incubator-nuttx/fs/vfs/fs_dupfd2.c

133 lines
4.1 KiB
C

/****************************************************************************
* fs/vfs/fs_dupfd2.c
*
* Copyright (C) 2007-2009, 2011-2014, 2017 Gregory Nutt. All rights
* reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <unistd.h>
#include <sched.h>
#include <errno.h>
#include "inode/inode.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define DUP_ISOPEN(filep) (filep->f_inode != NULL)
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: fs_dupfd2 OR dup2
*
* Description:
* Clone a file descriptor to a specific descriptor number. If socket
* descriptors are implemented, then this is called by dup2() for the
* case of file descriptors. If socket descriptors are not implemented,
* then this function IS dup2().
*
* Returned Value:
* fs_dupfd is sometimes an OS internal function and sometimes is a direct
* substitute for dup2(). So it must return an errno value as though it
* were dup2().
*
****************************************************************************/
#ifdef CONFIG_NET
int fs_dupfd2(int fd1, int fd2)
#else
int dup2(int fd1, int fd2)
#endif
{
FAR struct file *filep1;
FAR struct file *filep2 = NULL;
int ret;
/* Get the file structures corresponding to the file descriptors. */
ret = fs_getfilep(fd1, &filep1);
if (ret >= 0)
{
ret = fs_getfilep(fd2, &filep2);
}
if (ret < 0)
{
goto errout;
}
DEBUGASSERT(filep1 != NULL && filep2 != NULL);
/* Verify that fd1 is a valid, open file descriptor */
if (!DUP_ISOPEN(filep1))
{
ret = -EBADF;
goto errout;
}
/* Handle a special case */
if (fd1 == fd2)
{
return fd1;
}
/* Perform the dup2 operation */
ret = file_dup2(filep1, filep2);
if (ret < 0)
{
goto errout;
}
return OK;
errout:
set_errno(-ret);
return ERROR;
}