add intermediate layer between net.Conn and client / server

pkg/base/interleavedframe.go

@@ -7,65 +7,10 @@ import (
 )
 
 const (
-	interleavedFrameMagicByte = 0x24
+	// InterleavedFrameMagicByte is the first byte of an interleaved frame.
+	InterleavedFrameMagicByte = 0x24
 )
 
-// ReadInterleavedFrameOrRequest reads an InterleavedFrame or a Response.
-func ReadInterleavedFrameOrRequest(
-	frame *InterleavedFrame,
-	maxPayloadSize int,
-	req *Request,
-	br *bufio.Reader,
-) (interface{}, error) {
-	b, err := br.ReadByte()
-	if err != nil {
-		return nil, err
-	}
-	br.UnreadByte()
-
-	if b == interleavedFrameMagicByte {
-		err := frame.Read(maxPayloadSize, br)
-		if err != nil {
-			return nil, err
-		}
-		return frame, err
-	}
-
-	err = req.Read(br)
-	if err != nil {
-		return nil, err
-	}
-	return req, nil
-}
-
-// ReadInterleavedFrameOrResponse reads an InterleavedFrame or a Response.
-func ReadInterleavedFrameOrResponse(
-	frame *InterleavedFrame,
-	maxPayloadSize int,
-	res *Response,
-	br *bufio.Reader,
-) (interface{}, error) {
-	b, err := br.ReadByte()
-	if err != nil {
-		return nil, err
-	}
-	br.UnreadByte()
-
-	if b == interleavedFrameMagicByte {
-		err := frame.Read(maxPayloadSize, br)
-		if err != nil {
-			return nil, err
-		}
-		return frame, err
-	}
-
-	err = res.Read(br)
-	if err != nil {
-		return nil, err
-	}
-	return res, nil
-}
-
 // InterleavedFrame is an interleaved frame, and allows to transfer binary data
 // within RTSP/TCP connections. It is used to send and receive RTP and RTCP packets with TCP.
 type InterleavedFrame struct {
@@ -77,22 +22,19 @@ type InterleavedFrame struct {
 }
 
 // Read decodes an interleaved frame.
-func (f *InterleavedFrame) Read(maxPayloadSize int, br *bufio.Reader) error {
+func (f *InterleavedFrame) Read(br *bufio.Reader) error {
 	var header [4]byte
 	_, err := io.ReadFull(br, header[:])
 	if err != nil {
 		return err
 	}
 
-	if header[0] != interleavedFrameMagicByte {
+	if header[0] != InterleavedFrameMagicByte {
 		return fmt.Errorf("invalid magic byte (0x%.2x)", header[0])
 	}
 
+	// it's useless to check payloadLen since it's limited to 65535
 	payloadLen := int(uint16(header[2])<<8 | uint16(header[3]))
-	if payloadLen > maxPayloadSize {
-		return fmt.Errorf("payload size (%d) greater than maximum allowed (%d)",
-			payloadLen, maxPayloadSize)
-	}
 
 	f.Channel = int(header[1])
 	f.Payload = make([]byte, payloadLen)