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: stable/11/sys/netinet6/nd6_nbr.c 359803 2020-04-11 09:36:41Z ae $"); 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 83struct dadq; 84static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *); 85static void nd6_dad_add(struct dadq *dp); 86static void nd6_dad_del(struct dadq *dp); 87static void nd6_dad_rele(struct dadq *); 88static void nd6_dad_starttimer(struct dadq *, int, int); 89static void nd6_dad_stoptimer(struct dadq *); 90static void nd6_dad_timer(struct dadq *); 91static void nd6_dad_duplicated(struct ifaddr *, struct dadq *); 92static void nd6_dad_ns_output(struct dadq *); 93static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *); 94static void nd6_dad_na_input(struct ifaddr *); 95static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 96 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 97static 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 100static VNET_DEFINE(int, dad_enhanced) = 1; 101#define V_dad_enhanced VNET(dad_enhanced) 102 103SYSCTL_DECL(_net_inet6_ip6); 104SYSCTL_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 108static 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 */ 118void 119nd6_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 */ 399static void 400nd6_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 593void 594nd6_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 */ 611void 612nd6_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 /* 749 * Do not try to override static entry. 750 */ 751 if (ln->la_flags & LLE_STATIC) 752 goto freeit; 753 754 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 755 /* 756 * If the link-layer has address, and no lladdr option came, 757 * discard the packet. 758 */ 759 if (ifp->if_addrlen && lladdr == NULL) { 760 goto freeit; 761 } 762 763 /* 764 * Record link-layer address, and update the state. 765 */ 766 linkhdrsize = sizeof(linkhdr); 767 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 768 linkhdr, &linkhdrsize, &lladdr_off) != 0) 769 return; 770 771 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize, 772 lladdr_off) == 0) { 773 ln = NULL; 774 goto freeit; 775 } 776 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 777 if (is_solicited) 778 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 779 else 780 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 781 if ((ln->ln_router = is_router) != 0) { 782 /* 783 * This means a router's state has changed from 784 * non-reachable to probably reachable, and might 785 * affect the status of associated prefixes.. 786 */ 787 checklink = 1; 788 } 789 } else { 790 int llchange; 791 792 /* 793 * Check if the link-layer address has changed or not. 794 */ 795 if (lladdr == NULL) 796 llchange = 0; 797 else { 798 if (ln->la_flags & LLE_VALID) { 799 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 800 llchange = 1; 801 else 802 llchange = 0; 803 } else 804 llchange = 1; 805 } 806 807 /* 808 * This is VERY complex. Look at it with care. 809 * 810 * override solicit lladdr llchange action 811 * (L: record lladdr) 812 * 813 * 0 0 n -- (2c) 814 * 0 0 y n (2b) L 815 * 0 0 y y (1) REACHABLE->STALE 816 * 0 1 n -- (2c) *->REACHABLE 817 * 0 1 y n (2b) L *->REACHABLE 818 * 0 1 y y (1) REACHABLE->STALE 819 * 1 0 n -- (2a) 820 * 1 0 y n (2a) L 821 * 1 0 y y (2a) L *->STALE 822 * 1 1 n -- (2a) *->REACHABLE 823 * 1 1 y n (2a) L *->REACHABLE 824 * 1 1 y y (2a) L *->REACHABLE 825 */ 826 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 827 /* 828 * If state is REACHABLE, make it STALE. 829 * no other updates should be done. 830 */ 831 if (ln->ln_state == ND6_LLINFO_REACHABLE) 832 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 833 goto freeit; 834 } else if (is_override /* (2a) */ 835 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 836 || lladdr == NULL) { /* (2c) */ 837 /* 838 * Update link-local address, if any. 839 */ 840 if (lladdr != NULL) { 841 linkhdrsize = sizeof(linkhdr); 842 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 843 linkhdr, &linkhdrsize, &lladdr_off) != 0) 844 goto freeit; 845 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 846 linkhdrsize, lladdr_off) == 0) { 847 ln = NULL; 848 goto freeit; 849 } 850 EVENTHANDLER_INVOKE(lle_event, ln, 851 LLENTRY_RESOLVED); 852 } 853 854 /* 855 * If solicited, make the state REACHABLE. 856 * If not solicited and the link-layer address was 857 * changed, make it STALE. 858 */ 859 if (is_solicited) 860 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 861 else { 862 if (lladdr != NULL && llchange) 863 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 864 } 865 } 866 867 if (ln->ln_router && !is_router) { 868 /* 869 * The peer dropped the router flag. 870 * Remove the sender from the Default Router List and 871 * update the Destination Cache entries. 872 */ 873 struct ifnet *nd6_ifp; 874 875 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 876 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) && 877 (ND_IFINFO(nd6_ifp)->flags & 878 ND6_IFF_ACCEPT_RTADV) != 0) 879 /* 880 * Even if the neighbor is not in the default 881 * router list, the neighbor may be used as a 882 * next hop for some destinations (e.g. redirect 883 * case). So we must call rt6_flush explicitly. 884 */ 885 rt6_flush(&ip6->ip6_src, ifp); 886 } 887 ln->ln_router = is_router; 888 } 889 /* XXX - QL 890 * Does this matter? 891 * rt->rt_flags &= ~RTF_REJECT; 892 */ 893 ln->la_asked = 0; 894 if (ln->la_hold != NULL) 895 nd6_grab_holdchain(ln, &chain, &sin6); 896 freeit: 897 if (ln != NULL) 898 LLE_WUNLOCK(ln); 899 900 if (chain != NULL) 901 nd6_flush_holdchain(ifp, ifp, chain, &sin6); 902 903 if (checklink) 904 pfxlist_onlink_check(); 905 906 m_freem(m); 907 return; 908 909 bad: 910 if (ln != NULL) 911 LLE_WUNLOCK(ln); 912 913 ICMP6STAT_INC(icp6s_badna); 914 m_freem(m); 915} 916 917/* 918 * Neighbor advertisement output handling. 919 * 920 * Based on RFC 2461 921 * 922 * the following items are not implemented yet: 923 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 924 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 925 * 926 * tlladdr - 1 if include target link-layer address 927 * sdl0 - sockaddr_dl (= proxy NA) or NULL 928 */ 929static void 930nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 931 const struct in6_addr *taddr6, u_long flags, int tlladdr, 932 struct sockaddr *sdl0, u_int fibnum) 933{ 934 struct mbuf *m; 935 struct m_tag *mtag; 936 struct ip6_hdr *ip6; 937 struct nd_neighbor_advert *nd_na; 938 struct ip6_moptions im6o; 939 struct in6_addr daddr6, dst6, src6; 940 uint32_t scopeid; 941 942 int icmp6len, maxlen, error; 943 caddr_t mac = NULL; 944 945 daddr6 = *daddr6_0; /* make a local copy for modification */ 946 947 /* estimate the size of message */ 948 maxlen = sizeof(*ip6) + sizeof(*nd_na); 949 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 950 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 951 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 952 __func__, max_linkhdr, maxlen, MCLBYTES)); 953 954 if (max_linkhdr + maxlen > MHLEN) 955 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 956 else 957 m = m_gethdr(M_NOWAIT, MT_DATA); 958 if (m == NULL) 959 return; 960 M_SETFIB(m, fibnum); 961 962 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 963 m->m_flags |= M_MCAST; 964 im6o.im6o_multicast_ifp = ifp; 965 im6o.im6o_multicast_hlim = 255; 966 im6o.im6o_multicast_loop = 0; 967 } 968 969 icmp6len = sizeof(*nd_na); 970 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 971 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 972 973 /* fill neighbor advertisement packet */ 974 ip6 = mtod(m, struct ip6_hdr *); 975 ip6->ip6_flow = 0; 976 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 977 ip6->ip6_vfc |= IPV6_VERSION; 978 ip6->ip6_nxt = IPPROTO_ICMPV6; 979 ip6->ip6_hlim = 255; 980 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 981 /* reply to DAD */ 982 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 983 daddr6.s6_addr16[1] = 0; 984 daddr6.s6_addr32[1] = 0; 985 daddr6.s6_addr32[2] = 0; 986 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 987 if (in6_setscope(&daddr6, ifp, NULL)) 988 goto bad; 989 990 flags &= ~ND_NA_FLAG_SOLICITED; 991 } 992 ip6->ip6_dst = daddr6; 993 994 /* 995 * Select a source whose scope is the same as that of the dest. 996 */ 997 in6_splitscope(&daddr6, &dst6, &scopeid); 998 error = in6_selectsrc_addr(fibnum, &dst6, 999 scopeid, ifp, &src6, NULL); 1000 if (error) { 1001 char ip6buf[INET6_ADDRSTRLEN]; 1002 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1003 "determined: dst=%s, error=%d\n", 1004 ip6_sprintf(ip6buf, &daddr6), error)); 1005 goto bad; 1006 } 1007 ip6->ip6_src = src6; 1008 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1009 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1010 nd_na->nd_na_code = 0; 1011 nd_na->nd_na_target = *taddr6; 1012 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1013 1014 /* 1015 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1016 * see nd6_ns_input() for details. 1017 * Basically, if NS packet is sent to unicast/anycast addr, 1018 * target lladdr option SHOULD NOT be included. 1019 */ 1020 if (tlladdr) { 1021 /* 1022 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1023 * lladdr in sdl0. If we are not proxying (sending NA for 1024 * my address) use lladdr configured for the interface. 1025 */ 1026 if (sdl0 == NULL) { 1027 if (ifp->if_carp) 1028 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1029 if (mac == NULL) 1030 mac = nd6_ifptomac(ifp); 1031 } else if (sdl0->sa_family == AF_LINK) { 1032 struct sockaddr_dl *sdl; 1033 sdl = (struct sockaddr_dl *)sdl0; 1034 if (sdl->sdl_alen == ifp->if_addrlen) 1035 mac = LLADDR(sdl); 1036 } 1037 } 1038 if (tlladdr && mac) { 1039 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1040 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1041 1042 /* roundup to 8 bytes alignment! */ 1043 optlen = (optlen + 7) & ~7; 1044 1045 m->m_pkthdr.len += optlen; 1046 m->m_len += optlen; 1047 icmp6len += optlen; 1048 bzero((caddr_t)nd_opt, optlen); 1049 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1050 nd_opt->nd_opt_len = optlen >> 3; 1051 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1052 } else 1053 flags &= ~ND_NA_FLAG_OVERRIDE; 1054 1055 ip6->ip6_plen = htons((u_short)icmp6len); 1056 nd_na->nd_na_flags_reserved = flags; 1057 nd_na->nd_na_cksum = 0; 1058 nd_na->nd_na_cksum = 1059 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1060 1061 if (send_sendso_input_hook != NULL) { 1062 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1063 sizeof(unsigned short), M_NOWAIT); 1064 if (mtag == NULL) 1065 goto bad; 1066 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1067 m_tag_prepend(m, mtag); 1068 } 1069 1070 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1071 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1072 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1073 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1074 1075 return; 1076 1077 bad: 1078 m_freem(m); 1079} 1080 1081#ifndef BURN_BRIDGES 1082void 1083nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1084 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1085 struct sockaddr *sdl0) 1086{ 1087 1088 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1089 RT_DEFAULT_FIB); 1090} 1091#endif 1092 1093caddr_t 1094nd6_ifptomac(struct ifnet *ifp) 1095{ 1096 switch (ifp->if_type) { 1097 case IFT_ARCNET: 1098 case IFT_ETHER: 1099 case IFT_FDDI: 1100 case IFT_IEEE1394: 1101 case IFT_L2VLAN: 1102 case IFT_IEEE80211: 1103 case IFT_INFINIBAND: 1104 case IFT_BRIDGE: 1105 case IFT_ISO88025: 1106 return IF_LLADDR(ifp); 1107 default: 1108 return NULL; 1109 } 1110} 1111 1112struct dadq { 1113 TAILQ_ENTRY(dadq) dad_list; 1114 struct ifaddr *dad_ifa; 1115 int dad_count; /* max NS to send */ 1116 int dad_ns_tcount; /* # of trials to send NS */ 1117 int dad_ns_ocount; /* NS sent so far */ 1118 int dad_ns_icount; 1119 int dad_na_icount; 1120 int dad_ns_lcount; /* looped back NS */ 1121 int dad_loopbackprobe; /* probing state for loopback detection */ 1122 struct callout dad_timer_ch; 1123 struct vnet *dad_vnet; 1124 u_int dad_refcnt; 1125#define ND_OPT_NONCE_LEN32 \ 1126 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1127 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1128 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */ 1129}; 1130 1131static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq); 1132static VNET_DEFINE(struct rwlock, dad_rwlock); 1133#define V_dadq VNET(dadq) 1134#define V_dad_rwlock VNET(dad_rwlock) 1135 1136#define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1137#define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1138#define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1139#define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1140 1141static void 1142nd6_dad_add(struct dadq *dp) 1143{ 1144 1145 DADQ_WLOCK(); 1146 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1147 dp->dad_ondadq = true; 1148 DADQ_WUNLOCK(); 1149} 1150 1151static void 1152nd6_dad_del(struct dadq *dp) 1153{ 1154 1155 DADQ_WLOCK(); 1156 if (dp->dad_ondadq) { 1157 /* 1158 * Remove dp from the dadq and release the dadq's 1159 * reference. 1160 */ 1161 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1162 dp->dad_ondadq = false; 1163 DADQ_WUNLOCK(); 1164 nd6_dad_rele(dp); 1165 } else 1166 DADQ_WUNLOCK(); 1167} 1168 1169static struct dadq * 1170nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1171{ 1172 struct dadq *dp; 1173 1174 DADQ_RLOCK(); 1175 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1176 if (dp->dad_ifa != ifa) 1177 continue; 1178 /* 1179 * Skip if the nonce matches the received one. 1180 * +2 in the length is required because of type and 1181 * length fields are included in a header. 1182 */ 1183 if (n != NULL && 1184 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1185 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1186 ND_OPT_NONCE_LEN) == 0) { 1187 dp->dad_ns_lcount++; 1188 continue; 1189 } 1190 refcount_acquire(&dp->dad_refcnt); 1191 break; 1192 } 1193 DADQ_RUNLOCK(); 1194 1195 return (dp); 1196} 1197 1198static void 1199nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns) 1200{ 1201 1202 if (send_ns != 0) 1203 nd6_dad_ns_output(dp); 1204 callout_reset(&dp->dad_timer_ch, ticks, 1205 (void (*)(void *))nd6_dad_timer, (void *)dp); 1206} 1207 1208static void 1209nd6_dad_stoptimer(struct dadq *dp) 1210{ 1211 1212 callout_drain(&dp->dad_timer_ch); 1213} 1214 1215static void 1216nd6_dad_rele(struct dadq *dp) 1217{ 1218 1219 if (refcount_release(&dp->dad_refcnt)) { 1220 ifa_free(dp->dad_ifa); 1221 free(dp, M_IP6NDP); 1222 } 1223} 1224 1225void 1226nd6_dad_init(void) 1227{ 1228 1229 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1230 TAILQ_INIT(&V_dadq); 1231} 1232 1233/* 1234 * Start Duplicate Address Detection (DAD) for specified interface address. 1235 */ 1236void 1237nd6_dad_start(struct ifaddr *ifa, int delay) 1238{ 1239 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1240 struct dadq *dp; 1241 char ip6buf[INET6_ADDRSTRLEN]; 1242 1243 /* 1244 * If we don't need DAD, don't do it. 1245 * There are several cases: 1246 * - DAD is disabled (ip6_dad_count == 0) 1247 * - the interface address is anycast 1248 */ 1249 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1250 log(LOG_DEBUG, 1251 "nd6_dad_start: called with non-tentative address " 1252 "%s(%s)\n", 1253 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1254 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1255 return; 1256 } 1257 if (ia->ia6_flags & IN6_IFF_ANYCAST) { 1258 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1259 return; 1260 } 1261 if (!V_ip6_dad_count) { 1262 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1263 return; 1264 } 1265 if (ifa->ifa_ifp == NULL) 1266 panic("nd6_dad_start: ifa->ifa_ifp == NULL"); 1267 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) { 1268 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1269 return; 1270 } 1271 if (!(ifa->ifa_ifp->if_flags & IFF_UP) || 1272 !(ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) || 1273 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED)) { 1274 ia->ia6_flags |= IN6_IFF_TENTATIVE; 1275 return; 1276 } 1277 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1278 /* 1279 * DAD is already in progress. Let the existing entry 1280 * finish it. 1281 */ 1282 nd6_dad_rele(dp); 1283 return; 1284 } 1285 1286 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1287 if (dp == NULL) { 1288 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1289 "%s(%s)\n", 1290 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1291 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1292 return; 1293 } 1294 callout_init(&dp->dad_timer_ch, 0); 1295#ifdef VIMAGE 1296 dp->dad_vnet = curvnet; 1297#endif 1298 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1299 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1300 1301 /* 1302 * Send NS packet for DAD, ip6_dad_count times. 1303 * Note that we must delay the first transmission, if this is the 1304 * first packet to be sent from the interface after interface 1305 * (re)initialization. 1306 */ 1307 dp->dad_ifa = ifa; 1308 ifa_ref(dp->dad_ifa); 1309 dp->dad_count = V_ip6_dad_count; 1310 dp->dad_ns_icount = dp->dad_na_icount = 0; 1311 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1312 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1313 1314 /* Add this to the dadq and add a reference for the dadq. */ 1315 refcount_init(&dp->dad_refcnt, 1); 1316 nd6_dad_add(dp); 1317 nd6_dad_starttimer(dp, delay, 0); 1318} 1319 1320/* 1321 * terminate DAD unconditionally. used for address removals. 1322 */ 1323void 1324nd6_dad_stop(struct ifaddr *ifa) 1325{ 1326 struct dadq *dp; 1327 1328 dp = nd6_dad_find(ifa, NULL); 1329 if (!dp) { 1330 /* DAD wasn't started yet */ 1331 return; 1332 } 1333 1334 nd6_dad_stoptimer(dp); 1335 nd6_dad_del(dp); 1336 1337 /* Release this function's reference, acquired by nd6_dad_find(). */ 1338 nd6_dad_rele(dp); 1339} 1340 1341static void 1342nd6_dad_timer(struct dadq *dp) 1343{ 1344 CURVNET_SET(dp->dad_vnet); 1345 struct ifaddr *ifa = dp->dad_ifa; 1346 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1347 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1348 char ip6buf[INET6_ADDRSTRLEN]; 1349 1350 /* Sanity check */ 1351 if (ia == NULL) { 1352 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n"); 1353 goto err; 1354 } 1355 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1356 /* Do not need DAD for ifdisabled interface. */ 1357 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1358 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1359 goto err; 1360 } 1361 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1362 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1363 "%s(%s)\n", 1364 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1365 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1366 goto err; 1367 } 1368 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1369 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1370 "%s(%s)\n", 1371 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1372 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1373 goto err; 1374 } 1375 1376 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1377 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1378 (((ifp->if_flags & IFF_UP) == 0) || 1379 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1380 nd6log((LOG_INFO, "%s: could not run DAD " 1381 "because the interface was down or not running.\n", 1382 if_name(ifa->ifa_ifp))); 1383 goto err; 1384 } 1385 1386 /* Need more checks? */ 1387 if (dp->dad_ns_ocount < dp->dad_count) { 1388 /* 1389 * We have more NS to go. Send NS packet for DAD. 1390 */ 1391 nd6_dad_starttimer(dp, 1392 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1); 1393 goto done; 1394 } else { 1395 /* 1396 * We have transmitted sufficient number of DAD packets. 1397 * See what we've got. 1398 */ 1399 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1400 /* We've seen NS or NA, means DAD has failed. */ 1401 nd6_dad_duplicated(ifa, dp); 1402 else if (V_dad_enhanced != 0 && 1403 dp->dad_ns_lcount > 0 && 1404 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1405 /* 1406 * Sec. 4.1 in RFC 7527 requires transmission of 1407 * additional probes until the loopback condition 1408 * becomes clear when a looped back probe is detected. 1409 */ 1410 log(LOG_ERR, "%s: a looped back NS message is " 1411 "detected during DAD for %s. " 1412 "Another DAD probes are being sent.\n", 1413 if_name(ifa->ifa_ifp), 1414 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1415 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1416 /* 1417 * Send an NS immediately and increase dad_count by 1418 * V_nd6_mmaxtries - 1. 1419 */ 1420 dp->dad_count = 1421 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1422 nd6_dad_starttimer(dp, 1423 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1424 1); 1425 goto done; 1426 } else { 1427 /* 1428 * We are done with DAD. No NA came, no NS came. 1429 * No duplicate address found. Check IFDISABLED flag 1430 * again in case that it is changed between the 1431 * beginning of this function and here. 1432 */ 1433 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1434 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1435 1436 nd6log((LOG_DEBUG, 1437 "%s: DAD complete for %s - no duplicates found\n", 1438 if_name(ifa->ifa_ifp), 1439 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1440 if (dp->dad_ns_lcount > 0) 1441 log(LOG_ERR, "%s: DAD completed while " 1442 "a looped back NS message is detected " 1443 "during DAD for %s.\n", 1444 if_name(ifa->ifa_ifp), 1445 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1446 } 1447 } 1448err: 1449 nd6_dad_del(dp); 1450done: 1451 CURVNET_RESTORE(); 1452} 1453 1454static void 1455nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1456{ 1457 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1458 struct ifnet *ifp; 1459 char ip6buf[INET6_ADDRSTRLEN]; 1460 1461 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1462 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1463 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1464 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1465 dp->dad_na_icount); 1466 1467 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1468 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1469 1470 ifp = ifa->ifa_ifp; 1471 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1472 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1473 log(LOG_ERR, "%s: manual intervention required\n", 1474 if_name(ifp)); 1475 1476 /* 1477 * If the address is a link-local address formed from an interface 1478 * identifier based on the hardware address which is supposed to be 1479 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1480 * operation on the interface SHOULD be disabled. 1481 * [RFC 4862, Section 5.4.5] 1482 */ 1483 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1484 struct in6_addr in6; 1485 1486 /* 1487 * To avoid over-reaction, we only apply this logic when we are 1488 * very sure that hardware addresses are supposed to be unique. 1489 */ 1490 switch (ifp->if_type) { 1491 case IFT_ETHER: 1492 case IFT_FDDI: 1493 case IFT_ATM: 1494 case IFT_IEEE1394: 1495 case IFT_IEEE80211: 1496 case IFT_INFINIBAND: 1497 in6 = ia->ia_addr.sin6_addr; 1498 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1499 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1500 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1501 log(LOG_ERR, "%s: possible hardware address " 1502 "duplication detected, disable IPv6\n", 1503 if_name(ifp)); 1504 } 1505 break; 1506 } 1507 } 1508} 1509 1510static void 1511nd6_dad_ns_output(struct dadq *dp) 1512{ 1513 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1514 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1515 int i; 1516 1517 dp->dad_ns_tcount++; 1518 if ((ifp->if_flags & IFF_UP) == 0) { 1519 return; 1520 } 1521 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1522 return; 1523 } 1524 1525 dp->dad_ns_ocount++; 1526 if (V_dad_enhanced != 0) { 1527 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1528 dp->dad_nonce[i] = arc4random(); 1529 /* 1530 * XXXHRS: Note that in the case that 1531 * DupAddrDetectTransmits > 1, multiple NS messages with 1532 * different nonces can be looped back in an unexpected 1533 * order. The current implementation recognizes only 1534 * the latest nonce on the sender side. Practically it 1535 * should work well in almost all cases. 1536 */ 1537 } 1538 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1539 (uint8_t *)&dp->dad_nonce[0]); 1540} 1541 1542static void 1543nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1544{ 1545 struct in6_ifaddr *ia; 1546 struct ifnet *ifp; 1547 const struct in6_addr *taddr6; 1548 struct dadq *dp; 1549 1550 if (ifa == NULL) 1551 panic("ifa == NULL in nd6_dad_ns_input"); 1552 1553 ia = (struct in6_ifaddr *)ifa; 1554 ifp = ifa->ifa_ifp; 1555 taddr6 = &ia->ia_addr.sin6_addr; 1556 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1557 if (V_dad_enhanced == 0) 1558 ndopt_nonce = NULL; 1559 dp = nd6_dad_find(ifa, ndopt_nonce); 1560 if (dp == NULL) 1561 return; 1562 1563 dp->dad_ns_icount++; 1564 nd6_dad_rele(dp); 1565} 1566 1567static void 1568nd6_dad_na_input(struct ifaddr *ifa) 1569{ 1570 struct dadq *dp; 1571 1572 if (ifa == NULL) 1573 panic("ifa == NULL in nd6_dad_na_input"); 1574 1575 dp = nd6_dad_find(ifa, NULL); 1576 if (dp != NULL) { 1577 dp->dad_na_icount++; 1578 nd6_dad_rele(dp); 1579 } 1580} 1581