Track and export socket state.

This is necessary for implementing network diagnostic interfaces like
/proc/net/{tcp,udp,unix} and sock_diag(7).

For pass-through endpoints such as hostinet, we obtain the socket
state from the backend. For netstack, we add explicit tracking of TCP
states.

PiperOrigin-RevId: 251934850

1 files changed, 6 insertions, 0 deletions

diff --git a/pkg/sentry/socket/rpcinet/socket.go b/pkg/sentry/socket/rpcinet/socket.go
index 55e0b6665..bf42bdf69 100644
--- a/pkg/sentry/socket/rpcinet/socket.go
+++ b/pkg/sentry/socket/rpcinet/socket.go
@@ -830,6 +830,12 @@ func (s *socketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to []
 	}
 }
 
+// State implements socket.Socket.State.
+func (s *socketOperations) State() uint32 {
+	// TODO(b/127845868): Define a new rpc to query the socket state.
+	return 0
+}
+
 type socketProvider struct {
 	family int
 }