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/ip.h> 33 #include <net/ipv6.h> 34 #include <net/ndisc.h> 35 #include <net/addrconf.h> 36 #include <net/lwtunnel.h> 37 #include <net/fib_notifier.h> 38 39 #include <net/ip6_fib.h> 40 #include <net/ip6_route.h> 41 42 static struct kmem_cache *fib6_node_kmem __read_mostly; 43 44 struct fib6_cleaner { 45 struct fib6_walker w; 46 struct net *net; 47 int (*func)(struct fib6_info *, void *arg); 48 int sernum; 49 void *arg; 50 bool skip_notify; 51 }; 52 53 #ifdef CONFIG_IPV6_SUBTREES 54 #define FWS_INIT FWS_S 55 #else 56 #define FWS_INIT FWS_L 57 #endif 58 59 static struct fib6_info *fib6_find_prefix(struct net *net, 60 struct fib6_table *table, 61 struct fib6_node *fn); 62 static struct fib6_node *fib6_repair_tree(struct net *net, 63 struct fib6_table *table, 64 struct fib6_node *fn); 65 static int fib6_walk(struct net *net, struct fib6_walker *w); 66 static int fib6_walk_continue(struct fib6_walker *w); 67 68 /* 69 * A routing update causes an increase of the serial number on the 70 * affected subtree. This allows for cached routes to be asynchronously 71 * tested when modifications are made to the destination cache as a 72 * result of redirects, path MTU changes, etc. 73 */ 74 75 static void fib6_gc_timer_cb(struct timer_list *t); 76 77 #define FOR_WALKERS(net, w) \ 78 list_for_each_entry(w, &(net)->ipv6.fib6_walkers, lh) 79 80 static void fib6_walker_link(struct net *net, struct fib6_walker *w) 81 { 82 write_lock_bh(&net->ipv6.fib6_walker_lock); 83 list_add(&w->lh, &net->ipv6.fib6_walkers); 84 write_unlock_bh(&net->ipv6.fib6_walker_lock); 85 } 86 87 static void fib6_walker_unlink(struct net *net, struct fib6_walker *w) 88 { 89 write_lock_bh(&net->ipv6.fib6_walker_lock); 90 list_del(&w->lh); 91 write_unlock_bh(&net->ipv6.fib6_walker_lock); 92 } 93 94 static int fib6_new_sernum(struct net *net) 95 { 96 int new, old; 97 98 do { 99 old = atomic_read(&net->ipv6.fib6_sernum); 100 new = old < INT_MAX ? old + 1 : 1; 101 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum, 102 old, new) != old); 103 return new; 104 } 105 106 enum { 107 FIB6_NO_SERNUM_CHANGE = 0, 108 }; 109 110 void fib6_update_sernum(struct net *net, struct fib6_info *f6i) 111 { 112 struct fib6_node *fn; 113 114 fn = rcu_dereference_protected(f6i->fib6_node, 115 lockdep_is_held(&f6i->fib6_table->tb6_lock)); 116 if (fn) 117 fn->fn_sernum = fib6_new_sernum(net); 118 } 119 120 /* 121 * Auxiliary address test functions for the radix tree. 122 * 123 * These assume a 32bit processor (although it will work on 124 * 64bit processors) 125 */ 126 127 /* 128 * test bit 129 */ 130 #if defined(__LITTLE_ENDIAN) 131 # define BITOP_BE32_SWIZZLE (0x1F & ~7) 132 #else 133 # define BITOP_BE32_SWIZZLE 0 134 #endif 135 136 static __be32 addr_bit_set(const void *token, int fn_bit) 137 { 138 const __be32 *addr = token; 139 /* 140 * Here, 141 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f) 142 * is optimized version of 143 * htonl(1 << ((~fn_bit)&0x1F)) 144 * See include/asm-generic/bitops/le.h. 145 */ 146 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) & 147 addr[fn_bit >> 5]; 148 } 149 150 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags) 151 { 152 struct fib6_info *f6i; 153 154 f6i = kzalloc(sizeof(*f6i), gfp_flags); 155 if (!f6i) 156 return NULL; 157 158 f6i->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags); 159 if (!f6i->rt6i_pcpu) { 160 kfree(f6i); 161 return NULL; 162 } 163 164 INIT_LIST_HEAD(&f6i->fib6_siblings); 165 refcount_set(&f6i->fib6_ref, 1); 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; 174 175 WARN_ON(f6i->fib6_node); 176 177 bucket = rcu_dereference_protected(f6i->rt6i_exception_bucket, 1); 178 kfree(bucket); 179 180 if (f6i->rt6i_pcpu) { 181 int cpu; 182 183 for_each_possible_cpu(cpu) { 184 struct rt6_info **ppcpu_rt; 185 struct rt6_info *pcpu_rt; 186 187 ppcpu_rt = per_cpu_ptr(f6i->rt6i_pcpu, cpu); 188 pcpu_rt = *ppcpu_rt; 189 if (pcpu_rt) { 190 dst_dev_put(&pcpu_rt->dst); 191 dst_release(&pcpu_rt->dst); 192 *ppcpu_rt = NULL; 193 } 194 } 195 196 free_percpu(f6i->rt6i_pcpu); 197 } 198 199 fib6_nh_release(&f6i->fib6_nh); 200 201 ip_fib_metrics_put(f6i->fib6_metrics); 202 203 kfree(f6i); 204 } 205 EXPORT_SYMBOL_GPL(fib6_info_destroy_rcu); 206 207 static struct fib6_node *node_alloc(struct net *net) 208 { 209 struct fib6_node *fn; 210 211 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); 212 if (fn) 213 net->ipv6.rt6_stats->fib_nodes++; 214 215 return fn; 216 } 217 218 static void node_free_immediate(struct net *net, struct fib6_node *fn) 219 { 220 kmem_cache_free(fib6_node_kmem, fn); 221 net->ipv6.rt6_stats->fib_nodes--; 222 } 223 224 static void node_free_rcu(struct rcu_head *head) 225 { 226 struct fib6_node *fn = container_of(head, struct fib6_node, rcu); 227 228 kmem_cache_free(fib6_node_kmem, fn); 229 } 230 231 static void node_free(struct net *net, struct fib6_node *fn) 232 { 233 call_rcu(&fn->rcu, node_free_rcu); 234 net->ipv6.rt6_stats->fib_nodes--; 235 } 236 237 static void fib6_free_table(struct fib6_table *table) 238 { 239 inetpeer_invalidate_tree(&table->tb6_peers); 240 kfree(table); 241 } 242 243 static void fib6_link_table(struct net *net, struct fib6_table *tb) 244 { 245 unsigned int h; 246 247 /* 248 * Initialize table lock at a single place to give lockdep a key, 249 * tables aren't visible prior to being linked to the list. 250 */ 251 spin_lock_init(&tb->tb6_lock); 252 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 253 254 /* 255 * No protection necessary, this is the only list mutatation 256 * operation, tables never disappear once they exist. 257 */ 258 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 259 } 260 261 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 262 263 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 264 { 265 struct fib6_table *table; 266 267 table = kzalloc(sizeof(*table), GFP_ATOMIC); 268 if (table) { 269 table->tb6_id = id; 270 rcu_assign_pointer(table->tb6_root.leaf, 271 net->ipv6.fib6_null_entry); 272 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 273 inet_peer_base_init(&table->tb6_peers); 274 } 275 276 return table; 277 } 278 279 struct fib6_table *fib6_new_table(struct net *net, u32 id) 280 { 281 struct fib6_table *tb; 282 283 if (id == 0) 284 id = RT6_TABLE_MAIN; 285 tb = fib6_get_table(net, id); 286 if (tb) 287 return tb; 288 289 tb = fib6_alloc_table(net, id); 290 if (tb) 291 fib6_link_table(net, tb); 292 293 return tb; 294 } 295 EXPORT_SYMBOL_GPL(fib6_new_table); 296 297 struct fib6_table *fib6_get_table(struct net *net, u32 id) 298 { 299 struct fib6_table *tb; 300 struct hlist_head *head; 301 unsigned int h; 302 303 if (id == 0) 304 id = RT6_TABLE_MAIN; 305 h = id & (FIB6_TABLE_HASHSZ - 1); 306 rcu_read_lock(); 307 head = &net->ipv6.fib_table_hash[h]; 308 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 309 if (tb->tb6_id == id) { 310 rcu_read_unlock(); 311 return tb; 312 } 313 } 314 rcu_read_unlock(); 315 316 return NULL; 317 } 318 EXPORT_SYMBOL_GPL(fib6_get_table); 319 320 static void __net_init fib6_tables_init(struct net *net) 321 { 322 fib6_link_table(net, net->ipv6.fib6_main_tbl); 323 fib6_link_table(net, net->ipv6.fib6_local_tbl); 324 } 325 #else 326 327 struct fib6_table *fib6_new_table(struct net *net, u32 id) 328 { 329 return fib6_get_table(net, id); 330 } 331 332 struct fib6_table *fib6_get_table(struct net *net, u32 id) 333 { 334 return net->ipv6.fib6_main_tbl; 335 } 336 337 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 338 const struct sk_buff *skb, 339 int flags, pol_lookup_t lookup) 340 { 341 struct rt6_info *rt; 342 343 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags); 344 if (rt->dst.error == -EAGAIN) { 345 ip6_rt_put(rt); 346 rt = net->ipv6.ip6_null_entry; 347 dst_hold(&rt->dst); 348 } 349 350 return &rt->dst; 351 } 352 353 /* called with rcu lock held; no reference taken on fib6_info */ 354 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 355 struct fib6_result *res, int flags) 356 { 357 return fib6_table_lookup(net, net->ipv6.fib6_main_tbl, oif, fl6, 358 res, flags); 359 } 360 361 static void __net_init fib6_tables_init(struct net *net) 362 { 363 fib6_link_table(net, net->ipv6.fib6_main_tbl); 364 } 365 366 #endif 367 368 unsigned int fib6_tables_seq_read(struct net *net) 369 { 370 unsigned int h, fib_seq = 0; 371 372 rcu_read_lock(); 373 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 374 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 375 struct fib6_table *tb; 376 377 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 378 fib_seq += tb->fib_seq; 379 } 380 rcu_read_unlock(); 381 382 return fib_seq; 383 } 384 385 static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net, 386 enum fib_event_type event_type, 387 struct fib6_info *rt) 388 { 389 struct fib6_entry_notifier_info info = { 390 .rt = rt, 391 }; 392 393 return call_fib6_notifier(nb, net, event_type, &info.info); 394 } 395 396 static int call_fib6_entry_notifiers(struct net *net, 397 enum fib_event_type event_type, 398 struct fib6_info *rt, 399 struct netlink_ext_ack *extack) 400 { 401 struct fib6_entry_notifier_info info = { 402 .info.extack = extack, 403 .rt = rt, 404 }; 405 406 rt->fib6_table->fib_seq++; 407 return call_fib6_notifiers(net, event_type, &info.info); 408 } 409 410 struct fib6_dump_arg { 411 struct net *net; 412 struct notifier_block *nb; 413 }; 414 415 static void fib6_rt_dump(struct fib6_info *rt, struct fib6_dump_arg *arg) 416 { 417 if (rt == arg->net->ipv6.fib6_null_entry) 418 return; 419 call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt); 420 } 421 422 static int fib6_node_dump(struct fib6_walker *w) 423 { 424 struct fib6_info *rt; 425 426 for_each_fib6_walker_rt(w) 427 fib6_rt_dump(rt, w->args); 428 w->leaf = NULL; 429 return 0; 430 } 431 432 static void fib6_table_dump(struct net *net, struct fib6_table *tb, 433 struct fib6_walker *w) 434 { 435 w->root = &tb->tb6_root; 436 spin_lock_bh(&tb->tb6_lock); 437 fib6_walk(net, w); 438 spin_unlock_bh(&tb->tb6_lock); 439 } 440 441 /* Called with rcu_read_lock() */ 442 int fib6_tables_dump(struct net *net, struct notifier_block *nb) 443 { 444 struct fib6_dump_arg arg; 445 struct fib6_walker *w; 446 unsigned int h; 447 448 w = kzalloc(sizeof(*w), GFP_ATOMIC); 449 if (!w) 450 return -ENOMEM; 451 452 w->func = fib6_node_dump; 453 arg.net = net; 454 arg.nb = nb; 455 w->args = &arg; 456 457 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 458 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 459 struct fib6_table *tb; 460 461 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 462 fib6_table_dump(net, tb, w); 463 } 464 465 kfree(w); 466 467 return 0; 468 } 469 470 static int fib6_dump_node(struct fib6_walker *w) 471 { 472 int res; 473 struct fib6_info *rt; 474 475 for_each_fib6_walker_rt(w) { 476 res = rt6_dump_route(rt, w->args); 477 if (res < 0) { 478 /* Frame is full, suspend walking */ 479 w->leaf = rt; 480 return 1; 481 } 482 483 /* Multipath routes are dumped in one route with the 484 * RTA_MULTIPATH attribute. Jump 'rt' to point to the 485 * last sibling of this route (no need to dump the 486 * sibling routes again) 487 */ 488 if (rt->fib6_nsiblings) 489 rt = list_last_entry(&rt->fib6_siblings, 490 struct fib6_info, 491 fib6_siblings); 492 } 493 w->leaf = NULL; 494 return 0; 495 } 496 497 static void fib6_dump_end(struct netlink_callback *cb) 498 { 499 struct net *net = sock_net(cb->skb->sk); 500 struct fib6_walker *w = (void *)cb->args[2]; 501 502 if (w) { 503 if (cb->args[4]) { 504 cb->args[4] = 0; 505 fib6_walker_unlink(net, w); 506 } 507 cb->args[2] = 0; 508 kfree(w); 509 } 510 cb->done = (void *)cb->args[3]; 511 cb->args[1] = 3; 512 } 513 514 static int fib6_dump_done(struct netlink_callback *cb) 515 { 516 fib6_dump_end(cb); 517 return cb->done ? cb->done(cb) : 0; 518 } 519 520 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 521 struct netlink_callback *cb) 522 { 523 struct net *net = sock_net(skb->sk); 524 struct fib6_walker *w; 525 int res; 526 527 w = (void *)cb->args[2]; 528 w->root = &table->tb6_root; 529 530 if (cb->args[4] == 0) { 531 w->count = 0; 532 w->skip = 0; 533 534 spin_lock_bh(&table->tb6_lock); 535 res = fib6_walk(net, w); 536 spin_unlock_bh(&table->tb6_lock); 537 if (res > 0) { 538 cb->args[4] = 1; 539 cb->args[5] = w->root->fn_sernum; 540 } 541 } else { 542 if (cb->args[5] != w->root->fn_sernum) { 543 /* Begin at the root if the tree changed */ 544 cb->args[5] = w->root->fn_sernum; 545 w->state = FWS_INIT; 546 w->node = w->root; 547 w->skip = w->count; 548 } else 549 w->skip = 0; 550 551 spin_lock_bh(&table->tb6_lock); 552 res = fib6_walk_continue(w); 553 spin_unlock_bh(&table->tb6_lock); 554 if (res <= 0) { 555 fib6_walker_unlink(net, w); 556 cb->args[4] = 0; 557 } 558 } 559 560 return res; 561 } 562 563 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 564 { 565 const struct nlmsghdr *nlh = cb->nlh; 566 struct net *net = sock_net(skb->sk); 567 struct rt6_rtnl_dump_arg arg = {}; 568 unsigned int h, s_h; 569 unsigned int e = 0, s_e; 570 struct fib6_walker *w; 571 struct fib6_table *tb; 572 struct hlist_head *head; 573 int res = 0; 574 575 if (cb->strict_check) { 576 int err; 577 578 err = ip_valid_fib_dump_req(net, nlh, &arg.filter, cb); 579 if (err < 0) 580 return err; 581 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 582 struct rtmsg *rtm = nlmsg_data(nlh); 583 584 arg.filter.flags = rtm->rtm_flags & (RTM_F_PREFIX|RTM_F_CLONED); 585 } 586 587 /* fib entries are never clones */ 588 if (arg.filter.flags & RTM_F_CLONED) 589 goto out; 590 591 w = (void *)cb->args[2]; 592 if (!w) { 593 /* New dump: 594 * 595 * 1. hook callback destructor. 596 */ 597 cb->args[3] = (long)cb->done; 598 cb->done = fib6_dump_done; 599 600 /* 601 * 2. allocate and initialize walker. 602 */ 603 w = kzalloc(sizeof(*w), GFP_ATOMIC); 604 if (!w) 605 return -ENOMEM; 606 w->func = fib6_dump_node; 607 cb->args[2] = (long)w; 608 } 609 610 arg.skb = skb; 611 arg.cb = cb; 612 arg.net = net; 613 w->args = &arg; 614 615 if (arg.filter.table_id) { 616 tb = fib6_get_table(net, arg.filter.table_id); 617 if (!tb) { 618 if (arg.filter.dump_all_families) 619 goto out; 620 621 NL_SET_ERR_MSG_MOD(cb->extack, "FIB table does not exist"); 622 return -ENOENT; 623 } 624 625 if (!cb->args[0]) { 626 res = fib6_dump_table(tb, skb, cb); 627 if (!res) 628 cb->args[0] = 1; 629 } 630 goto out; 631 } 632 633 s_h = cb->args[0]; 634 s_e = cb->args[1]; 635 636 rcu_read_lock(); 637 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 638 e = 0; 639 head = &net->ipv6.fib_table_hash[h]; 640 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 641 if (e < s_e) 642 goto next; 643 res = fib6_dump_table(tb, skb, cb); 644 if (res != 0) 645 goto out_unlock; 646 next: 647 e++; 648 } 649 } 650 out_unlock: 651 rcu_read_unlock(); 652 cb->args[1] = e; 653 cb->args[0] = h; 654 out: 655 res = res < 0 ? res : skb->len; 656 if (res <= 0) 657 fib6_dump_end(cb); 658 return res; 659 } 660 661 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val) 662 { 663 if (!f6i) 664 return; 665 666 if (f6i->fib6_metrics == &dst_default_metrics) { 667 struct dst_metrics *p = kzalloc(sizeof(*p), GFP_ATOMIC); 668 669 if (!p) 670 return; 671 672 refcount_set(&p->refcnt, 1); 673 f6i->fib6_metrics = p; 674 } 675 676 f6i->fib6_metrics->metrics[metric - 1] = val; 677 } 678 679 /* 680 * Routing Table 681 * 682 * return the appropriate node for a routing tree "add" operation 683 * by either creating and inserting or by returning an existing 684 * node. 685 */ 686 687 static struct fib6_node *fib6_add_1(struct net *net, 688 struct fib6_table *table, 689 struct fib6_node *root, 690 struct in6_addr *addr, int plen, 691 int offset, int allow_create, 692 int replace_required, 693 struct netlink_ext_ack *extack) 694 { 695 struct fib6_node *fn, *in, *ln; 696 struct fib6_node *pn = NULL; 697 struct rt6key *key; 698 int bit; 699 __be32 dir = 0; 700 701 RT6_TRACE("fib6_add_1\n"); 702 703 /* insert node in tree */ 704 705 fn = root; 706 707 do { 708 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 709 lockdep_is_held(&table->tb6_lock)); 710 key = (struct rt6key *)((u8 *)leaf + offset); 711 712 /* 713 * Prefix match 714 */ 715 if (plen < fn->fn_bit || 716 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 717 if (!allow_create) { 718 if (replace_required) { 719 NL_SET_ERR_MSG(extack, 720 "Can not replace route - no match found"); 721 pr_warn("Can't replace route, no match found\n"); 722 return ERR_PTR(-ENOENT); 723 } 724 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 725 } 726 goto insert_above; 727 } 728 729 /* 730 * Exact match ? 731 */ 732 733 if (plen == fn->fn_bit) { 734 /* clean up an intermediate node */ 735 if (!(fn->fn_flags & RTN_RTINFO)) { 736 RCU_INIT_POINTER(fn->leaf, NULL); 737 fib6_info_release(leaf); 738 /* remove null_entry in the root node */ 739 } else if (fn->fn_flags & RTN_TL_ROOT && 740 rcu_access_pointer(fn->leaf) == 741 net->ipv6.fib6_null_entry) { 742 RCU_INIT_POINTER(fn->leaf, NULL); 743 } 744 745 return fn; 746 } 747 748 /* 749 * We have more bits to go 750 */ 751 752 /* Try to walk down on tree. */ 753 dir = addr_bit_set(addr, fn->fn_bit); 754 pn = fn; 755 fn = dir ? 756 rcu_dereference_protected(fn->right, 757 lockdep_is_held(&table->tb6_lock)) : 758 rcu_dereference_protected(fn->left, 759 lockdep_is_held(&table->tb6_lock)); 760 } while (fn); 761 762 if (!allow_create) { 763 /* We should not create new node because 764 * NLM_F_REPLACE was specified without NLM_F_CREATE 765 * I assume it is safe to require NLM_F_CREATE when 766 * REPLACE flag is used! Later we may want to remove the 767 * check for replace_required, because according 768 * to netlink specification, NLM_F_CREATE 769 * MUST be specified if new route is created. 770 * That would keep IPv6 consistent with IPv4 771 */ 772 if (replace_required) { 773 NL_SET_ERR_MSG(extack, 774 "Can not replace route - no match found"); 775 pr_warn("Can't replace route, no match found\n"); 776 return ERR_PTR(-ENOENT); 777 } 778 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 779 } 780 /* 781 * We walked to the bottom of tree. 782 * Create new leaf node without children. 783 */ 784 785 ln = node_alloc(net); 786 787 if (!ln) 788 return ERR_PTR(-ENOMEM); 789 ln->fn_bit = plen; 790 RCU_INIT_POINTER(ln->parent, pn); 791 792 if (dir) 793 rcu_assign_pointer(pn->right, ln); 794 else 795 rcu_assign_pointer(pn->left, ln); 796 797 return ln; 798 799 800 insert_above: 801 /* 802 * split since we don't have a common prefix anymore or 803 * we have a less significant route. 804 * we've to insert an intermediate node on the list 805 * this new node will point to the one we need to create 806 * and the current 807 */ 808 809 pn = rcu_dereference_protected(fn->parent, 810 lockdep_is_held(&table->tb6_lock)); 811 812 /* find 1st bit in difference between the 2 addrs. 813 814 See comment in __ipv6_addr_diff: bit may be an invalid value, 815 but if it is >= plen, the value is ignored in any case. 816 */ 817 818 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 819 820 /* 821 * (intermediate)[in] 822 * / \ 823 * (new leaf node)[ln] (old node)[fn] 824 */ 825 if (plen > bit) { 826 in = node_alloc(net); 827 ln = node_alloc(net); 828 829 if (!in || !ln) { 830 if (in) 831 node_free_immediate(net, in); 832 if (ln) 833 node_free_immediate(net, ln); 834 return ERR_PTR(-ENOMEM); 835 } 836 837 /* 838 * new intermediate node. 839 * RTN_RTINFO will 840 * be off since that an address that chooses one of 841 * the branches would not match less specific routes 842 * in the other branch 843 */ 844 845 in->fn_bit = bit; 846 847 RCU_INIT_POINTER(in->parent, pn); 848 in->leaf = fn->leaf; 849 fib6_info_hold(rcu_dereference_protected(in->leaf, 850 lockdep_is_held(&table->tb6_lock))); 851 852 /* update parent pointer */ 853 if (dir) 854 rcu_assign_pointer(pn->right, in); 855 else 856 rcu_assign_pointer(pn->left, in); 857 858 ln->fn_bit = plen; 859 860 RCU_INIT_POINTER(ln->parent, in); 861 rcu_assign_pointer(fn->parent, in); 862 863 if (addr_bit_set(addr, bit)) { 864 rcu_assign_pointer(in->right, ln); 865 rcu_assign_pointer(in->left, fn); 866 } else { 867 rcu_assign_pointer(in->left, ln); 868 rcu_assign_pointer(in->right, fn); 869 } 870 } else { /* plen <= bit */ 871 872 /* 873 * (new leaf node)[ln] 874 * / \ 875 * (old node)[fn] NULL 876 */ 877 878 ln = node_alloc(net); 879 880 if (!ln) 881 return ERR_PTR(-ENOMEM); 882 883 ln->fn_bit = plen; 884 885 RCU_INIT_POINTER(ln->parent, pn); 886 887 if (addr_bit_set(&key->addr, plen)) 888 RCU_INIT_POINTER(ln->right, fn); 889 else 890 RCU_INIT_POINTER(ln->left, fn); 891 892 rcu_assign_pointer(fn->parent, ln); 893 894 if (dir) 895 rcu_assign_pointer(pn->right, ln); 896 else 897 rcu_assign_pointer(pn->left, ln); 898 } 899 return ln; 900 } 901 902 static void fib6_drop_pcpu_from(struct fib6_info *f6i, 903 const struct fib6_table *table) 904 { 905 int cpu; 906 907 /* release the reference to this fib entry from 908 * all of its cached pcpu routes 909 */ 910 for_each_possible_cpu(cpu) { 911 struct rt6_info **ppcpu_rt; 912 struct rt6_info *pcpu_rt; 913 914 ppcpu_rt = per_cpu_ptr(f6i->rt6i_pcpu, cpu); 915 pcpu_rt = *ppcpu_rt; 916 if (pcpu_rt) { 917 struct fib6_info *from; 918 919 from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL); 920 fib6_info_release(from); 921 } 922 } 923 } 924 925 static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn, 926 struct net *net) 927 { 928 struct fib6_table *table = rt->fib6_table; 929 930 if (refcount_read(&rt->fib6_ref) != 1) { 931 /* This route is used as dummy address holder in some split 932 * nodes. It is not leaked, but it still holds other resources, 933 * which must be released in time. So, scan ascendant nodes 934 * and replace dummy references to this route with references 935 * to still alive ones. 936 */ 937 while (fn) { 938 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 939 lockdep_is_held(&table->tb6_lock)); 940 struct fib6_info *new_leaf; 941 if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) { 942 new_leaf = fib6_find_prefix(net, table, fn); 943 fib6_info_hold(new_leaf); 944 945 rcu_assign_pointer(fn->leaf, new_leaf); 946 fib6_info_release(rt); 947 } 948 fn = rcu_dereference_protected(fn->parent, 949 lockdep_is_held(&table->tb6_lock)); 950 } 951 952 if (rt->rt6i_pcpu) 953 fib6_drop_pcpu_from(rt, table); 954 } 955 } 956 957 /* 958 * Insert routing information in a node. 959 */ 960 961 static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt, 962 struct nl_info *info, 963 struct netlink_ext_ack *extack) 964 { 965 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 966 lockdep_is_held(&rt->fib6_table->tb6_lock)); 967 struct fib6_info *iter = NULL; 968 struct fib6_info __rcu **ins; 969 struct fib6_info __rcu **fallback_ins = NULL; 970 int replace = (info->nlh && 971 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 972 int add = (!info->nlh || 973 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 974 int found = 0; 975 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 976 u16 nlflags = NLM_F_EXCL; 977 int err; 978 979 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND)) 980 nlflags |= NLM_F_APPEND; 981 982 ins = &fn->leaf; 983 984 for (iter = leaf; iter; 985 iter = rcu_dereference_protected(iter->fib6_next, 986 lockdep_is_held(&rt->fib6_table->tb6_lock))) { 987 /* 988 * Search for duplicates 989 */ 990 991 if (iter->fib6_metric == rt->fib6_metric) { 992 /* 993 * Same priority level 994 */ 995 if (info->nlh && 996 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 997 return -EEXIST; 998 999 nlflags &= ~NLM_F_EXCL; 1000 if (replace) { 1001 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) { 1002 found++; 1003 break; 1004 } 1005 if (rt_can_ecmp) 1006 fallback_ins = fallback_ins ?: ins; 1007 goto next_iter; 1008 } 1009 1010 if (rt6_duplicate_nexthop(iter, rt)) { 1011 if (rt->fib6_nsiblings) 1012 rt->fib6_nsiblings = 0; 1013 if (!(iter->fib6_flags & RTF_EXPIRES)) 1014 return -EEXIST; 1015 if (!(rt->fib6_flags & RTF_EXPIRES)) 1016 fib6_clean_expires(iter); 1017 else 1018 fib6_set_expires(iter, rt->expires); 1019 1020 if (rt->fib6_pmtu) 1021 fib6_metric_set(iter, RTAX_MTU, 1022 rt->fib6_pmtu); 1023 return -EEXIST; 1024 } 1025 /* If we have the same destination and the same metric, 1026 * but not the same gateway, then the route we try to 1027 * add is sibling to this route, increment our counter 1028 * of siblings, and later we will add our route to the 1029 * list. 1030 * Only static routes (which don't have flag 1031 * RTF_EXPIRES) are used for ECMPv6. 1032 * 1033 * To avoid long list, we only had siblings if the 1034 * route have a gateway. 1035 */ 1036 if (rt_can_ecmp && 1037 rt6_qualify_for_ecmp(iter)) 1038 rt->fib6_nsiblings++; 1039 } 1040 1041 if (iter->fib6_metric > rt->fib6_metric) 1042 break; 1043 1044 next_iter: 1045 ins = &iter->fib6_next; 1046 } 1047 1048 if (fallback_ins && !found) { 1049 /* No ECMP-able route found, replace first non-ECMP one */ 1050 ins = fallback_ins; 1051 iter = rcu_dereference_protected(*ins, 1052 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1053 found++; 1054 } 1055 1056 /* Reset round-robin state, if necessary */ 1057 if (ins == &fn->leaf) 1058 fn->rr_ptr = NULL; 1059 1060 /* Link this route to others same route. */ 1061 if (rt->fib6_nsiblings) { 1062 unsigned int fib6_nsiblings; 1063 struct fib6_info *sibling, *temp_sibling; 1064 1065 /* Find the first route that have the same metric */ 1066 sibling = leaf; 1067 while (sibling) { 1068 if (sibling->fib6_metric == rt->fib6_metric && 1069 rt6_qualify_for_ecmp(sibling)) { 1070 list_add_tail(&rt->fib6_siblings, 1071 &sibling->fib6_siblings); 1072 break; 1073 } 1074 sibling = rcu_dereference_protected(sibling->fib6_next, 1075 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1076 } 1077 /* For each sibling in the list, increment the counter of 1078 * siblings. BUG() if counters does not match, list of siblings 1079 * is broken! 1080 */ 1081 fib6_nsiblings = 0; 1082 list_for_each_entry_safe(sibling, temp_sibling, 1083 &rt->fib6_siblings, fib6_siblings) { 1084 sibling->fib6_nsiblings++; 1085 BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings); 1086 fib6_nsiblings++; 1087 } 1088 BUG_ON(fib6_nsiblings != rt->fib6_nsiblings); 1089 rt6_multipath_rebalance(temp_sibling); 1090 } 1091 1092 /* 1093 * insert node 1094 */ 1095 if (!replace) { 1096 if (!add) 1097 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 1098 1099 add: 1100 nlflags |= NLM_F_CREATE; 1101 1102 err = call_fib6_entry_notifiers(info->nl_net, 1103 FIB_EVENT_ENTRY_ADD, 1104 rt, extack); 1105 if (err) 1106 return err; 1107 1108 rcu_assign_pointer(rt->fib6_next, iter); 1109 fib6_info_hold(rt); 1110 rcu_assign_pointer(rt->fib6_node, fn); 1111 rcu_assign_pointer(*ins, rt); 1112 if (!info->skip_notify) 1113 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); 1114 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 1115 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 1121 } else { 1122 int nsiblings; 1123 1124 if (!found) { 1125 if (add) 1126 goto add; 1127 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 1128 return -ENOENT; 1129 } 1130 1131 err = call_fib6_entry_notifiers(info->nl_net, 1132 FIB_EVENT_ENTRY_REPLACE, 1133 rt, extack); 1134 if (err) 1135 return err; 1136 1137 fib6_info_hold(rt); 1138 rcu_assign_pointer(rt->fib6_node, fn); 1139 rt->fib6_next = iter->fib6_next; 1140 rcu_assign_pointer(*ins, rt); 1141 if (!info->skip_notify) 1142 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); 1143 if (!(fn->fn_flags & RTN_RTINFO)) { 1144 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1145 fn->fn_flags |= RTN_RTINFO; 1146 } 1147 nsiblings = iter->fib6_nsiblings; 1148 iter->fib6_node = NULL; 1149 fib6_purge_rt(iter, fn, info->nl_net); 1150 if (rcu_access_pointer(fn->rr_ptr) == iter) 1151 fn->rr_ptr = NULL; 1152 fib6_info_release(iter); 1153 1154 if (nsiblings) { 1155 /* Replacing an ECMP route, remove all siblings */ 1156 ins = &rt->fib6_next; 1157 iter = rcu_dereference_protected(*ins, 1158 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1159 while (iter) { 1160 if (iter->fib6_metric > rt->fib6_metric) 1161 break; 1162 if (rt6_qualify_for_ecmp(iter)) { 1163 *ins = iter->fib6_next; 1164 iter->fib6_node = NULL; 1165 fib6_purge_rt(iter, fn, info->nl_net); 1166 if (rcu_access_pointer(fn->rr_ptr) == iter) 1167 fn->rr_ptr = NULL; 1168 fib6_info_release(iter); 1169 nsiblings--; 1170 info->nl_net->ipv6.rt6_stats->fib_rt_entries--; 1171 } else { 1172 ins = &iter->fib6_next; 1173 } 1174 iter = rcu_dereference_protected(*ins, 1175 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1176 } 1177 WARN_ON(nsiblings != 0); 1178 } 1179 } 1180 1181 return 0; 1182 } 1183 1184 static void fib6_start_gc(struct net *net, struct fib6_info *rt) 1185 { 1186 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 1187 (rt->fib6_flags & RTF_EXPIRES)) 1188 mod_timer(&net->ipv6.ip6_fib_timer, 1189 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1190 } 1191 1192 void fib6_force_start_gc(struct net *net) 1193 { 1194 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 1195 mod_timer(&net->ipv6.ip6_fib_timer, 1196 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1197 } 1198 1199 static void __fib6_update_sernum_upto_root(struct fib6_info *rt, 1200 int sernum) 1201 { 1202 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1203 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1204 1205 /* paired with smp_rmb() in rt6_get_cookie_safe() */ 1206 smp_wmb(); 1207 while (fn) { 1208 fn->fn_sernum = sernum; 1209 fn = rcu_dereference_protected(fn->parent, 1210 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1211 } 1212 } 1213 1214 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt) 1215 { 1216 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net)); 1217 } 1218 1219 /* 1220 * Add routing information to the routing tree. 1221 * <destination addr>/<source addr> 1222 * with source addr info in sub-trees 1223 * Need to own table->tb6_lock 1224 */ 1225 1226 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 1227 struct nl_info *info, struct netlink_ext_ack *extack) 1228 { 1229 struct fib6_table *table = rt->fib6_table; 1230 struct fib6_node *fn, *pn = NULL; 1231 int err = -ENOMEM; 1232 int allow_create = 1; 1233 int replace_required = 0; 1234 int sernum = fib6_new_sernum(info->nl_net); 1235 1236 if (info->nlh) { 1237 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 1238 allow_create = 0; 1239 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 1240 replace_required = 1; 1241 } 1242 if (!allow_create && !replace_required) 1243 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 1244 1245 fn = fib6_add_1(info->nl_net, table, root, 1246 &rt->fib6_dst.addr, rt->fib6_dst.plen, 1247 offsetof(struct fib6_info, fib6_dst), allow_create, 1248 replace_required, extack); 1249 if (IS_ERR(fn)) { 1250 err = PTR_ERR(fn); 1251 fn = NULL; 1252 goto out; 1253 } 1254 1255 pn = fn; 1256 1257 #ifdef CONFIG_IPV6_SUBTREES 1258 if (rt->fib6_src.plen) { 1259 struct fib6_node *sn; 1260 1261 if (!rcu_access_pointer(fn->subtree)) { 1262 struct fib6_node *sfn; 1263 1264 /* 1265 * Create subtree. 1266 * 1267 * fn[main tree] 1268 * | 1269 * sfn[subtree root] 1270 * \ 1271 * sn[new leaf node] 1272 */ 1273 1274 /* Create subtree root node */ 1275 sfn = node_alloc(info->nl_net); 1276 if (!sfn) 1277 goto failure; 1278 1279 fib6_info_hold(info->nl_net->ipv6.fib6_null_entry); 1280 rcu_assign_pointer(sfn->leaf, 1281 info->nl_net->ipv6.fib6_null_entry); 1282 sfn->fn_flags = RTN_ROOT; 1283 1284 /* Now add the first leaf node to new subtree */ 1285 1286 sn = fib6_add_1(info->nl_net, table, sfn, 1287 &rt->fib6_src.addr, rt->fib6_src.plen, 1288 offsetof(struct fib6_info, fib6_src), 1289 allow_create, replace_required, extack); 1290 1291 if (IS_ERR(sn)) { 1292 /* If it is failed, discard just allocated 1293 root, and then (in failure) stale node 1294 in main tree. 1295 */ 1296 node_free_immediate(info->nl_net, sfn); 1297 err = PTR_ERR(sn); 1298 goto failure; 1299 } 1300 1301 /* Now link new subtree to main tree */ 1302 rcu_assign_pointer(sfn->parent, fn); 1303 rcu_assign_pointer(fn->subtree, sfn); 1304 } else { 1305 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn), 1306 &rt->fib6_src.addr, rt->fib6_src.plen, 1307 offsetof(struct fib6_info, fib6_src), 1308 allow_create, replace_required, extack); 1309 1310 if (IS_ERR(sn)) { 1311 err = PTR_ERR(sn); 1312 goto failure; 1313 } 1314 } 1315 1316 if (!rcu_access_pointer(fn->leaf)) { 1317 if (fn->fn_flags & RTN_TL_ROOT) { 1318 /* put back null_entry for root node */ 1319 rcu_assign_pointer(fn->leaf, 1320 info->nl_net->ipv6.fib6_null_entry); 1321 } else { 1322 fib6_info_hold(rt); 1323 rcu_assign_pointer(fn->leaf, rt); 1324 } 1325 } 1326 fn = sn; 1327 } 1328 #endif 1329 1330 err = fib6_add_rt2node(fn, rt, info, extack); 1331 if (!err) { 1332 __fib6_update_sernum_upto_root(rt, sernum); 1333 fib6_start_gc(info->nl_net, rt); 1334 } 1335 1336 out: 1337 if (err) { 1338 #ifdef CONFIG_IPV6_SUBTREES 1339 /* 1340 * If fib6_add_1 has cleared the old leaf pointer in the 1341 * super-tree leaf node we have to find a new one for it. 1342 */ 1343 if (pn != fn) { 1344 struct fib6_info *pn_leaf = 1345 rcu_dereference_protected(pn->leaf, 1346 lockdep_is_held(&table->tb6_lock)); 1347 if (pn_leaf == rt) { 1348 pn_leaf = NULL; 1349 RCU_INIT_POINTER(pn->leaf, NULL); 1350 fib6_info_release(rt); 1351 } 1352 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) { 1353 pn_leaf = fib6_find_prefix(info->nl_net, table, 1354 pn); 1355 #if RT6_DEBUG >= 2 1356 if (!pn_leaf) { 1357 WARN_ON(!pn_leaf); 1358 pn_leaf = 1359 info->nl_net->ipv6.fib6_null_entry; 1360 } 1361 #endif 1362 fib6_info_hold(pn_leaf); 1363 rcu_assign_pointer(pn->leaf, pn_leaf); 1364 } 1365 } 1366 #endif 1367 goto failure; 1368 } 1369 return err; 1370 1371 failure: 1372 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if: 1373 * 1. fn is an intermediate node and we failed to add the new 1374 * route to it in both subtree creation failure and fib6_add_rt2node() 1375 * failure case. 1376 * 2. fn is the root node in the table and we fail to add the first 1377 * default route to it. 1378 */ 1379 if (fn && 1380 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) || 1381 (fn->fn_flags & RTN_TL_ROOT && 1382 !rcu_access_pointer(fn->leaf)))) 1383 fib6_repair_tree(info->nl_net, table, fn); 1384 return err; 1385 } 1386 1387 /* 1388 * Routing tree lookup 1389 * 1390 */ 1391 1392 struct lookup_args { 1393 int offset; /* key offset on fib6_info */ 1394 const struct in6_addr *addr; /* search key */ 1395 }; 1396 1397 static struct fib6_node *fib6_node_lookup_1(struct fib6_node *root, 1398 struct lookup_args *args) 1399 { 1400 struct fib6_node *fn; 1401 __be32 dir; 1402 1403 if (unlikely(args->offset == 0)) 1404 return NULL; 1405 1406 /* 1407 * Descend on a tree 1408 */ 1409 1410 fn = root; 1411 1412 for (;;) { 1413 struct fib6_node *next; 1414 1415 dir = addr_bit_set(args->addr, fn->fn_bit); 1416 1417 next = dir ? rcu_dereference(fn->right) : 1418 rcu_dereference(fn->left); 1419 1420 if (next) { 1421 fn = next; 1422 continue; 1423 } 1424 break; 1425 } 1426 1427 while (fn) { 1428 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1429 1430 if (subtree || fn->fn_flags & RTN_RTINFO) { 1431 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1432 struct rt6key *key; 1433 1434 if (!leaf) 1435 goto backtrack; 1436 1437 key = (struct rt6key *) ((u8 *)leaf + args->offset); 1438 1439 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1440 #ifdef CONFIG_IPV6_SUBTREES 1441 if (subtree) { 1442 struct fib6_node *sfn; 1443 sfn = fib6_node_lookup_1(subtree, 1444 args + 1); 1445 if (!sfn) 1446 goto backtrack; 1447 fn = sfn; 1448 } 1449 #endif 1450 if (fn->fn_flags & RTN_RTINFO) 1451 return fn; 1452 } 1453 } 1454 backtrack: 1455 if (fn->fn_flags & RTN_ROOT) 1456 break; 1457 1458 fn = rcu_dereference(fn->parent); 1459 } 1460 1461 return NULL; 1462 } 1463 1464 /* called with rcu_read_lock() held 1465 */ 1466 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 1467 const struct in6_addr *daddr, 1468 const struct in6_addr *saddr) 1469 { 1470 struct fib6_node *fn; 1471 struct lookup_args args[] = { 1472 { 1473 .offset = offsetof(struct fib6_info, fib6_dst), 1474 .addr = daddr, 1475 }, 1476 #ifdef CONFIG_IPV6_SUBTREES 1477 { 1478 .offset = offsetof(struct fib6_info, fib6_src), 1479 .addr = saddr, 1480 }, 1481 #endif 1482 { 1483 .offset = 0, /* sentinel */ 1484 } 1485 }; 1486 1487 fn = fib6_node_lookup_1(root, daddr ? args : args + 1); 1488 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1489 fn = root; 1490 1491 return fn; 1492 } 1493 1494 /* 1495 * Get node with specified destination prefix (and source prefix, 1496 * if subtrees are used) 1497 * exact_match == true means we try to find fn with exact match of 1498 * the passed in prefix addr 1499 * exact_match == false means we try to find fn with longest prefix 1500 * match of the passed in prefix addr. This is useful for finding fn 1501 * for cached route as it will be stored in the exception table under 1502 * the node with longest prefix length. 1503 */ 1504 1505 1506 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1507 const struct in6_addr *addr, 1508 int plen, int offset, 1509 bool exact_match) 1510 { 1511 struct fib6_node *fn, *prev = NULL; 1512 1513 for (fn = root; fn ; ) { 1514 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1515 struct rt6key *key; 1516 1517 /* This node is being deleted */ 1518 if (!leaf) { 1519 if (plen <= fn->fn_bit) 1520 goto out; 1521 else 1522 goto next; 1523 } 1524 1525 key = (struct rt6key *)((u8 *)leaf + offset); 1526 1527 /* 1528 * Prefix match 1529 */ 1530 if (plen < fn->fn_bit || 1531 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1532 goto out; 1533 1534 if (plen == fn->fn_bit) 1535 return fn; 1536 1537 prev = fn; 1538 1539 next: 1540 /* 1541 * We have more bits to go 1542 */ 1543 if (addr_bit_set(addr, fn->fn_bit)) 1544 fn = rcu_dereference(fn->right); 1545 else 1546 fn = rcu_dereference(fn->left); 1547 } 1548 out: 1549 if (exact_match) 1550 return NULL; 1551 else 1552 return prev; 1553 } 1554 1555 struct fib6_node *fib6_locate(struct fib6_node *root, 1556 const struct in6_addr *daddr, int dst_len, 1557 const struct in6_addr *saddr, int src_len, 1558 bool exact_match) 1559 { 1560 struct fib6_node *fn; 1561 1562 fn = fib6_locate_1(root, daddr, dst_len, 1563 offsetof(struct fib6_info, fib6_dst), 1564 exact_match); 1565 1566 #ifdef CONFIG_IPV6_SUBTREES 1567 if (src_len) { 1568 WARN_ON(saddr == NULL); 1569 if (fn) { 1570 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1571 1572 if (subtree) { 1573 fn = fib6_locate_1(subtree, saddr, src_len, 1574 offsetof(struct fib6_info, fib6_src), 1575 exact_match); 1576 } 1577 } 1578 } 1579 #endif 1580 1581 if (fn && fn->fn_flags & RTN_RTINFO) 1582 return fn; 1583 1584 return NULL; 1585 } 1586 1587 1588 /* 1589 * Deletion 1590 * 1591 */ 1592 1593 static struct fib6_info *fib6_find_prefix(struct net *net, 1594 struct fib6_table *table, 1595 struct fib6_node *fn) 1596 { 1597 struct fib6_node *child_left, *child_right; 1598 1599 if (fn->fn_flags & RTN_ROOT) 1600 return net->ipv6.fib6_null_entry; 1601 1602 while (fn) { 1603 child_left = rcu_dereference_protected(fn->left, 1604 lockdep_is_held(&table->tb6_lock)); 1605 child_right = rcu_dereference_protected(fn->right, 1606 lockdep_is_held(&table->tb6_lock)); 1607 if (child_left) 1608 return rcu_dereference_protected(child_left->leaf, 1609 lockdep_is_held(&table->tb6_lock)); 1610 if (child_right) 1611 return rcu_dereference_protected(child_right->leaf, 1612 lockdep_is_held(&table->tb6_lock)); 1613 1614 fn = FIB6_SUBTREE(fn); 1615 } 1616 return NULL; 1617 } 1618 1619 /* 1620 * Called to trim the tree of intermediate nodes when possible. "fn" 1621 * is the node we want to try and remove. 1622 * Need to own table->tb6_lock 1623 */ 1624 1625 static struct fib6_node *fib6_repair_tree(struct net *net, 1626 struct fib6_table *table, 1627 struct fib6_node *fn) 1628 { 1629 int children; 1630 int nstate; 1631 struct fib6_node *child; 1632 struct fib6_walker *w; 1633 int iter = 0; 1634 1635 /* Set fn->leaf to null_entry for root node. */ 1636 if (fn->fn_flags & RTN_TL_ROOT) { 1637 rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry); 1638 return fn; 1639 } 1640 1641 for (;;) { 1642 struct fib6_node *fn_r = rcu_dereference_protected(fn->right, 1643 lockdep_is_held(&table->tb6_lock)); 1644 struct fib6_node *fn_l = rcu_dereference_protected(fn->left, 1645 lockdep_is_held(&table->tb6_lock)); 1646 struct fib6_node *pn = rcu_dereference_protected(fn->parent, 1647 lockdep_is_held(&table->tb6_lock)); 1648 struct fib6_node *pn_r = rcu_dereference_protected(pn->right, 1649 lockdep_is_held(&table->tb6_lock)); 1650 struct fib6_node *pn_l = rcu_dereference_protected(pn->left, 1651 lockdep_is_held(&table->tb6_lock)); 1652 struct fib6_info *fn_leaf = rcu_dereference_protected(fn->leaf, 1653 lockdep_is_held(&table->tb6_lock)); 1654 struct fib6_info *pn_leaf = rcu_dereference_protected(pn->leaf, 1655 lockdep_is_held(&table->tb6_lock)); 1656 struct fib6_info *new_fn_leaf; 1657 1658 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1659 iter++; 1660 1661 WARN_ON(fn->fn_flags & RTN_RTINFO); 1662 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1663 WARN_ON(fn_leaf); 1664 1665 children = 0; 1666 child = NULL; 1667 if (fn_r) 1668 child = fn_r, children |= 1; 1669 if (fn_l) 1670 child = fn_l, children |= 2; 1671 1672 if (children == 3 || FIB6_SUBTREE(fn) 1673 #ifdef CONFIG_IPV6_SUBTREES 1674 /* Subtree root (i.e. fn) may have one child */ 1675 || (children && fn->fn_flags & RTN_ROOT) 1676 #endif 1677 ) { 1678 new_fn_leaf = fib6_find_prefix(net, table, fn); 1679 #if RT6_DEBUG >= 2 1680 if (!new_fn_leaf) { 1681 WARN_ON(!new_fn_leaf); 1682 new_fn_leaf = net->ipv6.fib6_null_entry; 1683 } 1684 #endif 1685 fib6_info_hold(new_fn_leaf); 1686 rcu_assign_pointer(fn->leaf, new_fn_leaf); 1687 return pn; 1688 } 1689 1690 #ifdef CONFIG_IPV6_SUBTREES 1691 if (FIB6_SUBTREE(pn) == fn) { 1692 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1693 RCU_INIT_POINTER(pn->subtree, NULL); 1694 nstate = FWS_L; 1695 } else { 1696 WARN_ON(fn->fn_flags & RTN_ROOT); 1697 #endif 1698 if (pn_r == fn) 1699 rcu_assign_pointer(pn->right, child); 1700 else if (pn_l == fn) 1701 rcu_assign_pointer(pn->left, child); 1702 #if RT6_DEBUG >= 2 1703 else 1704 WARN_ON(1); 1705 #endif 1706 if (child) 1707 rcu_assign_pointer(child->parent, pn); 1708 nstate = FWS_R; 1709 #ifdef CONFIG_IPV6_SUBTREES 1710 } 1711 #endif 1712 1713 read_lock(&net->ipv6.fib6_walker_lock); 1714 FOR_WALKERS(net, w) { 1715 if (!child) { 1716 if (w->node == fn) { 1717 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1718 w->node = pn; 1719 w->state = nstate; 1720 } 1721 } else { 1722 if (w->node == fn) { 1723 w->node = child; 1724 if (children&2) { 1725 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1726 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1727 } else { 1728 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1729 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1730 } 1731 } 1732 } 1733 } 1734 read_unlock(&net->ipv6.fib6_walker_lock); 1735 1736 node_free(net, fn); 1737 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1738 return pn; 1739 1740 RCU_INIT_POINTER(pn->leaf, NULL); 1741 fib6_info_release(pn_leaf); 1742 fn = pn; 1743 } 1744 } 1745 1746 static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn, 1747 struct fib6_info __rcu **rtp, struct nl_info *info) 1748 { 1749 struct fib6_walker *w; 1750 struct fib6_info *rt = rcu_dereference_protected(*rtp, 1751 lockdep_is_held(&table->tb6_lock)); 1752 struct net *net = info->nl_net; 1753 1754 RT6_TRACE("fib6_del_route\n"); 1755 1756 /* Unlink it */ 1757 *rtp = rt->fib6_next; 1758 rt->fib6_node = NULL; 1759 net->ipv6.rt6_stats->fib_rt_entries--; 1760 net->ipv6.rt6_stats->fib_discarded_routes++; 1761 1762 /* Flush all cached dst in exception table */ 1763 rt6_flush_exceptions(rt); 1764 1765 /* Reset round-robin state, if necessary */ 1766 if (rcu_access_pointer(fn->rr_ptr) == rt) 1767 fn->rr_ptr = NULL; 1768 1769 /* Remove this entry from other siblings */ 1770 if (rt->fib6_nsiblings) { 1771 struct fib6_info *sibling, *next_sibling; 1772 1773 list_for_each_entry_safe(sibling, next_sibling, 1774 &rt->fib6_siblings, fib6_siblings) 1775 sibling->fib6_nsiblings--; 1776 rt->fib6_nsiblings = 0; 1777 list_del_init(&rt->fib6_siblings); 1778 rt6_multipath_rebalance(next_sibling); 1779 } 1780 1781 /* Adjust walkers */ 1782 read_lock(&net->ipv6.fib6_walker_lock); 1783 FOR_WALKERS(net, w) { 1784 if (w->state == FWS_C && w->leaf == rt) { 1785 RT6_TRACE("walker %p adjusted by delroute\n", w); 1786 w->leaf = rcu_dereference_protected(rt->fib6_next, 1787 lockdep_is_held(&table->tb6_lock)); 1788 if (!w->leaf) 1789 w->state = FWS_U; 1790 } 1791 } 1792 read_unlock(&net->ipv6.fib6_walker_lock); 1793 1794 /* If it was last route, call fib6_repair_tree() to: 1795 * 1. For root node, put back null_entry as how the table was created. 1796 * 2. For other nodes, expunge its radix tree node. 1797 */ 1798 if (!rcu_access_pointer(fn->leaf)) { 1799 if (!(fn->fn_flags & RTN_TL_ROOT)) { 1800 fn->fn_flags &= ~RTN_RTINFO; 1801 net->ipv6.rt6_stats->fib_route_nodes--; 1802 } 1803 fn = fib6_repair_tree(net, table, fn); 1804 } 1805 1806 fib6_purge_rt(rt, fn, net); 1807 1808 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL); 1809 if (!info->skip_notify) 1810 inet6_rt_notify(RTM_DELROUTE, rt, info, 0); 1811 fib6_info_release(rt); 1812 } 1813 1814 /* Need to own table->tb6_lock */ 1815 int fib6_del(struct fib6_info *rt, struct nl_info *info) 1816 { 1817 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1818 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1819 struct fib6_table *table = rt->fib6_table; 1820 struct net *net = info->nl_net; 1821 struct fib6_info __rcu **rtp; 1822 struct fib6_info __rcu **rtp_next; 1823 1824 if (!fn || rt == net->ipv6.fib6_null_entry) 1825 return -ENOENT; 1826 1827 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1828 1829 /* 1830 * Walk the leaf entries looking for ourself 1831 */ 1832 1833 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) { 1834 struct fib6_info *cur = rcu_dereference_protected(*rtp, 1835 lockdep_is_held(&table->tb6_lock)); 1836 if (rt == cur) { 1837 fib6_del_route(table, fn, rtp, info); 1838 return 0; 1839 } 1840 rtp_next = &cur->fib6_next; 1841 } 1842 return -ENOENT; 1843 } 1844 1845 /* 1846 * Tree traversal function. 1847 * 1848 * Certainly, it is not interrupt safe. 1849 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1850 * It means, that we can modify tree during walking 1851 * and use this function for garbage collection, clone pruning, 1852 * cleaning tree when a device goes down etc. etc. 1853 * 1854 * It guarantees that every node will be traversed, 1855 * and that it will be traversed only once. 1856 * 1857 * Callback function w->func may return: 1858 * 0 -> continue walking. 1859 * positive value -> walking is suspended (used by tree dumps, 1860 * and probably by gc, if it will be split to several slices) 1861 * negative value -> terminate walking. 1862 * 1863 * The function itself returns: 1864 * 0 -> walk is complete. 1865 * >0 -> walk is incomplete (i.e. suspended) 1866 * <0 -> walk is terminated by an error. 1867 * 1868 * This function is called with tb6_lock held. 1869 */ 1870 1871 static int fib6_walk_continue(struct fib6_walker *w) 1872 { 1873 struct fib6_node *fn, *pn, *left, *right; 1874 1875 /* w->root should always be table->tb6_root */ 1876 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT)); 1877 1878 for (;;) { 1879 fn = w->node; 1880 if (!fn) 1881 return 0; 1882 1883 switch (w->state) { 1884 #ifdef CONFIG_IPV6_SUBTREES 1885 case FWS_S: 1886 if (FIB6_SUBTREE(fn)) { 1887 w->node = FIB6_SUBTREE(fn); 1888 continue; 1889 } 1890 w->state = FWS_L; 1891 #endif 1892 /* fall through */ 1893 case FWS_L: 1894 left = rcu_dereference_protected(fn->left, 1); 1895 if (left) { 1896 w->node = left; 1897 w->state = FWS_INIT; 1898 continue; 1899 } 1900 w->state = FWS_R; 1901 /* fall through */ 1902 case FWS_R: 1903 right = rcu_dereference_protected(fn->right, 1); 1904 if (right) { 1905 w->node = right; 1906 w->state = FWS_INIT; 1907 continue; 1908 } 1909 w->state = FWS_C; 1910 w->leaf = rcu_dereference_protected(fn->leaf, 1); 1911 /* fall through */ 1912 case FWS_C: 1913 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1914 int err; 1915 1916 if (w->skip) { 1917 w->skip--; 1918 goto skip; 1919 } 1920 1921 err = w->func(w); 1922 if (err) 1923 return err; 1924 1925 w->count++; 1926 continue; 1927 } 1928 skip: 1929 w->state = FWS_U; 1930 /* fall through */ 1931 case FWS_U: 1932 if (fn == w->root) 1933 return 0; 1934 pn = rcu_dereference_protected(fn->parent, 1); 1935 left = rcu_dereference_protected(pn->left, 1); 1936 right = rcu_dereference_protected(pn->right, 1); 1937 w->node = pn; 1938 #ifdef CONFIG_IPV6_SUBTREES 1939 if (FIB6_SUBTREE(pn) == fn) { 1940 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1941 w->state = FWS_L; 1942 continue; 1943 } 1944 #endif 1945 if (left == fn) { 1946 w->state = FWS_R; 1947 continue; 1948 } 1949 if (right == fn) { 1950 w->state = FWS_C; 1951 w->leaf = rcu_dereference_protected(w->node->leaf, 1); 1952 continue; 1953 } 1954 #if RT6_DEBUG >= 2 1955 WARN_ON(1); 1956 #endif 1957 } 1958 } 1959 } 1960 1961 static int fib6_walk(struct net *net, struct fib6_walker *w) 1962 { 1963 int res; 1964 1965 w->state = FWS_INIT; 1966 w->node = w->root; 1967 1968 fib6_walker_link(net, w); 1969 res = fib6_walk_continue(w); 1970 if (res <= 0) 1971 fib6_walker_unlink(net, w); 1972 return res; 1973 } 1974 1975 static int fib6_clean_node(struct fib6_walker *w) 1976 { 1977 int res; 1978 struct fib6_info *rt; 1979 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 1980 struct nl_info info = { 1981 .nl_net = c->net, 1982 .skip_notify = c->skip_notify, 1983 }; 1984 1985 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 1986 w->node->fn_sernum != c->sernum) 1987 w->node->fn_sernum = c->sernum; 1988 1989 if (!c->func) { 1990 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 1991 w->leaf = NULL; 1992 return 0; 1993 } 1994 1995 for_each_fib6_walker_rt(w) { 1996 res = c->func(rt, c->arg); 1997 if (res == -1) { 1998 w->leaf = rt; 1999 res = fib6_del(rt, &info); 2000 if (res) { 2001 #if RT6_DEBUG >= 2 2002 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 2003 __func__, rt, 2004 rcu_access_pointer(rt->fib6_node), 2005 res); 2006 #endif 2007 continue; 2008 } 2009 return 0; 2010 } else if (res == -2) { 2011 if (WARN_ON(!rt->fib6_nsiblings)) 2012 continue; 2013 rt = list_last_entry(&rt->fib6_siblings, 2014 struct fib6_info, fib6_siblings); 2015 continue; 2016 } 2017 WARN_ON(res != 0); 2018 } 2019 w->leaf = rt; 2020 return 0; 2021 } 2022 2023 /* 2024 * Convenient frontend to tree walker. 2025 * 2026 * func is called on each route. 2027 * It may return -2 -> skip multipath route. 2028 * -1 -> delete this route. 2029 * 0 -> continue walking 2030 */ 2031 2032 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 2033 int (*func)(struct fib6_info *, void *arg), 2034 int sernum, void *arg, bool skip_notify) 2035 { 2036 struct fib6_cleaner c; 2037 2038 c.w.root = root; 2039 c.w.func = fib6_clean_node; 2040 c.w.count = 0; 2041 c.w.skip = 0; 2042 c.func = func; 2043 c.sernum = sernum; 2044 c.arg = arg; 2045 c.net = net; 2046 c.skip_notify = skip_notify; 2047 2048 fib6_walk(net, &c.w); 2049 } 2050 2051 static void __fib6_clean_all(struct net *net, 2052 int (*func)(struct fib6_info *, void *), 2053 int sernum, void *arg, bool skip_notify) 2054 { 2055 struct fib6_table *table; 2056 struct hlist_head *head; 2057 unsigned int h; 2058 2059 rcu_read_lock(); 2060 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 2061 head = &net->ipv6.fib_table_hash[h]; 2062 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 2063 spin_lock_bh(&table->tb6_lock); 2064 fib6_clean_tree(net, &table->tb6_root, 2065 func, sernum, arg, skip_notify); 2066 spin_unlock_bh(&table->tb6_lock); 2067 } 2068 } 2069 rcu_read_unlock(); 2070 } 2071 2072 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *), 2073 void *arg) 2074 { 2075 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, false); 2076 } 2077 2078 void fib6_clean_all_skip_notify(struct net *net, 2079 int (*func)(struct fib6_info *, void *), 2080 void *arg) 2081 { 2082 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, true); 2083 } 2084 2085 static void fib6_flush_trees(struct net *net) 2086 { 2087 int new_sernum = fib6_new_sernum(net); 2088 2089 __fib6_clean_all(net, NULL, new_sernum, NULL, false); 2090 } 2091 2092 /* 2093 * Garbage collection 2094 */ 2095 2096 static int fib6_age(struct fib6_info *rt, void *arg) 2097 { 2098 struct fib6_gc_args *gc_args = arg; 2099 unsigned long now = jiffies; 2100 2101 /* 2102 * check addrconf expiration here. 2103 * Routes are expired even if they are in use. 2104 */ 2105 2106 if (rt->fib6_flags & RTF_EXPIRES && rt->expires) { 2107 if (time_after(now, rt->expires)) { 2108 RT6_TRACE("expiring %p\n", rt); 2109 return -1; 2110 } 2111 gc_args->more++; 2112 } 2113 2114 /* Also age clones in the exception table. 2115 * Note, that clones are aged out 2116 * only if they are not in use now. 2117 */ 2118 rt6_age_exceptions(rt, gc_args, now); 2119 2120 return 0; 2121 } 2122 2123 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 2124 { 2125 struct fib6_gc_args gc_args; 2126 unsigned long now; 2127 2128 if (force) { 2129 spin_lock_bh(&net->ipv6.fib6_gc_lock); 2130 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) { 2131 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 2132 return; 2133 } 2134 gc_args.timeout = expires ? (int)expires : 2135 net->ipv6.sysctl.ip6_rt_gc_interval; 2136 gc_args.more = 0; 2137 2138 fib6_clean_all(net, fib6_age, &gc_args); 2139 now = jiffies; 2140 net->ipv6.ip6_rt_last_gc = now; 2141 2142 if (gc_args.more) 2143 mod_timer(&net->ipv6.ip6_fib_timer, 2144 round_jiffies(now 2145 + net->ipv6.sysctl.ip6_rt_gc_interval)); 2146 else 2147 del_timer(&net->ipv6.ip6_fib_timer); 2148 spin_unlock_bh(&net->ipv6.fib6_gc_lock); 2149 } 2150 2151 static void fib6_gc_timer_cb(struct timer_list *t) 2152 { 2153 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer); 2154 2155 fib6_run_gc(0, arg, true); 2156 } 2157 2158 static int __net_init fib6_net_init(struct net *net) 2159 { 2160 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 2161 int err; 2162 2163 err = fib6_notifier_init(net); 2164 if (err) 2165 return err; 2166 2167 spin_lock_init(&net->ipv6.fib6_gc_lock); 2168 rwlock_init(&net->ipv6.fib6_walker_lock); 2169 INIT_LIST_HEAD(&net->ipv6.fib6_walkers); 2170 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0); 2171 2172 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 2173 if (!net->ipv6.rt6_stats) 2174 goto out_timer; 2175 2176 /* Avoid false sharing : Use at least a full cache line */ 2177 size = max_t(size_t, size, L1_CACHE_BYTES); 2178 2179 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 2180 if (!net->ipv6.fib_table_hash) 2181 goto out_rt6_stats; 2182 2183 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 2184 GFP_KERNEL); 2185 if (!net->ipv6.fib6_main_tbl) 2186 goto out_fib_table_hash; 2187 2188 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 2189 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf, 2190 net->ipv6.fib6_null_entry); 2191 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 2192 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2193 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 2194 2195 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2196 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 2197 GFP_KERNEL); 2198 if (!net->ipv6.fib6_local_tbl) 2199 goto out_fib6_main_tbl; 2200 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 2201 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf, 2202 net->ipv6.fib6_null_entry); 2203 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 2204 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2205 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 2206 #endif 2207 fib6_tables_init(net); 2208 2209 return 0; 2210 2211 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2212 out_fib6_main_tbl: 2213 kfree(net->ipv6.fib6_main_tbl); 2214 #endif 2215 out_fib_table_hash: 2216 kfree(net->ipv6.fib_table_hash); 2217 out_rt6_stats: 2218 kfree(net->ipv6.rt6_stats); 2219 out_timer: 2220 fib6_notifier_exit(net); 2221 return -ENOMEM; 2222 } 2223 2224 static void fib6_net_exit(struct net *net) 2225 { 2226 unsigned int i; 2227 2228 del_timer_sync(&net->ipv6.ip6_fib_timer); 2229 2230 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) { 2231 struct hlist_head *head = &net->ipv6.fib_table_hash[i]; 2232 struct hlist_node *tmp; 2233 struct fib6_table *tb; 2234 2235 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) { 2236 hlist_del(&tb->tb6_hlist); 2237 fib6_free_table(tb); 2238 } 2239 } 2240 2241 kfree(net->ipv6.fib_table_hash); 2242 kfree(net->ipv6.rt6_stats); 2243 fib6_notifier_exit(net); 2244 } 2245 2246 static struct pernet_operations fib6_net_ops = { 2247 .init = fib6_net_init, 2248 .exit = fib6_net_exit, 2249 }; 2250 2251 int __init fib6_init(void) 2252 { 2253 int ret = -ENOMEM; 2254 2255 fib6_node_kmem = kmem_cache_create("fib6_nodes", 2256 sizeof(struct fib6_node), 2257 0, SLAB_HWCACHE_ALIGN, 2258 NULL); 2259 if (!fib6_node_kmem) 2260 goto out; 2261 2262 ret = register_pernet_subsys(&fib6_net_ops); 2263 if (ret) 2264 goto out_kmem_cache_create; 2265 2266 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL, 2267 inet6_dump_fib, 0); 2268 if (ret) 2269 goto out_unregister_subsys; 2270 2271 __fib6_flush_trees = fib6_flush_trees; 2272 out: 2273 return ret; 2274 2275 out_unregister_subsys: 2276 unregister_pernet_subsys(&fib6_net_ops); 2277 out_kmem_cache_create: 2278 kmem_cache_destroy(fib6_node_kmem); 2279 goto out; 2280 } 2281 2282 void fib6_gc_cleanup(void) 2283 { 2284 unregister_pernet_subsys(&fib6_net_ops); 2285 kmem_cache_destroy(fib6_node_kmem); 2286 } 2287 2288 #ifdef CONFIG_PROC_FS 2289 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 2290 { 2291 struct fib6_info *rt = v; 2292 struct ipv6_route_iter *iter = seq->private; 2293 unsigned int flags = rt->fib6_flags; 2294 const struct net_device *dev; 2295 2296 seq_printf(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen); 2297 2298 #ifdef CONFIG_IPV6_SUBTREES 2299 seq_printf(seq, "%pi6 %02x ", &rt->fib6_src.addr, rt->fib6_src.plen); 2300 #else 2301 seq_puts(seq, "00000000000000000000000000000000 00 "); 2302 #endif 2303 if (rt->fib6_nh.fib_nh_gw_family) { 2304 flags |= RTF_GATEWAY; 2305 seq_printf(seq, "%pi6", &rt->fib6_nh.fib_nh_gw6); 2306 } else { 2307 seq_puts(seq, "00000000000000000000000000000000"); 2308 } 2309 2310 dev = rt->fib6_nh.fib_nh_dev; 2311 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 2312 rt->fib6_metric, refcount_read(&rt->fib6_ref), 0, 2313 flags, dev ? dev->name : ""); 2314 iter->w.leaf = NULL; 2315 return 0; 2316 } 2317 2318 static int ipv6_route_yield(struct fib6_walker *w) 2319 { 2320 struct ipv6_route_iter *iter = w->args; 2321 2322 if (!iter->skip) 2323 return 1; 2324 2325 do { 2326 iter->w.leaf = rcu_dereference_protected( 2327 iter->w.leaf->fib6_next, 2328 lockdep_is_held(&iter->tbl->tb6_lock)); 2329 iter->skip--; 2330 if (!iter->skip && iter->w.leaf) 2331 return 1; 2332 } while (iter->w.leaf); 2333 2334 return 0; 2335 } 2336 2337 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter, 2338 struct net *net) 2339 { 2340 memset(&iter->w, 0, sizeof(iter->w)); 2341 iter->w.func = ipv6_route_yield; 2342 iter->w.root = &iter->tbl->tb6_root; 2343 iter->w.state = FWS_INIT; 2344 iter->w.node = iter->w.root; 2345 iter->w.args = iter; 2346 iter->sernum = iter->w.root->fn_sernum; 2347 INIT_LIST_HEAD(&iter->w.lh); 2348 fib6_walker_link(net, &iter->w); 2349 } 2350 2351 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl, 2352 struct net *net) 2353 { 2354 unsigned int h; 2355 struct hlist_node *node; 2356 2357 if (tbl) { 2358 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1; 2359 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist)); 2360 } else { 2361 h = 0; 2362 node = NULL; 2363 } 2364 2365 while (!node && h < FIB6_TABLE_HASHSZ) { 2366 node = rcu_dereference_bh( 2367 hlist_first_rcu(&net->ipv6.fib_table_hash[h++])); 2368 } 2369 return hlist_entry_safe(node, struct fib6_table, tb6_hlist); 2370 } 2371 2372 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter) 2373 { 2374 if (iter->sernum != iter->w.root->fn_sernum) { 2375 iter->sernum = iter->w.root->fn_sernum; 2376 iter->w.state = FWS_INIT; 2377 iter->w.node = iter->w.root; 2378 WARN_ON(iter->w.skip); 2379 iter->w.skip = iter->w.count; 2380 } 2381 } 2382 2383 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2384 { 2385 int r; 2386 struct fib6_info *n; 2387 struct net *net = seq_file_net(seq); 2388 struct ipv6_route_iter *iter = seq->private; 2389 2390 if (!v) 2391 goto iter_table; 2392 2393 n = rcu_dereference_bh(((struct fib6_info *)v)->fib6_next); 2394 if (n) { 2395 ++*pos; 2396 return n; 2397 } 2398 2399 iter_table: 2400 ipv6_route_check_sernum(iter); 2401 spin_lock_bh(&iter->tbl->tb6_lock); 2402 r = fib6_walk_continue(&iter->w); 2403 spin_unlock_bh(&iter->tbl->tb6_lock); 2404 if (r > 0) { 2405 if (v) 2406 ++*pos; 2407 return iter->w.leaf; 2408 } else if (r < 0) { 2409 fib6_walker_unlink(net, &iter->w); 2410 return NULL; 2411 } 2412 fib6_walker_unlink(net, &iter->w); 2413 2414 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net); 2415 if (!iter->tbl) 2416 return NULL; 2417 2418 ipv6_route_seq_setup_walk(iter, net); 2419 goto iter_table; 2420 } 2421 2422 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos) 2423 __acquires(RCU_BH) 2424 { 2425 struct net *net = seq_file_net(seq); 2426 struct ipv6_route_iter *iter = seq->private; 2427 2428 rcu_read_lock_bh(); 2429 iter->tbl = ipv6_route_seq_next_table(NULL, net); 2430 iter->skip = *pos; 2431 2432 if (iter->tbl) { 2433 ipv6_route_seq_setup_walk(iter, net); 2434 return ipv6_route_seq_next(seq, NULL, pos); 2435 } else { 2436 return NULL; 2437 } 2438 } 2439 2440 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter) 2441 { 2442 struct fib6_walker *w = &iter->w; 2443 return w->node && !(w->state == FWS_U && w->node == w->root); 2444 } 2445 2446 static void ipv6_route_seq_stop(struct seq_file *seq, void *v) 2447 __releases(RCU_BH) 2448 { 2449 struct net *net = seq_file_net(seq); 2450 struct ipv6_route_iter *iter = seq->private; 2451 2452 if (ipv6_route_iter_active(iter)) 2453 fib6_walker_unlink(net, &iter->w); 2454 2455 rcu_read_unlock_bh(); 2456 } 2457 2458 const struct seq_operations ipv6_route_seq_ops = { 2459 .start = ipv6_route_seq_start, 2460 .next = ipv6_route_seq_next, 2461 .stop = ipv6_route_seq_stop, 2462 .show = ipv6_route_seq_show 2463 }; 2464 #endif /* CONFIG_PROC_FS */ 2465