Update vendored github.com/Psiphon-Labs/quic-go

- Fix timer issues

vendor/github.com/Psiphon-Labs/quic-go/server.go

@@ -455,6 +455,13 @@ func (s *baseServer) createNewSession(
 	// We're already keeping track of this connection ID.
 	// This might happen if we receive two copies of the Initial at the same time.
 	if !added {
+
+		// [Psiphon]
+		// Stop timer to release resources
+		if s, ok := sess.(*session); ok {
+			s.timer.Reset(time.Time{})
+		}
+
 		return nil
 	}
 	s.sessionHandler.Add(srcConnID, sess)

vendor/github.com/Psiphon-Labs/quic-go/session.go

@@ -446,6 +446,19 @@ func (s *session) preSetup() {
 	}
 }
 
+// [Psiphon]
+//
+// Backport https://github.com/lucas-clemente/quic-go/commit/079279b9cf4cb5dafc8b7f673a2e7e47a4b6a06e:
+//   > session.maybeResetTimer() and session.run() were using slightly
+//   > different definitions of when a keep-alive PING should be sent. Under
+//   > certain conditions, this would make us repeatedly set a timer for the
+//   > keep-alive, but on timer expiration no keep-alive would be sent.
+//
+// This changes session.run and session.maybeResetTimer. As we don't yet have
+// https://github.com/lucas-clemente/quic-go/commit/27549c56656665859354255d3912f6428bfcb9f0,
+// "use the minimum of the two peers' max_idle_timeouts", s.config.IdleTimeout is used
+// in place of s.idleTimeout.
+
 // run the session main loop
 func (s *session) run() error {
 	defer s.ctxCancel()
@@ -516,11 +529,17 @@ runLoop:
 		if s.pacingDeadline.IsZero() { // the timer didn't have a pacing deadline set
 			pacingDeadline = s.sentPacketHandler.TimeUntilSend()
 		}
-		if s.config.KeepAlive && !s.keepAlivePingSent && s.handshakeComplete && s.firstAckElicitingPacketAfterIdleSentTime.IsZero() && time.Since(s.lastPacketReceivedTime) >= s.keepAliveInterval/2 {
+		if keepAliveTime := s.nextKeepAliveTime(); !keepAliveTime.IsZero() && !now.Before(keepAliveTime) {
 			// send a PING frame since there is no activity in the session
-			s.logger.Debugf("Sending a keep-alive ping to keep the connection alive.")
+			s.logger.Debugf("Sending a keep-alive PING to keep the connection alive.")
 			s.framer.QueueControlFrame(&wire.PingFrame{})
 			s.keepAlivePingSent = true
+		} else if !s.handshakeComplete && now.Sub(s.sessionCreationTime) >= s.config.HandshakeTimeout {
+			s.destroyImpl(qerr.TimeoutError("Handshake did not complete in time"))
+			continue
+		} else if s.handshakeComplete && now.Sub(s.idleTimeoutStartTime()) >= s.config.IdleTimeout {
+			s.destroyImpl(qerr.TimeoutError("No recent network activity"))
+			continue
 		} else if !pacingDeadline.IsZero() && now.Before(pacingDeadline) {
 			// If we get to this point before the pacing deadline, we should wait until that deadline.
 			// This can happen when scheduleSending is called, or a packet is received.
@@ -571,12 +590,25 @@ func (s *session) ConnectionState() tls.ConnectionState {
 	return s.cryptoStreamHandler.ConnectionState()
 }
 
+// Time when the next keep-alive packet should be sent.
+// It returns a zero time if no keep-alive should be sent.
+func (s *session) nextKeepAliveTime() time.Time {
+	if !s.config.KeepAlive || s.keepAlivePingSent || s.firstAckElicitingPacketAfterIdleSentTime.IsZero() {
+		return time.Time{}
+	}
+	return s.lastPacketReceivedTime.Add(s.keepAliveInterval / 2)
+}
+
 func (s *session) maybeResetTimer() {
 	var deadline time.Time
-	if s.config.KeepAlive && s.handshakeComplete && !s.keepAlivePingSent {
-		deadline = s.idleTimeoutStartTime().Add(s.keepAliveInterval / 2)
+	if !s.handshakeComplete {
+		deadline = s.sessionCreationTime.Add(s.config.HandshakeTimeout)
 	} else {
-		deadline = s.idleTimeoutStartTime().Add(s.config.IdleTimeout)
+		if keepAliveTime := s.nextKeepAliveTime(); !keepAliveTime.IsZero() {
+			deadline = keepAliveTime
+		} else {
+			deadline = s.idleTimeoutStartTime().Add(s.config.IdleTimeout)
+		}
 	}
 
 	if ackAlarm := s.receivedPacketHandler.GetAlarmTimeout(); !ackAlarm.IsZero() {
@@ -585,10 +617,6 @@ func (s *session) maybeResetTimer() {
 	if lossTime := s.sentPacketHandler.GetLossDetectionTimeout(); !lossTime.IsZero() {
 		deadline = utils.MinTime(deadline, lossTime)
 	}
-	if !s.handshakeComplete {
-		handshakeDeadline := s.sessionCreationTime.Add(s.config.HandshakeTimeout)
-		deadline = utils.MinTime(deadline, handshakeDeadline)
-	}
 	if !s.pacingDeadline.IsZero() {
 		deadline = utils.MinTime(deadline, s.pacingDeadline)
 	}

vendor/vendor.json

@@ -75,10 +75,10 @@
 			"revisionTime": "2019-12-04T18:36:04Z"
 		},
 		{
-			"checksumSHA1": "8MdwAjQlha5clFXwY1ayF4vNGAQ=",
+			"checksumSHA1": "atufb9edlfrNCDiyupCgjjRRQ10=",
 			"path": "github.com/Psiphon-Labs/quic-go",
-			"revision": "738e15bfe6c3d7a0ccc91e2f237e5554ab6a35a6",
-			"revisionTime": "2020-01-28T19:39:28Z"
+			"revision": "474e74c89fab6c1356b6653b9e1de707b4e4ef8b",
+			"revisionTime": "2020-03-06T19:33:10Z"
 		},
 		{
 			"checksumSHA1": "VMJLFpeoJ56PTQxR0wEkkiQTr1s=",