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

   1/* Copyright (C) 2006-2015 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/types.h>
  26
  27/* Returns 1 if the corresponding bit in the given seq_bits indicates true
  28 * and curr_seqno is within range of last_seqno. Otherwise returns 0.
  29 */
  30static inline int batadv_test_bit(const unsigned long *seq_bits,
  31                                  uint32_t last_seqno, uint32_t curr_seqno)
  32{
  33        int32_t diff;
  34
  35        diff = last_seqno - curr_seqno;
  36        if (diff < 0 || diff >= BATADV_TQ_LOCAL_WINDOW_SIZE)
  37                return 0;
  38        return test_bit(diff, seq_bits) != 0;
  39}
  40
  41/* turn corresponding bit on, so we can remember that we got the packet */
  42static inline void batadv_set_bit(unsigned long *seq_bits, int32_t n)
  43{
  44        /* if too old, just drop it */
  45        if (n < 0 || n >= BATADV_TQ_LOCAL_WINDOW_SIZE)
  46                return;
  47
  48        set_bit(n, seq_bits); /* turn the position on */
  49}
  50
  51/* receive and process one packet, returns 1 if received seq_num is considered
  52 * new, 0 if old
  53 */
  54int batadv_bit_get_packet(void *priv, unsigned long *seq_bits,
  55                          int32_t seq_num_diff, int set_mark);
  56
  57#endif /* _NET_BATMAN_ADV_BITARRAY_H_ */
  58