Made dialer configurable

request.go

@@ -153,8 +153,12 @@ func (s *Server) handleConnect(conn conn, req *Request) error {
 	}
 
 	// Attempt to connect
-	addr := net.TCPAddr{IP: req.realDestAddr.IP, Port: req.realDestAddr.Port}
-	target, err := net.DialTCP("tcp", nil, &addr)
+	addr := fmt.Sprintf("%v:%d", req.realDestAddr.IP, req.realDestAddr.Port)
+	dial := s.config.Dial
+	if dial == nil {
+		dial = net.Dial
+	}
+	target, err := dial("tcp", addr)
 	if err != nil {
 		msg := err.Error()
 		resp := hostUnreachable

socks5.go

@@ -43,6 +43,9 @@ type Config struct {
 	// Logger can be used to provide a custom log target.
 	// Defaults to stdout.
 	Logger *log.Logger
+
+	// Optional function for dialing out
+	Dial func(network, addr string) (net.Conn, error)
 }
 
 // Server is reponsible for accepting connections and handling