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, 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 *); 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 if (lltable_try_set_entry_addr(ifp, ln, lladdr) == 0) { 769 ln = NULL; 770 goto freeit; 771 } 772 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 773 if (is_solicited) 774 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 775 else 776 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 777 if ((ln->ln_router = is_router) != 0) { 778 /* 779 * This means a router's state has changed from 780 * non-reachable to probably reachable, and might 781 * affect the status of associated prefixes.. 782 */ 783 checklink = 1; 784 } 785 } else { 786 int llchange; 787 788 /* 789 * Check if the link-layer address has changed or not. 790 */ 791 if (lladdr == NULL) 792 llchange = 0; 793 else { 794 if (ln->la_flags & LLE_VALID) { 795 if (bcmp(lladdr, &ln->ll_addr, ifp->if_addrlen)) 796 llchange = 1; 797 else 798 llchange = 0; 799 } else 800 llchange = 1; 801 } 802 803 /* 804 * This is VERY complex. Look at it with care. 805 * 806 * override solicit lladdr llchange action 807 * (L: record lladdr) 808 * 809 * 0 0 n -- (2c) 810 * 0 0 y n (2b) L 811 * 0 0 y y (1) REACHABLE->STALE 812 * 0 1 n -- (2c) *->REACHABLE 813 * 0 1 y n (2b) L *->REACHABLE 814 * 0 1 y y (1) REACHABLE->STALE 815 * 1 0 n -- (2a) 816 * 1 0 y n (2a) L 817 * 1 0 y y (2a) L *->STALE 818 * 1 1 n -- (2a) *->REACHABLE 819 * 1 1 y n (2a) L *->REACHABLE 820 * 1 1 y y (2a) L *->REACHABLE 821 */ 822 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 823 /* 824 * If state is REACHABLE, make it STALE. 825 * no other updates should be done. 826 */ 827 if (ln->ln_state == ND6_LLINFO_REACHABLE) 828 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 829 goto freeit; 830 } else if (is_override /* (2a) */ 831 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 832 || lladdr == NULL) { /* (2c) */ 833 /* 834 * Update link-local address, if any. 835 */ 836 if (lladdr != NULL) { 837 int ret; 838 ret = lltable_try_set_entry_addr(ifp, ln,lladdr); 839 if (ret == 0) { 840 ln = NULL; 841 goto freeit; 842 } 843 EVENTHANDLER_INVOKE(lle_event, ln, 844 LLENTRY_RESOLVED); 845 } 846 847 /* 848 * If solicited, make the state REACHABLE. 849 * If not solicited and the link-layer address was 850 * changed, make it STALE. 851 */ 852 if (is_solicited) 853 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 854 else { 855 if (lladdr != NULL && llchange) 856 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 857 } 858 } 859 860 if (ln->ln_router && !is_router) { 861 /* 862 * The peer dropped the router flag. 863 * Remove the sender from the Default Router List and 864 * update the Destination Cache entries. 865 */ 866 struct nd_defrouter *dr; 867 struct in6_addr *in6; 868 869 in6 = &ln->r_l3addr.addr6; 870 871 /* 872 * Lock to protect the default router list. 873 * XXX: this might be unnecessary, since this function 874 * is only called under the network software interrupt 875 * context. However, we keep it just for safety. 876 */ 877 dr = defrouter_lookup(in6, ln->lle_tbl->llt_ifp); 878 if (dr) 879 defrtrlist_del(dr); 880 else if (ND_IFINFO(ln->lle_tbl->llt_ifp)->flags & 881 ND6_IFF_ACCEPT_RTADV) { 882 /* 883 * Even if the neighbor is not in the default 884 * router list, the neighbor may be used 885 * as a next hop for some destinations 886 * (e.g. redirect case). So we must 887 * call rt6_flush explicitly. 888 */ 889 rt6_flush(&ip6->ip6_src, ifp); 890 } 891 } 892 ln->ln_router = is_router; 893 } 894 /* XXX - QL 895 * Does this matter? 896 * rt->rt_flags &= ~RTF_REJECT; 897 */ 898 ln->la_asked = 0; 899 if (ln->la_hold != NULL) 900 nd6_grab_holdchain(ln, &chain, &sin6); 901 freeit: 902 if (ln != NULL) 903 LLE_WUNLOCK(ln); 904 905 if (chain != NULL) 906 nd6_flush_holdchain(ifp, ifp, chain, &sin6); 907 908 if (checklink) 909 pfxlist_onlink_check(); 910 911 m_freem(m); 912 return; 913 914 bad: 915 if (ln != NULL) 916 LLE_WUNLOCK(ln); 917 918 ICMP6STAT_INC(icp6s_badna); 919 m_freem(m); 920 } 921 922 /* 923 * Neighbor advertisement output handling. 924 * 925 * Based on RFC 2461 926 * 927 * the following items are not implemented yet: 928 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 929 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 930 * 931 * tlladdr - 1 if include target link-layer address 932 * sdl0 - sockaddr_dl (= proxy NA) or NULL 933 */ 934 static void 935 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 936 const struct in6_addr *taddr6, u_long flags, int tlladdr, 937 struct sockaddr *sdl0, u_int fibnum) 938 { 939 struct mbuf *m; 940 struct m_tag *mtag; 941 struct ifnet *oifp; 942 struct ip6_hdr *ip6; 943 struct nd_neighbor_advert *nd_na; 944 struct ip6_moptions im6o; 945 struct in6_addr src, daddr6; 946 struct sockaddr_in6 dst_sa; 947 int icmp6len, maxlen, error; 948 caddr_t mac = NULL; 949 struct route_in6 ro; 950 951 bzero(&ro, sizeof(ro)); 952 953 daddr6 = *daddr6_0; /* make a local copy for modification */ 954 955 /* estimate the size of message */ 956 maxlen = sizeof(*ip6) + sizeof(*nd_na); 957 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 958 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 959 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 960 __func__, max_linkhdr, maxlen, MCLBYTES)); 961 962 if (max_linkhdr + maxlen > MHLEN) 963 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 964 else 965 m = m_gethdr(M_NOWAIT, MT_DATA); 966 if (m == NULL) 967 return; 968 M_SETFIB(m, fibnum); 969 970 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 971 m->m_flags |= M_MCAST; 972 im6o.im6o_multicast_ifp = ifp; 973 im6o.im6o_multicast_hlim = 255; 974 im6o.im6o_multicast_loop = 0; 975 } 976 977 icmp6len = sizeof(*nd_na); 978 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 979 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 980 981 /* fill neighbor advertisement packet */ 982 ip6 = mtod(m, struct ip6_hdr *); 983 ip6->ip6_flow = 0; 984 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 985 ip6->ip6_vfc |= IPV6_VERSION; 986 ip6->ip6_nxt = IPPROTO_ICMPV6; 987 ip6->ip6_hlim = 255; 988 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 989 /* reply to DAD */ 990 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 991 daddr6.s6_addr16[1] = 0; 992 daddr6.s6_addr32[1] = 0; 993 daddr6.s6_addr32[2] = 0; 994 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 995 if (in6_setscope(&daddr6, ifp, NULL)) 996 goto bad; 997 998 flags &= ~ND_NA_FLAG_SOLICITED; 999 } 1000 ip6->ip6_dst = daddr6; 1001 bzero(&dst_sa, sizeof(struct sockaddr_in6)); 1002 dst_sa.sin6_family = AF_INET6; 1003 dst_sa.sin6_len = sizeof(struct sockaddr_in6); 1004 dst_sa.sin6_addr = daddr6; 1005 1006 /* 1007 * Select a source whose scope is the same as that of the dest. 1008 */ 1009 bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa)); 1010 oifp = ifp; 1011 error = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, &oifp, &src); 1012 if (error) { 1013 char ip6buf[INET6_ADDRSTRLEN]; 1014 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1015 "determined: dst=%s, error=%d\n", 1016 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), error)); 1017 goto bad; 1018 } 1019 ip6->ip6_src = src; 1020 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1021 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1022 nd_na->nd_na_code = 0; 1023 nd_na->nd_na_target = *taddr6; 1024 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1025 1026 /* 1027 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1028 * see nd6_ns_input() for details. 1029 * Basically, if NS packet is sent to unicast/anycast addr, 1030 * target lladdr option SHOULD NOT be included. 1031 */ 1032 if (tlladdr) { 1033 /* 1034 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1035 * lladdr in sdl0. If we are not proxying (sending NA for 1036 * my address) use lladdr configured for the interface. 1037 */ 1038 if (sdl0 == NULL) { 1039 if (ifp->if_carp) 1040 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1041 if (mac == NULL) 1042 mac = nd6_ifptomac(ifp); 1043 } else if (sdl0->sa_family == AF_LINK) { 1044 struct sockaddr_dl *sdl; 1045 sdl = (struct sockaddr_dl *)sdl0; 1046 if (sdl->sdl_alen == ifp->if_addrlen) 1047 mac = LLADDR(sdl); 1048 } 1049 } 1050 if (tlladdr && mac) { 1051 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1052 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1053 1054 /* roundup to 8 bytes alignment! */ 1055 optlen = (optlen + 7) & ~7; 1056 1057 m->m_pkthdr.len += optlen; 1058 m->m_len += optlen; 1059 icmp6len += optlen; 1060 bzero((caddr_t)nd_opt, optlen); 1061 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1062 nd_opt->nd_opt_len = optlen >> 3; 1063 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1064 } else 1065 flags &= ~ND_NA_FLAG_OVERRIDE; 1066 1067 ip6->ip6_plen = htons((u_short)icmp6len); 1068 nd_na->nd_na_flags_reserved = flags; 1069 nd_na->nd_na_cksum = 0; 1070 nd_na->nd_na_cksum = 1071 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1072 1073 if (send_sendso_input_hook != NULL) { 1074 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1075 sizeof(unsigned short), M_NOWAIT); 1076 if (mtag == NULL) 1077 goto bad; 1078 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1079 m_tag_prepend(m, mtag); 1080 } 1081 1082 ip6_output(m, NULL, &ro, 0, &im6o, NULL, NULL); 1083 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1084 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1085 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1086 1087 /* We don't cache this route. */ 1088 RO_RTFREE(&ro); 1089 1090 return; 1091 1092 bad: 1093 if (ro.ro_rt) { 1094 RTFREE(ro.ro_rt); 1095 } 1096 m_freem(m); 1097 return; 1098 } 1099 1100 #ifndef BURN_BRIDGES 1101 void 1102 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1103 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1104 struct sockaddr *sdl0) 1105 { 1106 1107 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1108 RT_DEFAULT_FIB); 1109 } 1110 #endif 1111 1112 caddr_t 1113 nd6_ifptomac(struct ifnet *ifp) 1114 { 1115 switch (ifp->if_type) { 1116 case IFT_ARCNET: 1117 case IFT_ETHER: 1118 case IFT_FDDI: 1119 case IFT_IEEE1394: 1120 case IFT_L2VLAN: 1121 case IFT_IEEE80211: 1122 case IFT_INFINIBAND: 1123 case IFT_BRIDGE: 1124 case IFT_ISO88025: 1125 return IF_LLADDR(ifp); 1126 default: 1127 return NULL; 1128 } 1129 } 1130 1131 struct dadq { 1132 TAILQ_ENTRY(dadq) dad_list; 1133 struct ifaddr *dad_ifa; 1134 int dad_count; /* max NS to send */ 1135 int dad_ns_tcount; /* # of trials to send NS */ 1136 int dad_ns_ocount; /* NS sent so far */ 1137 int dad_ns_icount; 1138 int dad_na_icount; 1139 int dad_ns_lcount; /* looped back NS */ 1140 int dad_loopbackprobe; /* probing state for loopback detection */ 1141 struct callout dad_timer_ch; 1142 struct vnet *dad_vnet; 1143 u_int dad_refcnt; 1144 #define ND_OPT_NONCE_LEN32 \ 1145 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1146 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1147 }; 1148 1149 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq); 1150 static VNET_DEFINE(struct rwlock, dad_rwlock); 1151 #define V_dadq VNET(dadq) 1152 #define V_dad_rwlock VNET(dad_rwlock) 1153 1154 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1155 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1156 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1157 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1158 1159 static void 1160 nd6_dad_add(struct dadq *dp) 1161 { 1162 1163 DADQ_WLOCK(); 1164 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1165 DADQ_WUNLOCK(); 1166 } 1167 1168 static void 1169 nd6_dad_del(struct dadq *dp) 1170 { 1171 1172 DADQ_WLOCK(); 1173 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1174 DADQ_WUNLOCK(); 1175 nd6_dad_rele(dp); 1176 } 1177 1178 static struct dadq * 1179 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1180 { 1181 struct dadq *dp; 1182 1183 DADQ_RLOCK(); 1184 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1185 if (dp->dad_ifa != ifa) 1186 continue; 1187 /* 1188 * Skip if the nonce matches the received one. 1189 * +2 in the length is required because of type and 1190 * length fields are included in a header. 1191 */ 1192 if (n != NULL && 1193 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1194 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1195 ND_OPT_NONCE_LEN) == 0) { 1196 dp->dad_ns_lcount++; 1197 continue; 1198 } 1199 refcount_acquire(&dp->dad_refcnt); 1200 break; 1201 } 1202 DADQ_RUNLOCK(); 1203 1204 return (dp); 1205 } 1206 1207 static void 1208 nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns) 1209 { 1210 1211 if (send_ns != 0) 1212 nd6_dad_ns_output(dp); 1213 callout_reset(&dp->dad_timer_ch, ticks, 1214 (void (*)(void *))nd6_dad_timer, (void *)dp); 1215 } 1216 1217 static void 1218 nd6_dad_stoptimer(struct dadq *dp) 1219 { 1220 1221 callout_drain(&dp->dad_timer_ch); 1222 } 1223 1224 static void 1225 nd6_dad_rele(struct dadq *dp) 1226 { 1227 1228 if (refcount_release(&dp->dad_refcnt)) { 1229 ifa_free(dp->dad_ifa); 1230 free(dp, M_IP6NDP); 1231 } 1232 } 1233 1234 void 1235 nd6_dad_init(void) 1236 { 1237 1238 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1239 TAILQ_INIT(&V_dadq); 1240 } 1241 1242 /* 1243 * Start Duplicate Address Detection (DAD) for specified interface address. 1244 */ 1245 void 1246 nd6_dad_start(struct ifaddr *ifa, int delay) 1247 { 1248 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1249 struct dadq *dp; 1250 char ip6buf[INET6_ADDRSTRLEN]; 1251 int send_ns; 1252 1253 /* 1254 * If we don't need DAD, don't do it. 1255 * There are several cases: 1256 * - DAD is disabled (ip6_dad_count == 0) 1257 * - the interface address is anycast 1258 */ 1259 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1260 log(LOG_DEBUG, 1261 "nd6_dad_start: called with non-tentative address " 1262 "%s(%s)\n", 1263 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1264 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1265 return; 1266 } 1267 if (ia->ia6_flags & IN6_IFF_ANYCAST) { 1268 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1269 return; 1270 } 1271 if (!V_ip6_dad_count) { 1272 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1273 return; 1274 } 1275 if (ifa->ifa_ifp == NULL) 1276 panic("nd6_dad_start: ifa->ifa_ifp == NULL"); 1277 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) { 1278 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1279 return; 1280 } 1281 if (!(ifa->ifa_ifp->if_flags & IFF_UP) || 1282 !(ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) || 1283 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED)) { 1284 ia->ia6_flags |= IN6_IFF_TENTATIVE; 1285 return; 1286 } 1287 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1288 /* 1289 * DAD already in progress. Let the existing entry 1290 * to finish it. 1291 */ 1292 return; 1293 } 1294 1295 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1296 if (dp == NULL) { 1297 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1298 "%s(%s)\n", 1299 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1300 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1301 return; 1302 } 1303 callout_init(&dp->dad_timer_ch, 0); 1304 #ifdef VIMAGE 1305 dp->dad_vnet = curvnet; 1306 #endif 1307 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1308 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1309 1310 /* 1311 * Send NS packet for DAD, ip6_dad_count times. 1312 * Note that we must delay the first transmission, if this is the 1313 * first packet to be sent from the interface after interface 1314 * (re)initialization. 1315 */ 1316 dp->dad_ifa = ifa; 1317 ifa_ref(dp->dad_ifa); 1318 dp->dad_count = V_ip6_dad_count; 1319 dp->dad_ns_icount = dp->dad_na_icount = 0; 1320 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1321 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1322 refcount_init(&dp->dad_refcnt, 1); 1323 nd6_dad_add(dp); 1324 send_ns = 0; 1325 if (delay == 0) { 1326 send_ns = 1; 1327 delay = (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000; 1328 } 1329 nd6_dad_starttimer(dp, delay, send_ns); 1330 } 1331 1332 /* 1333 * terminate DAD unconditionally. used for address removals. 1334 */ 1335 void 1336 nd6_dad_stop(struct ifaddr *ifa) 1337 { 1338 struct dadq *dp; 1339 1340 dp = nd6_dad_find(ifa, NULL); 1341 if (!dp) { 1342 /* DAD wasn't started yet */ 1343 return; 1344 } 1345 1346 nd6_dad_stoptimer(dp); 1347 1348 /* 1349 * The DAD queue entry may have been removed by nd6_dad_timer() while 1350 * we were waiting for it to stop, so re-do the lookup. 1351 */ 1352 nd6_dad_rele(dp); 1353 if (nd6_dad_find(ifa, NULL) == NULL) 1354 return; 1355 1356 nd6_dad_del(dp); 1357 nd6_dad_rele(dp); 1358 } 1359 1360 static void 1361 nd6_dad_timer(struct dadq *dp) 1362 { 1363 CURVNET_SET(dp->dad_vnet); 1364 struct ifaddr *ifa = dp->dad_ifa; 1365 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1366 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1367 char ip6buf[INET6_ADDRSTRLEN]; 1368 1369 /* Sanity check */ 1370 if (ia == NULL) { 1371 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n"); 1372 goto err; 1373 } 1374 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1375 /* Do not need DAD for ifdisabled interface. */ 1376 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1377 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1378 goto err; 1379 } 1380 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1381 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1382 "%s(%s)\n", 1383 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1384 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1385 goto err; 1386 } 1387 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1388 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1389 "%s(%s)\n", 1390 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1391 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1392 goto err; 1393 } 1394 1395 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1396 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1397 (((ifp->if_flags & IFF_UP) == 0) || 1398 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1399 nd6log((LOG_INFO, "%s: could not run DAD " 1400 "because the interface was down or not running.\n", 1401 if_name(ifa->ifa_ifp))); 1402 goto err; 1403 } 1404 1405 /* Need more checks? */ 1406 if (dp->dad_ns_ocount < dp->dad_count) { 1407 /* 1408 * We have more NS to go. Send NS packet for DAD. 1409 */ 1410 nd6_dad_starttimer(dp, 1411 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1); 1412 goto done; 1413 } else { 1414 /* 1415 * We have transmitted sufficient number of DAD packets. 1416 * See what we've got. 1417 */ 1418 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1419 /* We've seen NS or NA, means DAD has failed. */ 1420 nd6_dad_duplicated(ifa, dp); 1421 else if (V_dad_enhanced != 0 && 1422 dp->dad_ns_lcount > 0 && 1423 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1424 /* 1425 * Sec. 4.1 in RFC 7527 requires transmission of 1426 * additional probes until the loopback condition 1427 * becomes clear when a looped back probe is detected. 1428 */ 1429 log(LOG_ERR, "%s: a looped back NS message is " 1430 "detected during DAD for %s. " 1431 "Another DAD probes are being sent.\n", 1432 if_name(ifa->ifa_ifp), 1433 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1434 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1435 /* 1436 * Send an NS immediately and increase dad_count by 1437 * V_nd6_mmaxtries - 1. 1438 */ 1439 dp->dad_count = 1440 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1441 nd6_dad_starttimer(dp, 1442 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1443 1); 1444 goto done; 1445 } else { 1446 /* 1447 * We are done with DAD. No NA came, no NS came. 1448 * No duplicate address found. Check IFDISABLED flag 1449 * again in case that it is changed between the 1450 * beginning of this function and here. 1451 */ 1452 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1453 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1454 1455 nd6log((LOG_DEBUG, 1456 "%s: DAD complete for %s - no duplicates found\n", 1457 if_name(ifa->ifa_ifp), 1458 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1459 if (dp->dad_ns_lcount > 0) 1460 log(LOG_ERR, "%s: DAD completed while " 1461 "a looped back NS message is detected " 1462 "during DAD for %s.\n", 1463 if_name(ifa->ifa_ifp), 1464 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1465 } 1466 } 1467 err: 1468 nd6_dad_del(dp); 1469 done: 1470 CURVNET_RESTORE(); 1471 } 1472 1473 static void 1474 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1475 { 1476 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1477 struct ifnet *ifp; 1478 char ip6buf[INET6_ADDRSTRLEN]; 1479 1480 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1481 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1482 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1483 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1484 dp->dad_na_icount); 1485 1486 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1487 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1488 1489 ifp = ifa->ifa_ifp; 1490 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1491 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1492 log(LOG_ERR, "%s: manual intervention required\n", 1493 if_name(ifp)); 1494 1495 /* 1496 * If the address is a link-local address formed from an interface 1497 * identifier based on the hardware address which is supposed to be 1498 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1499 * operation on the interface SHOULD be disabled. 1500 * [RFC 4862, Section 5.4.5] 1501 */ 1502 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1503 struct in6_addr in6; 1504 1505 /* 1506 * To avoid over-reaction, we only apply this logic when we are 1507 * very sure that hardware addresses are supposed to be unique. 1508 */ 1509 switch (ifp->if_type) { 1510 case IFT_ETHER: 1511 case IFT_FDDI: 1512 case IFT_ATM: 1513 case IFT_IEEE1394: 1514 case IFT_IEEE80211: 1515 case IFT_INFINIBAND: 1516 in6 = ia->ia_addr.sin6_addr; 1517 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1518 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1519 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1520 log(LOG_ERR, "%s: possible hardware address " 1521 "duplication detected, disable IPv6\n", 1522 if_name(ifp)); 1523 } 1524 break; 1525 } 1526 } 1527 } 1528 1529 static void 1530 nd6_dad_ns_output(struct dadq *dp) 1531 { 1532 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1533 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1534 int i; 1535 1536 dp->dad_ns_tcount++; 1537 if ((ifp->if_flags & IFF_UP) == 0) { 1538 return; 1539 } 1540 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1541 return; 1542 } 1543 1544 dp->dad_ns_ocount++; 1545 if (V_dad_enhanced != 0) { 1546 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1547 dp->dad_nonce[i] = arc4random(); 1548 /* 1549 * XXXHRS: Note that in the case that 1550 * DupAddrDetectTransmits > 1, multiple NS messages with 1551 * different nonces can be looped back in an unexpected 1552 * order. The current implementation recognizes only 1553 * the latest nonce on the sender side. Practically it 1554 * should work well in almost all cases. 1555 */ 1556 } 1557 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1558 (uint8_t *)&dp->dad_nonce[0]); 1559 } 1560 1561 static void 1562 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1563 { 1564 struct in6_ifaddr *ia; 1565 struct ifnet *ifp; 1566 const struct in6_addr *taddr6; 1567 struct dadq *dp; 1568 1569 if (ifa == NULL) 1570 panic("ifa == NULL in nd6_dad_ns_input"); 1571 1572 ia = (struct in6_ifaddr *)ifa; 1573 ifp = ifa->ifa_ifp; 1574 taddr6 = &ia->ia_addr.sin6_addr; 1575 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1576 if (V_dad_enhanced == 0) 1577 ndopt_nonce = NULL; 1578 dp = nd6_dad_find(ifa, ndopt_nonce); 1579 if (dp == NULL) 1580 return; 1581 1582 dp->dad_ns_icount++; 1583 nd6_dad_rele(dp); 1584 } 1585 1586 static void 1587 nd6_dad_na_input(struct ifaddr *ifa) 1588 { 1589 struct dadq *dp; 1590 1591 if (ifa == NULL) 1592 panic("ifa == NULL in nd6_dad_na_input"); 1593 1594 dp = nd6_dad_find(ifa, NULL); 1595 if (dp != NULL) { 1596 dp->dad_na_icount++; 1597 nd6_dad_rele(dp); 1598 } 1599 } 1600