1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun /* Copyright (C) 2006-2020 B.A.T.M.A.N. contributors:
3*4882a593Smuzhiyun *
4*4882a593Smuzhiyun * Simon Wunderlich, Marek Lindner
5*4882a593Smuzhiyun */
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun #ifndef _NET_BATMAN_ADV_BITARRAY_H_
8*4882a593Smuzhiyun #define _NET_BATMAN_ADV_BITARRAY_H_
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include "main.h"
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun #include <linux/bitops.h>
13*4882a593Smuzhiyun #include <linux/compiler.h>
14*4882a593Smuzhiyun #include <linux/stddef.h>
15*4882a593Smuzhiyun #include <linux/types.h>
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun /**
18*4882a593Smuzhiyun * batadv_test_bit() - check if bit is set in the current window
19*4882a593Smuzhiyun *
20*4882a593Smuzhiyun * @seq_bits: pointer to the sequence number receive packet
21*4882a593Smuzhiyun * @last_seqno: latest sequence number in seq_bits
22*4882a593Smuzhiyun * @curr_seqno: sequence number to test for
23*4882a593Smuzhiyun *
24*4882a593Smuzhiyun * Return: true if the corresponding bit in the given seq_bits indicates true
25*4882a593Smuzhiyun * and curr_seqno is within range of last_seqno. Otherwise returns false.
26*4882a593Smuzhiyun */
batadv_test_bit(const unsigned long * seq_bits,u32 last_seqno,u32 curr_seqno)27*4882a593Smuzhiyun static inline bool batadv_test_bit(const unsigned long *seq_bits,
28*4882a593Smuzhiyun u32 last_seqno, u32 curr_seqno)
29*4882a593Smuzhiyun {
30*4882a593Smuzhiyun s32 diff;
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun diff = last_seqno - curr_seqno;
33*4882a593Smuzhiyun if (diff < 0 || diff >= BATADV_TQ_LOCAL_WINDOW_SIZE)
34*4882a593Smuzhiyun return false;
35*4882a593Smuzhiyun return test_bit(diff, seq_bits) != 0;
36*4882a593Smuzhiyun }
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun /**
39*4882a593Smuzhiyun * batadv_set_bit() - Turn corresponding bit on, so we can remember that we got
40*4882a593Smuzhiyun * the packet
41*4882a593Smuzhiyun * @seq_bits: bitmap of the packet receive window
42*4882a593Smuzhiyun * @n: relative sequence number of newly received packet
43*4882a593Smuzhiyun */
batadv_set_bit(unsigned long * seq_bits,s32 n)44*4882a593Smuzhiyun static inline void batadv_set_bit(unsigned long *seq_bits, s32 n)
45*4882a593Smuzhiyun {
46*4882a593Smuzhiyun /* if too old, just drop it */
47*4882a593Smuzhiyun if (n < 0 || n >= BATADV_TQ_LOCAL_WINDOW_SIZE)
48*4882a593Smuzhiyun return;
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun set_bit(n, seq_bits); /* turn the position on */
51*4882a593Smuzhiyun }
52*4882a593Smuzhiyun
53*4882a593Smuzhiyun bool batadv_bit_get_packet(void *priv, unsigned long *seq_bits,
54*4882a593Smuzhiyun s32 seq_num_diff, int set_mark);
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun #endif /* _NET_BATMAN_ADV_BITARRAY_H_ */
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