XI 3.1 SP2 Retrieve IP - Calculation Extension Points, OpenDoc or ?

Question

On a XI 3.1 SP2 Tomcat stack I need to retrieve an use a client IP Address to help determine security for shifting users.
It's easy enough to retrieve the IP via jsp but the question is how to get that value into WEBI?
I've read Ueda's Calc Ext Point examples - they're for .Net but one can assume that the same could be applied via java/jsp?
The alternative would be to manipulate the OpenDocument.jsp code to retrieve the ip to be used as a parameter but I'm not too keen on altering existing code.
As mentioned, it's simple enough to include the code to retrieve the ip the logon.jsp module but there again it means changing the system code and determining a method to get this out and into WEBI i.e. similar to @bouser

Answer 1

Mike -
How does the IP address need to be recognized and recorded?  At view-time of the report via InfoView?   During adhoc report creation (webi query panel) ?
Does Auditor not satisfy this requirement?
As far as using EPs (these are actually in C btw) - this could get a bit murky as you'd still need to manage a way to enforce the custom function to be present in the Webi report.
If you need to essentially record IPs of users who are using any of the available document viewing interfaces (PDF, interactive, etc) then I'd add some custom code to viewDocument.jsp that grabs the client IP (how will you account for proxies, or is this a non-issue?) and silently stamps the address in a footer cell of the Webi report or merely records the view action elsewhere without actually touching Webi.
I don't think you can escape the not wanting to customize InfoView code, unless you roll your own viewer and force users to use that instead.
Hope this helps