diff options
Diffstat (limited to 'pkg/tcpip/transport/tcp')
| -rw-r--r-- | pkg/tcpip/transport/tcp/connect.go | 11 | ||||
| -rw-r--r-- | pkg/tcpip/transport/tcp/endpoint.go | 29 |
2 files changed, 27 insertions, 13 deletions
diff --git a/pkg/tcpip/transport/tcp/connect.go b/pkg/tcpip/transport/tcp/connect.go index cd247f3e1..ae4f3f3a9 100644 --- a/pkg/tcpip/transport/tcp/connect.go +++ b/pkg/tcpip/transport/tcp/connect.go @@ -295,6 +295,7 @@ func (h *handshake) synSentState(s *segment) *tcpip.Error { h.state = handshakeSynRcvd h.ep.mu.Lock() ttl := h.ep.ttl + amss := h.ep.amss h.ep.setEndpointState(StateSynRecv) h.ep.mu.Unlock() synOpts := header.TCPSynOptions{ @@ -307,7 +308,7 @@ func (h *handshake) synSentState(s *segment) *tcpip.Error { // permits SACK. This is not explicitly defined in the RFC but // this is the behaviour implemented by Linux. SACKPermitted: rcvSynOpts.SACKPermitted, - MSS: h.ep.amss, + MSS: amss, } if ttl == 0 { ttl = s.route.DefaultTTL() @@ -356,6 +357,10 @@ func (h *handshake) synRcvdState(s *segment) *tcpip.Error { return tcpip.ErrInvalidEndpointState } + h.ep.mu.RLock() + amss := h.ep.amss + h.ep.mu.RUnlock() + h.resetState() synOpts := header.TCPSynOptions{ WS: h.rcvWndScale, @@ -363,7 +368,7 @@ func (h *handshake) synRcvdState(s *segment) *tcpip.Error { TSVal: h.ep.timestamp(), TSEcr: h.ep.recentTimestamp(), SACKPermitted: h.ep.sackPermitted, - MSS: h.ep.amss, + MSS: amss, } h.ep.sendSynTCP(&s.route, h.ep.ID, h.ep.ttl, h.ep.sendTOS, h.flags, h.iss, h.ackNum, h.rcvWnd, synOpts) return nil @@ -530,6 +535,7 @@ func (h *handshake) execute() *tcpip.Error { // Send the initial SYN segment and loop until the handshake is // completed. + h.ep.mu.Lock() h.ep.amss = calculateAdvertisedMSS(h.ep.userMSS, h.ep.route) synOpts := header.TCPSynOptions{ @@ -540,6 +546,7 @@ func (h *handshake) execute() *tcpip.Error { SACKPermitted: bool(sackEnabled), MSS: h.ep.amss, } + h.ep.mu.Unlock() // Execute is also called in a listen context so we want to make sure we // only send the TS/SACK option when we received the TS/SACK in the diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go index 9e72730bd..8b9154e69 100644 --- a/pkg/tcpip/transport/tcp/endpoint.go +++ b/pkg/tcpip/transport/tcp/endpoint.go @@ -959,15 +959,18 @@ func (e *endpoint) initialReceiveWindow() int { // ModerateRecvBuf adjusts the receive buffer and the advertised window // based on the number of bytes copied to user space. func (e *endpoint) ModerateRecvBuf(copied int) { + e.mu.RLock() e.rcvListMu.Lock() if e.rcvAutoParams.disabled { e.rcvListMu.Unlock() + e.mu.RUnlock() return } now := time.Now() if rtt := e.rcvAutoParams.rtt; rtt == 0 || now.Sub(e.rcvAutoParams.measureTime) < rtt { e.rcvAutoParams.copied += copied e.rcvListMu.Unlock() + e.mu.RUnlock() return } prevRTTCopied := e.rcvAutoParams.copied + copied @@ -1008,7 +1011,7 @@ func (e *endpoint) ModerateRecvBuf(copied int) { e.rcvBufSize = rcvWnd availAfter := e.receiveBufferAvailableLocked() mask := uint32(notifyReceiveWindowChanged) - if crossed, above := e.windowCrossedACKThreshold(availAfter - availBefore); crossed && above { + if crossed, above := e.windowCrossedACKThresholdLocked(availAfter - availBefore); crossed && above { mask |= notifyNonZeroReceiveWindow } e.notifyProtocolGoroutine(mask) @@ -1023,6 +1026,7 @@ func (e *endpoint) ModerateRecvBuf(copied int) { e.rcvAutoParams.measureTime = now e.rcvAutoParams.copied = 0 e.rcvListMu.Unlock() + e.mu.RUnlock() } // IPTables implements tcpip.Endpoint.IPTables. @@ -1052,7 +1056,6 @@ func (e *endpoint) Read(*tcpip.FullAddress) (buffer.View, tcpip.ControlMessages, v, err := e.readLocked() e.rcvListMu.Unlock() - e.mu.RUnlock() if err == tcpip.ErrClosedForReceive { @@ -1085,7 +1088,7 @@ func (e *endpoint) readLocked() (buffer.View, *tcpip.Error) { // enough buffer space, to either fit an aMSS or half a receive buffer // (whichever smaller), then notify the protocol goroutine to send a // window update. - if crossed, above := e.windowCrossedACKThreshold(len(v)); crossed && above { + if crossed, above := e.windowCrossedACKThresholdLocked(len(v)); crossed && above { e.notifyProtocolGoroutine(notifyNonZeroReceiveWindow) } @@ -1303,9 +1306,9 @@ func (e *endpoint) Peek(vec [][]byte) (int64, tcpip.ControlMessages, *tcpip.Erro return num, tcpip.ControlMessages{}, nil } -// windowCrossedACKThreshold checks if the receive window to be announced now -// would be under aMSS or under half receive buffer, whichever smaller. This is -// useful as a receive side silly window syndrome prevention mechanism. If +// windowCrossedACKThresholdLocked checks if the receive window to be announced +// now would be under aMSS or under half receive buffer, whichever smaller. This +// is useful as a receive side silly window syndrome prevention mechanism. If // window grows to reasonable value, we should send ACK to the sender to inform // the rx space is now large. We also want ensure a series of small read()'s // won't trigger a flood of spurious tiny ACK's. @@ -1316,7 +1319,9 @@ func (e *endpoint) Peek(vec [][]byte) (int64, tcpip.ControlMessages, *tcpip.Erro // crossed will be true if the window size crossed the ACK threshold. // above will be true if the new window is >= ACK threshold and false // otherwise. -func (e *endpoint) windowCrossedACKThreshold(deltaBefore int) (crossed bool, above bool) { +// +// Precondition: e.mu and e.rcvListMu must be held. +func (e *endpoint) windowCrossedACKThresholdLocked(deltaBefore int) (crossed bool, above bool) { newAvail := e.receiveBufferAvailableLocked() oldAvail := newAvail - deltaBefore if oldAvail < 0 { @@ -1379,6 +1384,7 @@ func (e *endpoint) SetSockOptInt(opt tcpip.SockOptInt, v int) *tcpip.Error { mask := uint32(notifyReceiveWindowChanged) + e.mu.RLock() e.rcvListMu.Lock() // Make sure the receive buffer size allows us to send a @@ -1405,11 +1411,11 @@ func (e *endpoint) SetSockOptInt(opt tcpip.SockOptInt, v int) *tcpip.Error { // Immediately send an ACK to uncork the sender silly window // syndrome prevetion, when our available space grows above aMSS // or half receive buffer, whichever smaller. - if crossed, above := e.windowCrossedACKThreshold(availAfter - availBefore); crossed && above { + if crossed, above := e.windowCrossedACKThresholdLocked(availAfter - availBefore); crossed && above { mask |= notifyNonZeroReceiveWindow } e.rcvListMu.Unlock() - + e.mu.RUnlock() e.notifyProtocolGoroutine(mask) return nil @@ -2414,13 +2420,14 @@ func (e *endpoint) updateSndBufferUsage(v int) { // to be read, or when the connection is closed for receiving (in which case // s will be nil). func (e *endpoint) readyToRead(s *segment) { + e.mu.RLock() e.rcvListMu.Lock() if s != nil { s.incRef() e.rcvBufUsed += s.data.Size() // Increase counter if the receive window falls down below MSS // or half receive buffer size, whichever smaller. - if crossed, above := e.windowCrossedACKThreshold(-s.data.Size()); crossed && !above { + if crossed, above := e.windowCrossedACKThresholdLocked(-s.data.Size()); crossed && !above { e.stats.ReceiveErrors.ZeroRcvWindowState.Increment() } e.rcvList.PushBack(s) @@ -2428,7 +2435,7 @@ func (e *endpoint) readyToRead(s *segment) { e.rcvClosed = true } e.rcvListMu.Unlock() - + e.mu.RUnlock() e.waiterQueue.Notify(waiter.EventIn) } |