sysdeps/mach/hurd/setregid.c

   1 /* Copyright (C) 1993, 1994, 1995, 1997 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <errno.h>
  20 #include <sys/types.h>
  21 #include <unistd.h>
  22 #include <hurd.h>
  23 #include <hurd/id.h>
  24 #include <string.h>
  25
  26 int
  27 __setregid (rgid, egid)
  28      gid_t rgid;
  29      gid_t egid;
  30 {
  31   auth_t newauth;
  32   error_t err;
  33
  34   HURD_CRITICAL_BEGIN;
  35   __mutex_lock (&_hurd_id.lock);
  36   err = _hurd_check_ids ();
  37
  38   if (!err)
  39     {
  40       /* Make a new auth handle which has RGID as the real gid,
  41          and EGID as the first element in the list of effective gids.  */
  42
  43       gid_t *newgen, *newaux;
  44       size_t ngen, naux;
  45
  46       newgen = _hurd_id.gen.gids;
  47       ngen = _hurd_id.gen.ngids;
  48       if (egid != -1)
  49         {
  50           if (_hurd_id.gen.ngids == 0)
  51             {
  52               /* No effective gids now.  The new set will be just GID.  */
  53               newgen = &egid;
  54               ngen = 1;
  55             }
  56           else
  57             {
  58               _hurd_id.gen.gids[0] = egid;
  59               _hurd_id.valid = 0;
  60             }
  61         }
  62
  63       newaux = _hurd_id.aux.gids;
  64       naux = _hurd_id.aux.ngids;
  65       if (rgid != -1)
  66         {
  67           if (_hurd_id.aux.ngids == 0)
  68             {
  69               newaux = &rgid;
  70               naux = 1;
  71             }
  72           else
  73             {
  74               _hurd_id.aux.gids[0] = rgid;
  75               _hurd_id.valid = 0;
  76             }
  77         }
  78
  79       err = __USEPORT (AUTH, __auth_makeauth
  80                        (port, NULL, MACH_MSG_TYPE_COPY_SEND, 0,
  81                         _hurd_id.gen.uids, _hurd_id.gen.nuids,
  82                         _hurd_id.aux.uids, _hurd_id.aux.nuids,
  83                         newgen, ngen, newaux, naux,
  84                         &newauth));
  85     }
  86   __mutex_unlock (&_hurd_id.lock);
  87   HURD_CRITICAL_END;
  88
  89   if (err)
  90     return __hurd_fail (err);
  91
  92   /* Install the new handle and reauthenticate everything.  */
  93   err = __setauth (newauth);
  94   __mach_port_deallocate (__mach_task_self (), newauth);
  95   return err;
  96 }
  97
  98 weak_alias (__setregid, setregid)