glibc/sysdeps/unix/sysv/linux/fxstatat64.c

118 lines
3.1 KiB
C

/* Copyright (C) 2005-2014 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <fcntl.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <kernel_stat.h>
#include <sysdep.h>
#include <sys/syscall.h>
#include <kernel-features.h>
/* Get information about the file NAME in BUF. */
int
__fxstatat64 (int vers, int fd, const char *file, struct stat64 *st, int flag)
{
if (__builtin_expect (vers != _STAT_VER_LINUX, 0))
{
__set_errno (EINVAL);
return -1;
}
int result;
INTERNAL_SYSCALL_DECL (err);
#ifdef __NR_fstatat64
# ifndef __ASSUME_ATFCTS
if (__have_atfcts >= 0)
# endif
{
result = INTERNAL_SYSCALL (fstatat64, err, 4, fd, file, st, flag);
# ifndef __ASSUME_ATFCTS
if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (result, err), 1)
&& INTERNAL_SYSCALL_ERRNO (result, err) == ENOSYS)
__have_atfcts = -1;
else
# endif
if (!__builtin_expect (INTERNAL_SYSCALL_ERROR_P (result, err), 1))
return 0;
else
{
__set_errno (INTERNAL_SYSCALL_ERRNO (result, err));
return -1;
}
}
#endif
#ifndef __ASSUME_ATFCTS
if (flag & ~AT_SYMLINK_NOFOLLOW)
{
__set_errno (EINVAL);
return -1;
}
char *buf = NULL;
if (fd != AT_FDCWD && file[0] != '/')
{
size_t filelen = strlen (file);
if (__builtin_expect (filelen == 0, 0))
{
__set_errno (ENOENT);
return -1;
}
static const char procfd[] = "/proc/self/fd/%d/%s";
/* Buffer for the path name we are going to use. It consists of
- the string /proc/self/fd/
- the file descriptor number
- the file name provided.
The final NUL is included in the sizeof. A bit of overhead
due to the format elements compensates for possible negative
numbers. */
size_t buflen = sizeof (procfd) + sizeof (int) * 3 + filelen;
buf = alloca (buflen);
__snprintf (buf, buflen, procfd, fd, file);
file = buf;
}
if (flag & AT_SYMLINK_NOFOLLOW)
result = INTERNAL_SYSCALL (lstat64, err, 2, file, st);
else
result = INTERNAL_SYSCALL (stat64, err, 2, file, st);
if (__builtin_expect (!INTERNAL_SYSCALL_ERROR_P (result, err), 1))
{
# if defined _HAVE_STAT64___ST_INO && __ASSUME_ST_INO_64_BIT == 0
if (st->__st_ino != (__ino_t) st->st_ino)
st->st_ino = st->__st_ino;
# endif
return result;
}
__atfct_seterrno (INTERNAL_SYSCALL_ERRNO (result, err), fd, buf);
return -1;
#endif
}
libc_hidden_def (__fxstatat64)