diff options
| -rw-r--r-- | pkg/tcpip/transport/tcp/endpoint.go | 50 | ||||
| -rw-r--r-- | test/syscalls/BUILD | 2 |
2 files changed, 35 insertions, 17 deletions
diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go index 1aa1f12b4..ee60ebf58 100644 --- a/pkg/tcpip/transport/tcp/endpoint.go +++ b/pkg/tcpip/transport/tcp/endpoint.go @@ -207,6 +207,12 @@ type endpoint struct { rcvBufSize int rcvBufUsed int rcvAutoParams rcvBufAutoTuneParams + // zeroWindow indicates that the window was closed due to receive buffer + // space being filled up. This is set by the worker goroutine before + // moving a segment to the rcvList. This setting is cleared by the + // endpoint when a Read() call reads enough data for the new window to + // be non-zero. + zeroWindow bool // The following fields are protected by the mutex. mu sync.RWMutex `state:"nosave"` @@ -719,10 +725,12 @@ func (e *endpoint) readLocked() (buffer.View, *tcpip.Error) { s.decRef() } - scale := e.rcv.rcvWndScale - wasZero := e.zeroReceiveWindow(scale) e.rcvBufUsed -= len(v) - if wasZero && !e.zeroReceiveWindow(scale) { + // If the window was zero before this read and if the read freed up + // enough buffer space for the scaled window to be non-zero then notify + // the protocol goroutine to send a window update. + if e.zeroWindow && !e.zeroReceiveWindow(e.rcv.rcvWndScale) { + e.zeroWindow = false e.notifyProtocolGoroutine(notifyNonZeroReceiveWindow) } @@ -942,10 +950,10 @@ func (e *endpoint) SetSockOpt(opt interface{}) *tcpip.Error { size = math.MaxInt32 / 2 } - wasZero := e.zeroReceiveWindow(scale) e.rcvBufSize = size e.rcvAutoParams.disabled = true - if wasZero && !e.zeroReceiveWindow(scale) { + if e.zeroWindow && !e.zeroReceiveWindow(scale) { + e.zeroWindow = false mask |= notifyNonZeroReceiveWindow } e.rcvListMu.Unlock() @@ -1747,6 +1755,13 @@ func (e *endpoint) readyToRead(s *segment) { if s != nil { s.incRef() e.rcvBufUsed += s.data.Size() + // Check if the receive window is now closed. If so make sure + // we set the zero window before we deliver the segment to ensure + // that a subsequent read of the segment will correctly trigger + // a non-zero notification. + if avail := e.receiveBufferAvailableLocked(); avail>>e.rcv.rcvWndScale == 0 { + e.zeroWindow = true + } e.rcvList.PushBack(s) } else { e.rcvClosed = true @@ -1756,21 +1771,26 @@ func (e *endpoint) readyToRead(s *segment) { e.waiterQueue.Notify(waiter.EventIn) } -// receiveBufferAvailable calculates how many bytes are still available in the -// receive buffer. -func (e *endpoint) receiveBufferAvailable() int { - e.rcvListMu.Lock() - size := e.rcvBufSize - used := e.rcvBufUsed - e.rcvListMu.Unlock() - +// receiveBufferAvailableLocked calculates how many bytes are still available +// in the receive buffer. +// rcvListMu must be held when this function is called. +func (e *endpoint) receiveBufferAvailableLocked() int { // We may use more bytes than the buffer size when the receive buffer // shrinks. - if used >= size { + if e.rcvBufUsed >= e.rcvBufSize { return 0 } - return size - used + return e.rcvBufSize - e.rcvBufUsed +} + +// receiveBufferAvailable calculates how many bytes are still available in the +// receive buffer. +func (e *endpoint) receiveBufferAvailable() int { + e.rcvListMu.Lock() + available := e.receiveBufferAvailableLocked() + e.rcvListMu.Unlock() + return available } func (e *endpoint) receiveBufferSize() int { diff --git a/test/syscalls/BUILD b/test/syscalls/BUILD index 95dc9157b..731e2aa85 100644 --- a/test/syscalls/BUILD +++ b/test/syscalls/BUILD @@ -609,8 +609,6 @@ syscall_test(test = "//test/syscalls/linux:sysret_test") syscall_test( size = "medium", shard_count = 10, - # FIXME(b/135470853) - tags = ["flaky"], test = "//test/syscalls/linux:tcp_socket_test", ) |