|Microsoft Internet Security and Acceleration Server 2004 SDK|
The ISA Server Web proxy calls entry-point functions in a Web filter to pass initialization information to the Web filter, to notify the Web filter that a certain event has occurred, and to inform the Web filter that it is about to be unloaded from memory. Web filters can implement the following entry-point functions that were also available for ISAPI Web filters in ISA Server 2000:
Web filters can also implement the following entry-point functions that are specific to ISA Server 2004:
Note At a minimum, a Web filter must implement either GetFilterVersion and HttpFilterProc, or GetWPXFilterVersion and HttpWPXFilterProc (or both pairs of functions).
In addition, a Web filter can implement the following optional entry-point functions:
Web Filter Reference