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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 | */ | |
747e4221 | 28 | typedef int (*hashdata_compare_cb)(const struct hlist_node *, const void *); |
c6c8fea2 SE |
29 | |
30 | /* the hashfunction, should return an index | |
31 | * based on the key in the data of the first | |
9cfc7bd6 SE |
32 | * argument and the size the second |
33 | */ | |
c90681b8 | 34 | typedef uint32_t (*hashdata_choose_cb)(const void *, uint32_t); |
7aadf889 | 35 | typedef void (*hashdata_free_cb)(struct hlist_node *, void *); |
c6c8fea2 SE |
36 | |
37 | struct hashtable_t { | |
fb778ea1 ML |
38 | struct hlist_head *table; /* the hashtable itself with the buckets */ |
39 | spinlock_t *list_locks; /* spinlock for each hash list entry */ | |
c90681b8 | 40 | uint32_t size; /* size of hashtable */ |
c6c8fea2 SE |
41 | }; |
42 | ||
43 | /* allocates and clears the hash */ | |
1a8eaf07 | 44 | struct hashtable_t *batadv_hash_new(uint32_t size); |
c6c8fea2 | 45 | |
5d52dad2 SE |
46 | /* set class key for all locks */ |
47 | void batadv_hash_set_lock_class(struct hashtable_t *hash, | |
48 | struct lock_class_key *key); | |
49 | ||
c6c8fea2 | 50 | /* free only the hashtable and the hash itself. */ |
1a8eaf07 | 51 | void batadv_hash_destroy(struct hashtable_t *hash); |
c6c8fea2 SE |
52 | |
53 | /* remove the hash structure. if hashdata_free_cb != NULL, this function will be | |
54 | * called to remove the elements inside of the hash. if you don't remove the | |
9cfc7bd6 SE |
55 | * elements, memory might be leaked. |
56 | */ | |
c0a55929 SE |
57 | static inline void batadv_hash_delete(struct hashtable_t *hash, |
58 | hashdata_free_cb free_cb, 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 | ||
9cfc7bd6 | 82 | /* hash_add - adds data to the hashtable |
1a1f37d9 AQ |
83 | * @hash: storage hash table |
84 | * @compare: callback to determine if 2 hash elements are identical | |
85 | * @choose: callback calculating the hash index | |
86 | * @data: data passed to the aforementioned callbacks as argument | |
87 | * @data_node: to be added element | |
88 | * | |
89 | * Returns 0 on success, 1 if the element already is in the hash | |
90 | * and -1 on error. | |
91 | */ | |
c0a55929 SE |
92 | static inline int batadv_hash_add(struct hashtable_t *hash, |
93 | hashdata_compare_cb compare, | |
94 | hashdata_choose_cb choose, | |
95 | const void *data, | |
96 | struct hlist_node *data_node) | |
c6c8fea2 | 97 | { |
c90681b8 AQ |
98 | uint32_t index; |
99 | int ret = -1; | |
c6c8fea2 | 100 | struct hlist_head *head; |
7aadf889 | 101 | struct hlist_node *node; |
fb778ea1 | 102 | spinlock_t *list_lock; /* spinlock to protect write access */ |
c6c8fea2 SE |
103 | |
104 | if (!hash) | |
1a1f37d9 | 105 | goto out; |
c6c8fea2 SE |
106 | |
107 | index = choose(data, hash->size); | |
108 | head = &hash->table[index]; | |
fb778ea1 | 109 | list_lock = &hash->list_locks[index]; |
c6c8fea2 | 110 | |
75c5a2e7 MS |
111 | spin_lock_bh(list_lock); |
112 | ||
113 | hlist_for_each(node, head) { | |
7aadf889 ML |
114 | if (!compare(node, data)) |
115 | continue; | |
116 | ||
1a1f37d9 | 117 | ret = 1; |
75c5a2e7 | 118 | goto unlock; |
c6c8fea2 SE |
119 | } |
120 | ||
121 | /* no duplicate found in list, add new element */ | |
7aadf889 | 122 | hlist_add_head_rcu(data_node, head); |
c6c8fea2 | 123 | |
1a1f37d9 | 124 | ret = 0; |
fb778ea1 | 125 | |
75c5a2e7 MS |
126 | unlock: |
127 | spin_unlock_bh(list_lock); | |
1a1f37d9 AQ |
128 | out: |
129 | return ret; | |
c6c8fea2 SE |
130 | } |
131 | ||
132 | /* removes data from hash, if found. returns pointer do data on success, so you | |
133 | * can remove the used structure yourself, or NULL on error . data could be the | |
134 | * structure you use with just the key filled, we just need the key for | |
9cfc7bd6 SE |
135 | * comparing. |
136 | */ | |
c0a55929 SE |
137 | static inline void *batadv_hash_remove(struct hashtable_t *hash, |
138 | hashdata_compare_cb compare, | |
139 | hashdata_choose_cb choose, void *data) | |
c6c8fea2 | 140 | { |
c90681b8 | 141 | uint32_t index; |
7aadf889 | 142 | struct hlist_node *node; |
c6c8fea2 | 143 | struct hlist_head *head; |
fb778ea1 | 144 | void *data_save = NULL; |
c6c8fea2 SE |
145 | |
146 | index = choose(data, hash->size); | |
147 | head = &hash->table[index]; | |
148 | ||
fb778ea1 | 149 | spin_lock_bh(&hash->list_locks[index]); |
7aadf889 ML |
150 | hlist_for_each(node, head) { |
151 | if (!compare(node, data)) | |
152 | continue; | |
153 | ||
154 | data_save = node; | |
155 | hlist_del_rcu(node); | |
156 | break; | |
c6c8fea2 | 157 | } |
fb778ea1 | 158 | spin_unlock_bh(&hash->list_locks[index]); |
c6c8fea2 | 159 | |
fb778ea1 | 160 | return data_save; |
c6c8fea2 SE |
161 | } |
162 | ||
c6c8fea2 | 163 | #endif /* _NET_BATMAN_ADV_HASH_H_ */ |