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 <net/net_namespace.h> 76#include <net/ip.h> 77#include <net/protocol.h> 78#include <net/route.h> 79#include <net/tcp.h> 80#include <net/sock.h> 81#include <net/ip_fib.h> 82#include <net/switchdev.h> 83#include "fib_lookup.h" 84 85#define MAX_STAT_DEPTH 32 86 87#define KEYLENGTH (8*sizeof(t_key)) 88#define KEY_MAX ((t_key)~0) 89 90typedef unsigned int t_key; 91 92#define IS_TRIE(n) ((n)->pos >= KEYLENGTH) 93#define IS_TNODE(n) ((n)->bits) 94#define IS_LEAF(n) (!(n)->bits) 95 96struct key_vector { 97 t_key key; 98 unsigned char pos; /* 2log(KEYLENGTH) bits needed */ 99 unsigned char bits; /* 2log(KEYLENGTH) bits needed */ 100 unsigned char slen; 101 union { 102 /* This list pointer if valid if (pos | bits) == 0 (LEAF) */ 103 struct hlist_head leaf; 104 /* This array is valid if (pos | bits) > 0 (TNODE) */ 105 struct key_vector __rcu *tnode[0]; 106 }; 107}; 108 109struct tnode { 110 struct rcu_head rcu; 111 t_key empty_children; /* KEYLENGTH bits needed */ 112 t_key full_children; /* KEYLENGTH bits needed */ 113 struct key_vector __rcu *parent; 114 struct key_vector kv[1]; 115#define tn_bits kv[0].bits 116}; 117 118#define TNODE_SIZE(n) offsetof(struct tnode, kv[0].tnode[n]) 119#define LEAF_SIZE TNODE_SIZE(1) 120 121#ifdef CONFIG_IP_FIB_TRIE_STATS 122struct trie_use_stats { 123 unsigned int gets; 124 unsigned int backtrack; 125 unsigned int semantic_match_passed; 126 unsigned int semantic_match_miss; 127 unsigned int null_node_hit; 128 unsigned int resize_node_skipped; 129}; 130#endif 131 132struct trie_stat { 133 unsigned int totdepth; 134 unsigned int maxdepth; 135 unsigned int tnodes; 136 unsigned int leaves; 137 unsigned int nullpointers; 138 unsigned int prefixes; 139 unsigned int nodesizes[MAX_STAT_DEPTH]; 140}; 141 142struct trie { 143 struct key_vector kv[1]; 144#ifdef CONFIG_IP_FIB_TRIE_STATS 145 struct trie_use_stats __percpu *stats; 146#endif 147}; 148 149static struct key_vector *resize(struct trie *t, struct key_vector *tn); 150static size_t tnode_free_size; 151 152/* 153 * synchronize_rcu after call_rcu for that many pages; it should be especially 154 * useful before resizing the root node with PREEMPT_NONE configs; the value was 155 * obtained experimentally, aiming to avoid visible slowdown. 156 */ 157static const int sync_pages = 128; 158 159static struct kmem_cache *fn_alias_kmem __read_mostly; 160static struct kmem_cache *trie_leaf_kmem __read_mostly; 161 162static inline struct tnode *tn_info(struct key_vector *kv) 163{ 164 return container_of(kv, struct tnode, kv[0]); 165} 166 167/* caller must hold RTNL */ 168#define node_parent(tn) rtnl_dereference(tn_info(tn)->parent) 169#define get_child(tn, i) rtnl_dereference((tn)->tnode[i]) 170 171/* caller must hold RCU read lock or RTNL */ 172#define node_parent_rcu(tn) rcu_dereference_rtnl(tn_info(tn)->parent) 173#define get_child_rcu(tn, i) rcu_dereference_rtnl((tn)->tnode[i]) 174 175/* wrapper for rcu_assign_pointer */ 176static inline void node_set_parent(struct key_vector *n, struct key_vector *tp) 177{ 178 if (n) 179 rcu_assign_pointer(tn_info(n)->parent, tp); 180} 181 182#define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER(tn_info(n)->parent, p) 183 184/* This provides us with the number of children in this node, in the case of a 185 * leaf this will return 0 meaning none of the children are accessible. 186 */ 187static inline unsigned long child_length(const struct key_vector *tn) 188{ 189 return (1ul << tn->bits) & ~(1ul); 190} 191 192#define get_cindex(key, kv) (((key) ^ (kv)->key) >> (kv)->pos) 193 194static inline unsigned long get_index(t_key key, struct key_vector *kv) 195{ 196 unsigned long index = key ^ kv->key; 197 198 if ((BITS_PER_LONG <= KEYLENGTH) && (KEYLENGTH == kv->pos)) 199 return 0; 200 201 return index >> kv->pos; 202} 203 204/* To understand this stuff, an understanding of keys and all their bits is 205 * necessary. Every node in the trie has a key associated with it, but not 206 * all of the bits in that key are significant. 207 * 208 * Consider a node 'n' and its parent 'tp'. 209 * 210 * If n is a leaf, every bit in its key is significant. Its presence is 211 * necessitated by path compression, since during a tree traversal (when 212 * searching for a leaf - unless we are doing an insertion) we will completely 213 * ignore all skipped bits we encounter. Thus we need to verify, at the end of 214 * a potentially successful search, that we have indeed been walking the 215 * correct key path. 216 * 217 * Note that we can never "miss" the correct key in the tree if present by 218 * following the wrong path. Path compression ensures that segments of the key 219 * that are the same for all keys with a given prefix are skipped, but the 220 * skipped part *is* identical for each node in the subtrie below the skipped 221 * bit! trie_insert() in this implementation takes care of that. 222 * 223 * if n is an internal node - a 'tnode' here, the various parts of its key 224 * have many different meanings. 225 * 226 * Example: 227 * _________________________________________________________________ 228 * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C | 229 * ----------------------------------------------------------------- 230 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 231 * 232 * _________________________________________________________________ 233 * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u | 234 * ----------------------------------------------------------------- 235 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 236 * 237 * tp->pos = 22 238 * tp->bits = 3 239 * n->pos = 13 240 * n->bits = 4 241 * 242 * First, let's just ignore the bits that come before the parent tp, that is 243 * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this 244 * point we do not use them for anything. 245 * 246 * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the 247 * index into the parent's child array. That is, they will be used to find 248 * 'n' among tp's children. 249 * 250 * The bits from (n->pos + n->bits) to (tn->pos - 1) - "S" - are skipped bits 251 * for the node n. 252 * 253 * All the bits we have seen so far are significant to the node n. The rest 254 * of the bits are really not needed or indeed known in n->key. 255 * 256 * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into 257 * n's child array, and will of course be different for each child. 258 * 259 * The rest of the bits, from 0 to (n->pos + n->bits), are completely unknown 260 * at this point. 261 */ 262 263static const int halve_threshold = 25; 264static const int inflate_threshold = 50; 265static const int halve_threshold_root = 15; 266static const int inflate_threshold_root = 30; 267 268static void __alias_free_mem(struct rcu_head *head) 269{ 270 struct fib_alias *fa = container_of(head, struct fib_alias, rcu); 271 kmem_cache_free(fn_alias_kmem, fa); 272} 273 274static inline void alias_free_mem_rcu(struct fib_alias *fa) 275{ 276 call_rcu(&fa->rcu, __alias_free_mem); 277} 278 279#define TNODE_KMALLOC_MAX \ 280 ilog2((PAGE_SIZE - TNODE_SIZE(0)) / sizeof(struct key_vector *)) 281#define TNODE_VMALLOC_MAX \ 282 ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *)) 283 284static void __node_free_rcu(struct rcu_head *head) 285{ 286 struct tnode *n = container_of(head, struct tnode, rcu); 287 288 if (!n->tn_bits) 289 kmem_cache_free(trie_leaf_kmem, n); 290 else if (n->tn_bits <= TNODE_KMALLOC_MAX) 291 kfree(n); 292 else 293 vfree(n); 294} 295 296#define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu) 297 298static struct tnode *tnode_alloc(int bits) 299{ 300 size_t size; 301 302 /* verify bits is within bounds */ 303 if (bits > TNODE_VMALLOC_MAX) 304 return NULL; 305 306 /* determine size and verify it is non-zero and didn't overflow */ 307 size = TNODE_SIZE(1ul << bits); 308 309 if (size <= PAGE_SIZE) 310 return kzalloc(size, GFP_KERNEL); 311 else 312 return vzalloc(size); 313} 314 315static inline void empty_child_inc(struct key_vector *n) 316{ 317 ++tn_info(n)->empty_children ? : ++tn_info(n)->full_children; 318} 319 320static inline void empty_child_dec(struct key_vector *n) 321{ 322 tn_info(n)->empty_children-- ? : tn_info(n)->full_children--; 323} 324 325static struct key_vector *leaf_new(t_key key, struct fib_alias *fa) 326{ 327 struct tnode *kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL); 328 struct key_vector *l = kv->kv; 329 330 if (!kv) 331 return NULL; 332 333 /* initialize key vector */ 334 l->key = key; 335 l->pos = 0; 336 l->bits = 0; 337 l->slen = fa->fa_slen; 338 339 /* link leaf to fib alias */ 340 INIT_HLIST_HEAD(&l->leaf); 341 hlist_add_head(&fa->fa_list, &l->leaf); 342 343 return l; 344} 345 346static struct key_vector *tnode_new(t_key key, int pos, int bits) 347{ 348 struct tnode *tnode = tnode_alloc(bits); 349 unsigned int shift = pos + bits; 350 struct key_vector *tn = tnode->kv; 351 352 /* verify bits and pos their msb bits clear and values are valid */ 353 BUG_ON(!bits || (shift > KEYLENGTH)); 354 355 pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0), 356 sizeof(struct key_vector *) << bits); 357 358 if (!tnode) 359 return NULL; 360 361 if (bits == KEYLENGTH) 362 tnode->full_children = 1; 363 else 364 tnode->empty_children = 1ul << bits; 365 366 tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0; 367 tn->pos = pos; 368 tn->bits = bits; 369 tn->slen = pos; 370 371 return tn; 372} 373 374/* Check whether a tnode 'n' is "full", i.e. it is an internal node 375 * and no bits are skipped. See discussion in dyntree paper p. 6 376 */ 377static inline int tnode_full(struct key_vector *tn, struct key_vector *n) 378{ 379 return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n); 380} 381 382/* Add a child at position i overwriting the old value. 383 * Update the value of full_children and empty_children. 384 */ 385static void put_child(struct key_vector *tn, unsigned long i, 386 struct key_vector *n) 387{ 388 struct key_vector *chi = get_child(tn, i); 389 int isfull, wasfull; 390 391 BUG_ON(i >= child_length(tn)); 392 393 /* update emptyChildren, overflow into fullChildren */ 394 if (!n && chi) 395 empty_child_inc(tn); 396 if (n && !chi) 397 empty_child_dec(tn); 398 399 /* update fullChildren */ 400 wasfull = tnode_full(tn, chi); 401 isfull = tnode_full(tn, n); 402 403 if (wasfull && !isfull) 404 tn_info(tn)->full_children--; 405 else if (!wasfull && isfull) 406 tn_info(tn)->full_children++; 407 408 if (n && (tn->slen < n->slen)) 409 tn->slen = n->slen; 410 411 rcu_assign_pointer(tn->tnode[i], n); 412} 413 414static void update_children(struct key_vector *tn) 415{ 416 unsigned long i; 417 418 /* update all of the child parent pointers */ 419 for (i = child_length(tn); i;) { 420 struct key_vector *inode = get_child(tn, --i); 421 422 if (!inode) 423 continue; 424 425 /* Either update the children of a tnode that 426 * already belongs to us or update the child 427 * to point to ourselves. 428 */ 429 if (node_parent(inode) == tn) 430 update_children(inode); 431 else 432 node_set_parent(inode, tn); 433 } 434} 435 436static inline void put_child_root(struct key_vector *tp, t_key key, 437 struct key_vector *n) 438{ 439 if (IS_TRIE(tp)) 440 rcu_assign_pointer(tp->tnode[0], n); 441 else 442 put_child(tp, get_index(key, tp), n); 443} 444 445static inline void tnode_free_init(struct key_vector *tn) 446{ 447 tn_info(tn)->rcu.next = NULL; 448} 449 450static inline void tnode_free_append(struct key_vector *tn, 451 struct key_vector *n) 452{ 453 tn_info(n)->rcu.next = tn_info(tn)->rcu.next; 454 tn_info(tn)->rcu.next = &tn_info(n)->rcu; 455} 456 457static void tnode_free(struct key_vector *tn) 458{ 459 struct callback_head *head = &tn_info(tn)->rcu; 460 461 while (head) { 462 head = head->next; 463 tnode_free_size += TNODE_SIZE(1ul << tn->bits); 464 node_free(tn); 465 466 tn = container_of(head, struct tnode, rcu)->kv; 467 } 468 469 if (tnode_free_size >= PAGE_SIZE * sync_pages) { 470 tnode_free_size = 0; 471 synchronize_rcu(); 472 } 473} 474 475static struct key_vector *replace(struct trie *t, 476 struct key_vector *oldtnode, 477 struct key_vector *tn) 478{ 479 struct key_vector *tp = node_parent(oldtnode); 480 unsigned long i; 481 482 /* setup the parent pointer out of and back into this node */ 483 NODE_INIT_PARENT(tn, tp); 484 put_child_root(tp, tn->key, tn); 485 486 /* update all of the child parent pointers */ 487 update_children(tn); 488 489 /* all pointers should be clean so we are done */ 490 tnode_free(oldtnode); 491 492 /* resize children now that oldtnode is freed */ 493 for (i = child_length(tn); i;) { 494 struct key_vector *inode = get_child(tn, --i); 495 496 /* resize child node */ 497 if (tnode_full(tn, inode)) 498 tn = resize(t, inode); 499 } 500 501 return tp; 502} 503 504static struct key_vector *inflate(struct trie *t, 505 struct key_vector *oldtnode) 506{ 507 struct key_vector *tn; 508 unsigned long i; 509 t_key m; 510 511 pr_debug("In inflate\n"); 512 513 tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1); 514 if (!tn) 515 goto notnode; 516 517 /* prepare oldtnode to be freed */ 518 tnode_free_init(oldtnode); 519 520 /* Assemble all of the pointers in our cluster, in this case that 521 * represents all of the pointers out of our allocated nodes that 522 * point to existing tnodes and the links between our allocated 523 * nodes. 524 */ 525 for (i = child_length(oldtnode), m = 1u << tn->pos; i;) { 526 struct key_vector *inode = get_child(oldtnode, --i); 527 struct key_vector *node0, *node1; 528 unsigned long j, k; 529 530 /* An empty child */ 531 if (!inode) 532 continue; 533 534 /* A leaf or an internal node with skipped bits */ 535 if (!tnode_full(oldtnode, inode)) { 536 put_child(tn, get_index(inode->key, tn), inode); 537 continue; 538 } 539 540 /* drop the node in the old tnode free list */ 541 tnode_free_append(oldtnode, inode); 542 543 /* An internal node with two children */ 544 if (inode->bits == 1) { 545 put_child(tn, 2 * i + 1, get_child(inode, 1)); 546 put_child(tn, 2 * i, get_child(inode, 0)); 547 continue; 548 } 549 550 /* We will replace this node 'inode' with two new 551 * ones, 'node0' and 'node1', each with half of the 552 * original children. The two new nodes will have 553 * a position one bit further down the key and this 554 * means that the "significant" part of their keys 555 * (see the discussion near the top of this file) 556 * will differ by one bit, which will be "0" in 557 * node0's key and "1" in node1's key. Since we are 558 * moving the key position by one step, the bit that 559 * we are moving away from - the bit at position 560 * (tn->pos) - is the one that will differ between 561 * node0 and node1. So... we synthesize that bit in the 562 * two new keys. 563 */ 564 node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1); 565 if (!node1) 566 goto nomem; 567 node0 = tnode_new(inode->key, inode->pos, inode->bits - 1); 568 569 tnode_free_append(tn, node1); 570 if (!node0) 571 goto nomem; 572 tnode_free_append(tn, node0); 573 574 /* populate child pointers in new nodes */ 575 for (k = child_length(inode), j = k / 2; j;) { 576 put_child(node1, --j, get_child(inode, --k)); 577 put_child(node0, j, get_child(inode, j)); 578 put_child(node1, --j, get_child(inode, --k)); 579 put_child(node0, j, get_child(inode, j)); 580 } 581 582 /* link new nodes to parent */ 583 NODE_INIT_PARENT(node1, tn); 584 NODE_INIT_PARENT(node0, tn); 585 586 /* link parent to nodes */ 587 put_child(tn, 2 * i + 1, node1); 588 put_child(tn, 2 * i, node0); 589 } 590 591 /* setup the parent pointers into and out of this node */ 592 return replace(t, oldtnode, tn); 593nomem: 594 /* all pointers should be clean so we are done */ 595 tnode_free(tn); 596notnode: 597 return NULL; 598} 599 600static struct key_vector *halve(struct trie *t, 601 struct key_vector *oldtnode) 602{ 603 struct key_vector *tn; 604 unsigned long i; 605 606 pr_debug("In halve\n"); 607 608 tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1); 609 if (!tn) 610 goto notnode; 611 612 /* prepare oldtnode to be freed */ 613 tnode_free_init(oldtnode); 614 615 /* Assemble all of the pointers in our cluster, in this case that 616 * represents all of the pointers out of our allocated nodes that 617 * point to existing tnodes and the links between our allocated 618 * nodes. 619 */ 620 for (i = child_length(oldtnode); i;) { 621 struct key_vector *node1 = get_child(oldtnode, --i); 622 struct key_vector *node0 = get_child(oldtnode, --i); 623 struct key_vector *inode; 624 625 /* At least one of the children is empty */ 626 if (!node1 || !node0) { 627 put_child(tn, i / 2, node1 ? : node0); 628 continue; 629 } 630 631 /* Two nonempty children */ 632 inode = tnode_new(node0->key, oldtnode->pos, 1); 633 if (!inode) 634 goto nomem; 635 tnode_free_append(tn, inode); 636 637 /* initialize pointers out of node */ 638 put_child(inode, 1, node1); 639 put_child(inode, 0, node0); 640 NODE_INIT_PARENT(inode, tn); 641 642 /* link parent to node */ 643 put_child(tn, i / 2, inode); 644 } 645 646 /* setup the parent pointers into and out of this node */ 647 return replace(t, oldtnode, tn); 648nomem: 649 /* all pointers should be clean so we are done */ 650 tnode_free(tn); 651notnode: 652 return NULL; 653} 654 655static struct key_vector *collapse(struct trie *t, 656 struct key_vector *oldtnode) 657{ 658 struct key_vector *n, *tp; 659 unsigned long i; 660 661 /* scan the tnode looking for that one child that might still exist */ 662 for (n = NULL, i = child_length(oldtnode); !n && i;) 663 n = get_child(oldtnode, --i); 664 665 /* compress one level */ 666 tp = node_parent(oldtnode); 667 put_child_root(tp, oldtnode->key, n); 668 node_set_parent(n, tp); 669 670 /* drop dead node */ 671 node_free(oldtnode); 672 673 return tp; 674} 675 676static unsigned char update_suffix(struct key_vector *tn) 677{ 678 unsigned char slen = tn->pos; 679 unsigned long stride, i; 680 681 /* search though the list of children looking for nodes that might 682 * have a suffix greater than the one we currently have. This is 683 * why we start with a stride of 2 since a stride of 1 would 684 * represent the nodes with suffix length equal to tn->pos 685 */ 686 for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) { 687 struct key_vector *n = get_child(tn, i); 688 689 if (!n || (n->slen <= slen)) 690 continue; 691 692 /* update stride and slen based on new value */ 693 stride <<= (n->slen - slen); 694 slen = n->slen; 695 i &= ~(stride - 1); 696 697 /* if slen covers all but the last bit we can stop here 698 * there will be nothing longer than that since only node 699 * 0 and 1 << (bits - 1) could have that as their suffix 700 * length. 701 */ 702 if ((slen + 1) >= (tn->pos + tn->bits)) 703 break; 704 } 705 706 tn->slen = slen; 707 708 return slen; 709} 710 711/* From "Implementing a dynamic compressed trie" by Stefan Nilsson of 712 * the Helsinki University of Technology and Matti Tikkanen of Nokia 713 * Telecommunications, page 6: 714 * "A node is doubled if the ratio of non-empty children to all 715 * children in the *doubled* node is at least 'high'." 716 * 717 * 'high' in this instance is the variable 'inflate_threshold'. It 718 * is expressed as a percentage, so we multiply it with 719 * child_length() and instead of multiplying by 2 (since the 720 * child array will be doubled by inflate()) and multiplying 721 * the left-hand side by 100 (to handle the percentage thing) we 722 * multiply the left-hand side by 50. 723 * 724 * The left-hand side may look a bit weird: child_length(tn) 725 * - tn->empty_children is of course the number of non-null children 726 * in the current node. tn->full_children is the number of "full" 727 * children, that is non-null tnodes with a skip value of 0. 728 * All of those will be doubled in the resulting inflated tnode, so 729 * we just count them one extra time here. 730 * 731 * A clearer way to write this would be: 732 * 733 * to_be_doubled = tn->full_children; 734 * not_to_be_doubled = child_length(tn) - tn->empty_children - 735 * tn->full_children; 736 * 737 * new_child_length = child_length(tn) * 2; 738 * 739 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) / 740 * new_child_length; 741 * if (new_fill_factor >= inflate_threshold) 742 * 743 * ...and so on, tho it would mess up the while () loop. 744 * 745 * anyway, 746 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >= 747 * inflate_threshold 748 * 749 * avoid a division: 750 * 100 * (not_to_be_doubled + 2*to_be_doubled) >= 751 * inflate_threshold * new_child_length 752 * 753 * expand not_to_be_doubled and to_be_doubled, and shorten: 754 * 100 * (child_length(tn) - tn->empty_children + 755 * tn->full_children) >= inflate_threshold * new_child_length 756 * 757 * expand new_child_length: 758 * 100 * (child_length(tn) - tn->empty_children + 759 * tn->full_children) >= 760 * inflate_threshold * child_length(tn) * 2 761 * 762 * shorten again: 763 * 50 * (tn->full_children + child_length(tn) - 764 * tn->empty_children) >= inflate_threshold * 765 * child_length(tn) 766 * 767 */ 768static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn) 769{ 770 unsigned long used = child_length(tn); 771 unsigned long threshold = used; 772 773 /* Keep root node larger */ 774 threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold; 775 used -= tn_info(tn)->empty_children; 776 used += tn_info(tn)->full_children; 777 778 /* if bits == KEYLENGTH then pos = 0, and will fail below */ 779 780 return (used > 1) && tn->pos && ((50 * used) >= threshold); 781} 782 783static inline bool should_halve(struct key_vector *tp, struct key_vector *tn) 784{ 785 unsigned long used = child_length(tn); 786 unsigned long threshold = used; 787 788 /* Keep root node larger */ 789 threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold; 790 used -= tn_info(tn)->empty_children; 791 792 /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */ 793 794 return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold); 795} 796 797static inline bool should_collapse(struct key_vector *tn) 798{ 799 unsigned long used = child_length(tn); 800 801 used -= tn_info(tn)->empty_children; 802 803 /* account for bits == KEYLENGTH case */ 804 if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children) 805 used -= KEY_MAX; 806 807 /* One child or none, time to drop us from the trie */ 808 return used < 2; 809} 810 811#define MAX_WORK 10 812static struct key_vector *resize(struct trie *t, struct key_vector *tn) 813{ 814#ifdef CONFIG_IP_FIB_TRIE_STATS 815 struct trie_use_stats __percpu *stats = t->stats; 816#endif 817 struct key_vector *tp = node_parent(tn); 818 unsigned long cindex = get_index(tn->key, tp); 819 int max_work = MAX_WORK; 820 821 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n", 822 tn, inflate_threshold, halve_threshold); 823 824 /* track the tnode via the pointer from the parent instead of 825 * doing it ourselves. This way we can let RCU fully do its 826 * thing without us interfering 827 */ 828 BUG_ON(tn != get_child(tp, cindex)); 829 830 /* Double as long as the resulting node has a number of 831 * nonempty nodes that are above the threshold. 832 */ 833 while (should_inflate(tp, tn) && max_work) { 834 tp = inflate(t, tn); 835 if (!tp) { 836#ifdef CONFIG_IP_FIB_TRIE_STATS 837 this_cpu_inc(stats->resize_node_skipped); 838#endif 839 break; 840 } 841 842 max_work--; 843 tn = get_child(tp, cindex); 844 } 845 846 /* update parent in case inflate failed */ 847 tp = node_parent(tn); 848 849 /* Return if at least one inflate is run */ 850 if (max_work != MAX_WORK) 851 return tp; 852 853 /* Halve as long as the number of empty children in this 854 * node is above threshold. 855 */ 856 while (should_halve(tp, tn) && max_work) { 857 tp = halve(t, tn); 858 if (!tp) { 859#ifdef CONFIG_IP_FIB_TRIE_STATS 860 this_cpu_inc(stats->resize_node_skipped); 861#endif 862 break; 863 } 864 865 max_work--; 866 tn = get_child(tp, cindex); 867 } 868 869 /* Only one child remains */ 870 if (should_collapse(tn)) 871 return collapse(t, tn); 872 873 /* update parent in case halve failed */ 874 tp = node_parent(tn); 875 876 /* Return if at least one deflate was run */ 877 if (max_work != MAX_WORK) 878 return tp; 879 880 /* push the suffix length to the parent node */ 881 if (tn->slen > tn->pos) { 882 unsigned char slen = update_suffix(tn); 883 884 if (slen > tp->slen) 885 tp->slen = slen; 886 } 887 888 return tp; 889} 890 891static void leaf_pull_suffix(struct key_vector *tp, struct key_vector *l) 892{ 893 while ((tp->slen > tp->pos) && (tp->slen > l->slen)) { 894 if (update_suffix(tp) > l->slen) 895 break; 896 tp = node_parent(tp); 897 } 898} 899 900static void leaf_push_suffix(struct key_vector *tn, struct key_vector *l) 901{ 902 /* if this is a new leaf then tn will be NULL and we can sort 903 * out parent suffix lengths as a part of trie_rebalance 904 */ 905 while (tn->slen < l->slen) { 906 tn->slen = l->slen; 907 tn = node_parent(tn); 908 } 909} 910 911/* rcu_read_lock needs to be hold by caller from readside */ 912static struct key_vector *fib_find_node(struct trie *t, 913 struct key_vector **tp, u32 key) 914{ 915 struct key_vector *pn, *n = t->kv; 916 unsigned long index = 0; 917 918 do { 919 pn = n; 920 n = get_child_rcu(n, index); 921 922 if (!n) 923 break; 924 925 index = get_cindex(key, n); 926 927 /* This bit of code is a bit tricky but it combines multiple 928 * checks into a single check. The prefix consists of the 929 * prefix plus zeros for the bits in the cindex. The index 930 * is the difference between the key and this value. From 931 * this we can actually derive several pieces of data. 932 * if (index >= (1ul << bits)) 933 * we have a mismatch in skip bits and failed 934 * else 935 * we know the value is cindex 936 * 937 * This check is safe even if bits == KEYLENGTH due to the 938 * fact that we can only allocate a node with 32 bits if a 939 * long is greater than 32 bits. 940 */ 941 if (index >= (1ul << n->bits)) { 942 n = NULL; 943 break; 944 } 945 946 /* keep searching until we find a perfect match leaf or NULL */ 947 } while (IS_TNODE(n)); 948 949 *tp = pn; 950 951 return n; 952} 953 954/* Return the first fib alias matching TOS with 955 * priority less than or equal to PRIO. 956 */ 957static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen, 958 u8 tos, u32 prio, u32 tb_id) 959{ 960 struct fib_alias *fa; 961 962 if (!fah) 963 return NULL; 964 965 hlist_for_each_entry(fa, fah, fa_list) { 966 if (fa->fa_slen < slen) 967 continue; 968 if (fa->fa_slen != slen) 969 break; 970 if (fa->tb_id > tb_id) 971 continue; 972 if (fa->tb_id != tb_id) 973 break; 974 if (fa->fa_tos > tos) 975 continue; 976 if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos) 977 return fa; 978 } 979 980 return NULL; 981} 982 983static void trie_rebalance(struct trie *t, struct key_vector *tn) 984{ 985 while (!IS_TRIE(tn)) 986 tn = resize(t, tn); 987} 988 989static int fib_insert_node(struct trie *t, struct key_vector *tp, 990 struct fib_alias *new, t_key key) 991{ 992 struct key_vector *n, *l; 993 994 l = leaf_new(key, new); 995 if (!l) 996 goto noleaf; 997 998 /* retrieve child from parent node */ 999 n = get_child(tp, get_index(key, tp)); 1000 1001 /* Case 2: n is a LEAF or a TNODE and the key doesn't match. 1002 * 1003 * Add a new tnode here 1004 * first tnode need some special handling 1005 * leaves us in position for handling as case 3 1006 */ 1007 if (n) { 1008 struct key_vector *tn; 1009 1010 tn = tnode_new(key, __fls(key ^ n->key), 1); 1011 if (!tn) 1012 goto notnode; 1013 1014 /* initialize routes out of node */ 1015 NODE_INIT_PARENT(tn, tp); 1016 put_child(tn, get_index(key, tn) ^ 1, n); 1017 1018 /* start adding routes into the node */ 1019 put_child_root(tp, key, tn); 1020 node_set_parent(n, tn); 1021 1022 /* parent now has a NULL spot where the leaf can go */ 1023 tp = tn; 1024 } 1025 1026 /* Case 3: n is NULL, and will just insert a new leaf */ 1027 NODE_INIT_PARENT(l, tp); 1028 put_child_root(tp, key, l); 1029 trie_rebalance(t, tp); 1030 1031 return 0; 1032notnode: 1033 node_free(l); 1034noleaf: 1035 return -ENOMEM; 1036} 1037 1038static int fib_insert_alias(struct trie *t, struct key_vector *tp, 1039 struct key_vector *l, struct fib_alias *new, 1040 struct fib_alias *fa, t_key key) 1041{ 1042 if (!l) 1043 return fib_insert_node(t, tp, new, key); 1044 1045 if (fa) { 1046 hlist_add_before_rcu(&new->fa_list, &fa->fa_list); 1047 } else { 1048 struct fib_alias *last; 1049 1050 hlist_for_each_entry(last, &l->leaf, fa_list) { 1051 if (new->fa_slen < last->fa_slen) 1052 break; 1053 if ((new->fa_slen == last->fa_slen) && 1054 (new->tb_id > last->tb_id)) 1055 break; 1056 fa = last; 1057 } 1058 1059 if (fa) 1060 hlist_add_behind_rcu(&new->fa_list, &fa->fa_list); 1061 else 1062 hlist_add_head_rcu(&new->fa_list, &l->leaf); 1063 } 1064 1065 /* if we added to the tail node then we need to update slen */ 1066 if (l->slen < new->fa_slen) { 1067 l->slen = new->fa_slen; 1068 leaf_push_suffix(tp, l); 1069 } 1070 1071 return 0; 1072} 1073 1074/* Caller must hold RTNL. */ 1075int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) 1076{ 1077 struct trie *t = (struct trie *)tb->tb_data; 1078 struct fib_alias *fa, *new_fa; 1079 struct key_vector *l, *tp; 1080 struct fib_info *fi; 1081 u8 plen = cfg->fc_dst_len; 1082 u8 slen = KEYLENGTH - plen; 1083 u8 tos = cfg->fc_tos; 1084 u32 key; 1085 int err; 1086 1087 if (plen > KEYLENGTH) 1088 return -EINVAL; 1089 1090 key = ntohl(cfg->fc_dst); 1091 1092 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen); 1093 1094 if ((plen < KEYLENGTH) && (key << plen)) 1095 return -EINVAL; 1096 1097 fi = fib_create_info(cfg); 1098 if (IS_ERR(fi)) { 1099 err = PTR_ERR(fi); 1100 goto err; 1101 } 1102 1103 l = fib_find_node(t, &tp, key); 1104 fa = l ? fib_find_alias(&l->leaf, slen, tos, fi->fib_priority, 1105 tb->tb_id) : NULL; 1106 1107 /* Now fa, if non-NULL, points to the first fib alias 1108 * with the same keys [prefix,tos,priority], if such key already 1109 * exists or to the node before which we will insert new one. 1110 * 1111 * If fa is NULL, we will need to allocate a new one and 1112 * insert to the tail of the section matching the suffix length 1113 * of the new alias. 1114 */ 1115 1116 if (fa && fa->fa_tos == tos && 1117 fa->fa_info->fib_priority == fi->fib_priority) { 1118 struct fib_alias *fa_first, *fa_match; 1119 1120 err = -EEXIST; 1121 if (cfg->fc_nlflags & NLM_F_EXCL) 1122 goto out; 1123 1124 /* We have 2 goals: 1125 * 1. Find exact match for type, scope, fib_info to avoid 1126 * duplicate routes 1127 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it 1128 */ 1129 fa_match = NULL; 1130 fa_first = fa; 1131 hlist_for_each_entry_from(fa, fa_list) { 1132 if ((fa->fa_slen != slen) || 1133 (fa->tb_id != tb->tb_id) || 1134 (fa->fa_tos != tos)) 1135 break; 1136 if (fa->fa_info->fib_priority != fi->fib_priority) 1137 break; 1138 if (fa->fa_type == cfg->fc_type && 1139 fa->fa_info == fi) { 1140 fa_match = fa; 1141 break; 1142 } 1143 } 1144 1145 if (cfg->fc_nlflags & NLM_F_REPLACE) { 1146 struct fib_info *fi_drop; 1147 u8 state; 1148 1149 fa = fa_first; 1150 if (fa_match) { 1151 if (fa == fa_match) 1152 err = 0; 1153 goto out; 1154 } 1155 err = -ENOBUFS; 1156 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1157 if (!new_fa) 1158 goto out; 1159 1160 fi_drop = fa->fa_info; 1161 new_fa->fa_tos = fa->fa_tos; 1162 new_fa->fa_info = fi; 1163 new_fa->fa_type = cfg->fc_type; 1164 state = fa->fa_state; 1165 new_fa->fa_state = state & ~FA_S_ACCESSED; 1166 new_fa->fa_slen = fa->fa_slen; 1167 new_fa->tb_id = tb->tb_id; 1168 1169 err = netdev_switch_fib_ipv4_add(key, plen, fi, 1170 new_fa->fa_tos, 1171 cfg->fc_type, 1172 cfg->fc_nlflags, 1173 tb->tb_id); 1174 if (err) { 1175 netdev_switch_fib_ipv4_abort(fi); 1176 kmem_cache_free(fn_alias_kmem, new_fa); 1177 goto out; 1178 } 1179 1180 hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list); 1181 1182 alias_free_mem_rcu(fa); 1183 1184 fib_release_info(fi_drop); 1185 if (state & FA_S_ACCESSED) 1186 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1187 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, 1188 tb->tb_id, &cfg->fc_nlinfo, NLM_F_REPLACE); 1189 1190 goto succeeded; 1191 } 1192 /* Error if we find a perfect match which 1193 * uses the same scope, type, and nexthop 1194 * information. 1195 */ 1196 if (fa_match) 1197 goto out; 1198 1199 if (!(cfg->fc_nlflags & NLM_F_APPEND)) 1200 fa = fa_first; 1201 } 1202 err = -ENOENT; 1203 if (!(cfg->fc_nlflags & NLM_F_CREATE)) 1204 goto out; 1205 1206 err = -ENOBUFS; 1207 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1208 if (!new_fa) 1209 goto out; 1210 1211 new_fa->fa_info = fi; 1212 new_fa->fa_tos = tos; 1213 new_fa->fa_type = cfg->fc_type; 1214 new_fa->fa_state = 0; 1215 new_fa->fa_slen = slen; 1216 new_fa->tb_id = tb->tb_id; 1217 1218 /* (Optionally) offload fib entry to switch hardware. */ 1219 err = netdev_switch_fib_ipv4_add(key, plen, fi, tos, 1220 cfg->fc_type, 1221 cfg->fc_nlflags, 1222 tb->tb_id); 1223 if (err) { 1224 netdev_switch_fib_ipv4_abort(fi); 1225 goto out_free_new_fa; 1226 } 1227 1228 /* Insert new entry to the list. */ 1229 err = fib_insert_alias(t, tp, l, new_fa, fa, key); 1230 if (err) 1231 goto out_sw_fib_del; 1232 1233 if (!plen) 1234 tb->tb_num_default++; 1235 1236 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1237 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id, 1238 &cfg->fc_nlinfo, 0); 1239succeeded: 1240 return 0; 1241 1242out_sw_fib_del: 1243 netdev_switch_fib_ipv4_del(key, plen, fi, tos, cfg->fc_type, tb->tb_id); 1244out_free_new_fa: 1245 kmem_cache_free(fn_alias_kmem, new_fa); 1246out: 1247 fib_release_info(fi); 1248err: 1249 return err; 1250} 1251 1252static inline t_key prefix_mismatch(t_key key, struct key_vector *n) 1253{ 1254 t_key prefix = n->key; 1255 1256 return (key ^ prefix) & (prefix | -prefix); 1257} 1258 1259/* should be called with rcu_read_lock */ 1260int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 1261 struct fib_result *res, int fib_flags) 1262{ 1263 struct trie *t = (struct trie *) tb->tb_data; 1264#ifdef CONFIG_IP_FIB_TRIE_STATS 1265 struct trie_use_stats __percpu *stats = t->stats; 1266#endif 1267 const t_key key = ntohl(flp->daddr); 1268 struct key_vector *n, *pn; 1269 struct fib_alias *fa; 1270 unsigned long index; 1271 t_key cindex; 1272 1273 pn = t->kv; 1274 cindex = 0; 1275 1276 n = get_child_rcu(pn, cindex); 1277 if (!n) 1278 return -EAGAIN; 1279 1280#ifdef CONFIG_IP_FIB_TRIE_STATS 1281 this_cpu_inc(stats->gets); 1282#endif 1283 1284 /* Step 1: Travel to the longest prefix match in the trie */ 1285 for (;;) { 1286 index = get_cindex(key, n); 1287 1288 /* This bit of code is a bit tricky but it combines multiple 1289 * checks into a single check. The prefix consists of the 1290 * prefix plus zeros for the "bits" in the prefix. The index 1291 * is the difference between the key and this value. From 1292 * this we can actually derive several pieces of data. 1293 * if (index >= (1ul << bits)) 1294 * we have a mismatch in skip bits and failed 1295 * else 1296 * we know the value is cindex 1297 * 1298 * This check is safe even if bits == KEYLENGTH due to the 1299 * fact that we can only allocate a node with 32 bits if a 1300 * long is greater than 32 bits. 1301 */ 1302 if (index >= (1ul << n->bits)) 1303 break; 1304 1305 /* we have found a leaf. Prefixes have already been compared */ 1306 if (IS_LEAF(n)) 1307 goto found; 1308 1309 /* only record pn and cindex if we are going to be chopping 1310 * bits later. Otherwise we are just wasting cycles. 1311 */ 1312 if (n->slen > n->pos) { 1313 pn = n; 1314 cindex = index; 1315 } 1316 1317 n = get_child_rcu(n, index); 1318 if (unlikely(!n)) 1319 goto backtrace; 1320 } 1321 1322 /* Step 2: Sort out leaves and begin backtracing for longest prefix */ 1323 for (;;) { 1324 /* record the pointer where our next node pointer is stored */ 1325 struct key_vector __rcu **cptr = n->tnode; 1326 1327 /* This test verifies that none of the bits that differ 1328 * between the key and the prefix exist in the region of 1329 * the lsb and higher in the prefix. 1330 */ 1331 if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos)) 1332 goto backtrace; 1333 1334 /* exit out and process leaf */ 1335 if (unlikely(IS_LEAF(n))) 1336 break; 1337 1338 /* Don't bother recording parent info. Since we are in 1339 * prefix match mode we will have to come back to wherever 1340 * we started this traversal anyway 1341 */ 1342 1343 while ((n = rcu_dereference(*cptr)) == NULL) { 1344backtrace: 1345#ifdef CONFIG_IP_FIB_TRIE_STATS 1346 if (!n) 1347 this_cpu_inc(stats->null_node_hit); 1348#endif 1349 /* If we are at cindex 0 there are no more bits for 1350 * us to strip at this level so we must ascend back 1351 * up one level to see if there are any more bits to 1352 * be stripped there. 1353 */ 1354 while (!cindex) { 1355 t_key pkey = pn->key; 1356 1357 /* If we don't have a parent then there is 1358 * nothing for us to do as we do not have any 1359 * further nodes to parse. 1360 */ 1361 if (IS_TRIE(pn)) 1362 return -EAGAIN; 1363#ifdef CONFIG_IP_FIB_TRIE_STATS 1364 this_cpu_inc(stats->backtrack); 1365#endif 1366 /* Get Child's index */ 1367 pn = node_parent_rcu(pn); 1368 cindex = get_index(pkey, pn); 1369 } 1370 1371 /* strip the least significant bit from the cindex */ 1372 cindex &= cindex - 1; 1373 1374 /* grab pointer for next child node */ 1375 cptr = &pn->tnode[cindex]; 1376 } 1377 } 1378 1379found: 1380 /* this line carries forward the xor from earlier in the function */ 1381 index = key ^ n->key; 1382 1383 /* Step 3: Process the leaf, if that fails fall back to backtracing */ 1384 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) { 1385 struct fib_info *fi = fa->fa_info; 1386 int nhsel, err; 1387 1388 if ((index >= (1ul << fa->fa_slen)) && 1389 ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen != KEYLENGTH))) 1390 continue; 1391 if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos) 1392 continue; 1393 if (fi->fib_dead) 1394 continue; 1395 if (fa->fa_info->fib_scope < flp->flowi4_scope) 1396 continue; 1397 fib_alias_accessed(fa); 1398 err = fib_props[fa->fa_type].error; 1399 if (unlikely(err < 0)) { 1400#ifdef CONFIG_IP_FIB_TRIE_STATS 1401 this_cpu_inc(stats->semantic_match_passed); 1402#endif 1403 return err; 1404 } 1405 if (fi->fib_flags & RTNH_F_DEAD) 1406 continue; 1407 for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) { 1408 const struct fib_nh *nh = &fi->fib_nh[nhsel]; 1409 1410 if (nh->nh_flags & RTNH_F_DEAD) 1411 continue; 1412 if (flp->flowi4_oif && flp->flowi4_oif != nh->nh_oif) 1413 continue; 1414 1415 if (!(fib_flags & FIB_LOOKUP_NOREF)) 1416 atomic_inc(&fi->fib_clntref); 1417 1418 res->prefixlen = KEYLENGTH - fa->fa_slen; 1419 res->nh_sel = nhsel; 1420 res->type = fa->fa_type; 1421 res->scope = fi->fib_scope; 1422 res->fi = fi; 1423 res->table = tb; 1424 res->fa_head = &n->leaf; 1425#ifdef CONFIG_IP_FIB_TRIE_STATS 1426 this_cpu_inc(stats->semantic_match_passed); 1427#endif 1428 return err; 1429 } 1430 } 1431#ifdef CONFIG_IP_FIB_TRIE_STATS 1432 this_cpu_inc(stats->semantic_match_miss); 1433#endif 1434 goto backtrace; 1435} 1436EXPORT_SYMBOL_GPL(fib_table_lookup); 1437 1438static void fib_remove_alias(struct trie *t, struct key_vector *tp, 1439 struct key_vector *l, struct fib_alias *old) 1440{ 1441 /* record the location of the previous list_info entry */ 1442 struct hlist_node **pprev = old->fa_list.pprev; 1443 struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next); 1444 1445 /* remove the fib_alias from the list */ 1446 hlist_del_rcu(&old->fa_list); 1447 1448 /* if we emptied the list this leaf will be freed and we can sort 1449 * out parent suffix lengths as a part of trie_rebalance 1450 */ 1451 if (hlist_empty(&l->leaf)) { 1452 put_child_root(tp, l->key, NULL); 1453 node_free(l); 1454 trie_rebalance(t, tp); 1455 return; 1456 } 1457 1458 /* only access fa if it is pointing at the last valid hlist_node */ 1459 if (*pprev) 1460 return; 1461 1462 /* update the trie with the latest suffix length */ 1463 l->slen = fa->fa_slen; 1464 leaf_pull_suffix(tp, l); 1465} 1466 1467/* Caller must hold RTNL. */ 1468int fib_table_delete(struct fib_table *tb, struct fib_config *cfg) 1469{ 1470 struct trie *t = (struct trie *) tb->tb_data; 1471 struct fib_alias *fa, *fa_to_delete; 1472 struct key_vector *l, *tp; 1473 u8 plen = cfg->fc_dst_len; 1474 u8 slen = KEYLENGTH - plen; 1475 u8 tos = cfg->fc_tos; 1476 u32 key; 1477 1478 if (plen > KEYLENGTH) 1479 return -EINVAL; 1480 1481 key = ntohl(cfg->fc_dst); 1482 1483 if ((plen < KEYLENGTH) && (key << plen)) 1484 return -EINVAL; 1485 1486 l = fib_find_node(t, &tp, key); 1487 if (!l) 1488 return -ESRCH; 1489 1490 fa = fib_find_alias(&l->leaf, slen, tos, 0, tb->tb_id); 1491 if (!fa) 1492 return -ESRCH; 1493 1494 pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t); 1495 1496 fa_to_delete = NULL; 1497 hlist_for_each_entry_from(fa, fa_list) { 1498 struct fib_info *fi = fa->fa_info; 1499 1500 if ((fa->fa_slen != slen) || 1501 (fa->tb_id != tb->tb_id) || 1502 (fa->fa_tos != tos)) 1503 break; 1504 1505 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) && 1506 (cfg->fc_scope == RT_SCOPE_NOWHERE || 1507 fa->fa_info->fib_scope == cfg->fc_scope) && 1508 (!cfg->fc_prefsrc || 1509 fi->fib_prefsrc == cfg->fc_prefsrc) && 1510 (!cfg->fc_protocol || 1511 fi->fib_protocol == cfg->fc_protocol) && 1512 fib_nh_match(cfg, fi) == 0) { 1513 fa_to_delete = fa; 1514 break; 1515 } 1516 } 1517 1518 if (!fa_to_delete) 1519 return -ESRCH; 1520 1521 netdev_switch_fib_ipv4_del(key, plen, fa_to_delete->fa_info, tos, 1522 cfg->fc_type, tb->tb_id); 1523 1524 rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id, 1525 &cfg->fc_nlinfo, 0); 1526 1527 if (!plen) 1528 tb->tb_num_default--; 1529 1530 fib_remove_alias(t, tp, l, fa_to_delete); 1531 1532 if (fa_to_delete->fa_state & FA_S_ACCESSED) 1533 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1534 1535 fib_release_info(fa_to_delete->fa_info); 1536 alias_free_mem_rcu(fa_to_delete); 1537 return 0; 1538} 1539 1540/* Scan for the next leaf starting at the provided key value */ 1541static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key) 1542{ 1543 struct key_vector *pn, *n = *tn; 1544 unsigned long cindex; 1545 1546 /* this loop is meant to try and find the key in the trie */ 1547 do { 1548 /* record parent and next child index */ 1549 pn = n; 1550 cindex = (key > pn->key) ? get_index(key, pn) : 0; 1551 1552 if (cindex >> pn->bits) 1553 break; 1554 1555 /* descend into the next child */ 1556 n = get_child_rcu(pn, cindex++); 1557 if (!n) 1558 break; 1559 1560 /* guarantee forward progress on the keys */ 1561 if (IS_LEAF(n) && (n->key >= key)) 1562 goto found; 1563 } while (IS_TNODE(n)); 1564 1565 /* this loop will search for the next leaf with a greater key */ 1566 while (!IS_TRIE(pn)) { 1567 /* if we exhausted the parent node we will need to climb */ 1568 if (cindex >= (1ul << pn->bits)) { 1569 t_key pkey = pn->key; 1570 1571 pn = node_parent_rcu(pn); 1572 cindex = get_index(pkey, pn) + 1; 1573 continue; 1574 } 1575 1576 /* grab the next available node */ 1577 n = get_child_rcu(pn, cindex++); 1578 if (!n) 1579 continue; 1580 1581 /* no need to compare keys since we bumped the index */ 1582 if (IS_LEAF(n)) 1583 goto found; 1584 1585 /* Rescan start scanning in new node */ 1586 pn = n; 1587 cindex = 0; 1588 } 1589 1590 *tn = pn; 1591 return NULL; /* Root of trie */ 1592found: 1593 /* if we are at the limit for keys just return NULL for the tnode */ 1594 *tn = pn; 1595 return n; 1596} 1597 1598static void fib_trie_free(struct fib_table *tb) 1599{ 1600 struct trie *t = (struct trie *)tb->tb_data; 1601 struct key_vector *pn = t->kv; 1602 unsigned long cindex = 1; 1603 struct hlist_node *tmp; 1604 struct fib_alias *fa; 1605 1606 /* walk trie in reverse order and free everything */ 1607 for (;;) { 1608 struct key_vector *n; 1609 1610 if (!(cindex--)) { 1611 t_key pkey = pn->key; 1612 1613 if (IS_TRIE(pn)) 1614 break; 1615 1616 n = pn; 1617 pn = node_parent(pn); 1618 1619 /* drop emptied tnode */ 1620 put_child_root(pn, n->key, NULL); 1621 node_free(n); 1622 1623 cindex = get_index(pkey, pn); 1624 1625 continue; 1626 } 1627 1628 /* grab the next available node */ 1629 n = get_child(pn, cindex); 1630 if (!n) 1631 continue; 1632 1633 if (IS_TNODE(n)) { 1634 /* record pn and cindex for leaf walking */ 1635 pn = n; 1636 cindex = 1ul << n->bits; 1637 1638 continue; 1639 } 1640 1641 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 1642 hlist_del_rcu(&fa->fa_list); 1643 alias_free_mem_rcu(fa); 1644 } 1645 1646 put_child_root(pn, n->key, NULL); 1647 node_free(n); 1648 } 1649 1650#ifdef CONFIG_IP_FIB_TRIE_STATS 1651 free_percpu(t->stats); 1652#endif 1653 kfree(tb); 1654} 1655 1656struct fib_table *fib_trie_unmerge(struct fib_table *oldtb) 1657{ 1658 struct trie *ot = (struct trie *)oldtb->tb_data; 1659 struct key_vector *l, *tp = ot->kv; 1660 struct fib_table *local_tb; 1661 struct fib_alias *fa; 1662 struct trie *lt; 1663 t_key key = 0; 1664 1665 if (oldtb->tb_data == oldtb->__data) 1666 return oldtb; 1667 1668 local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL); 1669 if (!local_tb) 1670 return NULL; 1671 1672 lt = (struct trie *)local_tb->tb_data; 1673 1674 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 1675 struct key_vector *local_l = NULL, *local_tp; 1676 1677 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 1678 struct fib_alias *new_fa; 1679 1680 if (local_tb->tb_id != fa->tb_id) 1681 continue; 1682 1683 /* clone fa for new local table */ 1684 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1685 if (!new_fa) 1686 goto out; 1687 1688 memcpy(new_fa, fa, sizeof(*fa)); 1689 1690 /* insert clone into table */ 1691 if (!local_l) 1692 local_l = fib_find_node(lt, &local_tp, l->key); 1693 1694 if (fib_insert_alias(lt, local_tp, local_l, new_fa, 1695 NULL, l->key)) 1696 goto out; 1697 } 1698 1699 /* stop loop if key wrapped back to 0 */ 1700 key = l->key + 1; 1701 if (key < l->key) 1702 break; 1703 } 1704 1705 return local_tb; 1706out: 1707 fib_trie_free(local_tb); 1708 1709 return NULL; 1710} 1711 1712/* Caller must hold RTNL */ 1713void fib_table_flush_external(struct fib_table *tb) 1714{ 1715 struct trie *t = (struct trie *)tb->tb_data; 1716 struct key_vector *pn = t->kv; 1717 unsigned long cindex = 1; 1718 struct hlist_node *tmp; 1719 struct fib_alias *fa; 1720 1721 /* walk trie in reverse order */ 1722 for (;;) { 1723 unsigned char slen = 0; 1724 struct key_vector *n; 1725 1726 if (!(cindex--)) { 1727 t_key pkey = pn->key; 1728 1729 /* cannot resize the trie vector */ 1730 if (IS_TRIE(pn)) 1731 break; 1732 1733 /* resize completed node */ 1734 pn = resize(t, pn); 1735 cindex = get_index(pkey, pn); 1736 1737 continue; 1738 } 1739 1740 /* grab the next available node */ 1741 n = get_child(pn, cindex); 1742 if (!n) 1743 continue; 1744 1745 if (IS_TNODE(n)) { 1746 /* record pn and cindex for leaf walking */ 1747 pn = n; 1748 cindex = 1ul << n->bits; 1749 1750 continue; 1751 } 1752 1753 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 1754 struct fib_info *fi = fa->fa_info; 1755 1756 /* if alias was cloned to local then we just 1757 * need to remove the local copy from main 1758 */ 1759 if (tb->tb_id != fa->tb_id) { 1760 hlist_del_rcu(&fa->fa_list); 1761 alias_free_mem_rcu(fa); 1762 continue; 1763 } 1764 1765 /* record local slen */ 1766 slen = fa->fa_slen; 1767 1768 if (!fi || !(fi->fib_flags & RTNH_F_OFFLOAD)) 1769 continue; 1770 1771 netdev_switch_fib_ipv4_del(n->key, 1772 KEYLENGTH - fa->fa_slen, 1773 fi, fa->fa_tos, 1774 fa->fa_type, tb->tb_id); 1775 } 1776 1777 /* update leaf slen */ 1778 n->slen = slen; 1779 1780 if (hlist_empty(&n->leaf)) { 1781 put_child_root(pn, n->key, NULL); 1782 node_free(n); 1783 } 1784 } 1785} 1786 1787/* Caller must hold RTNL. */ 1788int fib_table_flush(struct fib_table *tb) 1789{ 1790 struct trie *t = (struct trie *)tb->tb_data; 1791 struct key_vector *pn = t->kv; 1792 unsigned long cindex = 1; 1793 struct hlist_node *tmp; 1794 struct fib_alias *fa; 1795 int found = 0; 1796 1797 /* walk trie in reverse order */ 1798 for (;;) { 1799 unsigned char slen = 0; 1800 struct key_vector *n; 1801 1802 if (!(cindex--)) { 1803 t_key pkey = pn->key; 1804 1805 /* cannot resize the trie vector */ 1806 if (IS_TRIE(pn)) 1807 break; 1808 1809 /* resize completed node */ 1810 pn = resize(t, pn); 1811 cindex = get_index(pkey, pn); 1812 1813 continue; 1814 } 1815 1816 /* grab the next available node */ 1817 n = get_child(pn, cindex); 1818 if (!n) 1819 continue; 1820 1821 if (IS_TNODE(n)) { 1822 /* record pn and cindex for leaf walking */ 1823 pn = n; 1824 cindex = 1ul << n->bits; 1825 1826 continue; 1827 } 1828 1829 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 1830 struct fib_info *fi = fa->fa_info; 1831 1832 if (!fi || !(fi->fib_flags & RTNH_F_DEAD)) { 1833 slen = fa->fa_slen; 1834 continue; 1835 } 1836 1837 netdev_switch_fib_ipv4_del(n->key, 1838 KEYLENGTH - fa->fa_slen, 1839 fi, fa->fa_tos, 1840 fa->fa_type, tb->tb_id); 1841 hlist_del_rcu(&fa->fa_list); 1842 fib_release_info(fa->fa_info); 1843 alias_free_mem_rcu(fa); 1844 found++; 1845 } 1846 1847 /* update leaf slen */ 1848 n->slen = slen; 1849 1850 if (hlist_empty(&n->leaf)) { 1851 put_child_root(pn, n->key, NULL); 1852 node_free(n); 1853 } 1854 } 1855 1856 pr_debug("trie_flush found=%d\n", found); 1857 return found; 1858} 1859 1860static void __trie_free_rcu(struct rcu_head *head) 1861{ 1862 struct fib_table *tb = container_of(head, struct fib_table, rcu); 1863#ifdef CONFIG_IP_FIB_TRIE_STATS 1864 struct trie *t = (struct trie *)tb->tb_data; 1865 1866 if (tb->tb_data == tb->__data) 1867 free_percpu(t->stats); 1868#endif /* CONFIG_IP_FIB_TRIE_STATS */ 1869 kfree(tb); 1870} 1871 1872void fib_free_table(struct fib_table *tb) 1873{ 1874 call_rcu(&tb->rcu, __trie_free_rcu); 1875} 1876 1877static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb, 1878 struct sk_buff *skb, struct netlink_callback *cb) 1879{ 1880 __be32 xkey = htonl(l->key); 1881 struct fib_alias *fa; 1882 int i, s_i; 1883 1884 s_i = cb->args[4]; 1885 i = 0; 1886 1887 /* rcu_read_lock is hold by caller */ 1888 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 1889 if (i < s_i) { 1890 i++; 1891 continue; 1892 } 1893 1894 if (tb->tb_id != fa->tb_id) { 1895 i++; 1896 continue; 1897 } 1898 1899 if (fib_dump_info(skb, NETLINK_CB(cb->skb).portid, 1900 cb->nlh->nlmsg_seq, 1901 RTM_NEWROUTE, 1902 tb->tb_id, 1903 fa->fa_type, 1904 xkey, 1905 KEYLENGTH - fa->fa_slen, 1906 fa->fa_tos, 1907 fa->fa_info, NLM_F_MULTI) < 0) { 1908 cb->args[4] = i; 1909 return -1; 1910 } 1911 i++; 1912 } 1913 1914 cb->args[4] = i; 1915 return skb->len; 1916} 1917 1918/* rcu_read_lock needs to be hold by caller from readside */ 1919int fib_table_dump(struct fib_table *tb, struct sk_buff *skb, 1920 struct netlink_callback *cb) 1921{ 1922 struct trie *t = (struct trie *)tb->tb_data; 1923 struct key_vector *l, *tp = t->kv; 1924 /* Dump starting at last key. 1925 * Note: 0.0.0.0/0 (ie default) is first key. 1926 */ 1927 int count = cb->args[2]; 1928 t_key key = cb->args[3]; 1929 1930 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 1931 if (fn_trie_dump_leaf(l, tb, skb, cb) < 0) { 1932 cb->args[3] = key; 1933 cb->args[2] = count; 1934 return -1; 1935 } 1936 1937 ++count; 1938 key = l->key + 1; 1939 1940 memset(&cb->args[4], 0, 1941 sizeof(cb->args) - 4*sizeof(cb->args[0])); 1942 1943 /* stop loop if key wrapped back to 0 */ 1944 if (key < l->key) 1945 break; 1946 } 1947 1948 cb->args[3] = key; 1949 cb->args[2] = count; 1950 1951 return skb->len; 1952} 1953 1954void __init fib_trie_init(void) 1955{ 1956 fn_alias_kmem = kmem_cache_create("ip_fib_alias", 1957 sizeof(struct fib_alias), 1958 0, SLAB_PANIC, NULL); 1959 1960 trie_leaf_kmem = kmem_cache_create("ip_fib_trie", 1961 LEAF_SIZE, 1962 0, SLAB_PANIC, NULL); 1963} 1964 1965struct fib_table *fib_trie_table(u32 id, struct fib_table *alias) 1966{ 1967 struct fib_table *tb; 1968 struct trie *t; 1969 size_t sz = sizeof(*tb); 1970 1971 if (!alias) 1972 sz += sizeof(struct trie); 1973 1974 tb = kzalloc(sz, GFP_KERNEL); 1975 if (!tb) 1976 return NULL; 1977 1978 tb->tb_id = id; 1979 tb->tb_default = -1; 1980 tb->tb_num_default = 0; 1981 tb->tb_data = (alias ? alias->__data : tb->__data); 1982 1983 if (alias) 1984 return tb; 1985 1986 t = (struct trie *) tb->tb_data; 1987 t->kv[0].pos = KEYLENGTH; 1988 t->kv[0].slen = KEYLENGTH; 1989#ifdef CONFIG_IP_FIB_TRIE_STATS 1990 t->stats = alloc_percpu(struct trie_use_stats); 1991 if (!t->stats) { 1992 kfree(tb); 1993 tb = NULL; 1994 } 1995#endif 1996 1997 return tb; 1998} 1999 2000#ifdef CONFIG_PROC_FS 2001/* Depth first Trie walk iterator */ 2002struct fib_trie_iter { 2003 struct seq_net_private p; 2004 struct fib_table *tb; 2005 struct key_vector *tnode; 2006 unsigned int index; 2007 unsigned int depth; 2008}; 2009 2010static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter) 2011{ 2012 unsigned long cindex = iter->index; 2013 struct key_vector *pn = iter->tnode; 2014 t_key pkey; 2015 2016 pr_debug("get_next iter={node=%p index=%d depth=%d}\n", 2017 iter->tnode, iter->index, iter->depth); 2018 2019 while (!IS_TRIE(pn)) { 2020 while (cindex < child_length(pn)) { 2021 struct key_vector *n = get_child_rcu(pn, cindex++); 2022 2023 if (!n) 2024 continue; 2025 2026 if (IS_LEAF(n)) { 2027 iter->tnode = pn; 2028 iter->index = cindex; 2029 } else { 2030 /* push down one level */ 2031 iter->tnode = n; 2032 iter->index = 0; 2033 ++iter->depth; 2034 } 2035 2036 return n; 2037 } 2038 2039 /* Current node exhausted, pop back up */ 2040 pkey = pn->key; 2041 pn = node_parent_rcu(pn); 2042 cindex = get_index(pkey, pn) + 1; 2043 --iter->depth; 2044 } 2045 2046 /* record root node so further searches know we are done */ 2047 iter->tnode = pn; 2048 iter->index = 0; 2049 2050 return NULL; 2051} 2052 2053static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter, 2054 struct trie *t) 2055{ 2056 struct key_vector *n, *pn = t->kv; 2057 2058 if (!t) 2059 return NULL; 2060 2061 n = rcu_dereference(pn->tnode[0]); 2062 if (!n) 2063 return NULL; 2064 2065 if (IS_TNODE(n)) { 2066 iter->tnode = n; 2067 iter->index = 0; 2068 iter->depth = 1; 2069 } else { 2070 iter->tnode = pn; 2071 iter->index = 0; 2072 iter->depth = 0; 2073 } 2074 2075 return n; 2076} 2077 2078static void trie_collect_stats(struct trie *t, struct trie_stat *s) 2079{ 2080 struct key_vector *n; 2081 struct fib_trie_iter iter; 2082 2083 memset(s, 0, sizeof(*s)); 2084 2085 rcu_read_lock(); 2086 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) { 2087 if (IS_LEAF(n)) { 2088 struct fib_alias *fa; 2089 2090 s->leaves++; 2091 s->totdepth += iter.depth; 2092 if (iter.depth > s->maxdepth) 2093 s->maxdepth = iter.depth; 2094 2095 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) 2096 ++s->prefixes; 2097 } else { 2098 s->tnodes++; 2099 if (n->bits < MAX_STAT_DEPTH) 2100 s->nodesizes[n->bits]++; 2101 s->nullpointers += tn_info(n)->empty_children; 2102 } 2103 } 2104 rcu_read_unlock(); 2105} 2106 2107/* 2108 * This outputs /proc/net/fib_triestats 2109 */ 2110static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat) 2111{ 2112 unsigned int i, max, pointers, bytes, avdepth; 2113 2114 if (stat->leaves) 2115 avdepth = stat->totdepth*100 / stat->leaves; 2116 else 2117 avdepth = 0; 2118 2119 seq_printf(seq, "\tAver depth: %u.%02d\n", 2120 avdepth / 100, avdepth % 100); 2121 seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth); 2122 2123 seq_printf(seq, "\tLeaves: %u\n", stat->leaves); 2124 bytes = LEAF_SIZE * stat->leaves; 2125 2126 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes); 2127 bytes += sizeof(struct fib_alias) * stat->prefixes; 2128 2129 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes); 2130 bytes += TNODE_SIZE(0) * stat->tnodes; 2131 2132 max = MAX_STAT_DEPTH; 2133 while (max > 0 && stat->nodesizes[max-1] == 0) 2134 max--; 2135 2136 pointers = 0; 2137 for (i = 1; i < max; i++) 2138 if (stat->nodesizes[i] != 0) { 2139 seq_printf(seq, " %u: %u", i, stat->nodesizes[i]); 2140 pointers += (1<<i) * stat->nodesizes[i]; 2141 } 2142 seq_putc(seq, '\n'); 2143 seq_printf(seq, "\tPointers: %u\n", pointers); 2144 2145 bytes += sizeof(struct key_vector *) * pointers; 2146 seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers); 2147 seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024); 2148} 2149 2150#ifdef CONFIG_IP_FIB_TRIE_STATS 2151static void trie_show_usage(struct seq_file *seq, 2152 const struct trie_use_stats __percpu *stats) 2153{ 2154 struct trie_use_stats s = { 0 }; 2155 int cpu; 2156 2157 /* loop through all of the CPUs and gather up the stats */ 2158 for_each_possible_cpu(cpu) { 2159 const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu); 2160 2161 s.gets += pcpu->gets; 2162 s.backtrack += pcpu->backtrack; 2163 s.semantic_match_passed += pcpu->semantic_match_passed; 2164 s.semantic_match_miss += pcpu->semantic_match_miss; 2165 s.null_node_hit += pcpu->null_node_hit; 2166 s.resize_node_skipped += pcpu->resize_node_skipped; 2167 } 2168 2169 seq_printf(seq, "\nCounters:\n---------\n"); 2170 seq_printf(seq, "gets = %u\n", s.gets); 2171 seq_printf(seq, "backtracks = %u\n", s.backtrack); 2172 seq_printf(seq, "semantic match passed = %u\n", 2173 s.semantic_match_passed); 2174 seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss); 2175 seq_printf(seq, "null node hit= %u\n", s.null_node_hit); 2176 seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped); 2177} 2178#endif /* CONFIG_IP_FIB_TRIE_STATS */ 2179 2180static void fib_table_print(struct seq_file *seq, struct fib_table *tb) 2181{ 2182 if (tb->tb_id == RT_TABLE_LOCAL) 2183 seq_puts(seq, "Local:\n"); 2184 else if (tb->tb_id == RT_TABLE_MAIN) 2185 seq_puts(seq, "Main:\n"); 2186 else 2187 seq_printf(seq, "Id %d:\n", tb->tb_id); 2188} 2189 2190 2191static int fib_triestat_seq_show(struct seq_file *seq, void *v) 2192{ 2193 struct net *net = (struct net *)seq->private; 2194 unsigned int h; 2195 2196 seq_printf(seq, 2197 "Basic info: size of leaf:" 2198 " %Zd bytes, size of tnode: %Zd bytes.\n", 2199 LEAF_SIZE, TNODE_SIZE(0)); 2200 2201 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2202 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2203 struct fib_table *tb; 2204 2205 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2206 struct trie *t = (struct trie *) tb->tb_data; 2207 struct trie_stat stat; 2208 2209 if (!t) 2210 continue; 2211 2212 fib_table_print(seq, tb); 2213 2214 trie_collect_stats(t, &stat); 2215 trie_show_stats(seq, &stat); 2216#ifdef CONFIG_IP_FIB_TRIE_STATS 2217 trie_show_usage(seq, t->stats); 2218#endif 2219 } 2220 } 2221 2222 return 0; 2223} 2224 2225static int fib_triestat_seq_open(struct inode *inode, struct file *file) 2226{ 2227 return single_open_net(inode, file, fib_triestat_seq_show); 2228} 2229 2230static const struct file_operations fib_triestat_fops = { 2231 .owner = THIS_MODULE, 2232 .open = fib_triestat_seq_open, 2233 .read = seq_read, 2234 .llseek = seq_lseek, 2235 .release = single_release_net, 2236}; 2237 2238static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos) 2239{ 2240 struct fib_trie_iter *iter = seq->private; 2241 struct net *net = seq_file_net(seq); 2242 loff_t idx = 0; 2243 unsigned int h; 2244 2245 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2246 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2247 struct fib_table *tb; 2248 2249 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2250 struct key_vector *n; 2251 2252 for (n = fib_trie_get_first(iter, 2253 (struct trie *) tb->tb_data); 2254 n; n = fib_trie_get_next(iter)) 2255 if (pos == idx++) { 2256 iter->tb = tb; 2257 return n; 2258 } 2259 } 2260 } 2261 2262 return NULL; 2263} 2264 2265static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos) 2266 __acquires(RCU) 2267{ 2268 rcu_read_lock(); 2269 return fib_trie_get_idx(seq, *pos); 2270} 2271 2272static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2273{ 2274 struct fib_trie_iter *iter = seq->private; 2275 struct net *net = seq_file_net(seq); 2276 struct fib_table *tb = iter->tb; 2277 struct hlist_node *tb_node; 2278 unsigned int h; 2279 struct key_vector *n; 2280 2281 ++*pos; 2282 /* next node in same table */ 2283 n = fib_trie_get_next(iter); 2284 if (n) 2285 return n; 2286 2287 /* walk rest of this hash chain */ 2288 h = tb->tb_id & (FIB_TABLE_HASHSZ - 1); 2289 while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) { 2290 tb = hlist_entry(tb_node, struct fib_table, tb_hlist); 2291 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data); 2292 if (n) 2293 goto found; 2294 } 2295 2296 /* new hash chain */ 2297 while (++h < FIB_TABLE_HASHSZ) { 2298 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2299 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2300 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data); 2301 if (n) 2302 goto found; 2303 } 2304 } 2305 return NULL; 2306 2307found: 2308 iter->tb = tb; 2309 return n; 2310} 2311 2312static void fib_trie_seq_stop(struct seq_file *seq, void *v) 2313 __releases(RCU) 2314{ 2315 rcu_read_unlock(); 2316} 2317 2318static void seq_indent(struct seq_file *seq, int n) 2319{ 2320 while (n-- > 0) 2321 seq_puts(seq, " "); 2322} 2323 2324static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s) 2325{ 2326 switch (s) { 2327 case RT_SCOPE_UNIVERSE: return "universe"; 2328 case RT_SCOPE_SITE: return "site"; 2329 case RT_SCOPE_LINK: return "link"; 2330 case RT_SCOPE_HOST: return "host"; 2331 case RT_SCOPE_NOWHERE: return "nowhere"; 2332 default: 2333 snprintf(buf, len, "scope=%d", s); 2334 return buf; 2335 } 2336} 2337 2338static const char *const rtn_type_names[__RTN_MAX] = { 2339 [RTN_UNSPEC] = "UNSPEC", 2340 [RTN_UNICAST] = "UNICAST", 2341 [RTN_LOCAL] = "LOCAL", 2342 [RTN_BROADCAST] = "BROADCAST", 2343 [RTN_ANYCAST] = "ANYCAST", 2344 [RTN_MULTICAST] = "MULTICAST", 2345 [RTN_BLACKHOLE] = "BLACKHOLE", 2346 [RTN_UNREACHABLE] = "UNREACHABLE", 2347 [RTN_PROHIBIT] = "PROHIBIT", 2348 [RTN_THROW] = "THROW", 2349 [RTN_NAT] = "NAT", 2350 [RTN_XRESOLVE] = "XRESOLVE", 2351}; 2352 2353static inline const char *rtn_type(char *buf, size_t len, unsigned int t) 2354{ 2355 if (t < __RTN_MAX && rtn_type_names[t]) 2356 return rtn_type_names[t]; 2357 snprintf(buf, len, "type %u", t); 2358 return buf; 2359} 2360 2361/* Pretty print the trie */ 2362static int fib_trie_seq_show(struct seq_file *seq, void *v) 2363{ 2364 const struct fib_trie_iter *iter = seq->private; 2365 struct key_vector *n = v; 2366 2367 if (IS_TRIE(node_parent_rcu(n))) 2368 fib_table_print(seq, iter->tb); 2369 2370 if (IS_TNODE(n)) { 2371 __be32 prf = htonl(n->key); 2372 2373 seq_indent(seq, iter->depth-1); 2374 seq_printf(seq, " +-- %pI4/%zu %u %u %u\n", 2375 &prf, KEYLENGTH - n->pos - n->bits, n->bits, 2376 tn_info(n)->full_children, 2377 tn_info(n)->empty_children); 2378 } else { 2379 __be32 val = htonl(n->key); 2380 struct fib_alias *fa; 2381 2382 seq_indent(seq, iter->depth); 2383 seq_printf(seq, " |-- %pI4\n", &val); 2384 2385 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) { 2386 char buf1[32], buf2[32]; 2387 2388 seq_indent(seq, iter->depth + 1); 2389 seq_printf(seq, " /%zu %s %s", 2390 KEYLENGTH - fa->fa_slen, 2391 rtn_scope(buf1, sizeof(buf1), 2392 fa->fa_info->fib_scope), 2393 rtn_type(buf2, sizeof(buf2), 2394 fa->fa_type)); 2395 if (fa->fa_tos) 2396 seq_printf(seq, " tos=%d", fa->fa_tos); 2397 seq_putc(seq, '\n'); 2398 } 2399 } 2400 2401 return 0; 2402} 2403 2404static const struct seq_operations fib_trie_seq_ops = { 2405 .start = fib_trie_seq_start, 2406 .next = fib_trie_seq_next, 2407 .stop = fib_trie_seq_stop, 2408 .show = fib_trie_seq_show, 2409}; 2410 2411static int fib_trie_seq_open(struct inode *inode, struct file *file) 2412{ 2413 return seq_open_net(inode, file, &fib_trie_seq_ops, 2414 sizeof(struct fib_trie_iter)); 2415} 2416 2417static const struct file_operations fib_trie_fops = { 2418 .owner = THIS_MODULE, 2419 .open = fib_trie_seq_open, 2420 .read = seq_read, 2421 .llseek = seq_lseek, 2422 .release = seq_release_net, 2423}; 2424 2425struct fib_route_iter { 2426 struct seq_net_private p; 2427 struct fib_table *main_tb; 2428 struct key_vector *tnode; 2429 loff_t pos; 2430 t_key key; 2431}; 2432 2433static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter, 2434 loff_t pos) 2435{ 2436 struct fib_table *tb = iter->main_tb; 2437 struct key_vector *l, **tp = &iter->tnode; 2438 struct trie *t; 2439 t_key key; 2440 2441 /* use cache location of next-to-find key */ 2442 if (iter->pos > 0 && pos >= iter->pos) { 2443 pos -= iter->pos; 2444 key = iter->key; 2445 } else { 2446 t = (struct trie *)tb->tb_data; 2447 iter->tnode = t->kv; 2448 iter->pos = 0; 2449 key = 0; 2450 } 2451 2452 while ((l = leaf_walk_rcu(tp, key)) != NULL) { 2453 key = l->key + 1; 2454 iter->pos++; 2455 2456 if (--pos <= 0) 2457 break; 2458 2459 l = NULL; 2460 2461 /* handle unlikely case of a key wrap */ 2462 if (!key) 2463 break; 2464 } 2465 2466 if (l) 2467 iter->key = key; /* remember it */ 2468 else 2469 iter->pos = 0; /* forget it */ 2470 2471 return l; 2472} 2473 2474static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos) 2475 __acquires(RCU) 2476{ 2477 struct fib_route_iter *iter = seq->private; 2478 struct fib_table *tb; 2479 struct trie *t; 2480 2481 rcu_read_lock(); 2482 2483 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN); 2484 if (!tb) 2485 return NULL; 2486 2487 iter->main_tb = tb; 2488 2489 if (*pos != 0) 2490 return fib_route_get_idx(iter, *pos); 2491 2492 t = (struct trie *)tb->tb_data; 2493 iter->tnode = t->kv; 2494 iter->pos = 0; 2495 iter->key = 0; 2496 2497 return SEQ_START_TOKEN; 2498} 2499 2500static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2501{ 2502 struct fib_route_iter *iter = seq->private; 2503 struct key_vector *l = NULL; 2504 t_key key = iter->key; 2505 2506 ++*pos; 2507 2508 /* only allow key of 0 for start of sequence */ 2509 if ((v == SEQ_START_TOKEN) || key) 2510 l = leaf_walk_rcu(&iter->tnode, key); 2511 2512 if (l) { 2513 iter->key = l->key + 1; 2514 iter->pos++; 2515 } else { 2516 iter->pos = 0; 2517 } 2518 2519 return l; 2520} 2521 2522static void fib_route_seq_stop(struct seq_file *seq, void *v) 2523 __releases(RCU) 2524{ 2525 rcu_read_unlock(); 2526} 2527 2528static unsigned int fib_flag_trans(int type, __be32 mask, const struct fib_info *fi) 2529{ 2530 unsigned int flags = 0; 2531 2532 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT) 2533 flags = RTF_REJECT; 2534 if (fi && fi->fib_nh->nh_gw) 2535 flags |= RTF_GATEWAY; 2536 if (mask == htonl(0xFFFFFFFF)) 2537 flags |= RTF_HOST; 2538 flags |= RTF_UP; 2539 return flags; 2540} 2541 2542/* 2543 * This outputs /proc/net/route. 2544 * The format of the file is not supposed to be changed 2545 * and needs to be same as fib_hash output to avoid breaking 2546 * legacy utilities 2547 */ 2548static int fib_route_seq_show(struct seq_file *seq, void *v) 2549{ 2550 struct fib_route_iter *iter = seq->private; 2551 struct fib_table *tb = iter->main_tb; 2552 struct fib_alias *fa; 2553 struct key_vector *l = v; 2554 __be32 prefix; 2555 2556 if (v == SEQ_START_TOKEN) { 2557 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway " 2558 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU" 2559 "\tWindow\tIRTT"); 2560 return 0; 2561 } 2562 2563 prefix = htonl(l->key); 2564 2565 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 2566 const struct fib_info *fi = fa->fa_info; 2567 __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen); 2568 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi); 2569 2570 if ((fa->fa_type == RTN_BROADCAST) || 2571 (fa->fa_type == RTN_MULTICAST)) 2572 continue; 2573 2574 if (fa->tb_id != tb->tb_id) 2575 continue; 2576 2577 seq_setwidth(seq, 127); 2578 2579 if (fi) 2580 seq_printf(seq, 2581 "%s\t%08X\t%08X\t%04X\t%d\t%u\t" 2582 "%d\t%08X\t%d\t%u\t%u", 2583 fi->fib_dev ? fi->fib_dev->name : "*", 2584 prefix, 2585 fi->fib_nh->nh_gw, flags, 0, 0, 2586 fi->fib_priority, 2587 mask, 2588 (fi->fib_advmss ? 2589 fi->fib_advmss + 40 : 0), 2590 fi->fib_window, 2591 fi->fib_rtt >> 3); 2592 else 2593 seq_printf(seq, 2594 "*\t%08X\t%08X\t%04X\t%d\t%u\t" 2595 "%d\t%08X\t%d\t%u\t%u", 2596 prefix, 0, flags, 0, 0, 0, 2597 mask, 0, 0, 0); 2598 2599 seq_pad(seq, '\n'); 2600 } 2601 2602 return 0; 2603} 2604 2605static const struct seq_operations fib_route_seq_ops = { 2606 .start = fib_route_seq_start, 2607 .next = fib_route_seq_next, 2608 .stop = fib_route_seq_stop, 2609 .show = fib_route_seq_show, 2610}; 2611 2612static int fib_route_seq_open(struct inode *inode, struct file *file) 2613{ 2614 return seq_open_net(inode, file, &fib_route_seq_ops, 2615 sizeof(struct fib_route_iter)); 2616} 2617 2618static const struct file_operations fib_route_fops = { 2619 .owner = THIS_MODULE, 2620 .open = fib_route_seq_open, 2621 .read = seq_read, 2622 .llseek = seq_lseek, 2623 .release = seq_release_net, 2624}; 2625 2626int __net_init fib_proc_init(struct net *net) 2627{ 2628 if (!proc_create("fib_trie", S_IRUGO, net->proc_net, &fib_trie_fops)) 2629 goto out1; 2630 2631 if (!proc_create("fib_triestat", S_IRUGO, net->proc_net, 2632 &fib_triestat_fops)) 2633 goto out2; 2634 2635 if (!proc_create("route", S_IRUGO, net->proc_net, &fib_route_fops)) 2636 goto out3; 2637 2638 return 0; 2639 2640out3: 2641 remove_proc_entry("fib_triestat", net->proc_net); 2642out2: 2643 remove_proc_entry("fib_trie", net->proc_net); 2644out1: 2645 return -ENOMEM; 2646} 2647 2648void __net_exit fib_proc_exit(struct net *net) 2649{ 2650 remove_proc_entry("fib_trie", net->proc_net); 2651 remove_proc_entry("fib_triestat", net->proc_net); 2652 remove_proc_entry("route", net->proc_net); 2653} 2654 2655#endif /* CONFIG_PROC_FS */ 2656