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[06/11] batman-adv: wait multiple periods before activating bla

Message ID 1352798139-19458-7-git-send-email-ordex@autistici.org
State Changes Requested, archived
Delegated to: David Miller
Headers show

Commit Message

Antonio Quartulli Nov. 13, 2012, 9:15 a.m. UTC 
From: Simon Wunderlich <simon.wunderlich@s2003.tu-chemnitz.de>

For some reasons (bridge forward delay, network device setup order, etc)
the initial bridge loop avoidance announcement packets may be lost. This
may lead to problems in finding other backbone gws, and therfore create
loops in the startup time.

Fix this by extending the waiting periods to 3 (define can be changed)
before allowing broadcast traffic.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
---
 net/batman-adv/bridge_loop_avoidance.c | 9 ++++++++-
 net/batman-adv/main.h                  | 1 +
 net/batman-adv/types.h                 | 1 +
 3 files changed, 10 insertions(+), 1 deletion(-)
diff mbox

Patch

diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c
index 77ee47e..415343f 100644
--- a/net/batman-adv/bridge_loop_avoidance.c
+++ b/net/batman-adv/bridge_loop_avoidance.c
@@ -390,6 +390,7 @@  batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, uint8_t *orig,
 	entry->crc = BATADV_BLA_CRC_INIT;
 	entry->bat_priv = bat_priv;
 	atomic_set(&entry->request_sent, 0);
+	atomic_set(&entry->wait_periods, 0);
 	memcpy(entry->orig, orig, ETH_ALEN);
 
 	/* one for the hash, one for returning */
@@ -419,6 +420,7 @@  batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, uint8_t *orig,
 
 		/* this will be decreased in the worker thread */
 		atomic_inc(&entry->request_sent);
+		atomic_set(&entry->wait_periods, BATADV_BLA_WAIT_PERIODS);
 		atomic_inc(&bat_priv->bla.num_requests);
 	}
 
@@ -1160,12 +1162,17 @@  static void batadv_bla_periodic_work(struct work_struct *work)
 			 * problems when we are not yet known as backbone gw
 			 * in the backbone.
 			 *
-			 * We can reset this now and allow traffic again.
+			 * We can reset this now after we waited some periods
+			 * to give bridge forward delays and bla group forming
+			 * some grace time.
 			 */
 
 			if (atomic_read(&backbone_gw->request_sent) == 0)
 				continue;
 
+			if (!atomic_dec_and_test(&backbone_gw->wait_periods))
+				continue;
+
 			atomic_dec(&backbone_gw->bat_priv->bla.num_requests);
 			atomic_set(&backbone_gw->request_sent, 0);
 		}
diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h
index 240c74f..8f149bb 100644
--- a/net/batman-adv/main.h
+++ b/net/batman-adv/main.h
@@ -95,6 +95,7 @@ 
 #define BATADV_BLA_PERIOD_LENGTH	10000	/* 10 seconds */
 #define BATADV_BLA_BACKBONE_TIMEOUT	(BATADV_BLA_PERIOD_LENGTH * 3)
 #define BATADV_BLA_CLAIM_TIMEOUT	(BATADV_BLA_PERIOD_LENGTH * 10)
+#define BATADV_BLA_WAIT_PERIODS		3
 
 #define BATADV_DUPLIST_SIZE		16
 #define BATADV_DUPLIST_TIMEOUT		500	/* 500 ms */
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index e8a1b18..fa09961 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -369,6 +369,7 @@  struct batadv_backbone_gw {
 	struct hlist_node hash_entry;
 	struct batadv_priv *bat_priv;
 	unsigned long lasttime;	/* last time we heard of this backbone gw */
+	atomic_t wait_periods;
 	atomic_t request_sent;
 	atomic_t refcount;
 	struct rcu_head rcu;