1  /* Copyright (C) 1993-2023 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 <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  retry:
      31    HURD_CRITICAL_BEGIN;
      32    __mutex_lock (&_hurd_id.lock);
      33  
      34    if (err = _hurd_check_ids ())
      35      egid = __hurd_fail (err);
      36    else if (_hurd_id.gen.ngids >= 1)
      37      egid = _hurd_id.gen.gids[0];
      38    else if (_hurd_id.aux.ngids >= 1)
      39      /* We have no effective gids.  Return the real gid.  */
      40      egid = _hurd_id.aux.gids[0];
      41    else
      42      /* We do not even have a real gid.  */
      43      egid = __hurd_fail (EGRATUITOUS);
      44  
      45    __mutex_unlock (&_hurd_id.lock);
      46    HURD_CRITICAL_END;
      47    if (egid == -1 && errno == EINTR)
      48      /* Got a signal while inside an RPC of the critical section, retry again */
      49      goto retry;
      50  
      51    return egid;
      52  }
      53  
      54  weak_alias (__getegid, getegid)