed while " 1447 "a looped back NS message is detected " 1448 "during DAD for %s.\n", 1449 if_name(ifa->ifa_ifp), 1450 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1451 } 1452 } 1453 err: 1454 nd6_dad_del(dp); 1455 DADQ_WUNLOCK(); 1456 done: 1457 NET_EPOCH_EXIT(et); 1458 CURVNET_RESTORE(); 1459 } 1460 1461 static void 1462 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1463 { 1464 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1465 struct ifnet *ifp; 1466 char ip6buf[INET6_ADDRSTRLEN]; 1467 1468 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1469 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1470 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1471 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1472 dp->dad_na_icount); 1473 1474 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1475 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1476 1477 ifp = ifa->ifa_ifp; 1478 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1479 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1480 log(LOG_ERR, "%s: manual intervention required\n", 1481 if_name(ifp)); 1482 1483 /* 1484 * If the address is a link-local address formed from an interface 1485 * identifier based on the hardware address which is supposed to be 1486 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1487 * operation on the interface SHOULD be disabled. 1488 * [RFC 4862, Section 5.4.5] 1489 */ 1490 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1491 struct in6_addr in6; 1492 1493 /* 1494 * To avoid over-reaction, we only apply this logic when we are 1495 * very sure that hardware addresses are supposed to be unique. 1496 */ 1497 switch (ifp->if_type) { 1498 case IFT_ETHER: 1499 case IFT_ATM: 1500 case IFT_IEEE1394: 1501 case IFT_INFINIBAND: 1502 in6 = ia->ia_addr.sin6_addr; 1503 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1504 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1505 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1506 log(LOG_ERR, "%s: possible hardware address " 1507 "duplication detected, disable IPv6\n", 1508 if_name(ifp)); 1509 } 1510 break; 1511 } 1512 } 1513 } 1514 1515 /* 1516 * Transmit a neighbour solicitation for the purpose of DAD. Returns with the 1517 * DAD queue unlocked. 1518 */ 1519 static void 1520 nd6_dad_ns_output(struct dadq *dp) 1521 { 1522 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1523 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1524 int i; 1525 1526 DADQ_WLOCK_ASSERT(); 1527 1528 dp->dad_ns_tcount++; 1529 if ((ifp->if_flags & IFF_UP) == 0) { 1530 DADQ_WUNLOCK(); 1531 return; 1532 } 1533 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1534 DADQ_WUNLOCK(); 1535 return; 1536 } 1537 1538 dp->dad_ns_ocount++; 1539 if (V_dad_enhanced != 0) { 1540 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1541 dp->dad_nonce[i] = arc4random(); 1542 /* 1543 * XXXHRS: Note that in the case that 1544 * DupAddrDetectTransmits > 1, multiple NS messages with 1545 * different nonces can be looped back in an unexpected 1546 * order. The current implementation recognizes only 1547 * the latest nonce on the sender side. Practically it 1548 * should work well in almost all cases. 1549 */ 1550 } 1551 DADQ_WUNLOCK(); 1552 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1553 (uint8_t *)&dp->dad_nonce[0]); 1554 } 1555 1556 static void 1557 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1558 { 1559 struct dadq *dp; 1560 1561 if (ifa == NULL) 1562 panic("ifa == NULL in nd6_dad_ns_input"); 1563 1564 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1565 if (V_dad_enhanced == 0) 1566 ndopt_nonce = NULL; 1567 DADQ_RLOCK(); 1568 dp = nd6_dad_find(ifa, ndopt_nonce); 1569 if (dp != NULL) 1570 dp->dad_ns_icount++; 1571 DADQ_RUNLOCK(); 1572 } 1573 1574 static void 1575 nd6_dad_na_input(struct ifaddr *ifa) 1576 { 1577 struct dadq *dp; 1578 1579 if (ifa == NULL) 1580 panic("ifa == NULL in nd6_dad_na_input"); 1581 1582 DADQ_RLOCK(); 1583 dp = nd6_dad_find(ifa, NULL); 1584 if (dp != NULL) 1585 dp->dad_na_icount++; 1586 DADQ_RUNLOCK(); 1587 }
Cache object: 27448a96858edfa1991954ea176d9732
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