Loading...
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/rcupdate_wait.h>
56#include <linux/skbuff.h>
57#include <linux/netlink.h>
58#include <linux/init.h>
59#include <linux/list.h>
60#include <linux/slab.h>
61#include <linux/export.h>
62#include <linux/vmalloc.h>
63#include <linux/notifier.h>
64#include <net/net_namespace.h>
65#include <net/inet_dscp.h>
66#include <net/ip.h>
67#include <net/protocol.h>
68#include <net/route.h>
69#include <net/tcp.h>
70#include <net/sock.h>
71#include <net/ip_fib.h>
72#include <net/fib_notifier.h>
73#include <trace/events/fib.h>
74#include "fib_lookup.h"
75
76static int call_fib_entry_notifier(struct notifier_block *nb,
77 enum fib_event_type event_type, u32 dst,
78 int dst_len, struct fib_alias *fa,
79 struct netlink_ext_ack *extack)
80{
81 struct fib_entry_notifier_info info = {
82 .info.extack = extack,
83 .dst = dst,
84 .dst_len = dst_len,
85 .fi = fa->fa_info,
86 .dscp = fa->fa_dscp,
87 .type = fa->fa_type,
88 .tb_id = fa->tb_id,
89 };
90 return call_fib4_notifier(nb, event_type, &info.info);
91}
92
93static int call_fib_entry_notifiers(struct net *net,
94 enum fib_event_type event_type, u32 dst,
95 int dst_len, struct fib_alias *fa,
96 struct netlink_ext_ack *extack)
97{
98 struct fib_entry_notifier_info info = {
99 .info.extack = extack,
100 .dst = dst,
101 .dst_len = dst_len,
102 .fi = fa->fa_info,
103 .dscp = fa->fa_dscp,
104 .type = fa->fa_type,
105 .tb_id = fa->tb_id,
106 };
107 return call_fib4_notifiers(net, event_type, &info.info);
108}
109
110#define MAX_STAT_DEPTH 32
111
112#define KEYLENGTH (8*sizeof(t_key))
113#define KEY_MAX ((t_key)~0)
114
115typedef unsigned int t_key;
116
117#define IS_TRIE(n) ((n)->pos >= KEYLENGTH)
118#define IS_TNODE(n) ((n)->bits)
119#define IS_LEAF(n) (!(n)->bits)
120
121struct key_vector {
122 t_key key;
123 unsigned char pos; /* 2log(KEYLENGTH) bits needed */
124 unsigned char bits; /* 2log(KEYLENGTH) bits needed */
125 unsigned char slen;
126 union {
127 /* This list pointer if valid if (pos | bits) == 0 (LEAF) */
128 struct hlist_head leaf;
129 /* This array is valid if (pos | bits) > 0 (TNODE) */
130 DECLARE_FLEX_ARRAY(struct key_vector __rcu *, tnode);
131 };
132};
133
134struct tnode {
135 struct rcu_head rcu;
136 t_key empty_children; /* KEYLENGTH bits needed */
137 t_key full_children; /* KEYLENGTH bits needed */
138 struct key_vector __rcu *parent;
139 struct key_vector kv[1];
140#define tn_bits kv[0].bits
141};
142
143#define TNODE_SIZE(n) offsetof(struct tnode, kv[0].tnode[n])
144#define LEAF_SIZE TNODE_SIZE(1)
145
146#ifdef CONFIG_IP_FIB_TRIE_STATS
147struct trie_use_stats {
148 unsigned int gets;
149 unsigned int backtrack;
150 unsigned int semantic_match_passed;
151 unsigned int semantic_match_miss;
152 unsigned int null_node_hit;
153 unsigned int resize_node_skipped;
154};
155#endif
156
157struct trie_stat {
158 unsigned int totdepth;
159 unsigned int maxdepth;
160 unsigned int tnodes;
161 unsigned int leaves;
162 unsigned int nullpointers;
163 unsigned int prefixes;
164 unsigned int nodesizes[MAX_STAT_DEPTH];
165};
166
167struct trie {
168 struct key_vector kv[1];
169#ifdef CONFIG_IP_FIB_TRIE_STATS
170 struct trie_use_stats __percpu *stats;
171#endif
172};
173
174static struct key_vector *resize(struct trie *t, struct key_vector *tn);
175static unsigned int tnode_free_size;
176
177/*
178 * synchronize_rcu after call_rcu for outstanding dirty memory; it should be
179 * especially useful before resizing the root node with PREEMPT_NONE configs;
180 * the value was obtained experimentally, aiming to avoid visible slowdown.
181 */
182unsigned int sysctl_fib_sync_mem = 512 * 1024;
183unsigned int sysctl_fib_sync_mem_min = 64 * 1024;
184unsigned int sysctl_fib_sync_mem_max = 64 * 1024 * 1024;
185
186static struct kmem_cache *fn_alias_kmem __ro_after_init;
187static struct kmem_cache *trie_leaf_kmem __ro_after_init;
188
189static inline struct tnode *tn_info(struct key_vector *kv)
190{
191 return container_of(kv, struct tnode, kv[0]);
192}
193
194/* caller must hold RTNL */
195#define node_parent(tn) rtnl_dereference(tn_info(tn)->parent)
196#define get_child(tn, i) rtnl_dereference((tn)->tnode[i])
197
198/* caller must hold RCU read lock or RTNL */
199#define node_parent_rcu(tn) rcu_dereference_rtnl(tn_info(tn)->parent)
200#define get_child_rcu(tn, i) rcu_dereference_rtnl((tn)->tnode[i])
201
202/* wrapper for rcu_assign_pointer */
203static inline void node_set_parent(struct key_vector *n, struct key_vector *tp)
204{
205 if (n)
206 rcu_assign_pointer(tn_info(n)->parent, tp);
207}
208
209#define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER(tn_info(n)->parent, p)
210
211/* This provides us with the number of children in this node, in the case of a
212 * leaf this will return 0 meaning none of the children are accessible.
213 */
214static inline unsigned long child_length(const struct key_vector *tn)
215{
216 return (1ul << tn->bits) & ~(1ul);
217}
218
219#define get_cindex(key, kv) (((key) ^ (kv)->key) >> (kv)->pos)
220
221static inline unsigned long get_index(t_key key, struct key_vector *kv)
222{
223 unsigned long index = key ^ kv->key;
224
225 if ((BITS_PER_LONG <= KEYLENGTH) && (KEYLENGTH == kv->pos))
226 return 0;
227
228 return index >> kv->pos;
229}
230
231/* To understand this stuff, an understanding of keys and all their bits is
232 * necessary. Every node in the trie has a key associated with it, but not
233 * all of the bits in that key are significant.
234 *
235 * Consider a node 'n' and its parent 'tp'.
236 *
237 * If n is a leaf, every bit in its key is significant. Its presence is
238 * necessitated by path compression, since during a tree traversal (when
239 * searching for a leaf - unless we are doing an insertion) we will completely
240 * ignore all skipped bits we encounter. Thus we need to verify, at the end of
241 * a potentially successful search, that we have indeed been walking the
242 * correct key path.
243 *
244 * Note that we can never "miss" the correct key in the tree if present by
245 * following the wrong path. Path compression ensures that segments of the key
246 * that are the same for all keys with a given prefix are skipped, but the
247 * skipped part *is* identical for each node in the subtrie below the skipped
248 * bit! trie_insert() in this implementation takes care of that.
249 *
250 * if n is an internal node - a 'tnode' here, the various parts of its key
251 * have many different meanings.
252 *
253 * Example:
254 * _________________________________________________________________
255 * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
256 * -----------------------------------------------------------------
257 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
258 *
259 * _________________________________________________________________
260 * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
261 * -----------------------------------------------------------------
262 * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
263 *
264 * tp->pos = 22
265 * tp->bits = 3
266 * n->pos = 13
267 * n->bits = 4
268 *
269 * First, let's just ignore the bits that come before the parent tp, that is
270 * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this
271 * point we do not use them for anything.
272 *
273 * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the
274 * index into the parent's child array. That is, they will be used to find
275 * 'n' among tp's children.
276 *
277 * The bits from (n->pos + n->bits) to (tp->pos - 1) - "S" - are skipped bits
278 * for the node n.
279 *
280 * All the bits we have seen so far are significant to the node n. The rest
281 * of the bits are really not needed or indeed known in n->key.
282 *
283 * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into
284 * n's child array, and will of course be different for each child.
285 *
286 * The rest of the bits, from 0 to (n->pos -1) - "u" - are completely unknown
287 * at this point.
288 */
289
290static const int halve_threshold = 25;
291static const int inflate_threshold = 50;
292static const int halve_threshold_root = 15;
293static const int inflate_threshold_root = 30;
294
295static void __alias_free_mem(struct rcu_head *head)
296{
297 struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
298 kmem_cache_free(fn_alias_kmem, fa);
299}
300
301static inline void alias_free_mem_rcu(struct fib_alias *fa)
302{
303 call_rcu(&fa->rcu, __alias_free_mem);
304}
305
306#define TNODE_VMALLOC_MAX \
307 ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *))
308
309static void __node_free_rcu(struct rcu_head *head)
310{
311 struct tnode *n = container_of(head, struct tnode, rcu);
312
313 if (!n->tn_bits)
314 kmem_cache_free(trie_leaf_kmem, n);
315 else
316 kvfree(n);
317}
318
319#define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu)
320
321static struct tnode *tnode_alloc(int bits)
322{
323 size_t size;
324
325 /* verify bits is within bounds */
326 if (bits > TNODE_VMALLOC_MAX)
327 return NULL;
328
329 /* determine size and verify it is non-zero and didn't overflow */
330 size = TNODE_SIZE(1ul << bits);
331
332 if (size <= PAGE_SIZE)
333 return kzalloc(size, GFP_KERNEL);
334 else
335 return vzalloc(size);
336}
337
338static inline void empty_child_inc(struct key_vector *n)
339{
340 tn_info(n)->empty_children++;
341
342 if (!tn_info(n)->empty_children)
343 tn_info(n)->full_children++;
344}
345
346static inline void empty_child_dec(struct key_vector *n)
347{
348 if (!tn_info(n)->empty_children)
349 tn_info(n)->full_children--;
350
351 tn_info(n)->empty_children--;
352}
353
354static struct key_vector *leaf_new(t_key key, struct fib_alias *fa)
355{
356 struct key_vector *l;
357 struct tnode *kv;
358
359 kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
360 if (!kv)
361 return NULL;
362
363 /* initialize key vector */
364 l = kv->kv;
365 l->key = key;
366 l->pos = 0;
367 l->bits = 0;
368 l->slen = fa->fa_slen;
369
370 /* link leaf to fib alias */
371 INIT_HLIST_HEAD(&l->leaf);
372 hlist_add_head(&fa->fa_list, &l->leaf);
373
374 return l;
375}
376
377static struct key_vector *tnode_new(t_key key, int pos, int bits)
378{
379 unsigned int shift = pos + bits;
380 struct key_vector *tn;
381 struct tnode *tnode;
382
383 /* verify bits and pos their msb bits clear and values are valid */
384 BUG_ON(!bits || (shift > KEYLENGTH));
385
386 tnode = tnode_alloc(bits);
387 if (!tnode)
388 return NULL;
389
390 pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0),
391 sizeof(struct key_vector *) << bits);
392
393 if (bits == KEYLENGTH)
394 tnode->full_children = 1;
395 else
396 tnode->empty_children = 1ul << bits;
397
398 tn = tnode->kv;
399 tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
400 tn->pos = pos;
401 tn->bits = bits;
402 tn->slen = pos;
403
404 return tn;
405}
406
407/* Check whether a tnode 'n' is "full", i.e. it is an internal node
408 * and no bits are skipped. See discussion in dyntree paper p. 6
409 */
410static inline int tnode_full(struct key_vector *tn, struct key_vector *n)
411{
412 return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n);
413}
414
415/* Add a child at position i overwriting the old value.
416 * Update the value of full_children and empty_children.
417 */
418static void put_child(struct key_vector *tn, unsigned long i,
419 struct key_vector *n)
420{
421 struct key_vector *chi = get_child(tn, i);
422 int isfull, wasfull;
423
424 BUG_ON(i >= child_length(tn));
425
426 /* update emptyChildren, overflow into fullChildren */
427 if (!n && chi)
428 empty_child_inc(tn);
429 if (n && !chi)
430 empty_child_dec(tn);
431
432 /* update fullChildren */
433 wasfull = tnode_full(tn, chi);
434 isfull = tnode_full(tn, n);
435
436 if (wasfull && !isfull)
437 tn_info(tn)->full_children--;
438 else if (!wasfull && isfull)
439 tn_info(tn)->full_children++;
440
441 if (n && (tn->slen < n->slen))
442 tn->slen = n->slen;
443
444 rcu_assign_pointer(tn->tnode[i], n);
445}
446
447static void update_children(struct key_vector *tn)
448{
449 unsigned long i;
450
451 /* update all of the child parent pointers */
452 for (i = child_length(tn); i;) {
453 struct key_vector *inode = get_child(tn, --i);
454
455 if (!inode)
456 continue;
457
458 /* Either update the children of a tnode that
459 * already belongs to us or update the child
460 * to point to ourselves.
461 */
462 if (node_parent(inode) == tn)
463 update_children(inode);
464 else
465 node_set_parent(inode, tn);
466 }
467}
468
469static inline void put_child_root(struct key_vector *tp, t_key key,
470 struct key_vector *n)
471{
472 if (IS_TRIE(tp))
473 rcu_assign_pointer(tp->tnode[0], n);
474 else
475 put_child(tp, get_index(key, tp), n);
476}
477
478static inline void tnode_free_init(struct key_vector *tn)
479{
480 tn_info(tn)->rcu.next = NULL;
481}
482
483static inline void tnode_free_append(struct key_vector *tn,
484 struct key_vector *n)
485{
486 tn_info(n)->rcu.next = tn_info(tn)->rcu.next;
487 tn_info(tn)->rcu.next = &tn_info(n)->rcu;
488}
489
490static void tnode_free(struct key_vector *tn)
491{
492 struct callback_head *head = &tn_info(tn)->rcu;
493
494 while (head) {
495 head = head->next;
496 tnode_free_size += TNODE_SIZE(1ul << tn->bits);
497 node_free(tn);
498
499 tn = container_of(head, struct tnode, rcu)->kv;
500 }
501
502 if (tnode_free_size >= READ_ONCE(sysctl_fib_sync_mem)) {
503 tnode_free_size = 0;
504 synchronize_rcu();
505 }
506}
507
508static struct key_vector *replace(struct trie *t,
509 struct key_vector *oldtnode,
510 struct key_vector *tn)
511{
512 struct key_vector *tp = node_parent(oldtnode);
513 unsigned long i;
514
515 /* setup the parent pointer out of and back into this node */
516 NODE_INIT_PARENT(tn, tp);
517 put_child_root(tp, tn->key, tn);
518
519 /* update all of the child parent pointers */
520 update_children(tn);
521
522 /* all pointers should be clean so we are done */
523 tnode_free(oldtnode);
524
525 /* resize children now that oldtnode is freed */
526 for (i = child_length(tn); i;) {
527 struct key_vector *inode = get_child(tn, --i);
528
529 /* resize child node */
530 if (tnode_full(tn, inode))
531 tn = resize(t, inode);
532 }
533
534 return tp;
535}
536
537static struct key_vector *inflate(struct trie *t,
538 struct key_vector *oldtnode)
539{
540 struct key_vector *tn;
541 unsigned long i;
542 t_key m;
543
544 pr_debug("In inflate\n");
545
546 tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1);
547 if (!tn)
548 goto notnode;
549
550 /* prepare oldtnode to be freed */
551 tnode_free_init(oldtnode);
552
553 /* Assemble all of the pointers in our cluster, in this case that
554 * represents all of the pointers out of our allocated nodes that
555 * point to existing tnodes and the links between our allocated
556 * nodes.
557 */
558 for (i = child_length(oldtnode), m = 1u << tn->pos; i;) {
559 struct key_vector *inode = get_child(oldtnode, --i);
560 struct key_vector *node0, *node1;
561 unsigned long j, k;
562
563 /* An empty child */
564 if (!inode)
565 continue;
566
567 /* A leaf or an internal node with skipped bits */
568 if (!tnode_full(oldtnode, inode)) {
569 put_child(tn, get_index(inode->key, tn), inode);
570 continue;
571 }
572
573 /* drop the node in the old tnode free list */
574 tnode_free_append(oldtnode, inode);
575
576 /* An internal node with two children */
577 if (inode->bits == 1) {
578 put_child(tn, 2 * i + 1, get_child(inode, 1));
579 put_child(tn, 2 * i, get_child(inode, 0));
580 continue;
581 }
582
583 /* We will replace this node 'inode' with two new
584 * ones, 'node0' and 'node1', each with half of the
585 * original children. The two new nodes will have
586 * a position one bit further down the key and this
587 * means that the "significant" part of their keys
588 * (see the discussion near the top of this file)
589 * will differ by one bit, which will be "0" in
590 * node0's key and "1" in node1's key. Since we are
591 * moving the key position by one step, the bit that
592 * we are moving away from - the bit at position
593 * (tn->pos) - is the one that will differ between
594 * node0 and node1. So... we synthesize that bit in the
595 * two new keys.
596 */
597 node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1);
598 if (!node1)
599 goto nomem;
600 node0 = tnode_new(inode->key, inode->pos, inode->bits - 1);
601
602 tnode_free_append(tn, node1);
603 if (!node0)
604 goto nomem;
605 tnode_free_append(tn, node0);
606
607 /* populate child pointers in new nodes */
608 for (k = child_length(inode), j = k / 2; j;) {
609 put_child(node1, --j, get_child(inode, --k));
610 put_child(node0, j, get_child(inode, j));
611 put_child(node1, --j, get_child(inode, --k));
612 put_child(node0, j, get_child(inode, j));
613 }
614
615 /* link new nodes to parent */
616 NODE_INIT_PARENT(node1, tn);
617 NODE_INIT_PARENT(node0, tn);
618
619 /* link parent to nodes */
620 put_child(tn, 2 * i + 1, node1);
621 put_child(tn, 2 * i, node0);
622 }
623
624 /* setup the parent pointers into and out of this node */
625 return replace(t, oldtnode, tn);
626nomem:
627 /* all pointers should be clean so we are done */
628 tnode_free(tn);
629notnode:
630 return NULL;
631}
632
633static struct key_vector *halve(struct trie *t,
634 struct key_vector *oldtnode)
635{
636 struct key_vector *tn;
637 unsigned long i;
638
639 pr_debug("In halve\n");
640
641 tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1);
642 if (!tn)
643 goto notnode;
644
645 /* prepare oldtnode to be freed */
646 tnode_free_init(oldtnode);
647
648 /* Assemble all of the pointers in our cluster, in this case that
649 * represents all of the pointers out of our allocated nodes that
650 * point to existing tnodes and the links between our allocated
651 * nodes.
652 */
653 for (i = child_length(oldtnode); i;) {
654 struct key_vector *node1 = get_child(oldtnode, --i);
655 struct key_vector *node0 = get_child(oldtnode, --i);
656 struct key_vector *inode;
657
658 /* At least one of the children is empty */
659 if (!node1 || !node0) {
660 put_child(tn, i / 2, node1 ? : node0);
661 continue;
662 }
663
664 /* Two nonempty children */
665 inode = tnode_new(node0->key, oldtnode->pos, 1);
666 if (!inode)
667 goto nomem;
668 tnode_free_append(tn, inode);
669
670 /* initialize pointers out of node */
671 put_child(inode, 1, node1);
672 put_child(inode, 0, node0);
673 NODE_INIT_PARENT(inode, tn);
674
675 /* link parent to node */
676 put_child(tn, i / 2, inode);
677 }
678
679 /* setup the parent pointers into and out of this node */
680 return replace(t, oldtnode, tn);
681nomem:
682 /* all pointers should be clean so we are done */
683 tnode_free(tn);
684notnode:
685 return NULL;
686}
687
688static struct key_vector *collapse(struct trie *t,
689 struct key_vector *oldtnode)
690{
691 struct key_vector *n, *tp;
692 unsigned long i;
693
694 /* scan the tnode looking for that one child that might still exist */
695 for (n = NULL, i = child_length(oldtnode); !n && i;)
696 n = get_child(oldtnode, --i);
697
698 /* compress one level */
699 tp = node_parent(oldtnode);
700 put_child_root(tp, oldtnode->key, n);
701 node_set_parent(n, tp);
702
703 /* drop dead node */
704 node_free(oldtnode);
705
706 return tp;
707}
708
709static unsigned char update_suffix(struct key_vector *tn)
710{
711 unsigned char slen = tn->pos;
712 unsigned long stride, i;
713 unsigned char slen_max;
714
715 /* only vector 0 can have a suffix length greater than or equal to
716 * tn->pos + tn->bits, the second highest node will have a suffix
717 * length at most of tn->pos + tn->bits - 1
718 */
719 slen_max = min_t(unsigned char, tn->pos + tn->bits - 1, tn->slen);
720
721 /* search though the list of children looking for nodes that might
722 * have a suffix greater than the one we currently have. This is
723 * why we start with a stride of 2 since a stride of 1 would
724 * represent the nodes with suffix length equal to tn->pos
725 */
726 for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) {
727 struct key_vector *n = get_child(tn, i);
728
729 if (!n || (n->slen <= slen))
730 continue;
731
732 /* update stride and slen based on new value */
733 stride <<= (n->slen - slen);
734 slen = n->slen;
735 i &= ~(stride - 1);
736
737 /* stop searching if we have hit the maximum possible value */
738 if (slen >= slen_max)
739 break;
740 }
741
742 tn->slen = slen;
743
744 return slen;
745}
746
747/* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
748 * the Helsinki University of Technology and Matti Tikkanen of Nokia
749 * Telecommunications, page 6:
750 * "A node is doubled if the ratio of non-empty children to all
751 * children in the *doubled* node is at least 'high'."
752 *
753 * 'high' in this instance is the variable 'inflate_threshold'. It
754 * is expressed as a percentage, so we multiply it with
755 * child_length() and instead of multiplying by 2 (since the
756 * child array will be doubled by inflate()) and multiplying
757 * the left-hand side by 100 (to handle the percentage thing) we
758 * multiply the left-hand side by 50.
759 *
760 * The left-hand side may look a bit weird: child_length(tn)
761 * - tn->empty_children is of course the number of non-null children
762 * in the current node. tn->full_children is the number of "full"
763 * children, that is non-null tnodes with a skip value of 0.
764 * All of those will be doubled in the resulting inflated tnode, so
765 * we just count them one extra time here.
766 *
767 * A clearer way to write this would be:
768 *
769 * to_be_doubled = tn->full_children;
770 * not_to_be_doubled = child_length(tn) - tn->empty_children -
771 * tn->full_children;
772 *
773 * new_child_length = child_length(tn) * 2;
774 *
775 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
776 * new_child_length;
777 * if (new_fill_factor >= inflate_threshold)
778 *
779 * ...and so on, tho it would mess up the while () loop.
780 *
781 * anyway,
782 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
783 * inflate_threshold
784 *
785 * avoid a division:
786 * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
787 * inflate_threshold * new_child_length
788 *
789 * expand not_to_be_doubled and to_be_doubled, and shorten:
790 * 100 * (child_length(tn) - tn->empty_children +
791 * tn->full_children) >= inflate_threshold * new_child_length
792 *
793 * expand new_child_length:
794 * 100 * (child_length(tn) - tn->empty_children +
795 * tn->full_children) >=
796 * inflate_threshold * child_length(tn) * 2
797 *
798 * shorten again:
799 * 50 * (tn->full_children + child_length(tn) -
800 * tn->empty_children) >= inflate_threshold *
801 * child_length(tn)
802 *
803 */
804static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn)
805{
806 unsigned long used = child_length(tn);
807 unsigned long threshold = used;
808
809 /* Keep root node larger */
810 threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold;
811 used -= tn_info(tn)->empty_children;
812 used += tn_info(tn)->full_children;
813
814 /* if bits == KEYLENGTH then pos = 0, and will fail below */
815
816 return (used > 1) && tn->pos && ((50 * used) >= threshold);
817}
818
819static inline bool should_halve(struct key_vector *tp, struct key_vector *tn)
820{
821 unsigned long used = child_length(tn);
822 unsigned long threshold = used;
823
824 /* Keep root node larger */
825 threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold;
826 used -= tn_info(tn)->empty_children;
827
828 /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */
829
830 return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold);
831}
832
833static inline bool should_collapse(struct key_vector *tn)
834{
835 unsigned long used = child_length(tn);
836
837 used -= tn_info(tn)->empty_children;
838
839 /* account for bits == KEYLENGTH case */
840 if ((tn->bits == KEYLENGTH) && tn_info(tn)->full_children)
841 used -= KEY_MAX;
842
843 /* One child or none, time to drop us from the trie */
844 return used < 2;
845}
846
847#define MAX_WORK 10
848static struct key_vector *resize(struct trie *t, struct key_vector *tn)
849{
850#ifdef CONFIG_IP_FIB_TRIE_STATS
851 struct trie_use_stats __percpu *stats = t->stats;
852#endif
853 struct key_vector *tp = node_parent(tn);
854 unsigned long cindex = get_index(tn->key, tp);
855 int max_work = MAX_WORK;
856
857 pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
858 tn, inflate_threshold, halve_threshold);
859
860 /* track the tnode via the pointer from the parent instead of
861 * doing it ourselves. This way we can let RCU fully do its
862 * thing without us interfering
863 */
864 BUG_ON(tn != get_child(tp, cindex));
865
866 /* Double as long as the resulting node has a number of
867 * nonempty nodes that are above the threshold.
868 */
869 while (should_inflate(tp, tn) && max_work) {
870 tp = inflate(t, tn);
871 if (!tp) {
872#ifdef CONFIG_IP_FIB_TRIE_STATS
873 this_cpu_inc(stats->resize_node_skipped);
874#endif
875 break;
876 }
877
878 max_work--;
879 tn = get_child(tp, cindex);
880 }
881
882 /* update parent in case inflate failed */
883 tp = node_parent(tn);
884
885 /* Return if at least one inflate is run */
886 if (max_work != MAX_WORK)
887 return tp;
888
889 /* Halve as long as the number of empty children in this
890 * node is above threshold.
891 */
892 while (should_halve(tp, tn) && max_work) {
893 tp = halve(t, tn);
894 if (!tp) {
895#ifdef CONFIG_IP_FIB_TRIE_STATS
896 this_cpu_inc(stats->resize_node_skipped);
897#endif
898 break;
899 }
900
901 max_work--;
902 tn = get_child(tp, cindex);
903 }
904
905 /* Only one child remains */
906 if (should_collapse(tn))
907 return collapse(t, tn);
908
909 /* update parent in case halve failed */
910 return node_parent(tn);
911}
912
913static void node_pull_suffix(struct key_vector *tn, unsigned char slen)
914{
915 unsigned char node_slen = tn->slen;
916
917 while ((node_slen > tn->pos) && (node_slen > slen)) {
918 slen = update_suffix(tn);
919 if (node_slen == slen)
920 break;
921
922 tn = node_parent(tn);
923 node_slen = tn->slen;
924 }
925}
926
927static void node_push_suffix(struct key_vector *tn, unsigned char slen)
928{
929 while (tn->slen < slen) {
930 tn->slen = slen;
931 tn = node_parent(tn);
932 }
933}
934
935/* rcu_read_lock needs to be hold by caller from readside */
936static struct key_vector *fib_find_node(struct trie *t,
937 struct key_vector **tp, u32 key)
938{
939 struct key_vector *pn, *n = t->kv;
940 unsigned long index = 0;
941
942 do {
943 pn = n;
944 n = get_child_rcu(n, index);
945
946 if (!n)
947 break;
948
949 index = get_cindex(key, n);
950
951 /* This bit of code is a bit tricky but it combines multiple
952 * checks into a single check. The prefix consists of the
953 * prefix plus zeros for the bits in the cindex. The index
954 * is the difference between the key and this value. From
955 * this we can actually derive several pieces of data.
956 * if (index >= (1ul << bits))
957 * we have a mismatch in skip bits and failed
958 * else
959 * we know the value is cindex
960 *
961 * This check is safe even if bits == KEYLENGTH due to the
962 * fact that we can only allocate a node with 32 bits if a
963 * long is greater than 32 bits.
964 */
965 if (index >= (1ul << n->bits)) {
966 n = NULL;
967 break;
968 }
969
970 /* keep searching until we find a perfect match leaf or NULL */
971 } while (IS_TNODE(n));
972
973 *tp = pn;
974
975 return n;
976}
977
978/* Return the first fib alias matching DSCP with
979 * priority less than or equal to PRIO.
980 * If 'find_first' is set, return the first matching
981 * fib alias, regardless of DSCP and priority.
982 */
983static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen,
984 dscp_t dscp, u32 prio, u32 tb_id,
985 bool find_first)
986{
987 struct fib_alias *fa;
988
989 if (!fah)
990 return NULL;
991
992 hlist_for_each_entry(fa, fah, fa_list) {
993 /* Avoid Sparse warning when using dscp_t in inequalities */
994 u8 __fa_dscp = inet_dscp_to_dsfield(fa->fa_dscp);
995 u8 __dscp = inet_dscp_to_dsfield(dscp);
996
997 if (fa->fa_slen < slen)
998 continue;
999 if (fa->fa_slen != slen)
1000 break;
1001 if (fa->tb_id > tb_id)
1002 continue;
1003 if (fa->tb_id != tb_id)
1004 break;
1005 if (find_first)
1006 return fa;
1007 if (__fa_dscp > __dscp)
1008 continue;
1009 if (fa->fa_info->fib_priority >= prio || __fa_dscp < __dscp)
1010 return fa;
1011 }
1012
1013 return NULL;
1014}
1015
1016static struct fib_alias *
1017fib_find_matching_alias(struct net *net, const struct fib_rt_info *fri)
1018{
1019 u8 slen = KEYLENGTH - fri->dst_len;
1020 struct key_vector *l, *tp;
1021 struct fib_table *tb;
1022 struct fib_alias *fa;
1023 struct trie *t;
1024
1025 tb = fib_get_table(net, fri->tb_id);
1026 if (!tb)
1027 return NULL;
1028
1029 t = (struct trie *)tb->tb_data;
1030 l = fib_find_node(t, &tp, be32_to_cpu(fri->dst));
1031 if (!l)
1032 return NULL;
1033
1034 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
1035 if (fa->fa_slen == slen && fa->tb_id == fri->tb_id &&
1036 fa->fa_dscp == fri->dscp && fa->fa_info == fri->fi &&
1037 fa->fa_type == fri->type)
1038 return fa;
1039 }
1040
1041 return NULL;
1042}
1043
1044void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri)
1045{
1046 u8 fib_notify_on_flag_change;
1047 struct fib_alias *fa_match;
1048 struct sk_buff *skb;
1049 int err;
1050
1051 rcu_read_lock();
1052
1053 fa_match = fib_find_matching_alias(net, fri);
1054 if (!fa_match)
1055 goto out;
1056
1057 /* These are paired with the WRITE_ONCE() happening in this function.
1058 * The reason is that we are only protected by RCU at this point.
1059 */
1060 if (READ_ONCE(fa_match->offload) == fri->offload &&
1061 READ_ONCE(fa_match->trap) == fri->trap &&
1062 READ_ONCE(fa_match->offload_failed) == fri->offload_failed)
1063 goto out;
1064
1065 WRITE_ONCE(fa_match->offload, fri->offload);
1066 WRITE_ONCE(fa_match->trap, fri->trap);
1067
1068 fib_notify_on_flag_change = READ_ONCE(net->ipv4.sysctl_fib_notify_on_flag_change);
1069
1070 /* 2 means send notifications only if offload_failed was changed. */
1071 if (fib_notify_on_flag_change == 2 &&
1072 READ_ONCE(fa_match->offload_failed) == fri->offload_failed)
1073 goto out;
1074
1075 WRITE_ONCE(fa_match->offload_failed, fri->offload_failed);
1076
1077 if (!fib_notify_on_flag_change)
1078 goto out;
1079
1080 skb = nlmsg_new(fib_nlmsg_size(fa_match->fa_info), GFP_ATOMIC);
1081 if (!skb) {
1082 err = -ENOBUFS;
1083 goto errout;
1084 }
1085
1086 err = fib_dump_info(skb, 0, 0, RTM_NEWROUTE, fri, 0);
1087 if (err < 0) {
1088 /* -EMSGSIZE implies BUG in fib_nlmsg_size() */
1089 WARN_ON(err == -EMSGSIZE);
1090 kfree_skb(skb);
1091 goto errout;
1092 }
1093
1094 rtnl_notify(skb, net, 0, RTNLGRP_IPV4_ROUTE, NULL, GFP_ATOMIC);
1095 goto out;
1096
1097errout:
1098 rtnl_set_sk_err(net, RTNLGRP_IPV4_ROUTE, err);
1099out:
1100 rcu_read_unlock();
1101}
1102EXPORT_SYMBOL_GPL(fib_alias_hw_flags_set);
1103
1104static void trie_rebalance(struct trie *t, struct key_vector *tn)
1105{
1106 while (!IS_TRIE(tn))
1107 tn = resize(t, tn);
1108}
1109
1110static int fib_insert_node(struct trie *t, struct key_vector *tp,
1111 struct fib_alias *new, t_key key)
1112{
1113 struct key_vector *n, *l;
1114
1115 l = leaf_new(key, new);
1116 if (!l)
1117 goto noleaf;
1118
1119 /* retrieve child from parent node */
1120 n = get_child(tp, get_index(key, tp));
1121
1122 /* Case 2: n is a LEAF or a TNODE and the key doesn't match.
1123 *
1124 * Add a new tnode here
1125 * first tnode need some special handling
1126 * leaves us in position for handling as case 3
1127 */
1128 if (n) {
1129 struct key_vector *tn;
1130
1131 tn = tnode_new(key, __fls(key ^ n->key), 1);
1132 if (!tn)
1133 goto notnode;
1134
1135 /* initialize routes out of node */
1136 NODE_INIT_PARENT(tn, tp);
1137 put_child(tn, get_index(key, tn) ^ 1, n);
1138
1139 /* start adding routes into the node */
1140 put_child_root(tp, key, tn);
1141 node_set_parent(n, tn);
1142
1143 /* parent now has a NULL spot where the leaf can go */
1144 tp = tn;
1145 }
1146
1147 /* Case 3: n is NULL, and will just insert a new leaf */
1148 node_push_suffix(tp, new->fa_slen);
1149 NODE_INIT_PARENT(l, tp);
1150 put_child_root(tp, key, l);
1151 trie_rebalance(t, tp);
1152
1153 return 0;
1154notnode:
1155 node_free(l);
1156noleaf:
1157 return -ENOMEM;
1158}
1159
1160static int fib_insert_alias(struct trie *t, struct key_vector *tp,
1161 struct key_vector *l, struct fib_alias *new,
1162 struct fib_alias *fa, t_key key)
1163{
1164 if (!l)
1165 return fib_insert_node(t, tp, new, key);
1166
1167 if (fa) {
1168 hlist_add_before_rcu(&new->fa_list, &fa->fa_list);
1169 } else {
1170 struct fib_alias *last;
1171
1172 hlist_for_each_entry(last, &l->leaf, fa_list) {
1173 if (new->fa_slen < last->fa_slen)
1174 break;
1175 if ((new->fa_slen == last->fa_slen) &&
1176 (new->tb_id > last->tb_id))
1177 break;
1178 fa = last;
1179 }
1180
1181 if (fa)
1182 hlist_add_behind_rcu(&new->fa_list, &fa->fa_list);
1183 else
1184 hlist_add_head_rcu(&new->fa_list, &l->leaf);
1185 }
1186
1187 /* if we added to the tail node then we need to update slen */
1188 if (l->slen < new->fa_slen) {
1189 l->slen = new->fa_slen;
1190 node_push_suffix(tp, new->fa_slen);
1191 }
1192
1193 return 0;
1194}
1195
1196static bool fib_valid_key_len(u32 key, u8 plen, struct netlink_ext_ack *extack)
1197{
1198 if (plen > KEYLENGTH) {
1199 NL_SET_ERR_MSG(extack, "Invalid prefix length");
1200 return false;
1201 }
1202
1203 if ((plen < KEYLENGTH) && (key << plen)) {
1204 NL_SET_ERR_MSG(extack,
1205 "Invalid prefix for given prefix length");
1206 return false;
1207 }
1208
1209 return true;
1210}
1211
1212static void fib_remove_alias(struct trie *t, struct key_vector *tp,
1213 struct key_vector *l, struct fib_alias *old);
1214
1215/* Caller must hold RTNL. */
1216int fib_table_insert(struct net *net, struct fib_table *tb,
1217 struct fib_config *cfg, struct netlink_ext_ack *extack)
1218{
1219 struct trie *t = (struct trie *)tb->tb_data;
1220 struct fib_alias *fa, *new_fa;
1221 struct key_vector *l, *tp;
1222 u16 nlflags = NLM_F_EXCL;
1223 struct fib_info *fi;
1224 u8 plen = cfg->fc_dst_len;
1225 u8 slen = KEYLENGTH - plen;
1226 dscp_t dscp;
1227 u32 key;
1228 int err;
1229
1230 key = ntohl(cfg->fc_dst);
1231
1232 if (!fib_valid_key_len(key, plen, extack))
1233 return -EINVAL;
1234
1235 pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
1236
1237 fi = fib_create_info(cfg, extack);
1238 if (IS_ERR(fi)) {
1239 err = PTR_ERR(fi);
1240 goto err;
1241 }
1242
1243 dscp = cfg->fc_dscp;
1244 l = fib_find_node(t, &tp, key);
1245 fa = l ? fib_find_alias(&l->leaf, slen, dscp, fi->fib_priority,
1246 tb->tb_id, false) : NULL;
1247
1248 /* Now fa, if non-NULL, points to the first fib alias
1249 * with the same keys [prefix,dscp,priority], if such key already
1250 * exists or to the node before which we will insert new one.
1251 *
1252 * If fa is NULL, we will need to allocate a new one and
1253 * insert to the tail of the section matching the suffix length
1254 * of the new alias.
1255 */
1256
1257 if (fa && fa->fa_dscp == dscp &&
1258 fa->fa_info->fib_priority == fi->fib_priority) {
1259 struct fib_alias *fa_first, *fa_match;
1260
1261 err = -EEXIST;
1262 if (cfg->fc_nlflags & NLM_F_EXCL)
1263 goto out;
1264
1265 nlflags &= ~NLM_F_EXCL;
1266
1267 /* We have 2 goals:
1268 * 1. Find exact match for type, scope, fib_info to avoid
1269 * duplicate routes
1270 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
1271 */
1272 fa_match = NULL;
1273 fa_first = fa;
1274 hlist_for_each_entry_from(fa, fa_list) {
1275 if ((fa->fa_slen != slen) ||
1276 (fa->tb_id != tb->tb_id) ||
1277 (fa->fa_dscp != dscp))
1278 break;
1279 if (fa->fa_info->fib_priority != fi->fib_priority)
1280 break;
1281 if (fa->fa_type == cfg->fc_type &&
1282 fa->fa_info == fi) {
1283 fa_match = fa;
1284 break;
1285 }
1286 }
1287
1288 if (cfg->fc_nlflags & NLM_F_REPLACE) {
1289 struct fib_info *fi_drop;
1290 u8 state;
1291
1292 nlflags |= NLM_F_REPLACE;
1293 fa = fa_first;
1294 if (fa_match) {
1295 if (fa == fa_match)
1296 err = 0;
1297 goto out;
1298 }
1299 err = -ENOBUFS;
1300 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1301 if (!new_fa)
1302 goto out;
1303
1304 fi_drop = fa->fa_info;
1305 new_fa->fa_dscp = fa->fa_dscp;
1306 new_fa->fa_info = fi;
1307 new_fa->fa_type = cfg->fc_type;
1308 state = fa->fa_state;
1309 new_fa->fa_state = state & ~FA_S_ACCESSED;
1310 new_fa->fa_slen = fa->fa_slen;
1311 new_fa->tb_id = tb->tb_id;
1312 new_fa->fa_default = -1;
1313 new_fa->offload = 0;
1314 new_fa->trap = 0;
1315 new_fa->offload_failed = 0;
1316
1317 hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list);
1318
1319 if (fib_find_alias(&l->leaf, fa->fa_slen, 0, 0,
1320 tb->tb_id, true) == new_fa) {
1321 enum fib_event_type fib_event;
1322
1323 fib_event = FIB_EVENT_ENTRY_REPLACE;
1324 err = call_fib_entry_notifiers(net, fib_event,
1325 key, plen,
1326 new_fa, extack);
1327 if (err) {
1328 hlist_replace_rcu(&new_fa->fa_list,
1329 &fa->fa_list);
1330 goto out_free_new_fa;
1331 }
1332 }
1333
1334 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
1335 tb->tb_id, &cfg->fc_nlinfo, nlflags);
1336
1337 alias_free_mem_rcu(fa);
1338
1339 fib_release_info(fi_drop);
1340 if (state & FA_S_ACCESSED)
1341 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1342
1343 goto succeeded;
1344 }
1345 /* Error if we find a perfect match which
1346 * uses the same scope, type, and nexthop
1347 * information.
1348 */
1349 if (fa_match)
1350 goto out;
1351
1352 if (cfg->fc_nlflags & NLM_F_APPEND)
1353 nlflags |= NLM_F_APPEND;
1354 else
1355 fa = fa_first;
1356 }
1357 err = -ENOENT;
1358 if (!(cfg->fc_nlflags & NLM_F_CREATE))
1359 goto out;
1360
1361 nlflags |= NLM_F_CREATE;
1362 err = -ENOBUFS;
1363 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1364 if (!new_fa)
1365 goto out;
1366
1367 new_fa->fa_info = fi;
1368 new_fa->fa_dscp = dscp;
1369 new_fa->fa_type = cfg->fc_type;
1370 new_fa->fa_state = 0;
1371 new_fa->fa_slen = slen;
1372 new_fa->tb_id = tb->tb_id;
1373 new_fa->fa_default = -1;
1374 new_fa->offload = 0;
1375 new_fa->trap = 0;
1376 new_fa->offload_failed = 0;
1377
1378 /* Insert new entry to the list. */
1379 err = fib_insert_alias(t, tp, l, new_fa, fa, key);
1380 if (err)
1381 goto out_free_new_fa;
1382
1383 /* The alias was already inserted, so the node must exist. */
1384 l = l ? l : fib_find_node(t, &tp, key);
1385 if (WARN_ON_ONCE(!l)) {
1386 err = -ENOENT;
1387 goto out_free_new_fa;
1388 }
1389
1390 if (fib_find_alias(&l->leaf, new_fa->fa_slen, 0, 0, tb->tb_id, true) ==
1391 new_fa) {
1392 enum fib_event_type fib_event;
1393
1394 fib_event = FIB_EVENT_ENTRY_REPLACE;
1395 err = call_fib_entry_notifiers(net, fib_event, key, plen,
1396 new_fa, extack);
1397 if (err)
1398 goto out_remove_new_fa;
1399 }
1400
1401 if (!plen)
1402 tb->tb_num_default++;
1403
1404 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1405 rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id,
1406 &cfg->fc_nlinfo, nlflags);
1407succeeded:
1408 return 0;
1409
1410out_remove_new_fa:
1411 fib_remove_alias(t, tp, l, new_fa);
1412out_free_new_fa:
1413 kmem_cache_free(fn_alias_kmem, new_fa);
1414out:
1415 fib_release_info(fi);
1416err:
1417 return err;
1418}
1419
1420static inline t_key prefix_mismatch(t_key key, struct key_vector *n)
1421{
1422 t_key prefix = n->key;
1423
1424 return (key ^ prefix) & (prefix | -prefix);
1425}
1426
1427bool fib_lookup_good_nhc(const struct fib_nh_common *nhc, int fib_flags,
1428 const struct flowi4 *flp)
1429{
1430 if (nhc->nhc_flags & RTNH_F_DEAD)
1431 return false;
1432
1433 if (ip_ignore_linkdown(nhc->nhc_dev) &&
1434 nhc->nhc_flags & RTNH_F_LINKDOWN &&
1435 !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE))
1436 return false;
1437
1438 if (flp->flowi4_oif && flp->flowi4_oif != nhc->nhc_oif)
1439 return false;
1440
1441 return true;
1442}
1443
1444/* should be called with rcu_read_lock */
1445int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
1446 struct fib_result *res, int fib_flags)
1447{
1448 struct trie *t = (struct trie *) tb->tb_data;
1449#ifdef CONFIG_IP_FIB_TRIE_STATS
1450 struct trie_use_stats __percpu *stats = t->stats;
1451#endif
1452 const t_key key = ntohl(flp->daddr);
1453 struct key_vector *n, *pn;
1454 struct fib_alias *fa;
1455 unsigned long index;
1456 t_key cindex;
1457
1458 pn = t->kv;
1459 cindex = 0;
1460
1461 n = get_child_rcu(pn, cindex);
1462 if (!n) {
1463 trace_fib_table_lookup(tb->tb_id, flp, NULL, -EAGAIN);
1464 return -EAGAIN;
1465 }
1466
1467#ifdef CONFIG_IP_FIB_TRIE_STATS
1468 this_cpu_inc(stats->gets);
1469#endif
1470
1471 /* Step 1: Travel to the longest prefix match in the trie */
1472 for (;;) {
1473 index = get_cindex(key, n);
1474
1475 /* This bit of code is a bit tricky but it combines multiple
1476 * checks into a single check. The prefix consists of the
1477 * prefix plus zeros for the "bits" in the prefix. The index
1478 * is the difference between the key and this value. From
1479 * this we can actually derive several pieces of data.
1480 * if (index >= (1ul << bits))
1481 * we have a mismatch in skip bits and failed
1482 * else
1483 * we know the value is cindex
1484 *
1485 * This check is safe even if bits == KEYLENGTH due to the
1486 * fact that we can only allocate a node with 32 bits if a
1487 * long is greater than 32 bits.
1488 */
1489 if (index >= (1ul << n->bits))
1490 break;
1491
1492 /* we have found a leaf. Prefixes have already been compared */
1493 if (IS_LEAF(n))
1494 goto found;
1495
1496 /* only record pn and cindex if we are going to be chopping
1497 * bits later. Otherwise we are just wasting cycles.
1498 */
1499 if (n->slen > n->pos) {
1500 pn = n;
1501 cindex = index;
1502 }
1503
1504 n = get_child_rcu(n, index);
1505 if (unlikely(!n))
1506 goto backtrace;
1507 }
1508
1509 /* Step 2: Sort out leaves and begin backtracing for longest prefix */
1510 for (;;) {
1511 /* record the pointer where our next node pointer is stored */
1512 struct key_vector __rcu **cptr = n->tnode;
1513
1514 /* This test verifies that none of the bits that differ
1515 * between the key and the prefix exist in the region of
1516 * the lsb and higher in the prefix.
1517 */
1518 if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos))
1519 goto backtrace;
1520
1521 /* exit out and process leaf */
1522 if (unlikely(IS_LEAF(n)))
1523 break;
1524
1525 /* Don't bother recording parent info. Since we are in
1526 * prefix match mode we will have to come back to wherever
1527 * we started this traversal anyway
1528 */
1529
1530 while ((n = rcu_dereference(*cptr)) == NULL) {
1531backtrace:
1532#ifdef CONFIG_IP_FIB_TRIE_STATS
1533 if (!n)
1534 this_cpu_inc(stats->null_node_hit);
1535#endif
1536 /* If we are at cindex 0 there are no more bits for
1537 * us to strip at this level so we must ascend back
1538 * up one level to see if there are any more bits to
1539 * be stripped there.
1540 */
1541 while (!cindex) {
1542 t_key pkey = pn->key;
1543
1544 /* If we don't have a parent then there is
1545 * nothing for us to do as we do not have any
1546 * further nodes to parse.
1547 */
1548 if (IS_TRIE(pn)) {
1549 trace_fib_table_lookup(tb->tb_id, flp,
1550 NULL, -EAGAIN);
1551 return -EAGAIN;
1552 }
1553#ifdef CONFIG_IP_FIB_TRIE_STATS
1554 this_cpu_inc(stats->backtrack);
1555#endif
1556 /* Get Child's index */
1557 pn = node_parent_rcu(pn);
1558 cindex = get_index(pkey, pn);
1559 }
1560
1561 /* strip the least significant bit from the cindex */
1562 cindex &= cindex - 1;
1563
1564 /* grab pointer for next child node */
1565 cptr = &pn->tnode[cindex];
1566 }
1567 }
1568
1569found:
1570 /* this line carries forward the xor from earlier in the function */
1571 index = key ^ n->key;
1572
1573 /* Step 3: Process the leaf, if that fails fall back to backtracing */
1574 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
1575 struct fib_info *fi = fa->fa_info;
1576 struct fib_nh_common *nhc;
1577 int nhsel, err;
1578
1579 if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) {
1580 if (index >= (1ul << fa->fa_slen))
1581 continue;
1582 }
1583 if (fa->fa_dscp &&
1584 inet_dscp_to_dsfield(fa->fa_dscp) != flp->flowi4_tos)
1585 continue;
1586 /* Paired with WRITE_ONCE() in fib_release_info() */
1587 if (READ_ONCE(fi->fib_dead))
1588 continue;
1589 if (fa->fa_info->fib_scope < flp->flowi4_scope)
1590 continue;
1591 fib_alias_accessed(fa);
1592 err = fib_props[fa->fa_type].error;
1593 if (unlikely(err < 0)) {
1594out_reject:
1595#ifdef CONFIG_IP_FIB_TRIE_STATS
1596 this_cpu_inc(stats->semantic_match_passed);
1597#endif
1598 trace_fib_table_lookup(tb->tb_id, flp, NULL, err);
1599 return err;
1600 }
1601 if (fi->fib_flags & RTNH_F_DEAD)
1602 continue;
1603
1604 if (unlikely(fi->nh)) {
1605 if (nexthop_is_blackhole(fi->nh)) {
1606 err = fib_props[RTN_BLACKHOLE].error;
1607 goto out_reject;
1608 }
1609
1610 nhc = nexthop_get_nhc_lookup(fi->nh, fib_flags, flp,
1611 &nhsel);
1612 if (nhc)
1613 goto set_result;
1614 goto miss;
1615 }
1616
1617 for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) {
1618 nhc = fib_info_nhc(fi, nhsel);
1619
1620 if (!fib_lookup_good_nhc(nhc, fib_flags, flp))
1621 continue;
1622set_result:
1623 if (!(fib_flags & FIB_LOOKUP_NOREF))
1624 refcount_inc(&fi->fib_clntref);
1625
1626 res->prefix = htonl(n->key);
1627 res->prefixlen = KEYLENGTH - fa->fa_slen;
1628 res->nh_sel = nhsel;
1629 res->nhc = nhc;
1630 res->type = fa->fa_type;
1631 res->scope = fi->fib_scope;
1632 res->fi = fi;
1633 res->table = tb;
1634 res->fa_head = &n->leaf;
1635#ifdef CONFIG_IP_FIB_TRIE_STATS
1636 this_cpu_inc(stats->semantic_match_passed);
1637#endif
1638 trace_fib_table_lookup(tb->tb_id, flp, nhc, err);
1639
1640 return err;
1641 }
1642 }
1643miss:
1644#ifdef CONFIG_IP_FIB_TRIE_STATS
1645 this_cpu_inc(stats->semantic_match_miss);
1646#endif
1647 goto backtrace;
1648}
1649EXPORT_SYMBOL_GPL(fib_table_lookup);
1650
1651static void fib_remove_alias(struct trie *t, struct key_vector *tp,
1652 struct key_vector *l, struct fib_alias *old)
1653{
1654 /* record the location of the previous list_info entry */
1655 struct hlist_node **pprev = old->fa_list.pprev;
1656 struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next);
1657
1658 /* remove the fib_alias from the list */
1659 hlist_del_rcu(&old->fa_list);
1660
1661 /* if we emptied the list this leaf will be freed and we can sort
1662 * out parent suffix lengths as a part of trie_rebalance
1663 */
1664 if (hlist_empty(&l->leaf)) {
1665 if (tp->slen == l->slen)
1666 node_pull_suffix(tp, tp->pos);
1667 put_child_root(tp, l->key, NULL);
1668 node_free(l);
1669 trie_rebalance(t, tp);
1670 return;
1671 }
1672
1673 /* only access fa if it is pointing at the last valid hlist_node */
1674 if (*pprev)
1675 return;
1676
1677 /* update the trie with the latest suffix length */
1678 l->slen = fa->fa_slen;
1679 node_pull_suffix(tp, fa->fa_slen);
1680}
1681
1682static void fib_notify_alias_delete(struct net *net, u32 key,
1683 struct hlist_head *fah,
1684 struct fib_alias *fa_to_delete,
1685 struct netlink_ext_ack *extack)
1686{
1687 struct fib_alias *fa_next, *fa_to_notify;
1688 u32 tb_id = fa_to_delete->tb_id;
1689 u8 slen = fa_to_delete->fa_slen;
1690 enum fib_event_type fib_event;
1691
1692 /* Do not notify if we do not care about the route. */
1693 if (fib_find_alias(fah, slen, 0, 0, tb_id, true) != fa_to_delete)
1694 return;
1695
1696 /* Determine if the route should be replaced by the next route in the
1697 * list.
1698 */
1699 fa_next = hlist_entry_safe(fa_to_delete->fa_list.next,
1700 struct fib_alias, fa_list);
1701 if (fa_next && fa_next->fa_slen == slen && fa_next->tb_id == tb_id) {
1702 fib_event = FIB_EVENT_ENTRY_REPLACE;
1703 fa_to_notify = fa_next;
1704 } else {
1705 fib_event = FIB_EVENT_ENTRY_DEL;
1706 fa_to_notify = fa_to_delete;
1707 }
1708 call_fib_entry_notifiers(net, fib_event, key, KEYLENGTH - slen,
1709 fa_to_notify, extack);
1710}
1711
1712/* Caller must hold RTNL. */
1713int fib_table_delete(struct net *net, struct fib_table *tb,
1714 struct fib_config *cfg, struct netlink_ext_ack *extack)
1715{
1716 struct trie *t = (struct trie *) tb->tb_data;
1717 struct fib_alias *fa, *fa_to_delete;
1718 struct key_vector *l, *tp;
1719 u8 plen = cfg->fc_dst_len;
1720 u8 slen = KEYLENGTH - plen;
1721 dscp_t dscp;
1722 u32 key;
1723
1724 key = ntohl(cfg->fc_dst);
1725
1726 if (!fib_valid_key_len(key, plen, extack))
1727 return -EINVAL;
1728
1729 l = fib_find_node(t, &tp, key);
1730 if (!l)
1731 return -ESRCH;
1732
1733 dscp = cfg->fc_dscp;
1734 fa = fib_find_alias(&l->leaf, slen, dscp, 0, tb->tb_id, false);
1735 if (!fa)
1736 return -ESRCH;
1737
1738 pr_debug("Deleting %08x/%d dsfield=0x%02x t=%p\n", key, plen,
1739 inet_dscp_to_dsfield(dscp), t);
1740
1741 fa_to_delete = NULL;
1742 hlist_for_each_entry_from(fa, fa_list) {
1743 struct fib_info *fi = fa->fa_info;
1744
1745 if ((fa->fa_slen != slen) ||
1746 (fa->tb_id != tb->tb_id) ||
1747 (fa->fa_dscp != dscp))
1748 break;
1749
1750 if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
1751 (cfg->fc_scope == RT_SCOPE_NOWHERE ||
1752 fa->fa_info->fib_scope == cfg->fc_scope) &&
1753 (!cfg->fc_prefsrc ||
1754 fi->fib_prefsrc == cfg->fc_prefsrc) &&
1755 (!cfg->fc_protocol ||
1756 fi->fib_protocol == cfg->fc_protocol) &&
1757 fib_nh_match(net, cfg, fi, extack) == 0 &&
1758 fib_metrics_match(cfg, fi)) {
1759 fa_to_delete = fa;
1760 break;
1761 }
1762 }
1763
1764 if (!fa_to_delete)
1765 return -ESRCH;
1766
1767 fib_notify_alias_delete(net, key, &l->leaf, fa_to_delete, extack);
1768 rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id,
1769 &cfg->fc_nlinfo, 0);
1770
1771 if (!plen)
1772 tb->tb_num_default--;
1773
1774 fib_remove_alias(t, tp, l, fa_to_delete);
1775
1776 if (fa_to_delete->fa_state & FA_S_ACCESSED)
1777 rt_cache_flush(cfg->fc_nlinfo.nl_net);
1778
1779 fib_release_info(fa_to_delete->fa_info);
1780 alias_free_mem_rcu(fa_to_delete);
1781 return 0;
1782}
1783
1784/* Scan for the next leaf starting at the provided key value */
1785static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key)
1786{
1787 struct key_vector *pn, *n = *tn;
1788 unsigned long cindex;
1789
1790 /* this loop is meant to try and find the key in the trie */
1791 do {
1792 /* record parent and next child index */
1793 pn = n;
1794 cindex = (key > pn->key) ? get_index(key, pn) : 0;
1795
1796 if (cindex >> pn->bits)
1797 break;
1798
1799 /* descend into the next child */
1800 n = get_child_rcu(pn, cindex++);
1801 if (!n)
1802 break;
1803
1804 /* guarantee forward progress on the keys */
1805 if (IS_LEAF(n) && (n->key >= key))
1806 goto found;
1807 } while (IS_TNODE(n));
1808
1809 /* this loop will search for the next leaf with a greater key */
1810 while (!IS_TRIE(pn)) {
1811 /* if we exhausted the parent node we will need to climb */
1812 if (cindex >= (1ul << pn->bits)) {
1813 t_key pkey = pn->key;
1814
1815 pn = node_parent_rcu(pn);
1816 cindex = get_index(pkey, pn) + 1;
1817 continue;
1818 }
1819
1820 /* grab the next available node */
1821 n = get_child_rcu(pn, cindex++);
1822 if (!n)
1823 continue;
1824
1825 /* no need to compare keys since we bumped the index */
1826 if (IS_LEAF(n))
1827 goto found;
1828
1829 /* Rescan start scanning in new node */
1830 pn = n;
1831 cindex = 0;
1832 }
1833
1834 *tn = pn;
1835 return NULL; /* Root of trie */
1836found:
1837 /* if we are at the limit for keys just return NULL for the tnode */
1838 *tn = pn;
1839 return n;
1840}
1841
1842static void fib_trie_free(struct fib_table *tb)
1843{
1844 struct trie *t = (struct trie *)tb->tb_data;
1845 struct key_vector *pn = t->kv;
1846 unsigned long cindex = 1;
1847 struct hlist_node *tmp;
1848 struct fib_alias *fa;
1849
1850 /* walk trie in reverse order and free everything */
1851 for (;;) {
1852 struct key_vector *n;
1853
1854 if (!(cindex--)) {
1855 t_key pkey = pn->key;
1856
1857 if (IS_TRIE(pn))
1858 break;
1859
1860 n = pn;
1861 pn = node_parent(pn);
1862
1863 /* drop emptied tnode */
1864 put_child_root(pn, n->key, NULL);
1865 node_free(n);
1866
1867 cindex = get_index(pkey, pn);
1868
1869 continue;
1870 }
1871
1872 /* grab the next available node */
1873 n = get_child(pn, cindex);
1874 if (!n)
1875 continue;
1876
1877 if (IS_TNODE(n)) {
1878 /* record pn and cindex for leaf walking */
1879 pn = n;
1880 cindex = 1ul << n->bits;
1881
1882 continue;
1883 }
1884
1885 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1886 hlist_del_rcu(&fa->fa_list);
1887 alias_free_mem_rcu(fa);
1888 }
1889
1890 put_child_root(pn, n->key, NULL);
1891 node_free(n);
1892 }
1893
1894#ifdef CONFIG_IP_FIB_TRIE_STATS
1895 free_percpu(t->stats);
1896#endif
1897 kfree(tb);
1898}
1899
1900struct fib_table *fib_trie_unmerge(struct fib_table *oldtb)
1901{
1902 struct trie *ot = (struct trie *)oldtb->tb_data;
1903 struct key_vector *l, *tp = ot->kv;
1904 struct fib_table *local_tb;
1905 struct fib_alias *fa;
1906 struct trie *lt;
1907 t_key key = 0;
1908
1909 if (oldtb->tb_data == oldtb->__data)
1910 return oldtb;
1911
1912 local_tb = fib_trie_table(RT_TABLE_LOCAL, NULL);
1913 if (!local_tb)
1914 return NULL;
1915
1916 lt = (struct trie *)local_tb->tb_data;
1917
1918 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
1919 struct key_vector *local_l = NULL, *local_tp;
1920
1921 hlist_for_each_entry(fa, &l->leaf, fa_list) {
1922 struct fib_alias *new_fa;
1923
1924 if (local_tb->tb_id != fa->tb_id)
1925 continue;
1926
1927 /* clone fa for new local table */
1928 new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
1929 if (!new_fa)
1930 goto out;
1931
1932 memcpy(new_fa, fa, sizeof(*fa));
1933
1934 /* insert clone into table */
1935 if (!local_l)
1936 local_l = fib_find_node(lt, &local_tp, l->key);
1937
1938 if (fib_insert_alias(lt, local_tp, local_l, new_fa,
1939 NULL, l->key)) {
1940 kmem_cache_free(fn_alias_kmem, new_fa);
1941 goto out;
1942 }
1943 }
1944
1945 /* stop loop if key wrapped back to 0 */
1946 key = l->key + 1;
1947 if (key < l->key)
1948 break;
1949 }
1950
1951 return local_tb;
1952out:
1953 fib_trie_free(local_tb);
1954
1955 return NULL;
1956}
1957
1958/* Caller must hold RTNL */
1959void fib_table_flush_external(struct fib_table *tb)
1960{
1961 struct trie *t = (struct trie *)tb->tb_data;
1962 struct key_vector *pn = t->kv;
1963 unsigned long cindex = 1;
1964 struct hlist_node *tmp;
1965 struct fib_alias *fa;
1966
1967 /* walk trie in reverse order */
1968 for (;;) {
1969 unsigned char slen = 0;
1970 struct key_vector *n;
1971
1972 if (!(cindex--)) {
1973 t_key pkey = pn->key;
1974
1975 /* cannot resize the trie vector */
1976 if (IS_TRIE(pn))
1977 break;
1978
1979 /* update the suffix to address pulled leaves */
1980 if (pn->slen > pn->pos)
1981 update_suffix(pn);
1982
1983 /* resize completed node */
1984 pn = resize(t, pn);
1985 cindex = get_index(pkey, pn);
1986
1987 continue;
1988 }
1989
1990 /* grab the next available node */
1991 n = get_child(pn, cindex);
1992 if (!n)
1993 continue;
1994
1995 if (IS_TNODE(n)) {
1996 /* record pn and cindex for leaf walking */
1997 pn = n;
1998 cindex = 1ul << n->bits;
1999
2000 continue;
2001 }
2002
2003 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
2004 /* if alias was cloned to local then we just
2005 * need to remove the local copy from main
2006 */
2007 if (tb->tb_id != fa->tb_id) {
2008 hlist_del_rcu(&fa->fa_list);
2009 alias_free_mem_rcu(fa);
2010 continue;
2011 }
2012
2013 /* record local slen */
2014 slen = fa->fa_slen;
2015 }
2016
2017 /* update leaf slen */
2018 n->slen = slen;
2019
2020 if (hlist_empty(&n->leaf)) {
2021 put_child_root(pn, n->key, NULL);
2022 node_free(n);
2023 }
2024 }
2025}
2026
2027/* Caller must hold RTNL. */
2028int fib_table_flush(struct net *net, struct fib_table *tb, bool flush_all)
2029{
2030 struct trie *t = (struct trie *)tb->tb_data;
2031 struct nl_info info = { .nl_net = net };
2032 struct key_vector *pn = t->kv;
2033 unsigned long cindex = 1;
2034 struct hlist_node *tmp;
2035 struct fib_alias *fa;
2036 int found = 0;
2037
2038 /* walk trie in reverse order */
2039 for (;;) {
2040 unsigned char slen = 0;
2041 struct key_vector *n;
2042
2043 if (!(cindex--)) {
2044 t_key pkey = pn->key;
2045
2046 /* cannot resize the trie vector */
2047 if (IS_TRIE(pn))
2048 break;
2049
2050 /* update the suffix to address pulled leaves */
2051 if (pn->slen > pn->pos)
2052 update_suffix(pn);
2053
2054 /* resize completed node */
2055 pn = resize(t, pn);
2056 cindex = get_index(pkey, pn);
2057
2058 continue;
2059 }
2060
2061 /* grab the next available node */
2062 n = get_child(pn, cindex);
2063 if (!n)
2064 continue;
2065
2066 if (IS_TNODE(n)) {
2067 /* record pn and cindex for leaf walking */
2068 pn = n;
2069 cindex = 1ul << n->bits;
2070
2071 continue;
2072 }
2073
2074 hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
2075 struct fib_info *fi = fa->fa_info;
2076
2077 if (!fi || tb->tb_id != fa->tb_id ||
2078 (!(fi->fib_flags & RTNH_F_DEAD) &&
2079 !fib_props[fa->fa_type].error)) {
2080 slen = fa->fa_slen;
2081 continue;
2082 }
2083
2084 /* Do not flush error routes if network namespace is
2085 * not being dismantled
2086 */
2087 if (!flush_all && fib_props[fa->fa_type].error) {
2088 slen = fa->fa_slen;
2089 continue;
2090 }
2091
2092 fib_notify_alias_delete(net, n->key, &n->leaf, fa,
2093 NULL);
2094 if (fi->pfsrc_removed)
2095 rtmsg_fib(RTM_DELROUTE, htonl(n->key), fa,
2096 KEYLENGTH - fa->fa_slen, tb->tb_id, &info, 0);
2097 hlist_del_rcu(&fa->fa_list);
2098 fib_release_info(fa->fa_info);
2099 alias_free_mem_rcu(fa);
2100 found++;
2101 }
2102
2103 /* update leaf slen */
2104 n->slen = slen;
2105
2106 if (hlist_empty(&n->leaf)) {
2107 put_child_root(pn, n->key, NULL);
2108 node_free(n);
2109 }
2110 }
2111
2112 pr_debug("trie_flush found=%d\n", found);
2113 return found;
2114}
2115
2116/* derived from fib_trie_free */
2117static void __fib_info_notify_update(struct net *net, struct fib_table *tb,
2118 struct nl_info *info)
2119{
2120 struct trie *t = (struct trie *)tb->tb_data;
2121 struct key_vector *pn = t->kv;
2122 unsigned long cindex = 1;
2123 struct fib_alias *fa;
2124
2125 for (;;) {
2126 struct key_vector *n;
2127
2128 if (!(cindex--)) {
2129 t_key pkey = pn->key;
2130
2131 if (IS_TRIE(pn))
2132 break;
2133
2134 pn = node_parent(pn);
2135 cindex = get_index(pkey, pn);
2136 continue;
2137 }
2138
2139 /* grab the next available node */
2140 n = get_child(pn, cindex);
2141 if (!n)
2142 continue;
2143
2144 if (IS_TNODE(n)) {
2145 /* record pn and cindex for leaf walking */
2146 pn = n;
2147 cindex = 1ul << n->bits;
2148
2149 continue;
2150 }
2151
2152 hlist_for_each_entry(fa, &n->leaf, fa_list) {
2153 struct fib_info *fi = fa->fa_info;
2154
2155 if (!fi || !fi->nh_updated || fa->tb_id != tb->tb_id)
2156 continue;
2157
2158 rtmsg_fib(RTM_NEWROUTE, htonl(n->key), fa,
2159 KEYLENGTH - fa->fa_slen, tb->tb_id,
2160 info, NLM_F_REPLACE);
2161 }
2162 }
2163}
2164
2165void fib_info_notify_update(struct net *net, struct nl_info *info)
2166{
2167 unsigned int h;
2168
2169 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2170 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2171 struct fib_table *tb;
2172
2173 hlist_for_each_entry_rcu(tb, head, tb_hlist,
2174 lockdep_rtnl_is_held())
2175 __fib_info_notify_update(net, tb, info);
2176 }
2177}
2178
2179static int fib_leaf_notify(struct key_vector *l, struct fib_table *tb,
2180 struct notifier_block *nb,
2181 struct netlink_ext_ack *extack)
2182{
2183 struct fib_alias *fa;
2184 int last_slen = -1;
2185 int err;
2186
2187 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2188 struct fib_info *fi = fa->fa_info;
2189
2190 if (!fi)
2191 continue;
2192
2193 /* local and main table can share the same trie,
2194 * so don't notify twice for the same entry.
2195 */
2196 if (tb->tb_id != fa->tb_id)
2197 continue;
2198
2199 if (fa->fa_slen == last_slen)
2200 continue;
2201
2202 last_slen = fa->fa_slen;
2203 err = call_fib_entry_notifier(nb, FIB_EVENT_ENTRY_REPLACE,
2204 l->key, KEYLENGTH - fa->fa_slen,
2205 fa, extack);
2206 if (err)
2207 return err;
2208 }
2209 return 0;
2210}
2211
2212static int fib_table_notify(struct fib_table *tb, struct notifier_block *nb,
2213 struct netlink_ext_ack *extack)
2214{
2215 struct trie *t = (struct trie *)tb->tb_data;
2216 struct key_vector *l, *tp = t->kv;
2217 t_key key = 0;
2218 int err;
2219
2220 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
2221 err = fib_leaf_notify(l, tb, nb, extack);
2222 if (err)
2223 return err;
2224
2225 key = l->key + 1;
2226 /* stop in case of wrap around */
2227 if (key < l->key)
2228 break;
2229 }
2230 return 0;
2231}
2232
2233int fib_notify(struct net *net, struct notifier_block *nb,
2234 struct netlink_ext_ack *extack)
2235{
2236 unsigned int h;
2237 int err;
2238
2239 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2240 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2241 struct fib_table *tb;
2242
2243 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2244 err = fib_table_notify(tb, nb, extack);
2245 if (err)
2246 return err;
2247 }
2248 }
2249 return 0;
2250}
2251
2252static void __trie_free_rcu(struct rcu_head *head)
2253{
2254 struct fib_table *tb = container_of(head, struct fib_table, rcu);
2255#ifdef CONFIG_IP_FIB_TRIE_STATS
2256 struct trie *t = (struct trie *)tb->tb_data;
2257
2258 if (tb->tb_data == tb->__data)
2259 free_percpu(t->stats);
2260#endif /* CONFIG_IP_FIB_TRIE_STATS */
2261 kfree(tb);
2262}
2263
2264void fib_free_table(struct fib_table *tb)
2265{
2266 call_rcu(&tb->rcu, __trie_free_rcu);
2267}
2268
2269static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb,
2270 struct sk_buff *skb, struct netlink_callback *cb,
2271 struct fib_dump_filter *filter)
2272{
2273 unsigned int flags = NLM_F_MULTI;
2274 __be32 xkey = htonl(l->key);
2275 int i, s_i, i_fa, s_fa, err;
2276 struct fib_alias *fa;
2277
2278 if (filter->filter_set ||
2279 !filter->dump_exceptions || !filter->dump_routes)
2280 flags |= NLM_F_DUMP_FILTERED;
2281
2282 s_i = cb->args[4];
2283 s_fa = cb->args[5];
2284 i = 0;
2285
2286 /* rcu_read_lock is hold by caller */
2287 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2288 struct fib_info *fi = fa->fa_info;
2289
2290 if (i < s_i)
2291 goto next;
2292
2293 i_fa = 0;
2294
2295 if (tb->tb_id != fa->tb_id)
2296 goto next;
2297
2298 if (filter->filter_set) {
2299 if (filter->rt_type && fa->fa_type != filter->rt_type)
2300 goto next;
2301
2302 if ((filter->protocol &&
2303 fi->fib_protocol != filter->protocol))
2304 goto next;
2305
2306 if (filter->dev &&
2307 !fib_info_nh_uses_dev(fi, filter->dev))
2308 goto next;
2309 }
2310
2311 if (filter->dump_routes) {
2312 if (!s_fa) {
2313 struct fib_rt_info fri;
2314
2315 fri.fi = fi;
2316 fri.tb_id = tb->tb_id;
2317 fri.dst = xkey;
2318 fri.dst_len = KEYLENGTH - fa->fa_slen;
2319 fri.dscp = fa->fa_dscp;
2320 fri.type = fa->fa_type;
2321 fri.offload = READ_ONCE(fa->offload);
2322 fri.trap = READ_ONCE(fa->trap);
2323 fri.offload_failed = READ_ONCE(fa->offload_failed);
2324 err = fib_dump_info(skb,
2325 NETLINK_CB(cb->skb).portid,
2326 cb->nlh->nlmsg_seq,
2327 RTM_NEWROUTE, &fri, flags);
2328 if (err < 0)
2329 goto stop;
2330 }
2331
2332 i_fa++;
2333 }
2334
2335 if (filter->dump_exceptions) {
2336 err = fib_dump_info_fnhe(skb, cb, tb->tb_id, fi,
2337 &i_fa, s_fa, flags);
2338 if (err < 0)
2339 goto stop;
2340 }
2341
2342next:
2343 i++;
2344 }
2345
2346 cb->args[4] = i;
2347 return skb->len;
2348
2349stop:
2350 cb->args[4] = i;
2351 cb->args[5] = i_fa;
2352 return err;
2353}
2354
2355/* rcu_read_lock needs to be hold by caller from readside */
2356int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
2357 struct netlink_callback *cb, struct fib_dump_filter *filter)
2358{
2359 struct trie *t = (struct trie *)tb->tb_data;
2360 struct key_vector *l, *tp = t->kv;
2361 /* Dump starting at last key.
2362 * Note: 0.0.0.0/0 (ie default) is first key.
2363 */
2364 int count = cb->args[2];
2365 t_key key = cb->args[3];
2366
2367 /* First time here, count and key are both always 0. Count > 0
2368 * and key == 0 means the dump has wrapped around and we are done.
2369 */
2370 if (count && !key)
2371 return skb->len;
2372
2373 while ((l = leaf_walk_rcu(&tp, key)) != NULL) {
2374 int err;
2375
2376 err = fn_trie_dump_leaf(l, tb, skb, cb, filter);
2377 if (err < 0) {
2378 cb->args[3] = key;
2379 cb->args[2] = count;
2380 return err;
2381 }
2382
2383 ++count;
2384 key = l->key + 1;
2385
2386 memset(&cb->args[4], 0,
2387 sizeof(cb->args) - 4*sizeof(cb->args[0]));
2388
2389 /* stop loop if key wrapped back to 0 */
2390 if (key < l->key)
2391 break;
2392 }
2393
2394 cb->args[3] = key;
2395 cb->args[2] = count;
2396
2397 return skb->len;
2398}
2399
2400void __init fib_trie_init(void)
2401{
2402 fn_alias_kmem = kmem_cache_create("ip_fib_alias",
2403 sizeof(struct fib_alias),
2404 0, SLAB_PANIC | SLAB_ACCOUNT, NULL);
2405
2406 trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
2407 LEAF_SIZE,
2408 0, SLAB_PANIC | SLAB_ACCOUNT, NULL);
2409}
2410
2411struct fib_table *fib_trie_table(u32 id, struct fib_table *alias)
2412{
2413 struct fib_table *tb;
2414 struct trie *t;
2415 size_t sz = sizeof(*tb);
2416
2417 if (!alias)
2418 sz += sizeof(struct trie);
2419
2420 tb = kzalloc(sz, GFP_KERNEL);
2421 if (!tb)
2422 return NULL;
2423
2424 tb->tb_id = id;
2425 tb->tb_num_default = 0;
2426 tb->tb_data = (alias ? alias->__data : tb->__data);
2427
2428 if (alias)
2429 return tb;
2430
2431 t = (struct trie *) tb->tb_data;
2432 t->kv[0].pos = KEYLENGTH;
2433 t->kv[0].slen = KEYLENGTH;
2434#ifdef CONFIG_IP_FIB_TRIE_STATS
2435 t->stats = alloc_percpu(struct trie_use_stats);
2436 if (!t->stats) {
2437 kfree(tb);
2438 tb = NULL;
2439 }
2440#endif
2441
2442 return tb;
2443}
2444
2445#ifdef CONFIG_PROC_FS
2446/* Depth first Trie walk iterator */
2447struct fib_trie_iter {
2448 struct seq_net_private p;
2449 struct fib_table *tb;
2450 struct key_vector *tnode;
2451 unsigned int index;
2452 unsigned int depth;
2453};
2454
2455static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter)
2456{
2457 unsigned long cindex = iter->index;
2458 struct key_vector *pn = iter->tnode;
2459 t_key pkey;
2460
2461 pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
2462 iter->tnode, iter->index, iter->depth);
2463
2464 while (!IS_TRIE(pn)) {
2465 while (cindex < child_length(pn)) {
2466 struct key_vector *n = get_child_rcu(pn, cindex++);
2467
2468 if (!n)
2469 continue;
2470
2471 if (IS_LEAF(n)) {
2472 iter->tnode = pn;
2473 iter->index = cindex;
2474 } else {
2475 /* push down one level */
2476 iter->tnode = n;
2477 iter->index = 0;
2478 ++iter->depth;
2479 }
2480
2481 return n;
2482 }
2483
2484 /* Current node exhausted, pop back up */
2485 pkey = pn->key;
2486 pn = node_parent_rcu(pn);
2487 cindex = get_index(pkey, pn) + 1;
2488 --iter->depth;
2489 }
2490
2491 /* record root node so further searches know we are done */
2492 iter->tnode = pn;
2493 iter->index = 0;
2494
2495 return NULL;
2496}
2497
2498static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter,
2499 struct trie *t)
2500{
2501 struct key_vector *n, *pn;
2502
2503 if (!t)
2504 return NULL;
2505
2506 pn = t->kv;
2507 n = rcu_dereference(pn->tnode[0]);
2508 if (!n)
2509 return NULL;
2510
2511 if (IS_TNODE(n)) {
2512 iter->tnode = n;
2513 iter->index = 0;
2514 iter->depth = 1;
2515 } else {
2516 iter->tnode = pn;
2517 iter->index = 0;
2518 iter->depth = 0;
2519 }
2520
2521 return n;
2522}
2523
2524static void trie_collect_stats(struct trie *t, struct trie_stat *s)
2525{
2526 struct key_vector *n;
2527 struct fib_trie_iter iter;
2528
2529 memset(s, 0, sizeof(*s));
2530
2531 rcu_read_lock();
2532 for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) {
2533 if (IS_LEAF(n)) {
2534 struct fib_alias *fa;
2535
2536 s->leaves++;
2537 s->totdepth += iter.depth;
2538 if (iter.depth > s->maxdepth)
2539 s->maxdepth = iter.depth;
2540
2541 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list)
2542 ++s->prefixes;
2543 } else {
2544 s->tnodes++;
2545 if (n->bits < MAX_STAT_DEPTH)
2546 s->nodesizes[n->bits]++;
2547 s->nullpointers += tn_info(n)->empty_children;
2548 }
2549 }
2550 rcu_read_unlock();
2551}
2552
2553/*
2554 * This outputs /proc/net/fib_triestats
2555 */
2556static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
2557{
2558 unsigned int i, max, pointers, bytes, avdepth;
2559
2560 if (stat->leaves)
2561 avdepth = stat->totdepth*100 / stat->leaves;
2562 else
2563 avdepth = 0;
2564
2565 seq_printf(seq, "\tAver depth: %u.%02d\n",
2566 avdepth / 100, avdepth % 100);
2567 seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth);
2568
2569 seq_printf(seq, "\tLeaves: %u\n", stat->leaves);
2570 bytes = LEAF_SIZE * stat->leaves;
2571
2572 seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes);
2573 bytes += sizeof(struct fib_alias) * stat->prefixes;
2574
2575 seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);
2576 bytes += TNODE_SIZE(0) * stat->tnodes;
2577
2578 max = MAX_STAT_DEPTH;
2579 while (max > 0 && stat->nodesizes[max-1] == 0)
2580 max--;
2581
2582 pointers = 0;
2583 for (i = 1; i < max; i++)
2584 if (stat->nodesizes[i] != 0) {
2585 seq_printf(seq, " %u: %u", i, stat->nodesizes[i]);
2586 pointers += (1<<i) * stat->nodesizes[i];
2587 }
2588 seq_putc(seq, '\n');
2589 seq_printf(seq, "\tPointers: %u\n", pointers);
2590
2591 bytes += sizeof(struct key_vector *) * pointers;
2592 seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers);
2593 seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024);
2594}
2595
2596#ifdef CONFIG_IP_FIB_TRIE_STATS
2597static void trie_show_usage(struct seq_file *seq,
2598 const struct trie_use_stats __percpu *stats)
2599{
2600 struct trie_use_stats s = { 0 };
2601 int cpu;
2602
2603 /* loop through all of the CPUs and gather up the stats */
2604 for_each_possible_cpu(cpu) {
2605 const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu);
2606
2607 s.gets += pcpu->gets;
2608 s.backtrack += pcpu->backtrack;
2609 s.semantic_match_passed += pcpu->semantic_match_passed;
2610 s.semantic_match_miss += pcpu->semantic_match_miss;
2611 s.null_node_hit += pcpu->null_node_hit;
2612 s.resize_node_skipped += pcpu->resize_node_skipped;
2613 }
2614
2615 seq_printf(seq, "\nCounters:\n---------\n");
2616 seq_printf(seq, "gets = %u\n", s.gets);
2617 seq_printf(seq, "backtracks = %u\n", s.backtrack);
2618 seq_printf(seq, "semantic match passed = %u\n",
2619 s.semantic_match_passed);
2620 seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss);
2621 seq_printf(seq, "null node hit= %u\n", s.null_node_hit);
2622 seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped);
2623}
2624#endif /* CONFIG_IP_FIB_TRIE_STATS */
2625
2626static void fib_table_print(struct seq_file *seq, struct fib_table *tb)
2627{
2628 if (tb->tb_id == RT_TABLE_LOCAL)
2629 seq_puts(seq, "Local:\n");
2630 else if (tb->tb_id == RT_TABLE_MAIN)
2631 seq_puts(seq, "Main:\n");
2632 else
2633 seq_printf(seq, "Id %d:\n", tb->tb_id);
2634}
2635
2636
2637static int fib_triestat_seq_show(struct seq_file *seq, void *v)
2638{
2639 struct net *net = seq->private;
2640 unsigned int h;
2641
2642 seq_printf(seq,
2643 "Basic info: size of leaf:"
2644 " %zd bytes, size of tnode: %zd bytes.\n",
2645 LEAF_SIZE, TNODE_SIZE(0));
2646
2647 rcu_read_lock();
2648 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2649 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2650 struct fib_table *tb;
2651
2652 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2653 struct trie *t = (struct trie *) tb->tb_data;
2654 struct trie_stat stat;
2655
2656 if (!t)
2657 continue;
2658
2659 fib_table_print(seq, tb);
2660
2661 trie_collect_stats(t, &stat);
2662 trie_show_stats(seq, &stat);
2663#ifdef CONFIG_IP_FIB_TRIE_STATS
2664 trie_show_usage(seq, t->stats);
2665#endif
2666 }
2667 cond_resched_rcu();
2668 }
2669 rcu_read_unlock();
2670
2671 return 0;
2672}
2673
2674static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos)
2675{
2676 struct fib_trie_iter *iter = seq->private;
2677 struct net *net = seq_file_net(seq);
2678 loff_t idx = 0;
2679 unsigned int h;
2680
2681 for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2682 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2683 struct fib_table *tb;
2684
2685 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2686 struct key_vector *n;
2687
2688 for (n = fib_trie_get_first(iter,
2689 (struct trie *) tb->tb_data);
2690 n; n = fib_trie_get_next(iter))
2691 if (pos == idx++) {
2692 iter->tb = tb;
2693 return n;
2694 }
2695 }
2696 }
2697
2698 return NULL;
2699}
2700
2701static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
2702 __acquires(RCU)
2703{
2704 rcu_read_lock();
2705 return fib_trie_get_idx(seq, *pos);
2706}
2707
2708static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2709{
2710 struct fib_trie_iter *iter = seq->private;
2711 struct net *net = seq_file_net(seq);
2712 struct fib_table *tb = iter->tb;
2713 struct hlist_node *tb_node;
2714 unsigned int h;
2715 struct key_vector *n;
2716
2717 ++*pos;
2718 /* next node in same table */
2719 n = fib_trie_get_next(iter);
2720 if (n)
2721 return n;
2722
2723 /* walk rest of this hash chain */
2724 h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);
2725 while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) {
2726 tb = hlist_entry(tb_node, struct fib_table, tb_hlist);
2727 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2728 if (n)
2729 goto found;
2730 }
2731
2732 /* new hash chain */
2733 while (++h < FIB_TABLE_HASHSZ) {
2734 struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2735 hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2736 n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2737 if (n)
2738 goto found;
2739 }
2740 }
2741 return NULL;
2742
2743found:
2744 iter->tb = tb;
2745 return n;
2746}
2747
2748static void fib_trie_seq_stop(struct seq_file *seq, void *v)
2749 __releases(RCU)
2750{
2751 rcu_read_unlock();
2752}
2753
2754static void seq_indent(struct seq_file *seq, int n)
2755{
2756 while (n-- > 0)
2757 seq_puts(seq, " ");
2758}
2759
2760static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
2761{
2762 switch (s) {
2763 case RT_SCOPE_UNIVERSE: return "universe";
2764 case RT_SCOPE_SITE: return "site";
2765 case RT_SCOPE_LINK: return "link";
2766 case RT_SCOPE_HOST: return "host";
2767 case RT_SCOPE_NOWHERE: return "nowhere";
2768 default:
2769 snprintf(buf, len, "scope=%d", s);
2770 return buf;
2771 }
2772}
2773
2774static const char *const rtn_type_names[__RTN_MAX] = {
2775 [RTN_UNSPEC] = "UNSPEC",
2776 [RTN_UNICAST] = "UNICAST",
2777 [RTN_LOCAL] = "LOCAL",
2778 [RTN_BROADCAST] = "BROADCAST",
2779 [RTN_ANYCAST] = "ANYCAST",
2780 [RTN_MULTICAST] = "MULTICAST",
2781 [RTN_BLACKHOLE] = "BLACKHOLE",
2782 [RTN_UNREACHABLE] = "UNREACHABLE",
2783 [RTN_PROHIBIT] = "PROHIBIT",
2784 [RTN_THROW] = "THROW",
2785 [RTN_NAT] = "NAT",
2786 [RTN_XRESOLVE] = "XRESOLVE",
2787};
2788
2789static inline const char *rtn_type(char *buf, size_t len, unsigned int t)
2790{
2791 if (t < __RTN_MAX && rtn_type_names[t])
2792 return rtn_type_names[t];
2793 snprintf(buf, len, "type %u", t);
2794 return buf;
2795}
2796
2797/* Pretty print the trie */
2798static int fib_trie_seq_show(struct seq_file *seq, void *v)
2799{
2800 const struct fib_trie_iter *iter = seq->private;
2801 struct key_vector *n = v;
2802
2803 if (IS_TRIE(node_parent_rcu(n)))
2804 fib_table_print(seq, iter->tb);
2805
2806 if (IS_TNODE(n)) {
2807 __be32 prf = htonl(n->key);
2808
2809 seq_indent(seq, iter->depth-1);
2810 seq_printf(seq, " +-- %pI4/%zu %u %u %u\n",
2811 &prf, KEYLENGTH - n->pos - n->bits, n->bits,
2812 tn_info(n)->full_children,
2813 tn_info(n)->empty_children);
2814 } else {
2815 __be32 val = htonl(n->key);
2816 struct fib_alias *fa;
2817
2818 seq_indent(seq, iter->depth);
2819 seq_printf(seq, " |-- %pI4\n", &val);
2820
2821 hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
2822 char buf1[32], buf2[32];
2823
2824 seq_indent(seq, iter->depth + 1);
2825 seq_printf(seq, " /%zu %s %s",
2826 KEYLENGTH - fa->fa_slen,
2827 rtn_scope(buf1, sizeof(buf1),
2828 fa->fa_info->fib_scope),
2829 rtn_type(buf2, sizeof(buf2),
2830 fa->fa_type));
2831 if (fa->fa_dscp)
2832 seq_printf(seq, " tos=%d",
2833 inet_dscp_to_dsfield(fa->fa_dscp));
2834 seq_putc(seq, '\n');
2835 }
2836 }
2837
2838 return 0;
2839}
2840
2841static const struct seq_operations fib_trie_seq_ops = {
2842 .start = fib_trie_seq_start,
2843 .next = fib_trie_seq_next,
2844 .stop = fib_trie_seq_stop,
2845 .show = fib_trie_seq_show,
2846};
2847
2848struct fib_route_iter {
2849 struct seq_net_private p;
2850 struct fib_table *main_tb;
2851 struct key_vector *tnode;
2852 loff_t pos;
2853 t_key key;
2854};
2855
2856static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter,
2857 loff_t pos)
2858{
2859 struct key_vector *l, **tp = &iter->tnode;
2860 t_key key;
2861
2862 /* use cached location of previously found key */
2863 if (iter->pos > 0 && pos >= iter->pos) {
2864 key = iter->key;
2865 } else {
2866 iter->pos = 1;
2867 key = 0;
2868 }
2869
2870 pos -= iter->pos;
2871
2872 while ((l = leaf_walk_rcu(tp, key)) && (pos-- > 0)) {
2873 key = l->key + 1;
2874 iter->pos++;
2875 l = NULL;
2876
2877 /* handle unlikely case of a key wrap */
2878 if (!key)
2879 break;
2880 }
2881
2882 if (l)
2883 iter->key = l->key; /* remember it */
2884 else
2885 iter->pos = 0; /* forget it */
2886
2887 return l;
2888}
2889
2890static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos)
2891 __acquires(RCU)
2892{
2893 struct fib_route_iter *iter = seq->private;
2894 struct fib_table *tb;
2895 struct trie *t;
2896
2897 rcu_read_lock();
2898
2899 tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
2900 if (!tb)
2901 return NULL;
2902
2903 iter->main_tb = tb;
2904 t = (struct trie *)tb->tb_data;
2905 iter->tnode = t->kv;
2906
2907 if (*pos != 0)
2908 return fib_route_get_idx(iter, *pos);
2909
2910 iter->pos = 0;
2911 iter->key = KEY_MAX;
2912
2913 return SEQ_START_TOKEN;
2914}
2915
2916static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2917{
2918 struct fib_route_iter *iter = seq->private;
2919 struct key_vector *l = NULL;
2920 t_key key = iter->key + 1;
2921
2922 ++*pos;
2923
2924 /* only allow key of 0 for start of sequence */
2925 if ((v == SEQ_START_TOKEN) || key)
2926 l = leaf_walk_rcu(&iter->tnode, key);
2927
2928 if (l) {
2929 iter->key = l->key;
2930 iter->pos++;
2931 } else {
2932 iter->pos = 0;
2933 }
2934
2935 return l;
2936}
2937
2938static void fib_route_seq_stop(struct seq_file *seq, void *v)
2939 __releases(RCU)
2940{
2941 rcu_read_unlock();
2942}
2943
2944static unsigned int fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
2945{
2946 unsigned int flags = 0;
2947
2948 if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT)
2949 flags = RTF_REJECT;
2950 if (fi) {
2951 const struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
2952
2953 if (nhc->nhc_gw.ipv4)
2954 flags |= RTF_GATEWAY;
2955 }
2956 if (mask == htonl(0xFFFFFFFF))
2957 flags |= RTF_HOST;
2958 flags |= RTF_UP;
2959 return flags;
2960}
2961
2962/*
2963 * This outputs /proc/net/route.
2964 * The format of the file is not supposed to be changed
2965 * and needs to be same as fib_hash output to avoid breaking
2966 * legacy utilities
2967 */
2968static int fib_route_seq_show(struct seq_file *seq, void *v)
2969{
2970 struct fib_route_iter *iter = seq->private;
2971 struct fib_table *tb = iter->main_tb;
2972 struct fib_alias *fa;
2973 struct key_vector *l = v;
2974 __be32 prefix;
2975
2976 if (v == SEQ_START_TOKEN) {
2977 seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
2978 "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
2979 "\tWindow\tIRTT");
2980 return 0;
2981 }
2982
2983 prefix = htonl(l->key);
2984
2985 hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2986 struct fib_info *fi = fa->fa_info;
2987 __be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen);
2988 unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);
2989
2990 if ((fa->fa_type == RTN_BROADCAST) ||
2991 (fa->fa_type == RTN_MULTICAST))
2992 continue;
2993
2994 if (fa->tb_id != tb->tb_id)
2995 continue;
2996
2997 seq_setwidth(seq, 127);
2998
2999 if (fi) {
3000 struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
3001 __be32 gw = 0;
3002
3003 if (nhc->nhc_gw_family == AF_INET)
3004 gw = nhc->nhc_gw.ipv4;
3005
3006 seq_printf(seq,
3007 "%s\t%08X\t%08X\t%04X\t%d\t%u\t"
3008 "%d\t%08X\t%d\t%u\t%u",
3009 nhc->nhc_dev ? nhc->nhc_dev->name : "*",
3010 prefix, gw, flags, 0, 0,
3011 fi->fib_priority,
3012 mask,
3013 (fi->fib_advmss ?
3014 fi->fib_advmss + 40 : 0),
3015 fi->fib_window,
3016 fi->fib_rtt >> 3);
3017 } else {
3018 seq_printf(seq,
3019 "*\t%08X\t%08X\t%04X\t%d\t%u\t"
3020 "%d\t%08X\t%d\t%u\t%u",
3021 prefix, 0, flags, 0, 0, 0,
3022 mask, 0, 0, 0);
3023 }
3024 seq_pad(seq, '\n');
3025 }
3026
3027 return 0;
3028}
3029
3030static const struct seq_operations fib_route_seq_ops = {
3031 .start = fib_route_seq_start,
3032 .next = fib_route_seq_next,
3033 .stop = fib_route_seq_stop,
3034 .show = fib_route_seq_show,
3035};
3036
3037int __net_init fib_proc_init(struct net *net)
3038{
3039 if (!proc_create_net("fib_trie", 0444, net->proc_net, &fib_trie_seq_ops,
3040 sizeof(struct fib_trie_iter)))
3041 goto out1;
3042
3043 if (!proc_create_net_single("fib_triestat", 0444, net->proc_net,
3044 fib_triestat_seq_show, NULL))
3045 goto out2;
3046
3047 if (!proc_create_net("route", 0444, net->proc_net, &fib_route_seq_ops,
3048 sizeof(struct fib_route_iter)))
3049 goto out3;
3050
3051 return 0;
3052
3053out3:
3054 remove_proc_entry("fib_triestat", net->proc_net);
3055out2:
3056 remove_proc_entry("fib_trie", net->proc_net);
3057out1:
3058 return -ENOMEM;
3059}
3060
3061void __net_exit fib_proc_exit(struct net *net)
3062{
3063 remove_proc_entry("fib_trie", net->proc_net);
3064 remove_proc_entry("fib_triestat", net->proc_net);
3065 remove_proc_entry("route", net->proc_net);
3066}
3067
3068#endif /* CONFIG_PROC_FS */