ndisc.c revision cb5b09c17fe60056bc8f127ffc987d361c40ed4b
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, ...) \ 79do { \ 80 if (val <= ND_DEBUG) \ 81 net_##level##_ratelimited(fmt, ##__VA_ARGS__); \ 82} while (0) 83 84static u32 ndisc_hash(const void *pkey, 85 const struct net_device *dev, 86 __u32 *hash_rnd); 87static int ndisc_constructor(struct neighbour *neigh); 88static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb); 89static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb); 90static int pndisc_constructor(struct pneigh_entry *n); 91static void pndisc_destructor(struct pneigh_entry *n); 92static void pndisc_redo(struct sk_buff *skb); 93 94static 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 102static 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 111static const struct neigh_ops ndisc_direct_ops = { 112 .family = AF_INET6, 113 .output = neigh_direct_output, 114 .connected_output = neigh_direct_output, 115}; 116 117struct 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 148static 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 if ((space -= data_len) > 0) 166 memset(opt, 0, space); 167} 168 169static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur, 170 struct nd_opt_hdr *end) 171{ 172 int type; 173 if (!cur || !end || cur >= end) 174 return NULL; 175 type = cur->nd_opt_type; 176 do { 177 cur = ((void *)cur) + (cur->nd_opt_len << 3); 178 } while(cur < end && cur->nd_opt_type != type); 179 return cur <= end && cur->nd_opt_type == type ? cur : NULL; 180} 181 182static inline int ndisc_is_useropt(struct nd_opt_hdr *opt) 183{ 184 return opt->nd_opt_type == ND_OPT_RDNSS || 185 opt->nd_opt_type == ND_OPT_DNSSL; 186} 187 188static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur, 189 struct nd_opt_hdr *end) 190{ 191 if (!cur || !end || cur >= end) 192 return NULL; 193 do { 194 cur = ((void *)cur) + (cur->nd_opt_len << 3); 195 } while(cur < end && !ndisc_is_useropt(cur)); 196 return cur <= end && ndisc_is_useropt(cur) ? cur : NULL; 197} 198 199struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len, 200 struct ndisc_options *ndopts) 201{ 202 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt; 203 204 if (!nd_opt || opt_len < 0 || !ndopts) 205 return NULL; 206 memset(ndopts, 0, sizeof(*ndopts)); 207 while (opt_len) { 208 int l; 209 if (opt_len < sizeof(struct nd_opt_hdr)) 210 return NULL; 211 l = nd_opt->nd_opt_len << 3; 212 if (opt_len < l || l == 0) 213 return NULL; 214 switch (nd_opt->nd_opt_type) { 215 case ND_OPT_SOURCE_LL_ADDR: 216 case ND_OPT_TARGET_LL_ADDR: 217 case ND_OPT_MTU: 218 case ND_OPT_REDIRECT_HDR: 219 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { 220 ND_PRINTK(2, warn, 221 "%s: duplicated ND6 option found: type=%d\n", 222 __func__, nd_opt->nd_opt_type); 223 } else { 224 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; 225 } 226 break; 227 case ND_OPT_PREFIX_INFO: 228 ndopts->nd_opts_pi_end = nd_opt; 229 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type]) 230 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; 231 break; 232#ifdef CONFIG_IPV6_ROUTE_INFO 233 case ND_OPT_ROUTE_INFO: 234 ndopts->nd_opts_ri_end = nd_opt; 235 if (!ndopts->nd_opts_ri) 236 ndopts->nd_opts_ri = nd_opt; 237 break; 238#endif 239 default: 240 if (ndisc_is_useropt(nd_opt)) { 241 ndopts->nd_useropts_end = nd_opt; 242 if (!ndopts->nd_useropts) 243 ndopts->nd_useropts = nd_opt; 244 } else { 245 /* 246 * Unknown options must be silently ignored, 247 * to accommodate future extension to the 248 * protocol. 249 */ 250 ND_PRINTK(2, notice, 251 "%s: ignored unsupported option; type=%d, len=%d\n", 252 __func__, 253 nd_opt->nd_opt_type, 254 nd_opt->nd_opt_len); 255 } 256 } 257 opt_len -= l; 258 nd_opt = ((void *)nd_opt) + l; 259 } 260 return ndopts; 261} 262 263int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir) 264{ 265 switch (dev->type) { 266 case ARPHRD_ETHER: 267 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */ 268 case ARPHRD_FDDI: 269 ipv6_eth_mc_map(addr, buf); 270 return 0; 271 case ARPHRD_ARCNET: 272 ipv6_arcnet_mc_map(addr, buf); 273 return 0; 274 case ARPHRD_INFINIBAND: 275 ipv6_ib_mc_map(addr, dev->broadcast, buf); 276 return 0; 277 case ARPHRD_IPGRE: 278 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf); 279 default: 280 if (dir) { 281 memcpy(buf, dev->broadcast, dev->addr_len); 282 return 0; 283 } 284 } 285 return -EINVAL; 286} 287 288EXPORT_SYMBOL(ndisc_mc_map); 289 290static 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 297static 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 345static 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 358static 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 370static 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 399static 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 420static 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 468void 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 524static 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 545void 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 586void 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 638static 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 650static 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; 660 661 if ((probes -= NEIGH_VAR(neigh->parms, UCAST_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 676static 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 691static 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 844out: 845 if (ifp) 846 in6_ifa_put(ifp); 847 else 848 in6_dev_put(idev); 849} 850 851static void ndisc_recv_na(struct sk_buff *skb) 852{ 853 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 854 const 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 struct rt6_info *rt; 948 rt = rt6_get_dflt_router(saddr, dev); 949 if (rt) 950 ip6_del_rt(rt); 951 } 952 953out: 954 neigh_release(neigh); 955 } 956} 957 958static void ndisc_recv_rs(struct sk_buff *skb) 959{ 960 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb); 961 unsigned long ndoptlen = skb->len - sizeof(*rs_msg); 962 struct neighbour *neigh; 963 struct inet6_dev *idev; 964 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 965 struct ndisc_options ndopts; 966 u8 *lladdr = NULL; 967 968 if (skb->len < sizeof(*rs_msg)) 969 return; 970 971 idev = __in6_dev_get(skb->dev); 972 if (!idev) { 973 ND_PRINTK(1, err, "RS: can't find in6 device\n"); 974 return; 975 } 976 977 /* Don't accept RS if we're not in router mode */ 978 if (!idev->cnf.forwarding) 979 goto out; 980 981 /* 982 * Don't update NCE if src = ::; 983 * this implies that the source node has no ip address assigned yet. 984 */ 985 if (ipv6_addr_any(saddr)) 986 goto out; 987 988 /* Parse ND options */ 989 if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) { 990 ND_PRINTK(2, notice, "NS: invalid ND option, ignored\n"); 991 goto out; 992 } 993 994 if (ndopts.nd_opts_src_lladdr) { 995 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 996 skb->dev); 997 if (!lladdr) 998 goto out; 999 } 1000 1001 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1); 1002 if (neigh) { 1003 neigh_update(neigh, lladdr, NUD_STALE, 1004 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1005 NEIGH_UPDATE_F_OVERRIDE| 1006 NEIGH_UPDATE_F_OVERRIDE_ISROUTER); 1007 neigh_release(neigh); 1008 } 1009out: 1010 return; 1011} 1012 1013static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt) 1014{ 1015 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra); 1016 struct sk_buff *skb; 1017 struct nlmsghdr *nlh; 1018 struct nduseroptmsg *ndmsg; 1019 struct net *net = dev_net(ra->dev); 1020 int err; 1021 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg) 1022 + (opt->nd_opt_len << 3)); 1023 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr)); 1024 1025 skb = nlmsg_new(msg_size, GFP_ATOMIC); 1026 if (skb == NULL) { 1027 err = -ENOBUFS; 1028 goto errout; 1029 } 1030 1031 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0); 1032 if (nlh == NULL) { 1033 goto nla_put_failure; 1034 } 1035 1036 ndmsg = nlmsg_data(nlh); 1037 ndmsg->nduseropt_family = AF_INET6; 1038 ndmsg->nduseropt_ifindex = ra->dev->ifindex; 1039 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type; 1040 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code; 1041 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3; 1042 1043 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3); 1044 1045 if (nla_put(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr), 1046 &ipv6_hdr(ra)->saddr)) 1047 goto nla_put_failure; 1048 nlmsg_end(skb, nlh); 1049 1050 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC); 1051 return; 1052 1053nla_put_failure: 1054 nlmsg_free(skb); 1055 err = -EMSGSIZE; 1056errout: 1057 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err); 1058} 1059 1060static void ndisc_router_discovery(struct sk_buff *skb) 1061{ 1062 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb); 1063 struct neighbour *neigh = NULL; 1064 struct inet6_dev *in6_dev; 1065 struct rt6_info *rt = NULL; 1066 int lifetime; 1067 struct ndisc_options ndopts; 1068 int optlen; 1069 unsigned int pref = 0; 1070 1071 __u8 * opt = (__u8 *)(ra_msg + 1); 1072 1073 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) - 1074 sizeof(struct ra_msg); 1075 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 goto skip_linkparms; 1110 1111#ifdef CONFIG_IPV6_NDISC_NODETYPE 1112 /* skip link-specific parameters from interior routers */ 1113 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) 1114 goto skip_linkparms; 1115#endif 1116 1117 if (in6_dev->if_flags & IF_RS_SENT) { 1118 /* 1119 * flag that an RA was received after an RS was sent 1120 * out on this interface. 1121 */ 1122 in6_dev->if_flags |= IF_RA_RCVD; 1123 } 1124 1125 /* 1126 * Remember the managed/otherconf flags from most recently 1127 * received RA message (RFC 2462) -- yoshfuji 1128 */ 1129 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED | 1130 IF_RA_OTHERCONF)) | 1131 (ra_msg->icmph.icmp6_addrconf_managed ? 1132 IF_RA_MANAGED : 0) | 1133 (ra_msg->icmph.icmp6_addrconf_other ? 1134 IF_RA_OTHERCONF : 0); 1135 1136 if (!in6_dev->cnf.accept_ra_defrtr) 1137 goto skip_defrtr; 1138 1139 if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0)) 1140 goto skip_defrtr; 1141 1142 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); 1143 1144#ifdef CONFIG_IPV6_ROUTER_PREF 1145 pref = ra_msg->icmph.icmp6_router_pref; 1146 /* 10b is handled as if it were 00b (medium) */ 1147 if (pref == ICMPV6_ROUTER_PREF_INVALID || 1148 !in6_dev->cnf.accept_ra_rtr_pref) 1149 pref = ICMPV6_ROUTER_PREF_MEDIUM; 1150#endif 1151 1152 rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev); 1153 1154 if (rt) { 1155 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr); 1156 if (!neigh) { 1157 ND_PRINTK(0, err, 1158 "RA: %s got default router without neighbour\n", 1159 __func__); 1160 ip6_rt_put(rt); 1161 return; 1162 } 1163 } 1164 if (rt && lifetime == 0) { 1165 ip6_del_rt(rt); 1166 rt = NULL; 1167 } 1168 1169 if (rt == NULL && lifetime) { 1170 ND_PRINTK(3, dbg, "RA: adding default router\n"); 1171 1172 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref); 1173 if (rt == NULL) { 1174 ND_PRINTK(0, err, 1175 "RA: %s failed to add default route\n", 1176 __func__); 1177 return; 1178 } 1179 1180 neigh = dst_neigh_lookup(&rt->dst, &ipv6_hdr(skb)->saddr); 1181 if (neigh == NULL) { 1182 ND_PRINTK(0, err, 1183 "RA: %s got default router without neighbour\n", 1184 __func__); 1185 ip6_rt_put(rt); 1186 return; 1187 } 1188 neigh->flags |= NTF_ROUTER; 1189 } else if (rt) { 1190 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 1191 } 1192 1193 if (rt) 1194 rt6_set_expires(rt, jiffies + (HZ * lifetime)); 1195 if (ra_msg->icmph.icmp6_hop_limit) { 1196 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit; 1197 if (rt) 1198 dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 1199 ra_msg->icmph.icmp6_hop_limit); 1200 } 1201 1202skip_defrtr: 1203 1204 /* 1205 * Update Reachable Time and Retrans Timer 1206 */ 1207 1208 if (in6_dev->nd_parms) { 1209 unsigned long rtime = ntohl(ra_msg->retrans_timer); 1210 1211 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) { 1212 rtime = (rtime*HZ)/1000; 1213 if (rtime < HZ/10) 1214 rtime = HZ/10; 1215 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime); 1216 in6_dev->tstamp = jiffies; 1217 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1218 } 1219 1220 rtime = ntohl(ra_msg->reachable_time); 1221 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) { 1222 rtime = (rtime*HZ)/1000; 1223 1224 if (rtime < HZ/10) 1225 rtime = HZ/10; 1226 1227 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) { 1228 NEIGH_VAR_SET(in6_dev->nd_parms, 1229 BASE_REACHABLE_TIME, rtime); 1230 NEIGH_VAR_SET(in6_dev->nd_parms, 1231 GC_STALETIME, 3 * rtime); 1232 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime); 1233 in6_dev->tstamp = jiffies; 1234 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1235 } 1236 } 1237 } 1238 1239skip_linkparms: 1240 1241 /* 1242 * Process options. 1243 */ 1244 1245 if (!neigh) 1246 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr, 1247 skb->dev, 1); 1248 if (neigh) { 1249 u8 *lladdr = NULL; 1250 if (ndopts.nd_opts_src_lladdr) { 1251 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1252 skb->dev); 1253 if (!lladdr) { 1254 ND_PRINTK(2, warn, 1255 "RA: invalid link-layer address length\n"); 1256 goto out; 1257 } 1258 } 1259 neigh_update(neigh, lladdr, NUD_STALE, 1260 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1261 NEIGH_UPDATE_F_OVERRIDE| 1262 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1263 NEIGH_UPDATE_F_ISROUTER); 1264 } 1265 1266 if (!ipv6_accept_ra(in6_dev)) 1267 goto out; 1268 1269#ifdef CONFIG_IPV6_ROUTE_INFO 1270 if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0)) 1271 goto skip_routeinfo; 1272 1273 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) { 1274 struct nd_opt_hdr *p; 1275 for (p = ndopts.nd_opts_ri; 1276 p; 1277 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) { 1278 struct route_info *ri = (struct route_info *)p; 1279#ifdef CONFIG_IPV6_NDISC_NODETYPE 1280 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT && 1281 ri->prefix_len == 0) 1282 continue; 1283#endif 1284 if (ri->prefix_len == 0 && 1285 !in6_dev->cnf.accept_ra_defrtr) 1286 continue; 1287 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen) 1288 continue; 1289 rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3, 1290 &ipv6_hdr(skb)->saddr); 1291 } 1292 } 1293 1294skip_routeinfo: 1295#endif 1296 1297#ifdef CONFIG_IPV6_NDISC_NODETYPE 1298 /* skip link-specific ndopts from interior routers */ 1299 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) 1300 goto out; 1301#endif 1302 1303 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) { 1304 struct nd_opt_hdr *p; 1305 for (p = ndopts.nd_opts_pi; 1306 p; 1307 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) { 1308 addrconf_prefix_rcv(skb->dev, (u8 *)p, 1309 (p->nd_opt_len) << 3, 1310 ndopts.nd_opts_src_lladdr != NULL); 1311 } 1312 } 1313 1314 if (ndopts.nd_opts_mtu) { 1315 __be32 n; 1316 u32 mtu; 1317 1318 memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); 1319 mtu = ntohl(n); 1320 1321 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { 1322 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu); 1323 } else if (in6_dev->cnf.mtu6 != mtu) { 1324 in6_dev->cnf.mtu6 = mtu; 1325 1326 if (rt) 1327 dst_metric_set(&rt->dst, RTAX_MTU, mtu); 1328 1329 rt6_mtu_change(skb->dev, mtu); 1330 } 1331 } 1332 1333 if (ndopts.nd_useropts) { 1334 struct nd_opt_hdr *p; 1335 for (p = ndopts.nd_useropts; 1336 p; 1337 p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) { 1338 ndisc_ra_useropt(skb, p); 1339 } 1340 } 1341 1342 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { 1343 ND_PRINTK(2, warn, "RA: invalid RA options\n"); 1344 } 1345out: 1346 ip6_rt_put(rt); 1347 if (neigh) 1348 neigh_release(neigh); 1349} 1350 1351static void ndisc_redirect_rcv(struct sk_buff *skb) 1352{ 1353 u8 *hdr; 1354 struct ndisc_options ndopts; 1355 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb); 1356 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 1357 offsetof(struct rd_msg, opt)); 1358 1359#ifdef CONFIG_IPV6_NDISC_NODETYPE 1360 switch (skb->ndisc_nodetype) { 1361 case NDISC_NODETYPE_HOST: 1362 case NDISC_NODETYPE_NODEFAULT: 1363 ND_PRINTK(2, warn, 1364 "Redirect: from host or unauthorized router\n"); 1365 return; 1366 } 1367#endif 1368 1369 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1370 ND_PRINTK(2, warn, 1371 "Redirect: source address is not link-local\n"); 1372 return; 1373 } 1374 1375 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) 1376 return; 1377 1378 if (!ndopts.nd_opts_rh) { 1379 ip6_redirect_no_header(skb, dev_net(skb->dev), 1380 skb->dev->ifindex, 0); 1381 return; 1382 } 1383 1384 hdr = (u8 *)ndopts.nd_opts_rh; 1385 hdr += 8; 1386 if (!pskb_pull(skb, hdr - skb_transport_header(skb))) 1387 return; 1388 1389 icmpv6_notify(skb, NDISC_REDIRECT, 0, 0); 1390} 1391 1392static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb, 1393 struct sk_buff *orig_skb, 1394 int rd_len) 1395{ 1396 u8 *opt = skb_put(skb, rd_len); 1397 1398 memset(opt, 0, 8); 1399 *(opt++) = ND_OPT_REDIRECT_HDR; 1400 *(opt++) = (rd_len >> 3); 1401 opt += 6; 1402 1403 memcpy(opt, ipv6_hdr(orig_skb), rd_len - 8); 1404} 1405 1406void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target) 1407{ 1408 struct net_device *dev = skb->dev; 1409 struct net *net = dev_net(dev); 1410 struct sock *sk = net->ipv6.ndisc_sk; 1411 int optlen = 0; 1412 struct inet_peer *peer; 1413 struct sk_buff *buff; 1414 struct rd_msg *msg; 1415 struct in6_addr saddr_buf; 1416 struct rt6_info *rt; 1417 struct dst_entry *dst; 1418 struct flowi6 fl6; 1419 int rd_len; 1420 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL; 1421 bool ret; 1422 1423 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) { 1424 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n", 1425 dev->name); 1426 return; 1427 } 1428 1429 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) && 1430 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1431 ND_PRINTK(2, warn, 1432 "Redirect: target address is not link-local unicast\n"); 1433 return; 1434 } 1435 1436 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT, 1437 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex); 1438 1439 dst = ip6_route_output(net, NULL, &fl6); 1440 if (dst->error) { 1441 dst_release(dst); 1442 return; 1443 } 1444 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); 1445 if (IS_ERR(dst)) 1446 return; 1447 1448 rt = (struct rt6_info *) dst; 1449 1450 if (rt->rt6i_flags & RTF_GATEWAY) { 1451 ND_PRINTK(2, warn, 1452 "Redirect: destination is not a neighbour\n"); 1453 goto release; 1454 } 1455 peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1); 1456 ret = inet_peer_xrlim_allow(peer, 1*HZ); 1457 if (peer) 1458 inet_putpeer(peer); 1459 if (!ret) 1460 goto release; 1461 1462 if (dev->addr_len) { 1463 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target); 1464 if (!neigh) { 1465 ND_PRINTK(2, warn, 1466 "Redirect: no neigh for target address\n"); 1467 goto release; 1468 } 1469 1470 read_lock_bh(&neigh->lock); 1471 if (neigh->nud_state & NUD_VALID) { 1472 memcpy(ha_buf, neigh->ha, dev->addr_len); 1473 read_unlock_bh(&neigh->lock); 1474 ha = ha_buf; 1475 optlen += ndisc_opt_addr_space(dev); 1476 } else 1477 read_unlock_bh(&neigh->lock); 1478 1479 neigh_release(neigh); 1480 } 1481 1482 rd_len = min_t(unsigned int, 1483 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen, 1484 skb->len + 8); 1485 rd_len &= ~0x7; 1486 optlen += rd_len; 1487 1488 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 1489 if (!buff) 1490 goto release; 1491 1492 msg = (struct rd_msg *)skb_put(buff, sizeof(*msg)); 1493 *msg = (struct rd_msg) { 1494 .icmph = { 1495 .icmp6_type = NDISC_REDIRECT, 1496 }, 1497 .target = *target, 1498 .dest = ipv6_hdr(skb)->daddr, 1499 }; 1500 1501 /* 1502 * include target_address option 1503 */ 1504 1505 if (ha) 1506 ndisc_fill_addr_option(buff, ND_OPT_TARGET_LL_ADDR, ha); 1507 1508 /* 1509 * build redirect option and copy skb over to the new packet. 1510 */ 1511 1512 if (rd_len) 1513 ndisc_fill_redirect_hdr_option(buff, skb, rd_len); 1514 1515 skb_dst_set(buff, dst); 1516 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf); 1517 return; 1518 1519release: 1520 dst_release(dst); 1521} 1522 1523static void pndisc_redo(struct sk_buff *skb) 1524{ 1525 ndisc_recv_ns(skb); 1526 kfree_skb(skb); 1527} 1528 1529static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb) 1530{ 1531 struct inet6_dev *idev = __in6_dev_get(skb->dev); 1532 1533 if (!idev) 1534 return true; 1535 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED && 1536 idev->cnf.suppress_frag_ndisc) { 1537 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n"); 1538 return true; 1539 } 1540 return false; 1541} 1542 1543int ndisc_rcv(struct sk_buff *skb) 1544{ 1545 struct nd_msg *msg; 1546 1547 if (ndisc_suppress_frag_ndisc(skb)) 1548 return 0; 1549 1550 if (skb_linearize(skb)) 1551 return 0; 1552 1553 msg = (struct nd_msg *)skb_transport_header(skb); 1554 1555 __skb_push(skb, skb->data - skb_transport_header(skb)); 1556 1557 if (ipv6_hdr(skb)->hop_limit != 255) { 1558 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n", 1559 ipv6_hdr(skb)->hop_limit); 1560 return 0; 1561 } 1562 1563 if (msg->icmph.icmp6_code != 0) { 1564 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n", 1565 msg->icmph.icmp6_code); 1566 return 0; 1567 } 1568 1569 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 1570 1571 switch (msg->icmph.icmp6_type) { 1572 case NDISC_NEIGHBOUR_SOLICITATION: 1573 ndisc_recv_ns(skb); 1574 break; 1575 1576 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1577 ndisc_recv_na(skb); 1578 break; 1579 1580 case NDISC_ROUTER_SOLICITATION: 1581 ndisc_recv_rs(skb); 1582 break; 1583 1584 case NDISC_ROUTER_ADVERTISEMENT: 1585 ndisc_router_discovery(skb); 1586 break; 1587 1588 case NDISC_REDIRECT: 1589 ndisc_redirect_rcv(skb); 1590 break; 1591 } 1592 1593 return 0; 1594} 1595 1596static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1597{ 1598 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1599 struct net *net = dev_net(dev); 1600 struct inet6_dev *idev; 1601 1602 switch (event) { 1603 case NETDEV_CHANGEADDR: 1604 neigh_changeaddr(&nd_tbl, dev); 1605 fib6_run_gc(0, net, false); 1606 idev = in6_dev_get(dev); 1607 if (!idev) 1608 break; 1609 if (idev->cnf.ndisc_notify) 1610 ndisc_send_unsol_na(dev); 1611 in6_dev_put(idev); 1612 break; 1613 case NETDEV_DOWN: 1614 neigh_ifdown(&nd_tbl, dev); 1615 fib6_run_gc(0, net, false); 1616 break; 1617 case NETDEV_NOTIFY_PEERS: 1618 ndisc_send_unsol_na(dev); 1619 break; 1620 default: 1621 break; 1622 } 1623 1624 return NOTIFY_DONE; 1625} 1626 1627static struct notifier_block ndisc_netdev_notifier = { 1628 .notifier_call = ndisc_netdev_event, 1629}; 1630 1631#ifdef CONFIG_SYSCTL 1632static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl, 1633 const char *func, const char *dev_name) 1634{ 1635 static char warncomm[TASK_COMM_LEN]; 1636 static int warned; 1637 if (strcmp(warncomm, current->comm) && warned < 5) { 1638 strcpy(warncomm, current->comm); 1639 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n", 1640 warncomm, func, 1641 dev_name, ctl->procname, 1642 dev_name, ctl->procname); 1643 warned++; 1644 } 1645} 1646 1647int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos) 1648{ 1649 struct net_device *dev = ctl->extra1; 1650 struct inet6_dev *idev; 1651 int ret; 1652 1653 if ((strcmp(ctl->procname, "retrans_time") == 0) || 1654 (strcmp(ctl->procname, "base_reachable_time") == 0)) 1655 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default"); 1656 1657 if (strcmp(ctl->procname, "retrans_time") == 0) 1658 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos); 1659 1660 else if (strcmp(ctl->procname, "base_reachable_time") == 0) 1661 ret = neigh_proc_dointvec_jiffies(ctl, write, 1662 buffer, lenp, ppos); 1663 1664 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) || 1665 (strcmp(ctl->procname, "base_reachable_time_ms") == 0)) 1666 ret = neigh_proc_dointvec_ms_jiffies(ctl, write, 1667 buffer, lenp, ppos); 1668 else 1669 ret = -1; 1670 1671 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) { 1672 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)) 1673 idev->nd_parms->reachable_time = 1674 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)); 1675 idev->tstamp = jiffies; 1676 inet6_ifinfo_notify(RTM_NEWLINK, idev); 1677 in6_dev_put(idev); 1678 } 1679 return ret; 1680} 1681 1682 1683#endif 1684 1685static int __net_init ndisc_net_init(struct net *net) 1686{ 1687 struct ipv6_pinfo *np; 1688 struct sock *sk; 1689 int err; 1690 1691 err = inet_ctl_sock_create(&sk, PF_INET6, 1692 SOCK_RAW, IPPROTO_ICMPV6, net); 1693 if (err < 0) { 1694 ND_PRINTK(0, err, 1695 "NDISC: Failed to initialize the control socket (err %d)\n", 1696 err); 1697 return err; 1698 } 1699 1700 net->ipv6.ndisc_sk = sk; 1701 1702 np = inet6_sk(sk); 1703 np->hop_limit = 255; 1704 /* Do not loopback ndisc messages */ 1705 np->mc_loop = 0; 1706 1707 return 0; 1708} 1709 1710static void __net_exit ndisc_net_exit(struct net *net) 1711{ 1712 inet_ctl_sock_destroy(net->ipv6.ndisc_sk); 1713} 1714 1715static struct pernet_operations ndisc_net_ops = { 1716 .init = ndisc_net_init, 1717 .exit = ndisc_net_exit, 1718}; 1719 1720int __init ndisc_init(void) 1721{ 1722 int err; 1723 1724 err = register_pernet_subsys(&ndisc_net_ops); 1725 if (err) 1726 return err; 1727 /* 1728 * Initialize the neighbour table 1729 */ 1730 neigh_table_init(&nd_tbl); 1731 1732#ifdef CONFIG_SYSCTL 1733 err = neigh_sysctl_register(NULL, &nd_tbl.parms, "ipv6", 1734 &ndisc_ifinfo_sysctl_change); 1735 if (err) 1736 goto out_unregister_pernet; 1737out: 1738#endif 1739 return err; 1740 1741#ifdef CONFIG_SYSCTL 1742out_unregister_pernet: 1743 unregister_pernet_subsys(&ndisc_net_ops); 1744 goto out; 1745#endif 1746} 1747 1748int __init ndisc_late_init(void) 1749{ 1750 return register_netdevice_notifier(&ndisc_netdev_notifier); 1751} 1752 1753void ndisc_late_cleanup(void) 1754{ 1755 unregister_netdevice_notifier(&ndisc_netdev_notifier); 1756} 1757 1758void ndisc_cleanup(void) 1759{ 1760#ifdef CONFIG_SYSCTL 1761 neigh_sysctl_unregister(&nd_tbl.parms); 1762#endif 1763 neigh_table_clear(&nd_tbl); 1764 unregister_pernet_subsys(&ndisc_net_ops); 1765} 1766