Adding to header and PDU content

To insert the header, you can use the HTTP_REQUEST event:

when HTTP_REQUEST {
    Insert HTTP header
   HTTP::header insert start {}
}

To insert the string in the payload, I thought you needed to collect the HTTP data first. I'm actually a bit surprised to see in the codeshare example HTTP::payload replace being used in the HTTP_RESPONSE event (as opposed to HTTP_RESPONSE_DATA).

If you do need to collect the data in order to modify the payload, I think it would actually be more efficient to use a stream profile to 'replace' a known string in the payload with that string plus what you want to insert.

Here's what I'm thinking for the rule:

when HTTP_REQUEST {
    Check if the request is a POST to a specific path with a content type containing "xml"
   if {[HTTP::path] starts_with "/mms-rs" and [HTTP::method] eq "POST" and [HTTP::header value "Content-Type" contains "xml"}{
       Insert HTTP header
      HTTP::header insert start {}
       Enable the stream profile and set the find/replace strings
      STREAM::enable
      STREAM::expression {@Content-Type:text/xml; charset="utf-8"@Content-Type:text/xml; charset="utf-8"...Content-ID: @}
   }
}

The rule requires a blank stream profile added to the virtual server.

The stream expression format is described on the wiki page (Click here).

The only catch, is that I haven't figured out how to insert a carriage return and line feed where the three periods are in the STREAM::expression. I'm not sure if you could insert a \r\n, the value in hex 0D0A, or something else altogether. I can't test this right now to see either.

Aaron