Implement SO_TIMESTAMP

PiperOrigin-RevId: 195047018
Change-Id: I6d99528a00a2125f414e1e51e067205289ec9d3d

6 files changed, 74 insertions, 47 deletions

diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index 5d62589d8..d84171b0c 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -374,7 +374,7 @@ func (e *endpoint) cleanup() {
 }
 
 // Read reads data from the endpoint.
-func (e *endpoint) Read(*tcpip.FullAddress) (buffer.View, *tcpip.Error) {
+func (e *endpoint) Read(*tcpip.FullAddress) (buffer.View, tcpip.ControlMessages, *tcpip.Error) {
 	e.mu.RLock()
 	// The endpoint can be read if it's connected, or if it's already closed
 	// but has some pending unread data. Also note that a RST being received
@@ -383,9 +383,9 @@ func (e *endpoint) Read(*tcpip.FullAddress) (buffer.View, *tcpip.Error) {
 	if s := e.state; s != stateConnected && s != stateClosed && e.rcvBufUsed == 0 {
 		e.mu.RUnlock()
 		if s == stateError {
-			return buffer.View{}, e.hardError
+			return buffer.View{}, tcpip.ControlMessages{}, e.hardError
 		}
-		return buffer.View{}, tcpip.ErrInvalidEndpointState
+		return buffer.View{}, tcpip.ControlMessages{}, tcpip.ErrInvalidEndpointState
 	}
 
 	e.rcvListMu.Lock()
@@ -394,7 +394,7 @@ func (e *endpoint) Read(*tcpip.FullAddress) (buffer.View, *tcpip.Error) {
 
 	e.mu.RUnlock()
 
-	return v, err
+	return v, tcpip.ControlMessages{}, err
 }
 
 func (e *endpoint) readLocked() (buffer.View, *tcpip.Error) {
@@ -498,7 +498,7 @@ func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (uintptr, *tc
 // Peek reads data without consuming it from the endpoint.
 //
 // This method does not block if there is no data pending.
-func (e *endpoint) Peek(vec [][]byte) (uintptr, *tcpip.Error) {
+func (e *endpoint) Peek(vec [][]byte) (uintptr, tcpip.ControlMessages, *tcpip.Error) {
 	e.mu.RLock()
 	defer e.mu.RUnlock()
 
@@ -506,9 +506,9 @@ func (e *endpoint) Peek(vec [][]byte) (uintptr, *tcpip.Error) {
 	// but has some pending unread data.
 	if s := e.state; s != stateConnected && s != stateClosed {
 		if s == stateError {
-			return 0, e.hardError
+			return 0, tcpip.ControlMessages{}, e.hardError
 		}
-		return 0, tcpip.ErrInvalidEndpointState
+		return 0, tcpip.ControlMessages{}, tcpip.ErrInvalidEndpointState
 	}
 
 	e.rcvListMu.Lock()
@@ -516,9 +516,9 @@ func (e *endpoint) Peek(vec [][]byte) (uintptr, *tcpip.Error) {
 
 	if e.rcvBufUsed == 0 {
 		if e.rcvClosed || e.state != stateConnected {
-			return 0, tcpip.ErrClosedForReceive
+			return 0, tcpip.ControlMessages{}, tcpip.ErrClosedForReceive
 		}
-		return 0, tcpip.ErrWouldBlock
+		return 0, tcpip.ControlMessages{}, tcpip.ErrWouldBlock
 	}
 
 	// Make a copy of vec so we can modify the slide headers.
@@ -534,7 +534,7 @@ func (e *endpoint) Peek(vec [][]byte) (uintptr, *tcpip.Error) {
 
 			for len(v) > 0 {
 				if len(vec) == 0 {
-					return num, nil
+					return num, tcpip.ControlMessages{}, nil
 				}
 				if len(vec[0]) == 0 {
 					vec = vec[1:]
@@ -549,7 +549,7 @@ func (e *endpoint) Peek(vec [][]byte) (uintptr, *tcpip.Error) {
 		}
 	}
 
-	return num, nil
+	return num, tcpip.ControlMessages{}, nil
 }
 
 // zeroReceiveWindow checks if the receive window to be announced now would be
diff --git a/pkg/tcpip/transport/tcp/tcp_test.go b/pkg/tcpip/transport/tcp/tcp_test.go
index 118d861ba..3c21a1ec3 100644
--- a/pkg/tcpip/transport/tcp/tcp_test.go
+++ b/pkg/tcpip/transport/tcp/tcp_test.go
@@ -147,7 +147,7 @@ func TestSimpleReceive(t *testing.T) {
 	c.WQ.EventRegister(&we, waiter.EventIn)
 	defer c.WQ.EventUnregister(&we)
 
-	if _, err := c.EP.Read(nil); err != tcpip.ErrWouldBlock {
+	if _, _, err := c.EP.Read(nil); err != tcpip.ErrWouldBlock {
 		t.Fatalf("Unexpected error from Read: %v", err)
 	}
 
@@ -169,7 +169,7 @@ func TestSimpleReceive(t *testing.T) {
 	}
 
 	// Receive data.
-	v, err := c.EP.Read(nil)
+	v, _, err := c.EP.Read(nil)
 	if err != nil {
 		t.Fatalf("Unexpected error from Read: %v", err)
 	}
@@ -199,7 +199,7 @@ func TestOutOfOrderReceive(t *testing.T) {
 	c.WQ.EventRegister(&we, waiter.EventIn)
 	defer c.WQ.EventUnregister(&we)
 
-	if _, err := c.EP.Read(nil); err != tcpip.ErrWouldBlock {
+	if _, _, err := c.EP.Read(nil); err != tcpip.ErrWouldBlock {
 		t.Fatalf("Unexpected error from Read: %v", err)
 	}
 
@@ -226,7 +226,7 @@ func TestOutOfOrderReceive(t *testing.T) {
 
 	// Wait 200ms and check that no data has been received.
 	time.Sleep(200 * time.Millisecond)
-	if _, err := c.EP.Read(nil); err != tcpip.ErrWouldBlock {
+	if _, _, err := c.EP.Read(nil); err != tcpip.ErrWouldBlock {
 		t.Fatalf("Unexpected error from Read: %v", err)
 	}
 
@@ -243,7 +243,7 @@ func TestOutOfOrderReceive(t *testing.T) {
 	// Receive data.
 	read := make([]byte, 0, 6)
 	for len(read) < len(data) {
-		v, err := c.EP.Read(nil)
+		v, _, err := c.EP.Read(nil)
 		if err != nil {
 			if err == tcpip.ErrWouldBlock {
 				// Wait for receive to be notified.
@@ -284,7 +284,7 @@ func TestOutOfOrderFlood(t *testing.T) {
 	opt := tcpip.ReceiveBufferSizeOption(10)
 	c.CreateConnected(789, 30000, &opt)
 
-	if _, err := c.EP.Read(nil); err != tcpip.ErrWouldBlock {
+	if _, _, err := c.EP.Read(nil); err != tcpip.ErrWouldBlock {
 		t.Fatalf("Unexpected error from Read: %v", err)
 	}
 
@@ -361,7 +361,7 @@ func TestRstOnCloseWithUnreadData(t *testing.T) {
 	c.WQ.EventRegister(&we, waiter.EventIn)
 	defer c.WQ.EventUnregister(&we)
 
-	if _, err := c.EP.Read(nil); err != tcpip.ErrWouldBlock {
+	if _, _, err := c.EP.Read(nil); err != tcpip.ErrWouldBlock {
 		t.Fatalf("Unexpected error from Read: %v", err)
 	}
 
@@ -414,7 +414,7 @@ func TestFullWindowReceive(t *testing.T) {
 	c.WQ.EventRegister(&we, waiter.EventIn)
 	defer c.WQ.EventUnregister(&we)
 
-	_, err := c.EP.Read(nil)
+	_, _, err := c.EP.Read(nil)
 	if err != tcpip.ErrWouldBlock {
 		t.Fatalf("Unexpected error from Read: %v", err)
 	}
@@ -449,7 +449,7 @@ func TestFullWindowReceive(t *testing.T) {
 	)
 
 	// Receive data and check it.
-	v, err := c.EP.Read(nil)
+	v, _, err := c.EP.Read(nil)
 	if err != nil {
 		t.Fatalf("Unexpected error from Read: %v", err)
 	}
@@ -487,7 +487,7 @@ func TestNoWindowShrinking(t *testing.T) {
 	c.WQ.EventRegister(&we, waiter.EventIn)
 	defer c.WQ.EventUnregister(&we)
 
-	_, err := c.EP.Read(nil)
+	_, _, err := c.EP.Read(nil)
 	if err != tcpip.ErrWouldBlock {
 		t.Fatalf("Unexpected error from Read: %v", err)
 	}
@@ -551,7 +551,7 @@ func TestNoWindowShrinking(t *testing.T) {
 	// Receive data and check it.
 	read := make([]byte, 0, 10)
 	for len(read) < len(data) {
-		v, err := c.EP.Read(nil)
+		v, _, err := c.EP.Read(nil)
 		if err != nil {
 			t.Fatalf("Unexpected error from Read: %v", err)
 		}
@@ -954,7 +954,7 @@ func TestZeroScaledWindowReceive(t *testing.T) {
 	}
 
 	// Read some data. An ack should be sent in response to that.
-	v, err := c.EP.Read(nil)
+	v, _, err := c.EP.Read(nil)
 	if err != nil {
 		t.Fatalf("Unexpected error from Read: %v", err)
 	}
@@ -1337,7 +1337,7 @@ func TestReceiveOnResetConnection(t *testing.T) {
 
 loop:
 	for {
-		switch _, err := c.EP.Read(nil); err {
+		switch _, _, err := c.EP.Read(nil); err {
 		case nil:
 			t.Fatalf("Unexpected success.")
 		case tcpip.ErrWouldBlock:
@@ -2293,7 +2293,7 @@ func TestReadAfterClosedState(t *testing.T) {
 	c.WQ.EventRegister(&we, waiter.EventIn)
 	defer c.WQ.EventUnregister(&we)
 
-	if _, err := c.EP.Read(nil); err != tcpip.ErrWouldBlock {
+	if _, _, err := c.EP.Read(nil); err != tcpip.ErrWouldBlock {
 		t.Fatalf("Unexpected error from Read: %v", err)
 	}
 
@@ -2345,7 +2345,7 @@ func TestReadAfterClosedState(t *testing.T) {
 
 	// Check that peek works.
 	peekBuf := make([]byte, 10)
-	n, err := c.EP.Peek([][]byte{peekBuf})
+	n, _, err := c.EP.Peek([][]byte{peekBuf})
 	if err != nil {
 		t.Fatalf("Unexpected error from Peek: %v", err)
 	}
@@ -2356,7 +2356,7 @@ func TestReadAfterClosedState(t *testing.T) {
 	}
 
 	// Receive data.
-	v, err := c.EP.Read(nil)
+	v, _, err := c.EP.Read(nil)
 	if err != nil {
 		t.Fatalf("Unexpected error from Read: %v", err)
 	}
@@ -2367,11 +2367,11 @@ func TestReadAfterClosedState(t *testing.T) {
 
 	// Now that we drained the queue, check that functions fail with the
 	// right error code.
-	if _, err := c.EP.Read(nil); err != tcpip.ErrClosedForReceive {
+	if _, _, err := c.EP.Read(nil); err != tcpip.ErrClosedForReceive {
 		t.Fatalf("Unexpected return from Read: got %v, want %v", err, tcpip.ErrClosedForReceive)
 	}
 
-	if _, err := c.EP.Peek([][]byte{peekBuf}); err != tcpip.ErrClosedForReceive {
+	if _, _, err := c.EP.Peek([][]byte{peekBuf}); err != tcpip.ErrClosedForReceive {
 		t.Fatalf("Unexpected return from Peek: got %v, want %v", err, tcpip.ErrClosedForReceive)
 	}
 }
@@ -2479,7 +2479,7 @@ func checkSendBufferSize(t *testing.T, ep tcpip.Endpoint, v int) {
 }
 
 func TestDefaultBufferSizes(t *testing.T) {
-	s := stack.New([]string{ipv4.ProtocolName}, []string{tcp.ProtocolName})
+	s := stack.New(&tcpip.StdClock{}, []string{ipv4.ProtocolName}, []string{tcp.ProtocolName})
 
 	// Check the default values.
 	ep, err := s.NewEndpoint(tcp.ProtocolNumber, ipv4.ProtocolNumber, &waiter.Queue{})
@@ -2525,7 +2525,7 @@ func TestDefaultBufferSizes(t *testing.T) {
 }
 
 func TestMinMaxBufferSizes(t *testing.T) {
-	s := stack.New([]string{ipv4.ProtocolName}, []string{tcp.ProtocolName})
+	s := stack.New(&tcpip.StdClock{}, []string{ipv4.ProtocolName}, []string{tcp.ProtocolName})
 
 	// Check the default values.
 	ep, err := s.NewEndpoint(tcp.ProtocolNumber, ipv4.ProtocolNumber, &waiter.Queue{})
@@ -2575,7 +2575,7 @@ func TestSelfConnect(t *testing.T) {
 	// it checks that if an endpoint binds to say 127.0.0.1:1000 then
 	// connects to 127.0.0.1:1000, then it will be connected to itself, and
 	// is able to send and receive data through the same endpoint.
-	s := stack.New([]string{ipv4.ProtocolName}, []string{tcp.ProtocolName})
+	s := stack.New(&tcpip.StdClock{}, []string{ipv4.ProtocolName}, []string{tcp.ProtocolName})
 
 	id := loopback.New()
 	if testing.Verbose() {
@@ -2637,13 +2637,13 @@ func TestSelfConnect(t *testing.T) {
 	// Read back what was written.
 	wq.EventUnregister(&waitEntry)
 	wq.EventRegister(&waitEntry, waiter.EventIn)
-	rd, err := ep.Read(nil)
+	rd, _, err := ep.Read(nil)
 	if err != nil {
 		if err != tcpip.ErrWouldBlock {
 			t.Fatalf("Read failed: %v", err)
 		}
 		<-notifyCh
-		rd, err = ep.Read(nil)
+		rd, _, err = ep.Read(nil)
 		if err != nil {
 			t.Fatalf("Read failed: %v", err)
 		}
diff --git a/pkg/tcpip/transport/tcp/tcp_timestamp_test.go b/pkg/tcpip/transport/tcp/tcp_timestamp_test.go
index d12081bb7..335262e43 100644
--- a/pkg/tcpip/transport/tcp/tcp_timestamp_test.go
+++ b/pkg/tcpip/transport/tcp/tcp_timestamp_test.go
@@ -95,7 +95,7 @@ func TestTimeStampEnabledConnect(t *testing.T) {
 	// There should be 5 views to read and each of them should
 	// contain the same data.
 	for i := 0; i < 5; i++ {
-		got, err := c.EP.Read(nil)
+		got, _, err := c.EP.Read(nil)
 		if err != nil {
 			t.Fatalf("Unexpected error from Read: %v", err)
 		}
@@ -296,7 +296,7 @@ func TestSegmentDropWhenTimestampMissing(t *testing.T) {
 	}
 
 	// Issue a read and we should data.
-	got, err := c.EP.Read(nil)
+	got, _, err := c.EP.Read(nil)
 	if err != nil {
 		t.Fatalf("Unexpected error from Read: %v", err)
 	}
diff --git a/pkg/tcpip/transport/tcp/testing/context/context.go b/pkg/tcpip/transport/tcp/testing/context/context.go
index 6a402d150..eb928553f 100644
--- a/pkg/tcpip/transport/tcp/testing/context/context.go
+++ b/pkg/tcpip/transport/tcp/testing/context/context.go
@@ -129,7 +129,7 @@ type Context struct {
 // New allocates and initializes a test context containing a new
 // stack and a link-layer endpoint.
 func New(t *testing.T, mtu uint32) *Context {
-	s := stack.New([]string{ipv4.ProtocolName, ipv6.ProtocolName}, []string{tcp.ProtocolName})
+	s := stack.New(&tcpip.StdClock{}, []string{ipv4.ProtocolName, ipv6.ProtocolName}, []string{tcp.ProtocolName})
 
 	// Allow minimum send/receive buffer sizes to be 1 during tests.
 	if err := s.SetTransportProtocolOption(tcp.ProtocolNumber, tcp.SendBufferSizeOption{1, tcp.DefaultBufferSize, tcp.DefaultBufferSize * 10}); err != nil {
diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go
index 80fa88c4c..f86fc6d5a 100644
--- a/pkg/tcpip/transport/udp/endpoint.go
+++ b/pkg/tcpip/transport/udp/endpoint.go
@@ -19,6 +19,8 @@ type udpPacket struct {
 	udpPacketEntry
 	senderAddress tcpip.FullAddress
 	data          buffer.VectorisedView `state:".(buffer.VectorisedView)"`
+	timestamp     int64
+	hasTimestamp  bool
 	// views is used as buffer for data when its length is large
 	// enough to store a VectorisedView.
 	views [8]buffer.View `state:"nosave"`
@@ -52,6 +54,7 @@ type endpoint struct {
 	rcvBufSizeMax int `state:".(int)"`
 	rcvBufSize    int
 	rcvClosed     bool
+	rcvTimestamp  bool
 
 	// The following fields are protected by the mu mutex.
 	mu         sync.RWMutex `state:"nosave"`
@@ -134,7 +137,7 @@ func (e *endpoint) Close() {
 
 // Read reads data from the endpoint. This method does not block if
 // there is no data pending.
-func (e *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, *tcpip.Error) {
+func (e *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, tcpip.ControlMessages, *tcpip.Error) {
 	e.rcvMu.Lock()
 
 	if e.rcvList.Empty() {
@@ -143,12 +146,13 @@ func (e *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, *tcpip.Error) {
 			err = tcpip.ErrClosedForReceive
 		}
 		e.rcvMu.Unlock()
-		return buffer.View{}, err
+		return buffer.View{}, tcpip.ControlMessages{}, err
 	}
 
 	p := e.rcvList.Front()
 	e.rcvList.Remove(p)
 	e.rcvBufSize -= p.data.Size()
+	ts := e.rcvTimestamp
 
 	e.rcvMu.Unlock()
 
@@ -156,7 +160,12 @@ func (e *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, *tcpip.Error) {
 		*addr = p.senderAddress
 	}
 
-	return p.data.ToView(), nil
+	if ts && !p.hasTimestamp {
+		// Linux uses the current time.
+		p.timestamp = e.stack.NowNanoseconds()
+	}
+
+	return p.data.ToView(), tcpip.ControlMessages{HasTimestamp: ts, Timestamp: p.timestamp}, nil
 }
 
 // prepareForWrite prepares the endpoint for sending data. In particular, it
@@ -299,8 +308,8 @@ func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (uintptr, *tc
 }
 
 // Peek only returns data from a single datagram, so do nothing here.
-func (e *endpoint) Peek([][]byte) (uintptr, *tcpip.Error) {
-	return 0, nil
+func (e *endpoint) Peek([][]byte) (uintptr, tcpip.ControlMessages, *tcpip.Error) {
+	return 0, tcpip.ControlMessages{}, nil
 }
 
 // SetSockOpt sets a socket option. Currently not supported.
@@ -322,6 +331,11 @@ func (e *endpoint) SetSockOpt(opt interface{}) *tcpip.Error {
 		}
 
 		e.v6only = v != 0
+
+	case tcpip.TimestampOption:
+		e.rcvMu.Lock()
+		e.rcvTimestamp = v != 0
+		e.rcvMu.Unlock()
 	}
 	return nil
 }
@@ -370,6 +384,14 @@ func (e *endpoint) GetSockOpt(opt interface{}) *tcpip.Error {
 		}
 		e.rcvMu.Unlock()
 		return nil
+
+	case *tcpip.TimestampOption:
+		e.rcvMu.Lock()
+		*o = 0
+		if e.rcvTimestamp {
+			*o = 1
+		}
+		e.rcvMu.Unlock()
 	}
 
 	return tcpip.ErrUnknownProtocolOption
@@ -733,6 +755,11 @@ func (e *endpoint) HandlePacket(r *stack.Route, id stack.TransportEndpointID, vv
 	e.rcvList.PushBack(pkt)
 	e.rcvBufSize += vv.Size()
 
+	if e.rcvTimestamp {
+		pkt.timestamp = e.stack.NowNanoseconds()
+		pkt.hasTimestamp = true
+	}
+
 	e.rcvMu.Unlock()
 
 	// Notify any waiters that there's data to be read now.
diff --git a/pkg/tcpip/transport/udp/udp_test.go b/pkg/tcpip/transport/udp/udp_test.go
index 65c567952..1eb9ecb80 100644
--- a/pkg/tcpip/transport/udp/udp_test.go
+++ b/pkg/tcpip/transport/udp/udp_test.go
@@ -56,7 +56,7 @@ type headers struct {
 }
 
 func newDualTestContext(t *testing.T, mtu uint32) *testContext {
-	s := stack.New([]string{ipv4.ProtocolName, ipv6.ProtocolName}, []string{udp.ProtocolName})
+	s := stack.New(&tcpip.StdClock{}, []string{ipv4.ProtocolName, ipv6.ProtocolName}, []string{udp.ProtocolName})
 
 	id, linkEP := channel.New(256, mtu, "")
 	if testing.Verbose() {
@@ -260,12 +260,12 @@ func testV4Read(c *testContext) {
 	defer c.wq.EventUnregister(&we)
 
 	var addr tcpip.FullAddress
-	v, err := c.ep.Read(&addr)
+	v, _, err := c.ep.Read(&addr)
 	if err == tcpip.ErrWouldBlock {
 		// Wait for data to become available.
 		select {
 		case <-ch:
-			v, err = c.ep.Read(&addr)
+			v, _, err = c.ep.Read(&addr)
 			if err != nil {
 				c.t.Fatalf("Read failed: %v", err)
 			}
@@ -355,12 +355,12 @@ func TestV6ReadOnV6(t *testing.T) {
 	defer c.wq.EventUnregister(&we)
 
 	var addr tcpip.FullAddress
-	v, err := c.ep.Read(&addr)
+	v, _, err := c.ep.Read(&addr)
 	if err == tcpip.ErrWouldBlock {
 		// Wait for data to become available.
 		select {
 		case <-ch:
-			v, err = c.ep.Read(&addr)
+			v, _, err = c.ep.Read(&addr)
 			if err != nil {
 				c.t.Fatalf("Read failed: %v", err)
 			}