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 <net/switchdev.h>
83 #include "fib_lookup.h"
85 #define MAX_STAT_DEPTH 32
87 #define KEYLENGTH (8*sizeof(t_key))
88 #define KEY_MAX ((t_key)~0)
90 typedef unsigned int t_key;
92 #define IS_TNODE(n) ((n)->bits)
93 #define IS_LEAF(n) (!(n)->bits)
96 t_key empty_children; /* KEYLENGTH bits needed */
97 t_key full_children; /* KEYLENGTH bits needed */
98 struct key_vector __rcu *parent;
101 unsigned char pos; /* 2log(KEYLENGTH) bits needed */
102 unsigned char bits; /* 2log(KEYLENGTH) bits needed */
105 /* This list pointer if valid if (pos | bits) == 0 (LEAF) */
106 struct hlist_head leaf;
107 /* This array is valid if (pos | bits) > 0 (TNODE) */
108 struct key_vector __rcu *tnode[0];
114 struct key_vector kv[1];
115 #define tn_bits kv[0].bits
118 #define TNODE_SIZE(n) offsetof(struct tnode, kv[0].tnode[n])
119 #define LEAF_SIZE TNODE_SIZE(1)
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 key_vector __rcu *tnode[1];
144 #ifdef CONFIG_IP_FIB_TRIE_STATS
145 struct trie_use_stats __percpu *stats;
149 static struct key_vector **resize(struct trie *t, struct key_vector *tn);
150 static size_t tnode_free_size;
153 * synchronize_rcu after call_rcu for that many pages; it should be especially
154 * useful before resizing the root node with PREEMPT_NONE configs; the value was
155 * obtained experimentally, aiming to avoid visible slowdown.
157 static const int sync_pages = 128;
159 static struct kmem_cache *fn_alias_kmem __read_mostly;
160 static struct kmem_cache *trie_leaf_kmem __read_mostly;
162 static inline struct tnode *tn_info(struct key_vector *kv)
164 return container_of(kv, struct tnode, kv[0]);
167 /* caller must hold RTNL */
168 #define node_parent(n) rtnl_dereference((n)->parent)
169 #define get_child(tn, i) rtnl_dereference((tn)->tnode[i])
171 /* caller must hold RCU read lock or RTNL */
172 #define node_parent_rcu(n) rcu_dereference_rtnl((n)->parent)
173 #define get_child_rcu(tn, i) rcu_dereference_rtnl((tn)->tnode[i])
175 /* wrapper for rcu_assign_pointer */
176 static inline void node_set_parent(struct key_vector *n, struct key_vector *tp)
179 rcu_assign_pointer(n->parent, tp);
182 #define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER((n)->parent, p)
184 /* This provides us with the number of children in this node, in the case of a
185 * leaf this will return 0 meaning none of the children are accessible.
187 static inline unsigned long child_length(const struct key_vector *tn)
189 return (1ul << tn->bits) & ~(1ul);
192 static inline unsigned long get_index(t_key key, struct key_vector *kv)
194 unsigned long index = key ^ kv->key;
196 return index >> kv->pos;
199 /* To understand this stuff, an understanding of keys and all their bits is
200 * necessary. Every node in the trie has a key associated with it, but not
201 * all of the bits in that key are significant.
203 * Consider a node 'n' and its parent 'tp'.
205 * If n is a leaf, every bit in its key is significant. Its presence is
206 * necessitated by path compression, since during a tree traversal (when
207 * searching for a leaf - unless we are doing an insertion) we will completely
208 * ignore all skipped bits we encounter. Thus we need to verify, at the end of
209 * a potentially successful search, that we have indeed been walking the
212 * Note that we can never "miss" the correct key in the tree if present by
213 * following the wrong path. Path compression ensures that segments of the key
214 * that are the same for all keys with a given prefix are skipped, but the
215 * skipped part *is* identical for each node in the subtrie below the skipped
216 * bit! trie_insert() in this implementation takes care of that.
218 * if n is an internal node - a 'tnode' here, the various parts of its key
219 * have many different meanings.
222 * _________________________________________________________________
223 * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
224 * -----------------------------------------------------------------
225 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
227 * _________________________________________________________________
228 * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
229 * -----------------------------------------------------------------
230 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
237 * First, let's just ignore the bits that come before the parent tp, that is
238 * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this
239 * point we do not use them for anything.
241 * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the
242 * index into the parent's child array. That is, they will be used to find
243 * 'n' among tp's children.
245 * The bits from (n->pos + n->bits) to (tn->pos - 1) - "S" - are skipped bits
248 * All the bits we have seen so far are significant to the node n. The rest
249 * of the bits are really not needed or indeed known in n->key.
251 * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into
252 * n's child array, and will of course be different for each child.
254 * The rest of the bits, from 0 to (n->pos + n->bits), are completely unknown
258 static const int halve_threshold = 25;
259 static const int inflate_threshold = 50;
260 static const int halve_threshold_root = 15;
261 static const int inflate_threshold_root = 30;
263 static void __alias_free_mem(struct rcu_head *head)
265 struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
266 kmem_cache_free(fn_alias_kmem, fa);
269 static inline void alias_free_mem_rcu(struct fib_alias *fa)
271 call_rcu(&fa->rcu, __alias_free_mem);
274 #define TNODE_KMALLOC_MAX \
275 ilog2((PAGE_SIZE - TNODE_SIZE(0)) / sizeof(struct key_vector *))
276 #define TNODE_VMALLOC_MAX \
277 ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *))
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->tn_bits <= TNODE_KMALLOC_MAX)
291 #define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu)
293 static struct tnode *tnode_alloc(int bits)
297 /* verify bits is within bounds */
298 if (bits > TNODE_VMALLOC_MAX)
301 /* determine size and verify it is non-zero and didn't overflow */
302 size = TNODE_SIZE(1ul << bits);
304 if (size <= PAGE_SIZE)
305 return kzalloc(size, GFP_KERNEL);
307 return vzalloc(size);
310 static inline void empty_child_inc(struct key_vector *n)
312 ++n->empty_children ? : ++n->full_children;
315 static inline void empty_child_dec(struct key_vector *n)
317 n->empty_children-- ? : n->full_children--;
320 static struct key_vector *leaf_new(t_key key, struct fib_alias *fa)
322 struct tnode *kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
323 struct key_vector *l = kv->kv;
328 /* initialize key vector */
332 l->slen = fa->fa_slen;
334 /* link leaf to fib alias */
335 INIT_HLIST_HEAD(&l->leaf);
336 hlist_add_head(&fa->fa_list, &l->leaf);
341 static struct key_vector *tnode_new(t_key key, int pos, int bits)
343 struct tnode *tnode = tnode_alloc(bits);
344 unsigned int shift = pos + bits;
345 struct key_vector *tn = tnode->kv;
347 /* verify bits and pos their msb bits clear and values are valid */
348 BUG_ON(!bits || (shift > KEYLENGTH));
350 pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0),
351 sizeof(struct key_vector *) << bits);
356 if (bits == KEYLENGTH)
357 tn->full_children = 1;
359 tn->empty_children = 1ul << bits;
361 tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
369 /* Check whether a tnode 'n' is "full", i.e. it is an internal node
370 * and no bits are skipped. See discussion in dyntree paper p. 6
372 static inline int tnode_full(struct key_vector *tn, struct key_vector *n)
374 return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n);
377 /* Add a child at position i overwriting the old value.
378 * Update the value of full_children and empty_children.
380 static void put_child(struct key_vector *tn, unsigned long i,
381 struct key_vector *n)
383 struct key_vector *chi = get_child(tn, i);
386 BUG_ON(i >= child_length(tn));
388 /* update emptyChildren, overflow into fullChildren */
389 if (n == NULL && chi != NULL)
391 if (n != NULL && chi == NULL)
394 /* update fullChildren */
395 wasfull = tnode_full(tn, chi);
396 isfull = tnode_full(tn, n);
398 if (wasfull && !isfull)
400 else if (!wasfull && isfull)
403 if (n && (tn->slen < n->slen))
406 rcu_assign_pointer(tn->tnode[i], n);
409 static void update_children(struct key_vector *tn)
413 /* update all of the child parent pointers */
414 for (i = child_length(tn); i;) {
415 struct key_vector *inode = get_child(tn, --i);
420 /* Either update the children of a tnode that
421 * already belongs to us or update the child
422 * to point to ourselves.
424 if (node_parent(inode) == tn)
425 update_children(inode);
427 node_set_parent(inode, tn);
431 static inline void put_child_root(struct key_vector *tp, struct trie *t,
432 t_key key, struct key_vector *n)
435 put_child(tp, get_index(key, tp), n);
437 rcu_assign_pointer(t->tnode[0], n);
440 static inline void tnode_free_init(struct key_vector *tn)
442 tn_info(tn)->rcu.next = NULL;
445 static inline void tnode_free_append(struct key_vector *tn,
446 struct key_vector *n)
448 tn_info(n)->rcu.next = tn_info(tn)->rcu.next;
449 tn_info(tn)->rcu.next = &tn_info(n)->rcu;
452 static void tnode_free(struct key_vector *tn)
454 struct callback_head *head = &tn_info(tn)->rcu;
458 tnode_free_size += TNODE_SIZE(1ul << tn->bits);
461 tn = container_of(head, struct tnode, rcu)->kv;
464 if (tnode_free_size >= PAGE_SIZE * sync_pages) {
470 static struct key_vector __rcu **replace(struct trie *t,
471 struct key_vector *oldtnode,
472 struct key_vector *tn)
474 struct key_vector *tp = node_parent(oldtnode);
475 struct key_vector **cptr;
478 /* setup the parent pointer out of and back into this node */
479 NODE_INIT_PARENT(tn, tp);
480 put_child_root(tp, t, tn->key, tn);
482 /* update all of the child parent pointers */
485 /* all pointers should be clean so we are done */
486 tnode_free(oldtnode);
488 /* record the pointer that is pointing to this node */
489 cptr = tp ? tp->tnode : t->tnode;
491 /* resize children now that oldtnode is freed */
492 for (i = child_length(tn); i;) {
493 struct key_vector *inode = get_child(tn, --i);
495 /* resize child node */
496 if (tnode_full(tn, inode))
503 static struct key_vector __rcu **inflate(struct trie *t,
504 struct key_vector *oldtnode)
506 struct key_vector *tn;
510 pr_debug("In inflate\n");
512 tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1);
516 /* prepare oldtnode to be freed */
517 tnode_free_init(oldtnode);
519 /* Assemble all of the pointers in our cluster, in this case that
520 * represents all of the pointers out of our allocated nodes that
521 * point to existing tnodes and the links between our allocated
524 for (i = child_length(oldtnode), m = 1u << tn->pos; i;) {
525 struct key_vector *inode = get_child(oldtnode, --i);
526 struct key_vector *node0, *node1;
533 /* A leaf or an internal node with skipped bits */
534 if (!tnode_full(oldtnode, inode)) {
535 put_child(tn, get_index(inode->key, tn), inode);
539 /* drop the node in the old tnode free list */
540 tnode_free_append(oldtnode, inode);
542 /* An internal node with two children */
543 if (inode->bits == 1) {
544 put_child(tn, 2 * i + 1, get_child(inode, 1));
545 put_child(tn, 2 * i, get_child(inode, 0));
549 /* We will replace this node 'inode' with two new
550 * ones, 'node0' and 'node1', each with half of the
551 * original children. The two new nodes will have
552 * a position one bit further down the key and this
553 * means that the "significant" part of their keys
554 * (see the discussion near the top of this file)
555 * will differ by one bit, which will be "0" in
556 * node0's key and "1" in node1's key. Since we are
557 * moving the key position by one step, the bit that
558 * we are moving away from - the bit at position
559 * (tn->pos) - is the one that will differ between
560 * node0 and node1. So... we synthesize that bit in the
563 node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1);
566 node0 = tnode_new(inode->key, inode->pos, inode->bits - 1);
568 tnode_free_append(tn, node1);
571 tnode_free_append(tn, node0);
573 /* populate child pointers in new nodes */
574 for (k = child_length(inode), j = k / 2; j;) {
575 put_child(node1, --j, get_child(inode, --k));
576 put_child(node0, j, get_child(inode, j));
577 put_child(node1, --j, get_child(inode, --k));
578 put_child(node0, j, get_child(inode, j));
581 /* link new nodes to parent */
582 NODE_INIT_PARENT(node1, tn);
583 NODE_INIT_PARENT(node0, tn);
585 /* link parent to nodes */
586 put_child(tn, 2 * i + 1, node1);
587 put_child(tn, 2 * i, node0);
590 /* setup the parent pointers into and out of this node */
591 return replace(t, oldtnode, tn);
593 /* all pointers should be clean so we are done */
599 static struct key_vector __rcu **halve(struct trie *t,
600 struct key_vector *oldtnode)
602 struct key_vector *tn;
605 pr_debug("In halve\n");
607 tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1);
611 /* prepare oldtnode to be freed */
612 tnode_free_init(oldtnode);
614 /* Assemble all of the pointers in our cluster, in this case that
615 * represents all of the pointers out of our allocated nodes that
616 * point to existing tnodes and the links between our allocated
619 for (i = child_length(oldtnode); i;) {
620 struct key_vector *node1 = get_child(oldtnode, --i);
621 struct key_vector *node0 = get_child(oldtnode, --i);
622 struct key_vector *inode;
624 /* At least one of the children is empty */
625 if (!node1 || !node0) {
626 put_child(tn, i / 2, node1 ? : node0);
630 /* Two nonempty children */
631 inode = tnode_new(node0->key, oldtnode->pos, 1);
634 tnode_free_append(tn, inode);
636 /* initialize pointers out of node */
637 put_child(inode, 1, node1);
638 put_child(inode, 0, node0);
639 NODE_INIT_PARENT(inode, tn);
641 /* link parent to node */
642 put_child(tn, i / 2, inode);
645 /* setup the parent pointers into and out of this node */
646 return replace(t, oldtnode, tn);
648 /* all pointers should be clean so we are done */
654 static void collapse(struct trie *t, struct key_vector *oldtnode)
656 struct key_vector *n, *tp;
659 /* scan the tnode looking for that one child that might still exist */
660 for (n = NULL, i = child_length(oldtnode); !n && i;)
661 n = get_child(oldtnode, --i);
663 /* compress one level */
664 tp = node_parent(oldtnode);
665 put_child_root(tp, t, oldtnode->key, n);
666 node_set_parent(n, tp);
672 static unsigned char update_suffix(struct key_vector *tn)
674 unsigned char slen = tn->pos;
675 unsigned long stride, i;
677 /* search though the list of children looking for nodes that might
678 * have a suffix greater than the one we currently have. This is
679 * why we start with a stride of 2 since a stride of 1 would
680 * represent the nodes with suffix length equal to tn->pos
682 for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) {
683 struct key_vector *n = get_child(tn, i);
685 if (!n || (n->slen <= slen))
688 /* update stride and slen based on new value */
689 stride <<= (n->slen - slen);
693 /* if slen covers all but the last bit we can stop here
694 * there will be nothing longer than that since only node
695 * 0 and 1 << (bits - 1) could have that as their suffix
698 if ((slen + 1) >= (tn->pos + tn->bits))
707 /* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
708 * the Helsinki University of Technology and Matti Tikkanen of Nokia
709 * Telecommunications, page 6:
710 * "A node is doubled if the ratio of non-empty children to all
711 * children in the *doubled* node is at least 'high'."
713 * 'high' in this instance is the variable 'inflate_threshold'. It
714 * is expressed as a percentage, so we multiply it with
715 * child_length() and instead of multiplying by 2 (since the
716 * child array will be doubled by inflate()) and multiplying
717 * the left-hand side by 100 (to handle the percentage thing) we
718 * multiply the left-hand side by 50.
720 * The left-hand side may look a bit weird: child_length(tn)
721 * - tn->empty_children is of course the number of non-null children
722 * in the current node. tn->full_children is the number of "full"
723 * children, that is non-null tnodes with a skip value of 0.
724 * All of those will be doubled in the resulting inflated tnode, so
725 * we just count them one extra time here.
727 * A clearer way to write this would be:
729 * to_be_doubled = tn->full_children;
730 * not_to_be_doubled = child_length(tn) - tn->empty_children -
733 * new_child_length = child_length(tn) * 2;
735 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
737 * if (new_fill_factor >= inflate_threshold)
739 * ...and so on, tho it would mess up the while () loop.
742 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
746 * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
747 * inflate_threshold * new_child_length
749 * expand not_to_be_doubled and to_be_doubled, and shorten:
750 * 100 * (child_length(tn) - tn->empty_children +
751 * tn->full_children) >= inflate_threshold * new_child_length
753 * expand new_child_length:
754 * 100 * (child_length(tn) - tn->empty_children +
755 * tn->full_children) >=
756 * inflate_threshold * child_length(tn) * 2
759 * 50 * (tn->full_children + child_length(tn) -
760 * tn->empty_children) >= inflate_threshold *
764 static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn)
766 unsigned long used = child_length(tn);
767 unsigned long threshold = used;
769 /* Keep root node larger */
770 threshold *= tp ? inflate_threshold : inflate_threshold_root;
771 used -= tn->empty_children;
772 used += tn->full_children;
774 /* if bits == KEYLENGTH then pos = 0, and will fail below */
776 return (used > 1) && tn->pos && ((50 * used) >= threshold);
779 static inline bool should_halve(struct key_vector *tp, struct key_vector *tn)
781 unsigned long used = child_length(tn);
782 unsigned long threshold = used;
784 /* Keep root node larger */
785 threshold *= tp ? halve_threshold : halve_threshold_root;
786 used -= tn->empty_children;
788 /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */
790 return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold);
793 static inline bool should_collapse(struct key_vector *tn)
795 unsigned long used = child_length(tn);
797 used -= tn->empty_children;
799 /* account for bits == KEYLENGTH case */
800 if ((tn->bits == KEYLENGTH) && tn->full_children)
803 /* One child or none, time to drop us from the trie */
808 static struct key_vector __rcu **resize(struct trie *t,
809 struct key_vector *tn)
811 #ifdef CONFIG_IP_FIB_TRIE_STATS
812 struct trie_use_stats __percpu *stats = t->stats;
814 struct key_vector *tp = node_parent(tn);
815 unsigned long cindex = tp ? get_index(tn->key, tp) : 0;
816 struct key_vector __rcu **cptr = tp ? tp->tnode : t->tnode;
817 int max_work = MAX_WORK;
819 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
820 tn, inflate_threshold, halve_threshold);
822 /* track the tnode via the pointer from the parent instead of
823 * doing it ourselves. This way we can let RCU fully do its
824 * thing without us interfering
826 BUG_ON(tn != rtnl_dereference(cptr[cindex]));
828 /* Double as long as the resulting node has a number of
829 * nonempty nodes that are above the threshold.
831 while (should_inflate(tp, tn) && max_work) {
832 struct key_vector __rcu **tcptr = inflate(t, tn);
835 #ifdef CONFIG_IP_FIB_TRIE_STATS
836 this_cpu_inc(stats->resize_node_skipped);
843 tn = rtnl_dereference(cptr[cindex]);
846 /* Return if at least one inflate is run */
847 if (max_work != MAX_WORK)
850 /* Halve as long as the number of empty children in this
851 * node is above threshold.
853 while (should_halve(tp, tn) && max_work) {
854 struct key_vector __rcu **tcptr = halve(t, tn);
857 #ifdef CONFIG_IP_FIB_TRIE_STATS
858 this_cpu_inc(stats->resize_node_skipped);
865 tn = rtnl_dereference(cptr[cindex]);
868 /* Only one child remains */
869 if (should_collapse(tn)) {
874 /* Return if at least one deflate was run */
875 if (max_work != MAX_WORK)
878 /* push the suffix length to the parent node */
879 if (tn->slen > tn->pos) {
880 unsigned char slen = update_suffix(tn);
882 if (tp && (slen > tp->slen))
889 static void leaf_pull_suffix(struct key_vector *tp, struct key_vector *l)
891 while (tp && (tp->slen > tp->pos) && (tp->slen > l->slen)) {
892 if (update_suffix(tp) > l->slen)
894 tp = node_parent(tp);
898 static void leaf_push_suffix(struct key_vector *tn, struct key_vector *l)
900 /* if this is a new leaf then tn will be NULL and we can sort
901 * out parent suffix lengths as a part of trie_rebalance
903 while (tn && (tn->slen < l->slen)) {
905 tn = node_parent(tn);
909 /* rcu_read_lock needs to be hold by caller from readside */
910 static struct key_vector *fib_find_node(struct trie *t,
911 struct key_vector **tp, u32 key)
913 struct key_vector *pn = NULL, *n = rcu_dereference_rtnl(t->tnode[0]);
916 unsigned long index = get_index(key, n);
918 /* This bit of code is a bit tricky but it combines multiple
919 * checks into a single check. The prefix consists of the
920 * prefix plus zeros for the bits in the cindex. The index
921 * is the difference between the key and this value. From
922 * this we can actually derive several pieces of data.
923 * if (index >= (1ul << bits))
924 * we have a mismatch in skip bits and failed
926 * we know the value is cindex
928 * This check is safe even if bits == KEYLENGTH due to the
929 * fact that we can only allocate a node with 32 bits if a
930 * long is greater than 32 bits.
932 if (index >= (1ul << n->bits)) {
937 /* we have found a leaf. Prefixes have already been compared */
942 n = get_child_rcu(n, index);
950 /* Return the first fib alias matching TOS with
951 * priority less than or equal to PRIO.
953 static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen,
956 struct fib_alias *fa;
961 hlist_for_each_entry(fa, fah, fa_list) {
962 if (fa->fa_slen < slen)
964 if (fa->fa_slen != slen)
966 if (fa->fa_tos > tos)
968 if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos)
975 static void trie_rebalance(struct trie *t, struct key_vector *tn)
977 struct key_vector __rcu **cptr = t->tnode;
980 struct key_vector *tp = node_parent(tn);
982 cptr = resize(t, tn);
985 tn = container_of(cptr, struct key_vector, tnode[0]);
989 static int fib_insert_node(struct trie *t, struct key_vector *tp,
990 struct fib_alias *new, t_key key)
992 struct key_vector *n, *l;
994 l = leaf_new(key, new);
998 /* retrieve child from parent node */
1000 n = get_child(tp, get_index(key, tp));
1002 n = rcu_dereference_rtnl(t->tnode[0]);
1004 /* Case 2: n is a LEAF or a TNODE and the key doesn't match.
1006 * Add a new tnode here
1007 * first tnode need some special handling
1008 * leaves us in position for handling as case 3
1011 struct key_vector *tn;
1013 tn = tnode_new(key, __fls(key ^ n->key), 1);
1017 /* initialize routes out of node */
1018 NODE_INIT_PARENT(tn, tp);
1019 put_child(tn, get_index(key, tn) ^ 1, n);
1021 /* start adding routes into the node */
1022 put_child_root(tp, t, key, tn);
1023 node_set_parent(n, tn);
1025 /* parent now has a NULL spot where the leaf can go */
1029 /* Case 3: n is NULL, and will just insert a new leaf */
1030 NODE_INIT_PARENT(l, tp);
1031 put_child_root(tp, t, key, l);
1032 trie_rebalance(t, tp);
1041 static int fib_insert_alias(struct trie *t, struct key_vector *tp,
1042 struct key_vector *l, struct fib_alias *new,
1043 struct fib_alias *fa, t_key key)
1046 return fib_insert_node(t, tp, new, key);
1049 hlist_add_before_rcu(&new->fa_list, &fa->fa_list);
1051 struct fib_alias *last;
1053 hlist_for_each_entry(last, &l->leaf, fa_list) {
1054 if (new->fa_slen < last->fa_slen)
1060 hlist_add_behind_rcu(&new->fa_list, &fa->fa_list);
1062 hlist_add_head_rcu(&new->fa_list, &l->leaf);
1065 /* if we added to the tail node then we need to update slen */
1066 if (l->slen < new->fa_slen) {
1067 l->slen = new->fa_slen;
1068 leaf_push_suffix(tp, l);
1074 /* Caller must hold RTNL. */
1075 int fib_table_insert(struct fib_table *tb, struct fib_config *cfg)
1077 struct trie *t = (struct trie *)tb->tb_data;
1078 struct fib_alias *fa, *new_fa;
1079 struct key_vector *l, *tp;
1080 struct fib_info *fi;
1081 u8 plen = cfg->fc_dst_len;
1082 u8 slen = KEYLENGTH - plen;
1083 u8 tos = cfg->fc_tos;
1087 if (plen > KEYLENGTH)
1090 key = ntohl(cfg->fc_dst);
1092 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
1094 if ((plen < KEYLENGTH) && (key << plen))
1097 fi = fib_create_info(cfg);
1103 l = fib_find_node(t, &tp, key);
1104 fa = l ? fib_find_alias(&l->leaf, slen, tos, fi->fib_priority) : NULL;
1106 /* Now fa, if non-NULL, points to the first fib alias
1107 * with the same keys [prefix,tos,priority], if such key already
1108 * exists or to the node before which we will insert new one.
1110 * If fa is NULL, we will need to allocate a new one and
1111 * insert to the tail of the section matching the suffix length
1115 if (fa && fa->fa_tos == tos &&
1116 fa->fa_info->fib_priority == fi->fib_priority) {
1117 struct fib_alias *fa_first, *fa_match;
1120 if (cfg->fc_nlflags & NLM_F_EXCL)
1124 * 1. Find exact match for type, scope, fib_info to avoid
1126 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
1130 hlist_for_each_entry_from(fa, fa_list) {
1131 if ((fa->fa_slen != slen) || (fa->fa_tos != tos))
1133 if (fa->fa_info->fib_priority != fi->fib_priority)
1135 if (fa->fa_type == cfg->fc_type &&
1136 fa->fa_info == fi) {
1142 if (cfg->fc_nlflags & NLM_F_REPLACE) {
1143 struct fib_info *fi_drop;
1153 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1157 fi_drop = fa->fa_info;
1158 new_fa->fa_tos = fa->fa_tos;
1159 new_fa->fa_info = fi;
1160 new_fa->fa_type = cfg->fc_type;
1161 state = fa->fa_state;
1162 new_fa->fa_state = state & ~FA_S_ACCESSED;
1163 new_fa->fa_slen = fa->fa_slen;
1165 err = netdev_switch_fib_ipv4_add(key, plen, fi,
1170 netdev_switch_fib_ipv4_abort(fi);
1171 kmem_cache_free(fn_alias_kmem, new_fa);
1175 hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list);
1177 alias_free_mem_rcu(fa);
1179 fib_release_info(fi_drop);
1180 if (state & FA_S_ACCESSED)
1181 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1182 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
1183 tb->tb_id, &cfg->fc_nlinfo, NLM_F_REPLACE);
1187 /* Error if we find a perfect match which
1188 * uses the same scope, type, and nexthop
1194 if (!(cfg->fc_nlflags & NLM_F_APPEND))
1198 if (!(cfg->fc_nlflags & NLM_F_CREATE))
1202 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1206 new_fa->fa_info = fi;
1207 new_fa->fa_tos = tos;
1208 new_fa->fa_type = cfg->fc_type;
1209 new_fa->fa_state = 0;
1210 new_fa->fa_slen = slen;
1212 /* (Optionally) offload fib entry to switch hardware. */
1213 err = netdev_switch_fib_ipv4_add(key, plen, fi, tos,
1214 cfg->fc_type, tb->tb_id);
1216 netdev_switch_fib_ipv4_abort(fi);
1217 goto out_free_new_fa;
1220 /* Insert new entry to the list. */
1221 err = fib_insert_alias(t, tp, l, new_fa, fa, key);
1223 goto out_sw_fib_del;
1226 tb->tb_num_default++;
1228 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1229 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, tb->tb_id,
1230 &cfg->fc_nlinfo, 0);
1235 netdev_switch_fib_ipv4_del(key, plen, fi, tos, cfg->fc_type, tb->tb_id);
1237 kmem_cache_free(fn_alias_kmem, new_fa);
1239 fib_release_info(fi);
1244 static inline t_key prefix_mismatch(t_key key, struct key_vector *n)
1246 t_key prefix = n->key;
1248 return (key ^ prefix) & (prefix | -prefix);
1251 /* should be called with rcu_read_lock */
1252 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
1253 struct fib_result *res, int fib_flags)
1255 struct trie *t = (struct trie *)tb->tb_data;
1256 #ifdef CONFIG_IP_FIB_TRIE_STATS
1257 struct trie_use_stats __percpu *stats = t->stats;
1259 const t_key key = ntohl(flp->daddr);
1260 struct key_vector *n, *pn;
1261 struct fib_alias *fa;
1262 unsigned long index;
1265 n = rcu_dereference(t->tnode[0]);
1269 #ifdef CONFIG_IP_FIB_TRIE_STATS
1270 this_cpu_inc(stats->gets);
1276 /* Step 1: Travel to the longest prefix match in the trie */
1278 index = get_index(key, n);
1280 /* This bit of code is a bit tricky but it combines multiple
1281 * checks into a single check. The prefix consists of the
1282 * prefix plus zeros for the "bits" in the prefix. The index
1283 * is the difference between the key and this value. From
1284 * this we can actually derive several pieces of data.
1285 * if (index >= (1ul << bits))
1286 * we have a mismatch in skip bits and failed
1288 * we know the value is cindex
1290 * This check is safe even if bits == KEYLENGTH due to the
1291 * fact that we can only allocate a node with 32 bits if a
1292 * long is greater than 32 bits.
1294 if (index >= (1ul << n->bits))
1297 /* we have found a leaf. Prefixes have already been compared */
1301 /* only record pn and cindex if we are going to be chopping
1302 * bits later. Otherwise we are just wasting cycles.
1304 if (n->slen > n->pos) {
1309 n = get_child_rcu(n, index);
1314 /* Step 2: Sort out leaves and begin backtracing for longest prefix */
1316 /* record the pointer where our next node pointer is stored */
1317 struct key_vector __rcu **cptr = n->tnode;
1319 /* This test verifies that none of the bits that differ
1320 * between the key and the prefix exist in the region of
1321 * the lsb and higher in the prefix.
1323 if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos))
1326 /* exit out and process leaf */
1327 if (unlikely(IS_LEAF(n)))
1330 /* Don't bother recording parent info. Since we are in
1331 * prefix match mode we will have to come back to wherever
1332 * we started this traversal anyway
1335 while ((n = rcu_dereference(*cptr)) == NULL) {
1337 #ifdef CONFIG_IP_FIB_TRIE_STATS
1339 this_cpu_inc(stats->null_node_hit);
1341 /* If we are at cindex 0 there are no more bits for
1342 * us to strip at this level so we must ascend back
1343 * up one level to see if there are any more bits to
1344 * be stripped there.
1347 t_key pkey = pn->key;
1349 pn = node_parent_rcu(pn);
1352 #ifdef CONFIG_IP_FIB_TRIE_STATS
1353 this_cpu_inc(stats->backtrack);
1355 /* Get Child's index */
1356 cindex = get_index(pkey, pn);
1359 /* strip the least significant bit from the cindex */
1360 cindex &= cindex - 1;
1362 /* grab pointer for next child node */
1363 cptr = &pn->tnode[cindex];
1368 /* this line carries forward the xor from earlier in the function */
1369 index = key ^ n->key;
1371 /* Step 3: Process the leaf, if that fails fall back to backtracing */
1372 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
1373 struct fib_info *fi = fa->fa_info;
1376 if ((index >= (1ul << fa->fa_slen)) &&
1377 ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen != KEYLENGTH)))
1379 if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
1383 if (fa->fa_info->fib_scope < flp->flowi4_scope)
1385 fib_alias_accessed(fa);
1386 err = fib_props[fa->fa_type].error;
1387 if (unlikely(err < 0)) {
1388 #ifdef CONFIG_IP_FIB_TRIE_STATS
1389 this_cpu_inc(stats->semantic_match_passed);
1393 if (fi->fib_flags & RTNH_F_DEAD)
1395 for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) {
1396 const struct fib_nh *nh = &fi->fib_nh[nhsel];
1398 if (nh->nh_flags & RTNH_F_DEAD)
1400 if (flp->flowi4_oif && flp->flowi4_oif != nh->nh_oif)
1403 if (!(fib_flags & FIB_LOOKUP_NOREF))
1404 atomic_inc(&fi->fib_clntref);
1406 res->prefixlen = KEYLENGTH - fa->fa_slen;
1407 res->nh_sel = nhsel;
1408 res->type = fa->fa_type;
1409 res->scope = fi->fib_scope;
1412 res->fa_head = &n->leaf;
1413 #ifdef CONFIG_IP_FIB_TRIE_STATS
1414 this_cpu_inc(stats->semantic_match_passed);
1419 #ifdef CONFIG_IP_FIB_TRIE_STATS
1420 this_cpu_inc(stats->semantic_match_miss);
1424 EXPORT_SYMBOL_GPL(fib_table_lookup);
1426 static void fib_remove_alias(struct trie *t, struct key_vector *tp,
1427 struct key_vector *l, struct fib_alias *old)
1429 /* record the location of the previous list_info entry */
1430 struct hlist_node **pprev = old->fa_list.pprev;
1431 struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next);
1433 /* remove the fib_alias from the list */
1434 hlist_del_rcu(&old->fa_list);
1436 /* if we emptied the list this leaf will be freed and we can sort
1437 * out parent suffix lengths as a part of trie_rebalance
1439 if (hlist_empty(&l->leaf)) {
1440 put_child_root(tp, t, l->key, NULL);
1442 trie_rebalance(t, tp);
1446 /* only access fa if it is pointing at the last valid hlist_node */
1450 /* update the trie with the latest suffix length */
1451 l->slen = fa->fa_slen;
1452 leaf_pull_suffix(tp, l);
1455 /* Caller must hold RTNL. */
1456 int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
1458 struct trie *t = (struct trie *) tb->tb_data;
1459 struct fib_alias *fa, *fa_to_delete;
1460 struct key_vector *l, *tp;
1461 u8 plen = cfg->fc_dst_len;
1462 u8 slen = KEYLENGTH - plen;
1463 u8 tos = cfg->fc_tos;
1466 if (plen > KEYLENGTH)
1469 key = ntohl(cfg->fc_dst);
1471 if ((plen < KEYLENGTH) && (key << plen))
1474 l = fib_find_node(t, &tp, key);
1478 fa = fib_find_alias(&l->leaf, slen, tos, 0);
1482 pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
1484 fa_to_delete = NULL;
1485 hlist_for_each_entry_from(fa, fa_list) {
1486 struct fib_info *fi = fa->fa_info;
1488 if ((fa->fa_slen != slen) || (fa->fa_tos != tos))
1491 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
1492 (cfg->fc_scope == RT_SCOPE_NOWHERE ||
1493 fa->fa_info->fib_scope == cfg->fc_scope) &&
1494 (!cfg->fc_prefsrc ||
1495 fi->fib_prefsrc == cfg->fc_prefsrc) &&
1496 (!cfg->fc_protocol ||
1497 fi->fib_protocol == cfg->fc_protocol) &&
1498 fib_nh_match(cfg, fi) == 0) {
1507 netdev_switch_fib_ipv4_del(key, plen, fa_to_delete->fa_info, tos,
1508 cfg->fc_type, tb->tb_id);
1510 rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id,
1511 &cfg->fc_nlinfo, 0);
1514 tb->tb_num_default--;
1516 fib_remove_alias(t, tp, l, fa_to_delete);
1518 if (fa_to_delete->fa_state & FA_S_ACCESSED)
1519 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1521 fib_release_info(fa_to_delete->fa_info);
1522 alias_free_mem_rcu(fa_to_delete);
1526 /* Scan for the next leaf starting at the provided key value */
1527 static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key)
1529 struct key_vector *pn, *n = *tn;
1530 unsigned long cindex;
1532 /* record parent node for backtracing */
1534 cindex = n ? get_index(key, n) : 0;
1536 /* this loop is meant to try and find the key in the trie */
1538 unsigned long idx = get_index(key, n);
1540 /* guarantee forward progress on the keys */
1541 if (IS_LEAF(n) && (n->key >= key))
1543 if (idx >= (1ul << n->bits))
1546 /* record parent and next child index */
1550 /* descend into the next child */
1551 n = get_child_rcu(pn, cindex++);
1554 /* this loop will search for the next leaf with a greater key */
1556 /* if we exhausted the parent node we will need to climb */
1557 if (cindex >= (1ul << pn->bits)) {
1558 t_key pkey = pn->key;
1560 pn = node_parent_rcu(pn);
1564 cindex = get_index(pkey, pn) + 1;
1568 /* grab the next available node */
1569 n = get_child_rcu(pn, cindex++);
1573 /* no need to compare keys since we bumped the index */
1577 /* Rescan start scanning in new node */
1583 return NULL; /* Root of trie */
1585 /* if we are at the limit for keys just return NULL for the tnode */
1586 *tn = (n->key == KEY_MAX) ? NULL : pn;
1590 /* Caller must hold RTNL */
1591 void fib_table_flush_external(struct fib_table *tb)
1593 struct trie *t = (struct trie *)tb->tb_data;
1594 struct fib_alias *fa;
1595 struct key_vector *n, *pn;
1596 unsigned long cindex;
1598 n = rcu_dereference(t->tnode[0]);
1605 while (IS_TNODE(n)) {
1606 /* record pn and cindex for leaf walking */
1608 cindex = 1ul << n->bits;
1610 /* walk trie in reverse order */
1612 while (!(cindex--)) {
1613 t_key pkey = pn->key;
1615 /* if we got the root we are done */
1616 pn = node_parent(pn);
1620 cindex = get_index(pkey, pn);
1623 /* grab the next available node */
1624 n = get_child(pn, cindex);
1628 hlist_for_each_entry(fa, &n->leaf, fa_list) {
1629 struct fib_info *fi = fa->fa_info;
1631 if (!fi || !(fi->fib_flags & RTNH_F_EXTERNAL))
1634 netdev_switch_fib_ipv4_del(n->key,
1635 KEYLENGTH - fa->fa_slen,
1637 fa->fa_type, tb->tb_id);
1640 /* if trie is leaf only loop is completed */
1645 /* Caller must hold RTNL. */
1646 int fib_table_flush(struct fib_table *tb)
1648 struct trie *t = (struct trie *)tb->tb_data;
1649 struct key_vector *n, *pn;
1650 struct hlist_node *tmp;
1651 struct fib_alias *fa;
1652 unsigned long cindex;
1656 n = rcu_dereference(t->tnode[0]);
1658 goto flush_complete;
1663 while (IS_TNODE(n)) {
1664 /* record pn and cindex for leaf walking */
1666 cindex = 1ul << n->bits;
1668 /* walk trie in reverse order */
1670 while (!(cindex--)) {
1671 struct key_vector __rcu **cptr;
1672 t_key pkey = pn->key;
1675 pn = node_parent(n);
1677 /* resize completed node */
1678 cptr = resize(t, n);
1680 /* if we got the root we are done */
1682 goto flush_complete;
1684 pn = container_of(cptr, struct key_vector,
1686 cindex = get_index(pkey, pn);
1689 /* grab the next available node */
1690 n = get_child(pn, cindex);
1694 /* track slen in case any prefixes survive */
1697 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1698 struct fib_info *fi = fa->fa_info;
1700 if (fi && (fi->fib_flags & RTNH_F_DEAD)) {
1701 netdev_switch_fib_ipv4_del(n->key,
1702 KEYLENGTH - fa->fa_slen,
1704 fa->fa_type, tb->tb_id);
1705 hlist_del_rcu(&fa->fa_list);
1706 fib_release_info(fa->fa_info);
1707 alias_free_mem_rcu(fa);
1716 /* update leaf slen */
1719 if (hlist_empty(&n->leaf)) {
1720 put_child_root(pn, t, n->key, NULL);
1723 leaf_pull_suffix(pn, n);
1726 /* if trie is leaf only loop is completed */
1730 pr_debug("trie_flush found=%d\n", found);
1734 static void __trie_free_rcu(struct rcu_head *head)
1736 struct fib_table *tb = container_of(head, struct fib_table, rcu);
1737 #ifdef CONFIG_IP_FIB_TRIE_STATS
1738 struct trie *t = (struct trie *)tb->tb_data;
1740 free_percpu(t->stats);
1741 #endif /* CONFIG_IP_FIB_TRIE_STATS */
1745 void fib_free_table(struct fib_table *tb)
1747 call_rcu(&tb->rcu, __trie_free_rcu);
1750 static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb,
1751 struct sk_buff *skb, struct netlink_callback *cb)
1753 __be32 xkey = htonl(l->key);
1754 struct fib_alias *fa;
1760 /* rcu_read_lock is hold by caller */
1761 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
1767 if (fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
1773 KEYLENGTH - fa->fa_slen,
1775 fa->fa_info, NLM_F_MULTI) < 0) {
1786 /* rcu_read_lock needs to be hold by caller from readside */
1787 int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
1788 struct netlink_callback *cb)
1790 struct trie *t = (struct trie *)tb->tb_data;
1791 struct key_vector *l, *tp;
1792 /* Dump starting at last key.
1793 * Note: 0.0.0.0/0 (ie default) is first key.
1795 int count = cb->args[2];
1796 t_key key = cb->args[3];
1798 tp = rcu_dereference_rtnl(t->tnode[0]);
1800 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
1801 if (fn_trie_dump_leaf(l, tb, skb, cb) < 0) {
1803 cb->args[2] = count;
1810 memset(&cb->args[4], 0,
1811 sizeof(cb->args) - 4*sizeof(cb->args[0]));
1813 /* stop loop if key wrapped back to 0 */
1819 cb->args[2] = count;
1824 void __init fib_trie_init(void)
1826 fn_alias_kmem = kmem_cache_create("ip_fib_alias",
1827 sizeof(struct fib_alias),
1828 0, SLAB_PANIC, NULL);
1830 trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
1832 0, SLAB_PANIC, NULL);
1836 struct fib_table *fib_trie_table(u32 id)
1838 struct fib_table *tb;
1841 tb = kmalloc(sizeof(struct fib_table) + sizeof(struct trie),
1847 tb->tb_default = -1;
1848 tb->tb_num_default = 0;
1850 t = (struct trie *) tb->tb_data;
1851 RCU_INIT_POINTER(t->tnode[0], NULL);
1852 #ifdef CONFIG_IP_FIB_TRIE_STATS
1853 t->stats = alloc_percpu(struct trie_use_stats);
1863 #ifdef CONFIG_PROC_FS
1864 /* Depth first Trie walk iterator */
1865 struct fib_trie_iter {
1866 struct seq_net_private p;
1867 struct fib_table *tb;
1868 struct key_vector *tnode;
1873 static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter)
1875 unsigned long cindex = iter->index;
1876 struct key_vector *tn = iter->tnode;
1877 struct key_vector *p;
1879 /* A single entry routing table */
1883 pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
1884 iter->tnode, iter->index, iter->depth);
1886 while (cindex < child_length(tn)) {
1887 struct key_vector *n = get_child_rcu(tn, cindex);
1892 iter->index = cindex + 1;
1894 /* push down one level */
1905 /* Current node exhausted, pop back up */
1906 p = node_parent_rcu(tn);
1908 cindex = get_index(tn->key, p) + 1;
1918 static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter,
1921 struct key_vector *n;
1926 n = rcu_dereference(t->tnode[0]);
1943 static void trie_collect_stats(struct trie *t, struct trie_stat *s)
1945 struct key_vector *n;
1946 struct fib_trie_iter iter;
1948 memset(s, 0, sizeof(*s));
1951 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) {
1953 struct fib_alias *fa;
1956 s->totdepth += iter.depth;
1957 if (iter.depth > s->maxdepth)
1958 s->maxdepth = iter.depth;
1960 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list)
1964 if (n->bits < MAX_STAT_DEPTH)
1965 s->nodesizes[n->bits]++;
1966 s->nullpointers += n->empty_children;
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 = LEAF_SIZE * stat->leaves;
1991 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes);
1992 bytes += sizeof(struct fib_alias) * stat->prefixes;
1994 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);
1995 bytes += TNODE_SIZE(0) * 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 key_vector *) * 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 LEAF_SIZE, TNODE_SIZE(0));
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 key_vector *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) {
2115 struct key_vector *n;
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;
2144 struct key_vector *n;
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 key_vector *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 __be32 val = htonl(n->key);
2244 struct fib_alias *fa;
2246 seq_indent(seq, iter->depth);
2247 seq_printf(seq, " |-- %pI4\n", &val);
2249 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
2250 char buf1[32], buf2[32];
2252 seq_indent(seq, iter->depth + 1);
2253 seq_printf(seq, " /%zu %s %s",
2254 KEYLENGTH - fa->fa_slen,
2255 rtn_scope(buf1, sizeof(buf1),
2256 fa->fa_info->fib_scope),
2257 rtn_type(buf2, sizeof(buf2),
2260 seq_printf(seq, " tos=%d", fa->fa_tos);
2261 seq_putc(seq, '\n');
2268 static const struct seq_operations fib_trie_seq_ops = {
2269 .start = fib_trie_seq_start,
2270 .next = fib_trie_seq_next,
2271 .stop = fib_trie_seq_stop,
2272 .show = fib_trie_seq_show,
2275 static int fib_trie_seq_open(struct inode *inode, struct file *file)
2277 return seq_open_net(inode, file, &fib_trie_seq_ops,
2278 sizeof(struct fib_trie_iter));
2281 static const struct file_operations fib_trie_fops = {
2282 .owner = THIS_MODULE,
2283 .open = fib_trie_seq_open,
2285 .llseek = seq_lseek,
2286 .release = seq_release_net,
2289 struct fib_route_iter {
2290 struct seq_net_private p;
2291 struct fib_table *main_tb;
2292 struct key_vector *tnode;
2297 static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter,
2300 struct fib_table *tb = iter->main_tb;
2301 struct key_vector *l, **tp = &iter->tnode;
2305 /* use cache location of next-to-find key */
2306 if (iter->pos > 0 && pos >= iter->pos) {
2310 t = (struct trie *)tb->tb_data;
2311 iter->tnode = rcu_dereference_rtnl(t->tnode[0]);
2316 while ((l = leaf_walk_rcu(tp, key)) != NULL) {
2325 /* handle unlikely case of a key wrap */
2331 iter->key = key; /* remember it */
2333 iter->pos = 0; /* forget it */
2338 static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos)
2341 struct fib_route_iter *iter = seq->private;
2342 struct fib_table *tb;
2347 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
2354 return fib_route_get_idx(iter, *pos);
2356 t = (struct trie *)tb->tb_data;
2357 iter->tnode = rcu_dereference_rtnl(t->tnode[0]);
2361 return SEQ_START_TOKEN;
2364 static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2366 struct fib_route_iter *iter = seq->private;
2367 struct key_vector *l = NULL;
2368 t_key key = iter->key;
2372 /* only allow key of 0 for start of sequence */
2373 if ((v == SEQ_START_TOKEN) || key)
2374 l = leaf_walk_rcu(&iter->tnode, key);
2377 iter->key = l->key + 1;
2386 static void fib_route_seq_stop(struct seq_file *seq, void *v)
2392 static unsigned int fib_flag_trans(int type, __be32 mask, const struct fib_info *fi)
2394 unsigned int flags = 0;
2396 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT)
2398 if (fi && fi->fib_nh->nh_gw)
2399 flags |= RTF_GATEWAY;
2400 if (mask == htonl(0xFFFFFFFF))
2407 * This outputs /proc/net/route.
2408 * The format of the file is not supposed to be changed
2409 * and needs to be same as fib_hash output to avoid breaking
2412 static int fib_route_seq_show(struct seq_file *seq, void *v)
2414 struct fib_alias *fa;
2415 struct key_vector *l = v;
2418 if (v == SEQ_START_TOKEN) {
2419 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
2420 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
2425 prefix = htonl(l->key);
2427 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2428 const struct fib_info *fi = fa->fa_info;
2429 __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen);
2430 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);
2432 if ((fa->fa_type == RTN_BROADCAST) ||
2433 (fa->fa_type == RTN_MULTICAST))
2436 seq_setwidth(seq, 127);
2440 "%s\t%08X\t%08X\t%04X\t%d\t%u\t"
2441 "%d\t%08X\t%d\t%u\t%u",
2442 fi->fib_dev ? fi->fib_dev->name : "*",
2444 fi->fib_nh->nh_gw, flags, 0, 0,
2448 fi->fib_advmss + 40 : 0),
2453 "*\t%08X\t%08X\t%04X\t%d\t%u\t"
2454 "%d\t%08X\t%d\t%u\t%u",
2455 prefix, 0, flags, 0, 0, 0,
2464 static const struct seq_operations fib_route_seq_ops = {
2465 .start = fib_route_seq_start,
2466 .next = fib_route_seq_next,
2467 .stop = fib_route_seq_stop,
2468 .show = fib_route_seq_show,
2471 static int fib_route_seq_open(struct inode *inode, struct file *file)
2473 return seq_open_net(inode, file, &fib_route_seq_ops,
2474 sizeof(struct fib_route_iter));
2477 static const struct file_operations fib_route_fops = {
2478 .owner = THIS_MODULE,
2479 .open = fib_route_seq_open,
2481 .llseek = seq_lseek,
2482 .release = seq_release_net,
2485 int __net_init fib_proc_init(struct net *net)
2487 if (!proc_create("fib_trie", S_IRUGO, net->proc_net, &fib_trie_fops))
2490 if (!proc_create("fib_triestat", S_IRUGO, net->proc_net,
2491 &fib_triestat_fops))
2494 if (!proc_create("route", S_IRUGO, net->proc_net, &fib_route_fops))
2500 remove_proc_entry("fib_triestat", net->proc_net);
2502 remove_proc_entry("fib_trie", net->proc_net);
2507 void __net_exit fib_proc_exit(struct net *net)
2509 remove_proc_entry("fib_trie", net->proc_net);
2510 remove_proc_entry("fib_triestat", net->proc_net);
2511 remove_proc_entry("route", net->proc_net);
2514 #endif /* CONFIG_PROC_FS */