[netstack] Decouple tcpip.ControlMessages from the IP control messges.

tcpip.ControlMessages can not contain Linux specific structures which makes it
painful to convert back and forth from Linux to tcpip back to Linux when passing
around control messages in hostinet and raw sockets.

Now we convert to the Linux version of the control message as soon as we are
out of tcpip.

PiperOrigin-RevId: 347027065

2 files changed, 9 insertions, 9 deletions

diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index 87eda2efb..3e116e829 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -1498,7 +1498,7 @@ func (e *endpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-c
 // 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) (int64, tcpip.ControlMessages, *tcpip.Error) {
+func (e *endpoint) Peek(vec [][]byte) (int64, *tcpip.Error) {
 	e.LockUser()
 	defer e.UnlockUser()
 
@@ -1506,10 +1506,10 @@ func (e *endpoint) Peek(vec [][]byte) (int64, tcpip.ControlMessages, *tcpip.Erro
 	// but has some pending unread data.
 	if s := e.EndpointState(); !s.connected() && s != StateClose {
 		if s == StateError {
-			return 0, tcpip.ControlMessages{}, e.hardErrorLocked()
+			return 0, e.hardErrorLocked()
 		}
 		e.stats.ReadErrors.InvalidEndpointState.Increment()
-		return 0, tcpip.ControlMessages{}, tcpip.ErrInvalidEndpointState
+		return 0, tcpip.ErrInvalidEndpointState
 	}
 
 	e.rcvListMu.Lock()
@@ -1518,9 +1518,9 @@ func (e *endpoint) Peek(vec [][]byte) (int64, tcpip.ControlMessages, *tcpip.Erro
 	if e.rcvBufUsed == 0 {
 		if e.rcvClosed || !e.EndpointState().connected() {
 			e.stats.ReadErrors.ReadClosed.Increment()
-			return 0, tcpip.ControlMessages{}, tcpip.ErrClosedForReceive
+			return 0, tcpip.ErrClosedForReceive
 		}
-		return 0, tcpip.ControlMessages{}, tcpip.ErrWouldBlock
+		return 0, tcpip.ErrWouldBlock
 	}
 
 	// Make a copy of vec so we can modify the slide headers.
@@ -1535,7 +1535,7 @@ func (e *endpoint) Peek(vec [][]byte) (int64, tcpip.ControlMessages, *tcpip.Erro
 
 			for len(v) > 0 {
 				if len(vec) == 0 {
-					return num, tcpip.ControlMessages{}, nil
+					return num, nil
 				}
 				if len(vec[0]) == 0 {
 					vec = vec[1:]
@@ -1550,7 +1550,7 @@ func (e *endpoint) Peek(vec [][]byte) (int64, tcpip.ControlMessages, *tcpip.Erro
 		}
 	}
 
-	return num, tcpip.ControlMessages{}, nil
+	return num, nil
 }
 
 // selectWindowLocked returns the new window without checking for shrinking or scaling
diff --git a/pkg/tcpip/transport/tcp/tcp_test.go b/pkg/tcpip/transport/tcp/tcp_test.go
index 1759ebea9..7581bdc97 100644
--- a/pkg/tcpip/transport/tcp/tcp_test.go
+++ b/pkg/tcpip/transport/tcp/tcp_test.go
@@ -4148,7 +4148,7 @@ 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("Peek failed: %s", err)
 	}
@@ -4174,7 +4174,7 @@ func TestReadAfterClosedState(t *testing.T) {
 		t.Fatalf("got c.EP.Read(nil) = %s, want = %s", 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("got c.EP.Peek(...) = %s, want = %s", err, tcpip.ErrClosedForReceive)
 	}
 }