1 /* 2 * This program is free software; you can redistribute it and/or 3 * modify it under the terms of the GNU General Public License 4 * as published by the Free Software Foundation; either version 5 * 2 of the License, or (at your option) any later version. 6 * 7 * Robert Olsson <robert.olsson@its.uu.se> Uppsala Universitet 8 * & Swedish University of Agricultural Sciences. 9 * 10 * Jens Laas <jens.laas@data.slu.se> Swedish University of 11 * Agricultural Sciences. 12 * 13 * Hans Liss <hans.liss@its.uu.se> Uppsala Universitet 14 * 15 * This work is based on the LPC-trie which is originally described in: 16 * 17 * An experimental study of compression methods for dynamic tries 18 * Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002. 19 * http://www.csc.kth.se/~snilsson/software/dyntrie2/ 20 * 21 * 22 * IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson 23 * IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999 24 * 25 * 26 * Code from fib_hash has been reused which includes the following header: 27 * 28 * 29 * INET An implementation of the TCP/IP protocol suite for the LINUX 30 * operating system. INET is implemented using the BSD Socket 31 * interface as the means of communication with the user level. 32 * 33 * IPv4 FIB: lookup engine and maintenance routines. 34 * 35 * 36 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 37 * 38 * This program is free software; you can redistribute it and/or 39 * modify it under the terms of the GNU General Public License 40 * as published by the Free Software Foundation; either version 41 * 2 of the License, or (at your option) any later version. 42 * 43 * Substantial contributions to this work comes from: 44 * 45 * David S. Miller, <davem@davemloft.net> 46 * Stephen Hemminger <shemminger@osdl.org> 47 * Paul E. McKenney <paulmck@us.ibm.com> 48 * Patrick McHardy <kaber@trash.net> 49 */ 50 51 #define VERSION "0.409" 52 53 #include <asm/uaccess.h> 54 #include <linux/bitops.h> 55 #include <linux/types.h> 56 #include <linux/kernel.h> 57 #include <linux/mm.h> 58 #include <linux/string.h> 59 #include <linux/socket.h> 60 #include <linux/sockios.h> 61 #include <linux/errno.h> 62 #include <linux/in.h> 63 #include <linux/inet.h> 64 #include <linux/inetdevice.h> 65 #include <linux/netdevice.h> 66 #include <linux/if_arp.h> 67 #include <linux/proc_fs.h> 68 #include <linux/rcupdate.h> 69 #include <linux/skbuff.h> 70 #include <linux/netlink.h> 71 #include <linux/init.h> 72 #include <linux/list.h> 73 #include <linux/slab.h> 74 #include <linux/export.h> 75 #include <linux/vmalloc.h> 76 #include <linux/notifier.h> 77 #include <net/net_namespace.h> 78 #include <net/ip.h> 79 #include <net/protocol.h> 80 #include <net/route.h> 81 #include <net/tcp.h> 82 #include <net/sock.h> 83 #include <net/ip_fib.h> 84 #include <trace/events/fib.h> 85 #include "fib_lookup.h" 86 87 static BLOCKING_NOTIFIER_HEAD(fib_chain); 88 89 int register_fib_notifier(struct notifier_block *nb) 90 { 91 return blocking_notifier_chain_register(&fib_chain, nb); 92 } 93 EXPORT_SYMBOL(register_fib_notifier); 94 95 int unregister_fib_notifier(struct notifier_block *nb) 96 { 97 return blocking_notifier_chain_unregister(&fib_chain, nb); 98 } 99 EXPORT_SYMBOL(unregister_fib_notifier); 100 101 int call_fib_notifiers(struct net *net, enum fib_event_type event_type, 102 struct fib_notifier_info *info) 103 { 104 info->net = net; 105 return blocking_notifier_call_chain(&fib_chain, event_type, info); 106 } 107 108 static int call_fib_entry_notifiers(struct net *net, 109 enum fib_event_type event_type, u32 dst, 110 int dst_len, struct fib_info *fi, 111 u8 tos, u8 type, u32 tb_id, u32 nlflags) 112 { 113 struct fib_entry_notifier_info info = { 114 .dst = dst, 115 .dst_len = dst_len, 116 .fi = fi, 117 .tos = tos, 118 .type = type, 119 .tb_id = tb_id, 120 .nlflags = nlflags, 121 }; 122 return call_fib_notifiers(net, event_type, &info.info); 123 } 124 125 #define MAX_STAT_DEPTH 32 126 127 #define KEYLENGTH (8*sizeof(t_key)) 128 #define KEY_MAX ((t_key)~0) 129 130 typedef unsigned int t_key; 131 132 #define IS_TRIE(n) ((n)->pos >= KEYLENGTH) 133 #define IS_TNODE(n) ((n)->bits) 134 #define IS_LEAF(n) (!(n)->bits) 135 136 struct key_vector { 137 t_key key; 138 unsigned char pos; /* 2log(KEYLENGTH) bits needed */ 139 unsigned char bits; /* 2log(KEYLENGTH) bits needed */ 140 unsigned char slen; 141 union { 142 /* This list pointer if valid if (pos | bits) == 0 (LEAF) */ 143 struct hlist_head leaf; 144 /* This array is valid if (pos | bits) > 0 (TNODE) */ 145 struct key_vector __rcu *tnode[0]; 146 }; 147 }; 148 149 struct tnode { 150 struct rcu_head rcu; 151 t_key empty_children; /* KEYLENGTH bits needed */ 152 t_key full_children; /* KEYLENGTH bits needed */ 153 struct key_vector __rcu *parent; 154 struct key_vector kv[1]; 155 #define tn_bits kv[0].bits 156 }; 157 158 #define TNODE_SIZE(n) offsetof(struct tnode, kv[0].tnode[n]) 159 #define LEAF_SIZE TNODE_SIZE(1) 160 161 #ifdef CONFIG_IP_FIB_TRIE_STATS 162 struct trie_use_stats { 163 unsigned int gets; 164 unsigned int backtrack; 165 unsigned int semantic_match_passed; 166 unsigned int semantic_match_miss; 167 unsigned int null_node_hit; 168 unsigned int resize_node_skipped; 169 }; 170 #endif 171 172 struct trie_stat { 173 unsigned int totdepth; 174 unsigned int maxdepth; 175 unsigned int tnodes; 176 unsigned int leaves; 177 unsigned int nullpointers; 178 unsigned int prefixes; 179 unsigned int nodesizes[MAX_STAT_DEPTH]; 180 }; 181 182 struct trie { 183 struct key_vector kv[1]; 184 #ifdef CONFIG_IP_FIB_TRIE_STATS 185 struct trie_use_stats __percpu *stats; 186 #endif 187 }; 188 189 static struct key_vector *resize(struct trie *t, struct key_vector *tn); 190 static size_t tnode_free_size; 191 192 /* 193 * synchronize_rcu after call_rcu for that many pages; it should be especially 194 * useful before resizing the root node with PREEMPT_NONE configs; the value was 195 * obtained experimentally, aiming to avoid visible slowdown. 196 */ 197 static const int sync_pages = 128; 198 199 static struct kmem_cache *fn_alias_kmem __read_mostly; 200 static struct kmem_cache *trie_leaf_kmem __read_mostly; 201 202 static inline struct tnode *tn_info(struct key_vector *kv) 203 { 204 return container_of(kv, struct tnode, kv[0]); 205 } 206 207 /* caller must hold RTNL */ 208 #define node_parent(tn) rtnl_dereference(tn_info(tn)->parent) 209 #define get_child(tn, i) rtnl_dereference((tn)->tnode[i]) 210 211 /* caller must hold RCU read lock or RTNL */ 212 #define node_parent_rcu(tn) rcu_dereference_rtnl(tn_info(tn)->parent) 213 #define get_child_rcu(tn, i) rcu_dereference_rtnl((tn)->tnode[i]) 214 215 /* wrapper for rcu_assign_pointer */ 216 static inline void node_set_parent(struct key_vector *n, struct key_vector *tp) 217 { 218 if (n) 219 rcu_assign_pointer(tn_info(n)->parent, tp); 220 } 221 222 #define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER(tn_info(n)->parent, p) 223 224 /* This provides us with the number of children in this node, in the case of a 225 * leaf this will return 0 meaning none of the children are accessible. 226 */ 227 static inline unsigned long child_length(const struct key_vector *tn) 228 { 229 return (1ul << tn->bits) & ~(1ul); 230 } 231 232 #define get_cindex(key, kv) (((key) ^ (kv)->key) >> (kv)->pos) 233 234 static inline unsigned long get_index(t_key key, struct key_vector *kv) 235 { 236 unsigned long index = key ^ kv->key; 237 238 if ((BITS_PER_LONG <= KEYLENGTH) && (KEYLENGTH == kv->pos)) 239 return 0; 240 241 return index >> kv->pos; 242 } 243 244 /* To understand this stuff, an understanding of keys and all their bits is 245 * necessary. Every node in the trie has a key associated with it, but not 246 * all of the bits in that key are significant. 247 * 248 * Consider a node 'n' and its parent 'tp'. 249 * 250 * If n is a leaf, every bit in its key is significant. Its presence is 251 * necessitated by path compression, since during a tree traversal (when 252 * searching for a leaf - unless we are doing an insertion) we will completely 253 * ignore all skipped bits we encounter. Thus we need to verify, at the end of 254 * a potentially successful search, that we have indeed been walking the 255 * correct key path. 256 * 257 * Note that we can never "miss" the correct key in the tree if present by 258 * following the wrong path. Path compression ensures that segments of the key 259 * that are the same for all keys with a given prefix are skipped, but the 260 * skipped part *is* identical for each node in the subtrie below the skipped 261 * bit! trie_insert() in this implementation takes care of that. 262 * 263 * if n is an internal node - a 'tnode' here, the various parts of its key 264 * have many different meanings. 265 * 266 * Example: 267 * _________________________________________________________________ 268 * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C | 269 * ----------------------------------------------------------------- 270 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 271 * 272 * _________________________________________________________________ 273 * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u | 274 * ----------------------------------------------------------------- 275 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 276 * 277 * tp->pos = 22 278 * tp->bits = 3 279 * n->pos = 13 280 * n->bits = 4 281 * 282 * First, let's just ignore the bits that come before the parent tp, that is 283 * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this 284 * point we do not use them for anything. 285 * 286 * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the 287 * index into the parent's child array. That is, they will be used to find 288 * 'n' among tp's children. 289 * 290 * The bits from (n->pos + n->bits) to (tp->pos - 1) - "S" - are skipped bits 291 * for the node n. 292 * 293 * All the bits we have seen so far are significant to the node n. The rest 294 * of the bits are really not needed or indeed known in n->key. 295 * 296 * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into 297 * n's child array, and will of course be different for each child. 298 * 299 * The rest of the bits, from 0 to (n->pos -1) - "u" - are completely unknown 300 * at this point. 301 */ 302 303 static const int halve_threshold = 25; 304 static const int inflate_threshold = 50; 305 static const int halve_threshold_root = 15; 306 static const int inflate_threshold_root = 30; 307 308 static void __alias_free_mem(struct rcu_head *head) 309 { 310 struct fib_alias *fa = container_of(head, struct fib_alias, rcu); 311 kmem_cache_free(fn_alias_kmem, fa); 312 } 313 314 static inline void alias_free_mem_rcu(struct fib_alias *fa) 315 { 316 call_rcu(&fa->rcu, __alias_free_mem); 317 } 318 319 #define TNODE_KMALLOC_MAX \ 320 ilog2((PAGE_SIZE - TNODE_SIZE(0)) / sizeof(struct key_vector *)) 321 #define TNODE_VMALLOC_MAX \ 322 ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *)) 323 324 static void __node_free_rcu(struct rcu_head *head) 325 { 326 struct tnode *n = container_of(head, struct tnode, rcu); 327 328 if (!n->tn_bits) 329 kmem_cache_free(trie_leaf_kmem, n); 330 else 331 kvfree(n); 332 } 333 334 #define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu) 335 336 static struct tnode *tnode_alloc(int bits) 337 { 338 size_t size; 339 340 /* verify bits is within bounds */ 341 if (bits > TNODE_VMALLOC_MAX) 342 return NULL; 343 344 /* determine size and verify it is non-zero and didn't overflow */ 345 size = TNODE_SIZE(1ul << bits); 346 347 if (size <= PAGE_SIZE) 348 return kzalloc(size, GFP_KERNEL); 349 else 350 return vzalloc(size); 351 } 352 353 static inline void empty_child_inc(struct key_vector *n) 354 { 355 ++tn_info(n)->empty_children ? : ++tn_info(n)->full_children; 356 } 357 358 static inline void empty_child_dec(struct key_vector *n) 359 { 360 tn_info(n)->empty_children-- ? : tn_info(n)->full_children--; 361 } 362 363 static struct key_vector *leaf_new(t_key key, struct fib_alias *fa) 364 { 365 struct key_vector *l; 366 struct tnode *kv; 367 368 kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL); 369 if (!kv) 370 return NULL; 371 372 /* initialize key vector */ 373 l = kv->kv; 374 l->key = key; 375 l->pos = 0; 376 l->bits = 0; 377 l->slen = fa->fa_slen; 378 379 /* link leaf to fib alias */ 380 INIT_HLIST_HEAD(&l->leaf); 381 hlist_add_head(&fa->fa_list, &l->leaf); 382 383 return l; 384 } 385 386 static struct key_vector *tnode_new(t_key key, int pos, int bits) 387 { 388 unsigned int shift = pos + bits; 389 struct key_vector *tn; 390 struct tnode *tnode; 391 392 /* verify bits and pos their msb bits clear and values are valid */ 393 BUG_ON(!bits || (shift > KEYLENGTH)); 394 395 tnode = tnode_alloc(bits); 396 if (!tnode) 397 return NULL; 398 399 pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0), 400 sizeof(struct key_vector *) << bits); 401 402 if (bits == KEYLENGTH) 403 tnode->full_children = 1; 404 else 405 tnode->empty_children = 1ul << bits; 406 407 tn = tnode->kv; 408 tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0; 409 tn->pos = pos; 410 tn->bits = bits; 411 tn->slen = pos; 412 413 return tn; 414 } 415 416 /* Check whether a tnode 'n' is "full", i.e. it is an internal node 417 * and no bits are skipped. See discussion in dyntree paper p. 6 418 */ 419 static inline int tnode_full(struct key_vector *tn, struct key_vector *n) 420 { 421 return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n); 422 } 423 424 /* Add a child at position i overwriting the old value. 425 * Update the value of full_children and empty_children. 426 */ 427 static void put_child(struct key_vector *tn, unsigned long i, 428 struct key_vector *n) 429 { 430 struct key_vector *chi = get_child(tn, i); 431 int isfull, wasfull; 432 433 BUG_ON(i >= child_length(tn)); 434 435 /* update emptyChildren, overflow into fullChildren */ 436 if (!n && chi) 437 empty_child_inc(tn); 438 if (n && !chi) 439 empty_child_dec(tn); 440 441 /* update fullChildren */ 442 wasfull = tnode_full(tn, chi); 443 isfull = tnode_full(tn, n); 444 445 if (wasfull && !isfull) 446 tn_info(tn)->full_children--; 447 else if (!wasfull && isfull) 448 tn_info(tn)->full_children++; 449 450 if (n && (tn->slen < n->slen)) 451 tn->slen = n->slen; 452 453 rcu_assign_pointer(tn->tnode[i], n); 454 } 455 456 static void update_children(struct key_vector *tn) 457 { 458 unsigned long i; 459 460 /* update all of the child parent pointers */ 461 for (i = child_length(tn); i;) { 462 struct key_vector *inode = get_child(tn, --i); 463 464 if (!inode) 465 continue; 466 467 /* Either update the children of a tnode that 468 * already belongs to us or update the child 469 * to point to ourselves. 470 */ 471 if (node_parent(inode) == tn) 472 update_children(inode); 473 else 474 node_set_parent(inode, tn); 475 } 476 } 477 478 static inline void put_child_root(struct key_vector *tp, t_key key, 479 struct key_vector *n) 480 { 481 if (IS_TRIE(tp)) 482 rcu_assign_pointer(tp->tnode[0], n); 483 else 484 put_child(tp, get_index(key, tp), n); 485 } 486 487 static inline void tnode_free_init(struct key_vector *tn) 488 { 489 tn_info(tn)->rcu.next = NULL; 490 } 491 492 static inline void tnode_free_append(struct key_vector *tn, 493 struct key_vector *n) 494 { 495 tn_info(n)->rcu.next = tn_info(tn)->rcu.next; 496 tn_info(tn)->rcu.next = &tn_info(n)->rcu; 497 } 498 499 static void tnode_free(struct key_vector *tn) 500 { 501 struct callback_head *head = &tn_info(tn)->rcu; 502 503 while (head) { 504 head = head->next; 505 tnode_free_size += TNODE_SIZE(1ul << tn->bits); 506 node_free(tn); 507 508 tn = container_of(head, struct tnode, rcu)->kv; 509 } 510 511 if (tnode_free_size >= PAGE_SIZE * sync_pages) { 512 tnode_free_size = 0; 513 synchronize_rcu(); 514 } 515 } 516 517 static struct key_vector *replace(struct trie *t, 518 struct key_vector *oldtnode, 519 struct key_vector *tn) 520 { 521 struct key_vector *tp = node_parent(oldtnode); 522 unsigned long i; 523 524 /* setup the parent pointer out of and back into this node */ 525 NODE_INIT_PARENT(tn, tp); 526 put_child_root(tp, tn->key, tn); 527 528 /* update all of the child parent pointers */ 529 update_children(tn); 530 531 /* all pointers should be clean so we are done */ 532 tnode_free(oldtnode); 533 534 /* resize children now that oldtnode is freed */ 535 for (i = child_length(tn); i;) { 536 struct key_vector *inode = get_child(tn, --i); 537 538 /* resize child node */ 539 if (tnode_full(tn, inode)) 540 tn = resize(t, inode); 541 } 542 543 return tp; 544 } 545 546 static struct key_vector *inflate(struct trie *t, 547 struct key_vector *oldtnode) 548 { 549 struct key_vector *tn; 550 unsigned long i; 551 t_key m; 552 553 pr_debug("In inflate\n"); 554 555 tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1); 556 if (!tn) 557 goto notnode; 558 559 /* prepare oldtnode to be freed */ 560 tnode_free_init(oldtnode); 561 562 /* Assemble all of the pointers in our cluster, in this case that 563 * represents all of the pointers out of our allocated nodes that 564 * point to existing tnodes and the links between our allocated 565 * nodes. 566 */ 567 for (i = child_length(oldtnode), m = 1u << tn->pos; i;) { 568 struct key_vector *inode = get_child(oldtnode, --i); 569 struct key_vector *node0, *node1; 570 unsigned long j, k; 571 572 /* An empty child */ 573 if (!inode) 574 continue; 575 576 /* A leaf or an internal node with skipped bits */ 577 if (!tnode_full(oldtnode, inode)) { 578 put_child(tn, get_index(inode->key, tn), inode); 579 continue; 580 } 581 582 /* drop the node in the old tnode free list */ 583 tnode_free_append(oldtnode, inode); 584 585 /* An internal node with two children */ 586 if (inode->bits == 1) { 587 put_child(tn, 2 * i + 1, get_child(inode, 1)); 588 put_child(tn, 2 * i, get_child(inode, 0)); 589 continue; 590 } 591 592 /* We will replace this node 'inode' with two new 593 * ones, 'node0' and 'node1', each with half of the 594 * original children. The two new nodes will have 595 * a position one bit further down the key and this 596 * means that the "significant" part of their keys 597 * (see the discussion near the top of this file) 598 * will differ by one bit, which will be "0" in 599 * node0's key and "1" in node1's key. Since we are 600 * moving the key position by one step, the bit that 601 * we are moving away from - the bit at position 602 * (tn->pos) - is the one that will differ between 603 * node0 and node1. So... we synthesize that bit in the 604 * two new keys. 605 */ 606 node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1); 607 if (!node1) 608 goto nomem; 609 node0 = tnode_new(inode->key, inode->pos, inode->bits - 1); 610 611 tnode_free_append(tn, node1); 612 if (!node0) 613 goto nomem; 614 tnode_free_append(tn, node0); 615 616 /* populate child pointers in new nodes */ 617 for (k = child_length(inode), j = k / 2; j;) { 618 put_child(node1, --j, get_child(inode, --k)); 619 put_child(node0, j, get_child(inode, j)); 620 put_child(node1, --j, get_child(inode, --k)); 621 put_child(node0, j, get_child(inode, j)); 622 } 623 624 /* link new nodes to parent */ 625 NODE_INIT_PARENT(node1, tn); 626 NODE_INIT_PARENT(node0, tn); 627 628 /* link parent to nodes */ 629 put_child(tn, 2 * i + 1, node1); 630 put_child(tn, 2 * i, node0); 631 } 632 633 /* setup the parent pointers into and out of this node */ 634 return replace(t, oldtnode, tn); 635 nomem: 636 /* all pointers should be clean so we are done */ 637 tnode_free(tn); 638 notnode: 639 return NULL; 640 } 641 642 static struct key_vector *halve(struct trie *t, 643 struct key_vector *oldtnode) 644 { 645 struct key_vector *tn; 646 unsigned long i; 647 648 pr_debug("In halve\n"); 649 650 tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1); 651 if (!tn) 652 goto notnode; 653 654 /* prepare oldtnode to be freed */ 655 tnode_free_init(oldtnode); 656 657 /* Assemble all of the pointers in our cluster, in this case that 658 * represents all of the pointers out of our allocated nodes that 659 * point to existing tnodes and the links between our allocated 660 * nodes. 661 */ 662 for (i = child_length(oldtnode); i;) { 663 struct key_vector *node1 = get_child(oldtnode, --i); 664 struct key_vector *node0 = get_child(oldtnode, --i); 665 struct key_vector *inode; 666 667 /* At least one of the children is empty */ 668 if (!node1 || !node0) { 669 put_child(tn, i / 2, node1 ? : node0); 670 continue; 671 } 672 673 /* Two nonempty children */ 674 inode = tnode_new(node0->key, oldtnode->pos, 1); 675 if (!inode) 676 goto nomem; 677 tnode_free_append(tn, inode); 678 679 /* initialize pointers out of node */ 680 put_child(inode, 1, node1); 681 put_child(inode, 0, node0); 682 NODE_INIT_PARENT(inode, tn); 683 684 /* link parent to node */ 685 put_child(tn, i / 2, inode); 686 } 687 688 /* setup the parent pointers into and out of this node */ 689 return replace(t, oldtnode, tn); 690 nomem: 691 /* all pointers should be clean so we are done */ 692 tnode_free(tn); 693 notnode: 694 return NULL; 695 } 696 697 static struct key_vector *collapse(struct trie *t, 698 struct key_vector *oldtnode) 699 { 700 struct key_vector *n, *tp; 701 unsigned long i; 702 703 /* scan the tnode looking for that one child that might still exist */ 704 for (n = NULL, i = child_length(oldtnode); !n && i;) 705 n = get_child(oldtnode, --i); 706 707 /* compress one level */ 708 tp = node_parent(oldtnode); 709 put_child_root(tp, oldtnode->key, n); 710 node_set_parent(n, tp); 711 712 /* drop dead node */ 713 node_free(oldtnode); 714 715 return tp; 716 } 717 718 static unsigned char update_suffix(struct key_vector *tn) 719 { 720 unsigned char slen = tn->pos; 721 unsigned long stride, i; 722 723 /* search though the list of children looking for nodes that might 724 * have a suffix greater than the one we currently have. This is 725 * why we start with a stride of 2 since a stride of 1 would 726 * represent the nodes with suffix length equal to tn->pos 727 */ 728 for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) { 729 struct key_vector *n = get_child(tn, i); 730 731 if (!n || (n->slen <= slen)) 732 continue; 733 734 /* update stride and slen based on new value */ 735 stride <<= (n->slen - slen); 736 slen = n->slen; 737 i &= ~(stride - 1); 738 739 /* if slen covers all but the last bit we can stop here 740 * there will be nothing longer than that since only node 741 * 0 and 1 << (bits - 1) could have that as their suffix 742 * length. 743 */ 744 if ((slen + 1) >= (tn->pos + tn->bits)) 745 break; 746 } 747 748 tn->slen = slen; 749 750 return slen; 751 } 752 753 /* From "Implementing a dynamic compressed trie" by Stefan Nilsson of 754 * the Helsinki University of Technology and Matti Tikkanen of Nokia 755 * Telecommunications, page 6: 756 * "A node is doubled if the ratio of non-empty children to all 757 * children in the *doubled* node is at least 'high'." 758 * 759 * 'high' in this instance is the variable 'inflate_threshold'. It 760 * is expressed as a percentage, so we multiply it with 761 * child_length() and instead of multiplying by 2 (since the 762 * child array will be doubled by inflate()) and multiplying 763 * the left-hand side by 100 (to handle the percentage thing) we 764 * multiply the left-hand side by 50. 765 * 766 * The left-hand side may look a bit weird: child_length(tn) 767 * - tn->empty_children is of course the number of non-null children 768 * in the current node. tn->full_children is the number of "full" 769 * children, that is non-null tnodes with a skip value of 0. 770 * All of those will be doubled in the resulting inflated tnode, so 771 * we just count them one extra time here. 772 * 773 * A clearer way to write this would be: 774 * 775 * to_be_doubled = tn->full_children; 776 * not_to_be_doubled = child_length(tn) - tn->empty_children - 777 * tn->full_children; 778 * 779 * new_child_length = child_length(tn) * 2; 780 * 781 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) / 782 * new_child_length; 783 * if (new_fill_factor >= inflate_threshold) 784 * 785 * ...and so on, tho it would mess up the while () loop. 786 * 787 * anyway, 788 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >= 789 * inflate_threshold 790 * 791 * avoid a division: 792 * 100 * (not_to_be_doubled + 2*to_be_doubled) >= 793 * inflate_threshold * new_child_length 794 * 795 * expand not_to_be_doubled and to_be_doubled, and shorten: 796 * 100 * (child_length(tn) - tn->empty_children + 797 * tn->full_children) >= inflate_threshold * new_child_length 798 * 799 * expand new_child_length: 800 * 100 * (child_length(tn) - tn->empty_children + 801 * tn->full_children) >= 802 * inflate_threshold * child_length(tn) * 2 803 * 804 * shorten again: 805 * 50 * (tn->full_children + child_length(tn) - 806 * tn->empty_children) >= inflate_threshold * 807 * child_length(tn) 808 * 809 */ 810 static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn) 811 { 812 unsigned long used = child_length(tn); 813 unsigned long threshold = used; 814 815 /* Keep root node larger */ 816 threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold; 817 used -= tn_info(tn)->empty_children; 818 used += tn_info(tn)->full_children; 819 820 /* if bits == KEYLENGTH then pos = 0, and will fail below */ 821 822 return (used > 1) && tn->pos && ((50 * used) >= threshold); 823 } 824 825 static inline bool should_halve(struct key_vector *tp, struct key_vector *tn) 826 { 827 unsigned long used = child_length(tn); 828 unsigned long threshold = used; 829 830 /* Keep root node larger */ 831 threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold; 832 used -= tn_info(tn)->empty_children; 833 834 /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */ 835 836 return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold); 837 } 838 839 static inline bool should_collapse(struct key_vector *tn) 840 { 841 unsigned long used = child_length(tn); 842 843 used -= tn_info(tn)->empty_children; 844 845 /* account for bits == KEYLENGTH case */ 846 if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children) 847 used -= KEY_MAX; 848 849 /* One child or none, time to drop us from the trie */ 850 return used < 2; 851 } 852 853 #define MAX_WORK 10 854 static struct key_vector *resize(struct trie *t, struct key_vector *tn) 855 { 856 #ifdef CONFIG_IP_FIB_TRIE_STATS 857 struct trie_use_stats __percpu *stats = t->stats; 858 #endif 859 struct key_vector *tp = node_parent(tn); 860 unsigned long cindex = get_index(tn->key, tp); 861 int max_work = MAX_WORK; 862 863 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n", 864 tn, inflate_threshold, halve_threshold); 865 866 /* track the tnode via the pointer from the parent instead of 867 * doing it ourselves. This way we can let RCU fully do its 868 * thing without us interfering 869 */ 870 BUG_ON(tn != get_child(tp, cindex)); 871 872 /* Double as long as the resulting node has a number of 873 * nonempty nodes that are above the threshold. 874 */ 875 while (should_inflate(tp, tn) && max_work) { 876 tp = inflate(t, tn); 877 if (!tp) { 878 #ifdef CONFIG_IP_FIB_TRIE_STATS 879 this_cpu_inc(stats->resize_node_skipped); 880 #endif 881 break; 882 } 883 884 max_work--; 885 tn = get_child(tp, cindex); 886 } 887 888 /* update parent in case inflate failed */ 889 tp = node_parent(tn); 890 891 /* Return if at least one inflate is run */ 892 if (max_work != MAX_WORK) 893 return tp; 894 895 /* Halve as long as the number of empty children in this 896 * node is above threshold. 897 */ 898 while (should_halve(tp, tn) && max_work) { 899 tp = halve(t, tn); 900 if (!tp) { 901 #ifdef CONFIG_IP_FIB_TRIE_STATS 902 this_cpu_inc(stats->resize_node_skipped); 903 #endif 904 break; 905 } 906 907 max_work--; 908 tn = get_child(tp, cindex); 909 } 910 911 /* Only one child remains */ 912 if (should_collapse(tn)) 913 return collapse(t, tn); 914 915 /* update parent in case halve failed */ 916 tp = node_parent(tn); 917 918 /* Return if at least one deflate was run */ 919 if (max_work != MAX_WORK) 920 return tp; 921 922 /* push the suffix length to the parent node */ 923 if (tn->slen > tn->pos) { 924 unsigned char slen = update_suffix(tn); 925 926 if (slen > tp->slen) 927 tp->slen = slen; 928 } 929 930 return tp; 931 } 932 933 static void leaf_pull_suffix(struct key_vector *tp, struct key_vector *l) 934 { 935 while ((tp->slen > tp->pos) && (tp->slen > l->slen)) { 936 if (update_suffix(tp) > l->slen) 937 break; 938 tp = node_parent(tp); 939 } 940 } 941 942 static void leaf_push_suffix(struct key_vector *tn, struct key_vector *l) 943 { 944 /* if this is a new leaf then tn will be NULL and we can sort 945 * out parent suffix lengths as a part of trie_rebalance 946 */ 947 while (tn->slen < l->slen) { 948 tn->slen = l->slen; 949 tn = node_parent(tn); 950 } 951 } 952 953 /* rcu_read_lock needs to be hold by caller from readside */ 954 static struct key_vector *fib_find_node(struct trie *t, 955 struct key_vector **tp, u32 key) 956 { 957 struct key_vector *pn, *n = t->kv; 958 unsigned long index = 0; 959 960 do { 961 pn = n; 962 n = get_child_rcu(n, index); 963 964 if (!n) 965 break; 966 967 index = get_cindex(key, n); 968 969 /* This bit of code is a bit tricky but it combines multiple 970 * checks into a single check. The prefix consists of the 971 * prefix plus zeros for the bits in the cindex. The index 972 * is the difference between the key and this value. From 973 * this we can actually derive several pieces of data. 974 * if (index >= (1ul << bits)) 975 * we have a mismatch in skip bits and failed 976 * else 977 * we know the value is cindex 978 * 979 * This check is safe even if bits == KEYLENGTH due to the 980 * fact that we can only allocate a node with 32 bits if a 981 * long is greater than 32 bits. 982 */ 983 if (index >= (1ul << n->bits)) { 984 n = NULL; 985 break; 986 } 987 988 /* keep searching until we find a perfect match leaf or NULL */ 989 } while (IS_TNODE(n)); 990 991 *tp = pn; 992 993 return n; 994 } 995 996 /* Return the first fib alias matching TOS with 997 * priority less than or equal to PRIO. 998 */ 999 static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen, 1000 u8 tos, u32 prio, u32 tb_id) 1001 { 1002 struct fib_alias *fa; 1003 1004 if (!fah) 1005 return NULL; 1006 1007 hlist_for_each_entry(fa, fah, fa_list) { 1008 if (fa->fa_slen < slen) 1009 continue; 1010 if (fa->fa_slen != slen) 1011 break; 1012 if (fa->tb_id > tb_id) 1013 continue; 1014 if (fa->tb_id != tb_id) 1015 break; 1016 if (fa->fa_tos > tos) 1017 continue; 1018 if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos) 1019 return fa; 1020 } 1021 1022 return NULL; 1023 } 1024 1025 static void trie_rebalance(struct trie *t, struct key_vector *tn) 1026 { 1027 while (!IS_TRIE(tn)) 1028 tn = resize(t, tn); 1029 } 1030 1031 static int fib_insert_node(struct trie *t, struct key_vector *tp, 1032 struct fib_alias *new, t_key key) 1033 { 1034 struct key_vector *n, *l; 1035 1036 l = leaf_new(key, new); 1037 if (!l) 1038 goto noleaf; 1039 1040 /* retrieve child from parent node */ 1041 n = get_child(tp, get_index(key, tp)); 1042 1043 /* Case 2: n is a LEAF or a TNODE and the key doesn't match. 1044 * 1045 * Add a new tnode here 1046 * first tnode need some special handling 1047 * leaves us in position for handling as case 3 1048 */ 1049 if (n) { 1050 struct key_vector *tn; 1051 1052 tn = tnode_new(key, __fls(key ^ n->key), 1); 1053 if (!tn) 1054 goto notnode; 1055 1056 /* initialize routes out of node */ 1057 NODE_INIT_PARENT(tn, tp); 1058 put_child(tn, get_index(key, tn) ^ 1, n); 1059 1060 /* start adding routes into the node */ 1061 put_child_root(tp, key, tn); 1062 node_set_parent(n, tn); 1063 1064 /* parent now has a NULL spot where the leaf can go */ 1065 tp = tn; 1066 } 1067 1068 /* Case 3: n is NULL, and will just insert a new leaf */ 1069 NODE_INIT_PARENT(l, tp); 1070 put_child_root(tp, key, l); 1071 trie_rebalance(t, tp); 1072 1073 return 0; 1074 notnode: 1075 node_free(l); 1076 noleaf: 1077 return -ENOMEM; 1078 } 1079 1080 static int fib_insert_alias(struct trie *t, struct key_vector *tp, 1081 struct key_vector *l, struct fib_alias *new, 1082 struct fib_alias *fa, t_key key) 1083 { 1084 if (!l) 1085 return fib_insert_node(t, tp, new, key); 1086 1087 if (fa) { 1088 hlist_add_before_rcu(&new->fa_list, &fa->fa_list); 1089 } else { 1090 struct fib_alias *last; 1091 1092 hlist_for_each_entry(last, &l->leaf, fa_list) { 1093 if (new->fa_slen < last->fa_slen) 1094 break; 1095 if ((new->fa_slen == last->fa_slen) && 1096 (new->tb_id > last->tb_id)) 1097 break; 1098 fa = last; 1099 } 1100 1101 if (fa) 1102 hlist_add_behind_rcu(&new->fa_list, &fa->fa_list); 1103 else 1104 hlist_add_head_rcu(&new->fa_list, &l->leaf); 1105 } 1106 1107 /* if we added to the tail node then we need to update slen */ 1108 if (l->slen < new->fa_slen) { 1109 l->slen = new->fa_slen; 1110 leaf_push_suffix(tp, l); 1111 } 1112 1113 return 0; 1114 } 1115 1116 /* Caller must hold RTNL. */ 1117 int fib_table_insert(struct net *net, struct fib_table *tb, 1118 struct fib_config *cfg) 1119 { 1120 struct trie *t = (struct trie *)tb->tb_data; 1121 struct fib_alias *fa, *new_fa; 1122 struct key_vector *l, *tp; 1123 u16 nlflags = NLM_F_EXCL; 1124 struct fib_info *fi; 1125 u8 plen = cfg->fc_dst_len; 1126 u8 slen = KEYLENGTH - plen; 1127 u8 tos = cfg->fc_tos; 1128 u32 key; 1129 int err; 1130 1131 if (plen > KEYLENGTH) 1132 return -EINVAL; 1133 1134 key = ntohl(cfg->fc_dst); 1135 1136 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen); 1137 1138 if ((plen < KEYLENGTH) && (key << plen)) 1139 return -EINVAL; 1140 1141 fi = fib_create_info(cfg); 1142 if (IS_ERR(fi)) { 1143 err = PTR_ERR(fi); 1144 goto err; 1145 } 1146 1147 l = fib_find_node(t, &tp, key); 1148 fa = l ? fib_find_alias(&l->leaf, slen, tos, fi->fib_priority, 1149 tb->tb_id) : NULL; 1150 1151 /* Now fa, if non-NULL, points to the first fib alias 1152 * with the same keys [prefix,tos,priority], if such key already 1153 * exists or to the node before which we will insert new one. 1154 * 1155 * If fa is NULL, we will need to allocate a new one and 1156 * insert to the tail of the section matching the suffix length 1157 * of the new alias. 1158 */ 1159 1160 if (fa && fa->fa_tos == tos && 1161 fa->fa_info->fib_priority == fi->fib_priority) { 1162 struct fib_alias *fa_first, *fa_match; 1163 1164 err = -EEXIST; 1165 if (cfg->fc_nlflags & NLM_F_EXCL) 1166 goto out; 1167 1168 nlflags &= ~NLM_F_EXCL; 1169 1170 /* We have 2 goals: 1171 * 1. Find exact match for type, scope, fib_info to avoid 1172 * duplicate routes 1173 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it 1174 */ 1175 fa_match = NULL; 1176 fa_first = fa; 1177 hlist_for_each_entry_from(fa, fa_list) { 1178 if ((fa->fa_slen != slen) || 1179 (fa->tb_id != tb->tb_id) || 1180 (fa->fa_tos != tos)) 1181 break; 1182 if (fa->fa_info->fib_priority != fi->fib_priority) 1183 break; 1184 if (fa->fa_type == cfg->fc_type && 1185 fa->fa_info == fi) { 1186 fa_match = fa; 1187 break; 1188 } 1189 } 1190 1191 if (cfg->fc_nlflags & NLM_F_REPLACE) { 1192 struct fib_info *fi_drop; 1193 u8 state; 1194 1195 nlflags |= NLM_F_REPLACE; 1196 fa = fa_first; 1197 if (fa_match) { 1198 if (fa == fa_match) 1199 err = 0; 1200 goto out; 1201 } 1202 err = -ENOBUFS; 1203 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1204 if (!new_fa) 1205 goto out; 1206 1207 fi_drop = fa->fa_info; 1208 new_fa->fa_tos = fa->fa_tos; 1209 new_fa->fa_info = fi; 1210 new_fa->fa_type = cfg->fc_type; 1211 state = fa->fa_state; 1212 new_fa->fa_state = state & ~FA_S_ACCESSED; 1213 new_fa->fa_slen = fa->fa_slen; 1214 new_fa->tb_id = tb->tb_id; 1215 new_fa->fa_default = -1; 1216 1217 hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list); 1218 1219 alias_free_mem_rcu(fa); 1220 1221 fib_release_info(fi_drop); 1222 if (state & FA_S_ACCESSED) 1223 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1224 1225 call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_ADD, 1226 key, plen, fi, 1227 new_fa->fa_tos, cfg->fc_type, 1228 tb->tb_id, cfg->fc_nlflags); 1229 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, 1230 tb->tb_id, &cfg->fc_nlinfo, nlflags); 1231 1232 goto succeeded; 1233 } 1234 /* Error if we find a perfect match which 1235 * uses the same scope, type, and nexthop 1236 * information. 1237 */ 1238 if (fa_match) 1239 goto out; 1240 1241 if (cfg->fc_nlflags & NLM_F_APPEND) 1242 nlflags |= NLM_F_APPEND; 1243 else 1244 fa = fa_first; 1245 } 1246 err = -ENOENT; 1247 if (!(cfg->fc_nlflags & NLM_F_CREATE)) 1248 goto out; 1249 1250 nlflags |= NLM_F_CREATE; 1251 err = -ENOBUFS; 1252 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1253 if (!new_fa) 1254 goto out; 1255 1256 new_fa->fa_info = fi; 1257 new_fa->fa_tos = tos; 1258 new_fa->fa_type = cfg->fc_type; 1259 new_fa->fa_state = 0; 1260 new_fa->fa_slen = slen; 1261 new_fa->tb_id = tb->tb_id; 1262 new_fa->fa_default = -1; 1263 1264 /* Insert new entry to the list. */ 1265 err = fib_insert_alias(t, tp, l, new_fa, fa, key); 1266 if (err) 1267 goto out_free_new_fa; 1268 1269 if (!plen) 1270 tb->tb_num_default++; 1271 1272 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1273 call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_ADD, key, plen, fi, tos, 1274 cfg->fc_type, tb->tb_id, cfg->fc_nlflags); 1275 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id, 1276 &cfg->fc_nlinfo, nlflags); 1277 succeeded: 1278 return 0; 1279 1280 out_free_new_fa: 1281 kmem_cache_free(fn_alias_kmem, new_fa); 1282 out: 1283 fib_release_info(fi); 1284 err: 1285 return err; 1286 } 1287 1288 static inline t_key prefix_mismatch(t_key key, struct key_vector *n) 1289 { 1290 t_key prefix = n->key; 1291 1292 return (key ^ prefix) & (prefix | -prefix); 1293 } 1294 1295 /* should be called with rcu_read_lock */ 1296 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 1297 struct fib_result *res, int fib_flags) 1298 { 1299 struct trie *t = (struct trie *) tb->tb_data; 1300 #ifdef CONFIG_IP_FIB_TRIE_STATS 1301 struct trie_use_stats __percpu *stats = t->stats; 1302 #endif 1303 const t_key key = ntohl(flp->daddr); 1304 struct key_vector *n, *pn; 1305 struct fib_alias *fa; 1306 unsigned long index; 1307 t_key cindex; 1308 1309 trace_fib_table_lookup(tb->tb_id, flp); 1310 1311 pn = t->kv; 1312 cindex = 0; 1313 1314 n = get_child_rcu(pn, cindex); 1315 if (!n) 1316 return -EAGAIN; 1317 1318 #ifdef CONFIG_IP_FIB_TRIE_STATS 1319 this_cpu_inc(stats->gets); 1320 #endif 1321 1322 /* Step 1: Travel to the longest prefix match in the trie */ 1323 for (;;) { 1324 index = get_cindex(key, n); 1325 1326 /* This bit of code is a bit tricky but it combines multiple 1327 * checks into a single check. The prefix consists of the 1328 * prefix plus zeros for the "bits" in the prefix. The index 1329 * is the difference between the key and this value. From 1330 * this we can actually derive several pieces of data. 1331 * if (index >= (1ul << bits)) 1332 * we have a mismatch in skip bits and failed 1333 * else 1334 * we know the value is cindex 1335 * 1336 * This check is safe even if bits == KEYLENGTH due to the 1337 * fact that we can only allocate a node with 32 bits if a 1338 * long is greater than 32 bits. 1339 */ 1340 if (index >= (1ul << n->bits)) 1341 break; 1342 1343 /* we have found a leaf. Prefixes have already been compared */ 1344 if (IS_LEAF(n)) 1345 goto found; 1346 1347 /* only record pn and cindex if we are going to be chopping 1348 * bits later. Otherwise we are just wasting cycles. 1349 */ 1350 if (n->slen > n->pos) { 1351 pn = n; 1352 cindex = index; 1353 } 1354 1355 n = get_child_rcu(n, index); 1356 if (unlikely(!n)) 1357 goto backtrace; 1358 } 1359 1360 /* Step 2: Sort out leaves and begin backtracing for longest prefix */ 1361 for (;;) { 1362 /* record the pointer where our next node pointer is stored */ 1363 struct key_vector __rcu **cptr = n->tnode; 1364 1365 /* This test verifies that none of the bits that differ 1366 * between the key and the prefix exist in the region of 1367 * the lsb and higher in the prefix. 1368 */ 1369 if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos)) 1370 goto backtrace; 1371 1372 /* exit out and process leaf */ 1373 if (unlikely(IS_LEAF(n))) 1374 break; 1375 1376 /* Don't bother recording parent info. Since we are in 1377 * prefix match mode we will have to come back to wherever 1378 * we started this traversal anyway 1379 */ 1380 1381 while ((n = rcu_dereference(*cptr)) == NULL) { 1382 backtrace: 1383 #ifdef CONFIG_IP_FIB_TRIE_STATS 1384 if (!n) 1385 this_cpu_inc(stats->null_node_hit); 1386 #endif 1387 /* If we are at cindex 0 there are no more bits for 1388 * us to strip at this level so we must ascend back 1389 * up one level to see if there are any more bits to 1390 * be stripped there. 1391 */ 1392 while (!cindex) { 1393 t_key pkey = pn->key; 1394 1395 /* If we don't have a parent then there is 1396 * nothing for us to do as we do not have any 1397 * further nodes to parse. 1398 */ 1399 if (IS_TRIE(pn)) 1400 return -EAGAIN; 1401 #ifdef CONFIG_IP_FIB_TRIE_STATS 1402 this_cpu_inc(stats->backtrack); 1403 #endif 1404 /* Get Child's index */ 1405 pn = node_parent_rcu(pn); 1406 cindex = get_index(pkey, pn); 1407 } 1408 1409 /* strip the least significant bit from the cindex */ 1410 cindex &= cindex - 1; 1411 1412 /* grab pointer for next child node */ 1413 cptr = &pn->tnode[cindex]; 1414 } 1415 } 1416 1417 found: 1418 /* this line carries forward the xor from earlier in the function */ 1419 index = key ^ n->key; 1420 1421 /* Step 3: Process the leaf, if that fails fall back to backtracing */ 1422 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) { 1423 struct fib_info *fi = fa->fa_info; 1424 int nhsel, err; 1425 1426 if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) { 1427 if (index >= (1ul << fa->fa_slen)) 1428 continue; 1429 } 1430 if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos) 1431 continue; 1432 if (fi->fib_dead) 1433 continue; 1434 if (fa->fa_info->fib_scope < flp->flowi4_scope) 1435 continue; 1436 fib_alias_accessed(fa); 1437 err = fib_props[fa->fa_type].error; 1438 if (unlikely(err < 0)) { 1439 #ifdef CONFIG_IP_FIB_TRIE_STATS 1440 this_cpu_inc(stats->semantic_match_passed); 1441 #endif 1442 return err; 1443 } 1444 if (fi->fib_flags & RTNH_F_DEAD) 1445 continue; 1446 for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) { 1447 const struct fib_nh *nh = &fi->fib_nh[nhsel]; 1448 struct in_device *in_dev = __in_dev_get_rcu(nh->nh_dev); 1449 1450 if (nh->nh_flags & RTNH_F_DEAD) 1451 continue; 1452 if (in_dev && 1453 IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) && 1454 nh->nh_flags & RTNH_F_LINKDOWN && 1455 !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE)) 1456 continue; 1457 if (!(flp->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) { 1458 if (flp->flowi4_oif && 1459 flp->flowi4_oif != nh->nh_oif) 1460 continue; 1461 } 1462 1463 if (!(fib_flags & FIB_LOOKUP_NOREF)) 1464 atomic_inc(&fi->fib_clntref); 1465 1466 res->prefixlen = KEYLENGTH - fa->fa_slen; 1467 res->nh_sel = nhsel; 1468 res->type = fa->fa_type; 1469 res->scope = fi->fib_scope; 1470 res->fi = fi; 1471 res->table = tb; 1472 res->fa_head = &n->leaf; 1473 #ifdef CONFIG_IP_FIB_TRIE_STATS 1474 this_cpu_inc(stats->semantic_match_passed); 1475 #endif 1476 trace_fib_table_lookup_nh(nh); 1477 1478 return err; 1479 } 1480 } 1481 #ifdef CONFIG_IP_FIB_TRIE_STATS 1482 this_cpu_inc(stats->semantic_match_miss); 1483 #endif 1484 goto backtrace; 1485 } 1486 EXPORT_SYMBOL_GPL(fib_table_lookup); 1487 1488 static void fib_remove_alias(struct trie *t, struct key_vector *tp, 1489 struct key_vector *l, struct fib_alias *old) 1490 { 1491 /* record the location of the previous list_info entry */ 1492 struct hlist_node **pprev = old->fa_list.pprev; 1493 struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next); 1494 1495 /* remove the fib_alias from the list */ 1496 hlist_del_rcu(&old->fa_list); 1497 1498 /* if we emptied the list this leaf will be freed and we can sort 1499 * out parent suffix lengths as a part of trie_rebalance 1500 */ 1501 if (hlist_empty(&l->leaf)) { 1502 put_child_root(tp, l->key, NULL); 1503 node_free(l); 1504 trie_rebalance(t, tp); 1505 return; 1506 } 1507 1508 /* only access fa if it is pointing at the last valid hlist_node */ 1509 if (*pprev) 1510 return; 1511 1512 /* update the trie with the latest suffix length */ 1513 l->slen = fa->fa_slen; 1514 leaf_pull_suffix(tp, l); 1515 } 1516 1517 /* Caller must hold RTNL. */ 1518 int fib_table_delete(struct net *net, struct fib_table *tb, 1519 struct fib_config *cfg) 1520 { 1521 struct trie *t = (struct trie *) tb->tb_data; 1522 struct fib_alias *fa, *fa_to_delete; 1523 struct key_vector *l, *tp; 1524 u8 plen = cfg->fc_dst_len; 1525 u8 slen = KEYLENGTH - plen; 1526 u8 tos = cfg->fc_tos; 1527 u32 key; 1528 1529 if (plen > KEYLENGTH) 1530 return -EINVAL; 1531 1532 key = ntohl(cfg->fc_dst); 1533 1534 if ((plen < KEYLENGTH) && (key << plen)) 1535 return -EINVAL; 1536 1537 l = fib_find_node(t, &tp, key); 1538 if (!l) 1539 return -ESRCH; 1540 1541 fa = fib_find_alias(&l->leaf, slen, tos, 0, tb->tb_id); 1542 if (!fa) 1543 return -ESRCH; 1544 1545 pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t); 1546 1547 fa_to_delete = NULL; 1548 hlist_for_each_entry_from(fa, fa_list) { 1549 struct fib_info *fi = fa->fa_info; 1550 1551 if ((fa->fa_slen != slen) || 1552 (fa->tb_id != tb->tb_id) || 1553 (fa->fa_tos != tos)) 1554 break; 1555 1556 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) && 1557 (cfg->fc_scope == RT_SCOPE_NOWHERE || 1558 fa->fa_info->fib_scope == cfg->fc_scope) && 1559 (!cfg->fc_prefsrc || 1560 fi->fib_prefsrc == cfg->fc_prefsrc) && 1561 (!cfg->fc_protocol || 1562 fi->fib_protocol == cfg->fc_protocol) && 1563 fib_nh_match(cfg, fi) == 0) { 1564 fa_to_delete = fa; 1565 break; 1566 } 1567 } 1568 1569 if (!fa_to_delete) 1570 return -ESRCH; 1571 1572 call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, key, plen, 1573 fa_to_delete->fa_info, tos, cfg->fc_type, 1574 tb->tb_id, 0); 1575 rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id, 1576 &cfg->fc_nlinfo, 0); 1577 1578 if (!plen) 1579 tb->tb_num_default--; 1580 1581 fib_remove_alias(t, tp, l, fa_to_delete); 1582 1583 if (fa_to_delete->fa_state & FA_S_ACCESSED) 1584 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1585 1586 fib_release_info(fa_to_delete->fa_info); 1587 alias_free_mem_rcu(fa_to_delete); 1588 return 0; 1589 } 1590 1591 /* Scan for the next leaf starting at the provided key value */ 1592 static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key) 1593 { 1594 struct key_vector *pn, *n = *tn; 1595 unsigned long cindex; 1596 1597 /* this loop is meant to try and find the key in the trie */ 1598 do { 1599 /* record parent and next child index */ 1600 pn = n; 1601 cindex = (key > pn->key) ? get_index(key, pn) : 0; 1602 1603 if (cindex >> pn->bits) 1604 break; 1605 1606 /* descend into the next child */ 1607 n = get_child_rcu(pn, cindex++); 1608 if (!n) 1609 break; 1610 1611 /* guarantee forward progress on the keys */ 1612 if (IS_LEAF(n) && (n->key >= key)) 1613 goto found; 1614 } while (IS_TNODE(n)); 1615 1616 /* this loop will search for the next leaf with a greater key */ 1617 while (!IS_TRIE(pn)) { 1618 /* if we exhausted the parent node we will need to climb */ 1619 if (cindex >= (1ul << pn->bits)) { 1620 t_key pkey = pn->key; 1621 1622 pn = node_parent_rcu(pn); 1623 cindex = get_index(pkey, pn) + 1; 1624 continue; 1625 } 1626 1627 /* grab the next available node */ 1628 n = get_child_rcu(pn, cindex++); 1629 if (!n) 1630 continue; 1631 1632 /* no need to compare keys since we bumped the index */ 1633 if (IS_LEAF(n)) 1634 goto found; 1635 1636 /* Rescan start scanning in new node */ 1637 pn = n; 1638 cindex = 0; 1639 } 1640 1641 *tn = pn; 1642 return NULL; /* Root of trie */ 1643 found: 1644 /* if we are at the limit for keys just return NULL for the tnode */ 1645 *tn = pn; 1646 return n; 1647 } 1648 1649 static void fib_trie_free(struct fib_table *tb) 1650 { 1651 struct trie *t = (struct trie *)tb->tb_data; 1652 struct key_vector *pn = t->kv; 1653 unsigned long cindex = 1; 1654 struct hlist_node *tmp; 1655 struct fib_alias *fa; 1656 1657 /* walk trie in reverse order and free everything */ 1658 for (;;) { 1659 struct key_vector *n; 1660 1661 if (!(cindex--)) { 1662 t_key pkey = pn->key; 1663 1664 if (IS_TRIE(pn)) 1665 break; 1666 1667 n = pn; 1668 pn = node_parent(pn); 1669 1670 /* drop emptied tnode */ 1671 put_child_root(pn, n->key, NULL); 1672 node_free(n); 1673 1674 cindex = get_index(pkey, pn); 1675 1676 continue; 1677 } 1678 1679 /* grab the next available node */ 1680 n = get_child(pn, cindex); 1681 if (!n) 1682 continue; 1683 1684 if (IS_TNODE(n)) { 1685 /* record pn and cindex for leaf walking */ 1686 pn = n; 1687 cindex = 1ul << n->bits; 1688 1689 continue; 1690 } 1691 1692 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 1693 hlist_del_rcu(&fa->fa_list); 1694 alias_free_mem_rcu(fa); 1695 } 1696 1697 put_child_root(pn, n->key, NULL); 1698 node_free(n); 1699 } 1700 1701 #ifdef CONFIG_IP_FIB_TRIE_STATS 1702 free_percpu(t->stats); 1703 #endif 1704 kfree(tb); 1705 } 1706 1707 struct fib_table *fib_trie_unmerge(struct fib_table *oldtb) 1708 { 1709 struct trie *ot = (struct trie *)oldtb->tb_data; 1710 struct key_vector *l, *tp = ot->kv; 1711 struct fib_table *local_tb; 1712 struct fib_alias *fa; 1713 struct trie *lt; 1714 t_key key = 0; 1715 1716 if (oldtb->tb_data == oldtb->__data) 1717 return oldtb; 1718 1719 local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL); 1720 if (!local_tb) 1721 return NULL; 1722 1723 lt = (struct trie *)local_tb->tb_data; 1724 1725 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 1726 struct key_vector *local_l = NULL, *local_tp; 1727 1728 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 1729 struct fib_alias *new_fa; 1730 1731 if (local_tb->tb_id != fa->tb_id) 1732 continue; 1733 1734 /* clone fa for new local table */ 1735 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1736 if (!new_fa) 1737 goto out; 1738 1739 memcpy(new_fa, fa, sizeof(*fa)); 1740 1741 /* insert clone into table */ 1742 if (!local_l) 1743 local_l = fib_find_node(lt, &local_tp, l->key); 1744 1745 if (fib_insert_alias(lt, local_tp, local_l, new_fa, 1746 NULL, l->key)) 1747 goto out; 1748 } 1749 1750 /* stop loop if key wrapped back to 0 */ 1751 key = l->key + 1; 1752 if (key < l->key) 1753 break; 1754 } 1755 1756 return local_tb; 1757 out: 1758 fib_trie_free(local_tb); 1759 1760 return NULL; 1761 } 1762 1763 /* Caller must hold RTNL. */ 1764 int fib_table_flush(struct net *net, struct fib_table *tb) 1765 { 1766 struct trie *t = (struct trie *)tb->tb_data; 1767 struct key_vector *pn = t->kv; 1768 unsigned long cindex = 1; 1769 struct hlist_node *tmp; 1770 struct fib_alias *fa; 1771 int found = 0; 1772 1773 /* walk trie in reverse order */ 1774 for (;;) { 1775 unsigned char slen = 0; 1776 struct key_vector *n; 1777 1778 if (!(cindex--)) { 1779 t_key pkey = pn->key; 1780 1781 /* cannot resize the trie vector */ 1782 if (IS_TRIE(pn)) 1783 break; 1784 1785 /* resize completed node */ 1786 pn = resize(t, pn); 1787 cindex = get_index(pkey, pn); 1788 1789 continue; 1790 } 1791 1792 /* grab the next available node */ 1793 n = get_child(pn, cindex); 1794 if (!n) 1795 continue; 1796 1797 if (IS_TNODE(n)) { 1798 /* record pn and cindex for leaf walking */ 1799 pn = n; 1800 cindex = 1ul << n->bits; 1801 1802 continue; 1803 } 1804 1805 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 1806 struct fib_info *fi = fa->fa_info; 1807 1808 if (!fi || !(fi->fib_flags & RTNH_F_DEAD)) { 1809 slen = fa->fa_slen; 1810 continue; 1811 } 1812 1813 call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, 1814 n->key, 1815 KEYLENGTH - fa->fa_slen, 1816 fi, fa->fa_tos, fa->fa_type, 1817 tb->tb_id, 0); 1818 hlist_del_rcu(&fa->fa_list); 1819 fib_release_info(fa->fa_info); 1820 alias_free_mem_rcu(fa); 1821 found++; 1822 } 1823 1824 /* update leaf slen */ 1825 n->slen = slen; 1826 1827 if (hlist_empty(&n->leaf)) { 1828 put_child_root(pn, n->key, NULL); 1829 node_free(n); 1830 } 1831 } 1832 1833 pr_debug("trie_flush found=%d\n", found); 1834 return found; 1835 } 1836 1837 static void __trie_free_rcu(struct rcu_head *head) 1838 { 1839 struct fib_table *tb = container_of(head, struct fib_table, rcu); 1840 #ifdef CONFIG_IP_FIB_TRIE_STATS 1841 struct trie *t = (struct trie *)tb->tb_data; 1842 1843 if (tb->tb_data == tb->__data) 1844 free_percpu(t->stats); 1845 #endif /* CONFIG_IP_FIB_TRIE_STATS */ 1846 kfree(tb); 1847 } 1848 1849 void fib_free_table(struct fib_table *tb) 1850 { 1851 call_rcu(&tb->rcu, __trie_free_rcu); 1852 } 1853 1854 static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb, 1855 struct sk_buff *skb, struct netlink_callback *cb) 1856 { 1857 __be32 xkey = htonl(l->key); 1858 struct fib_alias *fa; 1859 int i, s_i; 1860 1861 s_i = cb->args[4]; 1862 i = 0; 1863 1864 /* rcu_read_lock is hold by caller */ 1865 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 1866 if (i < s_i) { 1867 i++; 1868 continue; 1869 } 1870 1871 if (tb->tb_id != fa->tb_id) { 1872 i++; 1873 continue; 1874 } 1875 1876 if (fib_dump_info(skb, NETLINK_CB(cb->skb).portid, 1877 cb->nlh->nlmsg_seq, 1878 RTM_NEWROUTE, 1879 tb->tb_id, 1880 fa->fa_type, 1881 xkey, 1882 KEYLENGTH - fa->fa_slen, 1883 fa->fa_tos, 1884 fa->fa_info, NLM_F_MULTI) < 0) { 1885 cb->args[4] = i; 1886 return -1; 1887 } 1888 i++; 1889 } 1890 1891 cb->args[4] = i; 1892 return skb->len; 1893 } 1894 1895 /* rcu_read_lock needs to be hold by caller from readside */ 1896 int fib_table_dump(struct fib_table *tb, struct sk_buff *skb, 1897 struct netlink_callback *cb) 1898 { 1899 struct trie *t = (struct trie *)tb->tb_data; 1900 struct key_vector *l, *tp = t->kv; 1901 /* Dump starting at last key. 1902 * Note: 0.0.0.0/0 (ie default) is first key. 1903 */ 1904 int count = cb->args[2]; 1905 t_key key = cb->args[3]; 1906 1907 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 1908 if (fn_trie_dump_leaf(l, tb, skb, cb) < 0) { 1909 cb->args[3] = key; 1910 cb->args[2] = count; 1911 return -1; 1912 } 1913 1914 ++count; 1915 key = l->key + 1; 1916 1917 memset(&cb->args[4], 0, 1918 sizeof(cb->args) - 4*sizeof(cb->args[0])); 1919 1920 /* stop loop if key wrapped back to 0 */ 1921 if (key < l->key) 1922 break; 1923 } 1924 1925 cb->args[3] = key; 1926 cb->args[2] = count; 1927 1928 return skb->len; 1929 } 1930 1931 void __init fib_trie_init(void) 1932 { 1933 fn_alias_kmem = kmem_cache_create("ip_fib_alias", 1934 sizeof(struct fib_alias), 1935 0, SLAB_PANIC, NULL); 1936 1937 trie_leaf_kmem = kmem_cache_create("ip_fib_trie", 1938 LEAF_SIZE, 1939 0, SLAB_PANIC, NULL); 1940 } 1941 1942 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias) 1943 { 1944 struct fib_table *tb; 1945 struct trie *t; 1946 size_t sz = sizeof(*tb); 1947 1948 if (!alias) 1949 sz += sizeof(struct trie); 1950 1951 tb = kzalloc(sz, GFP_KERNEL); 1952 if (!tb) 1953 return NULL; 1954 1955 tb->tb_id = id; 1956 tb->tb_num_default = 0; 1957 tb->tb_data = (alias ? alias->__data : tb->__data); 1958 1959 if (alias) 1960 return tb; 1961 1962 t = (struct trie *) tb->tb_data; 1963 t->kv[0].pos = KEYLENGTH; 1964 t->kv[0].slen = KEYLENGTH; 1965 #ifdef CONFIG_IP_FIB_TRIE_STATS 1966 t->stats = alloc_percpu(struct trie_use_stats); 1967 if (!t->stats) { 1968 kfree(tb); 1969 tb = NULL; 1970 } 1971 #endif 1972 1973 return tb; 1974 } 1975 1976 #ifdef CONFIG_PROC_FS 1977 /* Depth first Trie walk iterator */ 1978 struct fib_trie_iter { 1979 struct seq_net_private p; 1980 struct fib_table *tb; 1981 struct key_vector *tnode; 1982 unsigned int index; 1983 unsigned int depth; 1984 }; 1985 1986 static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter) 1987 { 1988 unsigned long cindex = iter->index; 1989 struct key_vector *pn = iter->tnode; 1990 t_key pkey; 1991 1992 pr_debug("get_next iter={node=%p index=%d depth=%d}\n", 1993 iter->tnode, iter->index, iter->depth); 1994 1995 while (!IS_TRIE(pn)) { 1996 while (cindex < child_length(pn)) { 1997 struct key_vector *n = get_child_rcu(pn, cindex++); 1998 1999 if (!n) 2000 continue; 2001 2002 if (IS_LEAF(n)) { 2003 iter->tnode = pn; 2004 iter->index = cindex; 2005 } else { 2006 /* push down one level */ 2007 iter->tnode = n; 2008 iter->index = 0; 2009 ++iter->depth; 2010 } 2011 2012 return n; 2013 } 2014 2015 /* Current node exhausted, pop back up */ 2016 pkey = pn->key; 2017 pn = node_parent_rcu(pn); 2018 cindex = get_index(pkey, pn) + 1; 2019 --iter->depth; 2020 } 2021 2022 /* record root node so further searches know we are done */ 2023 iter->tnode = pn; 2024 iter->index = 0; 2025 2026 return NULL; 2027 } 2028 2029 static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter, 2030 struct trie *t) 2031 { 2032 struct key_vector *n, *pn; 2033 2034 if (!t) 2035 return NULL; 2036 2037 pn = t->kv; 2038 n = rcu_dereference(pn->tnode[0]); 2039 if (!n) 2040 return NULL; 2041 2042 if (IS_TNODE(n)) { 2043 iter->tnode = n; 2044 iter->index = 0; 2045 iter->depth = 1; 2046 } else { 2047 iter->tnode = pn; 2048 iter->index = 0; 2049 iter->depth = 0; 2050 } 2051 2052 return n; 2053 } 2054 2055 static void trie_collect_stats(struct trie *t, struct trie_stat *s) 2056 { 2057 struct key_vector *n; 2058 struct fib_trie_iter iter; 2059 2060 memset(s, 0, sizeof(*s)); 2061 2062 rcu_read_lock(); 2063 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) { 2064 if (IS_LEAF(n)) { 2065 struct fib_alias *fa; 2066 2067 s->leaves++; 2068 s->totdepth += iter.depth; 2069 if (iter.depth > s->maxdepth) 2070 s->maxdepth = iter.depth; 2071 2072 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) 2073 ++s->prefixes; 2074 } else { 2075 s->tnodes++; 2076 if (n->bits < MAX_STAT_DEPTH) 2077 s->nodesizes[n->bits]++; 2078 s->nullpointers += tn_info(n)->empty_children; 2079 } 2080 } 2081 rcu_read_unlock(); 2082 } 2083 2084 /* 2085 * This outputs /proc/net/fib_triestats 2086 */ 2087 static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat) 2088 { 2089 unsigned int i, max, pointers, bytes, avdepth; 2090 2091 if (stat->leaves) 2092 avdepth = stat->totdepth*100 / stat->leaves; 2093 else 2094 avdepth = 0; 2095 2096 seq_printf(seq, "\tAver depth: %u.%02d\n", 2097 avdepth / 100, avdepth % 100); 2098 seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth); 2099 2100 seq_printf(seq, "\tLeaves: %u\n", stat->leaves); 2101 bytes = LEAF_SIZE * stat->leaves; 2102 2103 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes); 2104 bytes += sizeof(struct fib_alias) * stat->prefixes; 2105 2106 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes); 2107 bytes += TNODE_SIZE(0) * stat->tnodes; 2108 2109 max = MAX_STAT_DEPTH; 2110 while (max > 0 && stat->nodesizes[max-1] == 0) 2111 max--; 2112 2113 pointers = 0; 2114 for (i = 1; i < max; i++) 2115 if (stat->nodesizes[i] != 0) { 2116 seq_printf(seq, " %u: %u", i, stat->nodesizes[i]); 2117 pointers += (1<<i) * stat->nodesizes[i]; 2118 } 2119 seq_putc(seq, '\n'); 2120 seq_printf(seq, "\tPointers: %u\n", pointers); 2121 2122 bytes += sizeof(struct key_vector *) * pointers; 2123 seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers); 2124 seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024); 2125 } 2126 2127 #ifdef CONFIG_IP_FIB_TRIE_STATS 2128 static void trie_show_usage(struct seq_file *seq, 2129 const struct trie_use_stats __percpu *stats) 2130 { 2131 struct trie_use_stats s = { 0 }; 2132 int cpu; 2133 2134 /* loop through all of the CPUs and gather up the stats */ 2135 for_each_possible_cpu(cpu) { 2136 const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu); 2137 2138 s.gets += pcpu->gets; 2139 s.backtrack += pcpu->backtrack; 2140 s.semantic_match_passed += pcpu->semantic_match_passed; 2141 s.semantic_match_miss += pcpu->semantic_match_miss; 2142 s.null_node_hit += pcpu->null_node_hit; 2143 s.resize_node_skipped += pcpu->resize_node_skipped; 2144 } 2145 2146 seq_printf(seq, "\nCounters:\n---------\n"); 2147 seq_printf(seq, "gets = %u\n", s.gets); 2148 seq_printf(seq, "backtracks = %u\n", s.backtrack); 2149 seq_printf(seq, "semantic match passed = %u\n", 2150 s.semantic_match_passed); 2151 seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss); 2152 seq_printf(seq, "null node hit= %u\n", s.null_node_hit); 2153 seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped); 2154 } 2155 #endif /* CONFIG_IP_FIB_TRIE_STATS */ 2156 2157 static void fib_table_print(struct seq_file *seq, struct fib_table *tb) 2158 { 2159 if (tb->tb_id == RT_TABLE_LOCAL) 2160 seq_puts(seq, "Local:\n"); 2161 else if (tb->tb_id == RT_TABLE_MAIN) 2162 seq_puts(seq, "Main:\n"); 2163 else 2164 seq_printf(seq, "Id %d:\n", tb->tb_id); 2165 } 2166 2167 2168 static int fib_triestat_seq_show(struct seq_file *seq, void *v) 2169 { 2170 struct net *net = (struct net *)seq->private; 2171 unsigned int h; 2172 2173 seq_printf(seq, 2174 "Basic info: size of leaf:" 2175 " %Zd bytes, size of tnode: %Zd bytes.\n", 2176 LEAF_SIZE, TNODE_SIZE(0)); 2177 2178 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2179 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2180 struct fib_table *tb; 2181 2182 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2183 struct trie *t = (struct trie *) tb->tb_data; 2184 struct trie_stat stat; 2185 2186 if (!t) 2187 continue; 2188 2189 fib_table_print(seq, tb); 2190 2191 trie_collect_stats(t, &stat); 2192 trie_show_stats(seq, &stat); 2193 #ifdef CONFIG_IP_FIB_TRIE_STATS 2194 trie_show_usage(seq, t->stats); 2195 #endif 2196 } 2197 } 2198 2199 return 0; 2200 } 2201 2202 static int fib_triestat_seq_open(struct inode *inode, struct file *file) 2203 { 2204 return single_open_net(inode, file, fib_triestat_seq_show); 2205 } 2206 2207 static const struct file_operations fib_triestat_fops = { 2208 .owner = THIS_MODULE, 2209 .open = fib_triestat_seq_open, 2210 .read = seq_read, 2211 .llseek = seq_lseek, 2212 .release = single_release_net, 2213 }; 2214 2215 static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos) 2216 { 2217 struct fib_trie_iter *iter = seq->private; 2218 struct net *net = seq_file_net(seq); 2219 loff_t idx = 0; 2220 unsigned int h; 2221 2222 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2223 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2224 struct fib_table *tb; 2225 2226 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2227 struct key_vector *n; 2228 2229 for (n = fib_trie_get_first(iter, 2230 (struct trie *) tb->tb_data); 2231 n; n = fib_trie_get_next(iter)) 2232 if (pos == idx++) { 2233 iter->tb = tb; 2234 return n; 2235 } 2236 } 2237 } 2238 2239 return NULL; 2240 } 2241 2242 static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos) 2243 __acquires(RCU) 2244 { 2245 rcu_read_lock(); 2246 return fib_trie_get_idx(seq, *pos); 2247 } 2248 2249 static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2250 { 2251 struct fib_trie_iter *iter = seq->private; 2252 struct net *net = seq_file_net(seq); 2253 struct fib_table *tb = iter->tb; 2254 struct hlist_node *tb_node; 2255 unsigned int h; 2256 struct key_vector *n; 2257 2258 ++*pos; 2259 /* next node in same table */ 2260 n = fib_trie_get_next(iter); 2261 if (n) 2262 return n; 2263 2264 /* walk rest of this hash chain */ 2265 h = tb->tb_id & (FIB_TABLE_HASHSZ - 1); 2266 while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) { 2267 tb = hlist_entry(tb_node, struct fib_table, tb_hlist); 2268 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data); 2269 if (n) 2270 goto found; 2271 } 2272 2273 /* new hash chain */ 2274 while (++h < FIB_TABLE_HASHSZ) { 2275 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2276 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2277 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data); 2278 if (n) 2279 goto found; 2280 } 2281 } 2282 return NULL; 2283 2284 found: 2285 iter->tb = tb; 2286 return n; 2287 } 2288 2289 static void fib_trie_seq_stop(struct seq_file *seq, void *v) 2290 __releases(RCU) 2291 { 2292 rcu_read_unlock(); 2293 } 2294 2295 static void seq_indent(struct seq_file *seq, int n) 2296 { 2297 while (n-- > 0) 2298 seq_puts(seq, " "); 2299 } 2300 2301 static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s) 2302 { 2303 switch (s) { 2304 case RT_SCOPE_UNIVERSE: return "universe"; 2305 case RT_SCOPE_SITE: return "site"; 2306 case RT_SCOPE_LINK: return "link"; 2307 case RT_SCOPE_HOST: return "host"; 2308 case RT_SCOPE_NOWHERE: return "nowhere"; 2309 default: 2310 snprintf(buf, len, "scope=%d", s); 2311 return buf; 2312 } 2313 } 2314 2315 static const char *const rtn_type_names[__RTN_MAX] = { 2316 [RTN_UNSPEC] = "UNSPEC", 2317 [RTN_UNICAST] = "UNICAST", 2318 [RTN_LOCAL] = "LOCAL", 2319 [RTN_BROADCAST] = "BROADCAST", 2320 [RTN_ANYCAST] = "ANYCAST", 2321 [RTN_MULTICAST] = "MULTICAST", 2322 [RTN_BLACKHOLE] = "BLACKHOLE", 2323 [RTN_UNREACHABLE] = "UNREACHABLE", 2324 [RTN_PROHIBIT] = "PROHIBIT", 2325 [RTN_THROW] = "THROW", 2326 [RTN_NAT] = "NAT", 2327 [RTN_XRESOLVE] = "XRESOLVE", 2328 }; 2329 2330 static inline const char *rtn_type(char *buf, size_t len, unsigned int t) 2331 { 2332 if (t < __RTN_MAX && rtn_type_names[t]) 2333 return rtn_type_names[t]; 2334 snprintf(buf, len, "type %u", t); 2335 return buf; 2336 } 2337 2338 /* Pretty print the trie */ 2339 static int fib_trie_seq_show(struct seq_file *seq, void *v) 2340 { 2341 const struct fib_trie_iter *iter = seq->private; 2342 struct key_vector *n = v; 2343 2344 if (IS_TRIE(node_parent_rcu(n))) 2345 fib_table_print(seq, iter->tb); 2346 2347 if (IS_TNODE(n)) { 2348 __be32 prf = htonl(n->key); 2349 2350 seq_indent(seq, iter->depth-1); 2351 seq_printf(seq, " +-- %pI4/%zu %u %u %u\n", 2352 &prf, KEYLENGTH - n->pos - n->bits, n->bits, 2353 tn_info(n)->full_children, 2354 tn_info(n)->empty_children); 2355 } else { 2356 __be32 val = htonl(n->key); 2357 struct fib_alias *fa; 2358 2359 seq_indent(seq, iter->depth); 2360 seq_printf(seq, " |-- %pI4\n", &val); 2361 2362 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) { 2363 char buf1[32], buf2[32]; 2364 2365 seq_indent(seq, iter->depth + 1); 2366 seq_printf(seq, " /%zu %s %s", 2367 KEYLENGTH - fa->fa_slen, 2368 rtn_scope(buf1, sizeof(buf1), 2369 fa->fa_info->fib_scope), 2370 rtn_type(buf2, sizeof(buf2), 2371 fa->fa_type)); 2372 if (fa->fa_tos) 2373 seq_printf(seq, " tos=%d", fa->fa_tos); 2374 seq_putc(seq, '\n'); 2375 } 2376 } 2377 2378 return 0; 2379 } 2380 2381 static const struct seq_operations fib_trie_seq_ops = { 2382 .start = fib_trie_seq_start, 2383 .next = fib_trie_seq_next, 2384 .stop = fib_trie_seq_stop, 2385 .show = fib_trie_seq_show, 2386 }; 2387 2388 static int fib_trie_seq_open(struct inode *inode, struct file *file) 2389 { 2390 return seq_open_net(inode, file, &fib_trie_seq_ops, 2391 sizeof(struct fib_trie_iter)); 2392 } 2393 2394 static const struct file_operations fib_trie_fops = { 2395 .owner = THIS_MODULE, 2396 .open = fib_trie_seq_open, 2397 .read = seq_read, 2398 .llseek = seq_lseek, 2399 .release = seq_release_net, 2400 }; 2401 2402 struct fib_route_iter { 2403 struct seq_net_private p; 2404 struct fib_table *main_tb; 2405 struct key_vector *tnode; 2406 loff_t pos; 2407 t_key key; 2408 }; 2409 2410 static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter, 2411 loff_t pos) 2412 { 2413 struct key_vector *l, **tp = &iter->tnode; 2414 t_key key; 2415 2416 /* use cache location of next-to-find key */ 2417 if (iter->pos > 0 && pos >= iter->pos) { 2418 pos -= iter->pos; 2419 key = iter->key; 2420 } else { 2421 iter->pos = 0; 2422 key = 0; 2423 } 2424 2425 while ((l = leaf_walk_rcu(tp, key)) != NULL) { 2426 key = l->key + 1; 2427 iter->pos++; 2428 2429 if (--pos <= 0) 2430 break; 2431 2432 l = NULL; 2433 2434 /* handle unlikely case of a key wrap */ 2435 if (!key) 2436 break; 2437 } 2438 2439 if (l) 2440 iter->key = key; /* remember it */ 2441 else 2442 iter->pos = 0; /* forget it */ 2443 2444 return l; 2445 } 2446 2447 static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos) 2448 __acquires(RCU) 2449 { 2450 struct fib_route_iter *iter = seq->private; 2451 struct fib_table *tb; 2452 struct trie *t; 2453 2454 rcu_read_lock(); 2455 2456 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN); 2457 if (!tb) 2458 return NULL; 2459 2460 iter->main_tb = tb; 2461 t = (struct trie *)tb->tb_data; 2462 iter->tnode = t->kv; 2463 2464 if (*pos != 0) 2465 return fib_route_get_idx(iter, *pos); 2466 2467 iter->pos = 0; 2468 iter->key = 0; 2469 2470 return SEQ_START_TOKEN; 2471 } 2472 2473 static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2474 { 2475 struct fib_route_iter *iter = seq->private; 2476 struct key_vector *l = NULL; 2477 t_key key = iter->key; 2478 2479 ++*pos; 2480 2481 /* only allow key of 0 for start of sequence */ 2482 if ((v == SEQ_START_TOKEN) || key) 2483 l = leaf_walk_rcu(&iter->tnode, key); 2484 2485 if (l) { 2486 iter->key = l->key + 1; 2487 iter->pos++; 2488 } else { 2489 iter->pos = 0; 2490 } 2491 2492 return l; 2493 } 2494 2495 static void fib_route_seq_stop(struct seq_file *seq, void *v) 2496 __releases(RCU) 2497 { 2498 rcu_read_unlock(); 2499 } 2500 2501 static unsigned int fib_flag_trans(int type, __be32 mask, const struct fib_info *fi) 2502 { 2503 unsigned int flags = 0; 2504 2505 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT) 2506 flags = RTF_REJECT; 2507 if (fi && fi->fib_nh->nh_gw) 2508 flags |= RTF_GATEWAY; 2509 if (mask == htonl(0xFFFFFFFF)) 2510 flags |= RTF_HOST; 2511 flags |= RTF_UP; 2512 return flags; 2513 } 2514 2515 /* 2516 * This outputs /proc/net/route. 2517 * The format of the file is not supposed to be changed 2518 * and needs to be same as fib_hash output to avoid breaking 2519 * legacy utilities 2520 */ 2521 static int fib_route_seq_show(struct seq_file *seq, void *v) 2522 { 2523 struct fib_route_iter *iter = seq->private; 2524 struct fib_table *tb = iter->main_tb; 2525 struct fib_alias *fa; 2526 struct key_vector *l = v; 2527 __be32 prefix; 2528 2529 if (v == SEQ_START_TOKEN) { 2530 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway " 2531 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU" 2532 "\tWindow\tIRTT"); 2533 return 0; 2534 } 2535 2536 prefix = htonl(l->key); 2537 2538 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 2539 const struct fib_info *fi = fa->fa_info; 2540 __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen); 2541 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi); 2542 2543 if ((fa->fa_type == RTN_BROADCAST) || 2544 (fa->fa_type == RTN_MULTICAST)) 2545 continue; 2546 2547 if (fa->tb_id != tb->tb_id) 2548 continue; 2549 2550 seq_setwidth(seq, 127); 2551 2552 if (fi) 2553 seq_printf(seq, 2554 "%s\t%08X\t%08X\t%04X\t%d\t%u\t" 2555 "%d\t%08X\t%d\t%u\t%u", 2556 fi->fib_dev ? fi->fib_dev->name : "*", 2557 prefix, 2558 fi->fib_nh->nh_gw, flags, 0, 0, 2559 fi->fib_priority, 2560 mask, 2561 (fi->fib_advmss ? 2562 fi->fib_advmss + 40 : 0), 2563 fi->fib_window, 2564 fi->fib_rtt >> 3); 2565 else 2566 seq_printf(seq, 2567 "*\t%08X\t%08X\t%04X\t%d\t%u\t" 2568 "%d\t%08X\t%d\t%u\t%u", 2569 prefix, 0, flags, 0, 0, 0, 2570 mask, 0, 0, 0); 2571 2572 seq_pad(seq, '\n'); 2573 } 2574 2575 return 0; 2576 } 2577 2578 static const struct seq_operations fib_route_seq_ops = { 2579 .start = fib_route_seq_start, 2580 .next = fib_route_seq_next, 2581 .stop = fib_route_seq_stop, 2582 .show = fib_route_seq_show, 2583 }; 2584 2585 static int fib_route_seq_open(struct inode *inode, struct file *file) 2586 { 2587 return seq_open_net(inode, file, &fib_route_seq_ops, 2588 sizeof(struct fib_route_iter)); 2589 } 2590 2591 static const struct file_operations fib_route_fops = { 2592 .owner = THIS_MODULE, 2593 .open = fib_route_seq_open, 2594 .read = seq_read, 2595 .llseek = seq_lseek, 2596 .release = seq_release_net, 2597 }; 2598 2599 int __net_init fib_proc_init(struct net *net) 2600 { 2601 if (!proc_create("fib_trie", S_IRUGO, net->proc_net, &fib_trie_fops)) 2602 goto out1; 2603 2604 if (!proc_create("fib_triestat", S_IRUGO, net->proc_net, 2605 &fib_triestat_fops)) 2606 goto out2; 2607 2608 if (!proc_create("route", S_IRUGO, net->proc_net, &fib_route_fops)) 2609 goto out3; 2610 2611 return 0; 2612 2613 out3: 2614 remove_proc_entry("fib_triestat", net->proc_net); 2615 out2: 2616 remove_proc_entry("fib_trie", net->proc_net); 2617 out1: 2618 return -ENOMEM; 2619 } 2620 2621 void __net_exit fib_proc_exit(struct net *net) 2622 { 2623 remove_proc_entry("fib_trie", net->proc_net); 2624 remove_proc_entry("fib_triestat", net->proc_net); 2625 remove_proc_entry("route", net->proc_net); 2626 } 2627 2628 #endif /* CONFIG_PROC_FS */ 2629