1 files changed, 164 insertions, 0 deletions
diff --git a/lass/3modules/xjail.nix b/lass/3modules/xjail.nix
new file mode 100644
index 000000000..325ebcc99
--- /dev/null
+++ b/lass/3modules/xjail.nix
@@ -0,0 +1,164 @@
+{ config, pkgs, lib, ... }:
+
+with import <stockholm/lib>;
+{
+  options.lass.xjail = mkOption {
+    type = types.attrsOf (types.submodule ({ config, ...}: {
+      options = {
+        name = mkOption {
+          type = types.string;
+          default = config._module.args.name;
+        };
+        user = mkOption {
+          type = types.string;
+          default = config.name;
+        };
+        groups = mkOption {
+          type = types.listOf types.str;
+          default = [];
+        };
+        from = mkOption {
+          type = types.string;
+          default = "lass";
+        };
+        display = mkOption {
+          type = types.string;
+          default = toString (genid_signed config._module.args.name);
+        };
+        dpi = mkOption {
+          type = types.int;
+          default = 90;
+        };
+        extraXephyrArgs = mkOption {
+          type = types.str;
+          default = "";
+        };
+        extraVglrunArgs = mkOption {
+          type = types.str;
+          default = "";
+        };
+        script = mkOption {
+          type = types.path;
+          default = pkgs.writeScript "echo_lol" "echo lol";
+        };
+        wm = mkOption {
+          #TODO find type
+          type = types.string;
+          default = "${pkgs.writeHaskell "xephyrify-xmonad" {
+            executables.xmonad = {
+              extra-depends = [
+                "containers"
+                "unix"
+                "xmonad"
+              ];
+              text = /* haskell */ ''
+                module Main where
+                import XMonad
+                import Data.Monoid
+                import System.Posix.Process (executeFile)
+                import qualified Data.Map as Map
+
+                main :: IO ()
+                main = do
+                  xmonad def
+                    { workspaces = [ "1" ]
+                    , layoutHook = myLayoutHook
+                    , keys = myKeys
+                    , normalBorderColor  = "#000000"
+                    , focusedBorderColor = "#000000"
+                    , handleEventHook = myEventHook
+                    }
+
+                myEventHook :: Event -> X All
+
+                myEventHook (ConfigureEvent { ev_event_type = 22 }) = do
+                  spawn "${pkgs.xorg.xrandr}/bin/xrandr >/dev/null 2>&1"
+                  return (All True)
+
+                myEventHook _ = do
+                  return (All True)
+
+                myLayoutHook = Full
+                myKeys _ = Map.fromList []
+              '';
+            };
+          }}/bin/xmonad";
+        };
+      };
+    }));
+    default = {};
+  };
+
+  options.lass.xjail-bins = mkOption {
+    type = types.attrsOf types.path;
+  };
+
+  # implementation
+  config = let
+    scripts = mapAttrs' (name: cfg:
+      let
+        newOrExisting = pkgs.writeDash "${cfg.name}-existing" ''
+          DISPLAY=:${cfg.display} ${pkgs.xorg.xrandr}/bin/xrandr
+          if test $? -eq 0; then
+            echo using existing xephyr
+            ${sudo_} "$@"
+          else
+            echo starting new xephyr
+            ${xephyr_} "$@"
+          fi
+        '';
+        xephyr_ = pkgs.writeDash "${cfg.name}-xephyr" ''
+          ${pkgs.xorg.xorgserver}/bin/Xephyr -br -ac -reset -terminate -resizeable -nolisten local -dpi ${toString cfg.dpi} ${cfg.extraXephyrArgs} :${cfg.display} &
+          XEPHYR_PID=$!
+          DISPLAY=:${cfg.display} ${cfg.wm} &
+          WM_PID=$!
+          ${sudo_} "$@"
+          ${pkgs.coreutils}/bin/kill $WM_PID
+          ${pkgs.coreutils}/bin/kill $XEPHYR_PID
+        '';
+        sudo_ = pkgs.writeDash "${cfg.name}-sudo" ''
+          /var/run/wrappers/bin/sudo -u ${cfg.name} -i ${vglrun_} "$@"
+        '';
+        vglrun_ = pkgs.writeDash "${cfg.name}-vglrun" ''
+          DISPLAY=:${cfg.display} ${pkgs.virtualgl}/bin/vglrun ${cfg.extraVglrunArgs} ${cfg.script} "$@"
+        '';
+      in nameValuePair name {
+        existing = newOrExisting;
+        xephyr = xephyr_;
+        sudo = sudo_;
+        vglrun = vglrun_;
+      }
+    ) config.lass.xjail;
+  in {
+
+    users.users = mapAttrs' (_: cfg:
+      nameValuePair cfg.name {
+        uid = genid cfg.name;
+        home = "/home/${cfg.name}";
+        useDefaultShell = true;
+        createHome = true;
+        extraGroups = cfg.groups;
+      }
+    ) config.lass.xjail;
+
+    users.groups = mapAttrs' (_: cfg:
+      nameValuePair cfg.name {
+        members = [
+          cfg.name
+          cfg.from
+        ];
+      }
+    ) config.lass.xjail;
+
+    security.sudo.extraConfig = (concatStringsSep "\n" (mapAttrsToList (_: cfg:
+      # TODO allow just the right script with sudo
+      "${cfg.from} ALL=(${cfg.name}) NOPASSWD: ALL"
+    ) config.lass.xjail));
+
+    lass.xjail-bins = mapAttrs' (name: cfg:
+      nameValuePair name (pkgs.writeScriptBin cfg.name ''
+        ${scripts.${name}.existing} "$@"
+      '')
+    ) config.lass.xjail;
+  };
+}