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