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 || (m->m_flags & M_MCAST) == 0)) { 291 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(cmpifp, 292 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 293 nd6log((LOG_INFO, 294 "nd6_ns_input: nd6 proxy %s(%s)<-%s ifa %p\n", 295 if_name(cmpifp), if_name(ifp), 296 if_name(rtifp), ifa)); 297 if (ifa) { 298 proxy = 1; 299 /* 300 * Manual link address on same interface 301 * w/announce flag will proxy-arp using 302 * target mac, else our mac is used. 303 */ 304 if (cmpifp == rtifp && 305 (rt->rt_flags & RTF_ANNOUNCE) && 306 rt->rt_gateway->sa_family == AF_LINK) { 307 proxydl = SDL(rt->rt_gateway); 308 } 309 } 310 } 311 if (rt != NULL) 312 --rt->rt_refcnt; 313 } 314 if (ifa == NULL) { 315 /* 316 * We've got an NS packet, and we don't have that adddress 317 * assigned for us. We MUST silently ignore it. 318 * See RFC2461 7.2.3. 319 */ 320 goto freeit; 321 } 322 myaddr6 = *IFA_IN6(ifa); 323 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 324 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 325 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 326 goto freeit; 327 328 if (lladdr && ((cmpifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 329 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 330 "(if %d, NS packet %d)\n", 331 ip6_sprintf(&taddr6), cmpifp->if_addrlen, lladdrlen - 2)); 332 goto bad; 333 } 334 335 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 336 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 337 ip6_sprintf(&saddr6))); 338 goto freeit; 339 } 340 341 /* 342 * We have neighbor solicitation packet, with target address equals to 343 * one of my tentative address. 344 * 345 * src addr how to process? 346 * --- --- 347 * multicast of course, invalid (rejected in ip6_input) 348 * unicast somebody is doing address resolution -> ignore 349 * unspec dup address detection 350 * 351 * The processing is defined in RFC 2462. 352 */ 353 if (tentative) { 354 /* 355 * If source address is unspecified address, it is for 356 * duplicated address detection. 357 * 358 * If not, the packet is for addess resolution; 359 * silently ignore it. 360 */ 361 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 362 nd6_dad_ns_input(ifa); 363 364 goto freeit; 365 } 366 367 /* 368 * If the source address is unspecified address, entries must not 369 * be created or updated. 370 * It looks that sender is performing DAD. Output NA toward 371 * all-node multicast address, to tell the sender that I'm using 372 * the address. 373 * S bit ("solicited") must be zero. 374 */ 375 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 376 saddr6 = kin6addr_linklocal_allnodes; 377 saddr6.s6_addr16[1] = htons(cmpifp->if_index); 378 nd6_na_output(cmpifp, &saddr6, &taddr6, 379 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 380 (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0), 381 tlladdr, (struct sockaddr *)proxydl); 382 goto freeit; 383 } 384 385 nd6_cache_lladdr(cmpifp, &saddr6, lladdr, lladdrlen, 386 ND_NEIGHBOR_SOLICIT, 0); 387 388 nd6_na_output(ifp, &saddr6, &taddr6, 389 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 390 (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0) | 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, M_NOWAIT, 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 /* 478 * RFC2461 7.2.2: 479 * "If the source address of the packet prompting the 480 * solicitation is the same as one of the addresses assigned 481 * to the outgoing interface, that address SHOULD be placed 482 * in the IP Source Address of the outgoing solicitation. 483 * Otherwise, any one of the addresses assigned to the 484 * interface should be used." 485 * 486 * We use the source address for the prompting packet 487 * (saddr6), if: 488 * - saddr6 is given from the caller (by giving "ln"), and 489 * - saddr6 belongs to the outgoing interface. 490 * Otherwise, we perform a scope-wise match. 491 */ 492 struct ip6_hdr *hip6; /* hold ip6 */ 493 struct in6_addr *saddr6; 494 495 if (ln && ln->ln_hold) { 496 hip6 = mtod(ln->ln_hold, struct ip6_hdr *); 497 /* XXX pullup? */ 498 if (sizeof(*hip6) < ln->ln_hold->m_len) 499 saddr6 = &hip6->ip6_src; 500 else 501 saddr6 = NULL; 502 } else 503 saddr6 = NULL; 504 if (saddr6 && in6ifa_ifpwithaddr(ifp, saddr6)) 505 bcopy(saddr6, &ip6->ip6_src, sizeof(*saddr6)); 506 else { 507 ia = in6_ifawithifp(ifp, &ip6->ip6_dst); 508 if (ia == NULL) { 509 m_freem(m); 510 return; 511 } 512 ip6->ip6_src = ia->ia_addr.sin6_addr; 513 } 514 } else { 515 /* 516 * Source address for DAD packet must always be IPv6 517 * unspecified address. (0::0) 518 */ 519 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 520 } 521 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 522 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 523 nd_ns->nd_ns_code = 0; 524 nd_ns->nd_ns_reserved = 0; 525 nd_ns->nd_ns_target = *taddr6; 526 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 527 528 /* 529 * Add source link-layer address option. 530 * 531 * spec implementation 532 * --- --- 533 * DAD packet MUST NOT do not add the option 534 * there's no link layer address: 535 * impossible do not add the option 536 * there's link layer address: 537 * Multicast NS MUST add one add the option 538 * Unicast NS SHOULD add one add the option 539 */ 540 if (!dad && (mac = nd6_ifptomac(ifp))) { 541 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 542 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 543 /* 8 byte alignments... */ 544 optlen = (optlen + 7) & ~7; 545 546 m->m_pkthdr.len += optlen; 547 m->m_len += optlen; 548 icmp6len += optlen; 549 bzero((caddr_t)nd_opt, optlen); 550 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 551 nd_opt->nd_opt_len = optlen >> 3; 552 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 553 } 554 555 ip6->ip6_plen = htons((u_short)icmp6len); 556 nd_ns->nd_ns_cksum = 0; 557 nd_ns->nd_ns_cksum = 558 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 559 560 ip6_output(m, NULL, NULL, dad ? IPV6_DADOUTPUT : 0, &im6o, &outif, NULL); 561 if (outif) { 562 icmp6_ifstat_inc(outif, ifs6_out_msg); 563 icmp6_ifstat_inc(outif, ifs6_out_neighborsolicit); 564 } 565 icmp6stat.icp6s_outhist[ND_NEIGHBOR_SOLICIT]++; 566 } 567 568 /* 569 * Neighbor advertisement input handling. 570 * 571 * Based on RFC 2461 572 * Based on RFC 2462 (duplicated address detection) 573 * 574 * the following items are not implemented yet: 575 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 576 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 577 */ 578 void 579 nd6_na_input(struct mbuf *m, int off, int icmp6len) 580 { 581 struct ifnet *ifp = m->m_pkthdr.rcvif; 582 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 583 struct nd_neighbor_advert *nd_na; 584 struct in6_addr saddr6 = ip6->ip6_src; 585 struct in6_addr daddr6 = ip6->ip6_dst; 586 struct in6_addr taddr6; 587 int flags; 588 int is_router; 589 int is_solicited; 590 int is_override; 591 char *lladdr = NULL; 592 int lladdrlen = 0; 593 struct ifaddr *ifa; 594 struct llinfo_nd6 *ln; 595 struct rtentry *rt; 596 struct sockaddr_dl *sdl; 597 union nd_opts ndopts; 598 599 if (ip6->ip6_hlim != 255) { 600 nd6log((LOG_ERR, 601 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 602 ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src), 603 ip6_sprintf(&ip6->ip6_dst), if_name(ifp))); 604 goto bad; 605 } 606 607 #ifndef PULLDOWN_TEST 608 IP6_EXTHDR_CHECK(m, off, icmp6len,); 609 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 610 #else 611 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 612 if (nd_na == NULL) { 613 icmp6stat.icp6s_tooshort++; 614 return; 615 } 616 #endif 617 taddr6 = nd_na->nd_na_target; 618 flags = nd_na->nd_na_flags_reserved; 619 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 620 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 621 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 622 623 if (IN6_IS_SCOPE_LINKLOCAL(&taddr6)) 624 taddr6.s6_addr16[1] = htons(ifp->if_index); 625 626 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 627 nd6log((LOG_ERR, 628 "nd6_na_input: invalid target address %s\n", 629 ip6_sprintf(&taddr6))); 630 goto bad; 631 } 632 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 633 if (is_solicited) { 634 nd6log((LOG_ERR, 635 "nd6_na_input: a solicited adv is multicasted\n")); 636 goto bad; 637 } 638 639 icmp6len -= sizeof(*nd_na); 640 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 641 if (nd6_options(&ndopts) < 0) { 642 nd6log((LOG_INFO, 643 "nd6_na_input: invalid ND option, ignored\n")); 644 /* nd6_options have incremented stats */ 645 goto freeit; 646 } 647 648 if (ndopts.nd_opts_tgt_lladdr) { 649 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 650 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 651 } 652 653 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 654 655 /* 656 * Target address matches one of my interface address. 657 * 658 * If my address is tentative, this means that there's somebody 659 * already using the same address as mine. This indicates DAD failure. 660 * This is defined in RFC 2462. 661 * 662 * Otherwise, process as defined in RFC 2461. 663 */ 664 if (ifa 665 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 666 nd6_dad_na_input(ifa); 667 goto freeit; 668 } 669 670 /* Just for safety, maybe unnecessary. */ 671 if (ifa) { 672 log(LOG_ERR, 673 "nd6_na_input: duplicate IP6 address %s\n", 674 ip6_sprintf(&taddr6)); 675 goto freeit; 676 } 677 678 if (!nd6_onlink_ns_rfc4861) { 679 /* 680 * Make sure the source address is from a neighbor's address. 681 */ 682 if (in6ifa_ifplocaladdr(ifp, &saddr6) == NULL) { 683 nd6log((LOG_INFO, "nd6_na_input: " 684 "NA packet from non-neighbor\n")); 685 goto bad; 686 } 687 } 688 689 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 690 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 691 "(if %d, NA packet %d)\n", ip6_sprintf(&taddr6), 692 ifp->if_addrlen, lladdrlen - 2)); 693 goto bad; 694 } 695 696 /* 697 * If no neighbor cache entry is found, NA SHOULD silently be discarded. 698 */ 699 rt = nd6_lookup(&taddr6, 0, ifp); 700 if ((rt == NULL) || 701 ((ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) || 702 ((sdl = SDL(rt->rt_gateway)) == NULL)) 703 goto freeit; 704 705 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 706 /* 707 * If the link-layer has address, and no lladdr option came, 708 * discard the packet. 709 */ 710 if (ifp->if_addrlen && !lladdr) 711 goto freeit; 712 713 /* 714 * Record link-layer address, and update the state. 715 */ 716 sdl->sdl_alen = ifp->if_addrlen; 717 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); 718 if (is_solicited) { 719 ln->ln_state = ND6_LLINFO_REACHABLE; 720 ln->ln_byhint = 0; 721 if (ln->ln_expire) { 722 ln->ln_expire = time_uptime + 723 ND_IFINFO(rt->rt_ifp)->reachable; 724 } 725 } else { 726 ln->ln_state = ND6_LLINFO_STALE; 727 ln->ln_expire = time_uptime + nd6_gctimer; 728 } 729 if ((ln->ln_router = is_router) != 0) { 730 /* 731 * This means a router's state has changed from 732 * non-reachable to probably reachable, and might 733 * affect the status of associated prefixes.. 734 */ 735 pfxlist_onlink_check(); 736 } 737 } else { 738 int llchange; 739 740 /* 741 * Check if the link-layer address has changed or not. 742 */ 743 if (!lladdr) 744 llchange = 0; 745 else { 746 if (sdl->sdl_alen) { 747 if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen)) 748 llchange = 1; 749 else 750 llchange = 0; 751 } else 752 llchange = 1; 753 } 754 755 /* 756 * This is VERY complex. Look at it with care. 757 * 758 * override solicit lladdr llchange action 759 * (L: record lladdr) 760 * 761 * 0 0 n -- (2c) 762 * 0 0 y n (2b) L 763 * 0 0 y y (1) REACHABLE->STALE 764 * 0 1 n -- (2c) *->REACHABLE 765 * 0 1 y n (2b) L *->REACHABLE 766 * 0 1 y y (1) REACHABLE->STALE 767 * 1 0 n -- (2a) 768 * 1 0 y n (2a) L 769 * 1 0 y y (2a) L *->STALE 770 * 1 1 n -- (2a) *->REACHABLE 771 * 1 1 y n (2a) L *->REACHABLE 772 * 1 1 y y (2a) L *->REACHABLE 773 */ 774 if (!is_override && (lladdr && llchange)) { /* (1) */ 775 /* 776 * If state is REACHABLE, make it STALE. 777 * no other updates should be done. 778 */ 779 if (ln->ln_state == ND6_LLINFO_REACHABLE) { 780 ln->ln_state = ND6_LLINFO_STALE; 781 ln->ln_expire = time_uptime + nd6_gctimer; 782 } 783 goto freeit; 784 } else if (is_override /* (2a) */ 785 || (lladdr && !llchange) /* (2b) */ 786 || !lladdr) { /* (2c) */ 787 /* 788 * Update link-local address, if any. 789 */ 790 if (lladdr) { 791 sdl->sdl_alen = ifp->if_addrlen; 792 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen); 793 } 794 795 /* 796 * If solicited, make the state REACHABLE. 797 * If not solicited and the link-layer address was 798 * changed, make it STALE. 799 */ 800 if (is_solicited) { 801 ln->ln_state = ND6_LLINFO_REACHABLE; 802 ln->ln_byhint = 0; 803 if (ln->ln_expire) { 804 ln->ln_expire = time_uptime + 805 ND_IFINFO(ifp)->reachable; 806 } 807 } else { 808 if (lladdr && llchange) { 809 ln->ln_state = ND6_LLINFO_STALE; 810 ln->ln_expire = time_uptime + nd6_gctimer; 811 } 812 } 813 } 814 815 if (ln->ln_router && !is_router) { 816 /* 817 * The peer dropped the router flag. 818 * Remove the sender from the Default Router List and 819 * update the Destination Cache entries. 820 */ 821 struct nd_defrouter *dr; 822 struct in6_addr *in6; 823 824 in6 = &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr; 825 826 /* 827 * Lock to protect the default router list. 828 * XXX: this might be unnecessary, since this function 829 * is only called under the network software interrupt 830 * context. However, we keep it just for safety. 831 */ 832 mtx_lock(&nd6_mtx); 833 dr = defrouter_lookup(in6, rt->rt_ifp); 834 if (dr) 835 defrtrlist_del(dr); 836 mtx_unlock(&nd6_mtx); 837 838 if (dr == NULL && !ip6_forwarding && ip6_accept_rtadv) { 839 /* 840 * Even if the neighbor is not in the default 841 * router list, the neighbor may be used 842 * as a next hop for some destinations 843 * (e.g. redirect case). So we must 844 * call rt6_flush explicitly. 845 */ 846 rt6_flush(&ip6->ip6_src, rt->rt_ifp); 847 } 848 } 849 ln->ln_router = is_router; 850 } 851 rt->rt_flags &= ~RTF_REJECT; 852 ln->ln_asked = 0; 853 if (ln->ln_hold) { 854 /* 855 * we assume ifp is not a loopback here, so just set the 2nd 856 * argument as the 1st one. 857 */ 858 nd6_output(ifp, ifp, ln->ln_hold, 859 (struct sockaddr_in6 *)rt_key(rt), rt); 860 ln->ln_hold = NULL; 861 } 862 863 freeit: 864 m_freem(m); 865 return; 866 867 bad: 868 icmp6stat.icp6s_badna++; 869 m_freem(m); 870 } 871 872 /* 873 * Neighbor advertisement output handling. 874 * 875 * Based on RFC 2461 876 * 877 * the following items are not implemented yet: 878 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 879 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 880 */ 881 void 882 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6, 883 const struct in6_addr *taddr6, u_long flags, 884 int tlladdr, /* 1 if include target link-layer address */ 885 struct sockaddr *sdl0) /* sockaddr_dl (= proxy NA) or NULL */ 886 { 887 struct mbuf *m; 888 struct ip6_hdr *ip6; 889 struct nd_neighbor_advert *nd_na; 890 struct in6_ifaddr *ia = NULL; 891 struct ip6_moptions im6o; 892 int icmp6len; 893 int maxlen; 894 caddr_t mac; 895 struct ifnet *outif = NULL; 896 897 /* estimate the size of message */ 898 maxlen = sizeof(*ip6) + sizeof(*nd_na); 899 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 900 if (max_linkhdr + maxlen > MCLBYTES) { 901 #ifdef DIAGNOSTIC 902 kprintf("nd6_na_output: max_linkhdr + maxlen > MCLBYTES " 903 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES); 904 #endif 905 return; 906 } 907 908 m = m_getb(max_linkhdr + maxlen, M_NOWAIT, MT_DATA, M_PKTHDR); 909 if (m == NULL) 910 return; 911 912 if (IN6_IS_ADDR_MULTICAST(daddr6)) { 913 m->m_flags |= M_MCAST; 914 im6o.im6o_multicast_ifp = ifp; 915 im6o.im6o_multicast_hlim = 255; 916 im6o.im6o_multicast_loop = 0; 917 } 918 919 icmp6len = sizeof(*nd_na); 920 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 921 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 922 923 /* fill neighbor advertisement packet */ 924 ip6 = mtod(m, struct ip6_hdr *); 925 ip6->ip6_flow = 0; 926 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 927 ip6->ip6_vfc |= IPV6_VERSION; 928 ip6->ip6_nxt = IPPROTO_ICMPV6; 929 ip6->ip6_hlim = 255; 930 if (IN6_IS_ADDR_UNSPECIFIED(daddr6)) { 931 /* reply to DAD */ 932 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 933 ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index); 934 ip6->ip6_dst.s6_addr32[1] = 0; 935 ip6->ip6_dst.s6_addr32[2] = 0; 936 ip6->ip6_dst.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 937 flags &= ~ND_NA_FLAG_SOLICITED; 938 } else 939 ip6->ip6_dst = *daddr6; 940 941 /* 942 * Select a source whose scope is the same as that of the dest. 943 */ 944 ia = in6_ifawithifp(ifp, &ip6->ip6_dst); 945 if (ia == NULL) { 946 m_freem(m); 947 return; 948 } 949 ip6->ip6_src = ia->ia_addr.sin6_addr; 950 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 951 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 952 nd_na->nd_na_code = 0; 953 nd_na->nd_na_target = *taddr6; 954 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 955 956 /* 957 * "tlladdr" indicates NS's condition for adding tlladdr or not. 958 * see nd6_ns_input() for details. 959 * Basically, if NS packet is sent to unicast/anycast addr, 960 * target lladdr option SHOULD NOT be included. 961 */ 962 mac = NULL; 963 if (tlladdr) { 964 /* 965 * sdl0 != NULL indicates proxy NA. If we do proxy, use 966 * lladdr in sdl0. If we are not proxying (sending NA for 967 * my address) use lladdr configured for the interface. 968 */ 969 if (sdl0 == NULL) { 970 #ifdef CARP 971 if (ifp->if_carp) 972 mac = carp_macmatch6(ifp->if_carp, m, taddr6); 973 if (mac == NULL) 974 mac = nd6_ifptomac(ifp); 975 #else 976 mac = nd6_ifptomac(ifp); 977 #endif 978 } else if (sdl0->sa_family == AF_LINK) { 979 struct sockaddr_dl *sdl; 980 sdl = (struct sockaddr_dl *)sdl0; 981 if (sdl->sdl_alen == ifp->if_addrlen) 982 mac = LLADDR(sdl); 983 } 984 } 985 if (mac != NULL) { 986 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 987 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 988 989 /* roundup to 8 bytes alignment! */ 990 optlen = (optlen + 7) & ~7; 991 992 m->m_pkthdr.len += optlen; 993 m->m_len += optlen; 994 icmp6len += optlen; 995 bzero((caddr_t)nd_opt, optlen); 996 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 997 nd_opt->nd_opt_len = optlen >> 3; 998 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 999 } else 1000 flags &= ~ND_NA_FLAG_OVERRIDE; 1001 1002 ip6->ip6_plen = htons((u_short)icmp6len); 1003 nd_na->nd_na_flags_reserved = flags; 1004 nd_na->nd_na_cksum = 0; 1005 nd_na->nd_na_cksum = 1006 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1007 1008 ip6_output(m, NULL, NULL, 0, &im6o, &outif, NULL); 1009 if (outif) { 1010 icmp6_ifstat_inc(outif, ifs6_out_msg); 1011 icmp6_ifstat_inc(outif, ifs6_out_neighboradvert); 1012 } 1013 icmp6stat.icp6s_outhist[ND_NEIGHBOR_ADVERT]++; 1014 } 1015 1016 caddr_t 1017 nd6_ifptomac(struct ifnet *ifp) 1018 { 1019 switch (ifp->if_type) { 1020 case IFT_ETHER: 1021 case IFT_IEEE1394: 1022 #ifdef IFT_L2VLAN 1023 case IFT_L2VLAN: 1024 #endif 1025 #ifdef IFT_IEEE80211 1026 case IFT_IEEE80211: 1027 #endif 1028 #ifdef IFT_CARP 1029 case IFT_CARP: 1030 #endif 1031 return ((caddr_t)(ifp + 1)); 1032 default: 1033 return NULL; 1034 } 1035 } 1036 1037 struct netmsg_dad { 1038 struct netmsg_base base; 1039 struct dadq *dadq; 1040 }; 1041 1042 struct dadq { 1043 TAILQ_ENTRY(dadq) dad_list; 1044 struct ifaddr *dad_ifa; 1045 int dad_count; /* max NS to send */ 1046 int dad_ns_tcount; /* # of trials to send NS */ 1047 int dad_ns_ocount; /* NS sent so far */ 1048 int dad_ns_icount; 1049 int dad_na_icount; 1050 struct callout dad_timer_ch; 1051 struct netmsg_dad dad_nmsg; 1052 }; 1053 TAILQ_HEAD(dadq_head, dadq); 1054 1055 static struct dadq_head dadq = TAILQ_HEAD_INITIALIZER(dadq); 1056 1057 static struct dadq * 1058 nd6_dad_find(struct ifaddr *ifa) 1059 { 1060 struct dadq *dp; 1061 1062 ASSERT_NETISR0; 1063 1064 TAILQ_FOREACH(dp, &dadq, dad_list) { 1065 if (dp->dad_ifa == ifa) 1066 return dp; 1067 } 1068 return NULL; 1069 } 1070 1071 static void 1072 nd6_dad_starttimer(struct dadq *dp, int ticks) 1073 { 1074 ASSERT_NETISR0; 1075 callout_reset(&dp->dad_timer_ch, ticks, nd6_dad_timer, dp); 1076 } 1077 1078 static void 1079 nd6_dad_stoptimer(struct dadq *dp) 1080 { 1081 ASSERT_NETISR0; 1082 callout_stop(&dp->dad_timer_ch); 1083 } 1084 1085 /* 1086 * Start Duplicated Address Detection (DAD) for specified interface address. 1087 */ 1088 void 1089 nd6_dad_start(struct ifaddr *ifa, 1090 int *tick) /* minimum delay ticks for IFF_UP event */ 1091 { 1092 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1093 struct dadq *dp; 1094 1095 ASSERT_NETISR0; 1096 1097 /* 1098 * If we don't need DAD, don't do it. 1099 * There are several cases: 1100 * - DAD is disabled (ip6_dad_count == 0) 1101 * - the interface address is anycast 1102 */ 1103 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1104 log(LOG_DEBUG, 1105 "nd6_dad_start: called with non-tentative address " 1106 "%s(%s)\n", 1107 ip6_sprintf(&ia->ia_addr.sin6_addr), 1108 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1109 return; 1110 } 1111 if (ia->ia6_flags & IN6_IFF_ANYCAST) { 1112 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1113 return; 1114 } 1115 if (!ip6_dad_count) { 1116 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1117 return; 1118 } 1119 if (!ifa->ifa_ifp) 1120 panic("nd6_dad_start: ifa->ifa_ifp == NULL"); 1121 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1122 return; 1123 if (nd6_dad_find(ifa) != NULL) { 1124 /* DAD already in progress */ 1125 return; 1126 } 1127 1128 dp = nd6_dad_create(ifa); 1129 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1130 ip6_sprintf(&ia->ia_addr.sin6_addr))); 1131 1132 /* 1133 * Send NS packet for DAD, dp->dad_count times. 1134 * Note that we must delay the first transmission, if this is the 1135 * first packet to be sent from the interface after interface 1136 * (re)initialization. 1137 */ 1138 if (tick == NULL) { 1139 nd6_dad_ns_output(dp); 1140 nd6_dad_starttimer(dp, 1141 ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1142 } else { 1143 int ntick; 1144 1145 if (*tick == 0) 1146 ntick = krandom() % (MAX_RTR_SOLICITATION_DELAY * hz); 1147 else 1148 ntick = *tick + krandom() % (hz / 2); 1149 *tick = ntick; 1150 nd6_dad_starttimer(dp, ntick); 1151 } 1152 } 1153 1154 /* 1155 * Terminate DAD unconditionally. Used for address removals. 1156 */ 1157 void 1158 nd6_dad_stop(struct ifaddr *ifa) 1159 { 1160 struct dadq *dp; 1161 1162 ASSERT_NETISR0; 1163 1164 dp = nd6_dad_find(ifa); 1165 if (!dp) { 1166 /* DAD wasn't started yet */ 1167 return; 1168 } 1169 nd6_dad_destroy(dp); 1170 } 1171 1172 static struct dadq * 1173 nd6_dad_create(struct ifaddr *ifa) 1174 { 1175 struct netmsg_dad *dm; 1176 struct dadq *dp; 1177 1178 ASSERT_NETISR0; 1179 1180 dp = kmalloc(sizeof(*dp), M_IP6NDP, M_INTWAIT | M_ZERO); 1181 callout_init_mp(&dp->dad_timer_ch); 1182 1183 dm = &dp->dad_nmsg; 1184 netmsg_init(&dm->base, NULL, &netisr_adone_rport, 1185 MSGF_DROPABLE | MSGF_PRIORITY, nd6_dad_timer_handler); 1186 dm->dadq = dp; 1187 1188 dp->dad_ifa = ifa; 1189 IFAREF(ifa); /* just for safety */ 1190 1191 /* Send NS packet for DAD, ip6_dad_count times. */ 1192 dp->dad_count = ip6_dad_count; 1193 1194 TAILQ_INSERT_TAIL(&dadq, dp, dad_list); 1195 1196 return dp; 1197 } 1198 1199 static void 1200 nd6_dad_destroy(struct dadq *dp) 1201 { 1202 struct lwkt_msg *lmsg = &dp->dad_nmsg.base.lmsg; 1203 1204 ASSERT_NETISR0; 1205 1206 TAILQ_REMOVE(&dadq, dp, dad_list); 1207 1208 nd6_dad_stoptimer(dp); 1209 1210 crit_enter(); 1211 if ((lmsg->ms_flags & MSGF_DONE) == 0) 1212 lwkt_dropmsg(lmsg); 1213 crit_exit(); 1214 1215 IFAFREE(dp->dad_ifa); 1216 kfree(dp, M_IP6NDP); 1217 } 1218 1219 static void 1220 nd6_dad_timer(void *xdp) 1221 { 1222 struct dadq *dp = xdp; 1223 struct lwkt_msg *lmsg = &dp->dad_nmsg.base.lmsg; 1224 1225 KASSERT(mycpuid == 0, ("dad timer not on cpu0")); 1226 1227 crit_enter(); 1228 if (lmsg->ms_flags & MSGF_DONE) 1229 lwkt_sendmsg_oncpu(netisr_cpuport(0), lmsg); 1230 crit_exit(); 1231 } 1232 1233 static void 1234 nd6_dad_timer_handler(netmsg_t msg) 1235 { 1236 struct netmsg_dad *dm = (struct netmsg_dad *)msg; 1237 struct dadq *dp = dm->dadq; 1238 struct ifaddr *ifa = dp->dad_ifa; 1239 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1240 1241 ASSERT_NETISR0; 1242 1243 /* Reply ASAP */ 1244 crit_enter(); 1245 lwkt_replymsg(&dm->base.lmsg, 0); 1246 crit_exit(); 1247 1248 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1249 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1250 "%s(%s)\n", 1251 ip6_sprintf(&ia->ia_addr.sin6_addr), 1252 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1253 goto destroy; 1254 } 1255 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1256 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1257 "%s(%s)\n", 1258 ip6_sprintf(&ia->ia_addr.sin6_addr), 1259 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1260 goto destroy; 1261 } 1262 1263 /* Timed out with IFF_{RUNNING,UP} check */ 1264 if (dp->dad_ns_tcount > dad_maxtry) { 1265 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n", 1266 if_name(ifa->ifa_ifp))); 1267 goto destroy; 1268 } 1269 1270 /* Need more checks? */ 1271 if (dp->dad_ns_ocount < dp->dad_count) { 1272 /* 1273 * We have more NS to go. Send NS packet for DAD. 1274 */ 1275 nd6_dad_ns_output(dp); 1276 nd6_dad_starttimer(dp, 1277 ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1278 } else { 1279 /* 1280 * We have transmitted sufficient number of DAD packets. 1281 * See what we've got. 1282 */ 1283 int duplicate; 1284 1285 duplicate = 0; 1286 1287 if (dp->dad_na_icount) { 1288 /* 1289 * the check is in nd6_dad_na_input(), 1290 * but just in case 1291 */ 1292 duplicate++; 1293 } 1294 1295 if (dp->dad_ns_icount) { 1296 #if 0 /* heuristics */ 1297 /* 1298 * if 1299 * - we have sent many(?) DAD NS, and 1300 * - the number of NS we sent equals to the 1301 * number of NS we've got, and 1302 * - we've got no NA 1303 * we may have a faulty network card/driver which 1304 * loops back multicasts to myself. 1305 */ 1306 if (3 < dp->dad_count 1307 && dp->dad_ns_icount == dp->dad_count 1308 && dp->dad_na_icount == 0) { 1309 log(LOG_INFO, "DAD questionable for %s(%s): " 1310 "network card loops back multicast?\n", 1311 ip6_sprintf(&ia->ia_addr.sin6_addr), 1312 if_name(ifa->ifa_ifp)); 1313 /* XXX consider it a duplicate or not? */ 1314 /* duplicate++; */ 1315 } else { 1316 /* We've seen NS, means DAD has failed. */ 1317 duplicate++; 1318 } 1319 #else 1320 /* We've seen NS, means DAD has failed. */ 1321 duplicate++; 1322 #endif 1323 } 1324 1325 if (duplicate) { 1326 /* dp will be freed in nd6_dad_duplicated() */ 1327 dp = NULL; 1328 nd6_dad_duplicated(ifa); 1329 } else { 1330 /* 1331 * We are done with DAD. No NA came, no NS came. 1332 * duplicated address found. 1333 */ 1334 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1335 nd6log((LOG_DEBUG, 1336 "%s: DAD complete for %s - no duplicates found\n", 1337 if_name(ifa->ifa_ifp), 1338 ip6_sprintf(&ia->ia_addr.sin6_addr))); 1339 goto destroy; 1340 } 1341 } 1342 return; 1343 destroy: 1344 nd6_dad_destroy(dp); 1345 } 1346 1347 static void 1348 nd6_dad_duplicated(struct ifaddr *ifa) 1349 { 1350 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1351 struct dadq *dp; 1352 1353 ASSERT_NETISR0; 1354 1355 dp = nd6_dad_find(ifa); 1356 if (dp == NULL) { 1357 log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n"); 1358 return; 1359 } 1360 1361 /* 1362 * We are done with DAD, with duplicated address found. (failure) 1363 */ 1364 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1365 "NS in/out=%d/%d, NA in=%d\n", 1366 if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr), 1367 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount); 1368 1369 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1370 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1371 1372 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1373 if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr)); 1374 log(LOG_ERR, "%s: manual intervention required\n", 1375 if_name(ifa->ifa_ifp)); 1376 1377 nd6_dad_destroy(dp); 1378 } 1379 1380 static void 1381 nd6_dad_ns_output(struct dadq *dp) 1382 { 1383 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1384 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1385 1386 ASSERT_NETISR0; 1387 1388 dp->dad_ns_tcount++; 1389 if (!(ifp->if_flags & IFF_UP)) { 1390 #if 0 1391 kprintf("%s: interface down?\n", if_name(ifp)); 1392 #endif 1393 return; 1394 } 1395 if (!(ifp->if_flags & IFF_RUNNING)) { 1396 #if 0 1397 kprintf("%s: interface not running?\n", if_name(ifp)); 1398 #endif 1399 return; 1400 } 1401 1402 dp->dad_ns_ocount++; 1403 nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1); 1404 } 1405 1406 static void 1407 nd6_dad_ns_input(struct ifaddr *ifa) 1408 { 1409 struct in6_ifaddr *ia; 1410 const struct in6_addr *taddr6; 1411 struct dadq *dp; 1412 int duplicate; 1413 1414 ASSERT_NETISR0; 1415 1416 if (!ifa) 1417 panic("ifa == NULL in nd6_dad_ns_input"); 1418 1419 ia = (struct in6_ifaddr *)ifa; 1420 taddr6 = &ia->ia_addr.sin6_addr; 1421 duplicate = 0; 1422 dp = nd6_dad_find(ifa); 1423 1424 /* Quickhack - completely ignore DAD NS packets */ 1425 if (dad_ignore_ns) { 1426 nd6log((LOG_INFO, 1427 "nd6_dad_ns_input: ignoring DAD NS packet for " 1428 "address %s(%s)\n", ip6_sprintf(taddr6), 1429 if_name(ifa->ifa_ifp))); 1430 return; 1431 } 1432 1433 /* 1434 * if I'm yet to start DAD, someone else started using this address 1435 * first. I have a duplicate and you win. 1436 */ 1437 if (!dp || dp->dad_ns_ocount == 0) 1438 duplicate++; 1439 1440 /* XXX more checks for loopback situation - see nd6_dad_timer too */ 1441 1442 if (duplicate) { 1443 dp = NULL; /* will be freed in nd6_dad_duplicated() */ 1444 nd6_dad_duplicated(ifa); 1445 } else { 1446 /* 1447 * not sure if I got a duplicate. 1448 * increment ns count and see what happens. 1449 */ 1450 if (dp) 1451 dp->dad_ns_icount++; 1452 } 1453 } 1454 1455 static void 1456 nd6_dad_na_input(struct ifaddr *ifa) 1457 { 1458 struct dadq *dp; 1459 1460 ASSERT_NETISR0; 1461 1462 if (!ifa) 1463 panic("ifa == NULL in nd6_dad_na_input"); 1464 1465 dp = nd6_dad_find(ifa); 1466 if (dp) 1467 dp->dad_na_icount++; 1468 1469 /* remove the address. */ 1470 nd6_dad_duplicated(ifa); 1471 } 1472