HTTP_FILTER_PREPROC_HEADERS

The ISA Server Web proxy includes a pointer to the HTTP_FILTER_PREPROC_HEADERS structure in the notification that it sends to Web filters when it preprocesses a request's headers. If your filter should be notified for this event, it must register to receive SF_NOTIFY_PREPROC_HEADERS notifications. For more information about the types of event notifications that are sent to Web filters, see Event Notifications.

Note  When you are creating a Web filter for ISA Server, we recommend that you use WPX_FILTER_PREPROC_HEADERS rather than HTTP_FILTER_PREPROC_HEADERS.

typedef struct _HTTP_FILTER_PREPROC_HEADERS {

  BOOL (WINAPI)* GetHeader;

  BOOL (WINAPI)* SetHeader;

  BOOL (WINAPI)* AddHeader;

  DWORD HttpStatus;

  DWORD dwReserved;
} HTTP_FILTER_PREPROC_HEADERS, 

*PHTTP_FILTER_PREPROC_HEADERS;

Members

GetHeader

Pointer to the GetHeader callback function, which can be used to retrieve a specified header or a portion of the request line in the incoming request. Header names include a trailing colon (:). Individual portions of the request line are specified by the special values "body" (for requests only), "method", "URL", and "version". The status from the response line is specified by the special value "status". The special values are case-sensitive and must not include the trailing colon.

SetHeader

Pointer to the SetHeader callback function, which can be used to modify or delete the value of a header or to modify a portion included in the request line or response line specified by a special value.

AddHeader

Pointer to the AddHeader callback function, which can be used to add an HTTP header to the request.

HttpStatus

Not used.

dwReserved

A DWORD reserved for later use.

Remarks

When the Web proxy is about to process the client headers, it sends a notification by calling the HttpFilterProc entry-point function of each Web filter that is registered to receive the notification. The pvNotification parameter contains a pointer to an HTTP_FILTER_PREPROC_HEADERS structure, and the notificationType parameter is set to SF_NOTIFY_PREPROC_HEADERS.

Requirements

Server: Requires Windows Server 2003 or Windows 2000.
Version: Requires Internet Security and Acceleration Server 2004.
Header: Declared in Wpxhttpfilt.h.

See Also

Notification Structures