1 files changed, 51 insertions, 15 deletions

diff --git a/net/bridge/br_stp.c b/net/bridge/br_stp.c
index dd147d78a58..3c86f0538cb 100644
--- a/net/bridge/br_stp.c
+++ b/net/bridge/br_stp.c
@@ -17,9 +17,9 @@
 #include "br_private_stp.h"
 
 /* since time values in bpdu are in jiffies and then scaled (1/256)
- * before sending, make sure that is at least one.
+ * before sending, make sure that is at least one STP tick.
  */
-#define MESSAGE_AGE_INCR	((HZ < 256) ? 1 : (HZ/256))
+#define MESSAGE_AGE_INCR	((HZ / 256) + 1)
 
 static const char *const br_port_state_names[] = {
 	[BR_STATE_DISABLED] = "disabled",
@@ -31,8 +31,8 @@ static const char *const br_port_state_names[] = {
 
 void br_log_state(const struct net_bridge_port *p)
 {
-	br_info(p->br, "port %u(%s) entering %s state\n",
-		(unsigned) p->port_no, p->dev->name,
+	br_info(p->br, "port %u(%s) entered %s state\n",
+		(unsigned int) p->port_no, p->dev->name,
 		br_port_state_names[p->state]);
 }
 
@@ -100,6 +100,21 @@ static int br_should_become_root_port(const struct net_bridge_port *p,
 	return 0;
 }
 
+static void br_root_port_block(const struct net_bridge *br,
+			       struct net_bridge_port *p)
+{
+
+	br_notice(br, "port %u(%s) tried to become root port (blocked)",
+		  (unsigned int) p->port_no, p->dev->name);
+
+	p->state = BR_STATE_LISTENING;
+	br_log_state(p);
+	br_ifinfo_notify(RTM_NEWLINK, p);
+
+	if (br->forward_delay > 0)
+		mod_timer(&p->forward_delay_timer, jiffies + br->forward_delay);
+}
+
 /* called under bridge lock */
 static void br_root_selection(struct net_bridge *br)
 {
@@ -107,7 +122,12 @@ static void br_root_selection(struct net_bridge *br)
 	u16 root_port = 0;
 
 	list_for_each_entry(p, &br->port_list, list) {
-		if (br_should_become_root_port(p, root_port))
+		if (!br_should_become_root_port(p, root_port))
+			continue;
+
+		if (p->flags & BR_ROOT_BLOCK)
+			br_root_port_block(br, p);
+		else
 			root_port = p->port_no;
 	}
 
@@ -186,10 +206,10 @@ static void br_record_config_information(struct net_bridge_port *p,
 	p->designated_cost = bpdu->root_path_cost;
 	p->designated_bridge = bpdu->bridge_id;
 	p->designated_port = bpdu->port_id;
-	p->designated_age = jiffies + bpdu->message_age;
+	p->designated_age = jiffies - bpdu->message_age;
 
 	mod_timer(&p->message_age_timer, jiffies
-		  + (p->br->max_age - bpdu->message_age));
+		  + (bpdu->max_age - bpdu->message_age));
 }
 
 /* called under bridge lock */
@@ -205,7 +225,14 @@ static void br_record_config_timeout_values(struct net_bridge *br,
 /* called under bridge lock */
 void br_transmit_tcn(struct net_bridge *br)
 {
-	br_send_tcn_bpdu(br_get_port(br, br->root_port));
+	struct net_bridge_port *p;
+
+	p = br_get_port(br, br->root_port);
+	if (p)
+		br_send_tcn_bpdu(p);
+	else
+		br_notice(br, "root port %u not found for topology notice\n",
+			  br->root_port);
 }
 
 /* called under bridge lock */
@@ -478,7 +505,7 @@ void br_received_tcn_bpdu(struct net_bridge_port *p)
 {
 	if (br_is_designated_port(p)) {
 		br_info(p->br, "port %u(%s) received tcn bpdu\n",
-			(unsigned) p->port_no, p->dev->name);
+			(unsigned int) p->port_no, p->dev->name);
 
 		br_topology_change_detection(p->br);
 		br_topology_change_acknowledge(p);
@@ -517,18 +544,27 @@ int br_set_max_age(struct net_bridge *br, unsigned long val)
 
 }
 
+void __br_set_forward_delay(struct net_bridge *br, unsigned long t)
+{
+	br->bridge_forward_delay = t;
+	if (br_is_root_bridge(br))
+		br->forward_delay = br->bridge_forward_delay;
+}
+
 int br_set_forward_delay(struct net_bridge *br, unsigned long val)
 {
 	unsigned long t = clock_t_to_jiffies(val);
+	int err = -ERANGE;
 
+	spin_lock_bh(&br->lock);
 	if (br->stp_enabled != BR_NO_STP &&
 	    (t < BR_MIN_FORWARD_DELAY || t > BR_MAX_FORWARD_DELAY))
-		return -ERANGE;
+		goto unlock;
 
-	spin_lock_bh(&br->lock);
-	br->bridge_forward_delay = t;
-	if (br_is_root_bridge(br))
-		br->forward_delay = br->bridge_forward_delay;
+	__br_set_forward_delay(br, t);
+	err = 0;
+
+unlock:
 	spin_unlock_bh(&br->lock);
-	return 0;
+	return err;
 }