1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* Copyright (C) 2006-2019 B.A.T.M.A.N. contributors:
3 *
4 * Simon Wunderlich, Marek Lindner
5 */
6
7 #ifndef _NET_BATMAN_ADV_BITARRAY_H_
8 #define _NET_BATMAN_ADV_BITARRAY_H_
9
10 #include "main.h"
11
12 #include <linux/bitops.h>
13 #include <linux/compiler.h>
14 #include <linux/stddef.h>
15 #include <linux/types.h>
16
17 /**
18 * batadv_test_bit() - check if bit is set in the current window
19 *
20 * @seq_bits: pointer to the sequence number receive packet
21 * @last_seqno: latest sequence number in seq_bits
22 * @curr_seqno: sequence number to test for
23 *
24 * Return: true if the corresponding bit in the given seq_bits indicates true
25 * and curr_seqno is within range of last_seqno. Otherwise returns false.
26 */
27 static inline bool batadv_test_bit(const unsigned long *seq_bits,
28 u32 last_seqno, u32 curr_seqno)
29 {
30 s32 diff;
31
32 diff = last_seqno - curr_seqno;
33 if (diff < 0 || diff >= BATADV_TQ_LOCAL_WINDOW_SIZE)
34 return false;
35 return test_bit(diff, seq_bits) != 0;
36 }
37
38 /**
39 * batadv_set_bit() - Turn corresponding bit on, so we can remember that we got
40 * the packet
41 * @seq_bits: bitmap of the packet receive window
42 * @n: relative sequence number of newly received packet
43 */
44 static inline void batadv_set_bit(unsigned long *seq_bits, s32 n)
45 {
46 /* if too old, just drop it */
47 if (n < 0 || n >= BATADV_TQ_LOCAL_WINDOW_SIZE)
48 return;
49
50 set_bit(n, seq_bits); /* turn the position on */
51 }
52
53 bool batadv_bit_get_packet(void *priv, unsigned long *seq_bits,
54 s32 seq_num_diff, int set_mark);
55
56 #endif /* _NET_BATMAN_ADV_BITARRAY_H_ */