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