open the firewall in case of udp connections

client.go

@@ -1074,6 +1074,25 @@ func (c *client) runRecord() bool {
 }
 
 func (c *client) runRecordUdp() {
+	// open the firewall by sending packets to every channel
+	for _, track := range c.streamTracks {
+		c.p.serverRtp.write(
+			[]byte{0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+			&net.UDPAddr{
+				IP:   c.ip(),
+				Zone: c.zone(),
+				Port: track.rtpPort,
+			})
+
+		c.p.serverRtcp.write(
+			[]byte{0x80, 0xc9, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00},
+			&net.UDPAddr{
+				IP:   c.ip(),
+				Zone: c.zone(),
+				Port: track.rtcpPort,
+			})
+	}
+
 	readDone := make(chan error)
 	go func() {
 		for {
@@ -1111,7 +1130,7 @@ func (c *client) runRecordUdp() {
 		case <-checkStreamTicker.C:
 			for trackId := range c.streamTracks {
 				if time.Since(c.rtcpReceivers[trackId].LastFrameTime()) >= c.p.conf.ReadTimeout {
-					c.log("ERR: stream is dead")
+					c.log("ERR: no packets received recently (maybe there's a firewall/NAT)")
 					c.conn.Close()
 					<-readDone
 					c.p.clientClose <- c
@@ -1123,14 +1142,11 @@ func (c *client) runRecordUdp() {
 		case <-receiverReportTicker.C:
 			for trackId := range c.streamTracks {
 				frame := c.rtcpReceivers[trackId].Report()
-				c.p.serverRtcp.writeChan <- &udpAddrBufPair{
-					addr: &net.UDPAddr{
-						IP:   c.ip(),
-						Zone: c.zone(),
-						Port: c.streamTracks[trackId].rtcpPort,
-					},
-					buf: frame,
-				}
+				c.p.serverRtcp.write(frame, &net.UDPAddr{
+					IP:   c.ip(),
+					Zone: c.zone(),
+					Port: c.streamTracks[trackId].rtcpPort,
+				})
 			}
 
 		case <-c.terminate:

go.mod

@@ -5,7 +5,7 @@ go 1.12
 require (
 	github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751 // indirect
 	github.com/alecthomas/units v0.0.0-20190924025748-f65c72e2690d // indirect
-	github.com/aler9/gortsplib v0.0.0-20200831134901-89f0204be80e
+	github.com/aler9/gortsplib v0.0.0-20200902092059-0e827e1bc452
 	github.com/aler9/sdp/v3 v3.0.0-20200719093237-2c3d108a7436
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/stretchr/testify v1.6.1

go.sum

@@ -2,8 +2,8 @@ github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751 h1:JYp7IbQjafo
 github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20190924025748-f65c72e2690d h1:UQZhZ2O0vMHr2cI+DC1Mbh0TJxzA3RcLoMsFw+aXw7E=
 github.com/alecthomas/units v0.0.0-20190924025748-f65c72e2690d/go.mod h1:rBZYJk541a8SKzHPHnH3zbiI+7dagKZ0cgpgrD7Fyho=
-github.com/aler9/gortsplib v0.0.0-20200831134901-89f0204be80e h1:aCZXDnNPDFltytaHe/yCUmJmd7/fglhwLwStH47U6X8=
-github.com/aler9/gortsplib v0.0.0-20200831134901-89f0204be80e/go.mod h1:kBMvjIdOHRjLdV+oT28JD72JUPpJuwxOc9u72GG8GpY=
+github.com/aler9/gortsplib v0.0.0-20200902092059-0e827e1bc452 h1:w7XwvxvynGYa8YEH3QEHFdbDTlGkOZIaJAl2moEOLIA=
+github.com/aler9/gortsplib v0.0.0-20200902092059-0e827e1bc452/go.mod h1:kBMvjIdOHRjLdV+oT28JD72JUPpJuwxOc9u72GG8GpY=
 github.com/aler9/sdp/v3 v3.0.0-20200719093237-2c3d108a7436 h1:W0iNErWKvSAyJBNVx+qQoyFrWOFVgS6f/WEME/D3EZc=
 github.com/aler9/sdp/v3 v3.0.0-20200719093237-2c3d108a7436/go.mod h1:OnlEK3QI7YtM+ShZWtGajmOHLZ3bjU80AcIS5e34i1U=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=

main.go

@@ -427,22 +427,17 @@ func (p *program) forwardFrame(path *path, trackId int, streamType gortsplib.Str
 
 		if c.streamProtocol == gortsplib.StreamProtocolUdp {
 			if streamType == gortsplib.StreamTypeRtp {
-				p.serverRtp.write(&udpAddrBufPair{
-					addr: &net.UDPAddr{
-						IP:   c.ip(),
-						Zone: c.zone(),
-						Port: track.rtpPort,
-					},
-					buf: frame,
+				p.serverRtp.write(frame, &net.UDPAddr{
+					IP:   c.ip(),
+					Zone: c.zone(),
+					Port: track.rtpPort,
 				})
+
 			} else {
-				p.serverRtcp.write(&udpAddrBufPair{
-					addr: &net.UDPAddr{
-						IP:   c.ip(),
-						Zone: c.zone(),
-						Port: track.rtcpPort,
-					},
-					buf: frame,
+				p.serverRtcp.write(frame, &net.UDPAddr{
+					IP:   c.ip(),
+					Zone: c.zone(),
+					Port: track.rtcpPort,
 				})
 			}
 

server-udp.go

@@ -7,23 +7,23 @@ import (
 	"github.com/aler9/gortsplib"
 )
 
-type udpAddrBufPair struct {
-	addr *net.UDPAddr
+type udpBufAddrPair struct {
 	buf  []byte
+	addr *net.UDPAddr
 }
 
 type serverUdp struct {
 	p          *program
-	conn       *net.UDPConn
+	pc         *net.UDPConn
 	streamType gortsplib.StreamType
 	readBuf    *multiBuffer
 
-	writeChan chan *udpAddrBufPair
-	done      chan struct{}
+	writec chan udpBufAddrPair
+	done   chan struct{}
 }
 
 func newServerUdp(p *program, port int, streamType gortsplib.StreamType) (*serverUdp, error) {
-	conn, err := net.ListenUDP("udp", &net.UDPAddr{
+	pc, err := net.ListenUDP("udp", &net.UDPAddr{
 		Port: port,
 	})
 	if err != nil {
@@ -32,10 +32,10 @@ func newServerUdp(p *program, port int, streamType gortsplib.StreamType) (*serve
 
 	l := &serverUdp{
 		p:          p,
-		conn:       conn,
+		pc:         pc,
 		streamType: streamType,
 		readBuf:    newMultiBuffer(3, clientUdpReadBufferSize),
-		writeChan:  make(chan *udpAddrBufPair),
+		writec:     make(chan udpBufAddrPair),
 		done:       make(chan struct{}),
 	}
 
@@ -57,15 +57,15 @@ func (l *serverUdp) run() {
 	writeDone := make(chan struct{})
 	go func() {
 		defer close(writeDone)
-		for w := range l.writeChan {
-			l.conn.SetWriteDeadline(time.Now().Add(l.p.conf.WriteTimeout))
-			l.conn.WriteTo(w.buf, w.addr)
+		for w := range l.writec {
+			l.pc.SetWriteDeadline(time.Now().Add(l.p.conf.WriteTimeout))
+			l.pc.WriteTo(w.buf, w.addr)
 		}
 	}()
 
 	for {
 		buf := l.readBuf.next()
-		n, addr, err := l.conn.ReadFromUDP(buf)
+		n, addr, err := l.pc.ReadFromUDP(buf)
 		if err != nil {
 			break
 		}
@@ -77,17 +77,17 @@ func (l *serverUdp) run() {
 		}
 	}
 
-	close(l.writeChan)
+	close(l.writec)
 	<-writeDone
 
 	close(l.done)
 }
 
 func (l *serverUdp) close() {
-	l.conn.Close()
+	l.pc.Close()
 	<-l.done
 }
 
-func (l *serverUdp) write(pair *udpAddrBufPair) {
-	l.writeChan <- pair
+func (l *serverUdp) write(data []byte, addr *net.UDPAddr) {
+	l.writec <- udpBufAddrPair{data, addr}
 }