netstack: convert more socket options to {Set,Get}SockOptInt

PiperOrigin-RevId: 270763208

11 files changed, 276 insertions, 239 deletions

diff --git a/pkg/sentry/socket/epsocket/epsocket.go b/pkg/sentry/socket/epsocket/epsocket.go
index 25adca090..3e66f9cbb 100644
--- a/pkg/sentry/socket/epsocket/epsocket.go
+++ b/pkg/sentry/socket/epsocket/epsocket.go
@@ -209,6 +209,10 @@ type commonEndpoint interface {
 	// transport.Endpoint.SetSockOpt.
 	SetSockOpt(interface{}) *tcpip.Error
 
+	// SetSockOptInt implements tcpip.Endpoint.SetSockOptInt and
+	// transport.Endpoint.SetSockOptInt.
+	SetSockOptInt(opt tcpip.SockOpt, v int) *tcpip.Error
+
 	// GetSockOpt implements tcpip.Endpoint.GetSockOpt and
 	// transport.Endpoint.GetSockOpt.
 	GetSockOpt(interface{}) *tcpip.Error
@@ -887,8 +891,8 @@ func getSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, family
 			return nil, syserr.ErrInvalidArgument
 		}
 
-		var size tcpip.SendBufferSizeOption
-		if err := ep.GetSockOpt(&size); err != nil {
+		size, err := ep.GetSockOptInt(tcpip.SendBufferSizeOption)
+		if err != nil {
 			return nil, syserr.TranslateNetstackError(err)
 		}
 
@@ -903,8 +907,8 @@ func getSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, family
 			return nil, syserr.ErrInvalidArgument
 		}
 
-		var size tcpip.ReceiveBufferSizeOption
-		if err := ep.GetSockOpt(&size); err != nil {
+		size, err := ep.GetSockOptInt(tcpip.ReceiveBufferSizeOption)
+		if err != nil {
 			return nil, syserr.TranslateNetstackError(err)
 		}
 
@@ -1275,7 +1279,7 @@ func setSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, name i
 		}
 
 		v := usermem.ByteOrder.Uint32(optVal)
-		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.SendBufferSizeOption(v)))
+		return syserr.TranslateNetstackError(ep.SetSockOptInt(tcpip.SendBufferSizeOption, int(v)))
 
 	case linux.SO_RCVBUF:
 		if len(optVal) < sizeOfInt32 {
@@ -1283,7 +1287,7 @@ func setSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, name i
 		}
 
 		v := usermem.ByteOrder.Uint32(optVal)
-		return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.ReceiveBufferSizeOption(v)))
+		return syserr.TranslateNetstackError(ep.SetSockOptInt(tcpip.ReceiveBufferSizeOption, int(v)))
 
 	case linux.SO_REUSEADDR:
 		if len(optVal) < sizeOfInt32 {
@@ -2317,9 +2321,9 @@ func Ioctl(ctx context.Context, ep commonEndpoint, io usermem.IO, args arch.Sysc
 		return 0, err
 
 	case linux.TIOCOUTQ:
-		var v tcpip.SendQueueSizeOption
-		if err := ep.GetSockOpt(&v); err != nil {
-			return 0, syserr.TranslateNetstackError(err).ToError()
+		v, terr := ep.GetSockOptInt(tcpip.SendQueueSizeOption)
+		if terr != nil {
+			return 0, syserr.TranslateNetstackError(terr).ToError()
 		}
 
 		if v > math.MaxInt32 {
diff --git a/pkg/sentry/socket/unix/transport/unix.go b/pkg/sentry/socket/unix/transport/unix.go
index 2b0ad6395..1867b3a5c 100644
--- a/pkg/sentry/socket/unix/transport/unix.go
+++ b/pkg/sentry/socket/unix/transport/unix.go
@@ -175,6 +175,10 @@ type Endpoint interface {
 	// types.
 	SetSockOpt(opt interface{}) *tcpip.Error
 
+	// SetSockOptInt sets a socket option for simple cases when a value has
+	// the int type.
+	SetSockOptInt(opt tcpip.SockOpt, v int) *tcpip.Error
+
 	// GetSockOpt gets a socket option. opt should be a pointer to one of the
 	// tcpip.*Option types.
 	GetSockOpt(opt interface{}) *tcpip.Error
@@ -838,6 +842,10 @@ func (e *baseEndpoint) SetSockOpt(opt interface{}) *tcpip.Error {
 	return nil
 }
 
+func (e *baseEndpoint) SetSockOptInt(opt tcpip.SockOpt, v int) *tcpip.Error {
+	return nil
+}
+
 func (e *baseEndpoint) GetSockOptInt(opt tcpip.SockOpt) (int, *tcpip.Error) {
 	switch opt {
 	case tcpip.ReceiveQueueSizeOption:
@@ -853,65 +861,63 @@ func (e *baseEndpoint) GetSockOptInt(opt tcpip.SockOpt) (int, *tcpip.Error) {
 			return -1, tcpip.ErrQueueSizeNotSupported
 		}
 		return v, nil
-	default:
-		return -1, tcpip.ErrUnknownProtocolOption
-	}
-}
-
-// GetSockOpt implements tcpip.Endpoint.GetSockOpt.
-func (e *baseEndpoint) GetSockOpt(opt interface{}) *tcpip.Error {
-	switch o := opt.(type) {
-	case tcpip.ErrorOption:
-		return nil
 
-	case *tcpip.SendQueueSizeOption:
+	case tcpip.SendQueueSizeOption:
 		e.Lock()
 		if !e.Connected() {
 			e.Unlock()
-			return tcpip.ErrNotConnected
+			return -1, tcpip.ErrNotConnected
 		}
-		qs := tcpip.SendQueueSizeOption(e.connected.SendQueuedSize())
+		v := e.connected.SendQueuedSize()
 		e.Unlock()
-		if qs < 0 {
-			return tcpip.ErrQueueSizeNotSupported
-		}
-		*o = qs
-		return nil
-
-	case *tcpip.PasscredOption:
-		if e.Passcred() {
-			*o = tcpip.PasscredOption(1)
-		} else {
-			*o = tcpip.PasscredOption(0)
+		if v < 0 {
+			return -1, tcpip.ErrQueueSizeNotSupported
 		}
-		return nil
+		return int(v), nil
 
-	case *tcpip.SendBufferSizeOption:
+	case tcpip.SendBufferSizeOption:
 		e.Lock()
 		if !e.Connected() {
 			e.Unlock()
-			return tcpip.ErrNotConnected
+			return -1, tcpip.ErrNotConnected
 		}
-		qs := tcpip.SendBufferSizeOption(e.connected.SendMaxQueueSize())
+		v := e.connected.SendMaxQueueSize()
 		e.Unlock()
-		if qs < 0 {
-			return tcpip.ErrQueueSizeNotSupported
+		if v < 0 {
+			return -1, tcpip.ErrQueueSizeNotSupported
 		}
-		*o = qs
-		return nil
+		return int(v), nil
 
-	case *tcpip.ReceiveBufferSizeOption:
+	case tcpip.ReceiveBufferSizeOption:
 		e.Lock()
 		if e.receiver == nil {
 			e.Unlock()
-			return tcpip.ErrNotConnected
+			return -1, tcpip.ErrNotConnected
 		}
-		qs := tcpip.ReceiveBufferSizeOption(e.receiver.RecvMaxQueueSize())
+		v := e.receiver.RecvMaxQueueSize()
 		e.Unlock()
-		if qs < 0 {
-			return tcpip.ErrQueueSizeNotSupported
+		if v < 0 {
+			return -1, tcpip.ErrQueueSizeNotSupported
+		}
+		return int(v), nil
+
+	default:
+		return -1, tcpip.ErrUnknownProtocolOption
+	}
+}
+
+// GetSockOpt implements tcpip.Endpoint.GetSockOpt.
+func (e *baseEndpoint) GetSockOpt(opt interface{}) *tcpip.Error {
+	switch o := opt.(type) {
+	case tcpip.ErrorOption:
+		return nil
+
+	case *tcpip.PasscredOption:
+		if e.Passcred() {
+			*o = tcpip.PasscredOption(1)
+		} else {
+			*o = tcpip.PasscredOption(0)
 		}
-		*o = qs
 		return nil
 
 	case *tcpip.KeepaliveEnabledOption:
diff --git a/pkg/tcpip/stack/transport_test.go b/pkg/tcpip/stack/transport_test.go
index 847d02982..0e69ac7c8 100644
--- a/pkg/tcpip/stack/transport_test.go
+++ b/pkg/tcpip/stack/transport_test.go
@@ -91,6 +91,11 @@ func (*fakeTransportEndpoint) SetSockOpt(interface{}) *tcpip.Error {
 	return tcpip.ErrInvalidEndpointState
 }
 
+// SetSockOptInt sets a socket option. Currently not supported.
+func (*fakeTransportEndpoint) SetSockOptInt(tcpip.SockOpt, int) *tcpip.Error {
+	return tcpip.ErrInvalidEndpointState
+}
+
 // GetSockOptInt implements tcpip.Endpoint.GetSockOptInt.
 func (*fakeTransportEndpoint) GetSockOptInt(opt tcpip.SockOpt) (int, *tcpip.Error) {
 	return -1, tcpip.ErrUnknownProtocolOption
diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go
index 2534069ab..c021c67ac 100644
--- a/pkg/tcpip/tcpip.go
+++ b/pkg/tcpip/tcpip.go
@@ -401,6 +401,10 @@ type Endpoint interface {
 	// SetSockOpt sets a socket option. opt should be one of the *Option types.
 	SetSockOpt(opt interface{}) *Error
 
+	// SetSockOptInt sets a socket option, for simple cases where a value
+	// has the int type.
+	SetSockOptInt(opt SockOpt, v int) *Error
+
 	// GetSockOpt gets a socket option. opt should be a pointer to one of the
 	// *Option types.
 	GetSockOpt(opt interface{}) *Error
@@ -446,10 +450,22 @@ type WriteOptions struct {
 type SockOpt int
 
 const (
-	// ReceiveQueueSizeOption is used in GetSockOpt to specify that the number of
-	// unread bytes in the input buffer should be returned.
+	// ReceiveQueueSizeOption is used in GetSockOptInt to specify that the
+	// number of unread bytes in the input buffer should be returned.
 	ReceiveQueueSizeOption SockOpt = iota
 
+	// SendBufferSizeOption is used by SetSockOptInt/GetSockOptInt to
+	// specify the send buffer size option.
+	SendBufferSizeOption
+
+	// ReceiveBufferSizeOption is used by SetSockOptInt/GetSockOptInt to
+	// specify the receive buffer size option.
+	ReceiveBufferSizeOption
+
+	// SendQueueSizeOption is used in GetSockOptInt to specify that the
+	// number of unread bytes in the output buffer should be returned.
+	SendQueueSizeOption
+
 	// TODO(b/137664753): convert all int socket options to be handled via
 	// GetSockOptInt.
 )
@@ -458,18 +474,6 @@ const (
 // the endpoint should be cleared and returned.
 type ErrorOption struct{}
 
-// SendBufferSizeOption is used by SetSockOpt/GetSockOpt to specify the send
-// buffer size option.
-type SendBufferSizeOption int
-
-// ReceiveBufferSizeOption is used by SetSockOpt/GetSockOpt to specify the
-// receive buffer size option.
-type ReceiveBufferSizeOption int
-
-// SendQueueSizeOption is used in GetSockOpt to specify that the number of
-// unread bytes in the output buffer should be returned.
-type SendQueueSizeOption int
-
 // V6OnlyOption is used by SetSockOpt/GetSockOpt to specify whether an IPv6
 // socket is to be restricted to sending and receiving IPv6 packets only.
 type V6OnlyOption int
diff --git a/pkg/tcpip/transport/icmp/endpoint.go b/pkg/tcpip/transport/icmp/endpoint.go
index 3db060384..a111fdb2a 100644
--- a/pkg/tcpip/transport/icmp/endpoint.go
+++ b/pkg/tcpip/transport/icmp/endpoint.go
@@ -319,6 +319,11 @@ func (e *endpoint) SetSockOpt(opt interface{}) *tcpip.Error {
 	return nil
 }
 
+// SetSockOptInt sets a socket option. Currently not supported.
+func (e *endpoint) SetSockOptInt(opt tcpip.SockOpt, v int) *tcpip.Error {
+	return nil
+}
+
 // GetSockOptInt implements tcpip.Endpoint.GetSockOptInt.
 func (e *endpoint) GetSockOptInt(opt tcpip.SockOpt) (int, *tcpip.Error) {
 	switch opt {
@@ -331,6 +336,18 @@ func (e *endpoint) GetSockOptInt(opt tcpip.SockOpt) (int, *tcpip.Error) {
 		}
 		e.rcvMu.Unlock()
 		return v, nil
+	case tcpip.SendBufferSizeOption:
+		e.mu.Lock()
+		v := e.sndBufSize
+		e.mu.Unlock()
+		return v, nil
+
+	case tcpip.ReceiveBufferSizeOption:
+		e.rcvMu.Lock()
+		v := e.rcvBufSizeMax
+		e.rcvMu.Unlock()
+		return v, nil
+
 	}
 	return -1, tcpip.ErrUnknownProtocolOption
 }
@@ -341,18 +358,6 @@ func (e *endpoint) GetSockOpt(opt interface{}) *tcpip.Error {
 	case tcpip.ErrorOption:
 		return nil
 
-	case *tcpip.SendBufferSizeOption:
-		e.mu.Lock()
-		*o = tcpip.SendBufferSizeOption(e.sndBufSize)
-		e.mu.Unlock()
-		return nil
-
-	case *tcpip.ReceiveBufferSizeOption:
-		e.rcvMu.Lock()
-		*o = tcpip.ReceiveBufferSizeOption(e.rcvBufSizeMax)
-		e.rcvMu.Unlock()
-		return nil
-
 	case *tcpip.KeepaliveEnabledOption:
 		*o = 0
 		return nil
diff --git a/pkg/tcpip/transport/raw/endpoint.go b/pkg/tcpip/transport/raw/endpoint.go
index cf1c5c433..a02731a5d 100644
--- a/pkg/tcpip/transport/raw/endpoint.go
+++ b/pkg/tcpip/transport/raw/endpoint.go
@@ -492,6 +492,11 @@ func (ep *endpoint) SetSockOpt(opt interface{}) *tcpip.Error {
 	return tcpip.ErrUnknownProtocolOption
 }
 
+// SetSockOptInt implements tcpip.Endpoint.SetSockOptInt.
+func (ep *endpoint) SetSockOptInt(opt tcpip.SockOpt, v int) *tcpip.Error {
+	return tcpip.ErrUnknownProtocolOption
+}
+
 // GetSockOptInt implements tcpip.Endpoint.GetSockOptInt.
 func (ep *endpoint) GetSockOptInt(opt tcpip.SockOpt) (int, *tcpip.Error) {
 	switch opt {
@@ -504,6 +509,19 @@ func (ep *endpoint) GetSockOptInt(opt tcpip.SockOpt) (int, *tcpip.Error) {
 		}
 		ep.rcvMu.Unlock()
 		return v, nil
+
+	case tcpip.SendBufferSizeOption:
+		ep.mu.Lock()
+		v := ep.sndBufSize
+		ep.mu.Unlock()
+		return v, nil
+
+	case tcpip.ReceiveBufferSizeOption:
+		ep.rcvMu.Lock()
+		v := ep.rcvBufSizeMax
+		ep.rcvMu.Unlock()
+		return v, nil
+
 	}
 
 	return -1, tcpip.ErrUnknownProtocolOption
@@ -515,18 +533,6 @@ func (ep *endpoint) GetSockOpt(opt interface{}) *tcpip.Error {
 	case tcpip.ErrorOption:
 		return nil
 
-	case *tcpip.SendBufferSizeOption:
-		ep.mu.Lock()
-		*o = tcpip.SendBufferSizeOption(ep.sndBufSize)
-		ep.mu.Unlock()
-		return nil
-
-	case *tcpip.ReceiveBufferSizeOption:
-		ep.rcvMu.Lock()
-		*o = tcpip.ReceiveBufferSizeOption(ep.rcvBufSizeMax)
-		ep.rcvMu.Unlock()
-		return nil
-
 	case *tcpip.KeepaliveEnabledOption:
 		*o = 0
 		return nil
diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index dd931f88c..35b489c68 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -952,62 +952,9 @@ func (e *endpoint) zeroReceiveWindow(scale uint8) bool {
 	return ((e.rcvBufSize - e.rcvBufUsed) >> scale) == 0
 }
 
-// SetSockOpt sets a socket option.
-func (e *endpoint) SetSockOpt(opt interface{}) *tcpip.Error {
-	switch v := opt.(type) {
-	case tcpip.DelayOption:
-		if v == 0 {
-			atomic.StoreUint32(&e.delay, 0)
-
-			// Handle delayed data.
-			e.sndWaker.Assert()
-		} else {
-			atomic.StoreUint32(&e.delay, 1)
-		}
-		return nil
-
-	case tcpip.CorkOption:
-		if v == 0 {
-			atomic.StoreUint32(&e.cork, 0)
-
-			// Handle the corked data.
-			e.sndWaker.Assert()
-		} else {
-			atomic.StoreUint32(&e.cork, 1)
-		}
-		return nil
-
-	case tcpip.ReuseAddressOption:
-		e.mu.Lock()
-		e.reuseAddr = v != 0
-		e.mu.Unlock()
-		return nil
-
-	case tcpip.ReusePortOption:
-		e.mu.Lock()
-		e.reusePort = v != 0
-		e.mu.Unlock()
-		return nil
-
-	case tcpip.QuickAckOption:
-		if v == 0 {
-			atomic.StoreUint32(&e.slowAck, 1)
-		} else {
-			atomic.StoreUint32(&e.slowAck, 0)
-		}
-		return nil
-
-	case tcpip.MaxSegOption:
-		userMSS := v
-		if userMSS < header.TCPMinimumMSS || userMSS > header.TCPMaximumMSS {
-			return tcpip.ErrInvalidOptionValue
-		}
-		e.mu.Lock()
-		e.userMSS = int(userMSS)
-		e.mu.Unlock()
-		e.notifyProtocolGoroutine(notifyMSSChanged)
-		return nil
-
+// SetSockOptInt sets a socket option.
+func (e *endpoint) SetSockOptInt(opt tcpip.SockOpt, v int) *tcpip.Error {
+	switch opt {
 	case tcpip.ReceiveBufferSizeOption:
 		// Make sure the receive buffer size is within the min and max
 		// allowed.
@@ -1071,6 +1018,67 @@ func (e *endpoint) SetSockOpt(opt interface{}) *tcpip.Error {
 		e.sndBufMu.Unlock()
 		return nil
 
+	default:
+		return nil
+	}
+}
+
+// SetSockOpt sets a socket option.
+func (e *endpoint) SetSockOpt(opt interface{}) *tcpip.Error {
+	switch v := opt.(type) {
+	case tcpip.DelayOption:
+		if v == 0 {
+			atomic.StoreUint32(&e.delay, 0)
+
+			// Handle delayed data.
+			e.sndWaker.Assert()
+		} else {
+			atomic.StoreUint32(&e.delay, 1)
+		}
+		return nil
+
+	case tcpip.CorkOption:
+		if v == 0 {
+			atomic.StoreUint32(&e.cork, 0)
+
+			// Handle the corked data.
+			e.sndWaker.Assert()
+		} else {
+			atomic.StoreUint32(&e.cork, 1)
+		}
+		return nil
+
+	case tcpip.ReuseAddressOption:
+		e.mu.Lock()
+		e.reuseAddr = v != 0
+		e.mu.Unlock()
+		return nil
+
+	case tcpip.ReusePortOption:
+		e.mu.Lock()
+		e.reusePort = v != 0
+		e.mu.Unlock()
+		return nil
+
+	case tcpip.QuickAckOption:
+		if v == 0 {
+			atomic.StoreUint32(&e.slowAck, 1)
+		} else {
+			atomic.StoreUint32(&e.slowAck, 0)
+		}
+		return nil
+
+	case tcpip.MaxSegOption:
+		userMSS := v
+		if userMSS < header.TCPMinimumMSS || userMSS > header.TCPMaximumMSS {
+			return tcpip.ErrInvalidOptionValue
+		}
+		e.mu.Lock()
+		e.userMSS = int(userMSS)
+		e.mu.Unlock()
+		e.notifyProtocolGoroutine(notifyMSSChanged)
+		return nil
+
 	case tcpip.V6OnlyOption:
 		// We only recognize this option on v6 endpoints.
 		if e.netProto != header.IPv6ProtocolNumber {
@@ -1182,6 +1190,18 @@ func (e *endpoint) GetSockOptInt(opt tcpip.SockOpt) (int, *tcpip.Error) {
 	switch opt {
 	case tcpip.ReceiveQueueSizeOption:
 		return e.readyReceiveSize()
+	case tcpip.SendBufferSizeOption:
+		e.sndBufMu.Lock()
+		v := e.sndBufSize
+		e.sndBufMu.Unlock()
+		return v, nil
+
+	case tcpip.ReceiveBufferSizeOption:
+		e.rcvListMu.Lock()
+		v := e.rcvBufSize
+		e.rcvListMu.Unlock()
+		return v, nil
+
 	}
 	return -1, tcpip.ErrUnknownProtocolOption
 }
@@ -1204,18 +1224,6 @@ func (e *endpoint) GetSockOpt(opt interface{}) *tcpip.Error {
 		*o = header.TCPDefaultMSS
 		return nil
 
-	case *tcpip.SendBufferSizeOption:
-		e.sndBufMu.Lock()
-		*o = tcpip.SendBufferSizeOption(e.sndBufSize)
-		e.sndBufMu.Unlock()
-		return nil
-
-	case *tcpip.ReceiveBufferSizeOption:
-		e.rcvListMu.Lock()
-		*o = tcpip.ReceiveBufferSizeOption(e.rcvBufSize)
-		e.rcvListMu.Unlock()
-		return nil
-
 	case *tcpip.DelayOption:
 		*o = 0
 		if v := atomic.LoadUint32(&e.delay); v != 0 {
diff --git a/pkg/tcpip/transport/tcp/tcp_noracedetector_test.go b/pkg/tcpip/transport/tcp/tcp_noracedetector_test.go
index 272bbcdbd..9fa97528b 100644
--- a/pkg/tcpip/transport/tcp/tcp_noracedetector_test.go
+++ b/pkg/tcpip/transport/tcp/tcp_noracedetector_test.go
@@ -38,7 +38,7 @@ func TestFastRecovery(t *testing.T) {
 	c := context.New(t, uint32(header.TCPMinimumSize+header.IPv4MinimumSize+maxPayload))
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	const iterations = 7
 	data := buffer.NewView(2 * maxPayload * (tcp.InitialCwnd << (iterations + 1)))
@@ -190,7 +190,7 @@ func TestExponentialIncreaseDuringSlowStart(t *testing.T) {
 	c := context.New(t, uint32(header.TCPMinimumSize+header.IPv4MinimumSize+maxPayload))
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	const iterations = 7
 	data := buffer.NewView(maxPayload * (tcp.InitialCwnd << (iterations + 1)))
@@ -232,7 +232,7 @@ func TestCongestionAvoidance(t *testing.T) {
 	c := context.New(t, uint32(header.TCPMinimumSize+header.IPv4MinimumSize+maxPayload))
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	const iterations = 7
 	data := buffer.NewView(2 * maxPayload * (tcp.InitialCwnd << (iterations + 1)))
@@ -336,7 +336,7 @@ func TestCubicCongestionAvoidance(t *testing.T) {
 
 	enableCUBIC(t, c)
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	const iterations = 7
 	data := buffer.NewView(2 * maxPayload * (tcp.InitialCwnd << (iterations + 1)))
@@ -445,7 +445,7 @@ func TestRetransmit(t *testing.T) {
 	c := context.New(t, uint32(header.TCPMinimumSize+header.IPv4MinimumSize+maxPayload))
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	const iterations = 7
 	data := buffer.NewView(maxPayload * (tcp.InitialCwnd << (iterations + 1)))
diff --git a/pkg/tcpip/transport/tcp/tcp_test.go b/pkg/tcpip/transport/tcp/tcp_test.go
index 32bb45224..7fa5cfb6e 100644
--- a/pkg/tcpip/transport/tcp/tcp_test.go
+++ b/pkg/tcpip/transport/tcp/tcp_test.go
@@ -84,7 +84,7 @@ func TestConnectIncrementActiveConnection(t *testing.T) {
 	stats := c.Stack().Stats()
 	want := stats.TCP.ActiveConnectionOpenings.Value() + 1
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 	if got := stats.TCP.ActiveConnectionOpenings.Value(); got != want {
 		t.Errorf("got stats.TCP.ActtiveConnectionOpenings.Value() = %v, want = %v", got, want)
 	}
@@ -97,7 +97,7 @@ func TestConnectDoesNotIncrementFailedConnectionAttempts(t *testing.T) {
 	stats := c.Stack().Stats()
 	want := stats.TCP.FailedConnectionAttempts.Value()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 	if got := stats.TCP.FailedConnectionAttempts.Value(); got != want {
 		t.Errorf("got stats.TCP.FailedConnectionOpenings.Value() = %v, want = %v", got, want)
 	}
@@ -131,7 +131,7 @@ func TestTCPSegmentsSentIncrement(t *testing.T) {
 	stats := c.Stack().Stats()
 	// SYN and ACK
 	want := stats.TCP.SegmentsSent.Value() + 2
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	if got := stats.TCP.SegmentsSent.Value(); got != want {
 		t.Errorf("got stats.TCP.SegmentsSent.Value() = %v, want = %v", got, want)
@@ -299,7 +299,7 @@ func TestTCPResetsReceivedIncrement(t *testing.T) {
 	want := stats.TCP.ResetsReceived.Value() + 1
 	iss := seqnum.Value(789)
 	rcvWnd := seqnum.Size(30000)
-	c.CreateConnected(iss, rcvWnd, nil)
+	c.CreateConnected(iss, rcvWnd, -1 /* epRcvBuf */)
 
 	c.SendPacket(nil, &context.Headers{
 		SrcPort: context.TestPort,
@@ -323,7 +323,7 @@ func TestTCPResetsDoNotGenerateResets(t *testing.T) {
 	want := stats.TCP.ResetsReceived.Value() + 1
 	iss := seqnum.Value(789)
 	rcvWnd := seqnum.Size(30000)
-	c.CreateConnected(iss, rcvWnd, nil)
+	c.CreateConnected(iss, rcvWnd, -1 /* epRcvBuf */)
 
 	c.SendPacket(nil, &context.Headers{
 		SrcPort: context.TestPort,
@@ -344,14 +344,14 @@ func TestActiveHandshake(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 }
 
 func TestNonBlockingClose(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 	ep := c.EP
 	c.EP = nil
 
@@ -367,7 +367,7 @@ func TestConnectResetAfterClose(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 	ep := c.EP
 	c.EP = nil
 
@@ -417,7 +417,7 @@ func TestSimpleReceive(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	we, ch := waiter.NewChannelEntry(nil)
 	c.WQ.EventRegister(&we, waiter.EventIn)
@@ -469,7 +469,7 @@ func TestOutOfOrderReceive(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	we, ch := waiter.NewChannelEntry(nil)
 	c.WQ.EventRegister(&we, waiter.EventIn)
@@ -557,8 +557,7 @@ func TestOutOfOrderFlood(t *testing.T) {
 	defer c.Cleanup()
 
 	// Create a new connection with initial window size of 10.
-	opt := tcpip.ReceiveBufferSizeOption(10)
-	c.CreateConnected(789, 30000, &opt)
+	c.CreateConnected(789, 30000, 10)
 
 	if _, _, err := c.EP.Read(nil); err != tcpip.ErrWouldBlock {
 		t.Fatalf("got c.EP.Read(nil) = %v, want = %v", err, tcpip.ErrWouldBlock)
@@ -631,7 +630,7 @@ func TestRstOnCloseWithUnreadData(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	we, ch := waiter.NewChannelEntry(nil)
 	c.WQ.EventRegister(&we, waiter.EventIn)
@@ -700,7 +699,7 @@ func TestRstOnCloseWithUnreadDataFinConvertRst(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	we, ch := waiter.NewChannelEntry(nil)
 	c.WQ.EventRegister(&we, waiter.EventIn)
@@ -785,7 +784,7 @@ func TestShutdownRead(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	if _, _, err := c.EP.Read(nil); err != tcpip.ErrWouldBlock {
 		t.Fatalf("got c.EP.Read(nil) = %v, want = %v", err, tcpip.ErrWouldBlock)
@@ -804,8 +803,7 @@ func TestFullWindowReceive(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	opt := tcpip.ReceiveBufferSizeOption(10)
-	c.CreateConnected(789, 30000, &opt)
+	c.CreateConnected(789, 30000, 10)
 
 	we, ch := waiter.NewChannelEntry(nil)
 	c.WQ.EventRegister(&we, waiter.EventIn)
@@ -872,11 +870,9 @@ func TestNoWindowShrinking(t *testing.T) {
 	defer c.Cleanup()
 
 	// Start off with a window size of 10, then shrink it to 5.
-	opt := tcpip.ReceiveBufferSizeOption(10)
-	c.CreateConnected(789, 30000, &opt)
+	c.CreateConnected(789, 30000, 10)
 
-	opt = 5
-	if err := c.EP.SetSockOpt(opt); err != nil {
+	if err := c.EP.SetSockOptInt(tcpip.ReceiveBufferSizeOption, 5); err != nil {
 		t.Fatalf("SetSockOpt failed: %v", err)
 	}
 
@@ -976,7 +972,7 @@ func TestSimpleSend(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	data := []byte{1, 2, 3}
 	view := buffer.NewView(len(data))
@@ -1017,7 +1013,7 @@ func TestZeroWindowSend(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 0, nil)
+	c.CreateConnected(789, 0, -1 /* epRcvBuf */)
 
 	data := []byte{1, 2, 3}
 	view := buffer.NewView(len(data))
@@ -1075,8 +1071,7 @@ func TestScaledWindowConnect(t *testing.T) {
 	defer c.Cleanup()
 
 	// Set the window size greater than the maximum non-scaled window.
-	opt := tcpip.ReceiveBufferSizeOption(65535 * 3)
-	c.CreateConnectedWithRawOptions(789, 30000, &opt, []byte{
+	c.CreateConnectedWithRawOptions(789, 30000, 65535*3, []byte{
 		header.TCPOptionWS, 3, 0, header.TCPOptionNOP,
 	})
 
@@ -1110,8 +1105,7 @@ func TestNonScaledWindowConnect(t *testing.T) {
 	defer c.Cleanup()
 
 	// Set the window size greater than the maximum non-scaled window.
-	opt := tcpip.ReceiveBufferSizeOption(65535 * 3)
-	c.CreateConnected(789, 30000, &opt)
+	c.CreateConnected(789, 30000, 65535*3)
 
 	data := []byte{1, 2, 3}
 	view := buffer.NewView(len(data))
@@ -1151,7 +1145,7 @@ func TestScaledWindowAccept(t *testing.T) {
 	defer ep.Close()
 
 	// Set the window size greater than the maximum non-scaled window.
-	if err := ep.SetSockOpt(tcpip.ReceiveBufferSizeOption(65535 * 3)); err != nil {
+	if err := ep.SetSockOptInt(tcpip.ReceiveBufferSizeOption, 65535*3); err != nil {
 		t.Fatalf("SetSockOpt failed failed: %v", err)
 	}
 
@@ -1224,7 +1218,7 @@ func TestNonScaledWindowAccept(t *testing.T) {
 	defer ep.Close()
 
 	// Set the window size greater than the maximum non-scaled window.
-	if err := ep.SetSockOpt(tcpip.ReceiveBufferSizeOption(65535 * 3)); err != nil {
+	if err := ep.SetSockOptInt(tcpip.ReceiveBufferSizeOption, 65535*3); err != nil {
 		t.Fatalf("SetSockOpt failed failed: %v", err)
 	}
 
@@ -1293,8 +1287,7 @@ func TestZeroScaledWindowReceive(t *testing.T) {
 	// Set the window size such that a window scale of 4 will be used.
 	const wnd = 65535 * 10
 	const ws = uint32(4)
-	opt := tcpip.ReceiveBufferSizeOption(wnd)
-	c.CreateConnectedWithRawOptions(789, 30000, &opt, []byte{
+	c.CreateConnectedWithRawOptions(789, 30000, wnd, []byte{
 		header.TCPOptionWS, 3, 0, header.TCPOptionNOP,
 	})
 
@@ -1399,7 +1392,7 @@ func TestSegmentMerging(t *testing.T) {
 			c := context.New(t, defaultMTU)
 			defer c.Cleanup()
 
-			c.CreateConnected(789, 30000, nil)
+			c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 			// Prevent the endpoint from processing packets.
 			test.stop(c.EP)
@@ -1449,7 +1442,7 @@ func TestDelay(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	c.EP.SetSockOpt(tcpip.DelayOption(1))
 
@@ -1497,7 +1490,7 @@ func TestUndelay(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	c.EP.SetSockOpt(tcpip.DelayOption(1))
 
@@ -1579,7 +1572,7 @@ func TestMSSNotDelayed(t *testing.T) {
 			c := context.New(t, defaultMTU)
 			defer c.Cleanup()
 
-			c.CreateConnectedWithRawOptions(789, 30000, nil, []byte{
+			c.CreateConnectedWithRawOptions(789, 30000, -1 /* epRcvBuf */, []byte{
 				header.TCPOptionMSS, 4, byte(maxPayload / 256), byte(maxPayload % 256),
 			})
 
@@ -1695,7 +1688,7 @@ func TestSendGreaterThanMTU(t *testing.T) {
 	c := context.New(t, uint32(header.TCPMinimumSize+header.IPv4MinimumSize+maxPayload))
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 	testBrokenUpWrite(t, c, maxPayload)
 }
 
@@ -1704,7 +1697,7 @@ func TestActiveSendMSSLessThanMTU(t *testing.T) {
 	c := context.New(t, 65535)
 	defer c.Cleanup()
 
-	c.CreateConnectedWithRawOptions(789, 30000, nil, []byte{
+	c.CreateConnectedWithRawOptions(789, 30000, -1 /* epRcvBuf */, []byte{
 		header.TCPOptionMSS, 4, byte(maxPayload / 256), byte(maxPayload % 256),
 	})
 	testBrokenUpWrite(t, c, maxPayload)
@@ -1727,7 +1720,7 @@ func TestPassiveSendMSSLessThanMTU(t *testing.T) {
 	// Set the buffer size to a deterministic size so that we can check the
 	// window scaling option.
 	const rcvBufferSize = 0x20000
-	if err := ep.SetSockOpt(tcpip.ReceiveBufferSizeOption(rcvBufferSize)); err != nil {
+	if err := ep.SetSockOptInt(tcpip.ReceiveBufferSizeOption, rcvBufferSize); err != nil {
 		t.Fatalf("SetSockOpt failed failed: %v", err)
 	}
 
@@ -1871,7 +1864,7 @@ func TestSynOptionsOnActiveConnect(t *testing.T) {
 	// window scaling option.
 	const rcvBufferSize = 0x20000
 	const wndScale = 2
-	if err := c.EP.SetSockOpt(tcpip.ReceiveBufferSizeOption(rcvBufferSize)); err != nil {
+	if err := c.EP.SetSockOptInt(tcpip.ReceiveBufferSizeOption, rcvBufferSize); err != nil {
 		t.Fatalf("SetSockOpt failed failed: %v", err)
 	}
 
@@ -1973,7 +1966,7 @@ func TestReceiveOnResetConnection(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	// Send RST segment.
 	c.SendPacket(nil, &context.Headers{
@@ -2010,7 +2003,7 @@ func TestSendOnResetConnection(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	// Send RST segment.
 	c.SendPacket(nil, &context.Headers{
@@ -2035,7 +2028,7 @@ func TestFinImmediately(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	// Shutdown immediately, check that we get a FIN.
 	if err := c.EP.Shutdown(tcpip.ShutdownWrite); err != nil {
@@ -2078,7 +2071,7 @@ func TestFinRetransmit(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	// Shutdown immediately, check that we get a FIN.
 	if err := c.EP.Shutdown(tcpip.ShutdownWrite); err != nil {
@@ -2132,7 +2125,7 @@ func TestFinWithNoPendingData(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	// Write something out, and have it acknowledged.
 	view := buffer.NewView(10)
@@ -2203,7 +2196,7 @@ func TestFinWithPendingDataCwndFull(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	// Write enough segments to fill the congestion window before ACK'ing
 	// any of them.
@@ -2291,7 +2284,7 @@ func TestFinWithPendingData(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	// Write something out, and acknowledge it to get cwnd to 2.
 	view := buffer.NewView(10)
@@ -2377,7 +2370,7 @@ func TestFinWithPartialAck(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	// Write something out, and acknowledge it to get cwnd to 2. Also send
 	// FIN from the test side.
@@ -2509,7 +2502,7 @@ func scaledSendWindow(t *testing.T, scale uint8) {
 	defer c.Cleanup()
 
 	maxPayload := defaultMTU - header.IPv4MinimumSize - header.TCPMinimumSize
-	c.CreateConnectedWithRawOptions(789, 0, nil, []byte{
+	c.CreateConnectedWithRawOptions(789, 0, -1 /* epRcvBuf */, []byte{
 		header.TCPOptionMSS, 4, byte(maxPayload / 256), byte(maxPayload % 256),
 		header.TCPOptionWS, 3, scale, header.TCPOptionNOP,
 	})
@@ -2559,7 +2552,7 @@ func TestScaledSendWindow(t *testing.T) {
 func TestReceivedValidSegmentCountIncrement(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 	stats := c.Stack().Stats()
 	want := stats.TCP.ValidSegmentsReceived.Value() + 1
 
@@ -2580,7 +2573,7 @@ func TestReceivedValidSegmentCountIncrement(t *testing.T) {
 func TestReceivedInvalidSegmentCountIncrement(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 	stats := c.Stack().Stats()
 	want := stats.TCP.InvalidSegmentsReceived.Value() + 1
 	vv := c.BuildSegment(nil, &context.Headers{
@@ -2604,7 +2597,7 @@ func TestReceivedInvalidSegmentCountIncrement(t *testing.T) {
 func TestReceivedIncorrectChecksumIncrement(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 	stats := c.Stack().Stats()
 	want := stats.TCP.ChecksumErrors.Value() + 1
 	vv := c.BuildSegment([]byte{0x1, 0x2, 0x3}, &context.Headers{
@@ -2635,7 +2628,7 @@ func TestReceivedSegmentQueuing(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	// Send 200 segments.
 	data := []byte{1, 2, 3}
@@ -2681,7 +2674,7 @@ func TestReadAfterClosedState(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	we, ch := waiter.NewChannelEntry(nil)
 	c.WQ.EventRegister(&we, waiter.EventIn)
@@ -2856,8 +2849,8 @@ func TestReusePort(t *testing.T) {
 func checkRecvBufferSize(t *testing.T, ep tcpip.Endpoint, v int) {
 	t.Helper()
 
-	var s tcpip.ReceiveBufferSizeOption
-	if err := ep.GetSockOpt(&s); err != nil {
+	s, err := ep.GetSockOptInt(tcpip.ReceiveBufferSizeOption)
+	if err != nil {
 		t.Fatalf("GetSockOpt failed: %v", err)
 	}
 
@@ -2869,8 +2862,8 @@ func checkRecvBufferSize(t *testing.T, ep tcpip.Endpoint, v int) {
 func checkSendBufferSize(t *testing.T, ep tcpip.Endpoint, v int) {
 	t.Helper()
 
-	var s tcpip.SendBufferSizeOption
-	if err := ep.GetSockOpt(&s); err != nil {
+	s, err := ep.GetSockOptInt(tcpip.SendBufferSizeOption)
+	if err != nil {
 		t.Fatalf("GetSockOpt failed: %v", err)
 	}
 
@@ -2945,26 +2938,26 @@ func TestMinMaxBufferSizes(t *testing.T) {
 	}
 
 	// Set values below the min.
-	if err := ep.SetSockOpt(tcpip.ReceiveBufferSizeOption(199)); err != nil {
+	if err := ep.SetSockOptInt(tcpip.ReceiveBufferSizeOption, 199); err != nil {
 		t.Fatalf("GetSockOpt failed: %v", err)
 	}
 
 	checkRecvBufferSize(t, ep, 200)
 
-	if err := ep.SetSockOpt(tcpip.SendBufferSizeOption(299)); err != nil {
+	if err := ep.SetSockOptInt(tcpip.SendBufferSizeOption, 299); err != nil {
 		t.Fatalf("GetSockOpt failed: %v", err)
 	}
 
 	checkSendBufferSize(t, ep, 300)
 
 	// Set values above the max.
-	if err := ep.SetSockOpt(tcpip.ReceiveBufferSizeOption(1 + tcp.DefaultReceiveBufferSize*20)); err != nil {
+	if err := ep.SetSockOptInt(tcpip.ReceiveBufferSizeOption, 1+tcp.DefaultReceiveBufferSize*20); err != nil {
 		t.Fatalf("GetSockOpt failed: %v", err)
 	}
 
 	checkRecvBufferSize(t, ep, tcp.DefaultReceiveBufferSize*20)
 
-	if err := ep.SetSockOpt(tcpip.SendBufferSizeOption(1 + tcp.DefaultSendBufferSize*30)); err != nil {
+	if err := ep.SetSockOptInt(tcpip.SendBufferSizeOption, 1+tcp.DefaultSendBufferSize*30); err != nil {
 		t.Fatalf("GetSockOpt failed: %v", err)
 	}
 
@@ -3231,7 +3224,7 @@ func TestPathMTUDiscovery(t *testing.T) {
 
 	// Create new connection with MSS of 1460.
 	const maxPayload = 1500 - header.TCPMinimumSize - header.IPv4MinimumSize
-	c.CreateConnectedWithRawOptions(789, 30000, nil, []byte{
+	c.CreateConnectedWithRawOptions(789, 30000, -1 /* epRcvBuf */, []byte{
 		header.TCPOptionMSS, 4, byte(maxPayload / 256), byte(maxPayload % 256),
 	})
 
@@ -3308,7 +3301,7 @@ func TestTCPEndpointProbe(t *testing.T) {
 		invoked <- struct{}{}
 	})
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	data := []byte{1, 2, 3}
 	c.SendPacket(data, &context.Headers{
@@ -3482,7 +3475,7 @@ func TestKeepalive(t *testing.T) {
 	c := context.New(t, defaultMTU)
 	defer c.Cleanup()
 
-	c.CreateConnected(789, 30000, nil)
+	c.CreateConnected(789, 30000, -1 /* epRcvBuf */)
 
 	c.EP.SetSockOpt(tcpip.KeepaliveIdleOption(10 * time.Millisecond))
 	c.EP.SetSockOpt(tcpip.KeepaliveIntervalOption(10 * time.Millisecond))
diff --git a/pkg/tcpip/transport/tcp/testing/context/context.go b/pkg/tcpip/transport/tcp/testing/context/context.go
index 16783e716..78eff5c3a 100644
--- a/pkg/tcpip/transport/tcp/testing/context/context.go
+++ b/pkg/tcpip/transport/tcp/testing/context/context.go
@@ -512,7 +512,7 @@ func (c *Context) SendV6Packet(payload []byte, h *Headers) {
 }
 
 // CreateConnected creates a connected TCP endpoint.
-func (c *Context) CreateConnected(iss seqnum.Value, rcvWnd seqnum.Size, epRcvBuf *tcpip.ReceiveBufferSizeOption) {
+func (c *Context) CreateConnected(iss seqnum.Value, rcvWnd seqnum.Size, epRcvBuf int) {
 	c.CreateConnectedWithRawOptions(iss, rcvWnd, epRcvBuf, nil)
 }
 
@@ -590,7 +590,7 @@ func (c *Context) Connect(iss seqnum.Value, rcvWnd seqnum.Size, options []byte)
 //
 // It also sets the receive buffer for the endpoint to the specified
 // value in epRcvBuf.
-func (c *Context) CreateConnectedWithRawOptions(iss seqnum.Value, rcvWnd seqnum.Size, epRcvBuf *tcpip.ReceiveBufferSizeOption, options []byte) {
+func (c *Context) CreateConnectedWithRawOptions(iss seqnum.Value, rcvWnd seqnum.Size, epRcvBuf int, options []byte) {
 	// Create TCP endpoint.
 	var err *tcpip.Error
 	c.EP, err = c.s.NewEndpoint(tcp.ProtocolNumber, ipv4.ProtocolNumber, &c.WQ)
@@ -598,8 +598,8 @@ func (c *Context) CreateConnectedWithRawOptions(iss seqnum.Value, rcvWnd seqnum.
 		c.t.Fatalf("NewEndpoint failed: %v", err)
 	}
 
-	if epRcvBuf != nil {
-		if err := c.EP.SetSockOpt(*epRcvBuf); err != nil {
+	if epRcvBuf != -1 {
+		if err := c.EP.SetSockOptInt(tcpip.ReceiveBufferSizeOption, epRcvBuf); err != nil {
 			c.t.Fatalf("SetSockOpt failed failed: %v", err)
 		}
 	}
diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go
index 6ac7c067a..0bec7e62d 100644
--- a/pkg/tcpip/transport/udp/endpoint.go
+++ b/pkg/tcpip/transport/udp/endpoint.go
@@ -389,7 +389,12 @@ func (e *endpoint) Peek([][]byte) (int64, tcpip.ControlMessages, *tcpip.Error) {
 	return 0, tcpip.ControlMessages{}, nil
 }
 
-// SetSockOpt sets a socket option. Currently not supported.
+// SetSockOptInt implements tcpip.Endpoint.SetSockOptInt.
+func (e *endpoint) SetSockOptInt(opt tcpip.SockOpt, v int) *tcpip.Error {
+	return nil
+}
+
+// SetSockOpt implements tcpip.Endpoint.SetSockOpt.
 func (e *endpoint) SetSockOpt(opt interface{}) *tcpip.Error {
 	switch v := opt.(type) {
 	case tcpip.V6OnlyOption:
@@ -568,7 +573,20 @@ func (e *endpoint) GetSockOptInt(opt tcpip.SockOpt) (int, *tcpip.Error) {
 		}
 		e.rcvMu.Unlock()
 		return v, nil
+
+	case tcpip.SendBufferSizeOption:
+		e.mu.Lock()
+		v := e.sndBufSize
+		e.mu.Unlock()
+		return v, nil
+
+	case tcpip.ReceiveBufferSizeOption:
+		e.rcvMu.Lock()
+		v := e.rcvBufSizeMax
+		e.rcvMu.Unlock()
+		return v, nil
 	}
+
 	return -1, tcpip.ErrUnknownProtocolOption
 }
 
@@ -578,18 +596,6 @@ func (e *endpoint) GetSockOpt(opt interface{}) *tcpip.Error {
 	case tcpip.ErrorOption:
 		return nil
 
-	case *tcpip.SendBufferSizeOption:
-		e.mu.Lock()
-		*o = tcpip.SendBufferSizeOption(e.sndBufSize)
-		e.mu.Unlock()
-		return nil
-
-	case *tcpip.ReceiveBufferSizeOption:
-		e.rcvMu.Lock()
-		*o = tcpip.ReceiveBufferSizeOption(e.rcvBufSizeMax)
-		e.rcvMu.Unlock()
-		return nil
-
 	case *tcpip.V6OnlyOption:
 		// We only recognize this option on v6 endpoints.
 		if e.netProto != header.IPv6ProtocolNumber {