1 /* 2 * Linux INET6 implementation 3 * FIB front-end. 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 */ 13 14 /* Changes: 15 * 16 * YOSHIFUJI Hideaki @USAGI 17 * reworked default router selection. 18 * - respect outgoing interface 19 * - select from (probably) reachable routers (i.e. 20 * routers in REACHABLE, STALE, DELAY or PROBE states). 21 * - always select the same router if it is (probably) 22 * reachable. otherwise, round-robin the list. 23 * Ville Nuorvala 24 * Fixed routing subtrees. 25 */ 26 27 #include <linux/capability.h> 28 #include <linux/errno.h> 29 #include <linux/export.h> 30 #include <linux/types.h> 31 #include <linux/times.h> 32 #include <linux/socket.h> 33 #include <linux/sockios.h> 34 #include <linux/net.h> 35 #include <linux/route.h> 36 #include <linux/netdevice.h> 37 #include <linux/in6.h> 38 #include <linux/mroute6.h> 39 #include <linux/init.h> 40 #include <linux/if_arp.h> 41 #include <linux/proc_fs.h> 42 #include <linux/seq_file.h> 43 #include <linux/nsproxy.h> 44 #include <linux/slab.h> 45 #include <net/net_namespace.h> 46 #include <net/snmp.h> 47 #include <net/ipv6.h> 48 #include <net/ip6_fib.h> 49 #include <net/ip6_route.h> 50 #include <net/ndisc.h> 51 #include <net/addrconf.h> 52 #include <net/tcp.h> 53 #include <linux/rtnetlink.h> 54 #include <net/dst.h> 55 #include <net/xfrm.h> 56 #include <net/netevent.h> 57 #include <net/netlink.h> 58 59 #include <asm/uaccess.h> 60 61 #ifdef CONFIG_SYSCTL 62 #include <linux/sysctl.h> 63 #endif 64 65 static struct rt6_info *ip6_rt_copy(const struct rt6_info *ort, 66 const struct in6_addr *dest); 67 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie); 68 static unsigned int ip6_default_advmss(const struct dst_entry *dst); 69 static unsigned int ip6_mtu(const struct dst_entry *dst); 70 static struct dst_entry *ip6_negative_advice(struct dst_entry *); 71 static void ip6_dst_destroy(struct dst_entry *); 72 static void ip6_dst_ifdown(struct dst_entry *, 73 struct net_device *dev, int how); 74 static int ip6_dst_gc(struct dst_ops *ops); 75 76 static int ip6_pkt_discard(struct sk_buff *skb); 77 static int ip6_pkt_discard_out(struct sk_buff *skb); 78 static void ip6_link_failure(struct sk_buff *skb); 79 static void ip6_rt_update_pmtu(struct dst_entry *dst, u32 mtu); 80 81 #ifdef CONFIG_IPV6_ROUTE_INFO 82 static struct rt6_info *rt6_add_route_info(struct net *net, 83 const struct in6_addr *prefix, int prefixlen, 84 const struct in6_addr *gwaddr, int ifindex, 85 unsigned pref); 86 static struct rt6_info *rt6_get_route_info(struct net *net, 87 const struct in6_addr *prefix, int prefixlen, 88 const struct in6_addr *gwaddr, int ifindex); 89 #endif 90 91 static u32 *ipv6_cow_metrics(struct dst_entry *dst, unsigned long old) 92 { 93 struct rt6_info *rt = (struct rt6_info *) dst; 94 struct inet_peer *peer; 95 u32 *p = NULL; 96 97 if (!(rt->dst.flags & DST_HOST)) 98 return NULL; 99 100 if (!rt->rt6i_peer) 101 rt6_bind_peer(rt, 1); 102 103 peer = rt->rt6i_peer; 104 if (peer) { 105 u32 *old_p = __DST_METRICS_PTR(old); 106 unsigned long prev, new; 107 108 p = peer->metrics; 109 if (inet_metrics_new(peer)) 110 memcpy(p, old_p, sizeof(u32) * RTAX_MAX); 111 112 new = (unsigned long) p; 113 prev = cmpxchg(&dst->_metrics, old, new); 114 115 if (prev != old) { 116 p = __DST_METRICS_PTR(prev); 117 if (prev & DST_METRICS_READ_ONLY) 118 p = NULL; 119 } 120 } 121 return p; 122 } 123 124 static inline const void *choose_neigh_daddr(struct rt6_info *rt, const void *daddr) 125 { 126 struct in6_addr *p = &rt->rt6i_gateway; 127 128 if (!ipv6_addr_any(p)) 129 return (const void *) p; 130 return daddr; 131 } 132 133 static struct neighbour *ip6_neigh_lookup(const struct dst_entry *dst, const void *daddr) 134 { 135 struct rt6_info *rt = (struct rt6_info *) dst; 136 struct neighbour *n; 137 138 daddr = choose_neigh_daddr(rt, daddr); 139 n = __ipv6_neigh_lookup(&nd_tbl, dst->dev, daddr); 140 if (n) 141 return n; 142 return neigh_create(&nd_tbl, daddr, dst->dev); 143 } 144 145 static int rt6_bind_neighbour(struct rt6_info *rt, struct net_device *dev) 146 { 147 struct neighbour *n = __ipv6_neigh_lookup(&nd_tbl, dev, &rt->rt6i_gateway); 148 if (!n) { 149 n = neigh_create(&nd_tbl, &rt->rt6i_gateway, dev); 150 if (IS_ERR(n)) 151 return PTR_ERR(n); 152 } 153 dst_set_neighbour(&rt->dst, n); 154 155 return 0; 156 } 157 158 static struct dst_ops ip6_dst_ops_template = { 159 .family = AF_INET6, 160 .protocol = cpu_to_be16(ETH_P_IPV6), 161 .gc = ip6_dst_gc, 162 .gc_thresh = 1024, 163 .check = ip6_dst_check, 164 .default_advmss = ip6_default_advmss, 165 .mtu = ip6_mtu, 166 .cow_metrics = ipv6_cow_metrics, 167 .destroy = ip6_dst_destroy, 168 .ifdown = ip6_dst_ifdown, 169 .negative_advice = ip6_negative_advice, 170 .link_failure = ip6_link_failure, 171 .update_pmtu = ip6_rt_update_pmtu, 172 .local_out = __ip6_local_out, 173 .neigh_lookup = ip6_neigh_lookup, 174 }; 175 176 static unsigned int ip6_blackhole_mtu(const struct dst_entry *dst) 177 { 178 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 179 180 return mtu ? : dst->dev->mtu; 181 } 182 183 static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu) 184 { 185 } 186 187 static u32 *ip6_rt_blackhole_cow_metrics(struct dst_entry *dst, 188 unsigned long old) 189 { 190 return NULL; 191 } 192 193 static struct dst_ops ip6_dst_blackhole_ops = { 194 .family = AF_INET6, 195 .protocol = cpu_to_be16(ETH_P_IPV6), 196 .destroy = ip6_dst_destroy, 197 .check = ip6_dst_check, 198 .mtu = ip6_blackhole_mtu, 199 .default_advmss = ip6_default_advmss, 200 .update_pmtu = ip6_rt_blackhole_update_pmtu, 201 .cow_metrics = ip6_rt_blackhole_cow_metrics, 202 .neigh_lookup = ip6_neigh_lookup, 203 }; 204 205 static const u32 ip6_template_metrics[RTAX_MAX] = { 206 [RTAX_HOPLIMIT - 1] = 255, 207 }; 208 209 static struct rt6_info ip6_null_entry_template = { 210 .dst = { 211 .__refcnt = ATOMIC_INIT(1), 212 .__use = 1, 213 .obsolete = -1, 214 .error = -ENETUNREACH, 215 .input = ip6_pkt_discard, 216 .output = ip6_pkt_discard_out, 217 }, 218 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), 219 .rt6i_protocol = RTPROT_KERNEL, 220 .rt6i_metric = ~(u32) 0, 221 .rt6i_ref = ATOMIC_INIT(1), 222 }; 223 224 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 225 226 static int ip6_pkt_prohibit(struct sk_buff *skb); 227 static int ip6_pkt_prohibit_out(struct sk_buff *skb); 228 229 static struct rt6_info ip6_prohibit_entry_template = { 230 .dst = { 231 .__refcnt = ATOMIC_INIT(1), 232 .__use = 1, 233 .obsolete = -1, 234 .error = -EACCES, 235 .input = ip6_pkt_prohibit, 236 .output = ip6_pkt_prohibit_out, 237 }, 238 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), 239 .rt6i_protocol = RTPROT_KERNEL, 240 .rt6i_metric = ~(u32) 0, 241 .rt6i_ref = ATOMIC_INIT(1), 242 }; 243 244 static struct rt6_info ip6_blk_hole_entry_template = { 245 .dst = { 246 .__refcnt = ATOMIC_INIT(1), 247 .__use = 1, 248 .obsolete = -1, 249 .error = -EINVAL, 250 .input = dst_discard, 251 .output = dst_discard, 252 }, 253 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), 254 .rt6i_protocol = RTPROT_KERNEL, 255 .rt6i_metric = ~(u32) 0, 256 .rt6i_ref = ATOMIC_INIT(1), 257 }; 258 259 #endif 260 261 /* allocate dst with ip6_dst_ops */ 262 static inline struct rt6_info *ip6_dst_alloc(struct dst_ops *ops, 263 struct net_device *dev, 264 int flags) 265 { 266 struct rt6_info *rt = dst_alloc(ops, dev, 0, 0, flags); 267 268 if (rt) 269 memset(&rt->rt6i_table, 0, 270 sizeof(*rt) - sizeof(struct dst_entry)); 271 272 return rt; 273 } 274 275 static void ip6_dst_destroy(struct dst_entry *dst) 276 { 277 struct rt6_info *rt = (struct rt6_info *)dst; 278 struct inet6_dev *idev = rt->rt6i_idev; 279 struct inet_peer *peer = rt->rt6i_peer; 280 281 if (!(rt->dst.flags & DST_HOST)) 282 dst_destroy_metrics_generic(dst); 283 284 if (idev) { 285 rt->rt6i_idev = NULL; 286 in6_dev_put(idev); 287 } 288 if (peer) { 289 rt->rt6i_peer = NULL; 290 inet_putpeer(peer); 291 } 292 } 293 294 static atomic_t __rt6_peer_genid = ATOMIC_INIT(0); 295 296 static u32 rt6_peer_genid(void) 297 { 298 return atomic_read(&__rt6_peer_genid); 299 } 300 301 void rt6_bind_peer(struct rt6_info *rt, int create) 302 { 303 struct inet_peer *peer; 304 305 peer = inet_getpeer_v6(&rt->rt6i_dst.addr, create); 306 if (peer && cmpxchg(&rt->rt6i_peer, NULL, peer) != NULL) 307 inet_putpeer(peer); 308 else 309 rt->rt6i_peer_genid = rt6_peer_genid(); 310 } 311 312 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 313 int how) 314 { 315 struct rt6_info *rt = (struct rt6_info *)dst; 316 struct inet6_dev *idev = rt->rt6i_idev; 317 struct net_device *loopback_dev = 318 dev_net(dev)->loopback_dev; 319 320 if (dev != loopback_dev && idev && idev->dev == dev) { 321 struct inet6_dev *loopback_idev = 322 in6_dev_get(loopback_dev); 323 if (loopback_idev) { 324 rt->rt6i_idev = loopback_idev; 325 in6_dev_put(idev); 326 } 327 } 328 } 329 330 static __inline__ int rt6_check_expired(const struct rt6_info *rt) 331 { 332 return (rt->rt6i_flags & RTF_EXPIRES) && 333 time_after(jiffies, rt->dst.expires); 334 } 335 336 static inline int rt6_need_strict(const struct in6_addr *daddr) 337 { 338 return ipv6_addr_type(daddr) & 339 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK); 340 } 341 342 /* 343 * Route lookup. Any table->tb6_lock is implied. 344 */ 345 346 static inline struct rt6_info *rt6_device_match(struct net *net, 347 struct rt6_info *rt, 348 const struct in6_addr *saddr, 349 int oif, 350 int flags) 351 { 352 struct rt6_info *local = NULL; 353 struct rt6_info *sprt; 354 355 if (!oif && ipv6_addr_any(saddr)) 356 goto out; 357 358 for (sprt = rt; sprt; sprt = sprt->dst.rt6_next) { 359 struct net_device *dev = sprt->dst.dev; 360 361 if (oif) { 362 if (dev->ifindex == oif) 363 return sprt; 364 if (dev->flags & IFF_LOOPBACK) { 365 if (!sprt->rt6i_idev || 366 sprt->rt6i_idev->dev->ifindex != oif) { 367 if (flags & RT6_LOOKUP_F_IFACE && oif) 368 continue; 369 if (local && (!oif || 370 local->rt6i_idev->dev->ifindex == oif)) 371 continue; 372 } 373 local = sprt; 374 } 375 } else { 376 if (ipv6_chk_addr(net, saddr, dev, 377 flags & RT6_LOOKUP_F_IFACE)) 378 return sprt; 379 } 380 } 381 382 if (oif) { 383 if (local) 384 return local; 385 386 if (flags & RT6_LOOKUP_F_IFACE) 387 return net->ipv6.ip6_null_entry; 388 } 389 out: 390 return rt; 391 } 392 393 #ifdef CONFIG_IPV6_ROUTER_PREF 394 static void rt6_probe(struct rt6_info *rt) 395 { 396 struct neighbour *neigh; 397 /* 398 * Okay, this does not seem to be appropriate 399 * for now, however, we need to check if it 400 * is really so; aka Router Reachability Probing. 401 * 402 * Router Reachability Probe MUST be rate-limited 403 * to no more than one per minute. 404 */ 405 rcu_read_lock(); 406 neigh = rt ? dst_get_neighbour_noref(&rt->dst) : NULL; 407 if (!neigh || (neigh->nud_state & NUD_VALID)) 408 goto out; 409 read_lock_bh(&neigh->lock); 410 if (!(neigh->nud_state & NUD_VALID) && 411 time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) { 412 struct in6_addr mcaddr; 413 struct in6_addr *target; 414 415 neigh->updated = jiffies; 416 read_unlock_bh(&neigh->lock); 417 418 target = (struct in6_addr *)&neigh->primary_key; 419 addrconf_addr_solict_mult(target, &mcaddr); 420 ndisc_send_ns(rt->dst.dev, NULL, target, &mcaddr, NULL); 421 } else { 422 read_unlock_bh(&neigh->lock); 423 } 424 out: 425 rcu_read_unlock(); 426 } 427 #else 428 static inline void rt6_probe(struct rt6_info *rt) 429 { 430 } 431 #endif 432 433 /* 434 * Default Router Selection (RFC 2461 6.3.6) 435 */ 436 static inline int rt6_check_dev(struct rt6_info *rt, int oif) 437 { 438 struct net_device *dev = rt->dst.dev; 439 if (!oif || dev->ifindex == oif) 440 return 2; 441 if ((dev->flags & IFF_LOOPBACK) && 442 rt->rt6i_idev && rt->rt6i_idev->dev->ifindex == oif) 443 return 1; 444 return 0; 445 } 446 447 static inline int rt6_check_neigh(struct rt6_info *rt) 448 { 449 struct neighbour *neigh; 450 int m; 451 452 rcu_read_lock(); 453 neigh = dst_get_neighbour_noref(&rt->dst); 454 if (rt->rt6i_flags & RTF_NONEXTHOP || 455 !(rt->rt6i_flags & RTF_GATEWAY)) 456 m = 1; 457 else if (neigh) { 458 read_lock_bh(&neigh->lock); 459 if (neigh->nud_state & NUD_VALID) 460 m = 2; 461 #ifdef CONFIG_IPV6_ROUTER_PREF 462 else if (neigh->nud_state & NUD_FAILED) 463 m = 0; 464 #endif 465 else 466 m = 1; 467 read_unlock_bh(&neigh->lock); 468 } else 469 m = 0; 470 rcu_read_unlock(); 471 return m; 472 } 473 474 static int rt6_score_route(struct rt6_info *rt, int oif, 475 int strict) 476 { 477 int m, n; 478 479 m = rt6_check_dev(rt, oif); 480 if (!m && (strict & RT6_LOOKUP_F_IFACE)) 481 return -1; 482 #ifdef CONFIG_IPV6_ROUTER_PREF 483 m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(rt->rt6i_flags)) << 2; 484 #endif 485 n = rt6_check_neigh(rt); 486 if (!n && (strict & RT6_LOOKUP_F_REACHABLE)) 487 return -1; 488 return m; 489 } 490 491 static struct rt6_info *find_match(struct rt6_info *rt, int oif, int strict, 492 int *mpri, struct rt6_info *match) 493 { 494 int m; 495 496 if (rt6_check_expired(rt)) 497 goto out; 498 499 m = rt6_score_route(rt, oif, strict); 500 if (m < 0) 501 goto out; 502 503 if (m > *mpri) { 504 if (strict & RT6_LOOKUP_F_REACHABLE) 505 rt6_probe(match); 506 *mpri = m; 507 match = rt; 508 } else if (strict & RT6_LOOKUP_F_REACHABLE) { 509 rt6_probe(rt); 510 } 511 512 out: 513 return match; 514 } 515 516 static struct rt6_info *find_rr_leaf(struct fib6_node *fn, 517 struct rt6_info *rr_head, 518 u32 metric, int oif, int strict) 519 { 520 struct rt6_info *rt, *match; 521 int mpri = -1; 522 523 match = NULL; 524 for (rt = rr_head; rt && rt->rt6i_metric == metric; 525 rt = rt->dst.rt6_next) 526 match = find_match(rt, oif, strict, &mpri, match); 527 for (rt = fn->leaf; rt && rt != rr_head && rt->rt6i_metric == metric; 528 rt = rt->dst.rt6_next) 529 match = find_match(rt, oif, strict, &mpri, match); 530 531 return match; 532 } 533 534 static struct rt6_info *rt6_select(struct fib6_node *fn, int oif, int strict) 535 { 536 struct rt6_info *match, *rt0; 537 struct net *net; 538 539 rt0 = fn->rr_ptr; 540 if (!rt0) 541 fn->rr_ptr = rt0 = fn->leaf; 542 543 match = find_rr_leaf(fn, rt0, rt0->rt6i_metric, oif, strict); 544 545 if (!match && 546 (strict & RT6_LOOKUP_F_REACHABLE)) { 547 struct rt6_info *next = rt0->dst.rt6_next; 548 549 /* no entries matched; do round-robin */ 550 if (!next || next->rt6i_metric != rt0->rt6i_metric) 551 next = fn->leaf; 552 553 if (next != rt0) 554 fn->rr_ptr = next; 555 } 556 557 net = dev_net(rt0->dst.dev); 558 return match ? match : net->ipv6.ip6_null_entry; 559 } 560 561 #ifdef CONFIG_IPV6_ROUTE_INFO 562 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, 563 const struct in6_addr *gwaddr) 564 { 565 struct net *net = dev_net(dev); 566 struct route_info *rinfo = (struct route_info *) opt; 567 struct in6_addr prefix_buf, *prefix; 568 unsigned int pref; 569 unsigned long lifetime; 570 struct rt6_info *rt; 571 572 if (len < sizeof(struct route_info)) { 573 return -EINVAL; 574 } 575 576 /* Sanity check for prefix_len and length */ 577 if (rinfo->length > 3) { 578 return -EINVAL; 579 } else if (rinfo->prefix_len > 128) { 580 return -EINVAL; 581 } else if (rinfo->prefix_len > 64) { 582 if (rinfo->length < 2) { 583 return -EINVAL; 584 } 585 } else if (rinfo->prefix_len > 0) { 586 if (rinfo->length < 1) { 587 return -EINVAL; 588 } 589 } 590 591 pref = rinfo->route_pref; 592 if (pref == ICMPV6_ROUTER_PREF_INVALID) 593 return -EINVAL; 594 595 lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ); 596 597 if (rinfo->length == 3) 598 prefix = (struct in6_addr *)rinfo->prefix; 599 else { 600 /* this function is safe */ 601 ipv6_addr_prefix(&prefix_buf, 602 (struct in6_addr *)rinfo->prefix, 603 rinfo->prefix_len); 604 prefix = &prefix_buf; 605 } 606 607 rt = rt6_get_route_info(net, prefix, rinfo->prefix_len, gwaddr, 608 dev->ifindex); 609 610 if (rt && !lifetime) { 611 ip6_del_rt(rt); 612 rt = NULL; 613 } 614 615 if (!rt && lifetime) 616 rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr, dev->ifindex, 617 pref); 618 else if (rt) 619 rt->rt6i_flags = RTF_ROUTEINFO | 620 (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 621 622 if (rt) { 623 if (!addrconf_finite_timeout(lifetime)) { 624 rt->rt6i_flags &= ~RTF_EXPIRES; 625 } else { 626 rt->dst.expires = jiffies + HZ * lifetime; 627 rt->rt6i_flags |= RTF_EXPIRES; 628 } 629 dst_release(&rt->dst); 630 } 631 return 0; 632 } 633 #endif 634 635 #define BACKTRACK(__net, saddr) \ 636 do { \ 637 if (rt == __net->ipv6.ip6_null_entry) { \ 638 struct fib6_node *pn; \ 639 while (1) { \ 640 if (fn->fn_flags & RTN_TL_ROOT) \ 641 goto out; \ 642 pn = fn->parent; \ 643 if (FIB6_SUBTREE(pn) && FIB6_SUBTREE(pn) != fn) \ 644 fn = fib6_lookup(FIB6_SUBTREE(pn), NULL, saddr); \ 645 else \ 646 fn = pn; \ 647 if (fn->fn_flags & RTN_RTINFO) \ 648 goto restart; \ 649 } \ 650 } \ 651 } while (0) 652 653 static struct rt6_info *ip6_pol_route_lookup(struct net *net, 654 struct fib6_table *table, 655 struct flowi6 *fl6, int flags) 656 { 657 struct fib6_node *fn; 658 struct rt6_info *rt; 659 660 read_lock_bh(&table->tb6_lock); 661 fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); 662 restart: 663 rt = fn->leaf; 664 rt = rt6_device_match(net, rt, &fl6->saddr, fl6->flowi6_oif, flags); 665 BACKTRACK(net, &fl6->saddr); 666 out: 667 dst_use(&rt->dst, jiffies); 668 read_unlock_bh(&table->tb6_lock); 669 return rt; 670 671 } 672 673 struct dst_entry * ip6_route_lookup(struct net *net, struct flowi6 *fl6, 674 int flags) 675 { 676 return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_lookup); 677 } 678 EXPORT_SYMBOL_GPL(ip6_route_lookup); 679 680 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr, 681 const struct in6_addr *saddr, int oif, int strict) 682 { 683 struct flowi6 fl6 = { 684 .flowi6_oif = oif, 685 .daddr = *daddr, 686 }; 687 struct dst_entry *dst; 688 int flags = strict ? RT6_LOOKUP_F_IFACE : 0; 689 690 if (saddr) { 691 memcpy(&fl6.saddr, saddr, sizeof(*saddr)); 692 flags |= RT6_LOOKUP_F_HAS_SADDR; 693 } 694 695 dst = fib6_rule_lookup(net, &fl6, flags, ip6_pol_route_lookup); 696 if (dst->error == 0) 697 return (struct rt6_info *) dst; 698 699 dst_release(dst); 700 701 return NULL; 702 } 703 704 EXPORT_SYMBOL(rt6_lookup); 705 706 /* ip6_ins_rt is called with FREE table->tb6_lock. 707 It takes new route entry, the addition fails by any reason the 708 route is freed. In any case, if caller does not hold it, it may 709 be destroyed. 710 */ 711 712 static int __ip6_ins_rt(struct rt6_info *rt, struct nl_info *info) 713 { 714 int err; 715 struct fib6_table *table; 716 717 table = rt->rt6i_table; 718 write_lock_bh(&table->tb6_lock); 719 err = fib6_add(&table->tb6_root, rt, info); 720 write_unlock_bh(&table->tb6_lock); 721 722 return err; 723 } 724 725 int ip6_ins_rt(struct rt6_info *rt) 726 { 727 struct nl_info info = { 728 .nl_net = dev_net(rt->dst.dev), 729 }; 730 return __ip6_ins_rt(rt, &info); 731 } 732 733 static struct rt6_info *rt6_alloc_cow(const struct rt6_info *ort, 734 const struct in6_addr *daddr, 735 const struct in6_addr *saddr) 736 { 737 struct rt6_info *rt; 738 739 /* 740 * Clone the route. 741 */ 742 743 rt = ip6_rt_copy(ort, daddr); 744 745 if (rt) { 746 int attempts = !in_softirq(); 747 748 if (!(rt->rt6i_flags & RTF_GATEWAY)) { 749 if (ort->rt6i_dst.plen != 128 && 750 ipv6_addr_equal(&ort->rt6i_dst.addr, daddr)) 751 rt->rt6i_flags |= RTF_ANYCAST; 752 rt->rt6i_gateway = *daddr; 753 } 754 755 rt->rt6i_flags |= RTF_CACHE; 756 757 #ifdef CONFIG_IPV6_SUBTREES 758 if (rt->rt6i_src.plen && saddr) { 759 rt->rt6i_src.addr = *saddr; 760 rt->rt6i_src.plen = 128; 761 } 762 #endif 763 764 retry: 765 if (rt6_bind_neighbour(rt, rt->dst.dev)) { 766 struct net *net = dev_net(rt->dst.dev); 767 int saved_rt_min_interval = 768 net->ipv6.sysctl.ip6_rt_gc_min_interval; 769 int saved_rt_elasticity = 770 net->ipv6.sysctl.ip6_rt_gc_elasticity; 771 772 if (attempts-- > 0) { 773 net->ipv6.sysctl.ip6_rt_gc_elasticity = 1; 774 net->ipv6.sysctl.ip6_rt_gc_min_interval = 0; 775 776 ip6_dst_gc(&net->ipv6.ip6_dst_ops); 777 778 net->ipv6.sysctl.ip6_rt_gc_elasticity = 779 saved_rt_elasticity; 780 net->ipv6.sysctl.ip6_rt_gc_min_interval = 781 saved_rt_min_interval; 782 goto retry; 783 } 784 785 if (net_ratelimit()) 786 printk(KERN_WARNING 787 "ipv6: Neighbour table overflow.\n"); 788 dst_free(&rt->dst); 789 return NULL; 790 } 791 } 792 793 return rt; 794 } 795 796 static struct rt6_info *rt6_alloc_clone(struct rt6_info *ort, 797 const struct in6_addr *daddr) 798 { 799 struct rt6_info *rt = ip6_rt_copy(ort, daddr); 800 801 if (rt) { 802 rt->rt6i_flags |= RTF_CACHE; 803 dst_set_neighbour(&rt->dst, neigh_clone(dst_get_neighbour_noref_raw(&ort->dst))); 804 } 805 return rt; 806 } 807 808 static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, int oif, 809 struct flowi6 *fl6, int flags) 810 { 811 struct fib6_node *fn; 812 struct rt6_info *rt, *nrt; 813 int strict = 0; 814 int attempts = 3; 815 int err; 816 int reachable = net->ipv6.devconf_all->forwarding ? 0 : RT6_LOOKUP_F_REACHABLE; 817 818 strict |= flags & RT6_LOOKUP_F_IFACE; 819 820 relookup: 821 read_lock_bh(&table->tb6_lock); 822 823 restart_2: 824 fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); 825 826 restart: 827 rt = rt6_select(fn, oif, strict | reachable); 828 829 BACKTRACK(net, &fl6->saddr); 830 if (rt == net->ipv6.ip6_null_entry || 831 rt->rt6i_flags & RTF_CACHE) 832 goto out; 833 834 dst_hold(&rt->dst); 835 read_unlock_bh(&table->tb6_lock); 836 837 if (!dst_get_neighbour_noref_raw(&rt->dst) && !(rt->rt6i_flags & RTF_NONEXTHOP)) 838 nrt = rt6_alloc_cow(rt, &fl6->daddr, &fl6->saddr); 839 else if (!(rt->dst.flags & DST_HOST)) 840 nrt = rt6_alloc_clone(rt, &fl6->daddr); 841 else 842 goto out2; 843 844 dst_release(&rt->dst); 845 rt = nrt ? : net->ipv6.ip6_null_entry; 846 847 dst_hold(&rt->dst); 848 if (nrt) { 849 err = ip6_ins_rt(nrt); 850 if (!err) 851 goto out2; 852 } 853 854 if (--attempts <= 0) 855 goto out2; 856 857 /* 858 * Race condition! In the gap, when table->tb6_lock was 859 * released someone could insert this route. Relookup. 860 */ 861 dst_release(&rt->dst); 862 goto relookup; 863 864 out: 865 if (reachable) { 866 reachable = 0; 867 goto restart_2; 868 } 869 dst_hold(&rt->dst); 870 read_unlock_bh(&table->tb6_lock); 871 out2: 872 rt->dst.lastuse = jiffies; 873 rt->dst.__use++; 874 875 return rt; 876 } 877 878 static struct rt6_info *ip6_pol_route_input(struct net *net, struct fib6_table *table, 879 struct flowi6 *fl6, int flags) 880 { 881 return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, flags); 882 } 883 884 void ip6_route_input(struct sk_buff *skb) 885 { 886 const struct ipv6hdr *iph = ipv6_hdr(skb); 887 struct net *net = dev_net(skb->dev); 888 int flags = RT6_LOOKUP_F_HAS_SADDR; 889 struct flowi6 fl6 = { 890 .flowi6_iif = skb->dev->ifindex, 891 .daddr = iph->daddr, 892 .saddr = iph->saddr, 893 .flowlabel = (* (__be32 *) iph) & IPV6_FLOWINFO_MASK, 894 .flowi6_mark = skb->mark, 895 .flowi6_proto = iph->nexthdr, 896 }; 897 898 if (rt6_need_strict(&iph->daddr) && skb->dev->type != ARPHRD_PIMREG) 899 flags |= RT6_LOOKUP_F_IFACE; 900 901 skb_dst_set(skb, fib6_rule_lookup(net, &fl6, flags, ip6_pol_route_input)); 902 } 903 904 static struct rt6_info *ip6_pol_route_output(struct net *net, struct fib6_table *table, 905 struct flowi6 *fl6, int flags) 906 { 907 return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, flags); 908 } 909 910 struct dst_entry * ip6_route_output(struct net *net, const struct sock *sk, 911 struct flowi6 *fl6) 912 { 913 int flags = 0; 914 915 if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr)) 916 flags |= RT6_LOOKUP_F_IFACE; 917 918 if (!ipv6_addr_any(&fl6->saddr)) 919 flags |= RT6_LOOKUP_F_HAS_SADDR; 920 else if (sk) 921 flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs); 922 923 return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_output); 924 } 925 926 EXPORT_SYMBOL(ip6_route_output); 927 928 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig) 929 { 930 struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig; 931 struct dst_entry *new = NULL; 932 933 rt = dst_alloc(&ip6_dst_blackhole_ops, ort->dst.dev, 1, 0, 0); 934 if (rt) { 935 memset(&rt->rt6i_table, 0, sizeof(*rt) - sizeof(struct dst_entry)); 936 937 new = &rt->dst; 938 939 new->__use = 1; 940 new->input = dst_discard; 941 new->output = dst_discard; 942 943 if (dst_metrics_read_only(&ort->dst)) 944 new->_metrics = ort->dst._metrics; 945 else 946 dst_copy_metrics(new, &ort->dst); 947 rt->rt6i_idev = ort->rt6i_idev; 948 if (rt->rt6i_idev) 949 in6_dev_hold(rt->rt6i_idev); 950 rt->dst.expires = 0; 951 952 rt->rt6i_gateway = ort->rt6i_gateway; 953 rt->rt6i_flags = ort->rt6i_flags & ~RTF_EXPIRES; 954 rt->rt6i_metric = 0; 955 956 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key)); 957 #ifdef CONFIG_IPV6_SUBTREES 958 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key)); 959 #endif 960 961 dst_free(new); 962 } 963 964 dst_release(dst_orig); 965 return new ? new : ERR_PTR(-ENOMEM); 966 } 967 968 /* 969 * Destination cache support functions 970 */ 971 972 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie) 973 { 974 struct rt6_info *rt; 975 976 rt = (struct rt6_info *) dst; 977 978 if (rt->rt6i_node && (rt->rt6i_node->fn_sernum == cookie)) { 979 if (rt->rt6i_peer_genid != rt6_peer_genid()) { 980 if (!rt->rt6i_peer) 981 rt6_bind_peer(rt, 0); 982 rt->rt6i_peer_genid = rt6_peer_genid(); 983 } 984 return dst; 985 } 986 return NULL; 987 } 988 989 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst) 990 { 991 struct rt6_info *rt = (struct rt6_info *) dst; 992 993 if (rt) { 994 if (rt->rt6i_flags & RTF_CACHE) { 995 if (rt6_check_expired(rt)) { 996 ip6_del_rt(rt); 997 dst = NULL; 998 } 999 } else { 1000 dst_release(dst); 1001 dst = NULL; 1002 } 1003 } 1004 return dst; 1005 } 1006 1007 static void ip6_link_failure(struct sk_buff *skb) 1008 { 1009 struct rt6_info *rt; 1010 1011 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0); 1012 1013 rt = (struct rt6_info *) skb_dst(skb); 1014 if (rt) { 1015 if (rt->rt6i_flags & RTF_CACHE) { 1016 dst_set_expires(&rt->dst, 0); 1017 rt->rt6i_flags |= RTF_EXPIRES; 1018 } else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT)) 1019 rt->rt6i_node->fn_sernum = -1; 1020 } 1021 } 1022 1023 static void ip6_rt_update_pmtu(struct dst_entry *dst, u32 mtu) 1024 { 1025 struct rt6_info *rt6 = (struct rt6_info*)dst; 1026 1027 if (mtu < dst_mtu(dst) && rt6->rt6i_dst.plen == 128) { 1028 rt6->rt6i_flags |= RTF_MODIFIED; 1029 if (mtu < IPV6_MIN_MTU) { 1030 u32 features = dst_metric(dst, RTAX_FEATURES); 1031 mtu = IPV6_MIN_MTU; 1032 features |= RTAX_FEATURE_ALLFRAG; 1033 dst_metric_set(dst, RTAX_FEATURES, features); 1034 } 1035 dst_metric_set(dst, RTAX_MTU, mtu); 1036 } 1037 } 1038 1039 static unsigned int ip6_default_advmss(const struct dst_entry *dst) 1040 { 1041 struct net_device *dev = dst->dev; 1042 unsigned int mtu = dst_mtu(dst); 1043 struct net *net = dev_net(dev); 1044 1045 mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr); 1046 1047 if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss) 1048 mtu = net->ipv6.sysctl.ip6_rt_min_advmss; 1049 1050 /* 1051 * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and 1052 * corresponding MSS is IPV6_MAXPLEN - tcp_header_size. 1053 * IPV6_MAXPLEN is also valid and means: "any MSS, 1054 * rely only on pmtu discovery" 1055 */ 1056 if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr)) 1057 mtu = IPV6_MAXPLEN; 1058 return mtu; 1059 } 1060 1061 static unsigned int ip6_mtu(const struct dst_entry *dst) 1062 { 1063 struct inet6_dev *idev; 1064 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 1065 1066 if (mtu) 1067 return mtu; 1068 1069 mtu = IPV6_MIN_MTU; 1070 1071 rcu_read_lock(); 1072 idev = __in6_dev_get(dst->dev); 1073 if (idev) 1074 mtu = idev->cnf.mtu6; 1075 rcu_read_unlock(); 1076 1077 return mtu; 1078 } 1079 1080 static struct dst_entry *icmp6_dst_gc_list; 1081 static DEFINE_SPINLOCK(icmp6_dst_lock); 1082 1083 struct dst_entry *icmp6_dst_alloc(struct net_device *dev, 1084 struct neighbour *neigh, 1085 struct flowi6 *fl6) 1086 { 1087 struct dst_entry *dst; 1088 struct rt6_info *rt; 1089 struct inet6_dev *idev = in6_dev_get(dev); 1090 struct net *net = dev_net(dev); 1091 1092 if (unlikely(!idev)) 1093 return ERR_PTR(-ENODEV); 1094 1095 rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops, dev, 0); 1096 if (unlikely(!rt)) { 1097 in6_dev_put(idev); 1098 dst = ERR_PTR(-ENOMEM); 1099 goto out; 1100 } 1101 1102 if (neigh) 1103 neigh_hold(neigh); 1104 else { 1105 neigh = ip6_neigh_lookup(&rt->dst, &fl6->daddr); 1106 if (IS_ERR(neigh)) { 1107 in6_dev_put(idev); 1108 dst_free(&rt->dst); 1109 return ERR_CAST(neigh); 1110 } 1111 } 1112 1113 rt->dst.flags |= DST_HOST; 1114 rt->dst.output = ip6_output; 1115 dst_set_neighbour(&rt->dst, neigh); 1116 atomic_set(&rt->dst.__refcnt, 1); 1117 rt->rt6i_dst.addr = fl6->daddr; 1118 rt->rt6i_dst.plen = 128; 1119 rt->rt6i_idev = idev; 1120 dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 255); 1121 1122 spin_lock_bh(&icmp6_dst_lock); 1123 rt->dst.next = icmp6_dst_gc_list; 1124 icmp6_dst_gc_list = &rt->dst; 1125 spin_unlock_bh(&icmp6_dst_lock); 1126 1127 fib6_force_start_gc(net); 1128 1129 dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0); 1130 1131 out: 1132 return dst; 1133 } 1134 1135 int icmp6_dst_gc(void) 1136 { 1137 struct dst_entry *dst, **pprev; 1138 int more = 0; 1139 1140 spin_lock_bh(&icmp6_dst_lock); 1141 pprev = &icmp6_dst_gc_list; 1142 1143 while ((dst = *pprev) != NULL) { 1144 if (!atomic_read(&dst->__refcnt)) { 1145 *pprev = dst->next; 1146 dst_free(dst); 1147 } else { 1148 pprev = &dst->next; 1149 ++more; 1150 } 1151 } 1152 1153 spin_unlock_bh(&icmp6_dst_lock); 1154 1155 return more; 1156 } 1157 1158 static void icmp6_clean_all(int (*func)(struct rt6_info *rt, void *arg), 1159 void *arg) 1160 { 1161 struct dst_entry *dst, **pprev; 1162 1163 spin_lock_bh(&icmp6_dst_lock); 1164 pprev = &icmp6_dst_gc_list; 1165 while ((dst = *pprev) != NULL) { 1166 struct rt6_info *rt = (struct rt6_info *) dst; 1167 if (func(rt, arg)) { 1168 *pprev = dst->next; 1169 dst_free(dst); 1170 } else { 1171 pprev = &dst->next; 1172 } 1173 } 1174 spin_unlock_bh(&icmp6_dst_lock); 1175 } 1176 1177 static int ip6_dst_gc(struct dst_ops *ops) 1178 { 1179 unsigned long now = jiffies; 1180 struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops); 1181 int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval; 1182 int rt_max_size = net->ipv6.sysctl.ip6_rt_max_size; 1183 int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity; 1184 int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout; 1185 unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc; 1186 int entries; 1187 1188 entries = dst_entries_get_fast(ops); 1189 if (time_after(rt_last_gc + rt_min_interval, now) && 1190 entries <= rt_max_size) 1191 goto out; 1192 1193 net->ipv6.ip6_rt_gc_expire++; 1194 fib6_run_gc(net->ipv6.ip6_rt_gc_expire, net); 1195 net->ipv6.ip6_rt_last_gc = now; 1196 entries = dst_entries_get_slow(ops); 1197 if (entries < ops->gc_thresh) 1198 net->ipv6.ip6_rt_gc_expire = rt_gc_timeout>>1; 1199 out: 1200 net->ipv6.ip6_rt_gc_expire -= net->ipv6.ip6_rt_gc_expire>>rt_elasticity; 1201 return entries > rt_max_size; 1202 } 1203 1204 /* Clean host part of a prefix. Not necessary in radix tree, 1205 but results in cleaner routing tables. 1206 1207 Remove it only when all the things will work! 1208 */ 1209 1210 int ip6_dst_hoplimit(struct dst_entry *dst) 1211 { 1212 int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); 1213 if (hoplimit == 0) { 1214 struct net_device *dev = dst->dev; 1215 struct inet6_dev *idev; 1216 1217 rcu_read_lock(); 1218 idev = __in6_dev_get(dev); 1219 if (idev) 1220 hoplimit = idev->cnf.hop_limit; 1221 else 1222 hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit; 1223 rcu_read_unlock(); 1224 } 1225 return hoplimit; 1226 } 1227 EXPORT_SYMBOL(ip6_dst_hoplimit); 1228 1229 /* 1230 * 1231 */ 1232 1233 int ip6_route_add(struct fib6_config *cfg) 1234 { 1235 int err; 1236 struct net *net = cfg->fc_nlinfo.nl_net; 1237 struct rt6_info *rt = NULL; 1238 struct net_device *dev = NULL; 1239 struct inet6_dev *idev = NULL; 1240 struct fib6_table *table; 1241 int addr_type; 1242 1243 if (cfg->fc_dst_len > 128 || cfg->fc_src_len > 128) 1244 return -EINVAL; 1245 #ifndef CONFIG_IPV6_SUBTREES 1246 if (cfg->fc_src_len) 1247 return -EINVAL; 1248 #endif 1249 if (cfg->fc_ifindex) { 1250 err = -ENODEV; 1251 dev = dev_get_by_index(net, cfg->fc_ifindex); 1252 if (!dev) 1253 goto out; 1254 idev = in6_dev_get(dev); 1255 if (!idev) 1256 goto out; 1257 } 1258 1259 if (cfg->fc_metric == 0) 1260 cfg->fc_metric = IP6_RT_PRIO_USER; 1261 1262 err = -ENOBUFS; 1263 if (cfg->fc_nlinfo.nlh && 1264 !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) { 1265 table = fib6_get_table(net, cfg->fc_table); 1266 if (!table) { 1267 printk(KERN_WARNING "IPv6: NLM_F_CREATE should be specified when creating new route\n"); 1268 table = fib6_new_table(net, cfg->fc_table); 1269 } 1270 } else { 1271 table = fib6_new_table(net, cfg->fc_table); 1272 } 1273 1274 if (!table) 1275 goto out; 1276 1277 rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops, NULL, DST_NOCOUNT); 1278 1279 if (!rt) { 1280 err = -ENOMEM; 1281 goto out; 1282 } 1283 1284 rt->dst.obsolete = -1; 1285 rt->dst.expires = (cfg->fc_flags & RTF_EXPIRES) ? 1286 jiffies + clock_t_to_jiffies(cfg->fc_expires) : 1287 0; 1288 1289 if (cfg->fc_protocol == RTPROT_UNSPEC) 1290 cfg->fc_protocol = RTPROT_BOOT; 1291 rt->rt6i_protocol = cfg->fc_protocol; 1292 1293 addr_type = ipv6_addr_type(&cfg->fc_dst); 1294 1295 if (addr_type & IPV6_ADDR_MULTICAST) 1296 rt->dst.input = ip6_mc_input; 1297 else if (cfg->fc_flags & RTF_LOCAL) 1298 rt->dst.input = ip6_input; 1299 else 1300 rt->dst.input = ip6_forward; 1301 1302 rt->dst.output = ip6_output; 1303 1304 ipv6_addr_prefix(&rt->rt6i_dst.addr, &cfg->fc_dst, cfg->fc_dst_len); 1305 rt->rt6i_dst.plen = cfg->fc_dst_len; 1306 if (rt->rt6i_dst.plen == 128) 1307 rt->dst.flags |= DST_HOST; 1308 1309 if (!(rt->dst.flags & DST_HOST) && cfg->fc_mx) { 1310 u32 *metrics = kzalloc(sizeof(u32) * RTAX_MAX, GFP_KERNEL); 1311 if (!metrics) { 1312 err = -ENOMEM; 1313 goto out; 1314 } 1315 dst_init_metrics(&rt->dst, metrics, 0); 1316 } 1317 #ifdef CONFIG_IPV6_SUBTREES 1318 ipv6_addr_prefix(&rt->rt6i_src.addr, &cfg->fc_src, cfg->fc_src_len); 1319 rt->rt6i_src.plen = cfg->fc_src_len; 1320 #endif 1321 1322 rt->rt6i_metric = cfg->fc_metric; 1323 1324 /* We cannot add true routes via loopback here, 1325 they would result in kernel looping; promote them to reject routes 1326 */ 1327 if ((cfg->fc_flags & RTF_REJECT) || 1328 (dev && (dev->flags & IFF_LOOPBACK) && 1329 !(addr_type & IPV6_ADDR_LOOPBACK) && 1330 !(cfg->fc_flags & RTF_LOCAL))) { 1331 /* hold loopback dev/idev if we haven't done so. */ 1332 if (dev != net->loopback_dev) { 1333 if (dev) { 1334 dev_put(dev); 1335 in6_dev_put(idev); 1336 } 1337 dev = net->loopback_dev; 1338 dev_hold(dev); 1339 idev = in6_dev_get(dev); 1340 if (!idev) { 1341 err = -ENODEV; 1342 goto out; 1343 } 1344 } 1345 rt->dst.output = ip6_pkt_discard_out; 1346 rt->dst.input = ip6_pkt_discard; 1347 rt->dst.error = -ENETUNREACH; 1348 rt->rt6i_flags = RTF_REJECT|RTF_NONEXTHOP; 1349 goto install_route; 1350 } 1351 1352 if (cfg->fc_flags & RTF_GATEWAY) { 1353 const struct in6_addr *gw_addr; 1354 int gwa_type; 1355 1356 gw_addr = &cfg->fc_gateway; 1357 rt->rt6i_gateway = *gw_addr; 1358 gwa_type = ipv6_addr_type(gw_addr); 1359 1360 if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) { 1361 struct rt6_info *grt; 1362 1363 /* IPv6 strictly inhibits using not link-local 1364 addresses as nexthop address. 1365 Otherwise, router will not able to send redirects. 1366 It is very good, but in some (rare!) circumstances 1367 (SIT, PtP, NBMA NOARP links) it is handy to allow 1368 some exceptions. --ANK 1369 */ 1370 err = -EINVAL; 1371 if (!(gwa_type & IPV6_ADDR_UNICAST)) 1372 goto out; 1373 1374 grt = rt6_lookup(net, gw_addr, NULL, cfg->fc_ifindex, 1); 1375 1376 err = -EHOSTUNREACH; 1377 if (!grt) 1378 goto out; 1379 if (dev) { 1380 if (dev != grt->dst.dev) { 1381 dst_release(&grt->dst); 1382 goto out; 1383 } 1384 } else { 1385 dev = grt->dst.dev; 1386 idev = grt->rt6i_idev; 1387 dev_hold(dev); 1388 in6_dev_hold(grt->rt6i_idev); 1389 } 1390 if (!(grt->rt6i_flags & RTF_GATEWAY)) 1391 err = 0; 1392 dst_release(&grt->dst); 1393 1394 if (err) 1395 goto out; 1396 } 1397 err = -EINVAL; 1398 if (!dev || (dev->flags & IFF_LOOPBACK)) 1399 goto out; 1400 } 1401 1402 err = -ENODEV; 1403 if (!dev) 1404 goto out; 1405 1406 if (!ipv6_addr_any(&cfg->fc_prefsrc)) { 1407 if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) { 1408 err = -EINVAL; 1409 goto out; 1410 } 1411 rt->rt6i_prefsrc.addr = cfg->fc_prefsrc; 1412 rt->rt6i_prefsrc.plen = 128; 1413 } else 1414 rt->rt6i_prefsrc.plen = 0; 1415 1416 if (cfg->fc_flags & (RTF_GATEWAY | RTF_NONEXTHOP)) { 1417 err = rt6_bind_neighbour(rt, dev); 1418 if (err) 1419 goto out; 1420 } 1421 1422 rt->rt6i_flags = cfg->fc_flags; 1423 1424 install_route: 1425 if (cfg->fc_mx) { 1426 struct nlattr *nla; 1427 int remaining; 1428 1429 nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) { 1430 int type = nla_type(nla); 1431 1432 if (type) { 1433 if (type > RTAX_MAX) { 1434 err = -EINVAL; 1435 goto out; 1436 } 1437 1438 dst_metric_set(&rt->dst, type, nla_get_u32(nla)); 1439 } 1440 } 1441 } 1442 1443 rt->dst.dev = dev; 1444 rt->rt6i_idev = idev; 1445 rt->rt6i_table = table; 1446 1447 cfg->fc_nlinfo.nl_net = dev_net(dev); 1448 1449 return __ip6_ins_rt(rt, &cfg->fc_nlinfo); 1450 1451 out: 1452 if (dev) 1453 dev_put(dev); 1454 if (idev) 1455 in6_dev_put(idev); 1456 if (rt) 1457 dst_free(&rt->dst); 1458 return err; 1459 } 1460 1461 static int __ip6_del_rt(struct rt6_info *rt, struct nl_info *info) 1462 { 1463 int err; 1464 struct fib6_table *table; 1465 struct net *net = dev_net(rt->dst.dev); 1466 1467 if (rt == net->ipv6.ip6_null_entry) 1468 return -ENOENT; 1469 1470 table = rt->rt6i_table; 1471 write_lock_bh(&table->tb6_lock); 1472 1473 err = fib6_del(rt, info); 1474 dst_release(&rt->dst); 1475 1476 write_unlock_bh(&table->tb6_lock); 1477 1478 return err; 1479 } 1480 1481 int ip6_del_rt(struct rt6_info *rt) 1482 { 1483 struct nl_info info = { 1484 .nl_net = dev_net(rt->dst.dev), 1485 }; 1486 return __ip6_del_rt(rt, &info); 1487 } 1488 1489 static int ip6_route_del(struct fib6_config *cfg) 1490 { 1491 struct fib6_table *table; 1492 struct fib6_node *fn; 1493 struct rt6_info *rt; 1494 int err = -ESRCH; 1495 1496 table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table); 1497 if (!table) 1498 return err; 1499 1500 read_lock_bh(&table->tb6_lock); 1501 1502 fn = fib6_locate(&table->tb6_root, 1503 &cfg->fc_dst, cfg->fc_dst_len, 1504 &cfg->fc_src, cfg->fc_src_len); 1505 1506 if (fn) { 1507 for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) { 1508 if (cfg->fc_ifindex && 1509 (!rt->dst.dev || 1510 rt->dst.dev->ifindex != cfg->fc_ifindex)) 1511 continue; 1512 if (cfg->fc_flags & RTF_GATEWAY && 1513 !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway)) 1514 continue; 1515 if (cfg->fc_metric && cfg->fc_metric != rt->rt6i_metric) 1516 continue; 1517 dst_hold(&rt->dst); 1518 read_unlock_bh(&table->tb6_lock); 1519 1520 return __ip6_del_rt(rt, &cfg->fc_nlinfo); 1521 } 1522 } 1523 read_unlock_bh(&table->tb6_lock); 1524 1525 return err; 1526 } 1527 1528 /* 1529 * Handle redirects 1530 */ 1531 struct ip6rd_flowi { 1532 struct flowi6 fl6; 1533 struct in6_addr gateway; 1534 }; 1535 1536 static struct rt6_info *__ip6_route_redirect(struct net *net, 1537 struct fib6_table *table, 1538 struct flowi6 *fl6, 1539 int flags) 1540 { 1541 struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6; 1542 struct rt6_info *rt; 1543 struct fib6_node *fn; 1544 1545 /* 1546 * Get the "current" route for this destination and 1547 * check if the redirect has come from approriate router. 1548 * 1549 * RFC 2461 specifies that redirects should only be 1550 * accepted if they come from the nexthop to the target. 1551 * Due to the way the routes are chosen, this notion 1552 * is a bit fuzzy and one might need to check all possible 1553 * routes. 1554 */ 1555 1556 read_lock_bh(&table->tb6_lock); 1557 fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); 1558 restart: 1559 for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) { 1560 /* 1561 * Current route is on-link; redirect is always invalid. 1562 * 1563 * Seems, previous statement is not true. It could 1564 * be node, which looks for us as on-link (f.e. proxy ndisc) 1565 * But then router serving it might decide, that we should 1566 * know truth 8)8) --ANK (980726). 1567 */ 1568 if (rt6_check_expired(rt)) 1569 continue; 1570 if (!(rt->rt6i_flags & RTF_GATEWAY)) 1571 continue; 1572 if (fl6->flowi6_oif != rt->dst.dev->ifindex) 1573 continue; 1574 if (!ipv6_addr_equal(&rdfl->gateway, &rt->rt6i_gateway)) 1575 continue; 1576 break; 1577 } 1578 1579 if (!rt) 1580 rt = net->ipv6.ip6_null_entry; 1581 BACKTRACK(net, &fl6->saddr); 1582 out: 1583 dst_hold(&rt->dst); 1584 1585 read_unlock_bh(&table->tb6_lock); 1586 1587 return rt; 1588 }; 1589 1590 static struct rt6_info *ip6_route_redirect(const struct in6_addr *dest, 1591 const struct in6_addr *src, 1592 const struct in6_addr *gateway, 1593 struct net_device *dev) 1594 { 1595 int flags = RT6_LOOKUP_F_HAS_SADDR; 1596 struct net *net = dev_net(dev); 1597 struct ip6rd_flowi rdfl = { 1598 .fl6 = { 1599 .flowi6_oif = dev->ifindex, 1600 .daddr = *dest, 1601 .saddr = *src, 1602 }, 1603 }; 1604 1605 rdfl.gateway = *gateway; 1606 1607 if (rt6_need_strict(dest)) 1608 flags |= RT6_LOOKUP_F_IFACE; 1609 1610 return (struct rt6_info *)fib6_rule_lookup(net, &rdfl.fl6, 1611 flags, __ip6_route_redirect); 1612 } 1613 1614 void rt6_redirect(const struct in6_addr *dest, const struct in6_addr *src, 1615 const struct in6_addr *saddr, 1616 struct neighbour *neigh, u8 *lladdr, int on_link) 1617 { 1618 struct rt6_info *rt, *nrt = NULL; 1619 struct netevent_redirect netevent; 1620 struct net *net = dev_net(neigh->dev); 1621 1622 rt = ip6_route_redirect(dest, src, saddr, neigh->dev); 1623 1624 if (rt == net->ipv6.ip6_null_entry) { 1625 if (net_ratelimit()) 1626 printk(KERN_DEBUG "rt6_redirect: source isn't a valid nexthop " 1627 "for redirect target\n"); 1628 goto out; 1629 } 1630 1631 /* 1632 * We have finally decided to accept it. 1633 */ 1634 1635 neigh_update(neigh, lladdr, NUD_STALE, 1636 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1637 NEIGH_UPDATE_F_OVERRIDE| 1638 (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1639 NEIGH_UPDATE_F_ISROUTER)) 1640 ); 1641 1642 /* 1643 * Redirect received -> path was valid. 1644 * Look, redirects are sent only in response to data packets, 1645 * so that this nexthop apparently is reachable. --ANK 1646 */ 1647 dst_confirm(&rt->dst); 1648 1649 /* Duplicate redirect: silently ignore. */ 1650 if (neigh == dst_get_neighbour_noref_raw(&rt->dst)) 1651 goto out; 1652 1653 nrt = ip6_rt_copy(rt, dest); 1654 if (!nrt) 1655 goto out; 1656 1657 nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE; 1658 if (on_link) 1659 nrt->rt6i_flags &= ~RTF_GATEWAY; 1660 1661 nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key; 1662 dst_set_neighbour(&nrt->dst, neigh_clone(neigh)); 1663 1664 if (ip6_ins_rt(nrt)) 1665 goto out; 1666 1667 netevent.old = &rt->dst; 1668 netevent.new = &nrt->dst; 1669 call_netevent_notifiers(NETEVENT_REDIRECT, &netevent); 1670 1671 if (rt->rt6i_flags & RTF_CACHE) { 1672 ip6_del_rt(rt); 1673 return; 1674 } 1675 1676 out: 1677 dst_release(&rt->dst); 1678 } 1679 1680 /* 1681 * Handle ICMP "packet too big" messages 1682 * i.e. Path MTU discovery 1683 */ 1684 1685 static void rt6_do_pmtu_disc(const struct in6_addr *daddr, const struct in6_addr *saddr, 1686 struct net *net, u32 pmtu, int ifindex) 1687 { 1688 struct rt6_info *rt, *nrt; 1689 int allfrag = 0; 1690 again: 1691 rt = rt6_lookup(net, daddr, saddr, ifindex, 0); 1692 if (!rt) 1693 return; 1694 1695 if (rt6_check_expired(rt)) { 1696 ip6_del_rt(rt); 1697 goto again; 1698 } 1699 1700 if (pmtu >= dst_mtu(&rt->dst)) 1701 goto out; 1702 1703 if (pmtu < IPV6_MIN_MTU) { 1704 /* 1705 * According to RFC2460, PMTU is set to the IPv6 Minimum Link 1706 * MTU (1280) and a fragment header should always be included 1707 * after a node receiving Too Big message reporting PMTU is 1708 * less than the IPv6 Minimum Link MTU. 1709 */ 1710 pmtu = IPV6_MIN_MTU; 1711 allfrag = 1; 1712 } 1713 1714 /* New mtu received -> path was valid. 1715 They are sent only in response to data packets, 1716 so that this nexthop apparently is reachable. --ANK 1717 */ 1718 dst_confirm(&rt->dst); 1719 1720 /* Host route. If it is static, it would be better 1721 not to override it, but add new one, so that 1722 when cache entry will expire old pmtu 1723 would return automatically. 1724 */ 1725 if (rt->rt6i_flags & RTF_CACHE) { 1726 dst_metric_set(&rt->dst, RTAX_MTU, pmtu); 1727 if (allfrag) { 1728 u32 features = dst_metric(&rt->dst, RTAX_FEATURES); 1729 features |= RTAX_FEATURE_ALLFRAG; 1730 dst_metric_set(&rt->dst, RTAX_FEATURES, features); 1731 } 1732 dst_set_expires(&rt->dst, net->ipv6.sysctl.ip6_rt_mtu_expires); 1733 rt->rt6i_flags |= RTF_MODIFIED|RTF_EXPIRES; 1734 goto out; 1735 } 1736 1737 /* Network route. 1738 Two cases are possible: 1739 1. It is connected route. Action: COW 1740 2. It is gatewayed route or NONEXTHOP route. Action: clone it. 1741 */ 1742 if (!dst_get_neighbour_noref_raw(&rt->dst) && !(rt->rt6i_flags & RTF_NONEXTHOP)) 1743 nrt = rt6_alloc_cow(rt, daddr, saddr); 1744 else 1745 nrt = rt6_alloc_clone(rt, daddr); 1746 1747 if (nrt) { 1748 dst_metric_set(&nrt->dst, RTAX_MTU, pmtu); 1749 if (allfrag) { 1750 u32 features = dst_metric(&nrt->dst, RTAX_FEATURES); 1751 features |= RTAX_FEATURE_ALLFRAG; 1752 dst_metric_set(&nrt->dst, RTAX_FEATURES, features); 1753 } 1754 1755 /* According to RFC 1981, detecting PMTU increase shouldn't be 1756 * happened within 5 mins, the recommended timer is 10 mins. 1757 * Here this route expiration time is set to ip6_rt_mtu_expires 1758 * which is 10 mins. After 10 mins the decreased pmtu is expired 1759 * and detecting PMTU increase will be automatically happened. 1760 */ 1761 dst_set_expires(&nrt->dst, net->ipv6.sysctl.ip6_rt_mtu_expires); 1762 nrt->rt6i_flags |= RTF_DYNAMIC|RTF_EXPIRES; 1763 1764 ip6_ins_rt(nrt); 1765 } 1766 out: 1767 dst_release(&rt->dst); 1768 } 1769 1770 void rt6_pmtu_discovery(const struct in6_addr *daddr, const struct in6_addr *saddr, 1771 struct net_device *dev, u32 pmtu) 1772 { 1773 struct net *net = dev_net(dev); 1774 1775 /* 1776 * RFC 1981 states that a node "MUST reduce the size of the packets it 1777 * is sending along the path" that caused the Packet Too Big message. 1778 * Since it's not possible in the general case to determine which 1779 * interface was used to send the original packet, we update the MTU 1780 * on the interface that will be used to send future packets. We also 1781 * update the MTU on the interface that received the Packet Too Big in 1782 * case the original packet was forced out that interface with 1783 * SO_BINDTODEVICE or similar. This is the next best thing to the 1784 * correct behaviour, which would be to update the MTU on all 1785 * interfaces. 1786 */ 1787 rt6_do_pmtu_disc(daddr, saddr, net, pmtu, 0); 1788 rt6_do_pmtu_disc(daddr, saddr, net, pmtu, dev->ifindex); 1789 } 1790 1791 /* 1792 * Misc support functions 1793 */ 1794 1795 static struct rt6_info *ip6_rt_copy(const struct rt6_info *ort, 1796 const struct in6_addr *dest) 1797 { 1798 struct net *net = dev_net(ort->dst.dev); 1799 struct rt6_info *rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops, 1800 ort->dst.dev, 0); 1801 1802 if (rt) { 1803 rt->dst.input = ort->dst.input; 1804 rt->dst.output = ort->dst.output; 1805 rt->dst.flags |= DST_HOST; 1806 1807 rt->rt6i_dst.addr = *dest; 1808 rt->rt6i_dst.plen = 128; 1809 dst_copy_metrics(&rt->dst, &ort->dst); 1810 rt->dst.error = ort->dst.error; 1811 rt->rt6i_idev = ort->rt6i_idev; 1812 if (rt->rt6i_idev) 1813 in6_dev_hold(rt->rt6i_idev); 1814 rt->dst.lastuse = jiffies; 1815 rt->dst.expires = 0; 1816 1817 rt->rt6i_gateway = ort->rt6i_gateway; 1818 rt->rt6i_flags = ort->rt6i_flags & ~RTF_EXPIRES; 1819 rt->rt6i_metric = 0; 1820 1821 #ifdef CONFIG_IPV6_SUBTREES 1822 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key)); 1823 #endif 1824 memcpy(&rt->rt6i_prefsrc, &ort->rt6i_prefsrc, sizeof(struct rt6key)); 1825 rt->rt6i_table = ort->rt6i_table; 1826 } 1827 return rt; 1828 } 1829 1830 #ifdef CONFIG_IPV6_ROUTE_INFO 1831 static struct rt6_info *rt6_get_route_info(struct net *net, 1832 const struct in6_addr *prefix, int prefixlen, 1833 const struct in6_addr *gwaddr, int ifindex) 1834 { 1835 struct fib6_node *fn; 1836 struct rt6_info *rt = NULL; 1837 struct fib6_table *table; 1838 1839 table = fib6_get_table(net, RT6_TABLE_INFO); 1840 if (!table) 1841 return NULL; 1842 1843 write_lock_bh(&table->tb6_lock); 1844 fn = fib6_locate(&table->tb6_root, prefix ,prefixlen, NULL, 0); 1845 if (!fn) 1846 goto out; 1847 1848 for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) { 1849 if (rt->dst.dev->ifindex != ifindex) 1850 continue; 1851 if ((rt->rt6i_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY)) 1852 continue; 1853 if (!ipv6_addr_equal(&rt->rt6i_gateway, gwaddr)) 1854 continue; 1855 dst_hold(&rt->dst); 1856 break; 1857 } 1858 out: 1859 write_unlock_bh(&table->tb6_lock); 1860 return rt; 1861 } 1862 1863 static struct rt6_info *rt6_add_route_info(struct net *net, 1864 const struct in6_addr *prefix, int prefixlen, 1865 const struct in6_addr *gwaddr, int ifindex, 1866 unsigned pref) 1867 { 1868 struct fib6_config cfg = { 1869 .fc_table = RT6_TABLE_INFO, 1870 .fc_metric = IP6_RT_PRIO_USER, 1871 .fc_ifindex = ifindex, 1872 .fc_dst_len = prefixlen, 1873 .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO | 1874 RTF_UP | RTF_PREF(pref), 1875 .fc_nlinfo.pid = 0, 1876 .fc_nlinfo.nlh = NULL, 1877 .fc_nlinfo.nl_net = net, 1878 }; 1879 1880 cfg.fc_dst = *prefix; 1881 cfg.fc_gateway = *gwaddr; 1882 1883 /* We should treat it as a default route if prefix length is 0. */ 1884 if (!prefixlen) 1885 cfg.fc_flags |= RTF_DEFAULT; 1886 1887 ip6_route_add(&cfg); 1888 1889 return rt6_get_route_info(net, prefix, prefixlen, gwaddr, ifindex); 1890 } 1891 #endif 1892 1893 struct rt6_info *rt6_get_dflt_router(const struct in6_addr *addr, struct net_device *dev) 1894 { 1895 struct rt6_info *rt; 1896 struct fib6_table *table; 1897 1898 table = fib6_get_table(dev_net(dev), RT6_TABLE_DFLT); 1899 if (!table) 1900 return NULL; 1901 1902 write_lock_bh(&table->tb6_lock); 1903 for (rt = table->tb6_root.leaf; rt; rt=rt->dst.rt6_next) { 1904 if (dev == rt->dst.dev && 1905 ((rt->rt6i_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) && 1906 ipv6_addr_equal(&rt->rt6i_gateway, addr)) 1907 break; 1908 } 1909 if (rt) 1910 dst_hold(&rt->dst); 1911 write_unlock_bh(&table->tb6_lock); 1912 return rt; 1913 } 1914 1915 struct rt6_info *rt6_add_dflt_router(const struct in6_addr *gwaddr, 1916 struct net_device *dev, 1917 unsigned int pref) 1918 { 1919 struct fib6_config cfg = { 1920 .fc_table = RT6_TABLE_DFLT, 1921 .fc_metric = IP6_RT_PRIO_USER, 1922 .fc_ifindex = dev->ifindex, 1923 .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT | 1924 RTF_UP | RTF_EXPIRES | RTF_PREF(pref), 1925 .fc_nlinfo.pid = 0, 1926 .fc_nlinfo.nlh = NULL, 1927 .fc_nlinfo.nl_net = dev_net(dev), 1928 }; 1929 1930 cfg.fc_gateway = *gwaddr; 1931 1932 ip6_route_add(&cfg); 1933 1934 return rt6_get_dflt_router(gwaddr, dev); 1935 } 1936 1937 void rt6_purge_dflt_routers(struct net *net) 1938 { 1939 struct rt6_info *rt; 1940 struct fib6_table *table; 1941 1942 /* NOTE: Keep consistent with rt6_get_dflt_router */ 1943 table = fib6_get_table(net, RT6_TABLE_DFLT); 1944 if (!table) 1945 return; 1946 1947 restart: 1948 read_lock_bh(&table->tb6_lock); 1949 for (rt = table->tb6_root.leaf; rt; rt = rt->dst.rt6_next) { 1950 if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) { 1951 dst_hold(&rt->dst); 1952 read_unlock_bh(&table->tb6_lock); 1953 ip6_del_rt(rt); 1954 goto restart; 1955 } 1956 } 1957 read_unlock_bh(&table->tb6_lock); 1958 } 1959 1960 static void rtmsg_to_fib6_config(struct net *net, 1961 struct in6_rtmsg *rtmsg, 1962 struct fib6_config *cfg) 1963 { 1964 memset(cfg, 0, sizeof(*cfg)); 1965 1966 cfg->fc_table = RT6_TABLE_MAIN; 1967 cfg->fc_ifindex = rtmsg->rtmsg_ifindex; 1968 cfg->fc_metric = rtmsg->rtmsg_metric; 1969 cfg->fc_expires = rtmsg->rtmsg_info; 1970 cfg->fc_dst_len = rtmsg->rtmsg_dst_len; 1971 cfg->fc_src_len = rtmsg->rtmsg_src_len; 1972 cfg->fc_flags = rtmsg->rtmsg_flags; 1973 1974 cfg->fc_nlinfo.nl_net = net; 1975 1976 cfg->fc_dst = rtmsg->rtmsg_dst; 1977 cfg->fc_src = rtmsg->rtmsg_src; 1978 cfg->fc_gateway = rtmsg->rtmsg_gateway; 1979 } 1980 1981 int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg) 1982 { 1983 struct fib6_config cfg; 1984 struct in6_rtmsg rtmsg; 1985 int err; 1986 1987 switch(cmd) { 1988 case SIOCADDRT: /* Add a route */ 1989 case SIOCDELRT: /* Delete a route */ 1990 if (!capable(CAP_NET_ADMIN)) 1991 return -EPERM; 1992 err = copy_from_user(&rtmsg, arg, 1993 sizeof(struct in6_rtmsg)); 1994 if (err) 1995 return -EFAULT; 1996 1997 rtmsg_to_fib6_config(net, &rtmsg, &cfg); 1998 1999 rtnl_lock(); 2000 switch (cmd) { 2001 case SIOCADDRT: 2002 err = ip6_route_add(&cfg); 2003 break; 2004 case SIOCDELRT: 2005 err = ip6_route_del(&cfg); 2006 break; 2007 default: 2008 err = -EINVAL; 2009 } 2010 rtnl_unlock(); 2011 2012 return err; 2013 } 2014 2015 return -EINVAL; 2016 } 2017 2018 /* 2019 * Drop the packet on the floor 2020 */ 2021 2022 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes) 2023 { 2024 int type; 2025 struct dst_entry *dst = skb_dst(skb); 2026 switch (ipstats_mib_noroutes) { 2027 case IPSTATS_MIB_INNOROUTES: 2028 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr); 2029 if (type == IPV6_ADDR_ANY) { 2030 IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst), 2031 IPSTATS_MIB_INADDRERRORS); 2032 break; 2033 } 2034 /* FALLTHROUGH */ 2035 case IPSTATS_MIB_OUTNOROUTES: 2036 IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst), 2037 ipstats_mib_noroutes); 2038 break; 2039 } 2040 icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0); 2041 kfree_skb(skb); 2042 return 0; 2043 } 2044 2045 static int ip6_pkt_discard(struct sk_buff *skb) 2046 { 2047 return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES); 2048 } 2049 2050 static int ip6_pkt_discard_out(struct sk_buff *skb) 2051 { 2052 skb->dev = skb_dst(skb)->dev; 2053 return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES); 2054 } 2055 2056 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2057 2058 static int ip6_pkt_prohibit(struct sk_buff *skb) 2059 { 2060 return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES); 2061 } 2062 2063 static int ip6_pkt_prohibit_out(struct sk_buff *skb) 2064 { 2065 skb->dev = skb_dst(skb)->dev; 2066 return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES); 2067 } 2068 2069 #endif 2070 2071 /* 2072 * Allocate a dst for local (unicast / anycast) address. 2073 */ 2074 2075 struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev, 2076 const struct in6_addr *addr, 2077 bool anycast) 2078 { 2079 struct net *net = dev_net(idev->dev); 2080 struct rt6_info *rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops, 2081 net->loopback_dev, 0); 2082 int err; 2083 2084 if (!rt) { 2085 if (net_ratelimit()) 2086 pr_warning("IPv6: Maximum number of routes reached," 2087 " consider increasing route/max_size.\n"); 2088 return ERR_PTR(-ENOMEM); 2089 } 2090 2091 in6_dev_hold(idev); 2092 2093 rt->dst.flags |= DST_HOST; 2094 rt->dst.input = ip6_input; 2095 rt->dst.output = ip6_output; 2096 rt->rt6i_idev = idev; 2097 rt->dst.obsolete = -1; 2098 2099 rt->rt6i_flags = RTF_UP | RTF_NONEXTHOP; 2100 if (anycast) 2101 rt->rt6i_flags |= RTF_ANYCAST; 2102 else 2103 rt->rt6i_flags |= RTF_LOCAL; 2104 err = rt6_bind_neighbour(rt, rt->dst.dev); 2105 if (err) { 2106 dst_free(&rt->dst); 2107 return ERR_PTR(err); 2108 } 2109 2110 rt->rt6i_dst.addr = *addr; 2111 rt->rt6i_dst.plen = 128; 2112 rt->rt6i_table = fib6_get_table(net, RT6_TABLE_LOCAL); 2113 2114 atomic_set(&rt->dst.__refcnt, 1); 2115 2116 return rt; 2117 } 2118 2119 int ip6_route_get_saddr(struct net *net, 2120 struct rt6_info *rt, 2121 const struct in6_addr *daddr, 2122 unsigned int prefs, 2123 struct in6_addr *saddr) 2124 { 2125 struct inet6_dev *idev = ip6_dst_idev((struct dst_entry*)rt); 2126 int err = 0; 2127 if (rt->rt6i_prefsrc.plen) 2128 *saddr = rt->rt6i_prefsrc.addr; 2129 else 2130 err = ipv6_dev_get_saddr(net, idev ? idev->dev : NULL, 2131 daddr, prefs, saddr); 2132 return err; 2133 } 2134 2135 /* remove deleted ip from prefsrc entries */ 2136 struct arg_dev_net_ip { 2137 struct net_device *dev; 2138 struct net *net; 2139 struct in6_addr *addr; 2140 }; 2141 2142 static int fib6_remove_prefsrc(struct rt6_info *rt, void *arg) 2143 { 2144 struct net_device *dev = ((struct arg_dev_net_ip *)arg)->dev; 2145 struct net *net = ((struct arg_dev_net_ip *)arg)->net; 2146 struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr; 2147 2148 if (((void *)rt->dst.dev == dev || !dev) && 2149 rt != net->ipv6.ip6_null_entry && 2150 ipv6_addr_equal(addr, &rt->rt6i_prefsrc.addr)) { 2151 /* remove prefsrc entry */ 2152 rt->rt6i_prefsrc.plen = 0; 2153 } 2154 return 0; 2155 } 2156 2157 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp) 2158 { 2159 struct net *net = dev_net(ifp->idev->dev); 2160 struct arg_dev_net_ip adni = { 2161 .dev = ifp->idev->dev, 2162 .net = net, 2163 .addr = &ifp->addr, 2164 }; 2165 fib6_clean_all(net, fib6_remove_prefsrc, 0, &adni); 2166 } 2167 2168 struct arg_dev_net { 2169 struct net_device *dev; 2170 struct net *net; 2171 }; 2172 2173 static int fib6_ifdown(struct rt6_info *rt, void *arg) 2174 { 2175 const struct arg_dev_net *adn = arg; 2176 const struct net_device *dev = adn->dev; 2177 2178 if ((rt->dst.dev == dev || !dev) && 2179 rt != adn->net->ipv6.ip6_null_entry) 2180 return -1; 2181 2182 return 0; 2183 } 2184 2185 void rt6_ifdown(struct net *net, struct net_device *dev) 2186 { 2187 struct arg_dev_net adn = { 2188 .dev = dev, 2189 .net = net, 2190 }; 2191 2192 fib6_clean_all(net, fib6_ifdown, 0, &adn); 2193 icmp6_clean_all(fib6_ifdown, &adn); 2194 } 2195 2196 struct rt6_mtu_change_arg 2197 { 2198 struct net_device *dev; 2199 unsigned mtu; 2200 }; 2201 2202 static int rt6_mtu_change_route(struct rt6_info *rt, void *p_arg) 2203 { 2204 struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg; 2205 struct inet6_dev *idev; 2206 2207 /* In IPv6 pmtu discovery is not optional, 2208 so that RTAX_MTU lock cannot disable it. 2209 We still use this lock to block changes 2210 caused by addrconf/ndisc. 2211 */ 2212 2213 idev = __in6_dev_get(arg->dev); 2214 if (!idev) 2215 return 0; 2216 2217 /* For administrative MTU increase, there is no way to discover 2218 IPv6 PMTU increase, so PMTU increase should be updated here. 2219 Since RFC 1981 doesn't include administrative MTU increase 2220 update PMTU increase is a MUST. (i.e. jumbo frame) 2221 */ 2222 /* 2223 If new MTU is less than route PMTU, this new MTU will be the 2224 lowest MTU in the path, update the route PMTU to reflect PMTU 2225 decreases; if new MTU is greater than route PMTU, and the 2226 old MTU is the lowest MTU in the path, update the route PMTU 2227 to reflect the increase. In this case if the other nodes' MTU 2228 also have the lowest MTU, TOO BIG MESSAGE will be lead to 2229 PMTU discouvery. 2230 */ 2231 if (rt->dst.dev == arg->dev && 2232 !dst_metric_locked(&rt->dst, RTAX_MTU) && 2233 (dst_mtu(&rt->dst) >= arg->mtu || 2234 (dst_mtu(&rt->dst) < arg->mtu && 2235 dst_mtu(&rt->dst) == idev->cnf.mtu6))) { 2236 dst_metric_set(&rt->dst, RTAX_MTU, arg->mtu); 2237 } 2238 return 0; 2239 } 2240 2241 void rt6_mtu_change(struct net_device *dev, unsigned mtu) 2242 { 2243 struct rt6_mtu_change_arg arg = { 2244 .dev = dev, 2245 .mtu = mtu, 2246 }; 2247 2248 fib6_clean_all(dev_net(dev), rt6_mtu_change_route, 0, &arg); 2249 } 2250 2251 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = { 2252 [RTA_GATEWAY] = { .len = sizeof(struct in6_addr) }, 2253 [RTA_OIF] = { .type = NLA_U32 }, 2254 [RTA_IIF] = { .type = NLA_U32 }, 2255 [RTA_PRIORITY] = { .type = NLA_U32 }, 2256 [RTA_METRICS] = { .type = NLA_NESTED }, 2257 }; 2258 2259 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh, 2260 struct fib6_config *cfg) 2261 { 2262 struct rtmsg *rtm; 2263 struct nlattr *tb[RTA_MAX+1]; 2264 int err; 2265 2266 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy); 2267 if (err < 0) 2268 goto errout; 2269 2270 err = -EINVAL; 2271 rtm = nlmsg_data(nlh); 2272 memset(cfg, 0, sizeof(*cfg)); 2273 2274 cfg->fc_table = rtm->rtm_table; 2275 cfg->fc_dst_len = rtm->rtm_dst_len; 2276 cfg->fc_src_len = rtm->rtm_src_len; 2277 cfg->fc_flags = RTF_UP; 2278 cfg->fc_protocol = rtm->rtm_protocol; 2279 2280 if (rtm->rtm_type == RTN_UNREACHABLE) 2281 cfg->fc_flags |= RTF_REJECT; 2282 2283 if (rtm->rtm_type == RTN_LOCAL) 2284 cfg->fc_flags |= RTF_LOCAL; 2285 2286 cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid; 2287 cfg->fc_nlinfo.nlh = nlh; 2288 cfg->fc_nlinfo.nl_net = sock_net(skb->sk); 2289 2290 if (tb[RTA_GATEWAY]) { 2291 nla_memcpy(&cfg->fc_gateway, tb[RTA_GATEWAY], 16); 2292 cfg->fc_flags |= RTF_GATEWAY; 2293 } 2294 2295 if (tb[RTA_DST]) { 2296 int plen = (rtm->rtm_dst_len + 7) >> 3; 2297 2298 if (nla_len(tb[RTA_DST]) < plen) 2299 goto errout; 2300 2301 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen); 2302 } 2303 2304 if (tb[RTA_SRC]) { 2305 int plen = (rtm->rtm_src_len + 7) >> 3; 2306 2307 if (nla_len(tb[RTA_SRC]) < plen) 2308 goto errout; 2309 2310 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen); 2311 } 2312 2313 if (tb[RTA_PREFSRC]) 2314 nla_memcpy(&cfg->fc_prefsrc, tb[RTA_PREFSRC], 16); 2315 2316 if (tb[RTA_OIF]) 2317 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]); 2318 2319 if (tb[RTA_PRIORITY]) 2320 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]); 2321 2322 if (tb[RTA_METRICS]) { 2323 cfg->fc_mx = nla_data(tb[RTA_METRICS]); 2324 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]); 2325 } 2326 2327 if (tb[RTA_TABLE]) 2328 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]); 2329 2330 err = 0; 2331 errout: 2332 return err; 2333 } 2334 2335 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 2336 { 2337 struct fib6_config cfg; 2338 int err; 2339 2340 err = rtm_to_fib6_config(skb, nlh, &cfg); 2341 if (err < 0) 2342 return err; 2343 2344 return ip6_route_del(&cfg); 2345 } 2346 2347 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 2348 { 2349 struct fib6_config cfg; 2350 int err; 2351 2352 err = rtm_to_fib6_config(skb, nlh, &cfg); 2353 if (err < 0) 2354 return err; 2355 2356 return ip6_route_add(&cfg); 2357 } 2358 2359 static inline size_t rt6_nlmsg_size(void) 2360 { 2361 return NLMSG_ALIGN(sizeof(struct rtmsg)) 2362 + nla_total_size(16) /* RTA_SRC */ 2363 + nla_total_size(16) /* RTA_DST */ 2364 + nla_total_size(16) /* RTA_GATEWAY */ 2365 + nla_total_size(16) /* RTA_PREFSRC */ 2366 + nla_total_size(4) /* RTA_TABLE */ 2367 + nla_total_size(4) /* RTA_IIF */ 2368 + nla_total_size(4) /* RTA_OIF */ 2369 + nla_total_size(4) /* RTA_PRIORITY */ 2370 + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */ 2371 + nla_total_size(sizeof(struct rta_cacheinfo)); 2372 } 2373 2374 static int rt6_fill_node(struct net *net, 2375 struct sk_buff *skb, struct rt6_info *rt, 2376 struct in6_addr *dst, struct in6_addr *src, 2377 int iif, int type, u32 pid, u32 seq, 2378 int prefix, int nowait, unsigned int flags) 2379 { 2380 const struct inet_peer *peer; 2381 struct rtmsg *rtm; 2382 struct nlmsghdr *nlh; 2383 long expires; 2384 u32 table; 2385 struct neighbour *n; 2386 u32 ts, tsage; 2387 2388 if (prefix) { /* user wants prefix routes only */ 2389 if (!(rt->rt6i_flags & RTF_PREFIX_RT)) { 2390 /* success since this is not a prefix route */ 2391 return 1; 2392 } 2393 } 2394 2395 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtm), flags); 2396 if (!nlh) 2397 return -EMSGSIZE; 2398 2399 rtm = nlmsg_data(nlh); 2400 rtm->rtm_family = AF_INET6; 2401 rtm->rtm_dst_len = rt->rt6i_dst.plen; 2402 rtm->rtm_src_len = rt->rt6i_src.plen; 2403 rtm->rtm_tos = 0; 2404 if (rt->rt6i_table) 2405 table = rt->rt6i_table->tb6_id; 2406 else 2407 table = RT6_TABLE_UNSPEC; 2408 rtm->rtm_table = table; 2409 NLA_PUT_U32(skb, RTA_TABLE, table); 2410 if (rt->rt6i_flags & RTF_REJECT) 2411 rtm->rtm_type = RTN_UNREACHABLE; 2412 else if (rt->rt6i_flags & RTF_LOCAL) 2413 rtm->rtm_type = RTN_LOCAL; 2414 else if (rt->dst.dev && (rt->dst.dev->flags & IFF_LOOPBACK)) 2415 rtm->rtm_type = RTN_LOCAL; 2416 else 2417 rtm->rtm_type = RTN_UNICAST; 2418 rtm->rtm_flags = 0; 2419 rtm->rtm_scope = RT_SCOPE_UNIVERSE; 2420 rtm->rtm_protocol = rt->rt6i_protocol; 2421 if (rt->rt6i_flags & RTF_DYNAMIC) 2422 rtm->rtm_protocol = RTPROT_REDIRECT; 2423 else if (rt->rt6i_flags & RTF_ADDRCONF) 2424 rtm->rtm_protocol = RTPROT_KERNEL; 2425 else if (rt->rt6i_flags & RTF_DEFAULT) 2426 rtm->rtm_protocol = RTPROT_RA; 2427 2428 if (rt->rt6i_flags & RTF_CACHE) 2429 rtm->rtm_flags |= RTM_F_CLONED; 2430 2431 if (dst) { 2432 NLA_PUT(skb, RTA_DST, 16, dst); 2433 rtm->rtm_dst_len = 128; 2434 } else if (rtm->rtm_dst_len) 2435 NLA_PUT(skb, RTA_DST, 16, &rt->rt6i_dst.addr); 2436 #ifdef CONFIG_IPV6_SUBTREES 2437 if (src) { 2438 NLA_PUT(skb, RTA_SRC, 16, src); 2439 rtm->rtm_src_len = 128; 2440 } else if (rtm->rtm_src_len) 2441 NLA_PUT(skb, RTA_SRC, 16, &rt->rt6i_src.addr); 2442 #endif 2443 if (iif) { 2444 #ifdef CONFIG_IPV6_MROUTE 2445 if (ipv6_addr_is_multicast(&rt->rt6i_dst.addr)) { 2446 int err = ip6mr_get_route(net, skb, rtm, nowait); 2447 if (err <= 0) { 2448 if (!nowait) { 2449 if (err == 0) 2450 return 0; 2451 goto nla_put_failure; 2452 } else { 2453 if (err == -EMSGSIZE) 2454 goto nla_put_failure; 2455 } 2456 } 2457 } else 2458 #endif 2459 NLA_PUT_U32(skb, RTA_IIF, iif); 2460 } else if (dst) { 2461 struct in6_addr saddr_buf; 2462 if (ip6_route_get_saddr(net, rt, dst, 0, &saddr_buf) == 0) 2463 NLA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf); 2464 } 2465 2466 if (rt->rt6i_prefsrc.plen) { 2467 struct in6_addr saddr_buf; 2468 saddr_buf = rt->rt6i_prefsrc.addr; 2469 NLA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf); 2470 } 2471 2472 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0) 2473 goto nla_put_failure; 2474 2475 rcu_read_lock(); 2476 n = dst_get_neighbour_noref(&rt->dst); 2477 if (n) 2478 NLA_PUT(skb, RTA_GATEWAY, 16, &n->primary_key); 2479 rcu_read_unlock(); 2480 2481 if (rt->dst.dev) 2482 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex); 2483 2484 NLA_PUT_U32(skb, RTA_PRIORITY, rt->rt6i_metric); 2485 2486 if (!(rt->rt6i_flags & RTF_EXPIRES)) 2487 expires = 0; 2488 else if (rt->dst.expires - jiffies < INT_MAX) 2489 expires = rt->dst.expires - jiffies; 2490 else 2491 expires = INT_MAX; 2492 2493 peer = rt->rt6i_peer; 2494 ts = tsage = 0; 2495 if (peer && peer->tcp_ts_stamp) { 2496 ts = peer->tcp_ts; 2497 tsage = get_seconds() - peer->tcp_ts_stamp; 2498 } 2499 2500 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, ts, tsage, 2501 expires, rt->dst.error) < 0) 2502 goto nla_put_failure; 2503 2504 return nlmsg_end(skb, nlh); 2505 2506 nla_put_failure: 2507 nlmsg_cancel(skb, nlh); 2508 return -EMSGSIZE; 2509 } 2510 2511 int rt6_dump_route(struct rt6_info *rt, void *p_arg) 2512 { 2513 struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg; 2514 int prefix; 2515 2516 if (nlmsg_len(arg->cb->nlh) >= sizeof(struct rtmsg)) { 2517 struct rtmsg *rtm = nlmsg_data(arg->cb->nlh); 2518 prefix = (rtm->rtm_flags & RTM_F_PREFIX) != 0; 2519 } else 2520 prefix = 0; 2521 2522 return rt6_fill_node(arg->net, 2523 arg->skb, rt, NULL, NULL, 0, RTM_NEWROUTE, 2524 NETLINK_CB(arg->cb->skb).pid, arg->cb->nlh->nlmsg_seq, 2525 prefix, 0, NLM_F_MULTI); 2526 } 2527 2528 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg) 2529 { 2530 struct net *net = sock_net(in_skb->sk); 2531 struct nlattr *tb[RTA_MAX+1]; 2532 struct rt6_info *rt; 2533 struct sk_buff *skb; 2534 struct rtmsg *rtm; 2535 struct flowi6 fl6; 2536 int err, iif = 0; 2537 2538 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy); 2539 if (err < 0) 2540 goto errout; 2541 2542 err = -EINVAL; 2543 memset(&fl6, 0, sizeof(fl6)); 2544 2545 if (tb[RTA_SRC]) { 2546 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr)) 2547 goto errout; 2548 2549 fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]); 2550 } 2551 2552 if (tb[RTA_DST]) { 2553 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr)) 2554 goto errout; 2555 2556 fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]); 2557 } 2558 2559 if (tb[RTA_IIF]) 2560 iif = nla_get_u32(tb[RTA_IIF]); 2561 2562 if (tb[RTA_OIF]) 2563 fl6.flowi6_oif = nla_get_u32(tb[RTA_OIF]); 2564 2565 if (iif) { 2566 struct net_device *dev; 2567 dev = __dev_get_by_index(net, iif); 2568 if (!dev) { 2569 err = -ENODEV; 2570 goto errout; 2571 } 2572 } 2573 2574 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2575 if (!skb) { 2576 err = -ENOBUFS; 2577 goto errout; 2578 } 2579 2580 /* Reserve room for dummy headers, this skb can pass 2581 through good chunk of routing engine. 2582 */ 2583 skb_reset_mac_header(skb); 2584 skb_reserve(skb, MAX_HEADER + sizeof(struct ipv6hdr)); 2585 2586 rt = (struct rt6_info*) ip6_route_output(net, NULL, &fl6); 2587 skb_dst_set(skb, &rt->dst); 2588 2589 err = rt6_fill_node(net, skb, rt, &fl6.daddr, &fl6.saddr, iif, 2590 RTM_NEWROUTE, NETLINK_CB(in_skb).pid, 2591 nlh->nlmsg_seq, 0, 0, 0); 2592 if (err < 0) { 2593 kfree_skb(skb); 2594 goto errout; 2595 } 2596 2597 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid); 2598 errout: 2599 return err; 2600 } 2601 2602 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info) 2603 { 2604 struct sk_buff *skb; 2605 struct net *net = info->nl_net; 2606 u32 seq; 2607 int err; 2608 2609 err = -ENOBUFS; 2610 seq = info->nlh ? info->nlh->nlmsg_seq : 0; 2611 2612 skb = nlmsg_new(rt6_nlmsg_size(), gfp_any()); 2613 if (!skb) 2614 goto errout; 2615 2616 err = rt6_fill_node(net, skb, rt, NULL, NULL, 0, 2617 event, info->pid, seq, 0, 0, 0); 2618 if (err < 0) { 2619 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */ 2620 WARN_ON(err == -EMSGSIZE); 2621 kfree_skb(skb); 2622 goto errout; 2623 } 2624 rtnl_notify(skb, net, info->pid, RTNLGRP_IPV6_ROUTE, 2625 info->nlh, gfp_any()); 2626 return; 2627 errout: 2628 if (err < 0) 2629 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err); 2630 } 2631 2632 static int ip6_route_dev_notify(struct notifier_block *this, 2633 unsigned long event, void *data) 2634 { 2635 struct net_device *dev = (struct net_device *)data; 2636 struct net *net = dev_net(dev); 2637 2638 if (event == NETDEV_REGISTER && (dev->flags & IFF_LOOPBACK)) { 2639 net->ipv6.ip6_null_entry->dst.dev = dev; 2640 net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev); 2641 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2642 net->ipv6.ip6_prohibit_entry->dst.dev = dev; 2643 net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev); 2644 net->ipv6.ip6_blk_hole_entry->dst.dev = dev; 2645 net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev); 2646 #endif 2647 } 2648 2649 return NOTIFY_OK; 2650 } 2651 2652 /* 2653 * /proc 2654 */ 2655 2656 #ifdef CONFIG_PROC_FS 2657 2658 struct rt6_proc_arg 2659 { 2660 char *buffer; 2661 int offset; 2662 int length; 2663 int skip; 2664 int len; 2665 }; 2666 2667 static int rt6_info_route(struct rt6_info *rt, void *p_arg) 2668 { 2669 struct seq_file *m = p_arg; 2670 struct neighbour *n; 2671 2672 seq_printf(m, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen); 2673 2674 #ifdef CONFIG_IPV6_SUBTREES 2675 seq_printf(m, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen); 2676 #else 2677 seq_puts(m, "00000000000000000000000000000000 00 "); 2678 #endif 2679 rcu_read_lock(); 2680 n = dst_get_neighbour_noref(&rt->dst); 2681 if (n) { 2682 seq_printf(m, "%pi6", n->primary_key); 2683 } else { 2684 seq_puts(m, "00000000000000000000000000000000"); 2685 } 2686 rcu_read_unlock(); 2687 seq_printf(m, " %08x %08x %08x %08x %8s\n", 2688 rt->rt6i_metric, atomic_read(&rt->dst.__refcnt), 2689 rt->dst.__use, rt->rt6i_flags, 2690 rt->dst.dev ? rt->dst.dev->name : ""); 2691 return 0; 2692 } 2693 2694 static int ipv6_route_show(struct seq_file *m, void *v) 2695 { 2696 struct net *net = (struct net *)m->private; 2697 fib6_clean_all_ro(net, rt6_info_route, 0, m); 2698 return 0; 2699 } 2700 2701 static int ipv6_route_open(struct inode *inode, struct file *file) 2702 { 2703 return single_open_net(inode, file, ipv6_route_show); 2704 } 2705 2706 static const struct file_operations ipv6_route_proc_fops = { 2707 .owner = THIS_MODULE, 2708 .open = ipv6_route_open, 2709 .read = seq_read, 2710 .llseek = seq_lseek, 2711 .release = single_release_net, 2712 }; 2713 2714 static int rt6_stats_seq_show(struct seq_file *seq, void *v) 2715 { 2716 struct net *net = (struct net *)seq->private; 2717 seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n", 2718 net->ipv6.rt6_stats->fib_nodes, 2719 net->ipv6.rt6_stats->fib_route_nodes, 2720 net->ipv6.rt6_stats->fib_rt_alloc, 2721 net->ipv6.rt6_stats->fib_rt_entries, 2722 net->ipv6.rt6_stats->fib_rt_cache, 2723 dst_entries_get_slow(&net->ipv6.ip6_dst_ops), 2724 net->ipv6.rt6_stats->fib_discarded_routes); 2725 2726 return 0; 2727 } 2728 2729 static int rt6_stats_seq_open(struct inode *inode, struct file *file) 2730 { 2731 return single_open_net(inode, file, rt6_stats_seq_show); 2732 } 2733 2734 static const struct file_operations rt6_stats_seq_fops = { 2735 .owner = THIS_MODULE, 2736 .open = rt6_stats_seq_open, 2737 .read = seq_read, 2738 .llseek = seq_lseek, 2739 .release = single_release_net, 2740 }; 2741 #endif /* CONFIG_PROC_FS */ 2742 2743 #ifdef CONFIG_SYSCTL 2744 2745 static 2746 int ipv6_sysctl_rtcache_flush(ctl_table *ctl, int write, 2747 void __user *buffer, size_t *lenp, loff_t *ppos) 2748 { 2749 struct net *net; 2750 int delay; 2751 if (!write) 2752 return -EINVAL; 2753 2754 net = (struct net *)ctl->extra1; 2755 delay = net->ipv6.sysctl.flush_delay; 2756 proc_dointvec(ctl, write, buffer, lenp, ppos); 2757 fib6_run_gc(delay <= 0 ? ~0UL : (unsigned long)delay, net); 2758 return 0; 2759 } 2760 2761 ctl_table ipv6_route_table_template[] = { 2762 { 2763 .procname = "flush", 2764 .data = &init_net.ipv6.sysctl.flush_delay, 2765 .maxlen = sizeof(int), 2766 .mode = 0200, 2767 .proc_handler = ipv6_sysctl_rtcache_flush 2768 }, 2769 { 2770 .procname = "gc_thresh", 2771 .data = &ip6_dst_ops_template.gc_thresh, 2772 .maxlen = sizeof(int), 2773 .mode = 0644, 2774 .proc_handler = proc_dointvec, 2775 }, 2776 { 2777 .procname = "max_size", 2778 .data = &init_net.ipv6.sysctl.ip6_rt_max_size, 2779 .maxlen = sizeof(int), 2780 .mode = 0644, 2781 .proc_handler = proc_dointvec, 2782 }, 2783 { 2784 .procname = "gc_min_interval", 2785 .data = &init_net.ipv6.sysctl.ip6_rt_gc_min_interval, 2786 .maxlen = sizeof(int), 2787 .mode = 0644, 2788 .proc_handler = proc_dointvec_jiffies, 2789 }, 2790 { 2791 .procname = "gc_timeout", 2792 .data = &init_net.ipv6.sysctl.ip6_rt_gc_timeout, 2793 .maxlen = sizeof(int), 2794 .mode = 0644, 2795 .proc_handler = proc_dointvec_jiffies, 2796 }, 2797 { 2798 .procname = "gc_interval", 2799 .data = &init_net.ipv6.sysctl.ip6_rt_gc_interval, 2800 .maxlen = sizeof(int), 2801 .mode = 0644, 2802 .proc_handler = proc_dointvec_jiffies, 2803 }, 2804 { 2805 .procname = "gc_elasticity", 2806 .data = &init_net.ipv6.sysctl.ip6_rt_gc_elasticity, 2807 .maxlen = sizeof(int), 2808 .mode = 0644, 2809 .proc_handler = proc_dointvec, 2810 }, 2811 { 2812 .procname = "mtu_expires", 2813 .data = &init_net.ipv6.sysctl.ip6_rt_mtu_expires, 2814 .maxlen = sizeof(int), 2815 .mode = 0644, 2816 .proc_handler = proc_dointvec_jiffies, 2817 }, 2818 { 2819 .procname = "min_adv_mss", 2820 .data = &init_net.ipv6.sysctl.ip6_rt_min_advmss, 2821 .maxlen = sizeof(int), 2822 .mode = 0644, 2823 .proc_handler = proc_dointvec, 2824 }, 2825 { 2826 .procname = "gc_min_interval_ms", 2827 .data = &init_net.ipv6.sysctl.ip6_rt_gc_min_interval, 2828 .maxlen = sizeof(int), 2829 .mode = 0644, 2830 .proc_handler = proc_dointvec_ms_jiffies, 2831 }, 2832 { } 2833 }; 2834 2835 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net) 2836 { 2837 struct ctl_table *table; 2838 2839 table = kmemdup(ipv6_route_table_template, 2840 sizeof(ipv6_route_table_template), 2841 GFP_KERNEL); 2842 2843 if (table) { 2844 table[0].data = &net->ipv6.sysctl.flush_delay; 2845 table[0].extra1 = net; 2846 table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh; 2847 table[2].data = &net->ipv6.sysctl.ip6_rt_max_size; 2848 table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval; 2849 table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout; 2850 table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval; 2851 table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity; 2852 table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires; 2853 table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss; 2854 table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval; 2855 } 2856 2857 return table; 2858 } 2859 #endif 2860 2861 static int __net_init ip6_route_net_init(struct net *net) 2862 { 2863 int ret = -ENOMEM; 2864 2865 memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template, 2866 sizeof(net->ipv6.ip6_dst_ops)); 2867 2868 if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0) 2869 goto out_ip6_dst_ops; 2870 2871 net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template, 2872 sizeof(*net->ipv6.ip6_null_entry), 2873 GFP_KERNEL); 2874 if (!net->ipv6.ip6_null_entry) 2875 goto out_ip6_dst_entries; 2876 net->ipv6.ip6_null_entry->dst.path = 2877 (struct dst_entry *)net->ipv6.ip6_null_entry; 2878 net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops; 2879 dst_init_metrics(&net->ipv6.ip6_null_entry->dst, 2880 ip6_template_metrics, true); 2881 2882 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2883 net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template, 2884 sizeof(*net->ipv6.ip6_prohibit_entry), 2885 GFP_KERNEL); 2886 if (!net->ipv6.ip6_prohibit_entry) 2887 goto out_ip6_null_entry; 2888 net->ipv6.ip6_prohibit_entry->dst.path = 2889 (struct dst_entry *)net->ipv6.ip6_prohibit_entry; 2890 net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops; 2891 dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst, 2892 ip6_template_metrics, true); 2893 2894 net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template, 2895 sizeof(*net->ipv6.ip6_blk_hole_entry), 2896 GFP_KERNEL); 2897 if (!net->ipv6.ip6_blk_hole_entry) 2898 goto out_ip6_prohibit_entry; 2899 net->ipv6.ip6_blk_hole_entry->dst.path = 2900 (struct dst_entry *)net->ipv6.ip6_blk_hole_entry; 2901 net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops; 2902 dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst, 2903 ip6_template_metrics, true); 2904 #endif 2905 2906 net->ipv6.sysctl.flush_delay = 0; 2907 net->ipv6.sysctl.ip6_rt_max_size = 4096; 2908 net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2; 2909 net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ; 2910 net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ; 2911 net->ipv6.sysctl.ip6_rt_gc_elasticity = 9; 2912 net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ; 2913 net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40; 2914 2915 #ifdef CONFIG_PROC_FS 2916 proc_net_fops_create(net, "ipv6_route", 0, &ipv6_route_proc_fops); 2917 proc_net_fops_create(net, "rt6_stats", S_IRUGO, &rt6_stats_seq_fops); 2918 #endif 2919 net->ipv6.ip6_rt_gc_expire = 30*HZ; 2920 2921 ret = 0; 2922 out: 2923 return ret; 2924 2925 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2926 out_ip6_prohibit_entry: 2927 kfree(net->ipv6.ip6_prohibit_entry); 2928 out_ip6_null_entry: 2929 kfree(net->ipv6.ip6_null_entry); 2930 #endif 2931 out_ip6_dst_entries: 2932 dst_entries_destroy(&net->ipv6.ip6_dst_ops); 2933 out_ip6_dst_ops: 2934 goto out; 2935 } 2936 2937 static void __net_exit ip6_route_net_exit(struct net *net) 2938 { 2939 #ifdef CONFIG_PROC_FS 2940 proc_net_remove(net, "ipv6_route"); 2941 proc_net_remove(net, "rt6_stats"); 2942 #endif 2943 kfree(net->ipv6.ip6_null_entry); 2944 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2945 kfree(net->ipv6.ip6_prohibit_entry); 2946 kfree(net->ipv6.ip6_blk_hole_entry); 2947 #endif 2948 dst_entries_destroy(&net->ipv6.ip6_dst_ops); 2949 } 2950 2951 static struct pernet_operations ip6_route_net_ops = { 2952 .init = ip6_route_net_init, 2953 .exit = ip6_route_net_exit, 2954 }; 2955 2956 static struct notifier_block ip6_route_dev_notifier = { 2957 .notifier_call = ip6_route_dev_notify, 2958 .priority = 0, 2959 }; 2960 2961 int __init ip6_route_init(void) 2962 { 2963 int ret; 2964 2965 ret = -ENOMEM; 2966 ip6_dst_ops_template.kmem_cachep = 2967 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0, 2968 SLAB_HWCACHE_ALIGN, NULL); 2969 if (!ip6_dst_ops_template.kmem_cachep) 2970 goto out; 2971 2972 ret = dst_entries_init(&ip6_dst_blackhole_ops); 2973 if (ret) 2974 goto out_kmem_cache; 2975 2976 ret = register_pernet_subsys(&ip6_route_net_ops); 2977 if (ret) 2978 goto out_dst_entries; 2979 2980 ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep; 2981 2982 /* Registering of the loopback is done before this portion of code, 2983 * the loopback reference in rt6_info will not be taken, do it 2984 * manually for init_net */ 2985 init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev; 2986 init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); 2987 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2988 init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev; 2989 init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); 2990 init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev; 2991 init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); 2992 #endif 2993 ret = fib6_init(); 2994 if (ret) 2995 goto out_register_subsys; 2996 2997 ret = xfrm6_init(); 2998 if (ret) 2999 goto out_fib6_init; 3000 3001 ret = fib6_rules_init(); 3002 if (ret) 3003 goto xfrm6_init; 3004 3005 ret = -ENOBUFS; 3006 if (__rtnl_register(PF_INET6, RTM_NEWROUTE, inet6_rtm_newroute, NULL, NULL) || 3007 __rtnl_register(PF_INET6, RTM_DELROUTE, inet6_rtm_delroute, NULL, NULL) || 3008 __rtnl_register(PF_INET6, RTM_GETROUTE, inet6_rtm_getroute, NULL, NULL)) 3009 goto fib6_rules_init; 3010 3011 ret = register_netdevice_notifier(&ip6_route_dev_notifier); 3012 if (ret) 3013 goto fib6_rules_init; 3014 3015 out: 3016 return ret; 3017 3018 fib6_rules_init: 3019 fib6_rules_cleanup(); 3020 xfrm6_init: 3021 xfrm6_fini(); 3022 out_fib6_init: 3023 fib6_gc_cleanup(); 3024 out_register_subsys: 3025 unregister_pernet_subsys(&ip6_route_net_ops); 3026 out_dst_entries: 3027 dst_entries_destroy(&ip6_dst_blackhole_ops); 3028 out_kmem_cache: 3029 kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep); 3030 goto out; 3031 } 3032 3033 void ip6_route_cleanup(void) 3034 { 3035 unregister_netdevice_notifier(&ip6_route_dev_notifier); 3036 fib6_rules_cleanup(); 3037 xfrm6_fini(); 3038 fib6_gc_cleanup(); 3039 unregister_pernet_subsys(&ip6_route_net_ops); 3040 dst_entries_destroy(&ip6_dst_blackhole_ops); 3041 kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep); 3042 } 3043