[Serusers] nathelper rewrite SDP problem

zak Huang zakhuang at gmail.com
Fri Aug 20 06:31:23 UTC 2004


Hi all, 

I am using last stable SER and Nathelper from CVS and last RTPPROXY from CVS
too.

     UA1--------> SER & RTPPROXY <--------- NAT <-------------- UA2
10.0.1.10           10.0.1.135                   10.0.1.118          
192.168.1.2



1. When UA2 INVITE UA1 through SER , nathelper rewrite SDP. There is an error .
    Connection  Information (c) :IN IP4 10.0.1.13510.0.1.135 
                                                       ^^^^^^^^^^^^^^^^^^^^^^^^ 
2. UA1 couldn't INVITE UA2

Can you tell me how to correct it.

Attached is my ser.cfg.

Thanks in advanced:

kaz
------------------------------------------------------------------------------------------------------------------------

#
# $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"

# ------------------ 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/acc.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 ---------------
modparam("acc", "log_level", 1)
modparam("acc", "log_flag", 1)

modparam("acc", "report_ack", 1)
modparam("acc", "db_flag", 1 )
# report to syslog: From, i-uri, status, digest id
modparam("acc", "log_fmt", "fisu" )


# -- 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)

#modparam("acc", "db_url", "sql://root:@localhost/ser")

modparam("registrar", "nat_flag", 6)
modparam("nathelper", "natping_interval", 30)
modparam("nathelper", "ping_nated_only", 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;
	};

	# !! 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");
		    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
	record_route();
        setflag(1);	
	# loose-route processing
	if (loose_route()) {
		append_hf("P-hint: rr-enforced\r\n"); 
		route(1);
#		t_relay();
		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=="INVITE") {
#			record_route();
			if (isflagset(6)) {
				force_rtp_proxy();
			};
     		};

		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;
		};
	};
	# forward to current uri now; use stateful forwarding; that
	# works reliably even if we forward from TCP to UDP
	append_hf("P-hint: usrloc applied\r\n"); 	
	route(1);
}

route[1] 
{
#	if (uri=~"[@:](192\.168\.|10\.|172\.16)" && !search("^Route:")){
#        	sl_send_reply("479", "We don't forward to private IP addresses");
#        	break;
#        };
        if (isflagset(6)) {
        	force_rtp_proxy();
        	t_on_reply("1");
        	append_hf("P-Behind-NAT: Yes\r\n");
        };
	# send it out now; use stateful forwarding as it works reliably
	# even for UDP2TCP
	if (!t_relay()) {
		sl_reply_error();
	};
}

onreply_route[1] {
    if (status =~ "(183)|2[0-9][0-9]") {
        fix_nated_contact();
        force_rtp_proxy();
    };
}


onreply_route[2] {
    # 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();
    };
}




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