###################################
####### M2 Kamailio proxy/LNP #####
###################################


####### Global Parameters #########

debug        = 2
log_stderror = no
log_facility = LOG_LOCAL0
fork         = yes
children     = 4
port         = 5060
listen       = udp:192.168.1.126:5060
disable_tcp  = yes
dns          = no
rev_dns      = no
mpath        = "/usr/local/lib64/kamailio/modules/"

server_header       = "Server: M2 Proxy server"
user_agent_header   = "User-Agent: M2 Proxy server"

####### Modules Section ########

loadmodule "tm"
loadmodule "kex"
loadmodule "sl"
loadmodule "rr"
loadmodule "pv"
loadmodule "maxfwd"
loadmodule "textops"
loadmodule "siputils"
loadmodule "xlog"
loadmodule "sanity"
loadmodule "nat_traversal"
loadmodule "dispatcher"
loadmodule "ctl"
loadmodule "jsonrpcs"
loadmodule "db_mysql"
loadmodule "usrloc"
loadmodule "registrar"
loadmodule "auth"
loadmodule "auth_db"
loadmodule "nathelper"
loadmodule "m2_mnp"

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

# ----- ctl -----------

modparam("ctl", "binrpc", "/var/run/kamailio/kamailio_ctl")

# ----- tm params -----
modparam("tm", "fr_timer", 3000)
modparam("tm", "fr_inv_timer", 40000)
modparam("tm", "auto_inv_100_reason", "Trying")

# ----- rr params -----
# add value to ;lr param to cope with most of the UAs
modparam("rr", "enable_full_lr", 1)
# do not append from tag to the RR (no need for this script)
modparam("rr", "append_fromtag", 0)

# ----- dispatcher params -----
modparam("dispatcher", "list_file", "/usr/src/m2/kamailio/dispatcher.list")
modparam("dispatcher", "xavp_dst", "_dsdst_")
modparam("dispatcher", "xavp_dst_mode", 1)
modparam("dispatcher", "xavp_ctx", "_dsctx_")
modparam("dispatcher", "xavp_ctx_mode", 1)
modparam("dispatcher", "ds_ping_method", "OPTIONS")
modparam("dispatcher", "ds_ping_interval", 30)
modparam("dispatcher", "ds_probing_mode", 1)
modparam("dispatcher", "ds_inactive_threshold", 1)
modparam("dispatcher", "ds_probing_threshold", 1)
modparam("dispatcher", "ds_hash_size", 12)
modparam("dispatcher", "ds_ping_reply_codes", "code=404")

# ----- nathelper -----
modparam("nathelper", "natping_interval", 10)
modparam("nathelper", "received_avp", "$avp(received_avp)")

# ----- registrar -----
modparam("registrar", "default_expires", 1800)
modparam("registrar", "min_expires", 60)
modparam("registrar", "max_expires", 180)
modparam("registrar", "received_avp", "$avp(received_avp)")

# ----- usrloc -----
modparam("usrloc", "version_table", 0)
modparam("usrloc", "db_mode", 3)
modparam("usrloc", "db_url", "mysql://kamailio:kamailio@localhost/mor")

# ----- auth db -----
modparam("auth_db", "version_table", 0)
modparam("auth_db", "calculate_ha1", yes)
modparam("auth_db", "user_column", "op_username")
modparam("auth_db", "password_column", "op_password")
modparam("auth_db", "db_url", "mysql://kamailio:kamailio@localhost/mor")

# ------- m2_mnp ----
# modparam("m2_mnp", "dbhost", "localhost")
# modparam("m2_mnp", "dbname", "mor")
# modparam("m2_mnp", "dbuser", "root")
# modparam("m2_mnp", "dbport", 3306)

####### Routing Logic ########

# main request routing logic

route {

    # per request initial checks
    route(REQINIT);

    # handle OPTIONS
    if (is_method("OPTIONS")) {
        sl_send_reply("200", "OK");
        exit;
    }

    # check NAT
    if (client_nat_test("3")) {
        fix_contact();
    }

    # handle not implemented request
    if (!ds_is_from_list() && is_method("SUBSCRIBE")) {
        xlog("L_NOTICE", "Rejecting $rm from $si:$sp\n");
        sl_send_reply("501", "Not Implemented");
        exit;
    }

    # handle requests within SIP dialogs
    route(WITHINDLG);

    ### only initial requests (no To tag)

    # CANCEL processing
    if (is_method("CANCEL")) {
        if (t_check_trans()) {
            t_relay();
        }
        exit;
    }

    t_check_trans();

    # record routing for dialog forming requests (in case they are routed)
    if (is_method("INVITE")) {
        record_route();
        m2_mnp();
        if ($avp(m2_mnp:cache_status) == "1") {
            xlog("L_NOTICE", "NOT Found in cache");
            route(SEND_TO_LNP_SERVER);
        } else {
            xlog("L_NOTICE", "Found in cache");
            route(DISPATCH_AND_RELAY);
        }
    }

    if (is_method("REGISTER")) {
        route(REGISTER);
    }

    route(RELAY);
}

route[SEND_TO_LNP_SERVER] {
    ## Send request to LNP server
    xlog("L_NOTICE", "SEND_TO_LNP_SERVER");
    seturi("sip:test@192.168.1.111"); # LNP SERVER IP CHANGE ME
    t_on_failure("RESPONSE_FROM_LNP");
    t_relay();
    exit;
}

failure_route[RESPONSE_FROM_LNP] {
    ## Send to M2
    xlog("L_NOTICE", "RESPONSE_FROM_LNP: FAILURE RESPONSE FROM LNP SERVER. code[$rr $rs]");

    if (t_check_status("302")) {
        xlog("L_NOTICE", "RESPONSE_FROM_LNP: get contacts.");
        m2_mnp_contacts();
    }
    route(DISPATCH_AND_RELAY);
}

route[DISPATCH_AND_RELAY] {
    t_check_trans();
    xlog("L_NOTICE", "DISPATCH_AND_RELAY.");
    revert_uri();

    # dispatch destinations
    if (!ds_is_from_list()) {
        route(DISPATCH);
    }
    route(RELAY);
}

route[RELAY] {
    if (!t_relay()) {
        sl_reply_error();
    }
    exit;
}

# Per SIP request initial checks
route[REQINIT] {
    if (!mf_process_maxfwd_header("10")) {
        sl_send_reply("483", "Too Many Hops");
        exit;
    }

    if(!sanity_check("1511", "7")) {
        xlog("Malformed SIP message from $si:$sp\n");
        exit;
    }
}

# Handle requests within SIP dialogs
route[WITHINDLG] {
    if (has_totag()) {
        # sequential request withing a dialog should
        # take the path determined by record-routing
        if (loose_route()) {
            route(RELAY);
        } else {
            if (is_method("ACK")) {
                if (t_check_trans()) {
                    # non loose-route, but stateful ACK;
                    # must be ACK after a 487 or e.g. 404 from upstream server
                    t_relay();
                    exit;
                } else {
                    # ACK without matching transaction ... ignore and discard.
                    exit;
                }
            }
            sl_send_reply("404", "Not here");
        }
        exit;
    }
}

# Dispatch requests
route[DISPATCH] {
    # round-robin dispatching on gateways group '1'
    if (!ds_select_dst("1", "4")) {
        send_reply("404", "No destination");
        exit;
    }

    # remove special M2 proxy headers
    # only M2 proxy is allowed to set these headers
    remove_hf("x-M2-Originator-ip");
    remove_hf("x-M2-Originator-port");

    # set specials M2 proxy headers
    append_hf("x-M2-Originator-ip: $si\r\n");
    append_hf("x-M2-Originator-port: $sp\r\n");

    xlog("L_NOTICE", "$rm from $si:$sp going to <$ru> dispatched to <$du> server\n");
    return;
}

# Handle registrations
route[REGISTER] {
    if (nat_uac_test("23")) {
        fix_nated_register();
    }

    if ($expires(max) == 0) {
        xlog("L_NOTICE", "Unregistration attempt from $ct\n");
    } else {
        xlog("L_NOTICE", "Registration attempt from $ct\n");
    }

    $var(auth_result) = www_authorize("$td", "devices");

    if ($var(auth_result) < 0) {
        switch($var(auth_result)) {
        case -1:
            xlog("L_NOTICE", "Generic authentication error (Bad credentials, couldn't parse credentials, no memory left, couldn't fetch from table, ...)\n");
            break;
        case -2:
            xlog("L_NOTICE", "Registration error - wrong password for user '$au'\n");
            break;
        case -3:
            xlog("L_NOTICE", "Registration error - authentication user '$au' does not exist\n");
            break;
        case -4:
            xlog("L_NOTICE", "Registration error - the nonce has expired for user '$au'\n");
            break;
        case -5:
            xlog("L_NOTICE", "Challenging registration attempt from $ct (asking for credentials)\n");
            break;
        case -6:
            xlog("L_NOTICE", "Registration error - the nonce has already been used to authenticate a previous request for user '$au'\n");
            break;
        case -8:
            xlog("L_NOTICE", "Registration error - authuser mismatch for '$au' (From/To/RURI user does not match the authentication user)\n");
            break;
        default:
            xlog("L_NOTICE", "Unknown registration error\n");
        }

        www_challenge("$td", "1");
        exit;
    };

    if (!save("location")) {
        xlog("L_NOTICE", "Cannot save registration information for user '$au'\n");
        sl_reply_error();
    }

    if ($expires(max) == 0) {
        xlog("L_NOTICE", "User '$au' is successfully unregistered\n");
    } else {
        xlog("L_NOTICE", "User '$au' is successfully registered\n");
    }

    exit;
}