add network feature for relay

handler/serial/metadata.go

@@ -0,0 +1,22 @@
+package serial
+
+import (
+	"time"
+
+	mdata "github.com/go-gost/core/metadata"
+	mdutil "github.com/go-gost/core/metadata/util"
+)
+
+const (
+	defaultPort     = "COM1"
+	defaultBaudRate = 9600
+)
+
+type metadata struct {
+	timeout time.Duration
+}
+
+func (h *serialHandler) parseMetadata(md mdata.Metadata) (err error) {
+	h.md.timeout = mdutil.GetDuration(md, "timeout", "serial.timeout", "handler.serial.timeout")
+	return
+}