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 *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 */
choose_orig(const void * data,uint32_t size)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
orig_hash_find(struct bat_priv * bat_priv,const void * data)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