Move wanFirewallURNFix definition out to package.

cmd/goupnpdcpgen/metadata.go

@@ -124,4 +124,17 @@ func fixMissingURN(missingURNs ...string) func(dcp *DCP) error {
 	}
 }
 
+func wanFirewallURNFix(dcp *DCP) error {
+	missingURN := "urn:schemas-upnp-org:service:WANIPv6FirewallControl:1"
+	if _, ok := dcp.ServiceTypes[missingURN]; ok {
+		return nil
+	}
+	urnParts, err := extractURNParts(missingURN, serviceURNPrefix)
+	if err != nil {
+		return err
+	}
+	dcp.ServiceTypes[missingURN] = urnParts
+	return nil
+}
+
 type DCPHackFn func(*DCP) error