fwrouter

eBPF routing to/from interface devices on a host machine.

Dependencies

llvm >= 10
clang >= 10
libelf
Ubuntu >= 18.04 LTS
libbpf & bpftool

Add the appropriate repository:

add-apt-repository 'deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-10  main'

Update packages: sudo apt update.
Install the dependencies:

sudo apt-get install llvm-10     \
                     lldb-10     \
                     llvm-10-dev \
                     libllvm10   \
                     llvm-10-runtime \
                     clang-10    \
                     gcc-multilib

sudo ln -s /usr/bin/llvm-strip-10 /usr/bin/llvm-strip
sudo ln -s /usr/bin/clang-10 /usr/bin/clang

Installing libbpf

Ubuntu versions older than 20.04 dont come with libbpf built-in thus, we need to manually install the library from source in order to use its provided bpf helpers.

Clone the git repo of libbpf into you're work machine: git clone https://github.com/libbpf/libbpf.git
Run the following commands:

cd /src
sudo make install

Once installed you can make sure that the required headers are in the file system under /usr/include/bpf.

FAQ

debugging maps, programs, etc.

Use the bpftool to debug maps, programs, etc. To download run: sudo apt install linux-tools-common.

where are my 'bpf_printk' logs?

Run the following command: sudo cat /sys/kernel/debug/tracing/trace_pipe

how to run `fwrouter`?

Compile the program using make, followed by: sudo ./fwrouter run

how to verify the program is loaded properly?

Use the following command: ip link, and find the added interfaces listed. To see the bpf filter added use the following: sudo tc -s -d filter show dev eth0 ingress.

how to remove the qdisc added by this program manually?

Use the following command to remove the qdisc: sudo tc qdisc del dev eth0 clsact.

nimrodshn/fwrouter