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, uint8_t *addr); 32 struct neigh_node *create_neighbor(struct orig_node *orig_node, 33 struct orig_node *orig_neigh_node, 34 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 /* returns 1 if they are the same originator */ 44 static inline int compare_orig(struct hlist_node *node, void *data2) 45 { 46 void *data1 = container_of(node, struct orig_node, hash_entry); 47 48 return (memcmp(data1, data2, ETH_ALEN) == 0 ? 1 : 0); 49 } 50 51 /* hashfunction to choose an entry in a hash table of given size */ 52 /* hash algorithm from http://en.wikipedia.org/wiki/Hash_table */ 53 static inline int choose_orig(void *data, int32_t size) 54 { 55 unsigned char *key = data; 56 uint32_t hash = 0; 57 size_t i; 58 59 for (i = 0; i < 6; i++) { 60 hash += key[i]; 61 hash += (hash << 10); 62 hash ^= (hash >> 6); 63 } 64 65 hash += (hash << 3); 66 hash ^= (hash >> 11); 67 hash += (hash << 15); 68 69 return hash % size; 70 } 71 72 static inline struct orig_node *orig_hash_find(struct bat_priv *bat_priv, 73 void *data) 74 { 75 struct hashtable_t *hash = bat_priv->orig_hash; 76 struct hlist_head *head; 77 struct hlist_node *node; 78 struct orig_node *orig_node, *orig_node_tmp = NULL; 79 int index; 80 81 if (!hash) 82 return NULL; 83 84 index = choose_orig(data, hash->size); 85 head = &hash->table[index]; 86 87 rcu_read_lock(); 88 hlist_for_each_entry_rcu(orig_node, node, head, hash_entry) { 89 if (!compare_eth(orig_node, data)) 90 continue; 91 92 if (!atomic_inc_not_zero(&orig_node->refcount)) 93 continue; 94 95 orig_node_tmp = orig_node; 96 break; 97 } 98 rcu_read_unlock(); 99 100 return orig_node_tmp; 101 } 102 103 #endif /* _NET_BATMAN_ADV_ORIGINATOR_H_ */ 104