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 *f6i) 109 { 110 struct fib6_node *fn; 111 112 fn = rcu_dereference_protected(f6i->fib6_node, 113 lockdep_is_held(&f6i->fib6_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->fib6_siblings); 163 f6i->fib6_metrics = (struct dst_metrics *)&dst_default_metrics; 164 165 atomic_inc(&f6i->fib6_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->fib6_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->fib6_nh.nh_dev) 201 dev_put(f6i->fib6_nh.nh_dev); 202 203 m = f6i->fib6_metrics; 204 if (m != &dst_default_metrics && refcount_dec_and_test(&m->refcnt)) 205 kfree(m); 206 207 kfree(f6i); 208 } 209 EXPORT_SYMBOL_GPL(fib6_info_destroy); 210 211 static struct fib6_node *node_alloc(struct net *net) 212 { 213 struct fib6_node *fn; 214 215 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); 216 if (fn) 217 net->ipv6.rt6_stats->fib_nodes++; 218 219 return fn; 220 } 221 222 static void node_free_immediate(struct net *net, struct fib6_node *fn) 223 { 224 kmem_cache_free(fib6_node_kmem, fn); 225 net->ipv6.rt6_stats->fib_nodes--; 226 } 227 228 static void node_free_rcu(struct rcu_head *head) 229 { 230 struct fib6_node *fn = container_of(head, struct fib6_node, rcu); 231 232 kmem_cache_free(fib6_node_kmem, fn); 233 } 234 235 static void node_free(struct net *net, struct fib6_node *fn) 236 { 237 call_rcu(&fn->rcu, node_free_rcu); 238 net->ipv6.rt6_stats->fib_nodes--; 239 } 240 241 static void fib6_free_table(struct fib6_table *table) 242 { 243 inetpeer_invalidate_tree(&table->tb6_peers); 244 kfree(table); 245 } 246 247 static void fib6_link_table(struct net *net, struct fib6_table *tb) 248 { 249 unsigned int h; 250 251 /* 252 * Initialize table lock at a single place to give lockdep a key, 253 * tables aren't visible prior to being linked to the list. 254 */ 255 spin_lock_init(&tb->tb6_lock); 256 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 257 258 /* 259 * No protection necessary, this is the only list mutatation 260 * operation, tables never disappear once they exist. 261 */ 262 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 263 } 264 265 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 266 267 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 268 { 269 struct fib6_table *table; 270 271 table = kzalloc(sizeof(*table), GFP_ATOMIC); 272 if (table) { 273 table->tb6_id = id; 274 rcu_assign_pointer(table->tb6_root.leaf, 275 net->ipv6.fib6_null_entry); 276 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 277 inet_peer_base_init(&table->tb6_peers); 278 } 279 280 return table; 281 } 282 283 struct fib6_table *fib6_new_table(struct net *net, u32 id) 284 { 285 struct fib6_table *tb; 286 287 if (id == 0) 288 id = RT6_TABLE_MAIN; 289 tb = fib6_get_table(net, id); 290 if (tb) 291 return tb; 292 293 tb = fib6_alloc_table(net, id); 294 if (tb) 295 fib6_link_table(net, tb); 296 297 return tb; 298 } 299 EXPORT_SYMBOL_GPL(fib6_new_table); 300 301 struct fib6_table *fib6_get_table(struct net *net, u32 id) 302 { 303 struct fib6_table *tb; 304 struct hlist_head *head; 305 unsigned int h; 306 307 if (id == 0) 308 id = RT6_TABLE_MAIN; 309 h = id & (FIB6_TABLE_HASHSZ - 1); 310 rcu_read_lock(); 311 head = &net->ipv6.fib_table_hash[h]; 312 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 313 if (tb->tb6_id == id) { 314 rcu_read_unlock(); 315 return tb; 316 } 317 } 318 rcu_read_unlock(); 319 320 return NULL; 321 } 322 EXPORT_SYMBOL_GPL(fib6_get_table); 323 324 static void __net_init fib6_tables_init(struct net *net) 325 { 326 fib6_link_table(net, net->ipv6.fib6_main_tbl); 327 fib6_link_table(net, net->ipv6.fib6_local_tbl); 328 } 329 #else 330 331 struct fib6_table *fib6_new_table(struct net *net, u32 id) 332 { 333 return fib6_get_table(net, id); 334 } 335 336 struct fib6_table *fib6_get_table(struct net *net, u32 id) 337 { 338 return net->ipv6.fib6_main_tbl; 339 } 340 341 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 342 const struct sk_buff *skb, 343 int flags, pol_lookup_t lookup) 344 { 345 struct rt6_info *rt; 346 347 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags); 348 if (rt->dst.error == -EAGAIN) { 349 ip6_rt_put(rt); 350 rt = net->ipv6.ip6_null_entry; 351 dst_hold(&rt->dst); 352 } 353 354 return &rt->dst; 355 } 356 357 /* called with rcu lock held; no reference taken on fib6_info */ 358 struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 359 int flags) 360 { 361 return fib6_table_lookup(net, net->ipv6.fib6_main_tbl, oif, fl6, flags); 362 } 363 364 static void __net_init fib6_tables_init(struct net *net) 365 { 366 fib6_link_table(net, net->ipv6.fib6_main_tbl); 367 } 368 369 #endif 370 371 unsigned int fib6_tables_seq_read(struct net *net) 372 { 373 unsigned int h, fib_seq = 0; 374 375 rcu_read_lock(); 376 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 377 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 378 struct fib6_table *tb; 379 380 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 381 fib_seq += tb->fib_seq; 382 } 383 rcu_read_unlock(); 384 385 return fib_seq; 386 } 387 388 static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net, 389 enum fib_event_type event_type, 390 struct fib6_info *rt) 391 { 392 struct fib6_entry_notifier_info info = { 393 .rt = rt, 394 }; 395 396 return call_fib6_notifier(nb, net, event_type, &info.info); 397 } 398 399 static int call_fib6_entry_notifiers(struct net *net, 400 enum fib_event_type event_type, 401 struct fib6_info *rt, 402 struct netlink_ext_ack *extack) 403 { 404 struct fib6_entry_notifier_info info = { 405 .info.extack = extack, 406 .rt = rt, 407 }; 408 409 rt->fib6_table->fib_seq++; 410 return call_fib6_notifiers(net, event_type, &info.info); 411 } 412 413 struct fib6_dump_arg { 414 struct net *net; 415 struct notifier_block *nb; 416 }; 417 418 static void fib6_rt_dump(struct fib6_info *rt, struct fib6_dump_arg *arg) 419 { 420 if (rt == arg->net->ipv6.fib6_null_entry) 421 return; 422 call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt); 423 } 424 425 static int fib6_node_dump(struct fib6_walker *w) 426 { 427 struct fib6_info *rt; 428 429 for_each_fib6_walker_rt(w) 430 fib6_rt_dump(rt, w->args); 431 w->leaf = NULL; 432 return 0; 433 } 434 435 static void fib6_table_dump(struct net *net, struct fib6_table *tb, 436 struct fib6_walker *w) 437 { 438 w->root = &tb->tb6_root; 439 spin_lock_bh(&tb->tb6_lock); 440 fib6_walk(net, w); 441 spin_unlock_bh(&tb->tb6_lock); 442 } 443 444 /* Called with rcu_read_lock() */ 445 int fib6_tables_dump(struct net *net, struct notifier_block *nb) 446 { 447 struct fib6_dump_arg arg; 448 struct fib6_walker *w; 449 unsigned int h; 450 451 w = kzalloc(sizeof(*w), GFP_ATOMIC); 452 if (!w) 453 return -ENOMEM; 454 455 w->func = fib6_node_dump; 456 arg.net = net; 457 arg.nb = nb; 458 w->args = &arg; 459 460 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 461 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 462 struct fib6_table *tb; 463 464 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 465 fib6_table_dump(net, tb, w); 466 } 467 468 kfree(w); 469 470 return 0; 471 } 472 473 static int fib6_dump_node(struct fib6_walker *w) 474 { 475 int res; 476 struct fib6_info *rt; 477 478 for_each_fib6_walker_rt(w) { 479 res = rt6_dump_route(rt, w->args); 480 if (res < 0) { 481 /* Frame is full, suspend walking */ 482 w->leaf = rt; 483 return 1; 484 } 485 486 /* Multipath routes are dumped in one route with the 487 * RTA_MULTIPATH attribute. Jump 'rt' to point to the 488 * last sibling of this route (no need to dump the 489 * sibling routes again) 490 */ 491 if (rt->fib6_nsiblings) 492 rt = list_last_entry(&rt->fib6_siblings, 493 struct fib6_info, 494 fib6_siblings); 495 } 496 w->leaf = NULL; 497 return 0; 498 } 499 500 static void fib6_dump_end(struct netlink_callback *cb) 501 { 502 struct net *net = sock_net(cb->skb->sk); 503 struct fib6_walker *w = (void *)cb->args[2]; 504 505 if (w) { 506 if (cb->args[4]) { 507 cb->args[4] = 0; 508 fib6_walker_unlink(net, w); 509 } 510 cb->args[2] = 0; 511 kfree(w); 512 } 513 cb->done = (void *)cb->args[3]; 514 cb->args[1] = 3; 515 } 516 517 static int fib6_dump_done(struct netlink_callback *cb) 518 { 519 fib6_dump_end(cb); 520 return cb->done ? cb->done(cb) : 0; 521 } 522 523 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 524 struct netlink_callback *cb) 525 { 526 struct net *net = sock_net(skb->sk); 527 struct fib6_walker *w; 528 int res; 529 530 w = (void *)cb->args[2]; 531 w->root = &table->tb6_root; 532 533 if (cb->args[4] == 0) { 534 w->count = 0; 535 w->skip = 0; 536 537 spin_lock_bh(&table->tb6_lock); 538 res = fib6_walk(net, w); 539 spin_unlock_bh(&table->tb6_lock); 540 if (res > 0) { 541 cb->args[4] = 1; 542 cb->args[5] = w->root->fn_sernum; 543 } 544 } else { 545 if (cb->args[5] != w->root->fn_sernum) { 546 /* Begin at the root if the tree changed */ 547 cb->args[5] = w->root->fn_sernum; 548 w->state = FWS_INIT; 549 w->node = w->root; 550 w->skip = w->count; 551 } else 552 w->skip = 0; 553 554 spin_lock_bh(&table->tb6_lock); 555 res = fib6_walk_continue(w); 556 spin_unlock_bh(&table->tb6_lock); 557 if (res <= 0) { 558 fib6_walker_unlink(net, w); 559 cb->args[4] = 0; 560 } 561 } 562 563 return res; 564 } 565 566 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 567 { 568 struct net *net = sock_net(skb->sk); 569 unsigned int h, s_h; 570 unsigned int e = 0, s_e; 571 struct rt6_rtnl_dump_arg arg; 572 struct fib6_walker *w; 573 struct fib6_table *tb; 574 struct hlist_head *head; 575 int res = 0; 576 577 s_h = cb->args[0]; 578 s_e = cb->args[1]; 579 580 w = (void *)cb->args[2]; 581 if (!w) { 582 /* New dump: 583 * 584 * 1. hook callback destructor. 585 */ 586 cb->args[3] = (long)cb->done; 587 cb->done = fib6_dump_done; 588 589 /* 590 * 2. allocate and initialize walker. 591 */ 592 w = kzalloc(sizeof(*w), GFP_ATOMIC); 593 if (!w) 594 return -ENOMEM; 595 w->func = fib6_dump_node; 596 cb->args[2] = (long)w; 597 } 598 599 arg.skb = skb; 600 arg.cb = cb; 601 arg.net = net; 602 w->args = &arg; 603 604 rcu_read_lock(); 605 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 606 e = 0; 607 head = &net->ipv6.fib_table_hash[h]; 608 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 609 if (e < s_e) 610 goto next; 611 res = fib6_dump_table(tb, skb, cb); 612 if (res != 0) 613 goto out; 614 next: 615 e++; 616 } 617 } 618 out: 619 rcu_read_unlock(); 620 cb->args[1] = e; 621 cb->args[0] = h; 622 623 res = res < 0 ? res : skb->len; 624 if (res <= 0) 625 fib6_dump_end(cb); 626 return res; 627 } 628 629 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val) 630 { 631 if (!f6i) 632 return; 633 634 if (f6i->fib6_metrics == &dst_default_metrics) { 635 struct dst_metrics *p = kzalloc(sizeof(*p), GFP_ATOMIC); 636 637 if (!p) 638 return; 639 640 refcount_set(&p->refcnt, 1); 641 f6i->fib6_metrics = p; 642 } 643 644 f6i->fib6_metrics->metrics[metric - 1] = val; 645 } 646 647 /* 648 * Routing Table 649 * 650 * return the appropriate node for a routing tree "add" operation 651 * by either creating and inserting or by returning an existing 652 * node. 653 */ 654 655 static struct fib6_node *fib6_add_1(struct net *net, 656 struct fib6_table *table, 657 struct fib6_node *root, 658 struct in6_addr *addr, int plen, 659 int offset, int allow_create, 660 int replace_required, 661 struct netlink_ext_ack *extack) 662 { 663 struct fib6_node *fn, *in, *ln; 664 struct fib6_node *pn = NULL; 665 struct rt6key *key; 666 int bit; 667 __be32 dir = 0; 668 669 RT6_TRACE("fib6_add_1\n"); 670 671 /* insert node in tree */ 672 673 fn = root; 674 675 do { 676 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 677 lockdep_is_held(&table->tb6_lock)); 678 key = (struct rt6key *)((u8 *)leaf + offset); 679 680 /* 681 * Prefix match 682 */ 683 if (plen < fn->fn_bit || 684 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 685 if (!allow_create) { 686 if (replace_required) { 687 NL_SET_ERR_MSG(extack, 688 "Can not replace route - no match found"); 689 pr_warn("Can't replace route, no match found\n"); 690 return ERR_PTR(-ENOENT); 691 } 692 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 693 } 694 goto insert_above; 695 } 696 697 /* 698 * Exact match ? 699 */ 700 701 if (plen == fn->fn_bit) { 702 /* clean up an intermediate node */ 703 if (!(fn->fn_flags & RTN_RTINFO)) { 704 RCU_INIT_POINTER(fn->leaf, NULL); 705 fib6_info_release(leaf); 706 /* remove null_entry in the root node */ 707 } else if (fn->fn_flags & RTN_TL_ROOT && 708 rcu_access_pointer(fn->leaf) == 709 net->ipv6.fib6_null_entry) { 710 RCU_INIT_POINTER(fn->leaf, NULL); 711 } 712 713 return fn; 714 } 715 716 /* 717 * We have more bits to go 718 */ 719 720 /* Try to walk down on tree. */ 721 dir = addr_bit_set(addr, fn->fn_bit); 722 pn = fn; 723 fn = dir ? 724 rcu_dereference_protected(fn->right, 725 lockdep_is_held(&table->tb6_lock)) : 726 rcu_dereference_protected(fn->left, 727 lockdep_is_held(&table->tb6_lock)); 728 } while (fn); 729 730 if (!allow_create) { 731 /* We should not create new node because 732 * NLM_F_REPLACE was specified without NLM_F_CREATE 733 * I assume it is safe to require NLM_F_CREATE when 734 * REPLACE flag is used! Later we may want to remove the 735 * check for replace_required, because according 736 * to netlink specification, NLM_F_CREATE 737 * MUST be specified if new route is created. 738 * That would keep IPv6 consistent with IPv4 739 */ 740 if (replace_required) { 741 NL_SET_ERR_MSG(extack, 742 "Can not replace route - no match found"); 743 pr_warn("Can't replace route, no match found\n"); 744 return ERR_PTR(-ENOENT); 745 } 746 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 747 } 748 /* 749 * We walked to the bottom of tree. 750 * Create new leaf node without children. 751 */ 752 753 ln = node_alloc(net); 754 755 if (!ln) 756 return ERR_PTR(-ENOMEM); 757 ln->fn_bit = plen; 758 RCU_INIT_POINTER(ln->parent, pn); 759 760 if (dir) 761 rcu_assign_pointer(pn->right, ln); 762 else 763 rcu_assign_pointer(pn->left, ln); 764 765 return ln; 766 767 768 insert_above: 769 /* 770 * split since we don't have a common prefix anymore or 771 * we have a less significant route. 772 * we've to insert an intermediate node on the list 773 * this new node will point to the one we need to create 774 * and the current 775 */ 776 777 pn = rcu_dereference_protected(fn->parent, 778 lockdep_is_held(&table->tb6_lock)); 779 780 /* find 1st bit in difference between the 2 addrs. 781 782 See comment in __ipv6_addr_diff: bit may be an invalid value, 783 but if it is >= plen, the value is ignored in any case. 784 */ 785 786 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 787 788 /* 789 * (intermediate)[in] 790 * / \ 791 * (new leaf node)[ln] (old node)[fn] 792 */ 793 if (plen > bit) { 794 in = node_alloc(net); 795 ln = node_alloc(net); 796 797 if (!in || !ln) { 798 if (in) 799 node_free_immediate(net, in); 800 if (ln) 801 node_free_immediate(net, ln); 802 return ERR_PTR(-ENOMEM); 803 } 804 805 /* 806 * new intermediate node. 807 * RTN_RTINFO will 808 * be off since that an address that chooses one of 809 * the branches would not match less specific routes 810 * in the other branch 811 */ 812 813 in->fn_bit = bit; 814 815 RCU_INIT_POINTER(in->parent, pn); 816 in->leaf = fn->leaf; 817 atomic_inc(&rcu_dereference_protected(in->leaf, 818 lockdep_is_held(&table->tb6_lock))->fib6_ref); 819 820 /* update parent pointer */ 821 if (dir) 822 rcu_assign_pointer(pn->right, in); 823 else 824 rcu_assign_pointer(pn->left, in); 825 826 ln->fn_bit = plen; 827 828 RCU_INIT_POINTER(ln->parent, in); 829 rcu_assign_pointer(fn->parent, in); 830 831 if (addr_bit_set(addr, bit)) { 832 rcu_assign_pointer(in->right, ln); 833 rcu_assign_pointer(in->left, fn); 834 } else { 835 rcu_assign_pointer(in->left, ln); 836 rcu_assign_pointer(in->right, fn); 837 } 838 } else { /* plen <= bit */ 839 840 /* 841 * (new leaf node)[ln] 842 * / \ 843 * (old node)[fn] NULL 844 */ 845 846 ln = node_alloc(net); 847 848 if (!ln) 849 return ERR_PTR(-ENOMEM); 850 851 ln->fn_bit = plen; 852 853 RCU_INIT_POINTER(ln->parent, pn); 854 855 if (addr_bit_set(&key->addr, plen)) 856 RCU_INIT_POINTER(ln->right, fn); 857 else 858 RCU_INIT_POINTER(ln->left, fn); 859 860 rcu_assign_pointer(fn->parent, ln); 861 862 if (dir) 863 rcu_assign_pointer(pn->right, ln); 864 else 865 rcu_assign_pointer(pn->left, ln); 866 } 867 return ln; 868 } 869 870 static void fib6_drop_pcpu_from(struct fib6_info *f6i, 871 const struct fib6_table *table) 872 { 873 int cpu; 874 875 /* release the reference to this fib entry from 876 * all of its cached pcpu routes 877 */ 878 for_each_possible_cpu(cpu) { 879 struct rt6_info **ppcpu_rt; 880 struct rt6_info *pcpu_rt; 881 882 ppcpu_rt = per_cpu_ptr(f6i->rt6i_pcpu, cpu); 883 pcpu_rt = *ppcpu_rt; 884 if (pcpu_rt) { 885 struct fib6_info *from; 886 887 from = rcu_dereference_protected(pcpu_rt->from, 888 lockdep_is_held(&table->tb6_lock)); 889 rcu_assign_pointer(pcpu_rt->from, NULL); 890 fib6_info_release(from); 891 } 892 } 893 } 894 895 static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn, 896 struct net *net) 897 { 898 struct fib6_table *table = rt->fib6_table; 899 900 if (atomic_read(&rt->fib6_ref) != 1) { 901 /* This route is used as dummy address holder in some split 902 * nodes. It is not leaked, but it still holds other resources, 903 * which must be released in time. So, scan ascendant nodes 904 * and replace dummy references to this route with references 905 * to still alive ones. 906 */ 907 while (fn) { 908 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 909 lockdep_is_held(&table->tb6_lock)); 910 struct fib6_info *new_leaf; 911 if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) { 912 new_leaf = fib6_find_prefix(net, table, fn); 913 atomic_inc(&new_leaf->fib6_ref); 914 915 rcu_assign_pointer(fn->leaf, new_leaf); 916 fib6_info_release(rt); 917 } 918 fn = rcu_dereference_protected(fn->parent, 919 lockdep_is_held(&table->tb6_lock)); 920 } 921 922 if (rt->rt6i_pcpu) 923 fib6_drop_pcpu_from(rt, table); 924 } 925 } 926 927 /* 928 * Insert routing information in a node. 929 */ 930 931 static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt, 932 struct nl_info *info, 933 struct netlink_ext_ack *extack) 934 { 935 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 936 lockdep_is_held(&rt->fib6_table->tb6_lock)); 937 struct fib6_info *iter = NULL; 938 struct fib6_info __rcu **ins; 939 struct fib6_info __rcu **fallback_ins = NULL; 940 int replace = (info->nlh && 941 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 942 int add = (!info->nlh || 943 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 944 int found = 0; 945 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 946 u16 nlflags = NLM_F_EXCL; 947 int err; 948 949 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND)) 950 nlflags |= NLM_F_APPEND; 951 952 ins = &fn->leaf; 953 954 for (iter = leaf; iter; 955 iter = rcu_dereference_protected(iter->fib6_next, 956 lockdep_is_held(&rt->fib6_table->tb6_lock))) { 957 /* 958 * Search for duplicates 959 */ 960 961 if (iter->fib6_metric == rt->fib6_metric) { 962 /* 963 * Same priority level 964 */ 965 if (info->nlh && 966 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 967 return -EEXIST; 968 969 nlflags &= ~NLM_F_EXCL; 970 if (replace) { 971 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) { 972 found++; 973 break; 974 } 975 if (rt_can_ecmp) 976 fallback_ins = fallback_ins ?: ins; 977 goto next_iter; 978 } 979 980 if (rt6_duplicate_nexthop(iter, rt)) { 981 if (rt->fib6_nsiblings) 982 rt->fib6_nsiblings = 0; 983 if (!(iter->fib6_flags & RTF_EXPIRES)) 984 return -EEXIST; 985 if (!(rt->fib6_flags & RTF_EXPIRES)) 986 fib6_clean_expires(iter); 987 else 988 fib6_set_expires(iter, rt->expires); 989 fib6_metric_set(iter, RTAX_MTU, rt->fib6_pmtu); 990 return -EEXIST; 991 } 992 /* If we have the same destination and the same metric, 993 * but not the same gateway, then the route we try to 994 * add is sibling to this route, increment our counter 995 * of siblings, and later we will add our route to the 996 * list. 997 * Only static routes (which don't have flag 998 * RTF_EXPIRES) are used for ECMPv6. 999 * 1000 * To avoid long list, we only had siblings if the 1001 * route have a gateway. 1002 */ 1003 if (rt_can_ecmp && 1004 rt6_qualify_for_ecmp(iter)) 1005 rt->fib6_nsiblings++; 1006 } 1007 1008 if (iter->fib6_metric > rt->fib6_metric) 1009 break; 1010 1011 next_iter: 1012 ins = &iter->fib6_next; 1013 } 1014 1015 if (fallback_ins && !found) { 1016 /* No ECMP-able route found, replace first non-ECMP one */ 1017 ins = fallback_ins; 1018 iter = rcu_dereference_protected(*ins, 1019 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1020 found++; 1021 } 1022 1023 /* Reset round-robin state, if necessary */ 1024 if (ins == &fn->leaf) 1025 fn->rr_ptr = NULL; 1026 1027 /* Link this route to others same route. */ 1028 if (rt->fib6_nsiblings) { 1029 unsigned int fib6_nsiblings; 1030 struct fib6_info *sibling, *temp_sibling; 1031 1032 /* Find the first route that have the same metric */ 1033 sibling = leaf; 1034 while (sibling) { 1035 if (sibling->fib6_metric == rt->fib6_metric && 1036 rt6_qualify_for_ecmp(sibling)) { 1037 list_add_tail(&rt->fib6_siblings, 1038 &sibling->fib6_siblings); 1039 break; 1040 } 1041 sibling = rcu_dereference_protected(sibling->fib6_next, 1042 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1043 } 1044 /* For each sibling in the list, increment the counter of 1045 * siblings. BUG() if counters does not match, list of siblings 1046 * is broken! 1047 */ 1048 fib6_nsiblings = 0; 1049 list_for_each_entry_safe(sibling, temp_sibling, 1050 &rt->fib6_siblings, fib6_siblings) { 1051 sibling->fib6_nsiblings++; 1052 BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings); 1053 fib6_nsiblings++; 1054 } 1055 BUG_ON(fib6_nsiblings != rt->fib6_nsiblings); 1056 rt6_multipath_rebalance(temp_sibling); 1057 } 1058 1059 /* 1060 * insert node 1061 */ 1062 if (!replace) { 1063 if (!add) 1064 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 1065 1066 add: 1067 nlflags |= NLM_F_CREATE; 1068 1069 err = call_fib6_entry_notifiers(info->nl_net, 1070 FIB_EVENT_ENTRY_ADD, 1071 rt, extack); 1072 if (err) 1073 return err; 1074 1075 rcu_assign_pointer(rt->fib6_next, iter); 1076 atomic_inc(&rt->fib6_ref); 1077 rcu_assign_pointer(rt->fib6_node, fn); 1078 rcu_assign_pointer(*ins, rt); 1079 if (!info->skip_notify) 1080 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); 1081 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 1082 1083 if (!(fn->fn_flags & RTN_RTINFO)) { 1084 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1085 fn->fn_flags |= RTN_RTINFO; 1086 } 1087 1088 } else { 1089 int nsiblings; 1090 1091 if (!found) { 1092 if (add) 1093 goto add; 1094 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 1095 return -ENOENT; 1096 } 1097 1098 err = call_fib6_entry_notifiers(info->nl_net, 1099 FIB_EVENT_ENTRY_REPLACE, 1100 rt, extack); 1101 if (err) 1102 return err; 1103 1104 atomic_inc(&rt->fib6_ref); 1105 rcu_assign_pointer(rt->fib6_node, fn); 1106 rt->fib6_next = iter->fib6_next; 1107 rcu_assign_pointer(*ins, rt); 1108 if (!info->skip_notify) 1109 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); 1110 if (!(fn->fn_flags & RTN_RTINFO)) { 1111 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1112 fn->fn_flags |= RTN_RTINFO; 1113 } 1114 nsiblings = iter->fib6_nsiblings; 1115 iter->fib6_node = NULL; 1116 fib6_purge_rt(iter, fn, info->nl_net); 1117 if (rcu_access_pointer(fn->rr_ptr) == iter) 1118 fn->rr_ptr = NULL; 1119 fib6_info_release(iter); 1120 1121 if (nsiblings) { 1122 /* Replacing an ECMP route, remove all siblings */ 1123 ins = &rt->fib6_next; 1124 iter = rcu_dereference_protected(*ins, 1125 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1126 while (iter) { 1127 if (iter->fib6_metric > rt->fib6_metric) 1128 break; 1129 if (rt6_qualify_for_ecmp(iter)) { 1130 *ins = iter->fib6_next; 1131 iter->fib6_node = NULL; 1132 fib6_purge_rt(iter, fn, info->nl_net); 1133 if (rcu_access_pointer(fn->rr_ptr) == iter) 1134 fn->rr_ptr = NULL; 1135 fib6_info_release(iter); 1136 nsiblings--; 1137 info->nl_net->ipv6.rt6_stats->fib_rt_entries--; 1138 } else { 1139 ins = &iter->fib6_next; 1140 } 1141 iter = rcu_dereference_protected(*ins, 1142 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1143 } 1144 WARN_ON(nsiblings != 0); 1145 } 1146 } 1147 1148 return 0; 1149 } 1150 1151 static void fib6_start_gc(struct net *net, struct fib6_info *rt) 1152 { 1153 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 1154 (rt->fib6_flags & RTF_EXPIRES)) 1155 mod_timer(&net->ipv6.ip6_fib_timer, 1156 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1157 } 1158 1159 void fib6_force_start_gc(struct net *net) 1160 { 1161 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 1162 mod_timer(&net->ipv6.ip6_fib_timer, 1163 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1164 } 1165 1166 static void __fib6_update_sernum_upto_root(struct fib6_info *rt, 1167 int sernum) 1168 { 1169 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1170 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1171 1172 /* paired with smp_rmb() in rt6_get_cookie_safe() */ 1173 smp_wmb(); 1174 while (fn) { 1175 fn->fn_sernum = sernum; 1176 fn = rcu_dereference_protected(fn->parent, 1177 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1178 } 1179 } 1180 1181 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt) 1182 { 1183 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net)); 1184 } 1185 1186 /* 1187 * Add routing information to the routing tree. 1188 * <destination addr>/<source addr> 1189 * with source addr info in sub-trees 1190 * Need to own table->tb6_lock 1191 */ 1192 1193 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 1194 struct nl_info *info, struct netlink_ext_ack *extack) 1195 { 1196 struct fib6_table *table = rt->fib6_table; 1197 struct fib6_node *fn, *pn = NULL; 1198 int err = -ENOMEM; 1199 int allow_create = 1; 1200 int replace_required = 0; 1201 int sernum = fib6_new_sernum(info->nl_net); 1202 1203 if (info->nlh) { 1204 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 1205 allow_create = 0; 1206 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 1207 replace_required = 1; 1208 } 1209 if (!allow_create && !replace_required) 1210 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 1211 1212 fn = fib6_add_1(info->nl_net, table, root, 1213 &rt->fib6_dst.addr, rt->fib6_dst.plen, 1214 offsetof(struct fib6_info, fib6_dst), allow_create, 1215 replace_required, extack); 1216 if (IS_ERR(fn)) { 1217 err = PTR_ERR(fn); 1218 fn = NULL; 1219 goto out; 1220 } 1221 1222 pn = fn; 1223 1224 #ifdef CONFIG_IPV6_SUBTREES 1225 if (rt->fib6_src.plen) { 1226 struct fib6_node *sn; 1227 1228 if (!rcu_access_pointer(fn->subtree)) { 1229 struct fib6_node *sfn; 1230 1231 /* 1232 * Create subtree. 1233 * 1234 * fn[main tree] 1235 * | 1236 * sfn[subtree root] 1237 * \ 1238 * sn[new leaf node] 1239 */ 1240 1241 /* Create subtree root node */ 1242 sfn = node_alloc(info->nl_net); 1243 if (!sfn) 1244 goto failure; 1245 1246 atomic_inc(&info->nl_net->ipv6.fib6_null_entry->fib6_ref); 1247 rcu_assign_pointer(sfn->leaf, 1248 info->nl_net->ipv6.fib6_null_entry); 1249 sfn->fn_flags = RTN_ROOT; 1250 1251 /* Now add the first leaf node to new subtree */ 1252 1253 sn = fib6_add_1(info->nl_net, table, sfn, 1254 &rt->fib6_src.addr, rt->fib6_src.plen, 1255 offsetof(struct fib6_info, fib6_src), 1256 allow_create, replace_required, extack); 1257 1258 if (IS_ERR(sn)) { 1259 /* If it is failed, discard just allocated 1260 root, and then (in failure) stale node 1261 in main tree. 1262 */ 1263 node_free_immediate(info->nl_net, sfn); 1264 err = PTR_ERR(sn); 1265 goto failure; 1266 } 1267 1268 /* Now link new subtree to main tree */ 1269 rcu_assign_pointer(sfn->parent, fn); 1270 rcu_assign_pointer(fn->subtree, sfn); 1271 } else { 1272 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn), 1273 &rt->fib6_src.addr, rt->fib6_src.plen, 1274 offsetof(struct fib6_info, fib6_src), 1275 allow_create, replace_required, extack); 1276 1277 if (IS_ERR(sn)) { 1278 err = PTR_ERR(sn); 1279 goto failure; 1280 } 1281 } 1282 1283 if (!rcu_access_pointer(fn->leaf)) { 1284 if (fn->fn_flags & RTN_TL_ROOT) { 1285 /* put back null_entry for root node */ 1286 rcu_assign_pointer(fn->leaf, 1287 info->nl_net->ipv6.fib6_null_entry); 1288 } else { 1289 atomic_inc(&rt->fib6_ref); 1290 rcu_assign_pointer(fn->leaf, rt); 1291 } 1292 } 1293 fn = sn; 1294 } 1295 #endif 1296 1297 err = fib6_add_rt2node(fn, rt, info, extack); 1298 if (!err) { 1299 __fib6_update_sernum_upto_root(rt, sernum); 1300 fib6_start_gc(info->nl_net, rt); 1301 } 1302 1303 out: 1304 if (err) { 1305 #ifdef CONFIG_IPV6_SUBTREES 1306 /* 1307 * If fib6_add_1 has cleared the old leaf pointer in the 1308 * super-tree leaf node we have to find a new one for it. 1309 */ 1310 if (pn != fn) { 1311 struct fib6_info *pn_leaf = 1312 rcu_dereference_protected(pn->leaf, 1313 lockdep_is_held(&table->tb6_lock)); 1314 if (pn_leaf == rt) { 1315 pn_leaf = NULL; 1316 RCU_INIT_POINTER(pn->leaf, NULL); 1317 fib6_info_release(rt); 1318 } 1319 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) { 1320 pn_leaf = fib6_find_prefix(info->nl_net, table, 1321 pn); 1322 #if RT6_DEBUG >= 2 1323 if (!pn_leaf) { 1324 WARN_ON(!pn_leaf); 1325 pn_leaf = 1326 info->nl_net->ipv6.fib6_null_entry; 1327 } 1328 #endif 1329 fib6_info_hold(pn_leaf); 1330 rcu_assign_pointer(pn->leaf, pn_leaf); 1331 } 1332 } 1333 #endif 1334 goto failure; 1335 } 1336 return err; 1337 1338 failure: 1339 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if: 1340 * 1. fn is an intermediate node and we failed to add the new 1341 * route to it in both subtree creation failure and fib6_add_rt2node() 1342 * failure case. 1343 * 2. fn is the root node in the table and we fail to add the first 1344 * default route to it. 1345 */ 1346 if (fn && 1347 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) || 1348 (fn->fn_flags & RTN_TL_ROOT && 1349 !rcu_access_pointer(fn->leaf)))) 1350 fib6_repair_tree(info->nl_net, table, fn); 1351 return err; 1352 } 1353 1354 /* 1355 * Routing tree lookup 1356 * 1357 */ 1358 1359 struct lookup_args { 1360 int offset; /* key offset on fib6_info */ 1361 const struct in6_addr *addr; /* search key */ 1362 }; 1363 1364 static struct fib6_node *fib6_node_lookup_1(struct fib6_node *root, 1365 struct lookup_args *args) 1366 { 1367 struct fib6_node *fn; 1368 __be32 dir; 1369 1370 if (unlikely(args->offset == 0)) 1371 return NULL; 1372 1373 /* 1374 * Descend on a tree 1375 */ 1376 1377 fn = root; 1378 1379 for (;;) { 1380 struct fib6_node *next; 1381 1382 dir = addr_bit_set(args->addr, fn->fn_bit); 1383 1384 next = dir ? rcu_dereference(fn->right) : 1385 rcu_dereference(fn->left); 1386 1387 if (next) { 1388 fn = next; 1389 continue; 1390 } 1391 break; 1392 } 1393 1394 while (fn) { 1395 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1396 1397 if (subtree || fn->fn_flags & RTN_RTINFO) { 1398 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1399 struct rt6key *key; 1400 1401 if (!leaf) 1402 goto backtrack; 1403 1404 key = (struct rt6key *) ((u8 *)leaf + args->offset); 1405 1406 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1407 #ifdef CONFIG_IPV6_SUBTREES 1408 if (subtree) { 1409 struct fib6_node *sfn; 1410 sfn = fib6_node_lookup_1(subtree, 1411 args + 1); 1412 if (!sfn) 1413 goto backtrack; 1414 fn = sfn; 1415 } 1416 #endif 1417 if (fn->fn_flags & RTN_RTINFO) 1418 return fn; 1419 } 1420 } 1421 backtrack: 1422 if (fn->fn_flags & RTN_ROOT) 1423 break; 1424 1425 fn = rcu_dereference(fn->parent); 1426 } 1427 1428 return NULL; 1429 } 1430 1431 /* called with rcu_read_lock() held 1432 */ 1433 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 1434 const struct in6_addr *daddr, 1435 const struct in6_addr *saddr) 1436 { 1437 struct fib6_node *fn; 1438 struct lookup_args args[] = { 1439 { 1440 .offset = offsetof(struct fib6_info, fib6_dst), 1441 .addr = daddr, 1442 }, 1443 #ifdef CONFIG_IPV6_SUBTREES 1444 { 1445 .offset = offsetof(struct fib6_info, fib6_src), 1446 .addr = saddr, 1447 }, 1448 #endif 1449 { 1450 .offset = 0, /* sentinel */ 1451 } 1452 }; 1453 1454 fn = fib6_node_lookup_1(root, daddr ? args : args + 1); 1455 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1456 fn = root; 1457 1458 return fn; 1459 } 1460 1461 /* 1462 * Get node with specified destination prefix (and source prefix, 1463 * if subtrees are used) 1464 * exact_match == true means we try to find fn with exact match of 1465 * the passed in prefix addr 1466 * exact_match == false means we try to find fn with longest prefix 1467 * match of the passed in prefix addr. This is useful for finding fn 1468 * for cached route as it will be stored in the exception table under 1469 * the node with longest prefix length. 1470 */ 1471 1472 1473 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1474 const struct in6_addr *addr, 1475 int plen, int offset, 1476 bool exact_match) 1477 { 1478 struct fib6_node *fn, *prev = NULL; 1479 1480 for (fn = root; fn ; ) { 1481 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1482 struct rt6key *key; 1483 1484 /* This node is being deleted */ 1485 if (!leaf) { 1486 if (plen <= fn->fn_bit) 1487 goto out; 1488 else 1489 goto next; 1490 } 1491 1492 key = (struct rt6key *)((u8 *)leaf + offset); 1493 1494 /* 1495 * Prefix match 1496 */ 1497 if (plen < fn->fn_bit || 1498 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1499 goto out; 1500 1501 if (plen == fn->fn_bit) 1502 return fn; 1503 1504 prev = fn; 1505 1506 next: 1507 /* 1508 * We have more bits to go 1509 */ 1510 if (addr_bit_set(addr, fn->fn_bit)) 1511 fn = rcu_dereference(fn->right); 1512 else 1513 fn = rcu_dereference(fn->left); 1514 } 1515 out: 1516 if (exact_match) 1517 return NULL; 1518 else 1519 return prev; 1520 } 1521 1522 struct fib6_node *fib6_locate(struct fib6_node *root, 1523 const struct in6_addr *daddr, int dst_len, 1524 const struct in6_addr *saddr, int src_len, 1525 bool exact_match) 1526 { 1527 struct fib6_node *fn; 1528 1529 fn = fib6_locate_1(root, daddr, dst_len, 1530 offsetof(struct fib6_info, fib6_dst), 1531 exact_match); 1532 1533 #ifdef CONFIG_IPV6_SUBTREES 1534 if (src_len) { 1535 WARN_ON(saddr == NULL); 1536 if (fn) { 1537 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1538 1539 if (subtree) { 1540 fn = fib6_locate_1(subtree, saddr, src_len, 1541 offsetof(struct fib6_info, fib6_src), 1542 exact_match); 1543 } 1544 } 1545 } 1546 #endif 1547 1548 if (fn && fn->fn_flags & RTN_RTINFO) 1549 return fn; 1550 1551 return NULL; 1552 } 1553 1554 1555 /* 1556 * Deletion 1557 * 1558 */ 1559 1560 static struct fib6_info *fib6_find_prefix(struct net *net, 1561 struct fib6_table *table, 1562 struct fib6_node *fn) 1563 { 1564 struct fib6_node *child_left, *child_right; 1565 1566 if (fn->fn_flags & RTN_ROOT) 1567 return net->ipv6.fib6_null_entry; 1568 1569 while (fn) { 1570 child_left = rcu_dereference_protected(fn->left, 1571 lockdep_is_held(&table->tb6_lock)); 1572 child_right = rcu_dereference_protected(fn->right, 1573 lockdep_is_held(&table->tb6_lock)); 1574 if (child_left) 1575 return rcu_dereference_protected(child_left->leaf, 1576 lockdep_is_held(&table->tb6_lock)); 1577 if (child_right) 1578 return rcu_dereference_protected(child_right->leaf, 1579 lockdep_is_held(&table->tb6_lock)); 1580 1581 fn = FIB6_SUBTREE(fn); 1582 } 1583 return NULL; 1584 } 1585 1586 /* 1587 * Called to trim the tree of intermediate nodes when possible. "fn" 1588 * is the node we want to try and remove. 1589 * Need to own table->tb6_lock 1590 */ 1591 1592 static struct fib6_node *fib6_repair_tree(struct net *net, 1593 struct fib6_table *table, 1594 struct fib6_node *fn) 1595 { 1596 int children; 1597 int nstate; 1598 struct fib6_node *child; 1599 struct fib6_walker *w; 1600 int iter = 0; 1601 1602 /* Set fn->leaf to null_entry for root node. */ 1603 if (fn->fn_flags & RTN_TL_ROOT) { 1604 rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry); 1605 return fn; 1606 } 1607 1608 for (;;) { 1609 struct fib6_node *fn_r = rcu_dereference_protected(fn->right, 1610 lockdep_is_held(&table->tb6_lock)); 1611 struct fib6_node *fn_l = rcu_dereference_protected(fn->left, 1612 lockdep_is_held(&table->tb6_lock)); 1613 struct fib6_node *pn = rcu_dereference_protected(fn->parent, 1614 lockdep_is_held(&table->tb6_lock)); 1615 struct fib6_node *pn_r = rcu_dereference_protected(pn->right, 1616 lockdep_is_held(&table->tb6_lock)); 1617 struct fib6_node *pn_l = rcu_dereference_protected(pn->left, 1618 lockdep_is_held(&table->tb6_lock)); 1619 struct fib6_info *fn_leaf = rcu_dereference_protected(fn->leaf, 1620 lockdep_is_held(&table->tb6_lock)); 1621 struct fib6_info *pn_leaf = rcu_dereference_protected(pn->leaf, 1622 lockdep_is_held(&table->tb6_lock)); 1623 struct fib6_info *new_fn_leaf; 1624 1625 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1626 iter++; 1627 1628 WARN_ON(fn->fn_flags & RTN_RTINFO); 1629 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1630 WARN_ON(fn_leaf); 1631 1632 children = 0; 1633 child = NULL; 1634 if (fn_r) 1635 child = fn_r, children |= 1; 1636 if (fn_l) 1637 child = fn_l, children |= 2; 1638 1639 if (children == 3 || FIB6_SUBTREE(fn) 1640 #ifdef CONFIG_IPV6_SUBTREES 1641 /* Subtree root (i.e. fn) may have one child */ 1642 || (children && fn->fn_flags & RTN_ROOT) 1643 #endif 1644 ) { 1645 new_fn_leaf = fib6_find_prefix(net, table, fn); 1646 #if RT6_DEBUG >= 2 1647 if (!new_fn_leaf) { 1648 WARN_ON(!new_fn_leaf); 1649 new_fn_leaf = net->ipv6.fib6_null_entry; 1650 } 1651 #endif 1652 fib6_info_hold(new_fn_leaf); 1653 rcu_assign_pointer(fn->leaf, new_fn_leaf); 1654 return pn; 1655 } 1656 1657 #ifdef CONFIG_IPV6_SUBTREES 1658 if (FIB6_SUBTREE(pn) == fn) { 1659 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1660 RCU_INIT_POINTER(pn->subtree, NULL); 1661 nstate = FWS_L; 1662 } else { 1663 WARN_ON(fn->fn_flags & RTN_ROOT); 1664 #endif 1665 if (pn_r == fn) 1666 rcu_assign_pointer(pn->right, child); 1667 else if (pn_l == fn) 1668 rcu_assign_pointer(pn->left, child); 1669 #if RT6_DEBUG >= 2 1670 else 1671 WARN_ON(1); 1672 #endif 1673 if (child) 1674 rcu_assign_pointer(child->parent, pn); 1675 nstate = FWS_R; 1676 #ifdef CONFIG_IPV6_SUBTREES 1677 } 1678 #endif 1679 1680 read_lock(&net->ipv6.fib6_walker_lock); 1681 FOR_WALKERS(net, w) { 1682 if (!child) { 1683 if (w->node == fn) { 1684 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1685 w->node = pn; 1686 w->state = nstate; 1687 } 1688 } else { 1689 if (w->node == fn) { 1690 w->node = child; 1691 if (children&2) { 1692 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1693 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1694 } else { 1695 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1696 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1697 } 1698 } 1699 } 1700 } 1701 read_unlock(&net->ipv6.fib6_walker_lock); 1702 1703 node_free(net, fn); 1704 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1705 return pn; 1706 1707 RCU_INIT_POINTER(pn->leaf, NULL); 1708 fib6_info_release(pn_leaf); 1709 fn = pn; 1710 } 1711 } 1712 1713 static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn, 1714 struct fib6_info __rcu **rtp, struct nl_info *info) 1715 { 1716 struct fib6_walker *w; 1717 struct fib6_info *rt = rcu_dereference_protected(*rtp, 1718 lockdep_is_held(&table->tb6_lock)); 1719 struct net *net = info->nl_net; 1720 1721 RT6_TRACE("fib6_del_route\n"); 1722 1723 /* Unlink it */ 1724 *rtp = rt->fib6_next; 1725 rt->fib6_node = NULL; 1726 net->ipv6.rt6_stats->fib_rt_entries--; 1727 net->ipv6.rt6_stats->fib_discarded_routes++; 1728 1729 /* Flush all cached dst in exception table */ 1730 rt6_flush_exceptions(rt); 1731 1732 /* Reset round-robin state, if necessary */ 1733 if (rcu_access_pointer(fn->rr_ptr) == rt) 1734 fn->rr_ptr = NULL; 1735 1736 /* Remove this entry from other siblings */ 1737 if (rt->fib6_nsiblings) { 1738 struct fib6_info *sibling, *next_sibling; 1739 1740 list_for_each_entry_safe(sibling, next_sibling, 1741 &rt->fib6_siblings, fib6_siblings) 1742 sibling->fib6_nsiblings--; 1743 rt->fib6_nsiblings = 0; 1744 list_del_init(&rt->fib6_siblings); 1745 rt6_multipath_rebalance(next_sibling); 1746 } 1747 1748 /* Adjust walkers */ 1749 read_lock(&net->ipv6.fib6_walker_lock); 1750 FOR_WALKERS(net, w) { 1751 if (w->state == FWS_C && w->leaf == rt) { 1752 RT6_TRACE("walker %p adjusted by delroute\n", w); 1753 w->leaf = rcu_dereference_protected(rt->fib6_next, 1754 lockdep_is_held(&table->tb6_lock)); 1755 if (!w->leaf) 1756 w->state = FWS_U; 1757 } 1758 } 1759 read_unlock(&net->ipv6.fib6_walker_lock); 1760 1761 /* If it was last route, call fib6_repair_tree() to: 1762 * 1. For root node, put back null_entry as how the table was created. 1763 * 2. For other nodes, expunge its radix tree node. 1764 */ 1765 if (!rcu_access_pointer(fn->leaf)) { 1766 if (!(fn->fn_flags & RTN_TL_ROOT)) { 1767 fn->fn_flags &= ~RTN_RTINFO; 1768 net->ipv6.rt6_stats->fib_route_nodes--; 1769 } 1770 fn = fib6_repair_tree(net, table, fn); 1771 } 1772 1773 fib6_purge_rt(rt, fn, net); 1774 1775 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL); 1776 if (!info->skip_notify) 1777 inet6_rt_notify(RTM_DELROUTE, rt, info, 0); 1778 fib6_info_release(rt); 1779 } 1780 1781 /* Need to own table->tb6_lock */ 1782 int fib6_del(struct fib6_info *rt, struct nl_info *info) 1783 { 1784 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1785 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1786 struct fib6_table *table = rt->fib6_table; 1787 struct net *net = info->nl_net; 1788 struct fib6_info __rcu **rtp; 1789 struct fib6_info __rcu **rtp_next; 1790 1791 if (!fn || rt == net->ipv6.fib6_null_entry) 1792 return -ENOENT; 1793 1794 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1795 1796 /* 1797 * Walk the leaf entries looking for ourself 1798 */ 1799 1800 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) { 1801 struct fib6_info *cur = rcu_dereference_protected(*rtp, 1802 lockdep_is_held(&table->tb6_lock)); 1803 if (rt == cur) { 1804 fib6_del_route(table, fn, rtp, info); 1805 return 0; 1806 } 1807 rtp_next = &cur->fib6_next; 1808 } 1809 return -ENOENT; 1810 } 1811 1812 /* 1813 * Tree traversal function. 1814 * 1815 * Certainly, it is not interrupt safe. 1816 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1817 * It means, that we can modify tree during walking 1818 * and use this function for garbage collection, clone pruning, 1819 * cleaning tree when a device goes down etc. etc. 1820 * 1821 * It guarantees that every node will be traversed, 1822 * and that it will be traversed only once. 1823 * 1824 * Callback function w->func may return: 1825 * 0 -> continue walking. 1826 * positive value -> walking is suspended (used by tree dumps, 1827 * and probably by gc, if it will be split to several slices) 1828 * negative value -> terminate walking. 1829 * 1830 * The function itself returns: 1831 * 0 -> walk is complete. 1832 * >0 -> walk is incomplete (i.e. suspended) 1833 * <0 -> walk is terminated by an error. 1834 * 1835 * This function is called with tb6_lock held. 1836 */ 1837 1838 static int fib6_walk_continue(struct fib6_walker *w) 1839 { 1840 struct fib6_node *fn, *pn, *left, *right; 1841 1842 /* w->root should always be table->tb6_root */ 1843 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT)); 1844 1845 for (;;) { 1846 fn = w->node; 1847 if (!fn) 1848 return 0; 1849 1850 switch (w->state) { 1851 #ifdef CONFIG_IPV6_SUBTREES 1852 case FWS_S: 1853 if (FIB6_SUBTREE(fn)) { 1854 w->node = FIB6_SUBTREE(fn); 1855 continue; 1856 } 1857 w->state = FWS_L; 1858 #endif 1859 /* fall through */ 1860 case FWS_L: 1861 left = rcu_dereference_protected(fn->left, 1); 1862 if (left) { 1863 w->node = left; 1864 w->state = FWS_INIT; 1865 continue; 1866 } 1867 w->state = FWS_R; 1868 /* fall through */ 1869 case FWS_R: 1870 right = rcu_dereference_protected(fn->right, 1); 1871 if (right) { 1872 w->node = right; 1873 w->state = FWS_INIT; 1874 continue; 1875 } 1876 w->state = FWS_C; 1877 w->leaf = rcu_dereference_protected(fn->leaf, 1); 1878 /* fall through */ 1879 case FWS_C: 1880 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1881 int err; 1882 1883 if (w->skip) { 1884 w->skip--; 1885 goto skip; 1886 } 1887 1888 err = w->func(w); 1889 if (err) 1890 return err; 1891 1892 w->count++; 1893 continue; 1894 } 1895 skip: 1896 w->state = FWS_U; 1897 /* fall through */ 1898 case FWS_U: 1899 if (fn == w->root) 1900 return 0; 1901 pn = rcu_dereference_protected(fn->parent, 1); 1902 left = rcu_dereference_protected(pn->left, 1); 1903 right = rcu_dereference_protected(pn->right, 1); 1904 w->node = pn; 1905 #ifdef CONFIG_IPV6_SUBTREES 1906 if (FIB6_SUBTREE(pn) == fn) { 1907 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1908 w->state = FWS_L; 1909 continue; 1910 } 1911 #endif 1912 if (left == fn) { 1913 w->state = FWS_R; 1914 continue; 1915 } 1916 if (right == fn) { 1917 w->state = FWS_C; 1918 w->leaf = rcu_dereference_protected(w->node->leaf, 1); 1919 continue; 1920 } 1921 #if RT6_DEBUG >= 2 1922 WARN_ON(1); 1923 #endif 1924 } 1925 } 1926 } 1927 1928 static int fib6_walk(struct net *net, struct fib6_walker *w) 1929 { 1930 int res; 1931 1932 w->state = FWS_INIT; 1933 w->node = w->root; 1934 1935 fib6_walker_link(net, w); 1936 res = fib6_walk_continue(w); 1937 if (res <= 0) 1938 fib6_walker_unlink(net, w); 1939 return res; 1940 } 1941 1942 static int fib6_clean_node(struct fib6_walker *w) 1943 { 1944 int res; 1945 struct fib6_info *rt; 1946 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 1947 struct nl_info info = { 1948 .nl_net = c->net, 1949 }; 1950 1951 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 1952 w->node->fn_sernum != c->sernum) 1953 w->node->fn_sernum = c->sernum; 1954 1955 if (!c->func) { 1956 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 1957 w->leaf = NULL; 1958 return 0; 1959 } 1960 1961 for_each_fib6_walker_rt(w) { 1962 res = c->func(rt, c->arg); 1963 if (res == -1) { 1964 w->leaf = rt; 1965 res = fib6_del(rt, &info); 1966 if (res) { 1967 #if RT6_DEBUG >= 2 1968 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 1969 __func__, rt, 1970 rcu_access_pointer(rt->fib6_node), 1971 res); 1972 #endif 1973 continue; 1974 } 1975 return 0; 1976 } else if (res == -2) { 1977 if (WARN_ON(!rt->fib6_nsiblings)) 1978 continue; 1979 rt = list_last_entry(&rt->fib6_siblings, 1980 struct fib6_info, fib6_siblings); 1981 continue; 1982 } 1983 WARN_ON(res != 0); 1984 } 1985 w->leaf = rt; 1986 return 0; 1987 } 1988 1989 /* 1990 * Convenient frontend to tree walker. 1991 * 1992 * func is called on each route. 1993 * It may return -2 -> skip multipath route. 1994 * -1 -> delete this route. 1995 * 0 -> continue walking 1996 */ 1997 1998 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 1999 int (*func)(struct fib6_info *, void *arg), 2000 int sernum, void *arg) 2001 { 2002 struct fib6_cleaner c; 2003 2004 c.w.root = root; 2005 c.w.func = fib6_clean_node; 2006 c.w.count = 0; 2007 c.w.skip = 0; 2008 c.func = func; 2009 c.sernum = sernum; 2010 c.arg = arg; 2011 c.net = net; 2012 2013 fib6_walk(net, &c.w); 2014 } 2015 2016 static void __fib6_clean_all(struct net *net, 2017 int (*func)(struct fib6_info *, void *), 2018 int sernum, void *arg) 2019 { 2020 struct fib6_table *table; 2021 struct hlist_head *head; 2022 unsigned int h; 2023 2024 rcu_read_lock(); 2025 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 2026 head = &net->ipv6.fib_table_hash[h]; 2027 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 2028 spin_lock_bh(&table->tb6_lock); 2029 fib6_clean_tree(net, &table->tb6_root, 2030 func, sernum, arg); 2031 spin_unlock_bh(&table->tb6_lock); 2032 } 2033 } 2034 rcu_read_unlock(); 2035 } 2036 2037 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *), 2038 void *arg) 2039 { 2040 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg); 2041 } 2042 2043 static void fib6_flush_trees(struct net *net) 2044 { 2045 int new_sernum = fib6_new_sernum(net); 2046 2047 __fib6_clean_all(net, NULL, new_sernum, NULL); 2048 } 2049 2050 /* 2051 * Garbage collection 2052 */ 2053 2054 static int fib6_age(struct fib6_info *rt, void *arg) 2055 { 2056 struct fib6_gc_args *gc_args = arg; 2057 unsigned long now = jiffies; 2058 2059 /* 2060 * check addrconf expiration here. 2061 * Routes are expired even if they are in use. 2062 */ 2063 2064 if (rt->fib6_flags & RTF_EXPIRES && rt->expires) { 2065 if (time_after(now, rt->expires)) { 2066 RT6_TRACE("expiring %p\n", rt); 2067 return -1; 2068 } 2069 gc_args->more++; 2070 } 2071 2072 /* Also age clones in the exception table. 2073 * Note, that clones are aged out 2074 * only if they are not in use now. 2075 */ 2076 rt6_age_exceptions(rt, gc_args, now); 2077 2078 return 0; 2079 } 2080 2081 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 2082 { 2083 struct fib6_gc_args gc_args; 2084 unsigned long now; 2085 2086 if (force) { 2087 spin_lock_bh(&net->ipv6.fib6_gc_lock); 2088 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) { 2089 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 2090 return; 2091 } 2092 gc_args.timeout = expires ? (int)expires : 2093 net->ipv6.sysctl.ip6_rt_gc_interval; 2094 gc_args.more = 0; 2095 2096 fib6_clean_all(net, fib6_age, &gc_args); 2097 now = jiffies; 2098 net->ipv6.ip6_rt_last_gc = now; 2099 2100 if (gc_args.more) 2101 mod_timer(&net->ipv6.ip6_fib_timer, 2102 round_jiffies(now 2103 + net->ipv6.sysctl.ip6_rt_gc_interval)); 2104 else 2105 del_timer(&net->ipv6.ip6_fib_timer); 2106 spin_unlock_bh(&net->ipv6.fib6_gc_lock); 2107 } 2108 2109 static void fib6_gc_timer_cb(struct timer_list *t) 2110 { 2111 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer); 2112 2113 fib6_run_gc(0, arg, true); 2114 } 2115 2116 static int __net_init fib6_net_init(struct net *net) 2117 { 2118 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 2119 int err; 2120 2121 err = fib6_notifier_init(net); 2122 if (err) 2123 return err; 2124 2125 spin_lock_init(&net->ipv6.fib6_gc_lock); 2126 rwlock_init(&net->ipv6.fib6_walker_lock); 2127 INIT_LIST_HEAD(&net->ipv6.fib6_walkers); 2128 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0); 2129 2130 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 2131 if (!net->ipv6.rt6_stats) 2132 goto out_timer; 2133 2134 /* Avoid false sharing : Use at least a full cache line */ 2135 size = max_t(size_t, size, L1_CACHE_BYTES); 2136 2137 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 2138 if (!net->ipv6.fib_table_hash) 2139 goto out_rt6_stats; 2140 2141 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 2142 GFP_KERNEL); 2143 if (!net->ipv6.fib6_main_tbl) 2144 goto out_fib_table_hash; 2145 2146 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 2147 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf, 2148 net->ipv6.fib6_null_entry); 2149 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 2150 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2151 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 2152 2153 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2154 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 2155 GFP_KERNEL); 2156 if (!net->ipv6.fib6_local_tbl) 2157 goto out_fib6_main_tbl; 2158 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 2159 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf, 2160 net->ipv6.fib6_null_entry); 2161 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 2162 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2163 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 2164 #endif 2165 fib6_tables_init(net); 2166 2167 return 0; 2168 2169 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2170 out_fib6_main_tbl: 2171 kfree(net->ipv6.fib6_main_tbl); 2172 #endif 2173 out_fib_table_hash: 2174 kfree(net->ipv6.fib_table_hash); 2175 out_rt6_stats: 2176 kfree(net->ipv6.rt6_stats); 2177 out_timer: 2178 fib6_notifier_exit(net); 2179 return -ENOMEM; 2180 } 2181 2182 static void fib6_net_exit(struct net *net) 2183 { 2184 unsigned int i; 2185 2186 del_timer_sync(&net->ipv6.ip6_fib_timer); 2187 2188 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) { 2189 struct hlist_head *head = &net->ipv6.fib_table_hash[i]; 2190 struct hlist_node *tmp; 2191 struct fib6_table *tb; 2192 2193 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) { 2194 hlist_del(&tb->tb6_hlist); 2195 fib6_free_table(tb); 2196 } 2197 } 2198 2199 kfree(net->ipv6.fib_table_hash); 2200 kfree(net->ipv6.rt6_stats); 2201 fib6_notifier_exit(net); 2202 } 2203 2204 static struct pernet_operations fib6_net_ops = { 2205 .init = fib6_net_init, 2206 .exit = fib6_net_exit, 2207 }; 2208 2209 int __init fib6_init(void) 2210 { 2211 int ret = -ENOMEM; 2212 2213 fib6_node_kmem = kmem_cache_create("fib6_nodes", 2214 sizeof(struct fib6_node), 2215 0, SLAB_HWCACHE_ALIGN, 2216 NULL); 2217 if (!fib6_node_kmem) 2218 goto out; 2219 2220 ret = register_pernet_subsys(&fib6_net_ops); 2221 if (ret) 2222 goto out_kmem_cache_create; 2223 2224 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL, 2225 inet6_dump_fib, 0); 2226 if (ret) 2227 goto out_unregister_subsys; 2228 2229 __fib6_flush_trees = fib6_flush_trees; 2230 out: 2231 return ret; 2232 2233 out_unregister_subsys: 2234 unregister_pernet_subsys(&fib6_net_ops); 2235 out_kmem_cache_create: 2236 kmem_cache_destroy(fib6_node_kmem); 2237 goto out; 2238 } 2239 2240 void fib6_gc_cleanup(void) 2241 { 2242 unregister_pernet_subsys(&fib6_net_ops); 2243 kmem_cache_destroy(fib6_node_kmem); 2244 } 2245 2246 #ifdef CONFIG_PROC_FS 2247 2248 struct ipv6_route_iter { 2249 struct seq_net_private p; 2250 struct fib6_walker w; 2251 loff_t skip; 2252 struct fib6_table *tbl; 2253 int sernum; 2254 }; 2255 2256 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 2257 { 2258 struct fib6_info *rt = v; 2259 struct ipv6_route_iter *iter = seq->private; 2260 const struct net_device *dev; 2261 2262 seq_printf(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen); 2263 2264 #ifdef CONFIG_IPV6_SUBTREES 2265 seq_printf(seq, "%pi6 %02x ", &rt->fib6_src.addr, rt->fib6_src.plen); 2266 #else 2267 seq_puts(seq, "00000000000000000000000000000000 00 "); 2268 #endif 2269 if (rt->fib6_flags & RTF_GATEWAY) 2270 seq_printf(seq, "%pi6", &rt->fib6_nh.nh_gw); 2271 else 2272 seq_puts(seq, "00000000000000000000000000000000"); 2273 2274 dev = rt->fib6_nh.nh_dev; 2275 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 2276 rt->fib6_metric, atomic_read(&rt->fib6_ref), 0, 2277 rt->fib6_flags, dev ? dev->name : ""); 2278 iter->w.leaf = NULL; 2279 return 0; 2280 } 2281 2282 static int ipv6_route_yield(struct fib6_walker *w) 2283 { 2284 struct ipv6_route_iter *iter = w->args; 2285 2286 if (!iter->skip) 2287 return 1; 2288 2289 do { 2290 iter->w.leaf = rcu_dereference_protected( 2291 iter->w.leaf->fib6_next, 2292 lockdep_is_held(&iter->tbl->tb6_lock)); 2293 iter->skip--; 2294 if (!iter->skip && iter->w.leaf) 2295 return 1; 2296 } while (iter->w.leaf); 2297 2298 return 0; 2299 } 2300 2301 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter, 2302 struct net *net) 2303 { 2304 memset(&iter->w, 0, sizeof(iter->w)); 2305 iter->w.func = ipv6_route_yield; 2306 iter->w.root = &iter->tbl->tb6_root; 2307 iter->w.state = FWS_INIT; 2308 iter->w.node = iter->w.root; 2309 iter->w.args = iter; 2310 iter->sernum = iter->w.root->fn_sernum; 2311 INIT_LIST_HEAD(&iter->w.lh); 2312 fib6_walker_link(net, &iter->w); 2313 } 2314 2315 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 2316 struct net *net) 2317 { 2318 unsigned int h; 2319 struct hlist_node *node; 2320 2321 if (tbl) { 2322 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 2323 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 2324 } else { 2325 h = 0; 2326 node = NULL; 2327 } 2328 2329 while (!node && h < FIB6_TABLE_HASHSZ) { 2330 node = rcu_dereference_bh( 2331 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 2332 } 2333 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 2334 } 2335 2336 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 2337 { 2338 if (iter->sernum != iter->w.root->fn_sernum) { 2339 iter->sernum = iter->w.root->fn_sernum; 2340 iter->w.state = FWS_INIT; 2341 iter->w.node = iter->w.root; 2342 WARN_ON(iter->w.skip); 2343 iter->w.skip = iter->w.count; 2344 } 2345 } 2346 2347 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2348 { 2349 int r; 2350 struct fib6_info *n; 2351 struct net *net = seq_file_net(seq); 2352 struct ipv6_route_iter *iter = seq->private; 2353 2354 if (!v) 2355 goto iter_table; 2356 2357 n = rcu_dereference_bh(((struct fib6_info *)v)->fib6_next); 2358 if (n) { 2359 ++*pos; 2360 return n; 2361 } 2362 2363 iter_table: 2364 ipv6_route_check_sernum(iter); 2365 spin_lock_bh(&iter->tbl->tb6_lock); 2366 r = fib6_walk_continue(&iter->w); 2367 spin_unlock_bh(&iter->tbl->tb6_lock); 2368 if (r > 0) { 2369 if (v) 2370 ++*pos; 2371 return iter->w.leaf; 2372 } else if (r < 0) { 2373 fib6_walker_unlink(net, &iter->w); 2374 return NULL; 2375 } 2376 fib6_walker_unlink(net, &iter->w); 2377 2378 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 2379 if (!iter->tbl) 2380 return NULL; 2381 2382 ipv6_route_seq_setup_walk(iter, net); 2383 goto iter_table; 2384 } 2385 2386 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 2387 __acquires(RCU_BH) 2388 { 2389 struct net *net = seq_file_net(seq); 2390 struct ipv6_route_iter *iter = seq->private; 2391 2392 rcu_read_lock_bh(); 2393 iter->tbl = ipv6_route_seq_next_table(NULL, net); 2394 iter->skip = *pos; 2395 2396 if (iter->tbl) { 2397 ipv6_route_seq_setup_walk(iter, net); 2398 return ipv6_route_seq_next(seq, NULL, pos); 2399 } else { 2400 return NULL; 2401 } 2402 } 2403 2404 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 2405 { 2406 struct fib6_walker *w = &iter->w; 2407 return w->node && !(w->state == FWS_U && w->node == w->root); 2408 } 2409 2410 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2411 __releases(RCU_BH) 2412 { 2413 struct net *net = seq_file_net(seq); 2414 struct ipv6_route_iter *iter = seq->private; 2415 2416 if (ipv6_route_iter_active(iter)) 2417 fib6_walker_unlink(net, &iter->w); 2418 2419 rcu_read_unlock_bh(); 2420 } 2421 2422 static const struct seq_operations ipv6_route_seq_ops = { 2423 .start = ipv6_route_seq_start, 2424 .next = ipv6_route_seq_next, 2425 .stop = ipv6_route_seq_stop, 2426 .show = ipv6_route_seq_show 2427 }; 2428 2429 int ipv6_route_open(struct inode *inode, struct file *file) 2430 { 2431 return seq_open_net(inode, file, &ipv6_route_seq_ops, 2432 sizeof(struct ipv6_route_iter)); 2433 } 2434 2435 #endif /* CONFIG_PROC_FS */ 2436