nd6_nbr.c revision 1.138.6.7
1 /* $NetBSD: nd6_nbr.c,v 1.138.6.7 2019/05/13 09:04:38 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 1.138.6.7 2019/05/13 09:04:38 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 dadq *); 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 pserialize_read_exit(s); 464 src = hsrc; 465 } else { 466 int error; 467 struct sockaddr_in6 dst_sa; 468 469 pserialize_read_exit(s); 470 471 sockaddr_in6_init(&dst_sa, &ip6->ip6_dst, 0, 0, 0); 472 473 error = in6_selectsrc(&dst_sa, NULL, 474 NULL, &ro, NULL, NULL, NULL, &src_in); 475 if (error != 0) { 476 char ip6buf[INET6_ADDRSTRLEN]; 477 nd6log(LOG_DEBUG, "source can't be " 478 "determined: dst=%s, error=%d\n", 479 IN6_PRINT(ip6buf, &dst_sa.sin6_addr), 480 error); 481 pserialize_read_exit(s); 482 goto bad; 483 } 484 src = &src_in; 485 } 486 } else { 487 /* 488 * Source address for DAD packet must always be IPv6 489 * unspecified address. (0::0) 490 * We actually don't have to 0-clear the address (we did it 491 * above), but we do so here explicitly to make the intention 492 * clearer. 493 */ 494 memset(&src_in, 0, sizeof(src_in)); 495 src = &src_in; 496 } 497 ip6->ip6_src = *src; 498 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 499 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 500 nd_ns->nd_ns_code = 0; 501 nd_ns->nd_ns_reserved = 0; 502 nd_ns->nd_ns_target = *taddr6; 503 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 504 505 /* 506 * Add source link-layer address option. 507 * 508 * spec implementation 509 * --- --- 510 * DAD packet MUST NOT do not add the option 511 * there's no link layer address: 512 * impossible do not add the option 513 * there's link layer address: 514 * Multicast NS MUST add one add the option 515 * Unicast NS SHOULD add one add the option 516 */ 517 if (!dad && (mac = nd6_ifptomac(ifp))) { 518 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 519 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 520 /* 8 byte alignments... */ 521 optlen = (optlen + 7) & ~7; 522 523 m->m_pkthdr.len += optlen; 524 m->m_len += optlen; 525 icmp6len += optlen; 526 memset((void *)nd_opt, 0, optlen); 527 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 528 nd_opt->nd_opt_len = optlen >> 3; 529 memcpy((void *)(nd_opt + 1), mac, ifp->if_addrlen); 530 } 531 532 ip6->ip6_plen = htons((u_int16_t)icmp6len); 533 nd_ns->nd_ns_cksum = 0; 534 nd_ns->nd_ns_cksum = 535 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 536 537 ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL, NULL); 538 icmp6_ifstat_inc(ifp, ifs6_out_msg); 539 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 540 ICMP6_STATINC(ICMP6_STAT_OUTHIST + ND_NEIGHBOR_SOLICIT); 541 542 rtcache_free(&ro); 543 return; 544 545 bad: 546 rtcache_free(&ro); 547 m_freem(m); 548 return; 549 } 550 551 /* 552 * Neighbor advertisement input handling. 553 * 554 * Based on RFC 2461 555 * Based on RFC 2462 (duplicate address detection) 556 * 557 * the following items are not implemented yet: 558 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 559 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 560 */ 561 void 562 nd6_na_input(struct mbuf *m, int off, int icmp6len) 563 { 564 struct ifnet *ifp; 565 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 566 struct nd_neighbor_advert *nd_na; 567 struct in6_addr saddr6 = ip6->ip6_src; 568 struct in6_addr daddr6 = ip6->ip6_dst; 569 struct in6_addr taddr6; 570 int flags; 571 int is_router; 572 int is_solicited; 573 int is_override; 574 char *lladdr = NULL; 575 int lladdrlen = 0; 576 struct ifaddr *ifa; 577 struct llentry *ln = NULL; 578 union nd_opts ndopts; 579 struct sockaddr_in6 ssin6; 580 int rt_announce; 581 bool checklink = false; 582 struct psref psref; 583 struct psref psref_ia; 584 char ip6buf[INET6_ADDRSTRLEN], ip6buf2[INET6_ADDRSTRLEN]; 585 586 ifp = m_get_rcvif_psref(m, &psref); 587 if (ifp == NULL) 588 goto freeit; 589 590 if (ip6->ip6_hlim != 255) { 591 nd6log(LOG_ERR, 592 "invalid hlim (%d) from %s to %s on %s\n", 593 ip6->ip6_hlim, IN6_PRINT(ip6buf, &ip6->ip6_src), 594 IN6_PRINT(ip6buf2, &ip6->ip6_dst), if_name(ifp)); 595 goto bad; 596 } 597 598 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 599 if (nd_na == NULL) { 600 m_put_rcvif_psref(ifp, &psref); 601 ICMP6_STATINC(ICMP6_STAT_TOOSHORT); 602 return; 603 } 604 605 flags = nd_na->nd_na_flags_reserved; 606 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 607 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 608 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 609 610 taddr6 = nd_na->nd_na_target; 611 if (in6_setscope(&taddr6, ifp, NULL)) { 612 goto bad; 613 } 614 615 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 616 nd6log(LOG_ERR, "invalid target address %s\n", 617 IN6_PRINT(ip6buf, &taddr6)); 618 goto bad; 619 } 620 if (is_solicited && IN6_IS_ADDR_MULTICAST(&daddr6)) { 621 nd6log(LOG_ERR, "a solicited adv is multicasted\n"); 622 goto bad; 623 } 624 625 icmp6len -= sizeof(*nd_na); 626 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 627 if (nd6_options(&ndopts) < 0) { 628 nd6log(LOG_INFO, "invalid ND option, ignored\n"); 629 /* nd6_options have incremented stats */ 630 goto freeit; 631 } 632 633 if (ndopts.nd_opts_tgt_lladdr != NULL) { 634 struct ifnet *ifp_ll; 635 struct psref psref_ll; 636 637 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 638 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 639 640 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 641 nd6log(LOG_INFO, "lladdrlen mismatch for %s " 642 "(if %d, NA packet %d)\n", IN6_PRINT(ip6buf, &taddr6), 643 ifp->if_addrlen, lladdrlen - 2); 644 goto bad; 645 } 646 647 ifp_ll = if_get_bylla(lladdr, ifp->if_addrlen, &psref_ll); 648 if (ifp_ll != NULL) { 649 /* it's from me, ignore it. */ 650 if_put(ifp_ll, &psref_ll); 651 goto freeit; 652 } 653 } 654 655 ifa = (struct ifaddr *)in6ifa_ifpwithaddr_psref(ifp, &taddr6, &psref_ia); 656 657 /* 658 * Target address matches one of my interface address. 659 * 660 * If my address is tentative, this means that there's somebody 661 * already using the same address as mine. This indicates DAD failure. 662 * This is defined in RFC 2462. 663 * 664 * Otherwise, process as defined in RFC 2461. 665 */ 666 if (ifa 667 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) 668 { 669 nd6_dad_na_input(ifa); 670 ifa_release(ifa, &psref_ia); 671 ifa = NULL; 672 goto freeit; 673 } 674 675 /* Just for safety, maybe unnecessary. */ 676 if (ifa) { 677 log(LOG_ERR, 678 "nd6_na_input: duplicate IP6 address %s\n", 679 IN6_PRINT(ip6buf, &taddr6)); 680 ifa_release(ifa, &psref_ia); 681 ifa = NULL; 682 goto freeit; 683 } 684 685 /* 686 * Make sure the source address is from a neighbor's address. 687 */ 688 sockaddr_in6_init(&ssin6, &saddr6, 0, 0, 0); 689 if (nd6_is_addr_neighbor(&ssin6, ifp) == 0) { 690 nd6log(LOG_INFO, "ND packet from non-neighbor %s on %s\n", 691 IN6_PRINT(ip6buf, &saddr6), if_name(ifp)); 692 goto bad; 693 } 694 695 /* 696 * If no neighbor cache entry is found, NA SHOULD silently be 697 * discarded. 698 */ 699 ln = nd6_lookup(&taddr6, ifp, true); 700 if (ln == NULL) 701 goto freeit; 702 703 rt_announce = 0; 704 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 705 /* 706 * If the link-layer has address, and no lladdr option came, 707 * discard the packet. 708 */ 709 if (ifp->if_addrlen && !lladdr) 710 goto freeit; 711 712 /* 713 * Record link-layer address, and update the state. 714 */ 715 memcpy(&ln->ll_addr, lladdr, ifp->if_addrlen); 716 ln->la_flags |= LLE_VALID; 717 rt_announce = 1; 718 if (is_solicited) { 719 ln->ln_state = ND6_LLINFO_REACHABLE; 720 ln->ln_byhint = 0; 721 if (!ND6_LLINFO_PERMANENT(ln)) { 722 nd6_llinfo_settimer(ln, 723 ND_IFINFO(ln->lle_tbl->llt_ifp)->reachable * hz); 724 } 725 } else { 726 ln->ln_state = ND6_LLINFO_STALE; 727 nd6_llinfo_settimer(ln, nd6_gctimer * hz); 728 } 729 if ((ln->ln_router = is_router) != 0) { 730 /* 731 * This means a router's state has changed from 732 * non-reachable to probably reachable, and might 733 * affect the status of associated prefixes.. 734 */ 735 checklink = true; 736 } 737 } else { 738 int llchange; 739 740 /* 741 * Check if the link-layer address has changed or not. 742 */ 743 if (lladdr == NULL) 744 llchange = 0; 745 else { 746 if (ln->la_flags & LLE_VALID) { 747 if (memcmp(lladdr, &ln->ll_addr, ifp->if_addrlen)) 748 llchange = rt_announce = 1; 749 else 750 llchange = 0; 751 } else 752 llchange = rt_announce = 1; 753 } 754 755 /* 756 * This is VERY complex. Look at it with care. 757 * 758 * override solicit lladdr llchange action 759 * (L: record lladdr) 760 * 761 * 0 0 n -- (2c) 762 * 0 0 y n (2b) L 763 * 0 0 y y (1) REACHABLE->STALE 764 * 0 1 n -- (2c) *->REACHABLE 765 * 0 1 y n (2b) L *->REACHABLE 766 * 0 1 y y (1) REACHABLE->STALE 767 * 1 0 n -- (2a) 768 * 1 0 y n (2a) L 769 * 1 0 y y (2a) L *->STALE 770 * 1 1 n -- (2a) *->REACHABLE 771 * 1 1 y n (2a) L *->REACHABLE 772 * 1 1 y y (2a) L *->REACHABLE 773 */ 774 if (!is_override && lladdr != NULL && llchange) { /* (1) */ 775 /* 776 * If state is REACHABLE, make it STALE. 777 * no other updates should be done. 778 */ 779 if (ln->ln_state == ND6_LLINFO_REACHABLE) { 780 ln->ln_state = ND6_LLINFO_STALE; 781 nd6_llinfo_settimer(ln, nd6_gctimer * hz); 782 } 783 goto freeit; 784 } else if (is_override /* (2a) */ 785 || (!is_override && lladdr != NULL && !llchange) /* (2b) */ 786 || lladdr == NULL) { /* (2c) */ 787 /* 788 * Update link-local address, if any. 789 */ 790 if (lladdr != NULL) { 791 memcpy(&ln->ll_addr, lladdr, ifp->if_addrlen); 792 ln->la_flags |= LLE_VALID; 793 } 794 795 /* 796 * If solicited, make the state REACHABLE. 797 * If not solicited and the link-layer address was 798 * changed, make it STALE. 799 */ 800 if (is_solicited) { 801 ln->ln_state = ND6_LLINFO_REACHABLE; 802 ln->ln_byhint = 0; 803 if (!ND6_LLINFO_PERMANENT(ln)) { 804 nd6_llinfo_settimer(ln, 805 ND_IFINFO(ifp)->reachable * hz); 806 } 807 } else { 808 if (lladdr && llchange) { 809 ln->ln_state = ND6_LLINFO_STALE; 810 nd6_llinfo_settimer(ln, 811 nd6_gctimer * hz); 812 } 813 } 814 } 815 816 if (ln->ln_router && !is_router) { 817 /* 818 * The peer dropped the router flag. 819 * Remove the sender from the Default Router List and 820 * update the Destination Cache entries. 821 */ 822 struct nd_defrouter *dr; 823 const struct in6_addr *in6; 824 825 in6 = &ln->r_l3addr.addr6; 826 827 ND6_WLOCK(); 828 dr = nd6_defrouter_lookup(in6, ln->lle_tbl->llt_ifp); 829 if (dr) 830 nd6_defrtrlist_del(dr, NULL); 831 else if (!ip6_forwarding) { 832 /* 833 * Even if the neighbor is not in the default 834 * router list, the neighbor may be used 835 * as a next hop for some destinations 836 * (e.g. redirect case). So we must 837 * call nd6_rt_flush explicitly. 838 */ 839 nd6_rt_flush(&ip6->ip6_src, ln->lle_tbl->llt_ifp); 840 } 841 ND6_UNLOCK(); 842 } 843 ln->ln_router = is_router; 844 } 845 /* 846 * XXX: does this matter? 847 * rt->rt_flags &= ~RTF_REJECT; 848 */ 849 ln->ln_asked = 0; 850 nd6_llinfo_release_pkts(ln, ifp); 851 /* FIXME */ 852 #if 0 853 if (rt_announce) /* tell user process about any new lladdr */ 854 rt_newmsg(RTM_CHANGE, rt); 855 #endif 856 857 freeit: 858 if (ln != NULL) 859 LLE_WUNLOCK(ln); 860 861 if (checklink) { 862 ND6_WLOCK(); 863 nd6_pfxlist_onlink_check(); 864 ND6_UNLOCK(); 865 } 866 867 m_put_rcvif_psref(ifp, &psref); 868 m_freem(m); 869 return; 870 871 bad: 872 if (ln != NULL) 873 LLE_WUNLOCK(ln); 874 875 ICMP6_STATINC(ICMP6_STAT_BADNA); 876 m_put_rcvif_psref(ifp, &psref); 877 m_freem(m); 878 } 879 880 /* 881 * Neighbor advertisement output handling. 882 * 883 * Based on RFC 2461 884 * 885 * the following items are not implemented yet: 886 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 887 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 888 */ 889 void 890 nd6_na_output( 891 struct ifnet *ifp, 892 const struct in6_addr *daddr6_0, 893 const struct in6_addr *taddr6, 894 u_long flags, 895 int tlladdr, /* 1 if include target link-layer address */ 896 const struct sockaddr *sdl0) /* sockaddr_dl (= proxy NA) or NULL */ 897 { 898 struct mbuf *m; 899 struct ip6_hdr *ip6; 900 struct nd_neighbor_advert *nd_na; 901 struct ip6_moptions im6o; 902 struct sockaddr *dst; 903 union { 904 struct sockaddr dst; 905 struct sockaddr_in6 dst6; 906 } u; 907 struct in6_addr daddr6; 908 int icmp6len, maxlen, error; 909 const void *mac; 910 struct route ro; 911 912 mac = NULL; 913 memset(&ro, 0, sizeof(ro)); 914 915 daddr6 = *daddr6_0; /* make a local copy for modification */ 916 917 /* estimate the size of message */ 918 maxlen = sizeof(*ip6) + sizeof(*nd_na); 919 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 920 KASSERTMSG(max_linkhdr + maxlen < MCLBYTES, 921 "max_linkhdr + maxlen >= MCLBYTES (%d + %d >= %d)", 922 max_linkhdr, maxlen, MCLBYTES); 923 924 MGETHDR(m, M_DONTWAIT, MT_DATA); 925 if (m && max_linkhdr + maxlen >= MHLEN) { 926 MCLGET(m, M_DONTWAIT); 927 if ((m->m_flags & M_EXT) == 0) { 928 m_free(m); 929 m = NULL; 930 } 931 } 932 if (m == NULL) 933 return; 934 m_reset_rcvif(m); 935 936 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 937 m->m_flags |= M_MCAST; 938 im6o.im6o_multicast_if_index = if_get_index(ifp); 939 im6o.im6o_multicast_hlim = 255; 940 im6o.im6o_multicast_loop = 0; 941 } 942 943 icmp6len = sizeof(*nd_na); 944 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 945 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 946 947 /* fill neighbor advertisement packet */ 948 ip6 = mtod(m, struct ip6_hdr *); 949 ip6->ip6_flow = 0; 950 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 951 ip6->ip6_vfc |= IPV6_VERSION; 952 ip6->ip6_nxt = IPPROTO_ICMPV6; 953 ip6->ip6_hlim = 255; 954 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 955 /* reply to DAD */ 956 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 957 daddr6.s6_addr16[1] = 0; 958 daddr6.s6_addr32[1] = 0; 959 daddr6.s6_addr32[2] = 0; 960 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 961 if (in6_setscope(&daddr6, ifp, NULL)) 962 goto bad; 963 964 flags &= ~ND_NA_FLAG_SOLICITED; 965 } 966 ip6->ip6_dst = daddr6; 967 sockaddr_in6_init(&u.dst6, &daddr6, 0, 0, 0); 968 dst = &u.dst; 969 if (rtcache_setdst(&ro, dst) != 0) 970 goto bad; 971 972 /* 973 * Select a source whose scope is the same as that of the dest. 974 */ 975 error = in6_selectsrc(satosin6(dst), NULL, NULL, &ro, NULL, NULL, NULL, 976 &ip6->ip6_src); 977 if (error != 0) { 978 char ip6buf[INET6_ADDRSTRLEN]; 979 nd6log(LOG_DEBUG, "source can't be " 980 "determined: dst=%s, error=%d\n", 981 IN6_PRINT(ip6buf, &satocsin6(dst)->sin6_addr), error); 982 goto bad; 983 } 984 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 985 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 986 nd_na->nd_na_code = 0; 987 nd_na->nd_na_target = *taddr6; 988 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 989 990 /* 991 * "tlladdr" indicates NS's condition for adding tlladdr or not. 992 * see nd6_ns_input() for details. 993 * Basically, if NS packet is sent to unicast/anycast addr, 994 * target lladdr option SHOULD NOT be included. 995 */ 996 if (tlladdr) { 997 /* 998 * sdl0 != NULL indicates proxy NA. If we do proxy, use 999 * lladdr in sdl0. If we are not proxying (sending NA for 1000 * my address) use lladdr configured for the interface. 1001 */ 1002 if (sdl0 == NULL) 1003 mac = nd6_ifptomac(ifp); 1004 else if (sdl0->sa_family == AF_LINK) { 1005 const struct sockaddr_dl *sdl; 1006 sdl = satocsdl(sdl0); 1007 if (sdl->sdl_alen == ifp->if_addrlen) 1008 mac = CLLADDR(sdl); 1009 } 1010 } 1011 if (tlladdr && mac) { 1012 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1013 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1014 1015 /* roundup to 8 bytes alignment! */ 1016 optlen = (optlen + 7) & ~7; 1017 1018 m->m_pkthdr.len += optlen; 1019 m->m_len += optlen; 1020 icmp6len += optlen; 1021 memset((void *)nd_opt, 0, optlen); 1022 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1023 nd_opt->nd_opt_len = optlen >> 3; 1024 memcpy((void *)(nd_opt + 1), mac, ifp->if_addrlen); 1025 } else 1026 flags &= ~ND_NA_FLAG_OVERRIDE; 1027 1028 ip6->ip6_plen = htons((u_int16_t)icmp6len); 1029 nd_na->nd_na_flags_reserved = flags; 1030 nd_na->nd_na_cksum = 0; 1031 nd_na->nd_na_cksum = 1032 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1033 1034 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL); 1035 1036 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1037 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1038 ICMP6_STATINC(ICMP6_STAT_OUTHIST + ND_NEIGHBOR_ADVERT); 1039 1040 rtcache_free(&ro); 1041 return; 1042 1043 bad: 1044 rtcache_free(&ro); 1045 m_freem(m); 1046 return; 1047 } 1048 1049 const void * 1050 nd6_ifptomac(const struct ifnet *ifp) 1051 { 1052 switch (ifp->if_type) { 1053 case IFT_ARCNET: 1054 case IFT_ETHER: 1055 case IFT_FDDI: 1056 case IFT_IEEE1394: 1057 case IFT_PROPVIRTUAL: 1058 case IFT_CARP: 1059 case IFT_L2VLAN: 1060 case IFT_IEEE80211: 1061 return CLLADDR(ifp->if_sadl); 1062 default: 1063 return NULL; 1064 } 1065 } 1066 1067 TAILQ_HEAD(dadq_head, dadq); 1068 struct dadq { 1069 TAILQ_ENTRY(dadq) dad_list; 1070 struct ifaddr *dad_ifa; 1071 int dad_count; /* max NS to send */ 1072 int dad_ns_tcount; /* # of trials to send NS */ 1073 int dad_ns_ocount; /* NS sent so far */ 1074 int dad_ns_icount; 1075 int dad_na_icount; 1076 struct callout dad_timer_ch; 1077 }; 1078 1079 static struct dadq_head dadq; 1080 static int dad_init = 0; 1081 static kmutex_t nd6_dad_lock; 1082 1083 static struct dadq * 1084 nd6_dad_find(struct ifaddr *ifa) 1085 { 1086 struct dadq *dp; 1087 1088 KASSERT(mutex_owned(&nd6_dad_lock)); 1089 1090 TAILQ_FOREACH(dp, &dadq, dad_list) { 1091 if (dp->dad_ifa == ifa) 1092 return dp; 1093 } 1094 return NULL; 1095 } 1096 1097 static void 1098 nd6_dad_starttimer(struct dadq *dp, int ticks) 1099 { 1100 1101 callout_reset(&dp->dad_timer_ch, ticks, 1102 (void (*)(void *))nd6_dad_timer, dp); 1103 } 1104 1105 static void 1106 nd6_dad_stoptimer(struct dadq *dp) 1107 { 1108 1109 KASSERT(mutex_owned(&nd6_dad_lock)); 1110 1111 TAILQ_REMOVE(&dadq, dp, dad_list); 1112 /* Tell the timer that dp is being destroyed. */ 1113 dp->dad_ifa = NULL; 1114 callout_halt(&dp->dad_timer_ch, &nd6_dad_lock); 1115 } 1116 1117 static void 1118 nd6_dad_destroytimer(struct dadq *dp) 1119 { 1120 1121 KASSERT(dp->dad_ifa == NULL); 1122 callout_destroy(&dp->dad_timer_ch); 1123 kmem_intr_free(dp, sizeof(*dp)); 1124 } 1125 1126 /* 1127 * Start Duplicate Address Detection (DAD) for specified interface address. 1128 * 1129 * Note that callout is used when xtick > 0 and not when xtick == 0. 1130 * 1131 * xtick: minimum delay ticks for IFF_UP event 1132 */ 1133 void 1134 nd6_dad_start(struct ifaddr *ifa, int xtick) 1135 { 1136 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1137 struct dadq *dp; 1138 char ip6buf[INET6_ADDRSTRLEN]; 1139 1140 if (!dad_init) { 1141 TAILQ_INIT(&dadq); 1142 mutex_init(&nd6_dad_lock, MUTEX_DEFAULT, IPL_NONE); 1143 dad_init++; 1144 } 1145 1146 /* 1147 * If we don't need DAD, don't do it. 1148 * There are several cases: 1149 * - DAD is disabled (ip6_dad_count == 0) 1150 * - the interface address is anycast 1151 */ 1152 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1153 log(LOG_DEBUG, 1154 "nd6_dad_start: called with non-tentative address " 1155 "%s(%s)\n", 1156 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1157 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1158 return; 1159 } 1160 if (ia->ia6_flags & IN6_IFF_ANYCAST || !ip6_dad_count) { 1161 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1162 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1163 return; 1164 } 1165 KASSERT(ifa->ifa_ifp != NULL); 1166 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) 1167 return; 1168 1169 dp = kmem_intr_alloc(sizeof(*dp), KM_NOSLEEP); 1170 1171 mutex_enter(&nd6_dad_lock); 1172 if (nd6_dad_find(ifa) != NULL) { 1173 mutex_exit(&nd6_dad_lock); 1174 /* DAD already in progress */ 1175 if (dp != NULL) 1176 kmem_intr_free(dp, sizeof(*dp)); 1177 return; 1178 } 1179 1180 if (dp == NULL) { 1181 mutex_exit(&nd6_dad_lock); 1182 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1183 "%s(%s)\n", 1184 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1185 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1186 return; 1187 } 1188 1189 /* 1190 * Send NS packet for DAD, ip6_dad_count times. 1191 * Note that we must delay the first transmission, if this is the 1192 * first packet to be sent from the interface after interface 1193 * (re)initialization. 1194 */ 1195 callout_init(&dp->dad_timer_ch, CALLOUT_MPSAFE); 1196 dp->dad_ifa = ifa; 1197 ifaref(ifa); /* just for safety */ 1198 dp->dad_count = ip6_dad_count; 1199 dp->dad_ns_icount = dp->dad_na_icount = 0; 1200 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1201 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list); 1202 1203 nd6log(LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1204 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr)); 1205 1206 if (xtick == 0) { 1207 nd6_dad_ns_output(dp, ifa); 1208 nd6_dad_starttimer(dp, 1209 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1210 } else 1211 nd6_dad_starttimer(dp, xtick); 1212 mutex_exit(&nd6_dad_lock); 1213 } 1214 1215 /* 1216 * terminate DAD unconditionally. used for address removals. 1217 */ 1218 void 1219 nd6_dad_stop(struct ifaddr *ifa) 1220 { 1221 struct dadq *dp; 1222 1223 if (!dad_init) 1224 return; 1225 1226 mutex_enter(&nd6_dad_lock); 1227 dp = nd6_dad_find(ifa); 1228 if (dp == NULL) { 1229 mutex_exit(&nd6_dad_lock); 1230 /* DAD wasn't started yet */ 1231 return; 1232 } 1233 1234 /* Prevent the timer from running anymore. */ 1235 nd6_dad_stoptimer(dp); 1236 1237 mutex_exit(&nd6_dad_lock); 1238 1239 nd6_dad_destroytimer(dp); 1240 ifafree(ifa); 1241 } 1242 1243 static void 1244 nd6_dad_timer(struct dadq *dp) 1245 { 1246 struct ifaddr *ifa; 1247 struct in6_ifaddr *ia; 1248 int duplicate = 0; 1249 char ip6buf[INET6_ADDRSTRLEN]; 1250 bool need_free = false; 1251 1252 KERNEL_LOCK_UNLESS_NET_MPSAFE(); 1253 mutex_enter(&nd6_dad_lock); 1254 1255 ifa = dp->dad_ifa; 1256 if (ifa == NULL) { 1257 /* dp is being destroyed by someone. Do nothing. */ 1258 goto done; 1259 } 1260 1261 ia = (struct in6_ifaddr *)ifa; 1262 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1263 log(LOG_ERR, "nd6_dad_timer: called with duplicate address " 1264 "%s(%s)\n", 1265 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1266 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1267 goto done; 1268 } 1269 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1270 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1271 "%s(%s)\n", 1272 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1273 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1274 goto done; 1275 } 1276 1277 /* timeouted with IFF_{RUNNING,UP} check */ 1278 if (dp->dad_ns_tcount > dad_maxtry) { 1279 nd6log(LOG_INFO, "%s: could not run DAD, driver problem?\n", 1280 if_name(ifa->ifa_ifp)); 1281 1282 nd6_dad_stoptimer(dp); 1283 need_free = true; 1284 goto done; 1285 } 1286 1287 /* Need more checks? */ 1288 if (dp->dad_ns_ocount < dp->dad_count) { 1289 /* 1290 * We have more NS to go. Send NS packet for DAD. 1291 */ 1292 nd6_dad_ns_output(dp, ifa); 1293 nd6_dad_starttimer(dp, 1294 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000); 1295 } else { 1296 /* 1297 * We have transmitted sufficient number of DAD packets. 1298 * See what we've got. 1299 */ 1300 if (dp->dad_na_icount) { 1301 /* 1302 * the check is in nd6_dad_na_input(), 1303 * but just in case 1304 */ 1305 duplicate++; 1306 } 1307 1308 if (dp->dad_ns_icount) { 1309 /* We've seen NS, means DAD has failed. */ 1310 duplicate++; 1311 } 1312 1313 if (duplicate) { 1314 nd6_dad_duplicated(dp); 1315 nd6_dad_stoptimer(dp); 1316 need_free = true; 1317 } else { 1318 /* 1319 * We are done with DAD. No NA came, no NS came. 1320 * No duplicate address found. 1321 */ 1322 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1323 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1324 1325 nd6log(LOG_DEBUG, 1326 "%s: DAD complete for %s - no duplicates found\n", 1327 if_name(ifa->ifa_ifp), 1328 IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr)); 1329 1330 nd6_dad_stoptimer(dp); 1331 need_free = true; 1332 } 1333 } 1334 done: 1335 mutex_exit(&nd6_dad_lock); 1336 1337 if (need_free) { 1338 nd6_dad_destroytimer(dp); 1339 KASSERT(ifa != NULL); 1340 ifafree(ifa); 1341 } 1342 1343 KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); 1344 } 1345 1346 static void 1347 nd6_dad_duplicated(struct dadq *dp) 1348 { 1349 struct ifaddr *ifa = dp->dad_ifa; 1350 struct in6_ifaddr *ia; 1351 struct ifnet *ifp; 1352 char ip6buf[INET6_ADDRSTRLEN]; 1353 1354 KASSERT(mutex_owned(&nd6_dad_lock)); 1355 KASSERT(ifa != NULL); 1356 1357 ifp = ifa->ifa_ifp; 1358 ia = (struct in6_ifaddr *)ifa; 1359 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1360 "NS in/out=%d/%d, NA in=%d\n", 1361 if_name(ifp), IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr), 1362 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount); 1363 1364 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1365 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1366 1367 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1368 if_name(ifp), IN6_PRINT(ip6buf, &ia->ia_addr.sin6_addr)); 1369 log(LOG_ERR, "%s: manual intervention required\n", 1370 if_name(ifp)); 1371 1372 /* Inform the routing socket that DAD has completed */ 1373 rt_newaddrmsg(RTM_NEWADDR, ifa, 0, NULL); 1374 1375 /* 1376 * If the address is a link-local address formed from an interface 1377 * identifier based on the hardware address which is supposed to be 1378 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1379 * operation on the interface SHOULD be disabled. 1380 * [rfc2462bis-03 Section 5.4.5] 1381 */ 1382 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1383 struct in6_addr in6; 1384 1385 /* 1386 * To avoid over-reaction, we only apply this logic when we are 1387 * very sure that hardware addresses are supposed to be unique. 1388 */ 1389 switch (ifp->if_type) { 1390 case IFT_ETHER: 1391 case IFT_FDDI: 1392 case IFT_ATM: 1393 case IFT_IEEE1394: 1394 #ifdef IFT_IEEE80211 1395 case IFT_IEEE80211: 1396 #endif 1397 in6 = ia->ia_addr.sin6_addr; 1398 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1399 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1400 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1401 log(LOG_ERR, "%s: possible hardware address " 1402 "duplication detected, disable IPv6\n", 1403 if_name(ifp)); 1404 } 1405 break; 1406 } 1407 } 1408 } 1409 1410 static void 1411 nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa) 1412 { 1413 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1414 struct ifnet *ifp = ifa->ifa_ifp; 1415 1416 dp->dad_ns_tcount++; 1417 if ((ifp->if_flags & IFF_UP) == 0) { 1418 #if 0 1419 printf("%s: interface down?\n", if_name(ifp)); 1420 #endif 1421 return; 1422 } 1423 if ((ifp->if_flags & IFF_RUNNING) == 0) { 1424 #if 0 1425 printf("%s: interface not running?\n", if_name(ifp)); 1426 #endif 1427 return; 1428 } 1429 1430 dp->dad_ns_tcount = 0; 1431 dp->dad_ns_ocount++; 1432 nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1); 1433 } 1434 1435 static void 1436 nd6_dad_ns_input(struct ifaddr *ifa) 1437 { 1438 struct in6_ifaddr *ia; 1439 const struct in6_addr *taddr6; 1440 struct dadq *dp; 1441 int duplicate; 1442 1443 if (ifa == NULL) 1444 panic("ifa == NULL in nd6_dad_ns_input"); 1445 1446 ia = (struct in6_ifaddr *)ifa; 1447 taddr6 = &ia->ia_addr.sin6_addr; 1448 duplicate = 0; 1449 1450 mutex_enter(&nd6_dad_lock); 1451 dp = nd6_dad_find(ifa); 1452 1453 /* Quickhack - completely ignore DAD NS packets */ 1454 if (dad_ignore_ns) { 1455 char ip6buf[INET6_ADDRSTRLEN]; 1456 nd6log(LOG_INFO, "ignoring DAD NS packet for " 1457 "address %s(%s)\n", IN6_PRINT(ip6buf, taddr6), 1458 if_name(ifa->ifa_ifp)); 1459 return; 1460 } 1461 1462 /* 1463 * if I'm yet to start DAD, someone else started using this address 1464 * first. I have a duplicate and you win. 1465 */ 1466 if (dp == NULL || dp->dad_ns_ocount == 0) 1467 duplicate++; 1468 1469 /* XXX more checks for loopback situation - see nd6_dad_timer too */ 1470 1471 if (duplicate) { 1472 if (dp) { 1473 nd6_dad_duplicated(dp); 1474 nd6_dad_stoptimer(dp); 1475 } 1476 } else { 1477 /* 1478 * not sure if I got a duplicate. 1479 * increment ns count and see what happens. 1480 */ 1481 if (dp) 1482 dp->dad_ns_icount++; 1483 } 1484 mutex_exit(&nd6_dad_lock); 1485 1486 if (duplicate && dp) { 1487 nd6_dad_destroytimer(dp); 1488 ifafree(ifa); 1489 } 1490 } 1491 1492 static void 1493 nd6_dad_na_input(struct ifaddr *ifa) 1494 { 1495 struct dadq *dp; 1496 1497 KASSERT(ifa != NULL); 1498 1499 mutex_enter(&nd6_dad_lock); 1500 1501 dp = nd6_dad_find(ifa); 1502 if (dp == NULL) { 1503 mutex_exit(&nd6_dad_lock); 1504 return; 1505 } 1506 1507 dp->dad_na_icount++; 1508 1509 /* remove the address. */ 1510 nd6_dad_duplicated(dp); 1511 nd6_dad_stoptimer(dp); 1512 1513 mutex_exit(&nd6_dad_lock); 1514 1515 nd6_dad_destroytimer(dp); 1516 ifafree(ifa); 1517 } 1518
Indexes created Thu Oct 23 22:10:10 GMT 2025