Bluez D-Bus Architecture

Description

The BlueZ D-Bus interfaces aim to provide seamless Bluetooth technology integration into the desktop. A central Bluetooth daemon "hcid"(planned to be renamed to bluetoothd) is responsible for take care of all tasks that can’t or shouldn’t be handled inside the Linux kernel. These jobs include PIN code and link key management for the authentication and encryption, caching of device names and services and also central control of the Bluetooth hardware. The interface exported allows to abstract the internals of GNOME, KDE, Maemo, OpenMoko, ... applications from any technical details of the Bluetooth specification. Even other application will get access to the Bluetooth technology without any hassle.

The BlueZ D-Bus services are exported through the system message bus. Every D-Bus enabled desktop has a system message bus instance running. This bus is used to broadcast system events, such as new hardware devices, network connection status, and so forth. The session message bus is not suitable for this architecture since the Bluetooth hardware/connections are shared by all desktop sessions.

The BlueZ D-Bus Architecture goal are:

• Abstract Bluetooth HCI commands/events
• Provide an easy interface to setup Bluetooth adapter and manage the services

Architecture ¶

The hcid is the main entity of the architecture. It implements methods to setup the Bluetooth adapters, retrieve remote device properties, control the pairing procedure and control the services registration/searches. The following figure shows a high level relationship between the entities.