Add support for a variadic ioctl() function. The ioctl() interface is a non-standard, Unix interface. NuttX has always used the older, three-parameter version. Most contemporary systems now, however, use a variadic form of the ioctl() function. Added an option to insert a shim layer to adapt the three-parameter ioctl() to use the variadic interface form. Internally, the ioctl handling is the same three-parameter logic. The only real complexity to the shim is in how the system calls must be handled.

1 files changed, 34 insertions, 0 deletions

diff --git a/nuttx/include/nuttx/fs/fs.h b/nuttx/include/nuttx/fs/fs.h
index 68d3a3725..1baa91cee 100644
--- a/nuttx/include/nuttx/fs/fs.h
+++ b/nuttx/include/nuttx/fs/fs.h
@@ -624,6 +624,40 @@ int open_blockdriver(FAR const char *pathname, int mountflags,
 int close_blockdriver(FAR struct inode *inode);
 #endif
 
+/* fs/vfs/fs_ioctl.c ********************************************************/
+/****************************************************************************
+ * Name: fs_ioctl
+ *
+ * Description:
+ *   Perform device specific operations.
+ *
+ * Parameters:
+ *   fd       File/socket descriptor of device
+ *   req      The ioctl command
+ *   arg      The argument of the ioctl cmd
+ *
+ * Return:
+ *   >=0 on success (positive non-zero values are cmd-specific)
+ *   -1 on failure withi errno set properly:
+ *
+ *   EBADF
+ *     'fd' is not a valid descriptor.
+ *   EFAULT
+ *     'arg' references an inaccessible memory area.
+ *   EINVAL
+ *     'cmd' or 'arg' is not valid.
+ *   ENOTTY
+ *     'fd' is not associated with a character special device.
+ *   ENOTTY
+ *      The specified request does not apply to the kind of object that the
+ *      descriptor 'fd' references.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_LIBC_IOCTL_VARIADIC
+int fs_ioctl(int fd, int req, unsigned long arg);
+#endif
+
 /* fs_fdopen.c **************************************************************/
 /****************************************************************************
  * Name: fs_fdopen