BlueZ

BlueZ serves as the primary Bluetooth protocol stack for Linux systems, offering comprehensive tools for managing Bluetooth hardware and communicating with Bluetooth devices. The package includes essential daemons like bluetoothd for core Bluetooth services and numerous command-line utilities for tasks such as device discovery, pairing, connection management, and protocol testing.

Key use cases include Bluetooth device enumeration, security testing, firmware management, and protocol analysis. Tools like bluetoothctl provide interactive control for modern Bluetooth operations including LE advertising and GATT services, while legacy tools like hcitool and hciconfig handle classic Bluetooth configurations. Testing utilities enable thorough validation of Bluetooth implementations across L2CAP, RFCOMM, and other protocols.

The stack supports both classic BR/EDR and Low Energy (BLE) Bluetooth, with specialized packages for mesh networking, OBEX file transfer, CUPS printing, and HCI packet analysis. BlueZ powers Bluetooth functionality in Kali Linux for wireless penetration testing and device forensics.

BlueZ implements the full Bluetooth protocol stack including HCI (Host Controller Interface), L2CAP, RFCOMM, SDP, and GATT/ATT for BLE. Core daemons like bluetoothd handle D-Bus interfaces for device management and plugin loading. Tools interact via HCI commands to controllers, enabling scanning, pairing (SSP/SC), connection establishment, and data exchange. Monitoring tools like btmon capture HCI traffic in btsnoop format for analysis. Testing utilities simulate client/server roles across protocols to validate kernel implementations and device compliance.