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 /* 1270 * set the RA_RECV flag in the interface 1271 */ 1272 1273 in6_dev = __in6_dev_get(skb->dev); 1274 if (!in6_dev) { 1275 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n", 1276 skb->dev->name); 1277 return reason; 1278 } 1279 1280 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) 1281 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1282 1283 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); 1284 1285 if (!ipv6_accept_ra(in6_dev)) { 1286 ND_PRINTK(2, info, 1287 "RA: %s, did not accept ra for dev: %s\n", 1288 __func__, skb->dev->name); 1289 goto skip_linkparms; 1290 } 1291 1292 if (lifetime != 0 && lifetime < in6_dev->cnf.accept_ra_min_rtr_lft) { 1293 ND_PRINTK(2, info, 1294 "RA: router lifetime (%ds) is too short: %s\n", 1295 lifetime, skb->dev->name); 1296 goto skip_linkparms; 1297 } 1298 1299 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1300 /* skip link-specific parameters from interior routers */ 1301 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1302 ND_PRINTK(2, info, 1303 "RA: %s, nodetype is NODEFAULT, dev: %s\n", 1304 __func__, skb->dev->name); 1305 goto skip_linkparms; 1306 } 1307 #endif 1308 1309 if (in6_dev->if_flags & IF_RS_SENT) { 1310 /* 1311 * flag that an RA was received after an RS was sent 1312 * out on this interface. 1313 */ 1314 in6_dev->if_flags |= IF_RA_RCVD; 1315 } 1316 1317 /* 1318 * Remember the managed/otherconf flags from most recently 1319 * received RA message (RFC 2462) -- yoshfuji 1320 */ 1321 old_if_flags = in6_dev->if_flags; 1322 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED | 1323 IF_RA_OTHERCONF)) | 1324 (ra_msg->icmph.icmp6_addrconf_managed ? 1325 IF_RA_MANAGED : 0) | 1326 (ra_msg->icmph.icmp6_addrconf_other ? 1327 IF_RA_OTHERCONF : 0); 1328 1329 if (old_if_flags != in6_dev->if_flags) 1330 send_ifinfo_notify = true; 1331 1332 if (!in6_dev->cnf.accept_ra_defrtr) { 1333 ND_PRINTK(2, info, 1334 "RA: %s, defrtr is false for dev: %s\n", 1335 __func__, skb->dev->name); 1336 goto skip_defrtr; 1337 } 1338 1339 /* Do not accept RA with source-addr found on local machine unless 1340 * accept_ra_from_local is set to true. 1341 */ 1342 net = dev_net(in6_dev->dev); 1343 if (!in6_dev->cnf.accept_ra_from_local && 1344 ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) { 1345 ND_PRINTK(2, info, 1346 "RA from local address detected on dev: %s: default router ignored\n", 1347 skb->dev->name); 1348 goto skip_defrtr; 1349 } 1350 1351 #ifdef CONFIG_IPV6_ROUTER_PREF 1352 pref = ra_msg->icmph.icmp6_router_pref; 1353 /* 10b is handled as if it were 00b (medium) */ 1354 if (pref == ICMPV6_ROUTER_PREF_INVALID || 1355 !in6_dev->cnf.accept_ra_rtr_pref) 1356 pref = ICMPV6_ROUTER_PREF_MEDIUM; 1357 #endif 1358 /* routes added from RAs do not use nexthop objects */ 1359 rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev); 1360 if (rt) { 1361 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6, 1362 rt->fib6_nh->fib_nh_dev, NULL, 1363 &ipv6_hdr(skb)->saddr); 1364 if (!neigh) { 1365 ND_PRINTK(0, err, 1366 "RA: %s got default router without neighbour\n", 1367 __func__); 1368 fib6_info_release(rt); 1369 return reason; 1370 } 1371 } 1372 /* Set default route metric as specified by user */ 1373 defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric; 1374 /* delete the route if lifetime is 0 or if metric needs change */ 1375 if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) { 1376 ip6_del_rt(net, rt, false); 1377 rt = NULL; 1378 } 1379 1380 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n", 1381 rt, lifetime, defrtr_usr_metric, skb->dev->name); 1382 if (!rt && lifetime) { 1383 ND_PRINTK(3, info, "RA: adding default router\n"); 1384 1385 if (neigh) 1386 neigh_release(neigh); 1387 1388 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr, 1389 skb->dev, pref, defrtr_usr_metric); 1390 if (!rt) { 1391 ND_PRINTK(0, err, 1392 "RA: %s failed to add default route\n", 1393 __func__); 1394 return reason; 1395 } 1396 1397 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6, 1398 rt->fib6_nh->fib_nh_dev, NULL, 1399 &ipv6_hdr(skb)->saddr); 1400 if (!neigh) { 1401 ND_PRINTK(0, err, 1402 "RA: %s got default router without neighbour\n", 1403 __func__); 1404 fib6_info_release(rt); 1405 return reason; 1406 } 1407 neigh->flags |= NTF_ROUTER; 1408 } else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) { 1409 struct nl_info nlinfo = { 1410 .nl_net = net, 1411 }; 1412 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 1413 inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_REPLACE); 1414 } 1415 1416 if (rt) 1417 fib6_set_expires(rt, jiffies + (HZ * lifetime)); 1418 if (in6_dev->cnf.accept_ra_min_hop_limit < 256 && 1419 ra_msg->icmph.icmp6_hop_limit) { 1420 if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) { 1421 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit; 1422 fib6_metric_set(rt, RTAX_HOPLIMIT, 1423 ra_msg->icmph.icmp6_hop_limit); 1424 } else { 1425 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n"); 1426 } 1427 } 1428 1429 skip_defrtr: 1430 1431 /* 1432 * Update Reachable Time and Retrans Timer 1433 */ 1434 1435 if (in6_dev->nd_parms) { 1436 unsigned long rtime = ntohl(ra_msg->retrans_timer); 1437 1438 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) { 1439 rtime = (rtime*HZ)/1000; 1440 if (rtime < HZ/100) 1441 rtime = HZ/100; 1442 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime); 1443 in6_dev->tstamp = jiffies; 1444 send_ifinfo_notify = true; 1445 } 1446 1447 rtime = ntohl(ra_msg->reachable_time); 1448 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) { 1449 rtime = (rtime*HZ)/1000; 1450 1451 if (rtime < HZ/10) 1452 rtime = HZ/10; 1453 1454 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) { 1455 NEIGH_VAR_SET(in6_dev->nd_parms, 1456 BASE_REACHABLE_TIME, rtime); 1457 NEIGH_VAR_SET(in6_dev->nd_parms, 1458 GC_STALETIME, 3 * rtime); 1459 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime); 1460 in6_dev->tstamp = jiffies; 1461 send_ifinfo_notify = true; 1462 } 1463 } 1464 } 1465 1466 skip_linkparms: 1467 1468 /* 1469 * Process options. 1470 */ 1471 1472 if (!neigh) 1473 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr, 1474 skb->dev, 1); 1475 if (neigh) { 1476 u8 *lladdr = NULL; 1477 if (ndopts.nd_opts_src_lladdr) { 1478 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1479 skb->dev); 1480 if (!lladdr) { 1481 ND_PRINTK(2, warn, 1482 "RA: invalid link-layer address length\n"); 1483 goto out; 1484 } 1485 } 1486 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE, 1487 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1488 NEIGH_UPDATE_F_OVERRIDE| 1489 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1490 NEIGH_UPDATE_F_ISROUTER, 1491 NDISC_ROUTER_ADVERTISEMENT, &ndopts); 1492 reason = SKB_CONSUMED; 1493 } 1494 1495 if (!ipv6_accept_ra(in6_dev)) { 1496 ND_PRINTK(2, info, 1497 "RA: %s, accept_ra is false for dev: %s\n", 1498 __func__, skb->dev->name); 1499 goto out; 1500 } 1501 1502 if (lifetime != 0 && lifetime < in6_dev->cnf.accept_ra_min_rtr_lft) { 1503 ND_PRINTK(2, info, 1504 "RA: router lifetime (%ds) is too short: %s\n", 1505 lifetime, skb->dev->name); 1506 goto out; 1507 } 1508 1509 #ifdef CONFIG_IPV6_ROUTE_INFO 1510 if (!in6_dev->cnf.accept_ra_from_local && 1511 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, 1512 in6_dev->dev, 0)) { 1513 ND_PRINTK(2, info, 1514 "RA from local address detected on dev: %s: router info ignored.\n", 1515 skb->dev->name); 1516 goto skip_routeinfo; 1517 } 1518 1519 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) { 1520 struct nd_opt_hdr *p; 1521 for (p = ndopts.nd_opts_ri; 1522 p; 1523 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) { 1524 struct route_info *ri = (struct route_info *)p; 1525 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1526 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT && 1527 ri->prefix_len == 0) 1528 continue; 1529 #endif 1530 if (ri->prefix_len == 0 && 1531 !in6_dev->cnf.accept_ra_defrtr) 1532 continue; 1533 if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen) 1534 continue; 1535 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen) 1536 continue; 1537 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3, 1538 &ipv6_hdr(skb)->saddr); 1539 } 1540 } 1541 1542 skip_routeinfo: 1543 #endif 1544 1545 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1546 /* skip link-specific ndopts from interior routers */ 1547 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1548 ND_PRINTK(2, info, 1549 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n", 1550 __func__, skb->dev->name); 1551 goto out; 1552 } 1553 #endif 1554 1555 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) { 1556 struct nd_opt_hdr *p; 1557 for (p = ndopts.nd_opts_pi; 1558 p; 1559 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) { 1560 addrconf_prefix_rcv(skb->dev, (u8 *)p, 1561 (p->nd_opt_len) << 3, 1562 ndopts.nd_opts_src_lladdr != NULL); 1563 } 1564 } 1565 1566 if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) { 1567 __be32 n; 1568 u32 mtu; 1569 1570 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); 1571 mtu = ntohl(n); 1572 1573 if (in6_dev->ra_mtu != mtu) { 1574 in6_dev->ra_mtu = mtu; 1575 send_ifinfo_notify = true; 1576 } 1577 1578 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { 1579 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu); 1580 } else if (in6_dev->cnf.mtu6 != mtu) { 1581 in6_dev->cnf.mtu6 = mtu; 1582 fib6_metric_set(rt, RTAX_MTU, mtu); 1583 rt6_mtu_change(skb->dev, mtu); 1584 } 1585 } 1586 1587 if (ndopts.nd_useropts) { 1588 struct nd_opt_hdr *p; 1589 for (p = ndopts.nd_useropts; 1590 p; 1591 p = ndisc_next_useropt(skb->dev, p, 1592 ndopts.nd_useropts_end)) { 1593 ndisc_ra_useropt(skb, p); 1594 } 1595 } 1596 1597 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { 1598 ND_PRINTK(2, warn, "RA: invalid RA options\n"); 1599 } 1600 out: 1601 /* Send a notify if RA changed managed/otherconf flags or 1602 * timer settings or ra_mtu value 1603 */ 1604 if (send_ifinfo_notify) 1605 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1606 1607 fib6_info_release(rt); 1608 if (neigh) 1609 neigh_release(neigh); 1610 return reason; 1611 } 1612 1613 static enum skb_drop_reason ndisc_redirect_rcv(struct sk_buff *skb) 1614 { 1615 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb); 1616 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 1617 offsetof(struct rd_msg, opt)); 1618 struct ndisc_options ndopts; 1619 SKB_DR(reason); 1620 u8 *hdr; 1621 1622 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1623 switch (skb->ndisc_nodetype) { 1624 case NDISC_NODETYPE_HOST: 1625 case NDISC_NODETYPE_NODEFAULT: 1626 ND_PRINTK(2, warn, 1627 "Redirect: from host or unauthorized router\n"); 1628 return reason; 1629 } 1630 #endif 1631 1632 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1633 ND_PRINTK(2, warn, 1634 "Redirect: source address is not link-local\n"); 1635 return reason; 1636 } 1637 1638 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts)) 1639 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1640 1641 if (!ndopts.nd_opts_rh) { 1642 ip6_redirect_no_header(skb, dev_net(skb->dev), 1643 skb->dev->ifindex); 1644 return reason; 1645 } 1646 1647 hdr = (u8 *)ndopts.nd_opts_rh; 1648 hdr += 8; 1649 if (!pskb_pull(skb, hdr - skb_transport_header(skb))) 1650 return SKB_DROP_REASON_PKT_TOO_SMALL; 1651 1652 return icmpv6_notify(skb, NDISC_REDIRECT, 0, 0); 1653 } 1654 1655 static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb, 1656 struct sk_buff *orig_skb, 1657 int rd_len) 1658 { 1659 u8 *opt = skb_put(skb, rd_len); 1660 1661 memset(opt, 0, 8); 1662 *(opt++) = ND_OPT_REDIRECT_HDR; 1663 *(opt++) = (rd_len >> 3); 1664 opt += 6; 1665 1666 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt, 1667 rd_len - 8); 1668 } 1669 1670 void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target) 1671 { 1672 struct net_device *dev = skb->dev; 1673 struct net *net = dev_net(dev); 1674 struct sock *sk = net->ipv6.ndisc_sk; 1675 int optlen = 0; 1676 struct inet_peer *peer; 1677 struct sk_buff *buff; 1678 struct rd_msg *msg; 1679 struct in6_addr saddr_buf; 1680 struct rt6_info *rt; 1681 struct dst_entry *dst; 1682 struct flowi6 fl6; 1683 int rd_len; 1684 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL, 1685 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL; 1686 bool ret; 1687 1688 if (netif_is_l3_master(skb->dev)) { 1689 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 1690 if (!dev) 1691 return; 1692 } 1693 1694 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) { 1695 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n", 1696 dev->name); 1697 return; 1698 } 1699 1700 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) && 1701 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1702 ND_PRINTK(2, warn, 1703 "Redirect: target address is not link-local unicast\n"); 1704 return; 1705 } 1706 1707 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT, 1708 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex); 1709 1710 dst = ip6_route_output(net, NULL, &fl6); 1711 if (dst->error) { 1712 dst_release(dst); 1713 return; 1714 } 1715 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); 1716 if (IS_ERR(dst)) 1717 return; 1718 1719 rt = (struct rt6_info *) dst; 1720 1721 if (rt->rt6i_flags & RTF_GATEWAY) { 1722 ND_PRINTK(2, warn, 1723 "Redirect: destination is not a neighbour\n"); 1724 goto release; 1725 } 1726 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1); 1727 ret = inet_peer_xrlim_allow(peer, 1*HZ); 1728 if (peer) 1729 inet_putpeer(peer); 1730 if (!ret) 1731 goto release; 1732 1733 if (dev->addr_len) { 1734 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target); 1735 if (!neigh) { 1736 ND_PRINTK(2, warn, 1737 "Redirect: no neigh for target address\n"); 1738 goto release; 1739 } 1740 1741 read_lock_bh(&neigh->lock); 1742 if (neigh->nud_state & NUD_VALID) { 1743 memcpy(ha_buf, neigh->ha, dev->addr_len); 1744 read_unlock_bh(&neigh->lock); 1745 ha = ha_buf; 1746 optlen += ndisc_redirect_opt_addr_space(dev, neigh, 1747 ops_data_buf, 1748 &ops_data); 1749 } else 1750 read_unlock_bh(&neigh->lock); 1751 1752 neigh_release(neigh); 1753 } 1754 1755 rd_len = min_t(unsigned int, 1756 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen, 1757 skb->len + 8); 1758 rd_len &= ~0x7; 1759 optlen += rd_len; 1760 1761 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 1762 if (!buff) 1763 goto release; 1764 1765 msg = skb_put(buff, sizeof(*msg)); 1766 *msg = (struct rd_msg) { 1767 .icmph = { 1768 .icmp6_type = NDISC_REDIRECT, 1769 }, 1770 .target = *target, 1771 .dest = ipv6_hdr(skb)->daddr, 1772 }; 1773 1774 /* 1775 * include target_address option 1776 */ 1777 1778 if (ha) 1779 ndisc_fill_redirect_addr_option(buff, ha, ops_data); 1780 1781 /* 1782 * build redirect option and copy skb over to the new packet. 1783 */ 1784 1785 if (rd_len) 1786 ndisc_fill_redirect_hdr_option(buff, skb, rd_len); 1787 1788 skb_dst_set(buff, dst); 1789 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf); 1790 return; 1791 1792 release: 1793 dst_release(dst); 1794 } 1795 1796 static void pndisc_redo(struct sk_buff *skb) 1797 { 1798 enum skb_drop_reason reason = ndisc_recv_ns(skb); 1799 1800 kfree_skb_reason(skb, reason); 1801 } 1802 1803 static int ndisc_is_multicast(const void *pkey) 1804 { 1805 return ipv6_addr_is_multicast((struct in6_addr *)pkey); 1806 } 1807 1808 static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb) 1809 { 1810 struct inet6_dev *idev = __in6_dev_get(skb->dev); 1811 1812 if (!idev) 1813 return true; 1814 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED && 1815 idev->cnf.suppress_frag_ndisc) { 1816 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n"); 1817 return true; 1818 } 1819 return false; 1820 } 1821 1822 enum skb_drop_reason ndisc_rcv(struct sk_buff *skb) 1823 { 1824 struct nd_msg *msg; 1825 SKB_DR(reason); 1826 1827 if (ndisc_suppress_frag_ndisc(skb)) 1828 return SKB_DROP_REASON_IPV6_NDISC_FRAG; 1829 1830 if (skb_linearize(skb)) 1831 return SKB_DROP_REASON_NOMEM; 1832 1833 msg = (struct nd_msg *)skb_transport_header(skb); 1834 1835 __skb_push(skb, skb->data - skb_transport_header(skb)); 1836 1837 if (ipv6_hdr(skb)->hop_limit != 255) { 1838 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n", 1839 ipv6_hdr(skb)->hop_limit); 1840 return SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT; 1841 } 1842 1843 if (msg->icmph.icmp6_code != 0) { 1844 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n", 1845 msg->icmph.icmp6_code); 1846 return SKB_DROP_REASON_IPV6_NDISC_BAD_CODE; 1847 } 1848 1849 switch (msg->icmph.icmp6_type) { 1850 case NDISC_NEIGHBOUR_SOLICITATION: 1851 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 1852 reason = ndisc_recv_ns(skb); 1853 break; 1854 1855 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1856 reason = ndisc_recv_na(skb); 1857 break; 1858 1859 case NDISC_ROUTER_SOLICITATION: 1860 reason = ndisc_recv_rs(skb); 1861 break; 1862 1863 case NDISC_ROUTER_ADVERTISEMENT: 1864 reason = ndisc_router_discovery(skb); 1865 break; 1866 1867 case NDISC_REDIRECT: 1868 reason = ndisc_redirect_rcv(skb); 1869 break; 1870 } 1871 1872 return reason; 1873 } 1874 1875 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1876 { 1877 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1878 struct netdev_notifier_change_info *change_info; 1879 struct net *net = dev_net(dev); 1880 struct inet6_dev *idev; 1881 bool evict_nocarrier; 1882 1883 switch (event) { 1884 case NETDEV_CHANGEADDR: 1885 neigh_changeaddr(&nd_tbl, dev); 1886 fib6_run_gc(0, net, false); 1887 fallthrough; 1888 case NETDEV_UP: 1889 idev = in6_dev_get(dev); 1890 if (!idev) 1891 break; 1892 if (idev->cnf.ndisc_notify || 1893 net->ipv6.devconf_all->ndisc_notify) 1894 ndisc_send_unsol_na(dev); 1895 in6_dev_put(idev); 1896 break; 1897 case NETDEV_CHANGE: 1898 idev = in6_dev_get(dev); 1899 if (!idev) 1900 evict_nocarrier = true; 1901 else { 1902 evict_nocarrier = idev->cnf.ndisc_evict_nocarrier && 1903 net->ipv6.devconf_all->ndisc_evict_nocarrier; 1904 in6_dev_put(idev); 1905 } 1906 1907 change_info = ptr; 1908 if (change_info->flags_changed & IFF_NOARP) 1909 neigh_changeaddr(&nd_tbl, dev); 1910 if (evict_nocarrier && !netif_carrier_ok(dev)) 1911 neigh_carrier_down(&nd_tbl, dev); 1912 break; 1913 case NETDEV_DOWN: 1914 neigh_ifdown(&nd_tbl, dev); 1915 fib6_run_gc(0, net, false); 1916 break; 1917 case NETDEV_NOTIFY_PEERS: 1918 ndisc_send_unsol_na(dev); 1919 break; 1920 default: 1921 break; 1922 } 1923 1924 return NOTIFY_DONE; 1925 } 1926 1927 static struct notifier_block ndisc_netdev_notifier = { 1928 .notifier_call = ndisc_netdev_event, 1929 .priority = ADDRCONF_NOTIFY_PRIORITY - 5, 1930 }; 1931 1932 #ifdef CONFIG_SYSCTL 1933 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl, 1934 const char *func, const char *dev_name) 1935 { 1936 static char warncomm[TASK_COMM_LEN]; 1937 static int warned; 1938 if (strcmp(warncomm, current->comm) && warned < 5) { 1939 strcpy(warncomm, current->comm); 1940 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n", 1941 warncomm, func, 1942 dev_name, ctl->procname, 1943 dev_name, ctl->procname); 1944 warned++; 1945 } 1946 } 1947 1948 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer, 1949 size_t *lenp, loff_t *ppos) 1950 { 1951 struct net_device *dev = ctl->extra1; 1952 struct inet6_dev *idev; 1953 int ret; 1954 1955 if ((strcmp(ctl->procname, "retrans_time") == 0) || 1956 (strcmp(ctl->procname, "base_reachable_time") == 0)) 1957 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default"); 1958 1959 if (strcmp(ctl->procname, "retrans_time") == 0) 1960 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos); 1961 1962 else if (strcmp(ctl->procname, "base_reachable_time") == 0) 1963 ret = neigh_proc_dointvec_jiffies(ctl, write, 1964 buffer, lenp, ppos); 1965 1966 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) || 1967 (strcmp(ctl->procname, "base_reachable_time_ms") == 0)) 1968 ret = neigh_proc_dointvec_ms_jiffies(ctl, write, 1969 buffer, lenp, ppos); 1970 else 1971 ret = -1; 1972 1973 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) { 1974 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)) 1975 idev->nd_parms->reachable_time = 1976 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)); 1977 idev->tstamp = jiffies; 1978 inet6_ifinfo_notify(RTM_NEWLINK, idev); 1979 in6_dev_put(idev); 1980 } 1981 return ret; 1982 } 1983 1984 1985 #endif 1986 1987 static int __net_init ndisc_net_init(struct net *net) 1988 { 1989 struct ipv6_pinfo *np; 1990 struct sock *sk; 1991 int err; 1992 1993 err = inet_ctl_sock_create(&sk, PF_INET6, 1994 SOCK_RAW, IPPROTO_ICMPV6, net); 1995 if (err < 0) { 1996 ND_PRINTK(0, err, 1997 "NDISC: Failed to initialize the control socket (err %d)\n", 1998 err); 1999 return err; 2000 } 2001 2002 net->ipv6.ndisc_sk = sk; 2003 2004 np = inet6_sk(sk); 2005 np->hop_limit = 255; 2006 /* Do not loopback ndisc messages */ 2007 np->mc_loop = 0; 2008 2009 return 0; 2010 } 2011 2012 static void __net_exit ndisc_net_exit(struct net *net) 2013 { 2014 inet_ctl_sock_destroy(net->ipv6.ndisc_sk); 2015 } 2016 2017 static struct pernet_operations ndisc_net_ops = { 2018 .init = ndisc_net_init, 2019 .exit = ndisc_net_exit, 2020 }; 2021 2022 int __init ndisc_init(void) 2023 { 2024 int err; 2025 2026 err = register_pernet_subsys(&ndisc_net_ops); 2027 if (err) 2028 return err; 2029 /* 2030 * Initialize the neighbour table 2031 */ 2032 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl); 2033 2034 #ifdef CONFIG_SYSCTL 2035 err = neigh_sysctl_register(NULL, &nd_tbl.parms, 2036 ndisc_ifinfo_sysctl_change); 2037 if (err) 2038 goto out_unregister_pernet; 2039 out: 2040 #endif 2041 return err; 2042 2043 #ifdef CONFIG_SYSCTL 2044 out_unregister_pernet: 2045 unregister_pernet_subsys(&ndisc_net_ops); 2046 goto out; 2047 #endif 2048 } 2049 2050 int __init ndisc_late_init(void) 2051 { 2052 return register_netdevice_notifier(&ndisc_netdev_notifier); 2053 } 2054 2055 void ndisc_late_cleanup(void) 2056 { 2057 unregister_netdevice_notifier(&ndisc_netdev_notifier); 2058 } 2059 2060 void ndisc_cleanup(void) 2061 { 2062 #ifdef CONFIG_SYSCTL 2063 neigh_sysctl_unregister(&nd_tbl.parms); 2064 #endif 2065 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl); 2066 unregister_pernet_subsys(&ndisc_net_ops); 2067 } 2068