Gatekeeper – First Open-Source DDoS Protection System

Gatekeeper is the first open source DoS protection system. It is designed to scale to any peak bandwidth, so it can withstand DoS attacks both of today and of tomorrow. In spite of the geographically distributed architecture of Gatekeeper, the network policy that describes all decisions that have to be enforced on the incoming traffic is centralized. This centralized policy enables network operators to leverage distributed algorithms that would not be viable under very high latency (e.g. distributed databases) and to fight multiple multi-vector DoS attacks at once.

The intended users of Gatekeeper are network operators of institutions, service and content providers, enterprise networks, etc. It is not intended to be used by individual Internet users.

For more information, see the Gatekeeper wiki.

How to Set Up

Configure Hugepages

DPDK requires the use of hugepages; instructions for mounting hugepages are available in the requirements documentation. On many systems, the following hugepages setup is sufficient:

$ echo 256 | sudo tee /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages

Option 1: Obtain Packages

Debian packages for Gatekeeper are available at the project’s Releases page.

Install

Once the packages are downloaded, they can be installed with the commands below:

$ tar -zxvf gatekeeper-ubuntu-18.04-packages.tar.gz
$ cd gatekeeper-ubuntu-18.04-packages
$ sudo dpkg -i libgkrte-*.deb 
    libgkdpdk-dev_*_amd64.deb 
    gatekeeper-dpdk_*_amd64.deb 
    gatekeeper-dpdk-dev_*_amd64.deb 
    gatekeeper-dpdk-igb-uio-dkms_*_amd64.deb 
    gatekeeper-dpdk-rte-kni-dkms_*_amd64.deb 
    gatekeeper-bird_*_amd64.deb 
    gatekeeper_*_amd64.deb

The gatekeeper-dpdk-dev package is a dependency of the DKMS packages, which build their respective kernel modules during package installation and kernel upgrades.

Configure Network Adapters

Edit the /etc/gatekeeper/envvars file and insert names of the network adapters to be bound to DPDK. For example:

GATEKEEPER_INTERFACES="eth0 eth1"

Alternatively, the interfaces’ PCI addresses can be specified:

GATEKEEPER_INTERFACES="0000:00:07.0 0000:00:08.0"

In the same file, you can optionally specify Environmental Abstraction Layer options in the DPDK_ARGS variable and Gatekeeper-specific options in GATEKEEPER_ARGS.

How to run

Run the commands below to start Gatekeeper and to ensure it is started automatically on reboots.

$ sudo systemctl start gatekeeper
$ sudo systemctl enable gatekeeper

Option 2: Build from Source

Install Dependencies

Install the following software dependencies:

$ sudo apt-get update
$ sudo apt-get -y -q install git clang devscripts doxygen hugepages 
build-essential linux-headers-`uname -r` libmnl0 libmnl-dev 
libkmod2 libkmod-dev libnuma-dev libelf1 libelf-dev libc6-dev-i386 
autoconf flex bison libncurses5-dev libreadline-dev

Note: Both libmnl0 and libmnl-dev are needed to compile and run gatekeeper, but only libmnl0 is needed for simply running gatekeeper. Both libkmod2 and libkmod-dev are needed to compile and run gatekeeper, but only libkmod2 is needed for simply running gatekeeper. libnuma-dev is needed to compile the latest DPDK and to support NUMA systems. The package libelf-dev is needed to compile DPDK with support to reading BPF programs from ELF files, but only libelf1 is needed to run it. The package libc6-dev-i386 is needed to compile the BPF programs in the folder bpf/. The autoconf, flex, bison, libncurses5-dev, and libreadline-dev packages are for BIRD. The devscripts package is used to build Gatekeeper Debian packages.

To use DPDK, make sure you have all of the environmental requirements.

Clone Repository

Clone the Gatekeeper repository, including the submodules that contain Gatekeeper dependencies:

$ git clone --recursive http://github.com/AltraMayor/gatekeeper.git

If you do not use the --recursive clone option, you need to obtain the submodules that contain the dependences from within the gatekeeper directory:

$ git submodule init
$ git submodule update

Compile

This section explains how to build Gatekeeper manually. If you want to build Debian packages, refer to the section How to build packages.

While in the gatekeeper directory, run the setup script:

$ . setup.sh

This script compiles DPDK, LuaJIT, and BIRD, and loads the needed kernel modules. Additionally, it saves the interface names and their respective PCI addresses in the file lua/if_map.lua so that interface names can be used in the Gatekeeper configuration files.

It also sets two environmental variables: RTE_SDK and RTE_TARGET. They must be set before gatekeeper will compile.

After running the setup script, you may want to save the environmental variables in your shell’s preferences file. For example, in Bash, you can do:

$ echo "export RTE_SDK=${RTE_SDK}" >> ${HOME}/.profile
$ echo "export RTE_TARGET=${RTE_TARGET}" >> ${HOME}/.profile

Otherwise, each time you login you will need to set these environmental variables again.

Once DPDK is compiled and the variables are set, gatekeeper can be compiled:

$ make

Configure Network Adapters

Before gatekeeper can be used, the network adapters must be bound to DPDK. For this, you can use the script dependencies/dpdk/usertools/dpdk-devbind.py. For example:

$ sudo dependencies/dpdk/usertools/dpdk-devbind.py --bind=uio_pci_generic enp131s0f0

This command binds the interface enp131s0f0 to the uio_pci_generic driver so that frames can be passed directly to DPDK instead of the kernel. Note that this binding must take place after Gatekeeper is setup in the steps above so that the bound interface appears in the list of interfaces in lua/if_map.lua.

How to Run

Once gatekeeper is compiled and the environment is configured correctly, run:

$ sudo build/gatekeeper [EAL OPTIONS] -- [GATEKEEPER OPTIONS]

Where [EAL OPTIONS] are specified before a double dash and represent the parameters for DPDK’s Environmental Abstraction Layer and [GATEKEEPER OPTIONS] are specified after the double dash and represent Gatekeeper-specific options.

The early configuration of the system, including device and memory configuration in DPDK, will be logged to stdout. Once Gatekeeper is booted, all information is output to the Gatekeeper log.

How to build packages

Gatekeeper Debian packages can be built with the commands below. They are meant to be run from the repository root and assume the git submodules have been pulled, and that the build dependencies have been installed, as instructed above. Gatekeeper and the submodules will be automatically compiled during the package build process.

$ tar --exclude-vcs -Jcvf ../gatekeeper_1.0.0.orig.tar.xz -C .. gatekeeper
$ debuild -uc -us

The Gatekeeper package will be available in the parent directory.