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/****************************************************************************
* fs/vfs/fs_open.c
*
* Copyright (C) 2007-2009, 2011-2012 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 <sys/types.h>
#include <fcntl.h>
#include <sched.h>
#include <errno.h>
#include <assert.h>
#ifdef CONFIG_FILE_MODE
#include <stdarg.h>
#endif
#include <nuttx/fs/fs.h>
#include "inode/inode.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: inode_checkflags
*
* Description:
* Check if the access described by 'oflags' is supported on 'inode'
*
****************************************************************************/
int inode_checkflags(FAR struct inode *inode, int oflags)
{
if (((oflags & O_RDOK) != 0 && !inode->u.i_ops->read) ||
((oflags & O_WROK) != 0 && !inode->u.i_ops->write))
{
return -EACCES;
}
else
{
return OK;
}
}
/****************************************************************************
* Name: open
*
* Description:
* Standard 'open' interface
*
****************************************************************************/
int open(const char *path, int oflags, ...)
{
FAR struct file *filep;
FAR struct inode *inode;
FAR const char *relpath = NULL;
#if defined(CONFIG_FILE_MODE) || !defined(CONFIG_DISABLE_MOUNTPOINT)
mode_t mode = 0666;
#endif
int ret;
int fd;
#ifdef CONFIG_FILE_MODE
# ifdef CONFIG_CPP_HAVE_WARNING
# warning "File creation not implemented"
# endif
/* If the file is opened for creation, then get the mode bits */
if ((oflags & (O_WRONLY|O_CREAT)) != 0)
{
va_list ap;
va_start(ap, oflags);
mode = va_arg(ap, mode_t);
va_end(ap);
}
#endif
/* Get an inode for this file */
inode = inode_find(path, &relpath);
if (!inode)
{
/* "O_CREAT is not set and the named file does not exist. Or, a
* directory component in pathname does not exist or is a dangling
* symbolic link."
*/
ret = ENOENT;
goto errout;
}
/* Verify that the inode is valid and either a "normal" character driver or a
* mountpoint. We specifically exclude block drivers and and "special"
* inodes (semaphores, message queues, shared memory).
*/
#ifndef CONFIG_DISABLE_MOUNTPOINT
if ((!INODE_IS_DRIVER(inode) && !INODE_IS_MOUNTPT(inode)) || !inode->u.i_ops)
#else
if (!INODE_IS_DRIVER(inode) || !inode->u.i_ops)
#endif
{
ret = ENXIO;
goto errout_with_inode;
}
/* Make sure that the inode supports the requested access */
ret = inode_checkflags(inode, oflags);
if (ret < 0)
{
ret = -ret;
goto errout_with_inode;
}
/* Associate the inode with a file structure */
fd = files_allocate(inode, oflags, 0, 0);
if (fd < 0)
{
ret = EMFILE;
goto errout_with_inode;
}
/* Get the file structure corresponding to the file descriptor. */
filep = fs_getfilep(fd);
if (!filep)
{
/* The errno value has already been set */
return ERROR;
}
/* Perform the driver open operation. NOTE that the open method may be
* called many times. The driver/mountpoint logic should handled this
* because it may also be closed that many times.
*/
ret = OK;
if (inode->u.i_ops->open)
{
#ifndef CONFIG_DISABLE_MOUNTPOINT
if (INODE_IS_MOUNTPT(inode))
{
ret = inode->u.i_mops->open(filep, relpath, oflags, mode);
}
else
#endif
{
ret = inode->u.i_ops->open(filep);
}
}
if (ret < 0)
{
ret = -ret;
goto errout_with_fd;
}
return fd;
errout_with_fd:
files_release(fd);
errout_with_inode:
inode_release(inode);
errout:
set_errno(ret);
return ERROR;
}
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