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.
7 * Robert Olsson <robert.olsson@its.uu.se> Uppsala Universitet
8 * & Swedish University of Agricultural Sciences.
10 * Jens Laas <jens.laas@data.slu.se> Swedish University of
11 * Agricultural Sciences.
13 * Hans Liss <hans.liss@its.uu.se> Uppsala Universitet
15 * This work is based on the LPC-trie which is originally described in:
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/
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
26 * Code from fib_hash has been reused which includes the following header:
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.
33 * IPv4 FIB: lookup engine and maintenance routines.
36 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
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.
43 * Substantial contributions to this work comes from:
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>
51 #define VERSION "0.409"
53 #include <asm/uaccess.h>
54 #include <linux/bitops.h>
55 #include <linux/types.h>
56 #include <linux/kernel.h>
58 #include <linux/string.h>
59 #include <linux/socket.h>
60 #include <linux/sockios.h>
61 #include <linux/errno.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 <net/net_namespace.h>
77 #include <net/protocol.h>
78 #include <net/route.h>
81 #include <net/ip_fib.h>
82 #include "fib_lookup.h"
84 #define MAX_STAT_DEPTH 32
86 #define KEYLENGTH (8*sizeof(t_key))
88 typedef unsigned int t_key;
90 #define IS_TNODE(n) ((n)->bits)
91 #define IS_LEAF(n) (!(n)->bits)
93 #define get_index(_key, _kv) (((_key) ^ (_kv)->key) >> (_kv)->pos)
97 unsigned char bits; /* 2log(KEYLENGTH) bits needed */
98 unsigned char pos; /* 2log(KEYLENGTH) bits needed */
99 struct tnode __rcu *parent;
102 /* The fields in this struct are valid if bits > 0 (TNODE) */
104 unsigned int full_children; /* KEYLENGTH bits needed */
105 unsigned int empty_children; /* KEYLENGTH bits needed */
106 struct tnode __rcu *child[0];
108 /* This list pointer if valid if bits == 0 (LEAF) */
109 struct hlist_head list;
114 struct hlist_node hlist;
116 u32 mask_plen; /* ntohl(inet_make_mask(plen)) */
117 struct list_head falh;
121 #ifdef CONFIG_IP_FIB_TRIE_STATS
122 struct trie_use_stats {
124 unsigned int backtrack;
125 unsigned int semantic_match_passed;
126 unsigned int semantic_match_miss;
127 unsigned int null_node_hit;
128 unsigned int resize_node_skipped;
133 unsigned int totdepth;
134 unsigned int maxdepth;
137 unsigned int nullpointers;
138 unsigned int prefixes;
139 unsigned int nodesizes[MAX_STAT_DEPTH];
143 struct tnode __rcu *trie;
144 #ifdef CONFIG_IP_FIB_TRIE_STATS
145 struct trie_use_stats __percpu *stats;
149 static void tnode_put_child_reorg(struct tnode *tn, unsigned long i,
150 struct tnode *n, int wasfull);
151 static struct tnode *resize(struct trie *t, struct tnode *tn);
152 /* tnodes to free after resize(); protected by RTNL */
153 static struct callback_head *tnode_free_head;
154 static size_t tnode_free_size;
157 * synchronize_rcu after call_rcu for that many pages; it should be especially
158 * useful before resizing the root node with PREEMPT_NONE configs; the value was
159 * obtained experimentally, aiming to avoid visible slowdown.
161 static const int sync_pages = 128;
163 static struct kmem_cache *fn_alias_kmem __read_mostly;
164 static struct kmem_cache *trie_leaf_kmem __read_mostly;
166 /* caller must hold RTNL */
167 #define node_parent(n) rtnl_dereference((n)->parent)
169 /* caller must hold RCU read lock or RTNL */
170 #define node_parent_rcu(n) rcu_dereference_rtnl((n)->parent)
172 /* wrapper for rcu_assign_pointer */
173 static inline void node_set_parent(struct tnode *n, struct tnode *tp)
176 rcu_assign_pointer(n->parent, tp);
179 #define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER((n)->parent, p)
181 /* This provides us with the number of children in this node, in the case of a
182 * leaf this will return 0 meaning none of the children are accessible.
184 static inline unsigned long tnode_child_length(const struct tnode *tn)
186 return (1ul << tn->bits) & ~(1ul);
189 /* caller must hold RTNL */
190 static inline struct tnode *tnode_get_child(const struct tnode *tn,
193 BUG_ON(i >= tnode_child_length(tn));
195 return rtnl_dereference(tn->child[i]);
198 /* caller must hold RCU read lock or RTNL */
199 static inline struct tnode *tnode_get_child_rcu(const struct tnode *tn,
202 BUG_ON(i >= tnode_child_length(tn));
204 return rcu_dereference_rtnl(tn->child[i]);
207 /* To understand this stuff, an understanding of keys and all their bits is
208 * necessary. Every node in the trie has a key associated with it, but not
209 * all of the bits in that key are significant.
211 * Consider a node 'n' and its parent 'tp'.
213 * If n is a leaf, every bit in its key is significant. Its presence is
214 * necessitated by path compression, since during a tree traversal (when
215 * searching for a leaf - unless we are doing an insertion) we will completely
216 * ignore all skipped bits we encounter. Thus we need to verify, at the end of
217 * a potentially successful search, that we have indeed been walking the
220 * Note that we can never "miss" the correct key in the tree if present by
221 * following the wrong path. Path compression ensures that segments of the key
222 * that are the same for all keys with a given prefix are skipped, but the
223 * skipped part *is* identical for each node in the subtrie below the skipped
224 * bit! trie_insert() in this implementation takes care of that.
226 * if n is an internal node - a 'tnode' here, the various parts of its key
227 * have many different meanings.
230 * _________________________________________________________________
231 * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
232 * -----------------------------------------------------------------
233 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
235 * _________________________________________________________________
236 * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
237 * -----------------------------------------------------------------
238 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
245 * First, let's just ignore the bits that come before the parent tp, that is
246 * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this
247 * point we do not use them for anything.
249 * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the
250 * index into the parent's child array. That is, they will be used to find
251 * 'n' among tp's children.
253 * The bits from (n->pos + n->bits) to (tn->pos - 1) - "S" - are skipped bits
256 * All the bits we have seen so far are significant to the node n. The rest
257 * of the bits are really not needed or indeed known in n->key.
259 * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into
260 * n's child array, and will of course be different for each child.
262 * The rest of the bits, from 0 to (n->pos + n->bits), are completely unknown
266 static const int halve_threshold = 25;
267 static const int inflate_threshold = 50;
268 static const int halve_threshold_root = 15;
269 static const int inflate_threshold_root = 30;
271 static void __alias_free_mem(struct rcu_head *head)
273 struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
274 kmem_cache_free(fn_alias_kmem, fa);
277 static inline void alias_free_mem_rcu(struct fib_alias *fa)
279 call_rcu(&fa->rcu, __alias_free_mem);
282 #define TNODE_KMALLOC_MAX \
283 ilog2((PAGE_SIZE - sizeof(struct tnode)) / sizeof(struct tnode *))
285 static void __node_free_rcu(struct rcu_head *head)
287 struct tnode *n = container_of(head, struct tnode, rcu);
290 kmem_cache_free(trie_leaf_kmem, n);
291 else if (n->bits <= TNODE_KMALLOC_MAX)
297 #define node_free(n) call_rcu(&n->rcu, __node_free_rcu)
299 static inline void free_leaf_info(struct leaf_info *leaf)
301 kfree_rcu(leaf, rcu);
304 static struct tnode *tnode_alloc(size_t size)
306 if (size <= PAGE_SIZE)
307 return kzalloc(size, GFP_KERNEL);
309 return vzalloc(size);
312 static void tnode_free_safe(struct tnode *tn)
315 tn->rcu.next = tnode_free_head;
316 tnode_free_head = &tn->rcu;
319 static void tnode_free_flush(void)
321 struct callback_head *head;
323 while ((head = tnode_free_head)) {
324 struct tnode *tn = container_of(head, struct tnode, rcu);
326 tnode_free_head = head->next;
327 tnode_free_size += offsetof(struct tnode, child[1 << tn->bits]);
332 if (tnode_free_size >= PAGE_SIZE * sync_pages) {
338 static struct tnode *leaf_new(t_key key)
340 struct tnode *l = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
343 /* set key and pos to reflect full key value
344 * any trailing zeros in the key should be ignored
345 * as the nodes are searched
349 /* set bits to 0 indicating we are not a tnode */
352 INIT_HLIST_HEAD(&l->list);
357 static struct leaf_info *leaf_info_new(int plen)
359 struct leaf_info *li = kmalloc(sizeof(struct leaf_info), GFP_KERNEL);
362 li->mask_plen = ntohl(inet_make_mask(plen));
363 INIT_LIST_HEAD(&li->falh);
368 static struct tnode *tnode_new(t_key key, int pos, int bits)
370 size_t sz = offsetof(struct tnode, child[1 << bits]);
371 struct tnode *tn = tnode_alloc(sz);
372 unsigned int shift = pos + bits;
374 /* verify bits and pos their msb bits clear and values are valid */
375 BUG_ON(!bits || (shift > KEYLENGTH));
381 tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
382 tn->full_children = 0;
383 tn->empty_children = 1<<bits;
386 pr_debug("AT %p s=%zu %zu\n", tn, sizeof(struct tnode),
387 sizeof(struct tnode *) << bits);
391 /* Check whether a tnode 'n' is "full", i.e. it is an internal node
392 * and no bits are skipped. See discussion in dyntree paper p. 6
394 static inline int tnode_full(const struct tnode *tn, const struct tnode *n)
396 return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n);
399 static inline void put_child(struct tnode *tn, unsigned long i,
402 tnode_put_child_reorg(tn, i, n, -1);
406 * Add a child at position i overwriting the old value.
407 * Update the value of full_children and empty_children.
410 static void tnode_put_child_reorg(struct tnode *tn, unsigned long i,
411 struct tnode *n, int wasfull)
413 struct tnode *chi = rtnl_dereference(tn->child[i]);
416 BUG_ON(i >= tnode_child_length(tn));
418 /* update emptyChildren */
419 if (n == NULL && chi != NULL)
420 tn->empty_children++;
421 else if (n != NULL && chi == NULL)
422 tn->empty_children--;
424 /* update fullChildren */
426 wasfull = tnode_full(tn, chi);
428 isfull = tnode_full(tn, n);
429 if (wasfull && !isfull)
431 else if (!wasfull && isfull)
434 node_set_parent(n, tn);
436 rcu_assign_pointer(tn->child[i], n);
439 static void put_child_root(struct tnode *tp, struct trie *t,
440 t_key key, struct tnode *n)
443 put_child(tp, get_index(key, tp), n);
445 rcu_assign_pointer(t->trie, n);
448 static void tnode_clean_free(struct tnode *tn)
450 struct tnode *tofree;
453 for (i = 0; i < tnode_child_length(tn); i++) {
454 tofree = tnode_get_child(tn, i);
461 static struct tnode *inflate(struct trie *t, struct tnode *oldtnode)
463 unsigned long olen = tnode_child_length(oldtnode);
468 pr_debug("In inflate\n");
470 tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1);
473 return ERR_PTR(-ENOMEM);
476 * Preallocate and store tnodes before the actual work so we
477 * don't get into an inconsistent state if memory allocation
478 * fails. In case of failure we return the oldnode and inflate
479 * of tnode is ignored.
481 for (i = 0, m = 1u << tn->pos; i < olen; i++) {
482 struct tnode *inode = tnode_get_child(oldtnode, i);
484 if (tnode_full(oldtnode, inode) && (inode->bits > 1)) {
485 struct tnode *left, *right;
487 left = tnode_new(inode->key & ~m, inode->pos,
492 right = tnode_new(inode->key | m, inode->pos,
500 put_child(tn, 2*i, left);
501 put_child(tn, 2*i+1, right);
505 for (i = 0; i < olen; i++) {
506 struct tnode *inode = tnode_get_child(oldtnode, i);
507 struct tnode *left, *right;
508 unsigned long size, j;
514 /* A leaf or an internal node with skipped bits */
515 if (!tnode_full(oldtnode, inode)) {
516 put_child(tn, get_index(inode->key, tn), inode);
520 /* An internal node with two children */
521 if (inode->bits == 1) {
522 put_child(tn, 2*i, rtnl_dereference(inode->child[0]));
523 put_child(tn, 2*i+1, rtnl_dereference(inode->child[1]));
525 tnode_free_safe(inode);
529 /* An internal node with more than two children */
531 /* We will replace this node 'inode' with two new
532 * ones, 'left' and 'right', each with half of the
533 * original children. The two new nodes will have
534 * a position one bit further down the key and this
535 * means that the "significant" part of their keys
536 * (see the discussion near the top of this file)
537 * will differ by one bit, which will be "0" in
538 * left's key and "1" in right's key. Since we are
539 * moving the key position by one step, the bit that
540 * we are moving away from - the bit at position
541 * (inode->pos) - is the one that will differ between
542 * left and right. So... we synthesize that bit in the
544 * The mask 'm' below will be a single "one" bit at
545 * the position (inode->pos)
548 /* Use the old key, but set the new significant
552 left = tnode_get_child(tn, 2*i);
553 put_child(tn, 2*i, NULL);
557 right = tnode_get_child(tn, 2*i+1);
558 put_child(tn, 2*i+1, NULL);
562 size = tnode_child_length(left);
563 for (j = 0; j < size; j++) {
564 put_child(left, j, rtnl_dereference(inode->child[j]));
565 put_child(right, j, rtnl_dereference(inode->child[j + size]));
567 put_child(tn, 2*i, resize(t, left));
568 put_child(tn, 2*i+1, resize(t, right));
570 tnode_free_safe(inode);
572 tnode_free_safe(oldtnode);
575 tnode_clean_free(tn);
576 return ERR_PTR(-ENOMEM);
579 static struct tnode *halve(struct trie *t, struct tnode *oldtnode)
581 unsigned long olen = tnode_child_length(oldtnode);
582 struct tnode *tn, *left, *right;
585 pr_debug("In halve\n");
587 tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1);
590 return ERR_PTR(-ENOMEM);
593 * Preallocate and store tnodes before the actual work so we
594 * don't get into an inconsistent state if memory allocation
595 * fails. In case of failure we return the oldnode and halve
596 * of tnode is ignored.
599 for (i = 0; i < olen; i += 2) {
600 left = tnode_get_child(oldtnode, i);
601 right = tnode_get_child(oldtnode, i+1);
603 /* Two nonempty children */
607 newn = tnode_new(left->key, oldtnode->pos, 1);
612 put_child(tn, i/2, newn);
617 for (i = 0; i < olen; i += 2) {
618 struct tnode *newBinNode;
620 left = tnode_get_child(oldtnode, i);
621 right = tnode_get_child(oldtnode, i+1);
623 /* At least one of the children is empty */
625 if (right == NULL) /* Both are empty */
627 put_child(tn, i/2, right);
632 put_child(tn, i/2, left);
636 /* Two nonempty children */
637 newBinNode = tnode_get_child(tn, i/2);
638 put_child(tn, i/2, NULL);
639 put_child(newBinNode, 0, left);
640 put_child(newBinNode, 1, right);
641 put_child(tn, i/2, resize(t, newBinNode));
643 tnode_free_safe(oldtnode);
646 tnode_clean_free(tn);
647 return ERR_PTR(-ENOMEM);
651 static struct tnode *resize(struct trie *t, struct tnode *tn)
653 struct tnode *old_tn, *n = NULL;
654 int inflate_threshold_use;
655 int halve_threshold_use;
661 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
662 tn, inflate_threshold, halve_threshold);
665 if (tn->empty_children > (tnode_child_length(tn) - 1))
669 if (tn->empty_children == (tnode_child_length(tn) - 1))
672 * Double as long as the resulting node has a number of
673 * nonempty nodes that are above the threshold.
677 * From "Implementing a dynamic compressed trie" by Stefan Nilsson of
678 * the Helsinki University of Technology and Matti Tikkanen of Nokia
679 * Telecommunications, page 6:
680 * "A node is doubled if the ratio of non-empty children to all
681 * children in the *doubled* node is at least 'high'."
683 * 'high' in this instance is the variable 'inflate_threshold'. It
684 * is expressed as a percentage, so we multiply it with
685 * tnode_child_length() and instead of multiplying by 2 (since the
686 * child array will be doubled by inflate()) and multiplying
687 * the left-hand side by 100 (to handle the percentage thing) we
688 * multiply the left-hand side by 50.
690 * The left-hand side may look a bit weird: tnode_child_length(tn)
691 * - tn->empty_children is of course the number of non-null children
692 * in the current node. tn->full_children is the number of "full"
693 * children, that is non-null tnodes with a skip value of 0.
694 * All of those will be doubled in the resulting inflated tnode, so
695 * we just count them one extra time here.
697 * A clearer way to write this would be:
699 * to_be_doubled = tn->full_children;
700 * not_to_be_doubled = tnode_child_length(tn) - tn->empty_children -
703 * new_child_length = tnode_child_length(tn) * 2;
705 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
707 * if (new_fill_factor >= inflate_threshold)
709 * ...and so on, tho it would mess up the while () loop.
712 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
716 * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
717 * inflate_threshold * new_child_length
719 * expand not_to_be_doubled and to_be_doubled, and shorten:
720 * 100 * (tnode_child_length(tn) - tn->empty_children +
721 * tn->full_children) >= inflate_threshold * new_child_length
723 * expand new_child_length:
724 * 100 * (tnode_child_length(tn) - tn->empty_children +
725 * tn->full_children) >=
726 * inflate_threshold * tnode_child_length(tn) * 2
729 * 50 * (tn->full_children + tnode_child_length(tn) -
730 * tn->empty_children) >= inflate_threshold *
731 * tnode_child_length(tn)
735 /* Keep root node larger */
737 if (!node_parent(tn)) {
738 inflate_threshold_use = inflate_threshold_root;
739 halve_threshold_use = halve_threshold_root;
741 inflate_threshold_use = inflate_threshold;
742 halve_threshold_use = halve_threshold;
746 while ((tn->full_children > 0 && max_work-- &&
747 50 * (tn->full_children + tnode_child_length(tn)
748 - tn->empty_children)
749 >= inflate_threshold_use * tnode_child_length(tn))) {
756 #ifdef CONFIG_IP_FIB_TRIE_STATS
757 this_cpu_inc(t->stats->resize_node_skipped);
763 /* Return if at least one inflate is run */
764 if (max_work != MAX_WORK)
768 * Halve as long as the number of empty children in this
769 * node is above threshold.
773 while (tn->bits > 1 && max_work-- &&
774 100 * (tnode_child_length(tn) - tn->empty_children) <
775 halve_threshold_use * tnode_child_length(tn)) {
781 #ifdef CONFIG_IP_FIB_TRIE_STATS
782 this_cpu_inc(t->stats->resize_node_skipped);
789 /* Only one child remains */
790 if (tn->empty_children == (tnode_child_length(tn) - 1)) {
793 for (i = tnode_child_length(tn); !n && i;)
794 n = tnode_get_child(tn, --i);
796 /* compress one level */
797 node_set_parent(n, NULL);
804 /* readside must use rcu_read_lock currently dump routines
805 via get_fa_head and dump */
807 static struct leaf_info *find_leaf_info(struct tnode *l, int plen)
809 struct hlist_head *head = &l->list;
810 struct leaf_info *li;
812 hlist_for_each_entry_rcu(li, head, hlist)
813 if (li->plen == plen)
819 static inline struct list_head *get_fa_head(struct tnode *l, int plen)
821 struct leaf_info *li = find_leaf_info(l, plen);
829 static void insert_leaf_info(struct hlist_head *head, struct leaf_info *new)
831 struct leaf_info *li = NULL, *last = NULL;
833 if (hlist_empty(head)) {
834 hlist_add_head_rcu(&new->hlist, head);
836 hlist_for_each_entry(li, head, hlist) {
837 if (new->plen > li->plen)
843 hlist_add_behind_rcu(&new->hlist, &last->hlist);
845 hlist_add_before_rcu(&new->hlist, &li->hlist);
849 /* rcu_read_lock needs to be hold by caller from readside */
850 static struct tnode *fib_find_node(struct trie *t, u32 key)
852 struct tnode *n = rcu_dereference_rtnl(t->trie);
855 unsigned long index = get_index(key, n);
857 /* This bit of code is a bit tricky but it combines multiple
858 * checks into a single check. The prefix consists of the
859 * prefix plus zeros for the bits in the cindex. The index
860 * is the difference between the key and this value. From
861 * this we can actually derive several pieces of data.
862 * if !(index >> bits)
863 * we know the value is cindex
865 * we have a mismatch in skip bits and failed
867 if (index >> n->bits)
870 /* we have found a leaf. Prefixes have already been compared */
874 n = rcu_dereference_rtnl(n->child[index]);
880 static void trie_rebalance(struct trie *t, struct tnode *tn)
888 while (tn != NULL && (tp = node_parent(tn)) != NULL) {
889 cindex = get_index(key, tp);
890 wasfull = tnode_full(tp, tnode_get_child(tp, cindex));
893 tnode_put_child_reorg(tp, cindex, tn, wasfull);
895 tp = node_parent(tn);
897 rcu_assign_pointer(t->trie, tn);
905 /* Handle last (top) tnode */
909 rcu_assign_pointer(t->trie, tn);
913 /* only used from updater-side */
915 static struct list_head *fib_insert_node(struct trie *t, u32 key, int plen)
917 struct list_head *fa_head = NULL;
918 struct tnode *l, *n, *tp = NULL;
919 struct leaf_info *li;
921 li = leaf_info_new(plen);
926 n = rtnl_dereference(t->trie);
928 /* If we point to NULL, stop. Either the tree is empty and we should
929 * just put a new leaf in if, or we have reached an empty child slot,
930 * and we should just put our new leaf in that.
932 * If we hit a node with a key that does't match then we should stop
933 * and create a new tnode to replace that node and insert ourselves
934 * and the other node into the new tnode.
937 unsigned long index = get_index(key, n);
939 /* This bit of code is a bit tricky but it combines multiple
940 * checks into a single check. The prefix consists of the
941 * prefix plus zeros for the "bits" in the prefix. The index
942 * is the difference between the key and this value. From
943 * this we can actually derive several pieces of data.
944 * if !(index >> bits)
945 * we know the value is child index
947 * we have a mismatch in skip bits and failed
949 if (index >> n->bits)
952 /* we have found a leaf. Prefixes have already been compared */
954 /* Case 1: n is a leaf, and prefixes match*/
955 insert_leaf_info(&n->list, li);
960 n = rcu_dereference_rtnl(n->child[index]);
969 insert_leaf_info(&l->list, li);
971 /* Case 2: n is a LEAF or a TNODE and the key doesn't match.
973 * Add a new tnode here
974 * first tnode need some special handling
975 * leaves us in position for handling as case 3
980 tn = tnode_new(key, __fls(key ^ n->key), 1);
987 /* initialize routes out of node */
988 NODE_INIT_PARENT(tn, tp);
989 put_child(tn, get_index(key, tn) ^ 1, n);
991 /* start adding routes into the node */
992 put_child_root(tp, t, key, tn);
993 node_set_parent(n, tn);
995 /* parent now has a NULL spot where the leaf can go */
999 /* Case 3: n is NULL, and will just insert a new leaf */
1001 NODE_INIT_PARENT(l, tp);
1002 put_child(tp, get_index(key, tp), l);
1003 trie_rebalance(t, tp);
1005 rcu_assign_pointer(t->trie, l);
1012 * Caller must hold RTNL.
1014 int fib_table_insert(struct fib_table *tb, struct fib_config *cfg)
1016 struct trie *t = (struct trie *) tb->tb_data;
1017 struct fib_alias *fa, *new_fa;
1018 struct list_head *fa_head = NULL;
1019 struct fib_info *fi;
1020 int plen = cfg->fc_dst_len;
1021 u8 tos = cfg->fc_tos;
1029 key = ntohl(cfg->fc_dst);
1031 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
1033 mask = ntohl(inet_make_mask(plen));
1040 fi = fib_create_info(cfg);
1046 l = fib_find_node(t, key);
1050 fa_head = get_fa_head(l, plen);
1051 fa = fib_find_alias(fa_head, tos, fi->fib_priority);
1054 /* Now fa, if non-NULL, points to the first fib alias
1055 * with the same keys [prefix,tos,priority], if such key already
1056 * exists or to the node before which we will insert new one.
1058 * If fa is NULL, we will need to allocate a new one and
1059 * insert to the head of f.
1061 * If f is NULL, no fib node matched the destination key
1062 * and we need to allocate a new one of those as well.
1065 if (fa && fa->fa_tos == tos &&
1066 fa->fa_info->fib_priority == fi->fib_priority) {
1067 struct fib_alias *fa_first, *fa_match;
1070 if (cfg->fc_nlflags & NLM_F_EXCL)
1074 * 1. Find exact match for type, scope, fib_info to avoid
1076 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
1080 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
1081 list_for_each_entry_continue(fa, fa_head, fa_list) {
1082 if (fa->fa_tos != tos)
1084 if (fa->fa_info->fib_priority != fi->fib_priority)
1086 if (fa->fa_type == cfg->fc_type &&
1087 fa->fa_info == fi) {
1093 if (cfg->fc_nlflags & NLM_F_REPLACE) {
1094 struct fib_info *fi_drop;
1104 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1108 fi_drop = fa->fa_info;
1109 new_fa->fa_tos = fa->fa_tos;
1110 new_fa->fa_info = fi;
1111 new_fa->fa_type = cfg->fc_type;
1112 state = fa->fa_state;
1113 new_fa->fa_state = state & ~FA_S_ACCESSED;
1115 list_replace_rcu(&fa->fa_list, &new_fa->fa_list);
1116 alias_free_mem_rcu(fa);
1118 fib_release_info(fi_drop);
1119 if (state & FA_S_ACCESSED)
1120 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1121 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
1122 tb->tb_id, &cfg->fc_nlinfo, NLM_F_REPLACE);
1126 /* Error if we find a perfect match which
1127 * uses the same scope, type, and nexthop
1133 if (!(cfg->fc_nlflags & NLM_F_APPEND))
1137 if (!(cfg->fc_nlflags & NLM_F_CREATE))
1141 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1145 new_fa->fa_info = fi;
1146 new_fa->fa_tos = tos;
1147 new_fa->fa_type = cfg->fc_type;
1148 new_fa->fa_state = 0;
1150 * Insert new entry to the list.
1154 fa_head = fib_insert_node(t, key, plen);
1155 if (unlikely(!fa_head)) {
1157 goto out_free_new_fa;
1162 tb->tb_num_default++;
1164 list_add_tail_rcu(&new_fa->fa_list,
1165 (fa ? &fa->fa_list : fa_head));
1167 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1168 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, tb->tb_id,
1169 &cfg->fc_nlinfo, 0);
1174 kmem_cache_free(fn_alias_kmem, new_fa);
1176 fib_release_info(fi);
1181 static inline t_key prefix_mismatch(t_key key, struct tnode *n)
1183 t_key prefix = n->key;
1185 return (key ^ prefix) & (prefix | -prefix);
1188 /* should be called with rcu_read_lock */
1189 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
1190 struct fib_result *res, int fib_flags)
1192 struct trie *t = (struct trie *)tb->tb_data;
1193 #ifdef CONFIG_IP_FIB_TRIE_STATS
1194 struct trie_use_stats __percpu *stats = t->stats;
1196 const t_key key = ntohl(flp->daddr);
1197 struct tnode *n, *pn;
1198 struct leaf_info *li;
1201 n = rcu_dereference(t->trie);
1205 #ifdef CONFIG_IP_FIB_TRIE_STATS
1206 this_cpu_inc(stats->gets);
1212 /* Step 1: Travel to the longest prefix match in the trie */
1214 unsigned long index = get_index(key, n);
1216 /* This bit of code is a bit tricky but it combines multiple
1217 * checks into a single check. The prefix consists of the
1218 * prefix plus zeros for the "bits" in the prefix. The index
1219 * is the difference between the key and this value. From
1220 * this we can actually derive several pieces of data.
1221 * if !(index >> bits)
1222 * we know the value is child index
1224 * we have a mismatch in skip bits and failed
1226 if (index >> n->bits)
1229 /* we have found a leaf. Prefixes have already been compared */
1233 /* only record pn and cindex if we are going to be chopping
1234 * bits later. Otherwise we are just wasting cycles.
1241 n = rcu_dereference(n->child[index]);
1246 /* Step 2: Sort out leaves and begin backtracing for longest prefix */
1248 /* record the pointer where our next node pointer is stored */
1249 struct tnode __rcu **cptr = n->child;
1251 /* This test verifies that none of the bits that differ
1252 * between the key and the prefix exist in the region of
1253 * the lsb and higher in the prefix.
1255 if (unlikely(prefix_mismatch(key, n)))
1258 /* exit out and process leaf */
1259 if (unlikely(IS_LEAF(n)))
1262 /* Don't bother recording parent info. Since we are in
1263 * prefix match mode we will have to come back to wherever
1264 * we started this traversal anyway
1267 while ((n = rcu_dereference(*cptr)) == NULL) {
1269 #ifdef CONFIG_IP_FIB_TRIE_STATS
1271 this_cpu_inc(stats->null_node_hit);
1273 /* If we are at cindex 0 there are no more bits for
1274 * us to strip at this level so we must ascend back
1275 * up one level to see if there are any more bits to
1276 * be stripped there.
1279 t_key pkey = pn->key;
1281 pn = node_parent_rcu(pn);
1284 #ifdef CONFIG_IP_FIB_TRIE_STATS
1285 this_cpu_inc(stats->backtrack);
1287 /* Get Child's index */
1288 cindex = get_index(pkey, pn);
1291 /* strip the least significant bit from the cindex */
1292 cindex &= cindex - 1;
1294 /* grab pointer for next child node */
1295 cptr = &pn->child[cindex];
1300 /* Step 3: Process the leaf, if that fails fall back to backtracing */
1301 hlist_for_each_entry_rcu(li, &n->list, hlist) {
1302 struct fib_alias *fa;
1304 if ((key ^ n->key) & li->mask_plen)
1307 list_for_each_entry_rcu(fa, &li->falh, fa_list) {
1308 struct fib_info *fi = fa->fa_info;
1311 if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
1315 if (fa->fa_info->fib_scope < flp->flowi4_scope)
1317 fib_alias_accessed(fa);
1318 err = fib_props[fa->fa_type].error;
1319 if (unlikely(err < 0)) {
1320 #ifdef CONFIG_IP_FIB_TRIE_STATS
1321 this_cpu_inc(stats->semantic_match_passed);
1325 if (fi->fib_flags & RTNH_F_DEAD)
1327 for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) {
1328 const struct fib_nh *nh = &fi->fib_nh[nhsel];
1330 if (nh->nh_flags & RTNH_F_DEAD)
1332 if (flp->flowi4_oif && flp->flowi4_oif != nh->nh_oif)
1335 if (!(fib_flags & FIB_LOOKUP_NOREF))
1336 atomic_inc(&fi->fib_clntref);
1338 res->prefixlen = li->plen;
1339 res->nh_sel = nhsel;
1340 res->type = fa->fa_type;
1341 res->scope = fi->fib_scope;
1344 res->fa_head = &li->falh;
1345 #ifdef CONFIG_IP_FIB_TRIE_STATS
1346 this_cpu_inc(stats->semantic_match_passed);
1352 #ifdef CONFIG_IP_FIB_TRIE_STATS
1353 this_cpu_inc(stats->semantic_match_miss);
1358 EXPORT_SYMBOL_GPL(fib_table_lookup);
1361 * Remove the leaf and return parent.
1363 static void trie_leaf_remove(struct trie *t, struct tnode *l)
1365 struct tnode *tp = node_parent(l);
1367 pr_debug("entering trie_leaf_remove(%p)\n", l);
1370 put_child(tp, get_index(l->key, tp), NULL);
1371 trie_rebalance(t, tp);
1373 RCU_INIT_POINTER(t->trie, NULL);
1380 * Caller must hold RTNL.
1382 int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
1384 struct trie *t = (struct trie *) tb->tb_data;
1386 int plen = cfg->fc_dst_len;
1387 u8 tos = cfg->fc_tos;
1388 struct fib_alias *fa, *fa_to_delete;
1389 struct list_head *fa_head;
1391 struct leaf_info *li;
1396 key = ntohl(cfg->fc_dst);
1397 mask = ntohl(inet_make_mask(plen));
1403 l = fib_find_node(t, key);
1408 li = find_leaf_info(l, plen);
1413 fa_head = &li->falh;
1414 fa = fib_find_alias(fa_head, tos, 0);
1419 pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
1421 fa_to_delete = NULL;
1422 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
1423 list_for_each_entry_continue(fa, fa_head, fa_list) {
1424 struct fib_info *fi = fa->fa_info;
1426 if (fa->fa_tos != tos)
1429 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
1430 (cfg->fc_scope == RT_SCOPE_NOWHERE ||
1431 fa->fa_info->fib_scope == cfg->fc_scope) &&
1432 (!cfg->fc_prefsrc ||
1433 fi->fib_prefsrc == cfg->fc_prefsrc) &&
1434 (!cfg->fc_protocol ||
1435 fi->fib_protocol == cfg->fc_protocol) &&
1436 fib_nh_match(cfg, fi) == 0) {
1446 rtmsg_fib(RTM_DELROUTE, htonl(key), fa, plen, tb->tb_id,
1447 &cfg->fc_nlinfo, 0);
1449 list_del_rcu(&fa->fa_list);
1452 tb->tb_num_default--;
1454 if (list_empty(fa_head)) {
1455 hlist_del_rcu(&li->hlist);
1459 if (hlist_empty(&l->list))
1460 trie_leaf_remove(t, l);
1462 if (fa->fa_state & FA_S_ACCESSED)
1463 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1465 fib_release_info(fa->fa_info);
1466 alias_free_mem_rcu(fa);
1470 static int trie_flush_list(struct list_head *head)
1472 struct fib_alias *fa, *fa_node;
1475 list_for_each_entry_safe(fa, fa_node, head, fa_list) {
1476 struct fib_info *fi = fa->fa_info;
1478 if (fi && (fi->fib_flags & RTNH_F_DEAD)) {
1479 list_del_rcu(&fa->fa_list);
1480 fib_release_info(fa->fa_info);
1481 alias_free_mem_rcu(fa);
1488 static int trie_flush_leaf(struct tnode *l)
1491 struct hlist_head *lih = &l->list;
1492 struct hlist_node *tmp;
1493 struct leaf_info *li = NULL;
1495 hlist_for_each_entry_safe(li, tmp, lih, hlist) {
1496 found += trie_flush_list(&li->falh);
1498 if (list_empty(&li->falh)) {
1499 hlist_del_rcu(&li->hlist);
1507 * Scan for the next right leaf starting at node p->child[idx]
1508 * Since we have back pointer, no recursion necessary.
1510 static struct tnode *leaf_walk_rcu(struct tnode *p, struct tnode *c)
1513 unsigned long idx = c ? idx = get_index(c->key, p) + 1 : 0;
1515 while (idx < tnode_child_length(p)) {
1516 c = tnode_get_child_rcu(p, idx++);
1523 /* Rescan start scanning in new node */
1528 /* Node empty, walk back up to parent */
1530 } while ((p = node_parent_rcu(c)) != NULL);
1532 return NULL; /* Root of trie */
1535 static struct tnode *trie_firstleaf(struct trie *t)
1537 struct tnode *n = rcu_dereference_rtnl(t->trie);
1542 if (IS_LEAF(n)) /* trie is just a leaf */
1545 return leaf_walk_rcu(n, NULL);
1548 static struct tnode *trie_nextleaf(struct tnode *l)
1550 struct tnode *p = node_parent_rcu(l);
1553 return NULL; /* trie with just one leaf */
1555 return leaf_walk_rcu(p, l);
1558 static struct tnode *trie_leafindex(struct trie *t, int index)
1560 struct tnode *l = trie_firstleaf(t);
1562 while (l && index-- > 0)
1563 l = trie_nextleaf(l);
1570 * Caller must hold RTNL.
1572 int fib_table_flush(struct fib_table *tb)
1574 struct trie *t = (struct trie *) tb->tb_data;
1575 struct tnode *l, *ll = NULL;
1578 for (l = trie_firstleaf(t); l; l = trie_nextleaf(l)) {
1579 found += trie_flush_leaf(l);
1581 if (ll && hlist_empty(&ll->list))
1582 trie_leaf_remove(t, ll);
1586 if (ll && hlist_empty(&ll->list))
1587 trie_leaf_remove(t, ll);
1589 pr_debug("trie_flush found=%d\n", found);
1593 void fib_free_table(struct fib_table *tb)
1595 #ifdef CONFIG_IP_FIB_TRIE_STATS
1596 struct trie *t = (struct trie *)tb->tb_data;
1598 free_percpu(t->stats);
1599 #endif /* CONFIG_IP_FIB_TRIE_STATS */
1603 static int fn_trie_dump_fa(t_key key, int plen, struct list_head *fah,
1604 struct fib_table *tb,
1605 struct sk_buff *skb, struct netlink_callback *cb)
1608 struct fib_alias *fa;
1609 __be32 xkey = htonl(key);
1614 /* rcu_read_lock is hold by caller */
1616 list_for_each_entry_rcu(fa, fah, fa_list) {
1622 if (fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
1630 fa->fa_info, NLM_F_MULTI) < 0) {
1640 static int fn_trie_dump_leaf(struct tnode *l, struct fib_table *tb,
1641 struct sk_buff *skb, struct netlink_callback *cb)
1643 struct leaf_info *li;
1649 /* rcu_read_lock is hold by caller */
1650 hlist_for_each_entry_rcu(li, &l->list, hlist) {
1659 if (list_empty(&li->falh))
1662 if (fn_trie_dump_fa(l->key, li->plen, &li->falh, tb, skb, cb) < 0) {
1673 int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
1674 struct netlink_callback *cb)
1677 struct trie *t = (struct trie *) tb->tb_data;
1678 t_key key = cb->args[2];
1679 int count = cb->args[3];
1682 /* Dump starting at last key.
1683 * Note: 0.0.0.0/0 (ie default) is first key.
1686 l = trie_firstleaf(t);
1688 /* Normally, continue from last key, but if that is missing
1689 * fallback to using slow rescan
1691 l = fib_find_node(t, key);
1693 l = trie_leafindex(t, count);
1697 cb->args[2] = l->key;
1698 if (fn_trie_dump_leaf(l, tb, skb, cb) < 0) {
1699 cb->args[3] = count;
1705 l = trie_nextleaf(l);
1706 memset(&cb->args[4], 0,
1707 sizeof(cb->args) - 4*sizeof(cb->args[0]));
1709 cb->args[3] = count;
1715 void __init fib_trie_init(void)
1717 fn_alias_kmem = kmem_cache_create("ip_fib_alias",
1718 sizeof(struct fib_alias),
1719 0, SLAB_PANIC, NULL);
1721 trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
1722 max(sizeof(struct tnode),
1723 sizeof(struct leaf_info)),
1724 0, SLAB_PANIC, NULL);
1728 struct fib_table *fib_trie_table(u32 id)
1730 struct fib_table *tb;
1733 tb = kmalloc(sizeof(struct fib_table) + sizeof(struct trie),
1739 tb->tb_default = -1;
1740 tb->tb_num_default = 0;
1742 t = (struct trie *) tb->tb_data;
1743 RCU_INIT_POINTER(t->trie, NULL);
1744 #ifdef CONFIG_IP_FIB_TRIE_STATS
1745 t->stats = alloc_percpu(struct trie_use_stats);
1755 #ifdef CONFIG_PROC_FS
1756 /* Depth first Trie walk iterator */
1757 struct fib_trie_iter {
1758 struct seq_net_private p;
1759 struct fib_table *tb;
1760 struct tnode *tnode;
1765 static struct tnode *fib_trie_get_next(struct fib_trie_iter *iter)
1767 unsigned long cindex = iter->index;
1768 struct tnode *tn = iter->tnode;
1771 /* A single entry routing table */
1775 pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
1776 iter->tnode, iter->index, iter->depth);
1778 while (cindex < tnode_child_length(tn)) {
1779 struct tnode *n = tnode_get_child_rcu(tn, cindex);
1784 iter->index = cindex + 1;
1786 /* push down one level */
1797 /* Current node exhausted, pop back up */
1798 p = node_parent_rcu(tn);
1800 cindex = get_index(tn->key, p) + 1;
1810 static struct tnode *fib_trie_get_first(struct fib_trie_iter *iter,
1818 n = rcu_dereference(t->trie);
1835 static void trie_collect_stats(struct trie *t, struct trie_stat *s)
1838 struct fib_trie_iter iter;
1840 memset(s, 0, sizeof(*s));
1843 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) {
1845 struct leaf_info *li;
1848 s->totdepth += iter.depth;
1849 if (iter.depth > s->maxdepth)
1850 s->maxdepth = iter.depth;
1852 hlist_for_each_entry_rcu(li, &n->list, hlist)
1858 if (n->bits < MAX_STAT_DEPTH)
1859 s->nodesizes[n->bits]++;
1861 for (i = 0; i < tnode_child_length(n); i++) {
1862 if (!rcu_access_pointer(n->child[i]))
1871 * This outputs /proc/net/fib_triestats
1873 static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
1875 unsigned int i, max, pointers, bytes, avdepth;
1878 avdepth = stat->totdepth*100 / stat->leaves;
1882 seq_printf(seq, "\tAver depth: %u.%02d\n",
1883 avdepth / 100, avdepth % 100);
1884 seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth);
1886 seq_printf(seq, "\tLeaves: %u\n", stat->leaves);
1887 bytes = sizeof(struct tnode) * stat->leaves;
1889 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes);
1890 bytes += sizeof(struct leaf_info) * stat->prefixes;
1892 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);
1893 bytes += sizeof(struct tnode) * stat->tnodes;
1895 max = MAX_STAT_DEPTH;
1896 while (max > 0 && stat->nodesizes[max-1] == 0)
1900 for (i = 1; i < max; i++)
1901 if (stat->nodesizes[i] != 0) {
1902 seq_printf(seq, " %u: %u", i, stat->nodesizes[i]);
1903 pointers += (1<<i) * stat->nodesizes[i];
1905 seq_putc(seq, '\n');
1906 seq_printf(seq, "\tPointers: %u\n", pointers);
1908 bytes += sizeof(struct tnode *) * pointers;
1909 seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers);
1910 seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024);
1913 #ifdef CONFIG_IP_FIB_TRIE_STATS
1914 static void trie_show_usage(struct seq_file *seq,
1915 const struct trie_use_stats __percpu *stats)
1917 struct trie_use_stats s = { 0 };
1920 /* loop through all of the CPUs and gather up the stats */
1921 for_each_possible_cpu(cpu) {
1922 const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu);
1924 s.gets += pcpu->gets;
1925 s.backtrack += pcpu->backtrack;
1926 s.semantic_match_passed += pcpu->semantic_match_passed;
1927 s.semantic_match_miss += pcpu->semantic_match_miss;
1928 s.null_node_hit += pcpu->null_node_hit;
1929 s.resize_node_skipped += pcpu->resize_node_skipped;
1932 seq_printf(seq, "\nCounters:\n---------\n");
1933 seq_printf(seq, "gets = %u\n", s.gets);
1934 seq_printf(seq, "backtracks = %u\n", s.backtrack);
1935 seq_printf(seq, "semantic match passed = %u\n",
1936 s.semantic_match_passed);
1937 seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss);
1938 seq_printf(seq, "null node hit= %u\n", s.null_node_hit);
1939 seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped);
1941 #endif /* CONFIG_IP_FIB_TRIE_STATS */
1943 static void fib_table_print(struct seq_file *seq, struct fib_table *tb)
1945 if (tb->tb_id == RT_TABLE_LOCAL)
1946 seq_puts(seq, "Local:\n");
1947 else if (tb->tb_id == RT_TABLE_MAIN)
1948 seq_puts(seq, "Main:\n");
1950 seq_printf(seq, "Id %d:\n", tb->tb_id);
1954 static int fib_triestat_seq_show(struct seq_file *seq, void *v)
1956 struct net *net = (struct net *)seq->private;
1960 "Basic info: size of leaf:"
1961 " %Zd bytes, size of tnode: %Zd bytes.\n",
1962 sizeof(struct tnode), sizeof(struct tnode));
1964 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
1965 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
1966 struct fib_table *tb;
1968 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
1969 struct trie *t = (struct trie *) tb->tb_data;
1970 struct trie_stat stat;
1975 fib_table_print(seq, tb);
1977 trie_collect_stats(t, &stat);
1978 trie_show_stats(seq, &stat);
1979 #ifdef CONFIG_IP_FIB_TRIE_STATS
1980 trie_show_usage(seq, t->stats);
1988 static int fib_triestat_seq_open(struct inode *inode, struct file *file)
1990 return single_open_net(inode, file, fib_triestat_seq_show);
1993 static const struct file_operations fib_triestat_fops = {
1994 .owner = THIS_MODULE,
1995 .open = fib_triestat_seq_open,
1997 .llseek = seq_lseek,
1998 .release = single_release_net,
2001 static struct tnode *fib_trie_get_idx(struct seq_file *seq, loff_t pos)
2003 struct fib_trie_iter *iter = seq->private;
2004 struct net *net = seq_file_net(seq);
2008 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2009 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2010 struct fib_table *tb;
2012 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2015 for (n = fib_trie_get_first(iter,
2016 (struct trie *) tb->tb_data);
2017 n; n = fib_trie_get_next(iter))
2028 static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
2032 return fib_trie_get_idx(seq, *pos);
2035 static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2037 struct fib_trie_iter *iter = seq->private;
2038 struct net *net = seq_file_net(seq);
2039 struct fib_table *tb = iter->tb;
2040 struct hlist_node *tb_node;
2045 /* next node in same table */
2046 n = fib_trie_get_next(iter);
2050 /* walk rest of this hash chain */
2051 h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);
2052 while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) {
2053 tb = hlist_entry(tb_node, struct fib_table, tb_hlist);
2054 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2059 /* new hash chain */
2060 while (++h < FIB_TABLE_HASHSZ) {
2061 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2062 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2063 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2075 static void fib_trie_seq_stop(struct seq_file *seq, void *v)
2081 static void seq_indent(struct seq_file *seq, int n)
2087 static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
2090 case RT_SCOPE_UNIVERSE: return "universe";
2091 case RT_SCOPE_SITE: return "site";
2092 case RT_SCOPE_LINK: return "link";
2093 case RT_SCOPE_HOST: return "host";
2094 case RT_SCOPE_NOWHERE: return "nowhere";
2096 snprintf(buf, len, "scope=%d", s);
2101 static const char *const rtn_type_names[__RTN_MAX] = {
2102 [RTN_UNSPEC] = "UNSPEC",
2103 [RTN_UNICAST] = "UNICAST",
2104 [RTN_LOCAL] = "LOCAL",
2105 [RTN_BROADCAST] = "BROADCAST",
2106 [RTN_ANYCAST] = "ANYCAST",
2107 [RTN_MULTICAST] = "MULTICAST",
2108 [RTN_BLACKHOLE] = "BLACKHOLE",
2109 [RTN_UNREACHABLE] = "UNREACHABLE",
2110 [RTN_PROHIBIT] = "PROHIBIT",
2111 [RTN_THROW] = "THROW",
2113 [RTN_XRESOLVE] = "XRESOLVE",
2116 static inline const char *rtn_type(char *buf, size_t len, unsigned int t)
2118 if (t < __RTN_MAX && rtn_type_names[t])
2119 return rtn_type_names[t];
2120 snprintf(buf, len, "type %u", t);
2124 /* Pretty print the trie */
2125 static int fib_trie_seq_show(struct seq_file *seq, void *v)
2127 const struct fib_trie_iter *iter = seq->private;
2128 struct tnode *n = v;
2130 if (!node_parent_rcu(n))
2131 fib_table_print(seq, iter->tb);
2134 __be32 prf = htonl(n->key);
2136 seq_indent(seq, iter->depth-1);
2137 seq_printf(seq, " +-- %pI4/%zu %u %u %u\n",
2138 &prf, KEYLENGTH - n->pos - n->bits, n->bits,
2139 n->full_children, n->empty_children);
2141 struct leaf_info *li;
2142 __be32 val = htonl(n->key);
2144 seq_indent(seq, iter->depth);
2145 seq_printf(seq, " |-- %pI4\n", &val);
2147 hlist_for_each_entry_rcu(li, &n->list, hlist) {
2148 struct fib_alias *fa;
2150 list_for_each_entry_rcu(fa, &li->falh, fa_list) {
2151 char buf1[32], buf2[32];
2153 seq_indent(seq, iter->depth+1);
2154 seq_printf(seq, " /%d %s %s", li->plen,
2155 rtn_scope(buf1, sizeof(buf1),
2156 fa->fa_info->fib_scope),
2157 rtn_type(buf2, sizeof(buf2),
2160 seq_printf(seq, " tos=%d", fa->fa_tos);
2161 seq_putc(seq, '\n');
2169 static const struct seq_operations fib_trie_seq_ops = {
2170 .start = fib_trie_seq_start,
2171 .next = fib_trie_seq_next,
2172 .stop = fib_trie_seq_stop,
2173 .show = fib_trie_seq_show,
2176 static int fib_trie_seq_open(struct inode *inode, struct file *file)
2178 return seq_open_net(inode, file, &fib_trie_seq_ops,
2179 sizeof(struct fib_trie_iter));
2182 static const struct file_operations fib_trie_fops = {
2183 .owner = THIS_MODULE,
2184 .open = fib_trie_seq_open,
2186 .llseek = seq_lseek,
2187 .release = seq_release_net,
2190 struct fib_route_iter {
2191 struct seq_net_private p;
2192 struct trie *main_trie;
2197 static struct tnode *fib_route_get_idx(struct fib_route_iter *iter, loff_t pos)
2199 struct tnode *l = NULL;
2200 struct trie *t = iter->main_trie;
2202 /* use cache location of last found key */
2203 if (iter->pos > 0 && pos >= iter->pos && (l = fib_find_node(t, iter->key)))
2207 l = trie_firstleaf(t);
2210 while (l && pos-- > 0) {
2212 l = trie_nextleaf(l);
2216 iter->key = pos; /* remember it */
2218 iter->pos = 0; /* forget it */
2223 static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos)
2226 struct fib_route_iter *iter = seq->private;
2227 struct fib_table *tb;
2230 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
2234 iter->main_trie = (struct trie *) tb->tb_data;
2236 return SEQ_START_TOKEN;
2238 return fib_route_get_idx(iter, *pos - 1);
2241 static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2243 struct fib_route_iter *iter = seq->private;
2244 struct tnode *l = v;
2247 if (v == SEQ_START_TOKEN) {
2249 l = trie_firstleaf(iter->main_trie);
2252 l = trie_nextleaf(l);
2262 static void fib_route_seq_stop(struct seq_file *seq, void *v)
2268 static unsigned int fib_flag_trans(int type, __be32 mask, const struct fib_info *fi)
2270 unsigned int flags = 0;
2272 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT)
2274 if (fi && fi->fib_nh->nh_gw)
2275 flags |= RTF_GATEWAY;
2276 if (mask == htonl(0xFFFFFFFF))
2283 * This outputs /proc/net/route.
2284 * The format of the file is not supposed to be changed
2285 * and needs to be same as fib_hash output to avoid breaking
2288 static int fib_route_seq_show(struct seq_file *seq, void *v)
2290 struct tnode *l = v;
2291 struct leaf_info *li;
2293 if (v == SEQ_START_TOKEN) {
2294 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
2295 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
2300 hlist_for_each_entry_rcu(li, &l->list, hlist) {
2301 struct fib_alias *fa;
2302 __be32 mask, prefix;
2304 mask = inet_make_mask(li->plen);
2305 prefix = htonl(l->key);
2307 list_for_each_entry_rcu(fa, &li->falh, fa_list) {
2308 const struct fib_info *fi = fa->fa_info;
2309 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);
2311 if (fa->fa_type == RTN_BROADCAST
2312 || fa->fa_type == RTN_MULTICAST)
2315 seq_setwidth(seq, 127);
2319 "%s\t%08X\t%08X\t%04X\t%d\t%u\t"
2320 "%d\t%08X\t%d\t%u\t%u",
2321 fi->fib_dev ? fi->fib_dev->name : "*",
2323 fi->fib_nh->nh_gw, flags, 0, 0,
2327 fi->fib_advmss + 40 : 0),
2332 "*\t%08X\t%08X\t%04X\t%d\t%u\t"
2333 "%d\t%08X\t%d\t%u\t%u",
2334 prefix, 0, flags, 0, 0, 0,
2344 static const struct seq_operations fib_route_seq_ops = {
2345 .start = fib_route_seq_start,
2346 .next = fib_route_seq_next,
2347 .stop = fib_route_seq_stop,
2348 .show = fib_route_seq_show,
2351 static int fib_route_seq_open(struct inode *inode, struct file *file)
2353 return seq_open_net(inode, file, &fib_route_seq_ops,
2354 sizeof(struct fib_route_iter));
2357 static const struct file_operations fib_route_fops = {
2358 .owner = THIS_MODULE,
2359 .open = fib_route_seq_open,
2361 .llseek = seq_lseek,
2362 .release = seq_release_net,
2365 int __net_init fib_proc_init(struct net *net)
2367 if (!proc_create("fib_trie", S_IRUGO, net->proc_net, &fib_trie_fops))
2370 if (!proc_create("fib_triestat", S_IRUGO, net->proc_net,
2371 &fib_triestat_fops))
2374 if (!proc_create("route", S_IRUGO, net->proc_net, &fib_route_fops))
2380 remove_proc_entry("fib_triestat", net->proc_net);
2382 remove_proc_entry("fib_trie", net->proc_net);
2387 void __net_exit fib_proc_exit(struct net *net)
2389 remove_proc_entry("fib_trie", net->proc_net);
2390 remove_proc_entry("fib_triestat", net->proc_net);
2391 remove_proc_entry("route", net->proc_net);
2394 #endif /* CONFIG_PROC_FS */