[mirror_ubuntu-artful-kernel.git] / net / batman-adv / originator.h

/* Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
 *
 * Marek Lindner, Simon Wunderlich
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA
 */

#ifndef _NET_BATMAN_ADV_ORIGINATOR_H_
#define _NET_BATMAN_ADV_ORIGINATOR_H_

#include "hash.h"

int batadv_originator_init(struct bat_priv *bat_priv);
void batadv_originator_free(struct bat_priv *bat_priv);
void batadv_purge_orig_ref(struct bat_priv *bat_priv);
void batadv_orig_node_free_ref(struct orig_node *orig_node);
struct orig_node *batadv_get_orig_node(struct bat_priv *bat_priv,
				       const uint8_t *addr);
struct neigh_node *batadv_neigh_node_new(struct hard_iface *hard_iface,
					 const uint8_t *neigh_addr,
					 uint32_t seqno);
void batadv_neigh_node_free_ref(struct neigh_node *neigh_node);
struct neigh_node *batadv_orig_node_get_router(struct orig_node *orig_node);
int batadv_orig_seq_print_text(struct seq_file *seq, void *offset);
int batadv_orig_hash_add_if(struct hard_iface *hard_iface, int max_if_num);
int batadv_orig_hash_del_if(struct hard_iface *hard_iface, int max_if_num);


/* hashfunction to choose an entry in a hash table of given size
 * hash algorithm from http://en.wikipedia.org/wiki/Hash_table
 */
static inline uint32_t batadv_choose_orig(const void *data, uint32_t size)
{
	const unsigned char *key = data;
	uint32_t hash = 0;
	size_t i;

	for (i = 0; i < 6; i++) {
		hash += key[i];
		hash += (hash << 10);
		hash ^= (hash >> 6);
	}

	hash += (hash << 3);
	hash ^= (hash >> 11);
	hash += (hash << 15);

	return hash % size;
}

static inline struct orig_node *batadv_orig_hash_find(struct bat_priv *bat_priv,
						      const void *data)
{
	struct hashtable_t *hash = bat_priv->orig_hash;
	struct hlist_head *head;
	struct hlist_node *node;
	struct orig_node *orig_node, *orig_node_tmp = NULL;
	int index;

	if (!hash)
		return NULL;

	index = batadv_choose_orig(data, hash->size);
	head = &hash->table[index];

	rcu_read_lock();
	hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
		if (!batadv_compare_eth(orig_node, data))
			continue;

		if (!atomic_inc_not_zero(&orig_node->refcount))
			continue;

		orig_node_tmp = orig_node;
		break;
	}
	rcu_read_unlock();

	return orig_node_tmp;
}

#endif /* _NET_BATMAN_ADV_ORIGINATOR_H_ */
Commit	Line	Data
9cfc7bd6	1	/* Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
c6c8fea2 SE	2	*
	3	* Marek Lindner, Simon Wunderlich
	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_ORIGINATOR_H_
	21	#define _NET_BATMAN_ADV_ORIGINATOR_H_
	22
7aadf889 ML	23	#include "hash.h"
7aadf889 ML	24
7d211efc SE	25	int batadv_originator_init(struct bat_priv *bat_priv);
	26	void batadv_originator_free(struct bat_priv *bat_priv);
	27	void batadv_purge_orig_ref(struct bat_priv *bat_priv);
	28	void batadv_orig_node_free_ref(struct orig_node *orig_node);
	29	struct orig_node batadv_get_orig_node(struct bat_priv bat_priv,
	30	const uint8_t *addr);
7ae8b285 ML	31	struct neigh_node batadv_neigh_node_new(struct hard_iface hard_iface,
	32	const uint8_t *neigh_addr,
	33	uint32_t seqno);
7d211efc SE	34	void batadv_neigh_node_free_ref(struct neigh_node *neigh_node);
	35	struct neigh_node batadv_orig_node_get_router(struct orig_node orig_node);
	36	int batadv_orig_seq_print_text(struct seq_file seq, void offset);
	37	int batadv_orig_hash_add_if(struct hard_iface *hard_iface, int max_if_num);
	38	int batadv_orig_hash_del_if(struct hard_iface *hard_iface, int max_if_num);
c6c8fea2 SE	39
c6c8fea2 SE	40
9cfc7bd6 SE	41	/* hashfunction to choose an entry in a hash table of given size
	42	* hash algorithm from http://en.wikipedia.org/wiki/Hash_table
	43	*/
da641193	44	static inline uint32_t batadv_choose_orig(const void *data, uint32_t size)
c6c8fea2	45	{
747e4221	46	const unsigned char *key = data;
c6c8fea2 SE	47	uint32_t hash = 0;
	48	size_t i;
	49
	50	for (i = 0; i < 6; i++) {
	51	hash += key[i];
	52	hash += (hash << 10);
	53	hash ^= (hash >> 6);
	54	}
	55
	56	hash += (hash << 3);
	57	hash ^= (hash >> 11);
	58	hash += (hash << 15);
	59
	60	return hash % size;
	61	}
	62
da641193 SE	63	static inline struct orig_node batadv_orig_hash_find(struct bat_priv bat_priv,
da641193 SE	64	const void *data)
7aadf889 ML	65	{
	66	struct hashtable_t *hash = bat_priv->orig_hash;
	67	struct hlist_head *head;
	68	struct hlist_node *node;
	69	struct orig_node orig_node, orig_node_tmp = NULL;
	70	int index;
	71
	72	if (!hash)
	73	return NULL;
	74
da641193	75	index = batadv_choose_orig(data, hash->size);
7aadf889 ML	76	head = &hash->table[index];
	77
	78	rcu_read_lock();
	79	hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
1eda58bf	80	if (!batadv_compare_eth(orig_node, data))
7aadf889 ML	81	continue;
7aadf889 ML	82
7b36e8ee ML	83	if (!atomic_inc_not_zero(&orig_node->refcount))
	84	continue;
	85
7aadf889	86	orig_node_tmp = orig_node;
7aadf889 ML	87	break;
	88	}
	89	rcu_read_unlock();
	90
	91	return orig_node_tmp;
	92	}
	93
c6c8fea2	94	#endif /* _NET_BATMAN_ADV_ORIGINATOR_H_ */