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_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr, 659 dev, 1, 660 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) 661 saddr = &ipv6_hdr(skb)->saddr; 662 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES); 663 if (probes < 0) { 664 if (!(neigh->nud_state & NUD_VALID)) { 665 ND_PRINTK(1, dbg, 666 "%s: trying to ucast probe in NUD_INVALID: %pI6\n", 667 __func__, target); 668 } 669 ndisc_send_ns(dev, neigh, target, target, saddr); 670 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) { 671 neigh_app_ns(neigh); 672 } else { 673 addrconf_addr_solict_mult(target, &mcaddr); 674 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr); 675 } 676 } 677 678 static int pndisc_is_router(const void *pkey, 679 struct net_device *dev) 680 { 681 struct pneigh_entry *n; 682 int ret = -1; 683 684 read_lock_bh(&nd_tbl.lock); 685 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev); 686 if (n) 687 ret = !!(n->flags & NTF_ROUTER); 688 read_unlock_bh(&nd_tbl.lock); 689 690 return ret; 691 } 692 693 static void ndisc_recv_ns(struct sk_buff *skb) 694 { 695 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 696 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 697 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 698 u8 *lladdr = NULL; 699 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 700 offsetof(struct nd_msg, opt)); 701 struct ndisc_options ndopts; 702 struct net_device *dev = skb->dev; 703 struct inet6_ifaddr *ifp; 704 struct inet6_dev *idev = NULL; 705 struct neighbour *neigh; 706 int dad = ipv6_addr_any(saddr); 707 bool inc; 708 int is_router = -1; 709 710 if (skb->len < sizeof(struct nd_msg)) { 711 ND_PRINTK(2, warn, "NS: packet too short\n"); 712 return; 713 } 714 715 if (ipv6_addr_is_multicast(&msg->target)) { 716 ND_PRINTK(2, warn, "NS: multicast target address\n"); 717 return; 718 } 719 720 /* 721 * RFC2461 7.1.1: 722 * DAD has to be destined for solicited node multicast address. 723 */ 724 if (dad && !ipv6_addr_is_solict_mult(daddr)) { 725 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n"); 726 return; 727 } 728 729 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { 730 ND_PRINTK(2, warn, "NS: invalid ND options\n"); 731 return; 732 } 733 734 if (ndopts.nd_opts_src_lladdr) { 735 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev); 736 if (!lladdr) { 737 ND_PRINTK(2, warn, 738 "NS: invalid link-layer address length\n"); 739 return; 740 } 741 742 /* RFC2461 7.1.1: 743 * If the IP source address is the unspecified address, 744 * there MUST NOT be source link-layer address option 745 * in the message. 746 */ 747 if (dad) { 748 ND_PRINTK(2, warn, 749 "NS: bad DAD packet (link-layer address option)\n"); 750 return; 751 } 752 } 753 754 inc = ipv6_addr_is_multicast(daddr); 755 756 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); 757 if (ifp) { 758 759 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) { 760 if (dad) { 761 /* 762 * We are colliding with another node 763 * who is doing DAD 764 * so fail our DAD process 765 */ 766 addrconf_dad_failure(ifp); 767 return; 768 } else { 769 /* 770 * This is not a dad solicitation. 771 * If we are an optimistic node, 772 * we should respond. 773 * Otherwise, we should ignore it. 774 */ 775 if (!(ifp->flags & IFA_F_OPTIMISTIC)) 776 goto out; 777 } 778 } 779 780 idev = ifp->idev; 781 } else { 782 struct net *net = dev_net(dev); 783 784 idev = in6_dev_get(dev); 785 if (!idev) { 786 /* XXX: count this drop? */ 787 return; 788 } 789 790 if (ipv6_chk_acast_addr(net, dev, &msg->target) || 791 (idev->cnf.forwarding && 792 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) && 793 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) { 794 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) && 795 skb->pkt_type != PACKET_HOST && 796 inc && 797 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) { 798 /* 799 * for anycast or proxy, 800 * sender should delay its response 801 * by a random time between 0 and 802 * MAX_ANYCAST_DELAY_TIME seconds. 803 * (RFC2461) -- yoshfuji 804 */ 805 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC); 806 if (n) 807 pneigh_enqueue(&nd_tbl, idev->nd_parms, n); 808 goto out; 809 } 810 } else 811 goto out; 812 } 813 814 if (is_router < 0) 815 is_router = idev->cnf.forwarding; 816 817 if (dad) { 818 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target, 819 !!is_router, false, (ifp != NULL), true); 820 goto out; 821 } 822 823 if (inc) 824 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast); 825 else 826 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast); 827 828 /* 829 * update / create cache entry 830 * for the source address 831 */ 832 neigh = __neigh_lookup(&nd_tbl, saddr, dev, 833 !inc || lladdr || !dev->addr_len); 834 if (neigh) 835 neigh_update(neigh, lladdr, NUD_STALE, 836 NEIGH_UPDATE_F_WEAK_OVERRIDE| 837 NEIGH_UPDATE_F_OVERRIDE); 838 if (neigh || !dev->header_ops) { 839 ndisc_send_na(dev, neigh, saddr, &msg->target, 840 !!is_router, 841 true, (ifp != NULL && inc), inc); 842 if (neigh) 843 neigh_release(neigh); 844 } 845 846 out: 847 if (ifp) 848 in6_ifa_put(ifp); 849 else 850 in6_dev_put(idev); 851 } 852 853 static void ndisc_recv_na(struct sk_buff *skb) 854 { 855 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 856 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 857 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 858 u8 *lladdr = NULL; 859 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 860 offsetof(struct nd_msg, opt)); 861 struct ndisc_options ndopts; 862 struct net_device *dev = skb->dev; 863 struct inet6_ifaddr *ifp; 864 struct neighbour *neigh; 865 866 if (skb->len < sizeof(struct nd_msg)) { 867 ND_PRINTK(2, warn, "NA: packet too short\n"); 868 return; 869 } 870 871 if (ipv6_addr_is_multicast(&msg->target)) { 872 ND_PRINTK(2, warn, "NA: target address is multicast\n"); 873 return; 874 } 875 876 if (ipv6_addr_is_multicast(daddr) && 877 msg->icmph.icmp6_solicited) { 878 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n"); 879 return; 880 } 881 882 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { 883 ND_PRINTK(2, warn, "NS: invalid ND option\n"); 884 return; 885 } 886 if (ndopts.nd_opts_tgt_lladdr) { 887 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev); 888 if (!lladdr) { 889 ND_PRINTK(2, warn, 890 "NA: invalid link-layer address length\n"); 891 return; 892 } 893 } 894 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); 895 if (ifp) { 896 if (skb->pkt_type != PACKET_LOOPBACK 897 && (ifp->flags & IFA_F_TENTATIVE)) { 898 addrconf_dad_failure(ifp); 899 return; 900 } 901 /* What should we make now? The advertisement 902 is invalid, but ndisc specs say nothing 903 about it. It could be misconfiguration, or 904 an smart proxy agent tries to help us :-) 905 906 We should not print the error if NA has been 907 received from loopback - it is just our own 908 unsolicited advertisement. 909 */ 910 if (skb->pkt_type != PACKET_LOOPBACK) 911 ND_PRINTK(1, warn, 912 "NA: someone advertises our address %pI6 on %s!\n", 913 &ifp->addr, ifp->idev->dev->name); 914 in6_ifa_put(ifp); 915 return; 916 } 917 neigh = neigh_lookup(&nd_tbl, &msg->target, dev); 918 919 if (neigh) { 920 u8 old_flags = neigh->flags; 921 struct net *net = dev_net(dev); 922 923 if (neigh->nud_state & NUD_FAILED) 924 goto out; 925 926 /* 927 * Don't update the neighbor cache entry on a proxy NA from 928 * ourselves because either the proxied node is off link or it 929 * has already sent a NA to us. 930 */ 931 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) && 932 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp && 933 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) { 934 /* XXX: idev->cnf.proxy_ndp */ 935 goto out; 936 } 937 938 neigh_update(neigh, lladdr, 939 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE, 940 NEIGH_UPDATE_F_WEAK_OVERRIDE| 941 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)| 942 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 943 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0)); 944 945 if ((old_flags & ~neigh->flags) & NTF_ROUTER) { 946 /* 947 * Change: router to host 948 */ 949 rt6_clean_tohost(dev_net(dev), saddr); 950 } 951 952 out: 953 neigh_release(neigh); 954 } 955 } 956 957 static void ndisc_recv_rs(struct sk_buff *skb) 958 { 959 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb); 960 unsigned long ndoptlen = skb->len - sizeof(*rs_msg); 961 struct neighbour *neigh; 962 struct inet6_dev *idev; 963 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 964 struct ndisc_options ndopts; 965 u8 *lladdr = NULL; 966 967 if (skb->len < sizeof(*rs_msg)) 968 return; 969 970 idev = __in6_dev_get(skb->dev); 971 if (!idev) { 972 ND_PRINTK(1, err, "RS: can't find in6 device\n"); 973 return; 974 } 975 976 /* Don't accept RS if we're not in router mode */ 977 if (!idev->cnf.forwarding) 978 goto out; 979 980 /* 981 * Don't update NCE if src = ::; 982 * this implies that the source node has no ip address assigned yet. 983 */ 984 if (ipv6_addr_any(saddr)) 985 goto out; 986 987 /* Parse ND options */ 988 if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) { 989 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n"); 990 goto out; 991 } 992 993 if (ndopts.nd_opts_src_lladdr) { 994 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 995 skb->dev); 996 if (!lladdr) 997 goto out; 998 } 999 1000 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1); 1001 if (neigh) { 1002 neigh_update(neigh, lladdr, NUD_STALE, 1003 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1004 NEIGH_UPDATE_F_OVERRIDE| 1005 NEIGH_UPDATE_F_OVERRIDE_ISROUTER); 1006 neigh_release(neigh); 1007 } 1008 out: 1009 return; 1010 } 1011 1012 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt) 1013 { 1014 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra); 1015 struct sk_buff *skb; 1016 struct nlmsghdr *nlh; 1017 struct nduseroptmsg *ndmsg; 1018 struct net *net = dev_net(ra->dev); 1019 int err; 1020 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg) 1021 + (opt->nd_opt_len << 3)); 1022 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr)); 1023 1024 skb = nlmsg_new(msg_size, GFP_ATOMIC); 1025 if (skb == NULL) { 1026 err = -ENOBUFS; 1027 goto errout; 1028 } 1029 1030 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0); 1031 if (nlh == NULL) { 1032 goto nla_put_failure; 1033 } 1034 1035 ndmsg = nlmsg_data(nlh); 1036 ndmsg->nduseropt_family = AF_INET6; 1037 ndmsg->nduseropt_ifindex = ra->dev->ifindex; 1038 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type; 1039 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code; 1040 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3; 1041 1042 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3); 1043 1044 if (nla_put(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr), 1045 &ipv6_hdr(ra)->saddr)) 1046 goto nla_put_failure; 1047 nlmsg_end(skb, nlh); 1048 1049 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC); 1050 return; 1051 1052 nla_put_failure: 1053 nlmsg_free(skb); 1054 err = -EMSGSIZE; 1055 errout: 1056 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err); 1057 } 1058 1059 static void ndisc_router_discovery(struct sk_buff *skb) 1060 { 1061 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb); 1062 struct neighbour *neigh = NULL; 1063 struct inet6_dev *in6_dev; 1064 struct rt6_info *rt = NULL; 1065 int lifetime; 1066 struct ndisc_options ndopts; 1067 int optlen; 1068 unsigned int pref = 0; 1069 1070 __u8 *opt = (__u8 *)(ra_msg + 1); 1071 1072 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) - 1073 sizeof(struct ra_msg); 1074 1075 ND_PRINTK(2, info, 1076 "RA: %s, dev: %s\n", 1077 __func__, skb->dev->name); 1078 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1079 ND_PRINTK(2, warn, "RA: source address is not link-local\n"); 1080 return; 1081 } 1082 if (optlen < 0) { 1083 ND_PRINTK(2, warn, "RA: packet too short\n"); 1084 return; 1085 } 1086 1087 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1088 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) { 1089 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n"); 1090 return; 1091 } 1092 #endif 1093 1094 /* 1095 * set the RA_RECV flag in the interface 1096 */ 1097 1098 in6_dev = __in6_dev_get(skb->dev); 1099 if (in6_dev == NULL) { 1100 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n", 1101 skb->dev->name); 1102 return; 1103 } 1104 1105 if (!ndisc_parse_options(opt, optlen, &ndopts)) { 1106 ND_PRINTK(2, warn, "RA: invalid ND options\n"); 1107 return; 1108 } 1109 1110 if (!ipv6_accept_ra(in6_dev)) { 1111 ND_PRINTK(2, info, 1112 "RA: %s, did not accept ra for dev: %s\n", 1113 __func__, skb->dev->name); 1114 goto skip_linkparms; 1115 } 1116 1117 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1118 /* skip link-specific parameters from interior routers */ 1119 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1120 ND_PRINTK(2, info, 1121 "RA: %s, nodetype is NODEFAULT, dev: %s\n", 1122 __func__, skb->dev->name); 1123 goto skip_linkparms; 1124 } 1125 #endif 1126 1127 if (in6_dev->if_flags & IF_RS_SENT) { 1128 /* 1129 * flag that an RA was received after an RS was sent 1130 * out on this interface. 1131 */ 1132 in6_dev->if_flags |= IF_RA_RCVD; 1133 } 1134 1135 /* 1136 * Remember the managed/otherconf flags from most recently 1137 * received RA message (RFC 2462) -- yoshfuji 1138 */ 1139 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED | 1140 IF_RA_OTHERCONF)) | 1141 (ra_msg->icmph.icmp6_addrconf_managed ? 1142 IF_RA_MANAGED : 0) | 1143 (ra_msg->icmph.icmp6_addrconf_other ? 1144 IF_RA_OTHERCONF : 0); 1145 1146 if (!in6_dev->cnf.accept_ra_defrtr) { 1147 ND_PRINTK(2, info, 1148 "RA: %s, defrtr is false for dev: %s\n", 1149 __func__, skb->dev->name); 1150 goto skip_defrtr; 1151 } 1152 1153 /* Do not accept RA with source-addr found on local machine unless 1154 * accept_ra_from_local is set to true. 1155 */ 1156 if (!in6_dev->cnf.accept_ra_from_local && 1157 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, 1158 NULL, 0)) { 1159 ND_PRINTK(2, info, 1160 "RA from local address detected on dev: %s: default router ignored\n", 1161 skb->dev->name); 1162 goto skip_defrtr; 1163 } 1164 1165 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); 1166 1167 #ifdef CONFIG_IPV6_ROUTER_PREF 1168 pref = ra_msg->icmph.icmp6_router_pref; 1169 /* 10b is handled as if it were 00b (medium) */ 1170 if (pref == ICMPV6_ROUTER_PREF_INVALID || 1171 !in6_dev->cnf.accept_ra_rtr_pref) 1172 pref = ICMPV6_ROUTER_PREF_MEDIUM; 1173 #endif 1174 1175 rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev); 1176 1177 if (rt) { 1178 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr); 1179 if (!neigh) { 1180 ND_PRINTK(0, err, 1181 "RA: %s got default router without neighbour\n", 1182 __func__); 1183 ip6_rt_put(rt); 1184 return; 1185 } 1186 } 1187 if (rt && lifetime == 0) { 1188 ip6_del_rt(rt); 1189 rt = NULL; 1190 } 1191 1192 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, for dev: %s\n", 1193 rt, lifetime, skb->dev->name); 1194 if (rt == NULL && lifetime) { 1195 ND_PRINTK(3, info, "RA: adding default router\n"); 1196 1197 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref); 1198 if (rt == NULL) { 1199 ND_PRINTK(0, err, 1200 "RA: %s failed to add default route\n", 1201 __func__); 1202 return; 1203 } 1204 1205 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr); 1206 if (neigh == NULL) { 1207 ND_PRINTK(0, err, 1208 "RA: %s got default router without neighbour\n", 1209 __func__); 1210 ip6_rt_put(rt); 1211 return; 1212 } 1213 neigh->flags |= NTF_ROUTER; 1214 } else if (rt) { 1215 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 1216 } 1217 1218 if (rt) 1219 rt6_set_expires(rt, jiffies + (HZ * lifetime)); 1220 if (ra_msg->icmph.icmp6_hop_limit) { 1221 /* Only set hop_limit on the interface if it is higher than 1222 * the current hop_limit. 1223 */ 1224 if (in6_dev->cnf.hop_limit < ra_msg->icmph.icmp6_hop_limit) { 1225 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit; 1226 } else { 1227 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than current\n"); 1228 } 1229 if (rt) 1230 dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 1231 ra_msg->icmph.icmp6_hop_limit); 1232 } 1233 1234 skip_defrtr: 1235 1236 /* 1237 * Update Reachable Time and Retrans Timer 1238 */ 1239 1240 if (in6_dev->nd_parms) { 1241 unsigned long rtime = ntohl(ra_msg->retrans_timer); 1242 1243 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) { 1244 rtime = (rtime*HZ)/1000; 1245 if (rtime < HZ/10) 1246 rtime = HZ/10; 1247 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime); 1248 in6_dev->tstamp = jiffies; 1249 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1250 } 1251 1252 rtime = ntohl(ra_msg->reachable_time); 1253 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) { 1254 rtime = (rtime*HZ)/1000; 1255 1256 if (rtime < HZ/10) 1257 rtime = HZ/10; 1258 1259 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) { 1260 NEIGH_VAR_SET(in6_dev->nd_parms, 1261 BASE_REACHABLE_TIME, rtime); 1262 NEIGH_VAR_SET(in6_dev->nd_parms, 1263 GC_STALETIME, 3 * rtime); 1264 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime); 1265 in6_dev->tstamp = jiffies; 1266 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1267 } 1268 } 1269 } 1270 1271 skip_linkparms: 1272 1273 /* 1274 * Process options. 1275 */ 1276 1277 if (!neigh) 1278 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr, 1279 skb->dev, 1); 1280 if (neigh) { 1281 u8 *lladdr = NULL; 1282 if (ndopts.nd_opts_src_lladdr) { 1283 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1284 skb->dev); 1285 if (!lladdr) { 1286 ND_PRINTK(2, warn, 1287 "RA: invalid link-layer address length\n"); 1288 goto out; 1289 } 1290 } 1291 neigh_update(neigh, lladdr, NUD_STALE, 1292 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1293 NEIGH_UPDATE_F_OVERRIDE| 1294 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1295 NEIGH_UPDATE_F_ISROUTER); 1296 } 1297 1298 if (!ipv6_accept_ra(in6_dev)) { 1299 ND_PRINTK(2, info, 1300 "RA: %s, accept_ra is false for dev: %s\n", 1301 __func__, skb->dev->name); 1302 goto out; 1303 } 1304 1305 #ifdef CONFIG_IPV6_ROUTE_INFO 1306 if (!in6_dev->cnf.accept_ra_from_local && 1307 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, 1308 NULL, 0)) { 1309 ND_PRINTK(2, info, 1310 "RA from local address detected on dev: %s: router info ignored.\n", 1311 skb->dev->name); 1312 goto skip_routeinfo; 1313 } 1314 1315 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) { 1316 struct nd_opt_hdr *p; 1317 for (p = ndopts.nd_opts_ri; 1318 p; 1319 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) { 1320 struct route_info *ri = (struct route_info *)p; 1321 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1322 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT && 1323 ri->prefix_len == 0) 1324 continue; 1325 #endif 1326 if (ri->prefix_len == 0 && 1327 !in6_dev->cnf.accept_ra_defrtr) 1328 continue; 1329 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen) 1330 continue; 1331 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3, 1332 &ipv6_hdr(skb)->saddr); 1333 } 1334 } 1335 1336 skip_routeinfo: 1337 #endif 1338 1339 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1340 /* skip link-specific ndopts from interior routers */ 1341 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1342 ND_PRINTK(2, info, 1343 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n", 1344 __func__, skb->dev->name); 1345 goto out; 1346 } 1347 #endif 1348 1349 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) { 1350 struct nd_opt_hdr *p; 1351 for (p = ndopts.nd_opts_pi; 1352 p; 1353 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) { 1354 addrconf_prefix_rcv(skb->dev, (u8 *)p, 1355 (p->nd_opt_len) << 3, 1356 ndopts.nd_opts_src_lladdr != NULL); 1357 } 1358 } 1359 1360 if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) { 1361 __be32 n; 1362 u32 mtu; 1363 1364 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); 1365 mtu = ntohl(n); 1366 1367 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { 1368 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu); 1369 } else if (in6_dev->cnf.mtu6 != mtu) { 1370 in6_dev->cnf.mtu6 = mtu; 1371 1372 if (rt) 1373 dst_metric_set(&rt->dst, RTAX_MTU, mtu); 1374 1375 rt6_mtu_change(skb->dev, mtu); 1376 } 1377 } 1378 1379 if (ndopts.nd_useropts) { 1380 struct nd_opt_hdr *p; 1381 for (p = ndopts.nd_useropts; 1382 p; 1383 p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) { 1384 ndisc_ra_useropt(skb, p); 1385 } 1386 } 1387 1388 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { 1389 ND_PRINTK(2, warn, "RA: invalid RA options\n"); 1390 } 1391 out: 1392 ip6_rt_put(rt); 1393 if (neigh) 1394 neigh_release(neigh); 1395 } 1396 1397 static void ndisc_redirect_rcv(struct sk_buff *skb) 1398 { 1399 u8 *hdr; 1400 struct ndisc_options ndopts; 1401 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb); 1402 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 1403 offsetof(struct rd_msg, opt)); 1404 1405 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1406 switch (skb->ndisc_nodetype) { 1407 case NDISC_NODETYPE_HOST: 1408 case NDISC_NODETYPE_NODEFAULT: 1409 ND_PRINTK(2, warn, 1410 "Redirect: from host or unauthorized router\n"); 1411 return; 1412 } 1413 #endif 1414 1415 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1416 ND_PRINTK(2, warn, 1417 "Redirect: source address is not link-local\n"); 1418 return; 1419 } 1420 1421 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) 1422 return; 1423 1424 if (!ndopts.nd_opts_rh) { 1425 ip6_redirect_no_header(skb, dev_net(skb->dev), 1426 skb->dev->ifindex, 0); 1427 return; 1428 } 1429 1430 hdr = (u8 *)ndopts.nd_opts_rh; 1431 hdr += 8; 1432 if (!pskb_pull(skb, hdr - skb_transport_header(skb))) 1433 return; 1434 1435 icmpv6_notify(skb, NDISC_REDIRECT, 0, 0); 1436 } 1437 1438 static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb, 1439 struct sk_buff *orig_skb, 1440 int rd_len) 1441 { 1442 u8 *opt = skb_put(skb, rd_len); 1443 1444 memset(opt, 0, 8); 1445 *(opt++) = ND_OPT_REDIRECT_HDR; 1446 *(opt++) = (rd_len >> 3); 1447 opt += 6; 1448 1449 memcpy(opt, ipv6_hdr(orig_skb), rd_len - 8); 1450 } 1451 1452 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target) 1453 { 1454 struct net_device *dev = skb->dev; 1455 struct net *net = dev_net(dev); 1456 struct sock *sk = net->ipv6.ndisc_sk; 1457 int optlen = 0; 1458 struct inet_peer *peer; 1459 struct sk_buff *buff; 1460 struct rd_msg *msg; 1461 struct in6_addr saddr_buf; 1462 struct rt6_info *rt; 1463 struct dst_entry *dst; 1464 struct flowi6 fl6; 1465 int rd_len; 1466 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL; 1467 bool ret; 1468 1469 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) { 1470 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n", 1471 dev->name); 1472 return; 1473 } 1474 1475 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) && 1476 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1477 ND_PRINTK(2, warn, 1478 "Redirect: target address is not link-local unicast\n"); 1479 return; 1480 } 1481 1482 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT, 1483 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex); 1484 1485 dst = ip6_route_output(net, NULL, &fl6); 1486 if (dst->error) { 1487 dst_release(dst); 1488 return; 1489 } 1490 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); 1491 if (IS_ERR(dst)) 1492 return; 1493 1494 rt = (struct rt6_info *) dst; 1495 1496 if (rt->rt6i_flags & RTF_GATEWAY) { 1497 ND_PRINTK(2, warn, 1498 "Redirect: destination is not a neighbour\n"); 1499 goto release; 1500 } 1501 peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1); 1502 ret = inet_peer_xrlim_allow(peer, 1*HZ); 1503 if (peer) 1504 inet_putpeer(peer); 1505 if (!ret) 1506 goto release; 1507 1508 if (dev->addr_len) { 1509 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target); 1510 if (!neigh) { 1511 ND_PRINTK(2, warn, 1512 "Redirect: no neigh for target address\n"); 1513 goto release; 1514 } 1515 1516 read_lock_bh(&neigh->lock); 1517 if (neigh->nud_state & NUD_VALID) { 1518 memcpy(ha_buf, neigh->ha, dev->addr_len); 1519 read_unlock_bh(&neigh->lock); 1520 ha = ha_buf; 1521 optlen += ndisc_opt_addr_space(dev); 1522 } else 1523 read_unlock_bh(&neigh->lock); 1524 1525 neigh_release(neigh); 1526 } 1527 1528 rd_len = min_t(unsigned int, 1529 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen, 1530 skb->len + 8); 1531 rd_len &= ~0x7; 1532 optlen += rd_len; 1533 1534 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 1535 if (!buff) 1536 goto release; 1537 1538 msg = (struct rd_msg *)skb_put(buff, sizeof(*msg)); 1539 *msg = (struct rd_msg) { 1540 .icmph = { 1541 .icmp6_type = NDISC_REDIRECT, 1542 }, 1543 .target = *target, 1544 .dest = ipv6_hdr(skb)->daddr, 1545 }; 1546 1547 /* 1548 * include target_address option 1549 */ 1550 1551 if (ha) 1552 ndisc_fill_addr_option(buff, ND_OPT_TARGET_LL_ADDR, ha); 1553 1554 /* 1555 * build redirect option and copy skb over to the new packet. 1556 */ 1557 1558 if (rd_len) 1559 ndisc_fill_redirect_hdr_option(buff, skb, rd_len); 1560 1561 skb_dst_set(buff, dst); 1562 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf); 1563 return; 1564 1565 release: 1566 dst_release(dst); 1567 } 1568 1569 static void pndisc_redo(struct sk_buff *skb) 1570 { 1571 ndisc_recv_ns(skb); 1572 kfree_skb(skb); 1573 } 1574 1575 static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb) 1576 { 1577 struct inet6_dev *idev = __in6_dev_get(skb->dev); 1578 1579 if (!idev) 1580 return true; 1581 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED && 1582 idev->cnf.suppress_frag_ndisc) { 1583 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n"); 1584 return true; 1585 } 1586 return false; 1587 } 1588 1589 int ndisc_rcv(struct sk_buff *skb) 1590 { 1591 struct nd_msg *msg; 1592 1593 if (ndisc_suppress_frag_ndisc(skb)) 1594 return 0; 1595 1596 if (skb_linearize(skb)) 1597 return 0; 1598 1599 msg = (struct nd_msg *)skb_transport_header(skb); 1600 1601 __skb_push(skb, skb->data - skb_transport_header(skb)); 1602 1603 if (ipv6_hdr(skb)->hop_limit != 255) { 1604 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n", 1605 ipv6_hdr(skb)->hop_limit); 1606 return 0; 1607 } 1608 1609 if (msg->icmph.icmp6_code != 0) { 1610 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n", 1611 msg->icmph.icmp6_code); 1612 return 0; 1613 } 1614 1615 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 1616 1617 switch (msg->icmph.icmp6_type) { 1618 case NDISC_NEIGHBOUR_SOLICITATION: 1619 ndisc_recv_ns(skb); 1620 break; 1621 1622 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1623 ndisc_recv_na(skb); 1624 break; 1625 1626 case NDISC_ROUTER_SOLICITATION: 1627 ndisc_recv_rs(skb); 1628 break; 1629 1630 case NDISC_ROUTER_ADVERTISEMENT: 1631 ndisc_router_discovery(skb); 1632 break; 1633 1634 case NDISC_REDIRECT: 1635 ndisc_redirect_rcv(skb); 1636 break; 1637 } 1638 1639 return 0; 1640 } 1641 1642 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1643 { 1644 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1645 struct net *net = dev_net(dev); 1646 struct inet6_dev *idev; 1647 1648 switch (event) { 1649 case NETDEV_CHANGEADDR: 1650 neigh_changeaddr(&nd_tbl, dev); 1651 fib6_run_gc(0, net, false); 1652 idev = in6_dev_get(dev); 1653 if (!idev) 1654 break; 1655 if (idev->cnf.ndisc_notify) 1656 ndisc_send_unsol_na(dev); 1657 in6_dev_put(idev); 1658 break; 1659 case NETDEV_DOWN: 1660 neigh_ifdown(&nd_tbl, dev); 1661 fib6_run_gc(0, net, false); 1662 break; 1663 case NETDEV_NOTIFY_PEERS: 1664 ndisc_send_unsol_na(dev); 1665 break; 1666 default: 1667 break; 1668 } 1669 1670 return NOTIFY_DONE; 1671 } 1672 1673 static struct notifier_block ndisc_netdev_notifier = { 1674 .notifier_call = ndisc_netdev_event, 1675 }; 1676 1677 #ifdef CONFIG_SYSCTL 1678 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl, 1679 const char *func, const char *dev_name) 1680 { 1681 static char warncomm[TASK_COMM_LEN]; 1682 static int warned; 1683 if (strcmp(warncomm, current->comm) && warned < 5) { 1684 strcpy(warncomm, current->comm); 1685 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n", 1686 warncomm, func, 1687 dev_name, ctl->procname, 1688 dev_name, ctl->procname); 1689 warned++; 1690 } 1691 } 1692 1693 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos) 1694 { 1695 struct net_device *dev = ctl->extra1; 1696 struct inet6_dev *idev; 1697 int ret; 1698 1699 if ((strcmp(ctl->procname, "retrans_time") == 0) || 1700 (strcmp(ctl->procname, "base_reachable_time") == 0)) 1701 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default"); 1702 1703 if (strcmp(ctl->procname, "retrans_time") == 0) 1704 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos); 1705 1706 else if (strcmp(ctl->procname, "base_reachable_time") == 0) 1707 ret = neigh_proc_dointvec_jiffies(ctl, write, 1708 buffer, lenp, ppos); 1709 1710 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) || 1711 (strcmp(ctl->procname, "base_reachable_time_ms") == 0)) 1712 ret = neigh_proc_dointvec_ms_jiffies(ctl, write, 1713 buffer, lenp, ppos); 1714 else 1715 ret = -1; 1716 1717 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) { 1718 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)) 1719 idev->nd_parms->reachable_time = 1720 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)); 1721 idev->tstamp = jiffies; 1722 inet6_ifinfo_notify(RTM_NEWLINK, idev); 1723 in6_dev_put(idev); 1724 } 1725 return ret; 1726 } 1727 1728 1729 #endif 1730 1731 static int __net_init ndisc_net_init(struct net *net) 1732 { 1733 struct ipv6_pinfo *np; 1734 struct sock *sk; 1735 int err; 1736 1737 err = inet_ctl_sock_create(&sk, PF_INET6, 1738 SOCK_RAW, IPPROTO_ICMPV6, net); 1739 if (err < 0) { 1740 ND_PRINTK(0, err, 1741 "NDISC: Failed to initialize the control socket (err %d)\n", 1742 err); 1743 return err; 1744 } 1745 1746 net->ipv6.ndisc_sk = sk; 1747 1748 np = inet6_sk(sk); 1749 np->hop_limit = 255; 1750 /* Do not loopback ndisc messages */ 1751 np->mc_loop = 0; 1752 1753 return 0; 1754 } 1755 1756 static void __net_exit ndisc_net_exit(struct net *net) 1757 { 1758 inet_ctl_sock_destroy(net->ipv6.ndisc_sk); 1759 } 1760 1761 static struct pernet_operations ndisc_net_ops = { 1762 .init = ndisc_net_init, 1763 .exit = ndisc_net_exit, 1764 }; 1765 1766 int __init ndisc_init(void) 1767 { 1768 int err; 1769 1770 err = register_pernet_subsys(&ndisc_net_ops); 1771 if (err) 1772 return err; 1773 /* 1774 * Initialize the neighbour table 1775 */ 1776 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl); 1777 1778 #ifdef CONFIG_SYSCTL 1779 err = neigh_sysctl_register(NULL, &nd_tbl.parms, 1780 ndisc_ifinfo_sysctl_change); 1781 if (err) 1782 goto out_unregister_pernet; 1783 out: 1784 #endif 1785 return err; 1786 1787 #ifdef CONFIG_SYSCTL 1788 out_unregister_pernet: 1789 unregister_pernet_subsys(&ndisc_net_ops); 1790 goto out; 1791 #endif 1792 } 1793 1794 int __init ndisc_late_init(void) 1795 { 1796 return register_netdevice_notifier(&ndisc_netdev_notifier); 1797 } 1798 1799 void ndisc_late_cleanup(void) 1800 { 1801 unregister_netdevice_notifier(&ndisc_netdev_notifier); 1802 } 1803 1804 void ndisc_cleanup(void) 1805 { 1806 #ifdef CONFIG_SYSCTL 1807 neigh_sysctl_unregister(&nd_tbl.parms); 1808 #endif 1809 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl); 1810 unregister_pernet_subsys(&ndisc_net_ops); 1811 } 1812