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 fib6_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 fib6_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 net *net, struct fib6_info *rt) 109 { 110 struct fib6_node *fn; 111 112 fn = rcu_dereference_protected(rt->rt6i_node, 113 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 114 if (fn) 115 fn->fn_sernum = fib6_new_sernum(net); 116 } 117 118 /* 119 * Auxiliary address test functions for the radix tree. 120 * 121 * These assume a 32bit processor (although it will work on 122 * 64bit processors) 123 */ 124 125 /* 126 * test bit 127 */ 128 #if defined(__LITTLE_ENDIAN) 129 # define BITOP_BE32_SWIZZLE (0x1F & ~7) 130 #else 131 # define BITOP_BE32_SWIZZLE 0 132 #endif 133 134 static __be32 addr_bit_set(const void *token, int fn_bit) 135 { 136 const __be32 *addr = token; 137 /* 138 * Here, 139 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f) 140 * is optimized version of 141 * htonl(1 << ((~fn_bit)&0x1F)) 142 * See include/asm-generic/bitops/le.h. 143 */ 144 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) & 145 addr[fn_bit >> 5]; 146 } 147 148 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags) 149 { 150 struct fib6_info *f6i; 151 152 f6i = kzalloc(sizeof(*f6i), gfp_flags); 153 if (!f6i) 154 return NULL; 155 156 f6i->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags); 157 if (!f6i->rt6i_pcpu) { 158 kfree(f6i); 159 return NULL; 160 } 161 162 INIT_LIST_HEAD(&f6i->rt6i_siblings); 163 f6i->fib6_metrics = (struct dst_metrics *)&dst_default_metrics; 164 165 atomic_inc(&f6i->rt6i_ref); 166 167 return f6i; 168 } 169 170 void fib6_info_destroy(struct fib6_info *f6i) 171 { 172 struct rt6_exception_bucket *bucket; 173 struct dst_metrics *m; 174 175 WARN_ON(f6i->rt6i_node); 176 177 bucket = rcu_dereference_protected(f6i->rt6i_exception_bucket, 1); 178 if (bucket) { 179 f6i->rt6i_exception_bucket = NULL; 180 kfree(bucket); 181 } 182 183 if (f6i->rt6i_pcpu) { 184 int cpu; 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(f6i->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 } 199 200 if (f6i->rt6i_idev) 201 in6_dev_put(f6i->rt6i_idev); 202 if (f6i->fib6_nh.nh_dev) 203 dev_put(f6i->fib6_nh.nh_dev); 204 205 m = f6i->fib6_metrics; 206 if (m != &dst_default_metrics && refcount_dec_and_test(&m->refcnt)) 207 kfree(m); 208 209 kfree(f6i); 210 } 211 EXPORT_SYMBOL_GPL(fib6_info_destroy); 212 213 static struct fib6_node *node_alloc(struct net *net) 214 { 215 struct fib6_node *fn; 216 217 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); 218 if (fn) 219 net->ipv6.rt6_stats->fib_nodes++; 220 221 return fn; 222 } 223 224 static void node_free_immediate(struct net *net, struct fib6_node *fn) 225 { 226 kmem_cache_free(fib6_node_kmem, fn); 227 net->ipv6.rt6_stats->fib_nodes--; 228 } 229 230 static void node_free_rcu(struct rcu_head *head) 231 { 232 struct fib6_node *fn = container_of(head, struct fib6_node, rcu); 233 234 kmem_cache_free(fib6_node_kmem, fn); 235 } 236 237 static void node_free(struct net *net, struct fib6_node *fn) 238 { 239 call_rcu(&fn->rcu, node_free_rcu); 240 net->ipv6.rt6_stats->fib_nodes--; 241 } 242 243 static void fib6_free_table(struct fib6_table *table) 244 { 245 inetpeer_invalidate_tree(&table->tb6_peers); 246 kfree(table); 247 } 248 249 static void fib6_link_table(struct net *net, struct fib6_table *tb) 250 { 251 unsigned int h; 252 253 /* 254 * Initialize table lock at a single place to give lockdep a key, 255 * tables aren't visible prior to being linked to the list. 256 */ 257 spin_lock_init(&tb->tb6_lock); 258 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 259 260 /* 261 * No protection necessary, this is the only list mutatation 262 * operation, tables never disappear once they exist. 263 */ 264 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 265 } 266 267 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 268 269 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 270 { 271 struct fib6_table *table; 272 273 table = kzalloc(sizeof(*table), GFP_ATOMIC); 274 if (table) { 275 table->tb6_id = id; 276 rcu_assign_pointer(table->tb6_root.leaf, 277 net->ipv6.fib6_null_entry); 278 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 279 inet_peer_base_init(&table->tb6_peers); 280 } 281 282 return table; 283 } 284 285 struct fib6_table *fib6_new_table(struct net *net, u32 id) 286 { 287 struct fib6_table *tb; 288 289 if (id == 0) 290 id = RT6_TABLE_MAIN; 291 tb = fib6_get_table(net, id); 292 if (tb) 293 return tb; 294 295 tb = fib6_alloc_table(net, id); 296 if (tb) 297 fib6_link_table(net, tb); 298 299 return tb; 300 } 301 EXPORT_SYMBOL_GPL(fib6_new_table); 302 303 struct fib6_table *fib6_get_table(struct net *net, u32 id) 304 { 305 struct fib6_table *tb; 306 struct hlist_head *head; 307 unsigned int h; 308 309 if (id == 0) 310 id = RT6_TABLE_MAIN; 311 h = id & (FIB6_TABLE_HASHSZ - 1); 312 rcu_read_lock(); 313 head = &net->ipv6.fib_table_hash[h]; 314 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 315 if (tb->tb6_id == id) { 316 rcu_read_unlock(); 317 return tb; 318 } 319 } 320 rcu_read_unlock(); 321 322 return NULL; 323 } 324 EXPORT_SYMBOL_GPL(fib6_get_table); 325 326 static void __net_init fib6_tables_init(struct net *net) 327 { 328 fib6_link_table(net, net->ipv6.fib6_main_tbl); 329 fib6_link_table(net, net->ipv6.fib6_local_tbl); 330 } 331 #else 332 333 struct fib6_table *fib6_new_table(struct net *net, u32 id) 334 { 335 return fib6_get_table(net, id); 336 } 337 338 struct fib6_table *fib6_get_table(struct net *net, u32 id) 339 { 340 return net->ipv6.fib6_main_tbl; 341 } 342 343 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 344 const struct sk_buff *skb, 345 int flags, pol_lookup_t lookup) 346 { 347 struct rt6_info *rt; 348 349 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags); 350 if (rt->dst.error == -EAGAIN) { 351 ip6_rt_put(rt); 352 rt = net->ipv6.ip6_null_entry; 353 dst_hold(&rt->dst); 354 } 355 356 return &rt->dst; 357 } 358 359 static void __net_init fib6_tables_init(struct net *net) 360 { 361 fib6_link_table(net, net->ipv6.fib6_main_tbl); 362 } 363 364 #endif 365 366 unsigned int fib6_tables_seq_read(struct net *net) 367 { 368 unsigned int h, fib_seq = 0; 369 370 rcu_read_lock(); 371 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 372 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 373 struct fib6_table *tb; 374 375 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 376 fib_seq += tb->fib_seq; 377 } 378 rcu_read_unlock(); 379 380 return fib_seq; 381 } 382 383 static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net, 384 enum fib_event_type event_type, 385 struct fib6_info *rt) 386 { 387 struct fib6_entry_notifier_info info = { 388 .rt = rt, 389 }; 390 391 return call_fib6_notifier(nb, net, event_type, &info.info); 392 } 393 394 static int call_fib6_entry_notifiers(struct net *net, 395 enum fib_event_type event_type, 396 struct fib6_info *rt, 397 struct netlink_ext_ack *extack) 398 { 399 struct fib6_entry_notifier_info info = { 400 .info.extack = extack, 401 .rt = rt, 402 }; 403 404 rt->rt6i_table->fib_seq++; 405 return call_fib6_notifiers(net, event_type, &info.info); 406 } 407 408 struct fib6_dump_arg { 409 struct net *net; 410 struct notifier_block *nb; 411 }; 412 413 static void fib6_rt_dump(struct fib6_info *rt, struct fib6_dump_arg *arg) 414 { 415 if (rt == arg->net->ipv6.fib6_null_entry) 416 return; 417 call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt); 418 } 419 420 static int fib6_node_dump(struct fib6_walker *w) 421 { 422 struct fib6_info *rt; 423 424 for_each_fib6_walker_rt(w) 425 fib6_rt_dump(rt, w->args); 426 w->leaf = NULL; 427 return 0; 428 } 429 430 static void fib6_table_dump(struct net *net, struct fib6_table *tb, 431 struct fib6_walker *w) 432 { 433 w->root = &tb->tb6_root; 434 spin_lock_bh(&tb->tb6_lock); 435 fib6_walk(net, w); 436 spin_unlock_bh(&tb->tb6_lock); 437 } 438 439 /* Called with rcu_read_lock() */ 440 int fib6_tables_dump(struct net *net, struct notifier_block *nb) 441 { 442 struct fib6_dump_arg arg; 443 struct fib6_walker *w; 444 unsigned int h; 445 446 w = kzalloc(sizeof(*w), GFP_ATOMIC); 447 if (!w) 448 return -ENOMEM; 449 450 w->func = fib6_node_dump; 451 arg.net = net; 452 arg.nb = nb; 453 w->args = &arg; 454 455 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 456 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 457 struct fib6_table *tb; 458 459 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 460 fib6_table_dump(net, tb, w); 461 } 462 463 kfree(w); 464 465 return 0; 466 } 467 468 static int fib6_dump_node(struct fib6_walker *w) 469 { 470 int res; 471 struct fib6_info *rt; 472 473 for_each_fib6_walker_rt(w) { 474 res = rt6_dump_route(rt, w->args); 475 if (res < 0) { 476 /* Frame is full, suspend walking */ 477 w->leaf = rt; 478 return 1; 479 } 480 481 /* Multipath routes are dumped in one route with the 482 * RTA_MULTIPATH attribute. Jump 'rt' to point to the 483 * last sibling of this route (no need to dump the 484 * sibling routes again) 485 */ 486 if (rt->rt6i_nsiblings) 487 rt = list_last_entry(&rt->rt6i_siblings, 488 struct fib6_info, 489 rt6i_siblings); 490 } 491 w->leaf = NULL; 492 return 0; 493 } 494 495 static void fib6_dump_end(struct netlink_callback *cb) 496 { 497 struct net *net = sock_net(cb->skb->sk); 498 struct fib6_walker *w = (void *)cb->args[2]; 499 500 if (w) { 501 if (cb->args[4]) { 502 cb->args[4] = 0; 503 fib6_walker_unlink(net, w); 504 } 505 cb->args[2] = 0; 506 kfree(w); 507 } 508 cb->done = (void *)cb->args[3]; 509 cb->args[1] = 3; 510 } 511 512 static int fib6_dump_done(struct netlink_callback *cb) 513 { 514 fib6_dump_end(cb); 515 return cb->done ? cb->done(cb) : 0; 516 } 517 518 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 519 struct netlink_callback *cb) 520 { 521 struct net *net = sock_net(skb->sk); 522 struct fib6_walker *w; 523 int res; 524 525 w = (void *)cb->args[2]; 526 w->root = &table->tb6_root; 527 528 if (cb->args[4] == 0) { 529 w->count = 0; 530 w->skip = 0; 531 532 spin_lock_bh(&table->tb6_lock); 533 res = fib6_walk(net, w); 534 spin_unlock_bh(&table->tb6_lock); 535 if (res > 0) { 536 cb->args[4] = 1; 537 cb->args[5] = w->root->fn_sernum; 538 } 539 } else { 540 if (cb->args[5] != w->root->fn_sernum) { 541 /* Begin at the root if the tree changed */ 542 cb->args[5] = w->root->fn_sernum; 543 w->state = FWS_INIT; 544 w->node = w->root; 545 w->skip = w->count; 546 } else 547 w->skip = 0; 548 549 spin_lock_bh(&table->tb6_lock); 550 res = fib6_walk_continue(w); 551 spin_unlock_bh(&table->tb6_lock); 552 if (res <= 0) { 553 fib6_walker_unlink(net, w); 554 cb->args[4] = 0; 555 } 556 } 557 558 return res; 559 } 560 561 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 562 { 563 struct net *net = sock_net(skb->sk); 564 unsigned int h, s_h; 565 unsigned int e = 0, s_e; 566 struct rt6_rtnl_dump_arg arg; 567 struct fib6_walker *w; 568 struct fib6_table *tb; 569 struct hlist_head *head; 570 int res = 0; 571 572 s_h = cb->args[0]; 573 s_e = cb->args[1]; 574 575 w = (void *)cb->args[2]; 576 if (!w) { 577 /* New dump: 578 * 579 * 1. hook callback destructor. 580 */ 581 cb->args[3] = (long)cb->done; 582 cb->done = fib6_dump_done; 583 584 /* 585 * 2. allocate and initialize walker. 586 */ 587 w = kzalloc(sizeof(*w), GFP_ATOMIC); 588 if (!w) 589 return -ENOMEM; 590 w->func = fib6_dump_node; 591 cb->args[2] = (long)w; 592 } 593 594 arg.skb = skb; 595 arg.cb = cb; 596 arg.net = net; 597 w->args = &arg; 598 599 rcu_read_lock(); 600 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 601 e = 0; 602 head = &net->ipv6.fib_table_hash[h]; 603 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 604 if (e < s_e) 605 goto next; 606 res = fib6_dump_table(tb, skb, cb); 607 if (res != 0) 608 goto out; 609 next: 610 e++; 611 } 612 } 613 out: 614 rcu_read_unlock(); 615 cb->args[1] = e; 616 cb->args[0] = h; 617 618 res = res < 0 ? res : skb->len; 619 if (res <= 0) 620 fib6_dump_end(cb); 621 return res; 622 } 623 624 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val) 625 { 626 if (!f6i) 627 return; 628 629 if (f6i->fib6_metrics == &dst_default_metrics) { 630 struct dst_metrics *p = kzalloc(sizeof(*p), GFP_ATOMIC); 631 632 if (!p) 633 return; 634 635 refcount_set(&p->refcnt, 1); 636 f6i->fib6_metrics = p; 637 } 638 639 f6i->fib6_metrics->metrics[metric - 1] = val; 640 } 641 642 /* 643 * Routing Table 644 * 645 * return the appropriate node for a routing tree "add" operation 646 * by either creating and inserting or by returning an existing 647 * node. 648 */ 649 650 static struct fib6_node *fib6_add_1(struct net *net, 651 struct fib6_table *table, 652 struct fib6_node *root, 653 struct in6_addr *addr, int plen, 654 int offset, int allow_create, 655 int replace_required, 656 struct netlink_ext_ack *extack) 657 { 658 struct fib6_node *fn, *in, *ln; 659 struct fib6_node *pn = NULL; 660 struct rt6key *key; 661 int bit; 662 __be32 dir = 0; 663 664 RT6_TRACE("fib6_add_1\n"); 665 666 /* insert node in tree */ 667 668 fn = root; 669 670 do { 671 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 672 lockdep_is_held(&table->tb6_lock)); 673 key = (struct rt6key *)((u8 *)leaf + offset); 674 675 /* 676 * Prefix match 677 */ 678 if (plen < fn->fn_bit || 679 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 680 if (!allow_create) { 681 if (replace_required) { 682 NL_SET_ERR_MSG(extack, 683 "Can not replace route - no match found"); 684 pr_warn("Can't replace route, no match found\n"); 685 return ERR_PTR(-ENOENT); 686 } 687 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 688 } 689 goto insert_above; 690 } 691 692 /* 693 * Exact match ? 694 */ 695 696 if (plen == fn->fn_bit) { 697 /* clean up an intermediate node */ 698 if (!(fn->fn_flags & RTN_RTINFO)) { 699 RCU_INIT_POINTER(fn->leaf, NULL); 700 fib6_info_release(leaf); 701 /* remove null_entry in the root node */ 702 } else if (fn->fn_flags & RTN_TL_ROOT && 703 rcu_access_pointer(fn->leaf) == 704 net->ipv6.fib6_null_entry) { 705 RCU_INIT_POINTER(fn->leaf, NULL); 706 } 707 708 return fn; 709 } 710 711 /* 712 * We have more bits to go 713 */ 714 715 /* Try to walk down on tree. */ 716 dir = addr_bit_set(addr, fn->fn_bit); 717 pn = fn; 718 fn = dir ? 719 rcu_dereference_protected(fn->right, 720 lockdep_is_held(&table->tb6_lock)) : 721 rcu_dereference_protected(fn->left, 722 lockdep_is_held(&table->tb6_lock)); 723 } while (fn); 724 725 if (!allow_create) { 726 /* We should not create new node because 727 * NLM_F_REPLACE was specified without NLM_F_CREATE 728 * I assume it is safe to require NLM_F_CREATE when 729 * REPLACE flag is used! Later we may want to remove the 730 * check for replace_required, because according 731 * to netlink specification, NLM_F_CREATE 732 * MUST be specified if new route is created. 733 * That would keep IPv6 consistent with IPv4 734 */ 735 if (replace_required) { 736 NL_SET_ERR_MSG(extack, 737 "Can not replace route - no match found"); 738 pr_warn("Can't replace route, no match found\n"); 739 return ERR_PTR(-ENOENT); 740 } 741 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 742 } 743 /* 744 * We walked to the bottom of tree. 745 * Create new leaf node without children. 746 */ 747 748 ln = node_alloc(net); 749 750 if (!ln) 751 return ERR_PTR(-ENOMEM); 752 ln->fn_bit = plen; 753 RCU_INIT_POINTER(ln->parent, pn); 754 755 if (dir) 756 rcu_assign_pointer(pn->right, ln); 757 else 758 rcu_assign_pointer(pn->left, ln); 759 760 return ln; 761 762 763 insert_above: 764 /* 765 * split since we don't have a common prefix anymore or 766 * we have a less significant route. 767 * we've to insert an intermediate node on the list 768 * this new node will point to the one we need to create 769 * and the current 770 */ 771 772 pn = rcu_dereference_protected(fn->parent, 773 lockdep_is_held(&table->tb6_lock)); 774 775 /* find 1st bit in difference between the 2 addrs. 776 777 See comment in __ipv6_addr_diff: bit may be an invalid value, 778 but if it is >= plen, the value is ignored in any case. 779 */ 780 781 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 782 783 /* 784 * (intermediate)[in] 785 * / \ 786 * (new leaf node)[ln] (old node)[fn] 787 */ 788 if (plen > bit) { 789 in = node_alloc(net); 790 ln = node_alloc(net); 791 792 if (!in || !ln) { 793 if (in) 794 node_free_immediate(net, in); 795 if (ln) 796 node_free_immediate(net, ln); 797 return ERR_PTR(-ENOMEM); 798 } 799 800 /* 801 * new intermediate node. 802 * RTN_RTINFO will 803 * be off since that an address that chooses one of 804 * the branches would not match less specific routes 805 * in the other branch 806 */ 807 808 in->fn_bit = bit; 809 810 RCU_INIT_POINTER(in->parent, pn); 811 in->leaf = fn->leaf; 812 atomic_inc(&rcu_dereference_protected(in->leaf, 813 lockdep_is_held(&table->tb6_lock))->rt6i_ref); 814 815 /* update parent pointer */ 816 if (dir) 817 rcu_assign_pointer(pn->right, in); 818 else 819 rcu_assign_pointer(pn->left, in); 820 821 ln->fn_bit = plen; 822 823 RCU_INIT_POINTER(ln->parent, in); 824 rcu_assign_pointer(fn->parent, in); 825 826 if (addr_bit_set(addr, bit)) { 827 rcu_assign_pointer(in->right, ln); 828 rcu_assign_pointer(in->left, fn); 829 } else { 830 rcu_assign_pointer(in->left, ln); 831 rcu_assign_pointer(in->right, fn); 832 } 833 } else { /* plen <= bit */ 834 835 /* 836 * (new leaf node)[ln] 837 * / \ 838 * (old node)[fn] NULL 839 */ 840 841 ln = node_alloc(net); 842 843 if (!ln) 844 return ERR_PTR(-ENOMEM); 845 846 ln->fn_bit = plen; 847 848 RCU_INIT_POINTER(ln->parent, pn); 849 850 if (addr_bit_set(&key->addr, plen)) 851 RCU_INIT_POINTER(ln->right, fn); 852 else 853 RCU_INIT_POINTER(ln->left, fn); 854 855 rcu_assign_pointer(fn->parent, ln); 856 857 if (dir) 858 rcu_assign_pointer(pn->right, ln); 859 else 860 rcu_assign_pointer(pn->left, ln); 861 } 862 return ln; 863 } 864 865 static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn, 866 struct net *net) 867 { 868 struct fib6_table *table = rt->rt6i_table; 869 870 if (atomic_read(&rt->rt6i_ref) != 1) { 871 /* This route is used as dummy address holder in some split 872 * nodes. It is not leaked, but it still holds other resources, 873 * which must be released in time. So, scan ascendant nodes 874 * and replace dummy references to this route with references 875 * to still alive ones. 876 */ 877 while (fn) { 878 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 879 lockdep_is_held(&table->tb6_lock)); 880 struct fib6_info *new_leaf; 881 if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) { 882 new_leaf = fib6_find_prefix(net, table, fn); 883 atomic_inc(&new_leaf->rt6i_ref); 884 885 rcu_assign_pointer(fn->leaf, new_leaf); 886 fib6_info_release(rt); 887 } 888 fn = rcu_dereference_protected(fn->parent, 889 lockdep_is_held(&table->tb6_lock)); 890 } 891 892 if (rt->rt6i_pcpu) { 893 int cpu; 894 895 /* release the reference to this fib entry from 896 * all of its cached pcpu routes 897 */ 898 for_each_possible_cpu(cpu) { 899 struct rt6_info **ppcpu_rt; 900 struct rt6_info *pcpu_rt; 901 902 ppcpu_rt = per_cpu_ptr(rt->rt6i_pcpu, cpu); 903 pcpu_rt = *ppcpu_rt; 904 if (pcpu_rt) { 905 fib6_info_release(pcpu_rt->from); 906 pcpu_rt->from = NULL; 907 } 908 } 909 } 910 } 911 } 912 913 /* 914 * Insert routing information in a node. 915 */ 916 917 static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt, 918 struct nl_info *info, 919 struct netlink_ext_ack *extack) 920 { 921 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 922 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 923 struct fib6_info *iter = NULL; 924 struct fib6_info __rcu **ins; 925 struct fib6_info __rcu **fallback_ins = NULL; 926 int replace = (info->nlh && 927 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 928 int add = (!info->nlh || 929 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 930 int found = 0; 931 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 932 u16 nlflags = NLM_F_EXCL; 933 int err; 934 935 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND)) 936 nlflags |= NLM_F_APPEND; 937 938 ins = &fn->leaf; 939 940 for (iter = leaf; iter; 941 iter = rcu_dereference_protected(iter->rt6_next, 942 lockdep_is_held(&rt->rt6i_table->tb6_lock))) { 943 /* 944 * Search for duplicates 945 */ 946 947 if (iter->rt6i_metric == rt->rt6i_metric) { 948 /* 949 * Same priority level 950 */ 951 if (info->nlh && 952 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 953 return -EEXIST; 954 955 nlflags &= ~NLM_F_EXCL; 956 if (replace) { 957 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) { 958 found++; 959 break; 960 } 961 if (rt_can_ecmp) 962 fallback_ins = fallback_ins ?: ins; 963 goto next_iter; 964 } 965 966 if (rt6_duplicate_nexthop(iter, rt)) { 967 if (rt->rt6i_nsiblings) 968 rt->rt6i_nsiblings = 0; 969 if (!(iter->rt6i_flags & RTF_EXPIRES)) 970 return -EEXIST; 971 if (!(rt->rt6i_flags & RTF_EXPIRES)) 972 fib6_clean_expires(iter); 973 else 974 fib6_set_expires(iter, rt->expires); 975 fib6_metric_set(iter, RTAX_MTU, rt->fib6_pmtu); 976 return -EEXIST; 977 } 978 /* If we have the same destination and the same metric, 979 * but not the same gateway, then the route we try to 980 * add is sibling to this route, increment our counter 981 * of siblings, and later we will add our route to the 982 * list. 983 * Only static routes (which don't have flag 984 * RTF_EXPIRES) are used for ECMPv6. 985 * 986 * To avoid long list, we only had siblings if the 987 * route have a gateway. 988 */ 989 if (rt_can_ecmp && 990 rt6_qualify_for_ecmp(iter)) 991 rt->rt6i_nsiblings++; 992 } 993 994 if (iter->rt6i_metric > rt->rt6i_metric) 995 break; 996 997 next_iter: 998 ins = &iter->rt6_next; 999 } 1000 1001 if (fallback_ins && !found) { 1002 /* No ECMP-able route found, replace first non-ECMP one */ 1003 ins = fallback_ins; 1004 iter = rcu_dereference_protected(*ins, 1005 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 1006 found++; 1007 } 1008 1009 /* Reset round-robin state, if necessary */ 1010 if (ins == &fn->leaf) 1011 fn->rr_ptr = NULL; 1012 1013 /* Link this route to others same route. */ 1014 if (rt->rt6i_nsiblings) { 1015 unsigned int rt6i_nsiblings; 1016 struct fib6_info *sibling, *temp_sibling; 1017 1018 /* Find the first route that have the same metric */ 1019 sibling = leaf; 1020 while (sibling) { 1021 if (sibling->rt6i_metric == rt->rt6i_metric && 1022 rt6_qualify_for_ecmp(sibling)) { 1023 list_add_tail(&rt->rt6i_siblings, 1024 &sibling->rt6i_siblings); 1025 break; 1026 } 1027 sibling = rcu_dereference_protected(sibling->rt6_next, 1028 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 1029 } 1030 /* For each sibling in the list, increment the counter of 1031 * siblings. BUG() if counters does not match, list of siblings 1032 * is broken! 1033 */ 1034 rt6i_nsiblings = 0; 1035 list_for_each_entry_safe(sibling, temp_sibling, 1036 &rt->rt6i_siblings, rt6i_siblings) { 1037 sibling->rt6i_nsiblings++; 1038 BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings); 1039 rt6i_nsiblings++; 1040 } 1041 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings); 1042 rt6_multipath_rebalance(temp_sibling); 1043 } 1044 1045 /* 1046 * insert node 1047 */ 1048 if (!replace) { 1049 if (!add) 1050 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 1051 1052 add: 1053 nlflags |= NLM_F_CREATE; 1054 1055 err = call_fib6_entry_notifiers(info->nl_net, 1056 FIB_EVENT_ENTRY_ADD, 1057 rt, extack); 1058 if (err) 1059 return err; 1060 1061 rcu_assign_pointer(rt->rt6_next, iter); 1062 atomic_inc(&rt->rt6i_ref); 1063 rcu_assign_pointer(rt->rt6i_node, fn); 1064 rcu_assign_pointer(*ins, rt); 1065 if (!info->skip_notify) 1066 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); 1067 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 1068 1069 if (!(fn->fn_flags & RTN_RTINFO)) { 1070 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1071 fn->fn_flags |= RTN_RTINFO; 1072 } 1073 1074 } else { 1075 int nsiblings; 1076 1077 if (!found) { 1078 if (add) 1079 goto add; 1080 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 1081 return -ENOENT; 1082 } 1083 1084 err = call_fib6_entry_notifiers(info->nl_net, 1085 FIB_EVENT_ENTRY_REPLACE, 1086 rt, extack); 1087 if (err) 1088 return err; 1089 1090 atomic_inc(&rt->rt6i_ref); 1091 rcu_assign_pointer(rt->rt6i_node, fn); 1092 rt->rt6_next = iter->rt6_next; 1093 rcu_assign_pointer(*ins, rt); 1094 if (!info->skip_notify) 1095 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); 1096 if (!(fn->fn_flags & RTN_RTINFO)) { 1097 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1098 fn->fn_flags |= RTN_RTINFO; 1099 } 1100 nsiblings = iter->rt6i_nsiblings; 1101 iter->rt6i_node = NULL; 1102 fib6_purge_rt(iter, fn, info->nl_net); 1103 if (rcu_access_pointer(fn->rr_ptr) == iter) 1104 fn->rr_ptr = NULL; 1105 fib6_info_release(iter); 1106 1107 if (nsiblings) { 1108 /* Replacing an ECMP route, remove all siblings */ 1109 ins = &rt->rt6_next; 1110 iter = rcu_dereference_protected(*ins, 1111 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 1112 while (iter) { 1113 if (iter->rt6i_metric > rt->rt6i_metric) 1114 break; 1115 if (rt6_qualify_for_ecmp(iter)) { 1116 *ins = iter->rt6_next; 1117 iter->rt6i_node = NULL; 1118 fib6_purge_rt(iter, fn, info->nl_net); 1119 if (rcu_access_pointer(fn->rr_ptr) == iter) 1120 fn->rr_ptr = NULL; 1121 fib6_info_release(iter); 1122 nsiblings--; 1123 info->nl_net->ipv6.rt6_stats->fib_rt_entries--; 1124 } else { 1125 ins = &iter->rt6_next; 1126 } 1127 iter = rcu_dereference_protected(*ins, 1128 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 1129 } 1130 WARN_ON(nsiblings != 0); 1131 } 1132 } 1133 1134 return 0; 1135 } 1136 1137 static void fib6_start_gc(struct net *net, struct fib6_info *rt) 1138 { 1139 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 1140 (rt->rt6i_flags & RTF_EXPIRES)) 1141 mod_timer(&net->ipv6.ip6_fib_timer, 1142 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1143 } 1144 1145 void fib6_force_start_gc(struct net *net) 1146 { 1147 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 1148 mod_timer(&net->ipv6.ip6_fib_timer, 1149 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1150 } 1151 1152 static void __fib6_update_sernum_upto_root(struct fib6_info *rt, 1153 int sernum) 1154 { 1155 struct fib6_node *fn = rcu_dereference_protected(rt->rt6i_node, 1156 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 1157 1158 /* paired with smp_rmb() in rt6_get_cookie_safe() */ 1159 smp_wmb(); 1160 while (fn) { 1161 fn->fn_sernum = sernum; 1162 fn = rcu_dereference_protected(fn->parent, 1163 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 1164 } 1165 } 1166 1167 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt) 1168 { 1169 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net)); 1170 } 1171 1172 /* 1173 * Add routing information to the routing tree. 1174 * <destination addr>/<source addr> 1175 * with source addr info in sub-trees 1176 * Need to own table->tb6_lock 1177 */ 1178 1179 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 1180 struct nl_info *info, struct netlink_ext_ack *extack) 1181 { 1182 struct fib6_table *table = rt->rt6i_table; 1183 struct fib6_node *fn, *pn = NULL; 1184 int err = -ENOMEM; 1185 int allow_create = 1; 1186 int replace_required = 0; 1187 int sernum = fib6_new_sernum(info->nl_net); 1188 1189 if (info->nlh) { 1190 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 1191 allow_create = 0; 1192 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 1193 replace_required = 1; 1194 } 1195 if (!allow_create && !replace_required) 1196 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 1197 1198 fn = fib6_add_1(info->nl_net, table, root, 1199 &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 1200 offsetof(struct fib6_info, rt6i_dst), allow_create, 1201 replace_required, extack); 1202 if (IS_ERR(fn)) { 1203 err = PTR_ERR(fn); 1204 fn = NULL; 1205 goto out; 1206 } 1207 1208 pn = fn; 1209 1210 #ifdef CONFIG_IPV6_SUBTREES 1211 if (rt->rt6i_src.plen) { 1212 struct fib6_node *sn; 1213 1214 if (!rcu_access_pointer(fn->subtree)) { 1215 struct fib6_node *sfn; 1216 1217 /* 1218 * Create subtree. 1219 * 1220 * fn[main tree] 1221 * | 1222 * sfn[subtree root] 1223 * \ 1224 * sn[new leaf node] 1225 */ 1226 1227 /* Create subtree root node */ 1228 sfn = node_alloc(info->nl_net); 1229 if (!sfn) 1230 goto failure; 1231 1232 atomic_inc(&info->nl_net->ipv6.fib6_null_entry->rt6i_ref); 1233 rcu_assign_pointer(sfn->leaf, 1234 info->nl_net->ipv6.fib6_null_entry); 1235 sfn->fn_flags = RTN_ROOT; 1236 1237 /* Now add the first leaf node to new subtree */ 1238 1239 sn = fib6_add_1(info->nl_net, table, sfn, 1240 &rt->rt6i_src.addr, rt->rt6i_src.plen, 1241 offsetof(struct fib6_info, rt6i_src), 1242 allow_create, replace_required, extack); 1243 1244 if (IS_ERR(sn)) { 1245 /* If it is failed, discard just allocated 1246 root, and then (in failure) stale node 1247 in main tree. 1248 */ 1249 node_free_immediate(info->nl_net, sfn); 1250 err = PTR_ERR(sn); 1251 goto failure; 1252 } 1253 1254 /* Now link new subtree to main tree */ 1255 rcu_assign_pointer(sfn->parent, fn); 1256 rcu_assign_pointer(fn->subtree, sfn); 1257 } else { 1258 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn), 1259 &rt->rt6i_src.addr, rt->rt6i_src.plen, 1260 offsetof(struct fib6_info, rt6i_src), 1261 allow_create, replace_required, extack); 1262 1263 if (IS_ERR(sn)) { 1264 err = PTR_ERR(sn); 1265 goto failure; 1266 } 1267 } 1268 1269 if (!rcu_access_pointer(fn->leaf)) { 1270 if (fn->fn_flags & RTN_TL_ROOT) { 1271 /* put back null_entry for root node */ 1272 rcu_assign_pointer(fn->leaf, 1273 info->nl_net->ipv6.fib6_null_entry); 1274 } else { 1275 atomic_inc(&rt->rt6i_ref); 1276 rcu_assign_pointer(fn->leaf, rt); 1277 } 1278 } 1279 fn = sn; 1280 } 1281 #endif 1282 1283 err = fib6_add_rt2node(fn, rt, info, extack); 1284 if (!err) { 1285 __fib6_update_sernum_upto_root(rt, sernum); 1286 fib6_start_gc(info->nl_net, rt); 1287 } 1288 1289 out: 1290 if (err) { 1291 #ifdef CONFIG_IPV6_SUBTREES 1292 /* 1293 * If fib6_add_1 has cleared the old leaf pointer in the 1294 * super-tree leaf node we have to find a new one for it. 1295 */ 1296 if (pn != fn) { 1297 struct fib6_info *pn_leaf = 1298 rcu_dereference_protected(pn->leaf, 1299 lockdep_is_held(&table->tb6_lock)); 1300 if (pn_leaf == rt) { 1301 pn_leaf = NULL; 1302 RCU_INIT_POINTER(pn->leaf, NULL); 1303 fib6_info_release(rt); 1304 } 1305 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) { 1306 pn_leaf = fib6_find_prefix(info->nl_net, table, 1307 pn); 1308 #if RT6_DEBUG >= 2 1309 if (!pn_leaf) { 1310 WARN_ON(!pn_leaf); 1311 pn_leaf = 1312 info->nl_net->ipv6.fib6_null_entry; 1313 } 1314 #endif 1315 fib6_info_hold(pn_leaf); 1316 rcu_assign_pointer(pn->leaf, pn_leaf); 1317 } 1318 } 1319 #endif 1320 goto failure; 1321 } 1322 return err; 1323 1324 failure: 1325 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if: 1326 * 1. fn is an intermediate node and we failed to add the new 1327 * route to it in both subtree creation failure and fib6_add_rt2node() 1328 * failure case. 1329 * 2. fn is the root node in the table and we fail to add the first 1330 * default route to it. 1331 */ 1332 if (fn && 1333 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) || 1334 (fn->fn_flags & RTN_TL_ROOT && 1335 !rcu_access_pointer(fn->leaf)))) 1336 fib6_repair_tree(info->nl_net, table, fn); 1337 return err; 1338 } 1339 1340 /* 1341 * Routing tree lookup 1342 * 1343 */ 1344 1345 struct lookup_args { 1346 int offset; /* key offset on fib6_info */ 1347 const struct in6_addr *addr; /* search key */ 1348 }; 1349 1350 static struct fib6_node *fib6_lookup_1(struct fib6_node *root, 1351 struct lookup_args *args) 1352 { 1353 struct fib6_node *fn; 1354 __be32 dir; 1355 1356 if (unlikely(args->offset == 0)) 1357 return NULL; 1358 1359 /* 1360 * Descend on a tree 1361 */ 1362 1363 fn = root; 1364 1365 for (;;) { 1366 struct fib6_node *next; 1367 1368 dir = addr_bit_set(args->addr, fn->fn_bit); 1369 1370 next = dir ? rcu_dereference(fn->right) : 1371 rcu_dereference(fn->left); 1372 1373 if (next) { 1374 fn = next; 1375 continue; 1376 } 1377 break; 1378 } 1379 1380 while (fn) { 1381 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1382 1383 if (subtree || fn->fn_flags & RTN_RTINFO) { 1384 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1385 struct rt6key *key; 1386 1387 if (!leaf) 1388 goto backtrack; 1389 1390 key = (struct rt6key *) ((u8 *)leaf + args->offset); 1391 1392 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1393 #ifdef CONFIG_IPV6_SUBTREES 1394 if (subtree) { 1395 struct fib6_node *sfn; 1396 sfn = fib6_lookup_1(subtree, args + 1); 1397 if (!sfn) 1398 goto backtrack; 1399 fn = sfn; 1400 } 1401 #endif 1402 if (fn->fn_flags & RTN_RTINFO) 1403 return fn; 1404 } 1405 } 1406 backtrack: 1407 if (fn->fn_flags & RTN_ROOT) 1408 break; 1409 1410 fn = rcu_dereference(fn->parent); 1411 } 1412 1413 return NULL; 1414 } 1415 1416 /* called with rcu_read_lock() held 1417 */ 1418 struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr, 1419 const struct in6_addr *saddr) 1420 { 1421 struct fib6_node *fn; 1422 struct lookup_args args[] = { 1423 { 1424 .offset = offsetof(struct fib6_info, rt6i_dst), 1425 .addr = daddr, 1426 }, 1427 #ifdef CONFIG_IPV6_SUBTREES 1428 { 1429 .offset = offsetof(struct fib6_info, rt6i_src), 1430 .addr = saddr, 1431 }, 1432 #endif 1433 { 1434 .offset = 0, /* sentinel */ 1435 } 1436 }; 1437 1438 fn = fib6_lookup_1(root, daddr ? args : args + 1); 1439 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1440 fn = root; 1441 1442 return fn; 1443 } 1444 1445 /* 1446 * Get node with specified destination prefix (and source prefix, 1447 * if subtrees are used) 1448 * exact_match == true means we try to find fn with exact match of 1449 * the passed in prefix addr 1450 * exact_match == false means we try to find fn with longest prefix 1451 * match of the passed in prefix addr. This is useful for finding fn 1452 * for cached route as it will be stored in the exception table under 1453 * the node with longest prefix length. 1454 */ 1455 1456 1457 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1458 const struct in6_addr *addr, 1459 int plen, int offset, 1460 bool exact_match) 1461 { 1462 struct fib6_node *fn, *prev = NULL; 1463 1464 for (fn = root; fn ; ) { 1465 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1466 struct rt6key *key; 1467 1468 /* This node is being deleted */ 1469 if (!leaf) { 1470 if (plen <= fn->fn_bit) 1471 goto out; 1472 else 1473 goto next; 1474 } 1475 1476 key = (struct rt6key *)((u8 *)leaf + offset); 1477 1478 /* 1479 * Prefix match 1480 */ 1481 if (plen < fn->fn_bit || 1482 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1483 goto out; 1484 1485 if (plen == fn->fn_bit) 1486 return fn; 1487 1488 prev = fn; 1489 1490 next: 1491 /* 1492 * We have more bits to go 1493 */ 1494 if (addr_bit_set(addr, fn->fn_bit)) 1495 fn = rcu_dereference(fn->right); 1496 else 1497 fn = rcu_dereference(fn->left); 1498 } 1499 out: 1500 if (exact_match) 1501 return NULL; 1502 else 1503 return prev; 1504 } 1505 1506 struct fib6_node *fib6_locate(struct fib6_node *root, 1507 const struct in6_addr *daddr, int dst_len, 1508 const struct in6_addr *saddr, int src_len, 1509 bool exact_match) 1510 { 1511 struct fib6_node *fn; 1512 1513 fn = fib6_locate_1(root, daddr, dst_len, 1514 offsetof(struct fib6_info, rt6i_dst), 1515 exact_match); 1516 1517 #ifdef CONFIG_IPV6_SUBTREES 1518 if (src_len) { 1519 WARN_ON(saddr == NULL); 1520 if (fn) { 1521 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1522 1523 if (subtree) { 1524 fn = fib6_locate_1(subtree, saddr, src_len, 1525 offsetof(struct fib6_info, rt6i_src), 1526 exact_match); 1527 } 1528 } 1529 } 1530 #endif 1531 1532 if (fn && fn->fn_flags & RTN_RTINFO) 1533 return fn; 1534 1535 return NULL; 1536 } 1537 1538 1539 /* 1540 * Deletion 1541 * 1542 */ 1543 1544 static struct fib6_info *fib6_find_prefix(struct net *net, 1545 struct fib6_table *table, 1546 struct fib6_node *fn) 1547 { 1548 struct fib6_node *child_left, *child_right; 1549 1550 if (fn->fn_flags & RTN_ROOT) 1551 return net->ipv6.fib6_null_entry; 1552 1553 while (fn) { 1554 child_left = rcu_dereference_protected(fn->left, 1555 lockdep_is_held(&table->tb6_lock)); 1556 child_right = rcu_dereference_protected(fn->right, 1557 lockdep_is_held(&table->tb6_lock)); 1558 if (child_left) 1559 return rcu_dereference_protected(child_left->leaf, 1560 lockdep_is_held(&table->tb6_lock)); 1561 if (child_right) 1562 return rcu_dereference_protected(child_right->leaf, 1563 lockdep_is_held(&table->tb6_lock)); 1564 1565 fn = FIB6_SUBTREE(fn); 1566 } 1567 return NULL; 1568 } 1569 1570 /* 1571 * Called to trim the tree of intermediate nodes when possible. "fn" 1572 * is the node we want to try and remove. 1573 * Need to own table->tb6_lock 1574 */ 1575 1576 static struct fib6_node *fib6_repair_tree(struct net *net, 1577 struct fib6_table *table, 1578 struct fib6_node *fn) 1579 { 1580 int children; 1581 int nstate; 1582 struct fib6_node *child; 1583 struct fib6_walker *w; 1584 int iter = 0; 1585 1586 /* Set fn->leaf to null_entry for root node. */ 1587 if (fn->fn_flags & RTN_TL_ROOT) { 1588 rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry); 1589 return fn; 1590 } 1591 1592 for (;;) { 1593 struct fib6_node *fn_r = rcu_dereference_protected(fn->right, 1594 lockdep_is_held(&table->tb6_lock)); 1595 struct fib6_node *fn_l = rcu_dereference_protected(fn->left, 1596 lockdep_is_held(&table->tb6_lock)); 1597 struct fib6_node *pn = rcu_dereference_protected(fn->parent, 1598 lockdep_is_held(&table->tb6_lock)); 1599 struct fib6_node *pn_r = rcu_dereference_protected(pn->right, 1600 lockdep_is_held(&table->tb6_lock)); 1601 struct fib6_node *pn_l = rcu_dereference_protected(pn->left, 1602 lockdep_is_held(&table->tb6_lock)); 1603 struct fib6_info *fn_leaf = rcu_dereference_protected(fn->leaf, 1604 lockdep_is_held(&table->tb6_lock)); 1605 struct fib6_info *pn_leaf = rcu_dereference_protected(pn->leaf, 1606 lockdep_is_held(&table->tb6_lock)); 1607 struct fib6_info *new_fn_leaf; 1608 1609 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1610 iter++; 1611 1612 WARN_ON(fn->fn_flags & RTN_RTINFO); 1613 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1614 WARN_ON(fn_leaf); 1615 1616 children = 0; 1617 child = NULL; 1618 if (fn_r) 1619 child = fn_r, children |= 1; 1620 if (fn_l) 1621 child = fn_l, children |= 2; 1622 1623 if (children == 3 || FIB6_SUBTREE(fn) 1624 #ifdef CONFIG_IPV6_SUBTREES 1625 /* Subtree root (i.e. fn) may have one child */ 1626 || (children && fn->fn_flags & RTN_ROOT) 1627 #endif 1628 ) { 1629 new_fn_leaf = fib6_find_prefix(net, table, fn); 1630 #if RT6_DEBUG >= 2 1631 if (!new_fn_leaf) { 1632 WARN_ON(!new_fn_leaf); 1633 new_fn_leaf = net->ipv6.fib6_null_entry; 1634 } 1635 #endif 1636 fib6_info_hold(new_fn_leaf); 1637 rcu_assign_pointer(fn->leaf, new_fn_leaf); 1638 return pn; 1639 } 1640 1641 #ifdef CONFIG_IPV6_SUBTREES 1642 if (FIB6_SUBTREE(pn) == fn) { 1643 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1644 RCU_INIT_POINTER(pn->subtree, NULL); 1645 nstate = FWS_L; 1646 } else { 1647 WARN_ON(fn->fn_flags & RTN_ROOT); 1648 #endif 1649 if (pn_r == fn) 1650 rcu_assign_pointer(pn->right, child); 1651 else if (pn_l == fn) 1652 rcu_assign_pointer(pn->left, child); 1653 #if RT6_DEBUG >= 2 1654 else 1655 WARN_ON(1); 1656 #endif 1657 if (child) 1658 rcu_assign_pointer(child->parent, pn); 1659 nstate = FWS_R; 1660 #ifdef CONFIG_IPV6_SUBTREES 1661 } 1662 #endif 1663 1664 read_lock(&net->ipv6.fib6_walker_lock); 1665 FOR_WALKERS(net, w) { 1666 if (!child) { 1667 if (w->node == fn) { 1668 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1669 w->node = pn; 1670 w->state = nstate; 1671 } 1672 } else { 1673 if (w->node == fn) { 1674 w->node = child; 1675 if (children&2) { 1676 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1677 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1678 } else { 1679 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1680 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1681 } 1682 } 1683 } 1684 } 1685 read_unlock(&net->ipv6.fib6_walker_lock); 1686 1687 node_free(net, fn); 1688 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1689 return pn; 1690 1691 RCU_INIT_POINTER(pn->leaf, NULL); 1692 fib6_info_release(pn_leaf); 1693 fn = pn; 1694 } 1695 } 1696 1697 static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn, 1698 struct fib6_info __rcu **rtp, struct nl_info *info) 1699 { 1700 struct fib6_walker *w; 1701 struct fib6_info *rt = rcu_dereference_protected(*rtp, 1702 lockdep_is_held(&table->tb6_lock)); 1703 struct net *net = info->nl_net; 1704 1705 RT6_TRACE("fib6_del_route\n"); 1706 1707 /* Unlink it */ 1708 *rtp = rt->rt6_next; 1709 rt->rt6i_node = NULL; 1710 net->ipv6.rt6_stats->fib_rt_entries--; 1711 net->ipv6.rt6_stats->fib_discarded_routes++; 1712 1713 /* Flush all cached dst in exception table */ 1714 rt6_flush_exceptions(rt); 1715 1716 /* Reset round-robin state, if necessary */ 1717 if (rcu_access_pointer(fn->rr_ptr) == rt) 1718 fn->rr_ptr = NULL; 1719 1720 /* Remove this entry from other siblings */ 1721 if (rt->rt6i_nsiblings) { 1722 struct fib6_info *sibling, *next_sibling; 1723 1724 list_for_each_entry_safe(sibling, next_sibling, 1725 &rt->rt6i_siblings, rt6i_siblings) 1726 sibling->rt6i_nsiblings--; 1727 rt->rt6i_nsiblings = 0; 1728 list_del_init(&rt->rt6i_siblings); 1729 rt6_multipath_rebalance(next_sibling); 1730 } 1731 1732 /* Adjust walkers */ 1733 read_lock(&net->ipv6.fib6_walker_lock); 1734 FOR_WALKERS(net, w) { 1735 if (w->state == FWS_C && w->leaf == rt) { 1736 RT6_TRACE("walker %p adjusted by delroute\n", w); 1737 w->leaf = rcu_dereference_protected(rt->rt6_next, 1738 lockdep_is_held(&table->tb6_lock)); 1739 if (!w->leaf) 1740 w->state = FWS_U; 1741 } 1742 } 1743 read_unlock(&net->ipv6.fib6_walker_lock); 1744 1745 /* If it was last route, call fib6_repair_tree() to: 1746 * 1. For root node, put back null_entry as how the table was created. 1747 * 2. For other nodes, expunge its radix tree node. 1748 */ 1749 if (!rcu_access_pointer(fn->leaf)) { 1750 if (!(fn->fn_flags & RTN_TL_ROOT)) { 1751 fn->fn_flags &= ~RTN_RTINFO; 1752 net->ipv6.rt6_stats->fib_route_nodes--; 1753 } 1754 fn = fib6_repair_tree(net, table, fn); 1755 } 1756 1757 fib6_purge_rt(rt, fn, net); 1758 1759 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL); 1760 if (!info->skip_notify) 1761 inet6_rt_notify(RTM_DELROUTE, rt, info, 0); 1762 fib6_info_release(rt); 1763 } 1764 1765 /* Need to own table->tb6_lock */ 1766 int fib6_del(struct fib6_info *rt, struct nl_info *info) 1767 { 1768 struct fib6_node *fn = rcu_dereference_protected(rt->rt6i_node, 1769 lockdep_is_held(&rt->rt6i_table->tb6_lock)); 1770 struct fib6_table *table = rt->rt6i_table; 1771 struct net *net = info->nl_net; 1772 struct fib6_info __rcu **rtp; 1773 struct fib6_info __rcu **rtp_next; 1774 1775 if (!fn || rt == net->ipv6.fib6_null_entry) 1776 return -ENOENT; 1777 1778 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1779 1780 /* 1781 * Walk the leaf entries looking for ourself 1782 */ 1783 1784 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) { 1785 struct fib6_info *cur = rcu_dereference_protected(*rtp, 1786 lockdep_is_held(&table->tb6_lock)); 1787 if (rt == cur) { 1788 fib6_del_route(table, fn, rtp, info); 1789 return 0; 1790 } 1791 rtp_next = &cur->rt6_next; 1792 } 1793 return -ENOENT; 1794 } 1795 1796 /* 1797 * Tree traversal function. 1798 * 1799 * Certainly, it is not interrupt safe. 1800 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1801 * It means, that we can modify tree during walking 1802 * and use this function for garbage collection, clone pruning, 1803 * cleaning tree when a device goes down etc. etc. 1804 * 1805 * It guarantees that every node will be traversed, 1806 * and that it will be traversed only once. 1807 * 1808 * Callback function w->func may return: 1809 * 0 -> continue walking. 1810 * positive value -> walking is suspended (used by tree dumps, 1811 * and probably by gc, if it will be split to several slices) 1812 * negative value -> terminate walking. 1813 * 1814 * The function itself returns: 1815 * 0 -> walk is complete. 1816 * >0 -> walk is incomplete (i.e. suspended) 1817 * <0 -> walk is terminated by an error. 1818 * 1819 * This function is called with tb6_lock held. 1820 */ 1821 1822 static int fib6_walk_continue(struct fib6_walker *w) 1823 { 1824 struct fib6_node *fn, *pn, *left, *right; 1825 1826 /* w->root should always be table->tb6_root */ 1827 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT)); 1828 1829 for (;;) { 1830 fn = w->node; 1831 if (!fn) 1832 return 0; 1833 1834 switch (w->state) { 1835 #ifdef CONFIG_IPV6_SUBTREES 1836 case FWS_S: 1837 if (FIB6_SUBTREE(fn)) { 1838 w->node = FIB6_SUBTREE(fn); 1839 continue; 1840 } 1841 w->state = FWS_L; 1842 #endif 1843 /* fall through */ 1844 case FWS_L: 1845 left = rcu_dereference_protected(fn->left, 1); 1846 if (left) { 1847 w->node = left; 1848 w->state = FWS_INIT; 1849 continue; 1850 } 1851 w->state = FWS_R; 1852 /* fall through */ 1853 case FWS_R: 1854 right = rcu_dereference_protected(fn->right, 1); 1855 if (right) { 1856 w->node = right; 1857 w->state = FWS_INIT; 1858 continue; 1859 } 1860 w->state = FWS_C; 1861 w->leaf = rcu_dereference_protected(fn->leaf, 1); 1862 /* fall through */ 1863 case FWS_C: 1864 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1865 int err; 1866 1867 if (w->skip) { 1868 w->skip--; 1869 goto skip; 1870 } 1871 1872 err = w->func(w); 1873 if (err) 1874 return err; 1875 1876 w->count++; 1877 continue; 1878 } 1879 skip: 1880 w->state = FWS_U; 1881 /* fall through */ 1882 case FWS_U: 1883 if (fn == w->root) 1884 return 0; 1885 pn = rcu_dereference_protected(fn->parent, 1); 1886 left = rcu_dereference_protected(pn->left, 1); 1887 right = rcu_dereference_protected(pn->right, 1); 1888 w->node = pn; 1889 #ifdef CONFIG_IPV6_SUBTREES 1890 if (FIB6_SUBTREE(pn) == fn) { 1891 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1892 w->state = FWS_L; 1893 continue; 1894 } 1895 #endif 1896 if (left == fn) { 1897 w->state = FWS_R; 1898 continue; 1899 } 1900 if (right == fn) { 1901 w->state = FWS_C; 1902 w->leaf = rcu_dereference_protected(w->node->leaf, 1); 1903 continue; 1904 } 1905 #if RT6_DEBUG >= 2 1906 WARN_ON(1); 1907 #endif 1908 } 1909 } 1910 } 1911 1912 static int fib6_walk(struct net *net, struct fib6_walker *w) 1913 { 1914 int res; 1915 1916 w->state = FWS_INIT; 1917 w->node = w->root; 1918 1919 fib6_walker_link(net, w); 1920 res = fib6_walk_continue(w); 1921 if (res <= 0) 1922 fib6_walker_unlink(net, w); 1923 return res; 1924 } 1925 1926 static int fib6_clean_node(struct fib6_walker *w) 1927 { 1928 int res; 1929 struct fib6_info *rt; 1930 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 1931 struct nl_info info = { 1932 .nl_net = c->net, 1933 }; 1934 1935 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 1936 w->node->fn_sernum != c->sernum) 1937 w->node->fn_sernum = c->sernum; 1938 1939 if (!c->func) { 1940 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 1941 w->leaf = NULL; 1942 return 0; 1943 } 1944 1945 for_each_fib6_walker_rt(w) { 1946 res = c->func(rt, c->arg); 1947 if (res == -1) { 1948 w->leaf = rt; 1949 res = fib6_del(rt, &info); 1950 if (res) { 1951 #if RT6_DEBUG >= 2 1952 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 1953 __func__, rt, 1954 rcu_access_pointer(rt->rt6i_node), 1955 res); 1956 #endif 1957 continue; 1958 } 1959 return 0; 1960 } else if (res == -2) { 1961 if (WARN_ON(!rt->rt6i_nsiblings)) 1962 continue; 1963 rt = list_last_entry(&rt->rt6i_siblings, 1964 struct fib6_info, rt6i_siblings); 1965 continue; 1966 } 1967 WARN_ON(res != 0); 1968 } 1969 w->leaf = rt; 1970 return 0; 1971 } 1972 1973 /* 1974 * Convenient frontend to tree walker. 1975 * 1976 * func is called on each route. 1977 * It may return -2 -> skip multipath route. 1978 * -1 -> delete this route. 1979 * 0 -> continue walking 1980 */ 1981 1982 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 1983 int (*func)(struct fib6_info *, void *arg), 1984 int sernum, void *arg) 1985 { 1986 struct fib6_cleaner c; 1987 1988 c.w.root = root; 1989 c.w.func = fib6_clean_node; 1990 c.w.count = 0; 1991 c.w.skip = 0; 1992 c.func = func; 1993 c.sernum = sernum; 1994 c.arg = arg; 1995 c.net = net; 1996 1997 fib6_walk(net, &c.w); 1998 } 1999 2000 static void __fib6_clean_all(struct net *net, 2001 int (*func)(struct fib6_info *, void *), 2002 int sernum, void *arg) 2003 { 2004 struct fib6_table *table; 2005 struct hlist_head *head; 2006 unsigned int h; 2007 2008 rcu_read_lock(); 2009 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 2010 head = &net->ipv6.fib_table_hash[h]; 2011 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 2012 spin_lock_bh(&table->tb6_lock); 2013 fib6_clean_tree(net, &table->tb6_root, 2014 func, sernum, arg); 2015 spin_unlock_bh(&table->tb6_lock); 2016 } 2017 } 2018 rcu_read_unlock(); 2019 } 2020 2021 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *), 2022 void *arg) 2023 { 2024 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg); 2025 } 2026 2027 static void fib6_flush_trees(struct net *net) 2028 { 2029 int new_sernum = fib6_new_sernum(net); 2030 2031 __fib6_clean_all(net, NULL, new_sernum, NULL); 2032 } 2033 2034 /* 2035 * Garbage collection 2036 */ 2037 2038 static int fib6_age(struct fib6_info *rt, void *arg) 2039 { 2040 struct fib6_gc_args *gc_args = arg; 2041 unsigned long now = jiffies; 2042 2043 /* 2044 * check addrconf expiration here. 2045 * Routes are expired even if they are in use. 2046 */ 2047 2048 if (rt->rt6i_flags & RTF_EXPIRES && rt->expires) { 2049 if (time_after(now, rt->expires)) { 2050 RT6_TRACE("expiring %p\n", rt); 2051 return -1; 2052 } 2053 gc_args->more++; 2054 } 2055 2056 /* Also age clones in the exception table. 2057 * Note, that clones are aged out 2058 * only if they are not in use now. 2059 */ 2060 rt6_age_exceptions(rt, gc_args, now); 2061 2062 return 0; 2063 } 2064 2065 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 2066 { 2067 struct fib6_gc_args gc_args; 2068 unsigned long now; 2069 2070 if (force) { 2071 spin_lock_bh(&net->ipv6.fib6_gc_lock); 2072 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) { 2073 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 2074 return; 2075 } 2076 gc_args.timeout = expires ? (int)expires : 2077 net->ipv6.sysctl.ip6_rt_gc_interval; 2078 gc_args.more = 0; 2079 2080 fib6_clean_all(net, fib6_age, &gc_args); 2081 now = jiffies; 2082 net->ipv6.ip6_rt_last_gc = now; 2083 2084 if (gc_args.more) 2085 mod_timer(&net->ipv6.ip6_fib_timer, 2086 round_jiffies(now 2087 + net->ipv6.sysctl.ip6_rt_gc_interval)); 2088 else 2089 del_timer(&net->ipv6.ip6_fib_timer); 2090 spin_unlock_bh(&net->ipv6.fib6_gc_lock); 2091 } 2092 2093 static void fib6_gc_timer_cb(struct timer_list *t) 2094 { 2095 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer); 2096 2097 fib6_run_gc(0, arg, true); 2098 } 2099 2100 static int __net_init fib6_net_init(struct net *net) 2101 { 2102 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 2103 int err; 2104 2105 err = fib6_notifier_init(net); 2106 if (err) 2107 return err; 2108 2109 spin_lock_init(&net->ipv6.fib6_gc_lock); 2110 rwlock_init(&net->ipv6.fib6_walker_lock); 2111 INIT_LIST_HEAD(&net->ipv6.fib6_walkers); 2112 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0); 2113 2114 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 2115 if (!net->ipv6.rt6_stats) 2116 goto out_timer; 2117 2118 /* Avoid false sharing : Use at least a full cache line */ 2119 size = max_t(size_t, size, L1_CACHE_BYTES); 2120 2121 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 2122 if (!net->ipv6.fib_table_hash) 2123 goto out_rt6_stats; 2124 2125 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 2126 GFP_KERNEL); 2127 if (!net->ipv6.fib6_main_tbl) 2128 goto out_fib_table_hash; 2129 2130 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 2131 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf, 2132 net->ipv6.fib6_null_entry); 2133 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 2134 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2135 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 2136 2137 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2138 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 2139 GFP_KERNEL); 2140 if (!net->ipv6.fib6_local_tbl) 2141 goto out_fib6_main_tbl; 2142 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 2143 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf, 2144 net->ipv6.fib6_null_entry); 2145 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 2146 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2147 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 2148 #endif 2149 fib6_tables_init(net); 2150 2151 return 0; 2152 2153 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2154 out_fib6_main_tbl: 2155 kfree(net->ipv6.fib6_main_tbl); 2156 #endif 2157 out_fib_table_hash: 2158 kfree(net->ipv6.fib_table_hash); 2159 out_rt6_stats: 2160 kfree(net->ipv6.rt6_stats); 2161 out_timer: 2162 fib6_notifier_exit(net); 2163 return -ENOMEM; 2164 } 2165 2166 static void fib6_net_exit(struct net *net) 2167 { 2168 unsigned int i; 2169 2170 del_timer_sync(&net->ipv6.ip6_fib_timer); 2171 2172 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) { 2173 struct hlist_head *head = &net->ipv6.fib_table_hash[i]; 2174 struct hlist_node *tmp; 2175 struct fib6_table *tb; 2176 2177 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) { 2178 hlist_del(&tb->tb6_hlist); 2179 fib6_free_table(tb); 2180 } 2181 } 2182 2183 kfree(net->ipv6.fib_table_hash); 2184 kfree(net->ipv6.rt6_stats); 2185 fib6_notifier_exit(net); 2186 } 2187 2188 static struct pernet_operations fib6_net_ops = { 2189 .init = fib6_net_init, 2190 .exit = fib6_net_exit, 2191 }; 2192 2193 int __init fib6_init(void) 2194 { 2195 int ret = -ENOMEM; 2196 2197 fib6_node_kmem = kmem_cache_create("fib6_nodes", 2198 sizeof(struct fib6_node), 2199 0, SLAB_HWCACHE_ALIGN, 2200 NULL); 2201 if (!fib6_node_kmem) 2202 goto out; 2203 2204 ret = register_pernet_subsys(&fib6_net_ops); 2205 if (ret) 2206 goto out_kmem_cache_create; 2207 2208 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL, 2209 inet6_dump_fib, 0); 2210 if (ret) 2211 goto out_unregister_subsys; 2212 2213 __fib6_flush_trees = fib6_flush_trees; 2214 out: 2215 return ret; 2216 2217 out_unregister_subsys: 2218 unregister_pernet_subsys(&fib6_net_ops); 2219 out_kmem_cache_create: 2220 kmem_cache_destroy(fib6_node_kmem); 2221 goto out; 2222 } 2223 2224 void fib6_gc_cleanup(void) 2225 { 2226 unregister_pernet_subsys(&fib6_net_ops); 2227 kmem_cache_destroy(fib6_node_kmem); 2228 } 2229 2230 #ifdef CONFIG_PROC_FS 2231 2232 struct ipv6_route_iter { 2233 struct seq_net_private p; 2234 struct fib6_walker w; 2235 loff_t skip; 2236 struct fib6_table *tbl; 2237 int sernum; 2238 }; 2239 2240 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 2241 { 2242 struct fib6_info *rt = v; 2243 struct ipv6_route_iter *iter = seq->private; 2244 const struct net_device *dev; 2245 2246 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen); 2247 2248 #ifdef CONFIG_IPV6_SUBTREES 2249 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen); 2250 #else 2251 seq_puts(seq, "00000000000000000000000000000000 00 "); 2252 #endif 2253 if (rt->rt6i_flags & RTF_GATEWAY) 2254 seq_printf(seq, "%pi6", &rt->fib6_nh.nh_gw); 2255 else 2256 seq_puts(seq, "00000000000000000000000000000000"); 2257 2258 dev = rt->fib6_nh.nh_dev; 2259 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 2260 rt->rt6i_metric, atomic_read(&rt->rt6i_ref), 0, 2261 rt->rt6i_flags, dev ? dev->name : ""); 2262 iter->w.leaf = NULL; 2263 return 0; 2264 } 2265 2266 static int ipv6_route_yield(struct fib6_walker *w) 2267 { 2268 struct ipv6_route_iter *iter = w->args; 2269 2270 if (!iter->skip) 2271 return 1; 2272 2273 do { 2274 iter->w.leaf = rcu_dereference_protected( 2275 iter->w.leaf->rt6_next, 2276 lockdep_is_held(&iter->tbl->tb6_lock)); 2277 iter->skip--; 2278 if (!iter->skip && iter->w.leaf) 2279 return 1; 2280 } while (iter->w.leaf); 2281 2282 return 0; 2283 } 2284 2285 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter, 2286 struct net *net) 2287 { 2288 memset(&iter->w, 0, sizeof(iter->w)); 2289 iter->w.func = ipv6_route_yield; 2290 iter->w.root = &iter->tbl->tb6_root; 2291 iter->w.state = FWS_INIT; 2292 iter->w.node = iter->w.root; 2293 iter->w.args = iter; 2294 iter->sernum = iter->w.root->fn_sernum; 2295 INIT_LIST_HEAD(&iter->w.lh); 2296 fib6_walker_link(net, &iter->w); 2297 } 2298 2299 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 2300 struct net *net) 2301 { 2302 unsigned int h; 2303 struct hlist_node *node; 2304 2305 if (tbl) { 2306 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 2307 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 2308 } else { 2309 h = 0; 2310 node = NULL; 2311 } 2312 2313 while (!node && h < FIB6_TABLE_HASHSZ) { 2314 node = rcu_dereference_bh( 2315 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 2316 } 2317 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 2318 } 2319 2320 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 2321 { 2322 if (iter->sernum != iter->w.root->fn_sernum) { 2323 iter->sernum = iter->w.root->fn_sernum; 2324 iter->w.state = FWS_INIT; 2325 iter->w.node = iter->w.root; 2326 WARN_ON(iter->w.skip); 2327 iter->w.skip = iter->w.count; 2328 } 2329 } 2330 2331 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2332 { 2333 int r; 2334 struct fib6_info *n; 2335 struct net *net = seq_file_net(seq); 2336 struct ipv6_route_iter *iter = seq->private; 2337 2338 if (!v) 2339 goto iter_table; 2340 2341 n = rcu_dereference_bh(((struct fib6_info *)v)->rt6_next); 2342 if (n) { 2343 ++*pos; 2344 return n; 2345 } 2346 2347 iter_table: 2348 ipv6_route_check_sernum(iter); 2349 spin_lock_bh(&iter->tbl->tb6_lock); 2350 r = fib6_walk_continue(&iter->w); 2351 spin_unlock_bh(&iter->tbl->tb6_lock); 2352 if (r > 0) { 2353 if (v) 2354 ++*pos; 2355 return iter->w.leaf; 2356 } else if (r < 0) { 2357 fib6_walker_unlink(net, &iter->w); 2358 return NULL; 2359 } 2360 fib6_walker_unlink(net, &iter->w); 2361 2362 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 2363 if (!iter->tbl) 2364 return NULL; 2365 2366 ipv6_route_seq_setup_walk(iter, net); 2367 goto iter_table; 2368 } 2369 2370 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 2371 __acquires(RCU_BH) 2372 { 2373 struct net *net = seq_file_net(seq); 2374 struct ipv6_route_iter *iter = seq->private; 2375 2376 rcu_read_lock_bh(); 2377 iter->tbl = ipv6_route_seq_next_table(NULL, net); 2378 iter->skip = *pos; 2379 2380 if (iter->tbl) { 2381 ipv6_route_seq_setup_walk(iter, net); 2382 return ipv6_route_seq_next(seq, NULL, pos); 2383 } else { 2384 return NULL; 2385 } 2386 } 2387 2388 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 2389 { 2390 struct fib6_walker *w = &iter->w; 2391 return w->node && !(w->state == FWS_U && w->node == w->root); 2392 } 2393 2394 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2395 __releases(RCU_BH) 2396 { 2397 struct net *net = seq_file_net(seq); 2398 struct ipv6_route_iter *iter = seq->private; 2399 2400 if (ipv6_route_iter_active(iter)) 2401 fib6_walker_unlink(net, &iter->w); 2402 2403 rcu_read_unlock_bh(); 2404 } 2405 2406 static const struct seq_operations ipv6_route_seq_ops = { 2407 .start = ipv6_route_seq_start, 2408 .next = ipv6_route_seq_next, 2409 .stop = ipv6_route_seq_stop, 2410 .show = ipv6_route_seq_show 2411 }; 2412 2413 int ipv6_route_open(struct inode *inode, struct file *file) 2414 { 2415 return seq_open_net(inode, file, &ipv6_route_seq_ops, 2416 sizeof(struct ipv6_route_iter)); 2417 } 2418 2419 #endif /* CONFIG_PROC_FS */ 2420