Hacking into a Vehicle CAN bus (Toyothack and SocketCAN)

CAN bus is an automation fieldbus commonly used in the automotive industry as the main network bus to allow communications between the many on-board ECUs on modern vehicles.

The Linux kernel has native CAN bus support at network layer since some years, with a lot of drivers for both embedded and USB CAN bus controllers, so it’s now fairly easy to add a CAN bus interface to any Linux laptop and have a playaround with it.

In this post I’ll show how to tap into a modern car local bus, dump a bunch of data and analyze the trace offline to write a decoder from scratch using the SocketCAN APIs and utilities.

This is based on my experiences hacking into my Toyota… Toyothack!


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Power Manager: Soft Power Control of USB and Low Voltage Devices

One frustrating aspect of firmware or kernel development on commodity hardware, such as cheap evaluation board or production devices, is the necessity of power-cycling the target device to reboot it every time the developer needs to load and run a new software build.

It sometimes happens that a development board is designed with proper management electronics to ease software development or automated testing, but in most cases the developer has reset the board manually, and sadly quite often reset buttons are unaccessible or just non-existent, requiring the developer to unplug and replug the power cable. If this ends up in your workflow and at the end of the day your fingers hurt, something is wrong.

This project is a small AVR/V-USB based board to control the power supply of development boards and other low voltage and USB powered devices. It allows to program a sequence of events for the output ports, has LED indicators for port status, and additionally provides power measurement on both USB and main power channels, and uses a bootloader for easy firmware upgrade… All in a solid and funny looking Hammond blue box!



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HP Wi-Fi Direct Mouse on Linux

In my last post I took apart an HP Wi-Fi Direct mouse based on the OZMO2000 controller from Ozmo Devices.

OZMO based devices are officially supported on Windows 7 platform only, rendering them completely useless as nobody uses Windows anymore… right? Well, it turns out most of the code to use them in Linux is already in place, just waiting to be enabled!


Wi-Fi direct support in Linux is quite young and still considered as experimental, so read on if you dare to try!

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Making Time Lapse Video with IP Cameras

What happens when you find yourself with two IP cameras which you don’t really use? You just make some funny stuff with them!

This post shows how to use an Axis IP camera and a netbook to record a timelapse video of a car travel… including a 15 minute timelapse of car trip from Italy to Germany!

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Linux Kernel Device Drivers for AVR V-USB Devices

V-USB is a really convenient library to implement USB communication between an AVR microcontroller and any USB host enabled system.

The host side software for a V-USB device is usually handled either from a class driver, such as for HID-compliant devices, or from an userspace libusb-based application.

This post shows how to implement a Linux kernel device driver for a simple ep0-based V-USB device.

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Network Statistics with iptables and rrdtool

Netfilter is a powerful tool when it comes to select traffic on a Linux router.

When you set up a chain of rules with iptables, you are also get set of traffic counters with each rule you set, which can be used to see how many times the rule have matched.

If you place a chain of rules without any jump, the packet get counted and goes forward the chain, so that you can write a set of rules just to get some statistic of selected pattern of traffic in your network.

In this post I’ll show how to write some simple rule, get the data on a rrdtool database and plot a traffic graphic out of it.

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Network Activity LED with Linux LED Subsystem

This is a nice userspace application I use on my router to control the Internet connection status LED in “smart” way.

The idea is simple, instead of just randomly blink the LED when there is some activity on the network, this application checks for the total bytes transferred on the network interface, and blinks the LED every 100KB of data.

That behavior is borrowed from modern electric counter, which have a LED that blinks every predefined number of Watt/hour.

That’s useful because you can quickly have an idea of the bandwidth utilization of your connection by just checking how often the LED blinks, so you can instantly identify a low-bandwidth constant traffic by a high-bandwidth traffic.

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