1	// SPDX-License-Identifier: GPL-2.0-or-later
2	/*
3	*
4	* Robert Olsson <robert.olsson@its.uu.se> Uppsala Universitet
5	* & Swedish University of Agricultural Sciences.
6	*
7	* Jens Laas <jens.laas@data.slu.se> Swedish University of
8	* Agricultural Sciences.
9	*
10	* Hans Liss <hans.liss@its.uu.se> Uppsala Universitet
11	*
12	* This work is based on the LPC-trie which is originally described in:
13	*
14	* An experimental study of compression methods for dynamic tries
15	* Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002.
16	* https://www.csc.kth.se/~snilsson/software/dyntrie2/
17	*
18	* IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson
19	* IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999
20	*
21	* Code from fib_hash has been reused which includes the following header:
22	*
23	* INET An implementation of the TCP/IP protocol suite for the LINUX
24	* operating system. INET is implemented using the BSD Socket
25	* interface as the means of communication with the user level.
26	*
27	* IPv4 FIB: lookup engine and maintenance routines.
28	*
29	* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
30	*
31	* Substantial contributions to this work comes from:
32	*
33	* David S. Miller, <davem@davemloft.net>
34	* Stephen Hemminger <shemminger@osdl.org>
35	* Paul E. McKenney <paulmck@us.ibm.com>
36	* Patrick McHardy <kaber@trash.net>
37	*/
38	#include <linux/cache.h>
39	#include <linux/uaccess.h>
40	#include <linux/bitops.h>
41	#include <linux/types.h>
42	#include <linux/kernel.h>
43	#include <linux/mm.h>
44	#include <linux/string.h>
45	#include <linux/socket.h>
46	#include <linux/sockios.h>
47	#include <linux/errno.h>
48	#include <linux/in.h>
49	#include <linux/inet.h>
50	#include <linux/inetdevice.h>
51	#include <linux/netdevice.h>
52	#include <linux/if_arp.h>
53	#include <linux/proc_fs.h>
54	#include <linux/rcupdate.h>
55	#include <linux/skbuff.h>
56	#include <linux/netlink.h>
57	#include <linux/init.h>
58	#include <linux/list.h>
59	#include <linux/slab.h>
60	#include <linux/export.h>
61	#include <linux/vmalloc.h>
62	#include <linux/notifier.h>
63	#include <net/net_namespace.h>
64	#include <net/inet_dscp.h>
65	#include <net/ip.h>
66	#include <net/protocol.h>
67	#include <net/route.h>
68	#include <net/tcp.h>
69	#include <net/sock.h>
70	#include <net/ip_fib.h>
71	#include <net/fib_notifier.h>
72	#include <trace/events/fib.h>
73	#include "fib_lookup.h"
74
75	static int call_fib_entry_notifier(struct notifier_block *nb,
76	enum fib_event_type event_type, u32 dst,
77	int dst_len, struct fib_alias *fa,
78	struct netlink_ext_ack *extack)
79	{
80	struct fib_entry_notifier_info info = {
81	.info.extack = extack,
82	.dst = dst,
83	.dst_len = dst_len,
84	.fi = fa->fa_info,
85	.dscp = fa->fa_dscp,
86	.type = fa->fa_type,
87	.tb_id = fa->tb_id,
88	};
89	return call_fib4_notifier(nb, event_type, info: &info.info);
90	}
91
92	static int call_fib_entry_notifiers(struct net *net,
93	enum fib_event_type event_type, u32 dst,
94	int dst_len, struct fib_alias *fa,
95	struct netlink_ext_ack *extack)
96	{
97	struct fib_entry_notifier_info info = {
98	.info.extack = extack,
99	.dst = dst,
100	.dst_len = dst_len,
101	.fi = fa->fa_info,
102	.dscp = fa->fa_dscp,
103	.type = fa->fa_type,
104	.tb_id = fa->tb_id,
105	};
106	return call_fib4_notifiers(net, event_type, info: &info.info);
107	}
108
109	#define MAX_STAT_DEPTH 32
110
111	#define KEYLENGTH (8*sizeof(t_key))
112	#define KEY_MAX ((t_key)~0)
113
114	typedef unsigned int t_key;
115
116	#define IS_TRIE(n) ((n)->pos >= KEYLENGTH)
117	#define IS_TNODE(n) ((n)->bits)
118	#define IS_LEAF(n) (!(n)->bits)
119
120	struct key_vector {
121	t_key key;
122	unsigned char pos; /* 2log(KEYLENGTH) bits needed */
123	unsigned char bits; /* 2log(KEYLENGTH) bits needed */
124	unsigned char slen;
125	union {
126	/* This list pointer if valid if (pos | bits) == 0 (LEAF) */
127	struct hlist_head leaf;
128	/* This array is valid if (pos | bits) > 0 (TNODE) */
129	DECLARE_FLEX_ARRAY(struct key_vector __rcu *, tnode);
130	};
131	};
132
133	struct tnode {
134	struct rcu_head rcu;
135	t_key empty_children; /* KEYLENGTH bits needed */
136	t_key full_children; /* KEYLENGTH bits needed */
137	struct key_vector __rcu *parent;
138	struct key_vector kv[1];
139	#define tn_bits kv[0].bits
140	};
141
142	#define TNODE_SIZE(n) offsetof(struct tnode, kv[0].tnode[n])
143	#define LEAF_SIZE TNODE_SIZE(1)
144
145	#ifdef CONFIG_IP_FIB_TRIE_STATS
146	struct trie_use_stats {
147	unsigned int gets;
148	unsigned int backtrack;
149	unsigned int semantic_match_passed;
150	unsigned int semantic_match_miss;
151	unsigned int null_node_hit;
152	unsigned int resize_node_skipped;
153	};
154	#endif
155
156	struct trie_stat {
157	unsigned int totdepth;
158	unsigned int maxdepth;
159	unsigned int tnodes;
160	unsigned int leaves;
161	unsigned int nullpointers;
162	unsigned int prefixes;
163	unsigned int nodesizes[MAX_STAT_DEPTH];
164	};
165
166	struct trie {
167	struct key_vector kv[1];
168	#ifdef CONFIG_IP_FIB_TRIE_STATS
169	struct trie_use_stats __percpu *stats;
170	#endif
171	};
172
173	static struct key_vector *resize(struct trie *t, struct key_vector *tn);
174	static unsigned int tnode_free_size;
175
176	/*
177	* synchronize_rcu after call_rcu for outstanding dirty memory; it should be
178	* especially useful before resizing the root node with PREEMPT_NONE configs;
179	* the value was obtained experimentally, aiming to avoid visible slowdown.
180	*/
181	unsigned int sysctl_fib_sync_mem = 512 * 1024;
182	unsigned int sysctl_fib_sync_mem_min = 64 * 1024;
183	unsigned int sysctl_fib_sync_mem_max = 64 * 1024 * 1024;
184
185	static struct kmem_cache *fn_alias_kmem __ro_after_init;
186	static struct kmem_cache *trie_leaf_kmem __ro_after_init;
187
188	static inline struct tnode *tn_info(struct key_vector *kv)
189	{
190	return container_of(kv, struct tnode, kv[0]);
191	}
192
193	/* caller must hold RTNL */
194	#define node_parent(tn) rtnl_dereference(tn_info(tn)->parent)
195	#define get_child(tn, i) rtnl_dereference((tn)->tnode[i])
196
197	/* caller must hold RCU read lock or RTNL */
198	#define node_parent_rcu(tn) rcu_dereference_rtnl(tn_info(tn)->parent)
199	#define get_child_rcu(tn, i) rcu_dereference_rtnl((tn)->tnode[i])
200
201	/* wrapper for rcu_assign_pointer */
202	static inline void node_set_parent(struct key_vector *n, struct key_vector *tp)
203	{
204	if (n)
205	rcu_assign_pointer(tn_info(n)->parent, tp);
206	}
207
208	#define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER(tn_info(n)->parent, p)
209
210	/* This provides us with the number of children in this node, in the case of a
211	* leaf this will return 0 meaning none of the children are accessible.
212	*/
213	static inline unsigned long child_length(const struct key_vector *tn)
214	{
215	return (1ul << tn->bits) & ~(1ul);
216	}
217
218	#define get_cindex(key, kv) (((key) ^ (kv)->key) >> (kv)->pos)
219
220	static inline unsigned long get_index(t_key key, struct key_vector *kv)
221	{
222	unsigned long index = key ^ kv->key;
223
224	if ((BITS_PER_LONG <= KEYLENGTH) && (KEYLENGTH == kv->pos))
225	return 0;
226
227	return index >> kv->pos;
228	}
229
230	/* To understand this stuff, an understanding of keys and all their bits is
231	* necessary. Every node in the trie has a key associated with it, but not
232	* all of the bits in that key are significant.
233	*
234	* Consider a node 'n' and its parent 'tp'.
235	*
236	* If n is a leaf, every bit in its key is significant. Its presence is
237	* necessitated by path compression, since during a tree traversal (when
238	* searching for a leaf - unless we are doing an insertion) we will completely
239	* ignore all skipped bits we encounter. Thus we need to verify, at the end of
240	* a potentially successful search, that we have indeed been walking the
241	* correct key path.
242	*
243	* Note that we can never "miss" the correct key in the tree if present by
244	* following the wrong path. Path compression ensures that segments of the key
245	* that are the same for all keys with a given prefix are skipped, but the
246	* skipped part *is* identical for each node in the subtrie below the skipped
247	* bit! trie_insert() in this implementation takes care of that.
248	*
249	* if n is an internal node - a 'tnode' here, the various parts of its key
250	* have many different meanings.
251	*
252	* Example:
253	* _________________________________________________________________
254	* | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
255	* -----------------------------------------------------------------
256	* 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
257	*
258	* _________________________________________________________________
259	* | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
260	* -----------------------------------------------------------------
261	* 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
262	*
263	* tp->pos = 22
264	* tp->bits = 3
265	* n->pos = 13
266	* n->bits = 4
267	*
268	* First, let's just ignore the bits that come before the parent tp, that is
269	* the bits from (tp->pos + tp->bits) to 31. They are *known* but at this
270	* point we do not use them for anything.
271	*
272	* The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the
273	* index into the parent's child array. That is, they will be used to find
274	* 'n' among tp's children.
275	*
276	* The bits from (n->pos + n->bits) to (tp->pos - 1) - "S" - are skipped bits
277	* for the node n.
278	*
279	* All the bits we have seen so far are significant to the node n. The rest
280	* of the bits are really not needed or indeed known in n->key.
281	*
282	* The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into
283	* n's child array, and will of course be different for each child.
284	*
285	* The rest of the bits, from 0 to (n->pos -1) - "u" - are completely unknown
286	* at this point.
287	*/
288
289	static const int halve_threshold = 25;
290	static const int inflate_threshold = 50;
291	static const int halve_threshold_root = 15;
292	static const int inflate_threshold_root = 30;
293
294	static void __alias_free_mem(struct rcu_head *head)
295	{
296	struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
297	kmem_cache_free(s: fn_alias_kmem, objp: fa);
298	}
299
300	static inline void alias_free_mem_rcu(struct fib_alias *fa)
301	{
302	call_rcu(head: &fa->rcu, func: __alias_free_mem);
303	}
304
305	#define TNODE_VMALLOC_MAX \
306	ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *))
307
308	static void __node_free_rcu(struct rcu_head *head)
309	{
310	struct tnode *n = container_of(head, struct tnode, rcu);
311
312	if (!n->tn_bits)
313	kmem_cache_free(s: trie_leaf_kmem, objp: n);
314	else
315	kvfree(addr: n);
316	}
317
318	#define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu)
319
320	static struct tnode *tnode_alloc(int bits)
321	{
322	size_t size;
323
324	/* verify bits is within bounds */
325	if (bits > TNODE_VMALLOC_MAX)
326	return NULL;
327
328	/* determine size and verify it is non-zero and didn't overflow */
329	size = TNODE_SIZE(1ul << bits);
330
331	if (size <= PAGE_SIZE)
332	return kzalloc(size, GFP_KERNEL);
333	else
334	return vzalloc(size);
335	}
336
337	static inline void empty_child_inc(struct key_vector *n)
338	{
339	tn_info(kv: n)->empty_children++;
340
341	if (!tn_info(kv: n)->empty_children)
342	tn_info(kv: n)->full_children++;
343	}
344
345	static inline void empty_child_dec(struct key_vector *n)
346	{
347	if (!tn_info(kv: n)->empty_children)
348	tn_info(kv: n)->full_children--;
349
350	tn_info(kv: n)->empty_children--;
351	}
352
353	static struct key_vector *leaf_new(t_key key, struct fib_alias *fa)
354	{
355	struct key_vector *l;
356	struct tnode *kv;
357
358	kv = kmem_cache_alloc(cachep: trie_leaf_kmem, GFP_KERNEL);
359	if (!kv)
360	return NULL;
361
362	/* initialize key vector */
363	l = kv->kv;
364	l->key = key;
365	l->pos = 0;
366	l->bits = 0;
367	l->slen = fa->fa_slen;
368
369	/* link leaf to fib alias */
370	INIT_HLIST_HEAD(&l->leaf);
371	hlist_add_head(n: &fa->fa_list, h: &l->leaf);
372
373	return l;
374	}
375
376	static struct key_vector *tnode_new(t_key key, int pos, int bits)
377	{
378	unsigned int shift = pos + bits;
379	struct key_vector *tn;
380	struct tnode *tnode;
381
382	/* verify bits and pos their msb bits clear and values are valid */
383	BUG_ON(!bits || (shift > KEYLENGTH));
384
385	tnode = tnode_alloc(bits);
386	if (!tnode)
387	return NULL;
388
389	pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0),
390	sizeof(struct key_vector *) << bits);
391
392	if (bits == KEYLENGTH)
393	tnode->full_children = 1;
394	else
395	tnode->empty_children = 1ul << bits;
396
397	tn = tnode->kv;
398	tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
399	tn->pos = pos;
400	tn->bits = bits;
401	tn->slen = pos;
402
403	return tn;
404	}
405
406	/* Check whether a tnode 'n' is "full", i.e. it is an internal node
407	* and no bits are skipped. See discussion in dyntree paper p. 6
408	*/
409	static inline int tnode_full(struct key_vector *tn, struct key_vector *n)
410	{
411	return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n);
412	}
413
414	/* Add a child at position i overwriting the old value.
415	* Update the value of full_children and empty_children.
416	*/
417	static void put_child(struct key_vector *tn, unsigned long i,
418	struct key_vector *n)
419	{
420	struct key_vector *chi = get_child(tn, i);
421	int isfull, wasfull;
422
423	BUG_ON(i >= child_length(tn));
424
425	/* update emptyChildren, overflow into fullChildren */
426	if (!n && chi)
427	empty_child_inc(n: tn);
428	if (n && !chi)
429	empty_child_dec(n: tn);
430
431	/* update fullChildren */
432	wasfull = tnode_full(tn, n: chi);
433	isfull = tnode_full(tn, n);
434
435	if (wasfull && !isfull)
436	tn_info(kv: tn)->full_children--;
437	else if (!wasfull && isfull)
438	tn_info(kv: tn)->full_children++;
439
440	if (n && (tn->slen < n->slen))
441	tn->slen = n->slen;
442
443	rcu_assign_pointer(tn->tnode[i], n);
444	}
445
446	static void update_children(struct key_vector *tn)
447	{
448	unsigned long i;
449
450	/* update all of the child parent pointers */
451	for (i = child_length(tn); i;) {
452	struct key_vector *inode = get_child(tn, --i);
453
454	if (!inode)
455	continue;
456
457	/* Either update the children of a tnode that
458	* already belongs to us or update the child
459	* to point to ourselves.
460	*/
461	if (node_parent(inode) == tn)
462	update_children(tn: inode);
463	else
464	node_set_parent(n: inode, tp: tn);
465	}
466	}
467
468	static inline void put_child_root(struct key_vector *tp, t_key key,
469	struct key_vector *n)
470	{
471	if (IS_TRIE(tp))
472	rcu_assign_pointer(tp->tnode[0], n);
473	else
474	put_child(tn: tp, i: get_index(key, kv: tp), n);
475	}
476
477	static inline void tnode_free_init(struct key_vector *tn)
478	{
479	tn_info(kv: tn)->rcu.next = NULL;
480	}
481
482	static inline void tnode_free_append(struct key_vector *tn,
483	struct key_vector *n)
484	{
485	tn_info(kv: n)->rcu.next = tn_info(kv: tn)->rcu.next;
486	tn_info(kv: tn)->rcu.next = &tn_info(kv: n)->rcu;
487	}
488
489	static void tnode_free(struct key_vector *tn)
490	{
491	struct callback_head *head = &tn_info(kv: tn)->rcu;
492
493	while (head) {
494	head = head->next;
495	tnode_free_size += TNODE_SIZE(1ul << tn->bits);
496	node_free(tn);
497
498	tn = container_of(head, struct tnode, rcu)->kv;
499	}
500
501	if (tnode_free_size >= READ_ONCE(sysctl_fib_sync_mem)) {
502	tnode_free_size = 0;
503	synchronize_rcu();
504	}
505	}
506
507	static struct key_vector *replace(struct trie *t,
508	struct key_vector *oldtnode,
509	struct key_vector *tn)
510	{
511	struct key_vector *tp = node_parent(oldtnode);
512	unsigned long i;
513
514	/* setup the parent pointer out of and back into this node */
515	NODE_INIT_PARENT(tn, tp);
516	put_child_root(tp, key: tn->key, n: tn);
517
518	/* update all of the child parent pointers */
519	update_children(tn);
520
521	/* all pointers should be clean so we are done */
522	tnode_free(tn: oldtnode);
523
524	/* resize children now that oldtnode is freed */
525	for (i = child_length(tn); i;) {
526	struct key_vector *inode = get_child(tn, --i);
527
528	/* resize child node */
529	if (tnode_full(tn, n: inode))
530	tn = resize(t, tn: inode);
531	}
532
533	return tp;
534	}
535
536	static struct key_vector *inflate(struct trie *t,
537	struct key_vector *oldtnode)
538	{
539	struct key_vector *tn;
540	unsigned long i;
541	t_key m;
542
543	pr_debug("In inflate\n");
544
545	tn = tnode_new(key: oldtnode->key, pos: oldtnode->pos - 1, bits: oldtnode->bits + 1);
546	if (!tn)
547	goto notnode;
548
549	/* prepare oldtnode to be freed */
550	tnode_free_init(tn: oldtnode);
551
552	/* Assemble all of the pointers in our cluster, in this case that
553	* represents all of the pointers out of our allocated nodes that
554	* point to existing tnodes and the links between our allocated
555	* nodes.
556	*/
557	for (i = child_length(tn: oldtnode), m = 1u << tn->pos; i;) {
558	struct key_vector *inode = get_child(oldtnode, --i);
559	struct key_vector *node0, *node1;
560	unsigned long j, k;
561
562	/* An empty child */
563	if (!inode)
564	continue;
565
566	/* A leaf or an internal node with skipped bits */
567	if (!tnode_full(tn: oldtnode, n: inode)) {
568	put_child(tn, i: get_index(key: inode->key, kv: tn), n: inode);
569	continue;
570	}
571
572	/* drop the node in the old tnode free list */
573	tnode_free_append(tn: oldtnode, n: inode);
574
575	/* An internal node with two children */
576	if (inode->bits == 1) {
577	put_child(tn, i: 2 * i + 1, get_child(inode, 1));
578	put_child(tn, i: 2 * i, get_child(inode, 0));
579	continue;
580	}
581
582	/* We will replace this node 'inode' with two new
583	* ones, 'node0' and 'node1', each with half of the
584	* original children. The two new nodes will have
585	* a position one bit further down the key and this
586	* means that the "significant" part of their keys
587	* (see the discussion near the top of this file)
588	* will differ by one bit, which will be "0" in
589	* node0's key and "1" in node1's key. Since we are
590	* moving the key position by one step, the bit that
591	* we are moving away from - the bit at position
592	* (tn->pos) - is the one that will differ between
593	* node0 and node1. So... we synthesize that bit in the
594	* two new keys.
595	*/
596	node1 = tnode_new(key: inode->key | m, pos: inode->pos, bits: inode->bits - 1);
597	if (!node1)
598	goto nomem;
599	node0 = tnode_new(key: inode->key, pos: inode->pos, bits: inode->bits - 1);
600
601	tnode_free_append(tn, n: node1);
602	if (!node0)
603	goto nomem;
604	tnode_free_append(tn, n: node0);
605
606	/* populate child pointers in new nodes */
607	for (k = child_length(tn: inode), j = k / 2; j;) {
608	put_child(tn: node1, i: --j, get_child(inode, --k));
609	put_child(tn: node0, i: j, get_child(inode, j));
610	put_child(tn: node1, i: --j, get_child(inode, --k));
611	put_child(tn: node0, i: j, get_child(inode, j));
612	}
613
614	/* link new nodes to parent */
615	NODE_INIT_PARENT(node1, tn);
616	NODE_INIT_PARENT(node0, tn);
617
618	/* link parent to nodes */
619	put_child(tn, i: 2 * i + 1, n: node1);
620	put_child(tn, i: 2 * i, n: node0);
621	}
622
623	/* setup the parent pointers into and out of this node */
624	return replace(t, oldtnode, tn);
625	nomem:
626	/* all pointers should be clean so we are done */
627	tnode_free(tn);
628	notnode:
629	return NULL;
630	}
631
632	static struct key_vector *halve(struct trie *t,
633	struct key_vector *oldtnode)
634	{
635	struct key_vector *tn;
636	unsigned long i;
637
638	pr_debug("In halve\n");
639
640	tn = tnode_new(key: oldtnode->key, pos: oldtnode->pos + 1, bits: oldtnode->bits - 1);
641	if (!tn)
642	goto notnode;
643
644	/* prepare oldtnode to be freed */
645	tnode_free_init(tn: oldtnode);
646
647	/* Assemble all of the pointers in our cluster, in this case that
648	* represents all of the pointers out of our allocated nodes that
649	* point to existing tnodes and the links between our allocated
650	* nodes.
651	*/
652	for (i = child_length(tn: oldtnode); i;) {
653	struct key_vector *node1 = get_child(oldtnode, --i);
654	struct key_vector *node0 = get_child(oldtnode, --i);
655	struct key_vector *inode;
656
657	/* At least one of the children is empty */
658	if (!node1 || !node0) {
659	put_child(tn, i: i / 2, n: node1 ? : node0);
660	continue;
661	}
662
663	/* Two nonempty children */
664	inode = tnode_new(key: node0->key, pos: oldtnode->pos, bits: 1);
665	if (!inode)
666	goto nomem;
667	tnode_free_append(tn, n: inode);
668
669	/* initialize pointers out of node */
670	put_child(tn: inode, i: 1, n: node1);
671	put_child(tn: inode, i: 0, n: node0);
672	NODE_INIT_PARENT(inode, tn);
673
674	/* link parent to node */
675	put_child(tn, i: i / 2, n: inode);
676	}
677
678	/* setup the parent pointers into and out of this node */
679	return replace(t, oldtnode, tn);
680	nomem:
681	/* all pointers should be clean so we are done */
682	tnode_free(tn);
683	notnode:
684	return NULL;
685	}
686
687	static struct key_vector *collapse(struct trie *t,
688	struct key_vector *oldtnode)
689	{
690	struct key_vector *n, *tp;
691	unsigned long i;
692
693	/* scan the tnode looking for that one child that might still exist */
694	for (n = NULL, i = child_length(tn: oldtnode); !n && i;)
695	n = get_child(oldtnode, --i);
696
697	/* compress one level */
698	tp = node_parent(oldtnode);
699	put_child_root(tp, key: oldtnode->key, n);
700	node_set_parent(n, tp);
701
702	/* drop dead node */
703	node_free(oldtnode);
704
705	return tp;
706	}
707
708	static unsigned char update_suffix(struct key_vector *tn)
709	{
710	unsigned char slen = tn->pos;
711	unsigned long stride, i;
712	unsigned char slen_max;
713
714	/* only vector 0 can have a suffix length greater than or equal to
715	* tn->pos + tn->bits, the second highest node will have a suffix
716	* length at most of tn->pos + tn->bits - 1
717	*/
718	slen_max = min_t(unsigned char, tn->pos + tn->bits - 1, tn->slen);
719
720	/* search though the list of children looking for nodes that might
721	* have a suffix greater than the one we currently have. This is
722	* why we start with a stride of 2 since a stride of 1 would
723	* represent the nodes with suffix length equal to tn->pos
724	*/
725	for (i = 0, stride = 0x2ul ; i < child_length(tn); i += stride) {
726	struct key_vector *n = get_child(tn, i);
727
728	if (!n || (n->slen <= slen))
729	continue;
730
731	/* update stride and slen based on new value */
732	stride <<= (n->slen - slen);
733	slen = n->slen;
734	i &= ~(stride - 1);
735
736	/* stop searching if we have hit the maximum possible value */
737	if (slen >= slen_max)
738	break;
739	}
740
741	tn->slen = slen;
742
743	return slen;
744	}
745
746	/* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
747	* the Helsinki University of Technology and Matti Tikkanen of Nokia
748	* Telecommunications, page 6:
749	* "A node is doubled if the ratio of non-empty children to all
750	* children in the *doubled* node is at least 'high'."
751	*
752	* 'high' in this instance is the variable 'inflate_threshold'. It
753	* is expressed as a percentage, so we multiply it with
754	* child_length() and instead of multiplying by 2 (since the
755	* child array will be doubled by inflate()) and multiplying
756	* the left-hand side by 100 (to handle the percentage thing) we
757	* multiply the left-hand side by 50.
758	*
759	* The left-hand side may look a bit weird: child_length(tn)
760	* - tn->empty_children is of course the number of non-null children
761	* in the current node. tn->full_children is the number of "full"
762	* children, that is non-null tnodes with a skip value of 0.
763	* All of those will be doubled in the resulting inflated tnode, so
764	* we just count them one extra time here.
765	*
766	* A clearer way to write this would be:
767	*
768	* to_be_doubled = tn->full_children;
769	* not_to_be_doubled = child_length(tn) - tn->empty_children -
770	* tn->full_children;
771	*
772	* new_child_length = child_length(tn) * 2;
773	*
774	* new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
775	* new_child_length;
776	* if (new_fill_factor >= inflate_threshold)
777	*
778	* ...and so on, tho it would mess up the while () loop.
779	*
780	* anyway,
781	* 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
782	* inflate_threshold
783	*
784	* avoid a division:
785	* 100 * (not_to_be_doubled + 2*to_be_doubled) >=
786	* inflate_threshold * new_child_length
787	*
788	* expand not_to_be_doubled and to_be_doubled, and shorten:
789	* 100 * (child_length(tn) - tn->empty_children +
790	* tn->full_children) >= inflate_threshold * new_child_length
791	*
792	* expand new_child_length:
793	* 100 * (child_length(tn) - tn->empty_children +
794	* tn->full_children) >=
795	* inflate_threshold * child_length(tn) * 2
796	*
797	* shorten again:
798	* 50 * (tn->full_children + child_length(tn) -
799	* tn->empty_children) >= inflate_threshold *
800	* child_length(tn)
801	*
802	*/
803	static inline bool should_inflate(struct key_vector *tp, struct key_vector *tn)
804	{
805	unsigned long used = child_length(tn);
806	unsigned long threshold = used;
807
808	/* Keep root node larger */
809	threshold *= IS_TRIE(tp) ? inflate_threshold_root : inflate_threshold;
810	used -= tn_info(kv: tn)->empty_children;
811	used += tn_info(kv: tn)->full_children;
812
813	/* if bits == KEYLENGTH then pos = 0, and will fail below */
814
815	return (used > 1) && tn->pos && ((50 * used) >= threshold);
816	}
817
818	static inline bool should_halve(struct key_vector *tp, struct key_vector *tn)
819	{
820	unsigned long used = child_length(tn);
821	unsigned long threshold = used;
822
823	/* Keep root node larger */
824	threshold *= IS_TRIE(tp) ? halve_threshold_root : halve_threshold;
825	used -= tn_info(kv: tn)->empty_children;
826
827	/* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */
828
829	return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold);
830	}
831
832	static inline bool should_collapse(struct key_vector *tn)
833	{
834	unsigned long used = child_length(tn);
835
836	used -= tn_info(kv: tn)->empty_children;
837
838	/* account for bits == KEYLENGTH case */
839	if ((tn->bits == KEYLENGTH) && tn_info(kv: tn)->full_children)
840	used -= KEY_MAX;
841
842	/* One child or none, time to drop us from the trie */
843	return used < 2;
844	}
845
846	#define MAX_WORK 10
847	static struct key_vector *resize(struct trie *t, struct key_vector *tn)
848	{
849	#ifdef CONFIG_IP_FIB_TRIE_STATS
850	struct trie_use_stats __percpu *stats = t->stats;
851	#endif
852	struct key_vector *tp = node_parent(tn);
853	unsigned long cindex = get_index(key: tn->key, kv: tp);
854	int max_work = MAX_WORK;
855
856	pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
857	tn, inflate_threshold, halve_threshold);
858
859	/* track the tnode via the pointer from the parent instead of
860	* doing it ourselves. This way we can let RCU fully do its
861	* thing without us interfering
862	*/
863	BUG_ON(tn != get_child(tp, cindex));
864
865	/* Double as long as the resulting node has a number of
866	* nonempty nodes that are above the threshold.
867	*/
868	while (should_inflate(tp, tn) && max_work) {
869	tp = inflate(t, oldtnode: tn);
870	if (!tp) {
871	#ifdef CONFIG_IP_FIB_TRIE_STATS
872	this_cpu_inc(stats->resize_node_skipped);
873	#endif
874	break;
875	}
876
877	max_work--;
878	tn = get_child(tp, cindex);
879	}
880
881	/* update parent in case inflate failed */
882	tp = node_parent(tn);
883
884	/* Return if at least one inflate is run */
885	if (max_work != MAX_WORK)
886	return tp;
887
888	/* Halve as long as the number of empty children in this
889	* node is above threshold.
890	*/
891	while (should_halve(tp, tn) && max_work) {
892	tp = halve(t, oldtnode: tn);
893	if (!tp) {
894	#ifdef CONFIG_IP_FIB_TRIE_STATS
895	this_cpu_inc(stats->resize_node_skipped);
896	#endif
897	break;
898	}
899
900	max_work--;
901	tn = get_child(tp, cindex);
902	}
903
904	/* Only one child remains */
905	if (should_collapse(tn))
906	return collapse(t, oldtnode: tn);
907
908	/* update parent in case halve failed */
909	return node_parent(tn);
910	}
911
912	static void node_pull_suffix(struct key_vector *tn, unsigned char slen)
913	{
914	unsigned char node_slen = tn->slen;
915
916	while ((node_slen > tn->pos) && (node_slen > slen)) {
917	slen = update_suffix(tn);
918	if (node_slen == slen)
919	break;
920
921	tn = node_parent(tn);
922	node_slen = tn->slen;
923	}
924	}
925
926	static void node_push_suffix(struct key_vector *tn, unsigned char slen)
927	{
928	while (tn->slen < slen) {
929	tn->slen = slen;
930	tn = node_parent(tn);
931	}
932	}
933
934	/* rcu_read_lock needs to be hold by caller from readside */
935	static struct key_vector *fib_find_node(struct trie *t,
936	struct key_vector **tp, u32 key)
937	{
938	struct key_vector *pn, *n = t->kv;
939	unsigned long index = 0;
940
941	do {
942	pn = n;
943	n = get_child_rcu(n, index);
944
945	if (!n)
946	break;
947
948	index = get_cindex(key, n);
949
950	/* This bit of code is a bit tricky but it combines multiple
951	* checks into a single check. The prefix consists of the
952	* prefix plus zeros for the bits in the cindex. The index
953	* is the difference between the key and this value. From
954	* this we can actually derive several pieces of data.
955	* if (index >= (1ul << bits))
956	* we have a mismatch in skip bits and failed
957	* else
958	* we know the value is cindex
959	*
960	* This check is safe even if bits == KEYLENGTH due to the
961	* fact that we can only allocate a node with 32 bits if a
962	* long is greater than 32 bits.
963	*/
964	if (index >= (1ul << n->bits)) {
965	n = NULL;
966	break;
967	}
968
969	/* keep searching until we find a perfect match leaf or NULL */
970	} while (IS_TNODE(n));
971
972	*tp = pn;
973
974	return n;
975	}
976
977	/* Return the first fib alias matching DSCP with
978	* priority less than or equal to PRIO.
979	* If 'find_first' is set, return the first matching
980	* fib alias, regardless of DSCP and priority.
981	*/
982	static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen,
983	dscp_t dscp, u32 prio, u32 tb_id,
984	bool find_first)
985	{
986	struct fib_alias *fa;
987
988	if (!fah)
989	return NULL;
990
991	hlist_for_each_entry(fa, fah, fa_list) {
992	/* Avoid Sparse warning when using dscp_t in inequalities */
993	u8 __fa_dscp = inet_dscp_to_dsfield(fa->fa_dscp);
994	u8 __dscp = inet_dscp_to_dsfield(dscp);
995
996	if (fa->fa_slen < slen)
997	continue;
998	if (fa->fa_slen != slen)
999	break;
1000	if (fa->tb_id > tb_id)
1001	continue;
1002	if (fa->tb_id != tb_id)
1003	break;
1004	if (find_first)
1005	return fa;
1006	if (__fa_dscp > __dscp)
1007	continue;
1008	if (fa->fa_info->fib_priority >= prio || __fa_dscp < __dscp)
1009	return fa;
1010	}
1011
1012	return NULL;
1013	}
1014
1015	static struct fib_alias *
1016	fib_find_matching_alias(struct net *net, const struct fib_rt_info *fri)
1017	{
1018	u8 slen = KEYLENGTH - fri->dst_len;
1019	struct key_vector *l, *tp;
1020	struct fib_table *tb;
1021	struct fib_alias *fa;
1022	struct trie *t;
1023
1024	tb = fib_get_table(net, id: fri->tb_id);
1025	if (!tb)
1026	return NULL;
1027
1028	t = (struct trie *)tb->tb_data;
1029	l = fib_find_node(t, &tp, be32_to_cpu(fri->dst));
1030	if (!l)
1031	return NULL;
1032
1033	hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
1034	if (fa->fa_slen == slen && fa->tb_id == fri->tb_id &&
1035	fa->fa_dscp == fri->dscp && fa->fa_info == fri->fi &&
1036	fa->fa_type == fri->type)
1037	return fa;
1038	}
1039
1040	return NULL;
1041	}
1042
1043	void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri)
1044	{
1045	u8 fib_notify_on_flag_change;
1046	struct fib_alias *fa_match;
1047	struct sk_buff *skb;
1048	int err;
1049
1050	rcu_read_lock();
1051
1052	fa_match = fib_find_matching_alias(net, fri);
1053	if (!fa_match)
1054	goto out;
1055
1056	/* These are paired with the WRITE_ONCE() happening in this function.
1057	* The reason is that we are only protected by RCU at this point.
1058	*/
1059	if (READ_ONCE(fa_match->offload) == fri->offload &&
1060	READ_ONCE(fa_match->trap) == fri->trap &&
1061	READ_ONCE(fa_match->offload_failed) == fri->offload_failed)
1062	goto out;
1063
1064	WRITE_ONCE(fa_match->offload, fri->offload);
1065	WRITE_ONCE(fa_match->trap, fri->trap);
1066
1067	fib_notify_on_flag_change = READ_ONCE(net->ipv4.sysctl_fib_notify_on_flag_change);
1068
1069	/* 2 means send notifications only if offload_failed was changed. */
1070	if (fib_notify_on_flag_change == 2 &&
1071	READ_ONCE(fa_match->offload_failed) == fri->offload_failed)
1072	goto out;
1073
1074	WRITE_ONCE(fa_match->offload_failed, fri->offload_failed);
1075
1076	if (!fib_notify_on_flag_change)
1077	goto out;
1078
1079	skb = nlmsg_new(payload: fib_nlmsg_size(fi: fa_match->fa_info), GFP_ATOMIC);
1080	if (!skb) {
1081	err = -ENOBUFS;
1082	goto errout;
1083	}
1084
1085	err = fib_dump_info(skb, pid: 0, seq: 0, RTM_NEWROUTE, fri, flags: 0);
1086	if (err < 0) {
1087	/* -EMSGSIZE implies BUG in fib_nlmsg_size() */
1088	WARN_ON(err == -EMSGSIZE);
1089	kfree_skb(skb);
1090	goto errout;
1091	}
1092
1093	rtnl_notify(skb, net, pid: 0, RTNLGRP_IPV4_ROUTE, NULL, GFP_ATOMIC);
1094	goto out;
1095
1096	errout:
1097	rtnl_set_sk_err(net, RTNLGRP_IPV4_ROUTE, error: err);
1098	out:
1099	rcu_read_unlock();
1100	}
1101	EXPORT_SYMBOL_GPL(fib_alias_hw_flags_set);
1102
1103	static void trie_rebalance(struct trie *t, struct key_vector *tn)
1104	{
1105	while (!IS_TRIE(tn))
1106	tn = resize(t, tn);
1107	}
1108
1109	static int fib_insert_node(struct trie *t, struct key_vector *tp,
1110	struct fib_alias *new, t_key key)
1111	{
1112	struct key_vector *n, *l;
1113
1114	l = leaf_new(key, fa: new);
1115	if (!l)
1116	goto noleaf;
1117
1118	/* retrieve child from parent node */
1119	n = get_child(tp, get_index(key, tp));
1120
1121	/* Case 2: n is a LEAF or a TNODE and the key doesn't match.
1122	*
1123	* Add a new tnode here
1124	* first tnode need some special handling
1125	* leaves us in position for handling as case 3
1126	*/
1127	if (n) {
1128	struct key_vector *tn;
1129
1130	tn = tnode_new(key, pos: __fls(word: key ^ n->key), bits: 1);
1131	if (!tn)
1132	goto notnode;
1133
1134	/* initialize routes out of node */
1135	NODE_INIT_PARENT(tn, tp);
1136	put_child(tn, i: get_index(key, kv: tn) ^ 1, n);
1137
1138	/* start adding routes into the node */
1139	put_child_root(tp, key, n: tn);
1140	node_set_parent(n, tp: tn);
1141
1142	/* parent now has a NULL spot where the leaf can go */
1143	tp = tn;
1144	}
1145
1146	/* Case 3: n is NULL, and will just insert a new leaf */
1147	node_push_suffix(tn: tp, slen: new->fa_slen);
1148	NODE_INIT_PARENT(l, tp);
1149	put_child_root(tp, key, n: l);
1150	trie_rebalance(t, tn: tp);
1151
1152	return 0;
1153	notnode:
1154	node_free(l);
1155	noleaf:
1156	return -ENOMEM;
1157	}
1158
1159	static int fib_insert_alias(struct trie *t, struct key_vector *tp,
1160	struct key_vector *l, struct fib_alias *new,
1161	struct fib_alias *fa, t_key key)
1162	{
1163	if (!l)
1164	return fib_insert_node(t, tp, new, key);
1165
1166	if (fa) {
1167	hlist_add_before_rcu(n: &new->fa_list, next: &fa->fa_list);
1168	} else {
1169	struct fib_alias *last;
1170
1171	hlist_for_each_entry(last, &l->leaf, fa_list) {
1172	if (new->fa_slen < last->fa_slen)
1173	break;
1174	if ((new->fa_slen == last->fa_slen) &&
1175	(new->tb_id > last->tb_id))
1176	break;
1177	fa = last;
1178	}
1179
1180	if (fa)
1181	hlist_add_behind_rcu(n: &new->fa_list, prev: &fa->fa_list);
1182	else
1183	hlist_add_head_rcu(n: &new->fa_list, h: &l->leaf);
1184	}
1185
1186	/* if we added to the tail node then we need to update slen */
1187	if (l->slen < new->fa_slen) {
1188	l->slen = new->fa_slen;
1189	node_push_suffix(tn: tp, slen: new->fa_slen);
1190	}
1191
1192	return 0;
1193	}
1194
1195	static bool fib_valid_key_len(u32 key, u8 plen, struct netlink_ext_ack *extack)
1196	{
1197	if (plen > KEYLENGTH) {
1198	NL_SET_ERR_MSG(extack, "Invalid prefix length");
1199	return false;
1200	}
1201
1202	if ((plen < KEYLENGTH) && (key << plen)) {
1203	NL_SET_ERR_MSG(extack,
1204	"Invalid prefix for given prefix length");
1205	return false;
1206	}
1207
1208	return true;
1209	}
1210
1211	static void fib_remove_alias(struct trie *t, struct key_vector *tp,
1212	struct key_vector *l, struct fib_alias *old);
1213
1214	/* Caller must hold RTNL. */
1215	int fib_table_insert(struct net *net, struct fib_table *tb,
1216	struct fib_config *cfg, struct netlink_ext_ack *extack)
1217	{
1218	struct trie *t = (struct trie *)tb->tb_data;
1219	struct fib_alias *fa, *new_fa;
1220	struct key_vector *l, *tp;
1221	u16 nlflags = NLM_F_EXCL;
1222	struct fib_info *fi;
1223	u8 plen = cfg->fc_dst_len;
1224	u8 slen = KEYLENGTH - plen;
1225	dscp_t dscp;
1226	u32 key;
1227	int err;
1228
1229	key = ntohl(cfg->fc_dst);
1230
1231	if (!fib_valid_key_len(key, plen, extack))
1232	return -EINVAL;
1233
1234	pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
1235
1236	fi = fib_create_info(cfg, extack);
1237	if (IS_ERR(ptr: fi)) {
1238	err = PTR_ERR(ptr: fi);
1239	goto err;
1240	}
1241
1242	dscp = cfg->fc_dscp;
1243	l = fib_find_node(t, tp: &tp, key);
1244	fa = l ? fib_find_alias(&l->leaf, slen, dscp, fi->fib_priority,
1245	tb->tb_id, false) : NULL;
1246
1247	/* Now fa, if non-NULL, points to the first fib alias
1248	* with the same keys [prefix,dscp,priority], if such key already
1249	* exists or to the node before which we will insert new one.
1250	*
1251	* If fa is NULL, we will need to allocate a new one and
1252	* insert to the tail of the section matching the suffix length
1253	* of the new alias.
1254	*/
1255
1256	if (fa && fa->fa_dscp == dscp &&
1257	fa->fa_info->fib_priority == fi->fib_priority) {
1258	struct fib_alias *fa_first, *fa_match;
1259
1260	err = -EEXIST;
1261	if (cfg->fc_nlflags & NLM_F_EXCL)
1262	goto out;
1263
1264	nlflags &= ~NLM_F_EXCL;
1265
1266	/* We have 2 goals:
1267	* 1. Find exact match for type, scope, fib_info to avoid
1268	* duplicate routes
1269	* 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
1270	*/
1271	fa_match = NULL;
1272	fa_first = fa;
1273	hlist_for_each_entry_from(fa, fa_list) {
1274	if ((fa->fa_slen != slen) ||
1275	(fa->tb_id != tb->tb_id) ||
1276	(fa->fa_dscp != dscp))
1277	break;
1278	if (fa->fa_info->fib_priority != fi->fib_priority)
1279	break;
1280	if (fa->fa_type == cfg->fc_type &&
1281	fa->fa_info == fi) {
1282	fa_match = fa;
1283	break;
1284	}
1285	}
1286
1287	if (cfg->fc_nlflags & NLM_F_REPLACE) {
1288	struct fib_info *fi_drop;
1289	u8 state;
1290
1291	nlflags |= NLM_F_REPLACE;
1292	fa = fa_first;
1293	if (fa_match) {
1294	if (fa == fa_match)
1295	err = 0;
1296	goto out;
1297	}
1298	err = -ENOBUFS;
1299	new_fa = kmem_cache_alloc(cachep: fn_alias_kmem, GFP_KERNEL);
1300	if (!new_fa)
1301	goto out;
1302
1303	fi_drop = fa->fa_info;
1304	new_fa->fa_dscp = fa->fa_dscp;
1305	new_fa->fa_info = fi;
1306	new_fa->fa_type = cfg->fc_type;
1307	state = fa->fa_state;
1308	new_fa->fa_state = state & ~FA_S_ACCESSED;
1309	new_fa->fa_slen = fa->fa_slen;
1310	new_fa->tb_id = tb->tb_id;
1311	new_fa->fa_default = -1;
1312	new_fa->offload = 0;
1313	new_fa->trap = 0;
1314	new_fa->offload_failed = 0;
1315
1316	hlist_replace_rcu(old: &fa->fa_list, new: &new_fa->fa_list);
1317
1318	if (fib_find_alias(&l->leaf, fa->fa_slen, 0, 0,
1319	tb->tb_id, true) == new_fa) {
1320	enum fib_event_type fib_event;
1321
1322	fib_event = FIB_EVENT_ENTRY_REPLACE;
1323	err = call_fib_entry_notifiers(net, fib_event,
1324	key, plen,
1325	new_fa, extack);
1326	if (err) {
1327	hlist_replace_rcu(old: &new_fa->fa_list,
1328	new: &fa->fa_list);
1329	goto out_free_new_fa;
1330	}
1331	}
1332
1333	rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
1334	tb->tb_id, &cfg->fc_nlinfo, nlflags);
1335
1336	alias_free_mem_rcu(fa);
1337
1338	fib_release_info(fi_drop);
1339	if (state & FA_S_ACCESSED)
1340	rt_cache_flush(net: cfg->fc_nlinfo.nl_net);
1341
1342	goto succeeded;
1343	}
1344	/* Error if we find a perfect match which
1345	* uses the same scope, type, and nexthop
1346	* information.
1347	*/
1348	if (fa_match)
1349	goto out;
1350
1351	if (cfg->fc_nlflags & NLM_F_APPEND)
1352	nlflags |= NLM_F_APPEND;
1353	else
1354	fa = fa_first;
1355	}
1356	err = -ENOENT;
1357	if (!(cfg->fc_nlflags & NLM_F_CREATE))
1358	goto out;
1359
1360	nlflags |= NLM_F_CREATE;
1361	err = -ENOBUFS;
1362	new_fa = kmem_cache_alloc(cachep: fn_alias_kmem, GFP_KERNEL);
1363	if (!new_fa)
1364	goto out;
1365
1366	new_fa->fa_info = fi;
1367	new_fa->fa_dscp = dscp;
1368	new_fa->fa_type = cfg->fc_type;
1369	new_fa->fa_state = 0;
1370	new_fa->fa_slen = slen;
1371	new_fa->tb_id = tb->tb_id;
1372	new_fa->fa_default = -1;
1373	new_fa->offload = 0;
1374	new_fa->trap = 0;
1375	new_fa->offload_failed = 0;
1376
1377	/* Insert new entry to the list. */
1378	err = fib_insert_alias(t, tp, l, new: new_fa, fa, key);
1379	if (err)
1380	goto out_free_new_fa;
1381
1382	/* The alias was already inserted, so the node must exist. */
1383	l = l ? l : fib_find_node(t, tp: &tp, key);
1384	if (WARN_ON_ONCE(!l)) {
1385	err = -ENOENT;
1386	goto out_free_new_fa;
1387	}
1388
1389	if (fib_find_alias(&l->leaf, new_fa->fa_slen, 0, 0, tb->tb_id, true) ==
1390	new_fa) {
1391	enum fib_event_type fib_event;
1392
1393	fib_event = FIB_EVENT_ENTRY_REPLACE;
1394	err = call_fib_entry_notifiers(net, fib_event, key, plen,
1395	new_fa, extack);
1396	if (err)
1397	goto out_remove_new_fa;
1398	}
1399
1400	if (!plen)
1401	tb->tb_num_default++;
1402
1403	rt_cache_flush(net: cfg->fc_nlinfo.nl_net);
1404	rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, new_fa->tb_id,
1405	&cfg->fc_nlinfo, nlflags);
1406	succeeded:
1407	return 0;
1408
1409	out_remove_new_fa:
1410	fib_remove_alias(t, tp, l, old: new_fa);
1411	out_free_new_fa:
1412	kmem_cache_free(s: fn_alias_kmem, objp: new_fa);
1413	out:
1414	fib_release_info(fi);
1415	err:
1416	return err;
1417	}
1418
1419	static inline t_key prefix_mismatch(t_key key, struct key_vector *n)
1420	{
1421	t_key prefix = n->key;
1422
1423	return (key ^ prefix) & (prefix | -prefix);
1424	}
1425
1426	bool fib_lookup_good_nhc(const struct fib_nh_common *nhc, int fib_flags,
1427	const struct flowi4 *flp)
1428	{
1429	if (nhc->nhc_flags & RTNH_F_DEAD)
1430	return false;
1431
1432	if (ip_ignore_linkdown(dev: nhc->nhc_dev) &&
1433	nhc->nhc_flags & RTNH_F_LINKDOWN &&
1434	!(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE))
1435	return false;
1436
1437	if (flp->flowi4_oif && flp->flowi4_oif != nhc->nhc_oif)
1438	return false;
1439
1440	return true;
1441	}
1442
1443	/* should be called with rcu_read_lock */
1444	int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
1445	struct fib_result *res, int fib_flags)
1446	{
1447	struct trie *t = (struct trie *) tb->tb_data;
1448	#ifdef CONFIG_IP_FIB_TRIE_STATS
1449	struct trie_use_stats __percpu *stats = t->stats;
1450	#endif
1451	const t_key key = ntohl(flp->daddr);
1452	struct key_vector *n, *pn;
1453	struct fib_alias *fa;
1454	unsigned long index;
1455	t_key cindex;
1456
1457	pn = t->kv;
1458	cindex = 0;
1459
1460	n = get_child_rcu(pn, cindex);
1461	if (!n) {
1462	trace_fib_table_lookup(tb->tb_id, flp, NULL, -EAGAIN);
1463	return -EAGAIN;
1464	}
1465
1466	#ifdef CONFIG_IP_FIB_TRIE_STATS
1467	this_cpu_inc(stats->gets);
1468	#endif
1469
1470	/* Step 1: Travel to the longest prefix match in the trie */
1471	for (;;) {
1472	index = get_cindex(key, n);
1473
1474	/* This bit of code is a bit tricky but it combines multiple
1475	* checks into a single check. The prefix consists of the
1476	* prefix plus zeros for the "bits" in the prefix. The index
1477	* is the difference between the key and this value. From
1478	* this we can actually derive several pieces of data.
1479	* if (index >= (1ul << bits))
1480	* we have a mismatch in skip bits and failed
1481	* else
1482	* we know the value is cindex
1483	*
1484	* This check is safe even if bits == KEYLENGTH due to the
1485	* fact that we can only allocate a node with 32 bits if a
1486	* long is greater than 32 bits.
1487	*/
1488	if (index >= (1ul << n->bits))
1489	break;
1490
1491	/* we have found a leaf. Prefixes have already been compared */
1492	if (IS_LEAF(n))
1493	goto found;
1494
1495	/* only record pn and cindex if we are going to be chopping
1496	* bits later. Otherwise we are just wasting cycles.
1497	*/
1498	if (n->slen > n->pos) {
1499	pn = n;
1500	cindex = index;
1501	}
1502
1503	n = get_child_rcu(n, index);
1504	if (unlikely(!n))
1505	goto backtrace;
1506	}
1507
1508	/* Step 2: Sort out leaves and begin backtracing for longest prefix */
1509	for (;;) {
1510	/* record the pointer where our next node pointer is stored */
1511	struct key_vector __rcu **cptr = n->tnode;
1512
1513	/* This test verifies that none of the bits that differ
1514	* between the key and the prefix exist in the region of
1515	* the lsb and higher in the prefix.
1516	*/
1517	if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos))
1518	goto backtrace;
1519
1520	/* exit out and process leaf */
1521	if (unlikely(IS_LEAF(n)))
1522	break;
1523
1524	/* Don't bother recording parent info. Since we are in
1525	* prefix match mode we will have to come back to wherever
1526	* we started this traversal anyway
1527	*/
1528
1529	while ((n = rcu_dereference(*cptr)) == NULL) {
1530	backtrace:
1531	#ifdef CONFIG_IP_FIB_TRIE_STATS
1532	if (!n)
1533	this_cpu_inc(stats->null_node_hit);
1534	#endif
1535	/* If we are at cindex 0 there are no more bits for
1536	* us to strip at this level so we must ascend back
1537	* up one level to see if there are any more bits to
1538	* be stripped there.
1539	*/
1540	while (!cindex) {
1541	t_key pkey = pn->key;
1542
1543	/* If we don't have a parent then there is
1544	* nothing for us to do as we do not have any
1545	* further nodes to parse.
1546	*/
1547	if (IS_TRIE(pn)) {
1548	trace_fib_table_lookup(tb->tb_id, flp,
1549	NULL, -EAGAIN);
1550	return -EAGAIN;
1551	}
1552	#ifdef CONFIG_IP_FIB_TRIE_STATS
1553	this_cpu_inc(stats->backtrack);
1554	#endif
1555	/* Get Child's index */
1556	pn = node_parent_rcu(pn);
1557	cindex = get_index(key: pkey, kv: pn);
1558	}
1559
1560	/* strip the least significant bit from the cindex */
1561	cindex &= cindex - 1;
1562
1563	/* grab pointer for next child node */
1564	cptr = &pn->tnode[cindex];
1565	}
1566	}
1567
1568	found:
1569	/* this line carries forward the xor from earlier in the function */
1570	index = key ^ n->key;
1571
1572	/* Step 3: Process the leaf, if that fails fall back to backtracing */
1573	hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
1574	struct fib_info *fi = fa->fa_info;
1575	struct fib_nh_common *nhc;
1576	int nhsel, err;
1577
1578	if ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen < KEYLENGTH)) {
1579	if (index >= (1ul << fa->fa_slen))
1580	continue;
1581	}
1582	if (fa->fa_dscp &&
1583	inet_dscp_to_dsfield(fa->fa_dscp) != flp->flowi4_tos)
1584	continue;
1585	if (fi->fib_dead)
1586	continue;
1587	if (fa->fa_info->fib_scope < flp->flowi4_scope)
1588	continue;
1589	fib_alias_accessed(fa);
1590	err = fib_props[fa->fa_type].error;
1591	if (unlikely(err < 0)) {
1592	out_reject:
1593	#ifdef CONFIG_IP_FIB_TRIE_STATS
1594	this_cpu_inc(stats->semantic_match_passed);
1595	#endif
1596	trace_fib_table_lookup(tb_id: tb->tb_id, flp, NULL, err);
1597	return err;
1598	}
1599	if (fi->fib_flags & RTNH_F_DEAD)
1600	continue;
1601
1602	if (unlikely(fi->nh)) {
1603	if (nexthop_is_blackhole(nh: fi->nh)) {
1604	err = fib_props[RTN_BLACKHOLE].error;
1605	goto out_reject;
1606	}
1607
1608	nhc = nexthop_get_nhc_lookup(nh: fi->nh, fib_flags, flp,
1609	nhsel: &nhsel);
1610	if (nhc)
1611	goto set_result;
1612	goto miss;
1613	}
1614
1615	for (nhsel = 0; nhsel < fib_info_num_path(fi); nhsel++) {
1616	nhc = fib_info_nhc(fi, nhsel);
1617
1618	if (!fib_lookup_good_nhc(nhc, fib_flags, flp))
1619	continue;
1620	set_result:
1621	if (!(fib_flags & FIB_LOOKUP_NOREF))
1622	refcount_inc(r: &fi->fib_clntref);
1623
1624	res->prefix = htonl(n->key);
1625	res->prefixlen = KEYLENGTH - fa->fa_slen;
1626	res->nh_sel = nhsel;
1627	res->nhc = nhc;
1628	res->type = fa->fa_type;
1629	res->scope = fi->fib_scope;
1630	res->fi = fi;
1631	res->table = tb;
1632	res->fa_head = &n->leaf;
1633	#ifdef CONFIG_IP_FIB_TRIE_STATS
1634	this_cpu_inc(stats->semantic_match_passed);
1635	#endif
1636	trace_fib_table_lookup(tb_id: tb->tb_id, flp, nhc, err);
1637
1638	return err;
1639	}
1640	}
1641	miss:
1642	#ifdef CONFIG_IP_FIB_TRIE_STATS
1643	this_cpu_inc(stats->semantic_match_miss);
1644	#endif
1645	goto backtrace;
1646	}
1647	EXPORT_SYMBOL_GPL(fib_table_lookup);
1648
1649	static void fib_remove_alias(struct trie *t, struct key_vector *tp,
1650	struct key_vector *l, struct fib_alias *old)
1651	{
1652	/* record the location of the previous list_info entry */
1653	struct hlist_node **pprev = old->fa_list.pprev;
1654	struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next);
1655
1656	/* remove the fib_alias from the list */
1657	hlist_del_rcu(n: &old->fa_list);
1658
1659	/* if we emptied the list this leaf will be freed and we can sort
1660	* out parent suffix lengths as a part of trie_rebalance
1661	*/
1662	if (hlist_empty(h: &l->leaf)) {
1663	if (tp->slen == l->slen)
1664	node_pull_suffix(tn: tp, slen: tp->pos);
1665	put_child_root(tp, key: l->key, NULL);
1666	node_free(l);
1667	trie_rebalance(t, tn: tp);
1668	return;
1669	}
1670
1671	/* only access fa if it is pointing at the last valid hlist_node */
1672	if (*pprev)
1673	return;
1674
1675	/* update the trie with the latest suffix length */
1676	l->slen = fa->fa_slen;
1677	node_pull_suffix(tn: tp, slen: fa->fa_slen);
1678	}
1679
1680	static void fib_notify_alias_delete(struct net *net, u32 key,
1681	struct hlist_head *fah,
1682	struct fib_alias *fa_to_delete,
1683	struct netlink_ext_ack *extack)
1684	{
1685	struct fib_alias *fa_next, *fa_to_notify;
1686	u32 tb_id = fa_to_delete->tb_id;
1687	u8 slen = fa_to_delete->fa_slen;
1688	enum fib_event_type fib_event;
1689
1690	/* Do not notify if we do not care about the route. */
1691	if (fib_find_alias(fah, slen, 0, 0, tb_id, true) != fa_to_delete)
1692	return;
1693
1694	/* Determine if the route should be replaced by the next route in the
1695	* list.
1696	*/
1697	fa_next = hlist_entry_safe(fa_to_delete->fa_list.next,
1698	struct fib_alias, fa_list);
1699	if (fa_next && fa_next->fa_slen == slen && fa_next->tb_id == tb_id) {
1700	fib_event = FIB_EVENT_ENTRY_REPLACE;
1701	fa_to_notify = fa_next;
1702	} else {
1703	fib_event = FIB_EVENT_ENTRY_DEL;
1704	fa_to_notify = fa_to_delete;
1705	}
1706	call_fib_entry_notifiers(net, fib_event, key, KEYLENGTH - slen,
1707	fa_to_notify, extack);
1708	}
1709
1710	/* Caller must hold RTNL. */
1711	int fib_table_delete(struct net *net, struct fib_table *tb,
1712	struct fib_config *cfg, struct netlink_ext_ack *extack)
1713	{
1714	struct trie *t = (struct trie *) tb->tb_data;
1715	struct fib_alias *fa, *fa_to_delete;
1716	struct key_vector *l, *tp;
1717	u8 plen = cfg->fc_dst_len;
1718	u8 slen = KEYLENGTH - plen;
1719	dscp_t dscp;
1720	u32 key;
1721
1722	key = ntohl(cfg->fc_dst);
1723
1724	if (!fib_valid_key_len(key, plen, extack))
1725	return -EINVAL;
1726
1727	l = fib_find_node(t, tp: &tp, key);
1728	if (!l)
1729	return -ESRCH;
1730
1731	dscp = cfg->fc_dscp;
1732	fa = fib_find_alias(&l->leaf, slen, dscp, 0, tb->tb_id, false);
1733	if (!fa)
1734	return -ESRCH;
1735
1736	pr_debug("Deleting %08x/%d dsfield=0x%02x t=%p\n", key, plen,
1737	inet_dscp_to_dsfield(dscp), t);
1738
1739	fa_to_delete = NULL;
1740	hlist_for_each_entry_from(fa, fa_list) {
1741	struct fib_info *fi = fa->fa_info;
1742
1743	if ((fa->fa_slen != slen) ||
1744	(fa->tb_id != tb->tb_id) ||
1745	(fa->fa_dscp != dscp))
1746	break;
1747
1748	if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
1749	(cfg->fc_scope == RT_SCOPE_NOWHERE ||
1750	fa->fa_info->fib_scope == cfg->fc_scope) &&
1751	(!cfg->fc_prefsrc ||
1752	fi->fib_prefsrc == cfg->fc_prefsrc) &&
1753	(!cfg->fc_protocol ||
1754	fi->fib_protocol == cfg->fc_protocol) &&
1755	fib_nh_match(net, cfg, fi, extack) == 0 &&
1756	fib_metrics_match(cfg, fi)) {
1757	fa_to_delete = fa;
1758	break;
1759	}
1760	}
1761
1762	if (!fa_to_delete)
1763	return -ESRCH;
1764
1765	fib_notify_alias_delete(net, key, fah: &l->leaf, fa_to_delete, extack);
1766	rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id,
1767	&cfg->fc_nlinfo, 0);
1768
1769	if (!plen)
1770	tb->tb_num_default--;
1771
1772	fib_remove_alias(t, tp, l, old: fa_to_delete);
1773
1774	if (fa_to_delete->fa_state & FA_S_ACCESSED)
1775	rt_cache_flush(net: cfg->fc_nlinfo.nl_net);
1776
1777	fib_release_info(fa_to_delete->fa_info);
1778	alias_free_mem_rcu(fa: fa_to_delete);
1779	return 0;
1780	}
1781
1782	/* Scan for the next leaf starting at the provided key value */
1783	static struct key_vector *leaf_walk_rcu(struct key_vector **tn, t_key key)
1784	{
1785	struct key_vector *pn, *n = *tn;
1786	unsigned long cindex;
1787
1788	/* this loop is meant to try and find the key in the trie */
1789	do {
1790	/* record parent and next child index */
1791	pn = n;
1792	cindex = (key > pn->key) ? get_index(key, kv: pn) : 0;
1793
1794	if (cindex >> pn->bits)
1795	break;
1796
1797	/* descend into the next child */
1798	n = get_child_rcu(pn, cindex++);
1799	if (!n)
1800	break;
1801
1802	/* guarantee forward progress on the keys */
1803	if (IS_LEAF(n) && (n->key >= key))
1804	goto found;
1805	} while (IS_TNODE(n));
1806
1807	/* this loop will search for the next leaf with a greater key */
1808	while (!IS_TRIE(pn)) {
1809	/* if we exhausted the parent node we will need to climb */
1810	if (cindex >= (1ul << pn->bits)) {
1811	t_key pkey = pn->key;
1812
1813	pn = node_parent_rcu(pn);
1814	cindex = get_index(key: pkey, kv: pn) + 1;
1815	continue;
1816	}
1817
1818	/* grab the next available node */
1819	n = get_child_rcu(pn, cindex++);
1820	if (!n)
1821	continue;
1822
1823	/* no need to compare keys since we bumped the index */
1824	if (IS_LEAF(n))
1825	goto found;
1826
1827	/* Rescan start scanning in new node */
1828	pn = n;
1829	cindex = 0;
1830	}
1831
1832	*tn = pn;
1833	return NULL; /* Root of trie */
1834	found:
1835	/* if we are at the limit for keys just return NULL for the tnode */
1836	*tn = pn;
1837	return n;
1838	}
1839
1840	static void fib_trie_free(struct fib_table *tb)
1841	{
1842	struct trie *t = (struct trie *)tb->tb_data;
1843	struct key_vector *pn = t->kv;
1844	unsigned long cindex = 1;
1845	struct hlist_node *tmp;
1846	struct fib_alias *fa;
1847
1848	/* walk trie in reverse order and free everything */
1849	for (;;) {
1850	struct key_vector *n;
1851
1852	if (!(cindex--)) {
1853	t_key pkey = pn->key;
1854
1855	if (IS_TRIE(pn))
1856	break;
1857
1858	n = pn;
1859	pn = node_parent(pn);
1860
1861	/* drop emptied tnode */
1862	put_child_root(tp: pn, key: n->key, NULL);
1863	node_free(n);
1864
1865	cindex = get_index(key: pkey, kv: pn);
1866
1867	continue;
1868	}
1869
1870	/* grab the next available node */
1871	n = get_child(pn, cindex);
1872	if (!n)
1873	continue;
1874
1875	if (IS_TNODE(n)) {
1876	/* record pn and cindex for leaf walking */
1877	pn = n;
1878	cindex = 1ul << n->bits;
1879
1880	continue;
1881	}
1882
1883	hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
1884	hlist_del_rcu(n: &fa->fa_list);
1885	alias_free_mem_rcu(fa);
1886	}
1887
1888	put_child_root(tp: pn, key: n->key, NULL);
1889	node_free(n);
1890	}
1891
1892	#ifdef CONFIG_IP_FIB_TRIE_STATS
1893	free_percpu(t->stats);
1894	#endif
1895	kfree(objp: tb);
1896	}
1897
1898	struct fib_table *fib_trie_unmerge(struct fib_table *oldtb)
1899	{
1900	struct trie *ot = (struct trie *)oldtb->tb_data;
1901	struct key_vector *l, *tp = ot->kv;
1902	struct fib_table *local_tb;
1903	struct fib_alias *fa;
1904	struct trie *lt;
1905	t_key key = 0;
1906
1907	if (oldtb->tb_data == oldtb->__data)
1908	return oldtb;
1909
1910	local_tb = fib_trie_table(id: RT_TABLE_LOCAL, NULL);
1911	if (!local_tb)
1912	return NULL;
1913
1914	lt = (struct trie *)local_tb->tb_data;
1915
1916	while ((l = leaf_walk_rcu(tn: &tp, key)) != NULL) {
1917	struct key_vector *local_l = NULL, *local_tp;
1918
1919	hlist_for_each_entry(fa, &l->leaf, fa_list) {
1920	struct fib_alias *new_fa;
1921
1922	if (local_tb->tb_id != fa->tb_id)
1923	continue;
1924
1925	/* clone fa for new local table */
1926	new_fa = kmem_cache_alloc(cachep: fn_alias_kmem, GFP_KERNEL);
1927	if (!new_fa)
1928	goto out;
1929
1930	memcpy(to: new_fa, from: fa, len: sizeof(*fa));
1931
1932	/* insert clone into table */
1933	if (!local_l)
1934	local_l = fib_find_node(t: lt, tp: &local_tp, key: l->key);
1935
1936	if (fib_insert_alias(t: lt, tp: local_tp, l: local_l, new: new_fa,
1937	NULL, key: l->key)) {
1938	kmem_cache_free(s: fn_alias_kmem, objp: new_fa);
1939	goto out;
1940	}
1941	}
1942
1943	/* stop loop if key wrapped back to 0 */
1944	key = l->key + 1;
1945	if (key < l->key)
1946	break;
1947	}
1948
1949	return local_tb;
1950	out:
1951	fib_trie_free(tb: local_tb);
1952
1953	return NULL;
1954	}
1955
1956	/* Caller must hold RTNL */
1957	void fib_table_flush_external(struct fib_table *tb)
1958	{
1959	struct trie *t = (struct trie *)tb->tb_data;
1960	struct key_vector *pn = t->kv;
1961	unsigned long cindex = 1;
1962	struct hlist_node *tmp;
1963	struct fib_alias *fa;
1964
1965	/* walk trie in reverse order */
1966	for (;;) {
1967	unsigned char slen = 0;
1968	struct key_vector *n;
1969
1970	if (!(cindex--)) {
1971	t_key pkey = pn->key;
1972
1973	/* cannot resize the trie vector */
1974	if (IS_TRIE(pn))
1975	break;
1976
1977	/* update the suffix to address pulled leaves */
1978	if (pn->slen > pn->pos)
1979	update_suffix(tn: pn);
1980
1981	/* resize completed node */
1982	pn = resize(t, tn: pn);
1983	cindex = get_index(key: pkey, kv: pn);
1984
1985	continue;
1986	}
1987
1988	/* grab the next available node */
1989	n = get_child(pn, cindex);
1990	if (!n)
1991	continue;
1992
1993	if (IS_TNODE(n)) {
1994	/* record pn and cindex for leaf walking */
1995	pn = n;
1996	cindex = 1ul << n->bits;
1997
1998	continue;
1999	}
2000
2001	hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
2002	/* if alias was cloned to local then we just
2003	* need to remove the local copy from main
2004	*/
2005	if (tb->tb_id != fa->tb_id) {
2006	hlist_del_rcu(n: &fa->fa_list);
2007	alias_free_mem_rcu(fa);
2008	continue;
2009	}
2010
2011	/* record local slen */
2012	slen = fa->fa_slen;
2013	}
2014
2015	/* update leaf slen */
2016	n->slen = slen;
2017
2018	if (hlist_empty(h: &n->leaf)) {
2019	put_child_root(tp: pn, key: n->key, NULL);
2020	node_free(n);
2021	}
2022	}
2023	}
2024
2025	/* Caller must hold RTNL. */
2026	int fib_table_flush(struct net *net, struct fib_table *tb, bool flush_all)
2027	{
2028	struct trie *t = (struct trie *)tb->tb_data;
2029	struct key_vector *pn = t->kv;
2030	unsigned long cindex = 1;
2031	struct hlist_node *tmp;
2032	struct fib_alias *fa;
2033	int found = 0;
2034
2035	/* walk trie in reverse order */
2036	for (;;) {
2037	unsigned char slen = 0;
2038	struct key_vector *n;
2039
2040	if (!(cindex--)) {
2041	t_key pkey = pn->key;
2042
2043	/* cannot resize the trie vector */
2044	if (IS_TRIE(pn))
2045	break;
2046
2047	/* update the suffix to address pulled leaves */
2048	if (pn->slen > pn->pos)
2049	update_suffix(tn: pn);
2050
2051	/* resize completed node */
2052	pn = resize(t, tn: pn);
2053	cindex = get_index(key: pkey, kv: pn);
2054
2055	continue;
2056	}
2057
2058	/* grab the next available node */
2059	n = get_child(pn, cindex);
2060	if (!n)
2061	continue;
2062
2063	if (IS_TNODE(n)) {
2064	/* record pn and cindex for leaf walking */
2065	pn = n;
2066	cindex = 1ul << n->bits;
2067
2068	continue;
2069	}
2070
2071	hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
2072	struct fib_info *fi = fa->fa_info;
2073
2074	if (!fi || tb->tb_id != fa->tb_id ||
2075	(!(fi->fib_flags & RTNH_F_DEAD) &&
2076	!fib_props[fa->fa_type].error)) {
2077	slen = fa->fa_slen;
2078	continue;
2079	}
2080
2081	/* Do not flush error routes if network namespace is
2082	* not being dismantled
2083	*/
2084	if (!flush_all && fib_props[fa->fa_type].error) {
2085	slen = fa->fa_slen;
2086	continue;
2087	}
2088
2089	fib_notify_alias_delete(net, key: n->key, fah: &n->leaf, fa_to_delete: fa,
2090	NULL);
2091	hlist_del_rcu(n: &fa->fa_list);
2092	fib_release_info(fa->fa_info);
2093	alias_free_mem_rcu(fa);
2094	found++;
2095	}
2096
2097	/* update leaf slen */
2098	n->slen = slen;
2099
2100	if (hlist_empty(h: &n->leaf)) {
2101	put_child_root(tp: pn, key: n->key, NULL);
2102	node_free(n);
2103	}
2104	}
2105
2106	pr_debug("trie_flush found=%d\n", found);
2107	return found;
2108	}
2109
2110	/* derived from fib_trie_free */
2111	static void __fib_info_notify_update(struct net *net, struct fib_table *tb,
2112	struct nl_info *info)
2113	{
2114	struct trie *t = (struct trie *)tb->tb_data;
2115	struct key_vector *pn = t->kv;
2116	unsigned long cindex = 1;
2117	struct fib_alias *fa;
2118
2119	for (;;) {
2120	struct key_vector *n;
2121
2122	if (!(cindex--)) {
2123	t_key pkey = pn->key;
2124
2125	if (IS_TRIE(pn))
2126	break;
2127
2128	pn = node_parent(pn);
2129	cindex = get_index(key: pkey, kv: pn);
2130	continue;
2131	}
2132
2133	/* grab the next available node */
2134	n = get_child(pn, cindex);
2135	if (!n)
2136	continue;
2137
2138	if (IS_TNODE(n)) {
2139	/* record pn and cindex for leaf walking */
2140	pn = n;
2141	cindex = 1ul << n->bits;
2142
2143	continue;
2144	}
2145
2146	hlist_for_each_entry(fa, &n->leaf, fa_list) {
2147	struct fib_info *fi = fa->fa_info;
2148
2149	if (!fi || !fi->nh_updated || fa->tb_id != tb->tb_id)
2150	continue;
2151
2152	rtmsg_fib(RTM_NEWROUTE, htonl(n->key), fa,
2153	KEYLENGTH - fa->fa_slen, tb->tb_id,
2154	info, NLM_F_REPLACE);
2155	}
2156	}
2157	}
2158
2159	void fib_info_notify_update(struct net *net, struct nl_info *info)
2160	{
2161	unsigned int h;
2162
2163	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2164	struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2165	struct fib_table *tb;
2166
2167	hlist_for_each_entry_rcu(tb, head, tb_hlist,
2168	lockdep_rtnl_is_held())
2169	__fib_info_notify_update(net, tb, info);
2170	}
2171	}
2172
2173	static int fib_leaf_notify(struct key_vector *l, struct fib_table *tb,
2174	struct notifier_block *nb,
2175	struct netlink_ext_ack *extack)
2176	{
2177	struct fib_alias *fa;
2178	int last_slen = -1;
2179	int err;
2180
2181	hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2182	struct fib_info *fi = fa->fa_info;
2183
2184	if (!fi)
2185	continue;
2186
2187	/* local and main table can share the same trie,
2188	* so don't notify twice for the same entry.
2189	*/
2190	if (tb->tb_id != fa->tb_id)
2191	continue;
2192
2193	if (fa->fa_slen == last_slen)
2194	continue;
2195
2196	last_slen = fa->fa_slen;
2197	err = call_fib_entry_notifier(nb, event_type: FIB_EVENT_ENTRY_REPLACE,
2198	dst: l->key, KEYLENGTH - fa->fa_slen,
2199	fa, extack);
2200	if (err)
2201	return err;
2202	}
2203	return 0;
2204	}
2205
2206	static int fib_table_notify(struct fib_table *tb, struct notifier_block *nb,
2207	struct netlink_ext_ack *extack)
2208	{
2209	struct trie *t = (struct trie *)tb->tb_data;
2210	struct key_vector *l, *tp = t->kv;
2211	t_key key = 0;
2212	int err;
2213
2214	while ((l = leaf_walk_rcu(tn: &tp, key)) != NULL) {
2215	err = fib_leaf_notify(l, tb, nb, extack);
2216	if (err)
2217	return err;
2218
2219	key = l->key + 1;
2220	/* stop in case of wrap around */
2221	if (key < l->key)
2222	break;
2223	}
2224	return 0;
2225	}
2226
2227	int fib_notify(struct net *net, struct notifier_block *nb,
2228	struct netlink_ext_ack *extack)
2229	{
2230	unsigned int h;
2231	int err;
2232
2233	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2234	struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2235	struct fib_table *tb;
2236
2237	hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2238	err = fib_table_notify(tb, nb, extack);
2239	if (err)
2240	return err;
2241	}
2242	}
2243	return 0;
2244	}
2245
2246	static void __trie_free_rcu(struct rcu_head *head)
2247	{
2248	struct fib_table *tb = container_of(head, struct fib_table, rcu);
2249	#ifdef CONFIG_IP_FIB_TRIE_STATS
2250	struct trie *t = (struct trie *)tb->tb_data;
2251
2252	if (tb->tb_data == tb->__data)
2253	free_percpu(t->stats);
2254	#endif /* CONFIG_IP_FIB_TRIE_STATS */
2255	kfree(objp: tb);
2256	}
2257
2258	void fib_free_table(struct fib_table *tb)
2259	{
2260	call_rcu(head: &tb->rcu, func: __trie_free_rcu);
2261	}
2262
2263	static int fn_trie_dump_leaf(struct key_vector *l, struct fib_table *tb,
2264	struct sk_buff *skb, struct netlink_callback *cb,
2265	struct fib_dump_filter *filter)
2266	{
2267	unsigned int flags = NLM_F_MULTI;
2268	__be32 xkey = htonl(l->key);
2269	int i, s_i, i_fa, s_fa, err;
2270	struct fib_alias *fa;
2271
2272	if (filter->filter_set ||
2273	!filter->dump_exceptions || !filter->dump_routes)
2274	flags |= NLM_F_DUMP_FILTERED;
2275
2276	s_i = cb->args[4];
2277	s_fa = cb->args[5];
2278	i = 0;
2279
2280	/* rcu_read_lock is hold by caller */
2281	hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2282	struct fib_info *fi = fa->fa_info;
2283
2284	if (i < s_i)
2285	goto next;
2286
2287	i_fa = 0;
2288
2289	if (tb->tb_id != fa->tb_id)
2290	goto next;
2291
2292	if (filter->filter_set) {
2293	if (filter->rt_type && fa->fa_type != filter->rt_type)
2294	goto next;
2295
2296	if ((filter->protocol &&
2297	fi->fib_protocol != filter->protocol))
2298	goto next;
2299
2300	if (filter->dev &&
2301	!fib_info_nh_uses_dev(fi, dev: filter->dev))
2302	goto next;
2303	}
2304
2305	if (filter->dump_routes) {
2306	if (!s_fa) {
2307	struct fib_rt_info fri;
2308
2309	fri.fi = fi;
2310	fri.tb_id = tb->tb_id;
2311	fri.dst = xkey;
2312	fri.dst_len = KEYLENGTH - fa->fa_slen;
2313	fri.dscp = fa->fa_dscp;
2314	fri.type = fa->fa_type;
2315	fri.offload = READ_ONCE(fa->offload);
2316	fri.trap = READ_ONCE(fa->trap);
2317	fri.offload_failed = READ_ONCE(fa->offload_failed);
2318	err = fib_dump_info(skb,
2319	NETLINK_CB(cb->skb).portid,
2320	seq: cb->nlh->nlmsg_seq,
2321	RTM_NEWROUTE, fri: &fri, flags);
2322	if (err < 0)
2323	goto stop;
2324	}
2325
2326	i_fa++;
2327	}
2328
2329	if (filter->dump_exceptions) {
2330	err = fib_dump_info_fnhe(skb, cb, table_id: tb->tb_id, fi,
2331	fa_index: &i_fa, fa_start: s_fa, flags);
2332	if (err < 0)
2333	goto stop;
2334	}
2335
2336	next:
2337	i++;
2338	}
2339
2340	cb->args[4] = i;
2341	return skb->len;
2342
2343	stop:
2344	cb->args[4] = i;
2345	cb->args[5] = i_fa;
2346	return err;
2347	}
2348
2349	/* rcu_read_lock needs to be hold by caller from readside */
2350	int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
2351	struct netlink_callback *cb, struct fib_dump_filter *filter)
2352	{
2353	struct trie *t = (struct trie *)tb->tb_data;
2354	struct key_vector *l, *tp = t->kv;
2355	/* Dump starting at last key.
2356	* Note: 0.0.0.0/0 (ie default) is first key.
2357	*/
2358	int count = cb->args[2];
2359	t_key key = cb->args[3];
2360
2361	/* First time here, count and key are both always 0. Count > 0
2362	* and key == 0 means the dump has wrapped around and we are done.
2363	*/
2364	if (count && !key)
2365	return skb->len;
2366
2367	while ((l = leaf_walk_rcu(tn: &tp, key)) != NULL) {
2368	int err;
2369
2370	err = fn_trie_dump_leaf(l, tb, skb, cb, filter);
2371	if (err < 0) {
2372	cb->args[3] = key;
2373	cb->args[2] = count;
2374	return err;
2375	}
2376
2377	++count;
2378	key = l->key + 1;
2379
2380	memset(s: &cb->args[4], c: 0,
2381	n: sizeof(cb->args) - 4*sizeof(cb->args[0]));
2382
2383	/* stop loop if key wrapped back to 0 */
2384	if (key < l->key)
2385	break;
2386	}
2387
2388	cb->args[3] = key;
2389	cb->args[2] = count;
2390
2391	return skb->len;
2392	}
2393
2394	void __init fib_trie_init(void)
2395	{
2396	fn_alias_kmem = kmem_cache_create(name: "ip_fib_alias",
2397	size: sizeof(struct fib_alias),
2398	align: 0, SLAB_PANIC | SLAB_ACCOUNT, NULL);
2399
2400	trie_leaf_kmem = kmem_cache_create(name: "ip_fib_trie",
2401	LEAF_SIZE,
2402	align: 0, SLAB_PANIC | SLAB_ACCOUNT, NULL);
2403	}
2404
2405	struct fib_table *fib_trie_table(u32 id, struct fib_table *alias)
2406	{
2407	struct fib_table *tb;
2408	struct trie *t;
2409	size_t sz = sizeof(*tb);
2410
2411	if (!alias)
2412	sz += sizeof(struct trie);
2413
2414	tb = kzalloc(size: sz, GFP_KERNEL);
2415	if (!tb)
2416	return NULL;
2417
2418	tb->tb_id = id;
2419	tb->tb_num_default = 0;
2420	tb->tb_data = (alias ? alias->__data : tb->__data);
2421
2422	if (alias)
2423	return tb;
2424
2425	t = (struct trie *) tb->tb_data;
2426	t->kv[0].pos = KEYLENGTH;
2427	t->kv[0].slen = KEYLENGTH;
2428	#ifdef CONFIG_IP_FIB_TRIE_STATS
2429	t->stats = alloc_percpu(struct trie_use_stats);
2430	if (!t->stats) {
2431	kfree(tb);
2432	tb = NULL;
2433	}
2434	#endif
2435
2436	return tb;
2437	}
2438
2439	#ifdef CONFIG_PROC_FS
2440	/* Depth first Trie walk iterator */
2441	struct fib_trie_iter {
2442	struct seq_net_private p;
2443	struct fib_table *tb;
2444	struct key_vector *tnode;
2445	unsigned int index;
2446	unsigned int depth;
2447	};
2448
2449	static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter)
2450	{
2451	unsigned long cindex = iter->index;
2452	struct key_vector *pn = iter->tnode;
2453	t_key pkey;
2454
2455	pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
2456	iter->tnode, iter->index, iter->depth);
2457
2458	while (!IS_TRIE(pn)) {
2459	while (cindex < child_length(pn)) {
2460	struct key_vector *n = get_child_rcu(pn, cindex++);
2461
2462	if (!n)
2463	continue;
2464
2465	if (IS_LEAF(n)) {
2466	iter->tnode = pn;
2467	iter->index = cindex;
2468	} else {
2469	/* push down one level */
2470	iter->tnode = n;
2471	iter->index = 0;
2472	++iter->depth;
2473	}
2474
2475	return n;
2476	}
2477
2478	/* Current node exhausted, pop back up */
2479	pkey = pn->key;
2480	pn = node_parent_rcu(pn);
2481	cindex = get_index(pkey, pn) + 1;
2482	--iter->depth;
2483	}
2484
2485	/* record root node so further searches know we are done */
2486	iter->tnode = pn;
2487	iter->index = 0;
2488
2489	return NULL;
2490	}
2491
2492	static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter,
2493	struct trie *t)
2494	{
2495	struct key_vector *n, *pn;
2496
2497	if (!t)
2498	return NULL;
2499
2500	pn = t->kv;
2501	n = rcu_dereference(pn->tnode[0]);
2502	if (!n)
2503	return NULL;
2504
2505	if (IS_TNODE(n)) {
2506	iter->tnode = n;
2507	iter->index = 0;
2508	iter->depth = 1;
2509	} else {
2510	iter->tnode = pn;
2511	iter->index = 0;
2512	iter->depth = 0;
2513	}
2514
2515	return n;
2516	}
2517
2518	static void trie_collect_stats(struct trie *t, struct trie_stat *s)
2519	{
2520	struct key_vector *n;
2521	struct fib_trie_iter iter;
2522
2523	memset(s, 0, sizeof(*s));
2524
2525	rcu_read_lock();
2526	for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) {
2527	if (IS_LEAF(n)) {
2528	struct fib_alias *fa;
2529
2530	s->leaves++;
2531	s->totdepth += iter.depth;
2532	if (iter.depth > s->maxdepth)
2533	s->maxdepth = iter.depth;
2534
2535	hlist_for_each_entry_rcu(fa, &n->leaf, fa_list)
2536	++s->prefixes;
2537	} else {
2538	s->tnodes++;
2539	if (n->bits < MAX_STAT_DEPTH)
2540	s->nodesizes[n->bits]++;
2541	s->nullpointers += tn_info(n)->empty_children;
2542	}
2543	}
2544	rcu_read_unlock();
2545	}
2546
2547	/*
2548	* This outputs /proc/net/fib_triestats
2549	*/
2550	static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
2551	{
2552	unsigned int i, max, pointers, bytes, avdepth;
2553
2554	if (stat->leaves)
2555	avdepth = stat->totdepth*100 / stat->leaves;
2556	else
2557	avdepth = 0;
2558
2559	seq_printf(seq, "\tAver depth: %u.%02d\n",
2560	avdepth / 100, avdepth % 100);
2561	seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth);
2562
2563	seq_printf(seq, "\tLeaves: %u\n", stat->leaves);
2564	bytes = LEAF_SIZE * stat->leaves;
2565
2566	seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes);
2567	bytes += sizeof(struct fib_alias) * stat->prefixes;
2568
2569	seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);
2570	bytes += TNODE_SIZE(0) * stat->tnodes;
2571
2572	max = MAX_STAT_DEPTH;
2573	while (max > 0 && stat->nodesizes[max-1] == 0)
2574	max--;
2575
2576	pointers = 0;
2577	for (i = 1; i < max; i++)
2578	if (stat->nodesizes[i] != 0) {
2579	seq_printf(seq, " %u: %u", i, stat->nodesizes[i]);
2580	pointers += (1<<i) * stat->nodesizes[i];
2581	}
2582	seq_putc(seq, '\n');
2583	seq_printf(seq, "\tPointers: %u\n", pointers);
2584
2585	bytes += sizeof(struct key_vector *) * pointers;
2586	seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers);
2587	seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024);
2588	}
2589
2590	#ifdef CONFIG_IP_FIB_TRIE_STATS
2591	static void trie_show_usage(struct seq_file *seq,
2592	const struct trie_use_stats __percpu *stats)
2593	{
2594	struct trie_use_stats s = { 0 };
2595	int cpu;
2596
2597	/* loop through all of the CPUs and gather up the stats */
2598	for_each_possible_cpu(cpu) {
2599	const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu);
2600
2601	s.gets += pcpu->gets;
2602	s.backtrack += pcpu->backtrack;
2603	s.semantic_match_passed += pcpu->semantic_match_passed;
2604	s.semantic_match_miss += pcpu->semantic_match_miss;
2605	s.null_node_hit += pcpu->null_node_hit;
2606	s.resize_node_skipped += pcpu->resize_node_skipped;
2607	}
2608
2609	seq_printf(seq, "\nCounters:\n---------\n");
2610	seq_printf(seq, "gets = %u\n", s.gets);
2611	seq_printf(seq, "backtracks = %u\n", s.backtrack);
2612	seq_printf(seq, "semantic match passed = %u\n",
2613	s.semantic_match_passed);
2614	seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss);
2615	seq_printf(seq, "null node hit= %u\n", s.null_node_hit);
2616	seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped);
2617	}
2618	#endif /* CONFIG_IP_FIB_TRIE_STATS */
2619
2620	static void fib_table_print(struct seq_file *seq, struct fib_table *tb)
2621	{
2622	if (tb->tb_id == RT_TABLE_LOCAL)
2623	seq_puts(seq, "Local:\n");
2624	else if (tb->tb_id == RT_TABLE_MAIN)
2625	seq_puts(seq, "Main:\n");
2626	else
2627	seq_printf(seq, "Id %d:\n", tb->tb_id);
2628	}
2629
2630
2631	static int fib_triestat_seq_show(struct seq_file *seq, void *v)
2632	{
2633	struct net *net = seq->private;
2634	unsigned int h;
2635
2636	seq_printf(seq,
2637	"Basic info: size of leaf:"
2638	" %zd bytes, size of tnode: %zd bytes.\n",
2639	LEAF_SIZE, TNODE_SIZE(0));
2640
2641	rcu_read_lock();
2642	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2643	struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2644	struct fib_table *tb;
2645
2646	hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2647	struct trie *t = (struct trie *) tb->tb_data;
2648	struct trie_stat stat;
2649
2650	if (!t)
2651	continue;
2652
2653	fib_table_print(seq, tb);
2654
2655	trie_collect_stats(t, &stat);
2656	trie_show_stats(seq, &stat);
2657	#ifdef CONFIG_IP_FIB_TRIE_STATS
2658	trie_show_usage(seq, t->stats);
2659	#endif
2660	}
2661	cond_resched_rcu();
2662	}
2663	rcu_read_unlock();
2664
2665	return 0;
2666	}
2667
2668	static struct key_vector *fib_trie_get_idx(struct seq_file *seq, loff_t pos)
2669	{
2670	struct fib_trie_iter *iter = seq->private;
2671	struct net *net = seq_file_net(seq);
2672	loff_t idx = 0;
2673	unsigned int h;
2674
2675	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
2676	struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2677	struct fib_table *tb;
2678
2679	hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2680	struct key_vector *n;
2681
2682	for (n = fib_trie_get_first(iter,
2683	(struct trie *) tb->tb_data);
2684	n; n = fib_trie_get_next(iter))
2685	if (pos == idx++) {
2686	iter->tb = tb;
2687	return n;
2688	}
2689	}
2690	}
2691
2692	return NULL;
2693	}
2694
2695	static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
2696	__acquires(RCU)
2697	{
2698	rcu_read_lock();
2699	return fib_trie_get_idx(seq, *pos);
2700	}
2701
2702	static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2703	{
2704	struct fib_trie_iter *iter = seq->private;
2705	struct net *net = seq_file_net(seq);
2706	struct fib_table *tb = iter->tb;
2707	struct hlist_node *tb_node;
2708	unsigned int h;
2709	struct key_vector *n;
2710
2711	++*pos;
2712	/* next node in same table */
2713	n = fib_trie_get_next(iter);
2714	if (n)
2715	return n;
2716
2717	/* walk rest of this hash chain */
2718	h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);
2719	while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) {
2720	tb = hlist_entry(tb_node, struct fib_table, tb_hlist);
2721	n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2722	if (n)
2723	goto found;
2724	}
2725
2726	/* new hash chain */
2727	while (++h < FIB_TABLE_HASHSZ) {
2728	struct hlist_head *head = &net->ipv4.fib_table_hash[h];
2729	hlist_for_each_entry_rcu(tb, head, tb_hlist) {
2730	n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
2731	if (n)
2732	goto found;
2733	}
2734	}
2735	return NULL;
2736
2737	found:
2738	iter->tb = tb;
2739	return n;
2740	}
2741
2742	static void fib_trie_seq_stop(struct seq_file *seq, void *v)
2743	__releases(RCU)
2744	{
2745	rcu_read_unlock();
2746	}
2747
2748	static void seq_indent(struct seq_file *seq, int n)
2749	{
2750	while (n-- > 0)
2751	seq_puts(seq, " ");
2752	}
2753
2754	static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
2755	{
2756	switch (s) {
2757	case RT_SCOPE_UNIVERSE: return "universe";
2758	case RT_SCOPE_SITE: return "site";
2759	case RT_SCOPE_LINK: return "link";
2760	case RT_SCOPE_HOST: return "host";
2761	case RT_SCOPE_NOWHERE: return "nowhere";
2762	default:
2763	snprintf(buf, len, "scope=%d", s);
2764	return buf;
2765	}
2766	}
2767
2768	static const char *const rtn_type_names[__RTN_MAX] = {
2769	[RTN_UNSPEC] = "UNSPEC",
2770	[RTN_UNICAST] = "UNICAST",
2771	[RTN_LOCAL] = "LOCAL",
2772	[RTN_BROADCAST] = "BROADCAST",
2773	[RTN_ANYCAST] = "ANYCAST",
2774	[RTN_MULTICAST] = "MULTICAST",
2775	[RTN_BLACKHOLE] = "BLACKHOLE",
2776	[RTN_UNREACHABLE] = "UNREACHABLE",
2777	[RTN_PROHIBIT] = "PROHIBIT",
2778	[RTN_THROW] = "THROW",
2779	[RTN_NAT] = "NAT",
2780	[RTN_XRESOLVE] = "XRESOLVE",
2781	};
2782
2783	static inline const char *rtn_type(char *buf, size_t len, unsigned int t)
2784	{
2785	if (t < __RTN_MAX && rtn_type_names[t])
2786	return rtn_type_names[t];
2787	snprintf(buf, len, "type %u", t);
2788	return buf;
2789	}
2790
2791	/* Pretty print the trie */
2792	static int fib_trie_seq_show(struct seq_file *seq, void *v)
2793	{
2794	const struct fib_trie_iter *iter = seq->private;
2795	struct key_vector *n = v;
2796
2797	if (IS_TRIE(node_parent_rcu(n)))
2798	fib_table_print(seq, iter->tb);
2799
2800	if (IS_TNODE(n)) {
2801	__be32 prf = htonl(n->key);
2802
2803	seq_indent(seq, iter->depth-1);
2804	seq_printf(seq, " +-- %pI4/%zu %u %u %u\n",
2805	&prf, KEYLENGTH - n->pos - n->bits, n->bits,
2806	tn_info(n)->full_children,
2807	tn_info(n)->empty_children);
2808	} else {
2809	__be32 val = htonl(n->key);
2810	struct fib_alias *fa;
2811
2812	seq_indent(seq, iter->depth);
2813	seq_printf(seq, " |-- %pI4\n", &val);
2814
2815	hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {
2816	char buf1[32], buf2[32];
2817
2818	seq_indent(seq, iter->depth + 1);
2819	seq_printf(seq, " /%zu %s %s",
2820	KEYLENGTH - fa->fa_slen,
2821	rtn_scope(buf1, sizeof(buf1),
2822	fa->fa_info->fib_scope),
2823	rtn_type(buf2, sizeof(buf2),
2824	fa->fa_type));
2825	if (fa->fa_dscp)
2826	seq_printf(seq, " tos=%d",
2827	inet_dscp_to_dsfield(fa->fa_dscp));
2828	seq_putc(seq, '\n');
2829	}
2830	}
2831
2832	return 0;
2833	}
2834
2835	static const struct seq_operations fib_trie_seq_ops = {
2836	.start = fib_trie_seq_start,
2837	.next = fib_trie_seq_next,
2838	.stop = fib_trie_seq_stop,
2839	.show = fib_trie_seq_show,
2840	};
2841
2842	struct fib_route_iter {
2843	struct seq_net_private p;
2844	struct fib_table *main_tb;
2845	struct key_vector *tnode;
2846	loff_t pos;
2847	t_key key;
2848	};
2849
2850	static struct key_vector *fib_route_get_idx(struct fib_route_iter *iter,
2851	loff_t pos)
2852	{
2853	struct key_vector *l, **tp = &iter->tnode;
2854	t_key key;
2855
2856	/* use cached location of previously found key */
2857	if (iter->pos > 0 && pos >= iter->pos) {
2858	key = iter->key;
2859	} else {
2860	iter->pos = 1;
2861	key = 0;
2862	}
2863
2864	pos -= iter->pos;
2865
2866	while ((l = leaf_walk_rcu(tp, key)) && (pos-- > 0)) {
2867	key = l->key + 1;
2868	iter->pos++;
2869	l = NULL;
2870
2871	/* handle unlikely case of a key wrap */
2872	if (!key)
2873	break;
2874	}
2875
2876	if (l)
2877	iter->key = l->key; /* remember it */
2878	else
2879	iter->pos = 0; /* forget it */
2880
2881	return l;
2882	}
2883
2884	static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos)
2885	__acquires(RCU)
2886	{
2887	struct fib_route_iter *iter = seq->private;
2888	struct fib_table *tb;
2889	struct trie *t;
2890
2891	rcu_read_lock();
2892
2893	tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
2894	if (!tb)
2895	return NULL;
2896
2897	iter->main_tb = tb;
2898	t = (struct trie *)tb->tb_data;
2899	iter->tnode = t->kv;
2900
2901	if (*pos != 0)
2902	return fib_route_get_idx(iter, *pos);
2903
2904	iter->pos = 0;
2905	iter->key = KEY_MAX;
2906
2907	return SEQ_START_TOKEN;
2908	}
2909
2910	static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2911	{
2912	struct fib_route_iter *iter = seq->private;
2913	struct key_vector *l = NULL;
2914	t_key key = iter->key + 1;
2915
2916	++*pos;
2917
2918	/* only allow key of 0 for start of sequence */
2919	if ((v == SEQ_START_TOKEN) || key)
2920	l = leaf_walk_rcu(&iter->tnode, key);
2921
2922	if (l) {
2923	iter->key = l->key;
2924	iter->pos++;
2925	} else {
2926	iter->pos = 0;
2927	}
2928
2929	return l;
2930	}
2931
2932	static void fib_route_seq_stop(struct seq_file *seq, void *v)
2933	__releases(RCU)
2934	{
2935	rcu_read_unlock();
2936	}
2937
2938	static unsigned int fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
2939	{
2940	unsigned int flags = 0;
2941
2942	if (type == RTN_UNREACHABLE || type == RTN_PROHIBIT)
2943	flags = RTF_REJECT;
2944	if (fi) {
2945	const struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
2946
2947	if (nhc->nhc_gw.ipv4)
2948	flags |= RTF_GATEWAY;
2949	}
2950	if (mask == htonl(0xFFFFFFFF))
2951	flags |= RTF_HOST;
2952	flags |= RTF_UP;
2953	return flags;
2954	}
2955
2956	/*
2957	* This outputs /proc/net/route.
2958	* The format of the file is not supposed to be changed
2959	* and needs to be same as fib_hash output to avoid breaking
2960	* legacy utilities
2961	*/
2962	static int fib_route_seq_show(struct seq_file *seq, void *v)
2963	{
2964	struct fib_route_iter *iter = seq->private;
2965	struct fib_table *tb = iter->main_tb;
2966	struct fib_alias *fa;
2967	struct key_vector *l = v;
2968	__be32 prefix;
2969
2970	if (v == SEQ_START_TOKEN) {
2971	seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
2972	"\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
2973	"\tWindow\tIRTT");
2974	return 0;
2975	}
2976
2977	prefix = htonl(l->key);
2978
2979	hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
2980	struct fib_info *fi = fa->fa_info;
2981	__be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen);
2982	unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);
2983
2984	if ((fa->fa_type == RTN_BROADCAST) ||
2985	(fa->fa_type == RTN_MULTICAST))
2986	continue;
2987
2988	if (fa->tb_id != tb->tb_id)
2989	continue;
2990
2991	seq_setwidth(seq, 127);
2992
2993	if (fi) {
2994	struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
2995	__be32 gw = 0;
2996
2997	if (nhc->nhc_gw_family == AF_INET)
2998	gw = nhc->nhc_gw.ipv4;
2999
3000	seq_printf(seq,
3001	"%s\t%08X\t%08X\t%04X\t%d\t%u\t"
3002	"%d\t%08X\t%d\t%u\t%u",
3003	nhc->nhc_dev ? nhc->nhc_dev->name : "*",
3004	prefix, gw, flags, 0, 0,
3005	fi->fib_priority,
3006	mask,
3007	(fi->fib_advmss ?
3008	fi->fib_advmss + 40 : 0),
3009	fi->fib_window,
3010	fi->fib_rtt >> 3);
3011	} else {
3012	seq_printf(seq,
3013	"*\t%08X\t%08X\t%04X\t%d\t%u\t"
3014	"%d\t%08X\t%d\t%u\t%u",
3015	prefix, 0, flags, 0, 0, 0,
3016	mask, 0, 0, 0);
3017	}
3018	seq_pad(seq, '\n');
3019	}
3020
3021	return 0;
3022	}
3023
3024	static const struct seq_operations fib_route_seq_ops = {
3025	.start = fib_route_seq_start,
3026	.next = fib_route_seq_next,
3027	.stop = fib_route_seq_stop,
3028	.show = fib_route_seq_show,
3029	};
3030
3031	int __net_init fib_proc_init(struct net *net)
3032	{
3033	if (!proc_create_net("fib_trie", 0444, net->proc_net, &fib_trie_seq_ops,
3034	sizeof(struct fib_trie_iter)))
3035	goto out1;
3036
3037	if (!proc_create_net_single("fib_triestat", 0444, net->proc_net,
3038	fib_triestat_seq_show, NULL))
3039	goto out2;
3040
3041	if (!proc_create_net("route", 0444, net->proc_net, &fib_route_seq_ops,
3042	sizeof(struct fib_route_iter)))
3043	goto out3;
3044
3045	return 0;
3046
3047	out3:
3048	remove_proc_entry("fib_triestat", net->proc_net);
3049	out2:
3050	remove_proc_entry("fib_trie", net->proc_net);
3051	out1:
3052	return -ENOMEM;
3053	}
3054
3055	void __net_exit fib_proc_exit(struct net *net)
3056	{
3057	remove_proc_entry("fib_trie", net->proc_net);
3058	remove_proc_entry("fib_triestat", net->proc_net);
3059	remove_proc_entry("route", net->proc_net);
3060	}
3061
3062	#endif /* CONFIG_PROC_FS */
3063