4 files changed, 96 insertions, 5 deletions
diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go
index 2e568bc3d..b462924af 100644
--- a/pkg/sentry/socket/netstack/netstack.go
+++ b/pkg/sentry/socket/netstack/netstack.go
@@ -482,8 +482,35 @@ func (s *socketOpsCommon) fetchReadView() *syserr.Error {
 }
 
 // Release implements fs.FileOperations.Release.
-func (s *socketOpsCommon) Release(context.Context) {
+func (s *socketOpsCommon) Release(ctx context.Context) {
+	e, ch := waiter.NewChannelEntry(nil)
+	s.EventRegister(&e, waiter.EventHUp|waiter.EventErr)
+	defer s.EventUnregister(&e)
+
 	s.Endpoint.Close()
+
+	// SO_LINGER option is valid only for TCP. For other socket types
+	// return after endpoint close.
+	if family, skType, _ := s.Type(); skType != linux.SOCK_STREAM || (family != linux.AF_INET && family != linux.AF_INET6) {
+		return
+	}
+
+	var v tcpip.LingerOption
+	if err := s.Endpoint.GetSockOpt(&v); err != nil {
+		return
+	}
+
+	// The case for zero timeout is handled in tcp endpoint close function.
+	// Close is blocked until either:
+	// 1. The endpoint state is not in any of the states: FIN-WAIT1,
+	// CLOSING and LAST_ACK.
+	// 2. Timeout is reached.
+	if v.Enabled && v.Timeout != 0 {
+		t := kernel.TaskFromContext(ctx)
+		start := t.Kernel().MonotonicClock().Now()
+		deadline := start.Add(v.Timeout)
+		t.BlockWithDeadline(ch, true, deadline)
+	}
 }
 
 // Read implements fs.FileOperations.Read.
@@ -1155,7 +1182,16 @@ func getSockOptSocket(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, fam
 			return nil, syserr.ErrInvalidArgument
 		}
 
-		linger := linux.Linger{}
+		var v tcpip.LingerOption
+		var linger linux.Linger
+		if err := ep.GetSockOpt(&v); err != nil {
+			return &linger, nil
+		}
+
+		if v.Enabled {
+			linger.OnOff = 1
+		}
+		linger.Linger = int32(v.Timeout.Seconds())
 		return &linger, nil
 
 	case linux.SO_SNDTIMEO:
@@ -1884,7 +1920,10 @@ func setSockOptSocket(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, nam
 			socket.SetSockOptEmitUnimplementedEvent(t, name)
 		}
 
-		return nil
+		return syserr.TranslateNetstackError(
+			ep.SetSockOpt(&tcpip.LingerOption{
+				Enabled: v.OnOff != 0,
+				Timeout: time.Second * time.Duration(v.Linger)}))
 
 	case linux.SO_DETACH_FILTER:
 		// optval is ignored.
diff --git a/pkg/sentry/socket/unix/transport/unix.go b/pkg/sentry/socket/unix/transport/unix.go
index cbbdd000f..08504560c 100644
--- a/pkg/sentry/socket/unix/transport/unix.go
+++ b/pkg/sentry/socket/unix/transport/unix.go
@@ -945,8 +945,14 @@ func (e *baseEndpoint) GetSockOptInt(opt tcpip.SockOptInt) (int, *tcpip.Error) {
 
 // GetSockOpt implements tcpip.Endpoint.GetSockOpt.
 func (e *baseEndpoint) GetSockOpt(opt tcpip.GettableSocketOption) *tcpip.Error {
-	log.Warningf("Unsupported socket option: %T", opt)
-	return tcpip.ErrUnknownProtocolOption
+	switch opt.(type) {
+	case *tcpip.LingerOption:
+		return nil
+
+	default:
+		log.Warningf("Unsupported socket option: %T", opt)
+		return tcpip.ErrUnknownProtocolOption
+	}
 }
 
 // LastError implements Endpoint.LastError.
diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go
index 5e34e27ba..b2ddb24ec 100644
--- a/pkg/tcpip/tcpip.go
+++ b/pkg/tcpip/tcpip.go
@@ -1194,6 +1194,19 @@ const (
 	TCPTimeWaitReuseLoopbackOnly
 )
 
+// LingerOption is used by SetSockOpt/GetSockOpt to set/get the
+// duration for which a socket lingers before returning from Close.
+//
+// +stateify savable
+type LingerOption struct {
+	Enabled bool
+	Timeout time.Duration
+}
+
+func (*LingerOption) isGettableSocketOption() {}
+
+func (*LingerOption) isSettableSocketOption() {}
+
 // IPPacketInfo is the message structure for IP_PKTINFO.
 //
 // +stateify savable
diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index 6d5046a3d..faea7f2bb 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -654,6 +654,9 @@ type endpoint struct {
 
 	// owner is used to get uid and gid of the packet.
 	owner tcpip.PacketOwner
+
+	// linger is used for SO_LINGER socket option.
+	linger tcpip.LingerOption
 }
 
 // UniqueID implements stack.TransportEndpoint.UniqueID.
@@ -1007,6 +1010,26 @@ func (e *endpoint) Close() {
 		return
 	}
 
+	if e.linger.Enabled && e.linger.Timeout == 0 {
+		s := e.EndpointState()
+		isResetState := s == StateEstablished || s == StateCloseWait || s == StateFinWait1 || s == StateFinWait2 || s == StateSynRecv
+		if isResetState {
+			// Close the endpoint without doing full shutdown and
+			// send a RST.
+			e.resetConnectionLocked(tcpip.ErrConnectionAborted)
+			e.closeNoShutdownLocked()
+
+			// Wake up worker to close the endpoint.
+			switch s {
+			case StateSynRecv:
+				e.notifyProtocolGoroutine(notifyClose)
+			default:
+				e.notifyProtocolGoroutine(notifyTickleWorker)
+			}
+			return
+		}
+	}
+
 	// Issue a shutdown so that the peer knows we won't send any more data
 	// if we're connected, or stop accepting if we're listening.
 	e.shutdownLocked(tcpip.ShutdownWrite | tcpip.ShutdownRead)
@@ -1807,6 +1830,11 @@ func (e *endpoint) SetSockOpt(opt tcpip.SettableSocketOption) *tcpip.Error {
 	case *tcpip.SocketDetachFilterOption:
 		return nil
 
+	case *tcpip.LingerOption:
+		e.LockUser()
+		e.linger = *v
+		e.UnlockUser()
+
 	default:
 		return nil
 	}
@@ -2031,6 +2059,11 @@ func (e *endpoint) GetSockOpt(opt tcpip.GettableSocketOption) *tcpip.Error {
 			Port: port,
 		}
 
+	case *tcpip.LingerOption:
+		e.LockUser()
+		*o = e.linger
+		e.UnlockUser()
+
 	default:
 		return tcpip.ErrUnknownProtocolOption
 	}