| // Copyright 2023 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| //go:build go1.21 |
| |
| package quic |
| |
| import ( |
| "fmt" |
| "testing" |
| "time" |
| ) |
| |
| func TestLossAntiAmplificationLimit(t *testing.T) { |
| test := newLossTest(t, serverSide, lossTestOpts{}) |
| test.datagramReceived(1200) |
| t.Logf("# consume anti-amplification capacity in a mix of packets") |
| test.send(initialSpace, 0, sentPacket{ |
| size: 1200, |
| ackEliciting: true, |
| inFlight: true, |
| }) |
| test.send(initialSpace, 1, sentPacket{ |
| size: 1200, |
| ackEliciting: false, |
| inFlight: false, |
| }) |
| test.send(initialSpace, 2, sentPacket{ |
| size: 1200, |
| ackEliciting: false, |
| inFlight: true, |
| }) |
| t.Logf("# send blocked by anti-amplification limit") |
| test.wantSendLimit(ccBlocked) |
| |
| t.Logf("# receiving a datagram unblocks server") |
| test.datagramReceived(100) |
| test.wantSendLimit(ccOK) |
| |
| t.Logf("# validating client address removes anti-amplification limit") |
| test.validateClientAddress() |
| test.wantSendLimit(ccOK) |
| } |
| |
| func TestLossRTTSampleNotGenerated(t *testing.T) { |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| test.send(initialSpace, 0, 1) |
| test.send(initialSpace, 2, sentPacket{ |
| ackEliciting: false, |
| inFlight: false, |
| }) |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{1, 2}) |
| test.wantAck(initialSpace, 1) |
| test.wantVar("latest_rtt", 10*time.Millisecond) |
| t.Logf("# smoothed_rtt = latest_rtt") |
| test.wantVar("smoothed_rtt", 10*time.Millisecond) |
| t.Logf("# rttvar = latest_rtt / 2") |
| test.wantVar("rttvar", 5*time.Millisecond) |
| |
| // "...an ACK frame SHOULD NOT be used to update RTT estimates if |
| // it does not newly acknowledge the largest acknowledged packet." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-5.1-6 |
| t.Logf("# acks for older packets do not generate an RTT sample") |
| test.advance(1 * time.Millisecond) |
| test.ack(initialSpace, 1*time.Millisecond, i64range[packetNumber]{0, 2}) |
| test.wantAck(initialSpace, 0) |
| test.wantVar("smoothed_rtt", 10*time.Millisecond) |
| |
| // "An RTT sample MUST NOT be generated on receiving an ACK frame |
| // that does not newly acknowledge at least one ack-eliciting packet." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-5.1-7 |
| t.Logf("# acks for non-ack-eliciting packets do not generate an RTT sample") |
| test.advance(1 * time.Millisecond) |
| test.ack(initialSpace, 1*time.Millisecond, i64range[packetNumber]{0, 3}) |
| test.wantAck(initialSpace, 2) |
| test.wantVar("smoothed_rtt", 10*time.Millisecond) |
| } |
| |
| func TestLossMinRTT(t *testing.T) { |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| |
| // "min_rtt MUST be set to the latest_rtt on the first RTT sample." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-5.2-2 |
| t.Logf("# min_rtt set on first sample") |
| test.send(initialSpace, 0) |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| test.wantVar("min_rtt", 10*time.Millisecond) |
| |
| // "min_rtt MUST be set to the lesser of min_rtt and latest_rtt [...] |
| // on all other samples." |
| t.Logf("# min_rtt does not increase") |
| test.send(initialSpace, 1) |
| test.advance(20 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 2}) |
| test.wantAck(initialSpace, 1) |
| test.wantVar("min_rtt", 10*time.Millisecond) |
| |
| t.Logf("# min_rtt decreases") |
| test.send(initialSpace, 2) |
| test.advance(5 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 3}) |
| test.wantAck(initialSpace, 2) |
| test.wantVar("min_rtt", 5*time.Millisecond) |
| } |
| |
| func TestLossMinRTTAfterCongestion(t *testing.T) { |
| // "Endpoints SHOULD set the min_rtt to the newest RTT sample |
| // after persistent congestion is established." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-5.2-5 |
| test := newLossTest(t, clientSide, lossTestOpts{ |
| maxDatagramSize: 1200, |
| }) |
| t.Logf("# establish initial RTT sample") |
| test.send(initialSpace, 0, testSentPacketSize(1200)) |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| test.wantVar("min_rtt", 10*time.Millisecond) |
| |
| t.Logf("# send two packets spanning persistent congestion duration") |
| test.send(initialSpace, 1, testSentPacketSize(1200)) |
| t.Logf("# 2000ms >> persistent congestion duration") |
| test.advance(2000 * time.Millisecond) |
| test.wantPTOExpired() |
| test.send(initialSpace, 2, testSentPacketSize(1200)) |
| |
| t.Logf("# trigger loss of previous packets") |
| test.advance(10 * time.Millisecond) |
| test.send(initialSpace, 3, testSentPacketSize(1200)) |
| test.advance(20 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{3, 4}) |
| test.wantAck(initialSpace, 3) |
| test.wantLoss(initialSpace, 1, 2) |
| t.Logf("# persistent congestion detected") |
| |
| test.send(initialSpace, 4, testSentPacketSize(1200)) |
| test.advance(20 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{4, 5}) |
| test.wantAck(initialSpace, 4) |
| |
| t.Logf("# min_rtt set from first sample after persistent congestion") |
| test.wantVar("min_rtt", 20*time.Millisecond) |
| } |
| |
| func TestLossInitialRTTSample(t *testing.T) { |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| test.setMaxAckDelay(2 * time.Millisecond) |
| t.Logf("# initial smoothed_rtt and rtt values") |
| test.wantVar("smoothed_rtt", 333*time.Millisecond) |
| test.wantVar("rttvar", 333*time.Millisecond/2) |
| |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-5.3-11 |
| t.Logf("# first RTT sample") |
| test.send(initialSpace, 0) |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| test.wantVar("latest_rtt", 10*time.Millisecond) |
| t.Logf("# smoothed_rtt = latest_rtt") |
| test.wantVar("smoothed_rtt", 10*time.Millisecond) |
| t.Logf("# rttvar = latest_rtt / 2") |
| test.wantVar("rttvar", 5*time.Millisecond) |
| } |
| |
| func TestLossSmoothedRTTIgnoresMaxAckDelayBeforeHandshakeConfirmed(t *testing.T) { |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| test.setMaxAckDelay(1 * time.Millisecond) |
| test.send(initialSpace, 0) |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| smoothedRTT := 10 * time.Millisecond |
| rttvar := 5 * time.Millisecond |
| |
| // "[...] an endpoint [...] SHOULD ignore the peer's max_ack_delay |
| // until the handshake is confirmed [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-5.3-7.2 |
| t.Logf("# subsequent RTT sample") |
| test.send(handshakeSpace, 0) |
| test.advance(20 * time.Millisecond) |
| test.ack(handshakeSpace, 10*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(handshakeSpace, 0) |
| test.wantVar("latest_rtt", 20*time.Millisecond) |
| t.Logf("# ack_delay > max_ack_delay") |
| t.Logf("# handshake not confirmed, so ignore max_ack_delay") |
| t.Logf("# adjusted_rtt = latest_rtt - ackDelay") |
| adjustedRTT := 10 * time.Millisecond |
| t.Logf("# smoothed_rtt = 7/8 * smoothed_rtt + 1/8 * adjusted_rtt") |
| smoothedRTT = (7*smoothedRTT + adjustedRTT) / 8 |
| test.wantVar("smoothed_rtt", smoothedRTT) |
| rttvarSample := abs(smoothedRTT - adjustedRTT) |
| t.Logf("# rttvar_sample = abs(smoothed_rtt - adjusted_rtt) = %v", rttvarSample) |
| t.Logf("# rttvar = 3/4 * rttvar + 1/4 * rttvar_sample") |
| rttvar = (3*rttvar + rttvarSample) / 4 |
| test.wantVar("rttvar", rttvar) |
| } |
| |
| func TestLossSmoothedRTTUsesMaxAckDelayAfterHandshakeConfirmed(t *testing.T) { |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| test.setMaxAckDelay(25 * time.Millisecond) |
| test.send(initialSpace, 0) |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| smoothedRTT := 10 * time.Millisecond |
| rttvar := 5 * time.Millisecond |
| |
| test.confirmHandshake() |
| |
| // "[...] an endpoint [...] MUST use the lesser of the acknowledgment |
| // delay and the peer's max_ack_delay after the handshake is confirmed [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-5.3-7.3 |
| t.Logf("# subsequent RTT sample") |
| test.send(handshakeSpace, 0) |
| test.advance(50 * time.Millisecond) |
| test.ack(handshakeSpace, 40*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(handshakeSpace, 0) |
| test.wantVar("latest_rtt", 50*time.Millisecond) |
| t.Logf("# ack_delay > max_ack_delay") |
| t.Logf("# handshake confirmed, so adjusted_rtt clamps to max_ack_delay") |
| t.Logf("# adjusted_rtt = max_ack_delay") |
| adjustedRTT := 25 * time.Millisecond |
| rttvarSample := abs(smoothedRTT - adjustedRTT) |
| t.Logf("# rttvar_sample = abs(smoothed_rtt - adjusted_rtt) = %v", rttvarSample) |
| t.Logf("# rttvar = 3/4 * rttvar + 1/4 * rttvar_sample") |
| rttvar = (3*rttvar + rttvarSample) / 4 |
| test.wantVar("rttvar", rttvar) |
| t.Logf("# smoothed_rtt = 7/8 * smoothed_rtt + 1/8 * adjusted_rtt") |
| smoothedRTT = (7*smoothedRTT + adjustedRTT) / 8 |
| test.wantVar("smoothed_rtt", smoothedRTT) |
| } |
| |
| func TestLossAckDelayReducesRTTBelowMinRTT(t *testing.T) { |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| test.send(initialSpace, 0) |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| smoothedRTT := 10 * time.Millisecond |
| rttvar := 5 * time.Millisecond |
| |
| // "[...] an endpoint [...] MUST NOT subtract the acknowledgment delay |
| // from the RTT sample if the resulting value is smaller than the min_rtt." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-5.3-7.4 |
| t.Logf("# subsequent RTT sample") |
| test.send(handshakeSpace, 0) |
| test.advance(12 * time.Millisecond) |
| test.ack(handshakeSpace, 4*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(handshakeSpace, 0) |
| test.wantVar("latest_rtt", 12*time.Millisecond) |
| t.Logf("# latest_rtt - ack_delay < min_rtt, so adjusted_rtt = latest_rtt") |
| adjustedRTT := 12 * time.Millisecond |
| rttvarSample := abs(smoothedRTT - adjustedRTT) |
| t.Logf("# rttvar_sample = abs(smoothed_rtt - adjusted_rtt) = %v", rttvarSample) |
| t.Logf("# rttvar = 3/4 * rttvar + 1/4 * rttvar_sample") |
| rttvar = (3*rttvar + rttvarSample) / 4 |
| test.wantVar("rttvar", rttvar) |
| t.Logf("# smoothed_rtt = 7/8 * smoothed_rtt + 1/8 * adjusted_rtt") |
| smoothedRTT = (7*smoothedRTT + adjustedRTT) / 8 |
| test.wantVar("smoothed_rtt", smoothedRTT) |
| } |
| |
| func TestLossPacketThreshold(t *testing.T) { |
| // "[...] the packet was sent kPacketThreshold packets before an |
| // acknowledged packet [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.1.1 |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| t.Logf("# acking a packet triggers loss of packets sent kPacketThreshold earlier") |
| test.send(appDataSpace, 0, 1, 2, 3, 4, 5, 6) |
| test.ack(appDataSpace, 0*time.Millisecond, i64range[packetNumber]{4, 5}) |
| test.wantAck(appDataSpace, 4) |
| test.wantLoss(appDataSpace, 0, 1) |
| } |
| |
| func TestLossOutOfOrderAcks(t *testing.T) { |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| t.Logf("# out of order acks, no loss") |
| test.send(appDataSpace, 0, 1, 2) |
| test.ack(appDataSpace, 0*time.Millisecond, i64range[packetNumber]{2, 3}) |
| test.wantAck(appDataSpace, 2) |
| |
| test.ack(appDataSpace, 0*time.Millisecond, i64range[packetNumber]{1, 2}) |
| test.wantAck(appDataSpace, 1) |
| |
| test.ack(appDataSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(appDataSpace, 0) |
| } |
| |
| func TestLossSendAndAck(t *testing.T) { |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| test.send(appDataSpace, 0, 1, 2) |
| test.ack(appDataSpace, 0*time.Millisecond, i64range[packetNumber]{0, 3}) |
| test.wantAck(appDataSpace, 0, 1, 2) |
| // Redundant ACK doesn't trigger more ACK events. |
| // (If we did get an extra ACK, the test cleanup would notice and complain.) |
| test.ack(appDataSpace, 0*time.Millisecond, i64range[packetNumber]{0, 3}) |
| } |
| |
| func TestLossAckEveryOtherPacket(t *testing.T) { |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| test.send(appDataSpace, 0, 1, 2, 3, 4, 5, 6) |
| test.ack(appDataSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(appDataSpace, 0) |
| |
| test.ack(appDataSpace, 0*time.Millisecond, i64range[packetNumber]{2, 3}) |
| test.wantAck(appDataSpace, 2) |
| |
| test.ack(appDataSpace, 0*time.Millisecond, i64range[packetNumber]{4, 5}) |
| test.wantAck(appDataSpace, 4) |
| test.wantLoss(appDataSpace, 1) |
| |
| test.ack(appDataSpace, 0*time.Millisecond, i64range[packetNumber]{6, 7}) |
| test.wantAck(appDataSpace, 6) |
| test.wantLoss(appDataSpace, 3) |
| } |
| |
| func TestLossMultipleSpaces(t *testing.T) { |
| // "Loss detection is separate per packet number space [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6-3 |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| t.Logf("# send packets in different spaces") |
| test.send(initialSpace, 0, 1, 2) |
| test.send(handshakeSpace, 0, 1, 2) |
| test.send(appDataSpace, 0, 1, 2) |
| |
| t.Logf("# ack one packet in each space") |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{1, 2}) |
| test.wantAck(initialSpace, 1) |
| |
| test.ack(handshakeSpace, 0*time.Millisecond, i64range[packetNumber]{1, 2}) |
| test.wantAck(handshakeSpace, 1) |
| |
| test.ack(appDataSpace, 0*time.Millisecond, i64range[packetNumber]{1, 2}) |
| test.wantAck(appDataSpace, 1) |
| |
| t.Logf("# send more packets") |
| test.send(initialSpace, 3, 4, 5) |
| test.send(handshakeSpace, 3, 4, 5) |
| test.send(appDataSpace, 3, 4, 5) |
| |
| t.Logf("# ack the last packet, triggering loss") |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{5, 6}) |
| test.wantAck(initialSpace, 5) |
| test.wantLoss(initialSpace, 0, 2) |
| |
| test.ack(handshakeSpace, 0*time.Millisecond, i64range[packetNumber]{5, 6}) |
| test.wantAck(handshakeSpace, 5) |
| test.wantLoss(handshakeSpace, 0, 2) |
| |
| test.ack(appDataSpace, 0*time.Millisecond, i64range[packetNumber]{5, 6}) |
| test.wantAck(appDataSpace, 5) |
| test.wantLoss(appDataSpace, 0, 2) |
| } |
| |
| func TestLossTimeThresholdFirstPacketLost(t *testing.T) { |
| // "[...] the packet [...] was sent long enough in the past." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.1-3.2 |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| t.Logf("# packet 0 lost after time threshold passes") |
| test.send(initialSpace, 0, 1) |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{1, 2}) |
| test.wantAck(initialSpace, 1) |
| |
| t.Logf("# latest_rtt == smoothed_rtt") |
| test.wantVar("smoothed_rtt", 10*time.Millisecond) |
| test.wantVar("latest_rtt", 10*time.Millisecond) |
| t.Logf("# timeout = 9/8 * max(smoothed_rtt, latest_rtt) - time_since_packet_sent") |
| test.wantTimeout(((10 * time.Millisecond * 9) / 8) - 10*time.Millisecond) |
| |
| test.advanceToLossTimer() |
| test.wantLoss(initialSpace, 0) |
| } |
| |
| func TestLossTimeThreshold(t *testing.T) { |
| // "The time threshold is: |
| // max(kTimeThreshold * max(smoothed_rtt, latest_rtt), kGranularity)" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.1.2-2 |
| for _, tc := range []struct { |
| name string |
| initialRTT time.Duration |
| latestRTT time.Duration |
| wantTimeout time.Duration |
| }{{ |
| name: "rtt increasing", |
| initialRTT: 10 * time.Millisecond, |
| latestRTT: 20 * time.Millisecond, |
| wantTimeout: 20 * time.Millisecond * 9 / 8, |
| }, { |
| name: "rtt decreasing", |
| initialRTT: 10 * time.Millisecond, |
| latestRTT: 5 * time.Millisecond, |
| wantTimeout: ((7*10*time.Millisecond + 5*time.Millisecond) / 8) * 9 / 8, |
| }, { |
| name: "rtt less than timer granularity", |
| initialRTT: 500 * time.Microsecond, |
| latestRTT: 500 * time.Microsecond, |
| wantTimeout: 1 * time.Millisecond, |
| }} { |
| t.Run(tc.name, func(t *testing.T) { |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| t.Logf("# first ack establishes smoothed_rtt") |
| test.send(initialSpace, 0) |
| test.advance(tc.initialRTT) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| |
| t.Logf("# ack of packet 2 starts loss timer for packet 1") |
| test.send(initialSpace, 1, 2) |
| test.advance(tc.latestRTT) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{2, 3}) |
| test.wantAck(initialSpace, 2) |
| |
| t.Logf("# smoothed_rtt = %v", test.c.rtt.smoothedRTT) |
| t.Logf("# latest_rtt = %v", test.c.rtt.latestRTT) |
| t.Logf("# timeout = max(9/8 * max(smoothed_rtt, latest_rtt), 1ms)") |
| t.Logf("# (measured since packet 1 sent)") |
| test.wantTimeout(tc.wantTimeout - tc.latestRTT) |
| |
| t.Logf("# advancing to the loss time causes loss of packet 1") |
| test.advanceToLossTimer() |
| test.wantLoss(initialSpace, 1) |
| }) |
| } |
| } |
| |
| func TestLossPTONotAckEliciting(t *testing.T) { |
| // "When an ack-eliciting packet is transmitted, |
| // the sender schedules a timer for the PTO period [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.2.1-1 |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| t.Logf("# PTO timer for first packet") |
| test.send(initialSpace, 0) |
| test.wantVar("smoothed_rtt", 333*time.Millisecond) // initial value |
| test.wantVar("rttvar", 333*time.Millisecond/2) // initial value |
| t.Logf("# PTO = smoothed_rtt + max(4*rttvar, 1ms)") |
| test.wantTimeout(999 * time.Millisecond) |
| |
| t.Logf("# sending a non-ack-eliciting packet doesn't adjust PTO") |
| test.advance(333 * time.Millisecond) |
| test.send(initialSpace, 1, sentPacket{ |
| ackEliciting: false, |
| }) |
| test.wantVar("smoothed_rtt", 333*time.Millisecond) // unchanged |
| test.wantVar("rttvar", 333*time.Millisecond/2) // unchanged |
| test.wantTimeout(666 * time.Millisecond) |
| } |
| |
| func TestLossPTOMaxAckDelay(t *testing.T) { |
| // "When the PTO is armed for Initial or Handshake packet number spaces, |
| // the max_ack_delay in the PTO period computation is set to 0 [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.2.1-4 |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| t.Logf("# PTO timer for first packet") |
| test.send(initialSpace, 0) |
| test.wantVar("smoothed_rtt", 333*time.Millisecond) // initial value |
| test.wantVar("rttvar", 333*time.Millisecond/2) // initial value |
| t.Logf("# PTO = smoothed_rtt + max(4*rttvar, 1ms)") |
| test.wantTimeout(999 * time.Millisecond) |
| |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| |
| t.Logf("# PTO timer for handshake packet") |
| test.send(handshakeSpace, 0) |
| test.wantVar("smoothed_rtt", 10*time.Millisecond) |
| test.wantVar("rttvar", 5*time.Millisecond) |
| t.Logf("# PTO = smoothed_rtt + max(4*rttvar, 1ms)") |
| test.wantTimeout(30 * time.Millisecond) |
| |
| test.advance(10 * time.Millisecond) |
| test.ack(handshakeSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(handshakeSpace, 0) |
| test.confirmHandshake() |
| |
| t.Logf("# PTO timer for appdata packet") |
| test.send(appDataSpace, 0) |
| test.wantVar("smoothed_rtt", 10*time.Millisecond) |
| test.wantVar("rttvar", 3750*time.Microsecond) |
| t.Logf("# PTO = smoothed_rtt + max(4*rttvar, 1ms) + max_ack_delay (25ms)") |
| test.wantTimeout(50 * time.Millisecond) |
| } |
| |
| func TestLossPTOUnderTimerGranularity(t *testing.T) { |
| // "The PTO period MUST be at least kGranularity [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.2.1-5 |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| test.send(initialSpace, 0) |
| test.advance(10 * time.Microsecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| |
| test.send(initialSpace, 1) |
| test.wantVar("smoothed_rtt", 10*time.Microsecond) |
| test.wantVar("rttvar", 5*time.Microsecond) |
| t.Logf("# PTO = smoothed_rtt + max(4*rttvar, 1ms)") |
| test.wantTimeout(10*time.Microsecond + 1*time.Millisecond) |
| } |
| |
| func TestLossPTOMultipleSpaces(t *testing.T) { |
| // "[...] the timer MUST be set to the earlier value of the Initial and Handshake |
| // packet number spaces." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.2.1-6 |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| t.Logf("# PTO timer for first packet") |
| test.send(initialSpace, 0) |
| test.wantVar("smoothed_rtt", 333*time.Millisecond) // initial value |
| test.wantVar("rttvar", 333*time.Millisecond/2) // initial value |
| t.Logf("# PTO = smoothed_rtt + max(4*rttvar, 1ms)") |
| test.wantTimeout(999 * time.Millisecond) |
| |
| t.Logf("# Initial and Handshake packets in flight, first takes precedence") |
| test.advance(333 * time.Millisecond) |
| test.send(handshakeSpace, 0) |
| test.wantTimeout(666 * time.Millisecond) |
| |
| t.Logf("# Initial packet acked, Handshake PTO timer armed") |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| test.wantTimeout(999 * time.Millisecond) |
| |
| t.Logf("# send Initial, earlier Handshake PTO takes precedence") |
| test.advance(333 * time.Millisecond) |
| test.send(initialSpace, 1) |
| test.wantTimeout(666 * time.Millisecond) |
| } |
| |
| func TestLossPTOHandshakeConfirmation(t *testing.T) { |
| // "An endpoint MUST NOT set its PTO timer for the Application Data |
| // packet number space until the handshake is confirmed." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.2.1-7 |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| test.send(initialSpace, 0) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| |
| test.send(handshakeSpace, 0) |
| test.ack(handshakeSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(handshakeSpace, 0) |
| |
| test.send(appDataSpace, 0) |
| test.wantNoTimeout() |
| } |
| |
| func TestLossPTOBackoffDoubles(t *testing.T) { |
| // "When a PTO timer expires, the PTO backoff MUST be increased, |
| // resulting in the PTO period being set to twice its current value." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.2.1-9 |
| test := newLossTest(t, serverSide, lossTestOpts{}) |
| test.datagramReceived(1200) |
| test.send(initialSpace, 0) |
| test.wantVar("smoothed_rtt", 333*time.Millisecond) // initial value |
| test.wantVar("rttvar", 333*time.Millisecond/2) // initial value |
| t.Logf("# PTO = smoothed_rtt + max(4*rttvar, 1ms)") |
| test.wantTimeout(999 * time.Millisecond) |
| |
| t.Logf("# wait for PTO timer expiration") |
| test.advanceToLossTimer() |
| test.wantPTOExpired() |
| test.wantNoTimeout() |
| |
| t.Logf("# PTO timer doubles") |
| test.send(initialSpace, 1) |
| test.wantTimeout(2 * 999 * time.Millisecond) |
| test.advanceToLossTimer() |
| test.wantPTOExpired() |
| test.wantNoTimeout() |
| |
| t.Logf("# PTO timer doubles again") |
| test.send(initialSpace, 2) |
| test.wantTimeout(4 * 999 * time.Millisecond) |
| test.advanceToLossTimer() |
| test.wantPTOExpired() |
| test.wantNoTimeout() |
| } |
| |
| func TestLossPTOBackoffResetOnAck(t *testing.T) { |
| // "The PTO backoff factor is reset when an acknowledgment is received [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.2.1-9 |
| test := newLossTest(t, serverSide, lossTestOpts{}) |
| test.datagramReceived(1200) |
| |
| t.Logf("# first ack establishes smoothed_rtt = 10ms") |
| test.send(initialSpace, 0) |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| t.Logf("# set rttvar for simplicity") |
| test.setRTTVar(0) |
| |
| t.Logf("# send packet 1 and wait for PTO") |
| test.send(initialSpace, 1) |
| test.wantTimeout(11 * time.Millisecond) |
| test.advanceToLossTimer() |
| test.wantPTOExpired() |
| test.wantNoTimeout() |
| |
| t.Logf("# send packet 2 & 3, PTO doubles") |
| test.send(initialSpace, 2, 3) |
| test.wantTimeout(22 * time.Millisecond) |
| |
| test.advance(10 * time.Millisecond) |
| t.Logf("# check remaining PTO (22ms - 10ms elapsed)") |
| test.wantTimeout(12 * time.Millisecond) |
| |
| t.Logf("# ACK to packet 2 resets PTO") |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 3}) |
| test.wantAck(initialSpace, 1) |
| test.wantAck(initialSpace, 2) |
| |
| t.Logf("# check remaining PTO (11ms - 10ms elapsed)") |
| test.wantTimeout(1 * time.Millisecond) |
| } |
| |
| func TestLossPTOBackoffNotResetOnClientInitialAck(t *testing.T) { |
| // "[...] a client does not reset the PTO backoff factor on |
| // receiving acknowledgments in Initial packets." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.2.1-9 |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| |
| t.Logf("# first ack establishes smoothed_rtt = 10ms") |
| test.send(initialSpace, 0) |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| t.Logf("# set rttvar for simplicity") |
| test.setRTTVar(0) |
| |
| t.Logf("# send packet 1 and wait for PTO") |
| test.send(initialSpace, 1) |
| test.wantTimeout(11 * time.Millisecond) |
| test.advanceToLossTimer() |
| test.wantPTOExpired() |
| test.wantNoTimeout() |
| |
| t.Logf("# send more packets, PTO doubles") |
| test.send(initialSpace, 2, 3) |
| test.send(handshakeSpace, 0) |
| test.wantTimeout(22 * time.Millisecond) |
| |
| test.advance(10 * time.Millisecond) |
| t.Logf("# check remaining PTO (22ms - 10ms elapsed)") |
| test.wantTimeout(12 * time.Millisecond) |
| |
| // TODO: Is this right? 6.2.1-9 says we don't reset the PTO *backoff*, not the PTO. |
| // 6.2.1-8 says we reset the PTO timer when an ack-eliciting packet is sent *or |
| // acknowledged*, but the pseudocode in appendix A doesn't appear to do the latter. |
| t.Logf("# ACK to Initial packet does not reset PTO for client") |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 3}) |
| test.wantAck(initialSpace, 1) |
| test.wantAck(initialSpace, 2) |
| t.Logf("# check remaining PTO (22ms - 10ms elapsed)") |
| test.wantTimeout(12 * time.Millisecond) |
| |
| t.Logf("# ACK to handshake packet does reset PTO") |
| test.ack(handshakeSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(handshakeSpace, 0) |
| t.Logf("# check remaining PTO (12ms - 10ms elapsed)") |
| test.wantTimeout(1 * time.Millisecond) |
| } |
| |
| func TestLossPTONotSetWhenLossTimerSet(t *testing.T) { |
| // "The PTO timer MUST NOT be set if a timer is set |
| // for time threshold loss detection [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.2.1-12 |
| test := newLossTest(t, serverSide, lossTestOpts{}) |
| test.datagramReceived(1200) |
| t.Logf("# PTO timer set for first packets sent") |
| test.send(initialSpace, 0, 1) |
| test.wantVar("smoothed_rtt", 333*time.Millisecond) // initial value |
| test.wantVar("rttvar", 333*time.Millisecond/2) // initial value |
| t.Logf("# PTO = smoothed_rtt + max(4*rttvar, 1ms)") |
| test.wantTimeout(999 * time.Millisecond) |
| |
| t.Logf("# ack of packet 1 starts loss timer for 0, PTO overidden") |
| test.advance(333 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{1, 2}) |
| test.wantAck(initialSpace, 1) |
| |
| t.Logf("# latest_rtt == smoothed_rtt") |
| test.wantVar("smoothed_rtt", 333*time.Millisecond) |
| test.wantVar("latest_rtt", 333*time.Millisecond) |
| t.Logf("# timeout = 9/8 * max(smoothed_rtt, latest_rtt) - time_since_packet_sent") |
| test.wantTimeout(((333 * time.Millisecond * 9) / 8) - 333*time.Millisecond) |
| } |
| |
| func TestLossDiscardingKeysResetsTimers(t *testing.T) { |
| // "When Initial or Handshake keys are discarded, |
| // the PTO and loss detection timers MUST be reset" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.2.2-3 |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| |
| t.Logf("# handshake packet sent 1ms after initial") |
| test.send(initialSpace, 0, 1) |
| test.advance(1 * time.Millisecond) |
| test.send(handshakeSpace, 0, 1) |
| test.advance(9 * time.Millisecond) |
| |
| t.Logf("# ack of Initial packet 2 starts loss timer for packet 1") |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{1, 2}) |
| test.wantAck(initialSpace, 1) |
| |
| test.advance(1 * time.Millisecond) |
| t.Logf("# smoothed_rtt = %v", 10*time.Millisecond) |
| t.Logf("# latest_rtt = %v", 10*time.Millisecond) |
| t.Logf("# timeout = max(9/8 * max(smoothed_rtt, latest_rtt), 1ms)") |
| t.Logf("# (measured since Initial packet 1 sent)") |
| test.wantTimeout((10 * time.Millisecond * 9 / 8) - 11*time.Millisecond) |
| |
| t.Logf("# ack of Handshake packet 2 starts loss timer for packet 1") |
| test.ack(handshakeSpace, 0*time.Millisecond, i64range[packetNumber]{1, 2}) |
| test.wantAck(handshakeSpace, 1) |
| |
| t.Logf("# dropping Initial keys sets timer to Handshake timeout") |
| test.discardKeys(initialSpace) |
| test.wantTimeout((10 * time.Millisecond * 9 / 8) - 10*time.Millisecond) |
| } |
| |
| func TestLossNoPTOAtAntiAmplificationLimit(t *testing.T) { |
| // "If no additional data can be sent [because the server is at the |
| // anti-amplification limit], the server's PTO timer MUST NOT be armed [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.2.2.1-1 |
| test := newLossTest(t, serverSide, lossTestOpts{ |
| maxDatagramSize: 1 << 20, // large initial congestion window |
| }) |
| test.datagramReceived(1200) |
| test.send(initialSpace, 0, sentPacket{ |
| ackEliciting: true, |
| inFlight: true, |
| size: 1200, |
| }) |
| test.wantTimeout(999 * time.Millisecond) |
| |
| t.Logf("PTO timer should be disabled when at the anti-amplification limit") |
| test.send(initialSpace, 1, sentPacket{ |
| ackEliciting: false, |
| inFlight: true, |
| size: 2 * 1200, |
| }) |
| test.wantNoTimeout() |
| |
| // "When the server receives a datagram from the client, the amplification |
| // limit is increased and the server resets the PTO timer." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.2.2.1-2 |
| t.Logf("PTO timer should be reset when datagrams are received") |
| test.datagramReceived(1200) |
| test.wantTimeout(999 * time.Millisecond) |
| |
| // "If the PTO timer is then set to a time in the past, it is executed immediately." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.2.2.1-2 |
| test.send(initialSpace, 2, sentPacket{ |
| ackEliciting: true, |
| inFlight: true, |
| size: 3 * 1200, |
| }) |
| test.wantNoTimeout() |
| t.Logf("resetting expired PTO timer should exeute immediately") |
| test.advance(1000 * time.Millisecond) |
| test.datagramReceived(1200) |
| test.wantPTOExpired() |
| test.wantNoTimeout() |
| } |
| |
| func TestLossClientSetsPTOWhenHandshakeUnacked(t *testing.T) { |
| // "[...] the client MUST set the PTO timer if the client has not |
| // received an acknowledgment for any of its Handshake packets and |
| // the handshake is not confirmed [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.2.2.1-3 |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| test.send(initialSpace, 0) |
| |
| test.wantVar("smoothed_rtt", 333*time.Millisecond) // initial value |
| test.wantVar("rttvar", 333*time.Millisecond/2) // initial value |
| t.Logf("# PTO = smoothed_rtt + max(4*rttvar, 1ms)") |
| test.wantTimeout(999 * time.Millisecond) |
| |
| test.advance(333 * time.Millisecond) |
| test.wantTimeout(666 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| t.Logf("# PTO timer set for a client before handshake ack even if no packets in flight") |
| test.wantTimeout(999 * time.Millisecond) |
| |
| test.advance(333 * time.Millisecond) |
| test.wantTimeout(666 * time.Millisecond) |
| } |
| |
| func TestLossKeysDiscarded(t *testing.T) { |
| // "The sender MUST discard all recovery state associated with |
| // [packets in number spaces with discarded keys] and MUST remove |
| // them from the count of bytes in flight." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-6.4-1 |
| test := newLossTest(t, clientSide, lossTestOpts{}) |
| test.send(initialSpace, 0, testSentPacketSize(1200)) |
| test.send(handshakeSpace, 0, testSentPacketSize(600)) |
| test.wantVar("bytes_in_flight", 1800) |
| |
| test.discardKeys(initialSpace) |
| test.wantVar("bytes_in_flight", 600) |
| |
| test.discardKeys(handshakeSpace) |
| test.wantVar("bytes_in_flight", 0) |
| } |
| |
| func TestLossInitialCongestionWindow(t *testing.T) { |
| // "Endpoints SHOULD use an initial congestion window of [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-7.2-1 |
| |
| // "[...] 10 times the maximum datagram size [...]" |
| test := newLossTest(t, clientSide, lossTestOpts{ |
| maxDatagramSize: 1200, |
| }) |
| t.Logf("# congestion_window = 10*max_datagram_size (1200)") |
| test.wantVar("congestion_window", 12000) |
| |
| // "[...] while limiting the window to the larger of 14720 bytes [...]" |
| test = newLossTest(t, clientSide, lossTestOpts{ |
| maxDatagramSize: 1500, |
| }) |
| t.Logf("# congestion_window limited to 14720 bytes") |
| test.wantVar("congestion_window", 14720) |
| |
| // "[...] or twice the maximum datagram size." |
| test = newLossTest(t, clientSide, lossTestOpts{ |
| maxDatagramSize: 10000, |
| }) |
| t.Logf("# congestion_window limited to 2*max_datagram_size (10000)") |
| test.wantVar("congestion_window", 20000) |
| |
| for _, tc := range []struct { |
| maxDatagramSize int |
| wantInitialBurst int |
| }{{ |
| // "[...] 10 times the maximum datagram size [...]" |
| maxDatagramSize: 1200, |
| wantInitialBurst: 12000, |
| }, { |
| // "[...] while limiting the window to the larger of 14720 bytes [...]" |
| maxDatagramSize: 1500, |
| wantInitialBurst: 14720, |
| }, { |
| // "[...] or twice the maximum datagram size." |
| maxDatagramSize: 10000, |
| wantInitialBurst: 20000, |
| }} { |
| t.Run(fmt.Sprintf("max_datagram_size=%v", tc.maxDatagramSize), func(t *testing.T) { |
| test := newLossTest(t, clientSide, lossTestOpts{ |
| maxDatagramSize: tc.maxDatagramSize, |
| }) |
| |
| var num packetNumber |
| window := tc.wantInitialBurst |
| for window >= tc.maxDatagramSize { |
| t.Logf("# %v bytes of initial congestion window remain", window) |
| test.send(initialSpace, num, sentPacket{ |
| ackEliciting: true, |
| inFlight: true, |
| size: tc.maxDatagramSize, |
| }) |
| window -= tc.maxDatagramSize |
| num++ |
| } |
| t.Logf("# congestion window (%v) < max_datagram_size, congestion control blocks send", window) |
| test.wantSendLimit(ccLimited) |
| }) |
| } |
| } |
| |
| func TestLossBytesInFlight(t *testing.T) { |
| test := newLossTest(t, clientSide, lossTestOpts{ |
| maxDatagramSize: 1200, |
| }) |
| t.Logf("# sent packets are added to bytes_in_flight") |
| test.wantVar("bytes_in_flight", 0) |
| test.send(initialSpace, 0, testSentPacketSize(1200)) |
| test.wantVar("bytes_in_flight", 1200) |
| test.send(initialSpace, 1, testSentPacketSize(800)) |
| test.wantVar("bytes_in_flight", 2000) |
| |
| t.Logf("# acked packets are removed from bytes_in_flight") |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{1, 2}) |
| test.wantAck(initialSpace, 1) |
| test.wantVar("bytes_in_flight", 1200) |
| |
| t.Logf("# lost packets are removed from bytes_in_flight") |
| test.advanceToLossTimer() |
| test.wantLoss(initialSpace, 0) |
| test.wantVar("bytes_in_flight", 0) |
| } |
| |
| func TestLossCongestionWindowLimit(t *testing.T) { |
| // "An endpoint MUST NOT send a packet if it would cause bytes_in_flight |
| // [...] to be larger than the congestion window [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-7-7 |
| test := newLossTest(t, clientSide, lossTestOpts{ |
| maxDatagramSize: 1200, |
| }) |
| t.Logf("# consume the initial congestion window") |
| test.send(initialSpace, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, testSentPacketSize(1200)) |
| test.wantSendLimit(ccLimited) |
| |
| t.Logf("# give the pacer bucket time to refill") |
| test.advance(333 * time.Millisecond) // initial RTT |
| |
| t.Logf("# sending limited by congestion window, not the pacer") |
| test.wantVar("congestion_window", 12000) |
| test.wantVar("bytes_in_flight", 12000) |
| test.wantVar("pacer_bucket", 12000) |
| test.wantSendLimit(ccLimited) |
| |
| t.Logf("# receiving an ack opens up the congestion window") |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| test.wantSendLimit(ccOK) |
| } |
| |
| func TestLossCongestionStates(t *testing.T) { |
| test := newLossTest(t, clientSide, lossTestOpts{ |
| maxDatagramSize: 1200, |
| }) |
| t.Logf("# consume the initial congestion window") |
| test.send(initialSpace, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, testSentPacketSize(1200)) |
| test.wantSendLimit(ccLimited) |
| test.wantVar("congestion_window", 12000) |
| |
| // "While a sender is in slow start, the congestion window |
| // increases by the number of bytes acknowledged [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-7.3.1-2 |
| test.advance(333 * time.Millisecond) |
| t.Logf("# congestion window increases by number of bytes acked (1200)") |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| test.wantVar("congestion_window", 13200) // 12000 + 1200 |
| |
| t.Logf("# congestion window increases by number of bytes acked (2400)") |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 3}) |
| test.wantAck(initialSpace, 1, 2) |
| test.wantVar("congestion_window", 15600) // 12000 + 3*1200 |
| |
| // TODO: ECN-CE count |
| |
| // "The sender MUST exit slow start and enter a recovery period |
| // when a packet is lost [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-7.3.1-3 |
| t.Logf("# loss of a packet triggers entry to a recovery period") |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{6, 7}) |
| test.wantAck(initialSpace, 6) |
| test.wantLoss(initialSpace, 3) |
| |
| // "On entering a recovery period, a sender MUST set the slow start |
| // threshold to half the value of the congestion window when loss is detected." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-7.3.2-2 |
| t.Logf("# slow_start_threshold = congestion_window / 2") |
| test.wantVar("slow_start_threshold", 7800) // 15600/2 |
| |
| // "[...] a single packet can be sent prior to reduction [of the congestion window]." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-7.3.2-3 |
| test.send(initialSpace, 10, testSentPacketSize(1200)) |
| |
| // "The congestion window MUST be set to the reduced value of the slow start |
| // threshold before exiting the recovery period." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-7.3.2-2 |
| t.Logf("# congestion window reduced to slow start threshold") |
| test.wantVar("congestion_window", 7800) |
| |
| t.Logf("# acks for packets sent before recovery started do not affect congestion") |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 10}) |
| test.wantAck(initialSpace, 4, 5, 7, 8, 9) |
| test.wantVar("slow_start_threshold", 7800) |
| test.wantVar("congestion_window", 7800) |
| |
| // "A recovery period ends and the sender enters congestion avoidance when |
| // a packet sent during the recovery period is acknowledged." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-7.3.2-5 |
| t.Logf("# recovery ends and congestion avoidance begins when packet 10 is acked") |
| test.advance(333 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 11}) |
| test.wantAck(initialSpace, 10) |
| |
| // "[...] limit the increase to the congestion window to at most one |
| // maximum datagram size for each congestion window that is acknowledged." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-7.3.3-2 |
| t.Logf("# after processing acks for one congestion window's worth of data...") |
| test.send(initialSpace, 11, 12, 13, 14, 15, 16, testSentPacketSize(1200)) |
| test.advance(333 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 17}) |
| test.wantAck(initialSpace, 11, 12, 13, 14, 15, 16) |
| t.Logf("# ...congestion window increases by max_datagram_size") |
| test.wantVar("congestion_window", 9000) // 7800 + 1200 |
| |
| // "The sender exits congestion avoidance and enters a recovery period |
| // when a packet is lost [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-7.3.3-3 |
| test.send(initialSpace, 17, 18, 19, 20, 21, testSentPacketSize(1200)) |
| test.advance(333 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{18, 21}) |
| test.wantAck(initialSpace, 18, 19, 20) |
| test.wantLoss(initialSpace, 17) |
| t.Logf("# slow_start_threshold = congestion_window / 2") |
| test.wantVar("slow_start_threshold", 4500) |
| } |
| |
| func TestLossMinimumCongestionWindow(t *testing.T) { |
| // "The RECOMMENDED [minimum congestion window] is 2 * max_datagram_size." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-7.2-4 |
| test := newLossTest(t, clientSide, lossTestOpts{ |
| maxDatagramSize: 1200, |
| }) |
| test.send(initialSpace, 0, 1, 2, 3, testSentPacketSize(1200)) |
| test.wantVar("congestion_window", 12000) |
| |
| t.Logf("# enter recovery") |
| test.advance(333 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{3, 4}) |
| test.wantAck(initialSpace, 3) |
| test.wantLoss(initialSpace, 0) |
| test.wantVar("congestion_window", 6000) |
| |
| t.Logf("# enter congestion avoidance and return to recovery") |
| test.send(initialSpace, 4, 5, 6, 7) |
| test.advance(333 * time.Millisecond) |
| test.wantLoss(initialSpace, 1, 2) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{7, 8}) |
| test.wantAck(initialSpace, 7) |
| test.wantLoss(initialSpace, 4) |
| test.wantVar("congestion_window", 3000) |
| |
| t.Logf("# enter congestion avoidance and return to recovery") |
| test.send(initialSpace, 8, 9, 10, 11) |
| test.advance(333 * time.Millisecond) |
| test.wantLoss(initialSpace, 5, 6) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{11, 12}) |
| test.wantAck(initialSpace, 11) |
| test.wantLoss(initialSpace, 8) |
| t.Logf("# congestion window does not fall below 2*max_datagram_size") |
| test.wantVar("congestion_window", 2400) |
| |
| t.Logf("# enter congestion avoidance and return to recovery") |
| test.send(initialSpace, 12, 13, 14, 15) |
| test.advance(333 * time.Millisecond) |
| test.wantLoss(initialSpace, 9, 10) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{15, 16}) |
| test.wantAck(initialSpace, 15) |
| test.wantLoss(initialSpace, 12) |
| t.Logf("# congestion window does not fall below 2*max_datagram_size") |
| test.wantVar("congestion_window", 2400) |
| } |
| |
| func TestLossPersistentCongestion(t *testing.T) { |
| // "When persistent congestion is declared, the sender's congestion |
| // window MUST be reduced to the minimum congestion window [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-7.6.2-6 |
| test := newLossTest(t, clientSide, lossTestOpts{ |
| maxDatagramSize: 1200, |
| }) |
| test.send(initialSpace, 0, testSentPacketSize(1200)) |
| test.c.cc.setUnderutilized(nil, true) |
| |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| |
| t.Logf("# set rttvar for simplicity") |
| test.setRTTVar(0) |
| test.wantVar("smoothed_rtt", 10*time.Millisecond) |
| t.Logf("# persistent congestion duration = 3*(smoothed_rtt + timerGranularity + max_ack_delay)") |
| t.Logf("# persistent congestion duration = 108ms") |
| |
| t.Logf("# sending packets 1-5 over 108ms") |
| test.send(initialSpace, 1, testSentPacketSize(1200)) |
| |
| test.advance(11 * time.Millisecond) // total 11ms |
| test.wantPTOExpired() |
| test.send(initialSpace, 2, testSentPacketSize(1200)) |
| |
| test.advance(22 * time.Millisecond) // total 33ms |
| test.wantPTOExpired() |
| test.send(initialSpace, 3, testSentPacketSize(1200)) |
| |
| test.advance(44 * time.Millisecond) // total 77ms |
| test.wantPTOExpired() |
| test.send(initialSpace, 4, testSentPacketSize(1200)) |
| |
| test.advance(31 * time.Millisecond) // total 108ms |
| test.send(initialSpace, 5, testSentPacketSize(1200)) |
| t.Logf("# 108ms between packets 1-5") |
| |
| test.wantVar("congestion_window", 12000) |
| t.Logf("# triggering loss of packets 1-5") |
| test.send(initialSpace, 6, 7, 8, testSentPacketSize(1200)) |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{8, 9}) |
| test.wantAck(initialSpace, 8) |
| test.wantLoss(initialSpace, 1, 2, 3, 4, 5) |
| |
| t.Logf("# lost packets spanning persistent congestion duration") |
| t.Logf("# congestion_window = 2 * max_datagram_size (minimum)") |
| test.wantVar("congestion_window", 2400) |
| } |
| |
| func TestLossSimplePersistentCongestion(t *testing.T) { |
| // Simpler version of TestLossPersistentCongestion which acts as a |
| // base for subsequent tests. |
| test := newLossTest(t, clientSide, lossTestOpts{ |
| maxDatagramSize: 1200, |
| }) |
| |
| t.Logf("# establish initial RTT sample") |
| test.send(initialSpace, 0, testSentPacketSize(1200)) |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| |
| t.Logf("# send two packets spanning persistent congestion duration") |
| test.send(initialSpace, 1, testSentPacketSize(1200)) |
| t.Logf("# 2000ms >> persistent congestion duration") |
| test.advance(2000 * time.Millisecond) |
| test.wantPTOExpired() |
| test.send(initialSpace, 2, testSentPacketSize(1200)) |
| |
| t.Logf("# trigger loss of previous packets") |
| test.advance(10 * time.Millisecond) |
| test.send(initialSpace, 3, testSentPacketSize(1200)) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{3, 4}) |
| test.wantAck(initialSpace, 3) |
| test.wantLoss(initialSpace, 1, 2) |
| |
| t.Logf("# persistent congestion detected") |
| test.wantVar("congestion_window", 2400) |
| } |
| |
| func TestLossPersistentCongestionAckElicitingPackets(t *testing.T) { |
| // "These two packets MUST be ack-eliciting [...]" |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-7.6.2-3 |
| test := newLossTest(t, clientSide, lossTestOpts{ |
| maxDatagramSize: 1200, |
| }) |
| |
| t.Logf("# establish initial RTT sample") |
| test.send(initialSpace, 0, testSentPacketSize(1200)) |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| |
| t.Logf("# send two packets spanning persistent congestion duration") |
| test.send(initialSpace, 1, testSentPacketSize(1200)) |
| t.Logf("# 2000ms >> persistent congestion duration") |
| test.advance(2000 * time.Millisecond) |
| test.wantPTOExpired() |
| test.send(initialSpace, 2, sentPacket{ |
| inFlight: true, |
| ackEliciting: false, |
| size: 1200, |
| }) |
| test.send(initialSpace, 3, testSentPacketSize(1200)) // PTO probe |
| |
| t.Logf("# trigger loss of previous packets") |
| test.advance(10 * time.Millisecond) |
| test.send(initialSpace, 4, testSentPacketSize(1200)) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{3, 5}) |
| test.wantAck(initialSpace, 3) |
| test.wantAck(initialSpace, 4) |
| test.wantLoss(initialSpace, 1, 2) |
| |
| t.Logf("# persistent congestion not detected: packet 2 is not ack-eliciting") |
| test.wantVar("congestion_window", (12000+1200+1200-1200)/2) |
| } |
| |
| func TestLossNoPersistentCongestionWithoutRTTSample(t *testing.T) { |
| // "The persistent congestion period SHOULD NOT start until there |
| // is at least one RTT sample." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-7.6.2-4 |
| test := newLossTest(t, clientSide, lossTestOpts{ |
| maxDatagramSize: 1200, |
| }) |
| |
| t.Logf("# packets sent before initial RTT sample") |
| test.send(initialSpace, 0, testSentPacketSize(1200)) |
| test.advance(2000 * time.Millisecond) |
| test.wantPTOExpired() |
| test.send(initialSpace, 1, testSentPacketSize(1200)) |
| |
| test.advance(10 * time.Millisecond) |
| test.send(initialSpace, 2, testSentPacketSize(1200)) |
| |
| t.Logf("# first ack establishes RTT sample") |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{2, 3}) |
| test.wantAck(initialSpace, 2) |
| test.wantLoss(initialSpace, 0, 1) |
| |
| t.Logf("# loss of packets before initial RTT sample does not cause persistent congestion") |
| test.wantVar("congestion_window", 12000/2) |
| } |
| |
| func TestLossPacerRefillRate(t *testing.T) { |
| // "A sender SHOULD pace sending of all in-flight packets based on |
| // input from the congestion controller." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-7.7-1 |
| test := newLossTest(t, clientSide, lossTestOpts{ |
| maxDatagramSize: 1200, |
| }) |
| t.Logf("# consume the initial congestion window") |
| test.send(initialSpace, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, testSentPacketSize(1200)) |
| test.wantSendLimit(ccLimited) |
| test.wantVar("pacer_bucket", 0) |
| test.wantVar("congestion_window", 12000) |
| |
| t.Logf("# first RTT sample establishes smoothed_rtt") |
| rtt := 100 * time.Millisecond |
| test.advance(rtt) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 10}) |
| test.wantAck(initialSpace, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9) |
| test.wantVar("congestion_window", 24000) // 12000 + 10*1200 |
| test.wantVar("smoothed_rtt", rtt) |
| |
| t.Logf("# advance 1 RTT to let the pacer bucket refill completely") |
| test.advance(100 * time.Millisecond) |
| t.Logf("# pacer_bucket = initial_congestion_window") |
| test.wantVar("pacer_bucket", 12000) |
| |
| t.Logf("# consume capacity from the pacer bucket") |
| test.send(initialSpace, 10, testSentPacketSize(1200)) |
| test.wantVar("pacer_bucket", 10800) // 12000 - 1200 |
| test.send(initialSpace, 11, testSentPacketSize(600)) |
| test.wantVar("pacer_bucket", 10200) // 10800 - 600 |
| test.send(initialSpace, 12, testSentPacketSize(600)) |
| test.wantVar("pacer_bucket", 9600) // 10200 - 600 |
| test.send(initialSpace, 13, 14, 15, 16, testSentPacketSize(1200)) |
| test.wantVar("pacer_bucket", 4800) // 9600 - 4*1200 |
| |
| t.Logf("# advance 1/10 of an RTT, bucket refills") |
| test.advance(rtt / 10) |
| t.Logf("# pacer_bucket += 1.25 * (1/10) * congestion_window") |
| t.Logf("# += 3000") |
| test.wantVar("pacer_bucket", 7800) |
| } |
| |
| func TestLossPacerNextSendTime(t *testing.T) { |
| test := newLossTest(t, clientSide, lossTestOpts{ |
| maxDatagramSize: 1200, |
| }) |
| t.Logf("# consume the initial congestion window") |
| test.send(initialSpace, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, testSentPacketSize(1200)) |
| test.wantSendLimit(ccLimited) |
| test.wantVar("pacer_bucket", 0) |
| test.wantVar("congestion_window", 12000) |
| |
| t.Logf("# first RTT sample establishes smoothed_rtt") |
| rtt := 100 * time.Millisecond |
| test.advance(rtt) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 10}) |
| test.wantAck(initialSpace, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9) |
| test.wantVar("congestion_window", 24000) // 12000 + 10*1200 |
| test.wantVar("smoothed_rtt", rtt) |
| |
| t.Logf("# advance 1 RTT to let the pacer bucket refill completely") |
| test.advance(100 * time.Millisecond) |
| t.Logf("# pacer_bucket = initial_congestion_window") |
| test.wantVar("pacer_bucket", 12000) |
| |
| t.Logf("# consume the refilled pacer bucket") |
| test.send(initialSpace, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, testSentPacketSize(1200)) |
| test.wantSendLimit(ccPaced) |
| |
| t.Logf("# refill rate = 1.25 * congestion_window / rtt") |
| test.wantSendDelay(rtt / 25) // rtt / (1.25 * 24000 / 1200) |
| |
| t.Logf("# no capacity available yet") |
| test.advance(rtt / 50) |
| test.wantVar("pacer_bucket", -600) |
| test.wantSendLimit(ccPaced) |
| |
| t.Logf("# capacity available") |
| test.advance(rtt / 50) |
| test.wantVar("pacer_bucket", 0) |
| test.wantSendLimit(ccOK) |
| } |
| |
| func TestLossCongestionWindowUnderutilized(t *testing.T) { |
| // "When bytes in flight is smaller than the congestion window |
| // and sending is not pacing limited [...] the congestion window |
| // SHOULD NOT be increased in either slow start or congestion avoidance." |
| // https://www.rfc-editor.org/rfc/rfc9002.html#section-7.8-1 |
| test := newLossTest(t, clientSide, lossTestOpts{ |
| maxDatagramSize: 1200, |
| }) |
| test.send(initialSpace, 0, testSentPacketSize(1200)) |
| test.setUnderutilized(true) |
| t.Logf("# underutilized: %v", test.c.cc.underutilized) |
| test.wantVar("congestion_window", 12000) |
| |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 1}) |
| test.wantAck(initialSpace, 0) |
| t.Logf("# congestion window does not increase, because window is underutilized") |
| test.wantVar("congestion_window", 12000) |
| |
| t.Logf("# refill pacer bucket") |
| test.advance(10 * time.Millisecond) |
| test.wantVar("pacer_bucket", 12000) |
| |
| test.send(initialSpace, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, testSentPacketSize(1200)) |
| test.setUnderutilized(false) |
| test.advance(10 * time.Millisecond) |
| test.ack(initialSpace, 0*time.Millisecond, i64range[packetNumber]{0, 11}) |
| test.wantAck(initialSpace, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10) |
| t.Logf("# congestion window increases") |
| test.wantVar("congestion_window", 24000) |
| } |
| |
| type lossTest struct { |
| t *testing.T |
| c lossState |
| now time.Time |
| fates map[spaceNum]packetFate |
| failed bool |
| } |
| |
| type lossTestOpts struct { |
| maxDatagramSize int |
| } |
| |
| func newLossTest(t *testing.T, side connSide, opts lossTestOpts) *lossTest { |
| c := &lossTest{ |
| t: t, |
| now: time.Date(2000, 1, 1, 0, 0, 0, 0, time.UTC), |
| fates: make(map[spaceNum]packetFate), |
| } |
| maxDatagramSize := 1200 |
| if opts.maxDatagramSize != 0 { |
| maxDatagramSize = opts.maxDatagramSize |
| } |
| c.c.init(side, maxDatagramSize, c.now) |
| t.Cleanup(func() { |
| if !c.failed { |
| c.checkUnexpectedEvents() |
| } |
| }) |
| return c |
| } |
| |
| type spaceNum struct { |
| space numberSpace |
| num packetNumber |
| } |
| |
| func (c *lossTest) checkUnexpectedEvents() { |
| c.t.Helper() |
| for sn, fate := range c.fates { |
| c.t.Errorf("ERROR: unexpected %v: %v %v", fate, sn.space, sn.num) |
| } |
| if c.c.ptoExpired { |
| c.t.Errorf("ERROR: PTO timer unexpectedly expired") |
| } |
| } |
| |
| func (c *lossTest) setSmoothedRTT(d time.Duration) { |
| c.t.Helper() |
| c.checkUnexpectedEvents() |
| c.t.Logf("set smoothed_rtt to %v", d) |
| c.c.rtt.smoothedRTT = d |
| } |
| |
| func (c *lossTest) setRTTVar(d time.Duration) { |
| c.t.Helper() |
| c.checkUnexpectedEvents() |
| c.t.Logf("set rttvar to %v", d) |
| c.c.rtt.rttvar = d |
| } |
| |
| func (c *lossTest) setUnderutilized(v bool) { |
| c.t.Logf("set congestion window underutilized: %v", v) |
| c.c.cc.setUnderutilized(nil, v) |
| } |
| |
| func (c *lossTest) advance(d time.Duration) { |
| c.t.Helper() |
| c.checkUnexpectedEvents() |
| c.t.Logf("advance time %v", d) |
| c.now = c.now.Add(d) |
| c.c.advance(c.now, c.onAckOrLoss) |
| } |
| |
| func (c *lossTest) advanceToLossTimer() { |
| c.t.Helper() |
| c.checkUnexpectedEvents() |
| d := c.c.timer.Sub(c.now) |
| c.t.Logf("advance time %v (up to loss timer)", d) |
| if d < 0 { |
| c.t.Fatalf("loss timer is in the past") |
| } |
| c.now = c.c.timer |
| c.c.advance(c.now, c.onAckOrLoss) |
| } |
| |
| type testSentPacketSize int |
| |
| func (c *lossTest) send(spaceID numberSpace, opts ...any) { |
| c.t.Helper() |
| c.checkUnexpectedEvents() |
| var nums []packetNumber |
| prototype := sentPacket{ |
| ackEliciting: true, |
| inFlight: true, |
| } |
| for _, o := range opts { |
| switch o := o.(type) { |
| case sentPacket: |
| prototype = o |
| case testSentPacketSize: |
| prototype.size = int(o) |
| case int: |
| nums = append(nums, packetNumber(o)) |
| case packetNumber: |
| nums = append(nums, o) |
| case i64range[packetNumber]: |
| for num := o.start; num < o.end; num++ { |
| nums = append(nums, num) |
| } |
| } |
| } |
| c.t.Logf("send %v %v", spaceID, nums) |
| limit, _ := c.c.sendLimit(c.now) |
| if prototype.inFlight && limit != ccOK { |
| c.t.Fatalf("congestion control blocks sending packet") |
| } |
| if !prototype.inFlight && limit == ccBlocked { |
| c.t.Fatalf("congestion control blocks sending packet") |
| } |
| for _, num := range nums { |
| sent := &sentPacket{} |
| *sent = prototype |
| sent.num = num |
| c.c.packetSent(c.now, nil, spaceID, sent) |
| } |
| } |
| |
| func (c *lossTest) datagramReceived(size int) { |
| c.t.Helper() |
| c.checkUnexpectedEvents() |
| c.t.Logf("receive %v-byte datagram", size) |
| c.c.datagramReceived(c.now, size) |
| } |
| |
| func (c *lossTest) ack(spaceID numberSpace, ackDelay time.Duration, rs ...i64range[packetNumber]) { |
| c.t.Helper() |
| c.checkUnexpectedEvents() |
| c.c.receiveAckStart() |
| var acked rangeset[packetNumber] |
| for _, r := range rs { |
| c.t.Logf("ack %v delay=%v [%v,%v)", spaceID, ackDelay, r.start, r.end) |
| acked.add(r.start, r.end) |
| } |
| for i, r := range rs { |
| c.t.Logf("ack %v delay=%v [%v,%v)", spaceID, ackDelay, r.start, r.end) |
| c.c.receiveAckRange(c.now, spaceID, i, r.start, r.end, c.onAckOrLoss) |
| } |
| c.c.receiveAckEnd(c.now, nil, spaceID, ackDelay, c.onAckOrLoss) |
| } |
| |
| func (c *lossTest) onAckOrLoss(space numberSpace, sent *sentPacket, fate packetFate) { |
| c.t.Logf("%v %v %v", fate, space, sent.num) |
| if _, ok := c.fates[spaceNum{space, sent.num}]; ok { |
| c.t.Errorf("ERROR: duplicate %v for %v %v", fate, space, sent.num) |
| } |
| c.fates[spaceNum{space, sent.num}] = fate |
| } |
| |
| func (c *lossTest) confirmHandshake() { |
| c.t.Helper() |
| c.checkUnexpectedEvents() |
| c.t.Logf("confirm handshake") |
| c.c.confirmHandshake() |
| } |
| |
| func (c *lossTest) validateClientAddress() { |
| c.t.Helper() |
| c.checkUnexpectedEvents() |
| c.t.Logf("validate client address") |
| c.c.validateClientAddress() |
| } |
| |
| func (c *lossTest) discardKeys(spaceID numberSpace) { |
| c.t.Helper() |
| c.checkUnexpectedEvents() |
| c.t.Logf("discard %s keys", spaceID) |
| c.c.discardKeys(c.now, nil, spaceID) |
| } |
| |
| func (c *lossTest) setMaxAckDelay(d time.Duration) { |
| c.t.Helper() |
| c.checkUnexpectedEvents() |
| c.t.Logf("set max_ack_delay = %v", d) |
| c.c.setMaxAckDelay(d) |
| } |
| |
| func (c *lossTest) wantAck(spaceID numberSpace, nums ...packetNumber) { |
| c.t.Helper() |
| for _, num := range nums { |
| if c.fates[spaceNum{spaceID, num}] != packetAcked { |
| c.t.Fatalf("expected ack for %v %v\n", spaceID, num) |
| } |
| delete(c.fates, spaceNum{spaceID, num}) |
| } |
| } |
| |
| func (c *lossTest) wantLoss(spaceID numberSpace, nums ...packetNumber) { |
| c.t.Helper() |
| for _, num := range nums { |
| if c.fates[spaceNum{spaceID, num}] != packetLost { |
| c.t.Fatalf("expected loss of %v %v\n", spaceID, num) |
| } |
| delete(c.fates, spaceNum{spaceID, num}) |
| } |
| } |
| |
| func (c *lossTest) wantPTOExpired() { |
| c.t.Helper() |
| if !c.c.ptoExpired { |
| c.t.Fatalf("expected PTO timer to expire") |
| } else { |
| c.t.Logf("PTO TIMER EXPIRED") |
| } |
| c.c.ptoExpired = false |
| } |
| |
| func (l ccLimit) String() string { |
| switch l { |
| case ccOK: |
| return "ccOK" |
| case ccBlocked: |
| return "ccBlocked" |
| case ccLimited: |
| return "ccLimited" |
| case ccPaced: |
| return "ccPaced" |
| } |
| return "BUG" |
| } |
| |
| func (c *lossTest) wantSendLimit(want ccLimit) { |
| c.t.Helper() |
| if got, _ := c.c.sendLimit(c.now); got != want { |
| c.t.Fatalf("congestion control send limit is %v, want %v", got, want) |
| } |
| } |
| |
| func (c *lossTest) wantSendDelay(want time.Duration) { |
| c.t.Helper() |
| limit, next := c.c.sendLimit(c.now) |
| if limit != ccPaced { |
| c.t.Fatalf("congestion control limit is %v, want %v", limit, ccPaced) |
| } |
| got := next.Sub(c.now) |
| if got != want { |
| c.t.Fatalf("delay until next send is %v, want %v", got, want) |
| } |
| } |
| |
| func (c *lossTest) wantVar(name string, want any) { |
| c.t.Helper() |
| var got any |
| switch name { |
| case "latest_rtt": |
| got = c.c.rtt.latestRTT |
| case "min_rtt": |
| got = c.c.rtt.minRTT |
| case "smoothed_rtt": |
| got = c.c.rtt.smoothedRTT |
| case "rttvar": |
| got = c.c.rtt.rttvar |
| case "congestion_window": |
| got = c.c.cc.congestionWindow |
| case "slow_start_threshold": |
| got = c.c.cc.slowStartThreshold |
| case "bytes_in_flight": |
| got = c.c.cc.bytesInFlight |
| case "pacer_bucket": |
| got = c.c.pacer.bucket |
| default: |
| c.t.Fatalf("unknown var %q", name) |
| } |
| if got != want { |
| c.t.Fatalf("%v = %v, want %v\n", name, got, want) |
| } else { |
| c.t.Logf("%v = %v", name, got) |
| } |
| } |
| |
| func (c *lossTest) wantTimeout(want time.Duration) { |
| c.t.Helper() |
| if c.c.timer.IsZero() { |
| c.t.Fatalf("loss detection timer is not set, want %v", want) |
| } |
| got := c.c.timer.Sub(c.now) |
| if got != want { |
| c.t.Fatalf("loss detection timer expires in %v, want %v", got, want) |
| } |
| c.t.Logf("loss detection timer expires in %v", got) |
| } |
| |
| func (c *lossTest) wantNoTimeout() { |
| c.t.Helper() |
| if !c.c.timer.IsZero() { |
| d := c.c.timer.Sub(c.now) |
| c.t.Fatalf("loss detection timer expires in %v, want not set", d) |
| } |
| c.t.Logf("loss detection timer is not set") |
| } |
| |
| func (f packetFate) String() string { |
| switch f { |
| case packetAcked: |
| return "ACK" |
| case packetLost: |
| return "LOSS" |
| default: |
| panic("unknown packetFate") |
| } |
| } |
