From 1c507795981ece94c8b66658563d799b11bcb81f Mon Sep 17 00:00:00 2001
From: Nils Zottmann <44364366+nzottmann@users.noreply.github.com>
Date: Mon, 13 Feb 2023 13:22:38 +0100
Subject: [PATCH] Allow RTCP packets for keepalive also in state PLAY (#185)
 (#186)

* Allow RTCP packets for keepalive also in state PLAY (#185)

* use sessionTimeout instead of ReadTimeout

* reset udpLastPacketTime before PLAY and RECORD

* change error message in case of timeouts

* fix comment

---------

Co-authored-by: aler9 <46489434+aler9@users.noreply.github.com>
---
 pkg/liberrors/server.go | 16 ++++------------
 server_session.go       | 20 +++++++++++++-------
 server_session_media.go |  3 +++
 3 files changed, 20 insertions(+), 19 deletions(-)

diff --git a/pkg/liberrors/server.go b/pkg/liberrors/server.go
index 4f19606e..d0049f3a 100644
--- a/pkg/liberrors/server.go
+++ b/pkg/liberrors/server.go
@@ -24,20 +24,12 @@ func (e ErrServerSessionNotFound) Error() string {
 	return "session not found"
 }
 
-// ErrServerNoUDPPacketsInAWhile is an error that can be returned by a server.
-type ErrServerNoUDPPacketsInAWhile struct{}
+// ErrServerSessionTimedOut is an error that can be returned by a server.
+type ErrServerSessionTimedOut struct{}
 
 // Error implements the error interface.
-func (e ErrServerNoUDPPacketsInAWhile) Error() string {
-	return "no UDP packets received in a while"
-}
-
-// ErrServerNoRTSPRequestsInAWhile is an error that can be returned by a server.
-type ErrServerNoRTSPRequestsInAWhile struct{}
-
-// Error implements the error interface.
-func (e ErrServerNoRTSPRequestsInAWhile) Error() string {
-	return "no RTSP requests received in a while"
+func (e ErrServerSessionTimedOut) Error() string {
+	return "session timed out"
 }
 
 // ErrServerCSeqMissing is an error that can be returned by a server.
diff --git a/server_session.go b/server_session.go
index fd42cddd..8614056c 100644
--- a/server_session.go
+++ b/server_session.go
@@ -412,16 +412,18 @@ func (ss *ServerSession) runInner() error {
 		case <-ss.udpCheckStreamTimer.C:
 			now := time.Now()
 
+			lft := atomic.LoadInt64(ss.udpLastPacketTime)
+
 			// in case of RECORD, timeout happens when no RTP or RTCP packets are being received
 			if ss.state == ServerSessionStateRecord {
-				lft := atomic.LoadInt64(ss.udpLastPacketTime)
 				if now.Sub(time.Unix(lft, 0)) >= ss.s.ReadTimeout {
-					return liberrors.ErrServerNoUDPPacketsInAWhile{}
+					return liberrors.ErrServerSessionTimedOut{}
 				}
 
-				// in case of PLAY, timeout happens when no RTSP keepalives are being received
-			} else if now.Sub(ss.lastRequestTime) >= ss.s.sessionTimeout {
-				return liberrors.ErrServerNoRTSPRequestsInAWhile{}
+				// in case of PLAY, timeout happens when no RTSP keepalives and no RTCP packets are being received
+			} else if now.Sub(ss.lastRequestTime) >= ss.s.sessionTimeout &&
+				now.Sub(time.Unix(lft, 0)) >= ss.s.sessionTimeout {
+				return liberrors.ErrServerSessionTimedOut{}
 			}
 
 			ss.udpCheckStreamTimer = time.NewTimer(ss.s.checkStreamPeriod)
@@ -573,8 +575,6 @@ func (ss *ServerSession) handleRequest(sc *ServerConn, req *base.Request) (*base
 		ss.setuppedQuery = query
 		ss.announcedMedias = medias
 
-		v := time.Now().Unix()
-		ss.udpLastPacketTime = &v
 		return res, err
 
 	case base.Setup:
@@ -860,6 +860,9 @@ func (ss *ServerSession) handleRequest(sc *ServerConn, req *base.Request) (*base
 
 		ss.state = ServerSessionStatePlay
 
+		v := time.Now().Unix()
+		ss.udpLastPacketTime = &v
+
 		for _, sm := range ss.setuppedMedias {
 			sm.start()
 		}
@@ -949,6 +952,9 @@ func (ss *ServerSession) handleRequest(sc *ServerConn, req *base.Request) (*base
 
 		ss.state = ServerSessionStateRecord
 
+		v := time.Now().Unix()
+		ss.udpLastPacketTime = &v
+
 		for _, sm := range ss.setuppedMedias {
 			sm.start()
 		}
diff --git a/server_session_media.go b/server_session_media.go
index 41796531..ff996946 100644
--- a/server_session_media.go
+++ b/server_session_media.go
@@ -165,6 +165,9 @@ func (sm *serverSessionMedia) readRTCPUDPPlay(payload []byte) error {
 		return nil
 	}
 
+	now := time.Now()
+	atomic.StoreInt64(sm.ss.udpLastPacketTime, now.Unix())
+
 	for _, pkt := range packets {
 		sm.onPacketRTCP(pkt)
 	}