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, write to the Free Software 16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 17 * 02110-1301, USA 18 */ 19 20 #ifndef _NET_BATMAN_ADV_ORIGINATOR_H_ 21 #define _NET_BATMAN_ADV_ORIGINATOR_H_ 22 23 #include "hash.h" 24 25 int batadv_originator_init(struct batadv_priv *bat_priv); 26 void batadv_originator_free(struct batadv_priv *bat_priv); 27 void batadv_purge_orig_ref(struct batadv_priv *bat_priv); 28 void batadv_orig_node_free_ref(struct batadv_orig_node *orig_node); 29 struct batadv_orig_node *batadv_get_orig_node(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, uint32_t seqno); 34 void batadv_neigh_node_free_ref(struct batadv_neigh_node *neigh_node); 35 struct batadv_neigh_node * 36 batadv_orig_node_get_router(struct batadv_orig_node *orig_node); 37 int batadv_orig_seq_print_text(struct seq_file *seq, void *offset); 38 int batadv_orig_hash_add_if(struct batadv_hard_iface *hard_iface, 39 int max_if_num); 40 int batadv_orig_hash_del_if(struct batadv_hard_iface *hard_iface, 41 int max_if_num); 42 43 44 /* hashfunction to choose an entry in a hash table of given size 45 * hash algorithm from http://en.wikipedia.org/wiki/Hash_table 46 */ 47 static inline uint32_t batadv_choose_orig(const void *data, uint32_t size) 48 { 49 const unsigned char *key = data; 50 uint32_t hash = 0; 51 size_t i; 52 53 for (i = 0; i < 6; i++) { 54 hash += key[i]; 55 hash += (hash << 10); 56 hash ^= (hash >> 6); 57 } 58 59 hash += (hash << 3); 60 hash ^= (hash >> 11); 61 hash += (hash << 15); 62 63 return hash % size; 64 } 65 66 static inline struct batadv_orig_node * 67 batadv_orig_hash_find(struct batadv_priv *bat_priv, const void *data) 68 { 69 struct batadv_hashtable *hash = bat_priv->orig_hash; 70 struct hlist_head *head; 71 struct batadv_orig_node *orig_node, *orig_node_tmp = NULL; 72 int index; 73 74 if (!hash) 75 return NULL; 76 77 index = batadv_choose_orig(data, hash->size); 78 head = &hash->table[index]; 79 80 rcu_read_lock(); 81 hlist_for_each_entry_rcu(orig_node, head, hash_entry) { 82 if (!batadv_compare_eth(orig_node, data)) 83 continue; 84 85 if (!atomic_inc_not_zero(&orig_node->refcount)) 86 continue; 87 88 orig_node_tmp = orig_node; 89 break; 90 } 91 rcu_read_unlock(); 92 93 return orig_node_tmp; 94 } 95 96 #endif /* _NET_BATMAN_ADV_ORIGINATOR_H_ */ 97