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 72 static u32 ndisc_hash(const void *pkey, 73 const struct net_device *dev, 74 __u32 *hash_rnd); 75 static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey); 76 static bool ndisc_allow_add(const struct net_device *dev, 77 struct netlink_ext_ack *extack); 78 static int ndisc_constructor(struct neighbour *neigh); 79 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb); 80 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb); 81 static int pndisc_constructor(struct pneigh_entry *n); 82 static void pndisc_destructor(struct pneigh_entry *n); 83 static void pndisc_redo(struct sk_buff *skb); 84 static int ndisc_is_multicast(const void *pkey); 85 86 static 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 94 static 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 }; 101 102 103 static const struct neigh_ops ndisc_direct_ops = { 104 .family = AF_INET6, 105 .output = neigh_direct_output, 106 .connected_output = neigh_direct_output, 107 }; 108 109 struct 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 }; 144 EXPORT_SYMBOL_GPL(nd_tbl); 145 146 void __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 } 166 EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option); 167 168 static 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 } 175 176 static 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 } 183 184 static 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 } 196 197 static 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_6CO || 204 opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL || 205 opt->nd_opt_type == ND_OPT_PREF64; 206 } 207 208 static 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 } 219 220 struct 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 bool unknown = false; 231 int l; 232 if (opt_len < sizeof(struct nd_opt_hdr)) 233 return NULL; 234 l = nd_opt->nd_opt_len << 3; 235 if (opt_len < l || l == 0) 236 return NULL; 237 if (ndisc_ops_parse_options(dev, nd_opt, ndopts)) 238 goto next_opt; 239 switch (nd_opt->nd_opt_type) { 240 case ND_OPT_SOURCE_LL_ADDR: 241 case ND_OPT_TARGET_LL_ADDR: 242 case ND_OPT_MTU: 243 case ND_OPT_NONCE: 244 case ND_OPT_REDIRECT_HDR: 245 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { 246 net_dbg_ratelimited("%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 unknown = true; 266 } 267 if (ndisc_is_useropt(dev, nd_opt)) { 268 ndopts->nd_useropts_end = nd_opt; 269 if (!ndopts->nd_useropts) 270 ndopts->nd_useropts = nd_opt; 271 } else if (unknown) { 272 /* 273 * Unknown options must be silently ignored, 274 * to accommodate future extension to the 275 * protocol. 276 */ 277 net_dbg_ratelimited("%s: ignored unsupported option; type=%d, len=%d\n", 278 __func__, nd_opt->nd_opt_type, nd_opt->nd_opt_len); 279 } 280 next_opt: 281 opt_len -= l; 282 nd_opt = ((void *)nd_opt) + l; 283 } 284 return ndopts; 285 } 286 287 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir) 288 { 289 switch (dev->type) { 290 case ARPHRD_ETHER: 291 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */ 292 case ARPHRD_FDDI: 293 ipv6_eth_mc_map(addr, buf); 294 return 0; 295 case ARPHRD_ARCNET: 296 ipv6_arcnet_mc_map(addr, buf); 297 return 0; 298 case ARPHRD_INFINIBAND: 299 ipv6_ib_mc_map(addr, dev->broadcast, buf); 300 return 0; 301 case ARPHRD_IPGRE: 302 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf); 303 default: 304 if (dir) { 305 memcpy(buf, dev->broadcast, dev->addr_len); 306 return 0; 307 } 308 } 309 return -EINVAL; 310 } 311 EXPORT_SYMBOL(ndisc_mc_map); 312 313 static u32 ndisc_hash(const void *pkey, 314 const struct net_device *dev, 315 __u32 *hash_rnd) 316 { 317 return ndisc_hashfn(pkey, dev, hash_rnd); 318 } 319 320 static bool ndisc_key_eq(const struct neighbour *n, const void *pkey) 321 { 322 return neigh_key_eq128(n, pkey); 323 } 324 325 static int ndisc_constructor(struct neighbour *neigh) 326 { 327 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key; 328 struct net_device *dev = neigh->dev; 329 struct inet6_dev *in6_dev; 330 struct neigh_parms *parms; 331 bool is_multicast = ipv6_addr_is_multicast(addr); 332 333 in6_dev = in6_dev_get(dev); 334 if (!in6_dev) { 335 return -EINVAL; 336 } 337 338 parms = in6_dev->nd_parms; 339 __neigh_parms_put(neigh->parms); 340 neigh->parms = neigh_parms_clone(parms); 341 342 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST; 343 if (!dev->header_ops) { 344 neigh->nud_state = NUD_NOARP; 345 neigh->ops = &ndisc_direct_ops; 346 neigh->output = neigh_direct_output; 347 } else { 348 if (is_multicast) { 349 neigh->nud_state = NUD_NOARP; 350 ndisc_mc_map(addr, neigh->ha, dev, 1); 351 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { 352 neigh->nud_state = NUD_NOARP; 353 memcpy(neigh->ha, dev->dev_addr, dev->addr_len); 354 if (dev->flags&IFF_LOOPBACK) 355 neigh->type = RTN_LOCAL; 356 } else if (dev->flags&IFF_POINTOPOINT) { 357 neigh->nud_state = NUD_NOARP; 358 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 359 } 360 if (dev->header_ops->cache) 361 neigh->ops = &ndisc_hh_ops; 362 else 363 neigh->ops = &ndisc_generic_ops; 364 if (neigh->nud_state&NUD_VALID) 365 neigh->output = neigh->ops->connected_output; 366 else 367 neigh->output = neigh->ops->output; 368 } 369 in6_dev_put(in6_dev); 370 return 0; 371 } 372 373 static int pndisc_constructor(struct pneigh_entry *n) 374 { 375 struct in6_addr *addr = (struct in6_addr *)&n->key; 376 struct net_device *dev = n->dev; 377 struct in6_addr maddr; 378 379 if (!dev) 380 return -EINVAL; 381 382 addrconf_addr_solict_mult(addr, &maddr); 383 return ipv6_dev_mc_inc(dev, &maddr); 384 } 385 386 static void pndisc_destructor(struct pneigh_entry *n) 387 { 388 struct in6_addr *addr = (struct in6_addr *)&n->key; 389 struct net_device *dev = n->dev; 390 struct in6_addr maddr; 391 392 if (!dev) 393 return; 394 395 addrconf_addr_solict_mult(addr, &maddr); 396 ipv6_dev_mc_dec(dev, &maddr); 397 } 398 399 /* called with rtnl held */ 400 static bool ndisc_allow_add(const struct net_device *dev, 401 struct netlink_ext_ack *extack) 402 { 403 struct inet6_dev *idev = __in6_dev_get(dev); 404 405 if (!idev || idev->cnf.disable_ipv6) { 406 NL_SET_ERR_MSG(extack, "IPv6 is disabled on this device"); 407 return false; 408 } 409 410 return true; 411 } 412 413 static struct sk_buff *ndisc_alloc_skb(struct net_device *dev, 414 int len) 415 { 416 int hlen = LL_RESERVED_SPACE(dev); 417 int tlen = dev->needed_tailroom; 418 struct sk_buff *skb; 419 420 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC); 421 if (!skb) 422 return NULL; 423 424 skb->protocol = htons(ETH_P_IPV6); 425 skb->dev = dev; 426 427 skb_reserve(skb, hlen + sizeof(struct ipv6hdr)); 428 skb_reset_transport_header(skb); 429 430 /* Manually assign socket ownership as we avoid calling 431 * sock_alloc_send_pskb() to bypass wmem buffer limits 432 */ 433 rcu_read_lock(); 434 skb_set_owner_w(skb, dev_net_rcu(dev)->ipv6.ndisc_sk); 435 rcu_read_unlock(); 436 437 return skb; 438 } 439 440 static void ip6_nd_hdr(struct sk_buff *skb, 441 const struct in6_addr *saddr, 442 const struct in6_addr *daddr, 443 int hop_limit, int len) 444 { 445 struct ipv6hdr *hdr; 446 struct inet6_dev *idev; 447 unsigned tclass; 448 449 rcu_read_lock(); 450 idev = __in6_dev_get(skb->dev); 451 tclass = idev ? READ_ONCE(idev->cnf.ndisc_tclass) : 0; 452 rcu_read_unlock(); 453 454 skb_push(skb, sizeof(*hdr)); 455 skb_reset_network_header(skb); 456 hdr = ipv6_hdr(skb); 457 458 ip6_flow_hdr(hdr, tclass, 0); 459 460 hdr->payload_len = htons(len); 461 hdr->nexthdr = IPPROTO_ICMPV6; 462 hdr->hop_limit = hop_limit; 463 464 hdr->saddr = *saddr; 465 hdr->daddr = *daddr; 466 } 467 468 void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr, 469 const struct in6_addr *saddr) 470 { 471 struct icmp6hdr *icmp6h = icmp6_hdr(skb); 472 struct dst_entry *dst = skb_dst(skb); 473 struct net_device *dev; 474 struct inet6_dev *idev; 475 struct net *net; 476 struct sock *sk; 477 int err; 478 u8 type; 479 480 type = icmp6h->icmp6_type; 481 482 rcu_read_lock(); 483 484 net = dev_net_rcu(skb->dev); 485 sk = net->ipv6.ndisc_sk; 486 if (!dst) { 487 struct flowi6 fl6; 488 int oif = skb->dev->ifindex; 489 490 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif); 491 dst = icmp6_dst_alloc(skb->dev, &fl6); 492 if (IS_ERR(dst)) { 493 rcu_read_unlock(); 494 kfree_skb(skb); 495 return; 496 } 497 498 skb_dst_set(skb, dst); 499 } 500 501 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len, 502 IPPROTO_ICMPV6, 503 csum_partial(icmp6h, 504 skb->len, 0)); 505 506 ip6_nd_hdr(skb, saddr, daddr, READ_ONCE(inet6_sk(sk)->hop_limit), skb->len); 507 508 dev = dst_dev(dst); 509 idev = __in6_dev_get(dev); 510 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS); 511 512 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, 513 net, sk, skb, NULL, dev, 514 dst_output); 515 if (!err) { 516 ICMP6MSGOUT_INC_STATS(net, idev, type); 517 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 518 } 519 520 rcu_read_unlock(); 521 } 522 EXPORT_SYMBOL(ndisc_send_skb); 523 524 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr, 525 const struct in6_addr *solicited_addr, 526 bool router, bool solicited, bool override, bool inc_opt) 527 { 528 struct sk_buff *skb; 529 struct in6_addr tmpaddr; 530 struct inet6_ifaddr *ifp; 531 const struct in6_addr *src_addr; 532 struct nd_msg *msg; 533 int optlen = 0; 534 535 /* for anycast or proxy, solicited_addr != src_addr */ 536 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1); 537 if (ifp) { 538 src_addr = solicited_addr; 539 if (ifp->flags & IFA_F_OPTIMISTIC) 540 override = false; 541 inc_opt |= READ_ONCE(ifp->idev->cnf.force_tllao); 542 in6_ifa_put(ifp); 543 } else { 544 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr, 545 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs, 546 &tmpaddr)) 547 return; 548 src_addr = &tmpaddr; 549 } 550 551 if (!dev->addr_len) 552 inc_opt = false; 553 if (inc_opt) 554 optlen += ndisc_opt_addr_space(dev, 555 NDISC_NEIGHBOUR_ADVERTISEMENT); 556 557 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 558 if (!skb) 559 return; 560 561 msg = skb_put(skb, sizeof(*msg)); 562 *msg = (struct nd_msg) { 563 .icmph = { 564 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT, 565 .icmp6_router = router, 566 .icmp6_solicited = solicited, 567 .icmp6_override = override, 568 }, 569 .target = *solicited_addr, 570 }; 571 572 if (inc_opt) 573 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, 574 dev->dev_addr, 575 NDISC_NEIGHBOUR_ADVERTISEMENT); 576 577 ndisc_send_skb(skb, daddr, src_addr); 578 } 579 580 static void ndisc_send_unsol_na(struct net_device *dev) 581 { 582 struct inet6_dev *idev; 583 struct inet6_ifaddr *ifa; 584 585 idev = in6_dev_get(dev); 586 if (!idev) 587 return; 588 589 read_lock_bh(&idev->lock); 590 list_for_each_entry(ifa, &idev->addr_list, if_list) { 591 /* skip tentative addresses until dad completes */ 592 if (ifa->flags & IFA_F_TENTATIVE && 593 !(ifa->flags & IFA_F_OPTIMISTIC)) 594 continue; 595 596 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr, 597 /*router=*/ !!idev->cnf.forwarding, 598 /*solicited=*/ false, /*override=*/ true, 599 /*inc_opt=*/ true); 600 } 601 read_unlock_bh(&idev->lock); 602 603 in6_dev_put(idev); 604 } 605 606 struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit, 607 const struct in6_addr *saddr, u64 nonce) 608 { 609 int inc_opt = dev->addr_len; 610 struct sk_buff *skb; 611 struct nd_msg *msg; 612 int optlen = 0; 613 614 if (!saddr) 615 return NULL; 616 617 if (ipv6_addr_any(saddr)) 618 inc_opt = false; 619 if (inc_opt) 620 optlen += ndisc_opt_addr_space(dev, 621 NDISC_NEIGHBOUR_SOLICITATION); 622 if (nonce != 0) 623 optlen += 8; 624 625 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 626 if (!skb) 627 return NULL; 628 629 msg = skb_put(skb, sizeof(*msg)); 630 *msg = (struct nd_msg) { 631 .icmph = { 632 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION, 633 }, 634 .target = *solicit, 635 }; 636 637 if (inc_opt) 638 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR, 639 dev->dev_addr, 640 NDISC_NEIGHBOUR_SOLICITATION); 641 if (nonce != 0) { 642 u8 *opt = skb_put(skb, 8); 643 644 opt[0] = ND_OPT_NONCE; 645 opt[1] = 8 >> 3; 646 memcpy(opt + 2, &nonce, 6); 647 } 648 649 return skb; 650 } 651 EXPORT_SYMBOL(ndisc_ns_create); 652 653 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit, 654 const struct in6_addr *daddr, const struct in6_addr *saddr, 655 u64 nonce) 656 { 657 struct in6_addr addr_buf; 658 struct sk_buff *skb; 659 660 if (!saddr) { 661 if (ipv6_get_lladdr(dev, &addr_buf, 662 (IFA_F_TENTATIVE | IFA_F_OPTIMISTIC))) 663 return; 664 saddr = &addr_buf; 665 } 666 667 skb = ndisc_ns_create(dev, solicit, saddr, nonce); 668 669 if (skb) 670 ndisc_send_skb(skb, daddr, saddr); 671 } 672 673 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr, 674 const struct in6_addr *daddr) 675 { 676 struct sk_buff *skb; 677 struct rs_msg *msg; 678 int send_sllao = dev->addr_len; 679 int optlen = 0; 680 681 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 682 /* 683 * According to section 2.2 of RFC 4429, we must not 684 * send router solicitations with a sllao from 685 * optimistic addresses, but we may send the solicitation 686 * if we don't include the sllao. So here we check 687 * if our address is optimistic, and if so, we 688 * suppress the inclusion of the sllao. 689 */ 690 if (send_sllao) { 691 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr, 692 dev, 1); 693 if (ifp) { 694 if (ifp->flags & IFA_F_OPTIMISTIC) { 695 send_sllao = 0; 696 } 697 in6_ifa_put(ifp); 698 } else { 699 send_sllao = 0; 700 } 701 } 702 #endif 703 if (send_sllao) 704 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION); 705 706 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 707 if (!skb) 708 return; 709 710 msg = skb_put(skb, sizeof(*msg)); 711 *msg = (struct rs_msg) { 712 .icmph = { 713 .icmp6_type = NDISC_ROUTER_SOLICITATION, 714 }, 715 }; 716 717 if (send_sllao) 718 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR, 719 dev->dev_addr, 720 NDISC_ROUTER_SOLICITATION); 721 722 ndisc_send_skb(skb, daddr, saddr); 723 } 724 725 726 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb) 727 { 728 /* 729 * "The sender MUST return an ICMP 730 * destination unreachable" 731 */ 732 dst_link_failure(skb); 733 kfree_skb(skb); 734 } 735 736 /* Called with locked neigh: either read or both */ 737 738 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb) 739 { 740 struct in6_addr *saddr = NULL; 741 struct in6_addr mcaddr; 742 struct net_device *dev = neigh->dev; 743 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key; 744 int probes = atomic_read(&neigh->probes); 745 746 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr, 747 dev, false, 1, 748 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) 749 saddr = &ipv6_hdr(skb)->saddr; 750 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES); 751 if (probes < 0) { 752 if (!(READ_ONCE(neigh->nud_state) & NUD_VALID)) { 753 net_dbg_ratelimited("%s: trying to ucast probe in NUD_INVALID: %pI6\n", 754 __func__, target); 755 } 756 ndisc_send_ns(dev, target, target, saddr, 0); 757 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) { 758 neigh_app_ns(neigh); 759 } else { 760 addrconf_addr_solict_mult(target, &mcaddr); 761 ndisc_send_ns(dev, target, &mcaddr, saddr, 0); 762 } 763 } 764 765 static int pndisc_is_router(const void *pkey, 766 struct net_device *dev) 767 { 768 struct pneigh_entry *n; 769 int ret = -1; 770 771 n = pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev); 772 if (n) 773 ret = !!(READ_ONCE(n->flags) & NTF_ROUTER); 774 775 return ret; 776 } 777 778 void 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 } 786 787 static 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 net_dbg_ratelimited("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 net_dbg_ratelimited("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 net_dbg_ratelimited("NS: invalid link-layer address length\n"); 830 return reason; 831 } 832 833 /* RFC2461 7.1.1: 834 * If the IP source address is the unspecified address, 835 * there MUST NOT be source link-layer address option 836 * in the message. 837 */ 838 if (dad) { 839 net_dbg_ratelimited("NS: bad DAD packet (link-layer address option)\n"); 840 return reason; 841 } 842 } 843 if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1) 844 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6); 845 846 inc = ipv6_addr_is_multicast(daddr); 847 848 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); 849 if (ifp) { 850 have_ifp: 851 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) { 852 if (dad) { 853 if (nonce != 0 && ifp->dad_nonce == nonce) { 854 u8 *np = (u8 *)&nonce; 855 /* Matching nonce if looped back */ 856 net_dbg_ratelimited("%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n", 857 ifp->idev->dev->name, &ifp->addr, np); 858 goto out; 859 } 860 /* 861 * We are colliding with another node 862 * who is doing DAD 863 * so fail our DAD process 864 */ 865 addrconf_dad_failure(skb, ifp); 866 return reason; 867 } else { 868 /* 869 * This is not a dad solicitation. 870 * If we are an optimistic node, 871 * we should respond. 872 * Otherwise, we should ignore it. 873 */ 874 if (!(ifp->flags & IFA_F_OPTIMISTIC)) 875 goto out; 876 } 877 } 878 879 idev = ifp->idev; 880 } else { 881 struct net *net = dev_net(dev); 882 883 /* perhaps an address on the master device */ 884 if (netif_is_l3_slave(dev)) { 885 struct net_device *mdev; 886 887 mdev = netdev_master_upper_dev_get_rcu(dev); 888 if (mdev) { 889 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1); 890 if (ifp) 891 goto have_ifp; 892 } 893 } 894 895 idev = in6_dev_get(dev); 896 if (!idev) { 897 /* XXX: count this drop? */ 898 return reason; 899 } 900 901 if (ipv6_chk_acast_addr(net, dev, &msg->target) || 902 (READ_ONCE(idev->cnf.forwarding) && 903 (READ_ONCE(net->ipv6.devconf_all->proxy_ndp) || 904 READ_ONCE(idev->cnf.proxy_ndp)) && 905 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) { 906 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) && 907 skb->pkt_type != PACKET_HOST && 908 inc && 909 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) { 910 /* 911 * for anycast or proxy, 912 * sender should delay its response 913 * by a random time between 0 and 914 * MAX_ANYCAST_DELAY_TIME seconds. 915 * (RFC2461) -- yoshfuji 916 */ 917 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC); 918 if (n) 919 pneigh_enqueue(&nd_tbl, idev->nd_parms, n); 920 goto out; 921 } 922 } else { 923 SKB_DR_SET(reason, IPV6_NDISC_NS_OTHERHOST); 924 goto out; 925 } 926 } 927 928 if (is_router < 0) 929 is_router = READ_ONCE(idev->cnf.forwarding); 930 931 if (dad) { 932 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target, 933 !!is_router, false, (ifp != NULL), true); 934 goto out; 935 } 936 937 if (inc) 938 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast); 939 else 940 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast); 941 942 /* 943 * update / create cache entry 944 * for the source address 945 */ 946 neigh = __neigh_lookup(&nd_tbl, saddr, dev, 947 !inc || lladdr || !dev->addr_len); 948 if (neigh) 949 ndisc_update(dev, neigh, lladdr, NUD_STALE, 950 NEIGH_UPDATE_F_WEAK_OVERRIDE| 951 NEIGH_UPDATE_F_OVERRIDE, 952 NDISC_NEIGHBOUR_SOLICITATION, &ndopts); 953 if (neigh || !dev->header_ops) { 954 ndisc_send_na(dev, saddr, &msg->target, !!is_router, 955 true, (ifp != NULL && inc), inc); 956 if (neigh) 957 neigh_release(neigh); 958 reason = SKB_CONSUMED; 959 } 960 961 out: 962 if (ifp) 963 in6_ifa_put(ifp); 964 else 965 in6_dev_put(idev); 966 return reason; 967 } 968 969 static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr) 970 { 971 struct inet6_dev *idev = __in6_dev_get(dev); 972 973 switch (READ_ONCE(idev->cnf.accept_untracked_na)) { 974 case 0: /* Don't accept untracked na (absent in neighbor cache) */ 975 return 0; 976 case 1: /* Create new entries from na if currently untracked */ 977 return 1; 978 case 2: /* Create new entries from untracked na only if saddr is in the 979 * same subnet as an address configured on the interface that 980 * received the na 981 */ 982 return !!ipv6_chk_prefix(saddr, dev); 983 default: 984 return 0; 985 } 986 } 987 988 static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb) 989 { 990 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 991 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 992 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 993 u8 *lladdr = NULL; 994 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 995 offsetof(struct nd_msg, opt)); 996 struct ndisc_options ndopts; 997 struct net_device *dev = skb->dev; 998 struct inet6_dev *idev = __in6_dev_get(dev); 999 struct inet6_ifaddr *ifp; 1000 struct neighbour *neigh; 1001 SKB_DR(reason); 1002 u8 new_state; 1003 1004 if (skb->len < sizeof(struct nd_msg)) 1005 return SKB_DROP_REASON_PKT_TOO_SMALL; 1006 1007 if (ipv6_addr_is_multicast(&msg->target)) { 1008 net_dbg_ratelimited("NA: target address is multicast\n"); 1009 return reason; 1010 } 1011 1012 if (ipv6_addr_is_multicast(daddr) && 1013 msg->icmph.icmp6_solicited) { 1014 net_dbg_ratelimited("NA: solicited NA is multicasted\n"); 1015 return reason; 1016 } 1017 1018 /* For some 802.11 wireless deployments (and possibly other networks), 1019 * there will be a NA proxy and unsolicitd packets are attacks 1020 * and thus should not be accepted. 1021 * drop_unsolicited_na takes precedence over accept_untracked_na 1022 */ 1023 if (!msg->icmph.icmp6_solicited && idev && 1024 READ_ONCE(idev->cnf.drop_unsolicited_na)) 1025 return reason; 1026 1027 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) 1028 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1029 1030 if (ndopts.nd_opts_tgt_lladdr) { 1031 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev); 1032 if (!lladdr) { 1033 net_dbg_ratelimited("NA: invalid link-layer address length\n"); 1034 return reason; 1035 } 1036 } 1037 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); 1038 if (ifp) { 1039 if (skb->pkt_type != PACKET_LOOPBACK 1040 && (ifp->flags & IFA_F_TENTATIVE)) { 1041 addrconf_dad_failure(skb, ifp); 1042 return reason; 1043 } 1044 /* What should we make now? The advertisement 1045 is invalid, but ndisc specs say nothing 1046 about it. It could be misconfiguration, or 1047 an smart proxy agent tries to help us :-) 1048 1049 We should not print the error if NA has been 1050 received from loopback - it is just our own 1051 unsolicited advertisement. 1052 */ 1053 if (skb->pkt_type != PACKET_LOOPBACK) 1054 net_warn_ratelimited("NA: %pM advertised our address %pI6c on %s!\n", 1055 eth_hdr(skb)->h_source, &ifp->addr, 1056 ifp->idev->dev->name); 1057 in6_ifa_put(ifp); 1058 return reason; 1059 } 1060 1061 neigh = neigh_lookup(&nd_tbl, &msg->target, dev); 1062 1063 /* RFC 9131 updates original Neighbour Discovery RFC 4861. 1064 * NAs with Target LL Address option without a corresponding 1065 * entry in the neighbour cache can now create a STALE neighbour 1066 * cache entry on routers. 1067 * 1068 * entry accept fwding solicited behaviour 1069 * ------- ------ ------ --------- ---------------------- 1070 * present X X 0 Set state to STALE 1071 * present X X 1 Set state to REACHABLE 1072 * absent 0 X X Do nothing 1073 * absent 1 0 X Do nothing 1074 * absent 1 1 X Add a new STALE entry 1075 * 1076 * Note that we don't do a (daddr == all-routers-mcast) check. 1077 */ 1078 new_state = msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE; 1079 if (!neigh && lladdr && idev && READ_ONCE(idev->cnf.forwarding)) { 1080 if (accept_untracked_na(dev, saddr)) { 1081 neigh = neigh_create(&nd_tbl, &msg->target, dev); 1082 new_state = NUD_STALE; 1083 } 1084 } 1085 1086 if (neigh && !IS_ERR(neigh)) { 1087 u8 old_flags = neigh->flags; 1088 struct net *net = dev_net(dev); 1089 1090 if (READ_ONCE(neigh->nud_state) & NUD_FAILED) 1091 goto out; 1092 1093 /* 1094 * Don't update the neighbor cache entry on a proxy NA from 1095 * ourselves because either the proxied node is off link or it 1096 * has already sent a NA to us. 1097 */ 1098 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) && 1099 READ_ONCE(net->ipv6.devconf_all->forwarding) && 1100 READ_ONCE(net->ipv6.devconf_all->proxy_ndp) && 1101 pneigh_lookup(&nd_tbl, net, &msg->target, dev)) { 1102 /* XXX: idev->cnf.proxy_ndp */ 1103 goto out; 1104 } 1105 1106 ndisc_update(dev, neigh, lladdr, 1107 new_state, 1108 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1109 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)| 1110 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1111 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0), 1112 NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts); 1113 1114 if ((old_flags & ~neigh->flags) & NTF_ROUTER) { 1115 /* 1116 * Change: router to host 1117 */ 1118 rt6_clean_tohost(dev_net(dev), saddr); 1119 } 1120 reason = SKB_CONSUMED; 1121 out: 1122 neigh_release(neigh); 1123 } 1124 return reason; 1125 } 1126 1127 static enum skb_drop_reason ndisc_recv_rs(struct sk_buff *skb) 1128 { 1129 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb); 1130 unsigned long ndoptlen = skb->len - sizeof(*rs_msg); 1131 struct neighbour *neigh; 1132 struct inet6_dev *idev; 1133 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 1134 struct ndisc_options ndopts; 1135 u8 *lladdr = NULL; 1136 SKB_DR(reason); 1137 1138 if (skb->len < sizeof(*rs_msg)) 1139 return SKB_DROP_REASON_PKT_TOO_SMALL; 1140 1141 idev = __in6_dev_get(skb->dev); 1142 if (!idev) { 1143 net_err_ratelimited("RS: can't find in6 device\n"); 1144 return reason; 1145 } 1146 1147 /* Don't accept RS if we're not in router mode */ 1148 if (!READ_ONCE(idev->cnf.forwarding)) 1149 goto out; 1150 1151 /* 1152 * Don't update NCE if src = ::; 1153 * this implies that the source node has no ip address assigned yet. 1154 */ 1155 if (ipv6_addr_any(saddr)) 1156 goto out; 1157 1158 /* Parse ND options */ 1159 if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) 1160 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1161 1162 if (ndopts.nd_opts_src_lladdr) { 1163 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1164 skb->dev); 1165 if (!lladdr) 1166 goto out; 1167 } 1168 1169 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1); 1170 if (neigh) { 1171 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE, 1172 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1173 NEIGH_UPDATE_F_OVERRIDE| 1174 NEIGH_UPDATE_F_OVERRIDE_ISROUTER, 1175 NDISC_ROUTER_SOLICITATION, &ndopts); 1176 neigh_release(neigh); 1177 reason = SKB_CONSUMED; 1178 } 1179 out: 1180 return reason; 1181 } 1182 1183 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt) 1184 { 1185 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra); 1186 struct sk_buff *skb; 1187 struct nlmsghdr *nlh; 1188 struct nduseroptmsg *ndmsg; 1189 struct net *net = dev_net(ra->dev); 1190 int err; 1191 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg) 1192 + (opt->nd_opt_len << 3)); 1193 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr)); 1194 1195 skb = nlmsg_new(msg_size, GFP_ATOMIC); 1196 if (!skb) { 1197 err = -ENOBUFS; 1198 goto errout; 1199 } 1200 1201 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0); 1202 if (!nlh) { 1203 goto nla_put_failure; 1204 } 1205 1206 ndmsg = nlmsg_data(nlh); 1207 ndmsg->nduseropt_family = AF_INET6; 1208 ndmsg->nduseropt_ifindex = ra->dev->ifindex; 1209 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type; 1210 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code; 1211 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3; 1212 1213 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3); 1214 1215 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr)) 1216 goto nla_put_failure; 1217 nlmsg_end(skb, nlh); 1218 1219 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC); 1220 return; 1221 1222 nla_put_failure: 1223 nlmsg_free(skb); 1224 err = -EMSGSIZE; 1225 errout: 1226 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err); 1227 } 1228 1229 static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb) 1230 { 1231 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb); 1232 bool send_ifinfo_notify = false; 1233 struct neighbour *neigh = NULL; 1234 struct ndisc_options ndopts; 1235 struct fib6_info *rt = NULL; 1236 struct inet6_dev *in6_dev; 1237 struct fib6_table *table; 1238 u32 defrtr_usr_metric; 1239 unsigned int pref = 0; 1240 __u32 old_if_flags; 1241 struct net *net; 1242 SKB_DR(reason); 1243 int lifetime; 1244 int optlen; 1245 1246 __u8 *opt = (__u8 *)(ra_msg + 1); 1247 1248 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) - 1249 sizeof(struct ra_msg); 1250 1251 net_dbg_ratelimited("RA: %s, dev: %s\n", __func__, skb->dev->name); 1252 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1253 net_dbg_ratelimited("RA: source address is not link-local\n"); 1254 return reason; 1255 } 1256 if (optlen < 0) 1257 return SKB_DROP_REASON_PKT_TOO_SMALL; 1258 1259 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1260 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) { 1261 net_dbg_ratelimited("RA: from host or unauthorized router\n"); 1262 return reason; 1263 } 1264 #endif 1265 1266 in6_dev = __in6_dev_get(skb->dev); 1267 if (!in6_dev) { 1268 net_err_ratelimited("RA: can't find inet6 device for %s\n", skb->dev->name); 1269 return reason; 1270 } 1271 1272 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) 1273 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1274 1275 if (!ipv6_accept_ra(in6_dev)) { 1276 net_dbg_ratelimited("RA: %s, did not accept ra for dev: %s\n", __func__, 1277 skb->dev->name); 1278 goto skip_linkparms; 1279 } 1280 1281 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1282 /* skip link-specific parameters from interior routers */ 1283 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1284 net_dbg_ratelimited("RA: %s, nodetype is NODEFAULT, dev: %s\n", __func__, 1285 skb->dev->name); 1286 goto skip_linkparms; 1287 } 1288 #endif 1289 1290 if (in6_dev->if_flags & IF_RS_SENT) { 1291 /* 1292 * flag that an RA was received after an RS was sent 1293 * out on this interface. 1294 */ 1295 in6_dev->if_flags |= IF_RA_RCVD; 1296 } 1297 1298 /* 1299 * Remember the managed/otherconf flags from most recently 1300 * received RA message (RFC 2462) -- yoshfuji 1301 */ 1302 old_if_flags = in6_dev->if_flags; 1303 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED | 1304 IF_RA_OTHERCONF)) | 1305 (ra_msg->icmph.icmp6_addrconf_managed ? 1306 IF_RA_MANAGED : 0) | 1307 (ra_msg->icmph.icmp6_addrconf_other ? 1308 IF_RA_OTHERCONF : 0); 1309 1310 if (old_if_flags != in6_dev->if_flags) 1311 send_ifinfo_notify = true; 1312 1313 if (!READ_ONCE(in6_dev->cnf.accept_ra_defrtr)) { 1314 net_dbg_ratelimited("RA: %s, defrtr is false for dev: %s\n", __func__, 1315 skb->dev->name); 1316 goto skip_defrtr; 1317 } 1318 1319 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); 1320 if (lifetime != 0 && 1321 lifetime < READ_ONCE(in6_dev->cnf.accept_ra_min_lft)) { 1322 net_dbg_ratelimited("RA: router lifetime (%ds) is too short: %s\n", lifetime, 1323 skb->dev->name); 1324 goto skip_defrtr; 1325 } 1326 1327 /* Do not accept RA with source-addr found on local machine unless 1328 * accept_ra_from_local is set to true. 1329 */ 1330 net = dev_net(in6_dev->dev); 1331 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) && 1332 ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) { 1333 net_dbg_ratelimited("RA from local address detected on dev: %s: default router ignored\n", 1334 skb->dev->name); 1335 goto skip_defrtr; 1336 } 1337 1338 #ifdef CONFIG_IPV6_ROUTER_PREF 1339 pref = ra_msg->icmph.icmp6_router_pref; 1340 /* 10b is handled as if it were 00b (medium) */ 1341 if (pref == ICMPV6_ROUTER_PREF_INVALID || 1342 !READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref)) 1343 pref = ICMPV6_ROUTER_PREF_MEDIUM; 1344 #endif 1345 /* routes added from RAs do not use nexthop objects */ 1346 rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev); 1347 if (rt) { 1348 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6, 1349 rt->fib6_nh->fib_nh_dev, NULL, 1350 &ipv6_hdr(skb)->saddr); 1351 if (!neigh) { 1352 net_err_ratelimited("RA: %s got default router without neighbour\n", 1353 __func__); 1354 fib6_info_release(rt); 1355 return reason; 1356 } 1357 } 1358 /* Set default route metric as specified by user */ 1359 defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric; 1360 /* delete the route if lifetime is 0 or if metric needs change */ 1361 if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) { 1362 ip6_del_rt(net, rt, false); 1363 rt = NULL; 1364 } 1365 1366 net_dbg_ratelimited("RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n", rt, lifetime, 1367 defrtr_usr_metric, skb->dev->name); 1368 if (!rt && lifetime) { 1369 net_dbg_ratelimited("RA: adding default router\n"); 1370 1371 if (neigh) 1372 neigh_release(neigh); 1373 1374 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr, 1375 skb->dev, pref, defrtr_usr_metric, 1376 lifetime); 1377 if (!rt) { 1378 net_err_ratelimited("RA: %s failed to add default route\n", __func__); 1379 return reason; 1380 } 1381 1382 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6, 1383 rt->fib6_nh->fib_nh_dev, NULL, 1384 &ipv6_hdr(skb)->saddr); 1385 if (!neigh) { 1386 net_err_ratelimited("RA: %s got default router without neighbour\n", 1387 __func__); 1388 fib6_info_release(rt); 1389 return reason; 1390 } 1391 neigh->flags |= NTF_ROUTER; 1392 } else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) { 1393 struct nl_info nlinfo = { 1394 .nl_net = net, 1395 }; 1396 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 1397 inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_REPLACE); 1398 } 1399 1400 if (rt) { 1401 table = rt->fib6_table; 1402 spin_lock_bh(&table->tb6_lock); 1403 1404 fib6_set_expires(rt, jiffies + (HZ * lifetime)); 1405 fib6_add_gc_list(rt); 1406 1407 spin_unlock_bh(&table->tb6_lock); 1408 } 1409 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) < 256 && 1410 ra_msg->icmph.icmp6_hop_limit) { 1411 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) <= 1412 ra_msg->icmph.icmp6_hop_limit) { 1413 WRITE_ONCE(in6_dev->cnf.hop_limit, 1414 ra_msg->icmph.icmp6_hop_limit); 1415 fib6_metric_set(rt, RTAX_HOPLIMIT, 1416 ra_msg->icmph.icmp6_hop_limit); 1417 } else { 1418 net_dbg_ratelimited("RA: Got route advertisement with lower hop_limit than minimum\n"); 1419 } 1420 } 1421 1422 skip_defrtr: 1423 1424 /* 1425 * Update Reachable Time and Retrans Timer 1426 */ 1427 1428 if (in6_dev->nd_parms) { 1429 unsigned long rtime = ntohl(ra_msg->retrans_timer); 1430 1431 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) { 1432 rtime = (rtime*HZ)/1000; 1433 if (rtime < HZ/100) 1434 rtime = HZ/100; 1435 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime); 1436 in6_dev->tstamp = jiffies; 1437 send_ifinfo_notify = true; 1438 } 1439 1440 rtime = ntohl(ra_msg->reachable_time); 1441 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) { 1442 rtime = (rtime*HZ)/1000; 1443 1444 if (rtime < HZ/10) 1445 rtime = HZ/10; 1446 1447 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) { 1448 NEIGH_VAR_SET(in6_dev->nd_parms, 1449 BASE_REACHABLE_TIME, rtime); 1450 NEIGH_VAR_SET(in6_dev->nd_parms, 1451 GC_STALETIME, 3 * rtime); 1452 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime); 1453 in6_dev->tstamp = jiffies; 1454 send_ifinfo_notify = true; 1455 } 1456 } 1457 } 1458 1459 skip_linkparms: 1460 1461 /* 1462 * Process options. 1463 */ 1464 1465 if (!neigh) 1466 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr, 1467 skb->dev, 1); 1468 if (neigh) { 1469 u8 *lladdr = NULL; 1470 if (ndopts.nd_opts_src_lladdr) { 1471 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1472 skb->dev); 1473 if (!lladdr) { 1474 net_dbg_ratelimited("RA: invalid link-layer address length\n"); 1475 goto out; 1476 } 1477 } 1478 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE, 1479 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1480 NEIGH_UPDATE_F_OVERRIDE| 1481 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1482 NEIGH_UPDATE_F_ISROUTER, 1483 NDISC_ROUTER_ADVERTISEMENT, &ndopts); 1484 reason = SKB_CONSUMED; 1485 } 1486 1487 if (!ipv6_accept_ra(in6_dev)) { 1488 net_dbg_ratelimited("RA: %s, accept_ra is false for dev: %s\n", __func__, 1489 skb->dev->name); 1490 goto out; 1491 } 1492 1493 #ifdef CONFIG_IPV6_ROUTE_INFO 1494 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) && 1495 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, 1496 in6_dev->dev, 0)) { 1497 net_dbg_ratelimited("RA from local address detected on dev: %s: router info ignored.\n", 1498 skb->dev->name); 1499 goto skip_routeinfo; 1500 } 1501 1502 if (READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref) && ndopts.nd_opts_ri) { 1503 struct nd_opt_hdr *p; 1504 for (p = ndopts.nd_opts_ri; 1505 p; 1506 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) { 1507 struct route_info *ri = (struct route_info *)p; 1508 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1509 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT && 1510 ri->prefix_len == 0) 1511 continue; 1512 #endif 1513 if (ri->prefix_len == 0 && 1514 !READ_ONCE(in6_dev->cnf.accept_ra_defrtr)) 1515 continue; 1516 if (ri->lifetime != 0 && 1517 ntohl(ri->lifetime) < READ_ONCE(in6_dev->cnf.accept_ra_min_lft)) 1518 continue; 1519 if (ri->prefix_len < READ_ONCE(in6_dev->cnf.accept_ra_rt_info_min_plen)) 1520 continue; 1521 if (ri->prefix_len > READ_ONCE(in6_dev->cnf.accept_ra_rt_info_max_plen)) 1522 continue; 1523 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3, 1524 &ipv6_hdr(skb)->saddr); 1525 } 1526 } 1527 1528 skip_routeinfo: 1529 #endif 1530 1531 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1532 /* skip link-specific ndopts from interior routers */ 1533 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1534 net_dbg_ratelimited("RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n", 1535 __func__, skb->dev->name); 1536 goto out; 1537 } 1538 #endif 1539 1540 if (READ_ONCE(in6_dev->cnf.accept_ra_pinfo) && ndopts.nd_opts_pi) { 1541 struct nd_opt_hdr *p; 1542 for (p = ndopts.nd_opts_pi; 1543 p; 1544 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) { 1545 addrconf_prefix_rcv(skb->dev, (u8 *)p, 1546 (p->nd_opt_len) << 3, 1547 ndopts.nd_opts_src_lladdr != NULL); 1548 } 1549 } 1550 1551 if (ndopts.nd_opts_mtu && READ_ONCE(in6_dev->cnf.accept_ra_mtu)) { 1552 __be32 n; 1553 u32 mtu; 1554 1555 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); 1556 mtu = ntohl(n); 1557 1558 if (in6_dev->ra_mtu != mtu) { 1559 in6_dev->ra_mtu = mtu; 1560 send_ifinfo_notify = true; 1561 } 1562 1563 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { 1564 net_dbg_ratelimited("RA: invalid mtu: %d\n", mtu); 1565 } else if (READ_ONCE(in6_dev->cnf.mtu6) != mtu) { 1566 WRITE_ONCE(in6_dev->cnf.mtu6, mtu); 1567 fib6_metric_set(rt, RTAX_MTU, mtu); 1568 rt6_mtu_change(skb->dev, mtu); 1569 } 1570 } 1571 1572 if (ndopts.nd_useropts) { 1573 struct nd_opt_hdr *p; 1574 for (p = ndopts.nd_useropts; 1575 p; 1576 p = ndisc_next_useropt(skb->dev, p, 1577 ndopts.nd_useropts_end)) { 1578 ndisc_ra_useropt(skb, p); 1579 } 1580 } 1581 1582 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { 1583 net_dbg_ratelimited("RA: invalid RA options\n"); 1584 } 1585 out: 1586 /* Send a notify if RA changed managed/otherconf flags or 1587 * timer settings or ra_mtu value 1588 */ 1589 if (send_ifinfo_notify) 1590 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1591 1592 fib6_info_release(rt); 1593 if (neigh) 1594 neigh_release(neigh); 1595 return reason; 1596 } 1597 1598 static enum skb_drop_reason ndisc_redirect_rcv(struct sk_buff *skb) 1599 { 1600 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb); 1601 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 1602 offsetof(struct rd_msg, opt)); 1603 struct ndisc_options ndopts; 1604 SKB_DR(reason); 1605 u8 *hdr; 1606 1607 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1608 switch (skb->ndisc_nodetype) { 1609 case NDISC_NODETYPE_HOST: 1610 case NDISC_NODETYPE_NODEFAULT: 1611 net_dbg_ratelimited("Redirect: from host or unauthorized router\n"); 1612 return reason; 1613 } 1614 #endif 1615 1616 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1617 net_dbg_ratelimited("Redirect: source address is not link-local\n"); 1618 return reason; 1619 } 1620 1621 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts)) 1622 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1623 1624 if (!ndopts.nd_opts_rh) { 1625 ip6_redirect_no_header(skb, dev_net(skb->dev), 1626 skb->dev->ifindex); 1627 return reason; 1628 } 1629 1630 hdr = (u8 *)ndopts.nd_opts_rh; 1631 hdr += 8; 1632 if (!pskb_pull(skb, hdr - skb_transport_header(skb))) 1633 return SKB_DROP_REASON_PKT_TOO_SMALL; 1634 1635 return icmpv6_notify(skb, NDISC_REDIRECT, 0, 0); 1636 } 1637 1638 static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb, 1639 struct sk_buff *orig_skb, 1640 int rd_len) 1641 { 1642 u8 *opt = skb_put(skb, rd_len); 1643 1644 memset(opt, 0, 8); 1645 *(opt++) = ND_OPT_REDIRECT_HDR; 1646 *(opt++) = (rd_len >> 3); 1647 opt += 6; 1648 1649 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt, 1650 rd_len - 8); 1651 } 1652 1653 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target) 1654 { 1655 struct net_device *dev = skb->dev; 1656 struct net *net = dev_net_rcu(dev); 1657 struct sock *sk = net->ipv6.ndisc_sk; 1658 int optlen = 0; 1659 struct inet_peer *peer; 1660 struct sk_buff *buff; 1661 struct rd_msg *msg; 1662 struct in6_addr saddr_buf; 1663 struct rt6_info *rt; 1664 struct dst_entry *dst; 1665 struct flowi6 fl6; 1666 int rd_len; 1667 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL, 1668 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL; 1669 bool ret; 1670 1671 if (netif_is_l3_master(dev)) { 1672 dev = dev_get_by_index_rcu(net, IPCB(skb)->iif); 1673 if (!dev) 1674 return; 1675 } 1676 1677 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) { 1678 net_dbg_ratelimited("Redirect: no link-local address on %s\n", dev->name); 1679 return; 1680 } 1681 1682 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) && 1683 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1684 net_dbg_ratelimited("Redirect: target address is not link-local unicast\n"); 1685 return; 1686 } 1687 1688 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT, 1689 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex); 1690 1691 dst = ip6_route_output(net, NULL, &fl6); 1692 if (dst->error) { 1693 dst_release(dst); 1694 return; 1695 } 1696 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); 1697 if (IS_ERR(dst)) 1698 return; 1699 1700 rt = dst_rt6_info(dst); 1701 1702 if (rt->rt6i_flags & RTF_GATEWAY) { 1703 net_dbg_ratelimited("Redirect: destination is not a neighbour\n"); 1704 goto release; 1705 } 1706 1707 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr); 1708 ret = inet_peer_xrlim_allow(peer, 1*HZ); 1709 1710 if (!ret) 1711 goto release; 1712 1713 if (dev->addr_len) { 1714 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target); 1715 if (!neigh) { 1716 net_dbg_ratelimited("Redirect: no neigh for target address\n"); 1717 goto release; 1718 } 1719 1720 read_lock_bh(&neigh->lock); 1721 if (neigh->nud_state & NUD_VALID) { 1722 memcpy(ha_buf, neigh->ha, dev->addr_len); 1723 read_unlock_bh(&neigh->lock); 1724 ha = ha_buf; 1725 optlen += ndisc_redirect_opt_addr_space(dev, neigh, 1726 ops_data_buf, 1727 &ops_data); 1728 } else 1729 read_unlock_bh(&neigh->lock); 1730 1731 neigh_release(neigh); 1732 } 1733 1734 rd_len = min_t(unsigned int, 1735 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen, 1736 skb->len + 8); 1737 rd_len &= ~0x7; 1738 optlen += rd_len; 1739 1740 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 1741 if (!buff) 1742 goto release; 1743 1744 msg = skb_put(buff, sizeof(*msg)); 1745 *msg = (struct rd_msg) { 1746 .icmph = { 1747 .icmp6_type = NDISC_REDIRECT, 1748 }, 1749 .target = *target, 1750 .dest = ipv6_hdr(skb)->daddr, 1751 }; 1752 1753 /* 1754 * include target_address option 1755 */ 1756 1757 if (ha) 1758 ndisc_fill_redirect_addr_option(buff, ha, ops_data); 1759 1760 /* 1761 * build redirect option and copy skb over to the new packet. 1762 */ 1763 1764 if (rd_len) 1765 ndisc_fill_redirect_hdr_option(buff, skb, rd_len); 1766 1767 skb_dst_set(buff, dst); 1768 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf); 1769 return; 1770 1771 release: 1772 dst_release(dst); 1773 } 1774 1775 static void pndisc_redo(struct sk_buff *skb) 1776 { 1777 enum skb_drop_reason reason = ndisc_recv_ns(skb); 1778 1779 kfree_skb_reason(skb, reason); 1780 } 1781 1782 static int ndisc_is_multicast(const void *pkey) 1783 { 1784 return ipv6_addr_is_multicast((struct in6_addr *)pkey); 1785 } 1786 1787 static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb) 1788 { 1789 struct inet6_dev *idev = __in6_dev_get(skb->dev); 1790 1791 if (!idev) 1792 return true; 1793 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED && 1794 READ_ONCE(idev->cnf.suppress_frag_ndisc)) { 1795 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n"); 1796 return true; 1797 } 1798 return false; 1799 } 1800 1801 enum skb_drop_reason ndisc_rcv(struct sk_buff *skb) 1802 { 1803 struct nd_msg *msg; 1804 SKB_DR(reason); 1805 1806 if (ndisc_suppress_frag_ndisc(skb)) 1807 return SKB_DROP_REASON_IPV6_NDISC_FRAG; 1808 1809 if (skb_linearize(skb)) 1810 return SKB_DROP_REASON_NOMEM; 1811 1812 msg = (struct nd_msg *)skb_transport_header(skb); 1813 1814 __skb_push(skb, skb->data - skb_transport_header(skb)); 1815 1816 if (ipv6_hdr(skb)->hop_limit != 255) { 1817 net_dbg_ratelimited("NDISC: invalid hop-limit: %d\n", ipv6_hdr(skb)->hop_limit); 1818 return SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT; 1819 } 1820 1821 if (msg->icmph.icmp6_code != 0) { 1822 net_dbg_ratelimited("NDISC: invalid ICMPv6 code: %d\n", msg->icmph.icmp6_code); 1823 return SKB_DROP_REASON_IPV6_NDISC_BAD_CODE; 1824 } 1825 1826 switch (msg->icmph.icmp6_type) { 1827 case NDISC_NEIGHBOUR_SOLICITATION: 1828 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 1829 reason = ndisc_recv_ns(skb); 1830 break; 1831 1832 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1833 reason = ndisc_recv_na(skb); 1834 break; 1835 1836 case NDISC_ROUTER_SOLICITATION: 1837 reason = ndisc_recv_rs(skb); 1838 break; 1839 1840 case NDISC_ROUTER_ADVERTISEMENT: 1841 reason = ndisc_router_discovery(skb); 1842 break; 1843 1844 case NDISC_REDIRECT: 1845 reason = ndisc_redirect_rcv(skb); 1846 break; 1847 } 1848 1849 return reason; 1850 } 1851 1852 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1853 { 1854 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1855 struct netdev_notifier_change_info *change_info; 1856 struct net *net = dev_net(dev); 1857 struct inet6_dev *idev; 1858 bool evict_nocarrier; 1859 1860 switch (event) { 1861 case NETDEV_CHANGEADDR: 1862 neigh_changeaddr(&nd_tbl, dev); 1863 fib6_run_gc(0, net, false); 1864 fallthrough; 1865 case NETDEV_UP: 1866 idev = in6_dev_get(dev); 1867 if (!idev) 1868 break; 1869 if (READ_ONCE(idev->cnf.ndisc_notify) || 1870 READ_ONCE(net->ipv6.devconf_all->ndisc_notify)) 1871 ndisc_send_unsol_na(dev); 1872 in6_dev_put(idev); 1873 break; 1874 case NETDEV_CHANGE: 1875 idev = in6_dev_get(dev); 1876 if (!idev) 1877 evict_nocarrier = true; 1878 else { 1879 evict_nocarrier = READ_ONCE(idev->cnf.ndisc_evict_nocarrier) && 1880 READ_ONCE(net->ipv6.devconf_all->ndisc_evict_nocarrier); 1881 in6_dev_put(idev); 1882 } 1883 1884 change_info = ptr; 1885 if (change_info->flags_changed & IFF_NOARP) 1886 neigh_changeaddr(&nd_tbl, dev); 1887 if (evict_nocarrier && !netif_carrier_ok(dev)) 1888 neigh_carrier_down(&nd_tbl, dev); 1889 break; 1890 case NETDEV_DOWN: 1891 neigh_ifdown(&nd_tbl, dev); 1892 fib6_run_gc(0, net, false); 1893 break; 1894 case NETDEV_NOTIFY_PEERS: 1895 ndisc_send_unsol_na(dev); 1896 break; 1897 default: 1898 break; 1899 } 1900 1901 return NOTIFY_DONE; 1902 } 1903 1904 static struct notifier_block ndisc_netdev_notifier = { 1905 .notifier_call = ndisc_netdev_event, 1906 .priority = ADDRCONF_NOTIFY_PRIORITY - 5, 1907 }; 1908 1909 #ifdef CONFIG_SYSCTL 1910 static void ndisc_warn_deprecated_sysctl(const struct ctl_table *ctl, 1911 const char *func, const char *dev_name) 1912 { 1913 static char warncomm[TASK_COMM_LEN]; 1914 static int warned; 1915 if (strcmp(warncomm, current->comm) && warned < 5) { 1916 strscpy(warncomm, current->comm); 1917 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n", 1918 warncomm, func, 1919 dev_name, ctl->procname, 1920 dev_name, ctl->procname); 1921 warned++; 1922 } 1923 } 1924 1925 int ndisc_ifinfo_sysctl_change(const struct ctl_table *ctl, int write, void *buffer, 1926 size_t *lenp, loff_t *ppos) 1927 { 1928 struct net_device *dev = ctl->extra1; 1929 struct inet6_dev *idev; 1930 int ret; 1931 1932 if ((strcmp(ctl->procname, "retrans_time") == 0) || 1933 (strcmp(ctl->procname, "base_reachable_time") == 0)) 1934 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default"); 1935 1936 if (strcmp(ctl->procname, "retrans_time") == 0) 1937 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos); 1938 1939 else if (strcmp(ctl->procname, "base_reachable_time") == 0) 1940 ret = neigh_proc_dointvec_jiffies(ctl, write, 1941 buffer, lenp, ppos); 1942 1943 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) || 1944 (strcmp(ctl->procname, "base_reachable_time_ms") == 0)) 1945 ret = neigh_proc_dointvec_ms_jiffies(ctl, write, 1946 buffer, lenp, ppos); 1947 else 1948 ret = -1; 1949 1950 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) { 1951 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)) 1952 idev->nd_parms->reachable_time = 1953 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)); 1954 WRITE_ONCE(idev->tstamp, jiffies); 1955 inet6_ifinfo_notify(RTM_NEWLINK, idev); 1956 in6_dev_put(idev); 1957 } 1958 return ret; 1959 } 1960 1961 1962 #endif 1963 1964 static int __net_init ndisc_net_init(struct net *net) 1965 { 1966 struct ipv6_pinfo *np; 1967 struct sock *sk; 1968 int err; 1969 1970 err = inet_ctl_sock_create(&sk, PF_INET6, 1971 SOCK_RAW, IPPROTO_ICMPV6, net); 1972 if (err < 0) { 1973 net_err_ratelimited("NDISC: Failed to initialize the control socket (err %d)\n", 1974 err); 1975 return err; 1976 } 1977 1978 net->ipv6.ndisc_sk = sk; 1979 1980 np = inet6_sk(sk); 1981 np->hop_limit = 255; 1982 /* Do not loopback ndisc messages */ 1983 inet6_clear_bit(MC6_LOOP, sk); 1984 1985 return 0; 1986 } 1987 1988 static void __net_exit ndisc_net_exit(struct net *net) 1989 { 1990 inet_ctl_sock_destroy(net->ipv6.ndisc_sk); 1991 } 1992 1993 static struct pernet_operations ndisc_net_ops = { 1994 .init = ndisc_net_init, 1995 .exit = ndisc_net_exit, 1996 }; 1997 1998 int __init ndisc_init(void) 1999 { 2000 int err; 2001 2002 err = register_pernet_subsys(&ndisc_net_ops); 2003 if (err) 2004 return err; 2005 /* 2006 * Initialize the neighbour table 2007 */ 2008 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl); 2009 2010 #ifdef CONFIG_SYSCTL 2011 err = neigh_sysctl_register(NULL, &nd_tbl.parms, 2012 ndisc_ifinfo_sysctl_change); 2013 if (err) 2014 goto out_unregister_pernet; 2015 out: 2016 #endif 2017 return err; 2018 2019 #ifdef CONFIG_SYSCTL 2020 out_unregister_pernet: 2021 unregister_pernet_subsys(&ndisc_net_ops); 2022 goto out; 2023 #endif 2024 } 2025 2026 int __init ndisc_late_init(void) 2027 { 2028 return register_netdevice_notifier(&ndisc_netdev_notifier); 2029 } 2030 2031 void ndisc_late_cleanup(void) 2032 { 2033 unregister_netdevice_notifier(&ndisc_netdev_notifier); 2034 } 2035 2036 void ndisc_cleanup(void) 2037 { 2038 #ifdef CONFIG_SYSCTL 2039 neigh_sysctl_unregister(&nd_tbl.parms); 2040 #endif 2041 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl); 2042 unregister_pernet_subsys(&ndisc_net_ops); 2043 } 2044