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/* Copyright (C) 2005-2013 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 <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <kernel-features.h>
#include <sysdep-cancel.h>
#include <not-cancel.h>
#ifndef OPENAT
# define OPENAT openat
# define __OPENAT_2 __openat_2
# ifndef __ASSUME_ATFCTS
/* Set errno after a failed call. If BUF is not null,
it is a /proc/self/fd/ path name we just tried to use. */
void
attribute_hidden
__atfct_seterrno (int errval, int fd, const char *buf)
{
if (buf != NULL)
{
struct stat64 st;
if (errval == ENOTDIR || errval == ENOENT)
{
/* This can mean either the file descriptor is invalid or
/proc is not mounted. */
if (__fxstat64 (_STAT_VER, fd, &st) != 0)
/* errno is already set correctly. */
return;
/* If /proc is not mounted there is nothing we can do. */
if ((errval != ENOTDIR || S_ISDIR (st.st_mode))
&& (__xstat64 (_STAT_VER, "/proc/self/fd", &st) != 0
|| !S_ISDIR (st.st_mode)))
errval = ENOSYS;
}
}
__set_errno (errval);
}
int __have_atfcts;
# endif
#endif
#define OPENAT_NOT_CANCEL CONCAT (OPENAT)
#define CONCAT(name) CONCAT2 (name)
#define CONCAT2(name) __##name##_nocancel
int
OPENAT_NOT_CANCEL (fd, file, oflag, mode)
int fd;
const char *file;
int oflag;
mode_t mode;
{
/* We have to add the O_LARGEFILE flag for openat64. */
#ifdef MORE_OFLAGS
oflag |= MORE_OFLAGS;
#endif
int res;
#ifdef __NR_openat
# ifndef __ASSUME_ATFCTS
if (__have_atfcts >= 0)
# endif
{
res = INLINE_SYSCALL (openat, 4, fd, file, oflag, mode);
# ifndef __ASSUME_ATFCTS
if (res == -1 && errno == ENOSYS)
__have_atfcts = -1;
else
# endif
return res;
}
#endif
#ifndef __ASSUME_ATFCTS
INTERNAL_SYSCALL_DECL (err);
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);
/* Note: snprintf cannot be canceled. */
__snprintf (buf, buflen, procfd, fd, file);
file = buf;
}
res = INTERNAL_SYSCALL (open, err, 3, file, oflag, mode);
if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (res, err), 0))
{
__atfct_seterrno (INTERNAL_SYSCALL_ERRNO (res, err), fd, buf);
res = -1;
}
return res;
#endif
}
#define UNDERIZE(name) UNDERIZE_1 (name)
#define UNDERIZE_1(name) __##name
#define __OPENAT UNDERIZE (OPENAT)
/* Open FILE with access OFLAG. Interpret relative paths relative to
the directory associated with FD. If OFLAG includes O_CREAT, a
third argument is the file protection. */
int
__OPENAT (fd, file, oflag)
int fd;
const char *file;
int oflag;
{
mode_t mode = 0;
if (oflag & O_CREAT)
{
va_list arg;
va_start (arg, oflag);
mode = va_arg (arg, mode_t);
va_end (arg);
}
if (SINGLE_THREAD_P)
return OPENAT_NOT_CANCEL (fd, file, oflag, mode);
int oldtype = LIBC_CANCEL_ASYNC ();
int res = OPENAT_NOT_CANCEL (fd, file, oflag, mode);
LIBC_CANCEL_RESET (oldtype);
return res;
}
libc_hidden_def (__OPENAT)
weak_alias (__OPENAT, OPENAT)
int
__OPENAT_2 (fd, file, oflag)
int fd;
const char *file;
int oflag;
{
if (oflag & O_CREAT)
#define MSG(s) MSG2 (s)
#define MSG2(s) "invalid " #s " call: O_CREAT without mode"
__fortify_fail (MSG (OPENAT));
return __OPENAT (fd, file, oflag);
}
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