xref: /openbmc/linux/net/batman-adv/originator.h (revision 77d84ff8)
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_compare_orig(const struct hlist_node *node, const void *data2);
26 int batadv_originator_init(struct batadv_priv *bat_priv);
27 void batadv_originator_free(struct batadv_priv *bat_priv);
28 void batadv_purge_orig_ref(struct batadv_priv *bat_priv);
29 void batadv_orig_node_free_ref(struct batadv_orig_node *orig_node);
30 void batadv_orig_node_free_ref_now(struct batadv_orig_node *orig_node);
31 struct batadv_orig_node *batadv_orig_node_new(struct batadv_priv *bat_priv,
32 					      const uint8_t *addr);
33 struct batadv_neigh_node *
34 batadv_neigh_node_new(struct batadv_hard_iface *hard_iface,
35 		      const uint8_t *neigh_addr,
36 		      struct batadv_orig_node *orig_node);
37 void batadv_neigh_node_free_ref(struct batadv_neigh_node *neigh_node);
38 struct batadv_neigh_node *
39 batadv_orig_node_get_router(struct batadv_orig_node *orig_node);
40 int batadv_orig_seq_print_text(struct seq_file *seq, void *offset);
41 int batadv_orig_hash_add_if(struct batadv_hard_iface *hard_iface,
42 			    int max_if_num);
43 int batadv_orig_hash_del_if(struct batadv_hard_iface *hard_iface,
44 			    int max_if_num);
45 struct batadv_orig_node_vlan *
46 batadv_orig_node_vlan_new(struct batadv_orig_node *orig_node,
47 			  unsigned short vid);
48 struct batadv_orig_node_vlan *
49 batadv_orig_node_vlan_get(struct batadv_orig_node *orig_node,
50 			  unsigned short vid);
51 void batadv_orig_node_vlan_free_ref(struct batadv_orig_node_vlan *orig_vlan);
52 
53 
54 /* hashfunction to choose an entry in a hash table of given size
55  * hash algorithm from http://en.wikipedia.org/wiki/Hash_table
56  */
57 static inline uint32_t batadv_choose_orig(const void *data, uint32_t size)
58 {
59 	const unsigned char *key = data;
60 	uint32_t hash = 0;
61 	size_t i;
62 
63 	for (i = 0; i < 6; i++) {
64 		hash += key[i];
65 		hash += (hash << 10);
66 		hash ^= (hash >> 6);
67 	}
68 
69 	hash += (hash << 3);
70 	hash ^= (hash >> 11);
71 	hash += (hash << 15);
72 
73 	return hash % size;
74 }
75 
76 static inline struct batadv_orig_node *
77 batadv_orig_hash_find(struct batadv_priv *bat_priv, const void *data)
78 {
79 	struct batadv_hashtable *hash = bat_priv->orig_hash;
80 	struct hlist_head *head;
81 	struct batadv_orig_node *orig_node, *orig_node_tmp = NULL;
82 	int index;
83 
84 	if (!hash)
85 		return NULL;
86 
87 	index = batadv_choose_orig(data, hash->size);
88 	head = &hash->table[index];
89 
90 	rcu_read_lock();
91 	hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
92 		if (!batadv_compare_eth(orig_node, data))
93 			continue;
94 
95 		if (!atomic_inc_not_zero(&orig_node->refcount))
96 			continue;
97 
98 		orig_node_tmp = orig_node;
99 		break;
100 	}
101 	rcu_read_unlock();
102 
103 	return orig_node_tmp;
104 }
105 
106 #endif /* _NET_BATMAN_ADV_ORIGINATOR_H_ */
107