LXR linux/net/batman-adv/bitarray.h

   1/* Copyright (C) 2006-2017  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#include "main.h"
  22
  23#include <linux/bitops.h>
  24#include <linux/compiler.h>
  25#include <linux/stddef.h>
  26#include <linux/types.h>
  27
  28/**
  29 * batadv_test_bit - check if bit is set in the current window
  30 *
  31 * @seq_bits: pointer to the sequence number receive packet
  32 * @last_seqno: latest sequence number in seq_bits
  33 * @curr_seqno: sequence number to test for
  34 *
  35 * Return: true if the corresponding bit in the given seq_bits indicates true
  36 * and curr_seqno is within range of last_seqno. Otherwise returns false.
  37 */
  38static inline bool batadv_test_bit(const unsigned long *seq_bits,
  39                                   u32 last_seqno, u32 curr_seqno)
  40{
  41        s32 diff;
  42
  43        diff = last_seqno - curr_seqno;
  44        if (diff < 0 || diff >= BATADV_TQ_LOCAL_WINDOW_SIZE)
  45                return false;
  46        return test_bit(diff, seq_bits) != 0;
  47}
  48
  49/* turn corresponding bit on, so we can remember that we got the packet */
  50static inline void batadv_set_bit(unsigned long *seq_bits, s32 n)
  51{
  52        /* if too old, just drop it */
  53        if (n < 0 || n >= BATADV_TQ_LOCAL_WINDOW_SIZE)
  54                return;
  55
  56        set_bit(n, seq_bits); /* turn the position on */
  57}
  58
  59bool batadv_bit_get_packet(void *priv, unsigned long *seq_bits,
  60                           s32 seq_num_diff, int set_mark);
  61
  62#endif /* _NET_BATMAN_ADV_BITARRAY_H_ */
  63