[Serusers] rtpproxy + nathelper problem

support support at cybertel.biz
Thu Dec 16 05:08:45 CET 2004


Hi,

I use the ser.cfg below. I have rtpproxy running. Sipura 2000 can register now without STUN server. However, the registration
port is 58698 not 5060.

Here is the SIP address after registration:
sip:811 at 218.xxx.xxx.xxx:58698




Thomas

# ----------- 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 
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"

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

# Uncomment this if you want to use SQL database
#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/rr.so"
loadmodule "/usr/local/lib/ser/modules/maxfwd.so"
loadmodule "/usr/local/lib/ser/modules/usrloc.so"
loadmodule "/usr/local/lib/ser/modules/registrar.so"
loadmodule "/usr/local/lib/ser/modules/textops.so"

# Uncomment this if you want digest authentication
# mysql.so must be loaded !
#loadmodule "/usr/local/lib/ser/modules/auth.so"
#loadmodule "/usr/local/lib/ser/modules/auth_db.so"

# !! Nathelper
loadmodule "/usr/local/lib/ser/modules/nathelper.so"

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

# -- usrloc params --

modparam("usrloc", "db_mode",   0)

# Uncomment this if you want to use SQL database 
# for persistent storage and comment the previous line
#modparam("usrloc", "db_mode", 2)

# -- auth params --
# Uncomment if you are using auth module
#
#modparam("auth_db", "calculate_ha1", yes)
#
# If you set "calculate_ha1" parameter to yes (which true in this config), 
# uncomment also the following parameter)
#
#modparam("auth_db", "password_column", "password")

# -- rr params --
# add value to ;lr param to make some broken UAs happy
modparam("rr", "enable_full_lr", 1)

# !! Nathelper
modparam("registrar", "nat_flag", 6)
modparam("nathelper", "natping_interval", 30) # Ping interval 30 s
modparam("nathelper", "ping_nated_only", 1)   # Ping only clients behind NAT

# -------------------------  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;
	};

        # !! Nathelper
	# Special handling for NATed clients; first, NAT test is
	# executed: it looks for via!=received and RFC1918 addresses
	# in Contact (may fail if line-folding is used); also,
	# the received test should, if completed, should check all
	# vias for rpesence of received
	if (nat_uac_test("3")) {
		# Allow RR-ed requests, as these may indicate that
		# a NAT-enabled proxy takes care of it; unless it is
		# a REGISTER

		if (method == "REGISTER" || ! search("^Record-Route:")) {
		    log("LOG: Someone trying to register from private IP, rewriting\n");

		    # This will work only for user agents that support symmetric
		    # communication. We tested quite many of them and majority is
		    # smart enough to be symmetric. In some phones it takes a configuration
		    # option. With Cisco 7960, it is called NAT_Enable=Yes, with kphone it is
		    # called "symmetric media" and "symmetric signalling".

		    fix_nated_contact(); # Rewrite contact with source IP of signalling
		    if (method == "INVITE") {
		        fix_nated_sdp("1"); # Add direction=active to SDP
		    };
		    force_rport(); # Add rport parameter to topmost Via
		    setflag(6);    # Mark as NATed
		};
	};

	# 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
	if (!method=="REGISTER") record_route();	

	# subsequent messages withing a dialog should take the
	# path determined by record-routing
	if (loose_route()) {
		# mark routing logic in request
		append_hf("P-hint: rr-enforced\r\n"); 
		route(1);
		break;
	};

	if (!uri==myself) {
		# mark routing logic in request
		append_hf("P-hint: outbound\r\n"); 
		route(1);
		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") {

# Uncomment this if you want to use digest authentication
#			if (!www_authorize("iptel.org", "subscriber")) {
#				www_challenge("iptel.org", "0");
#				break;
#			};

			save("location");
			break;
		};

		lookup("aliases");
		if (!uri==myself) {
			append_hf("P-hint: outbound alias\r\n"); 
			route(1);
			break;
		};

		# native SIP destinations are handled using our USRLOC DB
		if (!lookup("location")) {
			sl_send_reply("404", "Not Found");
			break;
		};
	};
	append_hf("P-hint: usrloc applied\r\n"); 
	route(1);
}

route[1] 
{
	# !! Nathelper
	if (uri=~"[@:](192\.168\.|10\.|172\.(1[6-9]|2[0-9]|3[0-1])\.)" && !search("^Route:")){
	    sl_send_reply("479", "We don't forward to private IP addresses");
	    break;
        };
	
	# if client or server know to be behind a NAT, enable relay
	if (isflagset(6)) {
	    force_rtp_proxy();
	};

	# NAT processing of replies; apply to all transactions (for example,
	# re-INVITEs from public to private UA are hard to identify as
	# NATed at the moment of request processing); look at replies
	t_on_reply("1");

	# send it out now; use stateful forwarding as it works reliably
	# even for UDP2TCP
	if (!t_relay()) {
		sl_reply_error();
	};
}

# !! Nathelper
onreply_route[1] {
    # NATed transaction ?
    if (isflagset(6) && status =~ "(183)|2[0-9][0-9]") {
        fix_nated_contact();
	force_rtp_proxy();
    # otherwise, is it a transaction behind a NAT and we did not
    # know at time of request processing ? (RFC1918 contacts)
    } else if (nat_uac_test("1")) {
        fix_nated_contact();
    };
}

#-- end of config --


On Wed, 2004-12-15 at 21:39, Ricardo Martinez wrote:
> Hello Thomas.
> I think you're missing a few important things.  First i don't see any checks
> for NAT'd endpoints, you need to do something like this:
> 
> if (nat_uac_test(1))
> 	setflag(1);
> 	force_rport();
> 	fix_nated_contact();
> 
> then in the INVITE:
> 
>        if (method=="INVITE") {
>                 record_route();
>                 if (isflagset(1))                         
> 				fix_nated_sdp("3");
>                 };
>                 /* set up reply processing */
>                 t_on_reply("1");
>         };
> 
> I'm using mediaproxy, so i am not sure about this, maybe somone that's using
> the nathelper module can help you better... you can check the example
> configuration file in the /modules/nathelper directory, that could give you
> some clues.
> +
> Cheers.
> 
> Ricardo
> 
> -----Mensaje original-----
> De: support [mailto:support at cybertel.biz]
> Enviado el: Miércoles, 15 de Diciembre de 2004 4:38
> Para: serusers at lists.iptel.org
> Asunto: [Serusers] rtpproxy + nathelper problem
> 
> 
> Hi,
> 
> I have installed the latest rtpproxy and run it with ser-0.8-14. I have
> also include nathelper modules. When I try to register a siprua gateway
> with SER, the IP is still 192.168.1.xx. It cannot be translated to NAT
> public IP.
> 
> Why is that so?
> 
> Thanks.
> 
> 
> Thomas
> 
> 
> Appendix: my ser.cfg
>   --------------------------------------------------
>   #
>   # $Id: ser.cfg,v 1.21 2003/06/04 13:47:36 jiri 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"
> 
>   alias=mydomain.dyndns.org
> 
>   # ------------------ module loading ----------------------------------
> 
>   
>   loadmodule "/usr/local/lib/ser/modules/nathelper.so"
>   loadmodule "/usr/local/lib/ser/modules/textops.so"
>   loadmodule "/usr/local/lib/ser/modules/sl.so"
>   loadmodule "/usr/local/lib/ser/modules/tm.so"
>   loadmodule "/usr/local/lib/ser/modules/rr.so"
>   loadmodule "/usr/local/lib/ser/modules/maxfwd.so"
>   loadmodule "/usr/local/lib/ser/modules/usrloc.so"
>   loadmodule "/usr/local/lib/ser/modules/registrar.so"
> 
>   
>   # ----------------- setting module-specific parameters ---------------
>   # -- usrloc params --
>   modparam("usrloc", "db_mode",   0)
> 
> 
>   # -- 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 (len_gt( 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");
> 			break;
> 		};
> 
> 		# native SIP destinations are handled using our USRLOC DB
> 		if (!lookup("location")) {
> 			sl_send_reply("404", "Not Found");
> 			break;
> 		};
> 	};
> 
>        #inserted by klaus
>        if (method=="INVITE") {
>                 record_route();
>                 force_rtp_proxy();
>                 /* set up reply processing */
>                 t_on_reply("1");
>         };
> 
> 
> 	# 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();
> 	};
> 
>   }
> 
>   #inserted by klaus
>   # all incoming replies for t_onrepli-ed transactions enter here
>   onreply_route[1] {
>        if (status=~"[12][0-9][0-9]")
>                 force_rtp_proxy();
>   }
> 
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> 
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