bus.c revision b93476ce07acce83ff3b396616bb8a0eaf719916 
1/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2/* bus.c  message bus context object
3 *
4 * Copyright (C) 2003, 2004 Red Hat, Inc.
5 *
6 * Licensed under the Academic Free License version 2.1
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
21 *
22 */
23
24#include "bus.h"
25#include "activation.h"
26#include "connection.h"
27#include "services.h"
28#include "utils.h"
29#include "policy.h"
30#include "config-parser.h"
31#include "signals.h"
32#include "selinux.h"
33#include "dir-watch.h"
34#include <dbus/dbus-list.h>
35#include <dbus/dbus-hash.h>
36#include <dbus/dbus-internals.h>
37
38struct BusContext
39{
40  int refcount;
41  DBusGUID uuid;
42  char *config_file;
43  char *type;
44  char *servicehelper;
45  char *address;
46  char *pidfile;
47  char *user;
48  DBusLoop *loop;
49  DBusList *servers;
50  BusConnections *connections;
51  BusActivation *activation;
52  BusRegistry *registry;
53  BusPolicy *policy;
54  BusMatchmaker *matchmaker;
55  BusLimits limits;
56  unsigned int fork : 1;
57  unsigned int syslog : 1;
58  unsigned int keep_umask : 1;
59};
60
61static dbus_int32_t server_data_slot = -1;
62
63typedef struct
64{
65  BusContext *context;
66} BusServerData;
67
68#define BUS_SERVER_DATA(server) (dbus_server_get_data ((server), server_data_slot))
69
70static BusContext*
71server_get_context (DBusServer *server)
72{
73  BusContext *context;
74  BusServerData *bd;
75
76  if (!dbus_server_allocate_data_slot (&server_data_slot))
77    return NULL;
78
79  bd = BUS_SERVER_DATA (server);
80  if (bd == NULL)
81    {
82      dbus_server_free_data_slot (&server_data_slot);
83      return NULL;
84    }
85
86  context = bd->context;
87
88  dbus_server_free_data_slot (&server_data_slot);
89
90  return context;
91}
92
93static dbus_bool_t
94server_watch_callback (DBusWatch     *watch,
95                       unsigned int   condition,
96                       void          *data)
97{
98  /* FIXME this can be done in dbus-mainloop.c
99   * if the code in activation.c for the babysitter
100   * watch handler is fixed.
101   */
102
103  return dbus_watch_handle (watch, condition);
104}
105
106static dbus_bool_t
107add_server_watch (DBusWatch  *watch,
108                  void       *data)
109{
110  DBusServer *server = data;
111  BusContext *context;
112
113  context = server_get_context (server);
114
115  return _dbus_loop_add_watch (context->loop,
116                               watch, server_watch_callback, server,
117                               NULL);
118}
119
120static void
121remove_server_watch (DBusWatch  *watch,
122                     void       *data)
123{
124  DBusServer *server = data;
125  BusContext *context;
126
127  context = server_get_context (server);
128
129  _dbus_loop_remove_watch (context->loop,
130                           watch, server_watch_callback, server);
131}
132
133
134static void
135server_timeout_callback (DBusTimeout   *timeout,
136                         void          *data)
137{
138  /* can return FALSE on OOM but we just let it fire again later */
139  dbus_timeout_handle (timeout);
140}
141
142static dbus_bool_t
143add_server_timeout (DBusTimeout *timeout,
144                    void        *data)
145{
146  DBusServer *server = data;
147  BusContext *context;
148
149  context = server_get_context (server);
150
151  return _dbus_loop_add_timeout (context->loop,
152                                 timeout, server_timeout_callback, server, NULL);
153}
154
155static void
156remove_server_timeout (DBusTimeout *timeout,
157                       void        *data)
158{
159  DBusServer *server = data;
160  BusContext *context;
161
162  context = server_get_context (server);
163
164  _dbus_loop_remove_timeout (context->loop,
165                             timeout, server_timeout_callback, server);
166}
167
168static void
169new_connection_callback (DBusServer     *server,
170                         DBusConnection *new_connection,
171                         void           *data)
172{
173  BusContext *context = data;
174
175  if (!bus_connections_setup_connection (context->connections, new_connection))
176    {
177      _dbus_verbose ("No memory to setup new connection\n");
178
179      /* if we don't do this, it will get unref'd without
180       * being disconnected... kind of strange really
181       * that we have to do this, people won't get it right
182       * in general.
183       */
184      dbus_connection_close (new_connection);
185    }
186
187  dbus_connection_set_max_received_size (new_connection,
188                                         context->limits.max_incoming_bytes);
189
190  dbus_connection_set_max_message_size (new_connection,
191                                        context->limits.max_message_size);
192
193  /* on OOM, we won't have ref'd the connection so it will die. */
194}
195
196static void
197free_server_data (void *data)
198{
199  BusServerData *bd = data;
200
201  dbus_free (bd);
202}
203
204static dbus_bool_t
205setup_server (BusContext *context,
206              DBusServer *server,
207              char      **auth_mechanisms,
208              DBusError  *error)
209{
210  BusServerData *bd;
211
212  bd = dbus_new0 (BusServerData, 1);
213  if (bd == NULL || !dbus_server_set_data (server,
214                                           server_data_slot,
215                                           bd, free_server_data))
216    {
217      dbus_free (bd);
218      BUS_SET_OOM (error);
219      return FALSE;
220    }
221
222  bd->context = context;
223
224  if (!dbus_server_set_auth_mechanisms (server, (const char**) auth_mechanisms))
225    {
226      BUS_SET_OOM (error);
227      return FALSE;
228    }
229
230  dbus_server_set_new_connection_function (server,
231                                           new_connection_callback,
232                                           context, NULL);
233
234  if (!dbus_server_set_watch_functions (server,
235                                        add_server_watch,
236                                        remove_server_watch,
237                                        NULL,
238                                        server,
239                                        NULL))
240    {
241      BUS_SET_OOM (error);
242      return FALSE;
243    }
244
245  if (!dbus_server_set_timeout_functions (server,
246                                          add_server_timeout,
247                                          remove_server_timeout,
248                                          NULL,
249                                          server, NULL))
250    {
251      BUS_SET_OOM (error);
252      return FALSE;
253    }
254
255  return TRUE;
256}
257
258/* This code only gets executed the first time the
259 * config files are parsed.  It is not executed
260 * when config files are reloaded.
261 */
262static dbus_bool_t
263process_config_first_time_only (BusContext      *context,
264				BusConfigParser *parser,
265				DBusError       *error)
266{
267  DBusList *link;
268  DBusList **addresses;
269  const char *user, *pidfile;
270  char **auth_mechanisms;
271  DBusList **auth_mechanisms_list;
272  int len;
273  dbus_bool_t retval;
274
275  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
276
277  retval = FALSE;
278  auth_mechanisms = NULL;
279
280  /* Check for an existing pid file. Of course this is a race;
281   * we'd have to use fcntl() locks on the pid file to
282   * avoid that. But we want to check for the pid file
283   * before overwriting any existing sockets, etc.
284   */
285  pidfile = bus_config_parser_get_pidfile (parser);
286  if (pidfile != NULL)
287    {
288      DBusString u;
289      DBusStat stbuf;
290
291      _dbus_string_init_const (&u, pidfile);
292
293      if (_dbus_stat (&u, &stbuf, NULL))
294	{
295	  dbus_set_error (error, DBUS_ERROR_FAILED,
296			  "The pid file \"%s\" exists, if the message bus is not running, remove this file",
297			  pidfile);
298	  goto failed;
299	}
300    }
301
302  /* keep around the pid filename so we can delete it later */
303  context->pidfile = _dbus_strdup (pidfile);
304
305  /* Build an array of auth mechanisms */
306
307  auth_mechanisms_list = bus_config_parser_get_mechanisms (parser);
308  len = _dbus_list_get_length (auth_mechanisms_list);
309
310  if (len > 0)
311    {
312      int i;
313
314      auth_mechanisms = dbus_new0 (char*, len + 1);
315      if (auth_mechanisms == NULL)
316	{
317	  BUS_SET_OOM (error);
318	  goto failed;
319	}
320
321      i = 0;
322      link = _dbus_list_get_first_link (auth_mechanisms_list);
323      while (link != NULL)
324        {
325          auth_mechanisms[i] = _dbus_strdup (link->data);
326          if (auth_mechanisms[i] == NULL)
327	    {
328	      BUS_SET_OOM (error);
329	      goto failed;
330	    }
331          link = _dbus_list_get_next_link (auth_mechanisms_list, link);
332        }
333    }
334  else
335    {
336      auth_mechanisms = NULL;
337    }
338
339  /* Listen on our addresses */
340
341  addresses = bus_config_parser_get_addresses (parser);
342
343  link = _dbus_list_get_first_link (addresses);
344  while (link != NULL)
345    {
346      DBusServer *server;
347
348      server = dbus_server_listen (link->data, error);
349      if (server == NULL)
350	{
351	  _DBUS_ASSERT_ERROR_IS_SET (error);
352	  goto failed;
353	}
354      else if (!setup_server (context, server, auth_mechanisms, error))
355	{
356	  _DBUS_ASSERT_ERROR_IS_SET (error);
357	  goto failed;
358	}
359
360      if (!_dbus_list_append (&context->servers, server))
361        {
362          BUS_SET_OOM (error);
363          goto failed;
364        }
365
366      link = _dbus_list_get_next_link (addresses, link);
367    }
368
369  /* note that type may be NULL */
370  context->type = _dbus_strdup (bus_config_parser_get_type (parser));
371  if (bus_config_parser_get_type (parser) != NULL && context->type == NULL)
372    {
373      BUS_SET_OOM (error);
374      goto failed;
375    }
376
377  user = bus_config_parser_get_user (parser);
378  if (user != NULL)
379    {
380      context->user = _dbus_strdup (user);
381      if (context->user == NULL)
382	{
383	  BUS_SET_OOM (error);
384	  goto failed;
385	}
386    }
387
388  context->fork = bus_config_parser_get_fork (parser);
389  context->syslog = bus_config_parser_get_syslog (parser);
390  context->keep_umask = bus_config_parser_get_keep_umask (parser);
391
392  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
393  retval = TRUE;
394
395 failed:
396  dbus_free_string_array (auth_mechanisms);
397  return retval;
398}
399
400/* This code gets executed every time the config files
401 * are parsed: both during BusContext construction
402 * and on reloads. This function is slightly screwy
403 * since it can do a "half reload" in out-of-memory
404 * situations. Realistically, unlikely to ever matter.
405 */
406static dbus_bool_t
407process_config_every_time (BusContext      *context,
408			   BusConfigParser *parser,
409			   dbus_bool_t      is_reload,
410			   DBusError       *error)
411{
412  DBusString full_address;
413  DBusList *link;
414  DBusList **dirs;
415  BusActivation *new_activation;
416  char *addr;
417  const char *servicehelper;
418  char *s;
419
420  dbus_bool_t retval;
421
422  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
423
424  addr = NULL;
425  retval = FALSE;
426
427  if (!_dbus_string_init (&full_address))
428    {
429      BUS_SET_OOM (error);
430      return FALSE;
431    }
432
433  /* get our limits and timeout lengths */
434  bus_config_parser_get_limits (parser, &context->limits);
435
436  if (context->policy)
437    bus_policy_unref (context->policy);
438  context->policy = bus_config_parser_steal_policy (parser);
439  _dbus_assert (context->policy != NULL);
440
441  /* We have to build the address backward, so that
442   * <listen> later in the config file have priority
443   */
444  link = _dbus_list_get_last_link (&context->servers);
445  while (link != NULL)
446    {
447      addr = dbus_server_get_address (link->data);
448      if (addr == NULL)
449        {
450          BUS_SET_OOM (error);
451          goto failed;
452        }
453
454      if (_dbus_string_get_length (&full_address) > 0)
455        {
456          if (!_dbus_string_append (&full_address, ";"))
457            {
458              BUS_SET_OOM (error);
459              goto failed;
460            }
461        }
462
463      if (!_dbus_string_append (&full_address, addr))
464        {
465          BUS_SET_OOM (error);
466          goto failed;
467        }
468
469      dbus_free (addr);
470      addr = NULL;
471
472      link = _dbus_list_get_prev_link (&context->servers, link);
473    }
474
475  if (is_reload)
476    dbus_free (context->address);
477
478  if (!_dbus_string_copy_data (&full_address, &context->address))
479    {
480      BUS_SET_OOM (error);
481      goto failed;
482    }
483
484  /* get the service directories */
485  dirs = bus_config_parser_get_service_dirs (parser);
486
487  /* and the service helper */
488  servicehelper = bus_config_parser_get_servicehelper (parser);
489
490  s = _dbus_strdup(servicehelper);
491  if (s == NULL && servicehelper != NULL)
492    {
493      BUS_SET_OOM (error);
494      goto failed;
495    }
496  else
497    {
498      dbus_free(context->servicehelper);
499      context->servicehelper = s;
500    }
501
502  /* Create activation subsystem */
503  if (context->activation)
504    {
505      if (!bus_activation_reload (context->activation, &full_address, dirs, error))
506        goto failed;
507    }
508  else
509    {
510      context->activation = bus_activation_new (context, &full_address, dirs, error);
511    }
512
513  if (context->activation == NULL)
514    {
515      _DBUS_ASSERT_ERROR_IS_SET (error);
516      goto failed;
517    }
518
519  /* Drop existing conf-dir watches (if applicable) */
520
521  if (is_reload)
522    bus_drop_all_directory_watches ();
523
524  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
525  retval = TRUE;
526
527 failed:
528  _dbus_string_free (&full_address);
529
530  if (addr)
531    dbus_free (addr);
532
533  return retval;
534}
535
536static dbus_bool_t
537process_config_postinit (BusContext      *context,
538			 BusConfigParser *parser,
539			 DBusError       *error)
540{
541  DBusHashTable *service_context_table;
542
543  service_context_table = bus_config_parser_steal_service_context_table (parser);
544  if (!bus_registry_set_service_context_table (context->registry,
545					       service_context_table))
546    {
547      BUS_SET_OOM (error);
548      return FALSE;
549    }
550
551  _dbus_hash_table_unref (service_context_table);
552
553  /* Watch all conf directories */
554  _dbus_list_foreach (bus_config_parser_get_conf_dirs (parser),
555		      (DBusForeachFunction) bus_watch_directory,
556		      context);
557
558  return TRUE;
559}
560
561BusContext*
562bus_context_new (const DBusString *config_file,
563                 ForceForkSetting  force_fork,
564                 DBusPipe         *print_addr_pipe,
565                 DBusPipe         *print_pid_pipe,
566                 DBusError        *error)
567{
568  BusContext *context;
569  BusConfigParser *parser;
570
571  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
572
573  context = NULL;
574  parser = NULL;
575
576  if (!dbus_server_allocate_data_slot (&server_data_slot))
577    {
578      BUS_SET_OOM (error);
579      return NULL;
580    }
581
582  context = dbus_new0 (BusContext, 1);
583  if (context == NULL)
584    {
585      BUS_SET_OOM (error);
586      goto failed;
587    }
588  context->refcount = 1;
589
590  _dbus_generate_uuid (&context->uuid);
591
592  if (!_dbus_string_copy_data (config_file, &context->config_file))
593    {
594      BUS_SET_OOM (error);
595      goto failed;
596    }
597
598  context->loop = _dbus_loop_new ();
599  if (context->loop == NULL)
600    {
601      BUS_SET_OOM (error);
602      goto failed;
603    }
604
605  context->registry = bus_registry_new (context);
606  if (context->registry == NULL)
607    {
608      BUS_SET_OOM (error);
609      goto failed;
610    }
611
612  parser = bus_config_load (config_file, TRUE, NULL, error);
613  if (parser == NULL)
614    {
615      _DBUS_ASSERT_ERROR_IS_SET (error);
616      goto failed;
617    }
618
619  if (!process_config_first_time_only (context, parser, error))
620    {
621      _DBUS_ASSERT_ERROR_IS_SET (error);
622      goto failed;
623    }
624  if (!process_config_every_time (context, parser, FALSE, error))
625    {
626      _DBUS_ASSERT_ERROR_IS_SET (error);
627      goto failed;
628    }
629
630  /* we need another ref of the server data slot for the context
631   * to own
632   */
633  if (!dbus_server_allocate_data_slot (&server_data_slot))
634    _dbus_assert_not_reached ("second ref of server data slot failed");
635
636  /* Note that we don't know whether the print_addr_pipe is
637   * one of the sockets we're using to listen on, or some
638   * other random thing. But I think the answer is "don't do
639   * that then"
640   */
641  if (print_addr_pipe != NULL && _dbus_pipe_is_valid (print_addr_pipe))
642    {
643      DBusString addr;
644      const char *a = bus_context_get_address (context);
645      int bytes;
646
647      _dbus_assert (a != NULL);
648      if (!_dbus_string_init (&addr))
649        {
650          BUS_SET_OOM (error);
651          goto failed;
652        }
653
654      if (!_dbus_string_append (&addr, a) ||
655          !_dbus_string_append (&addr, "\n"))
656        {
657          _dbus_string_free (&addr);
658          BUS_SET_OOM (error);
659          goto failed;
660        }
661
662      bytes = _dbus_string_get_length (&addr);
663      if (_dbus_pipe_write (print_addr_pipe, &addr, 0, bytes, error) != bytes)
664        {
665          /* pipe write returns an error on failure but not short write */
666          if (error != NULL && !dbus_error_is_set (error))
667            {
668              dbus_set_error (error, DBUS_ERROR_FAILED,
669                              "Printing message bus address: did not write all bytes\n");
670            }
671          _dbus_string_free (&addr);
672          goto failed;
673        }
674
675      if (!_dbus_pipe_is_stdout_or_stderr (print_addr_pipe))
676        _dbus_pipe_close (print_addr_pipe, NULL);
677
678      _dbus_string_free (&addr);
679    }
680
681  context->connections = bus_connections_new (context);
682  if (context->connections == NULL)
683    {
684      BUS_SET_OOM (error);
685      goto failed;
686    }
687
688  context->matchmaker = bus_matchmaker_new ();
689  if (context->matchmaker == NULL)
690    {
691      BUS_SET_OOM (error);
692      goto failed;
693    }
694
695  /* check user before we fork */
696  if (context->user != NULL)
697    {
698      if (!_dbus_verify_daemon_user (context->user))
699        {
700          dbus_set_error (error, DBUS_ERROR_FAILED,
701                          "Could not get UID and GID for username \"%s\"",
702                          context->user);
703          goto failed;
704        }
705    }
706
707  /* Now become a daemon if appropriate and write out pid file in any case */
708  {
709    DBusString u;
710
711    if (context->pidfile)
712      _dbus_string_init_const (&u, context->pidfile);
713
714    if ((force_fork != FORK_NEVER && context->fork) || force_fork == FORK_ALWAYS)
715      {
716        _dbus_verbose ("Forking and becoming daemon\n");
717
718        if (!_dbus_become_daemon (context->pidfile ? &u : NULL,
719                                  print_pid_pipe,
720                                  error,
721                                  context->keep_umask))
722          {
723            _DBUS_ASSERT_ERROR_IS_SET (error);
724            goto failed;
725          }
726      }
727    else
728      {
729        _dbus_verbose ("Fork not requested\n");
730
731        /* Need to write PID file and to PID pipe for ourselves,
732         * not for the child process. This is a no-op if the pidfile
733         * is NULL and print_pid_pipe is NULL.
734         */
735        if (!_dbus_write_pid_to_file_and_pipe (context->pidfile ? &u : NULL,
736                                               print_pid_pipe,
737                                               _dbus_getpid (),
738                                               error))
739          {
740            _DBUS_ASSERT_ERROR_IS_SET (error);
741            goto failed;
742          }
743      }
744  }
745
746  if (print_pid_pipe && _dbus_pipe_is_valid (print_pid_pipe) &&
747      !_dbus_pipe_is_stdout_or_stderr (print_pid_pipe))
748    _dbus_pipe_close (print_pid_pipe, NULL);
749
750  if (!bus_selinux_full_init ())
751    {
752      _dbus_warn ("SELinux initialization failed\n");
753    }
754
755  if (!process_config_postinit (context, parser, error))
756    {
757      _DBUS_ASSERT_ERROR_IS_SET (error);
758      goto failed;
759    }
760
761  if (parser != NULL)
762    {
763      bus_config_parser_unref (parser);
764      parser = NULL;
765    }
766
767  /* Here we change our credentials if required,
768   * as soon as we've set up our sockets and pidfile
769   */
770  if (context->user != NULL)
771    {
772      if (!_dbus_change_to_daemon_user (context->user, error))
773	{
774	  _DBUS_ASSERT_ERROR_IS_SET (error);
775	  goto failed;
776	}
777
778#ifdef HAVE_SELINUX
779      /* FIXME - why not just put this in full_init() below? */
780      bus_selinux_audit_init ();
781#endif
782    }
783
784  dbus_server_free_data_slot (&server_data_slot);
785
786  return context;
787
788 failed:
789  if (parser != NULL)
790    bus_config_parser_unref (parser);
791  if (context != NULL)
792    bus_context_unref (context);
793
794  if (server_data_slot >= 0)
795    dbus_server_free_data_slot (&server_data_slot);
796
797  return NULL;
798}
799
800dbus_bool_t
801bus_context_get_id (BusContext       *context,
802                    DBusString       *uuid)
803{
804  return _dbus_uuid_encode (&context->uuid, uuid);
805}
806
807dbus_bool_t
808bus_context_reload_config (BusContext *context,
809			   DBusError  *error)
810{
811  BusConfigParser *parser;
812  DBusString config_file;
813  dbus_bool_t ret;
814
815  /* Flush the user database cache */
816  _dbus_flush_caches ();
817
818  ret = FALSE;
819  _dbus_string_init_const (&config_file, context->config_file);
820  parser = bus_config_load (&config_file, TRUE, NULL, error);
821  if (parser == NULL)
822    {
823      _DBUS_ASSERT_ERROR_IS_SET (error);
824      goto failed;
825    }
826
827  if (!process_config_every_time (context, parser, TRUE, error))
828    {
829      _DBUS_ASSERT_ERROR_IS_SET (error);
830      goto failed;
831    }
832  if (!process_config_postinit (context, parser, error))
833    {
834      _DBUS_ASSERT_ERROR_IS_SET (error);
835      goto failed;
836    }
837  ret = TRUE;
838
839  bus_context_log_info (context, "Reloaded configuration");
840 failed:
841  if (!ret)
842    bus_context_log_info (context, "Unable to reload configuration: %s", error->message);
843  if (parser != NULL)
844    bus_config_parser_unref (parser);
845  return ret;
846}
847
848static void
849shutdown_server (BusContext *context,
850                 DBusServer *server)
851{
852  if (server == NULL ||
853      !dbus_server_get_is_connected (server))
854    return;
855
856  if (!dbus_server_set_watch_functions (server,
857                                        NULL, NULL, NULL,
858                                        context,
859                                        NULL))
860    _dbus_assert_not_reached ("setting watch functions to NULL failed");
861
862  if (!dbus_server_set_timeout_functions (server,
863                                          NULL, NULL, NULL,
864                                          context,
865                                          NULL))
866    _dbus_assert_not_reached ("setting timeout functions to NULL failed");
867
868  dbus_server_disconnect (server);
869}
870
871void
872bus_context_shutdown (BusContext  *context)
873{
874  DBusList *link;
875
876  link = _dbus_list_get_first_link (&context->servers);
877  while (link != NULL)
878    {
879      shutdown_server (context, link->data);
880
881      link = _dbus_list_get_next_link (&context->servers, link);
882    }
883}
884
885BusContext *
886bus_context_ref (BusContext *context)
887{
888  _dbus_assert (context->refcount > 0);
889  context->refcount += 1;
890
891  return context;
892}
893
894void
895bus_context_unref (BusContext *context)
896{
897  _dbus_assert (context->refcount > 0);
898  context->refcount -= 1;
899
900  if (context->refcount == 0)
901    {
902      DBusList *link;
903
904      _dbus_verbose ("Finalizing bus context %p\n", context);
905
906      bus_context_shutdown (context);
907
908      if (context->connections)
909        {
910          bus_connections_unref (context->connections);
911          context->connections = NULL;
912        }
913
914      if (context->registry)
915        {
916          bus_registry_unref (context->registry);
917          context->registry = NULL;
918        }
919
920      if (context->activation)
921        {
922          bus_activation_unref (context->activation);
923          context->activation = NULL;
924        }
925
926      link = _dbus_list_get_first_link (&context->servers);
927      while (link != NULL)
928        {
929          dbus_server_unref (link->data);
930
931          link = _dbus_list_get_next_link (&context->servers, link);
932        }
933      _dbus_list_clear (&context->servers);
934
935      if (context->policy)
936        {
937          bus_policy_unref (context->policy);
938          context->policy = NULL;
939        }
940
941      if (context->loop)
942        {
943          _dbus_loop_unref (context->loop);
944          context->loop = NULL;
945        }
946
947      if (context->matchmaker)
948        {
949          bus_matchmaker_unref (context->matchmaker);
950          context->matchmaker = NULL;
951        }
952
953      dbus_free (context->config_file);
954      dbus_free (context->type);
955      dbus_free (context->address);
956      dbus_free (context->user);
957      dbus_free (context->servicehelper);
958
959      if (context->pidfile)
960	{
961          DBusString u;
962          _dbus_string_init_const (&u, context->pidfile);
963
964          /* Deliberately ignore errors here, since there's not much
965	   * we can do about it, and we're exiting anyways.
966	   */
967	  _dbus_delete_file (&u, NULL);
968
969          dbus_free (context->pidfile);
970	}
971      dbus_free (context);
972
973      dbus_server_free_data_slot (&server_data_slot);
974    }
975}
976
977/* type may be NULL */
978const char*
979bus_context_get_type (BusContext *context)
980{
981  return context->type;
982}
983
984const char*
985bus_context_get_address (BusContext *context)
986{
987  return context->address;
988}
989
990const char*
991bus_context_get_servicehelper (BusContext *context)
992{
993  return context->servicehelper;
994}
995
996BusRegistry*
997bus_context_get_registry (BusContext  *context)
998{
999  return context->registry;
1000}
1001
1002BusConnections*
1003bus_context_get_connections (BusContext  *context)
1004{
1005  return context->connections;
1006}
1007
1008BusActivation*
1009bus_context_get_activation (BusContext  *context)
1010{
1011  return context->activation;
1012}
1013
1014BusMatchmaker*
1015bus_context_get_matchmaker (BusContext  *context)
1016{
1017  return context->matchmaker;
1018}
1019
1020DBusLoop*
1021bus_context_get_loop (BusContext *context)
1022{
1023  return context->loop;
1024}
1025
1026dbus_bool_t
1027bus_context_allow_unix_user (BusContext   *context,
1028                             unsigned long uid)
1029{
1030  return bus_policy_allow_unix_user (context->policy,
1031                                     uid);
1032}
1033
1034/* For now this is never actually called because the default
1035 * DBusConnection behavior of 'same user that owns the bus can connect'
1036 * is all it would do.
1037 */
1038dbus_bool_t
1039bus_context_allow_windows_user (BusContext       *context,
1040                                const char       *windows_sid)
1041{
1042  return bus_policy_allow_windows_user (context->policy,
1043                                        windows_sid);
1044}
1045
1046BusPolicy *
1047bus_context_get_policy (BusContext *context)
1048{
1049  return context->policy;
1050}
1051
1052BusClientPolicy*
1053bus_context_create_client_policy (BusContext      *context,
1054                                  DBusConnection  *connection,
1055                                  DBusError       *error)
1056{
1057  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
1058  return bus_policy_create_client_policy (context->policy, connection,
1059                                          error);
1060}
1061
1062int
1063bus_context_get_activation_timeout (BusContext *context)
1064{
1065
1066  return context->limits.activation_timeout;
1067}
1068
1069int
1070bus_context_get_auth_timeout (BusContext *context)
1071{
1072  return context->limits.auth_timeout;
1073}
1074
1075int
1076bus_context_get_max_completed_connections (BusContext *context)
1077{
1078  return context->limits.max_completed_connections;
1079}
1080
1081int
1082bus_context_get_max_incomplete_connections (BusContext *context)
1083{
1084  return context->limits.max_incomplete_connections;
1085}
1086
1087int
1088bus_context_get_max_connections_per_user (BusContext *context)
1089{
1090  return context->limits.max_connections_per_user;
1091}
1092
1093int
1094bus_context_get_max_pending_activations (BusContext *context)
1095{
1096  return context->limits.max_pending_activations;
1097}
1098
1099int
1100bus_context_get_max_services_per_connection (BusContext *context)
1101{
1102  return context->limits.max_services_per_connection;
1103}
1104
1105int
1106bus_context_get_max_match_rules_per_connection (BusContext *context)
1107{
1108  return context->limits.max_match_rules_per_connection;
1109}
1110
1111int
1112bus_context_get_max_replies_per_connection (BusContext *context)
1113{
1114  return context->limits.max_replies_per_connection;
1115}
1116
1117int
1118bus_context_get_reply_timeout (BusContext *context)
1119{
1120  return context->limits.reply_timeout;
1121}
1122
1123void
1124bus_context_log_info (BusContext *context, const char *msg, ...)
1125{
1126  va_list args;
1127
1128  va_start (args, msg);
1129
1130  if (context->syslog)
1131    _dbus_log_info (msg, args);
1132
1133  va_end (args);
1134}
1135
1136void
1137bus_context_log_security (BusContext *context, const char *msg, ...)
1138{
1139  va_list args;
1140
1141  va_start (args, msg);
1142
1143  if (context->syslog)
1144    _dbus_log_security (msg, args);
1145
1146  va_end (args);
1147}
1148
1149/*
1150 * addressed_recipient is the recipient specified in the message.
1151 *
1152 * proposed_recipient is the recipient we're considering sending
1153 * to right this second, and may be an eavesdropper.
1154 *
1155 * sender is the sender of the message.
1156 *
1157 * NULL for proposed_recipient or sender definitely means the bus driver.
1158 *
1159 * NULL for addressed_recipient may mean the bus driver, or may mean
1160 * no destination was specified in the message (e.g. a signal).
1161 */
1162dbus_bool_t
1163bus_context_check_security_policy (BusContext     *context,
1164                                   BusTransaction *transaction,
1165                                   DBusConnection *sender,
1166                                   DBusConnection *addressed_recipient,
1167                                   DBusConnection *proposed_recipient,
1168                                   DBusMessage    *message,
1169                                   DBusError      *error)
1170{
1171  const char *dest;
1172  BusClientPolicy *sender_policy;
1173  BusClientPolicy *recipient_policy;
1174  dbus_int32_t toggles;
1175  dbus_bool_t log;
1176  int type;
1177  dbus_bool_t requested_reply;
1178  const char *sender_name;
1179  const char *sender_loginfo;
1180  const char *proposed_recipient_loginfo;
1181
1182  type = dbus_message_get_type (message);
1183  dest = dbus_message_get_destination (message);
1184
1185  /* dispatch.c was supposed to ensure these invariants */
1186  _dbus_assert (dest != NULL ||
1187                type == DBUS_MESSAGE_TYPE_SIGNAL ||
1188                (sender == NULL && !bus_connection_is_active (proposed_recipient)));
1189  _dbus_assert (type == DBUS_MESSAGE_TYPE_SIGNAL ||
1190                addressed_recipient != NULL ||
1191                strcmp (dest, DBUS_SERVICE_DBUS) == 0);
1192
1193  /* Used in logging below */
1194  if (sender != NULL)
1195    {
1196      sender_name = bus_connection_get_name (sender);
1197      sender_loginfo = bus_connection_get_loginfo (sender);
1198    }
1199  else
1200    {
1201      sender_name = NULL;
1202      sender_loginfo = "(bus)";
1203    }
1204
1205  if (proposed_recipient != NULL)
1206    proposed_recipient_loginfo = bus_connection_get_loginfo (proposed_recipient);
1207  else
1208    proposed_recipient_loginfo = "bus";
1209
1210  switch (type)
1211    {
1212    case DBUS_MESSAGE_TYPE_METHOD_CALL:
1213    case DBUS_MESSAGE_TYPE_SIGNAL:
1214    case DBUS_MESSAGE_TYPE_METHOD_RETURN:
1215    case DBUS_MESSAGE_TYPE_ERROR:
1216      break;
1217
1218    default:
1219      _dbus_verbose ("security check disallowing message of unknown type %d\n",
1220                     type);
1221
1222      dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
1223                      "Message bus will not accept messages of unknown type\n");
1224
1225      return FALSE;
1226    }
1227
1228  requested_reply = FALSE;
1229
1230  if (sender != NULL)
1231    {
1232      /* First verify the SELinux access controls.  If allowed then
1233       * go on with the standard checks.
1234       */
1235      if (!bus_selinux_allows_send (sender, proposed_recipient,
1236				    dbus_message_type_to_string (dbus_message_get_type (message)),
1237				    dbus_message_get_interface (message),
1238				    dbus_message_get_member (message),
1239				    dbus_message_get_error_name (message),
1240				    dest ? dest : DBUS_SERVICE_DBUS, error))
1241        {
1242          if (error != NULL && !dbus_error_is_set (error))
1243            {
1244              dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
1245                              "An SELinux policy prevents this sender "
1246                              "from sending this message to this recipient "
1247                              "(rejected message had sender \"%s\" interface \"%s\" "
1248                              "member \"%s\" error name \"%s\" destination \"%s\")",
1249                              sender_name ? sender_name : "(unset)",
1250                              dbus_message_get_interface (message) ?
1251                              dbus_message_get_interface (message) : "(unset)",
1252                              dbus_message_get_member (message) ?
1253                              dbus_message_get_member (message) : "(unset)",
1254                              dbus_message_get_error_name (message) ?
1255                              dbus_message_get_error_name (message) : "(unset)",
1256                              dest ? dest : DBUS_SERVICE_DBUS);
1257              _dbus_verbose ("SELinux security check denying send to service\n");
1258            }
1259
1260          return FALSE;
1261        }
1262
1263      if (bus_connection_is_active (sender))
1264        {
1265          sender_policy = bus_connection_get_policy (sender);
1266          _dbus_assert (sender_policy != NULL);
1267
1268          /* Fill in requested_reply variable with TRUE if this is a
1269           * reply and the reply was pending.
1270           */
1271          if (dbus_message_get_reply_serial (message) != 0)
1272            {
1273              if (proposed_recipient != NULL /* not to the bus driver */ &&
1274                  addressed_recipient == proposed_recipient /* not eavesdropping */)
1275                {
1276                  DBusError error2;
1277
1278                  dbus_error_init (&error2);
1279                  requested_reply = bus_connections_check_reply (bus_connection_get_connections (sender),
1280                                                                 transaction,
1281                                                                 sender, addressed_recipient, message,
1282                                                                 &error2);
1283                  if (dbus_error_is_set (&error2))
1284                    {
1285                      dbus_move_error (&error2, error);
1286                      return FALSE;
1287                    }
1288                }
1289            }
1290        }
1291      else
1292        {
1293          /* Policy for inactive connections is that they can only send
1294           * the hello message to the bus driver
1295           */
1296          if (proposed_recipient == NULL &&
1297              dbus_message_is_method_call (message,
1298                                           DBUS_INTERFACE_DBUS,
1299                                           "Hello"))
1300            {
1301              _dbus_verbose ("security check allowing %s message\n",
1302                             "Hello");
1303              return TRUE;
1304            }
1305          else
1306            {
1307              _dbus_verbose ("security check disallowing non-%s message\n",
1308                             "Hello");
1309
1310              dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
1311                              "Client tried to send a message other than %s without being registered",
1312                              "Hello");
1313
1314              return FALSE;
1315            }
1316        }
1317    }
1318  else
1319    {
1320      sender_policy = NULL;
1321
1322      /* If the sender is the bus driver, we assume any reply was a
1323       * requested reply as bus driver won't send bogus ones
1324       */
1325      if (addressed_recipient == proposed_recipient /* not eavesdropping */ &&
1326          dbus_message_get_reply_serial (message) != 0)
1327        requested_reply = TRUE;
1328    }
1329
1330  _dbus_assert ((sender != NULL && sender_policy != NULL) ||
1331                (sender == NULL && sender_policy == NULL));
1332
1333  if (proposed_recipient != NULL)
1334    {
1335      /* only the bus driver can send to an inactive recipient (as it
1336       * owns no services, so other apps can't address it). Inactive
1337       * recipients can receive any message.
1338       */
1339      if (bus_connection_is_active (proposed_recipient))
1340        {
1341          recipient_policy = bus_connection_get_policy (proposed_recipient);
1342          _dbus_assert (recipient_policy != NULL);
1343        }
1344      else if (sender == NULL)
1345        {
1346          _dbus_verbose ("security check using NULL recipient policy for message from bus\n");
1347          recipient_policy = NULL;
1348        }
1349      else
1350        {
1351          _dbus_assert_not_reached ("a message was somehow sent to an inactive recipient from a source other than the message bus\n");
1352          recipient_policy = NULL;
1353        }
1354    }
1355  else
1356    recipient_policy = NULL;
1357
1358  _dbus_assert ((proposed_recipient != NULL && recipient_policy != NULL) ||
1359                (proposed_recipient != NULL && sender == NULL && recipient_policy == NULL) ||
1360                (proposed_recipient == NULL && recipient_policy == NULL));
1361
1362  log = FALSE;
1363  if (sender_policy &&
1364      !bus_client_policy_check_can_send (sender_policy,
1365                                         context->registry,
1366                                         requested_reply,
1367                                         proposed_recipient,
1368                                         message, &toggles, &log))
1369    {
1370      const char *msg = "Rejected send message, %d matched rules; "
1371                        "type=\"%s\", sender=\"%s\" (%s) interface=\"%s\" member=\"%s\" error name=\"%s\" requested_reply=%d destination=\"%s\" (%s))";
1372
1373      dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED, msg,
1374                      toggles,
1375                      dbus_message_type_to_string (dbus_message_get_type (message)),
1376                      sender_name ? sender_name : "(unset)",
1377                      sender_loginfo,
1378                      dbus_message_get_interface (message) ?
1379                      dbus_message_get_interface (message) : "(unset)",
1380                      dbus_message_get_member (message) ?
1381                      dbus_message_get_member (message) : "(unset)",
1382                      dbus_message_get_error_name (message) ?
1383                      dbus_message_get_error_name (message) : "(unset)",
1384                      requested_reply,
1385                      dest ? dest : DBUS_SERVICE_DBUS,
1386                      proposed_recipient_loginfo);
1387      /* Needs to be duplicated to avoid calling malloc and having to handle OOM */
1388      if (addressed_recipient == proposed_recipient)
1389        bus_context_log_security (context, msg,
1390                                  toggles,
1391                                  dbus_message_type_to_string (dbus_message_get_type (message)),
1392                                  sender_name ? sender_name : "(unset)",
1393                                  sender_loginfo,
1394                                  dbus_message_get_interface (message) ?
1395                                  dbus_message_get_interface (message) : "(unset)",
1396                                  dbus_message_get_member (message) ?
1397                                  dbus_message_get_member (message) : "(unset)",
1398                                  dbus_message_get_error_name (message) ?
1399                                  dbus_message_get_error_name (message) : "(unset)",
1400                                  requested_reply,
1401                                  dest ? dest : DBUS_SERVICE_DBUS,
1402                                  proposed_recipient_loginfo);
1403      _dbus_verbose ("security policy disallowing message due to sender policy\n");
1404      return FALSE;
1405    }
1406
1407  if (log)
1408    bus_context_log_security (context,
1409                              "Would reject message, %d matched rules; "
1410                              "type=\"%s\", sender=\"%s\" (%s) interface=\"%s\" member=\"%s\" error name=\"%s\" requested_reply=%d destination=\"%s\" (%s))",
1411                              toggles,
1412                              dbus_message_type_to_string (dbus_message_get_type (message)),
1413                              sender_name ? sender_name : "(unset)",
1414                              sender_loginfo,
1415                              dbus_message_get_interface (message) ?
1416                              dbus_message_get_interface (message) : "(unset)",
1417                              dbus_message_get_member (message) ?
1418                              dbus_message_get_member (message) : "(unset)",
1419                              dbus_message_get_error_name (message) ?
1420                              dbus_message_get_error_name (message) : "(unset)",
1421                              requested_reply,
1422                              dest ? dest : DBUS_SERVICE_DBUS,
1423                              proposed_recipient_loginfo);
1424
1425  if (recipient_policy &&
1426      !bus_client_policy_check_can_receive (recipient_policy,
1427                                            context->registry,
1428                                            requested_reply,
1429                                            sender,
1430                                            addressed_recipient, proposed_recipient,
1431                                            message, &toggles))
1432    {
1433      const char *msg = "Rejected receive message, %d matched rules; "
1434                        "type=\"%s\" sender=\"%s\" (%s) interface=\"%s\" member=\"%s\" error name=\"%s\" reply serial=%u requested_reply=%d destination=\"%s\" (%s))";
1435
1436      dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED, msg,
1437                      toggles,
1438                      dbus_message_type_to_string (dbus_message_get_type (message)),
1439                      sender_name ? sender_name : "(unset)",
1440                      sender_loginfo,
1441                      dbus_message_get_interface (message) ?
1442                      dbus_message_get_interface (message) : "(unset)",
1443                      dbus_message_get_member (message) ?
1444                      dbus_message_get_member (message) : "(unset)",
1445                      dbus_message_get_error_name (message) ?
1446                      dbus_message_get_error_name (message) : "(unset)",
1447                      dbus_message_get_reply_serial (message),
1448                      requested_reply,
1449                      dest ? dest : DBUS_SERVICE_DBUS,
1450                      proposed_recipient_loginfo);
1451      /* Needs to be duplicated to avoid calling malloc and having to handle OOM */
1452      if (addressed_recipient == proposed_recipient)
1453        bus_context_log_security (context, msg,
1454                                  toggles,
1455                                  dbus_message_type_to_string (dbus_message_get_type (message)),
1456                                  sender_name ? sender_name : "(unset)",
1457                                  sender_loginfo,
1458                                  dbus_message_get_interface (message) ?
1459                                  dbus_message_get_interface (message) : "(unset)",
1460                                  dbus_message_get_member (message) ?
1461                                  dbus_message_get_member (message) : "(unset)",
1462                                  dbus_message_get_error_name (message) ?
1463                                  dbus_message_get_error_name (message) : "(unset)",
1464                                  dbus_message_get_reply_serial (message),
1465                                  requested_reply,
1466                                  dest ? dest : DBUS_SERVICE_DBUS,
1467                                  proposed_recipient_loginfo);
1468      _dbus_verbose ("security policy disallowing message due to recipient policy\n");
1469      return FALSE;
1470    }
1471
1472  /* See if limits on size have been exceeded */
1473  if (proposed_recipient &&
1474      dbus_connection_get_outgoing_size (proposed_recipient) >
1475      context->limits.max_outgoing_bytes)
1476    {
1477      dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
1478                      "The destination service \"%s\" has a full message queue",
1479                      dest ? dest : (proposed_recipient ?
1480                                     bus_connection_get_name (proposed_recipient) :
1481                                     DBUS_SERVICE_DBUS));
1482      _dbus_verbose ("security policy disallowing message due to full message queue\n");
1483      return FALSE;
1484    }
1485
1486  /* Record that we will allow a reply here in the future (don't
1487   * bother if the recipient is the bus or this is an eavesdropping
1488   * connection). Only the addressed recipient may reply.
1489   */
1490  if (type == DBUS_MESSAGE_TYPE_METHOD_CALL &&
1491      sender &&
1492      addressed_recipient &&
1493      addressed_recipient == proposed_recipient && /* not eavesdropping */
1494      !bus_connections_expect_reply (bus_connection_get_connections (sender),
1495                                     transaction,
1496                                     sender, addressed_recipient,
1497                                     message, error))
1498    {
1499      _dbus_verbose ("Failed to record reply expectation or problem with the message expecting a reply\n");
1500      return FALSE;
1501    }
1502
1503  _dbus_verbose ("security policy allowing message\n");
1504  return TRUE;
1505}
1506