1 /* $FreeBSD: src/sys/netinet6/nd6_nbr.c,v 1.4.2.6 2003/01/23 21:06:47 sam Exp $ */ 2 /* $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include "opt_inet.h" 34 #include "opt_inet6.h" 35 #include "opt_ipsec.h" 36 #include "opt_carp.h" 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/malloc.h> 41 #include <sys/mbuf.h> 42 #include <sys/socket.h> 43 #include <sys/sockio.h> 44 #include <sys/time.h> 45 #include <sys/kernel.h> 46 #include <sys/errno.h> 47 #include <sys/syslog.h> 48 #include <sys/queue.h> 49 #include <sys/callout.h> 50 #include <sys/mutex.h> 51 52 #include <sys/thread2.h> 53 #include <sys/mutex2.h> 54 55 #include <net/if.h> 56 #include <net/if_types.h> 57 #include <net/if_dl.h> 58 #include <net/route.h> 59 60 #include <netinet/in.h> 61 #include <netinet/in_var.h> 62 #include <netinet6/in6_var.h> 63 #include <netinet/ip6.h> 64 #include <netinet6/ip6_var.h> 65 #include <netinet6/nd6.h> 66 #include <netinet/icmp6.h> 67 68 #ifdef IPSEC 69 #include <netinet6/ipsec.h> 70 #ifdef INET6 71 #include <netinet6/ipsec6.h> 72 #endif 73 #endif 74 75 #include <net/net_osdep.h> 76 77 #ifdef CARP 78 #include <netinet/ip_carp.h> 79 #endif 80 81 82 #define SDL(s) ((struct sockaddr_dl *)s) 83 84 struct dadq; 85 static struct dadq *nd6_dad_find (struct ifaddr *); 86 static void nd6_dad_starttimer (struct dadq *, int); 87 static void nd6_dad_stoptimer (struct dadq *); 88 static void nd6_dad_timer (struct ifaddr *); 89 static void nd6_dad_ns_output (struct dadq *, struct ifaddr *); 90 static void nd6_dad_ns_input (struct ifaddr *); 91 static void nd6_dad_na_input (struct ifaddr *); 92 93 static int dad_ignore_ns = 0; /* ignore NS in DAD - specwise incorrect*/ 94 static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */ 95 96 /* 97 * Input an Neighbor Solicitation Message. 98 * 99 * Based on RFC 2461 100 * Based on RFC 2462 (duplicated address detection) 101 */ 102 void 103 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 104 { 105 struct ifnet *ifp = m->m_pkthdr.rcvif; 106 struct ifnet *cmpifp; 107 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 108 struct nd_neighbor_solicit *nd_ns; 109 struct in6_addr saddr6 = ip6->ip6_src; 110 struct in6_addr daddr6 = ip6->ip6_dst; 111 struct in6_addr taddr6; 112 struct in6_addr myaddr6; 113 char *lladdr = NULL; 114 struct ifaddr *ifa = NULL; 115 int lladdrlen = 0; 116 int anycast = 0, proxy = 0, tentative = 0; 117 int tlladdr; 118 union nd_opts ndopts; 119 struct sockaddr_dl *proxydl = NULL; 120 121 /* 122 * Collapse interfaces to the bridge for comparison and 123 * mac (llinfo) purposes. 124 */ 125 cmpifp = ifp; 126 if (ifp->if_bridge) 127 cmpifp = ifp->if_bridge; 128 129 #ifndef PULLDOWN_TEST 130 IP6_EXTHDR_CHECK(m, off, icmp6len,); 131 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 132 #else 133 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); 134 if (nd_ns == NULL) { 135 icmp6stat.icp6s_tooshort++; 136 return; 137 } 138 #endif 139 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ 140 taddr6 = nd_ns->nd_ns_target; 141 142 if (ip6->ip6_hlim != 255) { 143 nd6log((LOG_ERR, 144 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 145 ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src), 146 ip6_sprintf(&ip6->ip6_dst), if_name(ifp))); 147 goto bad; 148 } 149 150 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 151 /* dst has to be solicited node multicast address. */ 152 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL 153 /* don't check ifindex portion */ 154 && daddr6.s6_addr32[1] == 0 155 && daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE 156 && daddr6.s6_addr8[12] == 0xff) { 157 ; /* good */ 158 } else { 159 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 160 "(wrong ip6 dst)\n")); 161 goto bad; 162 } 163 } else { 164 /* 165 * Make sure the source address is from a neighbor's address. 166 * 167 * XXX probably only need to check cmpifp. 168 */ 169 if (in6ifa_ifplocaladdr(cmpifp, &saddr6) == NULL && 170 in6ifa_ifplocaladdr(ifp, &saddr6) == NULL) { 171 nd6log((LOG_INFO, "nd6_ns_input: " 172 "NS packet from non-neighbor\n")); 173 goto bad; 174 } 175 } 176 177 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 178 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 179 goto bad; 180 } 181 182 if (IN6_IS_SCOPE_LINKLOCAL(&taddr6)) 183 taddr6.s6_addr16[1] = htons(ifp->if_index); 184 185 icmp6len -= sizeof(*nd_ns); 186 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 187 if (nd6_options(&ndopts) < 0) { 188 nd6log((LOG_INFO, 189 "nd6_ns_input: invalid ND option, ignored\n")); 190 /* nd6_options have incremented stats */ 191 goto freeit; 192 } 193 194 if (ndopts.nd_opts_src_lladdr) { 195 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 196 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 197 } 198 199 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 200 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 201 "(link-layer address option)\n")); 202 goto bad; 203 } 204 205 /* 206 * Attaching target link-layer address to the NA? 207 * (RFC 2461 7.2.4) 208 * 209 * NS IP dst is unicast/anycast MUST NOT add 210 * NS IP dst is solicited-node multicast MUST add 211 * 212 * In implementation, we add target link-layer address by default. 213 * We do not add one in MUST NOT cases. 214 */ 215 #if 0 /* too much! */ 216 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &daddr6); 217 if (ifa && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)) 218 tlladdr = 0; 219 else 220 #endif 221 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 222 tlladdr = 0; 223 else 224 tlladdr = 1; 225 226 /* 227 * Target address (taddr6) must be either: 228 * (1) Valid unicast/anycast address for my receiving interface. 229 * (2) Unicast or anycast address for which I'm offering proxy 230 * service. 231 * (3) "tentative" address on which DAD is being performed. 232 */ 233 /* (1) and (3) check. */ 234 #ifdef CARP 235 if (ifp->if_carp) 236 ifa = carp_iamatch6(ifp->if_carp, &taddr6); 237 if (!ifa) 238 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 239 #else 240 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 241 #endif 242 243 /* 244 * (2) Check proxying. Requires ip6_forwarding to be turned on. 245 * 246 * If the packet is anycast the target route must be on a 247 * different interface because the anycast will get anything 248 * on the current interface. 249 * 250 * If the packet is unicast the target route may be on the 251 * same interface. If the gateway is a (typically manually 252 * configured) link address we can directly offer it. 253 * XXX for now we don't do this but instead offer ours and 254 * presumably relay. 255 * 256 * WARNING! Since this is a subnet proxy the interface proxying 257 * the ND6 must be in promiscuous mode or it will not see the 258 * solicited multicast requests for various hosts being proxied. 259 * 260 * WARNING! Since this is a subnet proxy we have to treat bridge 261 * interfaces as being the bridge itself so we do not proxy-nd6 262 * between bridge interfaces (which are effectively switched). 263 * 264 * (In the specific-host-proxy case via RTF_ANNOUNCE, which is 265 * a bitch to configure, a specific multicast route is already 266 * added for that host <-- NOT RECOMMENDED). 267 */ 268 if (!ifa && ip6_forwarding) { 269 struct rtentry *rt; 270 struct sockaddr_in6 tsin6; 271 struct ifnet *rtifp; 272 273 bzero(&tsin6, sizeof tsin6); 274 tsin6.sin6_len = sizeof(struct sockaddr_in6); 275 tsin6.sin6_family = AF_INET6; 276 tsin6.sin6_addr = taddr6; 277 278 rt = rtpurelookup((struct sockaddr *)&tsin6); 279 rtifp = rt ? rt->rt_ifp : NULL; 280 if (rtifp && rtifp->if_bridge) 281 rtifp = rtifp->if_bridge; 282 283 if (rt != NULL && 284 (cmpifp != rtifp || 285 (cmpifp == rtifp && (m->m_flags & M_MCAST) == 0)) 286 ) { 287 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(cmpifp, 288 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 289 nd6log((LOG_INFO, 290 "nd6_ns_input: nd6 proxy %s(%s)<-%s ifa %p\n", 291 if_name(cmpifp), if_name(ifp), 292 if_name(rtifp), ifa)); 293 if (ifa) { 294 proxy = 1; 295 /* 296 * Manual link address on same interface 297 * w/announce flag will proxy-arp using 298 * target mac, else our mac is used. 299 */ 300 if (cmpifp == rtifp && 301 (rt->rt_flags & RTF_ANNOUNCE) && 302 rt->rt_gateway->sa_family == AF_LINK) { 303 proxydl = SDL(rt->rt_gateway); 304 } 305 } 306 } 307 if (rt != NULL) 308 --rt->rt_refcnt; 309 } 310 if (ifa == NULL) { 311 /* 312 * We've got an NS packet, and we don't have that adddress 313 * assigned for us. We MUST silently ignore it. 314 * See RFC2461 7.2.3. 315 */ 316 goto freeit; 317 } 318 myaddr6 = *IFA_IN6(ifa); 319 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 320 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 321 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 322 goto freeit; 323 324 if (lladdr && ((cmpifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 325 nd6log((LOG_INFO, 326 "nd6_ns_input: lladdrlen mismatch for %s " 327 "(if %d, NS packet %d)\n", 328 ip6_sprintf(&taddr6), cmpifp->if_addrlen, lladdrlen - 2)); 329 goto bad; 330 } 331 332 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 333 nd6log((LOG_INFO, 334 "nd6_ns_input: duplicate IP6 address %s\n", 335 ip6_sprintf(&saddr6))); 336 goto freeit; 337 } 338 339 /* 340 * We have neighbor solicitation packet, with target address equals to 341 * one of my tentative address. 342 * 343 * src addr how to process? 344 * --- --- 345 * multicast of course, invalid (rejected in ip6_input) 346 * unicast somebody is doing address resolution -> ignore 347 * unspec dup address detection 348 * 349 * The processing is defined in RFC 2462. 350 */ 351 if (tentative) { 352 /* 353 * If source address is unspecified address, it is for 354 * duplicated address detection. 355 * 356 * If not, the packet is for addess resolution; 357 * silently ignore it. 358 */ 359 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 360 nd6_dad_ns_input(ifa); 361 362 goto freeit; 363 } 364 365 /* 366 * If the source address is unspecified address, entries must not 367 * be created or updated. 368 * It looks that sender is performing DAD. Output NA toward 369 * all-node multicast address, to tell the sender that I'm using 370 * the address. 371 * S bit ("solicited") must be zero. 372 */ 373 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 374 saddr6 = kin6addr_linklocal_allnodes; 375 saddr6.s6_addr16[1] = htons(cmpifp->if_index); 376 nd6_na_output(cmpifp, &saddr6, &taddr6, 377 ((anycast || proxy || !tlladdr) 378 ? 0 : ND_NA_FLAG_OVERRIDE) 379 | (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0), 380 tlladdr, (struct sockaddr *)proxydl); 381 goto freeit; 382 } 383 384 nd6_cache_lladdr(cmpifp, &saddr6, lladdr, 385 lladdrlen, ND_NEIGHBOR_SOLICIT, 0); 386 387 nd6_na_output(ifp, &saddr6, &taddr6, 388 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) 389 | (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0) 390 | ND_NA_FLAG_SOLICITED, 391 tlladdr, (struct sockaddr *)proxydl); 392 freeit: 393 m_freem(m); 394 return; 395 396 bad: 397 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", ip6_sprintf(&saddr6))); 398 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", ip6_sprintf(&daddr6))); 399 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", ip6_sprintf(&taddr6))); 400 icmp6stat.icp6s_badns++; 401 m_freem(m); 402 } 403 404 /* 405 * Output an Neighbor Solicitation Message. Caller specifies: 406 * - ICMP6 header source IP6 address 407 * - ND6 header target IP6 address 408 * - ND6 header source datalink address 409 * 410 * Based on RFC 2461 411 * Based on RFC 2462 (duplicated address detection) 412 */ 413 void 414 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6, 415 const struct in6_addr *taddr6, 416 struct llinfo_nd6 *ln, /* for source address determination */ 417 int dad) /* duplicated address detection */ 418 { 419 struct mbuf *m; 420 struct ip6_hdr *ip6; 421 struct nd_neighbor_solicit *nd_ns; 422 struct in6_ifaddr *ia = NULL; 423 struct ip6_moptions im6o; 424 int icmp6len; 425 int maxlen; 426 caddr_t mac; 427 struct ifnet *outif = NULL; 428 429 if (IN6_IS_ADDR_MULTICAST(taddr6)) 430 return; 431 432 /* estimate the size of message */ 433 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 434 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 435 if (max_linkhdr + maxlen >= MCLBYTES) { 436 #ifdef DIAGNOSTIC 437 kprintf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES " 438 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES); 439 #endif 440 return; 441 } 442 443 m = m_getb(max_linkhdr + maxlen, MB_DONTWAIT, MT_DATA, M_PKTHDR); 444 if (m == NULL) 445 return; 446 447 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 448 m->m_flags |= M_MCAST; 449 im6o.im6o_multicast_ifp = ifp; 450 im6o.im6o_multicast_hlim = 255; 451 im6o.im6o_multicast_loop = 0; 452 } 453 454 icmp6len = sizeof(*nd_ns); 455 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 456 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 457 458 /* fill neighbor solicitation packet */ 459 ip6 = mtod(m, struct ip6_hdr *); 460 ip6->ip6_flow = 0; 461 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 462 ip6->ip6_vfc |= IPV6_VERSION; 463 /* ip6->ip6_plen will be set later */ 464 ip6->ip6_nxt = IPPROTO_ICMPV6; 465 ip6->ip6_hlim = 255; 466 if (daddr6) 467 ip6->ip6_dst = *daddr6; 468 else { 469 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 470 ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index); 471 ip6->ip6_dst.s6_addr32[1] = 0; 472 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 473 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 474 ip6->ip6_dst.s6_addr8[12] = 0xff; 475 } 476 if (!dad) { 477 #if 0 /* KAME way, exact address scope match */ 478 /* 479 * Select a source whose scope is the same as that of the dest. 480 * Typically, the dest is link-local solicitation multicast 481 * (i.e. neighbor discovery) or link-local/global unicast 482 * (i.e. neighbor un-reachability detection). 483 */ 484 ia = in6_ifawithifp(ifp, &ip6->ip6_dst); 485 if (ia == NULL) { 486 m_freem(m); 487 return; 488 } 489 ip6->ip6_src = ia->ia_addr.sin6_addr; 490 #else /* spec-wise correct */ 491 /* 492 * RFC2461 7.2.2: 493 * "If the source address of the packet prompting the 494 * solicitation is the same as one of the addresses assigned 495 * to the outgoing interface, that address SHOULD be placed 496 * in the IP Source Address of the outgoing solicitation. 497 * Otherwise, any one of the addresses assigned to the 498 * interface should be used." 499 * 500 * We use the source address for the prompting packet 501 * (saddr6), if: 502 * - saddr6 is given from the caller (by giving "ln"), and 503 * - saddr6 belongs to the outgoing interface. 504 * Otherwise, we perform a scope-wise match. 505 */ 506 struct ip6_hdr *hip6; /* hold ip6 */ 507 struct in6_addr *saddr6; 508 509 if (ln && ln->ln_hold) { 510 hip6 = mtod(ln->ln_hold, struct ip6_hdr *); 511 /* XXX pullup? */ 512 if (sizeof(*hip6) < ln->ln_hold->m_len) 513 saddr6 = &hip6->ip6_src; 514 else 515 saddr6 = NULL; 516 } else 517 saddr6 = NULL; 518 if (saddr6 && in6ifa_ifpwithaddr(ifp, saddr6)) 519 bcopy(saddr6, &ip6->ip6_src, sizeof(*saddr6)); 520 else { 521 ia = in6_ifawithifp(ifp, &ip6->ip6_dst); 522 if (ia == NULL) { 523 m_freem(m); 524 return; 525 } 526 ip6->ip6_src = ia->ia_addr.sin6_addr; 527 } 528 #endif 529 } else { 530 /* 531 * Source address for DAD packet must always be IPv6 532 * unspecified address. (0::0) 533 */ 534 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 535 } 536 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 537 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 538 nd_ns->nd_ns_code = 0; 539 nd_ns->nd_ns_reserved = 0; 540 nd_ns->nd_ns_target = *taddr6; 541 542 if (IN6_IS_SCOPE_LINKLOCAL(&nd_ns->nd_ns_target)) 543 nd_ns->nd_ns_target.s6_addr16[1] = 0; 544 545 /* 546 * Add source link-layer address option. 547 * 548 * spec implementation 549 * --- --- 550 * DAD packet MUST NOT do not add the option 551 * there's no link layer address: 552 * impossible do not add the option 553 * there's link layer address: 554 * Multicast NS MUST add one add the option 555 * Unicast NS SHOULD add one add the option 556 */ 557 if (!dad && (mac = nd6_ifptomac(ifp))) { 558 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 559 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 560 /* 8 byte alignments... */ 561 optlen = (optlen + 7) & ~7; 562 563 m->m_pkthdr.len += optlen; 564 m->m_len += optlen; 565 icmp6len += optlen; 566 bzero((caddr_t)nd_opt, optlen); 567 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 568 nd_opt->nd_opt_len = optlen >> 3; 569 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 570 } 571 572 ip6->ip6_plen = htons((u_short)icmp6len); 573 nd_ns->nd_ns_cksum = 0; 574 nd_ns->nd_ns_cksum 575 = in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 576 577 ip6_output(m, NULL, NULL, dad ? IPV6_DADOUTPUT : 0, &im6o, &outif, NULL); 578 if (outif) { 579 icmp6_ifstat_inc(outif, ifs6_out_msg); 580 icmp6_ifstat_inc(outif, ifs6_out_neighborsolicit); 581 } 582 icmp6stat.icp6s_outhist[ND_NEIGHBOR_SOLICIT]++; 583 } 584 585 /* 586 * Neighbor advertisement input handling. 587 * 588 * Based on RFC 2461 589 * Based on RFC 2462 (duplicated address detection) 590 * 591 * the following items are not implemented yet: 592 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 593 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 594 */ 595 void 596 nd6_na_input(struct mbuf *m, int off, int icmp6len) 597 { 598 struct ifnet *ifp = m->m_pkthdr.rcvif; 599 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 600 struct nd_neighbor_advert *nd_na; 601 struct in6_addr saddr6 = ip6->ip6_src; 602 struct in6_addr daddr6 = ip6->ip6_dst; 603 struct in6_addr taddr6; 604 int flags; 605 int is_router; 606 int is_solicited; 607 int is_override; 608 char *lladdr = NULL; 609 int lladdrlen = 0; 610 struct ifaddr *ifa; 611 struct llinfo_nd6 *ln; 612 struct rtentry *rt; 613 struct sockaddr_dl *sdl; 614 union nd_opts ndopts; 615 616 if (ip6->ip6_hlim != 255) { 617 nd6log((LOG_ERR, 618 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 619 ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src), 620 ip6_sprintf(&ip6->ip6_dst), if_name(ifp))); 621 goto bad; 622 } 623 624 #ifndef PULLDOWN_TEST 625 IP6_EXTHDR_CHECK(m, off, icmp6len,); 626 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 627 #else 628 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 629 if (nd_na == NULL) { 630 icmp6stat.icp6s_tooshort++; 631 return; 632 } 633 #endif 634 taddr6 = nd_na->nd_na_target; 635 flags = nd_na->nd_na_flags_reserved; 636 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 637 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 638 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 639 640 if (IN6_IS_SCOPE_LINKLOCAL(&taddr6)) 641 taddr6.s6_addr16[1] = htons(ifp->if_index); 642 643 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 644 nd6log((LOG_ERR, 645 "nd6_na_input: invalid target address %s\n", 646 ip6_sprintf(&taddr6))); 647 goto bad; 648 } 649 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 650 if (is_solicited) { 651 nd6log((LOG_ERR, 652 "nd6_na_input: a solicited adv is multicasted\n")); 653 goto bad; 654 } 655 656 icmp6len -= sizeof(*nd_na); 657 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 658 if (nd6_options(&ndopts) < 0) { 659 nd6log((LOG_INFO, 660 "nd6_na_input: invalid ND option, ignored\n")); 661 /* nd6_options have incremented stats */ 662 goto freeit; 663 } 664 665 if (ndopts.nd_opts_tgt_lladdr) { 666 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 667 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 668 } 669 670 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 671 672 /* 673 * Target address matches one of my interface address. 674 * 675 * If my address is tentative, this means that there's somebody 676 * already using the same address as mine. This indicates DAD failure. 677 * This is defined in RFC 2462. 678 * 679 * Otherwise, process as defined in RFC 2461. 680 */ 681 if (ifa 682 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 683 nd6_dad_na_input(ifa); 684 goto freeit; 685 } 686 687 /* Just for safety, maybe unnecessary. */ 688 if (ifa) { 689 log(LOG_ERR, 690 "nd6_na_input: duplicate IP6 address %s\n", 691 ip6_sprintf(&taddr6)); 692 goto freeit; 693 } 694 695 /* 696 * Make sure the source address is from a neighbor's address. 697 */ 698 if (in6ifa_ifplocaladdr(ifp, &saddr6) == NULL) { 699 nd6log((LOG_INFO, "nd6_na_input: " 700 "NA packet from non-neighbor\n")); 701 goto bad; 702 } 703 704 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 705 nd6log((LOG_INFO, 706 "nd6_na_input: lladdrlen mismatch for %s " 707 "(if %d, NA packet %d)\n", 708 ip6_sprintf(&taddr6), ifp->if_addrlen, lladdrlen - 2)); 709 goto bad; 710 } 711 712 /* 713 * If no neighbor cache entry is found, NA SHOULD silently be discarded. 714 */ 715 rt = nd6_lookup(&taddr6, 0, ifp); 716 if ((rt == NULL) || 717 ((ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) || 718 ((sdl = SDL(rt->rt_gateway)) == NULL)) 719 goto freeit; 720 721 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 722 /* 723 * If the link-layer has address, and no lladdr option came, 724 * discard the packet. 725 */ 726 if (ifp->if_addrlen && !lladdr) 727 goto freeit; 728 729 /* 730 * Record link-layer address, and update the state. 731 */ 732 sdl->sdl_alen = ifp->if_addrlen; 733 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); 734 if (is_solicited) { 735 ln->ln_state = ND6_LLINFO_REACHABLE; 736 ln->ln_byhint = 0; 737 if (ln->ln_expire) 738 ln->ln_expire = time_uptime + 739 ND_IFINFO(rt->rt_ifp)->reachable; 740 } else { 741 ln->ln_state = ND6_LLINFO_STALE; 742 ln->ln_expire = time_uptime + nd6_gctimer; 743 } 744 if ((ln->ln_router = is_router) != 0) { 745 /* 746 * This means a router's state has changed from 747 * non-reachable to probably reachable, and might 748 * affect the status of associated prefixes.. 749 */ 750 pfxlist_onlink_check(); 751 } 752 } else { 753 int llchange; 754 755 /* 756 * Check if the link-layer address has changed or not. 757 */ 758 if (!lladdr) 759 llchange = 0; 760 else { 761 if (sdl->sdl_alen) { 762 if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen)) 763 llchange = 1; 764 else 765 llchange = 0; 766 } else 767 llchange = 1; 768 } 769 770 /* 771 * This is VERY complex. Look at it with care. 772 * 773 * override solicit lladdr llchange action 774 * (L: record lladdr) 775 * 776 * 0 0 n -- (2c) 777 * 0 0 y n (2b) L 778 * 0 0 y y (1) REACHABLE->STALE 779 * 0 1 n -- (2c) *->REACHABLE 780 * 0 1 y n (2b) L *->REACHABLE 781 * 0 1 y y (1) REACHABLE->STALE 782 * 1 0 n -- (2a) 783 * 1 0 y n (2a) L 784 * 1 0 y y (2a) L *->STALE 785 * 1 1 n -- (2a) *->REACHABLE 786 * 1 1 y n (2a) L *->REACHABLE 787 * 1 1 y y (2a) L *->REACHABLE 788 */ 789 if (!is_override && (lladdr && llchange)) { /* (1) */ 790 /* 791 * If state is REACHABLE, make it STALE. 792 * no other updates should be done. 793 */ 794 if (ln->ln_state == ND6_LLINFO_REACHABLE) { 795 ln->ln_state = ND6_LLINFO_STALE; 796 ln->ln_expire = time_uptime + nd6_gctimer; 797 } 798 goto freeit; 799 } else if (is_override /* (2a) */ 800 || (!is_override && (lladdr && !llchange)) /* (2b) */ 801 || !lladdr) { /* (2c) */ 802 /* 803 * Update link-local address, if any. 804 */ 805 if (lladdr) { 806 sdl->sdl_alen = ifp->if_addrlen; 807 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); 808 } 809 810 /* 811 * If solicited, make the state REACHABLE. 812 * If not solicited and the link-layer address was 813 * changed, make it STALE. 814 */ 815 if (is_solicited) { 816 ln->ln_state = ND6_LLINFO_REACHABLE; 817 ln->ln_byhint = 0; 818 if (ln->ln_expire) { 819 ln->ln_expire = time_uptime + 820 ND_IFINFO(ifp)->reachable; 821 } 822 } else { 823 if (lladdr && llchange) { 824 ln->ln_state = ND6_LLINFO_STALE; 825 ln->ln_expire = time_uptime + nd6_gctimer; 826 } 827 } 828 } 829 830 if (ln->ln_router && !is_router) { 831 /* 832 * The peer dropped the router flag. 833 * Remove the sender from the Default Router List and 834 * update the Destination Cache entries. 835 */ 836 struct nd_defrouter *dr; 837 struct in6_addr *in6; 838 839 in6 = &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr; 840 841 /* 842 * Lock to protect the default router list. 843 * XXX: this might be unnecessary, since this function 844 * is only called under the network software interrupt 845 * context. However, we keep it just for safety. 846 */ 847 mtx_lock(&nd6_mtx); 848 dr = defrouter_lookup(in6, rt->rt_ifp); 849 if (dr) 850 defrtrlist_del(dr); 851 mtx_unlock(&nd6_mtx); 852 853 if (dr == NULL && !ip6_forwarding && ip6_accept_rtadv) { 854 /* 855 * Even if the neighbor is not in the default 856 * router list, the neighbor may be used 857 * as a next hop for some destinations 858 * (e.g. redirect case). So we must 859 * call rt6_flush explicitly. 860 */ 861 rt6_flush(&ip6->ip6_src, rt->rt_ifp); 862 } 863 } 864 ln->ln_router = is_router; 865 } 866 rt->rt_flags &= ~RTF_REJECT; 867 ln->ln_asked = 0; 868 if (ln->ln_hold) { 869 /* 870 * we assume ifp is not a loopback here, so just set the 2nd 871 * argument as the 1st one. 872 */ 873 nd6_output(ifp, ifp, ln->ln_hold, 874 (struct sockaddr_in6 *)rt_key(rt), rt); 875 ln->ln_hold = 0; 876 } 877 878 freeit: 879 m_freem(m); 880 return; 881 882 bad: 883 icmp6stat.icp6s_badna++; 884 m_freem(m); 885 } 886 887 /* 888 * Neighbor advertisement output handling. 889 * 890 * Based on RFC 2461 891 * 892 * the following items are not implemented yet: 893 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 894 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 895 */ 896 void 897 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6, 898 const struct in6_addr *taddr6, u_long flags, 899 int tlladdr, /* 1 if include target link-layer address */ 900 struct sockaddr *sdl0) /* sockaddr_dl (= proxy NA) or NULL */ 901 { 902 struct mbuf *m; 903 struct ip6_hdr *ip6; 904 struct nd_neighbor_advert *nd_na; 905 struct in6_ifaddr *ia = NULL; 906 struct ip6_moptions im6o; 907 int icmp6len; 908 int maxlen; 909 caddr_t mac; 910 struct ifnet *outif = NULL; 911 912 /* estimate the size of message */ 913 maxlen = sizeof(*ip6) + sizeof(*nd_na); 914 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 915 if (max_linkhdr + maxlen >= MCLBYTES) { 916 #ifdef DIAGNOSTIC 917 kprintf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES " 918 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES); 919 #endif 920 return; 921 } 922 923 m = m_getb(max_linkhdr + maxlen, MB_DONTWAIT, MT_DATA, M_PKTHDR); 924 if (m == NULL) 925 return; 926 927 if (IN6_IS_ADDR_MULTICAST(daddr6)) { 928 m->m_flags |= M_MCAST; 929 im6o.im6o_multicast_ifp = ifp; 930 im6o.im6o_multicast_hlim = 255; 931 im6o.im6o_multicast_loop = 0; 932 } 933 934 icmp6len = sizeof(*nd_na); 935 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 936 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 937 938 /* fill neighbor advertisement packet */ 939 ip6 = mtod(m, struct ip6_hdr *); 940 ip6->ip6_flow = 0; 941 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 942 ip6->ip6_vfc |= IPV6_VERSION; 943 ip6->ip6_nxt = IPPROTO_ICMPV6; 944 ip6->ip6_hlim = 255; 945 if (IN6_IS_ADDR_UNSPECIFIED(daddr6)) { 946 /* reply to DAD */ 947 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 948 ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index); 949 ip6->ip6_dst.s6_addr32[1] = 0; 950 ip6->ip6_dst.s6_addr32[2] = 0; 951 ip6->ip6_dst.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 952 flags &= ~ND_NA_FLAG_SOLICITED; 953 } else 954 ip6->ip6_dst = *daddr6; 955 956 /* 957 * Select a source whose scope is the same as that of the dest. 958 */ 959 ia = in6_ifawithifp(ifp, &ip6->ip6_dst); 960 if (ia == NULL) { 961 m_freem(m); 962 return; 963 } 964 ip6->ip6_src = ia->ia_addr.sin6_addr; 965 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 966 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 967 nd_na->nd_na_code = 0; 968 nd_na->nd_na_target = *taddr6; 969 if (IN6_IS_SCOPE_LINKLOCAL(&nd_na->nd_na_target)) 970 nd_na->nd_na_target.s6_addr16[1] = 0; 971 972 /* 973 * "tlladdr" indicates NS's condition for adding tlladdr or not. 974 * see nd6_ns_input() for details. 975 * Basically, if NS packet is sent to unicast/anycast addr, 976 * target lladdr option SHOULD NOT be included. 977 */ 978 mac = NULL; 979 if (tlladdr) { 980 /* 981 * sdl0 != NULL indicates proxy NA. If we do proxy, use 982 * lladdr in sdl0. If we are not proxying (sending NA for 983 * my address) use lladdr configured for the interface. 984 */ 985 if (sdl0 == NULL) { 986 #ifdef CARP 987 if (ifp->if_carp) 988 mac = carp_macmatch6(ifp->if_carp, m, taddr6); 989 if (mac == NULL) 990 mac = nd6_ifptomac(ifp); 991 #else 992 mac = nd6_ifptomac(ifp); 993 #endif 994 } else if (sdl0->sa_family == AF_LINK) { 995 struct sockaddr_dl *sdl; 996 sdl = (struct sockaddr_dl *)sdl0; 997 if (sdl->sdl_alen == ifp->if_addrlen) 998 mac = LLADDR(sdl); 999 } 1000 } 1001 if (mac != NULL) { 1002 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1003 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1004 1005 /* roundup to 8 bytes alignment! */ 1006 optlen = (optlen + 7) & ~7; 1007 1008 m->m_pkthdr.len += optlen; 1009 m->m_len += optlen; 1010 icmp6len += optlen; 1011 bzero((caddr_t)nd_opt, optlen); 1012 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1013 nd_opt->nd_opt_len = optlen >> 3; 1014 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1015 } else 1016 flags &= ~ND_NA_FLAG_OVERRIDE; 1017 1018 ip6->ip6_plen = htons((u_short)icmp6len); 1019 nd_na->nd_na_flags_reserved = flags; 1020 nd_na->nd_na_cksum = 0; 1021 nd_na->nd_na_cksum = 1022 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1023 1024 ip6_output(m, NULL, NULL, 0, &im6o, &outif, NULL); 1025 if (outif) { 1026 icmp6_ifstat_inc(outif, ifs6_out_msg); 1027 icmp6_ifstat_inc(outif, ifs6_out_neighboradvert); 1028 } 1029 icmp6stat.icp6s_outhist[ND_NEIGHBOR_ADVERT]++; 1030 } 1031 1032 caddr_t 1033 nd6_ifptomac(struct ifnet *ifp) 1034 { 1035 switch (ifp->if_type) { 1036 case IFT_ETHER: 1037 case IFT_IEEE1394: 1038 #ifdef IFT_L2VLAN 1039 case IFT_L2VLAN: 1040 #endif 1041 #ifdef IFT_IEEE80211 1042 case IFT_IEEE80211: 1043 #endif 1044 #ifdef IFT_CARP 1045 case IFT_CARP: 1046 #endif 1047 return ((caddr_t)(ifp + 1)); 1048 break; 1049 default: 1050 return NULL; 1051 } 1052 } 1053 1054 TAILQ_HEAD(dadq_head, dadq); 1055 struct dadq { 1056 TAILQ_ENTRY(dadq) dad_list; 1057 struct ifaddr *dad_ifa; 1058 int dad_count; /* max NS to send */ 1059 int dad_ns_tcount; /* # of trials to send NS */ 1060 int dad_ns_ocount; /* NS sent so far */ 1061 int dad_ns_icount; 1062 int dad_na_icount; 1063 struct callout dad_timer_ch; 1064 }; 1065 1066 static struct dadq_head dadq; 1067 static int dad_init = 0; 1068 1069 static struct dadq * 1070 nd6_dad_find(struct ifaddr *ifa) 1071 { 1072 struct dadq *dp; 1073 1074 TAILQ_FOREACH(dp, &dadq, dad_list) { 1075 if (dp->dad_ifa == ifa) 1076 return dp; 1077 } 1078 return NULL; 1079 } 1080 1081 static void 1082 nd6_dad_starttimer(struct dadq *dp, int ticks) 1083 { 1084 1085 callout_reset(&dp->dad_timer_ch, ticks, 1086 (void (*) (void *))nd6_dad_timer, (void *)dp->dad_ifa); 1087 } 1088 1089 static void 1090 nd6_dad_stoptimer(struct dadq *dp) 1091 { 1092 1093 callout_stop(&dp->dad_timer_ch); 1094 } 1095 1096 /* 1097 * Start Duplicated Address Detection (DAD) for specified interface address. 1098 */ 1099 void 1100 nd6_dad_start(struct ifaddr *ifa, 1101 int *tick) /* minimum delay ticks for IFF_UP event */ 1102 { 1103 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1104 struct dadq *dp; 1105 1106 if (!dad_init) { 1107 TAILQ_INIT(&dadq); 1108 dad_init++; 1109 } 1110 1111 /* 1112 * If we don't need DAD, don't do it. 1113 * There are several cases: 1114 * - DAD is disabled (ip6_dad_count == 0) 1115 * - the interface address is anycast 1116 */ 1117 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1118 log(LOG_DEBUG, 1119 "nd6_dad_start: called with non-tentative address " 1120 "%s(%s)\n", 1121 ip6_sprintf(&ia->ia_addr.sin6_addr), 1122 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1123 return; 1124 } 1125 if (ia->ia6_flags & IN6_IFF_ANYCAST) { 1126 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1127 return; 1128 } 1129 if (!ip6_dad_count) { 1130 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1131 return; 1132 } 1133 if (!ifa->ifa_ifp) 1134 panic("nd6_dad_start: ifa->ifa_ifp == NULL"); 1135 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1136 return; 1137 if (nd6_dad_find(ifa) != NULL) { 1138 /* DAD already in progress */ 1139 return; 1140 } 1141 1142 dp = kmalloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1143 if (dp == NULL) { 1144 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1145 "%s(%s)\n", 1146 ip6_sprintf(&ia->ia_addr.sin6_addr), 1147 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1148 return; 1149 } 1150 callout_init(&dp->dad_timer_ch); 1151 TAILQ_INSERT_TAIL(&dadq, dp, dad_list); 1152 1153 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1154 ip6_sprintf(&ia->ia_addr.sin6_addr))); 1155 1156 /* 1157 * Send NS packet for DAD, ip6_dad_count times. 1158 * Note that we must delay the first transmission, if this is the 1159 * first packet to be sent from the interface after interface 1160 * (re)initialization. 1161 */ 1162 dp->dad_ifa = ifa; 1163 _IFAREF(ifa, 0); /* just for safety */ 1164 dp->dad_count = ip6_dad_count; 1165 dp->dad_ns_icount = dp->dad_na_icount = 0; 1166 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1167 if (tick == NULL) { 1168 nd6_dad_ns_output(dp, ifa); 1169 nd6_dad_starttimer(dp, 1170 ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1171 } else { 1172 int ntick; 1173 1174 if (*tick == 0) 1175 ntick = krandom() % (MAX_RTR_SOLICITATION_DELAY * hz); 1176 else 1177 ntick = *tick + krandom() % (hz / 2); 1178 *tick = ntick; 1179 nd6_dad_starttimer(dp, ntick); 1180 } 1181 } 1182 1183 /* 1184 * terminate DAD unconditionally. used for address removals. 1185 */ 1186 void 1187 nd6_dad_stop(struct ifaddr *ifa) 1188 { 1189 struct dadq *dp; 1190 1191 if (!dad_init) 1192 return; 1193 dp = nd6_dad_find(ifa); 1194 if (!dp) { 1195 /* DAD wasn't started yet */ 1196 return; 1197 } 1198 1199 nd6_dad_stoptimer(dp); 1200 1201 TAILQ_REMOVE(&dadq, dp, dad_list); 1202 kfree(dp, M_IP6NDP); 1203 dp = NULL; 1204 _IFAFREE(ifa, 0); 1205 } 1206 1207 static void 1208 nd6_dad_timer(struct ifaddr *ifa) 1209 { 1210 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1211 struct dadq *dp; 1212 1213 mtx_lock(&nd6_mtx); 1214 1215 /* Sanity check */ 1216 if (ia == NULL) { 1217 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n"); 1218 goto done; 1219 } 1220 dp = nd6_dad_find(ifa); 1221 if (dp == NULL) { 1222 log(LOG_ERR, "nd6_dad_timer: DAD structure not found\n"); 1223 goto done; 1224 } 1225 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1226 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1227 "%s(%s)\n", 1228 ip6_sprintf(&ia->ia_addr.sin6_addr), 1229 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1230 goto done; 1231 } 1232 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1233 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1234 "%s(%s)\n", 1235 ip6_sprintf(&ia->ia_addr.sin6_addr), 1236 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1237 goto done; 1238 } 1239 1240 /* timeouted with IFF_{RUNNING,UP} check */ 1241 if (dp->dad_ns_tcount > dad_maxtry) { 1242 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n", 1243 if_name(ifa->ifa_ifp))); 1244 1245 TAILQ_REMOVE(&dadq, dp, dad_list); 1246 kfree(dp, M_IP6NDP); 1247 dp = NULL; 1248 _IFAFREE(ifa, 0); 1249 goto done; 1250 } 1251 1252 /* Need more checks? */ 1253 if (dp->dad_ns_ocount < dp->dad_count) { 1254 /* 1255 * We have more NS to go. Send NS packet for DAD. 1256 */ 1257 nd6_dad_ns_output(dp, ifa); 1258 nd6_dad_starttimer(dp, 1259 ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1260 } else { 1261 /* 1262 * We have transmitted sufficient number of DAD packets. 1263 * See what we've got. 1264 */ 1265 int duplicate; 1266 1267 duplicate = 0; 1268 1269 if (dp->dad_na_icount) { 1270 /* 1271 * the check is in nd6_dad_na_input(), 1272 * but just in case 1273 */ 1274 duplicate++; 1275 } 1276 1277 if (dp->dad_ns_icount) { 1278 #if 0 /* heuristics */ 1279 /* 1280 * if 1281 * - we have sent many(?) DAD NS, and 1282 * - the number of NS we sent equals to the 1283 * number of NS we've got, and 1284 * - we've got no NA 1285 * we may have a faulty network card/driver which 1286 * loops back multicasts to myself. 1287 */ 1288 if (3 < dp->dad_count 1289 && dp->dad_ns_icount == dp->dad_count 1290 && dp->dad_na_icount == 0) { 1291 log(LOG_INFO, "DAD questionable for %s(%s): " 1292 "network card loops back multicast?\n", 1293 ip6_sprintf(&ia->ia_addr.sin6_addr), 1294 if_name(ifa->ifa_ifp)); 1295 /* XXX consider it a duplicate or not? */ 1296 /* duplicate++; */ 1297 } else { 1298 /* We've seen NS, means DAD has failed. */ 1299 duplicate++; 1300 } 1301 #else 1302 /* We've seen NS, means DAD has failed. */ 1303 duplicate++; 1304 #endif 1305 } 1306 1307 if (duplicate) { 1308 /* (*dp) will be freed in nd6_dad_duplicated() */ 1309 dp = NULL; 1310 nd6_dad_duplicated(ifa); 1311 } else { 1312 /* 1313 * We are done with DAD. No NA came, no NS came. 1314 * duplicated address found. 1315 */ 1316 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1317 1318 nd6log((LOG_DEBUG, 1319 "%s: DAD complete for %s - no duplicates found\n", 1320 if_name(ifa->ifa_ifp), 1321 ip6_sprintf(&ia->ia_addr.sin6_addr))); 1322 1323 TAILQ_REMOVE(&dadq, dp, dad_list); 1324 kfree(dp, M_IP6NDP); 1325 dp = NULL; 1326 _IFAFREE(ifa, 0); 1327 } 1328 } 1329 1330 done: 1331 mtx_unlock(&nd6_mtx); 1332 } 1333 1334 void 1335 nd6_dad_duplicated(struct ifaddr *ifa) 1336 { 1337 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1338 struct dadq *dp; 1339 1340 dp = nd6_dad_find(ifa); 1341 if (dp == NULL) { 1342 log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n"); 1343 return; 1344 } 1345 1346 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1347 "NS in/out=%d/%d, NA in=%d\n", 1348 if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr), 1349 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount); 1350 1351 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1352 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1353 1354 /* We are done with DAD, with duplicated address found. (failure) */ 1355 nd6_dad_stoptimer(dp); 1356 1357 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1358 if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr)); 1359 log(LOG_ERR, "%s: manual intervention required\n", 1360 if_name(ifa->ifa_ifp)); 1361 1362 TAILQ_REMOVE(&dadq, dp, dad_list); 1363 kfree(dp, M_IP6NDP); 1364 dp = NULL; 1365 _IFAFREE(ifa, 0); 1366 } 1367 1368 static void 1369 nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa) 1370 { 1371 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1372 struct ifnet *ifp = ifa->ifa_ifp; 1373 1374 dp->dad_ns_tcount++; 1375 if (!(ifp->if_flags & IFF_UP)) { 1376 #if 0 1377 kprintf("%s: interface down?\n", if_name(ifp)); 1378 #endif 1379 return; 1380 } 1381 if (!(ifp->if_flags & IFF_RUNNING)) { 1382 #if 0 1383 kprintf("%s: interface not running?\n", if_name(ifp)); 1384 #endif 1385 return; 1386 } 1387 1388 dp->dad_ns_ocount++; 1389 nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1); 1390 } 1391 1392 static void 1393 nd6_dad_ns_input(struct ifaddr *ifa) 1394 { 1395 struct in6_ifaddr *ia; 1396 const struct in6_addr *taddr6; 1397 struct dadq *dp; 1398 int duplicate; 1399 1400 if (!ifa) 1401 panic("ifa == NULL in nd6_dad_ns_input"); 1402 1403 ia = (struct in6_ifaddr *)ifa; 1404 taddr6 = &ia->ia_addr.sin6_addr; 1405 duplicate = 0; 1406 dp = nd6_dad_find(ifa); 1407 1408 /* Quickhack - completely ignore DAD NS packets */ 1409 if (dad_ignore_ns) { 1410 nd6log((LOG_INFO, 1411 "nd6_dad_ns_input: ignoring DAD NS packet for " 1412 "address %s(%s)\n", ip6_sprintf(taddr6), 1413 if_name(ifa->ifa_ifp))); 1414 return; 1415 } 1416 1417 /* 1418 * if I'm yet to start DAD, someone else started using this address 1419 * first. I have a duplicate and you win. 1420 */ 1421 if (!dp || dp->dad_ns_ocount == 0) 1422 duplicate++; 1423 1424 /* XXX more checks for loopback situation - see nd6_dad_timer too */ 1425 1426 if (duplicate) { 1427 dp = NULL; /* will be freed in nd6_dad_duplicated() */ 1428 nd6_dad_duplicated(ifa); 1429 } else { 1430 /* 1431 * not sure if I got a duplicate. 1432 * increment ns count and see what happens. 1433 */ 1434 if (dp) 1435 dp->dad_ns_icount++; 1436 } 1437 } 1438 1439 static void 1440 nd6_dad_na_input(struct ifaddr *ifa) 1441 { 1442 struct dadq *dp; 1443 1444 if (!ifa) 1445 panic("ifa == NULL in nd6_dad_na_input"); 1446 1447 dp = nd6_dad_find(ifa); 1448 if (dp) 1449 dp->dad_na_icount++; 1450 1451 /* remove the address. */ 1452 nd6_dad_duplicated(ifa); 1453 } 1454