ISAPI Filter Callback Functions

This section describes how ISAPI filters use callback functions to communicate with IIS. When IIS calls the HttpFilterProc entry-point function of an ISAPI filter, it receives a pointer to an HTTP_FILTER_CONTEXT structure, which specifies, among other things, a callback function. Callback functions can also be specified from the HTTP_FILTER_PREPROC_HEADERS structure.

This section includes the following topics:

• AddHeader Function

• AddResponseHeaders Function

• AllocMem Function

• GetHeader Function

• GetServerVariable Function

• GetUserToken Function

• ServerSupportFunction

• SetHeader

• WriteClient