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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 * https://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#include <linux/cache.h>
39#include <linux/uaccess.h>
40#include <linux/bitops.h>
41#include <linux/types.h>
42#include <linux/kernel.h>
43#include <linux/mm.h>
44#include <linux/string.h>
45#include <linux/socket.h>
46#include <linux/sockios.h>
47#include <linux/errno.h>
48#include <linux/in.h>
49#include <linux/inet.h>
50#include <linux/inetdevice.h>
51#include <linux/netdevice.h>
52#include <linux/if_arp.h>
53#include <linux/proc_fs.h>
54#include <linux/rcupdate.h>
55#include <linux/skbuff.h>
56#include <linux/netlink.h>
57#include <linux/init.h>
58#include <linux/list.h>
59#include <linux/slab.h>
60#include <linux/export.h>
61#include <linux/vmalloc.h>
62#include <linux/notifier.h>
63#include <net/net_namespace.h>
64#include <net/ip.h>
65#include <net/protocol.h>
66#include <net/route.h>
67#include <net/tcp.h>
68#include <net/sock.h>
69#include <net/ip_fib.h>
70#include <net/fib_notifier.h>
71#include <trace/events/fib.h>
72#include "fib_lookup.h"
73
74static int call_fib_entry_notifier(struct notifier_block *nb,
75 enum fib_event_type event_type, u32 dst,
76 int dst_len, struct fib_alias *fa,
77 struct netlink_ext_ack *extack)
78{
79 struct fib_entry_notifier_info info = {
80 .info.extack = extack,
81 .dst = dst,
82 .dst_len = dst_len,
83 .fi = fa->fa_info,
84 .tos = fa->fa_tos,
85 .type = fa->fa_type,
86 .tb_id = fa->tb_id,
87 };
88 return call_fib4_notifier(nb, event_type, &info.info);
89}
90
91static int call_fib_entry_notifiers(struct net *net,
92 enum fib_event_type event_type, u32 dst,
93 int dst_len, struct fib_alias *fa,
94 struct netlink_ext_ack *extack)
95{
96 struct fib_entry_notifier_info info = {
97 .info.extack = extack,
98 .dst = dst,
99 .dst_len = dst_len,
100 .fi = fa->fa_info,
101 .tos = fa->fa_tos,
102 .type = fa->fa_type,
103 .tb_id = fa->tb_id,
104 };
105 return call_fib4_notifiers(net, event_type, &info.info);
106}
107
108#define MAX_STAT_DEPTH 32
109
110#define KEYLENGTH (8*sizeof(t_key))
111#define KEY_MAX ((t_key)~0)
112
113typedef unsigned int t_key;
114
115#define IS_TRIE(n) ((n)->pos >= KEYLENGTH)
116#define IS_TNODE(n) ((n)->bits)
117#define IS_LEAF(n) (!(n)->bits)
118
119struct key_vector {
120 t_key key;
121 unsigned char pos; /* 2log(KEYLENGTH) bits needed */
122 unsigned char bits; /* 2log(KEYLENGTH) bits needed */
123 unsigned char slen;
124 union {
125 /* This list pointer if valid if (pos | bits) == 0 (LEAF) */
126 struct hlist_head leaf;
127 /* This array is valid if (pos | bits) > 0 (TNODE) */
128 struct key_vector __rcu *tnode[0];
129 };
130};
131
132struct tnode {
133 struct rcu_head rcu;
134 t_key empty_children; /* KEYLENGTH bits needed */
135 t_key full_children; /* KEYLENGTH bits needed */
136 struct key_vector __rcu *parent;
137 struct key_vector kv[1];
138#define tn_bits kv[0].bits
139};
140
141#define TNODE_SIZE(n) offsetof(struct tnode, kv[0].tnode[n])
142#define LEAF_SIZE TNODE_SIZE(1)
143
144#ifdef CONFIG_IP_FIB_TRIE_STATS
145struct trie_use_stats {
146 unsigned int gets;
147 unsigned int backtrack;
148 unsigned int semantic_match_passed;
149 unsigned int semantic_match_miss;
150 unsigned int null_node_hit;
151 unsigned int resize_node_skipped;
152};
153#endif
154
155struct trie_stat {
156 unsigned int totdepth;
157 unsigned int maxdepth;
158 unsigned int tnodes;
159 unsigned int leaves;
160 unsigned int nullpointers;
161 unsigned int prefixes;
162 unsigned int nodesizes[MAX_STAT_DEPTH];
163};
164
165struct trie {
166 struct key_vector kv[1];
167#ifdef CONFIG_IP_FIB_TRIE_STATS
168 struct trie_use_stats __percpu *stats;
169#endif
170};
171
172static struct key_vector *resize(struct trie *t, struct key_vector *tn);
173static unsigned int tnode_free_size;
174
175/*
176 * synchronize_rcu after call_rcu for outstanding dirty memory; it should be
177 * especially useful before resizing the root node with PREEMPT_NONE configs;
178 * the value was obtained experimentally, aiming to avoid visible slowdown.
179 */
180unsigned int sysctl_fib_sync_mem = 512 * 1024;
181unsigned int sysctl_fib_sync_mem_min = 64 * 1024;
182unsigned int sysctl_fib_sync_mem_max = 64 * 1024 * 1024;
183
184static struct kmem_cache *fn_alias_kmem __ro_after_init;
185static struct kmem_cache *trie_leaf_kmem __ro_after_init;
186
187static inline struct tnode *tn_info(struct key_vector *kv)
188{
189 return container_of(kv, struct tnode, kv[0]);
190}
191
192/* caller must hold RTNL */
193#define node_parent(tn) rtnl_dereference(tn_info(tn)->parent)
194#define get_child(tn, i) rtnl_dereference((tn)->tnode[i])
195
196/* caller must hold RCU read lock or RTNL */
197#define node_parent_rcu(tn) rcu_dereference_rtnl(tn_info(tn)->parent)
198#define get_child_rcu(tn, i) rcu_dereference_rtnl((tn)->tnode[i])
199
200/* wrapper for rcu_assign_pointer */
201static inline void node_set_parent(struct key_vector *n, struct key_vector *tp)
202{
203 if (n)
204 rcu_assign_pointer(tn_info(n)->parent, tp);
205}
206
207#define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER(tn_info(n)->parent, p)
208
209/* This provides us with the number of children in this node, in the case of a
210 * leaf this will return 0 meaning none of the children are accessible.
211 */
212static inline unsigned long child_length(const struct key_vector *tn)
213{
214 return (1ul << tn->bits) & ~(1ul);
215}
216
217#define get_cindex(key, kv) (((key) ^ (kv)->key) >> (kv)->pos)
218
219static inline unsigned long get_index(t_key key, struct key_vector *kv)
220{
221 unsigned long index = key ^ kv->key;
222
223 if ((BITS_PER_LONG <= KEYLENGTH) && (KEYLENGTH == kv->pos))
224 return 0;
225
226 return index >> kv->pos;
227}
228
229/* To understand this stuff, an understanding of keys and all their bits is
230 * necessary. Every node in the trie has a key associated with it, but not
231 * all of the bits in that key are significant.
232 *
233 * Consider a node 'n' and its parent 'tp'.
234 *
235 * If n is a leaf, every bit in its key is significant. Its presence is
236 * necessitated by path compression, since during a tree traversal (when
237 * searching for a leaf - unless we are doing an insertion) we will completely
238 * ignore all skipped bits we encounter. Thus we need to verify, at the end of
239 * a potentially successful search, that we have indeed been walking the
240 * correct key path.
241 *
242 * Note that we can never "miss" the correct key in the tree if present by
243 * following the wrong path. Path compression ensures that segments of the key
244 * that are the same for all keys with a given prefix are skipped, but the
245 * skipped part *is* identical for each node in the subtrie below the skipped
246 * bit! trie_insert() in this implementation takes care of that.
247 *
248 * if n is an internal node - a 'tnode' here, the various parts of its key
249 * have many different meanings.
250 *
251 * Example:
252 * _________________________________________________________________
253 * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
254 * -----------------------------------------------------------------
255 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
256 *
257 * _________________________________________________________________
258 * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
259 * -----------------------------------------------------------------
260 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
261 *
262 * tp->pos = 22
263 * tp->bits = 3
264 * n->pos = 13
265 * n->bits = 4
266 *
267 * First, let's just ignore the bits that come before the parent tp, that is
268 * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this
269 * point we do not use them for anything.
270 *
271 * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the
272 * index into the parent's child array. That is, they will be used to find
273 * 'n' among tp's children.
274 *
275 * The bits from (n->pos + n->bits) to (tp->pos - 1) - "S" - are skipped bits
276 * for the node n.
277 *
278 * All the bits we have seen so far are significant to the node n. The rest
279 * of the bits are really not needed or indeed known in n->key.
280 *
281 * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into
282 * n's child array, and will of course be different for each child.
283 *
284 * The rest of the bits, from 0 to (n->pos -1) - "u" - are completely unknown
285 * at this point.
286 */
287
288static const int halve_threshold = 25;
289static const int inflate_threshold = 50;
290static const int halve_threshold_root = 15;
291static const int inflate_threshold_root = 30;
292
293static void __alias_free_mem(struct rcu_head *head)
294{
295 struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
296 kmem_cache_free(fn_alias_kmem, fa);
297}
298
299static inline void alias_free_mem_rcu(struct fib_alias *fa)
300{
301 call_rcu(&fa->rcu, __alias_free_mem);
302}
303
304#define TNODE_VMALLOC_MAX \
305 ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *))
306
307static void __node_free_rcu(struct rcu_head *head)
308{
309 struct tnode *n = container_of(head, struct tnode, rcu);
310
311 if (!n->tn_bits)
312 kmem_cache_free(trie_leaf_kmem, n);
313 else
314 kvfree(n);
315}
316
317#define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu)
318
319static struct tnode *tnode_alloc(int bits)
320{
321 size_t size;
322
323 /* verify bits is within bounds */
324 if (bits > TNODE_VMALLOC_MAX)
325 return NULL;
326
327 /* determine size and verify it is non-zero and didn't overflow */
328 size = TNODE_SIZE(1ul << bits);
329
330 if (size <= PAGE_SIZE)
331 return kzalloc(size, GFP_KERNEL);
332 else
333 return vzalloc(size);
334}
335
336static inline void empty_child_inc(struct key_vector *n)
337{
338 tn_info(n)->empty_children++;
339
340 if (!tn_info(n)->empty_children)
341 tn_info(n)->full_children++;
342}
343
344static inline void empty_child_dec(struct key_vector *n)
345{
346 if (!tn_info(n)->empty_children)
347 tn_info(n)->full_children--;
348
349 tn_info(n)->empty_children--;
350}
351
352static struct key_vector *leaf_new(t_key key, struct fib_alias *fa)
353{
354 struct key_vector *l;
355 struct tnode *kv;
356
357 kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
358 if (!kv)
359 return NULL;
360
361 /* initialize key vector */
362 l = kv->kv;
363 l->key = key;
364 l->pos = 0;
365 l->bits = 0;
366 l->slen = fa->fa_slen;
367
368 /* link leaf to fib alias */
369 INIT_HLIST_HEAD(&l->leaf);
370 hlist_add_head(&fa->fa_list, &l->leaf);
371
372 return l;
373}
374
375static struct key_vector *tnode_new(t_key key, int pos, int bits)
376{
377 unsigned int shift = pos + bits;
378 struct key_vector *tn;
379 struct tnode *tnode;
380
381 /* verify bits and pos their msb bits clear and values are valid */
382 BUG_ON(!bits || (shift > KEYLENGTH));
383
384 tnode = tnode_alloc(bits);
385 if (!tnode)
386 return NULL;
387
388 pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0),
389 sizeof(struct key_vector *) << bits);
390
391 if (bits == KEYLENGTH)
392 tnode->full_children = 1;
393 else
394 tnode->empty_children = 1ul << bits;
395
396 tn = tnode->kv;
397 tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
398 tn->pos = pos;
399 tn->bits = bits;
400 tn->slen = pos;
401
402 return tn;
403}
404
405/* Check whether a tnode 'n' is "full", i.e. it is an internal node
406 * and no bits are skipped. See discussion in dyntree paper p. 6
407 */
408static inline int tnode_full(struct key_vector *tn, struct key_vector *n)
409{
410 return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n);
411}
412
413/* Add a child at position i overwriting the old value.
414 * Update the value of full_children and empty_children.
415 */
416static void put_child(struct key_vector *tn, unsigned long i,
417 struct key_vector *n)
418{
419 struct key_vector *chi = get_child(tn, i);
420 int isfull, wasfull;
421
422 BUG_ON(i >= child_length(tn));
423
424 /* update emptyChildren, overflow into fullChildren */
425 if (!n && chi)
426 empty_child_inc(tn);
427 if (n && !chi)
428 empty_child_dec(tn);
429
430 /* update fullChildren */
431 wasfull = tnode_full(tn, chi);
432 isfull = tnode_full(tn, n);
433
434 if (wasfull && !isfull)
435 tn_info(tn)->full_children--;
436 else if (!wasfull && isfull)
437 tn_info(tn)->full_children++;
438
439 if (n && (tn->slen < n->slen))
440 tn->slen = n->slen;
441
442 rcu_assign_pointer(tn->tnode[i], n);
443}
444
445static void update_children(struct key_vector *tn)
446{
447 unsigned long i;
448
449 /* update all of the child parent pointers */
450 for (i = child_length(tn); i;) {
451 struct key_vector *inode = get_child(tn, --i);
452
453 if (!inode)
454 continue;
455
456 /* Either update the children of a tnode that
457 * already belongs to us or update the child
458 * to point to ourselves.
459 */
460 if (node_parent(inode) == tn)
461 update_children(inode);
462 else
463 node_set_parent(inode, tn);
464 }
465}
466
467static inline void put_child_root(struct key_vector *tp, t_key key,
468 struct key_vector *n)
469{
470 if (IS_TRIE(tp))
471 rcu_assign_pointer(tp->tnode[0], n);
472 else
473 put_child(tp, get_index(key, tp), n);
474}
475
476static inline void tnode_free_init(struct key_vector *tn)
477{
478 tn_info(tn)->rcu.next = NULL;
479}
480
481static inline void tnode_free_append(struct key_vector *tn,
482 struct key_vector *n)
483{
484 tn_info(n)->rcu.next = tn_info(tn)->rcu.next;
485 tn_info(tn)->rcu.next = &tn_info(n)->rcu;
486}
487
488static void tnode_free(struct key_vector *tn)
489{
490 struct callback_head *head = &tn_info(tn)->rcu;
491
492 while (head) {
493 head = head->next;
494 tnode_free_size += TNODE_SIZE(1ul << tn->bits);
495 node_free(tn);
496
497 tn = container_of(head, struct tnode, rcu)->kv;
498 }
499
500 if (tnode_free_size >= sysctl_fib_sync_mem) {
501 tnode_free_size = 0;
502 synchronize_rcu();
503 }
504}
505
506static struct key_vector *replace(struct trie *t,
507 struct key_vector *oldtnode,
508 struct key_vector *tn)
509{
510 struct key_vector *tp = node_parent(oldtnode);
511 unsigned long i;
512
513 /* setup the parent pointer out of and back into this node */
514 NODE_INIT_PARENT(tn, tp);
515 put_child_root(tp, tn->key, tn);
516
517 /* update all of the child parent pointers */
518 update_children(tn);
519
520 /* all pointers should be clean so we are done */
521 tnode_free(oldtnode);
522
523 /* resize children now that oldtnode is freed */
524 for (i = child_length(tn); i;) {
525 struct key_vector *inode = get_child(tn, --i);
526
527 /* resize child node */
528 if (tnode_full(tn, inode))
529 tn = resize(t, inode);
530 }
531
532 return tp;
533}
534
535static struct key_vector *inflate(struct trie *t,
536 struct key_vector *oldtnode)
537{
538 struct key_vector *tn;
539 unsigned long i;
540 t_key m;
541
542 pr_debug("In inflate\n");
543
544 tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1);
545 if (!tn)
546 goto notnode;
547
548 /* prepare oldtnode to be freed */
549 tnode_free_init(oldtnode);
550
551 /* Assemble all of the pointers in our cluster, in this case that
552 * represents all of the pointers out of our allocated nodes that
553 * point to existing tnodes and the links between our allocated
554 * nodes.
555 */
556 for (i = child_length(oldtnode), m = 1u << tn->pos; i;) {
557 struct key_vector *inode = get_child(oldtnode, --i);
558 struct key_vector *node0, *node1;
559 unsigned long j, k;
560
561 /* An empty child */
562 if (!inode)
563 continue;
564
565 /* A leaf or an internal node with skipped bits */
566 if (!tnode_full(oldtnode, inode)) {
567 put_child(tn, get_index(inode->key, tn), inode);
568 continue;
569 }
570
571 /* drop the node in the old tnode free list */
572 tnode_free_append(oldtnode, inode);
573
574 /* An internal node with two children */
575 if (inode->bits == 1) {
576 put_child(tn, 2 * i + 1, get_child(inode, 1));
577 put_child(tn, 2 * i, get_child(inode, 0));
578 continue;
579 }
580
581 /* We will replace this node 'inode' with two new
582 * ones, 'node0' and 'node1', each with half of the
583 * original children. The two new nodes will have
584 * a position one bit further down the key and this
585 * means that the "significant" part of their keys
586 * (see the discussion near the top of this file)
587 * will differ by one bit, which will be "0" in
588 * node0's key and "1" in node1's key. Since we are
589 * moving the key position by one step, the bit that
590 * we are moving away from - the bit at position
591 * (tn->pos) - is the one that will differ between
592 * node0 and node1. So... we synthesize that bit in the
593 * two new keys.
594 */
595 node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1);
596 if (!node1)
597 goto nomem;
598 node0 = tnode_new(inode->key, inode->pos, inode->bits - 1);
599
600 tnode_free_append(tn, node1);
601 if (!node0)
602 goto nomem;
603 tnode_free_append(tn, node0);
604
605 /* populate child pointers in new nodes */
606 for (k = child_length(inode), j = k / 2; j;) {
607 put_child(node1, --j, get_child(inode, --k));
608 put_child(node0, j, get_child(inode, j));
609 put_child(node1, --j, get_child(inode, --k));
610 put_child(node0, j, get_child(inode, j));
611 }
612
613 /* link new nodes to parent */
614 NODE_INIT_PARENT(node1, tn);
615 NODE_INIT_PARENT(node0, tn);
616
617 /* link parent to nodes */
618 put_child(tn, 2 * i + 1, node1);
619 put_child(tn, 2 * i, node0);
620 }
621
622 /* setup the parent pointers into and out of this node */
623 return replace(t, oldtnode, tn);
624nomem:
625 /* all pointers should be clean so we are done */
626 tnode_free(tn);
627notnode:
628 return NULL;
629}
630
631static struct key_vector *halve(struct trie *t,
632 struct key_vector *oldtnode)
633{
634 struct key_vector *tn;
635 unsigned long i;
636
637 pr_debug("In halve\n");
638
639 tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1);
640 if (!tn)
641 goto notnode;
642
643 /* prepare oldtnode to be freed */
644 tnode_free_init(oldtnode);
645
646 /* Assemble all of the pointers in our cluster, in this case that
647 * represents all of the pointers out of our allocated nodes that
648 * point to existing tnodes and the links between our allocated
649 * nodes.
650 */
651 for (i = child_length(oldtnode); i;) {
652 struct key_vector *node1 = get_child(oldtnode, --i);
653 struct key_vector *node0 = get_child(oldtnode, --i);
654 struct key_vector *inode;
655
656 /* At least one of the children is empty */
657 if (!node1 || !node0) {
658 put_child(tn, i / 2, node1 ? : node0);
659 continue;
660 }
661
662 /* Two nonempty children */
663 inode = tnode_new(node0->key, oldtnode->pos, 1);
664 if (!inode)
665 goto nomem;
666 tnode_free_append(tn, inode);
667
668 /* initialize pointers out of node */
669 put_child(inode, 1, node1);
670 put_child(inode, 0, node0);
671 NODE_INIT_PARENT(inode, tn);
672
673 /* link parent to node */
674 put_child(tn, i / 2, inode);
675 }
676
677 /* setup the parent pointers into and out of this node */
678 return replace(t, oldtnode, tn);
679nomem:
680 /* all pointers should be clean so we are done */
681 tnode_free(tn);
682notnode:
683 return NULL;
684}
685
686static struct key_vector *collapse(struct trie *t,
687 struct key_vector *oldtnode)
688{
689 struct key_vector *n, *tp;
690 unsigned long i;
691
692 /* scan the tnode looking for that one child that might still exist */
693 for (n = NULL, i = child_length(oldtnode); !n && i;)
694 n = get_child(oldtnode, --i);
695
696 /* compress one level */
697 tp = node_parent(oldtnode);
698 put_child_root(tp, oldtnode->key, n);
699 node_set_parent(n, tp);
700
701 /* drop dead node */
702 node_free(oldtnode);
703
704 return tp;
705}
706
707static unsigned char update_suffix(struct key_vector *tn)
708{
709 unsigned char slen = tn->pos;
710 unsigned long stride, i;
711 unsigned char slen_max;
712
713 /* only vector 0 can have a suffix length greater than or equal to
714 * tn->pos + tn->bits, the second highest node will have a suffix
715 * length at most of tn->pos + tn->bits - 1
716 */
717 slen_max = min_t(unsigned char, tn->pos + tn->bits - 1, tn->slen);
718
719 /* search though the list of children looking for nodes that might
720 * have a suffix greater than the one we currently have. This is
721 * why we start with a stride of 2 since a stride of 1 would
722 * represent the nodes with suffix length equal to tn->pos
723 */
724 for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) {
725 struct key_vector *n = get_child(tn, i);
726
727 if (!n || (n->slen <= slen))
728 continue;
729
730 /* update stride and slen based on new value */
731 stride <<= (n->slen - slen);
732 slen = n->slen;
733 i &= ~(stride - 1);
734
735 /* stop searching if we have hit the maximum possible value */
736 if (slen >= slen_max)
737 break;
738 }
739
740 tn->slen = slen;
741
742 return slen;
743}
744
745/* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
746 * the Helsinki University of Technology and Matti Tikkanen of Nokia
747 * Telecommunications, page 6:
748 * "A node is doubled if the ratio of non-empty children to all
749 * children in the *doubled* node is at least 'high'."
750 *
751 * 'high' in this instance is the variable 'inflate_threshold'. It
752 * is expressed as a percentage, so we multiply it with
753 * child_length() and instead of multiplying by 2 (since the
754 * child array will be doubled by inflate()) and multiplying
755 * the left-hand side by 100 (to handle the percentage thing) we
756 * multiply the left-hand side by 50.
757 *
758 * The left-hand side may look a bit weird: child_length(tn)
759 * - tn->empty_children is of course the number of non-null children
760 * in the current node. tn->full_children is the number of "full"
761 * children, that is non-null tnodes with a skip value of 0.
762 * All of those will be doubled in the resulting inflated tnode, so
763 * we just count them one extra time here.
764 *
765 * A clearer way to write this would be:
766 *
767 * to_be_doubled = tn->full_children;
768 * not_to_be_doubled = child_length(tn) - tn->empty_children -
769 * tn->full_children;
770 *
771 * new_child_length = child_length(tn) * 2;
772 *
773 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
774 * new_child_length;
775 * if (new_fill_factor >= inflate_threshold)
776 *
777 * ...and so on, tho it would mess up the while () loop.
778 *
779 * anyway,
780 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
781 * inflate_threshold
782 *
783 * avoid a division:
784 * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
785 * inflate_threshold * new_child_length
786 *
787 * expand not_to_be_doubled and to_be_doubled, and shorten:
788 * 100 * (child_length(tn) - tn->empty_children +
789 * tn->full_children) >= inflate_threshold * new_child_length
790 *
791 * expand new_child_length:
792 * 100 * (child_length(tn) - tn->empty_children +
793 * tn->full_children) >=
794 * inflate_threshold * child_length(tn) * 2
795 *
796 * shorten again:
797 * 50 * (tn->full_children + child_length(tn) -
798 * tn->empty_children) >= inflate_threshold *
799 * child_length(tn)
800 *
801 */
802static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn)
803{
804 unsigned long used = child_length(tn);
805 unsigned long threshold = used;
806
807 /* Keep root node larger */
808 threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold;
809 used -= tn_info(tn)->empty_children;
810 used += tn_info(tn)->full_children;
811
812 /* if bits == KEYLENGTH then pos = 0, and will fail below */
813
814 return (used > 1) && tn->pos && ((50 * used) >= threshold);
815}
816
817static inline bool should_halve(struct key_vector *tp, struct key_vector *tn)
818{
819 unsigned long used = child_length(tn);
820 unsigned long threshold = used;
821
822 /* Keep root node larger */
823 threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold;
824 used -= tn_info(tn)->empty_children;
825
826 /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */
827
828 return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold);
829}
830
831static inline bool should_collapse(struct key_vector *tn)
832{
833 unsigned long used = child_length(tn);
834
835 used -= tn_info(tn)->empty_children;
836
837 /* account for bits == KEYLENGTH case */
838 if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children)
839 used -= KEY_MAX;
840
841 /* One child or none, time to drop us from the trie */
842 return used < 2;
843}
844
845#define MAX_WORK 10
846static struct key_vector *resize(struct trie *t, struct key_vector *tn)
847{
848#ifdef CONFIG_IP_FIB_TRIE_STATS
849 struct trie_use_stats __percpu *stats = t->stats;
850#endif
851 struct key_vector *tp = node_parent(tn);
852 unsigned long cindex = get_index(tn->key, tp);
853 int max_work = MAX_WORK;
854
855 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
856 tn, inflate_threshold, halve_threshold);
857
858 /* track the tnode via the pointer from the parent instead of
859 * doing it ourselves. This way we can let RCU fully do its
860 * thing without us interfering
861 */
862 BUG_ON(tn != get_child(tp, cindex));
863
864 /* Double as long as the resulting node has a number of
865 * nonempty nodes that are above the threshold.
866 */
867 while (should_inflate(tp, tn) && max_work) {
868 tp = inflate(t, tn);
869 if (!tp) {
870#ifdef CONFIG_IP_FIB_TRIE_STATS
871 this_cpu_inc(stats->resize_node_skipped);
872#endif
873 break;
874 }
875
876 max_work--;
877 tn = get_child(tp, cindex);
878 }
879
880 /* update parent in case inflate failed */
881 tp = node_parent(tn);
882
883 /* Return if at least one inflate is run */
884 if (max_work != MAX_WORK)
885 return tp;
886
887 /* Halve as long as the number of empty children in this
888 * node is above threshold.
889 */
890 while (should_halve(tp, tn) && max_work) {
891 tp = halve(t, tn);
892 if (!tp) {
893#ifdef CONFIG_IP_FIB_TRIE_STATS
894 this_cpu_inc(stats->resize_node_skipped);
895#endif
896 break;
897 }
898
899 max_work--;
900 tn = get_child(tp, cindex);
901 }
902
903 /* Only one child remains */
904 if (should_collapse(tn))
905 return collapse(t, tn);
906
907 /* update parent in case halve failed */
908 return node_parent(tn);
909}
910
911static void node_pull_suffix(struct key_vector *tn, unsigned char slen)
912{
913 unsigned char node_slen = tn->slen;
914
915 while ((node_slen > tn->pos) && (node_slen > slen)) {
916 slen = update_suffix(tn);
917 if (node_slen == slen)
918 break;
919
920 tn = node_parent(tn);
921 node_slen = tn->slen;
922 }
923}
924
925static void node_push_suffix(struct key_vector *tn, unsigned char slen)
926{
927 while (tn->slen < slen) {
928 tn->slen = slen;
929 tn = node_parent(tn);
930 }
931}
932
933/* rcu_read_lock needs to be hold by caller from readside */
934static struct key_vector *fib_find_node(struct trie *t,
935 struct key_vector **tp, u32 key)
936{
937 struct key_vector *pn, *n = t->kv;
938 unsigned long index = 0;
939
940 do {
941 pn = n;
942 n = get_child_rcu(n, index);
943
944 if (!n)
945 break;
946
947 index = get_cindex(key, n);
948
949 /* This bit of code is a bit tricky but it combines multiple
950 * checks into a single check. The prefix consists of the
951 * prefix plus zeros for the bits in the cindex. The index
952 * is the difference between the key and this value. From
953 * this we can actually derive several pieces of data.
954 * if (index >= (1ul << bits))
955 * we have a mismatch in skip bits and failed
956 * else
957 * we know the value is cindex
958 *
959 * This check is safe even if bits == KEYLENGTH due to the
960 * fact that we can only allocate a node with 32 bits if a
961 * long is greater than 32 bits.
962 */
963 if (index >= (1ul << n->bits)) {
964 n = NULL;
965 break;
966 }
967
968 /* keep searching until we find a perfect match leaf or NULL */
969 } while (IS_TNODE(n));
970
971 *tp = pn;
972
973 return n;
974}
975
976/* Return the first fib alias matching TOS with
977 * priority less than or equal to PRIO.
978 * If 'find_first' is set, return the first matching
979 * fib alias, regardless of TOS and priority.
980 */
981static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen,
982 u8 tos, u32 prio, u32 tb_id,
983 bool find_first)
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 (find_first)
1000 return fa;
1001 if (fa->fa_tos > tos)
1002 continue;
1003 if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos)
1004 return fa;
1005 }
1006
1007 return NULL;
1008}
1009
1010static struct fib_alias *
1011fib_find_matching_alias(struct net *net, const struct fib_rt_info *fri)
1012{
1013 u8 slen = KEYLENGTH - fri->dst_len;
1014 struct key_vector *l, *tp;
1015 struct fib_table *tb;
1016 struct fib_alias *fa;
1017 struct trie *t;
1018
1019 tb = fib_get_table(net, fri->tb_id);
1020 if (!tb)
1021 return NULL;
1022
1023 t = (struct trie *)tb->tb_data;
1024 l = fib_find_node(t, &tp, be32_to_cpu(fri->dst));
1025 if (!l)
1026 return NULL;
1027
1028 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
1029 if (fa->fa_slen == slen && fa->tb_id == fri->tb_id &&
1030 fa->fa_tos == fri->tos && fa->fa_info == fri->fi &&
1031 fa->fa_type == fri->type)
1032 return fa;
1033 }
1034
1035 return NULL;
1036}
1037
1038void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri)
1039{
1040 struct fib_alias *fa_match;
1041
1042 rcu_read_lock();
1043
1044 fa_match = fib_find_matching_alias(net, fri);
1045 if (!fa_match)
1046 goto out;
1047
1048 fa_match->offload = fri->offload;
1049 fa_match->trap = fri->trap;
1050
1051out:
1052 rcu_read_unlock();
1053}
1054EXPORT_SYMBOL_GPL(fib_alias_hw_flags_set);
1055
1056static void trie_rebalance(struct trie *t, struct key_vector *tn)
1057{
1058 while (!IS_TRIE(tn))
1059 tn = resize(t, tn);
1060}
1061
1062static int fib_insert_node(struct trie *t, struct key_vector *tp,
1063 struct fib_alias *new, t_key key)
1064{
1065 struct key_vector *n, *l;
1066
1067 l = leaf_new(key, new);
1068 if (!l)
1069 goto noleaf;
1070
1071 /* retrieve child from parent node */
1072 n = get_child(tp, get_index(key, tp));
1073
1074 /* Case 2: n is a LEAF or a TNODE and the key doesn't match.
1075 *
1076 * Add a new tnode here
1077 * first tnode need some special handling
1078 * leaves us in position for handling as case 3
1079 */
1080 if (n) {
1081 struct key_vector *tn;
1082
1083 tn = tnode_new(key, __fls(key ^ n->key), 1);
1084 if (!tn)
1085 goto notnode;
1086
1087 /* initialize routes out of node */
1088 NODE_INIT_PARENT(tn, tp);
1089 put_child(tn, get_index(key, tn) ^ 1, n);
1090
1091 /* start adding routes into the node */
1092 put_child_root(tp, key, tn);
1093 node_set_parent(n, tn);
1094
1095 /* parent now has a NULL spot where the leaf can go */
1096 tp = tn;
1097 }
1098
1099 /* Case 3: n is NULL, and will just insert a new leaf */
1100 node_push_suffix(tp, new->fa_slen);
1101 NODE_INIT_PARENT(l, tp);
1102 put_child_root(tp, key, l);
1103 trie_rebalance(t, tp);
1104
1105 return 0;
1106notnode:
1107 node_free(l);
1108noleaf:
1109 return -ENOMEM;
1110}
1111
1112static int fib_insert_alias(struct trie *t, struct key_vector *tp,
1113 struct key_vector *l, struct fib_alias *new,
1114 struct fib_alias *fa, t_key key)
1115{
1116 if (!l)
1117 return fib_insert_node(t, tp, new, key);
1118
1119 if (fa) {
1120 hlist_add_before_rcu(&new->fa_list, &fa->fa_list);
1121 } else {
1122 struct fib_alias *last;
1123
1124 hlist_for_each_entry(last, &l->leaf, fa_list) {
1125 if (new->fa_slen < last->fa_slen)
1126 break;
1127 if ((new->fa_slen == last->fa_slen) &&
1128 (new->tb_id > last->tb_id))
1129 break;
1130 fa = last;
1131 }
1132
1133 if (fa)
1134 hlist_add_behind_rcu(&new->fa_list, &fa->fa_list);
1135 else
1136 hlist_add_head_rcu(&new->fa_list, &l->leaf);
1137 }
1138
1139 /* if we added to the tail node then we need to update slen */
1140 if (l->slen < new->fa_slen) {
1141 l->slen = new->fa_slen;
1142 node_push_suffix(tp, new->fa_slen);
1143 }
1144
1145 return 0;
1146}
1147
1148static bool fib_valid_key_len(u32 key, u8 plen, struct netlink_ext_ack *extack)
1149{
1150 if (plen > KEYLENGTH) {
1151 NL_SET_ERR_MSG(extack, "Invalid prefix length");
1152 return false;
1153 }
1154
1155 if ((plen < KEYLENGTH) && (key << plen)) {
1156 NL_SET_ERR_MSG(extack,
1157 "Invalid prefix for given prefix length");
1158 return false;
1159 }
1160
1161 return true;
1162}
1163
1164static void fib_remove_alias(struct trie *t, struct key_vector *tp,
1165 struct key_vector *l, struct fib_alias *old);
1166
1167/* Caller must hold RTNL. */
1168int fib_table_insert(struct net *net, struct fib_table *tb,
1169 struct fib_config *cfg, struct netlink_ext_ack *extack)
1170{
1171 struct trie *t = (struct trie *)tb->tb_data;
1172 struct fib_alias *fa, *new_fa;
1173 struct key_vector *l, *tp;
1174 u16 nlflags = NLM_F_EXCL;
1175 struct fib_info *fi;
1176 u8 plen = cfg->fc_dst_len;
1177 u8 slen = KEYLENGTH - plen;
1178 u8 tos = cfg->fc_tos;
1179 u32 key;
1180 int err;
1181
1182 key = ntohl(cfg->fc_dst);
1183
1184 if (!fib_valid_key_len(key, plen, extack))
1185 return -EINVAL;
1186
1187 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
1188
1189 fi = fib_create_info(cfg, extack);
1190 if (IS_ERR(fi)) {
1191 err = PTR_ERR(fi);
1192 goto err;
1193 }
1194
1195 l = fib_find_node(t, &tp, key);
1196 fa = l ? fib_find_alias(&l->leaf, slen, tos, fi->fib_priority,
1197 tb->tb_id, false) : NULL;
1198
1199 /* Now fa, if non-NULL, points to the first fib alias
1200 * with the same keys [prefix,tos,priority], if such key already
1201 * exists or to the node before which we will insert new one.
1202 *
1203 * If fa is NULL, we will need to allocate a new one and
1204 * insert to the tail of the section matching the suffix length
1205 * of the new alias.
1206 */
1207
1208 if (fa && fa->fa_tos == tos &&
1209 fa->fa_info->fib_priority == fi->fib_priority) {
1210 struct fib_alias *fa_first, *fa_match;
1211
1212 err = -EEXIST;
1213 if (cfg->fc_nlflags & NLM_F_EXCL)
1214 goto out;
1215
1216 nlflags &= ~NLM_F_EXCL;
1217
1218 /* We have 2 goals:
1219 * 1. Find exact match for type, scope, fib_info to avoid
1220 * duplicate routes
1221 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
1222 */
1223 fa_match = NULL;
1224 fa_first = fa;
1225 hlist_for_each_entry_from(fa, fa_list) {
1226 if ((fa->fa_slen != slen) ||
1227 (fa->tb_id != tb->tb_id) ||
1228 (fa->fa_tos != tos))
1229 break;
1230 if (fa->fa_info->fib_priority != fi->fib_priority)
1231 break;
1232 if (fa->fa_type == cfg->fc_type &&
1233 fa->fa_info == fi) {
1234 fa_match = fa;
1235 break;
1236 }
1237 }
1238
1239 if (cfg->fc_nlflags & NLM_F_REPLACE) {
1240 struct fib_info *fi_drop;
1241 u8 state;
1242
1243 nlflags |= NLM_F_REPLACE;
1244 fa = fa_first;
1245 if (fa_match) {
1246 if (fa == fa_match)
1247 err = 0;
1248 goto out;
1249 }
1250 err = -ENOBUFS;
1251 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1252 if (!new_fa)
1253 goto out;
1254
1255 fi_drop = fa->fa_info;
1256 new_fa->fa_tos = fa->fa_tos;
1257 new_fa->fa_info = fi;
1258 new_fa->fa_type = cfg->fc_type;
1259 state = fa->fa_state;
1260 new_fa->fa_state = state & ~FA_S_ACCESSED;
1261 new_fa->fa_slen = fa->fa_slen;
1262 new_fa->tb_id = tb->tb_id;
1263 new_fa->fa_default = -1;
1264 new_fa->offload = 0;
1265 new_fa->trap = 0;
1266
1267 hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list);
1268
1269 if (fib_find_alias(&l->leaf, fa->fa_slen, 0, 0,
1270 tb->tb_id, true) == new_fa) {
1271 enum fib_event_type fib_event;
1272
1273 fib_event = FIB_EVENT_ENTRY_REPLACE;
1274 err = call_fib_entry_notifiers(net, fib_event,
1275 key, plen,
1276 new_fa, extack);
1277 if (err) {
1278 hlist_replace_rcu(&new_fa->fa_list,
1279 &fa->fa_list);
1280 goto out_free_new_fa;
1281 }
1282 }
1283
1284 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
1285 tb->tb_id, &cfg->fc_nlinfo, nlflags);
1286
1287 alias_free_mem_rcu(fa);
1288
1289 fib_release_info(fi_drop);
1290 if (state & FA_S_ACCESSED)
1291 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1292
1293 goto succeeded;
1294 }
1295 /* Error if we find a perfect match which
1296 * uses the same scope, type, and nexthop
1297 * information.
1298 */
1299 if (fa_match)
1300 goto out;
1301
1302 if (cfg->fc_nlflags & NLM_F_APPEND)
1303 nlflags |= NLM_F_APPEND;
1304 else
1305 fa = fa_first;
1306 }
1307 err = -ENOENT;
1308 if (!(cfg->fc_nlflags & NLM_F_CREATE))
1309 goto out;
1310
1311 nlflags |= NLM_F_CREATE;
1312 err = -ENOBUFS;
1313 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1314 if (!new_fa)
1315 goto out;
1316
1317 new_fa->fa_info = fi;
1318 new_fa->fa_tos = tos;
1319 new_fa->fa_type = cfg->fc_type;
1320 new_fa->fa_state = 0;
1321 new_fa->fa_slen = slen;
1322 new_fa->tb_id = tb->tb_id;
1323 new_fa->fa_default = -1;
1324 new_fa->offload = 0;
1325 new_fa->trap = 0;
1326
1327 /* Insert new entry to the list. */
1328 err = fib_insert_alias(t, tp, l, new_fa, fa, key);
1329 if (err)
1330 goto out_free_new_fa;
1331
1332 /* The alias was already inserted, so the node must exist. */
1333 l = l ? l : fib_find_node(t, &tp, key);
1334 if (WARN_ON_ONCE(!l))
1335 goto out_free_new_fa;
1336
1337 if (fib_find_alias(&l->leaf, new_fa->fa_slen, 0, 0, tb->tb_id, true) ==
1338 new_fa) {
1339 enum fib_event_type fib_event;
1340
1341 fib_event = FIB_EVENT_ENTRY_REPLACE;
1342 err = call_fib_entry_notifiers(net, fib_event, key, plen,
1343 new_fa, extack);
1344 if (err)
1345 goto out_remove_new_fa;
1346 }
1347
1348 if (!plen)
1349 tb->tb_num_default++;
1350
1351 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1352 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id,
1353 &cfg->fc_nlinfo, nlflags);
1354succeeded:
1355 return 0;
1356
1357out_remove_new_fa:
1358 fib_remove_alias(t, tp, l, new_fa);
1359out_free_new_fa:
1360 kmem_cache_free(fn_alias_kmem, new_fa);
1361out:
1362 fib_release_info(fi);
1363err:
1364 return err;
1365}
1366
1367static inline t_key prefix_mismatch(t_key key, struct key_vector *n)
1368{
1369 t_key prefix = n->key;
1370
1371 return (key ^ prefix) & (prefix | -prefix);
1372}
1373
1374bool fib_lookup_good_nhc(const struct fib_nh_common *nhc, int fib_flags,
1375 const struct flowi4 *flp)
1376{
1377 if (nhc->nhc_flags & RTNH_F_DEAD)
1378 return false;
1379
1380 if (ip_ignore_linkdown(nhc->nhc_dev) &&
1381 nhc->nhc_flags & RTNH_F_LINKDOWN &&
1382 !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE))
1383 return false;
1384
1385 if (!(flp->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) {
1386 if (flp->flowi4_oif &&
1387 flp->flowi4_oif != nhc->nhc_oif)
1388 return false;
1389 }
1390
1391 return true;
1392}
1393
1394/* should be called with rcu_read_lock */
1395int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
1396 struct fib_result *res, int fib_flags)
1397{
1398 struct trie *t = (struct trie *) tb->tb_data;
1399#ifdef CONFIG_IP_FIB_TRIE_STATS
1400 struct trie_use_stats __percpu *stats = t->stats;
1401#endif
1402 const t_key key = ntohl(flp->daddr);
1403 struct key_vector *n, *pn;
1404 struct fib_alias *fa;
1405 unsigned long index;
1406 t_key cindex;
1407
1408 pn = t->kv;
1409 cindex = 0;
1410
1411 n = get_child_rcu(pn, cindex);
1412 if (!n) {
1413 trace_fib_table_lookup(tb->tb_id, flp, NULL, -EAGAIN);
1414 return -EAGAIN;
1415 }
1416
1417#ifdef CONFIG_IP_FIB_TRIE_STATS
1418 this_cpu_inc(stats->gets);
1419#endif
1420
1421 /* Step 1: Travel to the longest prefix match in the trie */
1422 for (;;) {
1423 index = get_cindex(key, n);
1424
1425 /* This bit of code is a bit tricky but it combines multiple
1426 * checks into a single check. The prefix consists of the
1427 * prefix plus zeros for the "bits" in the prefix. The index
1428 * is the difference between the key and this value. From
1429 * this we can actually derive several pieces of data.
1430 * if (index >= (1ul << bits))
1431 * we have a mismatch in skip bits and failed
1432 * else
1433 * we know the value is cindex
1434 *
1435 * This check is safe even if bits == KEYLENGTH due to the
1436 * fact that we can only allocate a node with 32 bits if a
1437 * long is greater than 32 bits.
1438 */
1439 if (index >= (1ul << n->bits))
1440 break;
1441
1442 /* we have found a leaf. Prefixes have already been compared */
1443 if (IS_LEAF(n))
1444 goto found;
1445
1446 /* only record pn and cindex if we are going to be chopping
1447 * bits later. Otherwise we are just wasting cycles.
1448 */
1449 if (n->slen > n->pos) {
1450 pn = n;
1451 cindex = index;
1452 }
1453
1454 n = get_child_rcu(n, index);
1455 if (unlikely(!n))
1456 goto backtrace;
1457 }
1458
1459 /* Step 2: Sort out leaves and begin backtracing for longest prefix */
1460 for (;;) {
1461 /* record the pointer where our next node pointer is stored */
1462 struct key_vector __rcu **cptr = n->tnode;
1463
1464 /* This test verifies that none of the bits that differ
1465 * between the key and the prefix exist in the region of
1466 * the lsb and higher in the prefix.
1467 */
1468 if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos))
1469 goto backtrace;
1470
1471 /* exit out and process leaf */
1472 if (unlikely(IS_LEAF(n)))
1473 break;
1474
1475 /* Don't bother recording parent info. Since we are in
1476 * prefix match mode we will have to come back to wherever
1477 * we started this traversal anyway
1478 */
1479
1480 while ((n = rcu_dereference(*cptr)) == NULL) {
1481backtrace:
1482#ifdef CONFIG_IP_FIB_TRIE_STATS
1483 if (!n)
1484 this_cpu_inc(stats->null_node_hit);
1485#endif
1486 /* If we are at cindex 0 there are no more bits for
1487 * us to strip at this level so we must ascend back
1488 * up one level to see if there are any more bits to
1489 * be stripped there.
1490 */
1491 while (!cindex) {
1492 t_key pkey = pn->key;
1493
1494 /* If we don't have a parent then there is
1495 * nothing for us to do as we do not have any
1496 * further nodes to parse.
1497 */
1498 if (IS_TRIE(pn)) {
1499 trace_fib_table_lookup(tb->tb_id, flp,
1500 NULL, -EAGAIN);
1501 return -EAGAIN;
1502 }
1503#ifdef CONFIG_IP_FIB_TRIE_STATS
1504 this_cpu_inc(stats->backtrack);
1505#endif
1506 /* Get Child's index */
1507 pn = node_parent_rcu(pn);
1508 cindex = get_index(pkey, pn);
1509 }
1510
1511 /* strip the least significant bit from the cindex */
1512 cindex &= cindex - 1;
1513
1514 /* grab pointer for next child node */
1515 cptr = &pn->tnode[cindex];
1516 }
1517 }
1518
1519found:
1520 /* this line carries forward the xor from earlier in the function */
1521 index = key ^ n->key;
1522
1523 /* Step 3: Process the leaf, if that fails fall back to backtracing */
1524 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
1525 struct fib_info *fi = fa->fa_info;
1526 struct fib_nh_common *nhc;
1527 int nhsel, err;
1528
1529 if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) {
1530 if (index >= (1ul << fa->fa_slen))
1531 continue;
1532 }
1533 if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
1534 continue;
1535 if (fi->fib_dead)
1536 continue;
1537 if (fa->fa_info->fib_scope < flp->flowi4_scope)
1538 continue;
1539 fib_alias_accessed(fa);
1540 err = fib_props[fa->fa_type].error;
1541 if (unlikely(err < 0)) {
1542out_reject:
1543#ifdef CONFIG_IP_FIB_TRIE_STATS
1544 this_cpu_inc(stats->semantic_match_passed);
1545#endif
1546 trace_fib_table_lookup(tb->tb_id, flp, NULL, err);
1547 return err;
1548 }
1549 if (fi->fib_flags & RTNH_F_DEAD)
1550 continue;
1551
1552 if (unlikely(fi->nh)) {
1553 if (nexthop_is_blackhole(fi->nh)) {
1554 err = fib_props[RTN_BLACKHOLE].error;
1555 goto out_reject;
1556 }
1557
1558 nhc = nexthop_get_nhc_lookup(fi->nh, fib_flags, flp,
1559 &nhsel);
1560 if (nhc)
1561 goto set_result;
1562 goto miss;
1563 }
1564
1565 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) {
1566 nhc = fib_info_nhc(fi, nhsel);
1567
1568 if (!fib_lookup_good_nhc(nhc, fib_flags, flp))
1569 continue;
1570set_result:
1571 if (!(fib_flags & FIB_LOOKUP_NOREF))
1572 refcount_inc(&fi->fib_clntref);
1573
1574 res->prefix = htonl(n->key);
1575 res->prefixlen = KEYLENGTH - fa->fa_slen;
1576 res->nh_sel = nhsel;
1577 res->nhc = nhc;
1578 res->type = fa->fa_type;
1579 res->scope = fi->fib_scope;
1580 res->fi = fi;
1581 res->table = tb;
1582 res->fa_head = &n->leaf;
1583#ifdef CONFIG_IP_FIB_TRIE_STATS
1584 this_cpu_inc(stats->semantic_match_passed);
1585#endif
1586 trace_fib_table_lookup(tb->tb_id, flp, nhc, err);
1587
1588 return err;
1589 }
1590 }
1591miss:
1592#ifdef CONFIG_IP_FIB_TRIE_STATS
1593 this_cpu_inc(stats->semantic_match_miss);
1594#endif
1595 goto backtrace;
1596}
1597EXPORT_SYMBOL_GPL(fib_table_lookup);
1598
1599static void fib_remove_alias(struct trie *t, struct key_vector *tp,
1600 struct key_vector *l, struct fib_alias *old)
1601{
1602 /* record the location of the previous list_info entry */
1603 struct hlist_node **pprev = old->fa_list.pprev;
1604 struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next);
1605
1606 /* remove the fib_alias from the list */
1607 hlist_del_rcu(&old->fa_list);
1608
1609 /* if we emptied the list this leaf will be freed and we can sort
1610 * out parent suffix lengths as a part of trie_rebalance
1611 */
1612 if (hlist_empty(&l->leaf)) {
1613 if (tp->slen == l->slen)
1614 node_pull_suffix(tp, tp->pos);
1615 put_child_root(tp, l->key, NULL);
1616 node_free(l);
1617 trie_rebalance(t, tp);
1618 return;
1619 }
1620
1621 /* only access fa if it is pointing at the last valid hlist_node */
1622 if (*pprev)
1623 return;
1624
1625 /* update the trie with the latest suffix length */
1626 l->slen = fa->fa_slen;
1627 node_pull_suffix(tp, fa->fa_slen);
1628}
1629
1630static void fib_notify_alias_delete(struct net *net, u32 key,
1631 struct hlist_head *fah,
1632 struct fib_alias *fa_to_delete,
1633 struct netlink_ext_ack *extack)
1634{
1635 struct fib_alias *fa_next, *fa_to_notify;
1636 u32 tb_id = fa_to_delete->tb_id;
1637 u8 slen = fa_to_delete->fa_slen;
1638 enum fib_event_type fib_event;
1639
1640 /* Do not notify if we do not care about the route. */
1641 if (fib_find_alias(fah, slen, 0, 0, tb_id, true) != fa_to_delete)
1642 return;
1643
1644 /* Determine if the route should be replaced by the next route in the
1645 * list.
1646 */
1647 fa_next = hlist_entry_safe(fa_to_delete->fa_list.next,
1648 struct fib_alias, fa_list);
1649 if (fa_next && fa_next->fa_slen == slen && fa_next->tb_id == tb_id) {
1650 fib_event = FIB_EVENT_ENTRY_REPLACE;
1651 fa_to_notify = fa_next;
1652 } else {
1653 fib_event = FIB_EVENT_ENTRY_DEL;
1654 fa_to_notify = fa_to_delete;
1655 }
1656 call_fib_entry_notifiers(net, fib_event, key, KEYLENGTH - slen,
1657 fa_to_notify, extack);
1658}
1659
1660/* Caller must hold RTNL. */
1661int fib_table_delete(struct net *net, struct fib_table *tb,
1662 struct fib_config *cfg, struct netlink_ext_ack *extack)
1663{
1664 struct trie *t = (struct trie *) tb->tb_data;
1665 struct fib_alias *fa, *fa_to_delete;
1666 struct key_vector *l, *tp;
1667 u8 plen = cfg->fc_dst_len;
1668 u8 slen = KEYLENGTH - plen;
1669 u8 tos = cfg->fc_tos;
1670 u32 key;
1671
1672 key = ntohl(cfg->fc_dst);
1673
1674 if (!fib_valid_key_len(key, plen, extack))
1675 return -EINVAL;
1676
1677 l = fib_find_node(t, &tp, key);
1678 if (!l)
1679 return -ESRCH;
1680
1681 fa = fib_find_alias(&l->leaf, slen, tos, 0, tb->tb_id, false);
1682 if (!fa)
1683 return -ESRCH;
1684
1685 pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
1686
1687 fa_to_delete = NULL;
1688 hlist_for_each_entry_from(fa, fa_list) {
1689 struct fib_info *fi = fa->fa_info;
1690
1691 if ((fa->fa_slen != slen) ||
1692 (fa->tb_id != tb->tb_id) ||
1693 (fa->fa_tos != tos))
1694 break;
1695
1696 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
1697 (cfg->fc_scope == RT_SCOPE_NOWHERE ||
1698 fa->fa_info->fib_scope == cfg->fc_scope) &&
1699 (!cfg->fc_prefsrc ||
1700 fi->fib_prefsrc == cfg->fc_prefsrc) &&
1701 (!cfg->fc_protocol ||
1702 fi->fib_protocol == cfg->fc_protocol) &&
1703 fib_nh_match(net, cfg, fi, extack) == 0 &&
1704 fib_metrics_match(cfg, fi)) {
1705 fa_to_delete = fa;
1706 break;
1707 }
1708 }
1709
1710 if (!fa_to_delete)
1711 return -ESRCH;
1712
1713 fib_notify_alias_delete(net, key, &l->leaf, fa_to_delete, extack);
1714 rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id,
1715 &cfg->fc_nlinfo, 0);
1716
1717 if (!plen)
1718 tb->tb_num_default--;
1719
1720 fib_remove_alias(t, tp, l, fa_to_delete);
1721
1722 if (fa_to_delete->fa_state & FA_S_ACCESSED)
1723 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1724
1725 fib_release_info(fa_to_delete->fa_info);
1726 alias_free_mem_rcu(fa_to_delete);
1727 return 0;
1728}
1729
1730/* Scan for the next leaf starting at the provided key value */
1731static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key)
1732{
1733 struct key_vector *pn, *n = *tn;
1734 unsigned long cindex;
1735
1736 /* this loop is meant to try and find the key in the trie */
1737 do {
1738 /* record parent and next child index */
1739 pn = n;
1740 cindex = (key > pn->key) ? get_index(key, pn) : 0;
1741
1742 if (cindex >> pn->bits)
1743 break;
1744
1745 /* descend into the next child */
1746 n = get_child_rcu(pn, cindex++);
1747 if (!n)
1748 break;
1749
1750 /* guarantee forward progress on the keys */
1751 if (IS_LEAF(n) && (n->key >= key))
1752 goto found;
1753 } while (IS_TNODE(n));
1754
1755 /* this loop will search for the next leaf with a greater key */
1756 while (!IS_TRIE(pn)) {
1757 /* if we exhausted the parent node we will need to climb */
1758 if (cindex >= (1ul << pn->bits)) {
1759 t_key pkey = pn->key;
1760
1761 pn = node_parent_rcu(pn);
1762 cindex = get_index(pkey, pn) + 1;
1763 continue;
1764 }
1765
1766 /* grab the next available node */
1767 n = get_child_rcu(pn, cindex++);
1768 if (!n)
1769 continue;
1770
1771 /* no need to compare keys since we bumped the index */
1772 if (IS_LEAF(n))
1773 goto found;
1774
1775 /* Rescan start scanning in new node */
1776 pn = n;
1777 cindex = 0;
1778 }
1779
1780 *tn = pn;
1781 return NULL; /* Root of trie */
1782found:
1783 /* if we are at the limit for keys just return NULL for the tnode */
1784 *tn = pn;
1785 return n;
1786}
1787
1788static void fib_trie_free(struct fib_table *tb)
1789{
1790 struct trie *t = (struct trie *)tb->tb_data;
1791 struct key_vector *pn = t->kv;
1792 unsigned long cindex = 1;
1793 struct hlist_node *tmp;
1794 struct fib_alias *fa;
1795
1796 /* walk trie in reverse order and free everything */
1797 for (;;) {
1798 struct key_vector *n;
1799
1800 if (!(cindex--)) {
1801 t_key pkey = pn->key;
1802
1803 if (IS_TRIE(pn))
1804 break;
1805
1806 n = pn;
1807 pn = node_parent(pn);
1808
1809 /* drop emptied tnode */
1810 put_child_root(pn, n->key, NULL);
1811 node_free(n);
1812
1813 cindex = get_index(pkey, pn);
1814
1815 continue;
1816 }
1817
1818 /* grab the next available node */
1819 n = get_child(pn, cindex);
1820 if (!n)
1821 continue;
1822
1823 if (IS_TNODE(n)) {
1824 /* record pn and cindex for leaf walking */
1825 pn = n;
1826 cindex = 1ul << n->bits;
1827
1828 continue;
1829 }
1830
1831 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1832 hlist_del_rcu(&fa->fa_list);
1833 alias_free_mem_rcu(fa);
1834 }
1835
1836 put_child_root(pn, n->key, NULL);
1837 node_free(n);
1838 }
1839
1840#ifdef CONFIG_IP_FIB_TRIE_STATS
1841 free_percpu(t->stats);
1842#endif
1843 kfree(tb);
1844}
1845
1846struct fib_table *fib_trie_unmerge(struct fib_table *oldtb)
1847{
1848 struct trie *ot = (struct trie *)oldtb->tb_data;
1849 struct key_vector *l, *tp = ot->kv;
1850 struct fib_table *local_tb;
1851 struct fib_alias *fa;
1852 struct trie *lt;
1853 t_key key = 0;
1854
1855 if (oldtb->tb_data == oldtb->__data)
1856 return oldtb;
1857
1858 local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL);
1859 if (!local_tb)
1860 return NULL;
1861
1862 lt = (struct trie *)local_tb->tb_data;
1863
1864 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
1865 struct key_vector *local_l = NULL, *local_tp;
1866
1867 hlist_for_each_entry(fa, &l->leaf, fa_list) {
1868 struct fib_alias *new_fa;
1869
1870 if (local_tb->tb_id != fa->tb_id)
1871 continue;
1872
1873 /* clone fa for new local table */
1874 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1875 if (!new_fa)
1876 goto out;
1877
1878 memcpy(new_fa, fa, sizeof(*fa));
1879
1880 /* insert clone into table */
1881 if (!local_l)
1882 local_l = fib_find_node(lt, &local_tp, l->key);
1883
1884 if (fib_insert_alias(lt, local_tp, local_l, new_fa,
1885 NULL, l->key)) {
1886 kmem_cache_free(fn_alias_kmem, new_fa);
1887 goto out;
1888 }
1889 }
1890
1891 /* stop loop if key wrapped back to 0 */
1892 key = l->key + 1;
1893 if (key < l->key)
1894 break;
1895 }
1896
1897 return local_tb;
1898out:
1899 fib_trie_free(local_tb);
1900
1901 return NULL;
1902}
1903
1904/* Caller must hold RTNL */
1905void fib_table_flush_external(struct fib_table *tb)
1906{
1907 struct trie *t = (struct trie *)tb->tb_data;
1908 struct key_vector *pn = t->kv;
1909 unsigned long cindex = 1;
1910 struct hlist_node *tmp;
1911 struct fib_alias *fa;
1912
1913 /* walk trie in reverse order */
1914 for (;;) {
1915 unsigned char slen = 0;
1916 struct key_vector *n;
1917
1918 if (!(cindex--)) {
1919 t_key pkey = pn->key;
1920
1921 /* cannot resize the trie vector */
1922 if (IS_TRIE(pn))
1923 break;
1924
1925 /* update the suffix to address pulled leaves */
1926 if (pn->slen > pn->pos)
1927 update_suffix(pn);
1928
1929 /* resize completed node */
1930 pn = resize(t, pn);
1931 cindex = get_index(pkey, pn);
1932
1933 continue;
1934 }
1935
1936 /* grab the next available node */
1937 n = get_child(pn, cindex);
1938 if (!n)
1939 continue;
1940
1941 if (IS_TNODE(n)) {
1942 /* record pn and cindex for leaf walking */
1943 pn = n;
1944 cindex = 1ul << n->bits;
1945
1946 continue;
1947 }
1948
1949 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1950 /* if alias was cloned to local then we just
1951 * need to remove the local copy from main
1952 */
1953 if (tb->tb_id != fa->tb_id) {
1954 hlist_del_rcu(&fa->fa_list);
1955 alias_free_mem_rcu(fa);
1956 continue;
1957 }
1958
1959 /* record local slen */
1960 slen = fa->fa_slen;
1961 }
1962
1963 /* update leaf slen */
1964 n->slen = slen;
1965
1966 if (hlist_empty(&n->leaf)) {
1967 put_child_root(pn, n->key, NULL);
1968 node_free(n);
1969 }
1970 }
1971}
1972
1973/* Caller must hold RTNL. */
1974int fib_table_flush(struct net *net, struct fib_table *tb, bool flush_all)
1975{
1976 struct trie *t = (struct trie *)tb->tb_data;
1977 struct key_vector *pn = t->kv;
1978 unsigned long cindex = 1;
1979 struct hlist_node *tmp;
1980 struct fib_alias *fa;
1981 int found = 0;
1982
1983 /* walk trie in reverse order */
1984 for (;;) {
1985 unsigned char slen = 0;
1986 struct key_vector *n;
1987
1988 if (!(cindex--)) {
1989 t_key pkey = pn->key;
1990
1991 /* cannot resize the trie vector */
1992 if (IS_TRIE(pn))
1993 break;
1994
1995 /* update the suffix to address pulled leaves */
1996 if (pn->slen > pn->pos)
1997 update_suffix(pn);
1998
1999 /* resize completed node */
2000 pn = resize(t, pn);
2001 cindex = get_index(pkey, pn);
2002
2003 continue;
2004 }
2005
2006 /* grab the next available node */
2007 n = get_child(pn, cindex);
2008 if (!n)
2009 continue;
2010
2011 if (IS_TNODE(n)) {
2012 /* record pn and cindex for leaf walking */
2013 pn = n;
2014 cindex = 1ul << n->bits;
2015
2016 continue;
2017 }
2018
2019 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
2020 struct fib_info *fi = fa->fa_info;
2021
2022 if (!fi || tb->tb_id != fa->tb_id ||
2023 (!(fi->fib_flags & RTNH_F_DEAD) &&
2024 !fib_props[fa->fa_type].error)) {
2025 slen = fa->fa_slen;
2026 continue;
2027 }
2028
2029 /* Do not flush error routes if network namespace is
2030 * not being dismantled
2031 */
2032 if (!flush_all && fib_props[fa->fa_type].error) {
2033 slen = fa->fa_slen;
2034 continue;
2035 }
2036
2037 fib_notify_alias_delete(net, n->key, &n->leaf, fa,
2038 NULL);
2039 hlist_del_rcu(&fa->fa_list);
2040 fib_release_info(fa->fa_info);
2041 alias_free_mem_rcu(fa);
2042 found++;
2043 }
2044
2045 /* update leaf slen */
2046 n->slen = slen;
2047
2048 if (hlist_empty(&n->leaf)) {
2049 put_child_root(pn, n->key, NULL);
2050 node_free(n);
2051 }
2052 }
2053
2054 pr_debug("trie_flush found=%d\n", found);
2055 return found;
2056}
2057
2058/* derived from fib_trie_free */
2059static void __fib_info_notify_update(struct net *net, struct fib_table *tb,
2060 struct nl_info *info)
2061{
2062 struct trie *t = (struct trie *)tb->tb_data;
2063 struct key_vector *pn = t->kv;
2064 unsigned long cindex = 1;
2065 struct fib_alias *fa;
2066
2067 for (;;) {
2068 struct key_vector *n;
2069
2070 if (!(cindex--)) {
2071 t_key pkey = pn->key;
2072
2073 if (IS_TRIE(pn))
2074 break;
2075
2076 pn = node_parent(pn);
2077 cindex = get_index(pkey, pn);
2078 continue;
2079 }
2080
2081 /* grab the next available node */
2082 n = get_child(pn, cindex);
2083 if (!n)
2084 continue;
2085
2086 if (IS_TNODE(n)) {
2087 /* record pn and cindex for leaf walking */
2088 pn = n;
2089 cindex = 1ul << n->bits;
2090
2091 continue;
2092 }
2093
2094 hlist_for_each_entry(fa, &n->leaf, fa_list) {
2095 struct fib_info *fi = fa->fa_info;
2096
2097 if (!fi || !fi->nh_updated || fa->tb_id != tb->tb_id)
2098 continue;
2099
2100 rtmsg_fib(RTM_NEWROUTE, htonl(n->key), fa,
2101 KEYLENGTH - fa->fa_slen, tb->tb_id,
2102 info, NLM_F_REPLACE);
2103
2104 /* call_fib_entry_notifiers will be removed when
2105 * in-kernel notifier is implemented and supported
2106 * for nexthop objects
2107 */
2108 call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE,
2109 n->key,
2110 KEYLENGTH - fa->fa_slen, fa,
2111 NULL);
2112 }
2113 }
2114}
2115
2116void fib_info_notify_update(struct net *net, struct nl_info *info)
2117{
2118 unsigned int h;
2119
2120 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2121 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2122 struct fib_table *tb;
2123
2124 hlist_for_each_entry_rcu(tb, head, tb_hlist,
2125 lockdep_rtnl_is_held())
2126 __fib_info_notify_update(net, tb, info);
2127 }
2128}
2129
2130static int fib_leaf_notify(struct key_vector *l, struct fib_table *tb,
2131 struct notifier_block *nb,
2132 struct netlink_ext_ack *extack)
2133{
2134 struct fib_alias *fa;
2135 int last_slen = -1;
2136 int err;
2137
2138 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2139 struct fib_info *fi = fa->fa_info;
2140
2141 if (!fi)
2142 continue;
2143
2144 /* local and main table can share the same trie,
2145 * so don't notify twice for the same entry.
2146 */
2147 if (tb->tb_id != fa->tb_id)
2148 continue;
2149
2150 if (fa->fa_slen == last_slen)
2151 continue;
2152
2153 last_slen = fa->fa_slen;
2154 err = call_fib_entry_notifier(nb, FIB_EVENT_ENTRY_REPLACE,
2155 l->key, KEYLENGTH - fa->fa_slen,
2156 fa, extack);
2157 if (err)
2158 return err;
2159 }
2160 return 0;
2161}
2162
2163static int fib_table_notify(struct fib_table *tb, struct notifier_block *nb,
2164 struct netlink_ext_ack *extack)
2165{
2166 struct trie *t = (struct trie *)tb->tb_data;
2167 struct key_vector *l, *tp = t->kv;
2168 t_key key = 0;
2169 int err;
2170
2171 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
2172 err = fib_leaf_notify(l, tb, nb, extack);
2173 if (err)
2174 return err;
2175
2176 key = l->key + 1;
2177 /* stop in case of wrap around */
2178 if (key < l->key)
2179 break;
2180 }
2181 return 0;
2182}
2183
2184int fib_notify(struct net *net, struct notifier_block *nb,
2185 struct netlink_ext_ack *extack)
2186{
2187 unsigned int h;
2188 int err;
2189
2190 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2191 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2192 struct fib_table *tb;
2193
2194 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2195 err = fib_table_notify(tb, nb, extack);
2196 if (err)
2197 return err;
2198 }
2199 }
2200 return 0;
2201}
2202
2203static void __trie_free_rcu(struct rcu_head *head)
2204{
2205 struct fib_table *tb = container_of(head, struct fib_table, rcu);
2206#ifdef CONFIG_IP_FIB_TRIE_STATS
2207 struct trie *t = (struct trie *)tb->tb_data;
2208
2209 if (tb->tb_data == tb->__data)
2210 free_percpu(t->stats);
2211#endif /* CONFIG_IP_FIB_TRIE_STATS */
2212 kfree(tb);
2213}
2214
2215void fib_free_table(struct fib_table *tb)
2216{
2217 call_rcu(&tb->rcu, __trie_free_rcu);
2218}
2219
2220static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb,
2221 struct sk_buff *skb, struct netlink_callback *cb,
2222 struct fib_dump_filter *filter)
2223{
2224 unsigned int flags = NLM_F_MULTI;
2225 __be32 xkey = htonl(l->key);
2226 int i, s_i, i_fa, s_fa, err;
2227 struct fib_alias *fa;
2228
2229 if (filter->filter_set ||
2230 !filter->dump_exceptions || !filter->dump_routes)
2231 flags |= NLM_F_DUMP_FILTERED;
2232
2233 s_i = cb->args[4];
2234 s_fa = cb->args[5];
2235 i = 0;
2236
2237 /* rcu_read_lock is hold by caller */
2238 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2239 struct fib_info *fi = fa->fa_info;
2240
2241 if (i < s_i)
2242 goto next;
2243
2244 i_fa = 0;
2245
2246 if (tb->tb_id != fa->tb_id)
2247 goto next;
2248
2249 if (filter->filter_set) {
2250 if (filter->rt_type && fa->fa_type != filter->rt_type)
2251 goto next;
2252
2253 if ((filter->protocol &&
2254 fi->fib_protocol != filter->protocol))
2255 goto next;
2256
2257 if (filter->dev &&
2258 !fib_info_nh_uses_dev(fi, filter->dev))
2259 goto next;
2260 }
2261
2262 if (filter->dump_routes) {
2263 if (!s_fa) {
2264 struct fib_rt_info fri;
2265
2266 fri.fi = fi;
2267 fri.tb_id = tb->tb_id;
2268 fri.dst = xkey;
2269 fri.dst_len = KEYLENGTH - fa->fa_slen;
2270 fri.tos = fa->fa_tos;
2271 fri.type = fa->fa_type;
2272 fri.offload = fa->offload;
2273 fri.trap = fa->trap;
2274 err = fib_dump_info(skb,
2275 NETLINK_CB(cb->skb).portid,
2276 cb->nlh->nlmsg_seq,
2277 RTM_NEWROUTE, &fri, flags);
2278 if (err < 0)
2279 goto stop;
2280 }
2281
2282 i_fa++;
2283 }
2284
2285 if (filter->dump_exceptions) {
2286 err = fib_dump_info_fnhe(skb, cb, tb->tb_id, fi,
2287 &i_fa, s_fa, flags);
2288 if (err < 0)
2289 goto stop;
2290 }
2291
2292next:
2293 i++;
2294 }
2295
2296 cb->args[4] = i;
2297 return skb->len;
2298
2299stop:
2300 cb->args[4] = i;
2301 cb->args[5] = i_fa;
2302 return err;
2303}
2304
2305/* rcu_read_lock needs to be hold by caller from readside */
2306int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
2307 struct netlink_callback *cb, struct fib_dump_filter *filter)
2308{
2309 struct trie *t = (struct trie *)tb->tb_data;
2310 struct key_vector *l, *tp = t->kv;
2311 /* Dump starting at last key.
2312 * Note: 0.0.0.0/0 (ie default) is first key.
2313 */
2314 int count = cb->args[2];
2315 t_key key = cb->args[3];
2316
2317 /* First time here, count and key are both always 0. Count > 0
2318 * and key == 0 means the dump has wrapped around and we are done.
2319 */
2320 if (count && !key)
2321 return skb->len;
2322
2323 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
2324 int err;
2325
2326 err = fn_trie_dump_leaf(l, tb, skb, cb, filter);
2327 if (err < 0) {
2328 cb->args[3] = key;
2329 cb->args[2] = count;
2330 return err;
2331 }
2332
2333 ++count;
2334 key = l->key + 1;
2335
2336 memset(&cb->args[4], 0,
2337 sizeof(cb->args) - 4*sizeof(cb->args[0]));
2338
2339 /* stop loop if key wrapped back to 0 */
2340 if (key < l->key)
2341 break;
2342 }
2343
2344 cb->args[3] = key;
2345 cb->args[2] = count;
2346
2347 return skb->len;
2348}
2349
2350void __init fib_trie_init(void)
2351{
2352 fn_alias_kmem = kmem_cache_create("ip_fib_alias",
2353 sizeof(struct fib_alias),
2354 0, SLAB_PANIC, NULL);
2355
2356 trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
2357 LEAF_SIZE,
2358 0, SLAB_PANIC, NULL);
2359}
2360
2361struct fib_table *fib_trie_table(u32 id, struct fib_table *alias)
2362{
2363 struct fib_table *tb;
2364 struct trie *t;
2365 size_t sz = sizeof(*tb);
2366
2367 if (!alias)
2368 sz += sizeof(struct trie);
2369
2370 tb = kzalloc(sz, GFP_KERNEL);
2371 if (!tb)
2372 return NULL;
2373
2374 tb->tb_id = id;
2375 tb->tb_num_default = 0;
2376 tb->tb_data = (alias ? alias->__data : tb->__data);
2377
2378 if (alias)
2379 return tb;
2380
2381 t = (struct trie *) tb->tb_data;
2382 t->kv[0].pos = KEYLENGTH;
2383 t->kv[0].slen = KEYLENGTH;
2384#ifdef CONFIG_IP_FIB_TRIE_STATS
2385 t->stats = alloc_percpu(struct trie_use_stats);
2386 if (!t->stats) {
2387 kfree(tb);
2388 tb = NULL;
2389 }
2390#endif
2391
2392 return tb;
2393}
2394
2395#ifdef CONFIG_PROC_FS
2396/* Depth first Trie walk iterator */
2397struct fib_trie_iter {
2398 struct seq_net_private p;
2399 struct fib_table *tb;
2400 struct key_vector *tnode;
2401 unsigned int index;
2402 unsigned int depth;
2403};
2404
2405static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter)
2406{
2407 unsigned long cindex = iter->index;
2408 struct key_vector *pn = iter->tnode;
2409 t_key pkey;
2410
2411 pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
2412 iter->tnode, iter->index, iter->depth);
2413
2414 while (!IS_TRIE(pn)) {
2415 while (cindex < child_length(pn)) {
2416 struct key_vector *n = get_child_rcu(pn, cindex++);
2417
2418 if (!n)
2419 continue;
2420
2421 if (IS_LEAF(n)) {
2422 iter->tnode = pn;
2423 iter->index = cindex;
2424 } else {
2425 /* push down one level */
2426 iter->tnode = n;
2427 iter->index = 0;
2428 ++iter->depth;
2429 }
2430
2431 return n;
2432 }
2433
2434 /* Current node exhausted, pop back up */
2435 pkey = pn->key;
2436 pn = node_parent_rcu(pn);
2437 cindex = get_index(pkey, pn) + 1;
2438 --iter->depth;
2439 }
2440
2441 /* record root node so further searches know we are done */
2442 iter->tnode = pn;
2443 iter->index = 0;
2444
2445 return NULL;
2446}
2447
2448static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter,
2449 struct trie *t)
2450{
2451 struct key_vector *n, *pn;
2452
2453 if (!t)
2454 return NULL;
2455
2456 pn = t->kv;
2457 n = rcu_dereference(pn->tnode[0]);
2458 if (!n)
2459 return NULL;
2460
2461 if (IS_TNODE(n)) {
2462 iter->tnode = n;
2463 iter->index = 0;
2464 iter->depth = 1;
2465 } else {
2466 iter->tnode = pn;
2467 iter->index = 0;
2468 iter->depth = 0;
2469 }
2470
2471 return n;
2472}
2473
2474static void trie_collect_stats(struct trie *t, struct trie_stat *s)
2475{
2476 struct key_vector *n;
2477 struct fib_trie_iter iter;
2478
2479 memset(s, 0, sizeof(*s));
2480
2481 rcu_read_lock();
2482 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) {
2483 if (IS_LEAF(n)) {
2484 struct fib_alias *fa;
2485
2486 s->leaves++;
2487 s->totdepth += iter.depth;
2488 if (iter.depth > s->maxdepth)
2489 s->maxdepth = iter.depth;
2490
2491 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list)
2492 ++s->prefixes;
2493 } else {
2494 s->tnodes++;
2495 if (n->bits < MAX_STAT_DEPTH)
2496 s->nodesizes[n->bits]++;
2497 s->nullpointers += tn_info(n)->empty_children;
2498 }
2499 }
2500 rcu_read_unlock();
2501}
2502
2503/*
2504 * This outputs /proc/net/fib_triestats
2505 */
2506static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
2507{
2508 unsigned int i, max, pointers, bytes, avdepth;
2509
2510 if (stat->leaves)
2511 avdepth = stat->totdepth*100 / stat->leaves;
2512 else
2513 avdepth = 0;
2514
2515 seq_printf(seq, "\tAver depth: %u.%02d\n",
2516 avdepth / 100, avdepth % 100);
2517 seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth);
2518
2519 seq_printf(seq, "\tLeaves: %u\n", stat->leaves);
2520 bytes = LEAF_SIZE * stat->leaves;
2521
2522 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes);
2523 bytes += sizeof(struct fib_alias) * stat->prefixes;
2524
2525 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);
2526 bytes += TNODE_SIZE(0) * stat->tnodes;
2527
2528 max = MAX_STAT_DEPTH;
2529 while (max > 0 && stat->nodesizes[max-1] == 0)
2530 max--;
2531
2532 pointers = 0;
2533 for (i = 1; i < max; i++)
2534 if (stat->nodesizes[i] != 0) {
2535 seq_printf(seq, " %u: %u", i, stat->nodesizes[i]);
2536 pointers += (1<<i) * stat->nodesizes[i];
2537 }
2538 seq_putc(seq, '\n');
2539 seq_printf(seq, "\tPointers: %u\n", pointers);
2540
2541 bytes += sizeof(struct key_vector *) * pointers;
2542 seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers);
2543 seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024);
2544}
2545
2546#ifdef CONFIG_IP_FIB_TRIE_STATS
2547static void trie_show_usage(struct seq_file *seq,
2548 const struct trie_use_stats __percpu *stats)
2549{
2550 struct trie_use_stats s = { 0 };
2551 int cpu;
2552
2553 /* loop through all of the CPUs and gather up the stats */
2554 for_each_possible_cpu(cpu) {
2555 const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu);
2556
2557 s.gets += pcpu->gets;
2558 s.backtrack += pcpu->backtrack;
2559 s.semantic_match_passed += pcpu->semantic_match_passed;
2560 s.semantic_match_miss += pcpu->semantic_match_miss;
2561 s.null_node_hit += pcpu->null_node_hit;
2562 s.resize_node_skipped += pcpu->resize_node_skipped;
2563 }
2564
2565 seq_printf(seq, "\nCounters:\n---------\n");
2566 seq_printf(seq, "gets = %u\n", s.gets);
2567 seq_printf(seq, "backtracks = %u\n", s.backtrack);
2568 seq_printf(seq, "semantic match passed = %u\n",
2569 s.semantic_match_passed);
2570 seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss);
2571 seq_printf(seq, "null node hit= %u\n", s.null_node_hit);
2572 seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped);
2573}
2574#endif /* CONFIG_IP_FIB_TRIE_STATS */
2575
2576static void fib_table_print(struct seq_file *seq, struct fib_table *tb)
2577{
2578 if (tb->tb_id == RT_TABLE_LOCAL)
2579 seq_puts(seq, "Local:\n");
2580 else if (tb->tb_id == RT_TABLE_MAIN)
2581 seq_puts(seq, "Main:\n");
2582 else
2583 seq_printf(seq, "Id %d:\n", tb->tb_id);
2584}
2585
2586
2587static int fib_triestat_seq_show(struct seq_file *seq, void *v)
2588{
2589 struct net *net = (struct net *)seq->private;
2590 unsigned int h;
2591
2592 seq_printf(seq,
2593 "Basic info: size of leaf:"
2594 " %zd bytes, size of tnode: %zd bytes.\n",
2595 LEAF_SIZE, TNODE_SIZE(0));
2596
2597 rcu_read_lock();
2598 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2599 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2600 struct fib_table *tb;
2601
2602 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2603 struct trie *t = (struct trie *) tb->tb_data;
2604 struct trie_stat stat;
2605
2606 if (!t)
2607 continue;
2608
2609 fib_table_print(seq, tb);
2610
2611 trie_collect_stats(t, &stat);
2612 trie_show_stats(seq, &stat);
2613#ifdef CONFIG_IP_FIB_TRIE_STATS
2614 trie_show_usage(seq, t->stats);
2615#endif
2616 }
2617 cond_resched_rcu();
2618 }
2619 rcu_read_unlock();
2620
2621 return 0;
2622}
2623
2624static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos)
2625{
2626 struct fib_trie_iter *iter = seq->private;
2627 struct net *net = seq_file_net(seq);
2628 loff_t idx = 0;
2629 unsigned int h;
2630
2631 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2632 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2633 struct fib_table *tb;
2634
2635 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2636 struct key_vector *n;
2637
2638 for (n = fib_trie_get_first(iter,
2639 (struct trie *) tb->tb_data);
2640 n; n = fib_trie_get_next(iter))
2641 if (pos == idx++) {
2642 iter->tb = tb;
2643 return n;
2644 }
2645 }
2646 }
2647
2648 return NULL;
2649}
2650
2651static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
2652 __acquires(RCU)
2653{
2654 rcu_read_lock();
2655 return fib_trie_get_idx(seq, *pos);
2656}
2657
2658static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2659{
2660 struct fib_trie_iter *iter = seq->private;
2661 struct net *net = seq_file_net(seq);
2662 struct fib_table *tb = iter->tb;
2663 struct hlist_node *tb_node;
2664 unsigned int h;
2665 struct key_vector *n;
2666
2667 ++*pos;
2668 /* next node in same table */
2669 n = fib_trie_get_next(iter);
2670 if (n)
2671 return n;
2672
2673 /* walk rest of this hash chain */
2674 h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);
2675 while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) {
2676 tb = hlist_entry(tb_node, struct fib_table, tb_hlist);
2677 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2678 if (n)
2679 goto found;
2680 }
2681
2682 /* new hash chain */
2683 while (++h < FIB_TABLE_HASHSZ) {
2684 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2685 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2686 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2687 if (n)
2688 goto found;
2689 }
2690 }
2691 return NULL;
2692
2693found:
2694 iter->tb = tb;
2695 return n;
2696}
2697
2698static void fib_trie_seq_stop(struct seq_file *seq, void *v)
2699 __releases(RCU)
2700{
2701 rcu_read_unlock();
2702}
2703
2704static void seq_indent(struct seq_file *seq, int n)
2705{
2706 while (n-- > 0)
2707 seq_puts(seq, " ");
2708}
2709
2710static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
2711{
2712 switch (s) {
2713 case RT_SCOPE_UNIVERSE: return "universe";
2714 case RT_SCOPE_SITE: return "site";
2715 case RT_SCOPE_LINK: return "link";
2716 case RT_SCOPE_HOST: return "host";
2717 case RT_SCOPE_NOWHERE: return "nowhere";
2718 default:
2719 snprintf(buf, len, "scope=%d", s);
2720 return buf;
2721 }
2722}
2723
2724static const char *const rtn_type_names[__RTN_MAX] = {
2725 [RTN_UNSPEC] = "UNSPEC",
2726 [RTN_UNICAST] = "UNICAST",
2727 [RTN_LOCAL] = "LOCAL",
2728 [RTN_BROADCAST] = "BROADCAST",
2729 [RTN_ANYCAST] = "ANYCAST",
2730 [RTN_MULTICAST] = "MULTICAST",
2731 [RTN_BLACKHOLE] = "BLACKHOLE",
2732 [RTN_UNREACHABLE] = "UNREACHABLE",
2733 [RTN_PROHIBIT] = "PROHIBIT",
2734 [RTN_THROW] = "THROW",
2735 [RTN_NAT] = "NAT",
2736 [RTN_XRESOLVE] = "XRESOLVE",
2737};
2738
2739static inline const char *rtn_type(char *buf, size_t len, unsigned int t)
2740{
2741 if (t < __RTN_MAX && rtn_type_names[t])
2742 return rtn_type_names[t];
2743 snprintf(buf, len, "type %u", t);
2744 return buf;
2745}
2746
2747/* Pretty print the trie */
2748static int fib_trie_seq_show(struct seq_file *seq, void *v)
2749{
2750 const struct fib_trie_iter *iter = seq->private;
2751 struct key_vector *n = v;
2752
2753 if (IS_TRIE(node_parent_rcu(n)))
2754 fib_table_print(seq, iter->tb);
2755
2756 if (IS_TNODE(n)) {
2757 __be32 prf = htonl(n->key);
2758
2759 seq_indent(seq, iter->depth-1);
2760 seq_printf(seq, " +-- %pI4/%zu %u %u %u\n",
2761 &prf, KEYLENGTH - n->pos - n->bits, n->bits,
2762 tn_info(n)->full_children,
2763 tn_info(n)->empty_children);
2764 } else {
2765 __be32 val = htonl(n->key);
2766 struct fib_alias *fa;
2767
2768 seq_indent(seq, iter->depth);
2769 seq_printf(seq, " |-- %pI4\n", &val);
2770
2771 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
2772 char buf1[32], buf2[32];
2773
2774 seq_indent(seq, iter->depth + 1);
2775 seq_printf(seq, " /%zu %s %s",
2776 KEYLENGTH - fa->fa_slen,
2777 rtn_scope(buf1, sizeof(buf1),
2778 fa->fa_info->fib_scope),
2779 rtn_type(buf2, sizeof(buf2),
2780 fa->fa_type));
2781 if (fa->fa_tos)
2782 seq_printf(seq, " tos=%d", fa->fa_tos);
2783 seq_putc(seq, '\n');
2784 }
2785 }
2786
2787 return 0;
2788}
2789
2790static const struct seq_operations fib_trie_seq_ops = {
2791 .start = fib_trie_seq_start,
2792 .next = fib_trie_seq_next,
2793 .stop = fib_trie_seq_stop,
2794 .show = fib_trie_seq_show,
2795};
2796
2797struct fib_route_iter {
2798 struct seq_net_private p;
2799 struct fib_table *main_tb;
2800 struct key_vector *tnode;
2801 loff_t pos;
2802 t_key key;
2803};
2804
2805static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter,
2806 loff_t pos)
2807{
2808 struct key_vector *l, **tp = &iter->tnode;
2809 t_key key;
2810
2811 /* use cached location of previously found key */
2812 if (iter->pos > 0 && pos >= iter->pos) {
2813 key = iter->key;
2814 } else {
2815 iter->pos = 1;
2816 key = 0;
2817 }
2818
2819 pos -= iter->pos;
2820
2821 while ((l = leaf_walk_rcu(tp, key)) && (pos-- > 0)) {
2822 key = l->key + 1;
2823 iter->pos++;
2824 l = NULL;
2825
2826 /* handle unlikely case of a key wrap */
2827 if (!key)
2828 break;
2829 }
2830
2831 if (l)
2832 iter->key = l->key; /* remember it */
2833 else
2834 iter->pos = 0; /* forget it */
2835
2836 return l;
2837}
2838
2839static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos)
2840 __acquires(RCU)
2841{
2842 struct fib_route_iter *iter = seq->private;
2843 struct fib_table *tb;
2844 struct trie *t;
2845
2846 rcu_read_lock();
2847
2848 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
2849 if (!tb)
2850 return NULL;
2851
2852 iter->main_tb = tb;
2853 t = (struct trie *)tb->tb_data;
2854 iter->tnode = t->kv;
2855
2856 if (*pos != 0)
2857 return fib_route_get_idx(iter, *pos);
2858
2859 iter->pos = 0;
2860 iter->key = KEY_MAX;
2861
2862 return SEQ_START_TOKEN;
2863}
2864
2865static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2866{
2867 struct fib_route_iter *iter = seq->private;
2868 struct key_vector *l = NULL;
2869 t_key key = iter->key + 1;
2870
2871 ++*pos;
2872
2873 /* only allow key of 0 for start of sequence */
2874 if ((v == SEQ_START_TOKEN) || key)
2875 l = leaf_walk_rcu(&iter->tnode, key);
2876
2877 if (l) {
2878 iter->key = l->key;
2879 iter->pos++;
2880 } else {
2881 iter->pos = 0;
2882 }
2883
2884 return l;
2885}
2886
2887static void fib_route_seq_stop(struct seq_file *seq, void *v)
2888 __releases(RCU)
2889{
2890 rcu_read_unlock();
2891}
2892
2893static unsigned int fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
2894{
2895 unsigned int flags = 0;
2896
2897 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT)
2898 flags = RTF_REJECT;
2899 if (fi) {
2900 const struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
2901
2902 if (nhc->nhc_gw.ipv4)
2903 flags |= RTF_GATEWAY;
2904 }
2905 if (mask == htonl(0xFFFFFFFF))
2906 flags |= RTF_HOST;
2907 flags |= RTF_UP;
2908 return flags;
2909}
2910
2911/*
2912 * This outputs /proc/net/route.
2913 * The format of the file is not supposed to be changed
2914 * and needs to be same as fib_hash output to avoid breaking
2915 * legacy utilities
2916 */
2917static int fib_route_seq_show(struct seq_file *seq, void *v)
2918{
2919 struct fib_route_iter *iter = seq->private;
2920 struct fib_table *tb = iter->main_tb;
2921 struct fib_alias *fa;
2922 struct key_vector *l = v;
2923 __be32 prefix;
2924
2925 if (v == SEQ_START_TOKEN) {
2926 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
2927 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
2928 "\tWindow\tIRTT");
2929 return 0;
2930 }
2931
2932 prefix = htonl(l->key);
2933
2934 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2935 struct fib_info *fi = fa->fa_info;
2936 __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen);
2937 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);
2938
2939 if ((fa->fa_type == RTN_BROADCAST) ||
2940 (fa->fa_type == RTN_MULTICAST))
2941 continue;
2942
2943 if (fa->tb_id != tb->tb_id)
2944 continue;
2945
2946 seq_setwidth(seq, 127);
2947
2948 if (fi) {
2949 struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
2950 __be32 gw = 0;
2951
2952 if (nhc->nhc_gw_family == AF_INET)
2953 gw = nhc->nhc_gw.ipv4;
2954
2955 seq_printf(seq,
2956 "%s\t%08X\t%08X\t%04X\t%d\t%u\t"
2957 "%d\t%08X\t%d\t%u\t%u",
2958 nhc->nhc_dev ? nhc->nhc_dev->name : "*",
2959 prefix, gw, flags, 0, 0,
2960 fi->fib_priority,
2961 mask,
2962 (fi->fib_advmss ?
2963 fi->fib_advmss + 40 : 0),
2964 fi->fib_window,
2965 fi->fib_rtt >> 3);
2966 } else {
2967 seq_printf(seq,
2968 "*\t%08X\t%08X\t%04X\t%d\t%u\t"
2969 "%d\t%08X\t%d\t%u\t%u",
2970 prefix, 0, flags, 0, 0, 0,
2971 mask, 0, 0, 0);
2972 }
2973 seq_pad(seq, '\n');
2974 }
2975
2976 return 0;
2977}
2978
2979static const struct seq_operations fib_route_seq_ops = {
2980 .start = fib_route_seq_start,
2981 .next = fib_route_seq_next,
2982 .stop = fib_route_seq_stop,
2983 .show = fib_route_seq_show,
2984};
2985
2986int __net_init fib_proc_init(struct net *net)
2987{
2988 if (!proc_create_net("fib_trie", 0444, net->proc_net, &fib_trie_seq_ops,
2989 sizeof(struct fib_trie_iter)))
2990 goto out1;
2991
2992 if (!proc_create_net_single("fib_triestat", 0444, net->proc_net,
2993 fib_triestat_seq_show, NULL))
2994 goto out2;
2995
2996 if (!proc_create_net("route", 0444, net->proc_net, &fib_route_seq_ops,
2997 sizeof(struct fib_route_iter)))
2998 goto out3;
2999
3000 return 0;
3001
3002out3:
3003 remove_proc_entry("fib_triestat", net->proc_net);
3004out2:
3005 remove_proc_entry("fib_trie", net->proc_net);
3006out1:
3007 return -ENOMEM;
3008}
3009
3010void __net_exit fib_proc_exit(struct net *net)
3011{
3012 remove_proc_entry("fib_trie", net->proc_net);
3013 remove_proc_entry("fib_triestat", net->proc_net);
3014 remove_proc_entry("route", net->proc_net);
3015}
3016
3017#endif /* CONFIG_PROC_FS */
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 * https://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#include <linux/cache.h>
39#include <linux/uaccess.h>
40#include <linux/bitops.h>
41#include <linux/types.h>
42#include <linux/kernel.h>
43#include <linux/mm.h>
44#include <linux/string.h>
45#include <linux/socket.h>
46#include <linux/sockios.h>
47#include <linux/errno.h>
48#include <linux/in.h>
49#include <linux/inet.h>
50#include <linux/inetdevice.h>
51#include <linux/netdevice.h>
52#include <linux/if_arp.h>
53#include <linux/proc_fs.h>
54#include <linux/rcupdate.h>
55#include <linux/skbuff.h>
56#include <linux/netlink.h>
57#include <linux/init.h>
58#include <linux/list.h>
59#include <linux/slab.h>
60#include <linux/export.h>
61#include <linux/vmalloc.h>
62#include <linux/notifier.h>
63#include <net/net_namespace.h>
64#include <net/inet_dscp.h>
65#include <net/ip.h>
66#include <net/protocol.h>
67#include <net/route.h>
68#include <net/tcp.h>
69#include <net/sock.h>
70#include <net/ip_fib.h>
71#include <net/fib_notifier.h>
72#include <trace/events/fib.h>
73#include "fib_lookup.h"
74
75static int call_fib_entry_notifier(struct notifier_block *nb,
76 enum fib_event_type event_type, u32 dst,
77 int dst_len, struct fib_alias *fa,
78 struct netlink_ext_ack *extack)
79{
80 struct fib_entry_notifier_info info = {
81 .info.extack = extack,
82 .dst = dst,
83 .dst_len = dst_len,
84 .fi = fa->fa_info,
85 .dscp = fa->fa_dscp,
86 .type = fa->fa_type,
87 .tb_id = fa->tb_id,
88 };
89 return call_fib4_notifier(nb, 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 .dscp = fa->fa_dscp,
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 DECLARE_FLEX_ARRAY(struct key_vector __rcu *, tnode);
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_VMALLOC_MAX \
306 ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *))
307
308static void __node_free_rcu(struct rcu_head *head)
309{
310 struct tnode *n = container_of(head, struct tnode, rcu);
311
312 if (!n->tn_bits)
313 kmem_cache_free(trie_leaf_kmem, n);
314 else
315 kvfree(n);
316}
317
318#define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu)
319
320static struct tnode *tnode_alloc(int bits)
321{
322 size_t size;
323
324 /* verify bits is within bounds */
325 if (bits > TNODE_VMALLOC_MAX)
326 return NULL;
327
328 /* determine size and verify it is non-zero and didn't overflow */
329 size = TNODE_SIZE(1ul << bits);
330
331 if (size <= PAGE_SIZE)
332 return kzalloc(size, GFP_KERNEL);
333 else
334 return vzalloc(size);
335}
336
337static inline void empty_child_inc(struct key_vector *n)
338{
339 tn_info(n)->empty_children++;
340
341 if (!tn_info(n)->empty_children)
342 tn_info(n)->full_children++;
343}
344
345static inline void empty_child_dec(struct key_vector *n)
346{
347 if (!tn_info(n)->empty_children)
348 tn_info(n)->full_children--;
349
350 tn_info(n)->empty_children--;
351}
352
353static struct key_vector *leaf_new(t_key key, struct fib_alias *fa)
354{
355 struct key_vector *l;
356 struct tnode *kv;
357
358 kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
359 if (!kv)
360 return NULL;
361
362 /* initialize key vector */
363 l = kv->kv;
364 l->key = key;
365 l->pos = 0;
366 l->bits = 0;
367 l->slen = fa->fa_slen;
368
369 /* link leaf to fib alias */
370 INIT_HLIST_HEAD(&l->leaf);
371 hlist_add_head(&fa->fa_list, &l->leaf);
372
373 return l;
374}
375
376static struct key_vector *tnode_new(t_key key, int pos, int bits)
377{
378 unsigned int shift = pos + bits;
379 struct key_vector *tn;
380 struct tnode *tnode;
381
382 /* verify bits and pos their msb bits clear and values are valid */
383 BUG_ON(!bits || (shift > KEYLENGTH));
384
385 tnode = tnode_alloc(bits);
386 if (!tnode)
387 return NULL;
388
389 pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0),
390 sizeof(struct key_vector *) << bits);
391
392 if (bits == KEYLENGTH)
393 tnode->full_children = 1;
394 else
395 tnode->empty_children = 1ul << bits;
396
397 tn = tnode->kv;
398 tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
399 tn->pos = pos;
400 tn->bits = bits;
401 tn->slen = pos;
402
403 return tn;
404}
405
406/* Check whether a tnode 'n' is "full", i.e. it is an internal node
407 * and no bits are skipped. See discussion in dyntree paper p. 6
408 */
409static inline int tnode_full(struct key_vector *tn, struct key_vector *n)
410{
411 return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n);
412}
413
414/* Add a child at position i overwriting the old value.
415 * Update the value of full_children and empty_children.
416 */
417static void put_child(struct key_vector *tn, unsigned long i,
418 struct key_vector *n)
419{
420 struct key_vector *chi = get_child(tn, i);
421 int isfull, wasfull;
422
423 BUG_ON(i >= child_length(tn));
424
425 /* update emptyChildren, overflow into fullChildren */
426 if (!n && chi)
427 empty_child_inc(tn);
428 if (n && !chi)
429 empty_child_dec(tn);
430
431 /* update fullChildren */
432 wasfull = tnode_full(tn, chi);
433 isfull = tnode_full(tn, n);
434
435 if (wasfull && !isfull)
436 tn_info(tn)->full_children--;
437 else if (!wasfull && isfull)
438 tn_info(tn)->full_children++;
439
440 if (n && (tn->slen < n->slen))
441 tn->slen = n->slen;
442
443 rcu_assign_pointer(tn->tnode[i], n);
444}
445
446static void update_children(struct key_vector *tn)
447{
448 unsigned long i;
449
450 /* update all of the child parent pointers */
451 for (i = child_length(tn); i;) {
452 struct key_vector *inode = get_child(tn, --i);
453
454 if (!inode)
455 continue;
456
457 /* Either update the children of a tnode that
458 * already belongs to us or update the child
459 * to point to ourselves.
460 */
461 if (node_parent(inode) == tn)
462 update_children(inode);
463 else
464 node_set_parent(inode, tn);
465 }
466}
467
468static inline void put_child_root(struct key_vector *tp, t_key key,
469 struct key_vector *n)
470{
471 if (IS_TRIE(tp))
472 rcu_assign_pointer(tp->tnode[0], n);
473 else
474 put_child(tp, get_index(key, tp), n);
475}
476
477static inline void tnode_free_init(struct key_vector *tn)
478{
479 tn_info(tn)->rcu.next = NULL;
480}
481
482static inline void tnode_free_append(struct key_vector *tn,
483 struct key_vector *n)
484{
485 tn_info(n)->rcu.next = tn_info(tn)->rcu.next;
486 tn_info(tn)->rcu.next = &tn_info(n)->rcu;
487}
488
489static void tnode_free(struct key_vector *tn)
490{
491 struct callback_head *head = &tn_info(tn)->rcu;
492
493 while (head) {
494 head = head->next;
495 tnode_free_size += TNODE_SIZE(1ul << tn->bits);
496 node_free(tn);
497
498 tn = container_of(head, struct tnode, rcu)->kv;
499 }
500
501 if (tnode_free_size >= READ_ONCE(sysctl_fib_sync_mem)) {
502 tnode_free_size = 0;
503 synchronize_rcu();
504 }
505}
506
507static struct key_vector *replace(struct trie *t,
508 struct key_vector *oldtnode,
509 struct key_vector *tn)
510{
511 struct key_vector *tp = node_parent(oldtnode);
512 unsigned long i;
513
514 /* setup the parent pointer out of and back into this node */
515 NODE_INIT_PARENT(tn, tp);
516 put_child_root(tp, tn->key, tn);
517
518 /* update all of the child parent pointers */
519 update_children(tn);
520
521 /* all pointers should be clean so we are done */
522 tnode_free(oldtnode);
523
524 /* resize children now that oldtnode is freed */
525 for (i = child_length(tn); i;) {
526 struct key_vector *inode = get_child(tn, --i);
527
528 /* resize child node */
529 if (tnode_full(tn, inode))
530 tn = resize(t, inode);
531 }
532
533 return tp;
534}
535
536static struct key_vector *inflate(struct trie *t,
537 struct key_vector *oldtnode)
538{
539 struct key_vector *tn;
540 unsigned long i;
541 t_key m;
542
543 pr_debug("In inflate\n");
544
545 tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1);
546 if (!tn)
547 goto notnode;
548
549 /* prepare oldtnode to be freed */
550 tnode_free_init(oldtnode);
551
552 /* Assemble all of the pointers in our cluster, in this case that
553 * represents all of the pointers out of our allocated nodes that
554 * point to existing tnodes and the links between our allocated
555 * nodes.
556 */
557 for (i = child_length(oldtnode), m = 1u << tn->pos; i;) {
558 struct key_vector *inode = get_child(oldtnode, --i);
559 struct key_vector *node0, *node1;
560 unsigned long j, k;
561
562 /* An empty child */
563 if (!inode)
564 continue;
565
566 /* A leaf or an internal node with skipped bits */
567 if (!tnode_full(oldtnode, inode)) {
568 put_child(tn, get_index(inode->key, tn), inode);
569 continue;
570 }
571
572 /* drop the node in the old tnode free list */
573 tnode_free_append(oldtnode, inode);
574
575 /* An internal node with two children */
576 if (inode->bits == 1) {
577 put_child(tn, 2 * i + 1, get_child(inode, 1));
578 put_child(tn, 2 * i, get_child(inode, 0));
579 continue;
580 }
581
582 /* We will replace this node 'inode' with two new
583 * ones, 'node0' and 'node1', each with half of the
584 * original children. The two new nodes will have
585 * a position one bit further down the key and this
586 * means that the "significant" part of their keys
587 * (see the discussion near the top of this file)
588 * will differ by one bit, which will be "0" in
589 * node0's key and "1" in node1's key. Since we are
590 * moving the key position by one step, the bit that
591 * we are moving away from - the bit at position
592 * (tn->pos) - is the one that will differ between
593 * node0 and node1. So... we synthesize that bit in the
594 * two new keys.
595 */
596 node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1);
597 if (!node1)
598 goto nomem;
599 node0 = tnode_new(inode->key, inode->pos, inode->bits - 1);
600
601 tnode_free_append(tn, node1);
602 if (!node0)
603 goto nomem;
604 tnode_free_append(tn, node0);
605
606 /* populate child pointers in new nodes */
607 for (k = child_length(inode), j = k / 2; j;) {
608 put_child(node1, --j, get_child(inode, --k));
609 put_child(node0, j, get_child(inode, j));
610 put_child(node1, --j, get_child(inode, --k));
611 put_child(node0, j, get_child(inode, j));
612 }
613
614 /* link new nodes to parent */
615 NODE_INIT_PARENT(node1, tn);
616 NODE_INIT_PARENT(node0, tn);
617
618 /* link parent to nodes */
619 put_child(tn, 2 * i + 1, node1);
620 put_child(tn, 2 * i, node0);
621 }
622
623 /* setup the parent pointers into and out of this node */
624 return replace(t, oldtnode, tn);
625nomem:
626 /* all pointers should be clean so we are done */
627 tnode_free(tn);
628notnode:
629 return NULL;
630}
631
632static struct key_vector *halve(struct trie *t,
633 struct key_vector *oldtnode)
634{
635 struct key_vector *tn;
636 unsigned long i;
637
638 pr_debug("In halve\n");
639
640 tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1);
641 if (!tn)
642 goto notnode;
643
644 /* prepare oldtnode to be freed */
645 tnode_free_init(oldtnode);
646
647 /* Assemble all of the pointers in our cluster, in this case that
648 * represents all of the pointers out of our allocated nodes that
649 * point to existing tnodes and the links between our allocated
650 * nodes.
651 */
652 for (i = child_length(oldtnode); i;) {
653 struct key_vector *node1 = get_child(oldtnode, --i);
654 struct key_vector *node0 = get_child(oldtnode, --i);
655 struct key_vector *inode;
656
657 /* At least one of the children is empty */
658 if (!node1 || !node0) {
659 put_child(tn, i / 2, node1 ? : node0);
660 continue;
661 }
662
663 /* Two nonempty children */
664 inode = tnode_new(node0->key, oldtnode->pos, 1);
665 if (!inode)
666 goto nomem;
667 tnode_free_append(tn, inode);
668
669 /* initialize pointers out of node */
670 put_child(inode, 1, node1);
671 put_child(inode, 0, node0);
672 NODE_INIT_PARENT(inode, tn);
673
674 /* link parent to node */
675 put_child(tn, i / 2, inode);
676 }
677
678 /* setup the parent pointers into and out of this node */
679 return replace(t, oldtnode, tn);
680nomem:
681 /* all pointers should be clean so we are done */
682 tnode_free(tn);
683notnode:
684 return NULL;
685}
686
687static struct key_vector *collapse(struct trie *t,
688 struct key_vector *oldtnode)
689{
690 struct key_vector *n, *tp;
691 unsigned long i;
692
693 /* scan the tnode looking for that one child that might still exist */
694 for (n = NULL, i = child_length(oldtnode); !n && i;)
695 n = get_child(oldtnode, --i);
696
697 /* compress one level */
698 tp = node_parent(oldtnode);
699 put_child_root(tp, oldtnode->key, n);
700 node_set_parent(n, tp);
701
702 /* drop dead node */
703 node_free(oldtnode);
704
705 return tp;
706}
707
708static unsigned char update_suffix(struct key_vector *tn)
709{
710 unsigned char slen = tn->pos;
711 unsigned long stride, i;
712 unsigned char slen_max;
713
714 /* only vector 0 can have a suffix length greater than or equal to
715 * tn->pos + tn->bits, the second highest node will have a suffix
716 * length at most of tn->pos + tn->bits - 1
717 */
718 slen_max = min_t(unsigned char, tn->pos + tn->bits - 1, tn->slen);
719
720 /* search though the list of children looking for nodes that might
721 * have a suffix greater than the one we currently have. This is
722 * why we start with a stride of 2 since a stride of 1 would
723 * represent the nodes with suffix length equal to tn->pos
724 */
725 for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) {
726 struct key_vector *n = get_child(tn, i);
727
728 if (!n || (n->slen <= slen))
729 continue;
730
731 /* update stride and slen based on new value */
732 stride <<= (n->slen - slen);
733 slen = n->slen;
734 i &= ~(stride - 1);
735
736 /* stop searching if we have hit the maximum possible value */
737 if (slen >= slen_max)
738 break;
739 }
740
741 tn->slen = slen;
742
743 return slen;
744}
745
746/* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
747 * the Helsinki University of Technology and Matti Tikkanen of Nokia
748 * Telecommunications, page 6:
749 * "A node is doubled if the ratio of non-empty children to all
750 * children in the *doubled* node is at least 'high'."
751 *
752 * 'high' in this instance is the variable 'inflate_threshold'. It
753 * is expressed as a percentage, so we multiply it with
754 * child_length() and instead of multiplying by 2 (since the
755 * child array will be doubled by inflate()) and multiplying
756 * the left-hand side by 100 (to handle the percentage thing) we
757 * multiply the left-hand side by 50.
758 *
759 * The left-hand side may look a bit weird: child_length(tn)
760 * - tn->empty_children is of course the number of non-null children
761 * in the current node. tn->full_children is the number of "full"
762 * children, that is non-null tnodes with a skip value of 0.
763 * All of those will be doubled in the resulting inflated tnode, so
764 * we just count them one extra time here.
765 *
766 * A clearer way to write this would be:
767 *
768 * to_be_doubled = tn->full_children;
769 * not_to_be_doubled = child_length(tn) - tn->empty_children -
770 * tn->full_children;
771 *
772 * new_child_length = child_length(tn) * 2;
773 *
774 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
775 * new_child_length;
776 * if (new_fill_factor >= inflate_threshold)
777 *
778 * ...and so on, tho it would mess up the while () loop.
779 *
780 * anyway,
781 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
782 * inflate_threshold
783 *
784 * avoid a division:
785 * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
786 * inflate_threshold * new_child_length
787 *
788 * expand not_to_be_doubled and to_be_doubled, and shorten:
789 * 100 * (child_length(tn) - tn->empty_children +
790 * tn->full_children) >= inflate_threshold * new_child_length
791 *
792 * expand new_child_length:
793 * 100 * (child_length(tn) - tn->empty_children +
794 * tn->full_children) >=
795 * inflate_threshold * child_length(tn) * 2
796 *
797 * shorten again:
798 * 50 * (tn->full_children + child_length(tn) -
799 * tn->empty_children) >= inflate_threshold *
800 * child_length(tn)
801 *
802 */
803static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn)
804{
805 unsigned long used = child_length(tn);
806 unsigned long threshold = used;
807
808 /* Keep root node larger */
809 threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold;
810 used -= tn_info(tn)->empty_children;
811 used += tn_info(tn)->full_children;
812
813 /* if bits == KEYLENGTH then pos = 0, and will fail below */
814
815 return (used > 1) && tn->pos && ((50 * used) >= threshold);
816}
817
818static inline bool should_halve(struct key_vector *tp, struct key_vector *tn)
819{
820 unsigned long used = child_length(tn);
821 unsigned long threshold = used;
822
823 /* Keep root node larger */
824 threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold;
825 used -= tn_info(tn)->empty_children;
826
827 /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */
828
829 return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold);
830}
831
832static inline bool should_collapse(struct key_vector *tn)
833{
834 unsigned long used = child_length(tn);
835
836 used -= tn_info(tn)->empty_children;
837
838 /* account for bits == KEYLENGTH case */
839 if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children)
840 used -= KEY_MAX;
841
842 /* One child or none, time to drop us from the trie */
843 return used < 2;
844}
845
846#define MAX_WORK 10
847static struct key_vector *resize(struct trie *t, struct key_vector *tn)
848{
849#ifdef CONFIG_IP_FIB_TRIE_STATS
850 struct trie_use_stats __percpu *stats = t->stats;
851#endif
852 struct key_vector *tp = node_parent(tn);
853 unsigned long cindex = get_index(tn->key, tp);
854 int max_work = MAX_WORK;
855
856 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
857 tn, inflate_threshold, halve_threshold);
858
859 /* track the tnode via the pointer from the parent instead of
860 * doing it ourselves. This way we can let RCU fully do its
861 * thing without us interfering
862 */
863 BUG_ON(tn != get_child(tp, cindex));
864
865 /* Double as long as the resulting node has a number of
866 * nonempty nodes that are above the threshold.
867 */
868 while (should_inflate(tp, tn) && max_work) {
869 tp = inflate(t, tn);
870 if (!tp) {
871#ifdef CONFIG_IP_FIB_TRIE_STATS
872 this_cpu_inc(stats->resize_node_skipped);
873#endif
874 break;
875 }
876
877 max_work--;
878 tn = get_child(tp, cindex);
879 }
880
881 /* update parent in case inflate failed */
882 tp = node_parent(tn);
883
884 /* Return if at least one inflate is run */
885 if (max_work != MAX_WORK)
886 return tp;
887
888 /* Halve as long as the number of empty children in this
889 * node is above threshold.
890 */
891 while (should_halve(tp, tn) && max_work) {
892 tp = halve(t, tn);
893 if (!tp) {
894#ifdef CONFIG_IP_FIB_TRIE_STATS
895 this_cpu_inc(stats->resize_node_skipped);
896#endif
897 break;
898 }
899
900 max_work--;
901 tn = get_child(tp, cindex);
902 }
903
904 /* Only one child remains */
905 if (should_collapse(tn))
906 return collapse(t, tn);
907
908 /* update parent in case halve failed */
909 return node_parent(tn);
910}
911
912static void node_pull_suffix(struct key_vector *tn, unsigned char slen)
913{
914 unsigned char node_slen = tn->slen;
915
916 while ((node_slen > tn->pos) && (node_slen > slen)) {
917 slen = update_suffix(tn);
918 if (node_slen == slen)
919 break;
920
921 tn = node_parent(tn);
922 node_slen = tn->slen;
923 }
924}
925
926static void node_push_suffix(struct key_vector *tn, unsigned char slen)
927{
928 while (tn->slen < slen) {
929 tn->slen = slen;
930 tn = node_parent(tn);
931 }
932}
933
934/* rcu_read_lock needs to be hold by caller from readside */
935static struct key_vector *fib_find_node(struct trie *t,
936 struct key_vector **tp, u32 key)
937{
938 struct key_vector *pn, *n = t->kv;
939 unsigned long index = 0;
940
941 do {
942 pn = n;
943 n = get_child_rcu(n, index);
944
945 if (!n)
946 break;
947
948 index = get_cindex(key, n);
949
950 /* This bit of code is a bit tricky but it combines multiple
951 * checks into a single check. The prefix consists of the
952 * prefix plus zeros for the bits in the cindex. The index
953 * is the difference between the key and this value. From
954 * this we can actually derive several pieces of data.
955 * if (index >= (1ul << bits))
956 * we have a mismatch in skip bits and failed
957 * else
958 * we know the value is cindex
959 *
960 * This check is safe even if bits == KEYLENGTH due to the
961 * fact that we can only allocate a node with 32 bits if a
962 * long is greater than 32 bits.
963 */
964 if (index >= (1ul << n->bits)) {
965 n = NULL;
966 break;
967 }
968
969 /* keep searching until we find a perfect match leaf or NULL */
970 } while (IS_TNODE(n));
971
972 *tp = pn;
973
974 return n;
975}
976
977/* Return the first fib alias matching DSCP with
978 * priority less than or equal to PRIO.
979 * If 'find_first' is set, return the first matching
980 * fib alias, regardless of DSCP and priority.
981 */
982static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen,
983 dscp_t dscp, u32 prio, u32 tb_id,
984 bool find_first)
985{
986 struct fib_alias *fa;
987
988 if (!fah)
989 return NULL;
990
991 hlist_for_each_entry(fa, fah, fa_list) {
992 /* Avoid Sparse warning when using dscp_t in inequalities */
993 u8 __fa_dscp = inet_dscp_to_dsfield(fa->fa_dscp);
994 u8 __dscp = inet_dscp_to_dsfield(dscp);
995
996 if (fa->fa_slen < slen)
997 continue;
998 if (fa->fa_slen != slen)
999 break;
1000 if (fa->tb_id > tb_id)
1001 continue;
1002 if (fa->tb_id != tb_id)
1003 break;
1004 if (find_first)
1005 return fa;
1006 if (__fa_dscp > __dscp)
1007 continue;
1008 if (fa->fa_info->fib_priority >= prio || __fa_dscp < __dscp)
1009 return fa;
1010 }
1011
1012 return NULL;
1013}
1014
1015static struct fib_alias *
1016fib_find_matching_alias(struct net *net, const struct fib_rt_info *fri)
1017{
1018 u8 slen = KEYLENGTH - fri->dst_len;
1019 struct key_vector *l, *tp;
1020 struct fib_table *tb;
1021 struct fib_alias *fa;
1022 struct trie *t;
1023
1024 tb = fib_get_table(net, fri->tb_id);
1025 if (!tb)
1026 return NULL;
1027
1028 t = (struct trie *)tb->tb_data;
1029 l = fib_find_node(t, &tp, be32_to_cpu(fri->dst));
1030 if (!l)
1031 return NULL;
1032
1033 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
1034 if (fa->fa_slen == slen && fa->tb_id == fri->tb_id &&
1035 fa->fa_dscp == fri->dscp && fa->fa_info == fri->fi &&
1036 fa->fa_type == fri->type)
1037 return fa;
1038 }
1039
1040 return NULL;
1041}
1042
1043void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri)
1044{
1045 u8 fib_notify_on_flag_change;
1046 struct fib_alias *fa_match;
1047 struct sk_buff *skb;
1048 int err;
1049
1050 rcu_read_lock();
1051
1052 fa_match = fib_find_matching_alias(net, fri);
1053 if (!fa_match)
1054 goto out;
1055
1056 /* These are paired with the WRITE_ONCE() happening in this function.
1057 * The reason is that we are only protected by RCU at this point.
1058 */
1059 if (READ_ONCE(fa_match->offload) == fri->offload &&
1060 READ_ONCE(fa_match->trap) == fri->trap &&
1061 READ_ONCE(fa_match->offload_failed) == fri->offload_failed)
1062 goto out;
1063
1064 WRITE_ONCE(fa_match->offload, fri->offload);
1065 WRITE_ONCE(fa_match->trap, fri->trap);
1066
1067 fib_notify_on_flag_change = READ_ONCE(net->ipv4.sysctl_fib_notify_on_flag_change);
1068
1069 /* 2 means send notifications only if offload_failed was changed. */
1070 if (fib_notify_on_flag_change == 2 &&
1071 READ_ONCE(fa_match->offload_failed) == fri->offload_failed)
1072 goto out;
1073
1074 WRITE_ONCE(fa_match->offload_failed, fri->offload_failed);
1075
1076 if (!fib_notify_on_flag_change)
1077 goto out;
1078
1079 skb = nlmsg_new(fib_nlmsg_size(fa_match->fa_info), GFP_ATOMIC);
1080 if (!skb) {
1081 err = -ENOBUFS;
1082 goto errout;
1083 }
1084
1085 err = fib_dump_info(skb, 0, 0, RTM_NEWROUTE, fri, 0);
1086 if (err < 0) {
1087 /* -EMSGSIZE implies BUG in fib_nlmsg_size() */
1088 WARN_ON(err == -EMSGSIZE);
1089 kfree_skb(skb);
1090 goto errout;
1091 }
1092
1093 rtnl_notify(skb, net, 0, RTNLGRP_IPV4_ROUTE, NULL, GFP_ATOMIC);
1094 goto out;
1095
1096errout:
1097 rtnl_set_sk_err(net, RTNLGRP_IPV4_ROUTE, err);
1098out:
1099 rcu_read_unlock();
1100}
1101EXPORT_SYMBOL_GPL(fib_alias_hw_flags_set);
1102
1103static void trie_rebalance(struct trie *t, struct key_vector *tn)
1104{
1105 while (!IS_TRIE(tn))
1106 tn = resize(t, tn);
1107}
1108
1109static int fib_insert_node(struct trie *t, struct key_vector *tp,
1110 struct fib_alias *new, t_key key)
1111{
1112 struct key_vector *n, *l;
1113
1114 l = leaf_new(key, new);
1115 if (!l)
1116 goto noleaf;
1117
1118 /* retrieve child from parent node */
1119 n = get_child(tp, get_index(key, tp));
1120
1121 /* Case 2: n is a LEAF or a TNODE and the key doesn't match.
1122 *
1123 * Add a new tnode here
1124 * first tnode need some special handling
1125 * leaves us in position for handling as case 3
1126 */
1127 if (n) {
1128 struct key_vector *tn;
1129
1130 tn = tnode_new(key, __fls(key ^ n->key), 1);
1131 if (!tn)
1132 goto notnode;
1133
1134 /* initialize routes out of node */
1135 NODE_INIT_PARENT(tn, tp);
1136 put_child(tn, get_index(key, tn) ^ 1, n);
1137
1138 /* start adding routes into the node */
1139 put_child_root(tp, key, tn);
1140 node_set_parent(n, tn);
1141
1142 /* parent now has a NULL spot where the leaf can go */
1143 tp = tn;
1144 }
1145
1146 /* Case 3: n is NULL, and will just insert a new leaf */
1147 node_push_suffix(tp, new->fa_slen);
1148 NODE_INIT_PARENT(l, tp);
1149 put_child_root(tp, key, l);
1150 trie_rebalance(t, tp);
1151
1152 return 0;
1153notnode:
1154 node_free(l);
1155noleaf:
1156 return -ENOMEM;
1157}
1158
1159static int fib_insert_alias(struct trie *t, struct key_vector *tp,
1160 struct key_vector *l, struct fib_alias *new,
1161 struct fib_alias *fa, t_key key)
1162{
1163 if (!l)
1164 return fib_insert_node(t, tp, new, key);
1165
1166 if (fa) {
1167 hlist_add_before_rcu(&new->fa_list, &fa->fa_list);
1168 } else {
1169 struct fib_alias *last;
1170
1171 hlist_for_each_entry(last, &l->leaf, fa_list) {
1172 if (new->fa_slen < last->fa_slen)
1173 break;
1174 if ((new->fa_slen == last->fa_slen) &&
1175 (new->tb_id > last->tb_id))
1176 break;
1177 fa = last;
1178 }
1179
1180 if (fa)
1181 hlist_add_behind_rcu(&new->fa_list, &fa->fa_list);
1182 else
1183 hlist_add_head_rcu(&new->fa_list, &l->leaf);
1184 }
1185
1186 /* if we added to the tail node then we need to update slen */
1187 if (l->slen < new->fa_slen) {
1188 l->slen = new->fa_slen;
1189 node_push_suffix(tp, new->fa_slen);
1190 }
1191
1192 return 0;
1193}
1194
1195static bool fib_valid_key_len(u32 key, u8 plen, struct netlink_ext_ack *extack)
1196{
1197 if (plen > KEYLENGTH) {
1198 NL_SET_ERR_MSG(extack, "Invalid prefix length");
1199 return false;
1200 }
1201
1202 if ((plen < KEYLENGTH) && (key << plen)) {
1203 NL_SET_ERR_MSG(extack,
1204 "Invalid prefix for given prefix length");
1205 return false;
1206 }
1207
1208 return true;
1209}
1210
1211static void fib_remove_alias(struct trie *t, struct key_vector *tp,
1212 struct key_vector *l, struct fib_alias *old);
1213
1214/* Caller must hold RTNL. */
1215int fib_table_insert(struct net *net, struct fib_table *tb,
1216 struct fib_config *cfg, struct netlink_ext_ack *extack)
1217{
1218 struct trie *t = (struct trie *)tb->tb_data;
1219 struct fib_alias *fa, *new_fa;
1220 struct key_vector *l, *tp;
1221 u16 nlflags = NLM_F_EXCL;
1222 struct fib_info *fi;
1223 u8 plen = cfg->fc_dst_len;
1224 u8 slen = KEYLENGTH - plen;
1225 dscp_t dscp;
1226 u32 key;
1227 int err;
1228
1229 key = ntohl(cfg->fc_dst);
1230
1231 if (!fib_valid_key_len(key, plen, extack))
1232 return -EINVAL;
1233
1234 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
1235
1236 fi = fib_create_info(cfg, extack);
1237 if (IS_ERR(fi)) {
1238 err = PTR_ERR(fi);
1239 goto err;
1240 }
1241
1242 dscp = cfg->fc_dscp;
1243 l = fib_find_node(t, &tp, key);
1244 fa = l ? fib_find_alias(&l->leaf, slen, dscp, fi->fib_priority,
1245 tb->tb_id, false) : NULL;
1246
1247 /* Now fa, if non-NULL, points to the first fib alias
1248 * with the same keys [prefix,dscp,priority], if such key already
1249 * exists or to the node before which we will insert new one.
1250 *
1251 * If fa is NULL, we will need to allocate a new one and
1252 * insert to the tail of the section matching the suffix length
1253 * of the new alias.
1254 */
1255
1256 if (fa && fa->fa_dscp == dscp &&
1257 fa->fa_info->fib_priority == fi->fib_priority) {
1258 struct fib_alias *fa_first, *fa_match;
1259
1260 err = -EEXIST;
1261 if (cfg->fc_nlflags & NLM_F_EXCL)
1262 goto out;
1263
1264 nlflags &= ~NLM_F_EXCL;
1265
1266 /* We have 2 goals:
1267 * 1. Find exact match for type, scope, fib_info to avoid
1268 * duplicate routes
1269 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
1270 */
1271 fa_match = NULL;
1272 fa_first = fa;
1273 hlist_for_each_entry_from(fa, fa_list) {
1274 if ((fa->fa_slen != slen) ||
1275 (fa->tb_id != tb->tb_id) ||
1276 (fa->fa_dscp != dscp))
1277 break;
1278 if (fa->fa_info->fib_priority != fi->fib_priority)
1279 break;
1280 if (fa->fa_type == cfg->fc_type &&
1281 fa->fa_info == fi) {
1282 fa_match = fa;
1283 break;
1284 }
1285 }
1286
1287 if (cfg->fc_nlflags & NLM_F_REPLACE) {
1288 struct fib_info *fi_drop;
1289 u8 state;
1290
1291 nlflags |= NLM_F_REPLACE;
1292 fa = fa_first;
1293 if (fa_match) {
1294 if (fa == fa_match)
1295 err = 0;
1296 goto out;
1297 }
1298 err = -ENOBUFS;
1299 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1300 if (!new_fa)
1301 goto out;
1302
1303 fi_drop = fa->fa_info;
1304 new_fa->fa_dscp = fa->fa_dscp;
1305 new_fa->fa_info = fi;
1306 new_fa->fa_type = cfg->fc_type;
1307 state = fa->fa_state;
1308 new_fa->fa_state = state & ~FA_S_ACCESSED;
1309 new_fa->fa_slen = fa->fa_slen;
1310 new_fa->tb_id = tb->tb_id;
1311 new_fa->fa_default = -1;
1312 new_fa->offload = 0;
1313 new_fa->trap = 0;
1314 new_fa->offload_failed = 0;
1315
1316 hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list);
1317
1318 if (fib_find_alias(&l->leaf, fa->fa_slen, 0, 0,
1319 tb->tb_id, true) == new_fa) {
1320 enum fib_event_type fib_event;
1321
1322 fib_event = FIB_EVENT_ENTRY_REPLACE;
1323 err = call_fib_entry_notifiers(net, fib_event,
1324 key, plen,
1325 new_fa, extack);
1326 if (err) {
1327 hlist_replace_rcu(&new_fa->fa_list,
1328 &fa->fa_list);
1329 goto out_free_new_fa;
1330 }
1331 }
1332
1333 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
1334 tb->tb_id, &cfg->fc_nlinfo, nlflags);
1335
1336 alias_free_mem_rcu(fa);
1337
1338 fib_release_info(fi_drop);
1339 if (state & FA_S_ACCESSED)
1340 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1341
1342 goto succeeded;
1343 }
1344 /* Error if we find a perfect match which
1345 * uses the same scope, type, and nexthop
1346 * information.
1347 */
1348 if (fa_match)
1349 goto out;
1350
1351 if (cfg->fc_nlflags & NLM_F_APPEND)
1352 nlflags |= NLM_F_APPEND;
1353 else
1354 fa = fa_first;
1355 }
1356 err = -ENOENT;
1357 if (!(cfg->fc_nlflags & NLM_F_CREATE))
1358 goto out;
1359
1360 nlflags |= NLM_F_CREATE;
1361 err = -ENOBUFS;
1362 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1363 if (!new_fa)
1364 goto out;
1365
1366 new_fa->fa_info = fi;
1367 new_fa->fa_dscp = dscp;
1368 new_fa->fa_type = cfg->fc_type;
1369 new_fa->fa_state = 0;
1370 new_fa->fa_slen = slen;
1371 new_fa->tb_id = tb->tb_id;
1372 new_fa->fa_default = -1;
1373 new_fa->offload = 0;
1374 new_fa->trap = 0;
1375 new_fa->offload_failed = 0;
1376
1377 /* Insert new entry to the list. */
1378 err = fib_insert_alias(t, tp, l, new_fa, fa, key);
1379 if (err)
1380 goto out_free_new_fa;
1381
1382 /* The alias was already inserted, so the node must exist. */
1383 l = l ? l : fib_find_node(t, &tp, key);
1384 if (WARN_ON_ONCE(!l)) {
1385 err = -ENOENT;
1386 goto out_free_new_fa;
1387 }
1388
1389 if (fib_find_alias(&l->leaf, new_fa->fa_slen, 0, 0, tb->tb_id, true) ==
1390 new_fa) {
1391 enum fib_event_type fib_event;
1392
1393 fib_event = FIB_EVENT_ENTRY_REPLACE;
1394 err = call_fib_entry_notifiers(net, fib_event, key, plen,
1395 new_fa, extack);
1396 if (err)
1397 goto out_remove_new_fa;
1398 }
1399
1400 if (!plen)
1401 tb->tb_num_default++;
1402
1403 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1404 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id,
1405 &cfg->fc_nlinfo, nlflags);
1406succeeded:
1407 return 0;
1408
1409out_remove_new_fa:
1410 fib_remove_alias(t, tp, l, new_fa);
1411out_free_new_fa:
1412 kmem_cache_free(fn_alias_kmem, new_fa);
1413out:
1414 fib_release_info(fi);
1415err:
1416 return err;
1417}
1418
1419static inline t_key prefix_mismatch(t_key key, struct key_vector *n)
1420{
1421 t_key prefix = n->key;
1422
1423 return (key ^ prefix) & (prefix | -prefix);
1424}
1425
1426bool fib_lookup_good_nhc(const struct fib_nh_common *nhc, int fib_flags,
1427 const struct flowi4 *flp)
1428{
1429 if (nhc->nhc_flags & RTNH_F_DEAD)
1430 return false;
1431
1432 if (ip_ignore_linkdown(nhc->nhc_dev) &&
1433 nhc->nhc_flags & RTNH_F_LINKDOWN &&
1434 !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE))
1435 return false;
1436
1437 if (flp->flowi4_oif && flp->flowi4_oif != nhc->nhc_oif)
1438 return false;
1439
1440 return true;
1441}
1442
1443/* should be called with rcu_read_lock */
1444int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
1445 struct fib_result *res, int fib_flags)
1446{
1447 struct trie *t = (struct trie *) tb->tb_data;
1448#ifdef CONFIG_IP_FIB_TRIE_STATS
1449 struct trie_use_stats __percpu *stats = t->stats;
1450#endif
1451 const t_key key = ntohl(flp->daddr);
1452 struct key_vector *n, *pn;
1453 struct fib_alias *fa;
1454 unsigned long index;
1455 t_key cindex;
1456
1457 pn = t->kv;
1458 cindex = 0;
1459
1460 n = get_child_rcu(pn, cindex);
1461 if (!n) {
1462 trace_fib_table_lookup(tb->tb_id, flp, NULL, -EAGAIN);
1463 return -EAGAIN;
1464 }
1465
1466#ifdef CONFIG_IP_FIB_TRIE_STATS
1467 this_cpu_inc(stats->gets);
1468#endif
1469
1470 /* Step 1: Travel to the longest prefix match in the trie */
1471 for (;;) {
1472 index = get_cindex(key, n);
1473
1474 /* This bit of code is a bit tricky but it combines multiple
1475 * checks into a single check. The prefix consists of the
1476 * prefix plus zeros for the "bits" in the prefix. The index
1477 * is the difference between the key and this value. From
1478 * this we can actually derive several pieces of data.
1479 * if (index >= (1ul << bits))
1480 * we have a mismatch in skip bits and failed
1481 * else
1482 * we know the value is cindex
1483 *
1484 * This check is safe even if bits == KEYLENGTH due to the
1485 * fact that we can only allocate a node with 32 bits if a
1486 * long is greater than 32 bits.
1487 */
1488 if (index >= (1ul << n->bits))
1489 break;
1490
1491 /* we have found a leaf. Prefixes have already been compared */
1492 if (IS_LEAF(n))
1493 goto found;
1494
1495 /* only record pn and cindex if we are going to be chopping
1496 * bits later. Otherwise we are just wasting cycles.
1497 */
1498 if (n->slen > n->pos) {
1499 pn = n;
1500 cindex = index;
1501 }
1502
1503 n = get_child_rcu(n, index);
1504 if (unlikely(!n))
1505 goto backtrace;
1506 }
1507
1508 /* Step 2: Sort out leaves and begin backtracing for longest prefix */
1509 for (;;) {
1510 /* record the pointer where our next node pointer is stored */
1511 struct key_vector __rcu **cptr = n->tnode;
1512
1513 /* This test verifies that none of the bits that differ
1514 * between the key and the prefix exist in the region of
1515 * the lsb and higher in the prefix.
1516 */
1517 if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos))
1518 goto backtrace;
1519
1520 /* exit out and process leaf */
1521 if (unlikely(IS_LEAF(n)))
1522 break;
1523
1524 /* Don't bother recording parent info. Since we are in
1525 * prefix match mode we will have to come back to wherever
1526 * we started this traversal anyway
1527 */
1528
1529 while ((n = rcu_dereference(*cptr)) == NULL) {
1530backtrace:
1531#ifdef CONFIG_IP_FIB_TRIE_STATS
1532 if (!n)
1533 this_cpu_inc(stats->null_node_hit);
1534#endif
1535 /* If we are at cindex 0 there are no more bits for
1536 * us to strip at this level so we must ascend back
1537 * up one level to see if there are any more bits to
1538 * be stripped there.
1539 */
1540 while (!cindex) {
1541 t_key pkey = pn->key;
1542
1543 /* If we don't have a parent then there is
1544 * nothing for us to do as we do not have any
1545 * further nodes to parse.
1546 */
1547 if (IS_TRIE(pn)) {
1548 trace_fib_table_lookup(tb->tb_id, flp,
1549 NULL, -EAGAIN);
1550 return -EAGAIN;
1551 }
1552#ifdef CONFIG_IP_FIB_TRIE_STATS
1553 this_cpu_inc(stats->backtrack);
1554#endif
1555 /* Get Child's index */
1556 pn = node_parent_rcu(pn);
1557 cindex = get_index(pkey, pn);
1558 }
1559
1560 /* strip the least significant bit from the cindex */
1561 cindex &= cindex - 1;
1562
1563 /* grab pointer for next child node */
1564 cptr = &pn->tnode[cindex];
1565 }
1566 }
1567
1568found:
1569 /* this line carries forward the xor from earlier in the function */
1570 index = key ^ n->key;
1571
1572 /* Step 3: Process the leaf, if that fails fall back to backtracing */
1573 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
1574 struct fib_info *fi = fa->fa_info;
1575 struct fib_nh_common *nhc;
1576 int nhsel, err;
1577
1578 if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) {
1579 if (index >= (1ul << fa->fa_slen))
1580 continue;
1581 }
1582 if (fa->fa_dscp &&
1583 inet_dscp_to_dsfield(fa->fa_dscp) != flp->flowi4_tos)
1584 continue;
1585 if (fi->fib_dead)
1586 continue;
1587 if (fa->fa_info->fib_scope < flp->flowi4_scope)
1588 continue;
1589 fib_alias_accessed(fa);
1590 err = fib_props[fa->fa_type].error;
1591 if (unlikely(err < 0)) {
1592out_reject:
1593#ifdef CONFIG_IP_FIB_TRIE_STATS
1594 this_cpu_inc(stats->semantic_match_passed);
1595#endif
1596 trace_fib_table_lookup(tb->tb_id, flp, NULL, err);
1597 return err;
1598 }
1599 if (fi->fib_flags & RTNH_F_DEAD)
1600 continue;
1601
1602 if (unlikely(fi->nh)) {
1603 if (nexthop_is_blackhole(fi->nh)) {
1604 err = fib_props[RTN_BLACKHOLE].error;
1605 goto out_reject;
1606 }
1607
1608 nhc = nexthop_get_nhc_lookup(fi->nh, fib_flags, flp,
1609 &nhsel);
1610 if (nhc)
1611 goto set_result;
1612 goto miss;
1613 }
1614
1615 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) {
1616 nhc = fib_info_nhc(fi, nhsel);
1617
1618 if (!fib_lookup_good_nhc(nhc, fib_flags, flp))
1619 continue;
1620set_result:
1621 if (!(fib_flags & FIB_LOOKUP_NOREF))
1622 refcount_inc(&fi->fib_clntref);
1623
1624 res->prefix = htonl(n->key);
1625 res->prefixlen = KEYLENGTH - fa->fa_slen;
1626 res->nh_sel = nhsel;
1627 res->nhc = nhc;
1628 res->type = fa->fa_type;
1629 res->scope = fi->fib_scope;
1630 res->fi = fi;
1631 res->table = tb;
1632 res->fa_head = &n->leaf;
1633#ifdef CONFIG_IP_FIB_TRIE_STATS
1634 this_cpu_inc(stats->semantic_match_passed);
1635#endif
1636 trace_fib_table_lookup(tb->tb_id, flp, nhc, err);
1637
1638 return err;
1639 }
1640 }
1641miss:
1642#ifdef CONFIG_IP_FIB_TRIE_STATS
1643 this_cpu_inc(stats->semantic_match_miss);
1644#endif
1645 goto backtrace;
1646}
1647EXPORT_SYMBOL_GPL(fib_table_lookup);
1648
1649static void fib_remove_alias(struct trie *t, struct key_vector *tp,
1650 struct key_vector *l, struct fib_alias *old)
1651{
1652 /* record the location of the previous list_info entry */
1653 struct hlist_node **pprev = old->fa_list.pprev;
1654 struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next);
1655
1656 /* remove the fib_alias from the list */
1657 hlist_del_rcu(&old->fa_list);
1658
1659 /* if we emptied the list this leaf will be freed and we can sort
1660 * out parent suffix lengths as a part of trie_rebalance
1661 */
1662 if (hlist_empty(&l->leaf)) {
1663 if (tp->slen == l->slen)
1664 node_pull_suffix(tp, tp->pos);
1665 put_child_root(tp, l->key, NULL);
1666 node_free(l);
1667 trie_rebalance(t, tp);
1668 return;
1669 }
1670
1671 /* only access fa if it is pointing at the last valid hlist_node */
1672 if (*pprev)
1673 return;
1674
1675 /* update the trie with the latest suffix length */
1676 l->slen = fa->fa_slen;
1677 node_pull_suffix(tp, fa->fa_slen);
1678}
1679
1680static void fib_notify_alias_delete(struct net *net, u32 key,
1681 struct hlist_head *fah,
1682 struct fib_alias *fa_to_delete,
1683 struct netlink_ext_ack *extack)
1684{
1685 struct fib_alias *fa_next, *fa_to_notify;
1686 u32 tb_id = fa_to_delete->tb_id;
1687 u8 slen = fa_to_delete->fa_slen;
1688 enum fib_event_type fib_event;
1689
1690 /* Do not notify if we do not care about the route. */
1691 if (fib_find_alias(fah, slen, 0, 0, tb_id, true) != fa_to_delete)
1692 return;
1693
1694 /* Determine if the route should be replaced by the next route in the
1695 * list.
1696 */
1697 fa_next = hlist_entry_safe(fa_to_delete->fa_list.next,
1698 struct fib_alias, fa_list);
1699 if (fa_next && fa_next->fa_slen == slen && fa_next->tb_id == tb_id) {
1700 fib_event = FIB_EVENT_ENTRY_REPLACE;
1701 fa_to_notify = fa_next;
1702 } else {
1703 fib_event = FIB_EVENT_ENTRY_DEL;
1704 fa_to_notify = fa_to_delete;
1705 }
1706 call_fib_entry_notifiers(net, fib_event, key, KEYLENGTH - slen,
1707 fa_to_notify, extack);
1708}
1709
1710/* Caller must hold RTNL. */
1711int fib_table_delete(struct net *net, struct fib_table *tb,
1712 struct fib_config *cfg, struct netlink_ext_ack *extack)
1713{
1714 struct trie *t = (struct trie *) tb->tb_data;
1715 struct fib_alias *fa, *fa_to_delete;
1716 struct key_vector *l, *tp;
1717 u8 plen = cfg->fc_dst_len;
1718 u8 slen = KEYLENGTH - plen;
1719 dscp_t dscp;
1720 u32 key;
1721
1722 key = ntohl(cfg->fc_dst);
1723
1724 if (!fib_valid_key_len(key, plen, extack))
1725 return -EINVAL;
1726
1727 l = fib_find_node(t, &tp, key);
1728 if (!l)
1729 return -ESRCH;
1730
1731 dscp = cfg->fc_dscp;
1732 fa = fib_find_alias(&l->leaf, slen, dscp, 0, tb->tb_id, false);
1733 if (!fa)
1734 return -ESRCH;
1735
1736 pr_debug("Deleting %08x/%d dsfield=0x%02x t=%p\n", key, plen,
1737 inet_dscp_to_dsfield(dscp), t);
1738
1739 fa_to_delete = NULL;
1740 hlist_for_each_entry_from(fa, fa_list) {
1741 struct fib_info *fi = fa->fa_info;
1742
1743 if ((fa->fa_slen != slen) ||
1744 (fa->tb_id != tb->tb_id) ||
1745 (fa->fa_dscp != dscp))
1746 break;
1747
1748 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
1749 (cfg->fc_scope == RT_SCOPE_NOWHERE ||
1750 fa->fa_info->fib_scope == cfg->fc_scope) &&
1751 (!cfg->fc_prefsrc ||
1752 fi->fib_prefsrc == cfg->fc_prefsrc) &&
1753 (!cfg->fc_protocol ||
1754 fi->fib_protocol == cfg->fc_protocol) &&
1755 fib_nh_match(net, cfg, fi, extack) == 0 &&
1756 fib_metrics_match(cfg, fi)) {
1757 fa_to_delete = fa;
1758 break;
1759 }
1760 }
1761
1762 if (!fa_to_delete)
1763 return -ESRCH;
1764
1765 fib_notify_alias_delete(net, key, &l->leaf, fa_to_delete, extack);
1766 rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id,
1767 &cfg->fc_nlinfo, 0);
1768
1769 if (!plen)
1770 tb->tb_num_default--;
1771
1772 fib_remove_alias(t, tp, l, fa_to_delete);
1773
1774 if (fa_to_delete->fa_state & FA_S_ACCESSED)
1775 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1776
1777 fib_release_info(fa_to_delete->fa_info);
1778 alias_free_mem_rcu(fa_to_delete);
1779 return 0;
1780}
1781
1782/* Scan for the next leaf starting at the provided key value */
1783static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key)
1784{
1785 struct key_vector *pn, *n = *tn;
1786 unsigned long cindex;
1787
1788 /* this loop is meant to try and find the key in the trie */
1789 do {
1790 /* record parent and next child index */
1791 pn = n;
1792 cindex = (key > pn->key) ? get_index(key, pn) : 0;
1793
1794 if (cindex >> pn->bits)
1795 break;
1796
1797 /* descend into the next child */
1798 n = get_child_rcu(pn, cindex++);
1799 if (!n)
1800 break;
1801
1802 /* guarantee forward progress on the keys */
1803 if (IS_LEAF(n) && (n->key >= key))
1804 goto found;
1805 } while (IS_TNODE(n));
1806
1807 /* this loop will search for the next leaf with a greater key */
1808 while (!IS_TRIE(pn)) {
1809 /* if we exhausted the parent node we will need to climb */
1810 if (cindex >= (1ul << pn->bits)) {
1811 t_key pkey = pn->key;
1812
1813 pn = node_parent_rcu(pn);
1814 cindex = get_index(pkey, pn) + 1;
1815 continue;
1816 }
1817
1818 /* grab the next available node */
1819 n = get_child_rcu(pn, cindex++);
1820 if (!n)
1821 continue;
1822
1823 /* no need to compare keys since we bumped the index */
1824 if (IS_LEAF(n))
1825 goto found;
1826
1827 /* Rescan start scanning in new node */
1828 pn = n;
1829 cindex = 0;
1830 }
1831
1832 *tn = pn;
1833 return NULL; /* Root of trie */
1834found:
1835 /* if we are at the limit for keys just return NULL for the tnode */
1836 *tn = pn;
1837 return n;
1838}
1839
1840static void fib_trie_free(struct fib_table *tb)
1841{
1842 struct trie *t = (struct trie *)tb->tb_data;
1843 struct key_vector *pn = t->kv;
1844 unsigned long cindex = 1;
1845 struct hlist_node *tmp;
1846 struct fib_alias *fa;
1847
1848 /* walk trie in reverse order and free everything */
1849 for (;;) {
1850 struct key_vector *n;
1851
1852 if (!(cindex--)) {
1853 t_key pkey = pn->key;
1854
1855 if (IS_TRIE(pn))
1856 break;
1857
1858 n = pn;
1859 pn = node_parent(pn);
1860
1861 /* drop emptied tnode */
1862 put_child_root(pn, n->key, NULL);
1863 node_free(n);
1864
1865 cindex = get_index(pkey, pn);
1866
1867 continue;
1868 }
1869
1870 /* grab the next available node */
1871 n = get_child(pn, cindex);
1872 if (!n)
1873 continue;
1874
1875 if (IS_TNODE(n)) {
1876 /* record pn and cindex for leaf walking */
1877 pn = n;
1878 cindex = 1ul << n->bits;
1879
1880 continue;
1881 }
1882
1883 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1884 hlist_del_rcu(&fa->fa_list);
1885 alias_free_mem_rcu(fa);
1886 }
1887
1888 put_child_root(pn, n->key, NULL);
1889 node_free(n);
1890 }
1891
1892#ifdef CONFIG_IP_FIB_TRIE_STATS
1893 free_percpu(t->stats);
1894#endif
1895 kfree(tb);
1896}
1897
1898struct fib_table *fib_trie_unmerge(struct fib_table *oldtb)
1899{
1900 struct trie *ot = (struct trie *)oldtb->tb_data;
1901 struct key_vector *l, *tp = ot->kv;
1902 struct fib_table *local_tb;
1903 struct fib_alias *fa;
1904 struct trie *lt;
1905 t_key key = 0;
1906
1907 if (oldtb->tb_data == oldtb->__data)
1908 return oldtb;
1909
1910 local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL);
1911 if (!local_tb)
1912 return NULL;
1913
1914 lt = (struct trie *)local_tb->tb_data;
1915
1916 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
1917 struct key_vector *local_l = NULL, *local_tp;
1918
1919 hlist_for_each_entry(fa, &l->leaf, fa_list) {
1920 struct fib_alias *new_fa;
1921
1922 if (local_tb->tb_id != fa->tb_id)
1923 continue;
1924
1925 /* clone fa for new local table */
1926 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1927 if (!new_fa)
1928 goto out;
1929
1930 memcpy(new_fa, fa, sizeof(*fa));
1931
1932 /* insert clone into table */
1933 if (!local_l)
1934 local_l = fib_find_node(lt, &local_tp, l->key);
1935
1936 if (fib_insert_alias(lt, local_tp, local_l, new_fa,
1937 NULL, l->key)) {
1938 kmem_cache_free(fn_alias_kmem, new_fa);
1939 goto out;
1940 }
1941 }
1942
1943 /* stop loop if key wrapped back to 0 */
1944 key = l->key + 1;
1945 if (key < l->key)
1946 break;
1947 }
1948
1949 return local_tb;
1950out:
1951 fib_trie_free(local_tb);
1952
1953 return NULL;
1954}
1955
1956/* Caller must hold RTNL */
1957void fib_table_flush_external(struct fib_table *tb)
1958{
1959 struct trie *t = (struct trie *)tb->tb_data;
1960 struct key_vector *pn = t->kv;
1961 unsigned long cindex = 1;
1962 struct hlist_node *tmp;
1963 struct fib_alias *fa;
1964
1965 /* walk trie in reverse order */
1966 for (;;) {
1967 unsigned char slen = 0;
1968 struct key_vector *n;
1969
1970 if (!(cindex--)) {
1971 t_key pkey = pn->key;
1972
1973 /* cannot resize the trie vector */
1974 if (IS_TRIE(pn))
1975 break;
1976
1977 /* update the suffix to address pulled leaves */
1978 if (pn->slen > pn->pos)
1979 update_suffix(pn);
1980
1981 /* resize completed node */
1982 pn = resize(t, pn);
1983 cindex = get_index(pkey, pn);
1984
1985 continue;
1986 }
1987
1988 /* grab the next available node */
1989 n = get_child(pn, cindex);
1990 if (!n)
1991 continue;
1992
1993 if (IS_TNODE(n)) {
1994 /* record pn and cindex for leaf walking */
1995 pn = n;
1996 cindex = 1ul << n->bits;
1997
1998 continue;
1999 }
2000
2001 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
2002 /* if alias was cloned to local then we just
2003 * need to remove the local copy from main
2004 */
2005 if (tb->tb_id != fa->tb_id) {
2006 hlist_del_rcu(&fa->fa_list);
2007 alias_free_mem_rcu(fa);
2008 continue;
2009 }
2010
2011 /* record local slen */
2012 slen = fa->fa_slen;
2013 }
2014
2015 /* update leaf slen */
2016 n->slen = slen;
2017
2018 if (hlist_empty(&n->leaf)) {
2019 put_child_root(pn, n->key, NULL);
2020 node_free(n);
2021 }
2022 }
2023}
2024
2025/* Caller must hold RTNL. */
2026int fib_table_flush(struct net *net, struct fib_table *tb, bool flush_all)
2027{
2028 struct trie *t = (struct trie *)tb->tb_data;
2029 struct key_vector *pn = t->kv;
2030 unsigned long cindex = 1;
2031 struct hlist_node *tmp;
2032 struct fib_alias *fa;
2033 int found = 0;
2034
2035 /* walk trie in reverse order */
2036 for (;;) {
2037 unsigned char slen = 0;
2038 struct key_vector *n;
2039
2040 if (!(cindex--)) {
2041 t_key pkey = pn->key;
2042
2043 /* cannot resize the trie vector */
2044 if (IS_TRIE(pn))
2045 break;
2046
2047 /* update the suffix to address pulled leaves */
2048 if (pn->slen > pn->pos)
2049 update_suffix(pn);
2050
2051 /* resize completed node */
2052 pn = resize(t, pn);
2053 cindex = get_index(pkey, pn);
2054
2055 continue;
2056 }
2057
2058 /* grab the next available node */
2059 n = get_child(pn, cindex);
2060 if (!n)
2061 continue;
2062
2063 if (IS_TNODE(n)) {
2064 /* record pn and cindex for leaf walking */
2065 pn = n;
2066 cindex = 1ul << n->bits;
2067
2068 continue;
2069 }
2070
2071 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
2072 struct fib_info *fi = fa->fa_info;
2073
2074 if (!fi || tb->tb_id != fa->tb_id ||
2075 (!(fi->fib_flags & RTNH_F_DEAD) &&
2076 !fib_props[fa->fa_type].error)) {
2077 slen = fa->fa_slen;
2078 continue;
2079 }
2080
2081 /* Do not flush error routes if network namespace is
2082 * not being dismantled
2083 */
2084 if (!flush_all && fib_props[fa->fa_type].error) {
2085 slen = fa->fa_slen;
2086 continue;
2087 }
2088
2089 fib_notify_alias_delete(net, n->key, &n->leaf, fa,
2090 NULL);
2091 hlist_del_rcu(&fa->fa_list);
2092 fib_release_info(fa->fa_info);
2093 alias_free_mem_rcu(fa);
2094 found++;
2095 }
2096
2097 /* update leaf slen */
2098 n->slen = slen;
2099
2100 if (hlist_empty(&n->leaf)) {
2101 put_child_root(pn, n->key, NULL);
2102 node_free(n);
2103 }
2104 }
2105
2106 pr_debug("trie_flush found=%d\n", found);
2107 return found;
2108}
2109
2110/* derived from fib_trie_free */
2111static void __fib_info_notify_update(struct net *net, struct fib_table *tb,
2112 struct nl_info *info)
2113{
2114 struct trie *t = (struct trie *)tb->tb_data;
2115 struct key_vector *pn = t->kv;
2116 unsigned long cindex = 1;
2117 struct fib_alias *fa;
2118
2119 for (;;) {
2120 struct key_vector *n;
2121
2122 if (!(cindex--)) {
2123 t_key pkey = pn->key;
2124
2125 if (IS_TRIE(pn))
2126 break;
2127
2128 pn = node_parent(pn);
2129 cindex = get_index(pkey, pn);
2130 continue;
2131 }
2132
2133 /* grab the next available node */
2134 n = get_child(pn, cindex);
2135 if (!n)
2136 continue;
2137
2138 if (IS_TNODE(n)) {
2139 /* record pn and cindex for leaf walking */
2140 pn = n;
2141 cindex = 1ul << n->bits;
2142
2143 continue;
2144 }
2145
2146 hlist_for_each_entry(fa, &n->leaf, fa_list) {
2147 struct fib_info *fi = fa->fa_info;
2148
2149 if (!fi || !fi->nh_updated || fa->tb_id != tb->tb_id)
2150 continue;
2151
2152 rtmsg_fib(RTM_NEWROUTE, htonl(n->key), fa,
2153 KEYLENGTH - fa->fa_slen, tb->tb_id,
2154 info, NLM_F_REPLACE);
2155 }
2156 }
2157}
2158
2159void fib_info_notify_update(struct net *net, struct nl_info *info)
2160{
2161 unsigned int h;
2162
2163 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2164 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2165 struct fib_table *tb;
2166
2167 hlist_for_each_entry_rcu(tb, head, tb_hlist,
2168 lockdep_rtnl_is_held())
2169 __fib_info_notify_update(net, tb, info);
2170 }
2171}
2172
2173static int fib_leaf_notify(struct key_vector *l, struct fib_table *tb,
2174 struct notifier_block *nb,
2175 struct netlink_ext_ack *extack)
2176{
2177 struct fib_alias *fa;
2178 int last_slen = -1;
2179 int err;
2180
2181 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2182 struct fib_info *fi = fa->fa_info;
2183
2184 if (!fi)
2185 continue;
2186
2187 /* local and main table can share the same trie,
2188 * so don't notify twice for the same entry.
2189 */
2190 if (tb->tb_id != fa->tb_id)
2191 continue;
2192
2193 if (fa->fa_slen == last_slen)
2194 continue;
2195
2196 last_slen = fa->fa_slen;
2197 err = call_fib_entry_notifier(nb, FIB_EVENT_ENTRY_REPLACE,
2198 l->key, KEYLENGTH - fa->fa_slen,
2199 fa, extack);
2200 if (err)
2201 return err;
2202 }
2203 return 0;
2204}
2205
2206static int fib_table_notify(struct fib_table *tb, struct notifier_block *nb,
2207 struct netlink_ext_ack *extack)
2208{
2209 struct trie *t = (struct trie *)tb->tb_data;
2210 struct key_vector *l, *tp = t->kv;
2211 t_key key = 0;
2212 int err;
2213
2214 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
2215 err = fib_leaf_notify(l, tb, nb, extack);
2216 if (err)
2217 return err;
2218
2219 key = l->key + 1;
2220 /* stop in case of wrap around */
2221 if (key < l->key)
2222 break;
2223 }
2224 return 0;
2225}
2226
2227int fib_notify(struct net *net, struct notifier_block *nb,
2228 struct netlink_ext_ack *extack)
2229{
2230 unsigned int h;
2231 int err;
2232
2233 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2234 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2235 struct fib_table *tb;
2236
2237 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2238 err = fib_table_notify(tb, nb, extack);
2239 if (err)
2240 return err;
2241 }
2242 }
2243 return 0;
2244}
2245
2246static void __trie_free_rcu(struct rcu_head *head)
2247{
2248 struct fib_table *tb = container_of(head, struct fib_table, rcu);
2249#ifdef CONFIG_IP_FIB_TRIE_STATS
2250 struct trie *t = (struct trie *)tb->tb_data;
2251
2252 if (tb->tb_data == tb->__data)
2253 free_percpu(t->stats);
2254#endif /* CONFIG_IP_FIB_TRIE_STATS */
2255 kfree(tb);
2256}
2257
2258void fib_free_table(struct fib_table *tb)
2259{
2260 call_rcu(&tb->rcu, __trie_free_rcu);
2261}
2262
2263static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb,
2264 struct sk_buff *skb, struct netlink_callback *cb,
2265 struct fib_dump_filter *filter)
2266{
2267 unsigned int flags = NLM_F_MULTI;
2268 __be32 xkey = htonl(l->key);
2269 int i, s_i, i_fa, s_fa, err;
2270 struct fib_alias *fa;
2271
2272 if (filter->filter_set ||
2273 !filter->dump_exceptions || !filter->dump_routes)
2274 flags |= NLM_F_DUMP_FILTERED;
2275
2276 s_i = cb->args[4];
2277 s_fa = cb->args[5];
2278 i = 0;
2279
2280 /* rcu_read_lock is hold by caller */
2281 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2282 struct fib_info *fi = fa->fa_info;
2283
2284 if (i < s_i)
2285 goto next;
2286
2287 i_fa = 0;
2288
2289 if (tb->tb_id != fa->tb_id)
2290 goto next;
2291
2292 if (filter->filter_set) {
2293 if (filter->rt_type && fa->fa_type != filter->rt_type)
2294 goto next;
2295
2296 if ((filter->protocol &&
2297 fi->fib_protocol != filter->protocol))
2298 goto next;
2299
2300 if (filter->dev &&
2301 !fib_info_nh_uses_dev(fi, filter->dev))
2302 goto next;
2303 }
2304
2305 if (filter->dump_routes) {
2306 if (!s_fa) {
2307 struct fib_rt_info fri;
2308
2309 fri.fi = fi;
2310 fri.tb_id = tb->tb_id;
2311 fri.dst = xkey;
2312 fri.dst_len = KEYLENGTH - fa->fa_slen;
2313 fri.dscp = fa->fa_dscp;
2314 fri.type = fa->fa_type;
2315 fri.offload = READ_ONCE(fa->offload);
2316 fri.trap = READ_ONCE(fa->trap);
2317 fri.offload_failed = READ_ONCE(fa->offload_failed);
2318 err = fib_dump_info(skb,
2319 NETLINK_CB(cb->skb).portid,
2320 cb->nlh->nlmsg_seq,
2321 RTM_NEWROUTE, &fri, flags);
2322 if (err < 0)
2323 goto stop;
2324 }
2325
2326 i_fa++;
2327 }
2328
2329 if (filter->dump_exceptions) {
2330 err = fib_dump_info_fnhe(skb, cb, tb->tb_id, fi,
2331 &i_fa, s_fa, flags);
2332 if (err < 0)
2333 goto stop;
2334 }
2335
2336next:
2337 i++;
2338 }
2339
2340 cb->args[4] = i;
2341 return skb->len;
2342
2343stop:
2344 cb->args[4] = i;
2345 cb->args[5] = i_fa;
2346 return err;
2347}
2348
2349/* rcu_read_lock needs to be hold by caller from readside */
2350int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
2351 struct netlink_callback *cb, struct fib_dump_filter *filter)
2352{
2353 struct trie *t = (struct trie *)tb->tb_data;
2354 struct key_vector *l, *tp = t->kv;
2355 /* Dump starting at last key.
2356 * Note: 0.0.0.0/0 (ie default) is first key.
2357 */
2358 int count = cb->args[2];
2359 t_key key = cb->args[3];
2360
2361 /* First time here, count and key are both always 0. Count > 0
2362 * and key == 0 means the dump has wrapped around and we are done.
2363 */
2364 if (count && !key)
2365 return skb->len;
2366
2367 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
2368 int err;
2369
2370 err = fn_trie_dump_leaf(l, tb, skb, cb, filter);
2371 if (err < 0) {
2372 cb->args[3] = key;
2373 cb->args[2] = count;
2374 return err;
2375 }
2376
2377 ++count;
2378 key = l->key + 1;
2379
2380 memset(&cb->args[4], 0,
2381 sizeof(cb->args) - 4*sizeof(cb->args[0]));
2382
2383 /* stop loop if key wrapped back to 0 */
2384 if (key < l->key)
2385 break;
2386 }
2387
2388 cb->args[3] = key;
2389 cb->args[2] = count;
2390
2391 return skb->len;
2392}
2393
2394void __init fib_trie_init(void)
2395{
2396 fn_alias_kmem = kmem_cache_create("ip_fib_alias",
2397 sizeof(struct fib_alias),
2398 0, SLAB_PANIC | SLAB_ACCOUNT, NULL);
2399
2400 trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
2401 LEAF_SIZE,
2402 0, SLAB_PANIC | SLAB_ACCOUNT, NULL);
2403}
2404
2405struct fib_table *fib_trie_table(u32 id, struct fib_table *alias)
2406{
2407 struct fib_table *tb;
2408 struct trie *t;
2409 size_t sz = sizeof(*tb);
2410
2411 if (!alias)
2412 sz += sizeof(struct trie);
2413
2414 tb = kzalloc(sz, GFP_KERNEL);
2415 if (!tb)
2416 return NULL;
2417
2418 tb->tb_id = id;
2419 tb->tb_num_default = 0;
2420 tb->tb_data = (alias ? alias->__data : tb->__data);
2421
2422 if (alias)
2423 return tb;
2424
2425 t = (struct trie *) tb->tb_data;
2426 t->kv[0].pos = KEYLENGTH;
2427 t->kv[0].slen = KEYLENGTH;
2428#ifdef CONFIG_IP_FIB_TRIE_STATS
2429 t->stats = alloc_percpu(struct trie_use_stats);
2430 if (!t->stats) {
2431 kfree(tb);
2432 tb = NULL;
2433 }
2434#endif
2435
2436 return tb;
2437}
2438
2439#ifdef CONFIG_PROC_FS
2440/* Depth first Trie walk iterator */
2441struct fib_trie_iter {
2442 struct seq_net_private p;
2443 struct fib_table *tb;
2444 struct key_vector *tnode;
2445 unsigned int index;
2446 unsigned int depth;
2447};
2448
2449static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter)
2450{
2451 unsigned long cindex = iter->index;
2452 struct key_vector *pn = iter->tnode;
2453 t_key pkey;
2454
2455 pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
2456 iter->tnode, iter->index, iter->depth);
2457
2458 while (!IS_TRIE(pn)) {
2459 while (cindex < child_length(pn)) {
2460 struct key_vector *n = get_child_rcu(pn, cindex++);
2461
2462 if (!n)
2463 continue;
2464
2465 if (IS_LEAF(n)) {
2466 iter->tnode = pn;
2467 iter->index = cindex;
2468 } else {
2469 /* push down one level */
2470 iter->tnode = n;
2471 iter->index = 0;
2472 ++iter->depth;
2473 }
2474
2475 return n;
2476 }
2477
2478 /* Current node exhausted, pop back up */
2479 pkey = pn->key;
2480 pn = node_parent_rcu(pn);
2481 cindex = get_index(pkey, pn) + 1;
2482 --iter->depth;
2483 }
2484
2485 /* record root node so further searches know we are done */
2486 iter->tnode = pn;
2487 iter->index = 0;
2488
2489 return NULL;
2490}
2491
2492static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter,
2493 struct trie *t)
2494{
2495 struct key_vector *n, *pn;
2496
2497 if (!t)
2498 return NULL;
2499
2500 pn = t->kv;
2501 n = rcu_dereference(pn->tnode[0]);
2502 if (!n)
2503 return NULL;
2504
2505 if (IS_TNODE(n)) {
2506 iter->tnode = n;
2507 iter->index = 0;
2508 iter->depth = 1;
2509 } else {
2510 iter->tnode = pn;
2511 iter->index = 0;
2512 iter->depth = 0;
2513 }
2514
2515 return n;
2516}
2517
2518static void trie_collect_stats(struct trie *t, struct trie_stat *s)
2519{
2520 struct key_vector *n;
2521 struct fib_trie_iter iter;
2522
2523 memset(s, 0, sizeof(*s));
2524
2525 rcu_read_lock();
2526 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) {
2527 if (IS_LEAF(n)) {
2528 struct fib_alias *fa;
2529
2530 s->leaves++;
2531 s->totdepth += iter.depth;
2532 if (iter.depth > s->maxdepth)
2533 s->maxdepth = iter.depth;
2534
2535 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list)
2536 ++s->prefixes;
2537 } else {
2538 s->tnodes++;
2539 if (n->bits < MAX_STAT_DEPTH)
2540 s->nodesizes[n->bits]++;
2541 s->nullpointers += tn_info(n)->empty_children;
2542 }
2543 }
2544 rcu_read_unlock();
2545}
2546
2547/*
2548 * This outputs /proc/net/fib_triestats
2549 */
2550static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
2551{
2552 unsigned int i, max, pointers, bytes, avdepth;
2553
2554 if (stat->leaves)
2555 avdepth = stat->totdepth*100 / stat->leaves;
2556 else
2557 avdepth = 0;
2558
2559 seq_printf(seq, "\tAver depth: %u.%02d\n",
2560 avdepth / 100, avdepth % 100);
2561 seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth);
2562
2563 seq_printf(seq, "\tLeaves: %u\n", stat->leaves);
2564 bytes = LEAF_SIZE * stat->leaves;
2565
2566 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes);
2567 bytes += sizeof(struct fib_alias) * stat->prefixes;
2568
2569 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);
2570 bytes += TNODE_SIZE(0) * stat->tnodes;
2571
2572 max = MAX_STAT_DEPTH;
2573 while (max > 0 && stat->nodesizes[max-1] == 0)
2574 max--;
2575
2576 pointers = 0;
2577 for (i = 1; i < max; i++)
2578 if (stat->nodesizes[i] != 0) {
2579 seq_printf(seq, " %u: %u", i, stat->nodesizes[i]);
2580 pointers += (1<<i) * stat->nodesizes[i];
2581 }
2582 seq_putc(seq, '\n');
2583 seq_printf(seq, "\tPointers: %u\n", pointers);
2584
2585 bytes += sizeof(struct key_vector *) * pointers;
2586 seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers);
2587 seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024);
2588}
2589
2590#ifdef CONFIG_IP_FIB_TRIE_STATS
2591static void trie_show_usage(struct seq_file *seq,
2592 const struct trie_use_stats __percpu *stats)
2593{
2594 struct trie_use_stats s = { 0 };
2595 int cpu;
2596
2597 /* loop through all of the CPUs and gather up the stats */
2598 for_each_possible_cpu(cpu) {
2599 const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu);
2600
2601 s.gets += pcpu->gets;
2602 s.backtrack += pcpu->backtrack;
2603 s.semantic_match_passed += pcpu->semantic_match_passed;
2604 s.semantic_match_miss += pcpu->semantic_match_miss;
2605 s.null_node_hit += pcpu->null_node_hit;
2606 s.resize_node_skipped += pcpu->resize_node_skipped;
2607 }
2608
2609 seq_printf(seq, "\nCounters:\n---------\n");
2610 seq_printf(seq, "gets = %u\n", s.gets);
2611 seq_printf(seq, "backtracks = %u\n", s.backtrack);
2612 seq_printf(seq, "semantic match passed = %u\n",
2613 s.semantic_match_passed);
2614 seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss);
2615 seq_printf(seq, "null node hit= %u\n", s.null_node_hit);
2616 seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped);
2617}
2618#endif /* CONFIG_IP_FIB_TRIE_STATS */
2619
2620static void fib_table_print(struct seq_file *seq, struct fib_table *tb)
2621{
2622 if (tb->tb_id == RT_TABLE_LOCAL)
2623 seq_puts(seq, "Local:\n");
2624 else if (tb->tb_id == RT_TABLE_MAIN)
2625 seq_puts(seq, "Main:\n");
2626 else
2627 seq_printf(seq, "Id %d:\n", tb->tb_id);
2628}
2629
2630
2631static int fib_triestat_seq_show(struct seq_file *seq, void *v)
2632{
2633 struct net *net = seq->private;
2634 unsigned int h;
2635
2636 seq_printf(seq,
2637 "Basic info: size of leaf:"
2638 " %zd bytes, size of tnode: %zd bytes.\n",
2639 LEAF_SIZE, TNODE_SIZE(0));
2640
2641 rcu_read_lock();
2642 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2643 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2644 struct fib_table *tb;
2645
2646 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2647 struct trie *t = (struct trie *) tb->tb_data;
2648 struct trie_stat stat;
2649
2650 if (!t)
2651 continue;
2652
2653 fib_table_print(seq, tb);
2654
2655 trie_collect_stats(t, &stat);
2656 trie_show_stats(seq, &stat);
2657#ifdef CONFIG_IP_FIB_TRIE_STATS
2658 trie_show_usage(seq, t->stats);
2659#endif
2660 }
2661 cond_resched_rcu();
2662 }
2663 rcu_read_unlock();
2664
2665 return 0;
2666}
2667
2668static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos)
2669{
2670 struct fib_trie_iter *iter = seq->private;
2671 struct net *net = seq_file_net(seq);
2672 loff_t idx = 0;
2673 unsigned int h;
2674
2675 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2676 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2677 struct fib_table *tb;
2678
2679 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2680 struct key_vector *n;
2681
2682 for (n = fib_trie_get_first(iter,
2683 (struct trie *) tb->tb_data);
2684 n; n = fib_trie_get_next(iter))
2685 if (pos == idx++) {
2686 iter->tb = tb;
2687 return n;
2688 }
2689 }
2690 }
2691
2692 return NULL;
2693}
2694
2695static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
2696 __acquires(RCU)
2697{
2698 rcu_read_lock();
2699 return fib_trie_get_idx(seq, *pos);
2700}
2701
2702static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2703{
2704 struct fib_trie_iter *iter = seq->private;
2705 struct net *net = seq_file_net(seq);
2706 struct fib_table *tb = iter->tb;
2707 struct hlist_node *tb_node;
2708 unsigned int h;
2709 struct key_vector *n;
2710
2711 ++*pos;
2712 /* next node in same table */
2713 n = fib_trie_get_next(iter);
2714 if (n)
2715 return n;
2716
2717 /* walk rest of this hash chain */
2718 h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);
2719 while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) {
2720 tb = hlist_entry(tb_node, struct fib_table, tb_hlist);
2721 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2722 if (n)
2723 goto found;
2724 }
2725
2726 /* new hash chain */
2727 while (++h < FIB_TABLE_HASHSZ) {
2728 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2729 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2730 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2731 if (n)
2732 goto found;
2733 }
2734 }
2735 return NULL;
2736
2737found:
2738 iter->tb = tb;
2739 return n;
2740}
2741
2742static void fib_trie_seq_stop(struct seq_file *seq, void *v)
2743 __releases(RCU)
2744{
2745 rcu_read_unlock();
2746}
2747
2748static void seq_indent(struct seq_file *seq, int n)
2749{
2750 while (n-- > 0)
2751 seq_puts(seq, " ");
2752}
2753
2754static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
2755{
2756 switch (s) {
2757 case RT_SCOPE_UNIVERSE: return "universe";
2758 case RT_SCOPE_SITE: return "site";
2759 case RT_SCOPE_LINK: return "link";
2760 case RT_SCOPE_HOST: return "host";
2761 case RT_SCOPE_NOWHERE: return "nowhere";
2762 default:
2763 snprintf(buf, len, "scope=%d", s);
2764 return buf;
2765 }
2766}
2767
2768static const char *const rtn_type_names[__RTN_MAX] = {
2769 [RTN_UNSPEC] = "UNSPEC",
2770 [RTN_UNICAST] = "UNICAST",
2771 [RTN_LOCAL] = "LOCAL",
2772 [RTN_BROADCAST] = "BROADCAST",
2773 [RTN_ANYCAST] = "ANYCAST",
2774 [RTN_MULTICAST] = "MULTICAST",
2775 [RTN_BLACKHOLE] = "BLACKHOLE",
2776 [RTN_UNREACHABLE] = "UNREACHABLE",
2777 [RTN_PROHIBIT] = "PROHIBIT",
2778 [RTN_THROW] = "THROW",
2779 [RTN_NAT] = "NAT",
2780 [RTN_XRESOLVE] = "XRESOLVE",
2781};
2782
2783static inline const char *rtn_type(char *buf, size_t len, unsigned int t)
2784{
2785 if (t < __RTN_MAX && rtn_type_names[t])
2786 return rtn_type_names[t];
2787 snprintf(buf, len, "type %u", t);
2788 return buf;
2789}
2790
2791/* Pretty print the trie */
2792static int fib_trie_seq_show(struct seq_file *seq, void *v)
2793{
2794 const struct fib_trie_iter *iter = seq->private;
2795 struct key_vector *n = v;
2796
2797 if (IS_TRIE(node_parent_rcu(n)))
2798 fib_table_print(seq, iter->tb);
2799
2800 if (IS_TNODE(n)) {
2801 __be32 prf = htonl(n->key);
2802
2803 seq_indent(seq, iter->depth-1);
2804 seq_printf(seq, " +-- %pI4/%zu %u %u %u\n",
2805 &prf, KEYLENGTH - n->pos - n->bits, n->bits,
2806 tn_info(n)->full_children,
2807 tn_info(n)->empty_children);
2808 } else {
2809 __be32 val = htonl(n->key);
2810 struct fib_alias *fa;
2811
2812 seq_indent(seq, iter->depth);
2813 seq_printf(seq, " |-- %pI4\n", &val);
2814
2815 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
2816 char buf1[32], buf2[32];
2817
2818 seq_indent(seq, iter->depth + 1);
2819 seq_printf(seq, " /%zu %s %s",
2820 KEYLENGTH - fa->fa_slen,
2821 rtn_scope(buf1, sizeof(buf1),
2822 fa->fa_info->fib_scope),
2823 rtn_type(buf2, sizeof(buf2),
2824 fa->fa_type));
2825 if (fa->fa_dscp)
2826 seq_printf(seq, " tos=%d",
2827 inet_dscp_to_dsfield(fa->fa_dscp));
2828 seq_putc(seq, '\n');
2829 }
2830 }
2831
2832 return 0;
2833}
2834
2835static const struct seq_operations fib_trie_seq_ops = {
2836 .start = fib_trie_seq_start,
2837 .next = fib_trie_seq_next,
2838 .stop = fib_trie_seq_stop,
2839 .show = fib_trie_seq_show,
2840};
2841
2842struct fib_route_iter {
2843 struct seq_net_private p;
2844 struct fib_table *main_tb;
2845 struct key_vector *tnode;
2846 loff_t pos;
2847 t_key key;
2848};
2849
2850static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter,
2851 loff_t pos)
2852{
2853 struct key_vector *l, **tp = &iter->tnode;
2854 t_key key;
2855
2856 /* use cached location of previously found key */
2857 if (iter->pos > 0 && pos >= iter->pos) {
2858 key = iter->key;
2859 } else {
2860 iter->pos = 1;
2861 key = 0;
2862 }
2863
2864 pos -= iter->pos;
2865
2866 while ((l = leaf_walk_rcu(tp, key)) && (pos-- > 0)) {
2867 key = l->key + 1;
2868 iter->pos++;
2869 l = NULL;
2870
2871 /* handle unlikely case of a key wrap */
2872 if (!key)
2873 break;
2874 }
2875
2876 if (l)
2877 iter->key = l->key; /* remember it */
2878 else
2879 iter->pos = 0; /* forget it */
2880
2881 return l;
2882}
2883
2884static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos)
2885 __acquires(RCU)
2886{
2887 struct fib_route_iter *iter = seq->private;
2888 struct fib_table *tb;
2889 struct trie *t;
2890
2891 rcu_read_lock();
2892
2893 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
2894 if (!tb)
2895 return NULL;
2896
2897 iter->main_tb = tb;
2898 t = (struct trie *)tb->tb_data;
2899 iter->tnode = t->kv;
2900
2901 if (*pos != 0)
2902 return fib_route_get_idx(iter, *pos);
2903
2904 iter->pos = 0;
2905 iter->key = KEY_MAX;
2906
2907 return SEQ_START_TOKEN;
2908}
2909
2910static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2911{
2912 struct fib_route_iter *iter = seq->private;
2913 struct key_vector *l = NULL;
2914 t_key key = iter->key + 1;
2915
2916 ++*pos;
2917
2918 /* only allow key of 0 for start of sequence */
2919 if ((v == SEQ_START_TOKEN) || key)
2920 l = leaf_walk_rcu(&iter->tnode, key);
2921
2922 if (l) {
2923 iter->key = l->key;
2924 iter->pos++;
2925 } else {
2926 iter->pos = 0;
2927 }
2928
2929 return l;
2930}
2931
2932static void fib_route_seq_stop(struct seq_file *seq, void *v)
2933 __releases(RCU)
2934{
2935 rcu_read_unlock();
2936}
2937
2938static unsigned int fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
2939{
2940 unsigned int flags = 0;
2941
2942 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT)
2943 flags = RTF_REJECT;
2944 if (fi) {
2945 const struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
2946
2947 if (nhc->nhc_gw.ipv4)
2948 flags |= RTF_GATEWAY;
2949 }
2950 if (mask == htonl(0xFFFFFFFF))
2951 flags |= RTF_HOST;
2952 flags |= RTF_UP;
2953 return flags;
2954}
2955
2956/*
2957 * This outputs /proc/net/route.
2958 * The format of the file is not supposed to be changed
2959 * and needs to be same as fib_hash output to avoid breaking
2960 * legacy utilities
2961 */
2962static int fib_route_seq_show(struct seq_file *seq, void *v)
2963{
2964 struct fib_route_iter *iter = seq->private;
2965 struct fib_table *tb = iter->main_tb;
2966 struct fib_alias *fa;
2967 struct key_vector *l = v;
2968 __be32 prefix;
2969
2970 if (v == SEQ_START_TOKEN) {
2971 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
2972 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
2973 "\tWindow\tIRTT");
2974 return 0;
2975 }
2976
2977 prefix = htonl(l->key);
2978
2979 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2980 struct fib_info *fi = fa->fa_info;
2981 __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen);
2982 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);
2983
2984 if ((fa->fa_type == RTN_BROADCAST) ||
2985 (fa->fa_type == RTN_MULTICAST))
2986 continue;
2987
2988 if (fa->tb_id != tb->tb_id)
2989 continue;
2990
2991 seq_setwidth(seq, 127);
2992
2993 if (fi) {
2994 struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
2995 __be32 gw = 0;
2996
2997 if (nhc->nhc_gw_family == AF_INET)
2998 gw = nhc->nhc_gw.ipv4;
2999
3000 seq_printf(seq,
3001 "%s\t%08X\t%08X\t%04X\t%d\t%u\t"
3002 "%d\t%08X\t%d\t%u\t%u",
3003 nhc->nhc_dev ? nhc->nhc_dev->name : "*",
3004 prefix, gw, flags, 0, 0,
3005 fi->fib_priority,
3006 mask,
3007 (fi->fib_advmss ?
3008 fi->fib_advmss + 40 : 0),
3009 fi->fib_window,
3010 fi->fib_rtt >> 3);
3011 } else {
3012 seq_printf(seq,
3013 "*\t%08X\t%08X\t%04X\t%d\t%u\t"
3014 "%d\t%08X\t%d\t%u\t%u",
3015 prefix, 0, flags, 0, 0, 0,
3016 mask, 0, 0, 0);
3017 }
3018 seq_pad(seq, '\n');
3019 }
3020
3021 return 0;
3022}
3023
3024static const struct seq_operations fib_route_seq_ops = {
3025 .start = fib_route_seq_start,
3026 .next = fib_route_seq_next,
3027 .stop = fib_route_seq_stop,
3028 .show = fib_route_seq_show,
3029};
3030
3031int __net_init fib_proc_init(struct net *net)
3032{
3033 if (!proc_create_net("fib_trie", 0444, net->proc_net, &fib_trie_seq_ops,
3034 sizeof(struct fib_trie_iter)))
3035 goto out1;
3036
3037 if (!proc_create_net_single("fib_triestat", 0444, net->proc_net,
3038 fib_triestat_seq_show, NULL))
3039 goto out2;
3040
3041 if (!proc_create_net("route", 0444, net->proc_net, &fib_route_seq_ops,
3042 sizeof(struct fib_route_iter)))
3043 goto out3;
3044
3045 return 0;
3046
3047out3:
3048 remove_proc_entry("fib_triestat", net->proc_net);
3049out2:
3050 remove_proc_entry("fib_trie", net->proc_net);
3051out1:
3052 return -ENOMEM;
3053}
3054
3055void __net_exit fib_proc_exit(struct net *net)
3056{
3057 remove_proc_entry("fib_trie", net->proc_net);
3058 remove_proc_entry("fib_triestat", net->proc_net);
3059 remove_proc_entry("route", net->proc_net);
3060}
3061
3062#endif /* CONFIG_PROC_FS */