nd6_nbr.c revision 1.138.6.3
1 /* $NetBSD: nd6_nbr.c,v 1.138.6.3 2018/02/02 12:55:08 martin 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 1.138.6.3 2018/02/02 12:55:08 martin 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_destroytimer(struct dadq *); 83 static void nd6_dad_timer(struct dadq *); 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 KASSERTMSG(max_linkhdr + maxlen < MCLBYTES, 398 "max_linkhdr + maxlen >= MCLBYTES (%d + %d >= %d)", 399 max_linkhdr, maxlen, MCLBYTES); 400 401 MGETHDR(m, M_DONTWAIT, MT_DATA); 402 if (m && max_linkhdr + maxlen >= MHLEN) { 403 MCLGET(m, M_DONTWAIT); 404 if ((m->m_flags & M_EXT) == 0) { 405 m_free(m); 406 m = NULL; 407 } 408 } 409 if (m == NULL) 410 return; 411 m_reset_rcvif(m); 412 413 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 414 m->m_flags |= M_MCAST; 415 im6o.im6o_multicast_if_index = if_get_index(ifp); 416 im6o.im6o_multicast_hlim = 255; 417 im6o.im6o_multicast_loop = 0; 418 } 419 420 icmp6len = sizeof(*nd_ns); 421 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 422 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 423 424 /* fill neighbor solicitation packet */ 425 ip6 = mtod(m, struct ip6_hdr *); 426 ip6->ip6_flow = 0; 427 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 428 ip6->ip6_vfc |= IPV6_VERSION; 429 /* ip6->ip6_plen will be set later */ 430 ip6->ip6_nxt = IPPROTO_ICMPV6; 431 ip6->ip6_hlim = 255; 432 if (daddr6) 433 ip6->ip6_dst = *daddr6; 434 else { 435 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 436 ip6->ip6_dst.s6_addr16[1] = 0; 437 ip6->ip6_dst.s6_addr32[1] = 0; 438 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 439 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 440 ip6->ip6_dst.s6_addr8[12] = 0xff; 441 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 442 goto bad; 443 } 444 if (!dad) { 445 int s; 446 /* 447 * RFC2461 7.2.2: 448 * "If the source address of the packet prompting the 449 * solicitation is the same as one of the addresses assigned 450 * to the outgoing interface, that address SHOULD be placed 451 * in the IP Source Address of the outgoing solicitation. 452 * Otherwise, any one of the addresses assigned to the 453 * interface should be used." 454 * 455 * We use the source address for the prompting packet 456 * (hsrc), if: 457 * - hsrc is given from the caller (by giving "ln"), and 458 * - hsrc belongs to the outgoing interface. 459 * Otherwise, we perform the source address selection as usual. 460 */ 461 s = pserialize_read_enter(); 462 if (hsrc && in6ifa_ifpwithaddr(ifp, hsrc)) 463 src = hsrc; 464 else { 465 int error; 466 struct sockaddr_in6 dst_sa; 467 468 sockaddr_in6_init(&dst_sa, &ip6->ip6_dst, 0, 0, 0); 469 470 error = in6_selectsrc(&dst_sa, NULL, 471 NULL, &ro, NULL, NULL, NULL, &src_in); 472 if (error != 0) { 473 char ip6buf[INET6_ADDRSTRLEN]; 474 nd6log(LOG_DEBUG, "source can't be " 475 "determined: dst=%s, error=%d\n", 476 IN6_PRINT(ip6buf, &dst_sa.sin6_addr), 477 error); 478 pserialize_read_exit(s); 479 goto bad; 480 } 481 src = &src_in; 482 } 483 pserialize_read_exit(s); 484 } else { 485 /* 486 * Source address for DAD packet must always be IPv6 487 * unspecified address. (0::0) 488 * We actually don't have to 0-clear the address (we did it 489 * above), but we do so here explicitly to make the intention 490 * clearer. 491 */ 492 memset(&src_in, 0, sizeof(src_in)); 493 src = &src_in; 494 } 495 ip6->ip6_src = *src; 496 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 497 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 498 nd_ns->nd_ns_code = 0; 499 nd_ns->nd_ns_reserved = 0; 500 nd_ns->nd_ns_target = *taddr6; 501 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 502 503 /* 504 * Add source link-layer address option. 505 * 506 * spec implementation 507 * --- --- 508 * DAD packet MUST NOT do not add the option 509 * there's no link layer address: 510 * impossible do not add the option 511 * there's link layer address: 512 * Multicast NS MUST add one add the option 513 * Unicast NS SHOULD add one add the option 514 */ 515 if (!dad && (mac = nd6_ifptomac(ifp))) { 516 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 517 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 518 /* 8 byte alignments... */ 519 optlen = (optlen + 7) & ~7; 520 521 m->m_pkthdr.len += optlen; 522 m->m_len += optlen; 523 icmp6len += optlen; 524 memset((void *)nd_opt, 0, optlen); 525 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 526 nd_opt->nd_opt_len = optlen >> 3; 527 memcpy((void *)(nd_opt + 1), mac, ifp->if_addrlen); 528 } 529 530 ip6->ip6_plen = htons((u_int16_t)icmp6len); 531 nd_ns->nd_ns_cksum = 0; 532 nd_ns->nd_ns_cksum = 533 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 534 535 ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL, NULL); 536 icmp6_ifstat_inc(ifp, ifs6_out_msg); 537 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 538 ICMP6_STATINC(ICMP6_STAT_OUTHIST + ND_NEIGHBOR_SOLICIT); 539 540 rtcache_free(&ro); 541 return; 542 543 bad: 544 rtcache_free(&ro); 545 m_freem(m); 546 return; 547 } 548 549 /* 550 * Neighbor advertisement input handling. 551 * 552 * Based on RFC 2461 553 * Based on RFC 2462 (duplicate address detection) 554 * 555 * the following items are not implemented yet: 556 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 557 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 558 */ 559 void 560 nd6_na_input(struct mbuf *m, int off, int icmp6len) 561 { 562 struct ifnet *ifp; 563 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 564 struct nd_neighbor_advert *nd_na; 565 struct in6_addr saddr6 = ip6->ip6_src; 566 struct in6_addr daddr6 = ip6->ip6_dst; 567 struct in6_addr taddr6; 568 int flags; 569 int is_router; 570 int is_solicited; 571 int is_override; 572 char *lladdr = NULL; 573 int lladdrlen = 0; 574 struct ifaddr *ifa; 575 struct llentry *ln = NULL; 576 union nd_opts ndopts; 577 struct sockaddr_in6 ssin6; 578 int rt_announce; 579 bool checklink = false; 580 struct psref psref; 581 struct psref psref_ia; 582 char ip6buf[INET6_ADDRSTRLEN], ip6buf2[INET6_ADDRSTRLEN]; 583 584 ifp = m_get_rcvif_psref(m, &psref); 585 if (ifp == NULL) 586 goto freeit; 587 588 if (ip6->ip6_hlim != 255) { 589 nd6log(LOG_ERR, 590 "invalid hlim (%d) from %s to %s on %s\n", 591 ip6->ip6_hlim, IN6_PRINT(ip6buf, &ip6->ip6_src), 592 IN6_PRINT(ip6buf2, &ip6->ip6_dst), if_name(ifp)); 593 goto bad; 594 } 595 596 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 597 if (nd_na == NULL) { 598 m_put_rcvif_psref(ifp, &psref); 599 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 600 return; 601 } 602 603 flags = nd_na->nd_na_flags_reserved; 604 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 605 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 606 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 607 608 taddr6 = nd_na->nd_na_target; 609 if (in6_setscope(&taddr6, ifp, NULL)) { 610 goto bad; 611 } 612 613 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 614 nd6log(LOG_ERR, "invalid target address %s\n", 615 IN6_PRINT(ip6buf, &taddr6)); 616 goto bad; 617 } 618 if (is_solicited && IN6_IS_ADDR_MULTICAST(&daddr6)) { 619 nd6log(LOG_ERR, "a solicited adv is multicasted\n"); 620 goto bad; 621 } 622 623 icmp6len -= sizeof(*nd_na); 624 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 625 if (nd6_options(&ndopts) < 0) { 626 nd6log(LOG_INFO, "invalid ND option, ignored\n"); 627 /* nd6_options have incremented stats */ 628 goto freeit; 629 } 630 631 if (ndopts.nd_opts_tgt_lladdr) { 632 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 633 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 634 } 635 636 ifa = (struct ifaddr *)in6ifa_ifpwithaddr_psref(ifp, &taddr6, &psref_ia); 637 638 /* 639 * Target address matches one of my interface address. 640 * 641 * If my address is tentative, this means that there's somebody 642 * already using the same address as mine. This indicates DAD failure. 643 * This is defined in RFC 2462. 644 * 645 * Otherwise, process as defined in RFC 2461. 646 */ 647 if (ifa 648 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 649 nd6_dad_na_input(ifa); 650 ifa_release(ifa, &psref_ia); 651 ifa = NULL; 652 goto freeit; 653 } 654 655 /* Just for safety, maybe unnecessary. */ 656 if (ifa) { 657 log(LOG_ERR, 658 "nd6_na_input: duplicate IP6 address %s\n", 659 IN6_PRINT(ip6buf, &taddr6)); 660 ifa_release(ifa, &psref_ia); 661 ifa = NULL; 662 goto freeit; 663 } 664 665 /* 666 * Make sure the source address is from a neighbor's address. 667 */ 668 sockaddr_in6_init(&ssin6, &saddr6, 0, 0, 0); 669 if (nd6_is_addr_neighbor(&ssin6, ifp) == 0) { 670 nd6log(LOG_INFO, "ND packet from non-neighbor %s on %s\n", 671 IN6_PRINT(ip6buf, &saddr6), if_name(ifp)); 672 goto bad; 673 } 674 675 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 676 nd6log(LOG_INFO, "lladdrlen mismatch for %s " 677 "(if %d, NA packet %d)\n", IN6_PRINT(ip6buf, &taddr6), 678 ifp->if_addrlen, lladdrlen - 2); 679 goto bad; 680 } 681 682 /* 683 * If no neighbor cache entry is found, NA SHOULD silently be 684 * discarded. 685 */ 686 ln = nd6_lookup(&taddr6, ifp, true); 687 if (ln == NULL) 688 goto freeit; 689 690 rt_announce = 0; 691 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 692 /* 693 * If the link-layer has address, and no lladdr option came, 694 * discard the packet. 695 */ 696 if (ifp->if_addrlen && !lladdr) 697 goto freeit; 698 699 /* 700 * Record link-layer address, and update the state. 701 */ 702 memcpy(&ln->ll_addr, lladdr, ifp->if_addrlen); 703 ln->la_flags |= LLE_VALID; 704 rt_announce = 1; 705 if (is_solicited) { 706 ln->ln_state = ND6_LLINFO_REACHABLE; 707 ln->ln_byhint = 0; 708 if (!ND6_LLINFO_PERMANENT(ln)) { 709 nd6_llinfo_settimer(ln, 710 ND_IFINFO(ln->lle_tbl->llt_ifp)->reachable * hz); 711 } 712 } else { 713 ln->ln_state = ND6_LLINFO_STALE; 714 nd6_llinfo_settimer(ln, nd6_gctimer * hz); 715 } 716 if ((ln->ln_router = is_router) != 0) { 717 /* 718 * This means a router's state has changed from 719 * non-reachable to probably reachable, and might 720 * affect the status of associated prefixes.. 721 */ 722 checklink = true; 723 } 724 } else { 725 int llchange; 726 727 /* 728 * Check if the link-layer address has changed or not. 729 */ 730 if (lladdr == NULL) 731 llchange = 0; 732 else { 733 if (ln->la_flags & LLE_VALID) { 734 if (memcmp(lladdr, &ln->ll_addr, ifp->if_addrlen)) 735 llchange = rt_announce = 1; 736 else 737 llchange = 0; 738 } else 739 llchange = rt_announce = 1; 740 } 741 742 /* 743 * This is VERY complex. Look at it with care. 744 * 745 * override solicit lladdr llchange action 746 * (L: record lladdr) 747 * 748 * 0 0 n -- (2c) 749 * 0 0 y n (2b) L 750 * 0 0 y y (1) REACHABLE->STALE 751 * 0 1 n -- (2c) *->REACHABLE 752 * 0 1 y n (2b) L *->REACHABLE 753 * 0 1 y y (1) REACHABLE->STALE 754 * 1 0 n -- (2a) 755 * 1 0 y n (2a) L 756 * 1 0 y y (2a) L *->STALE 757 * 1 1 n -- (2a) *->REACHABLE 758 * 1 1 y n (2a) L *->REACHABLE 759 * 1 1 y y (2a) L *->REACHABLE 760 */ 761 if (!is_override && lladdr != NULL && llchange) { /* (1) */ 762 /* 763 * If state is REACHABLE, make it STALE. 764 * no other updates should be done. 765 */ 766 if (ln->ln_state == ND6_LLINFO_REACHABLE) { 767 ln->ln_state = ND6_LLINFO_STALE; 768 nd6_llinfo_settimer(ln, nd6_gctimer * hz); 769 } 770 goto freeit; 771 } else if (is_override /* (2a) */ 772 || (!is_override && lladdr != NULL && !llchange) /* (2b) */ 773 || lladdr == NULL) { /* (2c) */ 774 /* 775 * Update link-local address, if any. 776 */ 777 if (lladdr != NULL) { 778 memcpy(&ln->ll_addr, lladdr, ifp->if_addrlen); 779 ln->la_flags |= LLE_VALID; 780 } 781 782 /* 783 * If solicited, make the state REACHABLE. 784 * If not solicited and the link-layer address was 785 * changed, make it STALE. 786 */ 787 if (is_solicited) { 788 ln->ln_state = ND6_LLINFO_REACHABLE; 789 ln->ln_byhint = 0; 790 if (!ND6_LLINFO_PERMANENT(ln)) { 791 nd6_llinfo_settimer(ln, 792 ND_IFINFO(ifp)->reachable * hz); 793 } 794 } else { 795 if (lladdr && llchange) { 796 ln->ln_state = ND6_LLINFO_STALE; 797 nd6_llinfo_settimer(ln, 798 nd6_gctimer * hz); 799 } 800 } 801 } 802 803 if (ln->ln_router && !is_router) { 804 /* 805 * The peer dropped the router flag. 806 * Remove the sender from the Default Router List and 807 * update the Destination Cache entries. 808 */ 809 struct nd_defrouter *dr; 810 const struct in6_addr *in6; 811 812 in6 = &ln->r_l3addr.addr6; 813 814 ND6_WLOCK(); 815 dr = nd6_defrouter_lookup(in6, ln->lle_tbl->llt_ifp); 816 if (dr) 817 nd6_defrtrlist_del(dr, NULL); 818 else if (!ip6_forwarding) { 819 /* 820 * Even if the neighbor is not in the default 821 * router list, the neighbor may be used 822 * as a next hop for some destinations 823 * (e.g. redirect case). So we must 824 * call nd6_rt_flush explicitly. 825 */ 826 nd6_rt_flush(&ip6->ip6_src, ln->lle_tbl->llt_ifp); 827 } 828 ND6_UNLOCK(); 829 } 830 ln->ln_router = is_router; 831 } 832 /* 833 * XXX: does this matter? 834 * rt->rt_flags &= ~RTF_REJECT; 835 */ 836 ln->ln_asked = 0; 837 nd6_llinfo_release_pkts(ln, ifp); 838 /* FIXME */ 839 #if 0 840 if (rt_announce) /* tell user process about any new lladdr */ 841 rt_newmsg(RTM_CHANGE, rt); 842 #endif 843 844 freeit: 845 if (ln != NULL) 846 LLE_WUNLOCK(ln); 847 848 if (checklink) { 849 ND6_WLOCK(); 850 nd6_pfxlist_onlink_check(); 851 ND6_UNLOCK(); 852 } 853 854 m_put_rcvif_psref(ifp, &psref); 855 m_freem(m); 856 return; 857 858 bad: 859 if (ln != NULL) 860 LLE_WUNLOCK(ln); 861 862 ICMP6_STATINC(ICMP6_STAT_BADNA); 863 m_put_rcvif_psref(ifp, &psref); 864 m_freem(m); 865 } 866 867 /* 868 * Neighbor advertisement output handling. 869 * 870 * Based on RFC 2461 871 * 872 * the following items are not implemented yet: 873 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 874 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 875 */ 876 void 877 nd6_na_output( 878 struct ifnet *ifp, 879 const struct in6_addr *daddr6_0, 880 const struct in6_addr *taddr6, 881 u_long flags, 882 int tlladdr, /* 1 if include target link-layer address */ 883 const struct sockaddr *sdl0) /* sockaddr_dl (= proxy NA) or NULL */ 884 { 885 struct mbuf *m; 886 struct ip6_hdr *ip6; 887 struct nd_neighbor_advert *nd_na; 888 struct ip6_moptions im6o; 889 struct sockaddr *dst; 890 union { 891 struct sockaddr dst; 892 struct sockaddr_in6 dst6; 893 } u; 894 struct in6_addr daddr6; 895 int icmp6len, maxlen, error; 896 const void *mac; 897 struct route ro; 898 899 mac = NULL; 900 memset(&ro, 0, sizeof(ro)); 901 902 daddr6 = *daddr6_0; /* make a local copy for modification */ 903 904 /* estimate the size of message */ 905 maxlen = sizeof(*ip6) + sizeof(*nd_na); 906 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 907 KASSERTMSG(max_linkhdr + maxlen < MCLBYTES, 908 "max_linkhdr + maxlen >= MCLBYTES (%d + %d >= %d)", 909 max_linkhdr, maxlen, MCLBYTES); 910 911 MGETHDR(m, M_DONTWAIT, MT_DATA); 912 if (m && max_linkhdr + maxlen >= MHLEN) { 913 MCLGET(m, M_DONTWAIT); 914 if ((m->m_flags & M_EXT) == 0) { 915 m_free(m); 916 m = NULL; 917 } 918 } 919 if (m == NULL) 920 return; 921 m_reset_rcvif(m); 922 923 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 924 m->m_flags |= M_MCAST; 925 im6o.im6o_multicast_if_index = if_get_index(ifp); 926 im6o.im6o_multicast_hlim = 255; 927 im6o.im6o_multicast_loop = 0; 928 } 929 930 icmp6len = sizeof(*nd_na); 931 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 932 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 933 934 /* fill neighbor advertisement packet */ 935 ip6 = mtod(m, struct ip6_hdr *); 936 ip6->ip6_flow = 0; 937 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 938 ip6->ip6_vfc |= IPV6_VERSION; 939 ip6->ip6_nxt = IPPROTO_ICMPV6; 940 ip6->ip6_hlim = 255; 941 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 942 /* reply to DAD */ 943 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 944 daddr6.s6_addr16[1] = 0; 945 daddr6.s6_addr32[1] = 0; 946 daddr6.s6_addr32[2] = 0; 947 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 948 if (in6_setscope(&daddr6, ifp, NULL)) 949 goto bad; 950 951 flags &= ~ND_NA_FLAG_SOLICITED; 952 } 953 ip6->ip6_dst = daddr6; 954 sockaddr_in6_init(&u.dst6, &daddr6, 0, 0, 0); 955 dst = &u.dst; 956 if (rtcache_setdst(&ro, dst) != 0) 957 goto bad; 958 959 /* 960 * Select a source whose scope is the same as that of the dest. 961 */ 962 error = in6_selectsrc(satosin6(dst), NULL, NULL, &ro, NULL, NULL, NULL, 963 &ip6->ip6_src); 964 if (error != 0) { 965 char ip6buf[INET6_ADDRSTRLEN]; 966 nd6log(LOG_DEBUG, "source can't be " 967 "determined: dst=%s, error=%d\n", 968 IN6_PRINT(ip6buf, &satocsin6(dst)->sin6_addr), error); 969 goto bad; 970 } 971 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 972 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 973 nd_na->nd_na_code = 0; 974 nd_na->nd_na_target = *taddr6; 975 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 976 977 /* 978 * "tlladdr" indicates NS's condition for adding tlladdr or not. 979 * see nd6_ns_input() for details. 980 * Basically, if NS packet is sent to unicast/anycast addr, 981 * target lladdr option SHOULD NOT be included. 982 */ 983 if (tlladdr) { 984 /* 985 * sdl0 != NULL indicates proxy NA. If we do proxy, use 986 * lladdr in sdl0. If we are not proxying (sending NA for 987 * my address) use lladdr configured for the interface. 988 */ 989 if (sdl0 == NULL) 990 mac = nd6_ifptomac(ifp); 991 else if (sdl0->sa_family == AF_LINK) { 992 const struct sockaddr_dl *sdl; 993 sdl = satocsdl(sdl0); 994 if (sdl->sdl_alen == ifp->if_addrlen) 995 mac = CLLADDR(sdl); 996 } 997 } 998 if (tlladdr && mac) { 999 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1000 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1001 1002 /* roundup to 8 bytes alignment! */ 1003 optlen = (optlen + 7) & ~7; 1004 1005 m->m_pkthdr.len += optlen; 1006 m->m_len += optlen; 1007 icmp6len += optlen; 1008 memset((void *)nd_opt, 0, optlen); 1009 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1010 nd_opt->nd_opt_len = optlen >> 3; 1011 memcpy((void *)(nd_opt + 1), mac, ifp->if_addrlen); 1012 } else 1013 flags &= ~ND_NA_FLAG_OVERRIDE; 1014 1015 ip6->ip6_plen = htons((u_int16_t)icmp6len); 1016 nd_na->nd_na_flags_reserved = flags; 1017 nd_na->nd_na_cksum = 0; 1018 nd_na->nd_na_cksum = 1019 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1020 1021 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1022 1023 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1024 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1025 ICMP6_STATINC(ICMP6_STAT_OUTHIST + ND_NEIGHBOR_ADVERT); 1026 1027 rtcache_free(&ro); 1028 return; 1029 1030 bad: 1031 rtcache_free(&ro); 1032 m_freem(m); 1033 return; 1034 } 1035 1036 const void * 1037 nd6_ifptomac(const struct ifnet *ifp) 1038 { 1039 switch (ifp->if_type) { 1040 case IFT_ARCNET: 1041 case IFT_ETHER: 1042 case IFT_FDDI: 1043 case IFT_IEEE1394: 1044 case IFT_PROPVIRTUAL: 1045 case IFT_CARP: 1046 case IFT_L2VLAN: 1047 case IFT_IEEE80211: 1048 return CLLADDR(ifp->if_sadl); 1049 default: 1050 return NULL; 1051 } 1052 } 1053 1054 TAILQ_HEAD(dadq_head, dadq); 1055 struct dadq { 1056 TAILQ_ENTRY(dadq) dad_list; 1057 struct ifaddr *dad_ifa; 1058 int dad_count; /* max NS to send */ 1059 int dad_ns_tcount; /* # of trials to send NS */ 1060 int dad_ns_ocount; /* NS sent so far */ 1061 int dad_ns_icount; 1062 int dad_na_icount; 1063 struct callout dad_timer_ch; 1064 }; 1065 1066 static struct dadq_head dadq; 1067 static int dad_init = 0; 1068 static kmutex_t nd6_dad_lock; 1069 1070 static struct dadq * 1071 nd6_dad_find(struct ifaddr *ifa) 1072 { 1073 struct dadq *dp; 1074 1075 KASSERT(mutex_owned(&nd6_dad_lock)); 1076 1077 TAILQ_FOREACH(dp, &dadq, dad_list) { 1078 if (dp->dad_ifa == ifa) 1079 return dp; 1080 } 1081 return NULL; 1082 } 1083 1084 static void 1085 nd6_dad_starttimer(struct dadq *dp, int ticks) 1086 { 1087 1088 callout_reset(&dp->dad_timer_ch, ticks, 1089 (void (*)(void *))nd6_dad_timer, dp); 1090 } 1091 1092 static void 1093 nd6_dad_destroytimer(struct dadq *dp) 1094 { 1095 1096 TAILQ_REMOVE(&dadq, dp, dad_list); 1097 /* Request the timer to destroy dp. */ 1098 dp->dad_ifa = NULL; 1099 callout_reset(&dp->dad_timer_ch, 0, 1100 (void (*)(void *))nd6_dad_timer, dp); 1101 } 1102 1103 /* 1104 * Start Duplicate Address Detection (DAD) for specified interface address. 1105 * 1106 * Note that callout is used when xtick > 0 and not when xtick == 0. 1107 * 1108 * xtick: minimum delay ticks for IFF_UP event 1109 */ 1110 void 1111 nd6_dad_start(struct ifaddr *ifa, int xtick) 1112 { 1113 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1114 struct dadq *dp; 1115 char ip6buf[INET6_ADDRSTRLEN]; 1116 1117 if (!dad_init) { 1118 TAILQ_INIT(&dadq); 1119 mutex_init(&nd6_dad_lock, MUTEX_DEFAULT, IPL_NONE); 1120 dad_init++; 1121 } 1122 1123 /* 1124 * If we don't need DAD, don't do it. 1125 * There are several cases: 1126 * - DAD is disabled (ip6_dad_count == 0) 1127 * - the interface address is anycast 1128 */ 1129 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1130 log(LOG_DEBUG, 1131 "nd6_dad_start: called with non-tentative address " 1132 "%s(%s)\n", 1133 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1134 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1135 return; 1136 } 1137 if (ia->ia6_flags & IN6_IFF_ANYCAST || !ip6_dad_count) { 1138 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1139 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1140 return; 1141 } 1142 KASSERT(ifa->ifa_ifp != NULL); 1143 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1144 return; 1145 1146 dp = kmem_intr_alloc(sizeof(*dp), KM_NOSLEEP); 1147 1148 mutex_enter(&nd6_dad_lock); 1149 if (nd6_dad_find(ifa) != NULL) { 1150 mutex_exit(&nd6_dad_lock); 1151 /* DAD already in progress */ 1152 if (dp != NULL) 1153 kmem_intr_free(dp, sizeof(*dp)); 1154 return; 1155 } 1156 1157 if (dp == NULL) { 1158 mutex_exit(&nd6_dad_lock); 1159 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1160 "%s(%s)\n", 1161 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1162 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1163 return; 1164 } 1165 1166 /* 1167 * Send NS packet for DAD, ip6_dad_count times. 1168 * Note that we must delay the first transmission, if this is the 1169 * first packet to be sent from the interface after interface 1170 * (re)initialization. 1171 */ 1172 callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE); 1173 dp->dad_ifa = ifa; 1174 ifaref(ifa); /* just for safety */ 1175 dp->dad_count = ip6_dad_count; 1176 dp->dad_ns_icount = dp->dad_na_icount = 0; 1177 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1178 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); 1179 1180 nd6log(LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1181 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr)); 1182 1183 if (xtick == 0) { 1184 nd6_dad_ns_output(dp, ifa); 1185 nd6_dad_starttimer(dp, 1186 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1187 } else 1188 nd6_dad_starttimer(dp, xtick); 1189 mutex_exit(&nd6_dad_lock); 1190 } 1191 1192 /* 1193 * terminate DAD unconditionally. used for address removals. 1194 */ 1195 void 1196 nd6_dad_stop(struct ifaddr *ifa) 1197 { 1198 struct dadq *dp; 1199 1200 if (!dad_init) 1201 return; 1202 1203 mutex_enter(&nd6_dad_lock); 1204 dp = nd6_dad_find(ifa); 1205 if (dp == NULL) { 1206 mutex_exit(&nd6_dad_lock); 1207 /* DAD wasn't started yet */ 1208 return; 1209 } 1210 1211 /* Prevent the timer from running anymore. */ 1212 nd6_dad_destroytimer(dp); 1213 1214 mutex_exit(&nd6_dad_lock); 1215 1216 ifafree(ifa); 1217 } 1218 1219 static void 1220 nd6_dad_timer(struct dadq *dp) 1221 { 1222 struct ifaddr *ifa; 1223 struct in6_ifaddr *ia; 1224 int duplicate = 0; 1225 char ip6buf[INET6_ADDRSTRLEN]; 1226 bool need_free = false; 1227 1228 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE(); 1229 mutex_enter(&nd6_dad_lock); 1230 1231 ifa = dp->dad_ifa; 1232 if (ifa == NULL) { 1233 /* ifa is being deleted. DAD should be freed too. */ 1234 if (callout_pending(&dp->dad_timer_ch)) { 1235 /* 1236 * The callout is scheduled again, so we cannot destroy 1237 * dp in this run. 1238 */ 1239 goto done; 1240 } 1241 need_free = true; 1242 goto done; 1243 } 1244 1245 ia = (struct in6_ifaddr *)ifa; 1246 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1247 log(LOG_ERR, "nd6_dad_timer: called with duplicate address " 1248 "%s(%s)\n", 1249 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1250 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1251 goto done; 1252 } 1253 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1254 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1255 "%s(%s)\n", 1256 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1257 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1258 goto done; 1259 } 1260 1261 /* timeouted with IFF_{RUNNING,UP} check */ 1262 if (dp->dad_ns_tcount > dad_maxtry) { 1263 nd6log(LOG_INFO, "%s: could not run DAD, driver problem?\n", 1264 if_name(ifa->ifa_ifp)); 1265 1266 TAILQ_REMOVE(&dadq, dp, dad_list); 1267 need_free = true; 1268 goto done; 1269 } 1270 1271 /* Need more checks? */ 1272 if (dp->dad_ns_ocount < dp->dad_count) { 1273 /* 1274 * We have more NS to go. Send NS packet for DAD. 1275 */ 1276 nd6_dad_ns_output(dp, ifa); 1277 nd6_dad_starttimer(dp, 1278 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1279 } else { 1280 /* 1281 * We have transmitted sufficient number of DAD packets. 1282 * See what we've got. 1283 */ 1284 if (dp->dad_na_icount) { 1285 /* 1286 * the check is in nd6_dad_na_input(), 1287 * but just in case 1288 */ 1289 duplicate++; 1290 } 1291 1292 if (dp->dad_ns_icount) { 1293 /* We've seen NS, means DAD has failed. */ 1294 duplicate++; 1295 } 1296 1297 if (duplicate) { 1298 /* (*dp) will be freed in nd6_dad_duplicated() */ 1299 dp = NULL; 1300 } else { 1301 /* 1302 * We are done with DAD. No NA came, no NS came. 1303 * No duplicate address found. 1304 */ 1305 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1306 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1307 1308 nd6log(LOG_DEBUG, 1309 "%s: DAD complete for %s - no duplicates found\n", 1310 if_name(ifa->ifa_ifp), 1311 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr)); 1312 1313 TAILQ_REMOVE(&dadq, dp, dad_list); 1314 need_free = true; 1315 } 1316 } 1317 done: 1318 mutex_exit(&nd6_dad_lock); 1319 1320 if (need_free) { 1321 callout_destroy(&dp->dad_timer_ch); 1322 kmem_intr_free(dp, sizeof(*dp)); 1323 if (ifa != NULL) 1324 ifafree(ifa); 1325 } 1326 1327 if (duplicate) 1328 nd6_dad_duplicated(ifa); 1329 1330 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 1331 } 1332 1333 static void 1334 nd6_dad_duplicated(struct ifaddr *ifa) 1335 { 1336 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1337 struct ifnet *ifp; 1338 struct dadq *dp; 1339 char ip6buf[INET6_ADDRSTRLEN]; 1340 1341 mutex_enter(&nd6_dad_lock); 1342 dp = nd6_dad_find(ifa); 1343 if (dp == NULL) { 1344 mutex_exit(&nd6_dad_lock); 1345 /* DAD seems to be stopping, so do nothing. */ 1346 return; 1347 } 1348 1349 ifp = ifa->ifa_ifp; 1350 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1351 "NS in/out=%d/%d, NA in=%d\n", 1352 if_name(ifp), IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1353 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount); 1354 1355 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1356 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1357 1358 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1359 if_name(ifp), IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr)); 1360 log(LOG_ERR, "%s: manual intervention required\n", 1361 if_name(ifp)); 1362 1363 /* Inform the routing socket that DAD has completed */ 1364 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1365 1366 /* 1367 * If the address is a link-local address formed from an interface 1368 * identifier based on the hardware address which is supposed to be 1369 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1370 * operation on the interface SHOULD be disabled. 1371 * [rfc2462bis-03 Section 5.4.5] 1372 */ 1373 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1374 struct in6_addr in6; 1375 1376 /* 1377 * To avoid over-reaction, we only apply this logic when we are 1378 * very sure that hardware addresses are supposed to be unique. 1379 */ 1380 switch (ifp->if_type) { 1381 case IFT_ETHER: 1382 case IFT_FDDI: 1383 case IFT_ATM: 1384 case IFT_IEEE1394: 1385 #ifdef IFT_IEEE80211 1386 case IFT_IEEE80211: 1387 #endif 1388 in6 = ia->ia_addr.sin6_addr; 1389 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1390 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1391 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1392 log(LOG_ERR, "%s: possible hardware address " 1393 "duplication detected, disable IPv6\n", 1394 if_name(ifp)); 1395 } 1396 break; 1397 } 1398 } 1399 1400 /* We are done with DAD, with duplicated address found. (failure) */ 1401 nd6_dad_destroytimer(dp); 1402 1403 mutex_exit(&nd6_dad_lock); 1404 1405 ifafree(ifa); 1406 } 1407 1408 static void 1409 nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa) 1410 { 1411 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1412 struct ifnet *ifp = ifa->ifa_ifp; 1413 1414 dp->dad_ns_tcount++; 1415 if ((ifp->if_flags & IFF_UP) == 0) { 1416 #if 0 1417 printf("%s: interface down?\n", if_name(ifp)); 1418 #endif 1419 return; 1420 } 1421 if ((ifp->if_flags & IFF_RUNNING) == 0) { 1422 #if 0 1423 printf("%s: interface not running?\n", if_name(ifp)); 1424 #endif 1425 return; 1426 } 1427 1428 dp->dad_ns_tcount = 0; 1429 dp->dad_ns_ocount++; 1430 nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1); 1431 } 1432 1433 static void 1434 nd6_dad_ns_input(struct ifaddr *ifa) 1435 { 1436 struct in6_ifaddr *ia; 1437 const struct in6_addr *taddr6; 1438 struct dadq *dp; 1439 int duplicate; 1440 1441 if (ifa == NULL) 1442 panic("ifa == NULL in nd6_dad_ns_input"); 1443 1444 ia = (struct in6_ifaddr *)ifa; 1445 taddr6 = &ia->ia_addr.sin6_addr; 1446 duplicate = 0; 1447 1448 mutex_enter(&nd6_dad_lock); 1449 dp = nd6_dad_find(ifa); 1450 1451 /* Quickhack - completely ignore DAD NS packets */ 1452 if (dad_ignore_ns) { 1453 char ip6buf[INET6_ADDRSTRLEN]; 1454 nd6log(LOG_INFO, "ignoring DAD NS packet for " 1455 "address %s(%s)\n", IN6_PRINT(ip6buf, taddr6), 1456 if_name(ifa->ifa_ifp)); 1457 return; 1458 } 1459 1460 /* 1461 * if I'm yet to start DAD, someone else started using this address 1462 * first. I have a duplicate and you win. 1463 */ 1464 if (dp == NULL || dp->dad_ns_ocount == 0) 1465 duplicate++; 1466 1467 /* XXX more checks for loopback situation - see nd6_dad_timer too */ 1468 1469 if (duplicate) { 1470 dp = NULL; /* will be freed in nd6_dad_duplicated() */ 1471 mutex_exit(&nd6_dad_lock); 1472 nd6_dad_duplicated(ifa); 1473 } else { 1474 /* 1475 * not sure if I got a duplicate. 1476 * increment ns count and see what happens. 1477 */ 1478 if (dp) 1479 dp->dad_ns_icount++; 1480 mutex_exit(&nd6_dad_lock); 1481 } 1482 } 1483 1484 static void 1485 nd6_dad_na_input(struct ifaddr *ifa) 1486 { 1487 struct dadq *dp; 1488 1489 if (ifa == NULL) 1490 panic("ifa == NULL in nd6_dad_na_input"); 1491 1492 mutex_enter(&nd6_dad_lock); 1493 dp = nd6_dad_find(ifa); 1494 if (dp) 1495 dp->dad_na_icount++; 1496 mutex_exit(&nd6_dad_lock); 1497 1498 /* remove the address. */ 1499 nd6_dad_duplicated(ifa); 1500 } 1501
Indexes created Thu Oct 23 22:10:10 GMT 2025