Commit 6a09dc38 authored by Linus Lüssing's avatar Linus Lüssing Committed by Luis Henriques

batman-adv: Make NC capability changes atomic

commit 4635469f upstream.

Bitwise OR/AND assignments in C aren't guaranteed to be atomic. One
OGM handler might undo the set/clear of a specific bit from another
handler run in between.

Fix this by using the atomic set_bit()/clear_bit()/test_bit() functions.

Fixes: 3f4841ff ("batman-adv: tvlv - add network coding container")
Signed-off-by: default avatarLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: default avatarMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: default avatarAntonio Quartulli <antonio@meshcoding.com>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
parent 9d8dc5c2
......@@ -15,6 +15,7 @@
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/bitops.h>
#include <linux/debugfs.h>
#include "main.h"
......@@ -105,9 +106,9 @@ static void batadv_nc_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
uint16_t tvlv_value_len)
{
if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_NC;
clear_bit(BATADV_ORIG_CAPA_HAS_NC, &orig->capabilities);
else
orig->capabilities |= BATADV_ORIG_CAPA_HAS_NC;
set_bit(BATADV_ORIG_CAPA_HAS_NC, &orig->capabilities);
}
/**
......@@ -871,7 +872,7 @@ void batadv_nc_update_nc_node(struct batadv_priv *bat_priv,
goto out;
/* check if orig node is network coding enabled */
if (!(orig_node->capabilities & BATADV_ORIG_CAPA_HAS_NC))
if (!test_bit(BATADV_ORIG_CAPA_HAS_NC, &orig_node->capabilities))
goto out;
/* accept ogms from 'good' neighbors and single hop neighbors */
......
......@@ -299,7 +299,7 @@ struct batadv_orig_node {
*/
enum batadv_orig_capabilities {
BATADV_ORIG_CAPA_HAS_DAT,
BATADV_ORIG_CAPA_HAS_NC = BIT(1),
BATADV_ORIG_CAPA_HAS_NC,
BATADV_ORIG_CAPA_HAS_TT = BIT(2),
BATADV_ORIG_CAPA_HAS_MCAST = BIT(3),
};
......
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