implement the IETF draft BLOCKED and STREAM_BLOCKED frames

internal/wire/blocked_frame.go

@@ -4,38 +4,32 @@ import (
 	"bytes"
 
 	"github.com/lucas-clemente/quic-go/internal/protocol"
-	"github.com/lucas-clemente/quic-go/internal/utils"
 )
 
-// A BlockedFrame in QUIC
-type BlockedFrame struct {
-	StreamID protocol.StreamID
+// A BlockedFrame is a BLOCKED frame
+type BlockedFrame struct{}
+
+// ParseBlockedFrame parses a BLOCKED frame
+func ParseBlockedFrame(r *bytes.Reader, version protocol.VersionNumber) (*BlockedFrame, error) {
+	if _, err := r.ReadByte(); err != nil {
+		return nil, err
+	}
+	return &BlockedFrame{}, nil
 }
 
-//Write writes a BlockedFrame frame
 func (f *BlockedFrame) Write(b *bytes.Buffer, version protocol.VersionNumber) error {
-	b.WriteByte(0x05)
-	utils.GetByteOrder(version).WriteUint32(b, uint32(f.StreamID))
+	if !version.UsesMaxDataFrame() {
+		return (&blockedFrameLegacy{}).Write(b, version)
+	}
+	typeByte := uint8(0x08)
+	b.WriteByte(typeByte)
 	return nil
 }
 
 // MinLength of a written frame
 func (f *BlockedFrame) MinLength(version protocol.VersionNumber) (protocol.ByteCount, error) {
-	return 1 + 4, nil
-}
-
-// ParseBlockedFrame parses a BLOCKED frame
-func ParseBlockedFrame(r *bytes.Reader, version protocol.VersionNumber) (*BlockedFrame, error) {
-	frame := &BlockedFrame{}
-
-	// read the TypeByte
-	if _, err := r.ReadByte(); err != nil {
-		return nil, err
+	if !version.UsesMaxDataFrame() { // writing this frame would result in a legacy BLOCKED being written, which is longer
+		return 1 + 4, nil
 	}
-	sid, err := utils.GetByteOrder(version).ReadUint32(r)
-	if err != nil {
-		return nil, err
-	}
-	frame.StreamID = protocol.StreamID(sid)
-	return frame, nil
+	return 1, nil
 }

internal/wire/blocked_frame_legacy.go

@@ -0,0 +1,38 @@
+package wire
+
+import (
+	"bytes"
+
+	"github.com/lucas-clemente/quic-go/internal/protocol"
+	"github.com/lucas-clemente/quic-go/internal/utils"
+)
+
+type blockedFrameLegacy struct {
+	StreamID protocol.StreamID
+}
+
+// ParseBlockedFrameLegacy parses a BLOCKED frame (in gQUIC format)
+// The frame returned is
+// * a STREAM_BLOCKED frame, if the BLOCKED applies to a stream
+// * a BLOCKED frame, if the BLOCKED applies to the connection
+func ParseBlockedFrameLegacy(r *bytes.Reader, version protocol.VersionNumber) (Frame, error) {
+	// read the TypeByte
+	if _, err := r.ReadByte(); err != nil {
+		return nil, err
+	}
+	streamID, err := utils.GetByteOrder(version).ReadUint32(r)
+	if err != nil {
+		return nil, err
+	}
+	if streamID == 0 {
+		return &BlockedFrame{}, nil
+	}
+	return &StreamBlockedFrame{StreamID: protocol.StreamID(streamID)}, nil
+}
+
+//Write writes a BLOCKED frame
+func (f *blockedFrameLegacy) Write(b *bytes.Buffer, version protocol.VersionNumber) error {
+	b.WriteByte(0x05)
+	utils.GetByteOrder(version).WriteUint32(b, uint32(f.StreamID))
+	return nil
+}

internal/wire/blocked_frame_legacy_test.go

@@ -0,0 +1,89 @@
+package wire
+
+import (
+	"bytes"
+
+	"github.com/lucas-clemente/quic-go/internal/protocol"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("legacy BLOCKED Frame", func() {
+	Context("when parsing", func() {
+		Context("in little endian", func() {
+			It("accepts sample frame", func() {
+				b := bytes.NewReader([]byte{0x5, 0xef, 0xbe, 0xad, 0xde})
+				f, err := ParseBlockedFrameLegacy(b, versionLittleEndian)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(f).To(BeAssignableToTypeOf(&StreamBlockedFrame{}))
+				frame := f.(*StreamBlockedFrame)
+				Expect(frame.StreamID).To(Equal(protocol.StreamID(0xdeadbeef)))
+			})
+		})
+
+		Context("in big endian", func() {
+			It("accepts sample frame for a stream", func() {
+				b := bytes.NewReader([]byte{0x5, 0xde, 0xad, 0xbe, 0xef})
+				f, err := ParseBlockedFrameLegacy(b, versionBigEndian)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(f).To(BeAssignableToTypeOf(&StreamBlockedFrame{}))
+				frame := f.(*StreamBlockedFrame)
+				Expect(frame.StreamID).To(Equal(protocol.StreamID(0xdeadbeef)))
+			})
+
+			It("accepts sample frame for the connection", func() {
+				b := bytes.NewReader([]byte{0x5, 0x0, 0x0, 0x0, 0x0})
+				f, err := ParseBlockedFrameLegacy(b, versionBigEndian)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(f).To(BeAssignableToTypeOf(&BlockedFrame{}))
+			})
+		})
+
+		It("errors on EOFs", func() {
+			data := []byte{0x5, 0xef, 0xbe, 0xad, 0xde}
+			_, err := ParseBlockedFrameLegacy(bytes.NewReader(data), protocol.VersionWhatever)
+			Expect(err).NotTo(HaveOccurred())
+			for i := range data {
+				_, err := ParseBlockedFrameLegacy(bytes.NewReader(data[0:i]), protocol.VersionWhatever)
+				Expect(err).To(HaveOccurred())
+			}
+		})
+	})
+
+	Context("when writing", func() {
+		Context("in little endian", func() {
+			It("writes a sample frame", func() {
+				b := &bytes.Buffer{}
+				frame := StreamBlockedFrame{StreamID: 0x1337}
+				frame.Write(b, versionLittleEndian)
+				Expect(b.Bytes()).To(Equal([]byte{0x5, 0x37, 0x13, 0x0, 0x0}))
+			})
+		})
+
+		Context("in big endian", func() {
+			It("writes a BLOCKED frame for a stream", func() {
+				b := &bytes.Buffer{}
+				frame := StreamBlockedFrame{StreamID: 0x1337}
+				frame.Write(b, versionBigEndian)
+				Expect(b.Bytes()).To(Equal([]byte{0x5, 0x0, 0x0, 0x13, 0x37}))
+			})
+
+			It("has the correct min length for a BLOCKED frame for a stream", func() {
+				frame := StreamBlockedFrame{StreamID: 3}
+				Expect(frame.MinLength(0)).To(Equal(protocol.ByteCount(5)))
+			})
+
+			It("writes a BLOCKED frame for the connection", func() {
+				b := &bytes.Buffer{}
+				frame := BlockedFrame{}
+				frame.Write(b, versionBigEndian)
+				Expect(b.Bytes()).To(Equal([]byte{0x5, 0x0, 0x0, 0x0, 0x0}))
+			})
+
+			It("has the correct min length for a BLOCKED frame for the connection", func() {
+				frame := BlockedFrame{}
+				Expect(frame.MinLength(versionBigEndian)).To(Equal(protocol.ByteCount(5)))
+			})
+		})
+	})
+})

internal/wire/blocked_frame_test.go

@@ -4,70 +4,38 @@ import (
 	"bytes"
 
 	"github.com/lucas-clemente/quic-go/internal/protocol"
+
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
 )
 
-var _ = Describe("BlockedFrame", func() {
+var _ = Describe("BLOCKED frame", func() {
 	Context("when parsing", func() {
-		Context("in little endian", func() {
-			It("accepts sample frame", func() {
-				b := bytes.NewReader([]byte{0x5, 0xef, 0xbe, 0xad, 0xde})
-				frame, err := ParseBlockedFrame(b, versionLittleEndian)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(frame.StreamID).To(Equal(protocol.StreamID(0xdeadbeef)))
-			})
-		})
-
-		Context("in big endian", func() {
-			It("accepts sample frame", func() {
-				b := bytes.NewReader([]byte{0x5, 0xde, 0xad, 0xbe, 0xef})
-				frame, err := ParseBlockedFrame(b, versionBigEndian)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(frame.StreamID).To(Equal(protocol.StreamID(0xdeadbeef)))
-			})
+		It("accepts sample frame", func() {
+			b := bytes.NewReader([]byte{0x08})
+			_, err := ParseBlockedFrame(b, protocol.VersionWhatever)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(b.Len()).To(BeZero())
 		})
 
 		It("errors on EOFs", func() {
-			data := []byte{0x5, 0xef, 0xbe, 0xad, 0xde}
-			_, err := ParseBlockedFrame(bytes.NewReader(data), protocol.VersionWhatever)
-			Expect(err).NotTo(HaveOccurred())
-			for i := range data {
-				_, err := ParseBlockedFrame(bytes.NewReader(data[0:i]), protocol.VersionWhatever)
-				Expect(err).To(HaveOccurred())
-			}
+			_, err := ParseBlockedFrame(bytes.NewReader(nil), protocol.VersionWhatever)
+			Expect(err).To(HaveOccurred())
 		})
 	})
 
 	Context("when writing", func() {
-		Context("in little endian", func() {
-			It("writes a sample frame", func() {
-				b := &bytes.Buffer{}
-				frame := BlockedFrame{StreamID: 0x1337}
-				frame.Write(b, versionLittleEndian)
-				Expect(b.Bytes()).To(Equal([]byte{0x5, 0x37, 0x13, 0x0, 0x0}))
-			})
-		})
-
-		Context("in big endian", func() {
-			It("writes a sample frame", func() {
-				b := &bytes.Buffer{}
-				frame := BlockedFrame{StreamID: 0x1337}
-				frame.Write(b, versionBigEndian)
-				Expect(b.Bytes()).To(Equal([]byte{0x5, 0x0, 0x0, 0x13, 0x37}))
-			})
-		})
-
-		It("writes a connection-level Blocked", func() {
+		It("writes a sample frame", func() {
 			b := &bytes.Buffer{}
-			frame := BlockedFrame{StreamID: 0}
-			frame.Write(b, 0)
-			Expect(b.Bytes()).To(Equal([]byte{0x5, 0, 0, 0, 0}))
+			frame := BlockedFrame{}
+			err := frame.Write(b, protocol.VersionWhatever)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(b.Bytes()).To(Equal([]byte{0x08}))
 		})
 
 		It("has the correct min length", func() {
-			frame := BlockedFrame{StreamID: 3}
-			Expect(frame.MinLength(0)).To(Equal(protocol.ByteCount(5)))
+			frame := BlockedFrame{}
+			Expect(frame.MinLength(versionMaxDataFrame)).To(Equal(protocol.ByteCount(1)))
 		})
 	})
 })

internal/wire/stream_blocked_frame.go

@@ -0,0 +1,44 @@
+package wire
+
+import (
+	"bytes"
+
+	"github.com/lucas-clemente/quic-go/internal/protocol"
+	"github.com/lucas-clemente/quic-go/internal/utils"
+)
+
+// A StreamBlockedFrame in QUIC
+type StreamBlockedFrame struct {
+	StreamID protocol.StreamID
+}
+
+// ParseStreamBlockedFrame parses a STREAM_BLOCKED frame
+func ParseStreamBlockedFrame(r *bytes.Reader, version protocol.VersionNumber) (*StreamBlockedFrame, error) {
+	frame := &StreamBlockedFrame{}
+
+	// read the TypeByte
+	if _, err := r.ReadByte(); err != nil {
+		return nil, err
+	}
+	sid, err := utils.GetByteOrder(version).ReadUint32(r)
+	if err != nil {
+		return nil, err
+	}
+	frame.StreamID = protocol.StreamID(sid)
+	return frame, nil
+}
+
+// Write writes a STREAM_BLOCKED frame
+func (f *StreamBlockedFrame) Write(b *bytes.Buffer, version protocol.VersionNumber) error {
+	if !version.UsesMaxDataFrame() {
+		return (&blockedFrameLegacy{StreamID: f.StreamID}).Write(b, version)
+	}
+	b.WriteByte(0x09)
+	utils.GetByteOrder(version).WriteUint32(b, uint32(f.StreamID))
+	return nil
+}
+
+// MinLength of a written frame
+func (f *StreamBlockedFrame) MinLength(version protocol.VersionNumber) (protocol.ByteCount, error) {
+	return 1 + 4, nil
+}

internal/wire/stream_blocked_frame_test.go

@@ -0,0 +1,57 @@
+package wire
+
+import (
+	"bytes"
+
+	"github.com/lucas-clemente/quic-go/internal/protocol"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("STREAM_BLOCKED frame", func() {
+	Context("parsing", func() {
+		It("accepts sample frame", func() {
+			b := bytes.NewReader([]byte{0x9,
+				0xde, 0xad, 0xbe, 0xef, // stream id
+			})
+			frame, err := ParseStreamBlockedFrame(b, versionMaxDataFrame)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(frame.StreamID).To(Equal(protocol.StreamID(0xdeadbeef)))
+			Expect(b.Len()).To(BeZero())
+		})
+
+		It("errors on EOFs", func() {
+			data := []byte{0x9,
+				0xef, 0xbe, 0xad, 0xde, // stream id
+			}
+			_, err := ParseStreamBlockedFrame(bytes.NewReader(data), versionMaxDataFrame)
+			Expect(err).NotTo(HaveOccurred())
+			for i := range data {
+				_, err := ParseStreamBlockedFrame(bytes.NewReader(data[0:i]), versionMaxDataFrame)
+				Expect(err).To(HaveOccurred())
+			}
+		})
+	})
+
+	Context("writing", func() {
+		It("has proper min length", func() {
+			f := &StreamBlockedFrame{
+				StreamID: 0x1337,
+			}
+			Expect(f.MinLength(0)).To(Equal(protocol.ByteCount(5)))
+		})
+
+		It("writes a sample frame", func() {
+			b := &bytes.Buffer{}
+			f := &StreamBlockedFrame{
+				StreamID: 0xdecafbad,
+			}
+			err := f.Write(b, versionMaxDataFrame)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(b.Bytes()).To(Equal([]byte{0x9,
+				0xde, 0xca, 0xfb, 0xad, // stream id
+			}))
+		})
+	})
+})

packet_packer_test.go

@@ -301,7 +301,7 @@ var _ = Describe("Packet packer", func() {
 	})
 
 	It("packs a packet if it has queued control frames, but no new control frames", func() {
-		packer.controlFrames = []wire.Frame{&wire.BlockedFrame{StreamID: 0}}
+		packer.controlFrames = []wire.Frame{&wire.BlockedFrame{}}
 		p, err := packer.PackPacket()
 		Expect(err).ToNot(HaveOccurred())
 		Expect(p).ToNot(BeNil())
@@ -326,9 +326,7 @@ var _ = Describe("Packet packer", func() {
 	})
 
 	It("packs a lot of control frames into 2 packets if they don't fit into one", func() {
-		blockedFrame := &wire.BlockedFrame{
-			StreamID: 0x1337,
-		}
+		blockedFrame := &wire.BlockedFrame{}
 		minLength, _ := blockedFrame.MinLength(0)
 		maxFramesPerPacket := int(maxFrameSize) / int(minLength)
 		var controlFrames []wire.Frame
@@ -607,7 +605,7 @@ var _ = Describe("Packet packer", func() {
 	Context("Blocked frames", func() {
 		It("queues a BLOCKED frame", func() {
 			length := 100
-			streamFramer.blockedFrameQueue = []*wire.BlockedFrame{{StreamID: 5}}
+			streamFramer.blockedFrameQueue = []wire.Frame{&wire.StreamBlockedFrame{StreamID: 5}}
 			f := &wire.StreamFrame{
 				StreamID: 5,
 				Data:     bytes.Repeat([]byte{'f'}, length),
@@ -615,12 +613,12 @@ var _ = Describe("Packet packer", func() {
 			streamFramer.AddFrameForRetransmission(f)
 			_, err := packer.composeNextPacket(maxFrameSize, true)
 			Expect(err).ToNot(HaveOccurred())
-			Expect(packer.controlFrames[0]).To(Equal(&wire.BlockedFrame{StreamID: 5}))
+			Expect(packer.controlFrames[0]).To(Equal(&wire.StreamBlockedFrame{StreamID: 5}))
 		})
 
 		It("removes the dataLen attribute from the last StreamFrame, even if it queued a BLOCKED frame", func() {
 			length := 100
-			streamFramer.blockedFrameQueue = []*wire.BlockedFrame{{StreamID: 5}}
+			streamFramer.blockedFrameQueue = []wire.Frame{&wire.StreamBlockedFrame{StreamID: 5}}
 			f := &wire.StreamFrame{
 				StreamID: 5,
 				Data:     bytes.Repeat([]byte{'f'}, length),
@@ -633,7 +631,7 @@ var _ = Describe("Packet packer", func() {
 		})
 
 		It("packs a connection-level BlockedFrame", func() {
-			streamFramer.blockedFrameQueue = []*wire.BlockedFrame{{StreamID: 0}}
+			streamFramer.blockedFrameQueue = []wire.Frame{&wire.BlockedFrame{}}
 			f := &wire.StreamFrame{
 				StreamID: 5,
 				Data:     []byte("foobar"),
@@ -641,7 +639,7 @@ var _ = Describe("Packet packer", func() {
 			streamFramer.AddFrameForRetransmission(f)
 			_, err := packer.composeNextPacket(maxFrameSize, true)
 			Expect(err).ToNot(HaveOccurred())
-			Expect(packer.controlFrames[0]).To(Equal(&wire.BlockedFrame{StreamID: 0}))
+			Expect(packer.controlFrames[0]).To(Equal(&wire.BlockedFrame{}))
 		})
 	})
 

packet_unpacker.go

@@ -94,7 +94,7 @@ func (u *packetUnpacker) Unpack(headerBinary []byte, hdr *wire.Header, data []by
 				err = qerr.Error(qerr.InvalidWindowUpdateData, err.Error())
 			}
 		} else if typeByte == 0x5 { // in gQUIC, 0x5  is a BLOCKED frame
-			frame, err = wire.ParseBlockedFrame(r, u.version)
+			frame, err = wire.ParseBlockedFrameLegacy(r, u.version)
 			if err != nil {
 				err = qerr.Error(qerr.InvalidBlockedData, err.Error())
 			}
@@ -105,6 +105,13 @@ func (u *packetUnpacker) Unpack(headerBinary []byte, hdr *wire.Header, data []by
 			}
 		} else if typeByte == 0x7 {
 			frame, err = wire.ParsePingFrame(r, u.version)
+		} else if u.version.UsesMaxDataFrame() && typeByte == 0x8 { // in IETF QUIC, 0x4 is a BLOCKED frame
+			frame, err = wire.ParseBlockedFrame(r, u.version)
+		} else if u.version.UsesMaxDataFrame() && typeByte == 0x9 { // in IETF QUIC, 0x4 is a STREAM_BLOCKED frame
+			frame, err = wire.ParseBlockedFrameLegacy(r, u.version)
+			if err != nil {
+				err = qerr.Error(qerr.InvalidBlockedData, err.Error())
+			}
 		} else {
 			err = qerr.Error(qerr.InvalidFrameData, fmt.Sprintf("unknown type byte 0x%x", typeByte))
 		}

packet_unpacker_test.go

@@ -183,10 +183,33 @@ var _ = Describe("Packet unpacker", func() {
 			Expect(packet.frames).To(Equal([]wire.Frame{f}))
 		})
 
+		It("unpacks connection-level BLOCKED frames", func() {
+			f := &wire.BlockedFrame{}
+			buf := &bytes.Buffer{}
+			err := f.Write(buf, versionCryptoStream0)
+			Expect(err).ToNot(HaveOccurred())
+			setData(buf.Bytes())
+			packet, err := unpacker.Unpack(hdrBin, hdr, data)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(packet.frames).To(Equal([]wire.Frame{f}))
+		})
+
+		It("unpacks stream-level BLOCKED frames", func() {
+			f := &wire.StreamBlockedFrame{StreamID: 0xdeadbeef}
+			buf := &bytes.Buffer{}
+			err := f.Write(buf, versionCryptoStream0)
+			Expect(err).ToNot(HaveOccurred())
+			setData(buf.Bytes())
+			packet, err := unpacker.Unpack(hdrBin, hdr, data)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(packet.frames).To(Equal([]wire.Frame{f}))
+		})
+
 		It("errors on invalid frames", func() {
 			for b, e := range map[byte]qerr.ErrorCode{
 				0x04: qerr.InvalidWindowUpdateData,
 				0x05: qerr.InvalidWindowUpdateData,
+				0x09: qerr.InvalidBlockedData,
 			} {
 				setData([]byte{b})
 				_, err := unpacker.Unpack(hdrBin, hdr, data)
@@ -227,10 +250,21 @@ var _ = Describe("Packet unpacker", func() {
 			Expect(packet.frames).To(Equal([]wire.Frame{f}))
 		})
 
-		It("unpacks BLOCKED frames", func() {
-			f := &wire.BlockedFrame{StreamID: 0xDEADBEEF}
+		It("unpacks connection-level BLOCKED frames", func() {
+			f := &wire.BlockedFrame{}
 			buf := &bytes.Buffer{}
-			err := f.Write(buf, protocol.VersionWhatever)
+			err := f.Write(buf, versionCryptoStream1)
+			Expect(err).ToNot(HaveOccurred())
+			setData(buf.Bytes())
+			packet, err := unpacker.Unpack(hdrBin, hdr, data)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(packet.frames).To(Equal([]wire.Frame{f}))
+		})
+
+		It("unpacks stream-level BLOCKED frames", func() {
+			f := &wire.StreamBlockedFrame{StreamID: 0xdeadbeef}
+			buf := &bytes.Buffer{}
+			err := f.Write(buf, versionCryptoStream1)
 			Expect(err).ToNot(HaveOccurred())
 			setData(buf.Bytes())
 			packet, err := unpacker.Unpack(hdrBin, hdr, data)
@@ -269,9 +303,9 @@ var _ = Describe("Packet unpacker", func() {
 	})
 
 	It("errors on invalid type", func() {
-		setData([]byte{0x08})
+		setData([]byte{0xf})
 		_, err := unpacker.Unpack(hdrBin, hdr, data)
-		Expect(err).To(MatchError("InvalidFrameData: unknown type byte 0x8"))
+		Expect(err).To(MatchError("InvalidFrameData: unknown type byte 0xf"))
 	})
 
 	It("errors on invalid frames", func() {

session.go

@@ -496,6 +496,7 @@ func (s *session) handleFrames(fs []wire.Frame) error {
 		case *wire.MaxStreamDataFrame:
 			err = s.handleMaxStreamDataFrame(frame)
 		case *wire.BlockedFrame:
+		case *wire.StreamBlockedFrame:
 		case *wire.PingFrame:
 		default:
 			return errors.New("Session BUG: unexpected frame type")

stream_framer.go

@@ -13,7 +13,7 @@ type streamFramer struct {
 	connFlowController flowcontrol.ConnectionFlowController
 
 	retransmissionQueue []*wire.StreamFrame
-	blockedFrameQueue   []*wire.BlockedFrame
+	blockedFrameQueue   []wire.Frame
 }
 
 func newStreamFramer(
@@ -37,7 +37,7 @@ func (f *streamFramer) PopStreamFrames(maxLen protocol.ByteCount) []*wire.Stream
 	return append(fs, f.maybePopNormalFrames(maxLen-currentLen)...)
 }
 
-func (f *streamFramer) PopBlockedFrame() *wire.BlockedFrame {
+func (f *streamFramer) PopBlockedFrame() wire.Frame {
 	if len(f.blockedFrameQueue) == 0 {
 		return nil
 	}
@@ -132,10 +132,10 @@ func (f *streamFramer) maybePopNormalFrames(maxBytes protocol.ByteCount) (res []
 
 		// Finally, check if we are now FC blocked and should queue a BLOCKED frame
 		if !frame.FinBit && s.IsFlowControlBlocked() {
-			f.blockedFrameQueue = append(f.blockedFrameQueue, &wire.BlockedFrame{StreamID: s.StreamID()})
+			f.blockedFrameQueue = append(f.blockedFrameQueue, &wire.StreamBlockedFrame{StreamID: s.StreamID()})
 		}
 		if f.connFlowController.IsBlocked() {
-			f.blockedFrameQueue = append(f.blockedFrameQueue, &wire.BlockedFrame{StreamID: 0})
+			f.blockedFrameQueue = append(f.blockedFrameQueue, &wire.BlockedFrame{})
 		}
 
 		res = append(res, frame)

stream_framer_test.go

@@ -326,9 +326,10 @@ var _ = Describe("Stream Framer", func() {
 			setNoData(stream2)
 			frames := framer.PopStreamFrames(1000)
 			Expect(frames).To(HaveLen(1))
-			blockedFrame := framer.PopBlockedFrame()
-			Expect(blockedFrame).ToNot(BeNil())
-			Expect(blockedFrame.StreamID).To(Equal(stream1.StreamID()))
+			f := framer.PopBlockedFrame()
+			Expect(f).To(BeAssignableToTypeOf(&wire.StreamBlockedFrame{}))
+			bf := f.(*wire.StreamBlockedFrame)
+			Expect(bf.StreamID).To(Equal(stream1.StreamID()))
 			Expect(framer.PopBlockedFrame()).To(BeNil())
 		})
 
@@ -357,9 +358,8 @@ var _ = Describe("Stream Framer", func() {
 			stream1.EXPECT().IsFlowControlBlocked().Return(false)
 			setNoData(stream2)
 			framer.PopStreamFrames(1000)
-			blockedFrame := framer.PopBlockedFrame()
-			Expect(blockedFrame).ToNot(BeNil())
-			Expect(blockedFrame.StreamID).To(BeZero())
+			f := framer.PopBlockedFrame()
+			Expect(f).To(BeAssignableToTypeOf(&wire.BlockedFrame{}))
 			Expect(framer.PopBlockedFrame()).To(BeNil())
 		})
 	})