HttpFilterProc (Compact 2013)

3/26/2014

This function is an application-defined function. The Web Server calls it when a notification event for which the filter has registered (in GetFilterVersion) occurs. ISAPI filters export this function so the Web Server service can pass information and control to the filters.

Note

Registering ISAPI filters for raw data notifications is no longer supported. Applications should write ISAPI extensions to process and generate data that is sent to and from the Web Server.

Syntax

DWORD WINAPI HttpFilterProc(
  PHTTP_FILTER_CONTEXT pfc, 
  DWORD NotificationType, 
  VOID* pvNotification
);

Parameters

• pfc
  [in] Pointer to an HTTP_FILTER_CONTEXT structure that is associated with the current, active HTTP transaction.

• NotificationType
  [in] Pointer to a bitmask that indicates the type of notification event that is being processed.

• pvNotification
  [in] Pointer to a notification-specific structure that contains additional information about the current context of the request. The following table shows the possible notification types and the corresponding structures.

  Notification type	Structure
  SF_NOTIFY_PREPROC_HEADERS	HTTP_FILTER_PREPROC_HEADERS
  SF_NOTIFY_AUTHENTICATION	HTTP_FILTER_AUTHENT
  SF_NOTIFY_URL_MAP	HTTP_FILTER_URL_MAP
  SF_NOTIFY_LOG	HTTP_FILTER_LOG
  SF_NOTIFY_ACCESS_DENIED	HTTP_FILTER_ACCESS_DENIED
  SF_NOTIFY_SEND_RESPONSE	HTTP_FILTER_SEND_RESPONSE

Return Value

Returns a DWORD status code that indicates how the application handled the event. The following table shows the possible return values.

Return value	Description
SF_STATUS_REQ_FINISHED	The filter has handled the HTTP request. The server should disconnect the session.
SF_STATUS_REQ_FINISHED_KEEP_CONN	Treated the same as SF_STATUS_REQ_FINISHED. After this notification is received, the connection is closed.
SF_STATUS_REQ_NEXT_NOTIFICATION	The next filter in the notification chain should be called.
SF_STATUS_REQ_HANDLED_NOTIFICATION	This filter handled the notification. No other handlers should be called for this particular notification type.
SF_STATUS_REQ_ERROR	An error occurred. The server should call GetLastError and indicate the error to the client. The HTTP request will generally be aborted when this status is returned. The client should call SetLastError with the nature of the failure.

Remarks

This function usually serves as the dispatch for a Web (ISAPI) filter. Separate functions are often created to serve as handlers for the separate notifications, especially if the handling code is complicated.

Requirements

Header	httpfilt.h
Library	Developer Implemented

See Also

Reference

Web Server Functions
GetFilterVersion

Other Resources

SetLastError