1 /* 2 * Copyright (C) 2007-2012 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 *batadv_neigh_node_new(struct hard_iface *hard_iface, 33 const uint8_t *neigh_addr, 34 uint32_t seqno); 35 void neigh_node_free_ref(struct neigh_node *neigh_node); 36 struct neigh_node *orig_node_get_router(struct orig_node *orig_node); 37 int orig_seq_print_text(struct seq_file *seq, void *offset); 38 int orig_hash_add_if(struct hard_iface *hard_iface, int max_if_num); 39 int orig_hash_del_if(struct hard_iface *hard_iface, int max_if_num); 40 41 42 /* hashfunction to choose an entry in a hash table of given size */ 43 /* hash algorithm from http://en.wikipedia.org/wiki/Hash_table */ 44 static inline uint32_t choose_orig(const void *data, uint32_t size) 45 { 46 const unsigned char *key = data; 47 uint32_t hash = 0; 48 size_t i; 49 50 for (i = 0; i < 6; i++) { 51 hash += key[i]; 52 hash += (hash << 10); 53 hash ^= (hash >> 6); 54 } 55 56 hash += (hash << 3); 57 hash ^= (hash >> 11); 58 hash += (hash << 15); 59 60 return hash % size; 61 } 62 63 static inline struct orig_node *orig_hash_find(struct bat_priv *bat_priv, 64 const void *data) 65 { 66 struct hashtable_t *hash = bat_priv->orig_hash; 67 struct hlist_head *head; 68 struct hlist_node *node; 69 struct orig_node *orig_node, *orig_node_tmp = NULL; 70 int index; 71 72 if (!hash) 73 return NULL; 74 75 index = choose_orig(data, hash->size); 76 head = &hash->table[index]; 77 78 rcu_read_lock(); 79 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) { 80 if (!compare_eth(orig_node, data)) 81 continue; 82 83 if (!atomic_inc_not_zero(&orig_node->refcount)) 84 continue; 85 86 orig_node_tmp = orig_node; 87 break; 88 } 89 rcu_read_unlock(); 90 91 return orig_node_tmp; 92 } 93 94 #endif /* _NET_BATMAN_ADV_ORIGINATOR_H_ */ 95