118 lines
4.3 KiB
C
118 lines
4.3 KiB
C
/****************************************************************************
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* libc/misc/lib_ioctl.c
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*
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* Copyright (C) 2014 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <sys/ioctl.h>
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#include <stdarg.h>
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#include <errno.h>
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#include <assert.h>
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#include <nuttx/fs/fs.h>
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#include "lib_internal.h"
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#if defined(CONFIG_LIBC_IOCTL_VARIADIC) && CONFIG_NFILE_DESCRIPTORS > 0
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: ioctl
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*
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* Description:
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* Perform device specific operations.
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*
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* Parameters:
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* fd File/socket descriptor of device
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* req The ioctl command
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* ... A third argument of type unsigned long is expected
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*
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* Return:
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* >=0 on success (positive non-zero values are cmd-specific)
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* -1 on failure with errno set properly:
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*
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* EBADF
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* 'fd' is not a valid descriptor.
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* EFAULT
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* 'arg' references an inaccessible memory area.
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* EINVAL
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* 'cmd' or 'arg' is not valid.
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* ENOTTY
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* 'fd' is not associated with a character special device.
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* ENOTTY
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* The specified request does not apply to the kind of object that the
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* descriptor 'fd' references.
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*
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****************************************************************************/
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int ioctl(int fd, int req, ...)
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{
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unsigned long arg;
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va_list ap;
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/* Get the unsigned long argument.
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*
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* REVISIT: This could be the cause of the crash down the road if the
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* actual size of the argument is anything other than sizeof(unsigned long).
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* Most small integers will be promoted to 'int'. ARM should pass the
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* following test with all three types having sizeof(type) == 4 bytes.
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* 'float' should also be tested. But 'long long' and 'double' are out of
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* the question! Don't try to pass them.
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*
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* And what will happen if no third argument is passed? In most cases,
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* this should just result in a garbage value for arg. But you may
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* discover cases where something worse happens!
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*/
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DEBUGASSERT(sizeof(int) == sizeof(unsigned long) &&
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sizeof(FAR void *) == sizeof(unsigned long));
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va_start(ap, req);
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arg = va_arg(ap, unsigned long);
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va_end(ap);
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/* Then let fs_ioctl() to the real work */
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return fs_ioctl(fd, req, arg);
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}
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#endif /* CONFIG_LIBC_IOCTL_VARIADIC && CONFIG_NFILE_DESCRIPTORS > 0 */
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