net: tc: helper functions to query action types

BugLink: http://bugs.launchpad.net/bugs/1562326

This is a helper function drivers can use to learn if the
action type is a drop action.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 3b01cf56)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

include/net/tc_act/tc_gact.h

@@ -2,6 +2,7 @@
 #define __NET_TC_GACT_H
 
 #include <net/act_api.h>
+#include <linux/tc_act/tc_gact.h>
 
 struct tcf_gact {
 	struct tcf_common	common;
@@ -15,4 +16,19 @@ struct tcf_gact {
 #define to_gact(a) \
 	container_of(a->priv, struct tcf_gact, common)
 
+#ifdef CONFIG_NET_CLS_ACT
+static inline bool is_tcf_gact_shot(const struct tc_action *a)
+{
+	struct tcf_gact *gact;
+
+	if (a->ops && a->ops->type != TCA_ACT_GACT)
+		return false;
+
+	gact = a->priv;
+	if (gact->tcf_action == TC_ACT_SHOT)
+		return true;
+
+	return false;
+}
+#endif
 #endif /* __NET_TC_GACT_H */