sysdeps/mach/hurd/setregid.c

   1 /* Copyright (C) 1993, 1994, 1995 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 Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 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 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ansidecl.h>
  20 #include <errno.h>
  21 #include <sys/types.h>
  22 #include <unistd.h>
  23 #include <hurd.h>
  24 #include <hurd/id.h>
  25 #include <string.h>
  26
  27 int
  28 __setregid (gid_t rgid, gid_t egid)
  29 {
  30   auth_t newauth;
  31   error_t err;
  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 RGID as the real gid,
  40          and EGID as the first element in the list of effective gids.  */
  41
  42       gid_t *newgen, *newaux;
  43       size_t ngen, naux;
  44
  45       newgen = _hurd_id.gen.gids;
  46       ngen = _hurd_id.gen.ngids;
  47       if (egid != -1)
  48         {
  49           if (_hurd_id.gen.ngids == 0)
  50             {
  51               /* No effective gids now.  The new set will be just GID.  */
  52               newgen = &egid;
  53               ngen = 1;
  54             }
  55           else
  56             {
  57               _hurd_id.gen.gids[0] = egid;
  58               _hurd_id.valid = 0;
  59             }
  60         }
  61
  62       newaux = _hurd_id.aux.gids;
  63       naux = _hurd_id.aux.ngids;
  64       if (rgid != -1)
  65         {
  66           if (_hurd_id.aux.ngids == 0)
  67             {
  68               newaux = &rgid;
  69               naux = 1;
  70             }
  71           else
  72             {
  73               _hurd_id.aux.gids[0] = rgid;
  74               _hurd_id.valid = 0;
  75             }
  76         }
  77
  78       err = __USEPORT (AUTH, __auth_makeauth
  79                        (port, NULL, MACH_MSG_TYPE_COPY_SEND, 0,
  80                         _hurd_id.gen.uids, _hurd_id.gen.nuids,
  81                         _hurd_id.aux.uids, _hurd_id.aux.nuids,
  82                         newgen, ngen, newaux, naux,
  83                         &newauth));
  84     }
  85   __mutex_unlock (&_hurd_id.lock);
  86   HURD_CRITICAL_END;
  87
  88   if (err)
  89     return __hurd_fail (err);
  90
  91   /* Install the new handle and reauthenticate everything.  */
  92   err = __setauth (newauth);
  93   __mach_port_deallocate (__mach_task_self (), newauth);
  94   return err;
  95 }
  96
  97 weak_alias (__setregid, setregid)