bus.c revision 37019e9d271390fa8c62c1aae62d30bb9068adaa 
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  unsigned int allow_anonymous : 1;
60};
61
62static dbus_int32_t server_data_slot = -1;
63
64typedef struct
65{
66  BusContext *context;
67} BusServerData;
68
69#define BUS_SERVER_DATA(server) (dbus_server_get_data ((server), server_data_slot))
70
71static BusContext*
72server_get_context (DBusServer *server)
73{
74  BusContext *context;
75  BusServerData *bd;
76
77  if (!dbus_server_allocate_data_slot (&server_data_slot))
78    return NULL;
79
80  bd = BUS_SERVER_DATA (server);
81  if (bd == NULL)
82    {
83      dbus_server_free_data_slot (&server_data_slot);
84      return NULL;
85    }
86
87  context = bd->context;
88
89  dbus_server_free_data_slot (&server_data_slot);
90
91  return context;
92}
93
94static dbus_bool_t
95server_watch_callback (DBusWatch     *watch,
96                       unsigned int   condition,
97                       void          *data)
98{
99  /* FIXME this can be done in dbus-mainloop.c
100   * if the code in activation.c for the babysitter
101   * watch handler is fixed.
102   */
103
104  return dbus_watch_handle (watch, condition);
105}
106
107static dbus_bool_t
108add_server_watch (DBusWatch  *watch,
109                  void       *data)
110{
111  DBusServer *server = data;
112  BusContext *context;
113
114  context = server_get_context (server);
115
116  return _dbus_loop_add_watch (context->loop,
117                               watch, server_watch_callback, server,
118                               NULL);
119}
120
121static void
122remove_server_watch (DBusWatch  *watch,
123                     void       *data)
124{
125  DBusServer *server = data;
126  BusContext *context;
127
128  context = server_get_context (server);
129
130  _dbus_loop_remove_watch (context->loop,
131                           watch, server_watch_callback, server);
132}
133
134
135static void
136server_timeout_callback (DBusTimeout   *timeout,
137                         void          *data)
138{
139  /* can return FALSE on OOM but we just let it fire again later */
140  dbus_timeout_handle (timeout);
141}
142
143static dbus_bool_t
144add_server_timeout (DBusTimeout *timeout,
145                    void        *data)
146{
147  DBusServer *server = data;
148  BusContext *context;
149
150  context = server_get_context (server);
151
152  return _dbus_loop_add_timeout (context->loop,
153                                 timeout, server_timeout_callback, server, NULL);
154}
155
156static void
157remove_server_timeout (DBusTimeout *timeout,
158                       void        *data)
159{
160  DBusServer *server = data;
161  BusContext *context;
162
163  context = server_get_context (server);
164
165  _dbus_loop_remove_timeout (context->loop,
166                             timeout, server_timeout_callback, server);
167}
168
169static void
170new_connection_callback (DBusServer     *server,
171                         DBusConnection *new_connection,
172                         void           *data)
173{
174  BusContext *context = data;
175
176  if (!bus_connections_setup_connection (context->connections, new_connection))
177    {
178      _dbus_verbose ("No memory to setup new connection\n");
179
180      /* if we don't do this, it will get unref'd without
181       * being disconnected... kind of strange really
182       * that we have to do this, people won't get it right
183       * in general.
184       */
185      dbus_connection_close (new_connection);
186    }
187
188  dbus_connection_set_max_received_size (new_connection,
189                                         context->limits.max_incoming_bytes);
190
191  dbus_connection_set_max_message_size (new_connection,
192                                        context->limits.max_message_size);
193
194  dbus_connection_set_max_received_unix_fds (new_connection,
195                                         context->limits.max_incoming_unix_fds);
196
197  dbus_connection_set_max_message_unix_fds (new_connection,
198                                        context->limits.max_message_unix_fds);
199
200  dbus_connection_set_allow_anonymous (new_connection,
201                                       context->allow_anonymous);
202
203  /* on OOM, we won't have ref'd the connection so it will die. */
204}
205
206static void
207free_server_data (void *data)
208{
209  BusServerData *bd = data;
210
211  dbus_free (bd);
212}
213
214static dbus_bool_t
215setup_server (BusContext *context,
216              DBusServer *server,
217              char      **auth_mechanisms,
218              DBusError  *error)
219{
220  BusServerData *bd;
221
222  bd = dbus_new0 (BusServerData, 1);
223  if (bd == NULL || !dbus_server_set_data (server,
224                                           server_data_slot,
225                                           bd, free_server_data))
226    {
227      dbus_free (bd);
228      BUS_SET_OOM (error);
229      return FALSE;
230    }
231
232  bd->context = context;
233
234  if (!dbus_server_set_auth_mechanisms (server, (const char**) auth_mechanisms))
235    {
236      BUS_SET_OOM (error);
237      return FALSE;
238    }
239
240  dbus_server_set_new_connection_function (server,
241                                           new_connection_callback,
242                                           context, NULL);
243
244  if (!dbus_server_set_watch_functions (server,
245                                        add_server_watch,
246                                        remove_server_watch,
247                                        NULL,
248                                        server,
249                                        NULL))
250    {
251      BUS_SET_OOM (error);
252      return FALSE;
253    }
254
255  if (!dbus_server_set_timeout_functions (server,
256                                          add_server_timeout,
257                                          remove_server_timeout,
258                                          NULL,
259                                          server, NULL))
260    {
261      BUS_SET_OOM (error);
262      return FALSE;
263    }
264
265  return TRUE;
266}
267
268/* This code only gets executed the first time the
269 * config files are parsed.  It is not executed
270 * when config files are reloaded.
271 */
272static dbus_bool_t
273process_config_first_time_only (BusContext      *context,
274				BusConfigParser *parser,
275				DBusError       *error)
276{
277  DBusList *link;
278  DBusList **addresses;
279  const char *user, *pidfile;
280  char **auth_mechanisms;
281  DBusList **auth_mechanisms_list;
282  int len;
283  dbus_bool_t retval;
284
285  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
286
287  retval = FALSE;
288  auth_mechanisms = NULL;
289
290  /* Check for an existing pid file. Of course this is a race;
291   * we'd have to use fcntl() locks on the pid file to
292   * avoid that. But we want to check for the pid file
293   * before overwriting any existing sockets, etc.
294   */
295  pidfile = bus_config_parser_get_pidfile (parser);
296  if (pidfile != NULL)
297    {
298      DBusString u;
299      DBusStat stbuf;
300
301      _dbus_string_init_const (&u, pidfile);
302
303      if (_dbus_stat (&u, &stbuf, NULL))
304	{
305	  dbus_set_error (error, DBUS_ERROR_FAILED,
306			  "The pid file \"%s\" exists, if the message bus is not running, remove this file",
307			  pidfile);
308	  goto failed;
309	}
310    }
311
312  /* keep around the pid filename so we can delete it later */
313  context->pidfile = _dbus_strdup (pidfile);
314
315  /* Build an array of auth mechanisms */
316
317  auth_mechanisms_list = bus_config_parser_get_mechanisms (parser);
318  len = _dbus_list_get_length (auth_mechanisms_list);
319
320  if (len > 0)
321    {
322      int i;
323
324      auth_mechanisms = dbus_new0 (char*, len + 1);
325      if (auth_mechanisms == NULL)
326	{
327	  BUS_SET_OOM (error);
328	  goto failed;
329	}
330
331      i = 0;
332      link = _dbus_list_get_first_link (auth_mechanisms_list);
333      while (link != NULL)
334        {
335          auth_mechanisms[i] = _dbus_strdup (link->data);
336          if (auth_mechanisms[i] == NULL)
337	    {
338	      BUS_SET_OOM (error);
339	      goto failed;
340	    }
341          link = _dbus_list_get_next_link (auth_mechanisms_list, link);
342        }
343    }
344  else
345    {
346      auth_mechanisms = NULL;
347    }
348
349  /* Listen on our addresses */
350
351  addresses = bus_config_parser_get_addresses (parser);
352
353  link = _dbus_list_get_first_link (addresses);
354  while (link != NULL)
355    {
356      DBusServer *server;
357
358      server = dbus_server_listen (link->data, error);
359      if (server == NULL)
360	{
361	  _DBUS_ASSERT_ERROR_IS_SET (error);
362	  goto failed;
363	}
364      else if (!setup_server (context, server, auth_mechanisms, error))
365	{
366	  _DBUS_ASSERT_ERROR_IS_SET (error);
367	  goto failed;
368	}
369
370      if (!_dbus_list_append (&context->servers, server))
371        {
372          BUS_SET_OOM (error);
373          goto failed;
374        }
375
376      link = _dbus_list_get_next_link (addresses, link);
377    }
378
379  /* note that type may be NULL */
380  context->type = _dbus_strdup (bus_config_parser_get_type (parser));
381  if (bus_config_parser_get_type (parser) != NULL && context->type == NULL)
382    {
383      BUS_SET_OOM (error);
384      goto failed;
385    }
386
387  user = bus_config_parser_get_user (parser);
388  if (user != NULL)
389    {
390      context->user = _dbus_strdup (user);
391      if (context->user == NULL)
392	{
393	  BUS_SET_OOM (error);
394	  goto failed;
395	}
396    }
397
398  context->fork = bus_config_parser_get_fork (parser);
399  context->syslog = bus_config_parser_get_syslog (parser);
400  context->keep_umask = bus_config_parser_get_keep_umask (parser);
401  context->allow_anonymous = bus_config_parser_get_allow_anonymous (parser);
402
403  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
404  retval = TRUE;
405
406 failed:
407  dbus_free_string_array (auth_mechanisms);
408  return retval;
409}
410
411/* This code gets executed every time the config files
412 * are parsed: both during BusContext construction
413 * and on reloads. This function is slightly screwy
414 * since it can do a "half reload" in out-of-memory
415 * situations. Realistically, unlikely to ever matter.
416 */
417static dbus_bool_t
418process_config_every_time (BusContext      *context,
419			   BusConfigParser *parser,
420			   dbus_bool_t      is_reload,
421			   DBusError       *error)
422{
423  DBusString full_address;
424  DBusList *link;
425  DBusList **dirs;
426  BusActivation *new_activation;
427  char *addr;
428  const char *servicehelper;
429  char *s;
430
431  dbus_bool_t retval;
432
433  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
434
435  addr = NULL;
436  retval = FALSE;
437
438  if (!_dbus_string_init (&full_address))
439    {
440      BUS_SET_OOM (error);
441      return FALSE;
442    }
443
444  /* get our limits and timeout lengths */
445  bus_config_parser_get_limits (parser, &context->limits);
446
447  context->policy = bus_config_parser_steal_policy (parser);
448  _dbus_assert (context->policy != NULL);
449
450  /* We have to build the address backward, so that
451   * <listen> later in the config file have priority
452   */
453  link = _dbus_list_get_last_link (&context->servers);
454  while (link != NULL)
455    {
456      addr = dbus_server_get_address (link->data);
457      if (addr == NULL)
458        {
459          BUS_SET_OOM (error);
460          goto failed;
461        }
462
463      if (_dbus_string_get_length (&full_address) > 0)
464        {
465          if (!_dbus_string_append (&full_address, ";"))
466            {
467              BUS_SET_OOM (error);
468              goto failed;
469            }
470        }
471
472      if (!_dbus_string_append (&full_address, addr))
473        {
474          BUS_SET_OOM (error);
475          goto failed;
476        }
477
478      dbus_free (addr);
479      addr = NULL;
480
481      link = _dbus_list_get_prev_link (&context->servers, link);
482    }
483
484  if (is_reload)
485    dbus_free (context->address);
486
487  if (!_dbus_string_copy_data (&full_address, &context->address))
488    {
489      BUS_SET_OOM (error);
490      goto failed;
491    }
492
493  /* get the service directories */
494  dirs = bus_config_parser_get_service_dirs (parser);
495
496  /* and the service helper */
497  servicehelper = bus_config_parser_get_servicehelper (parser);
498
499  s = _dbus_strdup(servicehelper);
500  if (s == NULL && servicehelper != NULL)
501    {
502      BUS_SET_OOM (error);
503      goto failed;
504    }
505  else
506    {
507      dbus_free(context->servicehelper);
508      context->servicehelper = s;
509    }
510
511  /* Create activation subsystem */
512  new_activation = bus_activation_new (context, &full_address,
513                                       dirs, error);
514  if (new_activation == NULL)
515    {
516      _DBUS_ASSERT_ERROR_IS_SET (error);
517      goto failed;
518    }
519
520  if (is_reload)
521    bus_activation_unref (context->activation);
522
523  context->activation = new_activation;
524
525  /* Drop existing conf-dir watches (if applicable) */
526
527  if (is_reload)
528    bus_drop_all_directory_watches ();
529
530  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
531  retval = TRUE;
532
533 failed:
534  _dbus_string_free (&full_address);
535
536  if (addr)
537    dbus_free (addr);
538
539  return retval;
540}
541
542static dbus_bool_t
543process_config_postinit (BusContext      *context,
544			 BusConfigParser *parser,
545			 DBusError       *error)
546{
547  DBusHashTable *service_context_table;
548
549  service_context_table = bus_config_parser_steal_service_context_table (parser);
550  if (!bus_registry_set_service_context_table (context->registry,
551					       service_context_table))
552    {
553      BUS_SET_OOM (error);
554      return FALSE;
555    }
556
557  _dbus_hash_table_unref (service_context_table);
558
559  /* Watch all conf directories */
560  _dbus_list_foreach (bus_config_parser_get_conf_dirs (parser),
561		      (DBusForeachFunction) bus_watch_directory,
562		      context);
563
564  return TRUE;
565}
566
567BusContext*
568bus_context_new (const DBusString *config_file,
569                 ForceForkSetting  force_fork,
570                 DBusPipe         *print_addr_pipe,
571                 DBusPipe         *print_pid_pipe,
572                 DBusError        *error)
573{
574  BusContext *context;
575  BusConfigParser *parser;
576
577  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
578
579  context = NULL;
580  parser = NULL;
581
582  if (!dbus_server_allocate_data_slot (&server_data_slot))
583    {
584      BUS_SET_OOM (error);
585      return NULL;
586    }
587
588  context = dbus_new0 (BusContext, 1);
589  if (context == NULL)
590    {
591      BUS_SET_OOM (error);
592      goto failed;
593    }
594  context->refcount = 1;
595
596  _dbus_generate_uuid (&context->uuid);
597
598  if (!_dbus_string_copy_data (config_file, &context->config_file))
599    {
600      BUS_SET_OOM (error);
601      goto failed;
602    }
603
604  context->loop = _dbus_loop_new ();
605  if (context->loop == NULL)
606    {
607      BUS_SET_OOM (error);
608      goto failed;
609    }
610
611  context->registry = bus_registry_new (context);
612  if (context->registry == NULL)
613    {
614      BUS_SET_OOM (error);
615      goto failed;
616    }
617
618  parser = bus_config_load (config_file, TRUE, NULL, error);
619  if (parser == NULL)
620    {
621      _DBUS_ASSERT_ERROR_IS_SET (error);
622      goto failed;
623    }
624
625  if (!process_config_first_time_only (context, parser, error))
626    {
627      _DBUS_ASSERT_ERROR_IS_SET (error);
628      goto failed;
629    }
630  if (!process_config_every_time (context, parser, FALSE, error))
631    {
632      _DBUS_ASSERT_ERROR_IS_SET (error);
633      goto failed;
634    }
635
636  /* we need another ref of the server data slot for the context
637   * to own
638   */
639  if (!dbus_server_allocate_data_slot (&server_data_slot))
640    _dbus_assert_not_reached ("second ref of server data slot failed");
641
642  /* Note that we don't know whether the print_addr_pipe is
643   * one of the sockets we're using to listen on, or some
644   * other random thing. But I think the answer is "don't do
645   * that then"
646   */
647  if (print_addr_pipe != NULL && _dbus_pipe_is_valid (print_addr_pipe))
648    {
649      DBusString addr;
650      const char *a = bus_context_get_address (context);
651      int bytes;
652
653      _dbus_assert (a != NULL);
654      if (!_dbus_string_init (&addr))
655        {
656          BUS_SET_OOM (error);
657          goto failed;
658        }
659
660      if (!_dbus_string_append (&addr, a) ||
661          !_dbus_string_append (&addr, "\n"))
662        {
663          _dbus_string_free (&addr);
664          BUS_SET_OOM (error);
665          goto failed;
666        }
667
668      bytes = _dbus_string_get_length (&addr);
669      if (_dbus_pipe_write (print_addr_pipe, &addr, 0, bytes, error) != bytes)
670        {
671          /* pipe write returns an error on failure but not short write */
672          if (error != NULL && !dbus_error_is_set (error))
673            {
674              dbus_set_error (error, DBUS_ERROR_FAILED,
675                              "Printing message bus address: did not write all bytes\n");
676            }
677          _dbus_string_free (&addr);
678          goto failed;
679        }
680
681      if (!_dbus_pipe_is_stdout_or_stderr (print_addr_pipe))
682        _dbus_pipe_close (print_addr_pipe, NULL);
683
684      _dbus_string_free (&addr);
685    }
686
687  context->connections = bus_connections_new (context);
688  if (context->connections == NULL)
689    {
690      BUS_SET_OOM (error);
691      goto failed;
692    }
693
694  context->matchmaker = bus_matchmaker_new ();
695  if (context->matchmaker == NULL)
696    {
697      BUS_SET_OOM (error);
698      goto failed;
699    }
700
701  /* check user before we fork */
702  if (context->user != NULL)
703    {
704      if (!_dbus_verify_daemon_user (context->user))
705        {
706          dbus_set_error (error, DBUS_ERROR_FAILED,
707                          "Could not get UID and GID for username \"%s\"",
708                          context->user);
709          goto failed;
710        }
711    }
712
713  /* Now become a daemon if appropriate and write out pid file in any case */
714  {
715    DBusString u;
716
717    if (context->pidfile)
718      _dbus_string_init_const (&u, context->pidfile);
719
720    if ((force_fork != FORK_NEVER && context->fork) || force_fork == FORK_ALWAYS)
721      {
722        _dbus_verbose ("Forking and becoming daemon\n");
723
724        if (!_dbus_become_daemon (context->pidfile ? &u : NULL,
725                                  print_pid_pipe,
726                                  error,
727                                  context->keep_umask))
728          {
729            _DBUS_ASSERT_ERROR_IS_SET (error);
730            goto failed;
731          }
732      }
733    else
734      {
735        _dbus_verbose ("Fork not requested\n");
736
737        /* Need to write PID file and to PID pipe for ourselves,
738         * not for the child process. This is a no-op if the pidfile
739         * is NULL and print_pid_pipe is NULL.
740         */
741        if (!_dbus_write_pid_to_file_and_pipe (context->pidfile ? &u : NULL,
742                                               print_pid_pipe,
743                                               _dbus_getpid (),
744                                               error))
745          {
746            _DBUS_ASSERT_ERROR_IS_SET (error);
747            goto failed;
748          }
749      }
750  }
751
752  if (print_pid_pipe && _dbus_pipe_is_valid (print_pid_pipe) &&
753      !_dbus_pipe_is_stdout_or_stderr (print_pid_pipe))
754    _dbus_pipe_close (print_pid_pipe, NULL);
755
756  if (!bus_selinux_full_init ())
757    {
758      _dbus_warn ("SELinux initialization failed\n");
759    }
760
761  if (!process_config_postinit (context, parser, error))
762    {
763      _DBUS_ASSERT_ERROR_IS_SET (error);
764      goto failed;
765    }
766
767  if (parser != NULL)
768    {
769      bus_config_parser_unref (parser);
770      parser = NULL;
771    }
772
773  /* Here we change our credentials if required,
774   * as soon as we've set up our sockets and pidfile
775   */
776  if (context->user != NULL)
777    {
778      if (!_dbus_change_to_daemon_user (context->user, error))
779	{
780	  _DBUS_ASSERT_ERROR_IS_SET (error);
781	  goto failed;
782	}
783
784#ifdef HAVE_SELINUX
785      /* FIXME - why not just put this in full_init() below? */
786      bus_selinux_audit_init ();
787#endif
788    }
789
790  dbus_server_free_data_slot (&server_data_slot);
791
792  return context;
793
794 failed:
795  if (parser != NULL)
796    bus_config_parser_unref (parser);
797  if (context != NULL)
798    bus_context_unref (context);
799
800  if (server_data_slot >= 0)
801    dbus_server_free_data_slot (&server_data_slot);
802
803  return NULL;
804}
805
806dbus_bool_t
807bus_context_get_id (BusContext       *context,
808                    DBusString       *uuid)
809{
810  return _dbus_uuid_encode (&context->uuid, uuid);
811}
812
813dbus_bool_t
814bus_context_reload_config (BusContext *context,
815			   DBusError  *error)
816{
817  BusConfigParser *parser;
818  DBusString config_file;
819  dbus_bool_t ret;
820
821  /* Flush the user database cache */
822  _dbus_flush_caches ();
823
824  ret = FALSE;
825  _dbus_string_init_const (&config_file, context->config_file);
826  parser = bus_config_load (&config_file, TRUE, NULL, error);
827  if (parser == NULL)
828    {
829      _DBUS_ASSERT_ERROR_IS_SET (error);
830      goto failed;
831    }
832
833  if (!process_config_every_time (context, parser, TRUE, error))
834    {
835      _DBUS_ASSERT_ERROR_IS_SET (error);
836      goto failed;
837    }
838  if (!process_config_postinit (context, parser, error))
839    {
840      _DBUS_ASSERT_ERROR_IS_SET (error);
841      goto failed;
842    }
843  ret = TRUE;
844
845  bus_context_log_info (context, "Reloaded configuration");
846 failed:
847  if (!ret)
848    bus_context_log_info (context, "Unable to reload configuration: %s", error->message);
849  if (parser != NULL)
850    bus_config_parser_unref (parser);
851  return ret;
852}
853
854static void
855shutdown_server (BusContext *context,
856                 DBusServer *server)
857{
858  if (server == NULL ||
859      !dbus_server_get_is_connected (server))
860    return;
861
862  if (!dbus_server_set_watch_functions (server,
863                                        NULL, NULL, NULL,
864                                        context,
865                                        NULL))
866    _dbus_assert_not_reached ("setting watch functions to NULL failed");
867
868  if (!dbus_server_set_timeout_functions (server,
869                                          NULL, NULL, NULL,
870                                          context,
871                                          NULL))
872    _dbus_assert_not_reached ("setting timeout functions to NULL failed");
873
874  dbus_server_disconnect (server);
875}
876
877void
878bus_context_shutdown (BusContext  *context)
879{
880  DBusList *link;
881
882  link = _dbus_list_get_first_link (&context->servers);
883  while (link != NULL)
884    {
885      shutdown_server (context, link->data);
886
887      link = _dbus_list_get_next_link (&context->servers, link);
888    }
889}
890
891BusContext *
892bus_context_ref (BusContext *context)
893{
894  _dbus_assert (context->refcount > 0);
895  context->refcount += 1;
896
897  return context;
898}
899
900void
901bus_context_unref (BusContext *context)
902{
903  _dbus_assert (context->refcount > 0);
904  context->refcount -= 1;
905
906  if (context->refcount == 0)
907    {
908      DBusList *link;
909
910      _dbus_verbose ("Finalizing bus context %p\n", context);
911
912      bus_context_shutdown (context);
913
914      if (context->connections)
915        {
916          bus_connections_unref (context->connections);
917          context->connections = NULL;
918        }
919
920      if (context->registry)
921        {
922          bus_registry_unref (context->registry);
923          context->registry = NULL;
924        }
925
926      if (context->activation)
927        {
928          bus_activation_unref (context->activation);
929          context->activation = NULL;
930        }
931
932      link = _dbus_list_get_first_link (&context->servers);
933      while (link != NULL)
934        {
935          dbus_server_unref (link->data);
936
937          link = _dbus_list_get_next_link (&context->servers, link);
938        }
939      _dbus_list_clear (&context->servers);
940
941      if (context->policy)
942        {
943          bus_policy_unref (context->policy);
944          context->policy = NULL;
945        }
946
947      if (context->loop)
948        {
949          _dbus_loop_unref (context->loop);
950          context->loop = NULL;
951        }
952
953      if (context->matchmaker)
954        {
955          bus_matchmaker_unref (context->matchmaker);
956          context->matchmaker = NULL;
957        }
958
959      dbus_free (context->config_file);
960      dbus_free (context->type);
961      dbus_free (context->address);
962      dbus_free (context->user);
963      dbus_free (context->servicehelper);
964
965      if (context->pidfile)
966	{
967          DBusString u;
968          _dbus_string_init_const (&u, context->pidfile);
969
970          /* Deliberately ignore errors here, since there's not much
971	   * we can do about it, and we're exiting anyways.
972	   */
973	  _dbus_delete_file (&u, NULL);
974
975          dbus_free (context->pidfile);
976	}
977      dbus_free (context);
978
979      dbus_server_free_data_slot (&server_data_slot);
980    }
981}
982
983/* type may be NULL */
984const char*
985bus_context_get_type (BusContext *context)
986{
987  return context->type;
988}
989
990const char*
991bus_context_get_address (BusContext *context)
992{
993  return context->address;
994}
995
996const char*
997bus_context_get_servicehelper (BusContext *context)
998{
999  return context->servicehelper;
1000}
1001
1002BusRegistry*
1003bus_context_get_registry (BusContext  *context)
1004{
1005  return context->registry;
1006}
1007
1008BusConnections*
1009bus_context_get_connections (BusContext  *context)
1010{
1011  return context->connections;
1012}
1013
1014BusActivation*
1015bus_context_get_activation (BusContext  *context)
1016{
1017  return context->activation;
1018}
1019
1020BusMatchmaker*
1021bus_context_get_matchmaker (BusContext  *context)
1022{
1023  return context->matchmaker;
1024}
1025
1026DBusLoop*
1027bus_context_get_loop (BusContext *context)
1028{
1029  return context->loop;
1030}
1031
1032dbus_bool_t
1033bus_context_allow_unix_user (BusContext   *context,
1034                             unsigned long uid)
1035{
1036  return bus_policy_allow_unix_user (context->policy,
1037                                     uid);
1038}
1039
1040/* For now this is never actually called because the default
1041 * DBusConnection behavior of 'same user that owns the bus can connect'
1042 * is all it would do.
1043 */
1044dbus_bool_t
1045bus_context_allow_windows_user (BusContext       *context,
1046                                const char       *windows_sid)
1047{
1048  return bus_policy_allow_windows_user (context->policy,
1049                                        windows_sid);
1050}
1051
1052BusPolicy *
1053bus_context_get_policy (BusContext *context)
1054{
1055  return context->policy;
1056}
1057
1058BusClientPolicy*
1059bus_context_create_client_policy (BusContext      *context,
1060                                  DBusConnection  *connection,
1061                                  DBusError       *error)
1062{
1063  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
1064  return bus_policy_create_client_policy (context->policy, connection,
1065                                          error);
1066}
1067
1068int
1069bus_context_get_activation_timeout (BusContext *context)
1070{
1071
1072  return context->limits.activation_timeout;
1073}
1074
1075int
1076bus_context_get_auth_timeout (BusContext *context)
1077{
1078  return context->limits.auth_timeout;
1079}
1080
1081int
1082bus_context_get_max_completed_connections (BusContext *context)
1083{
1084  return context->limits.max_completed_connections;
1085}
1086
1087int
1088bus_context_get_max_incomplete_connections (BusContext *context)
1089{
1090  return context->limits.max_incomplete_connections;
1091}
1092
1093int
1094bus_context_get_max_connections_per_user (BusContext *context)
1095{
1096  return context->limits.max_connections_per_user;
1097}
1098
1099int
1100bus_context_get_max_pending_activations (BusContext *context)
1101{
1102  return context->limits.max_pending_activations;
1103}
1104
1105int
1106bus_context_get_max_services_per_connection (BusContext *context)
1107{
1108  return context->limits.max_services_per_connection;
1109}
1110
1111int
1112bus_context_get_max_match_rules_per_connection (BusContext *context)
1113{
1114  return context->limits.max_match_rules_per_connection;
1115}
1116
1117int
1118bus_context_get_max_replies_per_connection (BusContext *context)
1119{
1120  return context->limits.max_replies_per_connection;
1121}
1122
1123int
1124bus_context_get_reply_timeout (BusContext *context)
1125{
1126  return context->limits.reply_timeout;
1127}
1128
1129void
1130bus_context_log_info (BusContext *context, const char *msg, ...)
1131{
1132  va_list args;
1133
1134  va_start (args, msg);
1135
1136  if (context->syslog)
1137    _dbus_log_info (msg, args);
1138
1139  va_end (args);
1140}
1141
1142void
1143bus_context_log_security (BusContext *context, const char *msg, ...)
1144{
1145  va_list args;
1146
1147  va_start (args, msg);
1148
1149  if (context->syslog)
1150    _dbus_log_security (msg, args);
1151
1152  va_end (args);
1153}
1154
1155/*
1156 * addressed_recipient is the recipient specified in the message.
1157 *
1158 * proposed_recipient is the recipient we're considering sending
1159 * to right this second, and may be an eavesdropper.
1160 *
1161 * sender is the sender of the message.
1162 *
1163 * NULL for proposed_recipient or sender definitely means the bus driver.
1164 *
1165 * NULL for addressed_recipient may mean the bus driver, or may mean
1166 * no destination was specified in the message (e.g. a signal).
1167 */
1168dbus_bool_t
1169bus_context_check_security_policy (BusContext     *context,
1170                                   BusTransaction *transaction,
1171                                   DBusConnection *sender,
1172                                   DBusConnection *addressed_recipient,
1173                                   DBusConnection *proposed_recipient,
1174                                   DBusMessage    *message,
1175                                   DBusError      *error)
1176{
1177  const char *dest;
1178  BusClientPolicy *sender_policy;
1179  BusClientPolicy *recipient_policy;
1180  dbus_int32_t toggles;
1181  dbus_bool_t log;
1182  int type;
1183  dbus_bool_t requested_reply;
1184  const char *sender_name;
1185  const char *sender_loginfo;
1186  const char *proposed_recipient_loginfo;
1187
1188  type = dbus_message_get_type (message);
1189  dest = dbus_message_get_destination (message);
1190
1191  /* dispatch.c was supposed to ensure these invariants */
1192  _dbus_assert (dest != NULL ||
1193                type == DBUS_MESSAGE_TYPE_SIGNAL ||
1194                (sender == NULL && !bus_connection_is_active (proposed_recipient)));
1195  _dbus_assert (type == DBUS_MESSAGE_TYPE_SIGNAL ||
1196                addressed_recipient != NULL ||
1197                strcmp (dest, DBUS_SERVICE_DBUS) == 0);
1198
1199  /* Used in logging below */
1200  if (sender != NULL)
1201    {
1202      sender_name = bus_connection_get_name (sender);
1203      sender_loginfo = bus_connection_get_loginfo (sender);
1204    }
1205  else
1206    {
1207      sender_name = NULL;
1208      sender_loginfo = "(bus)";
1209    }
1210
1211  if (proposed_recipient != NULL)
1212    proposed_recipient_loginfo = bus_connection_get_loginfo (proposed_recipient);
1213  else
1214    proposed_recipient_loginfo = "bus";
1215
1216  switch (type)
1217    {
1218    case DBUS_MESSAGE_TYPE_METHOD_CALL:
1219    case DBUS_MESSAGE_TYPE_SIGNAL:
1220    case DBUS_MESSAGE_TYPE_METHOD_RETURN:
1221    case DBUS_MESSAGE_TYPE_ERROR:
1222      break;
1223
1224    default:
1225      _dbus_verbose ("security check disallowing message of unknown type %d\n",
1226                     type);
1227
1228      dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
1229                      "Message bus will not accept messages of unknown type\n");
1230
1231      return FALSE;
1232    }
1233
1234  requested_reply = FALSE;
1235
1236  if (sender != NULL)
1237    {
1238      /* First verify the SELinux access controls.  If allowed then
1239       * go on with the standard checks.
1240       */
1241      if (!bus_selinux_allows_send (sender, proposed_recipient,
1242				    dbus_message_type_to_string (dbus_message_get_type (message)),
1243				    dbus_message_get_interface (message),
1244				    dbus_message_get_member (message),
1245				    dbus_message_get_error_name (message),
1246				    dest ? dest : DBUS_SERVICE_DBUS, error))
1247        {
1248          if (error != NULL && !dbus_error_is_set (error))
1249            {
1250              dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
1251                              "An SELinux policy prevents this sender "
1252                              "from sending this message to this recipient "
1253                              "(rejected message had sender \"%s\" interface \"%s\" "
1254                              "member \"%s\" error name \"%s\" destination \"%s\")",
1255                              sender_name ? sender_name : "(unset)",
1256                              dbus_message_get_interface (message) ?
1257                              dbus_message_get_interface (message) : "(unset)",
1258                              dbus_message_get_member (message) ?
1259                              dbus_message_get_member (message) : "(unset)",
1260                              dbus_message_get_error_name (message) ?
1261                              dbus_message_get_error_name (message) : "(unset)",
1262                              dest ? dest : DBUS_SERVICE_DBUS);
1263              _dbus_verbose ("SELinux security check denying send to service\n");
1264            }
1265
1266          return FALSE;
1267        }
1268
1269      if (bus_connection_is_active (sender))
1270        {
1271          sender_policy = bus_connection_get_policy (sender);
1272          _dbus_assert (sender_policy != NULL);
1273
1274          /* Fill in requested_reply variable with TRUE if this is a
1275           * reply and the reply was pending.
1276           */
1277          if (dbus_message_get_reply_serial (message) != 0)
1278            {
1279              if (proposed_recipient != NULL /* not to the bus driver */ &&
1280                  addressed_recipient == proposed_recipient /* not eavesdropping */)
1281                {
1282                  DBusError error2;
1283
1284                  dbus_error_init (&error2);
1285                  requested_reply = bus_connections_check_reply (bus_connection_get_connections (sender),
1286                                                                 transaction,
1287                                                                 sender, addressed_recipient, message,
1288                                                                 &error2);
1289                  if (dbus_error_is_set (&error2))
1290                    {
1291                      dbus_move_error (&error2, error);
1292                      return FALSE;
1293                    }
1294                }
1295            }
1296        }
1297      else
1298        {
1299          /* Policy for inactive connections is that they can only send
1300           * the hello message to the bus driver
1301           */
1302          if (proposed_recipient == NULL &&
1303              dbus_message_is_method_call (message,
1304                                           DBUS_INTERFACE_DBUS,
1305                                           "Hello"))
1306            {
1307              _dbus_verbose ("security check allowing %s message\n",
1308                             "Hello");
1309              return TRUE;
1310            }
1311          else
1312            {
1313              _dbus_verbose ("security check disallowing non-%s message\n",
1314                             "Hello");
1315
1316              dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
1317                              "Client tried to send a message other than %s without being registered",
1318                              "Hello");
1319
1320              return FALSE;
1321            }
1322        }
1323    }
1324  else
1325    {
1326      sender_policy = NULL;
1327
1328      /* If the sender is the bus driver, we assume any reply was a
1329       * requested reply as bus driver won't send bogus ones
1330       */
1331      if (addressed_recipient == proposed_recipient /* not eavesdropping */ &&
1332          dbus_message_get_reply_serial (message) != 0)
1333        requested_reply = TRUE;
1334    }
1335
1336  _dbus_assert ((sender != NULL && sender_policy != NULL) ||
1337                (sender == NULL && sender_policy == NULL));
1338
1339  if (proposed_recipient != NULL)
1340    {
1341      /* only the bus driver can send to an inactive recipient (as it
1342       * owns no services, so other apps can't address it). Inactive
1343       * recipients can receive any message.
1344       */
1345      if (bus_connection_is_active (proposed_recipient))
1346        {
1347          recipient_policy = bus_connection_get_policy (proposed_recipient);
1348          _dbus_assert (recipient_policy != NULL);
1349        }
1350      else if (sender == NULL)
1351        {
1352          _dbus_verbose ("security check using NULL recipient policy for message from bus\n");
1353          recipient_policy = NULL;
1354        }
1355      else
1356        {
1357          _dbus_assert_not_reached ("a message was somehow sent to an inactive recipient from a source other than the message bus\n");
1358          recipient_policy = NULL;
1359        }
1360    }
1361  else
1362    recipient_policy = NULL;
1363
1364  _dbus_assert ((proposed_recipient != NULL && recipient_policy != NULL) ||
1365                (proposed_recipient != NULL && sender == NULL && recipient_policy == NULL) ||
1366                (proposed_recipient == NULL && recipient_policy == NULL));
1367
1368  log = FALSE;
1369  if (sender_policy &&
1370      !bus_client_policy_check_can_send (sender_policy,
1371                                         context->registry,
1372                                         requested_reply,
1373                                         proposed_recipient,
1374                                         message, &toggles, &log))
1375    {
1376      const char *msg = "Rejected send message, %d matched rules; "
1377                        "type=\"%s\", sender=\"%s\" (%s) interface=\"%s\" member=\"%s\" error name=\"%s\" requested_reply=%d destination=\"%s\" (%s))";
1378
1379      dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED, msg,
1380                      toggles,
1381                      dbus_message_type_to_string (dbus_message_get_type (message)),
1382                      sender_name ? sender_name : "(unset)",
1383                      sender_loginfo,
1384                      dbus_message_get_interface (message) ?
1385                      dbus_message_get_interface (message) : "(unset)",
1386                      dbus_message_get_member (message) ?
1387                      dbus_message_get_member (message) : "(unset)",
1388                      dbus_message_get_error_name (message) ?
1389                      dbus_message_get_error_name (message) : "(unset)",
1390                      requested_reply,
1391                      dest ? dest : DBUS_SERVICE_DBUS,
1392                      proposed_recipient_loginfo);
1393      /* Needs to be duplicated to avoid calling malloc and having to handle OOM */
1394      if (addressed_recipient == proposed_recipient)
1395        bus_context_log_security (context, msg,
1396                                  toggles,
1397                                  dbus_message_type_to_string (dbus_message_get_type (message)),
1398                                  sender_name ? sender_name : "(unset)",
1399                                  sender_loginfo,
1400                                  dbus_message_get_interface (message) ?
1401                                  dbus_message_get_interface (message) : "(unset)",
1402                                  dbus_message_get_member (message) ?
1403                                  dbus_message_get_member (message) : "(unset)",
1404                                  dbus_message_get_error_name (message) ?
1405                                  dbus_message_get_error_name (message) : "(unset)",
1406                                  requested_reply,
1407                                  dest ? dest : DBUS_SERVICE_DBUS,
1408                                  proposed_recipient_loginfo);
1409      _dbus_verbose ("security policy disallowing message due to sender policy\n");
1410      return FALSE;
1411    }
1412
1413  if (log)
1414    bus_context_log_security (context,
1415                              "Would reject message, %d matched rules; "
1416                              "type=\"%s\", sender=\"%s\" (%s) interface=\"%s\" member=\"%s\" error name=\"%s\" requested_reply=%d destination=\"%s\" (%s))",
1417                              toggles,
1418                              dbus_message_type_to_string (dbus_message_get_type (message)),
1419                              sender_name ? sender_name : "(unset)",
1420                              sender_loginfo,
1421                              dbus_message_get_interface (message) ?
1422                              dbus_message_get_interface (message) : "(unset)",
1423                              dbus_message_get_member (message) ?
1424                              dbus_message_get_member (message) : "(unset)",
1425                              dbus_message_get_error_name (message) ?
1426                              dbus_message_get_error_name (message) : "(unset)",
1427                              requested_reply,
1428                              dest ? dest : DBUS_SERVICE_DBUS,
1429                              proposed_recipient_loginfo);
1430
1431  if (recipient_policy &&
1432      !bus_client_policy_check_can_receive (recipient_policy,
1433                                            context->registry,
1434                                            requested_reply,
1435                                            sender,
1436                                            addressed_recipient, proposed_recipient,
1437                                            message, &toggles))
1438    {
1439      const char *msg = "Rejected receive message, %d matched rules; "
1440                        "type=\"%s\" sender=\"%s\" (%s) interface=\"%s\" member=\"%s\" error name=\"%s\" reply serial=%u requested_reply=%d destination=\"%s\" (%s))";
1441
1442      dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED, msg,
1443                      toggles,
1444                      dbus_message_type_to_string (dbus_message_get_type (message)),
1445                      sender_name ? sender_name : "(unset)",
1446                      sender_loginfo,
1447                      dbus_message_get_interface (message) ?
1448                      dbus_message_get_interface (message) : "(unset)",
1449                      dbus_message_get_member (message) ?
1450                      dbus_message_get_member (message) : "(unset)",
1451                      dbus_message_get_error_name (message) ?
1452                      dbus_message_get_error_name (message) : "(unset)",
1453                      dbus_message_get_reply_serial (message),
1454                      requested_reply,
1455                      dest ? dest : DBUS_SERVICE_DBUS,
1456                      proposed_recipient_loginfo);
1457      /* Needs to be duplicated to avoid calling malloc and having to handle OOM */
1458      if (addressed_recipient == proposed_recipient)
1459        bus_context_log_security (context, msg,
1460                                  toggles,
1461                                  dbus_message_type_to_string (dbus_message_get_type (message)),
1462                                  sender_name ? sender_name : "(unset)",
1463                                  sender_loginfo,
1464                                  dbus_message_get_interface (message) ?
1465                                  dbus_message_get_interface (message) : "(unset)",
1466                                  dbus_message_get_member (message) ?
1467                                  dbus_message_get_member (message) : "(unset)",
1468                                  dbus_message_get_error_name (message) ?
1469                                  dbus_message_get_error_name (message) : "(unset)",
1470                                  dbus_message_get_reply_serial (message),
1471                                  requested_reply,
1472                                  dest ? dest : DBUS_SERVICE_DBUS,
1473                                  proposed_recipient_loginfo);
1474      _dbus_verbose ("security policy disallowing message due to recipient policy\n");
1475      return FALSE;
1476    }
1477
1478  /* See if limits on size have been exceeded */
1479  if (proposed_recipient &&
1480      ((dbus_connection_get_outgoing_size (proposed_recipient) > context->limits.max_outgoing_bytes) ||
1481       (dbus_connection_get_outgoing_unix_fds (proposed_recipient) > context->limits.max_outgoing_unix_fds)))
1482    {
1483      dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
1484                      "The destination service \"%s\" has a full message queue",
1485                      dest ? dest : (proposed_recipient ?
1486                                     bus_connection_get_name (proposed_recipient) :
1487                                     DBUS_SERVICE_DBUS));
1488      _dbus_verbose ("security policy disallowing message due to full message queue\n");
1489      return FALSE;
1490    }
1491
1492  /* Record that we will allow a reply here in the future (don't
1493   * bother if the recipient is the bus or this is an eavesdropping
1494   * connection). Only the addressed recipient may reply.
1495   */
1496  if (type == DBUS_MESSAGE_TYPE_METHOD_CALL &&
1497      sender &&
1498      addressed_recipient &&
1499      addressed_recipient == proposed_recipient && /* not eavesdropping */
1500      !bus_connections_expect_reply (bus_connection_get_connections (sender),
1501                                     transaction,
1502                                     sender, addressed_recipient,
1503                                     message, error))
1504    {
1505      _dbus_verbose ("Failed to record reply expectation or problem with the message expecting a reply\n");
1506      return FALSE;
1507    }
1508
1509  _dbus_verbose ("security policy allowing message\n");
1510  return TRUE;
1511}
1512