Merge pull request #3096 from lucas-clemente/allow-zero-rtt-on-initial-window-increase

allow 0-RTT when flow control windows are increased

integrationtests/self/zero_rtt_test.go

@@ -19,24 +19,30 @@ import (
 	"github.com/lucas-clemente/quic-go/logging"
 
 	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/ginkgo/extensions/table"
 	. "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) {
+func (t *rcvdPacketTracer) ReceivedPacket(hdr *logging.ExtendedHeader, _ logging.ByteCount, frames []logging.Frame) {
-	t.rcvdPackets = append(t.rcvdPackets, hdr)
+	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 +193,11 @@ 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 {
+				for _, p := range packets {
-					if hdr.Type == protocol.PacketType0RTT {
+					if p.hdr.Type == protocol.PacketType0RTT {
-						zeroRTTPackets = append(zeroRTTPackets, hdr.PacketNumber)
+						zeroRTTPackets = append(zeroRTTPackets, p.hdr.PacketNumber)
 					}
 				}
 				return zeroRTTPackets
@@ -545,6 +551,85 @@ var _ = Describe("0-RTT", func() {
 				Expect(get0RTTPackets(tracer.getRcvdPackets())).To(BeEmpty())
 			})
 
+			DescribeTable("flow control limits",
+				func(addFlowControlLimit func(*quic.Config, uint64)) {
+					tracer := newRcvdPacketTracer()
+					firstConf := getQuicConfig(&quic.Config{
+						AcceptToken: func(_ net.Addr, _ *quic.Token) bool { return true },
+						Versions:    []protocol.VersionNumber{version},
+					})
+					addFlowControlLimit(firstConf, 3)
+					tlsConf, clientConf := dialAndReceiveSessionTicket(firstConf)
+
+					secondConf := getQuicConfig(&quic.Config{
+						Versions:    []protocol.VersionNumber{version},
+						AcceptToken: func(_ net.Addr, _ *quic.Token) bool { return true },
+						Tracer:      newTracer(func() logging.ConnectionTracer { return tracer }),
+					})
+					addFlowControlLimit(secondConf, 100)
+					ln, err := quic.ListenAddrEarly(
+						"localhost:0",
+						tlsConf,
+						secondConf,
+					)
+					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())
+								}
+							}
+						}
+					}
+				},
+				Entry("doesn't reject 0-RTT when the server's transport stream flow control limit increased", func(c *quic.Config, limit uint64) { c.InitialStreamReceiveWindow = limit }),
+				Entry("doesn't reject 0-RTT when the server's transport connection flow control limit increased", func(c *quic.Config, limit uint64) { c.InitialConnectionReceiveWindow = limit }),
+			)
+
 			It("correctly deals with 0-RTT rejections", func() {
 				tlsConf, clientConf := dialAndReceiveSessionTicket(nil)
 				// now dial new connection with different transport parameters
@@ -662,7 +747,7 @@ 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/handshake/crypto_setup_test.go

@@ -776,7 +776,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 				Expect(client.ConnectionState().Used0RTT).To(BeTrue())
 			})
 
-			It("rejects 0-RTT, whent the transport parameters changed", func() {
+			It("rejects 0-RTT, when the transport parameters changed", func() {
 				csc := mocktls.NewMockClientSessionCache(mockCtrl)
 				var state *tls.ClientSessionState
 				receivedSessionTicket := make(chan struct{})
@@ -810,7 +810,7 @@ var _ = Describe("Crypto Setup TLS", func() {
 				clientHelloWrittenChan, client, clientErr, server, serverErr = handshakeWithTLSConf(
 					clientConf, serverConf,
 					clientRTTStats, &utils.RTTStats{},
-					&wire.TransportParameters{}, &wire.TransportParameters{InitialMaxData: initialMaxData + 1},
+					&wire.TransportParameters{}, &wire.TransportParameters{InitialMaxData: initialMaxData - 1},
 					true,
 				)
 				Expect(clientErr).ToNot(HaveOccurred())

internal/wire/transport_parameter_test.go

@@ -498,28 +498,48 @@ var _ = Describe("Transport Parameters", func() {
 				Expect(p.ValidFor0RTT(saved)).To(BeTrue())
 			})
 
-			It("rejects the parameters if the InitialMaxStreamDataBidiLocal changed", func() {
+			It("rejects the parameters if the InitialMaxStreamDataBidiLocal was reduced", func() {
-				p.InitialMaxStreamDataBidiLocal = 0
+				p.InitialMaxStreamDataBidiLocal = saved.InitialMaxStreamDataBidiLocal - 1
 				Expect(p.ValidFor0RTT(saved)).To(BeFalse())
 			})
 
-			It("rejects the parameters if the InitialMaxStreamDataBidiRemote changed", func() {
+			It("doesn't reject the parameters if the InitialMaxStreamDataBidiLocal was increased", func() {
-				p.InitialMaxStreamDataBidiRemote = 0
+				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() {
+			It("doesn't reject the parameters if the InitialMaxStreamDataBidiRemote was increased", func() {
-				p.InitialMaxStreamDataUni = 0
+				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("rejects the parameters if the InitialMaxData changed", func() {
+			It("doesn't reject the parameters if the InitialMaxStreamDataUni was increased", func() {
-				p.InitialMaxData = 0
+				p.InitialMaxStreamDataUni = saved.InitialMaxStreamDataUni + 1
+				Expect(p.ValidFor0RTT(saved)).To(BeTrue())
+			})
+
+			It("rejects the parameters if the InitialMaxData was reduced", func() {
+				p.InitialMaxData = saved.InitialMaxData - 1
 				Expect(p.ValidFor0RTT(saved)).To(BeFalse())
 			})
 
-			It("rejects the parameters if the MaxBidiStreamNum changed", func() {
+			It("doesn't reject the parameters if the InitialMaxData was increased", func() {
-				p.MaxBidiStreamNum = 0
+				p.InitialMaxData = saved.InitialMaxData + 1
+				Expect(p.ValidFor0RTT(saved)).To(BeTrue())
+			})
+
+			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

@@ -441,10 +441,10 @@ 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 &&
+	return p.InitialMaxStreamDataBidiLocal >= saved.InitialMaxStreamDataBidiLocal &&
-		p.InitialMaxStreamDataBidiRemote == saved.InitialMaxStreamDataBidiRemote &&
+		p.InitialMaxStreamDataBidiRemote >= saved.InitialMaxStreamDataBidiRemote &&
-		p.InitialMaxStreamDataUni == saved.InitialMaxStreamDataUni &&
+		p.InitialMaxStreamDataUni >= saved.InitialMaxStreamDataUni &&
-		p.InitialMaxData == saved.InitialMaxData &&
+		p.InitialMaxData >= saved.InitialMaxData &&
 		p.MaxBidiStreamNum >= saved.MaxBidiStreamNum &&
 		p.MaxUniStreamNum >= saved.MaxUniStreamNum &&
 		p.ActiveConnectionIDLimit == saved.ActiveConnectionIDLimit