[OpenSER-Users] How do I detect INVITE loop

[Jan ONDREJ (SAL)]

On Mon, Sep 24, 2007 at 01:32:10PM +0200, Andreas Sikkema wrote:
> Is there a way for an OpenSER instance to detect 
> if an incoming INVITE message has earlier been 
> processed by itself? Record-Route is on, so there 
> should be a Route message, but I suppose the Via 
> headers could also contain the information.

OpenSER is protected to infinite loops vith maxfwd testing in default
config.

        # initial sanity checks -- messages with
        # max_forwards==0, or excessively long requests
        if (!mf_process_maxfwd_header("10")) {
                sl_send_reply("483","Too Many Hops");
                exit;
        };

Another way is testing msg length also from default config:

        if (msg:len >=  2048 ) {
                sl_send_reply("513", "Message too big");
                exit;
        };

I think it's enough, but you can write your own test based on
regular expression, for example:
  if (search("Via: .*myip")) {
  }
or something similiar. I don't know, if these loops are not normal in
special situations. I think maxfwd is better idea.

			SAL