Editing Handlers

Handlers are the program routines of the decider. They check the requests by using the rules stored in the active ruleset.

Definition levels and Inheritance

You can add handlers to different hierarchy levels:

  • For an application:

    In this case, you can either add a global handler or a handler template that’s inherited by all paths in that application (see Types of Handlers and Attribute Inheritance for details).

  • For an application’s path:

    In this case, the handler isn’t inherited any further and only applies to that one path.

Adding handlers

  1. In the navigation area, select the application to which you want to add the handler.
  2. If you want to add the handler on application level, activate the Ruleset Config | Global Handlers tab or the Ruleset Config | Handler Templates tab.
    If you want to add the handler on path level, activate the Ruleset Config | Path tab, and then in the Action column click the Edit symbol of the path to which you want to add the handler.

  3. From the selection list under Add Handler, select the handler to be added. This selection list only contains the handlers that have not yet been added and that apply to the handler type you’re adding (global handler or handler template). Details on the individual handlers can be found in the reference part under Handlers.
  4. Click the Add button.
    The handler appears with color emphasis on the list. The position on the list is determined by the sequence in which vWAF executes the handlers. This sequence is preset and can’t be changed.

The handler initially inherits the attributes preset on the system. This is shown in the Inherited Attrs column (inherited attributes).

To configure the handler in detail, you need to edit it.

The handler isn’t active when you’ve added it. To achieve this, you need to commit and activate the configuration (see Committing and Activating Ruleset Changes).

Editing a handler

ATTENTION
When editing a handler template, you also change the settings of all the relevant handlers of the paths defined for that application. This is a result of the built-in inheritance mechanism. However, this doesn’t apply when an attribute has been overwritten on the level of a path (see Types of Handlers and Attribute Inheritance).

Not all handlers have configurable attributes. In some cases, this means that the Edit function isn’t available.

  1. In the navigation area, select the application to which the handler that you want to edit has been assigned.
  2. If you want to edit a handler that has been assigned on application level, activate the Ruleset Config | Global Handlers tab or the Ruleset Config | Handler Templates tab. If you want to edit a handler that has been assigned on path level, activate the Ruleset Config | Path tab, and then, in the Path column, click the path to which the handler has been assigned.
  3. In the Action column, click the relevant Edit icon.

    Now the display of the attributes of the handler is shown.

    • In the Inheritance column you can see whether the values given under Value have been inherited (entry Inherited) or overwritten (entry Local). If an entry has been overwritten, an additional check box labeled reset values appears. If you activate this check box, vWAF resets the value of the attribute back to its inherited value when you click Save. (This even applies if you’ve also changed the value in the Value column.)
    • The Owner column shows the username of the administrator who made that setting. The BUILT-IN entry identifies the default values.
    • The Last Commit column shows whether and when a setting has already been committed.

    For detailed information on the attributes of the individual handlers, see Handlers.

  4. Make the required settings, and then click the Save button.

Removing a handler

ATTENTION
When you remove a handler template on application level, you also remove all the corresponding inherited handlers of the individual paths defined for the application. This also applies if you’ve overwritten individual attributes of that handler.

  1. In the navigation area, select the application to which the handler that you want to remove has been assigned.
  2. If you want to remove a handler that has been assigned on application level, activate the Ruleset Config | Global Handlers tab or the Ruleset Config | Handler Templates tab. If you want to remove a handler that has been assigned on path level, activate the Ruleset Config | Path tab, and then, in the Path column, click the path to which the handler has been assigned.
  3. In the Action column, click the relevant Delete icon.