incubator-nuttx/libs/libc/unistd/lib_access.c

150 lines
4.7 KiB
C

/****************************************************************************
* libs/libc/unistd/lib_access.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 <errno.h>
#include <sys/stat.h>
#include <unistd.h>
#include "libc.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Type Definitions
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: access
*
* Description:
* The access() function shall check the file named by the pathname pointed
* to by the path argument for accessibility according to the bit pattern
* contained in amode, using the real user ID in place of the effective
* user ID and the real group ID in place of the effective group ID.
* As there are no users in NuttX, the function always succeeds.
*
* Input Parameters:
* path - a pointer to the path
* amode - the access mode
*
* Returned Value:
* Return OK (zero) if the caller can access the file with the required
* permission, otherwise return -1.
*
* Assumptions:
*
****************************************************************************/
int access(FAR const char *path, int amode)
{
struct stat s;
if (stat(path, &s))
{
return -1;
}
if (s.st_mode & S_IFDIR)
{
return 0;
}
if (amode & W_OK)
{
if (s.st_mode & S_IWUSR)
{
return 0;
}
return -1;
}
return 0;
}
/****************************************************************************
* Name: faccessat
*
* Description:
* The faccessat() system call operates in exactly the same way as
* access(), except for the differences described here.
*
* If the pathname given in pathname is relative, then it is interpreted
* relative to the directory referred to by the file descriptor dirfd
* (rather than relative to the current working directory of the calling
* process)
*
* If pathname is relative and dirfd is the special value AT_FDCWD, then
* pathname is interpreted relative to the current working directory of
* the calling process (like access()).
*
* If pathname is absolute, then dirfd is ignored.
*
* Input Parameters:
* dirfd - The file descriptor of directory.
* path - A pointer to the path.
* amode - The access mode.
* flags - Ignored.
*
* Returned Value:
* Return zero on success, or -1 if an error occurred (in which case,
* errno is set appropriately).
*
****************************************************************************/
int faccessat(int dirfd, FAR const char *path, int amode, int flags)
{
char fullpath[PATH_MAX];
int ret;
ret = lib_getfullpath(dirfd, path, fullpath, sizeof(fullpath));
if (ret < 0)
{
set_errno(-ret);
return ERROR;
}
return access(fullpath, amode);
}