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c6c8fea2 | 1 | /* |
567db7b0 | 2 | * Copyright (C) 2006-2012 B.A.T.M.A.N. contributors: |
c6c8fea2 SE |
3 | * |
4 | * Simon Wunderlich, Marek Lindner | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of version 2 of the GNU General Public | |
8 | * License as published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, but | |
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA | |
18 | * 02110-1301, USA | |
19 | * | |
20 | */ | |
21 | ||
22 | #ifndef _NET_BATMAN_ADV_HASH_H_ | |
23 | #define _NET_BATMAN_ADV_HASH_H_ | |
24 | ||
25 | #include <linux/list.h> | |
26 | ||
27 | /* callback to a compare function. should | |
28 | * compare 2 element datas for their keys, | |
29 | * return 0 if same and not 0 if not | |
30 | * same */ | |
747e4221 | 31 | typedef int (*hashdata_compare_cb)(const struct hlist_node *, const void *); |
c6c8fea2 SE |
32 | |
33 | /* the hashfunction, should return an index | |
34 | * based on the key in the data of the first | |
35 | * argument and the size the second */ | |
c90681b8 | 36 | typedef uint32_t (*hashdata_choose_cb)(const void *, uint32_t); |
7aadf889 | 37 | typedef void (*hashdata_free_cb)(struct hlist_node *, void *); |
c6c8fea2 SE |
38 | |
39 | struct hashtable_t { | |
fb778ea1 ML |
40 | struct hlist_head *table; /* the hashtable itself with the buckets */ |
41 | spinlock_t *list_locks; /* spinlock for each hash list entry */ | |
c90681b8 | 42 | uint32_t size; /* size of hashtable */ |
c6c8fea2 SE |
43 | }; |
44 | ||
45 | /* allocates and clears the hash */ | |
c90681b8 | 46 | struct hashtable_t *hash_new(uint32_t size); |
c6c8fea2 | 47 | |
5d52dad2 SE |
48 | /* set class key for all locks */ |
49 | void batadv_hash_set_lock_class(struct hashtable_t *hash, | |
50 | struct lock_class_key *key); | |
51 | ||
c6c8fea2 SE |
52 | /* free only the hashtable and the hash itself. */ |
53 | void hash_destroy(struct hashtable_t *hash); | |
54 | ||
55 | /* remove the hash structure. if hashdata_free_cb != NULL, this function will be | |
56 | * called to remove the elements inside of the hash. if you don't remove the | |
57 | * elements, memory might be leaked. */ | |
58 | static inline void hash_delete(struct hashtable_t *hash, | |
59 | hashdata_free_cb free_cb, void *arg) | |
60 | { | |
61 | struct hlist_head *head; | |
7aadf889 | 62 | struct hlist_node *node, *node_tmp; |
fb778ea1 | 63 | spinlock_t *list_lock; /* spinlock to protect write access */ |
c90681b8 | 64 | uint32_t i; |
c6c8fea2 SE |
65 | |
66 | for (i = 0; i < hash->size; i++) { | |
67 | head = &hash->table[i]; | |
fb778ea1 | 68 | list_lock = &hash->list_locks[i]; |
c6c8fea2 | 69 | |
fb778ea1 | 70 | spin_lock_bh(list_lock); |
7aadf889 ML |
71 | hlist_for_each_safe(node, node_tmp, head) { |
72 | hlist_del_rcu(node); | |
c6c8fea2 | 73 | |
7aadf889 ML |
74 | if (free_cb) |
75 | free_cb(node, arg); | |
c6c8fea2 | 76 | } |
fb778ea1 | 77 | spin_unlock_bh(list_lock); |
c6c8fea2 SE |
78 | } |
79 | ||
80 | hash_destroy(hash); | |
81 | } | |
82 | ||
1a1f37d9 AQ |
83 | /** |
84 | * hash_add - adds data to the hashtable | |
85 | * @hash: storage hash table | |
86 | * @compare: callback to determine if 2 hash elements are identical | |
87 | * @choose: callback calculating the hash index | |
88 | * @data: data passed to the aforementioned callbacks as argument | |
89 | * @data_node: to be added element | |
90 | * | |
91 | * Returns 0 on success, 1 if the element already is in the hash | |
92 | * and -1 on error. | |
93 | */ | |
94 | ||
c6c8fea2 SE |
95 | static inline int hash_add(struct hashtable_t *hash, |
96 | hashdata_compare_cb compare, | |
7aadf889 | 97 | hashdata_choose_cb choose, |
747e4221 | 98 | const void *data, struct hlist_node *data_node) |
c6c8fea2 | 99 | { |
c90681b8 AQ |
100 | uint32_t index; |
101 | int ret = -1; | |
c6c8fea2 | 102 | struct hlist_head *head; |
7aadf889 | 103 | struct hlist_node *node; |
fb778ea1 | 104 | spinlock_t *list_lock; /* spinlock to protect write access */ |
c6c8fea2 SE |
105 | |
106 | if (!hash) | |
1a1f37d9 | 107 | goto out; |
c6c8fea2 SE |
108 | |
109 | index = choose(data, hash->size); | |
110 | head = &hash->table[index]; | |
fb778ea1 | 111 | list_lock = &hash->list_locks[index]; |
c6c8fea2 | 112 | |
fb778ea1 | 113 | rcu_read_lock(); |
7aadf889 ML |
114 | __hlist_for_each_rcu(node, head) { |
115 | if (!compare(node, data)) | |
116 | continue; | |
117 | ||
1a1f37d9 | 118 | ret = 1; |
7aadf889 | 119 | goto err_unlock; |
c6c8fea2 | 120 | } |
fb778ea1 | 121 | rcu_read_unlock(); |
c6c8fea2 SE |
122 | |
123 | /* no duplicate found in list, add new element */ | |
fb778ea1 | 124 | spin_lock_bh(list_lock); |
7aadf889 | 125 | hlist_add_head_rcu(data_node, head); |
fb778ea1 | 126 | spin_unlock_bh(list_lock); |
c6c8fea2 | 127 | |
1a1f37d9 AQ |
128 | ret = 0; |
129 | goto out; | |
fb778ea1 ML |
130 | |
131 | err_unlock: | |
132 | rcu_read_unlock(); | |
1a1f37d9 AQ |
133 | out: |
134 | return ret; | |
c6c8fea2 SE |
135 | } |
136 | ||
137 | /* removes data from hash, if found. returns pointer do data on success, so you | |
138 | * can remove the used structure yourself, or NULL on error . data could be the | |
139 | * structure you use with just the key filled, we just need the key for | |
140 | * comparing. */ | |
141 | static inline void *hash_remove(struct hashtable_t *hash, | |
142 | hashdata_compare_cb compare, | |
143 | hashdata_choose_cb choose, void *data) | |
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_ */ |