README.md

An eBPF-based packet filtering framework.

bpfilter is an eBPF-based packet filtering framework designed to translate filtering rules into BPF programs. It comprises three main components:

1. A daemon that runs on the host, translating filtering rules into BPF programs.
2. A lightweight library to facilitate communication with the daemon.
3. A dedicated command line interface to define the filtering rules.

A typical usage workflow would be to start the bpfilter daemon, then define the filtering rules using bfcli (part of the bpfilter project), nftables or iptables. The bpfilter daemon will be responsible for translating the filtering rules into custom BPF programs, and loading them on the system.

Detailed information can be found in the documentation.

Quick start guide (Fedora 41)

1. Install dependencies

   # To build bpfilter
   sudo dnf install -y bison bpftool clang clang-tools-extra cmake doxygen flex g++ gcc git jq lcov libasan libbpf-devel libcmocka-devel libnl3-devel libubsan pkgconf python3-breathe python3-furo python3-linuxdoc python3-sphinx
   
   # To build nftables and iptables
   sudo dnf install -y autoconf automake git gmp-devel libtool libedit-devel libmnl-devel libnftnl-devel

2. Build bpfilter

   cmake -S $SOURCES_DIR -B $BUILD_DIR
   make -C $BUILD_DIR
   make -C $BUILD_DIR test

3. Build custom versions of nftables and iptables (optional)

   make -C $BUILD_DIR nftables iptables

4. Start the bpfilter daemon

   sudo $BUILD_DIR/src/bpfilter

5. Configure the filtering rules

   • For bfcli:

     $BUILD_DIR/output/bin/bfcli --file $RULESET

   • For nftables:

     sudo $BUILD_DIR/tools/install/sbin/nft --bpf ...

   • For iptables:

     sudo $BUILD_DIR/tools/install/sbin/iptables --bpf ...

License

bpfilter is licensed under GPLv2. You can find the licensing details in the COPYING file.

Acknowledgements

bpfilter was initially developed by Dmitrii Banshchikov as a Linux kernel usermode helper.

For further information and updates, visit the bpfilter documentation.