function already_connected (in /etc/inc/captiveportal.inc)

function already_connected($sessionid)
{
    global $g, $config, $cpzone;
    if ($sessionid != "")   {
        $query = "WHERE sessionid = '{$sessionid}'";
        $cpdb = captiveportal_read_db($query);
        foreach ($cpdb as $cpentry) {
            if ($cpentry[5] == $sessionid) {
                captiveportal_logportalauth($cpentry[4], $sessionid, $cpentry[2], "Found sessionid");
                return true;
            }
        }
    }
    return false;
}