check_property_access: centralize error handling (and check for OOM)

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=35766
Reviewed-by: Cosimo Alfarano <cosimo.alfarano@collabora.co.uk>

1 files changed, 43 insertions, 26 deletions

diff --git a/dbus/dbus-gobject.c b/dbus/dbus-gobject.c
index ef6e981..e416bda 100644
--- a/dbus/dbus-gobject.c
+++ b/dbus/dbus-gobject.c
@@ -1959,6 +1959,20 @@ done:
   return result;
 }
 
+/*
+ * @wincaps_propiface: the D-Bus interface name, conventionally WindowsCaps
+ * @requested_propname: the D-Bus property name, conventionally WindowsCaps
+ * @uscore_propname: the GObject property name, conventionally
+ *    words_with_underscores or words-with-dashes
+ * @is_set: %TRUE if we're going to set the property, %FALSE if we're going
+ *    to get it
+ *
+ * Check that the requested property exists and the requested access is
+ * allowed. If not, reply with a D-Bus AccessDenied error message.
+ *
+ * Returns: %TRUE if property access can continue, or FALSE if an error
+ *    reply has been sent
+ */
 static gboolean
 check_property_access (DBusConnection  *connection,
                        DBusMessage     *message,
@@ -1971,6 +1985,7 @@ check_property_access (DBusConnection  *connection,
   const DBusGObjectInfo *object_info;
   const char *access_type;
   DBusMessage *ret;
+  gchar *error_message;
 
   if (!is_set && !disable_legacy_property_access)
     return TRUE;
@@ -1978,14 +1993,11 @@ check_property_access (DBusConnection  *connection,
   object_info = lookup_object_info_by_iface (object, wincaps_propiface, TRUE, NULL);
   if (!object_info)
     {
-      ret = dbus_message_new_error_printf (message,
-                                           DBUS_ERROR_ACCESS_DENIED,
-                                           "Interface \"%s\" isn't exported (or may not exist), can't access property \"%s\"",
-                                           wincaps_propiface,
-                                           requested_propname);
-      dbus_connection_send (connection, ret, NULL);
-      dbus_message_unref (ret);
-      return FALSE;
+      error_message = g_strdup_printf (
+          "Interface \"%s\" isn't exported (or may not exist), can't access property \"%s\"",
+          wincaps_propiface, requested_propname);
+
+      goto error;
     }
 
   /* Try both forms of property names: "foo_bar" or "FooBar"; for historical
@@ -1995,32 +2007,37 @@ check_property_access (DBusConnection  *connection,
       && !(property_info_from_object_info (object_info, wincaps_propiface, requested_propname, &access_type)
            || property_info_from_object_info (object_info, wincaps_propiface, uscore_propname, &access_type)))
     {
-      ret = dbus_message_new_error_printf (message,
-                                           DBUS_ERROR_ACCESS_DENIED,
-                                           "Property \"%s\" of interface \"%s\" isn't exported (or may not exist)",
-                                           requested_propname,
-                                           wincaps_propiface);
-      dbus_connection_send (connection, ret, NULL);
-      dbus_message_unref (ret);
-      return FALSE;
+      error_message = g_strdup_printf (
+          "Property \"%s\" of interface \"%s\" isn't exported (or may not exist)",
+          requested_propname, wincaps_propiface);
+
+      goto error;
     }
 
   if (strcmp (access_type, "readwrite") == 0)
     return TRUE;
-  else if (is_set ? strcmp (access_type, "read") == 0
+
+  if (is_set ? strcmp (access_type, "read") == 0
              : strcmp (access_type, "write") == 0)
     {
-       ret = dbus_message_new_error_printf (message,
-                                           DBUS_ERROR_ACCESS_DENIED,
-                                           "Property \"%s\" of interface \"%s\" is not %s",
-                                           requested_propname,
-                                           wincaps_propiface,
-                                           is_set ? "settable" : "readable");
-      dbus_connection_send (connection, ret, NULL);
-      dbus_message_unref (ret);
-      return FALSE;
+      error_message = g_strdup_printf (
+          "Property \"%s\" of interface \"%s\" is not %s",
+          requested_propname,
+          wincaps_propiface,
+          is_set ? "settable" : "readable");
+
+      goto error;
     }
+
   return TRUE;
+
+error:
+  ret = error_or_die (message, DBUS_ERROR_ACCESS_DENIED, error_message);
+  g_free (error_message);
+
+  dbus_connection_send (connection, ret, NULL);
+  dbus_message_unref (ret);
+  return FALSE;
 }
 
 static DBusHandlerResult