FARTS, a recursive acronym for FARTS is A Real-Time Sniffer, is a Ethernet sniffer dedicated for real time (RT) applications like EtherCAT. It can simply be plugged in between two (RT) Ethernet devices to monitor all traffic transferred in between them, while introducing a very constant delay of only 1μs.

On EtherCAT, it was successfully tested with a cycle time of 100μs.

The used hardware is comprised by a Digilent/Avnet ZedBoard, which was extended by a Avnet AES-FMC-NETW1-G Network Expansion board.

All software and gateware sources are publicly available and can be used by anyone under the GPLv3 license. Please also note the licenses of the subprojects.

• Relative timestamping with 8ns accuracy
• low and constant byte forwarding delay of 1μs
• packet stream saved as PCAP file
• Podman/Docker based build system

• PC running a Linux based OS (other OSes are untested)
• Podman or Docker
• Vivado 2022.1 (newer versions may work, but are untested)
• Digilent/Avnet ZedBoard
• Avnet AES-FMC-NETW1-G Network Expansion board

├── docker : Code to setup a docker container
├── fpga : FPGA related code
└── sw : Software

First, install Vivado from https://www.xilinx.com/support/download/index.html/content/xilinx/en/downloadNav/vivado-design-tools/2022-1.html It is recommended to install it to /opt, as the Podman/Docker environment assumes it to be there.

First, setup the repository:

git clone --recurse-submodules https://github.com/cyberchrime/farts.git
cd farts

Afterwards, setup the container. For Podman, use

podman build -t sniffer docker
podman run -ti --userns=keep-id -v=/opt/Xilinx:/opt/Xilinx:Z -v=.:/home/sniffer/ws:Z --rm sniffer:latest

When using docker, use these commands instead:

docker build -t sniffer docker
docker run -ti -v=/opt/Xilinx:/opt/Xilinx -v=${PWD}:/home/sniffer/ws --rm sniffer:latest

Once you entered the shell inside the container, you can build it with make (without parallelisation). No need to use -j, as all executed commands (Vivado and BitBake) already make heavy use of parallelisation. Execute

LD_PRELOAD=/lib/x86_64-linux-gnu/libudev.so.1 make

If you'd like to use Vivado with a GUI, run xhost + on your host machine.

The build results are contained in `sw/build/tmp-glibc/deploy/images/zedboard-zynq7/

Prepare a SD-Card by formatting it as follows:

• At the beginning, 4MB of free space
• Then FAT32 formatted first partition (500MB) named BOOT
• remaining space ext4 formatted and named RootFS

Finally, mount the SD card and run the following commands to install the software:

mkdir -p /<mnt-path>/BOOT/boot/extlinux
cp boot.bin /<mnt-path>/BOOT/
cp extlinux.conf /<mnt-path>/BOOT/boot/extlinux/
cp system.dtb /<mnt-path>/BOOT/boot
cp zImage /<mnt-path>/BOOT/boot
tar xf core-image-minimal-zedboard-zynq7.tar.gz -C /<mnt-path>/RootFS

To start sniffing, connect the device in between two other Ethernet devices. Additionally, connect a micro USB cable to the board and connect via a serial console, e.g. with picocom:

picocom -b 115200 /dev/ttyUSB0

Then login to the console with user root — no password required. Afterwards, start sniffing with

file=capture.pcap; header > $file; cat /dev/sniffer >> $file

To stop monitoring, simply press CTRL-C.

It is possible to view some statistics about the previous capture in the files represented located in this directory:

/sys/devices/soc0/40000000.sniffer/