linux/net/batman-adv/bitarray.h
Linus Lüssing dbd6b11e15 batman-adv: make batadv_test_bit() return 0 or 1 only
On some architectures test_bit() can return other values than 0 or 1:

With a generic x86 OpenWrt image in a kvm setup (batadv_)test_bit()
frequently returns -1 for me, leading to batadv_iv_ogm_update_seqnos()
wrongly signaling a protected seqno window.

This patch tries to fix this issue by making batadv_test_bit() return 0
or 1 only.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Acked-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-19 15:49:53 -04:00

54 lines
1.8 KiB
C

/* Copyright (C) 2006-2012 B.A.T.M.A.N. contributors:
*
* Simon Wunderlich, Marek Lindner
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA
*/
#ifndef _NET_BATMAN_ADV_BITARRAY_H_
#define _NET_BATMAN_ADV_BITARRAY_H_
/* Returns 1 if the corresponding bit in the given seq_bits indicates true
* and curr_seqno is within range of last_seqno. Otherwise returns 0.
*/
static inline int batadv_test_bit(const unsigned long *seq_bits,
uint32_t last_seqno, uint32_t curr_seqno)
{
int32_t diff;
diff = last_seqno - curr_seqno;
if (diff < 0 || diff >= BATADV_TQ_LOCAL_WINDOW_SIZE)
return 0;
else
return test_bit(diff, seq_bits) != 0;
}
/* turn corresponding bit on, so we can remember that we got the packet */
static inline void batadv_set_bit(unsigned long *seq_bits, int32_t n)
{
/* if too old, just drop it */
if (n < 0 || n >= BATADV_TQ_LOCAL_WINDOW_SIZE)
return;
set_bit(n, seq_bits); /* turn the position on */
}
/* receive and process one packet, returns 1 if received seq_num is considered
* new, 0 if old
*/
int batadv_bit_get_packet(void *priv, unsigned long *seq_bits,
int32_t seq_num_diff, int set_mark);
#endif /* _NET_BATMAN_ADV_BITARRAY_H_ */