static void check_authorization_cb(PolkitAuthority *authority,
                                   GAsyncResult *res, gpointer data)
{
    PolkitAuthorizationResult *result;
    GError *err = NULL;
    struct stat stat_buf;

    g_clear_object(&polkit_cancellable);

    result = polkit_authority_check_authorization_finish(authority, res, &err);
    if (err) {
        FATAL_ERROR("PoliciKit error: %s\n", err->message);
        g_error_free(err);
        return;
    }

    if (polkit_authorization_result_get_dismissed(result)) {
        ERROR("CANCELED\n");
        return;
    }

    if (!polkit_authorization_result_get_is_authorized(result)) {
        ERROR("Not authorized\n");
        return;
    }

    snprintf(path, PATH_MAX, "/dev/bus/usb/%03d/%03d", busnum, devnum);

    if (stat(path, &stat_buf) != 0) {
        FATAL_ERROR("statting %s: %s\n", path, strerror(errno));
        return;
    }
    if (!S_ISCHR(stat_buf.st_mode)) {
        FATAL_ERROR("%s is not a character device\n", path);
        return;
    }

    if (set_facl(path, getuid(), 1)) {
        FATAL_ERROR("setting facl: %s\n", strerror(errno));
        return;
    }

    fprintf(stdout, "SUCCESS\n");
    fflush(stdout);
    state = STATE_WAITING_FOR_STDIN_EOF;
}

authority = polkit_authority_get_sync(NULL, NULL);
pid_t parent_pid;
parent_pid = getppid ();
subject = polkit_unix_process_new_for_owner(parent_pid, 0, getuid ());

polkit_authority_check_authorization(authority, subject, "org.spice-space.lowlevelusbaccess", NULL,
    POLKIT_CHECK_AUTHORIZATION_FLAGS_ALLOW_USER_INTERACTION,
    polkit_cancellable,
    (GAsyncReadyCallback)check_authorization_cb, NULL);
state = STATE_WAITING_FOR_POL_KIT;