<modules runAllManagedModulesForAllRequests="true" /> Meaning - asp.net

I wanted to know what is the meaning of
<modules runAllManagedModulesForAllRequests="true" />
I am using IIS 7.5 and I have a simple web application. Do I need to write this in my web.config file.
I have also written few http handler for jquery ajax call.
I am using form authentication and asp.net 4.0.
How can I determine which module I have to run and which is not to be?

Modules Preconditions:
The IIS core engine uses preconditions to determine when to enable a particular module. Performance reasons, for example, might determine that you only want to execute managed modules for requests that also go to a managed handler. The precondition in the following example (precondition="managedHandler") only enables the forms authentication module for requests that are also handled by a managed handler, such as requests to .aspx or .asmx files:
<add name="FormsAuthentication" type="System.Web.Security.FormsAuthenticationModule" preCondition="managedHandler" />
If you remove the attribute precondition="managedHandler", Forms Authentication also applies to content that is not served by managed handlers, such as .html, .jpg, .doc, but also for classic ASP (.asp) or PHP (.php) extensions. See "How to Take Advantage of IIS Integrated Pipeline" for an example of enabling ASP.NET modules to run for all content.
You can also use a shortcut to enable all managed (ASP.NET) modules to run for all requests in your application, regardless of the "managedHandler" precondition.
To enable all managed modules to run for all requests without configuring each module entry to remove the "managedHandler" precondition, use the runAllManagedModulesForAllRequests property in the <modules> section:
<modules runAllManagedModulesForAllRequests="true" />
When you use this property, the "managedHandler" precondition has no effect and all managed modules run for all requests.
Copied from IIS Modules Overview: Preconditions

Related

Can't stop firing ASP.NET Module for static content

I have a module in an ASP.NET MVC application. The module is working fine, but it's firing for every type of file including static content even though I have:
<modules runAllManagedModulesForAllRequests="false">
<add name="MyModule" ... / >
</modules>
The module hooks AcquireRequestState and PostRequestHandlerExecute events and both show static content firing (.htm, .css, .png etc.).
I was under the impression that runAllManagedModulesForAllRequests="false" should keep modules from firing on non-ASP.NET content.
To clarify:
I can set preCondition="managedHandler" like this:
<add name="MyModule" type="MyApp.MyModule" preCondition="managedHandler" />
and get my module to fire only managed requests.
However, I'm trying to understand why the IIS pipeline in general is firing managed module hits for every request. I think this used to work just fine in older versions where unless runAllManagedModulesForAllRequests="true" it wasn't firing unmanaged content into ASP.NET modules.
Running on IIS8 on Windows 8 64 bit mode, with integrated pipeline mode.
Update:
After some more research it turns out that the following is true:
if runAllManagedModulesForAllRequests="true" all modules - regardless of their preCondition attribute setting fire on all requests. This also true for Application_XXXX events implement on the HttpApplication
runAllManagedModulesForAllRequests="false" has no effect of keeping unmanaged requests from hitting modules, unless preCondition="managedHandler" is set
runAllManagedModulesForAllRequests="false" does affect Application_XXXX events, causing those events to only fire on managed requests then. IOW, Application_XXXX behaves as if the 'module' implementation had a preCondition="managedHandler"
For more detailed information on this I posted a blog entry:
http://www.west-wind.com/weblog/posts/2012/Oct/25/Caveats-with-the-runAllManagedModulesForAllRequests-in-IIS-78
In IIS7 Microsoft introduced a new way of developing modules and handlers by using managed (.NET) code, not just native code. Problem is switching a request between managed and native code is very expensive, so Microsoft introduced the preCondition="managedHandler". It flags the module as only available for managed content requests (.aspx, .asmx, ...) so IIS avoids firing it for static content.
Now, you can have a situation where you want to modify an static content request, such as minifying JavaScript on the fly. You can write the module using C# and compile it as a managed module, but you want it to be fired for static content, so you simply do not mark it as managedHandler.
Finally, runAllManagedModulesForAllRequests="true" is used to override preCondition="managedHandler" so all of them get fired.
There is more info available at:
http://www.iis.net/learn/get-started/introduction-to-iis/iis-modules-overview#Precondition

Servicing HTTP PUT from .ashx handler in ASP.NET without tweaking file permissions

I've got an .ASHX handler I want to use to process an HTTP PUT to allow me to upload files to the web server--the .ASHX file actually uploaded data and sticks the file elsewhere, so it never actually touches the disk here.
I've set the web.config to allow it to handle HTTP PUT, but IIS won't pass the request to my code unless I set the ACLs on the .ASHX files themselves to be writable--Which is kinda silly, since we're not actually going to write to those files.
If I set the ACLs, it works fine, but I'd like to be able to process the file without having to set the ACLs at all (I'm sure there's an appropriate way to make IIS just pass the HTTP PUT to the .ASHX file without checking the permissions on the file itself.
This is on Win2008 R2 (actually, it's on Azure's 2008 R2, but should be the same), using .NET 4.0
401 - Unauthorized: Access is denied due to invalid credentials.
You do not have permission to view this directory or page using the credentials that you supplied.
There are several roadblocks to getting PUT (and DELETE) working with ASP.NET. Since you mention Win2008 R2 (IIS 7.5) I would check to see if the errors you are seeing mention the WebDAV module or handler.
WebDAV is enabled by default as of IIS 7.5. It will interfere with HTTP PUT and DELETE verbs on ASP.NET handlers and modules. If you're implementing a RESTful service you likely don't even utilize this functionality. Disable it via your web.config.
<system.webServer>
<modules>
<remove name="WebDAVModule" />
</modules>
<handlers>
<remove name="WebDAV" />
</handlers>
</system.webServer>
Some other solutions are mentioned in this forum post entitled HTTP Error 405 With ASP.Net MVC and HTTP PUT on IIS 7.5.

Bypass existing HttpModule for a http handler

Scenario:
I have a bunch of web applications for which I want to add a simple ping functionality via http handler. Example: Http://myserver/foo/testfolder/ping.me
Problem:
For some of the applications this approach does not work becasue of custom HttpModule. These modules have some depedency on either authentication or some other processing logic due to which it makes the request invalid.
I am trying to find a solution to get this ping functionality work without making any changes to existing HttpModules.
HttpModules are associated with the application instance and applies to all sub folders.
Hence you cannot bypass it.
Assuming you're wanting to disable HttpModules for only the URL to the ping handler, you can do this in your web.config:
<location path="/url/to/ping/handler">
<system.web>
<httpModules>
<remove name="moduleToRemove1"/>
<remove name="moduleToRemove2"/>
</httpModules>
</system.web>
</location>
This will disable the modules for the given url only.

Understanding the ASP.NET application folders

The application folders in ASP.NET are used for storing various elements critical to running a website. I want to get a handle on understanding these folders in more depth, specifically the folder accessibility. According to the article on ASP.NET Web Site Layout:
The content of application folders,
except for the App_Themes folder, is
not served in response to Web
requests, but it can be accessed from
application code.
Any browser request to these folders results in a "404 - Page Not Found."
So what prevents folders like App_Code, App_Data, App_WebReferences, bin, etc. from being served to users? Is it an IIS hard coded "don't serve this folder?" Is it a permissions configuration? And is there anyway to knowingly/unknowingly circumvent this?
On my IIS7.5 config, found at C:\Windows\System32\inetsrv\config\applicationHost.config there is this section:
<hiddenSegments applyToWebDAV="true">
<add segment="web.config" />
<add segment="bin" />
<add segment="App_code" />
<add segment="App_GlobalResources" />
<add segment="App_LocalResources" />
<add segment="App_WebReferences" />
<add segment="App_Data" />
<add segment="App_Browsers" />
</hiddenSegments>
See also IIS Documentation.
In IIS7 on Windows Server 2008, ASP.NET is more tightly integrated into the entire processing pipeline, so I would imagine that in IIS7, it is very easy for ASP.NET to say "No, I'm not going to touch that."
In IIS6, IIS itself has very little direct knowledge of IIS, instead, it's all controlled through the ISAPI configuration.
In the IIS6 IIS Manager, right click a website, get Properties, go to the Home Directory tab, and then click Configuration in the lower right. This shows the ISAPI application extensions and what is done for each one.
For all the ASP.NET extensions (aspx, ascx, config, browser, a ton of others) it specifies handling to be done by C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll
The ASP.NET system then has registered handlers for each of these file types defined in the global machine.config and/or web.config files at C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\CONFIG
For instance, in the global web.config file, under httpHandlers element:
<add path="*.ascx" verb="*" type="System.Web.HttpForbiddenHandler" validate="true"/>
So it is not just these special folders, but many types of files, but many types of reserved files that are disallowed from browsing.
The .net framework itself intercepts requests to these folders (along with a bunch of other file types that you should be allowed to browse) and returns a 404 to IIS, which then gets passed back to the browser as "404 - Page Not Found".
So it doesn't happen at the permissions level, or even the IIS level. It's inside the framework -- probably in one of the HttpHandlers in the global web.config.
If you look in there, you can see a ton of file extensions that are explicitly configured to not be served. Presumably you could tweak the settings and cause it to serve, say, web.config files as xml (which is different than the usual behavior of saying that this file type is not served).
It's worth noting that I don't specifically see any of the special folders (app_code, etc) mentioned in the global web.config file. Maybe it's handled inside other HttpHandlers -- for instance, the handler for .aspx might contain some code that prevents serving of .aspx files located in special folders, etc.

URL rewriting problems with ASP .NET 2 on IIS7 and Vista

I've got a website running under ASP .NET 2/IIS7/Vista. I have a URL rewriting module which allows me to have extensionless URLs. To get this to work I have configured the system.webServer section of the config file such that all requests are forwarded to the aspnet_isapi.dll. I have also added the URL rewrite module to the modules section and set runAllManagedModulesForAllRequests to true.
When I start up the website and visit one of the pages that uses the URL rewriting, the page is rendered correctly. However if I then visit another page the site stops working and I get a 404 not found. I also find that my breakpoint in the URL rewriting module is not getting hit. It's almost as if IIS forwards the first request to the rewriter, but subsequent ones go somewhere else - the error page mentions Notification as being MapRequestHandler and Handler as being StaticFile.
If I then make a small change to the web.config file and save it, triggering the website to restart, I can then reload the page in the browser and it all works. Then I click another link and it's broken again.
For the record, here's a couple of snippets from the config file. First, under system.web:
<httpModules>
<add name="UrlRewriteModule" type="Arcs.CoopFurniture.TelesalesWeb.UrlRewriteModule, Arcs.CoopFurniture.TelesalesWeb" />
</httpModules>
and then, under system.webServer:
<system.webServer>
<modules runAllManagedModulesForAllRequests="true">
<add name="UrlRewriteModule" type="Arcs.CoopFurniture.TelesalesWeb.UrlRewriteModule, Arcs.CoopFurniture.TelesalesWeb" preCondition="managedHandler" />
</modules>
<handlers>
<add name="AspNet" path="*" verb="*" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll" resourceType="Unspecified" requireAccess="None" preCondition="classicMode,runtimeVersionv2.0,bitness32" />
</handlers>
<validation validateIntegratedModeConfiguration="false" />
</system.web>
The site is running under classic rather than integrated pipeline mode.
Does anyone out there have any ideas? I suspect my configuration is wrong somewhere but I can't seem to find where.
This is a bit of a long shot, but have you tried actually making the configuration changes inside of IIS?
I know that the web.config way is supposed to be 100% foolproof, but I've seen a few things where it helps to just configure it in IIS to get it working correctly.
You also may want to check out the new IIS7 rewrite module. you can read more about it here http://learn.iis.net/page.aspx/460/using-url-rewrite-module/, but chances are it will be more solid then your homegrown ISAPI filter
Try http://www.codeplex.com/urlrewriter it supports all the Apache mod_rewrite syntax and also supports Reverse Proxy.
If you're runnning in classic pipeline mode you don't need <system.webServer> section it is required for integrated mode
Enable wildcard script mapping
Open the IIS7 Manager and navigate to your site
Click on Handler Mappings
In the Action panel click on "Add Wild Card Script Map"
In the dialog point to aspnet_isapi.dll
Click Yes on the message box that asks you to confirm your mapping
In the action panel click on "View Ordered List" and move your WildcardScriptMap just before StaticFile Handler
This should bee enough.
I'm ashamed to admit this but it was a simple mistake by me :-(
In my URL rewriting module, the code to rewrite the request path was in the Init method, when it should have been inside an Application.BeginRequest handler. This explains why the rewriting worked only the first time the site was hit.
Sorry to have wasted your time people!

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