Logger.php

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<?php

namespace SimpleSAML;

class Logger
{

    private static $loggingHandler = null;

    private static $logLevel = null;

    private static $captureLog = false;

    private static $capturedLog = array();

    private static $earlyLog = array();

    private static $logLevelStack = array();

    private static $logMask = 0;


    const NO_TRACKID = '_NOTRACKIDYET_';

    private static $trackid = self::NO_TRACKID;

    private static $format = '%date{%b %d %H:%M:%S} %process %level %stat[%trackid] %msg';

    private static $shutdownRegistered = false;

    private static $shuttingDown = false;

    const EMERG = 0;
    const ALERT = 1;
    const CRIT = 2;
    const ERR = 3;
    const WARNING = 4;
    const NOTICE = 5;
    const INFO = 6;
    const DEBUG = 7;


    public static function emergency($string)
    {
        self::log(self::EMERG, $string);
    }


    public static function critical($string)
    {
        self::log(self::CRIT, $string);
    }


    public static function alert($string)
    {
        self::log(self::ALERT, $string);
    }


    public static function error($string)
    {
        self::log(self::ERR, $string);
    }


    public static function warning($string)
    {
        self::log(self::WARNING, $string);
    }


    public static function notice($string)
    {
        self::log(self::NOTICE, $string);
    }


    public static function info($string)
    {
        self::log(self::INFO, $string);
    }


    public static function debug($string)
    {
        self::log(self::DEBUG, $string);
    }


    public static function stats($string)
    {
        self::log(self::NOTICE, $string, true);
    }


    public static function setCaptureLog($val = true)
    {
        self::$captureLog = $val;
    }


    public static function getCapturedLog()
    {
        return self::$capturedLog;
    }


    public static function setTrackId($trackId)
    {
        self::$trackid = $trackId;
    }


    public static function flush()
    {
        try {
            $s = \SimpleSAML_Session::getSessionFromRequest();
        } catch (\Exception $e) {
            // loading session failed. We don't care why, at this point we have a transient session, so we use that
            self::error('Cannot load or create session: '.$e->getMessage());
            $s = \SimpleSAML_Session::getSessionFromRequest();
        }
        self::$trackid = $s->getTrackID();

        self::$shuttingDown = true;
        foreach (self::$earlyLog as $msg) {
            self::log($msg['level'], $msg['string'], $msg['statsLog']);
        }
    }


    public static function isErrorMasked($errno)
    {
        return ($errno & self::$logMask) || !($errno & error_reporting());
    }


    public static function maskErrors($mask)
    {
        assert(is_int($mask));

        $currentEnabled = error_reporting();
        self::$logLevelStack[] = array($currentEnabled, self::$logMask);

        $currentEnabled &= ~$mask;
        error_reporting($currentEnabled);
        self::$logMask |= $mask;
    }


    public static function popErrorMask()
    {
        $lastMask = array_pop(self::$logLevelStack);
        error_reporting($lastMask[0]);
        self::$logMask = $lastMask[1];
    }


    private static function defer($level, $message, $stats)
    {
        // save the message for later
        self::$earlyLog[] = array('level' => $level, 'string' => $message, 'statsLog' => $stats);

        // register a shutdown handler if needed
        if (!self::$shutdownRegistered) {
            register_shutdown_function(array('SimpleSAML\Logger', 'flush'));
            self::$shutdownRegistered = true;
        }
    }


    private static function createLoggingHandler($handler = null)
    {
        // set to false to indicate that it is being initialized
        self::$loggingHandler = false;

        // a set of known logging handlers
        $known_handlers = array(
            'syslog'   => 'SimpleSAML\Logger\SyslogLoggingHandler',
            'file'     => 'SimpleSAML\Logger\FileLoggingHandler',
            'errorlog' => 'SimpleSAML\Logger\ErrorLogLoggingHandler',
        );

        // get the configuration
        $config = \SimpleSAML_Configuration::getInstance();
        assert($config instanceof \SimpleSAML_Configuration);

        // setting minimum log_level
        self::$logLevel = $config->getInteger('logging.level', self::INFO);

        // get the metadata handler option from the configuration
        if (is_null($handler)) {
            $handler = $config->getString('logging.handler', 'syslog');
        }

        if (!array_key_exists($handler, $known_handlers) && class_exists($handler)) {
            if (!in_array('SimpleSAML\Logger\LoggingHandlerInterface', class_implements($handler), true)) {
                throw new \Exception("The logging handler '$handler' is invalid.");
            }
        } else {
            $handler = strtolower($handler);
            if (!array_key_exists($handler, $known_handlers)) {
                throw new \Exception(
                    "Invalid value for the 'logging.handler' configuration option. Unknown handler '".$handler."''."
                );
            }
            $handler = $known_handlers[$handler];
        }
        self::$loggingHandler = new $handler($config);

        self::$format = $config->getString('logging.format', self::$format);
        self::$loggingHandler->setLogFormat(self::$format);
    }


    private static function log($level, $string, $statsLog = false)
    {
        if (self::$loggingHandler === false) {
            // some error occurred while initializing logging
            self::defer($level, $string, $statsLog);
            return;
        } elseif (php_sapi_name() === 'cli' || defined('STDIN')) {
            // we are being executed from the CLI, nowhere to log
            if (is_null(self::$loggingHandler)) {
                self::createLoggingHandler('SimpleSAML\Logger\StandardErrorLoggingHandler');
            }
            $_SERVER['REMOTE_ADDR'] = "CLI";
            if (self::$trackid === self::NO_TRACKID) {
                self::$trackid = 'CL'.bin2hex(openssl_random_pseudo_bytes(4));
            }
        } elseif (self::$loggingHandler === null) {
            // Initialize logging
            self::createLoggingHandler();

            if (!empty(self::$earlyLog)) {
                // output messages which were logged before we properly initialized logging
                foreach (self::$earlyLog as $msg) {
                    self::log($msg['level'], $msg['string'], $msg['statsLog']);
                }
            }
        }

        if (self::$captureLog) {
            $ts = microtime(true);
            $msecs = (int) (($ts - (int) $ts) * 1000);
            $ts = gmdate('H:i:s', $ts).sprintf('.%03d', $msecs).'Z';
            self::$capturedLog[] = $ts.' '.$string;
        }

        if (self::$logLevel >= $level || $statsLog) {
            if (is_array($string)) {
                $string = implode(",", $string);
            }

            $formats = array('%trackid', '%msg', '%srcip', '%stat');
            $replacements = array(self::$trackid, $string, $_SERVER['REMOTE_ADDR']);

            $stat = '';
            if ($statsLog) {
                $stat = 'STAT ';
            }
            array_push($replacements, $stat);

            if (self::$trackid === self::NO_TRACKID && !self::$shuttingDown) {
                // we have a log without track ID and we are not still shutting down, so defer logging
                self::defer($level, $string, $statsLog);
                return;
            } elseif (self::$trackid === self::NO_TRACKID) {
                // shutting down without a track ID, prettify it
                array_shift($replacements);
                array_unshift($replacements, 'N/A');
            }

            // we either have a track ID or we are shutting down, so just log the message
            $string = str_replace($formats, $replacements, self::$format);
            self::$loggingHandler->log($level, $string);
        }
    }
}