Refactor wireguard & add tun support

transport/wireguard/error.go

@@ -0,0 +1,22 @@
+package wireguard
+
+import "net"
+
+type wireError struct {
+	cause error
+}
+
+func (w *wireError) Error() string {
+	return w.cause.Error()
+}
+
+func (w *wireError) Timeout() bool {
+	if cause, causeNet := w.cause.(net.Error); causeNet {
+		return cause.Timeout()
+	}
+	return false
+}
+
+func (w *wireError) Temporary() bool {
+	return true
+}