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David_DeLaune_2's avatar
David_DeLaune_2
Icon for Nimbostratus rankNimbostratus
May 25, 2007

Modifying Request Content Without Client Sending All Content

Newbie question...

 

We are attempting to abort large HTTP single file uploads (> 30MB) without the client sending all of the content (having the client wait for all the bits to be sent) by looking at the Content-length header and making a determination on the size.

 

 

Based on that scenario, I have a couple of questions...

 

 

Does the F5 iRule facility provide the capability to read the stream as the bytes come across and populate the internal variables so that you can make these decisions before reading all of the bytes in the stream? In other words, read the HTTP headers and populate the associated iRule variables before all of the content is sent from the client.

 

 

Can you tell the F5 to stop reading the bytes from the client and replace the request content with something different so that the client does not end up sending all of the content.

 

 

Pseudo code:

 

 

if Content-Length > 30MB

 

then

 

request content = ""

 

URI = "/someuri/fileuploaderror.html"

 

end if

 

 

Thanks very much.

 

 

-Dave

 

application delivery
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  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    May 28, 2007
    Does the client always set the content-length header in the request when doing an HTTP upload? If so, you could use something like this:

     

     

    
when HTTP_REQUEST {
   if {[HTTP::method]=="POST" and [HTTP::header exists "Content-Length"] and [HTTP::header value Content-Length] > 30000000}{
      HTTP::respond 413 content "request size too large"
   }
}

     

     

    This rule will trigger when BIG-IP parses the HTTP request headers, but before any data is sent by the client. The rule will look for POST requests with a Content-Length header whose value is set to greater than 30M bytes and respond with an HTTP 413 code and content of "request size too large". No request will be sent to the web server in the pool for such requests.

     

     

    Aaron