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 72static u32 ndisc_hash(const void *pkey, 73 const struct net_device *dev, 74 __u32 *hash_rnd); 75static bool ndisc_key_eq(const struct neighbour *neigh, const void *pkey); 76static bool ndisc_allow_add(const struct net_device *dev, 77 struct netlink_ext_ack *extack); 78static int ndisc_constructor(struct neighbour *neigh); 79static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb); 80static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb); 81static int pndisc_constructor(struct pneigh_entry *n); 82static void pndisc_destructor(struct pneigh_entry *n); 83static void pndisc_redo(struct sk_buff *skb); 84static int ndisc_is_multicast(const void *pkey); 85 86static 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 94static 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 103static const struct neigh_ops ndisc_direct_ops = { 104 .family = AF_INET6, 105 .output = neigh_direct_output, 106 .connected_output = neigh_direct_output, 107}; 108 109struct 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}; 144EXPORT_SYMBOL_GPL(nd_tbl); 145 146void __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} 166EXPORT_SYMBOL_GPL(__ndisc_fill_addr_option); 167 168static 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 176static 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 184static 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 197static 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 208static 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 220struct 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 } 282next_opt: 283 opt_len -= l; 284 nd_opt = ((void *)nd_opt) + l; 285 } 286 return ndopts; 287} 288 289int 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} 313EXPORT_SYMBOL(ndisc_mc_map); 314 315static 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 322static bool ndisc_key_eq(const struct neighbour *n, const void *pkey) 323{ 324 return neigh_key_eq128(n, pkey); 325} 326 327static 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 375static 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 388static 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 */ 401static 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 414static 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 443static 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 471void 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, inet6_sk(sk)->hop_limit, skb->len); 504 505 rcu_read_lock(); 506 idev = __in6_dev_get(dst->dev); 507 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len); 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} 519EXPORT_SYMBOL(ndisc_send_skb); 520 521void 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 577static 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 603struct 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} 648EXPORT_SYMBOL(ndisc_ns_create); 649 650void 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 670void 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 723static 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 735static 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 763static 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 778void 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 787static 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) { 852have_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 964out: 965 if (ifp) 966 in6_ifa_put(ifp); 967 else 968 in6_dev_put(idev); 969 return reason; 970} 971 972static 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 991static 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; 1124out: 1125 neigh_release(neigh); 1126 } 1127 return reason; 1128} 1129 1130static 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 } 1182out: 1183 return reason; 1184} 1185 1186static 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 1225nla_put_failure: 1226 nlmsg_free(skb); 1227 err = -EMSGSIZE; 1228errout: 1229 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err); 1230} 1231 1232static 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 u32 defrtr_usr_metric; 1241 unsigned int pref = 0; 1242 __u32 old_if_flags; 1243 struct net *net; 1244 SKB_DR(reason); 1245 int lifetime; 1246 int optlen; 1247 1248 __u8 *opt = (__u8 *)(ra_msg + 1); 1249 1250 optlen = (skb_tail_pointer(skb) - skb_transport_header(skb)) - 1251 sizeof(struct ra_msg); 1252 1253 ND_PRINTK(2, info, 1254 "RA: %s, dev: %s\n", 1255 __func__, skb->dev->name); 1256 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1257 ND_PRINTK(2, warn, "RA: source address is not link-local\n"); 1258 return reason; 1259 } 1260 if (optlen < 0) 1261 return SKB_DROP_REASON_PKT_TOO_SMALL; 1262 1263#ifdef CONFIG_IPV6_NDISC_NODETYPE 1264 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) { 1265 ND_PRINTK(2, warn, "RA: from host or unauthorized router\n"); 1266 return reason; 1267 } 1268#endif 1269 1270 in6_dev = __in6_dev_get(skb->dev); 1271 if (!in6_dev) { 1272 ND_PRINTK(0, err, "RA: can't find inet6 device for %s\n", 1273 skb->dev->name); 1274 return reason; 1275 } 1276 1277 if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts)) 1278 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1279 1280 if (!ipv6_accept_ra(in6_dev)) { 1281 ND_PRINTK(2, info, 1282 "RA: %s, did not accept ra for dev: %s\n", 1283 __func__, skb->dev->name); 1284 goto skip_linkparms; 1285 } 1286 1287#ifdef CONFIG_IPV6_NDISC_NODETYPE 1288 /* skip link-specific parameters from interior routers */ 1289 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1290 ND_PRINTK(2, info, 1291 "RA: %s, nodetype is NODEFAULT, dev: %s\n", 1292 __func__, skb->dev->name); 1293 goto skip_linkparms; 1294 } 1295#endif 1296 1297 if (in6_dev->if_flags & IF_RS_SENT) { 1298 /* 1299 * flag that an RA was received after an RS was sent 1300 * out on this interface. 1301 */ 1302 in6_dev->if_flags |= IF_RA_RCVD; 1303 } 1304 1305 /* 1306 * Remember the managed/otherconf flags from most recently 1307 * received RA message (RFC 2462) -- yoshfuji 1308 */ 1309 old_if_flags = in6_dev->if_flags; 1310 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED | 1311 IF_RA_OTHERCONF)) | 1312 (ra_msg->icmph.icmp6_addrconf_managed ? 1313 IF_RA_MANAGED : 0) | 1314 (ra_msg->icmph.icmp6_addrconf_other ? 1315 IF_RA_OTHERCONF : 0); 1316 1317 if (old_if_flags != in6_dev->if_flags) 1318 send_ifinfo_notify = true; 1319 1320 if (!in6_dev->cnf.accept_ra_defrtr) { 1321 ND_PRINTK(2, info, 1322 "RA: %s, defrtr is false for dev: %s\n", 1323 __func__, skb->dev->name); 1324 goto skip_defrtr; 1325 } 1326 1327 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); 1328 if (lifetime != 0 && lifetime < in6_dev->cnf.accept_ra_min_lft) { 1329 ND_PRINTK(2, info, 1330 "RA: router lifetime (%ds) is too short: %s\n", 1331 lifetime, skb->dev->name); 1332 goto skip_defrtr; 1333 } 1334 1335 /* Do not accept RA with source-addr found on local machine unless 1336 * accept_ra_from_local is set to true. 1337 */ 1338 net = dev_net(in6_dev->dev); 1339 if (!in6_dev->cnf.accept_ra_from_local && 1340 ipv6_chk_addr(net, &ipv6_hdr(skb)->saddr, in6_dev->dev, 0)) { 1341 ND_PRINTK(2, info, 1342 "RA from local address detected on dev: %s: default router ignored\n", 1343 skb->dev->name); 1344 goto skip_defrtr; 1345 } 1346 1347#ifdef CONFIG_IPV6_ROUTER_PREF 1348 pref = ra_msg->icmph.icmp6_router_pref; 1349 /* 10b is handled as if it were 00b (medium) */ 1350 if (pref == ICMPV6_ROUTER_PREF_INVALID || 1351 !in6_dev->cnf.accept_ra_rtr_pref) 1352 pref = ICMPV6_ROUTER_PREF_MEDIUM; 1353#endif 1354 /* routes added from RAs do not use nexthop objects */ 1355 rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev); 1356 if (rt) { 1357 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6, 1358 rt->fib6_nh->fib_nh_dev, NULL, 1359 &ipv6_hdr(skb)->saddr); 1360 if (!neigh) { 1361 ND_PRINTK(0, err, 1362 "RA: %s got default router without neighbour\n", 1363 __func__); 1364 fib6_info_release(rt); 1365 return reason; 1366 } 1367 } 1368 /* Set default route metric as specified by user */ 1369 defrtr_usr_metric = in6_dev->cnf.ra_defrtr_metric; 1370 /* delete the route if lifetime is 0 or if metric needs change */ 1371 if (rt && (lifetime == 0 || rt->fib6_metric != defrtr_usr_metric)) { 1372 ip6_del_rt(net, rt, false); 1373 rt = NULL; 1374 } 1375 1376 ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n", 1377 rt, lifetime, defrtr_usr_metric, skb->dev->name); 1378 if (!rt && lifetime) { 1379 ND_PRINTK(3, info, "RA: adding default router\n"); 1380 1381 if (neigh) 1382 neigh_release(neigh); 1383 1384 rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr, 1385 skb->dev, pref, defrtr_usr_metric); 1386 if (!rt) { 1387 ND_PRINTK(0, err, 1388 "RA: %s failed to add default route\n", 1389 __func__); 1390 return reason; 1391 } 1392 1393 neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6, 1394 rt->fib6_nh->fib_nh_dev, NULL, 1395 &ipv6_hdr(skb)->saddr); 1396 if (!neigh) { 1397 ND_PRINTK(0, err, 1398 "RA: %s got default router without neighbour\n", 1399 __func__); 1400 fib6_info_release(rt); 1401 return reason; 1402 } 1403 neigh->flags |= NTF_ROUTER; 1404 } else if (rt && IPV6_EXTRACT_PREF(rt->fib6_flags) != pref) { 1405 struct nl_info nlinfo = { 1406 .nl_net = net, 1407 }; 1408 rt->fib6_flags = (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 1409 inet6_rt_notify(RTM_NEWROUTE, rt, &nlinfo, NLM_F_REPLACE); 1410 } 1411 1412 if (rt) 1413 fib6_set_expires(rt, jiffies + (HZ * lifetime)); 1414 if (in6_dev->cnf.accept_ra_min_hop_limit < 256 && 1415 ra_msg->icmph.icmp6_hop_limit) { 1416 if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) { 1417 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit; 1418 fib6_metric_set(rt, RTAX_HOPLIMIT, 1419 ra_msg->icmph.icmp6_hop_limit); 1420 } else { 1421 ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n"); 1422 } 1423 } 1424 1425skip_defrtr: 1426 1427 /* 1428 * Update Reachable Time and Retrans Timer 1429 */ 1430 1431 if (in6_dev->nd_parms) { 1432 unsigned long rtime = ntohl(ra_msg->retrans_timer); 1433 1434 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) { 1435 rtime = (rtime*HZ)/1000; 1436 if (rtime < HZ/100) 1437 rtime = HZ/100; 1438 NEIGH_VAR_SET(in6_dev->nd_parms, RETRANS_TIME, rtime); 1439 in6_dev->tstamp = jiffies; 1440 send_ifinfo_notify = true; 1441 } 1442 1443 rtime = ntohl(ra_msg->reachable_time); 1444 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) { 1445 rtime = (rtime*HZ)/1000; 1446 1447 if (rtime < HZ/10) 1448 rtime = HZ/10; 1449 1450 if (rtime != NEIGH_VAR(in6_dev->nd_parms, BASE_REACHABLE_TIME)) { 1451 NEIGH_VAR_SET(in6_dev->nd_parms, 1452 BASE_REACHABLE_TIME, rtime); 1453 NEIGH_VAR_SET(in6_dev->nd_parms, 1454 GC_STALETIME, 3 * rtime); 1455 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime); 1456 in6_dev->tstamp = jiffies; 1457 send_ifinfo_notify = true; 1458 } 1459 } 1460 } 1461 1462skip_linkparms: 1463 1464 /* 1465 * Process options. 1466 */ 1467 1468 if (!neigh) 1469 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr, 1470 skb->dev, 1); 1471 if (neigh) { 1472 u8 *lladdr = NULL; 1473 if (ndopts.nd_opts_src_lladdr) { 1474 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1475 skb->dev); 1476 if (!lladdr) { 1477 ND_PRINTK(2, warn, 1478 "RA: invalid link-layer address length\n"); 1479 goto out; 1480 } 1481 } 1482 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE, 1483 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1484 NEIGH_UPDATE_F_OVERRIDE| 1485 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1486 NEIGH_UPDATE_F_ISROUTER, 1487 NDISC_ROUTER_ADVERTISEMENT, &ndopts); 1488 reason = SKB_CONSUMED; 1489 } 1490 1491 if (!ipv6_accept_ra(in6_dev)) { 1492 ND_PRINTK(2, info, 1493 "RA: %s, accept_ra is false for dev: %s\n", 1494 __func__, skb->dev->name); 1495 goto out; 1496 } 1497 1498#ifdef CONFIG_IPV6_ROUTE_INFO 1499 if (!in6_dev->cnf.accept_ra_from_local && 1500 ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, 1501 in6_dev->dev, 0)) { 1502 ND_PRINTK(2, info, 1503 "RA from local address detected on dev: %s: router info ignored.\n", 1504 skb->dev->name); 1505 goto skip_routeinfo; 1506 } 1507 1508 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) { 1509 struct nd_opt_hdr *p; 1510 for (p = ndopts.nd_opts_ri; 1511 p; 1512 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) { 1513 struct route_info *ri = (struct route_info *)p; 1514#ifdef CONFIG_IPV6_NDISC_NODETYPE 1515 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT && 1516 ri->prefix_len == 0) 1517 continue; 1518#endif 1519 if (ri->prefix_len == 0 && 1520 !in6_dev->cnf.accept_ra_defrtr) 1521 continue; 1522 if (ri->lifetime != 0 && 1523 ntohl(ri->lifetime) < in6_dev->cnf.accept_ra_min_lft) 1524 continue; 1525 if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen) 1526 continue; 1527 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen) 1528 continue; 1529 rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3, 1530 &ipv6_hdr(skb)->saddr); 1531 } 1532 } 1533 1534skip_routeinfo: 1535#endif 1536 1537#ifdef CONFIG_IPV6_NDISC_NODETYPE 1538 /* skip link-specific ndopts from interior routers */ 1539 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) { 1540 ND_PRINTK(2, info, 1541 "RA: %s, nodetype is NODEFAULT (interior routes), dev: %s\n", 1542 __func__, skb->dev->name); 1543 goto out; 1544 } 1545#endif 1546 1547 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) { 1548 struct nd_opt_hdr *p; 1549 for (p = ndopts.nd_opts_pi; 1550 p; 1551 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) { 1552 addrconf_prefix_rcv(skb->dev, (u8 *)p, 1553 (p->nd_opt_len) << 3, 1554 ndopts.nd_opts_src_lladdr != NULL); 1555 } 1556 } 1557 1558 if (ndopts.nd_opts_mtu && in6_dev->cnf.accept_ra_mtu) { 1559 __be32 n; 1560 u32 mtu; 1561 1562 memcpy(&n, ((u8 *)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); 1563 mtu = ntohl(n); 1564 1565 if (in6_dev->ra_mtu != mtu) { 1566 in6_dev->ra_mtu = mtu; 1567 send_ifinfo_notify = true; 1568 } 1569 1570 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { 1571 ND_PRINTK(2, warn, "RA: invalid mtu: %d\n", mtu); 1572 } else if (in6_dev->cnf.mtu6 != mtu) { 1573 in6_dev->cnf.mtu6 = mtu; 1574 fib6_metric_set(rt, RTAX_MTU, mtu); 1575 rt6_mtu_change(skb->dev, mtu); 1576 } 1577 } 1578 1579 if (ndopts.nd_useropts) { 1580 struct nd_opt_hdr *p; 1581 for (p = ndopts.nd_useropts; 1582 p; 1583 p = ndisc_next_useropt(skb->dev, p, 1584 ndopts.nd_useropts_end)) { 1585 ndisc_ra_useropt(skb, p); 1586 } 1587 } 1588 1589 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { 1590 ND_PRINTK(2, warn, "RA: invalid RA options\n"); 1591 } 1592out: 1593 /* Send a notify if RA changed managed/otherconf flags or 1594 * timer settings or ra_mtu value 1595 */ 1596 if (send_ifinfo_notify) 1597 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1598 1599 fib6_info_release(rt); 1600 if (neigh) 1601 neigh_release(neigh); 1602 return reason; 1603} 1604 1605static enum skb_drop_reason ndisc_redirect_rcv(struct sk_buff *skb) 1606{ 1607 struct rd_msg *msg = (struct rd_msg *)skb_transport_header(skb); 1608 u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + 1609 offsetof(struct rd_msg, opt)); 1610 struct ndisc_options ndopts; 1611 SKB_DR(reason); 1612 u8 *hdr; 1613 1614#ifdef CONFIG_IPV6_NDISC_NODETYPE 1615 switch (skb->ndisc_nodetype) { 1616 case NDISC_NODETYPE_HOST: 1617 case NDISC_NODETYPE_NODEFAULT: 1618 ND_PRINTK(2, warn, 1619 "Redirect: from host or unauthorized router\n"); 1620 return reason; 1621 } 1622#endif 1623 1624 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1625 ND_PRINTK(2, warn, 1626 "Redirect: source address is not link-local\n"); 1627 return reason; 1628 } 1629 1630 if (!ndisc_parse_options(skb->dev, msg->opt, ndoptlen, &ndopts)) 1631 return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS; 1632 1633 if (!ndopts.nd_opts_rh) { 1634 ip6_redirect_no_header(skb, dev_net(skb->dev), 1635 skb->dev->ifindex); 1636 return reason; 1637 } 1638 1639 hdr = (u8 *)ndopts.nd_opts_rh; 1640 hdr += 8; 1641 if (!pskb_pull(skb, hdr - skb_transport_header(skb))) 1642 return SKB_DROP_REASON_PKT_TOO_SMALL; 1643 1644 return icmpv6_notify(skb, NDISC_REDIRECT, 0, 0); 1645} 1646 1647static void ndisc_fill_redirect_hdr_option(struct sk_buff *skb, 1648 struct sk_buff *orig_skb, 1649 int rd_len) 1650{ 1651 u8 *opt = skb_put(skb, rd_len); 1652 1653 memset(opt, 0, 8); 1654 *(opt++) = ND_OPT_REDIRECT_HDR; 1655 *(opt++) = (rd_len >> 3); 1656 opt += 6; 1657 1658 skb_copy_bits(orig_skb, skb_network_offset(orig_skb), opt, 1659 rd_len - 8); 1660} 1661 1662void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target) 1663{ 1664 struct net_device *dev = skb->dev; 1665 struct net *net = dev_net(dev); 1666 struct sock *sk = net->ipv6.ndisc_sk; 1667 int optlen = 0; 1668 struct inet_peer *peer; 1669 struct sk_buff *buff; 1670 struct rd_msg *msg; 1671 struct in6_addr saddr_buf; 1672 struct rt6_info *rt; 1673 struct dst_entry *dst; 1674 struct flowi6 fl6; 1675 int rd_len; 1676 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL, 1677 ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL; 1678 bool ret; 1679 1680 if (netif_is_l3_master(skb->dev)) { 1681 dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif); 1682 if (!dev) 1683 return; 1684 } 1685 1686 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) { 1687 ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n", 1688 dev->name); 1689 return; 1690 } 1691 1692 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) && 1693 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1694 ND_PRINTK(2, warn, 1695 "Redirect: target address is not link-local unicast\n"); 1696 return; 1697 } 1698 1699 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT, 1700 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex); 1701 1702 dst = ip6_route_output(net, NULL, &fl6); 1703 if (dst->error) { 1704 dst_release(dst); 1705 return; 1706 } 1707 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); 1708 if (IS_ERR(dst)) 1709 return; 1710 1711 rt = (struct rt6_info *) dst; 1712 1713 if (rt->rt6i_flags & RTF_GATEWAY) { 1714 ND_PRINTK(2, warn, 1715 "Redirect: destination is not a neighbour\n"); 1716 goto release; 1717 } 1718 peer = inet_getpeer_v6(net->ipv6.peers, &ipv6_hdr(skb)->saddr, 1); 1719 ret = inet_peer_xrlim_allow(peer, 1*HZ); 1720 if (peer) 1721 inet_putpeer(peer); 1722 if (!ret) 1723 goto release; 1724 1725 if (dev->addr_len) { 1726 struct neighbour *neigh = dst_neigh_lookup(skb_dst(skb), target); 1727 if (!neigh) { 1728 ND_PRINTK(2, warn, 1729 "Redirect: no neigh for target address\n"); 1730 goto release; 1731 } 1732 1733 read_lock_bh(&neigh->lock); 1734 if (neigh->nud_state & NUD_VALID) { 1735 memcpy(ha_buf, neigh->ha, dev->addr_len); 1736 read_unlock_bh(&neigh->lock); 1737 ha = ha_buf; 1738 optlen += ndisc_redirect_opt_addr_space(dev, neigh, 1739 ops_data_buf, 1740 &ops_data); 1741 } else 1742 read_unlock_bh(&neigh->lock); 1743 1744 neigh_release(neigh); 1745 } 1746 1747 rd_len = min_t(unsigned int, 1748 IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(*msg) - optlen, 1749 skb->len + 8); 1750 rd_len &= ~0x7; 1751 optlen += rd_len; 1752 1753 buff = ndisc_alloc_skb(dev, sizeof(*msg) + optlen); 1754 if (!buff) 1755 goto release; 1756 1757 msg = skb_put(buff, sizeof(*msg)); 1758 *msg = (struct rd_msg) { 1759 .icmph = { 1760 .icmp6_type = NDISC_REDIRECT, 1761 }, 1762 .target = *target, 1763 .dest = ipv6_hdr(skb)->daddr, 1764 }; 1765 1766 /* 1767 * include target_address option 1768 */ 1769 1770 if (ha) 1771 ndisc_fill_redirect_addr_option(buff, ha, ops_data); 1772 1773 /* 1774 * build redirect option and copy skb over to the new packet. 1775 */ 1776 1777 if (rd_len) 1778 ndisc_fill_redirect_hdr_option(buff, skb, rd_len); 1779 1780 skb_dst_set(buff, dst); 1781 ndisc_send_skb(buff, &ipv6_hdr(skb)->saddr, &saddr_buf); 1782 return; 1783 1784release: 1785 dst_release(dst); 1786} 1787 1788static void pndisc_redo(struct sk_buff *skb) 1789{ 1790 enum skb_drop_reason reason = ndisc_recv_ns(skb); 1791 1792 kfree_skb_reason(skb, reason); 1793} 1794 1795static int ndisc_is_multicast(const void *pkey) 1796{ 1797 return ipv6_addr_is_multicast((struct in6_addr *)pkey); 1798} 1799 1800static bool ndisc_suppress_frag_ndisc(struct sk_buff *skb) 1801{ 1802 struct inet6_dev *idev = __in6_dev_get(skb->dev); 1803 1804 if (!idev) 1805 return true; 1806 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED && 1807 idev->cnf.suppress_frag_ndisc) { 1808 net_warn_ratelimited("Received fragmented ndisc packet. Carefully consider disabling suppress_frag_ndisc.\n"); 1809 return true; 1810 } 1811 return false; 1812} 1813 1814enum skb_drop_reason ndisc_rcv(struct sk_buff *skb) 1815{ 1816 struct nd_msg *msg; 1817 SKB_DR(reason); 1818 1819 if (ndisc_suppress_frag_ndisc(skb)) 1820 return SKB_DROP_REASON_IPV6_NDISC_FRAG; 1821 1822 if (skb_linearize(skb)) 1823 return SKB_DROP_REASON_NOMEM; 1824 1825 msg = (struct nd_msg *)skb_transport_header(skb); 1826 1827 __skb_push(skb, skb->data - skb_transport_header(skb)); 1828 1829 if (ipv6_hdr(skb)->hop_limit != 255) { 1830 ND_PRINTK(2, warn, "NDISC: invalid hop-limit: %d\n", 1831 ipv6_hdr(skb)->hop_limit); 1832 return SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT; 1833 } 1834 1835 if (msg->icmph.icmp6_code != 0) { 1836 ND_PRINTK(2, warn, "NDISC: invalid ICMPv6 code: %d\n", 1837 msg->icmph.icmp6_code); 1838 return SKB_DROP_REASON_IPV6_NDISC_BAD_CODE; 1839 } 1840 1841 switch (msg->icmph.icmp6_type) { 1842 case NDISC_NEIGHBOUR_SOLICITATION: 1843 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 1844 reason = ndisc_recv_ns(skb); 1845 break; 1846 1847 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1848 reason = ndisc_recv_na(skb); 1849 break; 1850 1851 case NDISC_ROUTER_SOLICITATION: 1852 reason = ndisc_recv_rs(skb); 1853 break; 1854 1855 case NDISC_ROUTER_ADVERTISEMENT: 1856 reason = ndisc_router_discovery(skb); 1857 break; 1858 1859 case NDISC_REDIRECT: 1860 reason = ndisc_redirect_rcv(skb); 1861 break; 1862 } 1863 1864 return reason; 1865} 1866 1867static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1868{ 1869 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1870 struct netdev_notifier_change_info *change_info; 1871 struct net *net = dev_net(dev); 1872 struct inet6_dev *idev; 1873 bool evict_nocarrier; 1874 1875 switch (event) { 1876 case NETDEV_CHANGEADDR: 1877 neigh_changeaddr(&nd_tbl, dev); 1878 fib6_run_gc(0, net, false); 1879 fallthrough; 1880 case NETDEV_UP: 1881 idev = in6_dev_get(dev); 1882 if (!idev) 1883 break; 1884 if (idev->cnf.ndisc_notify || 1885 net->ipv6.devconf_all->ndisc_notify) 1886 ndisc_send_unsol_na(dev); 1887 in6_dev_put(idev); 1888 break; 1889 case NETDEV_CHANGE: 1890 idev = in6_dev_get(dev); 1891 if (!idev) 1892 evict_nocarrier = true; 1893 else { 1894 evict_nocarrier = idev->cnf.ndisc_evict_nocarrier && 1895 net->ipv6.devconf_all->ndisc_evict_nocarrier; 1896 in6_dev_put(idev); 1897 } 1898 1899 change_info = ptr; 1900 if (change_info->flags_changed & IFF_NOARP) 1901 neigh_changeaddr(&nd_tbl, dev); 1902 if (evict_nocarrier && !netif_carrier_ok(dev)) 1903 neigh_carrier_down(&nd_tbl, dev); 1904 break; 1905 case NETDEV_DOWN: 1906 neigh_ifdown(&nd_tbl, dev); 1907 fib6_run_gc(0, net, false); 1908 break; 1909 case NETDEV_NOTIFY_PEERS: 1910 ndisc_send_unsol_na(dev); 1911 break; 1912 default: 1913 break; 1914 } 1915 1916 return NOTIFY_DONE; 1917} 1918 1919static struct notifier_block ndisc_netdev_notifier = { 1920 .notifier_call = ndisc_netdev_event, 1921 .priority = ADDRCONF_NOTIFY_PRIORITY - 5, 1922}; 1923 1924#ifdef CONFIG_SYSCTL 1925static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl, 1926 const char *func, const char *dev_name) 1927{ 1928 static char warncomm[TASK_COMM_LEN]; 1929 static int warned; 1930 if (strcmp(warncomm, current->comm) && warned < 5) { 1931 strcpy(warncomm, current->comm); 1932 pr_warn("process `%s' is using deprecated sysctl (%s) net.ipv6.neigh.%s.%s - use net.ipv6.neigh.%s.%s_ms instead\n", 1933 warncomm, func, 1934 dev_name, ctl->procname, 1935 dev_name, ctl->procname); 1936 warned++; 1937 } 1938} 1939 1940int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer, 1941 size_t *lenp, loff_t *ppos) 1942{ 1943 struct net_device *dev = ctl->extra1; 1944 struct inet6_dev *idev; 1945 int ret; 1946 1947 if ((strcmp(ctl->procname, "retrans_time") == 0) || 1948 (strcmp(ctl->procname, "base_reachable_time") == 0)) 1949 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default"); 1950 1951 if (strcmp(ctl->procname, "retrans_time") == 0) 1952 ret = neigh_proc_dointvec(ctl, write, buffer, lenp, ppos); 1953 1954 else if (strcmp(ctl->procname, "base_reachable_time") == 0) 1955 ret = neigh_proc_dointvec_jiffies(ctl, write, 1956 buffer, lenp, ppos); 1957 1958 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) || 1959 (strcmp(ctl->procname, "base_reachable_time_ms") == 0)) 1960 ret = neigh_proc_dointvec_ms_jiffies(ctl, write, 1961 buffer, lenp, ppos); 1962 else 1963 ret = -1; 1964 1965 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) { 1966 if (ctl->data == &NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)) 1967 idev->nd_parms->reachable_time = 1968 neigh_rand_reach_time(NEIGH_VAR(idev->nd_parms, BASE_REACHABLE_TIME)); 1969 idev->tstamp = jiffies; 1970 inet6_ifinfo_notify(RTM_NEWLINK, idev); 1971 in6_dev_put(idev); 1972 } 1973 return ret; 1974} 1975 1976 1977#endif 1978 1979static int __net_init ndisc_net_init(struct net *net) 1980{ 1981 struct ipv6_pinfo *np; 1982 struct sock *sk; 1983 int err; 1984 1985 err = inet_ctl_sock_create(&sk, PF_INET6, 1986 SOCK_RAW, IPPROTO_ICMPV6, net); 1987 if (err < 0) { 1988 ND_PRINTK(0, err, 1989 "NDISC: Failed to initialize the control socket (err %d)\n", 1990 err); 1991 return err; 1992 } 1993 1994 net->ipv6.ndisc_sk = sk; 1995 1996 np = inet6_sk(sk); 1997 np->hop_limit = 255; 1998 /* Do not loopback ndisc messages */ 1999 np->mc_loop = 0; 2000 2001 return 0; 2002} 2003 2004static void __net_exit ndisc_net_exit(struct net *net) 2005{ 2006 inet_ctl_sock_destroy(net->ipv6.ndisc_sk); 2007} 2008 2009static struct pernet_operations ndisc_net_ops = { 2010 .init = ndisc_net_init, 2011 .exit = ndisc_net_exit, 2012}; 2013 2014int __init ndisc_init(void) 2015{ 2016 int err; 2017 2018 err = register_pernet_subsys(&ndisc_net_ops); 2019 if (err) 2020 return err; 2021 /* 2022 * Initialize the neighbour table 2023 */ 2024 neigh_table_init(NEIGH_ND_TABLE, &nd_tbl); 2025 2026#ifdef CONFIG_SYSCTL 2027 err = neigh_sysctl_register(NULL, &nd_tbl.parms, 2028 ndisc_ifinfo_sysctl_change); 2029 if (err) 2030 goto out_unregister_pernet; 2031out: 2032#endif 2033 return err; 2034 2035#ifdef CONFIG_SYSCTL 2036out_unregister_pernet: 2037 unregister_pernet_subsys(&ndisc_net_ops); 2038 goto out; 2039#endif 2040} 2041 2042int __init ndisc_late_init(void) 2043{ 2044 return register_netdevice_notifier(&ndisc_netdev_notifier); 2045} 2046 2047void ndisc_late_cleanup(void) 2048{ 2049 unregister_netdevice_notifier(&ndisc_netdev_notifier); 2050} 2051 2052void ndisc_cleanup(void) 2053{ 2054#ifdef CONFIG_SYSCTL 2055 neigh_sysctl_unregister(&nd_tbl.parms); 2056#endif 2057 neigh_table_clear(NEIGH_ND_TABLE, &nd_tbl); 2058 unregister_pernet_subsys(&ndisc_net_ops); 2059} 2060