sysdeps/mach/hurd/setuid.c

   1 /* Copyright (C) 1991, 1992, 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 <unistd.h>
  22 #include <sys/types.h>
  23 #include <hurd.h>
  24 #include <hurd/id.h>
  25 #include <string.h>
  26
  27 /* Set the user ID of the calling process to UID.
  28    If the calling process is the super-user, the real
  29    and effective user IDs, and the saved set-user-ID to UID;
  30    if not, the effective user ID is set to UID.  */
  31 int
  32 DEFUN(__setuid, (uid), uid_t uid)
  33 {
  34   auth_t newauth;
  35   error_t err;
  36
  37   HURD_CRITICAL_BEGIN;
  38   __mutex_lock (&_hurd_id.lock);
  39   err = _hurd_check_ids ();
  40
  41   if (!err)
  42     {
  43       /* Make a new auth handle which has UID as the real uid,
  44          and as the first element in the list of effective uids.  */
  45
  46       uid_t newgen[_hurd_id.gen.nuids + 1];
  47       uid_t newaux[_hurd_id.aux.nuids];
  48
  49       newgen[0] = uid;
  50       memcpy (&newgen[1], _hurd_id.gen.uids,
  51               _hurd_id.gen.nuids * sizeof (uid_t));
  52       newaux[0] = uid;
  53       memcpy (&newaux[1], _hurd_id.aux.uids,
  54               (_hurd_id.aux.nuids - 1) * sizeof (uid_t));
  55
  56       err = __USEPORT (AUTH, __auth_makeauth
  57                        (port, NULL, 0, MACH_MSG_TYPE_COPY_SEND,
  58                         _hurd_id.gen.uids, _hurd_id.gen.nuids,
  59                         _hurd_id.aux.uids, _hurd_id.aux.nuids,
  60                         newgen, 1 + _hurd_id.gen.nuids,
  61                         newaux, _hurd_id.aux.nuids,
  62                         &newauth));
  63     }
  64   __mutex_unlock (&_hurd_id.lock);
  65   HURD_CRITICAL_END;
  66
  67   if (err)
  68     return __hurd_fail (err);
  69
  70   /* Install the new handle and reauthenticate everything.  */
  71   err = __setauth (newauth);
  72   __mach_port_deallocate (__mach_task_self (), newauth);
  73   return err;
  74 }
  75
  76 weak_alias (__setuid, setuid)