Forum Discussion

Nathan_Bultman_'s avatar
Nathan_Bultman_
Historic F5 Account
Oct 24, 2009

Header replacement assistance

Problem:

 

 

When a request comes in, if it has the header MyHeader (regardless of value), we need to change the Referer header value, from http://domain.com/path/object to https://domain.com/path/object

 

 

I've tried to accomplish this with:

 

 

when HTTP_REQUEST {

 

if {[HTTP::header exists "MyHeader"]} {

 

HTTP::header replace Referer [ https://domain.com[HTTP::uri ] ]

 

}

 

}

 

 

Then sending a request:

 

 

 

GET /index.html HTTP/1.1

 

host: 1.1.1.1

 

MyHeader: foo

 

Referer: http://domain.com

 

 

 

But I'm seeing the same referer header on the request when it egresses the LTM.

 

 

I'm a relative noob on iRules, so this might be something simple. Am I using 'Exists' correctly?

 

 

Thanks in advance.
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  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Oct 25, 2009
    Hi Nathan,

    I think you should find a TCL error in /var/log/ltm from trying to execute the value of https://domain.com[HTTP::uri] with the square braces that is wrapped in.

    Can you clarify what you actually want to do in the Referer header update. Do you just want to replace http:// with https:// and preserve the rest of the header value? Your current rule is replacing the original Referer value with https:// and the current URI. The current URI wouldn't typically be the same as the Referer URI.

    Maybe try this: 

     
 when HTTP_REQUEST { 
  
    log local0. "[IP::client_addr]:[TCP::client_port]: New [HTTP::method] request to [HTTP::host][HTTP::uri]\ 
       with Referer [HTTP::header Referer]" 
  
    if {[HTTP::header exists "MyHeader"]} {  
       log local0. "[IP::client_addr]:[TCP::client_port]: Updating Referer to\ 
          [string map -nocase {http:// https://} [HTTP::header Referer]" 
       HTTP::header replace Referer "[string map -nocase {http:// https://} [HTTP::header Referer]" 
    } 
 } 
 when HTTP_REQUEST priority 501 { 
    log local0. "[IP::client_addr]:[TCP::client_port] (501): Current Referer [HTTP::header Referer]" 
 }

    Aaron