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Sven Eckelmann0046b042016-01-01 00:01:03 +01001/* Copyright (C) 2006-2016 B.A.T.M.A.N. contributors:
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +00002 *
3 * Simon Wunderlich, Marek Lindner
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of version 2 of the GNU General Public
7 * License as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
Antonio Quartulliebf38fb2013-11-03 20:40:48 +010015 * along with this program; if not, see <http://www.gnu.org/licenses/>.
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +000016 */
17
18#ifndef _NET_BATMAN_ADV_HASH_H_
19#define _NET_BATMAN_ADV_HASH_H_
20
Sven Eckelmann1e2c2a42015-04-17 19:40:28 +020021#include "main.h"
22
23#include <linux/compiler.h>
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +000024#include <linux/list.h>
Sven Eckelmann1e2c2a42015-04-17 19:40:28 +020025#include <linux/rculist.h>
26#include <linux/spinlock.h>
27#include <linux/stddef.h>
28#include <linux/types.h>
29
30struct lock_class_key;
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +000031
Sven Eckelmann9cfc7bd2012-05-12 02:09:43 +020032/* callback to a compare function. should compare 2 element datas for their
Sven Eckelmann62fe7102015-09-15 19:00:48 +020033 * keys
34 *
35 * Return: 0 if same and not 0 if not same
Sven Eckelmann9cfc7bd2012-05-12 02:09:43 +020036 */
Sven Eckelmann5bf74e92012-06-05 22:31:28 +020037typedef int (*batadv_hashdata_compare_cb)(const struct hlist_node *,
38 const void *);
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +000039
Sven Eckelmann62fe7102015-09-15 19:00:48 +020040/* the hashfunction
41 *
42 * Return: an index based on the key in the data of the first argument and the
43 * size the second
Sven Eckelmann9cfc7bd2012-05-12 02:09:43 +020044 */
Sven Eckelmann6b5e9712015-05-26 18:34:26 +020045typedef u32 (*batadv_hashdata_choose_cb)(const void *, u32);
Sven Eckelmann5bf74e92012-06-05 22:31:28 +020046typedef void (*batadv_hashdata_free_cb)(struct hlist_node *, void *);
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +000047
Sven Eckelmann5bf74e92012-06-05 22:31:28 +020048struct batadv_hashtable {
Marek Lindnerfb778ea2011-01-19 20:01:40 +000049 struct hlist_head *table; /* the hashtable itself with the buckets */
50 spinlock_t *list_locks; /* spinlock for each hash list entry */
Sven Eckelmann6b5e9712015-05-26 18:34:26 +020051 u32 size; /* size of hashtable */
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +000052};
53
54/* allocates and clears the hash */
Sven Eckelmann6b5e9712015-05-26 18:34:26 +020055struct batadv_hashtable *batadv_hash_new(u32 size);
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +000056
Sven Eckelmann5d52dad2012-03-29 12:38:20 +020057/* set class key for all locks */
Sven Eckelmann5bf74e92012-06-05 22:31:28 +020058void batadv_hash_set_lock_class(struct batadv_hashtable *hash,
Sven Eckelmann5d52dad2012-03-29 12:38:20 +020059 struct lock_class_key *key);
60
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +000061/* free only the hashtable and the hash itself. */
Sven Eckelmann5bf74e92012-06-05 22:31:28 +020062void batadv_hash_destroy(struct batadv_hashtable *hash);
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +000063
64/* remove the hash structure. if hashdata_free_cb != NULL, this function will be
65 * called to remove the elements inside of the hash. if you don't remove the
Sven Eckelmann9cfc7bd2012-05-12 02:09:43 +020066 * elements, memory might be leaked.
67 */
Sven Eckelmann5bf74e92012-06-05 22:31:28 +020068static inline void batadv_hash_delete(struct batadv_hashtable *hash,
69 batadv_hashdata_free_cb free_cb,
70 void *arg)
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +000071{
72 struct hlist_head *head;
Marek Lindner7aadf882011-02-18 12:28:09 +000073 struct hlist_node *node, *node_tmp;
Marek Lindnerfb778ea2011-01-19 20:01:40 +000074 spinlock_t *list_lock; /* spinlock to protect write access */
Sven Eckelmann6b5e9712015-05-26 18:34:26 +020075 u32 i;
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +000076
77 for (i = 0; i < hash->size; i++) {
78 head = &hash->table[i];
Marek Lindnerfb778ea2011-01-19 20:01:40 +000079 list_lock = &hash->list_locks[i];
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +000080
Marek Lindnerfb778ea2011-01-19 20:01:40 +000081 spin_lock_bh(list_lock);
Marek Lindner7aadf882011-02-18 12:28:09 +000082 hlist_for_each_safe(node, node_tmp, head) {
83 hlist_del_rcu(node);
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +000084
Marek Lindner7aadf882011-02-18 12:28:09 +000085 if (free_cb)
86 free_cb(node, arg);
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +000087 }
Marek Lindnerfb778ea2011-01-19 20:01:40 +000088 spin_unlock_bh(list_lock);
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +000089 }
90
Sven Eckelmann1a8eaf02012-05-12 02:09:32 +020091 batadv_hash_destroy(hash);
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +000092}
93
Ben Hutchings2c530402012-07-10 10:55:09 +000094/**
95 * batadv_hash_add - adds data to the hashtable
Antonio Quartulli1a1f37d2011-07-10 00:36:36 +020096 * @hash: storage hash table
97 * @compare: callback to determine if 2 hash elements are identical
98 * @choose: callback calculating the hash index
99 * @data: data passed to the aforementioned callbacks as argument
100 * @data_node: to be added element
101 *
Sven Eckelmann62fe7102015-09-15 19:00:48 +0200102 * Return: 0 on success, 1 if the element already is in the hash
Antonio Quartulli1a1f37d2011-07-10 00:36:36 +0200103 * and -1 on error.
104 */
Sven Eckelmann5bf74e92012-06-05 22:31:28 +0200105static inline int batadv_hash_add(struct batadv_hashtable *hash,
106 batadv_hashdata_compare_cb compare,
107 batadv_hashdata_choose_cb choose,
Sven Eckelmannc0a55922012-05-12 13:48:55 +0200108 const void *data,
109 struct hlist_node *data_node)
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +0000110{
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200111 u32 index;
Antonio Quartullic90681b2011-10-05 17:05:25 +0200112 int ret = -1;
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +0000113 struct hlist_head *head;
Marek Lindner7aadf882011-02-18 12:28:09 +0000114 struct hlist_node *node;
Marek Lindnerfb778ea2011-01-19 20:01:40 +0000115 spinlock_t *list_lock; /* spinlock to protect write access */
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +0000116
117 if (!hash)
Antonio Quartulli1a1f37d2011-07-10 00:36:36 +0200118 goto out;
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +0000119
120 index = choose(data, hash->size);
121 head = &hash->table[index];
Marek Lindnerfb778ea2011-01-19 20:01:40 +0000122 list_lock = &hash->list_locks[index];
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +0000123
Matthias Schiffer75c5a2e2012-05-08 22:31:57 +0200124 spin_lock_bh(list_lock);
125
126 hlist_for_each(node, head) {
Marek Lindner7aadf882011-02-18 12:28:09 +0000127 if (!compare(node, data))
128 continue;
129
Antonio Quartulli1a1f37d2011-07-10 00:36:36 +0200130 ret = 1;
Matthias Schiffer75c5a2e2012-05-08 22:31:57 +0200131 goto unlock;
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +0000132 }
133
134 /* no duplicate found in list, add new element */
Marek Lindner7aadf882011-02-18 12:28:09 +0000135 hlist_add_head_rcu(data_node, head);
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +0000136
Antonio Quartulli1a1f37d2011-07-10 00:36:36 +0200137 ret = 0;
Marek Lindnerfb778ea2011-01-19 20:01:40 +0000138
Matthias Schiffer75c5a2e2012-05-08 22:31:57 +0200139unlock:
140 spin_unlock_bh(list_lock);
Antonio Quartulli1a1f37d2011-07-10 00:36:36 +0200141out:
142 return ret;
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +0000143}
144
Sven Eckelmann62fe7102015-09-15 19:00:48 +0200145/* removes data from hash, if found. data could be the structure you use with
146 * just the key filled, we just need the key for comparing.
147 *
148 * Return: returns pointer do data on success, so you can remove the used
149 * structure yourself, or NULL on error
Sven Eckelmann9cfc7bd2012-05-12 02:09:43 +0200150 */
Sven Eckelmann5bf74e92012-06-05 22:31:28 +0200151static inline void *batadv_hash_remove(struct batadv_hashtable *hash,
152 batadv_hashdata_compare_cb compare,
153 batadv_hashdata_choose_cb choose,
154 void *data)
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +0000155{
Sven Eckelmann6b5e9712015-05-26 18:34:26 +0200156 u32 index;
Marek Lindner7aadf882011-02-18 12:28:09 +0000157 struct hlist_node *node;
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +0000158 struct hlist_head *head;
Marek Lindnerfb778ea2011-01-19 20:01:40 +0000159 void *data_save = NULL;
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +0000160
161 index = choose(data, hash->size);
162 head = &hash->table[index];
163
Marek Lindnerfb778ea2011-01-19 20:01:40 +0000164 spin_lock_bh(&hash->list_locks[index]);
Marek Lindner7aadf882011-02-18 12:28:09 +0000165 hlist_for_each(node, head) {
166 if (!compare(node, data))
167 continue;
168
169 data_save = node;
170 hlist_del_rcu(node);
171 break;
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +0000172 }
Marek Lindnerfb778ea2011-01-19 20:01:40 +0000173 spin_unlock_bh(&hash->list_locks[index]);
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +0000174
Marek Lindnerfb778ea2011-01-19 20:01:40 +0000175 return data_save;
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +0000176}
177
Sven Eckelmannc6c8fea2010-12-13 11:19:28 +0000178#endif /* _NET_BATMAN_ADV_HASH_H_ */