fix redirect on non linux OS

redirect.go

-// +build !windows
+// +build linux
 
 package gost
 

redirect_win.go → redirect_other.go

-// +build windows
+// +build !linux
 
 package gost
 
 import (
+	"errors"
 	"net"
 
 	"github.com/go-log/log"
@@ -33,3 +34,24 @@ func (h *tcpRedirectHandler) Handle(c net.Conn) {
 	log.Log("[red-tcp] TCP redirect is not available on the Windows platform")
 	c.Close()
 }
+
+type udpRedirectHandler struct {
+}
+
+// UDPRedirectHandler creates a server Handler for UDP transparent server.
+func UDPRedirectHandler(opts ...HandlerOption) Handler {
+	return &udpRedirectHandler{}
+}
+
+func (h *udpRedirectHandler) Init(options ...HandlerOption) {
+}
+
+func (h *udpRedirectHandler) Handle(conn net.Conn) {
+	log.Log("[red-udp] UDP redirect is not available on the Windows platform")
+	conn.Close()
+}
+
+// UDPRedirectListener creates a Listener for UDP transparent proxy server.
+func UDPRedirectListener(addr string, cfg *UDPListenConfig) (Listener, error) {
+	return nil, errors.New("UDP redirect is not available on the Windows platform")
+}