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 } 579 580 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 ndmsg->nduseropt_pad1 = 0; 1213 ndmsg->nduseropt_pad2 = 0; 1214 ndmsg->nduseropt_pad3 = 0; 1215 1216 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3); 1217 1218 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr)) 1219 goto nla_put_failure; 1220 nlmsg_end(skb, nlh); 1221 1222 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC); 1223 return; 1224 1225 nla_put_failure: 1226 nlmsg_free(skb); 1227 err = -EMSGSIZE; 1228 errout: 1229 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err); 1230 } 1231 1232 static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb) 1233 { 1234 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb); 1235 bool send_ifinfo_notify = false; 1236 struct neighbour *neigh = NULL; 1237 struct ndisc_options ndopts; 1238 struct fib6_info *rt = NULL; 1239 struct inet6_dev *in6_dev; 1240 struct fib6_table *table; 1241 u32 defrtr_usr_metric; 1242 unsigned int pref = 0; 1243 __u32 old_if_flags; 1244 struct net *net; 1245 SKB_DR(reason); 1246 int lifetime; 1247 int optlen; 1248 1249 __u8 *opt = (__u8 *)(ra_msg + 1); 1250 1251 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) - 1252 sizeof(struct ra_msg); 1253 1254 net_dbg_ratelimited("RA: %s, dev: %s\n", __func__, skb->dev->name); 1255 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1256 net_dbg_ratelimited("RA: source address is not link-local\n"); 1257 return reason; 1258 } 1259 if (optlen < 0) 1260 return SKB_DROP_REASON_PKT_TOO_SMALL; 1261 1262 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1263 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) { 1264 net_dbg_ratelimited("RA: from host or unauthorized router\n"); 1265 return reason; 1266 } 1267 #endif 1268 1269 in6_dev = __in6_dev_get(skb->dev); 1270 if (!in6_dev) { 1271 net_err_ratelimited("RA: can't find inet6 device for %s\n", skb->dev->name); 1272 return reason; 1273 } 1274 1275 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) 1276 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1277 1278 if (!ipv6_accept_ra(in6_dev)) { 1279 net_dbg_ratelimited("RA: %s, did not accept ra for dev: %s\n", __func__, 1280 skb->dev->name); 1281 goto skip_linkparms; 1282 } 1283 1284 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1285 /* skip link-specific parameters from interior routers */ 1286 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1287 net_dbg_ratelimited("RA: %s, nodetype is NODEFAULT, dev: %s\n", __func__, 1288 skb->dev->name); 1289 goto skip_linkparms; 1290 } 1291 #endif 1292 1293 if (in6_dev->if_flags & IF_RS_SENT) { 1294 /* 1295 * flag that an RA was received after an RS was sent 1296 * out on this interface. 1297 */ 1298 in6_dev->if_flags |= IF_RA_RCVD; 1299 } 1300 1301 /* 1302 * Remember the managed/otherconf flags from most recently 1303 * received RA message (RFC 2462) -- yoshfuji 1304 */ 1305 old_if_flags = in6_dev->if_flags; 1306 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED | 1307 IF_RA_OTHERCONF)) | 1308 (ra_msg->icmph.icmp6_addrconf_managed ? 1309 IF_RA_MANAGED : 0) | 1310 (ra_msg->icmph.icmp6_addrconf_other ? 1311 IF_RA_OTHERCONF : 0); 1312 1313 if (old_if_flags != in6_dev->if_flags) 1314 send_ifinfo_notify = true; 1315 1316 if (!READ_ONCE(in6_dev->cnf.accept_ra_defrtr)) { 1317 net_dbg_ratelimited("RA: %s, defrtr is false for dev: %s\n", __func__, 1318 skb->dev->name); 1319 goto skip_defrtr; 1320 } 1321 1322 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); 1323 if (lifetime != 0 && 1324 lifetime < READ_ONCE(in6_dev->cnf.accept_ra_min_lft)) { 1325 net_dbg_ratelimited("RA: router lifetime (%ds) is too short: %s\n", lifetime, 1326 skb->dev->name); 1327 goto skip_defrtr; 1328 } 1329 1330 /* Do not accept RA with source-addr found on local machine unless 1331 * accept_ra_from_local is set to true. 1332 */ 1333 net = dev_net(in6_dev->dev); 1334 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) && 1335 ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) { 1336 net_dbg_ratelimited("RA from local address detected on dev: %s: default router ignored\n", 1337 skb->dev->name); 1338 goto skip_defrtr; 1339 } 1340 1341 #ifdef CONFIG_IPV6_ROUTER_PREF 1342 pref = ra_msg->icmph.icmp6_router_pref; 1343 /* 10b is handled as if it were 00b (medium) */ 1344 if (pref == ICMPV6_ROUTER_PREF_INVALID || 1345 !READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref)) 1346 pref = ICMPV6_ROUTER_PREF_MEDIUM; 1347 #endif 1348 /* routes added from RAs do not use nexthop objects */ 1349 rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev); 1350 if (rt) { 1351 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6, 1352 rt->fib6_nh->fib_nh_dev, NULL, 1353 &ipv6_hdr(skb)->saddr); 1354 if (!neigh) { 1355 net_err_ratelimited("RA: %s got default router without neighbour\n", 1356 __func__); 1357 fib6_info_release(rt); 1358 return reason; 1359 } 1360 } 1361 /* Set default route metric as specified by user */ 1362 defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric; 1363 /* delete the route if lifetime is 0 or if metric needs change */ 1364 if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) { 1365 ip6_del_rt(net, rt, false); 1366 rt = NULL; 1367 } 1368 1369 net_dbg_ratelimited("RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n", rt, lifetime, 1370 defrtr_usr_metric, skb->dev->name); 1371 if (!rt && lifetime) { 1372 net_dbg_ratelimited("RA: adding default router\n"); 1373 1374 if (neigh) 1375 neigh_release(neigh); 1376 1377 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr, 1378 skb->dev, pref, defrtr_usr_metric, 1379 lifetime); 1380 if (!rt) { 1381 net_err_ratelimited("RA: %s failed to add default route\n", __func__); 1382 return reason; 1383 } 1384 1385 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6, 1386 rt->fib6_nh->fib_nh_dev, NULL, 1387 &ipv6_hdr(skb)->saddr); 1388 if (!neigh) { 1389 net_err_ratelimited("RA: %s got default router without neighbour\n", 1390 __func__); 1391 fib6_info_release(rt); 1392 return reason; 1393 } 1394 neigh->flags |= NTF_ROUTER; 1395 } else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) { 1396 struct nl_info nlinfo = { 1397 .nl_net = net, 1398 }; 1399 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 1400 inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_REPLACE); 1401 } 1402 1403 if (rt) { 1404 table = rt->fib6_table; 1405 spin_lock_bh(&table->tb6_lock); 1406 1407 fib6_set_expires(rt, jiffies + (HZ * lifetime)); 1408 fib6_add_gc_list(rt); 1409 1410 spin_unlock_bh(&table->tb6_lock); 1411 } 1412 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) < 256 && 1413 ra_msg->icmph.icmp6_hop_limit) { 1414 if (READ_ONCE(in6_dev->cnf.accept_ra_min_hop_limit) <= 1415 ra_msg->icmph.icmp6_hop_limit) { 1416 WRITE_ONCE(in6_dev->cnf.hop_limit, 1417 ra_msg->icmph.icmp6_hop_limit); 1418 fib6_metric_set(rt, RTAX_HOPLIMIT, 1419 ra_msg->icmph.icmp6_hop_limit); 1420 } else { 1421 net_dbg_ratelimited("RA: Got route advertisement with lower hop_limit than minimum\n"); 1422 } 1423 } 1424 1425 skip_defrtr: 1426 1427 /* 1428 * Update Reachable Time and Retrans Timer 1429 */ 1430 1431 if (in6_dev->nd_parms) { 1432 unsigned long rtime = ntohl(ra_msg->retrans_timer); 1433 1434 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) { 1435 rtime = (rtime*HZ)/1000; 1436 if (rtime < HZ/100) 1437 rtime = HZ/100; 1438 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime); 1439 in6_dev->tstamp = jiffies; 1440 send_ifinfo_notify = true; 1441 } 1442 1443 rtime = ntohl(ra_msg->reachable_time); 1444 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) { 1445 rtime = (rtime*HZ)/1000; 1446 1447 if (rtime < HZ/10) 1448 rtime = HZ/10; 1449 1450 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) { 1451 NEIGH_VAR_SET(in6_dev->nd_parms, 1452 BASE_REACHABLE_TIME, rtime); 1453 NEIGH_VAR_SET(in6_dev->nd_parms, 1454 GC_STALETIME, 3 * rtime); 1455 neigh_set_reach_time(in6_dev->nd_parms); 1456 in6_dev->tstamp = jiffies; 1457 send_ifinfo_notify = true; 1458 } 1459 } 1460 } 1461 1462 skip_linkparms: 1463 1464 /* 1465 * Process options. 1466 */ 1467 1468 if (!neigh) 1469 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr, 1470 skb->dev, 1); 1471 if (neigh) { 1472 u8 *lladdr = NULL; 1473 if (ndopts.nd_opts_src_lladdr) { 1474 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1475 skb->dev); 1476 if (!lladdr) { 1477 net_dbg_ratelimited("RA: invalid link-layer address length\n"); 1478 goto out; 1479 } 1480 } 1481 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE, 1482 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1483 NEIGH_UPDATE_F_OVERRIDE| 1484 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1485 NEIGH_UPDATE_F_ISROUTER, 1486 NDISC_ROUTER_ADVERTISEMENT, &ndopts); 1487 reason = SKB_CONSUMED; 1488 } 1489 1490 if (!ipv6_accept_ra(in6_dev)) { 1491 net_dbg_ratelimited("RA: %s, accept_ra is false for dev: %s\n", __func__, 1492 skb->dev->name); 1493 goto out; 1494 } 1495 1496 #ifdef CONFIG_IPV6_ROUTE_INFO 1497 if (!READ_ONCE(in6_dev->cnf.accept_ra_from_local) && 1498 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, 1499 in6_dev->dev, 0)) { 1500 net_dbg_ratelimited("RA from local address detected on dev: %s: router info ignored.\n", 1501 skb->dev->name); 1502 goto skip_routeinfo; 1503 } 1504 1505 if (READ_ONCE(in6_dev->cnf.accept_ra_rtr_pref) && ndopts.nd_opts_ri) { 1506 struct nd_opt_hdr *p; 1507 for (p = ndopts.nd_opts_ri; 1508 p; 1509 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) { 1510 struct route_info *ri = (struct route_info *)p; 1511 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1512 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT && 1513 ri->prefix_len == 0) 1514 continue; 1515 #endif 1516 if (ri->prefix_len == 0 && 1517 !READ_ONCE(in6_dev->cnf.accept_ra_defrtr)) 1518 continue; 1519 if (ri->lifetime != 0 && 1520 ntohl(ri->lifetime) < READ_ONCE(in6_dev->cnf.accept_ra_min_lft)) 1521 continue; 1522 if (ri->prefix_len < READ_ONCE(in6_dev->cnf.accept_ra_rt_info_min_plen)) 1523 continue; 1524 if (ri->prefix_len > READ_ONCE(in6_dev->cnf.accept_ra_rt_info_max_plen)) 1525 continue; 1526 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3, 1527 &ipv6_hdr(skb)->saddr); 1528 } 1529 } 1530 1531 skip_routeinfo: 1532 #endif 1533 1534 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1535 /* skip link-specific ndopts from interior routers */ 1536 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1537 net_dbg_ratelimited("RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n", 1538 __func__, skb->dev->name); 1539 goto out; 1540 } 1541 #endif 1542 1543 if (READ_ONCE(in6_dev->cnf.accept_ra_pinfo) && ndopts.nd_opts_pi) { 1544 struct nd_opt_hdr *p; 1545 for (p = ndopts.nd_opts_pi; 1546 p; 1547 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) { 1548 addrconf_prefix_rcv(skb->dev, (u8 *)p, 1549 (p->nd_opt_len) << 3, 1550 ndopts.nd_opts_src_lladdr != NULL); 1551 } 1552 } 1553 1554 if (ndopts.nd_opts_mtu && READ_ONCE(in6_dev->cnf.accept_ra_mtu)) { 1555 __be32 n; 1556 u32 mtu; 1557 1558 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); 1559 mtu = ntohl(n); 1560 1561 if (READ_ONCE(in6_dev->ra_mtu) != mtu) { 1562 WRITE_ONCE(in6_dev->ra_mtu, mtu); 1563 send_ifinfo_notify = true; 1564 } 1565 1566 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { 1567 net_dbg_ratelimited("RA: invalid mtu: %d\n", mtu); 1568 } else if (READ_ONCE(in6_dev->cnf.mtu6) != mtu) { 1569 WRITE_ONCE(in6_dev->cnf.mtu6, mtu); 1570 fib6_metric_set(rt, RTAX_MTU, mtu); 1571 rt6_mtu_change(skb->dev, mtu); 1572 } 1573 } 1574 1575 if (ndopts.nd_useropts) { 1576 struct nd_opt_hdr *p; 1577 for (p = ndopts.nd_useropts; 1578 p; 1579 p = ndisc_next_useropt(skb->dev, p, 1580 ndopts.nd_useropts_end)) { 1581 ndisc_ra_useropt(skb, p); 1582 } 1583 } 1584 1585 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { 1586 net_dbg_ratelimited("RA: invalid RA options\n"); 1587 } 1588 out: 1589 /* Send a notify if RA changed managed/otherconf flags or 1590 * timer settings or ra_mtu value 1591 */ 1592 if (send_ifinfo_notify) 1593 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1594 1595 fib6_info_release(rt); 1596 if (neigh) 1597 neigh_release(neigh); 1598 return reason; 1599 } 1600 1601 static enum skb_drop_reason ndisc_redirect_rcv(struct sk_buff *skb) 1602 { 1603 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb); 1604 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 1605 offsetof(struct rd_msg, opt)); 1606 struct ndisc_options ndopts; 1607 SKB_DR(reason); 1608 u8 *hdr; 1609 1610 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1611 switch (skb->ndisc_nodetype) { 1612 case NDISC_NODETYPE_HOST: 1613 case NDISC_NODETYPE_NODEFAULT: 1614 net_dbg_ratelimited("Redirect: from host or unauthorized router\n"); 1615 return reason; 1616 } 1617 #endif 1618 1619 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1620 net_dbg_ratelimited("Redirect: source address is not link-local\n"); 1621 return reason; 1622 } 1623 1624 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts)) 1625 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1626 1627 if (!ndopts.nd_opts_rh) { 1628 ip6_redirect_no_header(skb, dev_net(skb->dev), 1629 skb->dev->ifindex); 1630 return reason; 1631 } 1632 1633 hdr = (u8 *)ndopts.nd_opts_rh; 1634 hdr += 8; 1635 if (!pskb_pull(skb, hdr - skb_transport_header(skb))) 1636 return SKB_DROP_REASON_PKT_TOO_SMALL; 1637 1638 return icmpv6_notify(skb, NDISC_REDIRECT, 0, 0); 1639 } 1640 1641 static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb, 1642 struct sk_buff *orig_skb, 1643 int rd_len) 1644 { 1645 u8 *opt = skb_put(skb, rd_len); 1646 1647 memset(opt, 0, 8); 1648 *(opt++) = ND_OPT_REDIRECT_HDR; 1649 *(opt++) = (rd_len >> 3); 1650 opt += 6; 1651 1652 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt, 1653 rd_len - 8); 1654 } 1655 1656 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target) 1657 { 1658 struct net_device *dev = skb->dev; 1659 struct net *net = dev_net_rcu(dev); 1660 struct sock *sk = net->ipv6.ndisc_sk; 1661 int optlen = 0; 1662 struct inet_peer *peer; 1663 struct sk_buff *buff; 1664 struct rd_msg *msg; 1665 struct in6_addr saddr_buf; 1666 struct rt6_info *rt; 1667 struct dst_entry *dst; 1668 struct flowi6 fl6; 1669 int rd_len; 1670 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL, 1671 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL; 1672 bool ret; 1673 1674 if (netif_is_l3_master(dev)) { 1675 dev = dev_get_by_index_rcu(net, IPCB(skb)->iif); 1676 if (!dev) 1677 return; 1678 } 1679 1680 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) { 1681 net_dbg_ratelimited("Redirect: no link-local address on %s\n", dev->name); 1682 return; 1683 } 1684 1685 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) && 1686 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1687 net_dbg_ratelimited("Redirect: target address is not link-local unicast\n"); 1688 return; 1689 } 1690 1691 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT, 1692 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex); 1693 1694 dst = ip6_route_output(net, NULL, &fl6); 1695 if (dst->error) { 1696 dst_release(dst); 1697 return; 1698 } 1699 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); 1700 if (IS_ERR(dst)) 1701 return; 1702 1703 rt = dst_rt6_info(dst); 1704 1705 if (rt->rt6i_flags & RTF_GATEWAY) { 1706 net_dbg_ratelimited("Redirect: destination is not a neighbour\n"); 1707 goto release; 1708 } 1709 1710 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr); 1711 ret = inet_peer_xrlim_allow(peer, 1*HZ); 1712 1713 if (!ret) 1714 goto release; 1715 1716 if (dev->addr_len) { 1717 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target); 1718 if (!neigh) { 1719 net_dbg_ratelimited("Redirect: no neigh for target address\n"); 1720 goto release; 1721 } 1722 1723 read_lock_bh(&neigh->lock); 1724 if (neigh->nud_state & NUD_VALID) { 1725 memcpy(ha_buf, neigh->ha, dev->addr_len); 1726 read_unlock_bh(&neigh->lock); 1727 ha = ha_buf; 1728 optlen += ndisc_redirect_opt_addr_space(dev, neigh, 1729 ops_data_buf, 1730 &ops_data); 1731 } else 1732 read_unlock_bh(&neigh->lock); 1733 1734 neigh_release(neigh); 1735 } 1736 1737 rd_len = min_t(unsigned int, 1738 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen, 1739 skb->len + 8); 1740 rd_len &= ~0x7; 1741 optlen += rd_len; 1742 1743 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 1744 if (!buff) 1745 goto release; 1746 1747 msg = skb_put(buff, sizeof(*msg)); 1748 *msg = (struct rd_msg) { 1749 .icmph = { 1750 .icmp6_type = NDISC_REDIRECT, 1751 }, 1752 .target = *target, 1753 .dest = ipv6_hdr(skb)->daddr, 1754 }; 1755 1756 /* 1757 * include target_address option 1758 */ 1759 1760 if (ha) 1761 ndisc_fill_redirect_addr_option(buff, ha, ops_data); 1762 1763 /* 1764 * build redirect option and copy skb over to the new packet. 1765 */ 1766 1767 if (rd_len) 1768 ndisc_fill_redirect_hdr_option(buff, skb, rd_len); 1769 1770 skb_dst_set(buff, dst); 1771 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf); 1772 return; 1773 1774 release: 1775 dst_release(dst); 1776 } 1777 1778 static void pndisc_redo(struct sk_buff *skb) 1779 { 1780 enum skb_drop_reason reason = ndisc_recv_ns(skb); 1781 1782 kfree_skb_reason(skb, reason); 1783 } 1784 1785 static int ndisc_is_multicast(const void *pkey) 1786 { 1787 return ipv6_addr_is_multicast((struct in6_addr *)pkey); 1788 } 1789 1790 static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb) 1791 { 1792 struct inet6_dev *idev = __in6_dev_get(skb->dev); 1793 1794 if (!idev) 1795 return true; 1796 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED && 1797 READ_ONCE(idev->cnf.suppress_frag_ndisc)) { 1798 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n"); 1799 return true; 1800 } 1801 return false; 1802 } 1803 1804 enum skb_drop_reason ndisc_rcv(struct sk_buff *skb) 1805 { 1806 struct nd_msg *msg; 1807 SKB_DR(reason); 1808 1809 if (ndisc_suppress_frag_ndisc(skb)) 1810 return SKB_DROP_REASON_IPV6_NDISC_FRAG; 1811 1812 if (skb_linearize(skb)) 1813 return SKB_DROP_REASON_NOMEM; 1814 1815 msg = (struct nd_msg *)skb_transport_header(skb); 1816 1817 __skb_push(skb, skb->data - skb_transport_header(skb)); 1818 1819 if (ipv6_hdr(skb)->hop_limit != 255) { 1820 net_dbg_ratelimited("NDISC: invalid hop-limit: %d\n", ipv6_hdr(skb)->hop_limit); 1821 return SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT; 1822 } 1823 1824 if (msg->icmph.icmp6_code != 0) { 1825 net_dbg_ratelimited("NDISC: invalid ICMPv6 code: %d\n", msg->icmph.icmp6_code); 1826 return SKB_DROP_REASON_IPV6_NDISC_BAD_CODE; 1827 } 1828 1829 switch (msg->icmph.icmp6_type) { 1830 case NDISC_NEIGHBOUR_SOLICITATION: 1831 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 1832 reason = ndisc_recv_ns(skb); 1833 break; 1834 1835 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1836 reason = ndisc_recv_na(skb); 1837 break; 1838 1839 case NDISC_ROUTER_SOLICITATION: 1840 reason = ndisc_recv_rs(skb); 1841 break; 1842 1843 case NDISC_ROUTER_ADVERTISEMENT: 1844 reason = ndisc_router_discovery(skb); 1845 break; 1846 1847 case NDISC_REDIRECT: 1848 reason = ndisc_redirect_rcv(skb); 1849 break; 1850 } 1851 1852 return reason; 1853 } 1854 1855 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1856 { 1857 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1858 struct netdev_notifier_change_info *change_info; 1859 struct net *net = dev_net(dev); 1860 struct inet6_dev *idev; 1861 bool evict_nocarrier; 1862 1863 switch (event) { 1864 case NETDEV_CHANGEADDR: 1865 neigh_changeaddr(&nd_tbl, dev); 1866 fib6_run_gc(0, net, false); 1867 fallthrough; 1868 case NETDEV_UP: 1869 idev = in6_dev_get(dev); 1870 if (!idev) 1871 break; 1872 if (READ_ONCE(idev->cnf.ndisc_notify) || 1873 READ_ONCE(net->ipv6.devconf_all->ndisc_notify)) 1874 ndisc_send_unsol_na(dev); 1875 in6_dev_put(idev); 1876 break; 1877 case NETDEV_CHANGE: 1878 idev = in6_dev_get(dev); 1879 if (!idev) 1880 evict_nocarrier = true; 1881 else { 1882 evict_nocarrier = READ_ONCE(idev->cnf.ndisc_evict_nocarrier) && 1883 READ_ONCE(net->ipv6.devconf_all->ndisc_evict_nocarrier); 1884 in6_dev_put(idev); 1885 } 1886 1887 change_info = ptr; 1888 if (change_info->flags_changed & IFF_NOARP) 1889 neigh_changeaddr(&nd_tbl, dev); 1890 if (evict_nocarrier && !netif_carrier_ok(dev)) 1891 neigh_carrier_down(&nd_tbl, dev); 1892 break; 1893 case NETDEV_DOWN: 1894 neigh_ifdown(&nd_tbl, dev); 1895 fib6_run_gc(0, net, false); 1896 break; 1897 case NETDEV_NOTIFY_PEERS: 1898 ndisc_send_unsol_na(dev); 1899 break; 1900 default: 1901 break; 1902 } 1903 1904 return NOTIFY_DONE; 1905 } 1906 1907 static struct notifier_block ndisc_netdev_notifier = { 1908 .notifier_call = ndisc_netdev_event, 1909 .priority = ADDRCONF_NOTIFY_PRIORITY - 5, 1910 }; 1911 1912 #ifdef CONFIG_SYSCTL 1913 static void ndisc_warn_deprecated_sysctl(const struct ctl_table *ctl, 1914 const char *func, const char *dev_name) 1915 { 1916 static char warncomm[TASK_COMM_LEN]; 1917 static int warned; 1918 if (strcmp(warncomm, current->comm) && warned < 5) { 1919 strscpy(warncomm, current->comm); 1920 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n", 1921 warncomm, func, 1922 dev_name, ctl->procname, 1923 dev_name, ctl->procname); 1924 warned++; 1925 } 1926 } 1927 1928 int ndisc_ifinfo_sysctl_change(const struct ctl_table *ctl, int write, void *buffer, 1929 size_t *lenp, loff_t *ppos) 1930 { 1931 struct net_device *dev = ctl->extra1; 1932 struct inet6_dev *idev; 1933 int ret; 1934 1935 if ((strcmp(ctl->procname, "retrans_time") == 0) || 1936 (strcmp(ctl->procname, "base_reachable_time") == 0)) 1937 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default"); 1938 1939 if (strcmp(ctl->procname, "retrans_time") == 0) 1940 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos); 1941 1942 else if (strcmp(ctl->procname, "base_reachable_time") == 0) 1943 ret = neigh_proc_dointvec_jiffies(ctl, write, 1944 buffer, lenp, ppos); 1945 1946 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) || 1947 (strcmp(ctl->procname, "base_reachable_time_ms") == 0)) 1948 ret = neigh_proc_dointvec_ms_jiffies(ctl, write, 1949 buffer, lenp, ppos); 1950 else 1951 ret = -1; 1952 1953 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) { 1954 if (ctl->data == NEIGH_VAR_PTR(idev->nd_parms, BASE_REACHABLE_TIME)) 1955 neigh_set_reach_time(idev->nd_parms); 1956 1957 WRITE_ONCE(idev->tstamp, jiffies); 1958 inet6_ifinfo_notify(RTM_NEWLINK, idev); 1959 in6_dev_put(idev); 1960 } 1961 return ret; 1962 } 1963 1964 1965 #endif 1966 1967 static int __net_init ndisc_net_init(struct net *net) 1968 { 1969 struct ipv6_pinfo *np; 1970 struct sock *sk; 1971 int err; 1972 1973 err = inet_ctl_sock_create(&sk, PF_INET6, 1974 SOCK_RAW, IPPROTO_ICMPV6, net); 1975 if (err < 0) { 1976 net_err_ratelimited("NDISC: Failed to initialize the control socket (err %d)\n", 1977 err); 1978 return err; 1979 } 1980 1981 net->ipv6.ndisc_sk = sk; 1982 1983 np = inet6_sk(sk); 1984 np->hop_limit = 255; 1985 /* Do not loopback ndisc messages */ 1986 inet6_clear_bit(MC6_LOOP, sk); 1987 1988 return 0; 1989 } 1990 1991 static void __net_exit ndisc_net_exit(struct net *net) 1992 { 1993 inet_ctl_sock_destroy(net->ipv6.ndisc_sk); 1994 } 1995 1996 static struct pernet_operations ndisc_net_ops = { 1997 .init = ndisc_net_init, 1998 .exit = ndisc_net_exit, 1999 }; 2000 2001 int __init ndisc_init(void) 2002 { 2003 int err; 2004 2005 err = register_pernet_subsys(&ndisc_net_ops); 2006 if (err) 2007 return err; 2008 /* 2009 * Initialize the neighbour table 2010 */ 2011 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl); 2012 2013 #ifdef CONFIG_SYSCTL 2014 err = neigh_sysctl_register(NULL, &nd_tbl.parms, 2015 ndisc_ifinfo_sysctl_change); 2016 if (err) 2017 goto out_unregister_pernet; 2018 out: 2019 #endif 2020 return err; 2021 2022 #ifdef CONFIG_SYSCTL 2023 out_unregister_pernet: 2024 unregister_pernet_subsys(&ndisc_net_ops); 2025 goto out; 2026 #endif 2027 } 2028 2029 int __init ndisc_late_init(void) 2030 { 2031 return register_netdevice_notifier(&ndisc_netdev_notifier); 2032 } 2033 2034 void ndisc_late_cleanup(void) 2035 { 2036 unregister_netdevice_notifier(&ndisc_netdev_notifier); 2037 } 2038 2039 void ndisc_cleanup(void) 2040 { 2041 #ifdef CONFIG_SYSCTL 2042 neigh_sysctl_unregister(&nd_tbl.parms); 2043 #endif 2044 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl); 2045 unregister_pernet_subsys(&ndisc_net_ops); 2046 } 2047