Пример #1
0
dbus_bool_t
bus_registry_acquire_service (BusRegistry      *registry,
                              DBusConnection   *connection,
                              const DBusString *service_name,
                              dbus_uint32_t     flags,
                              dbus_uint32_t    *result,
                              BusTransaction   *transaction,
                              DBusError        *error)
{
  dbus_bool_t retval;
  DBusConnection *old_owner_conn;
  BusClientPolicy *policy;
  BusService *service;
  BusActivation  *activation;
  BusSELinuxID *sid;
  BusOwner *primary_owner;
 
  retval = FALSE;

  if (!_dbus_validate_bus_name (service_name, 0,
                                _dbus_string_get_length (service_name)))
    {
      dbus_set_error (error, DBUS_ERROR_INVALID_ARGS,
                      "Requested bus name \"%s\" is not valid",
                      _dbus_string_get_const_data (service_name));
      
      _dbus_verbose ("Attempt to acquire invalid service name\n");
      
      goto out;
    }
  
  if (_dbus_string_get_byte (service_name, 0) == ':')
    {
      /* Not allowed; only base services can start with ':' */
      dbus_set_error (error, DBUS_ERROR_INVALID_ARGS,
                      "Cannot acquire a service starting with ':' such as \"%s\"",
                      _dbus_string_get_const_data (service_name));
      
      _dbus_verbose ("Attempt to acquire invalid base service name \"%s\"",
                     _dbus_string_get_const_data (service_name));
      
      goto out;
    }

  if (_dbus_string_equal_c_str (service_name, DBUS_SERVICE_DBUS))
    {
      dbus_set_error (error, DBUS_ERROR_INVALID_ARGS,
                      "Connection \"%s\" is not allowed to own the service \"%s\"because "
                      "it is reserved for D-Bus' use only",
                      bus_connection_is_active (connection) ?
                      bus_connection_get_name (connection) :
                      "(inactive)",
                      DBUS_SERVICE_DBUS);
      goto out;
    }

  policy = bus_connection_get_policy (connection);
  _dbus_assert (policy != NULL);

  /* Note that if sid is #NULL then the bus's own context gets used
   * in bus_connection_selinux_allows_acquire_service()
   */
  sid = bus_selinux_id_table_lookup (registry->service_sid_table,
                                     service_name);

  if (!bus_selinux_allows_acquire_service (connection, sid,
					   _dbus_string_get_const_data (service_name), error))
    {

      if (dbus_error_is_set (error) &&
	  dbus_error_has_name (error, DBUS_ERROR_NO_MEMORY))
	{
	  goto out;
	}

      dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
                      "Connection \"%s\" is not allowed to own the service \"%s\" due "
                      "to SELinux policy",
                      bus_connection_is_active (connection) ?
                      bus_connection_get_name (connection) :
                      "(inactive)",
                      _dbus_string_get_const_data (service_name));
      goto out;
    }
  
  if (!bus_client_policy_check_can_own (policy, service_name))
    {
      dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
                      "Connection \"%s\" is not allowed to own the service \"%s\" due "
                      "to security policies in the configuration file",
                      bus_connection_is_active (connection) ?
                      bus_connection_get_name (connection) :
                      "(inactive)",
                      _dbus_string_get_const_data (service_name));
      goto out;
    }

  if (bus_connection_get_n_services_owned (connection) >=
      bus_context_get_max_services_per_connection (registry->context))
    {
      dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
                      "Connection \"%s\" is not allowed to own more services "
                      "(increase limits in configuration file if required)",
                      bus_connection_is_active (connection) ?
                      bus_connection_get_name (connection) :
                      "(inactive)");
      goto out;
    }
  
  service = bus_registry_lookup (registry, service_name);

  if (service != NULL)
    {
      primary_owner = bus_service_get_primary_owner (service);
      if (primary_owner != NULL)
        old_owner_conn = primary_owner->conn;
      else
        old_owner_conn = NULL;
    }
  else
    old_owner_conn = NULL;
      
  if (service == NULL)
    {
      service = bus_registry_ensure (registry,
                                     service_name, connection, flags,
                                     transaction, error);
      if (service == NULL)
        goto out;
    }

  primary_owner = bus_service_get_primary_owner (service);
  if (primary_owner == NULL)
    goto out;

  if (old_owner_conn == NULL)
    {
      _dbus_assert (primary_owner->conn == connection);

      *result = DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER;      
    }
  else if (old_owner_conn == connection)
    {
      bus_owner_set_flags (primary_owner, flags);
      *result = DBUS_REQUEST_NAME_REPLY_ALREADY_OWNER;
    }
  else if (((flags & DBUS_NAME_FLAG_DO_NOT_QUEUE) &&
           !(bus_service_get_allow_replacement (service))) ||
	   ((flags & DBUS_NAME_FLAG_DO_NOT_QUEUE) &&
           !(flags & DBUS_NAME_FLAG_REPLACE_EXISTING))) 
    {
      DBusList *link;
      BusOwner *temp_owner;
    /* Since we can't be queued if we are already in the queue
       remove us */

      link = _bus_service_find_owner_link (service, connection);
      if (link != NULL)
        {
          _dbus_list_unlink (&service->owners, link);
          temp_owner = (BusOwner *)link->data;
          bus_owner_unref (temp_owner); 
          _dbus_list_free_link (link);
        }
      
      *result = DBUS_REQUEST_NAME_REPLY_EXISTS;
    }
  else if (!(flags & DBUS_NAME_FLAG_DO_NOT_QUEUE) &&
           (!(flags & DBUS_NAME_FLAG_REPLACE_EXISTING) ||
	    !(bus_service_get_allow_replacement (service))))
    {
      /* Queue the connection */
      if (!bus_service_add_owner (service, connection, 
                                  flags,
                                  transaction, error))
        goto out;
      
      *result = DBUS_REQUEST_NAME_REPLY_IN_QUEUE;
    }
  else
    {
      /* Replace the current owner */

      /* We enqueue the new owner and remove the first one because
       * that will cause NameAcquired and NameLost messages to
       * be sent.
       */
      
      if (!bus_service_add_owner (service, connection,
                                  flags,
                                  transaction, error))
        goto out;

      if (primary_owner->do_not_queue)
        {
          if (!bus_service_remove_owner (service, old_owner_conn,
                                         transaction, error))
            goto out;
        }
      else
        {
          if (!bus_service_swap_owner (service, old_owner_conn,
                                       transaction, error))
            goto out;
        }
        
    
      _dbus_assert (connection == bus_service_get_primary_owner (service)->conn);
      *result = DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER;
    }

  activation = bus_context_get_activation (registry->context);
  retval = bus_activation_send_pending_auto_activation_messages (activation,
								 service,
								 transaction);
  if (!retval)
    BUS_SET_OOM (error);
  
 out:
  return retval;
}
static dbus_bool_t
bus_driver_handle_hello (DBusConnection *connection,
                         BusTransaction *transaction,
                         DBusMessage    *message,
                         DBusError      *error)
{
  DBusString unique_name;
  BusService *service;
  dbus_bool_t retval;
  BusRegistry *registry;
  BusConnections *connections;

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);

  if (bus_connection_is_active (connection))
    {
      /* We already handled an Hello message for this connection. */
      dbus_set_error (error, DBUS_ERROR_FAILED,
                      "Already handled an Hello message");
      return FALSE;
    }

  /* Note that when these limits are exceeded we don't disconnect the
   * connection; we just sort of leave it hanging there until it times
   * out or disconnects itself or is dropped due to the max number of
   * incomplete connections. It's even OK if the connection wants to
   * retry the hello message, we support that.
   */
  connections = bus_connection_get_connections (connection);
  if (!bus_connections_check_limits (connections, connection,
                                     error))
    {
      _DBUS_ASSERT_ERROR_IS_SET (error);
      return FALSE;
    }
  
  if (!_dbus_string_init (&unique_name))
    {
      BUS_SET_OOM (error);
      return FALSE;
    }

  retval = FALSE;

  registry = bus_connection_get_registry (connection);
  
  if (!create_unique_client_name (registry, &unique_name))
    {
      BUS_SET_OOM (error);
      goto out_0;
    }

  if (!bus_connection_complete (connection, &unique_name, error))
    {
      _DBUS_ASSERT_ERROR_IS_SET (error);
      goto out_0;
    }
  
  if (!dbus_message_set_sender (message,
                                bus_connection_get_name (connection)))
    {
      BUS_SET_OOM (error);
      goto out_0;
    }
  
  if (!bus_driver_send_welcome_message (connection, message, transaction, error))
    goto out_0;

  /* Create the service */
  service = bus_registry_ensure (registry,
                                 &unique_name, connection, 0, transaction, error);
  if (service == NULL)
    goto out_0;
  
  _dbus_assert (bus_connection_is_active (connection));
  retval = TRUE;
  
 out_0:
  _dbus_string_free (&unique_name);
  return retval;
}