xref: /linux/net/batman-adv/bitarray.h (revision 3d0fe49454652117522f60bfbefb978ba0e5300b)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* Copyright (C) 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_ */
57