fix some "implicit declaration" warnings in osmo-nitb
diff --git a/openbsc/include/openbsc/control_if.h b/openbsc/include/openbsc/control_if.h
new file mode 100644
index 0000000..96fbf6b
--- /dev/null
+++ b/openbsc/include/openbsc/control_if.h
@@ -0,0 +1,13 @@
+#ifndef _CONTROL_IF_H
+#define _CONTROL_IF_H
+
+#include <osmocom/core/write_queue.h>
+#include <openbsc/control_cmd.h>
+#include <openbsc/gsm_data.h>
+
+int ctrl_cmd_send(struct osmo_wqueue *queue, struct ctrl_cmd *cmd);
+int ctrl_cmd_handle(struct ctrl_cmd *cmd, void *data);
+int controlif_setup(struct gsm_network *gsmnet, uint16_t port);
+
+#endif /* _CONTROL_IF_H */
+