drop support for v31

fixes #214

frames/ack_frame_legacy.go

@@ -97,11 +97,6 @@ func (f *AckFrameLegacy) Write(b *bytes.Buffer, version protocol.VersionNumber)
 		if rangeCounter != uint8(numRanges) {
 			return errors.New("BUG: Inconsistent number of NACK ranges written")
 		}
-
-		// TODO: Remove once we drop support for <32
-		if version < protocol.Version32 {
-			b.WriteByte(0)
-		}
 	}
 
 	return nil
@@ -114,7 +109,6 @@ func (f *AckFrameLegacy) MinLength(version protocol.VersionNumber) (protocol.Byt
 	l += (1 + 2) * 0 /* TODO: num_timestamps */
 	if f.HasNACK() {
 		l += 1 + (6+1)*int(f.numWrittenNackRanges())
-		l++ // TODO: Remove once we drop support for <32
 	}
 	return protocol.ByteCount(l), nil
 }
@@ -257,21 +251,6 @@ func ParseAckFrameLegacy(r *bytes.Reader, version protocol.VersionNumber) (*AckF
 				frame.NackRanges = append(frame.NackRanges, nackRange)
 			}
 		}
-
-		// TODO: Remove once we drop support for versions <32
-		if version < protocol.Version32 {
-			numRevived, err := r.ReadByte()
-			if err != nil {
-				return nil, err
-			}
-
-			for i := uint8(0); i < numRevived; i++ {
-				_, err := utils.ReadUintN(r, largestObservedLen)
-				if err != nil {
-					return nil, err
-				}
-			}
-		}
 	}
 
 	if !frame.validateNackRanges() {

frames/ack_frame_legacy_test.go

@@ -99,38 +99,6 @@ var _ = Describe("AckFrame", func() {
 			Expect(b.Len()).To(Equal(0))
 		})
 
-		Context("support for version 31", func() {
-			It("support a simple ACK with one NACK range, version 31", func() {
-				b := bytes.NewReader([]byte{0x60, 0x8, 0x3, 0x72, 0x1, 0x1, 0x0, 0xc0, 0x15, 0x0, 0x0, 0x1, 0x1, 0x1, 0x0})
-				frame, err := ParseAckFrameLegacy(b, protocol.Version31)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(frame.HasNACK()).To(Equal(true))
-				Expect(frame.NackRanges).To(HaveLen(1))
-				Expect(frame.LargestObserved).To(Equal(protocol.PacketNumber(3)))
-				Expect(frame.NackRanges[0]).To(Equal(NackRange{FirstPacketNumber: 1, LastPacketNumber: 2}))
-				Expect(b.Len()).To(Equal(0))
-			})
-
-			It("support a simple ACK with multiple NACK ranges, version 31", func() {
-				b := bytes.NewReader([]byte{0x60, 0x8, 0x9, 0x72, 0x1, 0x1, 0x0, 0xc0, 0x15, 0x0, 0x0, 0x2, 0x1, 0x1, 0x2, 0x0, 0x0})
-				frame, err := ParseAckFrameLegacy(b, protocol.Version31)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(frame.HasNACK()).To(Equal(true))
-				Expect(frame.NackRanges).To(HaveLen(2))
-				Expect(frame.LargestObserved).To(Equal(protocol.PacketNumber(9)))
-				Expect(frame.NackRanges[0]).To(Equal(NackRange{FirstPacketNumber: 7, LastPacketNumber: 8}))
-				Expect(frame.NackRanges[1]).To(Equal(NackRange{FirstPacketNumber: 4, LastPacketNumber: 4}))
-				Expect(b.Len()).To(Equal(0))
-			})
-
-			It("reads the complete ACK frame if it contains revived packet numbers", func() {
-				b := bytes.NewReader([]byte{0x60, 0x8, 0x3, 0x72, 0x1, 0x1, 0x0, 0xc0, 0x15, 0x0, 0x0, 0x1, 0x1, 0x1, 0x3, 0x5, 0x6, 0x7})
-				_, err := ParseAckFrameLegacy(b, protocol.Version31)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(b.Len()).To(Equal(0))
-			})
-		})
-
 		Context("contiguous NACK ranges", func() {
 			It("parses a frame with a contiguous NACK range spanning two fields", func() {
 				b := bytes.NewReader([]byte{0x64, 0x8, 0x2E, 0x01, 0x72, 0x1, 0x1, 0x0, 0xc0, 0x15, 0x0, 0x0, 0x2, 0x1, 0x2b, 0x0, 0xff})
@@ -324,23 +292,6 @@ var _ = Describe("AckFrame", func() {
 			Expect(packetNumber).To(BeEquivalentTo([]byte{2, 0, 0, 0, 0, 0}))
 		})
 
-		It("supports version 31", func() {
-			frame := AckFrameLegacy{
-				Entropy:         2,
-				LargestObserved: 4,
-				NackRanges:      []NackRange{{FirstPacketNumber: 2, LastPacketNumber: 2}},
-			}
-			err := frame.Write(b, protocol.Version31)
-			Expect(err).ToNot(HaveOccurred())
-			missingPacketBytes := b.Bytes()[b.Len()-9:]
-			Expect(missingPacketBytes[0]).To(Equal(uint8(1))) // numRanges
-			Expect(missingPacketBytes[7]).To(Equal(uint8(0))) // rangeLength
-			packetNumber := make([]byte, 6)
-			copy(packetNumber, missingPacketBytes[1:6])
-			Expect(packetNumber).To(BeEquivalentTo([]byte{2, 0, 0, 0, 0, 0}))
-			Expect(b.Bytes()[b.Len()-1]).To(BeZero())
-		})
-
 		It("writes a frame with multiple NACK ranges", func() {
 			nackRange1 := NackRange{FirstPacketNumber: 4, LastPacketNumber: 6}
 			nackRange2 := NackRange{FirstPacketNumber: 2, LastPacketNumber: 2}
@@ -518,7 +469,7 @@ var _ = Describe("AckFrame", func() {
 					LargestObserved: 4,
 					NackRanges:      []NackRange{{FirstPacketNumber: 2, LastPacketNumber: 2}},
 				}
-				err := f.Write(b, protocol.Version31)
+				err := f.Write(b, protocol.Version33)
 				Expect(err).ToNot(HaveOccurred())
 				Expect(f.MinLength(0)).To(Equal(protocol.ByteCount(b.Len())))
 			})
@@ -529,7 +480,7 @@ var _ = Describe("AckFrame", func() {
 					LargestObserved: 3000,
 					NackRanges:      []NackRange{{FirstPacketNumber: 2, LastPacketNumber: 2000}},
 				}
-				err := f.Write(b, protocol.Version31)
+				err := f.Write(b, protocol.Version33)
 				Expect(err).ToNot(HaveOccurred())
 				Expect(f.MinLength(0)).To(Equal(protocol.ByteCount(b.Len())))
 			})

h2quic/server_test.go

@@ -163,7 +163,7 @@ var _ = Describe("H2 server", func() {
 
 	Context("setting http headers", func() {
 		expected := http.Header{
-			"Alt-Svc":            {`quic=":443"; ma=2592000; v="34,33,32,31"`},
+			"Alt-Svc":            {`quic=":443"; ma=2592000; v="34,33,32"`},
 			"Alternate-Protocol": {`443:quic`},
 		}
 

protocol/version.go

@@ -11,8 +11,7 @@ type VersionNumber int
 
 // The version numbers, making grepping easier
 const (
-	Version31 VersionNumber = 31 + iota
+	Version32 VersionNumber = 32 + iota
-	Version32
 	Version33
 	Version34
 	VersionWhatever = 0 // for when the version doesn't matter
@@ -20,7 +19,7 @@ const (
 
 // SupportedVersions lists the versions that the server supports
 var SupportedVersions = []VersionNumber{
-	Version31, Version32, Version33, Version34,
+	Version32, Version33, Version34,
 }
 
 // SupportedVersionsAsTags is needed for the SHLO crypto message

protocol/version_test.go

@@ -17,11 +17,11 @@ var _ = Describe("Version", func() {
 	})
 
 	It("has proper tag list", func() {
-		Expect(SupportedVersionsAsTags).To(Equal([]byte("Q031Q032Q033Q034")))
+		Expect(SupportedVersionsAsTags).To(Equal([]byte("Q032Q033Q034")))
 	})
 
 	It("has proper version list", func() {
-		Expect(SupportedVersionsAsString).To(Equal("34,33,32,31"))
+		Expect(SupportedVersionsAsString).To(Equal("34,33,32"))
 	})
 
 	It("recognizes supported versions", func() {