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sys/netinet6/nd6_nbr.c
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1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $ 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD: releng/12.0/sys/netinet6/nd6_nbr.c 336676 2018-07-24 16:35:52Z andrew $"); 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 #include "opt_ipsec.h" 40 #include "opt_mpath.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/malloc.h> 45 #include <sys/libkern.h> 46 #include <sys/lock.h> 47 #include <sys/rwlock.h> 48 #include <sys/mbuf.h> 49 #include <sys/socket.h> 50 #include <sys/sockio.h> 51 #include <sys/time.h> 52 #include <sys/kernel.h> 53 #include <sys/errno.h> 54 #include <sys/sysctl.h> 55 #include <sys/syslog.h> 56 #include <sys/queue.h> 57 #include <sys/callout.h> 58 #include <sys/refcount.h> 59 60 #include <net/if.h> 61 #include <net/if_types.h> 62 #include <net/if_dl.h> 63 #include <net/if_var.h> 64 #include <net/route.h> 65 #ifdef RADIX_MPATH 66 #include <net/radix_mpath.h> 67 #endif 68 #include <net/vnet.h> 69 70 #include <netinet/in.h> 71 #include <netinet/in_var.h> 72 #include <net/if_llatbl.h> 73 #include <netinet6/in6_var.h> 74 #include <netinet6/in6_ifattach.h> 75 #include <netinet/ip6.h> 76 #include <netinet6/ip6_var.h> 77 #include <netinet6/scope6_var.h> 78 #include <netinet6/nd6.h> 79 #include <netinet/icmp6.h> 80 #include <netinet/ip_carp.h> 81 #include <netinet6/send.h> 82 83 #define SDL(s) ((struct sockaddr_dl *)s) 84 85 struct dadq; 86 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *); 87 static void nd6_dad_add(struct dadq *dp); 88 static void nd6_dad_del(struct dadq *dp); 89 static void nd6_dad_rele(struct dadq *); 90 static void nd6_dad_starttimer(struct dadq *, int, int); 91 static void nd6_dad_stoptimer(struct dadq *); 92 static void nd6_dad_timer(struct dadq *); 93 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *); 94 static void nd6_dad_ns_output(struct dadq *); 95 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *); 96 static void nd6_dad_na_input(struct ifaddr *); 97 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 98 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 99 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *, 100 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int); 101 102 VNET_DEFINE_STATIC(int, dad_enhanced) = 1; 103 #define V_dad_enhanced VNET(dad_enhanced) 104 105 SYSCTL_DECL(_net_inet6_ip6); 106 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW, 107 &VNET_NAME(dad_enhanced), 0, 108 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD."); 109 110 VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to 111 transmit DAD packet */ 112 #define V_dad_maxtry VNET(dad_maxtry) 113 114 /* 115 * Input a Neighbor Solicitation Message. 116 * 117 * Based on RFC 2461 118 * Based on RFC 2462 (duplicate address detection) 119 */ 120 void 121 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 122 { 123 struct ifnet *ifp = m->m_pkthdr.rcvif; 124 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 125 struct nd_neighbor_solicit *nd_ns; 126 struct in6_addr saddr6 = ip6->ip6_src; 127 struct in6_addr daddr6 = ip6->ip6_dst; 128 struct in6_addr taddr6; 129 struct in6_addr myaddr6; 130 char *lladdr = NULL; 131 struct ifaddr *ifa = NULL; 132 int lladdrlen = 0; 133 int anycast = 0, proxy = 0, tentative = 0; 134 int tlladdr; 135 int rflag; 136 union nd_opts ndopts; 137 struct sockaddr_dl proxydl; 138 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 139 140 /* RFC 6980: Nodes MUST silently ignore fragments */ 141 if(m->m_flags & M_FRAGMENTED) 142 goto freeit; 143 144 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 145 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 146 rflag = 0; 147 #ifndef PULLDOWN_TEST 148 IP6_EXTHDR_CHECK(m, off, icmp6len,); 149 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 150 #else 151 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); 152 if (nd_ns == NULL) { 153 ICMP6STAT_INC(icp6s_tooshort); 154 return; 155 } 156 #endif 157 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ 158 taddr6 = nd_ns->nd_ns_target; 159 if (in6_setscope(&taddr6, ifp, NULL) != 0) 160 goto bad; 161 162 if (ip6->ip6_hlim != 255) { 163 nd6log((LOG_ERR, 164 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 165 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 166 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 167 goto bad; 168 } 169 170 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 171 /* dst has to be a solicited node multicast address. */ 172 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 173 /* don't check ifindex portion */ 174 daddr6.s6_addr32[1] == 0 && 175 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 176 daddr6.s6_addr8[12] == 0xff) { 177 ; /* good */ 178 } else { 179 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 180 "(wrong ip6 dst)\n")); 181 goto bad; 182 } 183 } else if (!V_nd6_onlink_ns_rfc4861) { 184 struct sockaddr_in6 src_sa6; 185 186 /* 187 * According to recent IETF discussions, it is not a good idea 188 * to accept a NS from an address which would not be deemed 189 * to be a neighbor otherwise. This point is expected to be 190 * clarified in future revisions of the specification. 191 */ 192 bzero(&src_sa6, sizeof(src_sa6)); 193 src_sa6.sin6_family = AF_INET6; 194 src_sa6.sin6_len = sizeof(src_sa6); 195 src_sa6.sin6_addr = saddr6; 196 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 197 nd6log((LOG_INFO, "nd6_ns_input: " 198 "NS packet from non-neighbor\n")); 199 goto bad; 200 } 201 } 202 203 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 204 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 205 goto bad; 206 } 207 208 icmp6len -= sizeof(*nd_ns); 209 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 210 if (nd6_options(&ndopts) < 0) { 211 nd6log((LOG_INFO, 212 "nd6_ns_input: invalid ND option, ignored\n")); 213 /* nd6_options have incremented stats */ 214 goto freeit; 215 } 216 217 if (ndopts.nd_opts_src_lladdr) { 218 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 219 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 220 } 221 222 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 223 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 224 "(link-layer address option)\n")); 225 goto bad; 226 } 227 228 /* 229 * Attaching target link-layer address to the NA? 230 * (RFC 2461 7.2.4) 231 * 232 * NS IP dst is unicast/anycast MUST NOT add 233 * NS IP dst is solicited-node multicast MUST add 234 * 235 * In implementation, we add target link-layer address by default. 236 * We do not add one in MUST NOT cases. 237 */ 238 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 239 tlladdr = 0; 240 else 241 tlladdr = 1; 242 243 /* 244 * Target address (taddr6) must be either: 245 * (1) Valid unicast/anycast address for my receiving interface, 246 * (2) Unicast address for which I'm offering proxy service, or 247 * (3) "tentative" address on which DAD is being performed. 248 */ 249 /* (1) and (3) check. */ 250 if (ifp->if_carp) 251 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 252 else 253 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 254 255 /* (2) check. */ 256 if (ifa == NULL) { 257 struct sockaddr_dl rt_gateway; 258 struct rt_addrinfo info; 259 struct sockaddr_in6 dst6; 260 261 bzero(&dst6, sizeof(dst6)); 262 dst6.sin6_len = sizeof(struct sockaddr_in6); 263 dst6.sin6_family = AF_INET6; 264 dst6.sin6_addr = taddr6; 265 266 bzero(&rt_gateway, sizeof(rt_gateway)); 267 rt_gateway.sdl_len = sizeof(rt_gateway); 268 bzero(&info, sizeof(info)); 269 info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway; 270 271 if (rib_lookup_info(ifp->if_fib, (struct sockaddr *)&dst6, 272 0, 0, &info) == 0) { 273 if ((info.rti_flags & RTF_ANNOUNCE) != 0 && 274 rt_gateway.sdl_family == AF_LINK) { 275 276 /* 277 * proxy NDP for single entry 278 */ 279 proxydl = *SDL(&rt_gateway); 280 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal( 281 ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 282 if (ifa) 283 proxy = 1; 284 } 285 } 286 } 287 if (ifa == NULL) { 288 /* 289 * We've got an NS packet, and we don't have that adddress 290 * assigned for us. We MUST silently ignore it. 291 * See RFC2461 7.2.3. 292 */ 293 goto freeit; 294 } 295 myaddr6 = *IFA_IN6(ifa); 296 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 297 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 298 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 299 goto freeit; 300 301 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 302 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 303 "(if %d, NS packet %d)\n", 304 ip6_sprintf(ip6bufs, &taddr6), 305 ifp->if_addrlen, lladdrlen - 2)); 306 goto bad; 307 } 308 309 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 310 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 311 ip6_sprintf(ip6bufs, &saddr6))); 312 goto freeit; 313 } 314 315 /* 316 * We have neighbor solicitation packet, with target address equals to 317 * one of my tentative address. 318 * 319 * src addr how to process? 320 * --- --- 321 * multicast of course, invalid (rejected in ip6_input) 322 * unicast somebody is doing address resolution -> ignore 323 * unspec dup address detection 324 * 325 * The processing is defined in RFC 2462. 326 */ 327 if (tentative) { 328 /* 329 * If source address is unspecified address, it is for 330 * duplicate address detection. 331 * 332 * If not, the packet is for addess resolution; 333 * silently ignore it. 334 */ 335 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 336 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 337 338 goto freeit; 339 } 340 341 /* 342 * If the source address is unspecified address, entries must not 343 * be created or updated. 344 * It looks that sender is performing DAD. Output NA toward 345 * all-node multicast address, to tell the sender that I'm using 346 * the address. 347 * S bit ("solicited") must be zero. 348 */ 349 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 350 struct in6_addr in6_all; 351 352 in6_all = in6addr_linklocal_allnodes; 353 if (in6_setscope(&in6_all, ifp, NULL) != 0) 354 goto bad; 355 nd6_na_output_fib(ifp, &in6_all, &taddr6, 356 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 357 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 358 M_GETFIB(m)); 359 goto freeit; 360 } 361 362 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 363 ND_NEIGHBOR_SOLICIT, 0); 364 365 nd6_na_output_fib(ifp, &saddr6, &taddr6, 366 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 367 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 368 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 369 freeit: 370 if (ifa != NULL) 371 ifa_free(ifa); 372 m_freem(m); 373 return; 374 375 bad: 376 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 377 ip6_sprintf(ip6bufs, &saddr6))); 378 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 379 ip6_sprintf(ip6bufs, &daddr6))); 380 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 381 ip6_sprintf(ip6bufs, &taddr6))); 382 ICMP6STAT_INC(icp6s_badns); 383 if (ifa != NULL) 384 ifa_free(ifa); 385 m_freem(m); 386 } 387 388 /* 389 * Output a Neighbor Solicitation Message. Caller specifies: 390 * - ICMP6 header source IP6 address 391 * - ND6 header target IP6 address 392 * - ND6 header source datalink address 393 * 394 * Based on RFC 2461 395 * Based on RFC 2462 (duplicate address detection) 396 * 397 * ln - for source address determination 398 * nonce - If non-NULL, NS is used for duplicate address detection and 399 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 400 */ 401 static void 402 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 403 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 404 uint8_t *nonce, u_int fibnum) 405 { 406 struct mbuf *m; 407 struct m_tag *mtag; 408 struct ip6_hdr *ip6; 409 struct nd_neighbor_solicit *nd_ns; 410 struct ip6_moptions im6o; 411 int icmp6len; 412 int maxlen; 413 caddr_t mac; 414 415 if (IN6_IS_ADDR_MULTICAST(taddr6)) 416 return; 417 418 /* estimate the size of message */ 419 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 420 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 421 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 422 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 423 __func__, max_linkhdr, maxlen, MCLBYTES)); 424 425 if (max_linkhdr + maxlen > MHLEN) 426 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 427 else 428 m = m_gethdr(M_NOWAIT, MT_DATA); 429 if (m == NULL) 430 return; 431 M_SETFIB(m, fibnum); 432 433 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 434 m->m_flags |= M_MCAST; 435 im6o.im6o_multicast_ifp = ifp; 436 im6o.im6o_multicast_hlim = 255; 437 im6o.im6o_multicast_loop = 0; 438 } 439 440 icmp6len = sizeof(*nd_ns); 441 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 442 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 443 444 /* fill neighbor solicitation packet */ 445 ip6 = mtod(m, struct ip6_hdr *); 446 ip6->ip6_flow = 0; 447 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 448 ip6->ip6_vfc |= IPV6_VERSION; 449 /* ip6->ip6_plen will be set later */ 450 ip6->ip6_nxt = IPPROTO_ICMPV6; 451 ip6->ip6_hlim = 255; 452 if (daddr6) 453 ip6->ip6_dst = *daddr6; 454 else { 455 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 456 ip6->ip6_dst.s6_addr16[1] = 0; 457 ip6->ip6_dst.s6_addr32[1] = 0; 458 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 459 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 460 ip6->ip6_dst.s6_addr8[12] = 0xff; 461 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 462 goto bad; 463 } 464 if (nonce == NULL) { 465 struct ifaddr *ifa = NULL; 466 467 /* 468 * RFC2461 7.2.2: 469 * "If the source address of the packet prompting the 470 * solicitation is the same as one of the addresses assigned 471 * to the outgoing interface, that address SHOULD be placed 472 * in the IP Source Address of the outgoing solicitation. 473 * Otherwise, any one of the addresses assigned to the 474 * interface should be used." 475 * 476 * We use the source address for the prompting packet 477 * (saddr6), if saddr6 belongs to the outgoing interface. 478 * Otherwise, we perform the source address selection as usual. 479 */ 480 481 if (saddr6 != NULL) 482 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 483 if (ifa != NULL) { 484 /* ip6_src set already. */ 485 ip6->ip6_src = *saddr6; 486 ifa_free(ifa); 487 } else { 488 int error; 489 struct in6_addr dst6, src6; 490 uint32_t scopeid; 491 492 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); 493 error = in6_selectsrc_addr(fibnum, &dst6, 494 scopeid, ifp, &src6, NULL); 495 if (error) { 496 char ip6buf[INET6_ADDRSTRLEN]; 497 nd6log((LOG_DEBUG, "%s: source can't be " 498 "determined: dst=%s, error=%d\n", __func__, 499 ip6_sprintf(ip6buf, &dst6), 500 error)); 501 goto bad; 502 } 503 ip6->ip6_src = src6; 504 } 505 } else { 506 /* 507 * Source address for DAD packet must always be IPv6 508 * unspecified address. (0::0) 509 * We actually don't have to 0-clear the address (we did it 510 * above), but we do so here explicitly to make the intention 511 * clearer. 512 */ 513 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 514 } 515 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 516 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 517 nd_ns->nd_ns_code = 0; 518 nd_ns->nd_ns_reserved = 0; 519 nd_ns->nd_ns_target = *taddr6; 520 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 521 522 /* 523 * Add source link-layer address option. 524 * 525 * spec implementation 526 * --- --- 527 * DAD packet MUST NOT do not add the option 528 * there's no link layer address: 529 * impossible do not add the option 530 * there's link layer address: 531 * Multicast NS MUST add one add the option 532 * Unicast NS SHOULD add one add the option 533 */ 534 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 535 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 536 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 537 /* 8 byte alignments... */ 538 optlen = (optlen + 7) & ~7; 539 540 m->m_pkthdr.len += optlen; 541 m->m_len += optlen; 542 icmp6len += optlen; 543 bzero((caddr_t)nd_opt, optlen); 544 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 545 nd_opt->nd_opt_len = optlen >> 3; 546 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 547 } 548 /* 549 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 550 * This behavior is documented as Enhanced Duplicate Address 551 * Detection in RFC 7527. 552 * net.inet6.ip6.dad_enhanced=0 disables this. 553 */ 554 if (V_dad_enhanced != 0 && nonce != NULL) { 555 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 556 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 557 /* 8-byte alignment is required. */ 558 optlen = (optlen + 7) & ~7; 559 560 m->m_pkthdr.len += optlen; 561 m->m_len += optlen; 562 icmp6len += optlen; 563 bzero((caddr_t)nd_opt, optlen); 564 nd_opt->nd_opt_type = ND_OPT_NONCE; 565 nd_opt->nd_opt_len = optlen >> 3; 566 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 567 } 568 ip6->ip6_plen = htons((u_short)icmp6len); 569 nd_ns->nd_ns_cksum = 0; 570 nd_ns->nd_ns_cksum = 571 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 572 573 if (send_sendso_input_hook != NULL) { 574 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 575 sizeof(unsigned short), M_NOWAIT); 576 if (mtag == NULL) 577 goto bad; 578 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 579 m_tag_prepend(m, mtag); 580 } 581 582 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 583 &im6o, NULL, NULL); 584 icmp6_ifstat_inc(ifp, ifs6_out_msg); 585 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 586 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 587 588 return; 589 590 bad: 591 m_freem(m); 592 } 593 594 #ifndef BURN_BRIDGES 595 void 596 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 597 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 598 { 599 600 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 601 } 602 #endif 603 /* 604 * Neighbor advertisement input handling. 605 * 606 * Based on RFC 2461 607 * Based on RFC 2462 (duplicate address detection) 608 * 609 * the following items are not implemented yet: 610 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 611 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 612 */ 613 void 614 nd6_na_input(struct mbuf *m, int off, int icmp6len) 615 { 616 struct ifnet *ifp = m->m_pkthdr.rcvif; 617 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 618 struct nd_neighbor_advert *nd_na; 619 struct in6_addr daddr6 = ip6->ip6_dst; 620 struct in6_addr taddr6; 621 int flags; 622 int is_router; 623 int is_solicited; 624 int is_override; 625 char *lladdr = NULL; 626 int lladdrlen = 0; 627 int checklink = 0; 628 struct ifaddr *ifa; 629 struct llentry *ln = NULL; 630 union nd_opts ndopts; 631 struct mbuf *chain = NULL; 632 struct sockaddr_in6 sin6; 633 u_char linkhdr[LLE_MAX_LINKHDR]; 634 size_t linkhdrsize; 635 int lladdr_off; 636 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 637 638 /* RFC 6980: Nodes MUST silently ignore fragments */ 639 if(m->m_flags & M_FRAGMENTED) 640 goto freeit; 641 642 if (ip6->ip6_hlim != 255) { 643 nd6log((LOG_ERR, 644 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 645 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 646 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 647 goto bad; 648 } 649 650 #ifndef PULLDOWN_TEST 651 IP6_EXTHDR_CHECK(m, off, icmp6len,); 652 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 653 #else 654 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 655 if (nd_na == NULL) { 656 ICMP6STAT_INC(icp6s_tooshort); 657 return; 658 } 659 #endif 660 661 flags = nd_na->nd_na_flags_reserved; 662 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 663 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 664 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 665 memset(&sin6, 0, sizeof(sin6)); 666 667 taddr6 = nd_na->nd_na_target; 668 if (in6_setscope(&taddr6, ifp, NULL)) 669 goto bad; /* XXX: impossible */ 670 671 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 672 nd6log((LOG_ERR, 673 "nd6_na_input: invalid target address %s\n", 674 ip6_sprintf(ip6bufs, &taddr6))); 675 goto bad; 676 } 677 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 678 if (is_solicited) { 679 nd6log((LOG_ERR, 680 "nd6_na_input: a solicited adv is multicasted\n")); 681 goto bad; 682 } 683 684 icmp6len -= sizeof(*nd_na); 685 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 686 if (nd6_options(&ndopts) < 0) { 687 nd6log((LOG_INFO, 688 "nd6_na_input: invalid ND option, ignored\n")); 689 /* nd6_options have incremented stats */ 690 goto freeit; 691 } 692 693 if (ndopts.nd_opts_tgt_lladdr) { 694 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 695 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 696 } 697 698 /* 699 * This effectively disables the DAD check on a non-master CARP 700 * address. 701 */ 702 if (ifp->if_carp) 703 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 704 else 705 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 706 707 /* 708 * Target address matches one of my interface address. 709 * 710 * If my address is tentative, this means that there's somebody 711 * already using the same address as mine. This indicates DAD failure. 712 * This is defined in RFC 2462. 713 * 714 * Otherwise, process as defined in RFC 2461. 715 */ 716 if (ifa 717 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 718 nd6_dad_na_input(ifa); 719 ifa_free(ifa); 720 goto freeit; 721 } 722 723 /* Just for safety, maybe unnecessary. */ 724 if (ifa) { 725 ifa_free(ifa); 726 log(LOG_ERR, 727 "nd6_na_input: duplicate IP6 address %s\n", 728 ip6_sprintf(ip6bufs, &taddr6)); 729 goto freeit; 730 } 731 732 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 733 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 734 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 735 ifp->if_addrlen, lladdrlen - 2)); 736 goto bad; 737 } 738 739 /* 740 * If no neighbor cache entry is found, NA SHOULD silently be 741 * discarded. 742 */ 743 IF_AFDATA_RLOCK(ifp); 744 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 745 IF_AFDATA_RUNLOCK(ifp); 746 if (ln == NULL) { 747 goto freeit; 748 } 749 750 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 751 /* 752 * If the link-layer has address, and no lladdr option came, 753 * discard the packet. 754 */ 755 if (ifp->if_addrlen && lladdr == NULL) { 756 goto freeit; 757 } 758 759 /* 760 * Record link-layer address, and update the state. 761 */ 762 linkhdrsize = sizeof(linkhdr); 763 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 764 linkhdr, &linkhdrsize, &lladdr_off) != 0) 765 return; 766 767 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize, 768 lladdr_off) == 0) { 769 ln = NULL; 770 goto freeit; 771 } 772 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 773 if (is_solicited) 774 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 775 else 776 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 777 if ((ln->ln_router = is_router) != 0) { 778 /* 779 * This means a router's state has changed from 780 * non-reachable to probably reachable, and might 781 * affect the status of associated prefixes.. 782 */ 783 checklink = 1; 784 } 785 } else { 786 int llchange; 787 788 /* 789 * Check if the link-layer address has changed or not. 790 */ 791 if (lladdr == NULL) 792 llchange = 0; 793 else { 794 if (ln->la_flags & LLE_VALID) { 795 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 796 llchange = 1; 797 else 798 llchange = 0; 799 } else 800 llchange = 1; 801 } 802 803 /* 804 * This is VERY complex. Look at it with care. 805 * 806 * override solicit lladdr llchange action 807 * (L: record lladdr) 808 * 809 * 0 0 n -- (2c) 810 * 0 0 y n (2b) L 811 * 0 0 y y (1) REACHABLE->STALE 812 * 0 1 n -- (2c) *->REACHABLE 813 * 0 1 y n (2b) L *->REACHABLE 814 * 0 1 y y (1) REACHABLE->STALE 815 * 1 0 n -- (2a) 816 * 1 0 y n (2a) L 817 * 1 0 y y (2a) L *->STALE 818 * 1 1 n -- (2a) *->REACHABLE 819 * 1 1 y n (2a) L *->REACHABLE 820 * 1 1 y y (2a) L *->REACHABLE 821 */ 822 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 823 /* 824 * If state is REACHABLE, make it STALE. 825 * no other updates should be done. 826 */ 827 if (ln->ln_state == ND6_LLINFO_REACHABLE) 828 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 829 goto freeit; 830 } else if (is_override /* (2a) */ 831 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 832 || lladdr == NULL) { /* (2c) */ 833 /* 834 * Update link-local address, if any. 835 */ 836 if (lladdr != NULL) { 837 linkhdrsize = sizeof(linkhdr); 838 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 839 linkhdr, &linkhdrsize, &lladdr_off) != 0) 840 goto freeit; 841 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 842 linkhdrsize, lladdr_off) == 0) { 843 ln = NULL; 844 goto freeit; 845 } 846 EVENTHANDLER_INVOKE(lle_event, ln, 847 LLENTRY_RESOLVED); 848 } 849 850 /* 851 * If solicited, make the state REACHABLE. 852 * If not solicited and the link-layer address was 853 * changed, make it STALE. 854 */ 855 if (is_solicited) 856 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 857 else { 858 if (lladdr != NULL && llchange) 859 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 860 } 861 } 862 863 if (ln->ln_router && !is_router) { 864 /* 865 * The peer dropped the router flag. 866 * Remove the sender from the Default Router List and 867 * update the Destination Cache entries. 868 */ 869 struct ifnet *nd6_ifp; 870 871 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 872 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 873 (ND_IFINFO(nd6_ifp)->flags & 874 ND6_IFF_ACCEPT_RTADV) != 0) 875 /* 876 * Even if the neighbor is not in the default 877 * router list, the neighbor may be used as a 878 * next hop for some destinations (e.g. redirect 879 * case). So we must call rt6_flush explicitly. 880 */ 881 rt6_flush(&ip6->ip6_src, ifp); 882 } 883 ln->ln_router = is_router; 884 } 885 /* XXX - QL 886 * Does this matter? 887 * rt->rt_flags &= ~RTF_REJECT; 888 */ 889 ln->la_asked = 0; 890 if (ln->la_hold != NULL) 891 nd6_grab_holdchain(ln, &chain, &sin6); 892 freeit: 893 if (ln != NULL) 894 LLE_WUNLOCK(ln); 895 896 if (chain != NULL) 897 nd6_flush_holdchain(ifp, chain, &sin6); 898 899 if (checklink) 900 pfxlist_onlink_check(); 901 902 m_freem(m); 903 return; 904 905 bad: 906 if (ln != NULL) 907 LLE_WUNLOCK(ln); 908 909 ICMP6STAT_INC(icp6s_badna); 910 m_freem(m); 911 } 912 913 /* 914 * Neighbor advertisement output handling. 915 * 916 * Based on RFC 2461 917 * 918 * the following items are not implemented yet: 919 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 920 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 921 * 922 * tlladdr - 1 if include target link-layer address 923 * sdl0 - sockaddr_dl (= proxy NA) or NULL 924 */ 925 static void 926 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 927 const struct in6_addr *taddr6, u_long flags, int tlladdr, 928 struct sockaddr *sdl0, u_int fibnum) 929 { 930 struct mbuf *m; 931 struct m_tag *mtag; 932 struct ip6_hdr *ip6; 933 struct nd_neighbor_advert *nd_na; 934 struct ip6_moptions im6o; 935 struct in6_addr daddr6, dst6, src6; 936 uint32_t scopeid; 937 938 int icmp6len, maxlen, error; 939 caddr_t mac = NULL; 940 941 daddr6 = *daddr6_0; /* make a local copy for modification */ 942 943 /* estimate the size of message */ 944 maxlen = sizeof(*ip6) + sizeof(*nd_na); 945 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 946 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 947 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 948 __func__, max_linkhdr, maxlen, MCLBYTES)); 949 950 if (max_linkhdr + maxlen > MHLEN) 951 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 952 else 953 m = m_gethdr(M_NOWAIT, MT_DATA); 954 if (m == NULL) 955 return; 956 M_SETFIB(m, fibnum); 957 958 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 959 m->m_flags |= M_MCAST; 960 im6o.im6o_multicast_ifp = ifp; 961 im6o.im6o_multicast_hlim = 255; 962 im6o.im6o_multicast_loop = 0; 963 } 964 965 icmp6len = sizeof(*nd_na); 966 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 967 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 968 969 /* fill neighbor advertisement packet */ 970 ip6 = mtod(m, struct ip6_hdr *); 971 ip6->ip6_flow = 0; 972 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 973 ip6->ip6_vfc |= IPV6_VERSION; 974 ip6->ip6_nxt = IPPROTO_ICMPV6; 975 ip6->ip6_hlim = 255; 976 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 977 /* reply to DAD */ 978 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 979 daddr6.s6_addr16[1] = 0; 980 daddr6.s6_addr32[1] = 0; 981 daddr6.s6_addr32[2] = 0; 982 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 983 if (in6_setscope(&daddr6, ifp, NULL)) 984 goto bad; 985 986 flags &= ~ND_NA_FLAG_SOLICITED; 987 } 988 ip6->ip6_dst = daddr6; 989 990 /* 991 * Select a source whose scope is the same as that of the dest. 992 */ 993 in6_splitscope(&daddr6, &dst6, &scopeid); 994 error = in6_selectsrc_addr(fibnum, &dst6, 995 scopeid, ifp, &src6, NULL); 996 if (error) { 997 char ip6buf[INET6_ADDRSTRLEN]; 998 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 999 "determined: dst=%s, error=%d\n", 1000 ip6_sprintf(ip6buf, &daddr6), error)); 1001 goto bad; 1002 } 1003 ip6->ip6_src = src6; 1004 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1005 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1006 nd_na->nd_na_code = 0; 1007 nd_na->nd_na_target = *taddr6; 1008 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1009 1010 /* 1011 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1012 * see nd6_ns_input() for details. 1013 * Basically, if NS packet is sent to unicast/anycast addr, 1014 * target lladdr option SHOULD NOT be included. 1015 */ 1016 if (tlladdr) { 1017 /* 1018 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1019 * lladdr in sdl0. If we are not proxying (sending NA for 1020 * my address) use lladdr configured for the interface. 1021 */ 1022 if (sdl0 == NULL) { 1023 if (ifp->if_carp) 1024 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1025 if (mac == NULL) 1026 mac = nd6_ifptomac(ifp); 1027 } else if (sdl0->sa_family == AF_LINK) { 1028 struct sockaddr_dl *sdl; 1029 sdl = (struct sockaddr_dl *)sdl0; 1030 if (sdl->sdl_alen == ifp->if_addrlen) 1031 mac = LLADDR(sdl); 1032 } 1033 } 1034 if (tlladdr && mac) { 1035 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1036 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1037 1038 /* roundup to 8 bytes alignment! */ 1039 optlen = (optlen + 7) & ~7; 1040 1041 m->m_pkthdr.len += optlen; 1042 m->m_len += optlen; 1043 icmp6len += optlen; 1044 bzero((caddr_t)nd_opt, optlen); 1045 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1046 nd_opt->nd_opt_len = optlen >> 3; 1047 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1048 } else 1049 flags &= ~ND_NA_FLAG_OVERRIDE; 1050 1051 ip6->ip6_plen = htons((u_short)icmp6len); 1052 nd_na->nd_na_flags_reserved = flags; 1053 nd_na->nd_na_cksum = 0; 1054 nd_na->nd_na_cksum = 1055 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1056 1057 if (send_sendso_input_hook != NULL) { 1058 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1059 sizeof(unsigned short), M_NOWAIT); 1060 if (mtag == NULL) 1061 goto bad; 1062 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1063 m_tag_prepend(m, mtag); 1064 } 1065 1066 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1067 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1068 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1069 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1070 1071 return; 1072 1073 bad: 1074 m_freem(m); 1075 } 1076 1077 #ifndef BURN_BRIDGES 1078 void 1079 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1080 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1081 struct sockaddr *sdl0) 1082 { 1083 1084 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1085 RT_DEFAULT_FIB); 1086 } 1087 #endif 1088 1089 caddr_t 1090 nd6_ifptomac(struct ifnet *ifp) 1091 { 1092 switch (ifp->if_type) { 1093 case IFT_ETHER: 1094 case IFT_IEEE1394: 1095 case IFT_L2VLAN: 1096 case IFT_INFINIBAND: 1097 case IFT_BRIDGE: 1098 return IF_LLADDR(ifp); 1099 default: 1100 return NULL; 1101 } 1102 } 1103 1104 struct dadq { 1105 TAILQ_ENTRY(dadq) dad_list; 1106 struct ifaddr *dad_ifa; 1107 int dad_count; /* max NS to send */ 1108 int dad_ns_tcount; /* # of trials to send NS */ 1109 int dad_ns_ocount; /* NS sent so far */ 1110 int dad_ns_icount; 1111 int dad_na_icount; 1112 int dad_ns_lcount; /* looped back NS */ 1113 int dad_loopbackprobe; /* probing state for loopback detection */ 1114 struct callout dad_timer_ch; 1115 struct vnet *dad_vnet; 1116 u_int dad_refcnt; 1117 #define ND_OPT_NONCE_LEN32 \ 1118 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1119 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1120 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */ 1121 }; 1122 1123 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq); 1124 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock); 1125 #define V_dadq VNET(dadq) 1126 #define V_dad_rwlock VNET(dad_rwlock) 1127 1128 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1129 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1130 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1131 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1132 1133 static void 1134 nd6_dad_add(struct dadq *dp) 1135 { 1136 1137 DADQ_WLOCK(); 1138 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1139 dp->dad_ondadq = true; 1140 DADQ_WUNLOCK(); 1141 } 1142 1143 static void 1144 nd6_dad_del(struct dadq *dp) 1145 { 1146 1147 DADQ_WLOCK(); 1148 if (dp->dad_ondadq) { 1149 /* 1150 * Remove dp from the dadq and release the dadq's 1151 * reference. 1152 */ 1153 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1154 dp->dad_ondadq = false; 1155 DADQ_WUNLOCK(); 1156 nd6_dad_rele(dp); 1157 } else 1158 DADQ_WUNLOCK(); 1159 } 1160 1161 static struct dadq * 1162 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1163 { 1164 struct dadq *dp; 1165 1166 DADQ_RLOCK(); 1167 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1168 if (dp->dad_ifa != ifa) 1169 continue; 1170 /* 1171 * Skip if the nonce matches the received one. 1172 * +2 in the length is required because of type and 1173 * length fields are included in a header. 1174 */ 1175 if (n != NULL && 1176 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1177 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1178 ND_OPT_NONCE_LEN) == 0) { 1179 dp->dad_ns_lcount++; 1180 continue; 1181 } 1182 refcount_acquire(&dp->dad_refcnt); 1183 break; 1184 } 1185 DADQ_RUNLOCK(); 1186 1187 return (dp); 1188 } 1189 1190 static void 1191 nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns) 1192 { 1193 1194 if (send_ns != 0) 1195 nd6_dad_ns_output(dp); 1196 callout_reset(&dp->dad_timer_ch, ticks, 1197 (void (*)(void *))nd6_dad_timer, (void *)dp); 1198 } 1199 1200 static void 1201 nd6_dad_stoptimer(struct dadq *dp) 1202 { 1203 1204 callout_drain(&dp->dad_timer_ch); 1205 } 1206 1207 static void 1208 nd6_dad_rele(struct dadq *dp) 1209 { 1210 1211 if (refcount_release(&dp->dad_refcnt)) { 1212 ifa_free(dp->dad_ifa); 1213 free(dp, M_IP6NDP); 1214 } 1215 } 1216 1217 void 1218 nd6_dad_init(void) 1219 { 1220 1221 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1222 TAILQ_INIT(&V_dadq); 1223 } 1224 1225 /* 1226 * Start Duplicate Address Detection (DAD) for specified interface address. 1227 */ 1228 void 1229 nd6_dad_start(struct ifaddr *ifa, int delay) 1230 { 1231 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1232 struct dadq *dp; 1233 char ip6buf[INET6_ADDRSTRLEN]; 1234 1235 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0, 1236 ("starting DAD on non-tentative address %p", ifa)); 1237 1238 /* 1239 * If we don't need DAD, don't do it. 1240 * There are several cases: 1241 * - DAD is disabled globally or on the interface 1242 * - the interface address is anycast 1243 */ 1244 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 || 1245 V_ip6_dad_count == 0 || 1246 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) != 0) { 1247 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1248 return; 1249 } 1250 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 || 1251 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || 1252 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) != 0) 1253 return; 1254 1255 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1256 /* 1257 * DAD is already in progress. Let the existing entry 1258 * finish it. 1259 */ 1260 nd6_dad_rele(dp); 1261 return; 1262 } 1263 1264 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1265 if (dp == NULL) { 1266 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1267 "%s(%s)\n", 1268 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1269 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1270 return; 1271 } 1272 callout_init(&dp->dad_timer_ch, 0); 1273 #ifdef VIMAGE 1274 dp->dad_vnet = curvnet; 1275 #endif 1276 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1277 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1278 1279 /* 1280 * Send NS packet for DAD, ip6_dad_count times. 1281 * Note that we must delay the first transmission, if this is the 1282 * first packet to be sent from the interface after interface 1283 * (re)initialization. 1284 */ 1285 dp->dad_ifa = ifa; 1286 ifa_ref(dp->dad_ifa); 1287 dp->dad_count = V_ip6_dad_count; 1288 dp->dad_ns_icount = dp->dad_na_icount = 0; 1289 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1290 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1291 1292 /* Add this to the dadq and add a reference for the dadq. */ 1293 refcount_init(&dp->dad_refcnt, 1); 1294 nd6_dad_add(dp); 1295 nd6_dad_starttimer(dp, delay, 0); 1296 } 1297 1298 /* 1299 * terminate DAD unconditionally. used for address removals. 1300 */ 1301 void 1302 nd6_dad_stop(struct ifaddr *ifa) 1303 { 1304 struct dadq *dp; 1305 1306 dp = nd6_dad_find(ifa, NULL); 1307 if (!dp) { 1308 /* DAD wasn't started yet */ 1309 return; 1310 } 1311 1312 nd6_dad_stoptimer(dp); 1313 nd6_dad_del(dp); 1314 1315 /* Release this function's reference, acquired by nd6_dad_find(). */ 1316 nd6_dad_rele(dp); 1317 } 1318 1319 static void 1320 nd6_dad_timer(struct dadq *dp) 1321 { 1322 CURVNET_SET(dp->dad_vnet); 1323 struct ifaddr *ifa = dp->dad_ifa; 1324 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1325 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1326 char ip6buf[INET6_ADDRSTRLEN]; 1327 1328 KASSERT(ia != NULL, ("DAD entry %p with no address", dp)); 1329 1330 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1331 /* Do not need DAD for ifdisabled interface. */ 1332 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1333 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1334 goto err; 1335 } 1336 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1337 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1338 "%s(%s)\n", 1339 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1340 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1341 goto err; 1342 } 1343 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1344 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1345 "%s(%s)\n", 1346 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1347 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1348 goto err; 1349 } 1350 1351 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1352 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1353 (((ifp->if_flags & IFF_UP) == 0) || 1354 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1355 nd6log((LOG_INFO, "%s: could not run DAD " 1356 "because the interface was down or not running.\n", 1357 if_name(ifa->ifa_ifp))); 1358 goto err; 1359 } 1360 1361 /* Need more checks? */ 1362 if (dp->dad_ns_ocount < dp->dad_count) { 1363 /* 1364 * We have more NS to go. Send NS packet for DAD. 1365 */ 1366 nd6_dad_starttimer(dp, 1367 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1); 1368 goto done; 1369 } else { 1370 /* 1371 * We have transmitted sufficient number of DAD packets. 1372 * See what we've got. 1373 */ 1374 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1375 /* We've seen NS or NA, means DAD has failed. */ 1376 nd6_dad_duplicated(ifa, dp); 1377 else if (V_dad_enhanced != 0 && 1378 dp->dad_ns_lcount > 0 && 1379 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1380 /* 1381 * Sec. 4.1 in RFC 7527 requires transmission of 1382 * additional probes until the loopback condition 1383 * becomes clear when a looped back probe is detected. 1384 */ 1385 log(LOG_ERR, "%s: a looped back NS message is " 1386 "detected during DAD for %s. " 1387 "Another DAD probes are being sent.\n", 1388 if_name(ifa->ifa_ifp), 1389 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1390 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1391 /* 1392 * Send an NS immediately and increase dad_count by 1393 * V_nd6_mmaxtries - 1. 1394 */ 1395 dp->dad_count = 1396 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1397 nd6_dad_starttimer(dp, 1398 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1399 1); 1400 goto done; 1401 } else { 1402 /* 1403 * We are done with DAD. No NA came, no NS came. 1404 * No duplicate address found. Check IFDISABLED flag 1405 * again in case that it is changed between the 1406 * beginning of this function and here. 1407 */ 1408 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1409 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1410 1411 nd6log((LOG_DEBUG, 1412 "%s: DAD complete for %s - no duplicates found\n", 1413 if_name(ifa->ifa_ifp), 1414 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1415 if (dp->dad_ns_lcount > 0) 1416 log(LOG_ERR, "%s: DAD completed while " 1417 "a looped back NS message is detected " 1418 "during DAD for %s.\n", 1419 if_name(ifa->ifa_ifp), 1420 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1421 } 1422 } 1423 err: 1424 nd6_dad_del(dp); 1425 done: 1426 CURVNET_RESTORE(); 1427 } 1428 1429 static void 1430 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1431 { 1432 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1433 struct ifnet *ifp; 1434 char ip6buf[INET6_ADDRSTRLEN]; 1435 1436 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1437 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1438 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1439 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1440 dp->dad_na_icount); 1441 1442 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1443 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1444 1445 ifp = ifa->ifa_ifp; 1446 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1447 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1448 log(LOG_ERR, "%s: manual intervention required\n", 1449 if_name(ifp)); 1450 1451 /* 1452 * If the address is a link-local address formed from an interface 1453 * identifier based on the hardware address which is supposed to be 1454 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1455 * operation on the interface SHOULD be disabled. 1456 * [RFC 4862, Section 5.4.5] 1457 */ 1458 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1459 struct in6_addr in6; 1460 1461 /* 1462 * To avoid over-reaction, we only apply this logic when we are 1463 * very sure that hardware addresses are supposed to be unique. 1464 */ 1465 switch (ifp->if_type) { 1466 case IFT_ETHER: 1467 case IFT_ATM: 1468 case IFT_IEEE1394: 1469 case IFT_INFINIBAND: 1470 in6 = ia->ia_addr.sin6_addr; 1471 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1472 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1473 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1474 log(LOG_ERR, "%s: possible hardware address " 1475 "duplication detected, disable IPv6\n", 1476 if_name(ifp)); 1477 } 1478 break; 1479 } 1480 } 1481 } 1482 1483 static void 1484 nd6_dad_ns_output(struct dadq *dp) 1485 { 1486 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1487 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1488 int i; 1489 1490 dp->dad_ns_tcount++; 1491 if ((ifp->if_flags & IFF_UP) == 0) { 1492 return; 1493 } 1494 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1495 return; 1496 } 1497 1498 dp->dad_ns_ocount++; 1499 if (V_dad_enhanced != 0) { 1500 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1501 dp->dad_nonce[i] = arc4random(); 1502 /* 1503 * XXXHRS: Note that in the case that 1504 * DupAddrDetectTransmits > 1, multiple NS messages with 1505 * different nonces can be looped back in an unexpected 1506 * order. The current implementation recognizes only 1507 * the latest nonce on the sender side. Practically it 1508 * should work well in almost all cases. 1509 */ 1510 } 1511 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1512 (uint8_t *)&dp->dad_nonce[0]); 1513 } 1514 1515 static void 1516 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1517 { 1518 struct dadq *dp; 1519 1520 if (ifa == NULL) 1521 panic("ifa == NULL in nd6_dad_ns_input"); 1522 1523 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1524 if (V_dad_enhanced == 0) 1525 ndopt_nonce = NULL; 1526 dp = nd6_dad_find(ifa, ndopt_nonce); 1527 if (dp == NULL) 1528 return; 1529 1530 dp->dad_ns_icount++; 1531 nd6_dad_rele(dp); 1532 } 1533 1534 static void 1535 nd6_dad_na_input(struct ifaddr *ifa) 1536 { 1537 struct dadq *dp; 1538 1539 if (ifa == NULL) 1540 panic("ifa == NULL in nd6_dad_na_input"); 1541 1542 dp = nd6_dad_find(ifa, NULL); 1543 if (dp != NULL) { 1544 dp->dad_na_icount++; 1545 nd6_dad_rele(dp); 1546 } 1547 }
Cache object: c43b07927624c744fb87a880ac8613c0
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