nd6_nbr.c revision 1.137
1 /* $NetBSD: nd6_nbr.c,v 1.137 2017/02/21 03:58:24 ozaki-r Exp $ */ 2 /* $KAME: nd6_nbr.c,v 1.61 2001/02/10 16:06:14 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 <sys/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: nd6_nbr.c,v 1.137 2017/02/21 03:58:24 ozaki-r Exp $"); 35 36 #ifdef _KERNEL_OPT 37 #include "opt_inet.h" 38 #include "opt_net_mpsafe.h" 39 #endif 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/kmem.h> 44 #include <sys/mbuf.h> 45 #include <sys/socket.h> 46 #include <sys/socketvar.h> 47 #include <sys/sockio.h> 48 #include <sys/time.h> 49 #include <sys/kernel.h> 50 #include <sys/errno.h> 51 #include <sys/ioctl.h> 52 #include <sys/syslog.h> 53 #include <sys/queue.h> 54 #include <sys/callout.h> 55 56 #include <net/if.h> 57 #include <net/if_types.h> 58 #include <net/if_dl.h> 59 #include <net/route.h> 60 61 #include <netinet/in.h> 62 #include <netinet/in_var.h> 63 #include <netinet6/in6_var.h> 64 #include <netinet6/in6_ifattach.h> 65 #include <netinet/ip6.h> 66 #include <netinet6/ip6_var.h> 67 #include <netinet6/scope6_var.h> 68 #include <netinet6/nd6.h> 69 #include <netinet/icmp6.h> 70 #include <netinet6/icmp6_private.h> 71 72 #include "carp.h" 73 #if NCARP > 0 74 #include <netinet/ip_carp.h> 75 #endif 76 77 #include <net/net_osdep.h> 78 79 struct dadq; 80 static struct dadq *nd6_dad_find(struct ifaddr *); 81 static void nd6_dad_starttimer(struct dadq *, int); 82 static void nd6_dad_stoptimer(struct dadq *); 83 static void nd6_dad_timer(struct ifaddr *); 84 static void nd6_dad_ns_output(struct dadq *, struct ifaddr *); 85 static void nd6_dad_ns_input(struct ifaddr *); 86 static void nd6_dad_na_input(struct ifaddr *); 87 static void nd6_dad_duplicated(struct ifaddr *); 88 89 static int dad_ignore_ns = 0; /* ignore NS in DAD - specwise incorrect*/ 90 static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */ 91 92 /* 93 * Input a Neighbor Solicitation Message. 94 * 95 * Based on RFC 2461 96 * Based on RFC 2462 (duplicate address detection) 97 */ 98 void 99 nd6_ns_input(struct mbuf *m, int off, int icmp6len) 100 { 101 struct ifnet *ifp; 102 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 103 struct nd_neighbor_solicit *nd_ns; 104 struct in6_addr saddr6 = ip6->ip6_src; 105 struct in6_addr daddr6 = ip6->ip6_dst; 106 struct in6_addr taddr6; 107 struct in6_addr myaddr6; 108 char *lladdr = NULL; 109 struct ifaddr *ifa = NULL; 110 int lladdrlen = 0; 111 int anycast = 0, proxy = 0, tentative = 0; 112 int router = ip6_forwarding; 113 int tlladdr; 114 union nd_opts ndopts; 115 const struct sockaddr_dl *proxydl = NULL; 116 struct psref psref; 117 struct psref psref_ia; 118 char ip6buf[INET6_ADDRSTRLEN], ip6buf2[INET6_ADDRSTRLEN]; 119 120 ifp = m_get_rcvif_psref(m, &psref); 121 if (ifp == NULL) 122 goto freeit; 123 124 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); 125 if (nd_ns == NULL) { 126 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 127 m_put_rcvif_psref(ifp, &psref); 128 return; 129 } 130 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ 131 taddr6 = nd_ns->nd_ns_target; 132 if (in6_setscope(&taddr6, ifp, NULL) != 0) 133 goto bad; 134 135 if (ip6->ip6_hlim != 255) { 136 nd6log(LOG_ERR, "invalid hlim (%d) from %s to %s on %s\n", 137 ip6->ip6_hlim, IN6_PRINT(ip6buf, &ip6->ip6_src), 138 IN6_PRINT(ip6buf2, &ip6->ip6_dst), if_name(ifp)); 139 goto bad; 140 } 141 142 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 143 /* dst has to be a solicited node multicast address. */ 144 /* don't check ifindex portion */ 145 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 146 daddr6.s6_addr32[1] == 0 && 147 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 148 daddr6.s6_addr8[12] == 0xff) { 149 ; /* good */ 150 } else { 151 nd6log(LOG_INFO, "bad DAD packet (wrong ip6 dst)\n"); 152 goto bad; 153 } 154 } else { 155 struct sockaddr_in6 ssin6; 156 157 /* 158 * Make sure the source address is from a neighbor's address. 159 */ 160 sockaddr_in6_init(&ssin6, &saddr6, 0, 0, 0); 161 if (nd6_is_addr_neighbor(&ssin6, ifp) == 0) { 162 nd6log(LOG_INFO, 163 "NS packet from non-neighbor %s on %s\n", 164 IN6_PRINT(ip6buf, &saddr6), if_name(ifp)); 165 goto bad; 166 } 167 } 168 169 170 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 171 nd6log(LOG_INFO, "bad NS target (multicast)\n"); 172 goto bad; 173 } 174 175 icmp6len -= sizeof(*nd_ns); 176 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 177 if (nd6_options(&ndopts) < 0) { 178 nd6log(LOG_INFO, "invalid ND option, ignored\n"); 179 /* nd6_options have incremented stats */ 180 goto freeit; 181 } 182 183 if (ndopts.nd_opts_src_lladdr) { 184 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 185 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 186 } 187 188 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 189 nd6log(LOG_INFO, 190 "bad DAD packet (link-layer address option)\n"); 191 goto bad; 192 } 193 194 /* 195 * Attaching target link-layer address to the NA? 196 * (RFC 2461 7.2.4) 197 * 198 * NS IP dst is multicast MUST add 199 * Otherwise MAY be omitted 200 * 201 * In this implementation, we omit the target link-layer address 202 * in the "MAY" case. 203 */ 204 #if 0 /* too much! */ 205 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &daddr6); 206 if (ifa && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST)) 207 tlladdr = 0; 208 else 209 #endif 210 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 211 tlladdr = 0; 212 else 213 tlladdr = 1; 214 215 /* 216 * Target address (taddr6) must be either: 217 * (1) Valid unicast/anycast address for my receiving interface, 218 * (2) Unicast address for which I'm offering proxy service, or 219 * (3) "tentative" address on which DAD is being performed. 220 */ 221 /* (1) and (3) check. */ 222 #if NCARP > 0 223 if (ifp->if_carp && ifp->if_type != IFT_CARP) { 224 int s = pserialize_read_enter(); 225 ifa = carp_iamatch6(ifp->if_carp, &taddr6); 226 if (ifa != NULL) 227 ifa_acquire(ifa, &psref_ia); 228 pserialize_read_exit(s); 229 } else 230 ifa = NULL; 231 if (!ifa) 232 ifa = (struct ifaddr *)in6ifa_ifpwithaddr_psref(ifp, &taddr6, 233 &psref_ia); 234 #else 235 ifa = (struct ifaddr *)in6ifa_ifpwithaddr_psref(ifp, &taddr6, 236 &psref_ia); 237 #endif 238 239 /* (2) check. */ 240 if (ifa == NULL) { 241 struct rtentry *rt; 242 struct sockaddr_in6 tsin6; 243 244 sockaddr_in6_init(&tsin6, &taddr6, 0, 0, 0); 245 246 rt = rtalloc1(sin6tosa(&tsin6), 0); 247 if (rt && (rt->rt_flags & RTF_ANNOUNCE) != 0 && 248 rt->rt_gateway->sa_family == AF_LINK) { 249 /* 250 * proxy NDP for single entry 251 */ 252 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal_psref(ifp, 253 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST, &psref_ia); 254 if (ifa) { 255 proxy = 1; 256 proxydl = satocsdl(rt->rt_gateway); 257 router = 0; /* XXX */ 258 } 259 } 260 if (rt) 261 rt_unref(rt); 262 } 263 if (ifa == NULL) { 264 /* 265 * We've got an NS packet, and we don't have that address 266 * assigned for us. We MUST silently ignore it. 267 * See RFC2461 7.2.3. 268 */ 269 goto freeit; 270 } 271 myaddr6 = *IFA_IN6(ifa); 272 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 273 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 274 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 275 goto freeit; 276 277 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 278 nd6log(LOG_INFO, "lladdrlen mismatch for %s " 279 "(if %d, NS packet %d)\n", 280 IN6_PRINT(ip6buf, &taddr6), 281 ifp->if_addrlen, lladdrlen - 2); 282 goto bad; 283 } 284 285 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 286 nd6log(LOG_INFO, "duplicate IP6 address %s\n", 287 IN6_PRINT(ip6buf, &saddr6)); 288 goto freeit; 289 } 290 291 /* 292 * We have neighbor solicitation packet, with target address equals to 293 * one of my tentative address. 294 * 295 * src addr how to process? 296 * --- --- 297 * multicast of course, invalid (rejected in ip6_input) 298 * unicast somebody is doing address resolution -> ignore 299 * unspec dup address detection 300 * 301 * The processing is defined in RFC 2462. 302 */ 303 if (tentative) { 304 /* 305 * If source address is unspecified address, it is for 306 * duplicate address detection. 307 * 308 * If not, the packet is for addess resolution; 309 * silently ignore it. 310 */ 311 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 312 nd6_dad_ns_input(ifa); 313 ifa_release(ifa, &psref_ia); 314 ifa = NULL; 315 316 goto freeit; 317 } 318 ifa_release(ifa, &psref_ia); 319 ifa = NULL; 320 321 /* 322 * If the source address is unspecified address, entries must not 323 * be created or updated. 324 * It looks that sender is performing DAD. Output NA toward 325 * all-node multicast address, to tell the sender that I'm using 326 * the address. 327 * S bit ("solicited") must be zero. 328 */ 329 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 330 struct in6_addr in6_all; 331 332 in6_all = in6addr_linklocal_allnodes; 333 if (in6_setscope(&in6_all, ifp, NULL) != 0) 334 goto bad; 335 nd6_na_output(ifp, &in6_all, &taddr6, 336 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 337 (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0), 338 tlladdr, (const struct sockaddr *)proxydl); 339 goto freeit; 340 } 341 342 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_NEIGHBOR_SOLICIT, 0); 343 344 nd6_na_output(ifp, &saddr6, &taddr6, 345 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 346 (router ? ND_NA_FLAG_ROUTER : 0) | ND_NA_FLAG_SOLICITED, 347 tlladdr, (const struct sockaddr *)proxydl); 348 freeit: 349 ifa_release(ifa, &psref_ia); 350 m_put_rcvif_psref(ifp, &psref); 351 m_freem(m); 352 return; 353 354 bad: 355 nd6log(LOG_ERR, "src=%s\n", IN6_PRINT(ip6buf, &saddr6)); 356 nd6log(LOG_ERR, "dst=%s\n", IN6_PRINT(ip6buf, &daddr6)); 357 nd6log(LOG_ERR, "tgt=%s\n", IN6_PRINT(ip6buf, &taddr6)); 358 ICMP6_STATINC(ICMP6_STAT_BADNS); 359 ifa_release(ifa, &psref_ia); 360 m_put_rcvif_psref(ifp, &psref); 361 m_freem(m); 362 } 363 364 /* 365 * Output a Neighbor Solicitation Message. Caller specifies: 366 * - ICMP6 header source IP6 address 367 * - ND6 header target IP6 address 368 * - ND6 header source datalink address 369 * 370 * Based on RFC 2461 371 * Based on RFC 2462 (duplicate address detection) 372 */ 373 void 374 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6, 375 const struct in6_addr *taddr6, 376 struct in6_addr *hsrc, 377 int dad /* duplicate address detection */) 378 { 379 struct mbuf *m; 380 struct ip6_hdr *ip6; 381 struct nd_neighbor_solicit *nd_ns; 382 struct in6_addr *src, src_in; 383 struct ip6_moptions im6o; 384 int icmp6len; 385 int maxlen; 386 const void *mac; 387 struct route ro; 388 389 if (IN6_IS_ADDR_MULTICAST(taddr6)) 390 return; 391 392 memset(&ro, 0, sizeof(ro)); 393 394 /* estimate the size of message */ 395 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 396 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 397 #ifdef DIAGNOSTIC 398 if (max_linkhdr + maxlen >= MCLBYTES) { 399 printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES " 400 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES); 401 panic("nd6_ns_output: insufficient MCLBYTES"); 402 /* NOTREACHED */ 403 } 404 #endif 405 406 MGETHDR(m, M_DONTWAIT, MT_DATA); 407 if (m && max_linkhdr + maxlen >= MHLEN) { 408 MCLGET(m, M_DONTWAIT); 409 if ((m->m_flags & M_EXT) == 0) { 410 m_free(m); 411 m = NULL; 412 } 413 } 414 if (m == NULL) 415 return; 416 m_reset_rcvif(m); 417 418 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 419 m->m_flags |= M_MCAST; 420 im6o.im6o_multicast_if_index = if_get_index(ifp); 421 im6o.im6o_multicast_hlim = 255; 422 im6o.im6o_multicast_loop = 0; 423 } 424 425 icmp6len = sizeof(*nd_ns); 426 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 427 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 428 429 /* fill neighbor solicitation packet */ 430 ip6 = mtod(m, struct ip6_hdr *); 431 ip6->ip6_flow = 0; 432 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 433 ip6->ip6_vfc |= IPV6_VERSION; 434 /* ip6->ip6_plen will be set later */ 435 ip6->ip6_nxt = IPPROTO_ICMPV6; 436 ip6->ip6_hlim = 255; 437 if (daddr6) 438 ip6->ip6_dst = *daddr6; 439 else { 440 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 441 ip6->ip6_dst.s6_addr16[1] = 0; 442 ip6->ip6_dst.s6_addr32[1] = 0; 443 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 444 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 445 ip6->ip6_dst.s6_addr8[12] = 0xff; 446 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 447 goto bad; 448 } 449 if (!dad) { 450 int s; 451 /* 452 * RFC2461 7.2.2: 453 * "If the source address of the packet prompting the 454 * solicitation is the same as one of the addresses assigned 455 * to the outgoing interface, that address SHOULD be placed 456 * in the IP Source Address of the outgoing solicitation. 457 * Otherwise, any one of the addresses assigned to the 458 * interface should be used." 459 * 460 * We use the source address for the prompting packet 461 * (hsrc), if: 462 * - hsrc is given from the caller (by giving "ln"), and 463 * - hsrc belongs to the outgoing interface. 464 * Otherwise, we perform the source address selection as usual. 465 */ 466 s = pserialize_read_enter(); 467 if (hsrc && in6ifa_ifpwithaddr(ifp, hsrc)) 468 src = hsrc; 469 else { 470 int error; 471 struct sockaddr_in6 dst_sa; 472 473 sockaddr_in6_init(&dst_sa, &ip6->ip6_dst, 0, 0, 0); 474 475 error = in6_selectsrc(&dst_sa, NULL, 476 NULL, &ro, NULL, NULL, NULL, &src_in); 477 if (error != 0) { 478 char ip6buf[INET6_ADDRSTRLEN]; 479 nd6log(LOG_DEBUG, "source can't be " 480 "determined: dst=%s, error=%d\n", 481 IN6_PRINT(ip6buf, &dst_sa.sin6_addr), 482 error); 483 pserialize_read_exit(s); 484 goto bad; 485 } 486 src = &src_in; 487 } 488 pserialize_read_exit(s); 489 } else { 490 /* 491 * Source address for DAD packet must always be IPv6 492 * unspecified address. (0::0) 493 * We actually don't have to 0-clear the address (we did it 494 * above), but we do so here explicitly to make the intention 495 * clearer. 496 */ 497 memset(&src_in, 0, sizeof(src_in)); 498 src = &src_in; 499 } 500 ip6->ip6_src = *src; 501 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 502 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 503 nd_ns->nd_ns_code = 0; 504 nd_ns->nd_ns_reserved = 0; 505 nd_ns->nd_ns_target = *taddr6; 506 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 507 508 /* 509 * Add source link-layer address option. 510 * 511 * spec implementation 512 * --- --- 513 * DAD packet MUST NOT do not add the option 514 * there's no link layer address: 515 * impossible do not add the option 516 * there's link layer address: 517 * Multicast NS MUST add one add the option 518 * Unicast NS SHOULD add one add the option 519 */ 520 if (!dad && (mac = nd6_ifptomac(ifp))) { 521 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 522 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 523 /* 8 byte alignments... */ 524 optlen = (optlen + 7) & ~7; 525 526 m->m_pkthdr.len += optlen; 527 m->m_len += optlen; 528 icmp6len += optlen; 529 memset((void *)nd_opt, 0, optlen); 530 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 531 nd_opt->nd_opt_len = optlen >> 3; 532 memcpy((void *)(nd_opt + 1), mac, ifp->if_addrlen); 533 } 534 535 ip6->ip6_plen = htons((u_int16_t)icmp6len); 536 nd_ns->nd_ns_cksum = 0; 537 nd_ns->nd_ns_cksum = 538 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 539 540 ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL, NULL); 541 icmp6_ifstat_inc(ifp, ifs6_out_msg); 542 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 543 ICMP6_STATINC(ICMP6_STAT_OUTHIST + ND_NEIGHBOR_SOLICIT); 544 545 rtcache_free(&ro); 546 return; 547 548 bad: 549 rtcache_free(&ro); 550 m_freem(m); 551 return; 552 } 553 554 /* 555 * Neighbor advertisement input handling. 556 * 557 * Based on RFC 2461 558 * Based on RFC 2462 (duplicate address detection) 559 * 560 * the following items are not implemented yet: 561 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 562 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 563 */ 564 void 565 nd6_na_input(struct mbuf *m, int off, int icmp6len) 566 { 567 struct ifnet *ifp; 568 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 569 struct nd_neighbor_advert *nd_na; 570 struct in6_addr saddr6 = ip6->ip6_src; 571 struct in6_addr daddr6 = ip6->ip6_dst; 572 struct in6_addr taddr6; 573 int flags; 574 int is_router; 575 int is_solicited; 576 int is_override; 577 char *lladdr = NULL; 578 int lladdrlen = 0; 579 struct ifaddr *ifa; 580 struct llentry *ln = NULL; 581 union nd_opts ndopts; 582 struct sockaddr_in6 ssin6; 583 int rt_announce; 584 bool checklink = false; 585 struct psref psref; 586 struct psref psref_ia; 587 char ip6buf[INET6_ADDRSTRLEN], ip6buf2[INET6_ADDRSTRLEN]; 588 589 ifp = m_get_rcvif_psref(m, &psref); 590 if (ifp == NULL) 591 goto freeit; 592 593 if (ip6->ip6_hlim != 255) { 594 nd6log(LOG_ERR, 595 "invalid hlim (%d) from %s to %s on %s\n", 596 ip6->ip6_hlim, IN6_PRINT(ip6buf, &ip6->ip6_src), 597 IN6_PRINT(ip6buf2, &ip6->ip6_dst), if_name(ifp)); 598 goto bad; 599 } 600 601 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 602 if (nd_na == NULL) { 603 m_put_rcvif_psref(ifp, &psref); 604 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 605 return; 606 } 607 608 flags = nd_na->nd_na_flags_reserved; 609 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 610 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 611 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 612 613 taddr6 = nd_na->nd_na_target; 614 if (in6_setscope(&taddr6, ifp, NULL)) { 615 m_put_rcvif_psref(ifp, &psref); 616 return; /* XXX: impossible */ 617 } 618 619 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 620 nd6log(LOG_ERR, "invalid target address %s\n", 621 IN6_PRINT(ip6buf, &taddr6)); 622 goto bad; 623 } 624 if (is_solicited && IN6_IS_ADDR_MULTICAST(&daddr6)) { 625 nd6log(LOG_ERR, "a solicited adv is multicasted\n"); 626 goto bad; 627 } 628 629 icmp6len -= sizeof(*nd_na); 630 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 631 if (nd6_options(&ndopts) < 0) { 632 nd6log(LOG_INFO, "invalid ND option, ignored\n"); 633 /* nd6_options have incremented stats */ 634 goto freeit; 635 } 636 637 if (ndopts.nd_opts_tgt_lladdr) { 638 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 639 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 640 } 641 642 ifa = (struct ifaddr *)in6ifa_ifpwithaddr_psref(ifp, &taddr6, &psref_ia); 643 644 /* 645 * Target address matches one of my interface address. 646 * 647 * If my address is tentative, this means that there's somebody 648 * already using the same address as mine. This indicates DAD failure. 649 * This is defined in RFC 2462. 650 * 651 * Otherwise, process as defined in RFC 2461. 652 */ 653 if (ifa 654 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 655 nd6_dad_na_input(ifa); 656 ifa_release(ifa, &psref_ia); 657 ifa = NULL; 658 goto freeit; 659 } 660 661 /* Just for safety, maybe unnecessary. */ 662 if (ifa) { 663 log(LOG_ERR, 664 "nd6_na_input: duplicate IP6 address %s\n", 665 IN6_PRINT(ip6buf, &taddr6)); 666 ifa_release(ifa, &psref_ia); 667 ifa = NULL; 668 goto freeit; 669 } 670 671 /* 672 * Make sure the source address is from a neighbor's address. 673 */ 674 sockaddr_in6_init(&ssin6, &saddr6, 0, 0, 0); 675 if (nd6_is_addr_neighbor(&ssin6, ifp) == 0) { 676 nd6log(LOG_INFO, "ND packet from non-neighbor %s on %s\n", 677 IN6_PRINT(ip6buf, &saddr6), if_name(ifp)); 678 goto bad; 679 } 680 681 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 682 nd6log(LOG_INFO, "lladdrlen mismatch for %s " 683 "(if %d, NA packet %d)\n", IN6_PRINT(ip6buf, &taddr6), 684 ifp->if_addrlen, lladdrlen - 2); 685 goto bad; 686 } 687 688 /* 689 * If no neighbor cache entry is found, NA SHOULD silently be 690 * discarded. 691 */ 692 ln = nd6_lookup(&taddr6, ifp, true); 693 if (ln == NULL) 694 goto freeit; 695 696 rt_announce = 0; 697 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 698 /* 699 * If the link-layer has address, and no lladdr option came, 700 * discard the packet. 701 */ 702 if (ifp->if_addrlen && !lladdr) 703 goto freeit; 704 705 /* 706 * Record link-layer address, and update the state. 707 */ 708 memcpy(&ln->ll_addr, lladdr, ifp->if_addrlen); 709 ln->la_flags |= LLE_VALID; 710 rt_announce = 1; 711 if (is_solicited) { 712 ln->ln_state = ND6_LLINFO_REACHABLE; 713 ln->ln_byhint = 0; 714 if (!ND6_LLINFO_PERMANENT(ln)) { 715 nd6_llinfo_settimer(ln, 716 ND_IFINFO(ln->lle_tbl->llt_ifp)->reachable * hz); 717 } 718 } else { 719 ln->ln_state = ND6_LLINFO_STALE; 720 nd6_llinfo_settimer(ln, nd6_gctimer * hz); 721 } 722 if ((ln->ln_router = is_router) != 0) { 723 /* 724 * This means a router's state has changed from 725 * non-reachable to probably reachable, and might 726 * affect the status of associated prefixes.. 727 */ 728 checklink = true; 729 } 730 } else { 731 int llchange; 732 733 /* 734 * Check if the link-layer address has changed or not. 735 */ 736 if (lladdr == NULL) 737 llchange = 0; 738 else { 739 if (ln->la_flags & LLE_VALID) { 740 if (memcmp(lladdr, &ln->ll_addr, ifp->if_addrlen)) 741 llchange = rt_announce = 1; 742 else 743 llchange = 0; 744 } else 745 llchange = rt_announce = 1; 746 } 747 748 /* 749 * This is VERY complex. Look at it with care. 750 * 751 * override solicit lladdr llchange action 752 * (L: record lladdr) 753 * 754 * 0 0 n -- (2c) 755 * 0 0 y n (2b) L 756 * 0 0 y y (1) REACHABLE->STALE 757 * 0 1 n -- (2c) *->REACHABLE 758 * 0 1 y n (2b) L *->REACHABLE 759 * 0 1 y y (1) REACHABLE->STALE 760 * 1 0 n -- (2a) 761 * 1 0 y n (2a) L 762 * 1 0 y y (2a) L *->STALE 763 * 1 1 n -- (2a) *->REACHABLE 764 * 1 1 y n (2a) L *->REACHABLE 765 * 1 1 y y (2a) L *->REACHABLE 766 */ 767 if (!is_override && lladdr != NULL && llchange) { /* (1) */ 768 /* 769 * If state is REACHABLE, make it STALE. 770 * no other updates should be done. 771 */ 772 if (ln->ln_state == ND6_LLINFO_REACHABLE) { 773 ln->ln_state = ND6_LLINFO_STALE; 774 nd6_llinfo_settimer(ln, nd6_gctimer * hz); 775 } 776 goto freeit; 777 } else if (is_override /* (2a) */ 778 || (!is_override && lladdr != NULL && !llchange) /* (2b) */ 779 || lladdr == NULL) { /* (2c) */ 780 /* 781 * Update link-local address, if any. 782 */ 783 if (lladdr != NULL) { 784 memcpy(&ln->ll_addr, lladdr, ifp->if_addrlen); 785 ln->la_flags |= LLE_VALID; 786 } 787 788 /* 789 * If solicited, make the state REACHABLE. 790 * If not solicited and the link-layer address was 791 * changed, make it STALE. 792 */ 793 if (is_solicited) { 794 ln->ln_state = ND6_LLINFO_REACHABLE; 795 ln->ln_byhint = 0; 796 if (!ND6_LLINFO_PERMANENT(ln)) { 797 nd6_llinfo_settimer(ln, 798 ND_IFINFO(ifp)->reachable * hz); 799 } 800 } else { 801 if (lladdr && llchange) { 802 ln->ln_state = ND6_LLINFO_STALE; 803 nd6_llinfo_settimer(ln, 804 nd6_gctimer * hz); 805 } 806 } 807 } 808 809 if (ln->ln_router && !is_router) { 810 /* 811 * The peer dropped the router flag. 812 * Remove the sender from the Default Router List and 813 * update the Destination Cache entries. 814 */ 815 struct nd_defrouter *dr; 816 const struct in6_addr *in6; 817 818 in6 = &ln->r_l3addr.addr6; 819 820 ND6_WLOCK(); 821 dr = nd6_defrouter_lookup(in6, ln->lle_tbl->llt_ifp); 822 if (dr) 823 nd6_defrtrlist_del(dr, NULL); 824 else if (!ip6_forwarding) { 825 /* 826 * Even if the neighbor is not in the default 827 * router list, the neighbor may be used 828 * as a next hop for some destinations 829 * (e.g. redirect case). So we must 830 * call nd6_rt_flush explicitly. 831 */ 832 nd6_rt_flush(&ip6->ip6_src, ln->lle_tbl->llt_ifp); 833 } 834 ND6_UNLOCK(); 835 } 836 ln->ln_router = is_router; 837 } 838 /* 839 * XXX: does this matter? 840 * rt->rt_flags &= ~RTF_REJECT; 841 */ 842 ln->ln_asked = 0; 843 nd6_llinfo_release_pkts(ln, ifp); 844 /* FIXME */ 845 #if 0 846 if (rt_announce) /* tell user process about any new lladdr */ 847 rt_newmsg(RTM_CHANGE, rt); 848 #endif 849 850 freeit: 851 if (ln != NULL) 852 LLE_WUNLOCK(ln); 853 854 if (checklink) { 855 ND6_WLOCK(); 856 nd6_pfxlist_onlink_check(); 857 ND6_UNLOCK(); 858 } 859 860 m_put_rcvif_psref(ifp, &psref); 861 m_freem(m); 862 return; 863 864 bad: 865 if (ln != NULL) 866 LLE_WUNLOCK(ln); 867 868 ICMP6_STATINC(ICMP6_STAT_BADNA); 869 m_put_rcvif_psref(ifp, &psref); 870 m_freem(m); 871 } 872 873 /* 874 * Neighbor advertisement output handling. 875 * 876 * Based on RFC 2461 877 * 878 * the following items are not implemented yet: 879 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 880 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 881 */ 882 void 883 nd6_na_output( 884 struct ifnet *ifp, 885 const struct in6_addr *daddr6_0, 886 const struct in6_addr *taddr6, 887 u_long flags, 888 int tlladdr, /* 1 if include target link-layer address */ 889 const struct sockaddr *sdl0) /* sockaddr_dl (= proxy NA) or NULL */ 890 { 891 struct mbuf *m; 892 struct ip6_hdr *ip6; 893 struct nd_neighbor_advert *nd_na; 894 struct ip6_moptions im6o; 895 struct sockaddr *dst; 896 union { 897 struct sockaddr dst; 898 struct sockaddr_in6 dst6; 899 } u; 900 struct in6_addr daddr6; 901 int icmp6len, maxlen, error; 902 const void *mac; 903 struct route ro; 904 905 mac = NULL; 906 memset(&ro, 0, sizeof(ro)); 907 908 daddr6 = *daddr6_0; /* make a local copy for modification */ 909 910 /* estimate the size of message */ 911 maxlen = sizeof(*ip6) + sizeof(*nd_na); 912 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 913 #ifdef DIAGNOSTIC 914 if (max_linkhdr + maxlen >= MCLBYTES) { 915 printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES " 916 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES); 917 panic("nd6_na_output: insufficient MCLBYTES"); 918 /* NOTREACHED */ 919 } 920 #endif 921 922 MGETHDR(m, M_DONTWAIT, MT_DATA); 923 if (m && max_linkhdr + maxlen >= MHLEN) { 924 MCLGET(m, M_DONTWAIT); 925 if ((m->m_flags & M_EXT) == 0) { 926 m_free(m); 927 m = NULL; 928 } 929 } 930 if (m == NULL) 931 return; 932 m_reset_rcvif(m); 933 934 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 935 m->m_flags |= M_MCAST; 936 im6o.im6o_multicast_if_index = if_get_index(ifp); 937 im6o.im6o_multicast_hlim = 255; 938 im6o.im6o_multicast_loop = 0; 939 } 940 941 icmp6len = sizeof(*nd_na); 942 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 943 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 944 945 /* fill neighbor advertisement packet */ 946 ip6 = mtod(m, struct ip6_hdr *); 947 ip6->ip6_flow = 0; 948 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 949 ip6->ip6_vfc |= IPV6_VERSION; 950 ip6->ip6_nxt = IPPROTO_ICMPV6; 951 ip6->ip6_hlim = 255; 952 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 953 /* reply to DAD */ 954 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 955 daddr6.s6_addr16[1] = 0; 956 daddr6.s6_addr32[1] = 0; 957 daddr6.s6_addr32[2] = 0; 958 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 959 if (in6_setscope(&daddr6, ifp, NULL)) 960 goto bad; 961 962 flags &= ~ND_NA_FLAG_SOLICITED; 963 } 964 ip6->ip6_dst = daddr6; 965 sockaddr_in6_init(&u.dst6, &daddr6, 0, 0, 0); 966 dst = &u.dst; 967 if (rtcache_setdst(&ro, dst) != 0) 968 goto bad; 969 970 /* 971 * Select a source whose scope is the same as that of the dest. 972 */ 973 error = in6_selectsrc(satosin6(dst), NULL, NULL, &ro, NULL, NULL, NULL, 974 &ip6->ip6_src); 975 if (error != 0) { 976 char ip6buf[INET6_ADDRSTRLEN]; 977 nd6log(LOG_DEBUG, "source can't be " 978 "determined: dst=%s, error=%d\n", 979 IN6_PRINT(ip6buf, &satocsin6(dst)->sin6_addr), error); 980 goto bad; 981 } 982 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 983 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 984 nd_na->nd_na_code = 0; 985 nd_na->nd_na_target = *taddr6; 986 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 987 988 /* 989 * "tlladdr" indicates NS's condition for adding tlladdr or not. 990 * see nd6_ns_input() for details. 991 * Basically, if NS packet is sent to unicast/anycast addr, 992 * target lladdr option SHOULD NOT be included. 993 */ 994 if (tlladdr) { 995 /* 996 * sdl0 != NULL indicates proxy NA. If we do proxy, use 997 * lladdr in sdl0. If we are not proxying (sending NA for 998 * my address) use lladdr configured for the interface. 999 */ 1000 if (sdl0 == NULL) 1001 mac = nd6_ifptomac(ifp); 1002 else if (sdl0->sa_family == AF_LINK) { 1003 const struct sockaddr_dl *sdl; 1004 sdl = satocsdl(sdl0); 1005 if (sdl->sdl_alen == ifp->if_addrlen) 1006 mac = CLLADDR(sdl); 1007 } 1008 } 1009 if (tlladdr && mac) { 1010 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1011 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1012 1013 /* roundup to 8 bytes alignment! */ 1014 optlen = (optlen + 7) & ~7; 1015 1016 m->m_pkthdr.len += optlen; 1017 m->m_len += optlen; 1018 icmp6len += optlen; 1019 memset((void *)nd_opt, 0, optlen); 1020 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1021 nd_opt->nd_opt_len = optlen >> 3; 1022 memcpy((void *)(nd_opt + 1), mac, ifp->if_addrlen); 1023 } else 1024 flags &= ~ND_NA_FLAG_OVERRIDE; 1025 1026 ip6->ip6_plen = htons((u_int16_t)icmp6len); 1027 nd_na->nd_na_flags_reserved = flags; 1028 nd_na->nd_na_cksum = 0; 1029 nd_na->nd_na_cksum = 1030 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1031 1032 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1033 1034 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1035 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1036 ICMP6_STATINC(ICMP6_STAT_OUTHIST + ND_NEIGHBOR_ADVERT); 1037 1038 rtcache_free(&ro); 1039 return; 1040 1041 bad: 1042 rtcache_free(&ro); 1043 m_freem(m); 1044 return; 1045 } 1046 1047 const void * 1048 nd6_ifptomac(const struct ifnet *ifp) 1049 { 1050 switch (ifp->if_type) { 1051 case IFT_ARCNET: 1052 case IFT_ETHER: 1053 case IFT_FDDI: 1054 case IFT_IEEE1394: 1055 case IFT_PROPVIRTUAL: 1056 case IFT_CARP: 1057 case IFT_L2VLAN: 1058 case IFT_IEEE80211: 1059 return CLLADDR(ifp->if_sadl); 1060 default: 1061 return NULL; 1062 } 1063 } 1064 1065 TAILQ_HEAD(dadq_head, dadq); 1066 struct dadq { 1067 TAILQ_ENTRY(dadq) dad_list; 1068 struct ifaddr *dad_ifa; 1069 int dad_count; /* max NS to send */ 1070 int dad_ns_tcount; /* # of trials to send NS */ 1071 int dad_ns_ocount; /* NS sent so far */ 1072 int dad_ns_icount; 1073 int dad_na_icount; 1074 struct callout dad_timer_ch; 1075 }; 1076 1077 static struct dadq_head dadq; 1078 static int dad_init = 0; 1079 static kmutex_t nd6_dad_lock; 1080 1081 static struct dadq * 1082 nd6_dad_find(struct ifaddr *ifa) 1083 { 1084 struct dadq *dp; 1085 1086 KASSERT(mutex_owned(&nd6_dad_lock)); 1087 1088 TAILQ_FOREACH(dp, &dadq, dad_list) { 1089 if (dp->dad_ifa == ifa) 1090 return dp; 1091 } 1092 return NULL; 1093 } 1094 1095 static void 1096 nd6_dad_starttimer(struct dadq *dp, int ticks) 1097 { 1098 1099 callout_reset(&dp->dad_timer_ch, ticks, 1100 (void (*)(void *))nd6_dad_timer, (void *)dp->dad_ifa); 1101 } 1102 1103 static void 1104 nd6_dad_stoptimer(struct dadq *dp) 1105 { 1106 1107 #ifdef NET_MPSAFE 1108 callout_halt(&dp->dad_timer_ch, NULL); 1109 #else 1110 callout_halt(&dp->dad_timer_ch, softnet_lock); 1111 #endif 1112 } 1113 1114 /* 1115 * Start Duplicate Address Detection (DAD) for specified interface address. 1116 * 1117 * Note that callout is used when xtick > 0 and not when xtick == 0. 1118 * 1119 * xtick: minimum delay ticks for IFF_UP event 1120 */ 1121 void 1122 nd6_dad_start(struct ifaddr *ifa, int xtick) 1123 { 1124 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1125 struct dadq *dp; 1126 char ip6buf[INET6_ADDRSTRLEN]; 1127 1128 if (!dad_init) { 1129 TAILQ_INIT(&dadq); 1130 mutex_init(&nd6_dad_lock, MUTEX_DEFAULT, IPL_NONE); 1131 dad_init++; 1132 } 1133 1134 /* 1135 * If we don't need DAD, don't do it. 1136 * There are several cases: 1137 * - DAD is disabled (ip6_dad_count == 0) 1138 * - the interface address is anycast 1139 */ 1140 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1141 log(LOG_DEBUG, 1142 "nd6_dad_start: called with non-tentative address " 1143 "%s(%s)\n", 1144 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1145 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1146 return; 1147 } 1148 if (ia->ia6_flags & IN6_IFF_ANYCAST || !ip6_dad_count) { 1149 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1150 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1151 return; 1152 } 1153 KASSERT(ifa->ifa_ifp != NULL); 1154 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1155 return; 1156 1157 dp = kmem_intr_alloc(sizeof(*dp), KM_NOSLEEP); 1158 1159 mutex_enter(&nd6_dad_lock); 1160 if (nd6_dad_find(ifa) != NULL) { 1161 mutex_exit(&nd6_dad_lock); 1162 /* DAD already in progress */ 1163 if (dp != NULL) 1164 kmem_intr_free(dp, sizeof(*dp)); 1165 return; 1166 } 1167 1168 if (dp == NULL) { 1169 mutex_exit(&nd6_dad_lock); 1170 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1171 "%s(%s)\n", 1172 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1173 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1174 return; 1175 } 1176 1177 /* 1178 * Send NS packet for DAD, ip6_dad_count times. 1179 * Note that we must delay the first transmission, if this is the 1180 * first packet to be sent from the interface after interface 1181 * (re)initialization. 1182 */ 1183 callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE); 1184 dp->dad_ifa = ifa; 1185 ifaref(ifa); /* just for safety */ 1186 dp->dad_count = ip6_dad_count; 1187 dp->dad_ns_icount = dp->dad_na_icount = 0; 1188 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1189 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); 1190 1191 nd6log(LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1192 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr)); 1193 1194 if (xtick == 0) { 1195 nd6_dad_ns_output(dp, ifa); 1196 nd6_dad_starttimer(dp, 1197 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1198 } else 1199 nd6_dad_starttimer(dp, xtick); 1200 mutex_exit(&nd6_dad_lock); 1201 } 1202 1203 /* 1204 * terminate DAD unconditionally. used for address removals. 1205 */ 1206 void 1207 nd6_dad_stop(struct ifaddr *ifa) 1208 { 1209 struct dadq *dp; 1210 1211 if (!dad_init) 1212 return; 1213 1214 mutex_enter(&nd6_dad_lock); 1215 dp = nd6_dad_find(ifa); 1216 if (dp == NULL) { 1217 mutex_exit(&nd6_dad_lock); 1218 /* DAD wasn't started yet */ 1219 return; 1220 } 1221 1222 /* Prevent the timer from running anymore. */ 1223 TAILQ_REMOVE(&dadq, dp, dad_list); 1224 mutex_exit(&nd6_dad_lock); 1225 1226 nd6_dad_stoptimer(dp); 1227 1228 kmem_intr_free(dp, sizeof(*dp)); 1229 ifafree(ifa); 1230 } 1231 1232 static void 1233 nd6_dad_timer(struct ifaddr *ifa) 1234 { 1235 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1236 struct dadq *dp; 1237 int duplicate = 0; 1238 char ip6buf[INET6_ADDRSTRLEN]; 1239 bool need_free = false; 1240 1241 #ifndef NET_MPSAFE 1242 mutex_enter(softnet_lock); 1243 KERNEL_LOCK(1, NULL); 1244 #endif 1245 mutex_enter(&nd6_dad_lock); 1246 1247 /* Sanity check */ 1248 if (ia == NULL) { 1249 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n"); 1250 goto done; 1251 } 1252 dp = nd6_dad_find(ifa); 1253 if (dp == NULL) { 1254 /* DAD seems to be stopping, so do nothing. */ 1255 goto done; 1256 } 1257 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1258 log(LOG_ERR, "nd6_dad_timer: called with duplicate address " 1259 "%s(%s)\n", 1260 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1261 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1262 goto done; 1263 } 1264 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1265 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1266 "%s(%s)\n", 1267 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1268 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1269 goto done; 1270 } 1271 1272 /* timeouted with IFF_{RUNNING,UP} check */ 1273 if (dp->dad_ns_tcount > dad_maxtry) { 1274 nd6log(LOG_INFO, "%s: could not run DAD, driver problem?\n", 1275 if_name(ifa->ifa_ifp)); 1276 1277 TAILQ_REMOVE(&dadq, dp, dad_list); 1278 need_free = true; 1279 goto done; 1280 } 1281 1282 /* Need more checks? */ 1283 if (dp->dad_ns_ocount < dp->dad_count) { 1284 /* 1285 * We have more NS to go. Send NS packet for DAD. 1286 */ 1287 nd6_dad_ns_output(dp, ifa); 1288 nd6_dad_starttimer(dp, 1289 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1290 } else { 1291 /* 1292 * We have transmitted sufficient number of DAD packets. 1293 * See what we've got. 1294 */ 1295 if (dp->dad_na_icount) { 1296 /* 1297 * the check is in nd6_dad_na_input(), 1298 * but just in case 1299 */ 1300 duplicate++; 1301 } 1302 1303 if (dp->dad_ns_icount) { 1304 /* We've seen NS, means DAD has failed. */ 1305 duplicate++; 1306 } 1307 1308 if (duplicate) { 1309 /* (*dp) will be freed in nd6_dad_duplicated() */ 1310 dp = NULL; 1311 } else { 1312 /* 1313 * We are done with DAD. No NA came, no NS came. 1314 * No duplicate address found. 1315 */ 1316 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1317 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1318 1319 nd6log(LOG_DEBUG, 1320 "%s: DAD complete for %s - no duplicates found\n", 1321 if_name(ifa->ifa_ifp), 1322 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr)); 1323 1324 TAILQ_REMOVE(&dadq, dp, dad_list); 1325 need_free = true; 1326 } 1327 } 1328 done: 1329 mutex_exit(&nd6_dad_lock); 1330 1331 if (need_free) { 1332 kmem_intr_free(dp, sizeof(*dp)); 1333 ifafree(ifa); 1334 ifa = NULL; 1335 } 1336 1337 if (duplicate) 1338 nd6_dad_duplicated(ifa); 1339 1340 #ifndef NET_MPSAFE 1341 KERNEL_UNLOCK_ONE(NULL); 1342 mutex_exit(softnet_lock); 1343 #endif 1344 } 1345 1346 static void 1347 nd6_dad_duplicated(struct ifaddr *ifa) 1348 { 1349 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1350 struct ifnet *ifp; 1351 struct dadq *dp; 1352 char ip6buf[INET6_ADDRSTRLEN]; 1353 1354 mutex_enter(&nd6_dad_lock); 1355 dp = nd6_dad_find(ifa); 1356 if (dp == NULL) { 1357 mutex_exit(&nd6_dad_lock); 1358 /* DAD seems to be stopping, so do nothing. */ 1359 return; 1360 } 1361 1362 ifp = ifa->ifa_ifp; 1363 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1364 "NS in/out=%d/%d, NA in=%d\n", 1365 if_name(ifp), IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1366 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount); 1367 1368 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1369 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1370 1371 /* We are done with DAD, with duplicated address found. (failure) */ 1372 nd6_dad_stoptimer(dp); 1373 1374 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1375 if_name(ifp), IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr)); 1376 log(LOG_ERR, "%s: manual intervention required\n", 1377 if_name(ifp)); 1378 1379 /* Inform the routing socket that DAD has completed */ 1380 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1381 1382 /* 1383 * If the address is a link-local address formed from an interface 1384 * identifier based on the hardware address which is supposed to be 1385 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1386 * operation on the interface SHOULD be disabled. 1387 * [rfc2462bis-03 Section 5.4.5] 1388 */ 1389 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1390 struct in6_addr in6; 1391 1392 /* 1393 * To avoid over-reaction, we only apply this logic when we are 1394 * very sure that hardware addresses are supposed to be unique. 1395 */ 1396 switch (ifp->if_type) { 1397 case IFT_ETHER: 1398 case IFT_FDDI: 1399 case IFT_ATM: 1400 case IFT_IEEE1394: 1401 #ifdef IFT_IEEE80211 1402 case IFT_IEEE80211: 1403 #endif 1404 in6 = ia->ia_addr.sin6_addr; 1405 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1406 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1407 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1408 log(LOG_ERR, "%s: possible hardware address " 1409 "duplication detected, disable IPv6\n", 1410 if_name(ifp)); 1411 } 1412 break; 1413 } 1414 } 1415 1416 TAILQ_REMOVE(&dadq, dp, dad_list); 1417 mutex_exit(&nd6_dad_lock); 1418 1419 kmem_intr_free(dp, sizeof(*dp)); 1420 ifafree(ifa); 1421 } 1422 1423 static void 1424 nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa) 1425 { 1426 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1427 struct ifnet *ifp = ifa->ifa_ifp; 1428 1429 dp->dad_ns_tcount++; 1430 if ((ifp->if_flags & IFF_UP) == 0) { 1431 #if 0 1432 printf("%s: interface down?\n", if_name(ifp)); 1433 #endif 1434 return; 1435 } 1436 if ((ifp->if_flags & IFF_RUNNING) == 0) { 1437 #if 0 1438 printf("%s: interface not running?\n", if_name(ifp)); 1439 #endif 1440 return; 1441 } 1442 1443 dp->dad_ns_tcount = 0; 1444 dp->dad_ns_ocount++; 1445 nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1); 1446 } 1447 1448 static void 1449 nd6_dad_ns_input(struct ifaddr *ifa) 1450 { 1451 struct in6_ifaddr *ia; 1452 const struct in6_addr *taddr6; 1453 struct dadq *dp; 1454 int duplicate; 1455 1456 if (ifa == NULL) 1457 panic("ifa == NULL in nd6_dad_ns_input"); 1458 1459 ia = (struct in6_ifaddr *)ifa; 1460 taddr6 = &ia->ia_addr.sin6_addr; 1461 duplicate = 0; 1462 1463 mutex_enter(&nd6_dad_lock); 1464 dp = nd6_dad_find(ifa); 1465 1466 /* Quickhack - completely ignore DAD NS packets */ 1467 if (dad_ignore_ns) { 1468 char ip6buf[INET6_ADDRSTRLEN]; 1469 nd6log(LOG_INFO, "ignoring DAD NS packet for " 1470 "address %s(%s)\n", IN6_PRINT(ip6buf, taddr6), 1471 if_name(ifa->ifa_ifp)); 1472 return; 1473 } 1474 1475 /* 1476 * if I'm yet to start DAD, someone else started using this address 1477 * first. I have a duplicate and you win. 1478 */ 1479 if (dp == NULL || dp->dad_ns_ocount == 0) 1480 duplicate++; 1481 1482 /* XXX more checks for loopback situation - see nd6_dad_timer too */ 1483 1484 if (duplicate) { 1485 dp = NULL; /* will be freed in nd6_dad_duplicated() */ 1486 mutex_exit(&nd6_dad_lock); 1487 nd6_dad_duplicated(ifa); 1488 } else { 1489 /* 1490 * not sure if I got a duplicate. 1491 * increment ns count and see what happens. 1492 */ 1493 if (dp) 1494 dp->dad_ns_icount++; 1495 mutex_exit(&nd6_dad_lock); 1496 } 1497 } 1498 1499 static void 1500 nd6_dad_na_input(struct ifaddr *ifa) 1501 { 1502 struct dadq *dp; 1503 1504 if (ifa == NULL) 1505 panic("ifa == NULL in nd6_dad_na_input"); 1506 1507 mutex_enter(&nd6_dad_lock); 1508 dp = nd6_dad_find(ifa); 1509 if (dp) 1510 dp->dad_na_icount++; 1511 mutex_exit(&nd6_dad_lock); 1512 1513 /* remove the address. */ 1514 nd6_dad_duplicated(ifa); 1515 } 1516
Indexes created Sat Sep 27 22:09:54 GMT 2025