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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/11.2/sys/netinet6/nd6_nbr.c 332819 2018-04-20 14:21:37Z jtl $"); 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 /* RFC 6980: Nodes MUST silently ignore fragments */ 139 if(m->m_flags & M_FRAGMENTED) 140 goto freeit; 141 142 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 143 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 144 rflag = 0; 145 #ifndef PULLDOWN_TEST 146 IP6_EXTHDR_CHECK(m, off, icmp6len,); 147 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 148 #else 149 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); 150 if (nd_ns == NULL) { 151 ICMP6STAT_INC(icp6s_tooshort); 152 return; 153 } 154 #endif 155 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ 156 taddr6 = nd_ns->nd_ns_target; 157 if (in6_setscope(&taddr6, ifp, NULL) != 0) 158 goto bad; 159 160 if (ip6->ip6_hlim != 255) { 161 nd6log((LOG_ERR, 162 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 163 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 164 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 165 goto bad; 166 } 167 168 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 169 /* dst has to be a solicited node multicast address. */ 170 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 171 /* don't check ifindex portion */ 172 daddr6.s6_addr32[1] == 0 && 173 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 174 daddr6.s6_addr8[12] == 0xff) { 175 ; /* good */ 176 } else { 177 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 178 "(wrong ip6 dst)\n")); 179 goto bad; 180 } 181 } else if (!V_nd6_onlink_ns_rfc4861) { 182 struct sockaddr_in6 src_sa6; 183 184 /* 185 * According to recent IETF discussions, it is not a good idea 186 * to accept a NS from an address which would not be deemed 187 * to be a neighbor otherwise. This point is expected to be 188 * clarified in future revisions of the specification. 189 */ 190 bzero(&src_sa6, sizeof(src_sa6)); 191 src_sa6.sin6_family = AF_INET6; 192 src_sa6.sin6_len = sizeof(src_sa6); 193 src_sa6.sin6_addr = saddr6; 194 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 195 nd6log((LOG_INFO, "nd6_ns_input: " 196 "NS packet from non-neighbor\n")); 197 goto bad; 198 } 199 } 200 201 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 202 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 203 goto bad; 204 } 205 206 icmp6len -= sizeof(*nd_ns); 207 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 208 if (nd6_options(&ndopts) < 0) { 209 nd6log((LOG_INFO, 210 "nd6_ns_input: invalid ND option, ignored\n")); 211 /* nd6_options have incremented stats */ 212 goto freeit; 213 } 214 215 if (ndopts.nd_opts_src_lladdr) { 216 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 217 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 218 } 219 220 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 221 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 222 "(link-layer address option)\n")); 223 goto bad; 224 } 225 226 /* 227 * Attaching target link-layer address to the NA? 228 * (RFC 2461 7.2.4) 229 * 230 * NS IP dst is unicast/anycast MUST NOT add 231 * NS IP dst is solicited-node multicast MUST add 232 * 233 * In implementation, we add target link-layer address by default. 234 * We do not add one in MUST NOT cases. 235 */ 236 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 237 tlladdr = 0; 238 else 239 tlladdr = 1; 240 241 /* 242 * Target address (taddr6) must be either: 243 * (1) Valid unicast/anycast address for my receiving interface, 244 * (2) Unicast address for which I'm offering proxy service, or 245 * (3) "tentative" address on which DAD is being performed. 246 */ 247 /* (1) and (3) check. */ 248 if (ifp->if_carp) 249 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 250 else 251 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 252 253 /* (2) check. */ 254 if (ifa == NULL) { 255 struct sockaddr_dl rt_gateway; 256 struct rt_addrinfo info; 257 struct sockaddr_in6 dst6; 258 259 bzero(&dst6, sizeof(dst6)); 260 dst6.sin6_len = sizeof(struct sockaddr_in6); 261 dst6.sin6_family = AF_INET6; 262 dst6.sin6_addr = taddr6; 263 264 bzero(&rt_gateway, sizeof(rt_gateway)); 265 rt_gateway.sdl_len = sizeof(rt_gateway); 266 bzero(&info, sizeof(info)); 267 info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway; 268 269 if (rib_lookup_info(ifp->if_fib, (struct sockaddr *)&dst6, 270 0, 0, &info) == 0) { 271 if ((info.rti_flags & RTF_ANNOUNCE) != 0 && 272 rt_gateway.sdl_family == AF_LINK) { 273 274 /* 275 * proxy NDP for single entry 276 */ 277 proxydl = *SDL(&rt_gateway); 278 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal( 279 ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 280 if (ifa) 281 proxy = 1; 282 } 283 } 284 } 285 if (ifa == NULL) { 286 /* 287 * We've got an NS packet, and we don't have that adddress 288 * assigned for us. We MUST silently ignore it. 289 * See RFC2461 7.2.3. 290 */ 291 goto freeit; 292 } 293 myaddr6 = *IFA_IN6(ifa); 294 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 295 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 296 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 297 goto freeit; 298 299 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 300 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 301 "(if %d, NS packet %d)\n", 302 ip6_sprintf(ip6bufs, &taddr6), 303 ifp->if_addrlen, lladdrlen - 2)); 304 goto bad; 305 } 306 307 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 308 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 309 ip6_sprintf(ip6bufs, &saddr6))); 310 goto freeit; 311 } 312 313 /* 314 * We have neighbor solicitation packet, with target address equals to 315 * one of my tentative address. 316 * 317 * src addr how to process? 318 * --- --- 319 * multicast of course, invalid (rejected in ip6_input) 320 * unicast somebody is doing address resolution -> ignore 321 * unspec dup address detection 322 * 323 * The processing is defined in RFC 2462. 324 */ 325 if (tentative) { 326 /* 327 * If source address is unspecified address, it is for 328 * duplicate address detection. 329 * 330 * If not, the packet is for addess resolution; 331 * silently ignore it. 332 */ 333 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 334 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 335 336 goto freeit; 337 } 338 339 /* 340 * If the source address is unspecified address, entries must not 341 * be created or updated. 342 * It looks that sender is performing DAD. Output NA toward 343 * all-node multicast address, to tell the sender that I'm using 344 * the address. 345 * S bit ("solicited") must be zero. 346 */ 347 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 348 struct in6_addr in6_all; 349 350 in6_all = in6addr_linklocal_allnodes; 351 if (in6_setscope(&in6_all, ifp, NULL) != 0) 352 goto bad; 353 nd6_na_output_fib(ifp, &in6_all, &taddr6, 354 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 355 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 356 M_GETFIB(m)); 357 goto freeit; 358 } 359 360 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 361 ND_NEIGHBOR_SOLICIT, 0); 362 363 nd6_na_output_fib(ifp, &saddr6, &taddr6, 364 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 365 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 366 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 367 freeit: 368 if (ifa != NULL) 369 ifa_free(ifa); 370 m_freem(m); 371 return; 372 373 bad: 374 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 375 ip6_sprintf(ip6bufs, &saddr6))); 376 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 377 ip6_sprintf(ip6bufs, &daddr6))); 378 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 379 ip6_sprintf(ip6bufs, &taddr6))); 380 ICMP6STAT_INC(icp6s_badns); 381 if (ifa != NULL) 382 ifa_free(ifa); 383 m_freem(m); 384 } 385 386 /* 387 * Output a Neighbor Solicitation Message. Caller specifies: 388 * - ICMP6 header source IP6 address 389 * - ND6 header target IP6 address 390 * - ND6 header source datalink address 391 * 392 * Based on RFC 2461 393 * Based on RFC 2462 (duplicate address detection) 394 * 395 * ln - for source address determination 396 * nonce - If non-NULL, NS is used for duplicate address detection and 397 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 398 */ 399 static void 400 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 401 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 402 uint8_t *nonce, u_int fibnum) 403 { 404 struct mbuf *m; 405 struct m_tag *mtag; 406 struct ip6_hdr *ip6; 407 struct nd_neighbor_solicit *nd_ns; 408 struct ip6_moptions im6o; 409 int icmp6len; 410 int maxlen; 411 caddr_t mac; 412 413 if (IN6_IS_ADDR_MULTICAST(taddr6)) 414 return; 415 416 /* estimate the size of message */ 417 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 418 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 419 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 420 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 421 __func__, max_linkhdr, maxlen, MCLBYTES)); 422 423 if (max_linkhdr + maxlen > MHLEN) 424 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 425 else 426 m = m_gethdr(M_NOWAIT, MT_DATA); 427 if (m == NULL) 428 return; 429 M_SETFIB(m, fibnum); 430 431 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 432 m->m_flags |= M_MCAST; 433 im6o.im6o_multicast_ifp = ifp; 434 im6o.im6o_multicast_hlim = 255; 435 im6o.im6o_multicast_loop = 0; 436 } 437 438 icmp6len = sizeof(*nd_ns); 439 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 440 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 441 442 /* fill neighbor solicitation packet */ 443 ip6 = mtod(m, struct ip6_hdr *); 444 ip6->ip6_flow = 0; 445 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 446 ip6->ip6_vfc |= IPV6_VERSION; 447 /* ip6->ip6_plen will be set later */ 448 ip6->ip6_nxt = IPPROTO_ICMPV6; 449 ip6->ip6_hlim = 255; 450 if (daddr6) 451 ip6->ip6_dst = *daddr6; 452 else { 453 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 454 ip6->ip6_dst.s6_addr16[1] = 0; 455 ip6->ip6_dst.s6_addr32[1] = 0; 456 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 457 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 458 ip6->ip6_dst.s6_addr8[12] = 0xff; 459 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 460 goto bad; 461 } 462 if (nonce == NULL) { 463 struct ifaddr *ifa = NULL; 464 465 /* 466 * RFC2461 7.2.2: 467 * "If the source address of the packet prompting the 468 * solicitation is the same as one of the addresses assigned 469 * to the outgoing interface, that address SHOULD be placed 470 * in the IP Source Address of the outgoing solicitation. 471 * Otherwise, any one of the addresses assigned to the 472 * interface should be used." 473 * 474 * We use the source address for the prompting packet 475 * (saddr6), if saddr6 belongs to the outgoing interface. 476 * Otherwise, we perform the source address selection as usual. 477 */ 478 479 if (saddr6 != NULL) 480 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 481 if (ifa != NULL) { 482 /* ip6_src set already. */ 483 ip6->ip6_src = *saddr6; 484 ifa_free(ifa); 485 } else { 486 int error; 487 struct in6_addr dst6, src6; 488 uint32_t scopeid; 489 490 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); 491 error = in6_selectsrc_addr(fibnum, &dst6, 492 scopeid, ifp, &src6, NULL); 493 if (error) { 494 char ip6buf[INET6_ADDRSTRLEN]; 495 nd6log((LOG_DEBUG, "%s: source can't be " 496 "determined: dst=%s, error=%d\n", __func__, 497 ip6_sprintf(ip6buf, &dst6), 498 error)); 499 goto bad; 500 } 501 ip6->ip6_src = src6; 502 } 503 } else { 504 /* 505 * Source address for DAD packet must always be IPv6 506 * unspecified address. (0::0) 507 * We actually don't have to 0-clear the address (we did it 508 * above), but we do so here explicitly to make the intention 509 * clearer. 510 */ 511 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 512 } 513 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 514 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 515 nd_ns->nd_ns_code = 0; 516 nd_ns->nd_ns_reserved = 0; 517 nd_ns->nd_ns_target = *taddr6; 518 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 519 520 /* 521 * Add source link-layer address option. 522 * 523 * spec implementation 524 * --- --- 525 * DAD packet MUST NOT do not add the option 526 * there's no link layer address: 527 * impossible do not add the option 528 * there's link layer address: 529 * Multicast NS MUST add one add the option 530 * Unicast NS SHOULD add one add the option 531 */ 532 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 533 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 534 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 535 /* 8 byte alignments... */ 536 optlen = (optlen + 7) & ~7; 537 538 m->m_pkthdr.len += optlen; 539 m->m_len += optlen; 540 icmp6len += optlen; 541 bzero((caddr_t)nd_opt, optlen); 542 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 543 nd_opt->nd_opt_len = optlen >> 3; 544 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 545 } 546 /* 547 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 548 * This behavior is documented as Enhanced Duplicate Address 549 * Detection in RFC 7527. 550 * net.inet6.ip6.dad_enhanced=0 disables this. 551 */ 552 if (V_dad_enhanced != 0 && nonce != NULL) { 553 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 554 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 555 /* 8-byte alignment is required. */ 556 optlen = (optlen + 7) & ~7; 557 558 m->m_pkthdr.len += optlen; 559 m->m_len += optlen; 560 icmp6len += optlen; 561 bzero((caddr_t)nd_opt, optlen); 562 nd_opt->nd_opt_type = ND_OPT_NONCE; 563 nd_opt->nd_opt_len = optlen >> 3; 564 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 565 } 566 ip6->ip6_plen = htons((u_short)icmp6len); 567 nd_ns->nd_ns_cksum = 0; 568 nd_ns->nd_ns_cksum = 569 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 570 571 if (send_sendso_input_hook != NULL) { 572 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 573 sizeof(unsigned short), M_NOWAIT); 574 if (mtag == NULL) 575 goto bad; 576 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 577 m_tag_prepend(m, mtag); 578 } 579 580 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 581 &im6o, NULL, NULL); 582 icmp6_ifstat_inc(ifp, ifs6_out_msg); 583 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 584 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 585 586 return; 587 588 bad: 589 m_freem(m); 590 } 591 592 #ifndef BURN_BRIDGES 593 void 594 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 595 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 596 { 597 598 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 599 } 600 #endif 601 /* 602 * Neighbor advertisement input handling. 603 * 604 * Based on RFC 2461 605 * Based on RFC 2462 (duplicate address detection) 606 * 607 * the following items are not implemented yet: 608 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 609 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 610 */ 611 void 612 nd6_na_input(struct mbuf *m, int off, int icmp6len) 613 { 614 struct ifnet *ifp = m->m_pkthdr.rcvif; 615 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 616 struct nd_neighbor_advert *nd_na; 617 struct in6_addr daddr6 = ip6->ip6_dst; 618 struct in6_addr taddr6; 619 int flags; 620 int is_router; 621 int is_solicited; 622 int is_override; 623 char *lladdr = NULL; 624 int lladdrlen = 0; 625 int checklink = 0; 626 struct ifaddr *ifa; 627 struct llentry *ln = NULL; 628 union nd_opts ndopts; 629 struct mbuf *chain = NULL; 630 struct sockaddr_in6 sin6; 631 u_char linkhdr[LLE_MAX_LINKHDR]; 632 size_t linkhdrsize; 633 int lladdr_off; 634 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 635 636 /* RFC 6980: Nodes MUST silently ignore fragments */ 637 if(m->m_flags & M_FRAGMENTED) 638 goto freeit; 639 640 if (ip6->ip6_hlim != 255) { 641 nd6log((LOG_ERR, 642 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 643 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 644 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 645 goto bad; 646 } 647 648 #ifndef PULLDOWN_TEST 649 IP6_EXTHDR_CHECK(m, off, icmp6len,); 650 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 651 #else 652 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 653 if (nd_na == NULL) { 654 ICMP6STAT_INC(icp6s_tooshort); 655 return; 656 } 657 #endif 658 659 flags = nd_na->nd_na_flags_reserved; 660 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 661 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 662 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 663 memset(&sin6, 0, sizeof(sin6)); 664 665 taddr6 = nd_na->nd_na_target; 666 if (in6_setscope(&taddr6, ifp, NULL)) 667 goto bad; /* XXX: impossible */ 668 669 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 670 nd6log((LOG_ERR, 671 "nd6_na_input: invalid target address %s\n", 672 ip6_sprintf(ip6bufs, &taddr6))); 673 goto bad; 674 } 675 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 676 if (is_solicited) { 677 nd6log((LOG_ERR, 678 "nd6_na_input: a solicited adv is multicasted\n")); 679 goto bad; 680 } 681 682 icmp6len -= sizeof(*nd_na); 683 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 684 if (nd6_options(&ndopts) < 0) { 685 nd6log((LOG_INFO, 686 "nd6_na_input: invalid ND option, ignored\n")); 687 /* nd6_options have incremented stats */ 688 goto freeit; 689 } 690 691 if (ndopts.nd_opts_tgt_lladdr) { 692 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 693 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 694 } 695 696 /* 697 * This effectively disables the DAD check on a non-master CARP 698 * address. 699 */ 700 if (ifp->if_carp) 701 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 702 else 703 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 704 705 /* 706 * Target address matches one of my interface address. 707 * 708 * If my address is tentative, this means that there's somebody 709 * already using the same address as mine. This indicates DAD failure. 710 * This is defined in RFC 2462. 711 * 712 * Otherwise, process as defined in RFC 2461. 713 */ 714 if (ifa 715 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 716 nd6_dad_na_input(ifa); 717 ifa_free(ifa); 718 goto freeit; 719 } 720 721 /* Just for safety, maybe unnecessary. */ 722 if (ifa) { 723 ifa_free(ifa); 724 log(LOG_ERR, 725 "nd6_na_input: duplicate IP6 address %s\n", 726 ip6_sprintf(ip6bufs, &taddr6)); 727 goto freeit; 728 } 729 730 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 731 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 732 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 733 ifp->if_addrlen, lladdrlen - 2)); 734 goto bad; 735 } 736 737 /* 738 * If no neighbor cache entry is found, NA SHOULD silently be 739 * discarded. 740 */ 741 IF_AFDATA_RLOCK(ifp); 742 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 743 IF_AFDATA_RUNLOCK(ifp); 744 if (ln == NULL) { 745 goto freeit; 746 } 747 748 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 749 /* 750 * If the link-layer has address, and no lladdr option came, 751 * discard the packet. 752 */ 753 if (ifp->if_addrlen && lladdr == NULL) { 754 goto freeit; 755 } 756 757 /* 758 * Record link-layer address, and update the state. 759 */ 760 linkhdrsize = sizeof(linkhdr); 761 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 762 linkhdr, &linkhdrsize, &lladdr_off) != 0) 763 return; 764 765 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize, 766 lladdr_off) == 0) { 767 ln = NULL; 768 goto freeit; 769 } 770 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 771 if (is_solicited) 772 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 773 else 774 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 775 if ((ln->ln_router = is_router) != 0) { 776 /* 777 * This means a router's state has changed from 778 * non-reachable to probably reachable, and might 779 * affect the status of associated prefixes.. 780 */ 781 checklink = 1; 782 } 783 } else { 784 int llchange; 785 786 /* 787 * Check if the link-layer address has changed or not. 788 */ 789 if (lladdr == NULL) 790 llchange = 0; 791 else { 792 if (ln->la_flags & LLE_VALID) { 793 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 794 llchange = 1; 795 else 796 llchange = 0; 797 } else 798 llchange = 1; 799 } 800 801 /* 802 * This is VERY complex. Look at it with care. 803 * 804 * override solicit lladdr llchange action 805 * (L: record lladdr) 806 * 807 * 0 0 n -- (2c) 808 * 0 0 y n (2b) L 809 * 0 0 y y (1) REACHABLE->STALE 810 * 0 1 n -- (2c) *->REACHABLE 811 * 0 1 y n (2b) L *->REACHABLE 812 * 0 1 y y (1) REACHABLE->STALE 813 * 1 0 n -- (2a) 814 * 1 0 y n (2a) L 815 * 1 0 y y (2a) L *->STALE 816 * 1 1 n -- (2a) *->REACHABLE 817 * 1 1 y n (2a) L *->REACHABLE 818 * 1 1 y y (2a) L *->REACHABLE 819 */ 820 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 821 /* 822 * If state is REACHABLE, make it STALE. 823 * no other updates should be done. 824 */ 825 if (ln->ln_state == ND6_LLINFO_REACHABLE) 826 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 827 goto freeit; 828 } else if (is_override /* (2a) */ 829 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 830 || lladdr == NULL) { /* (2c) */ 831 /* 832 * Update link-local address, if any. 833 */ 834 if (lladdr != NULL) { 835 linkhdrsize = sizeof(linkhdr); 836 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 837 linkhdr, &linkhdrsize, &lladdr_off) != 0) 838 goto freeit; 839 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 840 linkhdrsize, lladdr_off) == 0) { 841 ln = NULL; 842 goto freeit; 843 } 844 EVENTHANDLER_INVOKE(lle_event, ln, 845 LLENTRY_RESOLVED); 846 } 847 848 /* 849 * If solicited, make the state REACHABLE. 850 * If not solicited and the link-layer address was 851 * changed, make it STALE. 852 */ 853 if (is_solicited) 854 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 855 else { 856 if (lladdr != NULL && llchange) 857 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 858 } 859 } 860 861 if (ln->ln_router && !is_router) { 862 /* 863 * The peer dropped the router flag. 864 * Remove the sender from the Default Router List and 865 * update the Destination Cache entries. 866 */ 867 struct ifnet *nd6_ifp; 868 869 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 870 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 871 (ND_IFINFO(nd6_ifp)->flags & 872 ND6_IFF_ACCEPT_RTADV) != 0) 873 /* 874 * Even if the neighbor is not in the default 875 * router list, the neighbor may be used as a 876 * next hop for some destinations (e.g. redirect 877 * case). So we must call rt6_flush explicitly. 878 */ 879 rt6_flush(&ip6->ip6_src, ifp); 880 } 881 ln->ln_router = is_router; 882 } 883 /* XXX - QL 884 * Does this matter? 885 * rt->rt_flags &= ~RTF_REJECT; 886 */ 887 ln->la_asked = 0; 888 if (ln->la_hold != NULL) 889 nd6_grab_holdchain(ln, &chain, &sin6); 890 freeit: 891 if (ln != NULL) 892 LLE_WUNLOCK(ln); 893 894 if (chain != NULL) 895 nd6_flush_holdchain(ifp, ifp, chain, &sin6); 896 897 if (checklink) 898 pfxlist_onlink_check(); 899 900 m_freem(m); 901 return; 902 903 bad: 904 if (ln != NULL) 905 LLE_WUNLOCK(ln); 906 907 ICMP6STAT_INC(icp6s_badna); 908 m_freem(m); 909 } 910 911 /* 912 * Neighbor advertisement output handling. 913 * 914 * Based on RFC 2461 915 * 916 * the following items are not implemented yet: 917 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 918 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 919 * 920 * tlladdr - 1 if include target link-layer address 921 * sdl0 - sockaddr_dl (= proxy NA) or NULL 922 */ 923 static void 924 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 925 const struct in6_addr *taddr6, u_long flags, int tlladdr, 926 struct sockaddr *sdl0, u_int fibnum) 927 { 928 struct mbuf *m; 929 struct m_tag *mtag; 930 struct ip6_hdr *ip6; 931 struct nd_neighbor_advert *nd_na; 932 struct ip6_moptions im6o; 933 struct in6_addr daddr6, dst6, src6; 934 uint32_t scopeid; 935 936 int icmp6len, maxlen, error; 937 caddr_t mac = NULL; 938 939 daddr6 = *daddr6_0; /* make a local copy for modification */ 940 941 /* estimate the size of message */ 942 maxlen = sizeof(*ip6) + sizeof(*nd_na); 943 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 944 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 945 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 946 __func__, max_linkhdr, maxlen, MCLBYTES)); 947 948 if (max_linkhdr + maxlen > MHLEN) 949 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 950 else 951 m = m_gethdr(M_NOWAIT, MT_DATA); 952 if (m == NULL) 953 return; 954 M_SETFIB(m, fibnum); 955 956 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 957 m->m_flags |= M_MCAST; 958 im6o.im6o_multicast_ifp = ifp; 959 im6o.im6o_multicast_hlim = 255; 960 im6o.im6o_multicast_loop = 0; 961 } 962 963 icmp6len = sizeof(*nd_na); 964 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 965 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 966 967 /* fill neighbor advertisement packet */ 968 ip6 = mtod(m, struct ip6_hdr *); 969 ip6->ip6_flow = 0; 970 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 971 ip6->ip6_vfc |= IPV6_VERSION; 972 ip6->ip6_nxt = IPPROTO_ICMPV6; 973 ip6->ip6_hlim = 255; 974 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 975 /* reply to DAD */ 976 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 977 daddr6.s6_addr16[1] = 0; 978 daddr6.s6_addr32[1] = 0; 979 daddr6.s6_addr32[2] = 0; 980 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 981 if (in6_setscope(&daddr6, ifp, NULL)) 982 goto bad; 983 984 flags &= ~ND_NA_FLAG_SOLICITED; 985 } 986 ip6->ip6_dst = daddr6; 987 988 /* 989 * Select a source whose scope is the same as that of the dest. 990 */ 991 in6_splitscope(&daddr6, &dst6, &scopeid); 992 error = in6_selectsrc_addr(fibnum, &dst6, 993 scopeid, ifp, &src6, NULL); 994 if (error) { 995 char ip6buf[INET6_ADDRSTRLEN]; 996 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 997 "determined: dst=%s, error=%d\n", 998 ip6_sprintf(ip6buf, &daddr6), error)); 999 goto bad; 1000 } 1001 ip6->ip6_src = src6; 1002 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1003 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1004 nd_na->nd_na_code = 0; 1005 nd_na->nd_na_target = *taddr6; 1006 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1007 1008 /* 1009 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1010 * see nd6_ns_input() for details. 1011 * Basically, if NS packet is sent to unicast/anycast addr, 1012 * target lladdr option SHOULD NOT be included. 1013 */ 1014 if (tlladdr) { 1015 /* 1016 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1017 * lladdr in sdl0. If we are not proxying (sending NA for 1018 * my address) use lladdr configured for the interface. 1019 */ 1020 if (sdl0 == NULL) { 1021 if (ifp->if_carp) 1022 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1023 if (mac == NULL) 1024 mac = nd6_ifptomac(ifp); 1025 } else if (sdl0->sa_family == AF_LINK) { 1026 struct sockaddr_dl *sdl; 1027 sdl = (struct sockaddr_dl *)sdl0; 1028 if (sdl->sdl_alen == ifp->if_addrlen) 1029 mac = LLADDR(sdl); 1030 } 1031 } 1032 if (tlladdr && mac) { 1033 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1034 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1035 1036 /* roundup to 8 bytes alignment! */ 1037 optlen = (optlen + 7) & ~7; 1038 1039 m->m_pkthdr.len += optlen; 1040 m->m_len += optlen; 1041 icmp6len += optlen; 1042 bzero((caddr_t)nd_opt, optlen); 1043 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1044 nd_opt->nd_opt_len = optlen >> 3; 1045 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1046 } else 1047 flags &= ~ND_NA_FLAG_OVERRIDE; 1048 1049 ip6->ip6_plen = htons((u_short)icmp6len); 1050 nd_na->nd_na_flags_reserved = flags; 1051 nd_na->nd_na_cksum = 0; 1052 nd_na->nd_na_cksum = 1053 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1054 1055 if (send_sendso_input_hook != NULL) { 1056 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1057 sizeof(unsigned short), M_NOWAIT); 1058 if (mtag == NULL) 1059 goto bad; 1060 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1061 m_tag_prepend(m, mtag); 1062 } 1063 1064 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1065 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1066 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1067 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1068 1069 return; 1070 1071 bad: 1072 m_freem(m); 1073 } 1074 1075 #ifndef BURN_BRIDGES 1076 void 1077 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1078 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1079 struct sockaddr *sdl0) 1080 { 1081 1082 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1083 RT_DEFAULT_FIB); 1084 } 1085 #endif 1086 1087 caddr_t 1088 nd6_ifptomac(struct ifnet *ifp) 1089 { 1090 switch (ifp->if_type) { 1091 case IFT_ARCNET: 1092 case IFT_ETHER: 1093 case IFT_FDDI: 1094 case IFT_IEEE1394: 1095 case IFT_L2VLAN: 1096 case IFT_IEEE80211: 1097 case IFT_INFINIBAND: 1098 case IFT_BRIDGE: 1099 case IFT_ISO88025: 1100 return IF_LLADDR(ifp); 1101 default: 1102 return NULL; 1103 } 1104 } 1105 1106 struct dadq { 1107 TAILQ_ENTRY(dadq) dad_list; 1108 struct ifaddr *dad_ifa; 1109 int dad_count; /* max NS to send */ 1110 int dad_ns_tcount; /* # of trials to send NS */ 1111 int dad_ns_ocount; /* NS sent so far */ 1112 int dad_ns_icount; 1113 int dad_na_icount; 1114 int dad_ns_lcount; /* looped back NS */ 1115 int dad_loopbackprobe; /* probing state for loopback detection */ 1116 struct callout dad_timer_ch; 1117 struct vnet *dad_vnet; 1118 u_int dad_refcnt; 1119 #define ND_OPT_NONCE_LEN32 \ 1120 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1121 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1122 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */ 1123 }; 1124 1125 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq); 1126 static VNET_DEFINE(struct rwlock, dad_rwlock); 1127 #define V_dadq VNET(dadq) 1128 #define V_dad_rwlock VNET(dad_rwlock) 1129 1130 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1131 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1132 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1133 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1134 1135 static void 1136 nd6_dad_add(struct dadq *dp) 1137 { 1138 1139 DADQ_WLOCK(); 1140 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1141 dp->dad_ondadq = true; 1142 DADQ_WUNLOCK(); 1143 } 1144 1145 static void 1146 nd6_dad_del(struct dadq *dp) 1147 { 1148 1149 DADQ_WLOCK(); 1150 if (dp->dad_ondadq) { 1151 /* 1152 * Remove dp from the dadq and release the dadq's 1153 * reference. 1154 */ 1155 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1156 dp->dad_ondadq = false; 1157 DADQ_WUNLOCK(); 1158 nd6_dad_rele(dp); 1159 } else 1160 DADQ_WUNLOCK(); 1161 } 1162 1163 static struct dadq * 1164 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1165 { 1166 struct dadq *dp; 1167 1168 DADQ_RLOCK(); 1169 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1170 if (dp->dad_ifa != ifa) 1171 continue; 1172 /* 1173 * Skip if the nonce matches the received one. 1174 * +2 in the length is required because of type and 1175 * length fields are included in a header. 1176 */ 1177 if (n != NULL && 1178 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1179 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1180 ND_OPT_NONCE_LEN) == 0) { 1181 dp->dad_ns_lcount++; 1182 continue; 1183 } 1184 refcount_acquire(&dp->dad_refcnt); 1185 break; 1186 } 1187 DADQ_RUNLOCK(); 1188 1189 return (dp); 1190 } 1191 1192 static void 1193 nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns) 1194 { 1195 1196 if (send_ns != 0) 1197 nd6_dad_ns_output(dp); 1198 callout_reset(&dp->dad_timer_ch, ticks, 1199 (void (*)(void *))nd6_dad_timer, (void *)dp); 1200 } 1201 1202 static void 1203 nd6_dad_stoptimer(struct dadq *dp) 1204 { 1205 1206 callout_drain(&dp->dad_timer_ch); 1207 } 1208 1209 static void 1210 nd6_dad_rele(struct dadq *dp) 1211 { 1212 1213 if (refcount_release(&dp->dad_refcnt)) { 1214 ifa_free(dp->dad_ifa); 1215 free(dp, M_IP6NDP); 1216 } 1217 } 1218 1219 void 1220 nd6_dad_init(void) 1221 { 1222 1223 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1224 TAILQ_INIT(&V_dadq); 1225 } 1226 1227 /* 1228 * Start Duplicate Address Detection (DAD) for specified interface address. 1229 */ 1230 void 1231 nd6_dad_start(struct ifaddr *ifa, int delay) 1232 { 1233 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1234 struct dadq *dp; 1235 char ip6buf[INET6_ADDRSTRLEN]; 1236 1237 /* 1238 * If we don't need DAD, don't do it. 1239 * There are several cases: 1240 * - DAD is disabled (ip6_dad_count == 0) 1241 * - the interface address is anycast 1242 */ 1243 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1244 log(LOG_DEBUG, 1245 "nd6_dad_start: called with non-tentative address " 1246 "%s(%s)\n", 1247 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1248 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1249 return; 1250 } 1251 if (ia->ia6_flags & IN6_IFF_ANYCAST) { 1252 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1253 return; 1254 } 1255 if (!V_ip6_dad_count) { 1256 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1257 return; 1258 } 1259 if (ifa->ifa_ifp == NULL) 1260 panic("nd6_dad_start: ifa->ifa_ifp == NULL"); 1261 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) { 1262 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1263 return; 1264 } 1265 if (!(ifa->ifa_ifp->if_flags & IFF_UP) || 1266 !(ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) || 1267 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED)) { 1268 ia->ia6_flags |= IN6_IFF_TENTATIVE; 1269 return; 1270 } 1271 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1272 /* 1273 * DAD is already in progress. Let the existing entry 1274 * finish it. 1275 */ 1276 nd6_dad_rele(dp); 1277 return; 1278 } 1279 1280 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1281 if (dp == NULL) { 1282 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1283 "%s(%s)\n", 1284 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1285 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1286 return; 1287 } 1288 callout_init(&dp->dad_timer_ch, 0); 1289 #ifdef VIMAGE 1290 dp->dad_vnet = curvnet; 1291 #endif 1292 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1293 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1294 1295 /* 1296 * Send NS packet for DAD, ip6_dad_count times. 1297 * Note that we must delay the first transmission, if this is the 1298 * first packet to be sent from the interface after interface 1299 * (re)initialization. 1300 */ 1301 dp->dad_ifa = ifa; 1302 ifa_ref(dp->dad_ifa); 1303 dp->dad_count = V_ip6_dad_count; 1304 dp->dad_ns_icount = dp->dad_na_icount = 0; 1305 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1306 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1307 1308 /* Add this to the dadq and add a reference for the dadq. */ 1309 refcount_init(&dp->dad_refcnt, 1); 1310 nd6_dad_add(dp); 1311 nd6_dad_starttimer(dp, delay, 0); 1312 } 1313 1314 /* 1315 * terminate DAD unconditionally. used for address removals. 1316 */ 1317 void 1318 nd6_dad_stop(struct ifaddr *ifa) 1319 { 1320 struct dadq *dp; 1321 1322 dp = nd6_dad_find(ifa, NULL); 1323 if (!dp) { 1324 /* DAD wasn't started yet */ 1325 return; 1326 } 1327 1328 nd6_dad_stoptimer(dp); 1329 nd6_dad_del(dp); 1330 1331 /* Release this function's reference, acquired by nd6_dad_find(). */ 1332 nd6_dad_rele(dp); 1333 } 1334 1335 static void 1336 nd6_dad_timer(struct dadq *dp) 1337 { 1338 CURVNET_SET(dp->dad_vnet); 1339 struct ifaddr *ifa = dp->dad_ifa; 1340 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1341 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1342 char ip6buf[INET6_ADDRSTRLEN]; 1343 1344 /* Sanity check */ 1345 if (ia == NULL) { 1346 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n"); 1347 goto err; 1348 } 1349 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1350 /* Do not need DAD for ifdisabled interface. */ 1351 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1352 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1353 goto err; 1354 } 1355 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1356 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1357 "%s(%s)\n", 1358 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1359 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1360 goto err; 1361 } 1362 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1363 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1364 "%s(%s)\n", 1365 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1366 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1367 goto err; 1368 } 1369 1370 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1371 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1372 (((ifp->if_flags & IFF_UP) == 0) || 1373 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1374 nd6log((LOG_INFO, "%s: could not run DAD " 1375 "because the interface was down or not running.\n", 1376 if_name(ifa->ifa_ifp))); 1377 goto err; 1378 } 1379 1380 /* Need more checks? */ 1381 if (dp->dad_ns_ocount < dp->dad_count) { 1382 /* 1383 * We have more NS to go. Send NS packet for DAD. 1384 */ 1385 nd6_dad_starttimer(dp, 1386 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1); 1387 goto done; 1388 } else { 1389 /* 1390 * We have transmitted sufficient number of DAD packets. 1391 * See what we've got. 1392 */ 1393 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1394 /* We've seen NS or NA, means DAD has failed. */ 1395 nd6_dad_duplicated(ifa, dp); 1396 else if (V_dad_enhanced != 0 && 1397 dp->dad_ns_lcount > 0 && 1398 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1399 /* 1400 * Sec. 4.1 in RFC 7527 requires transmission of 1401 * additional probes until the loopback condition 1402 * becomes clear when a looped back probe is detected. 1403 */ 1404 log(LOG_ERR, "%s: a looped back NS message is " 1405 "detected during DAD for %s. " 1406 "Another DAD probes are being sent.\n", 1407 if_name(ifa->ifa_ifp), 1408 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1409 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1410 /* 1411 * Send an NS immediately and increase dad_count by 1412 * V_nd6_mmaxtries - 1. 1413 */ 1414 dp->dad_count = 1415 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1416 nd6_dad_starttimer(dp, 1417 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1418 1); 1419 goto done; 1420 } else { 1421 /* 1422 * We are done with DAD. No NA came, no NS came. 1423 * No duplicate address found. Check IFDISABLED flag 1424 * again in case that it is changed between the 1425 * beginning of this function and here. 1426 */ 1427 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1428 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1429 1430 nd6log((LOG_DEBUG, 1431 "%s: DAD complete for %s - no duplicates found\n", 1432 if_name(ifa->ifa_ifp), 1433 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1434 if (dp->dad_ns_lcount > 0) 1435 log(LOG_ERR, "%s: DAD completed while " 1436 "a looped back NS message is detected " 1437 "during DAD for %s.\n", 1438 if_name(ifa->ifa_ifp), 1439 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1440 } 1441 } 1442 err: 1443 nd6_dad_del(dp); 1444 done: 1445 CURVNET_RESTORE(); 1446 } 1447 1448 static void 1449 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1450 { 1451 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1452 struct ifnet *ifp; 1453 char ip6buf[INET6_ADDRSTRLEN]; 1454 1455 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1456 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1457 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1458 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1459 dp->dad_na_icount); 1460 1461 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1462 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1463 1464 ifp = ifa->ifa_ifp; 1465 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1466 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1467 log(LOG_ERR, "%s: manual intervention required\n", 1468 if_name(ifp)); 1469 1470 /* 1471 * If the address is a link-local address formed from an interface 1472 * identifier based on the hardware address which is supposed to be 1473 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1474 * operation on the interface SHOULD be disabled. 1475 * [RFC 4862, Section 5.4.5] 1476 */ 1477 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1478 struct in6_addr in6; 1479 1480 /* 1481 * To avoid over-reaction, we only apply this logic when we are 1482 * very sure that hardware addresses are supposed to be unique. 1483 */ 1484 switch (ifp->if_type) { 1485 case IFT_ETHER: 1486 case IFT_FDDI: 1487 case IFT_ATM: 1488 case IFT_IEEE1394: 1489 case IFT_IEEE80211: 1490 case IFT_INFINIBAND: 1491 in6 = ia->ia_addr.sin6_addr; 1492 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1493 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1494 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1495 log(LOG_ERR, "%s: possible hardware address " 1496 "duplication detected, disable IPv6\n", 1497 if_name(ifp)); 1498 } 1499 break; 1500 } 1501 } 1502 } 1503 1504 static void 1505 nd6_dad_ns_output(struct dadq *dp) 1506 { 1507 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1508 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1509 int i; 1510 1511 dp->dad_ns_tcount++; 1512 if ((ifp->if_flags & IFF_UP) == 0) { 1513 return; 1514 } 1515 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1516 return; 1517 } 1518 1519 dp->dad_ns_ocount++; 1520 if (V_dad_enhanced != 0) { 1521 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1522 dp->dad_nonce[i] = arc4random(); 1523 /* 1524 * XXXHRS: Note that in the case that 1525 * DupAddrDetectTransmits > 1, multiple NS messages with 1526 * different nonces can be looped back in an unexpected 1527 * order. The current implementation recognizes only 1528 * the latest nonce on the sender side. Practically it 1529 * should work well in almost all cases. 1530 */ 1531 } 1532 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1533 (uint8_t *)&dp->dad_nonce[0]); 1534 } 1535 1536 static void 1537 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1538 { 1539 struct in6_ifaddr *ia; 1540 struct ifnet *ifp; 1541 const struct in6_addr *taddr6; 1542 struct dadq *dp; 1543 1544 if (ifa == NULL) 1545 panic("ifa == NULL in nd6_dad_ns_input"); 1546 1547 ia = (struct in6_ifaddr *)ifa; 1548 ifp = ifa->ifa_ifp; 1549 taddr6 = &ia->ia_addr.sin6_addr; 1550 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1551 if (V_dad_enhanced == 0) 1552 ndopt_nonce = NULL; 1553 dp = nd6_dad_find(ifa, ndopt_nonce); 1554 if (dp == NULL) 1555 return; 1556 1557 dp->dad_ns_icount++; 1558 nd6_dad_rele(dp); 1559 } 1560 1561 static void 1562 nd6_dad_na_input(struct ifaddr *ifa) 1563 { 1564 struct dadq *dp; 1565 1566 if (ifa == NULL) 1567 panic("ifa == NULL in nd6_dad_na_input"); 1568 1569 dp = nd6_dad_find(ifa, NULL); 1570 if (dp != NULL) { 1571 dp->dad_na_icount++; 1572 nd6_dad_rele(dp); 1573 } 1574 }
Cache object: e3dbb9ef423b0a0b5e10404d55c6acd9
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