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0046b040 | 1 | /* Copyright (C) 2006-2016 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 | 32 | /* callback to a compare function. should compare 2 element datas for their |
62fe710f SE |
33 | * keys |
34 | * | |
4b426b10 | 35 | * Return: true if same and false if not same |
9cfc7bd6 | 36 | */ |
4b426b10 SE |
37 | typedef bool (*batadv_hashdata_compare_cb)(const struct hlist_node *, |
38 | const void *); | |
c6c8fea2 | 39 | |
62fe710f SE |
40 | /* the hashfunction |
41 | * | |
42 | * Return: an index based on the key in the data of the first argument and the | |
43 | * size the second | |
9cfc7bd6 | 44 | */ |
6b5e971a | 45 | typedef u32 (*batadv_hashdata_choose_cb)(const void *, u32); |
5bf74e9c | 46 | typedef void (*batadv_hashdata_free_cb)(struct hlist_node *, void *); |
c6c8fea2 | 47 | |
5bf74e9c | 48 | struct batadv_hashtable { |
fb778ea1 ML |
49 | struct hlist_head *table; /* the hashtable itself with the buckets */ |
50 | spinlock_t *list_locks; /* spinlock for each hash list entry */ | |
6b5e971a | 51 | u32 size; /* size of hashtable */ |
c6c8fea2 SE |
52 | }; |
53 | ||
54 | /* allocates and clears the hash */ | |
6b5e971a | 55 | struct batadv_hashtable *batadv_hash_new(u32 size); |
c6c8fea2 | 56 | |
5d52dad2 | 57 | /* set class key for all locks */ |
5bf74e9c | 58 | void batadv_hash_set_lock_class(struct batadv_hashtable *hash, |
5d52dad2 SE |
59 | struct lock_class_key *key); |
60 | ||
c6c8fea2 | 61 | /* free only the hashtable and the hash itself. */ |
5bf74e9c | 62 | void batadv_hash_destroy(struct batadv_hashtable *hash); |
c6c8fea2 SE |
63 | |
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 | |
9cfc7bd6 SE |
66 | * elements, memory might be leaked. |
67 | */ | |
5bf74e9c SE |
68 | static inline void batadv_hash_delete(struct batadv_hashtable *hash, |
69 | batadv_hashdata_free_cb free_cb, | |
70 | void *arg) | |
c6c8fea2 SE |
71 | { |
72 | struct hlist_head *head; | |
7aadf889 | 73 | struct hlist_node *node, *node_tmp; |
fb778ea1 | 74 | spinlock_t *list_lock; /* spinlock to protect write access */ |
6b5e971a | 75 | u32 i; |
c6c8fea2 SE |
76 | |
77 | for (i = 0; i < hash->size; i++) { | |
78 | head = &hash->table[i]; | |
fb778ea1 | 79 | list_lock = &hash->list_locks[i]; |
c6c8fea2 | 80 | |
fb778ea1 | 81 | spin_lock_bh(list_lock); |
7aadf889 ML |
82 | hlist_for_each_safe(node, node_tmp, head) { |
83 | hlist_del_rcu(node); | |
c6c8fea2 | 84 | |
7aadf889 ML |
85 | if (free_cb) |
86 | free_cb(node, arg); | |
c6c8fea2 | 87 | } |
fb778ea1 | 88 | spin_unlock_bh(list_lock); |
c6c8fea2 SE |
89 | } |
90 | ||
1a8eaf07 | 91 | batadv_hash_destroy(hash); |
c6c8fea2 SE |
92 | } |
93 | ||
2c53040f BH |
94 | /** |
95 | * batadv_hash_add - adds data to the hashtable | |
1a1f37d9 AQ |
96 | * @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 | * | |
62fe710f | 102 | * Return: 0 on success, 1 if the element already is in the hash |
1a1f37d9 AQ |
103 | * and -1 on error. |
104 | */ | |
5bf74e9c SE |
105 | static inline int batadv_hash_add(struct batadv_hashtable *hash, |
106 | batadv_hashdata_compare_cb compare, | |
107 | batadv_hashdata_choose_cb choose, | |
c0a55929 SE |
108 | const void *data, |
109 | struct hlist_node *data_node) | |
c6c8fea2 | 110 | { |
6b5e971a | 111 | u32 index; |
c90681b8 | 112 | int ret = -1; |
c6c8fea2 | 113 | struct hlist_head *head; |
7aadf889 | 114 | struct hlist_node *node; |
fb778ea1 | 115 | spinlock_t *list_lock; /* spinlock to protect write access */ |
c6c8fea2 SE |
116 | |
117 | if (!hash) | |
1a1f37d9 | 118 | goto out; |
c6c8fea2 SE |
119 | |
120 | index = choose(data, hash->size); | |
121 | head = &hash->table[index]; | |
fb778ea1 | 122 | list_lock = &hash->list_locks[index]; |
c6c8fea2 | 123 | |
75c5a2e7 MS |
124 | spin_lock_bh(list_lock); |
125 | ||
126 | hlist_for_each(node, head) { | |
7aadf889 ML |
127 | if (!compare(node, data)) |
128 | continue; | |
129 | ||
1a1f37d9 | 130 | ret = 1; |
75c5a2e7 | 131 | goto unlock; |
c6c8fea2 SE |
132 | } |
133 | ||
134 | /* no duplicate found in list, add new element */ | |
7aadf889 | 135 | hlist_add_head_rcu(data_node, head); |
c6c8fea2 | 136 | |
1a1f37d9 | 137 | ret = 0; |
fb778ea1 | 138 | |
75c5a2e7 MS |
139 | unlock: |
140 | spin_unlock_bh(list_lock); | |
1a1f37d9 AQ |
141 | out: |
142 | return ret; | |
c6c8fea2 SE |
143 | } |
144 | ||
62fe710f SE |
145 | /* 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 | |
9cfc7bd6 | 150 | */ |
5bf74e9c SE |
151 | static inline void *batadv_hash_remove(struct batadv_hashtable *hash, |
152 | batadv_hashdata_compare_cb compare, | |
153 | batadv_hashdata_choose_cb choose, | |
154 | void *data) | |
c6c8fea2 | 155 | { |
6b5e971a | 156 | u32 index; |
7aadf889 | 157 | struct hlist_node *node; |
c6c8fea2 | 158 | struct hlist_head *head; |
fb778ea1 | 159 | void *data_save = NULL; |
c6c8fea2 SE |
160 | |
161 | index = choose(data, hash->size); | |
162 | head = &hash->table[index]; | |
163 | ||
fb778ea1 | 164 | spin_lock_bh(&hash->list_locks[index]); |
7aadf889 ML |
165 | hlist_for_each(node, head) { |
166 | if (!compare(node, data)) | |
167 | continue; | |
168 | ||
169 | data_save = node; | |
170 | hlist_del_rcu(node); | |
171 | break; | |
c6c8fea2 | 172 | } |
fb778ea1 | 173 | spin_unlock_bh(&hash->list_locks[index]); |
c6c8fea2 | 174 | |
fb778ea1 | 175 | return data_save; |
c6c8fea2 SE |
176 | } |
177 | ||
c6c8fea2 | 178 | #endif /* _NET_BATMAN_ADV_HASH_H_ */ |