[ 040/143] resubmit bridge: fix message_age_timer calculation

Willy Tarreau
2014-05-12T02:20:07Z

From: Chris Healy <cphealy@gmail.com>

[ Upstream commit 9a0620133ccce9dd35c00a96405c8d80938c2cc0 ]

This changes the message_age_timer calculation to use the BPDU's max age as
opposed to the local bridge's max age. This is in accordance with section
8.6.2.3.2 Step 2 of the 802.1D-1998 sprecification.

With the current implementation, when running with very large bridge
diameters, convergance will not always occur even if a root bridge is
configured to have a longer max age.

Tested successfully on bridge diameters of ~200.

Signed-off-by: Chris Healy <cphealy@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
net/bridge/br_stp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/bridge/br_stp.c b/net/bridge/br_stp.c
index c7d6bfc..a67e6ce 100644
--- a/net/bridge/br_stp.c
+++ b/net/bridge/br_stp.c
@@ -192,7 +192,7 @@ static inline void br_record_config_information(struct net_bridge_port *p,
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 */
--
1.7.12.2.21.g234cd45.dirty