uquic/internal/ackhandler/sent_packet_handler_test.go
Marten Seemann 66abcdfc5c move calculation of the PTO to the rttStats
The PTO value is needed at various places in the protocol. Calculating
it on the rttStats struct will allow us to pass around this struct.
2019-06-29 14:57:24 +07:00

925 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 ackElicitingPacket(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 nonAckElicitingPacket(p *Packet) *Packet {
p = ackElicitingPacket(p)
p.Frames = nil
p.Ack = &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 1}}}
return p
}
func cryptoPacket(p *Packet) *Packet {
p = ackElicitingPacket(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, nil, utils.DefaultLogger).(*sentPacketHandler)
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
}
losePacket := func(pn protocol.PacketNumber, encLevel protocol.EncryptionLevel) {
p := getPacket(pn, encLevel)
ExpectWithOffset(1, p).ToNot(BeNil())
handler.queuePacketForRetransmission(p, handler.getPacketNumberSpace(encLevel))
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, encLevel protocol.EncryptionLevel) {
pnSpace := handler.getPacketNumberSpace(encLevel)
ExpectWithOffset(1, pnSpace.history.Len()).To(Equal(len(expected)))
for _, p := range expected {
ExpectWithOffset(1, 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("accepts packet number 0", func() {
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 0, EncryptionLevel: protocol.Encryption1RTT}))
Expect(handler.oneRTTPackets.largestSent).To(BeZero())
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, EncryptionLevel: protocol.Encryption1RTT}))
Expect(handler.oneRTTPackets.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.lastSentAckElicitingPacketTime).To(Equal(sendTime))
})
It("stores the sent time of crypto 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.lastSentCryptoPacketTime).To(Equal(sendTime))
})
It("does not store non-ack-eliciting packets", func() {
handler.SentPacket(nonAckElicitingPacket(&Packet{PacketNumber: 1, EncryptionLevel: protocol.Encryption1RTT}))
Expect(handler.oneRTTPackets.history.Len()).To(BeZero())
Expect(handler.lastSentAckElicitingPacketTime).To(BeZero())
Expect(handler.bytesInFlight).To(BeZero())
})
})
Context("ACK processing", func() {
BeforeEach(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 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.oneRTTPackets.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}}}
Expect(handler.ReceivedAck(ack1, 1337, protocol.Encryption1RTT, time.Now())).To(Succeed())
Expect(handler.oneRTTPackets.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
Expect(handler.ReceivedAck(ack2, 1337, protocol.Encryption1RTT, time.Now())).To(Succeed())
Expect(handler.oneRTTPackets.largestAcked).To(Equal(protocol.PacketNumber(4)))
})
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("PROTOCOL_VIOLATION: 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: 1, Largest: 3}}}
Expect(handler.ReceivedAck(ack, 1337, protocol.Encryption1RTT, time.Now())).To(Succeed())
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(7)))
Expect(handler.ReceivedAck(ack, 1337+1, protocol.Encryption1RTT, time.Now())).To(Succeed())
Expect(handler.oneRTTPackets.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}}}
Expect(handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())).To(Succeed())
Expect(handler.oneRTTPackets.largestAcked).To(Equal(protocol.PacketNumber(5)))
expectInPacketHistory([]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}}}
Expect(handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())).To(Succeed())
Expect(getPacket(0, protocol.Encryption1RTT)).To(BeNil())
expectInPacketHistory([]protocol.PacketNumber{1, 2, 3, 4, 5, 6, 7, 8, 9}, protocol.Encryption1RTT)
})
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},
},
}
Expect(handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())).To(Succeed())
expectInPacketHistory([]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}}}
Expect(handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())).To(Succeed())
expectInPacketHistory([]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},
},
}
Expect(handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())).To(Succeed())
expectInPacketHistory([]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{ // 3 lost
AckRanges: []wire.AckRange{
{Smallest: 4, Largest: 6},
{Smallest: 1, Largest: 2},
},
}
Expect(handler.ReceivedAck(ack1, 1, protocol.Encryption1RTT, time.Now())).To(Succeed())
expectInPacketHistory([]protocol.PacketNumber{0, 3, 7, 8, 9}, protocol.Encryption1RTT)
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(5)))
ack2 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 6}}} // now ack 3
Expect(handler.ReceivedAck(ack2, 2, protocol.Encryption1RTT, time.Now())).To(Succeed())
expectInPacketHistory([]protocol.PacketNumber{0, 7, 8, 9}, protocol.Encryption1RTT)
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},
},
}
Expect(handler.ReceivedAck(ack1, 1, protocol.Encryption1RTT, time.Now())).To(Succeed())
expectInPacketHistory([]protocol.PacketNumber{3, 7, 8, 9}, protocol.Encryption1RTT)
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(4)))
ack2 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 7}}}
Expect(handler.ReceivedAck(ack2, 2, protocol.Encryption1RTT, time.Now())).To(Succeed())
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(2)))
expectInPacketHistory([]protocol.PacketNumber{8, 9}, protocol.Encryption1RTT)
})
It("processes an ACK that contains old ACK ranges", func() {
ack1 := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 6}}}
Expect(handler.ReceivedAck(ack1, 1, protocol.Encryption1RTT, time.Now())).To(Succeed())
expectInPacketHistory([]protocol.PacketNumber{0, 7, 8, 9}, protocol.Encryption1RTT)
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},
},
}
Expect(handler.ReceivedAck(ack2, 2, protocol.Encryption1RTT, time.Now())).To(Succeed())
expectInPacketHistory([]protocol.PacketNumber{0, 7, 9}, protocol.Encryption1RTT)
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, 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, 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("ignores the DelayTime for Initial and Handshake packets", func() {
handler.SentPacket(cryptoPacket(&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,
}
Expect(handler.ReceivedAck(ack, 1, protocol.EncryptionInitial, time.Now())).To(Succeed())
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,
}
Expect(handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())).To(Succeed())
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,
}
Expect(handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())).To(Succeed())
Expect(handler.rttStats.LatestRTT()).To(BeNumerically("~", 9*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, Ack: ack1, Frames: []wire.Frame{&streamFrame}, Length: 1, EncryptionLevel: protocol.Encryption1RTT},
{PacketNumber: 14, Ack: ack2, Frames: []wire.Frame{&streamFrame}, Length: 1, EncryptionLevel: protocol.Encryption1RTT},
{PacketNumber: 15, Frames: []wire.Frame{&streamFrame}, 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}}}
Expect(handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())).To(Succeed())
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}}}
Expect(handler.ReceivedAck(ack1, 1, protocol.Encryption1RTT, time.Now())).To(Succeed())
Expect(handler.GetLowestPacketNotConfirmedAcked()).To(Equal(protocol.PacketNumber(101)))
Expect(handler.ReceivedAck(ack2, 2, protocol.Encryption1RTT, time.Now())).To(Succeed())
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}}}
Expect(handler.ReceivedAck(ack1, 1, protocol.Encryption1RTT, time.Now())).To(Succeed())
Expect(handler.GetLowestPacketNotConfirmedAcked()).To(Equal(protocol.PacketNumber(201)))
Expect(handler.ReceivedAck(ack2, 2, protocol.Encryption1RTT, time.Now())).To(Succeed())
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(ackElicitingPacket(&Packet{PacketNumber: 5, Length: 10, EncryptionLevel: protocol.Encryption1RTT}))
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(10)))
losePacket(5, protocol.Encryption1RTT)
Expect(handler.bytesInFlight).To(BeZero())
handler.SentPacketsAsRetransmission([]*Packet{ackElicitingPacket(&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(ackElicitingPacket(&Packet{PacketNumber: 5, Length: 10}))
losePacket(5, protocol.Encryption1RTT)
handler.SentPacketsAsRetransmission([]*Packet{ackElicitingPacket(&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}, protocol.Encryption1RTT)
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(ackElicitingPacket(&Packet{PacketNumber: 5, Length: 10}))
losePacket(5, protocol.Encryption1RTT)
handler.SentPacketsAsRetransmission([]*Packet{ackElicitingPacket(&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.oneRTTPackets.history.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, EncryptionLevel: protocol.Encryption1RTT, SendTime: time.Now().Add(-time.Hour)})
Expect(handler.DequeuePacketForRetransmission()).To(BeNil())
})
Context("congestion", func() {
var cong *mocks.MockSendAlgorithmWithDebugInfos
BeforeEach(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,
)
cong.EXPECT().TimeUntilSend(gomock.Any())
handler.SentPacket(&Packet{
PacketNumber: 1,
Length: 42,
Frames: []wire.Frame{&wire.PingFrame{}},
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)
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(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, 1, protocol.Encryption1RTT, rcvTime)
Expect(err).NotTo(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(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().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(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().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("passes the bytes in flight to CanSend", func() {
handler.bytesInFlight = 42
cong.EXPECT().CanSend(protocol.ByteCount(42))
handler.SendMode()
})
It("allows sending of ACKs when congestion limited", func() {
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() {
cong.EXPECT().CanSend(gomock.Any()).Return(true).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(ackElicitingPacket(&Packet{PacketNumber: i}))
Expect(handler.SendMode()).To(Equal(SendAny))
}
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: protocol.MaxOutstandingSentPackets}))
Expect(handler.SendMode()).To(Equal(SendAck))
})
It("doesn't allow retransmissions if congestion limited", func() {
handler.retransmissionQueue = []*Packet{{PacketNumber: 3}}
cong.EXPECT().CanSend(gomock.Any()).Return(false)
Expect(handler.SendMode()).To(Equal(SendAck))
})
It("allows sending retransmissions", func() {
cong.EXPECT().CanSend(gomock.Any()).Return(true)
handler.retransmissionQueue = []*Packet{{PacketNumber: 3}}
Expect(handler.SendMode()).To(Equal(SendRetransmission))
})
It("allows retransmissions, if we're keeping track of between MaxOutstandingSentPackets and MaxTrackedSentPackets packets", func() {
cong.EXPECT().CanSend(gomock.Any()).Return(true)
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.numProbesToSend = 1
handler.retransmissionQueue = []*Packet{{PacketNumber: 3}}
Expect(handler.SendMode()).To(Equal(SendPTO))
})
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, EncryptionLevel: protocol.Encryption1RTT})
Expect(handler.TimeUntilSend()).To(Equal(sendTime.Add(time.Hour)))
})
It("allows sending of all RTO probe packets", func() {
handler.numProbesToSend = 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(ackElicitingPacket(&Packet{PacketNumber: 10}))
handler.SentPacket(ackElicitingPacket(&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("probe packets", func() {
It("implements exponential backoff", func() {
sendTime := time.Now().Add(-time.Hour)
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, SendTime: sendTime}))
timeout := handler.GetAlarmTimeout().Sub(sendTime)
Expect(handler.GetAlarmTimeout().Sub(sendTime)).To(Equal(timeout))
handler.ptoCount = 1
handler.updateLossDetectionAlarm()
Expect(handler.GetAlarmTimeout().Sub(sendTime)).To(Equal(2 * timeout))
handler.ptoCount = 2
handler.updateLossDetectionAlarm()
Expect(handler.GetAlarmTimeout().Sub(sendTime)).To(Equal(4 * timeout))
})
It("sets the TPO send mode until two packets is sent", func() {
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
handler.OnAlarm()
Expect(handler.SendMode()).To(Equal(SendPTO))
Expect(handler.ShouldSendNumPackets()).To(Equal(2))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 2}))
Expect(handler.SendMode()).To(Equal(SendPTO))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 3}))
Expect(handler.SendMode()).ToNot(Equal(SendPTO))
})
It("only counts ack-eliciting packets as probe packets", func() {
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
handler.OnAlarm()
Expect(handler.SendMode()).To(Equal(SendPTO))
Expect(handler.ShouldSendNumPackets()).To(Equal(2))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 2}))
Expect(handler.SendMode()).To(Equal(SendPTO))
for p := protocol.PacketNumber(3); p < 30; p++ {
handler.SentPacket(nonAckElicitingPacket(&Packet{PacketNumber: p}))
Expect(handler.SendMode()).To(Equal(SendPTO))
}
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 30}))
Expect(handler.SendMode()).ToNot(Equal(SendPTO))
})
It("gets two probe packets if RTO expires", func() {
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 2}))
updateRTT(time.Hour)
Expect(handler.lossTime.IsZero()).To(BeTrue())
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.ptoCount).To(BeEquivalentTo(3))
})
It("doesn't delete packets transmitted as PTO from the history", func() {
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(ackElicitingPacket(&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}, protocol.Encryption1RTT)
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(2)))
// Send a probe packet and receive an ACK for it.
// This verifies the RTO.
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 3}))
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 3, Largest: 3}}}
Expect(handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())).To(Succeed())
Expect(err).ToNot(HaveOccurred())
Expect(handler.oneRTTPackets.history.Len()).To(BeZero())
Expect(handler.bytesInFlight).To(BeZero())
Expect(handler.retransmissionQueue).To(BeEmpty()) // 1 and 2 were already sent as probe packets
})
It("resets the send mode when it receives an acknowledgement after queueing probe packets", func() {
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
handler.rttStats.UpdateRTT(time.Second, 0, time.Now())
handler.OnAlarm()
Expect(handler.SendMode()).To(Equal(SendPTO))
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 1}}}
Expect(handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, time.Now())).To(Succeed())
Expect(handler.SendMode()).To(Equal(SendAny))
})
It("gets packets sent before the probe packet for retransmission", func() {
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 1, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 2, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 3, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 4, SendTime: time.Now().Add(-time.Hour)}))
handler.SentPacket(ackElicitingPacket(&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}, protocol.Encryption1RTT)
// Send a probe packet and receive an ACK for it.
// This verifies the RTO.
handler.SentPacket(ackElicitingPacket(&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.oneRTTPackets.history.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(ackElicitingPacket(&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{ackElicitingPacket(&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(ackElicitingPacket(&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(ackElicitingPacket(&Packet{PacketNumber: 1, SendTime: now.Add(-time.Hour)}))
handler.SentPacket(ackElicitingPacket(&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(ackElicitingPacket(&Packet{PacketNumber: 1, SendTime: now.Add(-2 * time.Second), EncryptionLevel: protocol.Encryption1RTT}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 2, SendTime: now.Add(-2 * time.Second), EncryptionLevel: protocol.Encryption1RTT}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 3, SendTime: now.Add(-time.Second), EncryptionLevel: protocol.Encryption1RTT}))
Expect(handler.lossTime.IsZero()).To(BeTrue())
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 2, Largest: 2}}}
Expect(handler.ReceivedAck(ack, 1, protocol.Encryption1RTT, now.Add(-time.Second))).To(Succeed())
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, protocol.Encryption1RTT).SendTime)).To(Equal(time.Second * 9 / 8))
Expect(handler.OnAlarm()).To(Succeed())
Expect(handler.DequeuePacketForRetransmission()).NotTo(BeNil())
// make sure this is not an RTO: only packet 1 is retransmissted
Expect(handler.DequeuePacketForRetransmission()).To(BeNil())
})
})
Context("crypto packets", func() {
It("detects the crypto timeout", func() {
now := time.Now()
sendTime := now.Add(-time.Minute)
lastCryptoPacketSendTime := now.Add(-30 * time.Second)
// send Initial packets: 1, 3
// send 1-RTT packet: 100
handler.SentPacket(cryptoPacket(&Packet{PacketNumber: 1, SendTime: sendTime, EncryptionLevel: protocol.EncryptionInitial}))
handler.SentPacket(cryptoPacket(&Packet{PacketNumber: 3, SendTime: sendTime, EncryptionLevel: protocol.EncryptionInitial}))
handler.SentPacket(ackElicitingPacket(&Packet{PacketNumber: 100, SendTime: sendTime, EncryptionLevel: protocol.Encryption1RTT}))
ack := &wire.AckFrame{AckRanges: []wire.AckRange{{Smallest: 1, Largest: 1}}}
Expect(handler.ReceivedAck(ack, 1, protocol.EncryptionInitial, now)).To(Succeed())
// RTT is now 1 minute
Expect(handler.rttStats.SmoothedRTT()).To(Equal(time.Minute))
Expect(handler.lossTime.IsZero()).To(BeTrue())
Expect(handler.GetAlarmTimeout().Sub(sendTime)).To(Equal(2 * time.Minute))
Expect(handler.OnAlarm()).To(Succeed())
p := handler.DequeuePacketForRetransmission()
Expect(p).ToNot(BeNil())
Expect(p.PacketNumber).To(Equal(protocol.PacketNumber(3)))
Expect(handler.cryptoCount).To(BeEquivalentTo(1))
handler.SentPacket(cryptoPacket(&Packet{PacketNumber: 4, SendTime: lastCryptoPacketSendTime}))
// make sure the exponential backoff is used
Expect(handler.GetAlarmTimeout().Sub(lastCryptoPacketSendTime)).To(Equal(4 * time.Minute))
})
It("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("PROTOCOL_VIOLATION: Received ACK for an unsent packet"))
})
It("deletes Initial packets", func() {
for i := protocol.PacketNumber(0); i < 6; i++ {
p := ackElicitingPacket(&Packet{PacketNumber: i, EncryptionLevel: protocol.EncryptionInitial})
handler.SentPacket(p)
}
for i := protocol.PacketNumber(0); i < 10; i++ {
p := ackElicitingPacket(&Packet{PacketNumber: i, EncryptionLevel: protocol.EncryptionHandshake})
handler.SentPacket(p)
}
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(16)))
handler.queuePacketForRetransmission(getPacket(1, protocol.EncryptionInitial), handler.getPacketNumberSpace(protocol.EncryptionInitial))
lostPacket := getPacket(3, protocol.EncryptionHandshake)
handler.queuePacketForRetransmission(lostPacket, handler.getPacketNumberSpace(protocol.EncryptionHandshake))
handler.DropPackets(protocol.EncryptionInitial)
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(10)))
Expect(handler.initialPackets).To(BeNil())
Expect(handler.handshakePackets.history.Len()).ToNot(BeZero())
packet := handler.DequeuePacketForRetransmission()
Expect(packet).To(Equal(lostPacket))
})
It("deletes Handshake packets", func() {
for i := protocol.PacketNumber(0); i < 6; i++ {
p := ackElicitingPacket(&Packet{PacketNumber: i, EncryptionLevel: protocol.EncryptionHandshake})
handler.SentPacket(p)
}
for i := protocol.PacketNumber(0); i < 10; i++ {
p := ackElicitingPacket(&Packet{PacketNumber: i, EncryptionLevel: protocol.Encryption1RTT})
handler.SentPacket(p)
}
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(16)))
handler.queuePacketForRetransmission(getPacket(1, protocol.EncryptionHandshake), handler.getPacketNumberSpace(protocol.EncryptionInitial))
lostPacket := getPacket(3, protocol.Encryption1RTT)
handler.queuePacketForRetransmission(lostPacket, handler.getPacketNumberSpace(protocol.EncryptionHandshake))
handler.DropPackets(protocol.EncryptionHandshake)
Expect(handler.bytesInFlight).To(Equal(protocol.ByteCount(10)))
Expect(handler.handshakePackets).To(BeNil())
packet := handler.DequeuePacketForRetransmission()
Expect(packet).To(Equal(lostPacket))
})
})
Context("peeking and popping packet number", func() {
It("peeks and pops the initial packet number", func() {
pn, _ := handler.PeekPacketNumber(protocol.EncryptionInitial)
Expect(pn).To(Equal(protocol.PacketNumber(42)))
Expect(handler.PopPacketNumber(protocol.EncryptionInitial)).To(Equal(protocol.PacketNumber(42)))
})
It("peeks and pops beyond the initial packet number", func() {
Expect(handler.PopPacketNumber(protocol.EncryptionInitial)).To(Equal(protocol.PacketNumber(42)))
Expect(handler.PopPacketNumber(protocol.EncryptionInitial)).To(BeNumerically(">", 42))
})
It("starts at 0 for handshake and application-data packet number space", func() {
pn, _ := handler.PeekPacketNumber(protocol.EncryptionHandshake)
Expect(pn).To(BeZero())
Expect(handler.PopPacketNumber(protocol.EncryptionHandshake)).To(BeZero())
pn, _ = handler.PeekPacketNumber(protocol.Encryption1RTT)
Expect(pn).To(BeZero())
Expect(handler.PopPacketNumber(protocol.Encryption1RTT)).To(BeZero())
})
})
Context("resetting for retry", func() {
It("queues outstanding packets for retransmission and cancels alarms", func() {
packet := &Packet{
PacketNumber: 42,
EncryptionLevel: protocol.EncryptionInitial,
Frames: []wire.Frame{&wire.CryptoFrame{Data: []byte("foobar")}},
Length: 100,
}
handler.SentPacket(packet)
Expect(handler.GetAlarmTimeout()).ToNot(BeZero())
Expect(handler.bytesInFlight).ToNot(BeZero())
Expect(handler.DequeuePacketForRetransmission()).To(BeNil())
Expect(handler.SendMode()).To(Equal(SendAny))
// now receive a Retry
Expect(handler.ResetForRetry()).To(Succeed())
Expect(handler.bytesInFlight).To(BeZero())
Expect(handler.GetAlarmTimeout()).To(BeZero())
Expect(handler.SendMode()).To(Equal(SendRetransmission))
p := handler.DequeuePacketForRetransmission()
Expect(p.PacketNumber).To(Equal(packet.PacketNumber))
Expect(p.Frames).To(Equal(packet.Frames))
})
})
})