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- /****************************************************************************
- * fs/vfs/fs_open.c
- *
- * Copyright (C) 2007-2009, 2011-2012, 2016-2018 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 <stdbool.h>
- #include <fcntl.h>
- #include <sched.h>
- #include <errno.h>
- #include <assert.h>
- #include <stdarg.h>
- #include <nuttx/cancelpt.h>
- #include <nuttx/fs/fs.h>
- #include "inode/inode.h"
- #include "driver/driver.h"
- /****************************************************************************
- * 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: nx_vopen
- *
- * Description:
- * nx_vopen() is identical to 'nx_open' except that it accepts a va_list
- * as an argument versus taking a variable length list of arguments.
- *
- * nx_vopen() is an internal NuttX interface and should not be called from
- * applications.
- *
- * Returned Value:
- * Zero (OK) is returned on success; a negated errno value is returned on
- * any failure.
- *
- ****************************************************************************/
- int nx_vopen(FAR const char *path, int oflags, va_list ap)
- {
- struct inode_search_s desc;
- FAR struct file *filep;
- FAR struct inode *inode;
- #if defined(CONFIG_FILE_MODE) || !defined(CONFIG_DISABLE_MOUNTPOINT)
- mode_t mode = 0666;
- #endif
- int ret;
- int fd;
- if (path == NULL)
- {
- return -EINVAL;
- }
- #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_start(ap, oflags);
- mode = va_arg(ap, mode_t);
- va_end(ap);
- }
- #endif
- /* Get an inode for this file */
- SETUP_SEARCH(&desc, path, false);
- ret = inode_find(&desc);
- if (ret < 0)
- {
- /* "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."
- */
- goto errout_with_search;
- }
- /* Get the search results */
- inode = desc.node;
- DEBUGASSERT(inode != NULL);
- #if !defined(CONFIG_DISABLE_MOUNTPOINT) && \
- !defined(CONFIG_DISABLE_PSEUDOFS_OPERATIONS)
- /* If the inode is block driver, then we may return a character driver
- * proxy for the block driver. block_proxy() will instantiate a BCH
- * character driver wrapper around the block driver, open(), then
- * unlink() the character driver. On success, block_proxy() will
- * return the file descriptor of the opened character driver.
- *
- * NOTE: This will recurse to open the character driver proxy.
- */
- if (INODE_IS_BLOCK(inode) || INODE_IS_MTD(inode))
- {
- /* Release the inode reference */
- inode_release(inode);
- /* Get the file descriptor of the opened character driver proxy */
- fd = block_proxy(path, oflags);
- if (fd < 0)
- {
- ret = fd;
- goto errout_with_search;
- }
- /* Return the file descriptor */
- RELEASE_SEARCH(&desc);
- return fd;
- }
- else
- #endif
- /* Verify that the inode is either a "normal" character driver or a
- * mountpoint. We specifically "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)
- {
- 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. */
- ret = fs_getfilep(fd, &filep);
- if (ret < 0)
- {
- goto errout_with_inode;
- }
- /* 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, desc.relpath, oflags, mode);
- }
- else
- #endif
- {
- ret = inode->u.i_ops->open(filep);
- }
- }
- if (ret < 0)
- {
- goto errout_with_fd;
- }
- #ifdef CONFIG_PSEUDOTERM_SUSV1
- /* If the return value from the open method is > 0, then it may actually
- * be an encoded file descriptor. This kind of logic is currently only
- * needed for /dev/ptmx: When dev ptmx is opened, it does not return a
- * file descriptor associated with the /dev/ptmx inode, but rather with
- * the inode of master device created by the /dev/ptmx open method.
- *
- * The encoding supports (a) returning file descriptor 0 (which really
- * should not happen), and (b) avoiding confusion if some other open
- * method returns a positive, non-zero value which is not a file
- * descriptor.
- */
- if (OPEN_ISFD(ret))
- {
- /* Release file descriptor and inode that we allocated. We don't
- * need those.
- */
- files_release(fd);
- inode_release(inode);
- /* Instead, decode and return the descriptor associated with the
- * master side device.
- */
- fd = (int)OPEN_GETFD(ret);
- DEBUGASSERT((unsigned)fd < (CONFIG_NFILE_DESCRIPTORS +
- CONFIG_NSOCKET_DESCRIPTORS));
- }
- #endif
- RELEASE_SEARCH(&desc);
- return fd;
- errout_with_fd:
- files_release(fd);
- errout_with_inode:
- inode_release(inode);
- errout_with_search:
- RELEASE_SEARCH(&desc);
- return ret;
- }
- /****************************************************************************
- * Name: nx_open
- *
- * Description:
- * nx_open() is similar to the standard 'open' interface except that is is
- * not a cancellation point and it does not modify the errno variable.
- *
- * nx_open() is an internal NuttX interface and should not be called from
- * applications.
- *
- * Returned Value:
- * Zero (OK) is returned on success; a negated errno value is returned on
- * any failure.
- *
- ****************************************************************************/
- int nx_open(FAR const char *path, int oflags, ...)
- {
- va_list ap;
- int fd;
- /* Let nx_vopen() do all of the work */
- va_start(ap, oflags);
- fd = nx_vopen(path, oflags, ap);
- va_end(ap);
- return fd;
- }
- /****************************************************************************
- * Name: open
- *
- * Description:
- * Standard 'open' interface
- *
- * Returned Value:
- * Zero (OK) is returned on success; -1 (ERROR) is returned on any failure
- * the the errno value set appropriately.
- *
- ****************************************************************************/
- int open(FAR const char *path, int oflags, ...)
- {
- va_list ap;
- int fd;
- /* open() is a cancellation point */
- (void)enter_cancellation_point();
- /* Let nx_vopen() do most of the work */
- va_start(ap, oflags);
- fd = nx_vopen(path, oflags, ap);
- va_end(ap);
- /* Set the errno value if any errors were reported by nx_open() */
- if (fd < 0)
- {
- set_errno(-fd);
- fd = ERROR;
- }
- leave_cancellation_point();
- return fd;
- }
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