Automated rollback of changelist 196886839

PiperOrigin-RevId: 198457660
Change-Id: I6ea5cf0b4cfe2b5ba455325a7e5299880e5a088a

6 files changed, 82 insertions, 78 deletions

diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go
index cf25a086d..fdeba6bc4 100644
--- a/pkg/tcpip/tcpip.go
+++ b/pkg/tcpip/tcpip.go
@@ -85,17 +85,6 @@ var (
 	errSubnetAddressMasked  = errors.New("subnet address has bits set outside the mask")
 )
 
-// ErrSaveRejection indicates a failed save due to unsupported networking state.
-// This type of errors is only used for save logic.
-type ErrSaveRejection struct {
-	Err error
-}
-
-// Error returns a sensible description of the save rejection error.
-func (e ErrSaveRejection) Error() string {
-	return "save rejected due to unsupported networking state: " + e.Err.Error()
-}
-
 // A Clock provides the current time.
 //
 // Times returned by a Clock should always be used for application-visible
diff --git a/pkg/tcpip/transport/tcp/accept.go b/pkg/tcpip/transport/tcp/accept.go
index ac213e310..a71cb444f 100644
--- a/pkg/tcpip/transport/tcp/accept.go
+++ b/pkg/tcpip/transport/tcp/accept.go
@@ -349,17 +349,13 @@ func (e *endpoint) protocolListenLoop(rcvWnd seqnum.Size) *tcpip.Error {
 		// to the endpoint.
 		e.mu.Lock()
 		e.state = stateClosed
+		e.mu.Unlock()
 
 		// Notify waiters that the endpoint is shutdown.
 		e.waiterQueue.Notify(waiter.EventIn | waiter.EventOut)
 
 		// Do cleanup if needed.
-		e.completeWorkerLocked()
-
-		if e.drainDone != nil {
-			close(e.drainDone)
-		}
-		e.mu.Unlock()
+		e.completeWorker()
 	}()
 
 	e.mu.Lock()
diff --git a/pkg/tcpip/transport/tcp/connect.go b/pkg/tcpip/transport/tcp/connect.go
index 66904856c..5115dabe6 100644
--- a/pkg/tcpip/transport/tcp/connect.go
+++ b/pkg/tcpip/transport/tcp/connect.go
@@ -690,7 +690,7 @@ func (e *endpoint) sendRaw(data buffer.View, flags byte, seq, ack seqnum.Value,
 	return err
 }
 
-func (e *endpoint) handleWrite() *tcpip.Error {
+func (e *endpoint) handleWrite() bool {
 	// Move packets from send queue to send list. The queue is accessible
 	// from other goroutines and protected by the send mutex, while the send
 	// list is only accessible from the handler goroutine, so it needs no
@@ -714,42 +714,47 @@ func (e *endpoint) handleWrite() *tcpip.Error {
 	// Push out any new packets.
 	e.snd.sendData()
 
-	return nil
+	return true
 }
 
-func (e *endpoint) handleClose() *tcpip.Error {
+func (e *endpoint) handleClose() bool {
 	// Drain the send queue.
 	e.handleWrite()
 
 	// Mark send side as closed.
 	e.snd.closed = true
 
-	return nil
+	return true
 }
 
-// resetConnectionLocked sends a RST segment and puts the endpoint in an error
-// state with the given error code. This method must only be called from the
-// protocol goroutine.
-func (e *endpoint) resetConnectionLocked(err *tcpip.Error) {
+// resetConnection sends a RST segment and puts the endpoint in an error state
+// with the given error code.
+// This method must only be called from the protocol goroutine.
+func (e *endpoint) resetConnection(err *tcpip.Error) {
 	e.sendRaw(nil, flagAck|flagRst, e.snd.sndUna, e.rcv.rcvNxt, 0)
 
+	e.mu.Lock()
 	e.state = stateError
 	e.hardError = err
+	e.mu.Unlock()
 }
 
-// completeWorkerLocked is called by the worker goroutine when it's about to
-// exit. It marks the worker as completed and performs cleanup work if requested
-// by Close().
-func (e *endpoint) completeWorkerLocked() {
+// completeWorker is called by the worker goroutine when it's about to exit. It
+// marks the worker as completed and performs cleanup work if requested by
+// Close().
+func (e *endpoint) completeWorker() {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
 	e.workerRunning = false
 	if e.workerCleanup {
-		e.cleanupLocked()
+		e.cleanup()
 	}
 }
 
 // handleSegments pulls segments from the queue and processes them. It returns
-// no error if the protocol loop should continue, an error otherwise.
-func (e *endpoint) handleSegments() *tcpip.Error {
+// true if the protocol loop should continue, false otherwise.
+func (e *endpoint) handleSegments() bool {
 	checkRequeue := true
 	for i := 0; i < maxSegmentsPerWake; i++ {
 		s := e.segmentQueue.dequeue()
@@ -770,7 +775,11 @@ func (e *endpoint) handleSegments() *tcpip.Error {
 				// validated by checking their SEQ-fields." So
 				// we only process it if it's acceptable.
 				s.decRef()
-				return tcpip.ErrConnectionReset
+				e.mu.Lock()
+				e.state = stateError
+				e.hardError = tcpip.ErrConnectionReset
+				e.mu.Unlock()
+				return false
 			}
 		} else if s.flagIsSet(flagAck) {
 			// Patch the window size in the segment according to the
@@ -807,7 +816,7 @@ func (e *endpoint) handleSegments() *tcpip.Error {
 		e.snd.sendAck()
 	}
 
-	return nil
+	return true
 }
 
 // protocolMainLoop is the main loop of the TCP protocol. It runs in its own
@@ -818,10 +827,9 @@ func (e *endpoint) protocolMainLoop(passive bool) *tcpip.Error {
 	var closeWaker sleep.Waker
 
 	defer func() {
-		// e.mu is expected to be held upon entering this section.
 		// When the protocol loop exits we should wake up our waiters.
 		e.waiterQueue.Notify(waiter.EventHUp | waiter.EventErr | waiter.EventIn | waiter.EventOut)
-		e.completeWorkerLocked()
+		e.completeWorker()
 
 		if e.snd != nil {
 			e.snd.resendTimer.cleanup()
@@ -830,12 +838,6 @@ func (e *endpoint) protocolMainLoop(passive bool) *tcpip.Error {
 		if closeTimer != nil {
 			closeTimer.Stop()
 		}
-
-		if e.drainDone != nil {
-			close(e.drainDone)
-		}
-
-		e.mu.Unlock()
 	}()
 
 	if !passive {
@@ -854,7 +856,12 @@ func (e *endpoint) protocolMainLoop(passive bool) *tcpip.Error {
 			e.mu.Lock()
 			e.state = stateError
 			e.hardError = err
-			// Lock released in deferred statement.
+			drained := e.drainDone != nil
+			e.mu.Unlock()
+			if drained {
+				close(e.drainDone)
+				<-e.undrain
+			}
 
 			return err
 		}
@@ -885,7 +892,7 @@ func (e *endpoint) protocolMainLoop(passive bool) *tcpip.Error {
 	// wakes up.
 	funcs := []struct {
 		w *sleep.Waker
-		f func() *tcpip.Error
+		f func() bool
 	}{
 		{
 			w: &e.sndWaker,
@@ -901,22 +908,24 @@ func (e *endpoint) protocolMainLoop(passive bool) *tcpip.Error {
 		},
 		{
 			w: &closeWaker,
-			f: func() *tcpip.Error {
-				return tcpip.ErrConnectionAborted
+			f: func() bool {
+				e.resetConnection(tcpip.ErrConnectionAborted)
+				return false
 			},
 		},
 		{
 			w: &e.snd.resendWaker,
-			f: func() *tcpip.Error {
+			f: func() bool {
 				if !e.snd.retransmitTimerExpired() {
-					return tcpip.ErrTimeout
+					e.resetConnection(tcpip.ErrTimeout)
+					return false
 				}
-				return nil
+				return true
 			},
 		},
 		{
 			w: &e.notificationWaker,
-			f: func() *tcpip.Error {
+			f: func() bool {
 				n := e.fetchNotifications()
 				if n&notifyNonZeroReceiveWindow != 0 {
 					e.rcv.nonZeroWindow()
@@ -943,7 +952,7 @@ func (e *endpoint) protocolMainLoop(passive bool) *tcpip.Error {
 						closeWaker.Assert()
 					})
 				}
-				return nil
+				return true
 			},
 		},
 	}
@@ -960,10 +969,7 @@ func (e *endpoint) protocolMainLoop(passive bool) *tcpip.Error {
 		e.workMu.Unlock()
 		v, _ := s.Fetch(true)
 		e.workMu.Lock()
-		if err := funcs[v].f(); err != nil {
-			e.mu.Lock()
-			e.resetConnectionLocked(err)
-			// Lock released in deferred statement.
+		if !funcs[v].f() {
 			return nil
 		}
 	}
@@ -971,7 +977,7 @@ func (e *endpoint) protocolMainLoop(passive bool) *tcpip.Error {
 	// Mark endpoint as closed.
 	e.mu.Lock()
 	e.state = stateClosed
-	// Lock released in deferred statement.
+	e.mu.Unlock()
 
 	return nil
 }
diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index 3f87c4cac..f26b28632 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -94,7 +94,7 @@ type endpoint struct {
 	state             endpointState
 	isPortReserved    bool `state:"manual"`
 	isRegistered      bool
-	boundNICID        tcpip.NICID `state:"manual"`
+	boundNICID        tcpip.NICID
 	route             stack.Route `state:"manual"`
 	v6only            bool
 	isConnectNotified bool
@@ -118,7 +118,7 @@ type endpoint struct {
 	// workerCleanup specifies if the worker goroutine must perform cleanup
 	// before exitting. This can only be set to true when workerRunning is
 	// also true, and they're both protected by the mutex.
-	workerCleanup bool `state:"zerovalue"`
+	workerCleanup bool
 
 	// sendTSOk is used to indicate when the TS Option has been negotiated.
 	// When sendTSOk is true every non-RST segment should carry a TS as per
@@ -326,7 +326,13 @@ func (e *endpoint) Close() {
 	// if we're connected, or stop accepting if we're listening.
 	e.Shutdown(tcpip.ShutdownWrite | tcpip.ShutdownRead)
 
+	// While we hold the lock, determine if the cleanup should happen
+	// inline or if we should tell the worker (if any) to do the cleanup.
 	e.mu.Lock()
+	worker := e.workerRunning
+	if worker {
+		e.workerCleanup = true
+	}
 
 	// We always release ports inline so that they are immediately available
 	// for reuse after Close() is called. If also registered, it means this
@@ -342,32 +348,29 @@ func (e *endpoint) Close() {
 		}
 	}
 
-	// Either perform the local cleanup or kick the worker to make sure it
-	// knows it needs to cleanup.
-	if !e.workerRunning {
-		e.cleanupLocked()
+	e.mu.Unlock()
+
+	// Now that we don't hold the lock anymore, either perform the local
+	// cleanup or kick the worker to make sure it knows it needs to cleanup.
+	if !worker {
+		e.cleanup()
 	} else {
-		e.workerCleanup = true
 		e.notifyProtocolGoroutine(notifyClose)
 	}
-
-	e.mu.Unlock()
 }
 
-// cleanupLocked frees all resources associated with the endpoint. It is called
-// after Close() is called and the worker goroutine (if any) is done with its
-// work.
-func (e *endpoint) cleanupLocked() {
+// cleanup frees all resources associated with the endpoint. It is called after
+// Close() is called and the worker goroutine (if any) is done with its work.
+func (e *endpoint) cleanup() {
 	// Close all endpoints that might have been accepted by TCP but not by
 	// the client.
 	if e.acceptedChan != nil {
 		close(e.acceptedChan)
 		for n := range e.acceptedChan {
-			n.resetConnectionLocked(tcpip.ErrConnectionAborted)
+			n.resetConnection(tcpip.ErrConnectionAborted)
 			n.Close()
 		}
 	}
-	e.workerCleanup = false
 
 	if e.isRegistered {
 		e.stack.UnregisterTransportEndpoint(e.boundNICID, e.effectiveNetProtos, ProtocolNumber, e.id)
diff --git a/pkg/tcpip/transport/tcp/endpoint_state.go b/pkg/tcpip/transport/tcp/endpoint_state.go
index b1e249bff..deef670d5 100644
--- a/pkg/tcpip/transport/tcp/endpoint_state.go
+++ b/pkg/tcpip/transport/tcp/endpoint_state.go
@@ -12,6 +12,17 @@ import (
 	"gvisor.googlesource.com/gvisor/pkg/tcpip/stack"
 )
 
+// ErrSaveRejection indicates a failed save due to unsupported tcp endpoint
+// state.
+type ErrSaveRejection struct {
+	Err error
+}
+
+// Error returns a sensible description of the save rejection error.
+func (e ErrSaveRejection) Error() string {
+	return "save rejected due to unsupported endpoint state: " + e.Err.Error()
+}
+
 func (e *endpoint) drainSegmentLocked() {
 	// Drain only up to once.
 	if e.drainDone != nil {
@@ -37,7 +48,8 @@ func (e *endpoint) beforeSave() {
 	defer e.mu.Unlock()
 
 	switch e.state {
-	case stateInitial, stateBound:
+	case stateInitial:
+	case stateBound:
 	case stateListen:
 		if !e.segmentQueue.empty() {
 			e.drainSegmentLocked()
@@ -50,11 +62,9 @@ func (e *endpoint) beforeSave() {
 		fallthrough
 	case stateConnected:
 		// FIXME
-		panic(tcpip.ErrSaveRejection{fmt.Errorf("endpoint cannot be saved in connected state: local %v:%v, remote %v:%v", e.id.LocalAddress, e.id.LocalPort, e.id.RemoteAddress, e.id.RemotePort)})
-	case stateClosed, stateError:
-		if e.workerRunning {
-			panic(fmt.Sprintf("endpoint still has worker running in closed or error state"))
-		}
+		panic(ErrSaveRejection{fmt.Errorf("endpoint cannot be saved in connected state: local %v:%v, remote %v:%v", e.id.LocalAddress, e.id.LocalPort, e.id.RemoteAddress, e.id.RemotePort)})
+	case stateClosed:
+	case stateError:
 	default:
 		panic(fmt.Sprintf("endpoint in unknown state %v", e.state))
 	}
diff --git a/pkg/tcpip/transport/tcp/segment.go b/pkg/tcpip/transport/tcp/segment.go
index 07e4bfd73..c742fc394 100644
--- a/pkg/tcpip/transport/tcp/segment.go
+++ b/pkg/tcpip/transport/tcp/segment.go
@@ -30,7 +30,7 @@ type segment struct {
 	segmentEntry
 	refCnt int32
 	id     stack.TransportEndpointID
-	route  stack.Route `state:"manual"`
+	route  stack.Route
 	data   buffer.VectorisedView
 	// views is used as buffer for data when its length is large
 	// enough to store a VectorisedView.