Add firewall module

Also: tmproot tweaks

boxes/colony.nix

@@ -8,7 +8,22 @@
       };
     };
 
+    networking = {};
+
     my = {
+      firewall = {
+        trustedInterfaces = [ "blah" ];
+        nat = {
+          externalInterface = "eth0";
+          forwardPorts = [
+            {
+              proto = "tcp";
+              sourcePort = 2222;
+              destination = "127.0.0.1:22";
+            }
+          ];
+        };
+      };
       server.enable = true;
     };
   }