1 /*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $ 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_inet.h" 36 #include "opt_inet6.h" 37 #include "opt_ipsec.h" 38 #include "opt_mpath.h" 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/malloc.h> 43 #include <sys/libkern.h> 44 #include <sys/lock.h> 45 #include <sys/rwlock.h> 46 #include <sys/mbuf.h> 47 #include <sys/socket.h> 48 #include <sys/sockio.h> 49 #include <sys/time.h> 50 #include <sys/kernel.h> 51 #include <sys/errno.h> 52 #include <sys/sysctl.h> 53 #include <sys/syslog.h> 54 #include <sys/queue.h> 55 #include <sys/callout.h> 56 #include <sys/refcount.h> 57 58 #include <net/if.h> 59 #include <net/if_types.h> 60 #include <net/if_dl.h> 61 #include <net/if_var.h> 62 #include <net/route.h> 63 #ifdef RADIX_MPATH 64 #include <net/radix_mpath.h> 65 #endif 66 #include <net/vnet.h> 67 68 #include <netinet/in.h> 69 #include <netinet/in_var.h> 70 #include <net/if_llatbl.h> 71 #include <netinet6/in6_var.h> 72 #include <netinet6/in6_ifattach.h> 73 #include <netinet/ip6.h> 74 #include <netinet6/ip6_var.h> 75 #include <netinet6/scope6_var.h> 76 #include <netinet6/nd6.h> 77 #include <netinet/icmp6.h> 78 #include <netinet/ip_carp.h> 79 #include <netinet6/send.h> 80 81 #define SDL(s) ((struct sockaddr_dl *)s) 82 83 struct dadq; 84 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *); 85 static void nd6_dad_add(struct dadq *dp); 86 static void nd6_dad_del(struct dadq *dp); 87 static void nd6_dad_rele(struct dadq *); 88 static void nd6_dad_starttimer(struct dadq *, int); 89 static void nd6_dad_stoptimer(struct dadq *); 90 static void nd6_dad_timer(struct dadq *); 91 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *); 92 static void nd6_dad_ns_output(struct dadq *, struct ifaddr *); 93 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *); 94 static void nd6_dad_na_input(struct ifaddr *); 95 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 96 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 97 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *, 98 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int); 99 100 static VNET_DEFINE(int, dad_enhanced) = 1; 101 #define V_dad_enhanced VNET(dad_enhanced) 102 103 SYSCTL_DECL(_net_inet6_ip6); 104 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW, 105 &VNET_NAME(dad_enhanced), 0, 106 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD."); 107 108 static VNET_DEFINE(int, dad_maxtry) = 15; /* max # of *tries* to 109 transmit DAD packet */ 110 #define V_dad_maxtry VNET(dad_maxtry) 111 112 /* 113 * Input a Neighbor Solicitation Message. 114 * 115 * Based on RFC 2461 116 * Based on RFC 2462 (duplicate address detection) 117 */ 118 void 119 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 120 { 121 struct ifnet *ifp = m->m_pkthdr.rcvif; 122 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 123 struct nd_neighbor_solicit *nd_ns; 124 struct in6_addr saddr6 = ip6->ip6_src; 125 struct in6_addr daddr6 = ip6->ip6_dst; 126 struct in6_addr taddr6; 127 struct in6_addr myaddr6; 128 char *lladdr = NULL; 129 struct ifaddr *ifa = NULL; 130 int lladdrlen = 0; 131 int anycast = 0, proxy = 0, tentative = 0; 132 int tlladdr; 133 int rflag; 134 union nd_opts ndopts; 135 struct sockaddr_dl proxydl; 136 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 137 138 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 139 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 140 rflag = 0; 141 #ifndef PULLDOWN_TEST 142 IP6_EXTHDR_CHECK(m, off, icmp6len,); 143 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 144 #else 145 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); 146 if (nd_ns == NULL) { 147 ICMP6STAT_INC(icp6s_tooshort); 148 return; 149 } 150 #endif 151 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ 152 taddr6 = nd_ns->nd_ns_target; 153 if (in6_setscope(&taddr6, ifp, NULL) != 0) 154 goto bad; 155 156 if (ip6->ip6_hlim != 255) { 157 nd6log((LOG_ERR, 158 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 159 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 160 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 161 goto bad; 162 } 163 164 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 165 /* dst has to be a solicited node multicast address. */ 166 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 167 /* don't check ifindex portion */ 168 daddr6.s6_addr32[1] == 0 && 169 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 170 daddr6.s6_addr8[12] == 0xff) { 171 ; /* good */ 172 } else { 173 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 174 "(wrong ip6 dst)\n")); 175 goto bad; 176 } 177 } else if (!V_nd6_onlink_ns_rfc4861) { 178 struct sockaddr_in6 src_sa6; 179 180 /* 181 * According to recent IETF discussions, it is not a good idea 182 * to accept a NS from an address which would not be deemed 183 * to be a neighbor otherwise. This point is expected to be 184 * clarified in future revisions of the specification. 185 */ 186 bzero(&src_sa6, sizeof(src_sa6)); 187 src_sa6.sin6_family = AF_INET6; 188 src_sa6.sin6_len = sizeof(src_sa6); 189 src_sa6.sin6_addr = saddr6; 190 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 191 nd6log((LOG_INFO, "nd6_ns_input: " 192 "NS packet from non-neighbor\n")); 193 goto bad; 194 } 195 } 196 197 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 198 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 199 goto bad; 200 } 201 202 icmp6len -= sizeof(*nd_ns); 203 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 204 if (nd6_options(&ndopts) < 0) { 205 nd6log((LOG_INFO, 206 "nd6_ns_input: invalid ND option, ignored\n")); 207 /* nd6_options have incremented stats */ 208 goto freeit; 209 } 210 211 if (ndopts.nd_opts_src_lladdr) { 212 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 213 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 214 } 215 216 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 217 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 218 "(link-layer address option)\n")); 219 goto bad; 220 } 221 222 /* 223 * Attaching target link-layer address to the NA? 224 * (RFC 2461 7.2.4) 225 * 226 * NS IP dst is unicast/anycast MUST NOT add 227 * NS IP dst is solicited-node multicast MUST add 228 * 229 * In implementation, we add target link-layer address by default. 230 * We do not add one in MUST NOT cases. 231 */ 232 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 233 tlladdr = 0; 234 else 235 tlladdr = 1; 236 237 /* 238 * Target address (taddr6) must be either: 239 * (1) Valid unicast/anycast address for my receiving interface, 240 * (2) Unicast address for which I'm offering proxy service, or 241 * (3) "tentative" address on which DAD is being performed. 242 */ 243 /* (1) and (3) check. */ 244 if (ifp->if_carp) 245 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 246 else 247 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 248 249 /* (2) check. */ 250 if (ifa == NULL) { 251 struct route_in6 ro; 252 int need_proxy; 253 254 bzero(&ro, sizeof(ro)); 255 ro.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 256 ro.ro_dst.sin6_family = AF_INET6; 257 ro.ro_dst.sin6_addr = taddr6; 258 259 /* Always use the default FIB. */ 260 #ifdef RADIX_MPATH 261 rtalloc_mpath_fib((struct route *)&ro, ntohl(taddr6.s6_addr32[3]), 262 RT_DEFAULT_FIB); 263 #else 264 in6_rtalloc(&ro, RT_DEFAULT_FIB); 265 #endif 266 need_proxy = (ro.ro_rt && 267 (ro.ro_rt->rt_flags & RTF_ANNOUNCE) != 0 && 268 ro.ro_rt->rt_gateway->sa_family == AF_LINK); 269 if (ro.ro_rt != NULL) { 270 if (need_proxy) 271 proxydl = *SDL(ro.ro_rt->rt_gateway); 272 RTFREE(ro.ro_rt); 273 } 274 if (need_proxy) { 275 /* 276 * proxy NDP for single entry 277 */ 278 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 279 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 280 if (ifa) 281 proxy = 1; 282 } 283 } 284 if (ifa == NULL) { 285 /* 286 * We've got an NS packet, and we don't have that adddress 287 * assigned for us. We MUST silently ignore it. 288 * See RFC2461 7.2.3. 289 */ 290 goto freeit; 291 } 292 myaddr6 = *IFA_IN6(ifa); 293 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 294 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 295 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 296 goto freeit; 297 298 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 299 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 300 "(if %d, NS packet %d)\n", 301 ip6_sprintf(ip6bufs, &taddr6), 302 ifp->if_addrlen, lladdrlen - 2)); 303 goto bad; 304 } 305 306 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 307 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 308 ip6_sprintf(ip6bufs, &saddr6))); 309 goto freeit; 310 } 311 312 /* 313 * We have neighbor solicitation packet, with target address equals to 314 * one of my tentative address. 315 * 316 * src addr how to process? 317 * --- --- 318 * multicast of course, invalid (rejected in ip6_input) 319 * unicast somebody is doing address resolution -> ignore 320 * unspec dup address detection 321 * 322 * The processing is defined in RFC 2462. 323 */ 324 if (tentative) { 325 /* 326 * If source address is unspecified address, it is for 327 * duplicate address detection. 328 * 329 * If not, the packet is for addess resolution; 330 * silently ignore it. 331 */ 332 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 333 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 334 335 goto freeit; 336 } 337 338 /* 339 * If the source address is unspecified address, entries must not 340 * be created or updated. 341 * It looks that sender is performing DAD. Output NA toward 342 * all-node multicast address, to tell the sender that I'm using 343 * the address. 344 * S bit ("solicited") must be zero. 345 */ 346 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 347 struct in6_addr in6_all; 348 349 in6_all = in6addr_linklocal_allnodes; 350 if (in6_setscope(&in6_all, ifp, NULL) != 0) 351 goto bad; 352 nd6_na_output_fib(ifp, &in6_all, &taddr6, 353 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 354 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 355 M_GETFIB(m)); 356 goto freeit; 357 } 358 359 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 360 ND_NEIGHBOR_SOLICIT, 0); 361 362 nd6_na_output_fib(ifp, &saddr6, &taddr6, 363 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 364 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 365 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 366 freeit: 367 if (ifa != NULL) 368 ifa_free(ifa); 369 m_freem(m); 370 return; 371 372 bad: 373 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 374 ip6_sprintf(ip6bufs, &saddr6))); 375 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 376 ip6_sprintf(ip6bufs, &daddr6))); 377 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 378 ip6_sprintf(ip6bufs, &taddr6))); 379 ICMP6STAT_INC(icp6s_badns); 380 if (ifa != NULL) 381 ifa_free(ifa); 382 m_freem(m); 383 } 384 385 /* 386 * Output a Neighbor Solicitation Message. Caller specifies: 387 * - ICMP6 header source IP6 address 388 * - ND6 header target IP6 address 389 * - ND6 header source datalink address 390 * 391 * Based on RFC 2461 392 * Based on RFC 2462 (duplicate address detection) 393 * 394 * ln - for source address determination 395 * nonce - If non-NULL, NS is used for duplicate address detection and 396 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 397 */ 398 static void 399 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 400 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 401 uint8_t *nonce, u_int fibnum) 402 { 403 struct mbuf *m; 404 struct m_tag *mtag; 405 struct ip6_hdr *ip6; 406 struct nd_neighbor_solicit *nd_ns; 407 struct ip6_moptions im6o; 408 int icmp6len; 409 int maxlen; 410 caddr_t mac; 411 struct route_in6 ro; 412 413 if (IN6_IS_ADDR_MULTICAST(taddr6)) 414 return; 415 416 /* estimate the size of message */ 417 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 418 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 419 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 420 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 421 __func__, max_linkhdr, maxlen, MCLBYTES)); 422 423 if (max_linkhdr + maxlen > MHLEN) 424 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 425 else 426 m = m_gethdr(M_NOWAIT, MT_DATA); 427 if (m == NULL) 428 return; 429 M_SETFIB(m, fibnum); 430 431 bzero(&ro, sizeof(ro)); 432 433 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 434 m->m_flags |= M_MCAST; 435 im6o.im6o_multicast_ifp = ifp; 436 im6o.im6o_multicast_hlim = 255; 437 im6o.im6o_multicast_loop = 0; 438 } 439 440 icmp6len = sizeof(*nd_ns); 441 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 442 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 443 444 /* fill neighbor solicitation packet */ 445 ip6 = mtod(m, struct ip6_hdr *); 446 ip6->ip6_flow = 0; 447 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 448 ip6->ip6_vfc |= IPV6_VERSION; 449 /* ip6->ip6_plen will be set later */ 450 ip6->ip6_nxt = IPPROTO_ICMPV6; 451 ip6->ip6_hlim = 255; 452 if (daddr6) 453 ip6->ip6_dst = *daddr6; 454 else { 455 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 456 ip6->ip6_dst.s6_addr16[1] = 0; 457 ip6->ip6_dst.s6_addr32[1] = 0; 458 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 459 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 460 ip6->ip6_dst.s6_addr8[12] = 0xff; 461 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 462 goto bad; 463 } 464 if (nonce == NULL) { 465 struct ifaddr *ifa = NULL; 466 467 /* 468 * RFC2461 7.2.2: 469 * "If the source address of the packet prompting the 470 * solicitation is the same as one of the addresses assigned 471 * to the outgoing interface, that address SHOULD be placed 472 * in the IP Source Address of the outgoing solicitation. 473 * Otherwise, any one of the addresses assigned to the 474 * interface should be used." 475 * 476 * We use the source address for the prompting packet 477 * (saddr6), if saddr6 belongs to the outgoing interface. 478 * Otherwise, we perform the source address selection as usual. 479 */ 480 481 if (saddr6 != NULL) 482 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 483 if (ifa != NULL) { 484 /* ip6_src set already. */ 485 ip6->ip6_src = *saddr6; 486 ifa_free(ifa); 487 } else { 488 int error; 489 struct sockaddr_in6 dst_sa; 490 struct in6_addr src_in; 491 struct ifnet *oifp; 492 493 bzero(&dst_sa, sizeof(dst_sa)); 494 dst_sa.sin6_family = AF_INET6; 495 dst_sa.sin6_len = sizeof(dst_sa); 496 dst_sa.sin6_addr = ip6->ip6_dst; 497 498 oifp = ifp; 499 error = in6_selectsrc(&dst_sa, NULL, 500 NULL, &ro, NULL, &oifp, &src_in); 501 if (error) { 502 char ip6buf[INET6_ADDRSTRLEN]; 503 nd6log((LOG_DEBUG, "%s: source can't be " 504 "determined: dst=%s, error=%d\n", __func__, 505 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), 506 error)); 507 goto bad; 508 } 509 ip6->ip6_src = src_in; 510 } 511 } else { 512 /* 513 * Source address for DAD packet must always be IPv6 514 * unspecified address. (0::0) 515 * We actually don't have to 0-clear the address (we did it 516 * above), but we do so here explicitly to make the intention 517 * clearer. 518 */ 519 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 520 } 521 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 522 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 523 nd_ns->nd_ns_code = 0; 524 nd_ns->nd_ns_reserved = 0; 525 nd_ns->nd_ns_target = *taddr6; 526 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 527 528 /* 529 * Add source link-layer address option. 530 * 531 * spec implementation 532 * --- --- 533 * DAD packet MUST NOT do not add the option 534 * there's no link layer address: 535 * impossible do not add the option 536 * there's link layer address: 537 * Multicast NS MUST add one add the option 538 * Unicast NS SHOULD add one add the option 539 */ 540 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 541 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 542 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 543 /* 8 byte alignments... */ 544 optlen = (optlen + 7) & ~7; 545 546 m->m_pkthdr.len += optlen; 547 m->m_len += optlen; 548 icmp6len += optlen; 549 bzero((caddr_t)nd_opt, optlen); 550 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 551 nd_opt->nd_opt_len = optlen >> 3; 552 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 553 } 554 /* 555 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 556 * This behavior is documented as Enhanced Duplicate Address 557 * Detection in RFC 7527. 558 * net.inet6.ip6.dad_enhanced=0 disables this. 559 */ 560 if (V_dad_enhanced != 0 && nonce != NULL) { 561 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 562 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 563 /* 8-byte alignment is required. */ 564 optlen = (optlen + 7) & ~7; 565 566 m->m_pkthdr.len += optlen; 567 m->m_len += optlen; 568 icmp6len += optlen; 569 bzero((caddr_t)nd_opt, optlen); 570 nd_opt->nd_opt_type = ND_OPT_NONCE; 571 nd_opt->nd_opt_len = optlen >> 3; 572 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 573 } 574 ip6->ip6_plen = htons((u_short)icmp6len); 575 nd_ns->nd_ns_cksum = 0; 576 nd_ns->nd_ns_cksum = 577 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 578 579 if (send_sendso_input_hook != NULL) { 580 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 581 sizeof(unsigned short), M_NOWAIT); 582 if (mtag == NULL) 583 goto bad; 584 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 585 m_tag_prepend(m, mtag); 586 } 587 588 ip6_output(m, NULL, &ro, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 589 &im6o, NULL, NULL); 590 icmp6_ifstat_inc(ifp, ifs6_out_msg); 591 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 592 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 593 594 /* We don't cache this route. */ 595 RO_RTFREE(&ro); 596 597 return; 598 599 bad: 600 if (ro.ro_rt) { 601 RTFREE(ro.ro_rt); 602 } 603 m_freem(m); 604 return; 605 } 606 607 #ifndef BURN_BRIDGES 608 void 609 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 610 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 611 { 612 613 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 614 } 615 #endif 616 /* 617 * Neighbor advertisement input handling. 618 * 619 * Based on RFC 2461 620 * Based on RFC 2462 (duplicate address detection) 621 * 622 * the following items are not implemented yet: 623 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 624 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 625 */ 626 void 627 nd6_na_input(struct mbuf *m, int off, int icmp6len) 628 { 629 struct ifnet *ifp = m->m_pkthdr.rcvif; 630 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 631 struct nd_neighbor_advert *nd_na; 632 struct in6_addr daddr6 = ip6->ip6_dst; 633 struct in6_addr taddr6; 634 int flags; 635 int is_router; 636 int is_solicited; 637 int is_override; 638 char *lladdr = NULL; 639 int lladdrlen = 0; 640 int checklink = 0; 641 struct ifaddr *ifa; 642 struct llentry *ln = NULL; 643 union nd_opts ndopts; 644 struct mbuf *chain = NULL; 645 struct sockaddr_in6 sin6; 646 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 647 648 if (ip6->ip6_hlim != 255) { 649 nd6log((LOG_ERR, 650 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 651 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 652 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 653 goto bad; 654 } 655 656 #ifndef PULLDOWN_TEST 657 IP6_EXTHDR_CHECK(m, off, icmp6len,); 658 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 659 #else 660 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 661 if (nd_na == NULL) { 662 ICMP6STAT_INC(icp6s_tooshort); 663 return; 664 } 665 #endif 666 667 flags = nd_na->nd_na_flags_reserved; 668 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 669 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 670 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 671 memset(&sin6, 0, sizeof(sin6)); 672 673 taddr6 = nd_na->nd_na_target; 674 if (in6_setscope(&taddr6, ifp, NULL)) 675 goto bad; /* XXX: impossible */ 676 677 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 678 nd6log((LOG_ERR, 679 "nd6_na_input: invalid target address %s\n", 680 ip6_sprintf(ip6bufs, &taddr6))); 681 goto bad; 682 } 683 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 684 if (is_solicited) { 685 nd6log((LOG_ERR, 686 "nd6_na_input: a solicited adv is multicasted\n")); 687 goto bad; 688 } 689 690 icmp6len -= sizeof(*nd_na); 691 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 692 if (nd6_options(&ndopts) < 0) { 693 nd6log((LOG_INFO, 694 "nd6_na_input: invalid ND option, ignored\n")); 695 /* nd6_options have incremented stats */ 696 goto freeit; 697 } 698 699 if (ndopts.nd_opts_tgt_lladdr) { 700 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 701 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 702 } 703 704 /* 705 * This effectively disables the DAD check on a non-master CARP 706 * address. 707 */ 708 if (ifp->if_carp) 709 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 710 else 711 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 712 713 /* 714 * Target address matches one of my interface address. 715 * 716 * If my address is tentative, this means that there's somebody 717 * already using the same address as mine. This indicates DAD failure. 718 * This is defined in RFC 2462. 719 * 720 * Otherwise, process as defined in RFC 2461. 721 */ 722 if (ifa 723 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 724 nd6_dad_na_input(ifa); 725 ifa_free(ifa); 726 goto freeit; 727 } 728 729 /* Just for safety, maybe unnecessary. */ 730 if (ifa) { 731 ifa_free(ifa); 732 log(LOG_ERR, 733 "nd6_na_input: duplicate IP6 address %s\n", 734 ip6_sprintf(ip6bufs, &taddr6)); 735 goto freeit; 736 } 737 738 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 739 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 740 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 741 ifp->if_addrlen, lladdrlen - 2)); 742 goto bad; 743 } 744 745 /* 746 * If no neighbor cache entry is found, NA SHOULD silently be 747 * discarded. 748 */ 749 IF_AFDATA_RLOCK(ifp); 750 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 751 IF_AFDATA_RUNLOCK(ifp); 752 if (ln == NULL) { 753 goto freeit; 754 } 755 756 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 757 /* 758 * If the link-layer has address, and no lladdr option came, 759 * discard the packet. 760 */ 761 if (ifp->if_addrlen && lladdr == NULL) { 762 goto freeit; 763 } 764 765 /* 766 * Record link-layer address, and update the state. 767 */ 768 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen); 769 ln->la_flags |= LLE_VALID; 770 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 771 if (is_solicited) { 772 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 773 ln->ln_byhint = 0; 774 } else 775 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 776 if ((ln->ln_router = is_router) != 0) { 777 /* 778 * This means a router's state has changed from 779 * non-reachable to probably reachable, and might 780 * affect the status of associated prefixes.. 781 */ 782 checklink = 1; 783 } 784 } else { 785 int llchange; 786 787 /* 788 * Check if the link-layer address has changed or not. 789 */ 790 if (lladdr == NULL) 791 llchange = 0; 792 else { 793 if (ln->la_flags & LLE_VALID) { 794 if (bcmp(lladdr, &ln->ll_addr, ifp->if_addrlen)) 795 llchange = 1; 796 else 797 llchange = 0; 798 } else 799 llchange = 1; 800 } 801 802 /* 803 * This is VERY complex. Look at it with care. 804 * 805 * override solicit lladdr llchange action 806 * (L: record lladdr) 807 * 808 * 0 0 n -- (2c) 809 * 0 0 y n (2b) L 810 * 0 0 y y (1) REACHABLE->STALE 811 * 0 1 n -- (2c) *->REACHABLE 812 * 0 1 y n (2b) L *->REACHABLE 813 * 0 1 y y (1) REACHABLE->STALE 814 * 1 0 n -- (2a) 815 * 1 0 y n (2a) L 816 * 1 0 y y (2a) L *->STALE 817 * 1 1 n -- (2a) *->REACHABLE 818 * 1 1 y n (2a) L *->REACHABLE 819 * 1 1 y y (2a) L *->REACHABLE 820 */ 821 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 822 /* 823 * If state is REACHABLE, make it STALE. 824 * no other updates should be done. 825 */ 826 if (ln->ln_state == ND6_LLINFO_REACHABLE) 827 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 828 goto freeit; 829 } else if (is_override /* (2a) */ 830 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 831 || lladdr == NULL) { /* (2c) */ 832 /* 833 * Update link-local address, if any. 834 */ 835 if (lladdr != NULL) { 836 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen); 837 ln->la_flags |= LLE_VALID; 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 ln->ln_byhint = 0; 849 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 850 } else { 851 if (lladdr != NULL && llchange) 852 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 853 } 854 } 855 856 if (ln->ln_router && !is_router) { 857 /* 858 * The peer dropped the router flag. 859 * Remove the sender from the Default Router List and 860 * update the Destination Cache entries. 861 */ 862 struct nd_defrouter *dr; 863 struct in6_addr *in6; 864 865 in6 = &ln->r_l3addr.addr6; 866 867 /* 868 * Lock to protect the default router list. 869 * XXX: this might be unnecessary, since this function 870 * is only called under the network software interrupt 871 * context. However, we keep it just for safety. 872 */ 873 dr = defrouter_lookup(in6, ln->lle_tbl->llt_ifp); 874 if (dr) 875 defrtrlist_del(dr); 876 else if (ND_IFINFO(ln->lle_tbl->llt_ifp)->flags & 877 ND6_IFF_ACCEPT_RTADV) { 878 /* 879 * Even if the neighbor is not in the default 880 * router list, the neighbor may be used 881 * as a next hop for some destinations 882 * (e.g. redirect case). So we must 883 * call rt6_flush explicitly. 884 */ 885 rt6_flush(&ip6->ip6_src, ifp); 886 } 887 } 888 ln->ln_router = is_router; 889 } 890 /* XXX - QL 891 * Does this matter? 892 * rt->rt_flags &= ~RTF_REJECT; 893 */ 894 ln->la_asked = 0; 895 if (ln->la_hold != NULL) 896 nd6_grab_holdchain(ln, &chain, &sin6); 897 freeit: 898 if (ln != NULL) 899 LLE_WUNLOCK(ln); 900 901 if (chain != NULL) 902 nd6_flush_holdchain(ifp, 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 ifnet *oifp; 938 struct ip6_hdr *ip6; 939 struct nd_neighbor_advert *nd_na; 940 struct ip6_moptions im6o; 941 struct in6_addr src, daddr6; 942 struct sockaddr_in6 dst_sa; 943 int icmp6len, maxlen, error; 944 caddr_t mac = NULL; 945 struct route_in6 ro; 946 947 bzero(&ro, sizeof(ro)); 948 949 daddr6 = *daddr6_0; /* make a local copy for modification */ 950 951 /* estimate the size of message */ 952 maxlen = sizeof(*ip6) + sizeof(*nd_na); 953 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 954 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 955 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 956 __func__, max_linkhdr, maxlen, MCLBYTES)); 957 958 if (max_linkhdr + maxlen > MHLEN) 959 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 960 else 961 m = m_gethdr(M_NOWAIT, MT_DATA); 962 if (m == NULL) 963 return; 964 M_SETFIB(m, fibnum); 965 966 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 967 m->m_flags |= M_MCAST; 968 im6o.im6o_multicast_ifp = ifp; 969 im6o.im6o_multicast_hlim = 255; 970 im6o.im6o_multicast_loop = 0; 971 } 972 973 icmp6len = sizeof(*nd_na); 974 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 975 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 976 977 /* fill neighbor advertisement packet */ 978 ip6 = mtod(m, struct ip6_hdr *); 979 ip6->ip6_flow = 0; 980 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 981 ip6->ip6_vfc |= IPV6_VERSION; 982 ip6->ip6_nxt = IPPROTO_ICMPV6; 983 ip6->ip6_hlim = 255; 984 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 985 /* reply to DAD */ 986 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 987 daddr6.s6_addr16[1] = 0; 988 daddr6.s6_addr32[1] = 0; 989 daddr6.s6_addr32[2] = 0; 990 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 991 if (in6_setscope(&daddr6, ifp, NULL)) 992 goto bad; 993 994 flags &= ~ND_NA_FLAG_SOLICITED; 995 } 996 ip6->ip6_dst = daddr6; 997 bzero(&dst_sa, sizeof(struct sockaddr_in6)); 998 dst_sa.sin6_family = AF_INET6; 999 dst_sa.sin6_len = sizeof(struct sockaddr_in6); 1000 dst_sa.sin6_addr = daddr6; 1001 1002 /* 1003 * Select a source whose scope is the same as that of the dest. 1004 */ 1005 bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa)); 1006 oifp = ifp; 1007 error = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, &oifp, &src); 1008 if (error) { 1009 char ip6buf[INET6_ADDRSTRLEN]; 1010 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1011 "determined: dst=%s, error=%d\n", 1012 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), error)); 1013 goto bad; 1014 } 1015 ip6->ip6_src = src; 1016 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1017 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1018 nd_na->nd_na_code = 0; 1019 nd_na->nd_na_target = *taddr6; 1020 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1021 1022 /* 1023 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1024 * see nd6_ns_input() for details. 1025 * Basically, if NS packet is sent to unicast/anycast addr, 1026 * target lladdr option SHOULD NOT be included. 1027 */ 1028 if (tlladdr) { 1029 /* 1030 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1031 * lladdr in sdl0. If we are not proxying (sending NA for 1032 * my address) use lladdr configured for the interface. 1033 */ 1034 if (sdl0 == NULL) { 1035 if (ifp->if_carp) 1036 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1037 if (mac == NULL) 1038 mac = nd6_ifptomac(ifp); 1039 } else if (sdl0->sa_family == AF_LINK) { 1040 struct sockaddr_dl *sdl; 1041 sdl = (struct sockaddr_dl *)sdl0; 1042 if (sdl->sdl_alen == ifp->if_addrlen) 1043 mac = LLADDR(sdl); 1044 } 1045 } 1046 if (tlladdr && mac) { 1047 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1048 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1049 1050 /* roundup to 8 bytes alignment! */ 1051 optlen = (optlen + 7) & ~7; 1052 1053 m->m_pkthdr.len += optlen; 1054 m->m_len += optlen; 1055 icmp6len += optlen; 1056 bzero((caddr_t)nd_opt, optlen); 1057 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1058 nd_opt->nd_opt_len = optlen >> 3; 1059 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1060 } else 1061 flags &= ~ND_NA_FLAG_OVERRIDE; 1062 1063 ip6->ip6_plen = htons((u_short)icmp6len); 1064 nd_na->nd_na_flags_reserved = flags; 1065 nd_na->nd_na_cksum = 0; 1066 nd_na->nd_na_cksum = 1067 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1068 1069 if (send_sendso_input_hook != NULL) { 1070 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1071 sizeof(unsigned short), M_NOWAIT); 1072 if (mtag == NULL) 1073 goto bad; 1074 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1075 m_tag_prepend(m, mtag); 1076 } 1077 1078 ip6_output(m, NULL, &ro, 0, &im6o, NULL, NULL); 1079 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1080 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1081 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1082 1083 /* We don't cache this route. */ 1084 RO_RTFREE(&ro); 1085 1086 return; 1087 1088 bad: 1089 if (ro.ro_rt) { 1090 RTFREE(ro.ro_rt); 1091 } 1092 m_freem(m); 1093 return; 1094 } 1095 1096 #ifndef BURN_BRIDGES 1097 void 1098 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1099 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1100 struct sockaddr *sdl0) 1101 { 1102 1103 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1104 RT_DEFAULT_FIB); 1105 } 1106 #endif 1107 1108 caddr_t 1109 nd6_ifptomac(struct ifnet *ifp) 1110 { 1111 switch (ifp->if_type) { 1112 case IFT_ARCNET: 1113 case IFT_ETHER: 1114 case IFT_FDDI: 1115 case IFT_IEEE1394: 1116 case IFT_L2VLAN: 1117 case IFT_IEEE80211: 1118 case IFT_INFINIBAND: 1119 case IFT_BRIDGE: 1120 case IFT_ISO88025: 1121 return IF_LLADDR(ifp); 1122 default: 1123 return NULL; 1124 } 1125 } 1126 1127 struct dadq { 1128 TAILQ_ENTRY(dadq) dad_list; 1129 struct ifaddr *dad_ifa; 1130 int dad_count; /* max NS to send */ 1131 int dad_ns_tcount; /* # of trials to send NS */ 1132 int dad_ns_ocount; /* NS sent so far */ 1133 int dad_ns_icount; 1134 int dad_na_icount; 1135 int dad_ns_lcount; /* looped back NS */ 1136 int dad_loopbackprobe; /* probing state for loopback detection */ 1137 struct callout dad_timer_ch; 1138 struct vnet *dad_vnet; 1139 u_int dad_refcnt; 1140 #define ND_OPT_NONCE_LEN32 \ 1141 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1142 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1143 }; 1144 1145 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq); 1146 static VNET_DEFINE(struct rwlock, dad_rwlock); 1147 #define V_dadq VNET(dadq) 1148 #define V_dad_rwlock VNET(dad_rwlock) 1149 1150 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1151 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1152 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1153 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1154 1155 static void 1156 nd6_dad_add(struct dadq *dp) 1157 { 1158 1159 DADQ_WLOCK(); 1160 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1161 DADQ_WUNLOCK(); 1162 } 1163 1164 static void 1165 nd6_dad_del(struct dadq *dp) 1166 { 1167 1168 DADQ_WLOCK(); 1169 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1170 DADQ_WUNLOCK(); 1171 nd6_dad_rele(dp); 1172 } 1173 1174 static struct dadq * 1175 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1176 { 1177 struct dadq *dp; 1178 1179 DADQ_RLOCK(); 1180 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1181 if (dp->dad_ifa != ifa) 1182 continue; 1183 /* 1184 * Skip if the nonce matches the received one. 1185 * +2 in the length is required because of type and 1186 * length fields are included in a header. 1187 */ 1188 if (n != NULL && 1189 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1190 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1191 ND_OPT_NONCE_LEN) == 0) { 1192 dp->dad_ns_lcount++; 1193 continue; 1194 } 1195 refcount_acquire(&dp->dad_refcnt); 1196 break; 1197 } 1198 DADQ_RUNLOCK(); 1199 1200 return (dp); 1201 } 1202 1203 static void 1204 nd6_dad_starttimer(struct dadq *dp, int ticks) 1205 { 1206 1207 callout_reset(&dp->dad_timer_ch, ticks, 1208 (void (*)(void *))nd6_dad_timer, (void *)dp); 1209 } 1210 1211 static void 1212 nd6_dad_stoptimer(struct dadq *dp) 1213 { 1214 1215 callout_drain(&dp->dad_timer_ch); 1216 } 1217 1218 static void 1219 nd6_dad_rele(struct dadq *dp) 1220 { 1221 1222 if (refcount_release(&dp->dad_refcnt)) { 1223 ifa_free(dp->dad_ifa); 1224 free(dp, M_IP6NDP); 1225 } 1226 } 1227 1228 void 1229 nd6_dad_init(void) 1230 { 1231 1232 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1233 TAILQ_INIT(&V_dadq); 1234 } 1235 1236 /* 1237 * Start Duplicate Address Detection (DAD) for specified interface address. 1238 */ 1239 void 1240 nd6_dad_start(struct ifaddr *ifa, int delay) 1241 { 1242 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1243 struct dadq *dp; 1244 char ip6buf[INET6_ADDRSTRLEN]; 1245 1246 /* 1247 * If we don't need DAD, don't do it. 1248 * There are several cases: 1249 * - DAD is disabled (ip6_dad_count == 0) 1250 * - the interface address is anycast 1251 */ 1252 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1253 log(LOG_DEBUG, 1254 "nd6_dad_start: called with non-tentative address " 1255 "%s(%s)\n", 1256 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1257 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1258 return; 1259 } 1260 if (ia->ia6_flags & IN6_IFF_ANYCAST) { 1261 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1262 return; 1263 } 1264 if (!V_ip6_dad_count) { 1265 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1266 return; 1267 } 1268 if (ifa->ifa_ifp == NULL) 1269 panic("nd6_dad_start: ifa->ifa_ifp == NULL"); 1270 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) { 1271 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1272 return; 1273 } 1274 if (!(ifa->ifa_ifp->if_flags & IFF_UP) || 1275 !(ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) || 1276 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED)) { 1277 ia->ia6_flags |= IN6_IFF_TENTATIVE; 1278 return; 1279 } 1280 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1281 /* DAD already in progress */ 1282 nd6_dad_rele(dp); 1283 return; 1284 } 1285 1286 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1287 if (dp == NULL) { 1288 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1289 "%s(%s)\n", 1290 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1291 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1292 return; 1293 } 1294 callout_init(&dp->dad_timer_ch, 0); 1295 #ifdef VIMAGE 1296 dp->dad_vnet = curvnet; 1297 #endif 1298 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1299 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1300 1301 /* 1302 * Send NS packet for DAD, ip6_dad_count times. 1303 * Note that we must delay the first transmission, if this is the 1304 * first packet to be sent from the interface after interface 1305 * (re)initialization. 1306 */ 1307 dp->dad_ifa = ifa; 1308 ifa_ref(dp->dad_ifa); 1309 dp->dad_count = V_ip6_dad_count; 1310 dp->dad_ns_icount = dp->dad_na_icount = 0; 1311 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1312 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1313 refcount_init(&dp->dad_refcnt, 1); 1314 nd6_dad_add(dp); 1315 if (delay == 0) { 1316 nd6_dad_ns_output(dp, ifa); 1317 nd6_dad_starttimer(dp, 1318 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1319 } else { 1320 nd6_dad_starttimer(dp, delay); 1321 } 1322 } 1323 1324 /* 1325 * terminate DAD unconditionally. used for address removals. 1326 */ 1327 void 1328 nd6_dad_stop(struct ifaddr *ifa) 1329 { 1330 struct dadq *dp; 1331 1332 dp = nd6_dad_find(ifa, NULL); 1333 if (!dp) { 1334 /* DAD wasn't started yet */ 1335 return; 1336 } 1337 1338 nd6_dad_stoptimer(dp); 1339 1340 /* 1341 * The DAD queue entry may have been removed by nd6_dad_timer() while 1342 * we were waiting for it to stop, so re-do the lookup. 1343 */ 1344 nd6_dad_rele(dp); 1345 if (nd6_dad_find(ifa, NULL) == NULL) 1346 return; 1347 1348 nd6_dad_del(dp); 1349 nd6_dad_rele(dp); 1350 } 1351 1352 static void 1353 nd6_dad_timer(struct dadq *dp) 1354 { 1355 CURVNET_SET(dp->dad_vnet); 1356 struct ifaddr *ifa = dp->dad_ifa; 1357 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1358 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1359 char ip6buf[INET6_ADDRSTRLEN]; 1360 1361 /* Sanity check */ 1362 if (ia == NULL) { 1363 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n"); 1364 goto err; 1365 } 1366 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1367 /* Do not need DAD for ifdisabled interface. */ 1368 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1369 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1370 goto err; 1371 } 1372 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1373 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1374 "%s(%s)\n", 1375 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1376 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1377 goto err; 1378 } 1379 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1380 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1381 "%s(%s)\n", 1382 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1383 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1384 goto err; 1385 } 1386 1387 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1388 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1389 (((ifp->if_flags & IFF_UP) == 0) || 1390 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1391 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n", 1392 if_name(ifa->ifa_ifp))); 1393 goto err; 1394 } 1395 1396 /* Need more checks? */ 1397 if (dp->dad_ns_ocount < dp->dad_count) { 1398 /* 1399 * We have more NS to go. Send NS packet for DAD. 1400 */ 1401 nd6_dad_ns_output(dp, ifa); 1402 nd6_dad_starttimer(dp, 1403 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1404 goto done; 1405 } else { 1406 /* 1407 * We have transmitted sufficient number of DAD packets. 1408 * See what we've got. 1409 */ 1410 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1411 /* We've seen NS or NA, means DAD has failed. */ 1412 nd6_dad_duplicated(ifa, dp); 1413 else if (V_dad_enhanced != 0 && 1414 dp->dad_ns_lcount > 0 && 1415 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1416 /* 1417 * Sec. 4.1 in RFC 7527 requires transmission of 1418 * additional probes until the loopback condition 1419 * becomes clear when a looped back probe is detected. 1420 */ 1421 log(LOG_ERR, "%s: a looped back NS message is " 1422 "detected during DAD for %s. " 1423 "Another DAD probes are being sent.\n", 1424 if_name(ifa->ifa_ifp), 1425 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1426 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1427 /* 1428 * Send an NS immediately and increase dad_count by 1429 * V_nd6_mmaxtries - 1. 1430 */ 1431 nd6_dad_ns_output(dp, ifa); 1432 dp->dad_count = 1433 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1434 nd6_dad_starttimer(dp, 1435 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1436 goto done; 1437 } else { 1438 /* 1439 * We are done with DAD. No NA came, no NS came. 1440 * No duplicate address found. Check IFDISABLED flag 1441 * again in case that it is changed between the 1442 * beginning of this function and here. 1443 */ 1444 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1445 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1446 1447 nd6log((LOG_DEBUG, 1448 "%s: DAD complete for %s - no duplicates found\n", 1449 if_name(ifa->ifa_ifp), 1450 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1451 if (dp->dad_ns_lcount > 0) 1452 log(LOG_ERR, "%s: DAD completed while " 1453 "a looped back NS message is detected " 1454 "during DAD for %s.\n", 1455 if_name(ifa->ifa_ifp), 1456 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1457 } 1458 } 1459 err: 1460 nd6_dad_del(dp); 1461 done: 1462 CURVNET_RESTORE(); 1463 } 1464 1465 static void 1466 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1467 { 1468 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1469 struct ifnet *ifp; 1470 char ip6buf[INET6_ADDRSTRLEN]; 1471 1472 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1473 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1474 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1475 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1476 dp->dad_na_icount); 1477 1478 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1479 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1480 1481 ifp = ifa->ifa_ifp; 1482 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1483 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1484 log(LOG_ERR, "%s: manual intervention required\n", 1485 if_name(ifp)); 1486 1487 /* 1488 * If the address is a link-local address formed from an interface 1489 * identifier based on the hardware address which is supposed to be 1490 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1491 * operation on the interface SHOULD be disabled. 1492 * [RFC 4862, Section 5.4.5] 1493 */ 1494 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1495 struct in6_addr in6; 1496 1497 /* 1498 * To avoid over-reaction, we only apply this logic when we are 1499 * very sure that hardware addresses are supposed to be unique. 1500 */ 1501 switch (ifp->if_type) { 1502 case IFT_ETHER: 1503 case IFT_FDDI: 1504 case IFT_ATM: 1505 case IFT_IEEE1394: 1506 case IFT_IEEE80211: 1507 case IFT_INFINIBAND: 1508 in6 = ia->ia_addr.sin6_addr; 1509 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1510 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1511 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1512 log(LOG_ERR, "%s: possible hardware address " 1513 "duplication detected, disable IPv6\n", 1514 if_name(ifp)); 1515 } 1516 break; 1517 } 1518 } 1519 } 1520 1521 static void 1522 nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa) 1523 { 1524 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1525 struct ifnet *ifp = ifa->ifa_ifp; 1526 int i; 1527 1528 dp->dad_ns_tcount++; 1529 if ((ifp->if_flags & IFF_UP) == 0) { 1530 return; 1531 } 1532 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1533 return; 1534 } 1535 1536 dp->dad_ns_ocount++; 1537 if (V_dad_enhanced != 0) { 1538 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1539 dp->dad_nonce[i] = arc4random(); 1540 /* 1541 * XXXHRS: Note that in the case that 1542 * DupAddrDetectTransmits > 1, multiple NS messages with 1543 * different nonces can be looped back in an unexpected 1544 * order. The current implementation recognizes only 1545 * the latest nonce on the sender side. Practically it 1546 * should work well in almost all cases. 1547 */ 1548 } 1549 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1550 (uint8_t *)&dp->dad_nonce[0]); 1551 } 1552 1553 static void 1554 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1555 { 1556 struct in6_ifaddr *ia; 1557 struct ifnet *ifp; 1558 const struct in6_addr *taddr6; 1559 struct dadq *dp; 1560 1561 if (ifa == NULL) 1562 panic("ifa == NULL in nd6_dad_ns_input"); 1563 1564 ia = (struct in6_ifaddr *)ifa; 1565 ifp = ifa->ifa_ifp; 1566 taddr6 = &ia->ia_addr.sin6_addr; 1567 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1568 if (V_dad_enhanced == 0) 1569 ndopt_nonce = NULL; 1570 dp = nd6_dad_find(ifa, ndopt_nonce); 1571 if (dp == NULL) 1572 return; 1573 1574 dp->dad_ns_icount++; 1575 nd6_dad_rele(dp); 1576 } 1577 1578 static void 1579 nd6_dad_na_input(struct ifaddr *ifa) 1580 { 1581 struct dadq *dp; 1582 1583 if (ifa == NULL) 1584 panic("ifa == NULL in nd6_dad_na_input"); 1585 1586 dp = nd6_dad_find(ifa, NULL); 1587 if (dp != NULL) { 1588 dp->dad_na_icount++; 1589 nd6_dad_rele(dp); 1590 } 1591 } 1592