1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Neighbour Discovery for IPv6 4 * Linux INET6 implementation 5 * 6 * Authors: 7 * Pedro Roque <roque@di.fc.ul.pt> 8 * Mike Shaver <shaver@ingenia.com> 9 */ 10 11 /* 12 * Changes: 13 * 14 * Alexey I. Froloff : RFC6106 (DNSSL) support 15 * Pierre Ynard : export userland ND options 16 * through netlink (RDNSS support) 17 * Lars Fenneberg : fixed MTU setting on receipt 18 * of an RA. 19 * Janos Farkas : kmalloc failure checks 20 * Alexey Kuznetsov : state machine reworked 21 * and moved to net/core. 22 * Pekka Savola : RFC2461 validation 23 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly 24 */ 25 26 #define pr_fmt(fmt) "ICMPv6: " fmt 27 28 #include <linux/module.h> 29 #include <linux/errno.h> 30 #include <linux/types.h> 31 #include <linux/socket.h> 32 #include <linux/sockios.h> 33 #include <linux/sched.h> 34 #include <linux/net.h> 35 #include <linux/in6.h> 36 #include <linux/route.h> 37 #include <linux/init.h> 38 #include <linux/rcupdate.h> 39 #include <linux/slab.h> 40 #ifdef CONFIG_SYSCTL 41 #include <linux/sysctl.h> 42 #endif 43 44 #include <linux/if_addr.h> 45 #include <linux/if_ether.h> 46 #include <linux/if_arp.h> 47 #include <linux/ipv6.h> 48 #include <linux/icmpv6.h> 49 #include <linux/jhash.h> 50 51 #include <net/sock.h> 52 #include <net/snmp.h> 53 54 #include <net/ipv6.h> 55 #include <net/protocol.h> 56 #include <net/ndisc.h> 57 #include <net/ip6_route.h> 58 #include <net/addrconf.h> 59 #include <net/icmp.h> 60 61 #include <net/netlink.h> 62 #include <linux/rtnetlink.h> 63 64 #include <net/flow.h> 65 #include <net/ip6_checksum.h> 66 #include <net/inet_common.h> 67 #include <linux/proc_fs.h> 68 69 #include <linux/netfilter.h> 70 #include <linux/netfilter_ipv6.h> 71 72 static u32 ndisc_hash(const void *pkey, 73 const struct net_device *dev, 74 __u32 *hash_rnd); 75 static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey); 76 static bool ndisc_allow_add(const struct net_device *dev, 77 struct netlink_ext_ack *extack); 78 static int ndisc_constructor(struct neighbour *neigh); 79 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb); 80 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb); 81 static int pndisc_constructor(struct pneigh_entry *n); 82 static void pndisc_destructor(struct pneigh_entry *n); 83 static void pndisc_redo(struct sk_buff *skb); 84 static int ndisc_is_multicast(const void *pkey); 85 86 static const struct neigh_ops ndisc_generic_ops = { 87 .family = AF_INET6, 88 .solicit = ndisc_solicit, 89 .error_report = ndisc_error_report, 90 .output = neigh_resolve_output, 91 .connected_output = neigh_connected_output, 92 }; 93 94 static const struct neigh_ops ndisc_hh_ops = { 95 .family = AF_INET6, 96 .solicit = ndisc_solicit, 97 .error_report = ndisc_error_report, 98 .output = neigh_resolve_output, 99 .connected_output = neigh_resolve_output, 100 }; 101 102 103 static const struct neigh_ops ndisc_direct_ops = { 104 .family = AF_INET6, 105 .output = neigh_direct_output, 106 .connected_output = neigh_direct_output, 107 }; 108 109 struct neigh_table nd_tbl = { 110 .family = AF_INET6, 111 .key_len = sizeof(struct in6_addr), 112 .protocol = cpu_to_be16(ETH_P_IPV6), 113 .hash = ndisc_hash, 114 .key_eq = ndisc_key_eq, 115 .constructor = ndisc_constructor, 116 .pconstructor = pndisc_constructor, 117 .pdestructor = pndisc_destructor, 118 .proxy_redo = pndisc_redo, 119 .is_multicast = ndisc_is_multicast, 120 .allow_add = ndisc_allow_add, 121 .id = "ndisc_cache", 122 .parms = { 123 .tbl = &nd_tbl, 124 .reachable_time = ND_REACHABLE_TIME, 125 .data = { 126 [NEIGH_VAR_MCAST_PROBES] = 3, 127 [NEIGH_VAR_UCAST_PROBES] = 3, 128 [NEIGH_VAR_RETRANS_TIME] = ND_RETRANS_TIMER, 129 [NEIGH_VAR_BASE_REACHABLE_TIME] = ND_REACHABLE_TIME, 130 [NEIGH_VAR_DELAY_PROBE_TIME] = 5 * HZ, 131 [NEIGH_VAR_INTERVAL_PROBE_TIME_MS] = 5 * HZ, 132 [NEIGH_VAR_GC_STALETIME] = 60 * HZ, 133 [NEIGH_VAR_QUEUE_LEN_BYTES] = SK_WMEM_MAX, 134 [NEIGH_VAR_PROXY_QLEN] = 64, 135 [NEIGH_VAR_ANYCAST_DELAY] = 1 * HZ, 136 [NEIGH_VAR_PROXY_DELAY] = (8 * HZ) / 10, 137 }, 138 }, 139 .gc_interval = 30 * HZ, 140 .gc_thresh1 = 128, 141 .gc_thresh2 = 512, 142 .gc_thresh3 = 1024, 143 }; 144 EXPORT_SYMBOL_GPL(nd_tbl); 145 146 void __ndisc_fill_addr_option(struct sk_buff *skb, int type, const void *data, 147 int data_len, int pad) 148 { 149 int space = __ndisc_opt_addr_space(data_len, pad); 150 u8 *opt = skb_put(skb, space); 151 152 opt[0] = type; 153 opt[1] = space>>3; 154 155 memset(opt + 2, 0, pad); 156 opt += pad; 157 space -= pad; 158 159 memcpy(opt+2, data, data_len); 160 data_len += 2; 161 opt += data_len; 162 space -= data_len; 163 if (space > 0) 164 memset(opt, 0, space); 165 } 166 EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option); 167 168 static inline void ndisc_fill_addr_option(struct sk_buff *skb, int type, 169 const void *data, u8 icmp6_type) 170 { 171 __ndisc_fill_addr_option(skb, type, data, skb->dev->addr_len, 172 ndisc_addr_option_pad(skb->dev->type)); 173 ndisc_ops_fill_addr_option(skb->dev, skb, icmp6_type); 174 } 175 176 static inline void ndisc_fill_redirect_addr_option(struct sk_buff *skb, 177 void *ha, 178 const u8 *ops_data) 179 { 180 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, ha, NDISC_REDIRECT); 181 ndisc_ops_fill_redirect_addr_option(skb->dev, skb, ops_data); 182 } 183 184 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur, 185 struct nd_opt_hdr *end) 186 { 187 int type; 188 if (!cur || !end || cur >= end) 189 return NULL; 190 type = cur->nd_opt_type; 191 do { 192 cur = ((void *)cur) + (cur->nd_opt_len << 3); 193 } while (cur < end && cur->nd_opt_type != type); 194 return cur <= end && cur->nd_opt_type == type ? cur : NULL; 195 } 196 197 static inline int ndisc_is_useropt(const struct net_device *dev, 198 struct nd_opt_hdr *opt) 199 { 200 return opt->nd_opt_type == ND_OPT_RDNSS || 201 opt->nd_opt_type == ND_OPT_DNSSL || 202 opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL || 203 opt->nd_opt_type == ND_OPT_PREF64 || 204 ndisc_ops_is_useropt(dev, opt->nd_opt_type); 205 } 206 207 static struct nd_opt_hdr *ndisc_next_useropt(const struct net_device *dev, 208 struct nd_opt_hdr *cur, 209 struct nd_opt_hdr *end) 210 { 211 if (!cur || !end || cur >= end) 212 return NULL; 213 do { 214 cur = ((void *)cur) + (cur->nd_opt_len << 3); 215 } while (cur < end && !ndisc_is_useropt(dev, cur)); 216 return cur <= end && ndisc_is_useropt(dev, cur) ? cur : NULL; 217 } 218 219 struct ndisc_options *ndisc_parse_options(const struct net_device *dev, 220 u8 *opt, int opt_len, 221 struct ndisc_options *ndopts) 222 { 223 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt; 224 225 if (!nd_opt || opt_len < 0 || !ndopts) 226 return NULL; 227 memset(ndopts, 0, sizeof(*ndopts)); 228 while (opt_len) { 229 int l; 230 if (opt_len < sizeof(struct nd_opt_hdr)) 231 return NULL; 232 l = nd_opt->nd_opt_len << 3; 233 if (opt_len < l || l == 0) 234 return NULL; 235 if (ndisc_ops_parse_options(dev, nd_opt, ndopts)) 236 goto next_opt; 237 switch (nd_opt->nd_opt_type) { 238 case ND_OPT_SOURCE_LL_ADDR: 239 case ND_OPT_TARGET_LL_ADDR: 240 case ND_OPT_MTU: 241 case ND_OPT_NONCE: 242 case ND_OPT_REDIRECT_HDR: 243 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { 244 ND_PRINTK(2, warn, 245 "%s: duplicated ND6 option found: type=%d\n", 246 __func__, nd_opt->nd_opt_type); 247 } else { 248 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; 249 } 250 break; 251 case ND_OPT_PREFIX_INFO: 252 ndopts->nd_opts_pi_end = nd_opt; 253 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type]) 254 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; 255 break; 256 #ifdef CONFIG_IPV6_ROUTE_INFO 257 case ND_OPT_ROUTE_INFO: 258 ndopts->nd_opts_ri_end = nd_opt; 259 if (!ndopts->nd_opts_ri) 260 ndopts->nd_opts_ri = nd_opt; 261 break; 262 #endif 263 default: 264 if (ndisc_is_useropt(dev, nd_opt)) { 265 ndopts->nd_useropts_end = nd_opt; 266 if (!ndopts->nd_useropts) 267 ndopts->nd_useropts = nd_opt; 268 } else { 269 /* 270 * Unknown options must be silently ignored, 271 * to accommodate future extension to the 272 * protocol. 273 */ 274 ND_PRINTK(2, notice, 275 "%s: ignored unsupported option; type=%d, len=%d\n", 276 __func__, 277 nd_opt->nd_opt_type, 278 nd_opt->nd_opt_len); 279 } 280 } 281 next_opt: 282 opt_len -= l; 283 nd_opt = ((void *)nd_opt) + l; 284 } 285 return ndopts; 286 } 287 288 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir) 289 { 290 switch (dev->type) { 291 case ARPHRD_ETHER: 292 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */ 293 case ARPHRD_FDDI: 294 ipv6_eth_mc_map(addr, buf); 295 return 0; 296 case ARPHRD_ARCNET: 297 ipv6_arcnet_mc_map(addr, buf); 298 return 0; 299 case ARPHRD_INFINIBAND: 300 ipv6_ib_mc_map(addr, dev->broadcast, buf); 301 return 0; 302 case ARPHRD_IPGRE: 303 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf); 304 default: 305 if (dir) { 306 memcpy(buf, dev->broadcast, dev->addr_len); 307 return 0; 308 } 309 } 310 return -EINVAL; 311 } 312 EXPORT_SYMBOL(ndisc_mc_map); 313 314 static u32 ndisc_hash(const void *pkey, 315 const struct net_device *dev, 316 __u32 *hash_rnd) 317 { 318 return ndisc_hashfn(pkey, dev, hash_rnd); 319 } 320 321 static bool ndisc_key_eq(const struct neighbour *n, const void *pkey) 322 { 323 return neigh_key_eq128(n, pkey); 324 } 325 326 static int ndisc_constructor(struct neighbour *neigh) 327 { 328 struct in6_addr *addr = (struct in6_addr *)&neigh->primary_key; 329 struct net_device *dev = neigh->dev; 330 struct inet6_dev *in6_dev; 331 struct neigh_parms *parms; 332 bool is_multicast = ipv6_addr_is_multicast(addr); 333 334 in6_dev = in6_dev_get(dev); 335 if (!in6_dev) { 336 return -EINVAL; 337 } 338 339 parms = in6_dev->nd_parms; 340 __neigh_parms_put(neigh->parms); 341 neigh->parms = neigh_parms_clone(parms); 342 343 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST; 344 if (!dev->header_ops) { 345 neigh->nud_state = NUD_NOARP; 346 neigh->ops = &ndisc_direct_ops; 347 neigh->output = neigh_direct_output; 348 } else { 349 if (is_multicast) { 350 neigh->nud_state = NUD_NOARP; 351 ndisc_mc_map(addr, neigh->ha, dev, 1); 352 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { 353 neigh->nud_state = NUD_NOARP; 354 memcpy(neigh->ha, dev->dev_addr, dev->addr_len); 355 if (dev->flags&IFF_LOOPBACK) 356 neigh->type = RTN_LOCAL; 357 } else if (dev->flags&IFF_POINTOPOINT) { 358 neigh->nud_state = NUD_NOARP; 359 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 360 } 361 if (dev->header_ops->cache) 362 neigh->ops = &ndisc_hh_ops; 363 else 364 neigh->ops = &ndisc_generic_ops; 365 if (neigh->nud_state&NUD_VALID) 366 neigh->output = neigh->ops->connected_output; 367 else 368 neigh->output = neigh->ops->output; 369 } 370 in6_dev_put(in6_dev); 371 return 0; 372 } 373 374 static int pndisc_constructor(struct pneigh_entry *n) 375 { 376 struct in6_addr *addr = (struct in6_addr *)&n->key; 377 struct in6_addr maddr; 378 struct net_device *dev = n->dev; 379 380 if (!dev || !__in6_dev_get(dev)) 381 return -EINVAL; 382 addrconf_addr_solict_mult(addr, &maddr); 383 ipv6_dev_mc_inc(dev, &maddr); 384 return 0; 385 } 386 387 static void pndisc_destructor(struct pneigh_entry *n) 388 { 389 struct in6_addr *addr = (struct in6_addr *)&n->key; 390 struct in6_addr maddr; 391 struct net_device *dev = n->dev; 392 393 if (!dev || !__in6_dev_get(dev)) 394 return; 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 sock *sk = dev_net(dev)->ipv6.ndisc_sk; 419 struct sk_buff *skb; 420 421 skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC); 422 if (!skb) { 423 ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n", 424 __func__); 425 return NULL; 426 } 427 428 skb->protocol = htons(ETH_P_IPV6); 429 skb->dev = dev; 430 431 skb_reserve(skb, hlen + sizeof(struct ipv6hdr)); 432 skb_reset_transport_header(skb); 433 434 /* Manually assign socket ownership as we avoid calling 435 * sock_alloc_send_pskb() to bypass wmem buffer limits 436 */ 437 skb_set_owner_w(skb, sk); 438 439 return skb; 440 } 441 442 static void ip6_nd_hdr(struct sk_buff *skb, 443 const struct in6_addr *saddr, 444 const struct in6_addr *daddr, 445 int hop_limit, int len) 446 { 447 struct ipv6hdr *hdr; 448 struct inet6_dev *idev; 449 unsigned tclass; 450 451 rcu_read_lock(); 452 idev = __in6_dev_get(skb->dev); 453 tclass = idev ? idev->cnf.ndisc_tclass : 0; 454 rcu_read_unlock(); 455 456 skb_push(skb, sizeof(*hdr)); 457 skb_reset_network_header(skb); 458 hdr = ipv6_hdr(skb); 459 460 ip6_flow_hdr(hdr, tclass, 0); 461 462 hdr->payload_len = htons(len); 463 hdr->nexthdr = IPPROTO_ICMPV6; 464 hdr->hop_limit = hop_limit; 465 466 hdr->saddr = *saddr; 467 hdr->daddr = *daddr; 468 } 469 470 void ndisc_send_skb(struct sk_buff *skb, const struct in6_addr *daddr, 471 const struct in6_addr *saddr) 472 { 473 struct dst_entry *dst = skb_dst(skb); 474 struct net *net = dev_net(skb->dev); 475 struct sock *sk = net->ipv6.ndisc_sk; 476 struct inet6_dev *idev; 477 int err; 478 struct icmp6hdr *icmp6h = icmp6_hdr(skb); 479 u8 type; 480 481 type = icmp6h->icmp6_type; 482 483 if (!dst) { 484 struct flowi6 fl6; 485 int oif = skb->dev->ifindex; 486 487 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, oif); 488 dst = icmp6_dst_alloc(skb->dev, &fl6); 489 if (IS_ERR(dst)) { 490 kfree_skb(skb); 491 return; 492 } 493 494 skb_dst_set(skb, dst); 495 } 496 497 icmp6h->icmp6_cksum = csum_ipv6_magic(saddr, daddr, skb->len, 498 IPPROTO_ICMPV6, 499 csum_partial(icmp6h, 500 skb->len, 0)); 501 502 ip6_nd_hdr(skb, saddr, daddr, inet6_sk(sk)->hop_limit, skb->len); 503 504 rcu_read_lock(); 505 idev = __in6_dev_get(dst->dev); 506 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len); 507 508 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, 509 net, sk, skb, NULL, dst->dev, 510 dst_output); 511 if (!err) { 512 ICMP6MSGOUT_INC_STATS(net, idev, type); 513 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 514 } 515 516 rcu_read_unlock(); 517 } 518 EXPORT_SYMBOL(ndisc_send_skb); 519 520 void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr, 521 const struct in6_addr *solicited_addr, 522 bool router, bool solicited, bool override, bool inc_opt) 523 { 524 struct sk_buff *skb; 525 struct in6_addr tmpaddr; 526 struct inet6_ifaddr *ifp; 527 const struct in6_addr *src_addr; 528 struct nd_msg *msg; 529 int optlen = 0; 530 531 /* for anycast or proxy, solicited_addr != src_addr */ 532 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1); 533 if (ifp) { 534 src_addr = solicited_addr; 535 if (ifp->flags & IFA_F_OPTIMISTIC) 536 override = false; 537 inc_opt |= ifp->idev->cnf.force_tllao; 538 in6_ifa_put(ifp); 539 } else { 540 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr, 541 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs, 542 &tmpaddr)) 543 return; 544 src_addr = &tmpaddr; 545 } 546 547 if (!dev->addr_len) 548 inc_opt = false; 549 if (inc_opt) 550 optlen += ndisc_opt_addr_space(dev, 551 NDISC_NEIGHBOUR_ADVERTISEMENT); 552 553 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 554 if (!skb) 555 return; 556 557 msg = skb_put(skb, sizeof(*msg)); 558 *msg = (struct nd_msg) { 559 .icmph = { 560 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT, 561 .icmp6_router = router, 562 .icmp6_solicited = solicited, 563 .icmp6_override = override, 564 }, 565 .target = *solicited_addr, 566 }; 567 568 if (inc_opt) 569 ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR, 570 dev->dev_addr, 571 NDISC_NEIGHBOUR_ADVERTISEMENT); 572 573 ndisc_send_skb(skb, daddr, src_addr); 574 } 575 576 static void ndisc_send_unsol_na(struct net_device *dev) 577 { 578 struct inet6_dev *idev; 579 struct inet6_ifaddr *ifa; 580 581 idev = in6_dev_get(dev); 582 if (!idev) 583 return; 584 585 read_lock_bh(&idev->lock); 586 list_for_each_entry(ifa, &idev->addr_list, if_list) { 587 /* skip tentative addresses until dad completes */ 588 if (ifa->flags & IFA_F_TENTATIVE && 589 !(ifa->flags & IFA_F_OPTIMISTIC)) 590 continue; 591 592 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &ifa->addr, 593 /*router=*/ !!idev->cnf.forwarding, 594 /*solicited=*/ false, /*override=*/ true, 595 /*inc_opt=*/ true); 596 } 597 read_unlock_bh(&idev->lock); 598 599 in6_dev_put(idev); 600 } 601 602 struct sk_buff *ndisc_ns_create(struct net_device *dev, const struct in6_addr *solicit, 603 const struct in6_addr *saddr, u64 nonce) 604 { 605 int inc_opt = dev->addr_len; 606 struct sk_buff *skb; 607 struct nd_msg *msg; 608 int optlen = 0; 609 610 if (!saddr) 611 return NULL; 612 613 if (ipv6_addr_any(saddr)) 614 inc_opt = false; 615 if (inc_opt) 616 optlen += ndisc_opt_addr_space(dev, 617 NDISC_NEIGHBOUR_SOLICITATION); 618 if (nonce != 0) 619 optlen += 8; 620 621 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 622 if (!skb) 623 return NULL; 624 625 msg = skb_put(skb, sizeof(*msg)); 626 *msg = (struct nd_msg) { 627 .icmph = { 628 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION, 629 }, 630 .target = *solicit, 631 }; 632 633 if (inc_opt) 634 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR, 635 dev->dev_addr, 636 NDISC_NEIGHBOUR_SOLICITATION); 637 if (nonce != 0) { 638 u8 *opt = skb_put(skb, 8); 639 640 opt[0] = ND_OPT_NONCE; 641 opt[1] = 8 >> 3; 642 memcpy(opt + 2, &nonce, 6); 643 } 644 645 return skb; 646 } 647 EXPORT_SYMBOL(ndisc_ns_create); 648 649 void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit, 650 const struct in6_addr *daddr, const struct in6_addr *saddr, 651 u64 nonce) 652 { 653 struct in6_addr addr_buf; 654 struct sk_buff *skb; 655 656 if (!saddr) { 657 if (ipv6_get_lladdr(dev, &addr_buf, 658 (IFA_F_TENTATIVE | IFA_F_OPTIMISTIC))) 659 return; 660 saddr = &addr_buf; 661 } 662 663 skb = ndisc_ns_create(dev, solicit, saddr, nonce); 664 665 if (skb) 666 ndisc_send_skb(skb, daddr, saddr); 667 } 668 669 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr, 670 const struct in6_addr *daddr) 671 { 672 struct sk_buff *skb; 673 struct rs_msg *msg; 674 int send_sllao = dev->addr_len; 675 int optlen = 0; 676 677 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 678 /* 679 * According to section 2.2 of RFC 4429, we must not 680 * send router solicitations with a sllao from 681 * optimistic addresses, but we may send the solicitation 682 * if we don't include the sllao. So here we check 683 * if our address is optimistic, and if so, we 684 * suppress the inclusion of the sllao. 685 */ 686 if (send_sllao) { 687 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr, 688 dev, 1); 689 if (ifp) { 690 if (ifp->flags & IFA_F_OPTIMISTIC) { 691 send_sllao = 0; 692 } 693 in6_ifa_put(ifp); 694 } else { 695 send_sllao = 0; 696 } 697 } 698 #endif 699 if (send_sllao) 700 optlen += ndisc_opt_addr_space(dev, NDISC_ROUTER_SOLICITATION); 701 702 skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 703 if (!skb) 704 return; 705 706 msg = skb_put(skb, sizeof(*msg)); 707 *msg = (struct rs_msg) { 708 .icmph = { 709 .icmp6_type = NDISC_ROUTER_SOLICITATION, 710 }, 711 }; 712 713 if (send_sllao) 714 ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR, 715 dev->dev_addr, 716 NDISC_ROUTER_SOLICITATION); 717 718 ndisc_send_skb(skb, daddr, saddr); 719 } 720 721 722 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb) 723 { 724 /* 725 * "The sender MUST return an ICMP 726 * destination unreachable" 727 */ 728 dst_link_failure(skb); 729 kfree_skb(skb); 730 } 731 732 /* Called with locked neigh: either read or both */ 733 734 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb) 735 { 736 struct in6_addr *saddr = NULL; 737 struct in6_addr mcaddr; 738 struct net_device *dev = neigh->dev; 739 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key; 740 int probes = atomic_read(&neigh->probes); 741 742 if (skb && ipv6_chk_addr_and_flags(dev_net(dev), &ipv6_hdr(skb)->saddr, 743 dev, false, 1, 744 IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) 745 saddr = &ipv6_hdr(skb)->saddr; 746 probes -= NEIGH_VAR(neigh->parms, UCAST_PROBES); 747 if (probes < 0) { 748 if (!(READ_ONCE(neigh->nud_state) & NUD_VALID)) { 749 ND_PRINTK(1, dbg, 750 "%s: trying to ucast probe in NUD_INVALID: %pI6\n", 751 __func__, target); 752 } 753 ndisc_send_ns(dev, target, target, saddr, 0); 754 } else if ((probes -= NEIGH_VAR(neigh->parms, APP_PROBES)) < 0) { 755 neigh_app_ns(neigh); 756 } else { 757 addrconf_addr_solict_mult(target, &mcaddr); 758 ndisc_send_ns(dev, target, &mcaddr, saddr, 0); 759 } 760 } 761 762 static int pndisc_is_router(const void *pkey, 763 struct net_device *dev) 764 { 765 struct pneigh_entry *n; 766 int ret = -1; 767 768 read_lock_bh(&nd_tbl.lock); 769 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev); 770 if (n) 771 ret = !!(n->flags & NTF_ROUTER); 772 read_unlock_bh(&nd_tbl.lock); 773 774 return ret; 775 } 776 777 void ndisc_update(const struct net_device *dev, struct neighbour *neigh, 778 const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type, 779 struct ndisc_options *ndopts) 780 { 781 neigh_update(neigh, lladdr, new, flags, 0); 782 /* report ndisc ops about neighbour update */ 783 ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts); 784 } 785 786 static enum skb_drop_reason ndisc_recv_ns(struct sk_buff *skb) 787 { 788 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 789 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 790 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 791 u8 *lladdr = NULL; 792 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 793 offsetof(struct nd_msg, opt)); 794 struct ndisc_options ndopts; 795 struct net_device *dev = skb->dev; 796 struct inet6_ifaddr *ifp; 797 struct inet6_dev *idev = NULL; 798 struct neighbour *neigh; 799 int dad = ipv6_addr_any(saddr); 800 int is_router = -1; 801 SKB_DR(reason); 802 u64 nonce = 0; 803 bool inc; 804 805 if (skb->len < sizeof(struct nd_msg)) 806 return SKB_DROP_REASON_PKT_TOO_SMALL; 807 808 if (ipv6_addr_is_multicast(&msg->target)) { 809 ND_PRINTK(2, warn, "NS: multicast target address\n"); 810 return reason; 811 } 812 813 /* 814 * RFC2461 7.1.1: 815 * DAD has to be destined for solicited node multicast address. 816 */ 817 if (dad && !ipv6_addr_is_solict_mult(daddr)) { 818 ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n"); 819 return reason; 820 } 821 822 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) 823 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 824 825 if (ndopts.nd_opts_src_lladdr) { 826 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev); 827 if (!lladdr) { 828 ND_PRINTK(2, warn, 829 "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 ND_PRINTK(2, warn, 840 "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 ND_PRINTK(2, notice, 858 "%s: IPv6 DAD loopback for address %pI6c nonce %pM ignored\n", 859 ifp->idev->dev->name, 860 &ifp->addr, np); 861 goto out; 862 } 863 /* 864 * We are colliding with another node 865 * who is doing DAD 866 * so fail our DAD process 867 */ 868 addrconf_dad_failure(skb, ifp); 869 return reason; 870 } else { 871 /* 872 * This is not a dad solicitation. 873 * If we are an optimistic node, 874 * we should respond. 875 * Otherwise, we should ignore it. 876 */ 877 if (!(ifp->flags & IFA_F_OPTIMISTIC)) 878 goto out; 879 } 880 } 881 882 idev = ifp->idev; 883 } else { 884 struct net *net = dev_net(dev); 885 886 /* perhaps an address on the master device */ 887 if (netif_is_l3_slave(dev)) { 888 struct net_device *mdev; 889 890 mdev = netdev_master_upper_dev_get_rcu(dev); 891 if (mdev) { 892 ifp = ipv6_get_ifaddr(net, &msg->target, mdev, 1); 893 if (ifp) 894 goto have_ifp; 895 } 896 } 897 898 idev = in6_dev_get(dev); 899 if (!idev) { 900 /* XXX: count this drop? */ 901 return reason; 902 } 903 904 if (ipv6_chk_acast_addr(net, dev, &msg->target) || 905 (idev->cnf.forwarding && 906 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) && 907 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) { 908 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) && 909 skb->pkt_type != PACKET_HOST && 910 inc && 911 NEIGH_VAR(idev->nd_parms, PROXY_DELAY) != 0) { 912 /* 913 * for anycast or proxy, 914 * sender should delay its response 915 * by a random time between 0 and 916 * MAX_ANYCAST_DELAY_TIME seconds. 917 * (RFC2461) -- yoshfuji 918 */ 919 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC); 920 if (n) 921 pneigh_enqueue(&nd_tbl, idev->nd_parms, n); 922 goto out; 923 } 924 } else { 925 SKB_DR_SET(reason, IPV6_NDISC_NS_OTHERHOST); 926 goto out; 927 } 928 } 929 930 if (is_router < 0) 931 is_router = idev->cnf.forwarding; 932 933 if (dad) { 934 ndisc_send_na(dev, &in6addr_linklocal_allnodes, &msg->target, 935 !!is_router, false, (ifp != NULL), true); 936 goto out; 937 } 938 939 if (inc) 940 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast); 941 else 942 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast); 943 944 /* 945 * update / create cache entry 946 * for the source address 947 */ 948 neigh = __neigh_lookup(&nd_tbl, saddr, dev, 949 !inc || lladdr || !dev->addr_len); 950 if (neigh) 951 ndisc_update(dev, neigh, lladdr, NUD_STALE, 952 NEIGH_UPDATE_F_WEAK_OVERRIDE| 953 NEIGH_UPDATE_F_OVERRIDE, 954 NDISC_NEIGHBOUR_SOLICITATION, &ndopts); 955 if (neigh || !dev->header_ops) { 956 ndisc_send_na(dev, saddr, &msg->target, !!is_router, 957 true, (ifp != NULL && inc), inc); 958 if (neigh) 959 neigh_release(neigh); 960 reason = SKB_CONSUMED; 961 } 962 963 out: 964 if (ifp) 965 in6_ifa_put(ifp); 966 else 967 in6_dev_put(idev); 968 return reason; 969 } 970 971 static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr) 972 { 973 struct inet6_dev *idev = __in6_dev_get(dev); 974 975 switch (idev->cnf.accept_untracked_na) { 976 case 0: /* Don't accept untracked na (absent in neighbor cache) */ 977 return 0; 978 case 1: /* Create new entries from na if currently untracked */ 979 return 1; 980 case 2: /* Create new entries from untracked na only if saddr is in the 981 * same subnet as an address configured on the interface that 982 * received the na 983 */ 984 return !!ipv6_chk_prefix(saddr, dev); 985 default: 986 return 0; 987 } 988 } 989 990 static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb) 991 { 992 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 993 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 994 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 995 u8 *lladdr = NULL; 996 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 997 offsetof(struct nd_msg, opt)); 998 struct ndisc_options ndopts; 999 struct net_device *dev = skb->dev; 1000 struct inet6_dev *idev = __in6_dev_get(dev); 1001 struct inet6_ifaddr *ifp; 1002 struct neighbour *neigh; 1003 SKB_DR(reason); 1004 u8 new_state; 1005 1006 if (skb->len < sizeof(struct nd_msg)) 1007 return SKB_DROP_REASON_PKT_TOO_SMALL; 1008 1009 if (ipv6_addr_is_multicast(&msg->target)) { 1010 ND_PRINTK(2, warn, "NA: target address is multicast\n"); 1011 return reason; 1012 } 1013 1014 if (ipv6_addr_is_multicast(daddr) && 1015 msg->icmph.icmp6_solicited) { 1016 ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n"); 1017 return reason; 1018 } 1019 1020 /* For some 802.11 wireless deployments (and possibly other networks), 1021 * there will be a NA proxy and unsolicitd packets are attacks 1022 * and thus should not be accepted. 1023 * drop_unsolicited_na takes precedence over accept_untracked_na 1024 */ 1025 if (!msg->icmph.icmp6_solicited && idev && 1026 idev->cnf.drop_unsolicited_na) 1027 return reason; 1028 1029 if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) 1030 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1031 1032 if (ndopts.nd_opts_tgt_lladdr) { 1033 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev); 1034 if (!lladdr) { 1035 ND_PRINTK(2, warn, 1036 "NA: invalid link-layer address length\n"); 1037 return reason; 1038 } 1039 } 1040 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); 1041 if (ifp) { 1042 if (skb->pkt_type != PACKET_LOOPBACK 1043 && (ifp->flags & IFA_F_TENTATIVE)) { 1044 addrconf_dad_failure(skb, ifp); 1045 return reason; 1046 } 1047 /* What should we make now? The advertisement 1048 is invalid, but ndisc specs say nothing 1049 about it. It could be misconfiguration, or 1050 an smart proxy agent tries to help us :-) 1051 1052 We should not print the error if NA has been 1053 received from loopback - it is just our own 1054 unsolicited advertisement. 1055 */ 1056 if (skb->pkt_type != PACKET_LOOPBACK) 1057 ND_PRINTK(1, warn, 1058 "NA: %pM advertised our address %pI6c on %s!\n", 1059 eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name); 1060 in6_ifa_put(ifp); 1061 return reason; 1062 } 1063 1064 neigh = neigh_lookup(&nd_tbl, &msg->target, dev); 1065 1066 /* RFC 9131 updates original Neighbour Discovery RFC 4861. 1067 * NAs with Target LL Address option without a corresponding 1068 * entry in the neighbour cache can now create a STALE neighbour 1069 * cache entry on routers. 1070 * 1071 * entry accept fwding solicited behaviour 1072 * ------- ------ ------ --------- ---------------------- 1073 * present X X 0 Set state to STALE 1074 * present X X 1 Set state to REACHABLE 1075 * absent 0 X X Do nothing 1076 * absent 1 0 X Do nothing 1077 * absent 1 1 X Add a new STALE entry 1078 * 1079 * Note that we don't do a (daddr == all-routers-mcast) check. 1080 */ 1081 new_state = msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE; 1082 if (!neigh && lladdr && idev && idev->cnf.forwarding) { 1083 if (accept_untracked_na(dev, saddr)) { 1084 neigh = neigh_create(&nd_tbl, &msg->target, dev); 1085 new_state = NUD_STALE; 1086 } 1087 } 1088 1089 if (neigh && !IS_ERR(neigh)) { 1090 u8 old_flags = neigh->flags; 1091 struct net *net = dev_net(dev); 1092 1093 if (READ_ONCE(neigh->nud_state) & NUD_FAILED) 1094 goto out; 1095 1096 /* 1097 * Don't update the neighbor cache entry on a proxy NA from 1098 * ourselves because either the proxied node is off link or it 1099 * has already sent a NA to us. 1100 */ 1101 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) && 1102 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp && 1103 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) { 1104 /* XXX: idev->cnf.proxy_ndp */ 1105 goto out; 1106 } 1107 1108 ndisc_update(dev, neigh, lladdr, 1109 new_state, 1110 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1111 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)| 1112 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1113 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0), 1114 NDISC_NEIGHBOUR_ADVERTISEMENT, &ndopts); 1115 1116 if ((old_flags & ~neigh->flags) & NTF_ROUTER) { 1117 /* 1118 * Change: router to host 1119 */ 1120 rt6_clean_tohost(dev_net(dev), saddr); 1121 } 1122 reason = SKB_CONSUMED; 1123 out: 1124 neigh_release(neigh); 1125 } 1126 return reason; 1127 } 1128 1129 static enum skb_drop_reason ndisc_recv_rs(struct sk_buff *skb) 1130 { 1131 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb); 1132 unsigned long ndoptlen = skb->len - sizeof(*rs_msg); 1133 struct neighbour *neigh; 1134 struct inet6_dev *idev; 1135 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 1136 struct ndisc_options ndopts; 1137 u8 *lladdr = NULL; 1138 SKB_DR(reason); 1139 1140 if (skb->len < sizeof(*rs_msg)) 1141 return SKB_DROP_REASON_PKT_TOO_SMALL; 1142 1143 idev = __in6_dev_get(skb->dev); 1144 if (!idev) { 1145 ND_PRINTK(1, err, "RS: can't find in6 device\n"); 1146 return reason; 1147 } 1148 1149 /* Don't accept RS if we're not in router mode */ 1150 if (!idev->cnf.forwarding) 1151 goto out; 1152 1153 /* 1154 * Don't update NCE if src = ::; 1155 * this implies that the source node has no ip address assigned yet. 1156 */ 1157 if (ipv6_addr_any(saddr)) 1158 goto out; 1159 1160 /* Parse ND options */ 1161 if (!ndisc_parse_options(skb->dev, rs_msg->opt, ndoptlen, &ndopts)) 1162 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1163 1164 if (ndopts.nd_opts_src_lladdr) { 1165 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1166 skb->dev); 1167 if (!lladdr) 1168 goto out; 1169 } 1170 1171 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1); 1172 if (neigh) { 1173 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE, 1174 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1175 NEIGH_UPDATE_F_OVERRIDE| 1176 NEIGH_UPDATE_F_OVERRIDE_ISROUTER, 1177 NDISC_ROUTER_SOLICITATION, &ndopts); 1178 neigh_release(neigh); 1179 reason = SKB_CONSUMED; 1180 } 1181 out: 1182 return reason; 1183 } 1184 1185 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt) 1186 { 1187 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra); 1188 struct sk_buff *skb; 1189 struct nlmsghdr *nlh; 1190 struct nduseroptmsg *ndmsg; 1191 struct net *net = dev_net(ra->dev); 1192 int err; 1193 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg) 1194 + (opt->nd_opt_len << 3)); 1195 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr)); 1196 1197 skb = nlmsg_new(msg_size, GFP_ATOMIC); 1198 if (!skb) { 1199 err = -ENOBUFS; 1200 goto errout; 1201 } 1202 1203 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0); 1204 if (!nlh) { 1205 goto nla_put_failure; 1206 } 1207 1208 ndmsg = nlmsg_data(nlh); 1209 ndmsg->nduseropt_family = AF_INET6; 1210 ndmsg->nduseropt_ifindex = ra->dev->ifindex; 1211 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type; 1212 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code; 1213 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3; 1214 1215 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3); 1216 1217 if (nla_put_in6_addr(skb, NDUSEROPT_SRCADDR, &ipv6_hdr(ra)->saddr)) 1218 goto nla_put_failure; 1219 nlmsg_end(skb, nlh); 1220 1221 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC); 1222 return; 1223 1224 nla_put_failure: 1225 nlmsg_free(skb); 1226 err = -EMSGSIZE; 1227 errout: 1228 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err); 1229 } 1230 1231 static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb) 1232 { 1233 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb); 1234 bool send_ifinfo_notify = false; 1235 struct neighbour *neigh = NULL; 1236 struct ndisc_options ndopts; 1237 struct fib6_info *rt = NULL; 1238 struct inet6_dev *in6_dev; 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 ND_PRINTK(2, info, 1253 "RA: %s, dev: %s\n", 1254 __func__, skb->dev->name); 1255 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1256 ND_PRINTK(2, warn, "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 ND_PRINTK(2, warn, "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 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n", 1272 skb->dev->name); 1273 return reason; 1274 } 1275 1276 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) 1277 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1278 1279 if (!ipv6_accept_ra(in6_dev)) { 1280 ND_PRINTK(2, info, 1281 "RA: %s, did not accept ra for dev: %s\n", 1282 __func__, skb->dev->name); 1283 goto skip_linkparms; 1284 } 1285 1286 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1287 /* skip link-specific parameters from interior routers */ 1288 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1289 ND_PRINTK(2, info, 1290 "RA: %s, nodetype is NODEFAULT, dev: %s\n", 1291 __func__, skb->dev->name); 1292 goto skip_linkparms; 1293 } 1294 #endif 1295 1296 if (in6_dev->if_flags & IF_RS_SENT) { 1297 /* 1298 * flag that an RA was received after an RS was sent 1299 * out on this interface. 1300 */ 1301 in6_dev->if_flags |= IF_RA_RCVD; 1302 } 1303 1304 /* 1305 * Remember the managed/otherconf flags from most recently 1306 * received RA message (RFC 2462) -- yoshfuji 1307 */ 1308 old_if_flags = in6_dev->if_flags; 1309 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED | 1310 IF_RA_OTHERCONF)) | 1311 (ra_msg->icmph.icmp6_addrconf_managed ? 1312 IF_RA_MANAGED : 0) | 1313 (ra_msg->icmph.icmp6_addrconf_other ? 1314 IF_RA_OTHERCONF : 0); 1315 1316 if (old_if_flags != in6_dev->if_flags) 1317 send_ifinfo_notify = true; 1318 1319 if (!in6_dev->cnf.accept_ra_defrtr) { 1320 ND_PRINTK(2, info, 1321 "RA: %s, defrtr is false for dev: %s\n", 1322 __func__, skb->dev->name); 1323 goto skip_defrtr; 1324 } 1325 1326 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); 1327 if (lifetime != 0 && lifetime < in6_dev->cnf.accept_ra_min_lft) { 1328 ND_PRINTK(2, info, 1329 "RA: router lifetime (%ds) is too short: %s\n", 1330 lifetime, skb->dev->name); 1331 goto skip_defrtr; 1332 } 1333 1334 /* Do not accept RA with source-addr found on local machine unless 1335 * accept_ra_from_local is set to true. 1336 */ 1337 net = dev_net(in6_dev->dev); 1338 if (!in6_dev->cnf.accept_ra_from_local && 1339 ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) { 1340 ND_PRINTK(2, info, 1341 "RA from local address detected on dev: %s: default router ignored\n", 1342 skb->dev->name); 1343 goto skip_defrtr; 1344 } 1345 1346 #ifdef CONFIG_IPV6_ROUTER_PREF 1347 pref = ra_msg->icmph.icmp6_router_pref; 1348 /* 10b is handled as if it were 00b (medium) */ 1349 if (pref == ICMPV6_ROUTER_PREF_INVALID || 1350 !in6_dev->cnf.accept_ra_rtr_pref) 1351 pref = ICMPV6_ROUTER_PREF_MEDIUM; 1352 #endif 1353 /* routes added from RAs do not use nexthop objects */ 1354 rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev); 1355 if (rt) { 1356 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6, 1357 rt->fib6_nh->fib_nh_dev, NULL, 1358 &ipv6_hdr(skb)->saddr); 1359 if (!neigh) { 1360 ND_PRINTK(0, err, 1361 "RA: %s got default router without neighbour\n", 1362 __func__); 1363 fib6_info_release(rt); 1364 return reason; 1365 } 1366 } 1367 /* Set default route metric as specified by user */ 1368 defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric; 1369 /* delete the route if lifetime is 0 or if metric needs change */ 1370 if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) { 1371 ip6_del_rt(net, rt, false); 1372 rt = NULL; 1373 } 1374 1375 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n", 1376 rt, lifetime, defrtr_usr_metric, skb->dev->name); 1377 if (!rt && lifetime) { 1378 ND_PRINTK(3, info, "RA: adding default router\n"); 1379 1380 if (neigh) 1381 neigh_release(neigh); 1382 1383 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr, 1384 skb->dev, pref, defrtr_usr_metric); 1385 if (!rt) { 1386 ND_PRINTK(0, err, 1387 "RA: %s failed to add default route\n", 1388 __func__); 1389 return reason; 1390 } 1391 1392 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6, 1393 rt->fib6_nh->fib_nh_dev, NULL, 1394 &ipv6_hdr(skb)->saddr); 1395 if (!neigh) { 1396 ND_PRINTK(0, err, 1397 "RA: %s got default router without neighbour\n", 1398 __func__); 1399 fib6_info_release(rt); 1400 return reason; 1401 } 1402 neigh->flags |= NTF_ROUTER; 1403 } else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) { 1404 struct nl_info nlinfo = { 1405 .nl_net = net, 1406 }; 1407 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 1408 inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_REPLACE); 1409 } 1410 1411 if (rt) 1412 fib6_set_expires(rt, jiffies + (HZ * lifetime)); 1413 if (in6_dev->cnf.accept_ra_min_hop_limit < 256 && 1414 ra_msg->icmph.icmp6_hop_limit) { 1415 if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) { 1416 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit; 1417 fib6_metric_set(rt, RTAX_HOPLIMIT, 1418 ra_msg->icmph.icmp6_hop_limit); 1419 } else { 1420 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n"); 1421 } 1422 } 1423 1424 skip_defrtr: 1425 1426 /* 1427 * Update Reachable Time and Retrans Timer 1428 */ 1429 1430 if (in6_dev->nd_parms) { 1431 unsigned long rtime = ntohl(ra_msg->retrans_timer); 1432 1433 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) { 1434 rtime = (rtime*HZ)/1000; 1435 if (rtime < HZ/100) 1436 rtime = HZ/100; 1437 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime); 1438 in6_dev->tstamp = jiffies; 1439 send_ifinfo_notify = true; 1440 } 1441 1442 rtime = ntohl(ra_msg->reachable_time); 1443 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) { 1444 rtime = (rtime*HZ)/1000; 1445 1446 if (rtime < HZ/10) 1447 rtime = HZ/10; 1448 1449 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) { 1450 NEIGH_VAR_SET(in6_dev->nd_parms, 1451 BASE_REACHABLE_TIME, rtime); 1452 NEIGH_VAR_SET(in6_dev->nd_parms, 1453 GC_STALETIME, 3 * rtime); 1454 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime); 1455 in6_dev->tstamp = jiffies; 1456 send_ifinfo_notify = true; 1457 } 1458 } 1459 } 1460 1461 skip_linkparms: 1462 1463 /* 1464 * Process options. 1465 */ 1466 1467 if (!neigh) 1468 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr, 1469 skb->dev, 1); 1470 if (neigh) { 1471 u8 *lladdr = NULL; 1472 if (ndopts.nd_opts_src_lladdr) { 1473 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1474 skb->dev); 1475 if (!lladdr) { 1476 ND_PRINTK(2, warn, 1477 "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 ND_PRINTK(2, info, 1492 "RA: %s, accept_ra is false for dev: %s\n", 1493 __func__, skb->dev->name); 1494 goto out; 1495 } 1496 1497 #ifdef CONFIG_IPV6_ROUTE_INFO 1498 if (!in6_dev->cnf.accept_ra_from_local && 1499 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, 1500 in6_dev->dev, 0)) { 1501 ND_PRINTK(2, info, 1502 "RA from local address detected on dev: %s: router info ignored.\n", 1503 skb->dev->name); 1504 goto skip_routeinfo; 1505 } 1506 1507 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) { 1508 struct nd_opt_hdr *p; 1509 for (p = ndopts.nd_opts_ri; 1510 p; 1511 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) { 1512 struct route_info *ri = (struct route_info *)p; 1513 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1514 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT && 1515 ri->prefix_len == 0) 1516 continue; 1517 #endif 1518 if (ri->prefix_len == 0 && 1519 !in6_dev->cnf.accept_ra_defrtr) 1520 continue; 1521 if (ri->lifetime != 0 && 1522 ntohl(ri->lifetime) < in6_dev->cnf.accept_ra_min_lft) 1523 continue; 1524 if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen) 1525 continue; 1526 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen) 1527 continue; 1528 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3, 1529 &ipv6_hdr(skb)->saddr); 1530 } 1531 } 1532 1533 skip_routeinfo: 1534 #endif 1535 1536 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1537 /* skip link-specific ndopts from interior routers */ 1538 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1539 ND_PRINTK(2, info, 1540 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n", 1541 __func__, skb->dev->name); 1542 goto out; 1543 } 1544 #endif 1545 1546 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) { 1547 struct nd_opt_hdr *p; 1548 for (p = ndopts.nd_opts_pi; 1549 p; 1550 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) { 1551 addrconf_prefix_rcv(skb->dev, (u8 *)p, 1552 (p->nd_opt_len) << 3, 1553 ndopts.nd_opts_src_lladdr != NULL); 1554 } 1555 } 1556 1557 if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) { 1558 __be32 n; 1559 u32 mtu; 1560 1561 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); 1562 mtu = ntohl(n); 1563 1564 if (in6_dev->ra_mtu != mtu) { 1565 in6_dev->ra_mtu = mtu; 1566 send_ifinfo_notify = true; 1567 } 1568 1569 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { 1570 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu); 1571 } else if (in6_dev->cnf.mtu6 != mtu) { 1572 in6_dev->cnf.mtu6 = mtu; 1573 fib6_metric_set(rt, RTAX_MTU, mtu); 1574 rt6_mtu_change(skb->dev, mtu); 1575 } 1576 } 1577 1578 if (ndopts.nd_useropts) { 1579 struct nd_opt_hdr *p; 1580 for (p = ndopts.nd_useropts; 1581 p; 1582 p = ndisc_next_useropt(skb->dev, p, 1583 ndopts.nd_useropts_end)) { 1584 ndisc_ra_useropt(skb, p); 1585 } 1586 } 1587 1588 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { 1589 ND_PRINTK(2, warn, "RA: invalid RA options\n"); 1590 } 1591 out: 1592 /* Send a notify if RA changed managed/otherconf flags or 1593 * timer settings or ra_mtu value 1594 */ 1595 if (send_ifinfo_notify) 1596 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1597 1598 fib6_info_release(rt); 1599 if (neigh) 1600 neigh_release(neigh); 1601 return reason; 1602 } 1603 1604 static enum skb_drop_reason ndisc_redirect_rcv(struct sk_buff *skb) 1605 { 1606 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb); 1607 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 1608 offsetof(struct rd_msg, opt)); 1609 struct ndisc_options ndopts; 1610 SKB_DR(reason); 1611 u8 *hdr; 1612 1613 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1614 switch (skb->ndisc_nodetype) { 1615 case NDISC_NODETYPE_HOST: 1616 case NDISC_NODETYPE_NODEFAULT: 1617 ND_PRINTK(2, warn, 1618 "Redirect: from host or unauthorized router\n"); 1619 return reason; 1620 } 1621 #endif 1622 1623 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1624 ND_PRINTK(2, warn, 1625 "Redirect: source address is not link-local\n"); 1626 return reason; 1627 } 1628 1629 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts)) 1630 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1631 1632 if (!ndopts.nd_opts_rh) { 1633 ip6_redirect_no_header(skb, dev_net(skb->dev), 1634 skb->dev->ifindex); 1635 return reason; 1636 } 1637 1638 hdr = (u8 *)ndopts.nd_opts_rh; 1639 hdr += 8; 1640 if (!pskb_pull(skb, hdr - skb_transport_header(skb))) 1641 return SKB_DROP_REASON_PKT_TOO_SMALL; 1642 1643 return icmpv6_notify(skb, NDISC_REDIRECT, 0, 0); 1644 } 1645 1646 static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb, 1647 struct sk_buff *orig_skb, 1648 int rd_len) 1649 { 1650 u8 *opt = skb_put(skb, rd_len); 1651 1652 memset(opt, 0, 8); 1653 *(opt++) = ND_OPT_REDIRECT_HDR; 1654 *(opt++) = (rd_len >> 3); 1655 opt += 6; 1656 1657 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt, 1658 rd_len - 8); 1659 } 1660 1661 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target) 1662 { 1663 struct net_device *dev = skb->dev; 1664 struct net *net = dev_net(dev); 1665 struct sock *sk = net->ipv6.ndisc_sk; 1666 int optlen = 0; 1667 struct inet_peer *peer; 1668 struct sk_buff *buff; 1669 struct rd_msg *msg; 1670 struct in6_addr saddr_buf; 1671 struct rt6_info *rt; 1672 struct dst_entry *dst; 1673 struct flowi6 fl6; 1674 int rd_len; 1675 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL, 1676 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL; 1677 bool ret; 1678 1679 if (netif_is_l3_master(skb->dev)) { 1680 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 1681 if (!dev) 1682 return; 1683 } 1684 1685 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) { 1686 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n", 1687 dev->name); 1688 return; 1689 } 1690 1691 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) && 1692 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1693 ND_PRINTK(2, warn, 1694 "Redirect: target address is not link-local unicast\n"); 1695 return; 1696 } 1697 1698 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT, 1699 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex); 1700 1701 dst = ip6_route_output(net, NULL, &fl6); 1702 if (dst->error) { 1703 dst_release(dst); 1704 return; 1705 } 1706 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); 1707 if (IS_ERR(dst)) 1708 return; 1709 1710 rt = (struct rt6_info *) dst; 1711 1712 if (rt->rt6i_flags & RTF_GATEWAY) { 1713 ND_PRINTK(2, warn, 1714 "Redirect: destination is not a neighbour\n"); 1715 goto release; 1716 } 1717 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1); 1718 ret = inet_peer_xrlim_allow(peer, 1*HZ); 1719 if (peer) 1720 inet_putpeer(peer); 1721 if (!ret) 1722 goto release; 1723 1724 if (dev->addr_len) { 1725 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target); 1726 if (!neigh) { 1727 ND_PRINTK(2, warn, 1728 "Redirect: no neigh for target address\n"); 1729 goto release; 1730 } 1731 1732 read_lock_bh(&neigh->lock); 1733 if (neigh->nud_state & NUD_VALID) { 1734 memcpy(ha_buf, neigh->ha, dev->addr_len); 1735 read_unlock_bh(&neigh->lock); 1736 ha = ha_buf; 1737 optlen += ndisc_redirect_opt_addr_space(dev, neigh, 1738 ops_data_buf, 1739 &ops_data); 1740 } else 1741 read_unlock_bh(&neigh->lock); 1742 1743 neigh_release(neigh); 1744 } 1745 1746 rd_len = min_t(unsigned int, 1747 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen, 1748 skb->len + 8); 1749 rd_len &= ~0x7; 1750 optlen += rd_len; 1751 1752 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 1753 if (!buff) 1754 goto release; 1755 1756 msg = skb_put(buff, sizeof(*msg)); 1757 *msg = (struct rd_msg) { 1758 .icmph = { 1759 .icmp6_type = NDISC_REDIRECT, 1760 }, 1761 .target = *target, 1762 .dest = ipv6_hdr(skb)->daddr, 1763 }; 1764 1765 /* 1766 * include target_address option 1767 */ 1768 1769 if (ha) 1770 ndisc_fill_redirect_addr_option(buff, ha, ops_data); 1771 1772 /* 1773 * build redirect option and copy skb over to the new packet. 1774 */ 1775 1776 if (rd_len) 1777 ndisc_fill_redirect_hdr_option(buff, skb, rd_len); 1778 1779 skb_dst_set(buff, dst); 1780 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf); 1781 return; 1782 1783 release: 1784 dst_release(dst); 1785 } 1786 1787 static void pndisc_redo(struct sk_buff *skb) 1788 { 1789 enum skb_drop_reason reason = ndisc_recv_ns(skb); 1790 1791 kfree_skb_reason(skb, reason); 1792 } 1793 1794 static int ndisc_is_multicast(const void *pkey) 1795 { 1796 return ipv6_addr_is_multicast((struct in6_addr *)pkey); 1797 } 1798 1799 static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb) 1800 { 1801 struct inet6_dev *idev = __in6_dev_get(skb->dev); 1802 1803 if (!idev) 1804 return true; 1805 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED && 1806 idev->cnf.suppress_frag_ndisc) { 1807 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n"); 1808 return true; 1809 } 1810 return false; 1811 } 1812 1813 enum skb_drop_reason ndisc_rcv(struct sk_buff *skb) 1814 { 1815 struct nd_msg *msg; 1816 SKB_DR(reason); 1817 1818 if (ndisc_suppress_frag_ndisc(skb)) 1819 return SKB_DROP_REASON_IPV6_NDISC_FRAG; 1820 1821 if (skb_linearize(skb)) 1822 return SKB_DROP_REASON_NOMEM; 1823 1824 msg = (struct nd_msg *)skb_transport_header(skb); 1825 1826 __skb_push(skb, skb->data - skb_transport_header(skb)); 1827 1828 if (ipv6_hdr(skb)->hop_limit != 255) { 1829 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n", 1830 ipv6_hdr(skb)->hop_limit); 1831 return SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT; 1832 } 1833 1834 if (msg->icmph.icmp6_code != 0) { 1835 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n", 1836 msg->icmph.icmp6_code); 1837 return SKB_DROP_REASON_IPV6_NDISC_BAD_CODE; 1838 } 1839 1840 switch (msg->icmph.icmp6_type) { 1841 case NDISC_NEIGHBOUR_SOLICITATION: 1842 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 1843 reason = ndisc_recv_ns(skb); 1844 break; 1845 1846 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1847 reason = ndisc_recv_na(skb); 1848 break; 1849 1850 case NDISC_ROUTER_SOLICITATION: 1851 reason = ndisc_recv_rs(skb); 1852 break; 1853 1854 case NDISC_ROUTER_ADVERTISEMENT: 1855 reason = ndisc_router_discovery(skb); 1856 break; 1857 1858 case NDISC_REDIRECT: 1859 reason = ndisc_redirect_rcv(skb); 1860 break; 1861 } 1862 1863 return reason; 1864 } 1865 1866 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1867 { 1868 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1869 struct netdev_notifier_change_info *change_info; 1870 struct net *net = dev_net(dev); 1871 struct inet6_dev *idev; 1872 bool evict_nocarrier; 1873 1874 switch (event) { 1875 case NETDEV_CHANGEADDR: 1876 neigh_changeaddr(&nd_tbl, dev); 1877 fib6_run_gc(0, net, false); 1878 fallthrough; 1879 case NETDEV_UP: 1880 idev = in6_dev_get(dev); 1881 if (!idev) 1882 break; 1883 if (idev->cnf.ndisc_notify || 1884 net->ipv6.devconf_all->ndisc_notify) 1885 ndisc_send_unsol_na(dev); 1886 in6_dev_put(idev); 1887 break; 1888 case NETDEV_CHANGE: 1889 idev = in6_dev_get(dev); 1890 if (!idev) 1891 evict_nocarrier = true; 1892 else { 1893 evict_nocarrier = idev->cnf.ndisc_evict_nocarrier && 1894 net->ipv6.devconf_all->ndisc_evict_nocarrier; 1895 in6_dev_put(idev); 1896 } 1897 1898 change_info = ptr; 1899 if (change_info->flags_changed & IFF_NOARP) 1900 neigh_changeaddr(&nd_tbl, dev); 1901 if (evict_nocarrier && !netif_carrier_ok(dev)) 1902 neigh_carrier_down(&nd_tbl, dev); 1903 break; 1904 case NETDEV_DOWN: 1905 neigh_ifdown(&nd_tbl, dev); 1906 fib6_run_gc(0, net, false); 1907 break; 1908 case NETDEV_NOTIFY_PEERS: 1909 ndisc_send_unsol_na(dev); 1910 break; 1911 default: 1912 break; 1913 } 1914 1915 return NOTIFY_DONE; 1916 } 1917 1918 static struct notifier_block ndisc_netdev_notifier = { 1919 .notifier_call = ndisc_netdev_event, 1920 .priority = ADDRCONF_NOTIFY_PRIORITY - 5, 1921 }; 1922 1923 #ifdef CONFIG_SYSCTL 1924 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl, 1925 const char *func, const char *dev_name) 1926 { 1927 static char warncomm[TASK_COMM_LEN]; 1928 static int warned; 1929 if (strcmp(warncomm, current->comm) && warned < 5) { 1930 strcpy(warncomm, current->comm); 1931 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n", 1932 warncomm, func, 1933 dev_name, ctl->procname, 1934 dev_name, ctl->procname); 1935 warned++; 1936 } 1937 } 1938 1939 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer, 1940 size_t *lenp, loff_t *ppos) 1941 { 1942 struct net_device *dev = ctl->extra1; 1943 struct inet6_dev *idev; 1944 int ret; 1945 1946 if ((strcmp(ctl->procname, "retrans_time") == 0) || 1947 (strcmp(ctl->procname, "base_reachable_time") == 0)) 1948 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default"); 1949 1950 if (strcmp(ctl->procname, "retrans_time") == 0) 1951 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos); 1952 1953 else if (strcmp(ctl->procname, "base_reachable_time") == 0) 1954 ret = neigh_proc_dointvec_jiffies(ctl, write, 1955 buffer, lenp, ppos); 1956 1957 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) || 1958 (strcmp(ctl->procname, "base_reachable_time_ms") == 0)) 1959 ret = neigh_proc_dointvec_ms_jiffies(ctl, write, 1960 buffer, lenp, ppos); 1961 else 1962 ret = -1; 1963 1964 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) { 1965 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)) 1966 idev->nd_parms->reachable_time = 1967 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)); 1968 idev->tstamp = jiffies; 1969 inet6_ifinfo_notify(RTM_NEWLINK, idev); 1970 in6_dev_put(idev); 1971 } 1972 return ret; 1973 } 1974 1975 1976 #endif 1977 1978 static int __net_init ndisc_net_init(struct net *net) 1979 { 1980 struct ipv6_pinfo *np; 1981 struct sock *sk; 1982 int err; 1983 1984 err = inet_ctl_sock_create(&sk, PF_INET6, 1985 SOCK_RAW, IPPROTO_ICMPV6, net); 1986 if (err < 0) { 1987 ND_PRINTK(0, err, 1988 "NDISC: Failed to initialize the control socket (err %d)\n", 1989 err); 1990 return err; 1991 } 1992 1993 net->ipv6.ndisc_sk = sk; 1994 1995 np = inet6_sk(sk); 1996 np->hop_limit = 255; 1997 /* Do not loopback ndisc messages */ 1998 np->mc_loop = 0; 1999 2000 return 0; 2001 } 2002 2003 static void __net_exit ndisc_net_exit(struct net *net) 2004 { 2005 inet_ctl_sock_destroy(net->ipv6.ndisc_sk); 2006 } 2007 2008 static struct pernet_operations ndisc_net_ops = { 2009 .init = ndisc_net_init, 2010 .exit = ndisc_net_exit, 2011 }; 2012 2013 int __init ndisc_init(void) 2014 { 2015 int err; 2016 2017 err = register_pernet_subsys(&ndisc_net_ops); 2018 if (err) 2019 return err; 2020 /* 2021 * Initialize the neighbour table 2022 */ 2023 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl); 2024 2025 #ifdef CONFIG_SYSCTL 2026 err = neigh_sysctl_register(NULL, &nd_tbl.parms, 2027 ndisc_ifinfo_sysctl_change); 2028 if (err) 2029 goto out_unregister_pernet; 2030 out: 2031 #endif 2032 return err; 2033 2034 #ifdef CONFIG_SYSCTL 2035 out_unregister_pernet: 2036 unregister_pernet_subsys(&ndisc_net_ops); 2037 goto out; 2038 #endif 2039 } 2040 2041 int __init ndisc_late_init(void) 2042 { 2043 return register_netdevice_notifier(&ndisc_netdev_notifier); 2044 } 2045 2046 void ndisc_late_cleanup(void) 2047 { 2048 unregister_netdevice_notifier(&ndisc_netdev_notifier); 2049 } 2050 2051 void ndisc_cleanup(void) 2052 { 2053 #ifdef CONFIG_SYSCTL 2054 neigh_sysctl_unregister(&nd_tbl.parms); 2055 #endif 2056 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl); 2057 unregister_pernet_subsys(&ndisc_net_ops); 2058 } 2059