io/openat64.c

   1 /* Copyright (C) 2005-2023 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <fcntl.h>
  20 #include <stdarg.h>
  21 #include <stddef.h>
  22 #include <stdio.h>
  23 #include <sys/stat.h>
  24
  25 /* Open FILE with access OFLAG.  Interpret relative paths relative to
  26    the directory associated with FD.  If O_CREAT or O_TMPFILE is in OFLAG, a
  27    third argument is the file protection.  */
  28 int
  29 __openat64 (int fd, const char *file, int oflag, ...)
  30 {
  31   int mode;
  32
  33   if (file == NULL)
  34     {
  35       __set_errno (EINVAL);
  36       return -1;
  37     }
  38
  39   if (fd != AT_FDCWD && file[0] != '/')
  40     {
  41       /* Check FD is associated with a directory.  */
  42       struct stat64 st;
  43       if (__fstat64 (fd, &st) != 0)
  44         return -1;
  45
  46       if (!S_ISDIR (st.st_mode))
  47         {
  48           __set_errno (ENOTDIR);
  49           return -1;
  50         }
  51     }
  52
  53   if (__OPEN_NEEDS_MODE (oflag))
  54     {
  55       va_list arg;
  56       va_start (arg, oflag);
  57       mode = va_arg (arg, int);
  58       va_end (arg);
  59
  60       ignore_value (mode);
  61     }
  62
  63   __set_errno (ENOSYS);
  64   return -1;
  65 }
  66 libc_hidden_def (__openat64)
  67 weak_alias (__openat64, openat64)
  68 stub_warning (openat64)
  69
  70 /* __openat64_2 is a generic wrapper that calls __openat64.
  71    So give a stub warning for that symbol too.  */
  72 stub_warning (__openat_2)