1 /* 2 * Neighbour Discovery for IPv6 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * Mike Shaver <shaver@ingenia.com> 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License 11 * as published by the Free Software Foundation; either version 12 * 2 of the License, or (at your option) any later version. 13 */ 14 15 /* 16 * Changes: 17 * 18 * Alexey I. Froloff : RFC6106 (DNSSL) support 19 * Pierre Ynard : export userland ND options 20 * through netlink (RDNSS support) 21 * Lars Fenneberg : fixed MTU setting on receipt 22 * of an RA. 23 * Janos Farkas : kmalloc failure checks 24 * Alexey Kuznetsov : state machine reworked 25 * and moved to net/core. 26 * Pekka Savola : RFC2461 validation 27 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly 28 */ 29 30 #define pr_fmt(fmt) "ICMPv6: " fmt 31 32 #include <linux/module.h> 33 #include <linux/errno.h> 34 #include <linux/types.h> 35 #include <linux/socket.h> 36 #include <linux/sockios.h> 37 #include <linux/sched.h> 38 #include <linux/net.h> 39 #include <linux/in6.h> 40 #include <linux/route.h> 41 #include <linux/init.h> 42 #include <linux/rcupdate.h> 43 #include <linux/slab.h> 44 #ifdef CONFIG_SYSCTL 45 #include <linux/sysctl.h> 46 #endif 47 48 #include <linux/if_addr.h> 49 #include <linux/if_arp.h> 50 #include <linux/ipv6.h> 51 #include <linux/icmpv6.h> 52 #include <linux/jhash.h> 53 54 #include <net/sock.h> 55 #include <net/snmp.h> 56 57 #include <net/ipv6.h> 58 #include <net/protocol.h> 59 #include <net/ndisc.h> 60 #include <net/ip6_route.h> 61 #include <net/addrconf.h> 62 #include <net/icmp.h> 63 64 #include <net/netlink.h> 65 #include <linux/rtnetlink.h> 66 67 #include <net/flow.h> 68 #include <net/ip6_checksum.h> 69 #include <net/inet_common.h> 70 #include <linux/proc_fs.h> 71 72 #include <linux/netfilter.h> 73 #include <linux/netfilter_ipv6.h> 74 75 /* Set to 3 to get tracing... */ 76 #define ND_DEBUG 1 77 78 #define ND_PRINTK(val, level, fmt, ...) \ 79 do { \ 80 if (val <= ND_DEBUG) \ 81 net_##level##_ratelimited(fmt, ##__VA_ARGS__); \ 82 } while (0) 83 84 static u32 ndisc_hash(const void *pkey, 85 const struct net_device *dev, 86 __u32 *hash_rnd); 87 static int ndisc_constructor(struct neighbour *neigh); 88 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb); 89 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb); 90 static int pndisc_constructor(struct pneigh_entry *n); 91 static void pndisc_destructor(struct pneigh_entry *n); 92 static void pndisc_redo(struct sk_buff *skb); 93 94 static const struct neigh_ops ndisc_generic_ops = { 95 .family = AF_INET6, 96 .solicit = ndisc_solicit, 97 .error_report = ndisc_error_report, 98 .output = neigh_resolve_output, 99 .connected_output = neigh_connected_output, 100 }; 101 102 static const struct neigh_ops ndisc_hh_ops = { 103 .family = AF_INET6, 104 .solicit = ndisc_solicit, 105 .error_report = ndisc_error_report, 106 .output = neigh_resolve_output, 107 .connected_output = neigh_resolve_output, 108 }; 109 110 111 static const struct neigh_ops ndisc_direct_ops = { 112 .family = AF_INET6, 113 .output = neigh_direct_output, 114 .connected_output = neigh_direct_output, 115 }; 116 117 struct neigh_table nd_tbl = { 118 .family = AF_INET6, 119 .key_len = sizeof(struct in6_addr), 120 .hash = ndisc_hash, 121 .constructor = ndisc_constructor, 122 .pconstructor = pndisc_constructor, 123 .pdestructor = pndisc_destructor, 124 .proxy_redo = pndisc_redo, 125 .id = "ndisc_cache", 126 .parms = { 127 .tbl = &nd_tbl, 128 .reachable_time = ND_REACHABLE_TIME, 129 .data = { 130 [NEIGH_VAR_MCAST_PROBES] = 3, 131 [NEIGH_VAR_UCAST_PROBES] = 3, 132 [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER, 133 [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME, 134 [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ, 135 [NEIGH_VAR_GC_STALETIME] = 60 * HZ, 136 [NEIGH_VAR_QUEUE_LEN_BYTES] = 64 * 1024, 137 [NEIGH_VAR_PROXY_QLEN] = 64, 138 [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ, 139 [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10, 140 }, 141 }, 142 .gc_interval = 30 * HZ, 143 .gc_thresh1 = 128, 144 .gc_thresh2 = 512, 145 .gc_thresh3 = 1024, 146 }; 147 148 static void ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data) 149 { 150 int pad = ndisc_addr_option_pad(skb->dev->type); 151 int data_len = skb->dev->addr_len; 152 int space = ndisc_opt_addr_space(skb->dev); 153 u8 *opt = skb_put(skb, space); 154 155 opt[0] = type; 156 opt[1] = space>>3; 157 158 memset(opt + 2, 0, pad); 159 opt += pad; 160 space -= pad; 161 162 memcpy(opt+2, data, data_len); 163 data_len += 2; 164 opt += data_len; 165 space -= data_len; 166 if (space > 0) 167 memset(opt, 0, space); 168 } 169 170 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur, 171 struct nd_opt_hdr *end) 172 { 173 int type; 174 if (!cur || !end || cur >= end) 175 return NULL; 176 type = cur->nd_opt_type; 177 do { 178 cur = ((void *)cur) + (cur->nd_opt_len << 3); 179 } while (cur < end && cur->nd_opt_type != type); 180 return cur <= end && cur->nd_opt_type == type ? cur : NULL; 181 } 182 183 static inline int ndisc_is_useropt(struct nd_opt_hdr *opt) 184 { 185 return opt->nd_opt_type == ND_OPT_RDNSS || 186 opt->nd_opt_type == ND_OPT_DNSSL; 187 } 188 189 static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur, 190 struct nd_opt_hdr *end) 191 { 192 if (!cur || !end || cur >= end) 193 return NULL; 194 do { 195 cur = ((void *)cur) + (cur->nd_opt_len << 3); 196 } while (cur < end && !ndisc_is_useropt(cur)); 197 return cur <= end && ndisc_is_useropt(cur) ? cur : NULL; 198 } 199 200 struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len, 201 struct ndisc_options *ndopts) 202 { 203 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt; 204 205 if (!nd_opt || opt_len < 0 || !ndopts) 206 return NULL; 207 memset(ndopts, 0, sizeof(*ndopts)); 208 while (opt_len) { 209 int l; 210 if (opt_len < sizeof(struct nd_opt_hdr)) 211 return NULL; 212 l = nd_opt->nd_opt_len << 3; 213 if (opt_len < l || l == 0) 214 return NULL; 215 switch (nd_opt->nd_opt_type) { 216 case ND_OPT_SOURCE_LL_ADDR: 217 case ND_OPT_TARGET_LL_ADDR: 218 case ND_OPT_MTU: 219 case ND_OPT_REDIRECT_HDR: 220 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { 221 ND_PRINTK(2, warn, 222 "%s: duplicated ND6 option found: type=%d\n", 223 __func__, nd_opt->nd_opt_type); 224 } else { 225 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; 226 } 227 break; 228 case ND_OPT_PREFIX_INFO: 229 ndopts->nd_opts_pi_end = nd_opt; 230 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type]) 231 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; 232 break; 233 #ifdef CONFIG_IPV6_ROUTE_INFO 234 case ND_OPT_ROUTE_INFO: 235 ndopts->nd_opts_ri_end = nd_opt; 236 if (!ndopts->nd_opts_ri) 237 ndopts->nd_opts_ri = nd_opt; 238 break; 239 #endif 240 default: 241 if (ndisc_is_useropt(nd_opt)) { 242 ndopts->nd_useropts_end = nd_opt; 243 if (!ndopts->nd_useropts) 244 ndopts->nd_useropts = nd_opt; 245 } else { 246 /* 247 * Unknown options must be silently ignored, 248 * to accommodate future extension to the 249 * protocol. 250 */ 251 ND_PRINTK(2, notice, 252 "%s: ignored unsupported option; type=%d, len=%d\n", 253 __func__, 254 nd_opt->nd_opt_type, 255 nd_opt->nd_opt_len); 256 } 257 } 258 opt_len -= l; 259 nd_opt = ((void *)nd_opt) + l; 260 } 261 return ndopts; 262 } 263 264 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir) 265 { 266 switch (dev->type) { 267 case ARPHRD_ETHER: 268 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */ 269 case ARPHRD_FDDI: 270 ipv6_eth_mc_map(addr, buf); 271 return 0; 272 case ARPHRD_ARCNET: 273 ipv6_arcnet_mc_map(addr, buf); 274 return 0; 275 case ARPHRD_INFINIBAND: 276 ipv6_ib_mc_map(addr, dev->broadcast, buf); 277 return 0; 278 case ARPHRD_IPGRE: 279 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf); 280 default: 281 if (dir) { 282 memcpy(buf, dev->broadcast, dev->addr_len); 283 return 0; 284 } 285 } 286 return -EINVAL; 287 } 288 EXPORT_SYMBOL(ndisc_mc_map); 289 290 static u32 ndisc_hash(const void *pkey, 291 const struct net_device *dev, 292 __u32 *hash_rnd) 293 { 294 return ndisc_hashfn(pkey, dev, hash_rnd); 295 } 296 297 static int ndisc_constructor(struct neighbour *neigh) 298 { 299 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key; 300 struct net_device *dev = neigh->dev; 301 struct inet6_dev *in6_dev; 302 struct neigh_parms *parms; 303 bool is_multicast = ipv6_addr_is_multicast(addr); 304 305 in6_dev = in6_dev_get(dev); 306 if (in6_dev == NULL) { 307 return -EINVAL; 308 } 309 310 parms = in6_dev->nd_parms; 311 __neigh_parms_put(neigh->parms); 312 neigh->parms = neigh_parms_clone(parms); 313 314 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST; 315 if (!dev->header_ops) { 316 neigh->nud_state = NUD_NOARP; 317 neigh->ops = &ndisc_direct_ops; 318 neigh->output = neigh_direct_output; 319 } else { 320 if (is_multicast) { 321 neigh->nud_state = NUD_NOARP; 322 ndisc_mc_map(addr, neigh->ha, dev, 1); 323 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { 324 neigh->nud_state = NUD_NOARP; 325 memcpy(neigh->ha, dev->dev_addr, dev->addr_len); 326 if (dev->flags&IFF_LOOPBACK) 327 neigh->type = RTN_LOCAL; 328 } else if (dev->flags&IFF_POINTOPOINT) { 329 neigh->nud_state = NUD_NOARP; 330 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 331 } 332 if (dev->header_ops->cache) 333 neigh->ops = &ndisc_hh_ops; 334 else 335 neigh->ops = &ndisc_generic_ops; 336 if (neigh->nud_state&NUD_VALID) 337 neigh->output = neigh->ops->connected_output; 338 else 339 neigh->output = neigh->ops->output; 340 } 341 in6_dev_put(in6_dev); 342 return 0; 343 } 344 345 static int pndisc_constructor(struct pneigh_entry *n) 346 { 347 struct in6_addr *addr = (struct in6_addr *)&n->key; 348 struct in6_addr maddr; 349 struct net_device *dev = n->dev; 350 351 if (dev == NULL || __in6_dev_get(dev) == NULL) 352 return -EINVAL; 353 addrconf_addr_solict_mult(addr, &maddr); 354 ipv6_dev_mc_inc(dev, &maddr); 355 return 0; 356 } 357 358 static void pndisc_destructor(struct pneigh_entry *n) 359 { 360 struct in6_addr *addr = (struct in6_addr *)&n->key; 361 struct in6_addr maddr; 362 struct net_device *dev = n->dev; 363 364 if (dev == NULL || __in6_dev_get(dev) == NULL) 365 return; 366 addrconf_addr_solict_mult(addr, &maddr); 367 ipv6_dev_mc_dec(dev, &maddr); 368 } 369 370 static struct sk_buff *ndisc_alloc_skb(struct net_device *dev, 371 int len) 372 { 373 int hlen = LL_RESERVED_SPACE(dev); 374 int tlen = dev->needed_tailroom; 375 struct sock *sk = dev_net(dev)->ipv6.ndisc_sk; 376 struct sk_buff *skb; 377 378 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC); 379 if (!skb) { 380 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n", 381 __func__); 382 return NULL; 383 } 384 385 skb->protocol = htons(ETH_P_IPV6); 386 skb->dev = dev; 387 388 skb_reserve(skb, hlen + sizeof(struct ipv6hdr)); 389 skb_reset_transport_header(skb); 390 391 /* Manually assign socket ownership as we avoid calling 392 * sock_alloc_send_pskb() to bypass wmem buffer limits 393 */ 394 skb_set_owner_w(skb, sk); 395 396 return skb; 397 } 398 399 static void ip6_nd_hdr(struct sk_buff *skb, 400 const struct in6_addr *saddr, 401 const struct in6_addr *daddr, 402 int hop_limit, int len) 403 { 404 struct ipv6hdr *hdr; 405 406 skb_push(skb, sizeof(*hdr)); 407 skb_reset_network_header(skb); 408 hdr = ipv6_hdr(skb); 409 410 ip6_flow_hdr(hdr, 0, 0); 411 412 hdr->payload_len = htons(len); 413 hdr->nexthdr = IPPROTO_ICMPV6; 414 hdr->hop_limit = hop_limit; 415 416 hdr->saddr = *saddr; 417 hdr->daddr = *daddr; 418 } 419 420 static void ndisc_send_skb(struct sk_buff *skb, 421 const struct in6_addr *daddr, 422 const struct in6_addr *saddr) 423 { 424 struct dst_entry *dst = skb_dst(skb); 425 struct net *net = dev_net(skb->dev); 426 struct sock *sk = net->ipv6.ndisc_sk; 427 struct inet6_dev *idev; 428 int err; 429 struct icmp6hdr *icmp6h = icmp6_hdr(skb); 430 u8 type; 431 432 type = icmp6h->icmp6_type; 433 434 if (!dst) { 435 struct flowi6 fl6; 436 437 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, skb->dev->ifindex); 438 dst = icmp6_dst_alloc(skb->dev, &fl6); 439 if (IS_ERR(dst)) { 440 kfree_skb(skb); 441 return; 442 } 443 444 skb_dst_set(skb, dst); 445 } 446 447 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len, 448 IPPROTO_ICMPV6, 449 csum_partial(icmp6h, 450 skb->len, 0)); 451 452 ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len); 453 454 rcu_read_lock(); 455 idev = __in6_dev_get(dst->dev); 456 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len); 457 458 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev, 459 dst_output); 460 if (!err) { 461 ICMP6MSGOUT_INC_STATS(net, idev, type); 462 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 463 } 464 465 rcu_read_unlock(); 466 } 467 468 void ndisc_send_na(struct net_device *dev, struct neighbour *neigh, 469 const struct in6_addr *daddr, 470 const struct in6_addr *solicited_addr, 471 bool router, bool solicited, bool override, bool inc_opt) 472 { 473 struct sk_buff *skb; 474 struct in6_addr tmpaddr; 475 struct inet6_ifaddr *ifp; 476 const struct in6_addr *src_addr; 477 struct nd_msg *msg; 478 int optlen = 0; 479 480 /* for anycast or proxy, solicited_addr != src_addr */ 481 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1); 482 if (ifp) { 483 src_addr = solicited_addr; 484 if (ifp->flags & IFA_F_OPTIMISTIC) 485 override = false; 486 inc_opt |= ifp->idev->cnf.force_tllao; 487 in6_ifa_put(ifp); 488 } else { 489 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr, 490 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs, 491 &tmpaddr)) 492 return; 493 src_addr = &tmpaddr; 494 } 495 496 if (!dev->addr_len) 497 inc_opt = 0; 498 if (inc_opt) 499 optlen += ndisc_opt_addr_space(dev); 500 501 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 502 if (!skb) 503 return; 504 505 msg = (struct nd_msg *)skb_put(skb, sizeof(*msg)); 506 *msg = (struct nd_msg) { 507 .icmph = { 508 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT, 509 .icmp6_router = router, 510 .icmp6_solicited = solicited, 511 .icmp6_override = override, 512 }, 513 .target = *solicited_addr, 514 }; 515 516 if (inc_opt) 517 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, 518 dev->dev_addr); 519 520 521 ndisc_send_skb(skb, daddr, src_addr); 522 } 523 524 static void ndisc_send_unsol_na(struct net_device *dev) 525 { 526 struct inet6_dev *idev; 527 struct inet6_ifaddr *ifa; 528 529 idev = in6_dev_get(dev); 530 if (!idev) 531 return; 532 533 read_lock_bh(&idev->lock); 534 list_for_each_entry(ifa, &idev->addr_list, if_list) { 535 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &ifa->addr, 536 /*router=*/ !!idev->cnf.forwarding, 537 /*solicited=*/ false, /*override=*/ true, 538 /*inc_opt=*/ true); 539 } 540 read_unlock_bh(&idev->lock); 541 542 in6_dev_put(idev); 543 } 544 545 void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh, 546 const struct in6_addr *solicit, 547 const struct in6_addr *daddr, const struct in6_addr *saddr) 548 { 549 struct sk_buff *skb; 550 struct in6_addr addr_buf; 551 int inc_opt = dev->addr_len; 552 int optlen = 0; 553 struct nd_msg *msg; 554 555 if (saddr == NULL) { 556 if (ipv6_get_lladdr(dev, &addr_buf, 557 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))) 558 return; 559 saddr = &addr_buf; 560 } 561 562 if (ipv6_addr_any(saddr)) 563 inc_opt = false; 564 if (inc_opt) 565 optlen += ndisc_opt_addr_space(dev); 566 567 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 568 if (!skb) 569 return; 570 571 msg = (struct nd_msg *)skb_put(skb, sizeof(*msg)); 572 *msg = (struct nd_msg) { 573 .icmph = { 574 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION, 575 }, 576 .target = *solicit, 577 }; 578 579 if (inc_opt) 580 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR, 581 dev->dev_addr); 582 583 ndisc_send_skb(skb, daddr, saddr); 584 } 585 586 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr, 587 const struct in6_addr *daddr) 588 { 589 struct sk_buff *skb; 590 struct rs_msg *msg; 591 int send_sllao = dev->addr_len; 592 int optlen = 0; 593 594 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 595 /* 596 * According to section 2.2 of RFC 4429, we must not 597 * send router solicitations with a sllao from 598 * optimistic addresses, but we may send the solicitation 599 * if we don't include the sllao. So here we check 600 * if our address is optimistic, and if so, we 601 * suppress the inclusion of the sllao. 602 */ 603 if (send_sllao) { 604 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr, 605 dev, 1); 606 if (ifp) { 607 if (ifp->flags & IFA_F_OPTIMISTIC) { 608 send_sllao = 0; 609 } 610 in6_ifa_put(ifp); 611 } else { 612 send_sllao = 0; 613 } 614 } 615 #endif 616 if (send_sllao) 617 optlen += ndisc_opt_addr_space(dev); 618 619 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 620 if (!skb) 621 return; 622 623 msg = (struct rs_msg *)skb_put(skb, sizeof(*msg)); 624 *msg = (struct rs_msg) { 625 .icmph = { 626 .icmp6_type = NDISC_ROUTER_SOLICITATION, 627 }, 628 }; 629 630 if (send_sllao) 631 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR, 632 dev->dev_addr); 633 634 ndisc_send_skb(skb, daddr, saddr); 635 } 636 637 638 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb) 639 { 640 /* 641 * "The sender MUST return an ICMP 642 * destination unreachable" 643 */ 644 dst_link_failure(skb); 645 kfree_skb(skb); 646 } 647 648 /* Called with locked neigh: either read or both */ 649 650 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb) 651 { 652 struct in6_addr *saddr = NULL; 653 struct in6_addr mcaddr; 654 struct net_device *dev = neigh->dev; 655 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key; 656 int probes = atomic_read(&neigh->probes); 657 658 if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1)) 659 saddr = &ipv6_hdr(skb)->saddr; 660 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES); 661 if (probes < 0) { 662 if (!(neigh->nud_state & NUD_VALID)) { 663 ND_PRINTK(1, dbg, 664 "%s: trying to ucast probe in NUD_INVALID: %pI6\n", 665 __func__, target); 666 } 667 ndisc_send_ns(dev, neigh, target, target, saddr); 668 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) { 669 neigh_app_ns(neigh); 670 } else { 671 addrconf_addr_solict_mult(target, &mcaddr); 672 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr); 673 } 674 } 675 676 static int pndisc_is_router(const void *pkey, 677 struct net_device *dev) 678 { 679 struct pneigh_entry *n; 680 int ret = -1; 681 682 read_lock_bh(&nd_tbl.lock); 683 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev); 684 if (n) 685 ret = !!(n->flags & NTF_ROUTER); 686 read_unlock_bh(&nd_tbl.lock); 687 688 return ret; 689 } 690 691 static void ndisc_recv_ns(struct sk_buff *skb) 692 { 693 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 694 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 695 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 696 u8 *lladdr = NULL; 697 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 698 offsetof(struct nd_msg, opt)); 699 struct ndisc_options ndopts; 700 struct net_device *dev = skb->dev; 701 struct inet6_ifaddr *ifp; 702 struct inet6_dev *idev = NULL; 703 struct neighbour *neigh; 704 int dad = ipv6_addr_any(saddr); 705 bool inc; 706 int is_router = -1; 707 708 if (skb->len < sizeof(struct nd_msg)) { 709 ND_PRINTK(2, warn, "NS: packet too short\n"); 710 return; 711 } 712 713 if (ipv6_addr_is_multicast(&msg->target)) { 714 ND_PRINTK(2, warn, "NS: multicast target address\n"); 715 return; 716 } 717 718 /* 719 * RFC2461 7.1.1: 720 * DAD has to be destined for solicited node multicast address. 721 */ 722 if (dad && !ipv6_addr_is_solict_mult(daddr)) { 723 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n"); 724 return; 725 } 726 727 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { 728 ND_PRINTK(2, warn, "NS: invalid ND options\n"); 729 return; 730 } 731 732 if (ndopts.nd_opts_src_lladdr) { 733 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev); 734 if (!lladdr) { 735 ND_PRINTK(2, warn, 736 "NS: invalid link-layer address length\n"); 737 return; 738 } 739 740 /* RFC2461 7.1.1: 741 * If the IP source address is the unspecified address, 742 * there MUST NOT be source link-layer address option 743 * in the message. 744 */ 745 if (dad) { 746 ND_PRINTK(2, warn, 747 "NS: bad DAD packet (link-layer address option)\n"); 748 return; 749 } 750 } 751 752 inc = ipv6_addr_is_multicast(daddr); 753 754 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); 755 if (ifp) { 756 757 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) { 758 if (dad) { 759 /* 760 * We are colliding with another node 761 * who is doing DAD 762 * so fail our DAD process 763 */ 764 addrconf_dad_failure(ifp); 765 return; 766 } else { 767 /* 768 * This is not a dad solicitation. 769 * If we are an optimistic node, 770 * we should respond. 771 * Otherwise, we should ignore it. 772 */ 773 if (!(ifp->flags & IFA_F_OPTIMISTIC)) 774 goto out; 775 } 776 } 777 778 idev = ifp->idev; 779 } else { 780 struct net *net = dev_net(dev); 781 782 idev = in6_dev_get(dev); 783 if (!idev) { 784 /* XXX: count this drop? */ 785 return; 786 } 787 788 if (ipv6_chk_acast_addr(net, dev, &msg->target) || 789 (idev->cnf.forwarding && 790 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) && 791 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) { 792 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) && 793 skb->pkt_type != PACKET_HOST && 794 inc && 795 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) { 796 /* 797 * for anycast or proxy, 798 * sender should delay its response 799 * by a random time between 0 and 800 * MAX_ANYCAST_DELAY_TIME seconds. 801 * (RFC2461) -- yoshfuji 802 */ 803 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC); 804 if (n) 805 pneigh_enqueue(&nd_tbl, idev->nd_parms, n); 806 goto out; 807 } 808 } else 809 goto out; 810 } 811 812 if (is_router < 0) 813 is_router = idev->cnf.forwarding; 814 815 if (dad) { 816 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target, 817 !!is_router, false, (ifp != NULL), true); 818 goto out; 819 } 820 821 if (inc) 822 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast); 823 else 824 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast); 825 826 /* 827 * update / create cache entry 828 * for the source address 829 */ 830 neigh = __neigh_lookup(&nd_tbl, saddr, dev, 831 !inc || lladdr || !dev->addr_len); 832 if (neigh) 833 neigh_update(neigh, lladdr, NUD_STALE, 834 NEIGH_UPDATE_F_WEAK_OVERRIDE| 835 NEIGH_UPDATE_F_OVERRIDE); 836 if (neigh || !dev->header_ops) { 837 ndisc_send_na(dev, neigh, saddr, &msg->target, 838 !!is_router, 839 true, (ifp != NULL && inc), inc); 840 if (neigh) 841 neigh_release(neigh); 842 } 843 844 out: 845 if (ifp) 846 in6_ifa_put(ifp); 847 else 848 in6_dev_put(idev); 849 } 850 851 static void ndisc_recv_na(struct sk_buff *skb) 852 { 853 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 854 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 855 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 856 u8 *lladdr = NULL; 857 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 858 offsetof(struct nd_msg, opt)); 859 struct ndisc_options ndopts; 860 struct net_device *dev = skb->dev; 861 struct inet6_ifaddr *ifp; 862 struct neighbour *neigh; 863 864 if (skb->len < sizeof(struct nd_msg)) { 865 ND_PRINTK(2, warn, "NA: packet too short\n"); 866 return; 867 } 868 869 if (ipv6_addr_is_multicast(&msg->target)) { 870 ND_PRINTK(2, warn, "NA: target address is multicast\n"); 871 return; 872 } 873 874 if (ipv6_addr_is_multicast(daddr) && 875 msg->icmph.icmp6_solicited) { 876 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n"); 877 return; 878 } 879 880 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { 881 ND_PRINTK(2, warn, "NS: invalid ND option\n"); 882 return; 883 } 884 if (ndopts.nd_opts_tgt_lladdr) { 885 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev); 886 if (!lladdr) { 887 ND_PRINTK(2, warn, 888 "NA: invalid link-layer address length\n"); 889 return; 890 } 891 } 892 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); 893 if (ifp) { 894 if (skb->pkt_type != PACKET_LOOPBACK 895 && (ifp->flags & IFA_F_TENTATIVE)) { 896 addrconf_dad_failure(ifp); 897 return; 898 } 899 /* What should we make now? The advertisement 900 is invalid, but ndisc specs say nothing 901 about it. It could be misconfiguration, or 902 an smart proxy agent tries to help us :-) 903 904 We should not print the error if NA has been 905 received from loopback - it is just our own 906 unsolicited advertisement. 907 */ 908 if (skb->pkt_type != PACKET_LOOPBACK) 909 ND_PRINTK(1, warn, 910 "NA: someone advertises our address %pI6 on %s!\n", 911 &ifp->addr, ifp->idev->dev->name); 912 in6_ifa_put(ifp); 913 return; 914 } 915 neigh = neigh_lookup(&nd_tbl, &msg->target, dev); 916 917 if (neigh) { 918 u8 old_flags = neigh->flags; 919 struct net *net = dev_net(dev); 920 921 if (neigh->nud_state & NUD_FAILED) 922 goto out; 923 924 /* 925 * Don't update the neighbor cache entry on a proxy NA from 926 * ourselves because either the proxied node is off link or it 927 * has already sent a NA to us. 928 */ 929 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) && 930 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp && 931 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) { 932 /* XXX: idev->cnf.proxy_ndp */ 933 goto out; 934 } 935 936 neigh_update(neigh, lladdr, 937 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE, 938 NEIGH_UPDATE_F_WEAK_OVERRIDE| 939 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)| 940 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 941 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0)); 942 943 if ((old_flags & ~neigh->flags) & NTF_ROUTER) { 944 /* 945 * Change: router to host 946 */ 947 rt6_clean_tohost(dev_net(dev), saddr); 948 } 949 950 out: 951 neigh_release(neigh); 952 } 953 } 954 955 static void ndisc_recv_rs(struct sk_buff *skb) 956 { 957 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb); 958 unsigned long ndoptlen = skb->len - sizeof(*rs_msg); 959 struct neighbour *neigh; 960 struct inet6_dev *idev; 961 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 962 struct ndisc_options ndopts; 963 u8 *lladdr = NULL; 964 965 if (skb->len < sizeof(*rs_msg)) 966 return; 967 968 idev = __in6_dev_get(skb->dev); 969 if (!idev) { 970 ND_PRINTK(1, err, "RS: can't find in6 device\n"); 971 return; 972 } 973 974 /* Don't accept RS if we're not in router mode */ 975 if (!idev->cnf.forwarding) 976 goto out; 977 978 /* 979 * Don't update NCE if src = ::; 980 * this implies that the source node has no ip address assigned yet. 981 */ 982 if (ipv6_addr_any(saddr)) 983 goto out; 984 985 /* Parse ND options */ 986 if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) { 987 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n"); 988 goto out; 989 } 990 991 if (ndopts.nd_opts_src_lladdr) { 992 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 993 skb->dev); 994 if (!lladdr) 995 goto out; 996 } 997 998 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1); 999 if (neigh) { 1000 neigh_update(neigh, lladdr, NUD_STALE, 1001 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1002 NEIGH_UPDATE_F_OVERRIDE| 1003 NEIGH_UPDATE_F_OVERRIDE_ISROUTER); 1004 neigh_release(neigh); 1005 } 1006 out: 1007 return; 1008 } 1009 1010 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt) 1011 { 1012 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra); 1013 struct sk_buff *skb; 1014 struct nlmsghdr *nlh; 1015 struct nduseroptmsg *ndmsg; 1016 struct net *net = dev_net(ra->dev); 1017 int err; 1018 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg) 1019 + (opt->nd_opt_len << 3)); 1020 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr)); 1021 1022 skb = nlmsg_new(msg_size, GFP_ATOMIC); 1023 if (skb == NULL) { 1024 err = -ENOBUFS; 1025 goto errout; 1026 } 1027 1028 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0); 1029 if (nlh == NULL) { 1030 goto nla_put_failure; 1031 } 1032 1033 ndmsg = nlmsg_data(nlh); 1034 ndmsg->nduseropt_family = AF_INET6; 1035 ndmsg->nduseropt_ifindex = ra->dev->ifindex; 1036 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type; 1037 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code; 1038 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3; 1039 1040 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3); 1041 1042 if (nla_put(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr), 1043 &ipv6_hdr(ra)->saddr)) 1044 goto nla_put_failure; 1045 nlmsg_end(skb, nlh); 1046 1047 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC); 1048 return; 1049 1050 nla_put_failure: 1051 nlmsg_free(skb); 1052 err = -EMSGSIZE; 1053 errout: 1054 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err); 1055 } 1056 1057 static void ndisc_router_discovery(struct sk_buff *skb) 1058 { 1059 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb); 1060 struct neighbour *neigh = NULL; 1061 struct inet6_dev *in6_dev; 1062 struct rt6_info *rt = NULL; 1063 int lifetime; 1064 struct ndisc_options ndopts; 1065 int optlen; 1066 unsigned int pref = 0; 1067 1068 __u8 *opt = (__u8 *)(ra_msg + 1); 1069 1070 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) - 1071 sizeof(struct ra_msg); 1072 1073 ND_PRINTK(2, info, 1074 "RA: %s, dev: %s\n", 1075 __func__, skb->dev->name); 1076 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1077 ND_PRINTK(2, warn, "RA: source address is not link-local\n"); 1078 return; 1079 } 1080 if (optlen < 0) { 1081 ND_PRINTK(2, warn, "RA: packet too short\n"); 1082 return; 1083 } 1084 1085 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1086 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) { 1087 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n"); 1088 return; 1089 } 1090 #endif 1091 1092 /* 1093 * set the RA_RECV flag in the interface 1094 */ 1095 1096 in6_dev = __in6_dev_get(skb->dev); 1097 if (in6_dev == NULL) { 1098 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n", 1099 skb->dev->name); 1100 return; 1101 } 1102 1103 if (!ndisc_parse_options(opt, optlen, &ndopts)) { 1104 ND_PRINTK(2, warn, "RA: invalid ND options\n"); 1105 return; 1106 } 1107 1108 if (!ipv6_accept_ra(in6_dev)) { 1109 ND_PRINTK(2, info, 1110 "RA: %s, did not accept ra for dev: %s\n", 1111 __func__, skb->dev->name); 1112 goto skip_linkparms; 1113 } 1114 1115 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1116 /* skip link-specific parameters from interior routers */ 1117 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1118 ND_PRINTK(2, info, 1119 "RA: %s, nodetype is NODEFAULT, dev: %s\n", 1120 __func__, skb->dev->name); 1121 goto skip_linkparms; 1122 } 1123 #endif 1124 1125 if (in6_dev->if_flags & IF_RS_SENT) { 1126 /* 1127 * flag that an RA was received after an RS was sent 1128 * out on this interface. 1129 */ 1130 in6_dev->if_flags |= IF_RA_RCVD; 1131 } 1132 1133 /* 1134 * Remember the managed/otherconf flags from most recently 1135 * received RA message (RFC 2462) -- yoshfuji 1136 */ 1137 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED | 1138 IF_RA_OTHERCONF)) | 1139 (ra_msg->icmph.icmp6_addrconf_managed ? 1140 IF_RA_MANAGED : 0) | 1141 (ra_msg->icmph.icmp6_addrconf_other ? 1142 IF_RA_OTHERCONF : 0); 1143 1144 if (!in6_dev->cnf.accept_ra_defrtr) { 1145 ND_PRINTK(2, info, 1146 "RA: %s, defrtr is false for dev: %s\n", 1147 __func__, skb->dev->name); 1148 goto skip_defrtr; 1149 } 1150 1151 /* Do not accept RA with source-addr found on local machine unless 1152 * accept_ra_from_local is set to true. 1153 */ 1154 if (!in6_dev->cnf.accept_ra_from_local && 1155 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, 1156 NULL, 0)) { 1157 ND_PRINTK(2, info, 1158 "RA from local address detected on dev: %s: default router ignored\n", 1159 skb->dev->name); 1160 goto skip_defrtr; 1161 } 1162 1163 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); 1164 1165 #ifdef CONFIG_IPV6_ROUTER_PREF 1166 pref = ra_msg->icmph.icmp6_router_pref; 1167 /* 10b is handled as if it were 00b (medium) */ 1168 if (pref == ICMPV6_ROUTER_PREF_INVALID || 1169 !in6_dev->cnf.accept_ra_rtr_pref) 1170 pref = ICMPV6_ROUTER_PREF_MEDIUM; 1171 #endif 1172 1173 rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev); 1174 1175 if (rt) { 1176 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr); 1177 if (!neigh) { 1178 ND_PRINTK(0, err, 1179 "RA: %s got default router without neighbour\n", 1180 __func__); 1181 ip6_rt_put(rt); 1182 return; 1183 } 1184 } 1185 if (rt && lifetime == 0) { 1186 ip6_del_rt(rt); 1187 rt = NULL; 1188 } 1189 1190 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, for dev: %s\n", 1191 rt, lifetime, skb->dev->name); 1192 if (rt == NULL && lifetime) { 1193 ND_PRINTK(3, info, "RA: adding default router\n"); 1194 1195 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref); 1196 if (rt == NULL) { 1197 ND_PRINTK(0, err, 1198 "RA: %s failed to add default route\n", 1199 __func__); 1200 return; 1201 } 1202 1203 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr); 1204 if (neigh == NULL) { 1205 ND_PRINTK(0, err, 1206 "RA: %s got default router without neighbour\n", 1207 __func__); 1208 ip6_rt_put(rt); 1209 return; 1210 } 1211 neigh->flags |= NTF_ROUTER; 1212 } else if (rt) { 1213 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 1214 } 1215 1216 if (rt) 1217 rt6_set_expires(rt, jiffies + (HZ * lifetime)); 1218 if (ra_msg->icmph.icmp6_hop_limit) { 1219 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit; 1220 if (rt) 1221 dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 1222 ra_msg->icmph.icmp6_hop_limit); 1223 } 1224 1225 skip_defrtr: 1226 1227 /* 1228 * Update Reachable Time and Retrans Timer 1229 */ 1230 1231 if (in6_dev->nd_parms) { 1232 unsigned long rtime = ntohl(ra_msg->retrans_timer); 1233 1234 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) { 1235 rtime = (rtime*HZ)/1000; 1236 if (rtime < HZ/10) 1237 rtime = HZ/10; 1238 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime); 1239 in6_dev->tstamp = jiffies; 1240 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1241 } 1242 1243 rtime = ntohl(ra_msg->reachable_time); 1244 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) { 1245 rtime = (rtime*HZ)/1000; 1246 1247 if (rtime < HZ/10) 1248 rtime = HZ/10; 1249 1250 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) { 1251 NEIGH_VAR_SET(in6_dev->nd_parms, 1252 BASE_REACHABLE_TIME, rtime); 1253 NEIGH_VAR_SET(in6_dev->nd_parms, 1254 GC_STALETIME, 3 * rtime); 1255 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime); 1256 in6_dev->tstamp = jiffies; 1257 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1258 } 1259 } 1260 } 1261 1262 skip_linkparms: 1263 1264 /* 1265 * Process options. 1266 */ 1267 1268 if (!neigh) 1269 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr, 1270 skb->dev, 1); 1271 if (neigh) { 1272 u8 *lladdr = NULL; 1273 if (ndopts.nd_opts_src_lladdr) { 1274 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1275 skb->dev); 1276 if (!lladdr) { 1277 ND_PRINTK(2, warn, 1278 "RA: invalid link-layer address length\n"); 1279 goto out; 1280 } 1281 } 1282 neigh_update(neigh, lladdr, NUD_STALE, 1283 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1284 NEIGH_UPDATE_F_OVERRIDE| 1285 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1286 NEIGH_UPDATE_F_ISROUTER); 1287 } 1288 1289 if (!ipv6_accept_ra(in6_dev)) { 1290 ND_PRINTK(2, info, 1291 "RA: %s, accept_ra is false for dev: %s\n", 1292 __func__, skb->dev->name); 1293 goto out; 1294 } 1295 1296 #ifdef CONFIG_IPV6_ROUTE_INFO 1297 if (!in6_dev->cnf.accept_ra_from_local && 1298 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, 1299 NULL, 0)) { 1300 ND_PRINTK(2, info, 1301 "RA from local address detected on dev: %s: router info ignored.\n", 1302 skb->dev->name); 1303 goto skip_routeinfo; 1304 } 1305 1306 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) { 1307 struct nd_opt_hdr *p; 1308 for (p = ndopts.nd_opts_ri; 1309 p; 1310 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) { 1311 struct route_info *ri = (struct route_info *)p; 1312 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1313 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT && 1314 ri->prefix_len == 0) 1315 continue; 1316 #endif 1317 if (ri->prefix_len == 0 && 1318 !in6_dev->cnf.accept_ra_defrtr) 1319 continue; 1320 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen) 1321 continue; 1322 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3, 1323 &ipv6_hdr(skb)->saddr); 1324 } 1325 } 1326 1327 skip_routeinfo: 1328 #endif 1329 1330 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1331 /* skip link-specific ndopts from interior routers */ 1332 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1333 ND_PRINTK(2, info, 1334 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n", 1335 __func__, skb->dev->name); 1336 goto out; 1337 } 1338 #endif 1339 1340 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) { 1341 struct nd_opt_hdr *p; 1342 for (p = ndopts.nd_opts_pi; 1343 p; 1344 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) { 1345 addrconf_prefix_rcv(skb->dev, (u8 *)p, 1346 (p->nd_opt_len) << 3, 1347 ndopts.nd_opts_src_lladdr != NULL); 1348 } 1349 } 1350 1351 if (ndopts.nd_opts_mtu) { 1352 __be32 n; 1353 u32 mtu; 1354 1355 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); 1356 mtu = ntohl(n); 1357 1358 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { 1359 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu); 1360 } else if (in6_dev->cnf.mtu6 != mtu) { 1361 in6_dev->cnf.mtu6 = mtu; 1362 1363 if (rt) 1364 dst_metric_set(&rt->dst, RTAX_MTU, mtu); 1365 1366 rt6_mtu_change(skb->dev, mtu); 1367 } 1368 } 1369 1370 if (ndopts.nd_useropts) { 1371 struct nd_opt_hdr *p; 1372 for (p = ndopts.nd_useropts; 1373 p; 1374 p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) { 1375 ndisc_ra_useropt(skb, p); 1376 } 1377 } 1378 1379 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { 1380 ND_PRINTK(2, warn, "RA: invalid RA options\n"); 1381 } 1382 out: 1383 ip6_rt_put(rt); 1384 if (neigh) 1385 neigh_release(neigh); 1386 } 1387 1388 static void ndisc_redirect_rcv(struct sk_buff *skb) 1389 { 1390 u8 *hdr; 1391 struct ndisc_options ndopts; 1392 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb); 1393 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 1394 offsetof(struct rd_msg, opt)); 1395 1396 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1397 switch (skb->ndisc_nodetype) { 1398 case NDISC_NODETYPE_HOST: 1399 case NDISC_NODETYPE_NODEFAULT: 1400 ND_PRINTK(2, warn, 1401 "Redirect: from host or unauthorized router\n"); 1402 return; 1403 } 1404 #endif 1405 1406 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1407 ND_PRINTK(2, warn, 1408 "Redirect: source address is not link-local\n"); 1409 return; 1410 } 1411 1412 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) 1413 return; 1414 1415 if (!ndopts.nd_opts_rh) { 1416 ip6_redirect_no_header(skb, dev_net(skb->dev), 1417 skb->dev->ifindex, 0); 1418 return; 1419 } 1420 1421 hdr = (u8 *)ndopts.nd_opts_rh; 1422 hdr += 8; 1423 if (!pskb_pull(skb, hdr - skb_transport_header(skb))) 1424 return; 1425 1426 icmpv6_notify(skb, NDISC_REDIRECT, 0, 0); 1427 } 1428 1429 static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb, 1430 struct sk_buff *orig_skb, 1431 int rd_len) 1432 { 1433 u8 *opt = skb_put(skb, rd_len); 1434 1435 memset(opt, 0, 8); 1436 *(opt++) = ND_OPT_REDIRECT_HDR; 1437 *(opt++) = (rd_len >> 3); 1438 opt += 6; 1439 1440 memcpy(opt, ipv6_hdr(orig_skb), rd_len - 8); 1441 } 1442 1443 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target) 1444 { 1445 struct net_device *dev = skb->dev; 1446 struct net *net = dev_net(dev); 1447 struct sock *sk = net->ipv6.ndisc_sk; 1448 int optlen = 0; 1449 struct inet_peer *peer; 1450 struct sk_buff *buff; 1451 struct rd_msg *msg; 1452 struct in6_addr saddr_buf; 1453 struct rt6_info *rt; 1454 struct dst_entry *dst; 1455 struct flowi6 fl6; 1456 int rd_len; 1457 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL; 1458 bool ret; 1459 1460 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) { 1461 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n", 1462 dev->name); 1463 return; 1464 } 1465 1466 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) && 1467 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1468 ND_PRINTK(2, warn, 1469 "Redirect: target address is not link-local unicast\n"); 1470 return; 1471 } 1472 1473 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT, 1474 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex); 1475 1476 dst = ip6_route_output(net, NULL, &fl6); 1477 if (dst->error) { 1478 dst_release(dst); 1479 return; 1480 } 1481 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); 1482 if (IS_ERR(dst)) 1483 return; 1484 1485 rt = (struct rt6_info *) dst; 1486 1487 if (rt->rt6i_flags & RTF_GATEWAY) { 1488 ND_PRINTK(2, warn, 1489 "Redirect: destination is not a neighbour\n"); 1490 goto release; 1491 } 1492 peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1); 1493 ret = inet_peer_xrlim_allow(peer, 1*HZ); 1494 if (peer) 1495 inet_putpeer(peer); 1496 if (!ret) 1497 goto release; 1498 1499 if (dev->addr_len) { 1500 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target); 1501 if (!neigh) { 1502 ND_PRINTK(2, warn, 1503 "Redirect: no neigh for target address\n"); 1504 goto release; 1505 } 1506 1507 read_lock_bh(&neigh->lock); 1508 if (neigh->nud_state & NUD_VALID) { 1509 memcpy(ha_buf, neigh->ha, dev->addr_len); 1510 read_unlock_bh(&neigh->lock); 1511 ha = ha_buf; 1512 optlen += ndisc_opt_addr_space(dev); 1513 } else 1514 read_unlock_bh(&neigh->lock); 1515 1516 neigh_release(neigh); 1517 } 1518 1519 rd_len = min_t(unsigned int, 1520 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen, 1521 skb->len + 8); 1522 rd_len &= ~0x7; 1523 optlen += rd_len; 1524 1525 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 1526 if (!buff) 1527 goto release; 1528 1529 msg = (struct rd_msg *)skb_put(buff, sizeof(*msg)); 1530 *msg = (struct rd_msg) { 1531 .icmph = { 1532 .icmp6_type = NDISC_REDIRECT, 1533 }, 1534 .target = *target, 1535 .dest = ipv6_hdr(skb)->daddr, 1536 }; 1537 1538 /* 1539 * include target_address option 1540 */ 1541 1542 if (ha) 1543 ndisc_fill_addr_option(buff, ND_OPT_TARGET_LL_ADDR, ha); 1544 1545 /* 1546 * build redirect option and copy skb over to the new packet. 1547 */ 1548 1549 if (rd_len) 1550 ndisc_fill_redirect_hdr_option(buff, skb, rd_len); 1551 1552 skb_dst_set(buff, dst); 1553 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf); 1554 return; 1555 1556 release: 1557 dst_release(dst); 1558 } 1559 1560 static void pndisc_redo(struct sk_buff *skb) 1561 { 1562 ndisc_recv_ns(skb); 1563 kfree_skb(skb); 1564 } 1565 1566 static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb) 1567 { 1568 struct inet6_dev *idev = __in6_dev_get(skb->dev); 1569 1570 if (!idev) 1571 return true; 1572 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED && 1573 idev->cnf.suppress_frag_ndisc) { 1574 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n"); 1575 return true; 1576 } 1577 return false; 1578 } 1579 1580 int ndisc_rcv(struct sk_buff *skb) 1581 { 1582 struct nd_msg *msg; 1583 1584 if (ndisc_suppress_frag_ndisc(skb)) 1585 return 0; 1586 1587 if (skb_linearize(skb)) 1588 return 0; 1589 1590 msg = (struct nd_msg *)skb_transport_header(skb); 1591 1592 __skb_push(skb, skb->data - skb_transport_header(skb)); 1593 1594 if (ipv6_hdr(skb)->hop_limit != 255) { 1595 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n", 1596 ipv6_hdr(skb)->hop_limit); 1597 return 0; 1598 } 1599 1600 if (msg->icmph.icmp6_code != 0) { 1601 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n", 1602 msg->icmph.icmp6_code); 1603 return 0; 1604 } 1605 1606 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 1607 1608 switch (msg->icmph.icmp6_type) { 1609 case NDISC_NEIGHBOUR_SOLICITATION: 1610 ndisc_recv_ns(skb); 1611 break; 1612 1613 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1614 ndisc_recv_na(skb); 1615 break; 1616 1617 case NDISC_ROUTER_SOLICITATION: 1618 ndisc_recv_rs(skb); 1619 break; 1620 1621 case NDISC_ROUTER_ADVERTISEMENT: 1622 ndisc_router_discovery(skb); 1623 break; 1624 1625 case NDISC_REDIRECT: 1626 ndisc_redirect_rcv(skb); 1627 break; 1628 } 1629 1630 return 0; 1631 } 1632 1633 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1634 { 1635 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1636 struct net *net = dev_net(dev); 1637 struct inet6_dev *idev; 1638 1639 switch (event) { 1640 case NETDEV_CHANGEADDR: 1641 neigh_changeaddr(&nd_tbl, dev); 1642 fib6_run_gc(0, net, false); 1643 idev = in6_dev_get(dev); 1644 if (!idev) 1645 break; 1646 if (idev->cnf.ndisc_notify) 1647 ndisc_send_unsol_na(dev); 1648 in6_dev_put(idev); 1649 break; 1650 case NETDEV_DOWN: 1651 neigh_ifdown(&nd_tbl, dev); 1652 fib6_run_gc(0, net, false); 1653 break; 1654 case NETDEV_NOTIFY_PEERS: 1655 ndisc_send_unsol_na(dev); 1656 break; 1657 default: 1658 break; 1659 } 1660 1661 return NOTIFY_DONE; 1662 } 1663 1664 static struct notifier_block ndisc_netdev_notifier = { 1665 .notifier_call = ndisc_netdev_event, 1666 }; 1667 1668 #ifdef CONFIG_SYSCTL 1669 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl, 1670 const char *func, const char *dev_name) 1671 { 1672 static char warncomm[TASK_COMM_LEN]; 1673 static int warned; 1674 if (strcmp(warncomm, current->comm) && warned < 5) { 1675 strcpy(warncomm, current->comm); 1676 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n", 1677 warncomm, func, 1678 dev_name, ctl->procname, 1679 dev_name, ctl->procname); 1680 warned++; 1681 } 1682 } 1683 1684 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos) 1685 { 1686 struct net_device *dev = ctl->extra1; 1687 struct inet6_dev *idev; 1688 int ret; 1689 1690 if ((strcmp(ctl->procname, "retrans_time") == 0) || 1691 (strcmp(ctl->procname, "base_reachable_time") == 0)) 1692 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default"); 1693 1694 if (strcmp(ctl->procname, "retrans_time") == 0) 1695 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos); 1696 1697 else if (strcmp(ctl->procname, "base_reachable_time") == 0) 1698 ret = neigh_proc_dointvec_jiffies(ctl, write, 1699 buffer, lenp, ppos); 1700 1701 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) || 1702 (strcmp(ctl->procname, "base_reachable_time_ms") == 0)) 1703 ret = neigh_proc_dointvec_ms_jiffies(ctl, write, 1704 buffer, lenp, ppos); 1705 else 1706 ret = -1; 1707 1708 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) { 1709 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)) 1710 idev->nd_parms->reachable_time = 1711 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)); 1712 idev->tstamp = jiffies; 1713 inet6_ifinfo_notify(RTM_NEWLINK, idev); 1714 in6_dev_put(idev); 1715 } 1716 return ret; 1717 } 1718 1719 1720 #endif 1721 1722 static int __net_init ndisc_net_init(struct net *net) 1723 { 1724 struct ipv6_pinfo *np; 1725 struct sock *sk; 1726 int err; 1727 1728 err = inet_ctl_sock_create(&sk, PF_INET6, 1729 SOCK_RAW, IPPROTO_ICMPV6, net); 1730 if (err < 0) { 1731 ND_PRINTK(0, err, 1732 "NDISC: Failed to initialize the control socket (err %d)\n", 1733 err); 1734 return err; 1735 } 1736 1737 net->ipv6.ndisc_sk = sk; 1738 1739 np = inet6_sk(sk); 1740 np->hop_limit = 255; 1741 /* Do not loopback ndisc messages */ 1742 np->mc_loop = 0; 1743 1744 return 0; 1745 } 1746 1747 static void __net_exit ndisc_net_exit(struct net *net) 1748 { 1749 inet_ctl_sock_destroy(net->ipv6.ndisc_sk); 1750 } 1751 1752 static struct pernet_operations ndisc_net_ops = { 1753 .init = ndisc_net_init, 1754 .exit = ndisc_net_exit, 1755 }; 1756 1757 int __init ndisc_init(void) 1758 { 1759 int err; 1760 1761 err = register_pernet_subsys(&ndisc_net_ops); 1762 if (err) 1763 return err; 1764 /* 1765 * Initialize the neighbour table 1766 */ 1767 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl); 1768 1769 #ifdef CONFIG_SYSCTL 1770 err = neigh_sysctl_register(NULL, &nd_tbl.parms, 1771 ndisc_ifinfo_sysctl_change); 1772 if (err) 1773 goto out_unregister_pernet; 1774 out: 1775 #endif 1776 return err; 1777 1778 #ifdef CONFIG_SYSCTL 1779 out_unregister_pernet: 1780 unregister_pernet_subsys(&ndisc_net_ops); 1781 goto out; 1782 #endif 1783 } 1784 1785 int __init ndisc_late_init(void) 1786 { 1787 return register_netdevice_notifier(&ndisc_netdev_notifier); 1788 } 1789 1790 void ndisc_late_cleanup(void) 1791 { 1792 unregister_netdevice_notifier(&ndisc_netdev_notifier); 1793 } 1794 1795 void ndisc_cleanup(void) 1796 { 1797 #ifdef CONFIG_SYSCTL 1798 neigh_sysctl_unregister(&nd_tbl.parms); 1799 #endif 1800 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl); 1801 unregister_pernet_subsys(&ndisc_net_ops); 1802 } 1803