PHP 进行统一邮箱登陆的代理实现（swoole），

PHP 进行统一邮箱登陆的代理实现（swoole），

　　在工作的过程中，经常会有很多应用有发邮件的需求，这个时候需要在每个应用中配置smtp服务器。一旦公司调整了smtp服务器的配置，比如修改了密码等，这个时候对于维护的人员来说要逐一修改应用中smtp的配置。这样的情况虽然不多见，但遇上了还是很头痛的一件事情。

　　知道了问题，解决起来就有了方向。于是就有了自己开发一个简单的smtp代理的想法，这个代理主要的功能（参照问题）主要是：

　　　　1.接受指定IP应用的smtp请求；

　　　　2.应用不需要知道smtp的用户和密码；

　　　　3.转发应用的smtp请求。

　　开发的环境：Linux，php(swoole);

　　代码如下：

php
/**
 *
 * SMTP Proxy Server
 * @author Terry Zhang, 2015-11-13
 *
 * @version 1.0
 *
 * 注意：本程序只能运行在cli模式，且需要扩展Swoole 1.7.20+的支持。
 *
 * Swoole的源代码及安装请参考 https://github.com/swoole/swoole-src/
 *
 * 本程序的使用场景：
 * 
 * 在多个分散的系统中使用同一的邮件地址进行系统邮件发送时，一旦邮箱密码修改，则要修改每个系统的邮件配置参数。
 * 同时，在每个系统中配置邮箱参数，使得邮箱的密码容易外泄。
 * 
 * 通过本代理进行邮件发送的客户端，可以随便指定用户名和密码。
 * 
 * 
 */

//error_reporting(0);

defined('DEBUG_ON') or define('DEBUG_ON', false);

//主目录
defined('BASE_PATH') or define('BASE_PATH', __DIR__);

class CSmtpProxy{
    
    //软件版本
    const VERSION = '1.0';    
    
    const EOF = "\r\n";    
    
    public static $software = "SMTP-Proxy-Server";
    
    private static $server_mode = SWOOLE_PROCESS;    
    
    private static $pid_file;
    
    private static $log_file;
    
    private $smtp_host = 'localhost';
    
    private $smtp_port = 25;
    
    private $smtp_user = '';
    
    private $smtp_pass = '';
    
    private $smtp_from = '';
    
    //待写入文件的日志队列（缓冲区）
    private $queue = array();
    
    public $host = '0.0.0.0';
    
    public $port = 25;
    
    public $setting = array();
    
    //最大连接数
    public $max_connection = 50;
    

    /**
     * @var swoole_server
     */
    protected $server;
    
    protected $connection = array();
    
    public static function setPidFile($pid_file){
        self::$pid_file = $pid_file;
    }
    
    public static function start($startFunc){
        if(!extension_loaded('swoole')){
            exit("Require extension `swoole`.\n");
        }
        $pid_file = self::$pid_file;
        $server_pid = 0;
        if(is_file($pid_file)){
            $server_pid = file_get_contents($pid_file);
        }
        global $argv;
        if(empty($argv[1])){
            goto usage;
        }elseif($argv[1] == 'reload'){
            if (empty($server_pid)){
                exit("SMTP Proxy Server is not running\n");
            }
            posix_kill($server_pid, SIGUSR1);
            exit;
        }elseif ($argv[1] == 'stop'){
            if (empty($server_pid)){
                exit("SMTP Proxy is not running\n");
            }
            posix_kill($server_pid, SIGTERM);
            exit;
        }elseif ($argv[1] == 'start'){
            //已存在ServerPID，并且进程存在
            if (!empty($server_pid) and posix_kill($server_pid,(int) 0)){
                exit("SMTP Proxy is already running.\n");
            }
            //启动服务器
            $startFunc();
        }else{
            usage:
            exit("Usage: php {$argv[0]} start|stop|reload\n");
        }
    }
    
    public function __construct($host,$port){    
        $flag = SWOOLE_SOCK_TCP;
        $this->server = new swoole_server($host,$port,self::$server_mode,$flag);
        $this->host = $host;
        $this->port = $port;
        $this->setting = array(
                'backlog' => 128,
                'dispatch_mode' => 2,
        );
    }
    
    public function daemonize(){
        $this->setting['daemonize'] = 1;
    }
    
    public function getConnectionInfo($fd){
        return $this->server->connection_info($fd);
    }
    
    /**
     * 启动服务进程
     * @param array $setting
     * @throws Exception
     */
    public function run($setting = array()){
        $this->setting = array_merge($this->setting,$setting);
        //不使用swoole的默认日志
        if(isset($this->setting['log_file'])){
            self::$log_file = $this->setting['log_file'];
            unset($this->setting['log_file']);
        }
        if(isset($this->setting['max_connection'])){
            $this->max_connection = $this->setting['max_connection'];
            unset($this->setting['max_connection']);
        }
        if(isset($this->setting['smtp_host'])){
            $this->smtp_host = $this->setting['smtp_host'];
            unset($this->setting['smtp_host']);
        }
        if(isset($this->setting['smtp_port'])){
            $this->smtp_port = $this->setting['smtp_port'];
            unset($this->setting['smtp_port']);
        }
        if(isset($this->setting['smtp_user'])){
            $this->smtp_user = $this->setting['smtp_user'];
            unset($this->setting['smtp_user']);
        }
        if(isset($this->setting['smtp_pass'])){
            $this->smtp_pass = $this->setting['smtp_pass'];
            unset($this->setting['smtp_pass']);
        }
        if(isset($this->setting['smtp_from'])){
            $this->smtp_from = $this->setting['smtp_from'];
            unset($this->setting['smtp_from']);
        }
    
        $this->server->set($this->setting);
        $version = explode('.', SWOOLE_VERSION);
        if($version[0] == 1 && $version[1] $version