[Serusers] [jcollins at asgardsrealm.net: Routing difference between 0.8.10 and 0.8.12]

Jan Janak jan at iptel.org
Sun Dec 21 20:48:15 CET 2003


Jamin,

I acknowledge the problem. It is in ser, more exactly it's a collision
with one special feature that allows ser to work properly even with
implementations that remove parameters from Route header fields.

I need to investigate more, I am not sure yet whether we should change
the behaviour of ser or ask snom to change their preloaded route set.

Anyway, it's Christmas time now so I will get back to your problem
later, thanks for your patience.

  Jan.

On 18-12 16:37, Jamin W. Collins wrote:
> On Thu, Dec 18, 2003 at 10:58:22PM +0100, Jan Janak wrote:
> > I looked at the attached dumps. First of all, 0.8.10 and 0.8.12 handle
> > record routing differently. 0.8.10 implements strict routing while
> > 0.8.12 implements loose routing. 
> > 
> > The bug is in your script. Because 0.8.12 implements loose routing, the
> > Request-URI will contain the Contact of the callee. The Contact contains
> > the number of the callee -- 5803932.
> 
> So, should I be checking a different variable?  If so, which?  I didn't
> find anything about this in the Admin Guide.
> 
> > In your script you are searching for numbers beginning with 580 and
> > rewrite the hostname to a gateway. ACK and BYE will also contain the
> > number in the Request-URI -- see above, but they don't contain the IP of
> > your server in the Request-URI -- the IP of the callee is there.
> > 
> > But you don't check this and rewrite anyway.
> > 
> > The proper solution would be to search for numbers beginning with 580
> > inside the if (uri==myself) condition.
> 
> I've moved the search inside the if (uri==myself) condition as you
> suggested.  However, this has not (as I suspected) changed the behavior
> of the routing.  The 580XXXX calls still do not get routed to the
> gateway as they did in 0.8.10.  In the attached ngrep output you can see
> a call to sip:5803932 at 172.21.30.53 starting at 2003/12/18
> 17:15:44.976502.  However this request makes it past the 580XXXX check
> and is routed instead to 172.21.30.10, which is not what I would expect.
> Is there still something wrong with the new config?  Am I checking the
> wrong variable?  
> 
> > BTW, all searches and rewrites of Request-URI should be inside
> > uri==myself condition -- the condition will be true only for requests
> > establishing a dialog.
> > 
> > The Request-URI of requests WITHIN a dialog (BYE, ACK)
> > must not be changed.
> > 
> > In addition to that 0.8.10 and 0.8.12 configs are different. Your config
> > for 0.8.10 doesn't use record routing while the config for 0.8.12 does.
> 
> I am aware that they are slightly different.  I used the 0.8.12 default
> config as a starting point and attempted to translate the working 0.8.10
> configuration to the 0.8.12 syntax.
> 
> -- 
> Jamin W. Collins
> 
> Linux is not The Answer. Yes is the answer. Linux is The Question. - Neo

> #
> # $Id: ser.cfg,v 1.21.4.1 2003/11/10 15:35:15 andrei Exp $
> #
> # simple quick-start config script
> #
> 
> # ----------- global configuration parameters ------------------------
> 
> debug=3         # debug level (cmd line: -dddddddddd)
> fork=yes
> log_stderror=no # (cmd line: -E)
> 
> /* Uncomment these lines to enter debugging mode 
> debug=7
> fork=no
> log_stderror=yes
> */
> 
> check_via=no    # (cmd. line: -v)
> dns=no           # (cmd. line: -r)
> rev_dns=no      # (cmd. line: -R)
> port=5060
> children=4
> fifo="/tmp/ser_fifo"
> 
> # proxy server IP
> listen="172.21.30.53"
> 
> # ------------------ module loading ----------------------------------
> 
> # Uncomment this if you want to use SQL database
> loadmodule "/usr/lib/ser/modules/mysql.so"
> 
> loadmodule "/usr/lib/ser/modules/sl.so"
> loadmodule "/usr/lib/ser/modules/tm.so"
> loadmodule "/usr/lib/ser/modules/rr.so"
> loadmodule "/usr/lib/ser/modules/maxfwd.so"
> loadmodule "/usr/lib/ser/modules/usrloc.so"
> loadmodule "/usr/lib/ser/modules/registrar.so"
> 
> # Uncomment this if you want digest authentication
> # mysql.so must be loaded !
> #loadmodule "/usr/lib/ser/modules/auth.so"
> #loadmodule "/usr/lib/ser/modules/auth_db.so"
> 
> # ----------------- setting module-specific parameters ---------------
> 
> # persistent user registrations
> modparam("usrloc", "db_mode", 2)
> modparam("registrar", "default_expires", 172800)
> modparam("tm", "fr_inv_timer", 5 )
> modparam("tm", "fr_timer", 5 )
> 
> # -- rr params --
> # add value to ;lr param to make some broken UAs happy
> modparam("rr", "enable_full_lr", 1)
> 
> # -------------------------  request routing logic -------------------
> 
> # main routing logic
> 
> route{
> 
>         # 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");
>                 break;
>         };
>         if ( msg:len > max_len ) {
>                 sl_send_reply("513", "Message too big");
>                 break;
>         };
> 
>         # we record-route all messages -- to make sure that
>         # subsequent messages will go through our proxy; that's
>         # particularly good if upstream and downstream entities
>         # use different transport protocol
>         record_route(); 
>         # loose-route processing
>         if (loose_route()) {
>                 t_relay();
>                 break;
>         };
> 
> 
>         
>         # if the request is for other domain use UsrLoc
>         # (in case, it does not work, use the following command
>         # with proper names and addresses in it)
>         if (uri==myself) {
> 
>                 if (method=="REGISTER") {
>                         save("location");
>                         log(1, "Registration request.");
>                         break;
>                 };
> 
> 		# check for 911 calls
>         	if (uri=~"^sip:911 at .*") {
> 			log(1, "911 Call");
> 	                rewritehost("172.21.30.51");
>         	        t_relay();
>                 	break;
> 	        };
> 
> 		# pass local calls off to the gateway
> 		if (uri=~"^sip:580[0-9][0-9][0-9][0-9]@") {
> 			log(1, "Local call sent to gateway");
> 			rewritehost("172.21.30.51");
> 			t_relay();
> 			break;
> 		};
> 
>                 # native SIP destinations are handled using our USRLOC DB
>                 if (!lookup("location")) {
>                         log(1, "Location lookup failure.");
>                         if ((src_ip==172.21.30.10) || (src_ip==172.21.30.12)) {
>                                 log(1, "Request from IC server trying to go back
>  to IC server.");
>                                 sl_reply_error();
>                         } else {
>                                 rewritehost("172.21.30.10");
>                                 log (1, "Sending request to the first server.");
>                                 t_on_failure ("1");
>                                 t_relay();
>                         };
>                         break;
>                         
>                 };
>         };
>         # forward to current uri now; use stateful forwarding; that
>         # works reliably even if we forward from TCP to UDP
>         if (!t_relay()) {
>                 sl_reply_error();
>         };
> 
> }
> 
> failure_route[1]{
>         rewritehost("172.21.30.12");
>         log(1, "Sending request to the second server.");
>         t_on_failure("2");
>         append_branch();
>         t_relay();
> }
> 
> failure_route[2]{
>         rewritehost("172.22.30.51");
>         log(1, "Sending request to the gateway.");
>         append_branch();
>         t_relay();
> }


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