Microsoft Internet Security and Acceleration Server 2004 SDK

Web Filter Structures

The Web proxy of ISA Server works with the structures described here.

HTTP_FILTER_CONTEXT

The HTTP_FILTER_CONTEXT structure is used by HttpFilterProc to obtain information about the current request. The structure includes pointers to the following functions:

HTTP_FILTER_VERSION

The HTTP_FILTER_VERSION structure is used by the GetFilterVersion and the GetWPXFilterVersion functions to obtain the filter's version information and registered notifications.

WPX_FILTER_CONTEXT

The WPX_FILTER_CONTEXT structure provides additional information and functions for the current request. The structure extends HTTP_FILTER_CONTEXT and adds the following functions:

Note  To use these functions you must get a pointer to the WPX_FILTER_CONTEXT structure from a pointer to an HTTP_FILTER_CONTEXT structure. To do so, use the TO_WPX_FILTER_CONTEXT macro as follows:

WPX_FILTER_CONTEXT* pwfc = TO_WPX_FILTER_CONTEXT(pfc);
if (pwfc != NULL) {
...
}