1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $ 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 #include "opt_ipsec.h" 40 #include "opt_mpath.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/eventhandler.h> 45 #include <sys/malloc.h> 46 #include <sys/libkern.h> 47 #include <sys/lock.h> 48 #include <sys/rwlock.h> 49 #include <sys/mbuf.h> 50 #include <sys/socket.h> 51 #include <sys/sockio.h> 52 #include <sys/time.h> 53 #include <sys/kernel.h> 54 #include <sys/errno.h> 55 #include <sys/sysctl.h> 56 #include <sys/syslog.h> 57 #include <sys/queue.h> 58 #include <sys/callout.h> 59 #include <sys/refcount.h> 60 61 #include <net/if.h> 62 #include <net/if_types.h> 63 #include <net/if_dl.h> 64 #include <net/if_var.h> 65 #include <net/route.h> 66 #ifdef RADIX_MPATH 67 #include <net/radix_mpath.h> 68 #endif 69 #include <net/vnet.h> 70 71 #include <netinet/in.h> 72 #include <netinet/in_var.h> 73 #include <net/if_llatbl.h> 74 #include <netinet6/in6_var.h> 75 #include <netinet6/in6_ifattach.h> 76 #include <netinet/ip6.h> 77 #include <netinet6/ip6_var.h> 78 #include <netinet6/scope6_var.h> 79 #include <netinet6/nd6.h> 80 #include <netinet/icmp6.h> 81 #include <netinet/ip_carp.h> 82 #include <netinet6/send.h> 83 84 #define SDL(s) ((struct sockaddr_dl *)s) 85 86 struct dadq; 87 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *); 88 static void nd6_dad_add(struct dadq *dp); 89 static void nd6_dad_del(struct dadq *dp); 90 static void nd6_dad_rele(struct dadq *); 91 static void nd6_dad_starttimer(struct dadq *, int, int); 92 static void nd6_dad_stoptimer(struct dadq *); 93 static void nd6_dad_timer(struct dadq *); 94 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *); 95 static void nd6_dad_ns_output(struct dadq *); 96 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *); 97 static void nd6_dad_na_input(struct ifaddr *); 98 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 99 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 100 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *, 101 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int); 102 103 VNET_DEFINE_STATIC(int, dad_enhanced) = 1; 104 #define V_dad_enhanced VNET(dad_enhanced) 105 106 SYSCTL_DECL(_net_inet6_ip6); 107 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW, 108 &VNET_NAME(dad_enhanced), 0, 109 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD."); 110 111 VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to 112 transmit DAD packet */ 113 #define V_dad_maxtry VNET(dad_maxtry) 114 115 /* 116 * Input a Neighbor Solicitation Message. 117 * 118 * Based on RFC 2461 119 * Based on RFC 2462 (duplicate address detection) 120 */ 121 void 122 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 123 { 124 struct ifnet *ifp; 125 struct ip6_hdr *ip6; 126 struct nd_neighbor_solicit *nd_ns; 127 struct in6_addr daddr6, myaddr6, saddr6, taddr6; 128 struct ifaddr *ifa; 129 struct sockaddr_dl proxydl; 130 union nd_opts ndopts; 131 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 132 char *lladdr; 133 int anycast, lladdrlen, proxy, rflag, tentative, tlladdr; 134 135 ifa = NULL; 136 137 /* RFC 6980: Nodes MUST silently ignore fragments */ 138 if(m->m_flags & M_FRAGMENTED) 139 goto freeit; 140 141 ifp = m->m_pkthdr.rcvif; 142 ip6 = mtod(m, struct ip6_hdr *); 143 if (ip6->ip6_hlim != 255) { 144 nd6log((LOG_ERR, 145 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 146 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 147 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 148 goto bads; 149 } 150 151 m = m_pullup(m, off + icmp6len); 152 if (m == NULL) { 153 IP6STAT_INC(ip6s_exthdrtoolong); 154 return; 155 } 156 ip6 = mtod(m, struct ip6_hdr *); 157 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 158 159 saddr6 = ip6->ip6_src; 160 daddr6 = ip6->ip6_dst; 161 taddr6 = nd_ns->nd_ns_target; 162 if (in6_setscope(&taddr6, ifp, NULL) != 0) 163 goto bad; 164 165 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 166 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 167 rflag = 0; 168 169 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 170 /* dst has to be a solicited node multicast address. */ 171 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 172 /* don't check ifindex portion */ 173 daddr6.s6_addr32[1] == 0 && 174 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 175 daddr6.s6_addr8[12] == 0xff) { 176 ; /* good */ 177 } else { 178 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 179 "(wrong ip6 dst)\n")); 180 goto bad; 181 } 182 } else if (!V_nd6_onlink_ns_rfc4861) { 183 struct sockaddr_in6 src_sa6; 184 185 /* 186 * According to recent IETF discussions, it is not a good idea 187 * to accept a NS from an address which would not be deemed 188 * to be a neighbor otherwise. This point is expected to be 189 * clarified in future revisions of the specification. 190 */ 191 bzero(&src_sa6, sizeof(src_sa6)); 192 src_sa6.sin6_family = AF_INET6; 193 src_sa6.sin6_len = sizeof(src_sa6); 194 src_sa6.sin6_addr = saddr6; 195 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 196 nd6log((LOG_INFO, "nd6_ns_input: " 197 "NS packet from non-neighbor\n")); 198 goto bad; 199 } 200 } 201 202 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 203 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 204 goto bad; 205 } 206 207 icmp6len -= sizeof(*nd_ns); 208 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 209 if (nd6_options(&ndopts) < 0) { 210 nd6log((LOG_INFO, 211 "nd6_ns_input: invalid ND option, ignored\n")); 212 /* nd6_options have incremented stats */ 213 goto freeit; 214 } 215 216 lladdr = NULL; 217 lladdrlen = 0; 218 if (ndopts.nd_opts_src_lladdr) { 219 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 220 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 221 } 222 223 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 224 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 225 "(link-layer address option)\n")); 226 goto bad; 227 } 228 229 /* 230 * Attaching target link-layer address to the NA? 231 * (RFC 2461 7.2.4) 232 * 233 * NS IP dst is unicast/anycast MUST NOT add 234 * NS IP dst is solicited-node multicast MUST add 235 * 236 * In implementation, we add target link-layer address by default. 237 * We do not add one in MUST NOT cases. 238 */ 239 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 240 tlladdr = 0; 241 else 242 tlladdr = 1; 243 244 /* 245 * Target address (taddr6) must be either: 246 * (1) Valid unicast/anycast address for my receiving interface, 247 * (2) Unicast address for which I'm offering proxy service, or 248 * (3) "tentative" address on which DAD is being performed. 249 */ 250 /* (1) and (3) check. */ 251 if (ifp->if_carp) 252 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 253 else 254 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 255 256 /* (2) check. */ 257 proxy = 0; 258 if (ifa == NULL) { 259 struct sockaddr_dl rt_gateway; 260 struct rt_addrinfo info; 261 struct sockaddr_in6 dst6; 262 263 bzero(&dst6, sizeof(dst6)); 264 dst6.sin6_len = sizeof(struct sockaddr_in6); 265 dst6.sin6_family = AF_INET6; 266 dst6.sin6_addr = taddr6; 267 268 bzero(&rt_gateway, sizeof(rt_gateway)); 269 rt_gateway.sdl_len = sizeof(rt_gateway); 270 bzero(&info, sizeof(info)); 271 info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway; 272 273 if (rib_lookup_info(ifp->if_fib, (struct sockaddr *)&dst6, 274 0, 0, &info) == 0) { 275 if ((info.rti_flags & RTF_ANNOUNCE) != 0 && 276 rt_gateway.sdl_family == AF_LINK) { 277 278 /* 279 * proxy NDP for single entry 280 */ 281 proxydl = *SDL(&rt_gateway); 282 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal( 283 ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 284 if (ifa) 285 proxy = 1; 286 } 287 } 288 } 289 if (ifa == NULL) { 290 /* 291 * We've got an NS packet, and we don't have that adddress 292 * assigned for us. We MUST silently ignore it. 293 * See RFC2461 7.2.3. 294 */ 295 goto freeit; 296 } 297 myaddr6 = *IFA_IN6(ifa); 298 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 299 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 300 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 301 goto freeit; 302 303 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 304 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 305 "(if %d, NS packet %d)\n", 306 ip6_sprintf(ip6bufs, &taddr6), 307 ifp->if_addrlen, lladdrlen - 2)); 308 goto bad; 309 } 310 311 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 312 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 313 ip6_sprintf(ip6bufs, &saddr6))); 314 goto freeit; 315 } 316 317 /* 318 * We have neighbor solicitation packet, with target address equals to 319 * one of my tentative address. 320 * 321 * src addr how to process? 322 * --- --- 323 * multicast of course, invalid (rejected in ip6_input) 324 * unicast somebody is doing address resolution -> ignore 325 * unspec dup address detection 326 * 327 * The processing is defined in RFC 2462. 328 */ 329 if (tentative) { 330 /* 331 * If source address is unspecified address, it is for 332 * duplicate address detection. 333 * 334 * If not, the packet is for addess resolution; 335 * silently ignore it. 336 */ 337 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 338 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 339 340 goto freeit; 341 } 342 343 /* 344 * If the source address is unspecified address, entries must not 345 * be created or updated. 346 * It looks that sender is performing DAD. Output NA toward 347 * all-node multicast address, to tell the sender that I'm using 348 * the address. 349 * S bit ("solicited") must be zero. 350 */ 351 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 352 struct in6_addr in6_all; 353 354 in6_all = in6addr_linklocal_allnodes; 355 if (in6_setscope(&in6_all, ifp, NULL) != 0) 356 goto bad; 357 nd6_na_output_fib(ifp, &in6_all, &taddr6, 358 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 359 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 360 M_GETFIB(m)); 361 goto freeit; 362 } 363 364 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 365 ND_NEIGHBOR_SOLICIT, 0); 366 367 nd6_na_output_fib(ifp, &saddr6, &taddr6, 368 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 369 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 370 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 371 freeit: 372 if (ifa != NULL) 373 ifa_free(ifa); 374 m_freem(m); 375 return; 376 377 bad: 378 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 379 ip6_sprintf(ip6bufs, &saddr6))); 380 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 381 ip6_sprintf(ip6bufs, &daddr6))); 382 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 383 ip6_sprintf(ip6bufs, &taddr6))); 384 bads: 385 ICMP6STAT_INC(icp6s_badns); 386 if (ifa != NULL) 387 ifa_free(ifa); 388 m_freem(m); 389 } 390 391 /* 392 * Output a Neighbor Solicitation Message. Caller specifies: 393 * - ICMP6 header source IP6 address 394 * - ND6 header target IP6 address 395 * - ND6 header source datalink address 396 * 397 * Based on RFC 2461 398 * Based on RFC 2462 (duplicate address detection) 399 * 400 * ln - for source address determination 401 * nonce - If non-NULL, NS is used for duplicate address detection and 402 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 403 */ 404 static void 405 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 406 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 407 uint8_t *nonce, u_int fibnum) 408 { 409 struct mbuf *m; 410 struct m_tag *mtag; 411 struct ip6_hdr *ip6; 412 struct nd_neighbor_solicit *nd_ns; 413 struct ip6_moptions im6o; 414 int icmp6len; 415 int maxlen; 416 caddr_t mac; 417 418 if (IN6_IS_ADDR_MULTICAST(taddr6)) 419 return; 420 421 /* estimate the size of message */ 422 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 423 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 424 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 425 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 426 __func__, max_linkhdr, maxlen, MCLBYTES)); 427 428 if (max_linkhdr + maxlen > MHLEN) 429 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 430 else 431 m = m_gethdr(M_NOWAIT, MT_DATA); 432 if (m == NULL) 433 return; 434 M_SETFIB(m, fibnum); 435 436 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 437 m->m_flags |= M_MCAST; 438 im6o.im6o_multicast_ifp = ifp; 439 im6o.im6o_multicast_hlim = 255; 440 im6o.im6o_multicast_loop = 0; 441 } 442 443 icmp6len = sizeof(*nd_ns); 444 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 445 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 446 447 /* fill neighbor solicitation packet */ 448 ip6 = mtod(m, struct ip6_hdr *); 449 ip6->ip6_flow = 0; 450 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 451 ip6->ip6_vfc |= IPV6_VERSION; 452 /* ip6->ip6_plen will be set later */ 453 ip6->ip6_nxt = IPPROTO_ICMPV6; 454 ip6->ip6_hlim = 255; 455 if (daddr6) 456 ip6->ip6_dst = *daddr6; 457 else { 458 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 459 ip6->ip6_dst.s6_addr16[1] = 0; 460 ip6->ip6_dst.s6_addr32[1] = 0; 461 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 462 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 463 ip6->ip6_dst.s6_addr8[12] = 0xff; 464 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 465 goto bad; 466 } 467 if (nonce == NULL) { 468 struct ifaddr *ifa = NULL; 469 470 /* 471 * RFC2461 7.2.2: 472 * "If the source address of the packet prompting the 473 * solicitation is the same as one of the addresses assigned 474 * to the outgoing interface, that address SHOULD be placed 475 * in the IP Source Address of the outgoing solicitation. 476 * Otherwise, any one of the addresses assigned to the 477 * interface should be used." 478 * 479 * We use the source address for the prompting packet 480 * (saddr6), if saddr6 belongs to the outgoing interface. 481 * Otherwise, we perform the source address selection as usual. 482 */ 483 484 if (saddr6 != NULL) 485 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 486 if (ifa != NULL) { 487 /* ip6_src set already. */ 488 ip6->ip6_src = *saddr6; 489 ifa_free(ifa); 490 } else { 491 int error; 492 struct in6_addr dst6, src6; 493 uint32_t scopeid; 494 495 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); 496 error = in6_selectsrc_addr(fibnum, &dst6, 497 scopeid, ifp, &src6, NULL); 498 if (error) { 499 char ip6buf[INET6_ADDRSTRLEN]; 500 nd6log((LOG_DEBUG, "%s: source can't be " 501 "determined: dst=%s, error=%d\n", __func__, 502 ip6_sprintf(ip6buf, &dst6), 503 error)); 504 goto bad; 505 } 506 ip6->ip6_src = src6; 507 } 508 } else { 509 /* 510 * Source address for DAD packet must always be IPv6 511 * unspecified address. (0::0) 512 * We actually don't have to 0-clear the address (we did it 513 * above), but we do so here explicitly to make the intention 514 * clearer. 515 */ 516 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 517 } 518 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 519 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 520 nd_ns->nd_ns_code = 0; 521 nd_ns->nd_ns_reserved = 0; 522 nd_ns->nd_ns_target = *taddr6; 523 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 524 525 /* 526 * Add source link-layer address option. 527 * 528 * spec implementation 529 * --- --- 530 * DAD packet MUST NOT do not add the option 531 * there's no link layer address: 532 * impossible do not add the option 533 * there's link layer address: 534 * Multicast NS MUST add one add the option 535 * Unicast NS SHOULD add one add the option 536 */ 537 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 538 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 539 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 540 /* 8 byte alignments... */ 541 optlen = (optlen + 7) & ~7; 542 543 m->m_pkthdr.len += optlen; 544 m->m_len += optlen; 545 icmp6len += optlen; 546 bzero((caddr_t)nd_opt, optlen); 547 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 548 nd_opt->nd_opt_len = optlen >> 3; 549 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 550 } 551 /* 552 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 553 * This behavior is documented as Enhanced Duplicate Address 554 * Detection in RFC 7527. 555 * net.inet6.ip6.dad_enhanced=0 disables this. 556 */ 557 if (V_dad_enhanced != 0 && nonce != NULL) { 558 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 559 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 560 /* 8-byte alignment is required. */ 561 optlen = (optlen + 7) & ~7; 562 563 m->m_pkthdr.len += optlen; 564 m->m_len += optlen; 565 icmp6len += optlen; 566 bzero((caddr_t)nd_opt, optlen); 567 nd_opt->nd_opt_type = ND_OPT_NONCE; 568 nd_opt->nd_opt_len = optlen >> 3; 569 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 570 } 571 ip6->ip6_plen = htons((u_short)icmp6len); 572 nd_ns->nd_ns_cksum = 0; 573 nd_ns->nd_ns_cksum = 574 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 575 576 if (send_sendso_input_hook != NULL) { 577 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 578 sizeof(unsigned short), M_NOWAIT); 579 if (mtag == NULL) 580 goto bad; 581 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 582 m_tag_prepend(m, mtag); 583 } 584 585 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 586 &im6o, NULL, NULL); 587 icmp6_ifstat_inc(ifp, ifs6_out_msg); 588 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 589 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 590 591 return; 592 593 bad: 594 m_freem(m); 595 } 596 597 #ifndef BURN_BRIDGES 598 void 599 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 600 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 601 { 602 603 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 604 } 605 #endif 606 /* 607 * Neighbor advertisement input handling. 608 * 609 * Based on RFC 2461 610 * Based on RFC 2462 (duplicate address detection) 611 * 612 * the following items are not implemented yet: 613 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 614 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 615 */ 616 void 617 nd6_na_input(struct mbuf *m, int off, int icmp6len) 618 { 619 struct ifnet *ifp; 620 struct ip6_hdr *ip6; 621 struct ifaddr *ifa; 622 struct llentry *ln; 623 struct mbuf *chain; 624 struct nd_neighbor_advert *nd_na; 625 struct in6_addr daddr6, taddr6; 626 struct sockaddr_in6 sin6; 627 union nd_opts ndopts; 628 u_char linkhdr[LLE_MAX_LINKHDR]; 629 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 630 char *lladdr; 631 size_t linkhdrsize; 632 int flags, is_override, is_router, is_solicited; 633 int lladdr_off, lladdrlen, checklink; 634 635 NET_EPOCH_ASSERT(); 636 637 chain = NULL; 638 ln = NULL; 639 checklink = 0; 640 641 /* RFC 6980: Nodes MUST silently ignore fragments */ 642 if(m->m_flags & M_FRAGMENTED) 643 goto freeit; 644 645 ifp = m->m_pkthdr.rcvif; 646 ip6 = mtod(m, struct ip6_hdr *); 647 if (ip6->ip6_hlim != 255) { 648 nd6log((LOG_ERR, 649 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 650 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 651 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 652 goto bad; 653 } 654 655 m = m_pullup(m, off + icmp6len); 656 if (m == NULL) { 657 IP6STAT_INC(ip6s_exthdrtoolong); 658 return; 659 } 660 ip6 = mtod(m, struct ip6_hdr *); 661 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 662 663 flags = nd_na->nd_na_flags_reserved; 664 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 665 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 666 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 667 668 taddr6 = nd_na->nd_na_target; 669 if (in6_setscope(&taddr6, ifp, NULL)) 670 goto bad; /* XXX: impossible */ 671 672 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 673 nd6log((LOG_ERR, 674 "nd6_na_input: invalid target address %s\n", 675 ip6_sprintf(ip6bufs, &taddr6))); 676 goto bad; 677 } 678 679 daddr6 = ip6->ip6_dst; 680 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 681 if (is_solicited) { 682 nd6log((LOG_ERR, 683 "nd6_na_input: a solicited adv is multicasted\n")); 684 goto bad; 685 } 686 687 icmp6len -= sizeof(*nd_na); 688 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 689 if (nd6_options(&ndopts) < 0) { 690 nd6log((LOG_INFO, 691 "nd6_na_input: invalid ND option, ignored\n")); 692 /* nd6_options have incremented stats */ 693 goto freeit; 694 } 695 696 lladdr = NULL; 697 lladdrlen = 0; 698 if (ndopts.nd_opts_tgt_lladdr) { 699 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 700 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 701 } 702 703 /* 704 * This effectively disables the DAD check on a non-master CARP 705 * address. 706 */ 707 if (ifp->if_carp) 708 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 709 else 710 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 711 712 /* 713 * Target address matches one of my interface address. 714 * 715 * If my address is tentative, this means that there's somebody 716 * already using the same address as mine. This indicates DAD failure. 717 * This is defined in RFC 2462. 718 * 719 * Otherwise, process as defined in RFC 2461. 720 */ 721 if (ifa 722 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 723 nd6_dad_na_input(ifa); 724 ifa_free(ifa); 725 goto freeit; 726 } 727 728 /* Just for safety, maybe unnecessary. */ 729 if (ifa) { 730 ifa_free(ifa); 731 log(LOG_ERR, 732 "nd6_na_input: duplicate IP6 address %s\n", 733 ip6_sprintf(ip6bufs, &taddr6)); 734 goto freeit; 735 } 736 737 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 738 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 739 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 740 ifp->if_addrlen, lladdrlen - 2)); 741 goto bad; 742 } 743 744 /* 745 * If no neighbor cache entry is found, NA SHOULD silently be 746 * discarded. 747 */ 748 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 749 if (ln == NULL) { 750 goto freeit; 751 } 752 753 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 754 /* 755 * If the link-layer has address, and no lladdr option came, 756 * discard the packet. 757 */ 758 if (ifp->if_addrlen && lladdr == NULL) { 759 goto freeit; 760 } 761 762 /* 763 * Record link-layer address, and update the state. 764 */ 765 linkhdrsize = sizeof(linkhdr); 766 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 767 linkhdr, &linkhdrsize, &lladdr_off) != 0) 768 return; 769 770 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize, 771 lladdr_off) == 0) { 772 ln = NULL; 773 goto freeit; 774 } 775 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 776 if (is_solicited) 777 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 778 else 779 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 780 if ((ln->ln_router = is_router) != 0) { 781 /* 782 * This means a router's state has changed from 783 * non-reachable to probably reachable, and might 784 * affect the status of associated prefixes.. 785 */ 786 checklink = 1; 787 } 788 } else { 789 int llchange; 790 791 /* 792 * Check if the link-layer address has changed or not. 793 */ 794 if (lladdr == NULL) 795 llchange = 0; 796 else { 797 if (ln->la_flags & LLE_VALID) { 798 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 799 llchange = 1; 800 else 801 llchange = 0; 802 } else 803 llchange = 1; 804 } 805 806 /* 807 * This is VERY complex. Look at it with care. 808 * 809 * override solicit lladdr llchange action 810 * (L: record lladdr) 811 * 812 * 0 0 n -- (2c) 813 * 0 0 y n (2b) L 814 * 0 0 y y (1) REACHABLE->STALE 815 * 0 1 n -- (2c) *->REACHABLE 816 * 0 1 y n (2b) L *->REACHABLE 817 * 0 1 y y (1) REACHABLE->STALE 818 * 1 0 n -- (2a) 819 * 1 0 y n (2a) L 820 * 1 0 y y (2a) L *->STALE 821 * 1 1 n -- (2a) *->REACHABLE 822 * 1 1 y n (2a) L *->REACHABLE 823 * 1 1 y y (2a) L *->REACHABLE 824 */ 825 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 826 /* 827 * If state is REACHABLE, make it STALE. 828 * no other updates should be done. 829 */ 830 if (ln->ln_state == ND6_LLINFO_REACHABLE) 831 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 832 goto freeit; 833 } else if (is_override /* (2a) */ 834 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 835 || lladdr == NULL) { /* (2c) */ 836 /* 837 * Update link-local address, if any. 838 */ 839 if (lladdr != NULL) { 840 linkhdrsize = sizeof(linkhdr); 841 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 842 linkhdr, &linkhdrsize, &lladdr_off) != 0) 843 goto freeit; 844 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 845 linkhdrsize, lladdr_off) == 0) { 846 ln = NULL; 847 goto freeit; 848 } 849 EVENTHANDLER_INVOKE(lle_event, ln, 850 LLENTRY_RESOLVED); 851 } 852 853 /* 854 * If solicited, make the state REACHABLE. 855 * If not solicited and the link-layer address was 856 * changed, make it STALE. 857 */ 858 if (is_solicited) 859 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 860 else { 861 if (lladdr != NULL && llchange) 862 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 863 } 864 } 865 866 if (ln->ln_router && !is_router) { 867 /* 868 * The peer dropped the router flag. 869 * Remove the sender from the Default Router List and 870 * update the Destination Cache entries. 871 */ 872 struct ifnet *nd6_ifp; 873 874 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 875 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 876 (ND_IFINFO(nd6_ifp)->flags & 877 ND6_IFF_ACCEPT_RTADV) != 0) 878 /* 879 * Even if the neighbor is not in the default 880 * router list, the neighbor may be used as a 881 * next hop for some destinations (e.g. redirect 882 * case). So we must call rt6_flush explicitly. 883 */ 884 rt6_flush(&ip6->ip6_src, ifp); 885 } 886 ln->ln_router = is_router; 887 } 888 /* XXX - QL 889 * Does this matter? 890 * rt->rt_flags &= ~RTF_REJECT; 891 */ 892 ln->la_asked = 0; 893 if (ln->la_hold != NULL) { 894 memset(&sin6, 0, sizeof(sin6)); 895 nd6_grab_holdchain(ln, &chain, &sin6); 896 } 897 freeit: 898 if (ln != NULL) 899 LLE_WUNLOCK(ln); 900 901 if (chain != NULL) 902 nd6_flush_holdchain(ifp, chain, &sin6); 903 904 if (checklink) 905 pfxlist_onlink_check(); 906 907 m_freem(m); 908 return; 909 910 bad: 911 if (ln != NULL) 912 LLE_WUNLOCK(ln); 913 914 ICMP6STAT_INC(icp6s_badna); 915 m_freem(m); 916 } 917 918 /* 919 * Neighbor advertisement output handling. 920 * 921 * Based on RFC 2461 922 * 923 * the following items are not implemented yet: 924 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 925 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 926 * 927 * tlladdr - 1 if include target link-layer address 928 * sdl0 - sockaddr_dl (= proxy NA) or NULL 929 */ 930 static void 931 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 932 const struct in6_addr *taddr6, u_long flags, int tlladdr, 933 struct sockaddr *sdl0, u_int fibnum) 934 { 935 struct mbuf *m; 936 struct m_tag *mtag; 937 struct ip6_hdr *ip6; 938 struct nd_neighbor_advert *nd_na; 939 struct ip6_moptions im6o; 940 struct in6_addr daddr6, dst6, src6; 941 uint32_t scopeid; 942 943 int icmp6len, maxlen, error; 944 caddr_t mac = NULL; 945 946 daddr6 = *daddr6_0; /* make a local copy for modification */ 947 948 /* estimate the size of message */ 949 maxlen = sizeof(*ip6) + sizeof(*nd_na); 950 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 951 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 952 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 953 __func__, max_linkhdr, maxlen, MCLBYTES)); 954 955 if (max_linkhdr + maxlen > MHLEN) 956 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 957 else 958 m = m_gethdr(M_NOWAIT, MT_DATA); 959 if (m == NULL) 960 return; 961 M_SETFIB(m, fibnum); 962 963 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 964 m->m_flags |= M_MCAST; 965 im6o.im6o_multicast_ifp = ifp; 966 im6o.im6o_multicast_hlim = 255; 967 im6o.im6o_multicast_loop = 0; 968 } 969 970 icmp6len = sizeof(*nd_na); 971 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 972 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 973 974 /* fill neighbor advertisement packet */ 975 ip6 = mtod(m, struct ip6_hdr *); 976 ip6->ip6_flow = 0; 977 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 978 ip6->ip6_vfc |= IPV6_VERSION; 979 ip6->ip6_nxt = IPPROTO_ICMPV6; 980 ip6->ip6_hlim = 255; 981 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 982 /* reply to DAD */ 983 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 984 daddr6.s6_addr16[1] = 0; 985 daddr6.s6_addr32[1] = 0; 986 daddr6.s6_addr32[2] = 0; 987 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 988 if (in6_setscope(&daddr6, ifp, NULL)) 989 goto bad; 990 991 flags &= ~ND_NA_FLAG_SOLICITED; 992 } 993 ip6->ip6_dst = daddr6; 994 995 /* 996 * Select a source whose scope is the same as that of the dest. 997 */ 998 in6_splitscope(&daddr6, &dst6, &scopeid); 999 error = in6_selectsrc_addr(fibnum, &dst6, 1000 scopeid, ifp, &src6, NULL); 1001 if (error) { 1002 char ip6buf[INET6_ADDRSTRLEN]; 1003 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1004 "determined: dst=%s, error=%d\n", 1005 ip6_sprintf(ip6buf, &daddr6), error)); 1006 goto bad; 1007 } 1008 ip6->ip6_src = src6; 1009 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1010 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1011 nd_na->nd_na_code = 0; 1012 nd_na->nd_na_target = *taddr6; 1013 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1014 1015 /* 1016 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1017 * see nd6_ns_input() for details. 1018 * Basically, if NS packet is sent to unicast/anycast addr, 1019 * target lladdr option SHOULD NOT be included. 1020 */ 1021 if (tlladdr) { 1022 /* 1023 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1024 * lladdr in sdl0. If we are not proxying (sending NA for 1025 * my address) use lladdr configured for the interface. 1026 */ 1027 if (sdl0 == NULL) { 1028 if (ifp->if_carp) 1029 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1030 if (mac == NULL) 1031 mac = nd6_ifptomac(ifp); 1032 } else if (sdl0->sa_family == AF_LINK) { 1033 struct sockaddr_dl *sdl; 1034 sdl = (struct sockaddr_dl *)sdl0; 1035 if (sdl->sdl_alen == ifp->if_addrlen) 1036 mac = LLADDR(sdl); 1037 } 1038 } 1039 if (tlladdr && mac) { 1040 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1041 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1042 1043 /* roundup to 8 bytes alignment! */ 1044 optlen = (optlen + 7) & ~7; 1045 1046 m->m_pkthdr.len += optlen; 1047 m->m_len += optlen; 1048 icmp6len += optlen; 1049 bzero((caddr_t)nd_opt, optlen); 1050 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1051 nd_opt->nd_opt_len = optlen >> 3; 1052 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1053 } else 1054 flags &= ~ND_NA_FLAG_OVERRIDE; 1055 1056 ip6->ip6_plen = htons((u_short)icmp6len); 1057 nd_na->nd_na_flags_reserved = flags; 1058 nd_na->nd_na_cksum = 0; 1059 nd_na->nd_na_cksum = 1060 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1061 1062 if (send_sendso_input_hook != NULL) { 1063 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1064 sizeof(unsigned short), M_NOWAIT); 1065 if (mtag == NULL) 1066 goto bad; 1067 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1068 m_tag_prepend(m, mtag); 1069 } 1070 1071 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1072 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1073 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1074 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1075 1076 return; 1077 1078 bad: 1079 m_freem(m); 1080 } 1081 1082 #ifndef BURN_BRIDGES 1083 void 1084 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1085 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1086 struct sockaddr *sdl0) 1087 { 1088 1089 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1090 RT_DEFAULT_FIB); 1091 } 1092 #endif 1093 1094 caddr_t 1095 nd6_ifptomac(struct ifnet *ifp) 1096 { 1097 switch (ifp->if_type) { 1098 case IFT_ETHER: 1099 case IFT_IEEE1394: 1100 case IFT_L2VLAN: 1101 case IFT_INFINIBAND: 1102 case IFT_BRIDGE: 1103 return IF_LLADDR(ifp); 1104 default: 1105 return NULL; 1106 } 1107 } 1108 1109 struct dadq { 1110 TAILQ_ENTRY(dadq) dad_list; 1111 struct ifaddr *dad_ifa; 1112 int dad_count; /* max NS to send */ 1113 int dad_ns_tcount; /* # of trials to send NS */ 1114 int dad_ns_ocount; /* NS sent so far */ 1115 int dad_ns_icount; 1116 int dad_na_icount; 1117 int dad_ns_lcount; /* looped back NS */ 1118 int dad_loopbackprobe; /* probing state for loopback detection */ 1119 struct callout dad_timer_ch; 1120 struct vnet *dad_vnet; 1121 u_int dad_refcnt; 1122 #define ND_OPT_NONCE_LEN32 \ 1123 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1124 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1125 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */ 1126 }; 1127 1128 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq); 1129 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock); 1130 #define V_dadq VNET(dadq) 1131 #define V_dad_rwlock VNET(dad_rwlock) 1132 1133 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1134 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1135 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1136 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1137 1138 static void 1139 nd6_dad_add(struct dadq *dp) 1140 { 1141 1142 DADQ_WLOCK(); 1143 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1144 dp->dad_ondadq = true; 1145 DADQ_WUNLOCK(); 1146 } 1147 1148 static void 1149 nd6_dad_del(struct dadq *dp) 1150 { 1151 1152 DADQ_WLOCK(); 1153 if (dp->dad_ondadq) { 1154 /* 1155 * Remove dp from the dadq and release the dadq's 1156 * reference. 1157 */ 1158 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1159 dp->dad_ondadq = false; 1160 DADQ_WUNLOCK(); 1161 nd6_dad_rele(dp); 1162 } else 1163 DADQ_WUNLOCK(); 1164 } 1165 1166 static struct dadq * 1167 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1168 { 1169 struct dadq *dp; 1170 1171 DADQ_RLOCK(); 1172 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1173 if (dp->dad_ifa != ifa) 1174 continue; 1175 /* 1176 * Skip if the nonce matches the received one. 1177 * +2 in the length is required because of type and 1178 * length fields are included in a header. 1179 */ 1180 if (n != NULL && 1181 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1182 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1183 ND_OPT_NONCE_LEN) == 0) { 1184 dp->dad_ns_lcount++; 1185 continue; 1186 } 1187 refcount_acquire(&dp->dad_refcnt); 1188 break; 1189 } 1190 DADQ_RUNLOCK(); 1191 1192 return (dp); 1193 } 1194 1195 static void 1196 nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns) 1197 { 1198 1199 NET_EPOCH_ASSERT(); 1200 1201 if (send_ns != 0) 1202 nd6_dad_ns_output(dp); 1203 callout_reset(&dp->dad_timer_ch, ticks, 1204 (void (*)(void *))nd6_dad_timer, (void *)dp); 1205 } 1206 1207 static void 1208 nd6_dad_stoptimer(struct dadq *dp) 1209 { 1210 1211 callout_drain(&dp->dad_timer_ch); 1212 } 1213 1214 static void 1215 nd6_dad_rele(struct dadq *dp) 1216 { 1217 1218 if (refcount_release(&dp->dad_refcnt)) { 1219 ifa_free(dp->dad_ifa); 1220 free(dp, M_IP6NDP); 1221 } 1222 } 1223 1224 void 1225 nd6_dad_init(void) 1226 { 1227 1228 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1229 TAILQ_INIT(&V_dadq); 1230 } 1231 1232 /* 1233 * Start Duplicate Address Detection (DAD) for specified interface address. 1234 */ 1235 void 1236 nd6_dad_start(struct ifaddr *ifa, int delay) 1237 { 1238 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1239 struct dadq *dp; 1240 char ip6buf[INET6_ADDRSTRLEN]; 1241 struct epoch_tracker et; 1242 1243 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0, 1244 ("starting DAD on non-tentative address %p", ifa)); 1245 1246 /* 1247 * If we don't need DAD, don't do it. 1248 * There are several cases: 1249 * - DAD is disabled globally or on the interface 1250 * - the interface address is anycast 1251 */ 1252 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 || 1253 V_ip6_dad_count == 0 || 1254 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) != 0) { 1255 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1256 return; 1257 } 1258 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 || 1259 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || 1260 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) != 0) 1261 return; 1262 1263 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1264 /* 1265 * DAD is already in progress. Let the existing entry 1266 * finish it. 1267 */ 1268 nd6_dad_rele(dp); 1269 return; 1270 } 1271 1272 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1273 if (dp == NULL) { 1274 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1275 "%s(%s)\n", 1276 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1277 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1278 return; 1279 } 1280 callout_init(&dp->dad_timer_ch, 0); 1281 #ifdef VIMAGE 1282 dp->dad_vnet = curvnet; 1283 #endif 1284 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1285 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1286 1287 /* 1288 * Send NS packet for DAD, ip6_dad_count times. 1289 * Note that we must delay the first transmission, if this is the 1290 * first packet to be sent from the interface after interface 1291 * (re)initialization. 1292 */ 1293 dp->dad_ifa = ifa; 1294 ifa_ref(dp->dad_ifa); 1295 dp->dad_count = V_ip6_dad_count; 1296 dp->dad_ns_icount = dp->dad_na_icount = 0; 1297 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1298 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1299 1300 /* Add this to the dadq and add a reference for the dadq. */ 1301 refcount_init(&dp->dad_refcnt, 1); 1302 nd6_dad_add(dp); 1303 NET_EPOCH_ENTER(et); 1304 nd6_dad_starttimer(dp, delay, 0); 1305 NET_EPOCH_EXIT(et); 1306 } 1307 1308 /* 1309 * terminate DAD unconditionally. used for address removals. 1310 */ 1311 void 1312 nd6_dad_stop(struct ifaddr *ifa) 1313 { 1314 struct dadq *dp; 1315 1316 dp = nd6_dad_find(ifa, NULL); 1317 if (!dp) { 1318 /* DAD wasn't started yet */ 1319 return; 1320 } 1321 1322 nd6_dad_stoptimer(dp); 1323 nd6_dad_del(dp); 1324 1325 /* Release this function's reference, acquired by nd6_dad_find(). */ 1326 nd6_dad_rele(dp); 1327 } 1328 1329 static void 1330 nd6_dad_timer(struct dadq *dp) 1331 { 1332 CURVNET_SET(dp->dad_vnet); 1333 struct ifaddr *ifa = dp->dad_ifa; 1334 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1335 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1336 char ip6buf[INET6_ADDRSTRLEN]; 1337 struct epoch_tracker et; 1338 1339 KASSERT(ia != NULL, ("DAD entry %p with no address", dp)); 1340 1341 NET_EPOCH_ENTER(et); 1342 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1343 /* Do not need DAD for ifdisabled interface. */ 1344 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1345 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1346 goto err; 1347 } 1348 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1349 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1350 "%s(%s)\n", 1351 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1352 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1353 goto err; 1354 } 1355 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1356 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1357 "%s(%s)\n", 1358 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1359 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1360 goto err; 1361 } 1362 1363 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1364 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1365 (((ifp->if_flags & IFF_UP) == 0) || 1366 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1367 nd6log((LOG_INFO, "%s: could not run DAD " 1368 "because the interface was down or not running.\n", 1369 if_name(ifa->ifa_ifp))); 1370 goto err; 1371 } 1372 1373 /* Need more checks? */ 1374 if (dp->dad_ns_ocount < dp->dad_count) { 1375 /* 1376 * We have more NS to go. Send NS packet for DAD. 1377 */ 1378 nd6_dad_starttimer(dp, 1379 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1); 1380 goto done; 1381 } else { 1382 /* 1383 * We have transmitted sufficient number of DAD packets. 1384 * See what we've got. 1385 */ 1386 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1387 /* We've seen NS or NA, means DAD has failed. */ 1388 nd6_dad_duplicated(ifa, dp); 1389 else if (V_dad_enhanced != 0 && 1390 dp->dad_ns_lcount > 0 && 1391 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1392 /* 1393 * Sec. 4.1 in RFC 7527 requires transmission of 1394 * additional probes until the loopback condition 1395 * becomes clear when a looped back probe is detected. 1396 */ 1397 log(LOG_ERR, "%s: a looped back NS message is " 1398 "detected during DAD for %s. " 1399 "Another DAD probes are being sent.\n", 1400 if_name(ifa->ifa_ifp), 1401 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1402 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1403 /* 1404 * Send an NS immediately and increase dad_count by 1405 * V_nd6_mmaxtries - 1. 1406 */ 1407 dp->dad_count = 1408 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1409 nd6_dad_starttimer(dp, 1410 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1411 1); 1412 goto done; 1413 } else { 1414 /* 1415 * We are done with DAD. No NA came, no NS came. 1416 * No duplicate address found. Check IFDISABLED flag 1417 * again in case that it is changed between the 1418 * beginning of this function and here. 1419 */ 1420 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1421 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1422 1423 nd6log((LOG_DEBUG, 1424 "%s: DAD complete for %s - no duplicates found\n", 1425 if_name(ifa->ifa_ifp), 1426 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1427 if (dp->dad_ns_lcount > 0) 1428 log(LOG_ERR, "%s: DAD completed while " 1429 "a looped back NS message is detected " 1430 "during DAD for %s.\n", 1431 if_name(ifa->ifa_ifp), 1432 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1433 } 1434 } 1435 err: 1436 nd6_dad_del(dp); 1437 done: 1438 NET_EPOCH_EXIT(et); 1439 CURVNET_RESTORE(); 1440 } 1441 1442 static void 1443 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1444 { 1445 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1446 struct ifnet *ifp; 1447 char ip6buf[INET6_ADDRSTRLEN]; 1448 1449 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1450 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1451 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1452 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1453 dp->dad_na_icount); 1454 1455 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1456 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1457 1458 ifp = ifa->ifa_ifp; 1459 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1460 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1461 log(LOG_ERR, "%s: manual intervention required\n", 1462 if_name(ifp)); 1463 1464 /* 1465 * If the address is a link-local address formed from an interface 1466 * identifier based on the hardware address which is supposed to be 1467 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1468 * operation on the interface SHOULD be disabled. 1469 * [RFC 4862, Section 5.4.5] 1470 */ 1471 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1472 struct in6_addr in6; 1473 1474 /* 1475 * To avoid over-reaction, we only apply this logic when we are 1476 * very sure that hardware addresses are supposed to be unique. 1477 */ 1478 switch (ifp->if_type) { 1479 case IFT_ETHER: 1480 case IFT_ATM: 1481 case IFT_IEEE1394: 1482 case IFT_INFINIBAND: 1483 in6 = ia->ia_addr.sin6_addr; 1484 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1485 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1486 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1487 log(LOG_ERR, "%s: possible hardware address " 1488 "duplication detected, disable IPv6\n", 1489 if_name(ifp)); 1490 } 1491 break; 1492 } 1493 } 1494 } 1495 1496 static void 1497 nd6_dad_ns_output(struct dadq *dp) 1498 { 1499 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1500 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1501 int i; 1502 1503 dp->dad_ns_tcount++; 1504 if ((ifp->if_flags & IFF_UP) == 0) { 1505 return; 1506 } 1507 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1508 return; 1509 } 1510 1511 dp->dad_ns_ocount++; 1512 if (V_dad_enhanced != 0) { 1513 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1514 dp->dad_nonce[i] = arc4random(); 1515 /* 1516 * XXXHRS: Note that in the case that 1517 * DupAddrDetectTransmits > 1, multiple NS messages with 1518 * different nonces can be looped back in an unexpected 1519 * order. The current implementation recognizes only 1520 * the latest nonce on the sender side. Practically it 1521 * should work well in almost all cases. 1522 */ 1523 } 1524 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1525 (uint8_t *)&dp->dad_nonce[0]); 1526 } 1527 1528 static void 1529 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1530 { 1531 struct dadq *dp; 1532 1533 if (ifa == NULL) 1534 panic("ifa == NULL in nd6_dad_ns_input"); 1535 1536 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1537 if (V_dad_enhanced == 0) 1538 ndopt_nonce = NULL; 1539 dp = nd6_dad_find(ifa, ndopt_nonce); 1540 if (dp == NULL) 1541 return; 1542 1543 dp->dad_ns_icount++; 1544 nd6_dad_rele(dp); 1545 } 1546 1547 static void 1548 nd6_dad_na_input(struct ifaddr *ifa) 1549 { 1550 struct dadq *dp; 1551 1552 if (ifa == NULL) 1553 panic("ifa == NULL in nd6_dad_na_input"); 1554 1555 dp = nd6_dad_find(ifa, NULL); 1556 if (dp != NULL) { 1557 dp->dad_na_icount++; 1558 nd6_dad_rele(dp); 1559 } 1560 } 1561