[PKT_SCHED]: vlan tag match

Provide a way to use tc filters on vlan tag even if tag is buried in
skb due to hardware acceleration.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/em_meta.c b/net/sched/em_meta.c
index a1e5619..9c2ec19 100644
--- a/net/sched/em_meta.c
+++ b/net/sched/em_meta.c
@@ -65,6 +65,7 @@
 #include <linux/string.h>
 #include <linux/skbuff.h>
 #include <linux/random.h>
+#include <linux/if_vlan.h>
 #include <linux/tc_ematch/tc_em_meta.h>
 #include <net/dst.h>
 #include <net/route.h>
@@ -170,6 +171,21 @@
 }
 
 /**************************************************************************
+ * vlan tag
+ **************************************************************************/
+
+META_COLLECTOR(int_vlan_tag)
+{
+	unsigned short tag;
+	if (vlan_get_tag(skb, &tag) < 0)
+		*err = -1;
+	else
+		dst->value = tag;
+}
+
+
+
+/**************************************************************************
  * skb attributes
  **************************************************************************/
 
@@ -520,6 +536,7 @@
 		[META_ID(SK_SNDTIMEO)]		= META_FUNC(int_sk_sndtimeo),
 		[META_ID(SK_SENDMSG_OFF)]	= META_FUNC(int_sk_sendmsg_off),
 		[META_ID(SK_WRITE_PENDING)]	= META_FUNC(int_sk_write_pend),
+		[META_ID(VLAN_TAG)]		= META_FUNC(int_vlan_tag),
 	}
 };