diff options
author | Herbert Xu <herbert@gondor.apana.org.au> | 2013-09-12 17:12:05 +1000 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-10-13 14:51:07 -0700 |
commit | 20218d3d355cb32bdf1d737438958aa75f6ab21a (patch) | |
tree | 1877629259f8f8adf67036b5ab57dfe827336b72 /net/bridge/br_stp.c | |
parent | ae9f7cfdfc708c1c323e7e02e3ba067ddc96b671 (diff) |
bridge: Clamp forward_delay when enabling STP
[ Upstream commit be4f154d5ef0ca147ab6bcd38857a774133f5450 ]
At some point limits were added to forward_delay. However, the
limits are only enforced when STP is enabled. This created a
scenario where you could have a value outside the allowed range
while STP is disabled, which then stuck around even after STP
is enabled.
This patch fixes this by clamping the value when we enable STP.
I had to move the locking around a bit to ensure that there is
no window where someone could insert a value outside the range
while we're in the middle of enabling STP.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/bridge/br_stp.c')
-rw-r--r-- | net/bridge/br_stp.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/net/bridge/br_stp.c b/net/bridge/br_stp.c index 1b55122c0dcb..81fb35ac09a0 100644 --- a/net/bridge/br_stp.c +++ b/net/bridge/br_stp.c @@ -517,18 +517,27 @@ 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; } |