netfilter: ctnetlink: add NAT support for expectations

This patch adds the missing bits to create expectations that
are created in NAT setups.

include/linux/netfilter/nfnetlink_conntrack.h

@@ -174,10 +174,19 @@ enum ctattr_expect {
 	CTA_EXPECT_ZONE,
 	CTA_EXPECT_FLAGS,
 	CTA_EXPECT_CLASS,
+	CTA_EXPECT_NAT,
 	__CTA_EXPECT_MAX
 };
 #define CTA_EXPECT_MAX (__CTA_EXPECT_MAX - 1)
 
+enum ctattr_expect_nat {
+	CTA_EXPECT_NAT_UNSPEC,
+	CTA_EXPECT_NAT_DIR,
+	CTA_EXPECT_NAT_TUPLE,
+	__CTA_EXPECT_NAT_MAX
+};
+#define CTA_EXPECT_NAT_MAX (__CTA_EXPECT_NAT_MAX - 1)
+
 enum ctattr_help {
 	CTA_HELP_UNSPEC,
 	CTA_HELP_NAME,