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 <linux/vmalloc.h>
76 #include <linux/notifier.h>
77 #include <net/net_namespace.h>
79 #include <net/protocol.h>
80 #include <net/route.h>
83 #include <net/ip_fib.h>
84 #include <net/switchdev.h>
85 #include <trace/events/fib.h>
86 #include "fib_lookup.h"
88 static BLOCKING_NOTIFIER_HEAD(fib_chain);
90 int register_fib_notifier(struct notifier_block *nb)
92 return blocking_notifier_chain_register(&fib_chain, nb);
94 EXPORT_SYMBOL(register_fib_notifier);
96 int unregister_fib_notifier(struct notifier_block *nb)
98 return blocking_notifier_chain_unregister(&fib_chain, nb);
100 EXPORT_SYMBOL(unregister_fib_notifier);
102 int call_fib_notifiers(struct net *net, enum fib_event_type event_type,
103 struct fib_notifier_info *info)
106 return blocking_notifier_call_chain(&fib_chain, event_type, info);
109 static int call_fib_entry_notifiers(struct net *net,
110 enum fib_event_type event_type, u32 dst,
111 int dst_len, struct fib_info *fi,
112 u8 tos, u8 type, u32 tb_id, u32 nlflags)
114 struct fib_entry_notifier_info info = {
123 return call_fib_notifiers(net, event_type, &info.info);
126 #define MAX_STAT_DEPTH 32
128 #define KEYLENGTH (8*sizeof(t_key))
129 #define KEY_MAX ((t_key)~0)
131 typedef unsigned int t_key;
133 #define IS_TRIE(n) ((n)->pos >= KEYLENGTH)
134 #define IS_TNODE(n) ((n)->bits)
135 #define IS_LEAF(n) (!(n)->bits)
139 unsigned char pos; /* 2log(KEYLENGTH) bits needed */
140 unsigned char bits; /* 2log(KEYLENGTH) bits needed */
143 /* This list pointer if valid if (pos | bits) == 0 (LEAF) */
144 struct hlist_head leaf;
145 /* This array is valid if (pos | bits) > 0 (TNODE) */
146 struct key_vector __rcu *tnode[0];
152 t_key empty_children; /* KEYLENGTH bits needed */
153 t_key full_children; /* KEYLENGTH bits needed */
154 struct key_vector __rcu *parent;
155 struct key_vector kv[1];
156 #define tn_bits kv[0].bits
159 #define TNODE_SIZE(n) offsetof(struct tnode, kv[0].tnode[n])
160 #define LEAF_SIZE TNODE_SIZE(1)
162 #ifdef CONFIG_IP_FIB_TRIE_STATS
163 struct trie_use_stats {
165 unsigned int backtrack;
166 unsigned int semantic_match_passed;
167 unsigned int semantic_match_miss;
168 unsigned int null_node_hit;
169 unsigned int resize_node_skipped;
174 unsigned int totdepth;
175 unsigned int maxdepth;
178 unsigned int nullpointers;
179 unsigned int prefixes;
180 unsigned int nodesizes[MAX_STAT_DEPTH];
184 struct key_vector kv[1];
185 #ifdef CONFIG_IP_FIB_TRIE_STATS
186 struct trie_use_stats __percpu *stats;
190 static struct key_vector *resize(struct trie *t, struct key_vector *tn);
191 static size_t tnode_free_size;
194 * synchronize_rcu after call_rcu for that many pages; it should be especially
195 * useful before resizing the root node with PREEMPT_NONE configs; the value was
196 * obtained experimentally, aiming to avoid visible slowdown.
198 static const int sync_pages = 128;
200 static struct kmem_cache *fn_alias_kmem __read_mostly;
201 static struct kmem_cache *trie_leaf_kmem __read_mostly;
203 static inline struct tnode *tn_info(struct key_vector *kv)
205 return container_of(kv, struct tnode, kv[0]);
208 /* caller must hold RTNL */
209 #define node_parent(tn) rtnl_dereference(tn_info(tn)->parent)
210 #define get_child(tn, i) rtnl_dereference((tn)->tnode[i])
212 /* caller must hold RCU read lock or RTNL */
213 #define node_parent_rcu(tn) rcu_dereference_rtnl(tn_info(tn)->parent)
214 #define get_child_rcu(tn, i) rcu_dereference_rtnl((tn)->tnode[i])
216 /* wrapper for rcu_assign_pointer */
217 static inline void node_set_parent(struct key_vector *n, struct key_vector *tp)
220 rcu_assign_pointer(tn_info(n)->parent, tp);
223 #define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER(tn_info(n)->parent, p)
225 /* This provides us with the number of children in this node, in the case of a
226 * leaf this will return 0 meaning none of the children are accessible.
228 static inline unsigned long child_length(const struct key_vector *tn)
230 return (1ul << tn->bits) & ~(1ul);
233 #define get_cindex(key, kv) (((key) ^ (kv)->key) >> (kv)->pos)
235 static inline unsigned long get_index(t_key key, struct key_vector *kv)
237 unsigned long index = key ^ kv->key;
239 if ((BITS_PER_LONG <= KEYLENGTH) && (KEYLENGTH == kv->pos))
242 return index >> kv->pos;
245 /* To understand this stuff, an understanding of keys and all their bits is
246 * necessary. Every node in the trie has a key associated with it, but not
247 * all of the bits in that key are significant.
249 * Consider a node 'n' and its parent 'tp'.
251 * If n is a leaf, every bit in its key is significant. Its presence is
252 * necessitated by path compression, since during a tree traversal (when
253 * searching for a leaf - unless we are doing an insertion) we will completely
254 * ignore all skipped bits we encounter. Thus we need to verify, at the end of
255 * a potentially successful search, that we have indeed been walking the
258 * Note that we can never "miss" the correct key in the tree if present by
259 * following the wrong path. Path compression ensures that segments of the key
260 * that are the same for all keys with a given prefix are skipped, but the
261 * skipped part *is* identical for each node in the subtrie below the skipped
262 * bit! trie_insert() in this implementation takes care of that.
264 * if n is an internal node - a 'tnode' here, the various parts of its key
265 * have many different meanings.
268 * _________________________________________________________________
269 * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
270 * -----------------------------------------------------------------
271 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
273 * _________________________________________________________________
274 * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
275 * -----------------------------------------------------------------
276 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
283 * First, let's just ignore the bits that come before the parent tp, that is
284 * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this
285 * point we do not use them for anything.
287 * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the
288 * index into the parent's child array. That is, they will be used to find
289 * 'n' among tp's children.
291 * The bits from (n->pos + n->bits) to (tp->pos - 1) - "S" - are skipped bits
294 * All the bits we have seen so far are significant to the node n. The rest
295 * of the bits are really not needed or indeed known in n->key.
297 * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into
298 * n's child array, and will of course be different for each child.
300 * The rest of the bits, from 0 to (n->pos -1) - "u" - are completely unknown
304 static const int halve_threshold = 25;
305 static const int inflate_threshold = 50;
306 static const int halve_threshold_root = 15;
307 static const int inflate_threshold_root = 30;
309 static void __alias_free_mem(struct rcu_head *head)
311 struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
312 kmem_cache_free(fn_alias_kmem, fa);
315 static inline void alias_free_mem_rcu(struct fib_alias *fa)
317 call_rcu(&fa->rcu, __alias_free_mem);
320 #define TNODE_KMALLOC_MAX \
321 ilog2((PAGE_SIZE - TNODE_SIZE(0)) / sizeof(struct key_vector *))
322 #define TNODE_VMALLOC_MAX \
323 ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *))
325 static void __node_free_rcu(struct rcu_head *head)
327 struct tnode *n = container_of(head, struct tnode, rcu);
330 kmem_cache_free(trie_leaf_kmem, n);
335 #define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu)
337 static struct tnode *tnode_alloc(int bits)
341 /* verify bits is within bounds */
342 if (bits > TNODE_VMALLOC_MAX)
345 /* determine size and verify it is non-zero and didn't overflow */
346 size = TNODE_SIZE(1ul << bits);
348 if (size <= PAGE_SIZE)
349 return kzalloc(size, GFP_KERNEL);
351 return vzalloc(size);
354 static inline void empty_child_inc(struct key_vector *n)
356 ++tn_info(n)->empty_children ? : ++tn_info(n)->full_children;
359 static inline void empty_child_dec(struct key_vector *n)
361 tn_info(n)->empty_children-- ? : tn_info(n)->full_children--;
364 static struct key_vector *leaf_new(t_key key, struct fib_alias *fa)
366 struct key_vector *l;
369 kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
373 /* initialize key vector */
378 l->slen = fa->fa_slen;
380 /* link leaf to fib alias */
381 INIT_HLIST_HEAD(&l->leaf);
382 hlist_add_head(&fa->fa_list, &l->leaf);
387 static struct key_vector *tnode_new(t_key key, int pos, int bits)
389 unsigned int shift = pos + bits;
390 struct key_vector *tn;
393 /* verify bits and pos their msb bits clear and values are valid */
394 BUG_ON(!bits || (shift > KEYLENGTH));
396 tnode = tnode_alloc(bits);
400 pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0),
401 sizeof(struct key_vector *) << bits);
403 if (bits == KEYLENGTH)
404 tnode->full_children = 1;
406 tnode->empty_children = 1ul << bits;
409 tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
417 /* Check whether a tnode 'n' is "full", i.e. it is an internal node
418 * and no bits are skipped. See discussion in dyntree paper p. 6
420 static inline int tnode_full(struct key_vector *tn, struct key_vector *n)
422 return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n);
425 /* Add a child at position i overwriting the old value.
426 * Update the value of full_children and empty_children.
428 static void put_child(struct key_vector *tn, unsigned long i,
429 struct key_vector *n)
431 struct key_vector *chi = get_child(tn, i);
434 BUG_ON(i >= child_length(tn));
436 /* update emptyChildren, overflow into fullChildren */
442 /* update fullChildren */
443 wasfull = tnode_full(tn, chi);
444 isfull = tnode_full(tn, n);
446 if (wasfull && !isfull)
447 tn_info(tn)->full_children--;
448 else if (!wasfull && isfull)
449 tn_info(tn)->full_children++;
451 if (n && (tn->slen < n->slen))
454 rcu_assign_pointer(tn->tnode[i], n);
457 static void update_children(struct key_vector *tn)
461 /* update all of the child parent pointers */
462 for (i = child_length(tn); i;) {
463 struct key_vector *inode = get_child(tn, --i);
468 /* Either update the children of a tnode that
469 * already belongs to us or update the child
470 * to point to ourselves.
472 if (node_parent(inode) == tn)
473 update_children(inode);
475 node_set_parent(inode, tn);
479 static inline void put_child_root(struct key_vector *tp, t_key key,
480 struct key_vector *n)
483 rcu_assign_pointer(tp->tnode[0], n);
485 put_child(tp, get_index(key, tp), n);
488 static inline void tnode_free_init(struct key_vector *tn)
490 tn_info(tn)->rcu.next = NULL;
493 static inline void tnode_free_append(struct key_vector *tn,
494 struct key_vector *n)
496 tn_info(n)->rcu.next = tn_info(tn)->rcu.next;
497 tn_info(tn)->rcu.next = &tn_info(n)->rcu;
500 static void tnode_free(struct key_vector *tn)
502 struct callback_head *head = &tn_info(tn)->rcu;
506 tnode_free_size += TNODE_SIZE(1ul << tn->bits);
509 tn = container_of(head, struct tnode, rcu)->kv;
512 if (tnode_free_size >= PAGE_SIZE * sync_pages) {
518 static struct key_vector *replace(struct trie *t,
519 struct key_vector *oldtnode,
520 struct key_vector *tn)
522 struct key_vector *tp = node_parent(oldtnode);
525 /* setup the parent pointer out of and back into this node */
526 NODE_INIT_PARENT(tn, tp);
527 put_child_root(tp, tn->key, tn);
529 /* update all of the child parent pointers */
532 /* all pointers should be clean so we are done */
533 tnode_free(oldtnode);
535 /* resize children now that oldtnode is freed */
536 for (i = child_length(tn); i;) {
537 struct key_vector *inode = get_child(tn, --i);
539 /* resize child node */
540 if (tnode_full(tn, inode))
541 tn = resize(t, inode);
547 static struct key_vector *inflate(struct trie *t,
548 struct key_vector *oldtnode)
550 struct key_vector *tn;
554 pr_debug("In inflate\n");
556 tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1);
560 /* prepare oldtnode to be freed */
561 tnode_free_init(oldtnode);
563 /* Assemble all of the pointers in our cluster, in this case that
564 * represents all of the pointers out of our allocated nodes that
565 * point to existing tnodes and the links between our allocated
568 for (i = child_length(oldtnode), m = 1u << tn->pos; i;) {
569 struct key_vector *inode = get_child(oldtnode, --i);
570 struct key_vector *node0, *node1;
577 /* A leaf or an internal node with skipped bits */
578 if (!tnode_full(oldtnode, inode)) {
579 put_child(tn, get_index(inode->key, tn), inode);
583 /* drop the node in the old tnode free list */
584 tnode_free_append(oldtnode, inode);
586 /* An internal node with two children */
587 if (inode->bits == 1) {
588 put_child(tn, 2 * i + 1, get_child(inode, 1));
589 put_child(tn, 2 * i, get_child(inode, 0));
593 /* We will replace this node 'inode' with two new
594 * ones, 'node0' and 'node1', each with half of the
595 * original children. The two new nodes will have
596 * a position one bit further down the key and this
597 * means that the "significant" part of their keys
598 * (see the discussion near the top of this file)
599 * will differ by one bit, which will be "0" in
600 * node0's key and "1" in node1's key. Since we are
601 * moving the key position by one step, the bit that
602 * we are moving away from - the bit at position
603 * (tn->pos) - is the one that will differ between
604 * node0 and node1. So... we synthesize that bit in the
607 node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1);
610 node0 = tnode_new(inode->key, inode->pos, inode->bits - 1);
612 tnode_free_append(tn, node1);
615 tnode_free_append(tn, node0);
617 /* populate child pointers in new nodes */
618 for (k = child_length(inode), j = k / 2; j;) {
619 put_child(node1, --j, get_child(inode, --k));
620 put_child(node0, j, get_child(inode, j));
621 put_child(node1, --j, get_child(inode, --k));
622 put_child(node0, j, get_child(inode, j));
625 /* link new nodes to parent */
626 NODE_INIT_PARENT(node1, tn);
627 NODE_INIT_PARENT(node0, tn);
629 /* link parent to nodes */
630 put_child(tn, 2 * i + 1, node1);
631 put_child(tn, 2 * i, node0);
634 /* setup the parent pointers into and out of this node */
635 return replace(t, oldtnode, tn);
637 /* all pointers should be clean so we are done */
643 static struct key_vector *halve(struct trie *t,
644 struct key_vector *oldtnode)
646 struct key_vector *tn;
649 pr_debug("In halve\n");
651 tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1);
655 /* prepare oldtnode to be freed */
656 tnode_free_init(oldtnode);
658 /* Assemble all of the pointers in our cluster, in this case that
659 * represents all of the pointers out of our allocated nodes that
660 * point to existing tnodes and the links between our allocated
663 for (i = child_length(oldtnode); i;) {
664 struct key_vector *node1 = get_child(oldtnode, --i);
665 struct key_vector *node0 = get_child(oldtnode, --i);
666 struct key_vector *inode;
668 /* At least one of the children is empty */
669 if (!node1 || !node0) {
670 put_child(tn, i / 2, node1 ? : node0);
674 /* Two nonempty children */
675 inode = tnode_new(node0->key, oldtnode->pos, 1);
678 tnode_free_append(tn, inode);
680 /* initialize pointers out of node */
681 put_child(inode, 1, node1);
682 put_child(inode, 0, node0);
683 NODE_INIT_PARENT(inode, tn);
685 /* link parent to node */
686 put_child(tn, i / 2, inode);
689 /* setup the parent pointers into and out of this node */
690 return replace(t, oldtnode, tn);
692 /* all pointers should be clean so we are done */
698 static struct key_vector *collapse(struct trie *t,
699 struct key_vector *oldtnode)
701 struct key_vector *n, *tp;
704 /* scan the tnode looking for that one child that might still exist */
705 for (n = NULL, i = child_length(oldtnode); !n && i;)
706 n = get_child(oldtnode, --i);
708 /* compress one level */
709 tp = node_parent(oldtnode);
710 put_child_root(tp, oldtnode->key, n);
711 node_set_parent(n, tp);
719 static unsigned char update_suffix(struct key_vector *tn)
721 unsigned char slen = tn->pos;
722 unsigned long stride, i;
724 /* search though the list of children looking for nodes that might
725 * have a suffix greater than the one we currently have. This is
726 * why we start with a stride of 2 since a stride of 1 would
727 * represent the nodes with suffix length equal to tn->pos
729 for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) {
730 struct key_vector *n = get_child(tn, i);
732 if (!n || (n->slen <= slen))
735 /* update stride and slen based on new value */
736 stride <<= (n->slen - slen);
740 /* if slen covers all but the last bit we can stop here
741 * there will be nothing longer than that since only node
742 * 0 and 1 << (bits - 1) could have that as their suffix
745 if ((slen + 1) >= (tn->pos + tn->bits))
754 /* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
755 * the Helsinki University of Technology and Matti Tikkanen of Nokia
756 * Telecommunications, page 6:
757 * "A node is doubled if the ratio of non-empty children to all
758 * children in the *doubled* node is at least 'high'."
760 * 'high' in this instance is the variable 'inflate_threshold'. It
761 * is expressed as a percentage, so we multiply it with
762 * child_length() and instead of multiplying by 2 (since the
763 * child array will be doubled by inflate()) and multiplying
764 * the left-hand side by 100 (to handle the percentage thing) we
765 * multiply the left-hand side by 50.
767 * The left-hand side may look a bit weird: child_length(tn)
768 * - tn->empty_children is of course the number of non-null children
769 * in the current node. tn->full_children is the number of "full"
770 * children, that is non-null tnodes with a skip value of 0.
771 * All of those will be doubled in the resulting inflated tnode, so
772 * we just count them one extra time here.
774 * A clearer way to write this would be:
776 * to_be_doubled = tn->full_children;
777 * not_to_be_doubled = child_length(tn) - tn->empty_children -
780 * new_child_length = child_length(tn) * 2;
782 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
784 * if (new_fill_factor >= inflate_threshold)
786 * ...and so on, tho it would mess up the while () loop.
789 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
793 * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
794 * inflate_threshold * new_child_length
796 * expand not_to_be_doubled and to_be_doubled, and shorten:
797 * 100 * (child_length(tn) - tn->empty_children +
798 * tn->full_children) >= inflate_threshold * new_child_length
800 * expand new_child_length:
801 * 100 * (child_length(tn) - tn->empty_children +
802 * tn->full_children) >=
803 * inflate_threshold * child_length(tn) * 2
806 * 50 * (tn->full_children + child_length(tn) -
807 * tn->empty_children) >= inflate_threshold *
811 static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn)
813 unsigned long used = child_length(tn);
814 unsigned long threshold = used;
816 /* Keep root node larger */
817 threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold;
818 used -= tn_info(tn)->empty_children;
819 used += tn_info(tn)->full_children;
821 /* if bits == KEYLENGTH then pos = 0, and will fail below */
823 return (used > 1) && tn->pos && ((50 * used) >= threshold);
826 static inline bool should_halve(struct key_vector *tp, struct key_vector *tn)
828 unsigned long used = child_length(tn);
829 unsigned long threshold = used;
831 /* Keep root node larger */
832 threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold;
833 used -= tn_info(tn)->empty_children;
835 /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */
837 return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold);
840 static inline bool should_collapse(struct key_vector *tn)
842 unsigned long used = child_length(tn);
844 used -= tn_info(tn)->empty_children;
846 /* account for bits == KEYLENGTH case */
847 if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children)
850 /* One child or none, time to drop us from the trie */
855 static struct key_vector *resize(struct trie *t, struct key_vector *tn)
857 #ifdef CONFIG_IP_FIB_TRIE_STATS
858 struct trie_use_stats __percpu *stats = t->stats;
860 struct key_vector *tp = node_parent(tn);
861 unsigned long cindex = get_index(tn->key, tp);
862 int max_work = MAX_WORK;
864 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
865 tn, inflate_threshold, halve_threshold);
867 /* track the tnode via the pointer from the parent instead of
868 * doing it ourselves. This way we can let RCU fully do its
869 * thing without us interfering
871 BUG_ON(tn != get_child(tp, cindex));
873 /* Double as long as the resulting node has a number of
874 * nonempty nodes that are above the threshold.
876 while (should_inflate(tp, tn) && max_work) {
879 #ifdef CONFIG_IP_FIB_TRIE_STATS
880 this_cpu_inc(stats->resize_node_skipped);
886 tn = get_child(tp, cindex);
889 /* update parent in case inflate failed */
890 tp = node_parent(tn);
892 /* Return if at least one inflate is run */
893 if (max_work != MAX_WORK)
896 /* Halve as long as the number of empty children in this
897 * node is above threshold.
899 while (should_halve(tp, tn) && max_work) {
902 #ifdef CONFIG_IP_FIB_TRIE_STATS
903 this_cpu_inc(stats->resize_node_skipped);
909 tn = get_child(tp, cindex);
912 /* Only one child remains */
913 if (should_collapse(tn))
914 return collapse(t, tn);
916 /* update parent in case halve failed */
917 tp = node_parent(tn);
919 /* Return if at least one deflate was run */
920 if (max_work != MAX_WORK)
923 /* push the suffix length to the parent node */
924 if (tn->slen > tn->pos) {
925 unsigned char slen = update_suffix(tn);
934 static void leaf_pull_suffix(struct key_vector *tp, struct key_vector *l)
936 while ((tp->slen > tp->pos) && (tp->slen > l->slen)) {
937 if (update_suffix(tp) > l->slen)
939 tp = node_parent(tp);
943 static void leaf_push_suffix(struct key_vector *tn, struct key_vector *l)
945 /* if this is a new leaf then tn will be NULL and we can sort
946 * out parent suffix lengths as a part of trie_rebalance
948 while (tn->slen < l->slen) {
950 tn = node_parent(tn);
954 /* rcu_read_lock needs to be hold by caller from readside */
955 static struct key_vector *fib_find_node(struct trie *t,
956 struct key_vector **tp, u32 key)
958 struct key_vector *pn, *n = t->kv;
959 unsigned long index = 0;
963 n = get_child_rcu(n, index);
968 index = get_cindex(key, n);
970 /* This bit of code is a bit tricky but it combines multiple
971 * checks into a single check. The prefix consists of the
972 * prefix plus zeros for the bits in the cindex. The index
973 * is the difference between the key and this value. From
974 * this we can actually derive several pieces of data.
975 * if (index >= (1ul << bits))
976 * we have a mismatch in skip bits and failed
978 * we know the value is cindex
980 * This check is safe even if bits == KEYLENGTH due to the
981 * fact that we can only allocate a node with 32 bits if a
982 * long is greater than 32 bits.
984 if (index >= (1ul << n->bits)) {
989 /* keep searching until we find a perfect match leaf or NULL */
990 } while (IS_TNODE(n));
997 /* Return the first fib alias matching TOS with
998 * priority less than or equal to PRIO.
1000 static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen,
1001 u8 tos, u32 prio, u32 tb_id)
1003 struct fib_alias *fa;
1008 hlist_for_each_entry(fa, fah, fa_list) {
1009 if (fa->fa_slen < slen)
1011 if (fa->fa_slen != slen)
1013 if (fa->tb_id > tb_id)
1015 if (fa->tb_id != tb_id)
1017 if (fa->fa_tos > tos)
1019 if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos)
1026 static void trie_rebalance(struct trie *t, struct key_vector *tn)
1028 while (!IS_TRIE(tn))
1032 static int fib_insert_node(struct trie *t, struct key_vector *tp,
1033 struct fib_alias *new, t_key key)
1035 struct key_vector *n, *l;
1037 l = leaf_new(key, new);
1041 /* retrieve child from parent node */
1042 n = get_child(tp, get_index(key, tp));
1044 /* Case 2: n is a LEAF or a TNODE and the key doesn't match.
1046 * Add a new tnode here
1047 * first tnode need some special handling
1048 * leaves us in position for handling as case 3
1051 struct key_vector *tn;
1053 tn = tnode_new(key, __fls(key ^ n->key), 1);
1057 /* initialize routes out of node */
1058 NODE_INIT_PARENT(tn, tp);
1059 put_child(tn, get_index(key, tn) ^ 1, n);
1061 /* start adding routes into the node */
1062 put_child_root(tp, key, tn);
1063 node_set_parent(n, tn);
1065 /* parent now has a NULL spot where the leaf can go */
1069 /* Case 3: n is NULL, and will just insert a new leaf */
1070 NODE_INIT_PARENT(l, tp);
1071 put_child_root(tp, key, l);
1072 trie_rebalance(t, tp);
1081 static int fib_insert_alias(struct trie *t, struct key_vector *tp,
1082 struct key_vector *l, struct fib_alias *new,
1083 struct fib_alias *fa, t_key key)
1086 return fib_insert_node(t, tp, new, key);
1089 hlist_add_before_rcu(&new->fa_list, &fa->fa_list);
1091 struct fib_alias *last;
1093 hlist_for_each_entry(last, &l->leaf, fa_list) {
1094 if (new->fa_slen < last->fa_slen)
1096 if ((new->fa_slen == last->fa_slen) &&
1097 (new->tb_id > last->tb_id))
1103 hlist_add_behind_rcu(&new->fa_list, &fa->fa_list);
1105 hlist_add_head_rcu(&new->fa_list, &l->leaf);
1108 /* if we added to the tail node then we need to update slen */
1109 if (l->slen < new->fa_slen) {
1110 l->slen = new->fa_slen;
1111 leaf_push_suffix(tp, l);
1117 /* Caller must hold RTNL. */
1118 int fib_table_insert(struct net *net, struct fib_table *tb,
1119 struct fib_config *cfg)
1121 struct trie *t = (struct trie *)tb->tb_data;
1122 struct fib_alias *fa, *new_fa;
1123 struct key_vector *l, *tp;
1124 u16 nlflags = NLM_F_EXCL;
1125 struct fib_info *fi;
1126 u8 plen = cfg->fc_dst_len;
1127 u8 slen = KEYLENGTH - plen;
1128 u8 tos = cfg->fc_tos;
1132 if (plen > KEYLENGTH)
1135 key = ntohl(cfg->fc_dst);
1137 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
1139 if ((plen < KEYLENGTH) && (key << plen))
1142 fi = fib_create_info(cfg);
1148 l = fib_find_node(t, &tp, key);
1149 fa = l ? fib_find_alias(&l->leaf, slen, tos, fi->fib_priority,
1152 /* Now fa, if non-NULL, points to the first fib alias
1153 * with the same keys [prefix,tos,priority], if such key already
1154 * exists or to the node before which we will insert new one.
1156 * If fa is NULL, we will need to allocate a new one and
1157 * insert to the tail of the section matching the suffix length
1161 if (fa && fa->fa_tos == tos &&
1162 fa->fa_info->fib_priority == fi->fib_priority) {
1163 struct fib_alias *fa_first, *fa_match;
1166 if (cfg->fc_nlflags & NLM_F_EXCL)
1169 nlflags &= ~NLM_F_EXCL;
1172 * 1. Find exact match for type, scope, fib_info to avoid
1174 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
1178 hlist_for_each_entry_from(fa, fa_list) {
1179 if ((fa->fa_slen != slen) ||
1180 (fa->tb_id != tb->tb_id) ||
1181 (fa->fa_tos != tos))
1183 if (fa->fa_info->fib_priority != fi->fib_priority)
1185 if (fa->fa_type == cfg->fc_type &&
1186 fa->fa_info == fi) {
1192 if (cfg->fc_nlflags & NLM_F_REPLACE) {
1193 struct fib_info *fi_drop;
1196 nlflags |= NLM_F_REPLACE;
1204 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1208 fi_drop = fa->fa_info;
1209 new_fa->fa_tos = fa->fa_tos;
1210 new_fa->fa_info = fi;
1211 new_fa->fa_type = cfg->fc_type;
1212 state = fa->fa_state;
1213 new_fa->fa_state = state & ~FA_S_ACCESSED;
1214 new_fa->fa_slen = fa->fa_slen;
1215 new_fa->tb_id = tb->tb_id;
1216 new_fa->fa_default = -1;
1218 err = switchdev_fib_ipv4_add(key, plen, fi,
1224 switchdev_fib_ipv4_abort(fi);
1225 kmem_cache_free(fn_alias_kmem, new_fa);
1229 hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list);
1231 alias_free_mem_rcu(fa);
1233 fib_release_info(fi_drop);
1234 if (state & FA_S_ACCESSED)
1235 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1237 call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_ADD,
1239 new_fa->fa_tos, cfg->fc_type,
1240 tb->tb_id, cfg->fc_nlflags);
1241 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
1242 tb->tb_id, &cfg->fc_nlinfo, nlflags);
1246 /* Error if we find a perfect match which
1247 * uses the same scope, type, and nexthop
1253 if (cfg->fc_nlflags & NLM_F_APPEND)
1254 nlflags |= NLM_F_APPEND;
1259 if (!(cfg->fc_nlflags & NLM_F_CREATE))
1262 nlflags |= NLM_F_CREATE;
1264 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1268 new_fa->fa_info = fi;
1269 new_fa->fa_tos = tos;
1270 new_fa->fa_type = cfg->fc_type;
1271 new_fa->fa_state = 0;
1272 new_fa->fa_slen = slen;
1273 new_fa->tb_id = tb->tb_id;
1274 new_fa->fa_default = -1;
1276 /* (Optionally) offload fib entry to switch hardware. */
1277 err = switchdev_fib_ipv4_add(key, plen, fi, tos, cfg->fc_type,
1278 cfg->fc_nlflags, tb->tb_id);
1280 switchdev_fib_ipv4_abort(fi);
1281 goto out_free_new_fa;
1284 /* Insert new entry to the list. */
1285 err = fib_insert_alias(t, tp, l, new_fa, fa, key);
1287 goto out_sw_fib_del;
1290 tb->tb_num_default++;
1292 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1293 call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_ADD, key, plen, fi, tos,
1294 cfg->fc_type, tb->tb_id, cfg->fc_nlflags);
1295 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id,
1296 &cfg->fc_nlinfo, nlflags);
1301 switchdev_fib_ipv4_del(key, plen, fi, tos, cfg->fc_type, tb->tb_id);
1303 kmem_cache_free(fn_alias_kmem, new_fa);
1305 fib_release_info(fi);
1310 static inline t_key prefix_mismatch(t_key key, struct key_vector *n)
1312 t_key prefix = n->key;
1314 return (key ^ prefix) & (prefix | -prefix);
1317 /* should be called with rcu_read_lock */
1318 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
1319 struct fib_result *res, int fib_flags)
1321 struct trie *t = (struct trie *) tb->tb_data;
1322 #ifdef CONFIG_IP_FIB_TRIE_STATS
1323 struct trie_use_stats __percpu *stats = t->stats;
1325 const t_key key = ntohl(flp->daddr);
1326 struct key_vector *n, *pn;
1327 struct fib_alias *fa;
1328 unsigned long index;
1331 trace_fib_table_lookup(tb->tb_id, flp);
1336 n = get_child_rcu(pn, cindex);
1340 #ifdef CONFIG_IP_FIB_TRIE_STATS
1341 this_cpu_inc(stats->gets);
1344 /* Step 1: Travel to the longest prefix match in the trie */
1346 index = get_cindex(key, n);
1348 /* This bit of code is a bit tricky but it combines multiple
1349 * checks into a single check. The prefix consists of the
1350 * prefix plus zeros for the "bits" in the prefix. The index
1351 * is the difference between the key and this value. From
1352 * this we can actually derive several pieces of data.
1353 * if (index >= (1ul << bits))
1354 * we have a mismatch in skip bits and failed
1356 * we know the value is cindex
1358 * This check is safe even if bits == KEYLENGTH due to the
1359 * fact that we can only allocate a node with 32 bits if a
1360 * long is greater than 32 bits.
1362 if (index >= (1ul << n->bits))
1365 /* we have found a leaf. Prefixes have already been compared */
1369 /* only record pn and cindex if we are going to be chopping
1370 * bits later. Otherwise we are just wasting cycles.
1372 if (n->slen > n->pos) {
1377 n = get_child_rcu(n, index);
1382 /* Step 2: Sort out leaves and begin backtracing for longest prefix */
1384 /* record the pointer where our next node pointer is stored */
1385 struct key_vector __rcu **cptr = n->tnode;
1387 /* This test verifies that none of the bits that differ
1388 * between the key and the prefix exist in the region of
1389 * the lsb and higher in the prefix.
1391 if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos))
1394 /* exit out and process leaf */
1395 if (unlikely(IS_LEAF(n)))
1398 /* Don't bother recording parent info. Since we are in
1399 * prefix match mode we will have to come back to wherever
1400 * we started this traversal anyway
1403 while ((n = rcu_dereference(*cptr)) == NULL) {
1405 #ifdef CONFIG_IP_FIB_TRIE_STATS
1407 this_cpu_inc(stats->null_node_hit);
1409 /* If we are at cindex 0 there are no more bits for
1410 * us to strip at this level so we must ascend back
1411 * up one level to see if there are any more bits to
1412 * be stripped there.
1415 t_key pkey = pn->key;
1417 /* If we don't have a parent then there is
1418 * nothing for us to do as we do not have any
1419 * further nodes to parse.
1423 #ifdef CONFIG_IP_FIB_TRIE_STATS
1424 this_cpu_inc(stats->backtrack);
1426 /* Get Child's index */
1427 pn = node_parent_rcu(pn);
1428 cindex = get_index(pkey, pn);
1431 /* strip the least significant bit from the cindex */
1432 cindex &= cindex - 1;
1434 /* grab pointer for next child node */
1435 cptr = &pn->tnode[cindex];
1440 /* this line carries forward the xor from earlier in the function */
1441 index = key ^ n->key;
1443 /* Step 3: Process the leaf, if that fails fall back to backtracing */
1444 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
1445 struct fib_info *fi = fa->fa_info;
1448 if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) {
1449 if (index >= (1ul << fa->fa_slen))
1452 if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
1456 if (fa->fa_info->fib_scope < flp->flowi4_scope)
1458 fib_alias_accessed(fa);
1459 err = fib_props[fa->fa_type].error;
1460 if (unlikely(err < 0)) {
1461 #ifdef CONFIG_IP_FIB_TRIE_STATS
1462 this_cpu_inc(stats->semantic_match_passed);
1466 if (fi->fib_flags & RTNH_F_DEAD)
1468 for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) {
1469 const struct fib_nh *nh = &fi->fib_nh[nhsel];
1470 struct in_device *in_dev = __in_dev_get_rcu(nh->nh_dev);
1472 if (nh->nh_flags & RTNH_F_DEAD)
1475 IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) &&
1476 nh->nh_flags & RTNH_F_LINKDOWN &&
1477 !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE))
1479 if (!(flp->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) {
1480 if (flp->flowi4_oif &&
1481 flp->flowi4_oif != nh->nh_oif)
1485 if (!(fib_flags & FIB_LOOKUP_NOREF))
1486 atomic_inc(&fi->fib_clntref);
1488 res->prefixlen = KEYLENGTH - fa->fa_slen;
1489 res->nh_sel = nhsel;
1490 res->type = fa->fa_type;
1491 res->scope = fi->fib_scope;
1494 res->fa_head = &n->leaf;
1495 #ifdef CONFIG_IP_FIB_TRIE_STATS
1496 this_cpu_inc(stats->semantic_match_passed);
1498 trace_fib_table_lookup_nh(nh);
1503 #ifdef CONFIG_IP_FIB_TRIE_STATS
1504 this_cpu_inc(stats->semantic_match_miss);
1508 EXPORT_SYMBOL_GPL(fib_table_lookup);
1510 static void fib_remove_alias(struct trie *t, struct key_vector *tp,
1511 struct key_vector *l, struct fib_alias *old)
1513 /* record the location of the previous list_info entry */
1514 struct hlist_node **pprev = old->fa_list.pprev;
1515 struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next);
1517 /* remove the fib_alias from the list */
1518 hlist_del_rcu(&old->fa_list);
1520 /* if we emptied the list this leaf will be freed and we can sort
1521 * out parent suffix lengths as a part of trie_rebalance
1523 if (hlist_empty(&l->leaf)) {
1524 put_child_root(tp, l->key, NULL);
1526 trie_rebalance(t, tp);
1530 /* only access fa if it is pointing at the last valid hlist_node */
1534 /* update the trie with the latest suffix length */
1535 l->slen = fa->fa_slen;
1536 leaf_pull_suffix(tp, l);
1539 /* Caller must hold RTNL. */
1540 int fib_table_delete(struct net *net, struct fib_table *tb,
1541 struct fib_config *cfg)
1543 struct trie *t = (struct trie *) tb->tb_data;
1544 struct fib_alias *fa, *fa_to_delete;
1545 struct key_vector *l, *tp;
1546 u8 plen = cfg->fc_dst_len;
1547 u8 slen = KEYLENGTH - plen;
1548 u8 tos = cfg->fc_tos;
1551 if (plen > KEYLENGTH)
1554 key = ntohl(cfg->fc_dst);
1556 if ((plen < KEYLENGTH) && (key << plen))
1559 l = fib_find_node(t, &tp, key);
1563 fa = fib_find_alias(&l->leaf, slen, tos, 0, tb->tb_id);
1567 pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
1569 fa_to_delete = NULL;
1570 hlist_for_each_entry_from(fa, fa_list) {
1571 struct fib_info *fi = fa->fa_info;
1573 if ((fa->fa_slen != slen) ||
1574 (fa->tb_id != tb->tb_id) ||
1575 (fa->fa_tos != tos))
1578 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
1579 (cfg->fc_scope == RT_SCOPE_NOWHERE ||
1580 fa->fa_info->fib_scope == cfg->fc_scope) &&
1581 (!cfg->fc_prefsrc ||
1582 fi->fib_prefsrc == cfg->fc_prefsrc) &&
1583 (!cfg->fc_protocol ||
1584 fi->fib_protocol == cfg->fc_protocol) &&
1585 fib_nh_match(cfg, fi) == 0) {
1594 switchdev_fib_ipv4_del(key, plen, fa_to_delete->fa_info, tos,
1595 cfg->fc_type, tb->tb_id);
1597 call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, key, plen,
1598 fa_to_delete->fa_info, tos, cfg->fc_type,
1600 rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id,
1601 &cfg->fc_nlinfo, 0);
1604 tb->tb_num_default--;
1606 fib_remove_alias(t, tp, l, fa_to_delete);
1608 if (fa_to_delete->fa_state & FA_S_ACCESSED)
1609 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1611 fib_release_info(fa_to_delete->fa_info);
1612 alias_free_mem_rcu(fa_to_delete);
1616 /* Scan for the next leaf starting at the provided key value */
1617 static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key)
1619 struct key_vector *pn, *n = *tn;
1620 unsigned long cindex;
1622 /* this loop is meant to try and find the key in the trie */
1624 /* record parent and next child index */
1626 cindex = (key > pn->key) ? get_index(key, pn) : 0;
1628 if (cindex >> pn->bits)
1631 /* descend into the next child */
1632 n = get_child_rcu(pn, cindex++);
1636 /* guarantee forward progress on the keys */
1637 if (IS_LEAF(n) && (n->key >= key))
1639 } while (IS_TNODE(n));
1641 /* this loop will search for the next leaf with a greater key */
1642 while (!IS_TRIE(pn)) {
1643 /* if we exhausted the parent node we will need to climb */
1644 if (cindex >= (1ul << pn->bits)) {
1645 t_key pkey = pn->key;
1647 pn = node_parent_rcu(pn);
1648 cindex = get_index(pkey, pn) + 1;
1652 /* grab the next available node */
1653 n = get_child_rcu(pn, cindex++);
1657 /* no need to compare keys since we bumped the index */
1661 /* Rescan start scanning in new node */
1667 return NULL; /* Root of trie */
1669 /* if we are at the limit for keys just return NULL for the tnode */
1674 static void fib_trie_free(struct fib_table *tb)
1676 struct trie *t = (struct trie *)tb->tb_data;
1677 struct key_vector *pn = t->kv;
1678 unsigned long cindex = 1;
1679 struct hlist_node *tmp;
1680 struct fib_alias *fa;
1682 /* walk trie in reverse order and free everything */
1684 struct key_vector *n;
1687 t_key pkey = pn->key;
1693 pn = node_parent(pn);
1695 /* drop emptied tnode */
1696 put_child_root(pn, n->key, NULL);
1699 cindex = get_index(pkey, pn);
1704 /* grab the next available node */
1705 n = get_child(pn, cindex);
1710 /* record pn and cindex for leaf walking */
1712 cindex = 1ul << n->bits;
1717 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1718 hlist_del_rcu(&fa->fa_list);
1719 alias_free_mem_rcu(fa);
1722 put_child_root(pn, n->key, NULL);
1726 #ifdef CONFIG_IP_FIB_TRIE_STATS
1727 free_percpu(t->stats);
1732 struct fib_table *fib_trie_unmerge(struct fib_table *oldtb)
1734 struct trie *ot = (struct trie *)oldtb->tb_data;
1735 struct key_vector *l, *tp = ot->kv;
1736 struct fib_table *local_tb;
1737 struct fib_alias *fa;
1741 if (oldtb->tb_data == oldtb->__data)
1744 local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL);
1748 lt = (struct trie *)local_tb->tb_data;
1750 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
1751 struct key_vector *local_l = NULL, *local_tp;
1753 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
1754 struct fib_alias *new_fa;
1756 if (local_tb->tb_id != fa->tb_id)
1759 /* clone fa for new local table */
1760 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1764 memcpy(new_fa, fa, sizeof(*fa));
1766 /* insert clone into table */
1768 local_l = fib_find_node(lt, &local_tp, l->key);
1770 if (fib_insert_alias(lt, local_tp, local_l, new_fa,
1775 /* stop loop if key wrapped back to 0 */
1783 fib_trie_free(local_tb);
1788 /* Caller must hold RTNL */
1789 void fib_table_flush_external(struct fib_table *tb)
1791 struct trie *t = (struct trie *)tb->tb_data;
1792 struct key_vector *pn = t->kv;
1793 unsigned long cindex = 1;
1794 struct hlist_node *tmp;
1795 struct fib_alias *fa;
1797 /* walk trie in reverse order */
1799 unsigned char slen = 0;
1800 struct key_vector *n;
1803 t_key pkey = pn->key;
1805 /* cannot resize the trie vector */
1809 /* resize completed node */
1811 cindex = get_index(pkey, pn);
1816 /* grab the next available node */
1817 n = get_child(pn, cindex);
1822 /* record pn and cindex for leaf walking */
1824 cindex = 1ul << n->bits;
1829 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1830 struct fib_info *fi = fa->fa_info;
1832 /* if alias was cloned to local then we just
1833 * need to remove the local copy from main
1835 if (tb->tb_id != fa->tb_id) {
1836 hlist_del_rcu(&fa->fa_list);
1837 alias_free_mem_rcu(fa);
1841 /* record local slen */
1844 if (!fi || !(fi->fib_flags & RTNH_F_OFFLOAD))
1847 switchdev_fib_ipv4_del(n->key, KEYLENGTH - fa->fa_slen,
1848 fi, fa->fa_tos, fa->fa_type,
1852 /* update leaf slen */
1855 if (hlist_empty(&n->leaf)) {
1856 put_child_root(pn, n->key, NULL);
1862 /* Caller must hold RTNL. */
1863 int fib_table_flush(struct net *net, struct fib_table *tb)
1865 struct trie *t = (struct trie *)tb->tb_data;
1866 struct key_vector *pn = t->kv;
1867 unsigned long cindex = 1;
1868 struct hlist_node *tmp;
1869 struct fib_alias *fa;
1872 /* walk trie in reverse order */
1874 unsigned char slen = 0;
1875 struct key_vector *n;
1878 t_key pkey = pn->key;
1880 /* cannot resize the trie vector */
1884 /* resize completed node */
1886 cindex = get_index(pkey, pn);
1891 /* grab the next available node */
1892 n = get_child(pn, cindex);
1897 /* record pn and cindex for leaf walking */
1899 cindex = 1ul << n->bits;
1904 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1905 struct fib_info *fi = fa->fa_info;
1907 if (!fi || !(fi->fib_flags & RTNH_F_DEAD)) {
1912 switchdev_fib_ipv4_del(n->key, KEYLENGTH - fa->fa_slen,
1913 fi, fa->fa_tos, fa->fa_type,
1915 call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL,
1917 KEYLENGTH - fa->fa_slen,
1918 fi, fa->fa_tos, fa->fa_type,
1920 hlist_del_rcu(&fa->fa_list);
1921 fib_release_info(fa->fa_info);
1922 alias_free_mem_rcu(fa);
1926 /* update leaf slen */
1929 if (hlist_empty(&n->leaf)) {
1930 put_child_root(pn, n->key, NULL);
1935 pr_debug("trie_flush found=%d\n", found);
1939 static void __trie_free_rcu(struct rcu_head *head)
1941 struct fib_table *tb = container_of(head, struct fib_table, rcu);
1942 #ifdef CONFIG_IP_FIB_TRIE_STATS
1943 struct trie *t = (struct trie *)tb->tb_data;
1945 if (tb->tb_data == tb->__data)
1946 free_percpu(t->stats);
1947 #endif /* CONFIG_IP_FIB_TRIE_STATS */
1951 void fib_free_table(struct fib_table *tb)
1953 call_rcu(&tb->rcu, __trie_free_rcu);
1956 static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb,
1957 struct sk_buff *skb, struct netlink_callback *cb)
1959 __be32 xkey = htonl(l->key);
1960 struct fib_alias *fa;
1966 /* rcu_read_lock is hold by caller */
1967 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
1973 if (tb->tb_id != fa->tb_id) {
1978 if (fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
1984 KEYLENGTH - fa->fa_slen,
1986 fa->fa_info, NLM_F_MULTI) < 0) {
1997 /* rcu_read_lock needs to be hold by caller from readside */
1998 int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
1999 struct netlink_callback *cb)
2001 struct trie *t = (struct trie *)tb->tb_data;
2002 struct key_vector *l, *tp = t->kv;
2003 /* Dump starting at last key.
2004 * Note: 0.0.0.0/0 (ie default) is first key.
2006 int count = cb->args[2];
2007 t_key key = cb->args[3];
2009 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
2010 if (fn_trie_dump_leaf(l, tb, skb, cb) < 0) {
2012 cb->args[2] = count;
2019 memset(&cb->args[4], 0,
2020 sizeof(cb->args) - 4*sizeof(cb->args[0]));
2022 /* stop loop if key wrapped back to 0 */
2028 cb->args[2] = count;
2033 void __init fib_trie_init(void)
2035 fn_alias_kmem = kmem_cache_create("ip_fib_alias",
2036 sizeof(struct fib_alias),
2037 0, SLAB_PANIC, NULL);
2039 trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
2041 0, SLAB_PANIC, NULL);
2044 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias)
2046 struct fib_table *tb;
2048 size_t sz = sizeof(*tb);
2051 sz += sizeof(struct trie);
2053 tb = kzalloc(sz, GFP_KERNEL);
2058 tb->tb_num_default = 0;
2059 tb->tb_data = (alias ? alias->__data : tb->__data);
2064 t = (struct trie *) tb->tb_data;
2065 t->kv[0].pos = KEYLENGTH;
2066 t->kv[0].slen = KEYLENGTH;
2067 #ifdef CONFIG_IP_FIB_TRIE_STATS
2068 t->stats = alloc_percpu(struct trie_use_stats);
2078 #ifdef CONFIG_PROC_FS
2079 /* Depth first Trie walk iterator */
2080 struct fib_trie_iter {
2081 struct seq_net_private p;
2082 struct fib_table *tb;
2083 struct key_vector *tnode;
2088 static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter)
2090 unsigned long cindex = iter->index;
2091 struct key_vector *pn = iter->tnode;
2094 pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
2095 iter->tnode, iter->index, iter->depth);
2097 while (!IS_TRIE(pn)) {
2098 while (cindex < child_length(pn)) {
2099 struct key_vector *n = get_child_rcu(pn, cindex++);
2106 iter->index = cindex;
2108 /* push down one level */
2117 /* Current node exhausted, pop back up */
2119 pn = node_parent_rcu(pn);
2120 cindex = get_index(pkey, pn) + 1;
2124 /* record root node so further searches know we are done */
2131 static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter,
2134 struct key_vector *n, *pn;
2140 n = rcu_dereference(pn->tnode[0]);
2157 static void trie_collect_stats(struct trie *t, struct trie_stat *s)
2159 struct key_vector *n;
2160 struct fib_trie_iter iter;
2162 memset(s, 0, sizeof(*s));
2165 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) {
2167 struct fib_alias *fa;
2170 s->totdepth += iter.depth;
2171 if (iter.depth > s->maxdepth)
2172 s->maxdepth = iter.depth;
2174 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list)
2178 if (n->bits < MAX_STAT_DEPTH)
2179 s->nodesizes[n->bits]++;
2180 s->nullpointers += tn_info(n)->empty_children;
2187 * This outputs /proc/net/fib_triestats
2189 static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
2191 unsigned int i, max, pointers, bytes, avdepth;
2194 avdepth = stat->totdepth*100 / stat->leaves;
2198 seq_printf(seq, "\tAver depth: %u.%02d\n",
2199 avdepth / 100, avdepth % 100);
2200 seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth);
2202 seq_printf(seq, "\tLeaves: %u\n", stat->leaves);
2203 bytes = LEAF_SIZE * stat->leaves;
2205 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes);
2206 bytes += sizeof(struct fib_alias) * stat->prefixes;
2208 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);
2209 bytes += TNODE_SIZE(0) * stat->tnodes;
2211 max = MAX_STAT_DEPTH;
2212 while (max > 0 && stat->nodesizes[max-1] == 0)
2216 for (i = 1; i < max; i++)
2217 if (stat->nodesizes[i] != 0) {
2218 seq_printf(seq, " %u: %u", i, stat->nodesizes[i]);
2219 pointers += (1<<i) * stat->nodesizes[i];
2221 seq_putc(seq, '\n');
2222 seq_printf(seq, "\tPointers: %u\n", pointers);
2224 bytes += sizeof(struct key_vector *) * pointers;
2225 seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers);
2226 seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024);
2229 #ifdef CONFIG_IP_FIB_TRIE_STATS
2230 static void trie_show_usage(struct seq_file *seq,
2231 const struct trie_use_stats __percpu *stats)
2233 struct trie_use_stats s = { 0 };
2236 /* loop through all of the CPUs and gather up the stats */
2237 for_each_possible_cpu(cpu) {
2238 const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu);
2240 s.gets += pcpu->gets;
2241 s.backtrack += pcpu->backtrack;
2242 s.semantic_match_passed += pcpu->semantic_match_passed;
2243 s.semantic_match_miss += pcpu->semantic_match_miss;
2244 s.null_node_hit += pcpu->null_node_hit;
2245 s.resize_node_skipped += pcpu->resize_node_skipped;
2248 seq_printf(seq, "\nCounters:\n---------\n");
2249 seq_printf(seq, "gets = %u\n", s.gets);
2250 seq_printf(seq, "backtracks = %u\n", s.backtrack);
2251 seq_printf(seq, "semantic match passed = %u\n",
2252 s.semantic_match_passed);
2253 seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss);
2254 seq_printf(seq, "null node hit= %u\n", s.null_node_hit);
2255 seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped);
2257 #endif /* CONFIG_IP_FIB_TRIE_STATS */
2259 static void fib_table_print(struct seq_file *seq, struct fib_table *tb)
2261 if (tb->tb_id == RT_TABLE_LOCAL)
2262 seq_puts(seq, "Local:\n");
2263 else if (tb->tb_id == RT_TABLE_MAIN)
2264 seq_puts(seq, "Main:\n");
2266 seq_printf(seq, "Id %d:\n", tb->tb_id);
2270 static int fib_triestat_seq_show(struct seq_file *seq, void *v)
2272 struct net *net = (struct net *)seq->private;
2276 "Basic info: size of leaf:"
2277 " %Zd bytes, size of tnode: %Zd bytes.\n",
2278 LEAF_SIZE, TNODE_SIZE(0));
2280 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2281 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2282 struct fib_table *tb;
2284 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2285 struct trie *t = (struct trie *) tb->tb_data;
2286 struct trie_stat stat;
2291 fib_table_print(seq, tb);
2293 trie_collect_stats(t, &stat);
2294 trie_show_stats(seq, &stat);
2295 #ifdef CONFIG_IP_FIB_TRIE_STATS
2296 trie_show_usage(seq, t->stats);
2304 static int fib_triestat_seq_open(struct inode *inode, struct file *file)
2306 return single_open_net(inode, file, fib_triestat_seq_show);
2309 static const struct file_operations fib_triestat_fops = {
2310 .owner = THIS_MODULE,
2311 .open = fib_triestat_seq_open,
2313 .llseek = seq_lseek,
2314 .release = single_release_net,
2317 static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos)
2319 struct fib_trie_iter *iter = seq->private;
2320 struct net *net = seq_file_net(seq);
2324 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2325 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2326 struct fib_table *tb;
2328 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2329 struct key_vector *n;
2331 for (n = fib_trie_get_first(iter,
2332 (struct trie *) tb->tb_data);
2333 n; n = fib_trie_get_next(iter))
2344 static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
2348 return fib_trie_get_idx(seq, *pos);
2351 static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2353 struct fib_trie_iter *iter = seq->private;
2354 struct net *net = seq_file_net(seq);
2355 struct fib_table *tb = iter->tb;
2356 struct hlist_node *tb_node;
2358 struct key_vector *n;
2361 /* next node in same table */
2362 n = fib_trie_get_next(iter);
2366 /* walk rest of this hash chain */
2367 h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);
2368 while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) {
2369 tb = hlist_entry(tb_node, struct fib_table, tb_hlist);
2370 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2375 /* new hash chain */
2376 while (++h < FIB_TABLE_HASHSZ) {
2377 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2378 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2379 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2391 static void fib_trie_seq_stop(struct seq_file *seq, void *v)
2397 static void seq_indent(struct seq_file *seq, int n)
2403 static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
2406 case RT_SCOPE_UNIVERSE: return "universe";
2407 case RT_SCOPE_SITE: return "site";
2408 case RT_SCOPE_LINK: return "link";
2409 case RT_SCOPE_HOST: return "host";
2410 case RT_SCOPE_NOWHERE: return "nowhere";
2412 snprintf(buf, len, "scope=%d", s);
2417 static const char *const rtn_type_names[__RTN_MAX] = {
2418 [RTN_UNSPEC] = "UNSPEC",
2419 [RTN_UNICAST] = "UNICAST",
2420 [RTN_LOCAL] = "LOCAL",
2421 [RTN_BROADCAST] = "BROADCAST",
2422 [RTN_ANYCAST] = "ANYCAST",
2423 [RTN_MULTICAST] = "MULTICAST",
2424 [RTN_BLACKHOLE] = "BLACKHOLE",
2425 [RTN_UNREACHABLE] = "UNREACHABLE",
2426 [RTN_PROHIBIT] = "PROHIBIT",
2427 [RTN_THROW] = "THROW",
2429 [RTN_XRESOLVE] = "XRESOLVE",
2432 static inline const char *rtn_type(char *buf, size_t len, unsigned int t)
2434 if (t < __RTN_MAX && rtn_type_names[t])
2435 return rtn_type_names[t];
2436 snprintf(buf, len, "type %u", t);
2440 /* Pretty print the trie */
2441 static int fib_trie_seq_show(struct seq_file *seq, void *v)
2443 const struct fib_trie_iter *iter = seq->private;
2444 struct key_vector *n = v;
2446 if (IS_TRIE(node_parent_rcu(n)))
2447 fib_table_print(seq, iter->tb);
2450 __be32 prf = htonl(n->key);
2452 seq_indent(seq, iter->depth-1);
2453 seq_printf(seq, " +-- %pI4/%zu %u %u %u\n",
2454 &prf, KEYLENGTH - n->pos - n->bits, n->bits,
2455 tn_info(n)->full_children,
2456 tn_info(n)->empty_children);
2458 __be32 val = htonl(n->key);
2459 struct fib_alias *fa;
2461 seq_indent(seq, iter->depth);
2462 seq_printf(seq, " |-- %pI4\n", &val);
2464 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
2465 char buf1[32], buf2[32];
2467 seq_indent(seq, iter->depth + 1);
2468 seq_printf(seq, " /%zu %s %s",
2469 KEYLENGTH - fa->fa_slen,
2470 rtn_scope(buf1, sizeof(buf1),
2471 fa->fa_info->fib_scope),
2472 rtn_type(buf2, sizeof(buf2),
2475 seq_printf(seq, " tos=%d", fa->fa_tos);
2476 seq_putc(seq, '\n');
2483 static const struct seq_operations fib_trie_seq_ops = {
2484 .start = fib_trie_seq_start,
2485 .next = fib_trie_seq_next,
2486 .stop = fib_trie_seq_stop,
2487 .show = fib_trie_seq_show,
2490 static int fib_trie_seq_open(struct inode *inode, struct file *file)
2492 return seq_open_net(inode, file, &fib_trie_seq_ops,
2493 sizeof(struct fib_trie_iter));
2496 static const struct file_operations fib_trie_fops = {
2497 .owner = THIS_MODULE,
2498 .open = fib_trie_seq_open,
2500 .llseek = seq_lseek,
2501 .release = seq_release_net,
2504 struct fib_route_iter {
2505 struct seq_net_private p;
2506 struct fib_table *main_tb;
2507 struct key_vector *tnode;
2512 static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter,
2515 struct key_vector *l, **tp = &iter->tnode;
2518 /* use cache location of next-to-find key */
2519 if (iter->pos > 0 && pos >= iter->pos) {
2527 while ((l = leaf_walk_rcu(tp, key)) != NULL) {
2536 /* handle unlikely case of a key wrap */
2542 iter->key = key; /* remember it */
2544 iter->pos = 0; /* forget it */
2549 static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos)
2552 struct fib_route_iter *iter = seq->private;
2553 struct fib_table *tb;
2558 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
2563 t = (struct trie *)tb->tb_data;
2564 iter->tnode = t->kv;
2567 return fib_route_get_idx(iter, *pos);
2572 return SEQ_START_TOKEN;
2575 static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2577 struct fib_route_iter *iter = seq->private;
2578 struct key_vector *l = NULL;
2579 t_key key = iter->key;
2583 /* only allow key of 0 for start of sequence */
2584 if ((v == SEQ_START_TOKEN) || key)
2585 l = leaf_walk_rcu(&iter->tnode, key);
2588 iter->key = l->key + 1;
2597 static void fib_route_seq_stop(struct seq_file *seq, void *v)
2603 static unsigned int fib_flag_trans(int type, __be32 mask, const struct fib_info *fi)
2605 unsigned int flags = 0;
2607 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT)
2609 if (fi && fi->fib_nh->nh_gw)
2610 flags |= RTF_GATEWAY;
2611 if (mask == htonl(0xFFFFFFFF))
2618 * This outputs /proc/net/route.
2619 * The format of the file is not supposed to be changed
2620 * and needs to be same as fib_hash output to avoid breaking
2623 static int fib_route_seq_show(struct seq_file *seq, void *v)
2625 struct fib_route_iter *iter = seq->private;
2626 struct fib_table *tb = iter->main_tb;
2627 struct fib_alias *fa;
2628 struct key_vector *l = v;
2631 if (v == SEQ_START_TOKEN) {
2632 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
2633 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
2638 prefix = htonl(l->key);
2640 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2641 const struct fib_info *fi = fa->fa_info;
2642 __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen);
2643 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);
2645 if ((fa->fa_type == RTN_BROADCAST) ||
2646 (fa->fa_type == RTN_MULTICAST))
2649 if (fa->tb_id != tb->tb_id)
2652 seq_setwidth(seq, 127);
2656 "%s\t%08X\t%08X\t%04X\t%d\t%u\t"
2657 "%d\t%08X\t%d\t%u\t%u",
2658 fi->fib_dev ? fi->fib_dev->name : "*",
2660 fi->fib_nh->nh_gw, flags, 0, 0,
2664 fi->fib_advmss + 40 : 0),
2669 "*\t%08X\t%08X\t%04X\t%d\t%u\t"
2670 "%d\t%08X\t%d\t%u\t%u",
2671 prefix, 0, flags, 0, 0, 0,
2680 static const struct seq_operations fib_route_seq_ops = {
2681 .start = fib_route_seq_start,
2682 .next = fib_route_seq_next,
2683 .stop = fib_route_seq_stop,
2684 .show = fib_route_seq_show,
2687 static int fib_route_seq_open(struct inode *inode, struct file *file)
2689 return seq_open_net(inode, file, &fib_route_seq_ops,
2690 sizeof(struct fib_route_iter));
2693 static const struct file_operations fib_route_fops = {
2694 .owner = THIS_MODULE,
2695 .open = fib_route_seq_open,
2697 .llseek = seq_lseek,
2698 .release = seq_release_net,
2701 int __net_init fib_proc_init(struct net *net)
2703 if (!proc_create("fib_trie", S_IRUGO, net->proc_net, &fib_trie_fops))
2706 if (!proc_create("fib_triestat", S_IRUGO, net->proc_net,
2707 &fib_triestat_fops))
2710 if (!proc_create("route", S_IRUGO, net->proc_net, &fib_route_fops))
2716 remove_proc_entry("fib_triestat", net->proc_net);
2718 remove_proc_entry("fib_trie", net->proc_net);
2723 void __net_exit fib_proc_exit(struct net *net)
2725 remove_proc_entry("fib_trie", net->proc_net);
2726 remove_proc_entry("fib_triestat", net->proc_net);
2727 remove_proc_entry("route", net->proc_net);
2730 #endif /* CONFIG_PROC_FS */