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1/*
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.
6 *
7 * Robert Olsson <robert.olsson@its.uu.se> Uppsala Universitet
8 * & Swedish University of Agricultural Sciences.
9 *
10 * Jens Laas <jens.laas@data.slu.se> Swedish University of
11 * Agricultural Sciences.
12 *
13 * Hans Liss <hans.liss@its.uu.se> Uppsala Universitet
14 *
15 * This work is based on the LPC-trie which is originally described in:
16 *
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/
20 *
21 *
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
24 *
25 *
26 * Code from fib_hash has been reused which includes the following header:
27 *
28 *
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.
32 *
33 * IPv4 FIB: lookup engine and maintenance routines.
34 *
35 *
36 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
37 *
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.
42 *
43 * Substantial contributions to this work comes from:
44 *
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>
49 */
50
51#define VERSION "0.409"
52
53#include <linux/cache.h>
54#include <linux/uaccess.h>
55#include <linux/bitops.h>
56#include <linux/types.h>
57#include <linux/kernel.h>
58#include <linux/mm.h>
59#include <linux/string.h>
60#include <linux/socket.h>
61#include <linux/sockios.h>
62#include <linux/errno.h>
63#include <linux/in.h>
64#include <linux/inet.h>
65#include <linux/inetdevice.h>
66#include <linux/netdevice.h>
67#include <linux/if_arp.h>
68#include <linux/proc_fs.h>
69#include <linux/rcupdate.h>
70#include <linux/skbuff.h>
71#include <linux/netlink.h>
72#include <linux/init.h>
73#include <linux/list.h>
74#include <linux/slab.h>
75#include <linux/export.h>
76#include <linux/vmalloc.h>
77#include <linux/notifier.h>
78#include <net/net_namespace.h>
79#include <net/ip.h>
80#include <net/protocol.h>
81#include <net/route.h>
82#include <net/tcp.h>
83#include <net/sock.h>
84#include <net/ip_fib.h>
85#include <net/fib_notifier.h>
86#include <trace/events/fib.h>
87#include "fib_lookup.h"
88
89static int call_fib_entry_notifier(struct notifier_block *nb, struct net *net,
90 enum fib_event_type event_type, u32 dst,
91 int dst_len, struct fib_alias *fa)
92{
93 struct fib_entry_notifier_info info = {
94 .dst = dst,
95 .dst_len = dst_len,
96 .fi = fa->fa_info,
97 .tos = fa->fa_tos,
98 .type = fa->fa_type,
99 .tb_id = fa->tb_id,
100 };
101 return call_fib4_notifier(nb, net, event_type, &info.info);
102}
103
104static int call_fib_entry_notifiers(struct net *net,
105 enum fib_event_type event_type, u32 dst,
106 int dst_len, struct fib_alias *fa,
107 struct netlink_ext_ack *extack)
108{
109 struct fib_entry_notifier_info info = {
110 .info.extack = extack,
111 .dst = dst,
112 .dst_len = dst_len,
113 .fi = fa->fa_info,
114 .tos = fa->fa_tos,
115 .type = fa->fa_type,
116 .tb_id = fa->tb_id,
117 };
118 return call_fib4_notifiers(net, event_type, &info.info);
119}
120
121#define MAX_STAT_DEPTH 32
122
123#define KEYLENGTH (8*sizeof(t_key))
124#define KEY_MAX ((t_key)~0)
125
126typedef unsigned int t_key;
127
128#define IS_TRIE(n) ((n)->pos >= KEYLENGTH)
129#define IS_TNODE(n) ((n)->bits)
130#define IS_LEAF(n) (!(n)->bits)
131
132struct key_vector {
133 t_key key;
134 unsigned char pos; /* 2log(KEYLENGTH) bits needed */
135 unsigned char bits; /* 2log(KEYLENGTH) bits needed */
136 unsigned char slen;
137 union {
138 /* This list pointer if valid if (pos | bits) == 0 (LEAF) */
139 struct hlist_head leaf;
140 /* This array is valid if (pos | bits) > 0 (TNODE) */
141 struct key_vector __rcu *tnode[0];
142 };
143};
144
145struct tnode {
146 struct rcu_head rcu;
147 t_key empty_children; /* KEYLENGTH bits needed */
148 t_key full_children; /* KEYLENGTH bits needed */
149 struct key_vector __rcu *parent;
150 struct key_vector kv[1];
151#define tn_bits kv[0].bits
152};
153
154#define TNODE_SIZE(n) offsetof(struct tnode, kv[0].tnode[n])
155#define LEAF_SIZE TNODE_SIZE(1)
156
157#ifdef CONFIG_IP_FIB_TRIE_STATS
158struct trie_use_stats {
159 unsigned int gets;
160 unsigned int backtrack;
161 unsigned int semantic_match_passed;
162 unsigned int semantic_match_miss;
163 unsigned int null_node_hit;
164 unsigned int resize_node_skipped;
165};
166#endif
167
168struct trie_stat {
169 unsigned int totdepth;
170 unsigned int maxdepth;
171 unsigned int tnodes;
172 unsigned int leaves;
173 unsigned int nullpointers;
174 unsigned int prefixes;
175 unsigned int nodesizes[MAX_STAT_DEPTH];
176};
177
178struct trie {
179 struct key_vector kv[1];
180#ifdef CONFIG_IP_FIB_TRIE_STATS
181 struct trie_use_stats __percpu *stats;
182#endif
183};
184
185static struct key_vector *resize(struct trie *t, struct key_vector *tn);
186static size_t tnode_free_size;
187
188/*
189 * synchronize_rcu after call_rcu for that many pages; it should be especially
190 * useful before resizing the root node with PREEMPT_NONE configs; the value was
191 * obtained experimentally, aiming to avoid visible slowdown.
192 */
193static const int sync_pages = 128;
194
195static struct kmem_cache *fn_alias_kmem __ro_after_init;
196static struct kmem_cache *trie_leaf_kmem __ro_after_init;
197
198static inline struct tnode *tn_info(struct key_vector *kv)
199{
200 return container_of(kv, struct tnode, kv[0]);
201}
202
203/* caller must hold RTNL */
204#define node_parent(tn) rtnl_dereference(tn_info(tn)->parent)
205#define get_child(tn, i) rtnl_dereference((tn)->tnode[i])
206
207/* caller must hold RCU read lock or RTNL */
208#define node_parent_rcu(tn) rcu_dereference_rtnl(tn_info(tn)->parent)
209#define get_child_rcu(tn, i) rcu_dereference_rtnl((tn)->tnode[i])
210
211/* wrapper for rcu_assign_pointer */
212static inline void node_set_parent(struct key_vector *n, struct key_vector *tp)
213{
214 if (n)
215 rcu_assign_pointer(tn_info(n)->parent, tp);
216}
217
218#define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER(tn_info(n)->parent, p)
219
220/* This provides us with the number of children in this node, in the case of a
221 * leaf this will return 0 meaning none of the children are accessible.
222 */
223static inline unsigned long child_length(const struct key_vector *tn)
224{
225 return (1ul << tn->bits) & ~(1ul);
226}
227
228#define get_cindex(key, kv) (((key) ^ (kv)->key) >> (kv)->pos)
229
230static inline unsigned long get_index(t_key key, struct key_vector *kv)
231{
232 unsigned long index = key ^ kv->key;
233
234 if ((BITS_PER_LONG <= KEYLENGTH) && (KEYLENGTH == kv->pos))
235 return 0;
236
237 return index >> kv->pos;
238}
239
240/* To understand this stuff, an understanding of keys and all their bits is
241 * necessary. Every node in the trie has a key associated with it, but not
242 * all of the bits in that key are significant.
243 *
244 * Consider a node 'n' and its parent 'tp'.
245 *
246 * If n is a leaf, every bit in its key is significant. Its presence is
247 * necessitated by path compression, since during a tree traversal (when
248 * searching for a leaf - unless we are doing an insertion) we will completely
249 * ignore all skipped bits we encounter. Thus we need to verify, at the end of
250 * a potentially successful search, that we have indeed been walking the
251 * correct key path.
252 *
253 * Note that we can never "miss" the correct key in the tree if present by
254 * following the wrong path. Path compression ensures that segments of the key
255 * that are the same for all keys with a given prefix are skipped, but the
256 * skipped part *is* identical for each node in the subtrie below the skipped
257 * bit! trie_insert() in this implementation takes care of that.
258 *
259 * if n is an internal node - a 'tnode' here, the various parts of its key
260 * have many different meanings.
261 *
262 * Example:
263 * _________________________________________________________________
264 * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
265 * -----------------------------------------------------------------
266 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
267 *
268 * _________________________________________________________________
269 * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
270 * -----------------------------------------------------------------
271 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
272 *
273 * tp->pos = 22
274 * tp->bits = 3
275 * n->pos = 13
276 * n->bits = 4
277 *
278 * First, let's just ignore the bits that come before the parent tp, that is
279 * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this
280 * point we do not use them for anything.
281 *
282 * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the
283 * index into the parent's child array. That is, they will be used to find
284 * 'n' among tp's children.
285 *
286 * The bits from (n->pos + n->bits) to (tp->pos - 1) - "S" - are skipped bits
287 * for the node n.
288 *
289 * All the bits we have seen so far are significant to the node n. The rest
290 * of the bits are really not needed or indeed known in n->key.
291 *
292 * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into
293 * n's child array, and will of course be different for each child.
294 *
295 * The rest of the bits, from 0 to (n->pos -1) - "u" - are completely unknown
296 * at this point.
297 */
298
299static const int halve_threshold = 25;
300static const int inflate_threshold = 50;
301static const int halve_threshold_root = 15;
302static const int inflate_threshold_root = 30;
303
304static void __alias_free_mem(struct rcu_head *head)
305{
306 struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
307 kmem_cache_free(fn_alias_kmem, fa);
308}
309
310static inline void alias_free_mem_rcu(struct fib_alias *fa)
311{
312 call_rcu(&fa->rcu, __alias_free_mem);
313}
314
315#define TNODE_KMALLOC_MAX \
316 ilog2((PAGE_SIZE - TNODE_SIZE(0)) / sizeof(struct key_vector *))
317#define TNODE_VMALLOC_MAX \
318 ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *))
319
320static void __node_free_rcu(struct rcu_head *head)
321{
322 struct tnode *n = container_of(head, struct tnode, rcu);
323
324 if (!n->tn_bits)
325 kmem_cache_free(trie_leaf_kmem, n);
326 else
327 kvfree(n);
328}
329
330#define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu)
331
332static struct tnode *tnode_alloc(int bits)
333{
334 size_t size;
335
336 /* verify bits is within bounds */
337 if (bits > TNODE_VMALLOC_MAX)
338 return NULL;
339
340 /* determine size and verify it is non-zero and didn't overflow */
341 size = TNODE_SIZE(1ul << bits);
342
343 if (size <= PAGE_SIZE)
344 return kzalloc(size, GFP_KERNEL);
345 else
346 return vzalloc(size);
347}
348
349static inline void empty_child_inc(struct key_vector *n)
350{
351 ++tn_info(n)->empty_children ? : ++tn_info(n)->full_children;
352}
353
354static inline void empty_child_dec(struct key_vector *n)
355{
356 tn_info(n)->empty_children-- ? : tn_info(n)->full_children--;
357}
358
359static struct key_vector *leaf_new(t_key key, struct fib_alias *fa)
360{
361 struct key_vector *l;
362 struct tnode *kv;
363
364 kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
365 if (!kv)
366 return NULL;
367
368 /* initialize key vector */
369 l = kv->kv;
370 l->key = key;
371 l->pos = 0;
372 l->bits = 0;
373 l->slen = fa->fa_slen;
374
375 /* link leaf to fib alias */
376 INIT_HLIST_HEAD(&l->leaf);
377 hlist_add_head(&fa->fa_list, &l->leaf);
378
379 return l;
380}
381
382static struct key_vector *tnode_new(t_key key, int pos, int bits)
383{
384 unsigned int shift = pos + bits;
385 struct key_vector *tn;
386 struct tnode *tnode;
387
388 /* verify bits and pos their msb bits clear and values are valid */
389 BUG_ON(!bits || (shift > KEYLENGTH));
390
391 tnode = tnode_alloc(bits);
392 if (!tnode)
393 return NULL;
394
395 pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0),
396 sizeof(struct key_vector *) << bits);
397
398 if (bits == KEYLENGTH)
399 tnode->full_children = 1;
400 else
401 tnode->empty_children = 1ul << bits;
402
403 tn = tnode->kv;
404 tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
405 tn->pos = pos;
406 tn->bits = bits;
407 tn->slen = pos;
408
409 return tn;
410}
411
412/* Check whether a tnode 'n' is "full", i.e. it is an internal node
413 * and no bits are skipped. See discussion in dyntree paper p. 6
414 */
415static inline int tnode_full(struct key_vector *tn, struct key_vector *n)
416{
417 return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n);
418}
419
420/* Add a child at position i overwriting the old value.
421 * Update the value of full_children and empty_children.
422 */
423static void put_child(struct key_vector *tn, unsigned long i,
424 struct key_vector *n)
425{
426 struct key_vector *chi = get_child(tn, i);
427 int isfull, wasfull;
428
429 BUG_ON(i >= child_length(tn));
430
431 /* update emptyChildren, overflow into fullChildren */
432 if (!n && chi)
433 empty_child_inc(tn);
434 if (n && !chi)
435 empty_child_dec(tn);
436
437 /* update fullChildren */
438 wasfull = tnode_full(tn, chi);
439 isfull = tnode_full(tn, n);
440
441 if (wasfull && !isfull)
442 tn_info(tn)->full_children--;
443 else if (!wasfull && isfull)
444 tn_info(tn)->full_children++;
445
446 if (n && (tn->slen < n->slen))
447 tn->slen = n->slen;
448
449 rcu_assign_pointer(tn->tnode[i], n);
450}
451
452static void update_children(struct key_vector *tn)
453{
454 unsigned long i;
455
456 /* update all of the child parent pointers */
457 for (i = child_length(tn); i;) {
458 struct key_vector *inode = get_child(tn, --i);
459
460 if (!inode)
461 continue;
462
463 /* Either update the children of a tnode that
464 * already belongs to us or update the child
465 * to point to ourselves.
466 */
467 if (node_parent(inode) == tn)
468 update_children(inode);
469 else
470 node_set_parent(inode, tn);
471 }
472}
473
474static inline void put_child_root(struct key_vector *tp, t_key key,
475 struct key_vector *n)
476{
477 if (IS_TRIE(tp))
478 rcu_assign_pointer(tp->tnode[0], n);
479 else
480 put_child(tp, get_index(key, tp), n);
481}
482
483static inline void tnode_free_init(struct key_vector *tn)
484{
485 tn_info(tn)->rcu.next = NULL;
486}
487
488static inline void tnode_free_append(struct key_vector *tn,
489 struct key_vector *n)
490{
491 tn_info(n)->rcu.next = tn_info(tn)->rcu.next;
492 tn_info(tn)->rcu.next = &tn_info(n)->rcu;
493}
494
495static void tnode_free(struct key_vector *tn)
496{
497 struct callback_head *head = &tn_info(tn)->rcu;
498
499 while (head) {
500 head = head->next;
501 tnode_free_size += TNODE_SIZE(1ul << tn->bits);
502 node_free(tn);
503
504 tn = container_of(head, struct tnode, rcu)->kv;
505 }
506
507 if (tnode_free_size >= PAGE_SIZE * sync_pages) {
508 tnode_free_size = 0;
509 synchronize_rcu();
510 }
511}
512
513static struct key_vector *replace(struct trie *t,
514 struct key_vector *oldtnode,
515 struct key_vector *tn)
516{
517 struct key_vector *tp = node_parent(oldtnode);
518 unsigned long i;
519
520 /* setup the parent pointer out of and back into this node */
521 NODE_INIT_PARENT(tn, tp);
522 put_child_root(tp, tn->key, tn);
523
524 /* update all of the child parent pointers */
525 update_children(tn);
526
527 /* all pointers should be clean so we are done */
528 tnode_free(oldtnode);
529
530 /* resize children now that oldtnode is freed */
531 for (i = child_length(tn); i;) {
532 struct key_vector *inode = get_child(tn, --i);
533
534 /* resize child node */
535 if (tnode_full(tn, inode))
536 tn = resize(t, inode);
537 }
538
539 return tp;
540}
541
542static struct key_vector *inflate(struct trie *t,
543 struct key_vector *oldtnode)
544{
545 struct key_vector *tn;
546 unsigned long i;
547 t_key m;
548
549 pr_debug("In inflate\n");
550
551 tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1);
552 if (!tn)
553 goto notnode;
554
555 /* prepare oldtnode to be freed */
556 tnode_free_init(oldtnode);
557
558 /* Assemble all of the pointers in our cluster, in this case that
559 * represents all of the pointers out of our allocated nodes that
560 * point to existing tnodes and the links between our allocated
561 * nodes.
562 */
563 for (i = child_length(oldtnode), m = 1u << tn->pos; i;) {
564 struct key_vector *inode = get_child(oldtnode, --i);
565 struct key_vector *node0, *node1;
566 unsigned long j, k;
567
568 /* An empty child */
569 if (!inode)
570 continue;
571
572 /* A leaf or an internal node with skipped bits */
573 if (!tnode_full(oldtnode, inode)) {
574 put_child(tn, get_index(inode->key, tn), inode);
575 continue;
576 }
577
578 /* drop the node in the old tnode free list */
579 tnode_free_append(oldtnode, inode);
580
581 /* An internal node with two children */
582 if (inode->bits == 1) {
583 put_child(tn, 2 * i + 1, get_child(inode, 1));
584 put_child(tn, 2 * i, get_child(inode, 0));
585 continue;
586 }
587
588 /* We will replace this node 'inode' with two new
589 * ones, 'node0' and 'node1', each with half of the
590 * original children. The two new nodes will have
591 * a position one bit further down the key and this
592 * means that the "significant" part of their keys
593 * (see the discussion near the top of this file)
594 * will differ by one bit, which will be "0" in
595 * node0's key and "1" in node1's key. Since we are
596 * moving the key position by one step, the bit that
597 * we are moving away from - the bit at position
598 * (tn->pos) - is the one that will differ between
599 * node0 and node1. So... we synthesize that bit in the
600 * two new keys.
601 */
602 node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1);
603 if (!node1)
604 goto nomem;
605 node0 = tnode_new(inode->key, inode->pos, inode->bits - 1);
606
607 tnode_free_append(tn, node1);
608 if (!node0)
609 goto nomem;
610 tnode_free_append(tn, node0);
611
612 /* populate child pointers in new nodes */
613 for (k = child_length(inode), j = k / 2; j;) {
614 put_child(node1, --j, get_child(inode, --k));
615 put_child(node0, j, get_child(inode, j));
616 put_child(node1, --j, get_child(inode, --k));
617 put_child(node0, j, get_child(inode, j));
618 }
619
620 /* link new nodes to parent */
621 NODE_INIT_PARENT(node1, tn);
622 NODE_INIT_PARENT(node0, tn);
623
624 /* link parent to nodes */
625 put_child(tn, 2 * i + 1, node1);
626 put_child(tn, 2 * i, node0);
627 }
628
629 /* setup the parent pointers into and out of this node */
630 return replace(t, oldtnode, tn);
631nomem:
632 /* all pointers should be clean so we are done */
633 tnode_free(tn);
634notnode:
635 return NULL;
636}
637
638static struct key_vector *halve(struct trie *t,
639 struct key_vector *oldtnode)
640{
641 struct key_vector *tn;
642 unsigned long i;
643
644 pr_debug("In halve\n");
645
646 tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1);
647 if (!tn)
648 goto notnode;
649
650 /* prepare oldtnode to be freed */
651 tnode_free_init(oldtnode);
652
653 /* Assemble all of the pointers in our cluster, in this case that
654 * represents all of the pointers out of our allocated nodes that
655 * point to existing tnodes and the links between our allocated
656 * nodes.
657 */
658 for (i = child_length(oldtnode); i;) {
659 struct key_vector *node1 = get_child(oldtnode, --i);
660 struct key_vector *node0 = get_child(oldtnode, --i);
661 struct key_vector *inode;
662
663 /* At least one of the children is empty */
664 if (!node1 || !node0) {
665 put_child(tn, i / 2, node1 ? : node0);
666 continue;
667 }
668
669 /* Two nonempty children */
670 inode = tnode_new(node0->key, oldtnode->pos, 1);
671 if (!inode)
672 goto nomem;
673 tnode_free_append(tn, inode);
674
675 /* initialize pointers out of node */
676 put_child(inode, 1, node1);
677 put_child(inode, 0, node0);
678 NODE_INIT_PARENT(inode, tn);
679
680 /* link parent to node */
681 put_child(tn, i / 2, inode);
682 }
683
684 /* setup the parent pointers into and out of this node */
685 return replace(t, oldtnode, tn);
686nomem:
687 /* all pointers should be clean so we are done */
688 tnode_free(tn);
689notnode:
690 return NULL;
691}
692
693static struct key_vector *collapse(struct trie *t,
694 struct key_vector *oldtnode)
695{
696 struct key_vector *n, *tp;
697 unsigned long i;
698
699 /* scan the tnode looking for that one child that might still exist */
700 for (n = NULL, i = child_length(oldtnode); !n && i;)
701 n = get_child(oldtnode, --i);
702
703 /* compress one level */
704 tp = node_parent(oldtnode);
705 put_child_root(tp, oldtnode->key, n);
706 node_set_parent(n, tp);
707
708 /* drop dead node */
709 node_free(oldtnode);
710
711 return tp;
712}
713
714static unsigned char update_suffix(struct key_vector *tn)
715{
716 unsigned char slen = tn->pos;
717 unsigned long stride, i;
718 unsigned char slen_max;
719
720 /* only vector 0 can have a suffix length greater than or equal to
721 * tn->pos + tn->bits, the second highest node will have a suffix
722 * length at most of tn->pos + tn->bits - 1
723 */
724 slen_max = min_t(unsigned char, tn->pos + tn->bits - 1, tn->slen);
725
726 /* search though the list of children looking for nodes that might
727 * have a suffix greater than the one we currently have. This is
728 * why we start with a stride of 2 since a stride of 1 would
729 * represent the nodes with suffix length equal to tn->pos
730 */
731 for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) {
732 struct key_vector *n = get_child(tn, i);
733
734 if (!n || (n->slen <= slen))
735 continue;
736
737 /* update stride and slen based on new value */
738 stride <<= (n->slen - slen);
739 slen = n->slen;
740 i &= ~(stride - 1);
741
742 /* stop searching if we have hit the maximum possible value */
743 if (slen >= slen_max)
744 break;
745 }
746
747 tn->slen = slen;
748
749 return slen;
750}
751
752/* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
753 * the Helsinki University of Technology and Matti Tikkanen of Nokia
754 * Telecommunications, page 6:
755 * "A node is doubled if the ratio of non-empty children to all
756 * children in the *doubled* node is at least 'high'."
757 *
758 * 'high' in this instance is the variable 'inflate_threshold'. It
759 * is expressed as a percentage, so we multiply it with
760 * child_length() and instead of multiplying by 2 (since the
761 * child array will be doubled by inflate()) and multiplying
762 * the left-hand side by 100 (to handle the percentage thing) we
763 * multiply the left-hand side by 50.
764 *
765 * The left-hand side may look a bit weird: child_length(tn)
766 * - tn->empty_children is of course the number of non-null children
767 * in the current node. tn->full_children is the number of "full"
768 * children, that is non-null tnodes with a skip value of 0.
769 * All of those will be doubled in the resulting inflated tnode, so
770 * we just count them one extra time here.
771 *
772 * A clearer way to write this would be:
773 *
774 * to_be_doubled = tn->full_children;
775 * not_to_be_doubled = child_length(tn) - tn->empty_children -
776 * tn->full_children;
777 *
778 * new_child_length = child_length(tn) * 2;
779 *
780 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
781 * new_child_length;
782 * if (new_fill_factor >= inflate_threshold)
783 *
784 * ...and so on, tho it would mess up the while () loop.
785 *
786 * anyway,
787 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
788 * inflate_threshold
789 *
790 * avoid a division:
791 * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
792 * inflate_threshold * new_child_length
793 *
794 * expand not_to_be_doubled and to_be_doubled, and shorten:
795 * 100 * (child_length(tn) - tn->empty_children +
796 * tn->full_children) >= inflate_threshold * new_child_length
797 *
798 * expand new_child_length:
799 * 100 * (child_length(tn) - tn->empty_children +
800 * tn->full_children) >=
801 * inflate_threshold * child_length(tn) * 2
802 *
803 * shorten again:
804 * 50 * (tn->full_children + child_length(tn) -
805 * tn->empty_children) >= inflate_threshold *
806 * child_length(tn)
807 *
808 */
809static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn)
810{
811 unsigned long used = child_length(tn);
812 unsigned long threshold = used;
813
814 /* Keep root node larger */
815 threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold;
816 used -= tn_info(tn)->empty_children;
817 used += tn_info(tn)->full_children;
818
819 /* if bits == KEYLENGTH then pos = 0, and will fail below */
820
821 return (used > 1) && tn->pos && ((50 * used) >= threshold);
822}
823
824static inline bool should_halve(struct key_vector *tp, struct key_vector *tn)
825{
826 unsigned long used = child_length(tn);
827 unsigned long threshold = used;
828
829 /* Keep root node larger */
830 threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold;
831 used -= tn_info(tn)->empty_children;
832
833 /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */
834
835 return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold);
836}
837
838static inline bool should_collapse(struct key_vector *tn)
839{
840 unsigned long used = child_length(tn);
841
842 used -= tn_info(tn)->empty_children;
843
844 /* account for bits == KEYLENGTH case */
845 if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children)
846 used -= KEY_MAX;
847
848 /* One child or none, time to drop us from the trie */
849 return used < 2;
850}
851
852#define MAX_WORK 10
853static struct key_vector *resize(struct trie *t, struct key_vector *tn)
854{
855#ifdef CONFIG_IP_FIB_TRIE_STATS
856 struct trie_use_stats __percpu *stats = t->stats;
857#endif
858 struct key_vector *tp = node_parent(tn);
859 unsigned long cindex = get_index(tn->key, tp);
860 int max_work = MAX_WORK;
861
862 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
863 tn, inflate_threshold, halve_threshold);
864
865 /* track the tnode via the pointer from the parent instead of
866 * doing it ourselves. This way we can let RCU fully do its
867 * thing without us interfering
868 */
869 BUG_ON(tn != get_child(tp, cindex));
870
871 /* Double as long as the resulting node has a number of
872 * nonempty nodes that are above the threshold.
873 */
874 while (should_inflate(tp, tn) && max_work) {
875 tp = inflate(t, tn);
876 if (!tp) {
877#ifdef CONFIG_IP_FIB_TRIE_STATS
878 this_cpu_inc(stats->resize_node_skipped);
879#endif
880 break;
881 }
882
883 max_work--;
884 tn = get_child(tp, cindex);
885 }
886
887 /* update parent in case inflate failed */
888 tp = node_parent(tn);
889
890 /* Return if at least one inflate is run */
891 if (max_work != MAX_WORK)
892 return tp;
893
894 /* Halve as long as the number of empty children in this
895 * node is above threshold.
896 */
897 while (should_halve(tp, tn) && max_work) {
898 tp = halve(t, tn);
899 if (!tp) {
900#ifdef CONFIG_IP_FIB_TRIE_STATS
901 this_cpu_inc(stats->resize_node_skipped);
902#endif
903 break;
904 }
905
906 max_work--;
907 tn = get_child(tp, cindex);
908 }
909
910 /* Only one child remains */
911 if (should_collapse(tn))
912 return collapse(t, tn);
913
914 /* update parent in case halve failed */
915 return node_parent(tn);
916}
917
918static void node_pull_suffix(struct key_vector *tn, unsigned char slen)
919{
920 unsigned char node_slen = tn->slen;
921
922 while ((node_slen > tn->pos) && (node_slen > slen)) {
923 slen = update_suffix(tn);
924 if (node_slen == slen)
925 break;
926
927 tn = node_parent(tn);
928 node_slen = tn->slen;
929 }
930}
931
932static void node_push_suffix(struct key_vector *tn, unsigned char slen)
933{
934 while (tn->slen < slen) {
935 tn->slen = slen;
936 tn = node_parent(tn);
937 }
938}
939
940/* rcu_read_lock needs to be hold by caller from readside */
941static struct key_vector *fib_find_node(struct trie *t,
942 struct key_vector **tp, u32 key)
943{
944 struct key_vector *pn, *n = t->kv;
945 unsigned long index = 0;
946
947 do {
948 pn = n;
949 n = get_child_rcu(n, index);
950
951 if (!n)
952 break;
953
954 index = get_cindex(key, n);
955
956 /* This bit of code is a bit tricky but it combines multiple
957 * checks into a single check. The prefix consists of the
958 * prefix plus zeros for the bits in the cindex. The index
959 * is the difference between the key and this value. From
960 * this we can actually derive several pieces of data.
961 * if (index >= (1ul << bits))
962 * we have a mismatch in skip bits and failed
963 * else
964 * we know the value is cindex
965 *
966 * This check is safe even if bits == KEYLENGTH due to the
967 * fact that we can only allocate a node with 32 bits if a
968 * long is greater than 32 bits.
969 */
970 if (index >= (1ul << n->bits)) {
971 n = NULL;
972 break;
973 }
974
975 /* keep searching until we find a perfect match leaf or NULL */
976 } while (IS_TNODE(n));
977
978 *tp = pn;
979
980 return n;
981}
982
983/* Return the first fib alias matching TOS with
984 * priority less than or equal to PRIO.
985 */
986static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen,
987 u8 tos, u32 prio, u32 tb_id)
988{
989 struct fib_alias *fa;
990
991 if (!fah)
992 return NULL;
993
994 hlist_for_each_entry(fa, fah, fa_list) {
995 if (fa->fa_slen < slen)
996 continue;
997 if (fa->fa_slen != slen)
998 break;
999 if (fa->tb_id > tb_id)
1000 continue;
1001 if (fa->tb_id != tb_id)
1002 break;
1003 if (fa->fa_tos > tos)
1004 continue;
1005 if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos)
1006 return fa;
1007 }
1008
1009 return NULL;
1010}
1011
1012static void trie_rebalance(struct trie *t, struct key_vector *tn)
1013{
1014 while (!IS_TRIE(tn))
1015 tn = resize(t, tn);
1016}
1017
1018static int fib_insert_node(struct trie *t, struct key_vector *tp,
1019 struct fib_alias *new, t_key key)
1020{
1021 struct key_vector *n, *l;
1022
1023 l = leaf_new(key, new);
1024 if (!l)
1025 goto noleaf;
1026
1027 /* retrieve child from parent node */
1028 n = get_child(tp, get_index(key, tp));
1029
1030 /* Case 2: n is a LEAF or a TNODE and the key doesn't match.
1031 *
1032 * Add a new tnode here
1033 * first tnode need some special handling
1034 * leaves us in position for handling as case 3
1035 */
1036 if (n) {
1037 struct key_vector *tn;
1038
1039 tn = tnode_new(key, __fls(key ^ n->key), 1);
1040 if (!tn)
1041 goto notnode;
1042
1043 /* initialize routes out of node */
1044 NODE_INIT_PARENT(tn, tp);
1045 put_child(tn, get_index(key, tn) ^ 1, n);
1046
1047 /* start adding routes into the node */
1048 put_child_root(tp, key, tn);
1049 node_set_parent(n, tn);
1050
1051 /* parent now has a NULL spot where the leaf can go */
1052 tp = tn;
1053 }
1054
1055 /* Case 3: n is NULL, and will just insert a new leaf */
1056 node_push_suffix(tp, new->fa_slen);
1057 NODE_INIT_PARENT(l, tp);
1058 put_child_root(tp, key, l);
1059 trie_rebalance(t, tp);
1060
1061 return 0;
1062notnode:
1063 node_free(l);
1064noleaf:
1065 return -ENOMEM;
1066}
1067
1068/* fib notifier for ADD is sent before calling fib_insert_alias with
1069 * the expectation that the only possible failure ENOMEM
1070 */
1071static int fib_insert_alias(struct trie *t, struct key_vector *tp,
1072 struct key_vector *l, struct fib_alias *new,
1073 struct fib_alias *fa, t_key key)
1074{
1075 if (!l)
1076 return fib_insert_node(t, tp, new, key);
1077
1078 if (fa) {
1079 hlist_add_before_rcu(&new->fa_list, &fa->fa_list);
1080 } else {
1081 struct fib_alias *last;
1082
1083 hlist_for_each_entry(last, &l->leaf, fa_list) {
1084 if (new->fa_slen < last->fa_slen)
1085 break;
1086 if ((new->fa_slen == last->fa_slen) &&
1087 (new->tb_id > last->tb_id))
1088 break;
1089 fa = last;
1090 }
1091
1092 if (fa)
1093 hlist_add_behind_rcu(&new->fa_list, &fa->fa_list);
1094 else
1095 hlist_add_head_rcu(&new->fa_list, &l->leaf);
1096 }
1097
1098 /* if we added to the tail node then we need to update slen */
1099 if (l->slen < new->fa_slen) {
1100 l->slen = new->fa_slen;
1101 node_push_suffix(tp, new->fa_slen);
1102 }
1103
1104 return 0;
1105}
1106
1107static bool fib_valid_key_len(u32 key, u8 plen, struct netlink_ext_ack *extack)
1108{
1109 if (plen > KEYLENGTH) {
1110 NL_SET_ERR_MSG(extack, "Invalid prefix length");
1111 return false;
1112 }
1113
1114 if ((plen < KEYLENGTH) && (key << plen)) {
1115 NL_SET_ERR_MSG(extack,
1116 "Invalid prefix for given prefix length");
1117 return false;
1118 }
1119
1120 return true;
1121}
1122
1123/* Caller must hold RTNL. */
1124int fib_table_insert(struct net *net, struct fib_table *tb,
1125 struct fib_config *cfg, struct netlink_ext_ack *extack)
1126{
1127 enum fib_event_type event = FIB_EVENT_ENTRY_ADD;
1128 struct trie *t = (struct trie *)tb->tb_data;
1129 struct fib_alias *fa, *new_fa;
1130 struct key_vector *l, *tp;
1131 u16 nlflags = NLM_F_EXCL;
1132 struct fib_info *fi;
1133 u8 plen = cfg->fc_dst_len;
1134 u8 slen = KEYLENGTH - plen;
1135 u8 tos = cfg->fc_tos;
1136 u32 key;
1137 int err;
1138
1139 key = ntohl(cfg->fc_dst);
1140
1141 if (!fib_valid_key_len(key, plen, extack))
1142 return -EINVAL;
1143
1144 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
1145
1146 fi = fib_create_info(cfg, extack);
1147 if (IS_ERR(fi)) {
1148 err = PTR_ERR(fi);
1149 goto err;
1150 }
1151
1152 l = fib_find_node(t, &tp, key);
1153 fa = l ? fib_find_alias(&l->leaf, slen, tos, fi->fib_priority,
1154 tb->tb_id) : NULL;
1155
1156 /* Now fa, if non-NULL, points to the first fib alias
1157 * with the same keys [prefix,tos,priority], if such key already
1158 * exists or to the node before which we will insert new one.
1159 *
1160 * If fa is NULL, we will need to allocate a new one and
1161 * insert to the tail of the section matching the suffix length
1162 * of the new alias.
1163 */
1164
1165 if (fa && fa->fa_tos == tos &&
1166 fa->fa_info->fib_priority == fi->fib_priority) {
1167 struct fib_alias *fa_first, *fa_match;
1168
1169 err = -EEXIST;
1170 if (cfg->fc_nlflags & NLM_F_EXCL)
1171 goto out;
1172
1173 nlflags &= ~NLM_F_EXCL;
1174
1175 /* We have 2 goals:
1176 * 1. Find exact match for type, scope, fib_info to avoid
1177 * duplicate routes
1178 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
1179 */
1180 fa_match = NULL;
1181 fa_first = fa;
1182 hlist_for_each_entry_from(fa, fa_list) {
1183 if ((fa->fa_slen != slen) ||
1184 (fa->tb_id != tb->tb_id) ||
1185 (fa->fa_tos != tos))
1186 break;
1187 if (fa->fa_info->fib_priority != fi->fib_priority)
1188 break;
1189 if (fa->fa_type == cfg->fc_type &&
1190 fa->fa_info == fi) {
1191 fa_match = fa;
1192 break;
1193 }
1194 }
1195
1196 if (cfg->fc_nlflags & NLM_F_REPLACE) {
1197 struct fib_info *fi_drop;
1198 u8 state;
1199
1200 nlflags |= NLM_F_REPLACE;
1201 fa = fa_first;
1202 if (fa_match) {
1203 if (fa == fa_match)
1204 err = 0;
1205 goto out;
1206 }
1207 err = -ENOBUFS;
1208 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1209 if (!new_fa)
1210 goto out;
1211
1212 fi_drop = fa->fa_info;
1213 new_fa->fa_tos = fa->fa_tos;
1214 new_fa->fa_info = fi;
1215 new_fa->fa_type = cfg->fc_type;
1216 state = fa->fa_state;
1217 new_fa->fa_state = state & ~FA_S_ACCESSED;
1218 new_fa->fa_slen = fa->fa_slen;
1219 new_fa->tb_id = tb->tb_id;
1220 new_fa->fa_default = -1;
1221
1222 err = call_fib_entry_notifiers(net,
1223 FIB_EVENT_ENTRY_REPLACE,
1224 key, plen, new_fa,
1225 extack);
1226 if (err)
1227 goto out_free_new_fa;
1228
1229 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
1230 tb->tb_id, &cfg->fc_nlinfo, nlflags);
1231
1232 hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list);
1233
1234 alias_free_mem_rcu(fa);
1235
1236 fib_release_info(fi_drop);
1237 if (state & FA_S_ACCESSED)
1238 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1239
1240 goto succeeded;
1241 }
1242 /* Error if we find a perfect match which
1243 * uses the same scope, type, and nexthop
1244 * information.
1245 */
1246 if (fa_match)
1247 goto out;
1248
1249 if (cfg->fc_nlflags & NLM_F_APPEND) {
1250 event = FIB_EVENT_ENTRY_APPEND;
1251 nlflags |= NLM_F_APPEND;
1252 } else {
1253 fa = fa_first;
1254 }
1255 }
1256 err = -ENOENT;
1257 if (!(cfg->fc_nlflags & NLM_F_CREATE))
1258 goto out;
1259
1260 nlflags |= NLM_F_CREATE;
1261 err = -ENOBUFS;
1262 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1263 if (!new_fa)
1264 goto out;
1265
1266 new_fa->fa_info = fi;
1267 new_fa->fa_tos = tos;
1268 new_fa->fa_type = cfg->fc_type;
1269 new_fa->fa_state = 0;
1270 new_fa->fa_slen = slen;
1271 new_fa->tb_id = tb->tb_id;
1272 new_fa->fa_default = -1;
1273
1274 err = call_fib_entry_notifiers(net, event, key, plen, new_fa, extack);
1275 if (err)
1276 goto out_free_new_fa;
1277
1278 /* Insert new entry to the list. */
1279 err = fib_insert_alias(t, tp, l, new_fa, fa, key);
1280 if (err)
1281 goto out_fib_notif;
1282
1283 if (!plen)
1284 tb->tb_num_default++;
1285
1286 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1287 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id,
1288 &cfg->fc_nlinfo, nlflags);
1289succeeded:
1290 return 0;
1291
1292out_fib_notif:
1293 /* notifier was sent that entry would be added to trie, but
1294 * the add failed and need to recover. Only failure for
1295 * fib_insert_alias is ENOMEM.
1296 */
1297 NL_SET_ERR_MSG(extack, "Failed to insert route into trie");
1298 call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, key,
1299 plen, new_fa, NULL);
1300out_free_new_fa:
1301 kmem_cache_free(fn_alias_kmem, new_fa);
1302out:
1303 fib_release_info(fi);
1304err:
1305 return err;
1306}
1307
1308static inline t_key prefix_mismatch(t_key key, struct key_vector *n)
1309{
1310 t_key prefix = n->key;
1311
1312 return (key ^ prefix) & (prefix | -prefix);
1313}
1314
1315/* should be called with rcu_read_lock */
1316int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
1317 struct fib_result *res, int fib_flags)
1318{
1319 struct trie *t = (struct trie *) tb->tb_data;
1320#ifdef CONFIG_IP_FIB_TRIE_STATS
1321 struct trie_use_stats __percpu *stats = t->stats;
1322#endif
1323 const t_key key = ntohl(flp->daddr);
1324 struct key_vector *n, *pn;
1325 struct fib_alias *fa;
1326 unsigned long index;
1327 t_key cindex;
1328
1329 trace_fib_table_lookup(tb->tb_id, flp);
1330
1331 pn = t->kv;
1332 cindex = 0;
1333
1334 n = get_child_rcu(pn, cindex);
1335 if (!n)
1336 return -EAGAIN;
1337
1338#ifdef CONFIG_IP_FIB_TRIE_STATS
1339 this_cpu_inc(stats->gets);
1340#endif
1341
1342 /* Step 1: Travel to the longest prefix match in the trie */
1343 for (;;) {
1344 index = get_cindex(key, n);
1345
1346 /* This bit of code is a bit tricky but it combines multiple
1347 * checks into a single check. The prefix consists of the
1348 * prefix plus zeros for the "bits" in the prefix. The index
1349 * is the difference between the key and this value. From
1350 * this we can actually derive several pieces of data.
1351 * if (index >= (1ul << bits))
1352 * we have a mismatch in skip bits and failed
1353 * else
1354 * we know the value is cindex
1355 *
1356 * This check is safe even if bits == KEYLENGTH due to the
1357 * fact that we can only allocate a node with 32 bits if a
1358 * long is greater than 32 bits.
1359 */
1360 if (index >= (1ul << n->bits))
1361 break;
1362
1363 /* we have found a leaf. Prefixes have already been compared */
1364 if (IS_LEAF(n))
1365 goto found;
1366
1367 /* only record pn and cindex if we are going to be chopping
1368 * bits later. Otherwise we are just wasting cycles.
1369 */
1370 if (n->slen > n->pos) {
1371 pn = n;
1372 cindex = index;
1373 }
1374
1375 n = get_child_rcu(n, index);
1376 if (unlikely(!n))
1377 goto backtrace;
1378 }
1379
1380 /* Step 2: Sort out leaves and begin backtracing for longest prefix */
1381 for (;;) {
1382 /* record the pointer where our next node pointer is stored */
1383 struct key_vector __rcu **cptr = n->tnode;
1384
1385 /* This test verifies that none of the bits that differ
1386 * between the key and the prefix exist in the region of
1387 * the lsb and higher in the prefix.
1388 */
1389 if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos))
1390 goto backtrace;
1391
1392 /* exit out and process leaf */
1393 if (unlikely(IS_LEAF(n)))
1394 break;
1395
1396 /* Don't bother recording parent info. Since we are in
1397 * prefix match mode we will have to come back to wherever
1398 * we started this traversal anyway
1399 */
1400
1401 while ((n = rcu_dereference(*cptr)) == NULL) {
1402backtrace:
1403#ifdef CONFIG_IP_FIB_TRIE_STATS
1404 if (!n)
1405 this_cpu_inc(stats->null_node_hit);
1406#endif
1407 /* If we are at cindex 0 there are no more bits for
1408 * us to strip at this level so we must ascend back
1409 * up one level to see if there are any more bits to
1410 * be stripped there.
1411 */
1412 while (!cindex) {
1413 t_key pkey = pn->key;
1414
1415 /* If we don't have a parent then there is
1416 * nothing for us to do as we do not have any
1417 * further nodes to parse.
1418 */
1419 if (IS_TRIE(pn))
1420 return -EAGAIN;
1421#ifdef CONFIG_IP_FIB_TRIE_STATS
1422 this_cpu_inc(stats->backtrack);
1423#endif
1424 /* Get Child's index */
1425 pn = node_parent_rcu(pn);
1426 cindex = get_index(pkey, pn);
1427 }
1428
1429 /* strip the least significant bit from the cindex */
1430 cindex &= cindex - 1;
1431
1432 /* grab pointer for next child node */
1433 cptr = &pn->tnode[cindex];
1434 }
1435 }
1436
1437found:
1438 /* this line carries forward the xor from earlier in the function */
1439 index = key ^ n->key;
1440
1441 /* Step 3: Process the leaf, if that fails fall back to backtracing */
1442 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
1443 struct fib_info *fi = fa->fa_info;
1444 int nhsel, err;
1445
1446 if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) {
1447 if (index >= (1ul << fa->fa_slen))
1448 continue;
1449 }
1450 if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
1451 continue;
1452 if (fi->fib_dead)
1453 continue;
1454 if (fa->fa_info->fib_scope < flp->flowi4_scope)
1455 continue;
1456 fib_alias_accessed(fa);
1457 err = fib_props[fa->fa_type].error;
1458 if (unlikely(err < 0)) {
1459#ifdef CONFIG_IP_FIB_TRIE_STATS
1460 this_cpu_inc(stats->semantic_match_passed);
1461#endif
1462 return err;
1463 }
1464 if (fi->fib_flags & RTNH_F_DEAD)
1465 continue;
1466 for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) {
1467 const struct fib_nh *nh = &fi->fib_nh[nhsel];
1468 struct in_device *in_dev = __in_dev_get_rcu(nh->nh_dev);
1469
1470 if (nh->nh_flags & RTNH_F_DEAD)
1471 continue;
1472 if (in_dev &&
1473 IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) &&
1474 nh->nh_flags & RTNH_F_LINKDOWN &&
1475 !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE))
1476 continue;
1477 if (!(flp->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) {
1478 if (flp->flowi4_oif &&
1479 flp->flowi4_oif != nh->nh_oif)
1480 continue;
1481 }
1482
1483 if (!(fib_flags & FIB_LOOKUP_NOREF))
1484 refcount_inc(&fi->fib_clntref);
1485
1486 res->prefix = htonl(n->key);
1487 res->prefixlen = KEYLENGTH - fa->fa_slen;
1488 res->nh_sel = nhsel;
1489 res->type = fa->fa_type;
1490 res->scope = fi->fib_scope;
1491 res->fi = fi;
1492 res->table = tb;
1493 res->fa_head = &n->leaf;
1494#ifdef CONFIG_IP_FIB_TRIE_STATS
1495 this_cpu_inc(stats->semantic_match_passed);
1496#endif
1497 trace_fib_table_lookup_nh(nh);
1498
1499 return err;
1500 }
1501 }
1502#ifdef CONFIG_IP_FIB_TRIE_STATS
1503 this_cpu_inc(stats->semantic_match_miss);
1504#endif
1505 goto backtrace;
1506}
1507EXPORT_SYMBOL_GPL(fib_table_lookup);
1508
1509static void fib_remove_alias(struct trie *t, struct key_vector *tp,
1510 struct key_vector *l, struct fib_alias *old)
1511{
1512 /* record the location of the previous list_info entry */
1513 struct hlist_node **pprev = old->fa_list.pprev;
1514 struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next);
1515
1516 /* remove the fib_alias from the list */
1517 hlist_del_rcu(&old->fa_list);
1518
1519 /* if we emptied the list this leaf will be freed and we can sort
1520 * out parent suffix lengths as a part of trie_rebalance
1521 */
1522 if (hlist_empty(&l->leaf)) {
1523 if (tp->slen == l->slen)
1524 node_pull_suffix(tp, tp->pos);
1525 put_child_root(tp, l->key, NULL);
1526 node_free(l);
1527 trie_rebalance(t, tp);
1528 return;
1529 }
1530
1531 /* only access fa if it is pointing at the last valid hlist_node */
1532 if (*pprev)
1533 return;
1534
1535 /* update the trie with the latest suffix length */
1536 l->slen = fa->fa_slen;
1537 node_pull_suffix(tp, fa->fa_slen);
1538}
1539
1540/* Caller must hold RTNL. */
1541int fib_table_delete(struct net *net, struct fib_table *tb,
1542 struct fib_config *cfg, struct netlink_ext_ack *extack)
1543{
1544 struct trie *t = (struct trie *) tb->tb_data;
1545 struct fib_alias *fa, *fa_to_delete;
1546 struct key_vector *l, *tp;
1547 u8 plen = cfg->fc_dst_len;
1548 u8 slen = KEYLENGTH - plen;
1549 u8 tos = cfg->fc_tos;
1550 u32 key;
1551
1552 key = ntohl(cfg->fc_dst);
1553
1554 if (!fib_valid_key_len(key, plen, extack))
1555 return -EINVAL;
1556
1557 l = fib_find_node(t, &tp, key);
1558 if (!l)
1559 return -ESRCH;
1560
1561 fa = fib_find_alias(&l->leaf, slen, tos, 0, tb->tb_id);
1562 if (!fa)
1563 return -ESRCH;
1564
1565 pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
1566
1567 fa_to_delete = NULL;
1568 hlist_for_each_entry_from(fa, fa_list) {
1569 struct fib_info *fi = fa->fa_info;
1570
1571 if ((fa->fa_slen != slen) ||
1572 (fa->tb_id != tb->tb_id) ||
1573 (fa->fa_tos != tos))
1574 break;
1575
1576 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
1577 (cfg->fc_scope == RT_SCOPE_NOWHERE ||
1578 fa->fa_info->fib_scope == cfg->fc_scope) &&
1579 (!cfg->fc_prefsrc ||
1580 fi->fib_prefsrc == cfg->fc_prefsrc) &&
1581 (!cfg->fc_protocol ||
1582 fi->fib_protocol == cfg->fc_protocol) &&
1583 fib_nh_match(cfg, fi, extack) == 0 &&
1584 fib_metrics_match(cfg, fi)) {
1585 fa_to_delete = fa;
1586 break;
1587 }
1588 }
1589
1590 if (!fa_to_delete)
1591 return -ESRCH;
1592
1593 call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, key, plen,
1594 fa_to_delete, extack);
1595 rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id,
1596 &cfg->fc_nlinfo, 0);
1597
1598 if (!plen)
1599 tb->tb_num_default--;
1600
1601 fib_remove_alias(t, tp, l, fa_to_delete);
1602
1603 if (fa_to_delete->fa_state & FA_S_ACCESSED)
1604 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1605
1606 fib_release_info(fa_to_delete->fa_info);
1607 alias_free_mem_rcu(fa_to_delete);
1608 return 0;
1609}
1610
1611/* Scan for the next leaf starting at the provided key value */
1612static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key)
1613{
1614 struct key_vector *pn, *n = *tn;
1615 unsigned long cindex;
1616
1617 /* this loop is meant to try and find the key in the trie */
1618 do {
1619 /* record parent and next child index */
1620 pn = n;
1621 cindex = (key > pn->key) ? get_index(key, pn) : 0;
1622
1623 if (cindex >> pn->bits)
1624 break;
1625
1626 /* descend into the next child */
1627 n = get_child_rcu(pn, cindex++);
1628 if (!n)
1629 break;
1630
1631 /* guarantee forward progress on the keys */
1632 if (IS_LEAF(n) && (n->key >= key))
1633 goto found;
1634 } while (IS_TNODE(n));
1635
1636 /* this loop will search for the next leaf with a greater key */
1637 while (!IS_TRIE(pn)) {
1638 /* if we exhausted the parent node we will need to climb */
1639 if (cindex >= (1ul << pn->bits)) {
1640 t_key pkey = pn->key;
1641
1642 pn = node_parent_rcu(pn);
1643 cindex = get_index(pkey, pn) + 1;
1644 continue;
1645 }
1646
1647 /* grab the next available node */
1648 n = get_child_rcu(pn, cindex++);
1649 if (!n)
1650 continue;
1651
1652 /* no need to compare keys since we bumped the index */
1653 if (IS_LEAF(n))
1654 goto found;
1655
1656 /* Rescan start scanning in new node */
1657 pn = n;
1658 cindex = 0;
1659 }
1660
1661 *tn = pn;
1662 return NULL; /* Root of trie */
1663found:
1664 /* if we are at the limit for keys just return NULL for the tnode */
1665 *tn = pn;
1666 return n;
1667}
1668
1669static void fib_trie_free(struct fib_table *tb)
1670{
1671 struct trie *t = (struct trie *)tb->tb_data;
1672 struct key_vector *pn = t->kv;
1673 unsigned long cindex = 1;
1674 struct hlist_node *tmp;
1675 struct fib_alias *fa;
1676
1677 /* walk trie in reverse order and free everything */
1678 for (;;) {
1679 struct key_vector *n;
1680
1681 if (!(cindex--)) {
1682 t_key pkey = pn->key;
1683
1684 if (IS_TRIE(pn))
1685 break;
1686
1687 n = pn;
1688 pn = node_parent(pn);
1689
1690 /* drop emptied tnode */
1691 put_child_root(pn, n->key, NULL);
1692 node_free(n);
1693
1694 cindex = get_index(pkey, pn);
1695
1696 continue;
1697 }
1698
1699 /* grab the next available node */
1700 n = get_child(pn, cindex);
1701 if (!n)
1702 continue;
1703
1704 if (IS_TNODE(n)) {
1705 /* record pn and cindex for leaf walking */
1706 pn = n;
1707 cindex = 1ul << n->bits;
1708
1709 continue;
1710 }
1711
1712 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1713 hlist_del_rcu(&fa->fa_list);
1714 alias_free_mem_rcu(fa);
1715 }
1716
1717 put_child_root(pn, n->key, NULL);
1718 node_free(n);
1719 }
1720
1721#ifdef CONFIG_IP_FIB_TRIE_STATS
1722 free_percpu(t->stats);
1723#endif
1724 kfree(tb);
1725}
1726
1727struct fib_table *fib_trie_unmerge(struct fib_table *oldtb)
1728{
1729 struct trie *ot = (struct trie *)oldtb->tb_data;
1730 struct key_vector *l, *tp = ot->kv;
1731 struct fib_table *local_tb;
1732 struct fib_alias *fa;
1733 struct trie *lt;
1734 t_key key = 0;
1735
1736 if (oldtb->tb_data == oldtb->__data)
1737 return oldtb;
1738
1739 local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL);
1740 if (!local_tb)
1741 return NULL;
1742
1743 lt = (struct trie *)local_tb->tb_data;
1744
1745 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
1746 struct key_vector *local_l = NULL, *local_tp;
1747
1748 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
1749 struct fib_alias *new_fa;
1750
1751 if (local_tb->tb_id != fa->tb_id)
1752 continue;
1753
1754 /* clone fa for new local table */
1755 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1756 if (!new_fa)
1757 goto out;
1758
1759 memcpy(new_fa, fa, sizeof(*fa));
1760
1761 /* insert clone into table */
1762 if (!local_l)
1763 local_l = fib_find_node(lt, &local_tp, l->key);
1764
1765 if (fib_insert_alias(lt, local_tp, local_l, new_fa,
1766 NULL, l->key)) {
1767 kmem_cache_free(fn_alias_kmem, new_fa);
1768 goto out;
1769 }
1770 }
1771
1772 /* stop loop if key wrapped back to 0 */
1773 key = l->key + 1;
1774 if (key < l->key)
1775 break;
1776 }
1777
1778 return local_tb;
1779out:
1780 fib_trie_free(local_tb);
1781
1782 return NULL;
1783}
1784
1785/* Caller must hold RTNL */
1786void fib_table_flush_external(struct fib_table *tb)
1787{
1788 struct trie *t = (struct trie *)tb->tb_data;
1789 struct key_vector *pn = t->kv;
1790 unsigned long cindex = 1;
1791 struct hlist_node *tmp;
1792 struct fib_alias *fa;
1793
1794 /* walk trie in reverse order */
1795 for (;;) {
1796 unsigned char slen = 0;
1797 struct key_vector *n;
1798
1799 if (!(cindex--)) {
1800 t_key pkey = pn->key;
1801
1802 /* cannot resize the trie vector */
1803 if (IS_TRIE(pn))
1804 break;
1805
1806 /* update the suffix to address pulled leaves */
1807 if (pn->slen > pn->pos)
1808 update_suffix(pn);
1809
1810 /* resize completed node */
1811 pn = resize(t, pn);
1812 cindex = get_index(pkey, pn);
1813
1814 continue;
1815 }
1816
1817 /* grab the next available node */
1818 n = get_child(pn, cindex);
1819 if (!n)
1820 continue;
1821
1822 if (IS_TNODE(n)) {
1823 /* record pn and cindex for leaf walking */
1824 pn = n;
1825 cindex = 1ul << n->bits;
1826
1827 continue;
1828 }
1829
1830 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1831 /* if alias was cloned to local then we just
1832 * need to remove the local copy from main
1833 */
1834 if (tb->tb_id != fa->tb_id) {
1835 hlist_del_rcu(&fa->fa_list);
1836 alias_free_mem_rcu(fa);
1837 continue;
1838 }
1839
1840 /* record local slen */
1841 slen = fa->fa_slen;
1842 }
1843
1844 /* update leaf slen */
1845 n->slen = slen;
1846
1847 if (hlist_empty(&n->leaf)) {
1848 put_child_root(pn, n->key, NULL);
1849 node_free(n);
1850 }
1851 }
1852}
1853
1854/* Caller must hold RTNL. */
1855int fib_table_flush(struct net *net, struct fib_table *tb)
1856{
1857 struct trie *t = (struct trie *)tb->tb_data;
1858 struct key_vector *pn = t->kv;
1859 unsigned long cindex = 1;
1860 struct hlist_node *tmp;
1861 struct fib_alias *fa;
1862 int found = 0;
1863
1864 /* walk trie in reverse order */
1865 for (;;) {
1866 unsigned char slen = 0;
1867 struct key_vector *n;
1868
1869 if (!(cindex--)) {
1870 t_key pkey = pn->key;
1871
1872 /* cannot resize the trie vector */
1873 if (IS_TRIE(pn))
1874 break;
1875
1876 /* update the suffix to address pulled leaves */
1877 if (pn->slen > pn->pos)
1878 update_suffix(pn);
1879
1880 /* resize completed node */
1881 pn = resize(t, pn);
1882 cindex = get_index(pkey, pn);
1883
1884 continue;
1885 }
1886
1887 /* grab the next available node */
1888 n = get_child(pn, cindex);
1889 if (!n)
1890 continue;
1891
1892 if (IS_TNODE(n)) {
1893 /* record pn and cindex for leaf walking */
1894 pn = n;
1895 cindex = 1ul << n->bits;
1896
1897 continue;
1898 }
1899
1900 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1901 struct fib_info *fi = fa->fa_info;
1902
1903 if (!fi || !(fi->fib_flags & RTNH_F_DEAD) ||
1904 tb->tb_id != fa->tb_id) {
1905 slen = fa->fa_slen;
1906 continue;
1907 }
1908
1909 call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL,
1910 n->key,
1911 KEYLENGTH - fa->fa_slen, fa,
1912 NULL);
1913 hlist_del_rcu(&fa->fa_list);
1914 fib_release_info(fa->fa_info);
1915 alias_free_mem_rcu(fa);
1916 found++;
1917 }
1918
1919 /* update leaf slen */
1920 n->slen = slen;
1921
1922 if (hlist_empty(&n->leaf)) {
1923 put_child_root(pn, n->key, NULL);
1924 node_free(n);
1925 }
1926 }
1927
1928 pr_debug("trie_flush found=%d\n", found);
1929 return found;
1930}
1931
1932static void fib_leaf_notify(struct net *net, struct key_vector *l,
1933 struct fib_table *tb, struct notifier_block *nb)
1934{
1935 struct fib_alias *fa;
1936
1937 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
1938 struct fib_info *fi = fa->fa_info;
1939
1940 if (!fi)
1941 continue;
1942
1943 /* local and main table can share the same trie,
1944 * so don't notify twice for the same entry.
1945 */
1946 if (tb->tb_id != fa->tb_id)
1947 continue;
1948
1949 call_fib_entry_notifier(nb, net, FIB_EVENT_ENTRY_ADD, l->key,
1950 KEYLENGTH - fa->fa_slen, fa);
1951 }
1952}
1953
1954static void fib_table_notify(struct net *net, struct fib_table *tb,
1955 struct notifier_block *nb)
1956{
1957 struct trie *t = (struct trie *)tb->tb_data;
1958 struct key_vector *l, *tp = t->kv;
1959 t_key key = 0;
1960
1961 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
1962 fib_leaf_notify(net, l, tb, nb);
1963
1964 key = l->key + 1;
1965 /* stop in case of wrap around */
1966 if (key < l->key)
1967 break;
1968 }
1969}
1970
1971void fib_notify(struct net *net, struct notifier_block *nb)
1972{
1973 unsigned int h;
1974
1975 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
1976 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
1977 struct fib_table *tb;
1978
1979 hlist_for_each_entry_rcu(tb, head, tb_hlist)
1980 fib_table_notify(net, tb, nb);
1981 }
1982}
1983
1984static void __trie_free_rcu(struct rcu_head *head)
1985{
1986 struct fib_table *tb = container_of(head, struct fib_table, rcu);
1987#ifdef CONFIG_IP_FIB_TRIE_STATS
1988 struct trie *t = (struct trie *)tb->tb_data;
1989
1990 if (tb->tb_data == tb->__data)
1991 free_percpu(t->stats);
1992#endif /* CONFIG_IP_FIB_TRIE_STATS */
1993 kfree(tb);
1994}
1995
1996void fib_free_table(struct fib_table *tb)
1997{
1998 call_rcu(&tb->rcu, __trie_free_rcu);
1999}
2000
2001static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb,
2002 struct sk_buff *skb, struct netlink_callback *cb)
2003{
2004 __be32 xkey = htonl(l->key);
2005 struct fib_alias *fa;
2006 int i, s_i;
2007
2008 s_i = cb->args[4];
2009 i = 0;
2010
2011 /* rcu_read_lock is hold by caller */
2012 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2013 int err;
2014
2015 if (i < s_i) {
2016 i++;
2017 continue;
2018 }
2019
2020 if (tb->tb_id != fa->tb_id) {
2021 i++;
2022 continue;
2023 }
2024
2025 err = fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
2026 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2027 tb->tb_id, fa->fa_type,
2028 xkey, KEYLENGTH - fa->fa_slen,
2029 fa->fa_tos, fa->fa_info, NLM_F_MULTI);
2030 if (err < 0) {
2031 cb->args[4] = i;
2032 return err;
2033 }
2034 i++;
2035 }
2036
2037 cb->args[4] = i;
2038 return skb->len;
2039}
2040
2041/* rcu_read_lock needs to be hold by caller from readside */
2042int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
2043 struct netlink_callback *cb)
2044{
2045 struct trie *t = (struct trie *)tb->tb_data;
2046 struct key_vector *l, *tp = t->kv;
2047 /* Dump starting at last key.
2048 * Note: 0.0.0.0/0 (ie default) is first key.
2049 */
2050 int count = cb->args[2];
2051 t_key key = cb->args[3];
2052
2053 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
2054 int err;
2055
2056 err = fn_trie_dump_leaf(l, tb, skb, cb);
2057 if (err < 0) {
2058 cb->args[3] = key;
2059 cb->args[2] = count;
2060 return err;
2061 }
2062
2063 ++count;
2064 key = l->key + 1;
2065
2066 memset(&cb->args[4], 0,
2067 sizeof(cb->args) - 4*sizeof(cb->args[0]));
2068
2069 /* stop loop if key wrapped back to 0 */
2070 if (key < l->key)
2071 break;
2072 }
2073
2074 cb->args[3] = key;
2075 cb->args[2] = count;
2076
2077 return skb->len;
2078}
2079
2080void __init fib_trie_init(void)
2081{
2082 fn_alias_kmem = kmem_cache_create("ip_fib_alias",
2083 sizeof(struct fib_alias),
2084 0, SLAB_PANIC, NULL);
2085
2086 trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
2087 LEAF_SIZE,
2088 0, SLAB_PANIC, NULL);
2089}
2090
2091struct fib_table *fib_trie_table(u32 id, struct fib_table *alias)
2092{
2093 struct fib_table *tb;
2094 struct trie *t;
2095 size_t sz = sizeof(*tb);
2096
2097 if (!alias)
2098 sz += sizeof(struct trie);
2099
2100 tb = kzalloc(sz, GFP_KERNEL);
2101 if (!tb)
2102 return NULL;
2103
2104 tb->tb_id = id;
2105 tb->tb_num_default = 0;
2106 tb->tb_data = (alias ? alias->__data : tb->__data);
2107
2108 if (alias)
2109 return tb;
2110
2111 t = (struct trie *) tb->tb_data;
2112 t->kv[0].pos = KEYLENGTH;
2113 t->kv[0].slen = KEYLENGTH;
2114#ifdef CONFIG_IP_FIB_TRIE_STATS
2115 t->stats = alloc_percpu(struct trie_use_stats);
2116 if (!t->stats) {
2117 kfree(tb);
2118 tb = NULL;
2119 }
2120#endif
2121
2122 return tb;
2123}
2124
2125#ifdef CONFIG_PROC_FS
2126/* Depth first Trie walk iterator */
2127struct fib_trie_iter {
2128 struct seq_net_private p;
2129 struct fib_table *tb;
2130 struct key_vector *tnode;
2131 unsigned int index;
2132 unsigned int depth;
2133};
2134
2135static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter)
2136{
2137 unsigned long cindex = iter->index;
2138 struct key_vector *pn = iter->tnode;
2139 t_key pkey;
2140
2141 pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
2142 iter->tnode, iter->index, iter->depth);
2143
2144 while (!IS_TRIE(pn)) {
2145 while (cindex < child_length(pn)) {
2146 struct key_vector *n = get_child_rcu(pn, cindex++);
2147
2148 if (!n)
2149 continue;
2150
2151 if (IS_LEAF(n)) {
2152 iter->tnode = pn;
2153 iter->index = cindex;
2154 } else {
2155 /* push down one level */
2156 iter->tnode = n;
2157 iter->index = 0;
2158 ++iter->depth;
2159 }
2160
2161 return n;
2162 }
2163
2164 /* Current node exhausted, pop back up */
2165 pkey = pn->key;
2166 pn = node_parent_rcu(pn);
2167 cindex = get_index(pkey, pn) + 1;
2168 --iter->depth;
2169 }
2170
2171 /* record root node so further searches know we are done */
2172 iter->tnode = pn;
2173 iter->index = 0;
2174
2175 return NULL;
2176}
2177
2178static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter,
2179 struct trie *t)
2180{
2181 struct key_vector *n, *pn;
2182
2183 if (!t)
2184 return NULL;
2185
2186 pn = t->kv;
2187 n = rcu_dereference(pn->tnode[0]);
2188 if (!n)
2189 return NULL;
2190
2191 if (IS_TNODE(n)) {
2192 iter->tnode = n;
2193 iter->index = 0;
2194 iter->depth = 1;
2195 } else {
2196 iter->tnode = pn;
2197 iter->index = 0;
2198 iter->depth = 0;
2199 }
2200
2201 return n;
2202}
2203
2204static void trie_collect_stats(struct trie *t, struct trie_stat *s)
2205{
2206 struct key_vector *n;
2207 struct fib_trie_iter iter;
2208
2209 memset(s, 0, sizeof(*s));
2210
2211 rcu_read_lock();
2212 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) {
2213 if (IS_LEAF(n)) {
2214 struct fib_alias *fa;
2215
2216 s->leaves++;
2217 s->totdepth += iter.depth;
2218 if (iter.depth > s->maxdepth)
2219 s->maxdepth = iter.depth;
2220
2221 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list)
2222 ++s->prefixes;
2223 } else {
2224 s->tnodes++;
2225 if (n->bits < MAX_STAT_DEPTH)
2226 s->nodesizes[n->bits]++;
2227 s->nullpointers += tn_info(n)->empty_children;
2228 }
2229 }
2230 rcu_read_unlock();
2231}
2232
2233/*
2234 * This outputs /proc/net/fib_triestats
2235 */
2236static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
2237{
2238 unsigned int i, max, pointers, bytes, avdepth;
2239
2240 if (stat->leaves)
2241 avdepth = stat->totdepth*100 / stat->leaves;
2242 else
2243 avdepth = 0;
2244
2245 seq_printf(seq, "\tAver depth: %u.%02d\n",
2246 avdepth / 100, avdepth % 100);
2247 seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth);
2248
2249 seq_printf(seq, "\tLeaves: %u\n", stat->leaves);
2250 bytes = LEAF_SIZE * stat->leaves;
2251
2252 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes);
2253 bytes += sizeof(struct fib_alias) * stat->prefixes;
2254
2255 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);
2256 bytes += TNODE_SIZE(0) * stat->tnodes;
2257
2258 max = MAX_STAT_DEPTH;
2259 while (max > 0 && stat->nodesizes[max-1] == 0)
2260 max--;
2261
2262 pointers = 0;
2263 for (i = 1; i < max; i++)
2264 if (stat->nodesizes[i] != 0) {
2265 seq_printf(seq, " %u: %u", i, stat->nodesizes[i]);
2266 pointers += (1<<i) * stat->nodesizes[i];
2267 }
2268 seq_putc(seq, '\n');
2269 seq_printf(seq, "\tPointers: %u\n", pointers);
2270
2271 bytes += sizeof(struct key_vector *) * pointers;
2272 seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers);
2273 seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024);
2274}
2275
2276#ifdef CONFIG_IP_FIB_TRIE_STATS
2277static void trie_show_usage(struct seq_file *seq,
2278 const struct trie_use_stats __percpu *stats)
2279{
2280 struct trie_use_stats s = { 0 };
2281 int cpu;
2282
2283 /* loop through all of the CPUs and gather up the stats */
2284 for_each_possible_cpu(cpu) {
2285 const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu);
2286
2287 s.gets += pcpu->gets;
2288 s.backtrack += pcpu->backtrack;
2289 s.semantic_match_passed += pcpu->semantic_match_passed;
2290 s.semantic_match_miss += pcpu->semantic_match_miss;
2291 s.null_node_hit += pcpu->null_node_hit;
2292 s.resize_node_skipped += pcpu->resize_node_skipped;
2293 }
2294
2295 seq_printf(seq, "\nCounters:\n---------\n");
2296 seq_printf(seq, "gets = %u\n", s.gets);
2297 seq_printf(seq, "backtracks = %u\n", s.backtrack);
2298 seq_printf(seq, "semantic match passed = %u\n",
2299 s.semantic_match_passed);
2300 seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss);
2301 seq_printf(seq, "null node hit= %u\n", s.null_node_hit);
2302 seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped);
2303}
2304#endif /* CONFIG_IP_FIB_TRIE_STATS */
2305
2306static void fib_table_print(struct seq_file *seq, struct fib_table *tb)
2307{
2308 if (tb->tb_id == RT_TABLE_LOCAL)
2309 seq_puts(seq, "Local:\n");
2310 else if (tb->tb_id == RT_TABLE_MAIN)
2311 seq_puts(seq, "Main:\n");
2312 else
2313 seq_printf(seq, "Id %d:\n", tb->tb_id);
2314}
2315
2316
2317static int fib_triestat_seq_show(struct seq_file *seq, void *v)
2318{
2319 struct net *net = (struct net *)seq->private;
2320 unsigned int h;
2321
2322 seq_printf(seq,
2323 "Basic info: size of leaf:"
2324 " %zd bytes, size of tnode: %zd bytes.\n",
2325 LEAF_SIZE, TNODE_SIZE(0));
2326
2327 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2328 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2329 struct fib_table *tb;
2330
2331 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2332 struct trie *t = (struct trie *) tb->tb_data;
2333 struct trie_stat stat;
2334
2335 if (!t)
2336 continue;
2337
2338 fib_table_print(seq, tb);
2339
2340 trie_collect_stats(t, &stat);
2341 trie_show_stats(seq, &stat);
2342#ifdef CONFIG_IP_FIB_TRIE_STATS
2343 trie_show_usage(seq, t->stats);
2344#endif
2345 }
2346 }
2347
2348 return 0;
2349}
2350
2351static int fib_triestat_seq_open(struct inode *inode, struct file *file)
2352{
2353 return single_open_net(inode, file, fib_triestat_seq_show);
2354}
2355
2356static const struct file_operations fib_triestat_fops = {
2357 .open = fib_triestat_seq_open,
2358 .read = seq_read,
2359 .llseek = seq_lseek,
2360 .release = single_release_net,
2361};
2362
2363static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos)
2364{
2365 struct fib_trie_iter *iter = seq->private;
2366 struct net *net = seq_file_net(seq);
2367 loff_t idx = 0;
2368 unsigned int h;
2369
2370 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2371 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2372 struct fib_table *tb;
2373
2374 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2375 struct key_vector *n;
2376
2377 for (n = fib_trie_get_first(iter,
2378 (struct trie *) tb->tb_data);
2379 n; n = fib_trie_get_next(iter))
2380 if (pos == idx++) {
2381 iter->tb = tb;
2382 return n;
2383 }
2384 }
2385 }
2386
2387 return NULL;
2388}
2389
2390static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
2391 __acquires(RCU)
2392{
2393 rcu_read_lock();
2394 return fib_trie_get_idx(seq, *pos);
2395}
2396
2397static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2398{
2399 struct fib_trie_iter *iter = seq->private;
2400 struct net *net = seq_file_net(seq);
2401 struct fib_table *tb = iter->tb;
2402 struct hlist_node *tb_node;
2403 unsigned int h;
2404 struct key_vector *n;
2405
2406 ++*pos;
2407 /* next node in same table */
2408 n = fib_trie_get_next(iter);
2409 if (n)
2410 return n;
2411
2412 /* walk rest of this hash chain */
2413 h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);
2414 while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) {
2415 tb = hlist_entry(tb_node, struct fib_table, tb_hlist);
2416 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2417 if (n)
2418 goto found;
2419 }
2420
2421 /* new hash chain */
2422 while (++h < FIB_TABLE_HASHSZ) {
2423 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2424 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2425 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2426 if (n)
2427 goto found;
2428 }
2429 }
2430 return NULL;
2431
2432found:
2433 iter->tb = tb;
2434 return n;
2435}
2436
2437static void fib_trie_seq_stop(struct seq_file *seq, void *v)
2438 __releases(RCU)
2439{
2440 rcu_read_unlock();
2441}
2442
2443static void seq_indent(struct seq_file *seq, int n)
2444{
2445 while (n-- > 0)
2446 seq_puts(seq, " ");
2447}
2448
2449static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
2450{
2451 switch (s) {
2452 case RT_SCOPE_UNIVERSE: return "universe";
2453 case RT_SCOPE_SITE: return "site";
2454 case RT_SCOPE_LINK: return "link";
2455 case RT_SCOPE_HOST: return "host";
2456 case RT_SCOPE_NOWHERE: return "nowhere";
2457 default:
2458 snprintf(buf, len, "scope=%d", s);
2459 return buf;
2460 }
2461}
2462
2463static const char *const rtn_type_names[__RTN_MAX] = {
2464 [RTN_UNSPEC] = "UNSPEC",
2465 [RTN_UNICAST] = "UNICAST",
2466 [RTN_LOCAL] = "LOCAL",
2467 [RTN_BROADCAST] = "BROADCAST",
2468 [RTN_ANYCAST] = "ANYCAST",
2469 [RTN_MULTICAST] = "MULTICAST",
2470 [RTN_BLACKHOLE] = "BLACKHOLE",
2471 [RTN_UNREACHABLE] = "UNREACHABLE",
2472 [RTN_PROHIBIT] = "PROHIBIT",
2473 [RTN_THROW] = "THROW",
2474 [RTN_NAT] = "NAT",
2475 [RTN_XRESOLVE] = "XRESOLVE",
2476};
2477
2478static inline const char *rtn_type(char *buf, size_t len, unsigned int t)
2479{
2480 if (t < __RTN_MAX && rtn_type_names[t])
2481 return rtn_type_names[t];
2482 snprintf(buf, len, "type %u", t);
2483 return buf;
2484}
2485
2486/* Pretty print the trie */
2487static int fib_trie_seq_show(struct seq_file *seq, void *v)
2488{
2489 const struct fib_trie_iter *iter = seq->private;
2490 struct key_vector *n = v;
2491
2492 if (IS_TRIE(node_parent_rcu(n)))
2493 fib_table_print(seq, iter->tb);
2494
2495 if (IS_TNODE(n)) {
2496 __be32 prf = htonl(n->key);
2497
2498 seq_indent(seq, iter->depth-1);
2499 seq_printf(seq, " +-- %pI4/%zu %u %u %u\n",
2500 &prf, KEYLENGTH - n->pos - n->bits, n->bits,
2501 tn_info(n)->full_children,
2502 tn_info(n)->empty_children);
2503 } else {
2504 __be32 val = htonl(n->key);
2505 struct fib_alias *fa;
2506
2507 seq_indent(seq, iter->depth);
2508 seq_printf(seq, " |-- %pI4\n", &val);
2509
2510 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
2511 char buf1[32], buf2[32];
2512
2513 seq_indent(seq, iter->depth + 1);
2514 seq_printf(seq, " /%zu %s %s",
2515 KEYLENGTH - fa->fa_slen,
2516 rtn_scope(buf1, sizeof(buf1),
2517 fa->fa_info->fib_scope),
2518 rtn_type(buf2, sizeof(buf2),
2519 fa->fa_type));
2520 if (fa->fa_tos)
2521 seq_printf(seq, " tos=%d", fa->fa_tos);
2522 seq_putc(seq, '\n');
2523 }
2524 }
2525
2526 return 0;
2527}
2528
2529static const struct seq_operations fib_trie_seq_ops = {
2530 .start = fib_trie_seq_start,
2531 .next = fib_trie_seq_next,
2532 .stop = fib_trie_seq_stop,
2533 .show = fib_trie_seq_show,
2534};
2535
2536static int fib_trie_seq_open(struct inode *inode, struct file *file)
2537{
2538 return seq_open_net(inode, file, &fib_trie_seq_ops,
2539 sizeof(struct fib_trie_iter));
2540}
2541
2542static const struct file_operations fib_trie_fops = {
2543 .open = fib_trie_seq_open,
2544 .read = seq_read,
2545 .llseek = seq_lseek,
2546 .release = seq_release_net,
2547};
2548
2549struct fib_route_iter {
2550 struct seq_net_private p;
2551 struct fib_table *main_tb;
2552 struct key_vector *tnode;
2553 loff_t pos;
2554 t_key key;
2555};
2556
2557static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter,
2558 loff_t pos)
2559{
2560 struct key_vector *l, **tp = &iter->tnode;
2561 t_key key;
2562
2563 /* use cached location of previously found key */
2564 if (iter->pos > 0 && pos >= iter->pos) {
2565 key = iter->key;
2566 } else {
2567 iter->pos = 1;
2568 key = 0;
2569 }
2570
2571 pos -= iter->pos;
2572
2573 while ((l = leaf_walk_rcu(tp, key)) && (pos-- > 0)) {
2574 key = l->key + 1;
2575 iter->pos++;
2576 l = NULL;
2577
2578 /* handle unlikely case of a key wrap */
2579 if (!key)
2580 break;
2581 }
2582
2583 if (l)
2584 iter->key = l->key; /* remember it */
2585 else
2586 iter->pos = 0; /* forget it */
2587
2588 return l;
2589}
2590
2591static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos)
2592 __acquires(RCU)
2593{
2594 struct fib_route_iter *iter = seq->private;
2595 struct fib_table *tb;
2596 struct trie *t;
2597
2598 rcu_read_lock();
2599
2600 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
2601 if (!tb)
2602 return NULL;
2603
2604 iter->main_tb = tb;
2605 t = (struct trie *)tb->tb_data;
2606 iter->tnode = t->kv;
2607
2608 if (*pos != 0)
2609 return fib_route_get_idx(iter, *pos);
2610
2611 iter->pos = 0;
2612 iter->key = KEY_MAX;
2613
2614 return SEQ_START_TOKEN;
2615}
2616
2617static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2618{
2619 struct fib_route_iter *iter = seq->private;
2620 struct key_vector *l = NULL;
2621 t_key key = iter->key + 1;
2622
2623 ++*pos;
2624
2625 /* only allow key of 0 for start of sequence */
2626 if ((v == SEQ_START_TOKEN) || key)
2627 l = leaf_walk_rcu(&iter->tnode, key);
2628
2629 if (l) {
2630 iter->key = l->key;
2631 iter->pos++;
2632 } else {
2633 iter->pos = 0;
2634 }
2635
2636 return l;
2637}
2638
2639static void fib_route_seq_stop(struct seq_file *seq, void *v)
2640 __releases(RCU)
2641{
2642 rcu_read_unlock();
2643}
2644
2645static unsigned int fib_flag_trans(int type, __be32 mask, const struct fib_info *fi)
2646{
2647 unsigned int flags = 0;
2648
2649 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT)
2650 flags = RTF_REJECT;
2651 if (fi && fi->fib_nh->nh_gw)
2652 flags |= RTF_GATEWAY;
2653 if (mask == htonl(0xFFFFFFFF))
2654 flags |= RTF_HOST;
2655 flags |= RTF_UP;
2656 return flags;
2657}
2658
2659/*
2660 * This outputs /proc/net/route.
2661 * The format of the file is not supposed to be changed
2662 * and needs to be same as fib_hash output to avoid breaking
2663 * legacy utilities
2664 */
2665static int fib_route_seq_show(struct seq_file *seq, void *v)
2666{
2667 struct fib_route_iter *iter = seq->private;
2668 struct fib_table *tb = iter->main_tb;
2669 struct fib_alias *fa;
2670 struct key_vector *l = v;
2671 __be32 prefix;
2672
2673 if (v == SEQ_START_TOKEN) {
2674 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
2675 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
2676 "\tWindow\tIRTT");
2677 return 0;
2678 }
2679
2680 prefix = htonl(l->key);
2681
2682 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2683 const struct fib_info *fi = fa->fa_info;
2684 __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen);
2685 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);
2686
2687 if ((fa->fa_type == RTN_BROADCAST) ||
2688 (fa->fa_type == RTN_MULTICAST))
2689 continue;
2690
2691 if (fa->tb_id != tb->tb_id)
2692 continue;
2693
2694 seq_setwidth(seq, 127);
2695
2696 if (fi)
2697 seq_printf(seq,
2698 "%s\t%08X\t%08X\t%04X\t%d\t%u\t"
2699 "%d\t%08X\t%d\t%u\t%u",
2700 fi->fib_dev ? fi->fib_dev->name : "*",
2701 prefix,
2702 fi->fib_nh->nh_gw, flags, 0, 0,
2703 fi->fib_priority,
2704 mask,
2705 (fi->fib_advmss ?
2706 fi->fib_advmss + 40 : 0),
2707 fi->fib_window,
2708 fi->fib_rtt >> 3);
2709 else
2710 seq_printf(seq,
2711 "*\t%08X\t%08X\t%04X\t%d\t%u\t"
2712 "%d\t%08X\t%d\t%u\t%u",
2713 prefix, 0, flags, 0, 0, 0,
2714 mask, 0, 0, 0);
2715
2716 seq_pad(seq, '\n');
2717 }
2718
2719 return 0;
2720}
2721
2722static const struct seq_operations fib_route_seq_ops = {
2723 .start = fib_route_seq_start,
2724 .next = fib_route_seq_next,
2725 .stop = fib_route_seq_stop,
2726 .show = fib_route_seq_show,
2727};
2728
2729static int fib_route_seq_open(struct inode *inode, struct file *file)
2730{
2731 return seq_open_net(inode, file, &fib_route_seq_ops,
2732 sizeof(struct fib_route_iter));
2733}
2734
2735static const struct file_operations fib_route_fops = {
2736 .open = fib_route_seq_open,
2737 .read = seq_read,
2738 .llseek = seq_lseek,
2739 .release = seq_release_net,
2740};
2741
2742int __net_init fib_proc_init(struct net *net)
2743{
2744 if (!proc_create("fib_trie", 0444, net->proc_net, &fib_trie_fops))
2745 goto out1;
2746
2747 if (!proc_create("fib_triestat", 0444, net->proc_net,
2748 &fib_triestat_fops))
2749 goto out2;
2750
2751 if (!proc_create("route", 0444, net->proc_net, &fib_route_fops))
2752 goto out3;
2753
2754 return 0;
2755
2756out3:
2757 remove_proc_entry("fib_triestat", net->proc_net);
2758out2:
2759 remove_proc_entry("fib_trie", net->proc_net);
2760out1:
2761 return -ENOMEM;
2762}
2763
2764void __net_exit fib_proc_exit(struct net *net)
2765{
2766 remove_proc_entry("fib_trie", net->proc_net);
2767 remove_proc_entry("fib_triestat", net->proc_net);
2768 remove_proc_entry("route", net->proc_net);
2769}
2770
2771#endif /* CONFIG_PROC_FS */
1/*
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.
6 *
7 * Robert Olsson <robert.olsson@its.uu.se> Uppsala Universitet
8 * & Swedish University of Agricultural Sciences.
9 *
10 * Jens Laas <jens.laas@data.slu.se> Swedish University of
11 * Agricultural Sciences.
12 *
13 * Hans Liss <hans.liss@its.uu.se> Uppsala Universitet
14 *
15 * This work is based on the LPC-trie which is originally described in:
16 *
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/
20 *
21 *
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
24 *
25 *
26 * Code from fib_hash has been reused which includes the following header:
27 *
28 *
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.
32 *
33 * IPv4 FIB: lookup engine and maintenance routines.
34 *
35 *
36 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
37 *
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.
42 *
43 * Substantial contributions to this work comes from:
44 *
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>
49 */
50
51#define VERSION "0.409"
52
53#include <asm/uaccess.h>
54#include <linux/bitops.h>
55#include <linux/types.h>
56#include <linux/kernel.h>
57#include <linux/mm.h>
58#include <linux/string.h>
59#include <linux/socket.h>
60#include <linux/sockios.h>
61#include <linux/errno.h>
62#include <linux/in.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 <net/net_namespace.h>
77#include <net/ip.h>
78#include <net/protocol.h>
79#include <net/route.h>
80#include <net/tcp.h>
81#include <net/sock.h>
82#include <net/ip_fib.h>
83#include <net/switchdev.h>
84#include <trace/events/fib.h>
85#include "fib_lookup.h"
86
87#define MAX_STAT_DEPTH 32
88
89#define KEYLENGTH (8*sizeof(t_key))
90#define KEY_MAX ((t_key)~0)
91
92typedef unsigned int t_key;
93
94#define IS_TRIE(n) ((n)->pos >= KEYLENGTH)
95#define IS_TNODE(n) ((n)->bits)
96#define IS_LEAF(n) (!(n)->bits)
97
98struct key_vector {
99 t_key key;
100 unsigned char pos; /* 2log(KEYLENGTH) bits needed */
101 unsigned char bits; /* 2log(KEYLENGTH) bits needed */
102 unsigned char slen;
103 union {
104 /* This list pointer if valid if (pos | bits) == 0 (LEAF) */
105 struct hlist_head leaf;
106 /* This array is valid if (pos | bits) > 0 (TNODE) */
107 struct key_vector __rcu *tnode[0];
108 };
109};
110
111struct tnode {
112 struct rcu_head rcu;
113 t_key empty_children; /* KEYLENGTH bits needed */
114 t_key full_children; /* KEYLENGTH bits needed */
115 struct key_vector __rcu *parent;
116 struct key_vector kv[1];
117#define tn_bits kv[0].bits
118};
119
120#define TNODE_SIZE(n) offsetof(struct tnode, kv[0].tnode[n])
121#define LEAF_SIZE TNODE_SIZE(1)
122
123#ifdef CONFIG_IP_FIB_TRIE_STATS
124struct trie_use_stats {
125 unsigned int gets;
126 unsigned int backtrack;
127 unsigned int semantic_match_passed;
128 unsigned int semantic_match_miss;
129 unsigned int null_node_hit;
130 unsigned int resize_node_skipped;
131};
132#endif
133
134struct trie_stat {
135 unsigned int totdepth;
136 unsigned int maxdepth;
137 unsigned int tnodes;
138 unsigned int leaves;
139 unsigned int nullpointers;
140 unsigned int prefixes;
141 unsigned int nodesizes[MAX_STAT_DEPTH];
142};
143
144struct trie {
145 struct key_vector kv[1];
146#ifdef CONFIG_IP_FIB_TRIE_STATS
147 struct trie_use_stats __percpu *stats;
148#endif
149};
150
151static struct key_vector *resize(struct trie *t, struct key_vector *tn);
152static size_t tnode_free_size;
153
154/*
155 * synchronize_rcu after call_rcu for that many pages; it should be especially
156 * useful before resizing the root node with PREEMPT_NONE configs; the value was
157 * obtained experimentally, aiming to avoid visible slowdown.
158 */
159static const int sync_pages = 128;
160
161static struct kmem_cache *fn_alias_kmem __read_mostly;
162static struct kmem_cache *trie_leaf_kmem __read_mostly;
163
164static inline struct tnode *tn_info(struct key_vector *kv)
165{
166 return container_of(kv, struct tnode, kv[0]);
167}
168
169/* caller must hold RTNL */
170#define node_parent(tn) rtnl_dereference(tn_info(tn)->parent)
171#define get_child(tn, i) rtnl_dereference((tn)->tnode[i])
172
173/* caller must hold RCU read lock or RTNL */
174#define node_parent_rcu(tn) rcu_dereference_rtnl(tn_info(tn)->parent)
175#define get_child_rcu(tn, i) rcu_dereference_rtnl((tn)->tnode[i])
176
177/* wrapper for rcu_assign_pointer */
178static inline void node_set_parent(struct key_vector *n, struct key_vector *tp)
179{
180 if (n)
181 rcu_assign_pointer(tn_info(n)->parent, tp);
182}
183
184#define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER(tn_info(n)->parent, p)
185
186/* This provides us with the number of children in this node, in the case of a
187 * leaf this will return 0 meaning none of the children are accessible.
188 */
189static inline unsigned long child_length(const struct key_vector *tn)
190{
191 return (1ul << tn->bits) & ~(1ul);
192}
193
194#define get_cindex(key, kv) (((key) ^ (kv)->key) >> (kv)->pos)
195
196static inline unsigned long get_index(t_key key, struct key_vector *kv)
197{
198 unsigned long index = key ^ kv->key;
199
200 if ((BITS_PER_LONG <= KEYLENGTH) && (KEYLENGTH == kv->pos))
201 return 0;
202
203 return index >> kv->pos;
204}
205
206/* To understand this stuff, an understanding of keys and all their bits is
207 * necessary. Every node in the trie has a key associated with it, but not
208 * all of the bits in that key are significant.
209 *
210 * Consider a node 'n' and its parent 'tp'.
211 *
212 * If n is a leaf, every bit in its key is significant. Its presence is
213 * necessitated by path compression, since during a tree traversal (when
214 * searching for a leaf - unless we are doing an insertion) we will completely
215 * ignore all skipped bits we encounter. Thus we need to verify, at the end of
216 * a potentially successful search, that we have indeed been walking the
217 * correct key path.
218 *
219 * Note that we can never "miss" the correct key in the tree if present by
220 * following the wrong path. Path compression ensures that segments of the key
221 * that are the same for all keys with a given prefix are skipped, but the
222 * skipped part *is* identical for each node in the subtrie below the skipped
223 * bit! trie_insert() in this implementation takes care of that.
224 *
225 * if n is an internal node - a 'tnode' here, the various parts of its key
226 * have many different meanings.
227 *
228 * Example:
229 * _________________________________________________________________
230 * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
231 * -----------------------------------------------------------------
232 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
233 *
234 * _________________________________________________________________
235 * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
236 * -----------------------------------------------------------------
237 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
238 *
239 * tp->pos = 22
240 * tp->bits = 3
241 * n->pos = 13
242 * n->bits = 4
243 *
244 * First, let's just ignore the bits that come before the parent tp, that is
245 * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this
246 * point we do not use them for anything.
247 *
248 * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the
249 * index into the parent's child array. That is, they will be used to find
250 * 'n' among tp's children.
251 *
252 * The bits from (n->pos + n->bits) to (tn->pos - 1) - "S" - are skipped bits
253 * for the node n.
254 *
255 * All the bits we have seen so far are significant to the node n. The rest
256 * of the bits are really not needed or indeed known in n->key.
257 *
258 * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into
259 * n's child array, and will of course be different for each child.
260 *
261 * The rest of the bits, from 0 to (n->pos + n->bits), are completely unknown
262 * at this point.
263 */
264
265static const int halve_threshold = 25;
266static const int inflate_threshold = 50;
267static const int halve_threshold_root = 15;
268static const int inflate_threshold_root = 30;
269
270static void __alias_free_mem(struct rcu_head *head)
271{
272 struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
273 kmem_cache_free(fn_alias_kmem, fa);
274}
275
276static inline void alias_free_mem_rcu(struct fib_alias *fa)
277{
278 call_rcu(&fa->rcu, __alias_free_mem);
279}
280
281#define TNODE_KMALLOC_MAX \
282 ilog2((PAGE_SIZE - TNODE_SIZE(0)) / sizeof(struct key_vector *))
283#define TNODE_VMALLOC_MAX \
284 ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *))
285
286static void __node_free_rcu(struct rcu_head *head)
287{
288 struct tnode *n = container_of(head, struct tnode, rcu);
289
290 if (!n->tn_bits)
291 kmem_cache_free(trie_leaf_kmem, n);
292 else
293 kvfree(n);
294}
295
296#define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu)
297
298static struct tnode *tnode_alloc(int bits)
299{
300 size_t size;
301
302 /* verify bits is within bounds */
303 if (bits > TNODE_VMALLOC_MAX)
304 return NULL;
305
306 /* determine size and verify it is non-zero and didn't overflow */
307 size = TNODE_SIZE(1ul << bits);
308
309 if (size <= PAGE_SIZE)
310 return kzalloc(size, GFP_KERNEL);
311 else
312 return vzalloc(size);
313}
314
315static inline void empty_child_inc(struct key_vector *n)
316{
317 ++tn_info(n)->empty_children ? : ++tn_info(n)->full_children;
318}
319
320static inline void empty_child_dec(struct key_vector *n)
321{
322 tn_info(n)->empty_children-- ? : tn_info(n)->full_children--;
323}
324
325static struct key_vector *leaf_new(t_key key, struct fib_alias *fa)
326{
327 struct key_vector *l;
328 struct tnode *kv;
329
330 kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
331 if (!kv)
332 return NULL;
333
334 /* initialize key vector */
335 l = kv->kv;
336 l->key = key;
337 l->pos = 0;
338 l->bits = 0;
339 l->slen = fa->fa_slen;
340
341 /* link leaf to fib alias */
342 INIT_HLIST_HEAD(&l->leaf);
343 hlist_add_head(&fa->fa_list, &l->leaf);
344
345 return l;
346}
347
348static struct key_vector *tnode_new(t_key key, int pos, int bits)
349{
350 unsigned int shift = pos + bits;
351 struct key_vector *tn;
352 struct tnode *tnode;
353
354 /* verify bits and pos their msb bits clear and values are valid */
355 BUG_ON(!bits || (shift > KEYLENGTH));
356
357 tnode = tnode_alloc(bits);
358 if (!tnode)
359 return NULL;
360
361 pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0),
362 sizeof(struct key_vector *) << bits);
363
364 if (bits == KEYLENGTH)
365 tnode->full_children = 1;
366 else
367 tnode->empty_children = 1ul << bits;
368
369 tn = tnode->kv;
370 tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
371 tn->pos = pos;
372 tn->bits = bits;
373 tn->slen = pos;
374
375 return tn;
376}
377
378/* Check whether a tnode 'n' is "full", i.e. it is an internal node
379 * and no bits are skipped. See discussion in dyntree paper p. 6
380 */
381static inline int tnode_full(struct key_vector *tn, struct key_vector *n)
382{
383 return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n);
384}
385
386/* Add a child at position i overwriting the old value.
387 * Update the value of full_children and empty_children.
388 */
389static void put_child(struct key_vector *tn, unsigned long i,
390 struct key_vector *n)
391{
392 struct key_vector *chi = get_child(tn, i);
393 int isfull, wasfull;
394
395 BUG_ON(i >= child_length(tn));
396
397 /* update emptyChildren, overflow into fullChildren */
398 if (!n && chi)
399 empty_child_inc(tn);
400 if (n && !chi)
401 empty_child_dec(tn);
402
403 /* update fullChildren */
404 wasfull = tnode_full(tn, chi);
405 isfull = tnode_full(tn, n);
406
407 if (wasfull && !isfull)
408 tn_info(tn)->full_children--;
409 else if (!wasfull && isfull)
410 tn_info(tn)->full_children++;
411
412 if (n && (tn->slen < n->slen))
413 tn->slen = n->slen;
414
415 rcu_assign_pointer(tn->tnode[i], n);
416}
417
418static void update_children(struct key_vector *tn)
419{
420 unsigned long i;
421
422 /* update all of the child parent pointers */
423 for (i = child_length(tn); i;) {
424 struct key_vector *inode = get_child(tn, --i);
425
426 if (!inode)
427 continue;
428
429 /* Either update the children of a tnode that
430 * already belongs to us or update the child
431 * to point to ourselves.
432 */
433 if (node_parent(inode) == tn)
434 update_children(inode);
435 else
436 node_set_parent(inode, tn);
437 }
438}
439
440static inline void put_child_root(struct key_vector *tp, t_key key,
441 struct key_vector *n)
442{
443 if (IS_TRIE(tp))
444 rcu_assign_pointer(tp->tnode[0], n);
445 else
446 put_child(tp, get_index(key, tp), n);
447}
448
449static inline void tnode_free_init(struct key_vector *tn)
450{
451 tn_info(tn)->rcu.next = NULL;
452}
453
454static inline void tnode_free_append(struct key_vector *tn,
455 struct key_vector *n)
456{
457 tn_info(n)->rcu.next = tn_info(tn)->rcu.next;
458 tn_info(tn)->rcu.next = &tn_info(n)->rcu;
459}
460
461static void tnode_free(struct key_vector *tn)
462{
463 struct callback_head *head = &tn_info(tn)->rcu;
464
465 while (head) {
466 head = head->next;
467 tnode_free_size += TNODE_SIZE(1ul << tn->bits);
468 node_free(tn);
469
470 tn = container_of(head, struct tnode, rcu)->kv;
471 }
472
473 if (tnode_free_size >= PAGE_SIZE * sync_pages) {
474 tnode_free_size = 0;
475 synchronize_rcu();
476 }
477}
478
479static struct key_vector *replace(struct trie *t,
480 struct key_vector *oldtnode,
481 struct key_vector *tn)
482{
483 struct key_vector *tp = node_parent(oldtnode);
484 unsigned long i;
485
486 /* setup the parent pointer out of and back into this node */
487 NODE_INIT_PARENT(tn, tp);
488 put_child_root(tp, tn->key, tn);
489
490 /* update all of the child parent pointers */
491 update_children(tn);
492
493 /* all pointers should be clean so we are done */
494 tnode_free(oldtnode);
495
496 /* resize children now that oldtnode is freed */
497 for (i = child_length(tn); i;) {
498 struct key_vector *inode = get_child(tn, --i);
499
500 /* resize child node */
501 if (tnode_full(tn, inode))
502 tn = resize(t, inode);
503 }
504
505 return tp;
506}
507
508static struct key_vector *inflate(struct trie *t,
509 struct key_vector *oldtnode)
510{
511 struct key_vector *tn;
512 unsigned long i;
513 t_key m;
514
515 pr_debug("In inflate\n");
516
517 tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1);
518 if (!tn)
519 goto notnode;
520
521 /* prepare oldtnode to be freed */
522 tnode_free_init(oldtnode);
523
524 /* Assemble all of the pointers in our cluster, in this case that
525 * represents all of the pointers out of our allocated nodes that
526 * point to existing tnodes and the links between our allocated
527 * nodes.
528 */
529 for (i = child_length(oldtnode), m = 1u << tn->pos; i;) {
530 struct key_vector *inode = get_child(oldtnode, --i);
531 struct key_vector *node0, *node1;
532 unsigned long j, k;
533
534 /* An empty child */
535 if (!inode)
536 continue;
537
538 /* A leaf or an internal node with skipped bits */
539 if (!tnode_full(oldtnode, inode)) {
540 put_child(tn, get_index(inode->key, tn), inode);
541 continue;
542 }
543
544 /* drop the node in the old tnode free list */
545 tnode_free_append(oldtnode, inode);
546
547 /* An internal node with two children */
548 if (inode->bits == 1) {
549 put_child(tn, 2 * i + 1, get_child(inode, 1));
550 put_child(tn, 2 * i, get_child(inode, 0));
551 continue;
552 }
553
554 /* We will replace this node 'inode' with two new
555 * ones, 'node0' and 'node1', each with half of the
556 * original children. The two new nodes will have
557 * a position one bit further down the key and this
558 * means that the "significant" part of their keys
559 * (see the discussion near the top of this file)
560 * will differ by one bit, which will be "0" in
561 * node0's key and "1" in node1's key. Since we are
562 * moving the key position by one step, the bit that
563 * we are moving away from - the bit at position
564 * (tn->pos) - is the one that will differ between
565 * node0 and node1. So... we synthesize that bit in the
566 * two new keys.
567 */
568 node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1);
569 if (!node1)
570 goto nomem;
571 node0 = tnode_new(inode->key, inode->pos, inode->bits - 1);
572
573 tnode_free_append(tn, node1);
574 if (!node0)
575 goto nomem;
576 tnode_free_append(tn, node0);
577
578 /* populate child pointers in new nodes */
579 for (k = child_length(inode), j = k / 2; j;) {
580 put_child(node1, --j, get_child(inode, --k));
581 put_child(node0, j, get_child(inode, j));
582 put_child(node1, --j, get_child(inode, --k));
583 put_child(node0, j, get_child(inode, j));
584 }
585
586 /* link new nodes to parent */
587 NODE_INIT_PARENT(node1, tn);
588 NODE_INIT_PARENT(node0, tn);
589
590 /* link parent to nodes */
591 put_child(tn, 2 * i + 1, node1);
592 put_child(tn, 2 * i, node0);
593 }
594
595 /* setup the parent pointers into and out of this node */
596 return replace(t, oldtnode, tn);
597nomem:
598 /* all pointers should be clean so we are done */
599 tnode_free(tn);
600notnode:
601 return NULL;
602}
603
604static struct key_vector *halve(struct trie *t,
605 struct key_vector *oldtnode)
606{
607 struct key_vector *tn;
608 unsigned long i;
609
610 pr_debug("In halve\n");
611
612 tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1);
613 if (!tn)
614 goto notnode;
615
616 /* prepare oldtnode to be freed */
617 tnode_free_init(oldtnode);
618
619 /* Assemble all of the pointers in our cluster, in this case that
620 * represents all of the pointers out of our allocated nodes that
621 * point to existing tnodes and the links between our allocated
622 * nodes.
623 */
624 for (i = child_length(oldtnode); i;) {
625 struct key_vector *node1 = get_child(oldtnode, --i);
626 struct key_vector *node0 = get_child(oldtnode, --i);
627 struct key_vector *inode;
628
629 /* At least one of the children is empty */
630 if (!node1 || !node0) {
631 put_child(tn, i / 2, node1 ? : node0);
632 continue;
633 }
634
635 /* Two nonempty children */
636 inode = tnode_new(node0->key, oldtnode->pos, 1);
637 if (!inode)
638 goto nomem;
639 tnode_free_append(tn, inode);
640
641 /* initialize pointers out of node */
642 put_child(inode, 1, node1);
643 put_child(inode, 0, node0);
644 NODE_INIT_PARENT(inode, tn);
645
646 /* link parent to node */
647 put_child(tn, i / 2, inode);
648 }
649
650 /* setup the parent pointers into and out of this node */
651 return replace(t, oldtnode, tn);
652nomem:
653 /* all pointers should be clean so we are done */
654 tnode_free(tn);
655notnode:
656 return NULL;
657}
658
659static struct key_vector *collapse(struct trie *t,
660 struct key_vector *oldtnode)
661{
662 struct key_vector *n, *tp;
663 unsigned long i;
664
665 /* scan the tnode looking for that one child that might still exist */
666 for (n = NULL, i = child_length(oldtnode); !n && i;)
667 n = get_child(oldtnode, --i);
668
669 /* compress one level */
670 tp = node_parent(oldtnode);
671 put_child_root(tp, oldtnode->key, n);
672 node_set_parent(n, tp);
673
674 /* drop dead node */
675 node_free(oldtnode);
676
677 return tp;
678}
679
680static unsigned char update_suffix(struct key_vector *tn)
681{
682 unsigned char slen = tn->pos;
683 unsigned long stride, i;
684
685 /* search though the list of children looking for nodes that might
686 * have a suffix greater than the one we currently have. This is
687 * why we start with a stride of 2 since a stride of 1 would
688 * represent the nodes with suffix length equal to tn->pos
689 */
690 for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) {
691 struct key_vector *n = get_child(tn, i);
692
693 if (!n || (n->slen <= slen))
694 continue;
695
696 /* update stride and slen based on new value */
697 stride <<= (n->slen - slen);
698 slen = n->slen;
699 i &= ~(stride - 1);
700
701 /* if slen covers all but the last bit we can stop here
702 * there will be nothing longer than that since only node
703 * 0 and 1 << (bits - 1) could have that as their suffix
704 * length.
705 */
706 if ((slen + 1) >= (tn->pos + tn->bits))
707 break;
708 }
709
710 tn->slen = slen;
711
712 return slen;
713}
714
715/* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
716 * the Helsinki University of Technology and Matti Tikkanen of Nokia
717 * Telecommunications, page 6:
718 * "A node is doubled if the ratio of non-empty children to all
719 * children in the *doubled* node is at least 'high'."
720 *
721 * 'high' in this instance is the variable 'inflate_threshold'. It
722 * is expressed as a percentage, so we multiply it with
723 * child_length() and instead of multiplying by 2 (since the
724 * child array will be doubled by inflate()) and multiplying
725 * the left-hand side by 100 (to handle the percentage thing) we
726 * multiply the left-hand side by 50.
727 *
728 * The left-hand side may look a bit weird: child_length(tn)
729 * - tn->empty_children is of course the number of non-null children
730 * in the current node. tn->full_children is the number of "full"
731 * children, that is non-null tnodes with a skip value of 0.
732 * All of those will be doubled in the resulting inflated tnode, so
733 * we just count them one extra time here.
734 *
735 * A clearer way to write this would be:
736 *
737 * to_be_doubled = tn->full_children;
738 * not_to_be_doubled = child_length(tn) - tn->empty_children -
739 * tn->full_children;
740 *
741 * new_child_length = child_length(tn) * 2;
742 *
743 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
744 * new_child_length;
745 * if (new_fill_factor >= inflate_threshold)
746 *
747 * ...and so on, tho it would mess up the while () loop.
748 *
749 * anyway,
750 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
751 * inflate_threshold
752 *
753 * avoid a division:
754 * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
755 * inflate_threshold * new_child_length
756 *
757 * expand not_to_be_doubled and to_be_doubled, and shorten:
758 * 100 * (child_length(tn) - tn->empty_children +
759 * tn->full_children) >= inflate_threshold * new_child_length
760 *
761 * expand new_child_length:
762 * 100 * (child_length(tn) - tn->empty_children +
763 * tn->full_children) >=
764 * inflate_threshold * child_length(tn) * 2
765 *
766 * shorten again:
767 * 50 * (tn->full_children + child_length(tn) -
768 * tn->empty_children) >= inflate_threshold *
769 * child_length(tn)
770 *
771 */
772static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn)
773{
774 unsigned long used = child_length(tn);
775 unsigned long threshold = used;
776
777 /* Keep root node larger */
778 threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold;
779 used -= tn_info(tn)->empty_children;
780 used += tn_info(tn)->full_children;
781
782 /* if bits == KEYLENGTH then pos = 0, and will fail below */
783
784 return (used > 1) && tn->pos && ((50 * used) >= threshold);
785}
786
787static inline bool should_halve(struct key_vector *tp, struct key_vector *tn)
788{
789 unsigned long used = child_length(tn);
790 unsigned long threshold = used;
791
792 /* Keep root node larger */
793 threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold;
794 used -= tn_info(tn)->empty_children;
795
796 /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */
797
798 return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold);
799}
800
801static inline bool should_collapse(struct key_vector *tn)
802{
803 unsigned long used = child_length(tn);
804
805 used -= tn_info(tn)->empty_children;
806
807 /* account for bits == KEYLENGTH case */
808 if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children)
809 used -= KEY_MAX;
810
811 /* One child or none, time to drop us from the trie */
812 return used < 2;
813}
814
815#define MAX_WORK 10
816static struct key_vector *resize(struct trie *t, struct key_vector *tn)
817{
818#ifdef CONFIG_IP_FIB_TRIE_STATS
819 struct trie_use_stats __percpu *stats = t->stats;
820#endif
821 struct key_vector *tp = node_parent(tn);
822 unsigned long cindex = get_index(tn->key, tp);
823 int max_work = MAX_WORK;
824
825 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
826 tn, inflate_threshold, halve_threshold);
827
828 /* track the tnode via the pointer from the parent instead of
829 * doing it ourselves. This way we can let RCU fully do its
830 * thing without us interfering
831 */
832 BUG_ON(tn != get_child(tp, cindex));
833
834 /* Double as long as the resulting node has a number of
835 * nonempty nodes that are above the threshold.
836 */
837 while (should_inflate(tp, tn) && max_work) {
838 tp = inflate(t, tn);
839 if (!tp) {
840#ifdef CONFIG_IP_FIB_TRIE_STATS
841 this_cpu_inc(stats->resize_node_skipped);
842#endif
843 break;
844 }
845
846 max_work--;
847 tn = get_child(tp, cindex);
848 }
849
850 /* update parent in case inflate failed */
851 tp = node_parent(tn);
852
853 /* Return if at least one inflate is run */
854 if (max_work != MAX_WORK)
855 return tp;
856
857 /* Halve as long as the number of empty children in this
858 * node is above threshold.
859 */
860 while (should_halve(tp, tn) && max_work) {
861 tp = halve(t, tn);
862 if (!tp) {
863#ifdef CONFIG_IP_FIB_TRIE_STATS
864 this_cpu_inc(stats->resize_node_skipped);
865#endif
866 break;
867 }
868
869 max_work--;
870 tn = get_child(tp, cindex);
871 }
872
873 /* Only one child remains */
874 if (should_collapse(tn))
875 return collapse(t, tn);
876
877 /* update parent in case halve failed */
878 tp = node_parent(tn);
879
880 /* Return if at least one deflate was run */
881 if (max_work != MAX_WORK)
882 return tp;
883
884 /* push the suffix length to the parent node */
885 if (tn->slen > tn->pos) {
886 unsigned char slen = update_suffix(tn);
887
888 if (slen > tp->slen)
889 tp->slen = slen;
890 }
891
892 return tp;
893}
894
895static void leaf_pull_suffix(struct key_vector *tp, struct key_vector *l)
896{
897 while ((tp->slen > tp->pos) && (tp->slen > l->slen)) {
898 if (update_suffix(tp) > l->slen)
899 break;
900 tp = node_parent(tp);
901 }
902}
903
904static void leaf_push_suffix(struct key_vector *tn, struct key_vector *l)
905{
906 /* if this is a new leaf then tn will be NULL and we can sort
907 * out parent suffix lengths as a part of trie_rebalance
908 */
909 while (tn->slen < l->slen) {
910 tn->slen = l->slen;
911 tn = node_parent(tn);
912 }
913}
914
915/* rcu_read_lock needs to be hold by caller from readside */
916static struct key_vector *fib_find_node(struct trie *t,
917 struct key_vector **tp, u32 key)
918{
919 struct key_vector *pn, *n = t->kv;
920 unsigned long index = 0;
921
922 do {
923 pn = n;
924 n = get_child_rcu(n, index);
925
926 if (!n)
927 break;
928
929 index = get_cindex(key, n);
930
931 /* This bit of code is a bit tricky but it combines multiple
932 * checks into a single check. The prefix consists of the
933 * prefix plus zeros for the bits in the cindex. The index
934 * is the difference between the key and this value. From
935 * this we can actually derive several pieces of data.
936 * if (index >= (1ul << bits))
937 * we have a mismatch in skip bits and failed
938 * else
939 * we know the value is cindex
940 *
941 * This check is safe even if bits == KEYLENGTH due to the
942 * fact that we can only allocate a node with 32 bits if a
943 * long is greater than 32 bits.
944 */
945 if (index >= (1ul << n->bits)) {
946 n = NULL;
947 break;
948 }
949
950 /* keep searching until we find a perfect match leaf or NULL */
951 } while (IS_TNODE(n));
952
953 *tp = pn;
954
955 return n;
956}
957
958/* Return the first fib alias matching TOS with
959 * priority less than or equal to PRIO.
960 */
961static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen,
962 u8 tos, u32 prio, u32 tb_id)
963{
964 struct fib_alias *fa;
965
966 if (!fah)
967 return NULL;
968
969 hlist_for_each_entry(fa, fah, fa_list) {
970 if (fa->fa_slen < slen)
971 continue;
972 if (fa->fa_slen != slen)
973 break;
974 if (fa->tb_id > tb_id)
975 continue;
976 if (fa->tb_id != tb_id)
977 break;
978 if (fa->fa_tos > tos)
979 continue;
980 if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos)
981 return fa;
982 }
983
984 return NULL;
985}
986
987static void trie_rebalance(struct trie *t, struct key_vector *tn)
988{
989 while (!IS_TRIE(tn))
990 tn = resize(t, tn);
991}
992
993static int fib_insert_node(struct trie *t, struct key_vector *tp,
994 struct fib_alias *new, t_key key)
995{
996 struct key_vector *n, *l;
997
998 l = leaf_new(key, new);
999 if (!l)
1000 goto noleaf;
1001
1002 /* retrieve child from parent node */
1003 n = get_child(tp, get_index(key, tp));
1004
1005 /* Case 2: n is a LEAF or a TNODE and the key doesn't match.
1006 *
1007 * Add a new tnode here
1008 * first tnode need some special handling
1009 * leaves us in position for handling as case 3
1010 */
1011 if (n) {
1012 struct key_vector *tn;
1013
1014 tn = tnode_new(key, __fls(key ^ n->key), 1);
1015 if (!tn)
1016 goto notnode;
1017
1018 /* initialize routes out of node */
1019 NODE_INIT_PARENT(tn, tp);
1020 put_child(tn, get_index(key, tn) ^ 1, n);
1021
1022 /* start adding routes into the node */
1023 put_child_root(tp, key, tn);
1024 node_set_parent(n, tn);
1025
1026 /* parent now has a NULL spot where the leaf can go */
1027 tp = tn;
1028 }
1029
1030 /* Case 3: n is NULL, and will just insert a new leaf */
1031 NODE_INIT_PARENT(l, tp);
1032 put_child_root(tp, key, l);
1033 trie_rebalance(t, tp);
1034
1035 return 0;
1036notnode:
1037 node_free(l);
1038noleaf:
1039 return -ENOMEM;
1040}
1041
1042static int fib_insert_alias(struct trie *t, struct key_vector *tp,
1043 struct key_vector *l, struct fib_alias *new,
1044 struct fib_alias *fa, t_key key)
1045{
1046 if (!l)
1047 return fib_insert_node(t, tp, new, key);
1048
1049 if (fa) {
1050 hlist_add_before_rcu(&new->fa_list, &fa->fa_list);
1051 } else {
1052 struct fib_alias *last;
1053
1054 hlist_for_each_entry(last, &l->leaf, fa_list) {
1055 if (new->fa_slen < last->fa_slen)
1056 break;
1057 if ((new->fa_slen == last->fa_slen) &&
1058 (new->tb_id > last->tb_id))
1059 break;
1060 fa = last;
1061 }
1062
1063 if (fa)
1064 hlist_add_behind_rcu(&new->fa_list, &fa->fa_list);
1065 else
1066 hlist_add_head_rcu(&new->fa_list, &l->leaf);
1067 }
1068
1069 /* if we added to the tail node then we need to update slen */
1070 if (l->slen < new->fa_slen) {
1071 l->slen = new->fa_slen;
1072 leaf_push_suffix(tp, l);
1073 }
1074
1075 return 0;
1076}
1077
1078/* Caller must hold RTNL. */
1079int fib_table_insert(struct fib_table *tb, struct fib_config *cfg)
1080{
1081 struct trie *t = (struct trie *)tb->tb_data;
1082 struct fib_alias *fa, *new_fa;
1083 struct key_vector *l, *tp;
1084 unsigned int nlflags = 0;
1085 struct fib_info *fi;
1086 u8 plen = cfg->fc_dst_len;
1087 u8 slen = KEYLENGTH - plen;
1088 u8 tos = cfg->fc_tos;
1089 u32 key;
1090 int err;
1091
1092 if (plen > KEYLENGTH)
1093 return -EINVAL;
1094
1095 key = ntohl(cfg->fc_dst);
1096
1097 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
1098
1099 if ((plen < KEYLENGTH) && (key << plen))
1100 return -EINVAL;
1101
1102 fi = fib_create_info(cfg);
1103 if (IS_ERR(fi)) {
1104 err = PTR_ERR(fi);
1105 goto err;
1106 }
1107
1108 l = fib_find_node(t, &tp, key);
1109 fa = l ? fib_find_alias(&l->leaf, slen, tos, fi->fib_priority,
1110 tb->tb_id) : NULL;
1111
1112 /* Now fa, if non-NULL, points to the first fib alias
1113 * with the same keys [prefix,tos,priority], if such key already
1114 * exists or to the node before which we will insert new one.
1115 *
1116 * If fa is NULL, we will need to allocate a new one and
1117 * insert to the tail of the section matching the suffix length
1118 * of the new alias.
1119 */
1120
1121 if (fa && fa->fa_tos == tos &&
1122 fa->fa_info->fib_priority == fi->fib_priority) {
1123 struct fib_alias *fa_first, *fa_match;
1124
1125 err = -EEXIST;
1126 if (cfg->fc_nlflags & NLM_F_EXCL)
1127 goto out;
1128
1129 /* We have 2 goals:
1130 * 1. Find exact match for type, scope, fib_info to avoid
1131 * duplicate routes
1132 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
1133 */
1134 fa_match = NULL;
1135 fa_first = fa;
1136 hlist_for_each_entry_from(fa, fa_list) {
1137 if ((fa->fa_slen != slen) ||
1138 (fa->tb_id != tb->tb_id) ||
1139 (fa->fa_tos != tos))
1140 break;
1141 if (fa->fa_info->fib_priority != fi->fib_priority)
1142 break;
1143 if (fa->fa_type == cfg->fc_type &&
1144 fa->fa_info == fi) {
1145 fa_match = fa;
1146 break;
1147 }
1148 }
1149
1150 if (cfg->fc_nlflags & NLM_F_REPLACE) {
1151 struct fib_info *fi_drop;
1152 u8 state;
1153
1154 fa = fa_first;
1155 if (fa_match) {
1156 if (fa == fa_match)
1157 err = 0;
1158 goto out;
1159 }
1160 err = -ENOBUFS;
1161 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1162 if (!new_fa)
1163 goto out;
1164
1165 fi_drop = fa->fa_info;
1166 new_fa->fa_tos = fa->fa_tos;
1167 new_fa->fa_info = fi;
1168 new_fa->fa_type = cfg->fc_type;
1169 state = fa->fa_state;
1170 new_fa->fa_state = state & ~FA_S_ACCESSED;
1171 new_fa->fa_slen = fa->fa_slen;
1172 new_fa->tb_id = tb->tb_id;
1173 new_fa->fa_default = -1;
1174
1175 err = switchdev_fib_ipv4_add(key, plen, fi,
1176 new_fa->fa_tos,
1177 cfg->fc_type,
1178 cfg->fc_nlflags,
1179 tb->tb_id);
1180 if (err) {
1181 switchdev_fib_ipv4_abort(fi);
1182 kmem_cache_free(fn_alias_kmem, new_fa);
1183 goto out;
1184 }
1185
1186 hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list);
1187
1188 alias_free_mem_rcu(fa);
1189
1190 fib_release_info(fi_drop);
1191 if (state & FA_S_ACCESSED)
1192 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1193 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
1194 tb->tb_id, &cfg->fc_nlinfo, NLM_F_REPLACE);
1195
1196 goto succeeded;
1197 }
1198 /* Error if we find a perfect match which
1199 * uses the same scope, type, and nexthop
1200 * information.
1201 */
1202 if (fa_match)
1203 goto out;
1204
1205 if (cfg->fc_nlflags & NLM_F_APPEND)
1206 nlflags = NLM_F_APPEND;
1207 else
1208 fa = fa_first;
1209 }
1210 err = -ENOENT;
1211 if (!(cfg->fc_nlflags & NLM_F_CREATE))
1212 goto out;
1213
1214 err = -ENOBUFS;
1215 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1216 if (!new_fa)
1217 goto out;
1218
1219 new_fa->fa_info = fi;
1220 new_fa->fa_tos = tos;
1221 new_fa->fa_type = cfg->fc_type;
1222 new_fa->fa_state = 0;
1223 new_fa->fa_slen = slen;
1224 new_fa->tb_id = tb->tb_id;
1225 new_fa->fa_default = -1;
1226
1227 /* (Optionally) offload fib entry to switch hardware. */
1228 err = switchdev_fib_ipv4_add(key, plen, fi, tos, cfg->fc_type,
1229 cfg->fc_nlflags, tb->tb_id);
1230 if (err) {
1231 switchdev_fib_ipv4_abort(fi);
1232 goto out_free_new_fa;
1233 }
1234
1235 /* Insert new entry to the list. */
1236 err = fib_insert_alias(t, tp, l, new_fa, fa, key);
1237 if (err)
1238 goto out_sw_fib_del;
1239
1240 if (!plen)
1241 tb->tb_num_default++;
1242
1243 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1244 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id,
1245 &cfg->fc_nlinfo, nlflags);
1246succeeded:
1247 return 0;
1248
1249out_sw_fib_del:
1250 switchdev_fib_ipv4_del(key, plen, fi, tos, cfg->fc_type, tb->tb_id);
1251out_free_new_fa:
1252 kmem_cache_free(fn_alias_kmem, new_fa);
1253out:
1254 fib_release_info(fi);
1255err:
1256 return err;
1257}
1258
1259static inline t_key prefix_mismatch(t_key key, struct key_vector *n)
1260{
1261 t_key prefix = n->key;
1262
1263 return (key ^ prefix) & (prefix | -prefix);
1264}
1265
1266/* should be called with rcu_read_lock */
1267int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
1268 struct fib_result *res, int fib_flags)
1269{
1270 struct trie *t = (struct trie *) tb->tb_data;
1271#ifdef CONFIG_IP_FIB_TRIE_STATS
1272 struct trie_use_stats __percpu *stats = t->stats;
1273#endif
1274 const t_key key = ntohl(flp->daddr);
1275 struct key_vector *n, *pn;
1276 struct fib_alias *fa;
1277 unsigned long index;
1278 t_key cindex;
1279
1280 trace_fib_table_lookup(tb->tb_id, flp);
1281
1282 pn = t->kv;
1283 cindex = 0;
1284
1285 n = get_child_rcu(pn, cindex);
1286 if (!n)
1287 return -EAGAIN;
1288
1289#ifdef CONFIG_IP_FIB_TRIE_STATS
1290 this_cpu_inc(stats->gets);
1291#endif
1292
1293 /* Step 1: Travel to the longest prefix match in the trie */
1294 for (;;) {
1295 index = get_cindex(key, n);
1296
1297 /* This bit of code is a bit tricky but it combines multiple
1298 * checks into a single check. The prefix consists of the
1299 * prefix plus zeros for the "bits" in the prefix. The index
1300 * is the difference between the key and this value. From
1301 * this we can actually derive several pieces of data.
1302 * if (index >= (1ul << bits))
1303 * we have a mismatch in skip bits and failed
1304 * else
1305 * we know the value is cindex
1306 *
1307 * This check is safe even if bits == KEYLENGTH due to the
1308 * fact that we can only allocate a node with 32 bits if a
1309 * long is greater than 32 bits.
1310 */
1311 if (index >= (1ul << n->bits))
1312 break;
1313
1314 /* we have found a leaf. Prefixes have already been compared */
1315 if (IS_LEAF(n))
1316 goto found;
1317
1318 /* only record pn and cindex if we are going to be chopping
1319 * bits later. Otherwise we are just wasting cycles.
1320 */
1321 if (n->slen > n->pos) {
1322 pn = n;
1323 cindex = index;
1324 }
1325
1326 n = get_child_rcu(n, index);
1327 if (unlikely(!n))
1328 goto backtrace;
1329 }
1330
1331 /* Step 2: Sort out leaves and begin backtracing for longest prefix */
1332 for (;;) {
1333 /* record the pointer where our next node pointer is stored */
1334 struct key_vector __rcu **cptr = n->tnode;
1335
1336 /* This test verifies that none of the bits that differ
1337 * between the key and the prefix exist in the region of
1338 * the lsb and higher in the prefix.
1339 */
1340 if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos))
1341 goto backtrace;
1342
1343 /* exit out and process leaf */
1344 if (unlikely(IS_LEAF(n)))
1345 break;
1346
1347 /* Don't bother recording parent info. Since we are in
1348 * prefix match mode we will have to come back to wherever
1349 * we started this traversal anyway
1350 */
1351
1352 while ((n = rcu_dereference(*cptr)) == NULL) {
1353backtrace:
1354#ifdef CONFIG_IP_FIB_TRIE_STATS
1355 if (!n)
1356 this_cpu_inc(stats->null_node_hit);
1357#endif
1358 /* If we are at cindex 0 there are no more bits for
1359 * us to strip at this level so we must ascend back
1360 * up one level to see if there are any more bits to
1361 * be stripped there.
1362 */
1363 while (!cindex) {
1364 t_key pkey = pn->key;
1365
1366 /* If we don't have a parent then there is
1367 * nothing for us to do as we do not have any
1368 * further nodes to parse.
1369 */
1370 if (IS_TRIE(pn))
1371 return -EAGAIN;
1372#ifdef CONFIG_IP_FIB_TRIE_STATS
1373 this_cpu_inc(stats->backtrack);
1374#endif
1375 /* Get Child's index */
1376 pn = node_parent_rcu(pn);
1377 cindex = get_index(pkey, pn);
1378 }
1379
1380 /* strip the least significant bit from the cindex */
1381 cindex &= cindex - 1;
1382
1383 /* grab pointer for next child node */
1384 cptr = &pn->tnode[cindex];
1385 }
1386 }
1387
1388found:
1389 /* this line carries forward the xor from earlier in the function */
1390 index = key ^ n->key;
1391
1392 /* Step 3: Process the leaf, if that fails fall back to backtracing */
1393 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
1394 struct fib_info *fi = fa->fa_info;
1395 int nhsel, err;
1396
1397 if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) {
1398 if (index >= (1ul << fa->fa_slen))
1399 continue;
1400 }
1401 if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
1402 continue;
1403 if (fi->fib_dead)
1404 continue;
1405 if (fa->fa_info->fib_scope < flp->flowi4_scope)
1406 continue;
1407 fib_alias_accessed(fa);
1408 err = fib_props[fa->fa_type].error;
1409 if (unlikely(err < 0)) {
1410#ifdef CONFIG_IP_FIB_TRIE_STATS
1411 this_cpu_inc(stats->semantic_match_passed);
1412#endif
1413 return err;
1414 }
1415 if (fi->fib_flags & RTNH_F_DEAD)
1416 continue;
1417 for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) {
1418 const struct fib_nh *nh = &fi->fib_nh[nhsel];
1419 struct in_device *in_dev = __in_dev_get_rcu(nh->nh_dev);
1420
1421 if (nh->nh_flags & RTNH_F_DEAD)
1422 continue;
1423 if (in_dev &&
1424 IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) &&
1425 nh->nh_flags & RTNH_F_LINKDOWN &&
1426 !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE))
1427 continue;
1428 if (!(flp->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) {
1429 if (flp->flowi4_oif &&
1430 flp->flowi4_oif != nh->nh_oif)
1431 continue;
1432 }
1433
1434 if (!(fib_flags & FIB_LOOKUP_NOREF))
1435 atomic_inc(&fi->fib_clntref);
1436
1437 res->prefixlen = KEYLENGTH - fa->fa_slen;
1438 res->nh_sel = nhsel;
1439 res->type = fa->fa_type;
1440 res->scope = fi->fib_scope;
1441 res->fi = fi;
1442 res->table = tb;
1443 res->fa_head = &n->leaf;
1444#ifdef CONFIG_IP_FIB_TRIE_STATS
1445 this_cpu_inc(stats->semantic_match_passed);
1446#endif
1447 trace_fib_table_lookup_nh(nh);
1448
1449 return err;
1450 }
1451 }
1452#ifdef CONFIG_IP_FIB_TRIE_STATS
1453 this_cpu_inc(stats->semantic_match_miss);
1454#endif
1455 goto backtrace;
1456}
1457EXPORT_SYMBOL_GPL(fib_table_lookup);
1458
1459static void fib_remove_alias(struct trie *t, struct key_vector *tp,
1460 struct key_vector *l, struct fib_alias *old)
1461{
1462 /* record the location of the previous list_info entry */
1463 struct hlist_node **pprev = old->fa_list.pprev;
1464 struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next);
1465
1466 /* remove the fib_alias from the list */
1467 hlist_del_rcu(&old->fa_list);
1468
1469 /* if we emptied the list this leaf will be freed and we can sort
1470 * out parent suffix lengths as a part of trie_rebalance
1471 */
1472 if (hlist_empty(&l->leaf)) {
1473 put_child_root(tp, l->key, NULL);
1474 node_free(l);
1475 trie_rebalance(t, tp);
1476 return;
1477 }
1478
1479 /* only access fa if it is pointing at the last valid hlist_node */
1480 if (*pprev)
1481 return;
1482
1483 /* update the trie with the latest suffix length */
1484 l->slen = fa->fa_slen;
1485 leaf_pull_suffix(tp, l);
1486}
1487
1488/* Caller must hold RTNL. */
1489int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
1490{
1491 struct trie *t = (struct trie *) tb->tb_data;
1492 struct fib_alias *fa, *fa_to_delete;
1493 struct key_vector *l, *tp;
1494 u8 plen = cfg->fc_dst_len;
1495 u8 slen = KEYLENGTH - plen;
1496 u8 tos = cfg->fc_tos;
1497 u32 key;
1498
1499 if (plen > KEYLENGTH)
1500 return -EINVAL;
1501
1502 key = ntohl(cfg->fc_dst);
1503
1504 if ((plen < KEYLENGTH) && (key << plen))
1505 return -EINVAL;
1506
1507 l = fib_find_node(t, &tp, key);
1508 if (!l)
1509 return -ESRCH;
1510
1511 fa = fib_find_alias(&l->leaf, slen, tos, 0, tb->tb_id);
1512 if (!fa)
1513 return -ESRCH;
1514
1515 pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
1516
1517 fa_to_delete = NULL;
1518 hlist_for_each_entry_from(fa, fa_list) {
1519 struct fib_info *fi = fa->fa_info;
1520
1521 if ((fa->fa_slen != slen) ||
1522 (fa->tb_id != tb->tb_id) ||
1523 (fa->fa_tos != tos))
1524 break;
1525
1526 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
1527 (cfg->fc_scope == RT_SCOPE_NOWHERE ||
1528 fa->fa_info->fib_scope == cfg->fc_scope) &&
1529 (!cfg->fc_prefsrc ||
1530 fi->fib_prefsrc == cfg->fc_prefsrc) &&
1531 (!cfg->fc_protocol ||
1532 fi->fib_protocol == cfg->fc_protocol) &&
1533 fib_nh_match(cfg, fi) == 0) {
1534 fa_to_delete = fa;
1535 break;
1536 }
1537 }
1538
1539 if (!fa_to_delete)
1540 return -ESRCH;
1541
1542 switchdev_fib_ipv4_del(key, plen, fa_to_delete->fa_info, tos,
1543 cfg->fc_type, tb->tb_id);
1544
1545 rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id,
1546 &cfg->fc_nlinfo, 0);
1547
1548 if (!plen)
1549 tb->tb_num_default--;
1550
1551 fib_remove_alias(t, tp, l, fa_to_delete);
1552
1553 if (fa_to_delete->fa_state & FA_S_ACCESSED)
1554 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1555
1556 fib_release_info(fa_to_delete->fa_info);
1557 alias_free_mem_rcu(fa_to_delete);
1558 return 0;
1559}
1560
1561/* Scan for the next leaf starting at the provided key value */
1562static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key)
1563{
1564 struct key_vector *pn, *n = *tn;
1565 unsigned long cindex;
1566
1567 /* this loop is meant to try and find the key in the trie */
1568 do {
1569 /* record parent and next child index */
1570 pn = n;
1571 cindex = (key > pn->key) ? get_index(key, pn) : 0;
1572
1573 if (cindex >> pn->bits)
1574 break;
1575
1576 /* descend into the next child */
1577 n = get_child_rcu(pn, cindex++);
1578 if (!n)
1579 break;
1580
1581 /* guarantee forward progress on the keys */
1582 if (IS_LEAF(n) && (n->key >= key))
1583 goto found;
1584 } while (IS_TNODE(n));
1585
1586 /* this loop will search for the next leaf with a greater key */
1587 while (!IS_TRIE(pn)) {
1588 /* if we exhausted the parent node we will need to climb */
1589 if (cindex >= (1ul << pn->bits)) {
1590 t_key pkey = pn->key;
1591
1592 pn = node_parent_rcu(pn);
1593 cindex = get_index(pkey, pn) + 1;
1594 continue;
1595 }
1596
1597 /* grab the next available node */
1598 n = get_child_rcu(pn, cindex++);
1599 if (!n)
1600 continue;
1601
1602 /* no need to compare keys since we bumped the index */
1603 if (IS_LEAF(n))
1604 goto found;
1605
1606 /* Rescan start scanning in new node */
1607 pn = n;
1608 cindex = 0;
1609 }
1610
1611 *tn = pn;
1612 return NULL; /* Root of trie */
1613found:
1614 /* if we are at the limit for keys just return NULL for the tnode */
1615 *tn = pn;
1616 return n;
1617}
1618
1619static void fib_trie_free(struct fib_table *tb)
1620{
1621 struct trie *t = (struct trie *)tb->tb_data;
1622 struct key_vector *pn = t->kv;
1623 unsigned long cindex = 1;
1624 struct hlist_node *tmp;
1625 struct fib_alias *fa;
1626
1627 /* walk trie in reverse order and free everything */
1628 for (;;) {
1629 struct key_vector *n;
1630
1631 if (!(cindex--)) {
1632 t_key pkey = pn->key;
1633
1634 if (IS_TRIE(pn))
1635 break;
1636
1637 n = pn;
1638 pn = node_parent(pn);
1639
1640 /* drop emptied tnode */
1641 put_child_root(pn, n->key, NULL);
1642 node_free(n);
1643
1644 cindex = get_index(pkey, pn);
1645
1646 continue;
1647 }
1648
1649 /* grab the next available node */
1650 n = get_child(pn, cindex);
1651 if (!n)
1652 continue;
1653
1654 if (IS_TNODE(n)) {
1655 /* record pn and cindex for leaf walking */
1656 pn = n;
1657 cindex = 1ul << n->bits;
1658
1659 continue;
1660 }
1661
1662 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1663 hlist_del_rcu(&fa->fa_list);
1664 alias_free_mem_rcu(fa);
1665 }
1666
1667 put_child_root(pn, n->key, NULL);
1668 node_free(n);
1669 }
1670
1671#ifdef CONFIG_IP_FIB_TRIE_STATS
1672 free_percpu(t->stats);
1673#endif
1674 kfree(tb);
1675}
1676
1677struct fib_table *fib_trie_unmerge(struct fib_table *oldtb)
1678{
1679 struct trie *ot = (struct trie *)oldtb->tb_data;
1680 struct key_vector *l, *tp = ot->kv;
1681 struct fib_table *local_tb;
1682 struct fib_alias *fa;
1683 struct trie *lt;
1684 t_key key = 0;
1685
1686 if (oldtb->tb_data == oldtb->__data)
1687 return oldtb;
1688
1689 local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL);
1690 if (!local_tb)
1691 return NULL;
1692
1693 lt = (struct trie *)local_tb->tb_data;
1694
1695 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
1696 struct key_vector *local_l = NULL, *local_tp;
1697
1698 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
1699 struct fib_alias *new_fa;
1700
1701 if (local_tb->tb_id != fa->tb_id)
1702 continue;
1703
1704 /* clone fa for new local table */
1705 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1706 if (!new_fa)
1707 goto out;
1708
1709 memcpy(new_fa, fa, sizeof(*fa));
1710
1711 /* insert clone into table */
1712 if (!local_l)
1713 local_l = fib_find_node(lt, &local_tp, l->key);
1714
1715 if (fib_insert_alias(lt, local_tp, local_l, new_fa,
1716 NULL, l->key))
1717 goto out;
1718 }
1719
1720 /* stop loop if key wrapped back to 0 */
1721 key = l->key + 1;
1722 if (key < l->key)
1723 break;
1724 }
1725
1726 return local_tb;
1727out:
1728 fib_trie_free(local_tb);
1729
1730 return NULL;
1731}
1732
1733/* Caller must hold RTNL */
1734void fib_table_flush_external(struct fib_table *tb)
1735{
1736 struct trie *t = (struct trie *)tb->tb_data;
1737 struct key_vector *pn = t->kv;
1738 unsigned long cindex = 1;
1739 struct hlist_node *tmp;
1740 struct fib_alias *fa;
1741
1742 /* walk trie in reverse order */
1743 for (;;) {
1744 unsigned char slen = 0;
1745 struct key_vector *n;
1746
1747 if (!(cindex--)) {
1748 t_key pkey = pn->key;
1749
1750 /* cannot resize the trie vector */
1751 if (IS_TRIE(pn))
1752 break;
1753
1754 /* resize completed node */
1755 pn = resize(t, pn);
1756 cindex = get_index(pkey, pn);
1757
1758 continue;
1759 }
1760
1761 /* grab the next available node */
1762 n = get_child(pn, cindex);
1763 if (!n)
1764 continue;
1765
1766 if (IS_TNODE(n)) {
1767 /* record pn and cindex for leaf walking */
1768 pn = n;
1769 cindex = 1ul << n->bits;
1770
1771 continue;
1772 }
1773
1774 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1775 struct fib_info *fi = fa->fa_info;
1776
1777 /* if alias was cloned to local then we just
1778 * need to remove the local copy from main
1779 */
1780 if (tb->tb_id != fa->tb_id) {
1781 hlist_del_rcu(&fa->fa_list);
1782 alias_free_mem_rcu(fa);
1783 continue;
1784 }
1785
1786 /* record local slen */
1787 slen = fa->fa_slen;
1788
1789 if (!fi || !(fi->fib_flags & RTNH_F_OFFLOAD))
1790 continue;
1791
1792 switchdev_fib_ipv4_del(n->key, KEYLENGTH - fa->fa_slen,
1793 fi, fa->fa_tos, fa->fa_type,
1794 tb->tb_id);
1795 }
1796
1797 /* update leaf slen */
1798 n->slen = slen;
1799
1800 if (hlist_empty(&n->leaf)) {
1801 put_child_root(pn, n->key, NULL);
1802 node_free(n);
1803 }
1804 }
1805}
1806
1807/* Caller must hold RTNL. */
1808int fib_table_flush(struct fib_table *tb)
1809{
1810 struct trie *t = (struct trie *)tb->tb_data;
1811 struct key_vector *pn = t->kv;
1812 unsigned long cindex = 1;
1813 struct hlist_node *tmp;
1814 struct fib_alias *fa;
1815 int found = 0;
1816
1817 /* walk trie in reverse order */
1818 for (;;) {
1819 unsigned char slen = 0;
1820 struct key_vector *n;
1821
1822 if (!(cindex--)) {
1823 t_key pkey = pn->key;
1824
1825 /* cannot resize the trie vector */
1826 if (IS_TRIE(pn))
1827 break;
1828
1829 /* resize completed node */
1830 pn = resize(t, pn);
1831 cindex = get_index(pkey, pn);
1832
1833 continue;
1834 }
1835
1836 /* grab the next available node */
1837 n = get_child(pn, cindex);
1838 if (!n)
1839 continue;
1840
1841 if (IS_TNODE(n)) {
1842 /* record pn and cindex for leaf walking */
1843 pn = n;
1844 cindex = 1ul << n->bits;
1845
1846 continue;
1847 }
1848
1849 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1850 struct fib_info *fi = fa->fa_info;
1851
1852 if (!fi || !(fi->fib_flags & RTNH_F_DEAD)) {
1853 slen = fa->fa_slen;
1854 continue;
1855 }
1856
1857 switchdev_fib_ipv4_del(n->key, KEYLENGTH - fa->fa_slen,
1858 fi, fa->fa_tos, fa->fa_type,
1859 tb->tb_id);
1860 hlist_del_rcu(&fa->fa_list);
1861 fib_release_info(fa->fa_info);
1862 alias_free_mem_rcu(fa);
1863 found++;
1864 }
1865
1866 /* update leaf slen */
1867 n->slen = slen;
1868
1869 if (hlist_empty(&n->leaf)) {
1870 put_child_root(pn, n->key, NULL);
1871 node_free(n);
1872 }
1873 }
1874
1875 pr_debug("trie_flush found=%d\n", found);
1876 return found;
1877}
1878
1879static void __trie_free_rcu(struct rcu_head *head)
1880{
1881 struct fib_table *tb = container_of(head, struct fib_table, rcu);
1882#ifdef CONFIG_IP_FIB_TRIE_STATS
1883 struct trie *t = (struct trie *)tb->tb_data;
1884
1885 if (tb->tb_data == tb->__data)
1886 free_percpu(t->stats);
1887#endif /* CONFIG_IP_FIB_TRIE_STATS */
1888 kfree(tb);
1889}
1890
1891void fib_free_table(struct fib_table *tb)
1892{
1893 call_rcu(&tb->rcu, __trie_free_rcu);
1894}
1895
1896static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb,
1897 struct sk_buff *skb, struct netlink_callback *cb)
1898{
1899 __be32 xkey = htonl(l->key);
1900 struct fib_alias *fa;
1901 int i, s_i;
1902
1903 s_i = cb->args[4];
1904 i = 0;
1905
1906 /* rcu_read_lock is hold by caller */
1907 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
1908 if (i < s_i) {
1909 i++;
1910 continue;
1911 }
1912
1913 if (tb->tb_id != fa->tb_id) {
1914 i++;
1915 continue;
1916 }
1917
1918 if (fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
1919 cb->nlh->nlmsg_seq,
1920 RTM_NEWROUTE,
1921 tb->tb_id,
1922 fa->fa_type,
1923 xkey,
1924 KEYLENGTH - fa->fa_slen,
1925 fa->fa_tos,
1926 fa->fa_info, NLM_F_MULTI) < 0) {
1927 cb->args[4] = i;
1928 return -1;
1929 }
1930 i++;
1931 }
1932
1933 cb->args[4] = i;
1934 return skb->len;
1935}
1936
1937/* rcu_read_lock needs to be hold by caller from readside */
1938int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
1939 struct netlink_callback *cb)
1940{
1941 struct trie *t = (struct trie *)tb->tb_data;
1942 struct key_vector *l, *tp = t->kv;
1943 /* Dump starting at last key.
1944 * Note: 0.0.0.0/0 (ie default) is first key.
1945 */
1946 int count = cb->args[2];
1947 t_key key = cb->args[3];
1948
1949 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
1950 if (fn_trie_dump_leaf(l, tb, skb, cb) < 0) {
1951 cb->args[3] = key;
1952 cb->args[2] = count;
1953 return -1;
1954 }
1955
1956 ++count;
1957 key = l->key + 1;
1958
1959 memset(&cb->args[4], 0,
1960 sizeof(cb->args) - 4*sizeof(cb->args[0]));
1961
1962 /* stop loop if key wrapped back to 0 */
1963 if (key < l->key)
1964 break;
1965 }
1966
1967 cb->args[3] = key;
1968 cb->args[2] = count;
1969
1970 return skb->len;
1971}
1972
1973void __init fib_trie_init(void)
1974{
1975 fn_alias_kmem = kmem_cache_create("ip_fib_alias",
1976 sizeof(struct fib_alias),
1977 0, SLAB_PANIC, NULL);
1978
1979 trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
1980 LEAF_SIZE,
1981 0, SLAB_PANIC, NULL);
1982}
1983
1984struct fib_table *fib_trie_table(u32 id, struct fib_table *alias)
1985{
1986 struct fib_table *tb;
1987 struct trie *t;
1988 size_t sz = sizeof(*tb);
1989
1990 if (!alias)
1991 sz += sizeof(struct trie);
1992
1993 tb = kzalloc(sz, GFP_KERNEL);
1994 if (!tb)
1995 return NULL;
1996
1997 tb->tb_id = id;
1998 tb->tb_num_default = 0;
1999 tb->tb_data = (alias ? alias->__data : tb->__data);
2000
2001 if (alias)
2002 return tb;
2003
2004 t = (struct trie *) tb->tb_data;
2005 t->kv[0].pos = KEYLENGTH;
2006 t->kv[0].slen = KEYLENGTH;
2007#ifdef CONFIG_IP_FIB_TRIE_STATS
2008 t->stats = alloc_percpu(struct trie_use_stats);
2009 if (!t->stats) {
2010 kfree(tb);
2011 tb = NULL;
2012 }
2013#endif
2014
2015 return tb;
2016}
2017
2018#ifdef CONFIG_PROC_FS
2019/* Depth first Trie walk iterator */
2020struct fib_trie_iter {
2021 struct seq_net_private p;
2022 struct fib_table *tb;
2023 struct key_vector *tnode;
2024 unsigned int index;
2025 unsigned int depth;
2026};
2027
2028static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter)
2029{
2030 unsigned long cindex = iter->index;
2031 struct key_vector *pn = iter->tnode;
2032 t_key pkey;
2033
2034 pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
2035 iter->tnode, iter->index, iter->depth);
2036
2037 while (!IS_TRIE(pn)) {
2038 while (cindex < child_length(pn)) {
2039 struct key_vector *n = get_child_rcu(pn, cindex++);
2040
2041 if (!n)
2042 continue;
2043
2044 if (IS_LEAF(n)) {
2045 iter->tnode = pn;
2046 iter->index = cindex;
2047 } else {
2048 /* push down one level */
2049 iter->tnode = n;
2050 iter->index = 0;
2051 ++iter->depth;
2052 }
2053
2054 return n;
2055 }
2056
2057 /* Current node exhausted, pop back up */
2058 pkey = pn->key;
2059 pn = node_parent_rcu(pn);
2060 cindex = get_index(pkey, pn) + 1;
2061 --iter->depth;
2062 }
2063
2064 /* record root node so further searches know we are done */
2065 iter->tnode = pn;
2066 iter->index = 0;
2067
2068 return NULL;
2069}
2070
2071static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter,
2072 struct trie *t)
2073{
2074 struct key_vector *n, *pn;
2075
2076 if (!t)
2077 return NULL;
2078
2079 pn = t->kv;
2080 n = rcu_dereference(pn->tnode[0]);
2081 if (!n)
2082 return NULL;
2083
2084 if (IS_TNODE(n)) {
2085 iter->tnode = n;
2086 iter->index = 0;
2087 iter->depth = 1;
2088 } else {
2089 iter->tnode = pn;
2090 iter->index = 0;
2091 iter->depth = 0;
2092 }
2093
2094 return n;
2095}
2096
2097static void trie_collect_stats(struct trie *t, struct trie_stat *s)
2098{
2099 struct key_vector *n;
2100 struct fib_trie_iter iter;
2101
2102 memset(s, 0, sizeof(*s));
2103
2104 rcu_read_lock();
2105 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) {
2106 if (IS_LEAF(n)) {
2107 struct fib_alias *fa;
2108
2109 s->leaves++;
2110 s->totdepth += iter.depth;
2111 if (iter.depth > s->maxdepth)
2112 s->maxdepth = iter.depth;
2113
2114 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list)
2115 ++s->prefixes;
2116 } else {
2117 s->tnodes++;
2118 if (n->bits < MAX_STAT_DEPTH)
2119 s->nodesizes[n->bits]++;
2120 s->nullpointers += tn_info(n)->empty_children;
2121 }
2122 }
2123 rcu_read_unlock();
2124}
2125
2126/*
2127 * This outputs /proc/net/fib_triestats
2128 */
2129static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
2130{
2131 unsigned int i, max, pointers, bytes, avdepth;
2132
2133 if (stat->leaves)
2134 avdepth = stat->totdepth*100 / stat->leaves;
2135 else
2136 avdepth = 0;
2137
2138 seq_printf(seq, "\tAver depth: %u.%02d\n",
2139 avdepth / 100, avdepth % 100);
2140 seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth);
2141
2142 seq_printf(seq, "\tLeaves: %u\n", stat->leaves);
2143 bytes = LEAF_SIZE * stat->leaves;
2144
2145 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes);
2146 bytes += sizeof(struct fib_alias) * stat->prefixes;
2147
2148 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);
2149 bytes += TNODE_SIZE(0) * stat->tnodes;
2150
2151 max = MAX_STAT_DEPTH;
2152 while (max > 0 && stat->nodesizes[max-1] == 0)
2153 max--;
2154
2155 pointers = 0;
2156 for (i = 1; i < max; i++)
2157 if (stat->nodesizes[i] != 0) {
2158 seq_printf(seq, " %u: %u", i, stat->nodesizes[i]);
2159 pointers += (1<<i) * stat->nodesizes[i];
2160 }
2161 seq_putc(seq, '\n');
2162 seq_printf(seq, "\tPointers: %u\n", pointers);
2163
2164 bytes += sizeof(struct key_vector *) * pointers;
2165 seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers);
2166 seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024);
2167}
2168
2169#ifdef CONFIG_IP_FIB_TRIE_STATS
2170static void trie_show_usage(struct seq_file *seq,
2171 const struct trie_use_stats __percpu *stats)
2172{
2173 struct trie_use_stats s = { 0 };
2174 int cpu;
2175
2176 /* loop through all of the CPUs and gather up the stats */
2177 for_each_possible_cpu(cpu) {
2178 const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu);
2179
2180 s.gets += pcpu->gets;
2181 s.backtrack += pcpu->backtrack;
2182 s.semantic_match_passed += pcpu->semantic_match_passed;
2183 s.semantic_match_miss += pcpu->semantic_match_miss;
2184 s.null_node_hit += pcpu->null_node_hit;
2185 s.resize_node_skipped += pcpu->resize_node_skipped;
2186 }
2187
2188 seq_printf(seq, "\nCounters:\n---------\n");
2189 seq_printf(seq, "gets = %u\n", s.gets);
2190 seq_printf(seq, "backtracks = %u\n", s.backtrack);
2191 seq_printf(seq, "semantic match passed = %u\n",
2192 s.semantic_match_passed);
2193 seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss);
2194 seq_printf(seq, "null node hit= %u\n", s.null_node_hit);
2195 seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped);
2196}
2197#endif /* CONFIG_IP_FIB_TRIE_STATS */
2198
2199static void fib_table_print(struct seq_file *seq, struct fib_table *tb)
2200{
2201 if (tb->tb_id == RT_TABLE_LOCAL)
2202 seq_puts(seq, "Local:\n");
2203 else if (tb->tb_id == RT_TABLE_MAIN)
2204 seq_puts(seq, "Main:\n");
2205 else
2206 seq_printf(seq, "Id %d:\n", tb->tb_id);
2207}
2208
2209
2210static int fib_triestat_seq_show(struct seq_file *seq, void *v)
2211{
2212 struct net *net = (struct net *)seq->private;
2213 unsigned int h;
2214
2215 seq_printf(seq,
2216 "Basic info: size of leaf:"
2217 " %Zd bytes, size of tnode: %Zd bytes.\n",
2218 LEAF_SIZE, TNODE_SIZE(0));
2219
2220 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2221 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2222 struct fib_table *tb;
2223
2224 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2225 struct trie *t = (struct trie *) tb->tb_data;
2226 struct trie_stat stat;
2227
2228 if (!t)
2229 continue;
2230
2231 fib_table_print(seq, tb);
2232
2233 trie_collect_stats(t, &stat);
2234 trie_show_stats(seq, &stat);
2235#ifdef CONFIG_IP_FIB_TRIE_STATS
2236 trie_show_usage(seq, t->stats);
2237#endif
2238 }
2239 }
2240
2241 return 0;
2242}
2243
2244static int fib_triestat_seq_open(struct inode *inode, struct file *file)
2245{
2246 return single_open_net(inode, file, fib_triestat_seq_show);
2247}
2248
2249static const struct file_operations fib_triestat_fops = {
2250 .owner = THIS_MODULE,
2251 .open = fib_triestat_seq_open,
2252 .read = seq_read,
2253 .llseek = seq_lseek,
2254 .release = single_release_net,
2255};
2256
2257static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos)
2258{
2259 struct fib_trie_iter *iter = seq->private;
2260 struct net *net = seq_file_net(seq);
2261 loff_t idx = 0;
2262 unsigned int h;
2263
2264 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2265 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2266 struct fib_table *tb;
2267
2268 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2269 struct key_vector *n;
2270
2271 for (n = fib_trie_get_first(iter,
2272 (struct trie *) tb->tb_data);
2273 n; n = fib_trie_get_next(iter))
2274 if (pos == idx++) {
2275 iter->tb = tb;
2276 return n;
2277 }
2278 }
2279 }
2280
2281 return NULL;
2282}
2283
2284static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
2285 __acquires(RCU)
2286{
2287 rcu_read_lock();
2288 return fib_trie_get_idx(seq, *pos);
2289}
2290
2291static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2292{
2293 struct fib_trie_iter *iter = seq->private;
2294 struct net *net = seq_file_net(seq);
2295 struct fib_table *tb = iter->tb;
2296 struct hlist_node *tb_node;
2297 unsigned int h;
2298 struct key_vector *n;
2299
2300 ++*pos;
2301 /* next node in same table */
2302 n = fib_trie_get_next(iter);
2303 if (n)
2304 return n;
2305
2306 /* walk rest of this hash chain */
2307 h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);
2308 while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) {
2309 tb = hlist_entry(tb_node, struct fib_table, tb_hlist);
2310 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2311 if (n)
2312 goto found;
2313 }
2314
2315 /* new hash chain */
2316 while (++h < FIB_TABLE_HASHSZ) {
2317 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2318 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2319 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2320 if (n)
2321 goto found;
2322 }
2323 }
2324 return NULL;
2325
2326found:
2327 iter->tb = tb;
2328 return n;
2329}
2330
2331static void fib_trie_seq_stop(struct seq_file *seq, void *v)
2332 __releases(RCU)
2333{
2334 rcu_read_unlock();
2335}
2336
2337static void seq_indent(struct seq_file *seq, int n)
2338{
2339 while (n-- > 0)
2340 seq_puts(seq, " ");
2341}
2342
2343static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
2344{
2345 switch (s) {
2346 case RT_SCOPE_UNIVERSE: return "universe";
2347 case RT_SCOPE_SITE: return "site";
2348 case RT_SCOPE_LINK: return "link";
2349 case RT_SCOPE_HOST: return "host";
2350 case RT_SCOPE_NOWHERE: return "nowhere";
2351 default:
2352 snprintf(buf, len, "scope=%d", s);
2353 return buf;
2354 }
2355}
2356
2357static const char *const rtn_type_names[__RTN_MAX] = {
2358 [RTN_UNSPEC] = "UNSPEC",
2359 [RTN_UNICAST] = "UNICAST",
2360 [RTN_LOCAL] = "LOCAL",
2361 [RTN_BROADCAST] = "BROADCAST",
2362 [RTN_ANYCAST] = "ANYCAST",
2363 [RTN_MULTICAST] = "MULTICAST",
2364 [RTN_BLACKHOLE] = "BLACKHOLE",
2365 [RTN_UNREACHABLE] = "UNREACHABLE",
2366 [RTN_PROHIBIT] = "PROHIBIT",
2367 [RTN_THROW] = "THROW",
2368 [RTN_NAT] = "NAT",
2369 [RTN_XRESOLVE] = "XRESOLVE",
2370};
2371
2372static inline const char *rtn_type(char *buf, size_t len, unsigned int t)
2373{
2374 if (t < __RTN_MAX && rtn_type_names[t])
2375 return rtn_type_names[t];
2376 snprintf(buf, len, "type %u", t);
2377 return buf;
2378}
2379
2380/* Pretty print the trie */
2381static int fib_trie_seq_show(struct seq_file *seq, void *v)
2382{
2383 const struct fib_trie_iter *iter = seq->private;
2384 struct key_vector *n = v;
2385
2386 if (IS_TRIE(node_parent_rcu(n)))
2387 fib_table_print(seq, iter->tb);
2388
2389 if (IS_TNODE(n)) {
2390 __be32 prf = htonl(n->key);
2391
2392 seq_indent(seq, iter->depth-1);
2393 seq_printf(seq, " +-- %pI4/%zu %u %u %u\n",
2394 &prf, KEYLENGTH - n->pos - n->bits, n->bits,
2395 tn_info(n)->full_children,
2396 tn_info(n)->empty_children);
2397 } else {
2398 __be32 val = htonl(n->key);
2399 struct fib_alias *fa;
2400
2401 seq_indent(seq, iter->depth);
2402 seq_printf(seq, " |-- %pI4\n", &val);
2403
2404 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
2405 char buf1[32], buf2[32];
2406
2407 seq_indent(seq, iter->depth + 1);
2408 seq_printf(seq, " /%zu %s %s",
2409 KEYLENGTH - fa->fa_slen,
2410 rtn_scope(buf1, sizeof(buf1),
2411 fa->fa_info->fib_scope),
2412 rtn_type(buf2, sizeof(buf2),
2413 fa->fa_type));
2414 if (fa->fa_tos)
2415 seq_printf(seq, " tos=%d", fa->fa_tos);
2416 seq_putc(seq, '\n');
2417 }
2418 }
2419
2420 return 0;
2421}
2422
2423static const struct seq_operations fib_trie_seq_ops = {
2424 .start = fib_trie_seq_start,
2425 .next = fib_trie_seq_next,
2426 .stop = fib_trie_seq_stop,
2427 .show = fib_trie_seq_show,
2428};
2429
2430static int fib_trie_seq_open(struct inode *inode, struct file *file)
2431{
2432 return seq_open_net(inode, file, &fib_trie_seq_ops,
2433 sizeof(struct fib_trie_iter));
2434}
2435
2436static const struct file_operations fib_trie_fops = {
2437 .owner = THIS_MODULE,
2438 .open = fib_trie_seq_open,
2439 .read = seq_read,
2440 .llseek = seq_lseek,
2441 .release = seq_release_net,
2442};
2443
2444struct fib_route_iter {
2445 struct seq_net_private p;
2446 struct fib_table *main_tb;
2447 struct key_vector *tnode;
2448 loff_t pos;
2449 t_key key;
2450};
2451
2452static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter,
2453 loff_t pos)
2454{
2455 struct fib_table *tb = iter->main_tb;
2456 struct key_vector *l, **tp = &iter->tnode;
2457 struct trie *t;
2458 t_key key;
2459
2460 /* use cache location of next-to-find key */
2461 if (iter->pos > 0 && pos >= iter->pos) {
2462 pos -= iter->pos;
2463 key = iter->key;
2464 } else {
2465 t = (struct trie *)tb->tb_data;
2466 iter->tnode = t->kv;
2467 iter->pos = 0;
2468 key = 0;
2469 }
2470
2471 while ((l = leaf_walk_rcu(tp, key)) != NULL) {
2472 key = l->key + 1;
2473 iter->pos++;
2474
2475 if (--pos <= 0)
2476 break;
2477
2478 l = NULL;
2479
2480 /* handle unlikely case of a key wrap */
2481 if (!key)
2482 break;
2483 }
2484
2485 if (l)
2486 iter->key = key; /* remember it */
2487 else
2488 iter->pos = 0; /* forget it */
2489
2490 return l;
2491}
2492
2493static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos)
2494 __acquires(RCU)
2495{
2496 struct fib_route_iter *iter = seq->private;
2497 struct fib_table *tb;
2498 struct trie *t;
2499
2500 rcu_read_lock();
2501
2502 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
2503 if (!tb)
2504 return NULL;
2505
2506 iter->main_tb = tb;
2507
2508 if (*pos != 0)
2509 return fib_route_get_idx(iter, *pos);
2510
2511 t = (struct trie *)tb->tb_data;
2512 iter->tnode = t->kv;
2513 iter->pos = 0;
2514 iter->key = 0;
2515
2516 return SEQ_START_TOKEN;
2517}
2518
2519static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2520{
2521 struct fib_route_iter *iter = seq->private;
2522 struct key_vector *l = NULL;
2523 t_key key = iter->key;
2524
2525 ++*pos;
2526
2527 /* only allow key of 0 for start of sequence */
2528 if ((v == SEQ_START_TOKEN) || key)
2529 l = leaf_walk_rcu(&iter->tnode, key);
2530
2531 if (l) {
2532 iter->key = l->key + 1;
2533 iter->pos++;
2534 } else {
2535 iter->pos = 0;
2536 }
2537
2538 return l;
2539}
2540
2541static void fib_route_seq_stop(struct seq_file *seq, void *v)
2542 __releases(RCU)
2543{
2544 rcu_read_unlock();
2545}
2546
2547static unsigned int fib_flag_trans(int type, __be32 mask, const struct fib_info *fi)
2548{
2549 unsigned int flags = 0;
2550
2551 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT)
2552 flags = RTF_REJECT;
2553 if (fi && fi->fib_nh->nh_gw)
2554 flags |= RTF_GATEWAY;
2555 if (mask == htonl(0xFFFFFFFF))
2556 flags |= RTF_HOST;
2557 flags |= RTF_UP;
2558 return flags;
2559}
2560
2561/*
2562 * This outputs /proc/net/route.
2563 * The format of the file is not supposed to be changed
2564 * and needs to be same as fib_hash output to avoid breaking
2565 * legacy utilities
2566 */
2567static int fib_route_seq_show(struct seq_file *seq, void *v)
2568{
2569 struct fib_route_iter *iter = seq->private;
2570 struct fib_table *tb = iter->main_tb;
2571 struct fib_alias *fa;
2572 struct key_vector *l = v;
2573 __be32 prefix;
2574
2575 if (v == SEQ_START_TOKEN) {
2576 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
2577 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
2578 "\tWindow\tIRTT");
2579 return 0;
2580 }
2581
2582 prefix = htonl(l->key);
2583
2584 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2585 const struct fib_info *fi = fa->fa_info;
2586 __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen);
2587 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);
2588
2589 if ((fa->fa_type == RTN_BROADCAST) ||
2590 (fa->fa_type == RTN_MULTICAST))
2591 continue;
2592
2593 if (fa->tb_id != tb->tb_id)
2594 continue;
2595
2596 seq_setwidth(seq, 127);
2597
2598 if (fi)
2599 seq_printf(seq,
2600 "%s\t%08X\t%08X\t%04X\t%d\t%u\t"
2601 "%d\t%08X\t%d\t%u\t%u",
2602 fi->fib_dev ? fi->fib_dev->name : "*",
2603 prefix,
2604 fi->fib_nh->nh_gw, flags, 0, 0,
2605 fi->fib_priority,
2606 mask,
2607 (fi->fib_advmss ?
2608 fi->fib_advmss + 40 : 0),
2609 fi->fib_window,
2610 fi->fib_rtt >> 3);
2611 else
2612 seq_printf(seq,
2613 "*\t%08X\t%08X\t%04X\t%d\t%u\t"
2614 "%d\t%08X\t%d\t%u\t%u",
2615 prefix, 0, flags, 0, 0, 0,
2616 mask, 0, 0, 0);
2617
2618 seq_pad(seq, '\n');
2619 }
2620
2621 return 0;
2622}
2623
2624static const struct seq_operations fib_route_seq_ops = {
2625 .start = fib_route_seq_start,
2626 .next = fib_route_seq_next,
2627 .stop = fib_route_seq_stop,
2628 .show = fib_route_seq_show,
2629};
2630
2631static int fib_route_seq_open(struct inode *inode, struct file *file)
2632{
2633 return seq_open_net(inode, file, &fib_route_seq_ops,
2634 sizeof(struct fib_route_iter));
2635}
2636
2637static const struct file_operations fib_route_fops = {
2638 .owner = THIS_MODULE,
2639 .open = fib_route_seq_open,
2640 .read = seq_read,
2641 .llseek = seq_lseek,
2642 .release = seq_release_net,
2643};
2644
2645int __net_init fib_proc_init(struct net *net)
2646{
2647 if (!proc_create("fib_trie", S_IRUGO, net->proc_net, &fib_trie_fops))
2648 goto out1;
2649
2650 if (!proc_create("fib_triestat", S_IRUGO, net->proc_net,
2651 &fib_triestat_fops))
2652 goto out2;
2653
2654 if (!proc_create("route", S_IRUGO, net->proc_net, &fib_route_fops))
2655 goto out3;
2656
2657 return 0;
2658
2659out3:
2660 remove_proc_entry("fib_triestat", net->proc_net);
2661out2:
2662 remove_proc_entry("fib_trie", net->proc_net);
2663out1:
2664 return -ENOMEM;
2665}
2666
2667void __net_exit fib_proc_exit(struct net *net)
2668{
2669 remove_proc_entry("fib_trie", net->proc_net);
2670 remove_proc_entry("fib_triestat", net->proc_net);
2671 remove_proc_entry("route", net->proc_net);
2672}
2673
2674#endif /* CONFIG_PROC_FS */