feat: introduce iproute2 module for linkage

In the future, we will make it possible to choose between iproute2 and
busybox more properly.

Signed-off-by: Raito Bezarius <masterancpp@gmail.com>

lib/eval-config.nix

@@ -12,6 +12,7 @@ in
     "${modulesPath}/hardware.nix"
     "${modulesPath}/base.nix"
     "${modulesPath}/busybox.nix"
+    "${modulesPath}/iproute2.nix"
     "${modulesPath}/hostname.nix"
     "${modulesPath}/kernel"
     "${modulesPath}/s6"

modules/all-modules.nix

@@ -4,9 +4,10 @@
 
 {
   imports = [
-   ./base.nix
+    ./base.nix
    ./bridge
    ./busybox.nix
+   ./iproute2.nix
    ./dhcp6c
    ./jitter-rng
    ./dnsmasq

modules/iproute2.nix

@@ -0,0 +1,28 @@
+{ config, pkgs, lib, ... }:
+let
+  inherit (lib) mkEnableOption mkPackageOption mkIf genAttrs;
+  inherit (pkgs.pseudofile) dir symlink;
+  cfg = config.programs.iproute2;
+  minimalPrograms = [
+    "ip"
+    "devlink"
+    "ss"
+    "bridge"
+    "genl"
+    "ifstat"
+    "nstat"
+  ];
+  links = genAttrs minimalPrograms (p: symlink "${cfg.package}/bin/${p}");
+in
+{
+  options.programs.iproute2 = {
+    enable = mkEnableOption "the iproute2 programs instead of busybox variants";
+    package = mkPackageOption pkgs "iproute2" { };
+  };
+
+  config = mkIf cfg.enable {
+    filesystem = dir {
+      bin = dir links;
+    };
+  };
+}

overlay.nix

@@ -210,6 +210,10 @@ extraPkgs // {
         echo "Removing unnecessary binary $out/sbin/$needless_binary"
         rm "$out/sbin/$needless_binary"
       done
+      # No man
+      rm -rf "$out/share"
+      # Remove all the data about distributions for tc.
+      rm -rf "$out/lib"
     '';
   });
   # Don't bring ebpf stuff to the table.