server: Add infrastructure for ioctl server request.
diff --git a/server/signal.c b/server/signal.c
index 11a0179..fb16c2f 100644
--- a/server/signal.c
+++ b/server/signal.c
@@ -84,6 +84,7 @@
     handler_poll_event,       /* poll_event */
     NULL,                     /* flush */
     NULL,                     /* get_fd_type */
+    NULL,                     /* ioctl */
     NULL,                     /* queue_async */
     NULL,                     /* reselect_async */
     NULL                      /* cancel_async */