net/batman-adv/originator.h

   1 /*
   2  * Copyright (C) 2007-2011 B.A.T.M.A.N. contributors:
   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
  25 int originator_init(struct bat_priv *bat_priv);
  26 void originator_free(struct bat_priv *bat_priv);
  27 void purge_orig_ref(struct bat_priv *bat_priv);
  28 struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr);
  29 struct neigh_node *
  30 create_neighbor(struct orig_node *orig_node, struct orig_node *orig_neigh_node,
  31                 uint8_t *neigh, struct batman_if *if_incoming);
  32 int orig_seq_print_text(struct seq_file *seq, void *offset);
  33 int orig_hash_add_if(struct batman_if *batman_if, int max_if_num);
  34 int orig_hash_del_if(struct batman_if *batman_if, int max_if_num);
  35
  36
  37 /* returns 1 if they are the same originator */
  38 static inline int compare_orig(void *data1, void *data2)
  39 {
  40         return (memcmp(data1, data2, ETH_ALEN) == 0 ? 1 : 0);
  41 }
  42
  43 /* hashfunction to choose an entry in a hash table of given size */
  44 /* hash algorithm from http://en.wikipedia.org/wiki/Hash_table */
  45 static inline int choose_orig(void *data, int32_t size)
  46 {
  47         unsigned char *key = data;
  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
  64 #endif /* _NET_BATMAN_ADV_ORIGINATOR_H_ */