######## Generic Hash Table container in shared memory ########
modparam("htable", "htable", "failover=>size=16;autoexpire=120")

####### Dispatcher module  ########
loadmodule "dispatcher.so"
modparam("dispatcher", "list_file", "/etc/kazoo/kamailio/dbtext/dispatcher")
modparam("dispatcher", "flags", 2)
modparam("dispatcher", "use_default", 0)
modparam("dispatcher", "force_dst", 1)
modparam("dispatcher", "dst_avp", "$avp(ds_dst)")
modparam("dispatcher", "attrs_avp", "$avp(ds_attrs)")
modparam("dispatcher", "grp_avp", "$avp(ds_grp)")
modparam("dispatcher", "cnt_avp", "$avp(ds_cnt)")
modparam("dispatcher", "hash_pvar", "$avp(ds_grp)")
# modparam("dispatcher", "setid_pvar", "$var(setid)")
modparam("dispatcher", "ds_ping_method", "OPTIONS")
modparam("dispatcher", "ds_ping_interval", 10)
modparam("dispatcher", "ds_probing_threshhold", 3)
modparam("dispatcher", "ds_probing_mode", 1)
modparam("dispatcher", "ds_ping_reply_codes", "501,403,404,400,200")

## Dispatcher Groups:
## 1 - Primary media servers
## 2 - Backup media servers
## 3 - Alternate media server IPs (used only for classification)
## 10 - Presence servers (if not locally handled)
## 20 - Registrar servers (if not locally handled)

####### Dispatcher Logic ########
route[DISPATCHER_CLASSIFY_SOURCE]
{
    if (ds_is_from_list("1", "1") ||
		ds_is_from_list("2", "1") ||
		ds_is_from_list("3", "1") ||
		ds_is_from_list("10", "1") ||
		ds_is_from_list("20", "1")) {
        xlog("L_INFO", "$ci|log|originated from internal sources");

        setflag(FLAG_INTERNALLY_SOURCED);
    } else {
        xlog("L_INFO", "$ci|log|originated from external sources");
    }
}

# Take the routes from dispatcher - hash over callid
# If prefered route defined, reorder the destionations
route[DISPATCHER_FIND_ROUTES]
{
    if ($sht(failover=>$ci::current) != $null) {
        $du = $sht(failover=>$ci::current);
        return;
    }
        
    $var(ds_group) = 1;

    #!ifndef PRESENCE-ROLE
    if (is_method("SUBSCRIBE")) {
        $var(ds_group) = 10;
    }
    #!endif

    #!ifndef REGISTRAR-ROLE
    if (is_method("REGISTER")) {
        $var(ds_group) = 20;
    }
    #!endif

    if (!ds_select_dst("$var(ds_group)", "0")) {
        # if we selected from group 1, try again in group 2
        if ($var(ds_group) == 1) {
                if (!ds_select_dst("2", "0")) {
                    xlog("L_WARN", "$ci|end|no servers avaliable in group 1 or 2");
                    sl_send_reply("480", "All servers busy");
                    exit;
                }
        } else {
            xlog("L_INFO", "$ci|end|no servers avaliable in group $var(ds_group)");
            sl_send_reply("480", "All servers busy");
            exit;
        }
    } else {

        # if we selected from group 1 and there are less than 3 available servers, choose from group 2
        if ($var(ds_group) == 1 && $var(ds_cnt)< 3) {

            # clear $avp(ds_dst) and search in group 2
            $(avp(ds_dst)[*]) = $null;

            if (!ds_select_dst("2", "0")) {
                xlog("L_ERR", "$ci|end|no servers avaliable in group 2");
                sl_send_reply("480", "All servers busy");
                exit;
            }

        }

    }

    $var(contact_uri) = $(ct{tobody.user}) + "@" + $(ct{tobody.host});
    $var(from_uri) = @from.uri.user + "@" + @from.uri.host;
    if ($sht(associations=>$var(from_uri)) != $null) {
        $var(association) = $var(from_uri);
        $var(prefered_route) = $sht(associations=>$var(association));
        xlog("L_INFO", "$ci|log|from uri $var(from_uri) associated with media server $var(prefered_route)");
        route(DISPATCHER_REORDER_ROUTES);
    } else if ($sht(associations=>$var(contact_uri)) != $null) {
        $var(association) = $var(contact_uri);
        $var(prefered_route) = $sht(associations=>$var(association));
        xlog("L_INFO", "$ci|log|contact uri $var(contact_uri) associated with media server $var(prefered_route)");
        route(DISPATCHER_REORDER_ROUTES);
    }
}

route[DISPATCHER_REORDER_ROUTES] 
{
    $var(i) = 0;
    $var(found) = 0;
    while($(avp(ds_dst)[$var(i)]) != $null) {
        if($(avp(ds_dst)[$var(i)]) != $var(prefered_route)) {
            $avp(tmp_ds_dst) = $(avp(ds_dst)[$var(i)]);
        } else {
            $var(found) = 1;
        }

        $var(i) = $var(i) + 1;
    }
   
    if ($var(found)) {
        xlog("L_INFO", "$ci|log|re-ordering the dispatcher list to keep associated server first");

        $(avp(ds_dst)[*]) = $null;

        $var(i) = 0;
        while($(avp(tmp_ds_dst)[$var(i)]) != $null) {
            $avp(ds_dst) = $(avp(tmp_ds_dst)[$var(i)]);

            $var(i) = $var(i) + 1;
        }
        $avp(ds_dst) = $var(prefered_route);
        $du = $var(prefered_route);

        $(avp(tmp_ds_dst)[*]) = $null;
    } else {
        xlog("L_INFO", "$ci|log|associated media server is inactive, moving to $rd");

        $sht(associations=>$var(association)) = $null;
    }
}

route[DISPATCHER_NEXT_ROUTE]
{
    $var(failover_count) = $sht(failover=>$ci::counts);

    if ($sht(failover=>$ci::counts) == $null) {
        $var(i) = 0;
        while($(avp(ds_dst)[$var(i)]) != $null) {
            $sht(failover=>$ci[$var(i)]) = $(avp(ds_dst)[$var(i)]);
            $var(i) = $var(i) + 1;
            if ($var(i) >= 3) {
                break;
            }
        }
        $sht(failover=>$ci::counts) = $var(i);
        $var(failover_count) = $var(i);
    }

    # try to find a new media server to send the call to
    if ($var(failover_count) > 1) {
        $var(failover_count) = $var(failover_count) - 1;

        $du = $sht(failover=>$ci[$var(failover_count)]);
        $sht(failover=>$ci::counts) = $var(failover_count);
        $sht(failover=>$ci::current) = $du;

        xlog("L_INFO", "$ci|log|remaining failed retry attempts: $var(failover_count)");
        xlog("L_INFO", "$ci|log|routing call to next media server $du");

        setflag(FLAG_SKIP_NAT_CORRECTION);

        # reset the final reply timer
        $avp(final_reply_timer) = 3;

        t_on_reply("INTERNAL_REPLY");

        t_on_failure("INTERNAL_FAULT");

        # relay the request to the new media server
        route(EXTERNAL_TO_INTERNAL_RELAY);

        exit();
    }
}

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