net/batman-adv/bitarray.h

   1 /* Copyright (C) 2006-2013 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, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA
  18  */
  19
  20 #ifndef _NET_BATMAN_ADV_BITARRAY_H_
  21 #define _NET_BATMAN_ADV_BITARRAY_H_
  22
  23 /* Returns 1 if the corresponding bit in the given seq_bits indicates true
  24  * and curr_seqno is within range of last_seqno. Otherwise returns 0.
  25  */
  26 static inline int batadv_test_bit(const unsigned long *seq_bits,
  27                                   uint32_t last_seqno, uint32_t curr_seqno)
  28 {
  29         int32_t diff;
  30
  31         diff = last_seqno - curr_seqno;
  32         if (diff < 0 || diff >= BATADV_TQ_LOCAL_WINDOW_SIZE)
  33                 return 0;
  34         else
  35                 return test_bit(diff, seq_bits) != 0;
  36 }
  37
  38 /* turn corresponding bit on, so we can remember that we got the packet */
  39 static inline void batadv_set_bit(unsigned long *seq_bits, int32_t n)
  40 {
  41         /* if too old, just drop it */
  42         if (n < 0 || n >= BATADV_TQ_LOCAL_WINDOW_SIZE)
  43                 return;
  44
  45         set_bit(n, seq_bits); /* turn the position on */
  46 }
  47
  48 /* receive and process one packet, returns 1 if received seq_num is considered
  49  * new, 0 if old
  50  */
  51 int batadv_bit_get_packet(void *priv, unsigned long *seq_bits,
  52                           int32_t seq_num_diff, int set_mark);
  53
  54 #endif /* _NET_BATMAN_ADV_BITARRAY_H_ */