1 /* 2 * Linux INET6 implementation 3 * Forwarding Information Database 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 * Changes: 14 * Yuji SEKIYA @USAGI: Support default route on router node; 15 * remove ip6_null_entry from the top of 16 * routing table. 17 * Ville Nuorvala: Fixed routing subtrees. 18 */ 19 20 #define pr_fmt(fmt) "IPv6: " fmt 21 22 #include <linux/errno.h> 23 #include <linux/types.h> 24 #include <linux/net.h> 25 #include <linux/route.h> 26 #include <linux/netdevice.h> 27 #include <linux/in6.h> 28 #include <linux/init.h> 29 #include <linux/list.h> 30 #include <linux/slab.h> 31 32 #include <net/ipv6.h> 33 #include <net/ndisc.h> 34 #include <net/addrconf.h> 35 #include <net/lwtunnel.h> 36 #include <net/fib_notifier.h> 37 38 #include <net/ip6_fib.h> 39 #include <net/ip6_route.h> 40 41 static struct kmem_cache *fib6_node_kmem __read_mostly; 42 43 struct fib6_cleaner { 44 struct fib6_walker w; 45 struct net *net; 46 int (*func)(struct rt6_info *, void *arg); 47 int sernum; 48 void *arg; 49 }; 50 51 #ifdef CONFIG_IPV6_SUBTREES 52 #define FWS_INIT FWS_S 53 #else 54 #define FWS_INIT FWS_L 55 #endif 56 57 static struct rt6_info *fib6_find_prefix(struct net *net, 58 struct fib6_table *table, 59 struct fib6_node *fn); 60 static struct fib6_node *fib6_repair_tree(struct net *net, 61 struct fib6_table *table, 62 struct fib6_node *fn); 63 static int fib6_walk(struct net *net, struct fib6_walker *w); 64 static int fib6_walk_continue(struct fib6_walker *w); 65 66 /* 67 * A routing update causes an increase of the serial number on the 68 * affected subtree. This allows for cached routes to be asynchronously 69 * tested when modifications are made to the destination cache as a 70 * result of redirects, path MTU changes, etc. 71 */ 72 73 static void fib6_gc_timer_cb(struct timer_list *t); 74 75 #define FOR_WALKERS(net, w) \ 76 list_for_each_entry(w, &(net)->ipv6.fib6_walkers, lh) 77 78 static void fib6_walker_link(struct net *net, struct fib6_walker *w) 79 { 80 write_lock_bh(&net->ipv6.fib6_walker_lock); 81 list_add(&w->lh, &net->ipv6.fib6_walkers); 82 write_unlock_bh(&net->ipv6.fib6_walker_lock); 83 } 84 85 static void fib6_walker_unlink(struct net *net, struct fib6_walker *w) 86 { 87 write_lock_bh(&net->ipv6.fib6_walker_lock); 88 list_del(&w->lh); 89 write_unlock_bh(&net->ipv6.fib6_walker_lock); 90 } 91 92 static int fib6_new_sernum(struct net *net) 93 { 94 int new, old; 95 96 do { 97 old = atomic_read(&net->ipv6.fib6_sernum); 98 new = old < INT_MAX ? old + 1 : 1; 99 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum, 100 old, new) != old); 101 return new; 102 } 103 104 enum { 105 FIB6_NO_SERNUM_CHANGE = 0, 106 }; 107 108 void fib6_update_sernum(struct rt6_info *rt) 109 { 110 struct net *net = dev_net(rt->dst.dev); 111 struct fib6_node *fn; 112 113 fn = rcu_dereference_protected(rt->rt6i_node, 114 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 115 if (fn) 116 fn->fn_sernum = fib6_new_sernum(net); 117 } 118 119 /* 120 * Auxiliary address test functions for the radix tree. 121 * 122 * These assume a 32bit processor (although it will work on 123 * 64bit processors) 124 */ 125 126 /* 127 * test bit 128 */ 129 #if defined(__LITTLE_ENDIAN) 130 # define BITOP_BE32_SWIZZLE (0x1F & ~7) 131 #else 132 # define BITOP_BE32_SWIZZLE 0 133 #endif 134 135 static __be32 addr_bit_set(const void *token, int fn_bit) 136 { 137 const __be32 *addr = token; 138 /* 139 * Here, 140 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f) 141 * is optimized version of 142 * htonl(1 << ((~fn_bit)&0x1F)) 143 * See include/asm-generic/bitops/le.h. 144 */ 145 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) & 146 addr[fn_bit >> 5]; 147 } 148 149 static struct fib6_node *node_alloc(struct net *net) 150 { 151 struct fib6_node *fn; 152 153 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); 154 if (fn) 155 net->ipv6.rt6_stats->fib_nodes++; 156 157 return fn; 158 } 159 160 static void node_free_immediate(struct net *net, struct fib6_node *fn) 161 { 162 kmem_cache_free(fib6_node_kmem, fn); 163 net->ipv6.rt6_stats->fib_nodes--; 164 } 165 166 static void node_free_rcu(struct rcu_head *head) 167 { 168 struct fib6_node *fn = container_of(head, struct fib6_node, rcu); 169 170 kmem_cache_free(fib6_node_kmem, fn); 171 } 172 173 static void node_free(struct net *net, struct fib6_node *fn) 174 { 175 call_rcu(&fn->rcu, node_free_rcu); 176 net->ipv6.rt6_stats->fib_nodes--; 177 } 178 179 void rt6_free_pcpu(struct rt6_info *non_pcpu_rt) 180 { 181 int cpu; 182 183 if (!non_pcpu_rt->rt6i_pcpu) 184 return; 185 186 for_each_possible_cpu(cpu) { 187 struct rt6_info **ppcpu_rt; 188 struct rt6_info *pcpu_rt; 189 190 ppcpu_rt = per_cpu_ptr(non_pcpu_rt->rt6i_pcpu, cpu); 191 pcpu_rt = *ppcpu_rt; 192 if (pcpu_rt) { 193 dst_dev_put(&pcpu_rt->dst); 194 dst_release(&pcpu_rt->dst); 195 *ppcpu_rt = NULL; 196 } 197 } 198 } 199 EXPORT_SYMBOL_GPL(rt6_free_pcpu); 200 201 static void fib6_free_table(struct fib6_table *table) 202 { 203 inetpeer_invalidate_tree(&table->tb6_peers); 204 kfree(table); 205 } 206 207 static void fib6_link_table(struct net *net, struct fib6_table *tb) 208 { 209 unsigned int h; 210 211 /* 212 * Initialize table lock at a single place to give lockdep a key, 213 * tables aren't visible prior to being linked to the list. 214 */ 215 spin_lock_init(&tb->tb6_lock); 216 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 217 218 /* 219 * No protection necessary, this is the only list mutatation 220 * operation, tables never disappear once they exist. 221 */ 222 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 223 } 224 225 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 226 227 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 228 { 229 struct fib6_table *table; 230 231 table = kzalloc(sizeof(*table), GFP_ATOMIC); 232 if (table) { 233 table->tb6_id = id; 234 rcu_assign_pointer(table->tb6_root.leaf, 235 net->ipv6.ip6_null_entry); 236 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 237 inet_peer_base_init(&table->tb6_peers); 238 } 239 240 return table; 241 } 242 243 struct fib6_table *fib6_new_table(struct net *net, u32 id) 244 { 245 struct fib6_table *tb; 246 247 if (id == 0) 248 id = RT6_TABLE_MAIN; 249 tb = fib6_get_table(net, id); 250 if (tb) 251 return tb; 252 253 tb = fib6_alloc_table(net, id); 254 if (tb) 255 fib6_link_table(net, tb); 256 257 return tb; 258 } 259 EXPORT_SYMBOL_GPL(fib6_new_table); 260 261 struct fib6_table *fib6_get_table(struct net *net, u32 id) 262 { 263 struct fib6_table *tb; 264 struct hlist_head *head; 265 unsigned int h; 266 267 if (id == 0) 268 id = RT6_TABLE_MAIN; 269 h = id & (FIB6_TABLE_HASHSZ - 1); 270 rcu_read_lock(); 271 head = &net->ipv6.fib_table_hash[h]; 272 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 273 if (tb->tb6_id == id) { 274 rcu_read_unlock(); 275 return tb; 276 } 277 } 278 rcu_read_unlock(); 279 280 return NULL; 281 } 282 EXPORT_SYMBOL_GPL(fib6_get_table); 283 284 static void __net_init fib6_tables_init(struct net *net) 285 { 286 fib6_link_table(net, net->ipv6.fib6_main_tbl); 287 fib6_link_table(net, net->ipv6.fib6_local_tbl); 288 } 289 #else 290 291 struct fib6_table *fib6_new_table(struct net *net, u32 id) 292 { 293 return fib6_get_table(net, id); 294 } 295 296 struct fib6_table *fib6_get_table(struct net *net, u32 id) 297 { 298 return net->ipv6.fib6_main_tbl; 299 } 300 301 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 302 const struct sk_buff *skb, 303 int flags, pol_lookup_t lookup) 304 { 305 struct rt6_info *rt; 306 307 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags); 308 if (rt->dst.error == -EAGAIN) { 309 ip6_rt_put(rt); 310 rt = net->ipv6.ip6_null_entry; 311 dst_hold(&rt->dst); 312 } 313 314 return &rt->dst; 315 } 316 317 static void __net_init fib6_tables_init(struct net *net) 318 { 319 fib6_link_table(net, net->ipv6.fib6_main_tbl); 320 } 321 322 #endif 323 324 unsigned int fib6_tables_seq_read(struct net *net) 325 { 326 unsigned int h, fib_seq = 0; 327 328 rcu_read_lock(); 329 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 330 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 331 struct fib6_table *tb; 332 333 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 334 fib_seq += tb->fib_seq; 335 } 336 rcu_read_unlock(); 337 338 return fib_seq; 339 } 340 341 static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net, 342 enum fib_event_type event_type, 343 struct rt6_info *rt) 344 { 345 struct fib6_entry_notifier_info info = { 346 .rt = rt, 347 }; 348 349 return call_fib6_notifier(nb, net, event_type, &info.info); 350 } 351 352 static int call_fib6_entry_notifiers(struct net *net, 353 enum fib_event_type event_type, 354 struct rt6_info *rt, 355 struct netlink_ext_ack *extack) 356 { 357 struct fib6_entry_notifier_info info = { 358 .info.extack = extack, 359 .rt = rt, 360 }; 361 362 rt->rt6i_table->fib_seq++; 363 return call_fib6_notifiers(net, event_type, &info.info); 364 } 365 366 struct fib6_dump_arg { 367 struct net *net; 368 struct notifier_block *nb; 369 }; 370 371 static void fib6_rt_dump(struct rt6_info *rt, struct fib6_dump_arg *arg) 372 { 373 if (rt == arg->net->ipv6.ip6_null_entry) 374 return; 375 call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt); 376 } 377 378 static int fib6_node_dump(struct fib6_walker *w) 379 { 380 struct rt6_info *rt; 381 382 for_each_fib6_walker_rt(w) 383 fib6_rt_dump(rt, w->args); 384 w->leaf = NULL; 385 return 0; 386 } 387 388 static void fib6_table_dump(struct net *net, struct fib6_table *tb, 389 struct fib6_walker *w) 390 { 391 w->root = &tb->tb6_root; 392 spin_lock_bh(&tb->tb6_lock); 393 fib6_walk(net, w); 394 spin_unlock_bh(&tb->tb6_lock); 395 } 396 397 /* Called with rcu_read_lock() */ 398 int fib6_tables_dump(struct net *net, struct notifier_block *nb) 399 { 400 struct fib6_dump_arg arg; 401 struct fib6_walker *w; 402 unsigned int h; 403 404 w = kzalloc(sizeof(*w), GFP_ATOMIC); 405 if (!w) 406 return -ENOMEM; 407 408 w->func = fib6_node_dump; 409 arg.net = net; 410 arg.nb = nb; 411 w->args = &arg; 412 413 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 414 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 415 struct fib6_table *tb; 416 417 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 418 fib6_table_dump(net, tb, w); 419 } 420 421 kfree(w); 422 423 return 0; 424 } 425 426 static int fib6_dump_node(struct fib6_walker *w) 427 { 428 int res; 429 struct rt6_info *rt; 430 431 for_each_fib6_walker_rt(w) { 432 res = rt6_dump_route(rt, w->args); 433 if (res < 0) { 434 /* Frame is full, suspend walking */ 435 w->leaf = rt; 436 return 1; 437 } 438 439 /* Multipath routes are dumped in one route with the 440 * RTA_MULTIPATH attribute. Jump 'rt' to point to the 441 * last sibling of this route (no need to dump the 442 * sibling routes again) 443 */ 444 if (rt->rt6i_nsiblings) 445 rt = list_last_entry(&rt->rt6i_siblings, 446 struct rt6_info, 447 rt6i_siblings); 448 } 449 w->leaf = NULL; 450 return 0; 451 } 452 453 static void fib6_dump_end(struct netlink_callback *cb) 454 { 455 struct net *net = sock_net(cb->skb->sk); 456 struct fib6_walker *w = (void *)cb->args[2]; 457 458 if (w) { 459 if (cb->args[4]) { 460 cb->args[4] = 0; 461 fib6_walker_unlink(net, w); 462 } 463 cb->args[2] = 0; 464 kfree(w); 465 } 466 cb->done = (void *)cb->args[3]; 467 cb->args[1] = 3; 468 } 469 470 static int fib6_dump_done(struct netlink_callback *cb) 471 { 472 fib6_dump_end(cb); 473 return cb->done ? cb->done(cb) : 0; 474 } 475 476 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 477 struct netlink_callback *cb) 478 { 479 struct net *net = sock_net(skb->sk); 480 struct fib6_walker *w; 481 int res; 482 483 w = (void *)cb->args[2]; 484 w->root = &table->tb6_root; 485 486 if (cb->args[4] == 0) { 487 w->count = 0; 488 w->skip = 0; 489 490 spin_lock_bh(&table->tb6_lock); 491 res = fib6_walk(net, w); 492 spin_unlock_bh(&table->tb6_lock); 493 if (res > 0) { 494 cb->args[4] = 1; 495 cb->args[5] = w->root->fn_sernum; 496 } 497 } else { 498 if (cb->args[5] != w->root->fn_sernum) { 499 /* Begin at the root if the tree changed */ 500 cb->args[5] = w->root->fn_sernum; 501 w->state = FWS_INIT; 502 w->node = w->root; 503 w->skip = w->count; 504 } else 505 w->skip = 0; 506 507 spin_lock_bh(&table->tb6_lock); 508 res = fib6_walk_continue(w); 509 spin_unlock_bh(&table->tb6_lock); 510 if (res <= 0) { 511 fib6_walker_unlink(net, w); 512 cb->args[4] = 0; 513 } 514 } 515 516 return res; 517 } 518 519 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 520 { 521 struct net *net = sock_net(skb->sk); 522 unsigned int h, s_h; 523 unsigned int e = 0, s_e; 524 struct rt6_rtnl_dump_arg arg; 525 struct fib6_walker *w; 526 struct fib6_table *tb; 527 struct hlist_head *head; 528 int res = 0; 529 530 s_h = cb->args[0]; 531 s_e = cb->args[1]; 532 533 w = (void *)cb->args[2]; 534 if (!w) { 535 /* New dump: 536 * 537 * 1. hook callback destructor. 538 */ 539 cb->args[3] = (long)cb->done; 540 cb->done = fib6_dump_done; 541 542 /* 543 * 2. allocate and initialize walker. 544 */ 545 w = kzalloc(sizeof(*w), GFP_ATOMIC); 546 if (!w) 547 return -ENOMEM; 548 w->func = fib6_dump_node; 549 cb->args[2] = (long)w; 550 } 551 552 arg.skb = skb; 553 arg.cb = cb; 554 arg.net = net; 555 w->args = &arg; 556 557 rcu_read_lock(); 558 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 559 e = 0; 560 head = &net->ipv6.fib_table_hash[h]; 561 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 562 if (e < s_e) 563 goto next; 564 res = fib6_dump_table(tb, skb, cb); 565 if (res != 0) 566 goto out; 567 next: 568 e++; 569 } 570 } 571 out: 572 rcu_read_unlock(); 573 cb->args[1] = e; 574 cb->args[0] = h; 575 576 res = res < 0 ? res : skb->len; 577 if (res <= 0) 578 fib6_dump_end(cb); 579 return res; 580 } 581 582 /* 583 * Routing Table 584 * 585 * return the appropriate node for a routing tree "add" operation 586 * by either creating and inserting or by returning an existing 587 * node. 588 */ 589 590 static struct fib6_node *fib6_add_1(struct net *net, 591 struct fib6_table *table, 592 struct fib6_node *root, 593 struct in6_addr *addr, int plen, 594 int offset, int allow_create, 595 int replace_required, 596 struct netlink_ext_ack *extack) 597 { 598 struct fib6_node *fn, *in, *ln; 599 struct fib6_node *pn = NULL; 600 struct rt6key *key; 601 int bit; 602 __be32 dir = 0; 603 604 RT6_TRACE("fib6_add_1\n"); 605 606 /* insert node in tree */ 607 608 fn = root; 609 610 do { 611 struct rt6_info *leaf = rcu_dereference_protected(fn->leaf, 612 lockdep_is_held(&table->tb6_lock)); 613 key = (struct rt6key *)((u8 *)leaf + offset); 614 615 /* 616 * Prefix match 617 */ 618 if (plen < fn->fn_bit || 619 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 620 if (!allow_create) { 621 if (replace_required) { 622 NL_SET_ERR_MSG(extack, 623 "Can not replace route - no match found"); 624 pr_warn("Can't replace route, no match found\n"); 625 return ERR_PTR(-ENOENT); 626 } 627 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 628 } 629 goto insert_above; 630 } 631 632 /* 633 * Exact match ? 634 */ 635 636 if (plen == fn->fn_bit) { 637 /* clean up an intermediate node */ 638 if (!(fn->fn_flags & RTN_RTINFO)) { 639 RCU_INIT_POINTER(fn->leaf, NULL); 640 rt6_release(leaf); 641 /* remove null_entry in the root node */ 642 } else if (fn->fn_flags & RTN_TL_ROOT && 643 rcu_access_pointer(fn->leaf) == 644 net->ipv6.ip6_null_entry) { 645 RCU_INIT_POINTER(fn->leaf, NULL); 646 } 647 648 return fn; 649 } 650 651 /* 652 * We have more bits to go 653 */ 654 655 /* Try to walk down on tree. */ 656 dir = addr_bit_set(addr, fn->fn_bit); 657 pn = fn; 658 fn = dir ? 659 rcu_dereference_protected(fn->right, 660 lockdep_is_held(&table->tb6_lock)) : 661 rcu_dereference_protected(fn->left, 662 lockdep_is_held(&table->tb6_lock)); 663 } while (fn); 664 665 if (!allow_create) { 666 /* We should not create new node because 667 * NLM_F_REPLACE was specified without NLM_F_CREATE 668 * I assume it is safe to require NLM_F_CREATE when 669 * REPLACE flag is used! Later we may want to remove the 670 * check for replace_required, because according 671 * to netlink specification, NLM_F_CREATE 672 * MUST be specified if new route is created. 673 * That would keep IPv6 consistent with IPv4 674 */ 675 if (replace_required) { 676 NL_SET_ERR_MSG(extack, 677 "Can not replace route - no match found"); 678 pr_warn("Can't replace route, no match found\n"); 679 return ERR_PTR(-ENOENT); 680 } 681 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 682 } 683 /* 684 * We walked to the bottom of tree. 685 * Create new leaf node without children. 686 */ 687 688 ln = node_alloc(net); 689 690 if (!ln) 691 return ERR_PTR(-ENOMEM); 692 ln->fn_bit = plen; 693 RCU_INIT_POINTER(ln->parent, pn); 694 695 if (dir) 696 rcu_assign_pointer(pn->right, ln); 697 else 698 rcu_assign_pointer(pn->left, ln); 699 700 return ln; 701 702 703 insert_above: 704 /* 705 * split since we don't have a common prefix anymore or 706 * we have a less significant route. 707 * we've to insert an intermediate node on the list 708 * this new node will point to the one we need to create 709 * and the current 710 */ 711 712 pn = rcu_dereference_protected(fn->parent, 713 lockdep_is_held(&table->tb6_lock)); 714 715 /* find 1st bit in difference between the 2 addrs. 716 717 See comment in __ipv6_addr_diff: bit may be an invalid value, 718 but if it is >= plen, the value is ignored in any case. 719 */ 720 721 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 722 723 /* 724 * (intermediate)[in] 725 * / \ 726 * (new leaf node)[ln] (old node)[fn] 727 */ 728 if (plen > bit) { 729 in = node_alloc(net); 730 ln = node_alloc(net); 731 732 if (!in || !ln) { 733 if (in) 734 node_free_immediate(net, in); 735 if (ln) 736 node_free_immediate(net, ln); 737 return ERR_PTR(-ENOMEM); 738 } 739 740 /* 741 * new intermediate node. 742 * RTN_RTINFO will 743 * be off since that an address that chooses one of 744 * the branches would not match less specific routes 745 * in the other branch 746 */ 747 748 in->fn_bit = bit; 749 750 RCU_INIT_POINTER(in->parent, pn); 751 in->leaf = fn->leaf; 752 atomic_inc(&rcu_dereference_protected(in->leaf, 753 lockdep_is_held(&table->tb6_lock))->rt6i_ref); 754 755 /* update parent pointer */ 756 if (dir) 757 rcu_assign_pointer(pn->right, in); 758 else 759 rcu_assign_pointer(pn->left, in); 760 761 ln->fn_bit = plen; 762 763 RCU_INIT_POINTER(ln->parent, in); 764 rcu_assign_pointer(fn->parent, in); 765 766 if (addr_bit_set(addr, bit)) { 767 rcu_assign_pointer(in->right, ln); 768 rcu_assign_pointer(in->left, fn); 769 } else { 770 rcu_assign_pointer(in->left, ln); 771 rcu_assign_pointer(in->right, fn); 772 } 773 } else { /* plen <= bit */ 774 775 /* 776 * (new leaf node)[ln] 777 * / \ 778 * (old node)[fn] NULL 779 */ 780 781 ln = node_alloc(net); 782 783 if (!ln) 784 return ERR_PTR(-ENOMEM); 785 786 ln->fn_bit = plen; 787 788 RCU_INIT_POINTER(ln->parent, pn); 789 790 if (addr_bit_set(&key->addr, plen)) 791 RCU_INIT_POINTER(ln->right, fn); 792 else 793 RCU_INIT_POINTER(ln->left, fn); 794 795 rcu_assign_pointer(fn->parent, ln); 796 797 if (dir) 798 rcu_assign_pointer(pn->right, ln); 799 else 800 rcu_assign_pointer(pn->left, ln); 801 } 802 return ln; 803 } 804 805 static void fib6_copy_metrics(u32 *mp, const struct mx6_config *mxc) 806 { 807 int i; 808 809 for (i = 0; i < RTAX_MAX; i++) { 810 if (test_bit(i, mxc->mx_valid)) 811 mp[i] = mxc->mx[i]; 812 } 813 } 814 815 static int fib6_commit_metrics(struct dst_entry *dst, struct mx6_config *mxc) 816 { 817 if (!mxc->mx) 818 return 0; 819 820 if (dst->flags & DST_HOST) { 821 u32 *mp = dst_metrics_write_ptr(dst); 822 823 if (unlikely(!mp)) 824 return -ENOMEM; 825 826 fib6_copy_metrics(mp, mxc); 827 } else { 828 dst_init_metrics(dst, mxc->mx, false); 829 830 /* We've stolen mx now. */ 831 mxc->mx = NULL; 832 } 833 834 return 0; 835 } 836 837 static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn, 838 struct net *net) 839 { 840 struct fib6_table *table = rt->rt6i_table; 841 842 if (atomic_read(&rt->rt6i_ref) != 1) { 843 /* This route is used as dummy address holder in some split 844 * nodes. It is not leaked, but it still holds other resources, 845 * which must be released in time. So, scan ascendant nodes 846 * and replace dummy references to this route with references 847 * to still alive ones. 848 */ 849 while (fn) { 850 struct rt6_info *leaf = rcu_dereference_protected(fn->leaf, 851 lockdep_is_held(&table->tb6_lock)); 852 struct rt6_info *new_leaf; 853 if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) { 854 new_leaf = fib6_find_prefix(net, table, fn); 855 atomic_inc(&new_leaf->rt6i_ref); 856 rcu_assign_pointer(fn->leaf, new_leaf); 857 rt6_release(rt); 858 } 859 fn = rcu_dereference_protected(fn->parent, 860 lockdep_is_held(&table->tb6_lock)); 861 } 862 } 863 } 864 865 /* 866 * Insert routing information in a node. 867 */ 868 869 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, 870 struct nl_info *info, struct mx6_config *mxc, 871 struct netlink_ext_ack *extack) 872 { 873 struct rt6_info *leaf = rcu_dereference_protected(fn->leaf, 874 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 875 struct rt6_info *iter = NULL; 876 struct rt6_info __rcu **ins; 877 struct rt6_info __rcu **fallback_ins = NULL; 878 int replace = (info->nlh && 879 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 880 int add = (!info->nlh || 881 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 882 int found = 0; 883 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 884 u16 nlflags = NLM_F_EXCL; 885 int err; 886 887 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND)) 888 nlflags |= NLM_F_APPEND; 889 890 ins = &fn->leaf; 891 892 for (iter = leaf; iter; 893 iter = rcu_dereference_protected(iter->rt6_next, 894 lockdep_is_held(&rt->rt6i_table->tb6_lock))) { 895 /* 896 * Search for duplicates 897 */ 898 899 if (iter->rt6i_metric == rt->rt6i_metric) { 900 /* 901 * Same priority level 902 */ 903 if (info->nlh && 904 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 905 return -EEXIST; 906 907 nlflags &= ~NLM_F_EXCL; 908 if (replace) { 909 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) { 910 found++; 911 break; 912 } 913 if (rt_can_ecmp) 914 fallback_ins = fallback_ins ?: ins; 915 goto next_iter; 916 } 917 918 if (rt6_duplicate_nexthop(iter, rt)) { 919 if (rt->rt6i_nsiblings) 920 rt->rt6i_nsiblings = 0; 921 if (!(iter->rt6i_flags & RTF_EXPIRES)) 922 return -EEXIST; 923 if (!(rt->rt6i_flags & RTF_EXPIRES)) 924 rt6_clean_expires(iter); 925 else 926 rt6_set_expires(iter, rt->dst.expires); 927 iter->rt6i_pmtu = rt->rt6i_pmtu; 928 return -EEXIST; 929 } 930 /* If we have the same destination and the same metric, 931 * but not the same gateway, then the route we try to 932 * add is sibling to this route, increment our counter 933 * of siblings, and later we will add our route to the 934 * list. 935 * Only static routes (which don't have flag 936 * RTF_EXPIRES) are used for ECMPv6. 937 * 938 * To avoid long list, we only had siblings if the 939 * route have a gateway. 940 */ 941 if (rt_can_ecmp && 942 rt6_qualify_for_ecmp(iter)) 943 rt->rt6i_nsiblings++; 944 } 945 946 if (iter->rt6i_metric > rt->rt6i_metric) 947 break; 948 949 next_iter: 950 ins = &iter->rt6_next; 951 } 952 953 if (fallback_ins && !found) { 954 /* No ECMP-able route found, replace first non-ECMP one */ 955 ins = fallback_ins; 956 iter = rcu_dereference_protected(*ins, 957 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 958 found++; 959 } 960 961 /* Reset round-robin state, if necessary */ 962 if (ins == &fn->leaf) 963 fn->rr_ptr = NULL; 964 965 /* Link this route to others same route. */ 966 if (rt->rt6i_nsiblings) { 967 unsigned int rt6i_nsiblings; 968 struct rt6_info *sibling, *temp_sibling; 969 970 /* Find the first route that have the same metric */ 971 sibling = leaf; 972 while (sibling) { 973 if (sibling->rt6i_metric == rt->rt6i_metric && 974 rt6_qualify_for_ecmp(sibling)) { 975 list_add_tail(&rt->rt6i_siblings, 976 &sibling->rt6i_siblings); 977 break; 978 } 979 sibling = rcu_dereference_protected(sibling->rt6_next, 980 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 981 } 982 /* For each sibling in the list, increment the counter of 983 * siblings. BUG() if counters does not match, list of siblings 984 * is broken! 985 */ 986 rt6i_nsiblings = 0; 987 list_for_each_entry_safe(sibling, temp_sibling, 988 &rt->rt6i_siblings, rt6i_siblings) { 989 sibling->rt6i_nsiblings++; 990 BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings); 991 rt6i_nsiblings++; 992 } 993 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings); 994 rt6_multipath_rebalance(temp_sibling); 995 } 996 997 /* 998 * insert node 999 */ 1000 if (!replace) { 1001 if (!add) 1002 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 1003 1004 add: 1005 nlflags |= NLM_F_CREATE; 1006 err = fib6_commit_metrics(&rt->dst, mxc); 1007 if (err) 1008 return err; 1009 1010 err = call_fib6_entry_notifiers(info->nl_net, 1011 FIB_EVENT_ENTRY_ADD, 1012 rt, extack); 1013 if (err) 1014 return err; 1015 1016 rcu_assign_pointer(rt->rt6_next, iter); 1017 atomic_inc(&rt->rt6i_ref); 1018 rcu_assign_pointer(rt->rt6i_node, fn); 1019 rcu_assign_pointer(*ins, rt); 1020 if (!info->skip_notify) 1021 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); 1022 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 1023 1024 if (!(fn->fn_flags & RTN_RTINFO)) { 1025 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1026 fn->fn_flags |= RTN_RTINFO; 1027 } 1028 1029 } else { 1030 int nsiblings; 1031 1032 if (!found) { 1033 if (add) 1034 goto add; 1035 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 1036 return -ENOENT; 1037 } 1038 1039 err = fib6_commit_metrics(&rt->dst, mxc); 1040 if (err) 1041 return err; 1042 1043 err = call_fib6_entry_notifiers(info->nl_net, 1044 FIB_EVENT_ENTRY_REPLACE, 1045 rt, extack); 1046 if (err) 1047 return err; 1048 1049 atomic_inc(&rt->rt6i_ref); 1050 rcu_assign_pointer(rt->rt6i_node, fn); 1051 rt->rt6_next = iter->rt6_next; 1052 rcu_assign_pointer(*ins, rt); 1053 if (!info->skip_notify) 1054 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); 1055 if (!(fn->fn_flags & RTN_RTINFO)) { 1056 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1057 fn->fn_flags |= RTN_RTINFO; 1058 } 1059 nsiblings = iter->rt6i_nsiblings; 1060 iter->rt6i_node = NULL; 1061 fib6_purge_rt(iter, fn, info->nl_net); 1062 if (rcu_access_pointer(fn->rr_ptr) == iter) 1063 fn->rr_ptr = NULL; 1064 rt6_release(iter); 1065 1066 if (nsiblings) { 1067 /* Replacing an ECMP route, remove all siblings */ 1068 ins = &rt->rt6_next; 1069 iter = rcu_dereference_protected(*ins, 1070 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 1071 while (iter) { 1072 if (iter->rt6i_metric > rt->rt6i_metric) 1073 break; 1074 if (rt6_qualify_for_ecmp(iter)) { 1075 *ins = iter->rt6_next; 1076 iter->rt6i_node = NULL; 1077 fib6_purge_rt(iter, fn, info->nl_net); 1078 if (rcu_access_pointer(fn->rr_ptr) == iter) 1079 fn->rr_ptr = NULL; 1080 rt6_release(iter); 1081 nsiblings--; 1082 info->nl_net->ipv6.rt6_stats->fib_rt_entries--; 1083 } else { 1084 ins = &iter->rt6_next; 1085 } 1086 iter = rcu_dereference_protected(*ins, 1087 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 1088 } 1089 WARN_ON(nsiblings != 0); 1090 } 1091 } 1092 1093 return 0; 1094 } 1095 1096 static void fib6_start_gc(struct net *net, struct rt6_info *rt) 1097 { 1098 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 1099 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE))) 1100 mod_timer(&net->ipv6.ip6_fib_timer, 1101 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1102 } 1103 1104 void fib6_force_start_gc(struct net *net) 1105 { 1106 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 1107 mod_timer(&net->ipv6.ip6_fib_timer, 1108 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1109 } 1110 1111 static void __fib6_update_sernum_upto_root(struct rt6_info *rt, 1112 int sernum) 1113 { 1114 struct fib6_node *fn = rcu_dereference_protected(rt->rt6i_node, 1115 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 1116 1117 /* paired with smp_rmb() in rt6_get_cookie_safe() */ 1118 smp_wmb(); 1119 while (fn) { 1120 fn->fn_sernum = sernum; 1121 fn = rcu_dereference_protected(fn->parent, 1122 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 1123 } 1124 } 1125 1126 void fib6_update_sernum_upto_root(struct net *net, struct rt6_info *rt) 1127 { 1128 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net)); 1129 } 1130 1131 /* 1132 * Add routing information to the routing tree. 1133 * <destination addr>/<source addr> 1134 * with source addr info in sub-trees 1135 * Need to own table->tb6_lock 1136 */ 1137 1138 int fib6_add(struct fib6_node *root, struct rt6_info *rt, 1139 struct nl_info *info, struct mx6_config *mxc, 1140 struct netlink_ext_ack *extack) 1141 { 1142 struct fib6_table *table = rt->rt6i_table; 1143 struct fib6_node *fn, *pn = NULL; 1144 int err = -ENOMEM; 1145 int allow_create = 1; 1146 int replace_required = 0; 1147 int sernum = fib6_new_sernum(info->nl_net); 1148 1149 if (WARN_ON_ONCE(!atomic_read(&rt->dst.__refcnt))) 1150 return -EINVAL; 1151 if (WARN_ON_ONCE(rt->rt6i_flags & RTF_CACHE)) 1152 return -EINVAL; 1153 1154 if (info->nlh) { 1155 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 1156 allow_create = 0; 1157 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 1158 replace_required = 1; 1159 } 1160 if (!allow_create && !replace_required) 1161 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 1162 1163 fn = fib6_add_1(info->nl_net, table, root, 1164 &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 1165 offsetof(struct rt6_info, rt6i_dst), allow_create, 1166 replace_required, extack); 1167 if (IS_ERR(fn)) { 1168 err = PTR_ERR(fn); 1169 fn = NULL; 1170 goto out; 1171 } 1172 1173 pn = fn; 1174 1175 #ifdef CONFIG_IPV6_SUBTREES 1176 if (rt->rt6i_src.plen) { 1177 struct fib6_node *sn; 1178 1179 if (!rcu_access_pointer(fn->subtree)) { 1180 struct fib6_node *sfn; 1181 1182 /* 1183 * Create subtree. 1184 * 1185 * fn[main tree] 1186 * | 1187 * sfn[subtree root] 1188 * \ 1189 * sn[new leaf node] 1190 */ 1191 1192 /* Create subtree root node */ 1193 sfn = node_alloc(info->nl_net); 1194 if (!sfn) 1195 goto failure; 1196 1197 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref); 1198 rcu_assign_pointer(sfn->leaf, 1199 info->nl_net->ipv6.ip6_null_entry); 1200 sfn->fn_flags = RTN_ROOT; 1201 1202 /* Now add the first leaf node to new subtree */ 1203 1204 sn = fib6_add_1(info->nl_net, table, sfn, 1205 &rt->rt6i_src.addr, rt->rt6i_src.plen, 1206 offsetof(struct rt6_info, rt6i_src), 1207 allow_create, replace_required, extack); 1208 1209 if (IS_ERR(sn)) { 1210 /* If it is failed, discard just allocated 1211 root, and then (in failure) stale node 1212 in main tree. 1213 */ 1214 node_free_immediate(info->nl_net, sfn); 1215 err = PTR_ERR(sn); 1216 goto failure; 1217 } 1218 1219 /* Now link new subtree to main tree */ 1220 rcu_assign_pointer(sfn->parent, fn); 1221 rcu_assign_pointer(fn->subtree, sfn); 1222 } else { 1223 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn), 1224 &rt->rt6i_src.addr, rt->rt6i_src.plen, 1225 offsetof(struct rt6_info, rt6i_src), 1226 allow_create, replace_required, extack); 1227 1228 if (IS_ERR(sn)) { 1229 err = PTR_ERR(sn); 1230 goto failure; 1231 } 1232 } 1233 1234 if (!rcu_access_pointer(fn->leaf)) { 1235 if (fn->fn_flags & RTN_TL_ROOT) { 1236 /* put back null_entry for root node */ 1237 rcu_assign_pointer(fn->leaf, 1238 info->nl_net->ipv6.ip6_null_entry); 1239 } else { 1240 atomic_inc(&rt->rt6i_ref); 1241 rcu_assign_pointer(fn->leaf, rt); 1242 } 1243 } 1244 fn = sn; 1245 } 1246 #endif 1247 1248 err = fib6_add_rt2node(fn, rt, info, mxc, extack); 1249 if (!err) { 1250 __fib6_update_sernum_upto_root(rt, sernum); 1251 fib6_start_gc(info->nl_net, rt); 1252 } 1253 1254 out: 1255 if (err) { 1256 #ifdef CONFIG_IPV6_SUBTREES 1257 /* 1258 * If fib6_add_1 has cleared the old leaf pointer in the 1259 * super-tree leaf node we have to find a new one for it. 1260 */ 1261 if (pn != fn) { 1262 struct rt6_info *pn_leaf = 1263 rcu_dereference_protected(pn->leaf, 1264 lockdep_is_held(&table->tb6_lock)); 1265 if (pn_leaf == rt) { 1266 pn_leaf = NULL; 1267 RCU_INIT_POINTER(pn->leaf, NULL); 1268 atomic_dec(&rt->rt6i_ref); 1269 } 1270 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) { 1271 pn_leaf = fib6_find_prefix(info->nl_net, table, 1272 pn); 1273 #if RT6_DEBUG >= 2 1274 if (!pn_leaf) { 1275 WARN_ON(!pn_leaf); 1276 pn_leaf = 1277 info->nl_net->ipv6.ip6_null_entry; 1278 } 1279 #endif 1280 atomic_inc(&pn_leaf->rt6i_ref); 1281 rcu_assign_pointer(pn->leaf, pn_leaf); 1282 } 1283 } 1284 #endif 1285 goto failure; 1286 } 1287 return err; 1288 1289 failure: 1290 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if: 1291 * 1. fn is an intermediate node and we failed to add the new 1292 * route to it in both subtree creation failure and fib6_add_rt2node() 1293 * failure case. 1294 * 2. fn is the root node in the table and we fail to add the first 1295 * default route to it. 1296 */ 1297 if (fn && 1298 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) || 1299 (fn->fn_flags & RTN_TL_ROOT && 1300 !rcu_access_pointer(fn->leaf)))) 1301 fib6_repair_tree(info->nl_net, table, fn); 1302 /* Always release dst as dst->__refcnt is guaranteed 1303 * to be taken before entering this function 1304 */ 1305 dst_release_immediate(&rt->dst); 1306 return err; 1307 } 1308 1309 /* 1310 * Routing tree lookup 1311 * 1312 */ 1313 1314 struct lookup_args { 1315 int offset; /* key offset on rt6_info */ 1316 const struct in6_addr *addr; /* search key */ 1317 }; 1318 1319 static struct fib6_node *fib6_lookup_1(struct fib6_node *root, 1320 struct lookup_args *args) 1321 { 1322 struct fib6_node *fn; 1323 __be32 dir; 1324 1325 if (unlikely(args->offset == 0)) 1326 return NULL; 1327 1328 /* 1329 * Descend on a tree 1330 */ 1331 1332 fn = root; 1333 1334 for (;;) { 1335 struct fib6_node *next; 1336 1337 dir = addr_bit_set(args->addr, fn->fn_bit); 1338 1339 next = dir ? rcu_dereference(fn->right) : 1340 rcu_dereference(fn->left); 1341 1342 if (next) { 1343 fn = next; 1344 continue; 1345 } 1346 break; 1347 } 1348 1349 while (fn) { 1350 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1351 1352 if (subtree || fn->fn_flags & RTN_RTINFO) { 1353 struct rt6_info *leaf = rcu_dereference(fn->leaf); 1354 struct rt6key *key; 1355 1356 if (!leaf) 1357 goto backtrack; 1358 1359 key = (struct rt6key *) ((u8 *)leaf + args->offset); 1360 1361 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1362 #ifdef CONFIG_IPV6_SUBTREES 1363 if (subtree) { 1364 struct fib6_node *sfn; 1365 sfn = fib6_lookup_1(subtree, args + 1); 1366 if (!sfn) 1367 goto backtrack; 1368 fn = sfn; 1369 } 1370 #endif 1371 if (fn->fn_flags & RTN_RTINFO) 1372 return fn; 1373 } 1374 } 1375 backtrack: 1376 if (fn->fn_flags & RTN_ROOT) 1377 break; 1378 1379 fn = rcu_dereference(fn->parent); 1380 } 1381 1382 return NULL; 1383 } 1384 1385 /* called with rcu_read_lock() held 1386 */ 1387 struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr, 1388 const struct in6_addr *saddr) 1389 { 1390 struct fib6_node *fn; 1391 struct lookup_args args[] = { 1392 { 1393 .offset = offsetof(struct rt6_info, rt6i_dst), 1394 .addr = daddr, 1395 }, 1396 #ifdef CONFIG_IPV6_SUBTREES 1397 { 1398 .offset = offsetof(struct rt6_info, rt6i_src), 1399 .addr = saddr, 1400 }, 1401 #endif 1402 { 1403 .offset = 0, /* sentinel */ 1404 } 1405 }; 1406 1407 fn = fib6_lookup_1(root, daddr ? args : args + 1); 1408 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1409 fn = root; 1410 1411 return fn; 1412 } 1413 1414 /* 1415 * Get node with specified destination prefix (and source prefix, 1416 * if subtrees are used) 1417 * exact_match == true means we try to find fn with exact match of 1418 * the passed in prefix addr 1419 * exact_match == false means we try to find fn with longest prefix 1420 * match of the passed in prefix addr. This is useful for finding fn 1421 * for cached route as it will be stored in the exception table under 1422 * the node with longest prefix length. 1423 */ 1424 1425 1426 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1427 const struct in6_addr *addr, 1428 int plen, int offset, 1429 bool exact_match) 1430 { 1431 struct fib6_node *fn, *prev = NULL; 1432 1433 for (fn = root; fn ; ) { 1434 struct rt6_info *leaf = rcu_dereference(fn->leaf); 1435 struct rt6key *key; 1436 1437 /* This node is being deleted */ 1438 if (!leaf) { 1439 if (plen <= fn->fn_bit) 1440 goto out; 1441 else 1442 goto next; 1443 } 1444 1445 key = (struct rt6key *)((u8 *)leaf + offset); 1446 1447 /* 1448 * Prefix match 1449 */ 1450 if (plen < fn->fn_bit || 1451 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1452 goto out; 1453 1454 if (plen == fn->fn_bit) 1455 return fn; 1456 1457 prev = fn; 1458 1459 next: 1460 /* 1461 * We have more bits to go 1462 */ 1463 if (addr_bit_set(addr, fn->fn_bit)) 1464 fn = rcu_dereference(fn->right); 1465 else 1466 fn = rcu_dereference(fn->left); 1467 } 1468 out: 1469 if (exact_match) 1470 return NULL; 1471 else 1472 return prev; 1473 } 1474 1475 struct fib6_node *fib6_locate(struct fib6_node *root, 1476 const struct in6_addr *daddr, int dst_len, 1477 const struct in6_addr *saddr, int src_len, 1478 bool exact_match) 1479 { 1480 struct fib6_node *fn; 1481 1482 fn = fib6_locate_1(root, daddr, dst_len, 1483 offsetof(struct rt6_info, rt6i_dst), 1484 exact_match); 1485 1486 #ifdef CONFIG_IPV6_SUBTREES 1487 if (src_len) { 1488 WARN_ON(saddr == NULL); 1489 if (fn) { 1490 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1491 1492 if (subtree) { 1493 fn = fib6_locate_1(subtree, saddr, src_len, 1494 offsetof(struct rt6_info, rt6i_src), 1495 exact_match); 1496 } 1497 } 1498 } 1499 #endif 1500 1501 if (fn && fn->fn_flags & RTN_RTINFO) 1502 return fn; 1503 1504 return NULL; 1505 } 1506 1507 1508 /* 1509 * Deletion 1510 * 1511 */ 1512 1513 static struct rt6_info *fib6_find_prefix(struct net *net, 1514 struct fib6_table *table, 1515 struct fib6_node *fn) 1516 { 1517 struct fib6_node *child_left, *child_right; 1518 1519 if (fn->fn_flags & RTN_ROOT) 1520 return net->ipv6.ip6_null_entry; 1521 1522 while (fn) { 1523 child_left = rcu_dereference_protected(fn->left, 1524 lockdep_is_held(&table->tb6_lock)); 1525 child_right = rcu_dereference_protected(fn->right, 1526 lockdep_is_held(&table->tb6_lock)); 1527 if (child_left) 1528 return rcu_dereference_protected(child_left->leaf, 1529 lockdep_is_held(&table->tb6_lock)); 1530 if (child_right) 1531 return rcu_dereference_protected(child_right->leaf, 1532 lockdep_is_held(&table->tb6_lock)); 1533 1534 fn = FIB6_SUBTREE(fn); 1535 } 1536 return NULL; 1537 } 1538 1539 /* 1540 * Called to trim the tree of intermediate nodes when possible. "fn" 1541 * is the node we want to try and remove. 1542 * Need to own table->tb6_lock 1543 */ 1544 1545 static struct fib6_node *fib6_repair_tree(struct net *net, 1546 struct fib6_table *table, 1547 struct fib6_node *fn) 1548 { 1549 int children; 1550 int nstate; 1551 struct fib6_node *child; 1552 struct fib6_walker *w; 1553 int iter = 0; 1554 1555 /* Set fn->leaf to null_entry for root node. */ 1556 if (fn->fn_flags & RTN_TL_ROOT) { 1557 rcu_assign_pointer(fn->leaf, net->ipv6.ip6_null_entry); 1558 return fn; 1559 } 1560 1561 for (;;) { 1562 struct fib6_node *fn_r = rcu_dereference_protected(fn->right, 1563 lockdep_is_held(&table->tb6_lock)); 1564 struct fib6_node *fn_l = rcu_dereference_protected(fn->left, 1565 lockdep_is_held(&table->tb6_lock)); 1566 struct fib6_node *pn = rcu_dereference_protected(fn->parent, 1567 lockdep_is_held(&table->tb6_lock)); 1568 struct fib6_node *pn_r = rcu_dereference_protected(pn->right, 1569 lockdep_is_held(&table->tb6_lock)); 1570 struct fib6_node *pn_l = rcu_dereference_protected(pn->left, 1571 lockdep_is_held(&table->tb6_lock)); 1572 struct rt6_info *fn_leaf = rcu_dereference_protected(fn->leaf, 1573 lockdep_is_held(&table->tb6_lock)); 1574 struct rt6_info *pn_leaf = rcu_dereference_protected(pn->leaf, 1575 lockdep_is_held(&table->tb6_lock)); 1576 struct rt6_info *new_fn_leaf; 1577 1578 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1579 iter++; 1580 1581 WARN_ON(fn->fn_flags & RTN_RTINFO); 1582 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1583 WARN_ON(fn_leaf); 1584 1585 children = 0; 1586 child = NULL; 1587 if (fn_r) 1588 child = fn_r, children |= 1; 1589 if (fn_l) 1590 child = fn_l, children |= 2; 1591 1592 if (children == 3 || FIB6_SUBTREE(fn) 1593 #ifdef CONFIG_IPV6_SUBTREES 1594 /* Subtree root (i.e. fn) may have one child */ 1595 || (children && fn->fn_flags & RTN_ROOT) 1596 #endif 1597 ) { 1598 new_fn_leaf = fib6_find_prefix(net, table, fn); 1599 #if RT6_DEBUG >= 2 1600 if (!new_fn_leaf) { 1601 WARN_ON(!new_fn_leaf); 1602 new_fn_leaf = net->ipv6.ip6_null_entry; 1603 } 1604 #endif 1605 atomic_inc(&new_fn_leaf->rt6i_ref); 1606 rcu_assign_pointer(fn->leaf, new_fn_leaf); 1607 return pn; 1608 } 1609 1610 #ifdef CONFIG_IPV6_SUBTREES 1611 if (FIB6_SUBTREE(pn) == fn) { 1612 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1613 RCU_INIT_POINTER(pn->subtree, NULL); 1614 nstate = FWS_L; 1615 } else { 1616 WARN_ON(fn->fn_flags & RTN_ROOT); 1617 #endif 1618 if (pn_r == fn) 1619 rcu_assign_pointer(pn->right, child); 1620 else if (pn_l == fn) 1621 rcu_assign_pointer(pn->left, child); 1622 #if RT6_DEBUG >= 2 1623 else 1624 WARN_ON(1); 1625 #endif 1626 if (child) 1627 rcu_assign_pointer(child->parent, pn); 1628 nstate = FWS_R; 1629 #ifdef CONFIG_IPV6_SUBTREES 1630 } 1631 #endif 1632 1633 read_lock(&net->ipv6.fib6_walker_lock); 1634 FOR_WALKERS(net, w) { 1635 if (!child) { 1636 if (w->node == fn) { 1637 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1638 w->node = pn; 1639 w->state = nstate; 1640 } 1641 } else { 1642 if (w->node == fn) { 1643 w->node = child; 1644 if (children&2) { 1645 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1646 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1647 } else { 1648 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1649 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1650 } 1651 } 1652 } 1653 } 1654 read_unlock(&net->ipv6.fib6_walker_lock); 1655 1656 node_free(net, fn); 1657 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1658 return pn; 1659 1660 RCU_INIT_POINTER(pn->leaf, NULL); 1661 rt6_release(pn_leaf); 1662 fn = pn; 1663 } 1664 } 1665 1666 static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn, 1667 struct rt6_info __rcu **rtp, struct nl_info *info) 1668 { 1669 struct fib6_walker *w; 1670 struct rt6_info *rt = rcu_dereference_protected(*rtp, 1671 lockdep_is_held(&table->tb6_lock)); 1672 struct net *net = info->nl_net; 1673 1674 RT6_TRACE("fib6_del_route\n"); 1675 1676 WARN_ON_ONCE(rt->rt6i_flags & RTF_CACHE); 1677 1678 /* Unlink it */ 1679 *rtp = rt->rt6_next; 1680 rt->rt6i_node = NULL; 1681 net->ipv6.rt6_stats->fib_rt_entries--; 1682 net->ipv6.rt6_stats->fib_discarded_routes++; 1683 1684 /* Flush all cached dst in exception table */ 1685 rt6_flush_exceptions(rt); 1686 1687 /* Reset round-robin state, if necessary */ 1688 if (rcu_access_pointer(fn->rr_ptr) == rt) 1689 fn->rr_ptr = NULL; 1690 1691 /* Remove this entry from other siblings */ 1692 if (rt->rt6i_nsiblings) { 1693 struct rt6_info *sibling, *next_sibling; 1694 1695 list_for_each_entry_safe(sibling, next_sibling, 1696 &rt->rt6i_siblings, rt6i_siblings) 1697 sibling->rt6i_nsiblings--; 1698 rt->rt6i_nsiblings = 0; 1699 list_del_init(&rt->rt6i_siblings); 1700 rt6_multipath_rebalance(next_sibling); 1701 } 1702 1703 /* Adjust walkers */ 1704 read_lock(&net->ipv6.fib6_walker_lock); 1705 FOR_WALKERS(net, w) { 1706 if (w->state == FWS_C && w->leaf == rt) { 1707 RT6_TRACE("walker %p adjusted by delroute\n", w); 1708 w->leaf = rcu_dereference_protected(rt->rt6_next, 1709 lockdep_is_held(&table->tb6_lock)); 1710 if (!w->leaf) 1711 w->state = FWS_U; 1712 } 1713 } 1714 read_unlock(&net->ipv6.fib6_walker_lock); 1715 1716 /* If it was last route, call fib6_repair_tree() to: 1717 * 1. For root node, put back null_entry as how the table was created. 1718 * 2. For other nodes, expunge its radix tree node. 1719 */ 1720 if (!rcu_access_pointer(fn->leaf)) { 1721 if (!(fn->fn_flags & RTN_TL_ROOT)) { 1722 fn->fn_flags &= ~RTN_RTINFO; 1723 net->ipv6.rt6_stats->fib_route_nodes--; 1724 } 1725 fn = fib6_repair_tree(net, table, fn); 1726 } 1727 1728 fib6_purge_rt(rt, fn, net); 1729 1730 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL); 1731 if (!info->skip_notify) 1732 inet6_rt_notify(RTM_DELROUTE, rt, info, 0); 1733 rt6_release(rt); 1734 } 1735 1736 /* Need to own table->tb6_lock */ 1737 int fib6_del(struct rt6_info *rt, struct nl_info *info) 1738 { 1739 struct fib6_node *fn = rcu_dereference_protected(rt->rt6i_node, 1740 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 1741 struct fib6_table *table = rt->rt6i_table; 1742 struct net *net = info->nl_net; 1743 struct rt6_info __rcu **rtp; 1744 struct rt6_info __rcu **rtp_next; 1745 1746 #if RT6_DEBUG >= 2 1747 if (rt->dst.obsolete > 0) { 1748 WARN_ON(fn); 1749 return -ENOENT; 1750 } 1751 #endif 1752 if (!fn || rt == net->ipv6.ip6_null_entry) 1753 return -ENOENT; 1754 1755 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1756 1757 /* remove cached dst from exception table */ 1758 if (rt->rt6i_flags & RTF_CACHE) 1759 return rt6_remove_exception_rt(rt); 1760 1761 /* 1762 * Walk the leaf entries looking for ourself 1763 */ 1764 1765 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) { 1766 struct rt6_info *cur = rcu_dereference_protected(*rtp, 1767 lockdep_is_held(&table->tb6_lock)); 1768 if (rt == cur) { 1769 fib6_del_route(table, fn, rtp, info); 1770 return 0; 1771 } 1772 rtp_next = &cur->rt6_next; 1773 } 1774 return -ENOENT; 1775 } 1776 1777 /* 1778 * Tree traversal function. 1779 * 1780 * Certainly, it is not interrupt safe. 1781 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1782 * It means, that we can modify tree during walking 1783 * and use this function for garbage collection, clone pruning, 1784 * cleaning tree when a device goes down etc. etc. 1785 * 1786 * It guarantees that every node will be traversed, 1787 * and that it will be traversed only once. 1788 * 1789 * Callback function w->func may return: 1790 * 0 -> continue walking. 1791 * positive value -> walking is suspended (used by tree dumps, 1792 * and probably by gc, if it will be split to several slices) 1793 * negative value -> terminate walking. 1794 * 1795 * The function itself returns: 1796 * 0 -> walk is complete. 1797 * >0 -> walk is incomplete (i.e. suspended) 1798 * <0 -> walk is terminated by an error. 1799 * 1800 * This function is called with tb6_lock held. 1801 */ 1802 1803 static int fib6_walk_continue(struct fib6_walker *w) 1804 { 1805 struct fib6_node *fn, *pn, *left, *right; 1806 1807 /* w->root should always be table->tb6_root */ 1808 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT)); 1809 1810 for (;;) { 1811 fn = w->node; 1812 if (!fn) 1813 return 0; 1814 1815 switch (w->state) { 1816 #ifdef CONFIG_IPV6_SUBTREES 1817 case FWS_S: 1818 if (FIB6_SUBTREE(fn)) { 1819 w->node = FIB6_SUBTREE(fn); 1820 continue; 1821 } 1822 w->state = FWS_L; 1823 #endif 1824 /* fall through */ 1825 case FWS_L: 1826 left = rcu_dereference_protected(fn->left, 1); 1827 if (left) { 1828 w->node = left; 1829 w->state = FWS_INIT; 1830 continue; 1831 } 1832 w->state = FWS_R; 1833 /* fall through */ 1834 case FWS_R: 1835 right = rcu_dereference_protected(fn->right, 1); 1836 if (right) { 1837 w->node = right; 1838 w->state = FWS_INIT; 1839 continue; 1840 } 1841 w->state = FWS_C; 1842 w->leaf = rcu_dereference_protected(fn->leaf, 1); 1843 /* fall through */ 1844 case FWS_C: 1845 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1846 int err; 1847 1848 if (w->skip) { 1849 w->skip--; 1850 goto skip; 1851 } 1852 1853 err = w->func(w); 1854 if (err) 1855 return err; 1856 1857 w->count++; 1858 continue; 1859 } 1860 skip: 1861 w->state = FWS_U; 1862 /* fall through */ 1863 case FWS_U: 1864 if (fn == w->root) 1865 return 0; 1866 pn = rcu_dereference_protected(fn->parent, 1); 1867 left = rcu_dereference_protected(pn->left, 1); 1868 right = rcu_dereference_protected(pn->right, 1); 1869 w->node = pn; 1870 #ifdef CONFIG_IPV6_SUBTREES 1871 if (FIB6_SUBTREE(pn) == fn) { 1872 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1873 w->state = FWS_L; 1874 continue; 1875 } 1876 #endif 1877 if (left == fn) { 1878 w->state = FWS_R; 1879 continue; 1880 } 1881 if (right == fn) { 1882 w->state = FWS_C; 1883 w->leaf = rcu_dereference_protected(w->node->leaf, 1); 1884 continue; 1885 } 1886 #if RT6_DEBUG >= 2 1887 WARN_ON(1); 1888 #endif 1889 } 1890 } 1891 } 1892 1893 static int fib6_walk(struct net *net, struct fib6_walker *w) 1894 { 1895 int res; 1896 1897 w->state = FWS_INIT; 1898 w->node = w->root; 1899 1900 fib6_walker_link(net, w); 1901 res = fib6_walk_continue(w); 1902 if (res <= 0) 1903 fib6_walker_unlink(net, w); 1904 return res; 1905 } 1906 1907 static int fib6_clean_node(struct fib6_walker *w) 1908 { 1909 int res; 1910 struct rt6_info *rt; 1911 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 1912 struct nl_info info = { 1913 .nl_net = c->net, 1914 }; 1915 1916 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 1917 w->node->fn_sernum != c->sernum) 1918 w->node->fn_sernum = c->sernum; 1919 1920 if (!c->func) { 1921 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 1922 w->leaf = NULL; 1923 return 0; 1924 } 1925 1926 for_each_fib6_walker_rt(w) { 1927 res = c->func(rt, c->arg); 1928 if (res == -1) { 1929 w->leaf = rt; 1930 res = fib6_del(rt, &info); 1931 if (res) { 1932 #if RT6_DEBUG >= 2 1933 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 1934 __func__, rt, 1935 rcu_access_pointer(rt->rt6i_node), 1936 res); 1937 #endif 1938 continue; 1939 } 1940 return 0; 1941 } else if (res == -2) { 1942 if (WARN_ON(!rt->rt6i_nsiblings)) 1943 continue; 1944 rt = list_last_entry(&rt->rt6i_siblings, 1945 struct rt6_info, rt6i_siblings); 1946 continue; 1947 } 1948 WARN_ON(res != 0); 1949 } 1950 w->leaf = rt; 1951 return 0; 1952 } 1953 1954 /* 1955 * Convenient frontend to tree walker. 1956 * 1957 * func is called on each route. 1958 * It may return -2 -> skip multipath route. 1959 * -1 -> delete this route. 1960 * 0 -> continue walking 1961 */ 1962 1963 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 1964 int (*func)(struct rt6_info *, void *arg), 1965 int sernum, void *arg) 1966 { 1967 struct fib6_cleaner c; 1968 1969 c.w.root = root; 1970 c.w.func = fib6_clean_node; 1971 c.w.count = 0; 1972 c.w.skip = 0; 1973 c.func = func; 1974 c.sernum = sernum; 1975 c.arg = arg; 1976 c.net = net; 1977 1978 fib6_walk(net, &c.w); 1979 } 1980 1981 static void __fib6_clean_all(struct net *net, 1982 int (*func)(struct rt6_info *, void *), 1983 int sernum, void *arg) 1984 { 1985 struct fib6_table *table; 1986 struct hlist_head *head; 1987 unsigned int h; 1988 1989 rcu_read_lock(); 1990 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 1991 head = &net->ipv6.fib_table_hash[h]; 1992 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 1993 spin_lock_bh(&table->tb6_lock); 1994 fib6_clean_tree(net, &table->tb6_root, 1995 func, sernum, arg); 1996 spin_unlock_bh(&table->tb6_lock); 1997 } 1998 } 1999 rcu_read_unlock(); 2000 } 2001 2002 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *), 2003 void *arg) 2004 { 2005 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg); 2006 } 2007 2008 static void fib6_flush_trees(struct net *net) 2009 { 2010 int new_sernum = fib6_new_sernum(net); 2011 2012 __fib6_clean_all(net, NULL, new_sernum, NULL); 2013 } 2014 2015 /* 2016 * Garbage collection 2017 */ 2018 2019 static int fib6_age(struct rt6_info *rt, void *arg) 2020 { 2021 struct fib6_gc_args *gc_args = arg; 2022 unsigned long now = jiffies; 2023 2024 /* 2025 * check addrconf expiration here. 2026 * Routes are expired even if they are in use. 2027 */ 2028 2029 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) { 2030 if (time_after(now, rt->dst.expires)) { 2031 RT6_TRACE("expiring %p\n", rt); 2032 return -1; 2033 } 2034 gc_args->more++; 2035 } 2036 2037 /* Also age clones in the exception table. 2038 * Note, that clones are aged out 2039 * only if they are not in use now. 2040 */ 2041 rt6_age_exceptions(rt, gc_args, now); 2042 2043 return 0; 2044 } 2045 2046 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 2047 { 2048 struct fib6_gc_args gc_args; 2049 unsigned long now; 2050 2051 if (force) { 2052 spin_lock_bh(&net->ipv6.fib6_gc_lock); 2053 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) { 2054 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 2055 return; 2056 } 2057 gc_args.timeout = expires ? (int)expires : 2058 net->ipv6.sysctl.ip6_rt_gc_interval; 2059 gc_args.more = 0; 2060 2061 fib6_clean_all(net, fib6_age, &gc_args); 2062 now = jiffies; 2063 net->ipv6.ip6_rt_last_gc = now; 2064 2065 if (gc_args.more) 2066 mod_timer(&net->ipv6.ip6_fib_timer, 2067 round_jiffies(now 2068 + net->ipv6.sysctl.ip6_rt_gc_interval)); 2069 else 2070 del_timer(&net->ipv6.ip6_fib_timer); 2071 spin_unlock_bh(&net->ipv6.fib6_gc_lock); 2072 } 2073 2074 static void fib6_gc_timer_cb(struct timer_list *t) 2075 { 2076 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer); 2077 2078 fib6_run_gc(0, arg, true); 2079 } 2080 2081 static int __net_init fib6_net_init(struct net *net) 2082 { 2083 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 2084 int err; 2085 2086 err = fib6_notifier_init(net); 2087 if (err) 2088 return err; 2089 2090 spin_lock_init(&net->ipv6.fib6_gc_lock); 2091 rwlock_init(&net->ipv6.fib6_walker_lock); 2092 INIT_LIST_HEAD(&net->ipv6.fib6_walkers); 2093 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0); 2094 2095 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 2096 if (!net->ipv6.rt6_stats) 2097 goto out_timer; 2098 2099 /* Avoid false sharing : Use at least a full cache line */ 2100 size = max_t(size_t, size, L1_CACHE_BYTES); 2101 2102 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 2103 if (!net->ipv6.fib_table_hash) 2104 goto out_rt6_stats; 2105 2106 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 2107 GFP_KERNEL); 2108 if (!net->ipv6.fib6_main_tbl) 2109 goto out_fib_table_hash; 2110 2111 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 2112 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf, 2113 net->ipv6.ip6_null_entry); 2114 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 2115 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2116 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 2117 2118 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2119 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 2120 GFP_KERNEL); 2121 if (!net->ipv6.fib6_local_tbl) 2122 goto out_fib6_main_tbl; 2123 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 2124 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf, 2125 net->ipv6.ip6_null_entry); 2126 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 2127 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2128 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 2129 #endif 2130 fib6_tables_init(net); 2131 2132 return 0; 2133 2134 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2135 out_fib6_main_tbl: 2136 kfree(net->ipv6.fib6_main_tbl); 2137 #endif 2138 out_fib_table_hash: 2139 kfree(net->ipv6.fib_table_hash); 2140 out_rt6_stats: 2141 kfree(net->ipv6.rt6_stats); 2142 out_timer: 2143 fib6_notifier_exit(net); 2144 return -ENOMEM; 2145 } 2146 2147 static void fib6_net_exit(struct net *net) 2148 { 2149 unsigned int i; 2150 2151 del_timer_sync(&net->ipv6.ip6_fib_timer); 2152 2153 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) { 2154 struct hlist_head *head = &net->ipv6.fib_table_hash[i]; 2155 struct hlist_node *tmp; 2156 struct fib6_table *tb; 2157 2158 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) { 2159 hlist_del(&tb->tb6_hlist); 2160 fib6_free_table(tb); 2161 } 2162 } 2163 2164 kfree(net->ipv6.fib_table_hash); 2165 kfree(net->ipv6.rt6_stats); 2166 fib6_notifier_exit(net); 2167 } 2168 2169 static struct pernet_operations fib6_net_ops = { 2170 .init = fib6_net_init, 2171 .exit = fib6_net_exit, 2172 }; 2173 2174 int __init fib6_init(void) 2175 { 2176 int ret = -ENOMEM; 2177 2178 fib6_node_kmem = kmem_cache_create("fib6_nodes", 2179 sizeof(struct fib6_node), 2180 0, SLAB_HWCACHE_ALIGN, 2181 NULL); 2182 if (!fib6_node_kmem) 2183 goto out; 2184 2185 ret = register_pernet_subsys(&fib6_net_ops); 2186 if (ret) 2187 goto out_kmem_cache_create; 2188 2189 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL, 2190 inet6_dump_fib, 0); 2191 if (ret) 2192 goto out_unregister_subsys; 2193 2194 __fib6_flush_trees = fib6_flush_trees; 2195 out: 2196 return ret; 2197 2198 out_unregister_subsys: 2199 unregister_pernet_subsys(&fib6_net_ops); 2200 out_kmem_cache_create: 2201 kmem_cache_destroy(fib6_node_kmem); 2202 goto out; 2203 } 2204 2205 void fib6_gc_cleanup(void) 2206 { 2207 unregister_pernet_subsys(&fib6_net_ops); 2208 kmem_cache_destroy(fib6_node_kmem); 2209 } 2210 2211 #ifdef CONFIG_PROC_FS 2212 2213 struct ipv6_route_iter { 2214 struct seq_net_private p; 2215 struct fib6_walker w; 2216 loff_t skip; 2217 struct fib6_table *tbl; 2218 int sernum; 2219 }; 2220 2221 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 2222 { 2223 struct rt6_info *rt = v; 2224 struct ipv6_route_iter *iter = seq->private; 2225 2226 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen); 2227 2228 #ifdef CONFIG_IPV6_SUBTREES 2229 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen); 2230 #else 2231 seq_puts(seq, "00000000000000000000000000000000 00 "); 2232 #endif 2233 if (rt->rt6i_flags & RTF_GATEWAY) 2234 seq_printf(seq, "%pi6", &rt->rt6i_gateway); 2235 else 2236 seq_puts(seq, "00000000000000000000000000000000"); 2237 2238 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 2239 rt->rt6i_metric, atomic_read(&rt->dst.__refcnt), 2240 rt->dst.__use, rt->rt6i_flags, 2241 rt->dst.dev ? rt->dst.dev->name : ""); 2242 iter->w.leaf = NULL; 2243 return 0; 2244 } 2245 2246 static int ipv6_route_yield(struct fib6_walker *w) 2247 { 2248 struct ipv6_route_iter *iter = w->args; 2249 2250 if (!iter->skip) 2251 return 1; 2252 2253 do { 2254 iter->w.leaf = rcu_dereference_protected( 2255 iter->w.leaf->rt6_next, 2256 lockdep_is_held(&iter->tbl->tb6_lock)); 2257 iter->skip--; 2258 if (!iter->skip && iter->w.leaf) 2259 return 1; 2260 } while (iter->w.leaf); 2261 2262 return 0; 2263 } 2264 2265 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter, 2266 struct net *net) 2267 { 2268 memset(&iter->w, 0, sizeof(iter->w)); 2269 iter->w.func = ipv6_route_yield; 2270 iter->w.root = &iter->tbl->tb6_root; 2271 iter->w.state = FWS_INIT; 2272 iter->w.node = iter->w.root; 2273 iter->w.args = iter; 2274 iter->sernum = iter->w.root->fn_sernum; 2275 INIT_LIST_HEAD(&iter->w.lh); 2276 fib6_walker_link(net, &iter->w); 2277 } 2278 2279 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 2280 struct net *net) 2281 { 2282 unsigned int h; 2283 struct hlist_node *node; 2284 2285 if (tbl) { 2286 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 2287 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 2288 } else { 2289 h = 0; 2290 node = NULL; 2291 } 2292 2293 while (!node && h < FIB6_TABLE_HASHSZ) { 2294 node = rcu_dereference_bh( 2295 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 2296 } 2297 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 2298 } 2299 2300 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 2301 { 2302 if (iter->sernum != iter->w.root->fn_sernum) { 2303 iter->sernum = iter->w.root->fn_sernum; 2304 iter->w.state = FWS_INIT; 2305 iter->w.node = iter->w.root; 2306 WARN_ON(iter->w.skip); 2307 iter->w.skip = iter->w.count; 2308 } 2309 } 2310 2311 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2312 { 2313 int r; 2314 struct rt6_info *n; 2315 struct net *net = seq_file_net(seq); 2316 struct ipv6_route_iter *iter = seq->private; 2317 2318 if (!v) 2319 goto iter_table; 2320 2321 n = rcu_dereference_bh(((struct rt6_info *)v)->rt6_next); 2322 if (n) { 2323 ++*pos; 2324 return n; 2325 } 2326 2327 iter_table: 2328 ipv6_route_check_sernum(iter); 2329 spin_lock_bh(&iter->tbl->tb6_lock); 2330 r = fib6_walk_continue(&iter->w); 2331 spin_unlock_bh(&iter->tbl->tb6_lock); 2332 if (r > 0) { 2333 if (v) 2334 ++*pos; 2335 return iter->w.leaf; 2336 } else if (r < 0) { 2337 fib6_walker_unlink(net, &iter->w); 2338 return NULL; 2339 } 2340 fib6_walker_unlink(net, &iter->w); 2341 2342 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 2343 if (!iter->tbl) 2344 return NULL; 2345 2346 ipv6_route_seq_setup_walk(iter, net); 2347 goto iter_table; 2348 } 2349 2350 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 2351 __acquires(RCU_BH) 2352 { 2353 struct net *net = seq_file_net(seq); 2354 struct ipv6_route_iter *iter = seq->private; 2355 2356 rcu_read_lock_bh(); 2357 iter->tbl = ipv6_route_seq_next_table(NULL, net); 2358 iter->skip = *pos; 2359 2360 if (iter->tbl) { 2361 ipv6_route_seq_setup_walk(iter, net); 2362 return ipv6_route_seq_next(seq, NULL, pos); 2363 } else { 2364 return NULL; 2365 } 2366 } 2367 2368 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 2369 { 2370 struct fib6_walker *w = &iter->w; 2371 return w->node && !(w->state == FWS_U && w->node == w->root); 2372 } 2373 2374 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2375 __releases(RCU_BH) 2376 { 2377 struct net *net = seq_file_net(seq); 2378 struct ipv6_route_iter *iter = seq->private; 2379 2380 if (ipv6_route_iter_active(iter)) 2381 fib6_walker_unlink(net, &iter->w); 2382 2383 rcu_read_unlock_bh(); 2384 } 2385 2386 static const struct seq_operations ipv6_route_seq_ops = { 2387 .start = ipv6_route_seq_start, 2388 .next = ipv6_route_seq_next, 2389 .stop = ipv6_route_seq_stop, 2390 .show = ipv6_route_seq_show 2391 }; 2392 2393 int ipv6_route_open(struct inode *inode, struct file *file) 2394 { 2395 return seq_open_net(inode, file, &ipv6_route_seq_ops, 2396 sizeof(struct ipv6_route_iter)); 2397 } 2398 2399 #endif /* CONFIG_PROC_FS */ 2400