hurd/seteuids.c

   1 /* Copyright (C) 1993-2023 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    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <hurd.h>
  19 #include <hurd/id.h>
  20
  21 /* Set the uid set for the current user to UIDS (N of them).  */
  22 int
  23 seteuids (int n, const uid_t *uids)
  24 {
  25   error_t err;
  26   auth_t newauth;
  27   int i;
  28   gid_t new[n];
  29
  30   /* Fault before taking locks.  */
  31   for (i = 0; i < n; ++i)
  32     new[i] = uids[i];
  33
  34 retry:
  35   HURD_CRITICAL_BEGIN;
  36   __mutex_lock (&_hurd_id.lock);
  37   err = _hurd_check_ids ();
  38   if (! err)
  39     {
  40       /* Get a new auth port using those IDs.  */
  41       err = __USEPORT (AUTH,
  42                        __auth_makeauth (port, NULL, 0, 0,
  43                                         new, n,
  44                                         _hurd_id.aux.uids, _hurd_id.aux.nuids,
  45                                         _hurd_id.gen.gids, _hurd_id.gen.ngids,
  46                                         _hurd_id.aux.gids, _hurd_id.aux.ngids,
  47                                         &newauth));
  48     }
  49   __mutex_unlock (&_hurd_id.lock);
  50   HURD_CRITICAL_END;
  51   if (err == EINTR)
  52     /* Got a signal while inside an RPC of the critical section, retry again */
  53     goto retry;
  54
  55   if (err)
  56     return __hurd_fail (err);
  57
  58   /* Install the new auth port and reauthenticate everything.  */
  59   err = __setauth (newauth);
  60   __mach_port_deallocate (__mach_task_self (), newauth);
  61   return err;
  62 }