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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *
4 * Robert Olsson <robert.olsson@its.uu.se> Uppsala Universitet
5 * & Swedish University of Agricultural Sciences.
6 *
7 * Jens Laas <jens.laas@data.slu.se> Swedish University of
8 * Agricultural Sciences.
9 *
10 * Hans Liss <hans.liss@its.uu.se> Uppsala Universitet
11 *
12 * This work is based on the LPC-trie which is originally described in:
13 *
14 * An experimental study of compression methods for dynamic tries
15 * Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002.
16 * http://www.csc.kth.se/~snilsson/software/dyntrie2/
17 *
18 * IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson
19 * IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999
20 *
21 * Code from fib_hash has been reused which includes the following header:
22 *
23 * INET An implementation of the TCP/IP protocol suite for the LINUX
24 * operating system. INET is implemented using the BSD Socket
25 * interface as the means of communication with the user level.
26 *
27 * IPv4 FIB: lookup engine and maintenance routines.
28 *
29 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
30 *
31 * Substantial contributions to this work comes from:
32 *
33 * David S. Miller, <davem@davemloft.net>
34 * Stephen Hemminger <shemminger@osdl.org>
35 * Paul E. McKenney <paulmck@us.ibm.com>
36 * Patrick McHardy <kaber@trash.net>
37 */
38
39#define VERSION "0.409"
40
41#include <linux/cache.h>
42#include <linux/uaccess.h>
43#include <linux/bitops.h>
44#include <linux/types.h>
45#include <linux/kernel.h>
46#include <linux/mm.h>
47#include <linux/string.h>
48#include <linux/socket.h>
49#include <linux/sockios.h>
50#include <linux/errno.h>
51#include <linux/in.h>
52#include <linux/inet.h>
53#include <linux/inetdevice.h>
54#include <linux/netdevice.h>
55#include <linux/if_arp.h>
56#include <linux/proc_fs.h>
57#include <linux/rcupdate.h>
58#include <linux/skbuff.h>
59#include <linux/netlink.h>
60#include <linux/init.h>
61#include <linux/list.h>
62#include <linux/slab.h>
63#include <linux/export.h>
64#include <linux/vmalloc.h>
65#include <linux/notifier.h>
66#include <net/net_namespace.h>
67#include <net/ip.h>
68#include <net/protocol.h>
69#include <net/route.h>
70#include <net/tcp.h>
71#include <net/sock.h>
72#include <net/ip_fib.h>
73#include <net/fib_notifier.h>
74#include <trace/events/fib.h>
75#include "fib_lookup.h"
76
77static int call_fib_entry_notifier(struct notifier_block *nb, struct net *net,
78 enum fib_event_type event_type, u32 dst,
79 int dst_len, struct fib_alias *fa)
80{
81 struct fib_entry_notifier_info info = {
82 .dst = dst,
83 .dst_len = dst_len,
84 .fi = fa->fa_info,
85 .tos = fa->fa_tos,
86 .type = fa->fa_type,
87 .tb_id = fa->tb_id,
88 };
89 return call_fib4_notifier(nb, net, event_type, &info.info);
90}
91
92static int call_fib_entry_notifiers(struct net *net,
93 enum fib_event_type event_type, u32 dst,
94 int dst_len, struct fib_alias *fa,
95 struct netlink_ext_ack *extack)
96{
97 struct fib_entry_notifier_info info = {
98 .info.extack = extack,
99 .dst = dst,
100 .dst_len = dst_len,
101 .fi = fa->fa_info,
102 .tos = fa->fa_tos,
103 .type = fa->fa_type,
104 .tb_id = fa->tb_id,
105 };
106 return call_fib4_notifiers(net, event_type, &info.info);
107}
108
109#define MAX_STAT_DEPTH 32
110
111#define KEYLENGTH (8*sizeof(t_key))
112#define KEY_MAX ((t_key)~0)
113
114typedef unsigned int t_key;
115
116#define IS_TRIE(n) ((n)->pos >= KEYLENGTH)
117#define IS_TNODE(n) ((n)->bits)
118#define IS_LEAF(n) (!(n)->bits)
119
120struct key_vector {
121 t_key key;
122 unsigned char pos; /* 2log(KEYLENGTH) bits needed */
123 unsigned char bits; /* 2log(KEYLENGTH) bits needed */
124 unsigned char slen;
125 union {
126 /* This list pointer if valid if (pos | bits) == 0 (LEAF) */
127 struct hlist_head leaf;
128 /* This array is valid if (pos | bits) > 0 (TNODE) */
129 struct key_vector __rcu *tnode[0];
130 };
131};
132
133struct tnode {
134 struct rcu_head rcu;
135 t_key empty_children; /* KEYLENGTH bits needed */
136 t_key full_children; /* KEYLENGTH bits needed */
137 struct key_vector __rcu *parent;
138 struct key_vector kv[1];
139#define tn_bits kv[0].bits
140};
141
142#define TNODE_SIZE(n) offsetof(struct tnode, kv[0].tnode[n])
143#define LEAF_SIZE TNODE_SIZE(1)
144
145#ifdef CONFIG_IP_FIB_TRIE_STATS
146struct trie_use_stats {
147 unsigned int gets;
148 unsigned int backtrack;
149 unsigned int semantic_match_passed;
150 unsigned int semantic_match_miss;
151 unsigned int null_node_hit;
152 unsigned int resize_node_skipped;
153};
154#endif
155
156struct trie_stat {
157 unsigned int totdepth;
158 unsigned int maxdepth;
159 unsigned int tnodes;
160 unsigned int leaves;
161 unsigned int nullpointers;
162 unsigned int prefixes;
163 unsigned int nodesizes[MAX_STAT_DEPTH];
164};
165
166struct trie {
167 struct key_vector kv[1];
168#ifdef CONFIG_IP_FIB_TRIE_STATS
169 struct trie_use_stats __percpu *stats;
170#endif
171};
172
173static struct key_vector *resize(struct trie *t, struct key_vector *tn);
174static unsigned int tnode_free_size;
175
176/*
177 * synchronize_rcu after call_rcu for outstanding dirty memory; it should be
178 * especially useful before resizing the root node with PREEMPT_NONE configs;
179 * the value was obtained experimentally, aiming to avoid visible slowdown.
180 */
181unsigned int sysctl_fib_sync_mem = 512 * 1024;
182unsigned int sysctl_fib_sync_mem_min = 64 * 1024;
183unsigned int sysctl_fib_sync_mem_max = 64 * 1024 * 1024;
184
185static struct kmem_cache *fn_alias_kmem __ro_after_init;
186static struct kmem_cache *trie_leaf_kmem __ro_after_init;
187
188static inline struct tnode *tn_info(struct key_vector *kv)
189{
190 return container_of(kv, struct tnode, kv[0]);
191}
192
193/* caller must hold RTNL */
194#define node_parent(tn) rtnl_dereference(tn_info(tn)->parent)
195#define get_child(tn, i) rtnl_dereference((tn)->tnode[i])
196
197/* caller must hold RCU read lock or RTNL */
198#define node_parent_rcu(tn) rcu_dereference_rtnl(tn_info(tn)->parent)
199#define get_child_rcu(tn, i) rcu_dereference_rtnl((tn)->tnode[i])
200
201/* wrapper for rcu_assign_pointer */
202static inline void node_set_parent(struct key_vector *n, struct key_vector *tp)
203{
204 if (n)
205 rcu_assign_pointer(tn_info(n)->parent, tp);
206}
207
208#define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER(tn_info(n)->parent, p)
209
210/* This provides us with the number of children in this node, in the case of a
211 * leaf this will return 0 meaning none of the children are accessible.
212 */
213static inline unsigned long child_length(const struct key_vector *tn)
214{
215 return (1ul << tn->bits) & ~(1ul);
216}
217
218#define get_cindex(key, kv) (((key) ^ (kv)->key) >> (kv)->pos)
219
220static inline unsigned long get_index(t_key key, struct key_vector *kv)
221{
222 unsigned long index = key ^ kv->key;
223
224 if ((BITS_PER_LONG <= KEYLENGTH) && (KEYLENGTH == kv->pos))
225 return 0;
226
227 return index >> kv->pos;
228}
229
230/* To understand this stuff, an understanding of keys and all their bits is
231 * necessary. Every node in the trie has a key associated with it, but not
232 * all of the bits in that key are significant.
233 *
234 * Consider a node 'n' and its parent 'tp'.
235 *
236 * If n is a leaf, every bit in its key is significant. Its presence is
237 * necessitated by path compression, since during a tree traversal (when
238 * searching for a leaf - unless we are doing an insertion) we will completely
239 * ignore all skipped bits we encounter. Thus we need to verify, at the end of
240 * a potentially successful search, that we have indeed been walking the
241 * correct key path.
242 *
243 * Note that we can never "miss" the correct key in the tree if present by
244 * following the wrong path. Path compression ensures that segments of the key
245 * that are the same for all keys with a given prefix are skipped, but the
246 * skipped part *is* identical for each node in the subtrie below the skipped
247 * bit! trie_insert() in this implementation takes care of that.
248 *
249 * if n is an internal node - a 'tnode' here, the various parts of its key
250 * have many different meanings.
251 *
252 * Example:
253 * _________________________________________________________________
254 * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
255 * -----------------------------------------------------------------
256 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
257 *
258 * _________________________________________________________________
259 * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
260 * -----------------------------------------------------------------
261 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
262 *
263 * tp->pos = 22
264 * tp->bits = 3
265 * n->pos = 13
266 * n->bits = 4
267 *
268 * First, let's just ignore the bits that come before the parent tp, that is
269 * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this
270 * point we do not use them for anything.
271 *
272 * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the
273 * index into the parent's child array. That is, they will be used to find
274 * 'n' among tp's children.
275 *
276 * The bits from (n->pos + n->bits) to (tp->pos - 1) - "S" - are skipped bits
277 * for the node n.
278 *
279 * All the bits we have seen so far are significant to the node n. The rest
280 * of the bits are really not needed or indeed known in n->key.
281 *
282 * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into
283 * n's child array, and will of course be different for each child.
284 *
285 * The rest of the bits, from 0 to (n->pos -1) - "u" - are completely unknown
286 * at this point.
287 */
288
289static const int halve_threshold = 25;
290static const int inflate_threshold = 50;
291static const int halve_threshold_root = 15;
292static const int inflate_threshold_root = 30;
293
294static void __alias_free_mem(struct rcu_head *head)
295{
296 struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
297 kmem_cache_free(fn_alias_kmem, fa);
298}
299
300static inline void alias_free_mem_rcu(struct fib_alias *fa)
301{
302 call_rcu(&fa->rcu, __alias_free_mem);
303}
304
305#define TNODE_KMALLOC_MAX \
306 ilog2((PAGE_SIZE - TNODE_SIZE(0)) / sizeof(struct key_vector *))
307#define TNODE_VMALLOC_MAX \
308 ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *))
309
310static void __node_free_rcu(struct rcu_head *head)
311{
312 struct tnode *n = container_of(head, struct tnode, rcu);
313
314 if (!n->tn_bits)
315 kmem_cache_free(trie_leaf_kmem, n);
316 else
317 kvfree(n);
318}
319
320#define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu)
321
322static struct tnode *tnode_alloc(int bits)
323{
324 size_t size;
325
326 /* verify bits is within bounds */
327 if (bits > TNODE_VMALLOC_MAX)
328 return NULL;
329
330 /* determine size and verify it is non-zero and didn't overflow */
331 size = TNODE_SIZE(1ul << bits);
332
333 if (size <= PAGE_SIZE)
334 return kzalloc(size, GFP_KERNEL);
335 else
336 return vzalloc(size);
337}
338
339static inline void empty_child_inc(struct key_vector *n)
340{
341 tn_info(n)->empty_children++;
342
343 if (!tn_info(n)->empty_children)
344 tn_info(n)->full_children++;
345}
346
347static inline void empty_child_dec(struct key_vector *n)
348{
349 if (!tn_info(n)->empty_children)
350 tn_info(n)->full_children--;
351
352 tn_info(n)->empty_children--;
353}
354
355static struct key_vector *leaf_new(t_key key, struct fib_alias *fa)
356{
357 struct key_vector *l;
358 struct tnode *kv;
359
360 kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
361 if (!kv)
362 return NULL;
363
364 /* initialize key vector */
365 l = kv->kv;
366 l->key = key;
367 l->pos = 0;
368 l->bits = 0;
369 l->slen = fa->fa_slen;
370
371 /* link leaf to fib alias */
372 INIT_HLIST_HEAD(&l->leaf);
373 hlist_add_head(&fa->fa_list, &l->leaf);
374
375 return l;
376}
377
378static struct key_vector *tnode_new(t_key key, int pos, int bits)
379{
380 unsigned int shift = pos + bits;
381 struct key_vector *tn;
382 struct tnode *tnode;
383
384 /* verify bits and pos their msb bits clear and values are valid */
385 BUG_ON(!bits || (shift > KEYLENGTH));
386
387 tnode = tnode_alloc(bits);
388 if (!tnode)
389 return NULL;
390
391 pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0),
392 sizeof(struct key_vector *) << bits);
393
394 if (bits == KEYLENGTH)
395 tnode->full_children = 1;
396 else
397 tnode->empty_children = 1ul << bits;
398
399 tn = tnode->kv;
400 tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
401 tn->pos = pos;
402 tn->bits = bits;
403 tn->slen = pos;
404
405 return tn;
406}
407
408/* Check whether a tnode 'n' is "full", i.e. it is an internal node
409 * and no bits are skipped. See discussion in dyntree paper p. 6
410 */
411static inline int tnode_full(struct key_vector *tn, struct key_vector *n)
412{
413 return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n);
414}
415
416/* Add a child at position i overwriting the old value.
417 * Update the value of full_children and empty_children.
418 */
419static void put_child(struct key_vector *tn, unsigned long i,
420 struct key_vector *n)
421{
422 struct key_vector *chi = get_child(tn, i);
423 int isfull, wasfull;
424
425 BUG_ON(i >= child_length(tn));
426
427 /* update emptyChildren, overflow into fullChildren */
428 if (!n && chi)
429 empty_child_inc(tn);
430 if (n && !chi)
431 empty_child_dec(tn);
432
433 /* update fullChildren */
434 wasfull = tnode_full(tn, chi);
435 isfull = tnode_full(tn, n);
436
437 if (wasfull && !isfull)
438 tn_info(tn)->full_children--;
439 else if (!wasfull && isfull)
440 tn_info(tn)->full_children++;
441
442 if (n && (tn->slen < n->slen))
443 tn->slen = n->slen;
444
445 rcu_assign_pointer(tn->tnode[i], n);
446}
447
448static void update_children(struct key_vector *tn)
449{
450 unsigned long i;
451
452 /* update all of the child parent pointers */
453 for (i = child_length(tn); i;) {
454 struct key_vector *inode = get_child(tn, --i);
455
456 if (!inode)
457 continue;
458
459 /* Either update the children of a tnode that
460 * already belongs to us or update the child
461 * to point to ourselves.
462 */
463 if (node_parent(inode) == tn)
464 update_children(inode);
465 else
466 node_set_parent(inode, tn);
467 }
468}
469
470static inline void put_child_root(struct key_vector *tp, t_key key,
471 struct key_vector *n)
472{
473 if (IS_TRIE(tp))
474 rcu_assign_pointer(tp->tnode[0], n);
475 else
476 put_child(tp, get_index(key, tp), n);
477}
478
479static inline void tnode_free_init(struct key_vector *tn)
480{
481 tn_info(tn)->rcu.next = NULL;
482}
483
484static inline void tnode_free_append(struct key_vector *tn,
485 struct key_vector *n)
486{
487 tn_info(n)->rcu.next = tn_info(tn)->rcu.next;
488 tn_info(tn)->rcu.next = &tn_info(n)->rcu;
489}
490
491static void tnode_free(struct key_vector *tn)
492{
493 struct callback_head *head = &tn_info(tn)->rcu;
494
495 while (head) {
496 head = head->next;
497 tnode_free_size += TNODE_SIZE(1ul << tn->bits);
498 node_free(tn);
499
500 tn = container_of(head, struct tnode, rcu)->kv;
501 }
502
503 if (tnode_free_size >= sysctl_fib_sync_mem) {
504 tnode_free_size = 0;
505 synchronize_rcu();
506 }
507}
508
509static struct key_vector *replace(struct trie *t,
510 struct key_vector *oldtnode,
511 struct key_vector *tn)
512{
513 struct key_vector *tp = node_parent(oldtnode);
514 unsigned long i;
515
516 /* setup the parent pointer out of and back into this node */
517 NODE_INIT_PARENT(tn, tp);
518 put_child_root(tp, tn->key, tn);
519
520 /* update all of the child parent pointers */
521 update_children(tn);
522
523 /* all pointers should be clean so we are done */
524 tnode_free(oldtnode);
525
526 /* resize children now that oldtnode is freed */
527 for (i = child_length(tn); i;) {
528 struct key_vector *inode = get_child(tn, --i);
529
530 /* resize child node */
531 if (tnode_full(tn, inode))
532 tn = resize(t, inode);
533 }
534
535 return tp;
536}
537
538static struct key_vector *inflate(struct trie *t,
539 struct key_vector *oldtnode)
540{
541 struct key_vector *tn;
542 unsigned long i;
543 t_key m;
544
545 pr_debug("In inflate\n");
546
547 tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1);
548 if (!tn)
549 goto notnode;
550
551 /* prepare oldtnode to be freed */
552 tnode_free_init(oldtnode);
553
554 /* Assemble all of the pointers in our cluster, in this case that
555 * represents all of the pointers out of our allocated nodes that
556 * point to existing tnodes and the links between our allocated
557 * nodes.
558 */
559 for (i = child_length(oldtnode), m = 1u << tn->pos; i;) {
560 struct key_vector *inode = get_child(oldtnode, --i);
561 struct key_vector *node0, *node1;
562 unsigned long j, k;
563
564 /* An empty child */
565 if (!inode)
566 continue;
567
568 /* A leaf or an internal node with skipped bits */
569 if (!tnode_full(oldtnode, inode)) {
570 put_child(tn, get_index(inode->key, tn), inode);
571 continue;
572 }
573
574 /* drop the node in the old tnode free list */
575 tnode_free_append(oldtnode, inode);
576
577 /* An internal node with two children */
578 if (inode->bits == 1) {
579 put_child(tn, 2 * i + 1, get_child(inode, 1));
580 put_child(tn, 2 * i, get_child(inode, 0));
581 continue;
582 }
583
584 /* We will replace this node 'inode' with two new
585 * ones, 'node0' and 'node1', each with half of the
586 * original children. The two new nodes will have
587 * a position one bit further down the key and this
588 * means that the "significant" part of their keys
589 * (see the discussion near the top of this file)
590 * will differ by one bit, which will be "0" in
591 * node0's key and "1" in node1's key. Since we are
592 * moving the key position by one step, the bit that
593 * we are moving away from - the bit at position
594 * (tn->pos) - is the one that will differ between
595 * node0 and node1. So... we synthesize that bit in the
596 * two new keys.
597 */
598 node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1);
599 if (!node1)
600 goto nomem;
601 node0 = tnode_new(inode->key, inode->pos, inode->bits - 1);
602
603 tnode_free_append(tn, node1);
604 if (!node0)
605 goto nomem;
606 tnode_free_append(tn, node0);
607
608 /* populate child pointers in new nodes */
609 for (k = child_length(inode), j = k / 2; j;) {
610 put_child(node1, --j, get_child(inode, --k));
611 put_child(node0, j, get_child(inode, j));
612 put_child(node1, --j, get_child(inode, --k));
613 put_child(node0, j, get_child(inode, j));
614 }
615
616 /* link new nodes to parent */
617 NODE_INIT_PARENT(node1, tn);
618 NODE_INIT_PARENT(node0, tn);
619
620 /* link parent to nodes */
621 put_child(tn, 2 * i + 1, node1);
622 put_child(tn, 2 * i, node0);
623 }
624
625 /* setup the parent pointers into and out of this node */
626 return replace(t, oldtnode, tn);
627nomem:
628 /* all pointers should be clean so we are done */
629 tnode_free(tn);
630notnode:
631 return NULL;
632}
633
634static struct key_vector *halve(struct trie *t,
635 struct key_vector *oldtnode)
636{
637 struct key_vector *tn;
638 unsigned long i;
639
640 pr_debug("In halve\n");
641
642 tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1);
643 if (!tn)
644 goto notnode;
645
646 /* prepare oldtnode to be freed */
647 tnode_free_init(oldtnode);
648
649 /* Assemble all of the pointers in our cluster, in this case that
650 * represents all of the pointers out of our allocated nodes that
651 * point to existing tnodes and the links between our allocated
652 * nodes.
653 */
654 for (i = child_length(oldtnode); i;) {
655 struct key_vector *node1 = get_child(oldtnode, --i);
656 struct key_vector *node0 = get_child(oldtnode, --i);
657 struct key_vector *inode;
658
659 /* At least one of the children is empty */
660 if (!node1 || !node0) {
661 put_child(tn, i / 2, node1 ? : node0);
662 continue;
663 }
664
665 /* Two nonempty children */
666 inode = tnode_new(node0->key, oldtnode->pos, 1);
667 if (!inode)
668 goto nomem;
669 tnode_free_append(tn, inode);
670
671 /* initialize pointers out of node */
672 put_child(inode, 1, node1);
673 put_child(inode, 0, node0);
674 NODE_INIT_PARENT(inode, tn);
675
676 /* link parent to node */
677 put_child(tn, i / 2, inode);
678 }
679
680 /* setup the parent pointers into and out of this node */
681 return replace(t, oldtnode, tn);
682nomem:
683 /* all pointers should be clean so we are done */
684 tnode_free(tn);
685notnode:
686 return NULL;
687}
688
689static struct key_vector *collapse(struct trie *t,
690 struct key_vector *oldtnode)
691{
692 struct key_vector *n, *tp;
693 unsigned long i;
694
695 /* scan the tnode looking for that one child that might still exist */
696 for (n = NULL, i = child_length(oldtnode); !n && i;)
697 n = get_child(oldtnode, --i);
698
699 /* compress one level */
700 tp = node_parent(oldtnode);
701 put_child_root(tp, oldtnode->key, n);
702 node_set_parent(n, tp);
703
704 /* drop dead node */
705 node_free(oldtnode);
706
707 return tp;
708}
709
710static unsigned char update_suffix(struct key_vector *tn)
711{
712 unsigned char slen = tn->pos;
713 unsigned long stride, i;
714 unsigned char slen_max;
715
716 /* only vector 0 can have a suffix length greater than or equal to
717 * tn->pos + tn->bits, the second highest node will have a suffix
718 * length at most of tn->pos + tn->bits - 1
719 */
720 slen_max = min_t(unsigned char, tn->pos + tn->bits - 1, tn->slen);
721
722 /* search though the list of children looking for nodes that might
723 * have a suffix greater than the one we currently have. This is
724 * why we start with a stride of 2 since a stride of 1 would
725 * represent the nodes with suffix length equal to tn->pos
726 */
727 for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) {
728 struct key_vector *n = get_child(tn, i);
729
730 if (!n || (n->slen <= slen))
731 continue;
732
733 /* update stride and slen based on new value */
734 stride <<= (n->slen - slen);
735 slen = n->slen;
736 i &= ~(stride - 1);
737
738 /* stop searching if we have hit the maximum possible value */
739 if (slen >= slen_max)
740 break;
741 }
742
743 tn->slen = slen;
744
745 return slen;
746}
747
748/* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
749 * the Helsinki University of Technology and Matti Tikkanen of Nokia
750 * Telecommunications, page 6:
751 * "A node is doubled if the ratio of non-empty children to all
752 * children in the *doubled* node is at least 'high'."
753 *
754 * 'high' in this instance is the variable 'inflate_threshold'. It
755 * is expressed as a percentage, so we multiply it with
756 * child_length() and instead of multiplying by 2 (since the
757 * child array will be doubled by inflate()) and multiplying
758 * the left-hand side by 100 (to handle the percentage thing) we
759 * multiply the left-hand side by 50.
760 *
761 * The left-hand side may look a bit weird: child_length(tn)
762 * - tn->empty_children is of course the number of non-null children
763 * in the current node. tn->full_children is the number of "full"
764 * children, that is non-null tnodes with a skip value of 0.
765 * All of those will be doubled in the resulting inflated tnode, so
766 * we just count them one extra time here.
767 *
768 * A clearer way to write this would be:
769 *
770 * to_be_doubled = tn->full_children;
771 * not_to_be_doubled = child_length(tn) - tn->empty_children -
772 * tn->full_children;
773 *
774 * new_child_length = child_length(tn) * 2;
775 *
776 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
777 * new_child_length;
778 * if (new_fill_factor >= inflate_threshold)
779 *
780 * ...and so on, tho it would mess up the while () loop.
781 *
782 * anyway,
783 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
784 * inflate_threshold
785 *
786 * avoid a division:
787 * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
788 * inflate_threshold * new_child_length
789 *
790 * expand not_to_be_doubled and to_be_doubled, and shorten:
791 * 100 * (child_length(tn) - tn->empty_children +
792 * tn->full_children) >= inflate_threshold * new_child_length
793 *
794 * expand new_child_length:
795 * 100 * (child_length(tn) - tn->empty_children +
796 * tn->full_children) >=
797 * inflate_threshold * child_length(tn) * 2
798 *
799 * shorten again:
800 * 50 * (tn->full_children + child_length(tn) -
801 * tn->empty_children) >= inflate_threshold *
802 * child_length(tn)
803 *
804 */
805static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn)
806{
807 unsigned long used = child_length(tn);
808 unsigned long threshold = used;
809
810 /* Keep root node larger */
811 threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold;
812 used -= tn_info(tn)->empty_children;
813 used += tn_info(tn)->full_children;
814
815 /* if bits == KEYLENGTH then pos = 0, and will fail below */
816
817 return (used > 1) && tn->pos && ((50 * used) >= threshold);
818}
819
820static inline bool should_halve(struct key_vector *tp, struct key_vector *tn)
821{
822 unsigned long used = child_length(tn);
823 unsigned long threshold = used;
824
825 /* Keep root node larger */
826 threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold;
827 used -= tn_info(tn)->empty_children;
828
829 /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */
830
831 return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold);
832}
833
834static inline bool should_collapse(struct key_vector *tn)
835{
836 unsigned long used = child_length(tn);
837
838 used -= tn_info(tn)->empty_children;
839
840 /* account for bits == KEYLENGTH case */
841 if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children)
842 used -= KEY_MAX;
843
844 /* One child or none, time to drop us from the trie */
845 return used < 2;
846}
847
848#define MAX_WORK 10
849static struct key_vector *resize(struct trie *t, struct key_vector *tn)
850{
851#ifdef CONFIG_IP_FIB_TRIE_STATS
852 struct trie_use_stats __percpu *stats = t->stats;
853#endif
854 struct key_vector *tp = node_parent(tn);
855 unsigned long cindex = get_index(tn->key, tp);
856 int max_work = MAX_WORK;
857
858 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
859 tn, inflate_threshold, halve_threshold);
860
861 /* track the tnode via the pointer from the parent instead of
862 * doing it ourselves. This way we can let RCU fully do its
863 * thing without us interfering
864 */
865 BUG_ON(tn != get_child(tp, cindex));
866
867 /* Double as long as the resulting node has a number of
868 * nonempty nodes that are above the threshold.
869 */
870 while (should_inflate(tp, tn) && max_work) {
871 tp = inflate(t, tn);
872 if (!tp) {
873#ifdef CONFIG_IP_FIB_TRIE_STATS
874 this_cpu_inc(stats->resize_node_skipped);
875#endif
876 break;
877 }
878
879 max_work--;
880 tn = get_child(tp, cindex);
881 }
882
883 /* update parent in case inflate failed */
884 tp = node_parent(tn);
885
886 /* Return if at least one inflate is run */
887 if (max_work != MAX_WORK)
888 return tp;
889
890 /* Halve as long as the number of empty children in this
891 * node is above threshold.
892 */
893 while (should_halve(tp, tn) && max_work) {
894 tp = halve(t, tn);
895 if (!tp) {
896#ifdef CONFIG_IP_FIB_TRIE_STATS
897 this_cpu_inc(stats->resize_node_skipped);
898#endif
899 break;
900 }
901
902 max_work--;
903 tn = get_child(tp, cindex);
904 }
905
906 /* Only one child remains */
907 if (should_collapse(tn))
908 return collapse(t, tn);
909
910 /* update parent in case halve failed */
911 return node_parent(tn);
912}
913
914static void node_pull_suffix(struct key_vector *tn, unsigned char slen)
915{
916 unsigned char node_slen = tn->slen;
917
918 while ((node_slen > tn->pos) && (node_slen > slen)) {
919 slen = update_suffix(tn);
920 if (node_slen == slen)
921 break;
922
923 tn = node_parent(tn);
924 node_slen = tn->slen;
925 }
926}
927
928static void node_push_suffix(struct key_vector *tn, unsigned char slen)
929{
930 while (tn->slen < slen) {
931 tn->slen = slen;
932 tn = node_parent(tn);
933 }
934}
935
936/* rcu_read_lock needs to be hold by caller from readside */
937static struct key_vector *fib_find_node(struct trie *t,
938 struct key_vector **tp, u32 key)
939{
940 struct key_vector *pn, *n = t->kv;
941 unsigned long index = 0;
942
943 do {
944 pn = n;
945 n = get_child_rcu(n, index);
946
947 if (!n)
948 break;
949
950 index = get_cindex(key, n);
951
952 /* This bit of code is a bit tricky but it combines multiple
953 * checks into a single check. The prefix consists of the
954 * prefix plus zeros for the bits in the cindex. The index
955 * is the difference between the key and this value. From
956 * this we can actually derive several pieces of data.
957 * if (index >= (1ul << bits))
958 * we have a mismatch in skip bits and failed
959 * else
960 * we know the value is cindex
961 *
962 * This check is safe even if bits == KEYLENGTH due to the
963 * fact that we can only allocate a node with 32 bits if a
964 * long is greater than 32 bits.
965 */
966 if (index >= (1ul << n->bits)) {
967 n = NULL;
968 break;
969 }
970
971 /* keep searching until we find a perfect match leaf or NULL */
972 } while (IS_TNODE(n));
973
974 *tp = pn;
975
976 return n;
977}
978
979/* Return the first fib alias matching TOS with
980 * priority less than or equal to PRIO.
981 */
982static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen,
983 u8 tos, u32 prio, u32 tb_id)
984{
985 struct fib_alias *fa;
986
987 if (!fah)
988 return NULL;
989
990 hlist_for_each_entry(fa, fah, fa_list) {
991 if (fa->fa_slen < slen)
992 continue;
993 if (fa->fa_slen != slen)
994 break;
995 if (fa->tb_id > tb_id)
996 continue;
997 if (fa->tb_id != tb_id)
998 break;
999 if (fa->fa_tos > tos)
1000 continue;
1001 if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos)
1002 return fa;
1003 }
1004
1005 return NULL;
1006}
1007
1008static void trie_rebalance(struct trie *t, struct key_vector *tn)
1009{
1010 while (!IS_TRIE(tn))
1011 tn = resize(t, tn);
1012}
1013
1014static int fib_insert_node(struct trie *t, struct key_vector *tp,
1015 struct fib_alias *new, t_key key)
1016{
1017 struct key_vector *n, *l;
1018
1019 l = leaf_new(key, new);
1020 if (!l)
1021 goto noleaf;
1022
1023 /* retrieve child from parent node */
1024 n = get_child(tp, get_index(key, tp));
1025
1026 /* Case 2: n is a LEAF or a TNODE and the key doesn't match.
1027 *
1028 * Add a new tnode here
1029 * first tnode need some special handling
1030 * leaves us in position for handling as case 3
1031 */
1032 if (n) {
1033 struct key_vector *tn;
1034
1035 tn = tnode_new(key, __fls(key ^ n->key), 1);
1036 if (!tn)
1037 goto notnode;
1038
1039 /* initialize routes out of node */
1040 NODE_INIT_PARENT(tn, tp);
1041 put_child(tn, get_index(key, tn) ^ 1, n);
1042
1043 /* start adding routes into the node */
1044 put_child_root(tp, key, tn);
1045 node_set_parent(n, tn);
1046
1047 /* parent now has a NULL spot where the leaf can go */
1048 tp = tn;
1049 }
1050
1051 /* Case 3: n is NULL, and will just insert a new leaf */
1052 node_push_suffix(tp, new->fa_slen);
1053 NODE_INIT_PARENT(l, tp);
1054 put_child_root(tp, key, l);
1055 trie_rebalance(t, tp);
1056
1057 return 0;
1058notnode:
1059 node_free(l);
1060noleaf:
1061 return -ENOMEM;
1062}
1063
1064/* fib notifier for ADD is sent before calling fib_insert_alias with
1065 * the expectation that the only possible failure ENOMEM
1066 */
1067static int fib_insert_alias(struct trie *t, struct key_vector *tp,
1068 struct key_vector *l, struct fib_alias *new,
1069 struct fib_alias *fa, t_key key)
1070{
1071 if (!l)
1072 return fib_insert_node(t, tp, new, key);
1073
1074 if (fa) {
1075 hlist_add_before_rcu(&new->fa_list, &fa->fa_list);
1076 } else {
1077 struct fib_alias *last;
1078
1079 hlist_for_each_entry(last, &l->leaf, fa_list) {
1080 if (new->fa_slen < last->fa_slen)
1081 break;
1082 if ((new->fa_slen == last->fa_slen) &&
1083 (new->tb_id > last->tb_id))
1084 break;
1085 fa = last;
1086 }
1087
1088 if (fa)
1089 hlist_add_behind_rcu(&new->fa_list, &fa->fa_list);
1090 else
1091 hlist_add_head_rcu(&new->fa_list, &l->leaf);
1092 }
1093
1094 /* if we added to the tail node then we need to update slen */
1095 if (l->slen < new->fa_slen) {
1096 l->slen = new->fa_slen;
1097 node_push_suffix(tp, new->fa_slen);
1098 }
1099
1100 return 0;
1101}
1102
1103static bool fib_valid_key_len(u32 key, u8 plen, struct netlink_ext_ack *extack)
1104{
1105 if (plen > KEYLENGTH) {
1106 NL_SET_ERR_MSG(extack, "Invalid prefix length");
1107 return false;
1108 }
1109
1110 if ((plen < KEYLENGTH) && (key << plen)) {
1111 NL_SET_ERR_MSG(extack,
1112 "Invalid prefix for given prefix length");
1113 return false;
1114 }
1115
1116 return true;
1117}
1118
1119/* Caller must hold RTNL. */
1120int fib_table_insert(struct net *net, struct fib_table *tb,
1121 struct fib_config *cfg, struct netlink_ext_ack *extack)
1122{
1123 enum fib_event_type event = FIB_EVENT_ENTRY_ADD;
1124 struct trie *t = (struct trie *)tb->tb_data;
1125 struct fib_alias *fa, *new_fa;
1126 struct key_vector *l, *tp;
1127 u16 nlflags = NLM_F_EXCL;
1128 struct fib_info *fi;
1129 u8 plen = cfg->fc_dst_len;
1130 u8 slen = KEYLENGTH - plen;
1131 u8 tos = cfg->fc_tos;
1132 u32 key;
1133 int err;
1134
1135 key = ntohl(cfg->fc_dst);
1136
1137 if (!fib_valid_key_len(key, plen, extack))
1138 return -EINVAL;
1139
1140 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
1141
1142 fi = fib_create_info(cfg, extack);
1143 if (IS_ERR(fi)) {
1144 err = PTR_ERR(fi);
1145 goto err;
1146 }
1147
1148 l = fib_find_node(t, &tp, key);
1149 fa = l ? fib_find_alias(&l->leaf, slen, tos, fi->fib_priority,
1150 tb->tb_id) : NULL;
1151
1152 /* Now fa, if non-NULL, points to the first fib alias
1153 * with the same keys [prefix,tos,priority], if such key already
1154 * exists or to the node before which we will insert new one.
1155 *
1156 * If fa is NULL, we will need to allocate a new one and
1157 * insert to the tail of the section matching the suffix length
1158 * of the new alias.
1159 */
1160
1161 if (fa && fa->fa_tos == tos &&
1162 fa->fa_info->fib_priority == fi->fib_priority) {
1163 struct fib_alias *fa_first, *fa_match;
1164
1165 err = -EEXIST;
1166 if (cfg->fc_nlflags & NLM_F_EXCL)
1167 goto out;
1168
1169 nlflags &= ~NLM_F_EXCL;
1170
1171 /* We have 2 goals:
1172 * 1. Find exact match for type, scope, fib_info to avoid
1173 * duplicate routes
1174 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
1175 */
1176 fa_match = NULL;
1177 fa_first = fa;
1178 hlist_for_each_entry_from(fa, fa_list) {
1179 if ((fa->fa_slen != slen) ||
1180 (fa->tb_id != tb->tb_id) ||
1181 (fa->fa_tos != tos))
1182 break;
1183 if (fa->fa_info->fib_priority != fi->fib_priority)
1184 break;
1185 if (fa->fa_type == cfg->fc_type &&
1186 fa->fa_info == fi) {
1187 fa_match = fa;
1188 break;
1189 }
1190 }
1191
1192 if (cfg->fc_nlflags & NLM_F_REPLACE) {
1193 struct fib_info *fi_drop;
1194 u8 state;
1195
1196 nlflags |= NLM_F_REPLACE;
1197 fa = fa_first;
1198 if (fa_match) {
1199 if (fa == fa_match)
1200 err = 0;
1201 goto out;
1202 }
1203 err = -ENOBUFS;
1204 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1205 if (!new_fa)
1206 goto out;
1207
1208 fi_drop = fa->fa_info;
1209 new_fa->fa_tos = fa->fa_tos;
1210 new_fa->fa_info = fi;
1211 new_fa->fa_type = cfg->fc_type;
1212 state = fa->fa_state;
1213 new_fa->fa_state = state & ~FA_S_ACCESSED;
1214 new_fa->fa_slen = fa->fa_slen;
1215 new_fa->tb_id = tb->tb_id;
1216 new_fa->fa_default = -1;
1217
1218 err = call_fib_entry_notifiers(net,
1219 FIB_EVENT_ENTRY_REPLACE,
1220 key, plen, new_fa,
1221 extack);
1222 if (err)
1223 goto out_free_new_fa;
1224
1225 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
1226 tb->tb_id, &cfg->fc_nlinfo, nlflags);
1227
1228 hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list);
1229
1230 alias_free_mem_rcu(fa);
1231
1232 fib_release_info(fi_drop);
1233 if (state & FA_S_ACCESSED)
1234 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1235
1236 goto succeeded;
1237 }
1238 /* Error if we find a perfect match which
1239 * uses the same scope, type, and nexthop
1240 * information.
1241 */
1242 if (fa_match)
1243 goto out;
1244
1245 if (cfg->fc_nlflags & NLM_F_APPEND) {
1246 event = FIB_EVENT_ENTRY_APPEND;
1247 nlflags |= NLM_F_APPEND;
1248 } else {
1249 fa = fa_first;
1250 }
1251 }
1252 err = -ENOENT;
1253 if (!(cfg->fc_nlflags & NLM_F_CREATE))
1254 goto out;
1255
1256 nlflags |= NLM_F_CREATE;
1257 err = -ENOBUFS;
1258 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1259 if (!new_fa)
1260 goto out;
1261
1262 new_fa->fa_info = fi;
1263 new_fa->fa_tos = tos;
1264 new_fa->fa_type = cfg->fc_type;
1265 new_fa->fa_state = 0;
1266 new_fa->fa_slen = slen;
1267 new_fa->tb_id = tb->tb_id;
1268 new_fa->fa_default = -1;
1269
1270 err = call_fib_entry_notifiers(net, event, key, plen, new_fa, extack);
1271 if (err)
1272 goto out_free_new_fa;
1273
1274 /* Insert new entry to the list. */
1275 err = fib_insert_alias(t, tp, l, new_fa, fa, key);
1276 if (err)
1277 goto out_fib_notif;
1278
1279 if (!plen)
1280 tb->tb_num_default++;
1281
1282 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1283 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id,
1284 &cfg->fc_nlinfo, nlflags);
1285succeeded:
1286 return 0;
1287
1288out_fib_notif:
1289 /* notifier was sent that entry would be added to trie, but
1290 * the add failed and need to recover. Only failure for
1291 * fib_insert_alias is ENOMEM.
1292 */
1293 NL_SET_ERR_MSG(extack, "Failed to insert route into trie");
1294 call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, key,
1295 plen, new_fa, NULL);
1296out_free_new_fa:
1297 kmem_cache_free(fn_alias_kmem, new_fa);
1298out:
1299 fib_release_info(fi);
1300err:
1301 return err;
1302}
1303
1304static inline t_key prefix_mismatch(t_key key, struct key_vector *n)
1305{
1306 t_key prefix = n->key;
1307
1308 return (key ^ prefix) & (prefix | -prefix);
1309}
1310
1311/* should be called with rcu_read_lock */
1312int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
1313 struct fib_result *res, int fib_flags)
1314{
1315 struct trie *t = (struct trie *) tb->tb_data;
1316#ifdef CONFIG_IP_FIB_TRIE_STATS
1317 struct trie_use_stats __percpu *stats = t->stats;
1318#endif
1319 const t_key key = ntohl(flp->daddr);
1320 struct key_vector *n, *pn;
1321 struct fib_alias *fa;
1322 unsigned long index;
1323 t_key cindex;
1324
1325 pn = t->kv;
1326 cindex = 0;
1327
1328 n = get_child_rcu(pn, cindex);
1329 if (!n) {
1330 trace_fib_table_lookup(tb->tb_id, flp, NULL, -EAGAIN);
1331 return -EAGAIN;
1332 }
1333
1334#ifdef CONFIG_IP_FIB_TRIE_STATS
1335 this_cpu_inc(stats->gets);
1336#endif
1337
1338 /* Step 1: Travel to the longest prefix match in the trie */
1339 for (;;) {
1340 index = get_cindex(key, n);
1341
1342 /* This bit of code is a bit tricky but it combines multiple
1343 * checks into a single check. The prefix consists of the
1344 * prefix plus zeros for the "bits" in the prefix. The index
1345 * is the difference between the key and this value. From
1346 * this we can actually derive several pieces of data.
1347 * if (index >= (1ul << bits))
1348 * we have a mismatch in skip bits and failed
1349 * else
1350 * we know the value is cindex
1351 *
1352 * This check is safe even if bits == KEYLENGTH due to the
1353 * fact that we can only allocate a node with 32 bits if a
1354 * long is greater than 32 bits.
1355 */
1356 if (index >= (1ul << n->bits))
1357 break;
1358
1359 /* we have found a leaf. Prefixes have already been compared */
1360 if (IS_LEAF(n))
1361 goto found;
1362
1363 /* only record pn and cindex if we are going to be chopping
1364 * bits later. Otherwise we are just wasting cycles.
1365 */
1366 if (n->slen > n->pos) {
1367 pn = n;
1368 cindex = index;
1369 }
1370
1371 n = get_child_rcu(n, index);
1372 if (unlikely(!n))
1373 goto backtrace;
1374 }
1375
1376 /* Step 2: Sort out leaves and begin backtracing for longest prefix */
1377 for (;;) {
1378 /* record the pointer where our next node pointer is stored */
1379 struct key_vector __rcu **cptr = n->tnode;
1380
1381 /* This test verifies that none of the bits that differ
1382 * between the key and the prefix exist in the region of
1383 * the lsb and higher in the prefix.
1384 */
1385 if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos))
1386 goto backtrace;
1387
1388 /* exit out and process leaf */
1389 if (unlikely(IS_LEAF(n)))
1390 break;
1391
1392 /* Don't bother recording parent info. Since we are in
1393 * prefix match mode we will have to come back to wherever
1394 * we started this traversal anyway
1395 */
1396
1397 while ((n = rcu_dereference(*cptr)) == NULL) {
1398backtrace:
1399#ifdef CONFIG_IP_FIB_TRIE_STATS
1400 if (!n)
1401 this_cpu_inc(stats->null_node_hit);
1402#endif
1403 /* If we are at cindex 0 there are no more bits for
1404 * us to strip at this level so we must ascend back
1405 * up one level to see if there are any more bits to
1406 * be stripped there.
1407 */
1408 while (!cindex) {
1409 t_key pkey = pn->key;
1410
1411 /* If we don't have a parent then there is
1412 * nothing for us to do as we do not have any
1413 * further nodes to parse.
1414 */
1415 if (IS_TRIE(pn)) {
1416 trace_fib_table_lookup(tb->tb_id, flp,
1417 NULL, -EAGAIN);
1418 return -EAGAIN;
1419 }
1420#ifdef CONFIG_IP_FIB_TRIE_STATS
1421 this_cpu_inc(stats->backtrack);
1422#endif
1423 /* Get Child's index */
1424 pn = node_parent_rcu(pn);
1425 cindex = get_index(pkey, pn);
1426 }
1427
1428 /* strip the least significant bit from the cindex */
1429 cindex &= cindex - 1;
1430
1431 /* grab pointer for next child node */
1432 cptr = &pn->tnode[cindex];
1433 }
1434 }
1435
1436found:
1437 /* this line carries forward the xor from earlier in the function */
1438 index = key ^ n->key;
1439
1440 /* Step 3: Process the leaf, if that fails fall back to backtracing */
1441 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
1442 struct fib_info *fi = fa->fa_info;
1443 int nhsel, err;
1444
1445 if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) {
1446 if (index >= (1ul << fa->fa_slen))
1447 continue;
1448 }
1449 if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
1450 continue;
1451 if (fi->fib_dead)
1452 continue;
1453 if (fa->fa_info->fib_scope < flp->flowi4_scope)
1454 continue;
1455 fib_alias_accessed(fa);
1456 err = fib_props[fa->fa_type].error;
1457 if (unlikely(err < 0)) {
1458out_reject:
1459#ifdef CONFIG_IP_FIB_TRIE_STATS
1460 this_cpu_inc(stats->semantic_match_passed);
1461#endif
1462 trace_fib_table_lookup(tb->tb_id, flp, NULL, err);
1463 return err;
1464 }
1465 if (fi->fib_flags & RTNH_F_DEAD)
1466 continue;
1467
1468 if (unlikely(fi->nh && nexthop_is_blackhole(fi->nh))) {
1469 err = fib_props[RTN_BLACKHOLE].error;
1470 goto out_reject;
1471 }
1472
1473 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) {
1474 struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel);
1475
1476 if (nhc->nhc_flags & RTNH_F_DEAD)
1477 continue;
1478 if (ip_ignore_linkdown(nhc->nhc_dev) &&
1479 nhc->nhc_flags & RTNH_F_LINKDOWN &&
1480 !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE))
1481 continue;
1482 if (!(flp->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) {
1483 if (flp->flowi4_oif &&
1484 flp->flowi4_oif != nhc->nhc_oif)
1485 continue;
1486 }
1487
1488 if (!(fib_flags & FIB_LOOKUP_NOREF))
1489 refcount_inc(&fi->fib_clntref);
1490
1491 res->prefix = htonl(n->key);
1492 res->prefixlen = KEYLENGTH - fa->fa_slen;
1493 res->nh_sel = nhsel;
1494 res->nhc = nhc;
1495 res->type = fa->fa_type;
1496 res->scope = fi->fib_scope;
1497 res->fi = fi;
1498 res->table = tb;
1499 res->fa_head = &n->leaf;
1500#ifdef CONFIG_IP_FIB_TRIE_STATS
1501 this_cpu_inc(stats->semantic_match_passed);
1502#endif
1503 trace_fib_table_lookup(tb->tb_id, flp, nhc, err);
1504
1505 return err;
1506 }
1507 }
1508#ifdef CONFIG_IP_FIB_TRIE_STATS
1509 this_cpu_inc(stats->semantic_match_miss);
1510#endif
1511 goto backtrace;
1512}
1513EXPORT_SYMBOL_GPL(fib_table_lookup);
1514
1515static void fib_remove_alias(struct trie *t, struct key_vector *tp,
1516 struct key_vector *l, struct fib_alias *old)
1517{
1518 /* record the location of the previous list_info entry */
1519 struct hlist_node **pprev = old->fa_list.pprev;
1520 struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next);
1521
1522 /* remove the fib_alias from the list */
1523 hlist_del_rcu(&old->fa_list);
1524
1525 /* if we emptied the list this leaf will be freed and we can sort
1526 * out parent suffix lengths as a part of trie_rebalance
1527 */
1528 if (hlist_empty(&l->leaf)) {
1529 if (tp->slen == l->slen)
1530 node_pull_suffix(tp, tp->pos);
1531 put_child_root(tp, l->key, NULL);
1532 node_free(l);
1533 trie_rebalance(t, tp);
1534 return;
1535 }
1536
1537 /* only access fa if it is pointing at the last valid hlist_node */
1538 if (*pprev)
1539 return;
1540
1541 /* update the trie with the latest suffix length */
1542 l->slen = fa->fa_slen;
1543 node_pull_suffix(tp, fa->fa_slen);
1544}
1545
1546/* Caller must hold RTNL. */
1547int fib_table_delete(struct net *net, struct fib_table *tb,
1548 struct fib_config *cfg, struct netlink_ext_ack *extack)
1549{
1550 struct trie *t = (struct trie *) tb->tb_data;
1551 struct fib_alias *fa, *fa_to_delete;
1552 struct key_vector *l, *tp;
1553 u8 plen = cfg->fc_dst_len;
1554 u8 slen = KEYLENGTH - plen;
1555 u8 tos = cfg->fc_tos;
1556 u32 key;
1557
1558 key = ntohl(cfg->fc_dst);
1559
1560 if (!fib_valid_key_len(key, plen, extack))
1561 return -EINVAL;
1562
1563 l = fib_find_node(t, &tp, key);
1564 if (!l)
1565 return -ESRCH;
1566
1567 fa = fib_find_alias(&l->leaf, slen, tos, 0, tb->tb_id);
1568 if (!fa)
1569 return -ESRCH;
1570
1571 pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
1572
1573 fa_to_delete = NULL;
1574 hlist_for_each_entry_from(fa, fa_list) {
1575 struct fib_info *fi = fa->fa_info;
1576
1577 if ((fa->fa_slen != slen) ||
1578 (fa->tb_id != tb->tb_id) ||
1579 (fa->fa_tos != tos))
1580 break;
1581
1582 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
1583 (cfg->fc_scope == RT_SCOPE_NOWHERE ||
1584 fa->fa_info->fib_scope == cfg->fc_scope) &&
1585 (!cfg->fc_prefsrc ||
1586 fi->fib_prefsrc == cfg->fc_prefsrc) &&
1587 (!cfg->fc_protocol ||
1588 fi->fib_protocol == cfg->fc_protocol) &&
1589 fib_nh_match(cfg, fi, extack) == 0 &&
1590 fib_metrics_match(cfg, fi)) {
1591 fa_to_delete = fa;
1592 break;
1593 }
1594 }
1595
1596 if (!fa_to_delete)
1597 return -ESRCH;
1598
1599 call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, key, plen,
1600 fa_to_delete, extack);
1601 rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id,
1602 &cfg->fc_nlinfo, 0);
1603
1604 if (!plen)
1605 tb->tb_num_default--;
1606
1607 fib_remove_alias(t, tp, l, fa_to_delete);
1608
1609 if (fa_to_delete->fa_state & FA_S_ACCESSED)
1610 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1611
1612 fib_release_info(fa_to_delete->fa_info);
1613 alias_free_mem_rcu(fa_to_delete);
1614 return 0;
1615}
1616
1617/* Scan for the next leaf starting at the provided key value */
1618static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key)
1619{
1620 struct key_vector *pn, *n = *tn;
1621 unsigned long cindex;
1622
1623 /* this loop is meant to try and find the key in the trie */
1624 do {
1625 /* record parent and next child index */
1626 pn = n;
1627 cindex = (key > pn->key) ? get_index(key, pn) : 0;
1628
1629 if (cindex >> pn->bits)
1630 break;
1631
1632 /* descend into the next child */
1633 n = get_child_rcu(pn, cindex++);
1634 if (!n)
1635 break;
1636
1637 /* guarantee forward progress on the keys */
1638 if (IS_LEAF(n) && (n->key >= key))
1639 goto found;
1640 } while (IS_TNODE(n));
1641
1642 /* this loop will search for the next leaf with a greater key */
1643 while (!IS_TRIE(pn)) {
1644 /* if we exhausted the parent node we will need to climb */
1645 if (cindex >= (1ul << pn->bits)) {
1646 t_key pkey = pn->key;
1647
1648 pn = node_parent_rcu(pn);
1649 cindex = get_index(pkey, pn) + 1;
1650 continue;
1651 }
1652
1653 /* grab the next available node */
1654 n = get_child_rcu(pn, cindex++);
1655 if (!n)
1656 continue;
1657
1658 /* no need to compare keys since we bumped the index */
1659 if (IS_LEAF(n))
1660 goto found;
1661
1662 /* Rescan start scanning in new node */
1663 pn = n;
1664 cindex = 0;
1665 }
1666
1667 *tn = pn;
1668 return NULL; /* Root of trie */
1669found:
1670 /* if we are at the limit for keys just return NULL for the tnode */
1671 *tn = pn;
1672 return n;
1673}
1674
1675static void fib_trie_free(struct fib_table *tb)
1676{
1677 struct trie *t = (struct trie *)tb->tb_data;
1678 struct key_vector *pn = t->kv;
1679 unsigned long cindex = 1;
1680 struct hlist_node *tmp;
1681 struct fib_alias *fa;
1682
1683 /* walk trie in reverse order and free everything */
1684 for (;;) {
1685 struct key_vector *n;
1686
1687 if (!(cindex--)) {
1688 t_key pkey = pn->key;
1689
1690 if (IS_TRIE(pn))
1691 break;
1692
1693 n = pn;
1694 pn = node_parent(pn);
1695
1696 /* drop emptied tnode */
1697 put_child_root(pn, n->key, NULL);
1698 node_free(n);
1699
1700 cindex = get_index(pkey, pn);
1701
1702 continue;
1703 }
1704
1705 /* grab the next available node */
1706 n = get_child(pn, cindex);
1707 if (!n)
1708 continue;
1709
1710 if (IS_TNODE(n)) {
1711 /* record pn and cindex for leaf walking */
1712 pn = n;
1713 cindex = 1ul << n->bits;
1714
1715 continue;
1716 }
1717
1718 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1719 hlist_del_rcu(&fa->fa_list);
1720 alias_free_mem_rcu(fa);
1721 }
1722
1723 put_child_root(pn, n->key, NULL);
1724 node_free(n);
1725 }
1726
1727#ifdef CONFIG_IP_FIB_TRIE_STATS
1728 free_percpu(t->stats);
1729#endif
1730 kfree(tb);
1731}
1732
1733struct fib_table *fib_trie_unmerge(struct fib_table *oldtb)
1734{
1735 struct trie *ot = (struct trie *)oldtb->tb_data;
1736 struct key_vector *l, *tp = ot->kv;
1737 struct fib_table *local_tb;
1738 struct fib_alias *fa;
1739 struct trie *lt;
1740 t_key key = 0;
1741
1742 if (oldtb->tb_data == oldtb->__data)
1743 return oldtb;
1744
1745 local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL);
1746 if (!local_tb)
1747 return NULL;
1748
1749 lt = (struct trie *)local_tb->tb_data;
1750
1751 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
1752 struct key_vector *local_l = NULL, *local_tp;
1753
1754 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
1755 struct fib_alias *new_fa;
1756
1757 if (local_tb->tb_id != fa->tb_id)
1758 continue;
1759
1760 /* clone fa for new local table */
1761 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1762 if (!new_fa)
1763 goto out;
1764
1765 memcpy(new_fa, fa, sizeof(*fa));
1766
1767 /* insert clone into table */
1768 if (!local_l)
1769 local_l = fib_find_node(lt, &local_tp, l->key);
1770
1771 if (fib_insert_alias(lt, local_tp, local_l, new_fa,
1772 NULL, l->key)) {
1773 kmem_cache_free(fn_alias_kmem, new_fa);
1774 goto out;
1775 }
1776 }
1777
1778 /* stop loop if key wrapped back to 0 */
1779 key = l->key + 1;
1780 if (key < l->key)
1781 break;
1782 }
1783
1784 return local_tb;
1785out:
1786 fib_trie_free(local_tb);
1787
1788 return NULL;
1789}
1790
1791/* Caller must hold RTNL */
1792void fib_table_flush_external(struct fib_table *tb)
1793{
1794 struct trie *t = (struct trie *)tb->tb_data;
1795 struct key_vector *pn = t->kv;
1796 unsigned long cindex = 1;
1797 struct hlist_node *tmp;
1798 struct fib_alias *fa;
1799
1800 /* walk trie in reverse order */
1801 for (;;) {
1802 unsigned char slen = 0;
1803 struct key_vector *n;
1804
1805 if (!(cindex--)) {
1806 t_key pkey = pn->key;
1807
1808 /* cannot resize the trie vector */
1809 if (IS_TRIE(pn))
1810 break;
1811
1812 /* update the suffix to address pulled leaves */
1813 if (pn->slen > pn->pos)
1814 update_suffix(pn);
1815
1816 /* resize completed node */
1817 pn = resize(t, pn);
1818 cindex = get_index(pkey, pn);
1819
1820 continue;
1821 }
1822
1823 /* grab the next available node */
1824 n = get_child(pn, cindex);
1825 if (!n)
1826 continue;
1827
1828 if (IS_TNODE(n)) {
1829 /* record pn and cindex for leaf walking */
1830 pn = n;
1831 cindex = 1ul << n->bits;
1832
1833 continue;
1834 }
1835
1836 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1837 /* if alias was cloned to local then we just
1838 * need to remove the local copy from main
1839 */
1840 if (tb->tb_id != fa->tb_id) {
1841 hlist_del_rcu(&fa->fa_list);
1842 alias_free_mem_rcu(fa);
1843 continue;
1844 }
1845
1846 /* record local slen */
1847 slen = fa->fa_slen;
1848 }
1849
1850 /* update leaf slen */
1851 n->slen = slen;
1852
1853 if (hlist_empty(&n->leaf)) {
1854 put_child_root(pn, n->key, NULL);
1855 node_free(n);
1856 }
1857 }
1858}
1859
1860/* Caller must hold RTNL. */
1861int fib_table_flush(struct net *net, struct fib_table *tb, bool flush_all)
1862{
1863 struct trie *t = (struct trie *)tb->tb_data;
1864 struct key_vector *pn = t->kv;
1865 unsigned long cindex = 1;
1866 struct hlist_node *tmp;
1867 struct fib_alias *fa;
1868 int found = 0;
1869
1870 /* walk trie in reverse order */
1871 for (;;) {
1872 unsigned char slen = 0;
1873 struct key_vector *n;
1874
1875 if (!(cindex--)) {
1876 t_key pkey = pn->key;
1877
1878 /* cannot resize the trie vector */
1879 if (IS_TRIE(pn))
1880 break;
1881
1882 /* update the suffix to address pulled leaves */
1883 if (pn->slen > pn->pos)
1884 update_suffix(pn);
1885
1886 /* resize completed node */
1887 pn = resize(t, pn);
1888 cindex = get_index(pkey, pn);
1889
1890 continue;
1891 }
1892
1893 /* grab the next available node */
1894 n = get_child(pn, cindex);
1895 if (!n)
1896 continue;
1897
1898 if (IS_TNODE(n)) {
1899 /* record pn and cindex for leaf walking */
1900 pn = n;
1901 cindex = 1ul << n->bits;
1902
1903 continue;
1904 }
1905
1906 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1907 struct fib_info *fi = fa->fa_info;
1908
1909 if (!fi || tb->tb_id != fa->tb_id ||
1910 (!(fi->fib_flags & RTNH_F_DEAD) &&
1911 !fib_props[fa->fa_type].error)) {
1912 slen = fa->fa_slen;
1913 continue;
1914 }
1915
1916 /* Do not flush error routes if network namespace is
1917 * not being dismantled
1918 */
1919 if (!flush_all && fib_props[fa->fa_type].error) {
1920 slen = fa->fa_slen;
1921 continue;
1922 }
1923
1924 call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL,
1925 n->key,
1926 KEYLENGTH - fa->fa_slen, fa,
1927 NULL);
1928 hlist_del_rcu(&fa->fa_list);
1929 fib_release_info(fa->fa_info);
1930 alias_free_mem_rcu(fa);
1931 found++;
1932 }
1933
1934 /* update leaf slen */
1935 n->slen = slen;
1936
1937 if (hlist_empty(&n->leaf)) {
1938 put_child_root(pn, n->key, NULL);
1939 node_free(n);
1940 }
1941 }
1942
1943 pr_debug("trie_flush found=%d\n", found);
1944 return found;
1945}
1946
1947/* derived from fib_trie_free */
1948static void __fib_info_notify_update(struct net *net, struct fib_table *tb,
1949 struct nl_info *info)
1950{
1951 struct trie *t = (struct trie *)tb->tb_data;
1952 struct key_vector *pn = t->kv;
1953 unsigned long cindex = 1;
1954 struct fib_alias *fa;
1955
1956 for (;;) {
1957 struct key_vector *n;
1958
1959 if (!(cindex--)) {
1960 t_key pkey = pn->key;
1961
1962 if (IS_TRIE(pn))
1963 break;
1964
1965 pn = node_parent(pn);
1966 cindex = get_index(pkey, pn);
1967 continue;
1968 }
1969
1970 /* grab the next available node */
1971 n = get_child(pn, cindex);
1972 if (!n)
1973 continue;
1974
1975 if (IS_TNODE(n)) {
1976 /* record pn and cindex for leaf walking */
1977 pn = n;
1978 cindex = 1ul << n->bits;
1979
1980 continue;
1981 }
1982
1983 hlist_for_each_entry(fa, &n->leaf, fa_list) {
1984 struct fib_info *fi = fa->fa_info;
1985
1986 if (!fi || !fi->nh_updated || fa->tb_id != tb->tb_id)
1987 continue;
1988
1989 rtmsg_fib(RTM_NEWROUTE, htonl(n->key), fa,
1990 KEYLENGTH - fa->fa_slen, tb->tb_id,
1991 info, NLM_F_REPLACE);
1992
1993 /* call_fib_entry_notifiers will be removed when
1994 * in-kernel notifier is implemented and supported
1995 * for nexthop objects
1996 */
1997 call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE,
1998 n->key,
1999 KEYLENGTH - fa->fa_slen, fa,
2000 NULL);
2001 }
2002 }
2003}
2004
2005void fib_info_notify_update(struct net *net, struct nl_info *info)
2006{
2007 unsigned int h;
2008
2009 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2010 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2011 struct fib_table *tb;
2012
2013 hlist_for_each_entry_rcu(tb, head, tb_hlist)
2014 __fib_info_notify_update(net, tb, info);
2015 }
2016}
2017
2018static void fib_leaf_notify(struct net *net, struct key_vector *l,
2019 struct fib_table *tb, struct notifier_block *nb)
2020{
2021 struct fib_alias *fa;
2022
2023 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2024 struct fib_info *fi = fa->fa_info;
2025
2026 if (!fi)
2027 continue;
2028
2029 /* local and main table can share the same trie,
2030 * so don't notify twice for the same entry.
2031 */
2032 if (tb->tb_id != fa->tb_id)
2033 continue;
2034
2035 call_fib_entry_notifier(nb, net, FIB_EVENT_ENTRY_ADD, l->key,
2036 KEYLENGTH - fa->fa_slen, fa);
2037 }
2038}
2039
2040static void fib_table_notify(struct net *net, struct fib_table *tb,
2041 struct notifier_block *nb)
2042{
2043 struct trie *t = (struct trie *)tb->tb_data;
2044 struct key_vector *l, *tp = t->kv;
2045 t_key key = 0;
2046
2047 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
2048 fib_leaf_notify(net, l, tb, nb);
2049
2050 key = l->key + 1;
2051 /* stop in case of wrap around */
2052 if (key < l->key)
2053 break;
2054 }
2055}
2056
2057void fib_notify(struct net *net, struct notifier_block *nb)
2058{
2059 unsigned int h;
2060
2061 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2062 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2063 struct fib_table *tb;
2064
2065 hlist_for_each_entry_rcu(tb, head, tb_hlist)
2066 fib_table_notify(net, tb, nb);
2067 }
2068}
2069
2070static void __trie_free_rcu(struct rcu_head *head)
2071{
2072 struct fib_table *tb = container_of(head, struct fib_table, rcu);
2073#ifdef CONFIG_IP_FIB_TRIE_STATS
2074 struct trie *t = (struct trie *)tb->tb_data;
2075
2076 if (tb->tb_data == tb->__data)
2077 free_percpu(t->stats);
2078#endif /* CONFIG_IP_FIB_TRIE_STATS */
2079 kfree(tb);
2080}
2081
2082void fib_free_table(struct fib_table *tb)
2083{
2084 call_rcu(&tb->rcu, __trie_free_rcu);
2085}
2086
2087static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb,
2088 struct sk_buff *skb, struct netlink_callback *cb,
2089 struct fib_dump_filter *filter)
2090{
2091 unsigned int flags = NLM_F_MULTI;
2092 __be32 xkey = htonl(l->key);
2093 int i, s_i, i_fa, s_fa, err;
2094 struct fib_alias *fa;
2095
2096 if (filter->filter_set ||
2097 !filter->dump_exceptions || !filter->dump_routes)
2098 flags |= NLM_F_DUMP_FILTERED;
2099
2100 s_i = cb->args[4];
2101 s_fa = cb->args[5];
2102 i = 0;
2103
2104 /* rcu_read_lock is hold by caller */
2105 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2106 struct fib_info *fi = fa->fa_info;
2107
2108 if (i < s_i)
2109 goto next;
2110
2111 i_fa = 0;
2112
2113 if (tb->tb_id != fa->tb_id)
2114 goto next;
2115
2116 if (filter->filter_set) {
2117 if (filter->rt_type && fa->fa_type != filter->rt_type)
2118 goto next;
2119
2120 if ((filter->protocol &&
2121 fi->fib_protocol != filter->protocol))
2122 goto next;
2123
2124 if (filter->dev &&
2125 !fib_info_nh_uses_dev(fi, filter->dev))
2126 goto next;
2127 }
2128
2129 if (filter->dump_routes) {
2130 if (!s_fa) {
2131 err = fib_dump_info(skb,
2132 NETLINK_CB(cb->skb).portid,
2133 cb->nlh->nlmsg_seq,
2134 RTM_NEWROUTE,
2135 tb->tb_id, fa->fa_type,
2136 xkey,
2137 KEYLENGTH - fa->fa_slen,
2138 fa->fa_tos, fi, flags);
2139 if (err < 0)
2140 goto stop;
2141 }
2142
2143 i_fa++;
2144 }
2145
2146 if (filter->dump_exceptions) {
2147 err = fib_dump_info_fnhe(skb, cb, tb->tb_id, fi,
2148 &i_fa, s_fa, flags);
2149 if (err < 0)
2150 goto stop;
2151 }
2152
2153next:
2154 i++;
2155 }
2156
2157 cb->args[4] = i;
2158 return skb->len;
2159
2160stop:
2161 cb->args[4] = i;
2162 cb->args[5] = i_fa;
2163 return err;
2164}
2165
2166/* rcu_read_lock needs to be hold by caller from readside */
2167int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
2168 struct netlink_callback *cb, struct fib_dump_filter *filter)
2169{
2170 struct trie *t = (struct trie *)tb->tb_data;
2171 struct key_vector *l, *tp = t->kv;
2172 /* Dump starting at last key.
2173 * Note: 0.0.0.0/0 (ie default) is first key.
2174 */
2175 int count = cb->args[2];
2176 t_key key = cb->args[3];
2177
2178 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
2179 int err;
2180
2181 err = fn_trie_dump_leaf(l, tb, skb, cb, filter);
2182 if (err < 0) {
2183 cb->args[3] = key;
2184 cb->args[2] = count;
2185 return err;
2186 }
2187
2188 ++count;
2189 key = l->key + 1;
2190
2191 memset(&cb->args[4], 0,
2192 sizeof(cb->args) - 4*sizeof(cb->args[0]));
2193
2194 /* stop loop if key wrapped back to 0 */
2195 if (key < l->key)
2196 break;
2197 }
2198
2199 cb->args[3] = key;
2200 cb->args[2] = count;
2201
2202 return skb->len;
2203}
2204
2205void __init fib_trie_init(void)
2206{
2207 fn_alias_kmem = kmem_cache_create("ip_fib_alias",
2208 sizeof(struct fib_alias),
2209 0, SLAB_PANIC, NULL);
2210
2211 trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
2212 LEAF_SIZE,
2213 0, SLAB_PANIC, NULL);
2214}
2215
2216struct fib_table *fib_trie_table(u32 id, struct fib_table *alias)
2217{
2218 struct fib_table *tb;
2219 struct trie *t;
2220 size_t sz = sizeof(*tb);
2221
2222 if (!alias)
2223 sz += sizeof(struct trie);
2224
2225 tb = kzalloc(sz, GFP_KERNEL);
2226 if (!tb)
2227 return NULL;
2228
2229 tb->tb_id = id;
2230 tb->tb_num_default = 0;
2231 tb->tb_data = (alias ? alias->__data : tb->__data);
2232
2233 if (alias)
2234 return tb;
2235
2236 t = (struct trie *) tb->tb_data;
2237 t->kv[0].pos = KEYLENGTH;
2238 t->kv[0].slen = KEYLENGTH;
2239#ifdef CONFIG_IP_FIB_TRIE_STATS
2240 t->stats = alloc_percpu(struct trie_use_stats);
2241 if (!t->stats) {
2242 kfree(tb);
2243 tb = NULL;
2244 }
2245#endif
2246
2247 return tb;
2248}
2249
2250#ifdef CONFIG_PROC_FS
2251/* Depth first Trie walk iterator */
2252struct fib_trie_iter {
2253 struct seq_net_private p;
2254 struct fib_table *tb;
2255 struct key_vector *tnode;
2256 unsigned int index;
2257 unsigned int depth;
2258};
2259
2260static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter)
2261{
2262 unsigned long cindex = iter->index;
2263 struct key_vector *pn = iter->tnode;
2264 t_key pkey;
2265
2266 pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
2267 iter->tnode, iter->index, iter->depth);
2268
2269 while (!IS_TRIE(pn)) {
2270 while (cindex < child_length(pn)) {
2271 struct key_vector *n = get_child_rcu(pn, cindex++);
2272
2273 if (!n)
2274 continue;
2275
2276 if (IS_LEAF(n)) {
2277 iter->tnode = pn;
2278 iter->index = cindex;
2279 } else {
2280 /* push down one level */
2281 iter->tnode = n;
2282 iter->index = 0;
2283 ++iter->depth;
2284 }
2285
2286 return n;
2287 }
2288
2289 /* Current node exhausted, pop back up */
2290 pkey = pn->key;
2291 pn = node_parent_rcu(pn);
2292 cindex = get_index(pkey, pn) + 1;
2293 --iter->depth;
2294 }
2295
2296 /* record root node so further searches know we are done */
2297 iter->tnode = pn;
2298 iter->index = 0;
2299
2300 return NULL;
2301}
2302
2303static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter,
2304 struct trie *t)
2305{
2306 struct key_vector *n, *pn;
2307
2308 if (!t)
2309 return NULL;
2310
2311 pn = t->kv;
2312 n = rcu_dereference(pn->tnode[0]);
2313 if (!n)
2314 return NULL;
2315
2316 if (IS_TNODE(n)) {
2317 iter->tnode = n;
2318 iter->index = 0;
2319 iter->depth = 1;
2320 } else {
2321 iter->tnode = pn;
2322 iter->index = 0;
2323 iter->depth = 0;
2324 }
2325
2326 return n;
2327}
2328
2329static void trie_collect_stats(struct trie *t, struct trie_stat *s)
2330{
2331 struct key_vector *n;
2332 struct fib_trie_iter iter;
2333
2334 memset(s, 0, sizeof(*s));
2335
2336 rcu_read_lock();
2337 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) {
2338 if (IS_LEAF(n)) {
2339 struct fib_alias *fa;
2340
2341 s->leaves++;
2342 s->totdepth += iter.depth;
2343 if (iter.depth > s->maxdepth)
2344 s->maxdepth = iter.depth;
2345
2346 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list)
2347 ++s->prefixes;
2348 } else {
2349 s->tnodes++;
2350 if (n->bits < MAX_STAT_DEPTH)
2351 s->nodesizes[n->bits]++;
2352 s->nullpointers += tn_info(n)->empty_children;
2353 }
2354 }
2355 rcu_read_unlock();
2356}
2357
2358/*
2359 * This outputs /proc/net/fib_triestats
2360 */
2361static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
2362{
2363 unsigned int i, max, pointers, bytes, avdepth;
2364
2365 if (stat->leaves)
2366 avdepth = stat->totdepth*100 / stat->leaves;
2367 else
2368 avdepth = 0;
2369
2370 seq_printf(seq, "\tAver depth: %u.%02d\n",
2371 avdepth / 100, avdepth % 100);
2372 seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth);
2373
2374 seq_printf(seq, "\tLeaves: %u\n", stat->leaves);
2375 bytes = LEAF_SIZE * stat->leaves;
2376
2377 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes);
2378 bytes += sizeof(struct fib_alias) * stat->prefixes;
2379
2380 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);
2381 bytes += TNODE_SIZE(0) * stat->tnodes;
2382
2383 max = MAX_STAT_DEPTH;
2384 while (max > 0 && stat->nodesizes[max-1] == 0)
2385 max--;
2386
2387 pointers = 0;
2388 for (i = 1; i < max; i++)
2389 if (stat->nodesizes[i] != 0) {
2390 seq_printf(seq, " %u: %u", i, stat->nodesizes[i]);
2391 pointers += (1<<i) * stat->nodesizes[i];
2392 }
2393 seq_putc(seq, '\n');
2394 seq_printf(seq, "\tPointers: %u\n", pointers);
2395
2396 bytes += sizeof(struct key_vector *) * pointers;
2397 seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers);
2398 seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024);
2399}
2400
2401#ifdef CONFIG_IP_FIB_TRIE_STATS
2402static void trie_show_usage(struct seq_file *seq,
2403 const struct trie_use_stats __percpu *stats)
2404{
2405 struct trie_use_stats s = { 0 };
2406 int cpu;
2407
2408 /* loop through all of the CPUs and gather up the stats */
2409 for_each_possible_cpu(cpu) {
2410 const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu);
2411
2412 s.gets += pcpu->gets;
2413 s.backtrack += pcpu->backtrack;
2414 s.semantic_match_passed += pcpu->semantic_match_passed;
2415 s.semantic_match_miss += pcpu->semantic_match_miss;
2416 s.null_node_hit += pcpu->null_node_hit;
2417 s.resize_node_skipped += pcpu->resize_node_skipped;
2418 }
2419
2420 seq_printf(seq, "\nCounters:\n---------\n");
2421 seq_printf(seq, "gets = %u\n", s.gets);
2422 seq_printf(seq, "backtracks = %u\n", s.backtrack);
2423 seq_printf(seq, "semantic match passed = %u\n",
2424 s.semantic_match_passed);
2425 seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss);
2426 seq_printf(seq, "null node hit= %u\n", s.null_node_hit);
2427 seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped);
2428}
2429#endif /* CONFIG_IP_FIB_TRIE_STATS */
2430
2431static void fib_table_print(struct seq_file *seq, struct fib_table *tb)
2432{
2433 if (tb->tb_id == RT_TABLE_LOCAL)
2434 seq_puts(seq, "Local:\n");
2435 else if (tb->tb_id == RT_TABLE_MAIN)
2436 seq_puts(seq, "Main:\n");
2437 else
2438 seq_printf(seq, "Id %d:\n", tb->tb_id);
2439}
2440
2441
2442static int fib_triestat_seq_show(struct seq_file *seq, void *v)
2443{
2444 struct net *net = (struct net *)seq->private;
2445 unsigned int h;
2446
2447 seq_printf(seq,
2448 "Basic info: size of leaf:"
2449 " %zd bytes, size of tnode: %zd bytes.\n",
2450 LEAF_SIZE, TNODE_SIZE(0));
2451
2452 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2453 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2454 struct fib_table *tb;
2455
2456 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2457 struct trie *t = (struct trie *) tb->tb_data;
2458 struct trie_stat stat;
2459
2460 if (!t)
2461 continue;
2462
2463 fib_table_print(seq, tb);
2464
2465 trie_collect_stats(t, &stat);
2466 trie_show_stats(seq, &stat);
2467#ifdef CONFIG_IP_FIB_TRIE_STATS
2468 trie_show_usage(seq, t->stats);
2469#endif
2470 }
2471 }
2472
2473 return 0;
2474}
2475
2476static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos)
2477{
2478 struct fib_trie_iter *iter = seq->private;
2479 struct net *net = seq_file_net(seq);
2480 loff_t idx = 0;
2481 unsigned int h;
2482
2483 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2484 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2485 struct fib_table *tb;
2486
2487 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2488 struct key_vector *n;
2489
2490 for (n = fib_trie_get_first(iter,
2491 (struct trie *) tb->tb_data);
2492 n; n = fib_trie_get_next(iter))
2493 if (pos == idx++) {
2494 iter->tb = tb;
2495 return n;
2496 }
2497 }
2498 }
2499
2500 return NULL;
2501}
2502
2503static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
2504 __acquires(RCU)
2505{
2506 rcu_read_lock();
2507 return fib_trie_get_idx(seq, *pos);
2508}
2509
2510static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2511{
2512 struct fib_trie_iter *iter = seq->private;
2513 struct net *net = seq_file_net(seq);
2514 struct fib_table *tb = iter->tb;
2515 struct hlist_node *tb_node;
2516 unsigned int h;
2517 struct key_vector *n;
2518
2519 ++*pos;
2520 /* next node in same table */
2521 n = fib_trie_get_next(iter);
2522 if (n)
2523 return n;
2524
2525 /* walk rest of this hash chain */
2526 h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);
2527 while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) {
2528 tb = hlist_entry(tb_node, struct fib_table, tb_hlist);
2529 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2530 if (n)
2531 goto found;
2532 }
2533
2534 /* new hash chain */
2535 while (++h < FIB_TABLE_HASHSZ) {
2536 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2537 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2538 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2539 if (n)
2540 goto found;
2541 }
2542 }
2543 return NULL;
2544
2545found:
2546 iter->tb = tb;
2547 return n;
2548}
2549
2550static void fib_trie_seq_stop(struct seq_file *seq, void *v)
2551 __releases(RCU)
2552{
2553 rcu_read_unlock();
2554}
2555
2556static void seq_indent(struct seq_file *seq, int n)
2557{
2558 while (n-- > 0)
2559 seq_puts(seq, " ");
2560}
2561
2562static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
2563{
2564 switch (s) {
2565 case RT_SCOPE_UNIVERSE: return "universe";
2566 case RT_SCOPE_SITE: return "site";
2567 case RT_SCOPE_LINK: return "link";
2568 case RT_SCOPE_HOST: return "host";
2569 case RT_SCOPE_NOWHERE: return "nowhere";
2570 default:
2571 snprintf(buf, len, "scope=%d", s);
2572 return buf;
2573 }
2574}
2575
2576static const char *const rtn_type_names[__RTN_MAX] = {
2577 [RTN_UNSPEC] = "UNSPEC",
2578 [RTN_UNICAST] = "UNICAST",
2579 [RTN_LOCAL] = "LOCAL",
2580 [RTN_BROADCAST] = "BROADCAST",
2581 [RTN_ANYCAST] = "ANYCAST",
2582 [RTN_MULTICAST] = "MULTICAST",
2583 [RTN_BLACKHOLE] = "BLACKHOLE",
2584 [RTN_UNREACHABLE] = "UNREACHABLE",
2585 [RTN_PROHIBIT] = "PROHIBIT",
2586 [RTN_THROW] = "THROW",
2587 [RTN_NAT] = "NAT",
2588 [RTN_XRESOLVE] = "XRESOLVE",
2589};
2590
2591static inline const char *rtn_type(char *buf, size_t len, unsigned int t)
2592{
2593 if (t < __RTN_MAX && rtn_type_names[t])
2594 return rtn_type_names[t];
2595 snprintf(buf, len, "type %u", t);
2596 return buf;
2597}
2598
2599/* Pretty print the trie */
2600static int fib_trie_seq_show(struct seq_file *seq, void *v)
2601{
2602 const struct fib_trie_iter *iter = seq->private;
2603 struct key_vector *n = v;
2604
2605 if (IS_TRIE(node_parent_rcu(n)))
2606 fib_table_print(seq, iter->tb);
2607
2608 if (IS_TNODE(n)) {
2609 __be32 prf = htonl(n->key);
2610
2611 seq_indent(seq, iter->depth-1);
2612 seq_printf(seq, " +-- %pI4/%zu %u %u %u\n",
2613 &prf, KEYLENGTH - n->pos - n->bits, n->bits,
2614 tn_info(n)->full_children,
2615 tn_info(n)->empty_children);
2616 } else {
2617 __be32 val = htonl(n->key);
2618 struct fib_alias *fa;
2619
2620 seq_indent(seq, iter->depth);
2621 seq_printf(seq, " |-- %pI4\n", &val);
2622
2623 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
2624 char buf1[32], buf2[32];
2625
2626 seq_indent(seq, iter->depth + 1);
2627 seq_printf(seq, " /%zu %s %s",
2628 KEYLENGTH - fa->fa_slen,
2629 rtn_scope(buf1, sizeof(buf1),
2630 fa->fa_info->fib_scope),
2631 rtn_type(buf2, sizeof(buf2),
2632 fa->fa_type));
2633 if (fa->fa_tos)
2634 seq_printf(seq, " tos=%d", fa->fa_tos);
2635 seq_putc(seq, '\n');
2636 }
2637 }
2638
2639 return 0;
2640}
2641
2642static const struct seq_operations fib_trie_seq_ops = {
2643 .start = fib_trie_seq_start,
2644 .next = fib_trie_seq_next,
2645 .stop = fib_trie_seq_stop,
2646 .show = fib_trie_seq_show,
2647};
2648
2649struct fib_route_iter {
2650 struct seq_net_private p;
2651 struct fib_table *main_tb;
2652 struct key_vector *tnode;
2653 loff_t pos;
2654 t_key key;
2655};
2656
2657static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter,
2658 loff_t pos)
2659{
2660 struct key_vector *l, **tp = &iter->tnode;
2661 t_key key;
2662
2663 /* use cached location of previously found key */
2664 if (iter->pos > 0 && pos >= iter->pos) {
2665 key = iter->key;
2666 } else {
2667 iter->pos = 1;
2668 key = 0;
2669 }
2670
2671 pos -= iter->pos;
2672
2673 while ((l = leaf_walk_rcu(tp, key)) && (pos-- > 0)) {
2674 key = l->key + 1;
2675 iter->pos++;
2676 l = NULL;
2677
2678 /* handle unlikely case of a key wrap */
2679 if (!key)
2680 break;
2681 }
2682
2683 if (l)
2684 iter->key = l->key; /* remember it */
2685 else
2686 iter->pos = 0; /* forget it */
2687
2688 return l;
2689}
2690
2691static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos)
2692 __acquires(RCU)
2693{
2694 struct fib_route_iter *iter = seq->private;
2695 struct fib_table *tb;
2696 struct trie *t;
2697
2698 rcu_read_lock();
2699
2700 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
2701 if (!tb)
2702 return NULL;
2703
2704 iter->main_tb = tb;
2705 t = (struct trie *)tb->tb_data;
2706 iter->tnode = t->kv;
2707
2708 if (*pos != 0)
2709 return fib_route_get_idx(iter, *pos);
2710
2711 iter->pos = 0;
2712 iter->key = KEY_MAX;
2713
2714 return SEQ_START_TOKEN;
2715}
2716
2717static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2718{
2719 struct fib_route_iter *iter = seq->private;
2720 struct key_vector *l = NULL;
2721 t_key key = iter->key + 1;
2722
2723 ++*pos;
2724
2725 /* only allow key of 0 for start of sequence */
2726 if ((v == SEQ_START_TOKEN) || key)
2727 l = leaf_walk_rcu(&iter->tnode, key);
2728
2729 if (l) {
2730 iter->key = l->key;
2731 iter->pos++;
2732 } else {
2733 iter->pos = 0;
2734 }
2735
2736 return l;
2737}
2738
2739static void fib_route_seq_stop(struct seq_file *seq, void *v)
2740 __releases(RCU)
2741{
2742 rcu_read_unlock();
2743}
2744
2745static unsigned int fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
2746{
2747 unsigned int flags = 0;
2748
2749 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT)
2750 flags = RTF_REJECT;
2751 if (fi) {
2752 const struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
2753
2754 if (nhc->nhc_gw.ipv4)
2755 flags |= RTF_GATEWAY;
2756 }
2757 if (mask == htonl(0xFFFFFFFF))
2758 flags |= RTF_HOST;
2759 flags |= RTF_UP;
2760 return flags;
2761}
2762
2763/*
2764 * This outputs /proc/net/route.
2765 * The format of the file is not supposed to be changed
2766 * and needs to be same as fib_hash output to avoid breaking
2767 * legacy utilities
2768 */
2769static int fib_route_seq_show(struct seq_file *seq, void *v)
2770{
2771 struct fib_route_iter *iter = seq->private;
2772 struct fib_table *tb = iter->main_tb;
2773 struct fib_alias *fa;
2774 struct key_vector *l = v;
2775 __be32 prefix;
2776
2777 if (v == SEQ_START_TOKEN) {
2778 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
2779 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
2780 "\tWindow\tIRTT");
2781 return 0;
2782 }
2783
2784 prefix = htonl(l->key);
2785
2786 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2787 struct fib_info *fi = fa->fa_info;
2788 __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen);
2789 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);
2790
2791 if ((fa->fa_type == RTN_BROADCAST) ||
2792 (fa->fa_type == RTN_MULTICAST))
2793 continue;
2794
2795 if (fa->tb_id != tb->tb_id)
2796 continue;
2797
2798 seq_setwidth(seq, 127);
2799
2800 if (fi) {
2801 struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
2802 __be32 gw = 0;
2803
2804 if (nhc->nhc_gw_family == AF_INET)
2805 gw = nhc->nhc_gw.ipv4;
2806
2807 seq_printf(seq,
2808 "%s\t%08X\t%08X\t%04X\t%d\t%u\t"
2809 "%d\t%08X\t%d\t%u\t%u",
2810 nhc->nhc_dev ? nhc->nhc_dev->name : "*",
2811 prefix, gw, flags, 0, 0,
2812 fi->fib_priority,
2813 mask,
2814 (fi->fib_advmss ?
2815 fi->fib_advmss + 40 : 0),
2816 fi->fib_window,
2817 fi->fib_rtt >> 3);
2818 } else {
2819 seq_printf(seq,
2820 "*\t%08X\t%08X\t%04X\t%d\t%u\t"
2821 "%d\t%08X\t%d\t%u\t%u",
2822 prefix, 0, flags, 0, 0, 0,
2823 mask, 0, 0, 0);
2824 }
2825 seq_pad(seq, '\n');
2826 }
2827
2828 return 0;
2829}
2830
2831static const struct seq_operations fib_route_seq_ops = {
2832 .start = fib_route_seq_start,
2833 .next = fib_route_seq_next,
2834 .stop = fib_route_seq_stop,
2835 .show = fib_route_seq_show,
2836};
2837
2838int __net_init fib_proc_init(struct net *net)
2839{
2840 if (!proc_create_net("fib_trie", 0444, net->proc_net, &fib_trie_seq_ops,
2841 sizeof(struct fib_trie_iter)))
2842 goto out1;
2843
2844 if (!proc_create_net_single("fib_triestat", 0444, net->proc_net,
2845 fib_triestat_seq_show, NULL))
2846 goto out2;
2847
2848 if (!proc_create_net("route", 0444, net->proc_net, &fib_route_seq_ops,
2849 sizeof(struct fib_route_iter)))
2850 goto out3;
2851
2852 return 0;
2853
2854out3:
2855 remove_proc_entry("fib_triestat", net->proc_net);
2856out2:
2857 remove_proc_entry("fib_trie", net->proc_net);
2858out1:
2859 return -ENOMEM;
2860}
2861
2862void __net_exit fib_proc_exit(struct net *net)
2863{
2864 remove_proc_entry("fib_trie", net->proc_net);
2865 remove_proc_entry("fib_triestat", net->proc_net);
2866 remove_proc_entry("route", net->proc_net);
2867}
2868
2869#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 */