1 /* 2 * This program is free software; you can redistribute it and/or 3 * modify it under the terms of the GNU General Public License 4 * as published by the Free Software Foundation; either version 5 * 2 of the License, or (at your option) any later version. 6 * 7 * Robert Olsson <robert.olsson@its.uu.se> Uppsala Universitet 8 * & Swedish University of Agricultural Sciences. 9 * 10 * Jens Laas <jens.laas@data.slu.se> Swedish University of 11 * Agricultural Sciences. 12 * 13 * Hans Liss <hans.liss@its.uu.se> Uppsala Universitet 14 * 15 * This work is based on the LPC-trie which is originally described in: 16 * 17 * An experimental study of compression methods for dynamic tries 18 * Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002. 19 * http://www.csc.kth.se/~snilsson/software/dyntrie2/ 20 * 21 * 22 * IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson 23 * IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999 24 * 25 * 26 * Code from fib_hash has been reused which includes the following header: 27 * 28 * 29 * INET An implementation of the TCP/IP protocol suite for the LINUX 30 * operating system. INET is implemented using the BSD Socket 31 * interface as the means of communication with the user level. 32 * 33 * IPv4 FIB: lookup engine and maintenance routines. 34 * 35 * 36 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 37 * 38 * This program is free software; you can redistribute it and/or 39 * modify it under the terms of the GNU General Public License 40 * as published by the Free Software Foundation; either version 41 * 2 of the License, or (at your option) any later version. 42 * 43 * Substantial contributions to this work comes from: 44 * 45 * David S. Miller, <davem@davemloft.net> 46 * Stephen Hemminger <shemminger@osdl.org> 47 * Paul E. McKenney <paulmck@us.ibm.com> 48 * Patrick McHardy <kaber@trash.net> 49 */ 50 51 #define VERSION "0.409" 52 53 #include <asm/uaccess.h> 54 #include <linux/bitops.h> 55 #include <linux/types.h> 56 #include <linux/kernel.h> 57 #include <linux/mm.h> 58 #include <linux/string.h> 59 #include <linux/socket.h> 60 #include <linux/sockios.h> 61 #include <linux/errno.h> 62 #include <linux/in.h> 63 #include <linux/inet.h> 64 #include <linux/inetdevice.h> 65 #include <linux/netdevice.h> 66 #include <linux/if_arp.h> 67 #include <linux/proc_fs.h> 68 #include <linux/rcupdate.h> 69 #include <linux/skbuff.h> 70 #include <linux/netlink.h> 71 #include <linux/init.h> 72 #include <linux/list.h> 73 #include <linux/slab.h> 74 #include <linux/export.h> 75 #include <linux/vmalloc.h> 76 #include <net/net_namespace.h> 77 #include <net/ip.h> 78 #include <net/protocol.h> 79 #include <net/route.h> 80 #include <net/tcp.h> 81 #include <net/sock.h> 82 #include <net/ip_fib.h> 83 #include <net/switchdev.h> 84 #include "fib_lookup.h" 85 86 #define MAX_STAT_DEPTH 32 87 88 #define KEYLENGTH (8*sizeof(t_key)) 89 #define KEY_MAX ((t_key)~0) 90 91 typedef unsigned int t_key; 92 93 #define IS_TRIE(n) ((n)->pos >= KEYLENGTH) 94 #define IS_TNODE(n) ((n)->bits) 95 #define IS_LEAF(n) (!(n)->bits) 96 97 struct key_vector { 98 t_key key; 99 unsigned char pos; /* 2log(KEYLENGTH) bits needed */ 100 unsigned char bits; /* 2log(KEYLENGTH) bits needed */ 101 unsigned char slen; 102 union { 103 /* This list pointer if valid if (pos | bits) == 0 (LEAF) */ 104 struct hlist_head leaf; 105 /* This array is valid if (pos | bits) > 0 (TNODE) */ 106 struct key_vector __rcu *tnode[0]; 107 }; 108 }; 109 110 struct tnode { 111 struct rcu_head rcu; 112 t_key empty_children; /* KEYLENGTH bits needed */ 113 t_key full_children; /* KEYLENGTH bits needed */ 114 struct key_vector __rcu *parent; 115 struct key_vector kv[1]; 116 #define tn_bits kv[0].bits 117 }; 118 119 #define TNODE_SIZE(n) offsetof(struct tnode, kv[0].tnode[n]) 120 #define LEAF_SIZE TNODE_SIZE(1) 121 122 #ifdef CONFIG_IP_FIB_TRIE_STATS 123 struct trie_use_stats { 124 unsigned int gets; 125 unsigned int backtrack; 126 unsigned int semantic_match_passed; 127 unsigned int semantic_match_miss; 128 unsigned int null_node_hit; 129 unsigned int resize_node_skipped; 130 }; 131 #endif 132 133 struct trie_stat { 134 unsigned int totdepth; 135 unsigned int maxdepth; 136 unsigned int tnodes; 137 unsigned int leaves; 138 unsigned int nullpointers; 139 unsigned int prefixes; 140 unsigned int nodesizes[MAX_STAT_DEPTH]; 141 }; 142 143 struct trie { 144 struct key_vector kv[1]; 145 #ifdef CONFIG_IP_FIB_TRIE_STATS 146 struct trie_use_stats __percpu *stats; 147 #endif 148 }; 149 150 static struct key_vector *resize(struct trie *t, struct key_vector *tn); 151 static size_t tnode_free_size; 152 153 /* 154 * synchronize_rcu after call_rcu for that many pages; it should be especially 155 * useful before resizing the root node with PREEMPT_NONE configs; the value was 156 * obtained experimentally, aiming to avoid visible slowdown. 157 */ 158 static const int sync_pages = 128; 159 160 static struct kmem_cache *fn_alias_kmem __read_mostly; 161 static struct kmem_cache *trie_leaf_kmem __read_mostly; 162 163 static inline struct tnode *tn_info(struct key_vector *kv) 164 { 165 return container_of(kv, struct tnode, kv[0]); 166 } 167 168 /* caller must hold RTNL */ 169 #define node_parent(tn) rtnl_dereference(tn_info(tn)->parent) 170 #define get_child(tn, i) rtnl_dereference((tn)->tnode[i]) 171 172 /* caller must hold RCU read lock or RTNL */ 173 #define node_parent_rcu(tn) rcu_dereference_rtnl(tn_info(tn)->parent) 174 #define get_child_rcu(tn, i) rcu_dereference_rtnl((tn)->tnode[i]) 175 176 /* wrapper for rcu_assign_pointer */ 177 static inline void node_set_parent(struct key_vector *n, struct key_vector *tp) 178 { 179 if (n) 180 rcu_assign_pointer(tn_info(n)->parent, tp); 181 } 182 183 #define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER(tn_info(n)->parent, p) 184 185 /* This provides us with the number of children in this node, in the case of a 186 * leaf this will return 0 meaning none of the children are accessible. 187 */ 188 static inline unsigned long child_length(const struct key_vector *tn) 189 { 190 return (1ul << tn->bits) & ~(1ul); 191 } 192 193 #define get_cindex(key, kv) (((key) ^ (kv)->key) >> (kv)->pos) 194 195 static inline unsigned long get_index(t_key key, struct key_vector *kv) 196 { 197 unsigned long index = key ^ kv->key; 198 199 if ((BITS_PER_LONG <= KEYLENGTH) && (KEYLENGTH == kv->pos)) 200 return 0; 201 202 return index >> kv->pos; 203 } 204 205 /* To understand this stuff, an understanding of keys and all their bits is 206 * necessary. Every node in the trie has a key associated with it, but not 207 * all of the bits in that key are significant. 208 * 209 * Consider a node 'n' and its parent 'tp'. 210 * 211 * If n is a leaf, every bit in its key is significant. Its presence is 212 * necessitated by path compression, since during a tree traversal (when 213 * searching for a leaf - unless we are doing an insertion) we will completely 214 * ignore all skipped bits we encounter. Thus we need to verify, at the end of 215 * a potentially successful search, that we have indeed been walking the 216 * correct key path. 217 * 218 * Note that we can never "miss" the correct key in the tree if present by 219 * following the wrong path. Path compression ensures that segments of the key 220 * that are the same for all keys with a given prefix are skipped, but the 221 * skipped part *is* identical for each node in the subtrie below the skipped 222 * bit! trie_insert() in this implementation takes care of that. 223 * 224 * if n is an internal node - a 'tnode' here, the various parts of its key 225 * have many different meanings. 226 * 227 * Example: 228 * _________________________________________________________________ 229 * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C | 230 * ----------------------------------------------------------------- 231 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 232 * 233 * _________________________________________________________________ 234 * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u | 235 * ----------------------------------------------------------------- 236 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 237 * 238 * tp->pos = 22 239 * tp->bits = 3 240 * n->pos = 13 241 * n->bits = 4 242 * 243 * First, let's just ignore the bits that come before the parent tp, that is 244 * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this 245 * point we do not use them for anything. 246 * 247 * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the 248 * index into the parent's child array. That is, they will be used to find 249 * 'n' among tp's children. 250 * 251 * The bits from (n->pos + n->bits) to (tn->pos - 1) - "S" - are skipped bits 252 * for the node n. 253 * 254 * All the bits we have seen so far are significant to the node n. The rest 255 * of the bits are really not needed or indeed known in n->key. 256 * 257 * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into 258 * n's child array, and will of course be different for each child. 259 * 260 * The rest of the bits, from 0 to (n->pos + n->bits), are completely unknown 261 * at this point. 262 */ 263 264 static const int halve_threshold = 25; 265 static const int inflate_threshold = 50; 266 static const int halve_threshold_root = 15; 267 static const int inflate_threshold_root = 30; 268 269 static void __alias_free_mem(struct rcu_head *head) 270 { 271 struct fib_alias *fa = container_of(head, struct fib_alias, rcu); 272 kmem_cache_free(fn_alias_kmem, fa); 273 } 274 275 static inline void alias_free_mem_rcu(struct fib_alias *fa) 276 { 277 call_rcu(&fa->rcu, __alias_free_mem); 278 } 279 280 #define TNODE_KMALLOC_MAX \ 281 ilog2((PAGE_SIZE - TNODE_SIZE(0)) / sizeof(struct key_vector *)) 282 #define TNODE_VMALLOC_MAX \ 283 ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *)) 284 285 static void __node_free_rcu(struct rcu_head *head) 286 { 287 struct tnode *n = container_of(head, struct tnode, rcu); 288 289 if (!n->tn_bits) 290 kmem_cache_free(trie_leaf_kmem, n); 291 else if (n->tn_bits <= TNODE_KMALLOC_MAX) 292 kfree(n); 293 else 294 vfree(n); 295 } 296 297 #define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu) 298 299 static struct tnode *tnode_alloc(int bits) 300 { 301 size_t size; 302 303 /* verify bits is within bounds */ 304 if (bits > TNODE_VMALLOC_MAX) 305 return NULL; 306 307 /* determine size and verify it is non-zero and didn't overflow */ 308 size = TNODE_SIZE(1ul << bits); 309 310 if (size <= PAGE_SIZE) 311 return kzalloc(size, GFP_KERNEL); 312 else 313 return vzalloc(size); 314 } 315 316 static inline void empty_child_inc(struct key_vector *n) 317 { 318 ++tn_info(n)->empty_children ? : ++tn_info(n)->full_children; 319 } 320 321 static inline void empty_child_dec(struct key_vector *n) 322 { 323 tn_info(n)->empty_children-- ? : tn_info(n)->full_children--; 324 } 325 326 static struct key_vector *leaf_new(t_key key, struct fib_alias *fa) 327 { 328 struct key_vector *l; 329 struct tnode *kv; 330 331 kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL); 332 if (!kv) 333 return NULL; 334 335 /* initialize key vector */ 336 l = kv->kv; 337 l->key = key; 338 l->pos = 0; 339 l->bits = 0; 340 l->slen = fa->fa_slen; 341 342 /* link leaf to fib alias */ 343 INIT_HLIST_HEAD(&l->leaf); 344 hlist_add_head(&fa->fa_list, &l->leaf); 345 346 return l; 347 } 348 349 static struct key_vector *tnode_new(t_key key, int pos, int bits) 350 { 351 unsigned int shift = pos + bits; 352 struct key_vector *tn; 353 struct tnode *tnode; 354 355 /* verify bits and pos their msb bits clear and values are valid */ 356 BUG_ON(!bits || (shift > KEYLENGTH)); 357 358 tnode = tnode_alloc(bits); 359 if (!tnode) 360 return NULL; 361 362 pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0), 363 sizeof(struct key_vector *) << bits); 364 365 if (bits == KEYLENGTH) 366 tnode->full_children = 1; 367 else 368 tnode->empty_children = 1ul << bits; 369 370 tn = tnode->kv; 371 tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0; 372 tn->pos = pos; 373 tn->bits = bits; 374 tn->slen = pos; 375 376 return tn; 377 } 378 379 /* Check whether a tnode 'n' is "full", i.e. it is an internal node 380 * and no bits are skipped. See discussion in dyntree paper p. 6 381 */ 382 static inline int tnode_full(struct key_vector *tn, struct key_vector *n) 383 { 384 return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n); 385 } 386 387 /* Add a child at position i overwriting the old value. 388 * Update the value of full_children and empty_children. 389 */ 390 static void put_child(struct key_vector *tn, unsigned long i, 391 struct key_vector *n) 392 { 393 struct key_vector *chi = get_child(tn, i); 394 int isfull, wasfull; 395 396 BUG_ON(i >= child_length(tn)); 397 398 /* update emptyChildren, overflow into fullChildren */ 399 if (!n && chi) 400 empty_child_inc(tn); 401 if (n && !chi) 402 empty_child_dec(tn); 403 404 /* update fullChildren */ 405 wasfull = tnode_full(tn, chi); 406 isfull = tnode_full(tn, n); 407 408 if (wasfull && !isfull) 409 tn_info(tn)->full_children--; 410 else if (!wasfull && isfull) 411 tn_info(tn)->full_children++; 412 413 if (n && (tn->slen < n->slen)) 414 tn->slen = n->slen; 415 416 rcu_assign_pointer(tn->tnode[i], n); 417 } 418 419 static void update_children(struct key_vector *tn) 420 { 421 unsigned long i; 422 423 /* update all of the child parent pointers */ 424 for (i = child_length(tn); i;) { 425 struct key_vector *inode = get_child(tn, --i); 426 427 if (!inode) 428 continue; 429 430 /* Either update the children of a tnode that 431 * already belongs to us or update the child 432 * to point to ourselves. 433 */ 434 if (node_parent(inode) == tn) 435 update_children(inode); 436 else 437 node_set_parent(inode, tn); 438 } 439 } 440 441 static inline void put_child_root(struct key_vector *tp, t_key key, 442 struct key_vector *n) 443 { 444 if (IS_TRIE(tp)) 445 rcu_assign_pointer(tp->tnode[0], n); 446 else 447 put_child(tp, get_index(key, tp), n); 448 } 449 450 static inline void tnode_free_init(struct key_vector *tn) 451 { 452 tn_info(tn)->rcu.next = NULL; 453 } 454 455 static inline void tnode_free_append(struct key_vector *tn, 456 struct key_vector *n) 457 { 458 tn_info(n)->rcu.next = tn_info(tn)->rcu.next; 459 tn_info(tn)->rcu.next = &tn_info(n)->rcu; 460 } 461 462 static void tnode_free(struct key_vector *tn) 463 { 464 struct callback_head *head = &tn_info(tn)->rcu; 465 466 while (head) { 467 head = head->next; 468 tnode_free_size += TNODE_SIZE(1ul << tn->bits); 469 node_free(tn); 470 471 tn = container_of(head, struct tnode, rcu)->kv; 472 } 473 474 if (tnode_free_size >= PAGE_SIZE * sync_pages) { 475 tnode_free_size = 0; 476 synchronize_rcu(); 477 } 478 } 479 480 static struct key_vector *replace(struct trie *t, 481 struct key_vector *oldtnode, 482 struct key_vector *tn) 483 { 484 struct key_vector *tp = node_parent(oldtnode); 485 unsigned long i; 486 487 /* setup the parent pointer out of and back into this node */ 488 NODE_INIT_PARENT(tn, tp); 489 put_child_root(tp, tn->key, tn); 490 491 /* update all of the child parent pointers */ 492 update_children(tn); 493 494 /* all pointers should be clean so we are done */ 495 tnode_free(oldtnode); 496 497 /* resize children now that oldtnode is freed */ 498 for (i = child_length(tn); i;) { 499 struct key_vector *inode = get_child(tn, --i); 500 501 /* resize child node */ 502 if (tnode_full(tn, inode)) 503 tn = resize(t, inode); 504 } 505 506 return tp; 507 } 508 509 static struct key_vector *inflate(struct trie *t, 510 struct key_vector *oldtnode) 511 { 512 struct key_vector *tn; 513 unsigned long i; 514 t_key m; 515 516 pr_debug("In inflate\n"); 517 518 tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1); 519 if (!tn) 520 goto notnode; 521 522 /* prepare oldtnode to be freed */ 523 tnode_free_init(oldtnode); 524 525 /* Assemble all of the pointers in our cluster, in this case that 526 * represents all of the pointers out of our allocated nodes that 527 * point to existing tnodes and the links between our allocated 528 * nodes. 529 */ 530 for (i = child_length(oldtnode), m = 1u << tn->pos; i;) { 531 struct key_vector *inode = get_child(oldtnode, --i); 532 struct key_vector *node0, *node1; 533 unsigned long j, k; 534 535 /* An empty child */ 536 if (!inode) 537 continue; 538 539 /* A leaf or an internal node with skipped bits */ 540 if (!tnode_full(oldtnode, inode)) { 541 put_child(tn, get_index(inode->key, tn), inode); 542 continue; 543 } 544 545 /* drop the node in the old tnode free list */ 546 tnode_free_append(oldtnode, inode); 547 548 /* An internal node with two children */ 549 if (inode->bits == 1) { 550 put_child(tn, 2 * i + 1, get_child(inode, 1)); 551 put_child(tn, 2 * i, get_child(inode, 0)); 552 continue; 553 } 554 555 /* We will replace this node 'inode' with two new 556 * ones, 'node0' and 'node1', each with half of the 557 * original children. The two new nodes will have 558 * a position one bit further down the key and this 559 * means that the "significant" part of their keys 560 * (see the discussion near the top of this file) 561 * will differ by one bit, which will be "0" in 562 * node0's key and "1" in node1's key. Since we are 563 * moving the key position by one step, the bit that 564 * we are moving away from - the bit at position 565 * (tn->pos) - is the one that will differ between 566 * node0 and node1. So... we synthesize that bit in the 567 * two new keys. 568 */ 569 node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1); 570 if (!node1) 571 goto nomem; 572 node0 = tnode_new(inode->key, inode->pos, inode->bits - 1); 573 574 tnode_free_append(tn, node1); 575 if (!node0) 576 goto nomem; 577 tnode_free_append(tn, node0); 578 579 /* populate child pointers in new nodes */ 580 for (k = child_length(inode), j = k / 2; j;) { 581 put_child(node1, --j, get_child(inode, --k)); 582 put_child(node0, j, get_child(inode, j)); 583 put_child(node1, --j, get_child(inode, --k)); 584 put_child(node0, j, get_child(inode, j)); 585 } 586 587 /* link new nodes to parent */ 588 NODE_INIT_PARENT(node1, tn); 589 NODE_INIT_PARENT(node0, tn); 590 591 /* link parent to nodes */ 592 put_child(tn, 2 * i + 1, node1); 593 put_child(tn, 2 * i, node0); 594 } 595 596 /* setup the parent pointers into and out of this node */ 597 return replace(t, oldtnode, tn); 598 nomem: 599 /* all pointers should be clean so we are done */ 600 tnode_free(tn); 601 notnode: 602 return NULL; 603 } 604 605 static struct key_vector *halve(struct trie *t, 606 struct key_vector *oldtnode) 607 { 608 struct key_vector *tn; 609 unsigned long i; 610 611 pr_debug("In halve\n"); 612 613 tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1); 614 if (!tn) 615 goto notnode; 616 617 /* prepare oldtnode to be freed */ 618 tnode_free_init(oldtnode); 619 620 /* Assemble all of the pointers in our cluster, in this case that 621 * represents all of the pointers out of our allocated nodes that 622 * point to existing tnodes and the links between our allocated 623 * nodes. 624 */ 625 for (i = child_length(oldtnode); i;) { 626 struct key_vector *node1 = get_child(oldtnode, --i); 627 struct key_vector *node0 = get_child(oldtnode, --i); 628 struct key_vector *inode; 629 630 /* At least one of the children is empty */ 631 if (!node1 || !node0) { 632 put_child(tn, i / 2, node1 ? : node0); 633 continue; 634 } 635 636 /* Two nonempty children */ 637 inode = tnode_new(node0->key, oldtnode->pos, 1); 638 if (!inode) 639 goto nomem; 640 tnode_free_append(tn, inode); 641 642 /* initialize pointers out of node */ 643 put_child(inode, 1, node1); 644 put_child(inode, 0, node0); 645 NODE_INIT_PARENT(inode, tn); 646 647 /* link parent to node */ 648 put_child(tn, i / 2, inode); 649 } 650 651 /* setup the parent pointers into and out of this node */ 652 return replace(t, oldtnode, tn); 653 nomem: 654 /* all pointers should be clean so we are done */ 655 tnode_free(tn); 656 notnode: 657 return NULL; 658 } 659 660 static struct key_vector *collapse(struct trie *t, 661 struct key_vector *oldtnode) 662 { 663 struct key_vector *n, *tp; 664 unsigned long i; 665 666 /* scan the tnode looking for that one child that might still exist */ 667 for (n = NULL, i = child_length(oldtnode); !n && i;) 668 n = get_child(oldtnode, --i); 669 670 /* compress one level */ 671 tp = node_parent(oldtnode); 672 put_child_root(tp, oldtnode->key, n); 673 node_set_parent(n, tp); 674 675 /* drop dead node */ 676 node_free(oldtnode); 677 678 return tp; 679 } 680 681 static unsigned char update_suffix(struct key_vector *tn) 682 { 683 unsigned char slen = tn->pos; 684 unsigned long stride, i; 685 686 /* search though the list of children looking for nodes that might 687 * have a suffix greater than the one we currently have. This is 688 * why we start with a stride of 2 since a stride of 1 would 689 * represent the nodes with suffix length equal to tn->pos 690 */ 691 for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) { 692 struct key_vector *n = get_child(tn, i); 693 694 if (!n || (n->slen <= slen)) 695 continue; 696 697 /* update stride and slen based on new value */ 698 stride <<= (n->slen - slen); 699 slen = n->slen; 700 i &= ~(stride - 1); 701 702 /* if slen covers all but the last bit we can stop here 703 * there will be nothing longer than that since only node 704 * 0 and 1 << (bits - 1) could have that as their suffix 705 * length. 706 */ 707 if ((slen + 1) >= (tn->pos + tn->bits)) 708 break; 709 } 710 711 tn->slen = slen; 712 713 return slen; 714 } 715 716 /* From "Implementing a dynamic compressed trie" by Stefan Nilsson of 717 * the Helsinki University of Technology and Matti Tikkanen of Nokia 718 * Telecommunications, page 6: 719 * "A node is doubled if the ratio of non-empty children to all 720 * children in the *doubled* node is at least 'high'." 721 * 722 * 'high' in this instance is the variable 'inflate_threshold'. It 723 * is expressed as a percentage, so we multiply it with 724 * child_length() and instead of multiplying by 2 (since the 725 * child array will be doubled by inflate()) and multiplying 726 * the left-hand side by 100 (to handle the percentage thing) we 727 * multiply the left-hand side by 50. 728 * 729 * The left-hand side may look a bit weird: child_length(tn) 730 * - tn->empty_children is of course the number of non-null children 731 * in the current node. tn->full_children is the number of "full" 732 * children, that is non-null tnodes with a skip value of 0. 733 * All of those will be doubled in the resulting inflated tnode, so 734 * we just count them one extra time here. 735 * 736 * A clearer way to write this would be: 737 * 738 * to_be_doubled = tn->full_children; 739 * not_to_be_doubled = child_length(tn) - tn->empty_children - 740 * tn->full_children; 741 * 742 * new_child_length = child_length(tn) * 2; 743 * 744 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) / 745 * new_child_length; 746 * if (new_fill_factor >= inflate_threshold) 747 * 748 * ...and so on, tho it would mess up the while () loop. 749 * 750 * anyway, 751 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >= 752 * inflate_threshold 753 * 754 * avoid a division: 755 * 100 * (not_to_be_doubled + 2*to_be_doubled) >= 756 * inflate_threshold * new_child_length 757 * 758 * expand not_to_be_doubled and to_be_doubled, and shorten: 759 * 100 * (child_length(tn) - tn->empty_children + 760 * tn->full_children) >= inflate_threshold * new_child_length 761 * 762 * expand new_child_length: 763 * 100 * (child_length(tn) - tn->empty_children + 764 * tn->full_children) >= 765 * inflate_threshold * child_length(tn) * 2 766 * 767 * shorten again: 768 * 50 * (tn->full_children + child_length(tn) - 769 * tn->empty_children) >= inflate_threshold * 770 * child_length(tn) 771 * 772 */ 773 static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn) 774 { 775 unsigned long used = child_length(tn); 776 unsigned long threshold = used; 777 778 /* Keep root node larger */ 779 threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold; 780 used -= tn_info(tn)->empty_children; 781 used += tn_info(tn)->full_children; 782 783 /* if bits == KEYLENGTH then pos = 0, and will fail below */ 784 785 return (used > 1) && tn->pos && ((50 * used) >= threshold); 786 } 787 788 static inline bool should_halve(struct key_vector *tp, struct key_vector *tn) 789 { 790 unsigned long used = child_length(tn); 791 unsigned long threshold = used; 792 793 /* Keep root node larger */ 794 threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold; 795 used -= tn_info(tn)->empty_children; 796 797 /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */ 798 799 return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold); 800 } 801 802 static inline bool should_collapse(struct key_vector *tn) 803 { 804 unsigned long used = child_length(tn); 805 806 used -= tn_info(tn)->empty_children; 807 808 /* account for bits == KEYLENGTH case */ 809 if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children) 810 used -= KEY_MAX; 811 812 /* One child or none, time to drop us from the trie */ 813 return used < 2; 814 } 815 816 #define MAX_WORK 10 817 static struct key_vector *resize(struct trie *t, struct key_vector *tn) 818 { 819 #ifdef CONFIG_IP_FIB_TRIE_STATS 820 struct trie_use_stats __percpu *stats = t->stats; 821 #endif 822 struct key_vector *tp = node_parent(tn); 823 unsigned long cindex = get_index(tn->key, tp); 824 int max_work = MAX_WORK; 825 826 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n", 827 tn, inflate_threshold, halve_threshold); 828 829 /* track the tnode via the pointer from the parent instead of 830 * doing it ourselves. This way we can let RCU fully do its 831 * thing without us interfering 832 */ 833 BUG_ON(tn != get_child(tp, cindex)); 834 835 /* Double as long as the resulting node has a number of 836 * nonempty nodes that are above the threshold. 837 */ 838 while (should_inflate(tp, tn) && max_work) { 839 tp = inflate(t, tn); 840 if (!tp) { 841 #ifdef CONFIG_IP_FIB_TRIE_STATS 842 this_cpu_inc(stats->resize_node_skipped); 843 #endif 844 break; 845 } 846 847 max_work--; 848 tn = get_child(tp, cindex); 849 } 850 851 /* update parent in case inflate failed */ 852 tp = node_parent(tn); 853 854 /* Return if at least one inflate is run */ 855 if (max_work != MAX_WORK) 856 return tp; 857 858 /* Halve as long as the number of empty children in this 859 * node is above threshold. 860 */ 861 while (should_halve(tp, tn) && max_work) { 862 tp = halve(t, tn); 863 if (!tp) { 864 #ifdef CONFIG_IP_FIB_TRIE_STATS 865 this_cpu_inc(stats->resize_node_skipped); 866 #endif 867 break; 868 } 869 870 max_work--; 871 tn = get_child(tp, cindex); 872 } 873 874 /* Only one child remains */ 875 if (should_collapse(tn)) 876 return collapse(t, tn); 877 878 /* update parent in case halve failed */ 879 tp = node_parent(tn); 880 881 /* Return if at least one deflate was run */ 882 if (max_work != MAX_WORK) 883 return tp; 884 885 /* push the suffix length to the parent node */ 886 if (tn->slen > tn->pos) { 887 unsigned char slen = update_suffix(tn); 888 889 if (slen > tp->slen) 890 tp->slen = slen; 891 } 892 893 return tp; 894 } 895 896 static void leaf_pull_suffix(struct key_vector *tp, struct key_vector *l) 897 { 898 while ((tp->slen > tp->pos) && (tp->slen > l->slen)) { 899 if (update_suffix(tp) > l->slen) 900 break; 901 tp = node_parent(tp); 902 } 903 } 904 905 static void leaf_push_suffix(struct key_vector *tn, struct key_vector *l) 906 { 907 /* if this is a new leaf then tn will be NULL and we can sort 908 * out parent suffix lengths as a part of trie_rebalance 909 */ 910 while (tn->slen < l->slen) { 911 tn->slen = l->slen; 912 tn = node_parent(tn); 913 } 914 } 915 916 /* rcu_read_lock needs to be hold by caller from readside */ 917 static struct key_vector *fib_find_node(struct trie *t, 918 struct key_vector **tp, u32 key) 919 { 920 struct key_vector *pn, *n = t->kv; 921 unsigned long index = 0; 922 923 do { 924 pn = n; 925 n = get_child_rcu(n, index); 926 927 if (!n) 928 break; 929 930 index = get_cindex(key, n); 931 932 /* This bit of code is a bit tricky but it combines multiple 933 * checks into a single check. The prefix consists of the 934 * prefix plus zeros for the bits in the cindex. The index 935 * is the difference between the key and this value. From 936 * this we can actually derive several pieces of data. 937 * if (index >= (1ul << bits)) 938 * we have a mismatch in skip bits and failed 939 * else 940 * we know the value is cindex 941 * 942 * This check is safe even if bits == KEYLENGTH due to the 943 * fact that we can only allocate a node with 32 bits if a 944 * long is greater than 32 bits. 945 */ 946 if (index >= (1ul << n->bits)) { 947 n = NULL; 948 break; 949 } 950 951 /* keep searching until we find a perfect match leaf or NULL */ 952 } while (IS_TNODE(n)); 953 954 *tp = pn; 955 956 return n; 957 } 958 959 /* Return the first fib alias matching TOS with 960 * priority less than or equal to PRIO. 961 */ 962 static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen, 963 u8 tos, u32 prio, u32 tb_id) 964 { 965 struct fib_alias *fa; 966 967 if (!fah) 968 return NULL; 969 970 hlist_for_each_entry(fa, fah, fa_list) { 971 if (fa->fa_slen < slen) 972 continue; 973 if (fa->fa_slen != slen) 974 break; 975 if (fa->tb_id > tb_id) 976 continue; 977 if (fa->tb_id != tb_id) 978 break; 979 if (fa->fa_tos > tos) 980 continue; 981 if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos) 982 return fa; 983 } 984 985 return NULL; 986 } 987 988 static void trie_rebalance(struct trie *t, struct key_vector *tn) 989 { 990 while (!IS_TRIE(tn)) 991 tn = resize(t, tn); 992 } 993 994 static int fib_insert_node(struct trie *t, struct key_vector *tp, 995 struct fib_alias *new, t_key key) 996 { 997 struct key_vector *n, *l; 998 999 l = leaf_new(key, new); 1000 if (!l) 1001 goto noleaf; 1002 1003 /* retrieve child from parent node */ 1004 n = get_child(tp, get_index(key, tp)); 1005 1006 /* Case 2: n is a LEAF or a TNODE and the key doesn't match. 1007 * 1008 * Add a new tnode here 1009 * first tnode need some special handling 1010 * leaves us in position for handling as case 3 1011 */ 1012 if (n) { 1013 struct key_vector *tn; 1014 1015 tn = tnode_new(key, __fls(key ^ n->key), 1); 1016 if (!tn) 1017 goto notnode; 1018 1019 /* initialize routes out of node */ 1020 NODE_INIT_PARENT(tn, tp); 1021 put_child(tn, get_index(key, tn) ^ 1, n); 1022 1023 /* start adding routes into the node */ 1024 put_child_root(tp, key, tn); 1025 node_set_parent(n, tn); 1026 1027 /* parent now has a NULL spot where the leaf can go */ 1028 tp = tn; 1029 } 1030 1031 /* Case 3: n is NULL, and will just insert a new leaf */ 1032 NODE_INIT_PARENT(l, tp); 1033 put_child_root(tp, key, l); 1034 trie_rebalance(t, tp); 1035 1036 return 0; 1037 notnode: 1038 node_free(l); 1039 noleaf: 1040 return -ENOMEM; 1041 } 1042 1043 static int fib_insert_alias(struct trie *t, struct key_vector *tp, 1044 struct key_vector *l, struct fib_alias *new, 1045 struct fib_alias *fa, t_key key) 1046 { 1047 if (!l) 1048 return fib_insert_node(t, tp, new, key); 1049 1050 if (fa) { 1051 hlist_add_before_rcu(&new->fa_list, &fa->fa_list); 1052 } else { 1053 struct fib_alias *last; 1054 1055 hlist_for_each_entry(last, &l->leaf, fa_list) { 1056 if (new->fa_slen < last->fa_slen) 1057 break; 1058 if ((new->fa_slen == last->fa_slen) && 1059 (new->tb_id > last->tb_id)) 1060 break; 1061 fa = last; 1062 } 1063 1064 if (fa) 1065 hlist_add_behind_rcu(&new->fa_list, &fa->fa_list); 1066 else 1067 hlist_add_head_rcu(&new->fa_list, &l->leaf); 1068 } 1069 1070 /* if we added to the tail node then we need to update slen */ 1071 if (l->slen < new->fa_slen) { 1072 l->slen = new->fa_slen; 1073 leaf_push_suffix(tp, l); 1074 } 1075 1076 return 0; 1077 } 1078 1079 /* Caller must hold RTNL. */ 1080 int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) 1081 { 1082 struct trie *t = (struct trie *)tb->tb_data; 1083 struct fib_alias *fa, *new_fa; 1084 struct key_vector *l, *tp; 1085 unsigned int nlflags = 0; 1086 struct fib_info *fi; 1087 u8 plen = cfg->fc_dst_len; 1088 u8 slen = KEYLENGTH - plen; 1089 u8 tos = cfg->fc_tos; 1090 u32 key; 1091 int err; 1092 1093 if (plen > KEYLENGTH) 1094 return -EINVAL; 1095 1096 key = ntohl(cfg->fc_dst); 1097 1098 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen); 1099 1100 if ((plen < KEYLENGTH) && (key << plen)) 1101 return -EINVAL; 1102 1103 fi = fib_create_info(cfg); 1104 if (IS_ERR(fi)) { 1105 err = PTR_ERR(fi); 1106 goto err; 1107 } 1108 1109 l = fib_find_node(t, &tp, key); 1110 fa = l ? fib_find_alias(&l->leaf, slen, tos, fi->fib_priority, 1111 tb->tb_id) : NULL; 1112 1113 /* Now fa, if non-NULL, points to the first fib alias 1114 * with the same keys [prefix,tos,priority], if such key already 1115 * exists or to the node before which we will insert new one. 1116 * 1117 * If fa is NULL, we will need to allocate a new one and 1118 * insert to the tail of the section matching the suffix length 1119 * of the new alias. 1120 */ 1121 1122 if (fa && fa->fa_tos == tos && 1123 fa->fa_info->fib_priority == fi->fib_priority) { 1124 struct fib_alias *fa_first, *fa_match; 1125 1126 err = -EEXIST; 1127 if (cfg->fc_nlflags & NLM_F_EXCL) 1128 goto out; 1129 1130 /* We have 2 goals: 1131 * 1. Find exact match for type, scope, fib_info to avoid 1132 * duplicate routes 1133 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it 1134 */ 1135 fa_match = NULL; 1136 fa_first = fa; 1137 hlist_for_each_entry_from(fa, fa_list) { 1138 if ((fa->fa_slen != slen) || 1139 (fa->tb_id != tb->tb_id) || 1140 (fa->fa_tos != tos)) 1141 break; 1142 if (fa->fa_info->fib_priority != fi->fib_priority) 1143 break; 1144 if (fa->fa_type == cfg->fc_type && 1145 fa->fa_info == fi) { 1146 fa_match = fa; 1147 break; 1148 } 1149 } 1150 1151 if (cfg->fc_nlflags & NLM_F_REPLACE) { 1152 struct fib_info *fi_drop; 1153 u8 state; 1154 1155 fa = fa_first; 1156 if (fa_match) { 1157 if (fa == fa_match) 1158 err = 0; 1159 goto out; 1160 } 1161 err = -ENOBUFS; 1162 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1163 if (!new_fa) 1164 goto out; 1165 1166 fi_drop = fa->fa_info; 1167 new_fa->fa_tos = fa->fa_tos; 1168 new_fa->fa_info = fi; 1169 new_fa->fa_type = cfg->fc_type; 1170 state = fa->fa_state; 1171 new_fa->fa_state = state & ~FA_S_ACCESSED; 1172 new_fa->fa_slen = fa->fa_slen; 1173 new_fa->tb_id = tb->tb_id; 1174 1175 err = switchdev_fib_ipv4_add(key, plen, fi, 1176 new_fa->fa_tos, 1177 cfg->fc_type, 1178 cfg->fc_nlflags, 1179 tb->tb_id); 1180 if (err) { 1181 switchdev_fib_ipv4_abort(fi); 1182 kmem_cache_free(fn_alias_kmem, new_fa); 1183 goto out; 1184 } 1185 1186 hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list); 1187 1188 alias_free_mem_rcu(fa); 1189 1190 fib_release_info(fi_drop); 1191 if (state & FA_S_ACCESSED) 1192 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1193 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, 1194 tb->tb_id, &cfg->fc_nlinfo, NLM_F_REPLACE); 1195 1196 goto succeeded; 1197 } 1198 /* Error if we find a perfect match which 1199 * uses the same scope, type, and nexthop 1200 * information. 1201 */ 1202 if (fa_match) 1203 goto out; 1204 1205 if (cfg->fc_nlflags & NLM_F_APPEND) 1206 nlflags = NLM_F_APPEND; 1207 else 1208 fa = fa_first; 1209 } 1210 err = -ENOENT; 1211 if (!(cfg->fc_nlflags & NLM_F_CREATE)) 1212 goto out; 1213 1214 err = -ENOBUFS; 1215 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1216 if (!new_fa) 1217 goto out; 1218 1219 new_fa->fa_info = fi; 1220 new_fa->fa_tos = tos; 1221 new_fa->fa_type = cfg->fc_type; 1222 new_fa->fa_state = 0; 1223 new_fa->fa_slen = slen; 1224 new_fa->tb_id = tb->tb_id; 1225 1226 /* (Optionally) offload fib entry to switch hardware. */ 1227 err = switchdev_fib_ipv4_add(key, plen, fi, tos, cfg->fc_type, 1228 cfg->fc_nlflags, tb->tb_id); 1229 if (err) { 1230 switchdev_fib_ipv4_abort(fi); 1231 goto out_free_new_fa; 1232 } 1233 1234 /* Insert new entry to the list. */ 1235 err = fib_insert_alias(t, tp, l, new_fa, fa, key); 1236 if (err) 1237 goto out_sw_fib_del; 1238 1239 if (!plen) 1240 tb->tb_num_default++; 1241 1242 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1243 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id, 1244 &cfg->fc_nlinfo, nlflags); 1245 succeeded: 1246 return 0; 1247 1248 out_sw_fib_del: 1249 switchdev_fib_ipv4_del(key, plen, fi, tos, cfg->fc_type, tb->tb_id); 1250 out_free_new_fa: 1251 kmem_cache_free(fn_alias_kmem, new_fa); 1252 out: 1253 fib_release_info(fi); 1254 err: 1255 return err; 1256 } 1257 1258 static inline t_key prefix_mismatch(t_key key, struct key_vector *n) 1259 { 1260 t_key prefix = n->key; 1261 1262 return (key ^ prefix) & (prefix | -prefix); 1263 } 1264 1265 /* should be called with rcu_read_lock */ 1266 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 1267 struct fib_result *res, int fib_flags) 1268 { 1269 struct trie *t = (struct trie *) tb->tb_data; 1270 #ifdef CONFIG_IP_FIB_TRIE_STATS 1271 struct trie_use_stats __percpu *stats = t->stats; 1272 #endif 1273 const t_key key = ntohl(flp->daddr); 1274 struct key_vector *n, *pn; 1275 struct fib_alias *fa; 1276 unsigned long index; 1277 t_key cindex; 1278 1279 pn = t->kv; 1280 cindex = 0; 1281 1282 n = get_child_rcu(pn, cindex); 1283 if (!n) 1284 return -EAGAIN; 1285 1286 #ifdef CONFIG_IP_FIB_TRIE_STATS 1287 this_cpu_inc(stats->gets); 1288 #endif 1289 1290 /* Step 1: Travel to the longest prefix match in the trie */ 1291 for (;;) { 1292 index = get_cindex(key, n); 1293 1294 /* This bit of code is a bit tricky but it combines multiple 1295 * checks into a single check. The prefix consists of the 1296 * prefix plus zeros for the "bits" in the prefix. The index 1297 * is the difference between the key and this value. From 1298 * this we can actually derive several pieces of data. 1299 * if (index >= (1ul << bits)) 1300 * we have a mismatch in skip bits and failed 1301 * else 1302 * we know the value is cindex 1303 * 1304 * This check is safe even if bits == KEYLENGTH due to the 1305 * fact that we can only allocate a node with 32 bits if a 1306 * long is greater than 32 bits. 1307 */ 1308 if (index >= (1ul << n->bits)) 1309 break; 1310 1311 /* we have found a leaf. Prefixes have already been compared */ 1312 if (IS_LEAF(n)) 1313 goto found; 1314 1315 /* only record pn and cindex if we are going to be chopping 1316 * bits later. Otherwise we are just wasting cycles. 1317 */ 1318 if (n->slen > n->pos) { 1319 pn = n; 1320 cindex = index; 1321 } 1322 1323 n = get_child_rcu(n, index); 1324 if (unlikely(!n)) 1325 goto backtrace; 1326 } 1327 1328 /* Step 2: Sort out leaves and begin backtracing for longest prefix */ 1329 for (;;) { 1330 /* record the pointer where our next node pointer is stored */ 1331 struct key_vector __rcu **cptr = n->tnode; 1332 1333 /* This test verifies that none of the bits that differ 1334 * between the key and the prefix exist in the region of 1335 * the lsb and higher in the prefix. 1336 */ 1337 if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos)) 1338 goto backtrace; 1339 1340 /* exit out and process leaf */ 1341 if (unlikely(IS_LEAF(n))) 1342 break; 1343 1344 /* Don't bother recording parent info. Since we are in 1345 * prefix match mode we will have to come back to wherever 1346 * we started this traversal anyway 1347 */ 1348 1349 while ((n = rcu_dereference(*cptr)) == NULL) { 1350 backtrace: 1351 #ifdef CONFIG_IP_FIB_TRIE_STATS 1352 if (!n) 1353 this_cpu_inc(stats->null_node_hit); 1354 #endif 1355 /* If we are at cindex 0 there are no more bits for 1356 * us to strip at this level so we must ascend back 1357 * up one level to see if there are any more bits to 1358 * be stripped there. 1359 */ 1360 while (!cindex) { 1361 t_key pkey = pn->key; 1362 1363 /* If we don't have a parent then there is 1364 * nothing for us to do as we do not have any 1365 * further nodes to parse. 1366 */ 1367 if (IS_TRIE(pn)) 1368 return -EAGAIN; 1369 #ifdef CONFIG_IP_FIB_TRIE_STATS 1370 this_cpu_inc(stats->backtrack); 1371 #endif 1372 /* Get Child's index */ 1373 pn = node_parent_rcu(pn); 1374 cindex = get_index(pkey, pn); 1375 } 1376 1377 /* strip the least significant bit from the cindex */ 1378 cindex &= cindex - 1; 1379 1380 /* grab pointer for next child node */ 1381 cptr = &pn->tnode[cindex]; 1382 } 1383 } 1384 1385 found: 1386 /* this line carries forward the xor from earlier in the function */ 1387 index = key ^ n->key; 1388 1389 /* Step 3: Process the leaf, if that fails fall back to backtracing */ 1390 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) { 1391 struct fib_info *fi = fa->fa_info; 1392 int nhsel, err; 1393 1394 if ((index >= (1ul << fa->fa_slen)) && 1395 ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen != KEYLENGTH))) 1396 continue; 1397 if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos) 1398 continue; 1399 if (fi->fib_dead) 1400 continue; 1401 if (fa->fa_info->fib_scope < flp->flowi4_scope) 1402 continue; 1403 fib_alias_accessed(fa); 1404 err = fib_props[fa->fa_type].error; 1405 if (unlikely(err < 0)) { 1406 #ifdef CONFIG_IP_FIB_TRIE_STATS 1407 this_cpu_inc(stats->semantic_match_passed); 1408 #endif 1409 return err; 1410 } 1411 if (fi->fib_flags & RTNH_F_DEAD) 1412 continue; 1413 for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) { 1414 const struct fib_nh *nh = &fi->fib_nh[nhsel]; 1415 struct in_device *in_dev = __in_dev_get_rcu(nh->nh_dev); 1416 1417 if (nh->nh_flags & RTNH_F_DEAD) 1418 continue; 1419 if (in_dev && 1420 IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) && 1421 nh->nh_flags & RTNH_F_LINKDOWN && 1422 !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE)) 1423 continue; 1424 if (flp->flowi4_oif && flp->flowi4_oif != nh->nh_oif) 1425 continue; 1426 1427 if (!(fib_flags & FIB_LOOKUP_NOREF)) 1428 atomic_inc(&fi->fib_clntref); 1429 1430 res->prefixlen = KEYLENGTH - fa->fa_slen; 1431 res->nh_sel = nhsel; 1432 res->type = fa->fa_type; 1433 res->scope = fi->fib_scope; 1434 res->fi = fi; 1435 res->table = tb; 1436 res->fa_head = &n->leaf; 1437 #ifdef CONFIG_IP_FIB_TRIE_STATS 1438 this_cpu_inc(stats->semantic_match_passed); 1439 #endif 1440 return err; 1441 } 1442 } 1443 #ifdef CONFIG_IP_FIB_TRIE_STATS 1444 this_cpu_inc(stats->semantic_match_miss); 1445 #endif 1446 goto backtrace; 1447 } 1448 EXPORT_SYMBOL_GPL(fib_table_lookup); 1449 1450 static void fib_remove_alias(struct trie *t, struct key_vector *tp, 1451 struct key_vector *l, struct fib_alias *old) 1452 { 1453 /* record the location of the previous list_info entry */ 1454 struct hlist_node **pprev = old->fa_list.pprev; 1455 struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next); 1456 1457 /* remove the fib_alias from the list */ 1458 hlist_del_rcu(&old->fa_list); 1459 1460 /* if we emptied the list this leaf will be freed and we can sort 1461 * out parent suffix lengths as a part of trie_rebalance 1462 */ 1463 if (hlist_empty(&l->leaf)) { 1464 put_child_root(tp, l->key, NULL); 1465 node_free(l); 1466 trie_rebalance(t, tp); 1467 return; 1468 } 1469 1470 /* only access fa if it is pointing at the last valid hlist_node */ 1471 if (*pprev) 1472 return; 1473 1474 /* update the trie with the latest suffix length */ 1475 l->slen = fa->fa_slen; 1476 leaf_pull_suffix(tp, l); 1477 } 1478 1479 /* Caller must hold RTNL. */ 1480 int fib_table_delete(struct fib_table *tb, struct fib_config *cfg) 1481 { 1482 struct trie *t = (struct trie *) tb->tb_data; 1483 struct fib_alias *fa, *fa_to_delete; 1484 struct key_vector *l, *tp; 1485 u8 plen = cfg->fc_dst_len; 1486 u8 slen = KEYLENGTH - plen; 1487 u8 tos = cfg->fc_tos; 1488 u32 key; 1489 1490 if (plen > KEYLENGTH) 1491 return -EINVAL; 1492 1493 key = ntohl(cfg->fc_dst); 1494 1495 if ((plen < KEYLENGTH) && (key << plen)) 1496 return -EINVAL; 1497 1498 l = fib_find_node(t, &tp, key); 1499 if (!l) 1500 return -ESRCH; 1501 1502 fa = fib_find_alias(&l->leaf, slen, tos, 0, tb->tb_id); 1503 if (!fa) 1504 return -ESRCH; 1505 1506 pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t); 1507 1508 fa_to_delete = NULL; 1509 hlist_for_each_entry_from(fa, fa_list) { 1510 struct fib_info *fi = fa->fa_info; 1511 1512 if ((fa->fa_slen != slen) || 1513 (fa->tb_id != tb->tb_id) || 1514 (fa->fa_tos != tos)) 1515 break; 1516 1517 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) && 1518 (cfg->fc_scope == RT_SCOPE_NOWHERE || 1519 fa->fa_info->fib_scope == cfg->fc_scope) && 1520 (!cfg->fc_prefsrc || 1521 fi->fib_prefsrc == cfg->fc_prefsrc) && 1522 (!cfg->fc_protocol || 1523 fi->fib_protocol == cfg->fc_protocol) && 1524 fib_nh_match(cfg, fi) == 0) { 1525 fa_to_delete = fa; 1526 break; 1527 } 1528 } 1529 1530 if (!fa_to_delete) 1531 return -ESRCH; 1532 1533 switchdev_fib_ipv4_del(key, plen, fa_to_delete->fa_info, tos, 1534 cfg->fc_type, tb->tb_id); 1535 1536 rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id, 1537 &cfg->fc_nlinfo, 0); 1538 1539 if (!plen) 1540 tb->tb_num_default--; 1541 1542 fib_remove_alias(t, tp, l, fa_to_delete); 1543 1544 if (fa_to_delete->fa_state & FA_S_ACCESSED) 1545 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1546 1547 fib_release_info(fa_to_delete->fa_info); 1548 alias_free_mem_rcu(fa_to_delete); 1549 return 0; 1550 } 1551 1552 /* Scan for the next leaf starting at the provided key value */ 1553 static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key) 1554 { 1555 struct key_vector *pn, *n = *tn; 1556 unsigned long cindex; 1557 1558 /* this loop is meant to try and find the key in the trie */ 1559 do { 1560 /* record parent and next child index */ 1561 pn = n; 1562 cindex = key ? get_index(key, pn) : 0; 1563 1564 if (cindex >> pn->bits) 1565 break; 1566 1567 /* descend into the next child */ 1568 n = get_child_rcu(pn, cindex++); 1569 if (!n) 1570 break; 1571 1572 /* guarantee forward progress on the keys */ 1573 if (IS_LEAF(n) && (n->key >= key)) 1574 goto found; 1575 } while (IS_TNODE(n)); 1576 1577 /* this loop will search for the next leaf with a greater key */ 1578 while (!IS_TRIE(pn)) { 1579 /* if we exhausted the parent node we will need to climb */ 1580 if (cindex >= (1ul << pn->bits)) { 1581 t_key pkey = pn->key; 1582 1583 pn = node_parent_rcu(pn); 1584 cindex = get_index(pkey, pn) + 1; 1585 continue; 1586 } 1587 1588 /* grab the next available node */ 1589 n = get_child_rcu(pn, cindex++); 1590 if (!n) 1591 continue; 1592 1593 /* no need to compare keys since we bumped the index */ 1594 if (IS_LEAF(n)) 1595 goto found; 1596 1597 /* Rescan start scanning in new node */ 1598 pn = n; 1599 cindex = 0; 1600 } 1601 1602 *tn = pn; 1603 return NULL; /* Root of trie */ 1604 found: 1605 /* if we are at the limit for keys just return NULL for the tnode */ 1606 *tn = pn; 1607 return n; 1608 } 1609 1610 static void fib_trie_free(struct fib_table *tb) 1611 { 1612 struct trie *t = (struct trie *)tb->tb_data; 1613 struct key_vector *pn = t->kv; 1614 unsigned long cindex = 1; 1615 struct hlist_node *tmp; 1616 struct fib_alias *fa; 1617 1618 /* walk trie in reverse order and free everything */ 1619 for (;;) { 1620 struct key_vector *n; 1621 1622 if (!(cindex--)) { 1623 t_key pkey = pn->key; 1624 1625 if (IS_TRIE(pn)) 1626 break; 1627 1628 n = pn; 1629 pn = node_parent(pn); 1630 1631 /* drop emptied tnode */ 1632 put_child_root(pn, n->key, NULL); 1633 node_free(n); 1634 1635 cindex = get_index(pkey, pn); 1636 1637 continue; 1638 } 1639 1640 /* grab the next available node */ 1641 n = get_child(pn, cindex); 1642 if (!n) 1643 continue; 1644 1645 if (IS_TNODE(n)) { 1646 /* record pn and cindex for leaf walking */ 1647 pn = n; 1648 cindex = 1ul << n->bits; 1649 1650 continue; 1651 } 1652 1653 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 1654 hlist_del_rcu(&fa->fa_list); 1655 alias_free_mem_rcu(fa); 1656 } 1657 1658 put_child_root(pn, n->key, NULL); 1659 node_free(n); 1660 } 1661 1662 #ifdef CONFIG_IP_FIB_TRIE_STATS 1663 free_percpu(t->stats); 1664 #endif 1665 kfree(tb); 1666 } 1667 1668 struct fib_table *fib_trie_unmerge(struct fib_table *oldtb) 1669 { 1670 struct trie *ot = (struct trie *)oldtb->tb_data; 1671 struct key_vector *l, *tp = ot->kv; 1672 struct fib_table *local_tb; 1673 struct fib_alias *fa; 1674 struct trie *lt; 1675 t_key key = 0; 1676 1677 if (oldtb->tb_data == oldtb->__data) 1678 return oldtb; 1679 1680 local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL); 1681 if (!local_tb) 1682 return NULL; 1683 1684 lt = (struct trie *)local_tb->tb_data; 1685 1686 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 1687 struct key_vector *local_l = NULL, *local_tp; 1688 1689 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 1690 struct fib_alias *new_fa; 1691 1692 if (local_tb->tb_id != fa->tb_id) 1693 continue; 1694 1695 /* clone fa for new local table */ 1696 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1697 if (!new_fa) 1698 goto out; 1699 1700 memcpy(new_fa, fa, sizeof(*fa)); 1701 1702 /* insert clone into table */ 1703 if (!local_l) 1704 local_l = fib_find_node(lt, &local_tp, l->key); 1705 1706 if (fib_insert_alias(lt, local_tp, local_l, new_fa, 1707 NULL, l->key)) 1708 goto out; 1709 } 1710 1711 /* stop loop if key wrapped back to 0 */ 1712 key = l->key + 1; 1713 if (key < l->key) 1714 break; 1715 } 1716 1717 return local_tb; 1718 out: 1719 fib_trie_free(local_tb); 1720 1721 return NULL; 1722 } 1723 1724 /* Caller must hold RTNL */ 1725 void fib_table_flush_external(struct fib_table *tb) 1726 { 1727 struct trie *t = (struct trie *)tb->tb_data; 1728 struct key_vector *pn = t->kv; 1729 unsigned long cindex = 1; 1730 struct hlist_node *tmp; 1731 struct fib_alias *fa; 1732 1733 /* walk trie in reverse order */ 1734 for (;;) { 1735 unsigned char slen = 0; 1736 struct key_vector *n; 1737 1738 if (!(cindex--)) { 1739 t_key pkey = pn->key; 1740 1741 /* cannot resize the trie vector */ 1742 if (IS_TRIE(pn)) 1743 break; 1744 1745 /* resize completed node */ 1746 pn = resize(t, pn); 1747 cindex = get_index(pkey, pn); 1748 1749 continue; 1750 } 1751 1752 /* grab the next available node */ 1753 n = get_child(pn, cindex); 1754 if (!n) 1755 continue; 1756 1757 if (IS_TNODE(n)) { 1758 /* record pn and cindex for leaf walking */ 1759 pn = n; 1760 cindex = 1ul << n->bits; 1761 1762 continue; 1763 } 1764 1765 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 1766 struct fib_info *fi = fa->fa_info; 1767 1768 /* if alias was cloned to local then we just 1769 * need to remove the local copy from main 1770 */ 1771 if (tb->tb_id != fa->tb_id) { 1772 hlist_del_rcu(&fa->fa_list); 1773 alias_free_mem_rcu(fa); 1774 continue; 1775 } 1776 1777 /* record local slen */ 1778 slen = fa->fa_slen; 1779 1780 if (!fi || !(fi->fib_flags & RTNH_F_OFFLOAD)) 1781 continue; 1782 1783 switchdev_fib_ipv4_del(n->key, KEYLENGTH - fa->fa_slen, 1784 fi, fa->fa_tos, fa->fa_type, 1785 tb->tb_id); 1786 } 1787 1788 /* update leaf slen */ 1789 n->slen = slen; 1790 1791 if (hlist_empty(&n->leaf)) { 1792 put_child_root(pn, n->key, NULL); 1793 node_free(n); 1794 } else { 1795 leaf_pull_suffix(pn, n); 1796 } 1797 } 1798 } 1799 1800 /* Caller must hold RTNL. */ 1801 int fib_table_flush(struct fib_table *tb) 1802 { 1803 struct trie *t = (struct trie *)tb->tb_data; 1804 struct key_vector *pn = t->kv; 1805 unsigned long cindex = 1; 1806 struct hlist_node *tmp; 1807 struct fib_alias *fa; 1808 int found = 0; 1809 1810 /* walk trie in reverse order */ 1811 for (;;) { 1812 unsigned char slen = 0; 1813 struct key_vector *n; 1814 1815 if (!(cindex--)) { 1816 t_key pkey = pn->key; 1817 1818 /* cannot resize the trie vector */ 1819 if (IS_TRIE(pn)) 1820 break; 1821 1822 /* resize completed node */ 1823 pn = resize(t, pn); 1824 cindex = get_index(pkey, pn); 1825 1826 continue; 1827 } 1828 1829 /* grab the next available node */ 1830 n = get_child(pn, cindex); 1831 if (!n) 1832 continue; 1833 1834 if (IS_TNODE(n)) { 1835 /* record pn and cindex for leaf walking */ 1836 pn = n; 1837 cindex = 1ul << n->bits; 1838 1839 continue; 1840 } 1841 1842 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 1843 struct fib_info *fi = fa->fa_info; 1844 1845 if (!fi || !(fi->fib_flags & RTNH_F_DEAD)) { 1846 slen = fa->fa_slen; 1847 continue; 1848 } 1849 1850 switchdev_fib_ipv4_del(n->key, KEYLENGTH - fa->fa_slen, 1851 fi, fa->fa_tos, fa->fa_type, 1852 tb->tb_id); 1853 hlist_del_rcu(&fa->fa_list); 1854 fib_release_info(fa->fa_info); 1855 alias_free_mem_rcu(fa); 1856 found++; 1857 } 1858 1859 /* update leaf slen */ 1860 n->slen = slen; 1861 1862 if (hlist_empty(&n->leaf)) { 1863 put_child_root(pn, n->key, NULL); 1864 node_free(n); 1865 } else { 1866 leaf_pull_suffix(pn, n); 1867 } 1868 } 1869 1870 pr_debug("trie_flush found=%d\n", found); 1871 return found; 1872 } 1873 1874 static void __trie_free_rcu(struct rcu_head *head) 1875 { 1876 struct fib_table *tb = container_of(head, struct fib_table, rcu); 1877 #ifdef CONFIG_IP_FIB_TRIE_STATS 1878 struct trie *t = (struct trie *)tb->tb_data; 1879 1880 if (tb->tb_data == tb->__data) 1881 free_percpu(t->stats); 1882 #endif /* CONFIG_IP_FIB_TRIE_STATS */ 1883 kfree(tb); 1884 } 1885 1886 void fib_free_table(struct fib_table *tb) 1887 { 1888 call_rcu(&tb->rcu, __trie_free_rcu); 1889 } 1890 1891 static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb, 1892 struct sk_buff *skb, struct netlink_callback *cb) 1893 { 1894 __be32 xkey = htonl(l->key); 1895 struct fib_alias *fa; 1896 int i, s_i; 1897 1898 s_i = cb->args[4]; 1899 i = 0; 1900 1901 /* rcu_read_lock is hold by caller */ 1902 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 1903 if (i < s_i) { 1904 i++; 1905 continue; 1906 } 1907 1908 if (tb->tb_id != fa->tb_id) { 1909 i++; 1910 continue; 1911 } 1912 1913 if (fib_dump_info(skb, NETLINK_CB(cb->skb).portid, 1914 cb->nlh->nlmsg_seq, 1915 RTM_NEWROUTE, 1916 tb->tb_id, 1917 fa->fa_type, 1918 xkey, 1919 KEYLENGTH - fa->fa_slen, 1920 fa->fa_tos, 1921 fa->fa_info, NLM_F_MULTI) < 0) { 1922 cb->args[4] = i; 1923 return -1; 1924 } 1925 i++; 1926 } 1927 1928 cb->args[4] = i; 1929 return skb->len; 1930 } 1931 1932 /* rcu_read_lock needs to be hold by caller from readside */ 1933 int fib_table_dump(struct fib_table *tb, struct sk_buff *skb, 1934 struct netlink_callback *cb) 1935 { 1936 struct trie *t = (struct trie *)tb->tb_data; 1937 struct key_vector *l, *tp = t->kv; 1938 /* Dump starting at last key. 1939 * Note: 0.0.0.0/0 (ie default) is first key. 1940 */ 1941 int count = cb->args[2]; 1942 t_key key = cb->args[3]; 1943 1944 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 1945 if (fn_trie_dump_leaf(l, tb, skb, cb) < 0) { 1946 cb->args[3] = key; 1947 cb->args[2] = count; 1948 return -1; 1949 } 1950 1951 ++count; 1952 key = l->key + 1; 1953 1954 memset(&cb->args[4], 0, 1955 sizeof(cb->args) - 4*sizeof(cb->args[0])); 1956 1957 /* stop loop if key wrapped back to 0 */ 1958 if (key < l->key) 1959 break; 1960 } 1961 1962 cb->args[3] = key; 1963 cb->args[2] = count; 1964 1965 return skb->len; 1966 } 1967 1968 void __init fib_trie_init(void) 1969 { 1970 fn_alias_kmem = kmem_cache_create("ip_fib_alias", 1971 sizeof(struct fib_alias), 1972 0, SLAB_PANIC, NULL); 1973 1974 trie_leaf_kmem = kmem_cache_create("ip_fib_trie", 1975 LEAF_SIZE, 1976 0, SLAB_PANIC, NULL); 1977 } 1978 1979 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias) 1980 { 1981 struct fib_table *tb; 1982 struct trie *t; 1983 size_t sz = sizeof(*tb); 1984 1985 if (!alias) 1986 sz += sizeof(struct trie); 1987 1988 tb = kzalloc(sz, GFP_KERNEL); 1989 if (!tb) 1990 return NULL; 1991 1992 tb->tb_id = id; 1993 tb->tb_default = -1; 1994 tb->tb_num_default = 0; 1995 tb->tb_data = (alias ? alias->__data : tb->__data); 1996 1997 if (alias) 1998 return tb; 1999 2000 t = (struct trie *) tb->tb_data; 2001 t->kv[0].pos = KEYLENGTH; 2002 t->kv[0].slen = KEYLENGTH; 2003 #ifdef CONFIG_IP_FIB_TRIE_STATS 2004 t->stats = alloc_percpu(struct trie_use_stats); 2005 if (!t->stats) { 2006 kfree(tb); 2007 tb = NULL; 2008 } 2009 #endif 2010 2011 return tb; 2012 } 2013 2014 #ifdef CONFIG_PROC_FS 2015 /* Depth first Trie walk iterator */ 2016 struct fib_trie_iter { 2017 struct seq_net_private p; 2018 struct fib_table *tb; 2019 struct key_vector *tnode; 2020 unsigned int index; 2021 unsigned int depth; 2022 }; 2023 2024 static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter) 2025 { 2026 unsigned long cindex = iter->index; 2027 struct key_vector *pn = iter->tnode; 2028 t_key pkey; 2029 2030 pr_debug("get_next iter={node=%p index=%d depth=%d}\n", 2031 iter->tnode, iter->index, iter->depth); 2032 2033 while (!IS_TRIE(pn)) { 2034 while (cindex < child_length(pn)) { 2035 struct key_vector *n = get_child_rcu(pn, cindex++); 2036 2037 if (!n) 2038 continue; 2039 2040 if (IS_LEAF(n)) { 2041 iter->tnode = pn; 2042 iter->index = cindex; 2043 } else { 2044 /* push down one level */ 2045 iter->tnode = n; 2046 iter->index = 0; 2047 ++iter->depth; 2048 } 2049 2050 return n; 2051 } 2052 2053 /* Current node exhausted, pop back up */ 2054 pkey = pn->key; 2055 pn = node_parent_rcu(pn); 2056 cindex = get_index(pkey, pn) + 1; 2057 --iter->depth; 2058 } 2059 2060 /* record root node so further searches know we are done */ 2061 iter->tnode = pn; 2062 iter->index = 0; 2063 2064 return NULL; 2065 } 2066 2067 static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter, 2068 struct trie *t) 2069 { 2070 struct key_vector *n, *pn; 2071 2072 if (!t) 2073 return NULL; 2074 2075 pn = t->kv; 2076 n = rcu_dereference(pn->tnode[0]); 2077 if (!n) 2078 return NULL; 2079 2080 if (IS_TNODE(n)) { 2081 iter->tnode = n; 2082 iter->index = 0; 2083 iter->depth = 1; 2084 } else { 2085 iter->tnode = pn; 2086 iter->index = 0; 2087 iter->depth = 0; 2088 } 2089 2090 return n; 2091 } 2092 2093 static void trie_collect_stats(struct trie *t, struct trie_stat *s) 2094 { 2095 struct key_vector *n; 2096 struct fib_trie_iter iter; 2097 2098 memset(s, 0, sizeof(*s)); 2099 2100 rcu_read_lock(); 2101 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) { 2102 if (IS_LEAF(n)) { 2103 struct fib_alias *fa; 2104 2105 s->leaves++; 2106 s->totdepth += iter.depth; 2107 if (iter.depth > s->maxdepth) 2108 s->maxdepth = iter.depth; 2109 2110 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) 2111 ++s->prefixes; 2112 } else { 2113 s->tnodes++; 2114 if (n->bits < MAX_STAT_DEPTH) 2115 s->nodesizes[n->bits]++; 2116 s->nullpointers += tn_info(n)->empty_children; 2117 } 2118 } 2119 rcu_read_unlock(); 2120 } 2121 2122 /* 2123 * This outputs /proc/net/fib_triestats 2124 */ 2125 static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat) 2126 { 2127 unsigned int i, max, pointers, bytes, avdepth; 2128 2129 if (stat->leaves) 2130 avdepth = stat->totdepth*100 / stat->leaves; 2131 else 2132 avdepth = 0; 2133 2134 seq_printf(seq, "\tAver depth: %u.%02d\n", 2135 avdepth / 100, avdepth % 100); 2136 seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth); 2137 2138 seq_printf(seq, "\tLeaves: %u\n", stat->leaves); 2139 bytes = LEAF_SIZE * stat->leaves; 2140 2141 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes); 2142 bytes += sizeof(struct fib_alias) * stat->prefixes; 2143 2144 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes); 2145 bytes += TNODE_SIZE(0) * stat->tnodes; 2146 2147 max = MAX_STAT_DEPTH; 2148 while (max > 0 && stat->nodesizes[max-1] == 0) 2149 max--; 2150 2151 pointers = 0; 2152 for (i = 1; i < max; i++) 2153 if (stat->nodesizes[i] != 0) { 2154 seq_printf(seq, " %u: %u", i, stat->nodesizes[i]); 2155 pointers += (1<<i) * stat->nodesizes[i]; 2156 } 2157 seq_putc(seq, '\n'); 2158 seq_printf(seq, "\tPointers: %u\n", pointers); 2159 2160 bytes += sizeof(struct key_vector *) * pointers; 2161 seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers); 2162 seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024); 2163 } 2164 2165 #ifdef CONFIG_IP_FIB_TRIE_STATS 2166 static void trie_show_usage(struct seq_file *seq, 2167 const struct trie_use_stats __percpu *stats) 2168 { 2169 struct trie_use_stats s = { 0 }; 2170 int cpu; 2171 2172 /* loop through all of the CPUs and gather up the stats */ 2173 for_each_possible_cpu(cpu) { 2174 const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu); 2175 2176 s.gets += pcpu->gets; 2177 s.backtrack += pcpu->backtrack; 2178 s.semantic_match_passed += pcpu->semantic_match_passed; 2179 s.semantic_match_miss += pcpu->semantic_match_miss; 2180 s.null_node_hit += pcpu->null_node_hit; 2181 s.resize_node_skipped += pcpu->resize_node_skipped; 2182 } 2183 2184 seq_printf(seq, "\nCounters:\n---------\n"); 2185 seq_printf(seq, "gets = %u\n", s.gets); 2186 seq_printf(seq, "backtracks = %u\n", s.backtrack); 2187 seq_printf(seq, "semantic match passed = %u\n", 2188 s.semantic_match_passed); 2189 seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss); 2190 seq_printf(seq, "null node hit= %u\n", s.null_node_hit); 2191 seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped); 2192 } 2193 #endif /* CONFIG_IP_FIB_TRIE_STATS */ 2194 2195 static void fib_table_print(struct seq_file *seq, struct fib_table *tb) 2196 { 2197 if (tb->tb_id == RT_TABLE_LOCAL) 2198 seq_puts(seq, "Local:\n"); 2199 else if (tb->tb_id == RT_TABLE_MAIN) 2200 seq_puts(seq, "Main:\n"); 2201 else 2202 seq_printf(seq, "Id %d:\n", tb->tb_id); 2203 } 2204 2205 2206 static int fib_triestat_seq_show(struct seq_file *seq, void *v) 2207 { 2208 struct net *net = (struct net *)seq->private; 2209 unsigned int h; 2210 2211 seq_printf(seq, 2212 "Basic info: size of leaf:" 2213 " %Zd bytes, size of tnode: %Zd bytes.\n", 2214 LEAF_SIZE, TNODE_SIZE(0)); 2215 2216 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2217 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2218 struct fib_table *tb; 2219 2220 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2221 struct trie *t = (struct trie *) tb->tb_data; 2222 struct trie_stat stat; 2223 2224 if (!t) 2225 continue; 2226 2227 fib_table_print(seq, tb); 2228 2229 trie_collect_stats(t, &stat); 2230 trie_show_stats(seq, &stat); 2231 #ifdef CONFIG_IP_FIB_TRIE_STATS 2232 trie_show_usage(seq, t->stats); 2233 #endif 2234 } 2235 } 2236 2237 return 0; 2238 } 2239 2240 static int fib_triestat_seq_open(struct inode *inode, struct file *file) 2241 { 2242 return single_open_net(inode, file, fib_triestat_seq_show); 2243 } 2244 2245 static const struct file_operations fib_triestat_fops = { 2246 .owner = THIS_MODULE, 2247 .open = fib_triestat_seq_open, 2248 .read = seq_read, 2249 .llseek = seq_lseek, 2250 .release = single_release_net, 2251 }; 2252 2253 static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos) 2254 { 2255 struct fib_trie_iter *iter = seq->private; 2256 struct net *net = seq_file_net(seq); 2257 loff_t idx = 0; 2258 unsigned int h; 2259 2260 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2261 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2262 struct fib_table *tb; 2263 2264 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2265 struct key_vector *n; 2266 2267 for (n = fib_trie_get_first(iter, 2268 (struct trie *) tb->tb_data); 2269 n; n = fib_trie_get_next(iter)) 2270 if (pos == idx++) { 2271 iter->tb = tb; 2272 return n; 2273 } 2274 } 2275 } 2276 2277 return NULL; 2278 } 2279 2280 static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos) 2281 __acquires(RCU) 2282 { 2283 rcu_read_lock(); 2284 return fib_trie_get_idx(seq, *pos); 2285 } 2286 2287 static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2288 { 2289 struct fib_trie_iter *iter = seq->private; 2290 struct net *net = seq_file_net(seq); 2291 struct fib_table *tb = iter->tb; 2292 struct hlist_node *tb_node; 2293 unsigned int h; 2294 struct key_vector *n; 2295 2296 ++*pos; 2297 /* next node in same table */ 2298 n = fib_trie_get_next(iter); 2299 if (n) 2300 return n; 2301 2302 /* walk rest of this hash chain */ 2303 h = tb->tb_id & (FIB_TABLE_HASHSZ - 1); 2304 while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) { 2305 tb = hlist_entry(tb_node, struct fib_table, tb_hlist); 2306 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data); 2307 if (n) 2308 goto found; 2309 } 2310 2311 /* new hash chain */ 2312 while (++h < FIB_TABLE_HASHSZ) { 2313 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2314 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2315 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data); 2316 if (n) 2317 goto found; 2318 } 2319 } 2320 return NULL; 2321 2322 found: 2323 iter->tb = tb; 2324 return n; 2325 } 2326 2327 static void fib_trie_seq_stop(struct seq_file *seq, void *v) 2328 __releases(RCU) 2329 { 2330 rcu_read_unlock(); 2331 } 2332 2333 static void seq_indent(struct seq_file *seq, int n) 2334 { 2335 while (n-- > 0) 2336 seq_puts(seq, " "); 2337 } 2338 2339 static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s) 2340 { 2341 switch (s) { 2342 case RT_SCOPE_UNIVERSE: return "universe"; 2343 case RT_SCOPE_SITE: return "site"; 2344 case RT_SCOPE_LINK: return "link"; 2345 case RT_SCOPE_HOST: return "host"; 2346 case RT_SCOPE_NOWHERE: return "nowhere"; 2347 default: 2348 snprintf(buf, len, "scope=%d", s); 2349 return buf; 2350 } 2351 } 2352 2353 static const char *const rtn_type_names[__RTN_MAX] = { 2354 [RTN_UNSPEC] = "UNSPEC", 2355 [RTN_UNICAST] = "UNICAST", 2356 [RTN_LOCAL] = "LOCAL", 2357 [RTN_BROADCAST] = "BROADCAST", 2358 [RTN_ANYCAST] = "ANYCAST", 2359 [RTN_MULTICAST] = "MULTICAST", 2360 [RTN_BLACKHOLE] = "BLACKHOLE", 2361 [RTN_UNREACHABLE] = "UNREACHABLE", 2362 [RTN_PROHIBIT] = "PROHIBIT", 2363 [RTN_THROW] = "THROW", 2364 [RTN_NAT] = "NAT", 2365 [RTN_XRESOLVE] = "XRESOLVE", 2366 }; 2367 2368 static inline const char *rtn_type(char *buf, size_t len, unsigned int t) 2369 { 2370 if (t < __RTN_MAX && rtn_type_names[t]) 2371 return rtn_type_names[t]; 2372 snprintf(buf, len, "type %u", t); 2373 return buf; 2374 } 2375 2376 /* Pretty print the trie */ 2377 static int fib_trie_seq_show(struct seq_file *seq, void *v) 2378 { 2379 const struct fib_trie_iter *iter = seq->private; 2380 struct key_vector *n = v; 2381 2382 if (IS_TRIE(node_parent_rcu(n))) 2383 fib_table_print(seq, iter->tb); 2384 2385 if (IS_TNODE(n)) { 2386 __be32 prf = htonl(n->key); 2387 2388 seq_indent(seq, iter->depth-1); 2389 seq_printf(seq, " +-- %pI4/%zu %u %u %u\n", 2390 &prf, KEYLENGTH - n->pos - n->bits, n->bits, 2391 tn_info(n)->full_children, 2392 tn_info(n)->empty_children); 2393 } else { 2394 __be32 val = htonl(n->key); 2395 struct fib_alias *fa; 2396 2397 seq_indent(seq, iter->depth); 2398 seq_printf(seq, " |-- %pI4\n", &val); 2399 2400 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) { 2401 char buf1[32], buf2[32]; 2402 2403 seq_indent(seq, iter->depth + 1); 2404 seq_printf(seq, " /%zu %s %s", 2405 KEYLENGTH - fa->fa_slen, 2406 rtn_scope(buf1, sizeof(buf1), 2407 fa->fa_info->fib_scope), 2408 rtn_type(buf2, sizeof(buf2), 2409 fa->fa_type)); 2410 if (fa->fa_tos) 2411 seq_printf(seq, " tos=%d", fa->fa_tos); 2412 seq_putc(seq, '\n'); 2413 } 2414 } 2415 2416 return 0; 2417 } 2418 2419 static const struct seq_operations fib_trie_seq_ops = { 2420 .start = fib_trie_seq_start, 2421 .next = fib_trie_seq_next, 2422 .stop = fib_trie_seq_stop, 2423 .show = fib_trie_seq_show, 2424 }; 2425 2426 static int fib_trie_seq_open(struct inode *inode, struct file *file) 2427 { 2428 return seq_open_net(inode, file, &fib_trie_seq_ops, 2429 sizeof(struct fib_trie_iter)); 2430 } 2431 2432 static const struct file_operations fib_trie_fops = { 2433 .owner = THIS_MODULE, 2434 .open = fib_trie_seq_open, 2435 .read = seq_read, 2436 .llseek = seq_lseek, 2437 .release = seq_release_net, 2438 }; 2439 2440 struct fib_route_iter { 2441 struct seq_net_private p; 2442 struct fib_table *main_tb; 2443 struct key_vector *tnode; 2444 loff_t pos; 2445 t_key key; 2446 }; 2447 2448 static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter, 2449 loff_t pos) 2450 { 2451 struct fib_table *tb = iter->main_tb; 2452 struct key_vector *l, **tp = &iter->tnode; 2453 struct trie *t; 2454 t_key key; 2455 2456 /* use cache location of next-to-find key */ 2457 if (iter->pos > 0 && pos >= iter->pos) { 2458 pos -= iter->pos; 2459 key = iter->key; 2460 } else { 2461 t = (struct trie *)tb->tb_data; 2462 iter->tnode = t->kv; 2463 iter->pos = 0; 2464 key = 0; 2465 } 2466 2467 while ((l = leaf_walk_rcu(tp, key)) != NULL) { 2468 key = l->key + 1; 2469 iter->pos++; 2470 2471 if (pos-- <= 0) 2472 break; 2473 2474 l = NULL; 2475 2476 /* handle unlikely case of a key wrap */ 2477 if (!key) 2478 break; 2479 } 2480 2481 if (l) 2482 iter->key = key; /* remember it */ 2483 else 2484 iter->pos = 0; /* forget it */ 2485 2486 return l; 2487 } 2488 2489 static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos) 2490 __acquires(RCU) 2491 { 2492 struct fib_route_iter *iter = seq->private; 2493 struct fib_table *tb; 2494 struct trie *t; 2495 2496 rcu_read_lock(); 2497 2498 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN); 2499 if (!tb) 2500 return NULL; 2501 2502 iter->main_tb = tb; 2503 2504 if (*pos != 0) 2505 return fib_route_get_idx(iter, *pos); 2506 2507 t = (struct trie *)tb->tb_data; 2508 iter->tnode = t->kv; 2509 iter->pos = 0; 2510 iter->key = 0; 2511 2512 return SEQ_START_TOKEN; 2513 } 2514 2515 static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2516 { 2517 struct fib_route_iter *iter = seq->private; 2518 struct key_vector *l = NULL; 2519 t_key key = iter->key; 2520 2521 ++*pos; 2522 2523 /* only allow key of 0 for start of sequence */ 2524 if ((v == SEQ_START_TOKEN) || key) 2525 l = leaf_walk_rcu(&iter->tnode, key); 2526 2527 if (l) { 2528 iter->key = l->key + 1; 2529 iter->pos++; 2530 } else { 2531 iter->pos = 0; 2532 } 2533 2534 return l; 2535 } 2536 2537 static void fib_route_seq_stop(struct seq_file *seq, void *v) 2538 __releases(RCU) 2539 { 2540 rcu_read_unlock(); 2541 } 2542 2543 static unsigned int fib_flag_trans(int type, __be32 mask, const struct fib_info *fi) 2544 { 2545 unsigned int flags = 0; 2546 2547 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT) 2548 flags = RTF_REJECT; 2549 if (fi && fi->fib_nh->nh_gw) 2550 flags |= RTF_GATEWAY; 2551 if (mask == htonl(0xFFFFFFFF)) 2552 flags |= RTF_HOST; 2553 flags |= RTF_UP; 2554 return flags; 2555 } 2556 2557 /* 2558 * This outputs /proc/net/route. 2559 * The format of the file is not supposed to be changed 2560 * and needs to be same as fib_hash output to avoid breaking 2561 * legacy utilities 2562 */ 2563 static int fib_route_seq_show(struct seq_file *seq, void *v) 2564 { 2565 struct fib_route_iter *iter = seq->private; 2566 struct fib_table *tb = iter->main_tb; 2567 struct fib_alias *fa; 2568 struct key_vector *l = v; 2569 __be32 prefix; 2570 2571 if (v == SEQ_START_TOKEN) { 2572 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway " 2573 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU" 2574 "\tWindow\tIRTT"); 2575 return 0; 2576 } 2577 2578 prefix = htonl(l->key); 2579 2580 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 2581 const struct fib_info *fi = fa->fa_info; 2582 __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen); 2583 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi); 2584 2585 if ((fa->fa_type == RTN_BROADCAST) || 2586 (fa->fa_type == RTN_MULTICAST)) 2587 continue; 2588 2589 if (fa->tb_id != tb->tb_id) 2590 continue; 2591 2592 seq_setwidth(seq, 127); 2593 2594 if (fi) 2595 seq_printf(seq, 2596 "%s\t%08X\t%08X\t%04X\t%d\t%u\t" 2597 "%d\t%08X\t%d\t%u\t%u", 2598 fi->fib_dev ? fi->fib_dev->name : "*", 2599 prefix, 2600 fi->fib_nh->nh_gw, flags, 0, 0, 2601 fi->fib_priority, 2602 mask, 2603 (fi->fib_advmss ? 2604 fi->fib_advmss + 40 : 0), 2605 fi->fib_window, 2606 fi->fib_rtt >> 3); 2607 else 2608 seq_printf(seq, 2609 "*\t%08X\t%08X\t%04X\t%d\t%u\t" 2610 "%d\t%08X\t%d\t%u\t%u", 2611 prefix, 0, flags, 0, 0, 0, 2612 mask, 0, 0, 0); 2613 2614 seq_pad(seq, '\n'); 2615 } 2616 2617 return 0; 2618 } 2619 2620 static const struct seq_operations fib_route_seq_ops = { 2621 .start = fib_route_seq_start, 2622 .next = fib_route_seq_next, 2623 .stop = fib_route_seq_stop, 2624 .show = fib_route_seq_show, 2625 }; 2626 2627 static int fib_route_seq_open(struct inode *inode, struct file *file) 2628 { 2629 return seq_open_net(inode, file, &fib_route_seq_ops, 2630 sizeof(struct fib_route_iter)); 2631 } 2632 2633 static const struct file_operations fib_route_fops = { 2634 .owner = THIS_MODULE, 2635 .open = fib_route_seq_open, 2636 .read = seq_read, 2637 .llseek = seq_lseek, 2638 .release = seq_release_net, 2639 }; 2640 2641 int __net_init fib_proc_init(struct net *net) 2642 { 2643 if (!proc_create("fib_trie", S_IRUGO, net->proc_net, &fib_trie_fops)) 2644 goto out1; 2645 2646 if (!proc_create("fib_triestat", S_IRUGO, net->proc_net, 2647 &fib_triestat_fops)) 2648 goto out2; 2649 2650 if (!proc_create("route", S_IRUGO, net->proc_net, &fib_route_fops)) 2651 goto out3; 2652 2653 return 0; 2654 2655 out3: 2656 remove_proc_entry("fib_triestat", net->proc_net); 2657 out2: 2658 remove_proc_entry("fib_trie", net->proc_net); 2659 out1: 2660 return -ENOMEM; 2661 } 2662 2663 void __net_exit fib_proc_exit(struct net *net) 2664 { 2665 remove_proc_entry("fib_trie", net->proc_net); 2666 remove_proc_entry("fib_triestat", net->proc_net); 2667 remove_proc_entry("route", net->proc_net); 2668 } 2669 2670 #endif /* CONFIG_PROC_FS */ 2671