/
sent_packet_handler_test.go
1386 lines (1258 loc) · 59.3 KB
/
sent_packet_handler_test.go
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package ackhandler
import (
"fmt"
"time"
"github.com/golang/mock/gomock"
"github.com/lucas-clemente/quic-go/internal/mocks"
"github.com/lucas-clemente/quic-go/internal/protocol"
"github.com/lucas-clemente/quic-go/internal/qerr"
"github.com/lucas-clemente/quic-go/internal/utils"
"github.com/lucas-clemente/quic-go/internal/wire"
. "github.com/onsi/ginkgo"
. "github.com/onsi/gomega"
)
var _ = Describe("SentPacketHandler", func() {
var (
handler *sentPacketHandler
streamFrame wire.StreamFrame
lostPackets []protocol.PacketNumber
perspective protocol.Perspective
)
BeforeEach(func() { perspective = protocol.PerspectiveServer })
JustBeforeEach(func() {
lostPackets = nil
rttStats := utils.NewRTTStats()
handler = newSentPacketHandler(42, protocol.InitialPacketSizeIPv4, rttStats, perspective, nil, utils.DefaultLogger)
streamFrame = wire.StreamFrame{
StreamID: 5,
Data: []byte{0x13, 0x37},
}
})
getPacket := func(pn protocol.PacketNumber, encLevel protocol.EncryptionLevel) *Packet {
if el, ok := handler.getPacketNumberSpace(encLevel).history.packetMap[pn]; ok {
return &el.Value
}
return nil
}
ackElicitingPacket := func(p *Packet) *Packet {
if p.EncryptionLevel == 0 {
p.EncryptionLevel = protocol.Encryption1RTT
}
if p.Length == 0 {
p.Length = 1
}
if p.SendTime.IsZero() {
p.SendTime = time.Now()
}
if len(p.Frames) == 0 {
p.Frames = []Frame{
{Frame: &wire.PingFrame{}, OnLost: func(wire.Frame) { lostPackets = append(lostPackets, p.PacketNumber) }},
}
}
return p
}
nonAckElicitingPacket := func(p *Packet) *Packet {
p = ackElicitingPacket(p)
p.Frames = nil
p.LargestAcked = 1
return p
}
initialPacket := func(p *Packet) *Packet {
p = ackElicitingPacket(p)
p.EncryptionLevel = protocol.EncryptionInitial
return p
}
handshakePacket := func(p *Packet) *Packet {
p = ackElicitingPacket(p)
p.EncryptionLevel = protocol.EncryptionHandshake
return p
}
handshakePacketNonAckEliciting := func(p *Packet) *Packet {
p = nonAckElicitingPacket(p)
p.EncryptionLevel = protocol.EncryptionHandshake
return p
}
expectInPacketHistory := func(expected []protocol.PacketNumber, encLevel protocol.EncryptionLevel) {
pnSpace := handler.getPacketNumberSpace(encLevel)
var length int
pnSpace.history.Iterate(func(p *Packet) (bool, error) {
if !p.declaredLost && !p.skippedPacket {
length++
}
return true, nil
})
ExpectWithOffset(1, length).To(Equal(len(expected)))
for _, p := range expected {
ExpectWithOffset(2, pnSpace.history.packetMap).To(HaveKey(p))
}
}
updateRTT := func(rtt time.Duration) {
handler.rttStats.UpdateRTT(rtt, 0, time.Now())
ExpectWithOffset(1, handler.rttStats.SmoothedRTT()).To(Equal(rtt))
}
Context("registering sent packets", func() {
It("accepts two consecutive packets", func() {
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, EncryptionLevel: protocol.EncryptionHandshake}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 2, EncryptionLevel: protocol.EncryptionHandshake}))
Expect(handler.handshakePackets.largestSent).To(Equal(protocol.PacketNumber(2)))
expectInPacketHistory([]protocol.PacketNumber{1, 2}, protocol.EncryptionHandshake)
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(2)))
})
It("uses the same packet number space for 0-RTT and 1-RTT packets", func() {
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, EncryptionLevel: protocol.Encryption0RTT}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 2, EncryptionLevel: protocol.Encryption1RTT}))
Expect(handler.appDataPackets.largestSent).To(Equal(protocol.PacketNumber(2)))
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(2)))
})
It("accepts packet number 0", func() {
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 0, EncryptionLevel: protocol.Encryption1RTT}))
Expect(handler.appDataPackets.largestSent).To(BeZero())
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, EncryptionLevel: protocol.Encryption1RTT}))
Expect(handler.appDataPackets.largestSent).To(Equal(protocol.PacketNumber(1)))
expectInPacketHistory([]protocol.PacketNumber{0, 1}, protocol.Encryption1RTT)
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(2)))
})
It("stores the sent time", func() {
sendTime := time.Now().Add(-time.Minute)
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, SendTime: sendTime}))
Expect(handler.appDataPackets.lastAckElicitingPacketTime).To(Equal(sendTime))
})
It("stores the sent time of Initial packets", func() {
sendTime := time.Now().Add(-time.Minute)
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, SendTime: sendTime, EncryptionLevel: protocol.EncryptionInitial}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 2, SendTime: sendTime.Add(time.Hour), EncryptionLevel: protocol.Encryption1RTT}))
Expect(handler.initialPackets.lastAckElicitingPacketTime).To(Equal(sendTime))
})
})
Context("ACK processing", func() {
JustBeforeEach(func() {
for i := protocol.PacketNumber(0); i < 10; i++ {
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: i}))
}
// Increase RTT, because the tests would be flaky otherwise
updateRTT(time.Hour)
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(10)))
})
Context("ACK processing", func() {
It("accepts ACKs sent in packet 0", func() {
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 0, Largest: 5}}}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.appDataPackets.largestAcked).To(Equal(protocol.PacketNumber(5)))
})
It("says if a 1-RTT packet was acknowledged", func() {
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 100, EncryptionLevel: protocol.Encryption0RTT}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 101, EncryptionLevel: protocol.Encryption0RTT}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 102, EncryptionLevel: protocol.Encryption1RTT}))
acked1RTT, err := handler.ReceivedAck(
&wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 100, Largest: 101}}},
protocol.Encryption1RTT,
time.Now(),
)
Expect(err).ToNot(HaveOccurred())
Expect(acked1RTT).To(BeFalse())
acked1RTT, err = handler.ReceivedAck(
&wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 101, Largest: 102}}},
protocol.Encryption1RTT,
time.Now(),
)
Expect(err).ToNot(HaveOccurred())
Expect(acked1RTT).To(BeTrue())
})
It("accepts multiple ACKs sent in the same packet", func() {
ack1 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 0, Largest: 3}}}
ack2 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 0, Largest: 4}}}
_, err := handler.ReceivedAck(ack1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.appDataPackets.largestAcked).To(Equal(protocol.PacketNumber(3)))
// this wouldn't happen in practice
// for testing purposes, we pretend send a different ACK frame in a duplicated packet, to be able to verify that it actually doesn't get processed
_, err = handler.ReceivedAck(ack2, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.appDataPackets.largestAcked).To(Equal(protocol.PacketNumber(4)))
})
It("rejects ACKs that acknowledge a skipped packet number", func() {
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 100}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 102}))
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 100, Largest: 102}}}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).To(MatchError(&qerr.TransportError{
ErrorCode: qerr.ProtocolViolation,
ErrorMessage: "received an ACK for skipped packet number: 101 (1-RTT)",
}))
})
It("rejects ACKs with a too high LargestAcked packet number", func() {
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 0, Largest: 9999}}}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).To(MatchError(&qerr.TransportError{
ErrorCode: qerr.ProtocolViolation,
ErrorMessage: "received ACK for an unsent packet",
}))
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(10)))
})
It("ignores repeated ACKs", func() {
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 0, Largest: 3}}}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(6)))
_, err = handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.appDataPackets.largestAcked).To(Equal(protocol.PacketNumber(3)))
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(6)))
})
})
Context("acks the right packets", func() {
expectInPacketHistoryOrLost := func(expected []protocol.PacketNumber, encLevel protocol.EncryptionLevel) {
pnSpace := handler.getPacketNumberSpace(encLevel)
var length int
pnSpace.history.Iterate(func(p *Packet) (bool, error) {
if !p.declaredLost {
length++
}
return true, nil
})
ExpectWithOffset(1, length+len(lostPackets)).To(Equal(len(expected)))
expectedLoop:
for _, p := range expected {
if _, ok := pnSpace.history.packetMap[p]; ok {
continue
}
for _, lostP := range lostPackets {
if lostP == p {
continue expectedLoop
}
}
Fail(fmt.Sprintf("Packet %d not in packet history.", p))
}
}
It("adjusts the LargestAcked, and adjusts the bytes in flight", func() {
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 0, Largest: 5}}}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.appDataPackets.largestAcked).To(Equal(protocol.PacketNumber(5)))
expectInPacketHistoryOrLost([]protocol.PacketNumber{6, 7, 8, 9}, protocol.Encryption1RTT)
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(4)))
})
It("acks packet 0", func() {
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 0, Largest: 0}}}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(getPacket(0, protocol.Encryption1RTT)).To(BeNil())
expectInPacketHistoryOrLost([]protocol.PacketNumber{1, 2, 3, 4, 5, 6, 7, 8, 9}, protocol.Encryption1RTT)
})
It("calls the OnAcked callback", func() {
var acked bool
ping := &wire.PingFrame{}
handler.SentPacket(ackElicitingPacket(&Packet{
PacketNumber: 13,
Frames: []Frame{{
Frame: ping, OnAcked: func(f wire.Frame) {
Expect(f).To(Equal(ping))
acked = true
},
}},
}))
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 13, Largest: 13}}}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(acked).To(BeTrue())
})
It("handles an ACK frame with one missing packet range", func() {
ack := &wire.AckFrame{ // lose 4 and 5
AckRanges: []wire.AckRange{
{Smallest: 6, Largest: 9},
{Smallest: 1, Largest: 3},
},
}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
expectInPacketHistoryOrLost([]protocol.PacketNumber{0, 4, 5}, protocol.Encryption1RTT)
})
It("does not ack packets below the LowestAcked", func() {
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 3, Largest: 8}}}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
expectInPacketHistoryOrLost([]protocol.PacketNumber{0, 1, 2, 9}, protocol.Encryption1RTT)
})
It("handles an ACK with multiple missing packet ranges", func() {
ack := &wire.AckFrame{ // packets 2, 4 and 5, and 8 were lost
AckRanges: []wire.AckRange{
{Smallest: 9, Largest: 9},
{Smallest: 6, Largest: 7},
{Smallest: 3, Largest: 3},
{Smallest: 1, Largest: 1},
},
}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
expectInPacketHistoryOrLost([]protocol.PacketNumber{0, 2, 4, 5, 8}, protocol.Encryption1RTT)
})
It("processes an ACK frame that would be sent after a late arrival of a packet", func() {
ack1 := &wire.AckFrame{ // 5 lost
AckRanges: []wire.AckRange{
{Smallest: 6, Largest: 6},
{Smallest: 1, Largest: 4},
},
}
_, err := handler.ReceivedAck(ack1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
expectInPacketHistoryOrLost([]protocol.PacketNumber{0, 5, 7, 8, 9}, protocol.Encryption1RTT)
ack2 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 6}}} // now ack 5
_, err = handler.ReceivedAck(ack2, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
expectInPacketHistoryOrLost([]protocol.PacketNumber{0, 7, 8, 9}, protocol.Encryption1RTT)
})
It("processes an ACK that contains old ACK ranges", func() {
ack1 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 6}}}
_, err := handler.ReceivedAck(ack1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
expectInPacketHistoryOrLost([]protocol.PacketNumber{0, 7, 8, 9}, protocol.Encryption1RTT)
ack2 := &wire.AckFrame{
AckRanges: []wire.AckRange{
{Smallest: 8, Largest: 8},
{Smallest: 3, Largest: 3},
{Smallest: 1, Largest: 1},
},
}
_, err = handler.ReceivedAck(ack2, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
expectInPacketHistoryOrLost([]protocol.PacketNumber{0, 7, 9}, protocol.Encryption1RTT)
})
})
Context("calculating RTT", func() {
It("computes the RTT", func() {
now := time.Now()
// First, fake the sent times of the first, second and last packet
getPacket(1, protocol.Encryption1RTT).SendTime = now.Add(-10 * time.Minute)
getPacket(2, protocol.Encryption1RTT).SendTime = now.Add(-5 * time.Minute)
getPacket(6, protocol.Encryption1RTT).SendTime = now.Add(-1 * time.Minute)
// Now, check that the proper times are used when calculating the deltas
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 1}}}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.rttStats.LatestRTT()).To(BeNumerically("~", 10*time.Minute, 1*time.Second))
ack = &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 2}}}
_, err = handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.rttStats.LatestRTT()).To(BeNumerically("~", 5*time.Minute, 1*time.Second))
ack = &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 6}}}
_, err = handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.rttStats.LatestRTT()).To(BeNumerically("~", 1*time.Minute, 1*time.Second))
})
It("ignores the DelayTime for Initial and Handshake packets", func() {
handler.SentPacket(initialPacket(&Packet{PacketNumber: 1}))
handler.rttStats.SetMaxAckDelay(time.Hour)
// make sure the rttStats have a min RTT, so that the delay is used
handler.rttStats.UpdateRTT(5*time.Minute, 0, time.Now())
getPacket(1, protocol.EncryptionInitial).SendTime = time.Now().Add(-10 * time.Minute)
ack := &wire.AckFrame{
AckRanges: []wire.AckRange{{Smallest: 1, Largest: 1}},
DelayTime: 5 * time.Minute,
}
_, err := handler.ReceivedAck(ack, protocol.EncryptionInitial, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.rttStats.LatestRTT()).To(BeNumerically("~", 10*time.Minute, 1*time.Second))
})
It("uses the DelayTime in the ACK frame", func() {
handler.rttStats.SetMaxAckDelay(time.Hour)
// make sure the rttStats have a min RTT, so that the delay is used
handler.rttStats.UpdateRTT(5*time.Minute, 0, time.Now())
getPacket(1, protocol.Encryption1RTT).SendTime = time.Now().Add(-10 * time.Minute)
ack := &wire.AckFrame{
AckRanges: []wire.AckRange{{Smallest: 1, Largest: 1}},
DelayTime: 5 * time.Minute,
}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.rttStats.LatestRTT()).To(BeNumerically("~", 5*time.Minute, 1*time.Second))
})
It("limits the DelayTime in the ACK frame to max_ack_delay", func() {
handler.rttStats.SetMaxAckDelay(time.Minute)
// make sure the rttStats have a min RTT, so that the delay is used
handler.rttStats.UpdateRTT(5*time.Minute, 0, time.Now())
getPacket(1, protocol.Encryption1RTT).SendTime = time.Now().Add(-10 * time.Minute)
ack := &wire.AckFrame{
AckRanges: []wire.AckRange{{Smallest: 1, Largest: 1}},
DelayTime: 5 * time.Minute,
}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.rttStats.LatestRTT()).To(BeNumerically("~", 9*time.Minute, 1*time.Second))
})
})
Context("determining which ACKs we have received an ACK for", func() {
JustBeforeEach(func() {
morePackets := []*Packet{
{
PacketNumber: 13,
LargestAcked: 100,
Frames: []Frame{{Frame: &streamFrame, OnLost: func(wire.Frame) {}}},
Length: 1,
EncryptionLevel: protocol.Encryption1RTT,
},
{
PacketNumber: 14,
LargestAcked: 200,
Frames: []Frame{{Frame: &streamFrame, OnLost: func(wire.Frame) {}}},
Length: 1,
EncryptionLevel: protocol.Encryption1RTT,
},
{
PacketNumber: 15,
Frames: []Frame{{Frame: &streamFrame, OnLost: func(wire.Frame) {}}},
Length: 1,
EncryptionLevel: protocol.Encryption1RTT,
},
}
for _, packet := range morePackets {
handler.SentPacket(packet)
}
})
It("determines which ACK we have received an ACK for", func() {
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 13, Largest: 15}}}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.GetLowestPacketNotConfirmedAcked()).To(Equal(protocol.PacketNumber(201)))
})
It("doesn't do anything when the acked packet didn't contain an ACK", func() {
ack1 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 13, Largest: 13}}}
ack2 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 15, Largest: 15}}}
_, err := handler.ReceivedAck(ack1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.GetLowestPacketNotConfirmedAcked()).To(Equal(protocol.PacketNumber(101)))
_, err = handler.ReceivedAck(ack2, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.GetLowestPacketNotConfirmedAcked()).To(Equal(protocol.PacketNumber(101)))
})
It("doesn't decrease the value", func() {
ack1 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 14, Largest: 14}}}
ack2 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 13, Largest: 13}}}
_, err := handler.ReceivedAck(ack1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.GetLowestPacketNotConfirmedAcked()).To(Equal(protocol.PacketNumber(201)))
_, err = handler.ReceivedAck(ack2, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.GetLowestPacketNotConfirmedAcked()).To(Equal(protocol.PacketNumber(201)))
})
})
})
Context("congestion", func() {
var cong *mocks.MockSendAlgorithmWithDebugInfos
JustBeforeEach(func() {
cong = mocks.NewMockSendAlgorithmWithDebugInfos(mockCtrl)
handler.congestion = cong
})
It("should call OnSent", func() {
cong.EXPECT().OnPacketSent(
gomock.Any(),
protocol.ByteCount(42),
protocol.PacketNumber(1),
protocol.ByteCount(42),
true,
)
handler.SentPacket(&Packet{
PacketNumber: 1,
Length: 42,
Frames: []Frame{{Frame: &wire.PingFrame{}, OnLost: func(wire.Frame) {}}},
EncryptionLevel: protocol.Encryption1RTT,
})
})
It("should call MaybeExitSlowStart and OnPacketAcked", func() {
rcvTime := time.Now().Add(-5 * time.Second)
cong.EXPECT().OnPacketSent(gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any()).Times(3)
gomock.InOrder(
cong.EXPECT().MaybeExitSlowStart(), // must be called before packets are acked
cong.EXPECT().OnPacketAcked(protocol.PacketNumber(1), protocol.ByteCount(1), protocol.ByteCount(3), rcvTime),
cong.EXPECT().OnPacketAcked(protocol.PacketNumber(2), protocol.ByteCount(1), protocol.ByteCount(3), rcvTime),
)
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 2}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 3}))
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 2}}}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, rcvTime)
Expect(err).ToNot(HaveOccurred())
})
It("doesn't call OnPacketAcked when a retransmitted packet is acked", func() {
cong.EXPECT().OnPacketSent(gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any()).Times(2)
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 2}))
// lose packet 1
gomock.InOrder(
cong.EXPECT().MaybeExitSlowStart(),
cong.EXPECT().OnPacketLost(protocol.PacketNumber(1), protocol.ByteCount(1), protocol.ByteCount(2)),
cong.EXPECT().OnPacketAcked(protocol.PacketNumber(2), protocol.ByteCount(1), protocol.ByteCount(2), gomock.Any()),
)
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 2, Largest: 2}}}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
// don't EXPECT any further calls to the congestion controller
ack = &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 2}}}
_, err = handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
})
It("doesn't call OnPacketLost when a Path MTU probe packet is lost", func() {
cong.EXPECT().OnPacketSent(gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any()).Times(2)
var mtuPacketDeclaredLost bool
handler.SentPacket(ackElicitingPacket(&Packet{
PacketNumber: 1,
SendTime: time.Now().Add(-time.Hour),
IsPathMTUProbePacket: true,
Frames: []Frame{{Frame: &wire.PingFrame{}, OnLost: func(wire.Frame) { mtuPacketDeclaredLost = true }}},
}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 2}))
// lose packet 1, but don't EXPECT any calls to OnPacketLost()
gomock.InOrder(
cong.EXPECT().MaybeExitSlowStart(),
cong.EXPECT().OnPacketAcked(protocol.PacketNumber(2), protocol.ByteCount(1), protocol.ByteCount(2), gomock.Any()),
)
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 2, Largest: 2}}}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(mtuPacketDeclaredLost).To(BeTrue())
Expect(handler.bytesInFlight).To(BeZero())
})
It("calls OnPacketAcked and OnPacketLost with the right bytes_in_flight value", func() {
cong.EXPECT().OnPacketSent(gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any()).Times(4)
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 2, SendTime: time.Now().Add(-30 * time.Minute)}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 3, SendTime: time.Now().Add(-30 * time.Minute)}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 4, SendTime: time.Now()}))
// receive the first ACK
gomock.InOrder(
cong.EXPECT().MaybeExitSlowStart(),
cong.EXPECT().OnPacketLost(protocol.PacketNumber(1), protocol.ByteCount(1), protocol.ByteCount(4)),
cong.EXPECT().OnPacketAcked(protocol.PacketNumber(2), protocol.ByteCount(1), protocol.ByteCount(4), gomock.Any()),
)
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 2, Largest: 2}}}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now().Add(-30*time.Minute))
Expect(err).ToNot(HaveOccurred())
// receive the second ACK
gomock.InOrder(
cong.EXPECT().MaybeExitSlowStart(),
cong.EXPECT().OnPacketLost(protocol.PacketNumber(3), protocol.ByteCount(1), protocol.ByteCount(2)),
cong.EXPECT().OnPacketAcked(protocol.PacketNumber(4), protocol.ByteCount(1), protocol.ByteCount(2), gomock.Any()),
)
ack = &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 4, Largest: 4}}}
_, err = handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
})
It("passes the bytes in flight to the congestion controller", func() {
handler.ReceivedPacket(protocol.EncryptionHandshake)
cong.EXPECT().OnPacketSent(gomock.Any(), protocol.ByteCount(42), gomock.Any(), protocol.ByteCount(42), true)
handler.SentPacket(&Packet{
Length: 42,
EncryptionLevel: protocol.EncryptionInitial,
Frames: []Frame{{Frame: &wire.PingFrame{}}},
SendTime: time.Now(),
})
cong.EXPECT().CanSend(protocol.ByteCount(42)).Return(true)
handler.SendMode()
})
It("allows sending of ACKs when congestion limited", func() {
handler.ReceivedPacket(protocol.EncryptionHandshake)
cong.EXPECT().CanSend(gomock.Any()).Return(true)
Expect(handler.SendMode()).To(Equal(SendAny))
cong.EXPECT().CanSend(gomock.Any()).Return(false)
Expect(handler.SendMode()).To(Equal(SendAck))
})
It("allows sending of ACKs when we're keeping track of MaxOutstandingSentPackets packets", func() {
handler.ReceivedPacket(protocol.EncryptionHandshake)
cong.EXPECT().CanSend(gomock.Any()).Return(true).AnyTimes()
cong.EXPECT().OnPacketSent(gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any()).AnyTimes()
for i := protocol.PacketNumber(0); i < protocol.MaxOutstandingSentPackets; i++ {
Expect(handler.SendMode()).To(Equal(SendAny))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: i}))
}
Expect(handler.SendMode()).To(Equal(SendAck))
})
It("allows PTOs, even when congestion limited", func() {
handler.ReceivedPacket(protocol.EncryptionHandshake)
// note that we don't EXPECT a call to GetCongestionWindow
// that means retransmissions are sent without considering the congestion window
handler.numProbesToSend = 1
handler.ptoMode = SendPTOHandshake
Expect(handler.SendMode()).To(Equal(SendPTOHandshake))
})
It("says if it has pacing budget", func() {
cong.EXPECT().HasPacingBudget().Return(true)
Expect(handler.HasPacingBudget()).To(BeTrue())
cong.EXPECT().HasPacingBudget().Return(false)
Expect(handler.HasPacingBudget()).To(BeFalse())
})
It("returns the pacing delay", func() {
t := time.Now()
cong.EXPECT().TimeUntilSend(gomock.Any()).Return(t)
Expect(handler.TimeUntilSend()).To(Equal(t))
})
})
It("doesn't set an alarm if there are no outstanding packets", func() {
handler.ReceivedPacket(protocol.EncryptionHandshake)
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 10}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 11}))
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 10, Largest: 11}}}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.GetLossDetectionTimeout()).To(BeZero())
})
It("does nothing on OnAlarm if there are no outstanding packets", func() {
handler.ReceivedPacket(protocol.EncryptionHandshake)
Expect(handler.OnLossDetectionTimeout()).To(Succeed())
Expect(handler.SendMode()).To(Equal(SendAny))
})
Context("probe packets", func() {
It("queues a probe packet", func() {
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 10}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 11}))
queued := handler.QueueProbePacket(protocol.Encryption1RTT)
Expect(queued).To(BeTrue())
Expect(lostPackets).To(Equal([]protocol.PacketNumber{10}))
})
It("says when it can't queue a probe packet", func() {
queued := handler.QueueProbePacket(protocol.Encryption1RTT)
Expect(queued).To(BeFalse())
})
It("implements exponential backoff", func() {
handler.peerAddressValidated = true
handler.SetHandshakeConfirmed()
sendTime := time.Now().Add(-time.Hour)
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, SendTime: sendTime}))
timeout := handler.GetLossDetectionTimeout().Sub(sendTime)
Expect(handler.GetLossDetectionTimeout().Sub(sendTime)).To(Equal(timeout))
handler.ptoCount = 1
handler.setLossDetectionTimer()
Expect(handler.GetLossDetectionTimeout().Sub(sendTime)).To(Equal(2 * timeout))
handler.ptoCount = 2
handler.setLossDetectionTimer()
Expect(handler.GetLossDetectionTimeout().Sub(sendTime)).To(Equal(4 * timeout))
})
It("reset the PTO count when receiving an ACK", func() {
handler.ReceivedPacket(protocol.EncryptionHandshake)
now := time.Now()
handler.SetHandshakeConfirmed()
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, SendTime: now.Add(-time.Minute)}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 2, SendTime: now.Add(-time.Minute)}))
Expect(handler.GetLossDetectionTimeout()).To(BeTemporally("~", now.Add(-time.Minute), time.Second))
Expect(handler.OnLossDetectionTimeout()).To(Succeed())
Expect(handler.SendMode()).To(Equal(SendPTOAppData))
Expect(handler.ptoCount).To(BeEquivalentTo(1))
_, err := handler.ReceivedAck(&wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 1}}}, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.ptoCount).To(BeZero())
})
It("resets the PTO mode and PTO count when a packet number space is dropped", func() {
handler.ReceivedPacket(protocol.EncryptionHandshake)
now := time.Now()
handler.rttStats.UpdateRTT(time.Second/2, 0, now)
Expect(handler.rttStats.SmoothedRTT()).To(Equal(time.Second / 2))
Expect(handler.rttStats.PTO(true)).To(And(
BeNumerically(">", time.Second),
BeNumerically("<", 2*time.Second),
))
sendTimeHandshake := now.Add(-2 * time.Minute)
sendTimeAppData := now.Add(-time.Minute)
handler.SentPacket(ackElicitingPacket(&Packet{
PacketNumber: 1,
EncryptionLevel: protocol.EncryptionHandshake,
SendTime: sendTimeHandshake,
}))
handler.SentPacket(ackElicitingPacket(&Packet{
PacketNumber: 2,
SendTime: sendTimeAppData,
}))
// PTO timer based on the Handshake packet
Expect(handler.OnLossDetectionTimeout()).To(Succeed())
Expect(handler.ptoCount).To(BeEquivalentTo(1))
Expect(handler.SendMode()).To(Equal(SendPTOHandshake))
Expect(handler.GetLossDetectionTimeout()).To(Equal(sendTimeHandshake.Add(handler.rttStats.PTO(false) << 1)))
handler.SetHandshakeConfirmed()
handler.DropPackets(protocol.EncryptionHandshake)
// PTO timer based on the 1-RTT packet
Expect(handler.GetLossDetectionTimeout()).To(Equal(sendTimeAppData.Add(handler.rttStats.PTO(true)))) // no backoff. PTO count = 0
Expect(handler.SendMode()).ToNot(Equal(SendPTOHandshake))
Expect(handler.ptoCount).To(BeZero())
})
It("allows two 1-RTT PTOs", func() {
handler.ReceivedPacket(protocol.EncryptionHandshake)
handler.SetHandshakeConfirmed()
var lostPackets []protocol.PacketNumber
handler.SentPacket(ackElicitingPacket(&Packet{
PacketNumber: 1,
SendTime: time.Now().Add(-time.Hour),
Frames: []Frame{
{Frame: &wire.PingFrame{}, OnLost: func(wire.Frame) { lostPackets = append(lostPackets, 1) }},
},
}))
Expect(handler.OnLossDetectionTimeout()).To(Succeed())
Expect(handler.SendMode()).To(Equal(SendPTOAppData))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 2}))
Expect(handler.SendMode()).To(Equal(SendPTOAppData))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 3}))
Expect(handler.SendMode()).ToNot(Equal(SendPTOAppData))
})
It("skips a packet number for 1-RTT PTOs", func() {
handler.ReceivedPacket(protocol.EncryptionHandshake)
handler.SetHandshakeConfirmed()
var lostPackets []protocol.PacketNumber
pn := handler.PopPacketNumber(protocol.Encryption1RTT)
handler.SentPacket(ackElicitingPacket(&Packet{
PacketNumber: pn,
SendTime: time.Now().Add(-time.Hour),
Frames: []Frame{
{Frame: &wire.PingFrame{}, OnLost: func(wire.Frame) { lostPackets = append(lostPackets, 1) }},
},
}))
Expect(handler.OnLossDetectionTimeout()).To(Succeed())
Expect(handler.SendMode()).To(Equal(SendPTOAppData))
// The packet number generator might have introduced another skipped a packet number.
Expect(handler.PopPacketNumber(protocol.Encryption1RTT)).To(BeNumerically(">=", pn+2))
})
It("only counts ack-eliciting packets as probe packets", func() {
handler.ReceivedPacket(protocol.EncryptionHandshake)
handler.SetHandshakeConfirmed()
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
Expect(handler.OnLossDetectionTimeout()).To(Succeed())
Expect(handler.SendMode()).To(Equal(SendPTOAppData))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 2}))
Expect(handler.SendMode()).To(Equal(SendPTOAppData))
for p := protocol.PacketNumber(3); p < 30; p++ {
handler.SentPacket(nonAckElicitingPacket(&Packet{PacketNumber: p}))
Expect(handler.SendMode()).To(Equal(SendPTOAppData))
}
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 30}))
Expect(handler.SendMode()).ToNot(Equal(SendPTOAppData))
})
It("gets two probe packets if PTO expires", func() {
handler.ReceivedPacket(protocol.EncryptionHandshake)
handler.SetHandshakeConfirmed()
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 2}))
updateRTT(time.Hour)
Expect(handler.appDataPackets.lossTime.IsZero()).To(BeTrue())
Expect(handler.OnLossDetectionTimeout()).To(Succeed()) // TLP
Expect(handler.ptoCount).To(BeEquivalentTo(1))
Expect(handler.SendMode()).To(Equal(SendPTOAppData))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 3}))
Expect(handler.SendMode()).To(Equal(SendPTOAppData))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 4}))
Expect(handler.OnLossDetectionTimeout()).To(Succeed()) // PTO
Expect(handler.ptoCount).To(BeEquivalentTo(2))
Expect(handler.SendMode()).To(Equal(SendPTOAppData))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 5}))
Expect(handler.SendMode()).To(Equal(SendPTOAppData))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 6}))
Expect(handler.SendMode()).To(Equal(SendAny))
})
It("gets two probe packets if PTO expires, for Handshake packets", func() {
handler.ReceivedPacket(protocol.EncryptionHandshake)
handler.SentPacket(initialPacket(&Packet{PacketNumber: 1}))
handler.SentPacket(initialPacket(&Packet{PacketNumber: 2}))
updateRTT(time.Hour)
Expect(handler.initialPackets.lossTime.IsZero()).To(BeTrue())
Expect(handler.OnLossDetectionTimeout()).To(Succeed())
Expect(handler.SendMode()).To(Equal(SendPTOInitial))
handler.SentPacket(initialPacket(&Packet{PacketNumber: 3}))
Expect(handler.SendMode()).To(Equal(SendPTOInitial))
handler.SentPacket(initialPacket(&Packet{PacketNumber: 4}))
Expect(handler.SendMode()).To(Equal(SendAny))
})
It("doesn't send 1-RTT probe packets before the handshake completes", func() {
handler.ReceivedPacket(protocol.EncryptionHandshake)
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1}))
updateRTT(time.Hour)
Expect(handler.OnLossDetectionTimeout()).To(Succeed())
Expect(handler.GetLossDetectionTimeout()).To(BeZero())
Expect(handler.SendMode()).To(Equal(SendAny))
handler.SetHandshakeConfirmed()
Expect(handler.GetLossDetectionTimeout()).ToNot(BeZero())
Expect(handler.OnLossDetectionTimeout()).To(Succeed())
Expect(handler.SendMode()).To(Equal(SendPTOAppData))
})
It("resets the send mode when it receives an acknowledgement after queueing probe packets", func() {
handler.ReceivedPacket(protocol.EncryptionHandshake)
handler.SetHandshakeConfirmed()
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
updateRTT(time.Second)
Expect(handler.OnLossDetectionTimeout()).To(Succeed())
Expect(handler.SendMode()).To(Equal(SendPTOAppData))
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 1}}}
_, err := handler.ReceivedAck(ack, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.SendMode()).To(Equal(SendAny))
})
It("handles ACKs for the original packet", func() {
handler.ReceivedPacket(protocol.EncryptionHandshake)
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 5, SendTime: time.Now().Add(-time.Hour)}))
updateRTT(time.Second)
Expect(handler.OnLossDetectionTimeout()).To(Succeed())
Expect(handler.OnLossDetectionTimeout()).To(Succeed())
})
It("doesn't set the PTO timer for Path MTU probe packets", func() {
handler.ReceivedPacket(protocol.EncryptionHandshake)
handler.SetHandshakeConfirmed()
updateRTT(time.Second)
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 5, SendTime: time.Now(), IsPathMTUProbePacket: true}))
Expect(handler.GetLossDetectionTimeout()).To(BeZero())
})
})
Context("amplification limit, for the server", func() {
It("limits the window to 3x the bytes received, to avoid amplification attacks", func() {
handler.ReceivedPacket(protocol.EncryptionInitial) // receiving an Initial packet doesn't validate the client's address
handler.ReceivedBytes(200)
handler.SentPacket(&Packet{
PacketNumber: 1,
Length: 599,
EncryptionLevel: protocol.EncryptionInitial,
Frames: []Frame{{Frame: &wire.PingFrame{}}},
SendTime: time.Now(),
})
Expect(handler.SendMode()).To(Equal(SendAny))
handler.SentPacket(&Packet{
PacketNumber: 2,
Length: 1,
EncryptionLevel: protocol.EncryptionInitial,
Frames: []Frame{{Frame: &wire.PingFrame{}}},
SendTime: time.Now(),
})
Expect(handler.SendMode()).To(Equal(SendNone))
})
It("cancels the loss detection timer when it is amplification limited, and resets it when becoming unblocked", func() {
handler.ReceivedBytes(300)
handler.SentPacket(&Packet{
PacketNumber: 1,
Length: 900,
EncryptionLevel: protocol.EncryptionInitial,
Frames: []Frame{{Frame: &wire.PingFrame{}}},
SendTime: time.Now(),
})
// Amplification limited. We don't need to set a timer now.
Expect(handler.GetLossDetectionTimeout()).To(BeZero())
// Unblock the server. Now we should fire up the timer.
handler.ReceivedBytes(1)
Expect(handler.GetLossDetectionTimeout()).ToNot(BeZero())
})
It("resets the loss detection timer when the client's address is validated", func() {
handler.ReceivedBytes(300)
handler.SentPacket(&Packet{
PacketNumber: 1,
Length: 900,
EncryptionLevel: protocol.EncryptionHandshake,
Frames: []Frame{{Frame: &wire.PingFrame{}}},
SendTime: time.Now(),
})
// Amplification limited. We don't need to set a timer now.
Expect(handler.GetLossDetectionTimeout()).To(BeZero())
handler.ReceivedPacket(protocol.EncryptionHandshake)
Expect(handler.GetLossDetectionTimeout()).ToNot(BeZero())
})
It("cancels the loss detection alarm when all Handshake packets are acknowledged", func() {
t := time.Now().Add(-time.Second)
handler.ReceivedBytes(99999)
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 2, SendTime: t}))
handler.SentPacket(handshakePacket(&Packet{PacketNumber: 3, SendTime: t}))
handler.SentPacket(handshakePacket(&Packet{PacketNumber: 4, SendTime: t}))
Expect(handler.GetLossDetectionTimeout()).ToNot(BeZero())
handler.ReceivedAck(&wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 3, Largest: 4}}}, protocol.EncryptionHandshake, time.Now())
Expect(handler.GetLossDetectionTimeout()).To(BeZero())
})
})
Context("amplification limit, for the client", func() {
BeforeEach(func() {
perspective = protocol.PerspectiveClient
})
It("sends an Initial packet to unblock the server", func() {
handler.SentPacket(initialPacket(&Packet{PacketNumber: 1}))
_, err := handler.ReceivedAck(
&wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 1}}},
protocol.EncryptionInitial,
time.Now(),
)
Expect(err).ToNot(HaveOccurred())
// No packets are outstanding at this point.
// Make sure that a probe packet is sent.
Expect(handler.GetLossDetectionTimeout()).ToNot(BeZero())
Expect(handler.OnLossDetectionTimeout()).To(Succeed())
Expect(handler.SendMode()).To(Equal(SendPTOInitial))
// send a single packet to unblock the server
handler.SentPacket(initialPacket(&Packet{PacketNumber: 2}))
Expect(handler.SendMode()).To(Equal(SendAny))
// Now receive an ACK for a Handshake packet.
// This tells the client that the server completed address validation.
handler.SentPacket(handshakePacket(&Packet{PacketNumber: 1}))
_, err = handler.ReceivedAck(
&wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 1}}},
protocol.EncryptionHandshake,
time.Now(),
)
Expect(err).ToNot(HaveOccurred())
// Make sure that no timer is set at this point.
Expect(handler.GetLossDetectionTimeout()).To(BeZero())
})
It("sends a Handshake packet to unblock the server, if Initial keys were already dropped", func() {
handler.SentPacket(initialPacket(&Packet{PacketNumber: 1}))
_, err := handler.ReceivedAck(
&wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 1}}},
protocol.EncryptionInitial,
time.Now(),
)
Expect(err).ToNot(HaveOccurred())
handler.SentPacket(handshakePacketNonAckEliciting(&Packet{PacketNumber: 1})) // also drops Initial packets
Expect(handler.GetLossDetectionTimeout()).ToNot(BeZero())
Expect(handler.OnLossDetectionTimeout()).To(Succeed())
Expect(handler.SendMode()).To(Equal(SendPTOHandshake))
// Now receive an ACK for this packet, and send another one.
_, err = handler.ReceivedAck(
&wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 1}}},
protocol.EncryptionHandshake,