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/skbuff.h> 56#include <linux/netlink.h> 57#include <linux/init.h> 58#include <linux/list.h> 59#include <linux/slab.h> 60#include <linux/export.h> 61#include <linux/vmalloc.h> 62#include <linux/notifier.h> 63#include <net/net_namespace.h> 64#include <net/ip.h> 65#include <net/protocol.h> 66#include <net/route.h> 67#include <net/tcp.h> 68#include <net/sock.h> 69#include <net/ip_fib.h> 70#include <net/fib_notifier.h> 71#include <trace/events/fib.h> 72#include "fib_lookup.h" 73 74static int call_fib_entry_notifier(struct notifier_block *nb, 75 enum fib_event_type event_type, u32 dst, 76 int dst_len, struct fib_alias *fa, 77 struct netlink_ext_ack *extack) 78{ 79 struct fib_entry_notifier_info info = { 80 .info.extack = extack, 81 .dst = dst, 82 .dst_len = dst_len, 83 .fi = fa->fa_info, 84 .tos = fa->fa_tos, 85 .type = fa->fa_type, 86 .tb_id = fa->tb_id, 87 }; 88 return call_fib4_notifier(nb, event_type, &info.info); 89} 90 91static int call_fib_entry_notifiers(struct net *net, 92 enum fib_event_type event_type, u32 dst, 93 int dst_len, struct fib_alias *fa, 94 struct netlink_ext_ack *extack) 95{ 96 struct fib_entry_notifier_info info = { 97 .info.extack = extack, 98 .dst = dst, 99 .dst_len = dst_len, 100 .fi = fa->fa_info, 101 .tos = fa->fa_tos, 102 .type = fa->fa_type, 103 .tb_id = fa->tb_id, 104 }; 105 return call_fib4_notifiers(net, event_type, &info.info); 106} 107 108#define MAX_STAT_DEPTH 32 109 110#define KEYLENGTH (8*sizeof(t_key)) 111#define KEY_MAX ((t_key)~0) 112 113typedef unsigned int t_key; 114 115#define IS_TRIE(n) ((n)->pos >= KEYLENGTH) 116#define IS_TNODE(n) ((n)->bits) 117#define IS_LEAF(n) (!(n)->bits) 118 119struct key_vector { 120 t_key key; 121 unsigned char pos; /* 2log(KEYLENGTH) bits needed */ 122 unsigned char bits; /* 2log(KEYLENGTH) bits needed */ 123 unsigned char slen; 124 union { 125 /* This list pointer if valid if (pos | bits) == 0 (LEAF) */ 126 struct hlist_head leaf; 127 /* This array is valid if (pos | bits) > 0 (TNODE) */ 128 struct key_vector __rcu *tnode[0]; 129 }; 130}; 131 132struct tnode { 133 struct rcu_head rcu; 134 t_key empty_children; /* KEYLENGTH bits needed */ 135 t_key full_children; /* KEYLENGTH bits needed */ 136 struct key_vector __rcu *parent; 137 struct key_vector kv[1]; 138#define tn_bits kv[0].bits 139}; 140 141#define TNODE_SIZE(n) offsetof(struct tnode, kv[0].tnode[n]) 142#define LEAF_SIZE TNODE_SIZE(1) 143 144#ifdef CONFIG_IP_FIB_TRIE_STATS 145struct trie_use_stats { 146 unsigned int gets; 147 unsigned int backtrack; 148 unsigned int semantic_match_passed; 149 unsigned int semantic_match_miss; 150 unsigned int null_node_hit; 151 unsigned int resize_node_skipped; 152}; 153#endif 154 155struct trie_stat { 156 unsigned int totdepth; 157 unsigned int maxdepth; 158 unsigned int tnodes; 159 unsigned int leaves; 160 unsigned int nullpointers; 161 unsigned int prefixes; 162 unsigned int nodesizes[MAX_STAT_DEPTH]; 163}; 164 165struct trie { 166 struct key_vector kv[1]; 167#ifdef CONFIG_IP_FIB_TRIE_STATS 168 struct trie_use_stats __percpu *stats; 169#endif 170}; 171 172static struct key_vector *resize(struct trie *t, struct key_vector *tn); 173static unsigned int tnode_free_size; 174 175/* 176 * synchronize_rcu after call_rcu for outstanding dirty memory; it should be 177 * especially useful before resizing the root node with PREEMPT_NONE configs; 178 * the value was obtained experimentally, aiming to avoid visible slowdown. 179 */ 180unsigned int sysctl_fib_sync_mem = 512 * 1024; 181unsigned int sysctl_fib_sync_mem_min = 64 * 1024; 182unsigned int sysctl_fib_sync_mem_max = 64 * 1024 * 1024; 183 184static struct kmem_cache *fn_alias_kmem __ro_after_init; 185static struct kmem_cache *trie_leaf_kmem __ro_after_init; 186 187static inline struct tnode *tn_info(struct key_vector *kv) 188{ 189 return container_of(kv, struct tnode, kv[0]); 190} 191 192/* caller must hold RTNL */ 193#define node_parent(tn) rtnl_dereference(tn_info(tn)->parent) 194#define get_child(tn, i) rtnl_dereference((tn)->tnode[i]) 195 196/* caller must hold RCU read lock or RTNL */ 197#define node_parent_rcu(tn) rcu_dereference_rtnl(tn_info(tn)->parent) 198#define get_child_rcu(tn, i) rcu_dereference_rtnl((tn)->tnode[i]) 199 200/* wrapper for rcu_assign_pointer */ 201static inline void node_set_parent(struct key_vector *n, struct key_vector *tp) 202{ 203 if (n) 204 rcu_assign_pointer(tn_info(n)->parent, tp); 205} 206 207#define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER(tn_info(n)->parent, p) 208 209/* This provides us with the number of children in this node, in the case of a 210 * leaf this will return 0 meaning none of the children are accessible. 211 */ 212static inline unsigned long child_length(const struct key_vector *tn) 213{ 214 return (1ul << tn->bits) & ~(1ul); 215} 216 217#define get_cindex(key, kv) (((key) ^ (kv)->key) >> (kv)->pos) 218 219static inline unsigned long get_index(t_key key, struct key_vector *kv) 220{ 221 unsigned long index = key ^ kv->key; 222 223 if ((BITS_PER_LONG <= KEYLENGTH) && (KEYLENGTH == kv->pos)) 224 return 0; 225 226 return index >> kv->pos; 227} 228 229/* To understand this stuff, an understanding of keys and all their bits is 230 * necessary. Every node in the trie has a key associated with it, but not 231 * all of the bits in that key are significant. 232 * 233 * Consider a node 'n' and its parent 'tp'. 234 * 235 * If n is a leaf, every bit in its key is significant. Its presence is 236 * necessitated by path compression, since during a tree traversal (when 237 * searching for a leaf - unless we are doing an insertion) we will completely 238 * ignore all skipped bits we encounter. Thus we need to verify, at the end of 239 * a potentially successful search, that we have indeed been walking the 240 * correct key path. 241 * 242 * Note that we can never "miss" the correct key in the tree if present by 243 * following the wrong path. Path compression ensures that segments of the key 244 * that are the same for all keys with a given prefix are skipped, but the 245 * skipped part *is* identical for each node in the subtrie below the skipped 246 * bit! trie_insert() in this implementation takes care of that. 247 * 248 * if n is an internal node - a 'tnode' here, the various parts of its key 249 * have many different meanings. 250 * 251 * Example: 252 * _________________________________________________________________ 253 * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C | 254 * ----------------------------------------------------------------- 255 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 256 * 257 * _________________________________________________________________ 258 * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u | 259 * ----------------------------------------------------------------- 260 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 261 * 262 * tp->pos = 22 263 * tp->bits = 3 264 * n->pos = 13 265 * n->bits = 4 266 * 267 * First, let's just ignore the bits that come before the parent tp, that is 268 * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this 269 * point we do not use them for anything. 270 * 271 * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the 272 * index into the parent's child array. That is, they will be used to find 273 * 'n' among tp's children. 274 * 275 * The bits from (n->pos + n->bits) to (tp->pos - 1) - "S" - are skipped bits 276 * for the node n. 277 * 278 * All the bits we have seen so far are significant to the node n. The rest 279 * of the bits are really not needed or indeed known in n->key. 280 * 281 * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into 282 * n's child array, and will of course be different for each child. 283 * 284 * The rest of the bits, from 0 to (n->pos -1) - "u" - are completely unknown 285 * at this point. 286 */ 287 288static const int halve_threshold = 25; 289static const int inflate_threshold = 50; 290static const int halve_threshold_root = 15; 291static const int inflate_threshold_root = 30; 292 293static void __alias_free_mem(struct rcu_head *head) 294{ 295 struct fib_alias *fa = container_of(head, struct fib_alias, rcu); 296 kmem_cache_free(fn_alias_kmem, fa); 297} 298 299static inline void alias_free_mem_rcu(struct fib_alias *fa) 300{ 301 call_rcu(&fa->rcu, __alias_free_mem); 302} 303 304#define TNODE_VMALLOC_MAX \ 305 ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *)) 306 307static void __node_free_rcu(struct rcu_head *head) 308{ 309 struct tnode *n = container_of(head, struct tnode, rcu); 310 311 if (!n->tn_bits) 312 kmem_cache_free(trie_leaf_kmem, n); 313 else 314 kvfree(n); 315} 316 317#define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu) 318 319static struct tnode *tnode_alloc(int bits) 320{ 321 size_t size; 322 323 /* verify bits is within bounds */ 324 if (bits > TNODE_VMALLOC_MAX) 325 return NULL; 326 327 /* determine size and verify it is non-zero and didn't overflow */ 328 size = TNODE_SIZE(1ul << bits); 329 330 if (size <= PAGE_SIZE) 331 return kzalloc(size, GFP_KERNEL); 332 else 333 return vzalloc(size); 334} 335 336static inline void empty_child_inc(struct key_vector *n) 337{ 338 tn_info(n)->empty_children++; 339 340 if (!tn_info(n)->empty_children) 341 tn_info(n)->full_children++; 342} 343 344static inline void empty_child_dec(struct key_vector *n) 345{ 346 if (!tn_info(n)->empty_children) 347 tn_info(n)->full_children--; 348 349 tn_info(n)->empty_children--; 350} 351 352static struct key_vector *leaf_new(t_key key, struct fib_alias *fa) 353{ 354 struct key_vector *l; 355 struct tnode *kv; 356 357 kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL); 358 if (!kv) 359 return NULL; 360 361 /* initialize key vector */ 362 l = kv->kv; 363 l->key = key; 364 l->pos = 0; 365 l->bits = 0; 366 l->slen = fa->fa_slen; 367 368 /* link leaf to fib alias */ 369 INIT_HLIST_HEAD(&l->leaf); 370 hlist_add_head(&fa->fa_list, &l->leaf); 371 372 return l; 373} 374 375static struct key_vector *tnode_new(t_key key, int pos, int bits) 376{ 377 unsigned int shift = pos + bits; 378 struct key_vector *tn; 379 struct tnode *tnode; 380 381 /* verify bits and pos their msb bits clear and values are valid */ 382 BUG_ON(!bits || (shift > KEYLENGTH)); 383 384 tnode = tnode_alloc(bits); 385 if (!tnode) 386 return NULL; 387 388 pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0), 389 sizeof(struct key_vector *) << bits); 390 391 if (bits == KEYLENGTH) 392 tnode->full_children = 1; 393 else 394 tnode->empty_children = 1ul << bits; 395 396 tn = tnode->kv; 397 tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0; 398 tn->pos = pos; 399 tn->bits = bits; 400 tn->slen = pos; 401 402 return tn; 403} 404 405/* Check whether a tnode 'n' is "full", i.e. it is an internal node 406 * and no bits are skipped. See discussion in dyntree paper p. 6 407 */ 408static inline int tnode_full(struct key_vector *tn, struct key_vector *n) 409{ 410 return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n); 411} 412 413/* Add a child at position i overwriting the old value. 414 * Update the value of full_children and empty_children. 415 */ 416static void put_child(struct key_vector *tn, unsigned long i, 417 struct key_vector *n) 418{ 419 struct key_vector *chi = get_child(tn, i); 420 int isfull, wasfull; 421 422 BUG_ON(i >= child_length(tn)); 423 424 /* update emptyChildren, overflow into fullChildren */ 425 if (!n && chi) 426 empty_child_inc(tn); 427 if (n && !chi) 428 empty_child_dec(tn); 429 430 /* update fullChildren */ 431 wasfull = tnode_full(tn, chi); 432 isfull = tnode_full(tn, n); 433 434 if (wasfull && !isfull) 435 tn_info(tn)->full_children--; 436 else if (!wasfull && isfull) 437 tn_info(tn)->full_children++; 438 439 if (n && (tn->slen < n->slen)) 440 tn->slen = n->slen; 441 442 rcu_assign_pointer(tn->tnode[i], n); 443} 444 445static void update_children(struct key_vector *tn) 446{ 447 unsigned long i; 448 449 /* update all of the child parent pointers */ 450 for (i = child_length(tn); i;) { 451 struct key_vector *inode = get_child(tn, --i); 452 453 if (!inode) 454 continue; 455 456 /* Either update the children of a tnode that 457 * already belongs to us or update the child 458 * to point to ourselves. 459 */ 460 if (node_parent(inode) == tn) 461 update_children(inode); 462 else 463 node_set_parent(inode, tn); 464 } 465} 466 467static inline void put_child_root(struct key_vector *tp, t_key key, 468 struct key_vector *n) 469{ 470 if (IS_TRIE(tp)) 471 rcu_assign_pointer(tp->tnode[0], n); 472 else 473 put_child(tp, get_index(key, tp), n); 474} 475 476static inline void tnode_free_init(struct key_vector *tn) 477{ 478 tn_info(tn)->rcu.next = NULL; 479} 480 481static inline void tnode_free_append(struct key_vector *tn, 482 struct key_vector *n) 483{ 484 tn_info(n)->rcu.next = tn_info(tn)->rcu.next; 485 tn_info(tn)->rcu.next = &tn_info(n)->rcu; 486} 487 488static void tnode_free(struct key_vector *tn) 489{ 490 struct callback_head *head = &tn_info(tn)->rcu; 491 492 while (head) { 493 head = head->next; 494 tnode_free_size += TNODE_SIZE(1ul << tn->bits); 495 node_free(tn); 496 497 tn = container_of(head, struct tnode, rcu)->kv; 498 } 499 500 if (tnode_free_size >= READ_ONCE(sysctl_fib_sync_mem)) { 501 tnode_free_size = 0; 502 synchronize_rcu(); 503 } 504} 505 506static struct key_vector *replace(struct trie *t, 507 struct key_vector *oldtnode, 508 struct key_vector *tn) 509{ 510 struct key_vector *tp = node_parent(oldtnode); 511 unsigned long i; 512 513 /* setup the parent pointer out of and back into this node */ 514 NODE_INIT_PARENT(tn, tp); 515 put_child_root(tp, tn->key, tn); 516 517 /* update all of the child parent pointers */ 518 update_children(tn); 519 520 /* all pointers should be clean so we are done */ 521 tnode_free(oldtnode); 522 523 /* resize children now that oldtnode is freed */ 524 for (i = child_length(tn); i;) { 525 struct key_vector *inode = get_child(tn, --i); 526 527 /* resize child node */ 528 if (tnode_full(tn, inode)) 529 tn = resize(t, inode); 530 } 531 532 return tp; 533} 534 535static struct key_vector *inflate(struct trie *t, 536 struct key_vector *oldtnode) 537{ 538 struct key_vector *tn; 539 unsigned long i; 540 t_key m; 541 542 pr_debug("In inflate\n"); 543 544 tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1); 545 if (!tn) 546 goto notnode; 547 548 /* prepare oldtnode to be freed */ 549 tnode_free_init(oldtnode); 550 551 /* Assemble all of the pointers in our cluster, in this case that 552 * represents all of the pointers out of our allocated nodes that 553 * point to existing tnodes and the links between our allocated 554 * nodes. 555 */ 556 for (i = child_length(oldtnode), m = 1u << tn->pos; i;) { 557 struct key_vector *inode = get_child(oldtnode, --i); 558 struct key_vector *node0, *node1; 559 unsigned long j, k; 560 561 /* An empty child */ 562 if (!inode) 563 continue; 564 565 /* A leaf or an internal node with skipped bits */ 566 if (!tnode_full(oldtnode, inode)) { 567 put_child(tn, get_index(inode->key, tn), inode); 568 continue; 569 } 570 571 /* drop the node in the old tnode free list */ 572 tnode_free_append(oldtnode, inode); 573 574 /* An internal node with two children */ 575 if (inode->bits == 1) { 576 put_child(tn, 2 * i + 1, get_child(inode, 1)); 577 put_child(tn, 2 * i, get_child(inode, 0)); 578 continue; 579 } 580 581 /* We will replace this node 'inode' with two new 582 * ones, 'node0' and 'node1', each with half of the 583 * original children. The two new nodes will have 584 * a position one bit further down the key and this 585 * means that the "significant" part of their keys 586 * (see the discussion near the top of this file) 587 * will differ by one bit, which will be "0" in 588 * node0's key and "1" in node1's key. Since we are 589 * moving the key position by one step, the bit that 590 * we are moving away from - the bit at position 591 * (tn->pos) - is the one that will differ between 592 * node0 and node1. So... we synthesize that bit in the 593 * two new keys. 594 */ 595 node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1); 596 if (!node1) 597 goto nomem; 598 node0 = tnode_new(inode->key, inode->pos, inode->bits - 1); 599 600 tnode_free_append(tn, node1); 601 if (!node0) 602 goto nomem; 603 tnode_free_append(tn, node0); 604 605 /* populate child pointers in new nodes */ 606 for (k = child_length(inode), j = k / 2; j;) { 607 put_child(node1, --j, get_child(inode, --k)); 608 put_child(node0, j, get_child(inode, j)); 609 put_child(node1, --j, get_child(inode, --k)); 610 put_child(node0, j, get_child(inode, j)); 611 } 612 613 /* link new nodes to parent */ 614 NODE_INIT_PARENT(node1, tn); 615 NODE_INIT_PARENT(node0, tn); 616 617 /* link parent to nodes */ 618 put_child(tn, 2 * i + 1, node1); 619 put_child(tn, 2 * i, node0); 620 } 621 622 /* setup the parent pointers into and out of this node */ 623 return replace(t, oldtnode, tn); 624nomem: 625 /* all pointers should be clean so we are done */ 626 tnode_free(tn); 627notnode: 628 return NULL; 629} 630 631static struct key_vector *halve(struct trie *t, 632 struct key_vector *oldtnode) 633{ 634 struct key_vector *tn; 635 unsigned long i; 636 637 pr_debug("In halve\n"); 638 639 tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1); 640 if (!tn) 641 goto notnode; 642 643 /* prepare oldtnode to be freed */ 644 tnode_free_init(oldtnode); 645 646 /* Assemble all of the pointers in our cluster, in this case that 647 * represents all of the pointers out of our allocated nodes that 648 * point to existing tnodes and the links between our allocated 649 * nodes. 650 */ 651 for (i = child_length(oldtnode); i;) { 652 struct key_vector *node1 = get_child(oldtnode, --i); 653 struct key_vector *node0 = get_child(oldtnode, --i); 654 struct key_vector *inode; 655 656 /* At least one of the children is empty */ 657 if (!node1 || !node0) { 658 put_child(tn, i / 2, node1 ? : node0); 659 continue; 660 } 661 662 /* Two nonempty children */ 663 inode = tnode_new(node0->key, oldtnode->pos, 1); 664 if (!inode) 665 goto nomem; 666 tnode_free_append(tn, inode); 667 668 /* initialize pointers out of node */ 669 put_child(inode, 1, node1); 670 put_child(inode, 0, node0); 671 NODE_INIT_PARENT(inode, tn); 672 673 /* link parent to node */ 674 put_child(tn, i / 2, inode); 675 } 676 677 /* setup the parent pointers into and out of this node */ 678 return replace(t, oldtnode, tn); 679nomem: 680 /* all pointers should be clean so we are done */ 681 tnode_free(tn); 682notnode: 683 return NULL; 684} 685 686static struct key_vector *collapse(struct trie *t, 687 struct key_vector *oldtnode) 688{ 689 struct key_vector *n, *tp; 690 unsigned long i; 691 692 /* scan the tnode looking for that one child that might still exist */ 693 for (n = NULL, i = child_length(oldtnode); !n && i;) 694 n = get_child(oldtnode, --i); 695 696 /* compress one level */ 697 tp = node_parent(oldtnode); 698 put_child_root(tp, oldtnode->key, n); 699 node_set_parent(n, tp); 700 701 /* drop dead node */ 702 node_free(oldtnode); 703 704 return tp; 705} 706 707static unsigned char update_suffix(struct key_vector *tn) 708{ 709 unsigned char slen = tn->pos; 710 unsigned long stride, i; 711 unsigned char slen_max; 712 713 /* only vector 0 can have a suffix length greater than or equal to 714 * tn->pos + tn->bits, the second highest node will have a suffix 715 * length at most of tn->pos + tn->bits - 1 716 */ 717 slen_max = min_t(unsigned char, tn->pos + tn->bits - 1, tn->slen); 718 719 /* search though the list of children looking for nodes that might 720 * have a suffix greater than the one we currently have. This is 721 * why we start with a stride of 2 since a stride of 1 would 722 * represent the nodes with suffix length equal to tn->pos 723 */ 724 for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) { 725 struct key_vector *n = get_child(tn, i); 726 727 if (!n || (n->slen <= slen)) 728 continue; 729 730 /* update stride and slen based on new value */ 731 stride <<= (n->slen - slen); 732 slen = n->slen; 733 i &= ~(stride - 1); 734 735 /* stop searching if we have hit the maximum possible value */ 736 if (slen >= slen_max) 737 break; 738 } 739 740 tn->slen = slen; 741 742 return slen; 743} 744 745/* From "Implementing a dynamic compressed trie" by Stefan Nilsson of 746 * the Helsinki University of Technology and Matti Tikkanen of Nokia 747 * Telecommunications, page 6: 748 * "A node is doubled if the ratio of non-empty children to all 749 * children in the *doubled* node is at least 'high'." 750 * 751 * 'high' in this instance is the variable 'inflate_threshold'. It 752 * is expressed as a percentage, so we multiply it with 753 * child_length() and instead of multiplying by 2 (since the 754 * child array will be doubled by inflate()) and multiplying 755 * the left-hand side by 100 (to handle the percentage thing) we 756 * multiply the left-hand side by 50. 757 * 758 * The left-hand side may look a bit weird: child_length(tn) 759 * - tn->empty_children is of course the number of non-null children 760 * in the current node. tn->full_children is the number of "full" 761 * children, that is non-null tnodes with a skip value of 0. 762 * All of those will be doubled in the resulting inflated tnode, so 763 * we just count them one extra time here. 764 * 765 * A clearer way to write this would be: 766 * 767 * to_be_doubled = tn->full_children; 768 * not_to_be_doubled = child_length(tn) - tn->empty_children - 769 * tn->full_children; 770 * 771 * new_child_length = child_length(tn) * 2; 772 * 773 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) / 774 * new_child_length; 775 * if (new_fill_factor >= inflate_threshold) 776 * 777 * ...and so on, tho it would mess up the while () loop. 778 * 779 * anyway, 780 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >= 781 * inflate_threshold 782 * 783 * avoid a division: 784 * 100 * (not_to_be_doubled + 2*to_be_doubled) >= 785 * inflate_threshold * new_child_length 786 * 787 * expand not_to_be_doubled and to_be_doubled, and shorten: 788 * 100 * (child_length(tn) - tn->empty_children + 789 * tn->full_children) >= inflate_threshold * new_child_length 790 * 791 * expand new_child_length: 792 * 100 * (child_length(tn) - tn->empty_children + 793 * tn->full_children) >= 794 * inflate_threshold * child_length(tn) * 2 795 * 796 * shorten again: 797 * 50 * (tn->full_children + child_length(tn) - 798 * tn->empty_children) >= inflate_threshold * 799 * child_length(tn) 800 * 801 */ 802static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn) 803{ 804 unsigned long used = child_length(tn); 805 unsigned long threshold = used; 806 807 /* Keep root node larger */ 808 threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold; 809 used -= tn_info(tn)->empty_children; 810 used += tn_info(tn)->full_children; 811 812 /* if bits == KEYLENGTH then pos = 0, and will fail below */ 813 814 return (used > 1) && tn->pos && ((50 * used) >= threshold); 815} 816 817static inline bool should_halve(struct key_vector *tp, struct key_vector *tn) 818{ 819 unsigned long used = child_length(tn); 820 unsigned long threshold = used; 821 822 /* Keep root node larger */ 823 threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold; 824 used -= tn_info(tn)->empty_children; 825 826 /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */ 827 828 return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold); 829} 830 831static inline bool should_collapse(struct key_vector *tn) 832{ 833 unsigned long used = child_length(tn); 834 835 used -= tn_info(tn)->empty_children; 836 837 /* account for bits == KEYLENGTH case */ 838 if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children) 839 used -= KEY_MAX; 840 841 /* One child or none, time to drop us from the trie */ 842 return used < 2; 843} 844 845#define MAX_WORK 10 846static struct key_vector *resize(struct trie *t, struct key_vector *tn) 847{ 848#ifdef CONFIG_IP_FIB_TRIE_STATS 849 struct trie_use_stats __percpu *stats = t->stats; 850#endif 851 struct key_vector *tp = node_parent(tn); 852 unsigned long cindex = get_index(tn->key, tp); 853 int max_work = MAX_WORK; 854 855 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n", 856 tn, inflate_threshold, halve_threshold); 857 858 /* track the tnode via the pointer from the parent instead of 859 * doing it ourselves. This way we can let RCU fully do its 860 * thing without us interfering 861 */ 862 BUG_ON(tn != get_child(tp, cindex)); 863 864 /* Double as long as the resulting node has a number of 865 * nonempty nodes that are above the threshold. 866 */ 867 while (should_inflate(tp, tn) && max_work) { 868 tp = inflate(t, tn); 869 if (!tp) { 870#ifdef CONFIG_IP_FIB_TRIE_STATS 871 this_cpu_inc(stats->resize_node_skipped); 872#endif 873 break; 874 } 875 876 max_work--; 877 tn = get_child(tp, cindex); 878 } 879 880 /* update parent in case inflate failed */ 881 tp = node_parent(tn); 882 883 /* Return if at least one inflate is run */ 884 if (max_work != MAX_WORK) 885 return tp; 886 887 /* Halve as long as the number of empty children in this 888 * node is above threshold. 889 */ 890 while (should_halve(tp, tn) && max_work) { 891 tp = halve(t, tn); 892 if (!tp) { 893#ifdef CONFIG_IP_FIB_TRIE_STATS 894 this_cpu_inc(stats->resize_node_skipped); 895#endif 896 break; 897 } 898 899 max_work--; 900 tn = get_child(tp, cindex); 901 } 902 903 /* Only one child remains */ 904 if (should_collapse(tn)) 905 return collapse(t, tn); 906 907 /* update parent in case halve failed */ 908 return node_parent(tn); 909} 910 911static void node_pull_suffix(struct key_vector *tn, unsigned char slen) 912{ 913 unsigned char node_slen = tn->slen; 914 915 while ((node_slen > tn->pos) && (node_slen > slen)) { 916 slen = update_suffix(tn); 917 if (node_slen == slen) 918 break; 919 920 tn = node_parent(tn); 921 node_slen = tn->slen; 922 } 923} 924 925static void node_push_suffix(struct key_vector *tn, unsigned char slen) 926{ 927 while (tn->slen < slen) { 928 tn->slen = slen; 929 tn = node_parent(tn); 930 } 931} 932 933/* rcu_read_lock needs to be hold by caller from readside */ 934static struct key_vector *fib_find_node(struct trie *t, 935 struct key_vector **tp, u32 key) 936{ 937 struct key_vector *pn, *n = t->kv; 938 unsigned long index = 0; 939 940 do { 941 pn = n; 942 n = get_child_rcu(n, index); 943 944 if (!n) 945 break; 946 947 index = get_cindex(key, n); 948 949 /* This bit of code is a bit tricky but it combines multiple 950 * checks into a single check. The prefix consists of the 951 * prefix plus zeros for the bits in the cindex. The index 952 * is the difference between the key and this value. From 953 * this we can actually derive several pieces of data. 954 * if (index >= (1ul << bits)) 955 * we have a mismatch in skip bits and failed 956 * else 957 * we know the value is cindex 958 * 959 * This check is safe even if bits == KEYLENGTH due to the 960 * fact that we can only allocate a node with 32 bits if a 961 * long is greater than 32 bits. 962 */ 963 if (index >= (1ul << n->bits)) { 964 n = NULL; 965 break; 966 } 967 968 /* keep searching until we find a perfect match leaf or NULL */ 969 } while (IS_TNODE(n)); 970 971 *tp = pn; 972 973 return n; 974} 975 976/* Return the first fib alias matching TOS with 977 * priority less than or equal to PRIO. 978 * If 'find_first' is set, return the first matching 979 * fib alias, regardless of TOS and priority. 980 */ 981static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen, 982 u8 tos, u32 prio, u32 tb_id, 983 bool find_first) 984{ 985 struct fib_alias *fa; 986 987 if (!fah) 988 return NULL; 989 990 hlist_for_each_entry(fa, fah, fa_list) { 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->fa_tos > tos) 1002 continue; 1003 if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos) 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_tos == fri->tos && 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 struct fib_alias *fa_match; 1041 1042 rcu_read_lock(); 1043 1044 fa_match = fib_find_matching_alias(net, fri); 1045 if (!fa_match) 1046 goto out; 1047 1048 fa_match->offload = fri->offload; 1049 fa_match->trap = fri->trap; 1050 1051out: 1052 rcu_read_unlock(); 1053} 1054EXPORT_SYMBOL_GPL(fib_alias_hw_flags_set); 1055 1056static void trie_rebalance(struct trie *t, struct key_vector *tn) 1057{ 1058 while (!IS_TRIE(tn)) 1059 tn = resize(t, tn); 1060} 1061 1062static int fib_insert_node(struct trie *t, struct key_vector *tp, 1063 struct fib_alias *new, t_key key) 1064{ 1065 struct key_vector *n, *l; 1066 1067 l = leaf_new(key, new); 1068 if (!l) 1069 goto noleaf; 1070 1071 /* retrieve child from parent node */ 1072 n = get_child(tp, get_index(key, tp)); 1073 1074 /* Case 2: n is a LEAF or a TNODE and the key doesn't match. 1075 * 1076 * Add a new tnode here 1077 * first tnode need some special handling 1078 * leaves us in position for handling as case 3 1079 */ 1080 if (n) { 1081 struct key_vector *tn; 1082 1083 tn = tnode_new(key, __fls(key ^ n->key), 1); 1084 if (!tn) 1085 goto notnode; 1086 1087 /* initialize routes out of node */ 1088 NODE_INIT_PARENT(tn, tp); 1089 put_child(tn, get_index(key, tn) ^ 1, n); 1090 1091 /* start adding routes into the node */ 1092 put_child_root(tp, key, tn); 1093 node_set_parent(n, tn); 1094 1095 /* parent now has a NULL spot where the leaf can go */ 1096 tp = tn; 1097 } 1098 1099 /* Case 3: n is NULL, and will just insert a new leaf */ 1100 node_push_suffix(tp, new->fa_slen); 1101 NODE_INIT_PARENT(l, tp); 1102 put_child_root(tp, key, l); 1103 trie_rebalance(t, tp); 1104 1105 return 0; 1106notnode: 1107 node_free(l); 1108noleaf: 1109 return -ENOMEM; 1110} 1111 1112static int fib_insert_alias(struct trie *t, struct key_vector *tp, 1113 struct key_vector *l, struct fib_alias *new, 1114 struct fib_alias *fa, t_key key) 1115{ 1116 if (!l) 1117 return fib_insert_node(t, tp, new, key); 1118 1119 if (fa) { 1120 hlist_add_before_rcu(&new->fa_list, &fa->fa_list); 1121 } else { 1122 struct fib_alias *last; 1123 1124 hlist_for_each_entry(last, &l->leaf, fa_list) { 1125 if (new->fa_slen < last->fa_slen) 1126 break; 1127 if ((new->fa_slen == last->fa_slen) && 1128 (new->tb_id > last->tb_id)) 1129 break; 1130 fa = last; 1131 } 1132 1133 if (fa) 1134 hlist_add_behind_rcu(&new->fa_list, &fa->fa_list); 1135 else 1136 hlist_add_head_rcu(&new->fa_list, &l->leaf); 1137 } 1138 1139 /* if we added to the tail node then we need to update slen */ 1140 if (l->slen < new->fa_slen) { 1141 l->slen = new->fa_slen; 1142 node_push_suffix(tp, new->fa_slen); 1143 } 1144 1145 return 0; 1146} 1147 1148static bool fib_valid_key_len(u32 key, u8 plen, struct netlink_ext_ack *extack) 1149{ 1150 if (plen > KEYLENGTH) { 1151 NL_SET_ERR_MSG(extack, "Invalid prefix length"); 1152 return false; 1153 } 1154 1155 if ((plen < KEYLENGTH) && (key << plen)) { 1156 NL_SET_ERR_MSG(extack, 1157 "Invalid prefix for given prefix length"); 1158 return false; 1159 } 1160 1161 return true; 1162} 1163 1164static void fib_remove_alias(struct trie *t, struct key_vector *tp, 1165 struct key_vector *l, struct fib_alias *old); 1166 1167/* Caller must hold RTNL. */ 1168int fib_table_insert(struct net *net, struct fib_table *tb, 1169 struct fib_config *cfg, struct netlink_ext_ack *extack) 1170{ 1171 struct trie *t = (struct trie *)tb->tb_data; 1172 struct fib_alias *fa, *new_fa; 1173 struct key_vector *l, *tp; 1174 u16 nlflags = NLM_F_EXCL; 1175 struct fib_info *fi; 1176 u8 plen = cfg->fc_dst_len; 1177 u8 slen = KEYLENGTH - plen; 1178 u8 tos = cfg->fc_tos; 1179 u32 key; 1180 int err; 1181 1182 key = ntohl(cfg->fc_dst); 1183 1184 if (!fib_valid_key_len(key, plen, extack)) 1185 return -EINVAL; 1186 1187 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen); 1188 1189 fi = fib_create_info(cfg, extack); 1190 if (IS_ERR(fi)) { 1191 err = PTR_ERR(fi); 1192 goto err; 1193 } 1194 1195 l = fib_find_node(t, &tp, key); 1196 fa = l ? fib_find_alias(&l->leaf, slen, tos, fi->fib_priority, 1197 tb->tb_id, false) : NULL; 1198 1199 /* Now fa, if non-NULL, points to the first fib alias 1200 * with the same keys [prefix,tos,priority], if such key already 1201 * exists or to the node before which we will insert new one. 1202 * 1203 * If fa is NULL, we will need to allocate a new one and 1204 * insert to the tail of the section matching the suffix length 1205 * of the new alias. 1206 */ 1207 1208 if (fa && fa->fa_tos == tos && 1209 fa->fa_info->fib_priority == fi->fib_priority) { 1210 struct fib_alias *fa_first, *fa_match; 1211 1212 err = -EEXIST; 1213 if (cfg->fc_nlflags & NLM_F_EXCL) 1214 goto out; 1215 1216 nlflags &= ~NLM_F_EXCL; 1217 1218 /* We have 2 goals: 1219 * 1. Find exact match for type, scope, fib_info to avoid 1220 * duplicate routes 1221 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it 1222 */ 1223 fa_match = NULL; 1224 fa_first = fa; 1225 hlist_for_each_entry_from(fa, fa_list) { 1226 if ((fa->fa_slen != slen) || 1227 (fa->tb_id != tb->tb_id) || 1228 (fa->fa_tos != tos)) 1229 break; 1230 if (fa->fa_info->fib_priority != fi->fib_priority) 1231 break; 1232 if (fa->fa_type == cfg->fc_type && 1233 fa->fa_info == fi) { 1234 fa_match = fa; 1235 break; 1236 } 1237 } 1238 1239 if (cfg->fc_nlflags & NLM_F_REPLACE) { 1240 struct fib_info *fi_drop; 1241 u8 state; 1242 1243 nlflags |= NLM_F_REPLACE; 1244 fa = fa_first; 1245 if (fa_match) { 1246 if (fa == fa_match) 1247 err = 0; 1248 goto out; 1249 } 1250 err = -ENOBUFS; 1251 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1252 if (!new_fa) 1253 goto out; 1254 1255 fi_drop = fa->fa_info; 1256 new_fa->fa_tos = fa->fa_tos; 1257 new_fa->fa_info = fi; 1258 new_fa->fa_type = cfg->fc_type; 1259 state = fa->fa_state; 1260 new_fa->fa_state = state & ~FA_S_ACCESSED; 1261 new_fa->fa_slen = fa->fa_slen; 1262 new_fa->tb_id = tb->tb_id; 1263 new_fa->fa_default = -1; 1264 new_fa->offload = 0; 1265 new_fa->trap = 0; 1266 1267 hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list); 1268 1269 if (fib_find_alias(&l->leaf, fa->fa_slen, 0, 0, 1270 tb->tb_id, true) == new_fa) { 1271 enum fib_event_type fib_event; 1272 1273 fib_event = FIB_EVENT_ENTRY_REPLACE; 1274 err = call_fib_entry_notifiers(net, fib_event, 1275 key, plen, 1276 new_fa, extack); 1277 if (err) { 1278 hlist_replace_rcu(&new_fa->fa_list, 1279 &fa->fa_list); 1280 goto out_free_new_fa; 1281 } 1282 } 1283 1284 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, 1285 tb->tb_id, &cfg->fc_nlinfo, nlflags); 1286 1287 alias_free_mem_rcu(fa); 1288 1289 fib_release_info(fi_drop); 1290 if (state & FA_S_ACCESSED) 1291 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1292 1293 goto succeeded; 1294 } 1295 /* Error if we find a perfect match which 1296 * uses the same scope, type, and nexthop 1297 * information. 1298 */ 1299 if (fa_match) 1300 goto out; 1301 1302 if (cfg->fc_nlflags & NLM_F_APPEND) 1303 nlflags |= NLM_F_APPEND; 1304 else 1305 fa = fa_first; 1306 } 1307 err = -ENOENT; 1308 if (!(cfg->fc_nlflags & NLM_F_CREATE)) 1309 goto out; 1310 1311 nlflags |= NLM_F_CREATE; 1312 err = -ENOBUFS; 1313 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1314 if (!new_fa) 1315 goto out; 1316 1317 new_fa->fa_info = fi; 1318 new_fa->fa_tos = tos; 1319 new_fa->fa_type = cfg->fc_type; 1320 new_fa->fa_state = 0; 1321 new_fa->fa_slen = slen; 1322 new_fa->tb_id = tb->tb_id; 1323 new_fa->fa_default = -1; 1324 new_fa->offload = 0; 1325 new_fa->trap = 0; 1326 1327 /* Insert new entry to the list. */ 1328 err = fib_insert_alias(t, tp, l, new_fa, fa, key); 1329 if (err) 1330 goto out_free_new_fa; 1331 1332 /* The alias was already inserted, so the node must exist. */ 1333 l = l ? l : fib_find_node(t, &tp, key); 1334 if (WARN_ON_ONCE(!l)) { 1335 err = -ENOENT; 1336 goto out_free_new_fa; 1337 } 1338 1339 if (fib_find_alias(&l->leaf, new_fa->fa_slen, 0, 0, tb->tb_id, true) == 1340 new_fa) { 1341 enum fib_event_type fib_event; 1342 1343 fib_event = FIB_EVENT_ENTRY_REPLACE; 1344 err = call_fib_entry_notifiers(net, fib_event, key, plen, 1345 new_fa, extack); 1346 if (err) 1347 goto out_remove_new_fa; 1348 } 1349 1350 if (!plen) 1351 tb->tb_num_default++; 1352 1353 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1354 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id, 1355 &cfg->fc_nlinfo, nlflags); 1356succeeded: 1357 return 0; 1358 1359out_remove_new_fa: 1360 fib_remove_alias(t, tp, l, new_fa); 1361out_free_new_fa: 1362 kmem_cache_free(fn_alias_kmem, new_fa); 1363out: 1364 fib_release_info(fi); 1365err: 1366 return err; 1367} 1368 1369static inline t_key prefix_mismatch(t_key key, struct key_vector *n) 1370{ 1371 t_key prefix = n->key; 1372 1373 return (key ^ prefix) & (prefix | -prefix); 1374} 1375 1376bool fib_lookup_good_nhc(const struct fib_nh_common *nhc, int fib_flags, 1377 const struct flowi4 *flp) 1378{ 1379 if (nhc->nhc_flags & RTNH_F_DEAD) 1380 return false; 1381 1382 if (ip_ignore_linkdown(nhc->nhc_dev) && 1383 nhc->nhc_flags & RTNH_F_LINKDOWN && 1384 !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE)) 1385 return false; 1386 1387 if (!(flp->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) { 1388 if (flp->flowi4_oif && 1389 flp->flowi4_oif != nhc->nhc_oif) 1390 return false; 1391 } 1392 1393 return true; 1394} 1395 1396/* should be called with rcu_read_lock */ 1397int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 1398 struct fib_result *res, int fib_flags) 1399{ 1400 struct trie *t = (struct trie *) tb->tb_data; 1401#ifdef CONFIG_IP_FIB_TRIE_STATS 1402 struct trie_use_stats __percpu *stats = t->stats; 1403#endif 1404 const t_key key = ntohl(flp->daddr); 1405 struct key_vector *n, *pn; 1406 struct fib_alias *fa; 1407 unsigned long index; 1408 t_key cindex; 1409 1410 pn = t->kv; 1411 cindex = 0; 1412 1413 n = get_child_rcu(pn, cindex); 1414 if (!n) { 1415 trace_fib_table_lookup(tb->tb_id, flp, NULL, -EAGAIN); 1416 return -EAGAIN; 1417 } 1418 1419#ifdef CONFIG_IP_FIB_TRIE_STATS 1420 this_cpu_inc(stats->gets); 1421#endif 1422 1423 /* Step 1: Travel to the longest prefix match in the trie */ 1424 for (;;) { 1425 index = get_cindex(key, n); 1426 1427 /* This bit of code is a bit tricky but it combines multiple 1428 * checks into a single check. The prefix consists of the 1429 * prefix plus zeros for the "bits" in the prefix. The index 1430 * is the difference between the key and this value. From 1431 * this we can actually derive several pieces of data. 1432 * if (index >= (1ul << bits)) 1433 * we have a mismatch in skip bits and failed 1434 * else 1435 * we know the value is cindex 1436 * 1437 * This check is safe even if bits == KEYLENGTH due to the 1438 * fact that we can only allocate a node with 32 bits if a 1439 * long is greater than 32 bits. 1440 */ 1441 if (index >= (1ul << n->bits)) 1442 break; 1443 1444 /* we have found a leaf. Prefixes have already been compared */ 1445 if (IS_LEAF(n)) 1446 goto found; 1447 1448 /* only record pn and cindex if we are going to be chopping 1449 * bits later. Otherwise we are just wasting cycles. 1450 */ 1451 if (n->slen > n->pos) { 1452 pn = n; 1453 cindex = index; 1454 } 1455 1456 n = get_child_rcu(n, index); 1457 if (unlikely(!n)) 1458 goto backtrace; 1459 } 1460 1461 /* Step 2: Sort out leaves and begin backtracing for longest prefix */ 1462 for (;;) { 1463 /* record the pointer where our next node pointer is stored */ 1464 struct key_vector __rcu **cptr = n->tnode; 1465 1466 /* This test verifies that none of the bits that differ 1467 * between the key and the prefix exist in the region of 1468 * the lsb and higher in the prefix. 1469 */ 1470 if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos)) 1471 goto backtrace; 1472 1473 /* exit out and process leaf */ 1474 if (unlikely(IS_LEAF(n))) 1475 break; 1476 1477 /* Don't bother recording parent info. Since we are in 1478 * prefix match mode we will have to come back to wherever 1479 * we started this traversal anyway 1480 */ 1481 1482 while ((n = rcu_dereference(*cptr)) == NULL) { 1483backtrace: 1484#ifdef CONFIG_IP_FIB_TRIE_STATS 1485 if (!n) 1486 this_cpu_inc(stats->null_node_hit); 1487#endif 1488 /* If we are at cindex 0 there are no more bits for 1489 * us to strip at this level so we must ascend back 1490 * up one level to see if there are any more bits to 1491 * be stripped there. 1492 */ 1493 while (!cindex) { 1494 t_key pkey = pn->key; 1495 1496 /* If we don't have a parent then there is 1497 * nothing for us to do as we do not have any 1498 * further nodes to parse. 1499 */ 1500 if (IS_TRIE(pn)) { 1501 trace_fib_table_lookup(tb->tb_id, flp, 1502 NULL, -EAGAIN); 1503 return -EAGAIN; 1504 } 1505#ifdef CONFIG_IP_FIB_TRIE_STATS 1506 this_cpu_inc(stats->backtrack); 1507#endif 1508 /* Get Child's index */ 1509 pn = node_parent_rcu(pn); 1510 cindex = get_index(pkey, pn); 1511 } 1512 1513 /* strip the least significant bit from the cindex */ 1514 cindex &= cindex - 1; 1515 1516 /* grab pointer for next child node */ 1517 cptr = &pn->tnode[cindex]; 1518 } 1519 } 1520 1521found: 1522 /* this line carries forward the xor from earlier in the function */ 1523 index = key ^ n->key; 1524 1525 /* Step 3: Process the leaf, if that fails fall back to backtracing */ 1526 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) { 1527 struct fib_info *fi = fa->fa_info; 1528 struct fib_nh_common *nhc; 1529 int nhsel, err; 1530 1531 if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) { 1532 if (index >= (1ul << fa->fa_slen)) 1533 continue; 1534 } 1535 if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos) 1536 continue; 1537 /* Paired with WRITE_ONCE() in fib_release_info() */ 1538 if (READ_ONCE(fi->fib_dead)) 1539 continue; 1540 if (fa->fa_info->fib_scope < flp->flowi4_scope) 1541 continue; 1542 fib_alias_accessed(fa); 1543 err = fib_props[fa->fa_type].error; 1544 if (unlikely(err < 0)) { 1545out_reject: 1546#ifdef CONFIG_IP_FIB_TRIE_STATS 1547 this_cpu_inc(stats->semantic_match_passed); 1548#endif 1549 trace_fib_table_lookup(tb->tb_id, flp, NULL, err); 1550 return err; 1551 } 1552 if (fi->fib_flags & RTNH_F_DEAD) 1553 continue; 1554 1555 if (unlikely(fi->nh)) { 1556 if (nexthop_is_blackhole(fi->nh)) { 1557 err = fib_props[RTN_BLACKHOLE].error; 1558 goto out_reject; 1559 } 1560 1561 nhc = nexthop_get_nhc_lookup(fi->nh, fib_flags, flp, 1562 &nhsel); 1563 if (nhc) 1564 goto set_result; 1565 goto miss; 1566 } 1567 1568 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 1569 nhc = fib_info_nhc(fi, nhsel); 1570 1571 if (!fib_lookup_good_nhc(nhc, fib_flags, flp)) 1572 continue; 1573set_result: 1574 if (!(fib_flags & FIB_LOOKUP_NOREF)) 1575 refcount_inc(&fi->fib_clntref); 1576 1577 res->prefix = htonl(n->key); 1578 res->prefixlen = KEYLENGTH - fa->fa_slen; 1579 res->nh_sel = nhsel; 1580 res->nhc = nhc; 1581 res->type = fa->fa_type; 1582 res->scope = fi->fib_scope; 1583 res->fi = fi; 1584 res->table = tb; 1585 res->fa_head = &n->leaf; 1586#ifdef CONFIG_IP_FIB_TRIE_STATS 1587 this_cpu_inc(stats->semantic_match_passed); 1588#endif 1589 trace_fib_table_lookup(tb->tb_id, flp, nhc, err); 1590 1591 return err; 1592 } 1593 } 1594miss: 1595#ifdef CONFIG_IP_FIB_TRIE_STATS 1596 this_cpu_inc(stats->semantic_match_miss); 1597#endif 1598 goto backtrace; 1599} 1600EXPORT_SYMBOL_GPL(fib_table_lookup); 1601 1602static void fib_remove_alias(struct trie *t, struct key_vector *tp, 1603 struct key_vector *l, struct fib_alias *old) 1604{ 1605 /* record the location of the previous list_info entry */ 1606 struct hlist_node **pprev = old->fa_list.pprev; 1607 struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next); 1608 1609 /* remove the fib_alias from the list */ 1610 hlist_del_rcu(&old->fa_list); 1611 1612 /* if we emptied the list this leaf will be freed and we can sort 1613 * out parent suffix lengths as a part of trie_rebalance 1614 */ 1615 if (hlist_empty(&l->leaf)) { 1616 if (tp->slen == l->slen) 1617 node_pull_suffix(tp, tp->pos); 1618 put_child_root(tp, l->key, NULL); 1619 node_free(l); 1620 trie_rebalance(t, tp); 1621 return; 1622 } 1623 1624 /* only access fa if it is pointing at the last valid hlist_node */ 1625 if (*pprev) 1626 return; 1627 1628 /* update the trie with the latest suffix length */ 1629 l->slen = fa->fa_slen; 1630 node_pull_suffix(tp, fa->fa_slen); 1631} 1632 1633static void fib_notify_alias_delete(struct net *net, u32 key, 1634 struct hlist_head *fah, 1635 struct fib_alias *fa_to_delete, 1636 struct netlink_ext_ack *extack) 1637{ 1638 struct fib_alias *fa_next, *fa_to_notify; 1639 u32 tb_id = fa_to_delete->tb_id; 1640 u8 slen = fa_to_delete->fa_slen; 1641 enum fib_event_type fib_event; 1642 1643 /* Do not notify if we do not care about the route. */ 1644 if (fib_find_alias(fah, slen, 0, 0, tb_id, true) != fa_to_delete) 1645 return; 1646 1647 /* Determine if the route should be replaced by the next route in the 1648 * list. 1649 */ 1650 fa_next = hlist_entry_safe(fa_to_delete->fa_list.next, 1651 struct fib_alias, fa_list); 1652 if (fa_next && fa_next->fa_slen == slen && fa_next->tb_id == tb_id) { 1653 fib_event = FIB_EVENT_ENTRY_REPLACE; 1654 fa_to_notify = fa_next; 1655 } else { 1656 fib_event = FIB_EVENT_ENTRY_DEL; 1657 fa_to_notify = fa_to_delete; 1658 } 1659 call_fib_entry_notifiers(net, fib_event, key, KEYLENGTH - slen, 1660 fa_to_notify, extack); 1661} 1662 1663/* Caller must hold RTNL. */ 1664int fib_table_delete(struct net *net, struct fib_table *tb, 1665 struct fib_config *cfg, struct netlink_ext_ack *extack) 1666{ 1667 struct trie *t = (struct trie *) tb->tb_data; 1668 struct fib_alias *fa, *fa_to_delete; 1669 struct key_vector *l, *tp; 1670 u8 plen = cfg->fc_dst_len; 1671 u8 slen = KEYLENGTH - plen; 1672 u8 tos = cfg->fc_tos; 1673 u32 key; 1674 1675 key = ntohl(cfg->fc_dst); 1676 1677 if (!fib_valid_key_len(key, plen, extack)) 1678 return -EINVAL; 1679 1680 l = fib_find_node(t, &tp, key); 1681 if (!l) 1682 return -ESRCH; 1683 1684 fa = fib_find_alias(&l->leaf, slen, tos, 0, tb->tb_id, false); 1685 if (!fa) 1686 return -ESRCH; 1687 1688 pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t); 1689 1690 fa_to_delete = NULL; 1691 hlist_for_each_entry_from(fa, fa_list) { 1692 struct fib_info *fi = fa->fa_info; 1693 1694 if ((fa->fa_slen != slen) || 1695 (fa->tb_id != tb->tb_id) || 1696 (fa->fa_tos != tos)) 1697 break; 1698 1699 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) && 1700 (cfg->fc_scope == RT_SCOPE_NOWHERE || 1701 fa->fa_info->fib_scope == cfg->fc_scope) && 1702 (!cfg->fc_prefsrc || 1703 fi->fib_prefsrc == cfg->fc_prefsrc) && 1704 (!cfg->fc_protocol || 1705 fi->fib_protocol == cfg->fc_protocol) && 1706 fib_nh_match(net, cfg, fi, extack) == 0 && 1707 fib_metrics_match(cfg, fi)) { 1708 fa_to_delete = fa; 1709 break; 1710 } 1711 } 1712 1713 if (!fa_to_delete) 1714 return -ESRCH; 1715 1716 fib_notify_alias_delete(net, key, &l->leaf, fa_to_delete, extack); 1717 rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id, 1718 &cfg->fc_nlinfo, 0); 1719 1720 if (!plen) 1721 tb->tb_num_default--; 1722 1723 fib_remove_alias(t, tp, l, fa_to_delete); 1724 1725 if (fa_to_delete->fa_state & FA_S_ACCESSED) 1726 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1727 1728 fib_release_info(fa_to_delete->fa_info); 1729 alias_free_mem_rcu(fa_to_delete); 1730 return 0; 1731} 1732 1733/* Scan for the next leaf starting at the provided key value */ 1734static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key) 1735{ 1736 struct key_vector *pn, *n = *tn; 1737 unsigned long cindex; 1738 1739 /* this loop is meant to try and find the key in the trie */ 1740 do { 1741 /* record parent and next child index */ 1742 pn = n; 1743 cindex = (key > pn->key) ? get_index(key, pn) : 0; 1744 1745 if (cindex >> pn->bits) 1746 break; 1747 1748 /* descend into the next child */ 1749 n = get_child_rcu(pn, cindex++); 1750 if (!n) 1751 break; 1752 1753 /* guarantee forward progress on the keys */ 1754 if (IS_LEAF(n) && (n->key >= key)) 1755 goto found; 1756 } while (IS_TNODE(n)); 1757 1758 /* this loop will search for the next leaf with a greater key */ 1759 while (!IS_TRIE(pn)) { 1760 /* if we exhausted the parent node we will need to climb */ 1761 if (cindex >= (1ul << pn->bits)) { 1762 t_key pkey = pn->key; 1763 1764 pn = node_parent_rcu(pn); 1765 cindex = get_index(pkey, pn) + 1; 1766 continue; 1767 } 1768 1769 /* grab the next available node */ 1770 n = get_child_rcu(pn, cindex++); 1771 if (!n) 1772 continue; 1773 1774 /* no need to compare keys since we bumped the index */ 1775 if (IS_LEAF(n)) 1776 goto found; 1777 1778 /* Rescan start scanning in new node */ 1779 pn = n; 1780 cindex = 0; 1781 } 1782 1783 *tn = pn; 1784 return NULL; /* Root of trie */ 1785found: 1786 /* if we are at the limit for keys just return NULL for the tnode */ 1787 *tn = pn; 1788 return n; 1789} 1790 1791static void fib_trie_free(struct fib_table *tb) 1792{ 1793 struct trie *t = (struct trie *)tb->tb_data; 1794 struct key_vector *pn = t->kv; 1795 unsigned long cindex = 1; 1796 struct hlist_node *tmp; 1797 struct fib_alias *fa; 1798 1799 /* walk trie in reverse order and free everything */ 1800 for (;;) { 1801 struct key_vector *n; 1802 1803 if (!(cindex--)) { 1804 t_key pkey = pn->key; 1805 1806 if (IS_TRIE(pn)) 1807 break; 1808 1809 n = pn; 1810 pn = node_parent(pn); 1811 1812 /* drop emptied tnode */ 1813 put_child_root(pn, n->key, NULL); 1814 node_free(n); 1815 1816 cindex = get_index(pkey, pn); 1817 1818 continue; 1819 } 1820 1821 /* grab the next available node */ 1822 n = get_child(pn, cindex); 1823 if (!n) 1824 continue; 1825 1826 if (IS_TNODE(n)) { 1827 /* record pn and cindex for leaf walking */ 1828 pn = n; 1829 cindex = 1ul << n->bits; 1830 1831 continue; 1832 } 1833 1834 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 1835 hlist_del_rcu(&fa->fa_list); 1836 alias_free_mem_rcu(fa); 1837 } 1838 1839 put_child_root(pn, n->key, NULL); 1840 node_free(n); 1841 } 1842 1843#ifdef CONFIG_IP_FIB_TRIE_STATS 1844 free_percpu(t->stats); 1845#endif 1846 kfree(tb); 1847} 1848 1849struct fib_table *fib_trie_unmerge(struct fib_table *oldtb) 1850{ 1851 struct trie *ot = (struct trie *)oldtb->tb_data; 1852 struct key_vector *l, *tp = ot->kv; 1853 struct fib_table *local_tb; 1854 struct fib_alias *fa; 1855 struct trie *lt; 1856 t_key key = 0; 1857 1858 if (oldtb->tb_data == oldtb->__data) 1859 return oldtb; 1860 1861 local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL); 1862 if (!local_tb) 1863 return NULL; 1864 1865 lt = (struct trie *)local_tb->tb_data; 1866 1867 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 1868 struct key_vector *local_l = NULL, *local_tp; 1869 1870 hlist_for_each_entry(fa, &l->leaf, fa_list) { 1871 struct fib_alias *new_fa; 1872 1873 if (local_tb->tb_id != fa->tb_id) 1874 continue; 1875 1876 /* clone fa for new local table */ 1877 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1878 if (!new_fa) 1879 goto out; 1880 1881 memcpy(new_fa, fa, sizeof(*fa)); 1882 1883 /* insert clone into table */ 1884 if (!local_l) 1885 local_l = fib_find_node(lt, &local_tp, l->key); 1886 1887 if (fib_insert_alias(lt, local_tp, local_l, new_fa, 1888 NULL, l->key)) { 1889 kmem_cache_free(fn_alias_kmem, new_fa); 1890 goto out; 1891 } 1892 } 1893 1894 /* stop loop if key wrapped back to 0 */ 1895 key = l->key + 1; 1896 if (key < l->key) 1897 break; 1898 } 1899 1900 return local_tb; 1901out: 1902 fib_trie_free(local_tb); 1903 1904 return NULL; 1905} 1906 1907/* Caller must hold RTNL */ 1908void fib_table_flush_external(struct fib_table *tb) 1909{ 1910 struct trie *t = (struct trie *)tb->tb_data; 1911 struct key_vector *pn = t->kv; 1912 unsigned long cindex = 1; 1913 struct hlist_node *tmp; 1914 struct fib_alias *fa; 1915 1916 /* walk trie in reverse order */ 1917 for (;;) { 1918 unsigned char slen = 0; 1919 struct key_vector *n; 1920 1921 if (!(cindex--)) { 1922 t_key pkey = pn->key; 1923 1924 /* cannot resize the trie vector */ 1925 if (IS_TRIE(pn)) 1926 break; 1927 1928 /* update the suffix to address pulled leaves */ 1929 if (pn->slen > pn->pos) 1930 update_suffix(pn); 1931 1932 /* resize completed node */ 1933 pn = resize(t, pn); 1934 cindex = get_index(pkey, pn); 1935 1936 continue; 1937 } 1938 1939 /* grab the next available node */ 1940 n = get_child(pn, cindex); 1941 if (!n) 1942 continue; 1943 1944 if (IS_TNODE(n)) { 1945 /* record pn and cindex for leaf walking */ 1946 pn = n; 1947 cindex = 1ul << n->bits; 1948 1949 continue; 1950 } 1951 1952 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 1953 /* if alias was cloned to local then we just 1954 * need to remove the local copy from main 1955 */ 1956 if (tb->tb_id != fa->tb_id) { 1957 hlist_del_rcu(&fa->fa_list); 1958 alias_free_mem_rcu(fa); 1959 continue; 1960 } 1961 1962 /* record local slen */ 1963 slen = fa->fa_slen; 1964 } 1965 1966 /* update leaf slen */ 1967 n->slen = slen; 1968 1969 if (hlist_empty(&n->leaf)) { 1970 put_child_root(pn, n->key, NULL); 1971 node_free(n); 1972 } 1973 } 1974} 1975 1976/* Caller must hold RTNL. */ 1977int fib_table_flush(struct net *net, struct fib_table *tb, bool flush_all) 1978{ 1979 struct trie *t = (struct trie *)tb->tb_data; 1980 struct nl_info info = { .nl_net = net }; 1981 struct key_vector *pn = t->kv; 1982 unsigned long cindex = 1; 1983 struct hlist_node *tmp; 1984 struct fib_alias *fa; 1985 int found = 0; 1986 1987 /* walk trie in reverse order */ 1988 for (;;) { 1989 unsigned char slen = 0; 1990 struct key_vector *n; 1991 1992 if (!(cindex--)) { 1993 t_key pkey = pn->key; 1994 1995 /* cannot resize the trie vector */ 1996 if (IS_TRIE(pn)) 1997 break; 1998 1999 /* update the suffix to address pulled leaves */ 2000 if (pn->slen > pn->pos) 2001 update_suffix(pn); 2002 2003 /* resize completed node */ 2004 pn = resize(t, pn); 2005 cindex = get_index(pkey, pn); 2006 2007 continue; 2008 } 2009 2010 /* grab the next available node */ 2011 n = get_child(pn, cindex); 2012 if (!n) 2013 continue; 2014 2015 if (IS_TNODE(n)) { 2016 /* record pn and cindex for leaf walking */ 2017 pn = n; 2018 cindex = 1ul << n->bits; 2019 2020 continue; 2021 } 2022 2023 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 2024 struct fib_info *fi = fa->fa_info; 2025 2026 if (!fi || tb->tb_id != fa->tb_id || 2027 (!(fi->fib_flags & RTNH_F_DEAD) && 2028 !fib_props[fa->fa_type].error)) { 2029 slen = fa->fa_slen; 2030 continue; 2031 } 2032 2033 /* Do not flush error routes if network namespace is 2034 * not being dismantled 2035 */ 2036 if (!flush_all && fib_props[fa->fa_type].error) { 2037 slen = fa->fa_slen; 2038 continue; 2039 } 2040 2041 fib_notify_alias_delete(net, n->key, &n->leaf, fa, 2042 NULL); 2043 if (fi->pfsrc_removed) 2044 rtmsg_fib(RTM_DELROUTE, htonl(n->key), fa, 2045 KEYLENGTH - fa->fa_slen, tb->tb_id, &info, 0); 2046 hlist_del_rcu(&fa->fa_list); 2047 fib_release_info(fa->fa_info); 2048 alias_free_mem_rcu(fa); 2049 found++; 2050 } 2051 2052 /* update leaf slen */ 2053 n->slen = slen; 2054 2055 if (hlist_empty(&n->leaf)) { 2056 put_child_root(pn, n->key, NULL); 2057 node_free(n); 2058 } 2059 } 2060 2061 pr_debug("trie_flush found=%d\n", found); 2062 return found; 2063} 2064 2065/* derived from fib_trie_free */ 2066static void __fib_info_notify_update(struct net *net, struct fib_table *tb, 2067 struct nl_info *info) 2068{ 2069 struct trie *t = (struct trie *)tb->tb_data; 2070 struct key_vector *pn = t->kv; 2071 unsigned long cindex = 1; 2072 struct fib_alias *fa; 2073 2074 for (;;) { 2075 struct key_vector *n; 2076 2077 if (!(cindex--)) { 2078 t_key pkey = pn->key; 2079 2080 if (IS_TRIE(pn)) 2081 break; 2082 2083 pn = node_parent(pn); 2084 cindex = get_index(pkey, pn); 2085 continue; 2086 } 2087 2088 /* grab the next available node */ 2089 n = get_child(pn, cindex); 2090 if (!n) 2091 continue; 2092 2093 if (IS_TNODE(n)) { 2094 /* record pn and cindex for leaf walking */ 2095 pn = n; 2096 cindex = 1ul << n->bits; 2097 2098 continue; 2099 } 2100 2101 hlist_for_each_entry(fa, &n->leaf, fa_list) { 2102 struct fib_info *fi = fa->fa_info; 2103 2104 if (!fi || !fi->nh_updated || fa->tb_id != tb->tb_id) 2105 continue; 2106 2107 rtmsg_fib(RTM_NEWROUTE, htonl(n->key), fa, 2108 KEYLENGTH - fa->fa_slen, tb->tb_id, 2109 info, NLM_F_REPLACE); 2110 2111 /* call_fib_entry_notifiers will be removed when 2112 * in-kernel notifier is implemented and supported 2113 * for nexthop objects 2114 */ 2115 call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, 2116 n->key, 2117 KEYLENGTH - fa->fa_slen, fa, 2118 NULL); 2119 } 2120 } 2121} 2122 2123void fib_info_notify_update(struct net *net, struct nl_info *info) 2124{ 2125 unsigned int h; 2126 2127 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2128 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2129 struct fib_table *tb; 2130 2131 hlist_for_each_entry_rcu(tb, head, tb_hlist, 2132 lockdep_rtnl_is_held()) 2133 __fib_info_notify_update(net, tb, info); 2134 } 2135} 2136 2137static int fib_leaf_notify(struct key_vector *l, struct fib_table *tb, 2138 struct notifier_block *nb, 2139 struct netlink_ext_ack *extack) 2140{ 2141 struct fib_alias *fa; 2142 int last_slen = -1; 2143 int err; 2144 2145 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 2146 struct fib_info *fi = fa->fa_info; 2147 2148 if (!fi) 2149 continue; 2150 2151 /* local and main table can share the same trie, 2152 * so don't notify twice for the same entry. 2153 */ 2154 if (tb->tb_id != fa->tb_id) 2155 continue; 2156 2157 if (fa->fa_slen == last_slen) 2158 continue; 2159 2160 last_slen = fa->fa_slen; 2161 err = call_fib_entry_notifier(nb, FIB_EVENT_ENTRY_REPLACE, 2162 l->key, KEYLENGTH - fa->fa_slen, 2163 fa, extack); 2164 if (err) 2165 return err; 2166 } 2167 return 0; 2168} 2169 2170static int fib_table_notify(struct fib_table *tb, struct notifier_block *nb, 2171 struct netlink_ext_ack *extack) 2172{ 2173 struct trie *t = (struct trie *)tb->tb_data; 2174 struct key_vector *l, *tp = t->kv; 2175 t_key key = 0; 2176 int err; 2177 2178 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 2179 err = fib_leaf_notify(l, tb, nb, extack); 2180 if (err) 2181 return err; 2182 2183 key = l->key + 1; 2184 /* stop in case of wrap around */ 2185 if (key < l->key) 2186 break; 2187 } 2188 return 0; 2189} 2190 2191int fib_notify(struct net *net, struct notifier_block *nb, 2192 struct netlink_ext_ack *extack) 2193{ 2194 unsigned int h; 2195 int err; 2196 2197 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2198 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2199 struct fib_table *tb; 2200 2201 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2202 err = fib_table_notify(tb, nb, extack); 2203 if (err) 2204 return err; 2205 } 2206 } 2207 return 0; 2208} 2209 2210static void __trie_free_rcu(struct rcu_head *head) 2211{ 2212 struct fib_table *tb = container_of(head, struct fib_table, rcu); 2213#ifdef CONFIG_IP_FIB_TRIE_STATS 2214 struct trie *t = (struct trie *)tb->tb_data; 2215 2216 if (tb->tb_data == tb->__data) 2217 free_percpu(t->stats); 2218#endif /* CONFIG_IP_FIB_TRIE_STATS */ 2219 kfree(tb); 2220} 2221 2222void fib_free_table(struct fib_table *tb) 2223{ 2224 call_rcu(&tb->rcu, __trie_free_rcu); 2225} 2226 2227static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb, 2228 struct sk_buff *skb, struct netlink_callback *cb, 2229 struct fib_dump_filter *filter) 2230{ 2231 unsigned int flags = NLM_F_MULTI; 2232 __be32 xkey = htonl(l->key); 2233 int i, s_i, i_fa, s_fa, err; 2234 struct fib_alias *fa; 2235 2236 if (filter->filter_set || 2237 !filter->dump_exceptions || !filter->dump_routes) 2238 flags |= NLM_F_DUMP_FILTERED; 2239 2240 s_i = cb->args[4]; 2241 s_fa = cb->args[5]; 2242 i = 0; 2243 2244 /* rcu_read_lock is hold by caller */ 2245 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 2246 struct fib_info *fi = fa->fa_info; 2247 2248 if (i < s_i) 2249 goto next; 2250 2251 i_fa = 0; 2252 2253 if (tb->tb_id != fa->tb_id) 2254 goto next; 2255 2256 if (filter->filter_set) { 2257 if (filter->rt_type && fa->fa_type != filter->rt_type) 2258 goto next; 2259 2260 if ((filter->protocol && 2261 fi->fib_protocol != filter->protocol)) 2262 goto next; 2263 2264 if (filter->dev && 2265 !fib_info_nh_uses_dev(fi, filter->dev)) 2266 goto next; 2267 } 2268 2269 if (filter->dump_routes) { 2270 if (!s_fa) { 2271 struct fib_rt_info fri; 2272 2273 fri.fi = fi; 2274 fri.tb_id = tb->tb_id; 2275 fri.dst = xkey; 2276 fri.dst_len = KEYLENGTH - fa->fa_slen; 2277 fri.tos = fa->fa_tos; 2278 fri.type = fa->fa_type; 2279 fri.offload = fa->offload; 2280 fri.trap = fa->trap; 2281 err = fib_dump_info(skb, 2282 NETLINK_CB(cb->skb).portid, 2283 cb->nlh->nlmsg_seq, 2284 RTM_NEWROUTE, &fri, flags); 2285 if (err < 0) 2286 goto stop; 2287 } 2288 2289 i_fa++; 2290 } 2291 2292 if (filter->dump_exceptions) { 2293 err = fib_dump_info_fnhe(skb, cb, tb->tb_id, fi, 2294 &i_fa, s_fa, flags); 2295 if (err < 0) 2296 goto stop; 2297 } 2298 2299next: 2300 i++; 2301 } 2302 2303 cb->args[4] = i; 2304 return skb->len; 2305 2306stop: 2307 cb->args[4] = i; 2308 cb->args[5] = i_fa; 2309 return err; 2310} 2311 2312/* rcu_read_lock needs to be hold by caller from readside */ 2313int fib_table_dump(struct fib_table *tb, struct sk_buff *skb, 2314 struct netlink_callback *cb, struct fib_dump_filter *filter) 2315{ 2316 struct trie *t = (struct trie *)tb->tb_data; 2317 struct key_vector *l, *tp = t->kv; 2318 /* Dump starting at last key. 2319 * Note: 0.0.0.0/0 (ie default) is first key. 2320 */ 2321 int count = cb->args[2]; 2322 t_key key = cb->args[3]; 2323 2324 /* First time here, count and key are both always 0. Count > 0 2325 * and key == 0 means the dump has wrapped around and we are done. 2326 */ 2327 if (count && !key) 2328 return skb->len; 2329 2330 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 2331 int err; 2332 2333 err = fn_trie_dump_leaf(l, tb, skb, cb, filter); 2334 if (err < 0) { 2335 cb->args[3] = key; 2336 cb->args[2] = count; 2337 return err; 2338 } 2339 2340 ++count; 2341 key = l->key + 1; 2342 2343 memset(&cb->args[4], 0, 2344 sizeof(cb->args) - 4*sizeof(cb->args[0])); 2345 2346 /* stop loop if key wrapped back to 0 */ 2347 if (key < l->key) 2348 break; 2349 } 2350 2351 cb->args[3] = key; 2352 cb->args[2] = count; 2353 2354 return skb->len; 2355} 2356 2357void __init fib_trie_init(void) 2358{ 2359 fn_alias_kmem = kmem_cache_create("ip_fib_alias", 2360 sizeof(struct fib_alias), 2361 0, SLAB_PANIC, NULL); 2362 2363 trie_leaf_kmem = kmem_cache_create("ip_fib_trie", 2364 LEAF_SIZE, 2365 0, SLAB_PANIC, NULL); 2366} 2367 2368struct fib_table *fib_trie_table(u32 id, struct fib_table *alias) 2369{ 2370 struct fib_table *tb; 2371 struct trie *t; 2372 size_t sz = sizeof(*tb); 2373 2374 if (!alias) 2375 sz += sizeof(struct trie); 2376 2377 tb = kzalloc(sz, GFP_KERNEL); 2378 if (!tb) 2379 return NULL; 2380 2381 tb->tb_id = id; 2382 tb->tb_num_default = 0; 2383 tb->tb_data = (alias ? alias->__data : tb->__data); 2384 2385 if (alias) 2386 return tb; 2387 2388 t = (struct trie *) tb->tb_data; 2389 t->kv[0].pos = KEYLENGTH; 2390 t->kv[0].slen = KEYLENGTH; 2391#ifdef CONFIG_IP_FIB_TRIE_STATS 2392 t->stats = alloc_percpu(struct trie_use_stats); 2393 if (!t->stats) { 2394 kfree(tb); 2395 tb = NULL; 2396 } 2397#endif 2398 2399 return tb; 2400} 2401 2402#ifdef CONFIG_PROC_FS 2403/* Depth first Trie walk iterator */ 2404struct fib_trie_iter { 2405 struct seq_net_private p; 2406 struct fib_table *tb; 2407 struct key_vector *tnode; 2408 unsigned int index; 2409 unsigned int depth; 2410}; 2411 2412static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter) 2413{ 2414 unsigned long cindex = iter->index; 2415 struct key_vector *pn = iter->tnode; 2416 t_key pkey; 2417 2418 pr_debug("get_next iter={node=%p index=%d depth=%d}\n", 2419 iter->tnode, iter->index, iter->depth); 2420 2421 while (!IS_TRIE(pn)) { 2422 while (cindex < child_length(pn)) { 2423 struct key_vector *n = get_child_rcu(pn, cindex++); 2424 2425 if (!n) 2426 continue; 2427 2428 if (IS_LEAF(n)) { 2429 iter->tnode = pn; 2430 iter->index = cindex; 2431 } else { 2432 /* push down one level */ 2433 iter->tnode = n; 2434 iter->index = 0; 2435 ++iter->depth; 2436 } 2437 2438 return n; 2439 } 2440 2441 /* Current node exhausted, pop back up */ 2442 pkey = pn->key; 2443 pn = node_parent_rcu(pn); 2444 cindex = get_index(pkey, pn) + 1; 2445 --iter->depth; 2446 } 2447 2448 /* record root node so further searches know we are done */ 2449 iter->tnode = pn; 2450 iter->index = 0; 2451 2452 return NULL; 2453} 2454 2455static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter, 2456 struct trie *t) 2457{ 2458 struct key_vector *n, *pn; 2459 2460 if (!t) 2461 return NULL; 2462 2463 pn = t->kv; 2464 n = rcu_dereference(pn->tnode[0]); 2465 if (!n) 2466 return NULL; 2467 2468 if (IS_TNODE(n)) { 2469 iter->tnode = n; 2470 iter->index = 0; 2471 iter->depth = 1; 2472 } else { 2473 iter->tnode = pn; 2474 iter->index = 0; 2475 iter->depth = 0; 2476 } 2477 2478 return n; 2479} 2480 2481static void trie_collect_stats(struct trie *t, struct trie_stat *s) 2482{ 2483 struct key_vector *n; 2484 struct fib_trie_iter iter; 2485 2486 memset(s, 0, sizeof(*s)); 2487 2488 rcu_read_lock(); 2489 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) { 2490 if (IS_LEAF(n)) { 2491 struct fib_alias *fa; 2492 2493 s->leaves++; 2494 s->totdepth += iter.depth; 2495 if (iter.depth > s->maxdepth) 2496 s->maxdepth = iter.depth; 2497 2498 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) 2499 ++s->prefixes; 2500 } else { 2501 s->tnodes++; 2502 if (n->bits < MAX_STAT_DEPTH) 2503 s->nodesizes[n->bits]++; 2504 s->nullpointers += tn_info(n)->empty_children; 2505 } 2506 } 2507 rcu_read_unlock(); 2508} 2509 2510/* 2511 * This outputs /proc/net/fib_triestats 2512 */ 2513static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat) 2514{ 2515 unsigned int i, max, pointers, bytes, avdepth; 2516 2517 if (stat->leaves) 2518 avdepth = stat->totdepth*100 / stat->leaves; 2519 else 2520 avdepth = 0; 2521 2522 seq_printf(seq, "\tAver depth: %u.%02d\n", 2523 avdepth / 100, avdepth % 100); 2524 seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth); 2525 2526 seq_printf(seq, "\tLeaves: %u\n", stat->leaves); 2527 bytes = LEAF_SIZE * stat->leaves; 2528 2529 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes); 2530 bytes += sizeof(struct fib_alias) * stat->prefixes; 2531 2532 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes); 2533 bytes += TNODE_SIZE(0) * stat->tnodes; 2534 2535 max = MAX_STAT_DEPTH; 2536 while (max > 0 && stat->nodesizes[max-1] == 0) 2537 max--; 2538 2539 pointers = 0; 2540 for (i = 1; i < max; i++) 2541 if (stat->nodesizes[i] != 0) { 2542 seq_printf(seq, " %u: %u", i, stat->nodesizes[i]); 2543 pointers += (1<<i) * stat->nodesizes[i]; 2544 } 2545 seq_putc(seq, '\n'); 2546 seq_printf(seq, "\tPointers: %u\n", pointers); 2547 2548 bytes += sizeof(struct key_vector *) * pointers; 2549 seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers); 2550 seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024); 2551} 2552 2553#ifdef CONFIG_IP_FIB_TRIE_STATS 2554static void trie_show_usage(struct seq_file *seq, 2555 const struct trie_use_stats __percpu *stats) 2556{ 2557 struct trie_use_stats s = { 0 }; 2558 int cpu; 2559 2560 /* loop through all of the CPUs and gather up the stats */ 2561 for_each_possible_cpu(cpu) { 2562 const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu); 2563 2564 s.gets += pcpu->gets; 2565 s.backtrack += pcpu->backtrack; 2566 s.semantic_match_passed += pcpu->semantic_match_passed; 2567 s.semantic_match_miss += pcpu->semantic_match_miss; 2568 s.null_node_hit += pcpu->null_node_hit; 2569 s.resize_node_skipped += pcpu->resize_node_skipped; 2570 } 2571 2572 seq_printf(seq, "\nCounters:\n---------\n"); 2573 seq_printf(seq, "gets = %u\n", s.gets); 2574 seq_printf(seq, "backtracks = %u\n", s.backtrack); 2575 seq_printf(seq, "semantic match passed = %u\n", 2576 s.semantic_match_passed); 2577 seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss); 2578 seq_printf(seq, "null node hit= %u\n", s.null_node_hit); 2579 seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped); 2580} 2581#endif /* CONFIG_IP_FIB_TRIE_STATS */ 2582 2583static void fib_table_print(struct seq_file *seq, struct fib_table *tb) 2584{ 2585 if (tb->tb_id == RT_TABLE_LOCAL) 2586 seq_puts(seq, "Local:\n"); 2587 else if (tb->tb_id == RT_TABLE_MAIN) 2588 seq_puts(seq, "Main:\n"); 2589 else 2590 seq_printf(seq, "Id %d:\n", tb->tb_id); 2591} 2592 2593 2594static int fib_triestat_seq_show(struct seq_file *seq, void *v) 2595{ 2596 struct net *net = (struct net *)seq->private; 2597 unsigned int h; 2598 2599 seq_printf(seq, 2600 "Basic info: size of leaf:" 2601 " %zd bytes, size of tnode: %zd bytes.\n", 2602 LEAF_SIZE, TNODE_SIZE(0)); 2603 2604 rcu_read_lock(); 2605 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2606 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2607 struct fib_table *tb; 2608 2609 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2610 struct trie *t = (struct trie *) tb->tb_data; 2611 struct trie_stat stat; 2612 2613 if (!t) 2614 continue; 2615 2616 fib_table_print(seq, tb); 2617 2618 trie_collect_stats(t, &stat); 2619 trie_show_stats(seq, &stat); 2620#ifdef CONFIG_IP_FIB_TRIE_STATS 2621 trie_show_usage(seq, t->stats); 2622#endif 2623 } 2624 cond_resched_rcu(); 2625 } 2626 rcu_read_unlock(); 2627 2628 return 0; 2629} 2630 2631static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos) 2632{ 2633 struct fib_trie_iter *iter = seq->private; 2634 struct net *net = seq_file_net(seq); 2635 loff_t idx = 0; 2636 unsigned int h; 2637 2638 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2639 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2640 struct fib_table *tb; 2641 2642 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2643 struct key_vector *n; 2644 2645 for (n = fib_trie_get_first(iter, 2646 (struct trie *) tb->tb_data); 2647 n; n = fib_trie_get_next(iter)) 2648 if (pos == idx++) { 2649 iter->tb = tb; 2650 return n; 2651 } 2652 } 2653 } 2654 2655 return NULL; 2656} 2657 2658static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos) 2659 __acquires(RCU) 2660{ 2661 rcu_read_lock(); 2662 return fib_trie_get_idx(seq, *pos); 2663} 2664 2665static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2666{ 2667 struct fib_trie_iter *iter = seq->private; 2668 struct net *net = seq_file_net(seq); 2669 struct fib_table *tb = iter->tb; 2670 struct hlist_node *tb_node; 2671 unsigned int h; 2672 struct key_vector *n; 2673 2674 ++*pos; 2675 /* next node in same table */ 2676 n = fib_trie_get_next(iter); 2677 if (n) 2678 return n; 2679 2680 /* walk rest of this hash chain */ 2681 h = tb->tb_id & (FIB_TABLE_HASHSZ - 1); 2682 while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) { 2683 tb = hlist_entry(tb_node, struct fib_table, tb_hlist); 2684 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data); 2685 if (n) 2686 goto found; 2687 } 2688 2689 /* new hash chain */ 2690 while (++h < FIB_TABLE_HASHSZ) { 2691 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2692 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2693 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data); 2694 if (n) 2695 goto found; 2696 } 2697 } 2698 return NULL; 2699 2700found: 2701 iter->tb = tb; 2702 return n; 2703} 2704 2705static void fib_trie_seq_stop(struct seq_file *seq, void *v) 2706 __releases(RCU) 2707{ 2708 rcu_read_unlock(); 2709} 2710 2711static void seq_indent(struct seq_file *seq, int n) 2712{ 2713 while (n-- > 0) 2714 seq_puts(seq, " "); 2715} 2716 2717static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s) 2718{ 2719 switch (s) { 2720 case RT_SCOPE_UNIVERSE: return "universe"; 2721 case RT_SCOPE_SITE: return "site"; 2722 case RT_SCOPE_LINK: return "link"; 2723 case RT_SCOPE_HOST: return "host"; 2724 case RT_SCOPE_NOWHERE: return "nowhere"; 2725 default: 2726 snprintf(buf, len, "scope=%d", s); 2727 return buf; 2728 } 2729} 2730 2731static const char *const rtn_type_names[__RTN_MAX] = { 2732 [RTN_UNSPEC] = "UNSPEC", 2733 [RTN_UNICAST] = "UNICAST", 2734 [RTN_LOCAL] = "LOCAL", 2735 [RTN_BROADCAST] = "BROADCAST", 2736 [RTN_ANYCAST] = "ANYCAST", 2737 [RTN_MULTICAST] = "MULTICAST", 2738 [RTN_BLACKHOLE] = "BLACKHOLE", 2739 [RTN_UNREACHABLE] = "UNREACHABLE", 2740 [RTN_PROHIBIT] = "PROHIBIT", 2741 [RTN_THROW] = "THROW", 2742 [RTN_NAT] = "NAT", 2743 [RTN_XRESOLVE] = "XRESOLVE", 2744}; 2745 2746static inline const char *rtn_type(char *buf, size_t len, unsigned int t) 2747{ 2748 if (t < __RTN_MAX && rtn_type_names[t]) 2749 return rtn_type_names[t]; 2750 snprintf(buf, len, "type %u", t); 2751 return buf; 2752} 2753 2754/* Pretty print the trie */ 2755static int fib_trie_seq_show(struct seq_file *seq, void *v) 2756{ 2757 const struct fib_trie_iter *iter = seq->private; 2758 struct key_vector *n = v; 2759 2760 if (IS_TRIE(node_parent_rcu(n))) 2761 fib_table_print(seq, iter->tb); 2762 2763 if (IS_TNODE(n)) { 2764 __be32 prf = htonl(n->key); 2765 2766 seq_indent(seq, iter->depth-1); 2767 seq_printf(seq, " +-- %pI4/%zu %u %u %u\n", 2768 &prf, KEYLENGTH - n->pos - n->bits, n->bits, 2769 tn_info(n)->full_children, 2770 tn_info(n)->empty_children); 2771 } else { 2772 __be32 val = htonl(n->key); 2773 struct fib_alias *fa; 2774 2775 seq_indent(seq, iter->depth); 2776 seq_printf(seq, " |-- %pI4\n", &val); 2777 2778 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) { 2779 char buf1[32], buf2[32]; 2780 2781 seq_indent(seq, iter->depth + 1); 2782 seq_printf(seq, " /%zu %s %s", 2783 KEYLENGTH - fa->fa_slen, 2784 rtn_scope(buf1, sizeof(buf1), 2785 fa->fa_info->fib_scope), 2786 rtn_type(buf2, sizeof(buf2), 2787 fa->fa_type)); 2788 if (fa->fa_tos) 2789 seq_printf(seq, " tos=%d", fa->fa_tos); 2790 seq_putc(seq, '\n'); 2791 } 2792 } 2793 2794 return 0; 2795} 2796 2797static const struct seq_operations fib_trie_seq_ops = { 2798 .start = fib_trie_seq_start, 2799 .next = fib_trie_seq_next, 2800 .stop = fib_trie_seq_stop, 2801 .show = fib_trie_seq_show, 2802}; 2803 2804struct fib_route_iter { 2805 struct seq_net_private p; 2806 struct fib_table *main_tb; 2807 struct key_vector *tnode; 2808 loff_t pos; 2809 t_key key; 2810}; 2811 2812static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter, 2813 loff_t pos) 2814{ 2815 struct key_vector *l, **tp = &iter->tnode; 2816 t_key key; 2817 2818 /* use cached location of previously found key */ 2819 if (iter->pos > 0 && pos >= iter->pos) { 2820 key = iter->key; 2821 } else { 2822 iter->pos = 1; 2823 key = 0; 2824 } 2825 2826 pos -= iter->pos; 2827 2828 while ((l = leaf_walk_rcu(tp, key)) && (pos-- > 0)) { 2829 key = l->key + 1; 2830 iter->pos++; 2831 l = NULL; 2832 2833 /* handle unlikely case of a key wrap */ 2834 if (!key) 2835 break; 2836 } 2837 2838 if (l) 2839 iter->key = l->key; /* remember it */ 2840 else 2841 iter->pos = 0; /* forget it */ 2842 2843 return l; 2844} 2845 2846static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos) 2847 __acquires(RCU) 2848{ 2849 struct fib_route_iter *iter = seq->private; 2850 struct fib_table *tb; 2851 struct trie *t; 2852 2853 rcu_read_lock(); 2854 2855 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN); 2856 if (!tb) 2857 return NULL; 2858 2859 iter->main_tb = tb; 2860 t = (struct trie *)tb->tb_data; 2861 iter->tnode = t->kv; 2862 2863 if (*pos != 0) 2864 return fib_route_get_idx(iter, *pos); 2865 2866 iter->pos = 0; 2867 iter->key = KEY_MAX; 2868 2869 return SEQ_START_TOKEN; 2870} 2871 2872static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2873{ 2874 struct fib_route_iter *iter = seq->private; 2875 struct key_vector *l = NULL; 2876 t_key key = iter->key + 1; 2877 2878 ++*pos; 2879 2880 /* only allow key of 0 for start of sequence */ 2881 if ((v == SEQ_START_TOKEN) || key) 2882 l = leaf_walk_rcu(&iter->tnode, key); 2883 2884 if (l) { 2885 iter->key = l->key; 2886 iter->pos++; 2887 } else { 2888 iter->pos = 0; 2889 } 2890 2891 return l; 2892} 2893 2894static void fib_route_seq_stop(struct seq_file *seq, void *v) 2895 __releases(RCU) 2896{ 2897 rcu_read_unlock(); 2898} 2899 2900static unsigned int fib_flag_trans(int type, __be32 mask, struct fib_info *fi) 2901{ 2902 unsigned int flags = 0; 2903 2904 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT) 2905 flags = RTF_REJECT; 2906 if (fi) { 2907 const struct fib_nh_common *nhc = fib_info_nhc(fi, 0); 2908 2909 if (nhc->nhc_gw.ipv4) 2910 flags |= RTF_GATEWAY; 2911 } 2912 if (mask == htonl(0xFFFFFFFF)) 2913 flags |= RTF_HOST; 2914 flags |= RTF_UP; 2915 return flags; 2916} 2917 2918/* 2919 * This outputs /proc/net/route. 2920 * The format of the file is not supposed to be changed 2921 * and needs to be same as fib_hash output to avoid breaking 2922 * legacy utilities 2923 */ 2924static int fib_route_seq_show(struct seq_file *seq, void *v) 2925{ 2926 struct fib_route_iter *iter = seq->private; 2927 struct fib_table *tb = iter->main_tb; 2928 struct fib_alias *fa; 2929 struct key_vector *l = v; 2930 __be32 prefix; 2931 2932 if (v == SEQ_START_TOKEN) { 2933 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway " 2934 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU" 2935 "\tWindow\tIRTT"); 2936 return 0; 2937 } 2938 2939 prefix = htonl(l->key); 2940 2941 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 2942 struct fib_info *fi = fa->fa_info; 2943 __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen); 2944 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi); 2945 2946 if ((fa->fa_type == RTN_BROADCAST) || 2947 (fa->fa_type == RTN_MULTICAST)) 2948 continue; 2949 2950 if (fa->tb_id != tb->tb_id) 2951 continue; 2952 2953 seq_setwidth(seq, 127); 2954 2955 if (fi) { 2956 struct fib_nh_common *nhc = fib_info_nhc(fi, 0); 2957 __be32 gw = 0; 2958 2959 if (nhc->nhc_gw_family == AF_INET) 2960 gw = nhc->nhc_gw.ipv4; 2961 2962 seq_printf(seq, 2963 "%s\t%08X\t%08X\t%04X\t%d\t%u\t" 2964 "%d\t%08X\t%d\t%u\t%u", 2965 nhc->nhc_dev ? nhc->nhc_dev->name : "*", 2966 prefix, gw, flags, 0, 0, 2967 fi->fib_priority, 2968 mask, 2969 (fi->fib_advmss ? 2970 fi->fib_advmss + 40 : 0), 2971 fi->fib_window, 2972 fi->fib_rtt >> 3); 2973 } else { 2974 seq_printf(seq, 2975 "*\t%08X\t%08X\t%04X\t%d\t%u\t" 2976 "%d\t%08X\t%d\t%u\t%u", 2977 prefix, 0, flags, 0, 0, 0, 2978 mask, 0, 0, 0); 2979 } 2980 seq_pad(seq, '\n'); 2981 } 2982 2983 return 0; 2984} 2985 2986static const struct seq_operations fib_route_seq_ops = { 2987 .start = fib_route_seq_start, 2988 .next = fib_route_seq_next, 2989 .stop = fib_route_seq_stop, 2990 .show = fib_route_seq_show, 2991}; 2992 2993int __net_init fib_proc_init(struct net *net) 2994{ 2995 if (!proc_create_net("fib_trie", 0444, net->proc_net, &fib_trie_seq_ops, 2996 sizeof(struct fib_trie_iter))) 2997 goto out1; 2998 2999 if (!proc_create_net_single("fib_triestat", 0444, net->proc_net, 3000 fib_triestat_seq_show, NULL)) 3001 goto out2; 3002 3003 if (!proc_create_net("route", 0444, net->proc_net, &fib_route_seq_ops, 3004 sizeof(struct fib_route_iter))) 3005 goto out3; 3006 3007 return 0; 3008 3009out3: 3010 remove_proc_entry("fib_triestat", net->proc_net); 3011out2: 3012 remove_proc_entry("fib_trie", net->proc_net); 3013out1: 3014 return -ENOMEM; 3015} 3016 3017void __net_exit fib_proc_exit(struct net *net) 3018{ 3019 remove_proc_entry("fib_trie", net->proc_net); 3020 remove_proc_entry("fib_triestat", net->proc_net); 3021 remove_proc_entry("route", net->proc_net); 3022} 3023 3024#endif /* CONFIG_PROC_FS */ 3025