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.

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

include/sys/ioctl.h

@@ -1,7 +1,7 @@
 /****************************************************************************
  * include/sys/ioctl.h
  *
- *   Copyright (C) 2007, 2008, 2012 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2008, 2012, 2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -55,14 +55,6 @@
  * Pre-Processor Definitions
  ****************************************************************************/
 
-/****************************************************************************
- * Type Definitions
- ****************************************************************************/
-
-/****************************************************************************
- * Public Function Prototypes
- ****************************************************************************/
-
 #undef EXTERN
 #if defined(__cplusplus)
 #define EXTERN extern "C"
@@ -72,9 +64,46 @@ extern "C"
 #define EXTERN extern
 #endif
 
-/* ioctl() is a non-standard UNIX-like API */
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
 
+/****************************************************************************
+ * Name: ioctl/fs_ioctl
+ *
+ * Description:
+ *   Perform device specific operations.
+ *
+ *   ioctl() is a non-standard UNIX-like API
+ *
+ * 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 ioctl(int fd, int req, ...);
+#else
 int ioctl(int fd, int req, unsigned long arg);
+#endif
 
 #undef EXTERN
 #if defined(__cplusplus)

include/sys/syscall.h

@@ -229,7 +229,11 @@
 
 #if CONFIG_NFILE_DESCRIPTORS > 0 || CONFIG_NSOCKET_DESCRIPTORS > 0
 #  define SYS_close                    (__SYS_descriptors+0)
-#  define SYS_ioctl                    (__SYS_descriptors+1)
+#  ifdef CONFIG_LIBC_IOCTL_VARIADIC
+#    define SYS_fs_ioctl               (__SYS_descriptors+1)
+#  else
+#    define SYS_ioctl                  (__SYS_descriptors+1)
+#  endif
 #  define SYS_read                     (__SYS_descriptors+2)
 #  define SYS_write                    (__SYS_descriptors+3)
 #  define SYS_pread                    (__SYS_descriptors+4)