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9f6446c7 | 1 | /* Copyright (C) 2006-2015 B.A.T.M.A.N. contributors: |
c6c8fea2 SE |
2 | * |
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 | |
ebf38fb7 | 15 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
c6c8fea2 SE |
16 | */ |
17 | ||
18 | #ifndef _NET_BATMAN_ADV_HASH_H_ | |
19 | #define _NET_BATMAN_ADV_HASH_H_ | |
20 | ||
1e2c2a4f SE |
21 | #include "main.h" |
22 | ||
23 | #include <linux/compiler.h> | |
c6c8fea2 | 24 | #include <linux/list.h> |
1e2c2a4f SE |
25 | #include <linux/rculist.h> |
26 | #include <linux/spinlock.h> | |
27 | #include <linux/stddef.h> | |
28 | #include <linux/types.h> | |
29 | ||
30 | struct lock_class_key; | |
c6c8fea2 | 31 | |
9cfc7bd6 SE |
32 | /* callback to a compare function. should compare 2 element datas for their |
33 | * keys, return 0 if same and not 0 if not same | |
34 | */ | |
5bf74e9c SE |
35 | typedef int (*batadv_hashdata_compare_cb)(const struct hlist_node *, |
36 | const void *); | |
c6c8fea2 SE |
37 | |
38 | /* the hashfunction, should return an index | |
39 | * based on the key in the data of the first | |
9cfc7bd6 SE |
40 | * argument and the size the second |
41 | */ | |
6b5e971a | 42 | typedef u32 (*batadv_hashdata_choose_cb)(const void *, u32); |
5bf74e9c | 43 | typedef void (*batadv_hashdata_free_cb)(struct hlist_node *, void *); |
c6c8fea2 | 44 | |
5bf74e9c | 45 | struct batadv_hashtable { |
fb778ea1 ML |
46 | struct hlist_head *table; /* the hashtable itself with the buckets */ |
47 | spinlock_t *list_locks; /* spinlock for each hash list entry */ | |
6b5e971a | 48 | u32 size; /* size of hashtable */ |
c6c8fea2 SE |
49 | }; |
50 | ||
51 | /* allocates and clears the hash */ | |
6b5e971a | 52 | struct batadv_hashtable *batadv_hash_new(u32 size); |
c6c8fea2 | 53 | |
5d52dad2 | 54 | /* set class key for all locks */ |
5bf74e9c | 55 | void batadv_hash_set_lock_class(struct batadv_hashtable *hash, |
5d52dad2 SE |
56 | struct lock_class_key *key); |
57 | ||
c6c8fea2 | 58 | /* free only the hashtable and the hash itself. */ |
5bf74e9c | 59 | void batadv_hash_destroy(struct batadv_hashtable *hash); |
c6c8fea2 SE |
60 | |
61 | /* remove the hash structure. if hashdata_free_cb != NULL, this function will be | |
62 | * called to remove the elements inside of the hash. if you don't remove the | |
9cfc7bd6 SE |
63 | * elements, memory might be leaked. |
64 | */ | |
5bf74e9c SE |
65 | static inline void batadv_hash_delete(struct batadv_hashtable *hash, |
66 | batadv_hashdata_free_cb free_cb, | |
67 | void *arg) | |
c6c8fea2 SE |
68 | { |
69 | struct hlist_head *head; | |
7aadf889 | 70 | struct hlist_node *node, *node_tmp; |
fb778ea1 | 71 | spinlock_t *list_lock; /* spinlock to protect write access */ |
6b5e971a | 72 | u32 i; |
c6c8fea2 SE |
73 | |
74 | for (i = 0; i < hash->size; i++) { | |
75 | head = &hash->table[i]; | |
fb778ea1 | 76 | list_lock = &hash->list_locks[i]; |
c6c8fea2 | 77 | |
fb778ea1 | 78 | spin_lock_bh(list_lock); |
7aadf889 ML |
79 | hlist_for_each_safe(node, node_tmp, head) { |
80 | hlist_del_rcu(node); | |
c6c8fea2 | 81 | |
7aadf889 ML |
82 | if (free_cb) |
83 | free_cb(node, arg); | |
c6c8fea2 | 84 | } |
fb778ea1 | 85 | spin_unlock_bh(list_lock); |
c6c8fea2 SE |
86 | } |
87 | ||
1a8eaf07 | 88 | batadv_hash_destroy(hash); |
c6c8fea2 SE |
89 | } |
90 | ||
2c53040f BH |
91 | /** |
92 | * batadv_hash_add - adds data to the hashtable | |
1a1f37d9 AQ |
93 | * @hash: storage hash table |
94 | * @compare: callback to determine if 2 hash elements are identical | |
95 | * @choose: callback calculating the hash index | |
96 | * @data: data passed to the aforementioned callbacks as argument | |
97 | * @data_node: to be added element | |
98 | * | |
99 | * Returns 0 on success, 1 if the element already is in the hash | |
100 | * and -1 on error. | |
101 | */ | |
5bf74e9c SE |
102 | static inline int batadv_hash_add(struct batadv_hashtable *hash, |
103 | batadv_hashdata_compare_cb compare, | |
104 | batadv_hashdata_choose_cb choose, | |
c0a55929 SE |
105 | const void *data, |
106 | struct hlist_node *data_node) | |
c6c8fea2 | 107 | { |
6b5e971a | 108 | u32 index; |
c90681b8 | 109 | int ret = -1; |
c6c8fea2 | 110 | struct hlist_head *head; |
7aadf889 | 111 | struct hlist_node *node; |
fb778ea1 | 112 | spinlock_t *list_lock; /* spinlock to protect write access */ |
c6c8fea2 SE |
113 | |
114 | if (!hash) | |
1a1f37d9 | 115 | goto out; |
c6c8fea2 SE |
116 | |
117 | index = choose(data, hash->size); | |
118 | head = &hash->table[index]; | |
fb778ea1 | 119 | list_lock = &hash->list_locks[index]; |
c6c8fea2 | 120 | |
75c5a2e7 MS |
121 | spin_lock_bh(list_lock); |
122 | ||
123 | hlist_for_each(node, head) { | |
7aadf889 ML |
124 | if (!compare(node, data)) |
125 | continue; | |
126 | ||
1a1f37d9 | 127 | ret = 1; |
75c5a2e7 | 128 | goto unlock; |
c6c8fea2 SE |
129 | } |
130 | ||
131 | /* no duplicate found in list, add new element */ | |
7aadf889 | 132 | hlist_add_head_rcu(data_node, head); |
c6c8fea2 | 133 | |
1a1f37d9 | 134 | ret = 0; |
fb778ea1 | 135 | |
75c5a2e7 MS |
136 | unlock: |
137 | spin_unlock_bh(list_lock); | |
1a1f37d9 AQ |
138 | out: |
139 | return ret; | |
c6c8fea2 SE |
140 | } |
141 | ||
142 | /* removes data from hash, if found. returns pointer do data on success, so you | |
143 | * can remove the used structure yourself, or NULL on error . data could be the | |
144 | * structure you use with just the key filled, we just need the key for | |
9cfc7bd6 SE |
145 | * comparing. |
146 | */ | |
5bf74e9c SE |
147 | static inline void *batadv_hash_remove(struct batadv_hashtable *hash, |
148 | batadv_hashdata_compare_cb compare, | |
149 | batadv_hashdata_choose_cb choose, | |
150 | void *data) | |
c6c8fea2 | 151 | { |
6b5e971a | 152 | u32 index; |
7aadf889 | 153 | struct hlist_node *node; |
c6c8fea2 | 154 | struct hlist_head *head; |
fb778ea1 | 155 | void *data_save = NULL; |
c6c8fea2 SE |
156 | |
157 | index = choose(data, hash->size); | |
158 | head = &hash->table[index]; | |
159 | ||
fb778ea1 | 160 | spin_lock_bh(&hash->list_locks[index]); |
7aadf889 ML |
161 | hlist_for_each(node, head) { |
162 | if (!compare(node, data)) | |
163 | continue; | |
164 | ||
165 | data_save = node; | |
166 | hlist_del_rcu(node); | |
167 | break; | |
c6c8fea2 | 168 | } |
fb778ea1 | 169 | spin_unlock_bh(&hash->list_locks[index]); |
c6c8fea2 | 170 | |
fb778ea1 | 171 | return data_save; |
c6c8fea2 SE |
172 | } |
173 | ||
c6c8fea2 | 174 | #endif /* _NET_BATMAN_ADV_HASH_H_ */ |