Fixing external links (replace escaped ? and =)

Hi mate,

here's one for you:

    when HTTP_REQUEST {

 Disable the stream filter for all requests
STREAM::disable

     remove the compression offerings from the client
HTTP::header remove "Accept-Encoding"
}
when HTTP_RESPONSE {

 Check if response type is text
if {[HTTP::header value Content-Type] contains "text"}{

   Replace
  STREAM::expression {@%3f@?@@%3d@=@}

   Enable the stream filter for this response only
  STREAM::enable

}
}

You'll need to apply a stream profile to your virtual server too.

Ryan,

Thanks for your reply. That is very interesting. Would a stream operation be more efficient that a string map operation over the URL?

Also, will this work on inbound gets? I need to intercept bad external links and this looks like it will fix replies.

Thanks, Mike

GET requests ('Inbound gets') can (and should) be handled without using STREAM, as you have direct access to requests via HTTP::path, HTTP::uri, et cetera.

Example:

when HTTP_REQUEST {

    if { [HTTP::path] starts_with "/docs/xyz/" } {

        << do something >>

    }

}

See the wiki for details.

By the way, if you need to decode requests you may want to take a look at URI::decode (see wiki).

Thanks all for helping me get the gears turning. I think I have a solution and I'd like some expert feedback (in case it's just a bad approach).

Here is the rule I came up with:

when HTTP_REQUEST { 
set ::theuri [HTTP::uri] 
log local0. "the URI is $::theuri"
switch -glob $::theuri {
     "*%3[fFdD]*" {
    set ::myuri [string map -nocase {"%3f" "?" "%3d" "="} $::theuri]
    HTTP::redirect "http://[HTTP::host]$::myuri"
  }
   }
}

Let me know what you think.

Thanks, Mike