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 #define RT6_DEBUG 2 42 43 #if RT6_DEBUG >= 3 44 #define RT6_TRACE(x...) pr_debug(x) 45 #else 46 #define RT6_TRACE(x...) do { ; } while (0) 47 #endif 48 49 static struct kmem_cache *fib6_node_kmem __read_mostly; 50 51 struct fib6_cleaner { 52 struct fib6_walker w; 53 struct net *net; 54 int (*func)(struct rt6_info *, void *arg); 55 int sernum; 56 void *arg; 57 }; 58 59 #ifdef CONFIG_IPV6_SUBTREES 60 #define FWS_INIT FWS_S 61 #else 62 #define FWS_INIT FWS_L 63 #endif 64 65 static void fib6_prune_clones(struct net *net, struct fib6_node *fn); 66 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn); 67 static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn); 68 static int fib6_walk(struct net *net, struct fib6_walker *w); 69 static int fib6_walk_continue(struct fib6_walker *w); 70 71 /* 72 * A routing update causes an increase of the serial number on the 73 * affected subtree. This allows for cached routes to be asynchronously 74 * tested when modifications are made to the destination cache as a 75 * result of redirects, path MTU changes, etc. 76 */ 77 78 static void fib6_gc_timer_cb(unsigned long arg); 79 80 #define FOR_WALKERS(net, w) \ 81 list_for_each_entry(w, &(net)->ipv6.fib6_walkers, lh) 82 83 static void fib6_walker_link(struct net *net, struct fib6_walker *w) 84 { 85 write_lock_bh(&net->ipv6.fib6_walker_lock); 86 list_add(&w->lh, &net->ipv6.fib6_walkers); 87 write_unlock_bh(&net->ipv6.fib6_walker_lock); 88 } 89 90 static void fib6_walker_unlink(struct net *net, struct fib6_walker *w) 91 { 92 write_lock_bh(&net->ipv6.fib6_walker_lock); 93 list_del(&w->lh); 94 write_unlock_bh(&net->ipv6.fib6_walker_lock); 95 } 96 97 static int fib6_new_sernum(struct net *net) 98 { 99 int new, old; 100 101 do { 102 old = atomic_read(&net->ipv6.fib6_sernum); 103 new = old < INT_MAX ? old + 1 : 1; 104 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum, 105 old, new) != old); 106 return new; 107 } 108 109 enum { 110 FIB6_NO_SERNUM_CHANGE = 0, 111 }; 112 113 /* 114 * Auxiliary address test functions for the radix tree. 115 * 116 * These assume a 32bit processor (although it will work on 117 * 64bit processors) 118 */ 119 120 /* 121 * test bit 122 */ 123 #if defined(__LITTLE_ENDIAN) 124 # define BITOP_BE32_SWIZZLE (0x1F & ~7) 125 #else 126 # define BITOP_BE32_SWIZZLE 0 127 #endif 128 129 static __be32 addr_bit_set(const void *token, int fn_bit) 130 { 131 const __be32 *addr = token; 132 /* 133 * Here, 134 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f) 135 * is optimized version of 136 * htonl(1 << ((~fn_bit)&0x1F)) 137 * See include/asm-generic/bitops/le.h. 138 */ 139 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) & 140 addr[fn_bit >> 5]; 141 } 142 143 static struct fib6_node *node_alloc(void) 144 { 145 struct fib6_node *fn; 146 147 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); 148 149 return fn; 150 } 151 152 static void node_free_immediate(struct fib6_node *fn) 153 { 154 kmem_cache_free(fib6_node_kmem, fn); 155 } 156 157 static void node_free_rcu(struct rcu_head *head) 158 { 159 struct fib6_node *fn = container_of(head, struct fib6_node, rcu); 160 161 kmem_cache_free(fib6_node_kmem, fn); 162 } 163 164 static void node_free(struct fib6_node *fn) 165 { 166 call_rcu(&fn->rcu, node_free_rcu); 167 } 168 169 void rt6_free_pcpu(struct rt6_info *non_pcpu_rt) 170 { 171 int cpu; 172 173 if (!non_pcpu_rt->rt6i_pcpu) 174 return; 175 176 for_each_possible_cpu(cpu) { 177 struct rt6_info **ppcpu_rt; 178 struct rt6_info *pcpu_rt; 179 180 ppcpu_rt = per_cpu_ptr(non_pcpu_rt->rt6i_pcpu, cpu); 181 pcpu_rt = *ppcpu_rt; 182 if (pcpu_rt) { 183 dst_dev_put(&pcpu_rt->dst); 184 dst_release(&pcpu_rt->dst); 185 *ppcpu_rt = NULL; 186 } 187 } 188 189 free_percpu(non_pcpu_rt->rt6i_pcpu); 190 non_pcpu_rt->rt6i_pcpu = NULL; 191 } 192 EXPORT_SYMBOL_GPL(rt6_free_pcpu); 193 194 static void fib6_free_table(struct fib6_table *table) 195 { 196 inetpeer_invalidate_tree(&table->tb6_peers); 197 kfree(table); 198 } 199 200 static void fib6_link_table(struct net *net, struct fib6_table *tb) 201 { 202 unsigned int h; 203 204 /* 205 * Initialize table lock at a single place to give lockdep a key, 206 * tables aren't visible prior to being linked to the list. 207 */ 208 rwlock_init(&tb->tb6_lock); 209 210 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 211 212 /* 213 * No protection necessary, this is the only list mutatation 214 * operation, tables never disappear once they exist. 215 */ 216 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 217 } 218 219 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 220 221 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 222 { 223 struct fib6_table *table; 224 225 table = kzalloc(sizeof(*table), GFP_ATOMIC); 226 if (table) { 227 table->tb6_id = id; 228 table->tb6_root.leaf = net->ipv6.ip6_null_entry; 229 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 230 inet_peer_base_init(&table->tb6_peers); 231 } 232 233 return table; 234 } 235 236 struct fib6_table *fib6_new_table(struct net *net, u32 id) 237 { 238 struct fib6_table *tb; 239 240 if (id == 0) 241 id = RT6_TABLE_MAIN; 242 tb = fib6_get_table(net, id); 243 if (tb) 244 return tb; 245 246 tb = fib6_alloc_table(net, id); 247 if (tb) 248 fib6_link_table(net, tb); 249 250 return tb; 251 } 252 EXPORT_SYMBOL_GPL(fib6_new_table); 253 254 struct fib6_table *fib6_get_table(struct net *net, u32 id) 255 { 256 struct fib6_table *tb; 257 struct hlist_head *head; 258 unsigned int h; 259 260 if (id == 0) 261 id = RT6_TABLE_MAIN; 262 h = id & (FIB6_TABLE_HASHSZ - 1); 263 rcu_read_lock(); 264 head = &net->ipv6.fib_table_hash[h]; 265 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 266 if (tb->tb6_id == id) { 267 rcu_read_unlock(); 268 return tb; 269 } 270 } 271 rcu_read_unlock(); 272 273 return NULL; 274 } 275 EXPORT_SYMBOL_GPL(fib6_get_table); 276 277 static void __net_init fib6_tables_init(struct net *net) 278 { 279 fib6_link_table(net, net->ipv6.fib6_main_tbl); 280 fib6_link_table(net, net->ipv6.fib6_local_tbl); 281 } 282 #else 283 284 struct fib6_table *fib6_new_table(struct net *net, u32 id) 285 { 286 return fib6_get_table(net, id); 287 } 288 289 struct fib6_table *fib6_get_table(struct net *net, u32 id) 290 { 291 return net->ipv6.fib6_main_tbl; 292 } 293 294 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 295 int flags, pol_lookup_t lookup) 296 { 297 struct rt6_info *rt; 298 299 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, flags); 300 if (rt->dst.error == -EAGAIN) { 301 ip6_rt_put(rt); 302 rt = net->ipv6.ip6_null_entry; 303 dst_hold(&rt->dst); 304 } 305 306 return &rt->dst; 307 } 308 309 static void __net_init fib6_tables_init(struct net *net) 310 { 311 fib6_link_table(net, net->ipv6.fib6_main_tbl); 312 } 313 314 #endif 315 316 unsigned int fib6_tables_seq_read(struct net *net) 317 { 318 unsigned int h, fib_seq = 0; 319 320 rcu_read_lock(); 321 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 322 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 323 struct fib6_table *tb; 324 325 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 326 read_lock_bh(&tb->tb6_lock); 327 fib_seq += tb->fib_seq; 328 read_unlock_bh(&tb->tb6_lock); 329 } 330 } 331 rcu_read_unlock(); 332 333 return fib_seq; 334 } 335 336 static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net, 337 enum fib_event_type event_type, 338 struct rt6_info *rt) 339 { 340 struct fib6_entry_notifier_info info = { 341 .rt = rt, 342 }; 343 344 return call_fib6_notifier(nb, net, event_type, &info.info); 345 } 346 347 static int call_fib6_entry_notifiers(struct net *net, 348 enum fib_event_type event_type, 349 struct rt6_info *rt) 350 { 351 struct fib6_entry_notifier_info info = { 352 .rt = rt, 353 }; 354 355 rt->rt6i_table->fib_seq++; 356 return call_fib6_notifiers(net, event_type, &info.info); 357 } 358 359 struct fib6_dump_arg { 360 struct net *net; 361 struct notifier_block *nb; 362 }; 363 364 static void fib6_rt_dump(struct rt6_info *rt, struct fib6_dump_arg *arg) 365 { 366 if (rt == arg->net->ipv6.ip6_null_entry) 367 return; 368 call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt); 369 } 370 371 static int fib6_node_dump(struct fib6_walker *w) 372 { 373 struct rt6_info *rt; 374 375 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) 376 fib6_rt_dump(rt, w->args); 377 w->leaf = NULL; 378 return 0; 379 } 380 381 static void fib6_table_dump(struct net *net, struct fib6_table *tb, 382 struct fib6_walker *w) 383 { 384 w->root = &tb->tb6_root; 385 read_lock_bh(&tb->tb6_lock); 386 fib6_walk(net, w); 387 read_unlock_bh(&tb->tb6_lock); 388 } 389 390 /* Called with rcu_read_lock() */ 391 int fib6_tables_dump(struct net *net, struct notifier_block *nb) 392 { 393 struct fib6_dump_arg arg; 394 struct fib6_walker *w; 395 unsigned int h; 396 397 w = kzalloc(sizeof(*w), GFP_ATOMIC); 398 if (!w) 399 return -ENOMEM; 400 401 w->func = fib6_node_dump; 402 arg.net = net; 403 arg.nb = nb; 404 w->args = &arg; 405 406 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 407 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 408 struct fib6_table *tb; 409 410 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 411 fib6_table_dump(net, tb, w); 412 } 413 414 kfree(w); 415 416 return 0; 417 } 418 419 static int fib6_dump_node(struct fib6_walker *w) 420 { 421 int res; 422 struct rt6_info *rt; 423 424 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 425 res = rt6_dump_route(rt, w->args); 426 if (res < 0) { 427 /* Frame is full, suspend walking */ 428 w->leaf = rt; 429 return 1; 430 } 431 432 /* Multipath routes are dumped in one route with the 433 * RTA_MULTIPATH attribute. Jump 'rt' to point to the 434 * last sibling of this route (no need to dump the 435 * sibling routes again) 436 */ 437 if (rt->rt6i_nsiblings) 438 rt = list_last_entry(&rt->rt6i_siblings, 439 struct rt6_info, 440 rt6i_siblings); 441 } 442 w->leaf = NULL; 443 return 0; 444 } 445 446 static void fib6_dump_end(struct netlink_callback *cb) 447 { 448 struct net *net = sock_net(cb->skb->sk); 449 struct fib6_walker *w = (void *)cb->args[2]; 450 451 if (w) { 452 if (cb->args[4]) { 453 cb->args[4] = 0; 454 fib6_walker_unlink(net, w); 455 } 456 cb->args[2] = 0; 457 kfree(w); 458 } 459 cb->done = (void *)cb->args[3]; 460 cb->args[1] = 3; 461 } 462 463 static int fib6_dump_done(struct netlink_callback *cb) 464 { 465 fib6_dump_end(cb); 466 return cb->done ? cb->done(cb) : 0; 467 } 468 469 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 470 struct netlink_callback *cb) 471 { 472 struct net *net = sock_net(skb->sk); 473 struct fib6_walker *w; 474 int res; 475 476 w = (void *)cb->args[2]; 477 w->root = &table->tb6_root; 478 479 if (cb->args[4] == 0) { 480 w->count = 0; 481 w->skip = 0; 482 483 read_lock_bh(&table->tb6_lock); 484 res = fib6_walk(net, w); 485 read_unlock_bh(&table->tb6_lock); 486 if (res > 0) { 487 cb->args[4] = 1; 488 cb->args[5] = w->root->fn_sernum; 489 } 490 } else { 491 if (cb->args[5] != w->root->fn_sernum) { 492 /* Begin at the root if the tree changed */ 493 cb->args[5] = w->root->fn_sernum; 494 w->state = FWS_INIT; 495 w->node = w->root; 496 w->skip = w->count; 497 } else 498 w->skip = 0; 499 500 read_lock_bh(&table->tb6_lock); 501 res = fib6_walk_continue(w); 502 read_unlock_bh(&table->tb6_lock); 503 if (res <= 0) { 504 fib6_walker_unlink(net, w); 505 cb->args[4] = 0; 506 } 507 } 508 509 return res; 510 } 511 512 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 513 { 514 struct net *net = sock_net(skb->sk); 515 unsigned int h, s_h; 516 unsigned int e = 0, s_e; 517 struct rt6_rtnl_dump_arg arg; 518 struct fib6_walker *w; 519 struct fib6_table *tb; 520 struct hlist_head *head; 521 int res = 0; 522 523 s_h = cb->args[0]; 524 s_e = cb->args[1]; 525 526 w = (void *)cb->args[2]; 527 if (!w) { 528 /* New dump: 529 * 530 * 1. hook callback destructor. 531 */ 532 cb->args[3] = (long)cb->done; 533 cb->done = fib6_dump_done; 534 535 /* 536 * 2. allocate and initialize walker. 537 */ 538 w = kzalloc(sizeof(*w), GFP_ATOMIC); 539 if (!w) 540 return -ENOMEM; 541 w->func = fib6_dump_node; 542 cb->args[2] = (long)w; 543 } 544 545 arg.skb = skb; 546 arg.cb = cb; 547 arg.net = net; 548 w->args = &arg; 549 550 rcu_read_lock(); 551 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 552 e = 0; 553 head = &net->ipv6.fib_table_hash[h]; 554 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 555 if (e < s_e) 556 goto next; 557 res = fib6_dump_table(tb, skb, cb); 558 if (res != 0) 559 goto out; 560 next: 561 e++; 562 } 563 } 564 out: 565 rcu_read_unlock(); 566 cb->args[1] = e; 567 cb->args[0] = h; 568 569 res = res < 0 ? res : skb->len; 570 if (res <= 0) 571 fib6_dump_end(cb); 572 return res; 573 } 574 575 /* 576 * Routing Table 577 * 578 * return the appropriate node for a routing tree "add" operation 579 * by either creating and inserting or by returning an existing 580 * node. 581 */ 582 583 static struct fib6_node *fib6_add_1(struct fib6_node *root, 584 struct in6_addr *addr, int plen, 585 int offset, int allow_create, 586 int replace_required, int sernum, 587 struct netlink_ext_ack *extack) 588 { 589 struct fib6_node *fn, *in, *ln; 590 struct fib6_node *pn = NULL; 591 struct rt6key *key; 592 int bit; 593 __be32 dir = 0; 594 595 RT6_TRACE("fib6_add_1\n"); 596 597 /* insert node in tree */ 598 599 fn = root; 600 601 do { 602 key = (struct rt6key *)((u8 *)fn->leaf + offset); 603 604 /* 605 * Prefix match 606 */ 607 if (plen < fn->fn_bit || 608 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 609 if (!allow_create) { 610 if (replace_required) { 611 NL_SET_ERR_MSG(extack, 612 "Can not replace route - no match found"); 613 pr_warn("Can't replace route, no match found\n"); 614 return ERR_PTR(-ENOENT); 615 } 616 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 617 } 618 goto insert_above; 619 } 620 621 /* 622 * Exact match ? 623 */ 624 625 if (plen == fn->fn_bit) { 626 /* clean up an intermediate node */ 627 if (!(fn->fn_flags & RTN_RTINFO)) { 628 rt6_release(fn->leaf); 629 fn->leaf = NULL; 630 } 631 632 fn->fn_sernum = sernum; 633 634 return fn; 635 } 636 637 /* 638 * We have more bits to go 639 */ 640 641 /* Try to walk down on tree. */ 642 fn->fn_sernum = sernum; 643 dir = addr_bit_set(addr, fn->fn_bit); 644 pn = fn; 645 fn = dir ? fn->right : fn->left; 646 } while (fn); 647 648 if (!allow_create) { 649 /* We should not create new node because 650 * NLM_F_REPLACE was specified without NLM_F_CREATE 651 * I assume it is safe to require NLM_F_CREATE when 652 * REPLACE flag is used! Later we may want to remove the 653 * check for replace_required, because according 654 * to netlink specification, NLM_F_CREATE 655 * MUST be specified if new route is created. 656 * That would keep IPv6 consistent with IPv4 657 */ 658 if (replace_required) { 659 NL_SET_ERR_MSG(extack, 660 "Can not replace route - no match found"); 661 pr_warn("Can't replace route, no match found\n"); 662 return ERR_PTR(-ENOENT); 663 } 664 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 665 } 666 /* 667 * We walked to the bottom of tree. 668 * Create new leaf node without children. 669 */ 670 671 ln = node_alloc(); 672 673 if (!ln) 674 return ERR_PTR(-ENOMEM); 675 ln->fn_bit = plen; 676 677 ln->parent = pn; 678 ln->fn_sernum = sernum; 679 680 if (dir) 681 pn->right = ln; 682 else 683 pn->left = ln; 684 685 return ln; 686 687 688 insert_above: 689 /* 690 * split since we don't have a common prefix anymore or 691 * we have a less significant route. 692 * we've to insert an intermediate node on the list 693 * this new node will point to the one we need to create 694 * and the current 695 */ 696 697 pn = fn->parent; 698 699 /* find 1st bit in difference between the 2 addrs. 700 701 See comment in __ipv6_addr_diff: bit may be an invalid value, 702 but if it is >= plen, the value is ignored in any case. 703 */ 704 705 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 706 707 /* 708 * (intermediate)[in] 709 * / \ 710 * (new leaf node)[ln] (old node)[fn] 711 */ 712 if (plen > bit) { 713 in = node_alloc(); 714 ln = node_alloc(); 715 716 if (!in || !ln) { 717 if (in) 718 node_free_immediate(in); 719 if (ln) 720 node_free_immediate(ln); 721 return ERR_PTR(-ENOMEM); 722 } 723 724 /* 725 * new intermediate node. 726 * RTN_RTINFO will 727 * be off since that an address that chooses one of 728 * the branches would not match less specific routes 729 * in the other branch 730 */ 731 732 in->fn_bit = bit; 733 734 in->parent = pn; 735 in->leaf = fn->leaf; 736 atomic_inc(&in->leaf->rt6i_ref); 737 738 in->fn_sernum = sernum; 739 740 /* update parent pointer */ 741 if (dir) 742 pn->right = in; 743 else 744 pn->left = in; 745 746 ln->fn_bit = plen; 747 748 ln->parent = in; 749 fn->parent = in; 750 751 ln->fn_sernum = sernum; 752 753 if (addr_bit_set(addr, bit)) { 754 in->right = ln; 755 in->left = fn; 756 } else { 757 in->left = ln; 758 in->right = fn; 759 } 760 } else { /* plen <= bit */ 761 762 /* 763 * (new leaf node)[ln] 764 * / \ 765 * (old node)[fn] NULL 766 */ 767 768 ln = node_alloc(); 769 770 if (!ln) 771 return ERR_PTR(-ENOMEM); 772 773 ln->fn_bit = plen; 774 775 ln->parent = pn; 776 777 ln->fn_sernum = sernum; 778 779 if (dir) 780 pn->right = ln; 781 else 782 pn->left = ln; 783 784 if (addr_bit_set(&key->addr, plen)) 785 ln->right = fn; 786 else 787 ln->left = fn; 788 789 fn->parent = ln; 790 } 791 return ln; 792 } 793 794 static bool rt6_qualify_for_ecmp(struct rt6_info *rt) 795 { 796 return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) == 797 RTF_GATEWAY; 798 } 799 800 static void fib6_copy_metrics(u32 *mp, const struct mx6_config *mxc) 801 { 802 int i; 803 804 for (i = 0; i < RTAX_MAX; i++) { 805 if (test_bit(i, mxc->mx_valid)) 806 mp[i] = mxc->mx[i]; 807 } 808 } 809 810 static int fib6_commit_metrics(struct dst_entry *dst, struct mx6_config *mxc) 811 { 812 if (!mxc->mx) 813 return 0; 814 815 if (dst->flags & DST_HOST) { 816 u32 *mp = dst_metrics_write_ptr(dst); 817 818 if (unlikely(!mp)) 819 return -ENOMEM; 820 821 fib6_copy_metrics(mp, mxc); 822 } else { 823 dst_init_metrics(dst, mxc->mx, false); 824 825 /* We've stolen mx now. */ 826 mxc->mx = NULL; 827 } 828 829 return 0; 830 } 831 832 static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn, 833 struct net *net) 834 { 835 if (atomic_read(&rt->rt6i_ref) != 1) { 836 /* This route is used as dummy address holder in some split 837 * nodes. It is not leaked, but it still holds other resources, 838 * which must be released in time. So, scan ascendant nodes 839 * and replace dummy references to this route with references 840 * to still alive ones. 841 */ 842 while (fn) { 843 if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) { 844 fn->leaf = fib6_find_prefix(net, fn); 845 atomic_inc(&fn->leaf->rt6i_ref); 846 rt6_release(rt); 847 } 848 fn = fn->parent; 849 } 850 } 851 } 852 853 /* 854 * Insert routing information in a node. 855 */ 856 857 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, 858 struct nl_info *info, struct mx6_config *mxc) 859 { 860 struct rt6_info *iter = NULL; 861 struct rt6_info **ins; 862 struct rt6_info **fallback_ins = NULL; 863 int replace = (info->nlh && 864 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 865 int add = (!info->nlh || 866 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 867 int found = 0; 868 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 869 u16 nlflags = NLM_F_EXCL; 870 int err; 871 872 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND)) 873 nlflags |= NLM_F_APPEND; 874 875 ins = &fn->leaf; 876 877 for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) { 878 /* 879 * Search for duplicates 880 */ 881 882 if (iter->rt6i_metric == rt->rt6i_metric) { 883 /* 884 * Same priority level 885 */ 886 if (info->nlh && 887 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 888 return -EEXIST; 889 890 nlflags &= ~NLM_F_EXCL; 891 if (replace) { 892 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) { 893 found++; 894 break; 895 } 896 if (rt_can_ecmp) 897 fallback_ins = fallback_ins ?: ins; 898 goto next_iter; 899 } 900 901 if (rt6_duplicate_nexthop(iter, rt)) { 902 if (rt->rt6i_nsiblings) 903 rt->rt6i_nsiblings = 0; 904 if (!(iter->rt6i_flags & RTF_EXPIRES)) 905 return -EEXIST; 906 if (!(rt->rt6i_flags & RTF_EXPIRES)) 907 rt6_clean_expires(iter); 908 else 909 rt6_set_expires(iter, rt->dst.expires); 910 iter->rt6i_pmtu = rt->rt6i_pmtu; 911 return -EEXIST; 912 } 913 /* If we have the same destination and the same metric, 914 * but not the same gateway, then the route we try to 915 * add is sibling to this route, increment our counter 916 * of siblings, and later we will add our route to the 917 * list. 918 * Only static routes (which don't have flag 919 * RTF_EXPIRES) are used for ECMPv6. 920 * 921 * To avoid long list, we only had siblings if the 922 * route have a gateway. 923 */ 924 if (rt_can_ecmp && 925 rt6_qualify_for_ecmp(iter)) 926 rt->rt6i_nsiblings++; 927 } 928 929 if (iter->rt6i_metric > rt->rt6i_metric) 930 break; 931 932 next_iter: 933 ins = &iter->dst.rt6_next; 934 } 935 936 if (fallback_ins && !found) { 937 /* No ECMP-able route found, replace first non-ECMP one */ 938 ins = fallback_ins; 939 iter = *ins; 940 found++; 941 } 942 943 /* Reset round-robin state, if necessary */ 944 if (ins == &fn->leaf) 945 fn->rr_ptr = NULL; 946 947 /* Link this route to others same route. */ 948 if (rt->rt6i_nsiblings) { 949 unsigned int rt6i_nsiblings; 950 struct rt6_info *sibling, *temp_sibling; 951 952 /* Find the first route that have the same metric */ 953 sibling = fn->leaf; 954 while (sibling) { 955 if (sibling->rt6i_metric == rt->rt6i_metric && 956 rt6_qualify_for_ecmp(sibling)) { 957 list_add_tail(&rt->rt6i_siblings, 958 &sibling->rt6i_siblings); 959 break; 960 } 961 sibling = sibling->dst.rt6_next; 962 } 963 /* For each sibling in the list, increment the counter of 964 * siblings. BUG() if counters does not match, list of siblings 965 * is broken! 966 */ 967 rt6i_nsiblings = 0; 968 list_for_each_entry_safe(sibling, temp_sibling, 969 &rt->rt6i_siblings, rt6i_siblings) { 970 sibling->rt6i_nsiblings++; 971 BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings); 972 rt6i_nsiblings++; 973 } 974 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings); 975 } 976 977 /* 978 * insert node 979 */ 980 if (!replace) { 981 if (!add) 982 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 983 984 add: 985 nlflags |= NLM_F_CREATE; 986 err = fib6_commit_metrics(&rt->dst, mxc); 987 if (err) 988 return err; 989 990 rt->dst.rt6_next = iter; 991 *ins = rt; 992 rcu_assign_pointer(rt->rt6i_node, fn); 993 atomic_inc(&rt->rt6i_ref); 994 call_fib6_entry_notifiers(info->nl_net, FIB_EVENT_ENTRY_ADD, 995 rt); 996 if (!info->skip_notify) 997 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); 998 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 999 1000 if (!(fn->fn_flags & RTN_RTINFO)) { 1001 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1002 fn->fn_flags |= RTN_RTINFO; 1003 } 1004 1005 } else { 1006 int nsiblings; 1007 1008 if (!found) { 1009 if (add) 1010 goto add; 1011 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 1012 return -ENOENT; 1013 } 1014 1015 err = fib6_commit_metrics(&rt->dst, mxc); 1016 if (err) 1017 return err; 1018 1019 *ins = rt; 1020 rcu_assign_pointer(rt->rt6i_node, fn); 1021 rt->dst.rt6_next = iter->dst.rt6_next; 1022 atomic_inc(&rt->rt6i_ref); 1023 call_fib6_entry_notifiers(info->nl_net, FIB_EVENT_ENTRY_REPLACE, 1024 rt); 1025 if (!info->skip_notify) 1026 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); 1027 if (!(fn->fn_flags & RTN_RTINFO)) { 1028 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1029 fn->fn_flags |= RTN_RTINFO; 1030 } 1031 nsiblings = iter->rt6i_nsiblings; 1032 iter->rt6i_node = NULL; 1033 fib6_purge_rt(iter, fn, info->nl_net); 1034 if (fn->rr_ptr == iter) 1035 fn->rr_ptr = NULL; 1036 rt6_release(iter); 1037 1038 if (nsiblings) { 1039 /* Replacing an ECMP route, remove all siblings */ 1040 ins = &rt->dst.rt6_next; 1041 iter = *ins; 1042 while (iter) { 1043 if (iter->rt6i_metric > rt->rt6i_metric) 1044 break; 1045 if (rt6_qualify_for_ecmp(iter)) { 1046 *ins = iter->dst.rt6_next; 1047 iter->rt6i_node = NULL; 1048 fib6_purge_rt(iter, fn, info->nl_net); 1049 if (fn->rr_ptr == iter) 1050 fn->rr_ptr = NULL; 1051 rt6_release(iter); 1052 nsiblings--; 1053 } else { 1054 ins = &iter->dst.rt6_next; 1055 } 1056 iter = *ins; 1057 } 1058 WARN_ON(nsiblings != 0); 1059 } 1060 } 1061 1062 return 0; 1063 } 1064 1065 static void fib6_start_gc(struct net *net, struct rt6_info *rt) 1066 { 1067 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 1068 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE))) 1069 mod_timer(&net->ipv6.ip6_fib_timer, 1070 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1071 } 1072 1073 void fib6_force_start_gc(struct net *net) 1074 { 1075 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 1076 mod_timer(&net->ipv6.ip6_fib_timer, 1077 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1078 } 1079 1080 /* 1081 * Add routing information to the routing tree. 1082 * <destination addr>/<source addr> 1083 * with source addr info in sub-trees 1084 */ 1085 1086 int fib6_add(struct fib6_node *root, struct rt6_info *rt, 1087 struct nl_info *info, struct mx6_config *mxc, 1088 struct netlink_ext_ack *extack) 1089 { 1090 struct fib6_node *fn, *pn = NULL; 1091 int err = -ENOMEM; 1092 int allow_create = 1; 1093 int replace_required = 0; 1094 int sernum = fib6_new_sernum(info->nl_net); 1095 1096 if (WARN_ON_ONCE(!atomic_read(&rt->dst.__refcnt))) 1097 return -EINVAL; 1098 1099 if (info->nlh) { 1100 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 1101 allow_create = 0; 1102 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 1103 replace_required = 1; 1104 } 1105 if (!allow_create && !replace_required) 1106 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 1107 1108 fn = fib6_add_1(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 1109 offsetof(struct rt6_info, rt6i_dst), allow_create, 1110 replace_required, sernum, extack); 1111 if (IS_ERR(fn)) { 1112 err = PTR_ERR(fn); 1113 fn = NULL; 1114 goto out; 1115 } 1116 1117 pn = fn; 1118 1119 #ifdef CONFIG_IPV6_SUBTREES 1120 if (rt->rt6i_src.plen) { 1121 struct fib6_node *sn; 1122 1123 if (!fn->subtree) { 1124 struct fib6_node *sfn; 1125 1126 /* 1127 * Create subtree. 1128 * 1129 * fn[main tree] 1130 * | 1131 * sfn[subtree root] 1132 * \ 1133 * sn[new leaf node] 1134 */ 1135 1136 /* Create subtree root node */ 1137 sfn = node_alloc(); 1138 if (!sfn) 1139 goto failure; 1140 1141 sfn->leaf = info->nl_net->ipv6.ip6_null_entry; 1142 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref); 1143 sfn->fn_flags = RTN_ROOT; 1144 sfn->fn_sernum = sernum; 1145 1146 /* Now add the first leaf node to new subtree */ 1147 1148 sn = fib6_add_1(sfn, &rt->rt6i_src.addr, 1149 rt->rt6i_src.plen, 1150 offsetof(struct rt6_info, rt6i_src), 1151 allow_create, replace_required, sernum, 1152 extack); 1153 1154 if (IS_ERR(sn)) { 1155 /* If it is failed, discard just allocated 1156 root, and then (in failure) stale node 1157 in main tree. 1158 */ 1159 node_free_immediate(sfn); 1160 err = PTR_ERR(sn); 1161 goto failure; 1162 } 1163 1164 /* Now link new subtree to main tree */ 1165 sfn->parent = fn; 1166 fn->subtree = sfn; 1167 } else { 1168 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr, 1169 rt->rt6i_src.plen, 1170 offsetof(struct rt6_info, rt6i_src), 1171 allow_create, replace_required, sernum, 1172 extack); 1173 1174 if (IS_ERR(sn)) { 1175 err = PTR_ERR(sn); 1176 goto failure; 1177 } 1178 } 1179 1180 if (!fn->leaf) { 1181 fn->leaf = rt; 1182 atomic_inc(&rt->rt6i_ref); 1183 } 1184 fn = sn; 1185 } 1186 #endif 1187 1188 err = fib6_add_rt2node(fn, rt, info, mxc); 1189 if (!err) { 1190 fib6_start_gc(info->nl_net, rt); 1191 if (!(rt->rt6i_flags & RTF_CACHE)) 1192 fib6_prune_clones(info->nl_net, pn); 1193 } 1194 1195 out: 1196 if (err) { 1197 #ifdef CONFIG_IPV6_SUBTREES 1198 /* 1199 * If fib6_add_1 has cleared the old leaf pointer in the 1200 * super-tree leaf node we have to find a new one for it. 1201 */ 1202 if (pn != fn && pn->leaf == rt) { 1203 pn->leaf = NULL; 1204 atomic_dec(&rt->rt6i_ref); 1205 } 1206 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) { 1207 pn->leaf = fib6_find_prefix(info->nl_net, pn); 1208 #if RT6_DEBUG >= 2 1209 if (!pn->leaf) { 1210 WARN_ON(pn->leaf == NULL); 1211 pn->leaf = info->nl_net->ipv6.ip6_null_entry; 1212 } 1213 #endif 1214 atomic_inc(&pn->leaf->rt6i_ref); 1215 } 1216 #endif 1217 goto failure; 1218 } 1219 return err; 1220 1221 failure: 1222 /* fn->leaf could be NULL if fn is an intermediate node and we 1223 * failed to add the new route to it in both subtree creation 1224 * failure and fib6_add_rt2node() failure case. 1225 * In both cases, fib6_repair_tree() should be called to fix 1226 * fn->leaf. 1227 */ 1228 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT))) 1229 fib6_repair_tree(info->nl_net, fn); 1230 /* Always release dst as dst->__refcnt is guaranteed 1231 * to be taken before entering this function 1232 */ 1233 dst_release_immediate(&rt->dst); 1234 return err; 1235 } 1236 1237 /* 1238 * Routing tree lookup 1239 * 1240 */ 1241 1242 struct lookup_args { 1243 int offset; /* key offset on rt6_info */ 1244 const struct in6_addr *addr; /* search key */ 1245 }; 1246 1247 static struct fib6_node *fib6_lookup_1(struct fib6_node *root, 1248 struct lookup_args *args) 1249 { 1250 struct fib6_node *fn; 1251 __be32 dir; 1252 1253 if (unlikely(args->offset == 0)) 1254 return NULL; 1255 1256 /* 1257 * Descend on a tree 1258 */ 1259 1260 fn = root; 1261 1262 for (;;) { 1263 struct fib6_node *next; 1264 1265 dir = addr_bit_set(args->addr, fn->fn_bit); 1266 1267 next = dir ? fn->right : fn->left; 1268 1269 if (next) { 1270 fn = next; 1271 continue; 1272 } 1273 break; 1274 } 1275 1276 while (fn) { 1277 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) { 1278 struct rt6key *key; 1279 1280 key = (struct rt6key *) ((u8 *) fn->leaf + 1281 args->offset); 1282 1283 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1284 #ifdef CONFIG_IPV6_SUBTREES 1285 if (fn->subtree) { 1286 struct fib6_node *sfn; 1287 sfn = fib6_lookup_1(fn->subtree, 1288 args + 1); 1289 if (!sfn) 1290 goto backtrack; 1291 fn = sfn; 1292 } 1293 #endif 1294 if (fn->fn_flags & RTN_RTINFO) 1295 return fn; 1296 } 1297 } 1298 #ifdef CONFIG_IPV6_SUBTREES 1299 backtrack: 1300 #endif 1301 if (fn->fn_flags & RTN_ROOT) 1302 break; 1303 1304 fn = fn->parent; 1305 } 1306 1307 return NULL; 1308 } 1309 1310 struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr, 1311 const struct in6_addr *saddr) 1312 { 1313 struct fib6_node *fn; 1314 struct lookup_args args[] = { 1315 { 1316 .offset = offsetof(struct rt6_info, rt6i_dst), 1317 .addr = daddr, 1318 }, 1319 #ifdef CONFIG_IPV6_SUBTREES 1320 { 1321 .offset = offsetof(struct rt6_info, rt6i_src), 1322 .addr = saddr, 1323 }, 1324 #endif 1325 { 1326 .offset = 0, /* sentinel */ 1327 } 1328 }; 1329 1330 fn = fib6_lookup_1(root, daddr ? args : args + 1); 1331 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1332 fn = root; 1333 1334 return fn; 1335 } 1336 1337 /* 1338 * Get node with specified destination prefix (and source prefix, 1339 * if subtrees are used) 1340 */ 1341 1342 1343 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1344 const struct in6_addr *addr, 1345 int plen, int offset) 1346 { 1347 struct fib6_node *fn; 1348 1349 for (fn = root; fn ; ) { 1350 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset); 1351 1352 /* 1353 * Prefix match 1354 */ 1355 if (plen < fn->fn_bit || 1356 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1357 return NULL; 1358 1359 if (plen == fn->fn_bit) 1360 return fn; 1361 1362 /* 1363 * We have more bits to go 1364 */ 1365 if (addr_bit_set(addr, fn->fn_bit)) 1366 fn = fn->right; 1367 else 1368 fn = fn->left; 1369 } 1370 return NULL; 1371 } 1372 1373 struct fib6_node *fib6_locate(struct fib6_node *root, 1374 const struct in6_addr *daddr, int dst_len, 1375 const struct in6_addr *saddr, int src_len) 1376 { 1377 struct fib6_node *fn; 1378 1379 fn = fib6_locate_1(root, daddr, dst_len, 1380 offsetof(struct rt6_info, rt6i_dst)); 1381 1382 #ifdef CONFIG_IPV6_SUBTREES 1383 if (src_len) { 1384 WARN_ON(saddr == NULL); 1385 if (fn && fn->subtree) 1386 fn = fib6_locate_1(fn->subtree, saddr, src_len, 1387 offsetof(struct rt6_info, rt6i_src)); 1388 } 1389 #endif 1390 1391 if (fn && fn->fn_flags & RTN_RTINFO) 1392 return fn; 1393 1394 return NULL; 1395 } 1396 1397 1398 /* 1399 * Deletion 1400 * 1401 */ 1402 1403 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn) 1404 { 1405 if (fn->fn_flags & RTN_ROOT) 1406 return net->ipv6.ip6_null_entry; 1407 1408 while (fn) { 1409 if (fn->left) 1410 return fn->left->leaf; 1411 if (fn->right) 1412 return fn->right->leaf; 1413 1414 fn = FIB6_SUBTREE(fn); 1415 } 1416 return NULL; 1417 } 1418 1419 /* 1420 * Called to trim the tree of intermediate nodes when possible. "fn" 1421 * is the node we want to try and remove. 1422 */ 1423 1424 static struct fib6_node *fib6_repair_tree(struct net *net, 1425 struct fib6_node *fn) 1426 { 1427 int children; 1428 int nstate; 1429 struct fib6_node *child, *pn; 1430 struct fib6_walker *w; 1431 int iter = 0; 1432 1433 for (;;) { 1434 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1435 iter++; 1436 1437 WARN_ON(fn->fn_flags & RTN_RTINFO); 1438 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1439 WARN_ON(fn->leaf); 1440 1441 children = 0; 1442 child = NULL; 1443 if (fn->right) 1444 child = fn->right, children |= 1; 1445 if (fn->left) 1446 child = fn->left, children |= 2; 1447 1448 if (children == 3 || FIB6_SUBTREE(fn) 1449 #ifdef CONFIG_IPV6_SUBTREES 1450 /* Subtree root (i.e. fn) may have one child */ 1451 || (children && fn->fn_flags & RTN_ROOT) 1452 #endif 1453 ) { 1454 fn->leaf = fib6_find_prefix(net, fn); 1455 #if RT6_DEBUG >= 2 1456 if (!fn->leaf) { 1457 WARN_ON(!fn->leaf); 1458 fn->leaf = net->ipv6.ip6_null_entry; 1459 } 1460 #endif 1461 atomic_inc(&fn->leaf->rt6i_ref); 1462 return fn->parent; 1463 } 1464 1465 pn = fn->parent; 1466 #ifdef CONFIG_IPV6_SUBTREES 1467 if (FIB6_SUBTREE(pn) == fn) { 1468 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1469 FIB6_SUBTREE(pn) = NULL; 1470 nstate = FWS_L; 1471 } else { 1472 WARN_ON(fn->fn_flags & RTN_ROOT); 1473 #endif 1474 if (pn->right == fn) 1475 pn->right = child; 1476 else if (pn->left == fn) 1477 pn->left = child; 1478 #if RT6_DEBUG >= 2 1479 else 1480 WARN_ON(1); 1481 #endif 1482 if (child) 1483 child->parent = pn; 1484 nstate = FWS_R; 1485 #ifdef CONFIG_IPV6_SUBTREES 1486 } 1487 #endif 1488 1489 read_lock(&net->ipv6.fib6_walker_lock); 1490 FOR_WALKERS(net, w) { 1491 if (!child) { 1492 if (w->root == fn) { 1493 w->root = w->node = NULL; 1494 RT6_TRACE("W %p adjusted by delroot 1\n", w); 1495 } else if (w->node == fn) { 1496 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1497 w->node = pn; 1498 w->state = nstate; 1499 } 1500 } else { 1501 if (w->root == fn) { 1502 w->root = child; 1503 RT6_TRACE("W %p adjusted by delroot 2\n", w); 1504 } 1505 if (w->node == fn) { 1506 w->node = child; 1507 if (children&2) { 1508 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1509 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1510 } else { 1511 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1512 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1513 } 1514 } 1515 } 1516 } 1517 read_unlock(&net->ipv6.fib6_walker_lock); 1518 1519 node_free(fn); 1520 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1521 return pn; 1522 1523 rt6_release(pn->leaf); 1524 pn->leaf = NULL; 1525 fn = pn; 1526 } 1527 } 1528 1529 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp, 1530 struct nl_info *info) 1531 { 1532 struct fib6_walker *w; 1533 struct rt6_info *rt = *rtp; 1534 struct net *net = info->nl_net; 1535 1536 RT6_TRACE("fib6_del_route\n"); 1537 1538 /* Unlink it */ 1539 *rtp = rt->dst.rt6_next; 1540 rt->rt6i_node = NULL; 1541 net->ipv6.rt6_stats->fib_rt_entries--; 1542 net->ipv6.rt6_stats->fib_discarded_routes++; 1543 1544 /* Reset round-robin state, if necessary */ 1545 if (fn->rr_ptr == rt) 1546 fn->rr_ptr = NULL; 1547 1548 /* Remove this entry from other siblings */ 1549 if (rt->rt6i_nsiblings) { 1550 struct rt6_info *sibling, *next_sibling; 1551 1552 list_for_each_entry_safe(sibling, next_sibling, 1553 &rt->rt6i_siblings, rt6i_siblings) 1554 sibling->rt6i_nsiblings--; 1555 rt->rt6i_nsiblings = 0; 1556 list_del_init(&rt->rt6i_siblings); 1557 } 1558 1559 /* Adjust walkers */ 1560 read_lock(&net->ipv6.fib6_walker_lock); 1561 FOR_WALKERS(net, w) { 1562 if (w->state == FWS_C && w->leaf == rt) { 1563 RT6_TRACE("walker %p adjusted by delroute\n", w); 1564 w->leaf = rt->dst.rt6_next; 1565 if (!w->leaf) 1566 w->state = FWS_U; 1567 } 1568 } 1569 read_unlock(&net->ipv6.fib6_walker_lock); 1570 1571 rt->dst.rt6_next = NULL; 1572 1573 /* If it was last route, expunge its radix tree node */ 1574 if (!fn->leaf) { 1575 fn->fn_flags &= ~RTN_RTINFO; 1576 net->ipv6.rt6_stats->fib_route_nodes--; 1577 fn = fib6_repair_tree(net, fn); 1578 } 1579 1580 fib6_purge_rt(rt, fn, net); 1581 1582 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt); 1583 if (!info->skip_notify) 1584 inet6_rt_notify(RTM_DELROUTE, rt, info, 0); 1585 rt6_release(rt); 1586 } 1587 1588 int fib6_del(struct rt6_info *rt, struct nl_info *info) 1589 { 1590 struct fib6_node *fn = rcu_dereference_protected(rt->rt6i_node, 1591 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 1592 struct net *net = info->nl_net; 1593 struct rt6_info **rtp; 1594 1595 #if RT6_DEBUG >= 2 1596 if (rt->dst.obsolete > 0) { 1597 WARN_ON(fn); 1598 return -ENOENT; 1599 } 1600 #endif 1601 if (!fn || rt == net->ipv6.ip6_null_entry) 1602 return -ENOENT; 1603 1604 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1605 1606 if (!(rt->rt6i_flags & RTF_CACHE)) { 1607 struct fib6_node *pn = fn; 1608 #ifdef CONFIG_IPV6_SUBTREES 1609 /* clones of this route might be in another subtree */ 1610 if (rt->rt6i_src.plen) { 1611 while (!(pn->fn_flags & RTN_ROOT)) 1612 pn = pn->parent; 1613 pn = pn->parent; 1614 } 1615 #endif 1616 fib6_prune_clones(info->nl_net, pn); 1617 } 1618 1619 /* 1620 * Walk the leaf entries looking for ourself 1621 */ 1622 1623 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) { 1624 if (*rtp == rt) { 1625 fib6_del_route(fn, rtp, info); 1626 return 0; 1627 } 1628 } 1629 return -ENOENT; 1630 } 1631 1632 /* 1633 * Tree traversal function. 1634 * 1635 * Certainly, it is not interrupt safe. 1636 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1637 * It means, that we can modify tree during walking 1638 * and use this function for garbage collection, clone pruning, 1639 * cleaning tree when a device goes down etc. etc. 1640 * 1641 * It guarantees that every node will be traversed, 1642 * and that it will be traversed only once. 1643 * 1644 * Callback function w->func may return: 1645 * 0 -> continue walking. 1646 * positive value -> walking is suspended (used by tree dumps, 1647 * and probably by gc, if it will be split to several slices) 1648 * negative value -> terminate walking. 1649 * 1650 * The function itself returns: 1651 * 0 -> walk is complete. 1652 * >0 -> walk is incomplete (i.e. suspended) 1653 * <0 -> walk is terminated by an error. 1654 */ 1655 1656 static int fib6_walk_continue(struct fib6_walker *w) 1657 { 1658 struct fib6_node *fn, *pn; 1659 1660 for (;;) { 1661 fn = w->node; 1662 if (!fn) 1663 return 0; 1664 1665 if (w->prune && fn != w->root && 1666 fn->fn_flags & RTN_RTINFO && w->state < FWS_C) { 1667 w->state = FWS_C; 1668 w->leaf = fn->leaf; 1669 } 1670 switch (w->state) { 1671 #ifdef CONFIG_IPV6_SUBTREES 1672 case FWS_S: 1673 if (FIB6_SUBTREE(fn)) { 1674 w->node = FIB6_SUBTREE(fn); 1675 continue; 1676 } 1677 w->state = FWS_L; 1678 #endif 1679 case FWS_L: 1680 if (fn->left) { 1681 w->node = fn->left; 1682 w->state = FWS_INIT; 1683 continue; 1684 } 1685 w->state = FWS_R; 1686 case FWS_R: 1687 if (fn->right) { 1688 w->node = fn->right; 1689 w->state = FWS_INIT; 1690 continue; 1691 } 1692 w->state = FWS_C; 1693 w->leaf = fn->leaf; 1694 case FWS_C: 1695 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1696 int err; 1697 1698 if (w->skip) { 1699 w->skip--; 1700 goto skip; 1701 } 1702 1703 err = w->func(w); 1704 if (err) 1705 return err; 1706 1707 w->count++; 1708 continue; 1709 } 1710 skip: 1711 w->state = FWS_U; 1712 case FWS_U: 1713 if (fn == w->root) 1714 return 0; 1715 pn = fn->parent; 1716 w->node = pn; 1717 #ifdef CONFIG_IPV6_SUBTREES 1718 if (FIB6_SUBTREE(pn) == fn) { 1719 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1720 w->state = FWS_L; 1721 continue; 1722 } 1723 #endif 1724 if (pn->left == fn) { 1725 w->state = FWS_R; 1726 continue; 1727 } 1728 if (pn->right == fn) { 1729 w->state = FWS_C; 1730 w->leaf = w->node->leaf; 1731 continue; 1732 } 1733 #if RT6_DEBUG >= 2 1734 WARN_ON(1); 1735 #endif 1736 } 1737 } 1738 } 1739 1740 static int fib6_walk(struct net *net, struct fib6_walker *w) 1741 { 1742 int res; 1743 1744 w->state = FWS_INIT; 1745 w->node = w->root; 1746 1747 fib6_walker_link(net, w); 1748 res = fib6_walk_continue(w); 1749 if (res <= 0) 1750 fib6_walker_unlink(net, w); 1751 return res; 1752 } 1753 1754 static int fib6_clean_node(struct fib6_walker *w) 1755 { 1756 int res; 1757 struct rt6_info *rt; 1758 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 1759 struct nl_info info = { 1760 .nl_net = c->net, 1761 }; 1762 1763 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 1764 w->node->fn_sernum != c->sernum) 1765 w->node->fn_sernum = c->sernum; 1766 1767 if (!c->func) { 1768 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 1769 w->leaf = NULL; 1770 return 0; 1771 } 1772 1773 for (rt = w->leaf; rt; rt = rt->dst.rt6_next) { 1774 res = c->func(rt, c->arg); 1775 if (res < 0) { 1776 w->leaf = rt; 1777 res = fib6_del(rt, &info); 1778 if (res) { 1779 #if RT6_DEBUG >= 2 1780 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 1781 __func__, rt, 1782 rcu_access_pointer(rt->rt6i_node), 1783 res); 1784 #endif 1785 continue; 1786 } 1787 return 0; 1788 } 1789 WARN_ON(res != 0); 1790 } 1791 w->leaf = rt; 1792 return 0; 1793 } 1794 1795 /* 1796 * Convenient frontend to tree walker. 1797 * 1798 * func is called on each route. 1799 * It may return -1 -> delete this route. 1800 * 0 -> continue walking 1801 * 1802 * prune==1 -> only immediate children of node (certainly, 1803 * ignoring pure split nodes) will be scanned. 1804 */ 1805 1806 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 1807 int (*func)(struct rt6_info *, void *arg), 1808 bool prune, int sernum, void *arg) 1809 { 1810 struct fib6_cleaner c; 1811 1812 c.w.root = root; 1813 c.w.func = fib6_clean_node; 1814 c.w.prune = prune; 1815 c.w.count = 0; 1816 c.w.skip = 0; 1817 c.func = func; 1818 c.sernum = sernum; 1819 c.arg = arg; 1820 c.net = net; 1821 1822 fib6_walk(net, &c.w); 1823 } 1824 1825 static void __fib6_clean_all(struct net *net, 1826 int (*func)(struct rt6_info *, void *), 1827 int sernum, void *arg) 1828 { 1829 struct fib6_table *table; 1830 struct hlist_head *head; 1831 unsigned int h; 1832 1833 rcu_read_lock(); 1834 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 1835 head = &net->ipv6.fib_table_hash[h]; 1836 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 1837 write_lock_bh(&table->tb6_lock); 1838 fib6_clean_tree(net, &table->tb6_root, 1839 func, false, sernum, arg); 1840 write_unlock_bh(&table->tb6_lock); 1841 } 1842 } 1843 rcu_read_unlock(); 1844 } 1845 1846 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *), 1847 void *arg) 1848 { 1849 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg); 1850 } 1851 1852 static int fib6_prune_clone(struct rt6_info *rt, void *arg) 1853 { 1854 if (rt->rt6i_flags & RTF_CACHE) { 1855 RT6_TRACE("pruning clone %p\n", rt); 1856 return -1; 1857 } 1858 1859 return 0; 1860 } 1861 1862 static void fib6_prune_clones(struct net *net, struct fib6_node *fn) 1863 { 1864 fib6_clean_tree(net, fn, fib6_prune_clone, true, 1865 FIB6_NO_SERNUM_CHANGE, NULL); 1866 } 1867 1868 static void fib6_flush_trees(struct net *net) 1869 { 1870 int new_sernum = fib6_new_sernum(net); 1871 1872 __fib6_clean_all(net, NULL, new_sernum, NULL); 1873 } 1874 1875 /* 1876 * Garbage collection 1877 */ 1878 1879 struct fib6_gc_args 1880 { 1881 int timeout; 1882 int more; 1883 }; 1884 1885 static int fib6_age(struct rt6_info *rt, void *arg) 1886 { 1887 struct fib6_gc_args *gc_args = arg; 1888 unsigned long now = jiffies; 1889 1890 /* 1891 * check addrconf expiration here. 1892 * Routes are expired even if they are in use. 1893 * 1894 * Also age clones. Note, that clones are aged out 1895 * only if they are not in use now. 1896 */ 1897 1898 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) { 1899 if (time_after(now, rt->dst.expires)) { 1900 RT6_TRACE("expiring %p\n", rt); 1901 return -1; 1902 } 1903 gc_args->more++; 1904 } else if (rt->rt6i_flags & RTF_CACHE) { 1905 if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) 1906 rt->dst.obsolete = DST_OBSOLETE_KILL; 1907 if (atomic_read(&rt->dst.__refcnt) == 1 && 1908 rt->dst.obsolete == DST_OBSOLETE_KILL) { 1909 RT6_TRACE("aging clone %p\n", rt); 1910 return -1; 1911 } else if (rt->rt6i_flags & RTF_GATEWAY) { 1912 struct neighbour *neigh; 1913 __u8 neigh_flags = 0; 1914 1915 neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway); 1916 if (neigh) { 1917 neigh_flags = neigh->flags; 1918 neigh_release(neigh); 1919 } 1920 if (!(neigh_flags & NTF_ROUTER)) { 1921 RT6_TRACE("purging route %p via non-router but gateway\n", 1922 rt); 1923 return -1; 1924 } 1925 } 1926 gc_args->more++; 1927 } 1928 1929 return 0; 1930 } 1931 1932 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 1933 { 1934 struct fib6_gc_args gc_args; 1935 unsigned long now; 1936 1937 if (force) { 1938 spin_lock_bh(&net->ipv6.fib6_gc_lock); 1939 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) { 1940 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 1941 return; 1942 } 1943 gc_args.timeout = expires ? (int)expires : 1944 net->ipv6.sysctl.ip6_rt_gc_interval; 1945 gc_args.more = 0; 1946 1947 fib6_clean_all(net, fib6_age, &gc_args); 1948 now = jiffies; 1949 net->ipv6.ip6_rt_last_gc = now; 1950 1951 if (gc_args.more) 1952 mod_timer(&net->ipv6.ip6_fib_timer, 1953 round_jiffies(now 1954 + net->ipv6.sysctl.ip6_rt_gc_interval)); 1955 else 1956 del_timer(&net->ipv6.ip6_fib_timer); 1957 spin_unlock_bh(&net->ipv6.fib6_gc_lock); 1958 } 1959 1960 static void fib6_gc_timer_cb(unsigned long arg) 1961 { 1962 fib6_run_gc(0, (struct net *)arg, true); 1963 } 1964 1965 static int __net_init fib6_net_init(struct net *net) 1966 { 1967 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 1968 int err; 1969 1970 err = fib6_notifier_init(net); 1971 if (err) 1972 return err; 1973 1974 spin_lock_init(&net->ipv6.fib6_gc_lock); 1975 rwlock_init(&net->ipv6.fib6_walker_lock); 1976 INIT_LIST_HEAD(&net->ipv6.fib6_walkers); 1977 setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net); 1978 1979 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 1980 if (!net->ipv6.rt6_stats) 1981 goto out_timer; 1982 1983 /* Avoid false sharing : Use at least a full cache line */ 1984 size = max_t(size_t, size, L1_CACHE_BYTES); 1985 1986 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 1987 if (!net->ipv6.fib_table_hash) 1988 goto out_rt6_stats; 1989 1990 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 1991 GFP_KERNEL); 1992 if (!net->ipv6.fib6_main_tbl) 1993 goto out_fib_table_hash; 1994 1995 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 1996 net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 1997 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 1998 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 1999 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 2000 2001 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2002 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 2003 GFP_KERNEL); 2004 if (!net->ipv6.fib6_local_tbl) 2005 goto out_fib6_main_tbl; 2006 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 2007 net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry; 2008 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 2009 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2010 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 2011 #endif 2012 fib6_tables_init(net); 2013 2014 return 0; 2015 2016 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2017 out_fib6_main_tbl: 2018 kfree(net->ipv6.fib6_main_tbl); 2019 #endif 2020 out_fib_table_hash: 2021 kfree(net->ipv6.fib_table_hash); 2022 out_rt6_stats: 2023 kfree(net->ipv6.rt6_stats); 2024 out_timer: 2025 fib6_notifier_exit(net); 2026 return -ENOMEM; 2027 } 2028 2029 static void fib6_net_exit(struct net *net) 2030 { 2031 unsigned int i; 2032 2033 rt6_ifdown(net, NULL); 2034 del_timer_sync(&net->ipv6.ip6_fib_timer); 2035 2036 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) { 2037 struct hlist_head *head = &net->ipv6.fib_table_hash[i]; 2038 struct hlist_node *tmp; 2039 struct fib6_table *tb; 2040 2041 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) { 2042 hlist_del(&tb->tb6_hlist); 2043 fib6_free_table(tb); 2044 } 2045 } 2046 2047 kfree(net->ipv6.fib_table_hash); 2048 kfree(net->ipv6.rt6_stats); 2049 fib6_notifier_exit(net); 2050 } 2051 2052 static struct pernet_operations fib6_net_ops = { 2053 .init = fib6_net_init, 2054 .exit = fib6_net_exit, 2055 }; 2056 2057 int __init fib6_init(void) 2058 { 2059 int ret = -ENOMEM; 2060 2061 fib6_node_kmem = kmem_cache_create("fib6_nodes", 2062 sizeof(struct fib6_node), 2063 0, SLAB_HWCACHE_ALIGN, 2064 NULL); 2065 if (!fib6_node_kmem) 2066 goto out; 2067 2068 ret = register_pernet_subsys(&fib6_net_ops); 2069 if (ret) 2070 goto out_kmem_cache_create; 2071 2072 ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib, 2073 0); 2074 if (ret) 2075 goto out_unregister_subsys; 2076 2077 __fib6_flush_trees = fib6_flush_trees; 2078 out: 2079 return ret; 2080 2081 out_unregister_subsys: 2082 unregister_pernet_subsys(&fib6_net_ops); 2083 out_kmem_cache_create: 2084 kmem_cache_destroy(fib6_node_kmem); 2085 goto out; 2086 } 2087 2088 void fib6_gc_cleanup(void) 2089 { 2090 unregister_pernet_subsys(&fib6_net_ops); 2091 kmem_cache_destroy(fib6_node_kmem); 2092 } 2093 2094 #ifdef CONFIG_PROC_FS 2095 2096 struct ipv6_route_iter { 2097 struct seq_net_private p; 2098 struct fib6_walker w; 2099 loff_t skip; 2100 struct fib6_table *tbl; 2101 int sernum; 2102 }; 2103 2104 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 2105 { 2106 struct rt6_info *rt = v; 2107 struct ipv6_route_iter *iter = seq->private; 2108 2109 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen); 2110 2111 #ifdef CONFIG_IPV6_SUBTREES 2112 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen); 2113 #else 2114 seq_puts(seq, "00000000000000000000000000000000 00 "); 2115 #endif 2116 if (rt->rt6i_flags & RTF_GATEWAY) 2117 seq_printf(seq, "%pi6", &rt->rt6i_gateway); 2118 else 2119 seq_puts(seq, "00000000000000000000000000000000"); 2120 2121 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 2122 rt->rt6i_metric, atomic_read(&rt->dst.__refcnt), 2123 rt->dst.__use, rt->rt6i_flags, 2124 rt->dst.dev ? rt->dst.dev->name : ""); 2125 iter->w.leaf = NULL; 2126 return 0; 2127 } 2128 2129 static int ipv6_route_yield(struct fib6_walker *w) 2130 { 2131 struct ipv6_route_iter *iter = w->args; 2132 2133 if (!iter->skip) 2134 return 1; 2135 2136 do { 2137 iter->w.leaf = iter->w.leaf->dst.rt6_next; 2138 iter->skip--; 2139 if (!iter->skip && iter->w.leaf) 2140 return 1; 2141 } while (iter->w.leaf); 2142 2143 return 0; 2144 } 2145 2146 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter, 2147 struct net *net) 2148 { 2149 memset(&iter->w, 0, sizeof(iter->w)); 2150 iter->w.func = ipv6_route_yield; 2151 iter->w.root = &iter->tbl->tb6_root; 2152 iter->w.state = FWS_INIT; 2153 iter->w.node = iter->w.root; 2154 iter->w.args = iter; 2155 iter->sernum = iter->w.root->fn_sernum; 2156 INIT_LIST_HEAD(&iter->w.lh); 2157 fib6_walker_link(net, &iter->w); 2158 } 2159 2160 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 2161 struct net *net) 2162 { 2163 unsigned int h; 2164 struct hlist_node *node; 2165 2166 if (tbl) { 2167 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 2168 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 2169 } else { 2170 h = 0; 2171 node = NULL; 2172 } 2173 2174 while (!node && h < FIB6_TABLE_HASHSZ) { 2175 node = rcu_dereference_bh( 2176 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 2177 } 2178 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 2179 } 2180 2181 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 2182 { 2183 if (iter->sernum != iter->w.root->fn_sernum) { 2184 iter->sernum = iter->w.root->fn_sernum; 2185 iter->w.state = FWS_INIT; 2186 iter->w.node = iter->w.root; 2187 WARN_ON(iter->w.skip); 2188 iter->w.skip = iter->w.count; 2189 } 2190 } 2191 2192 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2193 { 2194 int r; 2195 struct rt6_info *n; 2196 struct net *net = seq_file_net(seq); 2197 struct ipv6_route_iter *iter = seq->private; 2198 2199 if (!v) 2200 goto iter_table; 2201 2202 n = ((struct rt6_info *)v)->dst.rt6_next; 2203 if (n) { 2204 ++*pos; 2205 return n; 2206 } 2207 2208 iter_table: 2209 ipv6_route_check_sernum(iter); 2210 read_lock(&iter->tbl->tb6_lock); 2211 r = fib6_walk_continue(&iter->w); 2212 read_unlock(&iter->tbl->tb6_lock); 2213 if (r > 0) { 2214 if (v) 2215 ++*pos; 2216 return iter->w.leaf; 2217 } else if (r < 0) { 2218 fib6_walker_unlink(net, &iter->w); 2219 return NULL; 2220 } 2221 fib6_walker_unlink(net, &iter->w); 2222 2223 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 2224 if (!iter->tbl) 2225 return NULL; 2226 2227 ipv6_route_seq_setup_walk(iter, net); 2228 goto iter_table; 2229 } 2230 2231 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 2232 __acquires(RCU_BH) 2233 { 2234 struct net *net = seq_file_net(seq); 2235 struct ipv6_route_iter *iter = seq->private; 2236 2237 rcu_read_lock_bh(); 2238 iter->tbl = ipv6_route_seq_next_table(NULL, net); 2239 iter->skip = *pos; 2240 2241 if (iter->tbl) { 2242 ipv6_route_seq_setup_walk(iter, net); 2243 return ipv6_route_seq_next(seq, NULL, pos); 2244 } else { 2245 return NULL; 2246 } 2247 } 2248 2249 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 2250 { 2251 struct fib6_walker *w = &iter->w; 2252 return w->node && !(w->state == FWS_U && w->node == w->root); 2253 } 2254 2255 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2256 __releases(RCU_BH) 2257 { 2258 struct net *net = seq_file_net(seq); 2259 struct ipv6_route_iter *iter = seq->private; 2260 2261 if (ipv6_route_iter_active(iter)) 2262 fib6_walker_unlink(net, &iter->w); 2263 2264 rcu_read_unlock_bh(); 2265 } 2266 2267 static const struct seq_operations ipv6_route_seq_ops = { 2268 .start = ipv6_route_seq_start, 2269 .next = ipv6_route_seq_next, 2270 .stop = ipv6_route_seq_stop, 2271 .show = ipv6_route_seq_show 2272 }; 2273 2274 int ipv6_route_open(struct inode *inode, struct file *file) 2275 { 2276 return seq_open_net(inode, file, &ipv6_route_seq_ops, 2277 sizeof(struct ipv6_route_iter)); 2278 } 2279 2280 #endif /* CONFIG_PROC_FS */ 2281