flat

Measure UDP and TCP flow latency for both IPv4 and IPv6 using eBPF.

This repo is the companion to my blog posts about eBPF at https://thegraynode.io/tags/flat/.

You can install flat in two ways.

1. Download the pre-compiled binary
2. Compile from source

Download and unpack the binary with the default garbage collection algorithm:

wget https://github.com/pouriyajamshidi/flat/releases/latest/download/flat.tar.gz
tar xvf flat.tar.gz

Or with the new green tea garbage collection algorithm:

wget https://github.com/pouriyajamshidi/flat/releases/latest/download/flat-greenteagc.tar.gz
tar xvf flat-greenteagc.tar.gz

Then check out the examples.

You will need Go, clang, and the libbpf and Linux kernel headers (on Debian/Ubuntu: sudo apt install clang libbpf-dev linux-libc-dev).

Clone the repository:

git clone https://github.com/pouriyajamshidi/flat

Change directory to flat:

cd flat

While at the root of project directory, to compile the C code and generate the helper functions, run:

go generate ./...

Compile the Go program:

go build -ldflags "-s -w" -o flat cmd/flat.go

Run it with elevated privileges:

# Replace eth0 with your desired interface name
sudo ./flat -i eth0
# Or
sudo ./flat -i eth0 -ip 1.1.1.1
# Or
sudo ./flat -i eth0 -port 53
# Or
sudo ./flat -i eth0 -ip 1.1.1.1 -port 53

When both -ip and -port are given, a flow must match both.

flat supports four flags at the moment:

Heavily inspired by flowlat.