Add early conn interface

transport/trojan/protocol.go

@@ -26,6 +26,8 @@ const (
 
 var CRLF = []byte{'\r', '\n'}
 
+var _ N.EarlyConn = (*ClientConn)(nil)
+
 type ClientConn struct {
 	N.ExtendedConn
 	key           [KeyLength]byte
@@ -41,6 +43,10 @@ func NewClientConn(conn net.Conn, key [KeyLength]byte, destination M.Socksaddr)
 	}
 }
 
+func (c *ClientConn) NeedHandshake() bool {
+	return !c.headerWritten
+}
+
 func (c *ClientConn) Write(p []byte) (n int, err error) {
 	if c.headerWritten {
 		return c.ExtendedConn.Write(p)
@@ -101,6 +107,10 @@ func NewClientPacketConn(conn net.Conn, key [KeyLength]byte) *ClientPacketConn {
 	}
 }
 
+func (c *ClientPacketConn) NeedHandshake() bool {
+	return !c.headerWritten
+}
+
 func (c *ClientPacketConn) ReadPacket(buffer *buf.Buffer) (M.Socksaddr, error) {
 	return ReadPacket(c.Conn, buffer)
 }