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
76	static 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.info);
91	}
92
93	static 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.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
115	typedef 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
121	struct 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
134	struct 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
147	struct 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
157	struct 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
167	struct 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
174	static struct key_vector *resize(struct trie *t, struct key_vector *tn);
175	static 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	*/
182	unsigned int sysctl_fib_sync_mem = 512 * 1024;
183	unsigned int sysctl_fib_sync_mem_min = 64 * 1024;
184	unsigned int sysctl_fib_sync_mem_max = 64 * 1024 * 1024;
185
186	static struct kmem_cache *fn_alias_kmem __ro_after_init;
187	static struct kmem_cache *trie_leaf_kmem __ro_after_init;
188
189	static 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 */
203	static 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	*/
214	static 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
221	static 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
290	static const int halve_threshold = 25;
291	static const int inflate_threshold = 50;
292	static const int halve_threshold_root = 15;
293	static const int inflate_threshold_root = 30;
294
295	static 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(s: fn_alias_kmem, objp: fa);
299	}
300
301	static inline void alias_free_mem_rcu(struct fib_alias *fa)
302	{
303	call_rcu(head: &fa->rcu, func: __alias_free_mem);
304	}
305
306	#define TNODE_VMALLOC_MAX \
307	ilog2((SIZE_MAX - TNODE_SIZE(0)) / sizeof(struct key_vector *))
308
309	static 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(s: trie_leaf_kmem, objp: n);
315	else
316	kvfree(addr: n);
317	}
318
319	#define node_free(n) call_rcu(&tn_info(n)->rcu, __node_free_rcu)
320
321	static 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
338	static inline void empty_child_inc(struct key_vector *n)
339	{
340	tn_info(kv: n)->empty_children++;
341
342	if (!tn_info(kv: n)->empty_children)
343	tn_info(kv: n)->full_children++;
344	}
345
346	static inline void empty_child_dec(struct key_vector *n)
347	{
348	if (!tn_info(kv: n)->empty_children)
349	tn_info(kv: n)->full_children--;
350
351	tn_info(kv: n)->empty_children--;
352	}
353
354	static 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(cachep: 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(n: &fa->fa_list, h: &l->leaf);
373
374	return l;
375	}
376
377	static 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	*/
410	static 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	*/
418	static 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(n: tn);
429	if (n && !chi)
430	empty_child_dec(n: tn);
431
432	/* update fullChildren */
433	wasfull = tnode_full(tn, n: chi);
434	isfull = tnode_full(tn, n);
435
436	if (wasfull && !isfull)
437	tn_info(kv: tn)->full_children--;
438	else if (!wasfull && isfull)
439	tn_info(kv: 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
447	static 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(tn: inode);
464	else
465	node_set_parent(n: inode, tp: tn);
466	}
467	}
468
469	static 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(tn: tp, i: get_index(key, kv: tp), n);
476	}
477
478	static inline void tnode_free_init(struct key_vector *tn)
479	{
480	tn_info(kv: tn)->rcu.next = NULL;
481	}
482
483	static inline void tnode_free_append(struct key_vector *tn,
484	struct key_vector *n)
485	{
486	tn_info(kv: n)->rcu.next = tn_info(kv: tn)->rcu.next;
487	tn_info(kv: tn)->rcu.next = &tn_info(kv: n)->rcu;
488	}
489
490	static void tnode_free(struct key_vector *tn)
491	{
492	struct callback_head *head = &tn_info(kv: 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_net();
505	}
506	}
507
508	static 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, key: tn->key, n: 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(tn: 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, n: inode))
531	tn = resize(t, tn: inode);
532	}
533
534	return tp;
535	}
536
537	static 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(key: oldtnode->key, pos: oldtnode->pos - 1, bits: oldtnode->bits + 1);
547	if (!tn)
548	goto notnode;
549
550	/* prepare oldtnode to be freed */
551	tnode_free_init(tn: 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(tn: 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(tn: oldtnode, n: inode)) {
569	put_child(tn, i: get_index(key: inode->key, kv: tn), n: inode);
570	continue;
571	}
572
573	/* drop the node in the old tnode free list */
574	tnode_free_append(tn: oldtnode, n: inode);
575
576	/* An internal node with two children */
577	if (inode->bits == 1) {
578	put_child(tn, i: 2 * i + 1, get_child(inode, 1));
579	put_child(tn, i: 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(key: inode->key | m, pos: inode->pos, bits: inode->bits - 1);
598	if (!node1)
599	goto nomem;
600	node0 = tnode_new(key: inode->key, pos: inode->pos, bits: inode->bits - 1);
601
602	tnode_free_append(tn, n: node1);
603	if (!node0)
604	goto nomem;
605	tnode_free_append(tn, n: node0);
606
607	/* populate child pointers in new nodes */
608	for (k = child_length(tn: inode), j = k / 2; j;) {
609	put_child(tn: node1, i: --j, get_child(inode, --k));
610	put_child(tn: node0, i: j, get_child(inode, j));
611	put_child(tn: node1, i: --j, get_child(inode, --k));
612	put_child(tn: node0, i: 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, i: 2 * i + 1, n: node1);
621	put_child(tn, i: 2 * i, n: node0);
622	}
623
624	/* setup the parent pointers into and out of this node */
625	return replace(t, oldtnode, tn);
626	nomem:
627	/* all pointers should be clean so we are done */
628	tnode_free(tn);
629	notnode:
630	return NULL;
631	}
632
633	static 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(key: oldtnode->key, pos: oldtnode->pos + 1, bits: oldtnode->bits - 1);
642	if (!tn)
643	goto notnode;
644
645	/* prepare oldtnode to be freed */
646	tnode_free_init(tn: 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(tn: 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: i / 2, n: node1 ? : node0);
661	continue;
662	}
663
664	/* Two nonempty children */
665	inode = tnode_new(key: node0->key, pos: oldtnode->pos, bits: 1);
666	if (!inode)
667	goto nomem;
668	tnode_free_append(tn, n: inode);
669
670	/* initialize pointers out of node */
671	put_child(tn: inode, i: 1, n: node1);
672	put_child(tn: inode, i: 0, n: node0);
673	NODE_INIT_PARENT(inode, tn);
674
675	/* link parent to node */
676	put_child(tn, i: i / 2, n: inode);
677	}
678
679	/* setup the parent pointers into and out of this node */
680	return replace(t, oldtnode, tn);
681	nomem:
682	/* all pointers should be clean so we are done */
683	tnode_free(tn);
684	notnode:
685	return NULL;
686	}
687
688	static 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(tn: oldtnode); !n && i;)
696	n = get_child(oldtnode, --i);
697
698	/* compress one level */
699	tp = node_parent(oldtnode);
700	put_child_root(tp, key: oldtnode->key, n);
701	node_set_parent(n, tp);
702
703	/* drop dead node */
704	node_free(oldtnode);
705
706	return tp;
707	}
708
709	static 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	*/
804	static 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(kv: tn)->empty_children;
812	used += tn_info(kv: 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
819	static 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(kv: 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
833	static inline bool should_collapse(struct key_vector *tn)
834	{
835	unsigned long used = child_length(tn);
836
837	used -= tn_info(kv: tn)->empty_children;
838
839	/* account for bits == KEYLENGTH case */
840	if ((tn->bits == KEYLENGTH) && tn_info(kv: 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
848	static 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(key: tn->key, kv: 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, oldtnode: 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, oldtnode: 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, oldtnode: tn);
908
909	/* update parent in case halve failed */
910	return node_parent(tn);
911	}
912
913	static 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
927	static 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 */
936	static 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	*/
983	static 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(dscp: 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
1016	static struct fib_alias *
1017	fib_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, id: fri->tb_id);
1026	if (!tb)
1027	return NULL;
1028
1029	t = (struct trie *)tb->tb_data;
1030	l = fib_find_node(t, tp: &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
1044	void 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(payload: fib_nlmsg_size(fi: fa_match->fa_info), GFP_ATOMIC);
1081	if (!skb) {
1082	err = -ENOBUFS;
1083	goto errout;
1084	}
1085
1086	err = fib_dump_info(skb, pid: 0, seq: 0, RTM_NEWROUTE, fri, flags: 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, pid: 0, RTNLGRP_IPV4_ROUTE, NULL, GFP_ATOMIC);
1095	goto out;
1096
1097	errout:
1098	rtnl_set_sk_err(net, RTNLGRP_IPV4_ROUTE, error: err);
1099	out:
1100	rcu_read_unlock();
1101	}
1102	EXPORT_SYMBOL_GPL(fib_alias_hw_flags_set);
1103
1104	static void trie_rebalance(struct trie *t, struct key_vector *tn)
1105	{
1106	while (!IS_TRIE(tn))
1107	tn = resize(t, tn);
1108	}
1109
1110	static 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, fa: 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, pos: __fls(word: key ^ n->key), bits: 1);
1132	if (!tn)
1133	goto notnode;
1134
1135	/* initialize routes out of node */
1136	NODE_INIT_PARENT(tn, tp);
1137	put_child(tn, i: get_index(key, kv: tn) ^ 1, n);
1138
1139	/* start adding routes into the node */
1140	put_child_root(tp, key, n: tn);
1141	node_set_parent(n, tp: 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(tn: tp, slen: new->fa_slen);
1149	NODE_INIT_PARENT(l, tp);
1150	put_child_root(tp, key, n: l);
1151	trie_rebalance(t, tn: tp);
1152
1153	return 0;
1154	notnode:
1155	node_free(l);
1156	noleaf:
1157	return -ENOMEM;
1158	}
1159
1160	static 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(n: &new->fa_list, next: &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(n: &new->fa_list, prev: &fa->fa_list);
1183	else
1184	hlist_add_head_rcu(n: &new->fa_list, h: &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(tn: tp, slen: new->fa_slen);
1191	}
1192
1193	return 0;
1194	}
1195
1196	static 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
1212	static 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. */
1216	int 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(ptr: fi)) {
1239	err = PTR_ERR(ptr: fi);
1240	goto err;
1241	}
1242
1243	dscp = cfg->fc_dscp;
1244	l = fib_find_node(t, tp: &tp, key);
1245	fa = l ? fib_find_alias(fah: &l->leaf, slen, dscp, prio: fi->fib_priority,
1246	tb_id: tb->tb_id, find_first: 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(cachep: 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(old: &fa->fa_list, new: &new_fa->fa_list);
1318
1319	if (fib_find_alias(fah: &l->leaf, slen: fa->fa_slen, dscp: 0, prio: 0,
1320	tb_id: tb->tb_id, find_first: 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, event_type: fib_event,
1325	dst: key, dst_len: plen,
1326	fa: new_fa, extack);
1327	if (err) {
1328	hlist_replace_rcu(old: &new_fa->fa_list,
1329	new: &fa->fa_list);
1330	goto out_free_new_fa;
1331	}
1332	}
1333
1334	rtmsg_fib(RTM_NEWROUTE, htonl(key), fa: new_fa, dst_len: plen,
1335	tb_id: tb->tb_id, info: &cfg->fc_nlinfo, nlm_flags: 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(net: 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(cachep: 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: 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: &tp, key);
1385	if (WARN_ON_ONCE(!l)) {
1386	err = -ENOENT;
1387	goto out_free_new_fa;
1388	}
1389
1390	if (fib_find_alias(fah: &l->leaf, slen: new_fa->fa_slen, dscp: 0, prio: 0, tb_id: tb->tb_id, find_first: 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, event_type: fib_event, dst: key, dst_len: plen,
1396	fa: 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(net: cfg->fc_nlinfo.nl_net);
1405	rtmsg_fib(RTM_NEWROUTE, htonl(key), fa: new_fa, dst_len: plen, tb_id: new_fa->tb_id,
1406	info: &cfg->fc_nlinfo, nlm_flags: nlflags);
1407	succeeded:
1408	return 0;
1409
1410	out_remove_new_fa:
1411	fib_remove_alias(t, tp, l, old: new_fa);
1412	out_free_new_fa:
1413	kmem_cache_free(s: fn_alias_kmem, objp: new_fa);
1414	out:
1415	fib_release_info(fi);
1416	err:
1417	return err;
1418	}
1419
1420	static 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
1427	bool 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(dev: 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 */
1445	int 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_id: tb->tb_id, flp, NULL, err: -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) {
1531	backtrace:
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_id: tb->tb_id, flp,
1550	NULL, err: -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(key: pkey, kv: 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
1569	found:
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(dscp: 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)) {
1594	out_reject:
1595	#ifdef CONFIG_IP_FIB_TRIE_STATS
1596	this_cpu_inc(stats->semantic_match_passed);
1597	#endif
1598	trace_fib_table_lookup(tb_id: 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(nh: fi->nh)) {
1606	err = fib_props[RTN_BLACKHOLE].error;
1607	goto out_reject;
1608	}
1609
1610	nhc = nexthop_get_nhc_lookup(nh: fi->nh, fib_flags, flp,
1611	nhsel: &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;
1622	set_result:
1623	if (!(fib_flags & FIB_LOOKUP_NOREF))
1624	refcount_inc(r: &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_id: tb->tb_id, flp, nhc, err);
1639
1640	return err;
1641	}
1642	}
1643	miss:
1644	#ifdef CONFIG_IP_FIB_TRIE_STATS
1645	this_cpu_inc(stats->semantic_match_miss);
1646	#endif
1647	goto backtrace;
1648	}
1649	EXPORT_SYMBOL_GPL(fib_table_lookup);
1650
1651	static 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(n: &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(h: &l->leaf)) {
1665	if (tp->slen == l->slen)
1666	node_pull_suffix(tn: tp, slen: tp->pos);
1667	put_child_root(tp, key: l->key, NULL);
1668	node_free(l);
1669	trie_rebalance(t, tn: 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(tn: tp, slen: fa->fa_slen);
1680	}
1681
1682	static 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, dscp: 0, prio: 0, tb_id, find_first: 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, event_type: fib_event, dst: key, KEYLENGTH - slen,
1709	fa: fa_to_notify, extack);
1710	}
1711
1712	/* Caller must hold RTNL. */
1713	int 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: &tp, key);
1730	if (!l)
1731	return -ESRCH;
1732
1733	dscp = cfg->fc_dscp;
1734	fa = fib_find_alias(fah: &l->leaf, slen, dscp, prio: 0, tb_id: tb->tb_id, find_first: 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, fah: &l->leaf, fa_to_delete, extack);
1768	rtmsg_fib(RTM_DELROUTE, htonl(key), fa: fa_to_delete, dst_len: plen, tb_id: tb->tb_id,
1769	info: &cfg->fc_nlinfo, nlm_flags: 0);
1770
1771	if (!plen)
1772	tb->tb_num_default--;
1773
1774	fib_remove_alias(t, tp, l, old: fa_to_delete);
1775
1776	if (fa_to_delete->fa_state & FA_S_ACCESSED)
1777	rt_cache_flush(net: cfg->fc_nlinfo.nl_net);
1778
1779	fib_release_info(fa_to_delete->fa_info);
1780	alias_free_mem_rcu(fa: fa_to_delete);
1781	return 0;
1782	}
1783
1784	/* Scan for the next leaf starting at the provided key value */
1785	static 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, kv: 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(key: pkey, kv: 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 */
1836	found:
1837	/* if we are at the limit for keys just return NULL for the tnode */
1838	*tn = pn;
1839	return n;
1840	}
1841
1842	static 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(tp: pn, key: n->key, NULL);
1865	node_free(n);
1866
1867	cindex = get_index(key: pkey, kv: 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(n: &fa->fa_list);
1887	alias_free_mem_rcu(fa);
1888	}
1889
1890	put_child_root(tp: pn, key: n->key, NULL);
1891	node_free(n);
1892	}
1893
1894	#ifdef CONFIG_IP_FIB_TRIE_STATS
1895	free_percpu(pdata: t->stats);
1896	#endif
1897	kfree(objp: tb);
1898	}
1899
1900	struct 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(id: 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(tn: &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(cachep: 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(t: lt, tp: &local_tp, key: l->key);
1937
1938	if (fib_insert_alias(t: lt, tp: local_tp, l: local_l, new: new_fa,
1939	NULL, key: l->key)) {
1940	kmem_cache_free(s: fn_alias_kmem, objp: 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;
1952	out:
1953	fib_trie_free(tb: local_tb);
1954
1955	return NULL;
1956	}
1957
1958	/* Caller must hold RTNL */
1959	void 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(tn: pn);
1982
1983	/* resize completed node */
1984	pn = resize(t, tn: pn);
1985	cindex = get_index(key: pkey, kv: 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(n: &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(h: &n->leaf)) {
2021	put_child_root(tp: pn, key: n->key, NULL);
2022	node_free(n);
2023	}
2024	}
2025	}
2026
2027	/* Caller must hold RTNL. */
2028	int 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(tn: pn);
2053
2054	/* resize completed node */
2055	pn = resize(t, tn: pn);
2056	cindex = get_index(key: pkey, kv: 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, key: n->key, fah: &n->leaf, fa_to_delete: fa,
2093	NULL);
2094	if (fi->pfsrc_removed)
2095	rtmsg_fib(RTM_DELROUTE, htonl(n->key), fa,
2096	KEYLENGTH - fa->fa_slen, tb_id: tb->tb_id, info: &info, nlm_flags: 0);
2097	hlist_del_rcu(n: &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(h: &n->leaf)) {
2107	put_child_root(tp: pn, key: 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 */
2117	static 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(key: pkey, kv: 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_id: tb->tb_id,
2160	info, NLM_F_REPLACE);
2161	}
2162	}
2163	}
2164
2165	void 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
2179	static 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, event_type: FIB_EVENT_ENTRY_REPLACE,
2204	dst: l->key, KEYLENGTH - fa->fa_slen,
2205	fa, extack);
2206	if (err)
2207	return err;
2208	}
2209	return 0;
2210	}
2211
2212	static 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(tn: &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
2233	int 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
2252	static 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(pdata: t->stats);
2260	#endif /* CONFIG_IP_FIB_TRIE_STATS */
2261	kfree(objp: tb);
2262	}
2263
2264	void fib_free_table(struct fib_table *tb)
2265	{
2266	call_rcu(head: &tb->rcu, func: __trie_free_rcu);
2267	}
2268
2269	static 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, dev: 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	seq: cb->nlh->nlmsg_seq,
2327	RTM_NEWROUTE, fri: &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, table_id: tb->tb_id, fi,
2337	fa_index: &i_fa, fa_start: s_fa, flags);
2338	if (err < 0)
2339	goto stop;
2340	}
2341
2342	next:
2343	i++;
2344	}
2345
2346	cb->args[4] = i;
2347	return skb->len;
2348
2349	stop:
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 */
2356	int 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 0;
2372
2373	while ((l = leaf_walk_rcu(tn: &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 0;
2398	}
2399
2400	void __init fib_trie_init(void)
2401	{
2402	fn_alias_kmem = kmem_cache_create(name: "ip_fib_alias",
2403	size: sizeof(struct fib_alias),
2404	align: 0, SLAB_PANIC | SLAB_ACCOUNT, NULL);
2405
2406	trie_leaf_kmem = kmem_cache_create(name: "ip_fib_trie",
2407	LEAF_SIZE,
2408	align: 0, SLAB_PANIC | SLAB_ACCOUNT, NULL);
2409	}
2410
2411	struct 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(size: 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(objp: tb);
2438	tb = NULL;
2439	}
2440	#endif
2441
2442	return tb;
2443	}
2444
2445	#ifdef CONFIG_PROC_FS
2446	/* Depth first Trie walk iterator */
2447	struct 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
2455	static 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(tn: 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(key: pkey, kv: 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
2498	static 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
2524	static 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: &iter, t); n; n = fib_trie_get_next(iter: &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(kv: n)->empty_children;
2548	}
2549	}
2550	rcu_read_unlock();
2551	}
2552
2553	/*
2554	* This outputs /proc/net/fib_triestats
2555	*/
2556	static 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(m: seq, fmt: "\tAver depth: %u.%02d\n",
2566	avdepth / 100, avdepth % 100);
2567	seq_printf(m: seq, fmt: "\tMax depth: %u\n", stat->maxdepth);
2568
2569	seq_printf(m: seq, fmt: "\tLeaves: %u\n", stat->leaves);
2570	bytes = LEAF_SIZE * stat->leaves;
2571
2572	seq_printf(m: seq, fmt: "\tPrefixes: %u\n", stat->prefixes);
2573	bytes += sizeof(struct fib_alias) * stat->prefixes;
2574
2575	seq_printf(m: seq, fmt: "\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(m: seq, fmt: " %u: %u", i, stat->nodesizes[i]);
2586	pointers += (1<<i) * stat->nodesizes[i];
2587	}
2588	seq_putc(m: seq, c: '\n');
2589	seq_printf(m: seq, fmt: "\tPointers: %u\n", pointers);
2590
2591	bytes += sizeof(struct key_vector *) * pointers;
2592	seq_printf(m: seq, fmt: "Null ptrs: %u\n", stat->nullpointers);
2593	seq_printf(m: seq, fmt: "Total size: %u kB\n", (bytes + 1023) / 1024);
2594	}
2595
2596	#ifdef CONFIG_IP_FIB_TRIE_STATS
2597	static 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(m: seq, fmt: "\nCounters:\n---------\n");
2616	seq_printf(m: seq, fmt: "gets = %u\n", s.gets);
2617	seq_printf(m: seq, fmt: "backtracks = %u\n", s.backtrack);
2618	seq_printf(m: seq, fmt: "semantic match passed = %u\n",
2619	s.semantic_match_passed);
2620	seq_printf(m: seq, fmt: "semantic match miss = %u\n", s.semantic_match_miss);
2621	seq_printf(m: seq, fmt: "null node hit= %u\n", s.null_node_hit);
2622	seq_printf(m: seq, fmt: "skipped node resize = %u\n\n", s.resize_node_skipped);
2623	}
2624	#endif /* CONFIG_IP_FIB_TRIE_STATS */
2625
2626	static void fib_table_print(struct seq_file *seq, struct fib_table *tb)
2627	{
2628	if (tb->tb_id == RT_TABLE_LOCAL)
2629	seq_puts(m: seq, s: "Local:\n");
2630	else if (tb->tb_id == RT_TABLE_MAIN)
2631	seq_puts(m: seq, s: "Main:\n");
2632	else
2633	seq_printf(m: seq, fmt: "Id %d:\n", tb->tb_id);
2634	}
2635
2636
2637	static 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(m: seq,
2643	fmt: "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, s: &stat);
2662	trie_show_stats(seq, stat: &stat);
2663	#ifdef CONFIG_IP_FIB_TRIE_STATS
2664	trie_show_usage(seq, stats: t->stats);
2665	#endif
2666	}
2667	cond_resched_rcu();
2668	}
2669	rcu_read_unlock();
2670
2671	return 0;
2672	}
2673
2674	static 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	t: (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
2701	static 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: *pos);
2706	}
2707
2708	static 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, t: (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, t: (struct trie *) tb->tb_data);
2737	if (n)
2738	goto found;
2739	}
2740	}
2741	return NULL;
2742
2743	found:
2744	iter->tb = tb;
2745	return n;
2746	}
2747
2748	static void fib_trie_seq_stop(struct seq_file *seq, void *v)
2749	__releases(RCU)
2750	{
2751	rcu_read_unlock();
2752	}
2753
2754	static void seq_indent(struct seq_file *seq, int n)
2755	{
2756	while (n-- > 0)
2757	seq_puts(m: seq, s: " ");
2758	}
2759
2760	static 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, size: len, fmt: "scope=%d", s);
2770	return buf;
2771	}
2772	}
2773
2774	static 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
2789	static 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, size: len, fmt: "type %u", t);
2794	return buf;
2795	}
2796
2797	/* Pretty print the trie */
2798	static 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, tb: iter->tb);
2805
2806	if (IS_TNODE(n)) {
2807	__be32 prf = htonl(n->key);
2808
2809	seq_indent(seq, n: iter->depth-1);
2810	seq_printf(m: seq, fmt: " +-- %pI4/%zu %u %u %u\n",
2811	&prf, KEYLENGTH - n->pos - n->bits, n->bits,
2812	tn_info(kv: n)->full_children,
2813	tn_info(kv: n)->empty_children);
2814	} else {
2815	__be32 val = htonl(n->key);
2816	struct fib_alias *fa;
2817
2818	seq_indent(seq, n: iter->depth);
2819	seq_printf(m: seq, fmt: " |-- %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, n: iter->depth + 1);
2825	seq_printf(m: seq, fmt: " /%zu %s %s",
2826	KEYLENGTH - fa->fa_slen,
2827	rtn_scope(buf: buf1, len: sizeof(buf1),
2828	s: fa->fa_info->fib_scope),
2829	rtn_type(buf: buf2, len: sizeof(buf2),
2830	t: fa->fa_type));
2831	if (fa->fa_dscp)
2832	seq_printf(m: seq, fmt: " tos=%d",
2833	inet_dscp_to_dsfield(dscp: fa->fa_dscp));
2834	seq_putc(m: seq, c: '\n');
2835	}
2836	}
2837
2838	return 0;
2839	}
2840
2841	static 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
2848	struct 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
2856	static 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(tn: 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
2890	static 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(net: seq_file_net(seq), id: 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: *pos);
2909
2910	iter->pos = 0;
2911	iter->key = KEY_MAX;
2912
2913	return SEQ_START_TOKEN;
2914	}
2915
2916	static 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(tn: &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
2938	static void fib_route_seq_stop(struct seq_file *seq, void *v)
2939	__releases(RCU)
2940	{
2941	rcu_read_unlock();
2942	}
2943
2944	static 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, nhsel: 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	*/
2968	static 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(m: seq, fmt: "%-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(type: 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(m: seq, size: 127);
2998
2999	if (fi) {
3000	struct fib_nh_common *nhc = fib_info_nhc(fi, nhsel: 0);
3001	__be32 gw = 0;
3002
3003	if (nhc->nhc_gw_family == AF_INET)
3004	gw = nhc->nhc_gw.ipv4;
3005
3006	seq_printf(m: seq,
3007	fmt: "%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(m: seq,
3019	fmt: "*\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(m: seq, c: '\n');
3025	}
3026
3027	return 0;
3028	}
3029
3030	static 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
3037	int __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(name: "fib_triestat", mode: 0444, parent: net->proc_net,
3044	show: 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
3053	out3:
3054	remove_proc_entry("fib_triestat", net->proc_net);
3055	out2:
3056	remove_proc_entry("fib_trie", net->proc_net);
3057	out1:
3058	return -ENOMEM;
3059	}
3060
3061	void __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 */
3069