Professional ASP.NET 3.5 Security, Membership, and Role Management with C# and VB

2.2. IIS 7.0 Integrated Mode Architecture

The initial processing of an HTTP request on IIS 7.0 running in the Classic mode, resembling the same IIS 6.0 functionality, occurs within both IIS and a supporting protocol driver. As a result, depending on the configuration for IIS, a request may never make it far enough to be processed by ASP.NET. Figure 2-1 shows the salient portions of IIS 7.0 running in the Classic mode and Windows Server 2008 or Windows Vista/2003 that participate in request processing.

Figure 2-1. Figure 2-1

A request must first pass the restrictions enforced by the kernel mode HTTP driver: http.sys. The request is handed off to a worker process, where it then flows through a combination of the internal request processing provided by IIS and several ISAPI filters and extensions. Ultimately, the request is routed to the appropriate content handler, which for ASP.NET pages is the ASP.NET runtime's ISAPI extension.

The ASP.NET ISAPI extension contains the ASP.NET runtime request-processing pipeline. It can be easily concluded how the request first passes through the IIS request-processing pipeline for authentication, authorization, and all other modules. When it is time to determine the handler for the request based on the request's file extension, in case of an ASP.NET page, IIS passes the request to the ASP.NET ISAPI extension. Once the extension is activated, ...