diff options
Diffstat (limited to 'pkg/tcpip/transport/tcp/connect.go')
| -rw-r--r-- | pkg/tcpip/transport/tcp/connect.go | 67 |
1 files changed, 44 insertions, 23 deletions
diff --git a/pkg/tcpip/transport/tcp/connect.go b/pkg/tcpip/transport/tcp/connect.go index a80cbd52c..f85775a48 100644 --- a/pkg/tcpip/transport/tcp/connect.go +++ b/pkg/tcpip/transport/tcp/connect.go @@ -105,6 +105,11 @@ type handshake struct { // sendSYNOpts is the cached values for the SYN options to be sent. sendSYNOpts header.TCPSynOptions + + // sampleRTTWithTSOnly is true when the segment was retransmitted or we can't + // tell; then RTT can only be sampled when the incoming segment has timestamp + // options enabled. + sampleRTTWithTSOnly bool } func (e *endpoint) newHandshake() *handshake { @@ -268,8 +273,7 @@ func (h *handshake) synSentState(s *segment) tcpip.Error { // and the handshake is completed. if s.flags.Contains(header.TCPFlagAck) { h.state = handshakeCompleted - - h.ep.transitionToStateEstablishedLocked(h) + h.transitionToStateEstablishedLocked(s) h.ep.sendRaw(buffer.VectorisedView{}, header.TCPFlagAck, h.iss+1, h.ackNum, h.rcvWnd>>h.effectiveRcvWndScale()) return nil @@ -404,9 +408,10 @@ func (h *handshake) synRcvdState(s *segment) tcpip.Error { if h.ep.SendTSOk && s.parsedOptions.TS { h.ep.updateRecentTimestamp(s.parsedOptions.TSVal, h.ackNum, s.sequenceNumber) } + h.state = handshakeCompleted - h.ep.transitionToStateEstablishedLocked(h) + h.transitionToStateEstablishedLocked(s) // Requeue the segment if the ACK completing the handshake has more info // to be procesed by the newly established endpoint. @@ -559,6 +564,10 @@ func (h *handshake) complete() tcpip.Error { ack: h.ackNum, rcvWnd: h.rcvWnd, }, h.sendSYNOpts) + // If we have ever retransmitted the SYN-ACK or + // SYN segment, we should only measure RTT if + // TS option is present. + h.sampleRTTWithTSOnly = true } case wakerForNotification: @@ -602,6 +611,38 @@ func (h *handshake) complete() tcpip.Error { return nil } +// transitionToStateEstablisedLocked transitions the endpoint of the handshake +// to an established state given the last segment received from peer. It also +// initializes sender/receiver. +func (h *handshake) transitionToStateEstablishedLocked(s *segment) { + // Transfer handshake state to TCP connection. We disable + // receive window scaling if the peer doesn't support it + // (indicated by a negative send window scale). + h.ep.snd = newSender(h.ep, h.iss, h.ackNum-1, h.sndWnd, h.mss, h.sndWndScale) + + var rtt time.Duration + if h.ep.SendTSOk && s.parsedOptions.TSEcr != 0 { + rtt = time.Duration(h.ep.timestamp()-s.parsedOptions.TSEcr) * time.Millisecond + } + if !h.sampleRTTWithTSOnly && rtt == 0 { + rtt = h.ep.stack.Clock().NowMonotonic().Sub(h.startTime) + } + + if rtt > 0 { + h.ep.snd.updateRTO(rtt) + } + + h.ep.rcvQueueInfo.rcvQueueMu.Lock() + h.ep.rcv = newReceiver(h.ep, h.ackNum-1, h.rcvWnd, h.effectiveRcvWndScale()) + // Bootstrap the auto tuning algorithm. Starting at zero will + // result in a really large receive window after the first auto + // tuning adjustment. + h.ep.rcvQueueInfo.RcvAutoParams.PrevCopiedBytes = int(h.rcvWnd) + h.ep.rcvQueueInfo.rcvQueueMu.Unlock() + + h.ep.setEndpointState(StateEstablished) +} + type backoffTimer struct { timeout time.Duration maxTimeout time.Duration @@ -967,26 +1008,6 @@ func (e *endpoint) completeWorkerLocked() { } } -// transitionToStateEstablisedLocked transitions a given endpoint -// to an established state using the handshake parameters provided. -// It also initializes sender/receiver. -func (e *endpoint) transitionToStateEstablishedLocked(h *handshake) { - // Transfer handshake state to TCP connection. We disable - // receive window scaling if the peer doesn't support it - // (indicated by a negative send window scale). - e.snd = newSender(e, h.iss, h.ackNum-1, h.sndWnd, h.mss, h.sndWndScale) - - e.rcvQueueInfo.rcvQueueMu.Lock() - e.rcv = newReceiver(e, h.ackNum-1, h.rcvWnd, h.effectiveRcvWndScale()) - // Bootstrap the auto tuning algorithm. Starting at zero will - // result in a really large receive window after the first auto - // tuning adjustment. - e.rcvQueueInfo.RcvAutoParams.PrevCopiedBytes = int(h.rcvWnd) - e.rcvQueueInfo.rcvQueueMu.Unlock() - - e.setEndpointState(StateEstablished) -} - // transitionToStateCloseLocked ensures that the endpoint is // cleaned up from the transport demuxer, "before" moving to // StateClose. This will ensure that no packet will be |