nd6_nbr.c revision 1.144
1 /* $NetBSD: nd6_nbr.c,v 1.144 2018/01/16 08:13:47 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 1.144 2018/01/16 08:13:47 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_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 m_put_rcvif_psref(ifp, &psref); 611 return; /* XXX: impossible */ 612 } 613 614 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 615 nd6log(LOG_ERR, "invalid target address %s\n", 616 IN6_PRINT(ip6buf, &taddr6)); 617 goto bad; 618 } 619 if (is_solicited && IN6_IS_ADDR_MULTICAST(&daddr6)) { 620 nd6log(LOG_ERR, "a solicited adv is multicasted\n"); 621 goto bad; 622 } 623 624 icmp6len -= sizeof(*nd_na); 625 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 626 if (nd6_options(&ndopts) < 0) { 627 nd6log(LOG_INFO, "invalid ND option, ignored\n"); 628 /* nd6_options have incremented stats */ 629 goto freeit; 630 } 631 632 if (ndopts.nd_opts_tgt_lladdr) { 633 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 634 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 635 } 636 637 ifa = (struct ifaddr *)in6ifa_ifpwithaddr_psref(ifp, &taddr6, &psref_ia); 638 639 /* 640 * Target address matches one of my interface address. 641 * 642 * If my address is tentative, this means that there's somebody 643 * already using the same address as mine. This indicates DAD failure. 644 * This is defined in RFC 2462. 645 * 646 * Otherwise, process as defined in RFC 2461. 647 */ 648 if (ifa 649 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 650 nd6_dad_na_input(ifa); 651 ifa_release(ifa, &psref_ia); 652 ifa = NULL; 653 goto freeit; 654 } 655 656 /* Just for safety, maybe unnecessary. */ 657 if (ifa) { 658 log(LOG_ERR, 659 "nd6_na_input: duplicate IP6 address %s\n", 660 IN6_PRINT(ip6buf, &taddr6)); 661 ifa_release(ifa, &psref_ia); 662 ifa = NULL; 663 goto freeit; 664 } 665 666 /* 667 * Make sure the source address is from a neighbor's address. 668 */ 669 sockaddr_in6_init(&ssin6, &saddr6, 0, 0, 0); 670 if (nd6_is_addr_neighbor(&ssin6, ifp) == 0) { 671 nd6log(LOG_INFO, "ND packet from non-neighbor %s on %s\n", 672 IN6_PRINT(ip6buf, &saddr6), if_name(ifp)); 673 goto bad; 674 } 675 676 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 677 nd6log(LOG_INFO, "lladdrlen mismatch for %s " 678 "(if %d, NA packet %d)\n", IN6_PRINT(ip6buf, &taddr6), 679 ifp->if_addrlen, lladdrlen - 2); 680 goto bad; 681 } 682 683 /* 684 * If no neighbor cache entry is found, NA SHOULD silently be 685 * discarded. 686 */ 687 ln = nd6_lookup(&taddr6, ifp, true); 688 if (ln == NULL) 689 goto freeit; 690 691 rt_announce = 0; 692 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 693 /* 694 * If the link-layer has address, and no lladdr option came, 695 * discard the packet. 696 */ 697 if (ifp->if_addrlen && !lladdr) 698 goto freeit; 699 700 /* 701 * Record link-layer address, and update the state. 702 */ 703 memcpy(&ln->ll_addr, lladdr, ifp->if_addrlen); 704 ln->la_flags |= LLE_VALID; 705 rt_announce = 1; 706 if (is_solicited) { 707 ln->ln_state = ND6_LLINFO_REACHABLE; 708 ln->ln_byhint = 0; 709 if (!ND6_LLINFO_PERMANENT(ln)) { 710 nd6_llinfo_settimer(ln, 711 ND_IFINFO(ln->lle_tbl->llt_ifp)->reachable * hz); 712 } 713 } else { 714 ln->ln_state = ND6_LLINFO_STALE; 715 nd6_llinfo_settimer(ln, nd6_gctimer * hz); 716 } 717 if ((ln->ln_router = is_router) != 0) { 718 /* 719 * This means a router's state has changed from 720 * non-reachable to probably reachable, and might 721 * affect the status of associated prefixes.. 722 */ 723 checklink = true; 724 } 725 } else { 726 int llchange; 727 728 /* 729 * Check if the link-layer address has changed or not. 730 */ 731 if (lladdr == NULL) 732 llchange = 0; 733 else { 734 if (ln->la_flags & LLE_VALID) { 735 if (memcmp(lladdr, &ln->ll_addr, ifp->if_addrlen)) 736 llchange = rt_announce = 1; 737 else 738 llchange = 0; 739 } else 740 llchange = rt_announce = 1; 741 } 742 743 /* 744 * This is VERY complex. Look at it with care. 745 * 746 * override solicit lladdr llchange action 747 * (L: record lladdr) 748 * 749 * 0 0 n -- (2c) 750 * 0 0 y n (2b) L 751 * 0 0 y y (1) REACHABLE->STALE 752 * 0 1 n -- (2c) *->REACHABLE 753 * 0 1 y n (2b) L *->REACHABLE 754 * 0 1 y y (1) REACHABLE->STALE 755 * 1 0 n -- (2a) 756 * 1 0 y n (2a) L 757 * 1 0 y y (2a) L *->STALE 758 * 1 1 n -- (2a) *->REACHABLE 759 * 1 1 y n (2a) L *->REACHABLE 760 * 1 1 y y (2a) L *->REACHABLE 761 */ 762 if (!is_override && lladdr != NULL && llchange) { /* (1) */ 763 /* 764 * If state is REACHABLE, make it STALE. 765 * no other updates should be done. 766 */ 767 if (ln->ln_state == ND6_LLINFO_REACHABLE) { 768 ln->ln_state = ND6_LLINFO_STALE; 769 nd6_llinfo_settimer(ln, nd6_gctimer * hz); 770 } 771 goto freeit; 772 } else if (is_override /* (2a) */ 773 || (!is_override && lladdr != NULL && !llchange) /* (2b) */ 774 || lladdr == NULL) { /* (2c) */ 775 /* 776 * Update link-local address, if any. 777 */ 778 if (lladdr != NULL) { 779 memcpy(&ln->ll_addr, lladdr, ifp->if_addrlen); 780 ln->la_flags |= LLE_VALID; 781 } 782 783 /* 784 * If solicited, make the state REACHABLE. 785 * If not solicited and the link-layer address was 786 * changed, make it STALE. 787 */ 788 if (is_solicited) { 789 ln->ln_state = ND6_LLINFO_REACHABLE; 790 ln->ln_byhint = 0; 791 if (!ND6_LLINFO_PERMANENT(ln)) { 792 nd6_llinfo_settimer(ln, 793 ND_IFINFO(ifp)->reachable * hz); 794 } 795 } else { 796 if (lladdr && llchange) { 797 ln->ln_state = ND6_LLINFO_STALE; 798 nd6_llinfo_settimer(ln, 799 nd6_gctimer * hz); 800 } 801 } 802 } 803 804 if (ln->ln_router && !is_router) { 805 /* 806 * The peer dropped the router flag. 807 * Remove the sender from the Default Router List and 808 * update the Destination Cache entries. 809 */ 810 struct nd_defrouter *dr; 811 const struct in6_addr *in6; 812 813 in6 = &ln->r_l3addr.addr6; 814 815 ND6_WLOCK(); 816 dr = nd6_defrouter_lookup(in6, ln->lle_tbl->llt_ifp); 817 if (dr) 818 nd6_defrtrlist_del(dr, NULL); 819 else if (!ip6_forwarding) { 820 /* 821 * Even if the neighbor is not in the default 822 * router list, the neighbor may be used 823 * as a next hop for some destinations 824 * (e.g. redirect case). So we must 825 * call nd6_rt_flush explicitly. 826 */ 827 nd6_rt_flush(&ip6->ip6_src, ln->lle_tbl->llt_ifp); 828 } 829 ND6_UNLOCK(); 830 } 831 ln->ln_router = is_router; 832 } 833 /* 834 * XXX: does this matter? 835 * rt->rt_flags &= ~RTF_REJECT; 836 */ 837 ln->ln_asked = 0; 838 nd6_llinfo_release_pkts(ln, ifp); 839 /* FIXME */ 840 #if 0 841 if (rt_announce) /* tell user process about any new lladdr */ 842 rt_newmsg(RTM_CHANGE, rt); 843 #endif 844 845 freeit: 846 if (ln != NULL) 847 LLE_WUNLOCK(ln); 848 849 if (checklink) { 850 ND6_WLOCK(); 851 nd6_pfxlist_onlink_check(); 852 ND6_UNLOCK(); 853 } 854 855 m_put_rcvif_psref(ifp, &psref); 856 m_freem(m); 857 return; 858 859 bad: 860 if (ln != NULL) 861 LLE_WUNLOCK(ln); 862 863 ICMP6_STATINC(ICMP6_STAT_BADNA); 864 m_put_rcvif_psref(ifp, &psref); 865 m_freem(m); 866 } 867 868 /* 869 * Neighbor advertisement output handling. 870 * 871 * Based on RFC 2461 872 * 873 * the following items are not implemented yet: 874 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 875 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 876 */ 877 void 878 nd6_na_output( 879 struct ifnet *ifp, 880 const struct in6_addr *daddr6_0, 881 const struct in6_addr *taddr6, 882 u_long flags, 883 int tlladdr, /* 1 if include target link-layer address */ 884 const struct sockaddr *sdl0) /* sockaddr_dl (= proxy NA) or NULL */ 885 { 886 struct mbuf *m; 887 struct ip6_hdr *ip6; 888 struct nd_neighbor_advert *nd_na; 889 struct ip6_moptions im6o; 890 struct sockaddr *dst; 891 union { 892 struct sockaddr dst; 893 struct sockaddr_in6 dst6; 894 } u; 895 struct in6_addr daddr6; 896 int icmp6len, maxlen, error; 897 const void *mac; 898 struct route ro; 899 900 mac = NULL; 901 memset(&ro, 0, sizeof(ro)); 902 903 daddr6 = *daddr6_0; /* make a local copy for modification */ 904 905 /* estimate the size of message */ 906 maxlen = sizeof(*ip6) + sizeof(*nd_na); 907 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 908 KASSERTMSG(max_linkhdr + maxlen < MCLBYTES, 909 "max_linkhdr + maxlen >= MCLBYTES (%d + %d >= %d)", 910 max_linkhdr, maxlen, MCLBYTES); 911 912 MGETHDR(m, M_DONTWAIT, MT_DATA); 913 if (m && max_linkhdr + maxlen >= MHLEN) { 914 MCLGET(m, M_DONTWAIT); 915 if ((m->m_flags & M_EXT) == 0) { 916 m_free(m); 917 m = NULL; 918 } 919 } 920 if (m == NULL) 921 return; 922 m_reset_rcvif(m); 923 924 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 925 m->m_flags |= M_MCAST; 926 im6o.im6o_multicast_if_index = if_get_index(ifp); 927 im6o.im6o_multicast_hlim = 255; 928 im6o.im6o_multicast_loop = 0; 929 } 930 931 icmp6len = sizeof(*nd_na); 932 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 933 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 934 935 /* fill neighbor advertisement packet */ 936 ip6 = mtod(m, struct ip6_hdr *); 937 ip6->ip6_flow = 0; 938 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 939 ip6->ip6_vfc |= IPV6_VERSION; 940 ip6->ip6_nxt = IPPROTO_ICMPV6; 941 ip6->ip6_hlim = 255; 942 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 943 /* reply to DAD */ 944 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 945 daddr6.s6_addr16[1] = 0; 946 daddr6.s6_addr32[1] = 0; 947 daddr6.s6_addr32[2] = 0; 948 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 949 if (in6_setscope(&daddr6, ifp, NULL)) 950 goto bad; 951 952 flags &= ~ND_NA_FLAG_SOLICITED; 953 } 954 ip6->ip6_dst = daddr6; 955 sockaddr_in6_init(&u.dst6, &daddr6, 0, 0, 0); 956 dst = &u.dst; 957 if (rtcache_setdst(&ro, dst) != 0) 958 goto bad; 959 960 /* 961 * Select a source whose scope is the same as that of the dest. 962 */ 963 error = in6_selectsrc(satosin6(dst), NULL, NULL, &ro, NULL, NULL, NULL, 964 &ip6->ip6_src); 965 if (error != 0) { 966 char ip6buf[INET6_ADDRSTRLEN]; 967 nd6log(LOG_DEBUG, "source can't be " 968 "determined: dst=%s, error=%d\n", 969 IN6_PRINT(ip6buf, &satocsin6(dst)->sin6_addr), error); 970 goto bad; 971 } 972 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 973 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 974 nd_na->nd_na_code = 0; 975 nd_na->nd_na_target = *taddr6; 976 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 977 978 /* 979 * "tlladdr" indicates NS's condition for adding tlladdr or not. 980 * see nd6_ns_input() for details. 981 * Basically, if NS packet is sent to unicast/anycast addr, 982 * target lladdr option SHOULD NOT be included. 983 */ 984 if (tlladdr) { 985 /* 986 * sdl0 != NULL indicates proxy NA. If we do proxy, use 987 * lladdr in sdl0. If we are not proxying (sending NA for 988 * my address) use lladdr configured for the interface. 989 */ 990 if (sdl0 == NULL) 991 mac = nd6_ifptomac(ifp); 992 else if (sdl0->sa_family == AF_LINK) { 993 const struct sockaddr_dl *sdl; 994 sdl = satocsdl(sdl0); 995 if (sdl->sdl_alen == ifp->if_addrlen) 996 mac = CLLADDR(sdl); 997 } 998 } 999 if (tlladdr && mac) { 1000 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1001 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1002 1003 /* roundup to 8 bytes alignment! */ 1004 optlen = (optlen + 7) & ~7; 1005 1006 m->m_pkthdr.len += optlen; 1007 m->m_len += optlen; 1008 icmp6len += optlen; 1009 memset((void *)nd_opt, 0, optlen); 1010 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1011 nd_opt->nd_opt_len = optlen >> 3; 1012 memcpy((void *)(nd_opt + 1), mac, ifp->if_addrlen); 1013 } else 1014 flags &= ~ND_NA_FLAG_OVERRIDE; 1015 1016 ip6->ip6_plen = htons((u_int16_t)icmp6len); 1017 nd_na->nd_na_flags_reserved = flags; 1018 nd_na->nd_na_cksum = 0; 1019 nd_na->nd_na_cksum = 1020 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1021 1022 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1023 1024 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1025 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1026 ICMP6_STATINC(ICMP6_STAT_OUTHIST + ND_NEIGHBOR_ADVERT); 1027 1028 rtcache_free(&ro); 1029 return; 1030 1031 bad: 1032 rtcache_free(&ro); 1033 m_freem(m); 1034 return; 1035 } 1036 1037 const void * 1038 nd6_ifptomac(const struct ifnet *ifp) 1039 { 1040 switch (ifp->if_type) { 1041 case IFT_ARCNET: 1042 case IFT_ETHER: 1043 case IFT_FDDI: 1044 case IFT_IEEE1394: 1045 case IFT_PROPVIRTUAL: 1046 case IFT_CARP: 1047 case IFT_L2VLAN: 1048 case IFT_IEEE80211: 1049 return CLLADDR(ifp->if_sadl); 1050 default: 1051 return NULL; 1052 } 1053 } 1054 1055 TAILQ_HEAD(dadq_head, dadq); 1056 struct dadq { 1057 TAILQ_ENTRY(dadq) dad_list; 1058 struct ifaddr *dad_ifa; 1059 int dad_count; /* max NS to send */ 1060 int dad_ns_tcount; /* # of trials to send NS */ 1061 int dad_ns_ocount; /* NS sent so far */ 1062 int dad_ns_icount; 1063 int dad_na_icount; 1064 struct callout dad_timer_ch; 1065 }; 1066 1067 static struct dadq_head dadq; 1068 static int dad_init = 0; 1069 static kmutex_t nd6_dad_lock; 1070 1071 static struct dadq * 1072 nd6_dad_find(struct ifaddr *ifa) 1073 { 1074 struct dadq *dp; 1075 1076 KASSERT(mutex_owned(&nd6_dad_lock)); 1077 1078 TAILQ_FOREACH(dp, &dadq, dad_list) { 1079 if (dp->dad_ifa == ifa) 1080 return dp; 1081 } 1082 return NULL; 1083 } 1084 1085 static void 1086 nd6_dad_starttimer(struct dadq *dp, int ticks) 1087 { 1088 1089 callout_reset(&dp->dad_timer_ch, ticks, 1090 (void (*)(void *))nd6_dad_timer, dp); 1091 } 1092 1093 static void 1094 nd6_dad_destroytimer(struct dadq *dp) 1095 { 1096 1097 TAILQ_REMOVE(&dadq, dp, dad_list); 1098 /* Request the timer to destroy dp. */ 1099 dp->dad_ifa = NULL; 1100 callout_reset(&dp->dad_timer_ch, 0, 1101 (void (*)(void *))nd6_dad_timer, dp); 1102 } 1103 1104 /* 1105 * Start Duplicate Address Detection (DAD) for specified interface address. 1106 * 1107 * Note that callout is used when xtick > 0 and not when xtick == 0. 1108 * 1109 * xtick: minimum delay ticks for IFF_UP event 1110 */ 1111 void 1112 nd6_dad_start(struct ifaddr *ifa, int xtick) 1113 { 1114 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1115 struct dadq *dp; 1116 char ip6buf[INET6_ADDRSTRLEN]; 1117 1118 if (!dad_init) { 1119 TAILQ_INIT(&dadq); 1120 mutex_init(&nd6_dad_lock, MUTEX_DEFAULT, IPL_NONE); 1121 dad_init++; 1122 } 1123 1124 /* 1125 * If we don't need DAD, don't do it. 1126 * There are several cases: 1127 * - DAD is disabled (ip6_dad_count == 0) 1128 * - the interface address is anycast 1129 */ 1130 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1131 log(LOG_DEBUG, 1132 "nd6_dad_start: called with non-tentative address " 1133 "%s(%s)\n", 1134 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1135 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1136 return; 1137 } 1138 if (ia->ia6_flags & IN6_IFF_ANYCAST || !ip6_dad_count) { 1139 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1140 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1141 return; 1142 } 1143 KASSERT(ifa->ifa_ifp != NULL); 1144 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1145 return; 1146 1147 dp = kmem_intr_alloc(sizeof(*dp), KM_NOSLEEP); 1148 1149 mutex_enter(&nd6_dad_lock); 1150 if (nd6_dad_find(ifa) != NULL) { 1151 mutex_exit(&nd6_dad_lock); 1152 /* DAD already in progress */ 1153 if (dp != NULL) 1154 kmem_intr_free(dp, sizeof(*dp)); 1155 return; 1156 } 1157 1158 if (dp == NULL) { 1159 mutex_exit(&nd6_dad_lock); 1160 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1161 "%s(%s)\n", 1162 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1163 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1164 return; 1165 } 1166 1167 /* 1168 * Send NS packet for DAD, ip6_dad_count times. 1169 * Note that we must delay the first transmission, if this is the 1170 * first packet to be sent from the interface after interface 1171 * (re)initialization. 1172 */ 1173 callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE); 1174 dp->dad_ifa = ifa; 1175 ifaref(ifa); /* just for safety */ 1176 dp->dad_count = ip6_dad_count; 1177 dp->dad_ns_icount = dp->dad_na_icount = 0; 1178 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1179 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); 1180 1181 nd6log(LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1182 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr)); 1183 1184 if (xtick == 0) { 1185 nd6_dad_ns_output(dp, ifa); 1186 nd6_dad_starttimer(dp, 1187 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1188 } else 1189 nd6_dad_starttimer(dp, xtick); 1190 mutex_exit(&nd6_dad_lock); 1191 } 1192 1193 /* 1194 * terminate DAD unconditionally. used for address removals. 1195 */ 1196 void 1197 nd6_dad_stop(struct ifaddr *ifa) 1198 { 1199 struct dadq *dp; 1200 1201 if (!dad_init) 1202 return; 1203 1204 mutex_enter(&nd6_dad_lock); 1205 dp = nd6_dad_find(ifa); 1206 if (dp == NULL) { 1207 mutex_exit(&nd6_dad_lock); 1208 /* DAD wasn't started yet */ 1209 return; 1210 } 1211 1212 /* Prevent the timer from running anymore. */ 1213 nd6_dad_destroytimer(dp); 1214 1215 mutex_exit(&nd6_dad_lock); 1216 1217 ifafree(ifa); 1218 } 1219 1220 static void 1221 nd6_dad_timer(struct dadq *dp) 1222 { 1223 struct ifaddr *ifa; 1224 struct in6_ifaddr *ia; 1225 int duplicate = 0; 1226 char ip6buf[INET6_ADDRSTRLEN]; 1227 bool need_free = false; 1228 1229 SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE(); 1230 mutex_enter(&nd6_dad_lock); 1231 1232 ifa = dp->dad_ifa; 1233 if (ifa == NULL) { 1234 /* ifa is being deleted. DAD should be freed too. */ 1235 if (callout_pending(&dp->dad_timer_ch)) { 1236 /* 1237 * The callout is scheduled again, so we cannot destroy 1238 * dp in this run. 1239 */ 1240 goto done; 1241 } 1242 need_free = true; 1243 goto done; 1244 } 1245 1246 ia = (struct in6_ifaddr *)ifa; 1247 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1248 log(LOG_ERR, "nd6_dad_timer: called with duplicate address " 1249 "%s(%s)\n", 1250 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1251 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1252 goto done; 1253 } 1254 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1255 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1256 "%s(%s)\n", 1257 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1258 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1259 goto done; 1260 } 1261 1262 /* timeouted with IFF_{RUNNING,UP} check */ 1263 if (dp->dad_ns_tcount > dad_maxtry) { 1264 nd6log(LOG_INFO, "%s: could not run DAD, driver problem?\n", 1265 if_name(ifa->ifa_ifp)); 1266 1267 TAILQ_REMOVE(&dadq, dp, dad_list); 1268 need_free = true; 1269 goto done; 1270 } 1271 1272 /* Need more checks? */ 1273 if (dp->dad_ns_ocount < dp->dad_count) { 1274 /* 1275 * We have more NS to go. Send NS packet for DAD. 1276 */ 1277 nd6_dad_ns_output(dp, ifa); 1278 nd6_dad_starttimer(dp, 1279 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1280 } else { 1281 /* 1282 * We have transmitted sufficient number of DAD packets. 1283 * See what we've got. 1284 */ 1285 if (dp->dad_na_icount) { 1286 /* 1287 * the check is in nd6_dad_na_input(), 1288 * but just in case 1289 */ 1290 duplicate++; 1291 } 1292 1293 if (dp->dad_ns_icount) { 1294 /* We've seen NS, means DAD has failed. */ 1295 duplicate++; 1296 } 1297 1298 if (duplicate) { 1299 /* (*dp) will be freed in nd6_dad_duplicated() */ 1300 dp = NULL; 1301 } else { 1302 /* 1303 * We are done with DAD. No NA came, no NS came. 1304 * No duplicate address found. 1305 */ 1306 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1307 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1308 1309 nd6log(LOG_DEBUG, 1310 "%s: DAD complete for %s - no duplicates found\n", 1311 if_name(ifa->ifa_ifp), 1312 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr)); 1313 1314 TAILQ_REMOVE(&dadq, dp, dad_list); 1315 need_free = true; 1316 } 1317 } 1318 done: 1319 mutex_exit(&nd6_dad_lock); 1320 1321 if (need_free) { 1322 callout_destroy(&dp->dad_timer_ch); 1323 kmem_intr_free(dp, sizeof(*dp)); 1324 if (ifa != NULL) 1325 ifafree(ifa); 1326 } 1327 1328 if (duplicate) 1329 nd6_dad_duplicated(ifa); 1330 1331 SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 1332 } 1333 1334 static void 1335 nd6_dad_duplicated(struct ifaddr *ifa) 1336 { 1337 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1338 struct ifnet *ifp; 1339 struct dadq *dp; 1340 char ip6buf[INET6_ADDRSTRLEN]; 1341 1342 mutex_enter(&nd6_dad_lock); 1343 dp = nd6_dad_find(ifa); 1344 if (dp == NULL) { 1345 mutex_exit(&nd6_dad_lock); 1346 /* DAD seems to be stopping, so do nothing. */ 1347 return; 1348 } 1349 1350 ifp = ifa->ifa_ifp; 1351 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1352 "NS in/out=%d/%d, NA in=%d\n", 1353 if_name(ifp), IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1354 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount); 1355 1356 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1357 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1358 1359 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1360 if_name(ifp), IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr)); 1361 log(LOG_ERR, "%s: manual intervention required\n", 1362 if_name(ifp)); 1363 1364 /* Inform the routing socket that DAD has completed */ 1365 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1366 1367 /* 1368 * If the address is a link-local address formed from an interface 1369 * identifier based on the hardware address which is supposed to be 1370 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1371 * operation on the interface SHOULD be disabled. 1372 * [rfc2462bis-03 Section 5.4.5] 1373 */ 1374 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1375 struct in6_addr in6; 1376 1377 /* 1378 * To avoid over-reaction, we only apply this logic when we are 1379 * very sure that hardware addresses are supposed to be unique. 1380 */ 1381 switch (ifp->if_type) { 1382 case IFT_ETHER: 1383 case IFT_FDDI: 1384 case IFT_ATM: 1385 case IFT_IEEE1394: 1386 case IFT_IEEE80211: 1387 in6 = ia->ia_addr.sin6_addr; 1388 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1389 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1390 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1391 log(LOG_ERR, "%s: possible hardware address " 1392 "duplication detected, disable IPv6\n", 1393 if_name(ifp)); 1394 } 1395 break; 1396 } 1397 } 1398 1399 /* We are done with DAD, with duplicated address found. (failure) */ 1400 nd6_dad_destroytimer(dp); 1401 1402 mutex_exit(&nd6_dad_lock); 1403 1404 ifafree(ifa); 1405 } 1406 1407 static void 1408 nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa) 1409 { 1410 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1411 struct ifnet *ifp = ifa->ifa_ifp; 1412 1413 dp->dad_ns_tcount++; 1414 if ((ifp->if_flags & IFF_UP) == 0) { 1415 #if 0 1416 printf("%s: interface down?\n", if_name(ifp)); 1417 #endif 1418 return; 1419 } 1420 if ((ifp->if_flags & IFF_RUNNING) == 0) { 1421 #if 0 1422 printf("%s: interface not running?\n", if_name(ifp)); 1423 #endif 1424 return; 1425 } 1426 1427 dp->dad_ns_tcount = 0; 1428 dp->dad_ns_ocount++; 1429 nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1); 1430 } 1431 1432 static void 1433 nd6_dad_ns_input(struct ifaddr *ifa) 1434 { 1435 struct in6_ifaddr *ia; 1436 const struct in6_addr *taddr6; 1437 struct dadq *dp; 1438 int duplicate; 1439 1440 if (ifa == NULL) 1441 panic("ifa == NULL in nd6_dad_ns_input"); 1442 1443 ia = (struct in6_ifaddr *)ifa; 1444 taddr6 = &ia->ia_addr.sin6_addr; 1445 duplicate = 0; 1446 1447 mutex_enter(&nd6_dad_lock); 1448 dp = nd6_dad_find(ifa); 1449 1450 /* Quickhack - completely ignore DAD NS packets */ 1451 if (dad_ignore_ns) { 1452 char ip6buf[INET6_ADDRSTRLEN]; 1453 nd6log(LOG_INFO, "ignoring DAD NS packet for " 1454 "address %s(%s)\n", IN6_PRINT(ip6buf, taddr6), 1455 if_name(ifa->ifa_ifp)); 1456 return; 1457 } 1458 1459 /* 1460 * if I'm yet to start DAD, someone else started using this address 1461 * first. I have a duplicate and you win. 1462 */ 1463 if (dp == NULL || dp->dad_ns_ocount == 0) 1464 duplicate++; 1465 1466 /* XXX more checks for loopback situation - see nd6_dad_timer too */ 1467 1468 if (duplicate) { 1469 dp = NULL; /* will be freed in nd6_dad_duplicated() */ 1470 mutex_exit(&nd6_dad_lock); 1471 nd6_dad_duplicated(ifa); 1472 } else { 1473 /* 1474 * not sure if I got a duplicate. 1475 * increment ns count and see what happens. 1476 */ 1477 if (dp) 1478 dp->dad_ns_icount++; 1479 mutex_exit(&nd6_dad_lock); 1480 } 1481 } 1482 1483 static void 1484 nd6_dad_na_input(struct ifaddr *ifa) 1485 { 1486 struct dadq *dp; 1487 1488 if (ifa == NULL) 1489 panic("ifa == NULL in nd6_dad_na_input"); 1490 1491 mutex_enter(&nd6_dad_lock); 1492 dp = nd6_dad_find(ifa); 1493 if (dp) 1494 dp->dad_na_icount++; 1495 mutex_exit(&nd6_dad_lock); 1496 1497 /* remove the address. */ 1498 nd6_dad_duplicated(ifa); 1499 } 1500
Indexes created Sat Sep 27 14:09:57 GMT 2025