Liminix

A Nix-based system for configuring consumer wifi routers.

What is this?

This is a Nix-based collection of software tailored for domestic wifi router or IoT device devices, of the kind that OpenWrt or DD-WRT or Gargoyle or Tomato run on. It's a reboot/restart/rewrite of NixWRT.

This is not NixOS-on-your-router: it's aimed at devices that are underpowered for the full NixOS experience. It uses busybox tools, musl instead of GNU libc, and s6-rc instead of systemd.

The Liminix name comes from Liminis, in Latin the genitive declension of "limen", or "of the threshold". Your router stands at the threshold of your (online) home and everything you send to/receive from the outside word goes across it.

Building

These instructions assume you have nixpkgs checked out in a peer directory of this one.

You need a configuration.nix file pointed to by <liminix-config>, a hardware device definition as argument device, and to choose an appropriate output attribute depending on what your device is and how you plan to install onto it. For example:

NIX_PATH=nixpkgs=../nixpkgs:$NIX_PATH NIXPKGS_ALLOW_UNSUPPORTED_SYSTEM=1 nix-build -I liminix-config=./tests/smoke/configuration.nix --arg device "import ./devices/qemu.nix" -A outputs.default

outputs.default is intended to do something appropriate for the device, whatever that is. For the qemu device, it creates a directory containing a squashfs root image and a kernel, with which you could then run

./run-qemu.sh result/vmlinux result/squashfs

Running tests

Assuming you have nixpkgs checked out in a peer directory of this one,

NIX_PATH=nixpkgs=../nixpkgs:$NIX_PATH ./run-tests.sh

Articles of interest

• Build Safety of Software in 28 Popular Home Routers: "of the access points and routers we reviewed, not a single one took full advantage of the basic application armoring features provided by the operating system. Indeed, only one or two models even came close, and no brand did well consistently across all models tested"