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fib_trie.c
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linux-6.19.14/net/ipv4/fib_trie.c
1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * 4 * Robert Olsson <robert.olsson@its.uu.se> Uppsala Universitet 5 * & Swedish University of Agricultural Sciences. 6 * 7 * Jens Laas <jens.laas@data.slu.se> Swedish University of 8 * Agricultural Sciences. 9 * 10 * Hans Liss <hans.liss@its.uu.se> Uppsala Universitet 11 * 12 * This work is based on the LPC-trie which is originally described in: 13 * 14 * An experimental study of compression methods for dynamic tries 15 * Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002. 16 * https://www.csc.kth.se/~snilsson/software/dyntrie2/ 17 * 18 * IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson 19 * IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999 20 * 21 * Code from fib_hash has been reused which includes the following header: 22 * 23 * INET An implementation of the TCP/IP protocol suite for the LINUX 24 * operating system. INET is implemented using the BSD Socket 25 * interface as the means of communication with the user level. 26 * 27 * IPv4 FIB: lookup engine and maintenance routines. 28 * 29 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 30 * 31 * Substantial contributions to this work comes from: 32 * 33 * David S. Miller, <davem@davemloft.net> 34 * Stephen Hemminger <shemminger@osdl.org> 35 * Paul E. McKenney <paulmck@us.ibm.com> 36 * Patrick McHardy <kaber@trash.net> 37 */ 38#include <linux/cache.h> 39#include <linux/uaccess.h> 40#include <linux/bitops.h> 41#include <linux/types.h> 42#include <linux/kernel.h> 43#include <linux/mm.h> 44#include <linux/string.h> 45#include <linux/socket.h> 46#include <linux/sockios.h> 47#include <linux/errno.h> 48#include <linux/in.h> 49#include <linux/inet.h> 50#include <linux/inetdevice.h> 51#include <linux/netdevice.h> 52#include <linux/if_arp.h> 53#include <linux/proc_fs.h> 54#include <linux/rcupdate.h> 55#include <linux/rcupdate_wait.h> 56#include <linux/skbuff.h> 57#include <linux/netlink.h> 58#include <linux/init.h> 59#include <linux/list.h> 60#include <linux/slab.h> 61#include <linux/export.h> 62#include <linux/vmalloc.h> 63#include <linux/notifier.h> 64#include <net/net_namespace.h> 65#include <net/inet_dscp.h> 66#include <net/ip.h> 67#include <net/protocol.h> 68#include <net/route.h> 69#include <net/tcp.h> 70#include <net/sock.h> 71#include <net/ip_fib.h> 72#include <net/fib_notifier.h> 73#include <trace/events/fib.h> 74#include "fib_lookup.h" 75 76static int call_fib_entry_notifier(struct notifier_block *nb, 77 enum fib_event_type event_type, u32 dst, 78 int dst_len, struct fib_alias *fa, 79 struct netlink_ext_ack *extack) 80{ 81 struct fib_entry_notifier_info info = { 82 .info.extack = extack, 83 .dst = dst, 84 .dst_len = dst_len, 85 .fi = fa->fa_info, 86 .dscp = fa->fa_dscp, 87 .type = fa->fa_type, 88 .tb_id = fa->tb_id, 89 }; 90 return call_fib4_notifier(nb, event_type, &info.info); 91} 92 93static int call_fib_entry_notifiers(struct net *net, 94 enum fib_event_type event_type, u32 dst, 95 int dst_len, struct fib_alias *fa, 96 struct netlink_ext_ack *extack) 97{ 98 struct fib_entry_notifier_info info = { 99 .info.extack = extack, 100 .dst = dst, 101 .dst_len = dst_len, 102 .fi = fa->fa_info, 103 .dscp = fa->fa_dscp, 104 .type = fa->fa_type, 105 .tb_id = fa->tb_id, 106 }; 107 return call_fib4_notifiers(net, event_type, &info.info); 108} 109 110#define MAX_STAT_DEPTH 32 111 112#define KEYLENGTH (8*sizeof(t_key)) 113#define KEY_MAX ((t_key)~0) 114 115typedef unsigned int t_key; 116 117#define IS_TRIE(n) ((n)->pos >= KEYLENGTH) 118#define IS_TNODE(n) ((n)->bits) 119#define IS_LEAF(n) (!(n)->bits) 120 121struct key_vector { 122 t_key key; 123 unsigned char pos; /* 2log(KEYLENGTH) bits needed */ 124 unsigned char bits; /* 2log(KEYLENGTH) bits needed */ 125 unsigned char slen; 126 union { 127 /* This list pointer if valid if (pos | bits) == 0 (LEAF) */ 128 struct hlist_head leaf; 129 /* This array is valid if (pos | bits) > 0 (TNODE) */ 130 DECLARE_FLEX_ARRAY(struct key_vector __rcu *, tnode); 131 }; 132}; 133 134struct tnode { 135 struct rcu_head rcu; 136 t_key empty_children; /* KEYLENGTH bits needed */ 137 t_key full_children; /* KEYLENGTH bits needed */ 138 struct key_vector __rcu *parent; 139 struct key_vector kv[1]; 140#define tn_bits kv[0].bits 141}; 142 143#define TNODE_SIZE(n) offsetof(struct tnode, kv[0].tnode[n]) 144#define LEAF_SIZE TNODE_SIZE(1) 145 146#ifdef CONFIG_IP_FIB_TRIE_STATS 147struct trie_use_stats { 148 unsigned int gets; 149 unsigned int backtrack; 150 unsigned int semantic_match_passed; 151 unsigned int semantic_match_miss; 152 unsigned int null_node_hit; 153 unsigned int resize_node_skipped; 154}; 155#endif 156 157struct trie_stat { 158 unsigned int totdepth; 159 unsigned int maxdepth; 160 unsigned int tnodes; 161 unsigned int leaves; 162 unsigned int nullpointers; 163 unsigned int prefixes; 164 unsigned int nodesizes[MAX_STAT_DEPTH]; 165}; 166 167struct trie { 168 struct key_vector kv[1]; 169#ifdef CONFIG_IP_FIB_TRIE_STATS 170 struct trie_use_stats __percpu *stats; 171#endif 172}; 173 174static struct key_vector *resize(struct trie *t, struct key_vector *tn); 175static unsigned int tnode_free_size; 176 177/* 178 * synchronize_rcu after call_rcu for outstanding dirty memory; it should be 179 * especially useful before resizing the root node with PREEMPT_NONE configs; 180 * the value was obtained experimentally, aiming to avoid visible slowdown. 181 */ 182unsigned int sysctl_fib_sync_mem = 512 * 1024; 183unsigned int sysctl_fib_sync_mem_min = 64 * 1024; 184unsigned int sysctl_fib_sync_mem_max = 64 * 1024 * 1024; 185 186static struct kmem_cache *fn_alias_kmem __ro_after_init; 187static struct kmem_cache *trie_leaf_kmem __ro_after_init; 188 189static inline struct tnode *tn_info(struct key_vector *kv) 190{ 191 return container_of(kv, struct tnode, kv[0]); 192} 193 194/* caller must hold RTNL */ 195#define node_parent(tn) rtnl_dereference(tn_info(tn)->parent) 196#define get_child(tn, i) rtnl_dereference((tn)->tnode[i]) 197 198/* caller must hold RCU read lock or RTNL */ 199#define node_parent_rcu(tn) rcu_dereference_rtnl(tn_info(tn)->parent) 200#define get_child_rcu(tn, i) rcu_dereference_rtnl((tn)->tnode[i]) 201 202/* wrapper for rcu_assign_pointer */ 203static inline void node_set_parent(struct key_vector *n, struct key_vector *tp) 204{ 205 if (n) 206 rcu_assign_pointer(tn_info(n)->parent, tp); 207} 208 209#define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER(tn_info(n)->parent, p) 210 211/* This provides us with the number of children in this node, in the case of a 212 * leaf this will return 0 meaning none of the children are accessible. 213 */ 214static inline unsigned long child_length(const struct key_vector *tn) 215{ 216 return (1ul << tn->bits) & ~(1ul); 217} 218 219#define get_cindex(key, kv) (((key) ^ (kv)->key) >> (kv)->pos) 220 221static inline unsigned long get_index(t_key key, struct key_vector *kv) 222{ 223 unsigned long index = key ^ kv->key; 224 225 if ((BITS_PER_LONG <= KEYLENGTH) && (KEYLENGTH == kv->pos)) 226 return 0; 227 228 return index >> kv->pos; 229} 230 231/* To understand this stuff, an understanding of keys and all their bits is 232 * necessary. Every node in the trie has a key associated with it, but not 233 * all of the bits in that key are significant. 234 * 235 * Consider a node 'n' and its parent 'tp'. 236 * 237 * If n is a leaf, every bit in its key is significant. Its presence is 238 * necessitated by path compression, since during a tree traversal (when 239 * searching for a leaf - unless we are doing an insertion) we will completely 240 * ignore all skipped bits we encounter. Thus we need to verify, at the end of 241 * a potentially successful search, that we have indeed been walking the 242 * correct key path. 243 * 244 * Note that we can never "miss" the correct key in the tree if present by 245 * following the wrong path. Path compression ensures that segments of the key 246 * that are the same for all keys with a given prefix are skipped, but the 247 * skipped part *is* identical for each node in the subtrie below the skipped 248 * bit! trie_insert() in this implementation takes care of that. 249 * 250 * if n is an internal node - a 'tnode' here, the various parts of its key 251 * have many different meanings. 252 * 253 * Example: 254 * _________________________________________________________________ 255 * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C | 256 * ----------------------------------------------------------------- 257 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 258 * 259 * _________________________________________________________________ 260 * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u | 261 * ----------------------------------------------------------------- 262 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 263 * 264 * tp->pos = 22 265 * tp->bits = 3 266 * n->pos = 13 267 * n->bits = 4 268 * 269 * First, let's just ignore the bits that come before the parent tp, that is 270 * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this 271 * point we do not use them for anything. 272 * 273 * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the 274 * index into the parent's child array. That is, they will be used to find 275 * 'n' among tp's children. 276 * 277 * The bits from (n->pos + n->bits) to (tp->pos - 1) - "S" - are skipped bits 278 * for the node n. 279 * 280 * All the bits we have seen so far are significant to the node n. The rest 281 * of the bits are really not needed or indeed known in n->key. 282 * 283 * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into 284 * n's child array, and will of course be different for each child. 285 * 286 * The rest of the bits, from 0 to (n->pos -1) - "u" - are completely unknown 287 * at this point. 288 */ 289 290static const int halve_threshold = 25; 291static const int inflate_threshold = 50; 292static const int halve_threshold_root = 15; 293static const int inflate_threshold_root = 30; 294 295static inline void alias_free_mem_rcu(struct fib_alias *fa) 296{ 297 kfree_rcu(fa, rcu); 298} 299 300#define TNODE_VMALLOC_MAX \ 301 ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *)) 302 303static void __node_free_rcu(struct rcu_head *head) 304{ 305 struct tnode *n = container_of(head, struct tnode, rcu); 306 307 if (!n->tn_bits) 308 kmem_cache_free(trie_leaf_kmem, n); 309 else 310 kvfree(n); 311} 312 313#define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu) 314 315static struct tnode *tnode_alloc(int bits) 316{ 317 size_t size; 318 319 /* verify bits is within bounds */ 320 if (bits > TNODE_VMALLOC_MAX) 321 return NULL; 322 323 /* determine size and verify it is non-zero and didn't overflow */ 324 size = TNODE_SIZE(1ul << bits); 325 326 if (size <= PAGE_SIZE) 327 return kzalloc(size, GFP_KERNEL); 328 else 329 return vzalloc(size); 330} 331 332static inline void empty_child_inc(struct key_vector *n) 333{ 334 tn_info(n)->empty_children++; 335 336 if (!tn_info(n)->empty_children) 337 tn_info(n)->full_children++; 338} 339 340static inline void empty_child_dec(struct key_vector *n) 341{ 342 if (!tn_info(n)->empty_children) 343 tn_info(n)->full_children--; 344 345 tn_info(n)->empty_children--; 346} 347 348static struct key_vector *leaf_new(t_key key, struct fib_alias *fa) 349{ 350 struct key_vector *l; 351 struct tnode *kv; 352 353 kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL); 354 if (!kv) 355 return NULL; 356 357 /* initialize key vector */ 358 l = kv->kv; 359 l->key = key; 360 l->pos = 0; 361 l->bits = 0; 362 l->slen = fa->fa_slen; 363 364 /* link leaf to fib alias */ 365 INIT_HLIST_HEAD(&l->leaf); 366 hlist_add_head(&fa->fa_list, &l->leaf); 367 368 return l; 369} 370 371static struct key_vector *tnode_new(t_key key, int pos, int bits) 372{ 373 unsigned int shift = pos + bits; 374 struct key_vector *tn; 375 struct tnode *tnode; 376 377 /* verify bits and pos their msb bits clear and values are valid */ 378 BUG_ON(!bits || (shift > KEYLENGTH)); 379 380 tnode = tnode_alloc(bits); 381 if (!tnode) 382 return NULL; 383 384 pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0), 385 sizeof(struct key_vector *) << bits); 386 387 if (bits == KEYLENGTH) 388 tnode->full_children = 1; 389 else 390 tnode->empty_children = 1ul << bits; 391 392 tn = tnode->kv; 393 tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0; 394 tn->pos = pos; 395 tn->bits = bits; 396 tn->slen = pos; 397 398 return tn; 399} 400 401/* Check whether a tnode 'n' is "full", i.e. it is an internal node 402 * and no bits are skipped. See discussion in dyntree paper p. 6 403 */ 404static inline int tnode_full(struct key_vector *tn, struct key_vector *n) 405{ 406 return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n); 407} 408 409/* Add a child at position i overwriting the old value. 410 * Update the value of full_children and empty_children. 411 */ 412static void put_child(struct key_vector *tn, unsigned long i, 413 struct key_vector *n) 414{ 415 struct key_vector *chi = get_child(tn, i); 416 int isfull, wasfull; 417 418 BUG_ON(i >= child_length(tn)); 419 420 /* update emptyChildren, overflow into fullChildren */ 421 if (!n && chi) 422 empty_child_inc(tn); 423 if (n && !chi) 424 empty_child_dec(tn); 425 426 /* update fullChildren */ 427 wasfull = tnode_full(tn, chi); 428 isfull = tnode_full(tn, n); 429 430 if (wasfull && !isfull) 431 tn_info(tn)->full_children--; 432 else if (!wasfull && isfull) 433 tn_info(tn)->full_children++; 434 435 if (n && (tn->slen < n->slen)) 436 tn->slen = n->slen; 437 438 rcu_assign_pointer(tn->tnode[i], n); 439} 440 441static void update_children(struct key_vector *tn) 442{ 443 unsigned long i; 444 445 /* update all of the child parent pointers */ 446 for (i = child_length(tn); i;) { 447 struct key_vector *inode = get_child(tn, --i); 448 449 if (!inode) 450 continue; 451 452 /* Either update the children of a tnode that 453 * already belongs to us or update the child 454 * to point to ourselves. 455 */ 456 if (node_parent(inode) == tn) 457 update_children(inode); 458 else 459 node_set_parent(inode, tn); 460 } 461} 462 463static inline void put_child_root(struct key_vector *tp, t_key key, 464 struct key_vector *n) 465{ 466 if (IS_TRIE(tp)) 467 rcu_assign_pointer(tp->tnode[0], n); 468 else 469 put_child(tp, get_index(key, tp), n); 470} 471 472static inline void tnode_free_init(struct key_vector *tn) 473{ 474 tn_info(tn)->rcu.next = NULL; 475} 476 477static inline void tnode_free_append(struct key_vector *tn, 478 struct key_vector *n) 479{ 480 tn_info(n)->rcu.next = tn_info(tn)->rcu.next; 481 tn_info(tn)->rcu.next = &tn_info(n)->rcu; 482} 483 484static void tnode_free(struct key_vector *tn) 485{ 486 struct callback_head *head = &tn_info(tn)->rcu; 487 488 while (head) { 489 head = head->next; 490 tnode_free_size += TNODE_SIZE(1ul << tn->bits); 491 node_free(tn); 492 493 tn = container_of(head, struct tnode, rcu)->kv; 494 } 495 496 if (tnode_free_size >= READ_ONCE(sysctl_fib_sync_mem)) { 497 tnode_free_size = 0; 498 synchronize_net(); 499 } 500} 501 502static struct key_vector *replace(struct trie *t, 503 struct key_vector *oldtnode, 504 struct key_vector *tn) 505{ 506 struct key_vector *tp = node_parent(oldtnode); 507 unsigned long i; 508 509 /* setup the parent pointer out of and back into this node */ 510 NODE_INIT_PARENT(tn, tp); 511 put_child_root(tp, tn->key, tn); 512 513 /* update all of the child parent pointers */ 514 update_children(tn); 515 516 /* all pointers should be clean so we are done */ 517 tnode_free(oldtnode); 518 519 /* resize children now that oldtnode is freed */ 520 for (i = child_length(tn); i;) { 521 struct key_vector *inode = get_child(tn, --i); 522 523 /* resize child node */ 524 if (tnode_full(tn, inode)) 525 tn = resize(t, inode); 526 } 527 528 return tp; 529} 530 531static struct key_vector *inflate(struct trie *t, 532 struct key_vector *oldtnode) 533{ 534 struct key_vector *tn; 535 unsigned long i; 536 t_key m; 537 538 pr_debug("In inflate\n"); 539 540 tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1); 541 if (!tn) 542 goto notnode; 543 544 /* prepare oldtnode to be freed */ 545 tnode_free_init(oldtnode); 546 547 /* Assemble all of the pointers in our cluster, in this case that 548 * represents all of the pointers out of our allocated nodes that 549 * point to existing tnodes and the links between our allocated 550 * nodes. 551 */ 552 for (i = child_length(oldtnode), m = 1u << tn->pos; i;) { 553 struct key_vector *inode = get_child(oldtnode, --i); 554 struct key_vector *node0, *node1; 555 unsigned long j, k; 556 557 /* An empty child */ 558 if (!inode) 559 continue; 560 561 /* A leaf or an internal node with skipped bits */ 562 if (!tnode_full(oldtnode, inode)) { 563 put_child(tn, get_index(inode->key, tn), inode); 564 continue; 565 } 566 567 /* drop the node in the old tnode free list */ 568 tnode_free_append(oldtnode, inode); 569 570 /* An internal node with two children */ 571 if (inode->bits == 1) { 572 put_child(tn, 2 * i + 1, get_child(inode, 1)); 573 put_child(tn, 2 * i, get_child(inode, 0)); 574 continue; 575 } 576 577 /* We will replace this node 'inode' with two new 578 * ones, 'node0' and 'node1', each with half of the 579 * original children. The two new nodes will have 580 * a position one bit further down the key and this 581 * means that the "significant" part of their keys 582 * (see the discussion near the top of this file) 583 * will differ by one bit, which will be "0" in 584 * node0's key and "1" in node1's key. Since we are 585 * moving the key position by one step, the bit that 586 * we are moving away from - the bit at position 587 * (tn->pos) - is the one that will differ between 588 * node0 and node1. So... we synthesize that bit in the 589 * two new keys. 590 */ 591 node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1); 592 if (!node1) 593 goto nomem; 594 node0 = tnode_new(inode->key, inode->pos, inode->bits - 1); 595 596 tnode_free_append(tn, node1); 597 if (!node0) 598 goto nomem; 599 tnode_free_append(tn, node0); 600 601 /* populate child pointers in new nodes */ 602 for (k = child_length(inode), j = k / 2; j;) { 603 put_child(node1, --j, get_child(inode, --k)); 604 put_child(node0, j, get_child(inode, j)); 605 put_child(node1, --j, get_child(inode, --k)); 606 put_child(node0, j, get_child(inode, j)); 607 } 608 609 /* link new nodes to parent */ 610 NODE_INIT_PARENT(node1, tn); 611 NODE_INIT_PARENT(node0, tn); 612 613 /* link parent to nodes */ 614 put_child(tn, 2 * i + 1, node1); 615 put_child(tn, 2 * i, node0); 616 } 617 618 /* setup the parent pointers into and out of this node */ 619 return replace(t, oldtnode, tn); 620nomem: 621 /* all pointers should be clean so we are done */ 622 tnode_free(tn); 623notnode: 624 return NULL; 625} 626 627static struct key_vector *halve(struct trie *t, 628 struct key_vector *oldtnode) 629{ 630 struct key_vector *tn; 631 unsigned long i; 632 633 pr_debug("In halve\n"); 634 635 tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1); 636 if (!tn) 637 goto notnode; 638 639 /* prepare oldtnode to be freed */ 640 tnode_free_init(oldtnode); 641 642 /* Assemble all of the pointers in our cluster, in this case that 643 * represents all of the pointers out of our allocated nodes that 644 * point to existing tnodes and the links between our allocated 645 * nodes. 646 */ 647 for (i = child_length(oldtnode); i;) { 648 struct key_vector *node1 = get_child(oldtnode, --i); 649 struct key_vector *node0 = get_child(oldtnode, --i); 650 struct key_vector *inode; 651 652 /* At least one of the children is empty */ 653 if (!node1 || !node0) { 654 put_child(tn, i / 2, node1 ? : node0); 655 continue; 656 } 657 658 /* Two nonempty children */ 659 inode = tnode_new(node0->key, oldtnode->pos, 1); 660 if (!inode) 661 goto nomem; 662 tnode_free_append(tn, inode); 663 664 /* initialize pointers out of node */ 665 put_child(inode, 1, node1); 666 put_child(inode, 0, node0); 667 NODE_INIT_PARENT(inode, tn); 668 669 /* link parent to node */ 670 put_child(tn, i / 2, inode); 671 } 672 673 /* setup the parent pointers into and out of this node */ 674 return replace(t, oldtnode, tn); 675nomem: 676 /* all pointers should be clean so we are done */ 677 tnode_free(tn); 678notnode: 679 return NULL; 680} 681 682static struct key_vector *collapse(struct trie *t, 683 struct key_vector *oldtnode) 684{ 685 struct key_vector *n, *tp; 686 unsigned long i; 687 688 /* scan the tnode looking for that one child that might still exist */ 689 for (n = NULL, i = child_length(oldtnode); !n && i;) 690 n = get_child(oldtnode, --i); 691 692 /* compress one level */ 693 tp = node_parent(oldtnode); 694 put_child_root(tp, oldtnode->key, n); 695 node_set_parent(n, tp); 696 697 /* drop dead node */ 698 node_free(oldtnode); 699 700 return tp; 701} 702 703static unsigned char update_suffix(struct key_vector *tn) 704{ 705 unsigned char slen = tn->pos; 706 unsigned long stride, i; 707 unsigned char slen_max; 708 709 /* only vector 0 can have a suffix length greater than or equal to 710 * tn->pos + tn->bits, the second highest node will have a suffix 711 * length at most of tn->pos + tn->bits - 1 712 */ 713 slen_max = min_t(unsigned char, tn->pos + tn->bits - 1, tn->slen); 714 715 /* search though the list of children looking for nodes that might 716 * have a suffix greater than the one we currently have. This is 717 * why we start with a stride of 2 since a stride of 1 would 718 * represent the nodes with suffix length equal to tn->pos 719 */ 720 for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) { 721 struct key_vector *n = get_child(tn, i); 722 723 if (!n || (n->slen <= slen)) 724 continue; 725 726 /* update stride and slen based on new value */ 727 stride <<= (n->slen - slen); 728 slen = n->slen; 729 i &= ~(stride - 1); 730 731 /* stop searching if we have hit the maximum possible value */ 732 if (slen >= slen_max) 733 break; 734 } 735 736 tn->slen = slen; 737 738 return slen; 739} 740 741/* From "Implementing a dynamic compressed trie" by Stefan Nilsson of 742 * the Helsinki University of Technology and Matti Tikkanen of Nokia 743 * Telecommunications, page 6: 744 * "A node is doubled if the ratio of non-empty children to all 745 * children in the *doubled* node is at least 'high'." 746 * 747 * 'high' in this instance is the variable 'inflate_threshold'. It 748 * is expressed as a percentage, so we multiply it with 749 * child_length() and instead of multiplying by 2 (since the 750 * child array will be doubled by inflate()) and multiplying 751 * the left-hand side by 100 (to handle the percentage thing) we 752 * multiply the left-hand side by 50. 753 * 754 * The left-hand side may look a bit weird: child_length(tn) 755 * - tn->empty_children is of course the number of non-null children 756 * in the current node. tn->full_children is the number of "full" 757 * children, that is non-null tnodes with a skip value of 0. 758 * All of those will be doubled in the resulting inflated tnode, so 759 * we just count them one extra time here. 760 * 761 * A clearer way to write this would be: 762 * 763 * to_be_doubled = tn->full_children; 764 * not_to_be_doubled = child_length(tn) - tn->empty_children - 765 * tn->full_children; 766 * 767 * new_child_length = child_length(tn) * 2; 768 * 769 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) / 770 * new_child_length; 771 * if (new_fill_factor >= inflate_threshold) 772 * 773 * ...and so on, tho it would mess up the while () loop. 774 * 775 * anyway, 776 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >= 777 * inflate_threshold 778 * 779 * avoid a division: 780 * 100 * (not_to_be_doubled + 2*to_be_doubled) >= 781 * inflate_threshold * new_child_length 782 * 783 * expand not_to_be_doubled and to_be_doubled, and shorten: 784 * 100 * (child_length(tn) - tn->empty_children + 785 * tn->full_children) >= inflate_threshold * new_child_length 786 * 787 * expand new_child_length: 788 * 100 * (child_length(tn) - tn->empty_children + 789 * tn->full_children) >= 790 * inflate_threshold * child_length(tn) * 2 791 * 792 * shorten again: 793 * 50 * (tn->full_children + child_length(tn) - 794 * tn->empty_children) >= inflate_threshold * 795 * child_length(tn) 796 * 797 */ 798static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn) 799{ 800 unsigned long used = child_length(tn); 801 unsigned long threshold = used; 802 803 /* Keep root node larger */ 804 threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold; 805 used -= tn_info(tn)->empty_children; 806 used += tn_info(tn)->full_children; 807 808 /* if bits == KEYLENGTH then pos = 0, and will fail below */ 809 810 return (used > 1) && tn->pos && ((50 * used) >= threshold); 811} 812 813static inline bool should_halve(struct key_vector *tp, struct key_vector *tn) 814{ 815 unsigned long used = child_length(tn); 816 unsigned long threshold = used; 817 818 /* Keep root node larger */ 819 threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold; 820 used -= tn_info(tn)->empty_children; 821 822 /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */ 823 824 return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold); 825} 826 827static inline bool should_collapse(struct key_vector *tn) 828{ 829 unsigned long used = child_length(tn); 830 831 used -= tn_info(tn)->empty_children; 832 833 /* account for bits == KEYLENGTH case */ 834 if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children) 835 used -= KEY_MAX; 836 837 /* One child or none, time to drop us from the trie */ 838 return used < 2; 839} 840 841#define MAX_WORK 10 842static struct key_vector *resize(struct trie *t, struct key_vector *tn) 843{ 844#ifdef CONFIG_IP_FIB_TRIE_STATS 845 struct trie_use_stats __percpu *stats = t->stats; 846#endif 847 struct key_vector *tp = node_parent(tn); 848 unsigned long cindex = get_index(tn->key, tp); 849 int max_work = MAX_WORK; 850 851 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n", 852 tn, inflate_threshold, halve_threshold); 853 854 /* track the tnode via the pointer from the parent instead of 855 * doing it ourselves. This way we can let RCU fully do its 856 * thing without us interfering 857 */ 858 BUG_ON(tn != get_child(tp, cindex)); 859 860 /* Double as long as the resulting node has a number of 861 * nonempty nodes that are above the threshold. 862 */ 863 while (should_inflate(tp, tn) && max_work) { 864 tp = inflate(t, tn); 865 if (!tp) { 866#ifdef CONFIG_IP_FIB_TRIE_STATS 867 this_cpu_inc(stats->resize_node_skipped); 868#endif 869 break; 870 } 871 872 max_work--; 873 tn = get_child(tp, cindex); 874 } 875 876 /* update parent in case inflate failed */ 877 tp = node_parent(tn); 878 879 /* Return if at least one inflate is run */ 880 if (max_work != MAX_WORK) 881 return tp; 882 883 /* Halve as long as the number of empty children in this 884 * node is above threshold. 885 */ 886 while (should_halve(tp, tn) && max_work) { 887 tp = halve(t, tn); 888 if (!tp) { 889#ifdef CONFIG_IP_FIB_TRIE_STATS 890 this_cpu_inc(stats->resize_node_skipped); 891#endif 892 break; 893 } 894 895 max_work--; 896 tn = get_child(tp, cindex); 897 } 898 899 /* Only one child remains */ 900 if (should_collapse(tn)) 901 return collapse(t, tn); 902 903 /* update parent in case halve failed */ 904 return node_parent(tn); 905} 906 907static void node_pull_suffix(struct key_vector *tn, unsigned char slen) 908{ 909 unsigned char node_slen = tn->slen; 910 911 while ((node_slen > tn->pos) && (node_slen > slen)) { 912 slen = update_suffix(tn); 913 if (node_slen == slen) 914 break; 915 916 tn = node_parent(tn); 917 node_slen = tn->slen; 918 } 919} 920 921static void node_push_suffix(struct key_vector *tn, unsigned char slen) 922{ 923 while (tn->slen < slen) { 924 tn->slen = slen; 925 tn = node_parent(tn); 926 } 927} 928 929/* rcu_read_lock needs to be hold by caller from readside */ 930static struct key_vector *fib_find_node(struct trie *t, 931 struct key_vector **tp, u32 key) 932{ 933 struct key_vector *pn, *n = t->kv; 934 unsigned long index = 0; 935 936 do { 937 pn = n; 938 n = get_child_rcu(n, index); 939 940 if (!n) 941 break; 942 943 index = get_cindex(key, n); 944 945 /* This bit of code is a bit tricky but it combines multiple 946 * checks into a single check. The prefix consists of the 947 * prefix plus zeros for the bits in the cindex. The index 948 * is the difference between the key and this value. From 949 * this we can actually derive several pieces of data. 950 * if (index >= (1ul << bits)) 951 * we have a mismatch in skip bits and failed 952 * else 953 * we know the value is cindex 954 * 955 * This check is safe even if bits == KEYLENGTH due to the 956 * fact that we can only allocate a node with 32 bits if a 957 * long is greater than 32 bits. 958 */ 959 if (index >= (1ul << n->bits)) { 960 n = NULL; 961 break; 962 } 963 964 /* keep searching until we find a perfect match leaf or NULL */ 965 } while (IS_TNODE(n)); 966 967 *tp = pn; 968 969 return n; 970} 971 972/* Return the first fib alias matching DSCP with 973 * priority less than or equal to PRIO. 974 * If 'find_first' is set, return the first matching 975 * fib alias, regardless of DSCP and priority. 976 */ 977static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen, 978 dscp_t dscp, u32 prio, u32 tb_id, 979 bool find_first) 980{ 981 struct fib_alias *fa; 982 983 if (!fah) 984 return NULL; 985 986 hlist_for_each_entry(fa, fah, fa_list) { 987 /* Avoid Sparse warning when using dscp_t in inequalities */ 988 u8 __fa_dscp = inet_dscp_to_dsfield(fa->fa_dscp); 989 u8 __dscp = inet_dscp_to_dsfield(dscp); 990 991 if (fa->fa_slen < slen) 992 continue; 993 if (fa->fa_slen != slen) 994 break; 995 if (fa->tb_id > tb_id) 996 continue; 997 if (fa->tb_id != tb_id) 998 break; 999 if (find_first) 1000 return fa; 1001 if (__fa_dscp > __dscp) 1002 continue; 1003 if (fa->fa_info->fib_priority >= prio || __fa_dscp < __dscp) 1004 return fa; 1005 } 1006 1007 return NULL; 1008} 1009 1010static struct fib_alias * 1011fib_find_matching_alias(struct net *net, const struct fib_rt_info *fri) 1012{ 1013 u8 slen = KEYLENGTH - fri->dst_len; 1014 struct key_vector *l, *tp; 1015 struct fib_table *tb; 1016 struct fib_alias *fa; 1017 struct trie *t; 1018 1019 tb = fib_get_table(net, fri->tb_id); 1020 if (!tb) 1021 return NULL; 1022 1023 t = (struct trie *)tb->tb_data; 1024 l = fib_find_node(t, &tp, be32_to_cpu(fri->dst)); 1025 if (!l) 1026 return NULL; 1027 1028 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 1029 if (fa->fa_slen == slen && fa->tb_id == fri->tb_id && 1030 fa->fa_dscp == fri->dscp && fa->fa_info == fri->fi && 1031 fa->fa_type == fri->type) 1032 return fa; 1033 } 1034 1035 return NULL; 1036} 1037 1038void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri) 1039{ 1040 u8 fib_notify_on_flag_change; 1041 struct fib_alias *fa_match; 1042 struct sk_buff *skb; 1043 int err; 1044 1045 rcu_read_lock(); 1046 1047 fa_match = fib_find_matching_alias(net, fri); 1048 if (!fa_match) 1049 goto out; 1050 1051 /* These are paired with the WRITE_ONCE() happening in this function. 1052 * The reason is that we are only protected by RCU at this point. 1053 */ 1054 if (READ_ONCE(fa_match->offload) == fri->offload && 1055 READ_ONCE(fa_match->trap) == fri->trap && 1056 READ_ONCE(fa_match->offload_failed) == fri->offload_failed) 1057 goto out; 1058 1059 WRITE_ONCE(fa_match->offload, fri->offload); 1060 WRITE_ONCE(fa_match->trap, fri->trap); 1061 1062 fib_notify_on_flag_change = READ_ONCE(net->ipv4.sysctl_fib_notify_on_flag_change); 1063 1064 /* 2 means send notifications only if offload_failed was changed. */ 1065 if (fib_notify_on_flag_change == 2 && 1066 READ_ONCE(fa_match->offload_failed) == fri->offload_failed) 1067 goto out; 1068 1069 WRITE_ONCE(fa_match->offload_failed, fri->offload_failed); 1070 1071 if (!fib_notify_on_flag_change) 1072 goto out; 1073 1074 skb = nlmsg_new(fib_nlmsg_size(fa_match->fa_info), GFP_ATOMIC); 1075 if (!skb) { 1076 err = -ENOBUFS; 1077 goto errout; 1078 } 1079 1080 err = fib_dump_info(skb, 0, 0, RTM_NEWROUTE, fri, 0); 1081 if (err < 0) { 1082 /* -EMSGSIZE implies BUG in fib_nlmsg_size() */ 1083 WARN_ON(err == -EMSGSIZE); 1084 kfree_skb(skb); 1085 goto errout; 1086 } 1087 1088 rtnl_notify(skb, net, 0, RTNLGRP_IPV4_ROUTE, NULL, GFP_ATOMIC); 1089 goto out; 1090 1091errout: 1092 rtnl_set_sk_err(net, RTNLGRP_IPV4_ROUTE, err); 1093out: 1094 rcu_read_unlock(); 1095} 1096EXPORT_SYMBOL_GPL(fib_alias_hw_flags_set); 1097 1098static void trie_rebalance(struct trie *t, struct key_vector *tn) 1099{ 1100 while (!IS_TRIE(tn)) 1101 tn = resize(t, tn); 1102} 1103 1104static int fib_insert_node(struct trie *t, struct key_vector *tp, 1105 struct fib_alias *new, t_key key) 1106{ 1107 struct key_vector *n, *l; 1108 1109 l = leaf_new(key, new); 1110 if (!l) 1111 goto noleaf; 1112 1113 /* retrieve child from parent node */ 1114 n = get_child(tp, get_index(key, tp)); 1115 1116 /* Case 2: n is a LEAF or a TNODE and the key doesn't match. 1117 * 1118 * Add a new tnode here 1119 * first tnode need some special handling 1120 * leaves us in position for handling as case 3 1121 */ 1122 if (n) { 1123 struct key_vector *tn; 1124 1125 tn = tnode_new(key, __fls(key ^ n->key), 1); 1126 if (!tn) 1127 goto notnode; 1128 1129 /* initialize routes out of node */ 1130 NODE_INIT_PARENT(tn, tp); 1131 put_child(tn, get_index(key, tn) ^ 1, n); 1132 1133 /* start adding routes into the node */ 1134 put_child_root(tp, key, tn); 1135 node_set_parent(n, tn); 1136 1137 /* parent now has a NULL spot where the leaf can go */ 1138 tp = tn; 1139 } 1140 1141 /* Case 3: n is NULL, and will just insert a new leaf */ 1142 node_push_suffix(tp, new->fa_slen); 1143 NODE_INIT_PARENT(l, tp); 1144 put_child_root(tp, key, l); 1145 trie_rebalance(t, tp); 1146 1147 return 0; 1148notnode: 1149 node_free(l); 1150noleaf: 1151 return -ENOMEM; 1152} 1153 1154static int fib_insert_alias(struct trie *t, struct key_vector *tp, 1155 struct key_vector *l, struct fib_alias *new, 1156 struct fib_alias *fa, t_key key) 1157{ 1158 if (!l) 1159 return fib_insert_node(t, tp, new, key); 1160 1161 if (fa) { 1162 hlist_add_before_rcu(&new->fa_list, &fa->fa_list); 1163 } else { 1164 struct fib_alias *last; 1165 1166 hlist_for_each_entry(last, &l->leaf, fa_list) { 1167 if (new->fa_slen < last->fa_slen) 1168 break; 1169 if ((new->fa_slen == last->fa_slen) && 1170 (new->tb_id > last->tb_id)) 1171 break; 1172 fa = last; 1173 } 1174 1175 if (fa) 1176 hlist_add_behind_rcu(&new->fa_list, &fa->fa_list); 1177 else 1178 hlist_add_head_rcu(&new->fa_list, &l->leaf); 1179 } 1180 1181 /* if we added to the tail node then we need to update slen */ 1182 if (l->slen < new->fa_slen) { 1183 l->slen = new->fa_slen; 1184 node_push_suffix(tp, new->fa_slen); 1185 } 1186 1187 return 0; 1188} 1189 1190static void fib_remove_alias(struct trie *t, struct key_vector *tp, 1191 struct key_vector *l, struct fib_alias *old); 1192 1193/* Caller must hold RTNL. */ 1194int fib_table_insert(struct net *net, struct fib_table *tb, 1195 struct fib_config *cfg, struct netlink_ext_ack *extack) 1196{ 1197 struct trie *t = (struct trie *)tb->tb_data; 1198 struct fib_alias *fa, *new_fa; 1199 struct key_vector *l, *tp; 1200 u16 nlflags = NLM_F_EXCL; 1201 struct fib_info *fi; 1202 u8 plen = cfg->fc_dst_len; 1203 u8 slen = KEYLENGTH - plen; 1204 dscp_t dscp; 1205 u32 key; 1206 int err; 1207 1208 key = ntohl(cfg->fc_dst); 1209 1210 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen); 1211 1212 fi = fib_create_info(cfg, extack); 1213 if (IS_ERR(fi)) { 1214 err = PTR_ERR(fi); 1215 goto err; 1216 } 1217 1218 dscp = cfg->fc_dscp; 1219 l = fib_find_node(t, &tp, key); 1220 fa = l ? fib_find_alias(&l->leaf, slen, dscp, fi->fib_priority, 1221 tb->tb_id, false) : NULL; 1222 1223 /* Now fa, if non-NULL, points to the first fib alias 1224 * with the same keys [prefix,dscp,priority], if such key already 1225 * exists or to the node before which we will insert new one. 1226 * 1227 * If fa is NULL, we will need to allocate a new one and 1228 * insert to the tail of the section matching the suffix length 1229 * of the new alias. 1230 */ 1231 1232 if (fa && fa->fa_dscp == dscp && 1233 fa->fa_info->fib_priority == fi->fib_priority) { 1234 struct fib_alias *fa_first, *fa_match; 1235 1236 err = -EEXIST; 1237 if (cfg->fc_nlflags & NLM_F_EXCL) 1238 goto out; 1239 1240 nlflags &= ~NLM_F_EXCL; 1241 1242 /* We have 2 goals: 1243 * 1. Find exact match for type, scope, fib_info to avoid 1244 * duplicate routes 1245 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it 1246 */ 1247 fa_match = NULL; 1248 fa_first = fa; 1249 hlist_for_each_entry_from(fa, fa_list) { 1250 if ((fa->fa_slen != slen) || 1251 (fa->tb_id != tb->tb_id) || 1252 (fa->fa_dscp != dscp)) 1253 break; 1254 if (fa->fa_info->fib_priority != fi->fib_priority) 1255 break; 1256 if (fa->fa_type == cfg->fc_type && 1257 fa->fa_info == fi) { 1258 fa_match = fa; 1259 break; 1260 } 1261 } 1262 1263 if (cfg->fc_nlflags & NLM_F_REPLACE) { 1264 struct fib_info *fi_drop; 1265 u8 state; 1266 1267 nlflags |= NLM_F_REPLACE; 1268 fa = fa_first; 1269 if (fa_match) { 1270 if (fa == fa_match) 1271 err = 0; 1272 goto out; 1273 } 1274 err = -ENOBUFS; 1275 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1276 if (!new_fa) 1277 goto out; 1278 1279 fi_drop = fa->fa_info; 1280 new_fa->fa_dscp = fa->fa_dscp; 1281 new_fa->fa_info = fi; 1282 new_fa->fa_type = cfg->fc_type; 1283 state = READ_ONCE(fa->fa_state); 1284 new_fa->fa_state = state & ~FA_S_ACCESSED; 1285 new_fa->fa_slen = fa->fa_slen; 1286 new_fa->tb_id = tb->tb_id; 1287 new_fa->fa_default = -1; 1288 new_fa->offload = 0; 1289 new_fa->trap = 0; 1290 new_fa->offload_failed = 0; 1291 1292 hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list); 1293 1294 if (fib_find_alias(&l->leaf, fa->fa_slen, 0, 0, 1295 tb->tb_id, true) == new_fa) { 1296 enum fib_event_type fib_event; 1297 1298 fib_event = FIB_EVENT_ENTRY_REPLACE; 1299 err = call_fib_entry_notifiers(net, fib_event, 1300 key, plen, 1301 new_fa, extack); 1302 if (err) { 1303 hlist_replace_rcu(&new_fa->fa_list, 1304 &fa->fa_list); 1305 goto out_free_new_fa; 1306 } 1307 } 1308 1309 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, 1310 tb->tb_id, &cfg->fc_nlinfo, nlflags); 1311 1312 alias_free_mem_rcu(fa); 1313 1314 fib_release_info(fi_drop); 1315 if (state & FA_S_ACCESSED) 1316 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1317 1318 goto succeeded; 1319 } 1320 /* Error if we find a perfect match which 1321 * uses the same scope, type, and nexthop 1322 * information. 1323 */ 1324 if (fa_match) 1325 goto out; 1326 1327 if (cfg->fc_nlflags & NLM_F_APPEND) 1328 nlflags |= NLM_F_APPEND; 1329 else 1330 fa = fa_first; 1331 } 1332 err = -ENOENT; 1333 if (!(cfg->fc_nlflags & NLM_F_CREATE)) 1334 goto out; 1335 1336 nlflags |= NLM_F_CREATE; 1337 err = -ENOBUFS; 1338 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1339 if (!new_fa) 1340 goto out; 1341 1342 new_fa->fa_info = fi; 1343 new_fa->fa_dscp = dscp; 1344 new_fa->fa_type = cfg->fc_type; 1345 new_fa->fa_state = 0; 1346 new_fa->fa_slen = slen; 1347 new_fa->tb_id = tb->tb_id; 1348 new_fa->fa_default = -1; 1349 new_fa->offload = 0; 1350 new_fa->trap = 0; 1351 new_fa->offload_failed = 0; 1352 1353 /* Insert new entry to the list. */ 1354 err = fib_insert_alias(t, tp, l, new_fa, fa, key); 1355 if (err) 1356 goto out_free_new_fa; 1357 1358 /* The alias was already inserted, so the node must exist. */ 1359 l = l ? l : fib_find_node(t, &tp, key); 1360 if (WARN_ON_ONCE(!l)) { 1361 err = -ENOENT; 1362 goto out_free_new_fa; 1363 } 1364 1365 if (fib_find_alias(&l->leaf, new_fa->fa_slen, 0, 0, tb->tb_id, true) == 1366 new_fa) { 1367 enum fib_event_type fib_event; 1368 1369 fib_event = FIB_EVENT_ENTRY_REPLACE; 1370 err = call_fib_entry_notifiers(net, fib_event, key, plen, 1371 new_fa, extack); 1372 if (err) 1373 goto out_remove_new_fa; 1374 } 1375 1376 if (!plen) 1377 tb->tb_num_default++; 1378 1379 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1380 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id, 1381 &cfg->fc_nlinfo, nlflags); 1382succeeded: 1383 return 0; 1384 1385out_remove_new_fa: 1386 fib_remove_alias(t, tp, l, new_fa); 1387out_free_new_fa: 1388 kmem_cache_free(fn_alias_kmem, new_fa); 1389out: 1390 fib_release_info(fi); 1391err: 1392 return err; 1393} 1394 1395static inline t_key prefix_mismatch(t_key key, struct key_vector *n) 1396{ 1397 t_key prefix = n->key; 1398 1399 return (key ^ prefix) & (prefix | -prefix); 1400} 1401 1402bool fib_lookup_good_nhc(const struct fib_nh_common *nhc, int fib_flags, 1403 const struct flowi4 *flp) 1404{ 1405 if (nhc->nhc_flags & RTNH_F_DEAD) 1406 return false; 1407 1408 if (ip_ignore_linkdown(nhc->nhc_dev) && 1409 nhc->nhc_flags & RTNH_F_LINKDOWN && 1410 !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE)) 1411 return false; 1412 1413 if (flp->flowi4_oif && flp->flowi4_oif != nhc->nhc_oif) 1414 return false; 1415 1416 return true; 1417} 1418 1419/* should be called with rcu_read_lock */ 1420int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 1421 struct fib_result *res, int fib_flags) 1422{ 1423 struct trie *t = (struct trie *) tb->tb_data; 1424#ifdef CONFIG_IP_FIB_TRIE_STATS 1425 struct trie_use_stats __percpu *stats = t->stats; 1426#endif 1427 const t_key key = ntohl(flp->daddr); 1428 struct key_vector *n, *pn; 1429 struct fib_alias *fa; 1430 unsigned long index; 1431 t_key cindex; 1432 1433 pn = t->kv; 1434 cindex = 0; 1435 1436 n = get_child_rcu(pn, cindex); 1437 if (!n) { 1438 trace_fib_table_lookup(tb->tb_id, flp, NULL, -EAGAIN); 1439 return -EAGAIN; 1440 } 1441 1442#ifdef CONFIG_IP_FIB_TRIE_STATS 1443 this_cpu_inc(stats->gets); 1444#endif 1445 1446 /* Step 1: Travel to the longest prefix match in the trie */ 1447 for (;;) { 1448 index = get_cindex(key, n); 1449 1450 /* This bit of code is a bit tricky but it combines multiple 1451 * checks into a single check. The prefix consists of the 1452 * prefix plus zeros for the "bits" in the prefix. The index 1453 * is the difference between the key and this value. From 1454 * this we can actually derive several pieces of data. 1455 * if (index >= (1ul << bits)) 1456 * we have a mismatch in skip bits and failed 1457 * else 1458 * we know the value is cindex 1459 * 1460 * This check is safe even if bits == KEYLENGTH due to the 1461 * fact that we can only allocate a node with 32 bits if a 1462 * long is greater than 32 bits. 1463 */ 1464 if (index >= (1ul << n->bits)) 1465 break; 1466 1467 /* we have found a leaf. Prefixes have already been compared */ 1468 if (IS_LEAF(n)) 1469 goto found; 1470 1471 /* only record pn and cindex if we are going to be chopping 1472 * bits later. Otherwise we are just wasting cycles. 1473 */ 1474 if (n->slen > n->pos) { 1475 pn = n; 1476 cindex = index; 1477 } 1478 1479 n = get_child_rcu(n, index); 1480 if (unlikely(!n)) 1481 goto backtrace; 1482 } 1483 1484 /* Step 2: Sort out leaves and begin backtracing for longest prefix */ 1485 for (;;) { 1486 /* record the pointer where our next node pointer is stored */ 1487 struct key_vector __rcu **cptr = n->tnode; 1488 1489 /* This test verifies that none of the bits that differ 1490 * between the key and the prefix exist in the region of 1491 * the lsb and higher in the prefix. 1492 */ 1493 if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos)) 1494 goto backtrace; 1495 1496 /* exit out and process leaf */ 1497 if (unlikely(IS_LEAF(n))) 1498 break; 1499 1500 /* Don't bother recording parent info. Since we are in 1501 * prefix match mode we will have to come back to wherever 1502 * we started this traversal anyway 1503 */ 1504 1505 while ((n = rcu_dereference(*cptr)) == NULL) { 1506backtrace: 1507#ifdef CONFIG_IP_FIB_TRIE_STATS 1508 if (!n) 1509 this_cpu_inc(stats->null_node_hit); 1510#endif 1511 /* If we are at cindex 0 there are no more bits for 1512 * us to strip at this level so we must ascend back 1513 * up one level to see if there are any more bits to 1514 * be stripped there. 1515 */ 1516 while (!cindex) { 1517 t_key pkey = pn->key; 1518 1519 /* If we don't have a parent then there is 1520 * nothing for us to do as we do not have any 1521 * further nodes to parse. 1522 */ 1523 if (IS_TRIE(pn)) { 1524 trace_fib_table_lookup(tb->tb_id, flp, 1525 NULL, -EAGAIN); 1526 return -EAGAIN; 1527 } 1528#ifdef CONFIG_IP_FIB_TRIE_STATS 1529 this_cpu_inc(stats->backtrack); 1530#endif 1531 /* Get Child's index */ 1532 pn = node_parent_rcu(pn); 1533 cindex = get_index(pkey, pn); 1534 } 1535 1536 /* strip the least significant bit from the cindex */ 1537 cindex &= cindex - 1; 1538 1539 /* grab pointer for next child node */ 1540 cptr = &pn->tnode[cindex]; 1541 } 1542 } 1543 1544found: 1545 /* this line carries forward the xor from earlier in the function */ 1546 index = key ^ n->key; 1547 1548 /* Step 3: Process the leaf, if that fails fall back to backtracing */ 1549 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) { 1550 struct fib_info *fi = fa->fa_info; 1551 struct fib_nh_common *nhc; 1552 int nhsel, err; 1553 1554 if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) { 1555 if (index >= (1ul << fa->fa_slen)) 1556 continue; 1557 } 1558 if (fa->fa_dscp && !fib_dscp_masked_match(fa->fa_dscp, flp)) 1559 continue; 1560 /* Paired with WRITE_ONCE() in fib_release_info() */ 1561 if (READ_ONCE(fi->fib_dead)) 1562 continue; 1563 if (fa->fa_info->fib_scope < flp->flowi4_scope) 1564 continue; 1565 fib_alias_accessed(fa); 1566 err = fib_props[fa->fa_type].error; 1567 if (unlikely(err < 0)) { 1568out_reject: 1569#ifdef CONFIG_IP_FIB_TRIE_STATS 1570 this_cpu_inc(stats->semantic_match_passed); 1571#endif 1572 trace_fib_table_lookup(tb->tb_id, flp, NULL, err); 1573 return err; 1574 } 1575 if (fi->fib_flags & RTNH_F_DEAD) 1576 continue; 1577 1578 if (unlikely(fi->nh)) { 1579 if (nexthop_is_blackhole(fi->nh)) { 1580 err = fib_props[RTN_BLACKHOLE].error; 1581 goto out_reject; 1582 } 1583 1584 nhc = nexthop_get_nhc_lookup(fi->nh, fib_flags, flp, 1585 &nhsel); 1586 if (nhc) 1587 goto set_result; 1588 goto miss; 1589 } 1590 1591 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 1592 nhc = fib_info_nhc(fi, nhsel); 1593 1594 if (!fib_lookup_good_nhc(nhc, fib_flags, flp)) 1595 continue; 1596set_result: 1597 if (!(fib_flags & FIB_LOOKUP_NOREF)) 1598 refcount_inc(&fi->fib_clntref); 1599 1600 res->prefix = htonl(n->key); 1601 res->prefixlen = KEYLENGTH - fa->fa_slen; 1602 res->nh_sel = nhsel; 1603 res->nhc = nhc; 1604 res->type = fa->fa_type; 1605 res->scope = fi->fib_scope; 1606 res->dscp = fa->fa_dscp; 1607 res->fi = fi; 1608 res->table = tb; 1609 res->fa_head = &n->leaf; 1610#ifdef CONFIG_IP_FIB_TRIE_STATS 1611 this_cpu_inc(stats->semantic_match_passed); 1612#endif 1613 trace_fib_table_lookup(tb->tb_id, flp, nhc, err); 1614 1615 return err; 1616 } 1617 } 1618miss: 1619#ifdef CONFIG_IP_FIB_TRIE_STATS 1620 this_cpu_inc(stats->semantic_match_miss); 1621#endif 1622 goto backtrace; 1623} 1624EXPORT_SYMBOL_GPL(fib_table_lookup); 1625 1626static void fib_remove_alias(struct trie *t, struct key_vector *tp, 1627 struct key_vector *l, struct fib_alias *old) 1628{ 1629 /* record the location of the previous list_info entry */ 1630 struct hlist_node **pprev = old->fa_list.pprev; 1631 struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next); 1632 1633 /* remove the fib_alias from the list */ 1634 hlist_del_rcu(&old->fa_list); 1635 1636 /* if we emptied the list this leaf will be freed and we can sort 1637 * out parent suffix lengths as a part of trie_rebalance 1638 */ 1639 if (hlist_empty(&l->leaf)) { 1640 if (tp->slen == l->slen) 1641 node_pull_suffix(tp, tp->pos); 1642 put_child_root(tp, l->key, NULL); 1643 node_free(l); 1644 trie_rebalance(t, tp); 1645 return; 1646 } 1647 1648 /* only access fa if it is pointing at the last valid hlist_node */ 1649 if (*pprev) 1650 return; 1651 1652 /* update the trie with the latest suffix length */ 1653 l->slen = fa->fa_slen; 1654 node_pull_suffix(tp, fa->fa_slen); 1655} 1656 1657static void fib_notify_alias_delete(struct net *net, u32 key, 1658 struct hlist_head *fah, 1659 struct fib_alias *fa_to_delete, 1660 struct netlink_ext_ack *extack) 1661{ 1662 struct fib_alias *fa_next, *fa_to_notify; 1663 u32 tb_id = fa_to_delete->tb_id; 1664 u8 slen = fa_to_delete->fa_slen; 1665 enum fib_event_type fib_event; 1666 1667 /* Do not notify if we do not care about the route. */ 1668 if (fib_find_alias(fah, slen, 0, 0, tb_id, true) != fa_to_delete) 1669 return; 1670 1671 /* Determine if the route should be replaced by the next route in the 1672 * list. 1673 */ 1674 fa_next = hlist_entry_safe(fa_to_delete->fa_list.next, 1675 struct fib_alias, fa_list); 1676 if (fa_next && fa_next->fa_slen == slen && fa_next->tb_id == tb_id) { 1677 fib_event = FIB_EVENT_ENTRY_REPLACE; 1678 fa_to_notify = fa_next; 1679 } else { 1680 fib_event = FIB_EVENT_ENTRY_DEL; 1681 fa_to_notify = fa_to_delete; 1682 } 1683 call_fib_entry_notifiers(net, fib_event, key, KEYLENGTH - slen, 1684 fa_to_notify, extack); 1685} 1686 1687/* Caller must hold RTNL. */ 1688int fib_table_delete(struct net *net, struct fib_table *tb, 1689 struct fib_config *cfg, struct netlink_ext_ack *extack) 1690{ 1691 struct trie *t = (struct trie *) tb->tb_data; 1692 struct fib_alias *fa, *fa_to_delete; 1693 struct key_vector *l, *tp; 1694 u8 plen = cfg->fc_dst_len; 1695 u8 slen = KEYLENGTH - plen; 1696 dscp_t dscp; 1697 u32 key; 1698 1699 key = ntohl(cfg->fc_dst); 1700 1701 l = fib_find_node(t, &tp, key); 1702 if (!l) 1703 return -ESRCH; 1704 1705 dscp = cfg->fc_dscp; 1706 fa = fib_find_alias(&l->leaf, slen, dscp, 0, tb->tb_id, false); 1707 if (!fa) 1708 return -ESRCH; 1709 1710 pr_debug("Deleting %08x/%d dsfield=0x%02x t=%p\n", key, plen, 1711 inet_dscp_to_dsfield(dscp), t); 1712 1713 fa_to_delete = NULL; 1714 hlist_for_each_entry_from(fa, fa_list) { 1715 struct fib_info *fi = fa->fa_info; 1716 1717 if ((fa->fa_slen != slen) || 1718 (fa->tb_id != tb->tb_id) || 1719 (fa->fa_dscp != dscp)) 1720 break; 1721 1722 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) && 1723 (cfg->fc_scope == RT_SCOPE_NOWHERE || 1724 fa->fa_info->fib_scope == cfg->fc_scope) && 1725 (!cfg->fc_prefsrc || 1726 fi->fib_prefsrc == cfg->fc_prefsrc) && 1727 (!cfg->fc_protocol || 1728 fi->fib_protocol == cfg->fc_protocol) && 1729 fib_nh_match(net, cfg, fi, extack) == 0 && 1730 fib_metrics_match(cfg, fi)) { 1731 fa_to_delete = fa; 1732 break; 1733 } 1734 } 1735 1736 if (!fa_to_delete) 1737 return -ESRCH; 1738 1739 fib_notify_alias_delete(net, key, &l->leaf, fa_to_delete, extack); 1740 rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id, 1741 &cfg->fc_nlinfo, 0); 1742 1743 if (!plen) 1744 tb->tb_num_default--; 1745 1746 fib_remove_alias(t, tp, l, fa_to_delete); 1747 1748 if (READ_ONCE(fa_to_delete->fa_state) & FA_S_ACCESSED) 1749 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1750 1751 fib_release_info(fa_to_delete->fa_info); 1752 alias_free_mem_rcu(fa_to_delete); 1753 return 0; 1754} 1755 1756/* Scan for the next leaf starting at the provided key value */ 1757static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key) 1758{ 1759 struct key_vector *pn, *n = *tn; 1760 unsigned long cindex; 1761 1762 /* this loop is meant to try and find the key in the trie */ 1763 do { 1764 /* record parent and next child index */ 1765 pn = n; 1766 cindex = (key > pn->key) ? get_index(key, pn) : 0; 1767 1768 if (cindex >> pn->bits) 1769 break; 1770 1771 /* descend into the next child */ 1772 n = get_child_rcu(pn, cindex++); 1773 if (!n) 1774 break; 1775 1776 /* guarantee forward progress on the keys */ 1777 if (IS_LEAF(n) && (n->key >= key)) 1778 goto found; 1779 } while (IS_TNODE(n)); 1780 1781 /* this loop will search for the next leaf with a greater key */ 1782 while (!IS_TRIE(pn)) { 1783 /* if we exhausted the parent node we will need to climb */ 1784 if (cindex >= (1ul << pn->bits)) { 1785 t_key pkey = pn->key; 1786 1787 pn = node_parent_rcu(pn); 1788 cindex = get_index(pkey, pn) + 1; 1789 continue; 1790 } 1791 1792 /* grab the next available node */ 1793 n = get_child_rcu(pn, cindex++); 1794 if (!n) 1795 continue; 1796 1797 /* no need to compare keys since we bumped the index */ 1798 if (IS_LEAF(n)) 1799 goto found; 1800 1801 /* Rescan start scanning in new node */ 1802 pn = n; 1803 cindex = 0; 1804 } 1805 1806 *tn = pn; 1807 return NULL; /* Root of trie */ 1808found: 1809 /* if we are at the limit for keys just return NULL for the tnode */ 1810 *tn = pn; 1811 return n; 1812} 1813 1814static void fib_trie_free(struct fib_table *tb) 1815{ 1816 struct trie *t = (struct trie *)tb->tb_data; 1817 struct key_vector *pn = t->kv; 1818 unsigned long cindex = 1; 1819 struct hlist_node *tmp; 1820 struct fib_alias *fa; 1821 1822 /* walk trie in reverse order and free everything */ 1823 for (;;) { 1824 struct key_vector *n; 1825 1826 if (!(cindex--)) { 1827 t_key pkey = pn->key; 1828 1829 if (IS_TRIE(pn)) 1830 break; 1831 1832 n = pn; 1833 pn = node_parent(pn); 1834 1835 /* drop emptied tnode */ 1836 put_child_root(pn, n->key, NULL); 1837 node_free(n); 1838 1839 cindex = get_index(pkey, pn); 1840 1841 continue; 1842 } 1843 1844 /* grab the next available node */ 1845 n = get_child(pn, cindex); 1846 if (!n) 1847 continue; 1848 1849 if (IS_TNODE(n)) { 1850 /* record pn and cindex for leaf walking */ 1851 pn = n; 1852 cindex = 1ul << n->bits; 1853 1854 continue; 1855 } 1856 1857 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 1858 hlist_del_rcu(&fa->fa_list); 1859 alias_free_mem_rcu(fa); 1860 } 1861 1862 put_child_root(pn, n->key, NULL); 1863 node_free(n); 1864 } 1865 1866#ifdef CONFIG_IP_FIB_TRIE_STATS 1867 free_percpu(t->stats); 1868#endif 1869 kfree(tb); 1870} 1871 1872struct fib_table *fib_trie_unmerge(struct fib_table *oldtb) 1873{ 1874 struct trie *ot = (struct trie *)oldtb->tb_data; 1875 struct key_vector *l, *tp = ot->kv; 1876 struct fib_table *local_tb; 1877 struct fib_alias *fa; 1878 struct trie *lt; 1879 t_key key = 0; 1880 1881 if (oldtb->tb_data == oldtb->__data) 1882 return oldtb; 1883 1884 local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL); 1885 if (!local_tb) 1886 return NULL; 1887 1888 lt = (struct trie *)local_tb->tb_data; 1889 1890 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 1891 struct key_vector *local_l = NULL, *local_tp; 1892 1893 hlist_for_each_entry(fa, &l->leaf, fa_list) { 1894 struct fib_alias *new_fa; 1895 1896 if (local_tb->tb_id != fa->tb_id) 1897 continue; 1898 1899 /* clone fa for new local table */ 1900 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1901 if (!new_fa) 1902 goto out; 1903 1904 memcpy(new_fa, fa, sizeof(*fa)); 1905 1906 /* insert clone into table */ 1907 if (!local_l) 1908 local_l = fib_find_node(lt, &local_tp, l->key); 1909 1910 if (fib_insert_alias(lt, local_tp, local_l, new_fa, 1911 NULL, l->key)) { 1912 kmem_cache_free(fn_alias_kmem, new_fa); 1913 goto out; 1914 } 1915 } 1916 1917 /* stop loop if key wrapped back to 0 */ 1918 key = l->key + 1; 1919 if (key < l->key) 1920 break; 1921 } 1922 1923 return local_tb; 1924out: 1925 fib_trie_free(local_tb); 1926 1927 return NULL; 1928} 1929 1930/* Caller must hold RTNL */ 1931void fib_table_flush_external(struct fib_table *tb) 1932{ 1933 struct trie *t = (struct trie *)tb->tb_data; 1934 struct key_vector *pn = t->kv; 1935 unsigned long cindex = 1; 1936 struct hlist_node *tmp; 1937 struct fib_alias *fa; 1938 1939 /* walk trie in reverse order */ 1940 for (;;) { 1941 unsigned char slen = 0; 1942 struct key_vector *n; 1943 1944 if (!(cindex--)) { 1945 t_key pkey = pn->key; 1946 1947 /* cannot resize the trie vector */ 1948 if (IS_TRIE(pn)) 1949 break; 1950 1951 /* update the suffix to address pulled leaves */ 1952 if (pn->slen > pn->pos) 1953 update_suffix(pn); 1954 1955 /* resize completed node */ 1956 pn = resize(t, pn); 1957 cindex = get_index(pkey, pn); 1958 1959 continue; 1960 } 1961 1962 /* grab the next available node */ 1963 n = get_child(pn, cindex); 1964 if (!n) 1965 continue; 1966 1967 if (IS_TNODE(n)) { 1968 /* record pn and cindex for leaf walking */ 1969 pn = n; 1970 cindex = 1ul << n->bits; 1971 1972 continue; 1973 } 1974 1975 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 1976 /* if alias was cloned to local then we just 1977 * need to remove the local copy from main 1978 */ 1979 if (tb->tb_id != fa->tb_id) { 1980 hlist_del_rcu(&fa->fa_list); 1981 alias_free_mem_rcu(fa); 1982 continue; 1983 } 1984 1985 /* record local slen */ 1986 slen = fa->fa_slen; 1987 } 1988 1989 /* update leaf slen */ 1990 n->slen = slen; 1991 1992 if (hlist_empty(&n->leaf)) { 1993 put_child_root(pn, n->key, NULL); 1994 node_free(n); 1995 } 1996 } 1997} 1998 1999/* Caller must hold RTNL. */ 2000int fib_table_flush(struct net *net, struct fib_table *tb, bool flush_all) 2001{ 2002 struct trie *t = (struct trie *)tb->tb_data; 2003 struct nl_info info = { .nl_net = net }; 2004 struct key_vector *pn = t->kv; 2005 unsigned long cindex = 1; 2006 struct hlist_node *tmp; 2007 struct fib_alias *fa; 2008 int found = 0; 2009 2010 /* walk trie in reverse order */ 2011 for (;;) { 2012 unsigned char slen = 0; 2013 struct key_vector *n; 2014 2015 if (!(cindex--)) { 2016 t_key pkey = pn->key; 2017 2018 /* cannot resize the trie vector */ 2019 if (IS_TRIE(pn)) 2020 break; 2021 2022 /* update the suffix to address pulled leaves */ 2023 if (pn->slen > pn->pos) 2024 update_suffix(pn); 2025 2026 /* resize completed node */ 2027 pn = resize(t, pn); 2028 cindex = get_index(pkey, pn); 2029 2030 continue; 2031 } 2032 2033 /* grab the next available node */ 2034 n = get_child(pn, cindex); 2035 if (!n) 2036 continue; 2037 2038 if (IS_TNODE(n)) { 2039 /* record pn and cindex for leaf walking */ 2040 pn = n; 2041 cindex = 1ul << n->bits; 2042 2043 continue; 2044 } 2045 2046 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 2047 struct fib_info *fi = fa->fa_info; 2048 2049 if (!fi || tb->tb_id != fa->tb_id || 2050 (!(fi->fib_flags & RTNH_F_DEAD) && 2051 !fib_props[fa->fa_type].error)) { 2052 slen = fa->fa_slen; 2053 continue; 2054 } 2055 2056 /* When not flushing the entire table, skip error 2057 * routes that are not marked for deletion. 2058 */ 2059 if (!flush_all && fib_props[fa->fa_type].error && 2060 !(fi->fib_flags & RTNH_F_DEAD)) { 2061 slen = fa->fa_slen; 2062 continue; 2063 } 2064 2065 fib_notify_alias_delete(net, n->key, &n->leaf, fa, 2066 NULL); 2067 if (fi->pfsrc_removed) 2068 rtmsg_fib(RTM_DELROUTE, htonl(n->key), fa, 2069 KEYLENGTH - fa->fa_slen, tb->tb_id, &info, 0); 2070 hlist_del_rcu(&fa->fa_list); 2071 fib_release_info(fa->fa_info); 2072 alias_free_mem_rcu(fa); 2073 found++; 2074 } 2075 2076 /* update leaf slen */ 2077 n->slen = slen; 2078 2079 if (hlist_empty(&n->leaf)) { 2080 put_child_root(pn, n->key, NULL); 2081 node_free(n); 2082 } 2083 } 2084 2085 pr_debug("trie_flush found=%d\n", found); 2086 return found; 2087} 2088 2089/* derived from fib_trie_free */ 2090static void __fib_info_notify_update(struct net *net, struct fib_table *tb, 2091 struct nl_info *info) 2092{ 2093 struct trie *t = (struct trie *)tb->tb_data; 2094 struct key_vector *pn = t->kv; 2095 unsigned long cindex = 1; 2096 struct fib_alias *fa; 2097 2098 for (;;) { 2099 struct key_vector *n; 2100 2101 if (!(cindex--)) { 2102 t_key pkey = pn->key; 2103 2104 if (IS_TRIE(pn)) 2105 break; 2106 2107 pn = node_parent(pn); 2108 cindex = get_index(pkey, pn); 2109 continue; 2110 } 2111 2112 /* grab the next available node */ 2113 n = get_child(pn, cindex); 2114 if (!n) 2115 continue; 2116 2117 if (IS_TNODE(n)) { 2118 /* record pn and cindex for leaf walking */ 2119 pn = n; 2120 cindex = 1ul << n->bits; 2121 2122 continue; 2123 } 2124 2125 hlist_for_each_entry(fa, &n->leaf, fa_list) { 2126 struct fib_info *fi = fa->fa_info; 2127 2128 if (!fi || !fi->nh_updated || fa->tb_id != tb->tb_id) 2129 continue; 2130 2131 rtmsg_fib(RTM_NEWROUTE, htonl(n->key), fa, 2132 KEYLENGTH - fa->fa_slen, tb->tb_id, 2133 info, NLM_F_REPLACE); 2134 } 2135 } 2136} 2137 2138void fib_info_notify_update(struct net *net, struct nl_info *info) 2139{ 2140 unsigned int h; 2141 2142 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2143 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2144 struct fib_table *tb; 2145 2146 hlist_for_each_entry_rcu(tb, head, tb_hlist, 2147 lockdep_rtnl_is_held()) 2148 __fib_info_notify_update(net, tb, info); 2149 } 2150} 2151 2152static int fib_leaf_notify(struct key_vector *l, struct fib_table *tb, 2153 struct notifier_block *nb, 2154 struct netlink_ext_ack *extack) 2155{ 2156 struct fib_alias *fa; 2157 int last_slen = -1; 2158 int err; 2159 2160 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 2161 struct fib_info *fi = fa->fa_info; 2162 2163 if (!fi) 2164 continue; 2165 2166 /* local and main table can share the same trie, 2167 * so don't notify twice for the same entry. 2168 */ 2169 if (tb->tb_id != fa->tb_id) 2170 continue; 2171 2172 if (fa->fa_slen == last_slen) 2173 continue; 2174 2175 last_slen = fa->fa_slen; 2176 err = call_fib_entry_notifier(nb, FIB_EVENT_ENTRY_REPLACE, 2177 l->key, KEYLENGTH - fa->fa_slen, 2178 fa, extack); 2179 if (err) 2180 return err; 2181 } 2182 return 0; 2183} 2184 2185static int fib_table_notify(struct fib_table *tb, struct notifier_block *nb, 2186 struct netlink_ext_ack *extack) 2187{ 2188 struct trie *t = (struct trie *)tb->tb_data; 2189 struct key_vector *l, *tp = t->kv; 2190 t_key key = 0; 2191 int err; 2192 2193 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 2194 err = fib_leaf_notify(l, tb, nb, extack); 2195 if (err) 2196 return err; 2197 2198 key = l->key + 1; 2199 /* stop in case of wrap around */ 2200 if (key < l->key) 2201 break; 2202 } 2203 return 0; 2204} 2205 2206int fib_notify(struct net *net, struct notifier_block *nb, 2207 struct netlink_ext_ack *extack) 2208{ 2209 unsigned int h; 2210 int err; 2211 2212 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2213 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2214 struct fib_table *tb; 2215 2216 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2217 err = fib_table_notify(tb, nb, extack); 2218 if (err) 2219 return err; 2220 } 2221 } 2222 return 0; 2223} 2224 2225static void __trie_free_rcu(struct rcu_head *head) 2226{ 2227 struct fib_table *tb = container_of(head, struct fib_table, rcu); 2228#ifdef CONFIG_IP_FIB_TRIE_STATS 2229 struct trie *t = (struct trie *)tb->tb_data; 2230 2231 if (tb->tb_data == tb->__data) 2232 free_percpu(t->stats); 2233#endif /* CONFIG_IP_FIB_TRIE_STATS */ 2234 kfree(tb); 2235} 2236 2237void fib_free_table(struct fib_table *tb) 2238{ 2239 call_rcu(&tb->rcu, __trie_free_rcu); 2240} 2241 2242static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb, 2243 struct sk_buff *skb, struct netlink_callback *cb, 2244 struct fib_dump_filter *filter) 2245{ 2246 unsigned int flags = NLM_F_MULTI; 2247 __be32 xkey = htonl(l->key); 2248 int i, s_i, i_fa, s_fa, err; 2249 struct fib_alias *fa; 2250 2251 if (filter->filter_set || 2252 !filter->dump_exceptions || !filter->dump_routes) 2253 flags |= NLM_F_DUMP_FILTERED; 2254 2255 s_i = cb->args[4]; 2256 s_fa = cb->args[5]; 2257 i = 0; 2258 2259 /* rcu_read_lock is hold by caller */ 2260 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 2261 struct fib_info *fi = fa->fa_info; 2262 2263 if (i < s_i) 2264 goto next; 2265 2266 i_fa = 0; 2267 2268 if (tb->tb_id != fa->tb_id) 2269 goto next; 2270 2271 if (filter->filter_set) { 2272 if (filter->rt_type && fa->fa_type != filter->rt_type) 2273 goto next; 2274 2275 if ((filter->protocol && 2276 fi->fib_protocol != filter->protocol)) 2277 goto next; 2278 2279 if (filter->dev && 2280 !fib_info_nh_uses_dev(fi, filter->dev)) 2281 goto next; 2282 } 2283 2284 if (filter->dump_routes) { 2285 if (!s_fa) { 2286 struct fib_rt_info fri; 2287 2288 fri.fi = fi; 2289 fri.tb_id = tb->tb_id; 2290 fri.dst = xkey; 2291 fri.dst_len = KEYLENGTH - fa->fa_slen; 2292 fri.dscp = fa->fa_dscp; 2293 fri.type = fa->fa_type; 2294 fri.offload = READ_ONCE(fa->offload); 2295 fri.trap = READ_ONCE(fa->trap); 2296 fri.offload_failed = READ_ONCE(fa->offload_failed); 2297 err = fib_dump_info(skb, 2298 NETLINK_CB(cb->skb).portid, 2299 cb->nlh->nlmsg_seq, 2300 RTM_NEWROUTE, &fri, flags); 2301 if (err < 0) 2302 goto stop; 2303 } 2304 2305 i_fa++; 2306 } 2307 2308 if (filter->dump_exceptions) { 2309 err = fib_dump_info_fnhe(skb, cb, tb->tb_id, fi, 2310 &i_fa, s_fa, flags); 2311 if (err < 0) 2312 goto stop; 2313 } 2314 2315next: 2316 i++; 2317 } 2318 2319 cb->args[4] = i; 2320 return skb->len; 2321 2322stop: 2323 cb->args[4] = i; 2324 cb->args[5] = i_fa; 2325 return err; 2326} 2327 2328/* rcu_read_lock needs to be hold by caller from readside */ 2329int fib_table_dump(struct fib_table *tb, struct sk_buff *skb, 2330 struct netlink_callback *cb, struct fib_dump_filter *filter) 2331{ 2332 struct trie *t = (struct trie *)tb->tb_data; 2333 struct key_vector *l, *tp = t->kv; 2334 /* Dump starting at last key. 2335 * Note: 0.0.0.0/0 (ie default) is first key. 2336 */ 2337 int count = cb->args[2]; 2338 t_key key = cb->args[3]; 2339 2340 /* First time here, count and key are both always 0. Count > 0 2341 * and key == 0 means the dump has wrapped around and we are done. 2342 */ 2343 if (count && !key) 2344 return 0; 2345 2346 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 2347 int err; 2348 2349 err = fn_trie_dump_leaf(l, tb, skb, cb, filter); 2350 if (err < 0) { 2351 cb->args[3] = key; 2352 cb->args[2] = count; 2353 return err; 2354 } 2355 2356 ++count; 2357 key = l->key + 1; 2358 2359 memset(&cb->args[4], 0, 2360 sizeof(cb->args) - 4*sizeof(cb->args[0])); 2361 2362 /* stop loop if key wrapped back to 0 */ 2363 if (key < l->key) 2364 break; 2365 } 2366 2367 cb->args[3] = key; 2368 cb->args[2] = count; 2369 2370 return 0; 2371} 2372 2373void __init fib_trie_init(void) 2374{ 2375 fn_alias_kmem = kmem_cache_create("ip_fib_alias", 2376 sizeof(struct fib_alias), 2377 0, SLAB_PANIC | SLAB_ACCOUNT, NULL); 2378 2379 trie_leaf_kmem = kmem_cache_create("ip_fib_trie", 2380 LEAF_SIZE, 2381 0, SLAB_PANIC | SLAB_ACCOUNT, NULL); 2382} 2383 2384struct fib_table *fib_trie_table(u32 id, struct fib_table *alias) 2385{ 2386 struct fib_table *tb; 2387 struct trie *t; 2388 size_t sz = sizeof(*tb); 2389 2390 if (!alias) 2391 sz += sizeof(struct trie); 2392 2393 tb = kzalloc(sz, GFP_KERNEL); 2394 if (!tb) 2395 return NULL; 2396 2397 tb->tb_id = id; 2398 tb->tb_num_default = 0; 2399 tb->tb_data = (alias ? alias->__data : tb->__data); 2400 2401 if (alias) 2402 return tb; 2403 2404 t = (struct trie *) tb->tb_data; 2405 t->kv[0].pos = KEYLENGTH; 2406 t->kv[0].slen = KEYLENGTH; 2407#ifdef CONFIG_IP_FIB_TRIE_STATS 2408 t->stats = alloc_percpu(struct trie_use_stats); 2409 if (!t->stats) { 2410 kfree(tb); 2411 tb = NULL; 2412 } 2413#endif 2414 2415 return tb; 2416} 2417 2418#ifdef CONFIG_PROC_FS 2419/* Depth first Trie walk iterator */ 2420struct fib_trie_iter { 2421 struct seq_net_private p; 2422 struct fib_table *tb; 2423 struct key_vector *tnode; 2424 unsigned int index; 2425 unsigned int depth; 2426}; 2427 2428static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter) 2429{ 2430 unsigned long cindex = iter->index; 2431 struct key_vector *pn = iter->tnode; 2432 t_key pkey; 2433 2434 pr_debug("get_next iter={node=%p index=%d depth=%d}\n", 2435 iter->tnode, iter->index, iter->depth); 2436 2437 while (!IS_TRIE(pn)) { 2438 while (cindex < child_length(pn)) { 2439 struct key_vector *n = get_child_rcu(pn, cindex++); 2440 2441 if (!n) 2442 continue; 2443 2444 if (IS_LEAF(n)) { 2445 iter->tnode = pn; 2446 iter->index = cindex; 2447 } else { 2448 /* push down one level */ 2449 iter->tnode = n; 2450 iter->index = 0; 2451 ++iter->depth; 2452 } 2453 2454 return n; 2455 } 2456 2457 /* Current node exhausted, pop back up */ 2458 pkey = pn->key; 2459 pn = node_parent_rcu(pn); 2460 cindex = get_index(pkey, pn) + 1; 2461 --iter->depth; 2462 } 2463 2464 /* record root node so further searches know we are done */ 2465 iter->tnode = pn; 2466 iter->index = 0; 2467 2468 return NULL; 2469} 2470 2471static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter, 2472 struct trie *t) 2473{ 2474 struct key_vector *n, *pn; 2475 2476 if (!t) 2477 return NULL; 2478 2479 pn = t->kv; 2480 n = rcu_dereference(pn->tnode[0]); 2481 if (!n) 2482 return NULL; 2483 2484 if (IS_TNODE(n)) { 2485 iter->tnode = n; 2486 iter->index = 0; 2487 iter->depth = 1; 2488 } else { 2489 iter->tnode = pn; 2490 iter->index = 0; 2491 iter->depth = 0; 2492 } 2493 2494 return n; 2495} 2496 2497static void trie_collect_stats(struct trie *t, struct trie_stat *s) 2498{ 2499 struct key_vector *n; 2500 struct fib_trie_iter iter; 2501 2502 memset(s, 0, sizeof(*s)); 2503 2504 rcu_read_lock(); 2505 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) { 2506 if (IS_LEAF(n)) { 2507 struct fib_alias *fa; 2508 2509 s->leaves++; 2510 s->totdepth += iter.depth; 2511 if (iter.depth > s->maxdepth) 2512 s->maxdepth = iter.depth; 2513 2514 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) 2515 ++s->prefixes; 2516 } else { 2517 s->tnodes++; 2518 if (n->bits < MAX_STAT_DEPTH) 2519 s->nodesizes[n->bits]++; 2520 s->nullpointers += tn_info(n)->empty_children; 2521 } 2522 } 2523 rcu_read_unlock(); 2524} 2525 2526/* 2527 * This outputs /proc/net/fib_triestats 2528 */ 2529static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat) 2530{ 2531 unsigned int i, max, pointers, bytes, avdepth; 2532 2533 if (stat->leaves) 2534 avdepth = stat->totdepth*100 / stat->leaves; 2535 else 2536 avdepth = 0; 2537 2538 seq_printf(seq, "\tAver depth: %u.%02d\n", 2539 avdepth / 100, avdepth % 100); 2540 seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth); 2541 2542 seq_printf(seq, "\tLeaves: %u\n", stat->leaves); 2543 bytes = LEAF_SIZE * stat->leaves; 2544 2545 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes); 2546 bytes += sizeof(struct fib_alias) * stat->prefixes; 2547 2548 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes); 2549 bytes += TNODE_SIZE(0) * stat->tnodes; 2550 2551 max = MAX_STAT_DEPTH; 2552 while (max > 0 && stat->nodesizes[max-1] == 0) 2553 max--; 2554 2555 pointers = 0; 2556 for (i = 1; i < max; i++) 2557 if (stat->nodesizes[i] != 0) { 2558 seq_printf(seq, " %u: %u", i, stat->nodesizes[i]); 2559 pointers += (1<<i) * stat->nodesizes[i]; 2560 } 2561 seq_putc(seq, '\n'); 2562 seq_printf(seq, "\tPointers: %u\n", pointers); 2563 2564 bytes += sizeof(struct key_vector *) * pointers; 2565 seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers); 2566 seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024); 2567} 2568 2569#ifdef CONFIG_IP_FIB_TRIE_STATS 2570static void trie_show_usage(struct seq_file *seq, 2571 const struct trie_use_stats __percpu *stats) 2572{ 2573 struct trie_use_stats s = { 0 }; 2574 int cpu; 2575 2576 /* loop through all of the CPUs and gather up the stats */ 2577 for_each_possible_cpu(cpu) { 2578 const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu); 2579 2580 s.gets += pcpu->gets; 2581 s.backtrack += pcpu->backtrack; 2582 s.semantic_match_passed += pcpu->semantic_match_passed; 2583 s.semantic_match_miss += pcpu->semantic_match_miss; 2584 s.null_node_hit += pcpu->null_node_hit; 2585 s.resize_node_skipped += pcpu->resize_node_skipped; 2586 } 2587 2588 seq_printf(seq, "\nCounters:\n---------\n"); 2589 seq_printf(seq, "gets = %u\n", s.gets); 2590 seq_printf(seq, "backtracks = %u\n", s.backtrack); 2591 seq_printf(seq, "semantic match passed = %u\n", 2592 s.semantic_match_passed); 2593 seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss); 2594 seq_printf(seq, "null node hit= %u\n", s.null_node_hit); 2595 seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped); 2596} 2597#endif /* CONFIG_IP_FIB_TRIE_STATS */ 2598 2599static void fib_table_print(struct seq_file *seq, struct fib_table *tb) 2600{ 2601 if (tb->tb_id == RT_TABLE_LOCAL) 2602 seq_puts(seq, "Local:\n"); 2603 else if (tb->tb_id == RT_TABLE_MAIN) 2604 seq_puts(seq, "Main:\n"); 2605 else 2606 seq_printf(seq, "Id %d:\n", tb->tb_id); 2607} 2608 2609 2610static int fib_triestat_seq_show(struct seq_file *seq, void *v) 2611{ 2612 struct net *net = seq->private; 2613 unsigned int h; 2614 2615 seq_printf(seq, 2616 "Basic info: size of leaf:" 2617 " %zd bytes, size of tnode: %zd bytes.\n", 2618 LEAF_SIZE, TNODE_SIZE(0)); 2619 2620 rcu_read_lock(); 2621 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2622 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2623 struct fib_table *tb; 2624 2625 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2626 struct trie *t = (struct trie *) tb->tb_data; 2627 struct trie_stat stat; 2628 2629 if (!t) 2630 continue; 2631 2632 fib_table_print(seq, tb); 2633 2634 trie_collect_stats(t, &stat); 2635 trie_show_stats(seq, &stat); 2636#ifdef CONFIG_IP_FIB_TRIE_STATS 2637 trie_show_usage(seq, t->stats); 2638#endif 2639 } 2640 cond_resched_rcu(); 2641 } 2642 rcu_read_unlock(); 2643 2644 return 0; 2645} 2646 2647static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos) 2648{ 2649 struct fib_trie_iter *iter = seq->private; 2650 struct net *net = seq_file_net(seq); 2651 loff_t idx = 0; 2652 unsigned int h; 2653 2654 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2655 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2656 struct fib_table *tb; 2657 2658 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2659 struct key_vector *n; 2660 2661 for (n = fib_trie_get_first(iter, 2662 (struct trie *) tb->tb_data); 2663 n; n = fib_trie_get_next(iter)) 2664 if (pos == idx++) { 2665 iter->tb = tb; 2666 return n; 2667 } 2668 } 2669 } 2670 2671 return NULL; 2672} 2673 2674static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos) 2675 __acquires(RCU) 2676{ 2677 rcu_read_lock(); 2678 return fib_trie_get_idx(seq, *pos); 2679} 2680 2681static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2682{ 2683 struct fib_trie_iter *iter = seq->private; 2684 struct net *net = seq_file_net(seq); 2685 struct fib_table *tb = iter->tb; 2686 struct hlist_node *tb_node; 2687 unsigned int h; 2688 struct key_vector *n; 2689 2690 ++*pos; 2691 /* next node in same table */ 2692 n = fib_trie_get_next(iter); 2693 if (n) 2694 return n; 2695 2696 /* walk rest of this hash chain */ 2697 h = tb->tb_id & (FIB_TABLE_HASHSZ - 1); 2698 while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) { 2699 tb = hlist_entry(tb_node, struct fib_table, tb_hlist); 2700 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data); 2701 if (n) 2702 goto found; 2703 } 2704 2705 /* new hash chain */ 2706 while (++h < FIB_TABLE_HASHSZ) { 2707 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2708 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2709 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data); 2710 if (n) 2711 goto found; 2712 } 2713 } 2714 return NULL; 2715 2716found: 2717 iter->tb = tb; 2718 return n; 2719} 2720 2721static void fib_trie_seq_stop(struct seq_file *seq, void *v) 2722 __releases(RCU) 2723{ 2724 rcu_read_unlock(); 2725} 2726 2727static void seq_indent(struct seq_file *seq, int n) 2728{ 2729 while (n-- > 0) 2730 seq_puts(seq, " "); 2731} 2732 2733static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s) 2734{ 2735 switch (s) { 2736 case RT_SCOPE_UNIVERSE: return "universe"; 2737 case RT_SCOPE_SITE: return "site"; 2738 case RT_SCOPE_LINK: return "link"; 2739 case RT_SCOPE_HOST: return "host"; 2740 case RT_SCOPE_NOWHERE: return "nowhere"; 2741 default: 2742 snprintf(buf, len, "scope=%d", s); 2743 return buf; 2744 } 2745} 2746 2747static const char *const rtn_type_names[__RTN_MAX] = { 2748 [RTN_UNSPEC] = "UNSPEC", 2749 [RTN_UNICAST] = "UNICAST", 2750 [RTN_LOCAL] = "LOCAL", 2751 [RTN_BROADCAST] = "BROADCAST", 2752 [RTN_ANYCAST] = "ANYCAST", 2753 [RTN_MULTICAST] = "MULTICAST", 2754 [RTN_BLACKHOLE] = "BLACKHOLE", 2755 [RTN_UNREACHABLE] = "UNREACHABLE", 2756 [RTN_PROHIBIT] = "PROHIBIT", 2757 [RTN_THROW] = "THROW", 2758 [RTN_NAT] = "NAT", 2759 [RTN_XRESOLVE] = "XRESOLVE", 2760}; 2761 2762static inline const char *rtn_type(char *buf, size_t len, unsigned int t) 2763{ 2764 if (t < __RTN_MAX && rtn_type_names[t]) 2765 return rtn_type_names[t]; 2766 snprintf(buf, len, "type %u", t); 2767 return buf; 2768} 2769 2770/* Pretty print the trie */ 2771static int fib_trie_seq_show(struct seq_file *seq, void *v) 2772{ 2773 const struct fib_trie_iter *iter = seq->private; 2774 struct key_vector *n = v; 2775 2776 if (IS_TRIE(node_parent_rcu(n))) 2777 fib_table_print(seq, iter->tb); 2778 2779 if (IS_TNODE(n)) { 2780 __be32 prf = htonl(n->key); 2781 2782 seq_indent(seq, iter->depth-1); 2783 seq_printf(seq, " +-- %pI4/%zu %u %u %u\n", 2784 &prf, KEYLENGTH - n->pos - n->bits, n->bits, 2785 tn_info(n)->full_children, 2786 tn_info(n)->empty_children); 2787 } else { 2788 __be32 val = htonl(n->key); 2789 struct fib_alias *fa; 2790 2791 seq_indent(seq, iter->depth); 2792 seq_printf(seq, " |-- %pI4\n", &val); 2793 2794 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) { 2795 char buf1[32], buf2[32]; 2796 2797 seq_indent(seq, iter->depth + 1); 2798 seq_printf(seq, " /%zu %s %s", 2799 KEYLENGTH - fa->fa_slen, 2800 rtn_scope(buf1, sizeof(buf1), 2801 fa->fa_info->fib_scope), 2802 rtn_type(buf2, sizeof(buf2), 2803 fa->fa_type)); 2804 if (fa->fa_dscp) 2805 seq_printf(seq, " tos=%d", 2806 inet_dscp_to_dsfield(fa->fa_dscp)); 2807 seq_putc(seq, '\n'); 2808 } 2809 } 2810 2811 return 0; 2812} 2813 2814static const struct seq_operations fib_trie_seq_ops = { 2815 .start = fib_trie_seq_start, 2816 .next = fib_trie_seq_next, 2817 .stop = fib_trie_seq_stop, 2818 .show = fib_trie_seq_show, 2819}; 2820 2821struct fib_route_iter { 2822 struct seq_net_private p; 2823 struct fib_table *main_tb; 2824 struct key_vector *tnode; 2825 loff_t pos; 2826 t_key key; 2827}; 2828 2829static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter, 2830 loff_t pos) 2831{ 2832 struct key_vector *l, **tp = &iter->tnode; 2833 t_key key; 2834 2835 /* use cached location of previously found key */ 2836 if (iter->pos > 0 && pos >= iter->pos) { 2837 key = iter->key; 2838 } else { 2839 iter->pos = 1; 2840 key = 0; 2841 } 2842 2843 pos -= iter->pos; 2844 2845 while ((l = leaf_walk_rcu(tp, key)) && (pos-- > 0)) { 2846 key = l->key + 1; 2847 iter->pos++; 2848 l = NULL; 2849 2850 /* handle unlikely case of a key wrap */ 2851 if (!key) 2852 break; 2853 } 2854 2855 if (l) 2856 iter->key = l->key; /* remember it */ 2857 else 2858 iter->pos = 0; /* forget it */ 2859 2860 return l; 2861} 2862 2863static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos) 2864 __acquires(RCU) 2865{ 2866 struct fib_route_iter *iter = seq->private; 2867 struct fib_table *tb; 2868 struct trie *t; 2869 2870 rcu_read_lock(); 2871 2872 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN); 2873 if (!tb) 2874 return NULL; 2875 2876 iter->main_tb = tb; 2877 t = (struct trie *)tb->tb_data; 2878 iter->tnode = t->kv; 2879 2880 if (*pos != 0) 2881 return fib_route_get_idx(iter, *pos); 2882 2883 iter->pos = 0; 2884 iter->key = KEY_MAX; 2885 2886 return SEQ_START_TOKEN; 2887} 2888 2889static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2890{ 2891 struct fib_route_iter *iter = seq->private; 2892 struct key_vector *l = NULL; 2893 t_key key = iter->key + 1; 2894 2895 ++*pos; 2896 2897 /* only allow key of 0 for start of sequence */ 2898 if ((v == SEQ_START_TOKEN) || key) 2899 l = leaf_walk_rcu(&iter->tnode, key); 2900 2901 if (l) { 2902 iter->key = l->key; 2903 iter->pos++; 2904 } else { 2905 iter->pos = 0; 2906 } 2907 2908 return l; 2909} 2910 2911static void fib_route_seq_stop(struct seq_file *seq, void *v) 2912 __releases(RCU) 2913{ 2914 rcu_read_unlock(); 2915} 2916 2917static unsigned int fib_flag_trans(int type, __be32 mask, struct fib_info *fi) 2918{ 2919 unsigned int flags = 0; 2920 2921 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT) 2922 flags = RTF_REJECT; 2923 if (fi) { 2924 const struct fib_nh_common *nhc = fib_info_nhc(fi, 0); 2925 2926 if (nhc->nhc_gw.ipv4) 2927 flags |= RTF_GATEWAY; 2928 } 2929 if (mask == htonl(0xFFFFFFFF)) 2930 flags |= RTF_HOST; 2931 flags |= RTF_UP; 2932 return flags; 2933} 2934 2935/* 2936 * This outputs /proc/net/route. 2937 * The format of the file is not supposed to be changed 2938 * and needs to be same as fib_hash output to avoid breaking 2939 * legacy utilities 2940 */ 2941static int fib_route_seq_show(struct seq_file *seq, void *v) 2942{ 2943 struct fib_route_iter *iter = seq->private; 2944 struct fib_table *tb = iter->main_tb; 2945 struct fib_alias *fa; 2946 struct key_vector *l = v; 2947 __be32 prefix; 2948 2949 if (v == SEQ_START_TOKEN) { 2950 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway " 2951 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU" 2952 "\tWindow\tIRTT"); 2953 return 0; 2954 } 2955 2956 prefix = htonl(l->key); 2957 2958 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 2959 struct fib_info *fi = fa->fa_info; 2960 __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen); 2961 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi); 2962 2963 if ((fa->fa_type == RTN_BROADCAST) || 2964 (fa->fa_type == RTN_MULTICAST)) 2965 continue; 2966 2967 if (fa->tb_id != tb->tb_id) 2968 continue; 2969 2970 seq_setwidth(seq, 127); 2971 2972 if (fi) { 2973 struct fib_nh_common *nhc = fib_info_nhc(fi, 0); 2974 __be32 gw = 0; 2975 2976 if (nhc->nhc_gw_family == AF_INET) 2977 gw = nhc->nhc_gw.ipv4; 2978 2979 seq_printf(seq, 2980 "%s\t%08X\t%08X\t%04X\t%d\t%u\t" 2981 "%u\t%08X\t%d\t%u\t%u", 2982 nhc->nhc_dev ? nhc->nhc_dev->name : "*", 2983 prefix, gw, flags, 0, 0, 2984 fi->fib_priority, 2985 mask, 2986 (fi->fib_advmss ? 2987 fi->fib_advmss + 40 : 0), 2988 fi->fib_window, 2989 fi->fib_rtt >> 3); 2990 } else { 2991 seq_printf(seq, 2992 "*\t%08X\t%08X\t%04X\t%d\t%u\t" 2993 "%u\t%08X\t%d\t%u\t%u", 2994 prefix, 0, flags, 0, 0, 0, 2995 mask, 0, 0, 0); 2996 } 2997 seq_pad(seq, '\n'); 2998 } 2999 3000 return 0; 3001} 3002 3003static const struct seq_operations fib_route_seq_ops = { 3004 .start = fib_route_seq_start, 3005 .next = fib_route_seq_next, 3006 .stop = fib_route_seq_stop, 3007 .show = fib_route_seq_show, 3008}; 3009 3010int __net_init fib_proc_init(struct net *net) 3011{ 3012 if (!proc_create_net("fib_trie", 0444, net->proc_net, &fib_trie_seq_ops, 3013 sizeof(struct fib_trie_iter))) 3014 goto out1; 3015 3016 if (!proc_create_net_single("fib_triestat", 0444, net->proc_net, 3017 fib_triestat_seq_show, NULL)) 3018 goto out2; 3019 3020 if (!proc_create_net("route", 0444, net->proc_net, &fib_route_seq_ops, 3021 sizeof(struct fib_route_iter))) 3022 goto out3; 3023 3024 return 0; 3025 3026out3: 3027 remove_proc_entry("fib_triestat", net->proc_net); 3028out2: 3029 remove_proc_entry("fib_trie", net->proc_net); 3030out1: 3031 return -ENOMEM; 3032} 3033 3034void __net_exit fib_proc_exit(struct net *net) 3035{ 3036 remove_proc_entry("fib_trie", net->proc_net); 3037 remove_proc_entry("fib_triestat", net->proc_net); 3038 remove_proc_entry("route", net->proc_net); 3039} 3040 3041#endif /* CONFIG_PROC_FS */
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