core/system/base/polkit/files/polkit-0.117-duktape.patch

diff --git a/configure.ac b/configure.ac
index 5cedb4eca980f050fb5855ab577e93100adf8fec..6c274869f39d4b65b08f7cdb9e461b5182d297ec 100644
--- a/configure.ac
+++ b/configure.ac
@@ -79,11 +79,22 @@ PKG_CHECK_MODULES(GLIB, [gmodule-2.0 gio-unix-2.0 >= 2.30.0])
 AC_SUBST(GLIB_CFLAGS)
 AC_SUBST(GLIB_LIBS)
 
-PKG_CHECK_MODULES(LIBJS, [mozjs-68])
-
-AC_SUBST(LIBJS_CFLAGS)
-AC_SUBST(LIBJS_CXXFLAGS)
-AC_SUBST(LIBJS_LIBS)
+dnl ---------------------------------------------------------------------------
+dnl - Check javascript backend
+dnl ---------------------------------------------------------------------------
+AC_ARG_WITH(duktape, AS_HELP_STRING([--with-duktape],[Use Duktape as javascript backend]),with_duktape=yes,with_duktape=no)
+AS_IF([test x${with_duktape} == xyes], [
+  PKG_CHECK_MODULES(LIBJS, [duktape >= 2.0.0 ])
+  AC_SUBST(LIBJS_CFLAGS)
+  AC_SUBST(LIBJS_LIBS)
+], [
+  PKG_CHECK_MODULES(LIBJS, [mozjs-68])
+
+  AC_SUBST(LIBJS_CFLAGS)
+  AC_SUBST(LIBJS_CXXFLAGS)
+  AC_SUBST(LIBJS_LIBS)
+])
+AM_CONDITIONAL(USE_DUKTAPE, [test x$with_duktape == xyes], [Using duktape as javascript engine library])
 
 EXPAT_LIB=""
 AC_ARG_WITH(expat, [  --with-expat=<dir>      Use expat from here],
@@ -580,6 +591,13 @@ echo "
         PAM support:                ${have_pam}
         systemdsystemunitdir:       ${systemdsystemunitdir}
         polkitd user:               ${POLKITD_USER}"
+if test "x${with_duktape}" = xyes; then
+echo "
+        Javascript engine:          Duktape"
+else
+echo "
+        Javascript engine:          Mozjs"
+fi
 
 if test "$have_pam" = yes ; then
 echo "
diff --git a/src/polkitbackend/Makefile.am b/src/polkitbackend/Makefile.am
index e48b739cc0a4e7606be0271ba4b4e3bd33b08545..9572b067effdf6f0dcd1c6b17b2e8c59c1ed6238 100644
--- a/src/polkitbackend/Makefile.am
+++ b/src/polkitbackend/Makefile.am
@@ -33,7 +33,7 @@ libpolkit_backend_1_la_SOURCES =                                   			\
 	polkitbackendprivate.h								\
 	polkitbackendauthority.h		polkitbackendauthority.c		\
 	polkitbackendinteractiveauthority.h	polkitbackendinteractiveauthority.c	\
-	polkitbackendjsauthority.h		polkitbackendjsauthority.cpp		\
+	polkitbackendjsauthority.h				\
 	polkitbackendactionpool.h		polkitbackendactionpool.c		\
 	polkitbackendactionlookup.h		polkitbackendactionlookup.c		\
         $(NULL)
@@ -51,19 +51,27 @@ libpolkit_backend_1_la_CFLAGS =                                        	\
         -D_POLKIT_BACKEND_COMPILATION                                  	\
         $(GLIB_CFLAGS)							\
 	$(LIBSYSTEMD_CFLAGS)						\
-	$(LIBJS_CFLAGS)							\
+	$(LIBJS_CFLAGS)						\
         $(NULL)
 
 libpolkit_backend_1_la_CXXFLAGS = $(libpolkit_backend_1_la_CFLAGS)
 
 libpolkit_backend_1_la_LIBADD =                               		\
         $(GLIB_LIBS)							\
+        $(DUKTAPE_LIBS)							\
 	$(LIBSYSTEMD_LIBS)						\
 	$(top_builddir)/src/polkit/libpolkit-gobject-1.la		\
 	$(EXPAT_LIBS)							\
-	$(LIBJS_LIBS)							\
+	$(LIBJS_LIBS)                                                   \
         $(NULL)
 
+if USE_DUKTAPE
+libpolkit_backend_1_la_SOURCES += polkitbackendduktapeauthority.c
+libpolkit_backend_1_la_LIBADD += -lm
+else
+libpolkit_backend_1_la_SOURCES += polkitbackendjsauthority.cpp
+endif
+
 rulesdir = $(sysconfdir)/polkit-1/rules.d
 rules_DATA = 50-default.rules
 
diff --git a/src/polkitbackend/polkitbackendduktapeauthority.c b/src/polkitbackend/polkitbackendduktapeauthority.c
new file mode 100644
index 0000000000000000000000000000000000000000..ae984535ed88003ab1b0965e3e109a848479c047
--- /dev/null
+++ b/src/polkitbackend/polkitbackendduktapeauthority.c
@@ -0,0 +1,1402 @@
+/*
+ * Copyright (C) 2008-2012 Red Hat, Inc.
+ * Copyright (C) 2015 Tangent Space <jstpierre@mecheye.net>
+ * Copyright (C) 2019 Wu Xiaotian <yetist@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General
+ * Public License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Author: David Zeuthen <davidz@redhat.com>
+ */
+
+#include "config.h"
+#include <sys/wait.h>
+#include <errno.h>
+#include <pwd.h>
+#include <grp.h>
+#include <netdb.h>
+#include <string.h>
+#include <glib/gstdio.h>
+#include <locale.h>
+#include <glib/gi18n-lib.h>
+
+#include <polkit/polkit.h>
+#include "polkitbackendjsauthority.h"
+
+#include <polkit/polkitprivate.h>
+
+#ifdef HAVE_LIBSYSTEMD
+#include <systemd/sd-login.h>
+#endif /* HAVE_LIBSYSTEMD */
+
+#include "initjs.h" /* init.js */
+#include "duktape.h"
+
+/**
+ * SECTION:polkitbackendjsauthority
+ * @title: PolkitBackendJsAuthority
+ * @short_description: JS Authority
+ * @stability: Unstable
+ *
+ * An implementation of #PolkitBackendAuthority that reads and
+ * evalates Javascript files and supports interaction with
+ * authentication agents (virtue of being based on
+ * #PolkitBackendInteractiveAuthority).
+ */
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+struct _PolkitBackendJsAuthorityPrivate
+{
+  gchar **rules_dirs;
+  GFileMonitor **dir_monitors; /* NULL-terminated array of GFileMonitor instances */
+  duk_context *cx;
+};
+
+#define WATCHDOG_TIMEOUT (15 * G_TIME_SPAN_SECOND)
+
+static void utils_spawn (const gchar *const  *argv,
+                         guint                timeout_seconds,
+                         GCancellable        *cancellable,
+                         GAsyncReadyCallback  callback,
+                         gpointer             user_data);
+
+gboolean utils_spawn_finish (GAsyncResult   *res,
+                             gint           *out_exit_status,
+                             gchar         **out_standard_output,
+                             gchar         **out_standard_error,
+                             GError        **error);
+
+static void on_dir_monitor_changed (GFileMonitor     *monitor,
+                                    GFile            *file,
+                                    GFile            *other_file,
+                                    GFileMonitorEvent event_type,
+                                    gpointer          user_data);
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+enum
+{
+  PROP_0,
+  PROP_RULES_DIRS,
+};
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+static GList *polkit_backend_js_authority_get_admin_auth_identities (PolkitBackendInteractiveAuthority *authority,
+                                                                     PolkitSubject                     *caller,
+                                                                     PolkitSubject                     *subject,
+                                                                     PolkitIdentity                    *user_for_subject,
+                                                                     gboolean                           subject_is_local,
+                                                                     gboolean                           subject_is_active,
+                                                                     const gchar                       *action_id,
+                                                                     PolkitDetails                     *details);
+
+static PolkitImplicitAuthorization polkit_backend_js_authority_check_authorization_sync (
+                                                          PolkitBackendInteractiveAuthority *authority,
+                                                          PolkitSubject                     *caller,
+                                                          PolkitSubject                     *subject,
+                                                          PolkitIdentity                    *user_for_subject,
+                                                          gboolean                           subject_is_local,
+                                                          gboolean                           subject_is_active,
+                                                          const gchar                       *action_id,
+                                                          PolkitDetails                     *details,
+                                                          PolkitImplicitAuthorization        implicit);
+
+G_DEFINE_TYPE (PolkitBackendJsAuthority, polkit_backend_js_authority, POLKIT_BACKEND_TYPE_INTERACTIVE_AUTHORITY);
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+static void
+polkit_backend_js_authority_init (PolkitBackendJsAuthority *authority)
+{
+  authority->priv = G_TYPE_INSTANCE_GET_PRIVATE (authority,
+                                                 POLKIT_BACKEND_TYPE_JS_AUTHORITY,
+                                                 PolkitBackendJsAuthorityPrivate);
+}
+
+static gint
+rules_file_name_cmp (const gchar *a,
+                     const gchar *b)
+{
+  gint ret;
+  const gchar *a_base;
+  const gchar *b_base;
+
+  a_base = strrchr (a, '/');
+  b_base = strrchr (b, '/');
+
+  g_assert (a_base != NULL);
+  g_assert (b_base != NULL);
+  a_base += 1;
+  b_base += 1;
+
+  ret = g_strcmp0 (a_base, b_base);
+  if (ret == 0)
+    {
+      /* /etc wins over /usr */
+      ret = g_strcmp0 (a, b);
+      g_assert (ret != 0);
+    }
+
+  return ret;
+}
+
+static void
+load_scripts (PolkitBackendJsAuthority  *authority)
+{
+  duk_context *cx = authority->priv->cx;
+  GList *files = NULL;
+  GList *l;
+  guint num_scripts = 0;
+  GError *error = NULL;
+  guint n;
+
+  files = NULL;
+
+  for (n = 0; authority->priv->rules_dirs != NULL && authority->priv->rules_dirs[n] != NULL; n++)
+    {
+      const gchar *dir_name = authority->priv->rules_dirs[n];
+      GDir *dir = NULL;
+
+      polkit_backend_authority_log (POLKIT_BACKEND_AUTHORITY (authority),
+                                    "Loading rules from directory %s",
+                                    dir_name);
+
+      dir = g_dir_open (dir_name,
+                        0,
+                        &error);
+      if (dir == NULL)
+        {
+          polkit_backend_authority_log (POLKIT_BACKEND_AUTHORITY (authority),
+                                        "Error opening rules directory: %s (%s, %d)",
+                                        error->message, g_quark_to_string (error->domain), error->code);
+          g_clear_error (&error);
+        }
+      else
+        {
+          const gchar *name;
+          while ((name = g_dir_read_name (dir)) != NULL)
+            {
+              if (g_str_has_suffix (name, ".rules"))
+                files = g_list_prepend (files, g_strdup_printf ("%s/%s", dir_name, name));
+            }
+          g_dir_close (dir);
+        }
+    }
+
+  files = g_list_sort (files, (GCompareFunc) rules_file_name_cmp);
+
+  for (l = files; l != NULL; l = l->next)
+    {
+      const gchar *filename = l->data;
+
+#if (DUK_VERSION >= 20000)
+      gchar *contents;
+      gsize length;
+      GError *error = NULL;
+      if (!g_file_get_contents (filename, &contents, &length, &error)){
+        g_warning("Error when file contents of %s: %s\n", filename, error->message);
+        g_error_free (error);
+        continue;
+      }
+      if (duk_peval_lstring_noresult(cx, contents,length) != 0)
+#else
+      if (duk_peval_file_noresult (cx, filename) != 0)
+#endif
+        {
+          polkit_backend_authority_log (POLKIT_BACKEND_AUTHORITY (authority),
+                                        "Error compiling script %s: %s",
+                                        filename, duk_safe_to_string (authority->priv->cx, -1));
+#if (DUK_VERSION >= 20000)
+          g_free (contents);
+#endif
+          continue;
+        }
+#if (DUK_VERSION >= 20000)
+      g_free (contents);
+#endif
+      num_scripts++;
+    }
+
+  polkit_backend_authority_log (POLKIT_BACKEND_AUTHORITY (authority),
+                                "Finished loading, compiling and executing %d rules",
+                                num_scripts);
+  g_list_free_full (files, g_free);
+}
+
+static void
+reload_scripts (PolkitBackendJsAuthority *authority)
+{
+  duk_context *cx = authority->priv->cx;
+
+  duk_set_top (cx, 0);
+  duk_get_global_string (cx, "polkit");
+  duk_push_string (cx, "_deleteRules");
+
+  duk_call_prop (cx, 0, 0);
+
+  polkit_backend_authority_log (POLKIT_BACKEND_AUTHORITY (authority),
+                                "Collecting garbage unconditionally...");
+
+  load_scripts (authority);
+
+  /* Let applications know we have new rules... */
+  g_signal_emit_by_name (authority, "changed");
+}
+
+static void
+on_dir_monitor_changed (GFileMonitor     *monitor,
+                        GFile            *file,
+                        GFile            *other_file,
+                        GFileMonitorEvent event_type,
+                        gpointer          user_data)
+{
+  PolkitBackendJsAuthority *authority = POLKIT_BACKEND_JS_AUTHORITY (user_data);
+
+  /* TODO: maybe rate-limit so storms of events are collapsed into one with a 500ms resolution?
+   *       Because when editing a file with emacs we get 4-8 events..
+   */
+
+  if (file != NULL)
+    {
+      gchar *name;
+
+      name = g_file_get_basename (file);
+
+      /* g_print ("event_type=%d file=%p name=%s\n", event_type, file, name); */
+      if (!g_str_has_prefix (name, ".") &&
+          !g_str_has_prefix (name, "#") &&
+          g_str_has_suffix (name, ".rules") &&
+          (event_type == G_FILE_MONITOR_EVENT_CREATED ||
+           event_type == G_FILE_MONITOR_EVENT_DELETED ||
+           event_type == G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT))
+        {
+          polkit_backend_authority_log (POLKIT_BACKEND_AUTHORITY (authority),
+                                        "Reloading rules");
+          reload_scripts (authority);
+        }
+      g_free (name);
+    }
+}
+
+
+static void
+setup_file_monitors (PolkitBackendJsAuthority *authority)
+{
+  guint n;
+  GPtrArray *p;
+
+  p = g_ptr_array_new ();
+  for (n = 0; authority->priv->rules_dirs != NULL && authority->priv->rules_dirs[n] != NULL; n++)
+    {
+      GFile *file;
+      GError *error;
+      GFileMonitor *monitor;
+
+      file = g_file_new_for_path (authority->priv->rules_dirs[n]);
+      error = NULL;
+      monitor = g_file_monitor_directory (file,
+                                          G_FILE_MONITOR_NONE,
+                                          NULL,
+                                          &error);
+      g_object_unref (file);
+      if (monitor == NULL)
+        {
+          g_warning ("Error monitoring directory %s: %s",
+                     authority->priv->rules_dirs[n],
+                     error->message);
+          g_clear_error (&error);
+        }
+      else
+        {
+          g_signal_connect (monitor,
+                            "changed",
+                            G_CALLBACK (on_dir_monitor_changed),
+                            authority);
+          g_ptr_array_add (p, monitor);
+        }
+    }
+  g_ptr_array_add (p, NULL);
+  authority->priv->dir_monitors = (GFileMonitor**) g_ptr_array_free (p, FALSE);
+}
+
+static duk_ret_t js_polkit_log (duk_context *cx);
+static duk_ret_t js_polkit_spawn (duk_context *cx);
+static duk_ret_t js_polkit_user_is_in_netgroup (duk_context *cx);
+
+static const duk_function_list_entry js_polkit_functions[] =
+{
+  { "log", js_polkit_log, 1 },
+  { "spawn", js_polkit_spawn, 1 },
+  { "_userIsInNetGroup", js_polkit_user_is_in_netgroup, 2 },
+  { NULL, NULL, 0 },
+};
+
+static void
+polkit_backend_js_authority_constructed (GObject *object)
+{
+  PolkitBackendJsAuthority *authority = POLKIT_BACKEND_JS_AUTHORITY (object);
+  duk_context *cx;
+
+  cx = duk_create_heap (NULL, NULL, NULL, authority, NULL);
+  if (cx == NULL)
+    goto fail;
+
+  authority->priv->cx = cx;
+
+  duk_push_global_object (cx);
+  duk_push_object (cx);
+  duk_put_function_list (cx, -1, js_polkit_functions);
+  duk_put_prop_string (cx, -2, "polkit");
+
+  duk_eval_string (cx, init_js);
+
+  if (authority->priv->rules_dirs == NULL)
+    {
+      authority->priv->rules_dirs = g_new0 (gchar *, 3);
+      authority->priv->rules_dirs[0] = g_strdup (PACKAGE_SYSCONF_DIR "/polkit-1/rules.d");
+      authority->priv->rules_dirs[1] = g_strdup (PACKAGE_DATA_DIR "/polkit-1/rules.d");
+    }
+
+  setup_file_monitors (authority);
+  load_scripts (authority);
+
+  G_OBJECT_CLASS (polkit_backend_js_authority_parent_class)->constructed (object);
+  return;
+
+ fail:
+  g_critical ("Error initializing JavaScript environment");
+  g_assert_not_reached ();
+}
+
+static void
+polkit_backend_js_authority_finalize (GObject *object)
+{
+  PolkitBackendJsAuthority *authority = POLKIT_BACKEND_JS_AUTHORITY (object);
+  guint n;
+
+  for (n = 0; authority->priv->dir_monitors != NULL && authority->priv->dir_monitors[n] != NULL; n++)
+    {
+      GFileMonitor *monitor = authority->priv->dir_monitors[n];
+      g_signal_handlers_disconnect_by_func (monitor,
+                                            G_CALLBACK (on_dir_monitor_changed),
+                                            authority);
+      g_object_unref (monitor);
+    }
+  g_free (authority->priv->dir_monitors);
+  g_strfreev (authority->priv->rules_dirs);
+
+  duk_destroy_heap (authority->priv->cx);
+
+  G_OBJECT_CLASS (polkit_backend_js_authority_parent_class)->finalize (object);
+}
+
+static void
+polkit_backend_js_authority_set_property (GObject      *object,
+                                          guint         property_id,
+                                          const GValue *value,
+                                          GParamSpec   *pspec)
+{
+  PolkitBackendJsAuthority *authority = POLKIT_BACKEND_JS_AUTHORITY (object);
+
+  switch (property_id)
+    {
+      case PROP_RULES_DIRS:
+        g_assert (authority->priv->rules_dirs == NULL);
+        authority->priv->rules_dirs = (gchar **) g_value_dup_boxed (value);
+        break;
+
+      default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+        break;
+    }
+}
+
+static const gchar *
+polkit_backend_js_authority_get_name (PolkitBackendAuthority *authority)
+{
+  return "js";
+}
+
+static const gchar *
+polkit_backend_js_authority_get_version (PolkitBackendAuthority *authority)
+{
+  return PACKAGE_VERSION;
+}
+
+static PolkitAuthorityFeatures
+polkit_backend_js_authority_get_features (PolkitBackendAuthority *authority)
+{
+  return POLKIT_AUTHORITY_FEATURES_TEMPORARY_AUTHORIZATION;
+}
+
+static void
+polkit_backend_js_authority_class_init (PolkitBackendJsAuthorityClass *klass)
+{
+  GObjectClass *gobject_class;
+  PolkitBackendAuthorityClass *authority_class;
+  PolkitBackendInteractiveAuthorityClass *interactive_authority_class;
+
+
+  gobject_class = G_OBJECT_CLASS (klass);
+  gobject_class->finalize                               = polkit_backend_js_authority_finalize;
+  gobject_class->set_property                           = polkit_backend_js_authority_set_property;
+  gobject_class->constructed                            = polkit_backend_js_authority_constructed;
+
+  authority_class = POLKIT_BACKEND_AUTHORITY_CLASS (klass);
+  authority_class->get_name                             = polkit_backend_js_authority_get_name;
+  authority_class->get_version                          = polkit_backend_js_authority_get_version;
+  authority_class->get_features                         = polkit_backend_js_authority_get_features;
+
+  interactive_authority_class = POLKIT_BACKEND_INTERACTIVE_AUTHORITY_CLASS (klass);
+  interactive_authority_class->get_admin_identities     = polkit_backend_js_authority_get_admin_auth_identities;
+  interactive_authority_class->check_authorization_sync = polkit_backend_js_authority_check_authorization_sync;
+
+  g_object_class_install_property (gobject_class,
+                                   PROP_RULES_DIRS,
+                                   g_param_spec_boxed ("rules-dirs",
+                                                       NULL,
+                                                       NULL,
+                                                       G_TYPE_STRV,
+                                                       G_PARAM_CONSTRUCT_ONLY | G_PARAM_WRITABLE));
+
+
+  g_type_class_add_private (klass, sizeof (PolkitBackendJsAuthorityPrivate));
+}
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+static void
+set_property_str (duk_context *cx,
+                  const gchar *name,
+                  const gchar *value)
+{
+  duk_push_string (cx, value);
+  duk_put_prop_string (cx, -2, name);
+}
+
+static void
+set_property_strv (duk_context *cx,
+                   const gchar *name,
+                   GPtrArray   *value)
+{
+  guint n;
+  duk_push_array (cx);
+  for (n = 0; n < value->len; n++)
+    {
+      duk_push_string (cx, g_ptr_array_index (value, n));
+      duk_put_prop_index (cx, -2, n);
+    }
+  duk_put_prop_string (cx, -2, name);
+}
+
+static void
+set_property_int32 (duk_context *cx,
+                    const gchar *name,
+                    gint32       value)
+{
+  duk_push_int (cx, value);
+  duk_put_prop_string (cx, -2, name);
+}
+
+static void
+set_property_bool (duk_context *cx,
+                   const char  *name,
+                   gboolean     value)
+{
+  duk_push_boolean (cx, value);
+  duk_put_prop_string (cx, -2, name);
+}
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+static gboolean
+push_subject (duk_context               *cx,
+              PolkitSubject             *subject,
+              PolkitIdentity            *user_for_subject,
+              gboolean                   subject_is_local,
+              gboolean                   subject_is_active,
+              GError                   **error)
+{
+  gboolean ret = FALSE;
+  pid_t pid;
+  uid_t uid;
+  gchar *user_name = NULL;
+  GPtrArray *groups = NULL;
+  struct passwd *passwd;
+  char *seat_str = NULL;
+  char *session_str = NULL;
+
+  duk_get_global_string (cx, "Subject");
+  duk_new (cx, 0);
+
+  if (POLKIT_IS_UNIX_PROCESS (subject))
+    {
+      pid = polkit_unix_process_get_pid (POLKIT_UNIX_PROCESS (subject));
+    }
+  else if (POLKIT_IS_SYSTEM_BUS_NAME (subject))
+    {
+      PolkitSubject *process;
+      process = polkit_system_bus_name_get_process_sync (POLKIT_SYSTEM_BUS_NAME (subject), NULL, error);
+      if (process == NULL)
+        goto out;
+      pid = polkit_unix_process_get_pid (POLKIT_UNIX_PROCESS (process));
+      g_object_unref (process);
+    }
+  else
+    {
+      g_assert_not_reached ();
+    }
+
+#ifdef HAVE_LIBSYSTEMD
+  if (sd_pid_get_session (pid, &session_str) == 0)
+    {
+      if (sd_session_get_seat (session_str, &seat_str) == 0)
+        {
+          /* do nothing */
+        }
+    }
+#endif /* HAVE_LIBSYSTEMD */
+
+  g_assert (POLKIT_IS_UNIX_USER (user_for_subject));
+  uid = polkit_unix_user_get_uid (POLKIT_UNIX_USER (user_for_subject));
+
+  groups = g_ptr_array_new_with_free_func (g_free);
+
+  passwd = getpwuid (uid);
+  if (passwd == NULL)
+    {
+      user_name = g_strdup_printf ("%d", (gint) uid);
+      g_warning ("Error looking up info for uid %d: %m", (gint) uid);
+    }
+  else
+    {
+      gid_t gids[512];
+      int num_gids = 512;
+
+      user_name = g_strdup (passwd->pw_name);
+
+      if (getgrouplist (passwd->pw_name,
+                        passwd->pw_gid,
+                        gids,
+                        &num_gids) < 0)
+        {
+          g_warning ("Error looking up groups for uid %d: %m", (gint) uid);
+        }
+      else
+        {
+          gint n;
+          for (n = 0; n < num_gids; n++)
+            {
+              struct group *group;
+              group = getgrgid (gids[n]);
+              if (group == NULL)
+                {
+                  g_ptr_array_add (groups, g_strdup_printf ("%d", (gint) gids[n]));
+                }
+              else
+                {
+                  g_ptr_array_add (groups, g_strdup (group->gr_name));
+                }
+            }
+        }
+    }
+
+  set_property_int32 (cx, "pid", pid);
+  set_property_str (cx, "user", user_name);
+  set_property_strv (cx, "groups", groups);
+  set_property_str (cx, "seat", seat_str);
+  set_property_str (cx, "session", session_str);
+  set_property_bool (cx, "local", subject_is_local);
+  set_property_bool (cx, "active", subject_is_active);
+
+  ret = TRUE;
+
+ out:
+  free (session_str);
+  free (seat_str);
+  g_free (user_name);
+  if (groups != NULL)
+    g_ptr_array_unref (groups);
+
+  return ret;
+}
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+static gboolean
+push_action_and_details (duk_context               *cx,
+                         const gchar               *action_id,
+                         PolkitDetails             *details,
+                         GError                   **error)
+{
+  gchar **keys;
+  guint n;
+
+  duk_get_global_string (cx, "Action");
+  duk_new (cx, 0);
+
+  set_property_str (cx, "id", action_id);
+
+  keys = polkit_details_get_keys (details);
+  for (n = 0; keys != NULL && keys[n] != NULL; n++)
+    {
+      gchar *key;
+      const gchar *value;
+      key = g_strdup_printf ("_detail_%s", keys[n]);
+      value = polkit_details_lookup (details, keys[n]);
+      set_property_str (cx, key, value);
+      g_free (key);
+    }
+  g_strfreev (keys);
+
+  return TRUE;
+}
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+static GList *
+polkit_backend_js_authority_get_admin_auth_identities (PolkitBackendInteractiveAuthority *_authority,
+                                                       PolkitSubject                     *caller,
+                                                       PolkitSubject                     *subject,
+                                                       PolkitIdentity                    *user_for_subject,
+                                                       gboolean                           subject_is_local,
+                                                       gboolean                           subject_is_active,
+                                                       const gchar                       *action_id,
+                                                       PolkitDetails                     *details)
+{
+  PolkitBackendJsAuthority *authority = POLKIT_BACKEND_JS_AUTHORITY (_authority);
+  GList *ret = NULL;
+  guint n;
+  GError *error = NULL;
+  const char *ret_str = NULL;
+  gchar **ret_strs = NULL;
+  duk_context *cx = authority->priv->cx;
+
+  duk_set_top (cx, 0);
+  duk_get_global_string (cx, "polkit");
+  duk_push_string (cx, "_runAdminRules");
+
+  if (!push_action_and_details (cx, action_id, details, &error))
+    {
+      polkit_backend_authority_log (POLKIT_BACKEND_AUTHORITY (authority),
+                                    "Error converting action and details to JS object: %s",
+                                    error->message);
+      g_clear_error (&error);
+      goto out;
+    }
+
+  if (!push_subject (cx, subject, user_for_subject, subject_is_local, subject_is_active, &error))
+    {
+      polkit_backend_authority_log (POLKIT_BACKEND_AUTHORITY (authority),
+                                    "Error converting subject to JS object: %s",
+                                    error->message);
+      g_clear_error (&error);
+      goto out;
+    }
+
+  if (duk_pcall_prop (cx, 0, 2) != DUK_ERR_NONE)
+    {
+      polkit_backend_authority_log (POLKIT_BACKEND_AUTHORITY (authority),
+                                    "Error evaluating admin rules: ",
+                                    duk_safe_to_string (cx, -1));
+      goto out;
+    }
+
+  ret_str = duk_require_string (cx, -1);
+
+  ret_strs = g_strsplit (ret_str, ",", -1);
+  for (n = 0; ret_strs != NULL && ret_strs[n] != NULL; n++)
+    {
+      const gchar *identity_str = ret_strs[n];
+      PolkitIdentity *identity;
+
+      error = NULL;
+      identity = polkit_identity_from_string (identity_str, &error);
+      if (identity == NULL)
+        {
+          polkit_backend_authority_log (POLKIT_BACKEND_AUTHORITY (authority),
+                                        "Identity `%s' is not valid, ignoring: %s",
+                                        identity_str, error->message);
+          g_clear_error (&error);
+        }
+      else
+        {
+          ret = g_list_prepend (ret, identity);
+        }
+    }
+  ret = g_list_reverse (ret);
+
+ out:
+  g_strfreev (ret_strs);
+  /* fallback to root password auth */
+  if (ret == NULL)
+    ret = g_list_prepend (ret, polkit_unix_user_new (0));
+
+  return ret;
+}
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+static PolkitImplicitAuthorization
+polkit_backend_js_authority_check_authorization_sync (PolkitBackendInteractiveAuthority *_authority,
+                                                      PolkitSubject                     *caller,
+                                                      PolkitSubject                     *subject,
+                                                      PolkitIdentity                    *user_for_subject,
+                                                      gboolean                           subject_is_local,
+                                                      gboolean                           subject_is_active,
+                                                      const gchar                       *action_id,
+                                                      PolkitDetails                     *details,
+                                                      PolkitImplicitAuthorization        implicit)
+{
+  PolkitBackendJsAuthority *authority = POLKIT_BACKEND_JS_AUTHORITY (_authority);
+  PolkitImplicitAuthorization ret = implicit;
+  GError *error = NULL;
+  gchar *ret_str = NULL;
+  gboolean good = FALSE;
+  duk_context *cx = authority->priv->cx;
+
+  duk_set_top (cx, 0);
+  duk_get_global_string (cx, "polkit");
+  duk_push_string (cx, "_runRules");
+
+  if (!push_action_and_details (cx, action_id, details, &error))
+    {
+      polkit_backend_authority_log (POLKIT_BACKEND_AUTHORITY (authority),
+                                    "Error converting action and details to JS object: %s",
+                                    error->message);
+      g_clear_error (&error);
+      goto out;
+    }
+
+  if (!push_subject (cx, subject, user_for_subject, subject_is_local, subject_is_active, &error))
+    {
+      polkit_backend_authority_log (POLKIT_BACKEND_AUTHORITY (authority),
+                                    "Error converting subject to JS object: %s",
+                                    error->message);
+      g_clear_error (&error);
+      goto out;
+    }
+
+  if (duk_pcall_prop (cx, 0, 2) != DUK_ERR_NONE)
+  {
+      polkit_backend_authority_log (POLKIT_BACKEND_AUTHORITY (authority),
+                                    "Error evaluating authorization rules: ",
+                                    duk_safe_to_string (cx, -1));
+      goto out;
+  }
+
+  if (duk_is_null(cx, -1)) {
+    good = TRUE;
+    goto out;
+  }
+  ret_str = g_strdup (duk_require_string (cx, -1));
+  if (!polkit_implicit_authorization_from_string (ret_str, &ret))
+    {
+      polkit_backend_authority_log (POLKIT_BACKEND_AUTHORITY (authority),
+                                    "Returned result `%s' is not valid",
+                                    ret_str);
+      goto out;
+    }
+
+  good = TRUE;
+
+ out:
+  if (!good)
+    ret = POLKIT_IMPLICIT_AUTHORIZATION_NOT_AUTHORIZED;
+  g_free (ret_str);
+
+  return ret;
+}
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+static duk_ret_t
+js_polkit_log (duk_context *cx)
+{
+  const char *str = duk_require_string (cx, 0);
+  fprintf (stderr, "%s\n", str);
+  return 0;
+}
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+static const gchar *
+get_signal_name (gint signal_number)
+{
+  switch (signal_number)
+    {
+#define _HANDLE_SIG(sig) case sig: return #sig;
+    _HANDLE_SIG (SIGHUP);
+    _HANDLE_SIG (SIGINT);
+    _HANDLE_SIG (SIGQUIT);
+    _HANDLE_SIG (SIGILL);
+    _HANDLE_SIG (SIGABRT);
+    _HANDLE_SIG (SIGFPE);
+    _HANDLE_SIG (SIGKILL);
+    _HANDLE_SIG (SIGSEGV);
+    _HANDLE_SIG (SIGPIPE);
+    _HANDLE_SIG (SIGALRM);
+    _HANDLE_SIG (SIGTERM);
+    _HANDLE_SIG (SIGUSR1);
+    _HANDLE_SIG (SIGUSR2);
+    _HANDLE_SIG (SIGCHLD);
+    _HANDLE_SIG (SIGCONT);
+    _HANDLE_SIG (SIGSTOP);
+    _HANDLE_SIG (SIGTSTP);
+    _HANDLE_SIG (SIGTTIN);
+    _HANDLE_SIG (SIGTTOU);
+    _HANDLE_SIG (SIGBUS);
+#ifdef SIGPOLL
+    _HANDLE_SIG (SIGPOLL);
+#endif
+    _HANDLE_SIG (SIGPROF);
+    _HANDLE_SIG (SIGSYS);
+    _HANDLE_SIG (SIGTRAP);
+    _HANDLE_SIG (SIGURG);
+    _HANDLE_SIG (SIGVTALRM);
+    _HANDLE_SIG (SIGXCPU);
+    _HANDLE_SIG (SIGXFSZ);
+#undef _HANDLE_SIG
+    default:
+      break;
+    }
+  return "UNKNOWN_SIGNAL";
+}
+
+typedef struct
+{
+  GMainLoop *loop;
+  GAsyncResult *res;
+} SpawnData;
+
+static void
+spawn_cb (GObject       *source_object,
+          GAsyncResult  *res,
+          gpointer       user_data)
+{
+  SpawnData *data = user_data;
+  data->res = g_object_ref (res);
+  g_main_loop_quit (data->loop);
+}
+
+static duk_ret_t
+js_polkit_spawn (duk_context *cx)
+{
+#if (DUK_VERSION >= 20000)
+  duk_ret_t ret = DUK_RET_ERROR;
+#else
+  duk_ret_t ret = DUK_RET_INTERNAL_ERROR;
+#endif
+  gchar *standard_output = NULL;
+  gchar *standard_error = NULL;
+  gint exit_status;
+  GError *error = NULL;
+  guint32 array_len;
+  gchar **argv = NULL;
+  GMainContext *context = NULL;
+  GMainLoop *loop = NULL;
+  SpawnData data = {0};
+  char *err_str = NULL;
+  guint n;
+
+  if (!duk_is_array (cx, 0))
+    goto out;
+
+  array_len = duk_get_length (cx, 0);
+
+  argv = g_new0 (gchar*, array_len + 1);
+  for (n = 0; n < array_len; n++)
+    {
+      duk_get_prop_index (cx, 0, n);
+      argv[n] = g_strdup (duk_to_string (cx, -1));
+      duk_pop (cx);
+    }
+
+  context = g_main_context_new ();
+  loop = g_main_loop_new (context, FALSE);
+
+  g_main_context_push_thread_default (context);
+
+  data.loop = loop;
+  utils_spawn ((const gchar *const *) argv,
+               10, /* timeout_seconds */
+               NULL, /* cancellable */
+               spawn_cb,
+               &data);
+
+  g_main_loop_run (loop);
+
+  g_main_context_pop_thread_default (context);
+
+  if (!utils_spawn_finish (data.res,
+                           &exit_status,
+                           &standard_output,
+                           &standard_error,
+                           &error))
+    {
+      err_str = g_strdup_printf ("Error spawning helper: %s (%s, %d)",
+                                 error->message, g_quark_to_string (error->domain), error->code);
+      g_clear_error (&error);
+      goto out;
+    }
+
+  if (!(WIFEXITED (exit_status) && WEXITSTATUS (exit_status) == 0))
+    {
+      GString *gstr;
+      gstr = g_string_new (NULL);
+      if (WIFEXITED (exit_status))
+        {
+          g_string_append_printf (gstr,
+                                  "Helper exited with non-zero exit status %d",
+                                  WEXITSTATUS (exit_status));
+        }
+      else if (WIFSIGNALED (exit_status))
+        {
+          g_string_append_printf (gstr,
+                                  "Helper was signaled with signal %s (%d)",
+                                  get_signal_name (WTERMSIG (exit_status)),
+                                  WTERMSIG (exit_status));
+        }
+      g_string_append_printf (gstr, ", stdout=`%s', stderr=`%s'",
+                              standard_output, standard_error);
+      err_str = g_string_free (gstr, FALSE);
+      goto out;
+    }
+
+  duk_push_string (cx, standard_output);
+  ret = 1;
+
+ out:
+  g_strfreev (argv);
+  g_free (standard_output);
+  g_free (standard_error);
+  g_clear_object (&data.res);
+  if (loop != NULL)
+    g_main_loop_unref (loop);
+  if (context != NULL)
+    g_main_context_unref (context);
+
+  if (err_str)
+    duk_error (cx, DUK_ERR_ERROR, err_str);
+
+  return ret;
+}
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+
+static duk_ret_t
+js_polkit_user_is_in_netgroup (duk_context *cx)
+{
+  const char *user;
+  const char *netgroup;
+  gboolean is_in_netgroup = FALSE;
+
+  user = duk_require_string (cx, 0);
+  netgroup = duk_require_string (cx, 1);
+
+  if (innetgr (netgroup,
+               NULL,  /* host */
+               user,
+               NULL)) /* domain */
+    {
+      is_in_netgroup = TRUE;
+    }
+
+  duk_push_boolean (cx, is_in_netgroup);
+  return 1;
+}
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+typedef struct
+{
+  GSimpleAsyncResult *simple; /* borrowed reference */
+  GMainContext *main_context; /* may be NULL */
+
+  GCancellable *cancellable;  /* may be NULL */
+  gulong cancellable_handler_id;
+
+  GPid child_pid;
+  gint child_stdout_fd;
+  gint child_stderr_fd;
+
+  GIOChannel *child_stdout_channel;
+  GIOChannel *child_stderr_channel;
+
+  GSource *child_watch_source;
+  GSource *child_stdout_source;
+  GSource *child_stderr_source;
+
+  guint timeout_seconds;
+  gboolean timed_out;
+  GSource *timeout_source;
+
+  GString *child_stdout;
+  GString *child_stderr;
+
+  gint exit_status;
+} UtilsSpawnData;
+
+static void
+utils_child_watch_from_release_cb (GPid     pid,
+                                   gint     status,
+                                   gpointer user_data)
+{
+}
+
+static void
+utils_spawn_data_free (UtilsSpawnData *data)
+{
+  if (data->timeout_source != NULL)
+    {
+      g_source_destroy (data->timeout_source);
+      data->timeout_source = NULL;
+    }
+
+  /* Nuke the child, if necessary */
+  if (data->child_watch_source != NULL)
+    {
+      g_source_destroy (data->child_watch_source);
+      data->child_watch_source = NULL;
+    }
+
+  if (data->child_pid != 0)
+    {
+      GSource *source;
+      kill (data->child_pid, SIGTERM);
+      /* OK, we need to reap for the child ourselves - we don't want
+       * to use waitpid() because that might block the calling
+       * thread (the child might handle SIGTERM and use several
+       * seconds for cleanup/rollback).
+       *
+       * So we use GChildWatch instead.
+       *
+       * Avoid taking a references to ourselves. but note that we need
+       * to pass the GSource so we can nuke it once handled.
+       */
+      source = g_child_watch_source_new (data->child_pid);
+      g_source_set_callback (source,
+                             (GSourceFunc) utils_child_watch_from_release_cb,
+                             source,
+                             (GDestroyNotify) g_source_destroy);
+      g_source_attach (source, data->main_context);
+      g_source_unref (source);
+      data->child_pid = 0;
+    }
+
+  if (data->child_stdout != NULL)
+    {
+      g_string_free (data->child_stdout, TRUE);
+      data->child_stdout = NULL;
+    }
+
+  if (data->child_stderr != NULL)
+    {
+      g_string_free (data->child_stderr, TRUE);
+      data->child_stderr = NULL;
+    }
+
+  if (data->child_stdout_channel != NULL)
+    {
+      g_io_channel_unref (data->child_stdout_channel);
+      data->child_stdout_channel = NULL;
+    }
+  if (data->child_stderr_channel != NULL)
+    {
+      g_io_channel_unref (data->child_stderr_channel);
+      data->child_stderr_channel = NULL;
+    }
+
+  if (data->child_stdout_source != NULL)
+    {
+      g_source_destroy (data->child_stdout_source);
+      data->child_stdout_source = NULL;
+    }
+  if (data->child_stderr_source != NULL)
+    {
+      g_source_destroy (data->child_stderr_source);
+      data->child_stderr_source = NULL;
+    }
+
+  if (data->child_stdout_fd != -1)
+    {
+      g_warn_if_fail (close (data->child_stdout_fd) == 0);
+      data->child_stdout_fd = -1;
+    }
+  if (data->child_stderr_fd != -1)
+    {
+      g_warn_if_fail (close (data->child_stderr_fd) == 0);
+      data->child_stderr_fd = -1;
+    }
+
+  if (data->cancellable_handler_id > 0)
+    {
+      g_cancellable_disconnect (data->cancellable, data->cancellable_handler_id);
+      data->cancellable_handler_id = 0;
+    }
+
+  if (data->main_context != NULL)
+    g_main_context_unref (data->main_context);
+
+  if (data->cancellable != NULL)
+    g_object_unref (data->cancellable);
+
+  g_slice_free (UtilsSpawnData, data);
+}
+
+/* called in the thread where @cancellable was cancelled */
+static void
+utils_on_cancelled (GCancellable *cancellable,
+                    gpointer      user_data)
+{
+  UtilsSpawnData *data = user_data;
+  GError *error;
+
+  error = NULL;
+  g_warn_if_fail (g_cancellable_set_error_if_cancelled (cancellable, &error));
+  g_simple_async_result_take_error (data->simple, error);
+  g_simple_async_result_complete_in_idle (data->simple);
+  g_object_unref (data->simple);
+}
+
+static gboolean
+utils_read_child_stderr (GIOChannel *channel,
+                         GIOCondition condition,
+                         gpointer user_data)
+{
+  UtilsSpawnData *data = user_data;
+  gchar buf[1024];
+  gsize bytes_read;
+
+  g_io_channel_read_chars (channel, buf, sizeof buf, &bytes_read, NULL);
+  g_string_append_len (data->child_stderr, buf, bytes_read);
+  return TRUE;
+}
+
+static gboolean
+utils_read_child_stdout (GIOChannel *channel,
+                         GIOCondition condition,
+                         gpointer user_data)
+{
+  UtilsSpawnData *data = user_data;
+  gchar buf[1024];
+  gsize bytes_read;
+
+  g_io_channel_read_chars (channel, buf, sizeof buf, &bytes_read, NULL);
+  g_string_append_len (data->child_stdout, buf, bytes_read);
+  return TRUE;
+}
+
+static void
+utils_child_watch_cb (GPid     pid,
+                      gint     status,
+                      gpointer user_data)
+{
+  UtilsSpawnData *data = user_data;
+  gchar *buf;
+  gsize buf_size;
+
+  if (g_io_channel_read_to_end (data->child_stdout_channel, &buf, &buf_size, NULL) == G_IO_STATUS_NORMAL)
+    {
+      g_string_append_len (data->child_stdout, buf, buf_size);
+      g_free (buf);
+    }
+  if (g_io_channel_read_to_end (data->child_stderr_channel, &buf, &buf_size, NULL) == G_IO_STATUS_NORMAL)
+    {
+      g_string_append_len (data->child_stderr, buf, buf_size);
+      g_free (buf);
+    }
+
+  data->exit_status = status;
+
+  /* ok, child watch is history, make sure we don't free it in spawn_data_free() */
+  data->child_pid = 0;
+  data->child_watch_source = NULL;
+
+  /* we're done */
+  g_simple_async_result_complete_in_idle (data->simple);
+  g_object_unref (data->simple);
+}
+
+static gboolean
+utils_timeout_cb (gpointer user_data)
+{
+  UtilsSpawnData *data = user_data;
+
+  data->timed_out = TRUE;
+
+  /* ok, timeout is history, make sure we don't free it in spawn_data_free() */
+  data->timeout_source = NULL;
+
+  /* we're done */
+  g_simple_async_result_complete_in_idle (data->simple);
+  g_object_unref (data->simple);
+
+  return FALSE; /* remove source */
+}
+
+static void
+utils_spawn (const gchar *const  *argv,
+             guint                timeout_seconds,
+             GCancellable        *cancellable,
+             GAsyncReadyCallback  callback,
+             gpointer             user_data)
+{
+  UtilsSpawnData *data;
+  GError *error;
+
+  data = g_slice_new0 (UtilsSpawnData);
+  data->timeout_seconds = timeout_seconds;
+  data->simple = g_simple_async_result_new (NULL,
+                                            callback,
+                                            user_data,
+                                            utils_spawn);
+  data->main_context = g_main_context_get_thread_default ();
+  if (data->main_context != NULL)
+    g_main_context_ref (data->main_context);
+
+  data->cancellable = cancellable != NULL ? g_object_ref (cancellable) : NULL;
+
+  data->child_stdout = g_string_new (NULL);
+  data->child_stderr = g_string_new (NULL);
+  data->child_stdout_fd = -1;
+  data->child_stderr_fd = -1;
+
+  /* the life-cycle of UtilsSpawnData is tied to its GSimpleAsyncResult */
+  g_simple_async_result_set_op_res_gpointer (data->simple, data, (GDestroyNotify) utils_spawn_data_free);
+
+  error = NULL;
+  if (data->cancellable != NULL)
+    {
+      /* could already be cancelled */
+      error = NULL;
+      if (g_cancellable_set_error_if_cancelled (data->cancellable, &error))
+        {
+          g_simple_async_result_take_error (data->simple, error);
+          g_simple_async_result_complete_in_idle (data->simple);
+          g_object_unref (data->simple);
+          goto out;
+        }
+
+      data->cancellable_handler_id = g_cancellable_connect (data->cancellable,
+                                                            G_CALLBACK (utils_on_cancelled),
+                                                            data,
+                                                            NULL);
+    }
+
+  error = NULL;
+  if (!g_spawn_async_with_pipes (NULL, /* working directory */
+                                 (gchar **) argv,
+                                 NULL, /* envp */
+                                 G_SPAWN_SEARCH_PATH | G_SPAWN_DO_NOT_REAP_CHILD,
+                                 NULL, /* child_setup */
+                                 NULL, /* child_setup's user_data */
+                                 &(data->child_pid),
+                                 NULL, /* gint *stdin_fd */
+                                 &(data->child_stdout_fd),
+                                 &(data->child_stderr_fd),
+                                 &error))
+    {
+      g_prefix_error (&error, "Error spawning: ");
+      g_simple_async_result_take_error (data->simple, error);
+      g_simple_async_result_complete_in_idle (data->simple);
+      g_object_unref (data->simple);
+      goto out;
+    }
+
+  if (timeout_seconds > 0)
+    {
+      data->timeout_source = g_timeout_source_new_seconds (timeout_seconds);
+      g_source_set_priority (data->timeout_source, G_PRIORITY_DEFAULT);
+      g_source_set_callback (data->timeout_source, utils_timeout_cb, data, NULL);
+      g_source_attach (data->timeout_source, data->main_context);
+      g_source_unref (data->timeout_source);
+    }
+
+  data->child_watch_source = g_child_watch_source_new (data->child_pid);
+  g_source_set_callback (data->child_watch_source, (GSourceFunc) utils_child_watch_cb, data, NULL);
+  g_source_attach (data->child_watch_source, data->main_context);
+  g_source_unref (data->child_watch_source);
+
+  data->child_stdout_channel = g_io_channel_unix_new (data->child_stdout_fd);
+  g_io_channel_set_flags (data->child_stdout_channel, G_IO_FLAG_NONBLOCK, NULL);
+  data->child_stdout_source = g_io_create_watch (data->child_stdout_channel, G_IO_IN);
+  g_source_set_callback (data->child_stdout_source, (GSourceFunc) utils_read_child_stdout, data, NULL);
+  g_source_attach (data->child_stdout_source, data->main_context);
+  g_source_unref (data->child_stdout_source);
+
+  data->child_stderr_channel = g_io_channel_unix_new (data->child_stderr_fd);
+  g_io_channel_set_flags (data->child_stderr_channel, G_IO_FLAG_NONBLOCK, NULL);
+  data->child_stderr_source = g_io_create_watch (data->child_stderr_channel, G_IO_IN);
+  g_source_set_callback (data->child_stderr_source, (GSourceFunc) utils_read_child_stderr, data, NULL);
+  g_source_attach (data->child_stderr_source, data->main_context);
+  g_source_unref (data->child_stderr_source);
+
+ out:
+  ;
+}
+
+gboolean
+utils_spawn_finish (GAsyncResult   *res,
+                    gint           *out_exit_status,
+                    gchar         **out_standard_output,
+                    gchar         **out_standard_error,
+                    GError        **error)
+{
+  GSimpleAsyncResult *simple = G_SIMPLE_ASYNC_RESULT (res);
+  UtilsSpawnData *data;
+  gboolean ret = FALSE;
+
+  g_return_val_if_fail (G_IS_ASYNC_RESULT (res), FALSE);
+  g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
+
+  g_warn_if_fail (g_simple_async_result_get_source_tag (simple) == utils_spawn);
+
+  if (g_simple_async_result_propagate_error (simple, error))
+    goto out;
+
+  data = g_simple_async_result_get_op_res_gpointer (simple);
+
+  if (data->timed_out)
+    {
+      g_set_error (error,
+                   G_IO_ERROR,
+                   G_IO_ERROR_TIMED_OUT,
+                   "Timed out after %d seconds",
+                   data->timeout_seconds);
+      goto out;
+    }
+
+  if (out_exit_status != NULL)
+    *out_exit_status = data->exit_status;
+
+  if (out_standard_output != NULL)
+    *out_standard_output = g_strdup (data->child_stdout->str);
+
+  if (out_standard_error != NULL)
+    *out_standard_error = g_strdup (data->child_stderr->str);
+
+  ret = TRUE;
+
+ out:
+  return ret;
+}