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 in6_addr dst6, src6; 485 uint32_t scopeid; 486 487 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); 488 error = in6_selectsrc_addr(RT_DEFAULT_FIB, &dst6, 489 scopeid, ifp, &src6, NULL); 490 if (error) { 491 char ip6buf[INET6_ADDRSTRLEN]; 492 nd6log((LOG_DEBUG, "%s: source can't be " 493 "determined: dst=%s, error=%d\n", __func__, 494 ip6_sprintf(ip6buf, &dst6), 495 error)); 496 goto bad; 497 } 498 ip6->ip6_src = src6; 499 } 500 } else { 501 /* 502 * Source address for DAD packet must always be IPv6 503 * unspecified address. (0::0) 504 * We actually don't have to 0-clear the address (we did it 505 * above), but we do so here explicitly to make the intention 506 * clearer. 507 */ 508 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 509 } 510 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 511 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 512 nd_ns->nd_ns_code = 0; 513 nd_ns->nd_ns_reserved = 0; 514 nd_ns->nd_ns_target = *taddr6; 515 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 516 517 /* 518 * Add source link-layer address option. 519 * 520 * spec implementation 521 * --- --- 522 * DAD packet MUST NOT do not add the option 523 * there's no link layer address: 524 * impossible do not add the option 525 * there's link layer address: 526 * Multicast NS MUST add one add the option 527 * Unicast NS SHOULD add one add the option 528 */ 529 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 530 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 531 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 532 /* 8 byte alignments... */ 533 optlen = (optlen + 7) & ~7; 534 535 m->m_pkthdr.len += optlen; 536 m->m_len += optlen; 537 icmp6len += optlen; 538 bzero((caddr_t)nd_opt, optlen); 539 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 540 nd_opt->nd_opt_len = optlen >> 3; 541 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 542 } 543 /* 544 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 545 * This behavior is documented as Enhanced Duplicate Address 546 * Detection in RFC 7527. 547 * net.inet6.ip6.dad_enhanced=0 disables this. 548 */ 549 if (V_dad_enhanced != 0 && nonce != NULL) { 550 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 551 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 552 /* 8-byte alignment is required. */ 553 optlen = (optlen + 7) & ~7; 554 555 m->m_pkthdr.len += optlen; 556 m->m_len += optlen; 557 icmp6len += optlen; 558 bzero((caddr_t)nd_opt, optlen); 559 nd_opt->nd_opt_type = ND_OPT_NONCE; 560 nd_opt->nd_opt_len = optlen >> 3; 561 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 562 } 563 ip6->ip6_plen = htons((u_short)icmp6len); 564 nd_ns->nd_ns_cksum = 0; 565 nd_ns->nd_ns_cksum = 566 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 567 568 if (send_sendso_input_hook != NULL) { 569 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 570 sizeof(unsigned short), M_NOWAIT); 571 if (mtag == NULL) 572 goto bad; 573 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 574 m_tag_prepend(m, mtag); 575 } 576 577 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 578 &im6o, NULL, NULL); 579 icmp6_ifstat_inc(ifp, ifs6_out_msg); 580 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 581 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 582 583 return; 584 585 bad: 586 m_freem(m); 587 } 588 589 #ifndef BURN_BRIDGES 590 void 591 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 592 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 593 { 594 595 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 596 } 597 #endif 598 /* 599 * Neighbor advertisement input handling. 600 * 601 * Based on RFC 2461 602 * Based on RFC 2462 (duplicate address detection) 603 * 604 * the following items are not implemented yet: 605 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 606 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 607 */ 608 void 609 nd6_na_input(struct mbuf *m, int off, int icmp6len) 610 { 611 struct ifnet *ifp = m->m_pkthdr.rcvif; 612 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 613 struct nd_neighbor_advert *nd_na; 614 struct in6_addr daddr6 = ip6->ip6_dst; 615 struct in6_addr taddr6; 616 int flags; 617 int is_router; 618 int is_solicited; 619 int is_override; 620 char *lladdr = NULL; 621 int lladdrlen = 0; 622 int checklink = 0; 623 struct ifaddr *ifa; 624 struct llentry *ln = NULL; 625 union nd_opts ndopts; 626 struct mbuf *chain = NULL; 627 struct sockaddr_in6 sin6; 628 u_char linkhdr[LLE_MAX_LINKHDR]; 629 size_t linkhdrsize; 630 int lladdr_off; 631 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 632 633 if (ip6->ip6_hlim != 255) { 634 nd6log((LOG_ERR, 635 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 636 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 637 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 638 goto bad; 639 } 640 641 #ifndef PULLDOWN_TEST 642 IP6_EXTHDR_CHECK(m, off, icmp6len,); 643 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 644 #else 645 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 646 if (nd_na == NULL) { 647 ICMP6STAT_INC(icp6s_tooshort); 648 return; 649 } 650 #endif 651 652 flags = nd_na->nd_na_flags_reserved; 653 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 654 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 655 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 656 memset(&sin6, 0, sizeof(sin6)); 657 658 taddr6 = nd_na->nd_na_target; 659 if (in6_setscope(&taddr6, ifp, NULL)) 660 goto bad; /* XXX: impossible */ 661 662 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 663 nd6log((LOG_ERR, 664 "nd6_na_input: invalid target address %s\n", 665 ip6_sprintf(ip6bufs, &taddr6))); 666 goto bad; 667 } 668 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 669 if (is_solicited) { 670 nd6log((LOG_ERR, 671 "nd6_na_input: a solicited adv is multicasted\n")); 672 goto bad; 673 } 674 675 icmp6len -= sizeof(*nd_na); 676 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 677 if (nd6_options(&ndopts) < 0) { 678 nd6log((LOG_INFO, 679 "nd6_na_input: invalid ND option, ignored\n")); 680 /* nd6_options have incremented stats */ 681 goto freeit; 682 } 683 684 if (ndopts.nd_opts_tgt_lladdr) { 685 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 686 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 687 } 688 689 /* 690 * This effectively disables the DAD check on a non-master CARP 691 * address. 692 */ 693 if (ifp->if_carp) 694 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 695 else 696 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 697 698 /* 699 * Target address matches one of my interface address. 700 * 701 * If my address is tentative, this means that there's somebody 702 * already using the same address as mine. This indicates DAD failure. 703 * This is defined in RFC 2462. 704 * 705 * Otherwise, process as defined in RFC 2461. 706 */ 707 if (ifa 708 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 709 nd6_dad_na_input(ifa); 710 ifa_free(ifa); 711 goto freeit; 712 } 713 714 /* Just for safety, maybe unnecessary. */ 715 if (ifa) { 716 ifa_free(ifa); 717 log(LOG_ERR, 718 "nd6_na_input: duplicate IP6 address %s\n", 719 ip6_sprintf(ip6bufs, &taddr6)); 720 goto freeit; 721 } 722 723 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 724 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 725 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 726 ifp->if_addrlen, lladdrlen - 2)); 727 goto bad; 728 } 729 730 /* 731 * If no neighbor cache entry is found, NA SHOULD silently be 732 * discarded. 733 */ 734 IF_AFDATA_RLOCK(ifp); 735 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 736 IF_AFDATA_RUNLOCK(ifp); 737 if (ln == NULL) { 738 goto freeit; 739 } 740 741 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 742 /* 743 * If the link-layer has address, and no lladdr option came, 744 * discard the packet. 745 */ 746 if (ifp->if_addrlen && lladdr == NULL) { 747 goto freeit; 748 } 749 750 /* 751 * Record link-layer address, and update the state. 752 */ 753 linkhdrsize = sizeof(linkhdr); 754 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 755 linkhdr, &linkhdrsize, &lladdr_off) != 0) 756 return; 757 758 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize, 759 lladdr_off) == 0) { 760 ln = NULL; 761 goto freeit; 762 } 763 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 764 if (is_solicited) 765 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 766 else 767 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 768 if ((ln->ln_router = is_router) != 0) { 769 /* 770 * This means a router's state has changed from 771 * non-reachable to probably reachable, and might 772 * affect the status of associated prefixes.. 773 */ 774 checklink = 1; 775 } 776 } else { 777 int llchange; 778 779 /* 780 * Check if the link-layer address has changed or not. 781 */ 782 if (lladdr == NULL) 783 llchange = 0; 784 else { 785 if (ln->la_flags & LLE_VALID) { 786 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 787 llchange = 1; 788 else 789 llchange = 0; 790 } else 791 llchange = 1; 792 } 793 794 /* 795 * This is VERY complex. Look at it with care. 796 * 797 * override solicit lladdr llchange action 798 * (L: record lladdr) 799 * 800 * 0 0 n -- (2c) 801 * 0 0 y n (2b) L 802 * 0 0 y y (1) REACHABLE->STALE 803 * 0 1 n -- (2c) *->REACHABLE 804 * 0 1 y n (2b) L *->REACHABLE 805 * 0 1 y y (1) REACHABLE->STALE 806 * 1 0 n -- (2a) 807 * 1 0 y n (2a) L 808 * 1 0 y y (2a) L *->STALE 809 * 1 1 n -- (2a) *->REACHABLE 810 * 1 1 y n (2a) L *->REACHABLE 811 * 1 1 y y (2a) L *->REACHABLE 812 */ 813 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 814 /* 815 * If state is REACHABLE, make it STALE. 816 * no other updates should be done. 817 */ 818 if (ln->ln_state == ND6_LLINFO_REACHABLE) 819 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 820 goto freeit; 821 } else if (is_override /* (2a) */ 822 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 823 || lladdr == NULL) { /* (2c) */ 824 /* 825 * Update link-local address, if any. 826 */ 827 if (lladdr != NULL) { 828 linkhdrsize = sizeof(linkhdr); 829 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 830 linkhdr, &linkhdrsize, &lladdr_off) != 0) 831 goto freeit; 832 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 833 linkhdrsize, lladdr_off) == 0) { 834 ln = NULL; 835 goto freeit; 836 } 837 EVENTHANDLER_INVOKE(lle_event, ln, 838 LLENTRY_RESOLVED); 839 } 840 841 /* 842 * If solicited, make the state REACHABLE. 843 * If not solicited and the link-layer address was 844 * changed, make it STALE. 845 */ 846 if (is_solicited) 847 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 848 else { 849 if (lladdr != NULL && llchange) 850 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 851 } 852 } 853 854 if (ln->ln_router && !is_router) { 855 /* 856 * The peer dropped the router flag. 857 * Remove the sender from the Default Router List and 858 * update the Destination Cache entries. 859 */ 860 struct ifnet *nd6_ifp; 861 862 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 863 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 864 (ND_IFINFO(nd6_ifp)->flags & 865 ND6_IFF_ACCEPT_RTADV) != 0) 866 /* 867 * Even if the neighbor is not in the default 868 * router list, the neighbor may be used as a 869 * next hop for some destinations (e.g. redirect 870 * case). So we must call rt6_flush explicitly. 871 */ 872 rt6_flush(&ip6->ip6_src, ifp); 873 } 874 ln->ln_router = is_router; 875 } 876 /* XXX - QL 877 * Does this matter? 878 * rt->rt_flags &= ~RTF_REJECT; 879 */ 880 ln->la_asked = 0; 881 if (ln->la_hold != NULL) 882 nd6_grab_holdchain(ln, &chain, &sin6); 883 freeit: 884 if (ln != NULL) 885 LLE_WUNLOCK(ln); 886 887 if (chain != NULL) 888 nd6_flush_holdchain(ifp, ifp, chain, &sin6); 889 890 if (checklink) 891 pfxlist_onlink_check(); 892 893 m_freem(m); 894 return; 895 896 bad: 897 if (ln != NULL) 898 LLE_WUNLOCK(ln); 899 900 ICMP6STAT_INC(icp6s_badna); 901 m_freem(m); 902 } 903 904 /* 905 * Neighbor advertisement output handling. 906 * 907 * Based on RFC 2461 908 * 909 * the following items are not implemented yet: 910 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 911 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 912 * 913 * tlladdr - 1 if include target link-layer address 914 * sdl0 - sockaddr_dl (= proxy NA) or NULL 915 */ 916 static void 917 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 918 const struct in6_addr *taddr6, u_long flags, int tlladdr, 919 struct sockaddr *sdl0, u_int fibnum) 920 { 921 struct mbuf *m; 922 struct m_tag *mtag; 923 struct ip6_hdr *ip6; 924 struct nd_neighbor_advert *nd_na; 925 struct ip6_moptions im6o; 926 struct in6_addr daddr6, dst6, src6; 927 uint32_t scopeid; 928 929 int icmp6len, maxlen, error; 930 caddr_t mac = NULL; 931 932 daddr6 = *daddr6_0; /* make a local copy for modification */ 933 934 /* estimate the size of message */ 935 maxlen = sizeof(*ip6) + sizeof(*nd_na); 936 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 937 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 938 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 939 __func__, max_linkhdr, maxlen, MCLBYTES)); 940 941 if (max_linkhdr + maxlen > MHLEN) 942 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 943 else 944 m = m_gethdr(M_NOWAIT, MT_DATA); 945 if (m == NULL) 946 return; 947 M_SETFIB(m, fibnum); 948 949 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 950 m->m_flags |= M_MCAST; 951 im6o.im6o_multicast_ifp = ifp; 952 im6o.im6o_multicast_hlim = 255; 953 im6o.im6o_multicast_loop = 0; 954 } 955 956 icmp6len = sizeof(*nd_na); 957 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 958 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 959 960 /* fill neighbor advertisement packet */ 961 ip6 = mtod(m, struct ip6_hdr *); 962 ip6->ip6_flow = 0; 963 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 964 ip6->ip6_vfc |= IPV6_VERSION; 965 ip6->ip6_nxt = IPPROTO_ICMPV6; 966 ip6->ip6_hlim = 255; 967 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 968 /* reply to DAD */ 969 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 970 daddr6.s6_addr16[1] = 0; 971 daddr6.s6_addr32[1] = 0; 972 daddr6.s6_addr32[2] = 0; 973 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 974 if (in6_setscope(&daddr6, ifp, NULL)) 975 goto bad; 976 977 flags &= ~ND_NA_FLAG_SOLICITED; 978 } 979 ip6->ip6_dst = daddr6; 980 981 /* 982 * Select a source whose scope is the same as that of the dest. 983 */ 984 in6_splitscope(&daddr6, &dst6, &scopeid); 985 error = in6_selectsrc_addr(RT_DEFAULT_FIB, &dst6, 986 scopeid, ifp, &src6, NULL); 987 if (error) { 988 char ip6buf[INET6_ADDRSTRLEN]; 989 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 990 "determined: dst=%s, error=%d\n", 991 ip6_sprintf(ip6buf, &daddr6), error)); 992 goto bad; 993 } 994 ip6->ip6_src = src6; 995 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 996 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 997 nd_na->nd_na_code = 0; 998 nd_na->nd_na_target = *taddr6; 999 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1000 1001 /* 1002 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1003 * see nd6_ns_input() for details. 1004 * Basically, if NS packet is sent to unicast/anycast addr, 1005 * target lladdr option SHOULD NOT be included. 1006 */ 1007 if (tlladdr) { 1008 /* 1009 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1010 * lladdr in sdl0. If we are not proxying (sending NA for 1011 * my address) use lladdr configured for the interface. 1012 */ 1013 if (sdl0 == NULL) { 1014 if (ifp->if_carp) 1015 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1016 if (mac == NULL) 1017 mac = nd6_ifptomac(ifp); 1018 } else if (sdl0->sa_family == AF_LINK) { 1019 struct sockaddr_dl *sdl; 1020 sdl = (struct sockaddr_dl *)sdl0; 1021 if (sdl->sdl_alen == ifp->if_addrlen) 1022 mac = LLADDR(sdl); 1023 } 1024 } 1025 if (tlladdr && mac) { 1026 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1027 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1028 1029 /* roundup to 8 bytes alignment! */ 1030 optlen = (optlen + 7) & ~7; 1031 1032 m->m_pkthdr.len += optlen; 1033 m->m_len += optlen; 1034 icmp6len += optlen; 1035 bzero((caddr_t)nd_opt, optlen); 1036 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1037 nd_opt->nd_opt_len = optlen >> 3; 1038 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1039 } else 1040 flags &= ~ND_NA_FLAG_OVERRIDE; 1041 1042 ip6->ip6_plen = htons((u_short)icmp6len); 1043 nd_na->nd_na_flags_reserved = flags; 1044 nd_na->nd_na_cksum = 0; 1045 nd_na->nd_na_cksum = 1046 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1047 1048 if (send_sendso_input_hook != NULL) { 1049 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1050 sizeof(unsigned short), M_NOWAIT); 1051 if (mtag == NULL) 1052 goto bad; 1053 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1054 m_tag_prepend(m, mtag); 1055 } 1056 1057 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1058 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1059 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1060 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1061 1062 return; 1063 1064 bad: 1065 m_freem(m); 1066 } 1067 1068 #ifndef BURN_BRIDGES 1069 void 1070 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1071 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1072 struct sockaddr *sdl0) 1073 { 1074 1075 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1076 RT_DEFAULT_FIB); 1077 } 1078 #endif 1079 1080 caddr_t 1081 nd6_ifptomac(struct ifnet *ifp) 1082 { 1083 switch (ifp->if_type) { 1084 case IFT_ARCNET: 1085 case IFT_ETHER: 1086 case IFT_FDDI: 1087 case IFT_IEEE1394: 1088 case IFT_L2VLAN: 1089 case IFT_IEEE80211: 1090 case IFT_INFINIBAND: 1091 case IFT_BRIDGE: 1092 case IFT_ISO88025: 1093 return IF_LLADDR(ifp); 1094 default: 1095 return NULL; 1096 } 1097 } 1098 1099 struct dadq { 1100 TAILQ_ENTRY(dadq) dad_list; 1101 struct ifaddr *dad_ifa; 1102 int dad_count; /* max NS to send */ 1103 int dad_ns_tcount; /* # of trials to send NS */ 1104 int dad_ns_ocount; /* NS sent so far */ 1105 int dad_ns_icount; 1106 int dad_na_icount; 1107 int dad_ns_lcount; /* looped back NS */ 1108 int dad_loopbackprobe; /* probing state for loopback detection */ 1109 struct callout dad_timer_ch; 1110 struct vnet *dad_vnet; 1111 u_int dad_refcnt; 1112 #define ND_OPT_NONCE_LEN32 \ 1113 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1114 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1115 }; 1116 1117 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq); 1118 static VNET_DEFINE(struct rwlock, dad_rwlock); 1119 #define V_dadq VNET(dadq) 1120 #define V_dad_rwlock VNET(dad_rwlock) 1121 1122 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1123 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1124 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1125 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1126 1127 static void 1128 nd6_dad_add(struct dadq *dp) 1129 { 1130 1131 DADQ_WLOCK(); 1132 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1133 DADQ_WUNLOCK(); 1134 } 1135 1136 static void 1137 nd6_dad_del(struct dadq *dp) 1138 { 1139 1140 DADQ_WLOCK(); 1141 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1142 DADQ_WUNLOCK(); 1143 nd6_dad_rele(dp); 1144 } 1145 1146 static struct dadq * 1147 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1148 { 1149 struct dadq *dp; 1150 1151 DADQ_RLOCK(); 1152 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1153 if (dp->dad_ifa != ifa) 1154 continue; 1155 /* 1156 * Skip if the nonce matches the received one. 1157 * +2 in the length is required because of type and 1158 * length fields are included in a header. 1159 */ 1160 if (n != NULL && 1161 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1162 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1163 ND_OPT_NONCE_LEN) == 0) { 1164 dp->dad_ns_lcount++; 1165 continue; 1166 } 1167 refcount_acquire(&dp->dad_refcnt); 1168 break; 1169 } 1170 DADQ_RUNLOCK(); 1171 1172 return (dp); 1173 } 1174 1175 static void 1176 nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns) 1177 { 1178 1179 if (send_ns != 0) 1180 nd6_dad_ns_output(dp); 1181 callout_reset(&dp->dad_timer_ch, ticks, 1182 (void (*)(void *))nd6_dad_timer, (void *)dp); 1183 } 1184 1185 static void 1186 nd6_dad_stoptimer(struct dadq *dp) 1187 { 1188 1189 callout_drain(&dp->dad_timer_ch); 1190 } 1191 1192 static void 1193 nd6_dad_rele(struct dadq *dp) 1194 { 1195 1196 if (refcount_release(&dp->dad_refcnt)) { 1197 ifa_free(dp->dad_ifa); 1198 free(dp, M_IP6NDP); 1199 } 1200 } 1201 1202 void 1203 nd6_dad_init(void) 1204 { 1205 1206 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1207 TAILQ_INIT(&V_dadq); 1208 } 1209 1210 /* 1211 * Start Duplicate Address Detection (DAD) for specified interface address. 1212 */ 1213 void 1214 nd6_dad_start(struct ifaddr *ifa, int delay) 1215 { 1216 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1217 struct dadq *dp; 1218 char ip6buf[INET6_ADDRSTRLEN]; 1219 1220 /* 1221 * If we don't need DAD, don't do it. 1222 * There are several cases: 1223 * - DAD is disabled (ip6_dad_count == 0) 1224 * - the interface address is anycast 1225 */ 1226 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1227 log(LOG_DEBUG, 1228 "nd6_dad_start: called with non-tentative address " 1229 "%s(%s)\n", 1230 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1231 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1232 return; 1233 } 1234 if (ia->ia6_flags & IN6_IFF_ANYCAST) { 1235 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1236 return; 1237 } 1238 if (!V_ip6_dad_count) { 1239 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1240 return; 1241 } 1242 if (ifa->ifa_ifp == NULL) 1243 panic("nd6_dad_start: ifa->ifa_ifp == NULL"); 1244 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) { 1245 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1246 return; 1247 } 1248 if (!(ifa->ifa_ifp->if_flags & IFF_UP) || 1249 !(ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) || 1250 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED)) { 1251 ia->ia6_flags |= IN6_IFF_TENTATIVE; 1252 return; 1253 } 1254 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1255 /* 1256 * DAD is already in progress. Let the existing entry 1257 * finish it. 1258 */ 1259 nd6_dad_rele(dp); 1260 return; 1261 } 1262 1263 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1264 if (dp == NULL) { 1265 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1266 "%s(%s)\n", 1267 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1268 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1269 return; 1270 } 1271 callout_init(&dp->dad_timer_ch, 0); 1272 #ifdef VIMAGE 1273 dp->dad_vnet = curvnet; 1274 #endif 1275 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1276 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1277 1278 /* 1279 * Send NS packet for DAD, ip6_dad_count times. 1280 * Note that we must delay the first transmission, if this is the 1281 * first packet to be sent from the interface after interface 1282 * (re)initialization. 1283 */ 1284 dp->dad_ifa = ifa; 1285 ifa_ref(dp->dad_ifa); 1286 dp->dad_count = V_ip6_dad_count; 1287 dp->dad_ns_icount = dp->dad_na_icount = 0; 1288 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1289 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1290 refcount_init(&dp->dad_refcnt, 1); 1291 nd6_dad_add(dp); 1292 nd6_dad_starttimer(dp, delay, 0); 1293 } 1294 1295 /* 1296 * terminate DAD unconditionally. used for address removals. 1297 */ 1298 void 1299 nd6_dad_stop(struct ifaddr *ifa) 1300 { 1301 struct dadq *dp; 1302 1303 dp = nd6_dad_find(ifa, NULL); 1304 if (!dp) { 1305 /* DAD wasn't started yet */ 1306 return; 1307 } 1308 1309 nd6_dad_stoptimer(dp); 1310 1311 /* 1312 * The DAD queue entry may have been removed by nd6_dad_timer() while 1313 * we were waiting for it to stop, so re-do the lookup. 1314 */ 1315 nd6_dad_rele(dp); 1316 if (nd6_dad_find(ifa, NULL) == NULL) 1317 return; 1318 1319 nd6_dad_del(dp); 1320 nd6_dad_rele(dp); 1321 } 1322 1323 static void 1324 nd6_dad_timer(struct dadq *dp) 1325 { 1326 CURVNET_SET(dp->dad_vnet); 1327 struct ifaddr *ifa = dp->dad_ifa; 1328 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1329 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1330 char ip6buf[INET6_ADDRSTRLEN]; 1331 1332 /* Sanity check */ 1333 if (ia == NULL) { 1334 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n"); 1335 goto err; 1336 } 1337 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1338 /* Do not need DAD for ifdisabled interface. */ 1339 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1340 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1341 goto err; 1342 } 1343 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1344 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1345 "%s(%s)\n", 1346 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1347 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1348 goto err; 1349 } 1350 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1351 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1352 "%s(%s)\n", 1353 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1354 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1355 goto err; 1356 } 1357 1358 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1359 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1360 (((ifp->if_flags & IFF_UP) == 0) || 1361 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1362 nd6log((LOG_INFO, "%s: could not run DAD " 1363 "because the interface was down or not running.\n", 1364 if_name(ifa->ifa_ifp))); 1365 goto err; 1366 } 1367 1368 /* Need more checks? */ 1369 if (dp->dad_ns_ocount < dp->dad_count) { 1370 /* 1371 * We have more NS to go. Send NS packet for DAD. 1372 */ 1373 nd6_dad_starttimer(dp, 1374 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1); 1375 goto done; 1376 } else { 1377 /* 1378 * We have transmitted sufficient number of DAD packets. 1379 * See what we've got. 1380 */ 1381 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1382 /* We've seen NS or NA, means DAD has failed. */ 1383 nd6_dad_duplicated(ifa, dp); 1384 else if (V_dad_enhanced != 0 && 1385 dp->dad_ns_lcount > 0 && 1386 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1387 /* 1388 * Sec. 4.1 in RFC 7527 requires transmission of 1389 * additional probes until the loopback condition 1390 * becomes clear when a looped back probe is detected. 1391 */ 1392 log(LOG_ERR, "%s: a looped back NS message is " 1393 "detected during DAD for %s. " 1394 "Another DAD probes are being sent.\n", 1395 if_name(ifa->ifa_ifp), 1396 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1397 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1398 /* 1399 * Send an NS immediately and increase dad_count by 1400 * V_nd6_mmaxtries - 1. 1401 */ 1402 dp->dad_count = 1403 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1404 nd6_dad_starttimer(dp, 1405 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1406 1); 1407 goto done; 1408 } else { 1409 /* 1410 * We are done with DAD. No NA came, no NS came. 1411 * No duplicate address found. Check IFDISABLED flag 1412 * again in case that it is changed between the 1413 * beginning of this function and here. 1414 */ 1415 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1416 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1417 1418 nd6log((LOG_DEBUG, 1419 "%s: DAD complete for %s - no duplicates found\n", 1420 if_name(ifa->ifa_ifp), 1421 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1422 if (dp->dad_ns_lcount > 0) 1423 log(LOG_ERR, "%s: DAD completed while " 1424 "a looped back NS message is detected " 1425 "during DAD for %s.\n", 1426 if_name(ifa->ifa_ifp), 1427 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1428 } 1429 } 1430 err: 1431 nd6_dad_del(dp); 1432 done: 1433 CURVNET_RESTORE(); 1434 } 1435 1436 static void 1437 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1438 { 1439 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1440 struct ifnet *ifp; 1441 char ip6buf[INET6_ADDRSTRLEN]; 1442 1443 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1444 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1445 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1446 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1447 dp->dad_na_icount); 1448 1449 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1450 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1451 1452 ifp = ifa->ifa_ifp; 1453 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1454 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1455 log(LOG_ERR, "%s: manual intervention required\n", 1456 if_name(ifp)); 1457 1458 /* 1459 * If the address is a link-local address formed from an interface 1460 * identifier based on the hardware address which is supposed to be 1461 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1462 * operation on the interface SHOULD be disabled. 1463 * [RFC 4862, Section 5.4.5] 1464 */ 1465 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1466 struct in6_addr in6; 1467 1468 /* 1469 * To avoid over-reaction, we only apply this logic when we are 1470 * very sure that hardware addresses are supposed to be unique. 1471 */ 1472 switch (ifp->if_type) { 1473 case IFT_ETHER: 1474 case IFT_FDDI: 1475 case IFT_ATM: 1476 case IFT_IEEE1394: 1477 case IFT_IEEE80211: 1478 case IFT_INFINIBAND: 1479 in6 = ia->ia_addr.sin6_addr; 1480 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1481 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1482 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1483 log(LOG_ERR, "%s: possible hardware address " 1484 "duplication detected, disable IPv6\n", 1485 if_name(ifp)); 1486 } 1487 break; 1488 } 1489 } 1490 } 1491 1492 static void 1493 nd6_dad_ns_output(struct dadq *dp) 1494 { 1495 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1496 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1497 int i; 1498 1499 dp->dad_ns_tcount++; 1500 if ((ifp->if_flags & IFF_UP) == 0) { 1501 return; 1502 } 1503 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1504 return; 1505 } 1506 1507 dp->dad_ns_ocount++; 1508 if (V_dad_enhanced != 0) { 1509 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1510 dp->dad_nonce[i] = arc4random(); 1511 /* 1512 * XXXHRS: Note that in the case that 1513 * DupAddrDetectTransmits > 1, multiple NS messages with 1514 * different nonces can be looped back in an unexpected 1515 * order. The current implementation recognizes only 1516 * the latest nonce on the sender side. Practically it 1517 * should work well in almost all cases. 1518 */ 1519 } 1520 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1521 (uint8_t *)&dp->dad_nonce[0]); 1522 } 1523 1524 static void 1525 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1526 { 1527 struct in6_ifaddr *ia; 1528 struct ifnet *ifp; 1529 const struct in6_addr *taddr6; 1530 struct dadq *dp; 1531 1532 if (ifa == NULL) 1533 panic("ifa == NULL in nd6_dad_ns_input"); 1534 1535 ia = (struct in6_ifaddr *)ifa; 1536 ifp = ifa->ifa_ifp; 1537 taddr6 = &ia->ia_addr.sin6_addr; 1538 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1539 if (V_dad_enhanced == 0) 1540 ndopt_nonce = NULL; 1541 dp = nd6_dad_find(ifa, ndopt_nonce); 1542 if (dp == NULL) 1543 return; 1544 1545 dp->dad_ns_icount++; 1546 nd6_dad_rele(dp); 1547 } 1548 1549 static void 1550 nd6_dad_na_input(struct ifaddr *ifa) 1551 { 1552 struct dadq *dp; 1553 1554 if (ifa == NULL) 1555 panic("ifa == NULL in nd6_dad_na_input"); 1556 1557 dp = nd6_dad_find(ifa, NULL); 1558 if (dp != NULL) { 1559 dp->dad_na_icount++; 1560 nd6_dad_rele(dp); 1561 } 1562 } 1563