net/batman-adv/bitarray.h

   1 /* Copyright (C) 2006-2014 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 /* Returns 1 if the corresponding bit in the given seq_bits indicates true
  22  * and curr_seqno is within range of last_seqno. Otherwise returns 0.
  23  */
  24 static inline int batadv_test_bit(const unsigned long *seq_bits,
  25                                   uint32_t last_seqno, uint32_t curr_seqno)
  26 {
  27         int32_t diff;
  28
  29         diff = last_seqno - curr_seqno;
  30         if (diff < 0 || diff >= BATADV_TQ_LOCAL_WINDOW_SIZE)
  31                 return 0;
  32         else
  33                 return test_bit(diff, seq_bits) != 0;
  34 }
  35
  36 /* turn corresponding bit on, so we can remember that we got the packet */
  37 static inline void batadv_set_bit(unsigned long *seq_bits, int32_t n)
  38 {
  39         /* if too old, just drop it */
  40         if (n < 0 || n >= BATADV_TQ_LOCAL_WINDOW_SIZE)
  41                 return;
  42
  43         set_bit(n, seq_bits); /* turn the position on */
  44 }
  45
  46 /* receive and process one packet, returns 1 if received seq_num is considered
  47  * new, 0 if old
  48  */
  49 int batadv_bit_get_packet(void *priv, unsigned long *seq_bits,
  50                           int32_t seq_num_diff, int set_mark);
  51
  52 #endif /* _NET_BATMAN_ADV_BITARRAY_H_ */