[Spice-devel] [vdagent-linux v1] systemd-login: check for LockedHint property

[Pavel Grunt]

Hi,

On Fri, 2016-05-27 at 11:42 +0200, Victor Toso wrote:
> Property introduced in v230 of systemd.
> 
> Systems that don't have up to date systemd-login will get the
> following log message:
> 
> "Properties.Get failed: Unknown property or interface."
Can we give more info (which property is unknown) ? To make it easier for users.
The property is new, so almost everyone will see the message in the log.
> 
> Resolves: rhbz#1323623
> ---
>  src/systemd-login.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++++---
> -
>  1 file changed, 95 insertions(+), 7 deletions(-)
> 
> diff --git a/src/systemd-login.c b/src/systemd-login.c
> index 730547a..c56fca4 100644
> --- a/src/systemd-login.c
> +++ b/src/systemd-login.c
> @@ -36,14 +36,21 @@ struct session_info {
>          char *match_session_signals;
>      } dbus;
>      gboolean session_is_locked;
> +    gboolean session_locked_hint;
>  };
>  
> +#define LOGIND_INTERFACE            "org.freedesktop.login1"
> +
>  #define LOGIND_SESSION_INTERFACE    "org.freedesktop.login1.Session"
>  #define LOGIND_SESSION_OBJ_TEMPLATE "/org/freedesktop/login1/session/_3%s"
>  
> +#define DBUS_PROPERTIES_INTERFACE   "org.freedesktop.DBus.Properties"
> +
>  #define SESSION_SIGNAL_LOCK         "Lock"
>  #define SESSION_SIGNAL_UNLOCK       "Unlock"
>  
> +#define SESSION_PROP_LOCKED_HINT    "LockedHint"
> +
>  /* dbus related */
>  static DBusConnection *si_dbus_get_system_bus(void)
>  {
> @@ -112,6 +119,84 @@ static void si_dbus_match_rule_update(struct session_info
> *si)
>  }
>  
>  static void
> +si_dbus_read_properties(struct session_info *si)
> +{
> +    dbus_bool_t locked_hint, ret;
> +    DBusMessageIter iter, iter_variant;
> +    gint type;
> +    DBusError error;
> +    DBusMessage *message = NULL;
> +    DBusMessage *reply = NULL;
> +    gchar *session_object;
> +    const gchar *interface, *property;
> +
> +    if (si->session == NULL)
> +        return;
> +
> +    session_object = g_strdup_printf(LOGIND_SESSION_OBJ_TEMPLATE, si-
> >session);
> +    message = dbus_message_new_method_call(LOGIND_INTERFACE,
> +                                           session_object,
> +                                           DBUS_PROPERTIES_INTERFACE,
> +                                           "Get");
> +    g_free (session_object);
> +    if (message == NULL) {
> +        syslog(LOG_ERR, "Unable to create dbus message");
> +        goto exit;
> +    }
> +
> +    interface = LOGIND_SESSION_INTERFACE;
> +    property = SESSION_PROP_LOCKED_HINT;
> +    ret = dbus_message_append_args(message,
> +                                   DBUS_TYPE_STRING, &interface,
> +                                   DBUS_TYPE_STRING, &property,
> +                                   DBUS_TYPE_INVALID);
> +    if (!ret) {
> +        syslog(LOG_ERR, "Unable to request locked-hint");
> +        goto exit;
> +    }
> +
> +    dbus_error_init(&error);
> +    reply = dbus_connection_send_with_reply_and_block(si-
> >dbus.system_connection,
> +                                                      message,
> +                                                      -1,
> +                                                      &error);
> +    if (reply == NULL || dbus_error_is_set(&error)) {
According to function definition error is set on failure, so this block can be
simplified
> +        if (dbus_error_is_set(&error)) {
> +            syslog(LOG_ERR, "Properties.Get failed: %s", error.message);
> +            dbus_error_free(&error);
> +        } else {
> +            syslog(LOG_ERR, "Properties.Get failed");
> +        }
> +        goto exit;
> +    }
> +
> +    dbus_message_iter_init(reply, &iter);
> +    type = dbus_message_iter_get_arg_type(&iter);
> +    if (type != DBUS_TYPE_VARIANT) {
> +        syslog(LOG_ERR, "expected a variant, got a '%c' instead", type);
> +        goto exit;
> +    }
> +
> +    dbus_message_iter_recurse(&iter, &iter_variant);
> +    type = dbus_message_iter_get_arg_type(&iter_variant);
> +    if (type != DBUS_TYPE_BOOLEAN) {
> +        syslog(LOG_ERR, "expected a boolean, got a '%c' instead", type);
> +        goto exit;
> +    }
> +    dbus_message_iter_get_basic(&iter_variant, &locked_hint);
> +
> +    si->session_locked_hint = (locked_hint) ? TRUE : FALSE;
> +exit:
> +    if (reply != NULL) {
> +        dbus_message_unref(reply);
> +    }
> +
> +    if (message != NULL) {
> +        dbus_message_unref(message);
> +    }
> +}
> +
> +static void
>  si_dbus_read_signals(struct session_info *si)
>  {
>      DBusMessage *message = NULL;
> @@ -220,16 +305,19 @@ char *session_info_session_for_pid(struct session_info
> *si, uint32_t pid)
>  
>  gboolean session_info_session_is_locked(struct session_info *si)
>  {
> -    g_return_val_if_fail (si != NULL, FALSE);
> +    gboolean locked;
>  
> -    /* We could also rely on IdleHint property from Session which seems to
> work
> -     * well in rhel7 but it wasn't working well in my own system (F23). I'm
> -     * convinced for now that Lock/Unlock signals should be enough but that
> -     * means Lock/Unlock being done by logind. That might take a while.
> -     * Check: https://bugzilla.gnome.org/show_bug.cgi?id=764773 */
> +    g_return_val_if_fail (si != NULL, FALSE);
>  
>      si_dbus_read_signals(si);
> -    return si->session_is_locked;
> +    si_dbus_read_properties(si);
> +
> +    locked = (si->session_is_locked || si->session_locked_hint);
> +    if (si->verbose) {
> +        syslog(LOG_DEBUG, "(systemd-login) session is locked: %s",
> +               locked ? "yes" : "no");
> +    }
> +    return locked;
>  }
>  
>  /* This function should only be called after session_info_get_active_session

Looks good.

Thanks,
Pavel