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 if (max_linkhdr + maxlen >= MCLBYTES) { 421 #ifdef DIAGNOSTIC 422 printf("%s: max_linkhdr + maxlen >= MCLBYTES " 423 "(%d + %d > %d)\n", __func__, max_linkhdr, maxlen, 424 MCLBYTES); 425 #endif 426 return; 427 } 428 429 if (max_linkhdr + maxlen > MHLEN) 430 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 431 else 432 m = m_gethdr(M_NOWAIT, MT_DATA); 433 if (m == NULL) 434 return; 435 M_SETFIB(m, fibnum); 436 437 bzero(&ro, sizeof(ro)); 438 439 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 440 m->m_flags |= M_MCAST; 441 im6o.im6o_multicast_ifp = ifp; 442 im6o.im6o_multicast_hlim = 255; 443 im6o.im6o_multicast_loop = 0; 444 } 445 446 icmp6len = sizeof(*nd_ns); 447 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 448 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 449 450 /* fill neighbor solicitation packet */ 451 ip6 = mtod(m, struct ip6_hdr *); 452 ip6->ip6_flow = 0; 453 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 454 ip6->ip6_vfc |= IPV6_VERSION; 455 /* ip6->ip6_plen will be set later */ 456 ip6->ip6_nxt = IPPROTO_ICMPV6; 457 ip6->ip6_hlim = 255; 458 if (daddr6) 459 ip6->ip6_dst = *daddr6; 460 else { 461 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 462 ip6->ip6_dst.s6_addr16[1] = 0; 463 ip6->ip6_dst.s6_addr32[1] = 0; 464 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 465 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 466 ip6->ip6_dst.s6_addr8[12] = 0xff; 467 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 468 goto bad; 469 } 470 if (nonce == NULL) { 471 struct ifaddr *ifa; 472 473 /* 474 * RFC2461 7.2.2: 475 * "If the source address of the packet prompting the 476 * solicitation is the same as one of the addresses assigned 477 * to the outgoing interface, that address SHOULD be placed 478 * in the IP Source Address of the outgoing solicitation. 479 * Otherwise, any one of the addresses assigned to the 480 * interface should be used." 481 * 482 * We use the source address for the prompting packet 483 * (saddr6), if: 484 * - saddr6 is given from the caller (by giving "ln"), and 485 * - saddr6 belongs to the outgoing interface. 486 * Otherwise, we perform the source address selection as usual. 487 */ 488 struct in6_addr *hsrc; 489 490 hsrc = NULL; 491 if (ln != NULL) { 492 LLE_RLOCK(ln); 493 if (ln->la_hold != NULL) { 494 struct ip6_hdr *hip6; /* hold ip6 */ 495 496 /* 497 * assuming every packet in la_hold has the same IP 498 * header 499 */ 500 hip6 = mtod(ln->la_hold, struct ip6_hdr *); 501 /* XXX pullup? */ 502 if (sizeof(*hip6) < ln->la_hold->m_len) { 503 ip6->ip6_src = hip6->ip6_src; 504 hsrc = &hip6->ip6_src; 505 } 506 } 507 LLE_RUNLOCK(ln); 508 } 509 if (hsrc && (ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, 510 hsrc)) != NULL) { 511 /* ip6_src set already. */ 512 ifa_free(ifa); 513 } else { 514 int error; 515 struct sockaddr_in6 dst_sa; 516 struct in6_addr src_in; 517 struct ifnet *oifp; 518 519 bzero(&dst_sa, sizeof(dst_sa)); 520 dst_sa.sin6_family = AF_INET6; 521 dst_sa.sin6_len = sizeof(dst_sa); 522 dst_sa.sin6_addr = ip6->ip6_dst; 523 524 oifp = ifp; 525 error = in6_selectsrc(&dst_sa, NULL, 526 NULL, &ro, NULL, &oifp, &src_in); 527 if (error) { 528 char ip6buf[INET6_ADDRSTRLEN]; 529 nd6log((LOG_DEBUG, "%s: source can't be " 530 "determined: dst=%s, error=%d\n", __func__, 531 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), 532 error)); 533 goto bad; 534 } 535 ip6->ip6_src = src_in; 536 } 537 } else { 538 /* 539 * Source address for DAD packet must always be IPv6 540 * unspecified address. (0::0) 541 * We actually don't have to 0-clear the address (we did it 542 * above), but we do so here explicitly to make the intention 543 * clearer. 544 */ 545 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 546 } 547 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 548 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 549 nd_ns->nd_ns_code = 0; 550 nd_ns->nd_ns_reserved = 0; 551 nd_ns->nd_ns_target = *taddr6; 552 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 553 554 /* 555 * Add source link-layer address option. 556 * 557 * spec implementation 558 * --- --- 559 * DAD packet MUST NOT do not add the option 560 * there's no link layer address: 561 * impossible do not add the option 562 * there's link layer address: 563 * Multicast NS MUST add one add the option 564 * Unicast NS SHOULD add one add the option 565 */ 566 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 567 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 568 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 569 /* 8 byte alignments... */ 570 optlen = (optlen + 7) & ~7; 571 572 m->m_pkthdr.len += optlen; 573 m->m_len += optlen; 574 icmp6len += optlen; 575 bzero((caddr_t)nd_opt, optlen); 576 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 577 nd_opt->nd_opt_len = optlen >> 3; 578 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 579 } 580 /* 581 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 582 * This behavior is documented as Enhanced Duplicate Address 583 * Detection in draft-ietf-6man-enhanced-dad-13. 584 * net.inet6.ip6.dad_enhanced=0 disables this. 585 */ 586 if (V_dad_enhanced != 0 && nonce != NULL) { 587 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 588 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 589 /* 8-byte alignment is required. */ 590 optlen = (optlen + 7) & ~7; 591 592 m->m_pkthdr.len += optlen; 593 m->m_len += optlen; 594 icmp6len += optlen; 595 bzero((caddr_t)nd_opt, optlen); 596 nd_opt->nd_opt_type = ND_OPT_NONCE; 597 nd_opt->nd_opt_len = optlen >> 3; 598 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 599 } 600 ip6->ip6_plen = htons((u_short)icmp6len); 601 nd_ns->nd_ns_cksum = 0; 602 nd_ns->nd_ns_cksum = 603 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 604 605 if (send_sendso_input_hook != NULL) { 606 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 607 sizeof(unsigned short), M_NOWAIT); 608 if (mtag == NULL) 609 goto bad; 610 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 611 m_tag_prepend(m, mtag); 612 } 613 614 ip6_output(m, NULL, &ro, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 615 &im6o, NULL, NULL); 616 icmp6_ifstat_inc(ifp, ifs6_out_msg); 617 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 618 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 619 620 /* We don't cache this route. */ 621 RO_RTFREE(&ro); 622 623 return; 624 625 bad: 626 if (ro.ro_rt) { 627 RTFREE(ro.ro_rt); 628 } 629 m_freem(m); 630 return; 631 } 632 633 #ifndef BURN_BRIDGES 634 void 635 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6, 636 const struct in6_addr *taddr6, struct llentry *ln, uint8_t *nonce) 637 { 638 639 nd6_ns_output_fib(ifp, daddr6, taddr6, ln, nonce, RT_DEFAULT_FIB); 640 } 641 #endif 642 /* 643 * Neighbor advertisement input handling. 644 * 645 * Based on RFC 2461 646 * Based on RFC 2462 (duplicate address detection) 647 * 648 * the following items are not implemented yet: 649 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 650 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 651 */ 652 void 653 nd6_na_input(struct mbuf *m, int off, int icmp6len) 654 { 655 struct ifnet *ifp = m->m_pkthdr.rcvif; 656 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 657 struct nd_neighbor_advert *nd_na; 658 struct in6_addr daddr6 = ip6->ip6_dst; 659 struct in6_addr taddr6; 660 int flags; 661 int is_router; 662 int is_solicited; 663 int is_override; 664 char *lladdr = NULL; 665 int lladdrlen = 0; 666 int checklink = 0; 667 struct ifaddr *ifa; 668 struct llentry *ln = NULL; 669 union nd_opts ndopts; 670 struct mbuf *chain = NULL; 671 struct sockaddr_in6 sin6; 672 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 673 674 if (ip6->ip6_hlim != 255) { 675 nd6log((LOG_ERR, 676 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 677 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 678 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 679 goto bad; 680 } 681 682 #ifndef PULLDOWN_TEST 683 IP6_EXTHDR_CHECK(m, off, icmp6len,); 684 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 685 #else 686 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 687 if (nd_na == NULL) { 688 ICMP6STAT_INC(icp6s_tooshort); 689 return; 690 } 691 #endif 692 693 flags = nd_na->nd_na_flags_reserved; 694 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 695 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 696 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 697 memset(&sin6, 0, sizeof(sin6)); 698 699 taddr6 = nd_na->nd_na_target; 700 if (in6_setscope(&taddr6, ifp, NULL)) 701 goto bad; /* XXX: impossible */ 702 703 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 704 nd6log((LOG_ERR, 705 "nd6_na_input: invalid target address %s\n", 706 ip6_sprintf(ip6bufs, &taddr6))); 707 goto bad; 708 } 709 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 710 if (is_solicited) { 711 nd6log((LOG_ERR, 712 "nd6_na_input: a solicited adv is multicasted\n")); 713 goto bad; 714 } 715 716 icmp6len -= sizeof(*nd_na); 717 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 718 if (nd6_options(&ndopts) < 0) { 719 nd6log((LOG_INFO, 720 "nd6_na_input: invalid ND option, ignored\n")); 721 /* nd6_options have incremented stats */ 722 goto freeit; 723 } 724 725 if (ndopts.nd_opts_tgt_lladdr) { 726 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 727 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 728 } 729 730 /* 731 * This effectively disables the DAD check on a non-master CARP 732 * address. 733 */ 734 if (ifp->if_carp) 735 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 736 else 737 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 738 739 /* 740 * Target address matches one of my interface address. 741 * 742 * If my address is tentative, this means that there's somebody 743 * already using the same address as mine. This indicates DAD failure. 744 * This is defined in RFC 2462. 745 * 746 * Otherwise, process as defined in RFC 2461. 747 */ 748 if (ifa 749 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 750 ifa_free(ifa); 751 nd6_dad_na_input(ifa); 752 goto freeit; 753 } 754 755 /* Just for safety, maybe unnecessary. */ 756 if (ifa) { 757 ifa_free(ifa); 758 log(LOG_ERR, 759 "nd6_na_input: duplicate IP6 address %s\n", 760 ip6_sprintf(ip6bufs, &taddr6)); 761 goto freeit; 762 } 763 764 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 765 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 766 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 767 ifp->if_addrlen, lladdrlen - 2)); 768 goto bad; 769 } 770 771 /* 772 * If no neighbor cache entry is found, NA SHOULD silently be 773 * discarded. 774 */ 775 IF_AFDATA_RLOCK(ifp); 776 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 777 IF_AFDATA_RUNLOCK(ifp); 778 if (ln == NULL) { 779 goto freeit; 780 } 781 782 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 783 /* 784 * If the link-layer has address, and no lladdr option came, 785 * discard the packet. 786 */ 787 if (ifp->if_addrlen && lladdr == NULL) { 788 goto freeit; 789 } 790 791 /* 792 * Record link-layer address, and update the state. 793 */ 794 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen); 795 ln->la_flags |= LLE_VALID; 796 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 797 if (is_solicited) { 798 ln->ln_state = ND6_LLINFO_REACHABLE; 799 ln->ln_byhint = 0; 800 if (!ND6_LLINFO_PERMANENT(ln)) { 801 nd6_llinfo_settimer_locked(ln, 802 (long)ND_IFINFO(ln->lle_tbl->llt_ifp)->reachable * hz); 803 } 804 } else { 805 ln->ln_state = ND6_LLINFO_STALE; 806 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz); 807 } 808 if ((ln->ln_router = is_router) != 0) { 809 /* 810 * This means a router's state has changed from 811 * non-reachable to probably reachable, and might 812 * affect the status of associated prefixes.. 813 */ 814 checklink = 1; 815 } 816 } else { 817 int llchange; 818 819 /* 820 * Check if the link-layer address has changed or not. 821 */ 822 if (lladdr == NULL) 823 llchange = 0; 824 else { 825 if (ln->la_flags & LLE_VALID) { 826 if (bcmp(lladdr, &ln->ll_addr, ifp->if_addrlen)) 827 llchange = 1; 828 else 829 llchange = 0; 830 } else 831 llchange = 1; 832 } 833 834 /* 835 * This is VERY complex. Look at it with care. 836 * 837 * override solicit lladdr llchange action 838 * (L: record lladdr) 839 * 840 * 0 0 n -- (2c) 841 * 0 0 y n (2b) L 842 * 0 0 y y (1) REACHABLE->STALE 843 * 0 1 n -- (2c) *->REACHABLE 844 * 0 1 y n (2b) L *->REACHABLE 845 * 0 1 y y (1) REACHABLE->STALE 846 * 1 0 n -- (2a) 847 * 1 0 y n (2a) L 848 * 1 0 y y (2a) L *->STALE 849 * 1 1 n -- (2a) *->REACHABLE 850 * 1 1 y n (2a) L *->REACHABLE 851 * 1 1 y y (2a) L *->REACHABLE 852 */ 853 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 854 /* 855 * If state is REACHABLE, make it STALE. 856 * no other updates should be done. 857 */ 858 if (ln->ln_state == ND6_LLINFO_REACHABLE) { 859 ln->ln_state = ND6_LLINFO_STALE; 860 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz); 861 } 862 goto freeit; 863 } else if (is_override /* (2a) */ 864 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 865 || lladdr == NULL) { /* (2c) */ 866 /* 867 * Update link-local address, if any. 868 */ 869 if (lladdr != NULL) { 870 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen); 871 ln->la_flags |= LLE_VALID; 872 EVENTHANDLER_INVOKE(lle_event, ln, 873 LLENTRY_RESOLVED); 874 } 875 876 /* 877 * If solicited, make the state REACHABLE. 878 * If not solicited and the link-layer address was 879 * changed, make it STALE. 880 */ 881 if (is_solicited) { 882 ln->ln_state = ND6_LLINFO_REACHABLE; 883 ln->ln_byhint = 0; 884 if (!ND6_LLINFO_PERMANENT(ln)) { 885 nd6_llinfo_settimer_locked(ln, 886 (long)ND_IFINFO(ifp)->reachable * hz); 887 } 888 } else { 889 if (lladdr != NULL && llchange) { 890 ln->ln_state = ND6_LLINFO_STALE; 891 nd6_llinfo_settimer_locked(ln, 892 (long)V_nd6_gctimer * hz); 893 } 894 } 895 } 896 897 if (ln->ln_router && !is_router) { 898 /* 899 * The peer dropped the router flag. 900 * Remove the sender from the Default Router List and 901 * update the Destination Cache entries. 902 */ 903 struct nd_defrouter *dr; 904 struct in6_addr *in6; 905 906 in6 = &L3_ADDR_SIN6(ln)->sin6_addr; 907 908 /* 909 * Lock to protect the default router list. 910 * XXX: this might be unnecessary, since this function 911 * is only called under the network software interrupt 912 * context. However, we keep it just for safety. 913 */ 914 dr = defrouter_lookup(in6, ln->lle_tbl->llt_ifp); 915 if (dr) 916 defrtrlist_del(dr); 917 else if (ND_IFINFO(ln->lle_tbl->llt_ifp)->flags & 918 ND6_IFF_ACCEPT_RTADV) { 919 /* 920 * Even if the neighbor is not in the default 921 * router list, the neighbor may be used 922 * as a next hop for some destinations 923 * (e.g. redirect case). So we must 924 * call rt6_flush explicitly. 925 */ 926 rt6_flush(&ip6->ip6_src, ifp); 927 } 928 } 929 ln->ln_router = is_router; 930 } 931 /* XXX - QL 932 * Does this matter? 933 * rt->rt_flags &= ~RTF_REJECT; 934 */ 935 ln->la_asked = 0; 936 if (ln->la_hold != NULL) 937 nd6_grab_holdchain(ln, &chain, &sin6); 938 freeit: 939 if (ln != NULL) 940 LLE_WUNLOCK(ln); 941 942 if (chain != NULL) 943 nd6_flush_holdchain(ifp, ifp, chain, &sin6); 944 945 if (checklink) 946 pfxlist_onlink_check(); 947 948 m_freem(m); 949 return; 950 951 bad: 952 if (ln != NULL) 953 LLE_WUNLOCK(ln); 954 955 ICMP6STAT_INC(icp6s_badna); 956 m_freem(m); 957 } 958 959 /* 960 * Neighbor advertisement output handling. 961 * 962 * Based on RFC 2461 963 * 964 * the following items are not implemented yet: 965 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 966 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 967 * 968 * tlladdr - 1 if include target link-layer address 969 * sdl0 - sockaddr_dl (= proxy NA) or NULL 970 */ 971 static void 972 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 973 const struct in6_addr *taddr6, u_long flags, int tlladdr, 974 struct sockaddr *sdl0, u_int fibnum) 975 { 976 struct mbuf *m; 977 struct m_tag *mtag; 978 struct ifnet *oifp; 979 struct ip6_hdr *ip6; 980 struct nd_neighbor_advert *nd_na; 981 struct ip6_moptions im6o; 982 struct in6_addr src, daddr6; 983 struct sockaddr_in6 dst_sa; 984 int icmp6len, maxlen, error; 985 caddr_t mac = NULL; 986 struct route_in6 ro; 987 988 bzero(&ro, sizeof(ro)); 989 990 daddr6 = *daddr6_0; /* make a local copy for modification */ 991 992 /* estimate the size of message */ 993 maxlen = sizeof(*ip6) + sizeof(*nd_na); 994 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 995 if (max_linkhdr + maxlen >= MCLBYTES) { 996 #ifdef DIAGNOSTIC 997 printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES " 998 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES); 999 #endif 1000 return; 1001 } 1002 1003 if (max_linkhdr + maxlen > MHLEN) 1004 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 1005 else 1006 m = m_gethdr(M_NOWAIT, MT_DATA); 1007 if (m == NULL) 1008 return; 1009 M_SETFIB(m, fibnum); 1010 1011 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 1012 m->m_flags |= M_MCAST; 1013 im6o.im6o_multicast_ifp = ifp; 1014 im6o.im6o_multicast_hlim = 255; 1015 im6o.im6o_multicast_loop = 0; 1016 } 1017 1018 icmp6len = sizeof(*nd_na); 1019 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 1020 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */ 1021 1022 /* fill neighbor advertisement packet */ 1023 ip6 = mtod(m, struct ip6_hdr *); 1024 ip6->ip6_flow = 0; 1025 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 1026 ip6->ip6_vfc |= IPV6_VERSION; 1027 ip6->ip6_nxt = IPPROTO_ICMPV6; 1028 ip6->ip6_hlim = 255; 1029 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 1030 /* reply to DAD */ 1031 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 1032 daddr6.s6_addr16[1] = 0; 1033 daddr6.s6_addr32[1] = 0; 1034 daddr6.s6_addr32[2] = 0; 1035 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 1036 if (in6_setscope(&daddr6, ifp, NULL)) 1037 goto bad; 1038 1039 flags &= ~ND_NA_FLAG_SOLICITED; 1040 } 1041 ip6->ip6_dst = daddr6; 1042 bzero(&dst_sa, sizeof(struct sockaddr_in6)); 1043 dst_sa.sin6_family = AF_INET6; 1044 dst_sa.sin6_len = sizeof(struct sockaddr_in6); 1045 dst_sa.sin6_addr = daddr6; 1046 1047 /* 1048 * Select a source whose scope is the same as that of the dest. 1049 */ 1050 bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa)); 1051 oifp = ifp; 1052 error = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, &oifp, &src); 1053 if (error) { 1054 char ip6buf[INET6_ADDRSTRLEN]; 1055 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1056 "determined: dst=%s, error=%d\n", 1057 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), error)); 1058 goto bad; 1059 } 1060 ip6->ip6_src = src; 1061 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1062 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1063 nd_na->nd_na_code = 0; 1064 nd_na->nd_na_target = *taddr6; 1065 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1066 1067 /* 1068 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1069 * see nd6_ns_input() for details. 1070 * Basically, if NS packet is sent to unicast/anycast addr, 1071 * target lladdr option SHOULD NOT be included. 1072 */ 1073 if (tlladdr) { 1074 /* 1075 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1076 * lladdr in sdl0. If we are not proxying (sending NA for 1077 * my address) use lladdr configured for the interface. 1078 */ 1079 if (sdl0 == NULL) { 1080 if (ifp->if_carp) 1081 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1082 if (mac == NULL) 1083 mac = nd6_ifptomac(ifp); 1084 } else if (sdl0->sa_family == AF_LINK) { 1085 struct sockaddr_dl *sdl; 1086 sdl = (struct sockaddr_dl *)sdl0; 1087 if (sdl->sdl_alen == ifp->if_addrlen) 1088 mac = LLADDR(sdl); 1089 } 1090 } 1091 if (tlladdr && mac) { 1092 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1093 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1094 1095 /* roundup to 8 bytes alignment! */ 1096 optlen = (optlen + 7) & ~7; 1097 1098 m->m_pkthdr.len += optlen; 1099 m->m_len += optlen; 1100 icmp6len += optlen; 1101 bzero((caddr_t)nd_opt, optlen); 1102 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1103 nd_opt->nd_opt_len = optlen >> 3; 1104 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1105 } else 1106 flags &= ~ND_NA_FLAG_OVERRIDE; 1107 1108 ip6->ip6_plen = htons((u_short)icmp6len); 1109 nd_na->nd_na_flags_reserved = flags; 1110 nd_na->nd_na_cksum = 0; 1111 nd_na->nd_na_cksum = 1112 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1113 1114 if (send_sendso_input_hook != NULL) { 1115 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1116 sizeof(unsigned short), M_NOWAIT); 1117 if (mtag == NULL) 1118 goto bad; 1119 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1120 m_tag_prepend(m, mtag); 1121 } 1122 1123 ip6_output(m, NULL, &ro, 0, &im6o, NULL, NULL); 1124 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1125 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1126 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1127 1128 /* We don't cache this route. */ 1129 RO_RTFREE(&ro); 1130 1131 return; 1132 1133 bad: 1134 if (ro.ro_rt) { 1135 RTFREE(ro.ro_rt); 1136 } 1137 m_freem(m); 1138 return; 1139 } 1140 1141 #ifndef BURN_BRIDGES 1142 void 1143 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1144 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1145 struct sockaddr *sdl0) 1146 { 1147 1148 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1149 RT_DEFAULT_FIB); 1150 } 1151 #endif 1152 1153 caddr_t 1154 nd6_ifptomac(struct ifnet *ifp) 1155 { 1156 switch (ifp->if_type) { 1157 case IFT_ARCNET: 1158 case IFT_ETHER: 1159 case IFT_FDDI: 1160 case IFT_IEEE1394: 1161 #ifdef IFT_L2VLAN 1162 case IFT_L2VLAN: 1163 #endif 1164 #ifdef IFT_IEEE80211 1165 case IFT_IEEE80211: 1166 #endif 1167 case IFT_INFINIBAND: 1168 case IFT_BRIDGE: 1169 case IFT_ISO88025: 1170 return IF_LLADDR(ifp); 1171 default: 1172 return NULL; 1173 } 1174 } 1175 1176 struct dadq { 1177 TAILQ_ENTRY(dadq) dad_list; 1178 struct ifaddr *dad_ifa; 1179 int dad_count; /* max NS to send */ 1180 int dad_ns_tcount; /* # of trials to send NS */ 1181 int dad_ns_ocount; /* NS sent so far */ 1182 int dad_ns_icount; 1183 int dad_na_icount; 1184 int dad_ns_lcount; /* looped back NS */ 1185 int dad_loopbackprobe; /* probing state for loopback detection */ 1186 struct callout dad_timer_ch; 1187 struct vnet *dad_vnet; 1188 u_int dad_refcnt; 1189 #define ND_OPT_NONCE_LEN32 \ 1190 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1191 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1192 }; 1193 1194 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq); 1195 static VNET_DEFINE(struct rwlock, dad_rwlock); 1196 #define V_dadq VNET(dadq) 1197 #define V_dad_rwlock VNET(dad_rwlock) 1198 1199 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1200 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1201 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1202 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1203 1204 static void 1205 nd6_dad_add(struct dadq *dp) 1206 { 1207 1208 DADQ_WLOCK(); 1209 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1210 DADQ_WUNLOCK(); 1211 } 1212 1213 static void 1214 nd6_dad_del(struct dadq *dp) 1215 { 1216 1217 DADQ_WLOCK(); 1218 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1219 DADQ_WUNLOCK(); 1220 nd6_dad_rele(dp); 1221 } 1222 1223 static struct dadq * 1224 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1225 { 1226 struct dadq *dp; 1227 1228 DADQ_RLOCK(); 1229 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1230 if (dp->dad_ifa != ifa) 1231 continue; 1232 /* 1233 * Skip if the nonce matches the received one. 1234 * +2 in the length is required because of type and 1235 * length fields are included in a header. 1236 */ 1237 if (n != NULL && 1238 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1239 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1240 ND_OPT_NONCE_LEN) == 0) { 1241 dp->dad_ns_lcount++; 1242 continue; 1243 } 1244 refcount_acquire(&dp->dad_refcnt); 1245 break; 1246 } 1247 DADQ_RUNLOCK(); 1248 1249 return (dp); 1250 } 1251 1252 static void 1253 nd6_dad_starttimer(struct dadq *dp, int ticks) 1254 { 1255 1256 callout_reset(&dp->dad_timer_ch, ticks, 1257 (void (*)(void *))nd6_dad_timer, (void *)dp); 1258 } 1259 1260 static void 1261 nd6_dad_stoptimer(struct dadq *dp) 1262 { 1263 1264 callout_drain(&dp->dad_timer_ch); 1265 } 1266 1267 static void 1268 nd6_dad_rele(struct dadq *dp) 1269 { 1270 1271 if (refcount_release(&dp->dad_refcnt)) { 1272 ifa_free(dp->dad_ifa); 1273 free(dp, M_IP6NDP); 1274 } 1275 } 1276 1277 void 1278 nd6_dad_init(void) 1279 { 1280 1281 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1282 TAILQ_INIT(&V_dadq); 1283 } 1284 1285 /* 1286 * Start Duplicate Address Detection (DAD) for specified interface address. 1287 */ 1288 void 1289 nd6_dad_start(struct ifaddr *ifa, int delay) 1290 { 1291 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1292 struct dadq *dp; 1293 char ip6buf[INET6_ADDRSTRLEN]; 1294 1295 /* 1296 * If we don't need DAD, don't do it. 1297 * There are several cases: 1298 * - DAD is disabled (ip6_dad_count == 0) 1299 * - the interface address is anycast 1300 */ 1301 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1302 log(LOG_DEBUG, 1303 "nd6_dad_start: called with non-tentative address " 1304 "%s(%s)\n", 1305 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1306 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1307 return; 1308 } 1309 if (ia->ia6_flags & IN6_IFF_ANYCAST) { 1310 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1311 return; 1312 } 1313 if (!V_ip6_dad_count) { 1314 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1315 return; 1316 } 1317 if (ifa->ifa_ifp == NULL) 1318 panic("nd6_dad_start: ifa->ifa_ifp == NULL"); 1319 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) { 1320 return; 1321 } 1322 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) 1323 return; 1324 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1325 /* DAD already in progress */ 1326 nd6_dad_rele(dp); 1327 return; 1328 } 1329 1330 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1331 if (dp == NULL) { 1332 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1333 "%s(%s)\n", 1334 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1335 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1336 return; 1337 } 1338 callout_init(&dp->dad_timer_ch, 0); 1339 #ifdef VIMAGE 1340 dp->dad_vnet = curvnet; 1341 #endif 1342 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1343 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1344 1345 /* 1346 * Send NS packet for DAD, ip6_dad_count times. 1347 * Note that we must delay the first transmission, if this is the 1348 * first packet to be sent from the interface after interface 1349 * (re)initialization. 1350 */ 1351 dp->dad_ifa = ifa; 1352 ifa_ref(dp->dad_ifa); 1353 dp->dad_count = V_ip6_dad_count; 1354 dp->dad_ns_icount = dp->dad_na_icount = 0; 1355 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1356 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1357 refcount_init(&dp->dad_refcnt, 1); 1358 nd6_dad_add(dp); 1359 if (delay == 0) { 1360 nd6_dad_ns_output(dp, ifa); 1361 nd6_dad_starttimer(dp, 1362 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1363 } else { 1364 nd6_dad_starttimer(dp, delay); 1365 } 1366 } 1367 1368 /* 1369 * terminate DAD unconditionally. used for address removals. 1370 */ 1371 void 1372 nd6_dad_stop(struct ifaddr *ifa) 1373 { 1374 struct dadq *dp; 1375 1376 dp = nd6_dad_find(ifa, NULL); 1377 if (!dp) { 1378 /* DAD wasn't started yet */ 1379 return; 1380 } 1381 1382 nd6_dad_stoptimer(dp); 1383 1384 /* 1385 * The DAD queue entry may have been removed by nd6_dad_timer() while 1386 * we were waiting for it to stop, so re-do the lookup. 1387 */ 1388 nd6_dad_rele(dp); 1389 if (nd6_dad_find(ifa, NULL) == NULL) 1390 return; 1391 1392 nd6_dad_del(dp); 1393 nd6_dad_rele(dp); 1394 } 1395 1396 static void 1397 nd6_dad_timer(struct dadq *dp) 1398 { 1399 CURVNET_SET(dp->dad_vnet); 1400 struct ifaddr *ifa = dp->dad_ifa; 1401 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1402 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1403 char ip6buf[INET6_ADDRSTRLEN]; 1404 1405 /* Sanity check */ 1406 if (ia == NULL) { 1407 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n"); 1408 goto err; 1409 } 1410 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1411 /* Do not need DAD for ifdisabled interface. */ 1412 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1413 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1414 goto err; 1415 } 1416 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1417 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1418 "%s(%s)\n", 1419 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1420 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1421 goto err; 1422 } 1423 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1424 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1425 "%s(%s)\n", 1426 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1427 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1428 goto err; 1429 } 1430 1431 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1432 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1433 (((ifp->if_flags & IFF_UP) == 0) || 1434 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1435 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n", 1436 if_name(ifa->ifa_ifp))); 1437 goto err; 1438 } 1439 1440 /* Need more checks? */ 1441 if (dp->dad_ns_ocount < dp->dad_count) { 1442 /* 1443 * We have more NS to go. Send NS packet for DAD. 1444 */ 1445 nd6_dad_ns_output(dp, ifa); 1446 nd6_dad_starttimer(dp, 1447 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1448 goto done; 1449 } else { 1450 /* 1451 * We have transmitted sufficient number of DAD packets. 1452 * See what we've got. 1453 */ 1454 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1455 /* We've seen NS or NA, means DAD has failed. */ 1456 nd6_dad_duplicated(ifa, dp); 1457 else if (V_dad_enhanced != 0 && 1458 dp->dad_ns_lcount > 0 && 1459 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1460 /* 1461 * A looped back probe is detected, 1462 * Sec. 4.1 in draft-ietf-6man-enhanced-dad-13 1463 * requires transmission of additional probes until 1464 * the loopback condition becomes clear. 1465 */ 1466 log(LOG_ERR, "%s: a looped back NS message is " 1467 "detected during DAD for %s. " 1468 "Another DAD probes are being sent.\n", 1469 if_name(ifa->ifa_ifp), 1470 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1471 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1472 /* 1473 * An interface with IGNORELOOP is one which a 1474 * loopback is permanently expected while regular 1475 * traffic works. In that case, stop DAD after 1476 * MAX_MULTICAST_SOLICIT number of NS messages 1477 * regardless of the number of received loopback NS 1478 * by increasing dad_loopbackprobe in advance. 1479 */ 1480 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IGNORELOOP) 1481 dp->dad_loopbackprobe += V_nd6_mmaxtries; 1482 /* 1483 * Send an NS immediately and increase dad_count by 1484 * V_nd6_mmaxtries - 1. 1485 */ 1486 nd6_dad_ns_output(dp, ifa); 1487 dp->dad_count = 1488 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1489 nd6_dad_starttimer(dp, 1490 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1491 goto done; 1492 } else { 1493 /* 1494 * We are done with DAD. No NA came, no NS came. 1495 * No duplicate address found. Check IFDISABLED flag 1496 * again in case that it is changed between the 1497 * beginning of this function and here. 1498 */ 1499 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1500 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1501 1502 nd6log((LOG_DEBUG, 1503 "%s: DAD complete for %s - no duplicates found\n", 1504 if_name(ifa->ifa_ifp), 1505 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1506 if (dp->dad_ns_lcount > 0) 1507 log(LOG_ERR, "%s: DAD completed while " 1508 "a looped back NS message is detected " 1509 "during DAD for %s.\n", 1510 if_name(ifa->ifa_ifp), 1511 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1512 } 1513 } 1514 err: 1515 nd6_dad_del(dp); 1516 done: 1517 CURVNET_RESTORE(); 1518 } 1519 1520 static void 1521 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1522 { 1523 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1524 struct ifnet *ifp; 1525 char ip6buf[INET6_ADDRSTRLEN]; 1526 1527 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1528 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1529 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1530 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1531 dp->dad_na_icount); 1532 1533 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1534 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1535 1536 ifp = ifa->ifa_ifp; 1537 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1538 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1539 log(LOG_ERR, "%s: manual intervention required\n", 1540 if_name(ifp)); 1541 1542 /* 1543 * If the address is a link-local address formed from an interface 1544 * identifier based on the hardware address which is supposed to be 1545 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1546 * operation on the interface SHOULD be disabled. 1547 * [RFC 4862, Section 5.4.5] 1548 */ 1549 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1550 struct in6_addr in6; 1551 1552 /* 1553 * To avoid over-reaction, we only apply this logic when we are 1554 * very sure that hardware addresses are supposed to be unique. 1555 */ 1556 switch (ifp->if_type) { 1557 case IFT_ETHER: 1558 case IFT_FDDI: 1559 case IFT_ATM: 1560 case IFT_IEEE1394: 1561 #ifdef IFT_IEEE80211 1562 case IFT_IEEE80211: 1563 #endif 1564 case IFT_INFINIBAND: 1565 in6 = ia->ia_addr.sin6_addr; 1566 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1567 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1568 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1569 log(LOG_ERR, "%s: possible hardware address " 1570 "duplication detected, disable IPv6\n", 1571 if_name(ifp)); 1572 } 1573 break; 1574 } 1575 } 1576 } 1577 1578 static void 1579 nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa) 1580 { 1581 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1582 struct ifnet *ifp = ifa->ifa_ifp; 1583 int i; 1584 1585 dp->dad_ns_tcount++; 1586 if ((ifp->if_flags & IFF_UP) == 0) { 1587 return; 1588 } 1589 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1590 return; 1591 } 1592 1593 dp->dad_ns_ocount++; 1594 if (V_dad_enhanced != 0) { 1595 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1596 dp->dad_nonce[i] = arc4random(); 1597 /* 1598 * XXXHRS: Note that in the case that 1599 * DupAddrDetectTransmits > 1, multiple NS messages with 1600 * different nonces can be looped back in an unexpected 1601 * order. The current implementation recognizes only 1602 * the latest nonce on the sender side. Practically it 1603 * should work well in almost all cases. 1604 */ 1605 } 1606 nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1607 (uint8_t *)&dp->dad_nonce[0]); 1608 } 1609 1610 static void 1611 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1612 { 1613 struct in6_ifaddr *ia; 1614 struct ifnet *ifp; 1615 const struct in6_addr *taddr6; 1616 struct dadq *dp; 1617 1618 if (ifa == NULL) 1619 panic("ifa == NULL in nd6_dad_ns_input"); 1620 1621 ia = (struct in6_ifaddr *)ifa; 1622 ifp = ifa->ifa_ifp; 1623 taddr6 = &ia->ia_addr.sin6_addr; 1624 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1625 if (V_dad_enhanced == 0) 1626 ndopt_nonce = NULL; 1627 dp = nd6_dad_find(ifa, ndopt_nonce); 1628 if (dp == NULL) 1629 return; 1630 1631 dp->dad_ns_icount++; 1632 nd6_dad_rele(dp); 1633 } 1634 1635 static void 1636 nd6_dad_na_input(struct ifaddr *ifa) 1637 { 1638 struct dadq *dp; 1639 1640 if (ifa == NULL) 1641 panic("ifa == NULL in nd6_dad_na_input"); 1642 1643 dp = nd6_dad_find(ifa, NULL); 1644 if (dp != NULL) { 1645 dp->dad_na_icount++; 1646 nd6_dad_rele(dp); 1647 } 1648 } 1649