-extern int logopen(),logclose(),logread(),logioctl(),logselect();
-extern int fdesc_open(), fdesc_read(), fdesc_write(),
- fdesc_ioctl(), fdesc_select();
+extern d_open_t logopen;
+extern d_close_t logclose;
+extern d_read_t logread;
+extern d_ioctl_t logioctl;
+extern d_select_t logselect;
+extern d_open_t fdesc_open;
+extern d_read_t fdesc_read;
+extern d_write_t fdesc_write;
+extern d_ioctl_t fdesc_ioctl;
+extern d_select_t fdesc_select;
+
+#define nullopen (d_open_t *)&nulldev
+#define nullclose (d_close_t *)&nulldev
+#define nullread (d_read_t *)&nulldev
+#define nullwrite (d_write_t *)&nulldev
+#define nullioctl (d_ioctl_t *)&nulldev
+#define nullselect (d_select_t *)&nulldev
+#define nullstop (d_stop_t *)&nulldev
+#define nullreset (d_reset_t *)&nulldev