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9cfc7bd6 | 1 | /* Copyright (C) 2006-2012 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 | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA | |
17 | * 02110-1301, USA | |
c6c8fea2 SE |
18 | */ |
19 | ||
20 | #ifndef _NET_BATMAN_ADV_HASH_H_ | |
21 | #define _NET_BATMAN_ADV_HASH_H_ | |
22 | ||
23 | #include <linux/list.h> | |
24 | ||
9cfc7bd6 SE |
25 | /* callback to a compare function. should compare 2 element datas for their |
26 | * keys, return 0 if same and not 0 if not same | |
27 | */ | |
5bf74e9c SE |
28 | typedef int (*batadv_hashdata_compare_cb)(const struct hlist_node *, |
29 | const void *); | |
c6c8fea2 SE |
30 | |
31 | /* the hashfunction, should return an index | |
32 | * based on the key in the data of the first | |
9cfc7bd6 SE |
33 | * argument and the size the second |
34 | */ | |
5bf74e9c SE |
35 | typedef uint32_t (*batadv_hashdata_choose_cb)(const void *, uint32_t); |
36 | typedef void (*batadv_hashdata_free_cb)(struct hlist_node *, void *); | |
c6c8fea2 | 37 | |
5bf74e9c | 38 | struct batadv_hashtable { |
fb778ea1 ML |
39 | struct hlist_head *table; /* the hashtable itself with the buckets */ |
40 | spinlock_t *list_locks; /* spinlock for each hash list entry */ | |
c90681b8 | 41 | uint32_t size; /* size of hashtable */ |
c6c8fea2 SE |
42 | }; |
43 | ||
44 | /* allocates and clears the hash */ | |
5bf74e9c | 45 | struct batadv_hashtable *batadv_hash_new(uint32_t size); |
c6c8fea2 | 46 | |
5d52dad2 | 47 | /* set class key for all locks */ |
5bf74e9c | 48 | void batadv_hash_set_lock_class(struct batadv_hashtable *hash, |
5d52dad2 SE |
49 | struct lock_class_key *key); |
50 | ||
c6c8fea2 | 51 | /* free only the hashtable and the hash itself. */ |
5bf74e9c | 52 | void batadv_hash_destroy(struct batadv_hashtable *hash); |
c6c8fea2 SE |
53 | |
54 | /* remove the hash structure. if hashdata_free_cb != NULL, this function will be | |
55 | * called to remove the elements inside of the hash. if you don't remove the | |
9cfc7bd6 SE |
56 | * elements, memory might be leaked. |
57 | */ | |
5bf74e9c SE |
58 | static inline void batadv_hash_delete(struct batadv_hashtable *hash, |
59 | batadv_hashdata_free_cb free_cb, | |
60 | void *arg) | |
c6c8fea2 SE |
61 | { |
62 | struct hlist_head *head; | |
7aadf889 | 63 | struct hlist_node *node, *node_tmp; |
fb778ea1 | 64 | spinlock_t *list_lock; /* spinlock to protect write access */ |
c90681b8 | 65 | uint32_t i; |
c6c8fea2 SE |
66 | |
67 | for (i = 0; i < hash->size; i++) { | |
68 | head = &hash->table[i]; | |
fb778ea1 | 69 | list_lock = &hash->list_locks[i]; |
c6c8fea2 | 70 | |
fb778ea1 | 71 | spin_lock_bh(list_lock); |
7aadf889 ML |
72 | hlist_for_each_safe(node, node_tmp, head) { |
73 | hlist_del_rcu(node); | |
c6c8fea2 | 74 | |
7aadf889 ML |
75 | if (free_cb) |
76 | free_cb(node, arg); | |
c6c8fea2 | 77 | } |
fb778ea1 | 78 | spin_unlock_bh(list_lock); |
c6c8fea2 SE |
79 | } |
80 | ||
1a8eaf07 | 81 | batadv_hash_destroy(hash); |
c6c8fea2 SE |
82 | } |
83 | ||
2c53040f BH |
84 | /** |
85 | * batadv_hash_add - adds data to the hashtable | |
1a1f37d9 AQ |
86 | * @hash: storage hash table |
87 | * @compare: callback to determine if 2 hash elements are identical | |
88 | * @choose: callback calculating the hash index | |
89 | * @data: data passed to the aforementioned callbacks as argument | |
90 | * @data_node: to be added element | |
91 | * | |
92 | * Returns 0 on success, 1 if the element already is in the hash | |
93 | * and -1 on error. | |
94 | */ | |
5bf74e9c SE |
95 | static inline int batadv_hash_add(struct batadv_hashtable *hash, |
96 | batadv_hashdata_compare_cb compare, | |
97 | batadv_hashdata_choose_cb choose, | |
c0a55929 SE |
98 | const void *data, |
99 | struct hlist_node *data_node) | |
c6c8fea2 | 100 | { |
c90681b8 AQ |
101 | uint32_t index; |
102 | int ret = -1; | |
c6c8fea2 | 103 | struct hlist_head *head; |
7aadf889 | 104 | struct hlist_node *node; |
fb778ea1 | 105 | spinlock_t *list_lock; /* spinlock to protect write access */ |
c6c8fea2 SE |
106 | |
107 | if (!hash) | |
1a1f37d9 | 108 | goto out; |
c6c8fea2 SE |
109 | |
110 | index = choose(data, hash->size); | |
111 | head = &hash->table[index]; | |
fb778ea1 | 112 | list_lock = &hash->list_locks[index]; |
c6c8fea2 | 113 | |
75c5a2e7 MS |
114 | spin_lock_bh(list_lock); |
115 | ||
116 | hlist_for_each(node, head) { | |
7aadf889 ML |
117 | if (!compare(node, data)) |
118 | continue; | |
119 | ||
1a1f37d9 | 120 | ret = 1; |
75c5a2e7 | 121 | goto unlock; |
c6c8fea2 SE |
122 | } |
123 | ||
124 | /* no duplicate found in list, add new element */ | |
7aadf889 | 125 | hlist_add_head_rcu(data_node, head); |
c6c8fea2 | 126 | |
1a1f37d9 | 127 | ret = 0; |
fb778ea1 | 128 | |
75c5a2e7 MS |
129 | unlock: |
130 | spin_unlock_bh(list_lock); | |
1a1f37d9 AQ |
131 | out: |
132 | return ret; | |
c6c8fea2 SE |
133 | } |
134 | ||
135 | /* removes data from hash, if found. returns pointer do data on success, so you | |
136 | * can remove the used structure yourself, or NULL on error . data could be the | |
137 | * structure you use with just the key filled, we just need the key for | |
9cfc7bd6 SE |
138 | * comparing. |
139 | */ | |
5bf74e9c SE |
140 | static inline void *batadv_hash_remove(struct batadv_hashtable *hash, |
141 | batadv_hashdata_compare_cb compare, | |
142 | batadv_hashdata_choose_cb choose, | |
143 | void *data) | |
c6c8fea2 | 144 | { |
c90681b8 | 145 | uint32_t index; |
7aadf889 | 146 | struct hlist_node *node; |
c6c8fea2 | 147 | struct hlist_head *head; |
fb778ea1 | 148 | void *data_save = NULL; |
c6c8fea2 SE |
149 | |
150 | index = choose(data, hash->size); | |
151 | head = &hash->table[index]; | |
152 | ||
fb778ea1 | 153 | spin_lock_bh(&hash->list_locks[index]); |
7aadf889 ML |
154 | hlist_for_each(node, head) { |
155 | if (!compare(node, data)) | |
156 | continue; | |
157 | ||
158 | data_save = node; | |
159 | hlist_del_rcu(node); | |
160 | break; | |
c6c8fea2 | 161 | } |
fb778ea1 | 162 | spin_unlock_bh(&hash->list_locks[index]); |
c6c8fea2 | 163 | |
fb778ea1 | 164 | return data_save; |
c6c8fea2 SE |
165 | } |
166 | ||
c6c8fea2 | 167 | #endif /* _NET_BATMAN_ADV_HASH_H_ */ |