nuttx/fs/vfs/fs_readlink.c
Alin Jerpelea f9fb182809 Author: Gregory Nutt: update licenses to Apache
Update files from Gregory Nutt to Apache 2.0 license.

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
2021-02-05 12:15:56 -03:00

128 lines
3.8 KiB
C

/****************************************************************************
* fs/vfs/fs_readlink.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdbool.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/fs/fs.h>
#include "inode/inode.h"
#ifdef CONFIG_PSEUDOFS_SOFTLINKS
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: mkdir
*
* Description:
* The readlink() function will place the contents of the symbolic link
* referred to by 'path' in the buffer 'buf' which has size 'bufsize'. If
* the number of bytes in the symbolic link is less than bufsize, the
* contents of the remainder of 'buf' are unspecified. If the buf argument
* is not large enough to contain the link content, the first bufsize bytes
* will be placed in buf. If the value of bufsize is greater than
* {SSIZE_MAX}, the result is implementation-defined. *
*
* Input Parameters:
* path - The full path to the symbolic link
* buf - The user-provided buffer in which to return the path to the
* link target.
* bufixe - The size of 'buf'
*
* Returned Value:
* Upon successful completion, readlink() will return the count of bytes
* placed in the buffer. Otherwise, it will return a value of -1, leave the
* buffer unchanged, and set errno to indicate the error.
*
****************************************************************************/
ssize_t readlink(FAR const char *path, FAR char *buf, size_t bufsize)
{
struct inode_search_s desc;
FAR struct inode *node;
int errcode;
int ret;
DEBUGASSERT(path != NULL && buf != NULL && bufsize > 0);
/* Find the inode that includes this path (without dereferencing the final)
* symbolic link node.
*/
SETUP_SEARCH(&desc, path, true);
ret = inode_find(&desc);
if (ret < 0)
{
errcode = -ret;
goto errout_with_search;
}
/* Get the search results */
node = desc.node;
DEBUGASSERT(node != NULL);
/* An inode was found that includes this path and possibly refers to a
* symbolic link.
*
* Check if the inode is a valid symbolic link.
*/
if (!INODE_IS_SOFTLINK(node))
{
errcode = EINVAL;
goto errout_with_inode;
}
/* Copy the link target pathto the user-provided buffer. */
*buf = '\0';
strncpy(buf, node->u.i_link, bufsize);
/* Release our reference on the inode and return the length */
inode_release(node);
RELEASE_SEARCH(&desc);
return strlen(buf);
errout_with_inode:
inode_release(node);
errout_with_search:
RELEASE_SEARCH(&desc);
set_errno(errcode);
return ERROR;
}
#endif /* CONFIG_PSEUDOFS_SOFTLINKS */