[Serusers] Needing help with CPL

[Bogdan-Andrei IANCU]

Hi José,

Sorry for the delay. Here are some useful hints setting up correctly CPL 
processing:
-  from security reason, the cpl_process register() should be also 
placed after the authentication block. I don't know what tool are you 
using for sending the register with CPL (if you use CPLEd, it's able to 
authenticate);
- for CPL processing - As written in README file, the INVITE transaction 
must be created before calling the cpl_run_script(), so you can do 
something like:

    if (method=="INVITE") {
        # cpl interpreter requires a pre-created transaction for
        # the processed INVITE
        if ( !t_newtran() ) {
            # it'a a retransmission
            break;
        };
        if ( !cpl_run_script("incoming") ) {
            # script execution failed
            t_reply("500","CPL script execution failed");
            break;
        };
        # we get here only if the CPL interpreter decided that server
        # should follow it default behavior

        # mark that there is already a created
        # transaction for current INVITE
        setflag(3);
    };

keep in mind that you cannot use t_relay() when the transaction is 
already created (after calling t_newtran() ), so use a flag for marking 
if the transaction is created or not, and instead of t_relay(), do:
    if ( !isflagset(3) ) {
        # build a new fresh transaction and forward
        if (!t_relay()) {
            sl_reply_error();
        };
    } else {
        # transaction exists -> do just forward
        if (!t_forward_nonack_uri()) {
            sl_reply_error();
        };
    };


Anyhow, if you what to have incoming and outgoing CPL processing, 
logical will be to place the outgoing first.

Regards,
Bogdan




José Nunes wrote:

> Greetings everyone,
>  
> I'm trying to use the cpl-c module in ser 0.8.12.
> I uploaded through CPLEd a small script that would redirect to user1 
> the calls destined to user3.
> Calls between users that don´t have a CPL script associated are 
> established.
> But if a call is destined to user3, when the cpl_run_script function 
> is called, I get the following errors from the logs:
>  
> ERROR: t_reply: cannot send a t_reply to a message for which no 
> T-state has been established
> ERROR:cpl_invoke_script: unable to send 100 reply!
> My configuration file is:
>  
> #
> # $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"
> fifo_mode=0666  #permite acesso ao 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/cpl-c.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"
>  
> # 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"
>  
> # ----------------- 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)
>  
> # -- cpl-c module --
> modparam("cpl-c","cpl_db","mysql://ser:heslo@localhost/ser")
> modparam("cpl-c","cpl_table","cpl")
> modparam("cpl-c","cpl_dtd_file","/usr/local/etc/ser/cpl-06.dtd")
> modparam("cpl-c","log_dir","/var/log/ser/cpl")
> modparam("cpl-c","proxy_recurse",0)
>  
> # -------------------------  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;
>  };
>  lookup("aliases");
>  setflag(1);
>  
>  # 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=~"klingon.av.it.pt") {
>  
>   if (method=="REGISTER") {
>  
>  # Uncomment this if you want to use digest authentication
>    if(!cpl_process_register())
>    {
>     break;
>    };
>    if (!www_authorize("klingon.av.it.pt", "subscriber")) {
>     www_challenge("klingon.av.it.pt", "0");
>     break;
>    };
>    
>    save("location");
>    break;
>    
>   };
>  
>   if(method=="INVITE") {
>    log(1,"Invite \n");
>    cpl_run_script("incoming");
>    cpl_run_script("outgoing");
>   };
>  
>   # 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
>  if (!t_relay()) {
>   sl_reply_error();
>  };
>  
> }
> If I use t_newtran prior to cpl_run_script, I get errors for every calls:
>      ERROR: t_newtran: transaction already in process 0x422baf48
>      ERROR: sl_reply_error used: I'm terribly sorry, server error 
> occured (1/SL)
>      WARNING: script writer didn't release transaction
> Can anyone help me on this?
>  
> José Nunes
>
>------------------------------------------------------------------------
>
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