Files
gortsplib/server_session_media.go
Alessandro Ros 4f3337f56c set SSRC of outgoing packets (#803)
In client and server, each format now has a fixed, unique, known in
advance SSRC, that is applied to outgoing packets belonging to each
format.

This is needed to support SRTP/MIKEY, that require each format to have
a fixed, unique, and known in advance SSRC.

A secondary effect is that SETUP responses now always contain SSRCs of
each format, regardless of the fact that the first packet has been
produced or not (previously we needed at least one packet, from which
the SSRC was extracted).
2025-07-05 11:08:57 +02:00

417 lines
10 KiB
Go

package gortsplib
import (
"log"
"net"
"sync/atomic"
"time"
"github.com/pion/rtcp"
"github.com/pion/rtp"
"github.com/bluenviron/gortsplib/v4/pkg/description"
"github.com/bluenviron/gortsplib/v4/pkg/liberrors"
)
type serverSessionMedia struct {
ss *ServerSession
media *description.Media
onPacketRTCP OnPacketRTCPFunc
tcpChannel int
udpRTPReadPort int
udpRTPWriteAddr *net.UDPAddr
udpRTCPReadPort int
udpRTCPWriteAddr *net.UDPAddr
formats map[uint8]*serverSessionFormat // record only
writePacketRTCPInQueue func([]byte) error
bytesReceived *uint64
bytesSent *uint64
rtpPacketsInError *uint64
rtcpPacketsReceived *uint64
rtcpPacketsSent *uint64
rtcpPacketsInError *uint64
}
func (sm *serverSessionMedia) initialize() error {
sm.bytesReceived = new(uint64)
sm.bytesSent = new(uint64)
sm.rtpPacketsInError = new(uint64)
sm.rtcpPacketsReceived = new(uint64)
sm.rtcpPacketsSent = new(uint64)
sm.rtcpPacketsInError = new(uint64)
sm.formats = make(map[uint8]*serverSessionFormat)
for _, forma := range sm.media.Formats {
f := &serverSessionFormat{
sm: sm,
format: forma,
onPacketRTP: func(*rtp.Packet) {},
}
err := f.initialize()
if err != nil {
return err
}
sm.formats[forma.PayloadType()] = f
}
return nil
}
func (sm *serverSessionMedia) start() {
// allocate udpRTCPReceiver before udpRTCPListener
// otherwise udpRTCPReceiver.LastSSRC() can't be called.
for _, sf := range sm.formats {
sf.start()
}
switch *sm.ss.setuppedTransport {
case TransportUDP, TransportUDPMulticast:
sm.writePacketRTCPInQueue = sm.writePacketRTCPInQueueUDP
if *sm.ss.setuppedTransport == TransportUDP {
if sm.ss.state == ServerSessionStatePlay {
// firewall opening is performed with RTCP sender reports generated by ServerStream
if sm.media.IsBackChannel {
sm.ss.s.udpRTPListener.addClient(sm.ss.author.ip(), sm.udpRTPReadPort, sm.readPacketRTPUDPPlay)
}
sm.ss.s.udpRTCPListener.addClient(sm.ss.author.ip(), sm.udpRTCPReadPort, sm.readPacketRTCPUDPPlay)
} else {
// open the firewall by sending empty packets to the counterpart.
byts, _ := (&rtp.Packet{Header: rtp.Header{Version: 2}}).Marshal()
sm.ss.s.udpRTPListener.write(byts, sm.udpRTPWriteAddr) //nolint:errcheck
byts, _ = (&rtcp.ReceiverReport{}).Marshal()
sm.ss.s.udpRTCPListener.write(byts, sm.udpRTCPWriteAddr) //nolint:errcheck
sm.ss.s.udpRTPListener.addClient(sm.ss.author.ip(), sm.udpRTPReadPort, sm.readPacketRTPUDPRecord)
sm.ss.s.udpRTCPListener.addClient(sm.ss.author.ip(), sm.udpRTCPReadPort, sm.readPacketRTCPUDPRecord)
}
}
case TransportTCP:
sm.writePacketRTCPInQueue = sm.writePacketRTCPInQueueTCP
if sm.ss.tcpCallbackByChannel == nil {
sm.ss.tcpCallbackByChannel = make(map[int]readFunc)
}
if sm.ss.state == ServerSessionStatePlay {
sm.ss.tcpCallbackByChannel[sm.tcpChannel] = sm.readPacketRTPTCPPlay
sm.ss.tcpCallbackByChannel[sm.tcpChannel+1] = sm.readPacketRTCPTCPPlay
} else {
sm.ss.tcpCallbackByChannel[sm.tcpChannel] = sm.readPacketRTPTCPRecord
sm.ss.tcpCallbackByChannel[sm.tcpChannel+1] = sm.readPacketRTCPTCPRecord
}
}
}
func (sm *serverSessionMedia) stop() {
if *sm.ss.setuppedTransport == TransportUDP {
sm.ss.s.udpRTPListener.removeClient(sm.ss.author.ip(), sm.udpRTPReadPort)
sm.ss.s.udpRTCPListener.removeClient(sm.ss.author.ip(), sm.udpRTCPReadPort)
}
for _, sf := range sm.formats {
sf.stop()
}
}
func (sm *serverSessionMedia) findFormatByRemoteSSRC(ssrc uint32) *serverSessionFormat {
for _, format := range sm.formats {
stats := format.rtcpReceiver.Stats()
if stats != nil && stats.RemoteSSRC == ssrc {
return format
}
}
return nil
}
func (sm *serverSessionMedia) readPacketRTPUDPPlay(payload []byte) bool {
atomic.AddUint64(sm.bytesReceived, uint64(len(payload)))
if len(payload) == (udpMaxPayloadSize + 1) {
sm.onPacketRTPDecodeError(liberrors.ErrServerRTPPacketTooBigUDP{})
return false
}
pkt := &rtp.Packet{}
err := pkt.Unmarshal(payload)
if err != nil {
sm.onPacketRTPDecodeError(err)
return false
}
forma, ok := sm.formats[pkt.PayloadType]
if !ok {
sm.onPacketRTPDecodeError(liberrors.ErrServerRTPPacketUnknownPayloadType{PayloadType: pkt.PayloadType})
return false
}
now := sm.ss.s.timeNow()
forma.readPacketRTPUDP(pkt, now)
return true
}
func (sm *serverSessionMedia) readPacketRTCPUDPPlay(payload []byte) bool {
atomic.AddUint64(sm.bytesReceived, uint64(len(payload)))
if len(payload) == (udpMaxPayloadSize + 1) {
sm.onPacketRTCPDecodeError(liberrors.ErrServerRTCPPacketTooBigUDP{})
return false
}
packets, err := rtcp.Unmarshal(payload)
if err != nil {
sm.onPacketRTCPDecodeError(err)
return false
}
now := sm.ss.s.timeNow()
atomic.StoreInt64(sm.ss.udpLastPacketTime, now.Unix())
atomic.AddUint64(sm.rtcpPacketsReceived, uint64(len(packets)))
for _, pkt := range packets {
sm.onPacketRTCP(pkt)
}
return true
}
func (sm *serverSessionMedia) readPacketRTPUDPRecord(payload []byte) bool {
atomic.AddUint64(sm.bytesReceived, uint64(len(payload)))
if len(payload) == (udpMaxPayloadSize + 1) {
sm.onPacketRTPDecodeError(liberrors.ErrServerRTPPacketTooBigUDP{})
return false
}
pkt := &rtp.Packet{}
err := pkt.Unmarshal(payload)
if err != nil {
sm.onPacketRTPDecodeError(err)
return false
}
forma, ok := sm.formats[pkt.PayloadType]
if !ok {
sm.onPacketRTPDecodeError(liberrors.ErrServerRTPPacketUnknownPayloadType{PayloadType: pkt.PayloadType})
return false
}
now := sm.ss.s.timeNow()
atomic.StoreInt64(sm.ss.udpLastPacketTime, now.Unix())
forma.readPacketRTPUDP(pkt, now)
return true
}
func (sm *serverSessionMedia) readPacketRTCPUDPRecord(payload []byte) bool {
atomic.AddUint64(sm.bytesReceived, uint64(len(payload)))
if len(payload) == (udpMaxPayloadSize + 1) {
sm.onPacketRTCPDecodeError(liberrors.ErrServerRTCPPacketTooBigUDP{})
return false
}
packets, err := rtcp.Unmarshal(payload)
if err != nil {
sm.onPacketRTCPDecodeError(err)
return false
}
now := sm.ss.s.timeNow()
atomic.StoreInt64(sm.ss.udpLastPacketTime, now.Unix())
atomic.AddUint64(sm.rtcpPacketsReceived, uint64(len(packets)))
for _, pkt := range packets {
if sr, ok := pkt.(*rtcp.SenderReport); ok {
format := sm.findFormatByRemoteSSRC(sr.SSRC)
if format != nil {
format.rtcpReceiver.ProcessSenderReport(sr, now)
}
}
sm.onPacketRTCP(pkt)
}
return true
}
func (sm *serverSessionMedia) readPacketRTPTCPPlay(payload []byte) bool {
if !sm.media.IsBackChannel {
return false
}
atomic.AddUint64(sm.bytesReceived, uint64(len(payload)))
pkt := &rtp.Packet{}
err := pkt.Unmarshal(payload)
if err != nil {
sm.onPacketRTPDecodeError(err)
return false
}
forma, ok := sm.formats[pkt.PayloadType]
if !ok {
sm.onPacketRTPDecodeError(liberrors.ErrServerRTPPacketUnknownPayloadType{PayloadType: pkt.PayloadType})
return false
}
forma.readPacketRTPTCP(pkt)
return true
}
func (sm *serverSessionMedia) readPacketRTCPTCPPlay(payload []byte) bool {
atomic.AddUint64(sm.bytesReceived, uint64(len(payload)))
if len(payload) > udpMaxPayloadSize {
sm.onPacketRTCPDecodeError(liberrors.ErrServerRTCPPacketTooBig{L: len(payload), Max: udpMaxPayloadSize})
return false
}
packets, err := rtcp.Unmarshal(payload)
if err != nil {
sm.onPacketRTCPDecodeError(err)
return false
}
atomic.AddUint64(sm.rtcpPacketsReceived, uint64(len(packets)))
for _, pkt := range packets {
sm.onPacketRTCP(pkt)
}
return true
}
func (sm *serverSessionMedia) readPacketRTPTCPRecord(payload []byte) bool {
atomic.AddUint64(sm.bytesReceived, uint64(len(payload)))
pkt := &rtp.Packet{}
err := pkt.Unmarshal(payload)
if err != nil {
sm.onPacketRTPDecodeError(err)
return false
}
forma, ok := sm.formats[pkt.PayloadType]
if !ok {
sm.onPacketRTPDecodeError(liberrors.ErrServerRTPPacketUnknownPayloadType{PayloadType: pkt.PayloadType})
return false
}
forma.readPacketRTPTCP(pkt)
return true
}
func (sm *serverSessionMedia) readPacketRTCPTCPRecord(payload []byte) bool {
atomic.AddUint64(sm.bytesReceived, uint64(len(payload)))
if len(payload) > udpMaxPayloadSize {
sm.onPacketRTCPDecodeError(liberrors.ErrServerRTCPPacketTooBig{L: len(payload), Max: udpMaxPayloadSize})
return false
}
packets, err := rtcp.Unmarshal(payload)
if err != nil {
sm.onPacketRTCPDecodeError(err)
return false
}
now := sm.ss.s.timeNow()
atomic.AddUint64(sm.rtcpPacketsReceived, uint64(len(packets)))
for _, pkt := range packets {
if sr, ok := pkt.(*rtcp.SenderReport); ok {
format := sm.findFormatByRemoteSSRC(sr.SSRC)
if format != nil {
format.rtcpReceiver.ProcessSenderReport(sr, now)
}
}
sm.onPacketRTCP(pkt)
}
return true
}
func (sm *serverSessionMedia) onPacketRTPDecodeError(err error) {
atomic.AddUint64(sm.rtpPacketsInError, 1)
if h, ok := sm.ss.s.Handler.(ServerHandlerOnDecodeError); ok {
h.OnDecodeError(&ServerHandlerOnDecodeErrorCtx{
Session: sm.ss,
Error: err,
})
} else {
log.Println(err.Error())
}
}
func (sm *serverSessionMedia) onPacketRTCPDecodeError(err error) {
atomic.AddUint64(sm.rtcpPacketsInError, 1)
if h, ok := sm.ss.s.Handler.(ServerHandlerOnDecodeError); ok {
h.OnDecodeError(&ServerHandlerOnDecodeErrorCtx{
Session: sm.ss,
Error: err,
})
} else {
log.Println(err.Error())
}
}
func (sm *serverSessionMedia) writePacketRTCPEncoded(payload []byte) error {
sm.ss.writerMutex.RLock()
defer sm.ss.writerMutex.RUnlock()
if sm.ss.writer == nil {
return nil
}
ok := sm.ss.writer.push(func() error {
return sm.writePacketRTCPInQueue(payload)
})
if !ok {
return liberrors.ErrServerWriteQueueFull{}
}
return nil
}
func (sm *serverSessionMedia) writePacketRTCPInQueueUDP(payload []byte) error {
err := sm.ss.s.udpRTCPListener.write(payload, sm.udpRTCPWriteAddr)
if err != nil {
return err
}
atomic.AddUint64(sm.bytesSent, uint64(len(payload)))
atomic.AddUint64(sm.rtcpPacketsSent, 1)
return nil
}
func (sm *serverSessionMedia) writePacketRTCPInQueueTCP(payload []byte) error {
sm.ss.tcpFrame.Channel = sm.tcpChannel + 1
sm.ss.tcpFrame.Payload = payload
sm.ss.tcpConn.nconn.SetWriteDeadline(time.Now().Add(sm.ss.s.WriteTimeout))
err := sm.ss.tcpConn.conn.WriteInterleavedFrame(sm.ss.tcpFrame, sm.ss.tcpBuffer)
if err != nil {
return err
}
atomic.AddUint64(sm.bytesSent, uint64(len(payload)))
atomic.AddUint64(sm.rtcpPacketsSent, 1)
return nil
}