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authorHerbert Xu <herbert@gondor.apana.org.au>2013-09-12 17:12:05 +1000
committerDavid S. Miller <davem@davemloft.net>2013-09-12 23:32:14 -0400
commitbe4f154d5ef0ca147ab6bcd38857a774133f5450 (patch)
treea0d1f8c90c823bbecebaf30a02e2b5ad79c97944 /net/bridge/br_stp_if.c
parent9a0620133ccce9dd35c00a96405c8d80938c2cc0 (diff)
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bridge: Clamp forward_delay when enabling STP
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> Cheers, Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/bridge/br_stp_if.c')
-rw-r--r--net/bridge/br_stp_if.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
index d45e760141bb..108084a04671 100644
--- a/net/bridge/br_stp_if.c
+++ b/net/bridge/br_stp_if.c
@@ -129,6 +129,14 @@ static void br_stp_start(struct net_bridge *br)
char *envp[] = { NULL };
r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
+
+ spin_lock_bh(&br->lock);
+
+ if (br->bridge_forward_delay < BR_MIN_FORWARD_DELAY)
+ __br_set_forward_delay(br, BR_MIN_FORWARD_DELAY);
+ else if (br->bridge_forward_delay < BR_MAX_FORWARD_DELAY)
+ __br_set_forward_delay(br, BR_MAX_FORWARD_DELAY);
+
if (r == 0) {
br->stp_enabled = BR_USER_STP;
br_debug(br, "userspace STP started\n");
@@ -137,10 +145,10 @@ static void br_stp_start(struct net_bridge *br)
br_debug(br, "using kernel STP\n");
/* To start timers on any ports left in blocking */
- spin_lock_bh(&br->lock);
br_port_state_selection(br);
- spin_unlock_bh(&br->lock);
}
+
+ spin_unlock_bh(&br->lock);
}
static void br_stp_stop(struct net_bridge *br)