net/batman-adv/originator.h

   1 /* Copyright (C) 2007-2013 B.A.T.M.A.N. contributors:
   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, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #ifndef _NET_BATMAN_ADV_ORIGINATOR_H_
  19 #define _NET_BATMAN_ADV_ORIGINATOR_H_
  20
  21 #include "hash.h"
  22
  23 int batadv_compare_orig(const struct hlist_node *node, const void *data2);
  24 int batadv_originator_init(struct batadv_priv *bat_priv);
  25 void batadv_originator_free(struct batadv_priv *bat_priv);
  26 void batadv_purge_orig_ref(struct batadv_priv *bat_priv);
  27 void batadv_orig_node_free_ref(struct batadv_orig_node *orig_node);
  28 void batadv_orig_node_free_ref_now(struct batadv_orig_node *orig_node);
  29 struct batadv_orig_node *batadv_orig_node_new(struct batadv_priv *bat_priv,
  30                                               const uint8_t *addr);
  31 struct batadv_neigh_node *
  32 batadv_neigh_node_new(struct batadv_hard_iface *hard_iface,
  33                       const uint8_t *neigh_addr,
  34                       struct batadv_orig_node *orig_node);
  35 void batadv_neigh_node_free_ref(struct batadv_neigh_node *neigh_node);
  36 struct batadv_neigh_node *
  37 batadv_orig_node_get_router(struct batadv_orig_node *orig_node);
  38 int batadv_orig_seq_print_text(struct seq_file *seq, void *offset);
  39 int batadv_orig_hash_add_if(struct batadv_hard_iface *hard_iface,
  40                             int max_if_num);
  41 int batadv_orig_hash_del_if(struct batadv_hard_iface *hard_iface,
  42                             int max_if_num);
  43 struct batadv_orig_node_vlan *
  44 batadv_orig_node_vlan_new(struct batadv_orig_node *orig_node,
  45                           unsigned short vid);
  46 struct batadv_orig_node_vlan *
  47 batadv_orig_node_vlan_get(struct batadv_orig_node *orig_node,
  48                           unsigned short vid);
  49 void batadv_orig_node_vlan_free_ref(struct batadv_orig_node_vlan *orig_vlan);
  50
  51
  52 /* hashfunction to choose an entry in a hash table of given size
  53  * hash algorithm from http://en.wikipedia.org/wiki/Hash_table
  54  */
  55 static inline uint32_t batadv_choose_orig(const void *data, uint32_t size)
  56 {
  57         const unsigned char *key = data;
  58         uint32_t hash = 0;
  59         size_t i;
  60
  61         for (i = 0; i < 6; i++) {
  62                 hash += key[i];
  63                 hash += (hash << 10);
  64                 hash ^= (hash >> 6);
  65         }
  66
  67         hash += (hash << 3);
  68         hash ^= (hash >> 11);
  69         hash += (hash << 15);
  70
  71         return hash % size;
  72 }
  73
  74 static inline struct batadv_orig_node *
  75 batadv_orig_hash_find(struct batadv_priv *bat_priv, const void *data)
  76 {
  77         struct batadv_hashtable *hash = bat_priv->orig_hash;
  78         struct hlist_head *head;
  79         struct batadv_orig_node *orig_node, *orig_node_tmp = NULL;
  80         int index;
  81
  82         if (!hash)
  83                 return NULL;
  84
  85         index = batadv_choose_orig(data, hash->size);
  86         head = &hash->table[index];
  87
  88         rcu_read_lock();
  89         hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
  90                 if (!batadv_compare_eth(orig_node, data))
  91                         continue;
  92
  93                 if (!atomic_inc_not_zero(&orig_node->refcount))
  94                         continue;
  95
  96                 orig_node_tmp = orig_node;
  97                 break;
  98         }
  99         rcu_read_unlock();
 100
 101         return orig_node_tmp;
 102 }
 103
 104 #endif /* _NET_BATMAN_ADV_ORIGINATOR_H_ */