sysdeps/mach/hurd/getegid.c

   1 /* Copyright (C) 1993-2018 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    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <unistd.h>
  20 #include <hurd.h>
  21 #include <hurd/id.h>
  22
  23 /* Get the effective group ID of the calling process.  */
  24 gid_t
  25 __getegid (void)
  26 {
  27   error_t err;
  28   gid_t egid;
  29
  30   HURD_CRITICAL_BEGIN;
  31   __mutex_lock (&_hurd_id.lock);
  32
  33   if (err = _hurd_check_ids ())
  34     {
  35       errno = err;
  36       egid = -1;
  37     }
  38   else if (_hurd_id.gen.ngids >= 1)
  39     egid = _hurd_id.gen.gids[0];
  40   else if (_hurd_id.aux.ngids >= 1)
  41     /* We have no effective gids.  Return the real gid.  */
  42     egid = _hurd_id.aux.gids[0];
  43   else
  44     {
  45       /* We do not even have a real gid.  */
  46       errno = EGRATUITOUS;
  47       egid = -1;
  48     }
  49
  50   __mutex_unlock (&_hurd_id.lock);
  51   HURD_CRITICAL_END;
  52
  53   return egid;
  54 }
  55
  56 weak_alias (__getegid, getegid)