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>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 547b4e718115eea74087e28d7fa70aec619200db)
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/net/bridge/br_stp_bpdu.c b/net/bridge/br_stp_bpdu.c
index 81ae40b3f6550c70b01b8d88a5266e14647a2d11..108215b60dd974f060d7e7eb0c83a085c3780e2e 100644 (file)
--- a/net/bridge/br_stp_bpdu.c
+++ b/net/bridge/br_stp_bpdu.c
@@ -15,6 +15,7 @@
 #include <linux/netfilter_bridge.h>
 #include <linux/etherdevice.h>
 #include <linux/llc.h>
+#include <linux/pkt_sched.h>
 #include <net/net_namespace.h>
 #include <net/llc.h>
 #include <net/llc_pdu.h>
@@ -39,6 +40,7 @@ static void br_send_bpdu(struct net_bridge_port *p,
 
        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);