sysdeps/mach/hurd/getresuid.c

   1 /* getresuid -- fetch real user ID, effective user ID, and saved-set user ID
   2    Copyright (C) 2002-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <unistd.h>
  21 #include <hurd.h>
  22 #include <hurd/id.h>
  23
  24 /* Fetch the real user ID, effective user ID, and saved-set user ID,
  25    of the calling process.  */
  26 int
  27 __getresuid (uid_t *ruid, uid_t *euid, uid_t *suid)
  28 {
  29   error_t err;
  30
  31 retry:
  32   HURD_CRITICAL_BEGIN;
  33   __mutex_lock (&_hurd_id.lock);
  34
  35   err = _hurd_check_ids ();
  36   if (!err)
  37     {
  38       if (_hurd_id.aux.nuids < 1)
  39         /* We do not even have a real UID.  */
  40         err = EGRATUITOUS;
  41       else
  42         {
  43           uid_t real = _hurd_id.aux.uids[0];
  44
  45           *ruid = real;
  46           *euid = _hurd_id.gen.nuids < 1 ? real : _hurd_id.gen.uids[0];
  47           *suid = _hurd_id.aux.nuids < 2 ? real : _hurd_id.aux.uids[1];
  48         }
  49     }
  50
  51   __mutex_unlock (&_hurd_id.lock);
  52   HURD_CRITICAL_END;
  53   if (err == EINTR)
  54     /* Got a signal while inside an RPC of the critical section, retry again */
  55     goto retry;
  56
  57   return __hurd_fail (err);
  58 }
  59 libc_hidden_def (__getresuid)
  60 weak_alias (__getresuid, getresuid)