Commit | Line | Data |
---|---|---|
e19f9759 | 1 | /* Copyright (C) 2006-2014 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 | ||
21 | #include <linux/list.h> | |
22 | ||
9cfc7bd6 SE |
23 | /* callback to a compare function. should compare 2 element datas for their |
24 | * keys, return 0 if same and not 0 if not same | |
25 | */ | |
5bf74e9c SE |
26 | typedef int (*batadv_hashdata_compare_cb)(const struct hlist_node *, |
27 | const void *); | |
c6c8fea2 SE |
28 | |
29 | /* the hashfunction, should return an index | |
30 | * based on the key in the data of the first | |
9cfc7bd6 SE |
31 | * argument and the size the second |
32 | */ | |
5bf74e9c SE |
33 | typedef uint32_t (*batadv_hashdata_choose_cb)(const void *, uint32_t); |
34 | typedef void (*batadv_hashdata_free_cb)(struct hlist_node *, void *); | |
c6c8fea2 | 35 | |
5bf74e9c | 36 | struct batadv_hashtable { |
fb778ea1 ML |
37 | struct hlist_head *table; /* the hashtable itself with the buckets */ |
38 | spinlock_t *list_locks; /* spinlock for each hash list entry */ | |
c90681b8 | 39 | uint32_t size; /* size of hashtable */ |
c6c8fea2 SE |
40 | }; |
41 | ||
42 | /* allocates and clears the hash */ | |
5bf74e9c | 43 | struct batadv_hashtable *batadv_hash_new(uint32_t size); |
c6c8fea2 | 44 | |
5d52dad2 | 45 | /* set class key for all locks */ |
5bf74e9c | 46 | void batadv_hash_set_lock_class(struct batadv_hashtable *hash, |
5d52dad2 SE |
47 | struct lock_class_key *key); |
48 | ||
c6c8fea2 | 49 | /* free only the hashtable and the hash itself. */ |
5bf74e9c | 50 | void batadv_hash_destroy(struct batadv_hashtable *hash); |
c6c8fea2 SE |
51 | |
52 | /* remove the hash structure. if hashdata_free_cb != NULL, this function will be | |
53 | * called to remove the elements inside of the hash. if you don't remove the | |
9cfc7bd6 SE |
54 | * elements, memory might be leaked. |
55 | */ | |
5bf74e9c SE |
56 | static inline void batadv_hash_delete(struct batadv_hashtable *hash, |
57 | batadv_hashdata_free_cb free_cb, | |
58 | void *arg) | |
c6c8fea2 SE |
59 | { |
60 | struct hlist_head *head; | |
7aadf889 | 61 | struct hlist_node *node, *node_tmp; |
fb778ea1 | 62 | spinlock_t *list_lock; /* spinlock to protect write access */ |
c90681b8 | 63 | uint32_t i; |
c6c8fea2 SE |
64 | |
65 | for (i = 0; i < hash->size; i++) { | |
66 | head = &hash->table[i]; | |
fb778ea1 | 67 | list_lock = &hash->list_locks[i]; |
c6c8fea2 | 68 | |
fb778ea1 | 69 | spin_lock_bh(list_lock); |
7aadf889 ML |
70 | hlist_for_each_safe(node, node_tmp, head) { |
71 | hlist_del_rcu(node); | |
c6c8fea2 | 72 | |
7aadf889 ML |
73 | if (free_cb) |
74 | free_cb(node, arg); | |
c6c8fea2 | 75 | } |
fb778ea1 | 76 | spin_unlock_bh(list_lock); |
c6c8fea2 SE |
77 | } |
78 | ||
1a8eaf07 | 79 | batadv_hash_destroy(hash); |
c6c8fea2 SE |
80 | } |
81 | ||
07568d03 SW |
82 | /** |
83 | * batadv_hash_bytes - hash some bytes and add them to the previous hash | |
84 | * @hash: previous hash value | |
85 | * @data: data to be hashed | |
86 | * @size: number of bytes to be hashed | |
87 | * | |
88 | * Returns the new hash value. | |
89 | */ | |
467b5fe6 | 90 | static inline uint32_t batadv_hash_bytes(uint32_t hash, const void *data, |
07568d03 SW |
91 | uint32_t size) |
92 | { | |
93 | const unsigned char *key = data; | |
94 | int i; | |
95 | ||
96 | for (i = 0; i < size; i++) { | |
97 | hash += key[i]; | |
98 | hash += (hash << 10); | |
99 | hash ^= (hash >> 6); | |
100 | } | |
101 | return hash; | |
102 | } | |
103 | ||
2c53040f BH |
104 | /** |
105 | * batadv_hash_add - adds data to the hashtable | |
1a1f37d9 AQ |
106 | * @hash: storage hash table |
107 | * @compare: callback to determine if 2 hash elements are identical | |
108 | * @choose: callback calculating the hash index | |
109 | * @data: data passed to the aforementioned callbacks as argument | |
110 | * @data_node: to be added element | |
111 | * | |
112 | * Returns 0 on success, 1 if the element already is in the hash | |
113 | * and -1 on error. | |
114 | */ | |
5bf74e9c SE |
115 | static inline int batadv_hash_add(struct batadv_hashtable *hash, |
116 | batadv_hashdata_compare_cb compare, | |
117 | batadv_hashdata_choose_cb choose, | |
c0a55929 SE |
118 | const void *data, |
119 | struct hlist_node *data_node) | |
c6c8fea2 | 120 | { |
c90681b8 AQ |
121 | uint32_t index; |
122 | int ret = -1; | |
c6c8fea2 | 123 | struct hlist_head *head; |
7aadf889 | 124 | struct hlist_node *node; |
fb778ea1 | 125 | spinlock_t *list_lock; /* spinlock to protect write access */ |
c6c8fea2 SE |
126 | |
127 | if (!hash) | |
1a1f37d9 | 128 | goto out; |
c6c8fea2 SE |
129 | |
130 | index = choose(data, hash->size); | |
131 | head = &hash->table[index]; | |
fb778ea1 | 132 | list_lock = &hash->list_locks[index]; |
c6c8fea2 | 133 | |
75c5a2e7 MS |
134 | spin_lock_bh(list_lock); |
135 | ||
136 | hlist_for_each(node, head) { | |
7aadf889 ML |
137 | if (!compare(node, data)) |
138 | continue; | |
139 | ||
1a1f37d9 | 140 | ret = 1; |
75c5a2e7 | 141 | goto unlock; |
c6c8fea2 SE |
142 | } |
143 | ||
144 | /* no duplicate found in list, add new element */ | |
7aadf889 | 145 | hlist_add_head_rcu(data_node, head); |
c6c8fea2 | 146 | |
1a1f37d9 | 147 | ret = 0; |
fb778ea1 | 148 | |
75c5a2e7 MS |
149 | unlock: |
150 | spin_unlock_bh(list_lock); | |
1a1f37d9 AQ |
151 | out: |
152 | return ret; | |
c6c8fea2 SE |
153 | } |
154 | ||
155 | /* removes data from hash, if found. returns pointer do data on success, so you | |
156 | * can remove the used structure yourself, or NULL on error . data could be the | |
157 | * structure you use with just the key filled, we just need the key for | |
9cfc7bd6 SE |
158 | * comparing. |
159 | */ | |
5bf74e9c SE |
160 | static inline void *batadv_hash_remove(struct batadv_hashtable *hash, |
161 | batadv_hashdata_compare_cb compare, | |
162 | batadv_hashdata_choose_cb choose, | |
163 | void *data) | |
c6c8fea2 | 164 | { |
c90681b8 | 165 | uint32_t index; |
7aadf889 | 166 | struct hlist_node *node; |
c6c8fea2 | 167 | struct hlist_head *head; |
fb778ea1 | 168 | void *data_save = NULL; |
c6c8fea2 SE |
169 | |
170 | index = choose(data, hash->size); | |
171 | head = &hash->table[index]; | |
172 | ||
fb778ea1 | 173 | spin_lock_bh(&hash->list_locks[index]); |
7aadf889 ML |
174 | hlist_for_each(node, head) { |
175 | if (!compare(node, data)) | |
176 | continue; | |
177 | ||
178 | data_save = node; | |
179 | hlist_del_rcu(node); | |
180 | break; | |
c6c8fea2 | 181 | } |
fb778ea1 | 182 | spin_unlock_bh(&hash->list_locks[index]); |
c6c8fea2 | 183 | |
fb778ea1 | 184 | return data_save; |
c6c8fea2 SE |
185 | } |
186 | ||
c6c8fea2 | 187 | #endif /* _NET_BATMAN_ADV_HASH_H_ */ |