1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $ 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 #include "opt_ipsec.h" 40 #include "opt_mpath.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/malloc.h> 45 #include <sys/libkern.h> 46 #include <sys/lock.h> 47 #include <sys/rwlock.h> 48 #include <sys/mbuf.h> 49 #include <sys/socket.h> 50 #include <sys/sockio.h> 51 #include <sys/time.h> 52 #include <sys/kernel.h> 53 #include <sys/errno.h> 54 #include <sys/sysctl.h> 55 #include <sys/syslog.h> 56 #include <sys/queue.h> 57 #include <sys/callout.h> 58 #include <sys/refcount.h> 59 60 #include <net/if.h> 61 #include <net/if_types.h> 62 #include <net/if_dl.h> 63 #include <net/if_var.h> 64 #include <net/route.h> 65 #ifdef RADIX_MPATH 66 #include <net/radix_mpath.h> 67 #endif 68 #include <net/vnet.h> 69 70 #include <netinet/in.h> 71 #include <netinet/in_var.h> 72 #include <net/if_llatbl.h> 73 #include <netinet6/in6_var.h> 74 #include <netinet6/in6_ifattach.h> 75 #include <netinet/ip6.h> 76 #include <netinet6/ip6_var.h> 77 #include <netinet6/scope6_var.h> 78 #include <netinet6/nd6.h> 79 #include <netinet/icmp6.h> 80 #include <netinet/ip_carp.h> 81 #include <netinet6/send.h> 82 83 #define SDL(s) ((struct sockaddr_dl *)s) 84 85 struct dadq; 86 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *); 87 static void nd6_dad_add(struct dadq *dp); 88 static void nd6_dad_del(struct dadq *dp); 89 static void nd6_dad_rele(struct dadq *); 90 static void nd6_dad_starttimer(struct dadq *, int, int); 91 static void nd6_dad_stoptimer(struct dadq *); 92 static void nd6_dad_timer(struct dadq *); 93 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *); 94 static void nd6_dad_ns_output(struct dadq *); 95 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *); 96 static void nd6_dad_na_input(struct ifaddr *); 97 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 98 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 99 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *, 100 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int); 101 102 static VNET_DEFINE(int, dad_enhanced) = 1; 103 #define V_dad_enhanced VNET(dad_enhanced) 104 105 SYSCTL_DECL(_net_inet6_ip6); 106 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW, 107 &VNET_NAME(dad_enhanced), 0, 108 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD."); 109 110 static VNET_DEFINE(int, dad_maxtry) = 15; /* max # of *tries* to 111 transmit DAD packet */ 112 #define V_dad_maxtry VNET(dad_maxtry) 113 114 /* 115 * Input a Neighbor Solicitation Message. 116 * 117 * Based on RFC 2461 118 * Based on RFC 2462 (duplicate address detection) 119 */ 120 void 121 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 122 { 123 struct ifnet *ifp = m->m_pkthdr.rcvif; 124 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 125 struct nd_neighbor_solicit *nd_ns; 126 struct in6_addr saddr6 = ip6->ip6_src; 127 struct in6_addr daddr6 = ip6->ip6_dst; 128 struct in6_addr taddr6; 129 struct in6_addr myaddr6; 130 char *lladdr = NULL; 131 struct ifaddr *ifa = NULL; 132 int lladdrlen = 0; 133 int anycast = 0, proxy = 0, tentative = 0; 134 int tlladdr; 135 int rflag; 136 union nd_opts ndopts; 137 struct sockaddr_dl proxydl; 138 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 139 140 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 141 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 142 rflag = 0; 143 #ifndef PULLDOWN_TEST 144 IP6_EXTHDR_CHECK(m, off, icmp6len,); 145 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 146 #else 147 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); 148 if (nd_ns == NULL) { 149 ICMP6STAT_INC(icp6s_tooshort); 150 return; 151 } 152 #endif 153 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ 154 taddr6 = nd_ns->nd_ns_target; 155 if (in6_setscope(&taddr6, ifp, NULL) != 0) 156 goto bad; 157 158 if (ip6->ip6_hlim != 255) { 159 nd6log((LOG_ERR, 160 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 161 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 162 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 163 goto bad; 164 } 165 166 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 167 /* dst has to be a solicited node multicast address. */ 168 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 169 /* don't check ifindex portion */ 170 daddr6.s6_addr32[1] == 0 && 171 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 172 daddr6.s6_addr8[12] == 0xff) { 173 ; /* good */ 174 } else { 175 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 176 "(wrong ip6 dst)\n")); 177 goto bad; 178 } 179 } else if (!V_nd6_onlink_ns_rfc4861) { 180 struct sockaddr_in6 src_sa6; 181 182 /* 183 * According to recent IETF discussions, it is not a good idea 184 * to accept a NS from an address which would not be deemed 185 * to be a neighbor otherwise. This point is expected to be 186 * clarified in future revisions of the specification. 187 */ 188 bzero(&src_sa6, sizeof(src_sa6)); 189 src_sa6.sin6_family = AF_INET6; 190 src_sa6.sin6_len = sizeof(src_sa6); 191 src_sa6.sin6_addr = saddr6; 192 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 193 nd6log((LOG_INFO, "nd6_ns_input: " 194 "NS packet from non-neighbor\n")); 195 goto bad; 196 } 197 } 198 199 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 200 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 201 goto bad; 202 } 203 204 icmp6len -= sizeof(*nd_ns); 205 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 206 if (nd6_options(&ndopts) < 0) { 207 nd6log((LOG_INFO, 208 "nd6_ns_input: invalid ND option, ignored\n")); 209 /* nd6_options have incremented stats */ 210 goto freeit; 211 } 212 213 if (ndopts.nd_opts_src_lladdr) { 214 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 215 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 216 } 217 218 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 219 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 220 "(link-layer address option)\n")); 221 goto bad; 222 } 223 224 /* 225 * Attaching target link-layer address to the NA? 226 * (RFC 2461 7.2.4) 227 * 228 * NS IP dst is unicast/anycast MUST NOT add 229 * NS IP dst is solicited-node multicast MUST add 230 * 231 * In implementation, we add target link-layer address by default. 232 * We do not add one in MUST NOT cases. 233 */ 234 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 235 tlladdr = 0; 236 else 237 tlladdr = 1; 238 239 /* 240 * Target address (taddr6) must be either: 241 * (1) Valid unicast/anycast address for my receiving interface, 242 * (2) Unicast address for which I'm offering proxy service, or 243 * (3) "tentative" address on which DAD is being performed. 244 */ 245 /* (1) and (3) check. */ 246 if (ifp->if_carp) 247 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 248 else 249 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 250 251 /* (2) check. */ 252 if (ifa == NULL) { 253 struct sockaddr_dl rt_gateway; 254 struct rt_addrinfo info; 255 struct sockaddr_in6 dst6; 256 257 bzero(&dst6, sizeof(dst6)); 258 dst6.sin6_len = sizeof(struct sockaddr_in6); 259 dst6.sin6_family = AF_INET6; 260 dst6.sin6_addr = taddr6; 261 262 bzero(&rt_gateway, sizeof(rt_gateway)); 263 rt_gateway.sdl_len = sizeof(rt_gateway); 264 bzero(&info, sizeof(info)); 265 info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway; 266 267 if (rib_lookup_info(ifp->if_fib, (struct sockaddr *)&dst6, 268 0, 0, &info) == 0) { 269 if ((info.rti_flags & RTF_ANNOUNCE) != 0 && 270 rt_gateway.sdl_family == AF_LINK) { 271 272 /* 273 * proxy NDP for single entry 274 */ 275 proxydl = *SDL(&rt_gateway); 276 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal( 277 ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 278 if (ifa) 279 proxy = 1; 280 } 281 } 282 } 283 if (ifa == NULL) { 284 /* 285 * We've got an NS packet, and we don't have that adddress 286 * assigned for us. We MUST silently ignore it. 287 * See RFC2461 7.2.3. 288 */ 289 goto freeit; 290 } 291 myaddr6 = *IFA_IN6(ifa); 292 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 293 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 294 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 295 goto freeit; 296 297 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 298 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 299 "(if %d, NS packet %d)\n", 300 ip6_sprintf(ip6bufs, &taddr6), 301 ifp->if_addrlen, lladdrlen - 2)); 302 goto bad; 303 } 304 305 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 306 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 307 ip6_sprintf(ip6bufs, &saddr6))); 308 goto freeit; 309 } 310 311 /* 312 * We have neighbor solicitation packet, with target address equals to 313 * one of my tentative address. 314 * 315 * src addr how to process? 316 * --- --- 317 * multicast of course, invalid (rejected in ip6_input) 318 * unicast somebody is doing address resolution -> ignore 319 * unspec dup address detection 320 * 321 * The processing is defined in RFC 2462. 322 */ 323 if (tentative) { 324 /* 325 * If source address is unspecified address, it is for 326 * duplicate address detection. 327 * 328 * If not, the packet is for addess resolution; 329 * silently ignore it. 330 */ 331 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 332 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 333 334 goto freeit; 335 } 336 337 /* 338 * If the source address is unspecified address, entries must not 339 * be created or updated. 340 * It looks that sender is performing DAD. Output NA toward 341 * all-node multicast address, to tell the sender that I'm using 342 * the address. 343 * S bit ("solicited") must be zero. 344 */ 345 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 346 struct in6_addr in6_all; 347 348 in6_all = in6addr_linklocal_allnodes; 349 if (in6_setscope(&in6_all, ifp, NULL) != 0) 350 goto bad; 351 nd6_na_output_fib(ifp, &in6_all, &taddr6, 352 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 353 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 354 M_GETFIB(m)); 355 goto freeit; 356 } 357 358 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 359 ND_NEIGHBOR_SOLICIT, 0); 360 361 nd6_na_output_fib(ifp, &saddr6, &taddr6, 362 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 363 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 364 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 365 freeit: 366 if (ifa != NULL) 367 ifa_free(ifa); 368 m_freem(m); 369 return; 370 371 bad: 372 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 373 ip6_sprintf(ip6bufs, &saddr6))); 374 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 375 ip6_sprintf(ip6bufs, &daddr6))); 376 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 377 ip6_sprintf(ip6bufs, &taddr6))); 378 ICMP6STAT_INC(icp6s_badns); 379 if (ifa != NULL) 380 ifa_free(ifa); 381 m_freem(m); 382 } 383 384 /* 385 * Output a Neighbor Solicitation Message. Caller specifies: 386 * - ICMP6 header source IP6 address 387 * - ND6 header target IP6 address 388 * - ND6 header source datalink address 389 * 390 * Based on RFC 2461 391 * Based on RFC 2462 (duplicate address detection) 392 * 393 * ln - for source address determination 394 * nonce - If non-NULL, NS is used for duplicate address detection and 395 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 396 */ 397 static void 398 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 399 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 400 uint8_t *nonce, u_int fibnum) 401 { 402 struct mbuf *m; 403 struct m_tag *mtag; 404 struct ip6_hdr *ip6; 405 struct nd_neighbor_solicit *nd_ns; 406 struct ip6_moptions im6o; 407 int icmp6len; 408 int maxlen; 409 caddr_t mac; 410 411 if (IN6_IS_ADDR_MULTICAST(taddr6)) 412 return; 413 414 /* estimate the size of message */ 415 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 416 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 417 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 418 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 419 __func__, max_linkhdr, maxlen, MCLBYTES)); 420 421 if (max_linkhdr + maxlen > MHLEN) 422 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 423 else 424 m = m_gethdr(M_NOWAIT, MT_DATA); 425 if (m == NULL) 426 return; 427 M_SETFIB(m, fibnum); 428 429 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 430 m->m_flags |= M_MCAST; 431 im6o.im6o_multicast_ifp = ifp; 432 im6o.im6o_multicast_hlim = 255; 433 im6o.im6o_multicast_loop = 0; 434 } 435 436 icmp6len = sizeof(*nd_ns); 437 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 438 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 439 440 /* fill neighbor solicitation packet */ 441 ip6 = mtod(m, struct ip6_hdr *); 442 ip6->ip6_flow = 0; 443 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 444 ip6->ip6_vfc |= IPV6_VERSION; 445 /* ip6->ip6_plen will be set later */ 446 ip6->ip6_nxt = IPPROTO_ICMPV6; 447 ip6->ip6_hlim = 255; 448 if (daddr6) 449 ip6->ip6_dst = *daddr6; 450 else { 451 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 452 ip6->ip6_dst.s6_addr16[1] = 0; 453 ip6->ip6_dst.s6_addr32[1] = 0; 454 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 455 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 456 ip6->ip6_dst.s6_addr8[12] = 0xff; 457 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 458 goto bad; 459 } 460 if (nonce == NULL) { 461 struct ifaddr *ifa = NULL; 462 463 /* 464 * RFC2461 7.2.2: 465 * "If the source address of the packet prompting the 466 * solicitation is the same as one of the addresses assigned 467 * to the outgoing interface, that address SHOULD be placed 468 * in the IP Source Address of the outgoing solicitation. 469 * Otherwise, any one of the addresses assigned to the 470 * interface should be used." 471 * 472 * We use the source address for the prompting packet 473 * (saddr6), if saddr6 belongs to the outgoing interface. 474 * Otherwise, we perform the source address selection as usual. 475 */ 476 477 if (saddr6 != NULL) 478 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 479 if (ifa != NULL) { 480 /* ip6_src set already. */ 481 ip6->ip6_src = *saddr6; 482 ifa_free(ifa); 483 } else { 484 int error; 485 struct in6_addr dst6, src6; 486 uint32_t scopeid; 487 488 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); 489 error = in6_selectsrc_addr(fibnum, &dst6, 490 scopeid, ifp, &src6, NULL); 491 if (error) { 492 char ip6buf[INET6_ADDRSTRLEN]; 493 nd6log((LOG_DEBUG, "%s: source can't be " 494 "determined: dst=%s, error=%d\n", __func__, 495 ip6_sprintf(ip6buf, &dst6), 496 error)); 497 goto bad; 498 } 499 ip6->ip6_src = src6; 500 } 501 } else { 502 /* 503 * Source address for DAD packet must always be IPv6 504 * unspecified address. (0::0) 505 * We actually don't have to 0-clear the address (we did it 506 * above), but we do so here explicitly to make the intention 507 * clearer. 508 */ 509 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 510 } 511 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 512 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 513 nd_ns->nd_ns_code = 0; 514 nd_ns->nd_ns_reserved = 0; 515 nd_ns->nd_ns_target = *taddr6; 516 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 517 518 /* 519 * Add source link-layer address option. 520 * 521 * spec implementation 522 * --- --- 523 * DAD packet MUST NOT do not add the option 524 * there's no link layer address: 525 * impossible do not add the option 526 * there's link layer address: 527 * Multicast NS MUST add one add the option 528 * Unicast NS SHOULD add one add the option 529 */ 530 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 531 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 532 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 533 /* 8 byte alignments... */ 534 optlen = (optlen + 7) & ~7; 535 536 m->m_pkthdr.len += optlen; 537 m->m_len += optlen; 538 icmp6len += optlen; 539 bzero((caddr_t)nd_opt, optlen); 540 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 541 nd_opt->nd_opt_len = optlen >> 3; 542 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 543 } 544 /* 545 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 546 * This behavior is documented as Enhanced Duplicate Address 547 * Detection in RFC 7527. 548 * net.inet6.ip6.dad_enhanced=0 disables this. 549 */ 550 if (V_dad_enhanced != 0 && nonce != NULL) { 551 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 552 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 553 /* 8-byte alignment is required. */ 554 optlen = (optlen + 7) & ~7; 555 556 m->m_pkthdr.len += optlen; 557 m->m_len += optlen; 558 icmp6len += optlen; 559 bzero((caddr_t)nd_opt, optlen); 560 nd_opt->nd_opt_type = ND_OPT_NONCE; 561 nd_opt->nd_opt_len = optlen >> 3; 562 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 563 } 564 ip6->ip6_plen = htons((u_short)icmp6len); 565 nd_ns->nd_ns_cksum = 0; 566 nd_ns->nd_ns_cksum = 567 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 568 569 if (send_sendso_input_hook != NULL) { 570 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 571 sizeof(unsigned short), M_NOWAIT); 572 if (mtag == NULL) 573 goto bad; 574 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 575 m_tag_prepend(m, mtag); 576 } 577 578 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 579 &im6o, NULL, NULL); 580 icmp6_ifstat_inc(ifp, ifs6_out_msg); 581 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 582 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 583 584 return; 585 586 bad: 587 m_freem(m); 588 } 589 590 #ifndef BURN_BRIDGES 591 void 592 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 593 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 594 { 595 596 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 597 } 598 #endif 599 /* 600 * Neighbor advertisement input handling. 601 * 602 * Based on RFC 2461 603 * Based on RFC 2462 (duplicate address detection) 604 * 605 * the following items are not implemented yet: 606 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 607 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 608 */ 609 void 610 nd6_na_input(struct mbuf *m, int off, int icmp6len) 611 { 612 struct ifnet *ifp = m->m_pkthdr.rcvif; 613 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 614 struct nd_neighbor_advert *nd_na; 615 struct in6_addr daddr6 = ip6->ip6_dst; 616 struct in6_addr taddr6; 617 int flags; 618 int is_router; 619 int is_solicited; 620 int is_override; 621 char *lladdr = NULL; 622 int lladdrlen = 0; 623 int checklink = 0; 624 struct ifaddr *ifa; 625 struct llentry *ln = NULL; 626 union nd_opts ndopts; 627 struct mbuf *chain = NULL; 628 struct sockaddr_in6 sin6; 629 u_char linkhdr[LLE_MAX_LINKHDR]; 630 size_t linkhdrsize; 631 int lladdr_off; 632 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 633 634 if (ip6->ip6_hlim != 255) { 635 nd6log((LOG_ERR, 636 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 637 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 638 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 639 goto bad; 640 } 641 642 #ifndef PULLDOWN_TEST 643 IP6_EXTHDR_CHECK(m, off, icmp6len,); 644 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 645 #else 646 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 647 if (nd_na == NULL) { 648 ICMP6STAT_INC(icp6s_tooshort); 649 return; 650 } 651 #endif 652 653 flags = nd_na->nd_na_flags_reserved; 654 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 655 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 656 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 657 memset(&sin6, 0, sizeof(sin6)); 658 659 taddr6 = nd_na->nd_na_target; 660 if (in6_setscope(&taddr6, ifp, NULL)) 661 goto bad; /* XXX: impossible */ 662 663 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 664 nd6log((LOG_ERR, 665 "nd6_na_input: invalid target address %s\n", 666 ip6_sprintf(ip6bufs, &taddr6))); 667 goto bad; 668 } 669 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 670 if (is_solicited) { 671 nd6log((LOG_ERR, 672 "nd6_na_input: a solicited adv is multicasted\n")); 673 goto bad; 674 } 675 676 icmp6len -= sizeof(*nd_na); 677 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 678 if (nd6_options(&ndopts) < 0) { 679 nd6log((LOG_INFO, 680 "nd6_na_input: invalid ND option, ignored\n")); 681 /* nd6_options have incremented stats */ 682 goto freeit; 683 } 684 685 if (ndopts.nd_opts_tgt_lladdr) { 686 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 687 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 688 } 689 690 /* 691 * This effectively disables the DAD check on a non-master CARP 692 * address. 693 */ 694 if (ifp->if_carp) 695 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 696 else 697 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 698 699 /* 700 * Target address matches one of my interface address. 701 * 702 * If my address is tentative, this means that there's somebody 703 * already using the same address as mine. This indicates DAD failure. 704 * This is defined in RFC 2462. 705 * 706 * Otherwise, process as defined in RFC 2461. 707 */ 708 if (ifa 709 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 710 nd6_dad_na_input(ifa); 711 ifa_free(ifa); 712 goto freeit; 713 } 714 715 /* Just for safety, maybe unnecessary. */ 716 if (ifa) { 717 ifa_free(ifa); 718 log(LOG_ERR, 719 "nd6_na_input: duplicate IP6 address %s\n", 720 ip6_sprintf(ip6bufs, &taddr6)); 721 goto freeit; 722 } 723 724 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 725 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 726 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 727 ifp->if_addrlen, lladdrlen - 2)); 728 goto bad; 729 } 730 731 /* 732 * If no neighbor cache entry is found, NA SHOULD silently be 733 * discarded. 734 */ 735 IF_AFDATA_RLOCK(ifp); 736 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 737 IF_AFDATA_RUNLOCK(ifp); 738 if (ln == NULL) { 739 goto freeit; 740 } 741 742 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 743 /* 744 * If the link-layer has address, and no lladdr option came, 745 * discard the packet. 746 */ 747 if (ifp->if_addrlen && lladdr == NULL) { 748 goto freeit; 749 } 750 751 /* 752 * Record link-layer address, and update the state. 753 */ 754 linkhdrsize = sizeof(linkhdr); 755 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 756 linkhdr, &linkhdrsize, &lladdr_off) != 0) 757 return; 758 759 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize, 760 lladdr_off) == 0) { 761 ln = NULL; 762 goto freeit; 763 } 764 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 765 if (is_solicited) 766 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 767 else 768 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 769 if ((ln->ln_router = is_router) != 0) { 770 /* 771 * This means a router's state has changed from 772 * non-reachable to probably reachable, and might 773 * affect the status of associated prefixes.. 774 */ 775 checklink = 1; 776 } 777 } else { 778 int llchange; 779 780 /* 781 * Check if the link-layer address has changed or not. 782 */ 783 if (lladdr == NULL) 784 llchange = 0; 785 else { 786 if (ln->la_flags & LLE_VALID) { 787 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 788 llchange = 1; 789 else 790 llchange = 0; 791 } else 792 llchange = 1; 793 } 794 795 /* 796 * This is VERY complex. Look at it with care. 797 * 798 * override solicit lladdr llchange action 799 * (L: record lladdr) 800 * 801 * 0 0 n -- (2c) 802 * 0 0 y n (2b) L 803 * 0 0 y y (1) REACHABLE->STALE 804 * 0 1 n -- (2c) *->REACHABLE 805 * 0 1 y n (2b) L *->REACHABLE 806 * 0 1 y y (1) REACHABLE->STALE 807 * 1 0 n -- (2a) 808 * 1 0 y n (2a) L 809 * 1 0 y y (2a) L *->STALE 810 * 1 1 n -- (2a) *->REACHABLE 811 * 1 1 y n (2a) L *->REACHABLE 812 * 1 1 y y (2a) L *->REACHABLE 813 */ 814 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 815 /* 816 * If state is REACHABLE, make it STALE. 817 * no other updates should be done. 818 */ 819 if (ln->ln_state == ND6_LLINFO_REACHABLE) 820 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 821 goto freeit; 822 } else if (is_override /* (2a) */ 823 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 824 || lladdr == NULL) { /* (2c) */ 825 /* 826 * Update link-local address, if any. 827 */ 828 if (lladdr != NULL) { 829 linkhdrsize = sizeof(linkhdr); 830 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 831 linkhdr, &linkhdrsize, &lladdr_off) != 0) 832 goto freeit; 833 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 834 linkhdrsize, lladdr_off) == 0) { 835 ln = NULL; 836 goto freeit; 837 } 838 EVENTHANDLER_INVOKE(lle_event, ln, 839 LLENTRY_RESOLVED); 840 } 841 842 /* 843 * If solicited, make the state REACHABLE. 844 * If not solicited and the link-layer address was 845 * changed, make it STALE. 846 */ 847 if (is_solicited) 848 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 849 else { 850 if (lladdr != NULL && llchange) 851 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 852 } 853 } 854 855 if (ln->ln_router && !is_router) { 856 /* 857 * The peer dropped the router flag. 858 * Remove the sender from the Default Router List and 859 * update the Destination Cache entries. 860 */ 861 struct ifnet *nd6_ifp; 862 863 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 864 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 865 (ND_IFINFO(nd6_ifp)->flags & 866 ND6_IFF_ACCEPT_RTADV) != 0) 867 /* 868 * Even if the neighbor is not in the default 869 * router list, the neighbor may be used as a 870 * next hop for some destinations (e.g. redirect 871 * case). So we must call rt6_flush explicitly. 872 */ 873 rt6_flush(&ip6->ip6_src, ifp); 874 } 875 ln->ln_router = is_router; 876 } 877 /* XXX - QL 878 * Does this matter? 879 * rt->rt_flags &= ~RTF_REJECT; 880 */ 881 ln->la_asked = 0; 882 if (ln->la_hold != NULL) 883 nd6_grab_holdchain(ln, &chain, &sin6); 884 freeit: 885 if (ln != NULL) 886 LLE_WUNLOCK(ln); 887 888 if (chain != NULL) 889 nd6_flush_holdchain(ifp, ifp, chain, &sin6); 890 891 if (checklink) 892 pfxlist_onlink_check(); 893 894 m_freem(m); 895 return; 896 897 bad: 898 if (ln != NULL) 899 LLE_WUNLOCK(ln); 900 901 ICMP6STAT_INC(icp6s_badna); 902 m_freem(m); 903 } 904 905 /* 906 * Neighbor advertisement output handling. 907 * 908 * Based on RFC 2461 909 * 910 * the following items are not implemented yet: 911 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 912 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 913 * 914 * tlladdr - 1 if include target link-layer address 915 * sdl0 - sockaddr_dl (= proxy NA) or NULL 916 */ 917 static void 918 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 919 const struct in6_addr *taddr6, u_long flags, int tlladdr, 920 struct sockaddr *sdl0, u_int fibnum) 921 { 922 struct mbuf *m; 923 struct m_tag *mtag; 924 struct ip6_hdr *ip6; 925 struct nd_neighbor_advert *nd_na; 926 struct ip6_moptions im6o; 927 struct in6_addr daddr6, dst6, src6; 928 uint32_t scopeid; 929 930 int icmp6len, maxlen, error; 931 caddr_t mac = NULL; 932 933 daddr6 = *daddr6_0; /* make a local copy for modification */ 934 935 /* estimate the size of message */ 936 maxlen = sizeof(*ip6) + sizeof(*nd_na); 937 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 938 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 939 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 940 __func__, max_linkhdr, maxlen, MCLBYTES)); 941 942 if (max_linkhdr + maxlen > MHLEN) 943 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 944 else 945 m = m_gethdr(M_NOWAIT, MT_DATA); 946 if (m == NULL) 947 return; 948 M_SETFIB(m, fibnum); 949 950 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 951 m->m_flags |= M_MCAST; 952 im6o.im6o_multicast_ifp = ifp; 953 im6o.im6o_multicast_hlim = 255; 954 im6o.im6o_multicast_loop = 0; 955 } 956 957 icmp6len = sizeof(*nd_na); 958 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 959 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 960 961 /* fill neighbor advertisement packet */ 962 ip6 = mtod(m, struct ip6_hdr *); 963 ip6->ip6_flow = 0; 964 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 965 ip6->ip6_vfc |= IPV6_VERSION; 966 ip6->ip6_nxt = IPPROTO_ICMPV6; 967 ip6->ip6_hlim = 255; 968 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 969 /* reply to DAD */ 970 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 971 daddr6.s6_addr16[1] = 0; 972 daddr6.s6_addr32[1] = 0; 973 daddr6.s6_addr32[2] = 0; 974 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 975 if (in6_setscope(&daddr6, ifp, NULL)) 976 goto bad; 977 978 flags &= ~ND_NA_FLAG_SOLICITED; 979 } 980 ip6->ip6_dst = daddr6; 981 982 /* 983 * Select a source whose scope is the same as that of the dest. 984 */ 985 in6_splitscope(&daddr6, &dst6, &scopeid); 986 error = in6_selectsrc_addr(fibnum, &dst6, 987 scopeid, ifp, &src6, NULL); 988 if (error) { 989 char ip6buf[INET6_ADDRSTRLEN]; 990 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 991 "determined: dst=%s, error=%d\n", 992 ip6_sprintf(ip6buf, &daddr6), error)); 993 goto bad; 994 } 995 ip6->ip6_src = src6; 996 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 997 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 998 nd_na->nd_na_code = 0; 999 nd_na->nd_na_target = *taddr6; 1000 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1001 1002 /* 1003 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1004 * see nd6_ns_input() for details. 1005 * Basically, if NS packet is sent to unicast/anycast addr, 1006 * target lladdr option SHOULD NOT be included. 1007 */ 1008 if (tlladdr) { 1009 /* 1010 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1011 * lladdr in sdl0. If we are not proxying (sending NA for 1012 * my address) use lladdr configured for the interface. 1013 */ 1014 if (sdl0 == NULL) { 1015 if (ifp->if_carp) 1016 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1017 if (mac == NULL) 1018 mac = nd6_ifptomac(ifp); 1019 } else if (sdl0->sa_family == AF_LINK) { 1020 struct sockaddr_dl *sdl; 1021 sdl = (struct sockaddr_dl *)sdl0; 1022 if (sdl->sdl_alen == ifp->if_addrlen) 1023 mac = LLADDR(sdl); 1024 } 1025 } 1026 if (tlladdr && mac) { 1027 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1028 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1029 1030 /* roundup to 8 bytes alignment! */ 1031 optlen = (optlen + 7) & ~7; 1032 1033 m->m_pkthdr.len += optlen; 1034 m->m_len += optlen; 1035 icmp6len += optlen; 1036 bzero((caddr_t)nd_opt, optlen); 1037 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1038 nd_opt->nd_opt_len = optlen >> 3; 1039 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1040 } else 1041 flags &= ~ND_NA_FLAG_OVERRIDE; 1042 1043 ip6->ip6_plen = htons((u_short)icmp6len); 1044 nd_na->nd_na_flags_reserved = flags; 1045 nd_na->nd_na_cksum = 0; 1046 nd_na->nd_na_cksum = 1047 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1048 1049 if (send_sendso_input_hook != NULL) { 1050 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1051 sizeof(unsigned short), M_NOWAIT); 1052 if (mtag == NULL) 1053 goto bad; 1054 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1055 m_tag_prepend(m, mtag); 1056 } 1057 1058 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1059 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1060 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1061 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1062 1063 return; 1064 1065 bad: 1066 m_freem(m); 1067 } 1068 1069 #ifndef BURN_BRIDGES 1070 void 1071 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1072 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1073 struct sockaddr *sdl0) 1074 { 1075 1076 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1077 RT_DEFAULT_FIB); 1078 } 1079 #endif 1080 1081 caddr_t 1082 nd6_ifptomac(struct ifnet *ifp) 1083 { 1084 switch (ifp->if_type) { 1085 case IFT_ARCNET: 1086 case IFT_ETHER: 1087 case IFT_FDDI: 1088 case IFT_IEEE1394: 1089 case IFT_L2VLAN: 1090 case IFT_INFINIBAND: 1091 case IFT_BRIDGE: 1092 case IFT_ISO88025: 1093 return IF_LLADDR(ifp); 1094 default: 1095 return NULL; 1096 } 1097 } 1098 1099 struct dadq { 1100 TAILQ_ENTRY(dadq) dad_list; 1101 struct ifaddr *dad_ifa; 1102 int dad_count; /* max NS to send */ 1103 int dad_ns_tcount; /* # of trials to send NS */ 1104 int dad_ns_ocount; /* NS sent so far */ 1105 int dad_ns_icount; 1106 int dad_na_icount; 1107 int dad_ns_lcount; /* looped back NS */ 1108 int dad_loopbackprobe; /* probing state for loopback detection */ 1109 struct callout dad_timer_ch; 1110 struct vnet *dad_vnet; 1111 u_int dad_refcnt; 1112 #define ND_OPT_NONCE_LEN32 \ 1113 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1114 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1115 }; 1116 1117 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq); 1118 static VNET_DEFINE(struct rwlock, dad_rwlock); 1119 #define V_dadq VNET(dadq) 1120 #define V_dad_rwlock VNET(dad_rwlock) 1121 1122 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1123 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1124 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1125 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1126 1127 static void 1128 nd6_dad_add(struct dadq *dp) 1129 { 1130 1131 DADQ_WLOCK(); 1132 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1133 DADQ_WUNLOCK(); 1134 } 1135 1136 static void 1137 nd6_dad_del(struct dadq *dp) 1138 { 1139 1140 DADQ_WLOCK(); 1141 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1142 DADQ_WUNLOCK(); 1143 nd6_dad_rele(dp); 1144 } 1145 1146 static struct dadq * 1147 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1148 { 1149 struct dadq *dp; 1150 1151 DADQ_RLOCK(); 1152 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1153 if (dp->dad_ifa != ifa) 1154 continue; 1155 /* 1156 * Skip if the nonce matches the received one. 1157 * +2 in the length is required because of type and 1158 * length fields are included in a header. 1159 */ 1160 if (n != NULL && 1161 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1162 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1163 ND_OPT_NONCE_LEN) == 0) { 1164 dp->dad_ns_lcount++; 1165 continue; 1166 } 1167 refcount_acquire(&dp->dad_refcnt); 1168 break; 1169 } 1170 DADQ_RUNLOCK(); 1171 1172 return (dp); 1173 } 1174 1175 static void 1176 nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns) 1177 { 1178 1179 if (send_ns != 0) 1180 nd6_dad_ns_output(dp); 1181 callout_reset(&dp->dad_timer_ch, ticks, 1182 (void (*)(void *))nd6_dad_timer, (void *)dp); 1183 } 1184 1185 static void 1186 nd6_dad_stoptimer(struct dadq *dp) 1187 { 1188 1189 callout_drain(&dp->dad_timer_ch); 1190 } 1191 1192 static void 1193 nd6_dad_rele(struct dadq *dp) 1194 { 1195 1196 if (refcount_release(&dp->dad_refcnt)) { 1197 ifa_free(dp->dad_ifa); 1198 free(dp, M_IP6NDP); 1199 } 1200 } 1201 1202 void 1203 nd6_dad_init(void) 1204 { 1205 1206 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1207 TAILQ_INIT(&V_dadq); 1208 } 1209 1210 /* 1211 * Start Duplicate Address Detection (DAD) for specified interface address. 1212 */ 1213 void 1214 nd6_dad_start(struct ifaddr *ifa, int delay) 1215 { 1216 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1217 struct dadq *dp; 1218 char ip6buf[INET6_ADDRSTRLEN]; 1219 1220 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0, 1221 ("starting DAD on non-tentative address %p", ifa)); 1222 1223 /* 1224 * If we don't need DAD, don't do it. 1225 * There are several cases: 1226 * - DAD is disabled globally or on the interface 1227 * - the interface address is anycast 1228 */ 1229 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 || 1230 V_ip6_dad_count == 0 || 1231 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) != 0) { 1232 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1233 return; 1234 } 1235 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 || 1236 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || 1237 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) != 0) 1238 return; 1239 1240 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1241 /* 1242 * DAD is already in progress. Let the existing entry 1243 * finish it. 1244 */ 1245 nd6_dad_rele(dp); 1246 return; 1247 } 1248 1249 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1250 if (dp == NULL) { 1251 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1252 "%s(%s)\n", 1253 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1254 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1255 return; 1256 } 1257 callout_init(&dp->dad_timer_ch, 0); 1258 #ifdef VIMAGE 1259 dp->dad_vnet = curvnet; 1260 #endif 1261 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1262 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1263 1264 /* 1265 * Send NS packet for DAD, ip6_dad_count times. 1266 * Note that we must delay the first transmission, if this is the 1267 * first packet to be sent from the interface after interface 1268 * (re)initialization. 1269 */ 1270 dp->dad_ifa = ifa; 1271 ifa_ref(dp->dad_ifa); 1272 dp->dad_count = V_ip6_dad_count; 1273 dp->dad_ns_icount = dp->dad_na_icount = 0; 1274 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1275 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1276 refcount_init(&dp->dad_refcnt, 1); 1277 nd6_dad_add(dp); 1278 nd6_dad_starttimer(dp, delay, 0); 1279 } 1280 1281 /* 1282 * terminate DAD unconditionally. used for address removals. 1283 */ 1284 void 1285 nd6_dad_stop(struct ifaddr *ifa) 1286 { 1287 struct dadq *dp; 1288 1289 dp = nd6_dad_find(ifa, NULL); 1290 if (!dp) { 1291 /* DAD wasn't started yet */ 1292 return; 1293 } 1294 1295 nd6_dad_stoptimer(dp); 1296 1297 /* 1298 * The DAD queue entry may have been removed by nd6_dad_timer() while 1299 * we were waiting for it to stop, so re-do the lookup. 1300 */ 1301 nd6_dad_rele(dp); 1302 if (nd6_dad_find(ifa, NULL) == NULL) 1303 return; 1304 1305 nd6_dad_del(dp); 1306 nd6_dad_rele(dp); 1307 } 1308 1309 static void 1310 nd6_dad_timer(struct dadq *dp) 1311 { 1312 CURVNET_SET(dp->dad_vnet); 1313 struct ifaddr *ifa = dp->dad_ifa; 1314 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1315 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1316 char ip6buf[INET6_ADDRSTRLEN]; 1317 1318 KASSERT(ia != NULL, ("DAD entry %p with no address", dp)); 1319 1320 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1321 /* Do not need DAD for ifdisabled interface. */ 1322 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1323 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1324 goto err; 1325 } 1326 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1327 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1328 "%s(%s)\n", 1329 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1330 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1331 goto err; 1332 } 1333 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1334 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1335 "%s(%s)\n", 1336 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1337 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1338 goto err; 1339 } 1340 1341 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1342 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1343 (((ifp->if_flags & IFF_UP) == 0) || 1344 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1345 nd6log((LOG_INFO, "%s: could not run DAD " 1346 "because the interface was down or not running.\n", 1347 if_name(ifa->ifa_ifp))); 1348 goto err; 1349 } 1350 1351 /* Need more checks? */ 1352 if (dp->dad_ns_ocount < dp->dad_count) { 1353 /* 1354 * We have more NS to go. Send NS packet for DAD. 1355 */ 1356 nd6_dad_starttimer(dp, 1357 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1); 1358 goto done; 1359 } else { 1360 /* 1361 * We have transmitted sufficient number of DAD packets. 1362 * See what we've got. 1363 */ 1364 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1365 /* We've seen NS or NA, means DAD has failed. */ 1366 nd6_dad_duplicated(ifa, dp); 1367 else if (V_dad_enhanced != 0 && 1368 dp->dad_ns_lcount > 0 && 1369 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1370 /* 1371 * Sec. 4.1 in RFC 7527 requires transmission of 1372 * additional probes until the loopback condition 1373 * becomes clear when a looped back probe is detected. 1374 */ 1375 log(LOG_ERR, "%s: a looped back NS message is " 1376 "detected during DAD for %s. " 1377 "Another DAD probes are being sent.\n", 1378 if_name(ifa->ifa_ifp), 1379 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1380 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1381 /* 1382 * Send an NS immediately and increase dad_count by 1383 * V_nd6_mmaxtries - 1. 1384 */ 1385 dp->dad_count = 1386 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1387 nd6_dad_starttimer(dp, 1388 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1389 1); 1390 goto done; 1391 } else { 1392 /* 1393 * We are done with DAD. No NA came, no NS came. 1394 * No duplicate address found. Check IFDISABLED flag 1395 * again in case that it is changed between the 1396 * beginning of this function and here. 1397 */ 1398 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1399 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1400 1401 nd6log((LOG_DEBUG, 1402 "%s: DAD complete for %s - no duplicates found\n", 1403 if_name(ifa->ifa_ifp), 1404 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1405 if (dp->dad_ns_lcount > 0) 1406 log(LOG_ERR, "%s: DAD completed while " 1407 "a looped back NS message is detected " 1408 "during DAD for %s.\n", 1409 if_name(ifa->ifa_ifp), 1410 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1411 } 1412 } 1413 err: 1414 nd6_dad_del(dp); 1415 done: 1416 CURVNET_RESTORE(); 1417 } 1418 1419 static void 1420 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1421 { 1422 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1423 struct ifnet *ifp; 1424 char ip6buf[INET6_ADDRSTRLEN]; 1425 1426 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1427 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1428 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1429 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1430 dp->dad_na_icount); 1431 1432 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1433 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1434 1435 ifp = ifa->ifa_ifp; 1436 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1437 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1438 log(LOG_ERR, "%s: manual intervention required\n", 1439 if_name(ifp)); 1440 1441 /* 1442 * If the address is a link-local address formed from an interface 1443 * identifier based on the hardware address which is supposed to be 1444 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1445 * operation on the interface SHOULD be disabled. 1446 * [RFC 4862, Section 5.4.5] 1447 */ 1448 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1449 struct in6_addr in6; 1450 1451 /* 1452 * To avoid over-reaction, we only apply this logic when we are 1453 * very sure that hardware addresses are supposed to be unique. 1454 */ 1455 switch (ifp->if_type) { 1456 case IFT_ETHER: 1457 case IFT_FDDI: 1458 case IFT_ATM: 1459 case IFT_IEEE1394: 1460 case IFT_INFINIBAND: 1461 in6 = ia->ia_addr.sin6_addr; 1462 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1463 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1464 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1465 log(LOG_ERR, "%s: possible hardware address " 1466 "duplication detected, disable IPv6\n", 1467 if_name(ifp)); 1468 } 1469 break; 1470 } 1471 } 1472 } 1473 1474 static void 1475 nd6_dad_ns_output(struct dadq *dp) 1476 { 1477 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1478 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1479 int i; 1480 1481 dp->dad_ns_tcount++; 1482 if ((ifp->if_flags & IFF_UP) == 0) { 1483 return; 1484 } 1485 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1486 return; 1487 } 1488 1489 dp->dad_ns_ocount++; 1490 if (V_dad_enhanced != 0) { 1491 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1492 dp->dad_nonce[i] = arc4random(); 1493 /* 1494 * XXXHRS: Note that in the case that 1495 * DupAddrDetectTransmits > 1, multiple NS messages with 1496 * different nonces can be looped back in an unexpected 1497 * order. The current implementation recognizes only 1498 * the latest nonce on the sender side. Practically it 1499 * should work well in almost all cases. 1500 */ 1501 } 1502 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1503 (uint8_t *)&dp->dad_nonce[0]); 1504 } 1505 1506 static void 1507 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1508 { 1509 struct in6_ifaddr *ia; 1510 struct ifnet *ifp; 1511 const struct in6_addr *taddr6; 1512 struct dadq *dp; 1513 1514 if (ifa == NULL) 1515 panic("ifa == NULL in nd6_dad_ns_input"); 1516 1517 ia = (struct in6_ifaddr *)ifa; 1518 ifp = ifa->ifa_ifp; 1519 taddr6 = &ia->ia_addr.sin6_addr; 1520 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1521 if (V_dad_enhanced == 0) 1522 ndopt_nonce = NULL; 1523 dp = nd6_dad_find(ifa, ndopt_nonce); 1524 if (dp == NULL) 1525 return; 1526 1527 dp->dad_ns_icount++; 1528 nd6_dad_rele(dp); 1529 } 1530 1531 static void 1532 nd6_dad_na_input(struct ifaddr *ifa) 1533 { 1534 struct dadq *dp; 1535 1536 if (ifa == NULL) 1537 panic("ifa == NULL in nd6_dad_na_input"); 1538 1539 dp = nd6_dad_find(ifa, NULL); 1540 if (dp != NULL) { 1541 dp->dad_na_icount++; 1542 nd6_dad_rele(dp); 1543 } 1544 } 1545