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 #include <net/netisr2.h> 60 #include <net/netmsg2.h> 61 62 #include <netinet/in.h> 63 #include <netinet/in_var.h> 64 #include <netinet6/in6_var.h> 65 #include <netinet/ip6.h> 66 #include <netinet6/ip6_var.h> 67 #include <netinet6/nd6.h> 68 #include <netinet/icmp6.h> 69 70 #ifdef IPSEC 71 #include <netinet6/ipsec.h> 72 #ifdef INET6 73 #include <netinet6/ipsec6.h> 74 #endif 75 #endif 76 77 #include <net/net_osdep.h> 78 79 #ifdef CARP 80 #include <netinet/ip_carp.h> 81 #endif 82 83 84 #define SDL(s) ((struct sockaddr_dl *)s) 85 86 struct dadq; 87 static struct dadq *nd6_dad_find(struct ifaddr *); 88 static void nd6_dad_starttimer(struct dadq *, int); 89 static void nd6_dad_stoptimer(struct dadq *); 90 static void nd6_dad_timer(void *); 91 static void nd6_dad_timer_handler(netmsg_t); 92 static void nd6_dad_ns_output(struct dadq *); 93 static void nd6_dad_ns_input(struct ifaddr *); 94 static void nd6_dad_na_input(struct ifaddr *); 95 static struct dadq *nd6_dad_create(struct ifaddr *); 96 static void nd6_dad_destroy(struct dadq *); 97 static void nd6_dad_duplicated(struct ifaddr *); 98 99 static int dad_ignore_ns = 0; /* ignore NS in DAD - specwise incorrect*/ 100 static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */ 101 102 /* 103 * Input an Neighbor Solicitation Message. 104 * 105 * Based on RFC 2461 106 * Based on RFC 2462 (duplicated address detection) 107 */ 108 void 109 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 110 { 111 struct ifnet *ifp = m->m_pkthdr.rcvif; 112 struct ifnet *cmpifp; 113 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 114 struct nd_neighbor_solicit *nd_ns; 115 struct in6_addr saddr6 = ip6->ip6_src; 116 struct in6_addr daddr6 = ip6->ip6_dst; 117 struct in6_addr taddr6; 118 struct in6_addr myaddr6; 119 char *lladdr = NULL; 120 struct ifaddr *ifa = NULL; 121 int lladdrlen = 0; 122 int anycast = 0, proxy = 0, tentative = 0; 123 int tlladdr; 124 union nd_opts ndopts; 125 struct sockaddr_dl *proxydl = NULL; 126 127 /* 128 * Collapse interfaces to the bridge for comparison and 129 * mac (llinfo) purposes. 130 */ 131 cmpifp = ifp; 132 if (ifp->if_bridge) 133 cmpifp = ifp->if_bridge; 134 135 #ifndef PULLDOWN_TEST 136 IP6_EXTHDR_CHECK(m, off, icmp6len,); 137 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 138 #else 139 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); 140 if (nd_ns == NULL) { 141 icmp6stat.icp6s_tooshort++; 142 return; 143 } 144 #endif 145 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ 146 taddr6 = nd_ns->nd_ns_target; 147 148 if (ip6->ip6_hlim != 255) { 149 nd6log((LOG_ERR, 150 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 151 ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src), 152 ip6_sprintf(&ip6->ip6_dst), if_name(ifp))); 153 goto bad; 154 } 155 156 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 157 /* dst has to be solicited node multicast address. */ 158 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 159 /* don't check ifindex portion */ 160 daddr6.s6_addr32[1] == 0 && 161 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 162 daddr6.s6_addr8[12] == 0xff) { 163 ; /* good */ 164 } else { 165 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 166 "(wrong ip6 dst)\n")); 167 goto bad; 168 } 169 } else if (!nd6_onlink_ns_rfc4861) { 170 /* 171 * Make sure the source address is from a neighbor's address. 172 * 173 * XXX probably only need to check cmpifp. 174 */ 175 if (in6ifa_ifplocaladdr(cmpifp, &saddr6) == NULL && 176 in6ifa_ifplocaladdr(ifp, &saddr6) == NULL) { 177 nd6log((LOG_INFO, "nd6_ns_input: " 178 "NS packet from non-neighbor\n")); 179 goto bad; 180 } 181 } 182 183 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 184 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 185 goto bad; 186 } 187 188 if (IN6_IS_SCOPE_LINKLOCAL(&taddr6)) 189 taddr6.s6_addr16[1] = htons(ifp->if_index); 190 191 icmp6len -= sizeof(*nd_ns); 192 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 193 if (nd6_options(&ndopts) < 0) { 194 nd6log((LOG_INFO, 195 "nd6_ns_input: invalid ND option, ignored\n")); 196 /* nd6_options have incremented stats */ 197 goto freeit; 198 } 199 200 if (ndopts.nd_opts_src_lladdr) { 201 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 202 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 203 } 204 205 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 206 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 207 "(link-layer address option)\n")); 208 goto bad; 209 } 210 211 /* 212 * Attaching target link-layer address to the NA? 213 * (RFC 2461 7.2.4) 214 * 215 * NS IP dst is unicast/anycast MUST NOT add 216 * NS IP dst is solicited-node multicast MUST add 217 * 218 * In implementation, we add target link-layer address by default. 219 * We do not add one in MUST NOT cases. 220 */ 221 #if 0 /* too much! */ 222 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &daddr6); 223 if (ifa && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)) 224 tlladdr = 0; 225 else 226 #endif 227 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 228 tlladdr = 0; 229 else 230 tlladdr = 1; 231 232 /* 233 * Target address (taddr6) must be either: 234 * (1) Valid unicast/anycast address for my receiving interface. 235 * (2) Unicast or anycast address for which I'm offering proxy 236 * service. 237 * (3) "tentative" address on which DAD is being performed. 238 */ 239 /* (1) and (3) check. */ 240 #ifdef CARP 241 if (ifp->if_carp) 242 ifa = carp_iamatch6(ifp->if_carp, &taddr6); 243 if (!ifa) 244 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 245 #else 246 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 247 #endif 248 249 /* 250 * (2) Check proxying. Requires ip6_forwarding to be turned on. 251 * 252 * If the packet is anycast the target route must be on a 253 * different interface because the anycast will get anything 254 * on the current interface. 255 * 256 * If the packet is unicast the target route may be on the 257 * same interface. If the gateway is a (typically manually 258 * configured) link address we can directly offer it. 259 * XXX for now we don't do this but instead offer ours and 260 * presumably relay. 261 * 262 * WARNING! Since this is a subnet proxy the interface proxying 263 * the ND6 must be in promiscuous mode or it will not see the 264 * solicited multicast requests for various hosts being proxied. 265 * 266 * WARNING! Since this is a subnet proxy we have to treat bridge 267 * interfaces as being the bridge itself so we do not proxy-nd6 268 * between bridge interfaces (which are effectively switched). 269 * 270 * (In the specific-host-proxy case via RTF_ANNOUNCE, which is 271 * a bitch to configure, a specific multicast route is already 272 * added for that host <-- NOT RECOMMENDED). 273 */ 274 if (!ifa && ip6_forwarding) { 275 struct rtentry *rt; 276 struct sockaddr_in6 tsin6; 277 struct ifnet *rtifp; 278 279 bzero(&tsin6, sizeof tsin6); 280 tsin6.sin6_len = sizeof(struct sockaddr_in6); 281 tsin6.sin6_family = AF_INET6; 282 tsin6.sin6_addr = taddr6; 283 284 rt = rtpurelookup((struct sockaddr *)&tsin6); 285 rtifp = rt ? rt->rt_ifp : NULL; 286 if (rtifp && rtifp->if_bridge) 287 rtifp = rtifp->if_bridge; 288 289 if (rt != NULL && 290 (cmpifp != rtifp || 291 (cmpifp == rtifp && (m->m_flags & M_MCAST) == 0)) 292 ) { 293 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(cmpifp, 294 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 295 nd6log((LOG_INFO, 296 "nd6_ns_input: nd6 proxy %s(%s)<-%s ifa %p\n", 297 if_name(cmpifp), if_name(ifp), 298 if_name(rtifp), ifa)); 299 if (ifa) { 300 proxy = 1; 301 /* 302 * Manual link address on same interface 303 * w/announce flag will proxy-arp using 304 * target mac, else our mac is used. 305 */ 306 if (cmpifp == rtifp && 307 (rt->rt_flags & RTF_ANNOUNCE) && 308 rt->rt_gateway->sa_family == AF_LINK) { 309 proxydl = SDL(rt->rt_gateway); 310 } 311 } 312 } 313 if (rt != NULL) 314 --rt->rt_refcnt; 315 } 316 if (ifa == NULL) { 317 /* 318 * We've got an NS packet, and we don't have that adddress 319 * assigned for us. We MUST silently ignore it. 320 * See RFC2461 7.2.3. 321 */ 322 goto freeit; 323 } 324 myaddr6 = *IFA_IN6(ifa); 325 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 326 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 327 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 328 goto freeit; 329 330 if (lladdr && ((cmpifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 331 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 332 "(if %d, NS packet %d)\n", 333 ip6_sprintf(&taddr6), cmpifp->if_addrlen, lladdrlen - 2)); 334 goto bad; 335 } 336 337 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 338 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 339 ip6_sprintf(&saddr6))); 340 goto freeit; 341 } 342 343 /* 344 * We have neighbor solicitation packet, with target address equals to 345 * one of my tentative address. 346 * 347 * src addr how to process? 348 * --- --- 349 * multicast of course, invalid (rejected in ip6_input) 350 * unicast somebody is doing address resolution -> ignore 351 * unspec dup address detection 352 * 353 * The processing is defined in RFC 2462. 354 */ 355 if (tentative) { 356 /* 357 * If source address is unspecified address, it is for 358 * duplicated address detection. 359 * 360 * If not, the packet is for addess resolution; 361 * silently ignore it. 362 */ 363 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 364 nd6_dad_ns_input(ifa); 365 366 goto freeit; 367 } 368 369 /* 370 * If the source address is unspecified address, entries must not 371 * be created or updated. 372 * It looks that sender is performing DAD. Output NA toward 373 * all-node multicast address, to tell the sender that I'm using 374 * the address. 375 * S bit ("solicited") must be zero. 376 */ 377 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 378 saddr6 = kin6addr_linklocal_allnodes; 379 saddr6.s6_addr16[1] = htons(cmpifp->if_index); 380 nd6_na_output(cmpifp, &saddr6, &taddr6, 381 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 382 (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0), 383 tlladdr, (struct sockaddr *)proxydl); 384 goto freeit; 385 } 386 387 nd6_cache_lladdr(cmpifp, &saddr6, lladdr, lladdrlen, 388 ND_NEIGHBOR_SOLICIT, 0); 389 390 nd6_na_output(ifp, &saddr6, &taddr6, 391 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 392 (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0) | ND_NA_FLAG_SOLICITED, 393 tlladdr, (struct sockaddr *)proxydl); 394 freeit: 395 m_freem(m); 396 return; 397 398 bad: 399 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", ip6_sprintf(&saddr6))); 400 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", ip6_sprintf(&daddr6))); 401 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", ip6_sprintf(&taddr6))); 402 icmp6stat.icp6s_badns++; 403 m_freem(m); 404 } 405 406 /* 407 * Output an Neighbor Solicitation Message. Caller specifies: 408 * - ICMP6 header source IP6 address 409 * - ND6 header target IP6 address 410 * - ND6 header source datalink address 411 * 412 * Based on RFC 2461 413 * Based on RFC 2462 (duplicated address detection) 414 */ 415 void 416 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6, 417 const struct in6_addr *taddr6, 418 struct llinfo_nd6 *ln, /* for source address determination */ 419 int dad) /* duplicated address detection */ 420 { 421 struct mbuf *m; 422 struct ip6_hdr *ip6; 423 struct nd_neighbor_solicit *nd_ns; 424 struct in6_ifaddr *ia = NULL; 425 struct ip6_moptions im6o; 426 int icmp6len; 427 int maxlen; 428 caddr_t mac; 429 struct ifnet *outif = NULL; 430 431 if (IN6_IS_ADDR_MULTICAST(taddr6)) 432 return; 433 434 /* estimate the size of message */ 435 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 436 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 437 if (max_linkhdr + maxlen >= MCLBYTES) { 438 #ifdef DIAGNOSTIC 439 kprintf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES " 440 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES); 441 #endif 442 return; 443 } 444 445 m = m_getb(max_linkhdr + maxlen, M_NOWAIT, MT_DATA, M_PKTHDR); 446 if (m == NULL) 447 return; 448 449 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 450 m->m_flags |= M_MCAST; 451 im6o.im6o_multicast_ifp = ifp; 452 im6o.im6o_multicast_hlim = 255; 453 im6o.im6o_multicast_loop = 0; 454 } 455 456 icmp6len = sizeof(*nd_ns); 457 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 458 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 459 460 /* fill neighbor solicitation packet */ 461 ip6 = mtod(m, struct ip6_hdr *); 462 ip6->ip6_flow = 0; 463 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 464 ip6->ip6_vfc |= IPV6_VERSION; 465 /* ip6->ip6_plen will be set later */ 466 ip6->ip6_nxt = IPPROTO_ICMPV6; 467 ip6->ip6_hlim = 255; 468 if (daddr6) 469 ip6->ip6_dst = *daddr6; 470 else { 471 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 472 ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index); 473 ip6->ip6_dst.s6_addr32[1] = 0; 474 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 475 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 476 ip6->ip6_dst.s6_addr8[12] = 0xff; 477 } 478 if (!dad) { 479 /* 480 * RFC2461 7.2.2: 481 * "If the source address of the packet prompting the 482 * solicitation is the same as one of the addresses assigned 483 * to the outgoing interface, that address SHOULD be placed 484 * in the IP Source Address of the outgoing solicitation. 485 * Otherwise, any one of the addresses assigned to the 486 * interface should be used." 487 * 488 * We use the source address for the prompting packet 489 * (saddr6), if: 490 * - saddr6 is given from the caller (by giving "ln"), and 491 * - saddr6 belongs to the outgoing interface. 492 * Otherwise, we perform a scope-wise match. 493 */ 494 struct ip6_hdr *hip6; /* hold ip6 */ 495 struct in6_addr *saddr6; 496 497 if (ln && ln->ln_hold) { 498 hip6 = mtod(ln->ln_hold, struct ip6_hdr *); 499 /* XXX pullup? */ 500 if (sizeof(*hip6) < ln->ln_hold->m_len) 501 saddr6 = &hip6->ip6_src; 502 else 503 saddr6 = NULL; 504 } else 505 saddr6 = NULL; 506 if (saddr6 && in6ifa_ifpwithaddr(ifp, saddr6)) 507 bcopy(saddr6, &ip6->ip6_src, sizeof(*saddr6)); 508 else { 509 ia = in6_ifawithifp(ifp, &ip6->ip6_dst); 510 if (ia == NULL) { 511 m_freem(m); 512 return; 513 } 514 ip6->ip6_src = ia->ia_addr.sin6_addr; 515 } 516 } else { 517 /* 518 * Source address for DAD packet must always be IPv6 519 * unspecified address. (0::0) 520 */ 521 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 522 } 523 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 524 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 525 nd_ns->nd_ns_code = 0; 526 nd_ns->nd_ns_reserved = 0; 527 nd_ns->nd_ns_target = *taddr6; 528 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 529 530 /* 531 * Add source link-layer address option. 532 * 533 * spec implementation 534 * --- --- 535 * DAD packet MUST NOT do not add the option 536 * there's no link layer address: 537 * impossible do not add the option 538 * there's link layer address: 539 * Multicast NS MUST add one add the option 540 * Unicast NS SHOULD add one add the option 541 */ 542 if (!dad && (mac = nd6_ifptomac(ifp))) { 543 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 544 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 545 /* 8 byte alignments... */ 546 optlen = (optlen + 7) & ~7; 547 548 m->m_pkthdr.len += optlen; 549 m->m_len += optlen; 550 icmp6len += optlen; 551 bzero((caddr_t)nd_opt, optlen); 552 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 553 nd_opt->nd_opt_len = optlen >> 3; 554 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 555 } 556 557 ip6->ip6_plen = htons((u_short)icmp6len); 558 nd_ns->nd_ns_cksum = 0; 559 nd_ns->nd_ns_cksum = 560 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 561 562 ip6_output(m, NULL, NULL, dad ? IPV6_DADOUTPUT : 0, &im6o, &outif, NULL); 563 if (outif) { 564 icmp6_ifstat_inc(outif, ifs6_out_msg); 565 icmp6_ifstat_inc(outif, ifs6_out_neighborsolicit); 566 } 567 icmp6stat.icp6s_outhist[ND_NEIGHBOR_SOLICIT]++; 568 } 569 570 /* 571 * Neighbor advertisement input handling. 572 * 573 * Based on RFC 2461 574 * Based on RFC 2462 (duplicated address detection) 575 * 576 * the following items are not implemented yet: 577 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 578 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 579 */ 580 void 581 nd6_na_input(struct mbuf *m, int off, int icmp6len) 582 { 583 struct ifnet *ifp = m->m_pkthdr.rcvif; 584 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 585 struct nd_neighbor_advert *nd_na; 586 struct in6_addr saddr6 = ip6->ip6_src; 587 struct in6_addr daddr6 = ip6->ip6_dst; 588 struct in6_addr taddr6; 589 int flags; 590 int is_router; 591 int is_solicited; 592 int is_override; 593 char *lladdr = NULL; 594 int lladdrlen = 0; 595 struct ifaddr *ifa; 596 struct llinfo_nd6 *ln; 597 struct rtentry *rt; 598 struct sockaddr_dl *sdl; 599 union nd_opts ndopts; 600 601 if (ip6->ip6_hlim != 255) { 602 nd6log((LOG_ERR, 603 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 604 ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src), 605 ip6_sprintf(&ip6->ip6_dst), if_name(ifp))); 606 goto bad; 607 } 608 609 #ifndef PULLDOWN_TEST 610 IP6_EXTHDR_CHECK(m, off, icmp6len,); 611 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 612 #else 613 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 614 if (nd_na == NULL) { 615 icmp6stat.icp6s_tooshort++; 616 return; 617 } 618 #endif 619 taddr6 = nd_na->nd_na_target; 620 flags = nd_na->nd_na_flags_reserved; 621 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 622 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 623 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 624 625 if (IN6_IS_SCOPE_LINKLOCAL(&taddr6)) 626 taddr6.s6_addr16[1] = htons(ifp->if_index); 627 628 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 629 nd6log((LOG_ERR, 630 "nd6_na_input: invalid target address %s\n", 631 ip6_sprintf(&taddr6))); 632 goto bad; 633 } 634 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 635 if (is_solicited) { 636 nd6log((LOG_ERR, 637 "nd6_na_input: a solicited adv is multicasted\n")); 638 goto bad; 639 } 640 641 icmp6len -= sizeof(*nd_na); 642 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 643 if (nd6_options(&ndopts) < 0) { 644 nd6log((LOG_INFO, 645 "nd6_na_input: invalid ND option, ignored\n")); 646 /* nd6_options have incremented stats */ 647 goto freeit; 648 } 649 650 if (ndopts.nd_opts_tgt_lladdr) { 651 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 652 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 653 } 654 655 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 656 657 /* 658 * Target address matches one of my interface address. 659 * 660 * If my address is tentative, this means that there's somebody 661 * already using the same address as mine. This indicates DAD failure. 662 * This is defined in RFC 2462. 663 * 664 * Otherwise, process as defined in RFC 2461. 665 */ 666 if (ifa 667 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 668 nd6_dad_na_input(ifa); 669 goto freeit; 670 } 671 672 /* Just for safety, maybe unnecessary. */ 673 if (ifa) { 674 log(LOG_ERR, 675 "nd6_na_input: duplicate IP6 address %s\n", 676 ip6_sprintf(&taddr6)); 677 goto freeit; 678 } 679 680 if (!nd6_onlink_ns_rfc4861) { 681 /* 682 * Make sure the source address is from a neighbor's address. 683 */ 684 if (in6ifa_ifplocaladdr(ifp, &saddr6) == NULL) { 685 nd6log((LOG_INFO, "nd6_na_input: " 686 "NA packet from non-neighbor\n")); 687 goto bad; 688 } 689 } 690 691 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 692 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 693 "(if %d, NA packet %d)\n", ip6_sprintf(&taddr6), 694 ifp->if_addrlen, lladdrlen - 2)); 695 goto bad; 696 } 697 698 /* 699 * If no neighbor cache entry is found, NA SHOULD silently be discarded. 700 */ 701 rt = nd6_lookup(&taddr6, 0, ifp); 702 if ((rt == NULL) || 703 ((ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) || 704 ((sdl = SDL(rt->rt_gateway)) == NULL)) 705 goto freeit; 706 707 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 708 /* 709 * If the link-layer has address, and no lladdr option came, 710 * discard the packet. 711 */ 712 if (ifp->if_addrlen && !lladdr) 713 goto freeit; 714 715 /* 716 * Record link-layer address, and update the state. 717 */ 718 sdl->sdl_alen = ifp->if_addrlen; 719 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); 720 if (is_solicited) { 721 ln->ln_state = ND6_LLINFO_REACHABLE; 722 ln->ln_byhint = 0; 723 if (ln->ln_expire) { 724 ln->ln_expire = time_uptime + 725 ND_IFINFO(rt->rt_ifp)->reachable; 726 } 727 } else { 728 ln->ln_state = ND6_LLINFO_STALE; 729 ln->ln_expire = time_uptime + nd6_gctimer; 730 } 731 if ((ln->ln_router = is_router) != 0) { 732 /* 733 * This means a router's state has changed from 734 * non-reachable to probably reachable, and might 735 * affect the status of associated prefixes.. 736 */ 737 pfxlist_onlink_check(); 738 } 739 } else { 740 int llchange; 741 742 /* 743 * Check if the link-layer address has changed or not. 744 */ 745 if (!lladdr) 746 llchange = 0; 747 else { 748 if (sdl->sdl_alen) { 749 if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen)) 750 llchange = 1; 751 else 752 llchange = 0; 753 } else 754 llchange = 1; 755 } 756 757 /* 758 * This is VERY complex. Look at it with care. 759 * 760 * override solicit lladdr llchange action 761 * (L: record lladdr) 762 * 763 * 0 0 n -- (2c) 764 * 0 0 y n (2b) L 765 * 0 0 y y (1) REACHABLE->STALE 766 * 0 1 n -- (2c) *->REACHABLE 767 * 0 1 y n (2b) L *->REACHABLE 768 * 0 1 y y (1) REACHABLE->STALE 769 * 1 0 n -- (2a) 770 * 1 0 y n (2a) L 771 * 1 0 y y (2a) L *->STALE 772 * 1 1 n -- (2a) *->REACHABLE 773 * 1 1 y n (2a) L *->REACHABLE 774 * 1 1 y y (2a) L *->REACHABLE 775 */ 776 if (!is_override && (lladdr && llchange)) { /* (1) */ 777 /* 778 * If state is REACHABLE, make it STALE. 779 * no other updates should be done. 780 */ 781 if (ln->ln_state == ND6_LLINFO_REACHABLE) { 782 ln->ln_state = ND6_LLINFO_STALE; 783 ln->ln_expire = time_uptime + nd6_gctimer; 784 } 785 goto freeit; 786 } else if (is_override /* (2a) */ 787 || (!is_override && (lladdr && !llchange)) /* (2b) */ 788 || !lladdr) { /* (2c) */ 789 /* 790 * Update link-local address, if any. 791 */ 792 if (lladdr) { 793 sdl->sdl_alen = ifp->if_addrlen; 794 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); 795 } 796 797 /* 798 * If solicited, make the state REACHABLE. 799 * If not solicited and the link-layer address was 800 * changed, make it STALE. 801 */ 802 if (is_solicited) { 803 ln->ln_state = ND6_LLINFO_REACHABLE; 804 ln->ln_byhint = 0; 805 if (ln->ln_expire) { 806 ln->ln_expire = time_uptime + 807 ND_IFINFO(ifp)->reachable; 808 } 809 } else { 810 if (lladdr && llchange) { 811 ln->ln_state = ND6_LLINFO_STALE; 812 ln->ln_expire = time_uptime + nd6_gctimer; 813 } 814 } 815 } 816 817 if (ln->ln_router && !is_router) { 818 /* 819 * The peer dropped the router flag. 820 * Remove the sender from the Default Router List and 821 * update the Destination Cache entries. 822 */ 823 struct nd_defrouter *dr; 824 struct in6_addr *in6; 825 826 in6 = &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr; 827 828 /* 829 * Lock to protect the default router list. 830 * XXX: this might be unnecessary, since this function 831 * is only called under the network software interrupt 832 * context. However, we keep it just for safety. 833 */ 834 mtx_lock(&nd6_mtx); 835 dr = defrouter_lookup(in6, rt->rt_ifp); 836 if (dr) 837 defrtrlist_del(dr); 838 mtx_unlock(&nd6_mtx); 839 840 if (dr == NULL && !ip6_forwarding && ip6_accept_rtadv) { 841 /* 842 * Even if the neighbor is not in the default 843 * router list, the neighbor may be used 844 * as a next hop for some destinations 845 * (e.g. redirect case). So we must 846 * call rt6_flush explicitly. 847 */ 848 rt6_flush(&ip6->ip6_src, rt->rt_ifp); 849 } 850 } 851 ln->ln_router = is_router; 852 } 853 rt->rt_flags &= ~RTF_REJECT; 854 ln->ln_asked = 0; 855 if (ln->ln_hold) { 856 /* 857 * we assume ifp is not a loopback here, so just set the 2nd 858 * argument as the 1st one. 859 */ 860 nd6_output(ifp, ifp, ln->ln_hold, 861 (struct sockaddr_in6 *)rt_key(rt), rt); 862 ln->ln_hold = NULL; 863 } 864 865 freeit: 866 m_freem(m); 867 return; 868 869 bad: 870 icmp6stat.icp6s_badna++; 871 m_freem(m); 872 } 873 874 /* 875 * Neighbor advertisement output handling. 876 * 877 * Based on RFC 2461 878 * 879 * the following items are not implemented yet: 880 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 881 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 882 */ 883 void 884 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6, 885 const struct in6_addr *taddr6, u_long flags, 886 int tlladdr, /* 1 if include target link-layer address */ 887 struct sockaddr *sdl0) /* sockaddr_dl (= proxy NA) or NULL */ 888 { 889 struct mbuf *m; 890 struct ip6_hdr *ip6; 891 struct nd_neighbor_advert *nd_na; 892 struct in6_ifaddr *ia = NULL; 893 struct ip6_moptions im6o; 894 int icmp6len; 895 int maxlen; 896 caddr_t mac; 897 struct ifnet *outif = NULL; 898 899 /* estimate the size of message */ 900 maxlen = sizeof(*ip6) + sizeof(*nd_na); 901 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 902 if (max_linkhdr + maxlen >= MCLBYTES) { 903 #ifdef DIAGNOSTIC 904 kprintf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES " 905 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES); 906 #endif 907 return; 908 } 909 910 m = m_getb(max_linkhdr + maxlen, M_NOWAIT, MT_DATA, M_PKTHDR); 911 if (m == NULL) 912 return; 913 914 if (IN6_IS_ADDR_MULTICAST(daddr6)) { 915 m->m_flags |= M_MCAST; 916 im6o.im6o_multicast_ifp = ifp; 917 im6o.im6o_multicast_hlim = 255; 918 im6o.im6o_multicast_loop = 0; 919 } 920 921 icmp6len = sizeof(*nd_na); 922 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 923 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 924 925 /* fill neighbor advertisement packet */ 926 ip6 = mtod(m, struct ip6_hdr *); 927 ip6->ip6_flow = 0; 928 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 929 ip6->ip6_vfc |= IPV6_VERSION; 930 ip6->ip6_nxt = IPPROTO_ICMPV6; 931 ip6->ip6_hlim = 255; 932 if (IN6_IS_ADDR_UNSPECIFIED(daddr6)) { 933 /* reply to DAD */ 934 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 935 ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index); 936 ip6->ip6_dst.s6_addr32[1] = 0; 937 ip6->ip6_dst.s6_addr32[2] = 0; 938 ip6->ip6_dst.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 939 flags &= ~ND_NA_FLAG_SOLICITED; 940 } else 941 ip6->ip6_dst = *daddr6; 942 943 /* 944 * Select a source whose scope is the same as that of the dest. 945 */ 946 ia = in6_ifawithifp(ifp, &ip6->ip6_dst); 947 if (ia == NULL) { 948 m_freem(m); 949 return; 950 } 951 ip6->ip6_src = ia->ia_addr.sin6_addr; 952 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 953 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 954 nd_na->nd_na_code = 0; 955 nd_na->nd_na_target = *taddr6; 956 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 957 958 /* 959 * "tlladdr" indicates NS's condition for adding tlladdr or not. 960 * see nd6_ns_input() for details. 961 * Basically, if NS packet is sent to unicast/anycast addr, 962 * target lladdr option SHOULD NOT be included. 963 */ 964 mac = NULL; 965 if (tlladdr) { 966 /* 967 * sdl0 != NULL indicates proxy NA. If we do proxy, use 968 * lladdr in sdl0. If we are not proxying (sending NA for 969 * my address) use lladdr configured for the interface. 970 */ 971 if (sdl0 == NULL) { 972 #ifdef CARP 973 if (ifp->if_carp) 974 mac = carp_macmatch6(ifp->if_carp, m, taddr6); 975 if (mac == NULL) 976 mac = nd6_ifptomac(ifp); 977 #else 978 mac = nd6_ifptomac(ifp); 979 #endif 980 } else if (sdl0->sa_family == AF_LINK) { 981 struct sockaddr_dl *sdl; 982 sdl = (struct sockaddr_dl *)sdl0; 983 if (sdl->sdl_alen == ifp->if_addrlen) 984 mac = LLADDR(sdl); 985 } 986 } 987 if (mac != NULL) { 988 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 989 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 990 991 /* roundup to 8 bytes alignment! */ 992 optlen = (optlen + 7) & ~7; 993 994 m->m_pkthdr.len += optlen; 995 m->m_len += optlen; 996 icmp6len += optlen; 997 bzero((caddr_t)nd_opt, optlen); 998 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 999 nd_opt->nd_opt_len = optlen >> 3; 1000 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1001 } else 1002 flags &= ~ND_NA_FLAG_OVERRIDE; 1003 1004 ip6->ip6_plen = htons((u_short)icmp6len); 1005 nd_na->nd_na_flags_reserved = flags; 1006 nd_na->nd_na_cksum = 0; 1007 nd_na->nd_na_cksum = 1008 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1009 1010 ip6_output(m, NULL, NULL, 0, &im6o, &outif, NULL); 1011 if (outif) { 1012 icmp6_ifstat_inc(outif, ifs6_out_msg); 1013 icmp6_ifstat_inc(outif, ifs6_out_neighboradvert); 1014 } 1015 icmp6stat.icp6s_outhist[ND_NEIGHBOR_ADVERT]++; 1016 } 1017 1018 caddr_t 1019 nd6_ifptomac(struct ifnet *ifp) 1020 { 1021 switch (ifp->if_type) { 1022 case IFT_ETHER: 1023 case IFT_IEEE1394: 1024 #ifdef IFT_L2VLAN 1025 case IFT_L2VLAN: 1026 #endif 1027 #ifdef IFT_IEEE80211 1028 case IFT_IEEE80211: 1029 #endif 1030 #ifdef IFT_CARP 1031 case IFT_CARP: 1032 #endif 1033 return ((caddr_t)(ifp + 1)); 1034 default: 1035 return NULL; 1036 } 1037 } 1038 1039 struct netmsg_dad { 1040 struct netmsg_base base; 1041 struct dadq *dadq; 1042 }; 1043 1044 struct dadq { 1045 TAILQ_ENTRY(dadq) dad_list; 1046 struct ifaddr *dad_ifa; 1047 int dad_count; /* max NS to send */ 1048 int dad_ns_tcount; /* # of trials to send NS */ 1049 int dad_ns_ocount; /* NS sent so far */ 1050 int dad_ns_icount; 1051 int dad_na_icount; 1052 struct callout dad_timer_ch; 1053 struct netmsg_dad dad_nmsg; 1054 }; 1055 TAILQ_HEAD(dadq_head, dadq); 1056 1057 static struct dadq_head dadq = TAILQ_HEAD_INITIALIZER(dadq); 1058 1059 static struct dadq * 1060 nd6_dad_find(struct ifaddr *ifa) 1061 { 1062 struct dadq *dp; 1063 1064 ASSERT_IN_NETISR(0); 1065 1066 TAILQ_FOREACH(dp, &dadq, dad_list) { 1067 if (dp->dad_ifa == ifa) 1068 return dp; 1069 } 1070 return NULL; 1071 } 1072 1073 static void 1074 nd6_dad_starttimer(struct dadq *dp, int ticks) 1075 { 1076 ASSERT_IN_NETISR(0); 1077 callout_reset(&dp->dad_timer_ch, ticks, nd6_dad_timer, dp); 1078 } 1079 1080 static void 1081 nd6_dad_stoptimer(struct dadq *dp) 1082 { 1083 ASSERT_IN_NETISR(0); 1084 callout_stop(&dp->dad_timer_ch); 1085 } 1086 1087 /* 1088 * Start Duplicated Address Detection (DAD) for specified interface address. 1089 */ 1090 void 1091 nd6_dad_start(struct ifaddr *ifa, 1092 int *tick) /* minimum delay ticks for IFF_UP event */ 1093 { 1094 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1095 struct dadq *dp; 1096 1097 ASSERT_IN_NETISR(0); 1098 1099 /* 1100 * If we don't need DAD, don't do it. 1101 * There are several cases: 1102 * - DAD is disabled (ip6_dad_count == 0) 1103 * - the interface address is anycast 1104 */ 1105 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1106 log(LOG_DEBUG, 1107 "nd6_dad_start: called with non-tentative address " 1108 "%s(%s)\n", 1109 ip6_sprintf(&ia->ia_addr.sin6_addr), 1110 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1111 return; 1112 } 1113 if (ia->ia6_flags & IN6_IFF_ANYCAST) { 1114 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1115 return; 1116 } 1117 if (!ip6_dad_count) { 1118 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1119 return; 1120 } 1121 if (!ifa->ifa_ifp) 1122 panic("nd6_dad_start: ifa->ifa_ifp == NULL"); 1123 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1124 return; 1125 if (nd6_dad_find(ifa) != NULL) { 1126 /* DAD already in progress */ 1127 return; 1128 } 1129 1130 dp = nd6_dad_create(ifa); 1131 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1132 ip6_sprintf(&ia->ia_addr.sin6_addr))); 1133 1134 /* 1135 * Send NS packet for DAD, dp->dad_count times. 1136 * Note that we must delay the first transmission, if this is the 1137 * first packet to be sent from the interface after interface 1138 * (re)initialization. 1139 */ 1140 if (tick == NULL) { 1141 nd6_dad_ns_output(dp); 1142 nd6_dad_starttimer(dp, 1143 ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1144 } else { 1145 int ntick; 1146 1147 if (*tick == 0) 1148 ntick = krandom() % (MAX_RTR_SOLICITATION_DELAY * hz); 1149 else 1150 ntick = *tick + krandom() % (hz / 2); 1151 *tick = ntick; 1152 nd6_dad_starttimer(dp, ntick); 1153 } 1154 } 1155 1156 /* 1157 * Terminate DAD unconditionally. Used for address removals. 1158 */ 1159 void 1160 nd6_dad_stop(struct ifaddr *ifa) 1161 { 1162 struct dadq *dp; 1163 1164 ASSERT_IN_NETISR(0); 1165 1166 dp = nd6_dad_find(ifa); 1167 if (!dp) { 1168 /* DAD wasn't started yet */ 1169 return; 1170 } 1171 nd6_dad_destroy(dp); 1172 } 1173 1174 static struct dadq * 1175 nd6_dad_create(struct ifaddr *ifa) 1176 { 1177 struct netmsg_dad *dm; 1178 struct dadq *dp; 1179 1180 ASSERT_IN_NETISR(0); 1181 1182 dp = kmalloc(sizeof(*dp), M_IP6NDP, M_INTWAIT | M_ZERO); 1183 callout_init_mp(&dp->dad_timer_ch); 1184 1185 dm = &dp->dad_nmsg; 1186 netmsg_init(&dm->base, NULL, &netisr_adone_rport, 1187 MSGF_DROPABLE | MSGF_PRIORITY, nd6_dad_timer_handler); 1188 dm->dadq = dp; 1189 1190 dp->dad_ifa = ifa; 1191 IFAREF(ifa); /* just for safety */ 1192 1193 /* Send NS packet for DAD, ip6_dad_count times. */ 1194 dp->dad_count = ip6_dad_count; 1195 1196 TAILQ_INSERT_TAIL(&dadq, dp, dad_list); 1197 1198 return dp; 1199 } 1200 1201 static void 1202 nd6_dad_destroy(struct dadq *dp) 1203 { 1204 struct lwkt_msg *lmsg = &dp->dad_nmsg.base.lmsg; 1205 1206 ASSERT_IN_NETISR(0); 1207 1208 TAILQ_REMOVE(&dadq, dp, dad_list); 1209 1210 nd6_dad_stoptimer(dp); 1211 1212 crit_enter(); 1213 if ((lmsg->ms_flags & MSGF_DONE) == 0) 1214 lwkt_dropmsg(lmsg); 1215 crit_exit(); 1216 1217 IFAFREE(dp->dad_ifa); 1218 kfree(dp, M_IP6NDP); 1219 } 1220 1221 static void 1222 nd6_dad_timer(void *xdp) 1223 { 1224 struct dadq *dp = xdp; 1225 struct lwkt_msg *lmsg = &dp->dad_nmsg.base.lmsg; 1226 1227 KASSERT(mycpuid == 0, ("dad timer not on cpu0")); 1228 1229 crit_enter(); 1230 if (lmsg->ms_flags & MSGF_DONE) 1231 lwkt_sendmsg_oncpu(netisr_cpuport(0), lmsg); 1232 crit_exit(); 1233 } 1234 1235 static void 1236 nd6_dad_timer_handler(netmsg_t msg) 1237 { 1238 struct netmsg_dad *dm = (struct netmsg_dad *)msg; 1239 struct dadq *dp = dm->dadq; 1240 struct ifaddr *ifa = dp->dad_ifa; 1241 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1242 1243 ASSERT_IN_NETISR(0); 1244 1245 /* Reply ASAP */ 1246 crit_enter(); 1247 lwkt_replymsg(&dm->base.lmsg, 0); 1248 crit_exit(); 1249 1250 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1251 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1252 "%s(%s)\n", 1253 ip6_sprintf(&ia->ia_addr.sin6_addr), 1254 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1255 goto destroy; 1256 } 1257 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1258 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1259 "%s(%s)\n", 1260 ip6_sprintf(&ia->ia_addr.sin6_addr), 1261 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1262 goto destroy; 1263 } 1264 1265 /* Timed out with IFF_{RUNNING,UP} check */ 1266 if (dp->dad_ns_tcount > dad_maxtry) { 1267 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n", 1268 if_name(ifa->ifa_ifp))); 1269 goto destroy; 1270 } 1271 1272 /* Need more checks? */ 1273 if (dp->dad_ns_ocount < dp->dad_count) { 1274 /* 1275 * We have more NS to go. Send NS packet for DAD. 1276 */ 1277 nd6_dad_ns_output(dp); 1278 nd6_dad_starttimer(dp, 1279 ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1280 } else { 1281 /* 1282 * We have transmitted sufficient number of DAD packets. 1283 * See what we've got. 1284 */ 1285 int duplicate; 1286 1287 duplicate = 0; 1288 1289 if (dp->dad_na_icount) { 1290 /* 1291 * the check is in nd6_dad_na_input(), 1292 * but just in case 1293 */ 1294 duplicate++; 1295 } 1296 1297 if (dp->dad_ns_icount) { 1298 #if 0 /* heuristics */ 1299 /* 1300 * if 1301 * - we have sent many(?) DAD NS, and 1302 * - the number of NS we sent equals to the 1303 * number of NS we've got, and 1304 * - we've got no NA 1305 * we may have a faulty network card/driver which 1306 * loops back multicasts to myself. 1307 */ 1308 if (3 < dp->dad_count 1309 && dp->dad_ns_icount == dp->dad_count 1310 && dp->dad_na_icount == 0) { 1311 log(LOG_INFO, "DAD questionable for %s(%s): " 1312 "network card loops back multicast?\n", 1313 ip6_sprintf(&ia->ia_addr.sin6_addr), 1314 if_name(ifa->ifa_ifp)); 1315 /* XXX consider it a duplicate or not? */ 1316 /* duplicate++; */ 1317 } else { 1318 /* We've seen NS, means DAD has failed. */ 1319 duplicate++; 1320 } 1321 #else 1322 /* We've seen NS, means DAD has failed. */ 1323 duplicate++; 1324 #endif 1325 } 1326 1327 if (duplicate) { 1328 /* dp will be freed in nd6_dad_duplicated() */ 1329 dp = NULL; 1330 nd6_dad_duplicated(ifa); 1331 } else { 1332 /* 1333 * We are done with DAD. No NA came, no NS came. 1334 * duplicated address found. 1335 */ 1336 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1337 nd6log((LOG_DEBUG, 1338 "%s: DAD complete for %s - no duplicates found\n", 1339 if_name(ifa->ifa_ifp), 1340 ip6_sprintf(&ia->ia_addr.sin6_addr))); 1341 goto destroy; 1342 } 1343 } 1344 return; 1345 destroy: 1346 nd6_dad_destroy(dp); 1347 } 1348 1349 static void 1350 nd6_dad_duplicated(struct ifaddr *ifa) 1351 { 1352 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1353 struct dadq *dp; 1354 1355 ASSERT_IN_NETISR(0); 1356 1357 dp = nd6_dad_find(ifa); 1358 if (dp == NULL) { 1359 log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n"); 1360 return; 1361 } 1362 1363 /* 1364 * We are done with DAD, with duplicated address found. (failure) 1365 */ 1366 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1367 "NS in/out=%d/%d, NA in=%d\n", 1368 if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr), 1369 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount); 1370 1371 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1372 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1373 1374 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1375 if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr)); 1376 log(LOG_ERR, "%s: manual intervention required\n", 1377 if_name(ifa->ifa_ifp)); 1378 1379 nd6_dad_destroy(dp); 1380 } 1381 1382 static void 1383 nd6_dad_ns_output(struct dadq *dp) 1384 { 1385 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1386 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1387 1388 ASSERT_IN_NETISR(0); 1389 1390 dp->dad_ns_tcount++; 1391 if (!(ifp->if_flags & IFF_UP)) { 1392 #if 0 1393 kprintf("%s: interface down?\n", if_name(ifp)); 1394 #endif 1395 return; 1396 } 1397 if (!(ifp->if_flags & IFF_RUNNING)) { 1398 #if 0 1399 kprintf("%s: interface not running?\n", if_name(ifp)); 1400 #endif 1401 return; 1402 } 1403 1404 dp->dad_ns_ocount++; 1405 nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1); 1406 } 1407 1408 static void 1409 nd6_dad_ns_input(struct ifaddr *ifa) 1410 { 1411 struct in6_ifaddr *ia; 1412 const struct in6_addr *taddr6; 1413 struct dadq *dp; 1414 int duplicate; 1415 1416 ASSERT_IN_NETISR(0); 1417 1418 if (!ifa) 1419 panic("ifa == NULL in nd6_dad_ns_input"); 1420 1421 ia = (struct in6_ifaddr *)ifa; 1422 taddr6 = &ia->ia_addr.sin6_addr; 1423 duplicate = 0; 1424 dp = nd6_dad_find(ifa); 1425 1426 /* Quickhack - completely ignore DAD NS packets */ 1427 if (dad_ignore_ns) { 1428 nd6log((LOG_INFO, 1429 "nd6_dad_ns_input: ignoring DAD NS packet for " 1430 "address %s(%s)\n", ip6_sprintf(taddr6), 1431 if_name(ifa->ifa_ifp))); 1432 return; 1433 } 1434 1435 /* 1436 * if I'm yet to start DAD, someone else started using this address 1437 * first. I have a duplicate and you win. 1438 */ 1439 if (!dp || dp->dad_ns_ocount == 0) 1440 duplicate++; 1441 1442 /* XXX more checks for loopback situation - see nd6_dad_timer too */ 1443 1444 if (duplicate) { 1445 dp = NULL; /* will be freed in nd6_dad_duplicated() */ 1446 nd6_dad_duplicated(ifa); 1447 } else { 1448 /* 1449 * not sure if I got a duplicate. 1450 * increment ns count and see what happens. 1451 */ 1452 if (dp) 1453 dp->dad_ns_icount++; 1454 } 1455 } 1456 1457 static void 1458 nd6_dad_na_input(struct ifaddr *ifa) 1459 { 1460 struct dadq *dp; 1461 1462 ASSERT_IN_NETISR(0); 1463 1464 if (!ifa) 1465 panic("ifa == NULL in nd6_dad_na_input"); 1466 1467 dp = nd6_dad_find(ifa); 1468 if (dp) 1469 dp->dad_na_icount++; 1470 1471 /* remove the address. */ 1472 nd6_dad_duplicated(ifa); 1473 } 1474