1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $ 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 #include "opt_ipsec.h" 40 #include "opt_mpath.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/malloc.h> 45 #include <sys/libkern.h> 46 #include <sys/lock.h> 47 #include <sys/rwlock.h> 48 #include <sys/mbuf.h> 49 #include <sys/socket.h> 50 #include <sys/sockio.h> 51 #include <sys/time.h> 52 #include <sys/kernel.h> 53 #include <sys/errno.h> 54 #include <sys/sysctl.h> 55 #include <sys/syslog.h> 56 #include <sys/queue.h> 57 #include <sys/callout.h> 58 #include <sys/refcount.h> 59 60 #include <net/if.h> 61 #include <net/if_types.h> 62 #include <net/if_dl.h> 63 #include <net/if_var.h> 64 #include <net/route.h> 65 #ifdef RADIX_MPATH 66 #include <net/radix_mpath.h> 67 #endif 68 #include <net/vnet.h> 69 70 #include <netinet/in.h> 71 #include <netinet/in_var.h> 72 #include <net/if_llatbl.h> 73 #include <netinet6/in6_var.h> 74 #include <netinet6/in6_ifattach.h> 75 #include <netinet/ip6.h> 76 #include <netinet6/ip6_var.h> 77 #include <netinet6/scope6_var.h> 78 #include <netinet6/nd6.h> 79 #include <netinet/icmp6.h> 80 #include <netinet/ip_carp.h> 81 #include <netinet6/send.h> 82 83 #define SDL(s) ((struct sockaddr_dl *)s) 84 85 struct dadq; 86 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *); 87 static void nd6_dad_add(struct dadq *dp); 88 static void nd6_dad_del(struct dadq *dp); 89 static void nd6_dad_rele(struct dadq *); 90 static void nd6_dad_starttimer(struct dadq *, int, int); 91 static void nd6_dad_stoptimer(struct dadq *); 92 static void nd6_dad_timer(struct dadq *); 93 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *); 94 static void nd6_dad_ns_output(struct dadq *); 95 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *); 96 static void nd6_dad_na_input(struct ifaddr *); 97 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 98 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 99 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *, 100 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int); 101 102 VNET_DEFINE_STATIC(int, dad_enhanced) = 1; 103 #define V_dad_enhanced VNET(dad_enhanced) 104 105 SYSCTL_DECL(_net_inet6_ip6); 106 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW, 107 &VNET_NAME(dad_enhanced), 0, 108 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD."); 109 110 VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to 111 transmit DAD packet */ 112 #define V_dad_maxtry VNET(dad_maxtry) 113 114 /* 115 * Input a Neighbor Solicitation Message. 116 * 117 * Based on RFC 2461 118 * Based on RFC 2462 (duplicate address detection) 119 */ 120 void 121 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 122 { 123 struct ifnet *ifp = m->m_pkthdr.rcvif; 124 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 125 struct nd_neighbor_solicit *nd_ns; 126 struct in6_addr saddr6 = ip6->ip6_src; 127 struct in6_addr daddr6 = ip6->ip6_dst; 128 struct in6_addr taddr6; 129 struct in6_addr myaddr6; 130 char *lladdr = NULL; 131 struct ifaddr *ifa = NULL; 132 int lladdrlen = 0; 133 int anycast = 0, proxy = 0, tentative = 0; 134 int tlladdr; 135 int rflag; 136 union nd_opts ndopts; 137 struct sockaddr_dl proxydl; 138 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 139 140 /* RFC 6980: Nodes MUST silently ignore fragments */ 141 if(m->m_flags & M_FRAGMENTED) 142 goto freeit; 143 144 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 145 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 146 rflag = 0; 147 #ifndef PULLDOWN_TEST 148 IP6_EXTHDR_CHECK(m, off, icmp6len,); 149 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 150 #else 151 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); 152 if (nd_ns == NULL) { 153 ICMP6STAT_INC(icp6s_tooshort); 154 return; 155 } 156 #endif 157 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ 158 taddr6 = nd_ns->nd_ns_target; 159 if (in6_setscope(&taddr6, ifp, NULL) != 0) 160 goto bad; 161 162 if (ip6->ip6_hlim != 255) { 163 nd6log((LOG_ERR, 164 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 165 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 166 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 167 goto bad; 168 } 169 170 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 171 /* dst has to be a solicited node multicast address. */ 172 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 173 /* don't check ifindex portion */ 174 daddr6.s6_addr32[1] == 0 && 175 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 176 daddr6.s6_addr8[12] == 0xff) { 177 ; /* good */ 178 } else { 179 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 180 "(wrong ip6 dst)\n")); 181 goto bad; 182 } 183 } else if (!V_nd6_onlink_ns_rfc4861) { 184 struct sockaddr_in6 src_sa6; 185 186 /* 187 * According to recent IETF discussions, it is not a good idea 188 * to accept a NS from an address which would not be deemed 189 * to be a neighbor otherwise. This point is expected to be 190 * clarified in future revisions of the specification. 191 */ 192 bzero(&src_sa6, sizeof(src_sa6)); 193 src_sa6.sin6_family = AF_INET6; 194 src_sa6.sin6_len = sizeof(src_sa6); 195 src_sa6.sin6_addr = saddr6; 196 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 197 nd6log((LOG_INFO, "nd6_ns_input: " 198 "NS packet from non-neighbor\n")); 199 goto bad; 200 } 201 } 202 203 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 204 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 205 goto bad; 206 } 207 208 icmp6len -= sizeof(*nd_ns); 209 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 210 if (nd6_options(&ndopts) < 0) { 211 nd6log((LOG_INFO, 212 "nd6_ns_input: invalid ND option, ignored\n")); 213 /* nd6_options have incremented stats */ 214 goto freeit; 215 } 216 217 if (ndopts.nd_opts_src_lladdr) { 218 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 219 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 220 } 221 222 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 223 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 224 "(link-layer address option)\n")); 225 goto bad; 226 } 227 228 /* 229 * Attaching target link-layer address to the NA? 230 * (RFC 2461 7.2.4) 231 * 232 * NS IP dst is unicast/anycast MUST NOT add 233 * NS IP dst is solicited-node multicast MUST add 234 * 235 * In implementation, we add target link-layer address by default. 236 * We do not add one in MUST NOT cases. 237 */ 238 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 239 tlladdr = 0; 240 else 241 tlladdr = 1; 242 243 /* 244 * Target address (taddr6) must be either: 245 * (1) Valid unicast/anycast address for my receiving interface, 246 * (2) Unicast address for which I'm offering proxy service, or 247 * (3) "tentative" address on which DAD is being performed. 248 */ 249 /* (1) and (3) check. */ 250 if (ifp->if_carp) 251 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 252 else 253 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 254 255 /* (2) check. */ 256 if (ifa == NULL) { 257 struct sockaddr_dl rt_gateway; 258 struct rt_addrinfo info; 259 struct sockaddr_in6 dst6; 260 261 bzero(&dst6, sizeof(dst6)); 262 dst6.sin6_len = sizeof(struct sockaddr_in6); 263 dst6.sin6_family = AF_INET6; 264 dst6.sin6_addr = taddr6; 265 266 bzero(&rt_gateway, sizeof(rt_gateway)); 267 rt_gateway.sdl_len = sizeof(rt_gateway); 268 bzero(&info, sizeof(info)); 269 info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway; 270 271 if (rib_lookup_info(ifp->if_fib, (struct sockaddr *)&dst6, 272 0, 0, &info) == 0) { 273 if ((info.rti_flags & RTF_ANNOUNCE) != 0 && 274 rt_gateway.sdl_family == AF_LINK) { 275 276 /* 277 * proxy NDP for single entry 278 */ 279 proxydl = *SDL(&rt_gateway); 280 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal( 281 ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 282 if (ifa) 283 proxy = 1; 284 } 285 } 286 } 287 if (ifa == NULL) { 288 /* 289 * We've got an NS packet, and we don't have that adddress 290 * assigned for us. We MUST silently ignore it. 291 * See RFC2461 7.2.3. 292 */ 293 goto freeit; 294 } 295 myaddr6 = *IFA_IN6(ifa); 296 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 297 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 298 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 299 goto freeit; 300 301 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 302 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 303 "(if %d, NS packet %d)\n", 304 ip6_sprintf(ip6bufs, &taddr6), 305 ifp->if_addrlen, lladdrlen - 2)); 306 goto bad; 307 } 308 309 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 310 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 311 ip6_sprintf(ip6bufs, &saddr6))); 312 goto freeit; 313 } 314 315 /* 316 * We have neighbor solicitation packet, with target address equals to 317 * one of my tentative address. 318 * 319 * src addr how to process? 320 * --- --- 321 * multicast of course, invalid (rejected in ip6_input) 322 * unicast somebody is doing address resolution -> ignore 323 * unspec dup address detection 324 * 325 * The processing is defined in RFC 2462. 326 */ 327 if (tentative) { 328 /* 329 * If source address is unspecified address, it is for 330 * duplicate address detection. 331 * 332 * If not, the packet is for addess resolution; 333 * silently ignore it. 334 */ 335 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 336 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 337 338 goto freeit; 339 } 340 341 /* 342 * If the source address is unspecified address, entries must not 343 * be created or updated. 344 * It looks that sender is performing DAD. Output NA toward 345 * all-node multicast address, to tell the sender that I'm using 346 * the address. 347 * S bit ("solicited") must be zero. 348 */ 349 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 350 struct in6_addr in6_all; 351 352 in6_all = in6addr_linklocal_allnodes; 353 if (in6_setscope(&in6_all, ifp, NULL) != 0) 354 goto bad; 355 nd6_na_output_fib(ifp, &in6_all, &taddr6, 356 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 357 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 358 M_GETFIB(m)); 359 goto freeit; 360 } 361 362 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 363 ND_NEIGHBOR_SOLICIT, 0); 364 365 nd6_na_output_fib(ifp, &saddr6, &taddr6, 366 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 367 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 368 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 369 freeit: 370 if (ifa != NULL) 371 ifa_free(ifa); 372 m_freem(m); 373 return; 374 375 bad: 376 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 377 ip6_sprintf(ip6bufs, &saddr6))); 378 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 379 ip6_sprintf(ip6bufs, &daddr6))); 380 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 381 ip6_sprintf(ip6bufs, &taddr6))); 382 ICMP6STAT_INC(icp6s_badns); 383 if (ifa != NULL) 384 ifa_free(ifa); 385 m_freem(m); 386 } 387 388 /* 389 * Output a Neighbor Solicitation Message. Caller specifies: 390 * - ICMP6 header source IP6 address 391 * - ND6 header target IP6 address 392 * - ND6 header source datalink address 393 * 394 * Based on RFC 2461 395 * Based on RFC 2462 (duplicate address detection) 396 * 397 * ln - for source address determination 398 * nonce - If non-NULL, NS is used for duplicate address detection and 399 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 400 */ 401 static void 402 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 403 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 404 uint8_t *nonce, u_int fibnum) 405 { 406 struct mbuf *m; 407 struct m_tag *mtag; 408 struct ip6_hdr *ip6; 409 struct nd_neighbor_solicit *nd_ns; 410 struct ip6_moptions im6o; 411 int icmp6len; 412 int maxlen; 413 caddr_t mac; 414 415 if (IN6_IS_ADDR_MULTICAST(taddr6)) 416 return; 417 418 /* estimate the size of message */ 419 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 420 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 421 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 422 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 423 __func__, max_linkhdr, maxlen, MCLBYTES)); 424 425 if (max_linkhdr + maxlen > MHLEN) 426 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 427 else 428 m = m_gethdr(M_NOWAIT, MT_DATA); 429 if (m == NULL) 430 return; 431 M_SETFIB(m, fibnum); 432 433 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 434 m->m_flags |= M_MCAST; 435 im6o.im6o_multicast_ifp = ifp; 436 im6o.im6o_multicast_hlim = 255; 437 im6o.im6o_multicast_loop = 0; 438 } 439 440 icmp6len = sizeof(*nd_ns); 441 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 442 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 443 444 /* fill neighbor solicitation packet */ 445 ip6 = mtod(m, struct ip6_hdr *); 446 ip6->ip6_flow = 0; 447 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 448 ip6->ip6_vfc |= IPV6_VERSION; 449 /* ip6->ip6_plen will be set later */ 450 ip6->ip6_nxt = IPPROTO_ICMPV6; 451 ip6->ip6_hlim = 255; 452 if (daddr6) 453 ip6->ip6_dst = *daddr6; 454 else { 455 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 456 ip6->ip6_dst.s6_addr16[1] = 0; 457 ip6->ip6_dst.s6_addr32[1] = 0; 458 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 459 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 460 ip6->ip6_dst.s6_addr8[12] = 0xff; 461 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 462 goto bad; 463 } 464 if (nonce == NULL) { 465 struct ifaddr *ifa = NULL; 466 467 /* 468 * RFC2461 7.2.2: 469 * "If the source address of the packet prompting the 470 * solicitation is the same as one of the addresses assigned 471 * to the outgoing interface, that address SHOULD be placed 472 * in the IP Source Address of the outgoing solicitation. 473 * Otherwise, any one of the addresses assigned to the 474 * interface should be used." 475 * 476 * We use the source address for the prompting packet 477 * (saddr6), if saddr6 belongs to the outgoing interface. 478 * Otherwise, we perform the source address selection as usual. 479 */ 480 481 if (saddr6 != NULL) 482 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 483 if (ifa != NULL) { 484 /* ip6_src set already. */ 485 ip6->ip6_src = *saddr6; 486 ifa_free(ifa); 487 } else { 488 int error; 489 struct in6_addr dst6, src6; 490 uint32_t scopeid; 491 492 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); 493 error = in6_selectsrc_addr(fibnum, &dst6, 494 scopeid, ifp, &src6, NULL); 495 if (error) { 496 char ip6buf[INET6_ADDRSTRLEN]; 497 nd6log((LOG_DEBUG, "%s: source can't be " 498 "determined: dst=%s, error=%d\n", __func__, 499 ip6_sprintf(ip6buf, &dst6), 500 error)); 501 goto bad; 502 } 503 ip6->ip6_src = src6; 504 } 505 } else { 506 /* 507 * Source address for DAD packet must always be IPv6 508 * unspecified address. (0::0) 509 * We actually don't have to 0-clear the address (we did it 510 * above), but we do so here explicitly to make the intention 511 * clearer. 512 */ 513 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 514 } 515 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 516 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 517 nd_ns->nd_ns_code = 0; 518 nd_ns->nd_ns_reserved = 0; 519 nd_ns->nd_ns_target = *taddr6; 520 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 521 522 /* 523 * Add source link-layer address option. 524 * 525 * spec implementation 526 * --- --- 527 * DAD packet MUST NOT do not add the option 528 * there's no link layer address: 529 * impossible do not add the option 530 * there's link layer address: 531 * Multicast NS MUST add one add the option 532 * Unicast NS SHOULD add one add the option 533 */ 534 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 535 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 536 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 537 /* 8 byte alignments... */ 538 optlen = (optlen + 7) & ~7; 539 540 m->m_pkthdr.len += optlen; 541 m->m_len += optlen; 542 icmp6len += optlen; 543 bzero((caddr_t)nd_opt, optlen); 544 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 545 nd_opt->nd_opt_len = optlen >> 3; 546 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 547 } 548 /* 549 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 550 * This behavior is documented as Enhanced Duplicate Address 551 * Detection in RFC 7527. 552 * net.inet6.ip6.dad_enhanced=0 disables this. 553 */ 554 if (V_dad_enhanced != 0 && nonce != NULL) { 555 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 556 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 557 /* 8-byte alignment is required. */ 558 optlen = (optlen + 7) & ~7; 559 560 m->m_pkthdr.len += optlen; 561 m->m_len += optlen; 562 icmp6len += optlen; 563 bzero((caddr_t)nd_opt, optlen); 564 nd_opt->nd_opt_type = ND_OPT_NONCE; 565 nd_opt->nd_opt_len = optlen >> 3; 566 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 567 } 568 ip6->ip6_plen = htons((u_short)icmp6len); 569 nd_ns->nd_ns_cksum = 0; 570 nd_ns->nd_ns_cksum = 571 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 572 573 if (send_sendso_input_hook != NULL) { 574 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 575 sizeof(unsigned short), M_NOWAIT); 576 if (mtag == NULL) 577 goto bad; 578 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 579 m_tag_prepend(m, mtag); 580 } 581 582 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 583 &im6o, NULL, NULL); 584 icmp6_ifstat_inc(ifp, ifs6_out_msg); 585 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 586 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 587 588 return; 589 590 bad: 591 m_freem(m); 592 } 593 594 #ifndef BURN_BRIDGES 595 void 596 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 597 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 598 { 599 600 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 601 } 602 #endif 603 /* 604 * Neighbor advertisement input handling. 605 * 606 * Based on RFC 2461 607 * Based on RFC 2462 (duplicate address detection) 608 * 609 * the following items are not implemented yet: 610 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 611 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 612 */ 613 void 614 nd6_na_input(struct mbuf *m, int off, int icmp6len) 615 { 616 struct epoch_tracker et; 617 struct ifnet *ifp = m->m_pkthdr.rcvif; 618 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 619 struct nd_neighbor_advert *nd_na; 620 struct in6_addr daddr6 = ip6->ip6_dst; 621 struct in6_addr taddr6; 622 int flags; 623 int is_router; 624 int is_solicited; 625 int is_override; 626 char *lladdr = NULL; 627 int lladdrlen = 0; 628 int checklink = 0; 629 struct ifaddr *ifa; 630 struct llentry *ln = NULL; 631 union nd_opts ndopts; 632 struct mbuf *chain = NULL; 633 struct sockaddr_in6 sin6; 634 u_char linkhdr[LLE_MAX_LINKHDR]; 635 size_t linkhdrsize; 636 int lladdr_off; 637 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 638 639 /* RFC 6980: Nodes MUST silently ignore fragments */ 640 if(m->m_flags & M_FRAGMENTED) 641 goto freeit; 642 643 if (ip6->ip6_hlim != 255) { 644 nd6log((LOG_ERR, 645 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 646 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 647 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 648 goto bad; 649 } 650 651 #ifndef PULLDOWN_TEST 652 IP6_EXTHDR_CHECK(m, off, icmp6len,); 653 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 654 #else 655 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 656 if (nd_na == NULL) { 657 ICMP6STAT_INC(icp6s_tooshort); 658 return; 659 } 660 #endif 661 662 flags = nd_na->nd_na_flags_reserved; 663 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 664 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 665 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 666 memset(&sin6, 0, sizeof(sin6)); 667 668 taddr6 = nd_na->nd_na_target; 669 if (in6_setscope(&taddr6, ifp, NULL)) 670 goto bad; /* XXX: impossible */ 671 672 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 673 nd6log((LOG_ERR, 674 "nd6_na_input: invalid target address %s\n", 675 ip6_sprintf(ip6bufs, &taddr6))); 676 goto bad; 677 } 678 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 679 if (is_solicited) { 680 nd6log((LOG_ERR, 681 "nd6_na_input: a solicited adv is multicasted\n")); 682 goto bad; 683 } 684 685 icmp6len -= sizeof(*nd_na); 686 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 687 if (nd6_options(&ndopts) < 0) { 688 nd6log((LOG_INFO, 689 "nd6_na_input: invalid ND option, ignored\n")); 690 /* nd6_options have incremented stats */ 691 goto freeit; 692 } 693 694 if (ndopts.nd_opts_tgt_lladdr) { 695 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 696 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 697 } 698 699 /* 700 * This effectively disables the DAD check on a non-master CARP 701 * address. 702 */ 703 if (ifp->if_carp) 704 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 705 else 706 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 707 708 /* 709 * Target address matches one of my interface address. 710 * 711 * If my address is tentative, this means that there's somebody 712 * already using the same address as mine. This indicates DAD failure. 713 * This is defined in RFC 2462. 714 * 715 * Otherwise, process as defined in RFC 2461. 716 */ 717 if (ifa 718 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 719 nd6_dad_na_input(ifa); 720 ifa_free(ifa); 721 goto freeit; 722 } 723 724 /* Just for safety, maybe unnecessary. */ 725 if (ifa) { 726 ifa_free(ifa); 727 log(LOG_ERR, 728 "nd6_na_input: duplicate IP6 address %s\n", 729 ip6_sprintf(ip6bufs, &taddr6)); 730 goto freeit; 731 } 732 733 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 734 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 735 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 736 ifp->if_addrlen, lladdrlen - 2)); 737 goto bad; 738 } 739 740 /* 741 * If no neighbor cache entry is found, NA SHOULD silently be 742 * discarded. 743 */ 744 NET_EPOCH_ENTER(et); 745 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 746 NET_EPOCH_EXIT(et); 747 if (ln == NULL) { 748 goto freeit; 749 } 750 751 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 752 /* 753 * If the link-layer has address, and no lladdr option came, 754 * discard the packet. 755 */ 756 if (ifp->if_addrlen && lladdr == NULL) { 757 goto freeit; 758 } 759 760 /* 761 * Record link-layer address, and update the state. 762 */ 763 linkhdrsize = sizeof(linkhdr); 764 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 765 linkhdr, &linkhdrsize, &lladdr_off) != 0) 766 return; 767 768 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize, 769 lladdr_off) == 0) { 770 ln = NULL; 771 goto freeit; 772 } 773 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 774 if (is_solicited) 775 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 776 else 777 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 778 if ((ln->ln_router = is_router) != 0) { 779 /* 780 * This means a router's state has changed from 781 * non-reachable to probably reachable, and might 782 * affect the status of associated prefixes.. 783 */ 784 checklink = 1; 785 } 786 } else { 787 int llchange; 788 789 /* 790 * Check if the link-layer address has changed or not. 791 */ 792 if (lladdr == NULL) 793 llchange = 0; 794 else { 795 if (ln->la_flags & LLE_VALID) { 796 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 797 llchange = 1; 798 else 799 llchange = 0; 800 } else 801 llchange = 1; 802 } 803 804 /* 805 * This is VERY complex. Look at it with care. 806 * 807 * override solicit lladdr llchange action 808 * (L: record lladdr) 809 * 810 * 0 0 n -- (2c) 811 * 0 0 y n (2b) L 812 * 0 0 y y (1) REACHABLE->STALE 813 * 0 1 n -- (2c) *->REACHABLE 814 * 0 1 y n (2b) L *->REACHABLE 815 * 0 1 y y (1) REACHABLE->STALE 816 * 1 0 n -- (2a) 817 * 1 0 y n (2a) L 818 * 1 0 y y (2a) L *->STALE 819 * 1 1 n -- (2a) *->REACHABLE 820 * 1 1 y n (2a) L *->REACHABLE 821 * 1 1 y y (2a) L *->REACHABLE 822 */ 823 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 824 /* 825 * If state is REACHABLE, make it STALE. 826 * no other updates should be done. 827 */ 828 if (ln->ln_state == ND6_LLINFO_REACHABLE) 829 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 830 goto freeit; 831 } else if (is_override /* (2a) */ 832 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 833 || lladdr == NULL) { /* (2c) */ 834 /* 835 * Update link-local address, if any. 836 */ 837 if (lladdr != NULL) { 838 linkhdrsize = sizeof(linkhdr); 839 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 840 linkhdr, &linkhdrsize, &lladdr_off) != 0) 841 goto freeit; 842 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 843 linkhdrsize, lladdr_off) == 0) { 844 ln = NULL; 845 goto freeit; 846 } 847 EVENTHANDLER_INVOKE(lle_event, ln, 848 LLENTRY_RESOLVED); 849 } 850 851 /* 852 * If solicited, make the state REACHABLE. 853 * If not solicited and the link-layer address was 854 * changed, make it STALE. 855 */ 856 if (is_solicited) 857 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 858 else { 859 if (lladdr != NULL && llchange) 860 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 861 } 862 } 863 864 if (ln->ln_router && !is_router) { 865 /* 866 * The peer dropped the router flag. 867 * Remove the sender from the Default Router List and 868 * update the Destination Cache entries. 869 */ 870 struct ifnet *nd6_ifp; 871 872 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 873 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 874 (ND_IFINFO(nd6_ifp)->flags & 875 ND6_IFF_ACCEPT_RTADV) != 0) 876 /* 877 * Even if the neighbor is not in the default 878 * router list, the neighbor may be used as a 879 * next hop for some destinations (e.g. redirect 880 * case). So we must call rt6_flush explicitly. 881 */ 882 rt6_flush(&ip6->ip6_src, ifp); 883 } 884 ln->ln_router = is_router; 885 } 886 /* XXX - QL 887 * Does this matter? 888 * rt->rt_flags &= ~RTF_REJECT; 889 */ 890 ln->la_asked = 0; 891 if (ln->la_hold != NULL) 892 nd6_grab_holdchain(ln, &chain, &sin6); 893 freeit: 894 if (ln != NULL) 895 LLE_WUNLOCK(ln); 896 897 if (chain != NULL) 898 nd6_flush_holdchain(ifp, chain, &sin6); 899 900 if (checklink) 901 pfxlist_onlink_check(); 902 903 m_freem(m); 904 return; 905 906 bad: 907 if (ln != NULL) 908 LLE_WUNLOCK(ln); 909 910 ICMP6STAT_INC(icp6s_badna); 911 m_freem(m); 912 } 913 914 /* 915 * Neighbor advertisement output handling. 916 * 917 * Based on RFC 2461 918 * 919 * the following items are not implemented yet: 920 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 921 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 922 * 923 * tlladdr - 1 if include target link-layer address 924 * sdl0 - sockaddr_dl (= proxy NA) or NULL 925 */ 926 static void 927 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 928 const struct in6_addr *taddr6, u_long flags, int tlladdr, 929 struct sockaddr *sdl0, u_int fibnum) 930 { 931 struct mbuf *m; 932 struct m_tag *mtag; 933 struct ip6_hdr *ip6; 934 struct nd_neighbor_advert *nd_na; 935 struct ip6_moptions im6o; 936 struct in6_addr daddr6, dst6, src6; 937 uint32_t scopeid; 938 939 int icmp6len, maxlen, error; 940 caddr_t mac = NULL; 941 942 daddr6 = *daddr6_0; /* make a local copy for modification */ 943 944 /* estimate the size of message */ 945 maxlen = sizeof(*ip6) + sizeof(*nd_na); 946 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 947 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 948 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 949 __func__, max_linkhdr, maxlen, MCLBYTES)); 950 951 if (max_linkhdr + maxlen > MHLEN) 952 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 953 else 954 m = m_gethdr(M_NOWAIT, MT_DATA); 955 if (m == NULL) 956 return; 957 M_SETFIB(m, fibnum); 958 959 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 960 m->m_flags |= M_MCAST; 961 im6o.im6o_multicast_ifp = ifp; 962 im6o.im6o_multicast_hlim = 255; 963 im6o.im6o_multicast_loop = 0; 964 } 965 966 icmp6len = sizeof(*nd_na); 967 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 968 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 969 970 /* fill neighbor advertisement packet */ 971 ip6 = mtod(m, struct ip6_hdr *); 972 ip6->ip6_flow = 0; 973 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 974 ip6->ip6_vfc |= IPV6_VERSION; 975 ip6->ip6_nxt = IPPROTO_ICMPV6; 976 ip6->ip6_hlim = 255; 977 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 978 /* reply to DAD */ 979 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 980 daddr6.s6_addr16[1] = 0; 981 daddr6.s6_addr32[1] = 0; 982 daddr6.s6_addr32[2] = 0; 983 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 984 if (in6_setscope(&daddr6, ifp, NULL)) 985 goto bad; 986 987 flags &= ~ND_NA_FLAG_SOLICITED; 988 } 989 ip6->ip6_dst = daddr6; 990 991 /* 992 * Select a source whose scope is the same as that of the dest. 993 */ 994 in6_splitscope(&daddr6, &dst6, &scopeid); 995 error = in6_selectsrc_addr(fibnum, &dst6, 996 scopeid, ifp, &src6, NULL); 997 if (error) { 998 char ip6buf[INET6_ADDRSTRLEN]; 999 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1000 "determined: dst=%s, error=%d\n", 1001 ip6_sprintf(ip6buf, &daddr6), error)); 1002 goto bad; 1003 } 1004 ip6->ip6_src = src6; 1005 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1006 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1007 nd_na->nd_na_code = 0; 1008 nd_na->nd_na_target = *taddr6; 1009 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1010 1011 /* 1012 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1013 * see nd6_ns_input() for details. 1014 * Basically, if NS packet is sent to unicast/anycast addr, 1015 * target lladdr option SHOULD NOT be included. 1016 */ 1017 if (tlladdr) { 1018 /* 1019 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1020 * lladdr in sdl0. If we are not proxying (sending NA for 1021 * my address) use lladdr configured for the interface. 1022 */ 1023 if (sdl0 == NULL) { 1024 if (ifp->if_carp) 1025 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1026 if (mac == NULL) 1027 mac = nd6_ifptomac(ifp); 1028 } else if (sdl0->sa_family == AF_LINK) { 1029 struct sockaddr_dl *sdl; 1030 sdl = (struct sockaddr_dl *)sdl0; 1031 if (sdl->sdl_alen == ifp->if_addrlen) 1032 mac = LLADDR(sdl); 1033 } 1034 } 1035 if (tlladdr && mac) { 1036 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1037 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1038 1039 /* roundup to 8 bytes alignment! */ 1040 optlen = (optlen + 7) & ~7; 1041 1042 m->m_pkthdr.len += optlen; 1043 m->m_len += optlen; 1044 icmp6len += optlen; 1045 bzero((caddr_t)nd_opt, optlen); 1046 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1047 nd_opt->nd_opt_len = optlen >> 3; 1048 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1049 } else 1050 flags &= ~ND_NA_FLAG_OVERRIDE; 1051 1052 ip6->ip6_plen = htons((u_short)icmp6len); 1053 nd_na->nd_na_flags_reserved = flags; 1054 nd_na->nd_na_cksum = 0; 1055 nd_na->nd_na_cksum = 1056 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1057 1058 if (send_sendso_input_hook != NULL) { 1059 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1060 sizeof(unsigned short), M_NOWAIT); 1061 if (mtag == NULL) 1062 goto bad; 1063 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1064 m_tag_prepend(m, mtag); 1065 } 1066 1067 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1068 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1069 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1070 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1071 1072 return; 1073 1074 bad: 1075 m_freem(m); 1076 } 1077 1078 #ifndef BURN_BRIDGES 1079 void 1080 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1081 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1082 struct sockaddr *sdl0) 1083 { 1084 1085 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1086 RT_DEFAULT_FIB); 1087 } 1088 #endif 1089 1090 caddr_t 1091 nd6_ifptomac(struct ifnet *ifp) 1092 { 1093 switch (ifp->if_type) { 1094 case IFT_ETHER: 1095 case IFT_IEEE1394: 1096 case IFT_L2VLAN: 1097 case IFT_INFINIBAND: 1098 case IFT_BRIDGE: 1099 return IF_LLADDR(ifp); 1100 default: 1101 return NULL; 1102 } 1103 } 1104 1105 struct dadq { 1106 TAILQ_ENTRY(dadq) dad_list; 1107 struct ifaddr *dad_ifa; 1108 int dad_count; /* max NS to send */ 1109 int dad_ns_tcount; /* # of trials to send NS */ 1110 int dad_ns_ocount; /* NS sent so far */ 1111 int dad_ns_icount; 1112 int dad_na_icount; 1113 int dad_ns_lcount; /* looped back NS */ 1114 int dad_loopbackprobe; /* probing state for loopback detection */ 1115 struct callout dad_timer_ch; 1116 struct vnet *dad_vnet; 1117 u_int dad_refcnt; 1118 #define ND_OPT_NONCE_LEN32 \ 1119 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1120 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1121 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */ 1122 }; 1123 1124 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq); 1125 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock); 1126 #define V_dadq VNET(dadq) 1127 #define V_dad_rwlock VNET(dad_rwlock) 1128 1129 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1130 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1131 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1132 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1133 1134 static void 1135 nd6_dad_add(struct dadq *dp) 1136 { 1137 1138 DADQ_WLOCK(); 1139 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1140 dp->dad_ondadq = true; 1141 DADQ_WUNLOCK(); 1142 } 1143 1144 static void 1145 nd6_dad_del(struct dadq *dp) 1146 { 1147 1148 DADQ_WLOCK(); 1149 if (dp->dad_ondadq) { 1150 /* 1151 * Remove dp from the dadq and release the dadq's 1152 * reference. 1153 */ 1154 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1155 dp->dad_ondadq = false; 1156 DADQ_WUNLOCK(); 1157 nd6_dad_rele(dp); 1158 } else 1159 DADQ_WUNLOCK(); 1160 } 1161 1162 static struct dadq * 1163 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1164 { 1165 struct dadq *dp; 1166 1167 DADQ_RLOCK(); 1168 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1169 if (dp->dad_ifa != ifa) 1170 continue; 1171 /* 1172 * Skip if the nonce matches the received one. 1173 * +2 in the length is required because of type and 1174 * length fields are included in a header. 1175 */ 1176 if (n != NULL && 1177 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1178 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1179 ND_OPT_NONCE_LEN) == 0) { 1180 dp->dad_ns_lcount++; 1181 continue; 1182 } 1183 refcount_acquire(&dp->dad_refcnt); 1184 break; 1185 } 1186 DADQ_RUNLOCK(); 1187 1188 return (dp); 1189 } 1190 1191 static void 1192 nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns) 1193 { 1194 1195 if (send_ns != 0) 1196 nd6_dad_ns_output(dp); 1197 callout_reset(&dp->dad_timer_ch, ticks, 1198 (void (*)(void *))nd6_dad_timer, (void *)dp); 1199 } 1200 1201 static void 1202 nd6_dad_stoptimer(struct dadq *dp) 1203 { 1204 1205 callout_drain(&dp->dad_timer_ch); 1206 } 1207 1208 static void 1209 nd6_dad_rele(struct dadq *dp) 1210 { 1211 1212 if (refcount_release(&dp->dad_refcnt)) { 1213 ifa_free(dp->dad_ifa); 1214 free(dp, M_IP6NDP); 1215 } 1216 } 1217 1218 void 1219 nd6_dad_init(void) 1220 { 1221 1222 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1223 TAILQ_INIT(&V_dadq); 1224 } 1225 1226 /* 1227 * Start Duplicate Address Detection (DAD) for specified interface address. 1228 */ 1229 void 1230 nd6_dad_start(struct ifaddr *ifa, int delay) 1231 { 1232 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1233 struct dadq *dp; 1234 char ip6buf[INET6_ADDRSTRLEN]; 1235 1236 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0, 1237 ("starting DAD on non-tentative address %p", ifa)); 1238 1239 /* 1240 * If we don't need DAD, don't do it. 1241 * There are several cases: 1242 * - DAD is disabled globally or on the interface 1243 * - the interface address is anycast 1244 */ 1245 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 || 1246 V_ip6_dad_count == 0 || 1247 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) != 0) { 1248 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1249 return; 1250 } 1251 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 || 1252 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || 1253 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) != 0) 1254 return; 1255 1256 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1257 /* 1258 * DAD is already in progress. Let the existing entry 1259 * finish it. 1260 */ 1261 nd6_dad_rele(dp); 1262 return; 1263 } 1264 1265 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1266 if (dp == NULL) { 1267 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1268 "%s(%s)\n", 1269 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1270 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1271 return; 1272 } 1273 callout_init(&dp->dad_timer_ch, 0); 1274 #ifdef VIMAGE 1275 dp->dad_vnet = curvnet; 1276 #endif 1277 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1278 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1279 1280 /* 1281 * Send NS packet for DAD, ip6_dad_count times. 1282 * Note that we must delay the first transmission, if this is the 1283 * first packet to be sent from the interface after interface 1284 * (re)initialization. 1285 */ 1286 dp->dad_ifa = ifa; 1287 ifa_ref(dp->dad_ifa); 1288 dp->dad_count = V_ip6_dad_count; 1289 dp->dad_ns_icount = dp->dad_na_icount = 0; 1290 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1291 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1292 1293 /* Add this to the dadq and add a reference for the dadq. */ 1294 refcount_init(&dp->dad_refcnt, 1); 1295 nd6_dad_add(dp); 1296 nd6_dad_starttimer(dp, delay, 0); 1297 } 1298 1299 /* 1300 * terminate DAD unconditionally. used for address removals. 1301 */ 1302 void 1303 nd6_dad_stop(struct ifaddr *ifa) 1304 { 1305 struct dadq *dp; 1306 1307 dp = nd6_dad_find(ifa, NULL); 1308 if (!dp) { 1309 /* DAD wasn't started yet */ 1310 return; 1311 } 1312 1313 nd6_dad_stoptimer(dp); 1314 nd6_dad_del(dp); 1315 1316 /* Release this function's reference, acquired by nd6_dad_find(). */ 1317 nd6_dad_rele(dp); 1318 } 1319 1320 static void 1321 nd6_dad_timer(struct dadq *dp) 1322 { 1323 CURVNET_SET(dp->dad_vnet); 1324 struct ifaddr *ifa = dp->dad_ifa; 1325 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1326 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1327 char ip6buf[INET6_ADDRSTRLEN]; 1328 1329 KASSERT(ia != NULL, ("DAD entry %p with no address", dp)); 1330 1331 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1332 /* Do not need DAD for ifdisabled interface. */ 1333 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1334 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1335 goto err; 1336 } 1337 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1338 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1339 "%s(%s)\n", 1340 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1341 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1342 goto err; 1343 } 1344 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1345 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1346 "%s(%s)\n", 1347 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1348 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1349 goto err; 1350 } 1351 1352 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1353 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1354 (((ifp->if_flags & IFF_UP) == 0) || 1355 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1356 nd6log((LOG_INFO, "%s: could not run DAD " 1357 "because the interface was down or not running.\n", 1358 if_name(ifa->ifa_ifp))); 1359 goto err; 1360 } 1361 1362 /* Need more checks? */ 1363 if (dp->dad_ns_ocount < dp->dad_count) { 1364 /* 1365 * We have more NS to go. Send NS packet for DAD. 1366 */ 1367 nd6_dad_starttimer(dp, 1368 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1); 1369 goto done; 1370 } else { 1371 /* 1372 * We have transmitted sufficient number of DAD packets. 1373 * See what we've got. 1374 */ 1375 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1376 /* We've seen NS or NA, means DAD has failed. */ 1377 nd6_dad_duplicated(ifa, dp); 1378 else if (V_dad_enhanced != 0 && 1379 dp->dad_ns_lcount > 0 && 1380 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1381 /* 1382 * Sec. 4.1 in RFC 7527 requires transmission of 1383 * additional probes until the loopback condition 1384 * becomes clear when a looped back probe is detected. 1385 */ 1386 log(LOG_ERR, "%s: a looped back NS message is " 1387 "detected during DAD for %s. " 1388 "Another DAD probes are being sent.\n", 1389 if_name(ifa->ifa_ifp), 1390 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1391 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1392 /* 1393 * Send an NS immediately and increase dad_count by 1394 * V_nd6_mmaxtries - 1. 1395 */ 1396 dp->dad_count = 1397 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1398 nd6_dad_starttimer(dp, 1399 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1400 1); 1401 goto done; 1402 } else { 1403 /* 1404 * We are done with DAD. No NA came, no NS came. 1405 * No duplicate address found. Check IFDISABLED flag 1406 * again in case that it is changed between the 1407 * beginning of this function and here. 1408 */ 1409 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1410 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1411 1412 nd6log((LOG_DEBUG, 1413 "%s: DAD complete for %s - no duplicates found\n", 1414 if_name(ifa->ifa_ifp), 1415 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1416 if (dp->dad_ns_lcount > 0) 1417 log(LOG_ERR, "%s: DAD completed while " 1418 "a looped back NS message is detected " 1419 "during DAD for %s.\n", 1420 if_name(ifa->ifa_ifp), 1421 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1422 } 1423 } 1424 err: 1425 nd6_dad_del(dp); 1426 done: 1427 CURVNET_RESTORE(); 1428 } 1429 1430 static void 1431 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1432 { 1433 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1434 struct ifnet *ifp; 1435 char ip6buf[INET6_ADDRSTRLEN]; 1436 1437 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1438 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1439 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1440 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1441 dp->dad_na_icount); 1442 1443 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1444 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1445 1446 ifp = ifa->ifa_ifp; 1447 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1448 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1449 log(LOG_ERR, "%s: manual intervention required\n", 1450 if_name(ifp)); 1451 1452 /* 1453 * If the address is a link-local address formed from an interface 1454 * identifier based on the hardware address which is supposed to be 1455 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1456 * operation on the interface SHOULD be disabled. 1457 * [RFC 4862, Section 5.4.5] 1458 */ 1459 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1460 struct in6_addr in6; 1461 1462 /* 1463 * To avoid over-reaction, we only apply this logic when we are 1464 * very sure that hardware addresses are supposed to be unique. 1465 */ 1466 switch (ifp->if_type) { 1467 case IFT_ETHER: 1468 case IFT_ATM: 1469 case IFT_IEEE1394: 1470 case IFT_INFINIBAND: 1471 in6 = ia->ia_addr.sin6_addr; 1472 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1473 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1474 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1475 log(LOG_ERR, "%s: possible hardware address " 1476 "duplication detected, disable IPv6\n", 1477 if_name(ifp)); 1478 } 1479 break; 1480 } 1481 } 1482 } 1483 1484 static void 1485 nd6_dad_ns_output(struct dadq *dp) 1486 { 1487 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1488 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1489 int i; 1490 1491 dp->dad_ns_tcount++; 1492 if ((ifp->if_flags & IFF_UP) == 0) { 1493 return; 1494 } 1495 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1496 return; 1497 } 1498 1499 dp->dad_ns_ocount++; 1500 if (V_dad_enhanced != 0) { 1501 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1502 dp->dad_nonce[i] = arc4random(); 1503 /* 1504 * XXXHRS: Note that in the case that 1505 * DupAddrDetectTransmits > 1, multiple NS messages with 1506 * different nonces can be looped back in an unexpected 1507 * order. The current implementation recognizes only 1508 * the latest nonce on the sender side. Practically it 1509 * should work well in almost all cases. 1510 */ 1511 } 1512 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1513 (uint8_t *)&dp->dad_nonce[0]); 1514 } 1515 1516 static void 1517 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1518 { 1519 struct dadq *dp; 1520 1521 if (ifa == NULL) 1522 panic("ifa == NULL in nd6_dad_ns_input"); 1523 1524 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1525 if (V_dad_enhanced == 0) 1526 ndopt_nonce = NULL; 1527 dp = nd6_dad_find(ifa, ndopt_nonce); 1528 if (dp == NULL) 1529 return; 1530 1531 dp->dad_ns_icount++; 1532 nd6_dad_rele(dp); 1533 } 1534 1535 static void 1536 nd6_dad_na_input(struct ifaddr *ifa) 1537 { 1538 struct dadq *dp; 1539 1540 if (ifa == NULL) 1541 panic("ifa == NULL in nd6_dad_na_input"); 1542 1543 dp = nd6_dad_find(ifa, NULL); 1544 if (dp != NULL) { 1545 dp->dad_na_icount++; 1546 nd6_dad_rele(dp); 1547 } 1548 } 1549