Add a public API to send RTCP packets

Relates to #63

internal/network/manager.go

@@ -159,6 +159,22 @@ func (m *Manager) SendRTP(packet *rtp.Packet) {
 	}
 }
 
+// SendRTCP finds a connected port and sends the passed RTCP packet
+func (m *Manager) SendRTCP(pkt []byte) {
+	m.portsLock.Lock()
+	defer m.portsLock.Unlock()
+
+	local, remote := m.IceAgent.SelectedPair()
+	if local == nil || remote == nil {
+		return
+	}
+	for _, p := range m.ports {
+		if p.listeningAddr.Equal(local) {
+			p.sendRTCP(pkt, remote)
+		}
+	}
+}
+
 // SendDataChannelMessage sends a DataChannel message to a connected peer
 func (m *Manager) SendDataChannelMessage(payload datachannel.Payload, streamIdentifier uint16) error {
 	var data []byte

internal/network/port-send.go

@@ -11,7 +11,8 @@ func (p *port) sendRTP(packet *rtp.Packet, dst net.Addr) {
 	p.m.srtpOutboundContextLock.Lock()
 	defer p.m.srtpOutboundContextLock.Unlock()
 	if p.m.srtpOutboundContext == nil {
-		fmt.Printf("Tried to send RTP packet but no SRTP Context to handle it \n")
+		// TODO log-level
+		// fmt.Printf("Tried to send RTP packet but no SRTP Context to handle it \n")
 		return
 	}
 
@@ -40,3 +41,22 @@ func (p *port) sendSCTP(buf []byte, dst fmt.Stringer) {
 		fmt.Println(err)
 	}
 }
+
+func (p *port) sendRTCP(buf []byte, dst net.Addr) {
+	p.m.srtpOutboundContextLock.Lock()
+	defer p.m.srtpOutboundContextLock.Unlock()
+	if p.m.srtpOutboundContext == nil {
+		fmt.Printf("Tried to send RTCP packet but no SRTP Context to handle it \n")
+		return
+	}
+
+	encrypted, err := p.m.srtpOutboundContext.EncryptRTCP(buf)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	if _, err := p.conn.WriteTo(encrypted, nil, dst); err != nil {
+		fmt.Printf("Failed to send packet: %s \n", err.Error())
+	}
+}

pkg/rtcp/header.go

@@ -9,11 +9,13 @@ type PacketType uint8
 
 // RTCP packet types registered with IANA. See: https://www.iana.org/assignments/rtp-parameters/rtp-parameters.xhtml#rtp-parameters-4
 const (
-	TypeSenderReport       PacketType = 200 // RFC 3550, 6.4.1
-	TypeReceiverReport     PacketType = 201 // RFC 3550, 6.4.2
-	TypeSourceDescription  PacketType = 202 // RFC 3550, 6.5
-	TypeGoodbye            PacketType = 203 // RFC 3550, 6.6
-	TypeApplicationDefined PacketType = 204 // RFC 3550, 6.7 (unimplemented)
+	TypeSenderReport            PacketType = 200 // RFC 3550, 6.4.1
+	TypeReceiverReport          PacketType = 201 // RFC 3550, 6.4.2
+	TypeSourceDescription       PacketType = 202 // RFC 3550, 6.5
+	TypeGoodbye                 PacketType = 203 // RFC 3550, 6.6
+	TypeApplicationDefined      PacketType = 204 // RFC 3550, 6.7 (unimplemented)
+	TypePayloadSpecificFeedback PacketType = 206 // RFC 4585, 6.3
+
 )
 
 func (p PacketType) String() string {
@@ -28,6 +30,8 @@ func (p PacketType) String() string {
 		return "BYE"
 	case TypeApplicationDefined:
 		return "APP"
+	case TypePayloadSpecificFeedback:
+		return "PSFB"
 	default:
 		return string(p)
 	}
@@ -41,7 +45,7 @@ type Header struct {
 	// some additional padding octets at the end which are not part of
 	// the control information but are included in the length field.
 	Padding bool
-	// The number of reception reports or sources contained in this packet (depending on the Type)
+	// The number of reception reports, sources contained or FMT in this packet (depending on the Type)
 	Count uint8
 	// The RTCP packet type for this packet
 	Type PacketType

pkg/rtcp/packet.go

@@ -0,0 +1,7 @@
+package rtcp
+
+// Packet represents an RTCP packet, a protocol used for out-of-band statistics and control information for an RTP session
+type Packet interface {
+	Marshal() ([]byte, error)
+	Unmarshal(rawPacket []byte) error
+}

rtcpeerconnection.go

@@ -18,6 +18,7 @@ import (
 	"github.com/pions/webrtc/pkg/ice"
 	"github.com/pions/webrtc/pkg/media"
 	"github.com/pions/webrtc/pkg/rtcerr"
+	"github.com/pions/webrtc/pkg/rtcp"
 	"github.com/pions/webrtc/pkg/rtp"
 	"github.com/pkg/errors"
 )
@@ -719,6 +720,17 @@ func (pc *RTCPeerConnection) SetIdentityProvider(provider string) error {
 	return errors.Errorf("TODO SetIdentityProvider")
 }
 
+// SendRTCP sends a user provided RTCP packet to the connected peer
+// If no peer is connected the packet is discarded
+func (pc *RTCPeerConnection) SendRTCP(pkt rtcp.Packet) error {
+	raw, err := pkt.Marshal()
+	if err != nil {
+		return err
+	}
+	pc.networkManager.SendRTCP(raw)
+	return nil
+}
+
 // Close ends the RTCPeerConnection
 func (pc *RTCPeerConnection) Close() error {
 	pc.networkManager.Close()