linux/net/batman-adv/bitarray.c
Sven Eckelmann cfa55c6d47 batman-adv: Drop publication years from copyright info
The batman-adv source code was using the year of publication (to net-next)
as "last" year for the copyright statement. The whole source code mentioned
in the MAINTAINERS "BATMAN ADVANCED" section was handled as a single entity
regarding the publishing year.

This avoided having outdated (in sense of year information - not copyright
holder) publishing information inside several files. But since the simple
"update copyright year" commit (without other changes) in the file was not
well received in the upstream kernel, the option to not have a copyright
year (for initial and last publication) in the files are chosen instead.
More detailed information about the years can still be retrieved from the
SCM system.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Acked-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2021-02-06 09:22:10 +01:00

90 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) B.A.T.M.A.N. contributors:
*
* Simon Wunderlich, Marek Lindner
*/
#include "bitarray.h"
#include "main.h"
#include <linux/bitmap.h>
#include "log.h"
/* shift the packet array by n places. */
static void batadv_bitmap_shift_left(unsigned long *seq_bits, s32 n)
{
if (n <= 0 || n >= BATADV_TQ_LOCAL_WINDOW_SIZE)
return;
bitmap_shift_left(seq_bits, seq_bits, n, BATADV_TQ_LOCAL_WINDOW_SIZE);
}
/**
* batadv_bit_get_packet() - receive and process one packet within the sequence
* number window
* @priv: the bat priv with all the soft interface information
* @seq_bits: pointer to the sequence number receive packet
* @seq_num_diff: difference between the current/received sequence number and
* the last sequence number
* @set_mark: whether this packet should be marked in seq_bits
*
* Return: true if the window was moved (either new or very old),
* false if the window was not moved/shifted.
*/
bool batadv_bit_get_packet(void *priv, unsigned long *seq_bits,
s32 seq_num_diff, int set_mark)
{
struct batadv_priv *bat_priv = priv;
/* sequence number is slightly older. We already got a sequence number
* higher than this one, so we just mark it.
*/
if (seq_num_diff <= 0 && seq_num_diff > -BATADV_TQ_LOCAL_WINDOW_SIZE) {
if (set_mark)
batadv_set_bit(seq_bits, -seq_num_diff);
return false;
}
/* sequence number is slightly newer, so we shift the window and
* set the mark if required
*/
if (seq_num_diff > 0 && seq_num_diff < BATADV_TQ_LOCAL_WINDOW_SIZE) {
batadv_bitmap_shift_left(seq_bits, seq_num_diff);
if (set_mark)
batadv_set_bit(seq_bits, 0);
return true;
}
/* sequence number is much newer, probably missed a lot of packets */
if (seq_num_diff >= BATADV_TQ_LOCAL_WINDOW_SIZE &&
seq_num_diff < BATADV_EXPECTED_SEQNO_RANGE) {
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"We missed a lot of packets (%i) !\n",
seq_num_diff - 1);
bitmap_zero(seq_bits, BATADV_TQ_LOCAL_WINDOW_SIZE);
if (set_mark)
batadv_set_bit(seq_bits, 0);
return true;
}
/* received a much older packet. The other host either restarted
* or the old packet got delayed somewhere in the network. The
* packet should be dropped without calling this function if the
* seqno window is protected.
*
* seq_num_diff <= -BATADV_TQ_LOCAL_WINDOW_SIZE
* or
* seq_num_diff >= BATADV_EXPECTED_SEQNO_RANGE
*/
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"Other host probably restarted!\n");
bitmap_zero(seq_bits, BATADV_TQ_LOCAL_WINDOW_SIZE);
if (set_mark)
batadv_set_bit(seq_bits, 0);
return true;
}