nd6_nbr.c revision 299014
1/*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $ 30 */ 31 32#include <sys/cdefs.h> 33__FBSDID("$FreeBSD: stable/10/sys/netinet6/nd6_nbr.c 299014 2016-05-03 23:46:01Z markj $"); 34 35#include "opt_inet.h" 36#include "opt_inet6.h" 37#include "opt_ipsec.h" 38#include "opt_mpath.h" 39 40#include <sys/param.h> 41#include <sys/systm.h> 42#include <sys/malloc.h> 43#include <sys/libkern.h> 44#include <sys/lock.h> 45#include <sys/rwlock.h> 46#include <sys/mbuf.h> 47#include <sys/socket.h> 48#include <sys/sockio.h> 49#include <sys/time.h> 50#include <sys/kernel.h> 51#include <sys/errno.h> 52#include <sys/sysctl.h> 53#include <sys/syslog.h> 54#include <sys/queue.h> 55#include <sys/callout.h> 56#include <sys/refcount.h> 57 58#include <net/if.h> 59#include <net/if_types.h> 60#include <net/if_dl.h> 61#include <net/if_var.h> 62#include <net/route.h> 63#ifdef RADIX_MPATH 64#include <net/radix_mpath.h> 65#endif 66#include <net/vnet.h> 67 68#include <netinet/in.h> 69#include <netinet/in_var.h> 70#include <net/if_llatbl.h> 71#define L3_ADDR_SIN6(le) ((struct sockaddr_in6 *) L3_ADDR(le)) 72#include <netinet6/in6_var.h> 73#include <netinet6/in6_ifattach.h> 74#include <netinet/ip6.h> 75#include <netinet6/ip6_var.h> 76#include <netinet6/scope6_var.h> 77#include <netinet6/nd6.h> 78#include <netinet/icmp6.h> 79#include <netinet/ip_carp.h> 80#include <netinet6/send.h> 81 82#define SDL(s) ((struct sockaddr_dl *)s) 83 84struct dadq; 85static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *); 86static void nd6_dad_add(struct dadq *dp); 87static void nd6_dad_del(struct dadq *dp); 88static void nd6_dad_rele(struct dadq *); 89static void nd6_dad_starttimer(struct dadq *, int, int); 90static void nd6_dad_stoptimer(struct dadq *); 91static void nd6_dad_timer(struct dadq *); 92static void nd6_dad_duplicated(struct ifaddr *, struct dadq *); 93static void nd6_dad_ns_output(struct dadq *); 94static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *); 95static void nd6_dad_na_input(struct ifaddr *); 96static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *, 97 const struct in6_addr *, u_long, int, struct sockaddr *, u_int); 98static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *, 99 const struct in6_addr *, struct llentry *, uint8_t *, u_int); 100 101static VNET_DEFINE(int, dad_enhanced) = 1; 102#define V_dad_enhanced VNET(dad_enhanced) 103 104SYSCTL_DECL(_net_inet6_ip6); 105SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW, 106 &VNET_NAME(dad_enhanced), 0, 107 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD."); 108 109static VNET_DEFINE(int, dad_maxtry) = 15; /* max # of *tries* to 110 transmit DAD packet */ 111#define V_dad_maxtry VNET(dad_maxtry) 112 113/* 114 * Input a Neighbor Solicitation Message. 115 * 116 * Based on RFC 2461 117 * Based on RFC 2462 (duplicate address detection) 118 */ 119void 120nd6_ns_input(struct mbuf *m, int off, int icmp6len) 121{ 122 struct ifnet *ifp = m->m_pkthdr.rcvif; 123 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 124 struct nd_neighbor_solicit *nd_ns; 125 struct in6_addr saddr6 = ip6->ip6_src; 126 struct in6_addr daddr6 = ip6->ip6_dst; 127 struct in6_addr taddr6; 128 struct in6_addr myaddr6; 129 char *lladdr = NULL; 130 struct ifaddr *ifa = NULL; 131 int lladdrlen = 0; 132 int anycast = 0, proxy = 0, tentative = 0; 133 int tlladdr; 134 int rflag; 135 union nd_opts ndopts; 136 struct sockaddr_dl proxydl; 137 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 138 139 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0; 140 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif) 141 rflag = 0; 142#ifndef PULLDOWN_TEST 143 IP6_EXTHDR_CHECK(m, off, icmp6len,); 144 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off); 145#else 146 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len); 147 if (nd_ns == NULL) { 148 ICMP6STAT_INC(icp6s_tooshort); 149 return; 150 } 151#endif 152 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */ 153 taddr6 = nd_ns->nd_ns_target; 154 if (in6_setscope(&taddr6, ifp, NULL) != 0) 155 goto bad; 156 157 if (ip6->ip6_hlim != 255) { 158 nd6log((LOG_ERR, 159 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n", 160 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 161 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 162 goto bad; 163 } 164 165 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 166 /* dst has to be a solicited node multicast address. */ 167 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL && 168 /* don't check ifindex portion */ 169 daddr6.s6_addr32[1] == 0 && 170 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE && 171 daddr6.s6_addr8[12] == 0xff) { 172 ; /* good */ 173 } else { 174 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 175 "(wrong ip6 dst)\n")); 176 goto bad; 177 } 178 } else if (!V_nd6_onlink_ns_rfc4861) { 179 struct sockaddr_in6 src_sa6; 180 181 /* 182 * According to recent IETF discussions, it is not a good idea 183 * to accept a NS from an address which would not be deemed 184 * to be a neighbor otherwise. This point is expected to be 185 * clarified in future revisions of the specification. 186 */ 187 bzero(&src_sa6, sizeof(src_sa6)); 188 src_sa6.sin6_family = AF_INET6; 189 src_sa6.sin6_len = sizeof(src_sa6); 190 src_sa6.sin6_addr = saddr6; 191 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) { 192 nd6log((LOG_INFO, "nd6_ns_input: " 193 "NS packet from non-neighbor\n")); 194 goto bad; 195 } 196 } 197 198 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 199 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n")); 200 goto bad; 201 } 202 203 icmp6len -= sizeof(*nd_ns); 204 nd6_option_init(nd_ns + 1, icmp6len, &ndopts); 205 if (nd6_options(&ndopts) < 0) { 206 nd6log((LOG_INFO, 207 "nd6_ns_input: invalid ND option, ignored\n")); 208 /* nd6_options have incremented stats */ 209 goto freeit; 210 } 211 212 if (ndopts.nd_opts_src_lladdr) { 213 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1); 214 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3; 215 } 216 217 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) { 218 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet " 219 "(link-layer address option)\n")); 220 goto bad; 221 } 222 223 /* 224 * Attaching target link-layer address to the NA? 225 * (RFC 2461 7.2.4) 226 * 227 * NS IP dst is unicast/anycast MUST NOT add 228 * NS IP dst is solicited-node multicast MUST add 229 * 230 * In implementation, we add target link-layer address by default. 231 * We do not add one in MUST NOT cases. 232 */ 233 if (!IN6_IS_ADDR_MULTICAST(&daddr6)) 234 tlladdr = 0; 235 else 236 tlladdr = 1; 237 238 /* 239 * Target address (taddr6) must be either: 240 * (1) Valid unicast/anycast address for my receiving interface, 241 * (2) Unicast address for which I'm offering proxy service, or 242 * (3) "tentative" address on which DAD is being performed. 243 */ 244 /* (1) and (3) check. */ 245 if (ifp->if_carp) 246 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 247 else 248 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 249 250 /* (2) check. */ 251 if (ifa == NULL) { 252 struct route_in6 ro; 253 int need_proxy; 254 255 bzero(&ro, sizeof(ro)); 256 ro.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 257 ro.ro_dst.sin6_family = AF_INET6; 258 ro.ro_dst.sin6_addr = taddr6; 259 260 /* Always use the default FIB. */ 261#ifdef RADIX_MPATH 262 rtalloc_mpath_fib((struct route *)&ro, RTF_ANNOUNCE, 263 RT_DEFAULT_FIB); 264#else 265 in6_rtalloc(&ro, RT_DEFAULT_FIB); 266#endif 267 need_proxy = (ro.ro_rt && 268 (ro.ro_rt->rt_flags & RTF_ANNOUNCE) != 0 && 269 ro.ro_rt->rt_gateway->sa_family == AF_LINK); 270 if (ro.ro_rt != NULL) { 271 if (need_proxy) 272 proxydl = *SDL(ro.ro_rt->rt_gateway); 273 RTFREE(ro.ro_rt); 274 } 275 if (need_proxy) { 276 /* 277 * proxy NDP for single entry 278 */ 279 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 280 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST); 281 if (ifa) 282 proxy = 1; 283 } 284 } 285 if (ifa == NULL) { 286 /* 287 * We've got an NS packet, and we don't have that adddress 288 * assigned for us. We MUST silently ignore it. 289 * See RFC2461 7.2.3. 290 */ 291 goto freeit; 292 } 293 myaddr6 = *IFA_IN6(ifa); 294 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST; 295 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE; 296 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED) 297 goto freeit; 298 299 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 300 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s " 301 "(if %d, NS packet %d)\n", 302 ip6_sprintf(ip6bufs, &taddr6), 303 ifp->if_addrlen, lladdrlen - 2)); 304 goto bad; 305 } 306 307 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) { 308 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n", 309 ip6_sprintf(ip6bufs, &saddr6))); 310 goto freeit; 311 } 312 313 /* 314 * We have neighbor solicitation packet, with target address equals to 315 * one of my tentative address. 316 * 317 * src addr how to process? 318 * --- --- 319 * multicast of course, invalid (rejected in ip6_input) 320 * unicast somebody is doing address resolution -> ignore 321 * unspec dup address detection 322 * 323 * The processing is defined in RFC 2462. 324 */ 325 if (tentative) { 326 /* 327 * If source address is unspecified address, it is for 328 * duplicate address detection. 329 * 330 * If not, the packet is for addess resolution; 331 * silently ignore it. 332 */ 333 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) 334 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce); 335 336 goto freeit; 337 } 338 339 /* 340 * If the source address is unspecified address, entries must not 341 * be created or updated. 342 * It looks that sender is performing DAD. Output NA toward 343 * all-node multicast address, to tell the sender that I'm using 344 * the address. 345 * S bit ("solicited") must be zero. 346 */ 347 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) { 348 struct in6_addr in6_all; 349 350 in6_all = in6addr_linklocal_allnodes; 351 if (in6_setscope(&in6_all, ifp, NULL) != 0) 352 goto bad; 353 nd6_na_output_fib(ifp, &in6_all, &taddr6, 354 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 355 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, 356 M_GETFIB(m)); 357 goto freeit; 358 } 359 360 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, 361 ND_NEIGHBOR_SOLICIT, 0); 362 363 nd6_na_output_fib(ifp, &saddr6, &taddr6, 364 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) | 365 rflag | ND_NA_FLAG_SOLICITED, tlladdr, 366 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m)); 367 freeit: 368 if (ifa != NULL) 369 ifa_free(ifa); 370 m_freem(m); 371 return; 372 373 bad: 374 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", 375 ip6_sprintf(ip6bufs, &saddr6))); 376 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", 377 ip6_sprintf(ip6bufs, &daddr6))); 378 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", 379 ip6_sprintf(ip6bufs, &taddr6))); 380 ICMP6STAT_INC(icp6s_badns); 381 if (ifa != NULL) 382 ifa_free(ifa); 383 m_freem(m); 384} 385 386/* 387 * Output a Neighbor Solicitation Message. Caller specifies: 388 * - ICMP6 header source IP6 address 389 * - ND6 header target IP6 address 390 * - ND6 header source datalink address 391 * 392 * Based on RFC 2461 393 * Based on RFC 2462 (duplicate address detection) 394 * 395 * ln - for source address determination 396 * nonce - If non-NULL, NS is used for duplicate address detection and 397 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce. 398 */ 399static void 400nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6, 401 const struct in6_addr *taddr6, struct llentry *ln, uint8_t *nonce, 402 u_int fibnum) 403{ 404 struct mbuf *m; 405 struct m_tag *mtag; 406 struct ip6_hdr *ip6; 407 struct nd_neighbor_solicit *nd_ns; 408 struct ip6_moptions im6o; 409 int icmp6len; 410 int maxlen; 411 caddr_t mac; 412 struct route_in6 ro; 413 414 if (IN6_IS_ADDR_MULTICAST(taddr6)) 415 return; 416 417 /* estimate the size of message */ 418 maxlen = sizeof(*ip6) + sizeof(*nd_ns); 419 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 420 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 421 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 422 __func__, max_linkhdr, maxlen, MCLBYTES)); 423 424 425 if (max_linkhdr + maxlen > MHLEN) 426 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 427 else 428 m = m_gethdr(M_NOWAIT, MT_DATA); 429 if (m == NULL) 430 return; 431 M_SETFIB(m, fibnum); 432 433 bzero(&ro, sizeof(ro)); 434 435 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) { 436 m->m_flags |= M_MCAST; 437 im6o.im6o_multicast_ifp = ifp; 438 im6o.im6o_multicast_hlim = 255; 439 im6o.im6o_multicast_loop = 0; 440 } 441 442 icmp6len = sizeof(*nd_ns); 443 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len; 444 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 445 446 /* fill neighbor solicitation packet */ 447 ip6 = mtod(m, struct ip6_hdr *); 448 ip6->ip6_flow = 0; 449 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 450 ip6->ip6_vfc |= IPV6_VERSION; 451 /* ip6->ip6_plen will be set later */ 452 ip6->ip6_nxt = IPPROTO_ICMPV6; 453 ip6->ip6_hlim = 255; 454 if (daddr6) 455 ip6->ip6_dst = *daddr6; 456 else { 457 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 458 ip6->ip6_dst.s6_addr16[1] = 0; 459 ip6->ip6_dst.s6_addr32[1] = 0; 460 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE; 461 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3]; 462 ip6->ip6_dst.s6_addr8[12] = 0xff; 463 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) 464 goto bad; 465 } 466 if (nonce == NULL) { 467 struct ifaddr *ifa; 468 469 /* 470 * RFC2461 7.2.2: 471 * "If the source address of the packet prompting the 472 * solicitation is the same as one of the addresses assigned 473 * to the outgoing interface, that address SHOULD be placed 474 * in the IP Source Address of the outgoing solicitation. 475 * Otherwise, any one of the addresses assigned to the 476 * interface should be used." 477 * 478 * We use the source address for the prompting packet 479 * (saddr6), if: 480 * - saddr6 is given from the caller (by giving "ln"), and 481 * - saddr6 belongs to the outgoing interface. 482 * Otherwise, we perform the source address selection as usual. 483 */ 484 struct in6_addr *hsrc; 485 486 hsrc = NULL; 487 if (ln != NULL) { 488 LLE_RLOCK(ln); 489 if (ln->la_hold != NULL) { 490 struct ip6_hdr *hip6; /* hold ip6 */ 491 492 /* 493 * assuming every packet in la_hold has the same IP 494 * header 495 */ 496 hip6 = mtod(ln->la_hold, struct ip6_hdr *); 497 /* XXX pullup? */ 498 if (sizeof(*hip6) < ln->la_hold->m_len) { 499 ip6->ip6_src = hip6->ip6_src; 500 hsrc = &hip6->ip6_src; 501 } 502 } 503 LLE_RUNLOCK(ln); 504 } 505 if (hsrc && (ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, 506 hsrc)) != NULL) { 507 /* ip6_src set already. */ 508 ifa_free(ifa); 509 } else { 510 int error; 511 struct sockaddr_in6 dst_sa; 512 struct in6_addr src_in; 513 struct ifnet *oifp; 514 515 bzero(&dst_sa, sizeof(dst_sa)); 516 dst_sa.sin6_family = AF_INET6; 517 dst_sa.sin6_len = sizeof(dst_sa); 518 dst_sa.sin6_addr = ip6->ip6_dst; 519 520 oifp = ifp; 521 error = in6_selectsrc(&dst_sa, NULL, 522 NULL, &ro, NULL, &oifp, &src_in); 523 if (error) { 524 char ip6buf[INET6_ADDRSTRLEN]; 525 nd6log((LOG_DEBUG, "%s: source can't be " 526 "determined: dst=%s, error=%d\n", __func__, 527 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), 528 error)); 529 goto bad; 530 } 531 ip6->ip6_src = src_in; 532 } 533 } else { 534 /* 535 * Source address for DAD packet must always be IPv6 536 * unspecified address. (0::0) 537 * We actually don't have to 0-clear the address (we did it 538 * above), but we do so here explicitly to make the intention 539 * clearer. 540 */ 541 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src)); 542 } 543 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1); 544 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT; 545 nd_ns->nd_ns_code = 0; 546 nd_ns->nd_ns_reserved = 0; 547 nd_ns->nd_ns_target = *taddr6; 548 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */ 549 550 /* 551 * Add source link-layer address option. 552 * 553 * spec implementation 554 * --- --- 555 * DAD packet MUST NOT do not add the option 556 * there's no link layer address: 557 * impossible do not add the option 558 * there's link layer address: 559 * Multicast NS MUST add one add the option 560 * Unicast NS SHOULD add one add the option 561 */ 562 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) { 563 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 564 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 565 /* 8 byte alignments... */ 566 optlen = (optlen + 7) & ~7; 567 568 m->m_pkthdr.len += optlen; 569 m->m_len += optlen; 570 icmp6len += optlen; 571 bzero((caddr_t)nd_opt, optlen); 572 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; 573 nd_opt->nd_opt_len = optlen >> 3; 574 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 575 } 576 /* 577 * Add a Nonce option (RFC 3971) to detect looped back NS messages. 578 * This behavior is documented as Enhanced Duplicate Address 579 * Detection in RFC 7527. 580 * net.inet6.ip6.dad_enhanced=0 disables this. 581 */ 582 if (V_dad_enhanced != 0 && nonce != NULL) { 583 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN; 584 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1); 585 /* 8-byte alignment is required. */ 586 optlen = (optlen + 7) & ~7; 587 588 m->m_pkthdr.len += optlen; 589 m->m_len += optlen; 590 icmp6len += optlen; 591 bzero((caddr_t)nd_opt, optlen); 592 nd_opt->nd_opt_type = ND_OPT_NONCE; 593 nd_opt->nd_opt_len = optlen >> 3; 594 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN); 595 } 596 ip6->ip6_plen = htons((u_short)icmp6len); 597 nd_ns->nd_ns_cksum = 0; 598 nd_ns->nd_ns_cksum = 599 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len); 600 601 if (send_sendso_input_hook != NULL) { 602 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 603 sizeof(unsigned short), M_NOWAIT); 604 if (mtag == NULL) 605 goto bad; 606 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type; 607 m_tag_prepend(m, mtag); 608 } 609 610 ip6_output(m, NULL, &ro, (nonce != NULL) ? IPV6_UNSPECSRC : 0, 611 &im6o, NULL, NULL); 612 icmp6_ifstat_inc(ifp, ifs6_out_msg); 613 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); 614 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]); 615 616 /* We don't cache this route. */ 617 RO_RTFREE(&ro); 618 619 return; 620 621 bad: 622 if (ro.ro_rt) { 623 RTFREE(ro.ro_rt); 624 } 625 m_freem(m); 626} 627 628#ifndef BURN_BRIDGES 629void 630nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6, 631 const struct in6_addr *taddr6, struct llentry *ln, uint8_t *nonce) 632{ 633 634 nd6_ns_output_fib(ifp, daddr6, taddr6, ln, nonce, RT_DEFAULT_FIB); 635} 636#endif 637/* 638 * Neighbor advertisement input handling. 639 * 640 * Based on RFC 2461 641 * Based on RFC 2462 (duplicate address detection) 642 * 643 * the following items are not implemented yet: 644 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 645 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 646 */ 647void 648nd6_na_input(struct mbuf *m, int off, int icmp6len) 649{ 650 struct ifnet *ifp = m->m_pkthdr.rcvif; 651 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 652 struct nd_neighbor_advert *nd_na; 653 struct in6_addr daddr6 = ip6->ip6_dst; 654 struct in6_addr taddr6; 655 int flags; 656 int is_router; 657 int is_solicited; 658 int is_override; 659 char *lladdr = NULL; 660 int lladdrlen = 0; 661 int checklink = 0; 662 struct ifaddr *ifa; 663 struct llentry *ln = NULL; 664 union nd_opts ndopts; 665 struct mbuf *chain = NULL; 666 struct sockaddr_in6 sin6; 667 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; 668 669 if (ip6->ip6_hlim != 255) { 670 nd6log((LOG_ERR, 671 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n", 672 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src), 673 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp))); 674 goto bad; 675 } 676 677#ifndef PULLDOWN_TEST 678 IP6_EXTHDR_CHECK(m, off, icmp6len,); 679 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off); 680#else 681 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len); 682 if (nd_na == NULL) { 683 ICMP6STAT_INC(icp6s_tooshort); 684 return; 685 } 686#endif 687 688 flags = nd_na->nd_na_flags_reserved; 689 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0); 690 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0); 691 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0); 692 memset(&sin6, 0, sizeof(sin6)); 693 694 taddr6 = nd_na->nd_na_target; 695 if (in6_setscope(&taddr6, ifp, NULL)) 696 goto bad; /* XXX: impossible */ 697 698 if (IN6_IS_ADDR_MULTICAST(&taddr6)) { 699 nd6log((LOG_ERR, 700 "nd6_na_input: invalid target address %s\n", 701 ip6_sprintf(ip6bufs, &taddr6))); 702 goto bad; 703 } 704 if (IN6_IS_ADDR_MULTICAST(&daddr6)) 705 if (is_solicited) { 706 nd6log((LOG_ERR, 707 "nd6_na_input: a solicited adv is multicasted\n")); 708 goto bad; 709 } 710 711 icmp6len -= sizeof(*nd_na); 712 nd6_option_init(nd_na + 1, icmp6len, &ndopts); 713 if (nd6_options(&ndopts) < 0) { 714 nd6log((LOG_INFO, 715 "nd6_na_input: invalid ND option, ignored\n")); 716 /* nd6_options have incremented stats */ 717 goto freeit; 718 } 719 720 if (ndopts.nd_opts_tgt_lladdr) { 721 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1); 722 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3; 723 } 724 725 /* 726 * This effectively disables the DAD check on a non-master CARP 727 * address. 728 */ 729 if (ifp->if_carp) 730 ifa = (*carp_iamatch6_p)(ifp, &taddr6); 731 else 732 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6); 733 734 /* 735 * Target address matches one of my interface address. 736 * 737 * If my address is tentative, this means that there's somebody 738 * already using the same address as mine. This indicates DAD failure. 739 * This is defined in RFC 2462. 740 * 741 * Otherwise, process as defined in RFC 2461. 742 */ 743 if (ifa 744 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) { 745 nd6_dad_na_input(ifa); 746 ifa_free(ifa); 747 goto freeit; 748 } 749 750 /* Just for safety, maybe unnecessary. */ 751 if (ifa) { 752 ifa_free(ifa); 753 log(LOG_ERR, 754 "nd6_na_input: duplicate IP6 address %s\n", 755 ip6_sprintf(ip6bufs, &taddr6)); 756 goto freeit; 757 } 758 759 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) { 760 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s " 761 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6), 762 ifp->if_addrlen, lladdrlen - 2)); 763 goto bad; 764 } 765 766 /* 767 * If no neighbor cache entry is found, NA SHOULD silently be 768 * discarded. 769 */ 770 IF_AFDATA_RLOCK(ifp); 771 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp); 772 IF_AFDATA_RUNLOCK(ifp); 773 if (ln == NULL) { 774 goto freeit; 775 } 776 777 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) { 778 /* 779 * If the link-layer has address, and no lladdr option came, 780 * discard the packet. 781 */ 782 if (ifp->if_addrlen && lladdr == NULL) { 783 goto freeit; 784 } 785 786 /* 787 * Record link-layer address, and update the state. 788 */ 789 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen); 790 ln->la_flags |= LLE_VALID; 791 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); 792 if (is_solicited) { 793 ln->ln_state = ND6_LLINFO_REACHABLE; 794 ln->ln_byhint = 0; 795 if (!ND6_LLINFO_PERMANENT(ln)) { 796 nd6_llinfo_settimer_locked(ln, 797 (long)ND_IFINFO(ln->lle_tbl->llt_ifp)->reachable * hz); 798 } 799 } else { 800 ln->ln_state = ND6_LLINFO_STALE; 801 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz); 802 } 803 if ((ln->ln_router = is_router) != 0) { 804 /* 805 * This means a router's state has changed from 806 * non-reachable to probably reachable, and might 807 * affect the status of associated prefixes.. 808 */ 809 checklink = 1; 810 } 811 } else { 812 int llchange; 813 814 /* 815 * Check if the link-layer address has changed or not. 816 */ 817 if (lladdr == NULL) 818 llchange = 0; 819 else { 820 if (ln->la_flags & LLE_VALID) { 821 if (bcmp(lladdr, &ln->ll_addr, ifp->if_addrlen)) 822 llchange = 1; 823 else 824 llchange = 0; 825 } else 826 llchange = 1; 827 } 828 829 /* 830 * This is VERY complex. Look at it with care. 831 * 832 * override solicit lladdr llchange action 833 * (L: record lladdr) 834 * 835 * 0 0 n -- (2c) 836 * 0 0 y n (2b) L 837 * 0 0 y y (1) REACHABLE->STALE 838 * 0 1 n -- (2c) *->REACHABLE 839 * 0 1 y n (2b) L *->REACHABLE 840 * 0 1 y y (1) REACHABLE->STALE 841 * 1 0 n -- (2a) 842 * 1 0 y n (2a) L 843 * 1 0 y y (2a) L *->STALE 844 * 1 1 n -- (2a) *->REACHABLE 845 * 1 1 y n (2a) L *->REACHABLE 846 * 1 1 y y (2a) L *->REACHABLE 847 */ 848 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */ 849 /* 850 * If state is REACHABLE, make it STALE. 851 * no other updates should be done. 852 */ 853 if (ln->ln_state == ND6_LLINFO_REACHABLE) { 854 ln->ln_state = ND6_LLINFO_STALE; 855 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz); 856 } 857 goto freeit; 858 } else if (is_override /* (2a) */ 859 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */ 860 || lladdr == NULL) { /* (2c) */ 861 /* 862 * Update link-local address, if any. 863 */ 864 if (lladdr != NULL) { 865 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen); 866 ln->la_flags |= LLE_VALID; 867 EVENTHANDLER_INVOKE(lle_event, ln, 868 LLENTRY_RESOLVED); 869 } 870 871 /* 872 * If solicited, make the state REACHABLE. 873 * If not solicited and the link-layer address was 874 * changed, make it STALE. 875 */ 876 if (is_solicited) { 877 ln->ln_state = ND6_LLINFO_REACHABLE; 878 ln->ln_byhint = 0; 879 if (!ND6_LLINFO_PERMANENT(ln)) { 880 nd6_llinfo_settimer_locked(ln, 881 (long)ND_IFINFO(ifp)->reachable * hz); 882 } 883 } else { 884 if (lladdr != NULL && llchange) { 885 ln->ln_state = ND6_LLINFO_STALE; 886 nd6_llinfo_settimer_locked(ln, 887 (long)V_nd6_gctimer * hz); 888 } 889 } 890 } 891 892 if (ln->ln_router && !is_router) { 893 /* 894 * The peer dropped the router flag. 895 * Remove the sender from the Default Router List and 896 * update the Destination Cache entries. 897 */ 898 struct nd_defrouter *dr; 899 struct in6_addr *in6; 900 901 in6 = &L3_ADDR_SIN6(ln)->sin6_addr; 902 903 dr = defrouter_lookup(in6, ln->lle_tbl->llt_ifp); 904 if (dr) 905 defrtrlist_del(dr); 906 else if (ND_IFINFO(ln->lle_tbl->llt_ifp)->flags & 907 ND6_IFF_ACCEPT_RTADV) { 908 /* 909 * Even if the neighbor is not in the default 910 * router list, the neighbor may be used 911 * as a next hop for some destinations 912 * (e.g. redirect case). So we must 913 * call rt6_flush explicitly. 914 */ 915 rt6_flush(&ip6->ip6_src, ifp); 916 } 917 } 918 ln->ln_router = is_router; 919 } 920 /* XXX - QL 921 * Does this matter? 922 * rt->rt_flags &= ~RTF_REJECT; 923 */ 924 ln->la_asked = 0; 925 if (ln->la_hold != NULL) 926 nd6_grab_holdchain(ln, &chain, &sin6); 927 freeit: 928 if (ln != NULL) 929 LLE_WUNLOCK(ln); 930 931 if (chain != NULL) 932 nd6_flush_holdchain(ifp, ifp, chain, &sin6); 933 934 if (checklink) 935 pfxlist_onlink_check(); 936 937 m_freem(m); 938 return; 939 940 bad: 941 if (ln != NULL) 942 LLE_WUNLOCK(ln); 943 944 ICMP6STAT_INC(icp6s_badna); 945 m_freem(m); 946} 947 948/* 949 * Neighbor advertisement output handling. 950 * 951 * Based on RFC 2461 952 * 953 * the following items are not implemented yet: 954 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD) 955 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD) 956 * 957 * tlladdr - 1 if include target link-layer address 958 * sdl0 - sockaddr_dl (= proxy NA) or NULL 959 */ 960static void 961nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0, 962 const struct in6_addr *taddr6, u_long flags, int tlladdr, 963 struct sockaddr *sdl0, u_int fibnum) 964{ 965 struct mbuf *m; 966 struct m_tag *mtag; 967 struct ifnet *oifp; 968 struct ip6_hdr *ip6; 969 struct nd_neighbor_advert *nd_na; 970 struct ip6_moptions im6o; 971 struct in6_addr src, daddr6; 972 struct sockaddr_in6 dst_sa; 973 int icmp6len, maxlen, error; 974 caddr_t mac = NULL; 975 struct route_in6 ro; 976 977 bzero(&ro, sizeof(ro)); 978 979 daddr6 = *daddr6_0; /* make a local copy for modification */ 980 981 /* estimate the size of message */ 982 maxlen = sizeof(*ip6) + sizeof(*nd_na); 983 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7; 984 KASSERT(max_linkhdr + maxlen <= MCLBYTES, ( 985 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)", 986 __func__, max_linkhdr, maxlen, MCLBYTES)); 987 988 if (max_linkhdr + maxlen > MHLEN) 989 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); 990 else 991 m = m_gethdr(M_NOWAIT, MT_DATA); 992 if (m == NULL) 993 return; 994 M_SETFIB(m, fibnum); 995 996 if (IN6_IS_ADDR_MULTICAST(&daddr6)) { 997 m->m_flags |= M_MCAST; 998 im6o.im6o_multicast_ifp = ifp; 999 im6o.im6o_multicast_hlim = 255; 1000 im6o.im6o_multicast_loop = 0; 1001 } 1002 1003 icmp6len = sizeof(*nd_na); 1004 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len; 1005 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */ 1006 1007 /* fill neighbor advertisement packet */ 1008 ip6 = mtod(m, struct ip6_hdr *); 1009 ip6->ip6_flow = 0; 1010 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 1011 ip6->ip6_vfc |= IPV6_VERSION; 1012 ip6->ip6_nxt = IPPROTO_ICMPV6; 1013 ip6->ip6_hlim = 255; 1014 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) { 1015 /* reply to DAD */ 1016 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL; 1017 daddr6.s6_addr16[1] = 0; 1018 daddr6.s6_addr32[1] = 0; 1019 daddr6.s6_addr32[2] = 0; 1020 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE; 1021 if (in6_setscope(&daddr6, ifp, NULL)) 1022 goto bad; 1023 1024 flags &= ~ND_NA_FLAG_SOLICITED; 1025 } 1026 ip6->ip6_dst = daddr6; 1027 bzero(&dst_sa, sizeof(struct sockaddr_in6)); 1028 dst_sa.sin6_family = AF_INET6; 1029 dst_sa.sin6_len = sizeof(struct sockaddr_in6); 1030 dst_sa.sin6_addr = daddr6; 1031 1032 /* 1033 * Select a source whose scope is the same as that of the dest. 1034 */ 1035 bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa)); 1036 oifp = ifp; 1037 error = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, &oifp, &src); 1038 if (error) { 1039 char ip6buf[INET6_ADDRSTRLEN]; 1040 nd6log((LOG_DEBUG, "nd6_na_output: source can't be " 1041 "determined: dst=%s, error=%d\n", 1042 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), error)); 1043 goto bad; 1044 } 1045 ip6->ip6_src = src; 1046 nd_na = (struct nd_neighbor_advert *)(ip6 + 1); 1047 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT; 1048 nd_na->nd_na_code = 0; 1049 nd_na->nd_na_target = *taddr6; 1050 in6_clearscope(&nd_na->nd_na_target); /* XXX */ 1051 1052 /* 1053 * "tlladdr" indicates NS's condition for adding tlladdr or not. 1054 * see nd6_ns_input() for details. 1055 * Basically, if NS packet is sent to unicast/anycast addr, 1056 * target lladdr option SHOULD NOT be included. 1057 */ 1058 if (tlladdr) { 1059 /* 1060 * sdl0 != NULL indicates proxy NA. If we do proxy, use 1061 * lladdr in sdl0. If we are not proxying (sending NA for 1062 * my address) use lladdr configured for the interface. 1063 */ 1064 if (sdl0 == NULL) { 1065 if (ifp->if_carp) 1066 mac = (*carp_macmatch6_p)(ifp, m, taddr6); 1067 if (mac == NULL) 1068 mac = nd6_ifptomac(ifp); 1069 } else if (sdl0->sa_family == AF_LINK) { 1070 struct sockaddr_dl *sdl; 1071 sdl = (struct sockaddr_dl *)sdl0; 1072 if (sdl->sdl_alen == ifp->if_addrlen) 1073 mac = LLADDR(sdl); 1074 } 1075 } 1076 if (tlladdr && mac) { 1077 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen; 1078 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1); 1079 1080 /* roundup to 8 bytes alignment! */ 1081 optlen = (optlen + 7) & ~7; 1082 1083 m->m_pkthdr.len += optlen; 1084 m->m_len += optlen; 1085 icmp6len += optlen; 1086 bzero((caddr_t)nd_opt, optlen); 1087 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; 1088 nd_opt->nd_opt_len = optlen >> 3; 1089 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen); 1090 } else 1091 flags &= ~ND_NA_FLAG_OVERRIDE; 1092 1093 ip6->ip6_plen = htons((u_short)icmp6len); 1094 nd_na->nd_na_flags_reserved = flags; 1095 nd_na->nd_na_cksum = 0; 1096 nd_na->nd_na_cksum = 1097 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len); 1098 1099 if (send_sendso_input_hook != NULL) { 1100 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, 1101 sizeof(unsigned short), M_NOWAIT); 1102 if (mtag == NULL) 1103 goto bad; 1104 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type; 1105 m_tag_prepend(m, mtag); 1106 } 1107 1108 ip6_output(m, NULL, &ro, 0, &im6o, NULL, NULL); 1109 icmp6_ifstat_inc(ifp, ifs6_out_msg); 1110 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); 1111 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]); 1112 1113 /* We don't cache this route. */ 1114 RO_RTFREE(&ro); 1115 1116 return; 1117 1118 bad: 1119 if (ro.ro_rt) { 1120 RTFREE(ro.ro_rt); 1121 } 1122 m_freem(m); 1123} 1124 1125#ifndef BURN_BRIDGES 1126void 1127nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0, 1128 const struct in6_addr *taddr6, u_long flags, int tlladdr, 1129 struct sockaddr *sdl0) 1130{ 1131 1132 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0, 1133 RT_DEFAULT_FIB); 1134} 1135#endif 1136 1137caddr_t 1138nd6_ifptomac(struct ifnet *ifp) 1139{ 1140 switch (ifp->if_type) { 1141 case IFT_ARCNET: 1142 case IFT_ETHER: 1143 case IFT_FDDI: 1144 case IFT_IEEE1394: 1145#ifdef IFT_L2VLAN 1146 case IFT_L2VLAN: 1147#endif 1148#ifdef IFT_IEEE80211 1149 case IFT_IEEE80211: 1150#endif 1151 case IFT_INFINIBAND: 1152 case IFT_BRIDGE: 1153 case IFT_ISO88025: 1154 return IF_LLADDR(ifp); 1155 default: 1156 return NULL; 1157 } 1158} 1159 1160struct dadq { 1161 TAILQ_ENTRY(dadq) dad_list; 1162 struct ifaddr *dad_ifa; 1163 int dad_count; /* max NS to send */ 1164 int dad_ns_tcount; /* # of trials to send NS */ 1165 int dad_ns_ocount; /* NS sent so far */ 1166 int dad_ns_icount; 1167 int dad_na_icount; 1168 int dad_ns_lcount; /* looped back NS */ 1169 int dad_loopbackprobe; /* probing state for loopback detection */ 1170 struct callout dad_timer_ch; 1171 struct vnet *dad_vnet; 1172 u_int dad_refcnt; 1173#define ND_OPT_NONCE_LEN32 \ 1174 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t)) 1175 uint32_t dad_nonce[ND_OPT_NONCE_LEN32]; 1176}; 1177 1178static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq); 1179static VNET_DEFINE(struct rwlock, dad_rwlock); 1180#define V_dadq VNET(dadq) 1181#define V_dad_rwlock VNET(dad_rwlock) 1182 1183#define DADQ_RLOCK() rw_rlock(&V_dad_rwlock) 1184#define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock) 1185#define DADQ_WLOCK() rw_wlock(&V_dad_rwlock) 1186#define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock) 1187 1188static void 1189nd6_dad_add(struct dadq *dp) 1190{ 1191 1192 DADQ_WLOCK(); 1193 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list); 1194 DADQ_WUNLOCK(); 1195} 1196 1197static void 1198nd6_dad_del(struct dadq *dp) 1199{ 1200 1201 DADQ_WLOCK(); 1202 TAILQ_REMOVE(&V_dadq, dp, dad_list); 1203 DADQ_WUNLOCK(); 1204 nd6_dad_rele(dp); 1205} 1206 1207static struct dadq * 1208nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n) 1209{ 1210 struct dadq *dp; 1211 1212 DADQ_RLOCK(); 1213 TAILQ_FOREACH(dp, &V_dadq, dad_list) { 1214 if (dp->dad_ifa != ifa) 1215 continue; 1216 /* 1217 * Skip if the nonce matches the received one. 1218 * +2 in the length is required because of type and 1219 * length fields are included in a header. 1220 */ 1221 if (n != NULL && 1222 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 && 1223 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0], 1224 ND_OPT_NONCE_LEN) == 0) { 1225 dp->dad_ns_lcount++; 1226 continue; 1227 } 1228 refcount_acquire(&dp->dad_refcnt); 1229 break; 1230 } 1231 DADQ_RUNLOCK(); 1232 1233 return (dp); 1234} 1235 1236static void 1237nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns) 1238{ 1239 1240 if (send_ns != 0) 1241 nd6_dad_ns_output(dp); 1242 callout_reset(&dp->dad_timer_ch, ticks, 1243 (void (*)(void *))nd6_dad_timer, (void *)dp); 1244} 1245 1246static void 1247nd6_dad_stoptimer(struct dadq *dp) 1248{ 1249 1250 callout_drain(&dp->dad_timer_ch); 1251} 1252 1253static void 1254nd6_dad_rele(struct dadq *dp) 1255{ 1256 1257 if (refcount_release(&dp->dad_refcnt)) { 1258 ifa_free(dp->dad_ifa); 1259 free(dp, M_IP6NDP); 1260 } 1261} 1262 1263void 1264nd6_dad_init(void) 1265{ 1266 1267 rw_init(&V_dad_rwlock, "nd6 DAD queue"); 1268 TAILQ_INIT(&V_dadq); 1269} 1270 1271/* 1272 * Start Duplicate Address Detection (DAD) for specified interface address. 1273 */ 1274void 1275nd6_dad_start(struct ifaddr *ifa, int delay) 1276{ 1277 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1278 struct dadq *dp; 1279 char ip6buf[INET6_ADDRSTRLEN]; 1280 int send_ns; 1281 1282 /* 1283 * If we don't need DAD, don't do it. 1284 * There are several cases: 1285 * - DAD is disabled (ip6_dad_count == 0) 1286 * - the interface address is anycast 1287 */ 1288 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) { 1289 log(LOG_DEBUG, 1290 "nd6_dad_start: called with non-tentative address " 1291 "%s(%s)\n", 1292 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1293 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1294 return; 1295 } 1296 if (ia->ia6_flags & IN6_IFF_ANYCAST) { 1297 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1298 return; 1299 } 1300 if (!V_ip6_dad_count) { 1301 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1302 return; 1303 } 1304 if (ifa->ifa_ifp == NULL) 1305 panic("nd6_dad_start: ifa->ifa_ifp == NULL"); 1306 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) { 1307 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1308 return; 1309 } 1310 if (!(ifa->ifa_ifp->if_flags & IFF_UP) || 1311 !(ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) || 1312 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED)) { 1313 ia->ia6_flags |= IN6_IFF_TENTATIVE; 1314 return; 1315 } 1316 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) { 1317 /* 1318 * DAD already in progress. Let the existing entry 1319 * to finish it. 1320 */ 1321 return; 1322 } 1323 1324 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO); 1325 if (dp == NULL) { 1326 log(LOG_ERR, "nd6_dad_start: memory allocation failed for " 1327 "%s(%s)\n", 1328 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1329 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1330 return; 1331 } 1332 callout_init(&dp->dad_timer_ch, 0); 1333#ifdef VIMAGE 1334 dp->dad_vnet = curvnet; 1335#endif 1336 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp), 1337 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1338 1339 /* 1340 * Send NS packet for DAD, ip6_dad_count times. 1341 * Note that we must delay the first transmission, if this is the 1342 * first packet to be sent from the interface after interface 1343 * (re)initialization. 1344 */ 1345 dp->dad_ifa = ifa; 1346 ifa_ref(dp->dad_ifa); 1347 dp->dad_count = V_ip6_dad_count; 1348 dp->dad_ns_icount = dp->dad_na_icount = 0; 1349 dp->dad_ns_ocount = dp->dad_ns_tcount = 0; 1350 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0; 1351 refcount_init(&dp->dad_refcnt, 1); 1352 nd6_dad_add(dp); 1353 send_ns = 0; 1354 if (delay == 0) { 1355 send_ns = 1; 1356 delay = (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000; 1357 } 1358 nd6_dad_starttimer(dp, delay, send_ns); 1359} 1360 1361/* 1362 * terminate DAD unconditionally. used for address removals. 1363 */ 1364void 1365nd6_dad_stop(struct ifaddr *ifa) 1366{ 1367 struct dadq *dp; 1368 1369 dp = nd6_dad_find(ifa, NULL); 1370 if (!dp) { 1371 /* DAD wasn't started yet */ 1372 return; 1373 } 1374 1375 nd6_dad_stoptimer(dp); 1376 1377 /* 1378 * The DAD queue entry may have been removed by nd6_dad_timer() while 1379 * we were waiting for it to stop, so re-do the lookup. 1380 */ 1381 nd6_dad_rele(dp); 1382 if (nd6_dad_find(ifa, NULL) == NULL) 1383 return; 1384 1385 nd6_dad_del(dp); 1386 nd6_dad_rele(dp); 1387} 1388 1389static void 1390nd6_dad_timer(struct dadq *dp) 1391{ 1392 CURVNET_SET(dp->dad_vnet); 1393 struct ifaddr *ifa = dp->dad_ifa; 1394 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1395 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1396 char ip6buf[INET6_ADDRSTRLEN]; 1397 1398 /* Sanity check */ 1399 if (ia == NULL) { 1400 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n"); 1401 goto err; 1402 } 1403 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) { 1404 /* Do not need DAD for ifdisabled interface. */ 1405 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of " 1406 "ND6_IFF_IFDISABLED.\n", ifp->if_xname); 1407 goto err; 1408 } 1409 if (ia->ia6_flags & IN6_IFF_DUPLICATED) { 1410 log(LOG_ERR, "nd6_dad_timer: called with duplicated address " 1411 "%s(%s)\n", 1412 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1413 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1414 goto err; 1415 } 1416 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) { 1417 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address " 1418 "%s(%s)\n", 1419 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1420 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???"); 1421 goto err; 1422 } 1423 1424 /* Stop DAD if the interface is down even after dad_maxtry attempts. */ 1425 if ((dp->dad_ns_tcount > V_dad_maxtry) && 1426 (((ifp->if_flags & IFF_UP) == 0) || 1427 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) { 1428 nd6log((LOG_INFO, "%s: could not run DAD " 1429 "because the interface was down or not running.\n", 1430 if_name(ifa->ifa_ifp))); 1431 goto err; 1432 } 1433 1434 /* Need more checks? */ 1435 if (dp->dad_ns_ocount < dp->dad_count) { 1436 /* 1437 * We have more NS to go. Send NS packet for DAD. 1438 */ 1439 nd6_dad_starttimer(dp, 1440 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1); 1441 goto done; 1442 } else { 1443 /* 1444 * We have transmitted sufficient number of DAD packets. 1445 * See what we've got. 1446 */ 1447 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) 1448 /* We've seen NS or NA, means DAD has failed. */ 1449 nd6_dad_duplicated(ifa, dp); 1450 else if (V_dad_enhanced != 0 && 1451 dp->dad_ns_lcount > 0 && 1452 dp->dad_ns_lcount > dp->dad_loopbackprobe) { 1453 /* 1454 * Sec. 4.1 in RFC 7527 requires transmission of 1455 * additional probes until the loopback condition 1456 * becomes clear when a looped back probe is detected. 1457 */ 1458 log(LOG_ERR, "%s: a looped back NS message is " 1459 "detected during DAD for %s. " 1460 "Another DAD probes are being sent.\n", 1461 if_name(ifa->ifa_ifp), 1462 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1463 dp->dad_loopbackprobe = dp->dad_ns_lcount; 1464 /* 1465 * Send an NS immediately and increase dad_count by 1466 * V_nd6_mmaxtries - 1. 1467 */ 1468 dp->dad_count = 1469 dp->dad_ns_ocount + V_nd6_mmaxtries - 1; 1470 nd6_dad_starttimer(dp, 1471 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1472 1); 1473 goto done; 1474 } else { 1475 /* 1476 * We are done with DAD. No NA came, no NS came. 1477 * No duplicate address found. Check IFDISABLED flag 1478 * again in case that it is changed between the 1479 * beginning of this function and here. 1480 */ 1481 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0) 1482 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1483 1484 nd6log((LOG_DEBUG, 1485 "%s: DAD complete for %s - no duplicates found\n", 1486 if_name(ifa->ifa_ifp), 1487 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr))); 1488 if (dp->dad_ns_lcount > 0) 1489 log(LOG_ERR, "%s: DAD completed while " 1490 "a looped back NS message is detected " 1491 "during DAD for %s.\n", 1492 if_name(ifa->ifa_ifp), 1493 ip6_sprintf(ip6buf, IFA_IN6(ifa))); 1494 } 1495 } 1496err: 1497 nd6_dad_del(dp); 1498done: 1499 CURVNET_RESTORE(); 1500} 1501 1502static void 1503nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp) 1504{ 1505 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa; 1506 struct ifnet *ifp; 1507 char ip6buf[INET6_ADDRSTRLEN]; 1508 1509 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: " 1510 "NS in/out/loopback=%d/%d/%d, NA in=%d\n", 1511 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr), 1512 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount, 1513 dp->dad_na_icount); 1514 1515 ia->ia6_flags &= ~IN6_IFF_TENTATIVE; 1516 ia->ia6_flags |= IN6_IFF_DUPLICATED; 1517 1518 ifp = ifa->ifa_ifp; 1519 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n", 1520 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)); 1521 log(LOG_ERR, "%s: manual intervention required\n", 1522 if_name(ifp)); 1523 1524 /* 1525 * If the address is a link-local address formed from an interface 1526 * identifier based on the hardware address which is supposed to be 1527 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP 1528 * operation on the interface SHOULD be disabled. 1529 * [RFC 4862, Section 5.4.5] 1530 */ 1531 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) { 1532 struct in6_addr in6; 1533 1534 /* 1535 * To avoid over-reaction, we only apply this logic when we are 1536 * very sure that hardware addresses are supposed to be unique. 1537 */ 1538 switch (ifp->if_type) { 1539 case IFT_ETHER: 1540 case IFT_FDDI: 1541 case IFT_ATM: 1542 case IFT_IEEE1394: 1543#ifdef IFT_IEEE80211 1544 case IFT_IEEE80211: 1545#endif 1546 case IFT_INFINIBAND: 1547 in6 = ia->ia_addr.sin6_addr; 1548 if (in6_get_hw_ifid(ifp, &in6) == 0 && 1549 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) { 1550 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; 1551 log(LOG_ERR, "%s: possible hardware address " 1552 "duplication detected, disable IPv6\n", 1553 if_name(ifp)); 1554 } 1555 break; 1556 } 1557 } 1558} 1559 1560static void 1561nd6_dad_ns_output(struct dadq *dp) 1562{ 1563 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa; 1564 struct ifnet *ifp = dp->dad_ifa->ifa_ifp; 1565 int i; 1566 1567 dp->dad_ns_tcount++; 1568 if ((ifp->if_flags & IFF_UP) == 0) { 1569 return; 1570 } 1571 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) { 1572 return; 1573 } 1574 1575 dp->dad_ns_ocount++; 1576 if (V_dad_enhanced != 0) { 1577 for (i = 0; i < ND_OPT_NONCE_LEN32; i++) 1578 dp->dad_nonce[i] = arc4random(); 1579 /* 1580 * XXXHRS: Note that in the case that 1581 * DupAddrDetectTransmits > 1, multiple NS messages with 1582 * different nonces can be looped back in an unexpected 1583 * order. The current implementation recognizes only 1584 * the latest nonce on the sender side. Practically it 1585 * should work well in almost all cases. 1586 */ 1587 } 1588 nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1589 (uint8_t *)&dp->dad_nonce[0]); 1590} 1591 1592static void 1593nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce) 1594{ 1595 struct in6_ifaddr *ia; 1596 struct ifnet *ifp; 1597 const struct in6_addr *taddr6; 1598 struct dadq *dp; 1599 1600 if (ifa == NULL) 1601 panic("ifa == NULL in nd6_dad_ns_input"); 1602 1603 ia = (struct in6_ifaddr *)ifa; 1604 ifp = ifa->ifa_ifp; 1605 taddr6 = &ia->ia_addr.sin6_addr; 1606 /* Ignore Nonce option when Enhanced DAD is disabled. */ 1607 if (V_dad_enhanced == 0) 1608 ndopt_nonce = NULL; 1609 dp = nd6_dad_find(ifa, ndopt_nonce); 1610 if (dp == NULL) 1611 return; 1612 1613 dp->dad_ns_icount++; 1614 nd6_dad_rele(dp); 1615} 1616 1617static void 1618nd6_dad_na_input(struct ifaddr *ifa) 1619{ 1620 struct dadq *dp; 1621 1622 if (ifa == NULL) 1623 panic("ifa == NULL in nd6_dad_na_input"); 1624 1625 dp = nd6_dad_find(ifa, NULL); 1626 if (dp != NULL) { 1627 dp->dad_na_icount++; 1628 nd6_dad_rele(dp); 1629 } 1630} 1631