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

/*
 * Copyright (C) 2007-2011 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 originator_init(struct bat_priv *bat_priv);
void originator_free(struct bat_priv *bat_priv);
void purge_orig_ref(struct bat_priv *bat_priv);
void orig_node_free_ref(struct orig_node *orig_node);
struct orig_node *get_orig_node(struct bat_priv *bat_priv, const uint8_t *addr);
struct neigh_node *create_neighbor(struct orig_node *orig_node,
				   struct orig_node *orig_neigh_node,
				   const uint8_t *neigh,
				   struct hard_iface *if_incoming);
void neigh_node_free_ref(struct neigh_node *neigh_node);
struct neigh_node *orig_node_get_router(struct orig_node *orig_node);
int orig_seq_print_text(struct seq_file *seq, void *offset);
int orig_hash_add_if(struct hard_iface *hard_iface, int max_if_num);
int 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 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 *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 = choose_orig(data, hash->size);
	head = &hash->table[index];

	rcu_read_lock();
	hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
		if (!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
c6c8fea2	1	/*
64afe353	2	* Copyright (C) 2007-2011 B.A.T.M.A.N. contributors:
c6c8fea2 SE	3	*
	4	* Marek Lindner, Simon Wunderlich
	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_ORIGINATOR_H_
	23	#define _NET_BATMAN_ADV_ORIGINATOR_H_
	24
7aadf889 ML	25	#include "hash.h"
7aadf889 ML	26
c6c8fea2 SE	27	int originator_init(struct bat_priv *bat_priv);
	28	void originator_free(struct bat_priv *bat_priv);
	29	void purge_orig_ref(struct bat_priv *bat_priv);
7b36e8ee	30	void orig_node_free_ref(struct orig_node *orig_node);
747e4221	31	struct orig_node get_orig_node(struct bat_priv bat_priv, const uint8_t *addr);
a8e7f4bc ML	32	struct neigh_node create_neighbor(struct orig_node orig_node,
a8e7f4bc ML	33	struct orig_node *orig_neigh_node,
747e4221	34	const uint8_t *neigh,
e6c10f43	35	struct hard_iface *if_incoming);
44524fcd	36	void neigh_node_free_ref(struct neigh_node *neigh_node);
e1a5382f	37	struct neigh_node orig_node_get_router(struct orig_node orig_node);
c6c8fea2	38	int orig_seq_print_text(struct seq_file seq, void offset);
e6c10f43 ML	39	int orig_hash_add_if(struct hard_iface *hard_iface, int max_if_num);
e6c10f43 ML	40	int orig_hash_del_if(struct hard_iface *hard_iface, int max_if_num);
c6c8fea2 SE	41
c6c8fea2 SE	42
c6c8fea2 SE	43	/* hashfunction to choose an entry in a hash table of given size */
c6c8fea2 SE	44	/* hash algorithm from http://en.wikipedia.org/wiki/Hash_table */
c90681b8	45	static inline uint32_t choose_orig(const void *data, uint32_t size)
c6c8fea2	46	{
747e4221	47	const unsigned char *key = data;
c6c8fea2 SE	48	uint32_t hash = 0;
	49	size_t i;
	50
	51	for (i = 0; i < 6; i++) {
	52	hash += key[i];
	53	hash += (hash << 10);
	54	hash ^= (hash >> 6);
	55	}
	56
	57	hash += (hash << 3);
	58	hash ^= (hash >> 11);
	59	hash += (hash << 15);
	60
	61	return hash % size;
	62	}
	63
7aadf889	64	static inline struct orig_node orig_hash_find(struct bat_priv bat_priv,
747e4221	65	const void *data)
7aadf889 ML	66	{
	67	struct hashtable_t *hash = bat_priv->orig_hash;
	68	struct hlist_head *head;
	69	struct hlist_node *node;
	70	struct orig_node orig_node, orig_node_tmp = NULL;
	71	int index;
	72
	73	if (!hash)
	74	return NULL;
	75
	76	index = choose_orig(data, hash->size);
	77	head = &hash->table[index];
	78
	79	rcu_read_lock();
	80	hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) {
	81	if (!compare_eth(orig_node, data))
	82	continue;
	83
7b36e8ee ML	84	if (!atomic_inc_not_zero(&orig_node->refcount))
	85	continue;
	86
7aadf889	87	orig_node_tmp = orig_node;
7aadf889 ML	88	break;
	89	}
	90	rcu_read_unlock();
	91
	92	return orig_node_tmp;
	93	}
	94
c6c8fea2	95	#endif /* _NET_BATMAN_ADV_ORIGINATOR_H_ */