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
92 typedef 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
98 struct 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
111 struct 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
124 struct 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
134 struct 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
144 struct 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
151 static struct key_vector *resize(struct trie *t, struct key_vector *tn);
152 static 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 */
159 static const int sync_pages = 128;
160
161 static struct kmem_cache *fn_alias_kmem __read_mostly;
162 static struct kmem_cache *trie_leaf_kmem __read_mostly;
163
164 static 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 */
178 static 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 */
189 static 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
196 static 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 (tp->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 -1) - "u" - are completely unknown
262 * at this point.
263 */
264
265 static const int halve_threshold = 25;
266 static const int inflate_threshold = 50;
267 static const int halve_threshold_root = 15;
268 static const int inflate_threshold_root = 30;
269
270 static 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
276 static 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
286 static 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
298 static 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
315 static inline void empty_child_inc(struct key_vector *n)
316 {
317 ++tn_info(n)->empty_children ? : ++tn_info(n)->full_children;
318 }
319
320 static inline void empty_child_dec(struct key_vector *n)
321 {
322 tn_info(n)->empty_children-- ? : tn_info(n)->full_children--;
323 }
324
325 static 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
348 static 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 */
381 static 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 */
389 static 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
418 static 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
440 static 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
449 static inline void tnode_free_init(struct key_vector *tn)
450 {
451 tn_info(tn)->rcu.next = NULL;
452 }
453
454 static 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
461 static 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
479 static 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
508 static 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 "" 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);
597 nomem:
598 /* all pointers should be clean so we are done */
599 tnode_free(tn);
600 notnode:
601 return NULL;
602 }
603
604 static 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);
652 nomem:
653 /* all pointers should be clean so we are done */
654 tnode_free(tn);
655 notnode:
656 return NULL;
657 }
658
659 static 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
680 static unsigned char update_suffix(struct key_vector *tn)
681 {
682 unsigned char slen = tn->pos;
683 unsigned long stride, i;
684 unsigned char slen_max;
685
686 /* only vector 0 can have a suffix length greater than or equal to
687 * tn->pos + tn->bits, the second highest node will have a suffix
688 * length at most of tn->pos + tn->bits - 1
689 */
690 slen_max = min_t(unsigned char, tn->pos + tn->bits - 1, tn->slen);
691
692 /* search though the list of children looking for nodes that might
693 * have a suffix greater than the one we currently have. This is
694 * why we start with a stride of 2 since a stride of 1 would
695 * represent the nodes with suffix length equal to tn->pos
696 */
697 for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) {
698 struct key_vector *n = get_child(tn, i);
699
700 if (!n || (n->slen <= slen))
701 continue;
702
703 /* update stride and slen based on new value */
704 stride <<= (n->slen - slen);
705 slen = n->slen;
706 i &= ~(stride - 1);
707
708 /* stop searching if we have hit the maximum possible value */
709 if (slen >= slen_max)
710 break;
711 }
712
713 tn->slen = slen;
714
715 return slen;
716 }
717
718 /* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
719 * the Helsinki University of Technology and Matti Tikkanen of Nokia
720 * Telecommunications, page 6:
721 * "A node is doubled if the ratio of non-empty children to all
722 * children in the *doubled* node is at least 'high'."
723 *
724 * 'high' in this instance is the variable 'inflate_threshold'. It
725 * is expressed as a percentage, so we multiply it with
726 * child_length() and instead of multiplying by 2 (since the
727 * child array will be doubled by inflate()) and multiplying
728 * the left-hand side by 100 (to handle the percentage thing) we
729 * multiply the left-hand side by 50.
730 *
731 * The left-hand side may look a bit weird: child_length(tn)
732 * - tn->empty_children is of course the number of non-null children
733 * in the current node. tn->full_children is the number of "full"
734 * children, that is non-null tnodes with a skip value of 0.
735 * All of those will be doubled in the resulting inflated tnode, so
736 * we just count them one extra time here.
737 *
738 * A clearer way to write this would be:
739 *
740 * to_be_doubled = tn->full_children;
741 * not_to_be_doubled = child_length(tn) - tn->empty_children -
742 * tn->full_children;
743 *
744 * new_child_length = child_length(tn) * 2;
745 *
746 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
747 * new_child_length;
748 * if (new_fill_factor >= inflate_threshold)
749 *
750 * ...and so on, tho it would mess up the while () loop.
751 *
752 * anyway,
753 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
754 * inflate_threshold
755 *
756 * avoid a division:
757 * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
758 * inflate_threshold * new_child_length
759 *
760 * expand not_to_be_doubled and to_be_doubled, and shorten:
761 * 100 * (child_length(tn) - tn->empty_children +
762 * tn->full_children) >= inflate_threshold * new_child_length
763 *
764 * expand new_child_length:
765 * 100 * (child_length(tn) - tn->empty_children +
766 * tn->full_children) >=
767 * inflate_threshold * child_length(tn) * 2
768 *
769 * shorten again:
770 * 50 * (tn->full_children + child_length(tn) -
771 * tn->empty_children) >= inflate_threshold *
772 * child_length(tn)
773 *
774 */
775 static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn)
776 {
777 unsigned long used = child_length(tn);
778 unsigned long threshold = used;
779
780 /* Keep root node larger */
781 threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold;
782 used -= tn_info(tn)->empty_children;
783 used += tn_info(tn)->full_children;
784
785 /* if bits == KEYLENGTH then pos = 0, and will fail below */
786
787 return (used > 1) && tn->pos && ((50 * used) >= threshold);
788 }
789
790 static inline bool should_halve(struct key_vector *tp, struct key_vector *tn)
791 {
792 unsigned long used = child_length(tn);
793 unsigned long threshold = used;
794
795 /* Keep root node larger */
796 threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold;
797 used -= tn_info(tn)->empty_children;
798
799 /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */
800
801 return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold);
802 }
803
804 static inline bool should_collapse(struct key_vector *tn)
805 {
806 unsigned long used = child_length(tn);
807
808 used -= tn_info(tn)->empty_children;
809
810 /* account for bits == KEYLENGTH case */
811 if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children)
812 used -= KEY_MAX;
813
814 /* One child or none, time to drop us from the trie */
815 return used < 2;
816 }
817
818 #define MAX_WORK 10
819 static struct key_vector *resize(struct trie *t, struct key_vector *tn)
820 {
821 #ifdef CONFIG_IP_FIB_TRIE_STATS
822 struct trie_use_stats __percpu *stats = t->stats;
823 #endif
824 struct key_vector *tp = node_parent(tn);
825 unsigned long cindex = get_index(tn->key, tp);
826 int max_work = MAX_WORK;
827
828 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
829 tn, inflate_threshold, halve_threshold);
830
831 /* track the tnode via the pointer from the parent instead of
832 * doing it ourselves. This way we can let RCU fully do its
833 * thing without us interfering
834 */
835 BUG_ON(tn != get_child(tp, cindex));
836
837 /* Double as long as the resulting node has a number of
838 * nonempty nodes that are above the threshold.
839 */
840 while (should_inflate(tp, tn) && max_work) {
841 tp = inflate(t, tn);
842 if (!tp) {
843 #ifdef CONFIG_IP_FIB_TRIE_STATS
844 this_cpu_inc(stats->resize_node_skipped);
845 #endif
846 break;
847 }
848
849 max_work--;
850 tn = get_child(tp, cindex);
851 }
852
853 /* update parent in case inflate failed */
854 tp = node_parent(tn);
855
856 /* Return if at least one inflate is run */
857 if (max_work != MAX_WORK)
858 return tp;
859
860 /* Halve as long as the number of empty children in this
861 * node is above threshold.
862 */
863 while (should_halve(tp, tn) && max_work) {
864 tp = halve(t, tn);
865 if (!tp) {
866 #ifdef CONFIG_IP_FIB_TRIE_STATS
867 this_cpu_inc(stats->resize_node_skipped);
868 #endif
869 break;
870 }
871
872 max_work--;
873 tn = get_child(tp, cindex);
874 }
875
876 /* Only one child remains */
877 if (should_collapse(tn))
878 return collapse(t, tn);
879
880 /* update parent in case halve failed */
881 return node_parent(tn);
882 }
883
884 static void node_pull_suffix(struct key_vector *tn, unsigned char slen)
885 {
886 unsigned char node_slen = tn->slen;
887
888 while ((node_slen > tn->pos) && (node_slen > slen)) {
889 slen = update_suffix(tn);
890 if (node_slen == slen)
891 break;
892
893 tn = node_parent(tn);
894 node_slen = tn->slen;
895 }
896 }
897
898 static void node_push_suffix(struct key_vector *tn, unsigned char slen)
899 {
900 while (tn->slen < slen) {
901 tn->slen = slen;
902 tn = node_parent(tn);
903 }
904 }
905
906 /* rcu_read_lock needs to be hold by caller from readside */
907 static struct key_vector *fib_find_node(struct trie *t,
908 struct key_vector **tp, u32 key)
909 {
910 struct key_vector *pn, *n = t->kv;
911 unsigned long index = 0;
912
913 do {
914 pn = n;
915 n = get_child_rcu(n, index);
916
917 if (!n)
918 break;
919
920 index = get_cindex(key, n);
921
922 /* This bit of code is a bit tricky but it combines multiple
923 * checks into a single check. The prefix consists of the
924 * prefix plus zeros for the bits in the cindex. The index
925 * is the difference between the key and this value. From
926 * this we can actually derive several pieces of data.
927 * if (index >= (1ul << bits))
928 * we have a mismatch in skip bits and failed
929 * else
930 * we know the value is cindex
931 *
932 * This check is safe even if bits == KEYLENGTH due to the
933 * fact that we can only allocate a node with 32 bits if a
934 * long is greater than 32 bits.
935 */
936 if (index >= (1ul << n->bits)) {
937 n = NULL;
938 break;
939 }
940
941 /* keep searching until we find a perfect match leaf or NULL */
942 } while (IS_TNODE(n));
943
944 *tp = pn;
945
946 return n;
947 }
948
949 /* Return the first fib alias matching TOS with
950 * priority less than or equal to PRIO.
951 */
952 static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen,
953 u8 tos, u32 prio, u32 tb_id)
954 {
955 struct fib_alias *fa;
956
957 if (!fah)
958 return NULL;
959
960 hlist_for_each_entry(fa, fah, fa_list) {
961 if (fa->fa_slen < slen)
962 continue;
963 if (fa->fa_slen != slen)
964 break;
965 if (fa->tb_id > tb_id)
966 continue;
967 if (fa->tb_id != tb_id)
968 break;
969 if (fa->fa_tos > tos)
970 continue;
971 if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos)
972 return fa;
973 }
974
975 return NULL;
976 }
977
978 static void trie_rebalance(struct trie *t, struct key_vector *tn)
979 {
980 while (!IS_TRIE(tn))
981 tn = resize(t, tn);
982 }
983
984 static int fib_insert_node(struct trie *t, struct key_vector *tp,
985 struct fib_alias *new, t_key key)
986 {
987 struct key_vector *n, *l;
988
989 l = leaf_new(key, new);
990 if (!l)
991 goto noleaf;
992
993 /* retrieve child from parent node */
994 n = get_child(tp, get_index(key, tp));
995
996 /* Case 2: n is a LEAF or a TNODE and the key doesn't match.
997 *
998 * Add a new tnode here
999 * first tnode need some special handling
1000 * leaves us in position for handling as case 3
1001 */
1002 if (n) {
1003 struct key_vector *tn;
1004
1005 tn = tnode_new(key, __fls(key ^ n->key), 1);
1006 if (!tn)
1007 goto notnode;
1008
1009 /* initialize routes out of node */
1010 NODE_INIT_PARENT(tn, tp);
1011 put_child(tn, get_index(key, tn) ^ 1, n);
1012
1013 /* start adding routes into the node */
1014 put_child_root(tp, key, tn);
1015 node_set_parent(n, tn);
1016
1017 /* parent now has a NULL spot where the leaf can go */
1018 tp = tn;
1019 }
1020
1021 /* Case 3: n is NULL, and will just insert a new leaf */
1022 node_push_suffix(tp, new->fa_slen);
1023 NODE_INIT_PARENT(l, tp);
1024 put_child_root(tp, key, l);
1025 trie_rebalance(t, tp);
1026
1027 return 0;
1028 notnode:
1029 node_free(l);
1030 noleaf:
1031 return -ENOMEM;
1032 }
1033
1034 static int fib_insert_alias(struct trie *t, struct key_vector *tp,
1035 struct key_vector *l, struct fib_alias *new,
1036 struct fib_alias *fa, t_key key)
1037 {
1038 if (!l)
1039 return fib_insert_node(t, tp, new, key);
1040
1041 if (fa) {
1042 hlist_add_before_rcu(&new->fa_list, &fa->fa_list);
1043 } else {
1044 struct fib_alias *last;
1045
1046 hlist_for_each_entry(last, &l->leaf, fa_list) {
1047 if (new->fa_slen < last->fa_slen)
1048 break;
1049 if ((new->fa_slen == last->fa_slen) &&
1050 (new->tb_id > last->tb_id))
1051 break;
1052 fa = last;
1053 }
1054
1055 if (fa)
1056 hlist_add_behind_rcu(&new->fa_list, &fa->fa_list);
1057 else
1058 hlist_add_head_rcu(&new->fa_list, &l->leaf);
1059 }
1060
1061 /* if we added to the tail node then we need to update slen */
1062 if (l->slen < new->fa_slen) {
1063 l->slen = new->fa_slen;
1064 node_push_suffix(tp, new->fa_slen);
1065 }
1066
1067 return 0;
1068 }
1069
1070 /* Caller must hold RTNL. */
1071 int fib_table_insert(struct fib_table *tb, struct fib_config *cfg)
1072 {
1073 struct trie *t = (struct trie *)tb->tb_data;
1074 struct fib_alias *fa, *new_fa;
1075 struct key_vector *l, *tp;
1076 unsigned int nlflags = 0;
1077 struct fib_info *fi;
1078 u8 plen = cfg->fc_dst_len;
1079 u8 slen = KEYLENGTH - plen;
1080 u8 tos = cfg->fc_tos;
1081 u32 key;
1082 int err;
1083
1084 if (plen > KEYLENGTH)
1085 return -EINVAL;
1086
1087 key = ntohl(cfg->fc_dst);
1088
1089 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
1090
1091 if ((plen < KEYLENGTH) && (key << plen))
1092 return -EINVAL;
1093
1094 fi = fib_create_info(cfg);
1095 if (IS_ERR(fi)) {
1096 err = PTR_ERR(fi);
1097 goto err;
1098 }
1099
1100 l = fib_find_node(t, &tp, key);
1101 fa = l ? fib_find_alias(&l->leaf, slen, tos, fi->fib_priority,
1102 tb->tb_id) : NULL;
1103
1104 /* Now fa, if non-NULL, points to the first fib alias
1105 * with the same keys [prefix,tos,priority], if such key already
1106 * exists or to the node before which we will insert new one.
1107 *
1108 * If fa is NULL, we will need to allocate a new one and
1109 * insert to the tail of the section matching the suffix length
1110 * of the new alias.
1111 */
1112
1113 if (fa && fa->fa_tos == tos &&
1114 fa->fa_info->fib_priority == fi->fib_priority) {
1115 struct fib_alias *fa_first, *fa_match;
1116
1117 err = -EEXIST;
1118 if (cfg->fc_nlflags & NLM_F_EXCL)
1119 goto out;
1120
1121 /* We have 2 goals:
1122 * 1. Find exact match for type, scope, fib_info to avoid
1123 * duplicate routes
1124 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
1125 */
1126 fa_match = NULL;
1127 fa_first = fa;
1128 hlist_for_each_entry_from(fa, fa_list) {
1129 if ((fa->fa_slen != slen) ||
1130 (fa->tb_id != tb->tb_id) ||
1131 (fa->fa_tos != tos))
1132 break;
1133 if (fa->fa_info->fib_priority != fi->fib_priority)
1134 break;
1135 if (fa->fa_type == cfg->fc_type &&
1136 fa->fa_info == fi) {
1137 fa_match = fa;
1138 break;
1139 }
1140 }
1141
1142 if (cfg->fc_nlflags & NLM_F_REPLACE) {
1143 struct fib_info *fi_drop;
1144 u8 state;
1145
1146 fa = fa_first;
1147 if (fa_match) {
1148 if (fa == fa_match)
1149 err = 0;
1150 goto out;
1151 }
1152 err = -ENOBUFS;
1153 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1154 if (!new_fa)
1155 goto out;
1156
1157 fi_drop = fa->fa_info;
1158 new_fa->fa_tos = fa->fa_tos;
1159 new_fa->fa_info = fi;
1160 new_fa->fa_type = cfg->fc_type;
1161 state = fa->fa_state;
1162 new_fa->fa_state = state & ~FA_S_ACCESSED;
1163 new_fa->fa_slen = fa->fa_slen;
1164 new_fa->tb_id = tb->tb_id;
1165 new_fa->fa_default = -1;
1166
1167 err = switchdev_fib_ipv4_add(key, plen, fi,
1168 new_fa->fa_tos,
1169 cfg->fc_type,
1170 cfg->fc_nlflags,
1171 tb->tb_id);
1172 if (err) {
1173 switchdev_fib_ipv4_abort(fi);
1174 kmem_cache_free(fn_alias_kmem, new_fa);
1175 goto out;
1176 }
1177
1178 hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list);
1179
1180 alias_free_mem_rcu(fa);
1181
1182 fib_release_info(fi_drop);
1183 if (state & FA_S_ACCESSED)
1184 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1185 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
1186 tb->tb_id, &cfg->fc_nlinfo, NLM_F_REPLACE);
1187
1188 goto succeeded;
1189 }
1190 /* Error if we find a perfect match which
1191 * uses the same scope, type, and nexthop
1192 * information.
1193 */
1194 if (fa_match)
1195 goto out;
1196
1197 if (cfg->fc_nlflags & NLM_F_APPEND)
1198 nlflags = NLM_F_APPEND;
1199 else
1200 fa = fa_first;
1201 }
1202 err = -ENOENT;
1203 if (!(cfg->fc_nlflags & NLM_F_CREATE))
1204 goto out;
1205
1206 err = -ENOBUFS;
1207 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1208 if (!new_fa)
1209 goto out;
1210
1211 new_fa->fa_info = fi;
1212 new_fa->fa_tos = tos;
1213 new_fa->fa_type = cfg->fc_type;
1214 new_fa->fa_state = 0;
1215 new_fa->fa_slen = slen;
1216 new_fa->tb_id = tb->tb_id;
1217 new_fa->fa_default = -1;
1218
1219 /* (Optionally) offload fib entry to switch hardware. */
1220 err = switchdev_fib_ipv4_add(key, plen, fi, tos, cfg->fc_type,
1221 cfg->fc_nlflags, tb->tb_id);
1222 if (err) {
1223 switchdev_fib_ipv4_abort(fi);
1224 goto out_free_new_fa;
1225 }
1226
1227 /* Insert new entry to the list. */
1228 err = fib_insert_alias(t, tp, l, new_fa, fa, key);
1229 if (err)
1230 goto out_sw_fib_del;
1231
1232 if (!plen)
1233 tb->tb_num_default++;
1234
1235 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1236 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id,
1237 &cfg->fc_nlinfo, nlflags);
1238 succeeded:
1239 return 0;
1240
1241 out_sw_fib_del:
1242 switchdev_fib_ipv4_del(key, plen, fi, tos, cfg->fc_type, tb->tb_id);
1243 out_free_new_fa:
1244 kmem_cache_free(fn_alias_kmem, new_fa);
1245 out:
1246 fib_release_info(fi);
1247 err:
1248 return err;
1249 }
1250
1251 static inline t_key prefix_mismatch(t_key key, struct key_vector *n)
1252 {
1253 t_key prefix = n->key;
1254
1255 return (key ^ prefix) & (prefix | -prefix);
1256 }
1257
1258 /* should be called with rcu_read_lock */
1259 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
1260 struct fib_result *res, int fib_flags)
1261 {
1262 struct trie *t = (struct trie *) tb->tb_data;
1263 #ifdef CONFIG_IP_FIB_TRIE_STATS
1264 struct trie_use_stats __percpu *stats = t->stats;
1265 #endif
1266 const t_key key = ntohl(flp->daddr);
1267 struct key_vector *n, *pn;
1268 struct fib_alias *fa;
1269 unsigned long index;
1270 t_key cindex;
1271
1272 trace_fib_table_lookup(tb->tb_id, flp);
1273
1274 pn = t->kv;
1275 cindex = 0;
1276
1277 n = get_child_rcu(pn, cindex);
1278 if (!n)
1279 return -EAGAIN;
1280
1281 #ifdef CONFIG_IP_FIB_TRIE_STATS
1282 this_cpu_inc(stats->gets);
1283 #endif
1284
1285 /* Step 1: Travel to the longest prefix match in the trie */
1286 for (;;) {
1287 index = get_cindex(key, n);
1288
1289 /* This bit of code is a bit tricky but it combines multiple
1290 * checks into a single check. The prefix consists of the
1291 * prefix plus zeros for the "bits" in the prefix. The index
1292 * is the difference between the key and this value. From
1293 * this we can actually derive several pieces of data.
1294 * if (index >= (1ul << bits))
1295 * we have a mismatch in skip bits and failed
1296 * else
1297 * we know the value is cindex
1298 *
1299 * This check is safe even if bits == KEYLENGTH due to the
1300 * fact that we can only allocate a node with 32 bits if a
1301 * long is greater than 32 bits.
1302 */
1303 if (index >= (1ul << n->bits))
1304 break;
1305
1306 /* we have found a leaf. Prefixes have already been compared */
1307 if (IS_LEAF(n))
1308 goto found;
1309
1310 /* only record pn and cindex if we are going to be chopping
1311 * bits later. Otherwise we are just wasting cycles.
1312 */
1313 if (n->slen > n->pos) {
1314 pn = n;
1315 cindex = index;
1316 }
1317
1318 n = get_child_rcu(n, index);
1319 if (unlikely(!n))
1320 goto backtrace;
1321 }
1322
1323 /* Step 2: Sort out leaves and begin backtracing for longest prefix */
1324 for (;;) {
1325 /* record the pointer where our next node pointer is stored */
1326 struct key_vector __rcu **cptr = n->tnode;
1327
1328 /* This test verifies that none of the bits that differ
1329 * between the key and the prefix exist in the region of
1330 * the lsb and higher in the prefix.
1331 */
1332 if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos))
1333 goto backtrace;
1334
1335 /* exit out and process leaf */
1336 if (unlikely(IS_LEAF(n)))
1337 break;
1338
1339 /* Don't bother recording parent info. Since we are in
1340 * prefix match mode we will have to come back to wherever
1341 * we started this traversal anyway
1342 */
1343
1344 while ((n = rcu_dereference(*cptr)) == NULL) {
1345 backtrace:
1346 #ifdef CONFIG_IP_FIB_TRIE_STATS
1347 if (!n)
1348 this_cpu_inc(stats->null_node_hit);
1349 #endif
1350 /* If we are at cindex 0 there are no more bits for
1351 * us to strip at this level so we must ascend back
1352 * up one level to see if there are any more bits to
1353 * be stripped there.
1354 */
1355 while (!cindex) {
1356 t_key pkey = pn->key;
1357
1358 /* If we don't have a parent then there is
1359 * nothing for us to do as we do not have any
1360 * further nodes to parse.
1361 */
1362 if (IS_TRIE(pn))
1363 return -EAGAIN;
1364 #ifdef CONFIG_IP_FIB_TRIE_STATS
1365 this_cpu_inc(stats->backtrack);
1366 #endif
1367 /* Get Child's index */
1368 pn = node_parent_rcu(pn);
1369 cindex = get_index(pkey, pn);
1370 }
1371
1372 /* strip the least significant bit from the cindex */
1373 cindex &= cindex - 1;
1374
1375 /* grab pointer for next child node */
1376 cptr = &pn->tnode[cindex];
1377 }
1378 }
1379
1380 found:
1381 /* this line carries forward the xor from earlier in the function */
1382 index = key ^ n->key;
1383
1384 /* Step 3: Process the leaf, if that fails fall back to backtracing */
1385 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
1386 struct fib_info *fi = fa->fa_info;
1387 int nhsel, err;
1388
1389 if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) {
1390 if (index >= (1ul << fa->fa_slen))
1391 continue;
1392 }
1393 if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
1394 continue;
1395 if (fi->fib_dead)
1396 continue;
1397 if (fa->fa_info->fib_scope < flp->flowi4_scope)
1398 continue;
1399 fib_alias_accessed(fa);
1400 err = fib_props[fa->fa_type].error;
1401 if (unlikely(err < 0)) {
1402 #ifdef CONFIG_IP_FIB_TRIE_STATS
1403 this_cpu_inc(stats->semantic_match_passed);
1404 #endif
1405 return err;
1406 }
1407 if (fi->fib_flags & RTNH_F_DEAD)
1408 continue;
1409 for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) {
1410 const struct fib_nh *nh = &fi->fib_nh[nhsel];
1411 struct in_device *in_dev = __in_dev_get_rcu(nh->nh_dev);
1412
1413 if (nh->nh_flags & RTNH_F_DEAD)
1414 continue;
1415 if (in_dev &&
1416 IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) &&
1417 nh->nh_flags & RTNH_F_LINKDOWN &&
1418 !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE))
1419 continue;
1420 if (!(flp->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) {
1421 if (flp->flowi4_oif &&
1422 flp->flowi4_oif != nh->nh_oif)
1423 continue;
1424 }
1425
1426 if (!(fib_flags & FIB_LOOKUP_NOREF))
1427 atomic_inc(&fi->fib_clntref);
1428
1429 res->prefixlen = KEYLENGTH - fa->fa_slen;
1430 res->nh_sel = nhsel;
1431 res->type = fa->fa_type;
1432 res->scope = fi->fib_scope;
1433 res->fi = fi;
1434 res->table = tb;
1435 res->fa_head = &n->leaf;
1436 #ifdef CONFIG_IP_FIB_TRIE_STATS
1437 this_cpu_inc(stats->semantic_match_passed);
1438 #endif
1439 trace_fib_table_lookup_nh(nh);
1440
1441 return err;
1442 }
1443 }
1444 #ifdef CONFIG_IP_FIB_TRIE_STATS
1445 this_cpu_inc(stats->semantic_match_miss);
1446 #endif
1447 goto backtrace;
1448 }
1449 EXPORT_SYMBOL_GPL(fib_table_lookup);
1450
1451 static void fib_remove_alias(struct trie *t, struct key_vector *tp,
1452 struct key_vector *l, struct fib_alias *old)
1453 {
1454 /* record the location of the previous list_info entry */
1455 struct hlist_node **pprev = old->fa_list.pprev;
1456 struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next);
1457
1458 /* remove the fib_alias from the list */
1459 hlist_del_rcu(&old->fa_list);
1460
1461 /* if we emptied the list this leaf will be freed and we can sort
1462 * out parent suffix lengths as a part of trie_rebalance
1463 */
1464 if (hlist_empty(&l->leaf)) {
1465 if (tp->slen == l->slen)
1466 node_pull_suffix(tp, tp->pos);
1467 put_child_root(tp, l->key, NULL);
1468 node_free(l);
1469 trie_rebalance(t, tp);
1470 return;
1471 }
1472
1473 /* only access fa if it is pointing at the last valid hlist_node */
1474 if (*pprev)
1475 return;
1476
1477 /* update the trie with the latest suffix length */
1478 l->slen = fa->fa_slen;
1479 node_pull_suffix(tp, fa->fa_slen);
1480 }
1481
1482 /* Caller must hold RTNL. */
1483 int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
1484 {
1485 struct trie *t = (struct trie *) tb->tb_data;
1486 struct fib_alias *fa, *fa_to_delete;
1487 struct key_vector *l, *tp;
1488 u8 plen = cfg->fc_dst_len;
1489 u8 slen = KEYLENGTH - plen;
1490 u8 tos = cfg->fc_tos;
1491 u32 key;
1492
1493 if (plen > KEYLENGTH)
1494 return -EINVAL;
1495
1496 key = ntohl(cfg->fc_dst);
1497
1498 if ((plen < KEYLENGTH) && (key << plen))
1499 return -EINVAL;
1500
1501 l = fib_find_node(t, &tp, key);
1502 if (!l)
1503 return -ESRCH;
1504
1505 fa = fib_find_alias(&l->leaf, slen, tos, 0, tb->tb_id);
1506 if (!fa)
1507 return -ESRCH;
1508
1509 pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
1510
1511 fa_to_delete = NULL;
1512 hlist_for_each_entry_from(fa, fa_list) {
1513 struct fib_info *fi = fa->fa_info;
1514
1515 if ((fa->fa_slen != slen) ||
1516 (fa->tb_id != tb->tb_id) ||
1517 (fa->fa_tos != tos))
1518 break;
1519
1520 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
1521 (cfg->fc_scope == RT_SCOPE_NOWHERE ||
1522 fa->fa_info->fib_scope == cfg->fc_scope) &&
1523 (!cfg->fc_prefsrc ||
1524 fi->fib_prefsrc == cfg->fc_prefsrc) &&
1525 (!cfg->fc_protocol ||
1526 fi->fib_protocol == cfg->fc_protocol) &&
1527 fib_nh_match(cfg, fi) == 0) {
1528 fa_to_delete = fa;
1529 break;
1530 }
1531 }
1532
1533 if (!fa_to_delete)
1534 return -ESRCH;
1535
1536 switchdev_fib_ipv4_del(key, plen, fa_to_delete->fa_info, tos,
1537 cfg->fc_type, tb->tb_id);
1538
1539 rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id,
1540 &cfg->fc_nlinfo, 0);
1541
1542 if (!plen)
1543 tb->tb_num_default--;
1544
1545 fib_remove_alias(t, tp, l, fa_to_delete);
1546
1547 if (fa_to_delete->fa_state & FA_S_ACCESSED)
1548 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1549
1550 fib_release_info(fa_to_delete->fa_info);
1551 alias_free_mem_rcu(fa_to_delete);
1552 return 0;
1553 }
1554
1555 /* Scan for the next leaf starting at the provided key value */
1556 static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key)
1557 {
1558 struct key_vector *pn, *n = *tn;
1559 unsigned long cindex;
1560
1561 /* this loop is meant to try and find the key in the trie */
1562 do {
1563 /* record parent and next child index */
1564 pn = n;
1565 cindex = (key > pn->key) ? get_index(key, pn) : 0;
1566
1567 if (cindex >> pn->bits)
1568 break;
1569
1570 /* descend into the next child */
1571 n = get_child_rcu(pn, cindex++);
1572 if (!n)
1573 break;
1574
1575 /* guarantee forward progress on the keys */
1576 if (IS_LEAF(n) && (n->key >= key))
1577 goto found;
1578 } while (IS_TNODE(n));
1579
1580 /* this loop will search for the next leaf with a greater key */
1581 while (!IS_TRIE(pn)) {
1582 /* if we exhausted the parent node we will need to climb */
1583 if (cindex >= (1ul << pn->bits)) {
1584 t_key pkey = pn->key;
1585
1586 pn = node_parent_rcu(pn);
1587 cindex = get_index(pkey, pn) + 1;
1588 continue;
1589 }
1590
1591 /* grab the next available node */
1592 n = get_child_rcu(pn, cindex++);
1593 if (!n)
1594 continue;
1595
1596 /* no need to compare keys since we bumped the index */
1597 if (IS_LEAF(n))
1598 goto found;
1599
1600 /* Rescan start scanning in new node */
1601 pn = n;
1602 cindex = 0;
1603 }
1604
1605 *tn = pn;
1606 return NULL; /* Root of trie */
1607 found:
1608 /* if we are at the limit for keys just return NULL for the tnode */
1609 *tn = pn;
1610 return n;
1611 }
1612
1613 static void fib_trie_free(struct fib_table *tb)
1614 {
1615 struct trie *t = (struct trie *)tb->tb_data;
1616 struct key_vector *pn = t->kv;
1617 unsigned long cindex = 1;
1618 struct hlist_node *tmp;
1619 struct fib_alias *fa;
1620
1621 /* walk trie in reverse order and free everything */
1622 for (;;) {
1623 struct key_vector *n;
1624
1625 if (!(cindex--)) {
1626 t_key pkey = pn->key;
1627
1628 if (IS_TRIE(pn))
1629 break;
1630
1631 n = pn;
1632 pn = node_parent(pn);
1633
1634 /* drop emptied tnode */
1635 put_child_root(pn, n->key, NULL);
1636 node_free(n);
1637
1638 cindex = get_index(pkey, pn);
1639
1640 continue;
1641 }
1642
1643 /* grab the next available node */
1644 n = get_child(pn, cindex);
1645 if (!n)
1646 continue;
1647
1648 if (IS_TNODE(n)) {
1649 /* record pn and cindex for leaf walking */
1650 pn = n;
1651 cindex = 1ul << n->bits;
1652
1653 continue;
1654 }
1655
1656 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1657 hlist_del_rcu(&fa->fa_list);
1658 alias_free_mem_rcu(fa);
1659 }
1660
1661 put_child_root(pn, n->key, NULL);
1662 node_free(n);
1663 }
1664
1665 #ifdef CONFIG_IP_FIB_TRIE_STATS
1666 free_percpu(t->stats);
1667 #endif
1668 kfree(tb);
1669 }
1670
1671 struct fib_table *fib_trie_unmerge(struct fib_table *oldtb)
1672 {
1673 struct trie *ot = (struct trie *)oldtb->tb_data;
1674 struct key_vector *l, *tp = ot->kv;
1675 struct fib_table *local_tb;
1676 struct fib_alias *fa;
1677 struct trie *lt;
1678 t_key key = 0;
1679
1680 if (oldtb->tb_data == oldtb->__data)
1681 return oldtb;
1682
1683 local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL);
1684 if (!local_tb)
1685 return NULL;
1686
1687 lt = (struct trie *)local_tb->tb_data;
1688
1689 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
1690 struct key_vector *local_l = NULL, *local_tp;
1691
1692 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
1693 struct fib_alias *new_fa;
1694
1695 if (local_tb->tb_id != fa->tb_id)
1696 continue;
1697
1698 /* clone fa for new local table */
1699 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1700 if (!new_fa)
1701 goto out;
1702
1703 memcpy(new_fa, fa, sizeof(*fa));
1704
1705 /* insert clone into table */
1706 if (!local_l)
1707 local_l = fib_find_node(lt, &local_tp, l->key);
1708
1709 if (fib_insert_alias(lt, local_tp, local_l, new_fa,
1710 NULL, l->key)) {
1711 kmem_cache_free(fn_alias_kmem, new_fa);
1712 goto out;
1713 }
1714 }
1715
1716 /* stop loop if key wrapped back to 0 */
1717 key = l->key + 1;
1718 if (key < l->key)
1719 break;
1720 }
1721
1722 return local_tb;
1723 out:
1724 fib_trie_free(local_tb);
1725
1726 return NULL;
1727 }
1728
1729 /* Caller must hold RTNL */
1730 void fib_table_flush_external(struct fib_table *tb)
1731 {
1732 struct trie *t = (struct trie *)tb->tb_data;
1733 struct key_vector *pn = t->kv;
1734 unsigned long cindex = 1;
1735 struct hlist_node *tmp;
1736 struct fib_alias *fa;
1737
1738 /* walk trie in reverse order */
1739 for (;;) {
1740 unsigned char slen = 0;
1741 struct key_vector *n;
1742
1743 if (!(cindex--)) {
1744 t_key pkey = pn->key;
1745
1746 /* cannot resize the trie vector */
1747 if (IS_TRIE(pn))
1748 break;
1749
1750 /* update the suffix to address pulled leaves */
1751 if (pn->slen > pn->pos)
1752 update_suffix(pn);
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. */
1808 int 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 /* update the suffix to address pulled leaves */
1830 if (pn->slen > pn->pos)
1831 update_suffix(pn);
1832
1833 /* resize completed node */
1834 pn = resize(t, pn);
1835 cindex = get_index(pkey, pn);
1836
1837 continue;
1838 }
1839
1840 /* grab the next available node */
1841 n = get_child(pn, cindex);
1842 if (!n)
1843 continue;
1844
1845 if (IS_TNODE(n)) {
1846 /* record pn and cindex for leaf walking */
1847 pn = n;
1848 cindex = 1ul << n->bits;
1849
1850 continue;
1851 }
1852
1853 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1854 struct fib_info *fi = fa->fa_info;
1855
1856 if (!fi || !(fi->fib_flags & RTNH_F_DEAD)) {
1857 slen = fa->fa_slen;
1858 continue;
1859 }
1860
1861 switchdev_fib_ipv4_del(n->key, KEYLENGTH - fa->fa_slen,
1862 fi, fa->fa_tos, fa->fa_type,
1863 tb->tb_id);
1864 hlist_del_rcu(&fa->fa_list);
1865 fib_release_info(fa->fa_info);
1866 alias_free_mem_rcu(fa);
1867 found++;
1868 }
1869
1870 /* update leaf slen */
1871 n->slen = slen;
1872
1873 if (hlist_empty(&n->leaf)) {
1874 put_child_root(pn, n->key, NULL);
1875 node_free(n);
1876 }
1877 }
1878
1879 pr_debug("trie_flush found=%d\n", found);
1880 return found;
1881 }
1882
1883 static void __trie_free_rcu(struct rcu_head *head)
1884 {
1885 struct fib_table *tb = container_of(head, struct fib_table, rcu);
1886 #ifdef CONFIG_IP_FIB_TRIE_STATS
1887 struct trie *t = (struct trie *)tb->tb_data;
1888
1889 if (tb->tb_data == tb->__data)
1890 free_percpu(t->stats);
1891 #endif /* CONFIG_IP_FIB_TRIE_STATS */
1892 kfree(tb);
1893 }
1894
1895 void fib_free_table(struct fib_table *tb)
1896 {
1897 call_rcu(&tb->rcu, __trie_free_rcu);
1898 }
1899
1900 static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb,
1901 struct sk_buff *skb, struct netlink_callback *cb)
1902 {
1903 __be32 xkey = htonl(l->key);
1904 struct fib_alias *fa;
1905 int i, s_i;
1906
1907 s_i = cb->args[4];
1908 i = 0;
1909
1910 /* rcu_read_lock is hold by caller */
1911 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
1912 if (i < s_i) {
1913 i++;
1914 continue;
1915 }
1916
1917 if (tb->tb_id != fa->tb_id) {
1918 i++;
1919 continue;
1920 }
1921
1922 if (fib_dump_info(skb, NETLINK_CB(cb->skb).portid,
1923 cb->nlh->nlmsg_seq,
1924 RTM_NEWROUTE,
1925 tb->tb_id,
1926 fa->fa_type,
1927 xkey,
1928 KEYLENGTH - fa->fa_slen,
1929 fa->fa_tos,
1930 fa->fa_info, NLM_F_MULTI) < 0) {
1931 cb->args[4] = i;
1932 return -1;
1933 }
1934 i++;
1935 }
1936
1937 cb->args[4] = i;
1938 return skb->len;
1939 }
1940
1941 /* rcu_read_lock needs to be hold by caller from readside */
1942 int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
1943 struct netlink_callback *cb)
1944 {
1945 struct trie *t = (struct trie *)tb->tb_data;
1946 struct key_vector *l, *tp = t->kv;
1947 /* Dump starting at last key.
1948 * Note: 0.0.0.0/0 (ie default) is first key.
1949 */
1950 int count = cb->args[2];
1951 t_key key = cb->args[3];
1952
1953 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
1954 if (fn_trie_dump_leaf(l, tb, skb, cb) < 0) {
1955 cb->args[3] = key;
1956 cb->args[2] = count;
1957 return -1;
1958 }
1959
1960 ++count;
1961 key = l->key + 1;
1962
1963 memset(&cb->args[4], 0,
1964 sizeof(cb->args) - 4*sizeof(cb->args[0]));
1965
1966 /* stop loop if key wrapped back to 0 */
1967 if (key < l->key)
1968 break;
1969 }
1970
1971 cb->args[3] = key;
1972 cb->args[2] = count;
1973
1974 return skb->len;
1975 }
1976
1977 void __init fib_trie_init(void)
1978 {
1979 fn_alias_kmem = kmem_cache_create("ip_fib_alias",
1980 sizeof(struct fib_alias),
1981 0, SLAB_PANIC, NULL);
1982
1983 trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
1984 LEAF_SIZE,
1985 0, SLAB_PANIC, NULL);
1986 }
1987
1988 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias)
1989 {
1990 struct fib_table *tb;
1991 struct trie *t;
1992 size_t sz = sizeof(*tb);
1993
1994 if (!alias)
1995 sz += sizeof(struct trie);
1996
1997 tb = kzalloc(sz, GFP_KERNEL);
1998 if (!tb)
1999 return NULL;
2000
2001 tb->tb_id = id;
2002 tb->tb_num_default = 0;
2003 tb->tb_data = (alias ? alias->__data : tb->__data);
2004
2005 if (alias)
2006 return tb;
2007
2008 t = (struct trie *) tb->tb_data;
2009 t->kv[0].pos = KEYLENGTH;
2010 t->kv[0].slen = KEYLENGTH;
2011 #ifdef CONFIG_IP_FIB_TRIE_STATS
2012 t->stats = alloc_percpu(struct trie_use_stats);
2013 if (!t->stats) {
2014 kfree(tb);
2015 tb = NULL;
2016 }
2017 #endif
2018
2019 return tb;
2020 }
2021
2022 #ifdef CONFIG_PROC_FS
2023 /* Depth first Trie walk iterator */
2024 struct fib_trie_iter {
2025 struct seq_net_private p;
2026 struct fib_table *tb;
2027 struct key_vector *tnode;
2028 unsigned int index;
2029 unsigned int depth;
2030 };
2031
2032 static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter)
2033 {
2034 unsigned long cindex = iter->index;
2035 struct key_vector *pn = iter->tnode;
2036 t_key pkey;
2037
2038 pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
2039 iter->tnode, iter->index, iter->depth);
2040
2041 while (!IS_TRIE(pn)) {
2042 while (cindex < child_length(pn)) {
2043 struct key_vector *n = get_child_rcu(pn, cindex++);
2044
2045 if (!n)
2046 continue;
2047
2048 if (IS_LEAF(n)) {
2049 iter->tnode = pn;
2050 iter->index = cindex;
2051 } else {
2052 /* push down one level */
2053 iter->tnode = n;
2054 iter->index = 0;
2055 ++iter->depth;
2056 }
2057
2058 return n;
2059 }
2060
2061 /* Current node exhausted, pop back up */
2062 pkey = pn->key;
2063 pn = node_parent_rcu(pn);
2064 cindex = get_index(pkey, pn) + 1;
2065 --iter->depth;
2066 }
2067
2068 /* record root node so further searches know we are done */
2069 iter->tnode = pn;
2070 iter->index = 0;
2071
2072 return NULL;
2073 }
2074
2075 static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter,
2076 struct trie *t)
2077 {
2078 struct key_vector *n, *pn;
2079
2080 if (!t)
2081 return NULL;
2082
2083 pn = t->kv;
2084 n = rcu_dereference(pn->tnode[0]);
2085 if (!n)
2086 return NULL;
2087
2088 if (IS_TNODE(n)) {
2089 iter->tnode = n;
2090 iter->index = 0;
2091 iter->depth = 1;
2092 } else {
2093 iter->tnode = pn;
2094 iter->index = 0;
2095 iter->depth = 0;
2096 }
2097
2098 return n;
2099 }
2100
2101 static void trie_collect_stats(struct trie *t, struct trie_stat *s)
2102 {
2103 struct key_vector *n;
2104 struct fib_trie_iter iter;
2105
2106 memset(s, 0, sizeof(*s));
2107
2108 rcu_read_lock();
2109 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) {
2110 if (IS_LEAF(n)) {
2111 struct fib_alias *fa;
2112
2113 s->leaves++;
2114 s->totdepth += iter.depth;
2115 if (iter.depth > s->maxdepth)
2116 s->maxdepth = iter.depth;
2117
2118 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list)
2119 ++s->prefixes;
2120 } else {
2121 s->tnodes++;
2122 if (n->bits < MAX_STAT_DEPTH)
2123 s->nodesizes[n->bits]++;
2124 s->nullpointers += tn_info(n)->empty_children;
2125 }
2126 }
2127 rcu_read_unlock();
2128 }
2129
2130 /*
2131 * This outputs /proc/net/fib_triestats
2132 */
2133 static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
2134 {
2135 unsigned int i, max, pointers, bytes, avdepth;
2136
2137 if (stat->leaves)
2138 avdepth = stat->totdepth*100 / stat->leaves;
2139 else
2140 avdepth = 0;
2141
2142 seq_printf(seq, "\tAver depth: %u.%02d\n",
2143 avdepth / 100, avdepth % 100);
2144 seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth);
2145
2146 seq_printf(seq, "\tLeaves: %u\n", stat->leaves);
2147 bytes = LEAF_SIZE * stat->leaves;
2148
2149 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes);
2150 bytes += sizeof(struct fib_alias) * stat->prefixes;
2151
2152 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);
2153 bytes += TNODE_SIZE(0) * stat->tnodes;
2154
2155 max = MAX_STAT_DEPTH;
2156 while (max > 0 && stat->nodesizes[max-1] == 0)
2157 max--;
2158
2159 pointers = 0;
2160 for (i = 1; i < max; i++)
2161 if (stat->nodesizes[i] != 0) {
2162 seq_printf(seq, " %u: %u", i, stat->nodesizes[i]);
2163 pointers += (1<<i) * stat->nodesizes[i];
2164 }
2165 seq_putc(seq, '\n');
2166 seq_printf(seq, "\tPointers: %u\n", pointers);
2167
2168 bytes += sizeof(struct key_vector *) * pointers;
2169 seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers);
2170 seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024);
2171 }
2172
2173 #ifdef CONFIG_IP_FIB_TRIE_STATS
2174 static void trie_show_usage(struct seq_file *seq,
2175 const struct trie_use_stats __percpu *stats)
2176 {
2177 struct trie_use_stats s = { 0 };
2178 int cpu;
2179
2180 /* loop through all of the CPUs and gather up the stats */
2181 for_each_possible_cpu(cpu) {
2182 const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu);
2183
2184 s.gets += pcpu->gets;
2185 s.backtrack += pcpu->backtrack;
2186 s.semantic_match_passed += pcpu->semantic_match_passed;
2187 s.semantic_match_miss += pcpu->semantic_match_miss;
2188 s.null_node_hit += pcpu->null_node_hit;
2189 s.resize_node_skipped += pcpu->resize_node_skipped;
2190 }
2191
2192 seq_printf(seq, "\nCounters:\n---------\n");
2193 seq_printf(seq, "gets = %u\n", s.gets);
2194 seq_printf(seq, "backtracks = %u\n", s.backtrack);
2195 seq_printf(seq, "semantic match passed = %u\n",
2196 s.semantic_match_passed);
2197 seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss);
2198 seq_printf(seq, "null node hit= %u\n", s.null_node_hit);
2199 seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped);
2200 }
2201 #endif /* CONFIG_IP_FIB_TRIE_STATS */
2202
2203 static void fib_table_print(struct seq_file *seq, struct fib_table *tb)
2204 {
2205 if (tb->tb_id == RT_TABLE_LOCAL)
2206 seq_puts(seq, "Local:\n");
2207 else if (tb->tb_id == RT_TABLE_MAIN)
2208 seq_puts(seq, "Main:\n");
2209 else
2210 seq_printf(seq, "Id %d:\n", tb->tb_id);
2211 }
2212
2213
2214 static int fib_triestat_seq_show(struct seq_file *seq, void *v)
2215 {
2216 struct net *net = (struct net *)seq->private;
2217 unsigned int h;
2218
2219 seq_printf(seq,
2220 "Basic info: size of leaf:"
2221 " %Zd bytes, size of tnode: %Zd bytes.\n",
2222 LEAF_SIZE, TNODE_SIZE(0));
2223
2224 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2225 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2226 struct fib_table *tb;
2227
2228 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2229 struct trie *t = (struct trie *) tb->tb_data;
2230 struct trie_stat stat;
2231
2232 if (!t)
2233 continue;
2234
2235 fib_table_print(seq, tb);
2236
2237 trie_collect_stats(t, &stat);
2238 trie_show_stats(seq, &stat);
2239 #ifdef CONFIG_IP_FIB_TRIE_STATS
2240 trie_show_usage(seq, t->stats);
2241 #endif
2242 }
2243 }
2244
2245 return 0;
2246 }
2247
2248 static int fib_triestat_seq_open(struct inode *inode, struct file *file)
2249 {
2250 return single_open_net(inode, file, fib_triestat_seq_show);
2251 }
2252
2253 static const struct file_operations fib_triestat_fops = {
2254 .owner = THIS_MODULE,
2255 .open = fib_triestat_seq_open,
2256 .read = seq_read,
2257 .llseek = seq_lseek,
2258 .release = single_release_net,
2259 };
2260
2261 static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos)
2262 {
2263 struct fib_trie_iter *iter = seq->private;
2264 struct net *net = seq_file_net(seq);
2265 loff_t idx = 0;
2266 unsigned int h;
2267
2268 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2269 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2270 struct fib_table *tb;
2271
2272 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2273 struct key_vector *n;
2274
2275 for (n = fib_trie_get_first(iter,
2276 (struct trie *) tb->tb_data);
2277 n; n = fib_trie_get_next(iter))
2278 if (pos == idx++) {
2279 iter->tb = tb;
2280 return n;
2281 }
2282 }
2283 }
2284
2285 return NULL;
2286 }
2287
2288 static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
2289 __acquires(RCU)
2290 {
2291 rcu_read_lock();
2292 return fib_trie_get_idx(seq, *pos);
2293 }
2294
2295 static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2296 {
2297 struct fib_trie_iter *iter = seq->private;
2298 struct net *net = seq_file_net(seq);
2299 struct fib_table *tb = iter->tb;
2300 struct hlist_node *tb_node;
2301 unsigned int h;
2302 struct key_vector *n;
2303
2304 ++*pos;
2305 /* next node in same table */
2306 n = fib_trie_get_next(iter);
2307 if (n)
2308 return n;
2309
2310 /* walk rest of this hash chain */
2311 h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);
2312 while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) {
2313 tb = hlist_entry(tb_node, struct fib_table, tb_hlist);
2314 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2315 if (n)
2316 goto found;
2317 }
2318
2319 /* new hash chain */
2320 while (++h < FIB_TABLE_HASHSZ) {
2321 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2322 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2323 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2324 if (n)
2325 goto found;
2326 }
2327 }
2328 return NULL;
2329
2330 found:
2331 iter->tb = tb;
2332 return n;
2333 }
2334
2335 static void fib_trie_seq_stop(struct seq_file *seq, void *v)
2336 __releases(RCU)
2337 {
2338 rcu_read_unlock();
2339 }
2340
2341 static void seq_indent(struct seq_file *seq, int n)
2342 {
2343 while (n-- > 0)
2344 seq_puts(seq, " ");
2345 }
2346
2347 static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
2348 {
2349 switch (s) {
2350 case RT_SCOPE_UNIVERSE: return "universe";
2351 case RT_SCOPE_SITE: return "site";
2352 case RT_SCOPE_LINK: return "link";
2353 case RT_SCOPE_HOST: return "host";
2354 case RT_SCOPE_NOWHERE: return "nowhere";
2355 default:
2356 snprintf(buf, len, "scope=%d", s);
2357 return buf;
2358 }
2359 }
2360
2361 static const char *const rtn_type_names[__RTN_MAX] = {
2362 [RTN_UNSPEC] = "UNSPEC",
2363 [RTN_UNICAST] = "UNICAST",
2364 [RTN_LOCAL] = "LOCAL",
2365 [RTN_BROADCAST] = "BROADCAST",
2366 [RTN_ANYCAST] = "ANYCAST",
2367 [RTN_MULTICAST] = "MULTICAST",
2368 [RTN_BLACKHOLE] = "BLACKHOLE",
2369 [RTN_UNREACHABLE] = "UNREACHABLE",
2370 [RTN_PROHIBIT] = "PROHIBIT",
2371 [RTN_THROW] = "THROW",
2372 [RTN_NAT] = "NAT",
2373 [RTN_XRESOLVE] = "XRESOLVE",
2374 };
2375
2376 static inline const char *rtn_type(char *buf, size_t len, unsigned int t)
2377 {
2378 if (t < __RTN_MAX && rtn_type_names[t])
2379 return rtn_type_names[t];
2380 snprintf(buf, len, "type %u", t);
2381 return buf;
2382 }
2383
2384 /* Pretty print the trie */
2385 static int fib_trie_seq_show(struct seq_file *seq, void *v)
2386 {
2387 const struct fib_trie_iter *iter = seq->private;
2388 struct key_vector *n = v;
2389
2390 if (IS_TRIE(node_parent_rcu(n)))
2391 fib_table_print(seq, iter->tb);
2392
2393 if (IS_TNODE(n)) {
2394 __be32 prf = htonl(n->key);
2395
2396 seq_indent(seq, iter->depth-1);
2397 seq_printf(seq, " +-- %pI4/%zu %u %u %u\n",
2398 &prf, KEYLENGTH - n->pos - n->bits, n->bits,
2399 tn_info(n)->full_children,
2400 tn_info(n)->empty_children);
2401 } else {
2402 __be32 val = htonl(n->key);
2403 struct fib_alias *fa;
2404
2405 seq_indent(seq, iter->depth);
2406 seq_printf(seq, " |-- %pI4\n", &val);
2407
2408 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
2409 char buf1[32], buf2[32];
2410
2411 seq_indent(seq, iter->depth + 1);
2412 seq_printf(seq, " /%zu %s %s",
2413 KEYLENGTH - fa->fa_slen,
2414 rtn_scope(buf1, sizeof(buf1),
2415 fa->fa_info->fib_scope),
2416 rtn_type(buf2, sizeof(buf2),
2417 fa->fa_type));
2418 if (fa->fa_tos)
2419 seq_printf(seq, " tos=%d", fa->fa_tos);
2420 seq_putc(seq, '\n');
2421 }
2422 }
2423
2424 return 0;
2425 }
2426
2427 static const struct seq_operations fib_trie_seq_ops = {
2428 .start = fib_trie_seq_start,
2429 .next = fib_trie_seq_next,
2430 .stop = fib_trie_seq_stop,
2431 .show = fib_trie_seq_show,
2432 };
2433
2434 static int fib_trie_seq_open(struct inode *inode, struct file *file)
2435 {
2436 return seq_open_net(inode, file, &fib_trie_seq_ops,
2437 sizeof(struct fib_trie_iter));
2438 }
2439
2440 static const struct file_operations fib_trie_fops = {
2441 .owner = THIS_MODULE,
2442 .open = fib_trie_seq_open,
2443 .read = seq_read,
2444 .llseek = seq_lseek,
2445 .release = seq_release_net,
2446 };
2447
2448 struct fib_route_iter {
2449 struct seq_net_private p;
2450 struct fib_table *main_tb;
2451 struct key_vector *tnode;
2452 loff_t pos;
2453 t_key key;
2454 };
2455
2456 static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter,
2457 loff_t pos)
2458 {
2459 struct key_vector *l, **tp = &iter->tnode;
2460 t_key key;
2461
2462 /* use cached location of previously found key */
2463 if (iter->pos > 0 && pos >= iter->pos) {
2464 key = iter->key;
2465 } else {
2466 iter->pos = 1;
2467 key = 0;
2468 }
2469
2470 pos -= iter->pos;
2471
2472 while ((l = leaf_walk_rcu(tp, key)) && (pos-- > 0)) {
2473 key = l->key + 1;
2474 iter->pos++;
2475 l = NULL;
2476
2477 /* handle unlikely case of a key wrap */
2478 if (!key)
2479 break;
2480 }
2481
2482 if (l)
2483 iter->key = l->key; /* remember it */
2484 else
2485 iter->pos = 0; /* forget it */
2486
2487 return l;
2488 }
2489
2490 static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos)
2491 __acquires(RCU)
2492 {
2493 struct fib_route_iter *iter = seq->private;
2494 struct fib_table *tb;
2495 struct trie *t;
2496
2497 rcu_read_lock();
2498
2499 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
2500 if (!tb)
2501 return NULL;
2502
2503 iter->main_tb = tb;
2504 t = (struct trie *)tb->tb_data;
2505 iter->tnode = t->kv;
2506
2507 if (*pos != 0)
2508 return fib_route_get_idx(iter, *pos);
2509
2510 iter->pos = 0;
2511 iter->key = KEY_MAX;
2512
2513 return SEQ_START_TOKEN;
2514 }
2515
2516 static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2517 {
2518 struct fib_route_iter *iter = seq->private;
2519 struct key_vector *l = NULL;
2520 t_key key = iter->key + 1;
2521
2522 ++*pos;
2523
2524 /* only allow key of 0 for start of sequence */
2525 if ((v == SEQ_START_TOKEN) || key)
2526 l = leaf_walk_rcu(&iter->tnode, key);
2527
2528 if (l) {
2529 iter->key = l->key;
2530 iter->pos++;
2531 } else {
2532 iter->pos = 0;
2533 }
2534
2535 return l;
2536 }
2537
2538 static void fib_route_seq_stop(struct seq_file *seq, void *v)
2539 __releases(RCU)
2540 {
2541 rcu_read_unlock();
2542 }
2543
2544 static unsigned int fib_flag_trans(int type, __be32 mask, const struct fib_info *fi)
2545 {
2546 unsigned int flags = 0;
2547
2548 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT)
2549 flags = RTF_REJECT;
2550 if (fi && fi->fib_nh->nh_gw)
2551 flags |= RTF_GATEWAY;
2552 if (mask == htonl(0xFFFFFFFF))
2553 flags |= RTF_HOST;
2554 flags |= RTF_UP;
2555 return flags;
2556 }
2557
2558 /*
2559 * This outputs /proc/net/route.
2560 * The format of the file is not supposed to be changed
2561 * and needs to be same as fib_hash output to avoid breaking
2562 * legacy utilities
2563 */
2564 static int fib_route_seq_show(struct seq_file *seq, void *v)
2565 {
2566 struct fib_route_iter *iter = seq->private;
2567 struct fib_table *tb = iter->main_tb;
2568 struct fib_alias *fa;
2569 struct key_vector *l = v;
2570 __be32 prefix;
2571
2572 if (v == SEQ_START_TOKEN) {
2573 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
2574 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
2575 "\tWindow\tIRTT");
2576 return 0;
2577 }
2578
2579 prefix = htonl(l->key);
2580
2581 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2582 const struct fib_info *fi = fa->fa_info;
2583 __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen);
2584 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);
2585
2586 if ((fa->fa_type == RTN_BROADCAST) ||
2587 (fa->fa_type == RTN_MULTICAST))
2588 continue;
2589
2590 if (fa->tb_id != tb->tb_id)
2591 continue;
2592
2593 seq_setwidth(seq, 127);
2594
2595 if (fi)
2596 seq_printf(seq,
2597 "%s\t%08X\t%08X\t%04X\t%d\t%u\t"
2598 "%d\t%08X\t%d\t%u\t%u",
2599 fi->fib_dev ? fi->fib_dev->name : "*",
2600 prefix,
2601 fi->fib_nh->nh_gw, flags, 0, 0,
2602 fi->fib_priority,
2603 mask,
2604 (fi->fib_advmss ?
2605 fi->fib_advmss + 40 : 0),
2606 fi->fib_window,
2607 fi->fib_rtt >> 3);
2608 else
2609 seq_printf(seq,
2610 "*\t%08X\t%08X\t%04X\t%d\t%u\t"
2611 "%d\t%08X\t%d\t%u\t%u",
2612 prefix, 0, flags, 0, 0, 0,
2613 mask, 0, 0, 0);
2614
2615 seq_pad(seq, '\n');
2616 }
2617
2618 return 0;
2619 }
2620
2621 static const struct seq_operations fib_route_seq_ops = {
2622 .start = fib_route_seq_start,
2623 .next = fib_route_seq_next,
2624 .stop = fib_route_seq_stop,
2625 .show = fib_route_seq_show,
2626 };
2627
2628 static int fib_route_seq_open(struct inode *inode, struct file *file)
2629 {
2630 return seq_open_net(inode, file, &fib_route_seq_ops,
2631 sizeof(struct fib_route_iter));
2632 }
2633
2634 static const struct file_operations fib_route_fops = {
2635 .owner = THIS_MODULE,
2636 .open = fib_route_seq_open,
2637 .read = seq_read,
2638 .llseek = seq_lseek,
2639 .release = seq_release_net,
2640 };
2641
2642 int __net_init fib_proc_init(struct net *net)
2643 {
2644 if (!proc_create("fib_trie", S_IRUGO, net->proc_net, &fib_trie_fops))
2645 goto out1;
2646
2647 if (!proc_create("fib_triestat", S_IRUGO, net->proc_net,
2648 &fib_triestat_fops))
2649 goto out2;
2650
2651 if (!proc_create("route", S_IRUGO, net->proc_net, &fib_route_fops))
2652 goto out3;
2653
2654 return 0;
2655
2656 out3:
2657 remove_proc_entry("fib_triestat", net->proc_net);
2658 out2:
2659 remove_proc_entry("fib_trie", net->proc_net);
2660 out1:
2661 return -ENOMEM;
2662 }
2663
2664 void __net_exit fib_proc_exit(struct net *net)
2665 {
2666 remove_proc_entry("fib_trie", net->proc_net);
2667 remove_proc_entry("fib_triestat", net->proc_net);
2668 remove_proc_entry("route", net->proc_net);
2669 }
2670
2671 #endif /* CONFIG_PROC_FS */
2672
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