From b215436dbb6de5d3366d67cbc2c73302d700e1b4 Mon Sep 17 00:00:00 2001
From: Maxime Piraux <maxime.piraux@uclouvain.be>
Date: Sat, 23 Mar 2019 17:11:51 +0100
Subject: [PATCH] Adds a spin bit test

---
 connection.go        |  5 +++-
 headers.go           | 10 +++++++
 scenarii/scenario.go |  1 +
 scenarii/spin_bit.go | 62 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 77 insertions(+), 1 deletion(-)
 create mode 100644 scenarii/spin_bit.go

diff --git a/connection.go b/connection.go
index ad1e5d9..fd2b08c 100644
--- a/connection.go
+++ b/connection.go
@@ -23,7 +23,10 @@ type Connection struct {
 
 	Tls           *pigotls.Connection
 	TLSTPHandler  *TLSTransportParameterHandler
-	KeyPhaseIndex uint
+
+	KeyPhaseIndex  uint
+	SpinBit   	   SpinBit
+	LastSpinNumber PacketNumber
 
 	CryptoStates   map[EncryptionLevel]*CryptoState
 
diff --git a/headers.go b/headers.go
index 9e3e9fe..0d7e416 100644
--- a/headers.go
+++ b/headers.go
@@ -149,6 +149,7 @@ func (t PacketType) PNSpace() PNSpace {
 }
 
 type ShortHeader struct {
+	SpinBit 	   SpinBit
 	KeyPhase       KeyPhaseBit
 	DestinationCID ConnectionID
 	truncatedPN    TruncatedPN
@@ -158,6 +159,9 @@ func (h *ShortHeader) Encode() []byte {
 	buffer := new(bytes.Buffer)
 	var typeByte uint8
 	typeByte |= 0x40
+	if h.SpinBit == SpinValueOne {
+		typeByte |= 0x20
+	}
 	if h.KeyPhase == KeyPhaseOne {
 		typeByte |= 0x04
 	}
@@ -177,6 +181,7 @@ func (h *ShortHeader) HeaderLength() int                     { return 1 + len(h.
 func ReadShortHeader(buffer *bytes.Reader, conn *Connection) *ShortHeader {
 	h := new(ShortHeader)
 	typeByte, _ := buffer.ReadByte()
+	h.SpinBit = (typeByte & 0x20) == 0x20
 	h.KeyPhase = (typeByte & 0x04) == 0x04
 
 	h.DestinationCID = make([]byte, len(conn.SourceCID))
@@ -187,6 +192,7 @@ func ReadShortHeader(buffer *bytes.Reader, conn *Connection) *ShortHeader {
 }
 func NewShortHeader(conn *Connection) *ShortHeader {
 	h := new(ShortHeader)
+	h.SpinBit = conn.SpinBit
 	h.KeyPhase = conn.KeyPhaseIndex % 2 == 1
 	h.DestinationCID = conn.DestinationCID
 	h.packetNumber = conn.nextPacketNumber(PNSpaceAppData)
@@ -197,3 +203,7 @@ func NewShortHeader(conn *Connection) *ShortHeader {
 type KeyPhaseBit bool
 const KeyPhaseZero KeyPhaseBit = false
 const KeyPhaseOne KeyPhaseBit = true
+
+type SpinBit bool
+const SpinValueZero SpinBit = false
+const SpinValueOne SpinBit = true
diff --git a/scenarii/scenario.go b/scenarii/scenario.go
index e6b09ee..a780c5e 100644
--- a/scenarii/scenario.go
+++ b/scenarii/scenario.go
@@ -124,5 +124,6 @@ func GetAllScenarii() map[string]Scenario {
 		"http3_encoder_stream":      NewHTTP3EncoderStreamScenario(),
 		"http3_uni_streams_limits":  NewHTTP3UniStreamsLimitsScenario(),
 		"http3_reserved_frames":     NewHTTP3ReservedFramesScenario(),
+		"spin_bit":     			 NewSpinBitScenario(),
 	}
 }
diff --git a/scenarii/spin_bit.go b/scenarii/spin_bit.go
new file mode 100644
index 0000000..55e0f06
--- /dev/null
+++ b/scenarii/spin_bit.go
@@ -0,0 +1,62 @@
+package scenarii
+
+import (
+	. "github.com/QUIC-Tracker/quic-tracker"
+)
+
+const (
+	SB_TLSHandshakeFailed = 1
+	SB_DoesNotSpin        = 2
+)
+
+type SpinBitScenario struct {
+	AbstractScenario
+}
+
+func NewSpinBitScenario() *SpinBitScenario {
+	return &SpinBitScenario{AbstractScenario{name: "spin_bit", version: 1, ipv6: false}}
+}
+func (s *SpinBitScenario) Run(conn *Connection, trace *Trace, preferredPath string, debug bool) {
+	connAgents := s.CompleteHandshake(conn, trace, SB_TLSHandshakeFailed)
+	if connAgents == nil {
+		return
+	}
+	defer connAgents.CloseConnection(false, 0, "")
+
+	incomingPackets := conn.IncomingPackets.RegisterNewChan(1000)
+
+	conn.SendHTTP09GETRequest(preferredPath, 0)
+
+	var lastServerSpin SpinBit
+	spins := 0
+
+forLoop:
+	for {
+		select {
+		case i := <-incomingPackets:
+			switch p := i.(type) {
+			case *ProtectedPacket:
+				hdr := p.Header().(*ShortHeader)
+				if hdr.PacketNumber() > conn.LastSpinNumber {
+					if hdr.SpinBit != lastServerSpin {
+						lastServerSpin = hdr.SpinBit
+						spins++
+					}
+					conn.SpinBit = !hdr.SpinBit
+					conn.LastSpinNumber = hdr.PacketNumber()
+				}
+				if conn.Streams.Get(0).ReadClosed && !conn.Streams.Get(4).WriteClosed {
+					conn.SendHTTP09GETRequest(preferredPath, 4)
+				}
+			}
+		case <-conn.ConnectionClosed:
+			break forLoop
+		case <-s.Timeout():
+			break forLoop
+		}
+	}
+
+	if spins <= 1 {
+		trace.ErrorCode = SB_DoesNotSpin
+	}
+}