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/inet_dscp.h> 65 #include <net/ip.h> 66 #include <net/protocol.h> 67 #include <net/route.h> 68 #include <net/tcp.h> 69 #include <net/sock.h> 70 #include <net/ip_fib.h> 71 #include <net/fib_notifier.h> 72 #include <trace/events/fib.h> 73 #include "fib_lookup.h" 74 75 static int call_fib_entry_notifier(struct notifier_block *nb, 76 enum fib_event_type event_type, u32 dst, 77 int dst_len, struct fib_alias *fa, 78 struct netlink_ext_ack *extack) 79 { 80 struct fib_entry_notifier_info info = { 81 .info.extack = extack, 82 .dst = dst, 83 .dst_len = dst_len, 84 .fi = fa->fa_info, 85 .dscp = fa->fa_dscp, 86 .type = fa->fa_type, 87 .tb_id = fa->tb_id, 88 }; 89 return call_fib4_notifier(nb, event_type, &info.info); 90 } 91 92 static int call_fib_entry_notifiers(struct net *net, 93 enum fib_event_type event_type, u32 dst, 94 int dst_len, struct fib_alias *fa, 95 struct netlink_ext_ack *extack) 96 { 97 struct fib_entry_notifier_info info = { 98 .info.extack = extack, 99 .dst = dst, 100 .dst_len = dst_len, 101 .fi = fa->fa_info, 102 .dscp = fa->fa_dscp, 103 .type = fa->fa_type, 104 .tb_id = fa->tb_id, 105 }; 106 return call_fib4_notifiers(net, event_type, &info.info); 107 } 108 109 #define MAX_STAT_DEPTH 32 110 111 #define KEYLENGTH (8*sizeof(t_key)) 112 #define KEY_MAX ((t_key)~0) 113 114 typedef unsigned int t_key; 115 116 #define IS_TRIE(n) ((n)->pos >= KEYLENGTH) 117 #define IS_TNODE(n) ((n)->bits) 118 #define IS_LEAF(n) (!(n)->bits) 119 120 struct key_vector { 121 t_key key; 122 unsigned char pos; /* 2log(KEYLENGTH) bits needed */ 123 unsigned char bits; /* 2log(KEYLENGTH) bits needed */ 124 unsigned char slen; 125 union { 126 /* This list pointer if valid if (pos | bits) == 0 (LEAF) */ 127 struct hlist_head leaf; 128 /* This array is valid if (pos | bits) > 0 (TNODE) */ 129 DECLARE_FLEX_ARRAY(struct key_vector __rcu *, tnode); 130 }; 131 }; 132 133 struct tnode { 134 struct rcu_head rcu; 135 t_key empty_children; /* KEYLENGTH bits needed */ 136 t_key full_children; /* KEYLENGTH bits needed */ 137 struct key_vector __rcu *parent; 138 struct key_vector kv[1]; 139 #define tn_bits kv[0].bits 140 }; 141 142 #define TNODE_SIZE(n) offsetof(struct tnode, kv[0].tnode[n]) 143 #define LEAF_SIZE TNODE_SIZE(1) 144 145 #ifdef CONFIG_IP_FIB_TRIE_STATS 146 struct trie_use_stats { 147 unsigned int gets; 148 unsigned int backtrack; 149 unsigned int semantic_match_passed; 150 unsigned int semantic_match_miss; 151 unsigned int null_node_hit; 152 unsigned int resize_node_skipped; 153 }; 154 #endif 155 156 struct trie_stat { 157 unsigned int totdepth; 158 unsigned int maxdepth; 159 unsigned int tnodes; 160 unsigned int leaves; 161 unsigned int nullpointers; 162 unsigned int prefixes; 163 unsigned int nodesizes[MAX_STAT_DEPTH]; 164 }; 165 166 struct trie { 167 struct key_vector kv[1]; 168 #ifdef CONFIG_IP_FIB_TRIE_STATS 169 struct trie_use_stats __percpu *stats; 170 #endif 171 }; 172 173 static struct key_vector *resize(struct trie *t, struct key_vector *tn); 174 static unsigned int tnode_free_size; 175 176 /* 177 * synchronize_rcu after call_rcu for outstanding dirty memory; it should be 178 * especially useful before resizing the root node with PREEMPT_NONE configs; 179 * the value was obtained experimentally, aiming to avoid visible slowdown. 180 */ 181 unsigned int sysctl_fib_sync_mem = 512 * 1024; 182 unsigned int sysctl_fib_sync_mem_min = 64 * 1024; 183 unsigned int sysctl_fib_sync_mem_max = 64 * 1024 * 1024; 184 185 static struct kmem_cache *fn_alias_kmem __ro_after_init; 186 static struct kmem_cache *trie_leaf_kmem __ro_after_init; 187 188 static inline struct tnode *tn_info(struct key_vector *kv) 189 { 190 return container_of(kv, struct tnode, kv[0]); 191 } 192 193 /* caller must hold RTNL */ 194 #define node_parent(tn) rtnl_dereference(tn_info(tn)->parent) 195 #define get_child(tn, i) rtnl_dereference((tn)->tnode[i]) 196 197 /* caller must hold RCU read lock or RTNL */ 198 #define node_parent_rcu(tn) rcu_dereference_rtnl(tn_info(tn)->parent) 199 #define get_child_rcu(tn, i) rcu_dereference_rtnl((tn)->tnode[i]) 200 201 /* wrapper for rcu_assign_pointer */ 202 static inline void node_set_parent(struct key_vector *n, struct key_vector *tp) 203 { 204 if (n) 205 rcu_assign_pointer(tn_info(n)->parent, tp); 206 } 207 208 #define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER(tn_info(n)->parent, p) 209 210 /* This provides us with the number of children in this node, in the case of a 211 * leaf this will return 0 meaning none of the children are accessible. 212 */ 213 static inline unsigned long child_length(const struct key_vector *tn) 214 { 215 return (1ul << tn->bits) & ~(1ul); 216 } 217 218 #define get_cindex(key, kv) (((key) ^ (kv)->key) >> (kv)->pos) 219 220 static inline unsigned long get_index(t_key key, struct key_vector *kv) 221 { 222 unsigned long index = key ^ kv->key; 223 224 if ((BITS_PER_LONG <= KEYLENGTH) && (KEYLENGTH == kv->pos)) 225 return 0; 226 227 return index >> kv->pos; 228 } 229 230 /* To understand this stuff, an understanding of keys and all their bits is 231 * necessary. Every node in the trie has a key associated with it, but not 232 * all of the bits in that key are significant. 233 * 234 * Consider a node 'n' and its parent 'tp'. 235 * 236 * If n is a leaf, every bit in its key is significant. Its presence is 237 * necessitated by path compression, since during a tree traversal (when 238 * searching for a leaf - unless we are doing an insertion) we will completely 239 * ignore all skipped bits we encounter. Thus we need to verify, at the end of 240 * a potentially successful search, that we have indeed been walking the 241 * correct key path. 242 * 243 * Note that we can never "miss" the correct key in the tree if present by 244 * following the wrong path. Path compression ensures that segments of the key 245 * that are the same for all keys with a given prefix are skipped, but the 246 * skipped part *is* identical for each node in the subtrie below the skipped 247 * bit! trie_insert() in this implementation takes care of that. 248 * 249 * if n is an internal node - a 'tnode' here, the various parts of its key 250 * have many different meanings. 251 * 252 * Example: 253 * _________________________________________________________________ 254 * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C | 255 * ----------------------------------------------------------------- 256 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 257 * 258 * _________________________________________________________________ 259 * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u | 260 * ----------------------------------------------------------------- 261 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 262 * 263 * tp->pos = 22 264 * tp->bits = 3 265 * n->pos = 13 266 * n->bits = 4 267 * 268 * First, let's just ignore the bits that come before the parent tp, that is 269 * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this 270 * point we do not use them for anything. 271 * 272 * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the 273 * index into the parent's child array. That is, they will be used to find 274 * 'n' among tp's children. 275 * 276 * The bits from (n->pos + n->bits) to (tp->pos - 1) - "S" - are skipped bits 277 * for the node n. 278 * 279 * All the bits we have seen so far are significant to the node n. The rest 280 * of the bits are really not needed or indeed known in n->key. 281 * 282 * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into 283 * n's child array, and will of course be different for each child. 284 * 285 * The rest of the bits, from 0 to (n->pos -1) - "u" - are completely unknown 286 * at this point. 287 */ 288 289 static const int halve_threshold = 25; 290 static const int inflate_threshold = 50; 291 static const int halve_threshold_root = 15; 292 static const int inflate_threshold_root = 30; 293 294 static void __alias_free_mem(struct rcu_head *head) 295 { 296 struct fib_alias *fa = container_of(head, struct fib_alias, rcu); 297 kmem_cache_free(fn_alias_kmem, fa); 298 } 299 300 static inline void alias_free_mem_rcu(struct fib_alias *fa) 301 { 302 call_rcu(&fa->rcu, __alias_free_mem); 303 } 304 305 #define TNODE_VMALLOC_MAX \ 306 ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *)) 307 308 static void __node_free_rcu(struct rcu_head *head) 309 { 310 struct tnode *n = container_of(head, struct tnode, rcu); 311 312 if (!n->tn_bits) 313 kmem_cache_free(trie_leaf_kmem, n); 314 else 315 kvfree(n); 316 } 317 318 #define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu) 319 320 static struct tnode *tnode_alloc(int bits) 321 { 322 size_t size; 323 324 /* verify bits is within bounds */ 325 if (bits > TNODE_VMALLOC_MAX) 326 return NULL; 327 328 /* determine size and verify it is non-zero and didn't overflow */ 329 size = TNODE_SIZE(1ul << bits); 330 331 if (size <= PAGE_SIZE) 332 return kzalloc(size, GFP_KERNEL); 333 else 334 return vzalloc(size); 335 } 336 337 static inline void empty_child_inc(struct key_vector *n) 338 { 339 tn_info(n)->empty_children++; 340 341 if (!tn_info(n)->empty_children) 342 tn_info(n)->full_children++; 343 } 344 345 static inline void empty_child_dec(struct key_vector *n) 346 { 347 if (!tn_info(n)->empty_children) 348 tn_info(n)->full_children--; 349 350 tn_info(n)->empty_children--; 351 } 352 353 static struct key_vector *leaf_new(t_key key, struct fib_alias *fa) 354 { 355 struct key_vector *l; 356 struct tnode *kv; 357 358 kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL); 359 if (!kv) 360 return NULL; 361 362 /* initialize key vector */ 363 l = kv->kv; 364 l->key = key; 365 l->pos = 0; 366 l->bits = 0; 367 l->slen = fa->fa_slen; 368 369 /* link leaf to fib alias */ 370 INIT_HLIST_HEAD(&l->leaf); 371 hlist_add_head(&fa->fa_list, &l->leaf); 372 373 return l; 374 } 375 376 static struct key_vector *tnode_new(t_key key, int pos, int bits) 377 { 378 unsigned int shift = pos + bits; 379 struct key_vector *tn; 380 struct tnode *tnode; 381 382 /* verify bits and pos their msb bits clear and values are valid */ 383 BUG_ON(!bits || (shift > KEYLENGTH)); 384 385 tnode = tnode_alloc(bits); 386 if (!tnode) 387 return NULL; 388 389 pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0), 390 sizeof(struct key_vector *) << bits); 391 392 if (bits == KEYLENGTH) 393 tnode->full_children = 1; 394 else 395 tnode->empty_children = 1ul << bits; 396 397 tn = tnode->kv; 398 tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0; 399 tn->pos = pos; 400 tn->bits = bits; 401 tn->slen = pos; 402 403 return tn; 404 } 405 406 /* Check whether a tnode 'n' is "full", i.e. it is an internal node 407 * and no bits are skipped. See discussion in dyntree paper p. 6 408 */ 409 static inline int tnode_full(struct key_vector *tn, struct key_vector *n) 410 { 411 return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n); 412 } 413 414 /* Add a child at position i overwriting the old value. 415 * Update the value of full_children and empty_children. 416 */ 417 static void put_child(struct key_vector *tn, unsigned long i, 418 struct key_vector *n) 419 { 420 struct key_vector *chi = get_child(tn, i); 421 int isfull, wasfull; 422 423 BUG_ON(i >= child_length(tn)); 424 425 /* update emptyChildren, overflow into fullChildren */ 426 if (!n && chi) 427 empty_child_inc(tn); 428 if (n && !chi) 429 empty_child_dec(tn); 430 431 /* update fullChildren */ 432 wasfull = tnode_full(tn, chi); 433 isfull = tnode_full(tn, n); 434 435 if (wasfull && !isfull) 436 tn_info(tn)->full_children--; 437 else if (!wasfull && isfull) 438 tn_info(tn)->full_children++; 439 440 if (n && (tn->slen < n->slen)) 441 tn->slen = n->slen; 442 443 rcu_assign_pointer(tn->tnode[i], n); 444 } 445 446 static void update_children(struct key_vector *tn) 447 { 448 unsigned long i; 449 450 /* update all of the child parent pointers */ 451 for (i = child_length(tn); i;) { 452 struct key_vector *inode = get_child(tn, --i); 453 454 if (!inode) 455 continue; 456 457 /* Either update the children of a tnode that 458 * already belongs to us or update the child 459 * to point to ourselves. 460 */ 461 if (node_parent(inode) == tn) 462 update_children(inode); 463 else 464 node_set_parent(inode, tn); 465 } 466 } 467 468 static inline void put_child_root(struct key_vector *tp, t_key key, 469 struct key_vector *n) 470 { 471 if (IS_TRIE(tp)) 472 rcu_assign_pointer(tp->tnode[0], n); 473 else 474 put_child(tp, get_index(key, tp), n); 475 } 476 477 static inline void tnode_free_init(struct key_vector *tn) 478 { 479 tn_info(tn)->rcu.next = NULL; 480 } 481 482 static inline void tnode_free_append(struct key_vector *tn, 483 struct key_vector *n) 484 { 485 tn_info(n)->rcu.next = tn_info(tn)->rcu.next; 486 tn_info(tn)->rcu.next = &tn_info(n)->rcu; 487 } 488 489 static void tnode_free(struct key_vector *tn) 490 { 491 struct callback_head *head = &tn_info(tn)->rcu; 492 493 while (head) { 494 head = head->next; 495 tnode_free_size += TNODE_SIZE(1ul << tn->bits); 496 node_free(tn); 497 498 tn = container_of(head, struct tnode, rcu)->kv; 499 } 500 501 if (tnode_free_size >= READ_ONCE(sysctl_fib_sync_mem)) { 502 tnode_free_size = 0; 503 synchronize_rcu(); 504 } 505 } 506 507 static struct key_vector *replace(struct trie *t, 508 struct key_vector *oldtnode, 509 struct key_vector *tn) 510 { 511 struct key_vector *tp = node_parent(oldtnode); 512 unsigned long i; 513 514 /* setup the parent pointer out of and back into this node */ 515 NODE_INIT_PARENT(tn, tp); 516 put_child_root(tp, tn->key, tn); 517 518 /* update all of the child parent pointers */ 519 update_children(tn); 520 521 /* all pointers should be clean so we are done */ 522 tnode_free(oldtnode); 523 524 /* resize children now that oldtnode is freed */ 525 for (i = child_length(tn); i;) { 526 struct key_vector *inode = get_child(tn, --i); 527 528 /* resize child node */ 529 if (tnode_full(tn, inode)) 530 tn = resize(t, inode); 531 } 532 533 return tp; 534 } 535 536 static struct key_vector *inflate(struct trie *t, 537 struct key_vector *oldtnode) 538 { 539 struct key_vector *tn; 540 unsigned long i; 541 t_key m; 542 543 pr_debug("In inflate\n"); 544 545 tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1); 546 if (!tn) 547 goto notnode; 548 549 /* prepare oldtnode to be freed */ 550 tnode_free_init(oldtnode); 551 552 /* Assemble all of the pointers in our cluster, in this case that 553 * represents all of the pointers out of our allocated nodes that 554 * point to existing tnodes and the links between our allocated 555 * nodes. 556 */ 557 for (i = child_length(oldtnode), m = 1u << tn->pos; i;) { 558 struct key_vector *inode = get_child(oldtnode, --i); 559 struct key_vector *node0, *node1; 560 unsigned long j, k; 561 562 /* An empty child */ 563 if (!inode) 564 continue; 565 566 /* A leaf or an internal node with skipped bits */ 567 if (!tnode_full(oldtnode, inode)) { 568 put_child(tn, get_index(inode->key, tn), inode); 569 continue; 570 } 571 572 /* drop the node in the old tnode free list */ 573 tnode_free_append(oldtnode, inode); 574 575 /* An internal node with two children */ 576 if (inode->bits == 1) { 577 put_child(tn, 2 * i + 1, get_child(inode, 1)); 578 put_child(tn, 2 * i, get_child(inode, 0)); 579 continue; 580 } 581 582 /* We will replace this node 'inode' with two new 583 * ones, 'node0' and 'node1', each with half of the 584 * original children. The two new nodes will have 585 * a position one bit further down the key and this 586 * means that the "significant" part of their keys 587 * (see the discussion near the top of this file) 588 * will differ by one bit, which will be "0" in 589 * node0's key and "1" in node1's key. Since we are 590 * moving the key position by one step, the bit that 591 * we are moving away from - the bit at position 592 * (tn->pos) - is the one that will differ between 593 * node0 and node1. So... we synthesize that bit in the 594 * two new keys. 595 */ 596 node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1); 597 if (!node1) 598 goto nomem; 599 node0 = tnode_new(inode->key, inode->pos, inode->bits - 1); 600 601 tnode_free_append(tn, node1); 602 if (!node0) 603 goto nomem; 604 tnode_free_append(tn, node0); 605 606 /* populate child pointers in new nodes */ 607 for (k = child_length(inode), j = k / 2; j;) { 608 put_child(node1, --j, get_child(inode, --k)); 609 put_child(node0, j, get_child(inode, j)); 610 put_child(node1, --j, get_child(inode, --k)); 611 put_child(node0, j, get_child(inode, j)); 612 } 613 614 /* link new nodes to parent */ 615 NODE_INIT_PARENT(node1, tn); 616 NODE_INIT_PARENT(node0, tn); 617 618 /* link parent to nodes */ 619 put_child(tn, 2 * i + 1, node1); 620 put_child(tn, 2 * i, node0); 621 } 622 623 /* setup the parent pointers into and out of this node */ 624 return replace(t, oldtnode, tn); 625 nomem: 626 /* all pointers should be clean so we are done */ 627 tnode_free(tn); 628 notnode: 629 return NULL; 630 } 631 632 static struct key_vector *halve(struct trie *t, 633 struct key_vector *oldtnode) 634 { 635 struct key_vector *tn; 636 unsigned long i; 637 638 pr_debug("In halve\n"); 639 640 tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1); 641 if (!tn) 642 goto notnode; 643 644 /* prepare oldtnode to be freed */ 645 tnode_free_init(oldtnode); 646 647 /* Assemble all of the pointers in our cluster, in this case that 648 * represents all of the pointers out of our allocated nodes that 649 * point to existing tnodes and the links between our allocated 650 * nodes. 651 */ 652 for (i = child_length(oldtnode); i;) { 653 struct key_vector *node1 = get_child(oldtnode, --i); 654 struct key_vector *node0 = get_child(oldtnode, --i); 655 struct key_vector *inode; 656 657 /* At least one of the children is empty */ 658 if (!node1 || !node0) { 659 put_child(tn, i / 2, node1 ? : node0); 660 continue; 661 } 662 663 /* Two nonempty children */ 664 inode = tnode_new(node0->key, oldtnode->pos, 1); 665 if (!inode) 666 goto nomem; 667 tnode_free_append(tn, inode); 668 669 /* initialize pointers out of node */ 670 put_child(inode, 1, node1); 671 put_child(inode, 0, node0); 672 NODE_INIT_PARENT(inode, tn); 673 674 /* link parent to node */ 675 put_child(tn, i / 2, inode); 676 } 677 678 /* setup the parent pointers into and out of this node */ 679 return replace(t, oldtnode, tn); 680 nomem: 681 /* all pointers should be clean so we are done */ 682 tnode_free(tn); 683 notnode: 684 return NULL; 685 } 686 687 static struct key_vector *collapse(struct trie *t, 688 struct key_vector *oldtnode) 689 { 690 struct key_vector *n, *tp; 691 unsigned long i; 692 693 /* scan the tnode looking for that one child that might still exist */ 694 for (n = NULL, i = child_length(oldtnode); !n && i;) 695 n = get_child(oldtnode, --i); 696 697 /* compress one level */ 698 tp = node_parent(oldtnode); 699 put_child_root(tp, oldtnode->key, n); 700 node_set_parent(n, tp); 701 702 /* drop dead node */ 703 node_free(oldtnode); 704 705 return tp; 706 } 707 708 static unsigned char update_suffix(struct key_vector *tn) 709 { 710 unsigned char slen = tn->pos; 711 unsigned long stride, i; 712 unsigned char slen_max; 713 714 /* only vector 0 can have a suffix length greater than or equal to 715 * tn->pos + tn->bits, the second highest node will have a suffix 716 * length at most of tn->pos + tn->bits - 1 717 */ 718 slen_max = min_t(unsigned char, tn->pos + tn->bits - 1, tn->slen); 719 720 /* search though the list of children looking for nodes that might 721 * have a suffix greater than the one we currently have. This is 722 * why we start with a stride of 2 since a stride of 1 would 723 * represent the nodes with suffix length equal to tn->pos 724 */ 725 for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) { 726 struct key_vector *n = get_child(tn, i); 727 728 if (!n || (n->slen <= slen)) 729 continue; 730 731 /* update stride and slen based on new value */ 732 stride <<= (n->slen - slen); 733 slen = n->slen; 734 i &= ~(stride - 1); 735 736 /* stop searching if we have hit the maximum possible value */ 737 if (slen >= slen_max) 738 break; 739 } 740 741 tn->slen = slen; 742 743 return slen; 744 } 745 746 /* From "Implementing a dynamic compressed trie" by Stefan Nilsson of 747 * the Helsinki University of Technology and Matti Tikkanen of Nokia 748 * Telecommunications, page 6: 749 * "A node is doubled if the ratio of non-empty children to all 750 * children in the *doubled* node is at least 'high'." 751 * 752 * 'high' in this instance is the variable 'inflate_threshold'. It 753 * is expressed as a percentage, so we multiply it with 754 * child_length() and instead of multiplying by 2 (since the 755 * child array will be doubled by inflate()) and multiplying 756 * the left-hand side by 100 (to handle the percentage thing) we 757 * multiply the left-hand side by 50. 758 * 759 * The left-hand side may look a bit weird: child_length(tn) 760 * - tn->empty_children is of course the number of non-null children 761 * in the current node. tn->full_children is the number of "full" 762 * children, that is non-null tnodes with a skip value of 0. 763 * All of those will be doubled in the resulting inflated tnode, so 764 * we just count them one extra time here. 765 * 766 * A clearer way to write this would be: 767 * 768 * to_be_doubled = tn->full_children; 769 * not_to_be_doubled = child_length(tn) - tn->empty_children - 770 * tn->full_children; 771 * 772 * new_child_length = child_length(tn) * 2; 773 * 774 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) / 775 * new_child_length; 776 * if (new_fill_factor >= inflate_threshold) 777 * 778 * ...and so on, tho it would mess up the while () loop. 779 * 780 * anyway, 781 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >= 782 * inflate_threshold 783 * 784 * avoid a division: 785 * 100 * (not_to_be_doubled + 2*to_be_doubled) >= 786 * inflate_threshold * new_child_length 787 * 788 * expand not_to_be_doubled and to_be_doubled, and shorten: 789 * 100 * (child_length(tn) - tn->empty_children + 790 * tn->full_children) >= inflate_threshold * new_child_length 791 * 792 * expand new_child_length: 793 * 100 * (child_length(tn) - tn->empty_children + 794 * tn->full_children) >= 795 * inflate_threshold * child_length(tn) * 2 796 * 797 * shorten again: 798 * 50 * (tn->full_children + child_length(tn) - 799 * tn->empty_children) >= inflate_threshold * 800 * child_length(tn) 801 * 802 */ 803 static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn) 804 { 805 unsigned long used = child_length(tn); 806 unsigned long threshold = used; 807 808 /* Keep root node larger */ 809 threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold; 810 used -= tn_info(tn)->empty_children; 811 used += tn_info(tn)->full_children; 812 813 /* if bits == KEYLENGTH then pos = 0, and will fail below */ 814 815 return (used > 1) && tn->pos && ((50 * used) >= threshold); 816 } 817 818 static inline bool should_halve(struct key_vector *tp, struct key_vector *tn) 819 { 820 unsigned long used = child_length(tn); 821 unsigned long threshold = used; 822 823 /* Keep root node larger */ 824 threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold; 825 used -= tn_info(tn)->empty_children; 826 827 /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */ 828 829 return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold); 830 } 831 832 static inline bool should_collapse(struct key_vector *tn) 833 { 834 unsigned long used = child_length(tn); 835 836 used -= tn_info(tn)->empty_children; 837 838 /* account for bits == KEYLENGTH case */ 839 if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children) 840 used -= KEY_MAX; 841 842 /* One child or none, time to drop us from the trie */ 843 return used < 2; 844 } 845 846 #define MAX_WORK 10 847 static struct key_vector *resize(struct trie *t, struct key_vector *tn) 848 { 849 #ifdef CONFIG_IP_FIB_TRIE_STATS 850 struct trie_use_stats __percpu *stats = t->stats; 851 #endif 852 struct key_vector *tp = node_parent(tn); 853 unsigned long cindex = get_index(tn->key, tp); 854 int max_work = MAX_WORK; 855 856 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n", 857 tn, inflate_threshold, halve_threshold); 858 859 /* track the tnode via the pointer from the parent instead of 860 * doing it ourselves. This way we can let RCU fully do its 861 * thing without us interfering 862 */ 863 BUG_ON(tn != get_child(tp, cindex)); 864 865 /* Double as long as the resulting node has a number of 866 * nonempty nodes that are above the threshold. 867 */ 868 while (should_inflate(tp, tn) && max_work) { 869 tp = inflate(t, tn); 870 if (!tp) { 871 #ifdef CONFIG_IP_FIB_TRIE_STATS 872 this_cpu_inc(stats->resize_node_skipped); 873 #endif 874 break; 875 } 876 877 max_work--; 878 tn = get_child(tp, cindex); 879 } 880 881 /* update parent in case inflate failed */ 882 tp = node_parent(tn); 883 884 /* Return if at least one inflate is run */ 885 if (max_work != MAX_WORK) 886 return tp; 887 888 /* Halve as long as the number of empty children in this 889 * node is above threshold. 890 */ 891 while (should_halve(tp, tn) && max_work) { 892 tp = halve(t, tn); 893 if (!tp) { 894 #ifdef CONFIG_IP_FIB_TRIE_STATS 895 this_cpu_inc(stats->resize_node_skipped); 896 #endif 897 break; 898 } 899 900 max_work--; 901 tn = get_child(tp, cindex); 902 } 903 904 /* Only one child remains */ 905 if (should_collapse(tn)) 906 return collapse(t, tn); 907 908 /* update parent in case halve failed */ 909 return node_parent(tn); 910 } 911 912 static void node_pull_suffix(struct key_vector *tn, unsigned char slen) 913 { 914 unsigned char node_slen = tn->slen; 915 916 while ((node_slen > tn->pos) && (node_slen > slen)) { 917 slen = update_suffix(tn); 918 if (node_slen == slen) 919 break; 920 921 tn = node_parent(tn); 922 node_slen = tn->slen; 923 } 924 } 925 926 static void node_push_suffix(struct key_vector *tn, unsigned char slen) 927 { 928 while (tn->slen < slen) { 929 tn->slen = slen; 930 tn = node_parent(tn); 931 } 932 } 933 934 /* rcu_read_lock needs to be hold by caller from readside */ 935 static struct key_vector *fib_find_node(struct trie *t, 936 struct key_vector **tp, u32 key) 937 { 938 struct key_vector *pn, *n = t->kv; 939 unsigned long index = 0; 940 941 do { 942 pn = n; 943 n = get_child_rcu(n, index); 944 945 if (!n) 946 break; 947 948 index = get_cindex(key, n); 949 950 /* This bit of code is a bit tricky but it combines multiple 951 * checks into a single check. The prefix consists of the 952 * prefix plus zeros for the bits in the cindex. The index 953 * is the difference between the key and this value. From 954 * this we can actually derive several pieces of data. 955 * if (index >= (1ul << bits)) 956 * we have a mismatch in skip bits and failed 957 * else 958 * we know the value is cindex 959 * 960 * This check is safe even if bits == KEYLENGTH due to the 961 * fact that we can only allocate a node with 32 bits if a 962 * long is greater than 32 bits. 963 */ 964 if (index >= (1ul << n->bits)) { 965 n = NULL; 966 break; 967 } 968 969 /* keep searching until we find a perfect match leaf or NULL */ 970 } while (IS_TNODE(n)); 971 972 *tp = pn; 973 974 return n; 975 } 976 977 /* Return the first fib alias matching DSCP with 978 * priority less than or equal to PRIO. 979 * If 'find_first' is set, return the first matching 980 * fib alias, regardless of DSCP and priority. 981 */ 982 static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen, 983 dscp_t dscp, u32 prio, u32 tb_id, 984 bool find_first) 985 { 986 struct fib_alias *fa; 987 988 if (!fah) 989 return NULL; 990 991 hlist_for_each_entry(fa, fah, fa_list) { 992 /* Avoid Sparse warning when using dscp_t in inequalities */ 993 u8 __fa_dscp = inet_dscp_to_dsfield(fa->fa_dscp); 994 u8 __dscp = inet_dscp_to_dsfield(dscp); 995 996 if (fa->fa_slen < slen) 997 continue; 998 if (fa->fa_slen != slen) 999 break; 1000 if (fa->tb_id > tb_id) 1001 continue; 1002 if (fa->tb_id != tb_id) 1003 break; 1004 if (find_first) 1005 return fa; 1006 if (__fa_dscp > __dscp) 1007 continue; 1008 if (fa->fa_info->fib_priority >= prio || __fa_dscp < __dscp) 1009 return fa; 1010 } 1011 1012 return NULL; 1013 } 1014 1015 static struct fib_alias * 1016 fib_find_matching_alias(struct net *net, const struct fib_rt_info *fri) 1017 { 1018 u8 slen = KEYLENGTH - fri->dst_len; 1019 struct key_vector *l, *tp; 1020 struct fib_table *tb; 1021 struct fib_alias *fa; 1022 struct trie *t; 1023 1024 tb = fib_get_table(net, fri->tb_id); 1025 if (!tb) 1026 return NULL; 1027 1028 t = (struct trie *)tb->tb_data; 1029 l = fib_find_node(t, &tp, be32_to_cpu(fri->dst)); 1030 if (!l) 1031 return NULL; 1032 1033 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 1034 if (fa->fa_slen == slen && fa->tb_id == fri->tb_id && 1035 fa->fa_dscp == fri->dscp && fa->fa_info == fri->fi && 1036 fa->fa_type == fri->type) 1037 return fa; 1038 } 1039 1040 return NULL; 1041 } 1042 1043 void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri) 1044 { 1045 u8 fib_notify_on_flag_change; 1046 struct fib_alias *fa_match; 1047 struct sk_buff *skb; 1048 int err; 1049 1050 rcu_read_lock(); 1051 1052 fa_match = fib_find_matching_alias(net, fri); 1053 if (!fa_match) 1054 goto out; 1055 1056 /* These are paired with the WRITE_ONCE() happening in this function. 1057 * The reason is that we are only protected by RCU at this point. 1058 */ 1059 if (READ_ONCE(fa_match->offload) == fri->offload && 1060 READ_ONCE(fa_match->trap) == fri->trap && 1061 READ_ONCE(fa_match->offload_failed) == fri->offload_failed) 1062 goto out; 1063 1064 WRITE_ONCE(fa_match->offload, fri->offload); 1065 WRITE_ONCE(fa_match->trap, fri->trap); 1066 1067 fib_notify_on_flag_change = READ_ONCE(net->ipv4.sysctl_fib_notify_on_flag_change); 1068 1069 /* 2 means send notifications only if offload_failed was changed. */ 1070 if (fib_notify_on_flag_change == 2 && 1071 READ_ONCE(fa_match->offload_failed) == fri->offload_failed) 1072 goto out; 1073 1074 WRITE_ONCE(fa_match->offload_failed, fri->offload_failed); 1075 1076 if (!fib_notify_on_flag_change) 1077 goto out; 1078 1079 skb = nlmsg_new(fib_nlmsg_size(fa_match->fa_info), GFP_ATOMIC); 1080 if (!skb) { 1081 err = -ENOBUFS; 1082 goto errout; 1083 } 1084 1085 err = fib_dump_info(skb, 0, 0, RTM_NEWROUTE, fri, 0); 1086 if (err < 0) { 1087 /* -EMSGSIZE implies BUG in fib_nlmsg_size() */ 1088 WARN_ON(err == -EMSGSIZE); 1089 kfree_skb(skb); 1090 goto errout; 1091 } 1092 1093 rtnl_notify(skb, net, 0, RTNLGRP_IPV4_ROUTE, NULL, GFP_ATOMIC); 1094 goto out; 1095 1096 errout: 1097 rtnl_set_sk_err(net, RTNLGRP_IPV4_ROUTE, err); 1098 out: 1099 rcu_read_unlock(); 1100 } 1101 EXPORT_SYMBOL_GPL(fib_alias_hw_flags_set); 1102 1103 static void trie_rebalance(struct trie *t, struct key_vector *tn) 1104 { 1105 while (!IS_TRIE(tn)) 1106 tn = resize(t, tn); 1107 } 1108 1109 static int fib_insert_node(struct trie *t, struct key_vector *tp, 1110 struct fib_alias *new, t_key key) 1111 { 1112 struct key_vector *n, *l; 1113 1114 l = leaf_new(key, new); 1115 if (!l) 1116 goto noleaf; 1117 1118 /* retrieve child from parent node */ 1119 n = get_child(tp, get_index(key, tp)); 1120 1121 /* Case 2: n is a LEAF or a TNODE and the key doesn't match. 1122 * 1123 * Add a new tnode here 1124 * first tnode need some special handling 1125 * leaves us in position for handling as case 3 1126 */ 1127 if (n) { 1128 struct key_vector *tn; 1129 1130 tn = tnode_new(key, __fls(key ^ n->key), 1); 1131 if (!tn) 1132 goto notnode; 1133 1134 /* initialize routes out of node */ 1135 NODE_INIT_PARENT(tn, tp); 1136 put_child(tn, get_index(key, tn) ^ 1, n); 1137 1138 /* start adding routes into the node */ 1139 put_child_root(tp, key, tn); 1140 node_set_parent(n, tn); 1141 1142 /* parent now has a NULL spot where the leaf can go */ 1143 tp = tn; 1144 } 1145 1146 /* Case 3: n is NULL, and will just insert a new leaf */ 1147 node_push_suffix(tp, new->fa_slen); 1148 NODE_INIT_PARENT(l, tp); 1149 put_child_root(tp, key, l); 1150 trie_rebalance(t, tp); 1151 1152 return 0; 1153 notnode: 1154 node_free(l); 1155 noleaf: 1156 return -ENOMEM; 1157 } 1158 1159 static int fib_insert_alias(struct trie *t, struct key_vector *tp, 1160 struct key_vector *l, struct fib_alias *new, 1161 struct fib_alias *fa, t_key key) 1162 { 1163 if (!l) 1164 return fib_insert_node(t, tp, new, key); 1165 1166 if (fa) { 1167 hlist_add_before_rcu(&new->fa_list, &fa->fa_list); 1168 } else { 1169 struct fib_alias *last; 1170 1171 hlist_for_each_entry(last, &l->leaf, fa_list) { 1172 if (new->fa_slen < last->fa_slen) 1173 break; 1174 if ((new->fa_slen == last->fa_slen) && 1175 (new->tb_id > last->tb_id)) 1176 break; 1177 fa = last; 1178 } 1179 1180 if (fa) 1181 hlist_add_behind_rcu(&new->fa_list, &fa->fa_list); 1182 else 1183 hlist_add_head_rcu(&new->fa_list, &l->leaf); 1184 } 1185 1186 /* if we added to the tail node then we need to update slen */ 1187 if (l->slen < new->fa_slen) { 1188 l->slen = new->fa_slen; 1189 node_push_suffix(tp, new->fa_slen); 1190 } 1191 1192 return 0; 1193 } 1194 1195 static bool fib_valid_key_len(u32 key, u8 plen, struct netlink_ext_ack *extack) 1196 { 1197 if (plen > KEYLENGTH) { 1198 NL_SET_ERR_MSG(extack, "Invalid prefix length"); 1199 return false; 1200 } 1201 1202 if ((plen < KEYLENGTH) && (key << plen)) { 1203 NL_SET_ERR_MSG(extack, 1204 "Invalid prefix for given prefix length"); 1205 return false; 1206 } 1207 1208 return true; 1209 } 1210 1211 static void fib_remove_alias(struct trie *t, struct key_vector *tp, 1212 struct key_vector *l, struct fib_alias *old); 1213 1214 /* Caller must hold RTNL. */ 1215 int fib_table_insert(struct net *net, struct fib_table *tb, 1216 struct fib_config *cfg, struct netlink_ext_ack *extack) 1217 { 1218 struct trie *t = (struct trie *)tb->tb_data; 1219 struct fib_alias *fa, *new_fa; 1220 struct key_vector *l, *tp; 1221 u16 nlflags = NLM_F_EXCL; 1222 struct fib_info *fi; 1223 u8 plen = cfg->fc_dst_len; 1224 u8 slen = KEYLENGTH - plen; 1225 dscp_t dscp; 1226 u32 key; 1227 int err; 1228 1229 key = ntohl(cfg->fc_dst); 1230 1231 if (!fib_valid_key_len(key, plen, extack)) 1232 return -EINVAL; 1233 1234 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen); 1235 1236 fi = fib_create_info(cfg, extack); 1237 if (IS_ERR(fi)) { 1238 err = PTR_ERR(fi); 1239 goto err; 1240 } 1241 1242 dscp = cfg->fc_dscp; 1243 l = fib_find_node(t, &tp, key); 1244 fa = l ? fib_find_alias(&l->leaf, slen, dscp, fi->fib_priority, 1245 tb->tb_id, false) : NULL; 1246 1247 /* Now fa, if non-NULL, points to the first fib alias 1248 * with the same keys [prefix,dscp,priority], if such key already 1249 * exists or to the node before which we will insert new one. 1250 * 1251 * If fa is NULL, we will need to allocate a new one and 1252 * insert to the tail of the section matching the suffix length 1253 * of the new alias. 1254 */ 1255 1256 if (fa && fa->fa_dscp == dscp && 1257 fa->fa_info->fib_priority == fi->fib_priority) { 1258 struct fib_alias *fa_first, *fa_match; 1259 1260 err = -EEXIST; 1261 if (cfg->fc_nlflags & NLM_F_EXCL) 1262 goto out; 1263 1264 nlflags &= ~NLM_F_EXCL; 1265 1266 /* We have 2 goals: 1267 * 1. Find exact match for type, scope, fib_info to avoid 1268 * duplicate routes 1269 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it 1270 */ 1271 fa_match = NULL; 1272 fa_first = fa; 1273 hlist_for_each_entry_from(fa, fa_list) { 1274 if ((fa->fa_slen != slen) || 1275 (fa->tb_id != tb->tb_id) || 1276 (fa->fa_dscp != dscp)) 1277 break; 1278 if (fa->fa_info->fib_priority != fi->fib_priority) 1279 break; 1280 if (fa->fa_type == cfg->fc_type && 1281 fa->fa_info == fi) { 1282 fa_match = fa; 1283 break; 1284 } 1285 } 1286 1287 if (cfg->fc_nlflags & NLM_F_REPLACE) { 1288 struct fib_info *fi_drop; 1289 u8 state; 1290 1291 nlflags |= NLM_F_REPLACE; 1292 fa = fa_first; 1293 if (fa_match) { 1294 if (fa == fa_match) 1295 err = 0; 1296 goto out; 1297 } 1298 err = -ENOBUFS; 1299 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1300 if (!new_fa) 1301 goto out; 1302 1303 fi_drop = fa->fa_info; 1304 new_fa->fa_dscp = fa->fa_dscp; 1305 new_fa->fa_info = fi; 1306 new_fa->fa_type = cfg->fc_type; 1307 state = fa->fa_state; 1308 new_fa->fa_state = state & ~FA_S_ACCESSED; 1309 new_fa->fa_slen = fa->fa_slen; 1310 new_fa->tb_id = tb->tb_id; 1311 new_fa->fa_default = -1; 1312 new_fa->offload = 0; 1313 new_fa->trap = 0; 1314 new_fa->offload_failed = 0; 1315 1316 hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list); 1317 1318 if (fib_find_alias(&l->leaf, fa->fa_slen, 0, 0, 1319 tb->tb_id, true) == new_fa) { 1320 enum fib_event_type fib_event; 1321 1322 fib_event = FIB_EVENT_ENTRY_REPLACE; 1323 err = call_fib_entry_notifiers(net, fib_event, 1324 key, plen, 1325 new_fa, extack); 1326 if (err) { 1327 hlist_replace_rcu(&new_fa->fa_list, 1328 &fa->fa_list); 1329 goto out_free_new_fa; 1330 } 1331 } 1332 1333 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, 1334 tb->tb_id, &cfg->fc_nlinfo, nlflags); 1335 1336 alias_free_mem_rcu(fa); 1337 1338 fib_release_info(fi_drop); 1339 if (state & FA_S_ACCESSED) 1340 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1341 1342 goto succeeded; 1343 } 1344 /* Error if we find a perfect match which 1345 * uses the same scope, type, and nexthop 1346 * information. 1347 */ 1348 if (fa_match) 1349 goto out; 1350 1351 if (cfg->fc_nlflags & NLM_F_APPEND) 1352 nlflags |= NLM_F_APPEND; 1353 else 1354 fa = fa_first; 1355 } 1356 err = -ENOENT; 1357 if (!(cfg->fc_nlflags & NLM_F_CREATE)) 1358 goto out; 1359 1360 nlflags |= NLM_F_CREATE; 1361 err = -ENOBUFS; 1362 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1363 if (!new_fa) 1364 goto out; 1365 1366 new_fa->fa_info = fi; 1367 new_fa->fa_dscp = dscp; 1368 new_fa->fa_type = cfg->fc_type; 1369 new_fa->fa_state = 0; 1370 new_fa->fa_slen = slen; 1371 new_fa->tb_id = tb->tb_id; 1372 new_fa->fa_default = -1; 1373 new_fa->offload = 0; 1374 new_fa->trap = 0; 1375 new_fa->offload_failed = 0; 1376 1377 /* Insert new entry to the list. */ 1378 err = fib_insert_alias(t, tp, l, new_fa, fa, key); 1379 if (err) 1380 goto out_free_new_fa; 1381 1382 /* The alias was already inserted, so the node must exist. */ 1383 l = l ? l : fib_find_node(t, &tp, key); 1384 if (WARN_ON_ONCE(!l)) { 1385 err = -ENOENT; 1386 goto out_free_new_fa; 1387 } 1388 1389 if (fib_find_alias(&l->leaf, new_fa->fa_slen, 0, 0, tb->tb_id, true) == 1390 new_fa) { 1391 enum fib_event_type fib_event; 1392 1393 fib_event = FIB_EVENT_ENTRY_REPLACE; 1394 err = call_fib_entry_notifiers(net, fib_event, key, plen, 1395 new_fa, extack); 1396 if (err) 1397 goto out_remove_new_fa; 1398 } 1399 1400 if (!plen) 1401 tb->tb_num_default++; 1402 1403 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1404 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id, 1405 &cfg->fc_nlinfo, nlflags); 1406 succeeded: 1407 return 0; 1408 1409 out_remove_new_fa: 1410 fib_remove_alias(t, tp, l, new_fa); 1411 out_free_new_fa: 1412 kmem_cache_free(fn_alias_kmem, new_fa); 1413 out: 1414 fib_release_info(fi); 1415 err: 1416 return err; 1417 } 1418 1419 static inline t_key prefix_mismatch(t_key key, struct key_vector *n) 1420 { 1421 t_key prefix = n->key; 1422 1423 return (key ^ prefix) & (prefix | -prefix); 1424 } 1425 1426 bool fib_lookup_good_nhc(const struct fib_nh_common *nhc, int fib_flags, 1427 const struct flowi4 *flp) 1428 { 1429 if (nhc->nhc_flags & RTNH_F_DEAD) 1430 return false; 1431 1432 if (ip_ignore_linkdown(nhc->nhc_dev) && 1433 nhc->nhc_flags & RTNH_F_LINKDOWN && 1434 !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE)) 1435 return false; 1436 1437 if (flp->flowi4_oif && flp->flowi4_oif != nhc->nhc_oif) 1438 return false; 1439 1440 return true; 1441 } 1442 1443 /* should be called with rcu_read_lock */ 1444 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 1445 struct fib_result *res, int fib_flags) 1446 { 1447 struct trie *t = (struct trie *) tb->tb_data; 1448 #ifdef CONFIG_IP_FIB_TRIE_STATS 1449 struct trie_use_stats __percpu *stats = t->stats; 1450 #endif 1451 const t_key key = ntohl(flp->daddr); 1452 struct key_vector *n, *pn; 1453 struct fib_alias *fa; 1454 unsigned long index; 1455 t_key cindex; 1456 1457 pn = t->kv; 1458 cindex = 0; 1459 1460 n = get_child_rcu(pn, cindex); 1461 if (!n) { 1462 trace_fib_table_lookup(tb->tb_id, flp, NULL, -EAGAIN); 1463 return -EAGAIN; 1464 } 1465 1466 #ifdef CONFIG_IP_FIB_TRIE_STATS 1467 this_cpu_inc(stats->gets); 1468 #endif 1469 1470 /* Step 1: Travel to the longest prefix match in the trie */ 1471 for (;;) { 1472 index = get_cindex(key, n); 1473 1474 /* This bit of code is a bit tricky but it combines multiple 1475 * checks into a single check. The prefix consists of the 1476 * prefix plus zeros for the "bits" in the prefix. The index 1477 * is the difference between the key and this value. From 1478 * this we can actually derive several pieces of data. 1479 * if (index >= (1ul << bits)) 1480 * we have a mismatch in skip bits and failed 1481 * else 1482 * we know the value is cindex 1483 * 1484 * This check is safe even if bits == KEYLENGTH due to the 1485 * fact that we can only allocate a node with 32 bits if a 1486 * long is greater than 32 bits. 1487 */ 1488 if (index >= (1ul << n->bits)) 1489 break; 1490 1491 /* we have found a leaf. Prefixes have already been compared */ 1492 if (IS_LEAF(n)) 1493 goto found; 1494 1495 /* only record pn and cindex if we are going to be chopping 1496 * bits later. Otherwise we are just wasting cycles. 1497 */ 1498 if (n->slen > n->pos) { 1499 pn = n; 1500 cindex = index; 1501 } 1502 1503 n = get_child_rcu(n, index); 1504 if (unlikely(!n)) 1505 goto backtrace; 1506 } 1507 1508 /* Step 2: Sort out leaves and begin backtracing for longest prefix */ 1509 for (;;) { 1510 /* record the pointer where our next node pointer is stored */ 1511 struct key_vector __rcu **cptr = n->tnode; 1512 1513 /* This test verifies that none of the bits that differ 1514 * between the key and the prefix exist in the region of 1515 * the lsb and higher in the prefix. 1516 */ 1517 if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos)) 1518 goto backtrace; 1519 1520 /* exit out and process leaf */ 1521 if (unlikely(IS_LEAF(n))) 1522 break; 1523 1524 /* Don't bother recording parent info. Since we are in 1525 * prefix match mode we will have to come back to wherever 1526 * we started this traversal anyway 1527 */ 1528 1529 while ((n = rcu_dereference(*cptr)) == NULL) { 1530 backtrace: 1531 #ifdef CONFIG_IP_FIB_TRIE_STATS 1532 if (!n) 1533 this_cpu_inc(stats->null_node_hit); 1534 #endif 1535 /* If we are at cindex 0 there are no more bits for 1536 * us to strip at this level so we must ascend back 1537 * up one level to see if there are any more bits to 1538 * be stripped there. 1539 */ 1540 while (!cindex) { 1541 t_key pkey = pn->key; 1542 1543 /* If we don't have a parent then there is 1544 * nothing for us to do as we do not have any 1545 * further nodes to parse. 1546 */ 1547 if (IS_TRIE(pn)) { 1548 trace_fib_table_lookup(tb->tb_id, flp, 1549 NULL, -EAGAIN); 1550 return -EAGAIN; 1551 } 1552 #ifdef CONFIG_IP_FIB_TRIE_STATS 1553 this_cpu_inc(stats->backtrack); 1554 #endif 1555 /* Get Child's index */ 1556 pn = node_parent_rcu(pn); 1557 cindex = get_index(pkey, pn); 1558 } 1559 1560 /* strip the least significant bit from the cindex */ 1561 cindex &= cindex - 1; 1562 1563 /* grab pointer for next child node */ 1564 cptr = &pn->tnode[cindex]; 1565 } 1566 } 1567 1568 found: 1569 /* this line carries forward the xor from earlier in the function */ 1570 index = key ^ n->key; 1571 1572 /* Step 3: Process the leaf, if that fails fall back to backtracing */ 1573 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) { 1574 struct fib_info *fi = fa->fa_info; 1575 struct fib_nh_common *nhc; 1576 int nhsel, err; 1577 1578 if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) { 1579 if (index >= (1ul << fa->fa_slen)) 1580 continue; 1581 } 1582 if (fa->fa_dscp && 1583 inet_dscp_to_dsfield(fa->fa_dscp) != flp->flowi4_tos) 1584 continue; 1585 /* Paired with WRITE_ONCE() in fib_release_info() */ 1586 if (READ_ONCE(fi->fib_dead)) 1587 continue; 1588 if (fa->fa_info->fib_scope < flp->flowi4_scope) 1589 continue; 1590 fib_alias_accessed(fa); 1591 err = fib_props[fa->fa_type].error; 1592 if (unlikely(err < 0)) { 1593 out_reject: 1594 #ifdef CONFIG_IP_FIB_TRIE_STATS 1595 this_cpu_inc(stats->semantic_match_passed); 1596 #endif 1597 trace_fib_table_lookup(tb->tb_id, flp, NULL, err); 1598 return err; 1599 } 1600 if (fi->fib_flags & RTNH_F_DEAD) 1601 continue; 1602 1603 if (unlikely(fi->nh)) { 1604 if (nexthop_is_blackhole(fi->nh)) { 1605 err = fib_props[RTN_BLACKHOLE].error; 1606 goto out_reject; 1607 } 1608 1609 nhc = nexthop_get_nhc_lookup(fi->nh, fib_flags, flp, 1610 &nhsel); 1611 if (nhc) 1612 goto set_result; 1613 goto miss; 1614 } 1615 1616 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) { 1617 nhc = fib_info_nhc(fi, nhsel); 1618 1619 if (!fib_lookup_good_nhc(nhc, fib_flags, flp)) 1620 continue; 1621 set_result: 1622 if (!(fib_flags & FIB_LOOKUP_NOREF)) 1623 refcount_inc(&fi->fib_clntref); 1624 1625 res->prefix = htonl(n->key); 1626 res->prefixlen = KEYLENGTH - fa->fa_slen; 1627 res->nh_sel = nhsel; 1628 res->nhc = nhc; 1629 res->type = fa->fa_type; 1630 res->scope = fi->fib_scope; 1631 res->fi = fi; 1632 res->table = tb; 1633 res->fa_head = &n->leaf; 1634 #ifdef CONFIG_IP_FIB_TRIE_STATS 1635 this_cpu_inc(stats->semantic_match_passed); 1636 #endif 1637 trace_fib_table_lookup(tb->tb_id, flp, nhc, err); 1638 1639 return err; 1640 } 1641 } 1642 miss: 1643 #ifdef CONFIG_IP_FIB_TRIE_STATS 1644 this_cpu_inc(stats->semantic_match_miss); 1645 #endif 1646 goto backtrace; 1647 } 1648 EXPORT_SYMBOL_GPL(fib_table_lookup); 1649 1650 static void fib_remove_alias(struct trie *t, struct key_vector *tp, 1651 struct key_vector *l, struct fib_alias *old) 1652 { 1653 /* record the location of the previous list_info entry */ 1654 struct hlist_node **pprev = old->fa_list.pprev; 1655 struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next); 1656 1657 /* remove the fib_alias from the list */ 1658 hlist_del_rcu(&old->fa_list); 1659 1660 /* if we emptied the list this leaf will be freed and we can sort 1661 * out parent suffix lengths as a part of trie_rebalance 1662 */ 1663 if (hlist_empty(&l->leaf)) { 1664 if (tp->slen == l->slen) 1665 node_pull_suffix(tp, tp->pos); 1666 put_child_root(tp, l->key, NULL); 1667 node_free(l); 1668 trie_rebalance(t, tp); 1669 return; 1670 } 1671 1672 /* only access fa if it is pointing at the last valid hlist_node */ 1673 if (*pprev) 1674 return; 1675 1676 /* update the trie with the latest suffix length */ 1677 l->slen = fa->fa_slen; 1678 node_pull_suffix(tp, fa->fa_slen); 1679 } 1680 1681 static void fib_notify_alias_delete(struct net *net, u32 key, 1682 struct hlist_head *fah, 1683 struct fib_alias *fa_to_delete, 1684 struct netlink_ext_ack *extack) 1685 { 1686 struct fib_alias *fa_next, *fa_to_notify; 1687 u32 tb_id = fa_to_delete->tb_id; 1688 u8 slen = fa_to_delete->fa_slen; 1689 enum fib_event_type fib_event; 1690 1691 /* Do not notify if we do not care about the route. */ 1692 if (fib_find_alias(fah, slen, 0, 0, tb_id, true) != fa_to_delete) 1693 return; 1694 1695 /* Determine if the route should be replaced by the next route in the 1696 * list. 1697 */ 1698 fa_next = hlist_entry_safe(fa_to_delete->fa_list.next, 1699 struct fib_alias, fa_list); 1700 if (fa_next && fa_next->fa_slen == slen && fa_next->tb_id == tb_id) { 1701 fib_event = FIB_EVENT_ENTRY_REPLACE; 1702 fa_to_notify = fa_next; 1703 } else { 1704 fib_event = FIB_EVENT_ENTRY_DEL; 1705 fa_to_notify = fa_to_delete; 1706 } 1707 call_fib_entry_notifiers(net, fib_event, key, KEYLENGTH - slen, 1708 fa_to_notify, extack); 1709 } 1710 1711 /* Caller must hold RTNL. */ 1712 int fib_table_delete(struct net *net, struct fib_table *tb, 1713 struct fib_config *cfg, struct netlink_ext_ack *extack) 1714 { 1715 struct trie *t = (struct trie *) tb->tb_data; 1716 struct fib_alias *fa, *fa_to_delete; 1717 struct key_vector *l, *tp; 1718 u8 plen = cfg->fc_dst_len; 1719 u8 slen = KEYLENGTH - plen; 1720 dscp_t dscp; 1721 u32 key; 1722 1723 key = ntohl(cfg->fc_dst); 1724 1725 if (!fib_valid_key_len(key, plen, extack)) 1726 return -EINVAL; 1727 1728 l = fib_find_node(t, &tp, key); 1729 if (!l) 1730 return -ESRCH; 1731 1732 dscp = cfg->fc_dscp; 1733 fa = fib_find_alias(&l->leaf, slen, dscp, 0, tb->tb_id, false); 1734 if (!fa) 1735 return -ESRCH; 1736 1737 pr_debug("Deleting %08x/%d dsfield=0x%02x t=%p\n", key, plen, 1738 inet_dscp_to_dsfield(dscp), t); 1739 1740 fa_to_delete = NULL; 1741 hlist_for_each_entry_from(fa, fa_list) { 1742 struct fib_info *fi = fa->fa_info; 1743 1744 if ((fa->fa_slen != slen) || 1745 (fa->tb_id != tb->tb_id) || 1746 (fa->fa_dscp != dscp)) 1747 break; 1748 1749 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) && 1750 (cfg->fc_scope == RT_SCOPE_NOWHERE || 1751 fa->fa_info->fib_scope == cfg->fc_scope) && 1752 (!cfg->fc_prefsrc || 1753 fi->fib_prefsrc == cfg->fc_prefsrc) && 1754 (!cfg->fc_protocol || 1755 fi->fib_protocol == cfg->fc_protocol) && 1756 fib_nh_match(net, cfg, fi, extack) == 0 && 1757 fib_metrics_match(cfg, fi)) { 1758 fa_to_delete = fa; 1759 break; 1760 } 1761 } 1762 1763 if (!fa_to_delete) 1764 return -ESRCH; 1765 1766 fib_notify_alias_delete(net, key, &l->leaf, fa_to_delete, extack); 1767 rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id, 1768 &cfg->fc_nlinfo, 0); 1769 1770 if (!plen) 1771 tb->tb_num_default--; 1772 1773 fib_remove_alias(t, tp, l, fa_to_delete); 1774 1775 if (fa_to_delete->fa_state & FA_S_ACCESSED) 1776 rt_cache_flush(cfg->fc_nlinfo.nl_net); 1777 1778 fib_release_info(fa_to_delete->fa_info); 1779 alias_free_mem_rcu(fa_to_delete); 1780 return 0; 1781 } 1782 1783 /* Scan for the next leaf starting at the provided key value */ 1784 static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key) 1785 { 1786 struct key_vector *pn, *n = *tn; 1787 unsigned long cindex; 1788 1789 /* this loop is meant to try and find the key in the trie */ 1790 do { 1791 /* record parent and next child index */ 1792 pn = n; 1793 cindex = (key > pn->key) ? get_index(key, pn) : 0; 1794 1795 if (cindex >> pn->bits) 1796 break; 1797 1798 /* descend into the next child */ 1799 n = get_child_rcu(pn, cindex++); 1800 if (!n) 1801 break; 1802 1803 /* guarantee forward progress on the keys */ 1804 if (IS_LEAF(n) && (n->key >= key)) 1805 goto found; 1806 } while (IS_TNODE(n)); 1807 1808 /* this loop will search for the next leaf with a greater key */ 1809 while (!IS_TRIE(pn)) { 1810 /* if we exhausted the parent node we will need to climb */ 1811 if (cindex >= (1ul << pn->bits)) { 1812 t_key pkey = pn->key; 1813 1814 pn = node_parent_rcu(pn); 1815 cindex = get_index(pkey, pn) + 1; 1816 continue; 1817 } 1818 1819 /* grab the next available node */ 1820 n = get_child_rcu(pn, cindex++); 1821 if (!n) 1822 continue; 1823 1824 /* no need to compare keys since we bumped the index */ 1825 if (IS_LEAF(n)) 1826 goto found; 1827 1828 /* Rescan start scanning in new node */ 1829 pn = n; 1830 cindex = 0; 1831 } 1832 1833 *tn = pn; 1834 return NULL; /* Root of trie */ 1835 found: 1836 /* if we are at the limit for keys just return NULL for the tnode */ 1837 *tn = pn; 1838 return n; 1839 } 1840 1841 static void fib_trie_free(struct fib_table *tb) 1842 { 1843 struct trie *t = (struct trie *)tb->tb_data; 1844 struct key_vector *pn = t->kv; 1845 unsigned long cindex = 1; 1846 struct hlist_node *tmp; 1847 struct fib_alias *fa; 1848 1849 /* walk trie in reverse order and free everything */ 1850 for (;;) { 1851 struct key_vector *n; 1852 1853 if (!(cindex--)) { 1854 t_key pkey = pn->key; 1855 1856 if (IS_TRIE(pn)) 1857 break; 1858 1859 n = pn; 1860 pn = node_parent(pn); 1861 1862 /* drop emptied tnode */ 1863 put_child_root(pn, n->key, NULL); 1864 node_free(n); 1865 1866 cindex = get_index(pkey, pn); 1867 1868 continue; 1869 } 1870 1871 /* grab the next available node */ 1872 n = get_child(pn, cindex); 1873 if (!n) 1874 continue; 1875 1876 if (IS_TNODE(n)) { 1877 /* record pn and cindex for leaf walking */ 1878 pn = n; 1879 cindex = 1ul << n->bits; 1880 1881 continue; 1882 } 1883 1884 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 1885 hlist_del_rcu(&fa->fa_list); 1886 alias_free_mem_rcu(fa); 1887 } 1888 1889 put_child_root(pn, n->key, NULL); 1890 node_free(n); 1891 } 1892 1893 #ifdef CONFIG_IP_FIB_TRIE_STATS 1894 free_percpu(t->stats); 1895 #endif 1896 kfree(tb); 1897 } 1898 1899 struct fib_table *fib_trie_unmerge(struct fib_table *oldtb) 1900 { 1901 struct trie *ot = (struct trie *)oldtb->tb_data; 1902 struct key_vector *l, *tp = ot->kv; 1903 struct fib_table *local_tb; 1904 struct fib_alias *fa; 1905 struct trie *lt; 1906 t_key key = 0; 1907 1908 if (oldtb->tb_data == oldtb->__data) 1909 return oldtb; 1910 1911 local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL); 1912 if (!local_tb) 1913 return NULL; 1914 1915 lt = (struct trie *)local_tb->tb_data; 1916 1917 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 1918 struct key_vector *local_l = NULL, *local_tp; 1919 1920 hlist_for_each_entry(fa, &l->leaf, fa_list) { 1921 struct fib_alias *new_fa; 1922 1923 if (local_tb->tb_id != fa->tb_id) 1924 continue; 1925 1926 /* clone fa for new local table */ 1927 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); 1928 if (!new_fa) 1929 goto out; 1930 1931 memcpy(new_fa, fa, sizeof(*fa)); 1932 1933 /* insert clone into table */ 1934 if (!local_l) 1935 local_l = fib_find_node(lt, &local_tp, l->key); 1936 1937 if (fib_insert_alias(lt, local_tp, local_l, new_fa, 1938 NULL, l->key)) { 1939 kmem_cache_free(fn_alias_kmem, new_fa); 1940 goto out; 1941 } 1942 } 1943 1944 /* stop loop if key wrapped back to 0 */ 1945 key = l->key + 1; 1946 if (key < l->key) 1947 break; 1948 } 1949 1950 return local_tb; 1951 out: 1952 fib_trie_free(local_tb); 1953 1954 return NULL; 1955 } 1956 1957 /* Caller must hold RTNL */ 1958 void fib_table_flush_external(struct fib_table *tb) 1959 { 1960 struct trie *t = (struct trie *)tb->tb_data; 1961 struct key_vector *pn = t->kv; 1962 unsigned long cindex = 1; 1963 struct hlist_node *tmp; 1964 struct fib_alias *fa; 1965 1966 /* walk trie in reverse order */ 1967 for (;;) { 1968 unsigned char slen = 0; 1969 struct key_vector *n; 1970 1971 if (!(cindex--)) { 1972 t_key pkey = pn->key; 1973 1974 /* cannot resize the trie vector */ 1975 if (IS_TRIE(pn)) 1976 break; 1977 1978 /* update the suffix to address pulled leaves */ 1979 if (pn->slen > pn->pos) 1980 update_suffix(pn); 1981 1982 /* resize completed node */ 1983 pn = resize(t, pn); 1984 cindex = get_index(pkey, pn); 1985 1986 continue; 1987 } 1988 1989 /* grab the next available node */ 1990 n = get_child(pn, cindex); 1991 if (!n) 1992 continue; 1993 1994 if (IS_TNODE(n)) { 1995 /* record pn and cindex for leaf walking */ 1996 pn = n; 1997 cindex = 1ul << n->bits; 1998 1999 continue; 2000 } 2001 2002 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 2003 /* if alias was cloned to local then we just 2004 * need to remove the local copy from main 2005 */ 2006 if (tb->tb_id != fa->tb_id) { 2007 hlist_del_rcu(&fa->fa_list); 2008 alias_free_mem_rcu(fa); 2009 continue; 2010 } 2011 2012 /* record local slen */ 2013 slen = fa->fa_slen; 2014 } 2015 2016 /* update leaf slen */ 2017 n->slen = slen; 2018 2019 if (hlist_empty(&n->leaf)) { 2020 put_child_root(pn, n->key, NULL); 2021 node_free(n); 2022 } 2023 } 2024 } 2025 2026 /* Caller must hold RTNL. */ 2027 int fib_table_flush(struct net *net, struct fib_table *tb, bool flush_all) 2028 { 2029 struct trie *t = (struct trie *)tb->tb_data; 2030 struct nl_info info = { .nl_net = net }; 2031 struct key_vector *pn = t->kv; 2032 unsigned long cindex = 1; 2033 struct hlist_node *tmp; 2034 struct fib_alias *fa; 2035 int found = 0; 2036 2037 /* walk trie in reverse order */ 2038 for (;;) { 2039 unsigned char slen = 0; 2040 struct key_vector *n; 2041 2042 if (!(cindex--)) { 2043 t_key pkey = pn->key; 2044 2045 /* cannot resize the trie vector */ 2046 if (IS_TRIE(pn)) 2047 break; 2048 2049 /* update the suffix to address pulled leaves */ 2050 if (pn->slen > pn->pos) 2051 update_suffix(pn); 2052 2053 /* resize completed node */ 2054 pn = resize(t, pn); 2055 cindex = get_index(pkey, pn); 2056 2057 continue; 2058 } 2059 2060 /* grab the next available node */ 2061 n = get_child(pn, cindex); 2062 if (!n) 2063 continue; 2064 2065 if (IS_TNODE(n)) { 2066 /* record pn and cindex for leaf walking */ 2067 pn = n; 2068 cindex = 1ul << n->bits; 2069 2070 continue; 2071 } 2072 2073 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) { 2074 struct fib_info *fi = fa->fa_info; 2075 2076 if (!fi || tb->tb_id != fa->tb_id || 2077 (!(fi->fib_flags & RTNH_F_DEAD) && 2078 !fib_props[fa->fa_type].error)) { 2079 slen = fa->fa_slen; 2080 continue; 2081 } 2082 2083 /* Do not flush error routes if network namespace is 2084 * not being dismantled 2085 */ 2086 if (!flush_all && fib_props[fa->fa_type].error) { 2087 slen = fa->fa_slen; 2088 continue; 2089 } 2090 2091 fib_notify_alias_delete(net, n->key, &n->leaf, fa, 2092 NULL); 2093 if (fi->pfsrc_removed) 2094 rtmsg_fib(RTM_DELROUTE, htonl(n->key), fa, 2095 KEYLENGTH - fa->fa_slen, tb->tb_id, &info, 0); 2096 hlist_del_rcu(&fa->fa_list); 2097 fib_release_info(fa->fa_info); 2098 alias_free_mem_rcu(fa); 2099 found++; 2100 } 2101 2102 /* update leaf slen */ 2103 n->slen = slen; 2104 2105 if (hlist_empty(&n->leaf)) { 2106 put_child_root(pn, n->key, NULL); 2107 node_free(n); 2108 } 2109 } 2110 2111 pr_debug("trie_flush found=%d\n", found); 2112 return found; 2113 } 2114 2115 /* derived from fib_trie_free */ 2116 static void __fib_info_notify_update(struct net *net, struct fib_table *tb, 2117 struct nl_info *info) 2118 { 2119 struct trie *t = (struct trie *)tb->tb_data; 2120 struct key_vector *pn = t->kv; 2121 unsigned long cindex = 1; 2122 struct fib_alias *fa; 2123 2124 for (;;) { 2125 struct key_vector *n; 2126 2127 if (!(cindex--)) { 2128 t_key pkey = pn->key; 2129 2130 if (IS_TRIE(pn)) 2131 break; 2132 2133 pn = node_parent(pn); 2134 cindex = get_index(pkey, pn); 2135 continue; 2136 } 2137 2138 /* grab the next available node */ 2139 n = get_child(pn, cindex); 2140 if (!n) 2141 continue; 2142 2143 if (IS_TNODE(n)) { 2144 /* record pn and cindex for leaf walking */ 2145 pn = n; 2146 cindex = 1ul << n->bits; 2147 2148 continue; 2149 } 2150 2151 hlist_for_each_entry(fa, &n->leaf, fa_list) { 2152 struct fib_info *fi = fa->fa_info; 2153 2154 if (!fi || !fi->nh_updated || fa->tb_id != tb->tb_id) 2155 continue; 2156 2157 rtmsg_fib(RTM_NEWROUTE, htonl(n->key), fa, 2158 KEYLENGTH - fa->fa_slen, tb->tb_id, 2159 info, NLM_F_REPLACE); 2160 } 2161 } 2162 } 2163 2164 void fib_info_notify_update(struct net *net, struct nl_info *info) 2165 { 2166 unsigned int h; 2167 2168 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2169 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2170 struct fib_table *tb; 2171 2172 hlist_for_each_entry_rcu(tb, head, tb_hlist, 2173 lockdep_rtnl_is_held()) 2174 __fib_info_notify_update(net, tb, info); 2175 } 2176 } 2177 2178 static int fib_leaf_notify(struct key_vector *l, struct fib_table *tb, 2179 struct notifier_block *nb, 2180 struct netlink_ext_ack *extack) 2181 { 2182 struct fib_alias *fa; 2183 int last_slen = -1; 2184 int err; 2185 2186 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 2187 struct fib_info *fi = fa->fa_info; 2188 2189 if (!fi) 2190 continue; 2191 2192 /* local and main table can share the same trie, 2193 * so don't notify twice for the same entry. 2194 */ 2195 if (tb->tb_id != fa->tb_id) 2196 continue; 2197 2198 if (fa->fa_slen == last_slen) 2199 continue; 2200 2201 last_slen = fa->fa_slen; 2202 err = call_fib_entry_notifier(nb, FIB_EVENT_ENTRY_REPLACE, 2203 l->key, KEYLENGTH - fa->fa_slen, 2204 fa, extack); 2205 if (err) 2206 return err; 2207 } 2208 return 0; 2209 } 2210 2211 static int fib_table_notify(struct fib_table *tb, struct notifier_block *nb, 2212 struct netlink_ext_ack *extack) 2213 { 2214 struct trie *t = (struct trie *)tb->tb_data; 2215 struct key_vector *l, *tp = t->kv; 2216 t_key key = 0; 2217 int err; 2218 2219 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 2220 err = fib_leaf_notify(l, tb, nb, extack); 2221 if (err) 2222 return err; 2223 2224 key = l->key + 1; 2225 /* stop in case of wrap around */ 2226 if (key < l->key) 2227 break; 2228 } 2229 return 0; 2230 } 2231 2232 int fib_notify(struct net *net, struct notifier_block *nb, 2233 struct netlink_ext_ack *extack) 2234 { 2235 unsigned int h; 2236 int err; 2237 2238 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2239 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2240 struct fib_table *tb; 2241 2242 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2243 err = fib_table_notify(tb, nb, extack); 2244 if (err) 2245 return err; 2246 } 2247 } 2248 return 0; 2249 } 2250 2251 static void __trie_free_rcu(struct rcu_head *head) 2252 { 2253 struct fib_table *tb = container_of(head, struct fib_table, rcu); 2254 #ifdef CONFIG_IP_FIB_TRIE_STATS 2255 struct trie *t = (struct trie *)tb->tb_data; 2256 2257 if (tb->tb_data == tb->__data) 2258 free_percpu(t->stats); 2259 #endif /* CONFIG_IP_FIB_TRIE_STATS */ 2260 kfree(tb); 2261 } 2262 2263 void fib_free_table(struct fib_table *tb) 2264 { 2265 call_rcu(&tb->rcu, __trie_free_rcu); 2266 } 2267 2268 static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb, 2269 struct sk_buff *skb, struct netlink_callback *cb, 2270 struct fib_dump_filter *filter) 2271 { 2272 unsigned int flags = NLM_F_MULTI; 2273 __be32 xkey = htonl(l->key); 2274 int i, s_i, i_fa, s_fa, err; 2275 struct fib_alias *fa; 2276 2277 if (filter->filter_set || 2278 !filter->dump_exceptions || !filter->dump_routes) 2279 flags |= NLM_F_DUMP_FILTERED; 2280 2281 s_i = cb->args[4]; 2282 s_fa = cb->args[5]; 2283 i = 0; 2284 2285 /* rcu_read_lock is hold by caller */ 2286 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 2287 struct fib_info *fi = fa->fa_info; 2288 2289 if (i < s_i) 2290 goto next; 2291 2292 i_fa = 0; 2293 2294 if (tb->tb_id != fa->tb_id) 2295 goto next; 2296 2297 if (filter->filter_set) { 2298 if (filter->rt_type && fa->fa_type != filter->rt_type) 2299 goto next; 2300 2301 if ((filter->protocol && 2302 fi->fib_protocol != filter->protocol)) 2303 goto next; 2304 2305 if (filter->dev && 2306 !fib_info_nh_uses_dev(fi, filter->dev)) 2307 goto next; 2308 } 2309 2310 if (filter->dump_routes) { 2311 if (!s_fa) { 2312 struct fib_rt_info fri; 2313 2314 fri.fi = fi; 2315 fri.tb_id = tb->tb_id; 2316 fri.dst = xkey; 2317 fri.dst_len = KEYLENGTH - fa->fa_slen; 2318 fri.dscp = fa->fa_dscp; 2319 fri.type = fa->fa_type; 2320 fri.offload = READ_ONCE(fa->offload); 2321 fri.trap = READ_ONCE(fa->trap); 2322 fri.offload_failed = READ_ONCE(fa->offload_failed); 2323 err = fib_dump_info(skb, 2324 NETLINK_CB(cb->skb).portid, 2325 cb->nlh->nlmsg_seq, 2326 RTM_NEWROUTE, &fri, flags); 2327 if (err < 0) 2328 goto stop; 2329 } 2330 2331 i_fa++; 2332 } 2333 2334 if (filter->dump_exceptions) { 2335 err = fib_dump_info_fnhe(skb, cb, tb->tb_id, fi, 2336 &i_fa, s_fa, flags); 2337 if (err < 0) 2338 goto stop; 2339 } 2340 2341 next: 2342 i++; 2343 } 2344 2345 cb->args[4] = i; 2346 return skb->len; 2347 2348 stop: 2349 cb->args[4] = i; 2350 cb->args[5] = i_fa; 2351 return err; 2352 } 2353 2354 /* rcu_read_lock needs to be hold by caller from readside */ 2355 int fib_table_dump(struct fib_table *tb, struct sk_buff *skb, 2356 struct netlink_callback *cb, struct fib_dump_filter *filter) 2357 { 2358 struct trie *t = (struct trie *)tb->tb_data; 2359 struct key_vector *l, *tp = t->kv; 2360 /* Dump starting at last key. 2361 * Note: 0.0.0.0/0 (ie default) is first key. 2362 */ 2363 int count = cb->args[2]; 2364 t_key key = cb->args[3]; 2365 2366 /* First time here, count and key are both always 0. Count > 0 2367 * and key == 0 means the dump has wrapped around and we are done. 2368 */ 2369 if (count && !key) 2370 return skb->len; 2371 2372 while ((l = leaf_walk_rcu(&tp, key)) != NULL) { 2373 int err; 2374 2375 err = fn_trie_dump_leaf(l, tb, skb, cb, filter); 2376 if (err < 0) { 2377 cb->args[3] = key; 2378 cb->args[2] = count; 2379 return err; 2380 } 2381 2382 ++count; 2383 key = l->key + 1; 2384 2385 memset(&cb->args[4], 0, 2386 sizeof(cb->args) - 4*sizeof(cb->args[0])); 2387 2388 /* stop loop if key wrapped back to 0 */ 2389 if (key < l->key) 2390 break; 2391 } 2392 2393 cb->args[3] = key; 2394 cb->args[2] = count; 2395 2396 return skb->len; 2397 } 2398 2399 void __init fib_trie_init(void) 2400 { 2401 fn_alias_kmem = kmem_cache_create("ip_fib_alias", 2402 sizeof(struct fib_alias), 2403 0, SLAB_PANIC | SLAB_ACCOUNT, NULL); 2404 2405 trie_leaf_kmem = kmem_cache_create("ip_fib_trie", 2406 LEAF_SIZE, 2407 0, SLAB_PANIC | SLAB_ACCOUNT, NULL); 2408 } 2409 2410 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias) 2411 { 2412 struct fib_table *tb; 2413 struct trie *t; 2414 size_t sz = sizeof(*tb); 2415 2416 if (!alias) 2417 sz += sizeof(struct trie); 2418 2419 tb = kzalloc(sz, GFP_KERNEL); 2420 if (!tb) 2421 return NULL; 2422 2423 tb->tb_id = id; 2424 tb->tb_num_default = 0; 2425 tb->tb_data = (alias ? alias->__data : tb->__data); 2426 2427 if (alias) 2428 return tb; 2429 2430 t = (struct trie *) tb->tb_data; 2431 t->kv[0].pos = KEYLENGTH; 2432 t->kv[0].slen = KEYLENGTH; 2433 #ifdef CONFIG_IP_FIB_TRIE_STATS 2434 t->stats = alloc_percpu(struct trie_use_stats); 2435 if (!t->stats) { 2436 kfree(tb); 2437 tb = NULL; 2438 } 2439 #endif 2440 2441 return tb; 2442 } 2443 2444 #ifdef CONFIG_PROC_FS 2445 /* Depth first Trie walk iterator */ 2446 struct fib_trie_iter { 2447 struct seq_net_private p; 2448 struct fib_table *tb; 2449 struct key_vector *tnode; 2450 unsigned int index; 2451 unsigned int depth; 2452 }; 2453 2454 static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter) 2455 { 2456 unsigned long cindex = iter->index; 2457 struct key_vector *pn = iter->tnode; 2458 t_key pkey; 2459 2460 pr_debug("get_next iter={node=%p index=%d depth=%d}\n", 2461 iter->tnode, iter->index, iter->depth); 2462 2463 while (!IS_TRIE(pn)) { 2464 while (cindex < child_length(pn)) { 2465 struct key_vector *n = get_child_rcu(pn, cindex++); 2466 2467 if (!n) 2468 continue; 2469 2470 if (IS_LEAF(n)) { 2471 iter->tnode = pn; 2472 iter->index = cindex; 2473 } else { 2474 /* push down one level */ 2475 iter->tnode = n; 2476 iter->index = 0; 2477 ++iter->depth; 2478 } 2479 2480 return n; 2481 } 2482 2483 /* Current node exhausted, pop back up */ 2484 pkey = pn->key; 2485 pn = node_parent_rcu(pn); 2486 cindex = get_index(pkey, pn) + 1; 2487 --iter->depth; 2488 } 2489 2490 /* record root node so further searches know we are done */ 2491 iter->tnode = pn; 2492 iter->index = 0; 2493 2494 return NULL; 2495 } 2496 2497 static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter, 2498 struct trie *t) 2499 { 2500 struct key_vector *n, *pn; 2501 2502 if (!t) 2503 return NULL; 2504 2505 pn = t->kv; 2506 n = rcu_dereference(pn->tnode[0]); 2507 if (!n) 2508 return NULL; 2509 2510 if (IS_TNODE(n)) { 2511 iter->tnode = n; 2512 iter->index = 0; 2513 iter->depth = 1; 2514 } else { 2515 iter->tnode = pn; 2516 iter->index = 0; 2517 iter->depth = 0; 2518 } 2519 2520 return n; 2521 } 2522 2523 static void trie_collect_stats(struct trie *t, struct trie_stat *s) 2524 { 2525 struct key_vector *n; 2526 struct fib_trie_iter iter; 2527 2528 memset(s, 0, sizeof(*s)); 2529 2530 rcu_read_lock(); 2531 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) { 2532 if (IS_LEAF(n)) { 2533 struct fib_alias *fa; 2534 2535 s->leaves++; 2536 s->totdepth += iter.depth; 2537 if (iter.depth > s->maxdepth) 2538 s->maxdepth = iter.depth; 2539 2540 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) 2541 ++s->prefixes; 2542 } else { 2543 s->tnodes++; 2544 if (n->bits < MAX_STAT_DEPTH) 2545 s->nodesizes[n->bits]++; 2546 s->nullpointers += tn_info(n)->empty_children; 2547 } 2548 } 2549 rcu_read_unlock(); 2550 } 2551 2552 /* 2553 * This outputs /proc/net/fib_triestats 2554 */ 2555 static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat) 2556 { 2557 unsigned int i, max, pointers, bytes, avdepth; 2558 2559 if (stat->leaves) 2560 avdepth = stat->totdepth*100 / stat->leaves; 2561 else 2562 avdepth = 0; 2563 2564 seq_printf(seq, "\tAver depth: %u.%02d\n", 2565 avdepth / 100, avdepth % 100); 2566 seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth); 2567 2568 seq_printf(seq, "\tLeaves: %u\n", stat->leaves); 2569 bytes = LEAF_SIZE * stat->leaves; 2570 2571 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes); 2572 bytes += sizeof(struct fib_alias) * stat->prefixes; 2573 2574 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes); 2575 bytes += TNODE_SIZE(0) * stat->tnodes; 2576 2577 max = MAX_STAT_DEPTH; 2578 while (max > 0 && stat->nodesizes[max-1] == 0) 2579 max--; 2580 2581 pointers = 0; 2582 for (i = 1; i < max; i++) 2583 if (stat->nodesizes[i] != 0) { 2584 seq_printf(seq, " %u: %u", i, stat->nodesizes[i]); 2585 pointers += (1<<i) * stat->nodesizes[i]; 2586 } 2587 seq_putc(seq, '\n'); 2588 seq_printf(seq, "\tPointers: %u\n", pointers); 2589 2590 bytes += sizeof(struct key_vector *) * pointers; 2591 seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers); 2592 seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024); 2593 } 2594 2595 #ifdef CONFIG_IP_FIB_TRIE_STATS 2596 static void trie_show_usage(struct seq_file *seq, 2597 const struct trie_use_stats __percpu *stats) 2598 { 2599 struct trie_use_stats s = { 0 }; 2600 int cpu; 2601 2602 /* loop through all of the CPUs and gather up the stats */ 2603 for_each_possible_cpu(cpu) { 2604 const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu); 2605 2606 s.gets += pcpu->gets; 2607 s.backtrack += pcpu->backtrack; 2608 s.semantic_match_passed += pcpu->semantic_match_passed; 2609 s.semantic_match_miss += pcpu->semantic_match_miss; 2610 s.null_node_hit += pcpu->null_node_hit; 2611 s.resize_node_skipped += pcpu->resize_node_skipped; 2612 } 2613 2614 seq_printf(seq, "\nCounters:\n---------\n"); 2615 seq_printf(seq, "gets = %u\n", s.gets); 2616 seq_printf(seq, "backtracks = %u\n", s.backtrack); 2617 seq_printf(seq, "semantic match passed = %u\n", 2618 s.semantic_match_passed); 2619 seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss); 2620 seq_printf(seq, "null node hit= %u\n", s.null_node_hit); 2621 seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped); 2622 } 2623 #endif /* CONFIG_IP_FIB_TRIE_STATS */ 2624 2625 static void fib_table_print(struct seq_file *seq, struct fib_table *tb) 2626 { 2627 if (tb->tb_id == RT_TABLE_LOCAL) 2628 seq_puts(seq, "Local:\n"); 2629 else if (tb->tb_id == RT_TABLE_MAIN) 2630 seq_puts(seq, "Main:\n"); 2631 else 2632 seq_printf(seq, "Id %d:\n", tb->tb_id); 2633 } 2634 2635 2636 static int fib_triestat_seq_show(struct seq_file *seq, void *v) 2637 { 2638 struct net *net = seq->private; 2639 unsigned int h; 2640 2641 seq_printf(seq, 2642 "Basic info: size of leaf:" 2643 " %zd bytes, size of tnode: %zd bytes.\n", 2644 LEAF_SIZE, TNODE_SIZE(0)); 2645 2646 rcu_read_lock(); 2647 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2648 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2649 struct fib_table *tb; 2650 2651 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2652 struct trie *t = (struct trie *) tb->tb_data; 2653 struct trie_stat stat; 2654 2655 if (!t) 2656 continue; 2657 2658 fib_table_print(seq, tb); 2659 2660 trie_collect_stats(t, &stat); 2661 trie_show_stats(seq, &stat); 2662 #ifdef CONFIG_IP_FIB_TRIE_STATS 2663 trie_show_usage(seq, t->stats); 2664 #endif 2665 } 2666 cond_resched_rcu(); 2667 } 2668 rcu_read_unlock(); 2669 2670 return 0; 2671 } 2672 2673 static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos) 2674 { 2675 struct fib_trie_iter *iter = seq->private; 2676 struct net *net = seq_file_net(seq); 2677 loff_t idx = 0; 2678 unsigned int h; 2679 2680 for (h = 0; h < FIB_TABLE_HASHSZ; h++) { 2681 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2682 struct fib_table *tb; 2683 2684 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2685 struct key_vector *n; 2686 2687 for (n = fib_trie_get_first(iter, 2688 (struct trie *) tb->tb_data); 2689 n; n = fib_trie_get_next(iter)) 2690 if (pos == idx++) { 2691 iter->tb = tb; 2692 return n; 2693 } 2694 } 2695 } 2696 2697 return NULL; 2698 } 2699 2700 static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos) 2701 __acquires(RCU) 2702 { 2703 rcu_read_lock(); 2704 return fib_trie_get_idx(seq, *pos); 2705 } 2706 2707 static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2708 { 2709 struct fib_trie_iter *iter = seq->private; 2710 struct net *net = seq_file_net(seq); 2711 struct fib_table *tb = iter->tb; 2712 struct hlist_node *tb_node; 2713 unsigned int h; 2714 struct key_vector *n; 2715 2716 ++*pos; 2717 /* next node in same table */ 2718 n = fib_trie_get_next(iter); 2719 if (n) 2720 return n; 2721 2722 /* walk rest of this hash chain */ 2723 h = tb->tb_id & (FIB_TABLE_HASHSZ - 1); 2724 while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) { 2725 tb = hlist_entry(tb_node, struct fib_table, tb_hlist); 2726 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data); 2727 if (n) 2728 goto found; 2729 } 2730 2731 /* new hash chain */ 2732 while (++h < FIB_TABLE_HASHSZ) { 2733 struct hlist_head *head = &net->ipv4.fib_table_hash[h]; 2734 hlist_for_each_entry_rcu(tb, head, tb_hlist) { 2735 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data); 2736 if (n) 2737 goto found; 2738 } 2739 } 2740 return NULL; 2741 2742 found: 2743 iter->tb = tb; 2744 return n; 2745 } 2746 2747 static void fib_trie_seq_stop(struct seq_file *seq, void *v) 2748 __releases(RCU) 2749 { 2750 rcu_read_unlock(); 2751 } 2752 2753 static void seq_indent(struct seq_file *seq, int n) 2754 { 2755 while (n-- > 0) 2756 seq_puts(seq, " "); 2757 } 2758 2759 static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s) 2760 { 2761 switch (s) { 2762 case RT_SCOPE_UNIVERSE: return "universe"; 2763 case RT_SCOPE_SITE: return "site"; 2764 case RT_SCOPE_LINK: return "link"; 2765 case RT_SCOPE_HOST: return "host"; 2766 case RT_SCOPE_NOWHERE: return "nowhere"; 2767 default: 2768 snprintf(buf, len, "scope=%d", s); 2769 return buf; 2770 } 2771 } 2772 2773 static const char *const rtn_type_names[__RTN_MAX] = { 2774 [RTN_UNSPEC] = "UNSPEC", 2775 [RTN_UNICAST] = "UNICAST", 2776 [RTN_LOCAL] = "LOCAL", 2777 [RTN_BROADCAST] = "BROADCAST", 2778 [RTN_ANYCAST] = "ANYCAST", 2779 [RTN_MULTICAST] = "MULTICAST", 2780 [RTN_BLACKHOLE] = "BLACKHOLE", 2781 [RTN_UNREACHABLE] = "UNREACHABLE", 2782 [RTN_PROHIBIT] = "PROHIBIT", 2783 [RTN_THROW] = "THROW", 2784 [RTN_NAT] = "NAT", 2785 [RTN_XRESOLVE] = "XRESOLVE", 2786 }; 2787 2788 static inline const char *rtn_type(char *buf, size_t len, unsigned int t) 2789 { 2790 if (t < __RTN_MAX && rtn_type_names[t]) 2791 return rtn_type_names[t]; 2792 snprintf(buf, len, "type %u", t); 2793 return buf; 2794 } 2795 2796 /* Pretty print the trie */ 2797 static int fib_trie_seq_show(struct seq_file *seq, void *v) 2798 { 2799 const struct fib_trie_iter *iter = seq->private; 2800 struct key_vector *n = v; 2801 2802 if (IS_TRIE(node_parent_rcu(n))) 2803 fib_table_print(seq, iter->tb); 2804 2805 if (IS_TNODE(n)) { 2806 __be32 prf = htonl(n->key); 2807 2808 seq_indent(seq, iter->depth-1); 2809 seq_printf(seq, " +-- %pI4/%zu %u %u %u\n", 2810 &prf, KEYLENGTH - n->pos - n->bits, n->bits, 2811 tn_info(n)->full_children, 2812 tn_info(n)->empty_children); 2813 } else { 2814 __be32 val = htonl(n->key); 2815 struct fib_alias *fa; 2816 2817 seq_indent(seq, iter->depth); 2818 seq_printf(seq, " |-- %pI4\n", &val); 2819 2820 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) { 2821 char buf1[32], buf2[32]; 2822 2823 seq_indent(seq, iter->depth + 1); 2824 seq_printf(seq, " /%zu %s %s", 2825 KEYLENGTH - fa->fa_slen, 2826 rtn_scope(buf1, sizeof(buf1), 2827 fa->fa_info->fib_scope), 2828 rtn_type(buf2, sizeof(buf2), 2829 fa->fa_type)); 2830 if (fa->fa_dscp) 2831 seq_printf(seq, " tos=%d", 2832 inet_dscp_to_dsfield(fa->fa_dscp)); 2833 seq_putc(seq, '\n'); 2834 } 2835 } 2836 2837 return 0; 2838 } 2839 2840 static const struct seq_operations fib_trie_seq_ops = { 2841 .start = fib_trie_seq_start, 2842 .next = fib_trie_seq_next, 2843 .stop = fib_trie_seq_stop, 2844 .show = fib_trie_seq_show, 2845 }; 2846 2847 struct fib_route_iter { 2848 struct seq_net_private p; 2849 struct fib_table *main_tb; 2850 struct key_vector *tnode; 2851 loff_t pos; 2852 t_key key; 2853 }; 2854 2855 static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter, 2856 loff_t pos) 2857 { 2858 struct key_vector *l, **tp = &iter->tnode; 2859 t_key key; 2860 2861 /* use cached location of previously found key */ 2862 if (iter->pos > 0 && pos >= iter->pos) { 2863 key = iter->key; 2864 } else { 2865 iter->pos = 1; 2866 key = 0; 2867 } 2868 2869 pos -= iter->pos; 2870 2871 while ((l = leaf_walk_rcu(tp, key)) && (pos-- > 0)) { 2872 key = l->key + 1; 2873 iter->pos++; 2874 l = NULL; 2875 2876 /* handle unlikely case of a key wrap */ 2877 if (!key) 2878 break; 2879 } 2880 2881 if (l) 2882 iter->key = l->key; /* remember it */ 2883 else 2884 iter->pos = 0; /* forget it */ 2885 2886 return l; 2887 } 2888 2889 static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos) 2890 __acquires(RCU) 2891 { 2892 struct fib_route_iter *iter = seq->private; 2893 struct fib_table *tb; 2894 struct trie *t; 2895 2896 rcu_read_lock(); 2897 2898 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN); 2899 if (!tb) 2900 return NULL; 2901 2902 iter->main_tb = tb; 2903 t = (struct trie *)tb->tb_data; 2904 iter->tnode = t->kv; 2905 2906 if (*pos != 0) 2907 return fib_route_get_idx(iter, *pos); 2908 2909 iter->pos = 0; 2910 iter->key = KEY_MAX; 2911 2912 return SEQ_START_TOKEN; 2913 } 2914 2915 static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos) 2916 { 2917 struct fib_route_iter *iter = seq->private; 2918 struct key_vector *l = NULL; 2919 t_key key = iter->key + 1; 2920 2921 ++*pos; 2922 2923 /* only allow key of 0 for start of sequence */ 2924 if ((v == SEQ_START_TOKEN) || key) 2925 l = leaf_walk_rcu(&iter->tnode, key); 2926 2927 if (l) { 2928 iter->key = l->key; 2929 iter->pos++; 2930 } else { 2931 iter->pos = 0; 2932 } 2933 2934 return l; 2935 } 2936 2937 static void fib_route_seq_stop(struct seq_file *seq, void *v) 2938 __releases(RCU) 2939 { 2940 rcu_read_unlock(); 2941 } 2942 2943 static unsigned int fib_flag_trans(int type, __be32 mask, struct fib_info *fi) 2944 { 2945 unsigned int flags = 0; 2946 2947 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT) 2948 flags = RTF_REJECT; 2949 if (fi) { 2950 const struct fib_nh_common *nhc = fib_info_nhc(fi, 0); 2951 2952 if (nhc->nhc_gw.ipv4) 2953 flags |= RTF_GATEWAY; 2954 } 2955 if (mask == htonl(0xFFFFFFFF)) 2956 flags |= RTF_HOST; 2957 flags |= RTF_UP; 2958 return flags; 2959 } 2960 2961 /* 2962 * This outputs /proc/net/route. 2963 * The format of the file is not supposed to be changed 2964 * and needs to be same as fib_hash output to avoid breaking 2965 * legacy utilities 2966 */ 2967 static int fib_route_seq_show(struct seq_file *seq, void *v) 2968 { 2969 struct fib_route_iter *iter = seq->private; 2970 struct fib_table *tb = iter->main_tb; 2971 struct fib_alias *fa; 2972 struct key_vector *l = v; 2973 __be32 prefix; 2974 2975 if (v == SEQ_START_TOKEN) { 2976 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway " 2977 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU" 2978 "\tWindow\tIRTT"); 2979 return 0; 2980 } 2981 2982 prefix = htonl(l->key); 2983 2984 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) { 2985 struct fib_info *fi = fa->fa_info; 2986 __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen); 2987 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi); 2988 2989 if ((fa->fa_type == RTN_BROADCAST) || 2990 (fa->fa_type == RTN_MULTICAST)) 2991 continue; 2992 2993 if (fa->tb_id != tb->tb_id) 2994 continue; 2995 2996 seq_setwidth(seq, 127); 2997 2998 if (fi) { 2999 struct fib_nh_common *nhc = fib_info_nhc(fi, 0); 3000 __be32 gw = 0; 3001 3002 if (nhc->nhc_gw_family == AF_INET) 3003 gw = nhc->nhc_gw.ipv4; 3004 3005 seq_printf(seq, 3006 "%s\t%08X\t%08X\t%04X\t%d\t%u\t" 3007 "%d\t%08X\t%d\t%u\t%u", 3008 nhc->nhc_dev ? nhc->nhc_dev->name : "*", 3009 prefix, gw, flags, 0, 0, 3010 fi->fib_priority, 3011 mask, 3012 (fi->fib_advmss ? 3013 fi->fib_advmss + 40 : 0), 3014 fi->fib_window, 3015 fi->fib_rtt >> 3); 3016 } else { 3017 seq_printf(seq, 3018 "*\t%08X\t%08X\t%04X\t%d\t%u\t" 3019 "%d\t%08X\t%d\t%u\t%u", 3020 prefix, 0, flags, 0, 0, 0, 3021 mask, 0, 0, 0); 3022 } 3023 seq_pad(seq, '\n'); 3024 } 3025 3026 return 0; 3027 } 3028 3029 static const struct seq_operations fib_route_seq_ops = { 3030 .start = fib_route_seq_start, 3031 .next = fib_route_seq_next, 3032 .stop = fib_route_seq_stop, 3033 .show = fib_route_seq_show, 3034 }; 3035 3036 int __net_init fib_proc_init(struct net *net) 3037 { 3038 if (!proc_create_net("fib_trie", 0444, net->proc_net, &fib_trie_seq_ops, 3039 sizeof(struct fib_trie_iter))) 3040 goto out1; 3041 3042 if (!proc_create_net_single("fib_triestat", 0444, net->proc_net, 3043 fib_triestat_seq_show, NULL)) 3044 goto out2; 3045 3046 if (!proc_create_net("route", 0444, net->proc_net, &fib_route_seq_ops, 3047 sizeof(struct fib_route_iter))) 3048 goto out3; 3049 3050 return 0; 3051 3052 out3: 3053 remove_proc_entry("fib_triestat", net->proc_net); 3054 out2: 3055 remove_proc_entry("fib_trie", net->proc_net); 3056 out1: 3057 return -ENOMEM; 3058 } 3059 3060 void __net_exit fib_proc_exit(struct net *net) 3061 { 3062 remove_proc_entry("fib_trie", net->proc_net); 3063 remove_proc_entry("fib_triestat", net->proc_net); 3064 remove_proc_entry("route", net->proc_net); 3065 } 3066 3067 #endif /* CONFIG_PROC_FS */ 3068