ZP-765 Logging system now uses instance instead of static files. Released...

ZP-765 Logging system now uses instance instead of static files. Released under the Affero GNU General Public License (AGPL) version 3.

config.php

+/etc/kronos/z-push/config.php
\ No newline at end of file

src/config.php

@@ -98,6 +98,8 @@
     define('LOGERRORFILE', LOGFILEDIR . 'z-push-error.log');
     define('LOGLEVEL', LOGLEVEL_WBXML);
     define('LOGAUTHFAIL', false);
+    // Either filelog or syslog or a custom log class in core/log/logclass
+    define('LOGBACKEND', 'filelog');
 
 
     // To save e.g. WBXML data only for selected users, add the usernames to the array
@@ -107,14 +109,14 @@
     define('LOGUSERLEVEL', LOGLEVEL_DEVICEID);
     $specialLogUsers = array();
 
-    // If you want to disable log to file, and log to syslog instead
-    define('LOG_SYSLOG_ENABLED', false);
     // false will log to local syslog, otherwise put the remote syslog IP here
     define('LOG_SYSLOG_HOST', false);
     // Syslog port
     define('LOG_SYSLOG_PORT', 514);
     // Program showed in the syslog. Useful if you have more than one instance login to the same syslog
-    define('LOG_SYSLOG_PROGRAM', '[z-push]');
+    define('LOG_SYSLOG_PROGRAM', 'z-push');
+    // Syslog facility
+    define('LOG_SYSLOG_FACILITY', LOG_LOCAL0);
 
 
     // Location of the trusted CA, e.g. '/etc/ssl/certs/EmailCA.pem'

src/include/z_syslog.php

-<?php
-/*
- * Copyright 2015 Leon van Kammen / Coder of Salvation. All rights reserved.
- * Modifications 2015 - Francisco Miguel Biete
- *
- * Redistribution and use in source and binary forms, with or without modification, are
- * permitted provided that the following conditions are met:
- *
- *    1. Redistributions of source code must retain the above copyright notice, this list of
- *       conditions and the following disclaimer.
- *
- *    2. Redistributions in binary form must reproduce the above copyright notice, this list
- *       of conditions and the following disclaimer in the documentation and/or other materials
- *       provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY Leon van Kammen / Coder of Salvation AS IS'' AND ANY EXPRESS OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
- * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL Leon van Kammen / Coder of Salvation OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
- * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
- * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
- * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
- * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * The views and conclusions contained in the software and documentation are those of the
- * authors and should not be interpreted as representing official policies, either expressed
- * or implied, of Leon van Kammen / Coder of Salvation
- *
- * https://github.com/coderofsalvation/syslog-flexible
- */
-
-class ZSyslog {
-    private static $hostname   = false;
-    private static $port       = 514;
-    private static $program    = "[z-push]";
-
-    /**
-     * Initializes the logging
-     *
-     * @access public
-     * @return boolean
-     */
-    public static function Initialize() {
-        if (defined('LOG_SYSLOG_HOST'))
-            self::$hostname = LOG_SYSLOG_HOST;
-        if (defined('LOG_SYSLOG_PORT'))
-            self::$port = LOG_SYSLOG_PORT;
-        if (defined('LOG_SYSLOG_PROGRAM'))
-            self::$program = LOG_SYSLOG_PROGRAM;
-    }
-
-    /**
-     * Send a message in the syslog facility.
-     *
-     * @params int      $zlog_level     Z-Push LogLevel
-     * @params string   $message
-     *
-     * @access public
-     * @return boolean
-     */
-    public static function send($zlog_level, $message) {
-        $level = self::zlogLevel2SyslogLevel($zlog_level);
-        if ($level === false) {
-            return false;
-        }
-
-        if (self::$hostname === false) {
-            return syslog($level, $message);
-        }
-        else {
-            $sock = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
-            $facility = 1; // user level
-            $pri = ($facility*8) + $level; // multiplying the Facility number by 8 + adding the level
-            foreach (explode("\n", $message) as $line) {
-                if (strlen(trim($line)) > 0) {
-                    $syslog_message = "<{$pri}>" . date('M d H:i:s ') . self::$program . ': ' . $line;
-                    socket_sendto($sock, $syslog_message, strlen($syslog_message), 0, self::$hostname, self::$port);
-                }
-            }
-            socket_close($sock);
-        }
-
-        return true;
-    }
-
-    /**
-     * Converts the ZLog level to SYSLOG level.
-     *
-     * @params int      $loglevel     Z-Push LogLevel
-     *
-     * @access private
-     * @return SYSLOG_LEVEL or false
-     */
-    private static function zlogLevel2SyslogLevel($loglevel) {
-        switch($loglevel) {
-            case LOGLEVEL_OFF:   return false; break;
-            case LOGLEVEL_FATAL: return LOG_ALERT; break;
-            case LOGLEVEL_ERROR: return LOG_ERR; break;
-            case LOGLEVEL_WARN:  return LOG_WARNING; break;
-            case LOGLEVEL_INFO:  return LOG_INFO; break;
-            case LOGLEVEL_DEBUG: return LOG_DEBUG; break;
-            case LOGLEVEL_WBXML: return LOG_DEBUG; break;
-            case LOGLEVEL_DEVICEID: return LOG_DEBUG; break;
-            case LOGLEVEL_WBXMLSTACK: return LOG_DEBUG; break;
-        }
-    }
-}

src/index.php

@@ -69,8 +69,10 @@ include_once('lib/core/asdevice.php');
 include_once('lib/core/statemanager.php');
 include_once('lib/core/devicemanager.php');
 include_once('lib/core/zpush.php');
-include_once('include/z_syslog.php');
 include_once('lib/core/zlog.php');
+include_once('lib/log/log.php');
+include_once('lib/log/filelog.php');
+include_once('lib/log/syslog.php');
 include_once('lib/interface/ibackend.php');
 include_once('lib/interface/ichanges.php');
 include_once('lib/interface/iexportchanges.php');

src/lib/core/zlog.php

@@ -42,15 +42,19 @@
 ************************************************/
 
 class ZLog {
-    static private $devid = '';
-    static private $user = '';
+    static private $devid = ''; //done
+    static private $user = ''; // done
     static private $authUser = false;
-    static private $pidstr;
+    static private $pidstr; //done
     static private $wbxmlDebug = '';
     static private $lastLogs = array();
     static private $userLog = false;
     static private $unAuthCache = array();
     static private $syslogEnabled = false;
+    /**
+     * @var Log $logger
+     */
+    static private $logger = null;
 
     /**
      * Initializes the logging
@@ -59,12 +63,7 @@ class ZLog {
      * @return boolean
      */
     static public function Initialize() {
-        global $specialLogUsers;
-
-        if (defined('LOG_SYSLOG_ENABLED') && LOG_SYSLOG_ENABLED) {
-            self::$syslogEnabled = true;
-            ZSyslog::Initialize();
-        }
+        $logger = self::getLogger();
 
         // define some constants for the logging
         if (!defined('LOGUSERLEVEL'))
@@ -73,27 +72,14 @@ class ZLog {
         if (!defined('LOGLEVEL'))
             define('LOGLEVEL', LOGLEVEL_OFF);
 
-        list($user,) = Utils::SplitDomainUser(strtolower(Request::GetGETUser()));
-        self::$userLog = in_array($user, $specialLogUsers);
-        if (!defined('WBXML_DEBUG') && $user) {
+        if (!defined('WBXML_DEBUG')) {
             // define the WBXML_DEBUG mode on user basis depending on the configurations
-            if (LOGLEVEL >= LOGLEVEL_WBXML || (LOGUSERLEVEL >= LOGLEVEL_WBXML && self::$userLog))
+            if (LOGLEVEL >= LOGLEVEL_WBXML || (LOGUSERLEVEL >= LOGLEVEL_WBXML && $logger->HasSpecialLogUsers()))
                 define('WBXML_DEBUG', true);
             else
                 define('WBXML_DEBUG', false);
         }
 
-        if ($user)
-            self::$user = '['. $user .'] ';
-        else
-            self::$user = '';
-
-        // log the device id if the global loglevel is set to log devid or the user is in  and has the right log level
-        if (Request::GetDeviceID() != "" && (LOGLEVEL >= LOGLEVEL_DEVICEID || (LOGUSERLEVEL >= LOGLEVEL_DEVICEID && self::$userLog)))
-            self::$devid = '['. Request::GetDeviceID() .'] ';
-        else
-            self::$devid = '';
-
         return true;
     }
 
@@ -114,35 +100,13 @@ class ZLog {
             $message = substr($message, 0, 10240) . sprintf(" <log message with %d bytes truncated>", $messagesize);
 
         self::$lastLogs[$loglevel] = $message;
-        $data = self::buildLogString($loglevel) . $message . "\n";
-
-        if ($loglevel <= LOGLEVEL) {
-            self::writeToLog($loglevel, $data, LOGFILE);
-        }
 
-        // should we write this into the user log?
-        if ($loglevel <= LOGUSERLEVEL && self::$userLog) {
-            // padd level for better reading
-            $data = str_replace(self::getLogLevelString($loglevel), self::getLogLevelString($loglevel,true), $data);
-
-            // is the user authenticated?
-            if (self::logToUserFile()) {
-                // something was logged before the user was authenticated, write this to the log
-                if (!empty(self::$unAuthCache)) {
-                    self::writeToLog($loglevel, implode('', self::$unAuthCache), LOGFILEDIR . self::logToUserFile() . ".log");
-                    self::$unAuthCache = array();
-                }
-                // only use plain old a-z characters for the generic log file
-                self::writeToLog($loglevel, $data, LOGFILEDIR . self::logToUserFile() . ".log");
-            }
-            // the user is not authenticated yet, we save the log into memory for now
-            else {
-                self::$unAuthCache[] = $data;
-            }
+        try{
+            self::getLogger()->Log($loglevel, $message);
         }
-
-        if (($loglevel & LOGLEVEL_FATAL) || ($loglevel & LOGLEVEL_ERROR)) {
-            self::writeToLog($loglevel, $data, LOGERRORFILE);
+        catch(\Exception $e) {
+            //@TODO How should we handle logging error ?
+            // Ignore any error.
         }
 
         if ($loglevel & LOGLEVEL_WBXMLSTACK) {
@@ -193,101 +157,35 @@ class ZLog {
         }
     }
 
-    /**----------------------------------------------------------------------------------------------------------
-     * private log stuff
-     */
-
     /**
-     * Returns the filename logs for a WBXML debug log user should be saved to
+     * Returns the logger object. If no logger has been initialized, FileLog will be initialized and returned.
      *
      * @access private
-     * @return string
+     * @return Log
+     * @throws Exception thrown if the logger class cannot be instantiated.
      */
-    static private function logToUserFile() {
-        global $specialLogUsers;
-
-        if (self::$authUser === false) {
-            if (RequestProcessor::isUserAuthenticated()) {
-                $authuser = Request::GetAuthUser();
-                if ($authuser && in_array($authuser, $specialLogUsers))
-                    self::$authUser = preg_replace('/[^a-z0-9]/', '_', strtolower($authuser));
-            }
+    static private function getLogger() {
+        if (!self::$logger) {
+            global $specialLogUsers; // This variable comes from the configuration file (config.php)
+            $logger = LOGBACKEND;
+            if (!class_exists($logger)) {
+                throw new \Exception('The class `'.$logger.'` does not exist.');
             }
-        return self::$authUser;
-    }
-
-    /**
-     * Returns the string to be logged
-     *
-     * @access private
-     * @return string
-     */
-    static private function buildLogString($loglevel) {
-        if (!isset(self::$pidstr))
-            self::$pidstr = '[' . str_pad(@getmypid(),5," ",STR_PAD_LEFT) . '] ';
 
-        if (!isset(self::$user))
-            self::$user = '';
+            $user = '['.Utils::SplitDomainUser(strtolower(Request::GetGETUser()))[0].']';
 
-        if (!isset(self::$devid))
-            self::$devid = '';
-
-        if (self::$syslogEnabled)
-            return self::$pidstr . self::getLogLevelString($loglevel, (LOGLEVEL > LOGLEVEL_INFO)) . " " . self::$user . self::$devid;
-        else
-            return Utils::GetFormattedTime() . " " . self::$pidstr . self::getLogLevelString($loglevel, (LOGLEVEL > LOGLEVEL_INFO)) . " " . self::$user . self::$devid;
-    }
-
-    /**
-     * Returns the string representation of the LOGLEVEL.
-     * String can be padded
-     *
-     * @param int       $loglevel           one of the LOGLEVELs
-     * @param boolean   $pad
-     *
-     * @access private
-     * @return string
-     */
-    static private function getLogLevelString($loglevel, $pad = false) {
-        if ($pad) $s = " ";
-        else      $s = "";
-        switch($loglevel) {
-            case LOGLEVEL_OFF:   return ""; break;
-            case LOGLEVEL_FATAL: return "[FATAL]"; break;
-            case LOGLEVEL_ERROR: return "[ERROR]"; break;
-            case LOGLEVEL_WARN:  return "[".$s."WARN]"; break;
-            case LOGLEVEL_INFO:  return "[".$s."INFO]"; break;
-            case LOGLEVEL_DEBUG: return "[DEBUG]"; break;
-            case LOGLEVEL_WBXML: return "[WBXML]"; break;
-            case LOGLEVEL_DEVICEID: return "[DEVICEID]"; break;
-            case LOGLEVEL_WBXMLSTACK: return "[WBXMLSTACK]"; break;
+            self::$logger = new $logger();
+            self::$logger->SetUser($user);
+            self::$logger->SetSpecialLogUsers($specialLogUsers);
+            self::$logger->SetDevid('['. Request::GetDeviceID() .']');
+            self::$logger->SetPidstr('[' . str_pad(@getmypid(),5," ",STR_PAD_LEFT) . ']');
         }
+        return self::$logger;
     }
 
-    /**
-     * Write the message to the log facility.
-     *
-     * @param int       $loglevel
-     * @param string    $data
-     * @param string    $logfile
-     *
-     * @access private
-     * @return void
+    /**----------------------------------------------------------------------------------------------------------
+     * private log stuff
      */
-    static private function writeToLog($loglevel, $data, $logfile = null) {
-        if (self::$syslogEnabled) {
-            if (ZSyslog::send($loglevel, $data) === false) {
-                error_log("Unable to send to syslog");
-                error_log($data);
-            }
-        }
-        else {
-            if (@file_put_contents($logfile, $data, FILE_APPEND) === false) {
-                error_log(sprintf("Unable to write in %s", $logfile));
-                error_log($data);
-            }
-        }
-    }
 }
 
 /**----------------------------------------------------------------------------------------------------------

src/lib/core/zpush.php

@@ -220,6 +220,31 @@ class ZPush {
         else
             define('REAL_BASE_PATH', BASE_PATH);
 
+        if(!defined('LOGBACKEND')){
+            define('LOGBACKEND', 'filelog');
+        }
+
+        if(LOGBACKEND == 'syslog') {
+            if(!defined('LOG_SYSLOG_FACILITY')) {
+                define('LOG_SYSLOG_FACILITY', LOG_LOCAL0);
+            }
+            if(!defined('LOG_SYSLOG_HOST')){
+                define('LOG_SYSLOG_HOST', false);
+            }
+            if(!defined('LOG_SYSLOG_PORT')){
+                define('LOG_SYSLOG_PORT', 514);
+            }
+            if(!defined('LOG_SYSLOG_PROGRAM')){
+                define('LOG_SYSLOG_PROGRAM', 'z-push');
+            }
+            if(!is_numeric(LOG_SYSLOG_PORT)){
+                throw new FatalMisconfigurationException("The LOG_SYSLOG_PORT must a be a number.");
+            }
+            if(LOG_SYSLOG_HOST && LOG_SYSLOG_PORT <= 0){
+                throw new FatalMisconfigurationException("LOG_SYSLOG_HOST is defined but the LOG_SYSLOG_PORT does not seem to be valid.");
+            }
+        }
+        elseif(LOGBACKEND == 'filelog'){
             if (!defined('LOGFILEDIR'))
                 throw new FatalMisconfigurationException("The LOGFILEDIR is not configured. Check if the config.php file is in place.");
 
@@ -238,6 +263,7 @@ class ZPush {
             // check ownership on the (eventually) just created files
             Utils::FixFileOwner(LOGFILE);
             Utils::FixFileOwner(LOGERRORFILE);
+        }
 
         // set time zone
         // code contributed by Robert Scheck (rsc) - more information: https://developer.berlios.de/mantis/view.php?id=479

src/lib/log/filelog.php

+<?php
+class FileLog extends Log{
+
+    /**
+     * @var string|bool
+     */
+    private $log_to_user_file = false;
+
+    /**
+     * Get the log user file. If the parameter is false, it tries to generate it.
+     *
+     * @access private
+     * @return string|bool False if the log user file is not set and could not be generated otherwise string.
+     */
+    private function getLogToUserFile() {
+        if ($this->log_to_user_file === false) {
+            $this->setLogToUserFile(preg_replace('/[^a-z0-9]/', '_', strtolower(Request::GetAuthUser())) . '.log');
+        }
+        return $this->log_to_user_file;
+    }
+
+    /**
+     * @param string $value
+     */
+    private function setLogToUserFile($value) {
+        $this->log_to_user_file = $value;
+    }
+
+    public function __construct(){}
+
+    /**
+     * Returns the string to be logged
+     *
+     * @param int $loglevel
+     * @param string $message
+     *
+     * @access public
+     * @return string
+     */
+    public function BuildLogString($loglevel, $message) {
+        $log = Utils::GetFormattedTime() . $this->GetPidstr() . $this->GetLogLevelString($loglevel, $loglevel >= LOGLEVEL_INFO) .' '. $this->GetUser();
+        if ($loglevel >= LOGLEVEL_DEVICEID) {
+            $log .= $this->GetDevid();
+        }
+        $log .= ' ' . $message;
+        return $log;
+    }
+
+    //
+    // Implementation of Log
+    //
+
+    protected function Write($loglevel, $message){
+        $data = $this->buildLogString($loglevel, $message) . "\n";
+        @file_put_contents(LOGFILE, $data, FILE_APPEND);
+
+        if (($loglevel & LOGLEVEL_FATAL) || ($loglevel & LOGLEVEL_ERROR)) {
+            @file_put_contents(LOGERRORFILE, $data, FILE_APPEND);
+        }
+    }
+
+    public function WriteForUser($loglevel, $message){
+        $data = $this->buildLogString($loglevel, $message) . "\n";
+        @file_put_contents(LOGFILEDIR . $this->getLogToUserFile(), $data, FILE_APPEND);
+    }
+
+    protected function afterLog($loglevel, $message){
+      if (($loglevel & LOGLEVEL_FATAL) || ($loglevel & LOGLEVEL_ERROR)) {
+        $data = $this->buildLogString($loglevel, $message) . "\n";
+        @file_put_contents(LOGERRORFILE, $data, FILE_APPEND);
+      }
+    }
+}

src/lib/log/log.php

+<?php
+abstract class Log{
+
+    /**
+     * @var string
+     */
+    protected $user = '';
+    /**
+     * @var string
+     */
+    protected $devid = '';
+
+    /**
+     * @var string
+     */
+    protected $pidstr = '';
+
+    /**
+     * @var array
+     */
+    protected $specialLogUsers = array();
+
+    /**
+     * @var array
+     */
+    private $unauthMessageCache = array();
+
+    /**
+     * @access public
+     * @return string
+     */
+    public function GetUser() {
+        return $this->user;
+    }
+    /**
+     * @param string$value
+     *
+     * @access public
+     */
+    public function SetUser($value) {
+        $this->user = $value;
+    }
+
+    /**
+     * @access public
+     * @return string
+     */
+    public function GetDevid() {
+        return $this->devid;
+    }
+    /**
+     * @param string $value
+     *
+     * @access public
+     */
+    public function SetDevid($value) {
+        $this->devid = $value;
+    }
+
+    /**
+     * @access public
+     * @return string
+     */
+    public function GetPidstr() {
+        return $this->pidstr;
+    }
+    /**
+     * @param string $value
+     *
+     * @access public
+     */
+    public function SetPidstr($value) {
+        $this->pidstr = $value;
+    }
+
+    /**
+     * @access public
+     * @return bool True if we do have to log some specific user. False otherwise.
+     */
+    public function HasSpecialLogUsers() {
+        return !empty($this->specialLogUsers);
+    }
+
+    /**
+     * @param string $user
+     *
+     * @acces public
+     * @return bool
+     */
+    public function IsUserInSpecialLogUsers($user) {
+        if ($this->HasSpecialLogUsers()) {
+            return in_array($user, $this->GetSpecialLogUsers());
+        }
+        return false;
+    }
+    /**
+     * @access public
+     * @return array
+     */
+    public function GetSpecialLogUsers() {
+        return $this->specialLogUsers;
+    }
+    /**
+     * @param array $value
+     *
+     * @access public
+     */
+    public function SetSpecialLogUsers(array $value) {
+        $this->specialLogUsers = $value;
+    }
+
+    public function __construct() {}
+
+    /**
+     * @param int $loglevel
+     * @param string $message
+     */
+    public function Log($loglevel, $message) {
+        if ($loglevel <= LOGLEVEL) {
+            $this->Write($loglevel, $message);
+        }
+        if ($loglevel <= LOGUSERLEVEL && $this->HasSpecialLogUsers()) {
+            if(RequestProcessor::isUserAuthenticated() && $this->IsUserInSpecialLogUsers(Request::GetAuthUser())) {
+                // something was logged before the user was authenticated, write this to the log
+                if (!empty($this->unauthMessageCache)) {
+                    foreach ($this->unauthMessageCache as $authcache) {
+                        $this->WriteForUser($authcache[0], $authcache[1]);
+                    }
+                    self::$unAuthCache = array();
+                }
+                $this->WriteForUser($loglevel, $message);
+            }
+            else {
+                $this->unauthMessageCache[] = [$loglevel, $message];
+            }
+        }
+
+        $this->afterLog($loglevel, $message);
+    }
+
+    /**
+     * This function is used as an event for log implementer.
+     */
+    protected function afterLog($loglevel, $message) {}
+
+    /**
+     * Returns the string representation of the given $loglevel.
+     * String can be padded
+     *
+     * @param int             $loglevel                     one of the LOGLEVELs
+     * @param boolean     $pad
+     *
+     * @access protected
+     * @return string
+     */
+    protected function GetLogLevelString($loglevel, $pad = false) {
+        if ($pad) $s = " ";
+        else            $s = "";
+        switch($loglevel) {
+            case LOGLEVEL_OFF:     return ""; break;
+            case LOGLEVEL_FATAL: return "[FATAL]"; break;
+            case LOGLEVEL_ERROR: return "[ERROR]"; break;
+            case LOGLEVEL_WARN:    return "[".$s."WARN]"; break;
+            case LOGLEVEL_INFO:    return "[".$s."INFO]"; break;
+            case LOGLEVEL_DEBUG: return "[DEBUG]"; break;
+            case LOGLEVEL_WBXML: return "[WBXML]"; break;
+            case LOGLEVEL_DEVICEID: return "[DEVICEID]"; break;
+            case LOGLEVEL_WBXMLSTACK: return "[WBXMLSTACK]"; break;
+        }
+    }
+
+    /**
+     * @param int $loglevel
+     * @param string $message
+     *
+     * @access public
+     * @return null
+     */
+    abstract protected function Write($loglevel, $message);
+
+    /**
+     * @param int $loglevel
+     * @param string $message
+     *
+     * @access public
+     * @return null
+     */
+    abstract public function WriteForUser($loglevel, $message);
+}
\ No newline at end of file

src/lib/log/syslog.php

+<?php
+class Syslog extends Log{
+
+    protected $program_name = '';
+
+    protected $host;
+
+    protected $port;
+
+    /**
+     * @access public
+     * @return string
+     */
+    public function GetProgramName() {
+        return $this->program_name;
+    }
+    /**
+     * @param string $value
+     *
+     * @access public
+     */
+    public function SetProgramName($value) {
+        $this->program_name = $value;
+    }
+
+    /**
+     * @access public
+     * @return string
+     */
+    public function GetHost() {
+        return $this->host;
+    }
+    /**
+     * @param string $value
+     *
+     * @access public
+     */
+    public function SetHost($value) {
+        $this->host = $value;
+    }
+
+    /**
+     * @access public
+     * @return int
+     */
+    public function GetPort() {
+        return $this->port;
+    }
+    /**
+     * @param int $value
+     *
+     * @access public
+     */
+    public function SetPort($value) {
+        if (is_numeric($value)) {
+            $this->port = (int)$value;
+        }
+    }
+
+    public function __construct($program_name = null, $host = null, $port = null) {
+        parent::__construct();
+
+        if(is_null($program_name)) $program_name = LOG_SYSLOG_PROGRAM;
+        if(is_null($host)) $host = LOG_SYSLOG_HOST;
+        if(is_null($port)) $port = LOG_SYSLOG_PORT;
+
+        $this->SetProgramName($program_name);
+        $this->SetHost($host);
+        $this->SetPort($port);
+    }
+
+    /**
+     * Return the full program name for syslog.
+     * The name can be z-push/core or z-push/{backend} where backend is the backend that initiated the log.
+     *
+     * @access protected
+     * @return string
+     */
+    protected function GenerateProgramName() {
+
+        // @TODO Use another mechanism than debug_backtrace to determine to origin of the log
+        $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
+        // Shift the "syslog.php" entry.
+        array_shift($backtrace);
+        foreach($backtrace as $trace) {
+            if (!isset($trace['file'])) {
+                continue;
+            }
+            if (strpos($trace['file'], REAL_BASE_PATH . 'backend/') !== false) {
+                preg_match('/\/backend\/([a-zA-Z]*)/', $trace['file'], $match);
+                if (isset($match[1])) {
+                    return $this->GetProgramName().'/'.$match[1];
+                }
+            }
+            elseif (basename($trace['file'], '.php') != 'zlog') {
+                return $this->GetProgramName().'/core';
+            }
+        }
+
+        return $this->GetProgramName().'/core';
+    }
+
+    /**
+     * Maps the z-push loglevel with those of syslog.
+     *
+     * @access protected
+     * @param int $loglevel
+     * @return int One of many LOG_* syslog level.
+     */
+    protected function GetZpushLogLevelToSyslogLogLevel($loglevel) {
+        switch($loglevel) {
+                case LOGLEVEL_FATAL: return LOG_ALERT; break;
+                case LOGLEVEL_ERROR: return LOG_ERR; break;
+                case LOGLEVEL_WARN:    return LOG_WARNING; break;
+                case LOGLEVEL_INFO:    return LOG_INFO; break;
+                case LOGLEVEL_DEBUG: return LOG_DEBUG; break;
+                case LOGLEVEL_WBXML: return LOG_DEBUG; break;
+                case LOGLEVEL_DEVICEID: return LOG_DEBUG; break;
+                case LOGLEVEL_WBXMLSTACK: return LOG_DEBUG; break;
+        }
+        return null;
+    }
+
+    /**
+     * Build the log string for syslog.
+     *
+     * @param int $loglevel
+     * @param string $message
+     *
+     * @access public
+     * @return string
+     */
+    public function BuildLogString($loglevel, $message) {
+        $log = $this->GetLogLevelString($loglevel); // Never pad syslog log because syslog log are usually read with a software.
+        $log .= $this->GetUser();
+        if($loglevel >= LOGLEVEL_DEVICEID) {
+            $log .= $this->GetDevid();
+        }
+        $log .= ' ' . $message;
+        return $log;
+    }
+
+
+    //
+    // Implementation of Log
+    //
+
+    protected function Write($loglevel, $message) {
+        if ($this->GetHost() && $this->GetPort()) {
+            $sock = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
+            $facility = 1; // user level
+            $pri = ($facility*8) + $loglevel; // multiplying the Facility number by 8 + adding the level
+            $data = $this->buildLogString($loglevel, $message);
+            if (strlen(trim($data)) > 0) {
+                $syslog_message = "<{$pri}>" . date('M d H:i:s ') . '['.$this->GetProgramName() . ']: ' . $data;
+                socket_sendto($sock, $syslog_message, strlen($syslog_message), 0, $this->GetHost(), $this->GetPort());
+            }
+            socket_close($sock);
+        }
+        else {
+            openlog($this->GenerateProgramName(), LOG_PID, LOG_SYSLOG_FACILITY);
+            syslog(
+                $this->GetZpushLogLevelToSyslogLogLevel($loglevel),
+                $this->buildLogString($loglevel, $message)
+            );
+        }
+    }
+
+    public function WriteForUser($loglevel, $message) {
+        $this->Write(LOGLEVEL_DEBUG, $message); // Always pass the logleveldebug so it uses syslog level LOG_DEBUG
+    }
+}
\ No newline at end of file