never increase the flow control limit for the crypto stream

receive_stream.go

@@ -164,7 +164,9 @@ func (s *receiveStream) readImpl(p []byte) (bool /*stream completed */, int, err
 			s.flowController.AddBytesRead(protocol.ByteCount(m))
 		}
 		// increase the flow control window, if necessary
-		s.flowController.MaybeQueueWindowUpdate()
+		if s.streamID != s.version.CryptoStreamID() {
+			s.flowController.MaybeQueueWindowUpdate()
+		}
 
 		if s.readPosInFrame >= len(s.currentFrame) && s.currentFrameIsLast {
 			s.finRead = true

send_stream.go

@@ -186,7 +186,6 @@ func (s *sendStream) getDataForWriting(maxBytes protocol.ByteCount) ([]byte, boo
 		return nil, s.finishedWriting && !s.finSent
 	}
 
-	// TODO(#657): Flow control for the crypto stream
 	if s.streamID != s.version.CryptoStreamID() {
 		maxBytes = utils.MinByteCount(maxBytes, s.flowController.SendWindowSize())
 	}

session.go

@@ -440,7 +440,7 @@ func (s *session) postSetup() error {
 	s.sessionCreationTime = now
 
 	s.receivedPacketHandler = ackhandler.NewReceivedPacketHandler(s.rttStats, s.logger, s.version)
-	s.windowUpdateQueue = newWindowUpdateQueue(s.streamsMap, s.cryptoStream, s.connFlowController, s.packer.QueueControlFrame)
+	s.windowUpdateQueue = newWindowUpdateQueue(s.streamsMap, s.connFlowController, s.packer.QueueControlFrame)
 	return nil
 }
 

window_update_queue.go

@@ -14,7 +14,6 @@ type windowUpdateQueue struct {
 	queue      map[protocol.StreamID]bool // used as a set
 	queuedConn bool                       // connection-level window update
 
-	cryptoStream       cryptoStream
 	streamGetter       streamGetter
 	connFlowController flowcontrol.ConnectionFlowController
 	callback           func(wire.Frame)
@@ -22,14 +21,12 @@ type windowUpdateQueue struct {
 
 func newWindowUpdateQueue(
 	streamGetter streamGetter,
-	cryptoStream cryptoStream,
 	connFC flowcontrol.ConnectionFlowController,
 	cb func(wire.Frame),
 ) *windowUpdateQueue {
 	return &windowUpdateQueue{
 		queue:              make(map[protocol.StreamID]bool),
 		streamGetter:       streamGetter,
-		cryptoStream:       cryptoStream,
 		connFlowController: connFC,
 		callback:           cb,
 	}
@@ -55,17 +52,12 @@ func (q *windowUpdateQueue) QueueAll() {
 		q.queuedConn = false
 	}
 	// queue all stream-level window updates
-	var offset protocol.ByteCount
 	for id := range q.queue {
-		if id == q.cryptoStream.StreamID() {
+		str, err := q.streamGetter.GetOrOpenReceiveStream(id)
-			offset = q.cryptoStream.getWindowUpdate()
+		if err != nil || str == nil { // the stream can be nil if it was completed before dequeing the window update
-		} else {
+			continue
-			str, err := q.streamGetter.GetOrOpenReceiveStream(id)
-			if err != nil || str == nil { // the stream can be nil if it was completed before dequeing the window update
-				continue
-			}
-			offset = str.getWindowUpdate()
 		}
+		offset := str.getWindowUpdate()
 		if offset == 0 { // can happen if we received a final offset, right after queueing the window update
 			continue
 		}

window_update_queue_test.go

@@ -15,16 +15,13 @@ var _ = Describe("Window Update Queue", func() {
 		streamGetter *MockStreamGetter
 		connFC       *mocks.MockConnectionFlowController
 		queuedFrames []wire.Frame
-		cryptoStream *MockCryptoStream
 	)
 
 	BeforeEach(func() {
 		streamGetter = NewMockStreamGetter(mockCtrl)
-		cryptoStream = NewMockCryptoStream(mockCtrl)
 		connFC = mocks.NewMockConnectionFlowController(mockCtrl)
-		cryptoStream.EXPECT().StreamID().Return(protocol.StreamID(0)).AnyTimes()
 		queuedFrames = queuedFrames[:0]
-		q = newWindowUpdateQueue(streamGetter, cryptoStream, connFC, func(f wire.Frame) {
+		q = newWindowUpdateQueue(streamGetter, connFC, func(f wire.Frame) {
 			queuedFrames = append(queuedFrames, f)
 		})
 	})
@@ -70,15 +67,6 @@ var _ = Describe("Window Update Queue", func() {
 		Expect(queuedFrames).To(BeEmpty())
 	})
 
-	It("adds MAX_STREAM_DATA frames for the crypto stream", func() {
-		cryptoStream.EXPECT().getWindowUpdate().Return(protocol.ByteCount(42))
-		q.AddStream(0)
-		q.QueueAll()
-		Expect(queuedFrames).To(Equal([]wire.Frame{
-			&wire.MaxStreamDataFrame{StreamID: 0, ByteOffset: 42},
-		}))
-	})
-
 	It("queues MAX_DATA frames", func() {
 		connFC.EXPECT().GetWindowUpdate().Return(protocol.ByteCount(0x1337))
 		q.AddConnection()