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, const struct net_device *dev); 95 static int ndisc_constructor(struct neighbour *neigh); 96 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb); 97 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb); 98 static int pndisc_constructor(struct pneigh_entry *n); 99 static void pndisc_destructor(struct pneigh_entry *n); 100 static void pndisc_redo(struct sk_buff *skb); 101 102 static const struct neigh_ops ndisc_generic_ops = { 103 .family = AF_INET6, 104 .solicit = ndisc_solicit, 105 .error_report = ndisc_error_report, 106 .output = neigh_resolve_output, 107 .connected_output = neigh_connected_output, 108 .hh_output = dev_queue_xmit, 109 .queue_xmit = dev_queue_xmit, 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 .hh_output = dev_queue_xmit, 119 .queue_xmit = dev_queue_xmit, 120 }; 121 122 123 static const struct neigh_ops ndisc_direct_ops = { 124 .family = AF_INET6, 125 .output = dev_queue_xmit, 126 .connected_output = dev_queue_xmit, 127 .hh_output = dev_queue_xmit, 128 .queue_xmit = dev_queue_xmit, 129 }; 130 131 struct neigh_table nd_tbl = { 132 .family = AF_INET6, 133 .entry_size = sizeof(struct neighbour) + sizeof(struct in6_addr), 134 .key_len = sizeof(struct in6_addr), 135 .hash = ndisc_hash, 136 .constructor = ndisc_constructor, 137 .pconstructor = pndisc_constructor, 138 .pdestructor = pndisc_destructor, 139 .proxy_redo = pndisc_redo, 140 .id = "ndisc_cache", 141 .parms = { 142 .tbl = &nd_tbl, 143 .base_reachable_time = 30 * HZ, 144 .retrans_time = 1 * HZ, 145 .gc_staletime = 60 * HZ, 146 .reachable_time = 30 * HZ, 147 .delay_probe_time = 5 * HZ, 148 .queue_len = 3, 149 .ucast_probes = 3, 150 .mcast_probes = 3, 151 .anycast_delay = 1 * HZ, 152 .proxy_delay = (8 * HZ) / 10, 153 .proxy_qlen = 64, 154 }, 155 .gc_interval = 30 * HZ, 156 .gc_thresh1 = 128, 157 .gc_thresh2 = 512, 158 .gc_thresh3 = 1024, 159 }; 160 161 /* ND options */ 162 struct ndisc_options { 163 struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX]; 164 #ifdef CONFIG_IPV6_ROUTE_INFO 165 struct nd_opt_hdr *nd_opts_ri; 166 struct nd_opt_hdr *nd_opts_ri_end; 167 #endif 168 struct nd_opt_hdr *nd_useropts; 169 struct nd_opt_hdr *nd_useropts_end; 170 }; 171 172 #define nd_opts_src_lladdr nd_opt_array[ND_OPT_SOURCE_LL_ADDR] 173 #define nd_opts_tgt_lladdr nd_opt_array[ND_OPT_TARGET_LL_ADDR] 174 #define nd_opts_pi nd_opt_array[ND_OPT_PREFIX_INFO] 175 #define nd_opts_pi_end nd_opt_array[__ND_OPT_PREFIX_INFO_END] 176 #define nd_opts_rh nd_opt_array[ND_OPT_REDIRECT_HDR] 177 #define nd_opts_mtu nd_opt_array[ND_OPT_MTU] 178 179 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7) 180 181 /* 182 * Return the padding between the option length and the start of the 183 * link addr. Currently only IP-over-InfiniBand needs this, although 184 * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may 185 * also need a pad of 2. 186 */ 187 static int ndisc_addr_option_pad(unsigned short type) 188 { 189 switch (type) { 190 case ARPHRD_INFINIBAND: return 2; 191 default: return 0; 192 } 193 } 194 195 static inline int ndisc_opt_addr_space(struct net_device *dev) 196 { 197 return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type)); 198 } 199 200 static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len, 201 unsigned short addr_type) 202 { 203 int space = NDISC_OPT_SPACE(data_len); 204 int pad = ndisc_addr_option_pad(addr_type); 205 206 opt[0] = type; 207 opt[1] = space>>3; 208 209 memset(opt + 2, 0, pad); 210 opt += pad; 211 space -= pad; 212 213 memcpy(opt+2, data, data_len); 214 data_len += 2; 215 opt += data_len; 216 if ((space -= data_len) > 0) 217 memset(opt, 0, space); 218 return opt + space; 219 } 220 221 static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur, 222 struct nd_opt_hdr *end) 223 { 224 int type; 225 if (!cur || !end || cur >= end) 226 return NULL; 227 type = cur->nd_opt_type; 228 do { 229 cur = ((void *)cur) + (cur->nd_opt_len << 3); 230 } while(cur < end && cur->nd_opt_type != type); 231 return (cur <= end && cur->nd_opt_type == type ? cur : NULL); 232 } 233 234 static inline int ndisc_is_useropt(struct nd_opt_hdr *opt) 235 { 236 return (opt->nd_opt_type == ND_OPT_RDNSS); 237 } 238 239 static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur, 240 struct nd_opt_hdr *end) 241 { 242 if (!cur || !end || cur >= end) 243 return NULL; 244 do { 245 cur = ((void *)cur) + (cur->nd_opt_len << 3); 246 } while(cur < end && !ndisc_is_useropt(cur)); 247 return (cur <= end && ndisc_is_useropt(cur) ? cur : NULL); 248 } 249 250 static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len, 251 struct ndisc_options *ndopts) 252 { 253 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt; 254 255 if (!nd_opt || opt_len < 0 || !ndopts) 256 return NULL; 257 memset(ndopts, 0, sizeof(*ndopts)); 258 while (opt_len) { 259 int l; 260 if (opt_len < sizeof(struct nd_opt_hdr)) 261 return NULL; 262 l = nd_opt->nd_opt_len << 3; 263 if (opt_len < l || l == 0) 264 return NULL; 265 switch (nd_opt->nd_opt_type) { 266 case ND_OPT_SOURCE_LL_ADDR: 267 case ND_OPT_TARGET_LL_ADDR: 268 case ND_OPT_MTU: 269 case ND_OPT_REDIRECT_HDR: 270 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { 271 ND_PRINTK2(KERN_WARNING 272 "%s(): duplicated ND6 option found: type=%d\n", 273 __func__, 274 nd_opt->nd_opt_type); 275 } else { 276 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; 277 } 278 break; 279 case ND_OPT_PREFIX_INFO: 280 ndopts->nd_opts_pi_end = nd_opt; 281 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type]) 282 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; 283 break; 284 #ifdef CONFIG_IPV6_ROUTE_INFO 285 case ND_OPT_ROUTE_INFO: 286 ndopts->nd_opts_ri_end = nd_opt; 287 if (!ndopts->nd_opts_ri) 288 ndopts->nd_opts_ri = nd_opt; 289 break; 290 #endif 291 default: 292 if (ndisc_is_useropt(nd_opt)) { 293 ndopts->nd_useropts_end = nd_opt; 294 if (!ndopts->nd_useropts) 295 ndopts->nd_useropts = nd_opt; 296 } else { 297 /* 298 * Unknown options must be silently ignored, 299 * to accommodate future extension to the 300 * protocol. 301 */ 302 ND_PRINTK2(KERN_NOTICE 303 "%s(): ignored unsupported option; type=%d, len=%d\n", 304 __func__, 305 nd_opt->nd_opt_type, nd_opt->nd_opt_len); 306 } 307 } 308 opt_len -= l; 309 nd_opt = ((void *)nd_opt) + l; 310 } 311 return ndopts; 312 } 313 314 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p, 315 struct net_device *dev) 316 { 317 u8 *lladdr = (u8 *)(p + 1); 318 int lladdrlen = p->nd_opt_len << 3; 319 int prepad = ndisc_addr_option_pad(dev->type); 320 if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad)) 321 return NULL; 322 return (lladdr + prepad); 323 } 324 325 int ndisc_mc_map(struct in6_addr *addr, char *buf, struct net_device *dev, int dir) 326 { 327 switch (dev->type) { 328 case ARPHRD_ETHER: 329 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */ 330 case ARPHRD_FDDI: 331 ipv6_eth_mc_map(addr, buf); 332 return 0; 333 case ARPHRD_IEEE802_TR: 334 ipv6_tr_mc_map(addr,buf); 335 return 0; 336 case ARPHRD_ARCNET: 337 ipv6_arcnet_mc_map(addr, buf); 338 return 0; 339 case ARPHRD_INFINIBAND: 340 ipv6_ib_mc_map(addr, dev->broadcast, buf); 341 return 0; 342 default: 343 if (dir) { 344 memcpy(buf, dev->broadcast, dev->addr_len); 345 return 0; 346 } 347 } 348 return -EINVAL; 349 } 350 351 EXPORT_SYMBOL(ndisc_mc_map); 352 353 static u32 ndisc_hash(const void *pkey, const struct net_device *dev) 354 { 355 const u32 *p32 = pkey; 356 u32 addr_hash, i; 357 358 addr_hash = 0; 359 for (i = 0; i < (sizeof(struct in6_addr) / sizeof(u32)); i++) 360 addr_hash ^= *p32++; 361 362 return jhash_2words(addr_hash, dev->ifindex, nd_tbl.hash_rnd); 363 } 364 365 static int ndisc_constructor(struct neighbour *neigh) 366 { 367 struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key; 368 struct net_device *dev = neigh->dev; 369 struct inet6_dev *in6_dev; 370 struct neigh_parms *parms; 371 int is_multicast = ipv6_addr_is_multicast(addr); 372 373 rcu_read_lock(); 374 in6_dev = in6_dev_get(dev); 375 if (in6_dev == NULL) { 376 rcu_read_unlock(); 377 return -EINVAL; 378 } 379 380 parms = in6_dev->nd_parms; 381 __neigh_parms_put(neigh->parms); 382 neigh->parms = neigh_parms_clone(parms); 383 rcu_read_unlock(); 384 385 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST; 386 if (!dev->header_ops) { 387 neigh->nud_state = NUD_NOARP; 388 neigh->ops = &ndisc_direct_ops; 389 neigh->output = neigh->ops->queue_xmit; 390 } else { 391 if (is_multicast) { 392 neigh->nud_state = NUD_NOARP; 393 ndisc_mc_map(addr, neigh->ha, dev, 1); 394 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { 395 neigh->nud_state = NUD_NOARP; 396 memcpy(neigh->ha, dev->dev_addr, dev->addr_len); 397 if (dev->flags&IFF_LOOPBACK) 398 neigh->type = RTN_LOCAL; 399 } else if (dev->flags&IFF_POINTOPOINT) { 400 neigh->nud_state = NUD_NOARP; 401 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 402 } 403 if (dev->header_ops->cache) 404 neigh->ops = &ndisc_hh_ops; 405 else 406 neigh->ops = &ndisc_generic_ops; 407 if (neigh->nud_state&NUD_VALID) 408 neigh->output = neigh->ops->connected_output; 409 else 410 neigh->output = neigh->ops->output; 411 } 412 in6_dev_put(in6_dev); 413 return 0; 414 } 415 416 static int pndisc_constructor(struct pneigh_entry *n) 417 { 418 struct in6_addr *addr = (struct in6_addr*)&n->key; 419 struct in6_addr maddr; 420 struct net_device *dev = n->dev; 421 422 if (dev == NULL || __in6_dev_get(dev) == NULL) 423 return -EINVAL; 424 addrconf_addr_solict_mult(addr, &maddr); 425 ipv6_dev_mc_inc(dev, &maddr); 426 return 0; 427 } 428 429 static void pndisc_destructor(struct pneigh_entry *n) 430 { 431 struct in6_addr *addr = (struct in6_addr*)&n->key; 432 struct in6_addr maddr; 433 struct net_device *dev = n->dev; 434 435 if (dev == NULL || __in6_dev_get(dev) == NULL) 436 return; 437 addrconf_addr_solict_mult(addr, &maddr); 438 ipv6_dev_mc_dec(dev, &maddr); 439 } 440 441 struct sk_buff *ndisc_build_skb(struct net_device *dev, 442 const struct in6_addr *daddr, 443 const struct in6_addr *saddr, 444 struct icmp6hdr *icmp6h, 445 const struct in6_addr *target, 446 int llinfo) 447 { 448 struct net *net = dev_net(dev); 449 struct sock *sk = net->ipv6.ndisc_sk; 450 struct sk_buff *skb; 451 struct icmp6hdr *hdr; 452 int len; 453 int err; 454 u8 *opt; 455 456 if (!dev->addr_len) 457 llinfo = 0; 458 459 len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0); 460 if (llinfo) 461 len += ndisc_opt_addr_space(dev); 462 463 skb = sock_alloc_send_skb(sk, 464 (MAX_HEADER + sizeof(struct ipv6hdr) + 465 len + LL_ALLOCATED_SPACE(dev)), 466 1, &err); 467 if (!skb) { 468 ND_PRINTK0(KERN_ERR 469 "ICMPv6 ND: %s() failed to allocate an skb, err=%d.\n", 470 __func__, err); 471 return NULL; 472 } 473 474 skb_reserve(skb, LL_RESERVED_SPACE(dev)); 475 ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len); 476 477 skb->transport_header = skb->tail; 478 skb_put(skb, len); 479 480 hdr = (struct icmp6hdr *)skb_transport_header(skb); 481 memcpy(hdr, icmp6h, sizeof(*hdr)); 482 483 opt = skb_transport_header(skb) + sizeof(struct icmp6hdr); 484 if (target) { 485 ipv6_addr_copy((struct in6_addr *)opt, target); 486 opt += sizeof(*target); 487 } 488 489 if (llinfo) 490 ndisc_fill_addr_option(opt, llinfo, dev->dev_addr, 491 dev->addr_len, dev->type); 492 493 hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len, 494 IPPROTO_ICMPV6, 495 csum_partial(hdr, 496 len, 0)); 497 498 return skb; 499 } 500 501 EXPORT_SYMBOL(ndisc_build_skb); 502 503 void ndisc_send_skb(struct sk_buff *skb, 504 struct net_device *dev, 505 struct neighbour *neigh, 506 const struct in6_addr *daddr, 507 const struct in6_addr *saddr, 508 struct icmp6hdr *icmp6h) 509 { 510 struct flowi fl; 511 struct dst_entry *dst; 512 struct net *net = dev_net(dev); 513 struct sock *sk = net->ipv6.ndisc_sk; 514 struct inet6_dev *idev; 515 int err; 516 u8 type; 517 518 type = icmp6h->icmp6_type; 519 520 icmpv6_flow_init(sk, &fl, type, saddr, daddr, dev->ifindex); 521 522 dst = icmp6_dst_alloc(dev, neigh, daddr); 523 if (!dst) { 524 kfree_skb(skb); 525 return; 526 } 527 528 err = xfrm_lookup(net, &dst, &fl, NULL, 0); 529 if (err < 0) { 530 kfree_skb(skb); 531 return; 532 } 533 534 skb_dst_set(skb, dst); 535 536 idev = in6_dev_get(dst->dev); 537 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len); 538 539 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev, 540 dst_output); 541 if (!err) { 542 ICMP6MSGOUT_INC_STATS(net, idev, type); 543 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 544 } 545 546 if (likely(idev != NULL)) 547 in6_dev_put(idev); 548 } 549 550 EXPORT_SYMBOL(ndisc_send_skb); 551 552 /* 553 * Send a Neighbour Discover packet 554 */ 555 static void __ndisc_send(struct net_device *dev, 556 struct neighbour *neigh, 557 const struct in6_addr *daddr, 558 const struct in6_addr *saddr, 559 struct icmp6hdr *icmp6h, const struct in6_addr *target, 560 int llinfo) 561 { 562 struct sk_buff *skb; 563 564 skb = ndisc_build_skb(dev, daddr, saddr, icmp6h, target, llinfo); 565 if (!skb) 566 return; 567 568 ndisc_send_skb(skb, dev, neigh, daddr, saddr, icmp6h); 569 } 570 571 static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh, 572 const struct in6_addr *daddr, 573 const struct in6_addr *solicited_addr, 574 int router, int solicited, int override, int inc_opt) 575 { 576 struct in6_addr tmpaddr; 577 struct inet6_ifaddr *ifp; 578 const struct in6_addr *src_addr; 579 struct icmp6hdr icmp6h = { 580 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT, 581 }; 582 583 /* for anycast or proxy, solicited_addr != src_addr */ 584 ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1); 585 if (ifp) { 586 src_addr = solicited_addr; 587 if (ifp->flags & IFA_F_OPTIMISTIC) 588 override = 0; 589 inc_opt |= ifp->idev->cnf.force_tllao; 590 in6_ifa_put(ifp); 591 } else { 592 if (ipv6_dev_get_saddr(dev_net(dev), dev, daddr, 593 inet6_sk(dev_net(dev)->ipv6.ndisc_sk)->srcprefs, 594 &tmpaddr)) 595 return; 596 src_addr = &tmpaddr; 597 } 598 599 icmp6h.icmp6_router = router; 600 icmp6h.icmp6_solicited = solicited; 601 icmp6h.icmp6_override = override; 602 603 __ndisc_send(dev, neigh, daddr, src_addr, 604 &icmp6h, solicited_addr, 605 inc_opt ? ND_OPT_TARGET_LL_ADDR : 0); 606 } 607 608 void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh, 609 const struct in6_addr *solicit, 610 const struct in6_addr *daddr, const struct in6_addr *saddr) 611 { 612 struct in6_addr addr_buf; 613 struct icmp6hdr icmp6h = { 614 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION, 615 }; 616 617 if (saddr == NULL) { 618 if (ipv6_get_lladdr(dev, &addr_buf, 619 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))) 620 return; 621 saddr = &addr_buf; 622 } 623 624 __ndisc_send(dev, neigh, daddr, saddr, 625 &icmp6h, solicit, 626 !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0); 627 } 628 629 void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr, 630 const struct in6_addr *daddr) 631 { 632 struct icmp6hdr icmp6h = { 633 .icmp6_type = NDISC_ROUTER_SOLICITATION, 634 }; 635 int send_sllao = dev->addr_len; 636 637 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 638 /* 639 * According to section 2.2 of RFC 4429, we must not 640 * send router solicitations with a sllao from 641 * optimistic addresses, but we may send the solicitation 642 * if we don't include the sllao. So here we check 643 * if our address is optimistic, and if so, we 644 * suppress the inclusion of the sllao. 645 */ 646 if (send_sllao) { 647 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(dev_net(dev), saddr, 648 dev, 1); 649 if (ifp) { 650 if (ifp->flags & IFA_F_OPTIMISTIC) { 651 send_sllao = 0; 652 } 653 in6_ifa_put(ifp); 654 } else { 655 send_sllao = 0; 656 } 657 } 658 #endif 659 __ndisc_send(dev, NULL, daddr, saddr, 660 &icmp6h, NULL, 661 send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0); 662 } 663 664 665 static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb) 666 { 667 /* 668 * "The sender MUST return an ICMP 669 * destination unreachable" 670 */ 671 dst_link_failure(skb); 672 kfree_skb(skb); 673 } 674 675 /* Called with locked neigh: either read or both */ 676 677 static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb) 678 { 679 struct in6_addr *saddr = NULL; 680 struct in6_addr mcaddr; 681 struct net_device *dev = neigh->dev; 682 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key; 683 int probes = atomic_read(&neigh->probes); 684 685 if (skb && ipv6_chk_addr(dev_net(dev), &ipv6_hdr(skb)->saddr, dev, 1)) 686 saddr = &ipv6_hdr(skb)->saddr; 687 688 if ((probes -= neigh->parms->ucast_probes) < 0) { 689 if (!(neigh->nud_state & NUD_VALID)) { 690 ND_PRINTK1(KERN_DEBUG "%s(): trying to ucast probe in NUD_INVALID: %pI6\n", 691 __func__, target); 692 } 693 ndisc_send_ns(dev, neigh, target, target, saddr); 694 } else if ((probes -= neigh->parms->app_probes) < 0) { 695 #ifdef CONFIG_ARPD 696 neigh_app_ns(neigh); 697 #endif 698 } else { 699 addrconf_addr_solict_mult(target, &mcaddr); 700 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr); 701 } 702 } 703 704 static int pndisc_is_router(const void *pkey, 705 struct net_device *dev) 706 { 707 struct pneigh_entry *n; 708 int ret = -1; 709 710 read_lock_bh(&nd_tbl.lock); 711 n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev); 712 if (n) 713 ret = !!(n->flags & NTF_ROUTER); 714 read_unlock_bh(&nd_tbl.lock); 715 716 return ret; 717 } 718 719 static void ndisc_recv_ns(struct sk_buff *skb) 720 { 721 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 722 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 723 struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 724 u8 *lladdr = NULL; 725 u32 ndoptlen = skb->tail - (skb->transport_header + 726 offsetof(struct nd_msg, opt)); 727 struct ndisc_options ndopts; 728 struct net_device *dev = skb->dev; 729 struct inet6_ifaddr *ifp; 730 struct inet6_dev *idev = NULL; 731 struct neighbour *neigh; 732 int dad = ipv6_addr_any(saddr); 733 int inc; 734 int is_router = -1; 735 736 if (ipv6_addr_is_multicast(&msg->target)) { 737 ND_PRINTK2(KERN_WARNING 738 "ICMPv6 NS: multicast target address"); 739 return; 740 } 741 742 /* 743 * RFC2461 7.1.1: 744 * DAD has to be destined for solicited node multicast address. 745 */ 746 if (dad && 747 !(daddr->s6_addr32[0] == htonl(0xff020000) && 748 daddr->s6_addr32[1] == htonl(0x00000000) && 749 daddr->s6_addr32[2] == htonl(0x00000001) && 750 daddr->s6_addr [12] == 0xff )) { 751 ND_PRINTK2(KERN_WARNING 752 "ICMPv6 NS: bad DAD packet (wrong destination)\n"); 753 return; 754 } 755 756 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { 757 ND_PRINTK2(KERN_WARNING 758 "ICMPv6 NS: invalid ND options\n"); 759 return; 760 } 761 762 if (ndopts.nd_opts_src_lladdr) { 763 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev); 764 if (!lladdr) { 765 ND_PRINTK2(KERN_WARNING 766 "ICMPv6 NS: invalid link-layer address length\n"); 767 return; 768 } 769 770 /* RFC2461 7.1.1: 771 * If the IP source address is the unspecified address, 772 * there MUST NOT be source link-layer address option 773 * in the message. 774 */ 775 if (dad) { 776 ND_PRINTK2(KERN_WARNING 777 "ICMPv6 NS: bad DAD packet (link-layer address option)\n"); 778 return; 779 } 780 } 781 782 inc = ipv6_addr_is_multicast(daddr); 783 784 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); 785 if (ifp) { 786 787 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) { 788 if (dad) { 789 if (dev->type == ARPHRD_IEEE802_TR) { 790 const unsigned char *sadr; 791 sadr = skb_mac_header(skb); 792 if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 && 793 sadr[9] == dev->dev_addr[1] && 794 sadr[10] == dev->dev_addr[2] && 795 sadr[11] == dev->dev_addr[3] && 796 sadr[12] == dev->dev_addr[4] && 797 sadr[13] == dev->dev_addr[5]) { 798 /* looped-back to us */ 799 goto out; 800 } 801 } 802 803 /* 804 * We are colliding with another node 805 * who is doing DAD 806 * so fail our DAD process 807 */ 808 addrconf_dad_failure(ifp); 809 return; 810 } else { 811 /* 812 * This is not a dad solicitation. 813 * If we are an optimistic node, 814 * we should respond. 815 * Otherwise, we should ignore it. 816 */ 817 if (!(ifp->flags & IFA_F_OPTIMISTIC)) 818 goto out; 819 } 820 } 821 822 idev = ifp->idev; 823 } else { 824 struct net *net = dev_net(dev); 825 826 idev = in6_dev_get(dev); 827 if (!idev) { 828 /* XXX: count this drop? */ 829 return; 830 } 831 832 if (ipv6_chk_acast_addr(net, dev, &msg->target) || 833 (idev->cnf.forwarding && 834 (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) && 835 (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) { 836 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) && 837 skb->pkt_type != PACKET_HOST && 838 inc != 0 && 839 idev->nd_parms->proxy_delay != 0) { 840 /* 841 * for anycast or proxy, 842 * sender should delay its response 843 * by a random time between 0 and 844 * MAX_ANYCAST_DELAY_TIME seconds. 845 * (RFC2461) -- yoshfuji 846 */ 847 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC); 848 if (n) 849 pneigh_enqueue(&nd_tbl, idev->nd_parms, n); 850 goto out; 851 } 852 } else 853 goto out; 854 } 855 856 if (is_router < 0) 857 is_router = !!idev->cnf.forwarding; 858 859 if (dad) { 860 ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target, 861 is_router, 0, (ifp != NULL), 1); 862 goto out; 863 } 864 865 if (inc) 866 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast); 867 else 868 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast); 869 870 /* 871 * update / create cache entry 872 * for the source address 873 */ 874 neigh = __neigh_lookup(&nd_tbl, saddr, dev, 875 !inc || lladdr || !dev->addr_len); 876 if (neigh) 877 neigh_update(neigh, lladdr, NUD_STALE, 878 NEIGH_UPDATE_F_WEAK_OVERRIDE| 879 NEIGH_UPDATE_F_OVERRIDE); 880 if (neigh || !dev->header_ops) { 881 ndisc_send_na(dev, neigh, saddr, &msg->target, 882 is_router, 883 1, (ifp != NULL && inc), inc); 884 if (neigh) 885 neigh_release(neigh); 886 } 887 888 out: 889 if (ifp) 890 in6_ifa_put(ifp); 891 else 892 in6_dev_put(idev); 893 } 894 895 static void ndisc_recv_na(struct sk_buff *skb) 896 { 897 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 898 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 899 struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 900 u8 *lladdr = NULL; 901 u32 ndoptlen = skb->tail - (skb->transport_header + 902 offsetof(struct nd_msg, opt)); 903 struct ndisc_options ndopts; 904 struct net_device *dev = skb->dev; 905 struct inet6_ifaddr *ifp; 906 struct neighbour *neigh; 907 908 if (skb->len < sizeof(struct nd_msg)) { 909 ND_PRINTK2(KERN_WARNING 910 "ICMPv6 NA: packet too short\n"); 911 return; 912 } 913 914 if (ipv6_addr_is_multicast(&msg->target)) { 915 ND_PRINTK2(KERN_WARNING 916 "ICMPv6 NA: target address is multicast.\n"); 917 return; 918 } 919 920 if (ipv6_addr_is_multicast(daddr) && 921 msg->icmph.icmp6_solicited) { 922 ND_PRINTK2(KERN_WARNING 923 "ICMPv6 NA: solicited NA is multicasted.\n"); 924 return; 925 } 926 927 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { 928 ND_PRINTK2(KERN_WARNING 929 "ICMPv6 NS: invalid ND option\n"); 930 return; 931 } 932 if (ndopts.nd_opts_tgt_lladdr) { 933 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev); 934 if (!lladdr) { 935 ND_PRINTK2(KERN_WARNING 936 "ICMPv6 NA: invalid link-layer address length\n"); 937 return; 938 } 939 } 940 ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1); 941 if (ifp) { 942 if (ifp->flags & IFA_F_TENTATIVE) { 943 addrconf_dad_failure(ifp); 944 return; 945 } 946 /* What should we make now? The advertisement 947 is invalid, but ndisc specs say nothing 948 about it. It could be misconfiguration, or 949 an smart proxy agent tries to help us :-) 950 951 We should not print the error if NA has been 952 received from loopback - it is just our own 953 unsolicited advertisement. 954 */ 955 if (skb->pkt_type != PACKET_LOOPBACK) 956 ND_PRINTK1(KERN_WARNING 957 "ICMPv6 NA: someone advertises our address %pI6 on %s!\n", 958 &ifp->addr, ifp->idev->dev->name); 959 in6_ifa_put(ifp); 960 return; 961 } 962 neigh = neigh_lookup(&nd_tbl, &msg->target, dev); 963 964 if (neigh) { 965 u8 old_flags = neigh->flags; 966 struct net *net = dev_net(dev); 967 968 if (neigh->nud_state & NUD_FAILED) 969 goto out; 970 971 /* 972 * Don't update the neighbor cache entry on a proxy NA from 973 * ourselves because either the proxied node is off link or it 974 * has already sent a NA to us. 975 */ 976 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) && 977 net->ipv6.devconf_all->forwarding && net->ipv6.devconf_all->proxy_ndp && 978 pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) { 979 /* XXX: idev->cnf.prixy_ndp */ 980 goto out; 981 } 982 983 neigh_update(neigh, lladdr, 984 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE, 985 NEIGH_UPDATE_F_WEAK_OVERRIDE| 986 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)| 987 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 988 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0)); 989 990 if ((old_flags & ~neigh->flags) & NTF_ROUTER) { 991 /* 992 * Change: router to host 993 */ 994 struct rt6_info *rt; 995 rt = rt6_get_dflt_router(saddr, dev); 996 if (rt) 997 ip6_del_rt(rt); 998 } 999 1000 out: 1001 neigh_release(neigh); 1002 } 1003 } 1004 1005 static void ndisc_recv_rs(struct sk_buff *skb) 1006 { 1007 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb); 1008 unsigned long ndoptlen = skb->len - sizeof(*rs_msg); 1009 struct neighbour *neigh; 1010 struct inet6_dev *idev; 1011 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 1012 struct ndisc_options ndopts; 1013 u8 *lladdr = NULL; 1014 1015 if (skb->len < sizeof(*rs_msg)) 1016 return; 1017 1018 idev = in6_dev_get(skb->dev); 1019 if (!idev) { 1020 if (net_ratelimit()) 1021 ND_PRINTK1("ICMP6 RS: can't find in6 device\n"); 1022 return; 1023 } 1024 1025 /* Don't accept RS if we're not in router mode */ 1026 if (!idev->cnf.forwarding) 1027 goto out; 1028 1029 /* 1030 * Don't update NCE if src = ::; 1031 * this implies that the source node has no ip address assigned yet. 1032 */ 1033 if (ipv6_addr_any(saddr)) 1034 goto out; 1035 1036 /* Parse ND options */ 1037 if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) { 1038 if (net_ratelimit()) 1039 ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n"); 1040 goto out; 1041 } 1042 1043 if (ndopts.nd_opts_src_lladdr) { 1044 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1045 skb->dev); 1046 if (!lladdr) 1047 goto out; 1048 } 1049 1050 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1); 1051 if (neigh) { 1052 neigh_update(neigh, lladdr, NUD_STALE, 1053 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1054 NEIGH_UPDATE_F_OVERRIDE| 1055 NEIGH_UPDATE_F_OVERRIDE_ISROUTER); 1056 neigh_release(neigh); 1057 } 1058 out: 1059 in6_dev_put(idev); 1060 } 1061 1062 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt) 1063 { 1064 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra); 1065 struct sk_buff *skb; 1066 struct nlmsghdr *nlh; 1067 struct nduseroptmsg *ndmsg; 1068 struct net *net = dev_net(ra->dev); 1069 int err; 1070 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg) 1071 + (opt->nd_opt_len << 3)); 1072 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr)); 1073 1074 skb = nlmsg_new(msg_size, GFP_ATOMIC); 1075 if (skb == NULL) { 1076 err = -ENOBUFS; 1077 goto errout; 1078 } 1079 1080 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0); 1081 if (nlh == NULL) { 1082 goto nla_put_failure; 1083 } 1084 1085 ndmsg = nlmsg_data(nlh); 1086 ndmsg->nduseropt_family = AF_INET6; 1087 ndmsg->nduseropt_ifindex = ra->dev->ifindex; 1088 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type; 1089 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code; 1090 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3; 1091 1092 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3); 1093 1094 NLA_PUT(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr), 1095 &ipv6_hdr(ra)->saddr); 1096 nlmsg_end(skb, nlh); 1097 1098 rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC); 1099 return; 1100 1101 nla_put_failure: 1102 nlmsg_free(skb); 1103 err = -EMSGSIZE; 1104 errout: 1105 rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err); 1106 } 1107 1108 static void ndisc_router_discovery(struct sk_buff *skb) 1109 { 1110 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb); 1111 struct neighbour *neigh = NULL; 1112 struct inet6_dev *in6_dev; 1113 struct rt6_info *rt = NULL; 1114 int lifetime; 1115 struct ndisc_options ndopts; 1116 int optlen; 1117 unsigned int pref = 0; 1118 1119 __u8 * opt = (__u8 *)(ra_msg + 1); 1120 1121 optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg); 1122 1123 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1124 ND_PRINTK2(KERN_WARNING 1125 "ICMPv6 RA: source address is not link-local.\n"); 1126 return; 1127 } 1128 if (optlen < 0) { 1129 ND_PRINTK2(KERN_WARNING 1130 "ICMPv6 RA: packet too short\n"); 1131 return; 1132 } 1133 1134 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1135 if (skb->ndisc_nodetype == NDISC_NODETYPE_HOST) { 1136 ND_PRINTK2(KERN_WARNING 1137 "ICMPv6 RA: from host or unauthorized router\n"); 1138 return; 1139 } 1140 #endif 1141 1142 /* 1143 * set the RA_RECV flag in the interface 1144 */ 1145 1146 in6_dev = in6_dev_get(skb->dev); 1147 if (in6_dev == NULL) { 1148 ND_PRINTK0(KERN_ERR 1149 "ICMPv6 RA: can't find inet6 device for %s.\n", 1150 skb->dev->name); 1151 return; 1152 } 1153 1154 if (!ndisc_parse_options(opt, optlen, &ndopts)) { 1155 in6_dev_put(in6_dev); 1156 ND_PRINTK2(KERN_WARNING 1157 "ICMP6 RA: invalid ND options\n"); 1158 return; 1159 } 1160 1161 /* skip route and link configuration on routers */ 1162 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra) 1163 goto skip_linkparms; 1164 1165 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1166 /* skip link-specific parameters from interior routers */ 1167 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) 1168 goto skip_linkparms; 1169 #endif 1170 1171 if (in6_dev->if_flags & IF_RS_SENT) { 1172 /* 1173 * flag that an RA was received after an RS was sent 1174 * out on this interface. 1175 */ 1176 in6_dev->if_flags |= IF_RA_RCVD; 1177 } 1178 1179 /* 1180 * Remember the managed/otherconf flags from most recently 1181 * received RA message (RFC 2462) -- yoshfuji 1182 */ 1183 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED | 1184 IF_RA_OTHERCONF)) | 1185 (ra_msg->icmph.icmp6_addrconf_managed ? 1186 IF_RA_MANAGED : 0) | 1187 (ra_msg->icmph.icmp6_addrconf_other ? 1188 IF_RA_OTHERCONF : 0); 1189 1190 if (!in6_dev->cnf.accept_ra_defrtr) 1191 goto skip_defrtr; 1192 1193 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); 1194 1195 #ifdef CONFIG_IPV6_ROUTER_PREF 1196 pref = ra_msg->icmph.icmp6_router_pref; 1197 /* 10b is handled as if it were 00b (medium) */ 1198 if (pref == ICMPV6_ROUTER_PREF_INVALID || 1199 !in6_dev->cnf.accept_ra_rtr_pref) 1200 pref = ICMPV6_ROUTER_PREF_MEDIUM; 1201 #endif 1202 1203 rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev); 1204 1205 if (rt) 1206 neigh = rt->rt6i_nexthop; 1207 1208 if (rt && lifetime == 0) { 1209 neigh_clone(neigh); 1210 ip6_del_rt(rt); 1211 rt = NULL; 1212 } 1213 1214 if (rt == NULL && lifetime) { 1215 ND_PRINTK3(KERN_DEBUG 1216 "ICMPv6 RA: adding default router.\n"); 1217 1218 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref); 1219 if (rt == NULL) { 1220 ND_PRINTK0(KERN_ERR 1221 "ICMPv6 RA: %s() failed to add default route.\n", 1222 __func__); 1223 in6_dev_put(in6_dev); 1224 return; 1225 } 1226 1227 neigh = rt->rt6i_nexthop; 1228 if (neigh == NULL) { 1229 ND_PRINTK0(KERN_ERR 1230 "ICMPv6 RA: %s() got default router without neighbour.\n", 1231 __func__); 1232 dst_release(&rt->dst); 1233 in6_dev_put(in6_dev); 1234 return; 1235 } 1236 neigh->flags |= NTF_ROUTER; 1237 } else if (rt) { 1238 rt->rt6i_flags = (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 1239 } 1240 1241 if (rt) 1242 rt->rt6i_expires = jiffies + (HZ * lifetime); 1243 1244 if (ra_msg->icmph.icmp6_hop_limit) { 1245 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit; 1246 if (rt) 1247 rt->dst.metrics[RTAX_HOPLIMIT-1] = ra_msg->icmph.icmp6_hop_limit; 1248 } 1249 1250 skip_defrtr: 1251 1252 /* 1253 * Update Reachable Time and Retrans Timer 1254 */ 1255 1256 if (in6_dev->nd_parms) { 1257 unsigned long rtime = ntohl(ra_msg->retrans_timer); 1258 1259 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) { 1260 rtime = (rtime*HZ)/1000; 1261 if (rtime < HZ/10) 1262 rtime = HZ/10; 1263 in6_dev->nd_parms->retrans_time = rtime; 1264 in6_dev->tstamp = jiffies; 1265 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1266 } 1267 1268 rtime = ntohl(ra_msg->reachable_time); 1269 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) { 1270 rtime = (rtime*HZ)/1000; 1271 1272 if (rtime < HZ/10) 1273 rtime = HZ/10; 1274 1275 if (rtime != in6_dev->nd_parms->base_reachable_time) { 1276 in6_dev->nd_parms->base_reachable_time = rtime; 1277 in6_dev->nd_parms->gc_staletime = 3 * rtime; 1278 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime); 1279 in6_dev->tstamp = jiffies; 1280 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1281 } 1282 } 1283 } 1284 1285 skip_linkparms: 1286 1287 /* 1288 * Process options. 1289 */ 1290 1291 if (!neigh) 1292 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr, 1293 skb->dev, 1); 1294 if (neigh) { 1295 u8 *lladdr = NULL; 1296 if (ndopts.nd_opts_src_lladdr) { 1297 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1298 skb->dev); 1299 if (!lladdr) { 1300 ND_PRINTK2(KERN_WARNING 1301 "ICMPv6 RA: invalid link-layer address length\n"); 1302 goto out; 1303 } 1304 } 1305 neigh_update(neigh, lladdr, NUD_STALE, 1306 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1307 NEIGH_UPDATE_F_OVERRIDE| 1308 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1309 NEIGH_UPDATE_F_ISROUTER); 1310 } 1311 1312 /* skip route and link configuration on routers */ 1313 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra) 1314 goto out; 1315 1316 #ifdef CONFIG_IPV6_ROUTE_INFO 1317 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) { 1318 struct nd_opt_hdr *p; 1319 for (p = ndopts.nd_opts_ri; 1320 p; 1321 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) { 1322 struct route_info *ri = (struct route_info *)p; 1323 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1324 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT && 1325 ri->prefix_len == 0) 1326 continue; 1327 #endif 1328 if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen) 1329 continue; 1330 rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3, 1331 &ipv6_hdr(skb)->saddr); 1332 } 1333 } 1334 #endif 1335 1336 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1337 /* skip link-specific ndopts from interior routers */ 1338 if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) 1339 goto out; 1340 #endif 1341 1342 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) { 1343 struct nd_opt_hdr *p; 1344 for (p = ndopts.nd_opts_pi; 1345 p; 1346 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) { 1347 addrconf_prefix_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3); 1348 } 1349 } 1350 1351 if (ndopts.nd_opts_mtu) { 1352 __be32 n; 1353 u32 mtu; 1354 1355 memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); 1356 mtu = ntohl(n); 1357 1358 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { 1359 ND_PRINTK2(KERN_WARNING 1360 "ICMPv6 RA: invalid mtu: %d\n", 1361 mtu); 1362 } else if (in6_dev->cnf.mtu6 != mtu) { 1363 in6_dev->cnf.mtu6 = mtu; 1364 1365 if (rt) 1366 rt->dst.metrics[RTAX_MTU-1] = mtu; 1367 1368 rt6_mtu_change(skb->dev, mtu); 1369 } 1370 } 1371 1372 if (ndopts.nd_useropts) { 1373 struct nd_opt_hdr *p; 1374 for (p = ndopts.nd_useropts; 1375 p; 1376 p = ndisc_next_useropt(p, ndopts.nd_useropts_end)) { 1377 ndisc_ra_useropt(skb, p); 1378 } 1379 } 1380 1381 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { 1382 ND_PRINTK2(KERN_WARNING 1383 "ICMPv6 RA: invalid RA options"); 1384 } 1385 out: 1386 if (rt) 1387 dst_release(&rt->dst); 1388 else if (neigh) 1389 neigh_release(neigh); 1390 in6_dev_put(in6_dev); 1391 } 1392 1393 static void ndisc_redirect_rcv(struct sk_buff *skb) 1394 { 1395 struct inet6_dev *in6_dev; 1396 struct icmp6hdr *icmph; 1397 struct in6_addr *dest; 1398 struct in6_addr *target; /* new first hop to destination */ 1399 struct neighbour *neigh; 1400 int on_link = 0; 1401 struct ndisc_options ndopts; 1402 int optlen; 1403 u8 *lladdr = NULL; 1404 1405 #ifdef CONFIG_IPV6_NDISC_NODETYPE 1406 switch (skb->ndisc_nodetype) { 1407 case NDISC_NODETYPE_HOST: 1408 case NDISC_NODETYPE_NODEFAULT: 1409 ND_PRINTK2(KERN_WARNING 1410 "ICMPv6 Redirect: from host or unauthorized router\n"); 1411 return; 1412 } 1413 #endif 1414 1415 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1416 ND_PRINTK2(KERN_WARNING 1417 "ICMPv6 Redirect: source address is not link-local.\n"); 1418 return; 1419 } 1420 1421 optlen = skb->tail - skb->transport_header; 1422 optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr); 1423 1424 if (optlen < 0) { 1425 ND_PRINTK2(KERN_WARNING 1426 "ICMPv6 Redirect: packet too short\n"); 1427 return; 1428 } 1429 1430 icmph = icmp6_hdr(skb); 1431 target = (struct in6_addr *) (icmph + 1); 1432 dest = target + 1; 1433 1434 if (ipv6_addr_is_multicast(dest)) { 1435 ND_PRINTK2(KERN_WARNING 1436 "ICMPv6 Redirect: destination address is multicast.\n"); 1437 return; 1438 } 1439 1440 if (ipv6_addr_equal(dest, target)) { 1441 on_link = 1; 1442 } else if (ipv6_addr_type(target) != 1443 (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1444 ND_PRINTK2(KERN_WARNING 1445 "ICMPv6 Redirect: target address is not link-local unicast.\n"); 1446 return; 1447 } 1448 1449 in6_dev = in6_dev_get(skb->dev); 1450 if (!in6_dev) 1451 return; 1452 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) { 1453 in6_dev_put(in6_dev); 1454 return; 1455 } 1456 1457 /* RFC2461 8.1: 1458 * The IP source address of the Redirect MUST be the same as the current 1459 * first-hop router for the specified ICMP Destination Address. 1460 */ 1461 1462 if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) { 1463 ND_PRINTK2(KERN_WARNING 1464 "ICMPv6 Redirect: invalid ND options\n"); 1465 in6_dev_put(in6_dev); 1466 return; 1467 } 1468 if (ndopts.nd_opts_tgt_lladdr) { 1469 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, 1470 skb->dev); 1471 if (!lladdr) { 1472 ND_PRINTK2(KERN_WARNING 1473 "ICMPv6 Redirect: invalid link-layer address length\n"); 1474 in6_dev_put(in6_dev); 1475 return; 1476 } 1477 } 1478 1479 neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1); 1480 if (neigh) { 1481 rt6_redirect(dest, &ipv6_hdr(skb)->daddr, 1482 &ipv6_hdr(skb)->saddr, neigh, lladdr, 1483 on_link); 1484 neigh_release(neigh); 1485 } 1486 in6_dev_put(in6_dev); 1487 } 1488 1489 void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh, 1490 const struct in6_addr *target) 1491 { 1492 struct net_device *dev = skb->dev; 1493 struct net *net = dev_net(dev); 1494 struct sock *sk = net->ipv6.ndisc_sk; 1495 int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr); 1496 struct sk_buff *buff; 1497 struct icmp6hdr *icmph; 1498 struct in6_addr saddr_buf; 1499 struct in6_addr *addrp; 1500 struct rt6_info *rt; 1501 struct dst_entry *dst; 1502 struct inet6_dev *idev; 1503 struct flowi fl; 1504 u8 *opt; 1505 int rd_len; 1506 int err; 1507 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL; 1508 1509 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) { 1510 ND_PRINTK2(KERN_WARNING 1511 "ICMPv6 Redirect: no link-local address on %s\n", 1512 dev->name); 1513 return; 1514 } 1515 1516 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) && 1517 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1518 ND_PRINTK2(KERN_WARNING 1519 "ICMPv6 Redirect: target address is not link-local unicast.\n"); 1520 return; 1521 } 1522 1523 icmpv6_flow_init(sk, &fl, NDISC_REDIRECT, 1524 &saddr_buf, &ipv6_hdr(skb)->saddr, dev->ifindex); 1525 1526 dst = ip6_route_output(net, NULL, &fl); 1527 if (dst == NULL) 1528 return; 1529 1530 err = xfrm_lookup(net, &dst, &fl, NULL, 0); 1531 if (err) 1532 return; 1533 1534 rt = (struct rt6_info *) dst; 1535 1536 if (rt->rt6i_flags & RTF_GATEWAY) { 1537 ND_PRINTK2(KERN_WARNING 1538 "ICMPv6 Redirect: destination is not a neighbour.\n"); 1539 goto release; 1540 } 1541 if (!xrlim_allow(dst, 1*HZ)) 1542 goto release; 1543 1544 if (dev->addr_len) { 1545 read_lock_bh(&neigh->lock); 1546 if (neigh->nud_state & NUD_VALID) { 1547 memcpy(ha_buf, neigh->ha, dev->addr_len); 1548 read_unlock_bh(&neigh->lock); 1549 ha = ha_buf; 1550 len += ndisc_opt_addr_space(dev); 1551 } else 1552 read_unlock_bh(&neigh->lock); 1553 } 1554 1555 rd_len = min_t(unsigned int, 1556 IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8); 1557 rd_len &= ~0x7; 1558 len += rd_len; 1559 1560 buff = sock_alloc_send_skb(sk, 1561 (MAX_HEADER + sizeof(struct ipv6hdr) + 1562 len + LL_ALLOCATED_SPACE(dev)), 1563 1, &err); 1564 if (buff == NULL) { 1565 ND_PRINTK0(KERN_ERR 1566 "ICMPv6 Redirect: %s() failed to allocate an skb, err=%d.\n", 1567 __func__, err); 1568 goto release; 1569 } 1570 1571 skb_reserve(buff, LL_RESERVED_SPACE(dev)); 1572 ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr, 1573 IPPROTO_ICMPV6, len); 1574 1575 skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data); 1576 skb_put(buff, len); 1577 icmph = icmp6_hdr(buff); 1578 1579 memset(icmph, 0, sizeof(struct icmp6hdr)); 1580 icmph->icmp6_type = NDISC_REDIRECT; 1581 1582 /* 1583 * copy target and destination addresses 1584 */ 1585 1586 addrp = (struct in6_addr *)(icmph + 1); 1587 ipv6_addr_copy(addrp, target); 1588 addrp++; 1589 ipv6_addr_copy(addrp, &ipv6_hdr(skb)->daddr); 1590 1591 opt = (u8*) (addrp + 1); 1592 1593 /* 1594 * include target_address option 1595 */ 1596 1597 if (ha) 1598 opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha, 1599 dev->addr_len, dev->type); 1600 1601 /* 1602 * build redirect option and copy skb over to the new packet. 1603 */ 1604 1605 memset(opt, 0, 8); 1606 *(opt++) = ND_OPT_REDIRECT_HDR; 1607 *(opt++) = (rd_len >> 3); 1608 opt += 6; 1609 1610 memcpy(opt, ipv6_hdr(skb), rd_len - 8); 1611 1612 icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr, 1613 len, IPPROTO_ICMPV6, 1614 csum_partial(icmph, len, 0)); 1615 1616 skb_dst_set(buff, dst); 1617 idev = in6_dev_get(dst->dev); 1618 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len); 1619 err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, buff, NULL, dst->dev, 1620 dst_output); 1621 if (!err) { 1622 ICMP6MSGOUT_INC_STATS(net, idev, NDISC_REDIRECT); 1623 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 1624 } 1625 1626 if (likely(idev != NULL)) 1627 in6_dev_put(idev); 1628 return; 1629 1630 release: 1631 dst_release(dst); 1632 } 1633 1634 static void pndisc_redo(struct sk_buff *skb) 1635 { 1636 ndisc_recv_ns(skb); 1637 kfree_skb(skb); 1638 } 1639 1640 int ndisc_rcv(struct sk_buff *skb) 1641 { 1642 struct nd_msg *msg; 1643 1644 if (!pskb_may_pull(skb, skb->len)) 1645 return 0; 1646 1647 msg = (struct nd_msg *)skb_transport_header(skb); 1648 1649 __skb_push(skb, skb->data - skb_transport_header(skb)); 1650 1651 if (ipv6_hdr(skb)->hop_limit != 255) { 1652 ND_PRINTK2(KERN_WARNING 1653 "ICMPv6 NDISC: invalid hop-limit: %d\n", 1654 ipv6_hdr(skb)->hop_limit); 1655 return 0; 1656 } 1657 1658 if (msg->icmph.icmp6_code != 0) { 1659 ND_PRINTK2(KERN_WARNING 1660 "ICMPv6 NDISC: invalid ICMPv6 code: %d\n", 1661 msg->icmph.icmp6_code); 1662 return 0; 1663 } 1664 1665 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 1666 1667 switch (msg->icmph.icmp6_type) { 1668 case NDISC_NEIGHBOUR_SOLICITATION: 1669 ndisc_recv_ns(skb); 1670 break; 1671 1672 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1673 ndisc_recv_na(skb); 1674 break; 1675 1676 case NDISC_ROUTER_SOLICITATION: 1677 ndisc_recv_rs(skb); 1678 break; 1679 1680 case NDISC_ROUTER_ADVERTISEMENT: 1681 ndisc_router_discovery(skb); 1682 break; 1683 1684 case NDISC_REDIRECT: 1685 ndisc_redirect_rcv(skb); 1686 break; 1687 } 1688 1689 return 0; 1690 } 1691 1692 static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1693 { 1694 struct net_device *dev = ptr; 1695 struct net *net = dev_net(dev); 1696 1697 switch (event) { 1698 case NETDEV_CHANGEADDR: 1699 neigh_changeaddr(&nd_tbl, dev); 1700 fib6_run_gc(~0UL, net); 1701 break; 1702 case NETDEV_DOWN: 1703 neigh_ifdown(&nd_tbl, dev); 1704 fib6_run_gc(~0UL, net); 1705 break; 1706 default: 1707 break; 1708 } 1709 1710 return NOTIFY_DONE; 1711 } 1712 1713 static struct notifier_block ndisc_netdev_notifier = { 1714 .notifier_call = ndisc_netdev_event, 1715 }; 1716 1717 #ifdef CONFIG_SYSCTL 1718 static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl, 1719 const char *func, const char *dev_name) 1720 { 1721 static char warncomm[TASK_COMM_LEN]; 1722 static int warned; 1723 if (strcmp(warncomm, current->comm) && warned < 5) { 1724 strcpy(warncomm, current->comm); 1725 printk(KERN_WARNING 1726 "process `%s' is using deprecated sysctl (%s) " 1727 "net.ipv6.neigh.%s.%s; " 1728 "Use net.ipv6.neigh.%s.%s_ms " 1729 "instead.\n", 1730 warncomm, func, 1731 dev_name, ctl->procname, 1732 dev_name, ctl->procname); 1733 warned++; 1734 } 1735 } 1736 1737 int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos) 1738 { 1739 struct net_device *dev = ctl->extra1; 1740 struct inet6_dev *idev; 1741 int ret; 1742 1743 if ((strcmp(ctl->procname, "retrans_time") == 0) || 1744 (strcmp(ctl->procname, "base_reachable_time") == 0)) 1745 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default"); 1746 1747 if (strcmp(ctl->procname, "retrans_time") == 0) 1748 ret = proc_dointvec(ctl, write, buffer, lenp, ppos); 1749 1750 else if (strcmp(ctl->procname, "base_reachable_time") == 0) 1751 ret = proc_dointvec_jiffies(ctl, write, 1752 buffer, lenp, ppos); 1753 1754 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) || 1755 (strcmp(ctl->procname, "base_reachable_time_ms") == 0)) 1756 ret = proc_dointvec_ms_jiffies(ctl, write, 1757 buffer, lenp, ppos); 1758 else 1759 ret = -1; 1760 1761 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) { 1762 if (ctl->data == &idev->nd_parms->base_reachable_time) 1763 idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time); 1764 idev->tstamp = jiffies; 1765 inet6_ifinfo_notify(RTM_NEWLINK, idev); 1766 in6_dev_put(idev); 1767 } 1768 return ret; 1769 } 1770 1771 1772 #endif 1773 1774 static int __net_init ndisc_net_init(struct net *net) 1775 { 1776 struct ipv6_pinfo *np; 1777 struct sock *sk; 1778 int err; 1779 1780 err = inet_ctl_sock_create(&sk, PF_INET6, 1781 SOCK_RAW, IPPROTO_ICMPV6, net); 1782 if (err < 0) { 1783 ND_PRINTK0(KERN_ERR 1784 "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n", 1785 err); 1786 return err; 1787 } 1788 1789 net->ipv6.ndisc_sk = sk; 1790 1791 np = inet6_sk(sk); 1792 np->hop_limit = 255; 1793 /* Do not loopback ndisc messages */ 1794 np->mc_loop = 0; 1795 1796 return 0; 1797 } 1798 1799 static void __net_exit ndisc_net_exit(struct net *net) 1800 { 1801 inet_ctl_sock_destroy(net->ipv6.ndisc_sk); 1802 } 1803 1804 static struct pernet_operations ndisc_net_ops = { 1805 .init = ndisc_net_init, 1806 .exit = ndisc_net_exit, 1807 }; 1808 1809 int __init ndisc_init(void) 1810 { 1811 int err; 1812 1813 err = register_pernet_subsys(&ndisc_net_ops); 1814 if (err) 1815 return err; 1816 /* 1817 * Initialize the neighbour table 1818 */ 1819 neigh_table_init(&nd_tbl); 1820 1821 #ifdef CONFIG_SYSCTL 1822 err = neigh_sysctl_register(NULL, &nd_tbl.parms, "ipv6", 1823 &ndisc_ifinfo_sysctl_change); 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