batman-adv: wait multiple periods before activating bla

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>

batman-adv: wait multiple periods before activating bla
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>
Simon Wunderlich · Antonio Quartulli
1 parent d807f27287
Showing 3 changed files with 10 additions and 1 deletions Side-by-side Diff
net/batman-adv/bridge_loop_avoidance.c
net/batman-adv/main.h
net/batman-adv/types.h
@@ -378,6 +378,7 @@
 	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 */
@@ -407,6 +408,7 @@
  
 		/* 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);
 	}
  
  
@@ -1148,10 +1150,15 @@
 			 * 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);
@@ -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 */
@@ -369,6 +369,7 @@
 	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;
...	...	@@ -378,6 +378,7 @@
378	378	entry->crc = BATADV_BLA_CRC_INIT;
379	379	entry->bat_priv = bat_priv;
380	380	atomic_set(&entry->request_sent, 0);
	381	+ atomic_set(&entry->wait_periods, 0);
381	382	memcpy(entry->orig, orig, ETH_ALEN);
382	383
383	384	/* one for the hash, one for returning */
...	...	@@ -407,6 +408,7 @@
407	408
408	409	/* this will be decreased in the worker thread */
409	410	atomic_inc(&entry->request_sent);
	411	+ atomic_set(&entry->wait_periods, BATADV_BLA_WAIT_PERIODS);
410	412	atomic_inc(&bat_priv->bla.num_requests);
411	413	}
412	414
413	415
...	...	@@ -1148,10 +1150,15 @@
1148	1150	* problems when we are not yet known as backbone gw
1149	1151	* in the backbone.
1150	1152	*
1151		- * We can reset this now and allow traffic again.
	1153	+ * We can reset this now after we waited some periods
	1154	+ * to give bridge forward delays and bla group forming
	1155	+ * some grace time.
1152	1156	*/
1153	1157
1154	1158	if (atomic_read(&backbone_gw->request_sent) == 0)
	1159	+ continue;
	1160	+
	1161	+ if (!atomic_dec_and_test(&backbone_gw->wait_periods))
1155	1162	continue;
1156	1163
1157	1164	atomic_dec(&backbone_gw->bat_priv->bla.num_requests);
...	...	@@ -95,6 +95,7 @@
95	95	#define BATADV_BLA_PERIOD_LENGTH 10000 /* 10 seconds */
96	96	#define BATADV_BLA_BACKBONE_TIMEOUT (BATADV_BLA_PERIOD_LENGTH * 3)
97	97	#define BATADV_BLA_CLAIM_TIMEOUT (BATADV_BLA_PERIOD_LENGTH * 10)
	98	+#define BATADV_BLA_WAIT_PERIODS 3
98	99
99	100	#define BATADV_DUPLIST_SIZE 16
100	101	#define BATADV_DUPLIST_TIMEOUT 500 /* 500 ms */
...	...	@@ -369,6 +369,7 @@
369	369	struct hlist_node hash_entry;
370	370	struct batadv_priv *bat_priv;
371	371	unsigned long lasttime; /* last time we heard of this backbone gw */
	372	+ atomic_t wait_periods;
372	373	atomic_t request_sent;
373	374	atomic_t refcount;
374	375	struct rcu_head rcu;