sysdeps/mach/hurd/setregid.c

   1 /* Copyright (C) 1993-2016 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    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <sys/types.h>
  20 #include <unistd.h>
  21 #include <hurd.h>
  22 #include <hurd/id.h>
  23 #include <string.h>
  24
  25 int
  26 __setregid (gid_t rgid, gid_t egid)
  27 {
  28   auth_t newauth;
  29   error_t err;
  30
  31   HURD_CRITICAL_BEGIN;
  32   __mutex_lock (&_hurd_id.lock);
  33   err = _hurd_check_ids ();
  34
  35   if (!err)
  36     {
  37       /* Make a new auth handle which has RGID as the real gid,
  38          and EGID as the first element in the list of effective gids.  */
  39
  40       gid_t *newgen, *newaux;
  41       size_t ngen, naux;
  42
  43       newgen = _hurd_id.gen.gids;
  44       ngen = _hurd_id.gen.ngids;
  45       if (egid != -1)
  46         {
  47           if (_hurd_id.gen.ngids == 0)
  48             {
  49               /* No effective gids now.  The new set will be just GID.  */
  50               newgen = &egid;
  51               ngen = 1;
  52             }
  53           else
  54             {
  55               _hurd_id.gen.gids[0] = egid;
  56               _hurd_id.valid = 0;
  57             }
  58         }
  59
  60       newaux = _hurd_id.aux.gids;
  61       naux = _hurd_id.aux.ngids;
  62       if (rgid != -1)
  63         {
  64           if (_hurd_id.aux.ngids == 0)
  65             {
  66               newaux = &rgid;
  67               naux = 1;
  68             }
  69           else
  70             {
  71               _hurd_id.aux.gids[0] = rgid;
  72               _hurd_id.valid = 0;
  73             }
  74         }
  75
  76       err = __USEPORT (AUTH, __auth_makeauth
  77                        (port, NULL, MACH_MSG_TYPE_COPY_SEND, 0,
  78                         _hurd_id.gen.uids, _hurd_id.gen.nuids,
  79                         _hurd_id.aux.uids, _hurd_id.aux.nuids,
  80                         newgen, ngen, newaux, naux,
  81                         &newauth));
  82     }
  83   __mutex_unlock (&_hurd_id.lock);
  84   HURD_CRITICAL_END;
  85
  86   if (err)
  87     return __hurd_fail (err);
  88
  89   /* Install the new handle and reauthenticate everything.  */
  90   err = __setauth (newauth);
  91   __mach_port_deallocate (__mach_task_self (), newauth);
  92   return err;
  93 }
  94
  95 weak_alias (__setregid, setregid)