Implement SO_SNDTIMEO

PiperOrigin-RevId: 225620490
Change-Id: Ia726107b3f58093a5f881634f90b071b32d2c269

9 files changed, 153 insertions, 41 deletions

diff --git a/pkg/sentry/fs/host/BUILD b/pkg/sentry/fs/host/BUILD
index 89d7b2fe7..73d9cc71a 100644
--- a/pkg/sentry/fs/host/BUILD
+++ b/pkg/sentry/fs/host/BUILD
@@ -71,6 +71,7 @@ go_test(
         "//pkg/sentry/context",
         "//pkg/sentry/context/contexttest",
         "//pkg/sentry/fs",
+        "//pkg/sentry/kernel/time",
         "//pkg/sentry/socket",
         "//pkg/sentry/socket/unix/transport",
         "//pkg/sentry/usermem",
diff --git a/pkg/sentry/fs/host/socket_test.go b/pkg/sentry/fs/host/socket_test.go
index 17bf397ef..6ddf63a6a 100644
--- a/pkg/sentry/fs/host/socket_test.go
+++ b/pkg/sentry/fs/host/socket_test.go
@@ -21,6 +21,7 @@ import (
 
 	"gvisor.googlesource.com/gvisor/pkg/fd"
 	"gvisor.googlesource.com/gvisor/pkg/sentry/context/contexttest"
+	ktime "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/time"
 	"gvisor.googlesource.com/gvisor/pkg/sentry/socket"
 	"gvisor.googlesource.com/gvisor/pkg/sentry/socket/unix/transport"
 	"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
@@ -142,7 +143,7 @@ func TestSocketSendMsgLen0(t *testing.T) {
 	defer sfile.DecRef()
 
 	s := sfile.FileOperations.(socket.Socket)
-	n, terr := s.SendMsg(nil, usermem.BytesIOSequence(nil), []byte{}, 0, socket.ControlMessages{})
+	n, terr := s.SendMsg(nil, usermem.BytesIOSequence(nil), []byte{}, 0, false, ktime.Time{}, socket.ControlMessages{})
 	if n != 0 {
 		t.Fatalf("socket sendmsg() failed: %v wrote: %d", terr, n)
 	}
diff --git a/pkg/sentry/socket/epsocket/epsocket.go b/pkg/sentry/socket/epsocket/epsocket.go
index 19af7bc45..ab5d82183 100644
--- a/pkg/sentry/socket/epsocket/epsocket.go
+++ b/pkg/sentry/socket/epsocket/epsocket.go
@@ -30,6 +30,7 @@ import (
 	"strings"
 	"sync"
 	"syscall"
+	"time"
 
 	"gvisor.googlesource.com/gvisor/pkg/abi/linux"
 	"gvisor.googlesource.com/gvisor/pkg/binary"
@@ -137,12 +138,12 @@ type commonEndpoint interface {
 //
 // +stateify savable
 type SocketOperations struct {
-	socket.ReceiveTimeout
 	fsutil.PipeSeek      `state:"nosave"`
 	fsutil.NotDirReaddir `state:"nosave"`
 	fsutil.NoFsync       `state:"nosave"`
 	fsutil.NoopFlush     `state:"nosave"`
 	fsutil.NoMMap        `state:"nosave"`
+	socket.SendReceiveTimeout
 	*waiter.Queue
 
 	family   int
@@ -643,7 +644,16 @@ func getSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, family
 		}
 		return syscall.Linger{}, nil
 
+	case linux.SO_SNDTIMEO:
+		// TODO: Linux allows shorter lengths for partial results.
+		if outLen < linux.SizeOfTimeval {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		return linux.NsecToTimeval(s.SendTimeout()), nil
+
 	case linux.SO_RCVTIMEO:
+		// TODO: Linux allows shorter lengths for partial results.
 		if outLen < linux.SizeOfTimeval {
 			return nil, syserr.ErrInvalidArgument
 		}
@@ -833,6 +843,19 @@ func setSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, name i
 		v := usermem.ByteOrder.Uint32(optVal)
 		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.PasscredOption(v)))
 
+	case linux.SO_SNDTIMEO:
+		if len(optVal) < linux.SizeOfTimeval {
+			return syserr.ErrInvalidArgument
+		}
+
+		var v linux.Timeval
+		binary.Unmarshal(optVal[:linux.SizeOfTimeval], usermem.ByteOrder, &v)
+		if v.Usec < 0 || v.Usec >= int64(time.Second/time.Microsecond) {
+			return syserr.ErrDomain
+		}
+		s.SetSendTimeout(v.ToNsecCapped())
+		return nil
+
 	case linux.SO_RCVTIMEO:
 		if len(optVal) < linux.SizeOfTimeval {
 			return syserr.ErrInvalidArgument
@@ -840,6 +863,9 @@ func setSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, name i
 
 		var v linux.Timeval
 		binary.Unmarshal(optVal[:linux.SizeOfTimeval], usermem.ByteOrder, &v)
+		if v.Usec < 0 || v.Usec >= int64(time.Second/time.Microsecond) {
+			return syserr.ErrDomain
+		}
 		s.SetRecvTimeout(v.ToNsecCapped())
 		return nil
 
@@ -1365,7 +1391,7 @@ func (s *SocketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags
 
 // SendMsg implements the linux syscall sendmsg(2) for sockets backed by
 // tcpip.Endpoint.
-func (s *SocketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, controlMessages socket.ControlMessages) (int, *syserr.Error) {
+func (s *SocketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, haveDeadline bool, deadline ktime.Time, controlMessages socket.ControlMessages) (int, *syserr.Error) {
 	// Reject Unix control messages.
 	if !controlMessages.Unix.Empty() {
 		return 0, syserr.ErrInvalidArgument
@@ -1431,7 +1457,10 @@ func (s *SocketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to []
 			return int(total), nil
 		}
 
-		if err := t.Block(ch); err != nil {
+		if err := t.BlockWithDeadline(ch, haveDeadline, deadline); err != nil {
+			if err == syserror.ETIMEDOUT {
+				return int(total), syserr.ErrTryAgain
+			}
 			// handleIOError will consume errors from t.Block if needed.
 			return int(total), syserr.FromError(err)
 		}
diff --git a/pkg/sentry/socket/hostinet/socket.go b/pkg/sentry/socket/hostinet/socket.go
index e4e950fbb..34281cac0 100644
--- a/pkg/sentry/socket/hostinet/socket.go
+++ b/pkg/sentry/socket/hostinet/socket.go
@@ -46,12 +46,12 @@ const (
 // socketOperations implements fs.FileOperations and socket.Socket for a socket
 // implemented using a host socket.
 type socketOperations struct {
-	socket.ReceiveTimeout
 	fsutil.PipeSeek      `state:"nosave"`
 	fsutil.NotDirReaddir `state:"nosave"`
 	fsutil.NoFsync       `state:"nosave"`
 	fsutil.NoopFlush     `state:"nosave"`
 	fsutil.NoMMap        `state:"nosave"`
+	socket.SendReceiveTimeout
 
 	fd    int // must be O_NONBLOCK
 	queue waiter.Queue
@@ -418,7 +418,7 @@ func (s *socketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags
 }
 
 // SendMsg implements socket.Socket.SendMsg.
-func (s *socketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, controlMessages socket.ControlMessages) (int, *syserr.Error) {
+func (s *socketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, haveDeadline bool, deadline ktime.Time, controlMessages socket.ControlMessages) (int, *syserr.Error) {
 	// Whitelist flags.
 	if flags&^(syscall.MSG_DONTWAIT|syscall.MSG_EOR|syscall.MSG_FASTOPEN|syscall.MSG_MORE|syscall.MSG_NOSIGNAL) != 0 {
 		return 0, syserr.ErrInvalidArgument
@@ -468,7 +468,10 @@ func (s *socketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to []
 				panic(fmt.Sprintf("CopyInTo: got (%d, %v), wanted (0, %v)", n, err, err))
 			}
 			if ch != nil {
-				if err = t.Block(ch); err != nil {
+				if err = t.BlockWithDeadline(ch, haveDeadline, deadline); err != nil {
+					if err == syserror.ETIMEDOUT {
+						err = syserror.ErrWouldBlock
+					}
 					break
 				}
 			} else {
diff --git a/pkg/sentry/socket/netlink/socket.go b/pkg/sentry/socket/netlink/socket.go
index c4798839e..0a7d4772c 100644
--- a/pkg/sentry/socket/netlink/socket.go
+++ b/pkg/sentry/socket/netlink/socket.go
@@ -65,12 +65,12 @@ var netlinkSocketDevice = device.NewAnonDevice()
 //
 // +stateify savable
 type Socket struct {
-	socket.ReceiveTimeout
 	fsutil.PipeSeek      `state:"nosave"`
 	fsutil.NotDirReaddir `state:"nosave"`
 	fsutil.NoFsync       `state:"nosave"`
 	fsutil.NoopFlush     `state:"nosave"`
 	fsutil.NoMMap        `state:"nosave"`
+	socket.SendReceiveTimeout
 
 	// ports provides netlink port allocation.
 	ports *port.Manager
@@ -593,7 +593,7 @@ func (s *Socket) sendMsg(ctx context.Context, src usermem.IOSequence, to []byte,
 }
 
 // SendMsg implements socket.Socket.SendMsg.
-func (s *Socket) SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, controlMessages socket.ControlMessages) (int, *syserr.Error) {
+func (s *Socket) SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, haveDeadline bool, deadline ktime.Time, controlMessages socket.ControlMessages) (int, *syserr.Error) {
 	return s.sendMsg(t, src, to, flags, controlMessages)
 }
 
diff --git a/pkg/sentry/socket/rpcinet/socket.go b/pkg/sentry/socket/rpcinet/socket.go
index 90844f10f..257bc2d71 100644
--- a/pkg/sentry/socket/rpcinet/socket.go
+++ b/pkg/sentry/socket/rpcinet/socket.go
@@ -17,6 +17,7 @@ package rpcinet
 import (
 	"sync/atomic"
 	"syscall"
+	"time"
 
 	"gvisor.googlesource.com/gvisor/pkg/abi/linux"
 	"gvisor.googlesource.com/gvisor/pkg/binary"
@@ -44,12 +45,12 @@ import (
 // socketOperations implements fs.FileOperations and socket.Socket for a socket
 // implemented using a host socket.
 type socketOperations struct {
-	socket.ReceiveTimeout
 	fsutil.PipeSeek      `state:"nosave"`
 	fsutil.NotDirReaddir `state:"nosave"`
 	fsutil.NoFsync       `state:"nosave"`
 	fsutil.NoopFlush     `state:"nosave"`
 	fsutil.NoMMap        `state:"nosave"`
+	socket.SendReceiveTimeout
 
 	fd       uint32 // must be O_NONBLOCK
 	wq       *waiter.Queue
@@ -379,7 +380,8 @@ func (s *socketOperations) Shutdown(t *kernel.Task, how int) *syserr.Error {
 
 // GetSockOpt implements socket.Socket.GetSockOpt.
 func (s *socketOperations) GetSockOpt(t *kernel.Task, level int, name int, outLen int) (interface{}, *syserr.Error) {
-	// SO_RCVTIMEO is special because blocking is performed within the sentry.
+	// SO_RCVTIMEO and SO_SNDTIMEO are special because blocking is performed
+	// within the sentry.
 	if level == linux.SOL_SOCKET && name == linux.SO_RCVTIMEO {
 		if outLen < linux.SizeOfTimeval {
 			return nil, syserr.ErrInvalidArgument
@@ -387,6 +389,13 @@ func (s *socketOperations) GetSockOpt(t *kernel.Task, level int, name int, outLe
 
 		return linux.NsecToTimeval(s.RecvTimeout()), nil
 	}
+	if level == linux.SOL_SOCKET && name == linux.SO_SNDTIMEO {
+		if outLen < linux.SizeOfTimeval {
+			return nil, syserr.ErrInvalidArgument
+		}
+
+		return linux.NsecToTimeval(s.SendTimeout()), nil
+	}
 
 	stack := t.NetworkContext().(*Stack)
 	id, c := stack.rpcConn.NewRequest(pb.SyscallRequest{Args: &pb.SyscallRequest_GetSockOpt{&pb.GetSockOptRequest{Fd: s.fd, Level: int64(level), Name: int64(name), Length: uint32(outLen)}}}, false /* ignoreResult */)
@@ -403,8 +412,9 @@ func (s *socketOperations) GetSockOpt(t *kernel.Task, level int, name int, outLe
 // SetSockOpt implements socket.Socket.SetSockOpt.
 func (s *socketOperations) SetSockOpt(t *kernel.Task, level int, name int, opt []byte) *syserr.Error {
 	// Because blocking actually happens within the sentry we need to inspect
-	// this socket option to determine if it's a SO_RCVTIMEO, and if so, we will
-	// save it and use it as the deadline for recv(2) related syscalls.
+	// this socket option to determine if it's a SO_RCVTIMEO or SO_SNDTIMEO,
+	// and if so, we will save it and use it as the deadline for recv(2)
+	// or send(2) related syscalls.
 	if level == linux.SOL_SOCKET && name == linux.SO_RCVTIMEO {
 		if len(opt) < linux.SizeOfTimeval {
 			return syserr.ErrInvalidArgument
@@ -412,9 +422,25 @@ func (s *socketOperations) SetSockOpt(t *kernel.Task, level int, name int, opt [
 
 		var v linux.Timeval
 		binary.Unmarshal(opt[:linux.SizeOfTimeval], usermem.ByteOrder, &v)
+		if v.Usec < 0 || v.Usec >= int64(time.Second/time.Microsecond) {
+			return syserr.ErrDomain
+		}
 		s.SetRecvTimeout(v.ToNsecCapped())
 		return nil
 	}
+	if level == linux.SOL_SOCKET && name == linux.SO_SNDTIMEO {
+		if len(opt) < linux.SizeOfTimeval {
+			return syserr.ErrInvalidArgument
+		}
+
+		var v linux.Timeval
+		binary.Unmarshal(opt[:linux.SizeOfTimeval], usermem.ByteOrder, &v)
+		if v.Usec < 0 || v.Usec >= int64(time.Second/time.Microsecond) {
+			return syserr.ErrDomain
+		}
+		s.SetSendTimeout(v.ToNsecCapped())
+		return nil
+	}
 
 	stack := t.NetworkContext().(*Stack)
 	id, c := stack.rpcConn.NewRequest(pb.SyscallRequest{Args: &pb.SyscallRequest_SetSockOpt{&pb.SetSockOptRequest{Fd: s.fd, Level: int64(level), Name: int64(name), Opt: opt}}}, false /* ignoreResult */)
@@ -720,7 +746,7 @@ func rpcSendMsg(t *kernel.Task, req *pb.SyscallRequest_Sendmsg) (uint32, *syserr
 }
 
 // SendMsg implements socket.Socket.SendMsg.
-func (s *socketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, controlMessages socket.ControlMessages) (int, *syserr.Error) {
+func (s *socketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, haveDeadline bool, deadline ktime.Time, controlMessages socket.ControlMessages) (int, *syserr.Error) {
 	// Whitelist flags.
 	if flags&^(syscall.MSG_DONTWAIT|syscall.MSG_EOR|syscall.MSG_FASTOPEN|syscall.MSG_MORE|syscall.MSG_NOSIGNAL) != 0 {
 		return 0, syserr.ErrInvalidArgument
@@ -787,7 +813,10 @@ func (s *socketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to []
 			return int(totalWritten), nil
 		}
 
-		if err := t.Block(ch); err != nil {
+		if err := t.BlockWithDeadline(ch, haveDeadline, deadline); err != nil {
+			if err == syserror.ETIMEDOUT {
+				return int(totalWritten), syserr.ErrTryAgain
+			}
 			return int(totalWritten), syserr.FromError(err)
 		}
 	}
diff --git a/pkg/sentry/socket/socket.go b/pkg/sentry/socket/socket.go
index f73127ea6..9d4aaeb9d 100644
--- a/pkg/sentry/socket/socket.go
+++ b/pkg/sentry/socket/socket.go
@@ -94,15 +94,23 @@ type Socket interface {
 	// ownership of the ControlMessage on error.
 	//
 	// If n > 0, err will either be nil or an error from t.Block.
-	SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, controlMessages ControlMessages) (n int, err *syserr.Error)
+	SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, haveDeadline bool, deadline ktime.Time, controlMessages ControlMessages) (n int, err *syserr.Error)
 
 	// SetRecvTimeout sets the timeout (in ns) for recv operations. Zero means
-	// no timeout.
+	// no timeout, and negative means DONTWAIT.
 	SetRecvTimeout(nanoseconds int64)
 
 	// RecvTimeout gets the current timeout (in ns) for recv operations. Zero
-	// means no timeout.
+	// means no timeout, and negative means DONTWAIT.
 	RecvTimeout() int64
+
+	// SetSendTimeout sets the timeout (in ns) for send operations. Zero means
+	// no timeout, and negative means DONTWAIT.
+	SetSendTimeout(nanoseconds int64)
+
+	// SendTimeout gets the current timeout (in ns) for send operations. Zero
+	// means no timeout, and negative means DONTWAIT.
+	SendTimeout() int64
 }
 
 // Provider is the interface implemented by providers of sockets for specific
@@ -192,30 +200,45 @@ func NewDirent(ctx context.Context, d *device.Device) *fs.Dirent {
 	return fs.NewDirent(inode, fmt.Sprintf("socket:[%d]", ino))
 }
 
-// ReceiveTimeout stores a timeout for receive calls.
+// SendReceiveTimeout stores timeouts for send and receive calls.
 //
 // It is meant to be embedded into Socket implementations to help satisfy the
 // interface.
 //
-// Care must be taken when copying ReceiveTimeout as it contains atomic
+// Care must be taken when copying SendReceiveTimeout as it contains atomic
 // variables.
 //
 // +stateify savable
-type ReceiveTimeout struct {
-	// ns is length of the timeout in nanoseconds.
+type SendReceiveTimeout struct {
+	// send is length of the send timeout in nanoseconds.
+	//
+	// send must be accessed atomically.
+	send int64
+
+	// recv is length of the receive timeout in nanoseconds.
 	//
-	// ns must be accessed atomically.
-	ns int64
+	// recv must be accessed atomically.
+	recv int64
 }
 
 // SetRecvTimeout implements Socket.SetRecvTimeout.
-func (rt *ReceiveTimeout) SetRecvTimeout(nanoseconds int64) {
-	atomic.StoreInt64(&rt.ns, nanoseconds)
+func (to *SendReceiveTimeout) SetRecvTimeout(nanoseconds int64) {
+	atomic.StoreInt64(&to.recv, nanoseconds)
 }
 
 // RecvTimeout implements Socket.RecvTimeout.
-func (rt *ReceiveTimeout) RecvTimeout() int64 {
-	return atomic.LoadInt64(&rt.ns)
+func (to *SendReceiveTimeout) RecvTimeout() int64 {
+	return atomic.LoadInt64(&to.recv)
+}
+
+// SetSendTimeout implements Socket.SetSendTimeout.
+func (to *SendReceiveTimeout) SetSendTimeout(nanoseconds int64) {
+	atomic.StoreInt64(&to.send, nanoseconds)
+}
+
+// SendTimeout implements Socket.SendTimeout.
+func (to *SendReceiveTimeout) SendTimeout() int64 {
+	return atomic.LoadInt64(&to.send)
 }
 
 // GetSockOptEmitUnimplementedEvent emits unimplemented event if name is valid.
diff --git a/pkg/sentry/socket/unix/unix.go b/pkg/sentry/socket/unix/unix.go
index 4c9dcbd61..da225eabb 100644
--- a/pkg/sentry/socket/unix/unix.go
+++ b/pkg/sentry/socket/unix/unix.go
@@ -45,15 +45,16 @@ import (
 //
 // +stateify savable
 type SocketOperations struct {
-	refs.AtomicRefCount
-	socket.ReceiveTimeout
 	fsutil.PipeSeek      `state:"nosave"`
 	fsutil.NotDirReaddir `state:"nosave"`
 	fsutil.NoFsync       `state:"nosave"`
 	fsutil.NoopFlush     `state:"nosave"`
 	fsutil.NoMMap        `state:"nosave"`
-	ep                   transport.Endpoint
-	isPacket             bool
+	refs.AtomicRefCount
+	socket.SendReceiveTimeout
+
+	ep       transport.Endpoint
+	isPacket bool
 }
 
 // New creates a new unix socket.
@@ -367,7 +368,7 @@ func (s *SocketOperations) Write(ctx context.Context, _ *fs.File, src usermem.IO
 
 // SendMsg implements the linux syscall sendmsg(2) for unix sockets backed by
 // a transport.Endpoint.
-func (s *SocketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, controlMessages socket.ControlMessages) (int, *syserr.Error) {
+func (s *SocketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to []byte, flags int, haveDeadline bool, deadline ktime.Time, controlMessages socket.ControlMessages) (int, *syserr.Error) {
 	w := EndpointWriter{
 		Endpoint: s.ep,
 		Control:  controlMessages.Unix,
@@ -404,7 +405,10 @@ func (s *SocketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to []
 			break
 		}
 
-		if err := t.Block(ch); err != nil {
+		if err = t.BlockWithDeadline(ch, haveDeadline, deadline); err != nil {
+			if err == syserror.ETIMEDOUT {
+				err = syserror.ErrWouldBlock
+			}
 			break
 		}
 	}
diff --git a/pkg/sentry/syscalls/linux/sys_socket.go b/pkg/sentry/syscalls/linux/sys_socket.go
index 1165d4566..3049fe6e5 100644
--- a/pkg/sentry/syscalls/linux/sys_socket.go
+++ b/pkg/sentry/syscalls/linux/sys_socket.go
@@ -612,9 +612,11 @@ func RecvMsg(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysca
 
 	var haveDeadline bool
 	var deadline ktime.Time
-	if dl := s.RecvTimeout(); dl != 0 {
+	if dl := s.RecvTimeout(); dl > 0 {
 		deadline = t.Kernel().MonotonicClock().Now().Add(time.Duration(dl) * time.Nanosecond)
 		haveDeadline = true
+	} else if dl < 0 {
+		flags |= linux.MSG_DONTWAIT
 	}
 
 	n, err := recvSingleMsg(t, s, msgPtr, flags, haveDeadline, deadline)
@@ -671,10 +673,11 @@ func RecvMMsg(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc
 	}
 
 	if !haveDeadline {
-		dl := s.RecvTimeout()
-		if dl != 0 {
+		if dl := s.RecvTimeout(); dl > 0 {
 			deadline = t.Kernel().MonotonicClock().Now().Add(time.Duration(dl) * time.Nanosecond)
 			haveDeadline = true
+		} else if dl < 0 {
+			flags |= linux.MSG_DONTWAIT
 		}
 	}
 
@@ -821,10 +824,11 @@ func recvFrom(t *kernel.Task, fd kdefs.FD, bufPtr usermem.Addr, bufLen uint64, f
 
 	var haveDeadline bool
 	var deadline ktime.Time
-
-	if dl := s.RecvTimeout(); dl != 0 {
+	if dl := s.RecvTimeout(); dl > 0 {
 		deadline = t.Kernel().MonotonicClock().Now().Add(time.Duration(dl) * time.Nanosecond)
 		haveDeadline = true
+	} else if dl < 0 {
+		flags |= linux.MSG_DONTWAIT
 	}
 
 	n, sender, senderLen, cm, e := s.RecvMsg(t, dst, int(flags), haveDeadline, deadline, nameLenPtr != 0, 0)
@@ -1001,8 +1005,17 @@ func sendSingleMsg(t *kernel.Task, s socket.Socket, file *fs.File, msgPtr userme
 		return 0, err
 	}
 
+	var haveDeadline bool
+	var deadline ktime.Time
+	if dl := s.SendTimeout(); dl > 0 {
+		deadline = t.Kernel().MonotonicClock().Now().Add(time.Duration(dl) * time.Nanosecond)
+		haveDeadline = true
+	} else if dl < 0 {
+		flags |= linux.MSG_DONTWAIT
+	}
+
 	// Call the syscall implementation.
-	n, e := s.SendMsg(t, src, to, int(flags), socket.ControlMessages{Unix: controlMessages})
+	n, e := s.SendMsg(t, src, to, int(flags), haveDeadline, deadline, socket.ControlMessages{Unix: controlMessages})
 	err = handleIOError(t, n != 0, e.ToError(), kernel.ERESTARTSYS, "sendmsg", file)
 	if err != nil {
 		controlMessages.Release()
@@ -1052,8 +1065,17 @@ func sendTo(t *kernel.Task, fd kdefs.FD, bufPtr usermem.Addr, bufLen uint64, fla
 		return 0, err
 	}
 
+	var haveDeadline bool
+	var deadline ktime.Time
+	if dl := s.SendTimeout(); dl > 0 {
+		deadline = t.Kernel().MonotonicClock().Now().Add(time.Duration(dl) * time.Nanosecond)
+		haveDeadline = true
+	} else if dl < 0 {
+		flags |= linux.MSG_DONTWAIT
+	}
+
 	// Call the syscall implementation.
-	n, e := s.SendMsg(t, src, to, int(flags), socket.ControlMessages{Unix: control.New(t, s, nil)})
+	n, e := s.SendMsg(t, src, to, int(flags), haveDeadline, deadline, socket.ControlMessages{Unix: control.New(t, s, nil)})
 	return uintptr(n), handleIOError(t, n != 0, e.ToError(), kernel.ERESTARTSYS, "sendto", file)
 }