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 sockaddr_dl rt_gateway; 252 struct rt_addrinfo info; 253 struct sockaddr_in6 dst6; 254 255 bzero(&dst6, sizeof(dst6)); 256 dst6.sin6_len = sizeof(struct sockaddr_in6); 257 dst6.sin6_family = AF_INET6; 258 dst6.sin6_addr = taddr6; 259 260 bzero(&rt_gateway, sizeof(rt_gateway)); 261 rt_gateway.sdl_len = sizeof(rt_gateway); 262 bzero(&info, sizeof(info)); 263 info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway; 264 265 /* Always use the default FIB. */ 266 if (rib_lookup_info(RT_DEFAULT_FIB, (struct sockaddr *)&dst6, 267 0, 0, &info) == 0) { 268 if ((info.rti_flags & RTF_ANNOUNCE) != 0 && 269 rt_gateway.sdl_family == AF_LINK) { 270 271 /* 272 * proxy NDP for single entry 273 */ 274 proxydl = *SDL(&rt_gateway); 275 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal( 276 ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 277 if (ifa) 278 proxy = 1; 279 } 280 } 281 } 282 if (ifa == NULL) { 283 /* 284 * We've got an NS packet, and we don't have that adddress 285 * assigned for us. We MUST silently ignore it. 286 * See RFC2461 7.2.3. 287 */ 288 goto freeit; 289 } 290 myaddr6 = *IFA_IN6(ifa); 291 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 292 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 293 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 294 goto freeit; 295 296 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 297 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 298 "(if %d, NS packet %d)\n", 299 ip6_sprintf(ip6bufs, &taddr6), 300 ifp->if_addrlen, lladdrlen - 2)); 301 goto bad; 302 } 303 304 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 305 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 306 ip6_sprintf(ip6bufs, &saddr6))); 307 goto freeit; 308 } 309 310 /* 311 * We have neighbor solicitation packet, with target address equals to 312 * one of my tentative address. 313 * 314 * src addr how to process? 315 * --- --- 316 * multicast of course, invalid (rejected in ip6_input) 317 * unicast somebody is doing address resolution -> ignore 318 * unspec dup address detection 319 * 320 * The processing is defined in RFC 2462. 321 */ 322 if (tentative) { 323 /* 324 * If source address is unspecified address, it is for 325 * duplicate address detection. 326 * 327 * If not, the packet is for addess resolution; 328 * silently ignore it. 329 */ 330 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 331 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 332 333 goto freeit; 334 } 335 336 /* 337 * If the source address is unspecified address, entries must not 338 * be created or updated. 339 * It looks that sender is performing DAD. Output NA toward 340 * all-node multicast address, to tell the sender that I'm using 341 * the address. 342 * S bit ("solicited") must be zero. 343 */ 344 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 345 struct in6_addr in6_all; 346 347 in6_all = in6addr_linklocal_allnodes; 348 if (in6_setscope(&in6_all, ifp, NULL) != 0) 349 goto bad; 350 nd6_na_output_fib(ifp, &in6_all, &taddr6, 351 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 352 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 353 M_GETFIB(m)); 354 goto freeit; 355 } 356 357 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 358 ND_NEIGHBOR_SOLICIT, 0); 359 360 nd6_na_output_fib(ifp, &saddr6, &taddr6, 361 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 362 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 363 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 364 freeit: 365 if (ifa != NULL) 366 ifa_free(ifa); 367 m_freem(m); 368 return; 369 370 bad: 371 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 372 ip6_sprintf(ip6bufs, &saddr6))); 373 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 374 ip6_sprintf(ip6bufs, &daddr6))); 375 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 376 ip6_sprintf(ip6bufs, &taddr6))); 377 ICMP6STAT_INC(icp6s_badns); 378 if (ifa != NULL) 379 ifa_free(ifa); 380 m_freem(m); 381 } 382 383 /* 384 * Output a Neighbor Solicitation Message. Caller specifies: 385 * - ICMP6 header source IP6 address 386 * - ND6 header target IP6 address 387 * - ND6 header source datalink address 388 * 389 * Based on RFC 2461 390 * Based on RFC 2462 (duplicate address detection) 391 * 392 * ln - for source address determination 393 * nonce - If non-NULL, NS is used for duplicate address detection and 394 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 395 */ 396 static void 397 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 398 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 399 uint8_t *nonce, u_int fibnum) 400 { 401 struct mbuf *m; 402 struct m_tag *mtag; 403 struct ip6_hdr *ip6; 404 struct nd_neighbor_solicit *nd_ns; 405 struct ip6_moptions im6o; 406 int icmp6len; 407 int maxlen; 408 caddr_t mac; 409 410 if (IN6_IS_ADDR_MULTICAST(taddr6)) 411 return; 412 413 /* estimate the size of message */ 414 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 415 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 416 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 417 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 418 __func__, max_linkhdr, maxlen, MCLBYTES)); 419 420 if (max_linkhdr + maxlen > MHLEN) 421 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 422 else 423 m = m_gethdr(M_NOWAIT, MT_DATA); 424 if (m == NULL) 425 return; 426 M_SETFIB(m, fibnum); 427 428 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 429 m->m_flags |= M_MCAST; 430 im6o.im6o_multicast_ifp = ifp; 431 im6o.im6o_multicast_hlim = 255; 432 im6o.im6o_multicast_loop = 0; 433 } 434 435 icmp6len = sizeof(*nd_ns); 436 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 437 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 438 439 /* fill neighbor solicitation packet */ 440 ip6 = mtod(m, struct ip6_hdr *); 441 ip6->ip6_flow = 0; 442 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 443 ip6->ip6_vfc |= IPV6_VERSION; 444 /* ip6->ip6_plen will be set later */ 445 ip6->ip6_nxt = IPPROTO_ICMPV6; 446 ip6->ip6_hlim = 255; 447 if (daddr6) 448 ip6->ip6_dst = *daddr6; 449 else { 450 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 451 ip6->ip6_dst.s6_addr16[1] = 0; 452 ip6->ip6_dst.s6_addr32[1] = 0; 453 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 454 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 455 ip6->ip6_dst.s6_addr8[12] = 0xff; 456 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 457 goto bad; 458 } 459 if (nonce == NULL) { 460 struct ifaddr *ifa = NULL; 461 462 /* 463 * RFC2461 7.2.2: 464 * "If the source address of the packet prompting the 465 * solicitation is the same as one of the addresses assigned 466 * to the outgoing interface, that address SHOULD be placed 467 * in the IP Source Address of the outgoing solicitation. 468 * Otherwise, any one of the addresses assigned to the 469 * interface should be used." 470 * 471 * We use the source address for the prompting packet 472 * (saddr6), if saddr6 belongs to the outgoing interface. 473 * Otherwise, we perform the source address selection as usual. 474 */ 475 476 if (saddr6 != NULL) 477 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 478 if (ifa != NULL) { 479 /* ip6_src set already. */ 480 ip6->ip6_src = *saddr6; 481 ifa_free(ifa); 482 } else { 483 int error; 484 struct sockaddr_in6 dst_sa; 485 struct in6_addr src_in; 486 struct ifnet *oifp; 487 488 bzero(&dst_sa, sizeof(dst_sa)); 489 dst_sa.sin6_family = AF_INET6; 490 dst_sa.sin6_len = sizeof(dst_sa); 491 dst_sa.sin6_addr = ip6->ip6_dst; 492 493 oifp = ifp; 494 error = in6_selectsrc(&dst_sa, NULL, 495 NULL, NULL, &oifp, &src_in); 496 if (error) { 497 char ip6buf[INET6_ADDRSTRLEN]; 498 nd6log((LOG_DEBUG, "%s: source can't be " 499 "determined: dst=%s, error=%d\n", __func__, 500 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), 501 error)); 502 goto bad; 503 } 504 ip6->ip6_src = src_in; 505 } 506 } else { 507 /* 508 * Source address for DAD packet must always be IPv6 509 * unspecified address. (0::0) 510 * We actually don't have to 0-clear the address (we did it 511 * above), but we do so here explicitly to make the intention 512 * clearer. 513 */ 514 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 515 } 516 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 517 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 518 nd_ns->nd_ns_code = 0; 519 nd_ns->nd_ns_reserved = 0; 520 nd_ns->nd_ns_target = *taddr6; 521 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 522 523 /* 524 * Add source link-layer address option. 525 * 526 * spec implementation 527 * --- --- 528 * DAD packet MUST NOT do not add the option 529 * there's no link layer address: 530 * impossible do not add the option 531 * there's link layer address: 532 * Multicast NS MUST add one add the option 533 * Unicast NS SHOULD add one add the option 534 */ 535 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 536 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 537 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 538 /* 8 byte alignments... */ 539 optlen = (optlen + 7) & ~7; 540 541 m->m_pkthdr.len += optlen; 542 m->m_len += optlen; 543 icmp6len += optlen; 544 bzero((caddr_t)nd_opt, optlen); 545 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 546 nd_opt->nd_opt_len = optlen >> 3; 547 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 548 } 549 /* 550 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 551 * This behavior is documented as Enhanced Duplicate Address 552 * Detection in RFC 7527. 553 * net.inet6.ip6.dad_enhanced=0 disables this. 554 */ 555 if (V_dad_enhanced != 0 && nonce != NULL) { 556 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 557 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 558 /* 8-byte alignment is required. */ 559 optlen = (optlen + 7) & ~7; 560 561 m->m_pkthdr.len += optlen; 562 m->m_len += optlen; 563 icmp6len += optlen; 564 bzero((caddr_t)nd_opt, optlen); 565 nd_opt->nd_opt_type = ND_OPT_NONCE; 566 nd_opt->nd_opt_len = optlen >> 3; 567 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 568 } 569 ip6->ip6_plen = htons((u_short)icmp6len); 570 nd_ns->nd_ns_cksum = 0; 571 nd_ns->nd_ns_cksum = 572 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 573 574 if (send_sendso_input_hook != NULL) { 575 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 576 sizeof(unsigned short), M_NOWAIT); 577 if (mtag == NULL) 578 goto bad; 579 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 580 m_tag_prepend(m, mtag); 581 } 582 583 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 584 &im6o, NULL, NULL); 585 icmp6_ifstat_inc(ifp, ifs6_out_msg); 586 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 587 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 588 589 return; 590 591 bad: 592 m_freem(m); 593 return; 594 } 595 596 #ifndef BURN_BRIDGES 597 void 598 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 599 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 600 { 601 602 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 603 } 604 #endif 605 /* 606 * Neighbor advertisement input handling. 607 * 608 * Based on RFC 2461 609 * Based on RFC 2462 (duplicate address detection) 610 * 611 * the following items are not implemented yet: 612 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 613 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 614 */ 615 void 616 nd6_na_input(struct mbuf *m, int off, int icmp6len) 617 { 618 struct ifnet *ifp = m->m_pkthdr.rcvif; 619 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 620 struct nd_neighbor_advert *nd_na; 621 struct in6_addr daddr6 = ip6->ip6_dst; 622 struct in6_addr taddr6; 623 int flags; 624 int is_router; 625 int is_solicited; 626 int is_override; 627 char *lladdr = NULL; 628 int lladdrlen = 0; 629 int checklink = 0; 630 struct ifaddr *ifa; 631 struct llentry *ln = NULL; 632 union nd_opts ndopts; 633 struct mbuf *chain = NULL; 634 struct sockaddr_in6 sin6; 635 u_char linkhdr[LLE_MAX_LINKHDR]; 636 size_t linkhdrsize; 637 int lladdr_off; 638 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 639 640 if (ip6->ip6_hlim != 255) { 641 nd6log((LOG_ERR, 642 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 643 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 644 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 645 goto bad; 646 } 647 648 #ifndef PULLDOWN_TEST 649 IP6_EXTHDR_CHECK(m, off, icmp6len,); 650 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 651 #else 652 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 653 if (nd_na == NULL) { 654 ICMP6STAT_INC(icp6s_tooshort); 655 return; 656 } 657 #endif 658 659 flags = nd_na->nd_na_flags_reserved; 660 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 661 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 662 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 663 memset(&sin6, 0, sizeof(sin6)); 664 665 taddr6 = nd_na->nd_na_target; 666 if (in6_setscope(&taddr6, ifp, NULL)) 667 goto bad; /* XXX: impossible */ 668 669 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 670 nd6log((LOG_ERR, 671 "nd6_na_input: invalid target address %s\n", 672 ip6_sprintf(ip6bufs, &taddr6))); 673 goto bad; 674 } 675 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 676 if (is_solicited) { 677 nd6log((LOG_ERR, 678 "nd6_na_input: a solicited adv is multicasted\n")); 679 goto bad; 680 } 681 682 icmp6len -= sizeof(*nd_na); 683 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 684 if (nd6_options(&ndopts) < 0) { 685 nd6log((LOG_INFO, 686 "nd6_na_input: invalid ND option, ignored\n")); 687 /* nd6_options have incremented stats */ 688 goto freeit; 689 } 690 691 if (ndopts.nd_opts_tgt_lladdr) { 692 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 693 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 694 } 695 696 /* 697 * This effectively disables the DAD check on a non-master CARP 698 * address. 699 */ 700 if (ifp->if_carp) 701 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 702 else 703 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 704 705 /* 706 * Target address matches one of my interface address. 707 * 708 * If my address is tentative, this means that there's somebody 709 * already using the same address as mine. This indicates DAD failure. 710 * This is defined in RFC 2462. 711 * 712 * Otherwise, process as defined in RFC 2461. 713 */ 714 if (ifa 715 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 716 nd6_dad_na_input(ifa); 717 ifa_free(ifa); 718 goto freeit; 719 } 720 721 /* Just for safety, maybe unnecessary. */ 722 if (ifa) { 723 ifa_free(ifa); 724 log(LOG_ERR, 725 "nd6_na_input: duplicate IP6 address %s\n", 726 ip6_sprintf(ip6bufs, &taddr6)); 727 goto freeit; 728 } 729 730 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 731 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 732 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 733 ifp->if_addrlen, lladdrlen - 2)); 734 goto bad; 735 } 736 737 /* 738 * If no neighbor cache entry is found, NA SHOULD silently be 739 * discarded. 740 */ 741 IF_AFDATA_RLOCK(ifp); 742 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 743 IF_AFDATA_RUNLOCK(ifp); 744 if (ln == NULL) { 745 goto freeit; 746 } 747 748 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 749 /* 750 * If the link-layer has address, and no lladdr option came, 751 * discard the packet. 752 */ 753 if (ifp->if_addrlen && lladdr == NULL) { 754 goto freeit; 755 } 756 757 /* 758 * Record link-layer address, and update the state. 759 */ 760 linkhdrsize = sizeof(linkhdr); 761 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 762 linkhdr, &linkhdrsize, &lladdr_off) != 0) 763 return; 764 765 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize, 766 lladdr_off) == 0) { 767 ln = NULL; 768 goto freeit; 769 } 770 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 771 if (is_solicited) 772 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 773 else 774 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 775 if ((ln->ln_router = is_router) != 0) { 776 /* 777 * This means a router's state has changed from 778 * non-reachable to probably reachable, and might 779 * affect the status of associated prefixes.. 780 */ 781 checklink = 1; 782 } 783 } else { 784 int llchange; 785 786 /* 787 * Check if the link-layer address has changed or not. 788 */ 789 if (lladdr == NULL) 790 llchange = 0; 791 else { 792 if (ln->la_flags & LLE_VALID) { 793 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 794 llchange = 1; 795 else 796 llchange = 0; 797 } else 798 llchange = 1; 799 } 800 801 /* 802 * This is VERY complex. Look at it with care. 803 * 804 * override solicit lladdr llchange action 805 * (L: record lladdr) 806 * 807 * 0 0 n -- (2c) 808 * 0 0 y n (2b) L 809 * 0 0 y y (1) REACHABLE->STALE 810 * 0 1 n -- (2c) *->REACHABLE 811 * 0 1 y n (2b) L *->REACHABLE 812 * 0 1 y y (1) REACHABLE->STALE 813 * 1 0 n -- (2a) 814 * 1 0 y n (2a) L 815 * 1 0 y y (2a) L *->STALE 816 * 1 1 n -- (2a) *->REACHABLE 817 * 1 1 y n (2a) L *->REACHABLE 818 * 1 1 y y (2a) L *->REACHABLE 819 */ 820 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 821 /* 822 * If state is REACHABLE, make it STALE. 823 * no other updates should be done. 824 */ 825 if (ln->ln_state == ND6_LLINFO_REACHABLE) 826 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 827 goto freeit; 828 } else if (is_override /* (2a) */ 829 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 830 || lladdr == NULL) { /* (2c) */ 831 /* 832 * Update link-local address, if any. 833 */ 834 if (lladdr != NULL) { 835 linkhdrsize = sizeof(linkhdr); 836 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 837 linkhdr, &linkhdrsize, &lladdr_off) != 0) 838 goto freeit; 839 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 840 linkhdrsize, lladdr_off) == 0) { 841 ln = NULL; 842 goto freeit; 843 } 844 EVENTHANDLER_INVOKE(lle_event, ln, 845 LLENTRY_RESOLVED); 846 } 847 848 /* 849 * If solicited, make the state REACHABLE. 850 * If not solicited and the link-layer address was 851 * changed, make it STALE. 852 */ 853 if (is_solicited) 854 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 855 else { 856 if (lladdr != NULL && llchange) 857 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 858 } 859 } 860 861 if (ln->ln_router && !is_router) { 862 /* 863 * The peer dropped the router flag. 864 * Remove the sender from the Default Router List and 865 * update the Destination Cache entries. 866 */ 867 struct nd_defrouter *dr; 868 struct in6_addr *in6; 869 struct ifnet *nd6_ifp; 870 871 in6 = &ln->r_l3addr.addr6; 872 873 /* 874 * Lock to protect the default router list. 875 * XXX: this might be unnecessary, since this function 876 * is only called under the network software interrupt 877 * context. However, we keep it just for safety. 878 */ 879 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 880 dr = defrouter_lookup(in6, nd6_ifp); 881 if (dr) 882 defrtrlist_del(dr); 883 else if (ND_IFINFO(nd6_ifp)->flags & 884 ND6_IFF_ACCEPT_RTADV) { 885 /* 886 * Even if the neighbor is not in the default 887 * router list, the neighbor may be used 888 * as a next hop for some destinations 889 * (e.g. redirect case). So we must 890 * call rt6_flush explicitly. 891 */ 892 rt6_flush(&ip6->ip6_src, ifp); 893 } 894 } 895 ln->ln_router = is_router; 896 } 897 /* XXX - QL 898 * Does this matter? 899 * rt->rt_flags &= ~RTF_REJECT; 900 */ 901 ln->la_asked = 0; 902 if (ln->la_hold != NULL) 903 nd6_grab_holdchain(ln, &chain, &sin6); 904 freeit: 905 if (ln != NULL) 906 LLE_WUNLOCK(ln); 907 908 if (chain != NULL) 909 nd6_flush_holdchain(ifp, ifp, chain, &sin6); 910 911 if (checklink) 912 pfxlist_onlink_check(); 913 914 m_freem(m); 915 return; 916 917 bad: 918 if (ln != NULL) 919 LLE_WUNLOCK(ln); 920 921 ICMP6STAT_INC(icp6s_badna); 922 m_freem(m); 923 } 924 925 /* 926 * Neighbor advertisement output handling. 927 * 928 * Based on RFC 2461 929 * 930 * the following items are not implemented yet: 931 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 932 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 933 * 934 * tlladdr - 1 if include target link-layer address 935 * sdl0 - sockaddr_dl (= proxy NA) or NULL 936 */ 937 static void 938 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 939 const struct in6_addr *taddr6, u_long flags, int tlladdr, 940 struct sockaddr *sdl0, u_int fibnum) 941 { 942 struct mbuf *m; 943 struct m_tag *mtag; 944 struct ifnet *oifp; 945 struct ip6_hdr *ip6; 946 struct nd_neighbor_advert *nd_na; 947 struct ip6_moptions im6o; 948 struct in6_addr src, daddr6; 949 struct sockaddr_in6 dst_sa; 950 int icmp6len, maxlen, error; 951 caddr_t mac = NULL; 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 oifp = ifp; 1010 error = in6_selectsrc(&dst_sa, NULL, NULL, NULL, &oifp, &src); 1011 if (error) { 1012 char ip6buf[INET6_ADDRSTRLEN]; 1013 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1014 "determined: dst=%s, error=%d\n", 1015 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), error)); 1016 goto bad; 1017 } 1018 ip6->ip6_src = src; 1019 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1020 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1021 nd_na->nd_na_code = 0; 1022 nd_na->nd_na_target = *taddr6; 1023 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1024 1025 /* 1026 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1027 * see nd6_ns_input() for details. 1028 * Basically, if NS packet is sent to unicast/anycast addr, 1029 * target lladdr option SHOULD NOT be included. 1030 */ 1031 if (tlladdr) { 1032 /* 1033 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1034 * lladdr in sdl0. If we are not proxying (sending NA for 1035 * my address) use lladdr configured for the interface. 1036 */ 1037 if (sdl0 == NULL) { 1038 if (ifp->if_carp) 1039 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1040 if (mac == NULL) 1041 mac = nd6_ifptomac(ifp); 1042 } else if (sdl0->sa_family == AF_LINK) { 1043 struct sockaddr_dl *sdl; 1044 sdl = (struct sockaddr_dl *)sdl0; 1045 if (sdl->sdl_alen == ifp->if_addrlen) 1046 mac = LLADDR(sdl); 1047 } 1048 } 1049 if (tlladdr && mac) { 1050 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1051 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1052 1053 /* roundup to 8 bytes alignment! */ 1054 optlen = (optlen + 7) & ~7; 1055 1056 m->m_pkthdr.len += optlen; 1057 m->m_len += optlen; 1058 icmp6len += optlen; 1059 bzero((caddr_t)nd_opt, optlen); 1060 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1061 nd_opt->nd_opt_len = optlen >> 3; 1062 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1063 } else 1064 flags &= ~ND_NA_FLAG_OVERRIDE; 1065 1066 ip6->ip6_plen = htons((u_short)icmp6len); 1067 nd_na->nd_na_flags_reserved = flags; 1068 nd_na->nd_na_cksum = 0; 1069 nd_na->nd_na_cksum = 1070 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1071 1072 if (send_sendso_input_hook != NULL) { 1073 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1074 sizeof(unsigned short), M_NOWAIT); 1075 if (mtag == NULL) 1076 goto bad; 1077 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1078 m_tag_prepend(m, mtag); 1079 } 1080 1081 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1082 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1083 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1084 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1085 1086 return; 1087 1088 bad: 1089 m_freem(m); 1090 return; 1091 } 1092 1093 #ifndef BURN_BRIDGES 1094 void 1095 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1096 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1097 struct sockaddr *sdl0) 1098 { 1099 1100 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1101 RT_DEFAULT_FIB); 1102 } 1103 #endif 1104 1105 caddr_t 1106 nd6_ifptomac(struct ifnet *ifp) 1107 { 1108 switch (ifp->if_type) { 1109 case IFT_ARCNET: 1110 case IFT_ETHER: 1111 case IFT_FDDI: 1112 case IFT_IEEE1394: 1113 case IFT_L2VLAN: 1114 case IFT_IEEE80211: 1115 case IFT_INFINIBAND: 1116 case IFT_BRIDGE: 1117 case IFT_ISO88025: 1118 return IF_LLADDR(ifp); 1119 default: 1120 return NULL; 1121 } 1122 } 1123 1124 struct dadq { 1125 TAILQ_ENTRY(dadq) dad_list; 1126 struct ifaddr *dad_ifa; 1127 int dad_count; /* max NS to send */ 1128 int dad_ns_tcount; /* # of trials to send NS */ 1129 int dad_ns_ocount; /* NS sent so far */ 1130 int dad_ns_icount; 1131 int dad_na_icount; 1132 int dad_ns_lcount; /* looped back NS */ 1133 int dad_loopbackprobe; /* probing state for loopback detection */ 1134 struct callout dad_timer_ch; 1135 struct vnet *dad_vnet; 1136 u_int dad_refcnt; 1137 #define ND_OPT_NONCE_LEN32 \ 1138 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1139 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1140 }; 1141 1142 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq); 1143 static VNET_DEFINE(struct rwlock, dad_rwlock); 1144 #define V_dadq VNET(dadq) 1145 #define V_dad_rwlock VNET(dad_rwlock) 1146 1147 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1148 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1149 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1150 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1151 1152 static void 1153 nd6_dad_add(struct dadq *dp) 1154 { 1155 1156 DADQ_WLOCK(); 1157 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1158 DADQ_WUNLOCK(); 1159 } 1160 1161 static void 1162 nd6_dad_del(struct dadq *dp) 1163 { 1164 1165 DADQ_WLOCK(); 1166 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1167 DADQ_WUNLOCK(); 1168 nd6_dad_rele(dp); 1169 } 1170 1171 static struct dadq * 1172 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1173 { 1174 struct dadq *dp; 1175 1176 DADQ_RLOCK(); 1177 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1178 if (dp->dad_ifa != ifa) 1179 continue; 1180 /* 1181 * Skip if the nonce matches the received one. 1182 * +2 in the length is required because of type and 1183 * length fields are included in a header. 1184 */ 1185 if (n != NULL && 1186 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1187 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1188 ND_OPT_NONCE_LEN) == 0) { 1189 dp->dad_ns_lcount++; 1190 continue; 1191 } 1192 refcount_acquire(&dp->dad_refcnt); 1193 break; 1194 } 1195 DADQ_RUNLOCK(); 1196 1197 return (dp); 1198 } 1199 1200 static void 1201 nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns) 1202 { 1203 1204 if (send_ns != 0) 1205 nd6_dad_ns_output(dp); 1206 callout_reset(&dp->dad_timer_ch, ticks, 1207 (void (*)(void *))nd6_dad_timer, (void *)dp); 1208 } 1209 1210 static void 1211 nd6_dad_stoptimer(struct dadq *dp) 1212 { 1213 1214 callout_drain(&dp->dad_timer_ch); 1215 } 1216 1217 static void 1218 nd6_dad_rele(struct dadq *dp) 1219 { 1220 1221 if (refcount_release(&dp->dad_refcnt)) { 1222 ifa_free(dp->dad_ifa); 1223 free(dp, M_IP6NDP); 1224 } 1225 } 1226 1227 void 1228 nd6_dad_init(void) 1229 { 1230 1231 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1232 TAILQ_INIT(&V_dadq); 1233 } 1234 1235 /* 1236 * Start Duplicate Address Detection (DAD) for specified interface address. 1237 */ 1238 void 1239 nd6_dad_start(struct ifaddr *ifa, int delay) 1240 { 1241 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1242 struct dadq *dp; 1243 char ip6buf[INET6_ADDRSTRLEN]; 1244 int send_ns; 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 /* 1282 * DAD already in progress. Let the existing entry 1283 * to finish it. 1284 */ 1285 return; 1286 } 1287 1288 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1289 if (dp == NULL) { 1290 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1291 "%s(%s)\n", 1292 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1293 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1294 return; 1295 } 1296 callout_init(&dp->dad_timer_ch, 0); 1297 #ifdef VIMAGE 1298 dp->dad_vnet = curvnet; 1299 #endif 1300 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1301 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1302 1303 /* 1304 * Send NS packet for DAD, ip6_dad_count times. 1305 * Note that we must delay the first transmission, if this is the 1306 * first packet to be sent from the interface after interface 1307 * (re)initialization. 1308 */ 1309 dp->dad_ifa = ifa; 1310 ifa_ref(dp->dad_ifa); 1311 dp->dad_count = V_ip6_dad_count; 1312 dp->dad_ns_icount = dp->dad_na_icount = 0; 1313 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1314 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1315 refcount_init(&dp->dad_refcnt, 1); 1316 nd6_dad_add(dp); 1317 send_ns = 0; 1318 if (delay == 0) { 1319 send_ns = 1; 1320 delay = (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000; 1321 } 1322 nd6_dad_starttimer(dp, delay, send_ns); 1323 } 1324 1325 /* 1326 * terminate DAD unconditionally. used for address removals. 1327 */ 1328 void 1329 nd6_dad_stop(struct ifaddr *ifa) 1330 { 1331 struct dadq *dp; 1332 1333 dp = nd6_dad_find(ifa, NULL); 1334 if (!dp) { 1335 /* DAD wasn't started yet */ 1336 return; 1337 } 1338 1339 nd6_dad_stoptimer(dp); 1340 1341 /* 1342 * The DAD queue entry may have been removed by nd6_dad_timer() while 1343 * we were waiting for it to stop, so re-do the lookup. 1344 */ 1345 nd6_dad_rele(dp); 1346 if (nd6_dad_find(ifa, NULL) == NULL) 1347 return; 1348 1349 nd6_dad_del(dp); 1350 nd6_dad_rele(dp); 1351 } 1352 1353 static void 1354 nd6_dad_timer(struct dadq *dp) 1355 { 1356 CURVNET_SET(dp->dad_vnet); 1357 struct ifaddr *ifa = dp->dad_ifa; 1358 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1359 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1360 char ip6buf[INET6_ADDRSTRLEN]; 1361 1362 /* Sanity check */ 1363 if (ia == NULL) { 1364 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n"); 1365 goto err; 1366 } 1367 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1368 /* Do not need DAD for ifdisabled interface. */ 1369 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1370 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1371 goto err; 1372 } 1373 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1374 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1375 "%s(%s)\n", 1376 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1377 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1378 goto err; 1379 } 1380 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1381 log(LOG_ERR, "nd6_dad_timer: called with non-tentative 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 1388 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1389 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1390 (((ifp->if_flags & IFF_UP) == 0) || 1391 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1392 nd6log((LOG_INFO, "%s: could not run DAD " 1393 "because the interface was down or not running.\n", 1394 if_name(ifa->ifa_ifp))); 1395 goto err; 1396 } 1397 1398 /* Need more checks? */ 1399 if (dp->dad_ns_ocount < dp->dad_count) { 1400 /* 1401 * We have more NS to go. Send NS packet for DAD. 1402 */ 1403 nd6_dad_starttimer(dp, 1404 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1); 1405 goto done; 1406 } else { 1407 /* 1408 * We have transmitted sufficient number of DAD packets. 1409 * See what we've got. 1410 */ 1411 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1412 /* We've seen NS or NA, means DAD has failed. */ 1413 nd6_dad_duplicated(ifa, dp); 1414 else if (V_dad_enhanced != 0 && 1415 dp->dad_ns_lcount > 0 && 1416 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1417 /* 1418 * Sec. 4.1 in RFC 7527 requires transmission of 1419 * additional probes until the loopback condition 1420 * becomes clear when a looped back probe is detected. 1421 */ 1422 log(LOG_ERR, "%s: a looped back NS message is " 1423 "detected during DAD for %s. " 1424 "Another DAD probes are being sent.\n", 1425 if_name(ifa->ifa_ifp), 1426 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1427 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1428 /* 1429 * Send an NS immediately and increase dad_count by 1430 * V_nd6_mmaxtries - 1. 1431 */ 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 1); 1437 goto done; 1438 } else { 1439 /* 1440 * We are done with DAD. No NA came, no NS came. 1441 * No duplicate address found. Check IFDISABLED flag 1442 * again in case that it is changed between the 1443 * beginning of this function and here. 1444 */ 1445 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1446 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1447 1448 nd6log((LOG_DEBUG, 1449 "%s: DAD complete for %s - no duplicates found\n", 1450 if_name(ifa->ifa_ifp), 1451 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1452 if (dp->dad_ns_lcount > 0) 1453 log(LOG_ERR, "%s: DAD completed while " 1454 "a looped back NS message is detected " 1455 "during DAD for %s.\n", 1456 if_name(ifa->ifa_ifp), 1457 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1458 } 1459 } 1460 err: 1461 nd6_dad_del(dp); 1462 done: 1463 CURVNET_RESTORE(); 1464 } 1465 1466 static void 1467 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1468 { 1469 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1470 struct ifnet *ifp; 1471 char ip6buf[INET6_ADDRSTRLEN]; 1472 1473 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1474 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1475 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1476 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1477 dp->dad_na_icount); 1478 1479 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1480 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1481 1482 ifp = ifa->ifa_ifp; 1483 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1484 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1485 log(LOG_ERR, "%s: manual intervention required\n", 1486 if_name(ifp)); 1487 1488 /* 1489 * If the address is a link-local address formed from an interface 1490 * identifier based on the hardware address which is supposed to be 1491 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1492 * operation on the interface SHOULD be disabled. 1493 * [RFC 4862, Section 5.4.5] 1494 */ 1495 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1496 struct in6_addr in6; 1497 1498 /* 1499 * To avoid over-reaction, we only apply this logic when we are 1500 * very sure that hardware addresses are supposed to be unique. 1501 */ 1502 switch (ifp->if_type) { 1503 case IFT_ETHER: 1504 case IFT_FDDI: 1505 case IFT_ATM: 1506 case IFT_IEEE1394: 1507 case IFT_IEEE80211: 1508 case IFT_INFINIBAND: 1509 in6 = ia->ia_addr.sin6_addr; 1510 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1511 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1512 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1513 log(LOG_ERR, "%s: possible hardware address " 1514 "duplication detected, disable IPv6\n", 1515 if_name(ifp)); 1516 } 1517 break; 1518 } 1519 } 1520 } 1521 1522 static void 1523 nd6_dad_ns_output(struct dadq *dp) 1524 { 1525 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1526 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1527 int i; 1528 1529 dp->dad_ns_tcount++; 1530 if ((ifp->if_flags & IFF_UP) == 0) { 1531 return; 1532 } 1533 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1534 return; 1535 } 1536 1537 dp->dad_ns_ocount++; 1538 if (V_dad_enhanced != 0) { 1539 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1540 dp->dad_nonce[i] = arc4random(); 1541 /* 1542 * XXXHRS: Note that in the case that 1543 * DupAddrDetectTransmits > 1, multiple NS messages with 1544 * different nonces can be looped back in an unexpected 1545 * order. The current implementation recognizes only 1546 * the latest nonce on the sender side. Practically it 1547 * should work well in almost all cases. 1548 */ 1549 } 1550 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1551 (uint8_t *)&dp->dad_nonce[0]); 1552 } 1553 1554 static void 1555 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1556 { 1557 struct in6_ifaddr *ia; 1558 struct ifnet *ifp; 1559 const struct in6_addr *taddr6; 1560 struct dadq *dp; 1561 1562 if (ifa == NULL) 1563 panic("ifa == NULL in nd6_dad_ns_input"); 1564 1565 ia = (struct in6_ifaddr *)ifa; 1566 ifp = ifa->ifa_ifp; 1567 taddr6 = &ia->ia_addr.sin6_addr; 1568 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1569 if (V_dad_enhanced == 0) 1570 ndopt_nonce = NULL; 1571 dp = nd6_dad_find(ifa, ndopt_nonce); 1572 if (dp == NULL) 1573 return; 1574 1575 dp->dad_ns_icount++; 1576 nd6_dad_rele(dp); 1577 } 1578 1579 static void 1580 nd6_dad_na_input(struct ifaddr *ifa) 1581 { 1582 struct dadq *dp; 1583 1584 if (ifa == NULL) 1585 panic("ifa == NULL in nd6_dad_na_input"); 1586 1587 dp = nd6_dad_find(ifa, NULL); 1588 if (dp != NULL) { 1589 dp->dad_na_icount++; 1590 nd6_dad_rele(dp); 1591 } 1592 } 1593