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sys/netinet6/nd6_nbr.c
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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: releng/11.1/sys/netinet6/nd6_nbr.c 317067 2017-04-17 20:13:20Z asomers $"); 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 if (rib_lookup_info(ifp->if_fib, (struct sockaddr *)&dst6, 266 0, 0, &info) == 0) { 267 if ((info.rti_flags & RTF_ANNOUNCE) != 0 && 268 rt_gateway.sdl_family == AF_LINK) { 269 270 /* 271 * proxy NDP for single entry 272 */ 273 proxydl = *SDL(&rt_gateway); 274 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal( 275 ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 276 if (ifa) 277 proxy = 1; 278 } 279 } 280 } 281 if (ifa == NULL) { 282 /* 283 * We've got an NS packet, and we don't have that adddress 284 * assigned for us. We MUST silently ignore it. 285 * See RFC2461 7.2.3. 286 */ 287 goto freeit; 288 } 289 myaddr6 = *IFA_IN6(ifa); 290 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 291 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 292 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 293 goto freeit; 294 295 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 296 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 297 "(if %d, NS packet %d)\n", 298 ip6_sprintf(ip6bufs, &taddr6), 299 ifp->if_addrlen, lladdrlen - 2)); 300 goto bad; 301 } 302 303 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 304 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 305 ip6_sprintf(ip6bufs, &saddr6))); 306 goto freeit; 307 } 308 309 /* 310 * We have neighbor solicitation packet, with target address equals to 311 * one of my tentative address. 312 * 313 * src addr how to process? 314 * --- --- 315 * multicast of course, invalid (rejected in ip6_input) 316 * unicast somebody is doing address resolution -> ignore 317 * unspec dup address detection 318 * 319 * The processing is defined in RFC 2462. 320 */ 321 if (tentative) { 322 /* 323 * If source address is unspecified address, it is for 324 * duplicate address detection. 325 * 326 * If not, the packet is for addess resolution; 327 * silently ignore it. 328 */ 329 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 330 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 331 332 goto freeit; 333 } 334 335 /* 336 * If the source address is unspecified address, entries must not 337 * be created or updated. 338 * It looks that sender is performing DAD. Output NA toward 339 * all-node multicast address, to tell the sender that I'm using 340 * the address. 341 * S bit ("solicited") must be zero. 342 */ 343 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 344 struct in6_addr in6_all; 345 346 in6_all = in6addr_linklocal_allnodes; 347 if (in6_setscope(&in6_all, ifp, NULL) != 0) 348 goto bad; 349 nd6_na_output_fib(ifp, &in6_all, &taddr6, 350 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 351 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 352 M_GETFIB(m)); 353 goto freeit; 354 } 355 356 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 357 ND_NEIGHBOR_SOLICIT, 0); 358 359 nd6_na_output_fib(ifp, &saddr6, &taddr6, 360 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 361 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 362 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 363 freeit: 364 if (ifa != NULL) 365 ifa_free(ifa); 366 m_freem(m); 367 return; 368 369 bad: 370 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 371 ip6_sprintf(ip6bufs, &saddr6))); 372 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 373 ip6_sprintf(ip6bufs, &daddr6))); 374 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 375 ip6_sprintf(ip6bufs, &taddr6))); 376 ICMP6STAT_INC(icp6s_badns); 377 if (ifa != NULL) 378 ifa_free(ifa); 379 m_freem(m); 380 } 381 382 /* 383 * Output a Neighbor Solicitation Message. Caller specifies: 384 * - ICMP6 header source IP6 address 385 * - ND6 header target IP6 address 386 * - ND6 header source datalink address 387 * 388 * Based on RFC 2461 389 * Based on RFC 2462 (duplicate address detection) 390 * 391 * ln - for source address determination 392 * nonce - If non-NULL, NS is used for duplicate address detection and 393 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 394 */ 395 static void 396 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 397 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 398 uint8_t *nonce, u_int fibnum) 399 { 400 struct mbuf *m; 401 struct m_tag *mtag; 402 struct ip6_hdr *ip6; 403 struct nd_neighbor_solicit *nd_ns; 404 struct ip6_moptions im6o; 405 int icmp6len; 406 int maxlen; 407 caddr_t mac; 408 409 if (IN6_IS_ADDR_MULTICAST(taddr6)) 410 return; 411 412 /* estimate the size of message */ 413 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 414 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 415 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 416 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 417 __func__, max_linkhdr, maxlen, MCLBYTES)); 418 419 if (max_linkhdr + maxlen > MHLEN) 420 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 421 else 422 m = m_gethdr(M_NOWAIT, MT_DATA); 423 if (m == NULL) 424 return; 425 M_SETFIB(m, fibnum); 426 427 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 428 m->m_flags |= M_MCAST; 429 im6o.im6o_multicast_ifp = ifp; 430 im6o.im6o_multicast_hlim = 255; 431 im6o.im6o_multicast_loop = 0; 432 } 433 434 icmp6len = sizeof(*nd_ns); 435 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 436 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 437 438 /* fill neighbor solicitation packet */ 439 ip6 = mtod(m, struct ip6_hdr *); 440 ip6->ip6_flow = 0; 441 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 442 ip6->ip6_vfc |= IPV6_VERSION; 443 /* ip6->ip6_plen will be set later */ 444 ip6->ip6_nxt = IPPROTO_ICMPV6; 445 ip6->ip6_hlim = 255; 446 if (daddr6) 447 ip6->ip6_dst = *daddr6; 448 else { 449 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 450 ip6->ip6_dst.s6_addr16[1] = 0; 451 ip6->ip6_dst.s6_addr32[1] = 0; 452 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 453 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 454 ip6->ip6_dst.s6_addr8[12] = 0xff; 455 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 456 goto bad; 457 } 458 if (nonce == NULL) { 459 struct ifaddr *ifa = NULL; 460 461 /* 462 * RFC2461 7.2.2: 463 * "If the source address of the packet prompting the 464 * solicitation is the same as one of the addresses assigned 465 * to the outgoing interface, that address SHOULD be placed 466 * in the IP Source Address of the outgoing solicitation. 467 * Otherwise, any one of the addresses assigned to the 468 * interface should be used." 469 * 470 * We use the source address for the prompting packet 471 * (saddr6), if saddr6 belongs to the outgoing interface. 472 * Otherwise, we perform the source address selection as usual. 473 */ 474 475 if (saddr6 != NULL) 476 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 477 if (ifa != NULL) { 478 /* ip6_src set already. */ 479 ip6->ip6_src = *saddr6; 480 ifa_free(ifa); 481 } else { 482 int error; 483 struct in6_addr dst6, src6; 484 uint32_t scopeid; 485 486 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); 487 error = in6_selectsrc_addr(fibnum, &dst6, 488 scopeid, ifp, &src6, NULL); 489 if (error) { 490 char ip6buf[INET6_ADDRSTRLEN]; 491 nd6log((LOG_DEBUG, "%s: source can't be " 492 "determined: dst=%s, error=%d\n", __func__, 493 ip6_sprintf(ip6buf, &dst6), 494 error)); 495 goto bad; 496 } 497 ip6->ip6_src = src6; 498 } 499 } else { 500 /* 501 * Source address for DAD packet must always be IPv6 502 * unspecified address. (0::0) 503 * We actually don't have to 0-clear the address (we did it 504 * above), but we do so here explicitly to make the intention 505 * clearer. 506 */ 507 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 508 } 509 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 510 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 511 nd_ns->nd_ns_code = 0; 512 nd_ns->nd_ns_reserved = 0; 513 nd_ns->nd_ns_target = *taddr6; 514 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 515 516 /* 517 * Add source link-layer address option. 518 * 519 * spec implementation 520 * --- --- 521 * DAD packet MUST NOT do not add the option 522 * there's no link layer address: 523 * impossible do not add the option 524 * there's link layer address: 525 * Multicast NS MUST add one add the option 526 * Unicast NS SHOULD add one add the option 527 */ 528 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 529 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 530 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 531 /* 8 byte alignments... */ 532 optlen = (optlen + 7) & ~7; 533 534 m->m_pkthdr.len += optlen; 535 m->m_len += optlen; 536 icmp6len += optlen; 537 bzero((caddr_t)nd_opt, optlen); 538 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 539 nd_opt->nd_opt_len = optlen >> 3; 540 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 541 } 542 /* 543 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 544 * This behavior is documented as Enhanced Duplicate Address 545 * Detection in RFC 7527. 546 * net.inet6.ip6.dad_enhanced=0 disables this. 547 */ 548 if (V_dad_enhanced != 0 && nonce != NULL) { 549 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 550 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 551 /* 8-byte alignment is required. */ 552 optlen = (optlen + 7) & ~7; 553 554 m->m_pkthdr.len += optlen; 555 m->m_len += optlen; 556 icmp6len += optlen; 557 bzero((caddr_t)nd_opt, optlen); 558 nd_opt->nd_opt_type = ND_OPT_NONCE; 559 nd_opt->nd_opt_len = optlen >> 3; 560 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 561 } 562 ip6->ip6_plen = htons((u_short)icmp6len); 563 nd_ns->nd_ns_cksum = 0; 564 nd_ns->nd_ns_cksum = 565 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 566 567 if (send_sendso_input_hook != NULL) { 568 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 569 sizeof(unsigned short), M_NOWAIT); 570 if (mtag == NULL) 571 goto bad; 572 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 573 m_tag_prepend(m, mtag); 574 } 575 576 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 577 &im6o, NULL, NULL); 578 icmp6_ifstat_inc(ifp, ifs6_out_msg); 579 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 580 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 581 582 return; 583 584 bad: 585 m_freem(m); 586 } 587 588 #ifndef BURN_BRIDGES 589 void 590 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 591 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 592 { 593 594 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 595 } 596 #endif 597 /* 598 * Neighbor advertisement input handling. 599 * 600 * Based on RFC 2461 601 * Based on RFC 2462 (duplicate address detection) 602 * 603 * the following items are not implemented yet: 604 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 605 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 606 */ 607 void 608 nd6_na_input(struct mbuf *m, int off, int icmp6len) 609 { 610 struct ifnet *ifp = m->m_pkthdr.rcvif; 611 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 612 struct nd_neighbor_advert *nd_na; 613 struct in6_addr daddr6 = ip6->ip6_dst; 614 struct in6_addr taddr6; 615 int flags; 616 int is_router; 617 int is_solicited; 618 int is_override; 619 char *lladdr = NULL; 620 int lladdrlen = 0; 621 int checklink = 0; 622 struct ifaddr *ifa; 623 struct llentry *ln = NULL; 624 union nd_opts ndopts; 625 struct mbuf *chain = NULL; 626 struct sockaddr_in6 sin6; 627 u_char linkhdr[LLE_MAX_LINKHDR]; 628 size_t linkhdrsize; 629 int lladdr_off; 630 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 631 632 if (ip6->ip6_hlim != 255) { 633 nd6log((LOG_ERR, 634 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 635 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 636 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 637 goto bad; 638 } 639 640 #ifndef PULLDOWN_TEST 641 IP6_EXTHDR_CHECK(m, off, icmp6len,); 642 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 643 #else 644 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 645 if (nd_na == NULL) { 646 ICMP6STAT_INC(icp6s_tooshort); 647 return; 648 } 649 #endif 650 651 flags = nd_na->nd_na_flags_reserved; 652 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 653 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 654 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 655 memset(&sin6, 0, sizeof(sin6)); 656 657 taddr6 = nd_na->nd_na_target; 658 if (in6_setscope(&taddr6, ifp, NULL)) 659 goto bad; /* XXX: impossible */ 660 661 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 662 nd6log((LOG_ERR, 663 "nd6_na_input: invalid target address %s\n", 664 ip6_sprintf(ip6bufs, &taddr6))); 665 goto bad; 666 } 667 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 668 if (is_solicited) { 669 nd6log((LOG_ERR, 670 "nd6_na_input: a solicited adv is multicasted\n")); 671 goto bad; 672 } 673 674 icmp6len -= sizeof(*nd_na); 675 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 676 if (nd6_options(&ndopts) < 0) { 677 nd6log((LOG_INFO, 678 "nd6_na_input: invalid ND option, ignored\n")); 679 /* nd6_options have incremented stats */ 680 goto freeit; 681 } 682 683 if (ndopts.nd_opts_tgt_lladdr) { 684 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 685 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 686 } 687 688 /* 689 * This effectively disables the DAD check on a non-master CARP 690 * address. 691 */ 692 if (ifp->if_carp) 693 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 694 else 695 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 696 697 /* 698 * Target address matches one of my interface address. 699 * 700 * If my address is tentative, this means that there's somebody 701 * already using the same address as mine. This indicates DAD failure. 702 * This is defined in RFC 2462. 703 * 704 * Otherwise, process as defined in RFC 2461. 705 */ 706 if (ifa 707 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 708 nd6_dad_na_input(ifa); 709 ifa_free(ifa); 710 goto freeit; 711 } 712 713 /* Just for safety, maybe unnecessary. */ 714 if (ifa) { 715 ifa_free(ifa); 716 log(LOG_ERR, 717 "nd6_na_input: duplicate IP6 address %s\n", 718 ip6_sprintf(ip6bufs, &taddr6)); 719 goto freeit; 720 } 721 722 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 723 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 724 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 725 ifp->if_addrlen, lladdrlen - 2)); 726 goto bad; 727 } 728 729 /* 730 * If no neighbor cache entry is found, NA SHOULD silently be 731 * discarded. 732 */ 733 IF_AFDATA_RLOCK(ifp); 734 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 735 IF_AFDATA_RUNLOCK(ifp); 736 if (ln == NULL) { 737 goto freeit; 738 } 739 740 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 741 /* 742 * If the link-layer has address, and no lladdr option came, 743 * discard the packet. 744 */ 745 if (ifp->if_addrlen && lladdr == NULL) { 746 goto freeit; 747 } 748 749 /* 750 * Record link-layer address, and update the state. 751 */ 752 linkhdrsize = sizeof(linkhdr); 753 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 754 linkhdr, &linkhdrsize, &lladdr_off) != 0) 755 return; 756 757 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize, 758 lladdr_off) == 0) { 759 ln = NULL; 760 goto freeit; 761 } 762 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 763 if (is_solicited) 764 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 765 else 766 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 767 if ((ln->ln_router = is_router) != 0) { 768 /* 769 * This means a router's state has changed from 770 * non-reachable to probably reachable, and might 771 * affect the status of associated prefixes.. 772 */ 773 checklink = 1; 774 } 775 } else { 776 int llchange; 777 778 /* 779 * Check if the link-layer address has changed or not. 780 */ 781 if (lladdr == NULL) 782 llchange = 0; 783 else { 784 if (ln->la_flags & LLE_VALID) { 785 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 786 llchange = 1; 787 else 788 llchange = 0; 789 } else 790 llchange = 1; 791 } 792 793 /* 794 * This is VERY complex. Look at it with care. 795 * 796 * override solicit lladdr llchange action 797 * (L: record lladdr) 798 * 799 * 0 0 n -- (2c) 800 * 0 0 y n (2b) L 801 * 0 0 y y (1) REACHABLE->STALE 802 * 0 1 n -- (2c) *->REACHABLE 803 * 0 1 y n (2b) L *->REACHABLE 804 * 0 1 y y (1) REACHABLE->STALE 805 * 1 0 n -- (2a) 806 * 1 0 y n (2a) L 807 * 1 0 y y (2a) L *->STALE 808 * 1 1 n -- (2a) *->REACHABLE 809 * 1 1 y n (2a) L *->REACHABLE 810 * 1 1 y y (2a) L *->REACHABLE 811 */ 812 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 813 /* 814 * If state is REACHABLE, make it STALE. 815 * no other updates should be done. 816 */ 817 if (ln->ln_state == ND6_LLINFO_REACHABLE) 818 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 819 goto freeit; 820 } else if (is_override /* (2a) */ 821 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 822 || lladdr == NULL) { /* (2c) */ 823 /* 824 * Update link-local address, if any. 825 */ 826 if (lladdr != NULL) { 827 linkhdrsize = sizeof(linkhdr); 828 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 829 linkhdr, &linkhdrsize, &lladdr_off) != 0) 830 goto freeit; 831 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 832 linkhdrsize, lladdr_off) == 0) { 833 ln = NULL; 834 goto freeit; 835 } 836 EVENTHANDLER_INVOKE(lle_event, ln, 837 LLENTRY_RESOLVED); 838 } 839 840 /* 841 * If solicited, make the state REACHABLE. 842 * If not solicited and the link-layer address was 843 * changed, make it STALE. 844 */ 845 if (is_solicited) 846 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 847 else { 848 if (lladdr != NULL && llchange) 849 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 850 } 851 } 852 853 if (ln->ln_router && !is_router) { 854 /* 855 * The peer dropped the router flag. 856 * Remove the sender from the Default Router List and 857 * update the Destination Cache entries. 858 */ 859 struct ifnet *nd6_ifp; 860 861 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 862 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 863 (ND_IFINFO(nd6_ifp)->flags & 864 ND6_IFF_ACCEPT_RTADV) != 0) 865 /* 866 * Even if the neighbor is not in the default 867 * router list, the neighbor may be used as a 868 * next hop for some destinations (e.g. redirect 869 * case). So we must call rt6_flush explicitly. 870 */ 871 rt6_flush(&ip6->ip6_src, ifp); 872 } 873 ln->ln_router = is_router; 874 } 875 /* XXX - QL 876 * Does this matter? 877 * rt->rt_flags &= ~RTF_REJECT; 878 */ 879 ln->la_asked = 0; 880 if (ln->la_hold != NULL) 881 nd6_grab_holdchain(ln, &chain, &sin6); 882 freeit: 883 if (ln != NULL) 884 LLE_WUNLOCK(ln); 885 886 if (chain != NULL) 887 nd6_flush_holdchain(ifp, ifp, chain, &sin6); 888 889 if (checklink) 890 pfxlist_onlink_check(); 891 892 m_freem(m); 893 return; 894 895 bad: 896 if (ln != NULL) 897 LLE_WUNLOCK(ln); 898 899 ICMP6STAT_INC(icp6s_badna); 900 m_freem(m); 901 } 902 903 /* 904 * Neighbor advertisement output handling. 905 * 906 * Based on RFC 2461 907 * 908 * the following items are not implemented yet: 909 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 910 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 911 * 912 * tlladdr - 1 if include target link-layer address 913 * sdl0 - sockaddr_dl (= proxy NA) or NULL 914 */ 915 static void 916 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 917 const struct in6_addr *taddr6, u_long flags, int tlladdr, 918 struct sockaddr *sdl0, u_int fibnum) 919 { 920 struct mbuf *m; 921 struct m_tag *mtag; 922 struct ip6_hdr *ip6; 923 struct nd_neighbor_advert *nd_na; 924 struct ip6_moptions im6o; 925 struct in6_addr daddr6, dst6, src6; 926 uint32_t scopeid; 927 928 int icmp6len, maxlen, error; 929 caddr_t mac = NULL; 930 931 daddr6 = *daddr6_0; /* make a local copy for modification */ 932 933 /* estimate the size of message */ 934 maxlen = sizeof(*ip6) + sizeof(*nd_na); 935 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 936 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 937 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 938 __func__, max_linkhdr, maxlen, MCLBYTES)); 939 940 if (max_linkhdr + maxlen > MHLEN) 941 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 942 else 943 m = m_gethdr(M_NOWAIT, MT_DATA); 944 if (m == NULL) 945 return; 946 M_SETFIB(m, fibnum); 947 948 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 949 m->m_flags |= M_MCAST; 950 im6o.im6o_multicast_ifp = ifp; 951 im6o.im6o_multicast_hlim = 255; 952 im6o.im6o_multicast_loop = 0; 953 } 954 955 icmp6len = sizeof(*nd_na); 956 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 957 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 958 959 /* fill neighbor advertisement packet */ 960 ip6 = mtod(m, struct ip6_hdr *); 961 ip6->ip6_flow = 0; 962 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 963 ip6->ip6_vfc |= IPV6_VERSION; 964 ip6->ip6_nxt = IPPROTO_ICMPV6; 965 ip6->ip6_hlim = 255; 966 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 967 /* reply to DAD */ 968 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 969 daddr6.s6_addr16[1] = 0; 970 daddr6.s6_addr32[1] = 0; 971 daddr6.s6_addr32[2] = 0; 972 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 973 if (in6_setscope(&daddr6, ifp, NULL)) 974 goto bad; 975 976 flags &= ~ND_NA_FLAG_SOLICITED; 977 } 978 ip6->ip6_dst = daddr6; 979 980 /* 981 * Select a source whose scope is the same as that of the dest. 982 */ 983 in6_splitscope(&daddr6, &dst6, &scopeid); 984 error = in6_selectsrc_addr(fibnum, &dst6, 985 scopeid, ifp, &src6, NULL); 986 if (error) { 987 char ip6buf[INET6_ADDRSTRLEN]; 988 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 989 "determined: dst=%s, error=%d\n", 990 ip6_sprintf(ip6buf, &daddr6), error)); 991 goto bad; 992 } 993 ip6->ip6_src = src6; 994 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 995 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 996 nd_na->nd_na_code = 0; 997 nd_na->nd_na_target = *taddr6; 998 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 999 1000 /* 1001 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1002 * see nd6_ns_input() for details. 1003 * Basically, if NS packet is sent to unicast/anycast addr, 1004 * target lladdr option SHOULD NOT be included. 1005 */ 1006 if (tlladdr) { 1007 /* 1008 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1009 * lladdr in sdl0. If we are not proxying (sending NA for 1010 * my address) use lladdr configured for the interface. 1011 */ 1012 if (sdl0 == NULL) { 1013 if (ifp->if_carp) 1014 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1015 if (mac == NULL) 1016 mac = nd6_ifptomac(ifp); 1017 } else if (sdl0->sa_family == AF_LINK) { 1018 struct sockaddr_dl *sdl; 1019 sdl = (struct sockaddr_dl *)sdl0; 1020 if (sdl->sdl_alen == ifp->if_addrlen) 1021 mac = LLADDR(sdl); 1022 } 1023 } 1024 if (tlladdr && mac) { 1025 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1026 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1027 1028 /* roundup to 8 bytes alignment! */ 1029 optlen = (optlen + 7) & ~7; 1030 1031 m->m_pkthdr.len += optlen; 1032 m->m_len += optlen; 1033 icmp6len += optlen; 1034 bzero((caddr_t)nd_opt, optlen); 1035 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1036 nd_opt->nd_opt_len = optlen >> 3; 1037 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1038 } else 1039 flags &= ~ND_NA_FLAG_OVERRIDE; 1040 1041 ip6->ip6_plen = htons((u_short)icmp6len); 1042 nd_na->nd_na_flags_reserved = flags; 1043 nd_na->nd_na_cksum = 0; 1044 nd_na->nd_na_cksum = 1045 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1046 1047 if (send_sendso_input_hook != NULL) { 1048 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1049 sizeof(unsigned short), M_NOWAIT); 1050 if (mtag == NULL) 1051 goto bad; 1052 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1053 m_tag_prepend(m, mtag); 1054 } 1055 1056 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1057 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1058 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1059 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1060 1061 return; 1062 1063 bad: 1064 m_freem(m); 1065 } 1066 1067 #ifndef BURN_BRIDGES 1068 void 1069 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1070 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1071 struct sockaddr *sdl0) 1072 { 1073 1074 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1075 RT_DEFAULT_FIB); 1076 } 1077 #endif 1078 1079 caddr_t 1080 nd6_ifptomac(struct ifnet *ifp) 1081 { 1082 switch (ifp->if_type) { 1083 case IFT_ARCNET: 1084 case IFT_ETHER: 1085 case IFT_FDDI: 1086 case IFT_IEEE1394: 1087 case IFT_L2VLAN: 1088 case IFT_IEEE80211: 1089 case IFT_INFINIBAND: 1090 case IFT_BRIDGE: 1091 case IFT_ISO88025: 1092 return IF_LLADDR(ifp); 1093 default: 1094 return NULL; 1095 } 1096 } 1097 1098 struct dadq { 1099 TAILQ_ENTRY(dadq) dad_list; 1100 struct ifaddr *dad_ifa; 1101 int dad_count; /* max NS to send */ 1102 int dad_ns_tcount; /* # of trials to send NS */ 1103 int dad_ns_ocount; /* NS sent so far */ 1104 int dad_ns_icount; 1105 int dad_na_icount; 1106 int dad_ns_lcount; /* looped back NS */ 1107 int dad_loopbackprobe; /* probing state for loopback detection */ 1108 struct callout dad_timer_ch; 1109 struct vnet *dad_vnet; 1110 u_int dad_refcnt; 1111 #define ND_OPT_NONCE_LEN32 \ 1112 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1113 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1114 }; 1115 1116 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq); 1117 static VNET_DEFINE(struct rwlock, dad_rwlock); 1118 #define V_dadq VNET(dadq) 1119 #define V_dad_rwlock VNET(dad_rwlock) 1120 1121 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1122 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1123 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1124 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1125 1126 static void 1127 nd6_dad_add(struct dadq *dp) 1128 { 1129 1130 DADQ_WLOCK(); 1131 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1132 DADQ_WUNLOCK(); 1133 } 1134 1135 static void 1136 nd6_dad_del(struct dadq *dp) 1137 { 1138 1139 DADQ_WLOCK(); 1140 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1141 DADQ_WUNLOCK(); 1142 nd6_dad_rele(dp); 1143 } 1144 1145 static struct dadq * 1146 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1147 { 1148 struct dadq *dp; 1149 1150 DADQ_RLOCK(); 1151 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1152 if (dp->dad_ifa != ifa) 1153 continue; 1154 /* 1155 * Skip if the nonce matches the received one. 1156 * +2 in the length is required because of type and 1157 * length fields are included in a header. 1158 */ 1159 if (n != NULL && 1160 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1161 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1162 ND_OPT_NONCE_LEN) == 0) { 1163 dp->dad_ns_lcount++; 1164 continue; 1165 } 1166 refcount_acquire(&dp->dad_refcnt); 1167 break; 1168 } 1169 DADQ_RUNLOCK(); 1170 1171 return (dp); 1172 } 1173 1174 static void 1175 nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns) 1176 { 1177 1178 if (send_ns != 0) 1179 nd6_dad_ns_output(dp); 1180 callout_reset(&dp->dad_timer_ch, ticks, 1181 (void (*)(void *))nd6_dad_timer, (void *)dp); 1182 } 1183 1184 static void 1185 nd6_dad_stoptimer(struct dadq *dp) 1186 { 1187 1188 callout_drain(&dp->dad_timer_ch); 1189 } 1190 1191 static void 1192 nd6_dad_rele(struct dadq *dp) 1193 { 1194 1195 if (refcount_release(&dp->dad_refcnt)) { 1196 ifa_free(dp->dad_ifa); 1197 free(dp, M_IP6NDP); 1198 } 1199 } 1200 1201 void 1202 nd6_dad_init(void) 1203 { 1204 1205 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1206 TAILQ_INIT(&V_dadq); 1207 } 1208 1209 /* 1210 * Start Duplicate Address Detection (DAD) for specified interface address. 1211 */ 1212 void 1213 nd6_dad_start(struct ifaddr *ifa, int delay) 1214 { 1215 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1216 struct dadq *dp; 1217 char ip6buf[INET6_ADDRSTRLEN]; 1218 1219 /* 1220 * If we don't need DAD, don't do it. 1221 * There are several cases: 1222 * - DAD is disabled (ip6_dad_count == 0) 1223 * - the interface address is anycast 1224 */ 1225 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1226 log(LOG_DEBUG, 1227 "nd6_dad_start: called with non-tentative address " 1228 "%s(%s)\n", 1229 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1230 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1231 return; 1232 } 1233 if (ia->ia6_flags & IN6_IFF_ANYCAST) { 1234 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1235 return; 1236 } 1237 if (!V_ip6_dad_count) { 1238 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1239 return; 1240 } 1241 if (ifa->ifa_ifp == NULL) 1242 panic("nd6_dad_start: ifa->ifa_ifp == NULL"); 1243 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) { 1244 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1245 return; 1246 } 1247 if (!(ifa->ifa_ifp->if_flags & IFF_UP) || 1248 !(ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) || 1249 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED)) { 1250 ia->ia6_flags |= IN6_IFF_TENTATIVE; 1251 return; 1252 } 1253 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1254 /* 1255 * DAD is already in progress. Let the existing entry 1256 * finish it. 1257 */ 1258 nd6_dad_rele(dp); 1259 return; 1260 } 1261 1262 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1263 if (dp == NULL) { 1264 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1265 "%s(%s)\n", 1266 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1267 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1268 return; 1269 } 1270 callout_init(&dp->dad_timer_ch, 0); 1271 #ifdef VIMAGE 1272 dp->dad_vnet = curvnet; 1273 #endif 1274 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1275 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1276 1277 /* 1278 * Send NS packet for DAD, ip6_dad_count times. 1279 * Note that we must delay the first transmission, if this is the 1280 * first packet to be sent from the interface after interface 1281 * (re)initialization. 1282 */ 1283 dp->dad_ifa = ifa; 1284 ifa_ref(dp->dad_ifa); 1285 dp->dad_count = V_ip6_dad_count; 1286 dp->dad_ns_icount = dp->dad_na_icount = 0; 1287 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1288 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1289 refcount_init(&dp->dad_refcnt, 1); 1290 nd6_dad_add(dp); 1291 nd6_dad_starttimer(dp, delay, 0); 1292 } 1293 1294 /* 1295 * terminate DAD unconditionally. used for address removals. 1296 */ 1297 void 1298 nd6_dad_stop(struct ifaddr *ifa) 1299 { 1300 struct dadq *dp; 1301 1302 dp = nd6_dad_find(ifa, NULL); 1303 if (!dp) { 1304 /* DAD wasn't started yet */ 1305 return; 1306 } 1307 1308 nd6_dad_stoptimer(dp); 1309 1310 /* 1311 * The DAD queue entry may have been removed by nd6_dad_timer() while 1312 * we were waiting for it to stop, so re-do the lookup. 1313 */ 1314 nd6_dad_rele(dp); 1315 if (nd6_dad_find(ifa, NULL) == NULL) 1316 return; 1317 1318 nd6_dad_del(dp); 1319 nd6_dad_rele(dp); 1320 } 1321 1322 static void 1323 nd6_dad_timer(struct dadq *dp) 1324 { 1325 CURVNET_SET(dp->dad_vnet); 1326 struct ifaddr *ifa = dp->dad_ifa; 1327 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1328 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1329 char ip6buf[INET6_ADDRSTRLEN]; 1330 1331 /* Sanity check */ 1332 if (ia == NULL) { 1333 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n"); 1334 goto err; 1335 } 1336 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1337 /* Do not need DAD for ifdisabled interface. */ 1338 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1339 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1340 goto err; 1341 } 1342 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1343 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1344 "%s(%s)\n", 1345 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1346 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1347 goto err; 1348 } 1349 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1350 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1351 "%s(%s)\n", 1352 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1353 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1354 goto err; 1355 } 1356 1357 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1358 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1359 (((ifp->if_flags & IFF_UP) == 0) || 1360 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1361 nd6log((LOG_INFO, "%s: could not run DAD " 1362 "because the interface was down or not running.\n", 1363 if_name(ifa->ifa_ifp))); 1364 goto err; 1365 } 1366 1367 /* Need more checks? */ 1368 if (dp->dad_ns_ocount < dp->dad_count) { 1369 /* 1370 * We have more NS to go. Send NS packet for DAD. 1371 */ 1372 nd6_dad_starttimer(dp, 1373 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1); 1374 goto done; 1375 } else { 1376 /* 1377 * We have transmitted sufficient number of DAD packets. 1378 * See what we've got. 1379 */ 1380 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1381 /* We've seen NS or NA, means DAD has failed. */ 1382 nd6_dad_duplicated(ifa, dp); 1383 else if (V_dad_enhanced != 0 && 1384 dp->dad_ns_lcount > 0 && 1385 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1386 /* 1387 * Sec. 4.1 in RFC 7527 requires transmission of 1388 * additional probes until the loopback condition 1389 * becomes clear when a looped back probe is detected. 1390 */ 1391 log(LOG_ERR, "%s: a looped back NS message is " 1392 "detected during DAD for %s. " 1393 "Another DAD probes are being sent.\n", 1394 if_name(ifa->ifa_ifp), 1395 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1396 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1397 /* 1398 * Send an NS immediately and increase dad_count by 1399 * V_nd6_mmaxtries - 1. 1400 */ 1401 dp->dad_count = 1402 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1403 nd6_dad_starttimer(dp, 1404 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1405 1); 1406 goto done; 1407 } else { 1408 /* 1409 * We are done with DAD. No NA came, no NS came. 1410 * No duplicate address found. Check IFDISABLED flag 1411 * again in case that it is changed between the 1412 * beginning of this function and here. 1413 */ 1414 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1415 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1416 1417 nd6log((LOG_DEBUG, 1418 "%s: DAD complete for %s - no duplicates found\n", 1419 if_name(ifa->ifa_ifp), 1420 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1421 if (dp->dad_ns_lcount > 0) 1422 log(LOG_ERR, "%s: DAD completed while " 1423 "a looped back NS message is detected " 1424 "during DAD for %s.\n", 1425 if_name(ifa->ifa_ifp), 1426 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1427 } 1428 } 1429 err: 1430 nd6_dad_del(dp); 1431 done: 1432 CURVNET_RESTORE(); 1433 } 1434 1435 static void 1436 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1437 { 1438 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1439 struct ifnet *ifp; 1440 char ip6buf[INET6_ADDRSTRLEN]; 1441 1442 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1443 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1444 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1445 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1446 dp->dad_na_icount); 1447 1448 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1449 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1450 1451 ifp = ifa->ifa_ifp; 1452 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1453 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1454 log(LOG_ERR, "%s: manual intervention required\n", 1455 if_name(ifp)); 1456 1457 /* 1458 * If the address is a link-local address formed from an interface 1459 * identifier based on the hardware address which is supposed to be 1460 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1461 * operation on the interface SHOULD be disabled. 1462 * [RFC 4862, Section 5.4.5] 1463 */ 1464 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1465 struct in6_addr in6; 1466 1467 /* 1468 * To avoid over-reaction, we only apply this logic when we are 1469 * very sure that hardware addresses are supposed to be unique. 1470 */ 1471 switch (ifp->if_type) { 1472 case IFT_ETHER: 1473 case IFT_FDDI: 1474 case IFT_ATM: 1475 case IFT_IEEE1394: 1476 case IFT_IEEE80211: 1477 case IFT_INFINIBAND: 1478 in6 = ia->ia_addr.sin6_addr; 1479 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1480 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1481 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1482 log(LOG_ERR, "%s: possible hardware address " 1483 "duplication detected, disable IPv6\n", 1484 if_name(ifp)); 1485 } 1486 break; 1487 } 1488 } 1489 } 1490 1491 static void 1492 nd6_dad_ns_output(struct dadq *dp) 1493 { 1494 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1495 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1496 int i; 1497 1498 dp->dad_ns_tcount++; 1499 if ((ifp->if_flags & IFF_UP) == 0) { 1500 return; 1501 } 1502 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1503 return; 1504 } 1505 1506 dp->dad_ns_ocount++; 1507 if (V_dad_enhanced != 0) { 1508 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1509 dp->dad_nonce[i] = arc4random(); 1510 /* 1511 * XXXHRS: Note that in the case that 1512 * DupAddrDetectTransmits > 1, multiple NS messages with 1513 * different nonces can be looped back in an unexpected 1514 * order. The current implementation recognizes only 1515 * the latest nonce on the sender side. Practically it 1516 * should work well in almost all cases. 1517 */ 1518 } 1519 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1520 (uint8_t *)&dp->dad_nonce[0]); 1521 } 1522 1523 static void 1524 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1525 { 1526 struct in6_ifaddr *ia; 1527 struct ifnet *ifp; 1528 const struct in6_addr *taddr6; 1529 struct dadq *dp; 1530 1531 if (ifa == NULL) 1532 panic("ifa == NULL in nd6_dad_ns_input"); 1533 1534 ia = (struct in6_ifaddr *)ifa; 1535 ifp = ifa->ifa_ifp; 1536 taddr6 = &ia->ia_addr.sin6_addr; 1537 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1538 if (V_dad_enhanced == 0) 1539 ndopt_nonce = NULL; 1540 dp = nd6_dad_find(ifa, ndopt_nonce); 1541 if (dp == NULL) 1542 return; 1543 1544 dp->dad_ns_icount++; 1545 nd6_dad_rele(dp); 1546 } 1547 1548 static void 1549 nd6_dad_na_input(struct ifaddr *ifa) 1550 { 1551 struct dadq *dp; 1552 1553 if (ifa == NULL) 1554 panic("ifa == NULL in nd6_dad_na_input"); 1555 1556 dp = nd6_dad_find(ifa, NULL); 1557 if (dp != NULL) { 1558 dp->dad_na_icount++; 1559 nd6_dad_rele(dp); 1560 } 1561 }
Cache object: 6181605497561af9a8c2126e383bdee6
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