nd6_nbr.c revision 293633
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: head/sys/netinet6/nd6_nbr.c 293633 2016-01-10 13:40:29Z melifaro $"); 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 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 139 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 140 rflag = 0; 141#ifndef PULLDOWN_TEST 142 IP6_EXTHDR_CHECK(m, off, icmp6len,); 143 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 144#else 145 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); 146 if (nd_ns == NULL) { 147 ICMP6STAT_INC(icp6s_tooshort); 148 return; 149 } 150#endif 151 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ 152 taddr6 = nd_ns->nd_ns_target; 153 if (in6_setscope(&taddr6, ifp, NULL) != 0) 154 goto bad; 155 156 if (ip6->ip6_hlim != 255) { 157 nd6log((LOG_ERR, 158 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 159 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 160 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 161 goto bad; 162 } 163 164 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 165 /* dst has to be a solicited node multicast address. */ 166 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 167 /* don't check ifindex portion */ 168 daddr6.s6_addr32[1] == 0 && 169 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 170 daddr6.s6_addr8[12] == 0xff) { 171 ; /* good */ 172 } else { 173 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 174 "(wrong ip6 dst)\n")); 175 goto bad; 176 } 177 } else if (!V_nd6_onlink_ns_rfc4861) { 178 struct sockaddr_in6 src_sa6; 179 180 /* 181 * According to recent IETF discussions, it is not a good idea 182 * to accept a NS from an address which would not be deemed 183 * to be a neighbor otherwise. This point is expected to be 184 * clarified in future revisions of the specification. 185 */ 186 bzero(&src_sa6, sizeof(src_sa6)); 187 src_sa6.sin6_family = AF_INET6; 188 src_sa6.sin6_len = sizeof(src_sa6); 189 src_sa6.sin6_addr = saddr6; 190 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 191 nd6log((LOG_INFO, "nd6_ns_input: " 192 "NS packet from non-neighbor\n")); 193 goto bad; 194 } 195 } 196 197 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 198 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 199 goto bad; 200 } 201 202 icmp6len -= sizeof(*nd_ns); 203 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 204 if (nd6_options(&ndopts) < 0) { 205 nd6log((LOG_INFO, 206 "nd6_ns_input: invalid ND option, ignored\n")); 207 /* nd6_options have incremented stats */ 208 goto freeit; 209 } 210 211 if (ndopts.nd_opts_src_lladdr) { 212 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 213 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 214 } 215 216 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 217 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 218 "(link-layer address option)\n")); 219 goto bad; 220 } 221 222 /* 223 * Attaching target link-layer address to the NA? 224 * (RFC 2461 7.2.4) 225 * 226 * NS IP dst is unicast/anycast MUST NOT add 227 * NS IP dst is solicited-node multicast MUST add 228 * 229 * In implementation, we add target link-layer address by default. 230 * We do not add one in MUST NOT cases. 231 */ 232 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 233 tlladdr = 0; 234 else 235 tlladdr = 1; 236 237 /* 238 * Target address (taddr6) must be either: 239 * (1) Valid unicast/anycast address for my receiving interface, 240 * (2) Unicast address for which I'm offering proxy service, or 241 * (3) "tentative" address on which DAD is being performed. 242 */ 243 /* (1) and (3) check. */ 244 if (ifp->if_carp) 245 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 246 else 247 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 248 249 /* (2) check. */ 250 if (ifa == NULL) { 251 struct sockaddr_dl rt_gateway; 252 struct rt_addrinfo info; 253 struct sockaddr_in6 dst6; 254 255 bzero(&dst6, sizeof(dst6)); 256 dst6.sin6_len = sizeof(struct sockaddr_in6); 257 dst6.sin6_family = AF_INET6; 258 dst6.sin6_addr = taddr6; 259 260 bzero(&rt_gateway, sizeof(rt_gateway)); 261 rt_gateway.sdl_len = sizeof(rt_gateway); 262 bzero(&info, sizeof(info)); 263 info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway; 264 265 /* Always use the default FIB. */ 266 if (rib_lookup_info(RT_DEFAULT_FIB, (struct sockaddr *)&dst6, 267 0, 0, &info) == 0) { 268 if ((info.rti_flags & RTF_ANNOUNCE) != 0 && 269 rt_gateway.sdl_family == AF_LINK) { 270 271 /* 272 * proxy NDP for single entry 273 */ 274 proxydl = *SDL(&rt_gateway); 275 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal( 276 ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 277 if (ifa) 278 proxy = 1; 279 } 280 } 281 } 282 if (ifa == NULL) { 283 /* 284 * We've got an NS packet, and we don't have that adddress 285 * assigned for us. We MUST silently ignore it. 286 * See RFC2461 7.2.3. 287 */ 288 goto freeit; 289 } 290 myaddr6 = *IFA_IN6(ifa); 291 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 292 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 293 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 294 goto freeit; 295 296 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 297 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 298 "(if %d, NS packet %d)\n", 299 ip6_sprintf(ip6bufs, &taddr6), 300 ifp->if_addrlen, lladdrlen - 2)); 301 goto bad; 302 } 303 304 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 305 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 306 ip6_sprintf(ip6bufs, &saddr6))); 307 goto freeit; 308 } 309 310 /* 311 * We have neighbor solicitation packet, with target address equals to 312 * one of my tentative address. 313 * 314 * src addr how to process? 315 * --- --- 316 * multicast of course, invalid (rejected in ip6_input) 317 * unicast somebody is doing address resolution -> ignore 318 * unspec dup address detection 319 * 320 * The processing is defined in RFC 2462. 321 */ 322 if (tentative) { 323 /* 324 * If source address is unspecified address, it is for 325 * duplicate address detection. 326 * 327 * If not, the packet is for addess resolution; 328 * silently ignore it. 329 */ 330 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 331 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 332 333 goto freeit; 334 } 335 336 /* 337 * If the source address is unspecified address, entries must not 338 * be created or updated. 339 * It looks that sender is performing DAD. Output NA toward 340 * all-node multicast address, to tell the sender that I'm using 341 * the address. 342 * S bit ("solicited") must be zero. 343 */ 344 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 345 struct in6_addr in6_all; 346 347 in6_all = in6addr_linklocal_allnodes; 348 if (in6_setscope(&in6_all, ifp, NULL) != 0) 349 goto bad; 350 nd6_na_output_fib(ifp, &in6_all, &taddr6, 351 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 352 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 353 M_GETFIB(m)); 354 goto freeit; 355 } 356 357 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 358 ND_NEIGHBOR_SOLICIT, 0); 359 360 nd6_na_output_fib(ifp, &saddr6, &taddr6, 361 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 362 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 363 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 364 freeit: 365 if (ifa != NULL) 366 ifa_free(ifa); 367 m_freem(m); 368 return; 369 370 bad: 371 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 372 ip6_sprintf(ip6bufs, &saddr6))); 373 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 374 ip6_sprintf(ip6bufs, &daddr6))); 375 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 376 ip6_sprintf(ip6bufs, &taddr6))); 377 ICMP6STAT_INC(icp6s_badns); 378 if (ifa != NULL) 379 ifa_free(ifa); 380 m_freem(m); 381} 382 383/* 384 * Output a Neighbor Solicitation Message. Caller specifies: 385 * - ICMP6 header source IP6 address 386 * - ND6 header target IP6 address 387 * - ND6 header source datalink address 388 * 389 * Based on RFC 2461 390 * Based on RFC 2462 (duplicate address detection) 391 * 392 * ln - for source address determination 393 * nonce - If non-NULL, NS is used for duplicate address detection and 394 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 395 */ 396static void 397nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6, 398 const struct in6_addr *daddr6, const struct in6_addr *taddr6, 399 uint8_t *nonce, u_int fibnum) 400{ 401 struct mbuf *m; 402 struct m_tag *mtag; 403 struct ip6_hdr *ip6; 404 struct nd_neighbor_solicit *nd_ns; 405 struct ip6_moptions im6o; 406 int icmp6len; 407 int maxlen; 408 caddr_t mac; 409 410 if (IN6_IS_ADDR_MULTICAST(taddr6)) 411 return; 412 413 /* estimate the size of message */ 414 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 415 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 416 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 417 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 418 __func__, max_linkhdr, maxlen, MCLBYTES)); 419 420 if (max_linkhdr + maxlen > MHLEN) 421 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 422 else 423 m = m_gethdr(M_NOWAIT, MT_DATA); 424 if (m == NULL) 425 return; 426 M_SETFIB(m, fibnum); 427 428 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 429 m->m_flags |= M_MCAST; 430 im6o.im6o_multicast_ifp = ifp; 431 im6o.im6o_multicast_hlim = 255; 432 im6o.im6o_multicast_loop = 0; 433 } 434 435 icmp6len = sizeof(*nd_ns); 436 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 437 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 438 439 /* fill neighbor solicitation packet */ 440 ip6 = mtod(m, struct ip6_hdr *); 441 ip6->ip6_flow = 0; 442 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 443 ip6->ip6_vfc |= IPV6_VERSION; 444 /* ip6->ip6_plen will be set later */ 445 ip6->ip6_nxt = IPPROTO_ICMPV6; 446 ip6->ip6_hlim = 255; 447 if (daddr6) 448 ip6->ip6_dst = *daddr6; 449 else { 450 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 451 ip6->ip6_dst.s6_addr16[1] = 0; 452 ip6->ip6_dst.s6_addr32[1] = 0; 453 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 454 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 455 ip6->ip6_dst.s6_addr8[12] = 0xff; 456 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 457 goto bad; 458 } 459 if (nonce == NULL) { 460 struct ifaddr *ifa = NULL; 461 462 /* 463 * RFC2461 7.2.2: 464 * "If the source address of the packet prompting the 465 * solicitation is the same as one of the addresses assigned 466 * to the outgoing interface, that address SHOULD be placed 467 * in the IP Source Address of the outgoing solicitation. 468 * Otherwise, any one of the addresses assigned to the 469 * interface should be used." 470 * 471 * We use the source address for the prompting packet 472 * (saddr6), if saddr6 belongs to the outgoing interface. 473 * Otherwise, we perform the source address selection as usual. 474 */ 475 476 if (saddr6 != NULL) 477 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6); 478 if (ifa != NULL) { 479 /* ip6_src set already. */ 480 ip6->ip6_src = *saddr6; 481 ifa_free(ifa); 482 } else { 483 int error; 484 struct in6_addr dst6, src6; 485 uint32_t scopeid; 486 487 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid); 488 error = in6_selectsrc_addr(RT_DEFAULT_FIB, &dst6, 489 scopeid, ifp, &src6, NULL); 490 if (error) { 491 char ip6buf[INET6_ADDRSTRLEN]; 492 nd6log((LOG_DEBUG, "%s: source can't be " 493 "determined: dst=%s, error=%d\n", __func__, 494 ip6_sprintf(ip6buf, &dst6), 495 error)); 496 goto bad; 497 } 498 ip6->ip6_src = src6; 499 } 500 } else { 501 /* 502 * Source address for DAD packet must always be IPv6 503 * unspecified address. (0::0) 504 * We actually don't have to 0-clear the address (we did it 505 * above), but we do so here explicitly to make the intention 506 * clearer. 507 */ 508 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 509 } 510 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 511 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 512 nd_ns->nd_ns_code = 0; 513 nd_ns->nd_ns_reserved = 0; 514 nd_ns->nd_ns_target = *taddr6; 515 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 516 517 /* 518 * Add source link-layer address option. 519 * 520 * spec implementation 521 * --- --- 522 * DAD packet MUST NOT do not add the option 523 * there's no link layer address: 524 * impossible do not add the option 525 * there's link layer address: 526 * Multicast NS MUST add one add the option 527 * Unicast NS SHOULD add one add the option 528 */ 529 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 530 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 531 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 532 /* 8 byte alignments... */ 533 optlen = (optlen + 7) & ~7; 534 535 m->m_pkthdr.len += optlen; 536 m->m_len += optlen; 537 icmp6len += optlen; 538 bzero((caddr_t)nd_opt, optlen); 539 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 540 nd_opt->nd_opt_len = optlen >> 3; 541 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 542 } 543 /* 544 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 545 * This behavior is documented as Enhanced Duplicate Address 546 * Detection in RFC 7527. 547 * net.inet6.ip6.dad_enhanced=0 disables this. 548 */ 549 if (V_dad_enhanced != 0 && nonce != NULL) { 550 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 551 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 552 /* 8-byte alignment is required. */ 553 optlen = (optlen + 7) & ~7; 554 555 m->m_pkthdr.len += optlen; 556 m->m_len += optlen; 557 icmp6len += optlen; 558 bzero((caddr_t)nd_opt, optlen); 559 nd_opt->nd_opt_type = ND_OPT_NONCE; 560 nd_opt->nd_opt_len = optlen >> 3; 561 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 562 } 563 ip6->ip6_plen = htons((u_short)icmp6len); 564 nd_ns->nd_ns_cksum = 0; 565 nd_ns->nd_ns_cksum = 566 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 567 568 if (send_sendso_input_hook != NULL) { 569 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 570 sizeof(unsigned short), M_NOWAIT); 571 if (mtag == NULL) 572 goto bad; 573 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 574 m_tag_prepend(m, mtag); 575 } 576 577 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 578 &im6o, NULL, NULL); 579 icmp6_ifstat_inc(ifp, ifs6_out_msg); 580 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 581 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 582 583 return; 584 585 bad: 586 m_freem(m); 587 return; 588} 589 590#ifndef BURN_BRIDGES 591void 592nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6, 593 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce) 594{ 595 596 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB); 597} 598#endif 599/* 600 * Neighbor advertisement input handling. 601 * 602 * Based on RFC 2461 603 * Based on RFC 2462 (duplicate address detection) 604 * 605 * the following items are not implemented yet: 606 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 607 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 608 */ 609void 610nd6_na_input(struct mbuf *m, int off, int icmp6len) 611{ 612 struct ifnet *ifp = m->m_pkthdr.rcvif; 613 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 614 struct nd_neighbor_advert *nd_na; 615 struct in6_addr daddr6 = ip6->ip6_dst; 616 struct in6_addr taddr6; 617 int flags; 618 int is_router; 619 int is_solicited; 620 int is_override; 621 char *lladdr = NULL; 622 int lladdrlen = 0; 623 int checklink = 0; 624 struct ifaddr *ifa; 625 struct llentry *ln = NULL; 626 union nd_opts ndopts; 627 struct mbuf *chain = NULL; 628 struct sockaddr_in6 sin6; 629 u_char linkhdr[LLE_MAX_LINKHDR]; 630 size_t linkhdrsize; 631 int lladdr_off; 632 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 633 634 if (ip6->ip6_hlim != 255) { 635 nd6log((LOG_ERR, 636 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 637 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 638 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 639 goto bad; 640 } 641 642#ifndef PULLDOWN_TEST 643 IP6_EXTHDR_CHECK(m, off, icmp6len,); 644 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 645#else 646 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 647 if (nd_na == NULL) { 648 ICMP6STAT_INC(icp6s_tooshort); 649 return; 650 } 651#endif 652 653 flags = nd_na->nd_na_flags_reserved; 654 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 655 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 656 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 657 memset(&sin6, 0, sizeof(sin6)); 658 659 taddr6 = nd_na->nd_na_target; 660 if (in6_setscope(&taddr6, ifp, NULL)) 661 goto bad; /* XXX: impossible */ 662 663 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 664 nd6log((LOG_ERR, 665 "nd6_na_input: invalid target address %s\n", 666 ip6_sprintf(ip6bufs, &taddr6))); 667 goto bad; 668 } 669 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 670 if (is_solicited) { 671 nd6log((LOG_ERR, 672 "nd6_na_input: a solicited adv is multicasted\n")); 673 goto bad; 674 } 675 676 icmp6len -= sizeof(*nd_na); 677 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 678 if (nd6_options(&ndopts) < 0) { 679 nd6log((LOG_INFO, 680 "nd6_na_input: invalid ND option, ignored\n")); 681 /* nd6_options have incremented stats */ 682 goto freeit; 683 } 684 685 if (ndopts.nd_opts_tgt_lladdr) { 686 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 687 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 688 } 689 690 /* 691 * This effectively disables the DAD check on a non-master CARP 692 * address. 693 */ 694 if (ifp->if_carp) 695 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 696 else 697 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 698 699 /* 700 * Target address matches one of my interface address. 701 * 702 * If my address is tentative, this means that there's somebody 703 * already using the same address as mine. This indicates DAD failure. 704 * This is defined in RFC 2462. 705 * 706 * Otherwise, process as defined in RFC 2461. 707 */ 708 if (ifa 709 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 710 nd6_dad_na_input(ifa); 711 ifa_free(ifa); 712 goto freeit; 713 } 714 715 /* Just for safety, maybe unnecessary. */ 716 if (ifa) { 717 ifa_free(ifa); 718 log(LOG_ERR, 719 "nd6_na_input: duplicate IP6 address %s\n", 720 ip6_sprintf(ip6bufs, &taddr6)); 721 goto freeit; 722 } 723 724 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 725 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 726 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 727 ifp->if_addrlen, lladdrlen - 2)); 728 goto bad; 729 } 730 731 /* 732 * If no neighbor cache entry is found, NA SHOULD silently be 733 * discarded. 734 */ 735 IF_AFDATA_RLOCK(ifp); 736 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 737 IF_AFDATA_RUNLOCK(ifp); 738 if (ln == NULL) { 739 goto freeit; 740 } 741 742 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 743 /* 744 * If the link-layer has address, and no lladdr option came, 745 * discard the packet. 746 */ 747 if (ifp->if_addrlen && lladdr == NULL) { 748 goto freeit; 749 } 750 751 /* 752 * Record link-layer address, and update the state. 753 */ 754 linkhdrsize = sizeof(linkhdr); 755 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 756 linkhdr, &linkhdrsize, &lladdr_off) != 0) 757 return; 758 759 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize, 760 lladdr_off) == 0) { 761 ln = NULL; 762 goto freeit; 763 } 764 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 765 if (is_solicited) 766 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 767 else 768 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 769 if ((ln->ln_router = is_router) != 0) { 770 /* 771 * This means a router's state has changed from 772 * non-reachable to probably reachable, and might 773 * affect the status of associated prefixes.. 774 */ 775 checklink = 1; 776 } 777 } else { 778 int llchange; 779 780 /* 781 * Check if the link-layer address has changed or not. 782 */ 783 if (lladdr == NULL) 784 llchange = 0; 785 else { 786 if (ln->la_flags & LLE_VALID) { 787 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen)) 788 llchange = 1; 789 else 790 llchange = 0; 791 } else 792 llchange = 1; 793 } 794 795 /* 796 * This is VERY complex. Look at it with care. 797 * 798 * override solicit lladdr llchange action 799 * (L: record lladdr) 800 * 801 * 0 0 n -- (2c) 802 * 0 0 y n (2b) L 803 * 0 0 y y (1) REACHABLE->STALE 804 * 0 1 n -- (2c) *->REACHABLE 805 * 0 1 y n (2b) L *->REACHABLE 806 * 0 1 y y (1) REACHABLE->STALE 807 * 1 0 n -- (2a) 808 * 1 0 y n (2a) L 809 * 1 0 y y (2a) L *->STALE 810 * 1 1 n -- (2a) *->REACHABLE 811 * 1 1 y n (2a) L *->REACHABLE 812 * 1 1 y y (2a) L *->REACHABLE 813 */ 814 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 815 /* 816 * If state is REACHABLE, make it STALE. 817 * no other updates should be done. 818 */ 819 if (ln->ln_state == ND6_LLINFO_REACHABLE) 820 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 821 goto freeit; 822 } else if (is_override /* (2a) */ 823 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 824 || lladdr == NULL) { /* (2c) */ 825 /* 826 * Update link-local address, if any. 827 */ 828 if (lladdr != NULL) { 829 linkhdrsize = sizeof(linkhdr); 830 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, 831 linkhdr, &linkhdrsize, &lladdr_off) != 0) 832 goto freeit; 833 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, 834 linkhdrsize, lladdr_off) == 0) { 835 ln = NULL; 836 goto freeit; 837 } 838 EVENTHANDLER_INVOKE(lle_event, ln, 839 LLENTRY_RESOLVED); 840 } 841 842 /* 843 * If solicited, make the state REACHABLE. 844 * If not solicited and the link-layer address was 845 * changed, make it STALE. 846 */ 847 if (is_solicited) 848 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE); 849 else { 850 if (lladdr != NULL && llchange) 851 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); 852 } 853 } 854 855 if (ln->ln_router && !is_router) { 856 /* 857 * The peer dropped the router flag. 858 * Remove the sender from the Default Router List and 859 * update the Destination Cache entries. 860 */ 861 struct nd_defrouter *dr; 862 struct in6_addr *in6; 863 struct ifnet *nd6_ifp; 864 865 in6 = &ln->r_l3addr.addr6; 866 867 /* 868 * Lock to protect the default router list. 869 * XXX: this might be unnecessary, since this function 870 * is only called under the network software interrupt 871 * context. However, we keep it just for safety. 872 */ 873 nd6_ifp = lltable_get_ifp(ln->lle_tbl); 874 dr = defrouter_lookup(in6, nd6_ifp); 875 if (dr) 876 defrtrlist_del(dr); 877 else if (ND_IFINFO(nd6_ifp)->flags & 878 ND6_IFF_ACCEPT_RTADV) { 879 /* 880 * Even if the neighbor is not in the default 881 * router list, the neighbor may be used 882 * as a next hop for some destinations 883 * (e.g. redirect case). So we must 884 * call rt6_flush explicitly. 885 */ 886 rt6_flush(&ip6->ip6_src, ifp); 887 } 888 } 889 ln->ln_router = is_router; 890 } 891 /* XXX - QL 892 * Does this matter? 893 * rt->rt_flags &= ~RTF_REJECT; 894 */ 895 ln->la_asked = 0; 896 if (ln->la_hold != NULL) 897 nd6_grab_holdchain(ln, &chain, &sin6); 898 freeit: 899 if (ln != NULL) 900 LLE_WUNLOCK(ln); 901 902 if (chain != NULL) 903 nd6_flush_holdchain(ifp, ifp, chain, &sin6); 904 905 if (checklink) 906 pfxlist_onlink_check(); 907 908 m_freem(m); 909 return; 910 911 bad: 912 if (ln != NULL) 913 LLE_WUNLOCK(ln); 914 915 ICMP6STAT_INC(icp6s_badna); 916 m_freem(m); 917} 918 919/* 920 * Neighbor advertisement output handling. 921 * 922 * Based on RFC 2461 923 * 924 * the following items are not implemented yet: 925 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 926 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 927 * 928 * tlladdr - 1 if include target link-layer address 929 * sdl0 - sockaddr_dl (= proxy NA) or NULL 930 */ 931static void 932nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 933 const struct in6_addr *taddr6, u_long flags, int tlladdr, 934 struct sockaddr *sdl0, u_int fibnum) 935{ 936 struct mbuf *m; 937 struct m_tag *mtag; 938 struct ip6_hdr *ip6; 939 struct nd_neighbor_advert *nd_na; 940 struct ip6_moptions im6o; 941 struct in6_addr daddr6, dst6, src6; 942 uint32_t scopeid; 943 944 int icmp6len, maxlen, error; 945 caddr_t mac = NULL; 946 947 daddr6 = *daddr6_0; /* make a local copy for modification */ 948 949 /* estimate the size of message */ 950 maxlen = sizeof(*ip6) + sizeof(*nd_na); 951 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 952 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 953 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 954 __func__, max_linkhdr, maxlen, MCLBYTES)); 955 956 if (max_linkhdr + maxlen > MHLEN) 957 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 958 else 959 m = m_gethdr(M_NOWAIT, MT_DATA); 960 if (m == NULL) 961 return; 962 M_SETFIB(m, fibnum); 963 964 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 965 m->m_flags |= M_MCAST; 966 im6o.im6o_multicast_ifp = ifp; 967 im6o.im6o_multicast_hlim = 255; 968 im6o.im6o_multicast_loop = 0; 969 } 970 971 icmp6len = sizeof(*nd_na); 972 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 973 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 974 975 /* fill neighbor advertisement packet */ 976 ip6 = mtod(m, struct ip6_hdr *); 977 ip6->ip6_flow = 0; 978 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 979 ip6->ip6_vfc |= IPV6_VERSION; 980 ip6->ip6_nxt = IPPROTO_ICMPV6; 981 ip6->ip6_hlim = 255; 982 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 983 /* reply to DAD */ 984 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 985 daddr6.s6_addr16[1] = 0; 986 daddr6.s6_addr32[1] = 0; 987 daddr6.s6_addr32[2] = 0; 988 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 989 if (in6_setscope(&daddr6, ifp, NULL)) 990 goto bad; 991 992 flags &= ~ND_NA_FLAG_SOLICITED; 993 } 994 ip6->ip6_dst = daddr6; 995 996 /* 997 * Select a source whose scope is the same as that of the dest. 998 */ 999 in6_splitscope(&daddr6, &dst6, &scopeid); 1000 error = in6_selectsrc_addr(RT_DEFAULT_FIB, &dst6, 1001 scopeid, ifp, &src6, NULL); 1002 if (error) { 1003 char ip6buf[INET6_ADDRSTRLEN]; 1004 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1005 "determined: dst=%s, error=%d\n", 1006 ip6_sprintf(ip6buf, &daddr6), error)); 1007 goto bad; 1008 } 1009 ip6->ip6_src = src6; 1010 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1011 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1012 nd_na->nd_na_code = 0; 1013 nd_na->nd_na_target = *taddr6; 1014 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1015 1016 /* 1017 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1018 * see nd6_ns_input() for details. 1019 * Basically, if NS packet is sent to unicast/anycast addr, 1020 * target lladdr option SHOULD NOT be included. 1021 */ 1022 if (tlladdr) { 1023 /* 1024 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1025 * lladdr in sdl0. If we are not proxying (sending NA for 1026 * my address) use lladdr configured for the interface. 1027 */ 1028 if (sdl0 == NULL) { 1029 if (ifp->if_carp) 1030 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1031 if (mac == NULL) 1032 mac = nd6_ifptomac(ifp); 1033 } else if (sdl0->sa_family == AF_LINK) { 1034 struct sockaddr_dl *sdl; 1035 sdl = (struct sockaddr_dl *)sdl0; 1036 if (sdl->sdl_alen == ifp->if_addrlen) 1037 mac = LLADDR(sdl); 1038 } 1039 } 1040 if (tlladdr && mac) { 1041 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1042 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1043 1044 /* roundup to 8 bytes alignment! */ 1045 optlen = (optlen + 7) & ~7; 1046 1047 m->m_pkthdr.len += optlen; 1048 m->m_len += optlen; 1049 icmp6len += optlen; 1050 bzero((caddr_t)nd_opt, optlen); 1051 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1052 nd_opt->nd_opt_len = optlen >> 3; 1053 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1054 } else 1055 flags &= ~ND_NA_FLAG_OVERRIDE; 1056 1057 ip6->ip6_plen = htons((u_short)icmp6len); 1058 nd_na->nd_na_flags_reserved = flags; 1059 nd_na->nd_na_cksum = 0; 1060 nd_na->nd_na_cksum = 1061 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1062 1063 if (send_sendso_input_hook != NULL) { 1064 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1065 sizeof(unsigned short), M_NOWAIT); 1066 if (mtag == NULL) 1067 goto bad; 1068 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1069 m_tag_prepend(m, mtag); 1070 } 1071 1072 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1073 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1074 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1075 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1076 1077 return; 1078 1079 bad: 1080 m_freem(m); 1081 return; 1082} 1083 1084#ifndef BURN_BRIDGES 1085void 1086nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1087 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1088 struct sockaddr *sdl0) 1089{ 1090 1091 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1092 RT_DEFAULT_FIB); 1093} 1094#endif 1095 1096caddr_t 1097nd6_ifptomac(struct ifnet *ifp) 1098{ 1099 switch (ifp->if_type) { 1100 case IFT_ARCNET: 1101 case IFT_ETHER: 1102 case IFT_FDDI: 1103 case IFT_IEEE1394: 1104 case IFT_L2VLAN: 1105 case IFT_IEEE80211: 1106 case IFT_INFINIBAND: 1107 case IFT_BRIDGE: 1108 case IFT_ISO88025: 1109 return IF_LLADDR(ifp); 1110 default: 1111 return NULL; 1112 } 1113} 1114 1115struct dadq { 1116 TAILQ_ENTRY(dadq) dad_list; 1117 struct ifaddr *dad_ifa; 1118 int dad_count; /* max NS to send */ 1119 int dad_ns_tcount; /* # of trials to send NS */ 1120 int dad_ns_ocount; /* NS sent so far */ 1121 int dad_ns_icount; 1122 int dad_na_icount; 1123 int dad_ns_lcount; /* looped back NS */ 1124 int dad_loopbackprobe; /* probing state for loopback detection */ 1125 struct callout dad_timer_ch; 1126 struct vnet *dad_vnet; 1127 u_int dad_refcnt; 1128#define ND_OPT_NONCE_LEN32 \ 1129 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1130 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1131}; 1132 1133static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq); 1134static VNET_DEFINE(struct rwlock, dad_rwlock); 1135#define V_dadq VNET(dadq) 1136#define V_dad_rwlock VNET(dad_rwlock) 1137 1138#define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1139#define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1140#define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1141#define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1142 1143static void 1144nd6_dad_add(struct dadq *dp) 1145{ 1146 1147 DADQ_WLOCK(); 1148 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1149 DADQ_WUNLOCK(); 1150} 1151 1152static void 1153nd6_dad_del(struct dadq *dp) 1154{ 1155 1156 DADQ_WLOCK(); 1157 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1158 DADQ_WUNLOCK(); 1159 nd6_dad_rele(dp); 1160} 1161 1162static struct dadq * 1163nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1164{ 1165 struct dadq *dp; 1166 1167 DADQ_RLOCK(); 1168 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1169 if (dp->dad_ifa != ifa) 1170 continue; 1171 /* 1172 * Skip if the nonce matches the received one. 1173 * +2 in the length is required because of type and 1174 * length fields are included in a header. 1175 */ 1176 if (n != NULL && 1177 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1178 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1179 ND_OPT_NONCE_LEN) == 0) { 1180 dp->dad_ns_lcount++; 1181 continue; 1182 } 1183 refcount_acquire(&dp->dad_refcnt); 1184 break; 1185 } 1186 DADQ_RUNLOCK(); 1187 1188 return (dp); 1189} 1190 1191static void 1192nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns) 1193{ 1194 1195 if (send_ns != 0) 1196 nd6_dad_ns_output(dp); 1197 callout_reset(&dp->dad_timer_ch, ticks, 1198 (void (*)(void *))nd6_dad_timer, (void *)dp); 1199} 1200 1201static void 1202nd6_dad_stoptimer(struct dadq *dp) 1203{ 1204 1205 callout_drain(&dp->dad_timer_ch); 1206} 1207 1208static void 1209nd6_dad_rele(struct dadq *dp) 1210{ 1211 1212 if (refcount_release(&dp->dad_refcnt)) { 1213 ifa_free(dp->dad_ifa); 1214 free(dp, M_IP6NDP); 1215 } 1216} 1217 1218void 1219nd6_dad_init(void) 1220{ 1221 1222 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1223 TAILQ_INIT(&V_dadq); 1224} 1225 1226/* 1227 * Start Duplicate Address Detection (DAD) for specified interface address. 1228 */ 1229void 1230nd6_dad_start(struct ifaddr *ifa, int delay) 1231{ 1232 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1233 struct dadq *dp; 1234 char ip6buf[INET6_ADDRSTRLEN]; 1235 int send_ns; 1236 1237 /* 1238 * If we don't need DAD, don't do it. 1239 * There are several cases: 1240 * - DAD is disabled (ip6_dad_count == 0) 1241 * - the interface address is anycast 1242 */ 1243 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1244 log(LOG_DEBUG, 1245 "nd6_dad_start: called with non-tentative address " 1246 "%s(%s)\n", 1247 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1248 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1249 return; 1250 } 1251 if (ia->ia6_flags & IN6_IFF_ANYCAST) { 1252 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1253 return; 1254 } 1255 if (!V_ip6_dad_count) { 1256 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1257 return; 1258 } 1259 if (ifa->ifa_ifp == NULL) 1260 panic("nd6_dad_start: ifa->ifa_ifp == NULL"); 1261 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) { 1262 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1263 return; 1264 } 1265 if (!(ifa->ifa_ifp->if_flags & IFF_UP) || 1266 !(ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) || 1267 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED)) { 1268 ia->ia6_flags |= IN6_IFF_TENTATIVE; 1269 return; 1270 } 1271 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1272 /* 1273 * DAD already in progress. Let the existing entry 1274 * to finish it. 1275 */ 1276 return; 1277 } 1278 1279 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1280 if (dp == NULL) { 1281 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1282 "%s(%s)\n", 1283 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1284 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1285 return; 1286 } 1287 callout_init(&dp->dad_timer_ch, 0); 1288#ifdef VIMAGE 1289 dp->dad_vnet = curvnet; 1290#endif 1291 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1292 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1293 1294 /* 1295 * Send NS packet for DAD, ip6_dad_count times. 1296 * Note that we must delay the first transmission, if this is the 1297 * first packet to be sent from the interface after interface 1298 * (re)initialization. 1299 */ 1300 dp->dad_ifa = ifa; 1301 ifa_ref(dp->dad_ifa); 1302 dp->dad_count = V_ip6_dad_count; 1303 dp->dad_ns_icount = dp->dad_na_icount = 0; 1304 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1305 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1306 refcount_init(&dp->dad_refcnt, 1); 1307 nd6_dad_add(dp); 1308 send_ns = 0; 1309 if (delay == 0) { 1310 send_ns = 1; 1311 delay = (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000; 1312 } 1313 nd6_dad_starttimer(dp, delay, send_ns); 1314} 1315 1316/* 1317 * terminate DAD unconditionally. used for address removals. 1318 */ 1319void 1320nd6_dad_stop(struct ifaddr *ifa) 1321{ 1322 struct dadq *dp; 1323 1324 dp = nd6_dad_find(ifa, NULL); 1325 if (!dp) { 1326 /* DAD wasn't started yet */ 1327 return; 1328 } 1329 1330 nd6_dad_stoptimer(dp); 1331 1332 /* 1333 * The DAD queue entry may have been removed by nd6_dad_timer() while 1334 * we were waiting for it to stop, so re-do the lookup. 1335 */ 1336 nd6_dad_rele(dp); 1337 if (nd6_dad_find(ifa, NULL) == NULL) 1338 return; 1339 1340 nd6_dad_del(dp); 1341 nd6_dad_rele(dp); 1342} 1343 1344static void 1345nd6_dad_timer(struct dadq *dp) 1346{ 1347 CURVNET_SET(dp->dad_vnet); 1348 struct ifaddr *ifa = dp->dad_ifa; 1349 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1350 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1351 char ip6buf[INET6_ADDRSTRLEN]; 1352 1353 /* Sanity check */ 1354 if (ia == NULL) { 1355 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n"); 1356 goto err; 1357 } 1358 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1359 /* Do not need DAD for ifdisabled interface. */ 1360 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1361 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1362 goto err; 1363 } 1364 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1365 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1366 "%s(%s)\n", 1367 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1368 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1369 goto err; 1370 } 1371 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1372 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1373 "%s(%s)\n", 1374 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1375 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1376 goto err; 1377 } 1378 1379 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1380 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1381 (((ifp->if_flags & IFF_UP) == 0) || 1382 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1383 nd6log((LOG_INFO, "%s: could not run DAD " 1384 "because the interface was down or not running.\n", 1385 if_name(ifa->ifa_ifp))); 1386 goto err; 1387 } 1388 1389 /* Need more checks? */ 1390 if (dp->dad_ns_ocount < dp->dad_count) { 1391 /* 1392 * We have more NS to go. Send NS packet for DAD. 1393 */ 1394 nd6_dad_starttimer(dp, 1395 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1); 1396 goto done; 1397 } else { 1398 /* 1399 * We have transmitted sufficient number of DAD packets. 1400 * See what we've got. 1401 */ 1402 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1403 /* We've seen NS or NA, means DAD has failed. */ 1404 nd6_dad_duplicated(ifa, dp); 1405 else if (V_dad_enhanced != 0 && 1406 dp->dad_ns_lcount > 0 && 1407 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1408 /* 1409 * Sec. 4.1 in RFC 7527 requires transmission of 1410 * additional probes until the loopback condition 1411 * becomes clear when a looped back probe is detected. 1412 */ 1413 log(LOG_ERR, "%s: a looped back NS message is " 1414 "detected during DAD for %s. " 1415 "Another DAD probes are being sent.\n", 1416 if_name(ifa->ifa_ifp), 1417 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1418 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1419 /* 1420 * Send an NS immediately and increase dad_count by 1421 * V_nd6_mmaxtries - 1. 1422 */ 1423 dp->dad_count = 1424 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1425 nd6_dad_starttimer(dp, 1426 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1427 1); 1428 goto done; 1429 } else { 1430 /* 1431 * We are done with DAD. No NA came, no NS came. 1432 * No duplicate address found. Check IFDISABLED flag 1433 * again in case that it is changed between the 1434 * beginning of this function and here. 1435 */ 1436 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1437 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1438 1439 nd6log((LOG_DEBUG, 1440 "%s: DAD complete for %s - no duplicates found\n", 1441 if_name(ifa->ifa_ifp), 1442 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1443 if (dp->dad_ns_lcount > 0) 1444 log(LOG_ERR, "%s: DAD completed while " 1445 "a looped back NS message is detected " 1446 "during DAD for %s.\n", 1447 if_name(ifa->ifa_ifp), 1448 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1449 } 1450 } 1451err: 1452 nd6_dad_del(dp); 1453done: 1454 CURVNET_RESTORE(); 1455} 1456 1457static void 1458nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1459{ 1460 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1461 struct ifnet *ifp; 1462 char ip6buf[INET6_ADDRSTRLEN]; 1463 1464 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1465 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1466 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1467 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1468 dp->dad_na_icount); 1469 1470 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1471 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1472 1473 ifp = ifa->ifa_ifp; 1474 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1475 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1476 log(LOG_ERR, "%s: manual intervention required\n", 1477 if_name(ifp)); 1478 1479 /* 1480 * If the address is a link-local address formed from an interface 1481 * identifier based on the hardware address which is supposed to be 1482 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1483 * operation on the interface SHOULD be disabled. 1484 * [RFC 4862, Section 5.4.5] 1485 */ 1486 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1487 struct in6_addr in6; 1488 1489 /* 1490 * To avoid over-reaction, we only apply this logic when we are 1491 * very sure that hardware addresses are supposed to be unique. 1492 */ 1493 switch (ifp->if_type) { 1494 case IFT_ETHER: 1495 case IFT_FDDI: 1496 case IFT_ATM: 1497 case IFT_IEEE1394: 1498 case IFT_IEEE80211: 1499 case IFT_INFINIBAND: 1500 in6 = ia->ia_addr.sin6_addr; 1501 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1502 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1503 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1504 log(LOG_ERR, "%s: possible hardware address " 1505 "duplication detected, disable IPv6\n", 1506 if_name(ifp)); 1507 } 1508 break; 1509 } 1510 } 1511} 1512 1513static void 1514nd6_dad_ns_output(struct dadq *dp) 1515{ 1516 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1517 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1518 int i; 1519 1520 dp->dad_ns_tcount++; 1521 if ((ifp->if_flags & IFF_UP) == 0) { 1522 return; 1523 } 1524 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1525 return; 1526 } 1527 1528 dp->dad_ns_ocount++; 1529 if (V_dad_enhanced != 0) { 1530 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1531 dp->dad_nonce[i] = arc4random(); 1532 /* 1533 * XXXHRS: Note that in the case that 1534 * DupAddrDetectTransmits > 1, multiple NS messages with 1535 * different nonces can be looped back in an unexpected 1536 * order. The current implementation recognizes only 1537 * the latest nonce on the sender side. Practically it 1538 * should work well in almost all cases. 1539 */ 1540 } 1541 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr, 1542 (uint8_t *)&dp->dad_nonce[0]); 1543} 1544 1545static void 1546nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1547{ 1548 struct in6_ifaddr *ia; 1549 struct ifnet *ifp; 1550 const struct in6_addr *taddr6; 1551 struct dadq *dp; 1552 1553 if (ifa == NULL) 1554 panic("ifa == NULL in nd6_dad_ns_input"); 1555 1556 ia = (struct in6_ifaddr *)ifa; 1557 ifp = ifa->ifa_ifp; 1558 taddr6 = &ia->ia_addr.sin6_addr; 1559 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1560 if (V_dad_enhanced == 0) 1561 ndopt_nonce = NULL; 1562 dp = nd6_dad_find(ifa, ndopt_nonce); 1563 if (dp == NULL) 1564 return; 1565 1566 dp->dad_ns_icount++; 1567 nd6_dad_rele(dp); 1568} 1569 1570static void 1571nd6_dad_na_input(struct ifaddr *ifa) 1572{ 1573 struct dadq *dp; 1574 1575 if (ifa == NULL) 1576 panic("ifa == NULL in nd6_dad_na_input"); 1577 1578 dp = nd6_dad_find(ifa, NULL); 1579 if (dp != NULL) { 1580 dp->dad_na_icount++; 1581 nd6_dad_rele(dp); 1582 } 1583} 1584