nixos/liboping: add module

This creates setcap wrappers for oping and noping to allow unprivileged
users to use those as well.

nixos/modules/module-list.nix

@@ -127,6 +127,7 @@
   ./programs/java.nix
   ./programs/kbdlight.nix
   ./programs/less.nix
+  ./programs/liboping.nix
   ./programs/light.nix
   ./programs/mosh.nix
   ./programs/mininet.nix

nixos/modules/programs/liboping.nix

@@ -0,0 +1,22 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.programs.liboping;
+in {
+  options.programs.liboping = {
+    enable = mkEnableOption "liboping";
+  };
+  config = mkIf cfg.enable {
+    environment.systemPackages = with pkgs; [ liboping ];
+    security.wrappers = mkMerge (map (
+      exec: {
+        "${exec}" = {
+          source = "${pkgs.liboping}/bin/${exec}";
+          capabilities = "cap_net_raw+p";
+        };
+      }
+    ) [ "oping" "noping" ]);
+  };
+}