/*

   * 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_ */