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 void __alias_free_mem(struct rcu_head *head) 296{ 297 struct fib_alias *fa = container_of(head, struct fib_alias, rcu); 298 kmem_cache_free(fn_alias_kmem, fa); 299} 300 301static inline void alias_free_mem_rcu(struct fib_alias *fa) 302{ 303 call_rcu(&fa->rcu, __alias_free_mem); 304} 305 306#define TNODE_VMALLOC_MAX \ 307 ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *)) 308 309static void __node_free_rcu(struct rcu_head *head) 310{ 311 struct tnode *n = container_of(head, struct tnode, rcu); 312 313 if (!n->tn_bits) 314 kmem_cache_free(trie_leaf_kmem, n); 315 else 316 kvfree(n); 317} 318 319#define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu) 320 321static struct tnode *tnode_alloc(int bits) 322{ 323 size_t size; 324 325 /* verify bits is within bounds */ 326 if (bits > TNODE_VMALLOC_MAX) 327 return NULL; 328 329 /* determine size and verify it is non-zero and didn't overflow */ 330 size = TNODE_SIZE(1ul << bits); 331 332 if (size <= PAGE_SIZE) 333 return kzalloc(size, GFP_KERNEL); 334 else 335 return vzalloc(size); 336} 337 338static inline void empty_child_inc(struct key_vector *n) 339{ 340 tn_info(n)->empty_children++; 341 342 if (!tn_info(n)->empty_children) 343 tn_info(n)->full_children++; 344} 345 346static inline void empty_child_dec(struct key_vector *n) 347{ 348 if (!tn_info(n)->empty_children) 349 tn_info(n)->full_children--; 350 351 tn_info(n)->empty_children--; 352} 353 354static struct key_vector *leaf_new(t_key key, struct fib_alias *fa) 355{ 356 struct key_vector *l; 357 struct tnode *kv; 358 359 kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL); 360 if (!kv) 361 return NULL; 362 363 /* initialize key vector */ 364 l = kv->kv; 365 l->key = key; 366 l->pos = 0; 367 l->bits = 0; 368 l->slen = fa->fa_slen; 369 370 /* link leaf to fib alias */ 371 INIT_HLIST_HEAD(&l->leaf); 372 hlist_add_head(&fa->fa_list, &l->leaf); 373 374 return l; 375} 376 377static struct key_vector *tnode_new(t_key key, int pos, int bits) 378{ 379 unsigned int shift = pos + bits; 380 struct key_vector *tn; 381 struct tnode *tnode; 382 383 /* verify bits and pos their msb bits clear and values are valid */ 384 BUG_ON(!bits || (shift > KEYLENGTH)); 385 386 tnode = tnode_alloc(bits); 387 if (!tnode) 388 return NULL; 389 390 pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0), 391 sizeof(struct key_vector *) << bits); 392 393 if (bits == KEYLENGTH) 394 tnode->full_children = 1; 395 else 396 tnode->empty_children = 1ul << bits; 397 398 tn = tnode->kv; 399 tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0; 400 tn->pos = pos; 401 tn->bits = bits; 402 tn->slen = pos; 403 404 return tn; 405} 406 407/* Check whether a tnode 'n' is "full", i.e. it is an internal node 408 * and no bits are skipped. See discussion in dyntree paper p. 6 409 */ 410static inline int tnode_full(struct key_vector *tn, struct key_vector *n) 411{ 412 return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n); 413} 414 415/* Add a child at position i overwriting the old value. 416 * Update the value of full_children and empty_children. 417 */ 418static void put_child(struct key_vector *tn, unsigned long i, 419 struct key_vector *n) 420{ 421 struct key_vector *chi = get_child(tn, i); 422 int isfull, wasfull; 423 424 BUG_ON(i >= child_length(tn)); 425 426 /* update emptyChildren, overflow into fullChildren */ 427 if (!n && chi) 428 empty_child_inc(tn); 429 if (n && !chi) 430 empty_child_dec(tn); 431 432 /* update fullChildren */ 433 wasfull = tnode_full(tn, chi); 434 isfull = tnode_full(tn, n); 435 436 if (wasfull && !isfull) 437 tn_info(tn)->full_children--; 438 else if (!wasfull && isfull) 439 tn_info(tn)->full_children++; 440 441 if (n && (tn->slen < n->slen)) 442 tn->slen = n->slen; 443 444 rcu_assign_pointer(tn->tnode[i], n); 445} 446 447static void update_children(struct key_vector *tn) 448{ 449 unsigned long i; 450 451 /* update all of the child parent pointers */ 452 for (i = child_length(tn); i;) { 453 struct key_vector *inode = get_child(tn, --i); 454 455 if (!inode) 456 continue; 457 458 /* Either update the children of a tnode that 459 * already belongs to us or update the child 460 * to point to ourselves. 461 */ 462 if (node_parent(inode) == tn) 463 update_children(inode); 464 else 465 node_set_parent(inode, tn); 466 } 467} 468 469static inline void put_child_root(struct key_vector *tp, t_key key, 470 struct key_vector *n) 471{ 472 if (IS_TRIE(tp)) 473 rcu_assign_pointer(tp->tnode[0], n); 474 else 475 put_child(tp, get_index(key, tp), n); 476} 477 478static inline void tnode_free_init(struct key_vector *tn) 479{ 480 tn_info(tn)->rcu.next = NULL; 481} 482 483static inline void tnode_free_append(struct key_vector *tn, 484 struct key_vector *n) 485{ 486 tn_info(n)->rcu.next = tn_info(tn)->rcu.next; 487 tn_info(tn)->rcu.next = &tn_info(n)->rcu; 488} 489 490static void tnode_free(struct key_vector *tn) 491{ 492 struct callback_head *head = &tn_info(tn)->rcu; 493 494 while (head) { 495 head = head->next; 496 tnode_free_size += TNODE_SIZE(1ul << tn->bits); 497 node_free(tn); 498 499 tn = container_of(head, struct tnode, rcu)->kv; 500 } 501 502 if (tnode_free_size >= READ_ONCE(sysctl_fib_sync_mem)) { 503 tnode_free_size = 0; 504 synchronize_net(); 505 } 506} 507 508static struct key_vector *replace(struct trie *t, 509 struct key_vector *oldtnode, 510 struct key_vector *tn) 511{ 512 struct key_vector *tp = node_parent(oldtnode); 513 unsigned long i; 514 515 /* setup the parent pointer out of and back into this node */ 516 NODE_INIT_PARENT(tn, tp); 517 put_child_root(tp, tn->key, tn); 518 519 /* update all of the child parent pointers */ 520 update_children(tn); 521 522 /* all pointers should be clean so we are done */ 523 tnode_free(oldtnode); 524 525 /* resize children now that oldtnode is freed */ 526 for (i = child_length(tn); i;) { 527 struct key_vector *inode = get_child(tn, --i); 528 529 /* resize child node */ 530 if (tnode_full(tn, inode)) 531 tn = resize(t, inode); 532 } 533 534 return tp; 535} 536 537static struct key_vector *inflate(struct trie *t, 538 struct key_vector *oldtnode) 539{ 540 struct key_vector *tn; 541 unsigned long i; 542 t_key m; 543 544 pr_debug("In inflate\n"); 545 546 tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1); 547 if (!tn) 548 goto notnode; 549 550 /* prepare oldtnode to be freed */ 551 tnode_free_init(oldtnode); 552 553 /* Assemble all of the pointers in our cluster, in this case that 554 * represents all of the pointers out of our allocated nodes that 555 * point to existing tnodes and the links between our allocated 556 * nodes. 557 */ 558 for (i = child_length(oldtnode), m = 1u << tn->pos; i;) { 559 struct key_vector *inode = get_child(oldtnode, --i); 560 struct key_vector *node0, *node1; 561 unsigned long j, k; 562 563 /* An empty child */ 564 if (!inode) 565 continue; 566 567 /* A leaf or an internal node with skipped bits */ 568 if (!tnode_full(oldtnode, inode)) { 569 put_child(tn, get_index(inode->key, tn), inode); 570 continue; 571 } 572 573 /* drop the node in the old tnode free list */ 574 tnode_free_append(oldtnode, inode); 575 576 /* An internal node with two children */ 577 if (inode->bits == 1) { 578 put_child(tn, 2 * i + 1, get_child(inode, 1)); 579 put_child(tn, 2 * i, get_child(inode, 0)); 580 continue; 581 } 582 583 /* We will replace this node 'inode' with two new 584 * ones, 'node0' and 'node1', each with half of the 585 * original children. The two new nodes will have 586 * a position one bit further down the key and this 587 * means that the "significant" part of their keys 588 * (see the discussion near the top of this file) 589 * will differ by one bit, which will be "0" in 590 * node0's key and "1" in node1's key. Since we are 591 * moving the key position by one step, the bit that 592 * we are moving away from - the bit at position 593 * (tn->pos) - is the one that will differ between 594 * node0 and node1. So... we synthesize that bit in the 595 * two new keys. 596 */ 597 node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1); 598 if (!node1) 599 goto nomem; 600 node0 = tnode_new(inode->key, inode->pos, inode->bits - 1); 601 602 tnode_free_append(tn, node1); 603 if (!node0) 604 goto nomem; 605 tnode_free_append(tn, node0); 606 607 /* populate child pointers in new nodes */ 608 for (k = child_length(inode), j = k / 2; j;) { 609 put_child(node1, --j, get_child(inode, --k)); 610 put_child(node0, j, get_child(inode, j)); 611 put_child(node1, --j, get_child(inode, --k)); 612 put_child(node0, j, get_child(inode, j)); 613 } 614 615 /* link new nodes to parent */ 616 NODE_INIT_PARENT(node1, tn); 617 NODE_INIT_PARENT(node0, tn); 618 619 /* link parent to nodes */ 620 put_child(tn, 2 * i + 1, node1); 621 put_child(tn, 2 * i, node0); 622 } 623 624 /* setup the parent pointers into and out of this node */ 625 return replace(t, oldtnode, tn); 626nomem: 627 /* all pointers should be clean so we are done */ 628 tnode_free(tn); 629notnode: 630 return NULL; 631} 632 633static struct key_vector *halve(struct trie *t, 634 struct key_vector *oldtnode) 635{ 636 struct key_vector *tn; 637 unsigned long i; 638 639 pr_debug("In halve\n"); 640 641 tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1); 642 if (!tn) 643 goto notnode; 644 645 /* prepare oldtnode to be freed */ 646 tnode_free_init(oldtnode); 647 648 /* Assemble all of the pointers in our cluster, in this case that 649 * represents all of the pointers out of our allocated nodes that 650 * point to existing tnodes and the links between our allocated 651 * nodes. 652 */ 653 for (i = child_length(oldtnode); i;) { 654 struct key_vector *node1 = get_child(oldtnode, --i); 655 struct key_vector *node0 = get_child(oldtnode, --i); 656 struct key_vector *inode; 657 658 /* At least one of the children is empty */ 659 if (!node1 || !node0) { 660 put_child(tn, i / 2, node1 ? : node0); 661 continue; 662 } 663 664 /* Two nonempty children */ 665 inode = tnode_new(node0->key, oldtnode->pos, 1); 666 if (!inode) 667 goto nomem; 668 tnode_free_append(tn, inode); 669 670 /* initialize pointers out of node */ 671 put_child(inode, 1, node1); 672 put_child(inode, 0, node0); 673 NODE_INIT_PARENT(inode, tn); 674 675 /* link parent to node */ 676 put_child(tn, i / 2, inode); 677 } 678 679 /* setup the parent pointers into and out of this node */ 680 return replace(t, oldtnode, tn); 681nomem: 682 /* all pointers should be clean so we are done */ 683 tnode_free(tn); 684notnode: 685 return NULL; 686} 687 688static struct key_vector *collapse(struct trie *t, 689 struct key_vector *oldtnode) 690{ 691 struct key_vector *n, *tp; 692 unsigned long i; 693 694 /* scan the tnode looking for that one child that might still exist */ 695 for (n = NULL, i = child_length(oldtnode); !n && i;) 696 n = get_child(oldtnode, --i); 697 698 /* compress one level */ 699 tp = node_parent(oldtnode); 700 put_child_root(tp, oldtnode->key, n); 701 node_set_parent(n, tp); 702 703 /* drop dead node */ 704 node_free(oldtnode); 705 706 return tp; 707} 708 709static unsigned char update_suffix(struct key_vector *tn) 710{ 711 unsigned char slen = tn->pos; 712 unsigned long stride, i; 713 unsigned char slen_max; 714 715 /* only vector 0 can have a suffix length greater than or equal to 716 * tn->pos + tn->bits, the second highest node will have a suffix 717 * length at most of tn->pos + tn->bits - 1 718 */ 719 slen_max = min_t(unsigned char, tn->pos + tn->bits - 1, tn->slen); 720 721 /* search though the list of children looking for nodes that might 722 * have a suffix greater than the one we currently have. This is 723 * why we start with a stride of 2 since a stride of 1 would 724 * represent the nodes with suffix length equal to tn->pos 725 */ 726 for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) { 727 struct key_vector *n = get_child(tn, i); 728 729 if (!n || (n->slen <= slen)) 730 continue; 731 732 /* update stride and slen based on new value */ 733 stride <<= (n->slen - slen); 734 slen = n->slen; 735 i &= ~(stride - 1); 736 737 /* stop searching if we have hit the maximum possible value */ 738 if (slen >= slen_max) 739 break; 740 } 741 742 tn->slen = slen; 743 744 return slen; 745} 746 747/* From "Implementing a dynamic compressed trie" by Stefan Nilsson of 748 * the Helsinki University of Technology and Matti Tikkanen of Nokia 749 * Telecommunications, page 6: 750 * "A node is doubled if the ratio of non-empty children to all 751 * children in the *doubled* node is at least 'high'." 752 * 753 * 'high' in this instance is the variable 'inflate_threshold'. It 754 * is expressed as a percentage, so we multiply it with 755 * child_length() and instead of multiplying by 2 (since the 756 * child array will be doubled by inflate()) and multiplying 757 * the left-hand side by 100 (to handle the percentage thing) we 758 * multiply the left-hand side by 50. 759 * 760 * The left-hand side may look a bit weird: child_length(tn) 761 * - tn->empty_children is of course the number of non-null children 762 * in the current node. tn->full_children is the number of "full" 763 * children, that is non-null tnodes with a skip value of 0. 764 * All of those will be doubled in the resulting inflated tnode, so 765 * we just count them one extra time here. 766 * 767 * A clearer way to write this would be: 768 * 769 * to_be_doubled = tn->full_children; 770 * not_to_be_doubled = child_length(tn) - tn->empty_children - 771 * tn->full_children; 772 * 773 * new_child_length = child_length(tn) * 2; 774 * 775 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) / 776 * new_child_length; 777 * if (new_fill_factor >= inflate_threshold) 778 * 779 * ...and so on, tho it would mess up the while () loop. 780 * 781 * anyway, 782 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >= 783 * inflate_threshold 784 * 785 * avoid a division: 786 * 100 * (not_to_be_doubled + 2*to_be_doubled) >= 787 * inflate_threshold * new_child_length 788 * 789 * expand not_to_be_doubled and to_be_doubled, and shorten: 790 * 100 * (child_length(tn) - tn->empty_children + 791 * tn->full_children) >= inflate_threshold * new_child_length 792 * 793 * expand new_child_length: 794 * 100 * (child_length(tn) - tn->empty_children + 795 * tn->full_children) >= 796 * inflate_threshold * child_length(tn) * 2 797 * 798 * shorten again: 799 * 50 * (tn->full_children + child_length(tn) - 800 * tn->empty_children) >= inflate_threshold * 801 * child_length(tn) 802 * 803 */ 804static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn) 805{ 806 unsigned long used = child_length(tn); 807 unsigned long threshold = used; 808 809 /* Keep root node larger */ 810 threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold; 811 used -= tn_info(tn)->empty_children; 812 used += tn_info(tn)->full_children; 813 814 /* if bits == KEYLENGTH then pos = 0, and will fail below */ 815 816 return (used > 1) && tn->pos && ((50 * used) >= threshold); 817} 818 819static inline bool should_halve(struct key_vector *tp, struct key_vector *tn) 820{ 821 unsigned long used = child_length(tn); 822 unsigned long threshold = used; 823 824 /* Keep root node larger */ 825 threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold; 826 used -= tn_info(tn)->empty_children; 827 828 /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */ 829 830 return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold); 831} 832 833static inline bool should_collapse(struct key_vector *tn) 834{ 835 unsigned long used = child_length(tn); 836 837 used -= tn_info(tn)->empty_children; 838 839 /* account for bits == KEYLENGTH case */ 840 if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children) 841 used -= KEY_MAX; 842 843 /* One child or none, time to drop us from the trie */ 844 return used < 2; 845} 846 847#define MAX_WORK 10 848static struct key_vector *resize(struct trie *t, struct key_vector *tn) 849{ 850#ifdef CONFIG_IP_FIB_TRIE_STATS 851 struct trie_use_stats __percpu *stats = t->stats; 852#endif 853 struct key_vector *tp = node_parent(tn); 854 unsigned long cindex = get_index(tn->key, tp); 855 int max_work = MAX_WORK; 856 857 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n", 858 tn, inflate_threshold, halve_threshold); 859 860 /* track the tnode via the pointer from the parent instead of 861 * doing it ourselves. This way we can let RCU fully do its 862 * thing without us interfering 863 */ 864 BUG_ON(tn != get_child(tp, cindex)); 865 866 /* Double as long as the resulting node has a number of 867 * nonempty nodes that are above the threshold. 868 */ 869 while (should_inflate(tp, tn) && max_work) { 870 tp = inflate(t, tn); 871 if (!tp) { 872#ifdef CONFIG_IP_FIB_TRIE_STATS 873 this_cpu_inc(stats->resize_node_skipped); 874#endif 875 break; 876 } 877 878 max_work--; 879 tn = get_child(tp, cindex); 880 } 881 882 /* update parent in case inflate failed */ 883 tp = node_parent(tn); 884 885 /* Return if at least one inflate is run */ 886 if (max_work != MAX_WORK) 887 return tp; 888 889 /* Halve as long as the number of empty children in this 890 * node is above threshold. 891 */ 892 while (should_halve(tp, tn) && max_work) { 893 tp = halve(t, tn); 894 if (!tp) { 895#ifdef CONFIG_IP_FIB_TRIE_STATS 896 this_cpu_inc(stats->resize_node_skipped); 897#endif 898 break; 899 } 900 901 max_work--; 902 tn = get_child(tp, cindex); 903 } 904 905 /* Only one child remains */ 906 if (should_collapse(tn)) 907 return collapse(t, tn); 908 909 /* update parent in case halve failed */ 910 return node_parent(tn); 911} 912 913static void node_pull_suffix(struct key_vector *tn, unsigned char slen) 914{ 915 unsigned char node_slen = tn->slen; 916 917 while ((node_slen > tn->pos) && (node_slen > slen)) { 918 slen = update_suffix(tn); 919 if (node_slen == slen) 920 break; 921 922 tn = node_parent(tn); 923 node_slen = tn->slen; 924 } 925} 926 927static void node_push_suffix(struct key_vector *tn, unsigned char slen) 928{ 929 while (tn->slen < slen) { 930 tn->slen = slen; 931 tn = node_parent(tn); 932 } 933} 934 935/* rcu_read_lock needs to be hold by caller from readside */ 936static struct key_vector *fib_find_node(struct trie *t, 937 struct key_vector **tp, u32 key) 938{ 939 struct key_vector *pn, *n = t->kv; 940 unsigned long index = 0; 941 942 do { 943 pn = n; 944 n = get_child_rcu(n, index); 945 946 if (!n) 947 break; 948 949 index = get_cindex(key, n); 950 951 /* This bit of code is a bit tricky but it combines multiple 952 * checks into a single check. The prefix consists of the 953 * prefix plus zeros for the bits in the cindex. The index 954 * is the difference between the key and this value. From 955 * this we can actually derive several pieces of data. 956 * if (index >= (1ul << bits)) 957 * we have a mismatch in skip bits and failed 958 * else 959 * we know the value is cindex 960 * 961 * This check is safe even if bits == KEYLENGTH due to the 962 * fact that we can only allocate a node with 32 bits if a 963 * long is greater than 32 bits. 964 */ 965 if (index >= (1ul << n->bits)) { 966 n = NULL; 967 break; 968 } 969 970 /* keep searching until we find a perfect match leaf or NULL */ 971 } while (IS_TNODE(n)); 972 973 *tp = pn; 974 975 return n; 976} 977 978/* Return the first fib alias matching DSCP with 979 * priority less than or equal to PRIO. 980 * If 'find_first' is set, return the first matching 981 * fib alias, regardless of DSCP and priority. 982 */ 983static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen, 984 dscp_t dscp, u32 prio, u32 tb_id, 985 bool find_first) 986{ 987 struct fib_alias *fa; 988 989 if (!fah) 990 return NULL; 991 992 hlist_for_each_entry(fa, fah, fa_list) { 993 /* Avoid Sparse warning when using dscp_t in inequalities */ 994 u8 __fa_dscp = inet_dscp_to_dsfield(fa->fa_dscp); 995 u8 __dscp = inet_dscp_to_dsfield(dscp); 996 997 if (fa->fa_slen < slen) 998 continue; 999 if (fa->fa_slen != slen) 1000 break; 1001 if (fa->tb_id > tb_id) 1002 continue; 1003 if (fa->tb_id != tb_id) 1004 break; 1005 if (find_first) 1006 return fa; 1007 if (__fa_dscp > __dscp) 1008 continue; 1009 if (fa->fa_info->fib_priority >= prio || __fa_dscp < __dscp) 1010 return fa; 1011 } 1012 1013 return NULL; 1014} 1015 1016static struct fib_alias * 1017fib_find_matching_alias(struct net *net, const struct fib_rt_info *fri) 1018{ 1019 u8 slen = KEYLENGTH - fri->dst_len; 1020 struct key_vector *l, *tp; 1021 struct fib_table *tb; 1022 struct fib_alias *fa; 1023 struct trie *t; 1024 1025 tb = fib_get_table(net, fri->tb_id); 1026 if (!tb) 1027 return NULL; 1028 1029 t = (struct trie *)tb->tb_data; 1030 l = fib_find_node(t, &tp, be32_to_cpu(fri->dst)); 1031 if (!l) 1032 return NULL; 1033 1034 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 1035 if (fa->fa_slen == slen && fa->tb_id == fri->tb_id && 1036 fa->fa_dscp == fri->dscp && fa->fa_info == fri->fi && 1037 fa->fa_type == fri->type) 1038 return fa; 1039 } 1040 1041 return NULL; 1042} 1043 1044void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri) 1045{ 1046 u8 fib_notify_on_flag_change; 1047 struct fib_alias *fa_match; 1048 struct sk_buff *skb; 1049 int err; 1050 1051 rcu_read_lock(); 1052 1053 fa_match = fib_find_matching_alias(net, fri); 1054 if (!fa_match) 1055 goto out; 1056 1057 /* These are paired with the WRITE_ONCE() happening in this function. 1058 * The reason is that we are only protected by RCU at this point. 1059 */ 1060 if (READ_ONCE(fa_match->offload) == fri->offload && 1061 READ_ONCE(fa_match->trap) == fri->trap && 1062 READ_ONCE(fa_match->offload_failed) == fri->offload_failed) 1063 goto out; 1064 1065 WRITE_ONCE(fa_match->offload, fri->offload); 1066 WRITE_ONCE(fa_match->trap, fri->trap); 1067 1068 fib_notify_on_flag_change = READ_ONCE(net->ipv4.sysctl_fib_notify_on_flag_change); 1069 1070 /* 2 means send notifications only if offload_failed was changed. */ 1071 if (fib_notify_on_flag_change == 2 && 1072 READ_ONCE(fa_match->offload_failed) == fri->offload_failed) 1073 goto out; 1074 1075 WRITE_ONCE(fa_match->offload_failed, fri->offload_failed); 1076 1077 if (!fib_notify_on_flag_change) 1078 goto out; 1079 1080 skb = nlmsg_new(fib_nlmsg_size(fa_match->fa_info), GFP_ATOMIC); 1081 if (!skb) { 1082 err = -ENOBUFS; 1083 goto errout; 1084 } 1085 1086 err = fib_dump_info(skb, 0, 0, RTM_NEWROUTE, fri, 0); 1087 if (err < 0) { 1088 /* -EMSGSIZE implies BUG in fib_nlmsg_size() */ 1089 WARN_ON(err == -EMSGSIZE); 1090 kfree_skb(skb); 1091 goto errout; 1092 } 1093 1094 rtnl_notify(skb, net, 0, RTNLGRP_IPV4_ROUTE, NULL, GFP_ATOMIC); 1095 goto out; 1096 1097errout: 1098 rtnl_set_sk_err(net, RTNLGRP_IPV4_ROUTE, err); 1099out: 1100 rcu_read_unlock(); 1101} 1102EXPORT_SYMBOL_GPL(fib_alias_hw_flags_set); 1103 1104static void trie_rebalance(struct trie *t, struct key_vector *tn) 1105{ 1106 while (!IS_TRIE(tn)) 1107 tn = resize(t, tn); 1108} 1109 1110static int fib_insert_node(struct trie *t, struct key_vector *tp, 1111 struct fib_alias *new, t_key key) 1112{ 1113 struct key_vector *n, *l; 1114 1115 l = leaf_new(key, new); 1116 if (!l) 1117 goto noleaf; 1118 1119 /* retrieve child from parent node */ 1120 n = get_child(tp, get_index(key, tp)); 1121 1122 /* Case 2: n is a LEAF or a TNODE and the key doesn't match. 1123 * 1124 * Add a new tnode here 1125 * first tnode need some special handling 1126 * leaves us in position for handling as case 3 1127 */ 1128 if (n) { 1129 struct key_vector *tn; 1130 1131 tn = tnode_new(key, __fls(key ^ n->key), 1); 1132 if (!tn) 1133 goto notnode; 1134 1135 /* initialize routes out of node */ 1136 NODE_INIT_PARENT(tn, tp); 1137 put_child(tn, get_index(key, tn) ^ 1, n); 1138 1139 /* start adding routes into the node */ 1140 put_child_root(tp, key, tn); 1141 node_set_parent(n, tn); 1142 1143 /* parent now has a NULL spot where the leaf can go */ 1144 tp = tn; 1145 } 1146 1147 /* Case 3: n is NULL, and will just insert a new leaf */ 1148 node_push_suffix(tp, new->fa_slen); 1149 NODE_INIT_PARENT(l, tp); 1150 put_child_root(tp, key, l); 1151 trie_rebalance(t, tp); 1152 1153 return 0; 1154notnode: 1155 node_free(l); 1156noleaf: 1157 return -ENOMEM; 1158} 1159 1160static int fib_insert_alias(struct trie *t, struct key_vector *tp, 1161 struct key_vector *l, struct fib_alias *new, 1162 struct fib_alias *fa, t_key key) 1163{ 1164 if (!l) 1165 return fib_insert_node(t, tp, new, key); 1166 1167 if (fa) { 1168 hlist_add_before_rcu(&new->fa_list, &fa->fa_list); 1169 } else { 1170 struct fib_alias *last; 1171 1172 hlist_for_each_entry(last, &l->leaf, fa_list) { 1173 if (new->fa_slen < last->fa_slen) 1174 break; 1175 if ((new->fa_slen == last->fa_slen) && 1176 (new->tb_id > last->tb_id)) 1177 break; 1178 fa = last; 1179 } 1180 1181 if (fa) 1182 hlist_add_behind_rcu(&new->fa_list, &fa->fa_list); 1183 else 1184 hlist_add_head_rcu(&new->fa_list, &l->leaf); 1185 } 1186 1187 /* if we added to the tail node then we need to update slen */ 1188 if (l->slen < new->fa_slen) { 1189 l->slen = new->fa_slen; 1190 node_push_suffix(tp, new->fa_slen); 1191 } 1192 1193 return 0; 1194} 1195 1196static bool fib_valid_key_len(u32 key, u8 plen, struct netlink_ext_ack *extack) 1197{ 1198 if (plen > KEYLENGTH) { 1199 NL_SET_ERR_MSG(extack, "Invalid prefix length"); 1200 return false; 1201 } 1202 1203 if ((plen < KEYLENGTH) && (key << plen)) { 1204 NL_SET_ERR_MSG(extack, 1205 "Invalid prefix for given prefix length"); 1206 return false; 1207 } 1208 1209 return true; 1210} 1211 1212static void fib_remove_alias(struct trie *t, struct key_vector *tp, 1213 struct key_vector *l, struct fib_alias *old); 1214 1215/* Caller must hold RTNL. */ 1216int fib_table_insert(struct net *net, struct fib_table *tb, 1217 struct fib_config *cfg, struct netlink_ext_ack *extack) 1218{ 1219 struct trie *t = (struct trie *)tb->tb_data; 1220 struct fib_alias *fa, *new_fa; 1221 struct key_vector *l, *tp; 1222 u16 nlflags = NLM_F_EXCL; 1223 struct fib_info *fi; 1224 u8 plen = cfg->fc_dst_len; 1225 u8 slen = KEYLENGTH - plen; 1226 dscp_t dscp; 1227 u32 key; 1228 int err; 1229 1230 key = ntohl(cfg->fc_dst); 1231 1232 if (!fib_valid_key_len(key, plen, extack)) 1233 return -EINVAL; 1234 1235 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen); 1236 1237 fi = fib_create_info(cfg, extack); 1238 if (IS_ERR(fi)) { 1239 err = PTR_ERR(fi); 1240 goto err; 1241 } 1242 1243 dscp = cfg->fc_dscp; 1244 l = fib_find_node(t, &tp, key); 1245 fa = l ? fib_find_alias(&l->leaf, slen, dscp, fi->fib_priority, 1246 tb->tb_id, false) : NULL; 1247 1248 /* Now fa, if non-NULL, points to the first fib alias 1249 * with the same keys [prefix,dscp,priority], if such key already 1250 * exists or to the node before which we will insert new one. 1251 * 1252 * If fa is NULL, we will need to allocate a new one and 1253 * insert to the tail of the section matching the suffix length 1254 * of the new alias. 1255 */ 1256 1257 if (fa && fa->fa_dscp == dscp && 1258 fa->fa_info->fib_priority == fi->fib_priority) { 1259 struct fib_alias *fa_first, *fa_match; 1260 1261 err = -EEXIST; 1262 if (cfg->fc_nlflags & NLM_F_EXCL) 1263 goto out; 1264 1265 nlflags &= ~NLM_F_EXCL; 1266 1267 /* We have 2 goals: 1268 * 1. Find exact match for type, scope, fib_info to avoid 1269 * duplicate routes 1270 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it 1271 */ 1272 fa_match = NULL; 1273 fa_first = fa; 1274 hlist_for_each_entry_from(fa, fa_list) { 1275 if ((fa->fa_slen != slen) || 1276 (fa->tb_id != tb->tb_id) || 1277 (fa->fa_dscp != dscp)) 1278 break; 1279 if (fa->fa_info->fib_priority != fi->fib_priority) 1280 break; 1281 if (fa->fa_type == cfg->fc_type && 1282 fa->fa_info == fi) { 1283 fa_match = fa; 1284 break; 1285 } 1286 } 1287 1288 if (cfg->fc_nlflags & NLM_F_REPLACE) { 1289 struct fib_info *fi_drop; 1290 u8 state; 1291 1292 nlflags |= NLM_F_REPLACE; 1293 fa = fa_first; 1294 if (fa_match) { 1295 if (fa == fa_match) 1296 err = 0; 1297 goto out; 1298 } 1299 err = -ENOBUFS; 1300 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1301 if (!new_fa) 1302 goto out; 1303 1304 fi_drop = fa->fa_info; 1305 new_fa->fa_dscp = fa->fa_dscp; 1306 new_fa->fa_info = fi; 1307 new_fa->fa_type = cfg->fc_type; 1308 state = fa->fa_state; 1309 new_fa->fa_state = state & ~FA_S_ACCESSED; 1310 new_fa->fa_slen = fa->fa_slen; 1311 new_fa->tb_id = tb->tb_id; 1312 new_fa->fa_default = -1; 1313 new_fa->offload = 0; 1314 new_fa->trap = 0; 1315 new_fa->offload_failed = 0; 1316 1317 hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list); 1318 1319 if (fib_find_alias(&l->leaf, fa->fa_slen, 0, 0, 1320 tb->tb_id, true) == new_fa) { 1321 enum fib_event_type fib_event; 1322 1323 fib_event = FIB_EVENT_ENTRY_REPLACE; 1324 err = call_fib_entry_notifiers(net, fib_event, 1325 key, plen, 1326 new_fa, extack); 1327 if (err) { 1328 hlist_replace_rcu(&new_fa->fa_list, 1329 &fa->fa_list); 1330 goto out_free_new_fa; 1331 } 1332 } 1333 1334 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, 1335 tb->tb_id, &cfg->fc_nlinfo, nlflags); 1336 1337 alias_free_mem_rcu(fa); 1338 1339 fib_release_info(fi_drop); 1340 if (state & FA_S_ACCESSED) 1341 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1342 1343 goto succeeded; 1344 } 1345 /* Error if we find a perfect match which 1346 * uses the same scope, type, and nexthop 1347 * information. 1348 */ 1349 if (fa_match) 1350 goto out; 1351 1352 if (cfg->fc_nlflags & NLM_F_APPEND) 1353 nlflags |= NLM_F_APPEND; 1354 else 1355 fa = fa_first; 1356 } 1357 err = -ENOENT; 1358 if (!(cfg->fc_nlflags & NLM_F_CREATE)) 1359 goto out; 1360 1361 nlflags |= NLM_F_CREATE; 1362 err = -ENOBUFS; 1363 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1364 if (!new_fa) 1365 goto out; 1366 1367 new_fa->fa_info = fi; 1368 new_fa->fa_dscp = dscp; 1369 new_fa->fa_type = cfg->fc_type; 1370 new_fa->fa_state = 0; 1371 new_fa->fa_slen = slen; 1372 new_fa->tb_id = tb->tb_id; 1373 new_fa->fa_default = -1; 1374 new_fa->offload = 0; 1375 new_fa->trap = 0; 1376 new_fa->offload_failed = 0; 1377 1378 /* Insert new entry to the list. */ 1379 err = fib_insert_alias(t, tp, l, new_fa, fa, key); 1380 if (err) 1381 goto out_free_new_fa; 1382 1383 /* The alias was already inserted, so the node must exist. */ 1384 l = l ? l : fib_find_node(t, &tp, key); 1385 if (WARN_ON_ONCE(!l)) { 1386 err = -ENOENT; 1387 goto out_free_new_fa; 1388 } 1389 1390 if (fib_find_alias(&l->leaf, new_fa->fa_slen, 0, 0, tb->tb_id, true) == 1391 new_fa) { 1392 enum fib_event_type fib_event; 1393 1394 fib_event = FIB_EVENT_ENTRY_REPLACE; 1395 err = call_fib_entry_notifiers(net, fib_event, key, plen, 1396 new_fa, extack); 1397 if (err) 1398 goto out_remove_new_fa; 1399 } 1400 1401 if (!plen) 1402 tb->tb_num_default++; 1403 1404 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1405 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id, 1406 &cfg->fc_nlinfo, nlflags); 1407succeeded: 1408 return 0; 1409 1410out_remove_new_fa: 1411 fib_remove_alias(t, tp, l, new_fa); 1412out_free_new_fa: 1413 kmem_cache_free(fn_alias_kmem, new_fa); 1414out: 1415 fib_release_info(fi); 1416err: 1417 return err; 1418} 1419 1420static inline t_key prefix_mismatch(t_key key, struct key_vector *n) 1421{ 1422 t_key prefix = n->key; 1423 1424 return (key ^ prefix) & (prefix | -prefix); 1425} 1426 1427bool fib_lookup_good_nhc(const struct fib_nh_common *nhc, int fib_flags, 1428 const struct flowi4 *flp) 1429{ 1430 if (nhc->nhc_flags & RTNH_F_DEAD) 1431 return false; 1432 1433 if (ip_ignore_linkdown(nhc->nhc_dev) && 1434 nhc->nhc_flags & RTNH_F_LINKDOWN && 1435 !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE)) 1436 return false; 1437 1438 if (flp->flowi4_oif && flp->flowi4_oif != nhc->nhc_oif) 1439 return false; 1440 1441 return true; 1442} 1443 1444/* should be called with rcu_read_lock */ 1445int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 1446 struct fib_result *res, int fib_flags) 1447{ 1448 struct trie *t = (struct trie *) tb->tb_data; 1449#ifdef CONFIG_IP_FIB_TRIE_STATS 1450 struct trie_use_stats __percpu *stats = t->stats; 1451#endif 1452 const t_key key = ntohl(flp->daddr); 1453 struct key_vector *n, *pn; 1454 struct fib_alias *fa; 1455 unsigned long index; 1456 t_key cindex; 1457 1458 pn = t->kv; 1459 cindex = 0; 1460 1461 n = get_child_rcu(pn, cindex); 1462 if (!n) { 1463 trace_fib_table_lookup(tb->tb_id, flp, NULL, -EAGAIN); 1464 return -EAGAIN; 1465 } 1466 1467#ifdef CONFIG_IP_FIB_TRIE_STATS 1468 this_cpu_inc(stats->gets); 1469#endif 1470 1471 /* Step 1: Travel to the longest prefix match in the trie */ 1472 for (;;) { 1473 index = get_cindex(key, n); 1474 1475 /* This bit of code is a bit tricky but it combines multiple 1476 * checks into a single check. The prefix consists of the 1477 * prefix plus zeros for the "bits" in the prefix. The index 1478 * is the difference between the key and this value. From 1479 * this we can actually derive several pieces of data. 1480 * if (index >= (1ul << bits)) 1481 * we have a mismatch in skip bits and failed 1482 * else 1483 * we know the value is cindex 1484 * 1485 * This check is safe even if bits == KEYLENGTH due to the 1486 * fact that we can only allocate a node with 32 bits if a 1487 * long is greater than 32 bits. 1488 */ 1489 if (index >= (1ul << n->bits)) 1490 break; 1491 1492 /* we have found a leaf. Prefixes have already been compared */ 1493 if (IS_LEAF(n)) 1494 goto found; 1495 1496 /* only record pn and cindex if we are going to be chopping 1497 * bits later. Otherwise we are just wasting cycles. 1498 */ 1499 if (n->slen > n->pos) { 1500 pn = n; 1501 cindex = index; 1502 } 1503 1504 n = get_child_rcu(n, index); 1505 if (unlikely(!n)) 1506 goto backtrace; 1507 } 1508 1509 /* Step 2: Sort out leaves and begin backtracing for longest prefix */ 1510 for (;;) { 1511 /* record the pointer where our next node pointer is stored */ 1512 struct key_vector __rcu **cptr = n->tnode; 1513 1514 /* This test verifies that none of the bits that differ 1515 * between the key and the prefix exist in the region of 1516 * the lsb and higher in the prefix. 1517 */ 1518 if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos)) 1519 goto backtrace; 1520 1521 /* exit out and process leaf */ 1522 if (unlikely(IS_LEAF(n))) 1523 break; 1524 1525 /* Don't bother recording parent info. Since we are in 1526 * prefix match mode we will have to come back to wherever 1527 * we started this traversal anyway 1528 */ 1529 1530 while ((n = rcu_dereference(*cptr)) == NULL) { 1531backtrace: 1532#ifdef CONFIG_IP_FIB_TRIE_STATS 1533 if (!n) 1534 this_cpu_inc(stats->null_node_hit); 1535#endif 1536 /* If we are at cindex 0 there are no more bits for 1537 * us to strip at this level so we must ascend back 1538 * up one level to see if there are any more bits to 1539 * be stripped there. 1540 */ 1541 while (!cindex) { 1542 t_key pkey = pn->key; 1543 1544 /* If we don't have a parent then there is 1545 * nothing for us to do as we do not have any 1546 * further nodes to parse. 1547 */ 1548 if (IS_TRIE(pn)) { 1549 trace_fib_table_lookup(tb->tb_id, flp, 1550 NULL, -EAGAIN); 1551 return -EAGAIN; 1552 } 1553#ifdef CONFIG_IP_FIB_TRIE_STATS 1554 this_cpu_inc(stats->backtrack); 1555#endif 1556 /* Get Child's index */ 1557 pn = node_parent_rcu(pn); 1558 cindex = get_index(pkey, pn); 1559 } 1560 1561 /* strip the least significant bit from the cindex */ 1562 cindex &= cindex - 1; 1563 1564 /* grab pointer for next child node */ 1565 cptr = &pn->tnode[cindex]; 1566 } 1567 } 1568 1569found: 1570 /* this line carries forward the xor from earlier in the function */ 1571 index = key ^ n->key; 1572 1573 /* Step 3: Process the leaf, if that fails fall back to backtracing */ 1574 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) { 1575 struct fib_info *fi = fa->fa_info; 1576 struct fib_nh_common *nhc; 1577 int nhsel, err; 1578 1579 if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) { 1580 if (index >= (1ul << fa->fa_slen)) 1581 continue; 1582 } 1583 if (fa->fa_dscp && 1584 inet_dscp_to_dsfield(fa->fa_dscp) != flp->flowi4_tos) 1585 continue; 1586 /* Paired with WRITE_ONCE() in fib_release_info() */ 1587 if (READ_ONCE(fi->fib_dead)) 1588 continue; 1589 if (fa->fa_info->fib_scope < flp->flowi4_scope) 1590 continue; 1591 fib_alias_accessed(fa); 1592 err = fib_props[fa->fa_type].error; 1593 if (unlikely(err < 0)) { 1594out_reject: 1595#ifdef CONFIG_IP_FIB_TRIE_STATS 1596 this_cpu_inc(stats->semantic_match_passed); 1597#endif 1598 trace_fib_table_lookup(tb->tb_id, flp, NULL, err); 1599 return err; 1600 } 1601 if (fi->fib_flags & RTNH_F_DEAD) 1602 continue; 1603 1604 if (unlikely(fi->nh)) { 1605 if (nexthop_is_blackhole(fi->nh)) { 1606 err = fib_props[RTN_BLACKHOLE].error; 1607 goto out_reject; 1608 } 1609 1610 nhc = nexthop_get_nhc_lookup(fi->nh, fib_flags, flp, 1611 &nhsel); 1612 if (nhc) 1613 goto set_result; 1614 goto miss; 1615 } 1616 1617 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 1618 nhc = fib_info_nhc(fi, nhsel); 1619 1620 if (!fib_lookup_good_nhc(nhc, fib_flags, flp)) 1621 continue; 1622set_result: 1623 if (!(fib_flags & FIB_LOOKUP_NOREF)) 1624 refcount_inc(&fi->fib_clntref); 1625 1626 res->prefix = htonl(n->key); 1627 res->prefixlen = KEYLENGTH - fa->fa_slen; 1628 res->nh_sel = nhsel; 1629 res->nhc = nhc; 1630 res->type = fa->fa_type; 1631 res->scope = fi->fib_scope; 1632 res->fi = fi; 1633 res->table = tb; 1634 res->fa_head = &n->leaf; 1635#ifdef CONFIG_IP_FIB_TRIE_STATS 1636 this_cpu_inc(stats->semantic_match_passed); 1637#endif 1638 trace_fib_table_lookup(tb->tb_id, flp, nhc, err); 1639 1640 return err; 1641 } 1642 } 1643miss: 1644#ifdef CONFIG_IP_FIB_TRIE_STATS 1645 this_cpu_inc(stats->semantic_match_miss); 1646#endif 1647 goto backtrace; 1648} 1649EXPORT_SYMBOL_GPL(fib_table_lookup); 1650 1651static void fib_remove_alias(struct trie *t, struct key_vector *tp, 1652 struct key_vector *l, struct fib_alias *old) 1653{ 1654 /* record the location of the previous list_info entry */ 1655 struct hlist_node **pprev = old->fa_list.pprev; 1656 struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next); 1657 1658 /* remove the fib_alias from the list */ 1659 hlist_del_rcu(&old->fa_list); 1660 1661 /* if we emptied the list this leaf will be freed and we can sort 1662 * out parent suffix lengths as a part of trie_rebalance 1663 */ 1664 if (hlist_empty(&l->leaf)) { 1665 if (tp->slen == l->slen) 1666 node_pull_suffix(tp, tp->pos); 1667 put_child_root(tp, l->key, NULL); 1668 node_free(l); 1669 trie_rebalance(t, tp); 1670 return; 1671 } 1672 1673 /* only access fa if it is pointing at the last valid hlist_node */ 1674 if (*pprev) 1675 return; 1676 1677 /* update the trie with the latest suffix length */ 1678 l->slen = fa->fa_slen; 1679 node_pull_suffix(tp, fa->fa_slen); 1680} 1681 1682static void fib_notify_alias_delete(struct net *net, u32 key, 1683 struct hlist_head *fah, 1684 struct fib_alias *fa_to_delete, 1685 struct netlink_ext_ack *extack) 1686{ 1687 struct fib_alias *fa_next, *fa_to_notify; 1688 u32 tb_id = fa_to_delete->tb_id; 1689 u8 slen = fa_to_delete->fa_slen; 1690 enum fib_event_type fib_event; 1691 1692 /* Do not notify if we do not care about the route. */ 1693 if (fib_find_alias(fah, slen, 0, 0, tb_id, true) != fa_to_delete) 1694 return; 1695 1696 /* Determine if the route should be replaced by the next route in the 1697 * list. 1698 */ 1699 fa_next = hlist_entry_safe(fa_to_delete->fa_list.next, 1700 struct fib_alias, fa_list); 1701 if (fa_next && fa_next->fa_slen == slen && fa_next->tb_id == tb_id) { 1702 fib_event = FIB_EVENT_ENTRY_REPLACE; 1703 fa_to_notify = fa_next; 1704 } else { 1705 fib_event = FIB_EVENT_ENTRY_DEL; 1706 fa_to_notify = fa_to_delete; 1707 } 1708 call_fib_entry_notifiers(net, fib_event, key, KEYLENGTH - slen, 1709 fa_to_notify, extack); 1710} 1711 1712/* Caller must hold RTNL. */ 1713int fib_table_delete(struct net *net, struct fib_table *tb, 1714 struct fib_config *cfg, struct netlink_ext_ack *extack) 1715{ 1716 struct trie *t = (struct trie *) tb->tb_data; 1717 struct fib_alias *fa, *fa_to_delete; 1718 struct key_vector *l, *tp; 1719 u8 plen = cfg->fc_dst_len; 1720 u8 slen = KEYLENGTH - plen; 1721 dscp_t dscp; 1722 u32 key; 1723 1724 key = ntohl(cfg->fc_dst); 1725 1726 if (!fib_valid_key_len(key, plen, extack)) 1727 return -EINVAL; 1728 1729 l = fib_find_node(t, &tp, key); 1730 if (!l) 1731 return -ESRCH; 1732 1733 dscp = cfg->fc_dscp; 1734 fa = fib_find_alias(&l->leaf, slen, dscp, 0, tb->tb_id, false); 1735 if (!fa) 1736 return -ESRCH; 1737 1738 pr_debug("Deleting %08x/%d dsfield=0x%02x t=%p\n", key, plen, 1739 inet_dscp_to_dsfield(dscp), t); 1740 1741 fa_to_delete = NULL; 1742 hlist_for_each_entry_from(fa, fa_list) { 1743 struct fib_info *fi = fa->fa_info; 1744 1745 if ((fa->fa_slen != slen) || 1746 (fa->tb_id != tb->tb_id) || 1747 (fa->fa_dscp != dscp)) 1748 break; 1749 1750 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) && 1751 (cfg->fc_scope == RT_SCOPE_NOWHERE || 1752 fa->fa_info->fib_scope == cfg->fc_scope) && 1753 (!cfg->fc_prefsrc || 1754 fi->fib_prefsrc == cfg->fc_prefsrc) && 1755 (!cfg->fc_protocol || 1756 fi->fib_protocol == cfg->fc_protocol) && 1757 fib_nh_match(net, cfg, fi, extack) == 0 && 1758 fib_metrics_match(cfg, fi)) { 1759 fa_to_delete = fa; 1760 break; 1761 } 1762 } 1763 1764 if (!fa_to_delete) 1765 return -ESRCH; 1766 1767 fib_notify_alias_delete(net, key, &l->leaf, fa_to_delete, extack); 1768 rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id, 1769 &cfg->fc_nlinfo, 0); 1770 1771 if (!plen) 1772 tb->tb_num_default--; 1773 1774 fib_remove_alias(t, tp, l, fa_to_delete); 1775 1776 if (fa_to_delete->fa_state & FA_S_ACCESSED) 1777 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1778 1779 fib_release_info(fa_to_delete->fa_info); 1780 alias_free_mem_rcu(fa_to_delete); 1781 return 0; 1782} 1783 1784/* Scan for the next leaf starting at the provided key value */ 1785static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key) 1786{ 1787 struct key_vector *pn, *n = *tn; 1788 unsigned long cindex; 1789 1790 /* this loop is meant to try and find the key in the trie */ 1791 do { 1792 /* record parent and next child index */ 1793 pn = n; 1794 cindex = (key > pn->key) ? get_index(key, pn) : 0; 1795 1796 if (cindex >> pn->bits) 1797 break; 1798 1799 /* descend into the next child */ 1800 n = get_child_rcu(pn, cindex++); 1801 if (!n) 1802 break; 1803 1804 /* guarantee forward progress on the keys */ 1805 if (IS_LEAF(n) && (n->key >= key)) 1806 goto found; 1807 } while (IS_TNODE(n)); 1808 1809 /* this loop will search for the next leaf with a greater key */ 1810 while (!IS_TRIE(pn)) { 1811 /* if we exhausted the parent node we will need to climb */ 1812 if (cindex >= (1ul << pn->bits)) { 1813 t_key pkey = pn->key; 1814 1815 pn = node_parent_rcu(pn); 1816 cindex = get_index(pkey, pn) + 1; 1817 continue; 1818 } 1819 1820 /* grab the next available node */ 1821 n = get_child_rcu(pn, cindex++); 1822 if (!n) 1823 continue; 1824 1825 /* no need to compare keys since we bumped the index */ 1826 if (IS_LEAF(n)) 1827 goto found; 1828 1829 /* Rescan start scanning in new node */ 1830 pn = n; 1831 cindex = 0; 1832 } 1833 1834 *tn = pn; 1835 return NULL; /* Root of trie */ 1836found: 1837 /* if we are at the limit for keys just return NULL for the tnode */ 1838 *tn = pn; 1839 return n; 1840} 1841 1842static void fib_trie_free(struct fib_table *tb) 1843{ 1844 struct trie *t = (struct trie *)tb->tb_data; 1845 struct key_vector *pn = t->kv; 1846 unsigned long cindex = 1; 1847 struct hlist_node *tmp; 1848 struct fib_alias *fa; 1849 1850 /* walk trie in reverse order and free everything */ 1851 for (;;) { 1852 struct key_vector *n; 1853 1854 if (!(cindex--)) { 1855 t_key pkey = pn->key; 1856 1857 if (IS_TRIE(pn)) 1858 break; 1859 1860 n = pn; 1861 pn = node_parent(pn); 1862 1863 /* drop emptied tnode */ 1864 put_child_root(pn, n->key, NULL); 1865 node_free(n); 1866 1867 cindex = get_index(pkey, pn); 1868 1869 continue; 1870 } 1871 1872 /* grab the next available node */ 1873 n = get_child(pn, cindex); 1874 if (!n) 1875 continue; 1876 1877 if (IS_TNODE(n)) { 1878 /* record pn and cindex for leaf walking */ 1879 pn = n; 1880 cindex = 1ul << n->bits; 1881 1882 continue; 1883 } 1884 1885 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 1886 hlist_del_rcu(&fa->fa_list); 1887 alias_free_mem_rcu(fa); 1888 } 1889 1890 put_child_root(pn, n->key, NULL); 1891 node_free(n); 1892 } 1893 1894#ifdef CONFIG_IP_FIB_TRIE_STATS 1895 free_percpu(t->stats); 1896#endif 1897 kfree(tb); 1898} 1899 1900struct fib_table *fib_trie_unmerge(struct fib_table *oldtb) 1901{ 1902 struct trie *ot = (struct trie *)oldtb->tb_data; 1903 struct key_vector *l, *tp = ot->kv; 1904 struct fib_table *local_tb; 1905 struct fib_alias *fa; 1906 struct trie *lt; 1907 t_key key = 0; 1908 1909 if (oldtb->tb_data == oldtb->__data) 1910 return oldtb; 1911 1912 local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL); 1913 if (!local_tb) 1914 return NULL; 1915 1916 lt = (struct trie *)local_tb->tb_data; 1917 1918 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 1919 struct key_vector *local_l = NULL, *local_tp; 1920 1921 hlist_for_each_entry(fa, &l->leaf, fa_list) { 1922 struct fib_alias *new_fa; 1923 1924 if (local_tb->tb_id != fa->tb_id) 1925 continue; 1926 1927 /* clone fa for new local table */ 1928 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1929 if (!new_fa) 1930 goto out; 1931 1932 memcpy(new_fa, fa, sizeof(*fa)); 1933 1934 /* insert clone into table */ 1935 if (!local_l) 1936 local_l = fib_find_node(lt, &local_tp, l->key); 1937 1938 if (fib_insert_alias(lt, local_tp, local_l, new_fa, 1939 NULL, l->key)) { 1940 kmem_cache_free(fn_alias_kmem, new_fa); 1941 goto out; 1942 } 1943 } 1944 1945 /* stop loop if key wrapped back to 0 */ 1946 key = l->key + 1; 1947 if (key < l->key) 1948 break; 1949 } 1950 1951 return local_tb; 1952out: 1953 fib_trie_free(local_tb); 1954 1955 return NULL; 1956} 1957 1958/* Caller must hold RTNL */ 1959void fib_table_flush_external(struct fib_table *tb) 1960{ 1961 struct trie *t = (struct trie *)tb->tb_data; 1962 struct key_vector *pn = t->kv; 1963 unsigned long cindex = 1; 1964 struct hlist_node *tmp; 1965 struct fib_alias *fa; 1966 1967 /* walk trie in reverse order */ 1968 for (;;) { 1969 unsigned char slen = 0; 1970 struct key_vector *n; 1971 1972 if (!(cindex--)) { 1973 t_key pkey = pn->key; 1974 1975 /* cannot resize the trie vector */ 1976 if (IS_TRIE(pn)) 1977 break; 1978 1979 /* update the suffix to address pulled leaves */ 1980 if (pn->slen > pn->pos) 1981 update_suffix(pn); 1982 1983 /* resize completed node */ 1984 pn = resize(t, pn); 1985 cindex = get_index(pkey, pn); 1986 1987 continue; 1988 } 1989 1990 /* grab the next available node */ 1991 n = get_child(pn, cindex); 1992 if (!n) 1993 continue; 1994 1995 if (IS_TNODE(n)) { 1996 /* record pn and cindex for leaf walking */ 1997 pn = n; 1998 cindex = 1ul << n->bits; 1999 2000 continue; 2001 } 2002 2003 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 2004 /* if alias was cloned to local then we just 2005 * need to remove the local copy from main 2006 */ 2007 if (tb->tb_id != fa->tb_id) { 2008 hlist_del_rcu(&fa->fa_list); 2009 alias_free_mem_rcu(fa); 2010 continue; 2011 } 2012 2013 /* record local slen */ 2014 slen = fa->fa_slen; 2015 } 2016 2017 /* update leaf slen */ 2018 n->slen = slen; 2019 2020 if (hlist_empty(&n->leaf)) { 2021 put_child_root(pn, n->key, NULL); 2022 node_free(n); 2023 } 2024 } 2025} 2026 2027/* Caller must hold RTNL. */ 2028int fib_table_flush(struct net *net, struct fib_table *tb, bool flush_all) 2029{ 2030 struct trie *t = (struct trie *)tb->tb_data; 2031 struct nl_info info = { .nl_net = net }; 2032 struct key_vector *pn = t->kv; 2033 unsigned long cindex = 1; 2034 struct hlist_node *tmp; 2035 struct fib_alias *fa; 2036 int found = 0; 2037 2038 /* walk trie in reverse order */ 2039 for (;;) { 2040 unsigned char slen = 0; 2041 struct key_vector *n; 2042 2043 if (!(cindex--)) { 2044 t_key pkey = pn->key; 2045 2046 /* cannot resize the trie vector */ 2047 if (IS_TRIE(pn)) 2048 break; 2049 2050 /* update the suffix to address pulled leaves */ 2051 if (pn->slen > pn->pos) 2052 update_suffix(pn); 2053 2054 /* resize completed node */ 2055 pn = resize(t, pn); 2056 cindex = get_index(pkey, pn); 2057 2058 continue; 2059 } 2060 2061 /* grab the next available node */ 2062 n = get_child(pn, cindex); 2063 if (!n) 2064 continue; 2065 2066 if (IS_TNODE(n)) { 2067 /* record pn and cindex for leaf walking */ 2068 pn = n; 2069 cindex = 1ul << n->bits; 2070 2071 continue; 2072 } 2073 2074 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 2075 struct fib_info *fi = fa->fa_info; 2076 2077 if (!fi || tb->tb_id != fa->tb_id || 2078 (!(fi->fib_flags & RTNH_F_DEAD) && 2079 !fib_props[fa->fa_type].error)) { 2080 slen = fa->fa_slen; 2081 continue; 2082 } 2083 2084 /* Do not flush error routes if network namespace is 2085 * not being dismantled 2086 */ 2087 if (!flush_all && fib_props[fa->fa_type].error) { 2088 slen = fa->fa_slen; 2089 continue; 2090 } 2091 2092 fib_notify_alias_delete(net, n->key, &n->leaf, fa, 2093 NULL); 2094 if (fi->pfsrc_removed) 2095 rtmsg_fib(RTM_DELROUTE, htonl(n->key), fa, 2096 KEYLENGTH - fa->fa_slen, tb->tb_id, &info, 0); 2097 hlist_del_rcu(&fa->fa_list); 2098 fib_release_info(fa->fa_info); 2099 alias_free_mem_rcu(fa); 2100 found++; 2101 } 2102 2103 /* update leaf slen */ 2104 n->slen = slen; 2105 2106 if (hlist_empty(&n->leaf)) { 2107 put_child_root(pn, n->key, NULL); 2108 node_free(n); 2109 } 2110 } 2111 2112 pr_debug("trie_flush found=%d\n", found); 2113 return found; 2114} 2115 2116/* derived from fib_trie_free */ 2117static void __fib_info_notify_update(struct net *net, struct fib_table *tb, 2118 struct nl_info *info) 2119{ 2120 struct trie *t = (struct trie *)tb->tb_data; 2121 struct key_vector *pn = t->kv; 2122 unsigned long cindex = 1; 2123 struct fib_alias *fa; 2124 2125 for (;;) { 2126 struct key_vector *n; 2127 2128 if (!(cindex--)) { 2129 t_key pkey = pn->key; 2130 2131 if (IS_TRIE(pn)) 2132 break; 2133 2134 pn = node_parent(pn); 2135 cindex = get_index(pkey, pn); 2136 continue; 2137 } 2138 2139 /* grab the next available node */ 2140 n = get_child(pn, cindex); 2141 if (!n) 2142 continue; 2143 2144 if (IS_TNODE(n)) { 2145 /* record pn and cindex for leaf walking */ 2146 pn = n; 2147 cindex = 1ul << n->bits; 2148 2149 continue; 2150 } 2151 2152 hlist_for_each_entry(fa, &n->leaf, fa_list) { 2153 struct fib_info *fi = fa->fa_info; 2154 2155 if (!fi || !fi->nh_updated || fa->tb_id != tb->tb_id) 2156 continue; 2157 2158 rtmsg_fib(RTM_NEWROUTE, htonl(n->key), fa, 2159 KEYLENGTH - fa->fa_slen, tb->tb_id, 2160 info, NLM_F_REPLACE); 2161 } 2162 } 2163} 2164 2165void fib_info_notify_update(struct net *net, struct nl_info *info) 2166{ 2167 unsigned int h; 2168 2169 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2170 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2171 struct fib_table *tb; 2172 2173 hlist_for_each_entry_rcu(tb, head, tb_hlist, 2174 lockdep_rtnl_is_held()) 2175 __fib_info_notify_update(net, tb, info); 2176 } 2177} 2178 2179static int fib_leaf_notify(struct key_vector *l, struct fib_table *tb, 2180 struct notifier_block *nb, 2181 struct netlink_ext_ack *extack) 2182{ 2183 struct fib_alias *fa; 2184 int last_slen = -1; 2185 int err; 2186 2187 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 2188 struct fib_info *fi = fa->fa_info; 2189 2190 if (!fi) 2191 continue; 2192 2193 /* local and main table can share the same trie, 2194 * so don't notify twice for the same entry. 2195 */ 2196 if (tb->tb_id != fa->tb_id) 2197 continue; 2198 2199 if (fa->fa_slen == last_slen) 2200 continue; 2201 2202 last_slen = fa->fa_slen; 2203 err = call_fib_entry_notifier(nb, FIB_EVENT_ENTRY_REPLACE, 2204 l->key, KEYLENGTH - fa->fa_slen, 2205 fa, extack); 2206 if (err) 2207 return err; 2208 } 2209 return 0; 2210} 2211 2212static int fib_table_notify(struct fib_table *tb, struct notifier_block *nb, 2213 struct netlink_ext_ack *extack) 2214{ 2215 struct trie *t = (struct trie *)tb->tb_data; 2216 struct key_vector *l, *tp = t->kv; 2217 t_key key = 0; 2218 int err; 2219 2220 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 2221 err = fib_leaf_notify(l, tb, nb, extack); 2222 if (err) 2223 return err; 2224 2225 key = l->key + 1; 2226 /* stop in case of wrap around */ 2227 if (key < l->key) 2228 break; 2229 } 2230 return 0; 2231} 2232 2233int fib_notify(struct net *net, struct notifier_block *nb, 2234 struct netlink_ext_ack *extack) 2235{ 2236 unsigned int h; 2237 int err; 2238 2239 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2240 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2241 struct fib_table *tb; 2242 2243 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2244 err = fib_table_notify(tb, nb, extack); 2245 if (err) 2246 return err; 2247 } 2248 } 2249 return 0; 2250} 2251 2252static void __trie_free_rcu(struct rcu_head *head) 2253{ 2254 struct fib_table *tb = container_of(head, struct fib_table, rcu); 2255#ifdef CONFIG_IP_FIB_TRIE_STATS 2256 struct trie *t = (struct trie *)tb->tb_data; 2257 2258 if (tb->tb_data == tb->__data) 2259 free_percpu(t->stats); 2260#endif /* CONFIG_IP_FIB_TRIE_STATS */ 2261 kfree(tb); 2262} 2263 2264void fib_free_table(struct fib_table *tb) 2265{ 2266 call_rcu(&tb->rcu, __trie_free_rcu); 2267} 2268 2269static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb, 2270 struct sk_buff *skb, struct netlink_callback *cb, 2271 struct fib_dump_filter *filter) 2272{ 2273 unsigned int flags = NLM_F_MULTI; 2274 __be32 xkey = htonl(l->key); 2275 int i, s_i, i_fa, s_fa, err; 2276 struct fib_alias *fa; 2277 2278 if (filter->filter_set || 2279 !filter->dump_exceptions || !filter->dump_routes) 2280 flags |= NLM_F_DUMP_FILTERED; 2281 2282 s_i = cb->args[4]; 2283 s_fa = cb->args[5]; 2284 i = 0; 2285 2286 /* rcu_read_lock is hold by caller */ 2287 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 2288 struct fib_info *fi = fa->fa_info; 2289 2290 if (i < s_i) 2291 goto next; 2292 2293 i_fa = 0; 2294 2295 if (tb->tb_id != fa->tb_id) 2296 goto next; 2297 2298 if (filter->filter_set) { 2299 if (filter->rt_type && fa->fa_type != filter->rt_type) 2300 goto next; 2301 2302 if ((filter->protocol && 2303 fi->fib_protocol != filter->protocol)) 2304 goto next; 2305 2306 if (filter->dev && 2307 !fib_info_nh_uses_dev(fi, filter->dev)) 2308 goto next; 2309 } 2310 2311 if (filter->dump_routes) { 2312 if (!s_fa) { 2313 struct fib_rt_info fri; 2314 2315 fri.fi = fi; 2316 fri.tb_id = tb->tb_id; 2317 fri.dst = xkey; 2318 fri.dst_len = KEYLENGTH - fa->fa_slen; 2319 fri.dscp = fa->fa_dscp; 2320 fri.type = fa->fa_type; 2321 fri.offload = READ_ONCE(fa->offload); 2322 fri.trap = READ_ONCE(fa->trap); 2323 fri.offload_failed = READ_ONCE(fa->offload_failed); 2324 err = fib_dump_info(skb, 2325 NETLINK_CB(cb->skb).portid, 2326 cb->nlh->nlmsg_seq, 2327 RTM_NEWROUTE, &fri, flags); 2328 if (err < 0) 2329 goto stop; 2330 } 2331 2332 i_fa++; 2333 } 2334 2335 if (filter->dump_exceptions) { 2336 err = fib_dump_info_fnhe(skb, cb, tb->tb_id, fi, 2337 &i_fa, s_fa, flags); 2338 if (err < 0) 2339 goto stop; 2340 } 2341 2342next: 2343 i++; 2344 } 2345 2346 cb->args[4] = i; 2347 return skb->len; 2348 2349stop: 2350 cb->args[4] = i; 2351 cb->args[5] = i_fa; 2352 return err; 2353} 2354 2355/* rcu_read_lock needs to be hold by caller from readside */ 2356int fib_table_dump(struct fib_table *tb, struct sk_buff *skb, 2357 struct netlink_callback *cb, struct fib_dump_filter *filter) 2358{ 2359 struct trie *t = (struct trie *)tb->tb_data; 2360 struct key_vector *l, *tp = t->kv; 2361 /* Dump starting at last key. 2362 * Note: 0.0.0.0/0 (ie default) is first key. 2363 */ 2364 int count = cb->args[2]; 2365 t_key key = cb->args[3]; 2366 2367 /* First time here, count and key are both always 0. Count > 0 2368 * and key == 0 means the dump has wrapped around and we are done. 2369 */ 2370 if (count && !key) 2371 return 0; 2372 2373 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 2374 int err; 2375 2376 err = fn_trie_dump_leaf(l, tb, skb, cb, filter); 2377 if (err < 0) { 2378 cb->args[3] = key; 2379 cb->args[2] = count; 2380 return err; 2381 } 2382 2383 ++count; 2384 key = l->key + 1; 2385 2386 memset(&cb->args[4], 0, 2387 sizeof(cb->args) - 4*sizeof(cb->args[0])); 2388 2389 /* stop loop if key wrapped back to 0 */ 2390 if (key < l->key) 2391 break; 2392 } 2393 2394 cb->args[3] = key; 2395 cb->args[2] = count; 2396 2397 return 0; 2398} 2399 2400void __init fib_trie_init(void) 2401{ 2402 fn_alias_kmem = kmem_cache_create("ip_fib_alias", 2403 sizeof(struct fib_alias), 2404 0, SLAB_PANIC | SLAB_ACCOUNT, NULL); 2405 2406 trie_leaf_kmem = kmem_cache_create("ip_fib_trie", 2407 LEAF_SIZE, 2408 0, SLAB_PANIC | SLAB_ACCOUNT, NULL); 2409} 2410 2411struct fib_table *fib_trie_table(u32 id, struct fib_table *alias) 2412{ 2413 struct fib_table *tb; 2414 struct trie *t; 2415 size_t sz = sizeof(*tb); 2416 2417 if (!alias) 2418 sz += sizeof(struct trie); 2419 2420 tb = kzalloc(sz, GFP_KERNEL); 2421 if (!tb) 2422 return NULL; 2423 2424 tb->tb_id = id; 2425 tb->tb_num_default = 0; 2426 tb->tb_data = (alias ? alias->__data : tb->__data); 2427 2428 if (alias) 2429 return tb; 2430 2431 t = (struct trie *) tb->tb_data; 2432 t->kv[0].pos = KEYLENGTH; 2433 t->kv[0].slen = KEYLENGTH; 2434#ifdef CONFIG_IP_FIB_TRIE_STATS 2435 t->stats = alloc_percpu(struct trie_use_stats); 2436 if (!t->stats) { 2437 kfree(tb); 2438 tb = NULL; 2439 } 2440#endif 2441 2442 return tb; 2443} 2444 2445#ifdef CONFIG_PROC_FS 2446/* Depth first Trie walk iterator */ 2447struct fib_trie_iter { 2448 struct seq_net_private p; 2449 struct fib_table *tb; 2450 struct key_vector *tnode; 2451 unsigned int index; 2452 unsigned int depth; 2453}; 2454 2455static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter) 2456{ 2457 unsigned long cindex = iter->index; 2458 struct key_vector *pn = iter->tnode; 2459 t_key pkey; 2460 2461 pr_debug("get_next iter={node=%p index=%d depth=%d}\n", 2462 iter->tnode, iter->index, iter->depth); 2463 2464 while (!IS_TRIE(pn)) { 2465 while (cindex < child_length(pn)) { 2466 struct key_vector *n = get_child_rcu(pn, cindex++); 2467 2468 if (!n) 2469 continue; 2470 2471 if (IS_LEAF(n)) { 2472 iter->tnode = pn; 2473 iter->index = cindex; 2474 } else { 2475 /* push down one level */ 2476 iter->tnode = n; 2477 iter->index = 0; 2478 ++iter->depth; 2479 } 2480 2481 return n; 2482 } 2483 2484 /* Current node exhausted, pop back up */ 2485 pkey = pn->key; 2486 pn = node_parent_rcu(pn); 2487 cindex = get_index(pkey, pn) + 1; 2488 --iter->depth; 2489 } 2490 2491 /* record root node so further searches know we are done */ 2492 iter->tnode = pn; 2493 iter->index = 0; 2494 2495 return NULL; 2496} 2497 2498static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter, 2499 struct trie *t) 2500{ 2501 struct key_vector *n, *pn; 2502 2503 if (!t) 2504 return NULL; 2505 2506 pn = t->kv; 2507 n = rcu_dereference(pn->tnode[0]); 2508 if (!n) 2509 return NULL; 2510 2511 if (IS_TNODE(n)) { 2512 iter->tnode = n; 2513 iter->index = 0; 2514 iter->depth = 1; 2515 } else { 2516 iter->tnode = pn; 2517 iter->index = 0; 2518 iter->depth = 0; 2519 } 2520 2521 return n; 2522} 2523 2524static void trie_collect_stats(struct trie *t, struct trie_stat *s) 2525{ 2526 struct key_vector *n; 2527 struct fib_trie_iter iter; 2528 2529 memset(s, 0, sizeof(*s)); 2530 2531 rcu_read_lock(); 2532 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) { 2533 if (IS_LEAF(n)) { 2534 struct fib_alias *fa; 2535 2536 s->leaves++; 2537 s->totdepth += iter.depth; 2538 if (iter.depth > s->maxdepth) 2539 s->maxdepth = iter.depth; 2540 2541 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) 2542 ++s->prefixes; 2543 } else { 2544 s->tnodes++; 2545 if (n->bits < MAX_STAT_DEPTH) 2546 s->nodesizes[n->bits]++; 2547 s->nullpointers += tn_info(n)->empty_children; 2548 } 2549 } 2550 rcu_read_unlock(); 2551} 2552 2553/* 2554 * This outputs /proc/net/fib_triestats 2555 */ 2556static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat) 2557{ 2558 unsigned int i, max, pointers, bytes, avdepth; 2559 2560 if (stat->leaves) 2561 avdepth = stat->totdepth*100 / stat->leaves; 2562 else 2563 avdepth = 0; 2564 2565 seq_printf(seq, "\tAver depth: %u.%02d\n", 2566 avdepth / 100, avdepth % 100); 2567 seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth); 2568 2569 seq_printf(seq, "\tLeaves: %u\n", stat->leaves); 2570 bytes = LEAF_SIZE * stat->leaves; 2571 2572 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes); 2573 bytes += sizeof(struct fib_alias) * stat->prefixes; 2574 2575 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes); 2576 bytes += TNODE_SIZE(0) * stat->tnodes; 2577 2578 max = MAX_STAT_DEPTH; 2579 while (max > 0 && stat->nodesizes[max-1] == 0) 2580 max--; 2581 2582 pointers = 0; 2583 for (i = 1; i < max; i++) 2584 if (stat->nodesizes[i] != 0) { 2585 seq_printf(seq, " %u: %u", i, stat->nodesizes[i]); 2586 pointers += (1<<i) * stat->nodesizes[i]; 2587 } 2588 seq_putc(seq, '\n'); 2589 seq_printf(seq, "\tPointers: %u\n", pointers); 2590 2591 bytes += sizeof(struct key_vector *) * pointers; 2592 seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers); 2593 seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024); 2594} 2595 2596#ifdef CONFIG_IP_FIB_TRIE_STATS 2597static void trie_show_usage(struct seq_file *seq, 2598 const struct trie_use_stats __percpu *stats) 2599{ 2600 struct trie_use_stats s = { 0 }; 2601 int cpu; 2602 2603 /* loop through all of the CPUs and gather up the stats */ 2604 for_each_possible_cpu(cpu) { 2605 const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu); 2606 2607 s.gets += pcpu->gets; 2608 s.backtrack += pcpu->backtrack; 2609 s.semantic_match_passed += pcpu->semantic_match_passed; 2610 s.semantic_match_miss += pcpu->semantic_match_miss; 2611 s.null_node_hit += pcpu->null_node_hit; 2612 s.resize_node_skipped += pcpu->resize_node_skipped; 2613 } 2614 2615 seq_printf(seq, "\nCounters:\n---------\n"); 2616 seq_printf(seq, "gets = %u\n", s.gets); 2617 seq_printf(seq, "backtracks = %u\n", s.backtrack); 2618 seq_printf(seq, "semantic match passed = %u\n", 2619 s.semantic_match_passed); 2620 seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss); 2621 seq_printf(seq, "null node hit= %u\n", s.null_node_hit); 2622 seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped); 2623} 2624#endif /* CONFIG_IP_FIB_TRIE_STATS */ 2625 2626static void fib_table_print(struct seq_file *seq, struct fib_table *tb) 2627{ 2628 if (tb->tb_id == RT_TABLE_LOCAL) 2629 seq_puts(seq, "Local:\n"); 2630 else if (tb->tb_id == RT_TABLE_MAIN) 2631 seq_puts(seq, "Main:\n"); 2632 else 2633 seq_printf(seq, "Id %d:\n", tb->tb_id); 2634} 2635 2636 2637static int fib_triestat_seq_show(struct seq_file *seq, void *v) 2638{ 2639 struct net *net = seq->private; 2640 unsigned int h; 2641 2642 seq_printf(seq, 2643 "Basic info: size of leaf:" 2644 " %zd bytes, size of tnode: %zd bytes.\n", 2645 LEAF_SIZE, TNODE_SIZE(0)); 2646 2647 rcu_read_lock(); 2648 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2649 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2650 struct fib_table *tb; 2651 2652 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2653 struct trie *t = (struct trie *) tb->tb_data; 2654 struct trie_stat stat; 2655 2656 if (!t) 2657 continue; 2658 2659 fib_table_print(seq, tb); 2660 2661 trie_collect_stats(t, &stat); 2662 trie_show_stats(seq, &stat); 2663#ifdef CONFIG_IP_FIB_TRIE_STATS 2664 trie_show_usage(seq, t->stats); 2665#endif 2666 } 2667 cond_resched_rcu(); 2668 } 2669 rcu_read_unlock(); 2670 2671 return 0; 2672} 2673 2674static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos) 2675{ 2676 struct fib_trie_iter *iter = seq->private; 2677 struct net *net = seq_file_net(seq); 2678 loff_t idx = 0; 2679 unsigned int h; 2680 2681 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2682 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2683 struct fib_table *tb; 2684 2685 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2686 struct key_vector *n; 2687 2688 for (n = fib_trie_get_first(iter, 2689 (struct trie *) tb->tb_data); 2690 n; n = fib_trie_get_next(iter)) 2691 if (pos == idx++) { 2692 iter->tb = tb; 2693 return n; 2694 } 2695 } 2696 } 2697 2698 return NULL; 2699} 2700 2701static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos) 2702 __acquires(RCU) 2703{ 2704 rcu_read_lock(); 2705 return fib_trie_get_idx(seq, *pos); 2706} 2707 2708static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2709{ 2710 struct fib_trie_iter *iter = seq->private; 2711 struct net *net = seq_file_net(seq); 2712 struct fib_table *tb = iter->tb; 2713 struct hlist_node *tb_node; 2714 unsigned int h; 2715 struct key_vector *n; 2716 2717 ++*pos; 2718 /* next node in same table */ 2719 n = fib_trie_get_next(iter); 2720 if (n) 2721 return n; 2722 2723 /* walk rest of this hash chain */ 2724 h = tb->tb_id & (FIB_TABLE_HASHSZ - 1); 2725 while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) { 2726 tb = hlist_entry(tb_node, struct fib_table, tb_hlist); 2727 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data); 2728 if (n) 2729 goto found; 2730 } 2731 2732 /* new hash chain */ 2733 while (++h < FIB_TABLE_HASHSZ) { 2734 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2735 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2736 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data); 2737 if (n) 2738 goto found; 2739 } 2740 } 2741 return NULL; 2742 2743found: 2744 iter->tb = tb; 2745 return n; 2746} 2747 2748static void fib_trie_seq_stop(struct seq_file *seq, void *v) 2749 __releases(RCU) 2750{ 2751 rcu_read_unlock(); 2752} 2753 2754static void seq_indent(struct seq_file *seq, int n) 2755{ 2756 while (n-- > 0) 2757 seq_puts(seq, " "); 2758} 2759 2760static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s) 2761{ 2762 switch (s) { 2763 case RT_SCOPE_UNIVERSE: return "universe"; 2764 case RT_SCOPE_SITE: return "site"; 2765 case RT_SCOPE_LINK: return "link"; 2766 case RT_SCOPE_HOST: return "host"; 2767 case RT_SCOPE_NOWHERE: return "nowhere"; 2768 default: 2769 snprintf(buf, len, "scope=%d", s); 2770 return buf; 2771 } 2772} 2773 2774static const char *const rtn_type_names[__RTN_MAX] = { 2775 [RTN_UNSPEC] = "UNSPEC", 2776 [RTN_UNICAST] = "UNICAST", 2777 [RTN_LOCAL] = "LOCAL", 2778 [RTN_BROADCAST] = "BROADCAST", 2779 [RTN_ANYCAST] = "ANYCAST", 2780 [RTN_MULTICAST] = "MULTICAST", 2781 [RTN_BLACKHOLE] = "BLACKHOLE", 2782 [RTN_UNREACHABLE] = "UNREACHABLE", 2783 [RTN_PROHIBIT] = "PROHIBIT", 2784 [RTN_THROW] = "THROW", 2785 [RTN_NAT] = "NAT", 2786 [RTN_XRESOLVE] = "XRESOLVE", 2787}; 2788 2789static inline const char *rtn_type(char *buf, size_t len, unsigned int t) 2790{ 2791 if (t < __RTN_MAX && rtn_type_names[t]) 2792 return rtn_type_names[t]; 2793 snprintf(buf, len, "type %u", t); 2794 return buf; 2795} 2796 2797/* Pretty print the trie */ 2798static int fib_trie_seq_show(struct seq_file *seq, void *v) 2799{ 2800 const struct fib_trie_iter *iter = seq->private; 2801 struct key_vector *n = v; 2802 2803 if (IS_TRIE(node_parent_rcu(n))) 2804 fib_table_print(seq, iter->tb); 2805 2806 if (IS_TNODE(n)) { 2807 __be32 prf = htonl(n->key); 2808 2809 seq_indent(seq, iter->depth-1); 2810 seq_printf(seq, " +-- %pI4/%zu %u %u %u\n", 2811 &prf, KEYLENGTH - n->pos - n->bits, n->bits, 2812 tn_info(n)->full_children, 2813 tn_info(n)->empty_children); 2814 } else { 2815 __be32 val = htonl(n->key); 2816 struct fib_alias *fa; 2817 2818 seq_indent(seq, iter->depth); 2819 seq_printf(seq, " |-- %pI4\n", &val); 2820 2821 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) { 2822 char buf1[32], buf2[32]; 2823 2824 seq_indent(seq, iter->depth + 1); 2825 seq_printf(seq, " /%zu %s %s", 2826 KEYLENGTH - fa->fa_slen, 2827 rtn_scope(buf1, sizeof(buf1), 2828 fa->fa_info->fib_scope), 2829 rtn_type(buf2, sizeof(buf2), 2830 fa->fa_type)); 2831 if (fa->fa_dscp) 2832 seq_printf(seq, " tos=%d", 2833 inet_dscp_to_dsfield(fa->fa_dscp)); 2834 seq_putc(seq, '\n'); 2835 } 2836 } 2837 2838 return 0; 2839} 2840 2841static const struct seq_operations fib_trie_seq_ops = { 2842 .start = fib_trie_seq_start, 2843 .next = fib_trie_seq_next, 2844 .stop = fib_trie_seq_stop, 2845 .show = fib_trie_seq_show, 2846}; 2847 2848struct fib_route_iter { 2849 struct seq_net_private p; 2850 struct fib_table *main_tb; 2851 struct key_vector *tnode; 2852 loff_t pos; 2853 t_key key; 2854}; 2855 2856static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter, 2857 loff_t pos) 2858{ 2859 struct key_vector *l, **tp = &iter->tnode; 2860 t_key key; 2861 2862 /* use cached location of previously found key */ 2863 if (iter->pos > 0 && pos >= iter->pos) { 2864 key = iter->key; 2865 } else { 2866 iter->pos = 1; 2867 key = 0; 2868 } 2869 2870 pos -= iter->pos; 2871 2872 while ((l = leaf_walk_rcu(tp, key)) && (pos-- > 0)) { 2873 key = l->key + 1; 2874 iter->pos++; 2875 l = NULL; 2876 2877 /* handle unlikely case of a key wrap */ 2878 if (!key) 2879 break; 2880 } 2881 2882 if (l) 2883 iter->key = l->key; /* remember it */ 2884 else 2885 iter->pos = 0; /* forget it */ 2886 2887 return l; 2888} 2889 2890static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos) 2891 __acquires(RCU) 2892{ 2893 struct fib_route_iter *iter = seq->private; 2894 struct fib_table *tb; 2895 struct trie *t; 2896 2897 rcu_read_lock(); 2898 2899 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN); 2900 if (!tb) 2901 return NULL; 2902 2903 iter->main_tb = tb; 2904 t = (struct trie *)tb->tb_data; 2905 iter->tnode = t->kv; 2906 2907 if (*pos != 0) 2908 return fib_route_get_idx(iter, *pos); 2909 2910 iter->pos = 0; 2911 iter->key = KEY_MAX; 2912 2913 return SEQ_START_TOKEN; 2914} 2915 2916static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2917{ 2918 struct fib_route_iter *iter = seq->private; 2919 struct key_vector *l = NULL; 2920 t_key key = iter->key + 1; 2921 2922 ++*pos; 2923 2924 /* only allow key of 0 for start of sequence */ 2925 if ((v == SEQ_START_TOKEN) || key) 2926 l = leaf_walk_rcu(&iter->tnode, key); 2927 2928 if (l) { 2929 iter->key = l->key; 2930 iter->pos++; 2931 } else { 2932 iter->pos = 0; 2933 } 2934 2935 return l; 2936} 2937 2938static void fib_route_seq_stop(struct seq_file *seq, void *v) 2939 __releases(RCU) 2940{ 2941 rcu_read_unlock(); 2942} 2943 2944static unsigned int fib_flag_trans(int type, __be32 mask, struct fib_info *fi) 2945{ 2946 unsigned int flags = 0; 2947 2948 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT) 2949 flags = RTF_REJECT; 2950 if (fi) { 2951 const struct fib_nh_common *nhc = fib_info_nhc(fi, 0); 2952 2953 if (nhc->nhc_gw.ipv4) 2954 flags |= RTF_GATEWAY; 2955 } 2956 if (mask == htonl(0xFFFFFFFF)) 2957 flags |= RTF_HOST; 2958 flags |= RTF_UP; 2959 return flags; 2960} 2961 2962/* 2963 * This outputs /proc/net/route. 2964 * The format of the file is not supposed to be changed 2965 * and needs to be same as fib_hash output to avoid breaking 2966 * legacy utilities 2967 */ 2968static int fib_route_seq_show(struct seq_file *seq, void *v) 2969{ 2970 struct fib_route_iter *iter = seq->private; 2971 struct fib_table *tb = iter->main_tb; 2972 struct fib_alias *fa; 2973 struct key_vector *l = v; 2974 __be32 prefix; 2975 2976 if (v == SEQ_START_TOKEN) { 2977 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway " 2978 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU" 2979 "\tWindow\tIRTT"); 2980 return 0; 2981 } 2982 2983 prefix = htonl(l->key); 2984 2985 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 2986 struct fib_info *fi = fa->fa_info; 2987 __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen); 2988 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi); 2989 2990 if ((fa->fa_type == RTN_BROADCAST) || 2991 (fa->fa_type == RTN_MULTICAST)) 2992 continue; 2993 2994 if (fa->tb_id != tb->tb_id) 2995 continue; 2996 2997 seq_setwidth(seq, 127); 2998 2999 if (fi) { 3000 struct fib_nh_common *nhc = fib_info_nhc(fi, 0); 3001 __be32 gw = 0; 3002 3003 if (nhc->nhc_gw_family == AF_INET) 3004 gw = nhc->nhc_gw.ipv4; 3005 3006 seq_printf(seq, 3007 "%s\t%08X\t%08X\t%04X\t%d\t%u\t" 3008 "%d\t%08X\t%d\t%u\t%u", 3009 nhc->nhc_dev ? nhc->nhc_dev->name : "*", 3010 prefix, gw, flags, 0, 0, 3011 fi->fib_priority, 3012 mask, 3013 (fi->fib_advmss ? 3014 fi->fib_advmss + 40 : 0), 3015 fi->fib_window, 3016 fi->fib_rtt >> 3); 3017 } else { 3018 seq_printf(seq, 3019 "*\t%08X\t%08X\t%04X\t%d\t%u\t" 3020 "%d\t%08X\t%d\t%u\t%u", 3021 prefix, 0, flags, 0, 0, 0, 3022 mask, 0, 0, 0); 3023 } 3024 seq_pad(seq, '\n'); 3025 } 3026 3027 return 0; 3028} 3029 3030static const struct seq_operations fib_route_seq_ops = { 3031 .start = fib_route_seq_start, 3032 .next = fib_route_seq_next, 3033 .stop = fib_route_seq_stop, 3034 .show = fib_route_seq_show, 3035}; 3036 3037int __net_init fib_proc_init(struct net *net) 3038{ 3039 if (!proc_create_net("fib_trie", 0444, net->proc_net, &fib_trie_seq_ops, 3040 sizeof(struct fib_trie_iter))) 3041 goto out1; 3042 3043 if (!proc_create_net_single("fib_triestat", 0444, net->proc_net, 3044 fib_triestat_seq_show, NULL)) 3045 goto out2; 3046 3047 if (!proc_create_net("route", 0444, net->proc_net, &fib_route_seq_ops, 3048 sizeof(struct fib_route_iter))) 3049 goto out3; 3050 3051 return 0; 3052 3053out3: 3054 remove_proc_entry("fib_triestat", net->proc_net); 3055out2: 3056 remove_proc_entry("fib_trie", net->proc_net); 3057out1: 3058 return -ENOMEM; 3059} 3060 3061void __net_exit fib_proc_exit(struct net *net) 3062{ 3063 remove_proc_entry("fib_trie", net->proc_net); 3064 remove_proc_entry("fib_triestat", net->proc_net); 3065 remove_proc_entry("route", net->proc_net); 3066} 3067 3068#endif /* CONFIG_PROC_FS */ 3069