Platform SDK: Internet Security and Acceleration Server 2000
Event Notifications
The following is an alphabetic table of notifications for which a Web (ISAPI) filter can be registered. For more information about event notifications, see Introduction to Web Filters.
| Notification Constant | Meaning |
| SF_NOTIFY_ACCESS_DENIED | Occurs just after IIS or ISA has determined that access is denied for the request resource, but before IIS or ISA has sent a response to the client. |
| SF_NOTIFY_AUTH_COMPLETE | In HTTP authentication scenario, this notification occurs just after IIS or ISA has determined that access is allowed for the request resource. |
| SF_NOTIFY_AUTHENTICATION | Occurs just before IIS or ISA authenticates the client. |
| SF_NOTIFY_END_OF_NET_SESSION | Occurs when a network session with a client is ending. |
| SF_NOTIFY_END_OF_REQUEST | Occurs at the end of a request. |
| SF_NOTIFY_LOG | Occurs at the end of a request, just before ISA writes the transaction to the ISA log. |
| SF_NOTIFY_PREPROC_HEADERS | Occurs immediately after IIS or ISA has preprocessed headers, but before the program begins to process header content. |
| SF_NOTIFY_READ_RAW_DATA | Occurs when data is being read from the client. May occur more than once per request. |
| SF_NOTIFY_SEND_RAW_DATA | Occurs as IIS or ISA sends raw data back to the client. May occur more than once per request. |
| SF_NOTIFY_SEND_RESPONSE | Occurs after the request has been processed by IIS, but before any headers are sent back to the client. This notification is not used when the Web proxy service sends a response. However, it is called when a filter generates a response itself by using ServerSupportFunction (SF_REQ_SEND_RESPONSE_HEADERS). |
| SF_NOTIFY_URL_MAP | Occurs after IIS has translated a URL to a physical path on the server. This notification is irrelevant for the ISA Web proxy service because it does not have any physical URLs. However, it is provided as it was in Microsoft Proxy Server 2.0, for compatibility with earlier versions. |
In addition to the notification events, ISAPI makes use of flags relating to filter priority and port security settings.
Filter Priority Settings
| Value | Meaning |
| SF_NOTIFY_ORDER_DEFAULT | Default priority (medium priority). |
| SF_NOTIFY_ORDER_LOW | Low priority. |
| SF_NOTIFY_ORDER_MEDIUM | Medium priority. |
| SF_NOTIFY_ORDER_HIGH | High priority. |
Port Security Settings
| Value | Meaning |
| SF_NOTIFY_SECURE_PORT | Notify the application only for connections over a secure port. |
| SF_NOTIFY_NONSECURE_PORT | Notify the application only for connections over a nonsecure port. |