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 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of version 2 of the GNU General Public
8 * License as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, see <http://www.gnu.org/licenses/>.
17 */
18
19 #ifndef _NET_BATMAN_ADV_BITARRAY_H_
20 #define _NET_BATMAN_ADV_BITARRAY_H_
21
22 #include "main.h"
23
24 #include <linux/bitops.h>
25 #include <linux/compiler.h>
26 #include <linux/stddef.h>
27 #include <linux/types.h>
28
29 /**
30 * batadv_test_bit() - check if bit is set in the current window
31 *
32 * @seq_bits: pointer to the sequence number receive packet
33 * @last_seqno: latest sequence number in seq_bits
34 * @curr_seqno: sequence number to test for
35 *
36 * Return: true if the corresponding bit in the given seq_bits indicates true
37 * and curr_seqno is within range of last_seqno. Otherwise returns false.
38 */
39 static inline bool batadv_test_bit(const unsigned long *seq_bits,
40 u32 last_seqno, u32 curr_seqno)
41 {
42 s32 diff;
43
44 diff = last_seqno - curr_seqno;
45 if (diff < 0 || diff >= BATADV_TQ_LOCAL_WINDOW_SIZE)
46 return false;
47 return test_bit(diff, seq_bits) != 0;
48 }
49
50 /**
51 * batadv_set_bit() - Turn corresponding bit on, so we can remember that we got
52 * the packet
53 * @seq_bits: bitmap of the packet receive window
54 * @n: relative sequence number of newly received packet
55 */
56 static inline void batadv_set_bit(unsigned long *seq_bits, s32 n)
57 {
58 /* if too old, just drop it */
59 if (n < 0 || n >= BATADV_TQ_LOCAL_WINDOW_SIZE)
60 return;
61
62 set_bit(n, seq_bits); /* turn the position on */
63 }
64
65 bool batadv_bit_get_packet(void *priv, unsigned long *seq_bits,
66 s32 seq_num_diff, int set_mark);
67
68 #endif /* _NET_BATMAN_ADV_BITARRAY_H_ */
69
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