[PATCH] bridge: set priority of STP packets

Spanning Tree Protocol packets should have always been marked as
control packets, this causes them to get queued in the high prirority
FIFO. As Radia Perlman mentioned in her LCA talk, STP dies if bridge
gets overloaded and can't communicate. This is a long-standing bug back
to the first versions of Linux bridge.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

---
Please consider adding to  stable as well.

--- a/net/bridge/br_stp_bpdu.c	2013-01-16 09:47:00.599539375 -0800
+++ b/net/bridge/br_stp_bpdu.c	2013-02-11 08:13:56.315979316 -0800

@@ -16,6 +16,7 @@
 #include <linux/etherdevice.h>
 #include <linux/llc.h>
 #include <linux/slab.h>
+#include <linux/pkt_sched.h>
 #include <net/net_namespace.h>
 #include <net/llc.h>
 #include <net/llc_pdu.h>

@@ -40,6 +41,7 @@ static void br_send_bpdu(struct net_brid
 
 	skb->dev = p->dev;
 	skb->protocol = htons(ETH_P_802_2);
+	skb->priority = TC_PRIO_CONTROL;
 
 	skb_reserve(skb, LLC_RESERVE);
 	memcpy(__skb_put(skb, length), data, length);

From: Stephen Hemminger <stephen@networkplumber.org>
Date: Mon, 11 Feb 2013 10:22:22 -0800

Spanning Tree Protocol packets should have always been marked as
control packets, this causes them to get queued in the high prirority
FIFO. As Radia Perlman mentioned in her LCA talk, STP dies if bridge
gets overloaded and can't communicate. This is a long-standing bug back
to the first versions of Linux bridge.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

Applied and queued up for -stable, thanks.

On Mon, 2013-02-11 at 10:22 -0800, Stephen Hemminger wrote:

I wonder if we should not use the same for ARP packets, as some bonding
modes depend on them as well.