sysdeps/mach/hurd/setresgid.c

   1 /* setresgid -- set real group ID, effective group ID, and saved-set group ID
   2    Copyright (C) 2002, 2005, 2006 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    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <unistd.h>
  21 #include <hurd.h>
  22 #include <hurd/id.h>
  23
  24 /* Set the real group ID, effective group ID, and saved-set group ID,
  25    of the calling process to RGID, EGID, and SGID, respectively.  */
  26 int
  27 __setresgid (gid_t rgid, gid_t egid, gid_t sgid)
  28 {
  29   auth_t newauth;
  30   error_t err;
  31   gid_t agids[2] = { rgid, sgid };
  32
  33   HURD_CRITICAL_BEGIN;
  34   __mutex_lock (&_hurd_id.lock);
  35   err = _hurd_check_ids ();
  36
  37   if (!err)
  38     {
  39       /* Make a new auth handle which has EGID as the first element in the
  40          list of effective gids.  */
  41
  42       if (_hurd_id.gen.ngids > 0)
  43         {
  44           _hurd_id.gen.gids[0] = egid;
  45           _hurd_id.valid = 0;
  46         }
  47       if (_hurd_id.aux.ngids > 1)
  48         {
  49           _hurd_id.aux.gids[0] = rgid;
  50           _hurd_id.aux.gids[1] = sgid;
  51           _hurd_id.valid = 0;
  52         }
  53
  54       err = __USEPORT (AUTH, __auth_makeauth
  55                        (port, NULL, MACH_MSG_TYPE_COPY_SEND, 0,
  56                         _hurd_id.gen.uids, _hurd_id.gen.nuids,
  57                         _hurd_id.aux.uids, _hurd_id.aux.nuids,
  58                         _hurd_id.gen.ngids ? _hurd_id.gen.gids : &egid,
  59                         _hurd_id.gen.ngids ?: 1,
  60                         _hurd_id.aux.ngids > 1 ? _hurd_id.aux.gids : agids,
  61                         _hurd_id.aux.ngids > 1 ? _hurd_id.aux.ngids : 2,
  62                         &newauth));
  63     }
  64
  65   __mutex_unlock (&_hurd_id.lock);
  66   HURD_CRITICAL_END;
  67
  68   if (err)
  69     return __hurd_fail (err);
  70
  71   /* Install the new handle and reauthenticate everything.  */
  72   err = __setauth (newauth);
  73   __mach_port_deallocate (__mach_task_self (), newauth);
  74   return err;
  75 }
  76 libc_hidden_def (__setresgid)
  77 weak_alias (__setresgid, setresgid)