bus.c 36.4 KB
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/* -*- mode: C; c-file-style: "gnu" -*- */
/* bus.c  message bus context object
 *
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 * Copyright (C) 2003, 2004 Red Hat, Inc.
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 *
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 * Licensed under the Academic Free License version 2.1
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 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include "bus.h"
#include "activation.h"
#include "connection.h"
#include "services.h"
#include "utils.h"
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#include "policy.h"
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#include "config-parser.h"
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#include "signals.h"
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#include "selinux.h"
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#include <dbus/dbus-list.h>
#include <dbus/dbus-hash.h>
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#include <dbus/dbus-internals.h>

struct BusContext
{
  int refcount;
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  char *config_file;
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  char *type;
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  char *address;
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  char *pidfile;
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  char *user;
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  DBusLoop *loop;
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  DBusList *servers;
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  BusConnections *connections;
  BusActivation *activation;
  BusRegistry *registry;
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  BusPolicy *policy;
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  BusMatchmaker *matchmaker;
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  DBusUserDatabase *user_database;
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  BusLimits limits;
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  unsigned int fork : 1;
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};

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static dbus_int32_t server_data_slot = -1;
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typedef struct
{
  BusContext *context;
} BusServerData;

#define BUS_SERVER_DATA(server) (dbus_server_get_data ((server), server_data_slot))

static BusContext*
server_get_context (DBusServer *server)
{
  BusContext *context;
  BusServerData *bd;
  
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  if (!dbus_server_allocate_data_slot (&server_data_slot))
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    return NULL;

  bd = BUS_SERVER_DATA (server);
  if (bd == NULL)
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    {
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      dbus_server_free_data_slot (&server_data_slot);
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      return NULL;
    }
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  context = bd->context;

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  dbus_server_free_data_slot (&server_data_slot);
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  return context;
}

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static dbus_bool_t
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server_watch_callback (DBusWatch     *watch,
                       unsigned int   condition,
                       void          *data)
{
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  /* FIXME this can be done in dbus-mainloop.c
   * if the code in activation.c for the babysitter
   * watch handler is fixed.
   */
  
  return dbus_watch_handle (watch, condition);
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}

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static dbus_bool_t
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add_server_watch (DBusWatch  *watch,
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                  void       *data)
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{
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  DBusServer *server = data;
  BusContext *context;
  
  context = server_get_context (server);
  
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  return _dbus_loop_add_watch (context->loop,
                               watch, server_watch_callback, server,
                               NULL);
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}

static void
remove_server_watch (DBusWatch  *watch,
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                     void       *data)
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{
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  DBusServer *server = data;
  BusContext *context;
  
  context = server_get_context (server);
  
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  _dbus_loop_remove_watch (context->loop,
                           watch, server_watch_callback, server);
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}

129

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static void
server_timeout_callback (DBusTimeout   *timeout,
                         void          *data)
{
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  /* can return FALSE on OOM but we just let it fire again later */
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  dbus_timeout_handle (timeout);
}

static dbus_bool_t
add_server_timeout (DBusTimeout *timeout,
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                    void        *data)
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{
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  DBusServer *server = data;
  BusContext *context;
  
  context = server_get_context (server);

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  return _dbus_loop_add_timeout (context->loop,
                                 timeout, server_timeout_callback, server, NULL);
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}

static void
remove_server_timeout (DBusTimeout *timeout,
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                       void        *data)
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{
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  DBusServer *server = data;
  BusContext *context;
  
  context = server_get_context (server);
  
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  _dbus_loop_remove_timeout (context->loop,
                             timeout, server_timeout_callback, server);
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}

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static void
new_connection_callback (DBusServer     *server,
                         DBusConnection *new_connection,
                         void           *data)
{
  BusContext *context = data;
  
  if (!bus_connections_setup_connection (context->connections, new_connection))
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    {
      _dbus_verbose ("No memory to setup new connection\n");
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      /* if we don't do this, it will get unref'd without
       * being disconnected... kind of strange really
       * that we have to do this, people won't get it right
       * in general.
       */
      dbus_connection_disconnect (new_connection);
    }
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  dbus_connection_set_max_received_size (new_connection,
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                                         context->limits.max_incoming_bytes);
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  dbus_connection_set_max_message_size (new_connection,
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                                        context->limits.max_message_size);
188
  
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  /* on OOM, we won't have ref'd the connection so it will die. */
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}

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static void
free_server_data (void *data)
{
  BusServerData *bd = data;  
  
  dbus_free (bd);
}

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static dbus_bool_t
setup_server (BusContext *context,
              DBusServer *server,
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              char      **auth_mechanisms,
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              DBusError  *error)
205
{
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  BusServerData *bd;
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  bd = dbus_new0 (BusServerData, 1);
  if (!dbus_server_set_data (server,
                             server_data_slot,
                             bd, free_server_data))
    {
      dbus_free (bd);
      BUS_SET_OOM (error);
      return FALSE;
    }

  bd->context = context;
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  if (!dbus_server_set_auth_mechanisms (server, (const char**) auth_mechanisms))
    {
      BUS_SET_OOM (error);
      return FALSE;
    }
  
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  dbus_server_set_new_connection_function (server,
                                           new_connection_callback,
                                           context, NULL);
  
  if (!dbus_server_set_watch_functions (server,
                                        add_server_watch,
                                        remove_server_watch,
                                        NULL,
                                        server,
                                        NULL))
    {
      BUS_SET_OOM (error);
      return FALSE;
    }

  if (!dbus_server_set_timeout_functions (server,
                                          add_server_timeout,
                                          remove_server_timeout,
                                          NULL,
                                          server, NULL))
    {
      BUS_SET_OOM (error);
      return FALSE;
    }
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  return TRUE;
}

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/* This code only gets executed the first time the
   config files are parsed.  It is not executed
   when config files are reloaded.*/
static dbus_bool_t
process_config_first_time_only (BusContext      *context,
				BusConfigParser *parser,
				DBusError       *error)
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{
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  DBusList *link;
  DBusList **addresses;
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  const char *user, *pidfile;
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  char **auth_mechanisms;
  DBusList **auth_mechanisms_list;
  int len;
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  dbus_bool_t retval;
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  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
271

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  retval = FALSE;
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  auth_mechanisms = NULL;
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  /* Check for an existing pid file. Of course this is a race;
   * we'd have to use fcntl() locks on the pid file to
   * avoid that. But we want to check for the pid file
   * before overwriting any existing sockets, etc.
   */
  pidfile = bus_config_parser_get_pidfile (parser);
  if (pidfile != NULL)
    {
      DBusString u;
      DBusStat stbuf;
      
      _dbus_string_init_const (&u, pidfile);
      
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      if (_dbus_stat (&u, &stbuf, NULL))
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	{
	  dbus_set_error (error, DBUS_ERROR_FAILED,
			  "The pid file \"%s\" exists, if the message bus is not running, remove this file",
			  pidfile);
	  goto failed;
	}
    }
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  /* keep around the pid filename so we can delete it later */
  context->pidfile = _dbus_strdup (pidfile);
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  /* Build an array of auth mechanisms */
  
  auth_mechanisms_list = bus_config_parser_get_mechanisms (parser);
  len = _dbus_list_get_length (auth_mechanisms_list);

  if (len > 0)
    {
      int i;

      auth_mechanisms = dbus_new0 (char*, len + 1);
      if (auth_mechanisms == NULL)
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	{
	  BUS_SET_OOM (error);
	  goto failed;
	}
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      i = 0;
      link = _dbus_list_get_first_link (auth_mechanisms_list);
      while (link != NULL)
        {
          auth_mechanisms[i] = _dbus_strdup (link->data);
          if (auth_mechanisms[i] == NULL)
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	    {
	      BUS_SET_OOM (error);
	      goto failed;
	    }
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          link = _dbus_list_get_next_link (auth_mechanisms_list, link);
        }
    }
  else
    {
      auth_mechanisms = NULL;
    }

  /* Listen on our addresses */
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  addresses = bus_config_parser_get_addresses (parser);  
  
  link = _dbus_list_get_first_link (addresses);
  while (link != NULL)
    {
      DBusServer *server;
      
      server = dbus_server_listen (link->data, error);
      if (server == NULL)
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	{
	  _DBUS_ASSERT_ERROR_IS_SET (error);
	  goto failed;
	}
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      else if (!setup_server (context, server, auth_mechanisms, error))
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	{
	  _DBUS_ASSERT_ERROR_IS_SET (error);
	  goto failed;
	}
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      if (!_dbus_list_append (&context->servers, server))
        {
          BUS_SET_OOM (error);
          goto failed;
        }          
      
      link = _dbus_list_get_next_link (addresses, link);
    }

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  /* note that type may be NULL */
  context->type = _dbus_strdup (bus_config_parser_get_type (parser));
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  if (bus_config_parser_get_type (parser) != NULL && context->type == NULL)
    {
      BUS_SET_OOM (error);
      goto failed;
    }
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  user = bus_config_parser_get_user (parser);
  if (user != NULL)
    {
      context->user = _dbus_strdup (user);
      if (context->user == NULL)
	{
	  BUS_SET_OOM (error);
	  goto failed;
	}
    }

  context->fork = bus_config_parser_get_fork (parser);
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  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  retval = TRUE;

 failed:
  dbus_free_string_array (auth_mechanisms);
  return retval;
}

/* This code gets executed every time the config files
   are parsed: both during BusContext construction
   and on reloads. */
static dbus_bool_t
process_config_every_time (BusContext      *context,
			   BusConfigParser *parser,
			   dbus_bool_t      is_reload,
			   DBusError       *error)
{
  DBusString full_address;
  DBusList *link;
  
  dbus_bool_t retval;

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);

  retval = FALSE;

  if (!_dbus_string_init (&full_address))
    {
      BUS_SET_OOM (error);
      return FALSE;
    }

  /* get our limits and timeout lengths */
  bus_config_parser_get_limits (parser, &context->limits);

  context->policy = bus_config_parser_steal_policy (parser);
  _dbus_assert (context->policy != NULL);

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  /* We have to build the address backward, so that
   * <listen> later in the config file have priority
   */
  link = _dbus_list_get_last_link (&context->servers);
  while (link != NULL)
    {
      char *addr;
      
      addr = dbus_server_get_address (link->data);
      if (addr == NULL)
        {
          BUS_SET_OOM (error);
          goto failed;
        }

      if (_dbus_string_get_length (&full_address) > 0)
        {
          if (!_dbus_string_append (&full_address, ";"))
            {
              BUS_SET_OOM (error);
              goto failed;
            }
        }
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      if (!_dbus_string_append (&full_address, addr))
        {
          BUS_SET_OOM (error);
          goto failed;
        }

      dbus_free (addr);

      link = _dbus_list_get_prev_link (&context->servers, link);
    }

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  if (is_reload)
    dbus_free (context->address);

461
  if (!_dbus_string_copy_data (&full_address, &context->address))
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    {
      BUS_SET_OOM (error);
      goto failed;
    }
466

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  /* Create activation subsystem */
  
  if (is_reload)
    bus_activation_unref (context->activation);
  
  context->activation = bus_activation_new (context, &full_address,
                                            bus_config_parser_get_service_dirs (parser),
                                            error);
  if (context->activation == NULL)
    {
      _DBUS_ASSERT_ERROR_IS_SET (error);
      goto failed;
    }

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  retval = TRUE;

 failed:
  _dbus_string_free (&full_address);
  return retval;
}

static dbus_bool_t
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process_config_postinit (BusContext *context,
			 BusConfigParser *parser,
			 DBusError *error)
493
{
494
  DBusHashTable *service_context_table;
495

496 497 498
  service_context_table = bus_config_parser_steal_service_context_table (parser);
  if (!bus_registry_set_service_context_table (context->registry,
					       service_context_table))
499
    {
500 501
      BUS_SET_OOM (error);
      return FALSE;
502 503
    }

504 505
  _dbus_hash_table_unref (service_context_table);
  return TRUE;
506 507 508 509
}

BusContext*
bus_context_new (const DBusString *config_file,
510
                 ForceForkSetting  force_fork,
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                 int               print_addr_fd,
                 int               print_pid_fd,
                 DBusError        *error)
{
  BusContext *context;
516
  BusConfigParser *parser;
517 518 519
  
  _DBUS_ASSERT_ERROR_IS_CLEAR (error);

520 521 522
  context = NULL;
  parser = NULL;

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  if (!dbus_server_allocate_data_slot (&server_data_slot))
    {
      BUS_SET_OOM (error);
      return NULL;
    }

  context = dbus_new0 (BusContext, 1);
  if (context == NULL)
    {
      BUS_SET_OOM (error);
      goto failed;
    }
  context->refcount = 1;

  if (!_dbus_string_copy_data (config_file, &context->config_file))
    {
      BUS_SET_OOM (error);
      goto failed;
    }

  context->loop = _dbus_loop_new ();
  if (context->loop == NULL)
    {
      BUS_SET_OOM (error);
      goto failed;
    }

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  context->registry = bus_registry_new (context);
  if (context->registry == NULL)
    {
      BUS_SET_OOM (error);
      goto failed;
    }
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  parser = bus_config_load (config_file, TRUE, NULL, error);
  if (parser == NULL)
    {
      _DBUS_ASSERT_ERROR_IS_SET (error);
      goto failed;
    }
563
  
564 565 566 567 568 569
  if (!process_config_first_time_only (context, parser, error))
    {
      _DBUS_ASSERT_ERROR_IS_SET (error);
      goto failed;
    }
  if (!process_config_every_time (context, parser, FALSE, error))
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    {
      _DBUS_ASSERT_ERROR_IS_SET (error);
      goto failed;
    }
  
  /* we need another ref of the server data slot for the context
   * to own
   */
  if (!dbus_server_allocate_data_slot (&server_data_slot))
    _dbus_assert_not_reached ("second ref of server data slot failed");

  context->user_database = _dbus_user_database_new ();
  if (context->user_database == NULL)
    {
      BUS_SET_OOM (error);
      goto failed;
    }
  
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  /* Note that we don't know whether the print_addr_fd is
   * one of the sockets we're using to listen on, or some
   * other random thing. But I think the answer is "don't do
   * that then"
   */
  if (print_addr_fd >= 0)
    {
      DBusString addr;
      const char *a = bus_context_get_address (context);
      int bytes;
      
      _dbus_assert (a != NULL);
      if (!_dbus_string_init (&addr))
        {
          BUS_SET_OOM (error);
          goto failed;
        }
      
      if (!_dbus_string_append (&addr, a) ||
          !_dbus_string_append (&addr, "\n"))
        {
          _dbus_string_free (&addr);
          BUS_SET_OOM (error);
          goto failed;
        }

      bytes = _dbus_string_get_length (&addr);
      if (_dbus_write (print_addr_fd, &addr, 0, bytes) != bytes)
        {
          dbus_set_error (error, DBUS_ERROR_FAILED,
                          "Printing message bus address: %s\n",
                          _dbus_strerror (errno));
          _dbus_string_free (&addr);
          goto failed;
        }

      if (print_addr_fd > 2)
        _dbus_close (print_addr_fd, NULL);

      _dbus_string_free (&addr);
    }
  
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  context->connections = bus_connections_new (context);
  if (context->connections == NULL)
    {
      BUS_SET_OOM (error);
      goto failed;
    }

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  context->matchmaker = bus_matchmaker_new ();
  if (context->matchmaker == NULL)
    {
      BUS_SET_OOM (error);
      goto failed;
    }
  
644
  /* Now become a daemon if appropriate */
645
  if ((force_fork != FORK_NEVER && context->fork) || force_fork == FORK_ALWAYS)
646
    {
647 648
      DBusString u;

649 650
      if (context->pidfile)
        _dbus_string_init_const (&u, context->pidfile);
651
      
652 653 654
      if (!_dbus_become_daemon (context->pidfile ? &u : NULL, 
				print_pid_fd,
				error))
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	{
	  _DBUS_ASSERT_ERROR_IS_SET (error);
	  goto failed;
	}
659
    }
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  else
    {
      /* Need to write PID file for ourselves, not for the child process */
663
      if (context->pidfile != NULL)
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        {
          DBusString u;

667
          _dbus_string_init_const (&u, context->pidfile);
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          if (!_dbus_write_pid_file (&u, _dbus_getpid (), error))
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	    {
	      _DBUS_ASSERT_ERROR_IS_SET (error);
	      goto failed;
	    }
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        }
    }
676

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  /* Write PID if requested */
  if (print_pid_fd >= 0)
    {
      DBusString pid;
      int bytes;

      if (!_dbus_string_init (&pid))
        {
          BUS_SET_OOM (error);
          goto failed;
        }
      
      if (!_dbus_string_append_int (&pid, _dbus_getpid ()) ||
          !_dbus_string_append (&pid, "\n"))
        {
          _dbus_string_free (&pid);
          BUS_SET_OOM (error);
          goto failed;
        }

      bytes = _dbus_string_get_length (&pid);
      if (_dbus_write (print_pid_fd, &pid, 0, bytes) != bytes)
        {
          dbus_set_error (error, DBUS_ERROR_FAILED,
                          "Printing message bus PID: %s\n",
                          _dbus_strerror (errno));
          _dbus_string_free (&pid);
          goto failed;
        }

      if (print_pid_fd > 2)
        _dbus_close (print_pid_fd, NULL);
      
      _dbus_string_free (&pid);
    }
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  if (!bus_selinux_full_init ())
    {
      _dbus_warn ("SELinux initialization failed\n");
    }

  if (!process_config_postinit (context, parser, error))
    {
      _DBUS_ASSERT_ERROR_IS_SET (error);
      goto failed;
    }
  if (parser != NULL)
    bus_config_parser_unref (parser);
725
  
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  /* Here we change our credentials if required,
   * as soon as we've set up our sockets and pidfile
   */
729
  if (context->user != NULL)
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    {
      DBusCredentials creds;
      DBusString u;

734
      _dbus_string_init_const (&u, context->user);
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      if (!_dbus_credentials_from_username (&u, &creds) ||
          creds.uid < 0 ||
          creds.gid < 0)
        {
          dbus_set_error (error, DBUS_ERROR_FAILED,
                          "Could not get UID and GID for username \"%s\"",
742
                          context->user);
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          goto failed;
        }
      
      if (!_dbus_change_identity (creds.uid, creds.gid, error))
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	{
	  _DBUS_ASSERT_ERROR_IS_SET (error);
	  goto failed;
	}
751
    }
752
  
753
  dbus_server_free_data_slot (&server_data_slot);
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  return context;
  
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 failed:  
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  if (parser != NULL)
    bus_config_parser_unref (parser);
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  if (context != NULL)
    bus_context_unref (context);

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  if (server_data_slot >= 0)
    dbus_server_free_data_slot (&server_data_slot);
765
  
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  return NULL;
}

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dbus_bool_t
bus_context_reload_config (BusContext *context,
			   DBusError  *error)
{
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  BusConfigParser *parser;
  DBusString config_file;
  dbus_bool_t ret;

  ret = FALSE;
  _dbus_string_init_const (&config_file, context->config_file);
  parser = bus_config_load (&config_file, TRUE, NULL, error);
  if (parser == NULL)
    {
      _DBUS_ASSERT_ERROR_IS_SET (error);
      goto failed;
    }
  
  if (!process_config_every_time (context, parser, TRUE, error))
    {
      _DBUS_ASSERT_ERROR_IS_SET (error);
      goto failed;
    }
  if (!process_config_postinit (context, parser, error))
    {
      _DBUS_ASSERT_ERROR_IS_SET (error);
      goto failed;
    }
  ret = TRUE;

 failed:  
  if (parser != NULL)
    bus_config_parser_unref (parser);
  return ret;
802 803
}

804 805 806
static void
shutdown_server (BusContext *context,
                 DBusServer *server)
807
{
808 809
  if (server == NULL ||
      !dbus_server_get_is_connected (server))
810 811
    return;
  
812
  if (!dbus_server_set_watch_functions (server,
813
                                        NULL, NULL, NULL,
814 815 816 817
                                        context,
                                        NULL))
    _dbus_assert_not_reached ("setting watch functions to NULL failed");
  
818
  if (!dbus_server_set_timeout_functions (server,
819
                                          NULL, NULL, NULL,
820 821 822 823
                                          context,
                                          NULL))
    _dbus_assert_not_reached ("setting timeout functions to NULL failed");
  
824 825 826 827 828 829 830 831 832 833 834 835 836 837 838
  dbus_server_disconnect (server);
}

void
bus_context_shutdown (BusContext  *context)
{
  DBusList *link;

  link = _dbus_list_get_first_link (&context->servers);
  while (link != NULL)
    {
      shutdown_server (context, link->data);

      link = _dbus_list_get_next_link (&context->servers, link);
    }
839 840
}

841
BusContext *
842 843 844 845
bus_context_ref (BusContext *context)
{
  _dbus_assert (context->refcount > 0);
  context->refcount += 1;
846 847

  return context;
848 849 850 851 852 853 854 855 856 857
}

void
bus_context_unref (BusContext *context)
{
  _dbus_assert (context->refcount > 0);
  context->refcount -= 1;

  if (context->refcount == 0)
    {
858 859
      DBusList *link;
      
860 861
      _dbus_verbose ("Finalizing bus context %p\n", context);
      
862
      bus_context_shutdown (context);
863 864 865 866 867 868

      if (context->connections)
        {
          bus_connections_unref (context->connections);
          context->connections = NULL;
        }
869
      
870
      if (context->registry)
871 872 873 874 875
        {
          bus_registry_unref (context->registry);
          context->registry = NULL;
        }
      
876
      if (context->activation)
877 878 879 880
        {
          bus_activation_unref (context->activation);
          context->activation = NULL;
        }
881 882 883

      link = _dbus_list_get_first_link (&context->servers);
      while (link != NULL)
884
        {
885 886 887
          dbus_server_unref (link->data);
          
          link = _dbus_list_get_next_link (&context->servers, link);
888
        }
889
      _dbus_list_clear (&context->servers);
890

891
      if (context->policy)
892
        {
893 894
          bus_policy_unref (context->policy);
          context->policy = NULL;
895
        }
896
      
897 898
      if (context->loop)
        {
899
          _dbus_loop_unref (context->loop);
900 901
          context->loop = NULL;
        }
902 903 904 905 906 907

      if (context->matchmaker)
        {
          bus_matchmaker_unref (context->matchmaker);
          context->matchmaker = NULL;
        }
908
      
909
      dbus_free (context->config_file);
910
      dbus_free (context->type);
911
      dbus_free (context->address);
912
      dbus_free (context->user);
913 914 915 916 917 918 919 920 921 922 923 924 925 926

      if (context->pidfile)
	{
          DBusString u;
          _dbus_string_init_const (&u, context->pidfile);

          /* Deliberately ignore errors here, since there's not much
	   * we can do about it, and we're exiting anyways.
	   */
	  _dbus_delete_file (&u, NULL);

          dbus_free (context->pidfile); 
	}

927 928
      if (context->user_database != NULL)
	_dbus_user_database_unref (context->user_database);
929
      
930
      dbus_free (context);
931

932
      dbus_server_free_data_slot (&server_data_slot);
933 934 935
    }
}

936 937 938 939 940 941 942
/* type may be NULL */
const char*
bus_context_get_type (BusContext *context)
{
  return context->type;
}

943 944 945 946 947 948
const char*
bus_context_get_address (BusContext *context)
{
  return context->address;
}

949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965
BusRegistry*
bus_context_get_registry (BusContext  *context)
{
  return context->registry;
}

BusConnections*
bus_context_get_connections (BusContext  *context)
{
  return context->connections;
}

BusActivation*
bus_context_get_activation (BusContext  *context)
{
  return context->activation;
}
966

967 968 969 970 971 972
BusMatchmaker*
bus_context_get_matchmaker (BusContext  *context)
{
  return context->matchmaker;
}

973
DBusLoop*
974 975 976 977 978
bus_context_get_loop (BusContext *context)
{
  return context->loop;
}

979 980 981 982 983 984
DBusUserDatabase*
bus_context_get_user_database (BusContext *context)
{
  return context->user_database;
}

985 986 987 988
dbus_bool_t
bus_context_allow_user (BusContext   *context,
                        unsigned long uid)
{
989 990 991
  return bus_policy_allow_user (context->policy,
                                context->user_database,
                                uid);
992 993
}

994 995 996 997 998 999
BusPolicy *
bus_context_get_policy (BusContext *context)
{
  return context->policy;
}

1000 1001
BusClientPolicy*
bus_context_create_client_policy (BusContext      *context,
1002 1003
                                  DBusConnection  *connection,
                                  DBusError       *error)
1004
{
1005 1006 1007
  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  return bus_policy_create_client_policy (context->policy, connection,
                                          error);
1008
}
1009 1010 1011 1012 1013

int
bus_context_get_activation_timeout (BusContext *context)
{
  
1014
  return context->limits.activation_timeout;
1015
}
1016

1017 1018 1019
int
bus_context_get_auth_timeout (BusContext *context)
{
1020
  return context->limits.auth_timeout;
1021 1022 1023 1024 1025
}

int
bus_context_get_max_completed_connections (BusContext *context)
{
1026
  return context->limits.max_completed_connections;
1027 1028 1029 1030 1031
}

int
bus_context_get_max_incomplete_connections (BusContext *context)
{
1032
  return context->limits.max_incomplete_connections;
1033 1034 1035 1036 1037
}

int
bus_context_get_max_connections_per_user (BusContext *context)
{
1038
  return context->limits.max_connections_per_user;
1039 1040
}

1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052
int
bus_context_get_max_pending_activations (BusContext *context)
{
  return context->limits.max_pending_activations;
}

int
bus_context_get_max_services_per_connection (BusContext *context)
{
  return context->limits.max_services_per_connection;
}

1053 1054 1055 1056 1057 1058
int
bus_context_get_max_match_rules_per_connection (BusContext *context)
{
  return context->limits.max_match_rules_per_connection;
}

1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070
int
bus_context_get_max_replies_per_connection (BusContext *context)
{
  return context->limits.max_replies_per_connection;
}

int
bus_context_get_reply_timeout (BusContext *context)
{
  return context->limits.reply_timeout;
}

1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083
/*
 * addressed_recipient is the recipient specified in the message.
 *
 * proposed_recipient is the recipient we're considering sending
 * to right this second, and may be an eavesdropper.
 *
 * sender is the sender of the message.
 *
 * NULL for proposed_recipient or sender definitely means the bus driver.
 *
 * NULL for addressed_recipient may mean the bus driver, or may mean
 * no destination was specified in the message (e.g. a signal).
 */
1084 1085
dbus_bool_t
bus_context_check_security_policy (BusContext     *context,
1086
                                   BusTransaction *transaction,
1087
                                   DBusConnection *sender,
1088 1089
                                   DBusConnection *addressed_recipient,
                                   DBusConnection *proposed_recipient,
1090 1091 1092 1093 1094
                                   DBusMessage    *message,
                                   DBusError      *error)
{
  BusClientPolicy *sender_policy;
  BusClientPolicy *recipient_policy;
1095
  int type;
1096
  dbus_bool_t requested_reply;
1097 1098 1099 1100 1101
  
  type = dbus_message_get_type (message);
  
  /* dispatch.c was supposed to ensure these invariants */
  _dbus_assert (dbus_message_get_destination (message) != NULL ||
1102 1103
                type == DBUS_MESSAGE_TYPE_SIGNAL ||
                (sender == NULL && !bus_connection_is_active (proposed_recipient)));
1104 1105 1106
  _dbus_assert (type == DBUS_MESSAGE_TYPE_SIGNAL ||
                addressed_recipient != NULL ||
                strcmp (dbus_message_get_destination (message), DBUS_SERVICE_ORG_FREEDESKTOP_DBUS) == 0);
1107
  
1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127
  switch (type)
    {
    case DBUS_MESSAGE_TYPE_METHOD_CALL:
    case DBUS_MESSAGE_TYPE_SIGNAL:
    case DBUS_MESSAGE_TYPE_METHOD_RETURN:
    case DBUS_MESSAGE_TYPE_ERROR:
      break;
      
    default:
      _dbus_verbose ("security check disallowing message of unknown type %d\n",
                     type);

      dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
                      "Message bus will not accept messages of unknown type\n");
              
      return FALSE;
    }

  requested_reply = FALSE;
  
1128 1129
  if (sender != NULL)
    {
1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151
      /* First verify the SELinux access controls.  If allowed then
       * go on with the standard checks.
       */
      if (!bus_selinux_allows_send (sender, proposed_recipient))
        {
          const char *dest = dbus_message_get_destination (message);
          dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
                          "An SELinux policy prevents this sender "
                          "from sending this message to this recipient "
                          "(rejected message had interface \"%s\" "
                          "member \"%s\" error name \"%s\" destination \"%s\")",
                          dbus_message_get_interface (message) ?
                          dbus_message_get_interface (message) : "(unset)",
                          dbus_message_get_member (message) ?
                          dbus_message_get_member (message) : "(unset)",
                          dbus_message_get_error_name (message) ?
                          dbus_message_get_error_name (message) : "(unset)",
                          dest ? dest : DBUS_SERVICE_ORG_FREEDESKTOP_DBUS);
          _dbus_verbose ("SELinux security check denying send to service\n");
          return FALSE;
        }
       
1152
      if (bus_connection_is_active (sender))
1153
        {
1154 1155
          sender_policy = bus_connection_get_policy (sender);
          _dbus_assert (sender_policy != NULL);
1156 1157 1158 1159 1160
          
          /* Fill in requested_reply variable with TRUE if this is a
           * reply and the reply was pending.
           */
          if (dbus_message_get_reply_serial (message) != 0)
1161 1162
            {
              if (proposed_recipient != NULL /* not to the bus driver */ &&
1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177
                  addressed_recipient == proposed_recipient /* not eavesdropping */)
                {
                  DBusError error2;                  
                  
                  dbus_error_init (&error2);
                  requested_reply = bus_connections_check_reply (bus_connection_get_connections (sender),
                                                                 transaction,
                                                                 sender, addressed_recipient, message,
                                                                 &error2);
                  if (dbus_error_is_set (&error2))
                    {
                      dbus_move_error (&error2, error);
                      return FALSE;
                    }
                }
1178
            }
1179 1180 1181 1182 1183 1184
        }
      else
        {
          /* Policy for inactive connections is that they can only send
           * the hello message to the bus driver
           */
1185
          if (proposed_recipient == NULL &&
1186 1187 1188
              dbus_message_is_method_call (message,
                                           DBUS_INTERFACE_ORG_FREEDESKTOP_DBUS,
                                           "Hello"))
1189 1190
            {
              _dbus_verbose ("security check allowing %s message\n",
1191
                             "Hello");
1192 1193 1194 1195 1196
              return TRUE;
            }
          else
            {
              _dbus_verbose ("security check disallowing non-%s message\n",
1197
                             "Hello");
1198 1199 1200

              dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
                              "Client tried to send a message other than %s without being registered",
1201
                              "Hello");
1202 1203 1204
              
              return FALSE;
            }
1205
        }
1206 1207
    }
  else
1208 1209 1210 1211 1212 1213 1214 1215 1216 1217
    {
      sender_policy = NULL;

      /* If the sender is the bus driver, we assume any reply was a
       * requested reply as bus driver won't send bogus ones
       */
      if (addressed_recipient == proposed_recipient /* not eavesdropping */ &&
          dbus_message_get_reply_serial (message) != 0)
        requested_reply = TRUE;
    }
1218

1219 1220 1221
  _dbus_assert ((sender != NULL && sender_policy != NULL) ||
                (sender == NULL && sender_policy == NULL));
  
1222
  if (proposed_recipient != NULL)
1223
    {
1224 1225 1226 1227
      /* only the bus driver can send to an inactive recipient (as it
       * owns no services, so other apps can't address it). Inactive
       * recipients can receive any message.
       */
1228
      if (bus_connection_is_active (proposed_recipient))
1229
        {
1230
          recipient_policy = bus_connection_get_policy (proposed_recipient);
1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241
          _dbus_assert (recipient_policy != NULL);
        }
      else if (sender == NULL)
        {
          _dbus_verbose ("security check using NULL recipient policy for message from bus\n");
          recipient_policy = NULL;
        }
      else
        {
          _dbus_assert_not_reached ("a message was somehow sent to an inactive recipient from a source other than the message bus\n");
          recipient_policy = NULL;
1242
        }
1243 1244 1245
    }
  else
    recipient_policy = NULL;
1246
  
1247 1248 1249
  _dbus_assert ((proposed_recipient != NULL && recipient_policy != NULL) ||
                (proposed_recipient != NULL && sender == NULL && recipient_policy == NULL) ||
                (proposed_recipient == NULL && recipient_policy == NULL));
1250 1251
  
  if (sender_policy &&
1252
      !bus_client_policy_check_can_send (sender_policy,
1253 1254 1255
                                         context->registry,
                                         requested_reply,
                                         proposed_recipient,
1256 1257
                                         message))
    {
1258
      const char *dest = dbus_message_get_destination (message);
1259 1260 1261 1262
      dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
                      "A security policy in place prevents this sender "
                      "from sending this message to this recipient, "
                      "see message bus configuration file (rejected message "
1263 1264 1265 1266 1267 1268 1269 1270
                      "had interface \"%s\" member \"%s\" error name \"%s\" destination \"%s\")",
                      dbus_message_get_interface (message) ?
                      dbus_message_get_interface (message) : "(unset)",
                      dbus_message_get_member (message) ?
                      dbus_message_get_member (message) : "(unset)",
                      dbus_message_get_error_name (message) ?
                      dbus_message_get_error_name (message) : "(unset)",
                      dest ? dest : DBUS_SERVICE_ORG_FREEDESKTOP_DBUS);
1271
      _dbus_verbose ("security policy disallowing message due to sender policy\n");
1272 1273 1274
      return FALSE;
    }

1275
  if (recipient_policy &&
1276
      !bus_client_policy_check_can_receive (recipient_policy,
1277 1278 1279
                                            context->registry,
                                            requested_reply,
                                            sender,
1280
                                            addressed_recipient, proposed_recipient,
1281 1282
                                            message))
    {
1283
      const char *dest = dbus_message_get_destination (message);
1284 1285 1286 1287
      dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
                      "A security policy in place prevents this recipient "
                      "from receiving this message from this sender, "
                      "see message bus configuration file (rejected message "
1288
                      "had interface \"%s\" member \"%s\" error name \"%s\" destination \"%s\" reply serial %u requested_reply=%d)",
1289 1290 1291 1292 1293 1294
                      dbus_message_get_interface (message) ?
                      dbus_message_get_interface (message) : "(unset)",
                      dbus_message_get_member (message) ?
                      dbus_message_get_member (message) : "(unset)",
                      dbus_message_get_error_name (message) ?
                      dbus_message_get_error_name (message) : "(unset)",
1295 1296 1297
                      dest ? dest : DBUS_SERVICE_ORG_FREEDESKTOP_DBUS,
                      dbus_message_get_reply_serial (message),
                      requested_reply);
1298
      _dbus_verbose ("security policy disallowing message due to recipient policy\n");
1299 1300 1301
      return FALSE;
    }

1302
  /* See if limits on size have been exceeded */
1303 1304
  if (proposed_recipient &&
      dbus_connection_get_outgoing_size (proposed_recipient) >
1305
      context->limits.max_outgoing_bytes)
1306
    {
1307
      const char *dest = dbus_message_get_destination (message);
1308 1309
      dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
                      "The destination service \"%s\" has a full message queue",
1310 1311 1312
                      dest ? dest : (proposed_recipient ?
                                     bus_connection_get_name (proposed_recipient) : 
                                     DBUS_SERVICE_ORG_FREEDESKTOP_DBUS));
1313
      _dbus_verbose ("security policy disallowing message due to full message queue\n");
1314 1315
      return FALSE;
    }
1316

1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333
  if (type == DBUS_MESSAGE_TYPE_METHOD_CALL)
    {
      /* Record that we will allow a reply here in the future (don't
       * bother if the recipient is the bus). Only the addressed recipient
       * may reply.
       */
      if (sender && addressed_recipient &&
          !bus_connections_expect_reply (bus_connection_get_connections (sender),
                                         transaction,
                                         sender, addressed_recipient,
                                         message, error))
        {
          _dbus_verbose ("Failed to record reply expectation or problem with the message expecting a reply\n");
          return FALSE;
        }
    }
  
1334
  _dbus_verbose ("security policy allowing message\n");
1335 1336
  return TRUE;
}