nd6_nbr.c revision 270923
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/10/sys/netinet6/nd6_nbr.c 270923 2014-09-01 08:33:38Z 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/lock.h> 44#include <sys/rwlock.h> 45#include <sys/mbuf.h> 46#include <sys/socket.h> 47#include <sys/sockio.h> 48#include <sys/time.h> 49#include <sys/kernel.h> 50#include <sys/errno.h> 51#include <sys/syslog.h> 52#include <sys/queue.h> 53#include <sys/callout.h> 54 55#include <net/if.h> 56#include <net/if_types.h> 57#include <net/if_dl.h> 58#include <net/if_var.h> 59#include <net/route.h> 60#ifdef RADIX_MPATH 61#include <net/radix_mpath.h> 62#endif 63 64#include <netinet/in.h> 65#include <netinet/in_var.h> 66#include <net/if_llatbl.h> 67#define L3_ADDR_SIN6(le) ((struct sockaddr_in6 *) L3_ADDR(le)) 68#include <netinet6/in6_var.h> 69#include <netinet6/in6_ifattach.h> 70#include <netinet/ip6.h> 71#include <netinet6/ip6_var.h> 72#include <netinet6/scope6_var.h> 73#include <netinet6/nd6.h> 74#include <netinet/icmp6.h> 75#include <netinet/ip_carp.h> 76#include <netinet6/send.h> 77 78#define SDL(s) ((struct sockaddr_dl *)s) 79 80struct dadq; 81static struct dadq *nd6_dad_find(struct ifaddr *); 82static void nd6_dad_starttimer(struct dadq *, int); 83static void nd6_dad_stoptimer(struct dadq *); 84static void nd6_dad_timer(struct dadq *); 85static void nd6_dad_ns_output(struct dadq *, struct ifaddr *); 86static void nd6_dad_ns_input(struct ifaddr *); 87static void nd6_dad_na_input(struct ifaddr *); 88static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 89 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 90 91VNET_DEFINE(int, dad_ignore_ns) = 0; /* ignore NS in DAD - specwise incorrect*/ 92VNET_DEFINE(int, dad_maxtry) = 15; /* max # of *tries* to transmit DAD packet */ 93#define V_dad_ignore_ns VNET(dad_ignore_ns) 94#define V_dad_maxtry VNET(dad_maxtry) 95 96/* 97 * Input a Neighbor Solicitation Message. 98 * 99 * Based on RFC 2461 100 * Based on RFC 2462 (duplicate address detection) 101 */ 102void 103nd6_ns_input(struct mbuf *m, int off, int icmp6len) 104{ 105 struct ifnet *ifp = m->m_pkthdr.rcvif; 106 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 107 struct nd_neighbor_solicit *nd_ns; 108 struct in6_addr saddr6 = ip6->ip6_src; 109 struct in6_addr daddr6 = ip6->ip6_dst; 110 struct in6_addr taddr6; 111 struct in6_addr myaddr6; 112 char *lladdr = NULL; 113 struct ifaddr *ifa = NULL; 114 int lladdrlen = 0; 115 int anycast = 0, proxy = 0, tentative = 0; 116 int tlladdr; 117 int rflag; 118 union nd_opts ndopts; 119 struct sockaddr_dl proxydl; 120 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 121 122 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 123 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 124 rflag = 0; 125#ifndef PULLDOWN_TEST 126 IP6_EXTHDR_CHECK(m, off, icmp6len,); 127 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 128#else 129 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); 130 if (nd_ns == NULL) { 131 ICMP6STAT_INC(icp6s_tooshort); 132 return; 133 } 134#endif 135 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ 136 taddr6 = nd_ns->nd_ns_target; 137 if (in6_setscope(&taddr6, ifp, NULL) != 0) 138 goto bad; 139 140 if (ip6->ip6_hlim != 255) { 141 nd6log((LOG_ERR, 142 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 143 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 144 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 145 goto bad; 146 } 147 148 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 149 /* dst has to be a solicited node multicast address. */ 150 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 151 /* don't check ifindex portion */ 152 daddr6.s6_addr32[1] == 0 && 153 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 154 daddr6.s6_addr8[12] == 0xff) { 155 ; /* good */ 156 } else { 157 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 158 "(wrong ip6 dst)\n")); 159 goto bad; 160 } 161 } else if (!V_nd6_onlink_ns_rfc4861) { 162 struct sockaddr_in6 src_sa6; 163 164 /* 165 * According to recent IETF discussions, it is not a good idea 166 * to accept a NS from an address which would not be deemed 167 * to be a neighbor otherwise. This point is expected to be 168 * clarified in future revisions of the specification. 169 */ 170 bzero(&src_sa6, sizeof(src_sa6)); 171 src_sa6.sin6_family = AF_INET6; 172 src_sa6.sin6_len = sizeof(src_sa6); 173 src_sa6.sin6_addr = saddr6; 174 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 175 nd6log((LOG_INFO, "nd6_ns_input: " 176 "NS packet from non-neighbor\n")); 177 goto bad; 178 } 179 } 180 181 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 182 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 183 goto bad; 184 } 185 186 icmp6len -= sizeof(*nd_ns); 187 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 188 if (nd6_options(&ndopts) < 0) { 189 nd6log((LOG_INFO, 190 "nd6_ns_input: invalid ND option, ignored\n")); 191 /* nd6_options have incremented stats */ 192 goto freeit; 193 } 194 195 if (ndopts.nd_opts_src_lladdr) { 196 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 197 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 198 } 199 200 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 201 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 202 "(link-layer address option)\n")); 203 goto bad; 204 } 205 206 /* 207 * Attaching target link-layer address to the NA? 208 * (RFC 2461 7.2.4) 209 * 210 * NS IP dst is unicast/anycast MUST NOT add 211 * NS IP dst is solicited-node multicast MUST add 212 * 213 * In implementation, we add target link-layer address by default. 214 * We do not add one in MUST NOT cases. 215 */ 216 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 217 tlladdr = 0; 218 else 219 tlladdr = 1; 220 221 /* 222 * Target address (taddr6) must be either: 223 * (1) Valid unicast/anycast address for my receiving interface, 224 * (2) Unicast address for which I'm offering proxy service, or 225 * (3) "tentative" address on which DAD is being performed. 226 */ 227 /* (1) and (3) check. */ 228 if (ifp->if_carp) 229 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 230 else 231 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 232 233 /* (2) check. */ 234 if (ifa == NULL) { 235 struct route_in6 ro; 236 int need_proxy; 237 238 bzero(&ro, sizeof(ro)); 239 ro.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 240 ro.ro_dst.sin6_family = AF_INET6; 241 ro.ro_dst.sin6_addr = taddr6; 242 243 /* Always use the default FIB. */ 244#ifdef RADIX_MPATH 245 rtalloc_mpath_fib((struct route *)&ro, RTF_ANNOUNCE, 246 RT_DEFAULT_FIB); 247#else 248 in6_rtalloc(&ro, RT_DEFAULT_FIB); 249#endif 250 need_proxy = (ro.ro_rt && 251 (ro.ro_rt->rt_flags & RTF_ANNOUNCE) != 0 && 252 ro.ro_rt->rt_gateway->sa_family == AF_LINK); 253 if (ro.ro_rt != NULL) { 254 if (need_proxy) 255 proxydl = *SDL(ro.ro_rt->rt_gateway); 256 RTFREE(ro.ro_rt); 257 } 258 if (need_proxy) { 259 /* 260 * proxy NDP for single entry 261 */ 262 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 263 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 264 if (ifa) 265 proxy = 1; 266 } 267 } 268 if (ifa == NULL) { 269 /* 270 * We've got an NS packet, and we don't have that adddress 271 * assigned for us. We MUST silently ignore it. 272 * See RFC2461 7.2.3. 273 */ 274 goto freeit; 275 } 276 myaddr6 = *IFA_IN6(ifa); 277 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 278 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 279 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 280 goto freeit; 281 282 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 283 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 284 "(if %d, NS packet %d)\n", 285 ip6_sprintf(ip6bufs, &taddr6), 286 ifp->if_addrlen, lladdrlen - 2)); 287 goto bad; 288 } 289 290 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 291 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 292 ip6_sprintf(ip6bufs, &saddr6))); 293 goto freeit; 294 } 295 296 /* 297 * We have neighbor solicitation packet, with target address equals to 298 * one of my tentative address. 299 * 300 * src addr how to process? 301 * --- --- 302 * multicast of course, invalid (rejected in ip6_input) 303 * unicast somebody is doing address resolution -> ignore 304 * unspec dup address detection 305 * 306 * The processing is defined in RFC 2462. 307 */ 308 if (tentative) { 309 /* 310 * If source address is unspecified address, it is for 311 * duplicate address detection. 312 * 313 * If not, the packet is for addess resolution; 314 * silently ignore it. 315 */ 316 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 317 nd6_dad_ns_input(ifa); 318 319 goto freeit; 320 } 321 322 /* 323 * If the source address is unspecified address, entries must not 324 * be created or updated. 325 * It looks that sender is performing DAD. Output NA toward 326 * all-node multicast address, to tell the sender that I'm using 327 * the address. 328 * S bit ("solicited") must be zero. 329 */ 330 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 331 struct in6_addr in6_all; 332 333 in6_all = in6addr_linklocal_allnodes; 334 if (in6_setscope(&in6_all, ifp, NULL) != 0) 335 goto bad; 336 nd6_na_output_fib(ifp, &in6_all, &taddr6, 337 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 338 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 339 M_GETFIB(m)); 340 goto freeit; 341 } 342 343 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 344 ND_NEIGHBOR_SOLICIT, 0); 345 346 nd6_na_output_fib(ifp, &saddr6, &taddr6, 347 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 348 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 349 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 350 freeit: 351 if (ifa != NULL) 352 ifa_free(ifa); 353 m_freem(m); 354 return; 355 356 bad: 357 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 358 ip6_sprintf(ip6bufs, &saddr6))); 359 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 360 ip6_sprintf(ip6bufs, &daddr6))); 361 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 362 ip6_sprintf(ip6bufs, &taddr6))); 363 ICMP6STAT_INC(icp6s_badns); 364 if (ifa != NULL) 365 ifa_free(ifa); 366 m_freem(m); 367} 368 369/* 370 * Output a Neighbor Solicitation Message. Caller specifies: 371 * - ICMP6 header source IP6 address 372 * - ND6 header target IP6 address 373 * - ND6 header source datalink address 374 * 375 * Based on RFC 2461 376 * Based on RFC 2462 (duplicate address detection) 377 * 378 * ln - for source address determination 379 * dad - duplicate address detection 380 */ 381void 382nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6, 383 const struct in6_addr *taddr6, struct llentry *ln, int dad) 384{ 385 struct mbuf *m; 386 struct m_tag *mtag; 387 struct ip6_hdr *ip6; 388 struct nd_neighbor_solicit *nd_ns; 389 struct ip6_moptions im6o; 390 int icmp6len; 391 int maxlen; 392 caddr_t mac; 393 struct route_in6 ro; 394 395 if (IN6_IS_ADDR_MULTICAST(taddr6)) 396 return; 397 398 /* estimate the size of message */ 399 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 400 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 401 if (max_linkhdr + maxlen >= MCLBYTES) { 402#ifdef DIAGNOSTIC 403 printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES " 404 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES); 405#endif 406 return; 407 } 408 409 if (max_linkhdr + maxlen > MHLEN) 410 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 411 else 412 m = m_gethdr(M_NOWAIT, MT_DATA); 413 if (m == NULL) 414 return; 415 416 bzero(&ro, sizeof(ro)); 417 418 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 419 m->m_flags |= M_MCAST; 420 im6o.im6o_multicast_ifp = ifp; 421 im6o.im6o_multicast_hlim = 255; 422 im6o.im6o_multicast_loop = 0; 423 } 424 425 icmp6len = sizeof(*nd_ns); 426 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 427 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 428 429 /* fill neighbor solicitation packet */ 430 ip6 = mtod(m, struct ip6_hdr *); 431 ip6->ip6_flow = 0; 432 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 433 ip6->ip6_vfc |= IPV6_VERSION; 434 /* ip6->ip6_plen will be set later */ 435 ip6->ip6_nxt = IPPROTO_ICMPV6; 436 ip6->ip6_hlim = 255; 437 if (daddr6) 438 ip6->ip6_dst = *daddr6; 439 else { 440 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 441 ip6->ip6_dst.s6_addr16[1] = 0; 442 ip6->ip6_dst.s6_addr32[1] = 0; 443 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 444 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 445 ip6->ip6_dst.s6_addr8[12] = 0xff; 446 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 447 goto bad; 448 } 449 if (!dad) { 450 struct ifaddr *ifa; 451 452 /* 453 * RFC2461 7.2.2: 454 * "If the source address of the packet prompting the 455 * solicitation is the same as one of the addresses assigned 456 * to the outgoing interface, that address SHOULD be placed 457 * in the IP Source Address of the outgoing solicitation. 458 * Otherwise, any one of the addresses assigned to the 459 * interface should be used." 460 * 461 * We use the source address for the prompting packet 462 * (saddr6), if: 463 * - saddr6 is given from the caller (by giving "ln"), and 464 * - saddr6 belongs to the outgoing interface. 465 * Otherwise, we perform the source address selection as usual. 466 */ 467 struct in6_addr *hsrc; 468 469 hsrc = NULL; 470 if (ln != NULL) { 471 LLE_RLOCK(ln); 472 if (ln->la_hold != NULL) { 473 struct ip6_hdr *hip6; /* hold ip6 */ 474 475 /* 476 * assuming every packet in la_hold has the same IP 477 * header 478 */ 479 hip6 = mtod(ln->la_hold, struct ip6_hdr *); 480 /* XXX pullup? */ 481 if (sizeof(*hip6) < ln->la_hold->m_len) { 482 ip6->ip6_src = hip6->ip6_src; 483 hsrc = &hip6->ip6_src; 484 } 485 } 486 LLE_RUNLOCK(ln); 487 } 488 if (hsrc && (ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, 489 hsrc)) != NULL) { 490 /* ip6_src set already. */ 491 ifa_free(ifa); 492 } else { 493 int error; 494 struct sockaddr_in6 dst_sa; 495 struct in6_addr src_in; 496 struct ifnet *oifp; 497 498 bzero(&dst_sa, sizeof(dst_sa)); 499 dst_sa.sin6_family = AF_INET6; 500 dst_sa.sin6_len = sizeof(dst_sa); 501 dst_sa.sin6_addr = ip6->ip6_dst; 502 503 oifp = ifp; 504 error = in6_selectsrc(&dst_sa, NULL, 505 NULL, &ro, NULL, &oifp, &src_in); 506 if (error) { 507 char ip6buf[INET6_ADDRSTRLEN]; 508 nd6log((LOG_DEBUG, 509 "nd6_ns_output: source can't be " 510 "determined: dst=%s, error=%d\n", 511 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), 512 error)); 513 goto bad; 514 } 515 ip6->ip6_src = src_in; 516 } 517 } else { 518 /* 519 * Source address for DAD packet must always be IPv6 520 * unspecified address. (0::0) 521 * We actually don't have to 0-clear the address (we did it 522 * above), but we do so here explicitly to make the intention 523 * clearer. 524 */ 525 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 526 } 527 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 528 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 529 nd_ns->nd_ns_code = 0; 530 nd_ns->nd_ns_reserved = 0; 531 nd_ns->nd_ns_target = *taddr6; 532 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 533 534 /* 535 * Add source link-layer address option. 536 * 537 * spec implementation 538 * --- --- 539 * DAD packet MUST NOT do not add the option 540 * there's no link layer address: 541 * impossible do not add the option 542 * there's link layer address: 543 * Multicast NS MUST add one add the option 544 * Unicast NS SHOULD add one add the option 545 */ 546 if (!dad && (mac = nd6_ifptomac(ifp))) { 547 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 548 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 549 /* 8 byte alignments... */ 550 optlen = (optlen + 7) & ~7; 551 552 m->m_pkthdr.len += optlen; 553 m->m_len += optlen; 554 icmp6len += optlen; 555 bzero((caddr_t)nd_opt, optlen); 556 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 557 nd_opt->nd_opt_len = optlen >> 3; 558 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 559 } 560 561 ip6->ip6_plen = htons((u_short)icmp6len); 562 nd_ns->nd_ns_cksum = 0; 563 nd_ns->nd_ns_cksum = 564 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 565 566 if (send_sendso_input_hook != NULL) { 567 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 568 sizeof(unsigned short), M_NOWAIT); 569 if (mtag == NULL) 570 goto bad; 571 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 572 m_tag_prepend(m, mtag); 573 } 574 575 ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL, NULL); 576 icmp6_ifstat_inc(ifp, ifs6_out_msg); 577 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 578 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 579 580 /* We don't cache this route. */ 581 RO_RTFREE(&ro); 582 583 return; 584 585 bad: 586 if (ro.ro_rt) { 587 RTFREE(ro.ro_rt); 588 } 589 m_freem(m); 590 return; 591} 592 593/* 594 * Neighbor advertisement input handling. 595 * 596 * Based on RFC 2461 597 * Based on RFC 2462 (duplicate address detection) 598 * 599 * the following items are not implemented yet: 600 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 601 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 602 */ 603void 604nd6_na_input(struct mbuf *m, int off, int icmp6len) 605{ 606 struct ifnet *ifp = m->m_pkthdr.rcvif; 607 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 608 struct nd_neighbor_advert *nd_na; 609 struct in6_addr daddr6 = ip6->ip6_dst; 610 struct in6_addr taddr6; 611 int flags; 612 int is_router; 613 int is_solicited; 614 int is_override; 615 char *lladdr = NULL; 616 int lladdrlen = 0; 617 int checklink = 0; 618 struct ifaddr *ifa; 619 struct llentry *ln = NULL; 620 union nd_opts ndopts; 621 struct mbuf *chain = NULL; 622 struct m_tag *mtag; 623 struct sockaddr_in6 sin6; 624 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 625 626 if (ip6->ip6_hlim != 255) { 627 nd6log((LOG_ERR, 628 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 629 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 630 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 631 goto bad; 632 } 633 634#ifndef PULLDOWN_TEST 635 IP6_EXTHDR_CHECK(m, off, icmp6len,); 636 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 637#else 638 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 639 if (nd_na == NULL) { 640 ICMP6STAT_INC(icp6s_tooshort); 641 return; 642 } 643#endif 644 645 flags = nd_na->nd_na_flags_reserved; 646 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 647 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 648 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 649 650 taddr6 = nd_na->nd_na_target; 651 if (in6_setscope(&taddr6, ifp, NULL)) 652 goto bad; /* XXX: impossible */ 653 654 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 655 nd6log((LOG_ERR, 656 "nd6_na_input: invalid target address %s\n", 657 ip6_sprintf(ip6bufs, &taddr6))); 658 goto bad; 659 } 660 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 661 if (is_solicited) { 662 nd6log((LOG_ERR, 663 "nd6_na_input: a solicited adv is multicasted\n")); 664 goto bad; 665 } 666 667 icmp6len -= sizeof(*nd_na); 668 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 669 if (nd6_options(&ndopts) < 0) { 670 nd6log((LOG_INFO, 671 "nd6_na_input: invalid ND option, ignored\n")); 672 /* nd6_options have incremented stats */ 673 goto freeit; 674 } 675 676 if (ndopts.nd_opts_tgt_lladdr) { 677 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 678 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 679 } 680 681 /* 682 * This effectively disables the DAD check on a non-master CARP 683 * address. 684 */ 685 if (ifp->if_carp) 686 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 687 else 688 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 689 690 /* 691 * Target address matches one of my interface address. 692 * 693 * If my address is tentative, this means that there's somebody 694 * already using the same address as mine. This indicates DAD failure. 695 * This is defined in RFC 2462. 696 * 697 * Otherwise, process as defined in RFC 2461. 698 */ 699 if (ifa 700 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 701 ifa_free(ifa); 702 nd6_dad_na_input(ifa); 703 goto freeit; 704 } 705 706 /* Just for safety, maybe unnecessary. */ 707 if (ifa) { 708 ifa_free(ifa); 709 log(LOG_ERR, 710 "nd6_na_input: duplicate IP6 address %s\n", 711 ip6_sprintf(ip6bufs, &taddr6)); 712 goto freeit; 713 } 714 715 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 716 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 717 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 718 ifp->if_addrlen, lladdrlen - 2)); 719 goto bad; 720 } 721 722 /* 723 * If no neighbor cache entry is found, NA SHOULD silently be 724 * discarded. 725 */ 726 IF_AFDATA_RLOCK(ifp); 727 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 728 IF_AFDATA_RUNLOCK(ifp); 729 if (ln == NULL) { 730 goto freeit; 731 } 732 733 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 734 /* 735 * If the link-layer has address, and no lladdr option came, 736 * discard the packet. 737 */ 738 if (ifp->if_addrlen && lladdr == NULL) { 739 goto freeit; 740 } 741 742 /* 743 * Record link-layer address, and update the state. 744 */ 745 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen); 746 ln->la_flags |= LLE_VALID; 747 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 748 if (is_solicited) { 749 ln->ln_state = ND6_LLINFO_REACHABLE; 750 ln->ln_byhint = 0; 751 if (!ND6_LLINFO_PERMANENT(ln)) { 752 nd6_llinfo_settimer_locked(ln, 753 (long)ND_IFINFO(ln->lle_tbl->llt_ifp)->reachable * hz); 754 } 755 } else { 756 ln->ln_state = ND6_LLINFO_STALE; 757 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz); 758 } 759 if ((ln->ln_router = is_router) != 0) { 760 /* 761 * This means a router's state has changed from 762 * non-reachable to probably reachable, and might 763 * affect the status of associated prefixes.. 764 */ 765 checklink = 1; 766 } 767 } else { 768 int llchange; 769 770 /* 771 * Check if the link-layer address has changed or not. 772 */ 773 if (lladdr == NULL) 774 llchange = 0; 775 else { 776 if (ln->la_flags & LLE_VALID) { 777 if (bcmp(lladdr, &ln->ll_addr, ifp->if_addrlen)) 778 llchange = 1; 779 else 780 llchange = 0; 781 } else 782 llchange = 1; 783 } 784 785 /* 786 * This is VERY complex. Look at it with care. 787 * 788 * override solicit lladdr llchange action 789 * (L: record lladdr) 790 * 791 * 0 0 n -- (2c) 792 * 0 0 y n (2b) L 793 * 0 0 y y (1) REACHABLE->STALE 794 * 0 1 n -- (2c) *->REACHABLE 795 * 0 1 y n (2b) L *->REACHABLE 796 * 0 1 y y (1) REACHABLE->STALE 797 * 1 0 n -- (2a) 798 * 1 0 y n (2a) L 799 * 1 0 y y (2a) L *->STALE 800 * 1 1 n -- (2a) *->REACHABLE 801 * 1 1 y n (2a) L *->REACHABLE 802 * 1 1 y y (2a) L *->REACHABLE 803 */ 804 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 805 /* 806 * If state is REACHABLE, make it STALE. 807 * no other updates should be done. 808 */ 809 if (ln->ln_state == ND6_LLINFO_REACHABLE) { 810 ln->ln_state = ND6_LLINFO_STALE; 811 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz); 812 } 813 goto freeit; 814 } else if (is_override /* (2a) */ 815 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 816 || lladdr == NULL) { /* (2c) */ 817 /* 818 * Update link-local address, if any. 819 */ 820 if (lladdr != NULL) { 821 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen); 822 ln->la_flags |= LLE_VALID; 823 EVENTHANDLER_INVOKE(lle_event, ln, 824 LLENTRY_RESOLVED); 825 } 826 827 /* 828 * If solicited, make the state REACHABLE. 829 * If not solicited and the link-layer address was 830 * changed, make it STALE. 831 */ 832 if (is_solicited) { 833 ln->ln_state = ND6_LLINFO_REACHABLE; 834 ln->ln_byhint = 0; 835 if (!ND6_LLINFO_PERMANENT(ln)) { 836 nd6_llinfo_settimer_locked(ln, 837 (long)ND_IFINFO(ifp)->reachable * hz); 838 } 839 } else { 840 if (lladdr != NULL && llchange) { 841 ln->ln_state = ND6_LLINFO_STALE; 842 nd6_llinfo_settimer_locked(ln, 843 (long)V_nd6_gctimer * hz); 844 } 845 } 846 } 847 848 if (ln->ln_router && !is_router) { 849 /* 850 * The peer dropped the router flag. 851 * Remove the sender from the Default Router List and 852 * update the Destination Cache entries. 853 */ 854 struct nd_defrouter *dr; 855 struct in6_addr *in6; 856 857 in6 = &L3_ADDR_SIN6(ln)->sin6_addr; 858 859 /* 860 * Lock to protect the default router list. 861 * XXX: this might be unnecessary, since this function 862 * is only called under the network software interrupt 863 * context. However, we keep it just for safety. 864 */ 865 dr = defrouter_lookup(in6, ln->lle_tbl->llt_ifp); 866 if (dr) 867 defrtrlist_del(dr); 868 else if (ND_IFINFO(ln->lle_tbl->llt_ifp)->flags & 869 ND6_IFF_ACCEPT_RTADV) { 870 /* 871 * Even if the neighbor is not in the default 872 * router list, the neighbor may be used 873 * as a next hop for some destinations 874 * (e.g. redirect case). So we must 875 * call rt6_flush explicitly. 876 */ 877 rt6_flush(&ip6->ip6_src, ifp); 878 } 879 } 880 ln->ln_router = is_router; 881 } 882 /* XXX - QL 883 * Does this matter? 884 * rt->rt_flags &= ~RTF_REJECT; 885 */ 886 ln->la_asked = 0; 887 if (ln->la_hold) { 888 struct mbuf *m_hold, *m_hold_next; 889 890 /* 891 * reset the la_hold in advance, to explicitly 892 * prevent a la_hold lookup in nd6_output() 893 * (wouldn't happen, though...) 894 */ 895 for (m_hold = ln->la_hold, ln->la_hold = NULL; 896 m_hold; m_hold = m_hold_next) { 897 m_hold_next = m_hold->m_nextpkt; 898 m_hold->m_nextpkt = NULL; 899 /* 900 * we assume ifp is not a loopback here, so just set 901 * the 2nd argument as the 1st one. 902 */ 903 904 if (send_sendso_input_hook != NULL) { 905 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 906 sizeof(unsigned short), M_NOWAIT); 907 if (mtag == NULL) 908 goto bad; 909 m_tag_prepend(m, mtag); 910 } 911 912 nd6_output_lle(ifp, ifp, m_hold, L3_ADDR_SIN6(ln), NULL, ln, &chain); 913 } 914 } 915 freeit: 916 if (ln != NULL) { 917 if (chain) 918 memcpy(&sin6, L3_ADDR_SIN6(ln), sizeof(sin6)); 919 LLE_WUNLOCK(ln); 920 921 if (chain) 922 nd6_output_flush(ifp, ifp, chain, &sin6, NULL); 923 } 924 if (checklink) 925 pfxlist_onlink_check(); 926 927 m_freem(m); 928 return; 929 930 bad: 931 if (ln != NULL) 932 LLE_WUNLOCK(ln); 933 934 ICMP6STAT_INC(icp6s_badna); 935 m_freem(m); 936} 937 938/* 939 * Neighbor advertisement output handling. 940 * 941 * Based on RFC 2461 942 * 943 * the following items are not implemented yet: 944 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 945 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 946 * 947 * tlladdr - 1 if include target link-layer address 948 * sdl0 - sockaddr_dl (= proxy NA) or NULL 949 */ 950static void 951nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 952 const struct in6_addr *taddr6, u_long flags, int tlladdr, 953 struct sockaddr *sdl0, u_int fibnum) 954{ 955 struct mbuf *m; 956 struct m_tag *mtag; 957 struct ifnet *oifp; 958 struct ip6_hdr *ip6; 959 struct nd_neighbor_advert *nd_na; 960 struct ip6_moptions im6o; 961 struct in6_addr src, daddr6; 962 struct sockaddr_in6 dst_sa; 963 int icmp6len, maxlen, error; 964 caddr_t mac = NULL; 965 struct route_in6 ro; 966 967 bzero(&ro, sizeof(ro)); 968 969 daddr6 = *daddr6_0; /* make a local copy for modification */ 970 971 /* estimate the size of message */ 972 maxlen = sizeof(*ip6) + sizeof(*nd_na); 973 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 974 if (max_linkhdr + maxlen >= MCLBYTES) { 975#ifdef DIAGNOSTIC 976 printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES " 977 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES); 978#endif 979 return; 980 } 981 982 if (max_linkhdr + maxlen > MHLEN) 983 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 984 else 985 m = m_gethdr(M_NOWAIT, MT_DATA); 986 if (m == NULL) 987 return; 988 M_SETFIB(m, fibnum); 989 990 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 991 m->m_flags |= M_MCAST; 992 im6o.im6o_multicast_ifp = ifp; 993 im6o.im6o_multicast_hlim = 255; 994 im6o.im6o_multicast_loop = 0; 995 } 996 997 icmp6len = sizeof(*nd_na); 998 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 999 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 1000 1001 /* fill neighbor advertisement packet */ 1002 ip6 = mtod(m, struct ip6_hdr *); 1003 ip6->ip6_flow = 0; 1004 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 1005 ip6->ip6_vfc |= IPV6_VERSION; 1006 ip6->ip6_nxt = IPPROTO_ICMPV6; 1007 ip6->ip6_hlim = 255; 1008 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 1009 /* reply to DAD */ 1010 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 1011 daddr6.s6_addr16[1] = 0; 1012 daddr6.s6_addr32[1] = 0; 1013 daddr6.s6_addr32[2] = 0; 1014 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 1015 if (in6_setscope(&daddr6, ifp, NULL)) 1016 goto bad; 1017 1018 flags &= ~ND_NA_FLAG_SOLICITED; 1019 } 1020 ip6->ip6_dst = daddr6; 1021 bzero(&dst_sa, sizeof(struct sockaddr_in6)); 1022 dst_sa.sin6_family = AF_INET6; 1023 dst_sa.sin6_len = sizeof(struct sockaddr_in6); 1024 dst_sa.sin6_addr = daddr6; 1025 1026 /* 1027 * Select a source whose scope is the same as that of the dest. 1028 */ 1029 bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa)); 1030 oifp = ifp; 1031 error = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, &oifp, &src); 1032 if (error) { 1033 char ip6buf[INET6_ADDRSTRLEN]; 1034 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1035 "determined: dst=%s, error=%d\n", 1036 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), error)); 1037 goto bad; 1038 } 1039 ip6->ip6_src = src; 1040 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1041 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1042 nd_na->nd_na_code = 0; 1043 nd_na->nd_na_target = *taddr6; 1044 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1045 1046 /* 1047 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1048 * see nd6_ns_input() for details. 1049 * Basically, if NS packet is sent to unicast/anycast addr, 1050 * target lladdr option SHOULD NOT be included. 1051 */ 1052 if (tlladdr) { 1053 /* 1054 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1055 * lladdr in sdl0. If we are not proxying (sending NA for 1056 * my address) use lladdr configured for the interface. 1057 */ 1058 if (sdl0 == NULL) { 1059 if (ifp->if_carp) 1060 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1061 if (mac == NULL) 1062 mac = nd6_ifptomac(ifp); 1063 } else if (sdl0->sa_family == AF_LINK) { 1064 struct sockaddr_dl *sdl; 1065 sdl = (struct sockaddr_dl *)sdl0; 1066 if (sdl->sdl_alen == ifp->if_addrlen) 1067 mac = LLADDR(sdl); 1068 } 1069 } 1070 if (tlladdr && mac) { 1071 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1072 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1073 1074 /* roundup to 8 bytes alignment! */ 1075 optlen = (optlen + 7) & ~7; 1076 1077 m->m_pkthdr.len += optlen; 1078 m->m_len += optlen; 1079 icmp6len += optlen; 1080 bzero((caddr_t)nd_opt, optlen); 1081 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1082 nd_opt->nd_opt_len = optlen >> 3; 1083 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1084 } else 1085 flags &= ~ND_NA_FLAG_OVERRIDE; 1086 1087 ip6->ip6_plen = htons((u_short)icmp6len); 1088 nd_na->nd_na_flags_reserved = flags; 1089 nd_na->nd_na_cksum = 0; 1090 nd_na->nd_na_cksum = 1091 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1092 1093 if (send_sendso_input_hook != NULL) { 1094 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1095 sizeof(unsigned short), M_NOWAIT); 1096 if (mtag == NULL) 1097 goto bad; 1098 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1099 m_tag_prepend(m, mtag); 1100 } 1101 1102 ip6_output(m, NULL, &ro, 0, &im6o, NULL, NULL); 1103 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1104 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1105 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1106 1107 /* We don't cache this route. */ 1108 RO_RTFREE(&ro); 1109 1110 return; 1111 1112 bad: 1113 if (ro.ro_rt) { 1114 RTFREE(ro.ro_rt); 1115 } 1116 m_freem(m); 1117 return; 1118} 1119 1120#ifndef BURN_BRIDGES 1121void 1122nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1123 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1124 struct sockaddr *sdl0) 1125{ 1126 1127 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1128 RT_DEFAULT_FIB); 1129} 1130#endif 1131 1132caddr_t 1133nd6_ifptomac(struct ifnet *ifp) 1134{ 1135 switch (ifp->if_type) { 1136 case IFT_ARCNET: 1137 case IFT_ETHER: 1138 case IFT_FDDI: 1139 case IFT_IEEE1394: 1140#ifdef IFT_L2VLAN 1141 case IFT_L2VLAN: 1142#endif 1143#ifdef IFT_IEEE80211 1144 case IFT_IEEE80211: 1145#endif 1146 case IFT_INFINIBAND: 1147 case IFT_BRIDGE: 1148 case IFT_ISO88025: 1149 return IF_LLADDR(ifp); 1150 default: 1151 return NULL; 1152 } 1153} 1154 1155struct dadq { 1156 TAILQ_ENTRY(dadq) dad_list; 1157 struct ifaddr *dad_ifa; 1158 int dad_count; /* max NS to send */ 1159 int dad_ns_tcount; /* # of trials to send NS */ 1160 int dad_ns_ocount; /* NS sent so far */ 1161 int dad_ns_icount; 1162 int dad_na_icount; 1163 struct callout dad_timer_ch; 1164 struct vnet *dad_vnet; 1165}; 1166 1167static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq); 1168VNET_DEFINE(int, dad_init) = 0; 1169#define V_dadq VNET(dadq) 1170#define V_dad_init VNET(dad_init) 1171 1172static struct dadq * 1173nd6_dad_find(struct ifaddr *ifa) 1174{ 1175 struct dadq *dp; 1176 1177 TAILQ_FOREACH(dp, &V_dadq, dad_list) 1178 if (dp->dad_ifa == ifa) 1179 return (dp); 1180 1181 return (NULL); 1182} 1183 1184static void 1185nd6_dad_starttimer(struct dadq *dp, int ticks) 1186{ 1187 1188 callout_reset(&dp->dad_timer_ch, ticks, 1189 (void (*)(void *))nd6_dad_timer, (void *)dp); 1190} 1191 1192static void 1193nd6_dad_stoptimer(struct dadq *dp) 1194{ 1195 1196 callout_stop(&dp->dad_timer_ch); 1197} 1198 1199/* 1200 * Start Duplicate Address Detection (DAD) for specified interface address. 1201 */ 1202void 1203nd6_dad_start(struct ifaddr *ifa, int delay) 1204{ 1205 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1206 struct dadq *dp; 1207 char ip6buf[INET6_ADDRSTRLEN]; 1208 1209 if (!V_dad_init) { 1210 TAILQ_INIT(&V_dadq); 1211 V_dad_init++; 1212 } 1213 1214 /* 1215 * If we don't need DAD, don't do it. 1216 * There are several cases: 1217 * - DAD is disabled (ip6_dad_count == 0) 1218 * - the interface address is anycast 1219 */ 1220 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1221 log(LOG_DEBUG, 1222 "nd6_dad_start: called with non-tentative address " 1223 "%s(%s)\n", 1224 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1225 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1226 return; 1227 } 1228 if (ia->ia6_flags & IN6_IFF_ANYCAST) { 1229 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1230 return; 1231 } 1232 if (!V_ip6_dad_count) { 1233 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1234 return; 1235 } 1236 if (ifa->ifa_ifp == NULL) 1237 panic("nd6_dad_start: ifa->ifa_ifp == NULL"); 1238 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) { 1239 return; 1240 } 1241 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) 1242 return; 1243 if (nd6_dad_find(ifa) != NULL) { 1244 /* DAD already in progress */ 1245 return; 1246 } 1247 1248 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT); 1249 if (dp == NULL) { 1250 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1251 "%s(%s)\n", 1252 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1253 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1254 return; 1255 } 1256 bzero(dp, sizeof(*dp)); 1257 callout_init(&dp->dad_timer_ch, 0); 1258#ifdef VIMAGE 1259 dp->dad_vnet = curvnet; 1260#endif 1261 TAILQ_INSERT_TAIL(&V_dadq, (struct dadq *)dp, dad_list); 1262 1263 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1264 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1265 1266 /* 1267 * Send NS packet for DAD, ip6_dad_count times. 1268 * Note that we must delay the first transmission, if this is the 1269 * first packet to be sent from the interface after interface 1270 * (re)initialization. 1271 */ 1272 dp->dad_ifa = ifa; 1273 ifa_ref(ifa); /* just for safety */ 1274 dp->dad_count = V_ip6_dad_count; 1275 dp->dad_ns_icount = dp->dad_na_icount = 0; 1276 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1277 if (delay == 0) { 1278 nd6_dad_ns_output(dp, ifa); 1279 nd6_dad_starttimer(dp, 1280 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1281 } else { 1282 nd6_dad_starttimer(dp, delay); 1283 } 1284} 1285 1286/* 1287 * terminate DAD unconditionally. used for address removals. 1288 */ 1289void 1290nd6_dad_stop(struct ifaddr *ifa) 1291{ 1292 struct dadq *dp; 1293 1294 if (!V_dad_init) 1295 return; 1296 dp = nd6_dad_find(ifa); 1297 if (!dp) { 1298 /* DAD wasn't started yet */ 1299 return; 1300 } 1301 1302 nd6_dad_stoptimer(dp); 1303 1304 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list); 1305 free(dp, M_IP6NDP); 1306 dp = NULL; 1307 ifa_free(ifa); 1308} 1309 1310static void 1311nd6_dad_timer(struct dadq *dp) 1312{ 1313 CURVNET_SET(dp->dad_vnet); 1314 struct ifaddr *ifa = dp->dad_ifa; 1315 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1316 char ip6buf[INET6_ADDRSTRLEN]; 1317 1318 /* Sanity check */ 1319 if (ia == NULL) { 1320 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n"); 1321 goto done; 1322 } 1323 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1324 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1325 "%s(%s)\n", 1326 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1327 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1328 goto done; 1329 } 1330 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1331 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1332 "%s(%s)\n", 1333 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1334 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1335 goto done; 1336 } 1337 1338 /* timeouted with IFF_{RUNNING,UP} check */ 1339 if (dp->dad_ns_tcount > V_dad_maxtry) { 1340 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n", 1341 if_name(ifa->ifa_ifp))); 1342 1343 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list); 1344 free(dp, M_IP6NDP); 1345 dp = NULL; 1346 ifa_free(ifa); 1347 goto done; 1348 } 1349 1350 /* Need more checks? */ 1351 if (dp->dad_ns_ocount < dp->dad_count) { 1352 /* 1353 * We have more NS to go. Send NS packet for DAD. 1354 */ 1355 nd6_dad_ns_output(dp, ifa); 1356 nd6_dad_starttimer(dp, 1357 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1358 } else { 1359 /* 1360 * We have transmitted sufficient number of DAD packets. 1361 * See what we've got. 1362 */ 1363 int duplicate; 1364 1365 duplicate = 0; 1366 1367 if (dp->dad_na_icount) { 1368 /* 1369 * the check is in nd6_dad_na_input(), 1370 * but just in case 1371 */ 1372 duplicate++; 1373 } 1374 1375 if (dp->dad_ns_icount) { 1376 /* We've seen NS, means DAD has failed. */ 1377 duplicate++; 1378 } 1379 1380 if (duplicate) { 1381 /* (*dp) will be freed in nd6_dad_duplicated() */ 1382 dp = NULL; 1383 nd6_dad_duplicated(ifa); 1384 } else { 1385 /* 1386 * We are done with DAD. No NA came, no NS came. 1387 * No duplicate address found. 1388 */ 1389 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1390 1391 nd6log((LOG_DEBUG, 1392 "%s: DAD complete for %s - no duplicates found\n", 1393 if_name(ifa->ifa_ifp), 1394 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1395 1396 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list); 1397 free(dp, M_IP6NDP); 1398 dp = NULL; 1399 ifa_free(ifa); 1400 } 1401 } 1402 1403done: 1404 CURVNET_RESTORE(); 1405} 1406 1407void 1408nd6_dad_duplicated(struct ifaddr *ifa) 1409{ 1410 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1411 struct ifnet *ifp; 1412 struct dadq *dp; 1413 char ip6buf[INET6_ADDRSTRLEN]; 1414 1415 dp = nd6_dad_find(ifa); 1416 if (dp == NULL) { 1417 log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n"); 1418 return; 1419 } 1420 1421 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1422 "NS in/out=%d/%d, NA in=%d\n", 1423 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1424 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount); 1425 1426 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1427 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1428 1429 /* We are done with DAD, with duplicate address found. (failure) */ 1430 nd6_dad_stoptimer(dp); 1431 1432 ifp = ifa->ifa_ifp; 1433 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1434 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1435 log(LOG_ERR, "%s: manual intervention required\n", 1436 if_name(ifp)); 1437 1438 /* 1439 * If the address is a link-local address formed from an interface 1440 * identifier based on the hardware address which is supposed to be 1441 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1442 * operation on the interface SHOULD be disabled. 1443 * [RFC 4862, Section 5.4.5] 1444 */ 1445 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1446 struct in6_addr in6; 1447 1448 /* 1449 * To avoid over-reaction, we only apply this logic when we are 1450 * very sure that hardware addresses are supposed to be unique. 1451 */ 1452 switch (ifp->if_type) { 1453 case IFT_ETHER: 1454 case IFT_FDDI: 1455 case IFT_ATM: 1456 case IFT_IEEE1394: 1457#ifdef IFT_IEEE80211 1458 case IFT_IEEE80211: 1459#endif 1460 case IFT_INFINIBAND: 1461 in6 = ia->ia_addr.sin6_addr; 1462 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1463 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1464 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1465 log(LOG_ERR, "%s: possible hardware address " 1466 "duplication detected, disable IPv6\n", 1467 if_name(ifp)); 1468 } 1469 break; 1470 } 1471 } 1472 1473 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list); 1474 free(dp, M_IP6NDP); 1475 dp = NULL; 1476 ifa_free(ifa); 1477} 1478 1479static void 1480nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa) 1481{ 1482 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1483 struct ifnet *ifp = ifa->ifa_ifp; 1484 1485 dp->dad_ns_tcount++; 1486 if ((ifp->if_flags & IFF_UP) == 0) { 1487 return; 1488 } 1489 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1490 return; 1491 } 1492 1493 dp->dad_ns_ocount++; 1494 nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1); 1495} 1496 1497static void 1498nd6_dad_ns_input(struct ifaddr *ifa) 1499{ 1500 struct in6_ifaddr *ia; 1501 struct ifnet *ifp; 1502 const struct in6_addr *taddr6; 1503 struct dadq *dp; 1504 int duplicate; 1505 1506 if (ifa == NULL) 1507 panic("ifa == NULL in nd6_dad_ns_input"); 1508 1509 ia = (struct in6_ifaddr *)ifa; 1510 ifp = ifa->ifa_ifp; 1511 taddr6 = &ia->ia_addr.sin6_addr; 1512 duplicate = 0; 1513 dp = nd6_dad_find(ifa); 1514 1515 /* Quickhack - completely ignore DAD NS packets */ 1516 if (V_dad_ignore_ns) { 1517 char ip6buf[INET6_ADDRSTRLEN]; 1518 nd6log((LOG_INFO, 1519 "nd6_dad_ns_input: ignoring DAD NS packet for " 1520 "address %s(%s)\n", ip6_sprintf(ip6buf, taddr6), 1521 if_name(ifa->ifa_ifp))); 1522 return; 1523 } 1524 1525 /* 1526 * if I'm yet to start DAD, someone else started using this address 1527 * first. I have a duplicate and you win. 1528 */ 1529 if (dp == NULL || dp->dad_ns_ocount == 0) 1530 duplicate++; 1531 1532 /* XXX more checks for loopback situation - see nd6_dad_timer too */ 1533 1534 if (duplicate) { 1535 dp = NULL; /* will be freed in nd6_dad_duplicated() */ 1536 nd6_dad_duplicated(ifa); 1537 } else { 1538 /* 1539 * not sure if I got a duplicate. 1540 * increment ns count and see what happens. 1541 */ 1542 if (dp) 1543 dp->dad_ns_icount++; 1544 } 1545} 1546 1547static void 1548nd6_dad_na_input(struct ifaddr *ifa) 1549{ 1550 struct dadq *dp; 1551 1552 if (ifa == NULL) 1553 panic("ifa == NULL in nd6_dad_na_input"); 1554 1555 dp = nd6_dad_find(ifa); 1556 if (dp) 1557 dp->dad_na_icount++; 1558 1559 /* remove the address. */ 1560 nd6_dad_duplicated(ifa); 1561} 1562