1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * Neighbour Discovery for IPv6 4 * Linux INET6 implementation 5 * 6 * Authors: 7 * Pedro Roque <roque@di.fc.ul.pt> 8 * Mike Shaver <shaver@ingenia.com> 9 */ 10 11/* 12 * Changes: 13 * 14 * Alexey I. Froloff : RFC6106 (DNSSL) support 15 * Pierre Ynard : export userland ND options 16 * through netlink (RDNSS support) 17 * Lars Fenneberg : fixed MTU setting on receipt 18 * of an RA. 19 * Janos Farkas : kmalloc failure checks 20 * Alexey Kuznetsov : state machine reworked 21 * and moved to net/core. 22 * Pekka Savola : RFC2461 validation 23 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly 24 */ 25 26#define pr_fmt(fmt) "ICMPv6: " fmt 27 28#include <linux/module.h> 29#include <linux/errno.h> 30#include <linux/types.h> 31#include <linux/socket.h> 32#include <linux/sockios.h> 33#include <linux/sched.h> 34#include <linux/net.h> 35#include <linux/in6.h> 36#include <linux/route.h> 37#include <linux/init.h> 38#include <linux/rcupdate.h> 39#include <linux/slab.h> 40#ifdef CONFIG_SYSCTL 41#include <linux/sysctl.h> 42#endif 43 44#include <linux/if_addr.h> 45#include <linux/if_ether.h> 46#include <linux/if_arp.h> 47#include <linux/ipv6.h> 48#include <linux/icmpv6.h> 49#include <linux/jhash.h> 50 51#include <net/sock.h> 52#include <net/snmp.h> 53 54#include <net/ipv6.h> 55#include <net/protocol.h> 56#include <net/ndisc.h> 57#include <net/ip6_route.h> 58#include <net/addrconf.h> 59#include <net/icmp.h> 60 61#include <net/netlink.h> 62#include <linux/rtnetlink.h> 63 64#include <net/flow.h> 65#include <net/ip6_checksum.h> 66#include <net/inet_common.h> 67#include <linux/proc_fs.h> 68 69#include <linux/netfilter.h> 70#include <linux/netfilter_ipv6.h> 71 72static u32 ndisc_hash(const void *pkey, 73 const struct net_device *dev, 74 __u32 *hash_rnd); 75static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey); 76static bool ndisc_allow_add(const struct net_device *dev, 77 struct netlink_ext_ack *extack); 78static int ndisc_constructor(struct neighbour *neigh); 79static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb); 80static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb); 81static int pndisc_constructor(struct pneigh_entry *n); 82static void pndisc_destructor(struct pneigh_entry *n); 83static void pndisc_redo(struct sk_buff *skb); 84static int ndisc_is_multicast(const void *pkey); 85 86static const struct neigh_ops ndisc_generic_ops = { 87 .family = AF_INET6, 88 .solicit = ndisc_solicit, 89 .error_report = ndisc_error_report, 90 .output = neigh_resolve_output, 91 .connected_output = neigh_connected_output, 92}; 93 94static const struct neigh_ops ndisc_hh_ops = { 95 .family = AF_INET6, 96 .solicit = ndisc_solicit, 97 .error_report = ndisc_error_report, 98 .output = neigh_resolve_output, 99 .connected_output = neigh_resolve_output, 100}; 101 102 103static const struct neigh_ops ndisc_direct_ops = { 104 .family = AF_INET6, 105 .output = neigh_direct_output, 106 .connected_output = neigh_direct_output, 107}; 108 109struct neigh_table nd_tbl = { 110 .family = AF_INET6, 111 .key_len = sizeof(struct in6_addr), 112 .protocol = cpu_to_be16(ETH_P_IPV6), 113 .hash = ndisc_hash, 114 .key_eq = ndisc_key_eq, 115 .constructor = ndisc_constructor, 116 .pconstructor = pndisc_constructor, 117 .pdestructor = pndisc_destructor, 118 .proxy_redo = pndisc_redo, 119 .is_multicast = ndisc_is_multicast, 120 .allow_add = ndisc_allow_add, 121 .id = "ndisc_cache", 122 .parms = { 123 .tbl = &nd_tbl, 124 .reachable_time = ND_REACHABLE_TIME, 125 .data = { 126 [NEIGH_VAR_MCAST_PROBES] = 3, 127 [NEIGH_VAR_UCAST_PROBES] = 3, 128 [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER, 129 [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME, 130 [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ, 131 [NEIGH_VAR_INTERVAL_PROBE_TIME_MS] = 5 * HZ, 132 [NEIGH_VAR_GC_STALETIME] = 60 * HZ, 133 [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX, 134 [NEIGH_VAR_PROXY_QLEN] = 64, 135 [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ, 136 [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10, 137 }, 138 }, 139 .gc_interval = 30 * HZ, 140 .gc_thresh1 = 128, 141 .gc_thresh2 = 512, 142 .gc_thresh3 = 1024, 143}; 144EXPORT_SYMBOL_GPL(nd_tbl); 145 146void __ndisc_fill_addr_option(struct sk_buff *skb, int type, const void *data, 147 int data_len, int pad) 148{ 149 int space = __ndisc_opt_addr_space(data_len, pad); 150 u8 *opt = skb_put(skb, space); 151 152 opt[0] = type; 153 opt[1] = space>>3; 154 155 memset(opt + 2, 0, pad); 156 opt += pad; 157 space -= pad; 158 159 memcpy(opt+2, data, data_len); 160 data_len += 2; 161 opt += data_len; 162 space -= data_len; 163 if (space > 0) 164 memset(opt, 0, space); 165} 166EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option); 167 168static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type, 169 const void *data, u8 icmp6_type) 170{ 171 __ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len, 172 ndisc_addr_option_pad(skb->dev->type)); 173 ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type); 174} 175 176static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb, 177 void *ha, 178 const u8 *ops_data) 179{ 180 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT); 181 ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data); 182} 183 184static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur, 185 struct nd_opt_hdr *end) 186{ 187 int type; 188 if (!cur || !end || cur >= end) 189 return NULL; 190 type = cur->nd_opt_type; 191 do { 192 cur = ((void *)cur) + (cur->nd_opt_len << 3); 193 } while (cur < end && cur->nd_opt_type != type); 194 return cur <= end && cur->nd_opt_type == type ? cur : NULL; 195} 196 197static inline int ndisc_is_useropt(const struct net_device *dev, 198 struct nd_opt_hdr *opt) 199{ 200 return opt->nd_opt_type == ND_OPT_PREFIX_INFO || 201 opt->nd_opt_type == ND_OPT_RDNSS || 202 opt->nd_opt_type == ND_OPT_DNSSL || 203 opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL || 204 opt->nd_opt_type == ND_OPT_PREF64 || 205 ndisc_ops_is_useropt(dev, opt->nd_opt_type); 206} 207 208static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev, 209 struct nd_opt_hdr *cur, 210 struct nd_opt_hdr *end) 211{ 212 if (!cur || !end || cur >= end) 213 return NULL; 214 do { 215 cur = ((void *)cur) + (cur->nd_opt_len << 3); 216 } while (cur < end && !ndisc_is_useropt(dev, cur)); 217 return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL; 218} 219 220struct ndisc_options *ndisc_parse_options(const struct net_device *dev, 221 u8 *opt, int opt_len, 222 struct ndisc_options *ndopts) 223{ 224 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt; 225 226 if (!nd_opt || opt_len < 0 || !ndopts) 227 return NULL; 228 memset(ndopts, 0, sizeof(*ndopts)); 229 while (opt_len) { 230 int l; 231 if (opt_len < sizeof(struct nd_opt_hdr)) 232 return NULL; 233 l = nd_opt->nd_opt_len << 3; 234 if (opt_len < l || l == 0) 235 return NULL; 236 if (ndisc_ops_parse_options(dev, nd_opt, ndopts)) 237 goto next_opt; 238 switch (nd_opt->nd_opt_type) { 239 case ND_OPT_SOURCE_LL_ADDR: 240 case ND_OPT_TARGET_LL_ADDR: 241 case ND_OPT_MTU: 242 case ND_OPT_NONCE: 243 case ND_OPT_REDIRECT_HDR: 244 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { 245 ND_PRINTK(2, warn, 246 "%s: duplicated ND6 option found: type=%d\n", 247 __func__, nd_opt->nd_opt_type); 248 } else { 249 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; 250 } 251 break; 252 case ND_OPT_PREFIX_INFO: 253 ndopts->nd_opts_pi_end = nd_opt; 254 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type]) 255 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; 256 break; 257#ifdef CONFIG_IPV6_ROUTE_INFO 258 case ND_OPT_ROUTE_INFO: 259 ndopts->nd_opts_ri_end = nd_opt; 260 if (!ndopts->nd_opts_ri) 261 ndopts->nd_opts_ri = nd_opt; 262 break; 263#endif 264 default: 265 if (ndisc_is_useropt(dev, nd_opt)) { 266 ndopts->nd_useropts_end = nd_opt; 267 if (!ndopts->nd_useropts) 268 ndopts->nd_useropts = nd_opt; 269 } else { 270 /* 271 * Unknown options must be silently ignored, 272 * to accommodate future extension to the 273 * protocol. 274 */ 275 ND_PRINTK(2, notice, 276 "%s: ignored unsupported option; type=%d, len=%d\n", 277 __func__, 278 nd_opt->nd_opt_type, 279 nd_opt->nd_opt_len); 280 } 281 } 282next_opt: 283 opt_len -= l; 284 nd_opt = ((void *)nd_opt) + l; 285 } 286 return ndopts; 287} 288 289int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir) 290{ 291 switch (dev->type) { 292 case ARPHRD_ETHER: 293 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */ 294 case ARPHRD_FDDI: 295 ipv6_eth_mc_map(addr, buf); 296 return 0; 297 case ARPHRD_ARCNET: 298 ipv6_arcnet_mc_map(addr, buf); 299 return 0; 300 case ARPHRD_INFINIBAND: 301 ipv6_ib_mc_map(addr, dev->broadcast, buf); 302 return 0; 303 case ARPHRD_IPGRE: 304 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf); 305 default: 306 if (dir) { 307 memcpy(buf, dev->broadcast, dev->addr_len); 308 return 0; 309 } 310 } 311 return -EINVAL; 312} 313EXPORT_SYMBOL(ndisc_mc_map); 314 315static u32 ndisc_hash(const void *pkey, 316 const struct net_device *dev, 317 __u32 *hash_rnd) 318{ 319 return ndisc_hashfn(pkey, dev, hash_rnd); 320} 321 322static bool ndisc_key_eq(const struct neighbour *n, const void *pkey) 323{ 324 return neigh_key_eq128(n, pkey); 325} 326 327static int ndisc_constructor(struct neighbour *neigh) 328{ 329 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key; 330 struct net_device *dev = neigh->dev; 331 struct inet6_dev *in6_dev; 332 struct neigh_parms *parms; 333 bool is_multicast = ipv6_addr_is_multicast(addr); 334 335 in6_dev = in6_dev_get(dev); 336 if (!in6_dev) { 337 return -EINVAL; 338 } 339 340 parms = in6_dev->nd_parms; 341 __neigh_parms_put(neigh->parms); 342 neigh->parms = neigh_parms_clone(parms); 343 344 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST; 345 if (!dev->header_ops) { 346 neigh->nud_state = NUD_NOARP; 347 neigh->ops = &ndisc_direct_ops; 348 neigh->output = neigh_direct_output; 349 } else { 350 if (is_multicast) { 351 neigh->nud_state = NUD_NOARP; 352 ndisc_mc_map(addr, neigh->ha, dev, 1); 353 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { 354 neigh->nud_state = NUD_NOARP; 355 memcpy(neigh->ha, dev->dev_addr, dev->addr_len); 356 if (dev->flags&IFF_LOOPBACK) 357 neigh->type = RTN_LOCAL; 358 } else if (dev->flags&IFF_POINTOPOINT) { 359 neigh->nud_state = NUD_NOARP; 360 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 361 } 362 if (dev->header_ops->cache) 363 neigh->ops = &ndisc_hh_ops; 364 else 365 neigh->ops = &ndisc_generic_ops; 366 if (neigh->nud_state&NUD_VALID) 367 neigh->output = neigh->ops->connected_output; 368 else 369 neigh->output = neigh->ops->output; 370 } 371 in6_dev_put(in6_dev); 372 return 0; 373} 374 375static int pndisc_constructor(struct pneigh_entry *n) 376{ 377 struct in6_addr *addr = (struct in6_addr *)&n->key; 378 struct in6_addr maddr; 379 struct net_device *dev = n->dev; 380 381 if (!dev || !__in6_dev_get(dev)) 382 return -EINVAL; 383 addrconf_addr_solict_mult(addr, &maddr); 384 ipv6_dev_mc_inc(dev, &maddr); 385 return 0; 386} 387 388static void pndisc_destructor(struct pneigh_entry *n) 389{ 390 struct in6_addr *addr = (struct in6_addr *)&n->key; 391 struct in6_addr maddr; 392 struct net_device *dev = n->dev; 393 394 if (!dev || !__in6_dev_get(dev)) 395 return; 396 addrconf_addr_solict_mult(addr, &maddr); 397 ipv6_dev_mc_dec(dev, &maddr); 398} 399 400/* called with rtnl held */ 401static bool ndisc_allow_add(const struct net_device *dev, 402 struct netlink_ext_ack *extack) 403{ 404 struct inet6_dev *idev = __in6_dev_get(dev); 405 406 if (!idev || idev->cnf.disable_ipv6) { 407 NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device"); 408 return false; 409 } 410 411 return true; 412} 413 414static struct sk_buff *ndisc_alloc_skb(struct net_device *dev, 415 int len) 416{ 417 int hlen = LL_RESERVED_SPACE(dev); 418 int tlen = dev->needed_tailroom; 419 struct sock *sk = dev_net(dev)->ipv6.ndisc_sk; 420 struct sk_buff *skb; 421 422 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC); 423 if (!skb) { 424 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n", 425 __func__); 426 return NULL; 427 } 428 429 skb->protocol = htons(ETH_P_IPV6); 430 skb->dev = dev; 431 432 skb_reserve(skb, hlen + sizeof(struct ipv6hdr)); 433 skb_reset_transport_header(skb); 434 435 /* Manually assign socket ownership as we avoid calling 436 * sock_alloc_send_pskb() to bypass wmem buffer limits 437 */ 438 skb_set_owner_w(skb, sk); 439 440 return skb; 441} 442 443static void ip6_nd_hdr(struct sk_buff *skb, 444 const struct in6_addr *saddr, 445 const struct in6_addr *daddr, 446 int hop_limit, int len) 447{ 448 struct ipv6hdr *hdr; 449 struct inet6_dev *idev; 450 unsigned tclass; 451 452 rcu_read_lock(); 453 idev = __in6_dev_get(skb->dev); 454 tclass = idev ? READ_ONCE(idev->cnf.ndisc_tclass) : 0; 455 rcu_read_unlock(); 456 457 skb_push(skb, sizeof(*hdr)); 458 skb_reset_network_header(skb); 459 hdr = ipv6_hdr(skb); 460 461 ip6_flow_hdr(hdr, tclass, 0); 462 463 hdr->payload_len = htons(len); 464 hdr->nexthdr = IPPROTO_ICMPV6; 465 hdr->hop_limit = hop_limit; 466 467 hdr->saddr = *saddr; 468 hdr->daddr = *daddr; 469} 470 471void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr, 472 const struct in6_addr *saddr) 473{ 474 struct dst_entry *dst = skb_dst(skb); 475 struct net *net = dev_net(skb->dev); 476 struct sock *sk = net->ipv6.ndisc_sk; 477 struct inet6_dev *idev; 478 int err; 479 struct icmp6hdr *icmp6h = icmp6_hdr(skb); 480 u8 type; 481 482 type = icmp6h->icmp6_type; 483 484 if (!dst) { 485 struct flowi6 fl6; 486 int oif = skb->dev->ifindex; 487 488 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif); 489 dst = icmp6_dst_alloc(skb->dev, &fl6); 490 if (IS_ERR(dst)) { 491 kfree_skb(skb); 492 return; 493 } 494 495 skb_dst_set(skb, dst); 496 } 497 498 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len, 499 IPPROTO_ICMPV6, 500 csum_partial(icmp6h, 501 skb->len, 0)); 502 503 ip6_nd_hdr(skb, saddr, daddr, READ_ONCE(inet6_sk(sk)->hop_limit), skb->len); 504 505 rcu_read_lock(); 506 idev = __in6_dev_get(dst->dev); 507 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS); 508 509 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, 510 net, sk, skb, NULL, dst->dev, 511 dst_output); 512 if (!err) { 513 ICMP6MSGOUT_INC_STATS(net, idev, type); 514 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 515 } 516 517 rcu_read_unlock(); 518} 519EXPORT_SYMBOL(ndisc_send_skb); 520 521void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr, 522 const struct in6_addr *solicited_addr, 523 bool router, bool solicited, bool override, bool inc_opt) 524{ 525 struct sk_buff *skb; 526 struct in6_addr tmpaddr; 527 struct inet6_ifaddr *ifp; 528 const struct in6_addr *src_addr; 529 struct nd_msg *msg; 530 int optlen = 0; 531 532 /* for anycast or proxy, solicited_addr != src_addr */ 533 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1); 534 if (ifp) { 535 src_addr = solicited_addr; 536 if (ifp->flags & IFA_F_OPTIMISTIC) 537 override = false; 538 inc_opt |= READ_ONCE(ifp->idev->cnf.force_tllao); 539 in6_ifa_put(ifp); 540 } else { 541 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr, 542 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs, 543 &tmpaddr)) 544 return; 545 src_addr = &tmpaddr; 546 } 547 548 if (!dev->addr_len) 549 inc_opt = false; 550 if (inc_opt) 551 optlen += ndisc_opt_addr_space(dev, 552 NDISC_NEIGHBOUR_ADVERTISEMENT); 553 554 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 555 if (!skb) 556 return; 557 558 msg = skb_put(skb, sizeof(*msg)); 559 *msg = (struct nd_msg) { 560 .icmph = { 561 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT, 562 .icmp6_router = router, 563 .icmp6_solicited = solicited, 564 .icmp6_override = override, 565 }, 566 .target = *solicited_addr, 567 }; 568 569 if (inc_opt) 570 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, 571 dev->dev_addr, 572 NDISC_NEIGHBOUR_ADVERTISEMENT); 573 574 ndisc_send_skb(skb, daddr, src_addr); 575} 576 577static void ndisc_send_unsol_na(struct net_device *dev) 578{ 579 struct inet6_dev *idev; 580 struct inet6_ifaddr *ifa; 581 582 idev = in6_dev_get(dev); 583 if (!idev) 584 return; 585 586 read_lock_bh(&idev->lock); 587 list_for_each_entry(ifa, &idev->addr_list, if_list) { 588 /* skip tentative addresses until dad completes */ 589 if (ifa->flags & IFA_F_TENTATIVE && 590 !(ifa->flags & IFA_F_OPTIMISTIC)) 591 continue; 592 593 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr, 594 /*router=*/ !!idev->cnf.forwarding, 595 /*solicited=*/ false, /*override=*/ true, 596 /*inc_opt=*/ true); 597 } 598 read_unlock_bh(&idev->lock); 599 600 in6_dev_put(idev); 601} 602 603struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit, 604 const struct in6_addr *saddr, u64 nonce) 605{ 606 int inc_opt = dev->addr_len; 607 struct sk_buff *skb; 608 struct nd_msg *msg; 609 int optlen = 0; 610 611 if (!saddr) 612 return NULL; 613 614 if (ipv6_addr_any(saddr)) 615 inc_opt = false; 616 if (inc_opt) 617 optlen += ndisc_opt_addr_space(dev, 618 NDISC_NEIGHBOUR_SOLICITATION); 619 if (nonce != 0) 620 optlen += 8; 621 622 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 623 if (!skb) 624 return NULL; 625 626 msg = skb_put(skb, sizeof(*msg)); 627 *msg = (struct nd_msg) { 628 .icmph = { 629 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION, 630 }, 631 .target = *solicit, 632 }; 633 634 if (inc_opt) 635 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR, 636 dev->dev_addr, 637 NDISC_NEIGHBOUR_SOLICITATION); 638 if (nonce != 0) { 639 u8 *opt = skb_put(skb, 8); 640 641 opt[0] = ND_OPT_NONCE; 642 opt[1] = 8 >> 3; 643 memcpy(opt + 2, &nonce, 6); 644 } 645 646 return skb; 647} 648EXPORT_SYMBOL(ndisc_ns_create); 649 650void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit, 651 const struct in6_addr *daddr, const struct in6_addr *saddr, 652 u64 nonce) 653{ 654 struct in6_addr addr_buf; 655 struct sk_buff *skb; 656 657 if (!saddr) { 658 if (ipv6_get_lladdr(dev, &addr_buf, 659 (IFA_F_TENTATIVE | IFA_F_OPTIMISTIC))) 660 return; 661 saddr = &addr_buf; 662 } 663 664 skb = ndisc_ns_create(dev, solicit, saddr, nonce); 665 666 if (skb) 667 ndisc_send_skb(skb, daddr, saddr); 668} 669 670void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr, 671 const struct in6_addr *daddr) 672{ 673 struct sk_buff *skb; 674 struct rs_msg *msg; 675 int send_sllao = dev->addr_len; 676 int optlen = 0; 677 678#ifdef CONFIG_IPV6_OPTIMISTIC_DAD 679 /* 680 * According to section 2.2 of RFC 4429, we must not 681 * send router solicitations with a sllao from 682 * optimistic addresses, but we may send the solicitation 683 * if we don't include the sllao. So here we check 684 * if our address is optimistic, and if so, we 685 * suppress the inclusion of the sllao. 686 */ 687 if (send_sllao) { 688 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr, 689 dev, 1); 690 if (ifp) { 691 if (ifp->flags & IFA_F_OPTIMISTIC) { 692 send_sllao = 0; 693 } 694 in6_ifa_put(ifp); 695 } else { 696 send_sllao = 0; 697 } 698 } 699#endif 700 if (send_sllao) 701 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION); 702 703 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 704 if (!skb) 705 return; 706 707 msg = skb_put(skb, sizeof(*msg)); 708 *msg = (struct rs_msg) { 709 .icmph = { 710 .icmp6_type = NDISC_ROUTER_SOLICITATION, 711 }, 712 }; 713 714 if (send_sllao) 715 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR, 716 dev->dev_addr, 717 NDISC_ROUTER_SOLICITATION); 718 719 ndisc_send_skb(skb, daddr, saddr); 720} 721 722 723static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb) 724{ 725 /* 726 * "The sender MUST return an ICMP 727 * destination unreachable" 728 */ 729 dst_link_failure(skb); 730 kfree_skb(skb); 731} 732 733/* Called with locked neigh: either read or both */ 734 735static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb) 736{ 737 struct in6_addr *saddr = NULL; 738 struct in6_addr mcaddr; 739 struct net_device *dev = neigh->dev; 740 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key; 741 int probes = atomic_read(&neigh->probes); 742 743 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr, 744 dev, false, 1, 745 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) 746 saddr = &ipv6_hdr(skb)->saddr; 747 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES); 748 if (probes < 0) { 749 if (!(READ_ONCE(neigh->nud_state) & NUD_VALID)) { 750 ND_PRINTK(1, dbg, 751 "%s: trying to ucast probe in NUD_INVALID: %pI6\n", 752 __func__, target); 753 } 754 ndisc_send_ns(dev, target, target, saddr, 0); 755 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) { 756 neigh_app_ns(neigh); 757 } else { 758 addrconf_addr_solict_mult(target, &mcaddr); 759 ndisc_send_ns(dev, target, &mcaddr, saddr, 0); 760 } 761} 762 763static int pndisc_is_router(const void *pkey, 764 struct net_device *dev) 765{ 766 struct pneigh_entry *n; 767 int ret = -1; 768 769 read_lock_bh(&nd_tbl.lock); 770 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev); 771 if (n) 772 ret = !!(n->flags & NTF_ROUTER); 773 read_unlock_bh(&nd_tbl.lock); 774 775 return ret; 776} 777 778void ndisc_update(const struct net_device *dev, struct neighbour *neigh, 779 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type, 780 struct ndisc_options *ndopts) 781{ 782 neigh_update(neigh, lladdr, new, flags, 0); 783 /* report ndisc ops about neighbour update */ 784 ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts); 785} 786 787static enum skb_drop_reason ndisc_recv_ns(struct sk_buff *skb) 788{ 789 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 790 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 791 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 792 u8 *lladdr = NULL; 793 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 794 offsetof(struct nd_msg, opt)); 795 struct ndisc_options ndopts; 796 struct net_device *dev = skb->dev; 797 struct inet6_ifaddr *ifp; 798 struct inet6_dev *idev = NULL; 799 struct neighbour *neigh; 800 int dad = ipv6_addr_any(saddr); 801 int is_router = -1; 802 SKB_DR(reason); 803 u64 nonce = 0; 804 bool inc; 805 806 if (skb->len < sizeof(struct nd_msg)) 807 return SKB_DROP_REASON_PKT_TOO_SMALL; 808 809 if (ipv6_addr_is_multicast(&msg->target)) { 810 ND_PRINTK(2, warn, "NS: multicast target address\n"); 811 return reason; 812 } 813 814 /* 815 * RFC2461 7.1.1: 816 * DAD has to be destined for solicited node multicast address. 817 */ 818 if (dad && !ipv6_addr_is_solict_mult(daddr)) { 819 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n"); 820 return reason; 821 } 822 823 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) 824 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 825 826 if (ndopts.nd_opts_src_lladdr) { 827 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev); 828 if (!lladdr) { 829 ND_PRINTK(2, warn, 830 "NS: invalid link-layer address length\n"); 831 return reason; 832 } 833 834 /* RFC2461 7.1.1: 835 * If the IP source address is the unspecified address, 836 * there MUST NOT be source link-layer address option 837 * in the message. 838 */ 839 if (dad) { 840 ND_PRINTK(2, warn, 841 "NS: bad DAD packet (link-layer address option)\n"); 842 return reason; 843 } 844 } 845 if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1) 846 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6); 847 848 inc = ipv6_addr_is_multicast(daddr); 849 850 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); 851 if (ifp) { 852have_ifp: 853 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) { 854 if (dad) { 855 if (nonce != 0 && ifp->dad_nonce == nonce) { 856 u8 *np = (u8 *)&nonce; 857 /* Matching nonce if looped back */ 858 ND_PRINTK(2, notice, 859 "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n", 860 ifp->idev->dev->name, 861 &ifp->addr, np); 862 goto out; 863 } 864 /* 865 * We are colliding with another node 866 * who is doing DAD 867 * so fail our DAD process 868 */ 869 addrconf_dad_failure(skb, ifp); 870 return reason; 871 } else { 872 /* 873 * This is not a dad solicitation. 874 * If we are an optimistic node, 875 * we should respond. 876 * Otherwise, we should ignore it. 877 */ 878 if (!(ifp->flags & IFA_F_OPTIMISTIC)) 879 goto out; 880 } 881 } 882 883 idev = ifp->idev; 884 } else { 885 struct net *net = dev_net(dev); 886 887 /* perhaps an address on the master device */ 888 if (netif_is_l3_slave(dev)) { 889 struct net_device *mdev; 890 891 mdev = netdev_master_upper_dev_get_rcu(dev); 892 if (mdev) { 893 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1); 894 if (ifp) 895 goto have_ifp; 896 } 897 } 898 899 idev = in6_dev_get(dev); 900 if (!idev) { 901 /* XXX: count this drop? */ 902 return reason; 903 } 904 905 if (ipv6_chk_acast_addr(net, dev, &msg->target) || 906 (READ_ONCE(idev->cnf.forwarding) && 907 (READ_ONCE(net->ipv6.devconf_all->proxy_ndp) || 908 READ_ONCE(idev->cnf.proxy_ndp)) && 909 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) { 910 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) && 911 skb->pkt_type != PACKET_HOST && 912 inc && 913 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) { 914 /* 915 * for anycast or proxy, 916 * sender should delay its response 917 * by a random time between 0 and 918 * MAX_ANYCAST_DELAY_TIME seconds. 919 * (RFC2461) -- yoshfuji 920 */ 921 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC); 922 if (n) 923 pneigh_enqueue(&nd_tbl, idev->nd_parms, n); 924 goto out; 925 } 926 } else { 927 SKB_DR_SET(reason, IPV6_NDISC_NS_OTHERHOST); 928 goto out; 929 } 930 } 931 932 if (is_router < 0) 933 is_router = READ_ONCE(idev->cnf.forwarding); 934 935 if (dad) { 936 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target, 937 !!is_router, false, (ifp != NULL), true); 938 goto out; 939 } 940 941 if (inc) 942 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast); 943 else 944 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast); 945 946 /* 947 * update / create cache entry 948 * for the source address 949 */ 950 neigh = __neigh_lookup(&nd_tbl, saddr, dev, 951 !inc || lladdr || !dev->addr_len); 952 if (neigh) 953 ndisc_update(dev, neigh, lladdr, NUD_STALE, 954 NEIGH_UPDATE_F_WEAK_OVERRIDE| 955 NEIGH_UPDATE_F_OVERRIDE, 956 NDISC_NEIGHBOUR_SOLICITATION, &ndopts); 957 if (neigh || !dev->header_ops) { 958 ndisc_send_na(dev, saddr, &msg->target, !!is_router, 959 true, (ifp != NULL && inc), inc); 960 if (neigh) 961 neigh_release(neigh); 962 reason = SKB_CONSUMED; 963 } 964 965out: 966 if (ifp) 967 in6_ifa_put(ifp); 968 else 969 in6_dev_put(idev); 970 return reason; 971} 972 973static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr) 974{ 975 struct inet6_dev *idev = __in6_dev_get(dev); 976 977 switch (READ_ONCE(idev->cnf.accept_untracked_na)) { 978 case 0: /* Don't accept untracked na (absent in neighbor cache) */ 979 return 0; 980 case 1: /* Create new entries from na if currently untracked */ 981 return 1; 982 case 2: /* Create new entries from untracked na only if saddr is in the 983 * same subnet as an address configured on the interface that 984 * received the na 985 */ 986 return !!ipv6_chk_prefix(saddr, dev); 987 default: 988 return 0; 989 } 990} 991 992static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb) 993{ 994 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 995 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 996 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 997 u8 *lladdr = NULL; 998 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 999 offsetof(struct nd_msg, opt)); 1000 struct ndisc_options ndopts; 1001 struct net_device *dev = skb->dev; 1002 struct inet6_dev *idev = __in6_dev_get(dev); 1003 struct inet6_ifaddr *ifp; 1004 struct neighbour *neigh; 1005 SKB_DR(reason); 1006 u8 new_state; 1007 1008 if (skb->len < sizeof(struct nd_msg)) 1009 return SKB_DROP_REASON_PKT_TOO_SMALL; 1010 1011 if (ipv6_addr_is_multicast(&msg->target)) { 1012 ND_PRINTK(2, warn, "NA: target address is multicast\n"); 1013 return reason; 1014 } 1015 1016 if (ipv6_addr_is_multicast(daddr) && 1017 msg->icmph.icmp6_solicited) { 1018 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n"); 1019 return reason; 1020 } 1021 1022 /* For some 802.11 wireless deployments (and possibly other networks), 1023 * there will be a NA proxy and unsolicitd packets are attacks 1024 * and thus should not be accepted. 1025 * drop_unsolicited_na takes precedence over accept_untracked_na 1026 */ 1027 if (!msg->icmph.icmp6_solicited && idev && 1028 READ_ONCE(idev->cnf.drop_unsolicited_na)) 1029 return reason; 1030 1031 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) 1032 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1033 1034 if (ndopts.nd_opts_tgt_lladdr) { 1035 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev); 1036 if (!lladdr) { 1037 ND_PRINTK(2, warn, 1038 "NA: invalid link-layer address length\n"); 1039 return reason; 1040 } 1041 } 1042 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); 1043 if (ifp) { 1044 if (skb->pkt_type != PACKET_LOOPBACK 1045 && (ifp->flags & IFA_F_TENTATIVE)) { 1046 addrconf_dad_failure(skb, ifp); 1047 return reason; 1048 } 1049 /* What should we make now? The advertisement 1050 is invalid, but ndisc specs say nothing 1051 about it. It could be misconfiguration, or 1052 an smart proxy agent tries to help us :-) 1053 1054 We should not print the error if NA has been 1055 received from loopback - it is just our own 1056 unsolicited advertisement. 1057 */ 1058 if (skb->pkt_type != PACKET_LOOPBACK) 1059 ND_PRINTK(1, warn, 1060 "NA: %pM advertised our address %pI6c on %s!\n", 1061 eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name); 1062 in6_ifa_put(ifp); 1063 return reason; 1064 } 1065 1066 neigh = neigh_lookup(&nd_tbl, &msg->target, dev); 1067 1068 /* RFC 9131 updates original Neighbour Discovery RFC 4861. 1069 * NAs with Target LL Address option without a corresponding 1070 * entry in the neighbour cache can now create a STALE neighbour 1071 * cache entry on routers. 1072 * 1073 * entry accept fwding solicited behaviour 1074 * ------- ------ ------ --------- ---------------------- 1075 * present X X 0 Set state to STALE 1076 * present X X 1 Set state to REACHABLE 1077 * absent 0 X X Do nothing 1078 * absent 1 0 X Do nothing 1079 * absent 1 1 X Add a new STALE entry 1080 * 1081 * Note that we don't do a (daddr == all-routers-mcast) check. 1082 */ 1083 new_state = msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE; 1084 if (!neigh && lladdr && idev && READ_ONCE(idev->cnf.forwarding)) { 1085 if (accept_untracked_na(dev, saddr)) { 1086 neigh = neigh_create(&nd_tbl, &msg->target, dev); 1087 new_state = NUD_STALE; 1088 } 1089 } 1090 1091 if (neigh && !IS_ERR(neigh)) { 1092 u8 old_flags = neigh->flags; 1093 struct net *net = dev_net(dev); 1094 1095 if (READ_ONCE(neigh->nud_state) & NUD_FAILED) 1096 goto out; 1097 1098 /* 1099 * Don't update the neighbor cache entry on a proxy NA from 1100 * ourselves because either the proxied node is off link or it 1101 * has already sent a NA to us. 1102 */ 1103 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) && 1104 READ_ONCE(net->ipv6.devconf_all->forwarding) && 1105 READ_ONCE(net->ipv6.devconf_all->proxy_ndp) && 1106 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) { 1107 /* XXX: idev->cnf.proxy_ndp */ 1108 goto out; 1109 } 1110 1111 ndisc_update(dev, neigh, lladdr, 1112 new_state, 1113 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1114 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)| 1115 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1116 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0), 1117 NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts); 1118 1119 if ((old_flags & ~neigh->flags) & NTF_ROUTER) { 1120 /* 1121 * Change: router to host 1122 */ 1123 rt6_clean_tohost(dev_net(dev), saddr); 1124 } 1125 reason = SKB_CONSUMED; 1126out: 1127 neigh_release(neigh); 1128 } 1129 return reason; 1130} 1131 1132static enum skb_drop_reason ndisc_recv_rs(struct sk_buff *skb) 1133{ 1134 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb); 1135 unsigned long ndoptlen = skb->len - sizeof(*rs_msg); 1136 struct neighbour *neigh; 1137 struct inet6_dev *idev; 1138 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 1139 struct ndisc_options ndopts; 1140 u8 *lladdr = NULL; 1141 SKB_DR(reason); 1142 1143 if (skb->len < sizeof(*rs_msg)) 1144 return SKB_DROP_REASON_PKT_TOO_SMALL; 1145 1146 idev = __in6_dev_get(skb->dev); 1147 if (!idev) { 1148 ND_PRINTK(1, err, "RS: can't find in6 device\n"); 1149 return reason; 1150 } 1151 1152 /* Don't accept RS if we're not in router mode */ 1153 if (!READ_ONCE(idev->cnf.forwarding)) 1154 goto out; 1155 1156 /* 1157 * Don't update NCE if src = ::; 1158 * this implies that the source node has no ip address assigned yet. 1159 */ 1160 if (ipv6_addr_any(saddr)) 1161 goto out; 1162 1163 /* Parse ND options */ 1164 if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) 1165 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1166 1167 if (ndopts.nd_opts_src_lladdr) { 1168 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1169 skb->dev); 1170 if (!lladdr) 1171 goto out; 1172 } 1173 1174 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1); 1175 if (neigh) { 1176 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE, 1177 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1178 NEIGH_UPDATE_F_OVERRIDE| 1179 NEIGH_UPDATE_F_OVERRIDE_ISROUTER, 1180 NDISC_ROUTER_SOLICITATION, &ndopts); 1181 neigh_release(neigh); 1182 reason = SKB_CONSUMED; 1183 } 1184out: 1185 return reason; 1186} 1187 1188static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt) 1189{ 1190 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra); 1191 struct sk_buff *skb; 1192 struct nlmsghdr *nlh; 1193 struct nduseroptmsg *ndmsg; 1194 struct net *net = dev_net(ra->dev); 1195 int err; 1196 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg) 1197 + (opt->nd_opt_len << 3)); 1198 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr)); 1199 1200 skb = nlmsg_new(msg_size, GFP_ATOMIC); 1201 if (!skb) { 1202 err = -ENOBUFS; 1203 goto errout; 1204 } 1205 1206 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0); 1207 if (!nlh) { 1208 goto nla_put_failure; 1209 } 1210 1211 ndmsg = nlmsg_data(nlh); 1212 ndmsg->nduseropt_family = AF_INET6; 1213 ndmsg->nduseropt_ifindex = ra->dev->ifindex; 1214 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type; 1215 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code; 1216 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3; 1217 1218 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3); 1219 1220 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr)) 1221 goto nla_put_failure; 1222 nlmsg_end(skb, nlh); 1223 1224 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC); 1225 return; 1226 1227nla_put_failure: 1228 nlmsg_free(skb); 1229 err = -EMSGSIZE; 1230errout: 1231 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err); 1232} 1233 1234static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb) 1235{ 1236 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb); 1237 bool send_ifinfo_notify = false; 1238 struct neighbour *neigh = NULL; 1239 struct ndisc_options ndopts; 1240 struct fib6_info *rt = NULL; 1241 struct inet6_dev *in6_dev; 1242 struct fib6_table *table; 1243 u32 defrtr_usr_metric; 1244 unsigned int pref = 0; 1245 __u32 old_if_flags; 1246 struct net *net; 1247 SKB_DR(reason); 1248 int lifetime; 1249 int optlen; 1250 1251 __u8 *opt = (__u8 *)(ra_msg + 1); 1252 1253 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) - 1254 sizeof(struct ra_msg); 1255 1256 ND_PRINTK(2, info, 1257 "RA: %s, dev: %s\n", 1258 __func__, skb->dev->name); 1259 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1260 ND_PRINTK(2, warn, "RA: source address is not link-local\n"); 1261 return reason; 1262 } 1263 if (optlen < 0) 1264 return SKB_DROP_REASON_PKT_TOO_SMALL; 1265 1266#ifdef CONFIG_IPV6_NDISC_NODETYPE 1267 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) { 1268 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n"); 1269 return reason; 1270 } 1271#endif 1272 1273 in6_dev = __in6_dev_get(skb->dev); 1274 if (!in6_dev) { 1275 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n", 1276 skb->dev->name); 1277 return reason; 1278 } 1279 1280 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) 1281 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1282 1283 if (!ipv6_accept_ra(in6_dev)) { 1284 ND_PRINTK(2, info, 1285 "RA: %s, did not accept ra for dev: %s\n", 1286 __func__, skb->dev->name); 1287 goto skip_linkparms; 1288 } 1289 1290#ifdef CONFIG_IPV6_NDISC_NODETYPE 1291 /* skip link-specific parameters from interior routers */ 1292 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1293 ND_PRINTK(2, info, 1294 "RA: %s, nodetype is NODEFAULT, dev: %s\n", 1295 __func__, skb->dev->name); 1296 goto skip_linkparms; 1297 } 1298#endif 1299 1300 if (in6_dev->if_flags & IF_RS_SENT) { 1301 /* 1302 * flag that an RA was received after an RS was sent 1303 * out on this interface. 1304 */ 1305 in6_dev->if_flags |= IF_RA_RCVD; 1306 } 1307 1308 /* 1309 * Remember the managed/otherconf flags from most recently 1310 * received RA message (RFC 2462) -- yoshfuji 1311 */ 1312 old_if_flags = in6_dev->if_flags; 1313 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED | 1314 IF_RA_OTHERCONF)) | 1315 (ra_msg->icmph.icmp6_addrconf_managed ? 1316 IF_RA_MANAGED : 0) | 1317 (ra_msg->icmph.icmp6_addrconf_other ? 1318 IF_RA_OTHERCONF : 0); 1319 1320 if (old_if_flags != in6_dev->if_flags) 1321 send_ifinfo_notify = true; 1322 1323 if (!READ_ONCE(in6_dev->cnf.accept_ra_defrtr)) { 1324 ND_PRINTK(2, info, 1325 "RA: %s, defrtr is false for dev: %s\n", 1326 __func__, skb->dev->name); 1327 goto skip_defrtr; 1328 } 1329 1330 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); 1331 if (lifetime != 0 && 1332 lifetime < READ_ONCE(in6_dev->cnf.accept_ra_min_lft)) { 1333 ND_PRINTK(2, info, 1334 "RA: router lifetime (%ds) is too short: %s\n", 1335 lifetime, skb->dev->name); 1336 goto skip_defrtr; 1337 } 1338 1339 /* Do not accept RA with source-addr found on local machine unless 1340 * accept_ra_from_local is set to true. 1341 */ 1342 net = dev_net(in6_dev->dev); 1343 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) && 1344 ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) { 1345 ND_PRINTK(2, info, 1346 "RA from local address detected on dev: %s: default router ignored\n", 1347 skb->dev->name); 1348 goto skip_defrtr; 1349 } 1350 1351#ifdef CONFIG_IPV6_ROUTER_PREF 1352 pref = ra_msg->icmph.icmp6_router_pref; 1353 /* 10b is handled as if it were 00b (medium) */ 1354 if (pref == ICMPV6_ROUTER_PREF_INVALID || 1355 !READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref)) 1356 pref = ICMPV6_ROUTER_PREF_MEDIUM; 1357#endif 1358 /* routes added from RAs do not use nexthop objects */ 1359 rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev); 1360 if (rt) { 1361 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6, 1362 rt->fib6_nh->fib_nh_dev, NULL, 1363 &ipv6_hdr(skb)->saddr); 1364 if (!neigh) { 1365 ND_PRINTK(0, err, 1366 "RA: %s got default router without neighbour\n", 1367 __func__); 1368 fib6_info_release(rt); 1369 return reason; 1370 } 1371 } 1372 /* Set default route metric as specified by user */ 1373 defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric; 1374 /* delete the route if lifetime is 0 or if metric needs change */ 1375 if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) { 1376 ip6_del_rt(net, rt, false); 1377 rt = NULL; 1378 } 1379 1380 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n", 1381 rt, lifetime, defrtr_usr_metric, skb->dev->name); 1382 if (!rt && lifetime) { 1383 ND_PRINTK(3, info, "RA: adding default router\n"); 1384 1385 if (neigh) 1386 neigh_release(neigh); 1387 1388 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr, 1389 skb->dev, pref, defrtr_usr_metric, 1390 lifetime); 1391 if (!rt) { 1392 ND_PRINTK(0, err, 1393 "RA: %s failed to add default route\n", 1394 __func__); 1395 return reason; 1396 } 1397 1398 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6, 1399 rt->fib6_nh->fib_nh_dev, NULL, 1400 &ipv6_hdr(skb)->saddr); 1401 if (!neigh) { 1402 ND_PRINTK(0, err, 1403 "RA: %s got default router without neighbour\n", 1404 __func__); 1405 fib6_info_release(rt); 1406 return reason; 1407 } 1408 neigh->flags |= NTF_ROUTER; 1409 } else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) { 1410 struct nl_info nlinfo = { 1411 .nl_net = net, 1412 }; 1413 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 1414 inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_REPLACE); 1415 } 1416 1417 if (rt) { 1418 table = rt->fib6_table; 1419 spin_lock_bh(&table->tb6_lock); 1420 1421 fib6_set_expires(rt, jiffies + (HZ * lifetime)); 1422 fib6_add_gc_list(rt); 1423 1424 spin_unlock_bh(&table->tb6_lock); 1425 } 1426 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) < 256 && 1427 ra_msg->icmph.icmp6_hop_limit) { 1428 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) <= 1429 ra_msg->icmph.icmp6_hop_limit) { 1430 WRITE_ONCE(in6_dev->cnf.hop_limit, 1431 ra_msg->icmph.icmp6_hop_limit); 1432 fib6_metric_set(rt, RTAX_HOPLIMIT, 1433 ra_msg->icmph.icmp6_hop_limit); 1434 } else { 1435 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n"); 1436 } 1437 } 1438 1439skip_defrtr: 1440 1441 /* 1442 * Update Reachable Time and Retrans Timer 1443 */ 1444 1445 if (in6_dev->nd_parms) { 1446 unsigned long rtime = ntohl(ra_msg->retrans_timer); 1447 1448 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) { 1449 rtime = (rtime*HZ)/1000; 1450 if (rtime < HZ/100) 1451 rtime = HZ/100; 1452 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime); 1453 in6_dev->tstamp = jiffies; 1454 send_ifinfo_notify = true; 1455 } 1456 1457 rtime = ntohl(ra_msg->reachable_time); 1458 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) { 1459 rtime = (rtime*HZ)/1000; 1460 1461 if (rtime < HZ/10) 1462 rtime = HZ/10; 1463 1464 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) { 1465 NEIGH_VAR_SET(in6_dev->nd_parms, 1466 BASE_REACHABLE_TIME, rtime); 1467 NEIGH_VAR_SET(in6_dev->nd_parms, 1468 GC_STALETIME, 3 * rtime); 1469 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime); 1470 in6_dev->tstamp = jiffies; 1471 send_ifinfo_notify = true; 1472 } 1473 } 1474 } 1475 1476skip_linkparms: 1477 1478 /* 1479 * Process options. 1480 */ 1481 1482 if (!neigh) 1483 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr, 1484 skb->dev, 1); 1485 if (neigh) { 1486 u8 *lladdr = NULL; 1487 if (ndopts.nd_opts_src_lladdr) { 1488 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1489 skb->dev); 1490 if (!lladdr) { 1491 ND_PRINTK(2, warn, 1492 "RA: invalid link-layer address length\n"); 1493 goto out; 1494 } 1495 } 1496 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE, 1497 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1498 NEIGH_UPDATE_F_OVERRIDE| 1499 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1500 NEIGH_UPDATE_F_ISROUTER, 1501 NDISC_ROUTER_ADVERTISEMENT, &ndopts); 1502 reason = SKB_CONSUMED; 1503 } 1504 1505 if (!ipv6_accept_ra(in6_dev)) { 1506 ND_PRINTK(2, info, 1507 "RA: %s, accept_ra is false for dev: %s\n", 1508 __func__, skb->dev->name); 1509 goto out; 1510 } 1511 1512#ifdef CONFIG_IPV6_ROUTE_INFO 1513 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) && 1514 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, 1515 in6_dev->dev, 0)) { 1516 ND_PRINTK(2, info, 1517 "RA from local address detected on dev: %s: router info ignored.\n", 1518 skb->dev->name); 1519 goto skip_routeinfo; 1520 } 1521 1522 if (READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref) && ndopts.nd_opts_ri) { 1523 struct nd_opt_hdr *p; 1524 for (p = ndopts.nd_opts_ri; 1525 p; 1526 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) { 1527 struct route_info *ri = (struct route_info *)p; 1528#ifdef CONFIG_IPV6_NDISC_NODETYPE 1529 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT && 1530 ri->prefix_len == 0) 1531 continue; 1532#endif 1533 if (ri->prefix_len == 0 && 1534 !READ_ONCE(in6_dev->cnf.accept_ra_defrtr)) 1535 continue; 1536 if (ri->lifetime != 0 && 1537 ntohl(ri->lifetime) < READ_ONCE(in6_dev->cnf.accept_ra_min_lft)) 1538 continue; 1539 if (ri->prefix_len < READ_ONCE(in6_dev->cnf.accept_ra_rt_info_min_plen)) 1540 continue; 1541 if (ri->prefix_len > READ_ONCE(in6_dev->cnf.accept_ra_rt_info_max_plen)) 1542 continue; 1543 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3, 1544 &ipv6_hdr(skb)->saddr); 1545 } 1546 } 1547 1548skip_routeinfo: 1549#endif 1550 1551#ifdef CONFIG_IPV6_NDISC_NODETYPE 1552 /* skip link-specific ndopts from interior routers */ 1553 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1554 ND_PRINTK(2, info, 1555 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n", 1556 __func__, skb->dev->name); 1557 goto out; 1558 } 1559#endif 1560 1561 if (READ_ONCE(in6_dev->cnf.accept_ra_pinfo) && ndopts.nd_opts_pi) { 1562 struct nd_opt_hdr *p; 1563 for (p = ndopts.nd_opts_pi; 1564 p; 1565 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) { 1566 addrconf_prefix_rcv(skb->dev, (u8 *)p, 1567 (p->nd_opt_len) << 3, 1568 ndopts.nd_opts_src_lladdr != NULL); 1569 } 1570 } 1571 1572 if (ndopts.nd_opts_mtu && READ_ONCE(in6_dev->cnf.accept_ra_mtu)) { 1573 __be32 n; 1574 u32 mtu; 1575 1576 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); 1577 mtu = ntohl(n); 1578 1579 if (in6_dev->ra_mtu != mtu) { 1580 in6_dev->ra_mtu = mtu; 1581 send_ifinfo_notify = true; 1582 } 1583 1584 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { 1585 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu); 1586 } else if (READ_ONCE(in6_dev->cnf.mtu6) != mtu) { 1587 WRITE_ONCE(in6_dev->cnf.mtu6, mtu); 1588 fib6_metric_set(rt, RTAX_MTU, mtu); 1589 rt6_mtu_change(skb->dev, mtu); 1590 } 1591 } 1592 1593 if (ndopts.nd_useropts) { 1594 struct nd_opt_hdr *p; 1595 for (p = ndopts.nd_useropts; 1596 p; 1597 p = ndisc_next_useropt(skb->dev, p, 1598 ndopts.nd_useropts_end)) { 1599 ndisc_ra_useropt(skb, p); 1600 } 1601 } 1602 1603 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { 1604 ND_PRINTK(2, warn, "RA: invalid RA options\n"); 1605 } 1606out: 1607 /* Send a notify if RA changed managed/otherconf flags or 1608 * timer settings or ra_mtu value 1609 */ 1610 if (send_ifinfo_notify) 1611 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1612 1613 fib6_info_release(rt); 1614 if (neigh) 1615 neigh_release(neigh); 1616 return reason; 1617} 1618 1619static enum skb_drop_reason ndisc_redirect_rcv(struct sk_buff *skb) 1620{ 1621 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb); 1622 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 1623 offsetof(struct rd_msg, opt)); 1624 struct ndisc_options ndopts; 1625 SKB_DR(reason); 1626 u8 *hdr; 1627 1628#ifdef CONFIG_IPV6_NDISC_NODETYPE 1629 switch (skb->ndisc_nodetype) { 1630 case NDISC_NODETYPE_HOST: 1631 case NDISC_NODETYPE_NODEFAULT: 1632 ND_PRINTK(2, warn, 1633 "Redirect: from host or unauthorized router\n"); 1634 return reason; 1635 } 1636#endif 1637 1638 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1639 ND_PRINTK(2, warn, 1640 "Redirect: source address is not link-local\n"); 1641 return reason; 1642 } 1643 1644 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts)) 1645 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1646 1647 if (!ndopts.nd_opts_rh) { 1648 ip6_redirect_no_header(skb, dev_net(skb->dev), 1649 skb->dev->ifindex); 1650 return reason; 1651 } 1652 1653 hdr = (u8 *)ndopts.nd_opts_rh; 1654 hdr += 8; 1655 if (!pskb_pull(skb, hdr - skb_transport_header(skb))) 1656 return SKB_DROP_REASON_PKT_TOO_SMALL; 1657 1658 return icmpv6_notify(skb, NDISC_REDIRECT, 0, 0); 1659} 1660 1661static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb, 1662 struct sk_buff *orig_skb, 1663 int rd_len) 1664{ 1665 u8 *opt = skb_put(skb, rd_len); 1666 1667 memset(opt, 0, 8); 1668 *(opt++) = ND_OPT_REDIRECT_HDR; 1669 *(opt++) = (rd_len >> 3); 1670 opt += 6; 1671 1672 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt, 1673 rd_len - 8); 1674} 1675 1676void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target) 1677{ 1678 struct net_device *dev = skb->dev; 1679 struct net *net = dev_net(dev); 1680 struct sock *sk = net->ipv6.ndisc_sk; 1681 int optlen = 0; 1682 struct inet_peer *peer; 1683 struct sk_buff *buff; 1684 struct rd_msg *msg; 1685 struct in6_addr saddr_buf; 1686 struct rt6_info *rt; 1687 struct dst_entry *dst; 1688 struct flowi6 fl6; 1689 int rd_len; 1690 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL, 1691 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL; 1692 bool ret; 1693 1694 if (netif_is_l3_master(skb->dev)) { 1695 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 1696 if (!dev) 1697 return; 1698 } 1699 1700 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) { 1701 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n", 1702 dev->name); 1703 return; 1704 } 1705 1706 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) && 1707 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1708 ND_PRINTK(2, warn, 1709 "Redirect: target address is not link-local unicast\n"); 1710 return; 1711 } 1712 1713 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT, 1714 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex); 1715 1716 dst = ip6_route_output(net, NULL, &fl6); 1717 if (dst->error) { 1718 dst_release(dst); 1719 return; 1720 } 1721 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); 1722 if (IS_ERR(dst)) 1723 return; 1724 1725 rt = (struct rt6_info *) dst; 1726 1727 if (rt->rt6i_flags & RTF_GATEWAY) { 1728 ND_PRINTK(2, warn, 1729 "Redirect: destination is not a neighbour\n"); 1730 goto release; 1731 } 1732 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1); 1733 ret = inet_peer_xrlim_allow(peer, 1*HZ); 1734 if (peer) 1735 inet_putpeer(peer); 1736 if (!ret) 1737 goto release; 1738 1739 if (dev->addr_len) { 1740 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target); 1741 if (!neigh) { 1742 ND_PRINTK(2, warn, 1743 "Redirect: no neigh for target address\n"); 1744 goto release; 1745 } 1746 1747 read_lock_bh(&neigh->lock); 1748 if (neigh->nud_state & NUD_VALID) { 1749 memcpy(ha_buf, neigh->ha, dev->addr_len); 1750 read_unlock_bh(&neigh->lock); 1751 ha = ha_buf; 1752 optlen += ndisc_redirect_opt_addr_space(dev, neigh, 1753 ops_data_buf, 1754 &ops_data); 1755 } else 1756 read_unlock_bh(&neigh->lock); 1757 1758 neigh_release(neigh); 1759 } 1760 1761 rd_len = min_t(unsigned int, 1762 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen, 1763 skb->len + 8); 1764 rd_len &= ~0x7; 1765 optlen += rd_len; 1766 1767 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 1768 if (!buff) 1769 goto release; 1770 1771 msg = skb_put(buff, sizeof(*msg)); 1772 *msg = (struct rd_msg) { 1773 .icmph = { 1774 .icmp6_type = NDISC_REDIRECT, 1775 }, 1776 .target = *target, 1777 .dest = ipv6_hdr(skb)->daddr, 1778 }; 1779 1780 /* 1781 * include target_address option 1782 */ 1783 1784 if (ha) 1785 ndisc_fill_redirect_addr_option(buff, ha, ops_data); 1786 1787 /* 1788 * build redirect option and copy skb over to the new packet. 1789 */ 1790 1791 if (rd_len) 1792 ndisc_fill_redirect_hdr_option(buff, skb, rd_len); 1793 1794 skb_dst_set(buff, dst); 1795 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf); 1796 return; 1797 1798release: 1799 dst_release(dst); 1800} 1801 1802static void pndisc_redo(struct sk_buff *skb) 1803{ 1804 enum skb_drop_reason reason = ndisc_recv_ns(skb); 1805 1806 kfree_skb_reason(skb, reason); 1807} 1808 1809static int ndisc_is_multicast(const void *pkey) 1810{ 1811 return ipv6_addr_is_multicast((struct in6_addr *)pkey); 1812} 1813 1814static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb) 1815{ 1816 struct inet6_dev *idev = __in6_dev_get(skb->dev); 1817 1818 if (!idev) 1819 return true; 1820 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED && 1821 READ_ONCE(idev->cnf.suppress_frag_ndisc)) { 1822 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n"); 1823 return true; 1824 } 1825 return false; 1826} 1827 1828enum skb_drop_reason ndisc_rcv(struct sk_buff *skb) 1829{ 1830 struct nd_msg *msg; 1831 SKB_DR(reason); 1832 1833 if (ndisc_suppress_frag_ndisc(skb)) 1834 return SKB_DROP_REASON_IPV6_NDISC_FRAG; 1835 1836 if (skb_linearize(skb)) 1837 return SKB_DROP_REASON_NOMEM; 1838 1839 msg = (struct nd_msg *)skb_transport_header(skb); 1840 1841 __skb_push(skb, skb->data - skb_transport_header(skb)); 1842 1843 if (ipv6_hdr(skb)->hop_limit != 255) { 1844 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n", 1845 ipv6_hdr(skb)->hop_limit); 1846 return SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT; 1847 } 1848 1849 if (msg->icmph.icmp6_code != 0) { 1850 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n", 1851 msg->icmph.icmp6_code); 1852 return SKB_DROP_REASON_IPV6_NDISC_BAD_CODE; 1853 } 1854 1855 switch (msg->icmph.icmp6_type) { 1856 case NDISC_NEIGHBOUR_SOLICITATION: 1857 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 1858 reason = ndisc_recv_ns(skb); 1859 break; 1860 1861 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1862 reason = ndisc_recv_na(skb); 1863 break; 1864 1865 case NDISC_ROUTER_SOLICITATION: 1866 reason = ndisc_recv_rs(skb); 1867 break; 1868 1869 case NDISC_ROUTER_ADVERTISEMENT: 1870 reason = ndisc_router_discovery(skb); 1871 break; 1872 1873 case NDISC_REDIRECT: 1874 reason = ndisc_redirect_rcv(skb); 1875 break; 1876 } 1877 1878 return reason; 1879} 1880 1881static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1882{ 1883 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1884 struct netdev_notifier_change_info *change_info; 1885 struct net *net = dev_net(dev); 1886 struct inet6_dev *idev; 1887 bool evict_nocarrier; 1888 1889 switch (event) { 1890 case NETDEV_CHANGEADDR: 1891 neigh_changeaddr(&nd_tbl, dev); 1892 fib6_run_gc(0, net, false); 1893 fallthrough; 1894 case NETDEV_UP: 1895 idev = in6_dev_get(dev); 1896 if (!idev) 1897 break; 1898 if (READ_ONCE(idev->cnf.ndisc_notify) || 1899 READ_ONCE(net->ipv6.devconf_all->ndisc_notify)) 1900 ndisc_send_unsol_na(dev); 1901 in6_dev_put(idev); 1902 break; 1903 case NETDEV_CHANGE: 1904 idev = in6_dev_get(dev); 1905 if (!idev) 1906 evict_nocarrier = true; 1907 else { 1908 evict_nocarrier = READ_ONCE(idev->cnf.ndisc_evict_nocarrier) && 1909 READ_ONCE(net->ipv6.devconf_all->ndisc_evict_nocarrier); 1910 in6_dev_put(idev); 1911 } 1912 1913 change_info = ptr; 1914 if (change_info->flags_changed & IFF_NOARP) 1915 neigh_changeaddr(&nd_tbl, dev); 1916 if (evict_nocarrier && !netif_carrier_ok(dev)) 1917 neigh_carrier_down(&nd_tbl, dev); 1918 break; 1919 case NETDEV_DOWN: 1920 neigh_ifdown(&nd_tbl, dev); 1921 fib6_run_gc(0, net, false); 1922 break; 1923 case NETDEV_NOTIFY_PEERS: 1924 ndisc_send_unsol_na(dev); 1925 break; 1926 default: 1927 break; 1928 } 1929 1930 return NOTIFY_DONE; 1931} 1932 1933static struct notifier_block ndisc_netdev_notifier = { 1934 .notifier_call = ndisc_netdev_event, 1935 .priority = ADDRCONF_NOTIFY_PRIORITY - 5, 1936}; 1937 1938#ifdef CONFIG_SYSCTL 1939static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl, 1940 const char *func, const char *dev_name) 1941{ 1942 static char warncomm[TASK_COMM_LEN]; 1943 static int warned; 1944 if (strcmp(warncomm, current->comm) && warned < 5) { 1945 strcpy(warncomm, current->comm); 1946 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n", 1947 warncomm, func, 1948 dev_name, ctl->procname, 1949 dev_name, ctl->procname); 1950 warned++; 1951 } 1952} 1953 1954int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer, 1955 size_t *lenp, loff_t *ppos) 1956{ 1957 struct net_device *dev = ctl->extra1; 1958 struct inet6_dev *idev; 1959 int ret; 1960 1961 if ((strcmp(ctl->procname, "retrans_time") == 0) || 1962 (strcmp(ctl->procname, "base_reachable_time") == 0)) 1963 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default"); 1964 1965 if (strcmp(ctl->procname, "retrans_time") == 0) 1966 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos); 1967 1968 else if (strcmp(ctl->procname, "base_reachable_time") == 0) 1969 ret = neigh_proc_dointvec_jiffies(ctl, write, 1970 buffer, lenp, ppos); 1971 1972 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) || 1973 (strcmp(ctl->procname, "base_reachable_time_ms") == 0)) 1974 ret = neigh_proc_dointvec_ms_jiffies(ctl, write, 1975 buffer, lenp, ppos); 1976 else 1977 ret = -1; 1978 1979 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) { 1980 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)) 1981 idev->nd_parms->reachable_time = 1982 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)); 1983 WRITE_ONCE(idev->tstamp, jiffies); 1984 inet6_ifinfo_notify(RTM_NEWLINK, idev); 1985 in6_dev_put(idev); 1986 } 1987 return ret; 1988} 1989 1990 1991#endif 1992 1993static int __net_init ndisc_net_init(struct net *net) 1994{ 1995 struct ipv6_pinfo *np; 1996 struct sock *sk; 1997 int err; 1998 1999 err = inet_ctl_sock_create(&sk, PF_INET6, 2000 SOCK_RAW, IPPROTO_ICMPV6, net); 2001 if (err < 0) { 2002 ND_PRINTK(0, err, 2003 "NDISC: Failed to initialize the control socket (err %d)\n", 2004 err); 2005 return err; 2006 } 2007 2008 net->ipv6.ndisc_sk = sk; 2009 2010 np = inet6_sk(sk); 2011 np->hop_limit = 255; 2012 /* Do not loopback ndisc messages */ 2013 inet6_clear_bit(MC6_LOOP, sk); 2014 2015 return 0; 2016} 2017 2018static void __net_exit ndisc_net_exit(struct net *net) 2019{ 2020 inet_ctl_sock_destroy(net->ipv6.ndisc_sk); 2021} 2022 2023static struct pernet_operations ndisc_net_ops = { 2024 .init = ndisc_net_init, 2025 .exit = ndisc_net_exit, 2026}; 2027 2028int __init ndisc_init(void) 2029{ 2030 int err; 2031 2032 err = register_pernet_subsys(&ndisc_net_ops); 2033 if (err) 2034 return err; 2035 /* 2036 * Initialize the neighbour table 2037 */ 2038 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl); 2039 2040#ifdef CONFIG_SYSCTL 2041 err = neigh_sysctl_register(NULL, &nd_tbl.parms, 2042 ndisc_ifinfo_sysctl_change); 2043 if (err) 2044 goto out_unregister_pernet; 2045out: 2046#endif 2047 return err; 2048 2049#ifdef CONFIG_SYSCTL 2050out_unregister_pernet: 2051 unregister_pernet_subsys(&ndisc_net_ops); 2052 goto out; 2053#endif 2054} 2055 2056int __init ndisc_late_init(void) 2057{ 2058 return register_netdevice_notifier(&ndisc_netdev_notifier); 2059} 2060 2061void ndisc_late_cleanup(void) 2062{ 2063 unregister_netdevice_notifier(&ndisc_netdev_notifier); 2064} 2065 2066void ndisc_cleanup(void) 2067{ 2068#ifdef CONFIG_SYSCTL 2069 neigh_sysctl_unregister(&nd_tbl.parms); 2070#endif 2071 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl); 2072 unregister_pernet_subsys(&ndisc_net_ops); 2073} 2074