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 #include "opt_inet.h" 36 #include "opt_inet6.h" 37 #include "opt_ipsec.h" 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/counter.h> 42 #include <sys/eventhandler.h> 43 #include <sys/malloc.h> 44 #include <sys/libkern.h> 45 #include <sys/lock.h> 46 #include <sys/rwlock.h> 47 #include <sys/mbuf.h> 48 #include <sys/socket.h> 49 #include <sys/sockio.h> 50 #include <sys/time.h> 51 #include <sys/kernel.h> 52 #include <sys/errno.h> 53 #include <sys/sysctl.h> 54 #include <sys/syslog.h> 55 #include <sys/queue.h> 56 #include <sys/callout.h> 57 #include <sys/refcount.h> 58 59 #include <net/if.h> 60 #include <net/if_types.h> 61 #include <net/if_dl.h> 62 #include <net/if_var.h> 63 #include <net/if_private.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 #include <machine/atomic.h> 81 82 #define SDL(s) ((struct sockaddr_dl *)s) 83 84 struct dadq; 85 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *); 86 static void nd6_dad_add(struct dadq *dp); 87 static void nd6_dad_del(struct dadq *dp); 88 static void nd6_dad_rele(struct dadq *); 89 static void nd6_dad_starttimer(struct dadq *, int); 90 static void nd6_dad_stoptimer(struct dadq *); 91 static void nd6_dad_timer(void *); 92 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *); 93 static void nd6_dad_ns_output(struct dadq *); 94 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *); 95 static void nd6_dad_na_input(struct ifaddr *); 96 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 97 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 98 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *, 99 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int); 100 101 static struct ifaddr *nd6_proxy_fill_sdl(struct ifnet *, 102 const struct in6_addr *, struct sockaddr_dl *); 103 104 VNET_DEFINE_STATIC(int, dad_enhanced) = 1; 105 #define V_dad_enhanced VNET(dad_enhanced) 106 107 SYSCTL_DECL(_net_inet6_ip6); 108 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW, 109 &VNET_NAME(dad_enhanced), 0, 110 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD."); 111 112 VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to 113 transmit DAD packet */ 114 #define V_dad_maxtry VNET(dad_maxtry) 115 116 VNET_DEFINE_STATIC(int, nd6_onlink_ns_rfc4861) = 0; 117 #define V_nd6_onlink_ns_rfc4861 VNET(nd6_onlink_ns_rfc4861) 118 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_ONLINKNSRFC4861, 119 nd6_onlink_ns_rfc4861, CTLFLAG_VNET | CTLFLAG_RW, 120 &VNET_NAME(nd6_onlink_ns_rfc4861), 0, 121 "Accept 'on-link' ICMPv6 NS messages in compliance with RFC 4861"); 122 123 /* 124 * Input a Neighbor Solicitation Message. 125 * 126 * Based on RFC 2461 127 * Based on RFC 2462 (duplicate address detection) 128 */ 129 void 130 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 131 { 132 struct ifnet *ifp; 133 struct ip6_hdr *ip6; 134 struct nd_neighbor_solicit *nd_ns; 135 struct in6_addr daddr6, myaddr6, saddr6, taddr6; 136 struct ifaddr *ifa; 137 struct sockaddr_dl proxydl; 138 union nd_opts ndopts; 139 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 140 char *lladdr; 141 int anycast, lladdrlen, proxy, rflag, tentative, tlladdr; 142 143 ifa = NULL; 144 145 /* RFC 6980: Nodes MUST silently ignore fragments */ 146 if(m->m_flags & M_FRAGMENTED) 147 goto freeit; 148 149 ifp = m->m_pkthdr.rcvif; 150 ip6 = mtod(m, struct ip6_hdr *); 151 if (__predict_false(ip6->ip6_hlim != 255)) { 152 ICMP6STAT_INC(icp6s_invlhlim); 153 nd6log((LOG_ERR, 154 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 155 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 156 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 157 goto bads; 158 } 159 160 if (m->m_len < off + icmp6len) { 161 m = m_pullup(m, off + icmp6len); 162 if (m == NULL) { 163 IP6STAT_INC(ip6s_exthdrtoolong); 164 return; 165 } 166 } 167 ip6 = mtod(m, struct ip6_hdr *); 168 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 169 170 saddr6 = ip6->ip6_src; 171 daddr6 = ip6->ip6_dst; 172 taddr6 = nd_ns->nd_ns_target; 173 if (in6_setscope(&taddr6, ifp, NULL) != 0) 174 goto bad; 175 176 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 177 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 178 rflag = 0; 179 180 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 181 /* dst has to be a solicited node multicast address. */ 182 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 183 /* don't check ifindex portion */ 184 daddr6.s6_addr32[1] == 0 && 185 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 186 daddr6.s6_addr8[12] == 0xff) { 187 ; /* good */ 188 } else { 189 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 190 "(wrong ip6 dst)\n")); 191 goto bad; 192 } 193 } else if (!V_nd6_onlink_ns_rfc4861) { 194 struct sockaddr_in6 src_sa6; 195 196 /* 197 * According to recent IETF discussions, it is not a good idea 198 * to accept a NS from an address which would not be deemed 199 * to be a neighbor otherwise. This point is expected to be 200 * clarified in future revisions of the specification. 201 */ 202 bzero(&src_sa6, sizeof(src_sa6)); 203 src_sa6.sin6_family = AF_INET6; 204 src_sa6.sin6_len = sizeof(src_sa6); 205 src_sa6.sin6_addr = saddr6; 206 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 207 nd6log((LOG_INFO, "nd6_ns_input: " 208 "NS packet from non-neighbor\n")); 209 goto bad; 210 } 211 } 212 213 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 214 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 215 goto bad; 216 } 217 218 icmp6len -= sizeof(*nd_ns); 219 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 220 if (nd6_options(&ndopts) < 0) { 221 nd6log((LOG_INFO, 222 "nd6_ns_input: invalid ND option, ignored\n")); 223 /* nd6_options have incremented stats */ 224 goto freeit; 225 } 226 227 lladdr = NULL; 228 lladdrlen = 0; 229 if (ndopts.nd_opts_src_lladdr) { 230 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 231 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 232 } 233 234 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 235 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 236 "(link-layer address option)\n")); 237 goto bad; 238 } 239 240 /* 241 * Attaching target link-layer address to the NA? 242 * (RFC 2461 7.2.4) 243 * 244 * NS IP dst is unicast/anycast MUST NOT add 245 * NS IP dst is solicited-node multicast MUST add 246 * 247 * In implementation, we add target link-layer address by default. 248 * We do not add one in MUST NOT cases. 249 */ 250 tlladdr = 0; 251 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 252 tlladdr |= ND6_NA_OPT_LLA; 253 254 /* 255 * Target address (taddr6) must be either: 256 * (1) Valid unicast/anycast address for my receiving interface, 257 * (2) Unicast address for which I'm offering proxy service, or 258 * (3) "tentative" address on which DAD is being performed. 259 */ 260 /* (1) and (3) check. */ 261 if (ifp->if_carp) { 262 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 263 if (ifa != NULL) 264 tlladdr |= ND6_NA_CARP_MASTER; 265 } else 266 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 267 268 /* (2) check. */ 269 proxy = 0; 270 if (ifa == NULL) { 271 if ((ifa = nd6_proxy_fill_sdl(ifp, &taddr6, &proxydl)) != NULL) 272 proxy = 1; 273 } 274 if (ifa == NULL) { 275 /* 276 * We've got an NS packet, and we don't have that address 277 * assigned for us. We MUST silently ignore it. 278 * See RFC2461 7.2.3. 279 */ 280 goto freeit; 281 } 282 myaddr6 = *IFA_IN6(ifa); 283 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 284 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 285 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 286 goto freeit; 287 288 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 289 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 290 "(if %d, NS packet %d)\n", 291 ip6_sprintf(ip6bufs, &taddr6), 292 ifp->if_addrlen, lladdrlen - 2)); 293 goto bad; 294 } 295 296 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 297 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 298 ip6_sprintf(ip6bufs, &saddr6))); 299 goto freeit; 300 } 301 302 /* 303 * We have neighbor solicitation packet, with target address equals to 304 * one of my tentative address. 305 * 306 * src addr how to process? 307 * --- --- 308 * multicast of course, invalid (rejected in ip6_input) 309 * unicast somebody is doing address resolution -> ignore 310 * unspec dup address detection 311 * 312 * The processing is defined in RFC 2462. 313 */ 314 if (tentative) { 315 /* 316 * If source address is unspecified address, it is for 317 * duplicate address detection. 318 * 319 * If not, the packet is for addess resolution; 320 * silently ignore it. 321 */ 322 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 323 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 324 325 goto freeit; 326 } 327 328 /* 329 * If the Target Address is either an anycast address or a unicast 330 * address for which the node is providing proxy service, or the Target 331 * Link-Layer Address option is not included, the Override flag SHOULD 332 * be set to zero. Otherwise, the Override flag SHOULD be set to one. 333 */ 334 if (anycast == 0 && proxy == 0 && (tlladdr & ND6_NA_OPT_LLA) != 0) 335 rflag |= ND_NA_FLAG_OVERRIDE; 336 /* 337 * If the source address is unspecified address, entries must not 338 * be created or updated. 339 * It looks that sender is performing DAD. nd6_na_output() will 340 * send NA toward all-node multicast address, to tell the sender 341 * that I'm using the address. 342 * S bit ("solicited") must be zero. 343 */ 344 if (!IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 345 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 346 ND_NEIGHBOR_SOLICIT, 0); 347 rflag |= ND_NA_FLAG_SOLICITED; 348 } 349 350 nd6_na_output_fib(ifp, &saddr6, &taddr6, rflag, tlladdr, 351 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 352 freeit: 353 if (ifa != NULL) 354 ifa_free(ifa); 355 m_freem(m); 356 return; 357 358 bad: 359 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 360 ip6_sprintf(ip6bufs, &saddr6))); 361 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 362 ip6_sprintf(ip6bufs, &daddr6))); 363 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 364 ip6_sprintf(ip6bufs, &taddr6))); 365 bads: 366 ICMP6STAT_INC(icp6s_badns); 367 if (ifa != NULL) 368 ifa_free(ifa); 369 m_freem(m); 370 } 371 372 static struct ifaddr * 373 nd6_proxy_fill_sdl(struct ifnet *ifp, const struct in6_addr *taddr6, 374 struct sockaddr_dl *sdl) 375 { 376 struct ifaddr *ifa; 377 struct llentry *ln; 378 379 ifa = NULL; 380 ln = nd6_lookup(taddr6, LLE_SF(AF_INET6, 0), ifp); 381 if (ln == NULL) 382 return (ifa); 383 if ((ln->la_flags & (LLE_PUB | LLE_VALID)) == (LLE_PUB | LLE_VALID)) { 384 link_init_sdl(ifp, (struct sockaddr *)sdl, ifp->if_type); 385 sdl->sdl_alen = ifp->if_addrlen; 386 bcopy(ln->ll_addr, &sdl->sdl_data, ifp->if_addrlen); 387 LLE_RUNLOCK(ln); 388 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 389 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 390 } else 391 LLE_RUNLOCK(ln); 392 393 return (ifa); 394 } 395 396 /* 397 * Output a Neighbor Solicitation Message. Caller specifies: 398 * - ICMP6 header source IP6 address 399 * - ND6 header target IP6 address 400 * - ND6 header source datalink address 401 * 402 * Based on RFC 2461 403 * Based on RFC 2462 (duplicate address detection) 404 * 405 * ln - for source address determination 406 * nonce - If non-NULL, NS is used for duplicate address detection and 407 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 408 */ 409 static void 410 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 411 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 412 uint8_t *nonce, u_int fibnum) 413 { 414 struct mbuf *m; 415 struct m_tag *mtag; 416 struct ip6_hdr *ip6; 417 struct nd_neighbor_solicit *nd_ns; 418 struct ip6_moptions im6o; 419 int icmp6len; 420 int maxlen; 421 422 NET_EPOCH_ASSERT(); 423 424 if (IN6_IS_ADDR_MULTICAST(taddr6)) 425 return; 426 427 /* estimate the size of message */ 428 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 429 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 430 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 431 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 432 __func__, max_linkhdr, maxlen, MCLBYTES)); 433 434 if (max_linkhdr + maxlen > MHLEN) 435 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 436 else 437 m = m_gethdr(M_NOWAIT, MT_DATA); 438 if (m == NULL) 439 return; 440 M_SETFIB(m, fibnum); 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 (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { 467 m->m_flags |= M_MCAST; 468 im6o.im6o_multicast_ifp = ifp; 469 im6o.im6o_multicast_hlim = 255; 470 im6o.im6o_multicast_loop = 0; 471 } 472 if (nonce == NULL) { 473 char ip6buf[INET6_ADDRSTRLEN]; 474 struct ifaddr *ifa = NULL; 475 476 /* 477 * RFC2461 7.2.2: 478 * "If the source address of the packet prompting the 479 * solicitation is the same as one of the addresses assigned 480 * to the outgoing interface, that address SHOULD be placed 481 * in the IP Source Address of the outgoing solicitation. 482 * Otherwise, any one of the addresses assigned to the 483 * interface should be used." 484 * 485 * We use the source address for the prompting packet 486 * (saddr6), if saddr6 belongs to the outgoing interface. 487 * Otherwise, we perform the source address selection as usual. 488 */ 489 if (saddr6 != NULL) 490 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 491 if (ifa == NULL) { 492 int error; 493 494 error = in6_selectsrc_nbr(fibnum, &ip6->ip6_dst, &im6o, 495 ifp, &ip6->ip6_src); 496 if (error) { 497 nd6log((LOG_DEBUG, "%s: source can't be " 498 "determined: dst=%s, error=%d\n", __func__, 499 ip6_sprintf(ip6buf, &ip6->ip6_dst), 500 error)); 501 goto bad; 502 } 503 } else 504 ip6->ip6_src = *saddr6; 505 506 if (ifp->if_carp != NULL) { 507 /* 508 * Check that selected source address belongs to 509 * CARP addresses. 510 */ 511 if (ifa == NULL) 512 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, 513 &ip6->ip6_src); 514 /* 515 * Do not send NS for CARP address if we are not 516 * the CARP master. 517 */ 518 if (ifa != NULL && ifa->ifa_carp != NULL && 519 !(*carp_master_p)(ifa)) { 520 nd6log((LOG_DEBUG, 521 "nd6_ns_output: NS from BACKUP CARP address %s\n", 522 ip6_sprintf(ip6buf, &ip6->ip6_src))); 523 ifa_free(ifa); 524 goto bad; 525 } 526 } 527 if (ifa != NULL) 528 ifa_free(ifa); 529 } else { 530 /* 531 * Source address for DAD packet must always be IPv6 532 * unspecified address. (0::0) 533 * We actually don't have to 0-clear the address (we did it 534 * above), but we do so here explicitly to make the intention 535 * clearer. 536 */ 537 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 538 } 539 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 540 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 541 nd_ns->nd_ns_code = 0; 542 nd_ns->nd_ns_reserved = 0; 543 nd_ns->nd_ns_target = *taddr6; 544 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 545 546 /* 547 * Add source link-layer address option. 548 * 549 * spec implementation 550 * --- --- 551 * DAD packet MUST NOT do not add the option 552 * there's no link layer address: 553 * impossible do not add the option 554 * there's link layer address: 555 * Multicast NS MUST add one add the option 556 * Unicast NS SHOULD add one add the option 557 */ 558 if (nonce == NULL) { 559 struct nd_opt_hdr *nd_opt; 560 char *mac; 561 int optlen; 562 563 mac = NULL; 564 if (ifp->if_carp) 565 mac = (*carp_macmatch6_p)(ifp, m, &ip6->ip6_src); 566 if (mac == NULL) 567 mac = nd6_ifptomac(ifp); 568 569 if (mac != NULL) { 570 nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 571 optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 572 /* 8 byte alignments... */ 573 optlen = (optlen + 7) & ~7; 574 m->m_pkthdr.len += optlen; 575 m->m_len += optlen; 576 icmp6len += optlen; 577 bzero(nd_opt, optlen); 578 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 579 nd_opt->nd_opt_len = optlen >> 3; 580 bcopy(mac, nd_opt + 1, ifp->if_addrlen); 581 } 582 } 583 /* 584 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 585 * This behavior is documented as Enhanced Duplicate Address 586 * Detection in RFC 7527. 587 * net.inet6.ip6.dad_enhanced=0 disables this. 588 */ 589 if (V_dad_enhanced != 0 && nonce != NULL) { 590 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 591 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 592 /* 8-byte alignment is required. */ 593 optlen = (optlen + 7) & ~7; 594 595 m->m_pkthdr.len += optlen; 596 m->m_len += optlen; 597 icmp6len += optlen; 598 bzero((caddr_t)nd_opt, optlen); 599 nd_opt->nd_opt_type = ND_OPT_NONCE; 600 nd_opt->nd_opt_len = optlen >> 3; 601 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 602 } 603 ip6->ip6_plen = htons((u_short)icmp6len); 604 nd_ns->nd_ns_cksum = 0; 605 nd_ns->nd_ns_cksum = 606 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 607 608 if (send_sendso_input_hook != NULL) { 609 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 610 sizeof(unsigned short), M_NOWAIT); 611 if (mtag == NULL) 612 goto bad; 613 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 614 m_tag_prepend(m, mtag); 615 } 616 617 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 618 &im6o, NULL, NULL); 619 icmp6_ifstat_inc(ifp, ifs6_out_msg); 620 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 621 ICMP6STAT_INC2(icp6s_outhist, ND_NEIGHBOR_SOLICIT); 622 623 return; 624 625 bad: 626 m_freem(m); 627 } 628 629 #ifndef BURN_BRIDGES 630 void 631 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 632 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 633 { 634 635 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 636 } 637 #endif 638 /* 639 * Neighbor advertisement input handling. 640 * 641 * Based on RFC 2461 642 * Based on RFC 2462 (duplicate address detection) 643 * 644 * the following items are not implemented yet: 645 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 646 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 647 */ 648 void 649 nd6_na_input(struct mbuf *m, int off, int icmp6len) 650 { 651 struct ifnet *ifp; 652 struct ip6_hdr *ip6; 653 struct ifaddr *ifa; 654 struct llentry *ln; 655 struct mbuf *chain; 656 struct nd_neighbor_advert *nd_na; 657 struct in6_addr daddr6, taddr6; 658 union nd_opts ndopts; 659 u_char linkhdr[LLE_MAX_LINKHDR]; 660 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 661 char *lladdr; 662 size_t linkhdrsize; 663 int flags, is_override, is_router, is_solicited; 664 int lladdr_off, lladdrlen, checklink; 665 bool flush_holdchain = false; 666 667 NET_EPOCH_ASSERT(); 668 669 chain = NULL; 670 ln = NULL; 671 checklink = 0; 672 673 /* RFC 6980: Nodes MUST silently ignore fragments */ 674 if(m->m_flags & M_FRAGMENTED) 675 goto freeit; 676 677 ifp = m->m_pkthdr.rcvif; 678 ip6 = mtod(m, struct ip6_hdr *); 679 if (__predict_false(ip6->ip6_hlim != 255)) { 680 ICMP6STAT_INC(icp6s_invlhlim); 681 nd6log((LOG_ERR, 682 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 683 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 684 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 685 goto bad; 686 } 687 688 if (m->m_len < off + icmp6len) { 689 m = m_pullup(m, off + icmp6len); 690 if (m == NULL) { 691 IP6STAT_INC(ip6s_exthdrtoolong); 692 return; 693 } 694 } 695 ip6 = mtod(m, struct ip6_hdr *); 696 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 697 698 flags = nd_na->nd_na_flags_reserved; 699 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 700 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 701 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 702 703 taddr6 = nd_na->nd_na_target; 704 if (in6_setscope(&taddr6, ifp, NULL)) 705 goto bad; /* XXX: impossible */ 706 707 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 708 nd6log((LOG_ERR, 709 "nd6_na_input: invalid target address %s\n", 710 ip6_sprintf(ip6bufs, &taddr6))); 711 goto bad; 712 } 713 714 daddr6 = ip6->ip6_dst; 715 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 716 if (is_solicited) { 717 nd6log((LOG_ERR, 718 "nd6_na_input: a solicited adv is multicasted\n")); 719 goto bad; 720 } 721 722 icmp6len -= sizeof(*nd_na); 723 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 724 if (nd6_options(&ndopts) < 0) { 725 nd6log((LOG_INFO, 726 "nd6_na_input: invalid ND option, ignored\n")); 727 /* nd6_options have incremented stats */ 728 goto freeit; 729 } 730 731 lladdr = NULL; 732 lladdrlen = 0; 733 if (ndopts.nd_opts_tgt_lladdr) { 734 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 735 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 736 } 737 738 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 739 if (ifa != NULL && ifa->ifa_carp != NULL) { 740 /* 741 * Silently ignore NAs for CARP addresses if we are not 742 * the CARP master. 743 */ 744 if (!(*carp_master_p)(ifa)) { 745 nd6log((LOG_DEBUG, 746 "nd6_na_input: NA for BACKUP CARP address %s\n", 747 ip6_sprintf(ip6bufs, &taddr6))); 748 ifa_free(ifa); 749 goto freeit; 750 } 751 } 752 /* 753 * Target address matches one of my interface address. 754 * 755 * If my address is tentative, this means that there's somebody 756 * already using the same address as mine. This indicates DAD failure. 757 * This is defined in RFC 2462. 758 * 759 * Otherwise, process as defined in RFC 2461. 760 */ 761 if (ifa 762 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 763 nd6_dad_na_input(ifa); 764 ifa_free(ifa); 765 goto freeit; 766 } 767 768 /* Just for safety, maybe unnecessary. */ 769 if (ifa) { 770 ifa_free(ifa); 771 log(LOG_ERR, 772 "nd6_na_input: duplicate IP6 address %s\n", 773 ip6_sprintf(ip6bufs, &taddr6)); 774 goto freeit; 775 } 776 777 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 778 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 779 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 780 ifp->if_addrlen, lladdrlen - 2)); 781 goto bad; 782 } 783 784 /* 785 * If no neighbor cache entry is found, NA SHOULD silently be 786 * discarded. 787 */ 788 ln = nd6_lookup(&taddr6, LLE_SF(AF_INET6, LLE_EXCLUSIVE), ifp); 789 if (ln == NULL) { 790 goto freeit; 791 } 792 793 /* 794 * Do not try to override static entry. 795 */ 796 if (ln->la_flags & LLE_STATIC) 797 goto freeit; 798 799 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 800 /* 801 * If the link-layer has address, and no lladdr option came, 802 * discard the packet. 803 */ 804 if (ifp->if_addrlen && lladdr == NULL) { 805 goto freeit; 806 } 807 808 /* 809 * Record link-layer address, and update the state. 810 */ 811 if (!nd6_try_set_entry_addr(ifp, ln, lladdr)) 812 goto freeit; 813 814 flush_holdchain = true; 815 if (is_solicited) 816 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 817 else 818 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 819 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 820 if ((ln->ln_router = is_router) != 0) { 821 /* 822 * This means a router's state has changed from 823 * non-reachable to probably reachable, and might 824 * affect the status of associated prefixes.. 825 */ 826 checklink = 1; 827 } 828 } else { 829 int llchange; 830 831 /* 832 * Check if the link-layer address has changed or not. 833 */ 834 if (lladdr == NULL) 835 llchange = 0; 836 else { 837 if (ln->la_flags & LLE_VALID) { 838 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 839 llchange = 1; 840 else 841 llchange = 0; 842 } else 843 llchange = 1; 844 } 845 846 /* 847 * This is VERY complex. Look at it with care. 848 * 849 * override solicit lladdr llchange action 850 * (L: record lladdr) 851 * 852 * 0 0 n -- (2c) 853 * 0 0 y n (2b) L 854 * 0 0 y y (1) REACHABLE->STALE 855 * 0 1 n -- (2c) *->REACHABLE 856 * 0 1 y n (2b) L *->REACHABLE 857 * 0 1 y y (1) REACHABLE->STALE 858 * 1 0 n -- (2a) 859 * 1 0 y n (2a) L 860 * 1 0 y y (2a) L *->STALE 861 * 1 1 n -- (2a) *->REACHABLE 862 * 1 1 y n (2a) L *->REACHABLE 863 * 1 1 y y (2a) L *->REACHABLE 864 */ 865 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 866 /* 867 * If state is REACHABLE, make it STALE. 868 * no other updates should be done. 869 */ 870 if (ln->ln_state == ND6_LLINFO_REACHABLE) 871 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 872 goto freeit; 873 } else if (is_override /* (2a) */ 874 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 875 || lladdr == NULL) { /* (2c) */ 876 /* 877 * Update link-local address, if any. 878 */ 879 if (lladdr != NULL) { 880 linkhdrsize = sizeof(linkhdr); 881 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 882 linkhdr, &linkhdrsize, &lladdr_off) != 0) 883 goto freeit; 884 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 885 linkhdrsize, lladdr_off) == 0) 886 goto freeit; 887 EVENTHANDLER_INVOKE(lle_event, ln, 888 LLENTRY_RESOLVED); 889 } 890 891 /* 892 * If solicited, make the state REACHABLE. 893 * If not solicited and the link-layer address was 894 * changed, make it STALE. 895 */ 896 if (is_solicited) 897 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 898 else { 899 if (lladdr != NULL && llchange) 900 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 901 } 902 } 903 904 if (ln->ln_router && !is_router) { 905 /* 906 * The peer dropped the router flag. 907 * Remove the sender from the Default Router List and 908 * update the Destination Cache entries. 909 */ 910 struct ifnet *nd6_ifp; 911 912 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 913 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 914 (ND_IFINFO(nd6_ifp)->flags & 915 ND6_IFF_ACCEPT_RTADV) != 0) 916 /* 917 * Even if the neighbor is not in the default 918 * router list, the neighbor may be used as a 919 * next hop for some destinations (e.g. redirect 920 * case). So we must call rt6_flush explicitly. 921 */ 922 rt6_flush(&ip6->ip6_src, ifp); 923 } 924 ln->ln_router = is_router; 925 } 926 /* XXX - QL 927 * Does this matter? 928 * rt->rt_flags &= ~RTF_REJECT; 929 */ 930 ln->la_asked = 0; 931 if (ln->la_hold != NULL) 932 chain = nd6_grab_holdchain(ln); 933 freeit: 934 if (ln != NULL) 935 LLE_WUNLOCK(ln); 936 937 if (chain != NULL) 938 nd6_flush_holdchain(ifp, ln, chain); 939 if (flush_holdchain) 940 nd6_flush_children_holdchain(ifp, ln); 941 942 if (checklink) 943 pfxlist_onlink_check(); 944 945 m_freem(m); 946 return; 947 948 bad: 949 if (ln != NULL) 950 LLE_WUNLOCK(ln); 951 952 ICMP6STAT_INC(icp6s_badna); 953 m_freem(m); 954 } 955 956 /* 957 * Neighbor advertisement output handling. 958 * 959 * Based on RFC 2461 960 * 961 * the following items are not implemented yet: 962 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 963 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 964 * 965 * tlladdr: 966 * - 0x01 if include target link-layer address 967 * - 0x02 if target address is CARP MASTER 968 * sdl0 - sockaddr_dl (= proxy NA) or NULL 969 */ 970 static void 971 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 972 const struct in6_addr *taddr6, u_long flags, int tlladdr, 973 struct sockaddr *sdl0, u_int fibnum) 974 { 975 struct mbuf *m; 976 struct m_tag *mtag; 977 struct ip6_hdr *ip6; 978 struct nd_neighbor_advert *nd_na; 979 struct ip6_moptions im6o; 980 struct in6_addr daddr6; 981 982 NET_EPOCH_ASSERT(); 983 984 int icmp6len, maxlen, error; 985 caddr_t mac = NULL; 986 987 daddr6 = *daddr6_0; /* make a local copy for modification */ 988 989 /* estimate the size of message */ 990 maxlen = sizeof(*ip6) + sizeof(*nd_na); 991 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 992 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 993 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 994 __func__, max_linkhdr, maxlen, MCLBYTES)); 995 996 if (max_linkhdr + maxlen > MHLEN) 997 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 998 else 999 m = m_gethdr(M_NOWAIT, MT_DATA); 1000 if (m == NULL) 1001 return; 1002 M_SETFIB(m, fibnum); 1003 1004 icmp6len = sizeof(*nd_na); 1005 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 1006 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 1007 1008 /* fill neighbor advertisement packet */ 1009 ip6 = mtod(m, struct ip6_hdr *); 1010 ip6->ip6_flow = 0; 1011 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 1012 ip6->ip6_vfc |= IPV6_VERSION; 1013 ip6->ip6_nxt = IPPROTO_ICMPV6; 1014 ip6->ip6_hlim = 255; 1015 1016 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 1017 /* reply to DAD */ 1018 daddr6 = in6addr_linklocal_allnodes; 1019 if (in6_setscope(&daddr6, ifp, NULL)) 1020 goto bad; 1021 1022 flags &= ~ND_NA_FLAG_SOLICITED; 1023 } 1024 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 1025 m->m_flags |= M_MCAST; 1026 im6o.im6o_multicast_ifp = ifp; 1027 im6o.im6o_multicast_hlim = 255; 1028 im6o.im6o_multicast_loop = 0; 1029 } 1030 1031 ip6->ip6_dst = daddr6; 1032 error = in6_selectsrc_nbr(fibnum, &daddr6, &im6o, ifp, &ip6->ip6_src); 1033 if (error) { 1034 char ip6buf[INET6_ADDRSTRLEN]; 1035 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1036 "determined: dst=%s, error=%d\n", 1037 ip6_sprintf(ip6buf, &daddr6), error)); 1038 goto bad; 1039 } 1040 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1041 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1042 nd_na->nd_na_code = 0; 1043 nd_na->nd_na_target = *taddr6; 1044 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1045 1046 /* 1047 * If we respond from CARP address, we need to prepare mac address 1048 * for carp_output(). 1049 */ 1050 if (ifp->if_carp && (tlladdr & ND6_NA_CARP_MASTER)) 1051 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1052 /* 1053 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1054 * see nd6_ns_input() for details. 1055 * Basically, if NS packet is sent to unicast/anycast addr, 1056 * target lladdr option SHOULD NOT be included. 1057 */ 1058 if (tlladdr & ND6_NA_OPT_LLA) { 1059 /* 1060 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1061 * lladdr in sdl0. If we are not proxying (sending NA for 1062 * my address) use lladdr configured for the interface. 1063 */ 1064 if (sdl0 == NULL) { 1065 if (mac == NULL) 1066 mac = nd6_ifptomac(ifp); 1067 } else if (sdl0->sa_family == AF_LINK) { 1068 struct sockaddr_dl *sdl; 1069 sdl = (struct sockaddr_dl *)sdl0; 1070 if (sdl->sdl_alen == ifp->if_addrlen) 1071 mac = LLADDR(sdl); 1072 } 1073 } 1074 if ((tlladdr & ND6_NA_OPT_LLA) && mac != NULL) { 1075 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1076 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1077 1078 /* roundup to 8 bytes alignment! */ 1079 optlen = (optlen + 7) & ~7; 1080 1081 m->m_pkthdr.len += optlen; 1082 m->m_len += optlen; 1083 icmp6len += optlen; 1084 bzero((caddr_t)nd_opt, optlen); 1085 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1086 nd_opt->nd_opt_len = optlen >> 3; 1087 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1088 } else 1089 flags &= ~ND_NA_FLAG_OVERRIDE; 1090 1091 ip6->ip6_plen = htons((u_short)icmp6len); 1092 nd_na->nd_na_flags_reserved = flags; 1093 nd_na->nd_na_cksum = 0; 1094 nd_na->nd_na_cksum = 1095 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1096 1097 if (send_sendso_input_hook != NULL) { 1098 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1099 sizeof(unsigned short), M_NOWAIT); 1100 if (mtag == NULL) 1101 goto bad; 1102 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1103 m_tag_prepend(m, mtag); 1104 } 1105 1106 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1107 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1108 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1109 ICMP6STAT_INC2(icp6s_outhist, ND_NEIGHBOR_ADVERT); 1110 1111 return; 1112 1113 bad: 1114 m_freem(m); 1115 } 1116 1117 #ifndef BURN_BRIDGES 1118 void 1119 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1120 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1121 struct sockaddr *sdl0) 1122 { 1123 1124 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1125 RT_DEFAULT_FIB); 1126 } 1127 #endif 1128 1129 caddr_t 1130 nd6_ifptomac(struct ifnet *ifp) 1131 { 1132 switch (ifp->if_type) { 1133 case IFT_ETHER: 1134 case IFT_IEEE1394: 1135 case IFT_L2VLAN: 1136 case IFT_INFINIBAND: 1137 case IFT_BRIDGE: 1138 return IF_LLADDR(ifp); 1139 default: 1140 return NULL; 1141 } 1142 } 1143 1144 struct dadq { 1145 TAILQ_ENTRY(dadq) dad_list; 1146 struct ifaddr *dad_ifa; 1147 int dad_count; /* max NS to send */ 1148 int dad_ns_tcount; /* # of trials to send NS */ 1149 int dad_ns_ocount; /* NS sent so far */ 1150 int dad_ns_icount; 1151 int dad_na_icount; 1152 int dad_ns_lcount; /* looped back NS */ 1153 int dad_loopbackprobe; /* probing state for loopback detection */ 1154 struct callout dad_timer_ch; 1155 struct vnet *dad_vnet; 1156 u_int dad_refcnt; 1157 #define ND_OPT_NONCE_LEN32 \ 1158 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1159 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1160 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */ 1161 }; 1162 1163 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq); 1164 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock); 1165 #define V_dadq VNET(dadq) 1166 #define V_dad_rwlock VNET(dad_rwlock) 1167 1168 #define DADQ_LOCKPTR() (&V_dad_rwlock) 1169 #define DADQ_LOCK_INIT() rw_init(DADQ_LOCKPTR(), "nd6 DAD queue") 1170 #define DADQ_RLOCK() rw_rlock(DADQ_LOCKPTR()) 1171 #define DADQ_RUNLOCK() rw_runlock(DADQ_LOCKPTR()) 1172 #define DADQ_WLOCK() rw_wlock(DADQ_LOCKPTR()) 1173 #define DADQ_WUNLOCK() rw_wunlock(DADQ_LOCKPTR()) 1174 1175 #define DADQ_LOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_LOCKED); 1176 #define DADQ_RLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_RLOCKED); 1177 #define DADQ_WLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_WLOCKED); 1178 1179 static void 1180 nd6_dad_add(struct dadq *dp) 1181 { 1182 DADQ_WLOCK_ASSERT(); 1183 1184 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1185 dp->dad_ondadq = true; 1186 } 1187 1188 static void 1189 nd6_dad_del(struct dadq *dp) 1190 { 1191 DADQ_WLOCK_ASSERT(); 1192 1193 if (dp->dad_ondadq) { 1194 /* 1195 * Remove dp from the dadq and release the dadq's 1196 * reference. 1197 */ 1198 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1199 dp->dad_ondadq = false; 1200 nd6_dad_rele(dp); 1201 } 1202 } 1203 1204 static struct dadq * 1205 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1206 { 1207 struct dadq *dp; 1208 1209 DADQ_LOCK_ASSERT(); 1210 1211 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1212 if (dp->dad_ifa != ifa) 1213 continue; 1214 1215 /* 1216 * Skip if the nonce matches the received one. 1217 * +2 in the length is required because of type and 1218 * length fields are included in a header. 1219 */ 1220 if (n != NULL && 1221 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1222 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1223 ND_OPT_NONCE_LEN) == 0) { 1224 dp->dad_ns_lcount++; 1225 continue; 1226 } 1227 break; 1228 } 1229 1230 return (dp); 1231 } 1232 1233 static void 1234 nd6_dad_starttimer(struct dadq *dp, int ticks) 1235 { 1236 DADQ_WLOCK_ASSERT(); 1237 1238 callout_reset(&dp->dad_timer_ch, ticks, nd6_dad_timer, dp); 1239 } 1240 1241 static void 1242 nd6_dad_stoptimer(struct dadq *dp) 1243 { 1244 callout_drain(&dp->dad_timer_ch); 1245 } 1246 1247 static void 1248 nd6_dad_rele(struct dadq *dp) 1249 { 1250 if (refcount_release(&dp->dad_refcnt)) { 1251 KASSERT(!dp->dad_ondadq, ("dp %p still on DAD queue", dp)); 1252 ifa_free(dp->dad_ifa); 1253 free(dp, M_IP6NDP); 1254 } 1255 } 1256 1257 void 1258 nd6_dad_init(void) 1259 { 1260 DADQ_LOCK_INIT(); 1261 TAILQ_INIT(&V_dadq); 1262 } 1263 1264 /* 1265 * Start Duplicate Address Detection (DAD) for specified interface address. 1266 */ 1267 void 1268 nd6_dad_start(struct ifaddr *ifa, int delay) 1269 { 1270 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1271 struct dadq *dp; 1272 char ip6buf[INET6_ADDRSTRLEN]; 1273 1274 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0, 1275 ("starting DAD on non-tentative address %p", ifa)); 1276 1277 /* 1278 * If we don't need DAD, don't do it. 1279 * There are several cases: 1280 * - DAD is disabled globally or on the interface 1281 * - the interface address is anycast 1282 */ 1283 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 || 1284 V_ip6_dad_count == 0 || 1285 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) != 0) { 1286 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1287 return; 1288 } 1289 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 || 1290 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || 1291 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) != 0) 1292 return; 1293 1294 DADQ_WLOCK(); 1295 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1296 /* 1297 * DAD is already in progress. Let the existing entry 1298 * finish it. 1299 */ 1300 DADQ_WUNLOCK(); 1301 return; 1302 } 1303 1304 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1305 if (dp == NULL) { 1306 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1307 "%s(%s)\n", 1308 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1309 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1310 return; 1311 } 1312 callout_init_rw(&dp->dad_timer_ch, DADQ_LOCKPTR(), 1313 CALLOUT_RETURNUNLOCKED); 1314 #ifdef VIMAGE 1315 dp->dad_vnet = curvnet; 1316 #endif 1317 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1318 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1319 1320 /* 1321 * Send NS packet for DAD, ip6_dad_count times. 1322 * Note that we must delay the first transmission, if this is the 1323 * first packet to be sent from the interface after interface 1324 * (re)initialization. 1325 */ 1326 dp->dad_ifa = ifa; 1327 ifa_ref(dp->dad_ifa); 1328 dp->dad_count = V_ip6_dad_count; 1329 dp->dad_ns_icount = dp->dad_na_icount = 0; 1330 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1331 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1332 1333 /* Add this to the dadq and add a reference for the dadq. */ 1334 refcount_init(&dp->dad_refcnt, 1); 1335 nd6_dad_add(dp); 1336 nd6_dad_starttimer(dp, delay); 1337 DADQ_WUNLOCK(); 1338 } 1339 1340 /* 1341 * terminate DAD unconditionally. used for address removals. 1342 */ 1343 void 1344 nd6_dad_stop(struct ifaddr *ifa) 1345 { 1346 struct dadq *dp; 1347 1348 DADQ_WLOCK(); 1349 dp = nd6_dad_find(ifa, NULL); 1350 if (dp == NULL) { 1351 DADQ_WUNLOCK(); 1352 /* DAD wasn't started yet */ 1353 return; 1354 } 1355 1356 /* 1357 * Acquire a temporary reference so that we can safely stop the callout. 1358 */ 1359 (void)refcount_acquire(&dp->dad_refcnt); 1360 nd6_dad_del(dp); 1361 DADQ_WUNLOCK(); 1362 1363 nd6_dad_stoptimer(dp); 1364 nd6_dad_rele(dp); 1365 } 1366 1367 static void 1368 nd6_dad_timer(void *arg) 1369 { 1370 struct dadq *dp = arg; 1371 struct ifaddr *ifa = dp->dad_ifa; 1372 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1373 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1374 char ip6buf[INET6_ADDRSTRLEN]; 1375 struct epoch_tracker et; 1376 1377 CURVNET_SET(dp->dad_vnet); 1378 KASSERT(ia != NULL, ("DAD entry %p with no address", dp)); 1379 1380 NET_EPOCH_ENTER(et); 1381 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1382 /* Do not need DAD for ifdisabled interface. */ 1383 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1384 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1385 goto err; 1386 } 1387 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1388 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1389 "%s(%s)\n", 1390 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1391 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1392 goto err; 1393 } 1394 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1395 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1396 "%s(%s)\n", 1397 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1398 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1399 goto err; 1400 } 1401 1402 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1403 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1404 (((ifp->if_flags & IFF_UP) == 0) || 1405 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1406 nd6log((LOG_INFO, "%s: could not run DAD " 1407 "because the interface was down or not running.\n", 1408 if_name(ifa->ifa_ifp))); 1409 goto err; 1410 } 1411 1412 /* Need more checks? */ 1413 if (dp->dad_ns_ocount < dp->dad_count) { 1414 /* 1415 * We have more NS to go. Send NS packet for DAD. 1416 */ 1417 nd6_dad_starttimer(dp, 1418 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1419 nd6_dad_ns_output(dp); 1420 goto done; 1421 } else { 1422 /* 1423 * We have transmitted sufficient number of DAD packets. 1424 * See what we've got. 1425 */ 1426 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) { 1427 /* We've seen NS or NA, means DAD has failed. */ 1428 nd6_dad_duplicated(ifa, dp); 1429 } else if (V_dad_enhanced != 0 && 1430 dp->dad_ns_lcount > 0 && 1431 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1432 /* 1433 * Sec. 4.1 in RFC 7527 requires transmission of 1434 * additional probes until the loopback condition 1435 * becomes clear when a looped back probe is detected. 1436 */ 1437 log(LOG_ERR, "%s: a looped back NS message is " 1438 "detected during DAD for %s. " 1439 "Another DAD probes are being sent.\n", 1440 if_name(ifa->ifa_ifp), 1441 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1442 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1443 /* 1444 * Send an NS immediately and increase dad_count by 1445 * V_nd6_mmaxtries - 1. 1446 */ 1447 dp->dad_count = 1448 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1449 nd6_dad_starttimer(dp, 1450 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1451 nd6_dad_ns_output(dp); 1452 goto done; 1453 } else { 1454 /* 1455 * We are done with DAD. No NA came, no NS came. 1456 * No duplicate address found. Check IFDISABLED flag 1457 * again in case that it is changed between the 1458 * beginning of this function and here. 1459 * 1460 * Reset DAD failures counter if using stable addresses. 1461 */ 1462 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) { 1463 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1464 if ((ND_IFINFO(ifp)->flags & ND6_IFF_STABLEADDR) && !(ia->ia6_flags & IN6_IFF_TEMPORARY)) 1465 atomic_store_int(&DAD_FAILURES(ifp), 0); 1466 } 1467 1468 nd6log((LOG_DEBUG, 1469 "%s: DAD complete for %s - no duplicates found\n", 1470 if_name(ifa->ifa_ifp), 1471 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1472 if (dp->dad_ns_lcount > 0) 1473 log(LOG_ERR, "%s: DAD completed while " 1474 "a looped back NS message is detected " 1475 "during DAD for %s.\n", 1476 if_name(ifa->ifa_ifp), 1477 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1478 } 1479 } 1480 err: 1481 nd6_dad_del(dp); 1482 DADQ_WUNLOCK(); 1483 done: 1484 NET_EPOCH_EXIT(et); 1485 CURVNET_RESTORE(); 1486 } 1487 1488 static void 1489 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1490 { 1491 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1492 struct ifnet *ifp; 1493 char ip6buf[INET6_ADDRSTRLEN]; 1494 1495 ifp = ifa->ifa_ifp; 1496 1497 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1498 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1499 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1500 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1501 dp->dad_na_icount); 1502 1503 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1504 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1505 1506 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1507 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1508 1509 /* 1510 * For RFC 7217 stable addresses, increment failure counter here if we still have retries. 1511 * More addresses will be generated as long as retries are not exhausted. 1512 */ 1513 if ((ND_IFINFO(ifp)->flags & ND6_IFF_STABLEADDR) && !(ia->ia6_flags & IN6_IFF_TEMPORARY)) { 1514 u_int dad_failures = atomic_load_int(&DAD_FAILURES(ifp)); 1515 1516 if (dad_failures <= V_ip6_stableaddr_maxretries) { 1517 atomic_add_int(&DAD_FAILURES(ifp), 1); 1518 /* if retries exhausted, output an informative error message */ 1519 if (dad_failures == V_ip6_stableaddr_maxretries) 1520 log(LOG_ERR, "%s: manual intervention required, consider disabling \"stableaddr\" on the interface" 1521 " or checking hostuuid for uniqueness\n", 1522 if_name(ifp)); 1523 } 1524 } else { 1525 log(LOG_ERR, "%s: manual intervention required\n", 1526 if_name(ifp)); 1527 } 1528 1529 /* 1530 * If the address is a link-local address formed from an interface 1531 * identifier based on the hardware address which is supposed to be 1532 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1533 * operation on the interface SHOULD be disabled. 1534 * [RFC 4862, Section 5.4.5] 1535 */ 1536 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1537 struct in6_addr in6; 1538 1539 /* 1540 * To avoid over-reaction, we only apply this logic when we are 1541 * very sure that hardware addresses are supposed to be unique. 1542 */ 1543 switch (ifp->if_type) { 1544 case IFT_ETHER: 1545 case IFT_ATM: 1546 case IFT_IEEE1394: 1547 case IFT_INFINIBAND: 1548 in6 = ia->ia_addr.sin6_addr; 1549 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1550 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1551 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1552 log(LOG_ERR, "%s: possible hardware address " 1553 "duplication detected, disable IPv6\n", 1554 if_name(ifp)); 1555 } 1556 break; 1557 } 1558 } 1559 } 1560 1561 /* 1562 * Transmit a neighbour solicitation for the purpose of DAD. Returns with the 1563 * DAD queue unlocked. 1564 */ 1565 static void 1566 nd6_dad_ns_output(struct dadq *dp) 1567 { 1568 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1569 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1570 int i; 1571 1572 DADQ_WLOCK_ASSERT(); 1573 1574 dp->dad_ns_tcount++; 1575 if ((ifp->if_flags & IFF_UP) == 0) { 1576 DADQ_WUNLOCK(); 1577 return; 1578 } 1579 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1580 DADQ_WUNLOCK(); 1581 return; 1582 } 1583 1584 dp->dad_ns_ocount++; 1585 if (V_dad_enhanced != 0) { 1586 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1587 dp->dad_nonce[i] = arc4random(); 1588 /* 1589 * XXXHRS: Note that in the case that 1590 * DupAddrDetectTransmits > 1, multiple NS messages with 1591 * different nonces can be looped back in an unexpected 1592 * order. The current implementation recognizes only 1593 * the latest nonce on the sender side. Practically it 1594 * should work well in almost all cases. 1595 */ 1596 } 1597 DADQ_WUNLOCK(); 1598 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1599 (uint8_t *)&dp->dad_nonce[0]); 1600 } 1601 1602 static void 1603 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1604 { 1605 struct dadq *dp; 1606 1607 if (ifa == NULL) 1608 panic("ifa == NULL in nd6_dad_ns_input"); 1609 1610 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1611 if (V_dad_enhanced == 0) 1612 ndopt_nonce = NULL; 1613 DADQ_RLOCK(); 1614 dp = nd6_dad_find(ifa, ndopt_nonce); 1615 if (dp != NULL) 1616 dp->dad_ns_icount++; 1617 DADQ_RUNLOCK(); 1618 } 1619 1620 static void 1621 nd6_dad_na_input(struct ifaddr *ifa) 1622 { 1623 struct dadq *dp; 1624 1625 if (ifa == NULL) 1626 panic("ifa == NULL in nd6_dad_na_input"); 1627 1628 DADQ_RLOCK(); 1629 dp = nd6_dad_find(ifa, NULL); 1630 if (dp != NULL) 1631 dp->dad_na_icount++; 1632 DADQ_RUNLOCK(); 1633 } 1634