xref: /openbmc/linux/net/batman-adv/bitarray.h (revision 275876e2)
1 /* Copyright (C) 2006-2014 B.A.T.M.A.N. contributors:
2  *
3  * Simon Wunderlich, Marek Lindner
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, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #ifndef _NET_BATMAN_ADV_BITARRAY_H_
19 #define _NET_BATMAN_ADV_BITARRAY_H_
20 
21 /* Returns 1 if the corresponding bit in the given seq_bits indicates true
22  * and curr_seqno is within range of last_seqno. Otherwise returns 0.
23  */
24 static inline int batadv_test_bit(const unsigned long *seq_bits,
25 				  uint32_t last_seqno, uint32_t curr_seqno)
26 {
27 	int32_t diff;
28 
29 	diff = last_seqno - curr_seqno;
30 	if (diff < 0 || diff >= BATADV_TQ_LOCAL_WINDOW_SIZE)
31 		return 0;
32 	else
33 		return test_bit(diff, seq_bits) != 0;
34 }
35 
36 /* turn corresponding bit on, so we can remember that we got the packet */
37 static inline void batadv_set_bit(unsigned long *seq_bits, int32_t n)
38 {
39 	/* if too old, just drop it */
40 	if (n < 0 || n >= BATADV_TQ_LOCAL_WINDOW_SIZE)
41 		return;
42 
43 	set_bit(n, seq_bits); /* turn the position on */
44 }
45 
46 /* receive and process one packet, returns 1 if received seq_num is considered
47  * new, 0 if old
48  */
49 int batadv_bit_get_packet(void *priv, unsigned long *seq_bits,
50 			  int32_t seq_num_diff, int set_mark);
51 
52 #endif /* _NET_BATMAN_ADV_BITARRAY_H_ */
53