hurd/setauth.c

   1 /* Copyright (C) 1991-2021 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/port.h>
  20 #include <hurd/id.h>
  21 #include <hurdlock.h>
  22 #include "set-hooks.h"
  23
  24 /* Things in the library which want to be run when the auth port changes.  */
  25 DEFINE_HOOK (_hurd_reauth_hook, (auth_t new_auth));
  26
  27 static unsigned int reauth_lock = LLL_LOCK_INITIALIZER;
  28
  29 /* Set the auth port to NEW, and reauthenticate
  30    everything used by the library.  */
  31 error_t
  32 _hurd_setauth (auth_t new)
  33 {
  34   error_t err;
  35   unsigned int d;
  36   mach_port_t newport, ref;
  37
  38   /* Give the new send right a user reference.
  39      This is a good way to check that it is valid.  */
  40   if (err = __mach_port_mod_refs (__mach_task_self (), new,
  41                                   MACH_PORT_RIGHT_SEND, 1))
  42     return err;
  43
  44   HURD_CRITICAL_BEGIN;
  45
  46   /* We lock against another thread doing setauth.  Anyone who sets
  47      _hurd_ports[INIT_PORT_AUTH] some other way is asking to lose.  */
  48   __mutex_lock (&reauth_lock);
  49
  50   /* Install the new port in the cell.  */
  51   __mutex_lock (&_hurd_id.lock);
  52   _hurd_port_set (&_hurd_ports[INIT_PORT_AUTH], new);
  53   _hurd_id.valid = 0;
  54   if (_hurd_id.rid_auth)
  55     {
  56       __mach_port_deallocate (__mach_task_self (), _hurd_id.rid_auth);
  57       _hurd_id.rid_auth = MACH_PORT_NULL;
  58     }
  59   __mutex_unlock (&_hurd_id.lock);
  60
  61   if (_hurd_init_dtable != NULL)
  62     /* We just have the simple table we got at startup.
  63        Otherwise, a reauth_hook in dtable.c takes care of this.  */
  64     for (d = 0; d < _hurd_init_dtablesize; ++d)
  65       if (_hurd_init_dtable[d] != MACH_PORT_NULL)
  66         {
  67           mach_port_t new;
  68           ref = __mach_reply_port ();
  69           if (! __io_reauthenticate (_hurd_init_dtable[d],
  70                                      ref, MACH_MSG_TYPE_MAKE_SEND)
  71               && ! HURD_PORT_USE (&_hurd_ports[INIT_PORT_AUTH],
  72                                   __auth_user_authenticate
  73                                   (port,
  74                                    ref, MACH_MSG_TYPE_MAKE_SEND,
  75                                    &new)))
  76             {
  77               __mach_port_deallocate (__mach_task_self (),
  78                                       _hurd_init_dtable[d]);
  79               _hurd_init_dtable[d] = new;
  80             }
  81           __mach_port_destroy (__mach_task_self (), ref);
  82         }
  83
  84   ref = __mach_reply_port ();
  85   if (__USEPORT (CRDIR,
  86                  ! __io_reauthenticate (port,
  87                                         ref, MACH_MSG_TYPE_MAKE_SEND)
  88                  && ! __auth_user_authenticate (new,
  89                                                 ref, MACH_MSG_TYPE_MAKE_SEND,
  90                                                 &newport)))
  91     _hurd_port_set (&_hurd_ports[INIT_PORT_CRDIR], newport);
  92   __mach_port_destroy (__mach_task_self (), ref);
  93
  94   ref = __mach_reply_port ();
  95   if (__USEPORT (CWDIR,
  96                  ! __io_reauthenticate (port,
  97                                         ref, MACH_MSG_TYPE_MAKE_SEND)
  98                  && ! __auth_user_authenticate (new,
  99                                                 ref, MACH_MSG_TYPE_MAKE_SEND,
 100                                                 &newport)))
 101     _hurd_port_set (&_hurd_ports[INIT_PORT_CWDIR], newport);
 102   __mach_port_destroy (__mach_task_self (), ref);
 103
 104   /* Run things which want to do reauthorization stuff.  */
 105   RUN_HOOK (_hurd_reauth_hook, (new));
 106
 107   __mutex_unlock (&reauth_lock);
 108
 109   HURD_CRITICAL_END;
 110
 111   return 0;
 112 }
 113
 114 int
 115 __setauth (auth_t new)
 116 {
 117   error_t err = _hurd_setauth (new);
 118   return err ? __hurd_fail (err) : 0;
 119 }
 120
 121 weak_alias (__setauth, setauth)