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_rcu(struct rcu_head *head) 171 { 172 struct fib6_info *f6i = container_of(head, struct fib6_info, rcu); 173 struct rt6_exception_bucket *bucket; 174 struct dst_metrics *m; 175 176 WARN_ON(f6i->fib6_node); 177 178 bucket = rcu_dereference_protected(f6i->rt6i_exception_bucket, 1); 179 if (bucket) { 180 f6i->rt6i_exception_bucket = NULL; 181 kfree(bucket); 182 } 183 184 if (f6i->rt6i_pcpu) { 185 int cpu; 186 187 for_each_possible_cpu(cpu) { 188 struct rt6_info **ppcpu_rt; 189 struct rt6_info *pcpu_rt; 190 191 ppcpu_rt = per_cpu_ptr(f6i->rt6i_pcpu, cpu); 192 pcpu_rt = *ppcpu_rt; 193 if (pcpu_rt) { 194 dst_dev_put(&pcpu_rt->dst); 195 dst_release(&pcpu_rt->dst); 196 *ppcpu_rt = NULL; 197 } 198 } 199 200 free_percpu(f6i->rt6i_pcpu); 201 } 202 203 lwtstate_put(f6i->fib6_nh.nh_lwtstate); 204 205 if (f6i->fib6_nh.nh_dev) 206 dev_put(f6i->fib6_nh.nh_dev); 207 208 m = f6i->fib6_metrics; 209 if (m != &dst_default_metrics && refcount_dec_and_test(&m->refcnt)) 210 kfree(m); 211 212 kfree(f6i); 213 } 214 EXPORT_SYMBOL_GPL(fib6_info_destroy_rcu); 215 216 static struct fib6_node *node_alloc(struct net *net) 217 { 218 struct fib6_node *fn; 219 220 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); 221 if (fn) 222 net->ipv6.rt6_stats->fib_nodes++; 223 224 return fn; 225 } 226 227 static void node_free_immediate(struct net *net, struct fib6_node *fn) 228 { 229 kmem_cache_free(fib6_node_kmem, fn); 230 net->ipv6.rt6_stats->fib_nodes--; 231 } 232 233 static void node_free_rcu(struct rcu_head *head) 234 { 235 struct fib6_node *fn = container_of(head, struct fib6_node, rcu); 236 237 kmem_cache_free(fib6_node_kmem, fn); 238 } 239 240 static void node_free(struct net *net, struct fib6_node *fn) 241 { 242 call_rcu(&fn->rcu, node_free_rcu); 243 net->ipv6.rt6_stats->fib_nodes--; 244 } 245 246 static void fib6_free_table(struct fib6_table *table) 247 { 248 inetpeer_invalidate_tree(&table->tb6_peers); 249 kfree(table); 250 } 251 252 static void fib6_link_table(struct net *net, struct fib6_table *tb) 253 { 254 unsigned int h; 255 256 /* 257 * Initialize table lock at a single place to give lockdep a key, 258 * tables aren't visible prior to being linked to the list. 259 */ 260 spin_lock_init(&tb->tb6_lock); 261 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 262 263 /* 264 * No protection necessary, this is the only list mutatation 265 * operation, tables never disappear once they exist. 266 */ 267 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 268 } 269 270 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 271 272 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 273 { 274 struct fib6_table *table; 275 276 table = kzalloc(sizeof(*table), GFP_ATOMIC); 277 if (table) { 278 table->tb6_id = id; 279 rcu_assign_pointer(table->tb6_root.leaf, 280 net->ipv6.fib6_null_entry); 281 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 282 inet_peer_base_init(&table->tb6_peers); 283 } 284 285 return table; 286 } 287 288 struct fib6_table *fib6_new_table(struct net *net, u32 id) 289 { 290 struct fib6_table *tb; 291 292 if (id == 0) 293 id = RT6_TABLE_MAIN; 294 tb = fib6_get_table(net, id); 295 if (tb) 296 return tb; 297 298 tb = fib6_alloc_table(net, id); 299 if (tb) 300 fib6_link_table(net, tb); 301 302 return tb; 303 } 304 EXPORT_SYMBOL_GPL(fib6_new_table); 305 306 struct fib6_table *fib6_get_table(struct net *net, u32 id) 307 { 308 struct fib6_table *tb; 309 struct hlist_head *head; 310 unsigned int h; 311 312 if (id == 0) 313 id = RT6_TABLE_MAIN; 314 h = id & (FIB6_TABLE_HASHSZ - 1); 315 rcu_read_lock(); 316 head = &net->ipv6.fib_table_hash[h]; 317 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 318 if (tb->tb6_id == id) { 319 rcu_read_unlock(); 320 return tb; 321 } 322 } 323 rcu_read_unlock(); 324 325 return NULL; 326 } 327 EXPORT_SYMBOL_GPL(fib6_get_table); 328 329 static void __net_init fib6_tables_init(struct net *net) 330 { 331 fib6_link_table(net, net->ipv6.fib6_main_tbl); 332 fib6_link_table(net, net->ipv6.fib6_local_tbl); 333 } 334 #else 335 336 struct fib6_table *fib6_new_table(struct net *net, u32 id) 337 { 338 return fib6_get_table(net, id); 339 } 340 341 struct fib6_table *fib6_get_table(struct net *net, u32 id) 342 { 343 return net->ipv6.fib6_main_tbl; 344 } 345 346 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 347 const struct sk_buff *skb, 348 int flags, pol_lookup_t lookup) 349 { 350 struct rt6_info *rt; 351 352 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags); 353 if (rt->dst.error == -EAGAIN) { 354 ip6_rt_put(rt); 355 rt = net->ipv6.ip6_null_entry; 356 dst_hold(&rt->dst); 357 } 358 359 return &rt->dst; 360 } 361 362 /* called with rcu lock held; no reference taken on fib6_info */ 363 struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 364 int flags) 365 { 366 return fib6_table_lookup(net, net->ipv6.fib6_main_tbl, oif, fl6, flags); 367 } 368 369 static void __net_init fib6_tables_init(struct net *net) 370 { 371 fib6_link_table(net, net->ipv6.fib6_main_tbl); 372 } 373 374 #endif 375 376 unsigned int fib6_tables_seq_read(struct net *net) 377 { 378 unsigned int h, fib_seq = 0; 379 380 rcu_read_lock(); 381 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 382 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 383 struct fib6_table *tb; 384 385 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 386 fib_seq += tb->fib_seq; 387 } 388 rcu_read_unlock(); 389 390 return fib_seq; 391 } 392 393 static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net, 394 enum fib_event_type event_type, 395 struct fib6_info *rt) 396 { 397 struct fib6_entry_notifier_info info = { 398 .rt = rt, 399 }; 400 401 return call_fib6_notifier(nb, net, event_type, &info.info); 402 } 403 404 static int call_fib6_entry_notifiers(struct net *net, 405 enum fib_event_type event_type, 406 struct fib6_info *rt, 407 struct netlink_ext_ack *extack) 408 { 409 struct fib6_entry_notifier_info info = { 410 .info.extack = extack, 411 .rt = rt, 412 }; 413 414 rt->fib6_table->fib_seq++; 415 return call_fib6_notifiers(net, event_type, &info.info); 416 } 417 418 struct fib6_dump_arg { 419 struct net *net; 420 struct notifier_block *nb; 421 }; 422 423 static void fib6_rt_dump(struct fib6_info *rt, struct fib6_dump_arg *arg) 424 { 425 if (rt == arg->net->ipv6.fib6_null_entry) 426 return; 427 call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt); 428 } 429 430 static int fib6_node_dump(struct fib6_walker *w) 431 { 432 struct fib6_info *rt; 433 434 for_each_fib6_walker_rt(w) 435 fib6_rt_dump(rt, w->args); 436 w->leaf = NULL; 437 return 0; 438 } 439 440 static void fib6_table_dump(struct net *net, struct fib6_table *tb, 441 struct fib6_walker *w) 442 { 443 w->root = &tb->tb6_root; 444 spin_lock_bh(&tb->tb6_lock); 445 fib6_walk(net, w); 446 spin_unlock_bh(&tb->tb6_lock); 447 } 448 449 /* Called with rcu_read_lock() */ 450 int fib6_tables_dump(struct net *net, struct notifier_block *nb) 451 { 452 struct fib6_dump_arg arg; 453 struct fib6_walker *w; 454 unsigned int h; 455 456 w = kzalloc(sizeof(*w), GFP_ATOMIC); 457 if (!w) 458 return -ENOMEM; 459 460 w->func = fib6_node_dump; 461 arg.net = net; 462 arg.nb = nb; 463 w->args = &arg; 464 465 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 466 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 467 struct fib6_table *tb; 468 469 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 470 fib6_table_dump(net, tb, w); 471 } 472 473 kfree(w); 474 475 return 0; 476 } 477 478 static int fib6_dump_node(struct fib6_walker *w) 479 { 480 int res; 481 struct fib6_info *rt; 482 483 for_each_fib6_walker_rt(w) { 484 res = rt6_dump_route(rt, w->args); 485 if (res < 0) { 486 /* Frame is full, suspend walking */ 487 w->leaf = rt; 488 return 1; 489 } 490 491 /* Multipath routes are dumped in one route with the 492 * RTA_MULTIPATH attribute. Jump 'rt' to point to the 493 * last sibling of this route (no need to dump the 494 * sibling routes again) 495 */ 496 if (rt->fib6_nsiblings) 497 rt = list_last_entry(&rt->fib6_siblings, 498 struct fib6_info, 499 fib6_siblings); 500 } 501 w->leaf = NULL; 502 return 0; 503 } 504 505 static void fib6_dump_end(struct netlink_callback *cb) 506 { 507 struct net *net = sock_net(cb->skb->sk); 508 struct fib6_walker *w = (void *)cb->args[2]; 509 510 if (w) { 511 if (cb->args[4]) { 512 cb->args[4] = 0; 513 fib6_walker_unlink(net, w); 514 } 515 cb->args[2] = 0; 516 kfree(w); 517 } 518 cb->done = (void *)cb->args[3]; 519 cb->args[1] = 3; 520 } 521 522 static int fib6_dump_done(struct netlink_callback *cb) 523 { 524 fib6_dump_end(cb); 525 return cb->done ? cb->done(cb) : 0; 526 } 527 528 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 529 struct netlink_callback *cb) 530 { 531 struct net *net = sock_net(skb->sk); 532 struct fib6_walker *w; 533 int res; 534 535 w = (void *)cb->args[2]; 536 w->root = &table->tb6_root; 537 538 if (cb->args[4] == 0) { 539 w->count = 0; 540 w->skip = 0; 541 542 spin_lock_bh(&table->tb6_lock); 543 res = fib6_walk(net, w); 544 spin_unlock_bh(&table->tb6_lock); 545 if (res > 0) { 546 cb->args[4] = 1; 547 cb->args[5] = w->root->fn_sernum; 548 } 549 } else { 550 if (cb->args[5] != w->root->fn_sernum) { 551 /* Begin at the root if the tree changed */ 552 cb->args[5] = w->root->fn_sernum; 553 w->state = FWS_INIT; 554 w->node = w->root; 555 w->skip = w->count; 556 } else 557 w->skip = 0; 558 559 spin_lock_bh(&table->tb6_lock); 560 res = fib6_walk_continue(w); 561 spin_unlock_bh(&table->tb6_lock); 562 if (res <= 0) { 563 fib6_walker_unlink(net, w); 564 cb->args[4] = 0; 565 } 566 } 567 568 return res; 569 } 570 571 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 572 { 573 struct net *net = sock_net(skb->sk); 574 unsigned int h, s_h; 575 unsigned int e = 0, s_e; 576 struct rt6_rtnl_dump_arg arg; 577 struct fib6_walker *w; 578 struct fib6_table *tb; 579 struct hlist_head *head; 580 int res = 0; 581 582 s_h = cb->args[0]; 583 s_e = cb->args[1]; 584 585 w = (void *)cb->args[2]; 586 if (!w) { 587 /* New dump: 588 * 589 * 1. hook callback destructor. 590 */ 591 cb->args[3] = (long)cb->done; 592 cb->done = fib6_dump_done; 593 594 /* 595 * 2. allocate and initialize walker. 596 */ 597 w = kzalloc(sizeof(*w), GFP_ATOMIC); 598 if (!w) 599 return -ENOMEM; 600 w->func = fib6_dump_node; 601 cb->args[2] = (long)w; 602 } 603 604 arg.skb = skb; 605 arg.cb = cb; 606 arg.net = net; 607 w->args = &arg; 608 609 rcu_read_lock(); 610 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 611 e = 0; 612 head = &net->ipv6.fib_table_hash[h]; 613 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 614 if (e < s_e) 615 goto next; 616 res = fib6_dump_table(tb, skb, cb); 617 if (res != 0) 618 goto out; 619 next: 620 e++; 621 } 622 } 623 out: 624 rcu_read_unlock(); 625 cb->args[1] = e; 626 cb->args[0] = h; 627 628 res = res < 0 ? res : skb->len; 629 if (res <= 0) 630 fib6_dump_end(cb); 631 return res; 632 } 633 634 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val) 635 { 636 if (!f6i) 637 return; 638 639 if (f6i->fib6_metrics == &dst_default_metrics) { 640 struct dst_metrics *p = kzalloc(sizeof(*p), GFP_ATOMIC); 641 642 if (!p) 643 return; 644 645 refcount_set(&p->refcnt, 1); 646 f6i->fib6_metrics = p; 647 } 648 649 f6i->fib6_metrics->metrics[metric - 1] = val; 650 } 651 652 /* 653 * Routing Table 654 * 655 * return the appropriate node for a routing tree "add" operation 656 * by either creating and inserting or by returning an existing 657 * node. 658 */ 659 660 static struct fib6_node *fib6_add_1(struct net *net, 661 struct fib6_table *table, 662 struct fib6_node *root, 663 struct in6_addr *addr, int plen, 664 int offset, int allow_create, 665 int replace_required, 666 struct netlink_ext_ack *extack) 667 { 668 struct fib6_node *fn, *in, *ln; 669 struct fib6_node *pn = NULL; 670 struct rt6key *key; 671 int bit; 672 __be32 dir = 0; 673 674 RT6_TRACE("fib6_add_1\n"); 675 676 /* insert node in tree */ 677 678 fn = root; 679 680 do { 681 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 682 lockdep_is_held(&table->tb6_lock)); 683 key = (struct rt6key *)((u8 *)leaf + offset); 684 685 /* 686 * Prefix match 687 */ 688 if (plen < fn->fn_bit || 689 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 690 if (!allow_create) { 691 if (replace_required) { 692 NL_SET_ERR_MSG(extack, 693 "Can not replace route - no match found"); 694 pr_warn("Can't replace route, no match found\n"); 695 return ERR_PTR(-ENOENT); 696 } 697 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 698 } 699 goto insert_above; 700 } 701 702 /* 703 * Exact match ? 704 */ 705 706 if (plen == fn->fn_bit) { 707 /* clean up an intermediate node */ 708 if (!(fn->fn_flags & RTN_RTINFO)) { 709 RCU_INIT_POINTER(fn->leaf, NULL); 710 fib6_info_release(leaf); 711 /* remove null_entry in the root node */ 712 } else if (fn->fn_flags & RTN_TL_ROOT && 713 rcu_access_pointer(fn->leaf) == 714 net->ipv6.fib6_null_entry) { 715 RCU_INIT_POINTER(fn->leaf, NULL); 716 } 717 718 return fn; 719 } 720 721 /* 722 * We have more bits to go 723 */ 724 725 /* Try to walk down on tree. */ 726 dir = addr_bit_set(addr, fn->fn_bit); 727 pn = fn; 728 fn = dir ? 729 rcu_dereference_protected(fn->right, 730 lockdep_is_held(&table->tb6_lock)) : 731 rcu_dereference_protected(fn->left, 732 lockdep_is_held(&table->tb6_lock)); 733 } while (fn); 734 735 if (!allow_create) { 736 /* We should not create new node because 737 * NLM_F_REPLACE was specified without NLM_F_CREATE 738 * I assume it is safe to require NLM_F_CREATE when 739 * REPLACE flag is used! Later we may want to remove the 740 * check for replace_required, because according 741 * to netlink specification, NLM_F_CREATE 742 * MUST be specified if new route is created. 743 * That would keep IPv6 consistent with IPv4 744 */ 745 if (replace_required) { 746 NL_SET_ERR_MSG(extack, 747 "Can not replace route - no match found"); 748 pr_warn("Can't replace route, no match found\n"); 749 return ERR_PTR(-ENOENT); 750 } 751 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 752 } 753 /* 754 * We walked to the bottom of tree. 755 * Create new leaf node without children. 756 */ 757 758 ln = node_alloc(net); 759 760 if (!ln) 761 return ERR_PTR(-ENOMEM); 762 ln->fn_bit = plen; 763 RCU_INIT_POINTER(ln->parent, pn); 764 765 if (dir) 766 rcu_assign_pointer(pn->right, ln); 767 else 768 rcu_assign_pointer(pn->left, ln); 769 770 return ln; 771 772 773 insert_above: 774 /* 775 * split since we don't have a common prefix anymore or 776 * we have a less significant route. 777 * we've to insert an intermediate node on the list 778 * this new node will point to the one we need to create 779 * and the current 780 */ 781 782 pn = rcu_dereference_protected(fn->parent, 783 lockdep_is_held(&table->tb6_lock)); 784 785 /* find 1st bit in difference between the 2 addrs. 786 787 See comment in __ipv6_addr_diff: bit may be an invalid value, 788 but if it is >= plen, the value is ignored in any case. 789 */ 790 791 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 792 793 /* 794 * (intermediate)[in] 795 * / \ 796 * (new leaf node)[ln] (old node)[fn] 797 */ 798 if (plen > bit) { 799 in = node_alloc(net); 800 ln = node_alloc(net); 801 802 if (!in || !ln) { 803 if (in) 804 node_free_immediate(net, in); 805 if (ln) 806 node_free_immediate(net, ln); 807 return ERR_PTR(-ENOMEM); 808 } 809 810 /* 811 * new intermediate node. 812 * RTN_RTINFO will 813 * be off since that an address that chooses one of 814 * the branches would not match less specific routes 815 * in the other branch 816 */ 817 818 in->fn_bit = bit; 819 820 RCU_INIT_POINTER(in->parent, pn); 821 in->leaf = fn->leaf; 822 atomic_inc(&rcu_dereference_protected(in->leaf, 823 lockdep_is_held(&table->tb6_lock))->fib6_ref); 824 825 /* update parent pointer */ 826 if (dir) 827 rcu_assign_pointer(pn->right, in); 828 else 829 rcu_assign_pointer(pn->left, in); 830 831 ln->fn_bit = plen; 832 833 RCU_INIT_POINTER(ln->parent, in); 834 rcu_assign_pointer(fn->parent, in); 835 836 if (addr_bit_set(addr, bit)) { 837 rcu_assign_pointer(in->right, ln); 838 rcu_assign_pointer(in->left, fn); 839 } else { 840 rcu_assign_pointer(in->left, ln); 841 rcu_assign_pointer(in->right, fn); 842 } 843 } else { /* plen <= bit */ 844 845 /* 846 * (new leaf node)[ln] 847 * / \ 848 * (old node)[fn] NULL 849 */ 850 851 ln = node_alloc(net); 852 853 if (!ln) 854 return ERR_PTR(-ENOMEM); 855 856 ln->fn_bit = plen; 857 858 RCU_INIT_POINTER(ln->parent, pn); 859 860 if (addr_bit_set(&key->addr, plen)) 861 RCU_INIT_POINTER(ln->right, fn); 862 else 863 RCU_INIT_POINTER(ln->left, fn); 864 865 rcu_assign_pointer(fn->parent, ln); 866 867 if (dir) 868 rcu_assign_pointer(pn->right, ln); 869 else 870 rcu_assign_pointer(pn->left, ln); 871 } 872 return ln; 873 } 874 875 static void fib6_drop_pcpu_from(struct fib6_info *f6i, 876 const struct fib6_table *table) 877 { 878 int cpu; 879 880 /* release the reference to this fib entry from 881 * all of its cached pcpu routes 882 */ 883 for_each_possible_cpu(cpu) { 884 struct rt6_info **ppcpu_rt; 885 struct rt6_info *pcpu_rt; 886 887 ppcpu_rt = per_cpu_ptr(f6i->rt6i_pcpu, cpu); 888 pcpu_rt = *ppcpu_rt; 889 if (pcpu_rt) { 890 struct fib6_info *from; 891 892 from = rcu_dereference_protected(pcpu_rt->from, 893 lockdep_is_held(&table->tb6_lock)); 894 rcu_assign_pointer(pcpu_rt->from, NULL); 895 fib6_info_release(from); 896 } 897 } 898 } 899 900 static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn, 901 struct net *net) 902 { 903 struct fib6_table *table = rt->fib6_table; 904 905 if (atomic_read(&rt->fib6_ref) != 1) { 906 /* This route is used as dummy address holder in some split 907 * nodes. It is not leaked, but it still holds other resources, 908 * which must be released in time. So, scan ascendant nodes 909 * and replace dummy references to this route with references 910 * to still alive ones. 911 */ 912 while (fn) { 913 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 914 lockdep_is_held(&table->tb6_lock)); 915 struct fib6_info *new_leaf; 916 if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) { 917 new_leaf = fib6_find_prefix(net, table, fn); 918 atomic_inc(&new_leaf->fib6_ref); 919 920 rcu_assign_pointer(fn->leaf, new_leaf); 921 fib6_info_release(rt); 922 } 923 fn = rcu_dereference_protected(fn->parent, 924 lockdep_is_held(&table->tb6_lock)); 925 } 926 927 if (rt->rt6i_pcpu) 928 fib6_drop_pcpu_from(rt, table); 929 } 930 } 931 932 /* 933 * Insert routing information in a node. 934 */ 935 936 static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt, 937 struct nl_info *info, 938 struct netlink_ext_ack *extack) 939 { 940 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 941 lockdep_is_held(&rt->fib6_table->tb6_lock)); 942 struct fib6_info *iter = NULL; 943 struct fib6_info __rcu **ins; 944 struct fib6_info __rcu **fallback_ins = NULL; 945 int replace = (info->nlh && 946 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 947 int add = (!info->nlh || 948 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 949 int found = 0; 950 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 951 u16 nlflags = NLM_F_EXCL; 952 int err; 953 954 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND)) 955 nlflags |= NLM_F_APPEND; 956 957 ins = &fn->leaf; 958 959 for (iter = leaf; iter; 960 iter = rcu_dereference_protected(iter->fib6_next, 961 lockdep_is_held(&rt->fib6_table->tb6_lock))) { 962 /* 963 * Search for duplicates 964 */ 965 966 if (iter->fib6_metric == rt->fib6_metric) { 967 /* 968 * Same priority level 969 */ 970 if (info->nlh && 971 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 972 return -EEXIST; 973 974 nlflags &= ~NLM_F_EXCL; 975 if (replace) { 976 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) { 977 found++; 978 break; 979 } 980 if (rt_can_ecmp) 981 fallback_ins = fallback_ins ?: ins; 982 goto next_iter; 983 } 984 985 if (rt6_duplicate_nexthop(iter, rt)) { 986 if (rt->fib6_nsiblings) 987 rt->fib6_nsiblings = 0; 988 if (!(iter->fib6_flags & RTF_EXPIRES)) 989 return -EEXIST; 990 if (!(rt->fib6_flags & RTF_EXPIRES)) 991 fib6_clean_expires(iter); 992 else 993 fib6_set_expires(iter, rt->expires); 994 995 if (rt->fib6_pmtu) 996 fib6_metric_set(iter, RTAX_MTU, 997 rt->fib6_pmtu); 998 return -EEXIST; 999 } 1000 /* If we have the same destination and the same metric, 1001 * but not the same gateway, then the route we try to 1002 * add is sibling to this route, increment our counter 1003 * of siblings, and later we will add our route to the 1004 * list. 1005 * Only static routes (which don't have flag 1006 * RTF_EXPIRES) are used for ECMPv6. 1007 * 1008 * To avoid long list, we only had siblings if the 1009 * route have a gateway. 1010 */ 1011 if (rt_can_ecmp && 1012 rt6_qualify_for_ecmp(iter)) 1013 rt->fib6_nsiblings++; 1014 } 1015 1016 if (iter->fib6_metric > rt->fib6_metric) 1017 break; 1018 1019 next_iter: 1020 ins = &iter->fib6_next; 1021 } 1022 1023 if (fallback_ins && !found) { 1024 /* No ECMP-able route found, replace first non-ECMP one */ 1025 ins = fallback_ins; 1026 iter = rcu_dereference_protected(*ins, 1027 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1028 found++; 1029 } 1030 1031 /* Reset round-robin state, if necessary */ 1032 if (ins == &fn->leaf) 1033 fn->rr_ptr = NULL; 1034 1035 /* Link this route to others same route. */ 1036 if (rt->fib6_nsiblings) { 1037 unsigned int fib6_nsiblings; 1038 struct fib6_info *sibling, *temp_sibling; 1039 1040 /* Find the first route that have the same metric */ 1041 sibling = leaf; 1042 while (sibling) { 1043 if (sibling->fib6_metric == rt->fib6_metric && 1044 rt6_qualify_for_ecmp(sibling)) { 1045 list_add_tail(&rt->fib6_siblings, 1046 &sibling->fib6_siblings); 1047 break; 1048 } 1049 sibling = rcu_dereference_protected(sibling->fib6_next, 1050 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1051 } 1052 /* For each sibling in the list, increment the counter of 1053 * siblings. BUG() if counters does not match, list of siblings 1054 * is broken! 1055 */ 1056 fib6_nsiblings = 0; 1057 list_for_each_entry_safe(sibling, temp_sibling, 1058 &rt->fib6_siblings, fib6_siblings) { 1059 sibling->fib6_nsiblings++; 1060 BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings); 1061 fib6_nsiblings++; 1062 } 1063 BUG_ON(fib6_nsiblings != rt->fib6_nsiblings); 1064 rt6_multipath_rebalance(temp_sibling); 1065 } 1066 1067 /* 1068 * insert node 1069 */ 1070 if (!replace) { 1071 if (!add) 1072 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 1073 1074 add: 1075 nlflags |= NLM_F_CREATE; 1076 1077 err = call_fib6_entry_notifiers(info->nl_net, 1078 FIB_EVENT_ENTRY_ADD, 1079 rt, extack); 1080 if (err) 1081 return err; 1082 1083 rcu_assign_pointer(rt->fib6_next, iter); 1084 atomic_inc(&rt->fib6_ref); 1085 rcu_assign_pointer(rt->fib6_node, fn); 1086 rcu_assign_pointer(*ins, rt); 1087 if (!info->skip_notify) 1088 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); 1089 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 1090 1091 if (!(fn->fn_flags & RTN_RTINFO)) { 1092 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1093 fn->fn_flags |= RTN_RTINFO; 1094 } 1095 1096 } else { 1097 int nsiblings; 1098 1099 if (!found) { 1100 if (add) 1101 goto add; 1102 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 1103 return -ENOENT; 1104 } 1105 1106 err = call_fib6_entry_notifiers(info->nl_net, 1107 FIB_EVENT_ENTRY_REPLACE, 1108 rt, extack); 1109 if (err) 1110 return err; 1111 1112 atomic_inc(&rt->fib6_ref); 1113 rcu_assign_pointer(rt->fib6_node, fn); 1114 rt->fib6_next = iter->fib6_next; 1115 rcu_assign_pointer(*ins, rt); 1116 if (!info->skip_notify) 1117 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); 1118 if (!(fn->fn_flags & RTN_RTINFO)) { 1119 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1120 fn->fn_flags |= RTN_RTINFO; 1121 } 1122 nsiblings = iter->fib6_nsiblings; 1123 iter->fib6_node = NULL; 1124 fib6_purge_rt(iter, fn, info->nl_net); 1125 if (rcu_access_pointer(fn->rr_ptr) == iter) 1126 fn->rr_ptr = NULL; 1127 fib6_info_release(iter); 1128 1129 if (nsiblings) { 1130 /* Replacing an ECMP route, remove all siblings */ 1131 ins = &rt->fib6_next; 1132 iter = rcu_dereference_protected(*ins, 1133 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1134 while (iter) { 1135 if (iter->fib6_metric > rt->fib6_metric) 1136 break; 1137 if (rt6_qualify_for_ecmp(iter)) { 1138 *ins = iter->fib6_next; 1139 iter->fib6_node = NULL; 1140 fib6_purge_rt(iter, fn, info->nl_net); 1141 if (rcu_access_pointer(fn->rr_ptr) == iter) 1142 fn->rr_ptr = NULL; 1143 fib6_info_release(iter); 1144 nsiblings--; 1145 info->nl_net->ipv6.rt6_stats->fib_rt_entries--; 1146 } else { 1147 ins = &iter->fib6_next; 1148 } 1149 iter = rcu_dereference_protected(*ins, 1150 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1151 } 1152 WARN_ON(nsiblings != 0); 1153 } 1154 } 1155 1156 return 0; 1157 } 1158 1159 static void fib6_start_gc(struct net *net, struct fib6_info *rt) 1160 { 1161 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 1162 (rt->fib6_flags & RTF_EXPIRES)) 1163 mod_timer(&net->ipv6.ip6_fib_timer, 1164 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1165 } 1166 1167 void fib6_force_start_gc(struct net *net) 1168 { 1169 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 1170 mod_timer(&net->ipv6.ip6_fib_timer, 1171 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1172 } 1173 1174 static void __fib6_update_sernum_upto_root(struct fib6_info *rt, 1175 int sernum) 1176 { 1177 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1178 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1179 1180 /* paired with smp_rmb() in rt6_get_cookie_safe() */ 1181 smp_wmb(); 1182 while (fn) { 1183 fn->fn_sernum = sernum; 1184 fn = rcu_dereference_protected(fn->parent, 1185 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1186 } 1187 } 1188 1189 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt) 1190 { 1191 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net)); 1192 } 1193 1194 /* 1195 * Add routing information to the routing tree. 1196 * <destination addr>/<source addr> 1197 * with source addr info in sub-trees 1198 * Need to own table->tb6_lock 1199 */ 1200 1201 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 1202 struct nl_info *info, struct netlink_ext_ack *extack) 1203 { 1204 struct fib6_table *table = rt->fib6_table; 1205 struct fib6_node *fn, *pn = NULL; 1206 int err = -ENOMEM; 1207 int allow_create = 1; 1208 int replace_required = 0; 1209 int sernum = fib6_new_sernum(info->nl_net); 1210 1211 if (info->nlh) { 1212 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 1213 allow_create = 0; 1214 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 1215 replace_required = 1; 1216 } 1217 if (!allow_create && !replace_required) 1218 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 1219 1220 fn = fib6_add_1(info->nl_net, table, root, 1221 &rt->fib6_dst.addr, rt->fib6_dst.plen, 1222 offsetof(struct fib6_info, fib6_dst), allow_create, 1223 replace_required, extack); 1224 if (IS_ERR(fn)) { 1225 err = PTR_ERR(fn); 1226 fn = NULL; 1227 goto out; 1228 } 1229 1230 pn = fn; 1231 1232 #ifdef CONFIG_IPV6_SUBTREES 1233 if (rt->fib6_src.plen) { 1234 struct fib6_node *sn; 1235 1236 if (!rcu_access_pointer(fn->subtree)) { 1237 struct fib6_node *sfn; 1238 1239 /* 1240 * Create subtree. 1241 * 1242 * fn[main tree] 1243 * | 1244 * sfn[subtree root] 1245 * \ 1246 * sn[new leaf node] 1247 */ 1248 1249 /* Create subtree root node */ 1250 sfn = node_alloc(info->nl_net); 1251 if (!sfn) 1252 goto failure; 1253 1254 atomic_inc(&info->nl_net->ipv6.fib6_null_entry->fib6_ref); 1255 rcu_assign_pointer(sfn->leaf, 1256 info->nl_net->ipv6.fib6_null_entry); 1257 sfn->fn_flags = RTN_ROOT; 1258 1259 /* Now add the first leaf node to new subtree */ 1260 1261 sn = fib6_add_1(info->nl_net, table, sfn, 1262 &rt->fib6_src.addr, rt->fib6_src.plen, 1263 offsetof(struct fib6_info, fib6_src), 1264 allow_create, replace_required, extack); 1265 1266 if (IS_ERR(sn)) { 1267 /* If it is failed, discard just allocated 1268 root, and then (in failure) stale node 1269 in main tree. 1270 */ 1271 node_free_immediate(info->nl_net, sfn); 1272 err = PTR_ERR(sn); 1273 goto failure; 1274 } 1275 1276 /* Now link new subtree to main tree */ 1277 rcu_assign_pointer(sfn->parent, fn); 1278 rcu_assign_pointer(fn->subtree, sfn); 1279 } else { 1280 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn), 1281 &rt->fib6_src.addr, rt->fib6_src.plen, 1282 offsetof(struct fib6_info, fib6_src), 1283 allow_create, replace_required, extack); 1284 1285 if (IS_ERR(sn)) { 1286 err = PTR_ERR(sn); 1287 goto failure; 1288 } 1289 } 1290 1291 if (!rcu_access_pointer(fn->leaf)) { 1292 if (fn->fn_flags & RTN_TL_ROOT) { 1293 /* put back null_entry for root node */ 1294 rcu_assign_pointer(fn->leaf, 1295 info->nl_net->ipv6.fib6_null_entry); 1296 } else { 1297 atomic_inc(&rt->fib6_ref); 1298 rcu_assign_pointer(fn->leaf, rt); 1299 } 1300 } 1301 fn = sn; 1302 } 1303 #endif 1304 1305 err = fib6_add_rt2node(fn, rt, info, extack); 1306 if (!err) { 1307 __fib6_update_sernum_upto_root(rt, sernum); 1308 fib6_start_gc(info->nl_net, rt); 1309 } 1310 1311 out: 1312 if (err) { 1313 #ifdef CONFIG_IPV6_SUBTREES 1314 /* 1315 * If fib6_add_1 has cleared the old leaf pointer in the 1316 * super-tree leaf node we have to find a new one for it. 1317 */ 1318 if (pn != fn) { 1319 struct fib6_info *pn_leaf = 1320 rcu_dereference_protected(pn->leaf, 1321 lockdep_is_held(&table->tb6_lock)); 1322 if (pn_leaf == rt) { 1323 pn_leaf = NULL; 1324 RCU_INIT_POINTER(pn->leaf, NULL); 1325 fib6_info_release(rt); 1326 } 1327 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) { 1328 pn_leaf = fib6_find_prefix(info->nl_net, table, 1329 pn); 1330 #if RT6_DEBUG >= 2 1331 if (!pn_leaf) { 1332 WARN_ON(!pn_leaf); 1333 pn_leaf = 1334 info->nl_net->ipv6.fib6_null_entry; 1335 } 1336 #endif 1337 fib6_info_hold(pn_leaf); 1338 rcu_assign_pointer(pn->leaf, pn_leaf); 1339 } 1340 } 1341 #endif 1342 goto failure; 1343 } 1344 return err; 1345 1346 failure: 1347 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if: 1348 * 1. fn is an intermediate node and we failed to add the new 1349 * route to it in both subtree creation failure and fib6_add_rt2node() 1350 * failure case. 1351 * 2. fn is the root node in the table and we fail to add the first 1352 * default route to it. 1353 */ 1354 if (fn && 1355 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) || 1356 (fn->fn_flags & RTN_TL_ROOT && 1357 !rcu_access_pointer(fn->leaf)))) 1358 fib6_repair_tree(info->nl_net, table, fn); 1359 return err; 1360 } 1361 1362 /* 1363 * Routing tree lookup 1364 * 1365 */ 1366 1367 struct lookup_args { 1368 int offset; /* key offset on fib6_info */ 1369 const struct in6_addr *addr; /* search key */ 1370 }; 1371 1372 static struct fib6_node *fib6_node_lookup_1(struct fib6_node *root, 1373 struct lookup_args *args) 1374 { 1375 struct fib6_node *fn; 1376 __be32 dir; 1377 1378 if (unlikely(args->offset == 0)) 1379 return NULL; 1380 1381 /* 1382 * Descend on a tree 1383 */ 1384 1385 fn = root; 1386 1387 for (;;) { 1388 struct fib6_node *next; 1389 1390 dir = addr_bit_set(args->addr, fn->fn_bit); 1391 1392 next = dir ? rcu_dereference(fn->right) : 1393 rcu_dereference(fn->left); 1394 1395 if (next) { 1396 fn = next; 1397 continue; 1398 } 1399 break; 1400 } 1401 1402 while (fn) { 1403 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1404 1405 if (subtree || fn->fn_flags & RTN_RTINFO) { 1406 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1407 struct rt6key *key; 1408 1409 if (!leaf) 1410 goto backtrack; 1411 1412 key = (struct rt6key *) ((u8 *)leaf + args->offset); 1413 1414 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1415 #ifdef CONFIG_IPV6_SUBTREES 1416 if (subtree) { 1417 struct fib6_node *sfn; 1418 sfn = fib6_node_lookup_1(subtree, 1419 args + 1); 1420 if (!sfn) 1421 goto backtrack; 1422 fn = sfn; 1423 } 1424 #endif 1425 if (fn->fn_flags & RTN_RTINFO) 1426 return fn; 1427 } 1428 } 1429 backtrack: 1430 if (fn->fn_flags & RTN_ROOT) 1431 break; 1432 1433 fn = rcu_dereference(fn->parent); 1434 } 1435 1436 return NULL; 1437 } 1438 1439 /* called with rcu_read_lock() held 1440 */ 1441 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 1442 const struct in6_addr *daddr, 1443 const struct in6_addr *saddr) 1444 { 1445 struct fib6_node *fn; 1446 struct lookup_args args[] = { 1447 { 1448 .offset = offsetof(struct fib6_info, fib6_dst), 1449 .addr = daddr, 1450 }, 1451 #ifdef CONFIG_IPV6_SUBTREES 1452 { 1453 .offset = offsetof(struct fib6_info, fib6_src), 1454 .addr = saddr, 1455 }, 1456 #endif 1457 { 1458 .offset = 0, /* sentinel */ 1459 } 1460 }; 1461 1462 fn = fib6_node_lookup_1(root, daddr ? args : args + 1); 1463 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1464 fn = root; 1465 1466 return fn; 1467 } 1468 1469 /* 1470 * Get node with specified destination prefix (and source prefix, 1471 * if subtrees are used) 1472 * exact_match == true means we try to find fn with exact match of 1473 * the passed in prefix addr 1474 * exact_match == false means we try to find fn with longest prefix 1475 * match of the passed in prefix addr. This is useful for finding fn 1476 * for cached route as it will be stored in the exception table under 1477 * the node with longest prefix length. 1478 */ 1479 1480 1481 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1482 const struct in6_addr *addr, 1483 int plen, int offset, 1484 bool exact_match) 1485 { 1486 struct fib6_node *fn, *prev = NULL; 1487 1488 for (fn = root; fn ; ) { 1489 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1490 struct rt6key *key; 1491 1492 /* This node is being deleted */ 1493 if (!leaf) { 1494 if (plen <= fn->fn_bit) 1495 goto out; 1496 else 1497 goto next; 1498 } 1499 1500 key = (struct rt6key *)((u8 *)leaf + offset); 1501 1502 /* 1503 * Prefix match 1504 */ 1505 if (plen < fn->fn_bit || 1506 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1507 goto out; 1508 1509 if (plen == fn->fn_bit) 1510 return fn; 1511 1512 prev = fn; 1513 1514 next: 1515 /* 1516 * We have more bits to go 1517 */ 1518 if (addr_bit_set(addr, fn->fn_bit)) 1519 fn = rcu_dereference(fn->right); 1520 else 1521 fn = rcu_dereference(fn->left); 1522 } 1523 out: 1524 if (exact_match) 1525 return NULL; 1526 else 1527 return prev; 1528 } 1529 1530 struct fib6_node *fib6_locate(struct fib6_node *root, 1531 const struct in6_addr *daddr, int dst_len, 1532 const struct in6_addr *saddr, int src_len, 1533 bool exact_match) 1534 { 1535 struct fib6_node *fn; 1536 1537 fn = fib6_locate_1(root, daddr, dst_len, 1538 offsetof(struct fib6_info, fib6_dst), 1539 exact_match); 1540 1541 #ifdef CONFIG_IPV6_SUBTREES 1542 if (src_len) { 1543 WARN_ON(saddr == NULL); 1544 if (fn) { 1545 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1546 1547 if (subtree) { 1548 fn = fib6_locate_1(subtree, saddr, src_len, 1549 offsetof(struct fib6_info, fib6_src), 1550 exact_match); 1551 } 1552 } 1553 } 1554 #endif 1555 1556 if (fn && fn->fn_flags & RTN_RTINFO) 1557 return fn; 1558 1559 return NULL; 1560 } 1561 1562 1563 /* 1564 * Deletion 1565 * 1566 */ 1567 1568 static struct fib6_info *fib6_find_prefix(struct net *net, 1569 struct fib6_table *table, 1570 struct fib6_node *fn) 1571 { 1572 struct fib6_node *child_left, *child_right; 1573 1574 if (fn->fn_flags & RTN_ROOT) 1575 return net->ipv6.fib6_null_entry; 1576 1577 while (fn) { 1578 child_left = rcu_dereference_protected(fn->left, 1579 lockdep_is_held(&table->tb6_lock)); 1580 child_right = rcu_dereference_protected(fn->right, 1581 lockdep_is_held(&table->tb6_lock)); 1582 if (child_left) 1583 return rcu_dereference_protected(child_left->leaf, 1584 lockdep_is_held(&table->tb6_lock)); 1585 if (child_right) 1586 return rcu_dereference_protected(child_right->leaf, 1587 lockdep_is_held(&table->tb6_lock)); 1588 1589 fn = FIB6_SUBTREE(fn); 1590 } 1591 return NULL; 1592 } 1593 1594 /* 1595 * Called to trim the tree of intermediate nodes when possible. "fn" 1596 * is the node we want to try and remove. 1597 * Need to own table->tb6_lock 1598 */ 1599 1600 static struct fib6_node *fib6_repair_tree(struct net *net, 1601 struct fib6_table *table, 1602 struct fib6_node *fn) 1603 { 1604 int children; 1605 int nstate; 1606 struct fib6_node *child; 1607 struct fib6_walker *w; 1608 int iter = 0; 1609 1610 /* Set fn->leaf to null_entry for root node. */ 1611 if (fn->fn_flags & RTN_TL_ROOT) { 1612 rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry); 1613 return fn; 1614 } 1615 1616 for (;;) { 1617 struct fib6_node *fn_r = rcu_dereference_protected(fn->right, 1618 lockdep_is_held(&table->tb6_lock)); 1619 struct fib6_node *fn_l = rcu_dereference_protected(fn->left, 1620 lockdep_is_held(&table->tb6_lock)); 1621 struct fib6_node *pn = rcu_dereference_protected(fn->parent, 1622 lockdep_is_held(&table->tb6_lock)); 1623 struct fib6_node *pn_r = rcu_dereference_protected(pn->right, 1624 lockdep_is_held(&table->tb6_lock)); 1625 struct fib6_node *pn_l = rcu_dereference_protected(pn->left, 1626 lockdep_is_held(&table->tb6_lock)); 1627 struct fib6_info *fn_leaf = rcu_dereference_protected(fn->leaf, 1628 lockdep_is_held(&table->tb6_lock)); 1629 struct fib6_info *pn_leaf = rcu_dereference_protected(pn->leaf, 1630 lockdep_is_held(&table->tb6_lock)); 1631 struct fib6_info *new_fn_leaf; 1632 1633 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1634 iter++; 1635 1636 WARN_ON(fn->fn_flags & RTN_RTINFO); 1637 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1638 WARN_ON(fn_leaf); 1639 1640 children = 0; 1641 child = NULL; 1642 if (fn_r) 1643 child = fn_r, children |= 1; 1644 if (fn_l) 1645 child = fn_l, children |= 2; 1646 1647 if (children == 3 || FIB6_SUBTREE(fn) 1648 #ifdef CONFIG_IPV6_SUBTREES 1649 /* Subtree root (i.e. fn) may have one child */ 1650 || (children && fn->fn_flags & RTN_ROOT) 1651 #endif 1652 ) { 1653 new_fn_leaf = fib6_find_prefix(net, table, fn); 1654 #if RT6_DEBUG >= 2 1655 if (!new_fn_leaf) { 1656 WARN_ON(!new_fn_leaf); 1657 new_fn_leaf = net->ipv6.fib6_null_entry; 1658 } 1659 #endif 1660 fib6_info_hold(new_fn_leaf); 1661 rcu_assign_pointer(fn->leaf, new_fn_leaf); 1662 return pn; 1663 } 1664 1665 #ifdef CONFIG_IPV6_SUBTREES 1666 if (FIB6_SUBTREE(pn) == fn) { 1667 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1668 RCU_INIT_POINTER(pn->subtree, NULL); 1669 nstate = FWS_L; 1670 } else { 1671 WARN_ON(fn->fn_flags & RTN_ROOT); 1672 #endif 1673 if (pn_r == fn) 1674 rcu_assign_pointer(pn->right, child); 1675 else if (pn_l == fn) 1676 rcu_assign_pointer(pn->left, child); 1677 #if RT6_DEBUG >= 2 1678 else 1679 WARN_ON(1); 1680 #endif 1681 if (child) 1682 rcu_assign_pointer(child->parent, pn); 1683 nstate = FWS_R; 1684 #ifdef CONFIG_IPV6_SUBTREES 1685 } 1686 #endif 1687 1688 read_lock(&net->ipv6.fib6_walker_lock); 1689 FOR_WALKERS(net, w) { 1690 if (!child) { 1691 if (w->node == fn) { 1692 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1693 w->node = pn; 1694 w->state = nstate; 1695 } 1696 } else { 1697 if (w->node == fn) { 1698 w->node = child; 1699 if (children&2) { 1700 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1701 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1702 } else { 1703 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1704 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1705 } 1706 } 1707 } 1708 } 1709 read_unlock(&net->ipv6.fib6_walker_lock); 1710 1711 node_free(net, fn); 1712 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1713 return pn; 1714 1715 RCU_INIT_POINTER(pn->leaf, NULL); 1716 fib6_info_release(pn_leaf); 1717 fn = pn; 1718 } 1719 } 1720 1721 static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn, 1722 struct fib6_info __rcu **rtp, struct nl_info *info) 1723 { 1724 struct fib6_walker *w; 1725 struct fib6_info *rt = rcu_dereference_protected(*rtp, 1726 lockdep_is_held(&table->tb6_lock)); 1727 struct net *net = info->nl_net; 1728 1729 RT6_TRACE("fib6_del_route\n"); 1730 1731 /* Unlink it */ 1732 *rtp = rt->fib6_next; 1733 rt->fib6_node = NULL; 1734 net->ipv6.rt6_stats->fib_rt_entries--; 1735 net->ipv6.rt6_stats->fib_discarded_routes++; 1736 1737 /* Flush all cached dst in exception table */ 1738 rt6_flush_exceptions(rt); 1739 1740 /* Reset round-robin state, if necessary */ 1741 if (rcu_access_pointer(fn->rr_ptr) == rt) 1742 fn->rr_ptr = NULL; 1743 1744 /* Remove this entry from other siblings */ 1745 if (rt->fib6_nsiblings) { 1746 struct fib6_info *sibling, *next_sibling; 1747 1748 list_for_each_entry_safe(sibling, next_sibling, 1749 &rt->fib6_siblings, fib6_siblings) 1750 sibling->fib6_nsiblings--; 1751 rt->fib6_nsiblings = 0; 1752 list_del_init(&rt->fib6_siblings); 1753 rt6_multipath_rebalance(next_sibling); 1754 } 1755 1756 /* Adjust walkers */ 1757 read_lock(&net->ipv6.fib6_walker_lock); 1758 FOR_WALKERS(net, w) { 1759 if (w->state == FWS_C && w->leaf == rt) { 1760 RT6_TRACE("walker %p adjusted by delroute\n", w); 1761 w->leaf = rcu_dereference_protected(rt->fib6_next, 1762 lockdep_is_held(&table->tb6_lock)); 1763 if (!w->leaf) 1764 w->state = FWS_U; 1765 } 1766 } 1767 read_unlock(&net->ipv6.fib6_walker_lock); 1768 1769 /* If it was last route, call fib6_repair_tree() to: 1770 * 1. For root node, put back null_entry as how the table was created. 1771 * 2. For other nodes, expunge its radix tree node. 1772 */ 1773 if (!rcu_access_pointer(fn->leaf)) { 1774 if (!(fn->fn_flags & RTN_TL_ROOT)) { 1775 fn->fn_flags &= ~RTN_RTINFO; 1776 net->ipv6.rt6_stats->fib_route_nodes--; 1777 } 1778 fn = fib6_repair_tree(net, table, fn); 1779 } 1780 1781 fib6_purge_rt(rt, fn, net); 1782 1783 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL); 1784 if (!info->skip_notify) 1785 inet6_rt_notify(RTM_DELROUTE, rt, info, 0); 1786 fib6_info_release(rt); 1787 } 1788 1789 /* Need to own table->tb6_lock */ 1790 int fib6_del(struct fib6_info *rt, struct nl_info *info) 1791 { 1792 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1793 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1794 struct fib6_table *table = rt->fib6_table; 1795 struct net *net = info->nl_net; 1796 struct fib6_info __rcu **rtp; 1797 struct fib6_info __rcu **rtp_next; 1798 1799 if (!fn || rt == net->ipv6.fib6_null_entry) 1800 return -ENOENT; 1801 1802 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1803 1804 /* 1805 * Walk the leaf entries looking for ourself 1806 */ 1807 1808 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) { 1809 struct fib6_info *cur = rcu_dereference_protected(*rtp, 1810 lockdep_is_held(&table->tb6_lock)); 1811 if (rt == cur) { 1812 fib6_del_route(table, fn, rtp, info); 1813 return 0; 1814 } 1815 rtp_next = &cur->fib6_next; 1816 } 1817 return -ENOENT; 1818 } 1819 1820 /* 1821 * Tree traversal function. 1822 * 1823 * Certainly, it is not interrupt safe. 1824 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1825 * It means, that we can modify tree during walking 1826 * and use this function for garbage collection, clone pruning, 1827 * cleaning tree when a device goes down etc. etc. 1828 * 1829 * It guarantees that every node will be traversed, 1830 * and that it will be traversed only once. 1831 * 1832 * Callback function w->func may return: 1833 * 0 -> continue walking. 1834 * positive value -> walking is suspended (used by tree dumps, 1835 * and probably by gc, if it will be split to several slices) 1836 * negative value -> terminate walking. 1837 * 1838 * The function itself returns: 1839 * 0 -> walk is complete. 1840 * >0 -> walk is incomplete (i.e. suspended) 1841 * <0 -> walk is terminated by an error. 1842 * 1843 * This function is called with tb6_lock held. 1844 */ 1845 1846 static int fib6_walk_continue(struct fib6_walker *w) 1847 { 1848 struct fib6_node *fn, *pn, *left, *right; 1849 1850 /* w->root should always be table->tb6_root */ 1851 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT)); 1852 1853 for (;;) { 1854 fn = w->node; 1855 if (!fn) 1856 return 0; 1857 1858 switch (w->state) { 1859 #ifdef CONFIG_IPV6_SUBTREES 1860 case FWS_S: 1861 if (FIB6_SUBTREE(fn)) { 1862 w->node = FIB6_SUBTREE(fn); 1863 continue; 1864 } 1865 w->state = FWS_L; 1866 #endif 1867 /* fall through */ 1868 case FWS_L: 1869 left = rcu_dereference_protected(fn->left, 1); 1870 if (left) { 1871 w->node = left; 1872 w->state = FWS_INIT; 1873 continue; 1874 } 1875 w->state = FWS_R; 1876 /* fall through */ 1877 case FWS_R: 1878 right = rcu_dereference_protected(fn->right, 1); 1879 if (right) { 1880 w->node = right; 1881 w->state = FWS_INIT; 1882 continue; 1883 } 1884 w->state = FWS_C; 1885 w->leaf = rcu_dereference_protected(fn->leaf, 1); 1886 /* fall through */ 1887 case FWS_C: 1888 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1889 int err; 1890 1891 if (w->skip) { 1892 w->skip--; 1893 goto skip; 1894 } 1895 1896 err = w->func(w); 1897 if (err) 1898 return err; 1899 1900 w->count++; 1901 continue; 1902 } 1903 skip: 1904 w->state = FWS_U; 1905 /* fall through */ 1906 case FWS_U: 1907 if (fn == w->root) 1908 return 0; 1909 pn = rcu_dereference_protected(fn->parent, 1); 1910 left = rcu_dereference_protected(pn->left, 1); 1911 right = rcu_dereference_protected(pn->right, 1); 1912 w->node = pn; 1913 #ifdef CONFIG_IPV6_SUBTREES 1914 if (FIB6_SUBTREE(pn) == fn) { 1915 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1916 w->state = FWS_L; 1917 continue; 1918 } 1919 #endif 1920 if (left == fn) { 1921 w->state = FWS_R; 1922 continue; 1923 } 1924 if (right == fn) { 1925 w->state = FWS_C; 1926 w->leaf = rcu_dereference_protected(w->node->leaf, 1); 1927 continue; 1928 } 1929 #if RT6_DEBUG >= 2 1930 WARN_ON(1); 1931 #endif 1932 } 1933 } 1934 } 1935 1936 static int fib6_walk(struct net *net, struct fib6_walker *w) 1937 { 1938 int res; 1939 1940 w->state = FWS_INIT; 1941 w->node = w->root; 1942 1943 fib6_walker_link(net, w); 1944 res = fib6_walk_continue(w); 1945 if (res <= 0) 1946 fib6_walker_unlink(net, w); 1947 return res; 1948 } 1949 1950 static int fib6_clean_node(struct fib6_walker *w) 1951 { 1952 int res; 1953 struct fib6_info *rt; 1954 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 1955 struct nl_info info = { 1956 .nl_net = c->net, 1957 }; 1958 1959 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 1960 w->node->fn_sernum != c->sernum) 1961 w->node->fn_sernum = c->sernum; 1962 1963 if (!c->func) { 1964 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 1965 w->leaf = NULL; 1966 return 0; 1967 } 1968 1969 for_each_fib6_walker_rt(w) { 1970 res = c->func(rt, c->arg); 1971 if (res == -1) { 1972 w->leaf = rt; 1973 res = fib6_del(rt, &info); 1974 if (res) { 1975 #if RT6_DEBUG >= 2 1976 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 1977 __func__, rt, 1978 rcu_access_pointer(rt->fib6_node), 1979 res); 1980 #endif 1981 continue; 1982 } 1983 return 0; 1984 } else if (res == -2) { 1985 if (WARN_ON(!rt->fib6_nsiblings)) 1986 continue; 1987 rt = list_last_entry(&rt->fib6_siblings, 1988 struct fib6_info, fib6_siblings); 1989 continue; 1990 } 1991 WARN_ON(res != 0); 1992 } 1993 w->leaf = rt; 1994 return 0; 1995 } 1996 1997 /* 1998 * Convenient frontend to tree walker. 1999 * 2000 * func is called on each route. 2001 * It may return -2 -> skip multipath route. 2002 * -1 -> delete this route. 2003 * 0 -> continue walking 2004 */ 2005 2006 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 2007 int (*func)(struct fib6_info *, void *arg), 2008 int sernum, void *arg) 2009 { 2010 struct fib6_cleaner c; 2011 2012 c.w.root = root; 2013 c.w.func = fib6_clean_node; 2014 c.w.count = 0; 2015 c.w.skip = 0; 2016 c.func = func; 2017 c.sernum = sernum; 2018 c.arg = arg; 2019 c.net = net; 2020 2021 fib6_walk(net, &c.w); 2022 } 2023 2024 static void __fib6_clean_all(struct net *net, 2025 int (*func)(struct fib6_info *, void *), 2026 int sernum, void *arg) 2027 { 2028 struct fib6_table *table; 2029 struct hlist_head *head; 2030 unsigned int h; 2031 2032 rcu_read_lock(); 2033 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 2034 head = &net->ipv6.fib_table_hash[h]; 2035 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 2036 spin_lock_bh(&table->tb6_lock); 2037 fib6_clean_tree(net, &table->tb6_root, 2038 func, sernum, arg); 2039 spin_unlock_bh(&table->tb6_lock); 2040 } 2041 } 2042 rcu_read_unlock(); 2043 } 2044 2045 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *), 2046 void *arg) 2047 { 2048 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg); 2049 } 2050 2051 static void fib6_flush_trees(struct net *net) 2052 { 2053 int new_sernum = fib6_new_sernum(net); 2054 2055 __fib6_clean_all(net, NULL, new_sernum, NULL); 2056 } 2057 2058 /* 2059 * Garbage collection 2060 */ 2061 2062 static int fib6_age(struct fib6_info *rt, void *arg) 2063 { 2064 struct fib6_gc_args *gc_args = arg; 2065 unsigned long now = jiffies; 2066 2067 /* 2068 * check addrconf expiration here. 2069 * Routes are expired even if they are in use. 2070 */ 2071 2072 if (rt->fib6_flags & RTF_EXPIRES && rt->expires) { 2073 if (time_after(now, rt->expires)) { 2074 RT6_TRACE("expiring %p\n", rt); 2075 return -1; 2076 } 2077 gc_args->more++; 2078 } 2079 2080 /* Also age clones in the exception table. 2081 * Note, that clones are aged out 2082 * only if they are not in use now. 2083 */ 2084 rt6_age_exceptions(rt, gc_args, now); 2085 2086 return 0; 2087 } 2088 2089 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 2090 { 2091 struct fib6_gc_args gc_args; 2092 unsigned long now; 2093 2094 if (force) { 2095 spin_lock_bh(&net->ipv6.fib6_gc_lock); 2096 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) { 2097 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 2098 return; 2099 } 2100 gc_args.timeout = expires ? (int)expires : 2101 net->ipv6.sysctl.ip6_rt_gc_interval; 2102 gc_args.more = 0; 2103 2104 fib6_clean_all(net, fib6_age, &gc_args); 2105 now = jiffies; 2106 net->ipv6.ip6_rt_last_gc = now; 2107 2108 if (gc_args.more) 2109 mod_timer(&net->ipv6.ip6_fib_timer, 2110 round_jiffies(now 2111 + net->ipv6.sysctl.ip6_rt_gc_interval)); 2112 else 2113 del_timer(&net->ipv6.ip6_fib_timer); 2114 spin_unlock_bh(&net->ipv6.fib6_gc_lock); 2115 } 2116 2117 static void fib6_gc_timer_cb(struct timer_list *t) 2118 { 2119 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer); 2120 2121 fib6_run_gc(0, arg, true); 2122 } 2123 2124 static int __net_init fib6_net_init(struct net *net) 2125 { 2126 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 2127 int err; 2128 2129 err = fib6_notifier_init(net); 2130 if (err) 2131 return err; 2132 2133 spin_lock_init(&net->ipv6.fib6_gc_lock); 2134 rwlock_init(&net->ipv6.fib6_walker_lock); 2135 INIT_LIST_HEAD(&net->ipv6.fib6_walkers); 2136 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0); 2137 2138 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 2139 if (!net->ipv6.rt6_stats) 2140 goto out_timer; 2141 2142 /* Avoid false sharing : Use at least a full cache line */ 2143 size = max_t(size_t, size, L1_CACHE_BYTES); 2144 2145 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 2146 if (!net->ipv6.fib_table_hash) 2147 goto out_rt6_stats; 2148 2149 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 2150 GFP_KERNEL); 2151 if (!net->ipv6.fib6_main_tbl) 2152 goto out_fib_table_hash; 2153 2154 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 2155 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf, 2156 net->ipv6.fib6_null_entry); 2157 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 2158 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2159 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 2160 2161 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2162 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 2163 GFP_KERNEL); 2164 if (!net->ipv6.fib6_local_tbl) 2165 goto out_fib6_main_tbl; 2166 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 2167 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf, 2168 net->ipv6.fib6_null_entry); 2169 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 2170 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2171 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 2172 #endif 2173 fib6_tables_init(net); 2174 2175 return 0; 2176 2177 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2178 out_fib6_main_tbl: 2179 kfree(net->ipv6.fib6_main_tbl); 2180 #endif 2181 out_fib_table_hash: 2182 kfree(net->ipv6.fib_table_hash); 2183 out_rt6_stats: 2184 kfree(net->ipv6.rt6_stats); 2185 out_timer: 2186 fib6_notifier_exit(net); 2187 return -ENOMEM; 2188 } 2189 2190 static void fib6_net_exit(struct net *net) 2191 { 2192 unsigned int i; 2193 2194 del_timer_sync(&net->ipv6.ip6_fib_timer); 2195 2196 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) { 2197 struct hlist_head *head = &net->ipv6.fib_table_hash[i]; 2198 struct hlist_node *tmp; 2199 struct fib6_table *tb; 2200 2201 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) { 2202 hlist_del(&tb->tb6_hlist); 2203 fib6_free_table(tb); 2204 } 2205 } 2206 2207 kfree(net->ipv6.fib_table_hash); 2208 kfree(net->ipv6.rt6_stats); 2209 fib6_notifier_exit(net); 2210 } 2211 2212 static struct pernet_operations fib6_net_ops = { 2213 .init = fib6_net_init, 2214 .exit = fib6_net_exit, 2215 }; 2216 2217 int __init fib6_init(void) 2218 { 2219 int ret = -ENOMEM; 2220 2221 fib6_node_kmem = kmem_cache_create("fib6_nodes", 2222 sizeof(struct fib6_node), 2223 0, SLAB_HWCACHE_ALIGN, 2224 NULL); 2225 if (!fib6_node_kmem) 2226 goto out; 2227 2228 ret = register_pernet_subsys(&fib6_net_ops); 2229 if (ret) 2230 goto out_kmem_cache_create; 2231 2232 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL, 2233 inet6_dump_fib, 0); 2234 if (ret) 2235 goto out_unregister_subsys; 2236 2237 __fib6_flush_trees = fib6_flush_trees; 2238 out: 2239 return ret; 2240 2241 out_unregister_subsys: 2242 unregister_pernet_subsys(&fib6_net_ops); 2243 out_kmem_cache_create: 2244 kmem_cache_destroy(fib6_node_kmem); 2245 goto out; 2246 } 2247 2248 void fib6_gc_cleanup(void) 2249 { 2250 unregister_pernet_subsys(&fib6_net_ops); 2251 kmem_cache_destroy(fib6_node_kmem); 2252 } 2253 2254 #ifdef CONFIG_PROC_FS 2255 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 2256 { 2257 struct fib6_info *rt = v; 2258 struct ipv6_route_iter *iter = seq->private; 2259 const struct net_device *dev; 2260 2261 seq_printf(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen); 2262 2263 #ifdef CONFIG_IPV6_SUBTREES 2264 seq_printf(seq, "%pi6 %02x ", &rt->fib6_src.addr, rt->fib6_src.plen); 2265 #else 2266 seq_puts(seq, "00000000000000000000000000000000 00 "); 2267 #endif 2268 if (rt->fib6_flags & RTF_GATEWAY) 2269 seq_printf(seq, "%pi6", &rt->fib6_nh.nh_gw); 2270 else 2271 seq_puts(seq, "00000000000000000000000000000000"); 2272 2273 dev = rt->fib6_nh.nh_dev; 2274 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 2275 rt->fib6_metric, atomic_read(&rt->fib6_ref), 0, 2276 rt->fib6_flags, dev ? dev->name : ""); 2277 iter->w.leaf = NULL; 2278 return 0; 2279 } 2280 2281 static int ipv6_route_yield(struct fib6_walker *w) 2282 { 2283 struct ipv6_route_iter *iter = w->args; 2284 2285 if (!iter->skip) 2286 return 1; 2287 2288 do { 2289 iter->w.leaf = rcu_dereference_protected( 2290 iter->w.leaf->fib6_next, 2291 lockdep_is_held(&iter->tbl->tb6_lock)); 2292 iter->skip--; 2293 if (!iter->skip && iter->w.leaf) 2294 return 1; 2295 } while (iter->w.leaf); 2296 2297 return 0; 2298 } 2299 2300 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter, 2301 struct net *net) 2302 { 2303 memset(&iter->w, 0, sizeof(iter->w)); 2304 iter->w.func = ipv6_route_yield; 2305 iter->w.root = &iter->tbl->tb6_root; 2306 iter->w.state = FWS_INIT; 2307 iter->w.node = iter->w.root; 2308 iter->w.args = iter; 2309 iter->sernum = iter->w.root->fn_sernum; 2310 INIT_LIST_HEAD(&iter->w.lh); 2311 fib6_walker_link(net, &iter->w); 2312 } 2313 2314 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 2315 struct net *net) 2316 { 2317 unsigned int h; 2318 struct hlist_node *node; 2319 2320 if (tbl) { 2321 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 2322 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 2323 } else { 2324 h = 0; 2325 node = NULL; 2326 } 2327 2328 while (!node && h < FIB6_TABLE_HASHSZ) { 2329 node = rcu_dereference_bh( 2330 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 2331 } 2332 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 2333 } 2334 2335 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 2336 { 2337 if (iter->sernum != iter->w.root->fn_sernum) { 2338 iter->sernum = iter->w.root->fn_sernum; 2339 iter->w.state = FWS_INIT; 2340 iter->w.node = iter->w.root; 2341 WARN_ON(iter->w.skip); 2342 iter->w.skip = iter->w.count; 2343 } 2344 } 2345 2346 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2347 { 2348 int r; 2349 struct fib6_info *n; 2350 struct net *net = seq_file_net(seq); 2351 struct ipv6_route_iter *iter = seq->private; 2352 2353 if (!v) 2354 goto iter_table; 2355 2356 n = rcu_dereference_bh(((struct fib6_info *)v)->fib6_next); 2357 if (n) { 2358 ++*pos; 2359 return n; 2360 } 2361 2362 iter_table: 2363 ipv6_route_check_sernum(iter); 2364 spin_lock_bh(&iter->tbl->tb6_lock); 2365 r = fib6_walk_continue(&iter->w); 2366 spin_unlock_bh(&iter->tbl->tb6_lock); 2367 if (r > 0) { 2368 if (v) 2369 ++*pos; 2370 return iter->w.leaf; 2371 } else if (r < 0) { 2372 fib6_walker_unlink(net, &iter->w); 2373 return NULL; 2374 } 2375 fib6_walker_unlink(net, &iter->w); 2376 2377 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 2378 if (!iter->tbl) 2379 return NULL; 2380 2381 ipv6_route_seq_setup_walk(iter, net); 2382 goto iter_table; 2383 } 2384 2385 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 2386 __acquires(RCU_BH) 2387 { 2388 struct net *net = seq_file_net(seq); 2389 struct ipv6_route_iter *iter = seq->private; 2390 2391 rcu_read_lock_bh(); 2392 iter->tbl = ipv6_route_seq_next_table(NULL, net); 2393 iter->skip = *pos; 2394 2395 if (iter->tbl) { 2396 ipv6_route_seq_setup_walk(iter, net); 2397 return ipv6_route_seq_next(seq, NULL, pos); 2398 } else { 2399 return NULL; 2400 } 2401 } 2402 2403 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 2404 { 2405 struct fib6_walker *w = &iter->w; 2406 return w->node && !(w->state == FWS_U && w->node == w->root); 2407 } 2408 2409 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2410 __releases(RCU_BH) 2411 { 2412 struct net *net = seq_file_net(seq); 2413 struct ipv6_route_iter *iter = seq->private; 2414 2415 if (ipv6_route_iter_active(iter)) 2416 fib6_walker_unlink(net, &iter->w); 2417 2418 rcu_read_unlock_bh(); 2419 } 2420 2421 const struct seq_operations ipv6_route_seq_ops = { 2422 .start = ipv6_route_seq_start, 2423 .next = ipv6_route_seq_next, 2424 .stop = ipv6_route_seq_stop, 2425 .show = ipv6_route_seq_show 2426 }; 2427 #endif /* CONFIG_PROC_FS */ 2428