HttpFilterProc
A version of this page is also available for
4/8/2010
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 (SF_NOTIFY_READ_RAW_DATA and SF_NOTIFY_SEND_RAW_DATA notification types) is deprecated. 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_READ_RAW_DATA
SF_NOTIFY_SEND_RAW_DATA
HTTP_FILTER_RAW_DATA
SF_NOTIFY_PREPROC_HEADERS
SF_NOTIFY_AUTHENTICATION
SF_NOTIFY_URL_MAP
SF_NOTIFY_LOG
SF_NOTIFY_ACCESS_DENIED
SF_NOTIFY_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 |
| Windows Embedded CE | Windows CE 3.0 and later |
| Windows Mobile | Pocket PC 2000 and later, Smartphone 2002 and later |