dns: reduce Lua allocations with flat arguments and returns and native IP slice userdata

app/dns/script.go

@@ -39,7 +39,7 @@ func newScriptEngine(path string, server *DNS) (*scriptEngine, error) {
 		}
 		if L.GetGlobal("handleDNSQuery").Type() != lua.LTFunction {
 			L.Close()
-			return nil, errors.New("DNS script must define handleDNSQuery(q)")
+			return nil, errors.New("DNS script must define handleDNSQuery(domain, ipv4, ipv6, fake)")
 		}
 		return L, nil
 	})