uquic/internal/ackhandler/sent_packet_handler_test.go
Marten Seemann 7cb84c4e06
Merge pull request #1685 from lucas-clemente/increase-pn-after-vn-and-retry
increase the packet number after version negotiation and retry
2018-12-27 17:00:58 +07:00

978 lines
43 KiB
Go

package ackhandler
import (
"time"
"github.com/golang/mock/gomock"
"github.com/lucas-clemente/quic-go/internal/congestion"
"github.com/lucas-clemente/quic-go/internal/mocks"
"github.com/lucas-clemente/quic-go/internal/protocol"
"github.com/lucas-clemente/quic-go/internal/utils"
"github.com/lucas-clemente/quic-go/internal/wire"
. "github.com/onsi/ginkgo"
. "github.com/onsi/gomega"
)
func retransmittablePacket(p *Packet) *Packet {
if p.EncryptionLevel == protocol.EncryptionUnspecified {
p.EncryptionLevel = protocol.Encryption1RTT
}
if p.Length == 0 {
p.Length = 1
}
if p.SendTime.IsZero() {
p.SendTime = time.Now()
}
p.Frames = []wire.Frame{&wire.PingFrame{}}
return p
}
func nonRetransmittablePacket(p *Packet) *Packet {
p = retransmittablePacket(p)
p.Frames = []wire.Frame{
&wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 1}}},
}
return p
}
func handshakePacket(p *Packet) *Packet {
p = retransmittablePacket(p)
p.EncryptionLevel = protocol.EncryptionInitial
return p
}
var _ = Describe("SentPacketHandler", func() {
var (
handler *sentPacketHandler
streamFrame wire.StreamFrame
)
BeforeEach(func() {
rttStats := &congestion.RTTStats{}
handler = NewSentPacketHandler(42, rttStats, utils.DefaultLogger).(*sentPacketHandler)
handler.SetHandshakeComplete()
streamFrame = wire.StreamFrame{
StreamID: 5,
Data: []byte{0x13, 0x37},
}
})
getPacket := func(pn protocol.PacketNumber) *Packet {
if el, ok := handler.packetHistory.packetMap[pn]; ok {
return &el.Value
}
return nil
}
losePacket := func(pn protocol.PacketNumber) {
p := getPacket(pn)
ExpectWithOffset(1, p).ToNot(BeNil())
handler.queuePacketForRetransmission(p)
if p.includedInBytesInFlight {
p.includedInBytesInFlight = false
handler.bytesInFlight -= p.Length
}
r := handler.DequeuePacketForRetransmission()
ExpectWithOffset(1, r).ToNot(BeNil())
ExpectWithOffset(1, r.PacketNumber).To(Equal(pn))
}
expectInPacketHistory := func(expected []protocol.PacketNumber) {
ExpectWithOffset(1, handler.packetHistory.Len()).To(Equal(len(expected)))
for _, p := range expected {
ExpectWithOffset(1, handler.packetHistory.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(retransmittablePacket(&Packet{PacketNumber: 1}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 2}))
Expect(handler.lastSentPacketNumber).To(Equal(protocol.PacketNumber(2)))
expectInPacketHistory([]protocol.PacketNumber{1, 2})
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(2)))
})
It("accepts packet number 0", func() {
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 0}))
Expect(handler.lastSentPacketNumber).To(BeZero())
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 1}))
Expect(handler.lastSentPacketNumber).To(Equal(protocol.PacketNumber(1)))
expectInPacketHistory([]protocol.PacketNumber{0, 1})
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(2)))
})
It("stores the sent time", func() {
sendTime := time.Now().Add(-time.Minute)
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 1, SendTime: sendTime}))
Expect(handler.lastSentRetransmittablePacketTime).To(Equal(sendTime))
})
It("stores the sent time of handshake packets", func() {
sendTime := time.Now().Add(-time.Minute)
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 1, SendTime: sendTime, EncryptionLevel: protocol.EncryptionInitial}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 2, SendTime: sendTime.Add(time.Hour), EncryptionLevel: protocol.Encryption1RTT}))
Expect(handler.lastSentHandshakePacketTime).To(Equal(sendTime))
})
It("does not store non-retransmittable packets", func() {
handler.SentPacket(nonRetransmittablePacket(&Packet{PacketNumber: 1}))
Expect(handler.packetHistory.Len()).To(BeZero())
Expect(handler.lastSentRetransmittablePacketTime).To(BeZero())
Expect(handler.bytesInFlight).To(BeZero())
})
})
Context("ACK processing", func() {
BeforeEach(func() {
for i := protocol.PacketNumber(0); i < 10; i++ {
handler.SentPacket(retransmittablePacket(&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 validation", func() {
It("accepts ACKs sent in packet 0", func() {
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 0, Largest: 5}}}
err := handler.ReceivedAck(ack, 0, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.largestAcked).To(Equal(protocol.PacketNumber(5)))
})
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, 1337, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.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, 1337, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.largestAcked).To(Equal(protocol.PacketNumber(4)))
})
It("rejects out of order ACKs", func() {
// acks packets 0, 1, 2, 3
ack1 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 0, Largest: 3}}}
ack2 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 0, Largest: 4}}}
err := handler.ReceivedAck(ack1, 1337, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
// this wouldn't happen in practive
// a receiver wouldn't send an ACK for a lower largest acked in a packet sent later
err = handler.ReceivedAck(ack2, 1337-1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.largestAcked).To(Equal(protocol.PacketNumber(3)))
})
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, 1, protocol.Encryption1RTT, time.Now())
Expect(err).To(MatchError("InvalidAckData: Received ACK for an unsent package"))
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(10)))
})
It("ignores repeated ACKs", func() {
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 3}}}
err := handler.ReceivedAck(ack, 1337, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(7)))
err = handler.ReceivedAck(ack, 1337+1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.largestAcked).To(Equal(protocol.PacketNumber(3)))
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(7)))
})
})
Context("acks and nacks the right packets", func() {
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, 1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.largestAcked).To(Equal(protocol.PacketNumber(5)))
expectInPacketHistory([]protocol.PacketNumber{6, 7, 8, 9})
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, 1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(getPacket(0)).To(BeNil())
expectInPacketHistory([]protocol.PacketNumber{1, 2, 3, 4, 5, 6, 7, 8, 9})
})
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, 1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
expectInPacketHistory([]protocol.PacketNumber{0, 4, 5})
})
It("does not ack packets below the LowestAcked", func() {
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 3, Largest: 8}}}
err := handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
expectInPacketHistory([]protocol.PacketNumber{0, 1, 2, 9})
})
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, 1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
expectInPacketHistory([]protocol.PacketNumber{0, 2, 4, 5, 8})
})
It("processes an ACK frame that would be sent after a late arrival of a packet", func() {
ack1 := &wire.AckFrame{ // 3 lost
AckRanges: []wire.AckRange{
{Smallest: 4, Largest: 6},
{Smallest: 1, Largest: 2},
},
}
err := handler.ReceivedAck(ack1, 1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
expectInPacketHistory([]protocol.PacketNumber{0, 3, 7, 8, 9})
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(5)))
ack2 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 6}}} // now ack 3
err = handler.ReceivedAck(ack2, 2, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
expectInPacketHistory([]protocol.PacketNumber{0, 7, 8, 9})
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(4)))
})
It("processes an ACK frame that would be sent after a late arrival of a packet and another packet", func() {
ack1 := &wire.AckFrame{
AckRanges: []wire.AckRange{
{Smallest: 4, Largest: 6},
{Smallest: 0, Largest: 2},
},
}
err := handler.ReceivedAck(ack1, 1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
expectInPacketHistory([]protocol.PacketNumber{3, 7, 8, 9})
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(4)))
ack2 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 7}}}
err = handler.ReceivedAck(ack2, 2, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(2)))
expectInPacketHistory([]protocol.PacketNumber{8, 9})
})
It("processes an ACK that contains old ACK ranges", func() {
ack1 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 6}}}
err := handler.ReceivedAck(ack1, 1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
expectInPacketHistory([]protocol.PacketNumber{0, 7, 8, 9})
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(4)))
ack2 := &wire.AckFrame{
AckRanges: []wire.AckRange{
{Smallest: 8, Largest: 8},
{Smallest: 3, Largest: 3},
{Smallest: 1, Largest: 1},
},
}
err = handler.ReceivedAck(ack2, 2, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
expectInPacketHistory([]protocol.PacketNumber{0, 7, 9})
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(3)))
})
})
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).SendTime = now.Add(-10 * time.Minute)
getPacket(2).SendTime = now.Add(-5 * time.Minute)
getPacket(6).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, 1, protocol.Encryption1RTT, time.Now())
Expect(err).NotTo(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, 2, protocol.Encryption1RTT, time.Now())
Expect(err).NotTo(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, 3, protocol.Encryption1RTT, time.Now())
Expect(err).NotTo(HaveOccurred())
Expect(handler.rttStats.LatestRTT()).To(BeNumerically("~", 1*time.Minute, 1*time.Second))
})
It("uses the DelayTime in the ACK frame", func() {
now := time.Now()
// 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).SendTime = now.Add(-10 * time.Minute)
ack := &wire.AckFrame{
AckRanges: []wire.AckRange{{Smallest: 1, Largest: 1}},
DelayTime: 5 * time.Minute,
}
err := handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())
Expect(err).NotTo(HaveOccurred())
Expect(handler.rttStats.LatestRTT()).To(BeNumerically("~", 5*time.Minute, 1*time.Second))
})
})
Context("determining which ACKs we have received an ACK for", func() {
BeforeEach(func() {
ack1 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 80, Largest: 100}}}
ack2 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 50, Largest: 200}}}
morePackets := []*Packet{
{PacketNumber: 13, Frames: []wire.Frame{ack1, &streamFrame}, Length: 1},
{PacketNumber: 14, Frames: []wire.Frame{ack2, &streamFrame}, Length: 1},
{PacketNumber: 15, Frames: []wire.Frame{&streamFrame}, Length: 1},
}
for _, packet := range morePackets {
handler.SentPacket(packet)
}
})
It("determines which ACK we have received an ACK for", func() {
err := handler.ReceivedAck(&wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 13, Largest: 15}}}, 1, 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() {
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 13, Largest: 13}}}
err := handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.GetLowestPacketNotConfirmedAcked()).To(Equal(protocol.PacketNumber(101)))
ack = &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 15, Largest: 15}}}
err = handler.ReceivedAck(ack, 2, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.GetLowestPacketNotConfirmedAcked()).To(Equal(protocol.PacketNumber(101)))
})
It("doesn't decrease the value", func() {
err := handler.ReceivedAck(&wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 14, Largest: 14}}}, 1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.GetLowestPacketNotConfirmedAcked()).To(Equal(protocol.PacketNumber(201)))
err = handler.ReceivedAck(&wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 13, Largest: 13}}}, 2, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.GetLowestPacketNotConfirmedAcked()).To(Equal(protocol.PacketNumber(201)))
})
})
})
Context("ACK processing, for retransmitted packets", func() {
It("sends a packet as retransmission", func() {
// packet 5 was retransmitted as packet 6
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 5, Length: 10}))
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(10)))
losePacket(5)
Expect(handler.bytesInFlight).To(BeZero())
handler.SentPacketsAsRetransmission([]*Packet{retransmittablePacket(&Packet{PacketNumber: 6, Length: 11})}, 5)
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(11)))
})
It("removes a packet when it is acked", func() {
// packet 5 was retransmitted as packet 6
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 5, Length: 10}))
losePacket(5)
handler.SentPacketsAsRetransmission([]*Packet{retransmittablePacket(&Packet{PacketNumber: 6, Length: 11})}, 5)
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(11)))
// ack 5
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 5, Largest: 5}}}
err := handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
expectInPacketHistory([]protocol.PacketNumber{6})
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(11)))
})
It("handles ACKs that ack the original packet as well as the retransmission", func() {
// packet 5 was retransmitted as packet 7
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 5, Length: 10}))
losePacket(5)
handler.SentPacketsAsRetransmission([]*Packet{retransmittablePacket(&Packet{PacketNumber: 7, Length: 11})}, 5)
// ack 5 and 7
ack := &wire.AckFrame{
AckRanges: []wire.AckRange{
{Smallest: 7, Largest: 7},
{Smallest: 5, Largest: 5},
},
}
err := handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.packetHistory.Len()).To(BeZero())
Expect(handler.bytesInFlight).To(BeZero())
})
})
It("does not dequeue a packet if no ack has been received", func() {
handler.SentPacket(&Packet{PacketNumber: 1})
Expect(handler.DequeuePacketForRetransmission()).To(BeNil())
})
Context("congestion", func() {
var cong *mocks.MockSendAlgorithm
BeforeEach(func() {
cong = mocks.NewMockSendAlgorithm(mockCtrl)
handler.congestion = cong
})
It("should call OnSent", func() {
cong.EXPECT().OnPacketSent(
gomock.Any(),
protocol.ByteCount(42),
protocol.PacketNumber(1),
protocol.ByteCount(42),
true,
)
cong.EXPECT().TimeUntilSend(gomock.Any())
p := &Packet{
PacketNumber: 1,
Length: 42,
Frames: []wire.Frame{&wire.PingFrame{}},
}
handler.SentPacket(p)
})
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)
cong.EXPECT().TimeUntilSend(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(retransmittablePacket(&Packet{PacketNumber: 1}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 2}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 3}))
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 2}}}
err := handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, rcvTime)
Expect(err).NotTo(HaveOccurred())
})
It("doesn't call OnPacketLost and OnRetransmissionTimeout when queuing RTOs", func() {
for i := protocol.PacketNumber(1); i < 3; i++ {
cong.EXPECT().OnPacketSent(gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any())
cong.EXPECT().TimeUntilSend(gomock.Any())
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: i}))
}
handler.OnAlarm() // TLP
handler.OnAlarm() // TLP
handler.OnAlarm() // RTO
})
It("declares all lower packets lost and call OnRetransmissionTimeout when verifying an RTO", func() {
cong.EXPECT().OnPacketSent(gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any()).Times(5)
cong.EXPECT().TimeUntilSend(gomock.Any()).Times(5)
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 2, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 3, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 4, SendTime: time.Now().Add(-time.Hour)}))
handler.OnAlarm() // TLP
handler.OnAlarm() // TLP
handler.OnAlarm() // RTO
// send one probe packet and receive an ACK for it
rcvTime := time.Now()
gomock.InOrder(
cong.EXPECT().MaybeExitSlowStart(),
cong.EXPECT().OnRetransmissionTimeout(true),
cong.EXPECT().OnPacketAcked(protocol.PacketNumber(5), protocol.ByteCount(1), protocol.ByteCount(5), rcvTime),
cong.EXPECT().OnPacketLost(protocol.PacketNumber(1), protocol.ByteCount(1), protocol.ByteCount(5)),
cong.EXPECT().OnPacketLost(protocol.PacketNumber(2), protocol.ByteCount(1), protocol.ByteCount(5)),
cong.EXPECT().OnPacketLost(protocol.PacketNumber(3), protocol.ByteCount(1), protocol.ByteCount(5)),
cong.EXPECT().OnPacketLost(protocol.PacketNumber(4), protocol.ByteCount(1), protocol.ByteCount(5)),
)
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 5}))
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 5, Largest: 5}}}
err := handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, rcvTime)
Expect(err).ToNot(HaveOccurred())
})
It("doesn't call OnRetransmissionTimeout when a spurious RTO occurs", func() {
cong.EXPECT().OnPacketSent(gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any()).Times(3)
cong.EXPECT().TimeUntilSend(gomock.Any()).Times(3)
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 2, SendTime: time.Now()}))
handler.OnAlarm() // TLP
handler.OnAlarm() // TLP
handler.OnAlarm() // RTO
// send one probe packet
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 3}))
// receive an ACK for a packet send *before* the probe packet
// don't EXPECT any call to OnRetransmissionTimeout
gomock.InOrder(
cong.EXPECT().MaybeExitSlowStart(),
cong.EXPECT().OnPacketAcked(protocol.PacketNumber(2), protocol.ByteCount(1), protocol.ByteCount(3), gomock.Any()),
cong.EXPECT().OnPacketLost(protocol.PacketNumber(1), protocol.ByteCount(1), protocol.ByteCount(3)),
)
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 2, Largest: 2}}}
err := handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())
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)
cong.EXPECT().TimeUntilSend(gomock.Any()).Times(2)
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 2}))
// lose packet 1
gomock.InOrder(
cong.EXPECT().MaybeExitSlowStart(),
cong.EXPECT().OnPacketAcked(protocol.PacketNumber(2), protocol.ByteCount(1), protocol.ByteCount(2), gomock.Any()),
cong.EXPECT().OnPacketLost(protocol.PacketNumber(1), protocol.ByteCount(1), protocol.ByteCount(2)),
)
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 2, Largest: 2}}}
err := handler.ReceivedAck(ack, 1, 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, 2, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
})
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)
cong.EXPECT().TimeUntilSend(gomock.Any()).Times(4)
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 2, SendTime: time.Now().Add(-30 * time.Minute)}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 3, SendTime: time.Now().Add(-30 * time.Minute)}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 4, SendTime: time.Now()}))
// receive the first ACK
gomock.InOrder(
cong.EXPECT().MaybeExitSlowStart(),
cong.EXPECT().OnPacketAcked(protocol.PacketNumber(2), protocol.ByteCount(1), protocol.ByteCount(4), gomock.Any()),
cong.EXPECT().OnPacketLost(protocol.PacketNumber(1), protocol.ByteCount(1), protocol.ByteCount(4)),
)
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 2, Largest: 2}}}
err := handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now().Add(-30*time.Minute))
Expect(err).ToNot(HaveOccurred())
// receive the second ACK
gomock.InOrder(
cong.EXPECT().MaybeExitSlowStart(),
cong.EXPECT().OnPacketAcked(protocol.PacketNumber(4), protocol.ByteCount(1), protocol.ByteCount(2), gomock.Any()),
cong.EXPECT().OnPacketLost(protocol.PacketNumber(3), protocol.ByteCount(1), protocol.ByteCount(2)),
)
ack = &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 4, Largest: 4}}}
err = handler.ReceivedAck(ack, 2, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
})
It("only allows sending of ACKs when congestion limited", func() {
handler.bytesInFlight = 100
cong.EXPECT().GetCongestionWindow().Return(protocol.ByteCount(200))
Expect(handler.SendMode()).To(Equal(SendAny))
cong.EXPECT().GetCongestionWindow().Return(protocol.ByteCount(75))
Expect(handler.SendMode()).To(Equal(SendAck))
})
It("only allows sending of ACKs when we're keeping track of MaxOutstandingSentPackets packets", func() {
cong.EXPECT().GetCongestionWindow().Return(protocol.MaxByteCount).AnyTimes()
cong.EXPECT().TimeUntilSend(gomock.Any()).AnyTimes()
cong.EXPECT().OnPacketSent(gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any()).AnyTimes()
for i := protocol.PacketNumber(1); i < protocol.MaxOutstandingSentPackets; i++ {
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: i}))
Expect(handler.SendMode()).To(Equal(SendAny))
}
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: protocol.MaxOutstandingSentPackets}))
Expect(handler.SendMode()).To(Equal(SendAck))
})
It("doesn't allow retransmission if congestion limited", func() {
handler.bytesInFlight = 100
handler.retransmissionQueue = []*Packet{{PacketNumber: 3}}
cong.EXPECT().GetCongestionWindow().Return(protocol.ByteCount(50))
Expect(handler.SendMode()).To(Equal(SendAck))
})
It("allows sending retransmissions", func() {
cong.EXPECT().GetCongestionWindow().Return(protocol.MaxByteCount)
handler.retransmissionQueue = []*Packet{{PacketNumber: 3}}
Expect(handler.SendMode()).To(Equal(SendRetransmission))
})
It("allow retransmissions, if we're keeping track of between MaxOutstandingSentPackets and MaxTrackedSentPackets packets", func() {
cong.EXPECT().GetCongestionWindow().Return(protocol.MaxByteCount)
Expect(protocol.MaxOutstandingSentPackets).To(BeNumerically("<", protocol.MaxTrackedSentPackets))
handler.retransmissionQueue = make([]*Packet, protocol.MaxOutstandingSentPackets+10)
Expect(handler.SendMode()).To(Equal(SendRetransmission))
handler.retransmissionQueue = make([]*Packet, protocol.MaxTrackedSentPackets)
Expect(handler.SendMode()).To(Equal(SendNone))
})
It("allows RTOs, even when congestion limited", func() {
// note that we don't EXPECT a call to GetCongestionWindow
// that means retransmissions are sent without considering the congestion window
handler.numRTOs = 1
handler.retransmissionQueue = []*Packet{{PacketNumber: 3}}
Expect(handler.SendMode()).To(Equal(SendRTO))
})
It("gets the pacing delay", func() {
sendTime := time.Now().Add(-time.Minute)
handler.bytesInFlight = 100
cong.EXPECT().OnPacketSent(gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any(), gomock.Any())
cong.EXPECT().TimeUntilSend(protocol.ByteCount(100)).Return(time.Hour)
handler.SentPacket(&Packet{PacketNumber: 1, SendTime: sendTime})
Expect(handler.TimeUntilSend()).To(Equal(sendTime.Add(time.Hour)))
})
It("allows sending of all RTO probe packets", func() {
handler.numRTOs = 5
Expect(handler.ShouldSendNumPackets()).To(Equal(5))
})
It("allows sending of one packet, if it should be sent immediately", func() {
cong.EXPECT().TimeUntilSend(gomock.Any()).Return(time.Duration(0))
Expect(handler.ShouldSendNumPackets()).To(Equal(1))
})
It("allows sending of multiple packets, if the pacing delay is smaller than the minimum", func() {
pacingDelay := protocol.MinPacingDelay / 10
cong.EXPECT().TimeUntilSend(gomock.Any()).Return(pacingDelay)
Expect(handler.ShouldSendNumPackets()).To(Equal(10))
})
It("allows sending of multiple packets, if the pacing delay is smaller than the minimum, and not a fraction", func() {
pacingDelay := protocol.MinPacingDelay * 2 / 5
cong.EXPECT().TimeUntilSend(gomock.Any()).Return(pacingDelay)
Expect(handler.ShouldSendNumPackets()).To(Equal(3))
})
})
It("doesn't set an alarm if there are no outstanding packets", func() {
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 10}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 11}))
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 10, Largest: 11}}}
err := handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.GetAlarmTimeout()).To(BeZero())
})
It("does nothing on OnAlarm if there are no outstanding packets", func() {
Expect(handler.OnAlarm()).To(Succeed())
Expect(handler.SendMode()).To(Equal(SendAny))
})
Context("TLPs", func() {
It("uses the RTT from RTT stats", func() {
rtt := 2 * time.Second
updateRTT(rtt)
Expect(handler.computeTLPTimeout()).To(Equal(rtt * 3 / 2))
})
It("uses the minTLPTimeout for short RTTs", func() {
rtt := 2 * time.Microsecond
updateRTT(rtt)
Expect(handler.computeTLPTimeout()).To(Equal(minTPLTimeout))
})
It("sets the TLP send mode until one retransmittable packet is sent", func() {
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
handler.OnAlarm()
Expect(handler.SendMode()).To(Equal(SendTLP))
// Send a non-retransmittable packet.
// It doesn't count as a probe packet.
handler.SentPacket(nonRetransmittablePacket(&Packet{PacketNumber: 2}))
Expect(handler.SendMode()).To(Equal(SendTLP))
// Send a retransmittable packet.
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 3}))
Expect(handler.SendMode()).ToNot(Equal(SendTLP))
})
It("sends two TLPs, then RTOs", func() {
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 2, SendTime: time.Now().Add(-time.Hour)}))
// first TLP
handler.OnAlarm()
Expect(handler.SendMode()).To(Equal(SendTLP))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 3}))
// second TLP
handler.OnAlarm()
Expect(handler.SendMode()).To(Equal(SendTLP))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 4}))
// fire alarm a third time
handler.OnAlarm()
Expect(handler.SendMode()).To(Equal(SendRTO))
})
})
Context("RTOs", func() {
It("uses default RTO", func() {
Expect(handler.computeRTOTimeout()).To(Equal(defaultRTOTimeout))
})
It("uses RTO from rttStats", func() {
rtt := time.Second
handler.rttStats.UpdateRTT(rtt, 0, time.Now())
Expect(handler.rttStats.SmoothedRTT()).To(Equal(rtt))
Expect(handler.rttStats.MeanDeviation()).To(Equal(rtt / 2))
expected := rtt + rtt/2*4
Expect(handler.computeRTOTimeout()).To(Equal(expected))
})
It("limits RTO min", func() {
rtt := 3 * time.Millisecond
updateRTT(rtt)
Expect(handler.computeRTOTimeout()).To(Equal(minRTOTimeout))
})
It("limits RTO max", func() {
updateRTT(time.Hour)
Expect(handler.computeRTOTimeout()).To(Equal(maxRTOTimeout))
})
It("implements exponential backoff", func() {
handler.rtoCount = 0
Expect(handler.computeRTOTimeout()).To(Equal(defaultRTOTimeout))
handler.rtoCount = 1
Expect(handler.computeRTOTimeout()).To(Equal(2 * defaultRTOTimeout))
handler.rtoCount = 2
Expect(handler.computeRTOTimeout()).To(Equal(4 * defaultRTOTimeout))
})
It("gets two probe packets if RTO expires", func() {
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 1}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 2}))
updateRTT(time.Hour)
Expect(handler.lossTime.IsZero()).To(BeTrue())
Expect(time.Until(handler.GetAlarmTimeout())).To(BeNumerically("~", handler.computeRTOTimeout(), time.Minute))
handler.OnAlarm() // TLP
handler.OnAlarm() // TLP
handler.OnAlarm() // RTO
p, err := handler.DequeueProbePacket()
Expect(err).ToNot(HaveOccurred())
Expect(p).ToNot(BeNil())
Expect(p.PacketNumber).To(Equal(protocol.PacketNumber(1)))
p, err = handler.DequeueProbePacket()
Expect(err).ToNot(HaveOccurred())
Expect(p).ToNot(BeNil())
Expect(p.PacketNumber).To(Equal(protocol.PacketNumber(2)))
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(2)))
Expect(handler.rtoCount).To(BeEquivalentTo(1))
})
It("doesn't delete packets transmitted as RTO from the history", func() {
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 2, SendTime: time.Now().Add(-time.Hour)}))
handler.rttStats.UpdateRTT(time.Second, 0, time.Now())
handler.OnAlarm() // TLP
handler.OnAlarm() // TLP
handler.OnAlarm() // RTO
_, err := handler.DequeueProbePacket()
Expect(err).ToNot(HaveOccurred())
_, err = handler.DequeueProbePacket()
Expect(err).ToNot(HaveOccurred())
expectInPacketHistory([]protocol.PacketNumber{1, 2})
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(2)))
// Send a probe packet and receive an ACK for it.
// This verifies the RTO.
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 3}))
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 3, Largest: 3}}}
err = handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.packetHistory.Len()).To(BeZero())
Expect(handler.bytesInFlight).To(BeZero())
Expect(handler.retransmissionQueue).To(BeEmpty()) // 1 and 2 were already sent as probe packets
})
It("allows sending of two probe packets", func() {
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
handler.OnAlarm() // TLP
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 2})) // send the first TLP
handler.OnAlarm() // TLP
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 3})) // send the second TLP
handler.OnAlarm() // RTO
Expect(handler.SendMode()).To(Equal(SendRTO))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 4}))
Expect(handler.SendMode()).To(Equal(SendRTO))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 5}))
Expect(handler.SendMode()).ToNot(Equal(SendRTO))
})
It("gets packets sent before the probe packet for retransmission", func() {
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 2, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 3, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 4, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 5, SendTime: time.Now().Add(-time.Hour)}))
handler.OnAlarm() // TLP
handler.OnAlarm() // TLP
handler.OnAlarm() // RTO
_, err := handler.DequeueProbePacket()
Expect(err).ToNot(HaveOccurred())
_, err = handler.DequeueProbePacket()
Expect(err).ToNot(HaveOccurred())
expectInPacketHistory([]protocol.PacketNumber{1, 2, 3, 4, 5})
// Send a probe packet and receive an ACK for it.
// This verifies the RTO.
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 6}))
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 6, Largest: 6}}}
err = handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
Expect(handler.packetHistory.Len()).To(BeZero())
Expect(handler.bytesInFlight).To(BeZero())
Expect(handler.retransmissionQueue).To(HaveLen(3)) // packets 3, 4, 5
})
It("handles ACKs for the original packet", func() {
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 5, SendTime: time.Now().Add(-time.Hour)}))
handler.rttStats.UpdateRTT(time.Second, 0, time.Now())
handler.OnAlarm() // TLP
handler.OnAlarm() // TLP
handler.OnAlarm() // RTO
handler.SentPacketsAsRetransmission([]*Packet{retransmittablePacket(&Packet{PacketNumber: 6})}, 5)
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 5, Largest: 5}}}
err := handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())
Expect(err).ToNot(HaveOccurred())
err = handler.OnAlarm()
Expect(err).ToNot(HaveOccurred())
})
It("handles ACKs for the original packet", func() {
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 5, SendTime: time.Now().Add(-time.Hour)}))
handler.rttStats.UpdateRTT(time.Second, 0, time.Now())
err := handler.OnAlarm()
Expect(err).ToNot(HaveOccurred())
err = handler.OnAlarm()
Expect(err).ToNot(HaveOccurred())
})
})
Context("Delay-based loss detection", func() {
It("immediately detects old packets as lost when receiving an ACK", func() {
now := time.Now()
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 1, SendTime: now.Add(-time.Hour)}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 2, SendTime: now.Add(-time.Second)}))
Expect(handler.lossTime.IsZero()).To(BeTrue())
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 2, Largest: 2}}}
err := handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, now)
Expect(err).NotTo(HaveOccurred())
Expect(handler.DequeuePacketForRetransmission()).ToNot(BeNil())
Expect(handler.DequeuePacketForRetransmission()).To(BeNil())
// no need to set an alarm, since packet 1 was already declared lost
Expect(handler.lossTime.IsZero()).To(BeTrue())
Expect(handler.bytesInFlight).To(BeZero())
})
It("sets the early retransmit alarm", func() {
now := time.Now()
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 1, SendTime: now.Add(-2 * time.Second)}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 2, SendTime: now.Add(-2 * time.Second)}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 3, SendTime: now.Add(-time.Second)}))
Expect(handler.lossTime.IsZero()).To(BeTrue())
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 2, Largest: 2}}}
err := handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, now.Add(-time.Second))
Expect(err).NotTo(HaveOccurred())
Expect(handler.rttStats.SmoothedRTT()).To(Equal(time.Second))
// Packet 1 should be considered lost (1+1/8) RTTs after it was sent.
Expect(handler.lossTime.IsZero()).To(BeFalse())
Expect(handler.lossTime.Sub(getPacket(1).SendTime)).To(Equal(time.Second * 9 / 8))
err = handler.OnAlarm()
Expect(err).ToNot(HaveOccurred())
Expect(handler.DequeuePacketForRetransmission()).NotTo(BeNil())
// make sure this is not an RTO: only packet 1 is retransmissted
Expect(handler.DequeuePacketForRetransmission()).To(BeNil())
})
})
Context("handshake packets", func() {
BeforeEach(func() {
handler.handshakeComplete = false
})
It("detects the handshake timeout", func() {
now := time.Now()
sendTime := now.Add(-time.Minute)
lastHandshakePacketSendTime := now.Add(-30 * time.Second)
// send handshake packets: 1, 3
// send a forward-secure packet: 2
handler.SentPacket(handshakePacket(&Packet{PacketNumber: 1, SendTime: sendTime}))
handler.SentPacket(retransmittablePacket(&Packet{PacketNumber: 2, SendTime: sendTime}))
handler.SentPacket(handshakePacket(&Packet{PacketNumber: 3, SendTime: sendTime}))
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 1}}}
err := handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, now)
// RTT is now 1 minute
Expect(handler.rttStats.SmoothedRTT()).To(Equal(time.Minute))
Expect(err).NotTo(HaveOccurred())
Expect(handler.lossTime.IsZero()).To(BeTrue())
Expect(handler.GetAlarmTimeout().Sub(sendTime)).To(Equal(2 * time.Minute))
err = handler.OnAlarm()
Expect(err).ToNot(HaveOccurred())
p := handler.DequeuePacketForRetransmission()
Expect(p).ToNot(BeNil())
Expect(p.PacketNumber).To(Equal(protocol.PacketNumber(3)))
Expect(handler.handshakeCount).To(BeEquivalentTo(1))
handler.SentPacket(handshakePacket(&Packet{PacketNumber: 4, SendTime: lastHandshakePacketSendTime}))
// make sure the exponential backoff is used
Expect(handler.GetAlarmTimeout().Sub(lastHandshakePacketSendTime)).To(Equal(4 * time.Minute))
})
// TODO(#1534): also check the encryption level for IETF QUIC
PIt("rejects an ACK that acks packets with a higher encryption level", func() {
handler.SentPacket(&Packet{
PacketNumber: 13,
EncryptionLevel: protocol.Encryption1RTT,
Frames: []wire.Frame{&streamFrame},
Length: 1,
})
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 13, Largest: 13}}}
err := handler.ReceivedAck(ack, 1, protocol.EncryptionHandshake, time.Now())
Expect(err).To(MatchError("Received ACK with encryption level encrypted (not forward-secure) that acks a packet 13 (encryption level forward-secure)"))
})
It("deletes non handshake packets when the handshake completes", func() {
for i := protocol.PacketNumber(1); i <= 6; i++ {
p := retransmittablePacket(&Packet{PacketNumber: i})
p.EncryptionLevel = protocol.EncryptionHandshake
handler.SentPacket(p)
}
handler.queuePacketForRetransmission(getPacket(1))
handler.queuePacketForRetransmission(getPacket(3))
handler.SetHandshakeComplete()
Expect(handler.packetHistory.Len()).To(BeZero())
packet := handler.DequeuePacketForRetransmission()
Expect(packet).To(BeNil())
})
})
Context("peeking and popping packet number", func() {
It("peeks and pops the initial packet number", func() {
pn, _ := handler.PeekPacketNumber()
Expect(pn).To(Equal(protocol.PacketNumber(42)))
Expect(handler.PopPacketNumber()).To(Equal(protocol.PacketNumber(42)))
})
It("peeks and pops beyond the initial packet number", func() {
Expect(handler.PopPacketNumber()).To(Equal(protocol.PacketNumber(42)))
Expect(handler.PopPacketNumber()).To(BeNumerically(">", 42))
})
})
})