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 #ifdef CONFIG_SYSCTL 63 #include <linux/sysctl.h> 64 #endif 65 66 #include <linux/if_addr.h> 67 #include <linux/if_arp.h> 68 #include <linux/ipv6.h> 69 #include <linux/icmpv6.h> 70 #include <linux/jhash.h> 71 72 #include <net/sock.h> 73 #include <net/snmp.h> 74 75 #include <net/ipv6.h> 76 #include <net/protocol.h> 77 #include <net/ndisc.h> 78 #include <net/ip6_route.h> 79 #include <net/addrconf.h> 80 #include <net/icmp.h> 81 82 #include <net/netlink.h> 83 #include <linux/rtnetlink.h> 84 85 #include <net/flow.h> 86 #include <net/ip6_checksum.h> 87 #include <net/inet_common.h> 88 #include <linux/proc_fs.h> 89 90 #include <linux/netfilter.h> 91 #include <linux/netfilter_ipv6.h> 92 93 static u32 ndisc_hash(const void *pkey, const struct net_device *dev); 94 static int ndisc_constructor(struct neighbour *neigh); 95 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb); 96 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb); 97 static int pndisc_constructor(struct pneigh_entry *n); 98 static void pndisc_destructor(struct pneigh_entry *n); 99 static void pndisc_redo(struct sk_buff *skb); 100 101 static struct neigh_ops ndisc_generic_ops = { 102 .family = AF_INET6, 103 .solicit = ndisc_solicit, 104 .error_report = ndisc_error_report, 105 .output = neigh_resolve_output, 106 .connected_output = neigh_connected_output, 107 .hh_output = dev_queue_xmit, 108 .queue_xmit = dev_queue_xmit, 109 }; 110 111 static struct neigh_ops ndisc_hh_ops = { 112 .family = AF_INET6, 113 .solicit = ndisc_solicit, 114 .error_report = ndisc_error_report, 115 .output = neigh_resolve_output, 116 .connected_output = neigh_resolve_output, 117 .hh_output = dev_queue_xmit, 118 .queue_xmit = dev_queue_xmit, 119 }; 120 121 122 static struct neigh_ops ndisc_direct_ops = { 123 .family = AF_INET6, 124 .output = dev_queue_xmit, 125 .connected_output = dev_queue_xmit, 126 .hh_output = dev_queue_xmit, 127 .queue_xmit = dev_queue_xmit, 128 }; 129 130 struct neigh_table nd_tbl = { 131 .family = AF_INET6, 132 .entry_size = sizeof(struct neighbour) + sizeof(struct in6_addr), 133 .key_len = sizeof(struct in6_addr), 134 .hash = ndisc_hash, 135 .constructor = ndisc_constructor, 136 .pconstructor = pndisc_constructor, 137 .pdestructor = pndisc_destructor, 138 .proxy_redo = pndisc_redo, 139 .id = "ndisc_cache", 140 .parms = { 141 .tbl = &nd_tbl, 142 .base_reachable_time = 30 * HZ, 143 .retrans_time = 1 * HZ, 144 .gc_staletime = 60 * HZ, 145 .reachable_time = 30 * HZ, 146 .delay_probe_time = 5 * HZ, 147 .queue_len = 3, 148 .ucast_probes = 3, 149 .mcast_probes = 3, 150 .anycast_delay = 1 * HZ, 151 .proxy_delay = (8 * HZ) / 10, 152 .proxy_qlen = 64, 153 }, 154 .gc_interval = 30 * HZ, 155 .gc_thresh1 = 128, 156 .gc_thresh2 = 512, 157 .gc_thresh3 = 1024, 158 }; 159 160 /* ND options */ 161 struct ndisc_options { 162 struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX]; 163 #ifdef CONFIG_IPV6_ROUTE_INFO 164 struct nd_opt_hdr *nd_opts_ri; 165 struct nd_opt_hdr *nd_opts_ri_end; 166 #endif 167 struct nd_opt_hdr *nd_useropts; 168 struct nd_opt_hdr *nd_useropts_end; 169 }; 170 171 #define nd_opts_src_lladdr nd_opt_array[ND_OPT_SOURCE_LL_ADDR] 172 #define nd_opts_tgt_lladdr nd_opt_array[ND_OPT_TARGET_LL_ADDR] 173 #define nd_opts_pi nd_opt_array[ND_OPT_PREFIX_INFO] 174 #define nd_opts_pi_end nd_opt_array[__ND_OPT_PREFIX_INFO_END] 175 #define nd_opts_rh nd_opt_array[ND_OPT_REDIRECT_HDR] 176 #define nd_opts_mtu nd_opt_array[ND_OPT_MTU] 177 178 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7) 179 180 /* 181 * Return the padding between the option length and the start of the 182 * link addr. Currently only IP-over-InfiniBand needs this, although 183 * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may 184 * also need a pad of 2. 185 */ 186 static int ndisc_addr_option_pad(unsigned short type) 187 { 188 switch (type) { 189 case ARPHRD_INFINIBAND: return 2; 190 default: return 0; 191 } 192 } 193 194 static inline int ndisc_opt_addr_space(struct net_device *dev) 195 { 196 return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type)); 197 } 198 199 static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len, 200 unsigned short addr_type) 201 { 202 int space = NDISC_OPT_SPACE(data_len); 203 int pad = ndisc_addr_option_pad(addr_type); 204 205 opt[0] = type; 206 opt[1] = space>>3; 207 208 memset(opt + 2, 0, pad); 209 opt += pad; 210 space -= pad; 211 212 memcpy(opt+2, data, data_len); 213 data_len += 2; 214 opt += data_len; 215 if ((space -= data_len) > 0) 216 memset(opt, 0, space); 217 return opt + space; 218 } 219 220 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur, 221 struct nd_opt_hdr *end) 222 { 223 int type; 224 if (!cur || !end || cur >= end) 225 return NULL; 226 type = cur->nd_opt_type; 227 do { 228 cur = ((void *)cur) + (cur->nd_opt_len << 3); 229 } while(cur < end && cur->nd_opt_type != type); 230 return (cur <= end && cur->nd_opt_type == type ? cur : NULL); 231 } 232 233 static inline int ndisc_is_useropt(struct nd_opt_hdr *opt) 234 { 235 return (opt->nd_opt_type == ND_OPT_RDNSS); 236 } 237 238 static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur, 239 struct nd_opt_hdr *end) 240 { 241 if (!cur || !end || cur >= end) 242 return NULL; 243 do { 244 cur = ((void *)cur) + (cur->nd_opt_len << 3); 245 } while(cur < end && !ndisc_is_useropt(cur)); 246 return (cur <= end && ndisc_is_useropt(cur) ? cur : NULL); 247 } 248 249 static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len, 250 struct ndisc_options *ndopts) 251 { 252 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt; 253 254 if (!nd_opt || opt_len < 0 || !ndopts) 255 return NULL; 256 memset(ndopts, 0, sizeof(*ndopts)); 257 while (opt_len) { 258 int l; 259 if (opt_len < sizeof(struct nd_opt_hdr)) 260 return NULL; 261 l = nd_opt->nd_opt_len << 3; 262 if (opt_len < l || l == 0) 263 return NULL; 264 switch (nd_opt->nd_opt_type) { 265 case ND_OPT_SOURCE_LL_ADDR: 266 case ND_OPT_TARGET_LL_ADDR: 267 case ND_OPT_MTU: 268 case ND_OPT_REDIRECT_HDR: 269 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { 270 ND_PRINTK2(KERN_WARNING 271 "%s(): duplicated ND6 option found: type=%d\n", 272 __func__, 273 nd_opt->nd_opt_type); 274 } else { 275 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; 276 } 277 break; 278 case ND_OPT_PREFIX_INFO: 279 ndopts->nd_opts_pi_end = nd_opt; 280 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type]) 281 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; 282 break; 283 #ifdef CONFIG_IPV6_ROUTE_INFO 284 case ND_OPT_ROUTE_INFO: 285 ndopts->nd_opts_ri_end = nd_opt; 286 if (!ndopts->nd_opts_ri) 287 ndopts->nd_opts_ri = nd_opt; 288 break; 289 #endif 290 default: 291 if (ndisc_is_useropt(nd_opt)) { 292 ndopts->nd_useropts_end = nd_opt; 293 if (!ndopts->nd_useropts) 294 ndopts->nd_useropts = nd_opt; 295 } else { 296 /* 297 * Unknown options must be silently ignored, 298 * to accommodate future extension to the 299 * protocol. 300 */ 301 ND_PRINTK2(KERN_NOTICE 302 "%s(): ignored unsupported option; type=%d, len=%d\n", 303 __func__, 304 nd_opt->nd_opt_type, nd_opt->nd_opt_len); 305 } 306 } 307 opt_len -= l; 308 nd_opt = ((void *)nd_opt) + l; 309 } 310 return ndopts; 311 } 312 313 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p, 314 struct net_device *dev) 315 { 316 u8 *lladdr = (u8 *)(p + 1); 317 int lladdrlen = p->nd_opt_len << 3; 318 int prepad = ndisc_addr_option_pad(dev->type); 319 if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad)) 320 return NULL; 321 return (lladdr + prepad); 322 } 323 324 int ndisc_mc_map(struct in6_addr *addr, char *buf, struct net_device *dev, int dir) 325 { 326 switch (dev->type) { 327 case ARPHRD_ETHER: 328 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */ 329 case ARPHRD_FDDI: 330 ipv6_eth_mc_map(addr, buf); 331 return 0; 332 case ARPHRD_IEEE802_TR: 333 ipv6_tr_mc_map(addr,buf); 334 return 0; 335 case ARPHRD_ARCNET: 336 ipv6_arcnet_mc_map(addr, buf); 337 return 0; 338 case ARPHRD_INFINIBAND: 339 ipv6_ib_mc_map(addr, dev->broadcast, buf); 340 return 0; 341 default: 342 if (dir) { 343 memcpy(buf, dev->broadcast, dev->addr_len); 344 return 0; 345 } 346 } 347 return -EINVAL; 348 } 349 350 EXPORT_SYMBOL(ndisc_mc_map); 351 352 static u32 ndisc_hash(const void *pkey, const struct net_device *dev) 353 { 354 const u32 *p32 = pkey; 355 u32 addr_hash, i; 356 357 addr_hash = 0; 358 for (i = 0; i < (sizeof(struct in6_addr) / sizeof(u32)); i++) 359 addr_hash ^= *p32++; 360 361 return jhash_2words(addr_hash, dev->ifindex, nd_tbl.hash_rnd); 362 } 363 364 static int ndisc_constructor(struct neighbour *neigh) 365 { 366 struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key; 367 struct net_device *dev = neigh->dev; 368 struct inet6_dev *in6_dev; 369 struct neigh_parms *parms; 370 int is_multicast = ipv6_addr_is_multicast(addr); 371 372 rcu_read_lock(); 373 in6_dev = in6_dev_get(dev); 374 if (in6_dev == NULL) { 375 rcu_read_unlock(); 376 return -EINVAL; 377 } 378 379 parms = in6_dev->nd_parms; 380 __neigh_parms_put(neigh->parms); 381 neigh->parms = neigh_parms_clone(parms); 382 rcu_read_unlock(); 383 384 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST; 385 if (!dev->header_ops) { 386 neigh->nud_state = NUD_NOARP; 387 neigh->ops = &ndisc_direct_ops; 388 neigh->output = neigh->ops->queue_xmit; 389 } else { 390 if (is_multicast) { 391 neigh->nud_state = NUD_NOARP; 392 ndisc_mc_map(addr, neigh->ha, dev, 1); 393 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { 394 neigh->nud_state = NUD_NOARP; 395 memcpy(neigh->ha, dev->dev_addr, dev->addr_len); 396 if (dev->flags&IFF_LOOPBACK) 397 neigh->type = RTN_LOCAL; 398 } else if (dev->flags&IFF_POINTOPOINT) { 399 neigh->nud_state = NUD_NOARP; 400 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 401 } 402 if (dev->header_ops->cache) 403 neigh->ops = &ndisc_hh_ops; 404 else 405 neigh->ops = &ndisc_generic_ops; 406 if (neigh->nud_state&NUD_VALID) 407 neigh->output = neigh->ops->connected_output; 408 else 409 neigh->output = neigh->ops->output; 410 } 411 in6_dev_put(in6_dev); 412 return 0; 413 } 414 415 static int pndisc_constructor(struct pneigh_entry *n) 416 { 417 struct in6_addr *addr = (struct in6_addr*)&n->key; 418 struct in6_addr maddr; 419 struct net_device *dev = n->dev; 420 421 if (dev == NULL || __in6_dev_get(dev) == NULL) 422 return -EINVAL; 423 addrconf_addr_solict_mult(addr, &maddr); 424 ipv6_dev_mc_inc(dev, &maddr); 425 return 0; 426 } 427 428 static void pndisc_destructor(struct pneigh_entry *n) 429 { 430 struct in6_addr *addr = (struct in6_addr*)&n->key; 431 struct in6_addr maddr; 432 struct net_device *dev = n->dev; 433 434 if (dev == NULL || __in6_dev_get(dev) == NULL) 435 return; 436 addrconf_addr_solict_mult(addr, &maddr); 437 ipv6_dev_mc_dec(dev, &maddr); 438 } 439 440 /* 441 * Send a Neighbour Advertisement 442 */ 443 static void __ndisc_send(struct net_device *dev, 444 struct neighbour *neigh, 445 const struct in6_addr *daddr, 446 const struct in6_addr *saddr, 447 struct icmp6hdr *icmp6h, const struct in6_addr *target, 448 int llinfo) 449 { 450 struct flowi fl; 451 struct dst_entry *dst; 452 struct net *net = dev_net(dev); 453 struct sock *sk = net->ipv6.ndisc_sk; 454 struct sk_buff *skb; 455 struct icmp6hdr *hdr; 456 struct inet6_dev *idev; 457 int len; 458 int err; 459 u8 *opt, type; 460 461 type = icmp6h->icmp6_type; 462 463 icmpv6_flow_init(sk, &fl, type, saddr, daddr, dev->ifindex); 464 465 dst = icmp6_dst_alloc(dev, neigh, daddr); 466 if (!dst) 467 return; 468 469 err = xfrm_lookup(&dst, &fl, NULL, 0); 470 if (err < 0) 471 return; 472 473 if (!dev->addr_len) 474 llinfo = 0; 475 476 len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0); 477 if (llinfo) 478 len += ndisc_opt_addr_space(dev); 479 480 skb = sock_alloc_send_skb(sk, 481 (MAX_HEADER + sizeof(struct ipv6hdr) + 482 len + LL_ALLOCATED_SPACE(dev)), 483 1, &err); 484 if (!skb) { 485 ND_PRINTK0(KERN_ERR 486 "ICMPv6 ND: %s() failed to allocate an skb.\n", 487 __func__); 488 dst_release(dst); 489 return; 490 } 491 492 skb_reserve(skb, LL_RESERVED_SPACE(dev)); 493 ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len); 494 495 skb->transport_header = skb->tail; 496 skb_put(skb, len); 497 498 hdr = (struct icmp6hdr *)skb_transport_header(skb); 499 memcpy(hdr, icmp6h, sizeof(*hdr)); 500 501 opt = skb_transport_header(skb) + sizeof(struct icmp6hdr); 502 if (target) { 503 ipv6_addr_copy((struct in6_addr *)opt, target); 504 opt += sizeof(*target); 505 } 506 507 if (llinfo) 508 ndisc_fill_addr_option(opt, llinfo, dev->dev_addr, 509 dev->addr_len, dev->type); 510 511 hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len, 512 IPPROTO_ICMPV6, 513 csum_partial((__u8 *) hdr, 514 len, 0)); 515 516 skb->dst = dst; 517 518 idev = in6_dev_get(dst->dev); 519 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS); 520 521 err = NF_HOOK(PF_INET6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev, 522 dst_output); 523 if (!err) { 524 ICMP6MSGOUT_INC_STATS(net, idev, type); 525 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 526 } 527 528 if (likely(idev != NULL)) 529 in6_dev_put(idev); 530 } 531 532 static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh, 533 const struct in6_addr *daddr, 534 const struct in6_addr *solicited_addr, 535 int router, int solicited, int override, int inc_opt) 536 { 537 struct in6_addr tmpaddr; 538 struct inet6_ifaddr *ifp; 539 const struct in6_addr *src_addr; 540 struct icmp6hdr icmp6h = { 541 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT, 542 }; 543 544 /* for anycast or proxy, solicited_addr != src_addr */ 545 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1); 546 if (ifp) { 547 src_addr = solicited_addr; 548 if (ifp->flags & IFA_F_OPTIMISTIC) 549 override = 0; 550 in6_ifa_put(ifp); 551 } else { 552 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr, 553 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs, 554 &tmpaddr)) 555 return; 556 src_addr = &tmpaddr; 557 } 558 559 icmp6h.icmp6_router = router; 560 icmp6h.icmp6_solicited = solicited; 561 icmp6h.icmp6_override = override; 562 563 __ndisc_send(dev, neigh, daddr, src_addr, 564 &icmp6h, solicited_addr, 565 inc_opt ? ND_OPT_TARGET_LL_ADDR : 0); 566 } 567 568 void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh, 569 const struct in6_addr *solicit, 570 const struct in6_addr *daddr, const struct in6_addr *saddr) 571 { 572 struct in6_addr addr_buf; 573 struct icmp6hdr icmp6h = { 574 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION, 575 }; 576 577 if (saddr == NULL) { 578 if (ipv6_get_lladdr(dev, &addr_buf, 579 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))) 580 return; 581 saddr = &addr_buf; 582 } 583 584 __ndisc_send(dev, neigh, daddr, saddr, 585 &icmp6h, solicit, 586 !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0); 587 } 588 589 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr, 590 const struct in6_addr *daddr) 591 { 592 struct icmp6hdr icmp6h = { 593 .icmp6_type = NDISC_ROUTER_SOLICITATION, 594 }; 595 int send_sllao = dev->addr_len; 596 597 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 598 /* 599 * According to section 2.2 of RFC 4429, we must not 600 * send router solicitations with a sllao from 601 * optimistic addresses, but we may send the solicitation 602 * if we don't include the sllao. So here we check 603 * if our address is optimistic, and if so, we 604 * suppress the inclusion of the sllao. 605 */ 606 if (send_sllao) { 607 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr, 608 dev, 1); 609 if (ifp) { 610 if (ifp->flags & IFA_F_OPTIMISTIC) { 611 send_sllao = 0; 612 } 613 in6_ifa_put(ifp); 614 } else { 615 send_sllao = 0; 616 } 617 } 618 #endif 619 __ndisc_send(dev, NULL, daddr, saddr, 620 &icmp6h, NULL, 621 send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0); 622 } 623 624 625 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb) 626 { 627 /* 628 * "The sender MUST return an ICMP 629 * destination unreachable" 630 */ 631 dst_link_failure(skb); 632 kfree_skb(skb); 633 } 634 635 /* Called with locked neigh: either read or both */ 636 637 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb) 638 { 639 struct in6_addr *saddr = NULL; 640 struct in6_addr mcaddr; 641 struct net_device *dev = neigh->dev; 642 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key; 643 int probes = atomic_read(&neigh->probes); 644 645 if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1)) 646 saddr = &ipv6_hdr(skb)->saddr; 647 648 if ((probes -= neigh->parms->ucast_probes) < 0) { 649 if (!(neigh->nud_state & NUD_VALID)) { 650 ND_PRINTK1(KERN_DEBUG 651 "%s(): trying to ucast probe in NUD_INVALID: " 652 NIP6_FMT "\n", 653 __func__, 654 NIP6(*target)); 655 } 656 ndisc_send_ns(dev, neigh, target, target, saddr); 657 } else if ((probes -= neigh->parms->app_probes) < 0) { 658 #ifdef CONFIG_ARPD 659 neigh_app_ns(neigh); 660 #endif 661 } else { 662 addrconf_addr_solict_mult(target, &mcaddr); 663 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr); 664 } 665 } 666 667 static int pndisc_is_router(const void *pkey, 668 struct net_device *dev) 669 { 670 struct pneigh_entry *n; 671 int ret = -1; 672 673 read_lock_bh(&nd_tbl.lock); 674 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev); 675 if (n) 676 ret = !!(n->flags & NTF_ROUTER); 677 read_unlock_bh(&nd_tbl.lock); 678 679 return ret; 680 } 681 682 static void ndisc_recv_ns(struct sk_buff *skb) 683 { 684 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 685 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 686 struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 687 u8 *lladdr = NULL; 688 u32 ndoptlen = skb->tail - (skb->transport_header + 689 offsetof(struct nd_msg, opt)); 690 struct ndisc_options ndopts; 691 struct net_device *dev = skb->dev; 692 struct inet6_ifaddr *ifp; 693 struct inet6_dev *idev = NULL; 694 struct neighbour *neigh; 695 int dad = ipv6_addr_any(saddr); 696 int inc; 697 int is_router = -1; 698 699 if (ipv6_addr_is_multicast(&msg->target)) { 700 ND_PRINTK2(KERN_WARNING 701 "ICMPv6 NS: multicast target address"); 702 return; 703 } 704 705 /* 706 * RFC2461 7.1.1: 707 * DAD has to be destined for solicited node multicast address. 708 */ 709 if (dad && 710 !(daddr->s6_addr32[0] == htonl(0xff020000) && 711 daddr->s6_addr32[1] == htonl(0x00000000) && 712 daddr->s6_addr32[2] == htonl(0x00000001) && 713 daddr->s6_addr [12] == 0xff )) { 714 ND_PRINTK2(KERN_WARNING 715 "ICMPv6 NS: bad DAD packet (wrong destination)\n"); 716 return; 717 } 718 719 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { 720 ND_PRINTK2(KERN_WARNING 721 "ICMPv6 NS: invalid ND options\n"); 722 return; 723 } 724 725 if (ndopts.nd_opts_src_lladdr) { 726 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev); 727 if (!lladdr) { 728 ND_PRINTK2(KERN_WARNING 729 "ICMPv6 NS: invalid link-layer address length\n"); 730 return; 731 } 732 733 /* RFC2461 7.1.1: 734 * If the IP source address is the unspecified address, 735 * there MUST NOT be source link-layer address option 736 * in the message. 737 */ 738 if (dad) { 739 ND_PRINTK2(KERN_WARNING 740 "ICMPv6 NS: bad DAD packet (link-layer address option)\n"); 741 return; 742 } 743 } 744 745 inc = ipv6_addr_is_multicast(daddr); 746 747 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); 748 if (ifp) { 749 750 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) { 751 if (dad) { 752 if (dev->type == ARPHRD_IEEE802_TR) { 753 const unsigned char *sadr; 754 sadr = skb_mac_header(skb); 755 if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 && 756 sadr[9] == dev->dev_addr[1] && 757 sadr[10] == dev->dev_addr[2] && 758 sadr[11] == dev->dev_addr[3] && 759 sadr[12] == dev->dev_addr[4] && 760 sadr[13] == dev->dev_addr[5]) { 761 /* looped-back to us */ 762 goto out; 763 } 764 } 765 766 /* 767 * We are colliding with another node 768 * who is doing DAD 769 * so fail our DAD process 770 */ 771 addrconf_dad_failure(ifp); 772 return; 773 } else { 774 /* 775 * This is not a dad solicitation. 776 * If we are an optimistic node, 777 * we should respond. 778 * Otherwise, we should ignore it. 779 */ 780 if (!(ifp->flags & IFA_F_OPTIMISTIC)) 781 goto out; 782 } 783 } 784 785 idev = ifp->idev; 786 } else { 787 struct net *net = dev_net(dev); 788 789 idev = in6_dev_get(dev); 790 if (!idev) { 791 /* XXX: count this drop? */ 792 return; 793 } 794 795 if (ipv6_chk_acast_addr(net, dev, &msg->target) || 796 (idev->cnf.forwarding && 797 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) && 798 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) { 799 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) && 800 skb->pkt_type != PACKET_HOST && 801 inc != 0 && 802 idev->nd_parms->proxy_delay != 0) { 803 /* 804 * for anycast or proxy, 805 * sender should delay its response 806 * by a random time between 0 and 807 * MAX_ANYCAST_DELAY_TIME seconds. 808 * (RFC2461) -- yoshfuji 809 */ 810 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC); 811 if (n) 812 pneigh_enqueue(&nd_tbl, idev->nd_parms, n); 813 goto out; 814 } 815 } else 816 goto out; 817 } 818 819 if (is_router < 0) 820 is_router = !!idev->cnf.forwarding; 821 822 if (dad) { 823 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target, 824 is_router, 0, (ifp != NULL), 1); 825 goto out; 826 } 827 828 if (inc) 829 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast); 830 else 831 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast); 832 833 /* 834 * update / create cache entry 835 * for the source address 836 */ 837 neigh = __neigh_lookup(&nd_tbl, saddr, dev, 838 !inc || lladdr || !dev->addr_len); 839 if (neigh) 840 neigh_update(neigh, lladdr, NUD_STALE, 841 NEIGH_UPDATE_F_WEAK_OVERRIDE| 842 NEIGH_UPDATE_F_OVERRIDE); 843 if (neigh || !dev->header_ops) { 844 ndisc_send_na(dev, neigh, saddr, &msg->target, 845 is_router, 846 1, (ifp != NULL && inc), inc); 847 if (neigh) 848 neigh_release(neigh); 849 } 850 851 out: 852 if (ifp) 853 in6_ifa_put(ifp); 854 else 855 in6_dev_put(idev); 856 857 return; 858 } 859 860 static void ndisc_recv_na(struct sk_buff *skb) 861 { 862 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 863 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 864 struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 865 u8 *lladdr = NULL; 866 u32 ndoptlen = skb->tail - (skb->transport_header + 867 offsetof(struct nd_msg, opt)); 868 struct ndisc_options ndopts; 869 struct net_device *dev = skb->dev; 870 struct inet6_ifaddr *ifp; 871 struct neighbour *neigh; 872 873 if (skb->len < sizeof(struct nd_msg)) { 874 ND_PRINTK2(KERN_WARNING 875 "ICMPv6 NA: packet too short\n"); 876 return; 877 } 878 879 if (ipv6_addr_is_multicast(&msg->target)) { 880 ND_PRINTK2(KERN_WARNING 881 "ICMPv6 NA: target address is multicast.\n"); 882 return; 883 } 884 885 if (ipv6_addr_is_multicast(daddr) && 886 msg->icmph.icmp6_solicited) { 887 ND_PRINTK2(KERN_WARNING 888 "ICMPv6 NA: solicited NA is multicasted.\n"); 889 return; 890 } 891 892 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { 893 ND_PRINTK2(KERN_WARNING 894 "ICMPv6 NS: invalid ND option\n"); 895 return; 896 } 897 if (ndopts.nd_opts_tgt_lladdr) { 898 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev); 899 if (!lladdr) { 900 ND_PRINTK2(KERN_WARNING 901 "ICMPv6 NA: invalid link-layer address length\n"); 902 return; 903 } 904 } 905 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); 906 if (ifp) { 907 if (ifp->flags & IFA_F_TENTATIVE) { 908 addrconf_dad_failure(ifp); 909 return; 910 } 911 /* What should we make now? The advertisement 912 is invalid, but ndisc specs say nothing 913 about it. It could be misconfiguration, or 914 an smart proxy agent tries to help us :-) 915 */ 916 ND_PRINTK1(KERN_WARNING 917 "ICMPv6 NA: someone advertises our address on %s!\n", 918 ifp->idev->dev->name); 919 in6_ifa_put(ifp); 920 return; 921 } 922 neigh = neigh_lookup(&nd_tbl, &msg->target, dev); 923 924 if (neigh) { 925 u8 old_flags = neigh->flags; 926 struct net *net = dev_net(dev); 927 928 if (neigh->nud_state & NUD_FAILED) 929 goto out; 930 931 /* 932 * Don't update the neighbor cache entry on a proxy NA from 933 * ourselves because either the proxied node is off link or it 934 * has already sent a NA to us. 935 */ 936 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) && 937 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp && 938 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) { 939 /* XXX: idev->cnf.prixy_ndp */ 940 goto out; 941 } 942 943 neigh_update(neigh, lladdr, 944 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE, 945 NEIGH_UPDATE_F_WEAK_OVERRIDE| 946 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)| 947 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 948 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0)); 949 950 if ((old_flags & ~neigh->flags) & NTF_ROUTER) { 951 /* 952 * Change: router to host 953 */ 954 struct rt6_info *rt; 955 rt = rt6_get_dflt_router(saddr, dev); 956 if (rt) 957 ip6_del_rt(rt); 958 } 959 960 out: 961 neigh_release(neigh); 962 } 963 } 964 965 static void ndisc_recv_rs(struct sk_buff *skb) 966 { 967 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb); 968 unsigned long ndoptlen = skb->len - sizeof(*rs_msg); 969 struct neighbour *neigh; 970 struct inet6_dev *idev; 971 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 972 struct ndisc_options ndopts; 973 u8 *lladdr = NULL; 974 975 if (skb->len < sizeof(*rs_msg)) 976 return; 977 978 idev = in6_dev_get(skb->dev); 979 if (!idev) { 980 if (net_ratelimit()) 981 ND_PRINTK1("ICMP6 RS: can't find in6 device\n"); 982 return; 983 } 984 985 /* Don't accept RS if we're not in router mode */ 986 if (!idev->cnf.forwarding) 987 goto out; 988 989 /* 990 * Don't update NCE if src = ::; 991 * this implies that the source node has no ip address assigned yet. 992 */ 993 if (ipv6_addr_any(saddr)) 994 goto out; 995 996 /* Parse ND options */ 997 if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) { 998 if (net_ratelimit()) 999 ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n"); 1000 goto out; 1001 } 1002 1003 if (ndopts.nd_opts_src_lladdr) { 1004 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1005 skb->dev); 1006 if (!lladdr) 1007 goto out; 1008 } 1009 1010 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1); 1011 if (neigh) { 1012 neigh_update(neigh, lladdr, NUD_STALE, 1013 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1014 NEIGH_UPDATE_F_OVERRIDE| 1015 NEIGH_UPDATE_F_OVERRIDE_ISROUTER); 1016 neigh_release(neigh); 1017 } 1018 out: 1019 in6_dev_put(idev); 1020 } 1021 1022 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt) 1023 { 1024 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra); 1025 struct sk_buff *skb; 1026 struct nlmsghdr *nlh; 1027 struct nduseroptmsg *ndmsg; 1028 struct net *net = dev_net(ra->dev); 1029 int err; 1030 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg) 1031 + (opt->nd_opt_len << 3)); 1032 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr)); 1033 1034 skb = nlmsg_new(msg_size, GFP_ATOMIC); 1035 if (skb == NULL) { 1036 err = -ENOBUFS; 1037 goto errout; 1038 } 1039 1040 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0); 1041 if (nlh == NULL) { 1042 goto nla_put_failure; 1043 } 1044 1045 ndmsg = nlmsg_data(nlh); 1046 ndmsg->nduseropt_family = AF_INET6; 1047 ndmsg->nduseropt_ifindex = ra->dev->ifindex; 1048 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type; 1049 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code; 1050 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3; 1051 1052 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3); 1053 1054 NLA_PUT(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr), 1055 &ipv6_hdr(ra)->saddr); 1056 nlmsg_end(skb, nlh); 1057 1058 err = rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, 1059 GFP_ATOMIC); 1060 if (err < 0) 1061 goto errout; 1062 1063 return; 1064 1065 nla_put_failure: 1066 nlmsg_free(skb); 1067 err = -EMSGSIZE; 1068 errout: 1069 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err); 1070 } 1071 1072 static void ndisc_router_discovery(struct sk_buff *skb) 1073 { 1074 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb); 1075 struct neighbour *neigh = NULL; 1076 struct inet6_dev *in6_dev; 1077 struct rt6_info *rt = NULL; 1078 int lifetime; 1079 struct ndisc_options ndopts; 1080 int optlen; 1081 unsigned int pref = 0; 1082 1083 __u8 * opt = (__u8 *)(ra_msg + 1); 1084 1085 optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg); 1086 1087 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1088 ND_PRINTK2(KERN_WARNING 1089 "ICMPv6 RA: source address is not link-local.\n"); 1090 return; 1091 } 1092 if (optlen < 0) { 1093 ND_PRINTK2(KERN_WARNING 1094 "ICMPv6 RA: packet too short\n"); 1095 return; 1096 } 1097 1098 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1099 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) { 1100 ND_PRINTK2(KERN_WARNING 1101 "ICMPv6 RA: from host or unauthorized router\n"); 1102 return; 1103 } 1104 #endif 1105 1106 /* 1107 * set the RA_RECV flag in the interface 1108 */ 1109 1110 in6_dev = in6_dev_get(skb->dev); 1111 if (in6_dev == NULL) { 1112 ND_PRINTK0(KERN_ERR 1113 "ICMPv6 RA: can't find inet6 device for %s.\n", 1114 skb->dev->name); 1115 return; 1116 } 1117 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra) { 1118 in6_dev_put(in6_dev); 1119 return; 1120 } 1121 1122 if (!ndisc_parse_options(opt, optlen, &ndopts)) { 1123 in6_dev_put(in6_dev); 1124 ND_PRINTK2(KERN_WARNING 1125 "ICMP6 RA: invalid ND options\n"); 1126 return; 1127 } 1128 1129 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1130 /* skip link-specific parameters from interior routers */ 1131 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) 1132 goto skip_linkparms; 1133 #endif 1134 1135 if (in6_dev->if_flags & IF_RS_SENT) { 1136 /* 1137 * flag that an RA was received after an RS was sent 1138 * out on this interface. 1139 */ 1140 in6_dev->if_flags |= IF_RA_RCVD; 1141 } 1142 1143 /* 1144 * Remember the managed/otherconf flags from most recently 1145 * received RA message (RFC 2462) -- yoshfuji 1146 */ 1147 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED | 1148 IF_RA_OTHERCONF)) | 1149 (ra_msg->icmph.icmp6_addrconf_managed ? 1150 IF_RA_MANAGED : 0) | 1151 (ra_msg->icmph.icmp6_addrconf_other ? 1152 IF_RA_OTHERCONF : 0); 1153 1154 if (!in6_dev->cnf.accept_ra_defrtr) 1155 goto skip_defrtr; 1156 1157 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); 1158 1159 #ifdef CONFIG_IPV6_ROUTER_PREF 1160 pref = ra_msg->icmph.icmp6_router_pref; 1161 /* 10b is handled as if it were 00b (medium) */ 1162 if (pref == ICMPV6_ROUTER_PREF_INVALID || 1163 !in6_dev->cnf.accept_ra_rtr_pref) 1164 pref = ICMPV6_ROUTER_PREF_MEDIUM; 1165 #endif 1166 1167 rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev); 1168 1169 if (rt) 1170 neigh = rt->rt6i_nexthop; 1171 1172 if (rt && lifetime == 0) { 1173 neigh_clone(neigh); 1174 ip6_del_rt(rt); 1175 rt = NULL; 1176 } 1177 1178 if (rt == NULL && lifetime) { 1179 ND_PRINTK3(KERN_DEBUG 1180 "ICMPv6 RA: adding default router.\n"); 1181 1182 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref); 1183 if (rt == NULL) { 1184 ND_PRINTK0(KERN_ERR 1185 "ICMPv6 RA: %s() failed to add default route.\n", 1186 __func__); 1187 in6_dev_put(in6_dev); 1188 return; 1189 } 1190 1191 neigh = rt->rt6i_nexthop; 1192 if (neigh == NULL) { 1193 ND_PRINTK0(KERN_ERR 1194 "ICMPv6 RA: %s() got default router without neighbour.\n", 1195 __func__); 1196 dst_release(&rt->u.dst); 1197 in6_dev_put(in6_dev); 1198 return; 1199 } 1200 neigh->flags |= NTF_ROUTER; 1201 } else if (rt) { 1202 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 1203 } 1204 1205 if (rt) 1206 rt->rt6i_expires = jiffies + (HZ * lifetime); 1207 1208 if (ra_msg->icmph.icmp6_hop_limit) { 1209 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit; 1210 if (rt) 1211 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = ra_msg->icmph.icmp6_hop_limit; 1212 } 1213 1214 skip_defrtr: 1215 1216 /* 1217 * Update Reachable Time and Retrans Timer 1218 */ 1219 1220 if (in6_dev->nd_parms) { 1221 unsigned long rtime = ntohl(ra_msg->retrans_timer); 1222 1223 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) { 1224 rtime = (rtime*HZ)/1000; 1225 if (rtime < HZ/10) 1226 rtime = HZ/10; 1227 in6_dev->nd_parms->retrans_time = rtime; 1228 in6_dev->tstamp = jiffies; 1229 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1230 } 1231 1232 rtime = ntohl(ra_msg->reachable_time); 1233 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) { 1234 rtime = (rtime*HZ)/1000; 1235 1236 if (rtime < HZ/10) 1237 rtime = HZ/10; 1238 1239 if (rtime != in6_dev->nd_parms->base_reachable_time) { 1240 in6_dev->nd_parms->base_reachable_time = rtime; 1241 in6_dev->nd_parms->gc_staletime = 3 * rtime; 1242 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime); 1243 in6_dev->tstamp = jiffies; 1244 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1245 } 1246 } 1247 } 1248 1249 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1250 skip_linkparms: 1251 #endif 1252 1253 /* 1254 * Process options. 1255 */ 1256 1257 if (!neigh) 1258 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr, 1259 skb->dev, 1); 1260 if (neigh) { 1261 u8 *lladdr = NULL; 1262 if (ndopts.nd_opts_src_lladdr) { 1263 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1264 skb->dev); 1265 if (!lladdr) { 1266 ND_PRINTK2(KERN_WARNING 1267 "ICMPv6 RA: invalid link-layer address length\n"); 1268 goto out; 1269 } 1270 } 1271 neigh_update(neigh, lladdr, NUD_STALE, 1272 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1273 NEIGH_UPDATE_F_OVERRIDE| 1274 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1275 NEIGH_UPDATE_F_ISROUTER); 1276 } 1277 1278 #ifdef CONFIG_IPV6_ROUTE_INFO 1279 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) { 1280 struct nd_opt_hdr *p; 1281 for (p = ndopts.nd_opts_ri; 1282 p; 1283 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) { 1284 struct route_info *ri = (struct route_info *)p; 1285 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1286 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT && 1287 ri->prefix_len == 0) 1288 continue; 1289 #endif 1290 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen) 1291 continue; 1292 rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3, 1293 &ipv6_hdr(skb)->saddr); 1294 } 1295 } 1296 #endif 1297 1298 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1299 /* skip link-specific ndopts from interior routers */ 1300 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) 1301 goto out; 1302 #endif 1303 1304 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) { 1305 struct nd_opt_hdr *p; 1306 for (p = ndopts.nd_opts_pi; 1307 p; 1308 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) { 1309 addrconf_prefix_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3); 1310 } 1311 } 1312 1313 if (ndopts.nd_opts_mtu) { 1314 __be32 n; 1315 u32 mtu; 1316 1317 memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); 1318 mtu = ntohl(n); 1319 1320 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { 1321 ND_PRINTK2(KERN_WARNING 1322 "ICMPv6 RA: invalid mtu: %d\n", 1323 mtu); 1324 } else if (in6_dev->cnf.mtu6 != mtu) { 1325 in6_dev->cnf.mtu6 = mtu; 1326 1327 if (rt) 1328 rt->u.dst.metrics[RTAX_MTU-1] = mtu; 1329 1330 rt6_mtu_change(skb->dev, mtu); 1331 } 1332 } 1333 1334 if (ndopts.nd_useropts) { 1335 struct nd_opt_hdr *p; 1336 for (p = ndopts.nd_useropts; 1337 p; 1338 p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) { 1339 ndisc_ra_useropt(skb, p); 1340 } 1341 } 1342 1343 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { 1344 ND_PRINTK2(KERN_WARNING 1345 "ICMPv6 RA: invalid RA options"); 1346 } 1347 out: 1348 if (rt) 1349 dst_release(&rt->u.dst); 1350 else if (neigh) 1351 neigh_release(neigh); 1352 in6_dev_put(in6_dev); 1353 } 1354 1355 static void ndisc_redirect_rcv(struct sk_buff *skb) 1356 { 1357 struct inet6_dev *in6_dev; 1358 struct icmp6hdr *icmph; 1359 struct in6_addr *dest; 1360 struct in6_addr *target; /* new first hop to destination */ 1361 struct neighbour *neigh; 1362 int on_link = 0; 1363 struct ndisc_options ndopts; 1364 int optlen; 1365 u8 *lladdr = NULL; 1366 1367 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1368 switch (skb->ndisc_nodetype) { 1369 case NDISC_NODETYPE_HOST: 1370 case NDISC_NODETYPE_NODEFAULT: 1371 ND_PRINTK2(KERN_WARNING 1372 "ICMPv6 Redirect: from host or unauthorized router\n"); 1373 return; 1374 } 1375 #endif 1376 1377 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1378 ND_PRINTK2(KERN_WARNING 1379 "ICMPv6 Redirect: source address is not link-local.\n"); 1380 return; 1381 } 1382 1383 optlen = skb->tail - skb->transport_header; 1384 optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr); 1385 1386 if (optlen < 0) { 1387 ND_PRINTK2(KERN_WARNING 1388 "ICMPv6 Redirect: packet too short\n"); 1389 return; 1390 } 1391 1392 icmph = icmp6_hdr(skb); 1393 target = (struct in6_addr *) (icmph + 1); 1394 dest = target + 1; 1395 1396 if (ipv6_addr_is_multicast(dest)) { 1397 ND_PRINTK2(KERN_WARNING 1398 "ICMPv6 Redirect: destination address is multicast.\n"); 1399 return; 1400 } 1401 1402 if (ipv6_addr_equal(dest, target)) { 1403 on_link = 1; 1404 } else if (ipv6_addr_type(target) != 1405 (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1406 ND_PRINTK2(KERN_WARNING 1407 "ICMPv6 Redirect: target address is not link-local unicast.\n"); 1408 return; 1409 } 1410 1411 in6_dev = in6_dev_get(skb->dev); 1412 if (!in6_dev) 1413 return; 1414 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) { 1415 in6_dev_put(in6_dev); 1416 return; 1417 } 1418 1419 /* RFC2461 8.1: 1420 * The IP source address of the Redirect MUST be the same as the current 1421 * first-hop router for the specified ICMP Destination Address. 1422 */ 1423 1424 if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) { 1425 ND_PRINTK2(KERN_WARNING 1426 "ICMPv6 Redirect: invalid ND options\n"); 1427 in6_dev_put(in6_dev); 1428 return; 1429 } 1430 if (ndopts.nd_opts_tgt_lladdr) { 1431 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, 1432 skb->dev); 1433 if (!lladdr) { 1434 ND_PRINTK2(KERN_WARNING 1435 "ICMPv6 Redirect: invalid link-layer address length\n"); 1436 in6_dev_put(in6_dev); 1437 return; 1438 } 1439 } 1440 1441 neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1); 1442 if (neigh) { 1443 rt6_redirect(dest, &ipv6_hdr(skb)->daddr, 1444 &ipv6_hdr(skb)->saddr, neigh, lladdr, 1445 on_link); 1446 neigh_release(neigh); 1447 } 1448 in6_dev_put(in6_dev); 1449 } 1450 1451 void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh, 1452 const struct in6_addr *target) 1453 { 1454 struct net_device *dev = skb->dev; 1455 struct net *net = dev_net(dev); 1456 struct sock *sk = net->ipv6.ndisc_sk; 1457 int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr); 1458 struct sk_buff *buff; 1459 struct icmp6hdr *icmph; 1460 struct in6_addr saddr_buf; 1461 struct in6_addr *addrp; 1462 struct rt6_info *rt; 1463 struct dst_entry *dst; 1464 struct inet6_dev *idev; 1465 struct flowi fl; 1466 u8 *opt; 1467 int rd_len; 1468 int err; 1469 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL; 1470 1471 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) { 1472 ND_PRINTK2(KERN_WARNING 1473 "ICMPv6 Redirect: no link-local address on %s\n", 1474 dev->name); 1475 return; 1476 } 1477 1478 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) && 1479 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1480 ND_PRINTK2(KERN_WARNING 1481 "ICMPv6 Redirect: target address is not link-local unicast.\n"); 1482 return; 1483 } 1484 1485 icmpv6_flow_init(sk, &fl, NDISC_REDIRECT, 1486 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex); 1487 1488 dst = ip6_route_output(net, NULL, &fl); 1489 if (dst == NULL) 1490 return; 1491 1492 err = xfrm_lookup(&dst, &fl, NULL, 0); 1493 if (err) 1494 return; 1495 1496 rt = (struct rt6_info *) dst; 1497 1498 if (rt->rt6i_flags & RTF_GATEWAY) { 1499 ND_PRINTK2(KERN_WARNING 1500 "ICMPv6 Redirect: destination is not a neighbour.\n"); 1501 dst_release(dst); 1502 return; 1503 } 1504 if (!xrlim_allow(dst, 1*HZ)) { 1505 dst_release(dst); 1506 return; 1507 } 1508 1509 if (dev->addr_len) { 1510 read_lock_bh(&neigh->lock); 1511 if (neigh->nud_state & NUD_VALID) { 1512 memcpy(ha_buf, neigh->ha, dev->addr_len); 1513 read_unlock_bh(&neigh->lock); 1514 ha = ha_buf; 1515 len += ndisc_opt_addr_space(dev); 1516 } else 1517 read_unlock_bh(&neigh->lock); 1518 } 1519 1520 rd_len = min_t(unsigned int, 1521 IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8); 1522 rd_len &= ~0x7; 1523 len += rd_len; 1524 1525 buff = sock_alloc_send_skb(sk, 1526 (MAX_HEADER + sizeof(struct ipv6hdr) + 1527 len + LL_ALLOCATED_SPACE(dev)), 1528 1, &err); 1529 if (buff == NULL) { 1530 ND_PRINTK0(KERN_ERR 1531 "ICMPv6 Redirect: %s() failed to allocate an skb.\n", 1532 __func__); 1533 dst_release(dst); 1534 return; 1535 } 1536 1537 skb_reserve(buff, LL_RESERVED_SPACE(dev)); 1538 ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr, 1539 IPPROTO_ICMPV6, len); 1540 1541 skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data); 1542 skb_put(buff, len); 1543 icmph = icmp6_hdr(buff); 1544 1545 memset(icmph, 0, sizeof(struct icmp6hdr)); 1546 icmph->icmp6_type = NDISC_REDIRECT; 1547 1548 /* 1549 * copy target and destination addresses 1550 */ 1551 1552 addrp = (struct in6_addr *)(icmph + 1); 1553 ipv6_addr_copy(addrp, target); 1554 addrp++; 1555 ipv6_addr_copy(addrp, &ipv6_hdr(skb)->daddr); 1556 1557 opt = (u8*) (addrp + 1); 1558 1559 /* 1560 * include target_address option 1561 */ 1562 1563 if (ha) 1564 opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha, 1565 dev->addr_len, dev->type); 1566 1567 /* 1568 * build redirect option and copy skb over to the new packet. 1569 */ 1570 1571 memset(opt, 0, 8); 1572 *(opt++) = ND_OPT_REDIRECT_HDR; 1573 *(opt++) = (rd_len >> 3); 1574 opt += 6; 1575 1576 memcpy(opt, ipv6_hdr(skb), rd_len - 8); 1577 1578 icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr, 1579 len, IPPROTO_ICMPV6, 1580 csum_partial((u8 *) icmph, len, 0)); 1581 1582 buff->dst = dst; 1583 idev = in6_dev_get(dst->dev); 1584 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS); 1585 err = NF_HOOK(PF_INET6, NF_INET_LOCAL_OUT, buff, NULL, dst->dev, 1586 dst_output); 1587 if (!err) { 1588 ICMP6MSGOUT_INC_STATS(net, idev, NDISC_REDIRECT); 1589 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 1590 } 1591 1592 if (likely(idev != NULL)) 1593 in6_dev_put(idev); 1594 } 1595 1596 static void pndisc_redo(struct sk_buff *skb) 1597 { 1598 ndisc_recv_ns(skb); 1599 kfree_skb(skb); 1600 } 1601 1602 int ndisc_rcv(struct sk_buff *skb) 1603 { 1604 struct nd_msg *msg; 1605 1606 if (!pskb_may_pull(skb, skb->len)) 1607 return 0; 1608 1609 msg = (struct nd_msg *)skb_transport_header(skb); 1610 1611 __skb_push(skb, skb->data - skb_transport_header(skb)); 1612 1613 if (ipv6_hdr(skb)->hop_limit != 255) { 1614 ND_PRINTK2(KERN_WARNING 1615 "ICMPv6 NDISC: invalid hop-limit: %d\n", 1616 ipv6_hdr(skb)->hop_limit); 1617 return 0; 1618 } 1619 1620 if (msg->icmph.icmp6_code != 0) { 1621 ND_PRINTK2(KERN_WARNING 1622 "ICMPv6 NDISC: invalid ICMPv6 code: %d\n", 1623 msg->icmph.icmp6_code); 1624 return 0; 1625 } 1626 1627 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 1628 1629 switch (msg->icmph.icmp6_type) { 1630 case NDISC_NEIGHBOUR_SOLICITATION: 1631 ndisc_recv_ns(skb); 1632 break; 1633 1634 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1635 ndisc_recv_na(skb); 1636 break; 1637 1638 case NDISC_ROUTER_SOLICITATION: 1639 ndisc_recv_rs(skb); 1640 break; 1641 1642 case NDISC_ROUTER_ADVERTISEMENT: 1643 ndisc_router_discovery(skb); 1644 break; 1645 1646 case NDISC_REDIRECT: 1647 ndisc_redirect_rcv(skb); 1648 break; 1649 } 1650 1651 return 0; 1652 } 1653 1654 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1655 { 1656 struct net_device *dev = ptr; 1657 struct net *net = dev_net(dev); 1658 1659 switch (event) { 1660 case NETDEV_CHANGEADDR: 1661 neigh_changeaddr(&nd_tbl, dev); 1662 fib6_run_gc(~0UL, net); 1663 break; 1664 case NETDEV_DOWN: 1665 neigh_ifdown(&nd_tbl, dev); 1666 fib6_run_gc(~0UL, net); 1667 break; 1668 default: 1669 break; 1670 } 1671 1672 return NOTIFY_DONE; 1673 } 1674 1675 static struct notifier_block ndisc_netdev_notifier = { 1676 .notifier_call = ndisc_netdev_event, 1677 }; 1678 1679 #ifdef CONFIG_SYSCTL 1680 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl, 1681 const char *func, const char *dev_name) 1682 { 1683 static char warncomm[TASK_COMM_LEN]; 1684 static int warned; 1685 if (strcmp(warncomm, current->comm) && warned < 5) { 1686 strcpy(warncomm, current->comm); 1687 printk(KERN_WARNING 1688 "process `%s' is using deprecated sysctl (%s) " 1689 "net.ipv6.neigh.%s.%s; " 1690 "Use net.ipv6.neigh.%s.%s_ms " 1691 "instead.\n", 1692 warncomm, func, 1693 dev_name, ctl->procname, 1694 dev_name, ctl->procname); 1695 warned++; 1696 } 1697 } 1698 1699 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, struct file * filp, void __user *buffer, size_t *lenp, loff_t *ppos) 1700 { 1701 struct net_device *dev = ctl->extra1; 1702 struct inet6_dev *idev; 1703 int ret; 1704 1705 if ((strcmp(ctl->procname, "retrans_time") == 0) || 1706 (strcmp(ctl->procname, "base_reachable_time") == 0)) 1707 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default"); 1708 1709 if (strcmp(ctl->procname, "retrans_time") == 0) 1710 ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos); 1711 1712 else if (strcmp(ctl->procname, "base_reachable_time") == 0) 1713 ret = proc_dointvec_jiffies(ctl, write, 1714 filp, buffer, lenp, ppos); 1715 1716 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) || 1717 (strcmp(ctl->procname, "base_reachable_time_ms") == 0)) 1718 ret = proc_dointvec_ms_jiffies(ctl, write, 1719 filp, buffer, lenp, ppos); 1720 else 1721 ret = -1; 1722 1723 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) { 1724 if (ctl->data == &idev->nd_parms->base_reachable_time) 1725 idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time); 1726 idev->tstamp = jiffies; 1727 inet6_ifinfo_notify(RTM_NEWLINK, idev); 1728 in6_dev_put(idev); 1729 } 1730 return ret; 1731 } 1732 1733 int ndisc_ifinfo_sysctl_strategy(ctl_table *ctl, 1734 void __user *oldval, size_t __user *oldlenp, 1735 void __user *newval, size_t newlen) 1736 { 1737 struct net_device *dev = ctl->extra1; 1738 struct inet6_dev *idev; 1739 int ret; 1740 1741 if (ctl->ctl_name == NET_NEIGH_RETRANS_TIME || 1742 ctl->ctl_name == NET_NEIGH_REACHABLE_TIME) 1743 ndisc_warn_deprecated_sysctl(ctl, "procfs", dev ? dev->name : "default"); 1744 1745 switch (ctl->ctl_name) { 1746 case NET_NEIGH_REACHABLE_TIME: 1747 ret = sysctl_jiffies(ctl, oldval, oldlenp, newval, newlen); 1748 break; 1749 case NET_NEIGH_RETRANS_TIME_MS: 1750 case NET_NEIGH_REACHABLE_TIME_MS: 1751 ret = sysctl_ms_jiffies(ctl, oldval, oldlenp, newval, newlen); 1752 break; 1753 default: 1754 ret = 0; 1755 } 1756 1757 if (newval && newlen && ret > 0 && 1758 dev && (idev = in6_dev_get(dev)) != NULL) { 1759 if (ctl->ctl_name == NET_NEIGH_REACHABLE_TIME || 1760 ctl->ctl_name == NET_NEIGH_REACHABLE_TIME_MS) 1761 idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time); 1762 idev->tstamp = jiffies; 1763 inet6_ifinfo_notify(RTM_NEWLINK, idev); 1764 in6_dev_put(idev); 1765 } 1766 1767 return ret; 1768 } 1769 1770 #endif 1771 1772 static int ndisc_net_init(struct net *net) 1773 { 1774 struct ipv6_pinfo *np; 1775 struct sock *sk; 1776 int err; 1777 1778 err = inet_ctl_sock_create(&sk, PF_INET6, 1779 SOCK_RAW, IPPROTO_ICMPV6, net); 1780 if (err < 0) { 1781 ND_PRINTK0(KERN_ERR 1782 "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n", 1783 err); 1784 return err; 1785 } 1786 1787 net->ipv6.ndisc_sk = sk; 1788 1789 np = inet6_sk(sk); 1790 np->hop_limit = 255; 1791 /* Do not loopback ndisc messages */ 1792 np->mc_loop = 0; 1793 1794 return 0; 1795 } 1796 1797 static void ndisc_net_exit(struct net *net) 1798 { 1799 inet_ctl_sock_destroy(net->ipv6.ndisc_sk); 1800 } 1801 1802 static struct pernet_operations ndisc_net_ops = { 1803 .init = ndisc_net_init, 1804 .exit = ndisc_net_exit, 1805 }; 1806 1807 int __init ndisc_init(void) 1808 { 1809 int err; 1810 1811 err = register_pernet_subsys(&ndisc_net_ops); 1812 if (err) 1813 return err; 1814 /* 1815 * Initialize the neighbour table 1816 */ 1817 neigh_table_init(&nd_tbl); 1818 1819 #ifdef CONFIG_SYSCTL 1820 err = neigh_sysctl_register(NULL, &nd_tbl.parms, NET_IPV6, 1821 NET_IPV6_NEIGH, "ipv6", 1822 &ndisc_ifinfo_sysctl_change, 1823 &ndisc_ifinfo_sysctl_strategy); 1824 if (err) 1825 goto out_unregister_pernet; 1826 #endif 1827 err = register_netdevice_notifier(&ndisc_netdev_notifier); 1828 if (err) 1829 goto out_unregister_sysctl; 1830 out: 1831 return err; 1832 1833 out_unregister_sysctl: 1834 #ifdef CONFIG_SYSCTL 1835 neigh_sysctl_unregister(&nd_tbl.parms); 1836 out_unregister_pernet: 1837 #endif 1838 unregister_pernet_subsys(&ndisc_net_ops); 1839 goto out; 1840 } 1841 1842 void ndisc_cleanup(void) 1843 { 1844 unregister_netdevice_notifier(&ndisc_netdev_notifier); 1845 #ifdef CONFIG_SYSCTL 1846 neigh_sysctl_unregister(&nd_tbl.parms); 1847 #endif 1848 neigh_table_clear(&nd_tbl); 1849 unregister_pernet_subsys(&ndisc_net_ops); 1850 } 1851