The CAN bus is an ISO standard bus for vehicles. It manages the Chassis Electrical System Control and is responsible for critical activities like engine electrical, and skid control. This system is also used to provide vehicle diagnostic information for maintenance. A multi-star configuration seems typical of this bus with a primary bus line that branches into sub bus lines at its extremities then attaches to multiple device nodes. Differential voltage is applied over twisted pair at 1.5 to 2.5V and 2.5 to 3.5V for noise resistant signaling. Communication occurs at 500 kbps with 1-8 Bytes of data inside of each transmitted packet.
(Jeremiah J. Flerchinger Source)
CAN Support in Linux
The Linux kernel supports CAN with the SocketCAN framework.