diff options
Diffstat (limited to 'pkg/tcpip/transport/tcp/snd.go')
| -rw-r--r-- | pkg/tcpip/transport/tcp/snd.go | 52 |
1 files changed, 44 insertions, 8 deletions
diff --git a/pkg/tcpip/transport/tcp/snd.go b/pkg/tcpip/transport/tcp/snd.go index 063a7086a..d6365b93d 100644 --- a/pkg/tcpip/transport/tcp/snd.go +++ b/pkg/tcpip/transport/tcp/snd.go @@ -191,6 +191,15 @@ type sender struct { // rc has the fields needed for implementing RACK loss detection // algorithm. rc rackControl + + // reorderTimer is the timer used to retransmit the segments after RACK + // detects them as lost. + reorderTimer timer `state:"nosave"` + reorderWaker sleep.Waker `state:"nosave"` + + // probeTimer and probeWaker are used to schedule PTO for RACK TLP algorithm. + probeTimer timer `state:"nosave"` + probeWaker sleep.Waker `state:"nosave"` } // rtt is a synchronization wrapper used to appease stateify. See the comment @@ -267,7 +276,6 @@ func newSender(ep *endpoint, iss, irs seqnum.Value, sndWnd seqnum.Size, mss uint } s.cc = s.initCongestionControl(ep.cc) - s.lr = s.initLossRecovery() s.rc.init(s, iss) @@ -278,6 +286,8 @@ func newSender(ep *endpoint, iss, irs seqnum.Value, sndWnd seqnum.Size, mss uint } s.resendTimer.init(&s.resendWaker) + s.reorderTimer.init(&s.reorderWaker) + s.probeTimer.init(&s.probeWaker) s.updateMaxPayloadSize(int(ep.route.MTU()), 0) @@ -1126,6 +1136,15 @@ func (s *sender) SetPipe() { func (s *sender) detectLoss(seg *segment) (fastRetransmit bool) { // We're not in fast recovery yet. + // If RACK is enabled and there is no reordering we should honor the + // three duplicate ACK rule to enter recovery. + // See: https://tools.ietf.org/html/draft-ietf-tcpm-rack-08#section-4 + if s.ep.sackPermitted && s.ep.tcpRecovery&tcpip.TCPRACKLossDetection != 0 { + if s.rc.reorderSeen { + return false + } + } + if !s.isDupAck(seg) { s.dupAckCount = 0 return false @@ -1462,6 +1481,7 @@ func (s *sender) handleRcvdSegment(rcvdSeg *segment) { if s.ep.tcpRecovery&tcpip.TCPRACKLossDetection != 0 { s.rc.exitRecovery() } + s.reorderTimer.disable() } } @@ -1481,21 +1501,36 @@ func (s *sender) handleRcvdSegment(rcvdSeg *segment) { // Reset firstRetransmittedSegXmitTime to the zero value. s.firstRetransmittedSegXmitTime = time.Time{} s.resendTimer.disable() - s.rc.probeTimer.disable() + s.probeTimer.disable() } } - // Update RACK reorder window. - // See: https://tools.ietf.org/html/draft-ietf-tcpm-rack-08#section-7.2 - // * Upon receiving an ACK: - // * Step 4: Update RACK reordering window - if s.ep.tcpRecovery&tcpip.TCPRACKLossDetection != 0 { + if s.ep.sackPermitted && s.ep.tcpRecovery&tcpip.TCPRACKLossDetection != 0 { + // Update RACK reorder window. + // See: https://tools.ietf.org/html/draft-ietf-tcpm-rack-08#section-7.2 + // * Upon receiving an ACK: + // * Step 4: Update RACK reordering window s.rc.updateRACKReorderWindow(rcvdSeg) + + // After the reorder window is calculated, detect any loss by checking + // if the time elapsed after the segments are sent is greater than the + // reorder window. + if numLost := s.rc.detectLoss(rcvdSeg.rcvdTime); numLost > 0 && !s.fr.active { + // If any segment is marked as lost by + // RACK, enter recovery and retransmit + // the lost segments. + s.cc.HandleLossDetected() + s.enterRecovery() + } + + if s.fr.active { + s.rc.DoRecovery(nil, true) + } } // Now that we've popped all acknowledged data from the retransmit // queue, retransmit if needed. - if s.fr.active { + if s.fr.active && s.ep.tcpRecovery&tcpip.TCPRACKLossDetection == 0 { s.lr.DoRecovery(rcvdSeg, fastRetransmit) // When SACK is enabled data sending is governed by steps in // RFC 6675 Section 5 recovery steps A-C. @@ -1523,6 +1558,7 @@ func (s *sender) sendSegment(seg *segment) tcpip.Error { } seg.xmitTime = time.Now() seg.xmitCount++ + seg.lost = false err := s.sendSegmentFromView(seg.data, seg.flags, seg.sequenceNumber) // Every time a packet containing data is sent (including a |