net/act_skbedit: Utility functions for mark action

Enable device drivers to query the action, if and only if is a mark
action and what value to use for marking.

Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Amir Vadai <amir@vadai.me>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/tc_act/tc_skbedit.h

@@ -20,6 +20,7 @@
 #define __NET_TC_SKBEDIT_H
 
 #include <net/act_api.h>
+#include <linux/tc_act/tc_skbedit.h>
 
 struct tcf_skbedit {
 	struct tcf_common	common;
@@ -32,4 +33,19 @@ struct tcf_skbedit {
 #define to_skbedit(a) \
 	container_of(a->priv, struct tcf_skbedit, common)
 
+/* Return true iff action is mark */
+static inline bool is_tcf_skbedit_mark(const struct tc_action *a)
+{
+#ifdef CONFIG_NET_CLS_ACT
+	if (a->ops && a->ops->type == TCA_ACT_SKBEDIT)
+		return to_skbedit(a)->flags == SKBEDIT_F_MARK;
+#endif
+	return false;
+}
+
+static inline u32 tcf_skbedit_mark(const struct tc_action *a)
+{
+	return to_skbedit(a)->mark;
+}
+
 #endif /* __NET_TC_SKBEDIT_H */