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("$FreeBSD$"); 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 #define L3_ADDR_SIN6(le) ((struct sockaddr_in6 *) L3_ADDR(le)) 72 #include <netinet6/in6_var.h> 73 #include <netinet6/in6_ifattach.h> 74 #include <netinet/ip6.h> 75 #include <netinet6/ip6_var.h> 76 #include <netinet6/scope6_var.h> 77 #include <netinet6/nd6.h> 78 #include <netinet/icmp6.h> 79 #include <netinet/ip_carp.h> 80 #include <netinet6/send.h> 81 82 #define SDL(s) ((struct sockaddr_dl *)s) 83 84 struct dadq; 85 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *); 86 static void nd6_dad_add(struct dadq *dp); 87 static void nd6_dad_del(struct dadq *dp); 88 static void nd6_dad_rele(struct dadq *); 89 static void nd6_dad_starttimer(struct dadq *, int); 90 static void nd6_dad_stoptimer(struct dadq *); 91 static void nd6_dad_timer(struct dadq *); 92 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *); 93 static void nd6_dad_ns_output(struct dadq *, struct ifaddr *); 94 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *); 95 static void nd6_dad_na_input(struct ifaddr *); 96 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 97 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 98 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *, 99 const struct in6_addr *, struct llentry *, uint8_t *, u_int); 100 101 static VNET_DEFINE(int, dad_enhanced) = 1; 102 #define V_dad_enhanced VNET(dad_enhanced) 103 104 SYSCTL_DECL(_net_inet6_ip6); 105 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW, 106 &VNET_NAME(dad_enhanced), 0, 107 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD."); 108 109 static VNET_DEFINE(int, dad_maxtry) = 15; /* max # of *tries* to 110 transmit DAD packet */ 111 #define V_dad_maxtry VNET(dad_maxtry) 112 113 /* 114 * Input a Neighbor Solicitation Message. 115 * 116 * Based on RFC 2461 117 * Based on RFC 2462 (duplicate address detection) 118 */ 119 void 120 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 121 { 122 struct ifnet *ifp = m->m_pkthdr.rcvif; 123 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 124 struct nd_neighbor_solicit *nd_ns; 125 struct in6_addr saddr6 = ip6->ip6_src; 126 struct in6_addr daddr6 = ip6->ip6_dst; 127 struct in6_addr taddr6; 128 struct in6_addr myaddr6; 129 char *lladdr = NULL; 130 struct ifaddr *ifa = NULL; 131 int lladdrlen = 0; 132 int anycast = 0, proxy = 0, tentative = 0; 133 int tlladdr; 134 int rflag; 135 union nd_opts ndopts; 136 struct sockaddr_dl proxydl; 137 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 138 139 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 140 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 141 rflag = 0; 142 #ifndef PULLDOWN_TEST 143 IP6_EXTHDR_CHECK(m, off, icmp6len,); 144 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 145 #else 146 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); 147 if (nd_ns == NULL) { 148 ICMP6STAT_INC(icp6s_tooshort); 149 return; 150 } 151 #endif 152 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ 153 taddr6 = nd_ns->nd_ns_target; 154 if (in6_setscope(&taddr6, ifp, NULL) != 0) 155 goto bad; 156 157 if (ip6->ip6_hlim != 255) { 158 nd6log((LOG_ERR, 159 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 160 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 161 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 162 goto bad; 163 } 164 165 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 166 /* dst has to be a solicited node multicast address. */ 167 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 168 /* don't check ifindex portion */ 169 daddr6.s6_addr32[1] == 0 && 170 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 171 daddr6.s6_addr8[12] == 0xff) { 172 ; /* good */ 173 } else { 174 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 175 "(wrong ip6 dst)\n")); 176 goto bad; 177 } 178 } else if (!V_nd6_onlink_ns_rfc4861) { 179 struct sockaddr_in6 src_sa6; 180 181 /* 182 * According to recent IETF discussions, it is not a good idea 183 * to accept a NS from an address which would not be deemed 184 * to be a neighbor otherwise. This point is expected to be 185 * clarified in future revisions of the specification. 186 */ 187 bzero(&src_sa6, sizeof(src_sa6)); 188 src_sa6.sin6_family = AF_INET6; 189 src_sa6.sin6_len = sizeof(src_sa6); 190 src_sa6.sin6_addr = saddr6; 191 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 192 nd6log((LOG_INFO, "nd6_ns_input: " 193 "NS packet from non-neighbor\n")); 194 goto bad; 195 } 196 } 197 198 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 199 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 200 goto bad; 201 } 202 203 icmp6len -= sizeof(*nd_ns); 204 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 205 if (nd6_options(&ndopts) < 0) { 206 nd6log((LOG_INFO, 207 "nd6_ns_input: invalid ND option, ignored\n")); 208 /* nd6_options have incremented stats */ 209 goto freeit; 210 } 211 212 if (ndopts.nd_opts_src_lladdr) { 213 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 214 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 215 } 216 217 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 218 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 219 "(link-layer address option)\n")); 220 goto bad; 221 } 222 223 /* 224 * Attaching target link-layer address to the NA? 225 * (RFC 2461 7.2.4) 226 * 227 * NS IP dst is unicast/anycast MUST NOT add 228 * NS IP dst is solicited-node multicast MUST add 229 * 230 * In implementation, we add target link-layer address by default. 231 * We do not add one in MUST NOT cases. 232 */ 233 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 234 tlladdr = 0; 235 else 236 tlladdr = 1; 237 238 /* 239 * Target address (taddr6) must be either: 240 * (1) Valid unicast/anycast address for my receiving interface, 241 * (2) Unicast address for which I'm offering proxy service, or 242 * (3) "tentative" address on which DAD is being performed. 243 */ 244 /* (1) and (3) check. */ 245 if (ifp->if_carp) 246 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 247 else 248 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 249 250 /* (2) check. */ 251 if (ifa == NULL) { 252 struct route_in6 ro; 253 int need_proxy; 254 255 bzero(&ro, sizeof(ro)); 256 ro.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 257 ro.ro_dst.sin6_family = AF_INET6; 258 ro.ro_dst.sin6_addr = taddr6; 259 260 /* Always use the default FIB. */ 261 #ifdef RADIX_MPATH 262 rtalloc_mpath_fib((struct route *)&ro, ntohl(taddr6.s6_addr32[3]), 263 RT_DEFAULT_FIB); 264 #else 265 in6_rtalloc(&ro, RT_DEFAULT_FIB); 266 #endif 267 need_proxy = (ro.ro_rt && 268 (ro.ro_rt->rt_flags & RTF_ANNOUNCE) != 0 && 269 ro.ro_rt->rt_gateway->sa_family == AF_LINK); 270 if (ro.ro_rt != NULL) { 271 if (need_proxy) 272 proxydl = *SDL(ro.ro_rt->rt_gateway); 273 RTFREE(ro.ro_rt); 274 } 275 if (need_proxy) { 276 /* 277 * proxy NDP for single entry 278 */ 279 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 280 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 281 if (ifa) 282 proxy = 1; 283 } 284 } 285 if (ifa == NULL) { 286 /* 287 * We've got an NS packet, and we don't have that adddress 288 * assigned for us. We MUST silently ignore it. 289 * See RFC2461 7.2.3. 290 */ 291 goto freeit; 292 } 293 myaddr6 = *IFA_IN6(ifa); 294 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 295 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 296 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 297 goto freeit; 298 299 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 300 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 301 "(if %d, NS packet %d)\n", 302 ip6_sprintf(ip6bufs, &taddr6), 303 ifp->if_addrlen, lladdrlen - 2)); 304 goto bad; 305 } 306 307 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 308 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 309 ip6_sprintf(ip6bufs, &saddr6))); 310 goto freeit; 311 } 312 313 /* 314 * We have neighbor solicitation packet, with target address equals to 315 * one of my tentative address. 316 * 317 * src addr how to process? 318 * --- --- 319 * multicast of course, invalid (rejected in ip6_input) 320 * unicast somebody is doing address resolution -> ignore 321 * unspec dup address detection 322 * 323 * The processing is defined in RFC 2462. 324 */ 325 if (tentative) { 326 /* 327 * If source address is unspecified address, it is for 328 * duplicate address detection. 329 * 330 * If not, the packet is for addess resolution; 331 * silently ignore it. 332 */ 333 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 334 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 335 336 goto freeit; 337 } 338 339 /* 340 * If the source address is unspecified address, entries must not 341 * be created or updated. 342 * It looks that sender is performing DAD. Output NA toward 343 * all-node multicast address, to tell the sender that I'm using 344 * the address. 345 * S bit ("solicited") must be zero. 346 */ 347 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 348 struct in6_addr in6_all; 349 350 in6_all = in6addr_linklocal_allnodes; 351 if (in6_setscope(&in6_all, ifp, NULL) != 0) 352 goto bad; 353 nd6_na_output_fib(ifp, &in6_all, &taddr6, 354 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 355 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 356 M_GETFIB(m)); 357 goto freeit; 358 } 359 360 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 361 ND_NEIGHBOR_SOLICIT, 0); 362 363 nd6_na_output_fib(ifp, &saddr6, &taddr6, 364 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 365 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 366 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 367 freeit: 368 if (ifa != NULL) 369 ifa_free(ifa); 370 m_freem(m); 371 return; 372 373 bad: 374 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 375 ip6_sprintf(ip6bufs, &saddr6))); 376 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 377 ip6_sprintf(ip6bufs, &daddr6))); 378 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 379 ip6_sprintf(ip6bufs, &taddr6))); 380 ICMP6STAT_INC(icp6s_badns); 381 if (ifa != NULL) 382 ifa_free(ifa); 383 m_freem(m); 384 } 385 386 /* 387 * Output a Neighbor Solicitation Message. Caller specifies: 388 * - ICMP6 header source IP6 address 389 * - ND6 header target IP6 address 390 * - ND6 header source datalink address 391 * 392 * Based on RFC 2461 393 * Based on RFC 2462 (duplicate address detection) 394 * 395 * ln - for source address determination 396 * nonce - If non-NULL, NS is used for duplicate address detection and 397 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 398 */ 399 static void 400 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6, 401 const struct in6_addr *taddr6, struct llentry *ln, uint8_t *nonce, 402 u_int fibnum) 403 { 404 struct mbuf *m; 405 struct m_tag *mtag; 406 struct ip6_hdr *ip6; 407 struct nd_neighbor_solicit *nd_ns; 408 struct ip6_moptions im6o; 409 int icmp6len; 410 int maxlen; 411 caddr_t mac; 412 struct route_in6 ro; 413 414 if (IN6_IS_ADDR_MULTICAST(taddr6)) 415 return; 416 417 /* estimate the size of message */ 418 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 419 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 420 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 421 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 422 __func__, max_linkhdr, maxlen, MCLBYTES)); 423 424 if (max_linkhdr + maxlen > MHLEN) 425 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 426 else 427 m = m_gethdr(M_NOWAIT, MT_DATA); 428 if (m == NULL) 429 return; 430 M_SETFIB(m, fibnum); 431 432 bzero(&ro, sizeof(ro)); 433 434 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 435 m->m_flags |= M_MCAST; 436 im6o.im6o_multicast_ifp = ifp; 437 im6o.im6o_multicast_hlim = 255; 438 im6o.im6o_multicast_loop = 0; 439 } 440 441 icmp6len = sizeof(*nd_ns); 442 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 443 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 444 445 /* fill neighbor solicitation packet */ 446 ip6 = mtod(m, struct ip6_hdr *); 447 ip6->ip6_flow = 0; 448 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 449 ip6->ip6_vfc |= IPV6_VERSION; 450 /* ip6->ip6_plen will be set later */ 451 ip6->ip6_nxt = IPPROTO_ICMPV6; 452 ip6->ip6_hlim = 255; 453 if (daddr6) 454 ip6->ip6_dst = *daddr6; 455 else { 456 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 457 ip6->ip6_dst.s6_addr16[1] = 0; 458 ip6->ip6_dst.s6_addr32[1] = 0; 459 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 460 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 461 ip6->ip6_dst.s6_addr8[12] = 0xff; 462 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 463 goto bad; 464 } 465 if (nonce == NULL) { 466 struct ifaddr *ifa; 467 468 /* 469 * RFC2461 7.2.2: 470 * "If the source address of the packet prompting the 471 * solicitation is the same as one of the addresses assigned 472 * to the outgoing interface, that address SHOULD be placed 473 * in the IP Source Address of the outgoing solicitation. 474 * Otherwise, any one of the addresses assigned to the 475 * interface should be used." 476 * 477 * We use the source address for the prompting packet 478 * (saddr6), if: 479 * - saddr6 is given from the caller (by giving "ln"), and 480 * - saddr6 belongs to the outgoing interface. 481 * Otherwise, we perform the source address selection as usual. 482 */ 483 struct in6_addr *hsrc; 484 485 hsrc = NULL; 486 if (ln != NULL) { 487 LLE_RLOCK(ln); 488 if (ln->la_hold != NULL) { 489 struct ip6_hdr *hip6; /* hold ip6 */ 490 491 /* 492 * assuming every packet in la_hold has the same IP 493 * header 494 */ 495 hip6 = mtod(ln->la_hold, struct ip6_hdr *); 496 /* XXX pullup? */ 497 if (sizeof(*hip6) < ln->la_hold->m_len) { 498 ip6->ip6_src = hip6->ip6_src; 499 hsrc = &hip6->ip6_src; 500 } 501 } 502 LLE_RUNLOCK(ln); 503 } 504 if (hsrc && (ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, 505 hsrc)) != NULL) { 506 /* ip6_src set already. */ 507 ifa_free(ifa); 508 } else { 509 int error; 510 struct sockaddr_in6 dst_sa; 511 struct in6_addr src_in; 512 struct ifnet *oifp; 513 514 bzero(&dst_sa, sizeof(dst_sa)); 515 dst_sa.sin6_family = AF_INET6; 516 dst_sa.sin6_len = sizeof(dst_sa); 517 dst_sa.sin6_addr = ip6->ip6_dst; 518 519 oifp = ifp; 520 error = in6_selectsrc(&dst_sa, NULL, 521 NULL, &ro, NULL, &oifp, &src_in); 522 if (error) { 523 char ip6buf[INET6_ADDRSTRLEN]; 524 nd6log((LOG_DEBUG, "%s: source can't be " 525 "determined: dst=%s, error=%d\n", __func__, 526 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), 527 error)); 528 goto bad; 529 } 530 ip6->ip6_src = src_in; 531 } 532 } else { 533 /* 534 * Source address for DAD packet must always be IPv6 535 * unspecified address. (0::0) 536 * We actually don't have to 0-clear the address (we did it 537 * above), but we do so here explicitly to make the intention 538 * clearer. 539 */ 540 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 541 } 542 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 543 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 544 nd_ns->nd_ns_code = 0; 545 nd_ns->nd_ns_reserved = 0; 546 nd_ns->nd_ns_target = *taddr6; 547 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 548 549 /* 550 * Add source link-layer address option. 551 * 552 * spec implementation 553 * --- --- 554 * DAD packet MUST NOT do not add the option 555 * there's no link layer address: 556 * impossible do not add the option 557 * there's link layer address: 558 * Multicast NS MUST add one add the option 559 * Unicast NS SHOULD add one add the option 560 */ 561 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 562 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 563 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 564 /* 8 byte alignments... */ 565 optlen = (optlen + 7) & ~7; 566 567 m->m_pkthdr.len += optlen; 568 m->m_len += optlen; 569 icmp6len += optlen; 570 bzero((caddr_t)nd_opt, optlen); 571 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 572 nd_opt->nd_opt_len = optlen >> 3; 573 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 574 } 575 /* 576 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 577 * This behavior is documented as Enhanced Duplicate Address 578 * Detection in draft-ietf-6man-enhanced-dad-13. 579 * net.inet6.ip6.dad_enhanced=0 disables this. 580 */ 581 if (V_dad_enhanced != 0 && nonce != NULL) { 582 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 583 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 584 /* 8-byte alignment is required. */ 585 optlen = (optlen + 7) & ~7; 586 587 m->m_pkthdr.len += optlen; 588 m->m_len += optlen; 589 icmp6len += optlen; 590 bzero((caddr_t)nd_opt, optlen); 591 nd_opt->nd_opt_type = ND_OPT_NONCE; 592 nd_opt->nd_opt_len = optlen >> 3; 593 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 594 } 595 ip6->ip6_plen = htons((u_short)icmp6len); 596 nd_ns->nd_ns_cksum = 0; 597 nd_ns->nd_ns_cksum = 598 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 599 600 if (send_sendso_input_hook != NULL) { 601 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 602 sizeof(unsigned short), M_NOWAIT); 603 if (mtag == NULL) 604 goto bad; 605 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 606 m_tag_prepend(m, mtag); 607 } 608 609 ip6_output(m, NULL, &ro, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 610 &im6o, NULL, NULL); 611 icmp6_ifstat_inc(ifp, ifs6_out_msg); 612 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 613 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 614 615 /* We don't cache this route. */ 616 RO_RTFREE(&ro); 617 618 return; 619 620 bad: 621 if (ro.ro_rt) { 622 RTFREE(ro.ro_rt); 623 } 624 m_freem(m); 625 return; 626 } 627 628 #ifndef BURN_BRIDGES 629 void 630 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6, 631 const struct in6_addr *taddr6, struct llentry *ln, uint8_t *nonce) 632 { 633 634 nd6_ns_output_fib(ifp, daddr6, taddr6, ln, nonce, RT_DEFAULT_FIB); 635 } 636 #endif 637 /* 638 * Neighbor advertisement input handling. 639 * 640 * Based on RFC 2461 641 * Based on RFC 2462 (duplicate address detection) 642 * 643 * the following items are not implemented yet: 644 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 645 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 646 */ 647 void 648 nd6_na_input(struct mbuf *m, int off, int icmp6len) 649 { 650 struct ifnet *ifp = m->m_pkthdr.rcvif; 651 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 652 struct nd_neighbor_advert *nd_na; 653 struct in6_addr daddr6 = ip6->ip6_dst; 654 struct in6_addr taddr6; 655 int flags; 656 int is_router; 657 int is_solicited; 658 int is_override; 659 char *lladdr = NULL; 660 int lladdrlen = 0; 661 int checklink = 0; 662 struct ifaddr *ifa; 663 struct llentry *ln = NULL; 664 union nd_opts ndopts; 665 struct mbuf *chain = NULL; 666 struct sockaddr_in6 sin6; 667 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 668 669 if (ip6->ip6_hlim != 255) { 670 nd6log((LOG_ERR, 671 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 672 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 673 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 674 goto bad; 675 } 676 677 #ifndef PULLDOWN_TEST 678 IP6_EXTHDR_CHECK(m, off, icmp6len,); 679 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 680 #else 681 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 682 if (nd_na == NULL) { 683 ICMP6STAT_INC(icp6s_tooshort); 684 return; 685 } 686 #endif 687 688 flags = nd_na->nd_na_flags_reserved; 689 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 690 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 691 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 692 memset(&sin6, 0, sizeof(sin6)); 693 694 taddr6 = nd_na->nd_na_target; 695 if (in6_setscope(&taddr6, ifp, NULL)) 696 goto bad; /* XXX: impossible */ 697 698 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 699 nd6log((LOG_ERR, 700 "nd6_na_input: invalid target address %s\n", 701 ip6_sprintf(ip6bufs, &taddr6))); 702 goto bad; 703 } 704 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 705 if (is_solicited) { 706 nd6log((LOG_ERR, 707 "nd6_na_input: a solicited adv is multicasted\n")); 708 goto bad; 709 } 710 711 icmp6len -= sizeof(*nd_na); 712 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 713 if (nd6_options(&ndopts) < 0) { 714 nd6log((LOG_INFO, 715 "nd6_na_input: invalid ND option, ignored\n")); 716 /* nd6_options have incremented stats */ 717 goto freeit; 718 } 719 720 if (ndopts.nd_opts_tgt_lladdr) { 721 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 722 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 723 } 724 725 /* 726 * This effectively disables the DAD check on a non-master CARP 727 * address. 728 */ 729 if (ifp->if_carp) 730 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 731 else 732 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 733 734 /* 735 * Target address matches one of my interface address. 736 * 737 * If my address is tentative, this means that there's somebody 738 * already using the same address as mine. This indicates DAD failure. 739 * This is defined in RFC 2462. 740 * 741 * Otherwise, process as defined in RFC 2461. 742 */ 743 if (ifa 744 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 745 nd6_dad_na_input(ifa); 746 ifa_free(ifa); 747 goto freeit; 748 } 749 750 /* Just for safety, maybe unnecessary. */ 751 if (ifa) { 752 ifa_free(ifa); 753 log(LOG_ERR, 754 "nd6_na_input: duplicate IP6 address %s\n", 755 ip6_sprintf(ip6bufs, &taddr6)); 756 goto freeit; 757 } 758 759 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 760 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 761 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 762 ifp->if_addrlen, lladdrlen - 2)); 763 goto bad; 764 } 765 766 /* 767 * If no neighbor cache entry is found, NA SHOULD silently be 768 * discarded. 769 */ 770 IF_AFDATA_RLOCK(ifp); 771 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 772 IF_AFDATA_RUNLOCK(ifp); 773 if (ln == NULL) { 774 goto freeit; 775 } 776 777 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 778 /* 779 * If the link-layer has address, and no lladdr option came, 780 * discard the packet. 781 */ 782 if (ifp->if_addrlen && lladdr == NULL) { 783 goto freeit; 784 } 785 786 /* 787 * Record link-layer address, and update the state. 788 */ 789 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen); 790 ln->la_flags |= LLE_VALID; 791 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 792 if (is_solicited) { 793 ln->ln_state = ND6_LLINFO_REACHABLE; 794 ln->ln_byhint = 0; 795 if (!ND6_LLINFO_PERMANENT(ln)) { 796 nd6_llinfo_settimer_locked(ln, 797 (long)ND_IFINFO(ln->lle_tbl->llt_ifp)->reachable * hz); 798 } 799 } else { 800 ln->ln_state = ND6_LLINFO_STALE; 801 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz); 802 } 803 if ((ln->ln_router = is_router) != 0) { 804 /* 805 * This means a router's state has changed from 806 * non-reachable to probably reachable, and might 807 * affect the status of associated prefixes.. 808 */ 809 checklink = 1; 810 } 811 } else { 812 int llchange; 813 814 /* 815 * Check if the link-layer address has changed or not. 816 */ 817 if (lladdr == NULL) 818 llchange = 0; 819 else { 820 if (ln->la_flags & LLE_VALID) { 821 if (bcmp(lladdr, &ln->ll_addr, ifp->if_addrlen)) 822 llchange = 1; 823 else 824 llchange = 0; 825 } else 826 llchange = 1; 827 } 828 829 /* 830 * This is VERY complex. Look at it with care. 831 * 832 * override solicit lladdr llchange action 833 * (L: record lladdr) 834 * 835 * 0 0 n -- (2c) 836 * 0 0 y n (2b) L 837 * 0 0 y y (1) REACHABLE->STALE 838 * 0 1 n -- (2c) *->REACHABLE 839 * 0 1 y n (2b) L *->REACHABLE 840 * 0 1 y y (1) REACHABLE->STALE 841 * 1 0 n -- (2a) 842 * 1 0 y n (2a) L 843 * 1 0 y y (2a) L *->STALE 844 * 1 1 n -- (2a) *->REACHABLE 845 * 1 1 y n (2a) L *->REACHABLE 846 * 1 1 y y (2a) L *->REACHABLE 847 */ 848 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 849 /* 850 * If state is REACHABLE, make it STALE. 851 * no other updates should be done. 852 */ 853 if (ln->ln_state == ND6_LLINFO_REACHABLE) { 854 ln->ln_state = ND6_LLINFO_STALE; 855 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz); 856 } 857 goto freeit; 858 } else if (is_override /* (2a) */ 859 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 860 || lladdr == NULL) { /* (2c) */ 861 /* 862 * Update link-local address, if any. 863 */ 864 if (lladdr != NULL) { 865 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen); 866 ln->la_flags |= LLE_VALID; 867 EVENTHANDLER_INVOKE(lle_event, ln, 868 LLENTRY_RESOLVED); 869 } 870 871 /* 872 * If solicited, make the state REACHABLE. 873 * If not solicited and the link-layer address was 874 * changed, make it STALE. 875 */ 876 if (is_solicited) { 877 ln->ln_state = ND6_LLINFO_REACHABLE; 878 ln->ln_byhint = 0; 879 if (!ND6_LLINFO_PERMANENT(ln)) { 880 nd6_llinfo_settimer_locked(ln, 881 (long)ND_IFINFO(ifp)->reachable * hz); 882 } 883 } else { 884 if (lladdr != NULL && llchange) { 885 ln->ln_state = ND6_LLINFO_STALE; 886 nd6_llinfo_settimer_locked(ln, 887 (long)V_nd6_gctimer * hz); 888 } 889 } 890 } 891 892 if (ln->ln_router && !is_router) { 893 /* 894 * The peer dropped the router flag. 895 * Remove the sender from the Default Router List and 896 * update the Destination Cache entries. 897 */ 898 struct nd_defrouter *dr; 899 struct in6_addr *in6; 900 901 in6 = &L3_ADDR_SIN6(ln)->sin6_addr; 902 903 /* 904 * Lock to protect the default router list. 905 * XXX: this might be unnecessary, since this function 906 * is only called under the network software interrupt 907 * context. However, we keep it just for safety. 908 */ 909 dr = defrouter_lookup(in6, ln->lle_tbl->llt_ifp); 910 if (dr) 911 defrtrlist_del(dr); 912 else if (ND_IFINFO(ln->lle_tbl->llt_ifp)->flags & 913 ND6_IFF_ACCEPT_RTADV) { 914 /* 915 * Even if the neighbor is not in the default 916 * router list, the neighbor may be used 917 * as a next hop for some destinations 918 * (e.g. redirect case). So we must 919 * call rt6_flush explicitly. 920 */ 921 rt6_flush(&ip6->ip6_src, ifp); 922 } 923 } 924 ln->ln_router = is_router; 925 } 926 /* XXX - QL 927 * Does this matter? 928 * rt->rt_flags &= ~RTF_REJECT; 929 */ 930 ln->la_asked = 0; 931 if (ln->la_hold != NULL) 932 nd6_grab_holdchain(ln, &chain, &sin6); 933 freeit: 934 if (ln != NULL) 935 LLE_WUNLOCK(ln); 936 937 if (chain != NULL) 938 nd6_flush_holdchain(ifp, ifp, chain, &sin6); 939 940 if (checklink) 941 pfxlist_onlink_check(); 942 943 m_freem(m); 944 return; 945 946 bad: 947 if (ln != NULL) 948 LLE_WUNLOCK(ln); 949 950 ICMP6STAT_INC(icp6s_badna); 951 m_freem(m); 952 } 953 954 /* 955 * Neighbor advertisement output handling. 956 * 957 * Based on RFC 2461 958 * 959 * the following items are not implemented yet: 960 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 961 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 962 * 963 * tlladdr - 1 if include target link-layer address 964 * sdl0 - sockaddr_dl (= proxy NA) or NULL 965 */ 966 static void 967 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 968 const struct in6_addr *taddr6, u_long flags, int tlladdr, 969 struct sockaddr *sdl0, u_int fibnum) 970 { 971 struct mbuf *m; 972 struct m_tag *mtag; 973 struct ifnet *oifp; 974 struct ip6_hdr *ip6; 975 struct nd_neighbor_advert *nd_na; 976 struct ip6_moptions im6o; 977 struct in6_addr src, daddr6; 978 struct sockaddr_in6 dst_sa; 979 int icmp6len, maxlen, error; 980 caddr_t mac = NULL; 981 struct route_in6 ro; 982 983 bzero(&ro, sizeof(ro)); 984 985 daddr6 = *daddr6_0; /* make a local copy for modification */ 986 987 /* estimate the size of message */ 988 maxlen = sizeof(*ip6) + sizeof(*nd_na); 989 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 990 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 991 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 992 __func__, max_linkhdr, maxlen, MCLBYTES)); 993 994 if (max_linkhdr + maxlen > MHLEN) 995 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 996 else 997 m = m_gethdr(M_NOWAIT, MT_DATA); 998 if (m == NULL) 999 return; 1000 M_SETFIB(m, fibnum); 1001 1002 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 1003 m->m_flags |= M_MCAST; 1004 im6o.im6o_multicast_ifp = ifp; 1005 im6o.im6o_multicast_hlim = 255; 1006 im6o.im6o_multicast_loop = 0; 1007 } 1008 1009 icmp6len = sizeof(*nd_na); 1010 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 1011 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 1012 1013 /* fill neighbor advertisement packet */ 1014 ip6 = mtod(m, struct ip6_hdr *); 1015 ip6->ip6_flow = 0; 1016 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 1017 ip6->ip6_vfc |= IPV6_VERSION; 1018 ip6->ip6_nxt = IPPROTO_ICMPV6; 1019 ip6->ip6_hlim = 255; 1020 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 1021 /* reply to DAD */ 1022 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 1023 daddr6.s6_addr16[1] = 0; 1024 daddr6.s6_addr32[1] = 0; 1025 daddr6.s6_addr32[2] = 0; 1026 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 1027 if (in6_setscope(&daddr6, ifp, NULL)) 1028 goto bad; 1029 1030 flags &= ~ND_NA_FLAG_SOLICITED; 1031 } 1032 ip6->ip6_dst = daddr6; 1033 bzero(&dst_sa, sizeof(struct sockaddr_in6)); 1034 dst_sa.sin6_family = AF_INET6; 1035 dst_sa.sin6_len = sizeof(struct sockaddr_in6); 1036 dst_sa.sin6_addr = daddr6; 1037 1038 /* 1039 * Select a source whose scope is the same as that of the dest. 1040 */ 1041 bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa)); 1042 oifp = ifp; 1043 error = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, &oifp, &src); 1044 if (error) { 1045 char ip6buf[INET6_ADDRSTRLEN]; 1046 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1047 "determined: dst=%s, error=%d\n", 1048 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), error)); 1049 goto bad; 1050 } 1051 ip6->ip6_src = src; 1052 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1053 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1054 nd_na->nd_na_code = 0; 1055 nd_na->nd_na_target = *taddr6; 1056 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1057 1058 /* 1059 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1060 * see nd6_ns_input() for details. 1061 * Basically, if NS packet is sent to unicast/anycast addr, 1062 * target lladdr option SHOULD NOT be included. 1063 */ 1064 if (tlladdr) { 1065 /* 1066 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1067 * lladdr in sdl0. If we are not proxying (sending NA for 1068 * my address) use lladdr configured for the interface. 1069 */ 1070 if (sdl0 == NULL) { 1071 if (ifp->if_carp) 1072 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1073 if (mac == NULL) 1074 mac = nd6_ifptomac(ifp); 1075 } else if (sdl0->sa_family == AF_LINK) { 1076 struct sockaddr_dl *sdl; 1077 sdl = (struct sockaddr_dl *)sdl0; 1078 if (sdl->sdl_alen == ifp->if_addrlen) 1079 mac = LLADDR(sdl); 1080 } 1081 } 1082 if (tlladdr && mac) { 1083 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1084 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1085 1086 /* roundup to 8 bytes alignment! */ 1087 optlen = (optlen + 7) & ~7; 1088 1089 m->m_pkthdr.len += optlen; 1090 m->m_len += optlen; 1091 icmp6len += optlen; 1092 bzero((caddr_t)nd_opt, optlen); 1093 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1094 nd_opt->nd_opt_len = optlen >> 3; 1095 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1096 } else 1097 flags &= ~ND_NA_FLAG_OVERRIDE; 1098 1099 ip6->ip6_plen = htons((u_short)icmp6len); 1100 nd_na->nd_na_flags_reserved = flags; 1101 nd_na->nd_na_cksum = 0; 1102 nd_na->nd_na_cksum = 1103 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1104 1105 if (send_sendso_input_hook != NULL) { 1106 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1107 sizeof(unsigned short), M_NOWAIT); 1108 if (mtag == NULL) 1109 goto bad; 1110 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1111 m_tag_prepend(m, mtag); 1112 } 1113 1114 ip6_output(m, NULL, &ro, 0, &im6o, NULL, NULL); 1115 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1116 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1117 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1118 1119 /* We don't cache this route. */ 1120 RO_RTFREE(&ro); 1121 1122 return; 1123 1124 bad: 1125 if (ro.ro_rt) { 1126 RTFREE(ro.ro_rt); 1127 } 1128 m_freem(m); 1129 return; 1130 } 1131 1132 #ifndef BURN_BRIDGES 1133 void 1134 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1135 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1136 struct sockaddr *sdl0) 1137 { 1138 1139 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1140 RT_DEFAULT_FIB); 1141 } 1142 #endif 1143 1144 caddr_t 1145 nd6_ifptomac(struct ifnet *ifp) 1146 { 1147 switch (ifp->if_type) { 1148 case IFT_ARCNET: 1149 case IFT_ETHER: 1150 case IFT_FDDI: 1151 case IFT_IEEE1394: 1152 #ifdef IFT_L2VLAN 1153 case IFT_L2VLAN: 1154 #endif 1155 #ifdef IFT_IEEE80211 1156 case IFT_IEEE80211: 1157 #endif 1158 case IFT_INFINIBAND: 1159 case IFT_BRIDGE: 1160 case IFT_ISO88025: 1161 return IF_LLADDR(ifp); 1162 default: 1163 return NULL; 1164 } 1165 } 1166 1167 struct dadq { 1168 TAILQ_ENTRY(dadq) dad_list; 1169 struct ifaddr *dad_ifa; 1170 int dad_count; /* max NS to send */ 1171 int dad_ns_tcount; /* # of trials to send NS */ 1172 int dad_ns_ocount; /* NS sent so far */ 1173 int dad_ns_icount; 1174 int dad_na_icount; 1175 int dad_ns_lcount; /* looped back NS */ 1176 int dad_loopbackprobe; /* probing state for loopback detection */ 1177 struct callout dad_timer_ch; 1178 struct vnet *dad_vnet; 1179 u_int dad_refcnt; 1180 #define ND_OPT_NONCE_LEN32 \ 1181 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1182 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1183 }; 1184 1185 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq); 1186 static VNET_DEFINE(struct rwlock, dad_rwlock); 1187 #define V_dadq VNET(dadq) 1188 #define V_dad_rwlock VNET(dad_rwlock) 1189 1190 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1191 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1192 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1193 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1194 1195 static void 1196 nd6_dad_add(struct dadq *dp) 1197 { 1198 1199 DADQ_WLOCK(); 1200 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1201 DADQ_WUNLOCK(); 1202 } 1203 1204 static void 1205 nd6_dad_del(struct dadq *dp) 1206 { 1207 1208 DADQ_WLOCK(); 1209 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1210 DADQ_WUNLOCK(); 1211 nd6_dad_rele(dp); 1212 } 1213 1214 static struct dadq * 1215 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1216 { 1217 struct dadq *dp; 1218 1219 DADQ_RLOCK(); 1220 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1221 if (dp->dad_ifa != ifa) 1222 continue; 1223 /* 1224 * Skip if the nonce matches the received one. 1225 * +2 in the length is required because of type and 1226 * length fields are included in a header. 1227 */ 1228 if (n != NULL && 1229 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1230 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1231 ND_OPT_NONCE_LEN) == 0) { 1232 dp->dad_ns_lcount++; 1233 continue; 1234 } 1235 refcount_acquire(&dp->dad_refcnt); 1236 break; 1237 } 1238 DADQ_RUNLOCK(); 1239 1240 return (dp); 1241 } 1242 1243 static void 1244 nd6_dad_starttimer(struct dadq *dp, int ticks) 1245 { 1246 1247 callout_reset(&dp->dad_timer_ch, ticks, 1248 (void (*)(void *))nd6_dad_timer, (void *)dp); 1249 } 1250 1251 static void 1252 nd6_dad_stoptimer(struct dadq *dp) 1253 { 1254 1255 callout_drain(&dp->dad_timer_ch); 1256 } 1257 1258 static void 1259 nd6_dad_rele(struct dadq *dp) 1260 { 1261 1262 if (refcount_release(&dp->dad_refcnt)) { 1263 ifa_free(dp->dad_ifa); 1264 free(dp, M_IP6NDP); 1265 } 1266 } 1267 1268 void 1269 nd6_dad_init(void) 1270 { 1271 1272 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1273 TAILQ_INIT(&V_dadq); 1274 } 1275 1276 /* 1277 * Start Duplicate Address Detection (DAD) for specified interface address. 1278 */ 1279 void 1280 nd6_dad_start(struct ifaddr *ifa, int delay) 1281 { 1282 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1283 struct dadq *dp; 1284 char ip6buf[INET6_ADDRSTRLEN]; 1285 1286 /* 1287 * If we don't need DAD, don't do it. 1288 * There are several cases: 1289 * - DAD is disabled (ip6_dad_count == 0) 1290 * - the interface address is anycast 1291 */ 1292 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1293 log(LOG_DEBUG, 1294 "nd6_dad_start: called with non-tentative address " 1295 "%s(%s)\n", 1296 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1297 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1298 return; 1299 } 1300 if (ia->ia6_flags & IN6_IFF_ANYCAST) { 1301 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1302 return; 1303 } 1304 if (!V_ip6_dad_count) { 1305 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1306 return; 1307 } 1308 if (ifa->ifa_ifp == NULL) 1309 panic("nd6_dad_start: ifa->ifa_ifp == NULL"); 1310 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) { 1311 return; 1312 } 1313 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) 1314 return; 1315 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1316 /* DAD already in progress */ 1317 nd6_dad_rele(dp); 1318 return; 1319 } 1320 1321 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1322 if (dp == NULL) { 1323 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1324 "%s(%s)\n", 1325 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1326 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1327 return; 1328 } 1329 callout_init(&dp->dad_timer_ch, 0); 1330 #ifdef VIMAGE 1331 dp->dad_vnet = curvnet; 1332 #endif 1333 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1334 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1335 1336 /* 1337 * Send NS packet for DAD, ip6_dad_count times. 1338 * Note that we must delay the first transmission, if this is the 1339 * first packet to be sent from the interface after interface 1340 * (re)initialization. 1341 */ 1342 dp->dad_ifa = ifa; 1343 ifa_ref(dp->dad_ifa); 1344 dp->dad_count = V_ip6_dad_count; 1345 dp->dad_ns_icount = dp->dad_na_icount = 0; 1346 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1347 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1348 refcount_init(&dp->dad_refcnt, 1); 1349 nd6_dad_add(dp); 1350 if (delay == 0) { 1351 nd6_dad_ns_output(dp, ifa); 1352 nd6_dad_starttimer(dp, 1353 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1354 } else { 1355 nd6_dad_starttimer(dp, delay); 1356 } 1357 } 1358 1359 /* 1360 * terminate DAD unconditionally. used for address removals. 1361 */ 1362 void 1363 nd6_dad_stop(struct ifaddr *ifa) 1364 { 1365 struct dadq *dp; 1366 1367 dp = nd6_dad_find(ifa, NULL); 1368 if (!dp) { 1369 /* DAD wasn't started yet */ 1370 return; 1371 } 1372 1373 nd6_dad_stoptimer(dp); 1374 1375 /* 1376 * The DAD queue entry may have been removed by nd6_dad_timer() while 1377 * we were waiting for it to stop, so re-do the lookup. 1378 */ 1379 nd6_dad_rele(dp); 1380 if (nd6_dad_find(ifa, NULL) == NULL) 1381 return; 1382 1383 nd6_dad_del(dp); 1384 nd6_dad_rele(dp); 1385 } 1386 1387 static void 1388 nd6_dad_timer(struct dadq *dp) 1389 { 1390 CURVNET_SET(dp->dad_vnet); 1391 struct ifaddr *ifa = dp->dad_ifa; 1392 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1393 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1394 char ip6buf[INET6_ADDRSTRLEN]; 1395 1396 /* Sanity check */ 1397 if (ia == NULL) { 1398 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n"); 1399 goto err; 1400 } 1401 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1402 /* Do not need DAD for ifdisabled interface. */ 1403 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1404 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1405 goto err; 1406 } 1407 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1408 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1409 "%s(%s)\n", 1410 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1411 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1412 goto err; 1413 } 1414 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1415 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1416 "%s(%s)\n", 1417 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1418 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1419 goto err; 1420 } 1421 1422 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1423 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1424 (((ifp->if_flags & IFF_UP) == 0) || 1425 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1426 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n", 1427 if_name(ifa->ifa_ifp))); 1428 goto err; 1429 } 1430 1431 /* Need more checks? */ 1432 if (dp->dad_ns_ocount < dp->dad_count) { 1433 /* 1434 * We have more NS to go. Send NS packet for DAD. 1435 */ 1436 nd6_dad_ns_output(dp, ifa); 1437 nd6_dad_starttimer(dp, 1438 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1439 goto done; 1440 } else { 1441 /* 1442 * We have transmitted sufficient number of DAD packets. 1443 * See what we've got. 1444 */ 1445 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1446 /* We've seen NS or NA, means DAD has failed. */ 1447 nd6_dad_duplicated(ifa, dp); 1448 else if (V_dad_enhanced != 0 && 1449 dp->dad_ns_lcount > 0 && 1450 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1451 /* 1452 * A looped back probe is detected, 1453 * Sec. 4.1 in draft-ietf-6man-enhanced-dad-13 1454 * requires transmission of additional probes until 1455 * the loopback condition becomes clear. 1456 */ 1457 log(LOG_ERR, "%s: a looped back NS message is " 1458 "detected during DAD for %s. " 1459 "Another DAD probes are being sent.\n", 1460 if_name(ifa->ifa_ifp), 1461 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1462 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1463 /* 1464 * An interface with IGNORELOOP is one which a 1465 * loopback is permanently expected while regular 1466 * traffic works. In that case, stop DAD after 1467 * MAX_MULTICAST_SOLICIT number of NS messages 1468 * regardless of the number of received loopback NS 1469 * by increasing dad_loopbackprobe in advance. 1470 */ 1471 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IGNORELOOP) 1472 dp->dad_loopbackprobe += V_nd6_mmaxtries; 1473 /* 1474 * Send an NS immediately and increase dad_count by 1475 * V_nd6_mmaxtries - 1. 1476 */ 1477 nd6_dad_ns_output(dp, ifa); 1478 dp->dad_count = 1479 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1480 nd6_dad_starttimer(dp, 1481 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1482 goto done; 1483 } else { 1484 /* 1485 * We are done with DAD. No NA came, no NS came. 1486 * No duplicate address found. Check IFDISABLED flag 1487 * again in case that it is changed between the 1488 * beginning of this function and here. 1489 */ 1490 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1491 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1492 1493 nd6log((LOG_DEBUG, 1494 "%s: DAD complete for %s - no duplicates found\n", 1495 if_name(ifa->ifa_ifp), 1496 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1497 if (dp->dad_ns_lcount > 0) 1498 log(LOG_ERR, "%s: DAD completed while " 1499 "a looped back NS message is detected " 1500 "during DAD for %s.\n", 1501 if_name(ifa->ifa_ifp), 1502 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1503 } 1504 } 1505 err: 1506 nd6_dad_del(dp); 1507 done: 1508 CURVNET_RESTORE(); 1509 } 1510 1511 static void 1512 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1513 { 1514 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1515 struct ifnet *ifp; 1516 char ip6buf[INET6_ADDRSTRLEN]; 1517 1518 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1519 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1520 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1521 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1522 dp->dad_na_icount); 1523 1524 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1525 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1526 1527 ifp = ifa->ifa_ifp; 1528 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1529 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1530 log(LOG_ERR, "%s: manual intervention required\n", 1531 if_name(ifp)); 1532 1533 /* 1534 * If the address is a link-local address formed from an interface 1535 * identifier based on the hardware address which is supposed to be 1536 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1537 * operation on the interface SHOULD be disabled. 1538 * [RFC 4862, Section 5.4.5] 1539 */ 1540 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1541 struct in6_addr in6; 1542 1543 /* 1544 * To avoid over-reaction, we only apply this logic when we are 1545 * very sure that hardware addresses are supposed to be unique. 1546 */ 1547 switch (ifp->if_type) { 1548 case IFT_ETHER: 1549 case IFT_FDDI: 1550 case IFT_ATM: 1551 case IFT_IEEE1394: 1552 #ifdef IFT_IEEE80211 1553 case IFT_IEEE80211: 1554 #endif 1555 case IFT_INFINIBAND: 1556 in6 = ia->ia_addr.sin6_addr; 1557 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1558 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1559 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1560 log(LOG_ERR, "%s: possible hardware address " 1561 "duplication detected, disable IPv6\n", 1562 if_name(ifp)); 1563 } 1564 break; 1565 } 1566 } 1567 } 1568 1569 static void 1570 nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa) 1571 { 1572 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1573 struct ifnet *ifp = ifa->ifa_ifp; 1574 int i; 1575 1576 dp->dad_ns_tcount++; 1577 if ((ifp->if_flags & IFF_UP) == 0) { 1578 return; 1579 } 1580 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1581 return; 1582 } 1583 1584 dp->dad_ns_ocount++; 1585 if (V_dad_enhanced != 0) { 1586 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1587 dp->dad_nonce[i] = arc4random(); 1588 /* 1589 * XXXHRS: Note that in the case that 1590 * DupAddrDetectTransmits > 1, multiple NS messages with 1591 * different nonces can be looped back in an unexpected 1592 * order. The current implementation recognizes only 1593 * the latest nonce on the sender side. Practically it 1594 * should work well in almost all cases. 1595 */ 1596 } 1597 nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1598 (uint8_t *)&dp->dad_nonce[0]); 1599 } 1600 1601 static void 1602 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1603 { 1604 struct in6_ifaddr *ia; 1605 struct ifnet *ifp; 1606 const struct in6_addr *taddr6; 1607 struct dadq *dp; 1608 1609 if (ifa == NULL) 1610 panic("ifa == NULL in nd6_dad_ns_input"); 1611 1612 ia = (struct in6_ifaddr *)ifa; 1613 ifp = ifa->ifa_ifp; 1614 taddr6 = &ia->ia_addr.sin6_addr; 1615 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1616 if (V_dad_enhanced == 0) 1617 ndopt_nonce = NULL; 1618 dp = nd6_dad_find(ifa, ndopt_nonce); 1619 if (dp == NULL) 1620 return; 1621 1622 dp->dad_ns_icount++; 1623 nd6_dad_rele(dp); 1624 } 1625 1626 static void 1627 nd6_dad_na_input(struct ifaddr *ifa) 1628 { 1629 struct dadq *dp; 1630 1631 if (ifa == NULL) 1632 panic("ifa == NULL in nd6_dad_na_input"); 1633 1634 dp = nd6_dad_find(ifa, NULL); 1635 if (dp != NULL) { 1636 dp->dad_na_icount++; 1637 nd6_dad_rele(dp); 1638 } 1639 } 1640