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 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; 174 175 WARN_ON(f6i->fib6_node); 176 177 bucket = rcu_dereference_protected(f6i->rt6i_exception_bucket, 1); 178 if (bucket) { 179 f6i->rt6i_exception_bucket = NULL; 180 kfree(bucket); 181 } 182 183 if (f6i->rt6i_pcpu) { 184 int cpu; 185 186 for_each_possible_cpu(cpu) { 187 struct rt6_info **ppcpu_rt; 188 struct rt6_info *pcpu_rt; 189 190 ppcpu_rt = per_cpu_ptr(f6i->rt6i_pcpu, cpu); 191 pcpu_rt = *ppcpu_rt; 192 if (pcpu_rt) { 193 dst_dev_put(&pcpu_rt->dst); 194 dst_release(&pcpu_rt->dst); 195 *ppcpu_rt = NULL; 196 } 197 } 198 199 free_percpu(f6i->rt6i_pcpu); 200 } 201 202 lwtstate_put(f6i->fib6_nh.nh_lwtstate); 203 204 if (f6i->fib6_nh.nh_dev) 205 dev_put(f6i->fib6_nh.nh_dev); 206 207 ip_fib_metrics_put(f6i->fib6_metrics); 208 209 kfree(f6i); 210 } 211 EXPORT_SYMBOL_GPL(fib6_info_destroy_rcu); 212 213 static struct fib6_node *node_alloc(struct net *net) 214 { 215 struct fib6_node *fn; 216 217 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC); 218 if (fn) 219 net->ipv6.rt6_stats->fib_nodes++; 220 221 return fn; 222 } 223 224 static void node_free_immediate(struct net *net, struct fib6_node *fn) 225 { 226 kmem_cache_free(fib6_node_kmem, fn); 227 net->ipv6.rt6_stats->fib_nodes--; 228 } 229 230 static void node_free_rcu(struct rcu_head *head) 231 { 232 struct fib6_node *fn = container_of(head, struct fib6_node, rcu); 233 234 kmem_cache_free(fib6_node_kmem, fn); 235 } 236 237 static void node_free(struct net *net, struct fib6_node *fn) 238 { 239 call_rcu(&fn->rcu, node_free_rcu); 240 net->ipv6.rt6_stats->fib_nodes--; 241 } 242 243 static void fib6_free_table(struct fib6_table *table) 244 { 245 inetpeer_invalidate_tree(&table->tb6_peers); 246 kfree(table); 247 } 248 249 static void fib6_link_table(struct net *net, struct fib6_table *tb) 250 { 251 unsigned int h; 252 253 /* 254 * Initialize table lock at a single place to give lockdep a key, 255 * tables aren't visible prior to being linked to the list. 256 */ 257 spin_lock_init(&tb->tb6_lock); 258 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1); 259 260 /* 261 * No protection necessary, this is the only list mutatation 262 * operation, tables never disappear once they exist. 263 */ 264 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]); 265 } 266 267 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 268 269 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) 270 { 271 struct fib6_table *table; 272 273 table = kzalloc(sizeof(*table), GFP_ATOMIC); 274 if (table) { 275 table->tb6_id = id; 276 rcu_assign_pointer(table->tb6_root.leaf, 277 net->ipv6.fib6_null_entry); 278 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 279 inet_peer_base_init(&table->tb6_peers); 280 } 281 282 return table; 283 } 284 285 struct fib6_table *fib6_new_table(struct net *net, u32 id) 286 { 287 struct fib6_table *tb; 288 289 if (id == 0) 290 id = RT6_TABLE_MAIN; 291 tb = fib6_get_table(net, id); 292 if (tb) 293 return tb; 294 295 tb = fib6_alloc_table(net, id); 296 if (tb) 297 fib6_link_table(net, tb); 298 299 return tb; 300 } 301 EXPORT_SYMBOL_GPL(fib6_new_table); 302 303 struct fib6_table *fib6_get_table(struct net *net, u32 id) 304 { 305 struct fib6_table *tb; 306 struct hlist_head *head; 307 unsigned int h; 308 309 if (id == 0) 310 id = RT6_TABLE_MAIN; 311 h = id & (FIB6_TABLE_HASHSZ - 1); 312 rcu_read_lock(); 313 head = &net->ipv6.fib_table_hash[h]; 314 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 315 if (tb->tb6_id == id) { 316 rcu_read_unlock(); 317 return tb; 318 } 319 } 320 rcu_read_unlock(); 321 322 return NULL; 323 } 324 EXPORT_SYMBOL_GPL(fib6_get_table); 325 326 static void __net_init fib6_tables_init(struct net *net) 327 { 328 fib6_link_table(net, net->ipv6.fib6_main_tbl); 329 fib6_link_table(net, net->ipv6.fib6_local_tbl); 330 } 331 #else 332 333 struct fib6_table *fib6_new_table(struct net *net, u32 id) 334 { 335 return fib6_get_table(net, id); 336 } 337 338 struct fib6_table *fib6_get_table(struct net *net, u32 id) 339 { 340 return net->ipv6.fib6_main_tbl; 341 } 342 343 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 344 const struct sk_buff *skb, 345 int flags, pol_lookup_t lookup) 346 { 347 struct rt6_info *rt; 348 349 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags); 350 if (rt->dst.error == -EAGAIN) { 351 ip6_rt_put(rt); 352 rt = net->ipv6.ip6_null_entry; 353 dst_hold(&rt->dst); 354 } 355 356 return &rt->dst; 357 } 358 359 /* called with rcu lock held; no reference taken on fib6_info */ 360 struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 361 int flags) 362 { 363 return fib6_table_lookup(net, net->ipv6.fib6_main_tbl, oif, fl6, flags); 364 } 365 366 static void __net_init fib6_tables_init(struct net *net) 367 { 368 fib6_link_table(net, net->ipv6.fib6_main_tbl); 369 } 370 371 #endif 372 373 unsigned int fib6_tables_seq_read(struct net *net) 374 { 375 unsigned int h, fib_seq = 0; 376 377 rcu_read_lock(); 378 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 379 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 380 struct fib6_table *tb; 381 382 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 383 fib_seq += tb->fib_seq; 384 } 385 rcu_read_unlock(); 386 387 return fib_seq; 388 } 389 390 static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net, 391 enum fib_event_type event_type, 392 struct fib6_info *rt) 393 { 394 struct fib6_entry_notifier_info info = { 395 .rt = rt, 396 }; 397 398 return call_fib6_notifier(nb, net, event_type, &info.info); 399 } 400 401 static int call_fib6_entry_notifiers(struct net *net, 402 enum fib_event_type event_type, 403 struct fib6_info *rt, 404 struct netlink_ext_ack *extack) 405 { 406 struct fib6_entry_notifier_info info = { 407 .info.extack = extack, 408 .rt = rt, 409 }; 410 411 rt->fib6_table->fib_seq++; 412 return call_fib6_notifiers(net, event_type, &info.info); 413 } 414 415 struct fib6_dump_arg { 416 struct net *net; 417 struct notifier_block *nb; 418 }; 419 420 static void fib6_rt_dump(struct fib6_info *rt, struct fib6_dump_arg *arg) 421 { 422 if (rt == arg->net->ipv6.fib6_null_entry) 423 return; 424 call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt); 425 } 426 427 static int fib6_node_dump(struct fib6_walker *w) 428 { 429 struct fib6_info *rt; 430 431 for_each_fib6_walker_rt(w) 432 fib6_rt_dump(rt, w->args); 433 w->leaf = NULL; 434 return 0; 435 } 436 437 static void fib6_table_dump(struct net *net, struct fib6_table *tb, 438 struct fib6_walker *w) 439 { 440 w->root = &tb->tb6_root; 441 spin_lock_bh(&tb->tb6_lock); 442 fib6_walk(net, w); 443 spin_unlock_bh(&tb->tb6_lock); 444 } 445 446 /* Called with rcu_read_lock() */ 447 int fib6_tables_dump(struct net *net, struct notifier_block *nb) 448 { 449 struct fib6_dump_arg arg; 450 struct fib6_walker *w; 451 unsigned int h; 452 453 w = kzalloc(sizeof(*w), GFP_ATOMIC); 454 if (!w) 455 return -ENOMEM; 456 457 w->func = fib6_node_dump; 458 arg.net = net; 459 arg.nb = nb; 460 w->args = &arg; 461 462 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 463 struct hlist_head *head = &net->ipv6.fib_table_hash[h]; 464 struct fib6_table *tb; 465 466 hlist_for_each_entry_rcu(tb, head, tb6_hlist) 467 fib6_table_dump(net, tb, w); 468 } 469 470 kfree(w); 471 472 return 0; 473 } 474 475 static int fib6_dump_node(struct fib6_walker *w) 476 { 477 int res; 478 struct fib6_info *rt; 479 480 for_each_fib6_walker_rt(w) { 481 res = rt6_dump_route(rt, w->args); 482 if (res < 0) { 483 /* Frame is full, suspend walking */ 484 w->leaf = rt; 485 return 1; 486 } 487 488 /* Multipath routes are dumped in one route with the 489 * RTA_MULTIPATH attribute. Jump 'rt' to point to the 490 * last sibling of this route (no need to dump the 491 * sibling routes again) 492 */ 493 if (rt->fib6_nsiblings) 494 rt = list_last_entry(&rt->fib6_siblings, 495 struct fib6_info, 496 fib6_siblings); 497 } 498 w->leaf = NULL; 499 return 0; 500 } 501 502 static void fib6_dump_end(struct netlink_callback *cb) 503 { 504 struct net *net = sock_net(cb->skb->sk); 505 struct fib6_walker *w = (void *)cb->args[2]; 506 507 if (w) { 508 if (cb->args[4]) { 509 cb->args[4] = 0; 510 fib6_walker_unlink(net, w); 511 } 512 cb->args[2] = 0; 513 kfree(w); 514 } 515 cb->done = (void *)cb->args[3]; 516 cb->args[1] = 3; 517 } 518 519 static int fib6_dump_done(struct netlink_callback *cb) 520 { 521 fib6_dump_end(cb); 522 return cb->done ? cb->done(cb) : 0; 523 } 524 525 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb, 526 struct netlink_callback *cb) 527 { 528 struct net *net = sock_net(skb->sk); 529 struct fib6_walker *w; 530 int res; 531 532 w = (void *)cb->args[2]; 533 w->root = &table->tb6_root; 534 535 if (cb->args[4] == 0) { 536 w->count = 0; 537 w->skip = 0; 538 539 spin_lock_bh(&table->tb6_lock); 540 res = fib6_walk(net, w); 541 spin_unlock_bh(&table->tb6_lock); 542 if (res > 0) { 543 cb->args[4] = 1; 544 cb->args[5] = w->root->fn_sernum; 545 } 546 } else { 547 if (cb->args[5] != w->root->fn_sernum) { 548 /* Begin at the root if the tree changed */ 549 cb->args[5] = w->root->fn_sernum; 550 w->state = FWS_INIT; 551 w->node = w->root; 552 w->skip = w->count; 553 } else 554 w->skip = 0; 555 556 spin_lock_bh(&table->tb6_lock); 557 res = fib6_walk_continue(w); 558 spin_unlock_bh(&table->tb6_lock); 559 if (res <= 0) { 560 fib6_walker_unlink(net, w); 561 cb->args[4] = 0; 562 } 563 } 564 565 return res; 566 } 567 568 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 569 { 570 const struct nlmsghdr *nlh = cb->nlh; 571 struct net *net = sock_net(skb->sk); 572 struct rt6_rtnl_dump_arg arg = {}; 573 unsigned int h, s_h; 574 unsigned int e = 0, s_e; 575 struct fib6_walker *w; 576 struct fib6_table *tb; 577 struct hlist_head *head; 578 int res = 0; 579 580 if (cb->strict_check) { 581 int err; 582 583 err = ip_valid_fib_dump_req(net, nlh, &arg.filter, cb); 584 if (err < 0) 585 return err; 586 } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { 587 struct rtmsg *rtm = nlmsg_data(nlh); 588 589 arg.filter.flags = rtm->rtm_flags & (RTM_F_PREFIX|RTM_F_CLONED); 590 } 591 592 /* fib entries are never clones */ 593 if (arg.filter.flags & RTM_F_CLONED) 594 return skb->len; 595 596 w = (void *)cb->args[2]; 597 if (!w) { 598 /* New dump: 599 * 600 * 1. hook callback destructor. 601 */ 602 cb->args[3] = (long)cb->done; 603 cb->done = fib6_dump_done; 604 605 /* 606 * 2. allocate and initialize walker. 607 */ 608 w = kzalloc(sizeof(*w), GFP_ATOMIC); 609 if (!w) 610 return -ENOMEM; 611 w->func = fib6_dump_node; 612 cb->args[2] = (long)w; 613 } 614 615 arg.skb = skb; 616 arg.cb = cb; 617 arg.net = net; 618 w->args = &arg; 619 620 if (arg.filter.table_id) { 621 tb = fib6_get_table(net, arg.filter.table_id); 622 if (!tb) { 623 if (arg.filter.dump_all_families) 624 return skb->len; 625 626 NL_SET_ERR_MSG_MOD(cb->extack, "FIB table does not exist"); 627 return -ENOENT; 628 } 629 630 res = fib6_dump_table(tb, skb, cb); 631 goto out; 632 } 633 634 s_h = cb->args[0]; 635 s_e = cb->args[1]; 636 637 rcu_read_lock(); 638 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) { 639 e = 0; 640 head = &net->ipv6.fib_table_hash[h]; 641 hlist_for_each_entry_rcu(tb, head, tb6_hlist) { 642 if (e < s_e) 643 goto next; 644 res = fib6_dump_table(tb, skb, cb); 645 if (res != 0) 646 goto out_unlock; 647 next: 648 e++; 649 } 650 } 651 out_unlock: 652 rcu_read_unlock(); 653 cb->args[1] = e; 654 cb->args[0] = h; 655 out: 656 res = res < 0 ? res : skb->len; 657 if (res <= 0) 658 fib6_dump_end(cb); 659 return res; 660 } 661 662 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val) 663 { 664 if (!f6i) 665 return; 666 667 if (f6i->fib6_metrics == &dst_default_metrics) { 668 struct dst_metrics *p = kzalloc(sizeof(*p), GFP_ATOMIC); 669 670 if (!p) 671 return; 672 673 refcount_set(&p->refcnt, 1); 674 f6i->fib6_metrics = p; 675 } 676 677 f6i->fib6_metrics->metrics[metric - 1] = val; 678 } 679 680 /* 681 * Routing Table 682 * 683 * return the appropriate node for a routing tree "add" operation 684 * by either creating and inserting or by returning an existing 685 * node. 686 */ 687 688 static struct fib6_node *fib6_add_1(struct net *net, 689 struct fib6_table *table, 690 struct fib6_node *root, 691 struct in6_addr *addr, int plen, 692 int offset, int allow_create, 693 int replace_required, 694 struct netlink_ext_ack *extack) 695 { 696 struct fib6_node *fn, *in, *ln; 697 struct fib6_node *pn = NULL; 698 struct rt6key *key; 699 int bit; 700 __be32 dir = 0; 701 702 RT6_TRACE("fib6_add_1\n"); 703 704 /* insert node in tree */ 705 706 fn = root; 707 708 do { 709 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 710 lockdep_is_held(&table->tb6_lock)); 711 key = (struct rt6key *)((u8 *)leaf + offset); 712 713 /* 714 * Prefix match 715 */ 716 if (plen < fn->fn_bit || 717 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) { 718 if (!allow_create) { 719 if (replace_required) { 720 NL_SET_ERR_MSG(extack, 721 "Can not replace route - no match found"); 722 pr_warn("Can't replace route, no match found\n"); 723 return ERR_PTR(-ENOENT); 724 } 725 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 726 } 727 goto insert_above; 728 } 729 730 /* 731 * Exact match ? 732 */ 733 734 if (plen == fn->fn_bit) { 735 /* clean up an intermediate node */ 736 if (!(fn->fn_flags & RTN_RTINFO)) { 737 RCU_INIT_POINTER(fn->leaf, NULL); 738 fib6_info_release(leaf); 739 /* remove null_entry in the root node */ 740 } else if (fn->fn_flags & RTN_TL_ROOT && 741 rcu_access_pointer(fn->leaf) == 742 net->ipv6.fib6_null_entry) { 743 RCU_INIT_POINTER(fn->leaf, NULL); 744 } 745 746 return fn; 747 } 748 749 /* 750 * We have more bits to go 751 */ 752 753 /* Try to walk down on tree. */ 754 dir = addr_bit_set(addr, fn->fn_bit); 755 pn = fn; 756 fn = dir ? 757 rcu_dereference_protected(fn->right, 758 lockdep_is_held(&table->tb6_lock)) : 759 rcu_dereference_protected(fn->left, 760 lockdep_is_held(&table->tb6_lock)); 761 } while (fn); 762 763 if (!allow_create) { 764 /* We should not create new node because 765 * NLM_F_REPLACE was specified without NLM_F_CREATE 766 * I assume it is safe to require NLM_F_CREATE when 767 * REPLACE flag is used! Later we may want to remove the 768 * check for replace_required, because according 769 * to netlink specification, NLM_F_CREATE 770 * MUST be specified if new route is created. 771 * That would keep IPv6 consistent with IPv4 772 */ 773 if (replace_required) { 774 NL_SET_ERR_MSG(extack, 775 "Can not replace route - no match found"); 776 pr_warn("Can't replace route, no match found\n"); 777 return ERR_PTR(-ENOENT); 778 } 779 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 780 } 781 /* 782 * We walked to the bottom of tree. 783 * Create new leaf node without children. 784 */ 785 786 ln = node_alloc(net); 787 788 if (!ln) 789 return ERR_PTR(-ENOMEM); 790 ln->fn_bit = plen; 791 RCU_INIT_POINTER(ln->parent, pn); 792 793 if (dir) 794 rcu_assign_pointer(pn->right, ln); 795 else 796 rcu_assign_pointer(pn->left, ln); 797 798 return ln; 799 800 801 insert_above: 802 /* 803 * split since we don't have a common prefix anymore or 804 * we have a less significant route. 805 * we've to insert an intermediate node on the list 806 * this new node will point to the one we need to create 807 * and the current 808 */ 809 810 pn = rcu_dereference_protected(fn->parent, 811 lockdep_is_held(&table->tb6_lock)); 812 813 /* find 1st bit in difference between the 2 addrs. 814 815 See comment in __ipv6_addr_diff: bit may be an invalid value, 816 but if it is >= plen, the value is ignored in any case. 817 */ 818 819 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr)); 820 821 /* 822 * (intermediate)[in] 823 * / \ 824 * (new leaf node)[ln] (old node)[fn] 825 */ 826 if (plen > bit) { 827 in = node_alloc(net); 828 ln = node_alloc(net); 829 830 if (!in || !ln) { 831 if (in) 832 node_free_immediate(net, in); 833 if (ln) 834 node_free_immediate(net, ln); 835 return ERR_PTR(-ENOMEM); 836 } 837 838 /* 839 * new intermediate node. 840 * RTN_RTINFO will 841 * be off since that an address that chooses one of 842 * the branches would not match less specific routes 843 * in the other branch 844 */ 845 846 in->fn_bit = bit; 847 848 RCU_INIT_POINTER(in->parent, pn); 849 in->leaf = fn->leaf; 850 atomic_inc(&rcu_dereference_protected(in->leaf, 851 lockdep_is_held(&table->tb6_lock))->fib6_ref); 852 853 /* update parent pointer */ 854 if (dir) 855 rcu_assign_pointer(pn->right, in); 856 else 857 rcu_assign_pointer(pn->left, in); 858 859 ln->fn_bit = plen; 860 861 RCU_INIT_POINTER(ln->parent, in); 862 rcu_assign_pointer(fn->parent, in); 863 864 if (addr_bit_set(addr, bit)) { 865 rcu_assign_pointer(in->right, ln); 866 rcu_assign_pointer(in->left, fn); 867 } else { 868 rcu_assign_pointer(in->left, ln); 869 rcu_assign_pointer(in->right, fn); 870 } 871 } else { /* plen <= bit */ 872 873 /* 874 * (new leaf node)[ln] 875 * / \ 876 * (old node)[fn] NULL 877 */ 878 879 ln = node_alloc(net); 880 881 if (!ln) 882 return ERR_PTR(-ENOMEM); 883 884 ln->fn_bit = plen; 885 886 RCU_INIT_POINTER(ln->parent, pn); 887 888 if (addr_bit_set(&key->addr, plen)) 889 RCU_INIT_POINTER(ln->right, fn); 890 else 891 RCU_INIT_POINTER(ln->left, fn); 892 893 rcu_assign_pointer(fn->parent, ln); 894 895 if (dir) 896 rcu_assign_pointer(pn->right, ln); 897 else 898 rcu_assign_pointer(pn->left, ln); 899 } 900 return ln; 901 } 902 903 static void fib6_drop_pcpu_from(struct fib6_info *f6i, 904 const struct fib6_table *table) 905 { 906 int cpu; 907 908 /* release the reference to this fib entry from 909 * all of its cached pcpu routes 910 */ 911 for_each_possible_cpu(cpu) { 912 struct rt6_info **ppcpu_rt; 913 struct rt6_info *pcpu_rt; 914 915 ppcpu_rt = per_cpu_ptr(f6i->rt6i_pcpu, cpu); 916 pcpu_rt = *ppcpu_rt; 917 if (pcpu_rt) { 918 struct fib6_info *from; 919 920 from = rcu_dereference_protected(pcpu_rt->from, 921 lockdep_is_held(&table->tb6_lock)); 922 rcu_assign_pointer(pcpu_rt->from, NULL); 923 fib6_info_release(from); 924 } 925 } 926 } 927 928 static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn, 929 struct net *net) 930 { 931 struct fib6_table *table = rt->fib6_table; 932 933 if (atomic_read(&rt->fib6_ref) != 1) { 934 /* This route is used as dummy address holder in some split 935 * nodes. It is not leaked, but it still holds other resources, 936 * which must be released in time. So, scan ascendant nodes 937 * and replace dummy references to this route with references 938 * to still alive ones. 939 */ 940 while (fn) { 941 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 942 lockdep_is_held(&table->tb6_lock)); 943 struct fib6_info *new_leaf; 944 if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) { 945 new_leaf = fib6_find_prefix(net, table, fn); 946 atomic_inc(&new_leaf->fib6_ref); 947 948 rcu_assign_pointer(fn->leaf, new_leaf); 949 fib6_info_release(rt); 950 } 951 fn = rcu_dereference_protected(fn->parent, 952 lockdep_is_held(&table->tb6_lock)); 953 } 954 955 if (rt->rt6i_pcpu) 956 fib6_drop_pcpu_from(rt, table); 957 } 958 } 959 960 /* 961 * Insert routing information in a node. 962 */ 963 964 static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt, 965 struct nl_info *info, 966 struct netlink_ext_ack *extack) 967 { 968 struct fib6_info *leaf = rcu_dereference_protected(fn->leaf, 969 lockdep_is_held(&rt->fib6_table->tb6_lock)); 970 struct fib6_info *iter = NULL; 971 struct fib6_info __rcu **ins; 972 struct fib6_info __rcu **fallback_ins = NULL; 973 int replace = (info->nlh && 974 (info->nlh->nlmsg_flags & NLM_F_REPLACE)); 975 int add = (!info->nlh || 976 (info->nlh->nlmsg_flags & NLM_F_CREATE)); 977 int found = 0; 978 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 979 u16 nlflags = NLM_F_EXCL; 980 int err; 981 982 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND)) 983 nlflags |= NLM_F_APPEND; 984 985 ins = &fn->leaf; 986 987 for (iter = leaf; iter; 988 iter = rcu_dereference_protected(iter->fib6_next, 989 lockdep_is_held(&rt->fib6_table->tb6_lock))) { 990 /* 991 * Search for duplicates 992 */ 993 994 if (iter->fib6_metric == rt->fib6_metric) { 995 /* 996 * Same priority level 997 */ 998 if (info->nlh && 999 (info->nlh->nlmsg_flags & NLM_F_EXCL)) 1000 return -EEXIST; 1001 1002 nlflags &= ~NLM_F_EXCL; 1003 if (replace) { 1004 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) { 1005 found++; 1006 break; 1007 } 1008 if (rt_can_ecmp) 1009 fallback_ins = fallback_ins ?: ins; 1010 goto next_iter; 1011 } 1012 1013 if (rt6_duplicate_nexthop(iter, rt)) { 1014 if (rt->fib6_nsiblings) 1015 rt->fib6_nsiblings = 0; 1016 if (!(iter->fib6_flags & RTF_EXPIRES)) 1017 return -EEXIST; 1018 if (!(rt->fib6_flags & RTF_EXPIRES)) 1019 fib6_clean_expires(iter); 1020 else 1021 fib6_set_expires(iter, rt->expires); 1022 1023 if (rt->fib6_pmtu) 1024 fib6_metric_set(iter, RTAX_MTU, 1025 rt->fib6_pmtu); 1026 return -EEXIST; 1027 } 1028 /* If we have the same destination and the same metric, 1029 * but not the same gateway, then the route we try to 1030 * add is sibling to this route, increment our counter 1031 * of siblings, and later we will add our route to the 1032 * list. 1033 * Only static routes (which don't have flag 1034 * RTF_EXPIRES) are used for ECMPv6. 1035 * 1036 * To avoid long list, we only had siblings if the 1037 * route have a gateway. 1038 */ 1039 if (rt_can_ecmp && 1040 rt6_qualify_for_ecmp(iter)) 1041 rt->fib6_nsiblings++; 1042 } 1043 1044 if (iter->fib6_metric > rt->fib6_metric) 1045 break; 1046 1047 next_iter: 1048 ins = &iter->fib6_next; 1049 } 1050 1051 if (fallback_ins && !found) { 1052 /* No ECMP-able route found, replace first non-ECMP one */ 1053 ins = fallback_ins; 1054 iter = rcu_dereference_protected(*ins, 1055 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1056 found++; 1057 } 1058 1059 /* Reset round-robin state, if necessary */ 1060 if (ins == &fn->leaf) 1061 fn->rr_ptr = NULL; 1062 1063 /* Link this route to others same route. */ 1064 if (rt->fib6_nsiblings) { 1065 unsigned int fib6_nsiblings; 1066 struct fib6_info *sibling, *temp_sibling; 1067 1068 /* Find the first route that have the same metric */ 1069 sibling = leaf; 1070 while (sibling) { 1071 if (sibling->fib6_metric == rt->fib6_metric && 1072 rt6_qualify_for_ecmp(sibling)) { 1073 list_add_tail(&rt->fib6_siblings, 1074 &sibling->fib6_siblings); 1075 break; 1076 } 1077 sibling = rcu_dereference_protected(sibling->fib6_next, 1078 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1079 } 1080 /* For each sibling in the list, increment the counter of 1081 * siblings. BUG() if counters does not match, list of siblings 1082 * is broken! 1083 */ 1084 fib6_nsiblings = 0; 1085 list_for_each_entry_safe(sibling, temp_sibling, 1086 &rt->fib6_siblings, fib6_siblings) { 1087 sibling->fib6_nsiblings++; 1088 BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings); 1089 fib6_nsiblings++; 1090 } 1091 BUG_ON(fib6_nsiblings != rt->fib6_nsiblings); 1092 rt6_multipath_rebalance(temp_sibling); 1093 } 1094 1095 /* 1096 * insert node 1097 */ 1098 if (!replace) { 1099 if (!add) 1100 pr_warn("NLM_F_CREATE should be set when creating new route\n"); 1101 1102 add: 1103 nlflags |= NLM_F_CREATE; 1104 1105 err = call_fib6_entry_notifiers(info->nl_net, 1106 FIB_EVENT_ENTRY_ADD, 1107 rt, extack); 1108 if (err) 1109 return err; 1110 1111 rcu_assign_pointer(rt->fib6_next, iter); 1112 atomic_inc(&rt->fib6_ref); 1113 rcu_assign_pointer(rt->fib6_node, fn); 1114 rcu_assign_pointer(*ins, rt); 1115 if (!info->skip_notify) 1116 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); 1117 info->nl_net->ipv6.rt6_stats->fib_rt_entries++; 1118 1119 if (!(fn->fn_flags & RTN_RTINFO)) { 1120 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1121 fn->fn_flags |= RTN_RTINFO; 1122 } 1123 1124 } else { 1125 int nsiblings; 1126 1127 if (!found) { 1128 if (add) 1129 goto add; 1130 pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); 1131 return -ENOENT; 1132 } 1133 1134 err = call_fib6_entry_notifiers(info->nl_net, 1135 FIB_EVENT_ENTRY_REPLACE, 1136 rt, extack); 1137 if (err) 1138 return err; 1139 1140 atomic_inc(&rt->fib6_ref); 1141 rcu_assign_pointer(rt->fib6_node, fn); 1142 rt->fib6_next = iter->fib6_next; 1143 rcu_assign_pointer(*ins, rt); 1144 if (!info->skip_notify) 1145 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); 1146 if (!(fn->fn_flags & RTN_RTINFO)) { 1147 info->nl_net->ipv6.rt6_stats->fib_route_nodes++; 1148 fn->fn_flags |= RTN_RTINFO; 1149 } 1150 nsiblings = iter->fib6_nsiblings; 1151 iter->fib6_node = NULL; 1152 fib6_purge_rt(iter, fn, info->nl_net); 1153 if (rcu_access_pointer(fn->rr_ptr) == iter) 1154 fn->rr_ptr = NULL; 1155 fib6_info_release(iter); 1156 1157 if (nsiblings) { 1158 /* Replacing an ECMP route, remove all siblings */ 1159 ins = &rt->fib6_next; 1160 iter = rcu_dereference_protected(*ins, 1161 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1162 while (iter) { 1163 if (iter->fib6_metric > rt->fib6_metric) 1164 break; 1165 if (rt6_qualify_for_ecmp(iter)) { 1166 *ins = iter->fib6_next; 1167 iter->fib6_node = NULL; 1168 fib6_purge_rt(iter, fn, info->nl_net); 1169 if (rcu_access_pointer(fn->rr_ptr) == iter) 1170 fn->rr_ptr = NULL; 1171 fib6_info_release(iter); 1172 nsiblings--; 1173 info->nl_net->ipv6.rt6_stats->fib_rt_entries--; 1174 } else { 1175 ins = &iter->fib6_next; 1176 } 1177 iter = rcu_dereference_protected(*ins, 1178 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1179 } 1180 WARN_ON(nsiblings != 0); 1181 } 1182 } 1183 1184 return 0; 1185 } 1186 1187 static void fib6_start_gc(struct net *net, struct fib6_info *rt) 1188 { 1189 if (!timer_pending(&net->ipv6.ip6_fib_timer) && 1190 (rt->fib6_flags & RTF_EXPIRES)) 1191 mod_timer(&net->ipv6.ip6_fib_timer, 1192 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1193 } 1194 1195 void fib6_force_start_gc(struct net *net) 1196 { 1197 if (!timer_pending(&net->ipv6.ip6_fib_timer)) 1198 mod_timer(&net->ipv6.ip6_fib_timer, 1199 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval); 1200 } 1201 1202 static void __fib6_update_sernum_upto_root(struct fib6_info *rt, 1203 int sernum) 1204 { 1205 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1206 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1207 1208 /* paired with smp_rmb() in rt6_get_cookie_safe() */ 1209 smp_wmb(); 1210 while (fn) { 1211 fn->fn_sernum = sernum; 1212 fn = rcu_dereference_protected(fn->parent, 1213 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1214 } 1215 } 1216 1217 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt) 1218 { 1219 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net)); 1220 } 1221 1222 /* 1223 * Add routing information to the routing tree. 1224 * <destination addr>/<source addr> 1225 * with source addr info in sub-trees 1226 * Need to own table->tb6_lock 1227 */ 1228 1229 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 1230 struct nl_info *info, struct netlink_ext_ack *extack) 1231 { 1232 struct fib6_table *table = rt->fib6_table; 1233 struct fib6_node *fn, *pn = NULL; 1234 int err = -ENOMEM; 1235 int allow_create = 1; 1236 int replace_required = 0; 1237 int sernum = fib6_new_sernum(info->nl_net); 1238 1239 if (info->nlh) { 1240 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE)) 1241 allow_create = 0; 1242 if (info->nlh->nlmsg_flags & NLM_F_REPLACE) 1243 replace_required = 1; 1244 } 1245 if (!allow_create && !replace_required) 1246 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n"); 1247 1248 fn = fib6_add_1(info->nl_net, table, root, 1249 &rt->fib6_dst.addr, rt->fib6_dst.plen, 1250 offsetof(struct fib6_info, fib6_dst), allow_create, 1251 replace_required, extack); 1252 if (IS_ERR(fn)) { 1253 err = PTR_ERR(fn); 1254 fn = NULL; 1255 goto out; 1256 } 1257 1258 pn = fn; 1259 1260 #ifdef CONFIG_IPV6_SUBTREES 1261 if (rt->fib6_src.plen) { 1262 struct fib6_node *sn; 1263 1264 if (!rcu_access_pointer(fn->subtree)) { 1265 struct fib6_node *sfn; 1266 1267 /* 1268 * Create subtree. 1269 * 1270 * fn[main tree] 1271 * | 1272 * sfn[subtree root] 1273 * \ 1274 * sn[new leaf node] 1275 */ 1276 1277 /* Create subtree root node */ 1278 sfn = node_alloc(info->nl_net); 1279 if (!sfn) 1280 goto failure; 1281 1282 atomic_inc(&info->nl_net->ipv6.fib6_null_entry->fib6_ref); 1283 rcu_assign_pointer(sfn->leaf, 1284 info->nl_net->ipv6.fib6_null_entry); 1285 sfn->fn_flags = RTN_ROOT; 1286 1287 /* Now add the first leaf node to new subtree */ 1288 1289 sn = fib6_add_1(info->nl_net, table, sfn, 1290 &rt->fib6_src.addr, rt->fib6_src.plen, 1291 offsetof(struct fib6_info, fib6_src), 1292 allow_create, replace_required, extack); 1293 1294 if (IS_ERR(sn)) { 1295 /* If it is failed, discard just allocated 1296 root, and then (in failure) stale node 1297 in main tree. 1298 */ 1299 node_free_immediate(info->nl_net, sfn); 1300 err = PTR_ERR(sn); 1301 goto failure; 1302 } 1303 1304 /* Now link new subtree to main tree */ 1305 rcu_assign_pointer(sfn->parent, fn); 1306 rcu_assign_pointer(fn->subtree, sfn); 1307 } else { 1308 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn), 1309 &rt->fib6_src.addr, rt->fib6_src.plen, 1310 offsetof(struct fib6_info, fib6_src), 1311 allow_create, replace_required, extack); 1312 1313 if (IS_ERR(sn)) { 1314 err = PTR_ERR(sn); 1315 goto failure; 1316 } 1317 } 1318 1319 if (!rcu_access_pointer(fn->leaf)) { 1320 if (fn->fn_flags & RTN_TL_ROOT) { 1321 /* put back null_entry for root node */ 1322 rcu_assign_pointer(fn->leaf, 1323 info->nl_net->ipv6.fib6_null_entry); 1324 } else { 1325 atomic_inc(&rt->fib6_ref); 1326 rcu_assign_pointer(fn->leaf, rt); 1327 } 1328 } 1329 fn = sn; 1330 } 1331 #endif 1332 1333 err = fib6_add_rt2node(fn, rt, info, extack); 1334 if (!err) { 1335 __fib6_update_sernum_upto_root(rt, sernum); 1336 fib6_start_gc(info->nl_net, rt); 1337 } 1338 1339 out: 1340 if (err) { 1341 #ifdef CONFIG_IPV6_SUBTREES 1342 /* 1343 * If fib6_add_1 has cleared the old leaf pointer in the 1344 * super-tree leaf node we have to find a new one for it. 1345 */ 1346 if (pn != fn) { 1347 struct fib6_info *pn_leaf = 1348 rcu_dereference_protected(pn->leaf, 1349 lockdep_is_held(&table->tb6_lock)); 1350 if (pn_leaf == rt) { 1351 pn_leaf = NULL; 1352 RCU_INIT_POINTER(pn->leaf, NULL); 1353 fib6_info_release(rt); 1354 } 1355 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) { 1356 pn_leaf = fib6_find_prefix(info->nl_net, table, 1357 pn); 1358 #if RT6_DEBUG >= 2 1359 if (!pn_leaf) { 1360 WARN_ON(!pn_leaf); 1361 pn_leaf = 1362 info->nl_net->ipv6.fib6_null_entry; 1363 } 1364 #endif 1365 fib6_info_hold(pn_leaf); 1366 rcu_assign_pointer(pn->leaf, pn_leaf); 1367 } 1368 } 1369 #endif 1370 goto failure; 1371 } 1372 return err; 1373 1374 failure: 1375 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if: 1376 * 1. fn is an intermediate node and we failed to add the new 1377 * route to it in both subtree creation failure and fib6_add_rt2node() 1378 * failure case. 1379 * 2. fn is the root node in the table and we fail to add the first 1380 * default route to it. 1381 */ 1382 if (fn && 1383 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) || 1384 (fn->fn_flags & RTN_TL_ROOT && 1385 !rcu_access_pointer(fn->leaf)))) 1386 fib6_repair_tree(info->nl_net, table, fn); 1387 return err; 1388 } 1389 1390 /* 1391 * Routing tree lookup 1392 * 1393 */ 1394 1395 struct lookup_args { 1396 int offset; /* key offset on fib6_info */ 1397 const struct in6_addr *addr; /* search key */ 1398 }; 1399 1400 static struct fib6_node *fib6_node_lookup_1(struct fib6_node *root, 1401 struct lookup_args *args) 1402 { 1403 struct fib6_node *fn; 1404 __be32 dir; 1405 1406 if (unlikely(args->offset == 0)) 1407 return NULL; 1408 1409 /* 1410 * Descend on a tree 1411 */ 1412 1413 fn = root; 1414 1415 for (;;) { 1416 struct fib6_node *next; 1417 1418 dir = addr_bit_set(args->addr, fn->fn_bit); 1419 1420 next = dir ? rcu_dereference(fn->right) : 1421 rcu_dereference(fn->left); 1422 1423 if (next) { 1424 fn = next; 1425 continue; 1426 } 1427 break; 1428 } 1429 1430 while (fn) { 1431 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1432 1433 if (subtree || fn->fn_flags & RTN_RTINFO) { 1434 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1435 struct rt6key *key; 1436 1437 if (!leaf) 1438 goto backtrack; 1439 1440 key = (struct rt6key *) ((u8 *)leaf + args->offset); 1441 1442 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) { 1443 #ifdef CONFIG_IPV6_SUBTREES 1444 if (subtree) { 1445 struct fib6_node *sfn; 1446 sfn = fib6_node_lookup_1(subtree, 1447 args + 1); 1448 if (!sfn) 1449 goto backtrack; 1450 fn = sfn; 1451 } 1452 #endif 1453 if (fn->fn_flags & RTN_RTINFO) 1454 return fn; 1455 } 1456 } 1457 backtrack: 1458 if (fn->fn_flags & RTN_ROOT) 1459 break; 1460 1461 fn = rcu_dereference(fn->parent); 1462 } 1463 1464 return NULL; 1465 } 1466 1467 /* called with rcu_read_lock() held 1468 */ 1469 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 1470 const struct in6_addr *daddr, 1471 const struct in6_addr *saddr) 1472 { 1473 struct fib6_node *fn; 1474 struct lookup_args args[] = { 1475 { 1476 .offset = offsetof(struct fib6_info, fib6_dst), 1477 .addr = daddr, 1478 }, 1479 #ifdef CONFIG_IPV6_SUBTREES 1480 { 1481 .offset = offsetof(struct fib6_info, fib6_src), 1482 .addr = saddr, 1483 }, 1484 #endif 1485 { 1486 .offset = 0, /* sentinel */ 1487 } 1488 }; 1489 1490 fn = fib6_node_lookup_1(root, daddr ? args : args + 1); 1491 if (!fn || fn->fn_flags & RTN_TL_ROOT) 1492 fn = root; 1493 1494 return fn; 1495 } 1496 1497 /* 1498 * Get node with specified destination prefix (and source prefix, 1499 * if subtrees are used) 1500 * exact_match == true means we try to find fn with exact match of 1501 * the passed in prefix addr 1502 * exact_match == false means we try to find fn with longest prefix 1503 * match of the passed in prefix addr. This is useful for finding fn 1504 * for cached route as it will be stored in the exception table under 1505 * the node with longest prefix length. 1506 */ 1507 1508 1509 static struct fib6_node *fib6_locate_1(struct fib6_node *root, 1510 const struct in6_addr *addr, 1511 int plen, int offset, 1512 bool exact_match) 1513 { 1514 struct fib6_node *fn, *prev = NULL; 1515 1516 for (fn = root; fn ; ) { 1517 struct fib6_info *leaf = rcu_dereference(fn->leaf); 1518 struct rt6key *key; 1519 1520 /* This node is being deleted */ 1521 if (!leaf) { 1522 if (plen <= fn->fn_bit) 1523 goto out; 1524 else 1525 goto next; 1526 } 1527 1528 key = (struct rt6key *)((u8 *)leaf + offset); 1529 1530 /* 1531 * Prefix match 1532 */ 1533 if (plen < fn->fn_bit || 1534 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) 1535 goto out; 1536 1537 if (plen == fn->fn_bit) 1538 return fn; 1539 1540 prev = fn; 1541 1542 next: 1543 /* 1544 * We have more bits to go 1545 */ 1546 if (addr_bit_set(addr, fn->fn_bit)) 1547 fn = rcu_dereference(fn->right); 1548 else 1549 fn = rcu_dereference(fn->left); 1550 } 1551 out: 1552 if (exact_match) 1553 return NULL; 1554 else 1555 return prev; 1556 } 1557 1558 struct fib6_node *fib6_locate(struct fib6_node *root, 1559 const struct in6_addr *daddr, int dst_len, 1560 const struct in6_addr *saddr, int src_len, 1561 bool exact_match) 1562 { 1563 struct fib6_node *fn; 1564 1565 fn = fib6_locate_1(root, daddr, dst_len, 1566 offsetof(struct fib6_info, fib6_dst), 1567 exact_match); 1568 1569 #ifdef CONFIG_IPV6_SUBTREES 1570 if (src_len) { 1571 WARN_ON(saddr == NULL); 1572 if (fn) { 1573 struct fib6_node *subtree = FIB6_SUBTREE(fn); 1574 1575 if (subtree) { 1576 fn = fib6_locate_1(subtree, saddr, src_len, 1577 offsetof(struct fib6_info, fib6_src), 1578 exact_match); 1579 } 1580 } 1581 } 1582 #endif 1583 1584 if (fn && fn->fn_flags & RTN_RTINFO) 1585 return fn; 1586 1587 return NULL; 1588 } 1589 1590 1591 /* 1592 * Deletion 1593 * 1594 */ 1595 1596 static struct fib6_info *fib6_find_prefix(struct net *net, 1597 struct fib6_table *table, 1598 struct fib6_node *fn) 1599 { 1600 struct fib6_node *child_left, *child_right; 1601 1602 if (fn->fn_flags & RTN_ROOT) 1603 return net->ipv6.fib6_null_entry; 1604 1605 while (fn) { 1606 child_left = rcu_dereference_protected(fn->left, 1607 lockdep_is_held(&table->tb6_lock)); 1608 child_right = rcu_dereference_protected(fn->right, 1609 lockdep_is_held(&table->tb6_lock)); 1610 if (child_left) 1611 return rcu_dereference_protected(child_left->leaf, 1612 lockdep_is_held(&table->tb6_lock)); 1613 if (child_right) 1614 return rcu_dereference_protected(child_right->leaf, 1615 lockdep_is_held(&table->tb6_lock)); 1616 1617 fn = FIB6_SUBTREE(fn); 1618 } 1619 return NULL; 1620 } 1621 1622 /* 1623 * Called to trim the tree of intermediate nodes when possible. "fn" 1624 * is the node we want to try and remove. 1625 * Need to own table->tb6_lock 1626 */ 1627 1628 static struct fib6_node *fib6_repair_tree(struct net *net, 1629 struct fib6_table *table, 1630 struct fib6_node *fn) 1631 { 1632 int children; 1633 int nstate; 1634 struct fib6_node *child; 1635 struct fib6_walker *w; 1636 int iter = 0; 1637 1638 /* Set fn->leaf to null_entry for root node. */ 1639 if (fn->fn_flags & RTN_TL_ROOT) { 1640 rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry); 1641 return fn; 1642 } 1643 1644 for (;;) { 1645 struct fib6_node *fn_r = rcu_dereference_protected(fn->right, 1646 lockdep_is_held(&table->tb6_lock)); 1647 struct fib6_node *fn_l = rcu_dereference_protected(fn->left, 1648 lockdep_is_held(&table->tb6_lock)); 1649 struct fib6_node *pn = rcu_dereference_protected(fn->parent, 1650 lockdep_is_held(&table->tb6_lock)); 1651 struct fib6_node *pn_r = rcu_dereference_protected(pn->right, 1652 lockdep_is_held(&table->tb6_lock)); 1653 struct fib6_node *pn_l = rcu_dereference_protected(pn->left, 1654 lockdep_is_held(&table->tb6_lock)); 1655 struct fib6_info *fn_leaf = rcu_dereference_protected(fn->leaf, 1656 lockdep_is_held(&table->tb6_lock)); 1657 struct fib6_info *pn_leaf = rcu_dereference_protected(pn->leaf, 1658 lockdep_is_held(&table->tb6_lock)); 1659 struct fib6_info *new_fn_leaf; 1660 1661 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter); 1662 iter++; 1663 1664 WARN_ON(fn->fn_flags & RTN_RTINFO); 1665 WARN_ON(fn->fn_flags & RTN_TL_ROOT); 1666 WARN_ON(fn_leaf); 1667 1668 children = 0; 1669 child = NULL; 1670 if (fn_r) 1671 child = fn_r, children |= 1; 1672 if (fn_l) 1673 child = fn_l, children |= 2; 1674 1675 if (children == 3 || FIB6_SUBTREE(fn) 1676 #ifdef CONFIG_IPV6_SUBTREES 1677 /* Subtree root (i.e. fn) may have one child */ 1678 || (children && fn->fn_flags & RTN_ROOT) 1679 #endif 1680 ) { 1681 new_fn_leaf = fib6_find_prefix(net, table, fn); 1682 #if RT6_DEBUG >= 2 1683 if (!new_fn_leaf) { 1684 WARN_ON(!new_fn_leaf); 1685 new_fn_leaf = net->ipv6.fib6_null_entry; 1686 } 1687 #endif 1688 fib6_info_hold(new_fn_leaf); 1689 rcu_assign_pointer(fn->leaf, new_fn_leaf); 1690 return pn; 1691 } 1692 1693 #ifdef CONFIG_IPV6_SUBTREES 1694 if (FIB6_SUBTREE(pn) == fn) { 1695 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1696 RCU_INIT_POINTER(pn->subtree, NULL); 1697 nstate = FWS_L; 1698 } else { 1699 WARN_ON(fn->fn_flags & RTN_ROOT); 1700 #endif 1701 if (pn_r == fn) 1702 rcu_assign_pointer(pn->right, child); 1703 else if (pn_l == fn) 1704 rcu_assign_pointer(pn->left, child); 1705 #if RT6_DEBUG >= 2 1706 else 1707 WARN_ON(1); 1708 #endif 1709 if (child) 1710 rcu_assign_pointer(child->parent, pn); 1711 nstate = FWS_R; 1712 #ifdef CONFIG_IPV6_SUBTREES 1713 } 1714 #endif 1715 1716 read_lock(&net->ipv6.fib6_walker_lock); 1717 FOR_WALKERS(net, w) { 1718 if (!child) { 1719 if (w->node == fn) { 1720 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate); 1721 w->node = pn; 1722 w->state = nstate; 1723 } 1724 } else { 1725 if (w->node == fn) { 1726 w->node = child; 1727 if (children&2) { 1728 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1729 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT; 1730 } else { 1731 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state); 1732 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT; 1733 } 1734 } 1735 } 1736 } 1737 read_unlock(&net->ipv6.fib6_walker_lock); 1738 1739 node_free(net, fn); 1740 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn)) 1741 return pn; 1742 1743 RCU_INIT_POINTER(pn->leaf, NULL); 1744 fib6_info_release(pn_leaf); 1745 fn = pn; 1746 } 1747 } 1748 1749 static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn, 1750 struct fib6_info __rcu **rtp, struct nl_info *info) 1751 { 1752 struct fib6_walker *w; 1753 struct fib6_info *rt = rcu_dereference_protected(*rtp, 1754 lockdep_is_held(&table->tb6_lock)); 1755 struct net *net = info->nl_net; 1756 1757 RT6_TRACE("fib6_del_route\n"); 1758 1759 /* Unlink it */ 1760 *rtp = rt->fib6_next; 1761 rt->fib6_node = NULL; 1762 net->ipv6.rt6_stats->fib_rt_entries--; 1763 net->ipv6.rt6_stats->fib_discarded_routes++; 1764 1765 /* Flush all cached dst in exception table */ 1766 rt6_flush_exceptions(rt); 1767 1768 /* Reset round-robin state, if necessary */ 1769 if (rcu_access_pointer(fn->rr_ptr) == rt) 1770 fn->rr_ptr = NULL; 1771 1772 /* Remove this entry from other siblings */ 1773 if (rt->fib6_nsiblings) { 1774 struct fib6_info *sibling, *next_sibling; 1775 1776 list_for_each_entry_safe(sibling, next_sibling, 1777 &rt->fib6_siblings, fib6_siblings) 1778 sibling->fib6_nsiblings--; 1779 rt->fib6_nsiblings = 0; 1780 list_del_init(&rt->fib6_siblings); 1781 rt6_multipath_rebalance(next_sibling); 1782 } 1783 1784 /* Adjust walkers */ 1785 read_lock(&net->ipv6.fib6_walker_lock); 1786 FOR_WALKERS(net, w) { 1787 if (w->state == FWS_C && w->leaf == rt) { 1788 RT6_TRACE("walker %p adjusted by delroute\n", w); 1789 w->leaf = rcu_dereference_protected(rt->fib6_next, 1790 lockdep_is_held(&table->tb6_lock)); 1791 if (!w->leaf) 1792 w->state = FWS_U; 1793 } 1794 } 1795 read_unlock(&net->ipv6.fib6_walker_lock); 1796 1797 /* If it was last route, call fib6_repair_tree() to: 1798 * 1. For root node, put back null_entry as how the table was created. 1799 * 2. For other nodes, expunge its radix tree node. 1800 */ 1801 if (!rcu_access_pointer(fn->leaf)) { 1802 if (!(fn->fn_flags & RTN_TL_ROOT)) { 1803 fn->fn_flags &= ~RTN_RTINFO; 1804 net->ipv6.rt6_stats->fib_route_nodes--; 1805 } 1806 fn = fib6_repair_tree(net, table, fn); 1807 } 1808 1809 fib6_purge_rt(rt, fn, net); 1810 1811 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL); 1812 if (!info->skip_notify) 1813 inet6_rt_notify(RTM_DELROUTE, rt, info, 0); 1814 fib6_info_release(rt); 1815 } 1816 1817 /* Need to own table->tb6_lock */ 1818 int fib6_del(struct fib6_info *rt, struct nl_info *info) 1819 { 1820 struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node, 1821 lockdep_is_held(&rt->fib6_table->tb6_lock)); 1822 struct fib6_table *table = rt->fib6_table; 1823 struct net *net = info->nl_net; 1824 struct fib6_info __rcu **rtp; 1825 struct fib6_info __rcu **rtp_next; 1826 1827 if (!fn || rt == net->ipv6.fib6_null_entry) 1828 return -ENOENT; 1829 1830 WARN_ON(!(fn->fn_flags & RTN_RTINFO)); 1831 1832 /* 1833 * Walk the leaf entries looking for ourself 1834 */ 1835 1836 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) { 1837 struct fib6_info *cur = rcu_dereference_protected(*rtp, 1838 lockdep_is_held(&table->tb6_lock)); 1839 if (rt == cur) { 1840 fib6_del_route(table, fn, rtp, info); 1841 return 0; 1842 } 1843 rtp_next = &cur->fib6_next; 1844 } 1845 return -ENOENT; 1846 } 1847 1848 /* 1849 * Tree traversal function. 1850 * 1851 * Certainly, it is not interrupt safe. 1852 * However, it is internally reenterable wrt itself and fib6_add/fib6_del. 1853 * It means, that we can modify tree during walking 1854 * and use this function for garbage collection, clone pruning, 1855 * cleaning tree when a device goes down etc. etc. 1856 * 1857 * It guarantees that every node will be traversed, 1858 * and that it will be traversed only once. 1859 * 1860 * Callback function w->func may return: 1861 * 0 -> continue walking. 1862 * positive value -> walking is suspended (used by tree dumps, 1863 * and probably by gc, if it will be split to several slices) 1864 * negative value -> terminate walking. 1865 * 1866 * The function itself returns: 1867 * 0 -> walk is complete. 1868 * >0 -> walk is incomplete (i.e. suspended) 1869 * <0 -> walk is terminated by an error. 1870 * 1871 * This function is called with tb6_lock held. 1872 */ 1873 1874 static int fib6_walk_continue(struct fib6_walker *w) 1875 { 1876 struct fib6_node *fn, *pn, *left, *right; 1877 1878 /* w->root should always be table->tb6_root */ 1879 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT)); 1880 1881 for (;;) { 1882 fn = w->node; 1883 if (!fn) 1884 return 0; 1885 1886 switch (w->state) { 1887 #ifdef CONFIG_IPV6_SUBTREES 1888 case FWS_S: 1889 if (FIB6_SUBTREE(fn)) { 1890 w->node = FIB6_SUBTREE(fn); 1891 continue; 1892 } 1893 w->state = FWS_L; 1894 #endif 1895 /* fall through */ 1896 case FWS_L: 1897 left = rcu_dereference_protected(fn->left, 1); 1898 if (left) { 1899 w->node = left; 1900 w->state = FWS_INIT; 1901 continue; 1902 } 1903 w->state = FWS_R; 1904 /* fall through */ 1905 case FWS_R: 1906 right = rcu_dereference_protected(fn->right, 1); 1907 if (right) { 1908 w->node = right; 1909 w->state = FWS_INIT; 1910 continue; 1911 } 1912 w->state = FWS_C; 1913 w->leaf = rcu_dereference_protected(fn->leaf, 1); 1914 /* fall through */ 1915 case FWS_C: 1916 if (w->leaf && fn->fn_flags & RTN_RTINFO) { 1917 int err; 1918 1919 if (w->skip) { 1920 w->skip--; 1921 goto skip; 1922 } 1923 1924 err = w->func(w); 1925 if (err) 1926 return err; 1927 1928 w->count++; 1929 continue; 1930 } 1931 skip: 1932 w->state = FWS_U; 1933 /* fall through */ 1934 case FWS_U: 1935 if (fn == w->root) 1936 return 0; 1937 pn = rcu_dereference_protected(fn->parent, 1); 1938 left = rcu_dereference_protected(pn->left, 1); 1939 right = rcu_dereference_protected(pn->right, 1); 1940 w->node = pn; 1941 #ifdef CONFIG_IPV6_SUBTREES 1942 if (FIB6_SUBTREE(pn) == fn) { 1943 WARN_ON(!(fn->fn_flags & RTN_ROOT)); 1944 w->state = FWS_L; 1945 continue; 1946 } 1947 #endif 1948 if (left == fn) { 1949 w->state = FWS_R; 1950 continue; 1951 } 1952 if (right == fn) { 1953 w->state = FWS_C; 1954 w->leaf = rcu_dereference_protected(w->node->leaf, 1); 1955 continue; 1956 } 1957 #if RT6_DEBUG >= 2 1958 WARN_ON(1); 1959 #endif 1960 } 1961 } 1962 } 1963 1964 static int fib6_walk(struct net *net, struct fib6_walker *w) 1965 { 1966 int res; 1967 1968 w->state = FWS_INIT; 1969 w->node = w->root; 1970 1971 fib6_walker_link(net, w); 1972 res = fib6_walk_continue(w); 1973 if (res <= 0) 1974 fib6_walker_unlink(net, w); 1975 return res; 1976 } 1977 1978 static int fib6_clean_node(struct fib6_walker *w) 1979 { 1980 int res; 1981 struct fib6_info *rt; 1982 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w); 1983 struct nl_info info = { 1984 .nl_net = c->net, 1985 .skip_notify = c->skip_notify, 1986 }; 1987 1988 if (c->sernum != FIB6_NO_SERNUM_CHANGE && 1989 w->node->fn_sernum != c->sernum) 1990 w->node->fn_sernum = c->sernum; 1991 1992 if (!c->func) { 1993 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE); 1994 w->leaf = NULL; 1995 return 0; 1996 } 1997 1998 for_each_fib6_walker_rt(w) { 1999 res = c->func(rt, c->arg); 2000 if (res == -1) { 2001 w->leaf = rt; 2002 res = fib6_del(rt, &info); 2003 if (res) { 2004 #if RT6_DEBUG >= 2 2005 pr_debug("%s: del failed: rt=%p@%p err=%d\n", 2006 __func__, rt, 2007 rcu_access_pointer(rt->fib6_node), 2008 res); 2009 #endif 2010 continue; 2011 } 2012 return 0; 2013 } else if (res == -2) { 2014 if (WARN_ON(!rt->fib6_nsiblings)) 2015 continue; 2016 rt = list_last_entry(&rt->fib6_siblings, 2017 struct fib6_info, fib6_siblings); 2018 continue; 2019 } 2020 WARN_ON(res != 0); 2021 } 2022 w->leaf = rt; 2023 return 0; 2024 } 2025 2026 /* 2027 * Convenient frontend to tree walker. 2028 * 2029 * func is called on each route. 2030 * It may return -2 -> skip multipath route. 2031 * -1 -> delete this route. 2032 * 0 -> continue walking 2033 */ 2034 2035 static void fib6_clean_tree(struct net *net, struct fib6_node *root, 2036 int (*func)(struct fib6_info *, void *arg), 2037 int sernum, void *arg, bool skip_notify) 2038 { 2039 struct fib6_cleaner c; 2040 2041 c.w.root = root; 2042 c.w.func = fib6_clean_node; 2043 c.w.count = 0; 2044 c.w.skip = 0; 2045 c.func = func; 2046 c.sernum = sernum; 2047 c.arg = arg; 2048 c.net = net; 2049 c.skip_notify = skip_notify; 2050 2051 fib6_walk(net, &c.w); 2052 } 2053 2054 static void __fib6_clean_all(struct net *net, 2055 int (*func)(struct fib6_info *, void *), 2056 int sernum, void *arg, bool skip_notify) 2057 { 2058 struct fib6_table *table; 2059 struct hlist_head *head; 2060 unsigned int h; 2061 2062 rcu_read_lock(); 2063 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 2064 head = &net->ipv6.fib_table_hash[h]; 2065 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 2066 spin_lock_bh(&table->tb6_lock); 2067 fib6_clean_tree(net, &table->tb6_root, 2068 func, sernum, arg, skip_notify); 2069 spin_unlock_bh(&table->tb6_lock); 2070 } 2071 } 2072 rcu_read_unlock(); 2073 } 2074 2075 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *), 2076 void *arg) 2077 { 2078 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, false); 2079 } 2080 2081 void fib6_clean_all_skip_notify(struct net *net, 2082 int (*func)(struct fib6_info *, void *), 2083 void *arg) 2084 { 2085 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, true); 2086 } 2087 2088 static void fib6_flush_trees(struct net *net) 2089 { 2090 int new_sernum = fib6_new_sernum(net); 2091 2092 __fib6_clean_all(net, NULL, new_sernum, NULL, false); 2093 } 2094 2095 /* 2096 * Garbage collection 2097 */ 2098 2099 static int fib6_age(struct fib6_info *rt, void *arg) 2100 { 2101 struct fib6_gc_args *gc_args = arg; 2102 unsigned long now = jiffies; 2103 2104 /* 2105 * check addrconf expiration here. 2106 * Routes are expired even if they are in use. 2107 */ 2108 2109 if (rt->fib6_flags & RTF_EXPIRES && rt->expires) { 2110 if (time_after(now, rt->expires)) { 2111 RT6_TRACE("expiring %p\n", rt); 2112 return -1; 2113 } 2114 gc_args->more++; 2115 } 2116 2117 /* Also age clones in the exception table. 2118 * Note, that clones are aged out 2119 * only if they are not in use now. 2120 */ 2121 rt6_age_exceptions(rt, gc_args, now); 2122 2123 return 0; 2124 } 2125 2126 void fib6_run_gc(unsigned long expires, struct net *net, bool force) 2127 { 2128 struct fib6_gc_args gc_args; 2129 unsigned long now; 2130 2131 if (force) { 2132 spin_lock_bh(&net->ipv6.fib6_gc_lock); 2133 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) { 2134 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ); 2135 return; 2136 } 2137 gc_args.timeout = expires ? (int)expires : 2138 net->ipv6.sysctl.ip6_rt_gc_interval; 2139 gc_args.more = 0; 2140 2141 fib6_clean_all(net, fib6_age, &gc_args); 2142 now = jiffies; 2143 net->ipv6.ip6_rt_last_gc = now; 2144 2145 if (gc_args.more) 2146 mod_timer(&net->ipv6.ip6_fib_timer, 2147 round_jiffies(now 2148 + net->ipv6.sysctl.ip6_rt_gc_interval)); 2149 else 2150 del_timer(&net->ipv6.ip6_fib_timer); 2151 spin_unlock_bh(&net->ipv6.fib6_gc_lock); 2152 } 2153 2154 static void fib6_gc_timer_cb(struct timer_list *t) 2155 { 2156 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer); 2157 2158 fib6_run_gc(0, arg, true); 2159 } 2160 2161 static int __net_init fib6_net_init(struct net *net) 2162 { 2163 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ; 2164 int err; 2165 2166 err = fib6_notifier_init(net); 2167 if (err) 2168 return err; 2169 2170 spin_lock_init(&net->ipv6.fib6_gc_lock); 2171 rwlock_init(&net->ipv6.fib6_walker_lock); 2172 INIT_LIST_HEAD(&net->ipv6.fib6_walkers); 2173 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0); 2174 2175 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL); 2176 if (!net->ipv6.rt6_stats) 2177 goto out_timer; 2178 2179 /* Avoid false sharing : Use at least a full cache line */ 2180 size = max_t(size_t, size, L1_CACHE_BYTES); 2181 2182 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL); 2183 if (!net->ipv6.fib_table_hash) 2184 goto out_rt6_stats; 2185 2186 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), 2187 GFP_KERNEL); 2188 if (!net->ipv6.fib6_main_tbl) 2189 goto out_fib_table_hash; 2190 2191 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN; 2192 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf, 2193 net->ipv6.fib6_null_entry); 2194 net->ipv6.fib6_main_tbl->tb6_root.fn_flags = 2195 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2196 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers); 2197 2198 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2199 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl), 2200 GFP_KERNEL); 2201 if (!net->ipv6.fib6_local_tbl) 2202 goto out_fib6_main_tbl; 2203 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL; 2204 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf, 2205 net->ipv6.fib6_null_entry); 2206 net->ipv6.fib6_local_tbl->tb6_root.fn_flags = 2207 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO; 2208 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers); 2209 #endif 2210 fib6_tables_init(net); 2211 2212 return 0; 2213 2214 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2215 out_fib6_main_tbl: 2216 kfree(net->ipv6.fib6_main_tbl); 2217 #endif 2218 out_fib_table_hash: 2219 kfree(net->ipv6.fib_table_hash); 2220 out_rt6_stats: 2221 kfree(net->ipv6.rt6_stats); 2222 out_timer: 2223 fib6_notifier_exit(net); 2224 return -ENOMEM; 2225 } 2226 2227 static void fib6_net_exit(struct net *net) 2228 { 2229 unsigned int i; 2230 2231 del_timer_sync(&net->ipv6.ip6_fib_timer); 2232 2233 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) { 2234 struct hlist_head *head = &net->ipv6.fib_table_hash[i]; 2235 struct hlist_node *tmp; 2236 struct fib6_table *tb; 2237 2238 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) { 2239 hlist_del(&tb->tb6_hlist); 2240 fib6_free_table(tb); 2241 } 2242 } 2243 2244 kfree(net->ipv6.fib_table_hash); 2245 kfree(net->ipv6.rt6_stats); 2246 fib6_notifier_exit(net); 2247 } 2248 2249 static struct pernet_operations fib6_net_ops = { 2250 .init = fib6_net_init, 2251 .exit = fib6_net_exit, 2252 }; 2253 2254 int __init fib6_init(void) 2255 { 2256 int ret = -ENOMEM; 2257 2258 fib6_node_kmem = kmem_cache_create("fib6_nodes", 2259 sizeof(struct fib6_node), 2260 0, SLAB_HWCACHE_ALIGN, 2261 NULL); 2262 if (!fib6_node_kmem) 2263 goto out; 2264 2265 ret = register_pernet_subsys(&fib6_net_ops); 2266 if (ret) 2267 goto out_kmem_cache_create; 2268 2269 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL, 2270 inet6_dump_fib, 0); 2271 if (ret) 2272 goto out_unregister_subsys; 2273 2274 __fib6_flush_trees = fib6_flush_trees; 2275 out: 2276 return ret; 2277 2278 out_unregister_subsys: 2279 unregister_pernet_subsys(&fib6_net_ops); 2280 out_kmem_cache_create: 2281 kmem_cache_destroy(fib6_node_kmem); 2282 goto out; 2283 } 2284 2285 void fib6_gc_cleanup(void) 2286 { 2287 unregister_pernet_subsys(&fib6_net_ops); 2288 kmem_cache_destroy(fib6_node_kmem); 2289 } 2290 2291 #ifdef CONFIG_PROC_FS 2292 static int ipv6_route_seq_show(struct seq_file *seq, void *v) 2293 { 2294 struct fib6_info *rt = v; 2295 struct ipv6_route_iter *iter = seq->private; 2296 const struct net_device *dev; 2297 2298 seq_printf(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen); 2299 2300 #ifdef CONFIG_IPV6_SUBTREES 2301 seq_printf(seq, "%pi6 %02x ", &rt->fib6_src.addr, rt->fib6_src.plen); 2302 #else 2303 seq_puts(seq, "00000000000000000000000000000000 00 "); 2304 #endif 2305 if (rt->fib6_flags & RTF_GATEWAY) 2306 seq_printf(seq, "%pi6", &rt->fib6_nh.nh_gw); 2307 else 2308 seq_puts(seq, "00000000000000000000000000000000"); 2309 2310 dev = rt->fib6_nh.nh_dev; 2311 seq_printf(seq, " %08x %08x %08x %08x %8s\n", 2312 rt->fib6_metric, atomic_read(&rt->fib6_ref), 0, 2313 rt->fib6_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