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_DEFAULT, 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_rcu(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 EXPORT_SYMBOL_GPL(ndisc_send_na); 580 581 static void ndisc_send_unsol_na(struct net_device *dev) 582 { 583 struct inet6_dev *idev; 584 struct inet6_ifaddr *ifa; 585 586 idev = in6_dev_get(dev); 587 if (!idev) 588 return; 589 590 read_lock_bh(&idev->lock); 591 list_for_each_entry(ifa, &idev->addr_list, if_list) { 592 /* skip tentative addresses until dad completes */ 593 if (ifa->flags & IFA_F_TENTATIVE && 594 !(ifa->flags & IFA_F_OPTIMISTIC)) 595 continue; 596 597 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr, 598 /*router=*/ !!idev->cnf.forwarding, 599 /*solicited=*/ false, /*override=*/ true, 600 /*inc_opt=*/ true); 601 } 602 read_unlock_bh(&idev->lock); 603 604 in6_dev_put(idev); 605 } 606 607 struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit, 608 const struct in6_addr *saddr, u64 nonce) 609 { 610 int inc_opt = dev->addr_len; 611 struct sk_buff *skb; 612 struct nd_msg *msg; 613 int optlen = 0; 614 615 if (!saddr) 616 return NULL; 617 618 if (ipv6_addr_any(saddr)) 619 inc_opt = false; 620 if (inc_opt) 621 optlen += ndisc_opt_addr_space(dev, 622 NDISC_NEIGHBOUR_SOLICITATION); 623 if (nonce != 0) 624 optlen += 8; 625 626 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 627 if (!skb) 628 return NULL; 629 630 msg = skb_put(skb, sizeof(*msg)); 631 *msg = (struct nd_msg) { 632 .icmph = { 633 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION, 634 }, 635 .target = *solicit, 636 }; 637 638 if (inc_opt) 639 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR, 640 dev->dev_addr, 641 NDISC_NEIGHBOUR_SOLICITATION); 642 if (nonce != 0) { 643 u8 *opt = skb_put(skb, 8); 644 645 opt[0] = ND_OPT_NONCE; 646 opt[1] = 8 >> 3; 647 memcpy(opt + 2, &nonce, 6); 648 } 649 650 return skb; 651 } 652 EXPORT_SYMBOL(ndisc_ns_create); 653 654 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit, 655 const struct in6_addr *daddr, const struct in6_addr *saddr, 656 u64 nonce) 657 { 658 struct in6_addr addr_buf; 659 struct sk_buff *skb; 660 661 if (!saddr) { 662 if (ipv6_get_lladdr(dev, &addr_buf, 663 (IFA_F_TENTATIVE | IFA_F_OPTIMISTIC))) 664 return; 665 saddr = &addr_buf; 666 } 667 668 skb = ndisc_ns_create(dev, solicit, saddr, nonce); 669 670 if (skb) 671 ndisc_send_skb(skb, daddr, saddr); 672 } 673 674 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr, 675 const struct in6_addr *daddr) 676 { 677 struct sk_buff *skb; 678 struct rs_msg *msg; 679 int send_sllao = dev->addr_len; 680 int optlen = 0; 681 682 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 683 /* 684 * According to section 2.2 of RFC 4429, we must not 685 * send router solicitations with a sllao from 686 * optimistic addresses, but we may send the solicitation 687 * if we don't include the sllao. So here we check 688 * if our address is optimistic, and if so, we 689 * suppress the inclusion of the sllao. 690 */ 691 if (send_sllao) { 692 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr, 693 dev, 1); 694 if (ifp) { 695 if (ifp->flags & IFA_F_OPTIMISTIC) { 696 send_sllao = 0; 697 } 698 in6_ifa_put(ifp); 699 } else { 700 send_sllao = 0; 701 } 702 } 703 #endif 704 if (send_sllao) 705 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION); 706 707 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 708 if (!skb) 709 return; 710 711 msg = skb_put(skb, sizeof(*msg)); 712 *msg = (struct rs_msg) { 713 .icmph = { 714 .icmp6_type = NDISC_ROUTER_SOLICITATION, 715 }, 716 }; 717 718 if (send_sllao) 719 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR, 720 dev->dev_addr, 721 NDISC_ROUTER_SOLICITATION); 722 723 ndisc_send_skb(skb, daddr, saddr); 724 } 725 726 727 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb) 728 { 729 /* 730 * "The sender MUST return an ICMP 731 * destination unreachable" 732 */ 733 dst_link_failure(skb); 734 kfree_skb(skb); 735 } 736 737 /* Called with locked neigh: either read or both */ 738 739 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb) 740 { 741 struct in6_addr *saddr = NULL; 742 struct in6_addr mcaddr; 743 struct net_device *dev = neigh->dev; 744 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key; 745 int probes = atomic_read(&neigh->probes); 746 747 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr, 748 dev, false, 1, 749 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) 750 saddr = &ipv6_hdr(skb)->saddr; 751 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES); 752 if (probes < 0) { 753 if (!(READ_ONCE(neigh->nud_state) & NUD_VALID)) { 754 net_dbg_ratelimited("%s: trying to ucast probe in NUD_INVALID: %pI6\n", 755 __func__, target); 756 } 757 ndisc_send_ns(dev, target, target, saddr, 0); 758 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) { 759 neigh_app_ns(neigh); 760 } else { 761 addrconf_addr_solict_mult(target, &mcaddr); 762 ndisc_send_ns(dev, target, &mcaddr, saddr, 0); 763 } 764 } 765 766 static int pndisc_is_router(const void *pkey, 767 struct net_device *dev) 768 { 769 struct pneigh_entry *n; 770 int ret = -1; 771 772 n = pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev); 773 if (n) 774 ret = !!(READ_ONCE(n->flags) & NTF_ROUTER); 775 776 return ret; 777 } 778 779 void ndisc_update(const struct net_device *dev, struct neighbour *neigh, 780 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type, 781 struct ndisc_options *ndopts) 782 { 783 neigh_update(neigh, lladdr, new, flags, 0); 784 /* report ndisc ops about neighbour update */ 785 ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts); 786 } 787 788 static enum skb_drop_reason ndisc_recv_ns(struct sk_buff *skb) 789 { 790 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 791 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 792 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 793 u8 *lladdr = NULL; 794 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 795 offsetof(struct nd_msg, opt)); 796 struct ndisc_options ndopts; 797 struct net_device *dev = skb->dev; 798 struct inet6_ifaddr *ifp; 799 struct inet6_dev *idev = NULL; 800 struct neighbour *neigh; 801 int dad = ipv6_addr_any(saddr); 802 int is_router = -1; 803 SKB_DR(reason); 804 u64 nonce = 0; 805 bool inc; 806 807 if (skb->len < sizeof(struct nd_msg)) 808 return SKB_DROP_REASON_PKT_TOO_SMALL; 809 810 if (ipv6_addr_is_multicast(&msg->target)) { 811 net_dbg_ratelimited("NS: multicast target address\n"); 812 return reason; 813 } 814 815 /* 816 * RFC2461 7.1.1: 817 * DAD has to be destined for solicited node multicast address. 818 */ 819 if (dad && !ipv6_addr_is_solict_mult(daddr)) { 820 net_dbg_ratelimited("NS: bad DAD packet (wrong destination)\n"); 821 return reason; 822 } 823 824 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) 825 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 826 827 if (ndopts.nd_opts_src_lladdr) { 828 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev); 829 if (!lladdr) { 830 net_dbg_ratelimited("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 net_dbg_ratelimited("NS: bad DAD packet (link-layer address option)\n"); 841 return reason; 842 } 843 } 844 if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1) 845 memcpy(&nonce, (u8 *)(ndopts.nd_opts_nonce + 1), 6); 846 847 inc = ipv6_addr_is_multicast(daddr); 848 849 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); 850 if (ifp) { 851 have_ifp: 852 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) { 853 if (dad) { 854 if (nonce != 0 && ifp->dad_nonce == nonce) { 855 u8 *np = (u8 *)&nonce; 856 /* Matching nonce if looped back */ 857 net_dbg_ratelimited("%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n", 858 ifp->idev->dev->name, &ifp->addr, np); 859 goto out; 860 } 861 /* 862 * We are colliding with another node 863 * who is doing DAD 864 * so fail our DAD process 865 */ 866 addrconf_dad_failure(skb, ifp); 867 return reason; 868 } else { 869 /* 870 * This is not a dad solicitation. 871 * If we are an optimistic node, 872 * we should respond. 873 * Otherwise, we should ignore it. 874 */ 875 if (!(ifp->flags & IFA_F_OPTIMISTIC)) 876 goto out; 877 } 878 } 879 880 idev = ifp->idev; 881 } else { 882 struct net *net = dev_net(dev); 883 884 /* perhaps an address on the master device */ 885 if (netif_is_l3_slave(dev)) { 886 struct net_device *mdev; 887 888 mdev = netdev_master_upper_dev_get_rcu(dev); 889 if (mdev) { 890 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1); 891 if (ifp) 892 goto have_ifp; 893 } 894 } 895 896 idev = in6_dev_get(dev); 897 if (!idev) { 898 /* XXX: count this drop? */ 899 return reason; 900 } 901 902 if (ipv6_chk_acast_addr(net, dev, &msg->target) || 903 (READ_ONCE(idev->cnf.forwarding) && 904 (READ_ONCE(net->ipv6.devconf_all->proxy_ndp) || 905 READ_ONCE(idev->cnf.proxy_ndp)) && 906 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) { 907 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) && 908 skb->pkt_type != PACKET_HOST && 909 inc && 910 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) { 911 /* 912 * for anycast or proxy, 913 * sender should delay its response 914 * by a random time between 0 and 915 * MAX_ANYCAST_DELAY_TIME seconds. 916 * (RFC2461) -- yoshfuji 917 */ 918 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC); 919 if (n) 920 pneigh_enqueue(&nd_tbl, idev->nd_parms, n); 921 goto out; 922 } 923 } else { 924 SKB_DR_SET(reason, IPV6_NDISC_NS_OTHERHOST); 925 goto out; 926 } 927 } 928 929 if (is_router < 0) 930 is_router = READ_ONCE(idev->cnf.forwarding); 931 932 if (dad) { 933 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target, 934 !!is_router, false, (ifp != NULL), true); 935 goto out; 936 } 937 938 if (inc) 939 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast); 940 else 941 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast); 942 943 /* 944 * update / create cache entry 945 * for the source address 946 */ 947 neigh = __neigh_lookup(&nd_tbl, saddr, dev, 948 !inc || lladdr || !dev->addr_len); 949 if (neigh) 950 ndisc_update(dev, neigh, lladdr, NUD_STALE, 951 NEIGH_UPDATE_F_WEAK_OVERRIDE| 952 NEIGH_UPDATE_F_OVERRIDE, 953 NDISC_NEIGHBOUR_SOLICITATION, &ndopts); 954 if (neigh || !dev->header_ops) { 955 ndisc_send_na(dev, saddr, &msg->target, !!is_router, 956 true, (ifp != NULL && inc), inc); 957 if (neigh) 958 neigh_release(neigh); 959 reason = SKB_CONSUMED; 960 } 961 962 out: 963 if (ifp) 964 in6_ifa_put(ifp); 965 else 966 in6_dev_put(idev); 967 return reason; 968 } 969 970 static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr) 971 { 972 struct inet6_dev *idev = __in6_dev_get(dev); 973 974 switch (READ_ONCE(idev->cnf.accept_untracked_na)) { 975 case 0: /* Don't accept untracked na (absent in neighbor cache) */ 976 return 0; 977 case 1: /* Create new entries from na if currently untracked */ 978 return 1; 979 case 2: /* Create new entries from untracked na only if saddr is in the 980 * same subnet as an address configured on the interface that 981 * received the na 982 */ 983 return !!ipv6_chk_prefix(saddr, dev); 984 default: 985 return 0; 986 } 987 } 988 989 static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb) 990 { 991 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 992 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 993 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 994 u8 *lladdr = NULL; 995 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 996 offsetof(struct nd_msg, opt)); 997 struct ndisc_options ndopts; 998 struct net_device *dev = skb->dev; 999 struct inet6_dev *idev = __in6_dev_get(dev); 1000 struct inet6_ifaddr *ifp; 1001 struct neighbour *neigh; 1002 SKB_DR(reason); 1003 u8 new_state; 1004 1005 if (skb->len < sizeof(struct nd_msg)) 1006 return SKB_DROP_REASON_PKT_TOO_SMALL; 1007 1008 if (ipv6_addr_is_multicast(&msg->target)) { 1009 net_dbg_ratelimited("NA: target address is multicast\n"); 1010 return reason; 1011 } 1012 1013 if (ipv6_addr_is_multicast(daddr) && 1014 msg->icmph.icmp6_solicited) { 1015 net_dbg_ratelimited("NA: solicited NA is multicasted\n"); 1016 return reason; 1017 } 1018 1019 /* For some 802.11 wireless deployments (and possibly other networks), 1020 * there will be a NA proxy and unsolicitd packets are attacks 1021 * and thus should not be accepted. 1022 * drop_unsolicited_na takes precedence over accept_untracked_na 1023 */ 1024 if (!msg->icmph.icmp6_solicited && idev && 1025 READ_ONCE(idev->cnf.drop_unsolicited_na)) 1026 return reason; 1027 1028 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) 1029 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1030 1031 if (ndopts.nd_opts_tgt_lladdr) { 1032 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev); 1033 if (!lladdr) { 1034 net_dbg_ratelimited("NA: invalid link-layer address length\n"); 1035 return reason; 1036 } 1037 } 1038 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); 1039 if (ifp) { 1040 if (skb->pkt_type != PACKET_LOOPBACK 1041 && (ifp->flags & IFA_F_TENTATIVE)) { 1042 addrconf_dad_failure(skb, ifp); 1043 return reason; 1044 } 1045 /* What should we make now? The advertisement 1046 is invalid, but ndisc specs say nothing 1047 about it. It could be misconfiguration, or 1048 an smart proxy agent tries to help us :-) 1049 1050 We should not print the error if NA has been 1051 received from loopback - it is just our own 1052 unsolicited advertisement. 1053 */ 1054 if (skb->pkt_type != PACKET_LOOPBACK) 1055 net_warn_ratelimited("NA: %pM advertised our address %pI6c on %s!\n", 1056 eth_hdr(skb)->h_source, &ifp->addr, 1057 ifp->idev->dev->name); 1058 in6_ifa_put(ifp); 1059 return reason; 1060 } 1061 1062 neigh = neigh_lookup(&nd_tbl, &msg->target, dev); 1063 1064 /* RFC 9131 updates original Neighbour Discovery RFC 4861. 1065 * NAs with Target LL Address option without a corresponding 1066 * entry in the neighbour cache can now create a STALE neighbour 1067 * cache entry on routers. 1068 * 1069 * entry accept fwding solicited behaviour 1070 * ------- ------ ------ --------- ---------------------- 1071 * present X X 0 Set state to STALE 1072 * present X X 1 Set state to REACHABLE 1073 * absent 0 X X Do nothing 1074 * absent 1 0 X Do nothing 1075 * absent 1 1 X Add a new STALE entry 1076 * 1077 * Note that we don't do a (daddr == all-routers-mcast) check. 1078 */ 1079 new_state = msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE; 1080 if (!neigh && lladdr && idev && READ_ONCE(idev->cnf.forwarding)) { 1081 if (accept_untracked_na(dev, saddr)) { 1082 neigh = neigh_create(&nd_tbl, &msg->target, dev); 1083 new_state = NUD_STALE; 1084 } 1085 } 1086 1087 if (neigh && !IS_ERR(neigh)) { 1088 u8 old_flags = neigh->flags; 1089 struct net *net = dev_net(dev); 1090 1091 if (READ_ONCE(neigh->nud_state) & NUD_FAILED) 1092 goto out; 1093 1094 /* 1095 * Don't update the neighbor cache entry on a proxy NA from 1096 * ourselves because either the proxied node is off link or it 1097 * has already sent a NA to us. 1098 */ 1099 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) && 1100 READ_ONCE(net->ipv6.devconf_all->forwarding) && 1101 READ_ONCE(net->ipv6.devconf_all->proxy_ndp) && 1102 pneigh_lookup(&nd_tbl, net, &msg->target, dev)) { 1103 /* XXX: idev->cnf.proxy_ndp */ 1104 goto out; 1105 } 1106 1107 ndisc_update(dev, neigh, lladdr, 1108 new_state, 1109 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1110 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)| 1111 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1112 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0), 1113 NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts); 1114 1115 if ((old_flags & ~neigh->flags) & NTF_ROUTER) { 1116 /* 1117 * Change: router to host 1118 */ 1119 rt6_clean_tohost(dev_net(dev), saddr); 1120 } 1121 reason = SKB_CONSUMED; 1122 out: 1123 neigh_release(neigh); 1124 } 1125 return reason; 1126 } 1127 1128 static enum skb_drop_reason ndisc_recv_rs(struct sk_buff *skb) 1129 { 1130 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb); 1131 unsigned long ndoptlen = skb->len - sizeof(*rs_msg); 1132 struct neighbour *neigh; 1133 struct inet6_dev *idev; 1134 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 1135 struct ndisc_options ndopts; 1136 u8 *lladdr = NULL; 1137 SKB_DR(reason); 1138 1139 if (skb->len < sizeof(*rs_msg)) 1140 return SKB_DROP_REASON_PKT_TOO_SMALL; 1141 1142 idev = __in6_dev_get(skb->dev); 1143 if (!idev) { 1144 net_err_ratelimited("RS: can't find in6 device\n"); 1145 return reason; 1146 } 1147 1148 /* Don't accept RS if we're not in router mode */ 1149 if (!READ_ONCE(idev->cnf.forwarding)) 1150 goto out; 1151 1152 /* 1153 * Don't update NCE if src = ::; 1154 * this implies that the source node has no ip address assigned yet. 1155 */ 1156 if (ipv6_addr_any(saddr)) 1157 goto out; 1158 1159 /* Parse ND options */ 1160 if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) 1161 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1162 1163 if (ndopts.nd_opts_src_lladdr) { 1164 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1165 skb->dev); 1166 if (!lladdr) 1167 goto out; 1168 } 1169 1170 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1); 1171 if (neigh) { 1172 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE, 1173 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1174 NEIGH_UPDATE_F_OVERRIDE| 1175 NEIGH_UPDATE_F_OVERRIDE_ISROUTER, 1176 NDISC_ROUTER_SOLICITATION, &ndopts); 1177 neigh_release(neigh); 1178 reason = SKB_CONSUMED; 1179 } 1180 out: 1181 return reason; 1182 } 1183 1184 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt) 1185 { 1186 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra); 1187 struct sk_buff *skb; 1188 struct nlmsghdr *nlh; 1189 struct nduseroptmsg *ndmsg; 1190 struct net *net = dev_net(ra->dev); 1191 int err; 1192 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg) 1193 + (opt->nd_opt_len << 3)); 1194 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr)); 1195 1196 skb = nlmsg_new(msg_size, GFP_ATOMIC); 1197 if (!skb) { 1198 err = -ENOBUFS; 1199 goto errout; 1200 } 1201 1202 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0); 1203 if (!nlh) { 1204 goto nla_put_failure; 1205 } 1206 1207 ndmsg = nlmsg_data(nlh); 1208 ndmsg->nduseropt_family = AF_INET6; 1209 ndmsg->nduseropt_ifindex = ra->dev->ifindex; 1210 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type; 1211 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code; 1212 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3; 1213 1214 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3); 1215 1216 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr)) 1217 goto nla_put_failure; 1218 nlmsg_end(skb, nlh); 1219 1220 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC); 1221 return; 1222 1223 nla_put_failure: 1224 nlmsg_free(skb); 1225 err = -EMSGSIZE; 1226 errout: 1227 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err); 1228 } 1229 1230 static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb) 1231 { 1232 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb); 1233 bool send_ifinfo_notify = false; 1234 struct neighbour *neigh = NULL; 1235 struct ndisc_options ndopts; 1236 struct fib6_info *rt = NULL; 1237 struct inet6_dev *in6_dev; 1238 struct fib6_table *table; 1239 u32 defrtr_usr_metric; 1240 unsigned int pref = 0; 1241 __u32 old_if_flags; 1242 struct net *net; 1243 SKB_DR(reason); 1244 int lifetime; 1245 int optlen; 1246 1247 __u8 *opt = (__u8 *)(ra_msg + 1); 1248 1249 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) - 1250 sizeof(struct ra_msg); 1251 1252 net_dbg_ratelimited("RA: %s, dev: %s\n", __func__, skb->dev->name); 1253 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1254 net_dbg_ratelimited("RA: source address is not link-local\n"); 1255 return reason; 1256 } 1257 if (optlen < 0) 1258 return SKB_DROP_REASON_PKT_TOO_SMALL; 1259 1260 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1261 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) { 1262 net_dbg_ratelimited("RA: from host or unauthorized router\n"); 1263 return reason; 1264 } 1265 #endif 1266 1267 in6_dev = __in6_dev_get(skb->dev); 1268 if (!in6_dev) { 1269 net_err_ratelimited("RA: can't find inet6 device for %s\n", skb->dev->name); 1270 return reason; 1271 } 1272 1273 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) 1274 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1275 1276 if (!ipv6_accept_ra(in6_dev)) { 1277 net_dbg_ratelimited("RA: %s, did not accept ra for dev: %s\n", __func__, 1278 skb->dev->name); 1279 goto skip_linkparms; 1280 } 1281 1282 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1283 /* skip link-specific parameters from interior routers */ 1284 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1285 net_dbg_ratelimited("RA: %s, nodetype is NODEFAULT, dev: %s\n", __func__, 1286 skb->dev->name); 1287 goto skip_linkparms; 1288 } 1289 #endif 1290 1291 if (in6_dev->if_flags & IF_RS_SENT) { 1292 /* 1293 * flag that an RA was received after an RS was sent 1294 * out on this interface. 1295 */ 1296 in6_dev->if_flags |= IF_RA_RCVD; 1297 } 1298 1299 /* 1300 * Remember the managed/otherconf flags from most recently 1301 * received RA message (RFC 2462) -- yoshfuji 1302 */ 1303 old_if_flags = in6_dev->if_flags; 1304 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED | 1305 IF_RA_OTHERCONF)) | 1306 (ra_msg->icmph.icmp6_addrconf_managed ? 1307 IF_RA_MANAGED : 0) | 1308 (ra_msg->icmph.icmp6_addrconf_other ? 1309 IF_RA_OTHERCONF : 0); 1310 1311 if (old_if_flags != in6_dev->if_flags) 1312 send_ifinfo_notify = true; 1313 1314 if (!READ_ONCE(in6_dev->cnf.accept_ra_defrtr)) { 1315 net_dbg_ratelimited("RA: %s, defrtr is false for dev: %s\n", __func__, 1316 skb->dev->name); 1317 goto skip_defrtr; 1318 } 1319 1320 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); 1321 if (lifetime != 0 && 1322 lifetime < READ_ONCE(in6_dev->cnf.accept_ra_min_lft)) { 1323 net_dbg_ratelimited("RA: router lifetime (%ds) is too short: %s\n", lifetime, 1324 skb->dev->name); 1325 goto skip_defrtr; 1326 } 1327 1328 /* Do not accept RA with source-addr found on local machine unless 1329 * accept_ra_from_local is set to true. 1330 */ 1331 net = dev_net(in6_dev->dev); 1332 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) && 1333 ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) { 1334 net_dbg_ratelimited("RA from local address detected on dev: %s: default router ignored\n", 1335 skb->dev->name); 1336 goto skip_defrtr; 1337 } 1338 1339 #ifdef CONFIG_IPV6_ROUTER_PREF 1340 pref = ra_msg->icmph.icmp6_router_pref; 1341 /* 10b is handled as if it were 00b (medium) */ 1342 if (pref == ICMPV6_ROUTER_PREF_INVALID || 1343 !READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref)) 1344 pref = ICMPV6_ROUTER_PREF_MEDIUM; 1345 #endif 1346 /* routes added from RAs do not use nexthop objects */ 1347 rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev); 1348 if (rt) { 1349 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6, 1350 rt->fib6_nh->fib_nh_dev, NULL, 1351 &ipv6_hdr(skb)->saddr); 1352 if (!neigh) { 1353 net_err_ratelimited("RA: %s got default router without neighbour\n", 1354 __func__); 1355 fib6_info_release(rt); 1356 return reason; 1357 } 1358 } 1359 /* Set default route metric as specified by user */ 1360 defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric; 1361 /* delete the route if lifetime is 0 or if metric needs change */ 1362 if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) { 1363 ip6_del_rt(net, rt, false); 1364 rt = NULL; 1365 } 1366 1367 net_dbg_ratelimited("RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n", rt, lifetime, 1368 defrtr_usr_metric, skb->dev->name); 1369 if (!rt && lifetime) { 1370 net_dbg_ratelimited("RA: adding default router\n"); 1371 1372 if (neigh) 1373 neigh_release(neigh); 1374 1375 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr, 1376 skb->dev, pref, defrtr_usr_metric, 1377 lifetime); 1378 if (!rt) { 1379 net_err_ratelimited("RA: %s failed to add default route\n", __func__); 1380 return reason; 1381 } 1382 1383 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6, 1384 rt->fib6_nh->fib_nh_dev, NULL, 1385 &ipv6_hdr(skb)->saddr); 1386 if (!neigh) { 1387 net_err_ratelimited("RA: %s got default router without neighbour\n", 1388 __func__); 1389 fib6_info_release(rt); 1390 return reason; 1391 } 1392 neigh->flags |= NTF_ROUTER; 1393 } else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) { 1394 struct nl_info nlinfo = { 1395 .nl_net = net, 1396 }; 1397 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 1398 inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_REPLACE); 1399 } 1400 1401 if (rt) { 1402 table = rt->fib6_table; 1403 spin_lock_bh(&table->tb6_lock); 1404 1405 fib6_set_expires(rt, jiffies + (HZ * lifetime)); 1406 fib6_add_gc_list(rt); 1407 1408 spin_unlock_bh(&table->tb6_lock); 1409 } 1410 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) < 256 && 1411 ra_msg->icmph.icmp6_hop_limit) { 1412 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) <= 1413 ra_msg->icmph.icmp6_hop_limit) { 1414 WRITE_ONCE(in6_dev->cnf.hop_limit, 1415 ra_msg->icmph.icmp6_hop_limit); 1416 fib6_metric_set(rt, RTAX_HOPLIMIT, 1417 ra_msg->icmph.icmp6_hop_limit); 1418 } else { 1419 net_dbg_ratelimited("RA: Got route advertisement with lower hop_limit than minimum\n"); 1420 } 1421 } 1422 1423 skip_defrtr: 1424 1425 /* 1426 * Update Reachable Time and Retrans Timer 1427 */ 1428 1429 if (in6_dev->nd_parms) { 1430 unsigned long rtime = ntohl(ra_msg->retrans_timer); 1431 1432 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) { 1433 rtime = (rtime*HZ)/1000; 1434 if (rtime < HZ/100) 1435 rtime = HZ/100; 1436 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime); 1437 in6_dev->tstamp = jiffies; 1438 send_ifinfo_notify = true; 1439 } 1440 1441 rtime = ntohl(ra_msg->reachable_time); 1442 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) { 1443 rtime = (rtime*HZ)/1000; 1444 1445 if (rtime < HZ/10) 1446 rtime = HZ/10; 1447 1448 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) { 1449 NEIGH_VAR_SET(in6_dev->nd_parms, 1450 BASE_REACHABLE_TIME, rtime); 1451 NEIGH_VAR_SET(in6_dev->nd_parms, 1452 GC_STALETIME, 3 * rtime); 1453 neigh_set_reach_time(in6_dev->nd_parms); 1454 in6_dev->tstamp = jiffies; 1455 send_ifinfo_notify = true; 1456 } 1457 } 1458 } 1459 1460 skip_linkparms: 1461 1462 /* 1463 * Process options. 1464 */ 1465 1466 if (!neigh) 1467 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr, 1468 skb->dev, 1); 1469 if (neigh) { 1470 u8 *lladdr = NULL; 1471 if (ndopts.nd_opts_src_lladdr) { 1472 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1473 skb->dev); 1474 if (!lladdr) { 1475 net_dbg_ratelimited("RA: invalid link-layer address length\n"); 1476 goto out; 1477 } 1478 } 1479 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE, 1480 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1481 NEIGH_UPDATE_F_OVERRIDE| 1482 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1483 NEIGH_UPDATE_F_ISROUTER, 1484 NDISC_ROUTER_ADVERTISEMENT, &ndopts); 1485 reason = SKB_CONSUMED; 1486 } 1487 1488 if (!ipv6_accept_ra(in6_dev)) { 1489 net_dbg_ratelimited("RA: %s, accept_ra is false for dev: %s\n", __func__, 1490 skb->dev->name); 1491 goto out; 1492 } 1493 1494 #ifdef CONFIG_IPV6_ROUTE_INFO 1495 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) && 1496 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, 1497 in6_dev->dev, 0)) { 1498 net_dbg_ratelimited("RA from local address detected on dev: %s: router info ignored.\n", 1499 skb->dev->name); 1500 goto skip_routeinfo; 1501 } 1502 1503 if (READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref) && ndopts.nd_opts_ri) { 1504 struct nd_opt_hdr *p; 1505 for (p = ndopts.nd_opts_ri; 1506 p; 1507 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) { 1508 struct route_info *ri = (struct route_info *)p; 1509 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1510 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT && 1511 ri->prefix_len == 0) 1512 continue; 1513 #endif 1514 if (ri->prefix_len == 0 && 1515 !READ_ONCE(in6_dev->cnf.accept_ra_defrtr)) 1516 continue; 1517 if (ri->lifetime != 0 && 1518 ntohl(ri->lifetime) < READ_ONCE(in6_dev->cnf.accept_ra_min_lft)) 1519 continue; 1520 if (ri->prefix_len < READ_ONCE(in6_dev->cnf.accept_ra_rt_info_min_plen)) 1521 continue; 1522 if (ri->prefix_len > READ_ONCE(in6_dev->cnf.accept_ra_rt_info_max_plen)) 1523 continue; 1524 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3, 1525 &ipv6_hdr(skb)->saddr); 1526 } 1527 } 1528 1529 skip_routeinfo: 1530 #endif 1531 1532 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1533 /* skip link-specific ndopts from interior routers */ 1534 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1535 net_dbg_ratelimited("RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n", 1536 __func__, skb->dev->name); 1537 goto out; 1538 } 1539 #endif 1540 1541 if (READ_ONCE(in6_dev->cnf.accept_ra_pinfo) && ndopts.nd_opts_pi) { 1542 struct nd_opt_hdr *p; 1543 for (p = ndopts.nd_opts_pi; 1544 p; 1545 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) { 1546 addrconf_prefix_rcv(skb->dev, (u8 *)p, 1547 (p->nd_opt_len) << 3, 1548 ndopts.nd_opts_src_lladdr != NULL); 1549 } 1550 } 1551 1552 if (ndopts.nd_opts_mtu && READ_ONCE(in6_dev->cnf.accept_ra_mtu)) { 1553 __be32 n; 1554 u32 mtu; 1555 1556 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); 1557 mtu = ntohl(n); 1558 1559 if (READ_ONCE(in6_dev->ra_mtu) != mtu) { 1560 WRITE_ONCE(in6_dev->ra_mtu, mtu); 1561 send_ifinfo_notify = true; 1562 } 1563 1564 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { 1565 net_dbg_ratelimited("RA: invalid mtu: %d\n", mtu); 1566 } else if (READ_ONCE(in6_dev->cnf.mtu6) != mtu) { 1567 WRITE_ONCE(in6_dev->cnf.mtu6, mtu); 1568 fib6_metric_set(rt, RTAX_MTU, mtu); 1569 rt6_mtu_change(skb->dev, mtu); 1570 } 1571 } 1572 1573 if (ndopts.nd_useropts) { 1574 struct nd_opt_hdr *p; 1575 for (p = ndopts.nd_useropts; 1576 p; 1577 p = ndisc_next_useropt(skb->dev, p, 1578 ndopts.nd_useropts_end)) { 1579 ndisc_ra_useropt(skb, p); 1580 } 1581 } 1582 1583 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { 1584 net_dbg_ratelimited("RA: invalid RA options\n"); 1585 } 1586 out: 1587 /* Send a notify if RA changed managed/otherconf flags or 1588 * timer settings or ra_mtu value 1589 */ 1590 if (send_ifinfo_notify) 1591 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1592 1593 fib6_info_release(rt); 1594 if (neigh) 1595 neigh_release(neigh); 1596 return reason; 1597 } 1598 1599 static enum skb_drop_reason ndisc_redirect_rcv(struct sk_buff *skb) 1600 { 1601 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb); 1602 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 1603 offsetof(struct rd_msg, opt)); 1604 struct ndisc_options ndopts; 1605 SKB_DR(reason); 1606 u8 *hdr; 1607 1608 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1609 switch (skb->ndisc_nodetype) { 1610 case NDISC_NODETYPE_HOST: 1611 case NDISC_NODETYPE_NODEFAULT: 1612 net_dbg_ratelimited("Redirect: from host or unauthorized router\n"); 1613 return reason; 1614 } 1615 #endif 1616 1617 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1618 net_dbg_ratelimited("Redirect: source address is not link-local\n"); 1619 return reason; 1620 } 1621 1622 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts)) 1623 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1624 1625 if (!ndopts.nd_opts_rh) { 1626 ip6_redirect_no_header(skb, dev_net(skb->dev), 1627 skb->dev->ifindex); 1628 return reason; 1629 } 1630 1631 hdr = (u8 *)ndopts.nd_opts_rh; 1632 hdr += 8; 1633 if (!pskb_pull(skb, hdr - skb_transport_header(skb))) 1634 return SKB_DROP_REASON_PKT_TOO_SMALL; 1635 1636 return icmpv6_notify(skb, NDISC_REDIRECT, 0, 0); 1637 } 1638 1639 static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb, 1640 struct sk_buff *orig_skb, 1641 int rd_len) 1642 { 1643 u8 *opt = skb_put(skb, rd_len); 1644 1645 memset(opt, 0, 8); 1646 *(opt++) = ND_OPT_REDIRECT_HDR; 1647 *(opt++) = (rd_len >> 3); 1648 opt += 6; 1649 1650 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt, 1651 rd_len - 8); 1652 } 1653 1654 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target) 1655 { 1656 struct net_device *dev = skb->dev; 1657 struct net *net = dev_net_rcu(dev); 1658 struct sock *sk = net->ipv6.ndisc_sk; 1659 int optlen = 0; 1660 struct inet_peer *peer; 1661 struct sk_buff *buff; 1662 struct rd_msg *msg; 1663 struct in6_addr saddr_buf; 1664 struct rt6_info *rt; 1665 struct dst_entry *dst; 1666 struct flowi6 fl6; 1667 int rd_len; 1668 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL, 1669 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL; 1670 bool ret; 1671 1672 if (netif_is_l3_master(dev)) { 1673 dev = dev_get_by_index_rcu(net, IPCB(skb)->iif); 1674 if (!dev) 1675 return; 1676 } 1677 1678 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) { 1679 net_dbg_ratelimited("Redirect: no link-local address on %s\n", dev->name); 1680 return; 1681 } 1682 1683 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) && 1684 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1685 net_dbg_ratelimited("Redirect: target address is not link-local unicast\n"); 1686 return; 1687 } 1688 1689 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT, 1690 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex); 1691 1692 dst = ip6_route_output(net, NULL, &fl6); 1693 if (dst->error) { 1694 dst_release(dst); 1695 return; 1696 } 1697 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); 1698 if (IS_ERR(dst)) 1699 return; 1700 1701 rt = dst_rt6_info(dst); 1702 1703 if (rt->rt6i_flags & RTF_GATEWAY) { 1704 net_dbg_ratelimited("Redirect: destination is not a neighbour\n"); 1705 goto release; 1706 } 1707 1708 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr); 1709 ret = inet_peer_xrlim_allow(peer, 1*HZ); 1710 1711 if (!ret) 1712 goto release; 1713 1714 if (dev->addr_len) { 1715 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target); 1716 if (!neigh) { 1717 net_dbg_ratelimited("Redirect: no neigh for target address\n"); 1718 goto release; 1719 } 1720 1721 read_lock_bh(&neigh->lock); 1722 if (neigh->nud_state & NUD_VALID) { 1723 memcpy(ha_buf, neigh->ha, dev->addr_len); 1724 read_unlock_bh(&neigh->lock); 1725 ha = ha_buf; 1726 optlen += ndisc_redirect_opt_addr_space(dev, neigh, 1727 ops_data_buf, 1728 &ops_data); 1729 } else 1730 read_unlock_bh(&neigh->lock); 1731 1732 neigh_release(neigh); 1733 } 1734 1735 rd_len = min_t(unsigned int, 1736 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen, 1737 skb->len + 8); 1738 rd_len &= ~0x7; 1739 optlen += rd_len; 1740 1741 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 1742 if (!buff) 1743 goto release; 1744 1745 msg = skb_put(buff, sizeof(*msg)); 1746 *msg = (struct rd_msg) { 1747 .icmph = { 1748 .icmp6_type = NDISC_REDIRECT, 1749 }, 1750 .target = *target, 1751 .dest = ipv6_hdr(skb)->daddr, 1752 }; 1753 1754 /* 1755 * include target_address option 1756 */ 1757 1758 if (ha) 1759 ndisc_fill_redirect_addr_option(buff, ha, ops_data); 1760 1761 /* 1762 * build redirect option and copy skb over to the new packet. 1763 */ 1764 1765 if (rd_len) 1766 ndisc_fill_redirect_hdr_option(buff, skb, rd_len); 1767 1768 skb_dst_set(buff, dst); 1769 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf); 1770 return; 1771 1772 release: 1773 dst_release(dst); 1774 } 1775 1776 static void pndisc_redo(struct sk_buff *skb) 1777 { 1778 enum skb_drop_reason reason = ndisc_recv_ns(skb); 1779 1780 kfree_skb_reason(skb, reason); 1781 } 1782 1783 static int ndisc_is_multicast(const void *pkey) 1784 { 1785 return ipv6_addr_is_multicast((struct in6_addr *)pkey); 1786 } 1787 1788 static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb) 1789 { 1790 struct inet6_dev *idev = __in6_dev_get(skb->dev); 1791 1792 if (!idev) 1793 return true; 1794 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED && 1795 READ_ONCE(idev->cnf.suppress_frag_ndisc)) { 1796 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n"); 1797 return true; 1798 } 1799 return false; 1800 } 1801 1802 enum skb_drop_reason ndisc_rcv(struct sk_buff *skb) 1803 { 1804 struct nd_msg *msg; 1805 SKB_DR(reason); 1806 1807 if (ndisc_suppress_frag_ndisc(skb)) 1808 return SKB_DROP_REASON_IPV6_NDISC_FRAG; 1809 1810 if (skb_linearize(skb)) 1811 return SKB_DROP_REASON_NOMEM; 1812 1813 msg = (struct nd_msg *)skb_transport_header(skb); 1814 1815 __skb_push(skb, skb->data - skb_transport_header(skb)); 1816 1817 if (ipv6_hdr(skb)->hop_limit != 255) { 1818 net_dbg_ratelimited("NDISC: invalid hop-limit: %d\n", ipv6_hdr(skb)->hop_limit); 1819 return SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT; 1820 } 1821 1822 if (msg->icmph.icmp6_code != 0) { 1823 net_dbg_ratelimited("NDISC: invalid ICMPv6 code: %d\n", msg->icmph.icmp6_code); 1824 return SKB_DROP_REASON_IPV6_NDISC_BAD_CODE; 1825 } 1826 1827 switch (msg->icmph.icmp6_type) { 1828 case NDISC_NEIGHBOUR_SOLICITATION: 1829 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 1830 reason = ndisc_recv_ns(skb); 1831 break; 1832 1833 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1834 reason = ndisc_recv_na(skb); 1835 break; 1836 1837 case NDISC_ROUTER_SOLICITATION: 1838 reason = ndisc_recv_rs(skb); 1839 break; 1840 1841 case NDISC_ROUTER_ADVERTISEMENT: 1842 reason = ndisc_router_discovery(skb); 1843 break; 1844 1845 case NDISC_REDIRECT: 1846 reason = ndisc_redirect_rcv(skb); 1847 break; 1848 } 1849 1850 return reason; 1851 } 1852 1853 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1854 { 1855 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1856 struct netdev_notifier_change_info *change_info; 1857 struct net *net = dev_net(dev); 1858 struct inet6_dev *idev; 1859 bool evict_nocarrier; 1860 1861 switch (event) { 1862 case NETDEV_CHANGEADDR: 1863 neigh_changeaddr(&nd_tbl, dev); 1864 fib6_run_gc(0, net, false); 1865 fallthrough; 1866 case NETDEV_UP: 1867 idev = in6_dev_get(dev); 1868 if (!idev) 1869 break; 1870 if (READ_ONCE(idev->cnf.ndisc_notify) || 1871 READ_ONCE(net->ipv6.devconf_all->ndisc_notify)) 1872 ndisc_send_unsol_na(dev); 1873 in6_dev_put(idev); 1874 break; 1875 case NETDEV_CHANGE: 1876 idev = in6_dev_get(dev); 1877 if (!idev) 1878 evict_nocarrier = true; 1879 else { 1880 evict_nocarrier = READ_ONCE(idev->cnf.ndisc_evict_nocarrier) && 1881 READ_ONCE(net->ipv6.devconf_all->ndisc_evict_nocarrier); 1882 in6_dev_put(idev); 1883 } 1884 1885 change_info = ptr; 1886 if (change_info->flags_changed & IFF_NOARP) 1887 neigh_changeaddr(&nd_tbl, dev); 1888 if (evict_nocarrier && !netif_carrier_ok(dev)) 1889 neigh_carrier_down(&nd_tbl, dev); 1890 break; 1891 case NETDEV_DOWN: 1892 neigh_ifdown(&nd_tbl, dev); 1893 fib6_run_gc(0, net, false); 1894 break; 1895 case NETDEV_NOTIFY_PEERS: 1896 ndisc_send_unsol_na(dev); 1897 break; 1898 default: 1899 break; 1900 } 1901 1902 return NOTIFY_DONE; 1903 } 1904 1905 static struct notifier_block ndisc_netdev_notifier = { 1906 .notifier_call = ndisc_netdev_event, 1907 .priority = ADDRCONF_NOTIFY_PRIORITY - 5, 1908 }; 1909 1910 #ifdef CONFIG_SYSCTL 1911 static void ndisc_warn_deprecated_sysctl(const struct ctl_table *ctl, 1912 const char *func, const char *dev_name) 1913 { 1914 static char warncomm[TASK_COMM_LEN]; 1915 static int warned; 1916 if (strcmp(warncomm, current->comm) && warned < 5) { 1917 strscpy(warncomm, current->comm); 1918 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n", 1919 warncomm, func, 1920 dev_name, ctl->procname, 1921 dev_name, ctl->procname); 1922 warned++; 1923 } 1924 } 1925 1926 int ndisc_ifinfo_sysctl_change(const struct ctl_table *ctl, int write, void *buffer, 1927 size_t *lenp, loff_t *ppos) 1928 { 1929 struct net_device *dev = ctl->extra1; 1930 struct inet6_dev *idev; 1931 int ret; 1932 1933 if ((strcmp(ctl->procname, "retrans_time") == 0) || 1934 (strcmp(ctl->procname, "base_reachable_time") == 0)) 1935 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default"); 1936 1937 if (strcmp(ctl->procname, "retrans_time") == 0) 1938 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos); 1939 1940 else if (strcmp(ctl->procname, "base_reachable_time") == 0) 1941 ret = neigh_proc_dointvec_jiffies(ctl, write, 1942 buffer, lenp, ppos); 1943 1944 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) || 1945 (strcmp(ctl->procname, "base_reachable_time_ms") == 0)) 1946 ret = neigh_proc_dointvec_ms_jiffies(ctl, write, 1947 buffer, lenp, ppos); 1948 else 1949 ret = -1; 1950 1951 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) { 1952 if (ctl->data == NEIGH_VAR_PTR(idev->nd_parms, BASE_REACHABLE_TIME)) 1953 neigh_set_reach_time(idev->nd_parms); 1954 1955 WRITE_ONCE(idev->tstamp, jiffies); 1956 inet6_ifinfo_notify(RTM_NEWLINK, idev); 1957 in6_dev_put(idev); 1958 } 1959 return ret; 1960 } 1961 1962 1963 #endif 1964 1965 static int __net_init ndisc_net_init(struct net *net) 1966 { 1967 struct ipv6_pinfo *np; 1968 struct sock *sk; 1969 int err; 1970 1971 err = inet_ctl_sock_create(&sk, PF_INET6, 1972 SOCK_RAW, IPPROTO_ICMPV6, net); 1973 if (err < 0) { 1974 net_err_ratelimited("NDISC: Failed to initialize the control socket (err %d)\n", 1975 err); 1976 return err; 1977 } 1978 1979 net->ipv6.ndisc_sk = sk; 1980 1981 np = inet6_sk(sk); 1982 np->hop_limit = 255; 1983 /* Do not loopback ndisc messages */ 1984 inet6_clear_bit(MC6_LOOP, sk); 1985 1986 return 0; 1987 } 1988 1989 static void __net_exit ndisc_net_exit(struct net *net) 1990 { 1991 inet_ctl_sock_destroy(net->ipv6.ndisc_sk); 1992 } 1993 1994 static struct pernet_operations ndisc_net_ops = { 1995 .init = ndisc_net_init, 1996 .exit = ndisc_net_exit, 1997 }; 1998 1999 int __init ndisc_init(void) 2000 { 2001 int err; 2002 2003 err = register_pernet_subsys(&ndisc_net_ops); 2004 if (err) 2005 return err; 2006 /* 2007 * Initialize the neighbour table 2008 */ 2009 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl); 2010 2011 #ifdef CONFIG_SYSCTL 2012 err = neigh_sysctl_register(NULL, &nd_tbl.parms, 2013 ndisc_ifinfo_sysctl_change); 2014 if (err) 2015 goto out_unregister_pernet; 2016 out: 2017 #endif 2018 return err; 2019 2020 #ifdef CONFIG_SYSCTL 2021 out_unregister_pernet: 2022 unregister_pernet_subsys(&ndisc_net_ops); 2023 goto out; 2024 #endif 2025 } 2026 2027 int __init ndisc_late_init(void) 2028 { 2029 return register_netdevice_notifier(&ndisc_netdev_notifier); 2030 } 2031 2032 void ndisc_late_cleanup(void) 2033 { 2034 unregister_netdevice_notifier(&ndisc_netdev_notifier); 2035 } 2036 2037 void ndisc_cleanup(void) 2038 { 2039 #ifdef CONFIG_SYSCTL 2040 neigh_sysctl_unregister(&nd_tbl.parms); 2041 #endif 2042 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl); 2043 unregister_pernet_subsys(&ndisc_net_ops); 2044 } 2045