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))
87 #define KEY_MAX ((t_key)~0)
89 typedef unsigned int t_key;
91 #define IS_TNODE(n) ((n)->bits)
92 #define IS_LEAF(n) (!(n)->bits)
94 #define get_index(_key, _kv) (((_key) ^ (_kv)->key) >> (_kv)->pos)
98 unsigned char bits; /* 2log(KEYLENGTH) bits needed */
99 unsigned char pos; /* 2log(KEYLENGTH) bits needed */
101 struct tnode __rcu *parent;
104 /* The fields in this struct are valid if bits > 0 (TNODE) */
106 t_key empty_children; /* KEYLENGTH bits needed */
107 t_key full_children; /* KEYLENGTH bits needed */
108 struct tnode __rcu *child[0];
110 /* This list pointer if valid if bits == 0 (LEAF) */
111 struct hlist_head list;
116 struct hlist_node hlist;
118 u32 mask_plen; /* ntohl(inet_make_mask(plen)) */
119 struct list_head falh;
123 #ifdef CONFIG_IP_FIB_TRIE_STATS
124 struct trie_use_stats {
126 unsigned int backtrack;
127 unsigned int semantic_match_passed;
128 unsigned int semantic_match_miss;
129 unsigned int null_node_hit;
130 unsigned int resize_node_skipped;
135 unsigned int totdepth;
136 unsigned int maxdepth;
139 unsigned int nullpointers;
140 unsigned int prefixes;
141 unsigned int nodesizes[MAX_STAT_DEPTH];
145 struct tnode __rcu *trie;
146 #ifdef CONFIG_IP_FIB_TRIE_STATS
147 struct trie_use_stats __percpu *stats;
151 static void resize(struct trie *t, struct tnode *tn);
152 static size_t tnode_free_size;
155 * synchronize_rcu after call_rcu for that many pages; it should be especially
156 * useful before resizing the root node with PREEMPT_NONE configs; the value was
157 * obtained experimentally, aiming to avoid visible slowdown.
159 static const int sync_pages = 128;
161 static struct kmem_cache *fn_alias_kmem __read_mostly;
162 static struct kmem_cache *trie_leaf_kmem __read_mostly;
164 /* caller must hold RTNL */
165 #define node_parent(n) rtnl_dereference((n)->parent)
167 /* caller must hold RCU read lock or RTNL */
168 #define node_parent_rcu(n) rcu_dereference_rtnl((n)->parent)
170 /* wrapper for rcu_assign_pointer */
171 static inline void node_set_parent(struct tnode *n, struct tnode *tp)
174 rcu_assign_pointer(n->parent, tp);
177 #define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER((n)->parent, p)
179 /* This provides us with the number of children in this node, in the case of a
180 * leaf this will return 0 meaning none of the children are accessible.
182 static inline unsigned long tnode_child_length(const struct tnode *tn)
184 return (1ul << tn->bits) & ~(1ul);
187 /* caller must hold RTNL */
188 static inline struct tnode *tnode_get_child(const struct tnode *tn,
191 return rtnl_dereference(tn->child[i]);
194 /* caller must hold RCU read lock or RTNL */
195 static inline struct tnode *tnode_get_child_rcu(const struct tnode *tn,
198 return rcu_dereference_rtnl(tn->child[i]);
201 /* To understand this stuff, an understanding of keys and all their bits is
202 * necessary. Every node in the trie has a key associated with it, but not
203 * all of the bits in that key are significant.
205 * Consider a node 'n' and its parent 'tp'.
207 * If n is a leaf, every bit in its key is significant. Its presence is
208 * necessitated by path compression, since during a tree traversal (when
209 * searching for a leaf - unless we are doing an insertion) we will completely
210 * ignore all skipped bits we encounter. Thus we need to verify, at the end of
211 * a potentially successful search, that we have indeed been walking the
214 * Note that we can never "miss" the correct key in the tree if present by
215 * following the wrong path. Path compression ensures that segments of the key
216 * that are the same for all keys with a given prefix are skipped, but the
217 * skipped part *is* identical for each node in the subtrie below the skipped
218 * bit! trie_insert() in this implementation takes care of that.
220 * if n is an internal node - a 'tnode' here, the various parts of its key
221 * have many different meanings.
224 * _________________________________________________________________
225 * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
226 * -----------------------------------------------------------------
227 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
229 * _________________________________________________________________
230 * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
231 * -----------------------------------------------------------------
232 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
239 * First, let's just ignore the bits that come before the parent tp, that is
240 * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this
241 * point we do not use them for anything.
243 * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the
244 * index into the parent's child array. That is, they will be used to find
245 * 'n' among tp's children.
247 * The bits from (n->pos + n->bits) to (tn->pos - 1) - "S" - are skipped bits
250 * All the bits we have seen so far are significant to the node n. The rest
251 * of the bits are really not needed or indeed known in n->key.
253 * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into
254 * n's child array, and will of course be different for each child.
256 * The rest of the bits, from 0 to (n->pos + n->bits), are completely unknown
260 static const int halve_threshold = 25;
261 static const int inflate_threshold = 50;
262 static const int halve_threshold_root = 15;
263 static const int inflate_threshold_root = 30;
265 static void __alias_free_mem(struct rcu_head *head)
267 struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
268 kmem_cache_free(fn_alias_kmem, fa);
271 static inline void alias_free_mem_rcu(struct fib_alias *fa)
273 call_rcu(&fa->rcu, __alias_free_mem);
276 #define TNODE_KMALLOC_MAX \
277 ilog2((PAGE_SIZE - sizeof(struct tnode)) / sizeof(struct tnode *))
279 static void __node_free_rcu(struct rcu_head *head)
281 struct tnode *n = container_of(head, struct tnode, rcu);
284 kmem_cache_free(trie_leaf_kmem, n);
285 else if (n->bits <= TNODE_KMALLOC_MAX)
291 #define node_free(n) call_rcu(&n->rcu, __node_free_rcu)
293 static inline void free_leaf_info(struct leaf_info *leaf)
295 kfree_rcu(leaf, rcu);
298 static struct tnode *tnode_alloc(size_t size)
300 if (size <= PAGE_SIZE)
301 return kzalloc(size, GFP_KERNEL);
303 return vzalloc(size);
306 static inline void empty_child_inc(struct tnode *n)
308 ++n->empty_children ? : ++n->full_children;
311 static inline void empty_child_dec(struct tnode *n)
313 n->empty_children-- ? : n->full_children--;
316 static struct tnode *leaf_new(t_key key)
318 struct tnode *l = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
321 /* set key and pos to reflect full key value
322 * any trailing zeros in the key should be ignored
323 * as the nodes are searched
328 /* set bits to 0 indicating we are not a tnode */
331 INIT_HLIST_HEAD(&l->list);
336 static struct leaf_info *leaf_info_new(int plen)
338 struct leaf_info *li = kmalloc(sizeof(struct leaf_info), GFP_KERNEL);
341 li->mask_plen = ntohl(inet_make_mask(plen));
342 INIT_LIST_HEAD(&li->falh);
347 static struct tnode *tnode_new(t_key key, int pos, int bits)
349 size_t sz = offsetof(struct tnode, child[1ul << bits]);
350 struct tnode *tn = tnode_alloc(sz);
351 unsigned int shift = pos + bits;
353 /* verify bits and pos their msb bits clear and values are valid */
354 BUG_ON(!bits || (shift > KEYLENGTH));
361 tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
362 if (bits == KEYLENGTH)
363 tn->full_children = 1;
365 tn->empty_children = 1ul << bits;
368 pr_debug("AT %p s=%zu %zu\n", tn, sizeof(struct tnode),
369 sizeof(struct tnode *) << bits);
373 /* Check whether a tnode 'n' is "full", i.e. it is an internal node
374 * and no bits are skipped. See discussion in dyntree paper p. 6
376 static inline int tnode_full(const struct tnode *tn, const struct tnode *n)
378 return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n);
381 /* Add a child at position i overwriting the old value.
382 * Update the value of full_children and empty_children.
384 static void put_child(struct tnode *tn, unsigned long i, struct tnode *n)
386 struct tnode *chi = tnode_get_child(tn, i);
389 BUG_ON(i >= tnode_child_length(tn));
391 /* update emptyChildren, overflow into fullChildren */
392 if (n == NULL && chi != NULL)
394 if (n != NULL && chi == NULL)
397 /* update fullChildren */
398 wasfull = tnode_full(tn, chi);
399 isfull = tnode_full(tn, n);
401 if (wasfull && !isfull)
403 else if (!wasfull && isfull)
406 if (n && (tn->slen < n->slen))
409 rcu_assign_pointer(tn->child[i], n);
412 static void update_children(struct tnode *tn)
416 /* update all of the child parent pointers */
417 for (i = tnode_child_length(tn); i;) {
418 struct tnode *inode = tnode_get_child(tn, --i);
423 /* Either update the children of a tnode that
424 * already belongs to us or update the child
425 * to point to ourselves.
427 if (node_parent(inode) == tn)
428 update_children(inode);
430 node_set_parent(inode, tn);
434 static inline void put_child_root(struct tnode *tp, struct trie *t,
435 t_key key, struct tnode *n)
438 put_child(tp, get_index(key, tp), n);
440 rcu_assign_pointer(t->trie, n);
443 static inline void tnode_free_init(struct tnode *tn)
448 static inline void tnode_free_append(struct tnode *tn, struct tnode *n)
450 n->rcu.next = tn->rcu.next;
451 tn->rcu.next = &n->rcu;
454 static void tnode_free(struct tnode *tn)
456 struct callback_head *head = &tn->rcu;
460 tnode_free_size += offsetof(struct tnode, child[1 << tn->bits]);
463 tn = container_of(head, struct tnode, rcu);
466 if (tnode_free_size >= PAGE_SIZE * sync_pages) {
472 static void replace(struct trie *t, struct tnode *oldtnode, struct tnode *tn)
474 struct tnode *tp = node_parent(oldtnode);
477 /* setup the parent pointer out of and back into this node */
478 NODE_INIT_PARENT(tn, tp);
479 put_child_root(tp, t, tn->key, tn);
481 /* update all of the child parent pointers */
484 /* all pointers should be clean so we are done */
485 tnode_free(oldtnode);
487 /* resize children now that oldtnode is freed */
488 for (i = tnode_child_length(tn); i;) {
489 struct tnode *inode = tnode_get_child(tn, --i);
491 /* resize child node */
492 if (tnode_full(tn, inode))
497 static int inflate(struct trie *t, struct tnode *oldtnode)
503 pr_debug("In inflate\n");
505 tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1);
509 /* prepare oldtnode to be freed */
510 tnode_free_init(oldtnode);
512 /* Assemble all of the pointers in our cluster, in this case that
513 * represents all of the pointers out of our allocated nodes that
514 * point to existing tnodes and the links between our allocated
517 for (i = tnode_child_length(oldtnode), m = 1u << tn->pos; i;) {
518 struct tnode *inode = tnode_get_child(oldtnode, --i);
519 struct tnode *node0, *node1;
526 /* A leaf or an internal node with skipped bits */
527 if (!tnode_full(oldtnode, inode)) {
528 put_child(tn, get_index(inode->key, tn), inode);
532 /* drop the node in the old tnode free list */
533 tnode_free_append(oldtnode, inode);
535 /* An internal node with two children */
536 if (inode->bits == 1) {
537 put_child(tn, 2 * i + 1, tnode_get_child(inode, 1));
538 put_child(tn, 2 * i, tnode_get_child(inode, 0));
542 /* We will replace this node 'inode' with two new
543 * ones, 'node0' and 'node1', each with half of the
544 * original children. The two new nodes will have
545 * a position one bit further down the key and this
546 * means that the "significant" part of their keys
547 * (see the discussion near the top of this file)
548 * will differ by one bit, which will be "0" in
549 * node0's key and "1" in node1's key. Since we are
550 * moving the key position by one step, the bit that
551 * we are moving away from - the bit at position
552 * (tn->pos) - is the one that will differ between
553 * node0 and node1. So... we synthesize that bit in the
556 node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1);
559 node0 = tnode_new(inode->key, inode->pos, inode->bits - 1);
561 tnode_free_append(tn, node1);
564 tnode_free_append(tn, node0);
566 /* populate child pointers in new nodes */
567 for (k = tnode_child_length(inode), j = k / 2; j;) {
568 put_child(node1, --j, tnode_get_child(inode, --k));
569 put_child(node0, j, tnode_get_child(inode, j));
570 put_child(node1, --j, tnode_get_child(inode, --k));
571 put_child(node0, j, tnode_get_child(inode, j));
574 /* link new nodes to parent */
575 NODE_INIT_PARENT(node1, tn);
576 NODE_INIT_PARENT(node0, tn);
578 /* link parent to nodes */
579 put_child(tn, 2 * i + 1, node1);
580 put_child(tn, 2 * i, node0);
583 /* setup the parent pointers into and out of this node */
584 replace(t, oldtnode, tn);
588 /* all pointers should be clean so we are done */
593 static int halve(struct trie *t, struct tnode *oldtnode)
598 pr_debug("In halve\n");
600 tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1);
604 /* prepare oldtnode to be freed */
605 tnode_free_init(oldtnode);
607 /* Assemble all of the pointers in our cluster, in this case that
608 * represents all of the pointers out of our allocated nodes that
609 * point to existing tnodes and the links between our allocated
612 for (i = tnode_child_length(oldtnode); i;) {
613 struct tnode *node1 = tnode_get_child(oldtnode, --i);
614 struct tnode *node0 = tnode_get_child(oldtnode, --i);
617 /* At least one of the children is empty */
618 if (!node1 || !node0) {
619 put_child(tn, i / 2, node1 ? : node0);
623 /* Two nonempty children */
624 inode = tnode_new(node0->key, oldtnode->pos, 1);
629 tnode_free_append(tn, inode);
631 /* initialize pointers out of node */
632 put_child(inode, 1, node1);
633 put_child(inode, 0, node0);
634 NODE_INIT_PARENT(inode, tn);
636 /* link parent to node */
637 put_child(tn, i / 2, inode);
640 /* setup the parent pointers into and out of this node */
641 replace(t, oldtnode, tn);
646 static void collapse(struct trie *t, struct tnode *oldtnode)
648 struct tnode *n, *tp;
651 /* scan the tnode looking for that one child that might still exist */
652 for (n = NULL, i = tnode_child_length(oldtnode); !n && i;)
653 n = tnode_get_child(oldtnode, --i);
655 /* compress one level */
656 tp = node_parent(oldtnode);
657 put_child_root(tp, t, oldtnode->key, n);
658 node_set_parent(n, tp);
664 static unsigned char update_suffix(struct tnode *tn)
666 unsigned char slen = tn->pos;
667 unsigned long stride, i;
669 /* search though the list of children looking for nodes that might
670 * have a suffix greater than the one we currently have. This is
671 * why we start with a stride of 2 since a stride of 1 would
672 * represent the nodes with suffix length equal to tn->pos
674 for (i = 0, stride = 0x2ul ; i < tnode_child_length(tn); i += stride) {
675 struct tnode *n = tnode_get_child(tn, i);
677 if (!n || (n->slen <= slen))
680 /* update stride and slen based on new value */
681 stride <<= (n->slen - slen);
685 /* if slen covers all but the last bit we can stop here
686 * there will be nothing longer than that since only node
687 * 0 and 1 << (bits - 1) could have that as their suffix
690 if ((slen + 1) >= (tn->pos + tn->bits))
699 /* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
700 * the Helsinki University of Technology and Matti Tikkanen of Nokia
701 * Telecommunications, page 6:
702 * "A node is doubled if the ratio of non-empty children to all
703 * children in the *doubled* node is at least 'high'."
705 * 'high' in this instance is the variable 'inflate_threshold'. It
706 * is expressed as a percentage, so we multiply it with
707 * tnode_child_length() and instead of multiplying by 2 (since the
708 * child array will be doubled by inflate()) and multiplying
709 * the left-hand side by 100 (to handle the percentage thing) we
710 * multiply the left-hand side by 50.
712 * The left-hand side may look a bit weird: tnode_child_length(tn)
713 * - tn->empty_children is of course the number of non-null children
714 * in the current node. tn->full_children is the number of "full"
715 * children, that is non-null tnodes with a skip value of 0.
716 * All of those will be doubled in the resulting inflated tnode, so
717 * we just count them one extra time here.
719 * A clearer way to write this would be:
721 * to_be_doubled = tn->full_children;
722 * not_to_be_doubled = tnode_child_length(tn) - tn->empty_children -
725 * new_child_length = tnode_child_length(tn) * 2;
727 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
729 * if (new_fill_factor >= inflate_threshold)
731 * ...and so on, tho it would mess up the while () loop.
734 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
738 * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
739 * inflate_threshold * new_child_length
741 * expand not_to_be_doubled and to_be_doubled, and shorten:
742 * 100 * (tnode_child_length(tn) - tn->empty_children +
743 * tn->full_children) >= inflate_threshold * new_child_length
745 * expand new_child_length:
746 * 100 * (tnode_child_length(tn) - tn->empty_children +
747 * tn->full_children) >=
748 * inflate_threshold * tnode_child_length(tn) * 2
751 * 50 * (tn->full_children + tnode_child_length(tn) -
752 * tn->empty_children) >= inflate_threshold *
753 * tnode_child_length(tn)
756 static bool should_inflate(const struct tnode *tp, const struct tnode *tn)
758 unsigned long used = tnode_child_length(tn);
759 unsigned long threshold = used;
761 /* Keep root node larger */
762 threshold *= tp ? inflate_threshold : inflate_threshold_root;
763 used -= tn->empty_children;
764 used += tn->full_children;
766 /* if bits == KEYLENGTH then pos = 0, and will fail below */
768 return (used > 1) && tn->pos && ((50 * used) >= threshold);
771 static bool should_halve(const struct tnode *tp, const struct tnode *tn)
773 unsigned long used = tnode_child_length(tn);
774 unsigned long threshold = used;
776 /* Keep root node larger */
777 threshold *= tp ? halve_threshold : halve_threshold_root;
778 used -= tn->empty_children;
780 /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */
782 return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold);
785 static bool should_collapse(const struct tnode *tn)
787 unsigned long used = tnode_child_length(tn);
789 used -= tn->empty_children;
791 /* account for bits == KEYLENGTH case */
792 if ((tn->bits == KEYLENGTH) && tn->full_children)
795 /* One child or none, time to drop us from the trie */
800 static void resize(struct trie *t, struct tnode *tn)
802 struct tnode *tp = node_parent(tn);
803 struct tnode __rcu **cptr;
804 int max_work = MAX_WORK;
806 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
807 tn, inflate_threshold, halve_threshold);
809 /* track the tnode via the pointer from the parent instead of
810 * doing it ourselves. This way we can let RCU fully do its
811 * thing without us interfering
813 cptr = tp ? &tp->child[get_index(tn->key, tp)] : &t->trie;
814 BUG_ON(tn != rtnl_dereference(*cptr));
816 /* Double as long as the resulting node has a number of
817 * nonempty nodes that are above the threshold.
819 while (should_inflate(tp, tn) && max_work) {
820 if (inflate(t, tn)) {
821 #ifdef CONFIG_IP_FIB_TRIE_STATS
822 this_cpu_inc(t->stats->resize_node_skipped);
828 tn = rtnl_dereference(*cptr);
831 /* Return if at least one inflate is run */
832 if (max_work != MAX_WORK)
835 /* Halve as long as the number of empty children in this
836 * node is above threshold.
838 while (should_halve(tp, tn) && max_work) {
840 #ifdef CONFIG_IP_FIB_TRIE_STATS
841 this_cpu_inc(t->stats->resize_node_skipped);
847 tn = rtnl_dereference(*cptr);
850 /* Only one child remains */
851 if (should_collapse(tn)) {
856 /* Return if at least one deflate was run */
857 if (max_work != MAX_WORK)
860 /* push the suffix length to the parent node */
861 if (tn->slen > tn->pos) {
862 unsigned char slen = update_suffix(tn);
864 if (tp && (slen > tp->slen))
869 /* readside must use rcu_read_lock currently dump routines
870 via get_fa_head and dump */
872 static struct leaf_info *find_leaf_info(struct tnode *l, int plen)
874 struct hlist_head *head = &l->list;
875 struct leaf_info *li;
877 hlist_for_each_entry_rcu(li, head, hlist)
878 if (li->plen == plen)
884 static inline struct list_head *get_fa_head(struct tnode *l, int plen)
886 struct leaf_info *li = find_leaf_info(l, plen);
894 static void leaf_pull_suffix(struct tnode *l)
896 struct tnode *tp = node_parent(l);
898 while (tp && (tp->slen > tp->pos) && (tp->slen > l->slen)) {
899 if (update_suffix(tp) > l->slen)
901 tp = node_parent(tp);
905 static void leaf_push_suffix(struct tnode *l)
907 struct tnode *tn = node_parent(l);
909 /* if this is a new leaf then tn will be NULL and we can sort
910 * out parent suffix lengths as a part of trie_rebalance
912 while (tn && (tn->slen < l->slen)) {
914 tn = node_parent(tn);
918 static void remove_leaf_info(struct tnode *l, struct leaf_info *old)
920 struct hlist_node *prev;
922 /* record the location of the pointer to this object */
923 prev = rtnl_dereference(hlist_pprev_rcu(&old->hlist));
925 /* remove the leaf info from the list */
926 hlist_del_rcu(&old->hlist);
928 /* if we emptied the list this leaf will be freed and we can sort
929 * out parent suffix lengths as a part of trie_rebalance
931 if (hlist_empty(&l->list))
934 /* if we removed the tail then we need to update slen */
935 if (!rcu_access_pointer(hlist_next_rcu(prev))) {
936 struct leaf_info *li = hlist_entry(prev, typeof(*li), hlist);
938 l->slen = KEYLENGTH - li->plen;
943 static void insert_leaf_info(struct tnode *l, struct leaf_info *new)
945 struct hlist_head *head = &l->list;
946 struct leaf_info *li = NULL, *last = NULL;
948 if (hlist_empty(head)) {
949 hlist_add_head_rcu(&new->hlist, head);
951 hlist_for_each_entry(li, head, hlist) {
952 if (new->plen > li->plen)
958 hlist_add_behind_rcu(&new->hlist, &last->hlist);
960 hlist_add_before_rcu(&new->hlist, &li->hlist);
963 /* if we added to the tail node then we need to update slen */
964 if (!rcu_access_pointer(hlist_next_rcu(&new->hlist))) {
965 l->slen = KEYLENGTH - new->plen;
970 /* rcu_read_lock needs to be hold by caller from readside */
971 static struct tnode *fib_find_node(struct trie *t, u32 key)
973 struct tnode *n = rcu_dereference_rtnl(t->trie);
976 unsigned long index = get_index(key, n);
978 /* This bit of code is a bit tricky but it combines multiple
979 * checks into a single check. The prefix consists of the
980 * prefix plus zeros for the bits in the cindex. The index
981 * is the difference between the key and this value. From
982 * this we can actually derive several pieces of data.
983 * if (index & (~0ul << bits))
984 * we have a mismatch in skip bits and failed
986 * we know the value is cindex
988 if (index & (~0ul << n->bits))
991 /* we have found a leaf. Prefixes have already been compared */
995 n = tnode_get_child_rcu(n, index);
1001 static void trie_rebalance(struct trie *t, struct tnode *tn)
1005 while ((tp = node_parent(tn)) != NULL) {
1010 /* Handle last (top) tnode */
1015 /* only used from updater-side */
1017 static struct list_head *fib_insert_node(struct trie *t, u32 key, int plen)
1019 struct list_head *fa_head = NULL;
1020 struct tnode *l, *n, *tp = NULL;
1021 struct leaf_info *li;
1023 li = leaf_info_new(plen);
1026 fa_head = &li->falh;
1028 n = rtnl_dereference(t->trie);
1030 /* If we point to NULL, stop. Either the tree is empty and we should
1031 * just put a new leaf in if, or we have reached an empty child slot,
1032 * and we should just put our new leaf in that.
1034 * If we hit a node with a key that does't match then we should stop
1035 * and create a new tnode to replace that node and insert ourselves
1036 * and the other node into the new tnode.
1039 unsigned long index = get_index(key, n);
1041 /* This bit of code is a bit tricky but it combines multiple
1042 * checks into a single check. The prefix consists of the
1043 * prefix plus zeros for the "bits" in the prefix. The index
1044 * is the difference between the key and this value. From
1045 * this we can actually derive several pieces of data.
1046 * if !(index >> bits)
1047 * we know the value is child index
1049 * we have a mismatch in skip bits and failed
1051 if (index >> n->bits)
1054 /* we have found a leaf. Prefixes have already been compared */
1056 /* Case 1: n is a leaf, and prefixes match*/
1057 insert_leaf_info(n, li);
1062 n = tnode_get_child_rcu(n, index);
1071 insert_leaf_info(l, li);
1073 /* Case 2: n is a LEAF or a TNODE and the key doesn't match.
1075 * Add a new tnode here
1076 * first tnode need some special handling
1077 * leaves us in position for handling as case 3
1082 tn = tnode_new(key, __fls(key ^ n->key), 1);
1089 /* initialize routes out of node */
1090 NODE_INIT_PARENT(tn, tp);
1091 put_child(tn, get_index(key, tn) ^ 1, n);
1093 /* start adding routes into the node */
1094 put_child_root(tp, t, key, tn);
1095 node_set_parent(n, tn);
1097 /* parent now has a NULL spot where the leaf can go */
1101 /* Case 3: n is NULL, and will just insert a new leaf */
1103 NODE_INIT_PARENT(l, tp);
1104 put_child(tp, get_index(key, tp), l);
1105 trie_rebalance(t, tp);
1107 rcu_assign_pointer(t->trie, l);
1114 * Caller must hold RTNL.
1116 int fib_table_insert(struct fib_table *tb, struct fib_config *cfg)
1118 struct trie *t = (struct trie *) tb->tb_data;
1119 struct fib_alias *fa, *new_fa;
1120 struct list_head *fa_head = NULL;
1121 struct fib_info *fi;
1122 int plen = cfg->fc_dst_len;
1123 u8 tos = cfg->fc_tos;
1131 key = ntohl(cfg->fc_dst);
1133 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
1135 mask = ntohl(inet_make_mask(plen));
1142 fi = fib_create_info(cfg);
1148 l = fib_find_node(t, key);
1152 fa_head = get_fa_head(l, plen);
1153 fa = fib_find_alias(fa_head, tos, fi->fib_priority);
1156 /* Now fa, if non-NULL, points to the first fib alias
1157 * with the same keys [prefix,tos,priority], if such key already
1158 * exists or to the node before which we will insert new one.
1160 * If fa is NULL, we will need to allocate a new one and
1161 * insert to the head of f.
1163 * If f is NULL, no fib node matched the destination key
1164 * and we need to allocate a new one of those as well.
1167 if (fa && fa->fa_tos == tos &&
1168 fa->fa_info->fib_priority == fi->fib_priority) {
1169 struct fib_alias *fa_first, *fa_match;
1172 if (cfg->fc_nlflags & NLM_F_EXCL)
1176 * 1. Find exact match for type, scope, fib_info to avoid
1178 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
1182 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
1183 list_for_each_entry_continue(fa, fa_head, fa_list) {
1184 if (fa->fa_tos != tos)
1186 if (fa->fa_info->fib_priority != fi->fib_priority)
1188 if (fa->fa_type == cfg->fc_type &&
1189 fa->fa_info == fi) {
1195 if (cfg->fc_nlflags & NLM_F_REPLACE) {
1196 struct fib_info *fi_drop;
1206 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1210 fi_drop = fa->fa_info;
1211 new_fa->fa_tos = fa->fa_tos;
1212 new_fa->fa_info = fi;
1213 new_fa->fa_type = cfg->fc_type;
1214 state = fa->fa_state;
1215 new_fa->fa_state = state & ~FA_S_ACCESSED;
1217 list_replace_rcu(&fa->fa_list, &new_fa->fa_list);
1218 alias_free_mem_rcu(fa);
1220 fib_release_info(fi_drop);
1221 if (state & FA_S_ACCESSED)
1222 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1223 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
1224 tb->tb_id, &cfg->fc_nlinfo, NLM_F_REPLACE);
1228 /* Error if we find a perfect match which
1229 * uses the same scope, type, and nexthop
1235 if (!(cfg->fc_nlflags & NLM_F_APPEND))
1239 if (!(cfg->fc_nlflags & NLM_F_CREATE))
1243 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1247 new_fa->fa_info = fi;
1248 new_fa->fa_tos = tos;
1249 new_fa->fa_type = cfg->fc_type;
1250 new_fa->fa_state = 0;
1252 * Insert new entry to the list.
1256 fa_head = fib_insert_node(t, key, plen);
1257 if (unlikely(!fa_head)) {
1259 goto out_free_new_fa;
1264 tb->tb_num_default++;
1266 list_add_tail_rcu(&new_fa->fa_list,
1267 (fa ? &fa->fa_list : fa_head));
1269 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1270 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, tb->tb_id,
1271 &cfg->fc_nlinfo, 0);
1276 kmem_cache_free(fn_alias_kmem, new_fa);
1278 fib_release_info(fi);
1283 static inline t_key prefix_mismatch(t_key key, struct tnode *n)
1285 t_key prefix = n->key;
1287 return (key ^ prefix) & (prefix | -prefix);
1290 /* should be called with rcu_read_lock */
1291 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
1292 struct fib_result *res, int fib_flags)
1294 struct trie *t = (struct trie *)tb->tb_data;
1295 #ifdef CONFIG_IP_FIB_TRIE_STATS
1296 struct trie_use_stats __percpu *stats = t->stats;
1298 const t_key key = ntohl(flp->daddr);
1299 struct tnode *n, *pn;
1300 struct leaf_info *li;
1303 n = rcu_dereference(t->trie);
1307 #ifdef CONFIG_IP_FIB_TRIE_STATS
1308 this_cpu_inc(stats->gets);
1314 /* Step 1: Travel to the longest prefix match in the trie */
1316 unsigned long index = get_index(key, n);
1318 /* This bit of code is a bit tricky but it combines multiple
1319 * checks into a single check. The prefix consists of the
1320 * prefix plus zeros for the "bits" in the prefix. The index
1321 * is the difference between the key and this value. From
1322 * this we can actually derive several pieces of data.
1323 * if (index & (~0ul << bits))
1324 * we have a mismatch in skip bits and failed
1326 * we know the value is cindex
1328 if (index & (~0ul << n->bits))
1331 /* we have found a leaf. Prefixes have already been compared */
1335 /* only record pn and cindex if we are going to be chopping
1336 * bits later. Otherwise we are just wasting cycles.
1338 if (n->slen > n->pos) {
1343 n = tnode_get_child_rcu(n, index);
1348 /* Step 2: Sort out leaves and begin backtracing for longest prefix */
1350 /* record the pointer where our next node pointer is stored */
1351 struct tnode __rcu **cptr = n->child;
1353 /* This test verifies that none of the bits that differ
1354 * between the key and the prefix exist in the region of
1355 * the lsb and higher in the prefix.
1357 if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos))
1360 /* exit out and process leaf */
1361 if (unlikely(IS_LEAF(n)))
1364 /* Don't bother recording parent info. Since we are in
1365 * prefix match mode we will have to come back to wherever
1366 * we started this traversal anyway
1369 while ((n = rcu_dereference(*cptr)) == NULL) {
1371 #ifdef CONFIG_IP_FIB_TRIE_STATS
1373 this_cpu_inc(stats->null_node_hit);
1375 /* If we are at cindex 0 there are no more bits for
1376 * us to strip at this level so we must ascend back
1377 * up one level to see if there are any more bits to
1378 * be stripped there.
1381 t_key pkey = pn->key;
1383 pn = node_parent_rcu(pn);
1386 #ifdef CONFIG_IP_FIB_TRIE_STATS
1387 this_cpu_inc(stats->backtrack);
1389 /* Get Child's index */
1390 cindex = get_index(pkey, pn);
1393 /* strip the least significant bit from the cindex */
1394 cindex &= cindex - 1;
1396 /* grab pointer for next child node */
1397 cptr = &pn->child[cindex];
1402 /* Step 3: Process the leaf, if that fails fall back to backtracing */
1403 hlist_for_each_entry_rcu(li, &n->list, hlist) {
1404 struct fib_alias *fa;
1406 if ((key ^ n->key) & li->mask_plen)
1409 list_for_each_entry_rcu(fa, &li->falh, fa_list) {
1410 struct fib_info *fi = fa->fa_info;
1413 if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
1417 if (fa->fa_info->fib_scope < flp->flowi4_scope)
1419 fib_alias_accessed(fa);
1420 err = fib_props[fa->fa_type].error;
1421 if (unlikely(err < 0)) {
1422 #ifdef CONFIG_IP_FIB_TRIE_STATS
1423 this_cpu_inc(stats->semantic_match_passed);
1427 if (fi->fib_flags & RTNH_F_DEAD)
1429 for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) {
1430 const struct fib_nh *nh = &fi->fib_nh[nhsel];
1432 if (nh->nh_flags & RTNH_F_DEAD)
1434 if (flp->flowi4_oif && flp->flowi4_oif != nh->nh_oif)
1437 if (!(fib_flags & FIB_LOOKUP_NOREF))
1438 atomic_inc(&fi->fib_clntref);
1440 res->prefixlen = li->plen;
1441 res->nh_sel = nhsel;
1442 res->type = fa->fa_type;
1443 res->scope = fi->fib_scope;
1446 res->fa_head = &li->falh;
1447 #ifdef CONFIG_IP_FIB_TRIE_STATS
1448 this_cpu_inc(stats->semantic_match_passed);
1454 #ifdef CONFIG_IP_FIB_TRIE_STATS
1455 this_cpu_inc(stats->semantic_match_miss);
1460 EXPORT_SYMBOL_GPL(fib_table_lookup);
1463 * Remove the leaf and return parent.
1465 static void trie_leaf_remove(struct trie *t, struct tnode *l)
1467 struct tnode *tp = node_parent(l);
1469 pr_debug("entering trie_leaf_remove(%p)\n", l);
1472 put_child(tp, get_index(l->key, tp), NULL);
1473 trie_rebalance(t, tp);
1475 RCU_INIT_POINTER(t->trie, NULL);
1482 * Caller must hold RTNL.
1484 int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
1486 struct trie *t = (struct trie *) tb->tb_data;
1488 int plen = cfg->fc_dst_len;
1489 u8 tos = cfg->fc_tos;
1490 struct fib_alias *fa, *fa_to_delete;
1491 struct list_head *fa_head;
1493 struct leaf_info *li;
1498 key = ntohl(cfg->fc_dst);
1499 mask = ntohl(inet_make_mask(plen));
1505 l = fib_find_node(t, key);
1510 li = find_leaf_info(l, plen);
1515 fa_head = &li->falh;
1516 fa = fib_find_alias(fa_head, tos, 0);
1521 pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
1523 fa_to_delete = NULL;
1524 fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
1525 list_for_each_entry_continue(fa, fa_head, fa_list) {
1526 struct fib_info *fi = fa->fa_info;
1528 if (fa->fa_tos != tos)
1531 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
1532 (cfg->fc_scope == RT_SCOPE_NOWHERE ||
1533 fa->fa_info->fib_scope == cfg->fc_scope) &&
1534 (!cfg->fc_prefsrc ||
1535 fi->fib_prefsrc == cfg->fc_prefsrc) &&
1536 (!cfg->fc_protocol ||
1537 fi->fib_protocol == cfg->fc_protocol) &&
1538 fib_nh_match(cfg, fi) == 0) {
1548 rtmsg_fib(RTM_DELROUTE, htonl(key), fa, plen, tb->tb_id,
1549 &cfg->fc_nlinfo, 0);
1551 list_del_rcu(&fa->fa_list);
1554 tb->tb_num_default--;
1556 if (list_empty(fa_head)) {
1557 remove_leaf_info(l, li);
1561 if (hlist_empty(&l->list))
1562 trie_leaf_remove(t, l);
1564 if (fa->fa_state & FA_S_ACCESSED)
1565 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1567 fib_release_info(fa->fa_info);
1568 alias_free_mem_rcu(fa);
1572 static int trie_flush_list(struct list_head *head)
1574 struct fib_alias *fa, *fa_node;
1577 list_for_each_entry_safe(fa, fa_node, head, fa_list) {
1578 struct fib_info *fi = fa->fa_info;
1580 if (fi && (fi->fib_flags & RTNH_F_DEAD)) {
1581 list_del_rcu(&fa->fa_list);
1582 fib_release_info(fa->fa_info);
1583 alias_free_mem_rcu(fa);
1590 static int trie_flush_leaf(struct tnode *l)
1593 struct hlist_head *lih = &l->list;
1594 struct hlist_node *tmp;
1595 struct leaf_info *li = NULL;
1597 hlist_for_each_entry_safe(li, tmp, lih, hlist) {
1598 found += trie_flush_list(&li->falh);
1600 if (list_empty(&li->falh)) {
1601 hlist_del_rcu(&li->hlist);
1609 * Scan for the next right leaf starting at node p->child[idx]
1610 * Since we have back pointer, no recursion necessary.
1612 static struct tnode *leaf_walk_rcu(struct tnode *p, struct tnode *c)
1615 unsigned long idx = c ? idx = get_index(c->key, p) + 1 : 0;
1617 while (idx < tnode_child_length(p)) {
1618 c = tnode_get_child_rcu(p, idx++);
1625 /* Rescan start scanning in new node */
1630 /* Node empty, walk back up to parent */
1632 } while ((p = node_parent_rcu(c)) != NULL);
1634 return NULL; /* Root of trie */
1637 static struct tnode *trie_firstleaf(struct trie *t)
1639 struct tnode *n = rcu_dereference_rtnl(t->trie);
1644 if (IS_LEAF(n)) /* trie is just a leaf */
1647 return leaf_walk_rcu(n, NULL);
1650 static struct tnode *trie_nextleaf(struct tnode *l)
1652 struct tnode *p = node_parent_rcu(l);
1655 return NULL; /* trie with just one leaf */
1657 return leaf_walk_rcu(p, l);
1660 static struct tnode *trie_leafindex(struct trie *t, int index)
1662 struct tnode *l = trie_firstleaf(t);
1664 while (l && index-- > 0)
1665 l = trie_nextleaf(l);
1672 * Caller must hold RTNL.
1674 int fib_table_flush(struct fib_table *tb)
1676 struct trie *t = (struct trie *) tb->tb_data;
1677 struct tnode *l, *ll = NULL;
1680 for (l = trie_firstleaf(t); l; l = trie_nextleaf(l)) {
1681 found += trie_flush_leaf(l);
1683 if (ll && hlist_empty(&ll->list))
1684 trie_leaf_remove(t, ll);
1688 if (ll && hlist_empty(&ll->list))
1689 trie_leaf_remove(t, ll);
1691 pr_debug("trie_flush found=%d\n", found);
1695 void fib_free_table(struct fib_table *tb)
1697 #ifdef CONFIG_IP_FIB_TRIE_STATS
1698 struct trie *t = (struct trie *)tb->tb_data;
1700 free_percpu(t->stats);
1701 #endif /* CONFIG_IP_FIB_TRIE_STATS */
1705 static int fn_trie_dump_fa(t_key key, int plen, struct list_head *fah,
1706 struct fib_table *tb,
1707 struct sk_buff *skb, struct netlink_callback *cb)
1710 struct fib_alias *fa;
1711 __be32 xkey = htonl(key);
1716 /* rcu_read_lock is hold by caller */
1718 list_for_each_entry_rcu(fa, fah, fa_list) {
1724 if (fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
1732 fa->fa_info, NLM_F_MULTI) < 0) {
1742 static int fn_trie_dump_leaf(struct tnode *l, struct fib_table *tb,
1743 struct sk_buff *skb, struct netlink_callback *cb)
1745 struct leaf_info *li;
1751 /* rcu_read_lock is hold by caller */
1752 hlist_for_each_entry_rcu(li, &l->list, hlist) {
1761 if (list_empty(&li->falh))
1764 if (fn_trie_dump_fa(l->key, li->plen, &li->falh, tb, skb, cb) < 0) {
1775 int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
1776 struct netlink_callback *cb)
1779 struct trie *t = (struct trie *) tb->tb_data;
1780 t_key key = cb->args[2];
1781 int count = cb->args[3];
1784 /* Dump starting at last key.
1785 * Note: 0.0.0.0/0 (ie default) is first key.
1788 l = trie_firstleaf(t);
1790 /* Normally, continue from last key, but if that is missing
1791 * fallback to using slow rescan
1793 l = fib_find_node(t, key);
1795 l = trie_leafindex(t, count);
1799 cb->args[2] = l->key;
1800 if (fn_trie_dump_leaf(l, tb, skb, cb) < 0) {
1801 cb->args[3] = count;
1807 l = trie_nextleaf(l);
1808 memset(&cb->args[4], 0,
1809 sizeof(cb->args) - 4*sizeof(cb->args[0]));
1811 cb->args[3] = count;
1817 void __init fib_trie_init(void)
1819 fn_alias_kmem = kmem_cache_create("ip_fib_alias",
1820 sizeof(struct fib_alias),
1821 0, SLAB_PANIC, NULL);
1823 trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
1824 max(sizeof(struct tnode),
1825 sizeof(struct leaf_info)),
1826 0, SLAB_PANIC, NULL);
1830 struct fib_table *fib_trie_table(u32 id)
1832 struct fib_table *tb;
1835 tb = kmalloc(sizeof(struct fib_table) + sizeof(struct trie),
1841 tb->tb_default = -1;
1842 tb->tb_num_default = 0;
1844 t = (struct trie *) tb->tb_data;
1845 RCU_INIT_POINTER(t->trie, NULL);
1846 #ifdef CONFIG_IP_FIB_TRIE_STATS
1847 t->stats = alloc_percpu(struct trie_use_stats);
1857 #ifdef CONFIG_PROC_FS
1858 /* Depth first Trie walk iterator */
1859 struct fib_trie_iter {
1860 struct seq_net_private p;
1861 struct fib_table *tb;
1862 struct tnode *tnode;
1867 static struct tnode *fib_trie_get_next(struct fib_trie_iter *iter)
1869 unsigned long cindex = iter->index;
1870 struct tnode *tn = iter->tnode;
1873 /* A single entry routing table */
1877 pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
1878 iter->tnode, iter->index, iter->depth);
1880 while (cindex < tnode_child_length(tn)) {
1881 struct tnode *n = tnode_get_child_rcu(tn, cindex);
1886 iter->index = cindex + 1;
1888 /* push down one level */
1899 /* Current node exhausted, pop back up */
1900 p = node_parent_rcu(tn);
1902 cindex = get_index(tn->key, p) + 1;
1912 static struct tnode *fib_trie_get_first(struct fib_trie_iter *iter,
1920 n = rcu_dereference(t->trie);
1937 static void trie_collect_stats(struct trie *t, struct trie_stat *s)
1940 struct fib_trie_iter iter;
1942 memset(s, 0, sizeof(*s));
1945 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) {
1947 struct leaf_info *li;
1950 s->totdepth += iter.depth;
1951 if (iter.depth > s->maxdepth)
1952 s->maxdepth = iter.depth;
1954 hlist_for_each_entry_rcu(li, &n->list, hlist)
1960 if (n->bits < MAX_STAT_DEPTH)
1961 s->nodesizes[n->bits]++;
1963 for (i = tnode_child_length(n); i--;) {
1964 if (!rcu_access_pointer(n->child[i]))
1973 * This outputs /proc/net/fib_triestats
1975 static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
1977 unsigned int i, max, pointers, bytes, avdepth;
1980 avdepth = stat->totdepth*100 / stat->leaves;
1984 seq_printf(seq, "\tAver depth: %u.%02d\n",
1985 avdepth / 100, avdepth % 100);
1986 seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth);
1988 seq_printf(seq, "\tLeaves: %u\n", stat->leaves);
1989 bytes = sizeof(struct tnode) * stat->leaves;
1991 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes);
1992 bytes += sizeof(struct leaf_info) * stat->prefixes;
1994 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);
1995 bytes += sizeof(struct tnode) * stat->tnodes;
1997 max = MAX_STAT_DEPTH;
1998 while (max > 0 && stat->nodesizes[max-1] == 0)
2002 for (i = 1; i < max; i++)
2003 if (stat->nodesizes[i] != 0) {
2004 seq_printf(seq, " %u: %u", i, stat->nodesizes[i]);
2005 pointers += (1<<i) * stat->nodesizes[i];
2007 seq_putc(seq, '\n');
2008 seq_printf(seq, "\tPointers: %u\n", pointers);
2010 bytes += sizeof(struct tnode *) * pointers;
2011 seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers);
2012 seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024);
2015 #ifdef CONFIG_IP_FIB_TRIE_STATS
2016 static void trie_show_usage(struct seq_file *seq,
2017 const struct trie_use_stats __percpu *stats)
2019 struct trie_use_stats s = { 0 };
2022 /* loop through all of the CPUs and gather up the stats */
2023 for_each_possible_cpu(cpu) {
2024 const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu);
2026 s.gets += pcpu->gets;
2027 s.backtrack += pcpu->backtrack;
2028 s.semantic_match_passed += pcpu->semantic_match_passed;
2029 s.semantic_match_miss += pcpu->semantic_match_miss;
2030 s.null_node_hit += pcpu->null_node_hit;
2031 s.resize_node_skipped += pcpu->resize_node_skipped;
2034 seq_printf(seq, "\nCounters:\n---------\n");
2035 seq_printf(seq, "gets = %u\n", s.gets);
2036 seq_printf(seq, "backtracks = %u\n", s.backtrack);
2037 seq_printf(seq, "semantic match passed = %u\n",
2038 s.semantic_match_passed);
2039 seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss);
2040 seq_printf(seq, "null node hit= %u\n", s.null_node_hit);
2041 seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped);
2043 #endif /* CONFIG_IP_FIB_TRIE_STATS */
2045 static void fib_table_print(struct seq_file *seq, struct fib_table *tb)
2047 if (tb->tb_id == RT_TABLE_LOCAL)
2048 seq_puts(seq, "Local:\n");
2049 else if (tb->tb_id == RT_TABLE_MAIN)
2050 seq_puts(seq, "Main:\n");
2052 seq_printf(seq, "Id %d:\n", tb->tb_id);
2056 static int fib_triestat_seq_show(struct seq_file *seq, void *v)
2058 struct net *net = (struct net *)seq->private;
2062 "Basic info: size of leaf:"
2063 " %Zd bytes, size of tnode: %Zd bytes.\n",
2064 sizeof(struct tnode), sizeof(struct tnode));
2066 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2067 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2068 struct fib_table *tb;
2070 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2071 struct trie *t = (struct trie *) tb->tb_data;
2072 struct trie_stat stat;
2077 fib_table_print(seq, tb);
2079 trie_collect_stats(t, &stat);
2080 trie_show_stats(seq, &stat);
2081 #ifdef CONFIG_IP_FIB_TRIE_STATS
2082 trie_show_usage(seq, t->stats);
2090 static int fib_triestat_seq_open(struct inode *inode, struct file *file)
2092 return single_open_net(inode, file, fib_triestat_seq_show);
2095 static const struct file_operations fib_triestat_fops = {
2096 .owner = THIS_MODULE,
2097 .open = fib_triestat_seq_open,
2099 .llseek = seq_lseek,
2100 .release = single_release_net,
2103 static struct tnode *fib_trie_get_idx(struct seq_file *seq, loff_t pos)
2105 struct fib_trie_iter *iter = seq->private;
2106 struct net *net = seq_file_net(seq);
2110 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2111 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2112 struct fib_table *tb;
2114 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2117 for (n = fib_trie_get_first(iter,
2118 (struct trie *) tb->tb_data);
2119 n; n = fib_trie_get_next(iter))
2130 static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
2134 return fib_trie_get_idx(seq, *pos);
2137 static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2139 struct fib_trie_iter *iter = seq->private;
2140 struct net *net = seq_file_net(seq);
2141 struct fib_table *tb = iter->tb;
2142 struct hlist_node *tb_node;
2147 /* next node in same table */
2148 n = fib_trie_get_next(iter);
2152 /* walk rest of this hash chain */
2153 h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);
2154 while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) {
2155 tb = hlist_entry(tb_node, struct fib_table, tb_hlist);
2156 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2161 /* new hash chain */
2162 while (++h < FIB_TABLE_HASHSZ) {
2163 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2164 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2165 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2177 static void fib_trie_seq_stop(struct seq_file *seq, void *v)
2183 static void seq_indent(struct seq_file *seq, int n)
2189 static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
2192 case RT_SCOPE_UNIVERSE: return "universe";
2193 case RT_SCOPE_SITE: return "site";
2194 case RT_SCOPE_LINK: return "link";
2195 case RT_SCOPE_HOST: return "host";
2196 case RT_SCOPE_NOWHERE: return "nowhere";
2198 snprintf(buf, len, "scope=%d", s);
2203 static const char *const rtn_type_names[__RTN_MAX] = {
2204 [RTN_UNSPEC] = "UNSPEC",
2205 [RTN_UNICAST] = "UNICAST",
2206 [RTN_LOCAL] = "LOCAL",
2207 [RTN_BROADCAST] = "BROADCAST",
2208 [RTN_ANYCAST] = "ANYCAST",
2209 [RTN_MULTICAST] = "MULTICAST",
2210 [RTN_BLACKHOLE] = "BLACKHOLE",
2211 [RTN_UNREACHABLE] = "UNREACHABLE",
2212 [RTN_PROHIBIT] = "PROHIBIT",
2213 [RTN_THROW] = "THROW",
2215 [RTN_XRESOLVE] = "XRESOLVE",
2218 static inline const char *rtn_type(char *buf, size_t len, unsigned int t)
2220 if (t < __RTN_MAX && rtn_type_names[t])
2221 return rtn_type_names[t];
2222 snprintf(buf, len, "type %u", t);
2226 /* Pretty print the trie */
2227 static int fib_trie_seq_show(struct seq_file *seq, void *v)
2229 const struct fib_trie_iter *iter = seq->private;
2230 struct tnode *n = v;
2232 if (!node_parent_rcu(n))
2233 fib_table_print(seq, iter->tb);
2236 __be32 prf = htonl(n->key);
2238 seq_indent(seq, iter->depth-1);
2239 seq_printf(seq, " +-- %pI4/%zu %u %u %u\n",
2240 &prf, KEYLENGTH - n->pos - n->bits, n->bits,
2241 n->full_children, n->empty_children);
2243 struct leaf_info *li;
2244 __be32 val = htonl(n->key);
2246 seq_indent(seq, iter->depth);
2247 seq_printf(seq, " |-- %pI4\n", &val);
2249 hlist_for_each_entry_rcu(li, &n->list, hlist) {
2250 struct fib_alias *fa;
2252 list_for_each_entry_rcu(fa, &li->falh, fa_list) {
2253 char buf1[32], buf2[32];
2255 seq_indent(seq, iter->depth+1);
2256 seq_printf(seq, " /%d %s %s", li->plen,
2257 rtn_scope(buf1, sizeof(buf1),
2258 fa->fa_info->fib_scope),
2259 rtn_type(buf2, sizeof(buf2),
2262 seq_printf(seq, " tos=%d", fa->fa_tos);
2263 seq_putc(seq, '\n');
2271 static const struct seq_operations fib_trie_seq_ops = {
2272 .start = fib_trie_seq_start,
2273 .next = fib_trie_seq_next,
2274 .stop = fib_trie_seq_stop,
2275 .show = fib_trie_seq_show,
2278 static int fib_trie_seq_open(struct inode *inode, struct file *file)
2280 return seq_open_net(inode, file, &fib_trie_seq_ops,
2281 sizeof(struct fib_trie_iter));
2284 static const struct file_operations fib_trie_fops = {
2285 .owner = THIS_MODULE,
2286 .open = fib_trie_seq_open,
2288 .llseek = seq_lseek,
2289 .release = seq_release_net,
2292 struct fib_route_iter {
2293 struct seq_net_private p;
2294 struct trie *main_trie;
2299 static struct tnode *fib_route_get_idx(struct fib_route_iter *iter, loff_t pos)
2301 struct tnode *l = NULL;
2302 struct trie *t = iter->main_trie;
2304 /* use cache location of last found key */
2305 if (iter->pos > 0 && pos >= iter->pos && (l = fib_find_node(t, iter->key)))
2309 l = trie_firstleaf(t);
2312 while (l && pos-- > 0) {
2314 l = trie_nextleaf(l);
2318 iter->key = pos; /* remember it */
2320 iter->pos = 0; /* forget it */
2325 static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos)
2328 struct fib_route_iter *iter = seq->private;
2329 struct fib_table *tb;
2332 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
2336 iter->main_trie = (struct trie *) tb->tb_data;
2338 return SEQ_START_TOKEN;
2340 return fib_route_get_idx(iter, *pos - 1);
2343 static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2345 struct fib_route_iter *iter = seq->private;
2346 struct tnode *l = v;
2349 if (v == SEQ_START_TOKEN) {
2351 l = trie_firstleaf(iter->main_trie);
2354 l = trie_nextleaf(l);
2364 static void fib_route_seq_stop(struct seq_file *seq, void *v)
2370 static unsigned int fib_flag_trans(int type, __be32 mask, const struct fib_info *fi)
2372 unsigned int flags = 0;
2374 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT)
2376 if (fi && fi->fib_nh->nh_gw)
2377 flags |= RTF_GATEWAY;
2378 if (mask == htonl(0xFFFFFFFF))
2385 * This outputs /proc/net/route.
2386 * The format of the file is not supposed to be changed
2387 * and needs to be same as fib_hash output to avoid breaking
2390 static int fib_route_seq_show(struct seq_file *seq, void *v)
2392 struct tnode *l = v;
2393 struct leaf_info *li;
2395 if (v == SEQ_START_TOKEN) {
2396 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
2397 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
2402 hlist_for_each_entry_rcu(li, &l->list, hlist) {
2403 struct fib_alias *fa;
2404 __be32 mask, prefix;
2406 mask = inet_make_mask(li->plen);
2407 prefix = htonl(l->key);
2409 list_for_each_entry_rcu(fa, &li->falh, fa_list) {
2410 const struct fib_info *fi = fa->fa_info;
2411 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);
2413 if (fa->fa_type == RTN_BROADCAST
2414 || fa->fa_type == RTN_MULTICAST)
2417 seq_setwidth(seq, 127);
2421 "%s\t%08X\t%08X\t%04X\t%d\t%u\t"
2422 "%d\t%08X\t%d\t%u\t%u",
2423 fi->fib_dev ? fi->fib_dev->name : "*",
2425 fi->fib_nh->nh_gw, flags, 0, 0,
2429 fi->fib_advmss + 40 : 0),
2434 "*\t%08X\t%08X\t%04X\t%d\t%u\t"
2435 "%d\t%08X\t%d\t%u\t%u",
2436 prefix, 0, flags, 0, 0, 0,
2446 static const struct seq_operations fib_route_seq_ops = {
2447 .start = fib_route_seq_start,
2448 .next = fib_route_seq_next,
2449 .stop = fib_route_seq_stop,
2450 .show = fib_route_seq_show,
2453 static int fib_route_seq_open(struct inode *inode, struct file *file)
2455 return seq_open_net(inode, file, &fib_route_seq_ops,
2456 sizeof(struct fib_route_iter));
2459 static const struct file_operations fib_route_fops = {
2460 .owner = THIS_MODULE,
2461 .open = fib_route_seq_open,
2463 .llseek = seq_lseek,
2464 .release = seq_release_net,
2467 int __net_init fib_proc_init(struct net *net)
2469 if (!proc_create("fib_trie", S_IRUGO, net->proc_net, &fib_trie_fops))
2472 if (!proc_create("fib_triestat", S_IRUGO, net->proc_net,
2473 &fib_triestat_fops))
2476 if (!proc_create("route", S_IRUGO, net->proc_net, &fib_route_fops))
2482 remove_proc_entry("fib_triestat", net->proc_net);
2484 remove_proc_entry("fib_trie", net->proc_net);
2489 void __net_exit fib_proc_exit(struct net *net)
2491 remove_proc_entry("fib_trie", net->proc_net);
2492 remove_proc_entry("fib_triestat", net->proc_net);
2493 remove_proc_entry("route", net->proc_net);
2496 #endif /* CONFIG_PROC_FS */