149 lines
3.9 KiB
C
149 lines
3.9 KiB
C
/* Copyright (C) 2006-2016 B.A.T.M.A.N. contributors:
|
|
*
|
|
* Simon Wunderlich, Marek Lindner
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of version 2 of the GNU General Public
|
|
* License as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#ifndef _NET_BATMAN_ADV_HASH_H_
|
|
#define _NET_BATMAN_ADV_HASH_H_
|
|
|
|
#include "main.h"
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/list.h>
|
|
#include <linux/rculist.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/stddef.h>
|
|
#include <linux/types.h>
|
|
|
|
struct lock_class_key;
|
|
|
|
/* callback to a compare function. should compare 2 element datas for their
|
|
* keys
|
|
*
|
|
* Return: true if same and false if not same
|
|
*/
|
|
typedef bool (*batadv_hashdata_compare_cb)(const struct hlist_node *,
|
|
const void *);
|
|
|
|
/* the hashfunction
|
|
*
|
|
* Return: an index based on the key in the data of the first argument and the
|
|
* size the second
|
|
*/
|
|
typedef u32 (*batadv_hashdata_choose_cb)(const void *, u32);
|
|
typedef void (*batadv_hashdata_free_cb)(struct hlist_node *, void *);
|
|
|
|
struct batadv_hashtable {
|
|
struct hlist_head *table; /* the hashtable itself with the buckets */
|
|
spinlock_t *list_locks; /* spinlock for each hash list entry */
|
|
u32 size; /* size of hashtable */
|
|
};
|
|
|
|
/* allocates and clears the hash */
|
|
struct batadv_hashtable *batadv_hash_new(u32 size);
|
|
|
|
/* set class key for all locks */
|
|
void batadv_hash_set_lock_class(struct batadv_hashtable *hash,
|
|
struct lock_class_key *key);
|
|
|
|
/* free only the hashtable and the hash itself. */
|
|
void batadv_hash_destroy(struct batadv_hashtable *hash);
|
|
|
|
/**
|
|
* batadv_hash_add - adds data to the hashtable
|
|
* @hash: storage hash table
|
|
* @compare: callback to determine if 2 hash elements are identical
|
|
* @choose: callback calculating the hash index
|
|
* @data: data passed to the aforementioned callbacks as argument
|
|
* @data_node: to be added element
|
|
*
|
|
* Return: 0 on success, 1 if the element already is in the hash
|
|
* and -1 on error.
|
|
*/
|
|
static inline int batadv_hash_add(struct batadv_hashtable *hash,
|
|
batadv_hashdata_compare_cb compare,
|
|
batadv_hashdata_choose_cb choose,
|
|
const void *data,
|
|
struct hlist_node *data_node)
|
|
{
|
|
u32 index;
|
|
int ret = -1;
|
|
struct hlist_head *head;
|
|
struct hlist_node *node;
|
|
spinlock_t *list_lock; /* spinlock to protect write access */
|
|
|
|
if (!hash)
|
|
goto out;
|
|
|
|
index = choose(data, hash->size);
|
|
head = &hash->table[index];
|
|
list_lock = &hash->list_locks[index];
|
|
|
|
spin_lock_bh(list_lock);
|
|
|
|
hlist_for_each(node, head) {
|
|
if (!compare(node, data))
|
|
continue;
|
|
|
|
ret = 1;
|
|
goto unlock;
|
|
}
|
|
|
|
/* no duplicate found in list, add new element */
|
|
hlist_add_head_rcu(data_node, head);
|
|
|
|
ret = 0;
|
|
|
|
unlock:
|
|
spin_unlock_bh(list_lock);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/* removes data from hash, if found. data could be the structure you use with
|
|
* just the key filled, we just need the key for comparing.
|
|
*
|
|
* Return: returns pointer do data on success, so you can remove the used
|
|
* structure yourself, or NULL on error
|
|
*/
|
|
static inline void *batadv_hash_remove(struct batadv_hashtable *hash,
|
|
batadv_hashdata_compare_cb compare,
|
|
batadv_hashdata_choose_cb choose,
|
|
void *data)
|
|
{
|
|
u32 index;
|
|
struct hlist_node *node;
|
|
struct hlist_head *head;
|
|
void *data_save = NULL;
|
|
|
|
index = choose(data, hash->size);
|
|
head = &hash->table[index];
|
|
|
|
spin_lock_bh(&hash->list_locks[index]);
|
|
hlist_for_each(node, head) {
|
|
if (!compare(node, data))
|
|
continue;
|
|
|
|
data_save = node;
|
|
hlist_del_rcu(node);
|
|
break;
|
|
}
|
|
spin_unlock_bh(&hash->list_locks[index]);
|
|
|
|
return data_save;
|
|
}
|
|
|
|
#endif /* _NET_BATMAN_ADV_HASH_H_ */
|