[Serusers] RTPPROXY

[Kiko Vives]

Hi all.

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

It compiles OK and it seems to work fine until it tries to proxy the media
RTPs when I get :

"ERROR: force_rtp_proxy: can't extract body form the message"

Attached is my ser.cfg.

Thanks in advanced:

Kiko


#
# $Id: nathelper.cfg,v 1.1.2.1 2003/11/24 14:47:18 janakj Exp $
#
# simple quick-start config script including nathelper support

# This default script includes nathelper support. To make it work
# you will also have to install Maxim's RTP proxy. The proxy is enforced
# if one of the parties is behind a NAT.
#
# If you have an endpoing in the public internet which is known to
# support symmetric RTP (Cisco PSTN gateway or voicemail, for example),
# then you don't have to force RTP proxy. If you don't want to enforce
# RTP proxy for some destinations than simply use t_relay() instead of
# route(1)
#
# Sections marked with !! Nathelper contain modifications for nathelper
#
# NOTE !! This config is EXPERIMENTAL !
#
# ----------- global configuration parameters ------------------------

debug=5         # debug level (cmd line: -dddddddddd)
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]
{
     # 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();
    };
}