From 10f9b2eb86839fd63bc9d1f93d4c7796c9ebb868 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sun, 8 Mar 2020 15:31:53 +0700
Subject: [PATCH] add an integration test that introduces packet reordering

---
 integrationtests/self/rtt_test.go | 89 ++++++++++++++++++++++---------
 1 file changed, 64 insertions(+), 25 deletions(-)

diff --git a/integrationtests/self/rtt_test.go b/integrationtests/self/rtt_test.go
index 6e0a2f5d..367713f7 100644
--- a/integrationtests/self/rtt_test.go
+++ b/integrationtests/self/rtt_test.go
@@ -19,38 +19,55 @@ var _ = Describe("non-zero RTT", func() {
 	for _, v := range protocol.SupportedVersions {
 		version := v
 
+		runServer := func() quic.Listener {
+			ln, err := quic.ListenAddr(
+				"localhost:0",
+				getTLSConfig(),
+				&quic.Config{
+					Versions: []protocol.VersionNumber{version},
+				},
+			)
+			Expect(err).ToNot(HaveOccurred())
+			go func() {
+				defer GinkgoRecover()
+				sess, err := ln.Accept(context.Background())
+				Expect(err).ToNot(HaveOccurred())
+				str, err := sess.OpenStream()
+				Expect(err).ToNot(HaveOccurred())
+				_, err = str.Write(PRData)
+				Expect(err).ToNot(HaveOccurred())
+				str.Close()
+			}()
+			return ln
+		}
+
+		downloadFile := func(port int) {
+			sess, err := quic.DialAddr(
+				fmt.Sprintf("localhost:%d", port),
+				getTLSClientConfig(),
+				&quic.Config{Versions: []protocol.VersionNumber{version}},
+			)
+			Expect(err).ToNot(HaveOccurred())
+			str, err := sess.AcceptStream(context.Background())
+			Expect(err).ToNot(HaveOccurred())
+			data, err := ioutil.ReadAll(str)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(data).To(Equal(PRData))
+			sess.CloseWithError(0, "")
+		}
+
 		Context(fmt.Sprintf("with QUIC version %s", version), func() {
-			roundTrips := [...]time.Duration{
+			for _, r := range [...]time.Duration{
 				10 * time.Millisecond,
 				50 * time.Millisecond,
 				100 * time.Millisecond,
 				200 * time.Millisecond,
-			}
-
-			for _, r := range roundTrips {
+			} {
 				rtt := r
 
 				It(fmt.Sprintf("downloads a message with %s RTT", rtt), func() {
-					ln, err := quic.ListenAddr(
-						"localhost:0",
-						getTLSConfig(),
-						&quic.Config{
-							Versions: []protocol.VersionNumber{version},
-						},
-					)
-					Expect(err).ToNot(HaveOccurred())
-					done := make(chan struct{})
-					go func() {
-						defer GinkgoRecover()
-						sess, err := ln.Accept(context.Background())
-						Expect(err).ToNot(HaveOccurred())
-						str, err := sess.OpenStream()
-						Expect(err).ToNot(HaveOccurred())
-						_, err = str.Write(PRData)
-						Expect(err).ToNot(HaveOccurred())
-						str.Close()
-						close(done)
-					}()
+					ln := runServer()
+					defer ln.Close()
 					serverPort := ln.Addr().(*net.UDPAddr).Port
 					proxy, err := quicproxy.NewQuicProxy("localhost:0", &quicproxy.Opts{
 						RemoteAddr: fmt.Sprintf("localhost:%d", serverPort),
@@ -73,7 +90,29 @@ var _ = Describe("non-zero RTT", func() {
 					Expect(err).ToNot(HaveOccurred())
 					Expect(data).To(Equal(PRData))
 					sess.CloseWithError(0, "")
-					Eventually(done).Should(BeClosed())
+				})
+			}
+
+			for _, r := range [...]time.Duration{
+				10 * time.Millisecond,
+				40 * time.Millisecond,
+			} {
+				rtt := r
+
+				It(fmt.Sprintf("downloads a message with %s RTT, with reordering", rtt), func() {
+					ln := runServer()
+					defer ln.Close()
+					serverPort := ln.Addr().(*net.UDPAddr).Port
+					proxy, err := quicproxy.NewQuicProxy("localhost:0", &quicproxy.Opts{
+						RemoteAddr: fmt.Sprintf("localhost:%d", serverPort),
+						DelayPacket: func(quicproxy.Direction, []byte) time.Duration {
+							return randomDuration(rtt/2, rtt*3/2) / 2
+						},
+					})
+					Expect(err).ToNot(HaveOccurred())
+					defer proxy.Close()
+
+					downloadFile(proxy.LocalPort())
 				})
 			}
 		})