For regression test, add srs-bench to 3rdparty

trunk/3rdparty/srs-bench/vendor/github.com/pion/datachannel/datachannel.go

@@ -0,0 +1,378 @@
+// Package datachannel implements WebRTC Data Channels
+package datachannel
+
+import (
+	"fmt"
+	"io"
+	"sync/atomic"
+
+	"github.com/pion/logging"
+	"github.com/pion/sctp"
+	"github.com/pkg/errors"
+)
+
+const receiveMTU = 8192
+
+// Reader is an extended io.Reader
+// that also returns if the message is text.
+type Reader interface {
+	ReadDataChannel([]byte) (int, bool, error)
+}
+
+// Writer is an extended io.Writer
+// that also allows indicating if a message is text.
+type Writer interface {
+	WriteDataChannel([]byte, bool) (int, error)
+}
+
+// ReadWriteCloser is an extended io.ReadWriteCloser
+// that also implements our Reader and Writer.
+type ReadWriteCloser interface {
+	io.Reader
+	io.Writer
+	Reader
+	Writer
+	io.Closer
+}
+
+// DataChannel represents a data channel
+type DataChannel struct {
+	Config
+
+	// stats
+	messagesSent     uint32
+	messagesReceived uint32
+	bytesSent        uint64
+	bytesReceived    uint64
+
+	stream *sctp.Stream
+	log    logging.LeveledLogger
+}
+
+// Config is used to configure the data channel.
+type Config struct {
+	ChannelType          ChannelType
+	Negotiated           bool
+	Priority             uint16
+	ReliabilityParameter uint32
+	Label                string
+	Protocol             string
+	LoggerFactory        logging.LoggerFactory
+}
+
+func newDataChannel(stream *sctp.Stream, config *Config) (*DataChannel, error) {
+	return &DataChannel{
+		Config: *config,
+		stream: stream,
+		log:    config.LoggerFactory.NewLogger("datachannel"),
+	}, nil
+}
+
+// Dial opens a data channels over SCTP
+func Dial(a *sctp.Association, id uint16, config *Config) (*DataChannel, error) {
+	stream, err := a.OpenStream(id, sctp.PayloadTypeWebRTCBinary)
+	if err != nil {
+		return nil, err
+	}
+
+	dc, err := Client(stream, config)
+	if err != nil {
+		return nil, err
+	}
+
+	return dc, nil
+}
+
+// Client opens a data channel over an SCTP stream
+func Client(stream *sctp.Stream, config *Config) (*DataChannel, error) {
+	msg := &channelOpen{
+		ChannelType:          config.ChannelType,
+		Priority:             config.Priority,
+		ReliabilityParameter: config.ReliabilityParameter,
+
+		Label:    []byte(config.Label),
+		Protocol: []byte(config.Protocol),
+	}
+
+	if !config.Negotiated {
+		rawMsg, err := msg.Marshal()
+		if err != nil {
+			return nil, fmt.Errorf("failed to marshal ChannelOpen %v", err)
+		}
+
+		if _, err = stream.WriteSCTP(rawMsg, sctp.PayloadTypeWebRTCDCEP); err != nil {
+			return nil, fmt.Errorf("failed to send ChannelOpen %v", err)
+		}
+	}
+	return newDataChannel(stream, config)
+}
+
+// Accept is used to accept incoming data channels over SCTP
+func Accept(a *sctp.Association, config *Config) (*DataChannel, error) {
+	stream, err := a.AcceptStream()
+	if err != nil {
+		return nil, err
+	}
+
+	stream.SetDefaultPayloadType(sctp.PayloadTypeWebRTCBinary)
+
+	dc, err := Server(stream, config)
+	if err != nil {
+		return nil, err
+	}
+
+	return dc, nil
+}
+
+// Server accepts a data channel over an SCTP stream
+func Server(stream *sctp.Stream, config *Config) (*DataChannel, error) {
+	buffer := make([]byte, receiveMTU) // TODO: Can probably be smaller
+	n, ppi, err := stream.ReadSCTP(buffer)
+	if err != nil {
+		return nil, err
+	}
+
+	if ppi != sctp.PayloadTypeWebRTCDCEP {
+		return nil, fmt.Errorf("unexpected packet type: %s", ppi)
+	}
+
+	openMsg, err := parseExpectDataChannelOpen(buffer[:n])
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to parse DataChannelOpen packet")
+	}
+
+	config.ChannelType = openMsg.ChannelType
+	config.Priority = openMsg.Priority
+	config.ReliabilityParameter = openMsg.ReliabilityParameter
+	config.Label = string(openMsg.Label)
+	config.Protocol = string(openMsg.Protocol)
+
+	dataChannel, err := newDataChannel(stream, config)
+	if err != nil {
+		return nil, err
+	}
+
+	err = dataChannel.writeDataChannelAck()
+	if err != nil {
+		return nil, err
+	}
+
+	err = dataChannel.commitReliabilityParams()
+	if err != nil {
+		return nil, err
+	}
+	return dataChannel, nil
+}
+
+// Read reads a packet of len(p) bytes as binary data
+func (c *DataChannel) Read(p []byte) (int, error) {
+	n, _, err := c.ReadDataChannel(p)
+	return n, err
+}
+
+// ReadDataChannel reads a packet of len(p) bytes
+func (c *DataChannel) ReadDataChannel(p []byte) (int, bool, error) {
+	for {
+		n, ppi, err := c.stream.ReadSCTP(p)
+		if err == io.EOF {
+			// When the peer sees that an incoming stream was
+			// reset, it also resets its corresponding outgoing stream.
+			closeErr := c.stream.Close()
+			if closeErr != nil {
+				return 0, false, closeErr
+			}
+		}
+		if err != nil {
+			return 0, false, err
+		}
+
+		var isString bool
+		switch ppi {
+		case sctp.PayloadTypeWebRTCDCEP:
+			err = c.handleDCEP(p[:n])
+			if err != nil {
+				c.log.Errorf("Failed to handle DCEP: %s", err.Error())
+				continue
+			}
+			continue
+		case sctp.PayloadTypeWebRTCString, sctp.PayloadTypeWebRTCStringEmpty:
+			isString = true
+		}
+		switch ppi {
+		case sctp.PayloadTypeWebRTCBinaryEmpty, sctp.PayloadTypeWebRTCStringEmpty:
+			n = 0
+		}
+
+		atomic.AddUint32(&c.messagesReceived, 1)
+		atomic.AddUint64(&c.bytesReceived, uint64(n))
+
+		return n, isString, err
+	}
+}
+
+// MessagesSent returns the number of messages sent
+func (c *DataChannel) MessagesSent() uint32 {
+	return atomic.LoadUint32(&c.messagesSent)
+}
+
+// MessagesReceived returns the number of messages received
+func (c *DataChannel) MessagesReceived() uint32 {
+	return atomic.LoadUint32(&c.messagesReceived)
+}
+
+// BytesSent returns the number of bytes sent
+func (c *DataChannel) BytesSent() uint64 {
+	return atomic.LoadUint64(&c.bytesSent)
+}
+
+// BytesReceived returns the number of bytes received
+func (c *DataChannel) BytesReceived() uint64 {
+	return atomic.LoadUint64(&c.bytesReceived)
+}
+
+// StreamIdentifier returns the Stream identifier associated to the stream.
+func (c *DataChannel) StreamIdentifier() uint16 {
+	return c.stream.StreamIdentifier()
+}
+
+func (c *DataChannel) handleDCEP(data []byte) error {
+	msg, err := parse(data)
+	if err != nil {
+		return errors.Wrap(err, "Failed to parse DataChannel packet")
+	}
+
+	switch msg := msg.(type) {
+	case *channelOpen:
+		c.log.Debug("Received DATA_CHANNEL_OPEN")
+		err = c.writeDataChannelAck()
+		if err != nil {
+			return fmt.Errorf("failed to ACK channel open: %v", err)
+		}
+		// Note: DATA_CHANNEL_OPEN message is handled inside Server() method.
+		// Therefore, the message will not reach here.
+
+	case *channelAck:
+		c.log.Debug("Received DATA_CHANNEL_ACK")
+		err = c.commitReliabilityParams()
+		if err != nil {
+			return err
+		}
+		// TODO: handle ChannelAck (https://tools.ietf.org/html/draft-ietf-rtcweb-data-protocol-09#section-5.2)
+
+	default:
+		return fmt.Errorf("unhandled DataChannel message %v", msg)
+	}
+
+	return nil
+}
+
+// Write writes len(p) bytes from p as binary data
+func (c *DataChannel) Write(p []byte) (n int, err error) {
+	return c.WriteDataChannel(p, false)
+}
+
+// WriteDataChannel writes len(p) bytes from p
+func (c *DataChannel) WriteDataChannel(p []byte, isString bool) (n int, err error) {
+	// https://tools.ietf.org/html/draft-ietf-rtcweb-data-channel-12#section-6.6
+	// SCTP does not support the sending of empty user messages.  Therefore,
+	// if an empty message has to be sent, the appropriate PPID (WebRTC
+	// String Empty or WebRTC Binary Empty) is used and the SCTP user
+	// message of one zero byte is sent.  When receiving an SCTP user
+	// message with one of these PPIDs, the receiver MUST ignore the SCTP
+	// user message and process it as an empty message.
+	var ppi sctp.PayloadProtocolIdentifier
+	switch {
+	case !isString && len(p) > 0:
+		ppi = sctp.PayloadTypeWebRTCBinary
+	case !isString && len(p) == 0:
+		ppi = sctp.PayloadTypeWebRTCBinaryEmpty
+	case isString && len(p) > 0:
+		ppi = sctp.PayloadTypeWebRTCString
+	case isString && len(p) == 0:
+		ppi = sctp.PayloadTypeWebRTCStringEmpty
+	}
+
+	atomic.AddUint32(&c.messagesSent, 1)
+	atomic.AddUint64(&c.bytesSent, uint64(len(p)))
+
+	if len(p) == 0 {
+		_, err := c.stream.WriteSCTP([]byte{0}, ppi)
+		return 0, err
+	}
+	return c.stream.WriteSCTP(p, ppi)
+}
+
+func (c *DataChannel) writeDataChannelAck() error {
+	ack := channelAck{}
+	ackMsg, err := ack.Marshal()
+	if err != nil {
+		return fmt.Errorf("failed to marshal ChannelOpen ACK: %v", err)
+	}
+
+	_, err = c.stream.WriteSCTP(ackMsg, sctp.PayloadTypeWebRTCDCEP)
+	if err != nil {
+		return fmt.Errorf("failed to send ChannelOpen ACK: %v", err)
+	}
+
+	return err
+}
+
+// Close closes the DataChannel and the underlying SCTP stream.
+func (c *DataChannel) Close() error {
+	// https://tools.ietf.org/html/draft-ietf-rtcweb-data-channel-13#section-6.7
+	// Closing of a data channel MUST be signaled by resetting the
+	// corresponding outgoing streams [RFC6525].  This means that if one
+	// side decides to close the data channel, it resets the corresponding
+	// outgoing stream.  When the peer sees that an incoming stream was
+	// reset, it also resets its corresponding outgoing stream.  Once this
+	// is completed, the data channel is closed.  Resetting a stream sets
+	// the Stream Sequence Numbers (SSNs) of the stream back to 'zero' with
+	// a corresponding notification to the application layer that the reset
+	// has been performed.  Streams are available for reuse after a reset
+	// has been performed.
+	return c.stream.Close()
+}
+
+// BufferedAmount returns the number of bytes of data currently queued to be
+// sent over this stream.
+func (c *DataChannel) BufferedAmount() uint64 {
+	return c.stream.BufferedAmount()
+}
+
+// BufferedAmountLowThreshold returns the number of bytes of buffered outgoing
+// data that is considered "low." Defaults to 0.
+func (c *DataChannel) BufferedAmountLowThreshold() uint64 {
+	return c.stream.BufferedAmountLowThreshold()
+}
+
+// SetBufferedAmountLowThreshold is used to update the threshold.
+// See BufferedAmountLowThreshold().
+func (c *DataChannel) SetBufferedAmountLowThreshold(th uint64) {
+	c.stream.SetBufferedAmountLowThreshold(th)
+}
+
+// OnBufferedAmountLow sets the callback handler which would be called when the
+// number of bytes of outgoing data buffered is lower than the threshold.
+func (c *DataChannel) OnBufferedAmountLow(f func()) {
+	c.stream.OnBufferedAmountLow(f)
+}
+
+func (c *DataChannel) commitReliabilityParams() error {
+	switch c.Config.ChannelType {
+	case ChannelTypeReliable:
+		c.stream.SetReliabilityParams(false, sctp.ReliabilityTypeReliable, c.Config.ReliabilityParameter)
+	case ChannelTypeReliableUnordered:
+		c.stream.SetReliabilityParams(true, sctp.ReliabilityTypeReliable, c.Config.ReliabilityParameter)
+	case ChannelTypePartialReliableRexmit:
+		c.stream.SetReliabilityParams(false, sctp.ReliabilityTypeRexmit, c.Config.ReliabilityParameter)
+	case ChannelTypePartialReliableRexmitUnordered:
+		c.stream.SetReliabilityParams(true, sctp.ReliabilityTypeRexmit, c.Config.ReliabilityParameter)
+	case ChannelTypePartialReliableTimed:
+		c.stream.SetReliabilityParams(false, sctp.ReliabilityTypeTimed, c.Config.ReliabilityParameter)
+	case ChannelTypePartialReliableTimedUnordered:
+		c.stream.SetReliabilityParams(true, sctp.ReliabilityTypeTimed, c.Config.ReliabilityParameter)
+	default:
+		return fmt.Errorf("invalid ChannelType: %v ", c.Config.ChannelType)
+	}
+	return nil
+}