allow 0-RTT when the server's stream receive limit is increased

integrationtests/self/zero_rtt_test.go

@@ -22,21 +22,26 @@ import (
 	. "github.com/onsi/gomega"
 )
 
+type rcvdPacket struct {
+	hdr    *logging.ExtendedHeader
+	frames []logging.Frame
+}
+
 type rcvdPacketTracer struct {
 	connTracer
 	closed      chan struct{}
-	rcvdPackets []*logging.ExtendedHeader
+	rcvdPackets []rcvdPacket
 }
 
 func newRcvdPacketTracer() *rcvdPacketTracer {
 	return &rcvdPacketTracer{closed: make(chan struct{})}
 }
 
-func (t *rcvdPacketTracer) ReceivedPacket(hdr *logging.ExtendedHeader, _ logging.ByteCount, _ []logging.Frame) {
-	t.rcvdPackets = append(t.rcvdPackets, hdr)
+func (t *rcvdPacketTracer) ReceivedPacket(hdr *logging.ExtendedHeader, _ logging.ByteCount, frames []logging.Frame) {
+	t.rcvdPackets = append(t.rcvdPackets, rcvdPacket{hdr: hdr, frames: frames})
 }
 func (t *rcvdPacketTracer) Close() { close(t.closed) }
-func (t *rcvdPacketTracer) getRcvdPackets() []*logging.ExtendedHeader {
+func (t *rcvdPacketTracer) getRcvdPackets() []rcvdPacket {
 	<-t.closed
 	return t.rcvdPackets
 }
@@ -187,11 +192,11 @@ var _ = Describe("0-RTT", func() {
 			}
 
 			// can be used to extract 0-RTT from a rcvdPacketTracer
-			get0RTTPackets := func(hdrs []*logging.ExtendedHeader) []protocol.PacketNumber {
+			get0RTTPackets := func(packets []rcvdPacket) []protocol.PacketNumber {
 				var zeroRTTPackets []protocol.PacketNumber
-				for _, hdr := range hdrs {
-					if hdr.Type == protocol.PacketType0RTT {
-						zeroRTTPackets = append(zeroRTTPackets, hdr.PacketNumber)
+				for _, p := range packets {
+					if p.hdr.Type == protocol.PacketType0RTT {
+						zeroRTTPackets = append(zeroRTTPackets, p.hdr.PacketNumber)
 					}
 				}
 				return zeroRTTPackets
@@ -545,6 +550,78 @@ var _ = Describe("0-RTT", func() {
 				Expect(get0RTTPackets(tracer.getRcvdPackets())).To(BeEmpty())
 			})
 
+			It("doesn't reject 0-RTT when the server's transport stream flow control limit increased", func() {
+				tlsConf, clientConf := dialAndReceiveSessionTicket(getQuicConfig(&quic.Config{
+					InitialStreamReceiveWindow: 3,
+					AcceptToken:                func(_ net.Addr, _ *quic.Token) bool { return true },
+				}))
+
+				tracer := newRcvdPacketTracer()
+				ln, err := quic.ListenAddrEarly(
+					"localhost:0",
+					tlsConf,
+					getQuicConfig(&quic.Config{
+						Versions:                   []protocol.VersionNumber{version},
+						AcceptToken:                func(_ net.Addr, _ *quic.Token) bool { return true },
+						InitialStreamReceiveWindow: 100,
+						Tracer:                     newTracer(func() logging.ConnectionTracer { return tracer }),
+					}),
+				)
+				Expect(err).ToNot(HaveOccurred())
+				defer ln.Close()
+				proxy, _ := runCountingProxy(ln.Addr().(*net.UDPAddr).Port)
+				defer proxy.Close()
+
+				sess, err := quic.DialAddrEarly(
+					fmt.Sprintf("localhost:%d", proxy.LocalPort()),
+					clientConf,
+					getQuicConfig(&quic.Config{Versions: []protocol.VersionNumber{version}}),
+				)
+				Expect(err).ToNot(HaveOccurred())
+				str, err := sess.OpenUniStream()
+				Expect(err).ToNot(HaveOccurred())
+				written := make(chan struct{})
+				go func() {
+					defer GinkgoRecover()
+					defer close(written)
+					_, err := str.Write([]byte("foobar"))
+					Expect(err).ToNot(HaveOccurred())
+					Expect(str.Close()).To(Succeed())
+				}()
+
+				Eventually(written).Should(BeClosed())
+
+				serverSess, err := ln.Accept(context.Background())
+				Expect(err).ToNot(HaveOccurred())
+				rstr, err := serverSess.AcceptUniStream(context.Background())
+				Expect(err).ToNot(HaveOccurred())
+				data, err := ioutil.ReadAll(rstr)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(data).To(Equal([]byte("foobar")))
+				Expect(serverSess.ConnectionState().TLS.Used0RTT).To(BeTrue())
+				Expect(serverSess.CloseWithError(0, "")).To(Succeed())
+				Eventually(sess.Context().Done()).Should(BeClosed())
+
+				var processedFirst bool
+				for _, p := range tracer.getRcvdPackets() {
+					for _, f := range p.frames {
+						if sf, ok := f.(*logging.StreamFrame); ok {
+							if !processedFirst {
+								// The first STREAM should have been sent in a 0-RTT packet.
+								// Due to the flow control limit, the STREAM frame was limit to the first 3 bytes.
+								Expect(p.hdr.Type).To(Equal(protocol.PacketType0RTT))
+								Expect(sf.Length).To(BeEquivalentTo(3))
+								processedFirst = true
+							} else {
+								// All other STREAM frames can only be sent after handshake completion.
+								Expect(p.hdr.IsLongHeader).To(BeFalse())
+								Expect(sf.Offset).ToNot(BeZero())
+							}
+						}
+					}
+				}
+			})
+
 			It("correctly deals with 0-RTT rejections", func() {
 				tlsConf, clientConf := dialAndReceiveSessionTicket(nil)
 				// now dial new connection with different transport parameters
@@ -648,7 +725,7 @@ var _ = Describe("0-RTT", func() {
 
 				transfer0RTTData(ln, proxy.LocalPort(), clientConf, PRData, true)
 
-				Expect(tracer.rcvdPackets[0].Type).To(Equal(protocol.PacketTypeInitial))
+				Expect(tracer.rcvdPackets[0].hdr.Type).To(Equal(protocol.PacketTypeInitial))
 				zeroRTTPackets := get0RTTPackets(tracer.getRcvdPackets())
 				Expect(len(zeroRTTPackets)).To(BeNumerically(">", 10))
 				Expect(zeroRTTPackets[0]).To(Equal(protocol.PacketNumber(0)))

internal/wire/transport_parameter_test.go

@@ -498,28 +498,43 @@ var _ = Describe("Transport Parameters", func() {
 				Expect(p.ValidFor0RTT(saved)).To(BeTrue())
 			})
 
-			It("rejects the parameters if the InitialMaxStreamDataBidiLocal changed", func() {
-				p.InitialMaxStreamDataBidiLocal = 0
+			It("rejects the parameters if the InitialMaxStreamDataBidiLocal was reduced", func() {
+				p.InitialMaxStreamDataBidiLocal = saved.InitialMaxStreamDataBidiLocal - 1
 				Expect(p.ValidFor0RTT(saved)).To(BeFalse())
 			})
 
-			It("rejects the parameters if the InitialMaxStreamDataBidiRemote changed", func() {
-				p.InitialMaxStreamDataBidiRemote = 0
+			It("doesn't reject the parameters if the InitialMaxStreamDataBidiLocal was increased", func() {
+				p.InitialMaxStreamDataBidiLocal = saved.InitialMaxStreamDataBidiLocal + 1
+				Expect(p.ValidFor0RTT(saved)).To(BeTrue())
+			})
+
+			It("rejects the parameters if the InitialMaxStreamDataBidiRemote was reduced", func() {
+				p.InitialMaxStreamDataBidiRemote = saved.InitialMaxStreamDataBidiRemote - 1
 				Expect(p.ValidFor0RTT(saved)).To(BeFalse())
 			})
 
-			It("rejects the parameters if the InitialMaxStreamDataUni changed", func() {
-				p.InitialMaxStreamDataUni = 0
+			It("doesn't reject the parameters if the InitialMaxStreamDataBidiRemote was increased", func() {
+				p.InitialMaxStreamDataBidiRemote = saved.InitialMaxStreamDataBidiRemote + 1
+				Expect(p.ValidFor0RTT(saved)).To(BeTrue())
+			})
+
+			It("rejects the parameters if the InitialMaxStreamDataUni was reduced", func() {
+				p.InitialMaxStreamDataUni = saved.InitialMaxStreamDataUni - 1
 				Expect(p.ValidFor0RTT(saved)).To(BeFalse())
 			})
 
+			It("doesn't reject the parameters if the InitialMaxStreamDataUni was increased", func() {
+				p.InitialMaxStreamDataUni = saved.InitialMaxStreamDataUni + 1
+				Expect(p.ValidFor0RTT(saved)).To(BeTrue())
+			})
+
 			It("rejects the parameters if the InitialMaxData changed", func() {
 				p.InitialMaxData = 0
 				Expect(p.ValidFor0RTT(saved)).To(BeFalse())
 			})
 
-			It("rejects the parameters if the MaxBidiStreamNum changed", func() {
-				p.MaxBidiStreamNum = 0
+			It("rejects the parameters if the MaxBidiStreamNum was reduced", func() {
+				p.MaxBidiStreamNum = saved.MaxBidiStreamNum - 1
 				Expect(p.ValidFor0RTT(saved)).To(BeFalse())
 			})
 

internal/wire/transport_parameters.go

@@ -441,9 +441,9 @@ func (p *TransportParameters) UnmarshalFromSessionTicket(r *bytes.Reader) error
 
 // ValidFor0RTT checks if the transport parameters match those saved in the session ticket.
 func (p *TransportParameters) ValidFor0RTT(saved *TransportParameters) bool {
-	return p.InitialMaxStreamDataBidiLocal == saved.InitialMaxStreamDataBidiLocal &&
-		p.InitialMaxStreamDataBidiRemote == saved.InitialMaxStreamDataBidiRemote &&
-		p.InitialMaxStreamDataUni == saved.InitialMaxStreamDataUni &&
+	return p.InitialMaxStreamDataBidiLocal >= saved.InitialMaxStreamDataBidiLocal &&
+		p.InitialMaxStreamDataBidiRemote >= saved.InitialMaxStreamDataBidiRemote &&
+		p.InitialMaxStreamDataUni >= saved.InitialMaxStreamDataUni &&
 		p.InitialMaxData == saved.InitialMaxData &&
 		p.MaxBidiStreamNum >= saved.MaxBidiStreamNum &&
 		p.MaxUniStreamNum >= saved.MaxUniStreamNum &&