[Serusers] handling multicast - sr-users

20 Jun 2003

Hi,

I want SER to handle forwarding multicast requests.
To do that, I want to realise this scenario :
All the UACs which want to belong to the multicast group need to register 
themselves with the same multicast URI.
When SER receive request with that multicast URI, it looks for all the 
contacts for the username of that URI in usrloc (with lookup() function call) 
and then forward the request to all the contacts found (with t_relay() 
function call). 

But I don't want SER to forward the request to the sender.

That's why I want to ensure myself that URIs which have been added to the 
destination set and the one which rewrites the request URI (after the 
lookup() function call) don't match with SIP URI in the Contact header field 
of the processing request.

Here is the test code :

###########################
Server: Sip EXpress router (0.8.11pre29 (i386/linux))
Platform: GNU/Linux 2.4.18-14 i686
###########################

# ------------------ module loading ----------------------------------

loadmodule "/usr/local/lib/ser/modules/mysql.so"
loadmodule "/usr/local/lib/ser/modules/sl.so"
loadmodule "/usr/local/lib/ser/modules/tm.so"
loadmodule "/usr/local/lib/ser/modules/usrloc.so"
loadmodule "/usr/local/lib/ser/modules/registrar.so"

# ----------------- setting module-specific parameters ---------------

# -- registrar params --
# to add contacts in the destination set
modparam("registrar", "append_branches", 1)

# -- usrloc params --
# use SQL database for persistent storage
modparam("usrloc", "db_mode", 1)

# -------------------------  request routing logic -------------------

# main routing logic

route{

	if (uri==myself)
	{

		(...)	

		# registering
		if (method=="REGISTER") 
		{
			save("location");
			break;
		};

		(...)

		# to find contacts, rewrite request URI and
		# add contacts to the destination set
		if (!lookup("location")) 
		{
			sl_send_reply("404","not found");
			break;
		};

		# Here I want to compare the destination set 
		# and the rewrited request URI with the Contact header
		# field of the processing request before forwarding
		...

		# forward
		if (!t_relay()) 
		{
			 sl_reply_error();
			 break;
		};

		(...)

	}else{
		(...)
		}

}

################

I think it's not possible using only ser script functionalities. I think I 
have to write a specific function in a specific module to do that (based on 
lookup() function).
What do you think about it ? Any suggestions are welcomed.

Thanks in advance.

Matthieu Saunier