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 #include "hash.h" 26 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); 30 void orig_node_free_ref(struct orig_node *orig_node); 31 struct orig_node *get_orig_node(struct bat_priv *bat_priv, const uint8_t *addr); 32 struct neigh_node *create_neighbor(struct orig_node *orig_node, 33 struct orig_node *orig_neigh_node, 34 const uint8_t *neigh, 35 struct hard_iface *if_incoming); 36 void neigh_node_free_ref(struct neigh_node *neigh_node); 37 struct neigh_node *orig_node_get_router(struct orig_node *orig_node); 38 int orig_seq_print_text(struct seq_file *seq, void *offset); 39 int orig_hash_add_if(struct hard_iface *hard_iface, int max_if_num); 40 int orig_hash_del_if(struct hard_iface *hard_iface, int max_if_num); 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 uint32_t choose_orig(const void *data, uint32_t size) 46 { 47 const 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 static inline struct orig_node *orig_hash_find(struct bat_priv *bat_priv, 65 const void *data) 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 84 if (!atomic_inc_not_zero(&orig_node->refcount)) 85 continue; 86 87 orig_node_tmp = orig_node; 88 break; 89 } 90 rcu_read_unlock(); 91 92 return orig_node_tmp; 93 } 94 95 #endif /* _NET_BATMAN_ADV_ORIGINATOR_H_ */ 96