{
  description = "Sparse C2 framework";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-24.11";

    rust-overlay = {
      url = "github:oxalica/rust-overlay";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    crane.url = "github:ipetkov/crane";
    flake-utils.url = "github:numtide/flake-utils";

    libpcap-src = {
      url = "git+https://github.com/the-tcpdump-group/libpcap";
      flake = false;
    };
    libnl-src = {
      url = "git+https://github.com/thom311/libnl";
      flake = false;
    };
    winpcap-libs = {
      url = "https://www.winpcap.org/install/bin/WpdPack_4_1_2.zip";
      flake = false;
    };
    winpcap-installer = {
      url = "https://www.winpcap.org/install/bin/WinPcap_4_1_3.exe";
      flake = false;
    };
    freebsd-libs-packed = {
      url = "https://download.freebsd.org/releases/amd64/14.1-RELEASE/base.txz";
      flake = false;
    };
    # command for later:
    # echo '000007: 09' | xxd -r - target/x86_64-unknown-freebsd/debug/sparse-beacon
  };

  outputs = { self, nixpkgs, flake-utils, crane, rust-overlay, libpcap-src
    , libnl-src, winpcap-libs, winpcap-installer, freebsd-libs-packed }:
    flake-utils.lib.eachSystem [ "x86_64-linux" ] (system:
      let
        pkgs = import nixpkgs {
          inherit system;
          overlays = [ (import rust-overlay) ];
        };

        system-libs = import ./system-libs.nix {
          inherit pkgs libnl-src libpcap-src winpcap-installer
            freebsd-libs-packed;
        };
        inherit (system-libs)
          bsd-toolchain winpcap-drivers freebsd-libs libnl libpcap-linux
          libpcap-freebsd;

        buildTools = with pkgs; [
          mold
          lld
          zig
          clang
          glibc

          pkgsCross.x86_64-freebsd.buildPackages.clang
          pkgsCross.mingwW64.stdenv.cc
          pkgsCross.mingwW64.windows.pthreads
        ];

        devShellTools = with pkgs; [ rust-analyzer ];

        craneLib = (crane.mkLib pkgs).overrideToolchain (p:
          p.rust-bin.stable.latest.default.override {
            targets = [
              "x86_64-unknown-linux-gnu"
              "x86_64-unknown-linux-musl"
              "x86_64-pc-windows-gnu"
              "x86_64-unknown-freebsd"
            ];
          });

        patch-elf = header: drv: path:
          pkgs.stdenv.mkDerivation {
            name = "elf-patch-${header}";

            buildInputs = with pkgs; [ vim ];
          };
        patch-freebsd-elf = patch-elf 9;
      in {
        devShells = {
          default = craneLib.devShell {
            name = "sparse-default";

            packages = buildTools ++ devShellTools;

            SPARSE_BUILD_WINPCAP_LIBS = "${winpcap-libs}/Lib";
            SPARSE_BUILD_WINPCAP_DRIVERS = "${winpcap-drivers}/npf.sys";
            SPARSE_BUILD_LIBPCAP_LINUX = libpcap-linux;
            SPARSE_BUILD_LIBPCAP_FREEBSD = libpcap-freebsd;
            SPARSE_BUILD_LIBNL = libnl;

            FREEBSD_LIBS = freebsd-libs;

            RUSTFLAGS = "-Ctarget-feature=+crt-static";
          };
        };
      });
}