1 /* 2 * Neighbour Discovery for IPv6 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * Mike Shaver <shaver@ingenia.com> 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License 11 * as published by the Free Software Foundation; either version 12 * 2 of the License, or (at your option) any later version. 13 */ 14 15 /* 16 * Changes: 17 * 18 * Pierre Ynard : export userland ND options 19 * through netlink (RDNSS support) 20 * Lars Fenneberg : fixed MTU setting on receipt 21 * of an RA. 22 * Janos Farkas : kmalloc failure checks 23 * Alexey Kuznetsov : state machine reworked 24 * and moved to net/core. 25 * Pekka Savola : RFC2461 validation 26 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly 27 */ 28 29 /* Set to 3 to get tracing... */ 30 #define ND_DEBUG 1 31 32 #define ND_PRINTK(fmt, args...) do { if (net_ratelimit()) { printk(fmt, ## args); } } while(0) 33 #define ND_NOPRINTK(x...) do { ; } while(0) 34 #define ND_PRINTK0 ND_PRINTK 35 #define ND_PRINTK1 ND_NOPRINTK 36 #define ND_PRINTK2 ND_NOPRINTK 37 #define ND_PRINTK3 ND_NOPRINTK 38 #if ND_DEBUG >= 1 39 #undef ND_PRINTK1 40 #define ND_PRINTK1 ND_PRINTK 41 #endif 42 #if ND_DEBUG >= 2 43 #undef ND_PRINTK2 44 #define ND_PRINTK2 ND_PRINTK 45 #endif 46 #if ND_DEBUG >= 3 47 #undef ND_PRINTK3 48 #define ND_PRINTK3 ND_PRINTK 49 #endif 50 51 #include <linux/module.h> 52 #include <linux/errno.h> 53 #include <linux/types.h> 54 #include <linux/socket.h> 55 #include <linux/sockios.h> 56 #include <linux/sched.h> 57 #include <linux/net.h> 58 #include <linux/in6.h> 59 #include <linux/route.h> 60 #include <linux/init.h> 61 #include <linux/rcupdate.h> 62 #include <linux/slab.h> 63 #ifdef CONFIG_SYSCTL 64 #include <linux/sysctl.h> 65 #endif 66 67 #include <linux/if_addr.h> 68 #include <linux/if_arp.h> 69 #include <linux/ipv6.h> 70 #include <linux/icmpv6.h> 71 #include <linux/jhash.h> 72 73 #include <net/sock.h> 74 #include <net/snmp.h> 75 76 #include <net/ipv6.h> 77 #include <net/protocol.h> 78 #include <net/ndisc.h> 79 #include <net/ip6_route.h> 80 #include <net/addrconf.h> 81 #include <net/icmp.h> 82 83 #include <net/netlink.h> 84 #include <linux/rtnetlink.h> 85 86 #include <net/flow.h> 87 #include <net/ip6_checksum.h> 88 #include <net/inet_common.h> 89 #include <linux/proc_fs.h> 90 91 #include <linux/netfilter.h> 92 #include <linux/netfilter_ipv6.h> 93 94 static u32 ndisc_hash(const void *pkey, 95 const struct net_device *dev, 96 __u32 *hash_rnd); 97 static int ndisc_constructor(struct neighbour *neigh); 98 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb); 99 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb); 100 static int pndisc_constructor(struct pneigh_entry *n); 101 static void pndisc_destructor(struct pneigh_entry *n); 102 static void pndisc_redo(struct sk_buff *skb); 103 104 static const struct neigh_ops ndisc_generic_ops = { 105 .family = AF_INET6, 106 .solicit = ndisc_solicit, 107 .error_report = ndisc_error_report, 108 .output = neigh_resolve_output, 109 .connected_output = neigh_connected_output, 110 }; 111 112 static const struct neigh_ops ndisc_hh_ops = { 113 .family = AF_INET6, 114 .solicit = ndisc_solicit, 115 .error_report = ndisc_error_report, 116 .output = neigh_resolve_output, 117 .connected_output = neigh_resolve_output, 118 }; 119 120 121 static const struct neigh_ops ndisc_direct_ops = { 122 .family = AF_INET6, 123 .output = neigh_direct_output, 124 .connected_output = neigh_direct_output, 125 }; 126 127 struct neigh_table nd_tbl = { 128 .family = AF_INET6, 129 .key_len = sizeof(struct in6_addr), 130 .hash = ndisc_hash, 131 .constructor = ndisc_constructor, 132 .pconstructor = pndisc_constructor, 133 .pdestructor = pndisc_destructor, 134 .proxy_redo = pndisc_redo, 135 .id = "ndisc_cache", 136 .parms = { 137 .tbl = &nd_tbl, 138 .base_reachable_time = ND_REACHABLE_TIME, 139 .retrans_time = ND_RETRANS_TIMER, 140 .gc_staletime = 60 * HZ, 141 .reachable_time = ND_REACHABLE_TIME, 142 .delay_probe_time = 5 * HZ, 143 .queue_len_bytes = 64*1024, 144 .ucast_probes = 3, 145 .mcast_probes = 3, 146 .anycast_delay = 1 * HZ, 147 .proxy_delay = (8 * HZ) / 10, 148 .proxy_qlen = 64, 149 }, 150 .gc_interval = 30 * HZ, 151 .gc_thresh1 = 128, 152 .gc_thresh2 = 512, 153 .gc_thresh3 = 1024, 154 }; 155 156 /* ND options */ 157 struct ndisc_options { 158 struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX]; 159 #ifdef CONFIG_IPV6_ROUTE_INFO 160 struct nd_opt_hdr *nd_opts_ri; 161 struct nd_opt_hdr *nd_opts_ri_end; 162 #endif 163 struct nd_opt_hdr *nd_useropts; 164 struct nd_opt_hdr *nd_useropts_end; 165 }; 166 167 #define nd_opts_src_lladdr nd_opt_array[ND_OPT_SOURCE_LL_ADDR] 168 #define nd_opts_tgt_lladdr nd_opt_array[ND_OPT_TARGET_LL_ADDR] 169 #define nd_opts_pi nd_opt_array[ND_OPT_PREFIX_INFO] 170 #define nd_opts_pi_end nd_opt_array[__ND_OPT_PREFIX_INFO_END] 171 #define nd_opts_rh nd_opt_array[ND_OPT_REDIRECT_HDR] 172 #define nd_opts_mtu nd_opt_array[ND_OPT_MTU] 173 174 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7) 175 176 /* 177 * Return the padding between the option length and the start of the 178 * link addr. Currently only IP-over-InfiniBand needs this, although 179 * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may 180 * also need a pad of 2. 181 */ 182 static int ndisc_addr_option_pad(unsigned short type) 183 { 184 switch (type) { 185 case ARPHRD_INFINIBAND: return 2; 186 default: return 0; 187 } 188 } 189 190 static inline int ndisc_opt_addr_space(struct net_device *dev) 191 { 192 return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type)); 193 } 194 195 static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len, 196 unsigned short addr_type) 197 { 198 int space = NDISC_OPT_SPACE(data_len); 199 int pad = ndisc_addr_option_pad(addr_type); 200 201 opt[0] = type; 202 opt[1] = space>>3; 203 204 memset(opt + 2, 0, pad); 205 opt += pad; 206 space -= pad; 207 208 memcpy(opt+2, data, data_len); 209 data_len += 2; 210 opt += data_len; 211 if ((space -= data_len) > 0) 212 memset(opt, 0, space); 213 return opt + space; 214 } 215 216 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur, 217 struct nd_opt_hdr *end) 218 { 219 int type; 220 if (!cur || !end || cur >= end) 221 return NULL; 222 type = cur->nd_opt_type; 223 do { 224 cur = ((void *)cur) + (cur->nd_opt_len << 3); 225 } while(cur < end && cur->nd_opt_type != type); 226 return cur <= end && cur->nd_opt_type == type ? cur : NULL; 227 } 228 229 static inline int ndisc_is_useropt(struct nd_opt_hdr *opt) 230 { 231 return opt->nd_opt_type == ND_OPT_RDNSS; 232 } 233 234 static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur, 235 struct nd_opt_hdr *end) 236 { 237 if (!cur || !end || cur >= end) 238 return NULL; 239 do { 240 cur = ((void *)cur) + (cur->nd_opt_len << 3); 241 } while(cur < end && !ndisc_is_useropt(cur)); 242 return cur <= end && ndisc_is_useropt(cur) ? cur : NULL; 243 } 244 245 static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len, 246 struct ndisc_options *ndopts) 247 { 248 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt; 249 250 if (!nd_opt || opt_len < 0 || !ndopts) 251 return NULL; 252 memset(ndopts, 0, sizeof(*ndopts)); 253 while (opt_len) { 254 int l; 255 if (opt_len < sizeof(struct nd_opt_hdr)) 256 return NULL; 257 l = nd_opt->nd_opt_len << 3; 258 if (opt_len < l || l == 0) 259 return NULL; 260 switch (nd_opt->nd_opt_type) { 261 case ND_OPT_SOURCE_LL_ADDR: 262 case ND_OPT_TARGET_LL_ADDR: 263 case ND_OPT_MTU: 264 case ND_OPT_REDIRECT_HDR: 265 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { 266 ND_PRINTK2(KERN_WARNING 267 "%s(): duplicated ND6 option found: type=%d\n", 268 __func__, 269 nd_opt->nd_opt_type); 270 } else { 271 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; 272 } 273 break; 274 case ND_OPT_PREFIX_INFO: 275 ndopts->nd_opts_pi_end = nd_opt; 276 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type]) 277 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; 278 break; 279 #ifdef CONFIG_IPV6_ROUTE_INFO 280 case ND_OPT_ROUTE_INFO: 281 ndopts->nd_opts_ri_end = nd_opt; 282 if (!ndopts->nd_opts_ri) 283 ndopts->nd_opts_ri = nd_opt; 284 break; 285 #endif 286 default: 287 if (ndisc_is_useropt(nd_opt)) { 288 ndopts->nd_useropts_end = nd_opt; 289 if (!ndopts->nd_useropts) 290 ndopts->nd_useropts = nd_opt; 291 } else { 292 /* 293 * Unknown options must be silently ignored, 294 * to accommodate future extension to the 295 * protocol. 296 */ 297 ND_PRINTK2(KERN_NOTICE 298 "%s(): ignored unsupported option; type=%d, len=%d\n", 299 __func__, 300 nd_opt->nd_opt_type, nd_opt->nd_opt_len); 301 } 302 } 303 opt_len -= l; 304 nd_opt = ((void *)nd_opt) + l; 305 } 306 return ndopts; 307 } 308 309 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p, 310 struct net_device *dev) 311 { 312 u8 *lladdr = (u8 *)(p + 1); 313 int lladdrlen = p->nd_opt_len << 3; 314 int prepad = ndisc_addr_option_pad(dev->type); 315 if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad)) 316 return NULL; 317 return lladdr + prepad; 318 } 319 320 int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev, int dir) 321 { 322 switch (dev->type) { 323 case ARPHRD_ETHER: 324 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */ 325 case ARPHRD_FDDI: 326 ipv6_eth_mc_map(addr, buf); 327 return 0; 328 case ARPHRD_IEEE802_TR: 329 ipv6_tr_mc_map(addr,buf); 330 return 0; 331 case ARPHRD_ARCNET: 332 ipv6_arcnet_mc_map(addr, buf); 333 return 0; 334 case ARPHRD_INFINIBAND: 335 ipv6_ib_mc_map(addr, dev->broadcast, buf); 336 return 0; 337 case ARPHRD_IPGRE: 338 return ipv6_ipgre_mc_map(addr, dev->broadcast, buf); 339 default: 340 if (dir) { 341 memcpy(buf, dev->broadcast, dev->addr_len); 342 return 0; 343 } 344 } 345 return -EINVAL; 346 } 347 348 EXPORT_SYMBOL(ndisc_mc_map); 349 350 static u32 ndisc_hash(const void *pkey, 351 const struct net_device *dev, 352 __u32 *hash_rnd) 353 { 354 return ndisc_hashfn(pkey, dev, hash_rnd); 355 } 356 357 static int ndisc_constructor(struct neighbour *neigh) 358 { 359 struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key; 360 struct net_device *dev = neigh->dev; 361 struct inet6_dev *in6_dev; 362 struct neigh_parms *parms; 363 int is_multicast = ipv6_addr_is_multicast(addr); 364 365 in6_dev = in6_dev_get(dev); 366 if (in6_dev == NULL) { 367 return -EINVAL; 368 } 369 370 parms = in6_dev->nd_parms; 371 __neigh_parms_put(neigh->parms); 372 neigh->parms = neigh_parms_clone(parms); 373 374 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST; 375 if (!dev->header_ops) { 376 neigh->nud_state = NUD_NOARP; 377 neigh->ops = &ndisc_direct_ops; 378 neigh->output = neigh_direct_output; 379 } else { 380 if (is_multicast) { 381 neigh->nud_state = NUD_NOARP; 382 ndisc_mc_map(addr, neigh->ha, dev, 1); 383 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { 384 neigh->nud_state = NUD_NOARP; 385 memcpy(neigh->ha, dev->dev_addr, dev->addr_len); 386 if (dev->flags&IFF_LOOPBACK) 387 neigh->type = RTN_LOCAL; 388 } else if (dev->flags&IFF_POINTOPOINT) { 389 neigh->nud_state = NUD_NOARP; 390 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 391 } 392 if (dev->header_ops->cache) 393 neigh->ops = &ndisc_hh_ops; 394 else 395 neigh->ops = &ndisc_generic_ops; 396 if (neigh->nud_state&NUD_VALID) 397 neigh->output = neigh->ops->connected_output; 398 else 399 neigh->output = neigh->ops->output; 400 } 401 in6_dev_put(in6_dev); 402 return 0; 403 } 404 405 static int pndisc_constructor(struct pneigh_entry *n) 406 { 407 struct in6_addr *addr = (struct in6_addr*)&n->key; 408 struct in6_addr maddr; 409 struct net_device *dev = n->dev; 410 411 if (dev == NULL || __in6_dev_get(dev) == NULL) 412 return -EINVAL; 413 addrconf_addr_solict_mult(addr, &maddr); 414 ipv6_dev_mc_inc(dev, &maddr); 415 return 0; 416 } 417 418 static void pndisc_destructor(struct pneigh_entry *n) 419 { 420 struct in6_addr *addr = (struct in6_addr*)&n->key; 421 struct in6_addr maddr; 422 struct net_device *dev = n->dev; 423 424 if (dev == NULL || __in6_dev_get(dev) == NULL) 425 return; 426 addrconf_addr_solict_mult(addr, &maddr); 427 ipv6_dev_mc_dec(dev, &maddr); 428 } 429 430 struct sk_buff *ndisc_build_skb(struct net_device *dev, 431 const struct in6_addr *daddr, 432 const struct in6_addr *saddr, 433 struct icmp6hdr *icmp6h, 434 const struct in6_addr *target, 435 int llinfo) 436 { 437 struct net *net = dev_net(dev); 438 struct sock *sk = net->ipv6.ndisc_sk; 439 struct sk_buff *skb; 440 struct icmp6hdr *hdr; 441 int hlen = LL_RESERVED_SPACE(dev); 442 int tlen = dev->needed_tailroom; 443 int len; 444 int err; 445 u8 *opt; 446 447 if (!dev->addr_len) 448 llinfo = 0; 449 450 len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0); 451 if (llinfo) 452 len += ndisc_opt_addr_space(dev); 453 454 skb = sock_alloc_send_skb(sk, 455 (MAX_HEADER + sizeof(struct ipv6hdr) + 456 len + hlen + tlen), 457 1, &err); 458 if (!skb) { 459 ND_PRINTK0(KERN_ERR 460 "ICMPv6 ND: %s() failed to allocate an skb, err=%d.\n", 461 __func__, err); 462 return NULL; 463 } 464 465 skb_reserve(skb, hlen); 466 ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len); 467 468 skb->transport_header = skb->tail; 469 skb_put(skb, len); 470 471 hdr = (struct icmp6hdr *)skb_transport_header(skb); 472 memcpy(hdr, icmp6h, sizeof(*hdr)); 473 474 opt = skb_transport_header(skb) + sizeof(struct icmp6hdr); 475 if (target) { 476 *(struct in6_addr *)opt = *target; 477 opt += sizeof(*target); 478 } 479 480 if (llinfo) 481 ndisc_fill_addr_option(opt, llinfo, dev->dev_addr, 482 dev->addr_len, dev->type); 483 484 hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len, 485 IPPROTO_ICMPV6, 486 csum_partial(hdr, 487 len, 0)); 488 489 return skb; 490 } 491 492 EXPORT_SYMBOL(ndisc_build_skb); 493 494 void ndisc_send_skb(struct sk_buff *skb, 495 struct net_device *dev, 496 struct neighbour *neigh, 497 const struct in6_addr *daddr, 498 const struct in6_addr *saddr, 499 struct icmp6hdr *icmp6h) 500 { 501 struct flowi6 fl6; 502 struct dst_entry *dst; 503 struct net *net = dev_net(dev); 504 struct sock *sk = net->ipv6.ndisc_sk; 505 struct inet6_dev *idev; 506 int err; 507 u8 type; 508 509 type = icmp6h->icmp6_type; 510 511 icmpv6_flow_init(sk, &fl6, type, saddr, daddr, dev->ifindex); 512 dst = icmp6_dst_alloc(dev, neigh, &fl6); 513 if (IS_ERR(dst)) { 514 kfree_skb(skb); 515 return; 516 } 517 518 skb_dst_set(skb, dst); 519 520 rcu_read_lock(); 521 idev = __in6_dev_get(dst->dev); 522 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len); 523 524 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev, 525 dst_output); 526 if (!err) { 527 ICMP6MSGOUT_INC_STATS(net, idev, type); 528 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 529 } 530 531 rcu_read_unlock(); 532 } 533 534 EXPORT_SYMBOL(ndisc_send_skb); 535 536 /* 537 * Send a Neighbour Discover packet 538 */ 539 static void __ndisc_send(struct net_device *dev, 540 struct neighbour *neigh, 541 const struct in6_addr *daddr, 542 const struct in6_addr *saddr, 543 struct icmp6hdr *icmp6h, const struct in6_addr *target, 544 int llinfo) 545 { 546 struct sk_buff *skb; 547 548 skb = ndisc_build_skb(dev, daddr, saddr, icmp6h, target, llinfo); 549 if (!skb) 550 return; 551 552 ndisc_send_skb(skb, dev, neigh, daddr, saddr, icmp6h); 553 } 554 555 static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh, 556 const struct in6_addr *daddr, 557 const struct in6_addr *solicited_addr, 558 int router, int solicited, int override, int inc_opt) 559 { 560 struct in6_addr tmpaddr; 561 struct inet6_ifaddr *ifp; 562 const struct in6_addr *src_addr; 563 struct icmp6hdr icmp6h = { 564 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT, 565 }; 566 567 /* for anycast or proxy, solicited_addr != src_addr */ 568 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1); 569 if (ifp) { 570 src_addr = solicited_addr; 571 if (ifp->flags & IFA_F_OPTIMISTIC) 572 override = 0; 573 inc_opt |= ifp->idev->cnf.force_tllao; 574 in6_ifa_put(ifp); 575 } else { 576 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr, 577 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs, 578 &tmpaddr)) 579 return; 580 src_addr = &tmpaddr; 581 } 582 583 icmp6h.icmp6_router = router; 584 icmp6h.icmp6_solicited = solicited; 585 icmp6h.icmp6_override = override; 586 587 __ndisc_send(dev, neigh, daddr, src_addr, 588 &icmp6h, solicited_addr, 589 inc_opt ? ND_OPT_TARGET_LL_ADDR : 0); 590 } 591 592 static void ndisc_send_unsol_na(struct net_device *dev) 593 { 594 struct inet6_dev *idev; 595 struct inet6_ifaddr *ifa; 596 struct in6_addr mcaddr; 597 598 idev = in6_dev_get(dev); 599 if (!idev) 600 return; 601 602 read_lock_bh(&idev->lock); 603 list_for_each_entry(ifa, &idev->addr_list, if_list) { 604 addrconf_addr_solict_mult(&ifa->addr, &mcaddr); 605 ndisc_send_na(dev, NULL, &mcaddr, &ifa->addr, 606 /*router=*/ !!idev->cnf.forwarding, 607 /*solicited=*/ false, /*override=*/ true, 608 /*inc_opt=*/ true); 609 } 610 read_unlock_bh(&idev->lock); 611 612 in6_dev_put(idev); 613 } 614 615 void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh, 616 const struct in6_addr *solicit, 617 const struct in6_addr *daddr, const struct in6_addr *saddr) 618 { 619 struct in6_addr addr_buf; 620 struct icmp6hdr icmp6h = { 621 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION, 622 }; 623 624 if (saddr == NULL) { 625 if (ipv6_get_lladdr(dev, &addr_buf, 626 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))) 627 return; 628 saddr = &addr_buf; 629 } 630 631 __ndisc_send(dev, neigh, daddr, saddr, 632 &icmp6h, solicit, 633 !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0); 634 } 635 636 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr, 637 const struct in6_addr *daddr) 638 { 639 struct icmp6hdr icmp6h = { 640 .icmp6_type = NDISC_ROUTER_SOLICITATION, 641 }; 642 int send_sllao = dev->addr_len; 643 644 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 645 /* 646 * According to section 2.2 of RFC 4429, we must not 647 * send router solicitations with a sllao from 648 * optimistic addresses, but we may send the solicitation 649 * if we don't include the sllao. So here we check 650 * if our address is optimistic, and if so, we 651 * suppress the inclusion of the sllao. 652 */ 653 if (send_sllao) { 654 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr, 655 dev, 1); 656 if (ifp) { 657 if (ifp->flags & IFA_F_OPTIMISTIC) { 658 send_sllao = 0; 659 } 660 in6_ifa_put(ifp); 661 } else { 662 send_sllao = 0; 663 } 664 } 665 #endif 666 __ndisc_send(dev, NULL, daddr, saddr, 667 &icmp6h, NULL, 668 send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0); 669 } 670 671 672 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb) 673 { 674 /* 675 * "The sender MUST return an ICMP 676 * destination unreachable" 677 */ 678 dst_link_failure(skb); 679 kfree_skb(skb); 680 } 681 682 /* Called with locked neigh: either read or both */ 683 684 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb) 685 { 686 struct in6_addr *saddr = NULL; 687 struct in6_addr mcaddr; 688 struct net_device *dev = neigh->dev; 689 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key; 690 int probes = atomic_read(&neigh->probes); 691 692 if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1)) 693 saddr = &ipv6_hdr(skb)->saddr; 694 695 if ((probes -= neigh->parms->ucast_probes) < 0) { 696 if (!(neigh->nud_state & NUD_VALID)) { 697 ND_PRINTK1(KERN_DEBUG "%s(): trying to ucast probe in NUD_INVALID: %pI6\n", 698 __func__, target); 699 } 700 ndisc_send_ns(dev, neigh, target, target, saddr); 701 } else if ((probes -= neigh->parms->app_probes) < 0) { 702 #ifdef CONFIG_ARPD 703 neigh_app_ns(neigh); 704 #endif 705 } else { 706 addrconf_addr_solict_mult(target, &mcaddr); 707 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr); 708 } 709 } 710 711 static int pndisc_is_router(const void *pkey, 712 struct net_device *dev) 713 { 714 struct pneigh_entry *n; 715 int ret = -1; 716 717 read_lock_bh(&nd_tbl.lock); 718 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev); 719 if (n) 720 ret = !!(n->flags & NTF_ROUTER); 721 read_unlock_bh(&nd_tbl.lock); 722 723 return ret; 724 } 725 726 static void ndisc_recv_ns(struct sk_buff *skb) 727 { 728 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 729 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 730 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 731 u8 *lladdr = NULL; 732 u32 ndoptlen = skb->tail - (skb->transport_header + 733 offsetof(struct nd_msg, opt)); 734 struct ndisc_options ndopts; 735 struct net_device *dev = skb->dev; 736 struct inet6_ifaddr *ifp; 737 struct inet6_dev *idev = NULL; 738 struct neighbour *neigh; 739 int dad = ipv6_addr_any(saddr); 740 int inc; 741 int is_router = -1; 742 743 if (ipv6_addr_is_multicast(&msg->target)) { 744 ND_PRINTK2(KERN_WARNING 745 "ICMPv6 NS: multicast target address"); 746 return; 747 } 748 749 /* 750 * RFC2461 7.1.1: 751 * DAD has to be destined for solicited node multicast address. 752 */ 753 if (dad && 754 !(daddr->s6_addr32[0] == htonl(0xff020000) && 755 daddr->s6_addr32[1] == htonl(0x00000000) && 756 daddr->s6_addr32[2] == htonl(0x00000001) && 757 daddr->s6_addr [12] == 0xff )) { 758 ND_PRINTK2(KERN_WARNING 759 "ICMPv6 NS: bad DAD packet (wrong destination)\n"); 760 return; 761 } 762 763 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { 764 ND_PRINTK2(KERN_WARNING 765 "ICMPv6 NS: invalid ND options\n"); 766 return; 767 } 768 769 if (ndopts.nd_opts_src_lladdr) { 770 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev); 771 if (!lladdr) { 772 ND_PRINTK2(KERN_WARNING 773 "ICMPv6 NS: invalid link-layer address length\n"); 774 return; 775 } 776 777 /* RFC2461 7.1.1: 778 * If the IP source address is the unspecified address, 779 * there MUST NOT be source link-layer address option 780 * in the message. 781 */ 782 if (dad) { 783 ND_PRINTK2(KERN_WARNING 784 "ICMPv6 NS: bad DAD packet (link-layer address option)\n"); 785 return; 786 } 787 } 788 789 inc = ipv6_addr_is_multicast(daddr); 790 791 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); 792 if (ifp) { 793 794 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) { 795 if (dad) { 796 if (dev->type == ARPHRD_IEEE802_TR) { 797 const unsigned char *sadr; 798 sadr = skb_mac_header(skb); 799 if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 && 800 sadr[9] == dev->dev_addr[1] && 801 sadr[10] == dev->dev_addr[2] && 802 sadr[11] == dev->dev_addr[3] && 803 sadr[12] == dev->dev_addr[4] && 804 sadr[13] == dev->dev_addr[5]) { 805 /* looped-back to us */ 806 goto out; 807 } 808 } 809 810 /* 811 * We are colliding with another node 812 * who is doing DAD 813 * so fail our DAD process 814 */ 815 addrconf_dad_failure(ifp); 816 return; 817 } else { 818 /* 819 * This is not a dad solicitation. 820 * If we are an optimistic node, 821 * we should respond. 822 * Otherwise, we should ignore it. 823 */ 824 if (!(ifp->flags & IFA_F_OPTIMISTIC)) 825 goto out; 826 } 827 } 828 829 idev = ifp->idev; 830 } else { 831 struct net *net = dev_net(dev); 832 833 idev = in6_dev_get(dev); 834 if (!idev) { 835 /* XXX: count this drop? */ 836 return; 837 } 838 839 if (ipv6_chk_acast_addr(net, dev, &msg->target) || 840 (idev->cnf.forwarding && 841 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) && 842 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) { 843 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) && 844 skb->pkt_type != PACKET_HOST && 845 inc != 0 && 846 idev->nd_parms->proxy_delay != 0) { 847 /* 848 * for anycast or proxy, 849 * sender should delay its response 850 * by a random time between 0 and 851 * MAX_ANYCAST_DELAY_TIME seconds. 852 * (RFC2461) -- yoshfuji 853 */ 854 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC); 855 if (n) 856 pneigh_enqueue(&nd_tbl, idev->nd_parms, n); 857 goto out; 858 } 859 } else 860 goto out; 861 } 862 863 if (is_router < 0) 864 is_router = !!idev->cnf.forwarding; 865 866 if (dad) { 867 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target, 868 is_router, 0, (ifp != NULL), 1); 869 goto out; 870 } 871 872 if (inc) 873 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast); 874 else 875 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast); 876 877 /* 878 * update / create cache entry 879 * for the source address 880 */ 881 neigh = __neigh_lookup(&nd_tbl, saddr, dev, 882 !inc || lladdr || !dev->addr_len); 883 if (neigh) 884 neigh_update(neigh, lladdr, NUD_STALE, 885 NEIGH_UPDATE_F_WEAK_OVERRIDE| 886 NEIGH_UPDATE_F_OVERRIDE); 887 if (neigh || !dev->header_ops) { 888 ndisc_send_na(dev, neigh, saddr, &msg->target, 889 is_router, 890 1, (ifp != NULL && inc), inc); 891 if (neigh) 892 neigh_release(neigh); 893 } 894 895 out: 896 if (ifp) 897 in6_ifa_put(ifp); 898 else 899 in6_dev_put(idev); 900 } 901 902 static void ndisc_recv_na(struct sk_buff *skb) 903 { 904 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 905 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 906 const struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 907 u8 *lladdr = NULL; 908 u32 ndoptlen = skb->tail - (skb->transport_header + 909 offsetof(struct nd_msg, opt)); 910 struct ndisc_options ndopts; 911 struct net_device *dev = skb->dev; 912 struct inet6_ifaddr *ifp; 913 struct neighbour *neigh; 914 915 if (skb->len < sizeof(struct nd_msg)) { 916 ND_PRINTK2(KERN_WARNING 917 "ICMPv6 NA: packet too short\n"); 918 return; 919 } 920 921 if (ipv6_addr_is_multicast(&msg->target)) { 922 ND_PRINTK2(KERN_WARNING 923 "ICMPv6 NA: target address is multicast.\n"); 924 return; 925 } 926 927 if (ipv6_addr_is_multicast(daddr) && 928 msg->icmph.icmp6_solicited) { 929 ND_PRINTK2(KERN_WARNING 930 "ICMPv6 NA: solicited NA is multicasted.\n"); 931 return; 932 } 933 934 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { 935 ND_PRINTK2(KERN_WARNING 936 "ICMPv6 NS: invalid ND option\n"); 937 return; 938 } 939 if (ndopts.nd_opts_tgt_lladdr) { 940 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev); 941 if (!lladdr) { 942 ND_PRINTK2(KERN_WARNING 943 "ICMPv6 NA: invalid link-layer address length\n"); 944 return; 945 } 946 } 947 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); 948 if (ifp) { 949 if (skb->pkt_type != PACKET_LOOPBACK 950 && (ifp->flags & IFA_F_TENTATIVE)) { 951 addrconf_dad_failure(ifp); 952 return; 953 } 954 /* What should we make now? The advertisement 955 is invalid, but ndisc specs say nothing 956 about it. It could be misconfiguration, or 957 an smart proxy agent tries to help us :-) 958 959 We should not print the error if NA has been 960 received from loopback - it is just our own 961 unsolicited advertisement. 962 */ 963 if (skb->pkt_type != PACKET_LOOPBACK) 964 ND_PRINTK1(KERN_WARNING 965 "ICMPv6 NA: someone advertises our address %pI6 on %s!\n", 966 &ifp->addr, ifp->idev->dev->name); 967 in6_ifa_put(ifp); 968 return; 969 } 970 neigh = neigh_lookup(&nd_tbl, &msg->target, dev); 971 972 if (neigh) { 973 u8 old_flags = neigh->flags; 974 struct net *net = dev_net(dev); 975 976 if (neigh->nud_state & NUD_FAILED) 977 goto out; 978 979 /* 980 * Don't update the neighbor cache entry on a proxy NA from 981 * ourselves because either the proxied node is off link or it 982 * has already sent a NA to us. 983 */ 984 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) && 985 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp && 986 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) { 987 /* XXX: idev->cnf.prixy_ndp */ 988 goto out; 989 } 990 991 neigh_update(neigh, lladdr, 992 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE, 993 NEIGH_UPDATE_F_WEAK_OVERRIDE| 994 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)| 995 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 996 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0)); 997 998 if ((old_flags & ~neigh->flags) & NTF_ROUTER) { 999 /* 1000 * Change: router to host 1001 */ 1002 struct rt6_info *rt; 1003 rt = rt6_get_dflt_router(saddr, dev); 1004 if (rt) 1005 ip6_del_rt(rt); 1006 } 1007 1008 out: 1009 neigh_release(neigh); 1010 } 1011 } 1012 1013 static void ndisc_recv_rs(struct sk_buff *skb) 1014 { 1015 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb); 1016 unsigned long ndoptlen = skb->len - sizeof(*rs_msg); 1017 struct neighbour *neigh; 1018 struct inet6_dev *idev; 1019 const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 1020 struct ndisc_options ndopts; 1021 u8 *lladdr = NULL; 1022 1023 if (skb->len < sizeof(*rs_msg)) 1024 return; 1025 1026 idev = __in6_dev_get(skb->dev); 1027 if (!idev) { 1028 if (net_ratelimit()) 1029 ND_PRINTK1("ICMP6 RS: can't find in6 device\n"); 1030 return; 1031 } 1032 1033 /* Don't accept RS if we're not in router mode */ 1034 if (!idev->cnf.forwarding) 1035 goto out; 1036 1037 /* 1038 * Don't update NCE if src = ::; 1039 * this implies that the source node has no ip address assigned yet. 1040 */ 1041 if (ipv6_addr_any(saddr)) 1042 goto out; 1043 1044 /* Parse ND options */ 1045 if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) { 1046 if (net_ratelimit()) 1047 ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n"); 1048 goto out; 1049 } 1050 1051 if (ndopts.nd_opts_src_lladdr) { 1052 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1053 skb->dev); 1054 if (!lladdr) 1055 goto out; 1056 } 1057 1058 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1); 1059 if (neigh) { 1060 neigh_update(neigh, lladdr, NUD_STALE, 1061 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1062 NEIGH_UPDATE_F_OVERRIDE| 1063 NEIGH_UPDATE_F_OVERRIDE_ISROUTER); 1064 neigh_release(neigh); 1065 } 1066 out: 1067 return; 1068 } 1069 1070 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt) 1071 { 1072 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra); 1073 struct sk_buff *skb; 1074 struct nlmsghdr *nlh; 1075 struct nduseroptmsg *ndmsg; 1076 struct net *net = dev_net(ra->dev); 1077 int err; 1078 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg) 1079 + (opt->nd_opt_len << 3)); 1080 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr)); 1081 1082 skb = nlmsg_new(msg_size, GFP_ATOMIC); 1083 if (skb == NULL) { 1084 err = -ENOBUFS; 1085 goto errout; 1086 } 1087 1088 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0); 1089 if (nlh == NULL) { 1090 goto nla_put_failure; 1091 } 1092 1093 ndmsg = nlmsg_data(nlh); 1094 ndmsg->nduseropt_family = AF_INET6; 1095 ndmsg->nduseropt_ifindex = ra->dev->ifindex; 1096 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type; 1097 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code; 1098 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3; 1099 1100 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3); 1101 1102 NLA_PUT(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr), 1103 &ipv6_hdr(ra)->saddr); 1104 nlmsg_end(skb, nlh); 1105 1106 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC); 1107 return; 1108 1109 nla_put_failure: 1110 nlmsg_free(skb); 1111 err = -EMSGSIZE; 1112 errout: 1113 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err); 1114 } 1115 1116 static inline int accept_ra(struct inet6_dev *in6_dev) 1117 { 1118 /* 1119 * If forwarding is enabled, RA are not accepted unless the special 1120 * hybrid mode (accept_ra=2) is enabled. 1121 */ 1122 if (in6_dev->cnf.forwarding && in6_dev->cnf.accept_ra < 2) 1123 return 0; 1124 1125 return in6_dev->cnf.accept_ra; 1126 } 1127 1128 static void ndisc_router_discovery(struct sk_buff *skb) 1129 { 1130 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb); 1131 struct neighbour *neigh = NULL; 1132 struct inet6_dev *in6_dev; 1133 struct rt6_info *rt = NULL; 1134 int lifetime; 1135 struct ndisc_options ndopts; 1136 int optlen; 1137 unsigned int pref = 0; 1138 1139 __u8 * opt = (__u8 *)(ra_msg + 1); 1140 1141 optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg); 1142 1143 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1144 ND_PRINTK2(KERN_WARNING 1145 "ICMPv6 RA: source address is not link-local.\n"); 1146 return; 1147 } 1148 if (optlen < 0) { 1149 ND_PRINTK2(KERN_WARNING 1150 "ICMPv6 RA: packet too short\n"); 1151 return; 1152 } 1153 1154 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1155 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) { 1156 ND_PRINTK2(KERN_WARNING 1157 "ICMPv6 RA: from host or unauthorized router\n"); 1158 return; 1159 } 1160 #endif 1161 1162 /* 1163 * set the RA_RECV flag in the interface 1164 */ 1165 1166 in6_dev = __in6_dev_get(skb->dev); 1167 if (in6_dev == NULL) { 1168 ND_PRINTK0(KERN_ERR 1169 "ICMPv6 RA: can't find inet6 device for %s.\n", 1170 skb->dev->name); 1171 return; 1172 } 1173 1174 if (!ndisc_parse_options(opt, optlen, &ndopts)) { 1175 ND_PRINTK2(KERN_WARNING 1176 "ICMP6 RA: invalid ND options\n"); 1177 return; 1178 } 1179 1180 if (!accept_ra(in6_dev)) 1181 goto skip_linkparms; 1182 1183 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1184 /* skip link-specific parameters from interior routers */ 1185 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) 1186 goto skip_linkparms; 1187 #endif 1188 1189 if (in6_dev->if_flags & IF_RS_SENT) { 1190 /* 1191 * flag that an RA was received after an RS was sent 1192 * out on this interface. 1193 */ 1194 in6_dev->if_flags |= IF_RA_RCVD; 1195 } 1196 1197 /* 1198 * Remember the managed/otherconf flags from most recently 1199 * received RA message (RFC 2462) -- yoshfuji 1200 */ 1201 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED | 1202 IF_RA_OTHERCONF)) | 1203 (ra_msg->icmph.icmp6_addrconf_managed ? 1204 IF_RA_MANAGED : 0) | 1205 (ra_msg->icmph.icmp6_addrconf_other ? 1206 IF_RA_OTHERCONF : 0); 1207 1208 if (!in6_dev->cnf.accept_ra_defrtr) 1209 goto skip_defrtr; 1210 1211 if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0)) 1212 goto skip_defrtr; 1213 1214 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); 1215 1216 #ifdef CONFIG_IPV6_ROUTER_PREF 1217 pref = ra_msg->icmph.icmp6_router_pref; 1218 /* 10b is handled as if it were 00b (medium) */ 1219 if (pref == ICMPV6_ROUTER_PREF_INVALID || 1220 !in6_dev->cnf.accept_ra_rtr_pref) 1221 pref = ICMPV6_ROUTER_PREF_MEDIUM; 1222 #endif 1223 1224 rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev); 1225 1226 if (rt) 1227 neigh = dst_get_neighbour_noref(&rt->dst); 1228 1229 if (rt && lifetime == 0) { 1230 neigh_clone(neigh); 1231 ip6_del_rt(rt); 1232 rt = NULL; 1233 } 1234 1235 if (rt == NULL && lifetime) { 1236 ND_PRINTK3(KERN_DEBUG 1237 "ICMPv6 RA: adding default router.\n"); 1238 1239 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref); 1240 if (rt == NULL) { 1241 ND_PRINTK0(KERN_ERR 1242 "ICMPv6 RA: %s() failed to add default route.\n", 1243 __func__); 1244 return; 1245 } 1246 1247 neigh = dst_get_neighbour_noref(&rt->dst); 1248 if (neigh == NULL) { 1249 ND_PRINTK0(KERN_ERR 1250 "ICMPv6 RA: %s() got default router without neighbour.\n", 1251 __func__); 1252 dst_release(&rt->dst); 1253 return; 1254 } 1255 neigh->flags |= NTF_ROUTER; 1256 } else if (rt) { 1257 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 1258 } 1259 1260 if (rt) 1261 rt->dst.expires = jiffies + (HZ * lifetime); 1262 1263 if (ra_msg->icmph.icmp6_hop_limit) { 1264 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit; 1265 if (rt) 1266 dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 1267 ra_msg->icmph.icmp6_hop_limit); 1268 } 1269 1270 skip_defrtr: 1271 1272 /* 1273 * Update Reachable Time and Retrans Timer 1274 */ 1275 1276 if (in6_dev->nd_parms) { 1277 unsigned long rtime = ntohl(ra_msg->retrans_timer); 1278 1279 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) { 1280 rtime = (rtime*HZ)/1000; 1281 if (rtime < HZ/10) 1282 rtime = HZ/10; 1283 in6_dev->nd_parms->retrans_time = rtime; 1284 in6_dev->tstamp = jiffies; 1285 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1286 } 1287 1288 rtime = ntohl(ra_msg->reachable_time); 1289 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) { 1290 rtime = (rtime*HZ)/1000; 1291 1292 if (rtime < HZ/10) 1293 rtime = HZ/10; 1294 1295 if (rtime != in6_dev->nd_parms->base_reachable_time) { 1296 in6_dev->nd_parms->base_reachable_time = rtime; 1297 in6_dev->nd_parms->gc_staletime = 3 * rtime; 1298 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime); 1299 in6_dev->tstamp = jiffies; 1300 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1301 } 1302 } 1303 } 1304 1305 skip_linkparms: 1306 1307 /* 1308 * Process options. 1309 */ 1310 1311 if (!neigh) 1312 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr, 1313 skb->dev, 1); 1314 if (neigh) { 1315 u8 *lladdr = NULL; 1316 if (ndopts.nd_opts_src_lladdr) { 1317 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1318 skb->dev); 1319 if (!lladdr) { 1320 ND_PRINTK2(KERN_WARNING 1321 "ICMPv6 RA: invalid link-layer address length\n"); 1322 goto out; 1323 } 1324 } 1325 neigh_update(neigh, lladdr, NUD_STALE, 1326 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1327 NEIGH_UPDATE_F_OVERRIDE| 1328 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1329 NEIGH_UPDATE_F_ISROUTER); 1330 } 1331 1332 if (!accept_ra(in6_dev)) 1333 goto out; 1334 1335 #ifdef CONFIG_IPV6_ROUTE_INFO 1336 if (ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr, NULL, 0)) 1337 goto skip_routeinfo; 1338 1339 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) { 1340 struct nd_opt_hdr *p; 1341 for (p = ndopts.nd_opts_ri; 1342 p; 1343 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) { 1344 struct route_info *ri = (struct route_info *)p; 1345 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1346 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT && 1347 ri->prefix_len == 0) 1348 continue; 1349 #endif 1350 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen) 1351 continue; 1352 rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3, 1353 &ipv6_hdr(skb)->saddr); 1354 } 1355 } 1356 1357 skip_routeinfo: 1358 #endif 1359 1360 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1361 /* skip link-specific ndopts from interior routers */ 1362 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) 1363 goto out; 1364 #endif 1365 1366 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) { 1367 struct nd_opt_hdr *p; 1368 for (p = ndopts.nd_opts_pi; 1369 p; 1370 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) { 1371 addrconf_prefix_rcv(skb->dev, (u8 *)p, 1372 (p->nd_opt_len) << 3, 1373 ndopts.nd_opts_src_lladdr != NULL); 1374 } 1375 } 1376 1377 if (ndopts.nd_opts_mtu) { 1378 __be32 n; 1379 u32 mtu; 1380 1381 memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); 1382 mtu = ntohl(n); 1383 1384 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { 1385 ND_PRINTK2(KERN_WARNING 1386 "ICMPv6 RA: invalid mtu: %d\n", 1387 mtu); 1388 } else if (in6_dev->cnf.mtu6 != mtu) { 1389 in6_dev->cnf.mtu6 = mtu; 1390 1391 if (rt) 1392 dst_metric_set(&rt->dst, RTAX_MTU, mtu); 1393 1394 rt6_mtu_change(skb->dev, mtu); 1395 } 1396 } 1397 1398 if (ndopts.nd_useropts) { 1399 struct nd_opt_hdr *p; 1400 for (p = ndopts.nd_useropts; 1401 p; 1402 p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) { 1403 ndisc_ra_useropt(skb, p); 1404 } 1405 } 1406 1407 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { 1408 ND_PRINTK2(KERN_WARNING 1409 "ICMPv6 RA: invalid RA options"); 1410 } 1411 out: 1412 if (rt) 1413 dst_release(&rt->dst); 1414 else if (neigh) 1415 neigh_release(neigh); 1416 } 1417 1418 static void ndisc_redirect_rcv(struct sk_buff *skb) 1419 { 1420 struct inet6_dev *in6_dev; 1421 struct icmp6hdr *icmph; 1422 const struct in6_addr *dest; 1423 const struct in6_addr *target; /* new first hop to destination */ 1424 struct neighbour *neigh; 1425 int on_link = 0; 1426 struct ndisc_options ndopts; 1427 int optlen; 1428 u8 *lladdr = NULL; 1429 1430 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1431 switch (skb->ndisc_nodetype) { 1432 case NDISC_NODETYPE_HOST: 1433 case NDISC_NODETYPE_NODEFAULT: 1434 ND_PRINTK2(KERN_WARNING 1435 "ICMPv6 Redirect: from host or unauthorized router\n"); 1436 return; 1437 } 1438 #endif 1439 1440 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1441 ND_PRINTK2(KERN_WARNING 1442 "ICMPv6 Redirect: source address is not link-local.\n"); 1443 return; 1444 } 1445 1446 optlen = skb->tail - skb->transport_header; 1447 optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr); 1448 1449 if (optlen < 0) { 1450 ND_PRINTK2(KERN_WARNING 1451 "ICMPv6 Redirect: packet too short\n"); 1452 return; 1453 } 1454 1455 icmph = icmp6_hdr(skb); 1456 target = (const struct in6_addr *) (icmph + 1); 1457 dest = target + 1; 1458 1459 if (ipv6_addr_is_multicast(dest)) { 1460 ND_PRINTK2(KERN_WARNING 1461 "ICMPv6 Redirect: destination address is multicast.\n"); 1462 return; 1463 } 1464 1465 if (ipv6_addr_equal(dest, target)) { 1466 on_link = 1; 1467 } else if (ipv6_addr_type(target) != 1468 (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1469 ND_PRINTK2(KERN_WARNING 1470 "ICMPv6 Redirect: target address is not link-local unicast.\n"); 1471 return; 1472 } 1473 1474 in6_dev = __in6_dev_get(skb->dev); 1475 if (!in6_dev) 1476 return; 1477 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) 1478 return; 1479 1480 /* RFC2461 8.1: 1481 * The IP source address of the Redirect MUST be the same as the current 1482 * first-hop router for the specified ICMP Destination Address. 1483 */ 1484 1485 if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) { 1486 ND_PRINTK2(KERN_WARNING 1487 "ICMPv6 Redirect: invalid ND options\n"); 1488 return; 1489 } 1490 if (ndopts.nd_opts_tgt_lladdr) { 1491 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, 1492 skb->dev); 1493 if (!lladdr) { 1494 ND_PRINTK2(KERN_WARNING 1495 "ICMPv6 Redirect: invalid link-layer address length\n"); 1496 return; 1497 } 1498 } 1499 1500 neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1); 1501 if (neigh) { 1502 rt6_redirect(dest, &ipv6_hdr(skb)->daddr, 1503 &ipv6_hdr(skb)->saddr, neigh, lladdr, 1504 on_link); 1505 neigh_release(neigh); 1506 } 1507 } 1508 1509 void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh, 1510 const struct in6_addr *target) 1511 { 1512 struct net_device *dev = skb->dev; 1513 struct net *net = dev_net(dev); 1514 struct sock *sk = net->ipv6.ndisc_sk; 1515 int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr); 1516 struct sk_buff *buff; 1517 struct icmp6hdr *icmph; 1518 struct in6_addr saddr_buf; 1519 struct in6_addr *addrp; 1520 struct rt6_info *rt; 1521 struct dst_entry *dst; 1522 struct inet6_dev *idev; 1523 struct flowi6 fl6; 1524 u8 *opt; 1525 int hlen, tlen; 1526 int rd_len; 1527 int err; 1528 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL; 1529 1530 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) { 1531 ND_PRINTK2(KERN_WARNING 1532 "ICMPv6 Redirect: no link-local address on %s\n", 1533 dev->name); 1534 return; 1535 } 1536 1537 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) && 1538 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1539 ND_PRINTK2(KERN_WARNING 1540 "ICMPv6 Redirect: target address is not link-local unicast.\n"); 1541 return; 1542 } 1543 1544 icmpv6_flow_init(sk, &fl6, NDISC_REDIRECT, 1545 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex); 1546 1547 dst = ip6_route_output(net, NULL, &fl6); 1548 if (dst->error) { 1549 dst_release(dst); 1550 return; 1551 } 1552 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0); 1553 if (IS_ERR(dst)) 1554 return; 1555 1556 rt = (struct rt6_info *) dst; 1557 1558 if (rt->rt6i_flags & RTF_GATEWAY) { 1559 ND_PRINTK2(KERN_WARNING 1560 "ICMPv6 Redirect: destination is not a neighbour.\n"); 1561 goto release; 1562 } 1563 if (!rt->rt6i_peer) 1564 rt6_bind_peer(rt, 1); 1565 if (!inet_peer_xrlim_allow(rt->rt6i_peer, 1*HZ)) 1566 goto release; 1567 1568 if (dev->addr_len) { 1569 read_lock_bh(&neigh->lock); 1570 if (neigh->nud_state & NUD_VALID) { 1571 memcpy(ha_buf, neigh->ha, dev->addr_len); 1572 read_unlock_bh(&neigh->lock); 1573 ha = ha_buf; 1574 len += ndisc_opt_addr_space(dev); 1575 } else 1576 read_unlock_bh(&neigh->lock); 1577 } 1578 1579 rd_len = min_t(unsigned int, 1580 IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8); 1581 rd_len &= ~0x7; 1582 len += rd_len; 1583 1584 hlen = LL_RESERVED_SPACE(dev); 1585 tlen = dev->needed_tailroom; 1586 buff = sock_alloc_send_skb(sk, 1587 (MAX_HEADER + sizeof(struct ipv6hdr) + 1588 len + hlen + tlen), 1589 1, &err); 1590 if (buff == NULL) { 1591 ND_PRINTK0(KERN_ERR 1592 "ICMPv6 Redirect: %s() failed to allocate an skb, err=%d.\n", 1593 __func__, err); 1594 goto release; 1595 } 1596 1597 skb_reserve(buff, hlen); 1598 ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr, 1599 IPPROTO_ICMPV6, len); 1600 1601 skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data); 1602 skb_put(buff, len); 1603 icmph = icmp6_hdr(buff); 1604 1605 memset(icmph, 0, sizeof(struct icmp6hdr)); 1606 icmph->icmp6_type = NDISC_REDIRECT; 1607 1608 /* 1609 * copy target and destination addresses 1610 */ 1611 1612 addrp = (struct in6_addr *)(icmph + 1); 1613 *addrp = *target; 1614 addrp++; 1615 *addrp = ipv6_hdr(skb)->daddr; 1616 1617 opt = (u8*) (addrp + 1); 1618 1619 /* 1620 * include target_address option 1621 */ 1622 1623 if (ha) 1624 opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha, 1625 dev->addr_len, dev->type); 1626 1627 /* 1628 * build redirect option and copy skb over to the new packet. 1629 */ 1630 1631 memset(opt, 0, 8); 1632 *(opt++) = ND_OPT_REDIRECT_HDR; 1633 *(opt++) = (rd_len >> 3); 1634 opt += 6; 1635 1636 memcpy(opt, ipv6_hdr(skb), rd_len - 8); 1637 1638 icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr, 1639 len, IPPROTO_ICMPV6, 1640 csum_partial(icmph, len, 0)); 1641 1642 skb_dst_set(buff, dst); 1643 rcu_read_lock(); 1644 idev = __in6_dev_get(dst->dev); 1645 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len); 1646 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, buff, NULL, dst->dev, 1647 dst_output); 1648 if (!err) { 1649 ICMP6MSGOUT_INC_STATS(net, idev, NDISC_REDIRECT); 1650 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 1651 } 1652 1653 rcu_read_unlock(); 1654 return; 1655 1656 release: 1657 dst_release(dst); 1658 } 1659 1660 static void pndisc_redo(struct sk_buff *skb) 1661 { 1662 ndisc_recv_ns(skb); 1663 kfree_skb(skb); 1664 } 1665 1666 int ndisc_rcv(struct sk_buff *skb) 1667 { 1668 struct nd_msg *msg; 1669 1670 if (!pskb_may_pull(skb, skb->len)) 1671 return 0; 1672 1673 msg = (struct nd_msg *)skb_transport_header(skb); 1674 1675 __skb_push(skb, skb->data - skb_transport_header(skb)); 1676 1677 if (ipv6_hdr(skb)->hop_limit != 255) { 1678 ND_PRINTK2(KERN_WARNING 1679 "ICMPv6 NDISC: invalid hop-limit: %d\n", 1680 ipv6_hdr(skb)->hop_limit); 1681 return 0; 1682 } 1683 1684 if (msg->icmph.icmp6_code != 0) { 1685 ND_PRINTK2(KERN_WARNING 1686 "ICMPv6 NDISC: invalid ICMPv6 code: %d\n", 1687 msg->icmph.icmp6_code); 1688 return 0; 1689 } 1690 1691 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 1692 1693 switch (msg->icmph.icmp6_type) { 1694 case NDISC_NEIGHBOUR_SOLICITATION: 1695 ndisc_recv_ns(skb); 1696 break; 1697 1698 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1699 ndisc_recv_na(skb); 1700 break; 1701 1702 case NDISC_ROUTER_SOLICITATION: 1703 ndisc_recv_rs(skb); 1704 break; 1705 1706 case NDISC_ROUTER_ADVERTISEMENT: 1707 ndisc_router_discovery(skb); 1708 break; 1709 1710 case NDISC_REDIRECT: 1711 ndisc_redirect_rcv(skb); 1712 break; 1713 } 1714 1715 return 0; 1716 } 1717 1718 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1719 { 1720 struct net_device *dev = ptr; 1721 struct net *net = dev_net(dev); 1722 1723 switch (event) { 1724 case NETDEV_CHANGEADDR: 1725 neigh_changeaddr(&nd_tbl, dev); 1726 fib6_run_gc(~0UL, net); 1727 break; 1728 case NETDEV_DOWN: 1729 neigh_ifdown(&nd_tbl, dev); 1730 fib6_run_gc(~0UL, net); 1731 break; 1732 case NETDEV_NOTIFY_PEERS: 1733 ndisc_send_unsol_na(dev); 1734 break; 1735 default: 1736 break; 1737 } 1738 1739 return NOTIFY_DONE; 1740 } 1741 1742 static struct notifier_block ndisc_netdev_notifier = { 1743 .notifier_call = ndisc_netdev_event, 1744 }; 1745 1746 #ifdef CONFIG_SYSCTL 1747 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl, 1748 const char *func, const char *dev_name) 1749 { 1750 static char warncomm[TASK_COMM_LEN]; 1751 static int warned; 1752 if (strcmp(warncomm, current->comm) && warned < 5) { 1753 strcpy(warncomm, current->comm); 1754 printk(KERN_WARNING 1755 "process `%s' is using deprecated sysctl (%s) " 1756 "net.ipv6.neigh.%s.%s; " 1757 "Use net.ipv6.neigh.%s.%s_ms " 1758 "instead.\n", 1759 warncomm, func, 1760 dev_name, ctl->procname, 1761 dev_name, ctl->procname); 1762 warned++; 1763 } 1764 } 1765 1766 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos) 1767 { 1768 struct net_device *dev = ctl->extra1; 1769 struct inet6_dev *idev; 1770 int ret; 1771 1772 if ((strcmp(ctl->procname, "retrans_time") == 0) || 1773 (strcmp(ctl->procname, "base_reachable_time") == 0)) 1774 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default"); 1775 1776 if (strcmp(ctl->procname, "retrans_time") == 0) 1777 ret = proc_dointvec(ctl, write, buffer, lenp, ppos); 1778 1779 else if (strcmp(ctl->procname, "base_reachable_time") == 0) 1780 ret = proc_dointvec_jiffies(ctl, write, 1781 buffer, lenp, ppos); 1782 1783 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) || 1784 (strcmp(ctl->procname, "base_reachable_time_ms") == 0)) 1785 ret = proc_dointvec_ms_jiffies(ctl, write, 1786 buffer, lenp, ppos); 1787 else 1788 ret = -1; 1789 1790 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) { 1791 if (ctl->data == &idev->nd_parms->base_reachable_time) 1792 idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time); 1793 idev->tstamp = jiffies; 1794 inet6_ifinfo_notify(RTM_NEWLINK, idev); 1795 in6_dev_put(idev); 1796 } 1797 return ret; 1798 } 1799 1800 1801 #endif 1802 1803 static int __net_init ndisc_net_init(struct net *net) 1804 { 1805 struct ipv6_pinfo *np; 1806 struct sock *sk; 1807 int err; 1808 1809 err = inet_ctl_sock_create(&sk, PF_INET6, 1810 SOCK_RAW, IPPROTO_ICMPV6, net); 1811 if (err < 0) { 1812 ND_PRINTK0(KERN_ERR 1813 "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n", 1814 err); 1815 return err; 1816 } 1817 1818 net->ipv6.ndisc_sk = sk; 1819 1820 np = inet6_sk(sk); 1821 np->hop_limit = 255; 1822 /* Do not loopback ndisc messages */ 1823 np->mc_loop = 0; 1824 1825 return 0; 1826 } 1827 1828 static void __net_exit ndisc_net_exit(struct net *net) 1829 { 1830 inet_ctl_sock_destroy(net->ipv6.ndisc_sk); 1831 } 1832 1833 static struct pernet_operations ndisc_net_ops = { 1834 .init = ndisc_net_init, 1835 .exit = ndisc_net_exit, 1836 }; 1837 1838 int __init ndisc_init(void) 1839 { 1840 int err; 1841 1842 err = register_pernet_subsys(&ndisc_net_ops); 1843 if (err) 1844 return err; 1845 /* 1846 * Initialize the neighbour table 1847 */ 1848 neigh_table_init(&nd_tbl); 1849 1850 #ifdef CONFIG_SYSCTL 1851 err = neigh_sysctl_register(NULL, &nd_tbl.parms, "ipv6", 1852 &ndisc_ifinfo_sysctl_change); 1853 if (err) 1854 goto out_unregister_pernet; 1855 #endif 1856 err = register_netdevice_notifier(&ndisc_netdev_notifier); 1857 if (err) 1858 goto out_unregister_sysctl; 1859 out: 1860 return err; 1861 1862 out_unregister_sysctl: 1863 #ifdef CONFIG_SYSCTL 1864 neigh_sysctl_unregister(&nd_tbl.parms); 1865 out_unregister_pernet: 1866 #endif 1867 unregister_pernet_subsys(&ndisc_net_ops); 1868 goto out; 1869 } 1870 1871 void ndisc_cleanup(void) 1872 { 1873 unregister_netdevice_notifier(&ndisc_netdev_notifier); 1874 #ifdef CONFIG_SYSCTL 1875 neigh_sysctl_unregister(&nd_tbl.parms); 1876 #endif 1877 neigh_table_clear(&nd_tbl); 1878 unregister_pernet_subsys(&ndisc_net_ops); 1879 } 1880