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] < 7 && $version[2] <20){
            throw new Exception('Swoole version require 1.7.20 +.');
        }
        //事件绑定
        $this->server->on('start',array($this,'onMasterStart'));
        $this->server->on('shutdown',array($this,'onMasterStop'));
        $this->server->on('ManagerStart',array($this,'onManagerStart'));
        $this->server->on('ManagerStop',array($this,'onManagerStop'));
        $this->server->on('WorkerStart',array($this,'onWorkerStart'));
        $this->server->on('WorkerStop',array($this,'onWorkerStop'));
        $this->server->on('WorkerError',array($this,'onWorkerError'));
        $this->server->on('Connect',array($this,'onConnect'));
        $this->server->on('Receive',array($this,'onReceive'));
        $this->server->on('Close',array($this,'onClose'));

        $this->server->start();
    }

    public function log($msg,$level = 'debug',$flush = false){
        if(DEBUG_ON){
            $log = date('Y-m-d H:i:s').' ['.$level."]\t" .$msg."\n";
            if(!empty(self::$log_file)){
                $debug_file = dirname(self::$log_file).'/debug.log';
                file_put_contents($debug_file, $log,FILE_APPEND);
                if(filesize($debug_file) > 10485760){//10M
                    unlink($debug_file);
                }
            }
            echo $log;
        }
        if($level != 'debug'){
            //日志记录
            $this->queue[] = date('Y-m-d H:i:s')."\t[".$level."]\t".$msg;
        }
        if(count($this->queue)>10 && !empty(self::$log_file) || $flush){
            if (filesize(self::$log_file) > 209715200){ //200M
                rename(self::$log_file,self::$log_file.'.'.date('His'));
            }
            $logs = '';
            foreach ($this->queue as $q){
                $logs .= $q."\n";
            }
            file_put_contents(self::$log_file, $logs,FILE_APPEND);
            $this->queue = array();
        }
    }

    public function shutdown(){
        return $this->server->shutdown();
    }

    public function close($fd){
        return $this->server->close($fd);
    }

    public function send($fd,$data){
        $data = strtr($data,array("\n" => "", "\0" => "", "\r" => ""));
        $this->log("[P --> C]\t" . $data);
        return $this->server->send($fd,$data.self::EOF);
    }

    /*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
     + 事件回调
    +++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/

    public function onMasterStart($serv){
        global $argv;
        swoole_set_process_name('php '.$argv[0].': master -host='.$this->host.' -port='.$this->port);
        if(!empty($this->setting['pid_file'])){
            file_put_contents(self::$pid_file, $serv->master_pid);
        }
        $this->log('Master started.');
    }

    public function onMasterStop($serv){
        if (!empty($this->setting['pid_file'])){
            unlink(self::$pid_file);
        }
        $this->shm->delete();
        $this->log('Master stop.');
    }

    public function onManagerStart($serv){
        global $argv;
        swoole_set_process_name('php '.$argv[0].': manager');
        $this->log('Manager started.');
    }

    public function onManagerStop($serv){
        $this->log('Manager stop.');
    }

    public function onWorkerStart($serv,$worker_id){
        global $argv;
        if($worker_id >= $serv->setting['worker_num']) {
            swoole_set_process_name("php {$argv[0]}: worker [task]");
        } else {
            swoole_set_process_name("php {$argv[0]}: worker [{$worker_id}]");
        }
        $this->log("Worker {$worker_id} started.");
    }

    public function onWorkerStop($serv,$worker_id){
        $this->log("Worker {$worker_id} stop.");
    }

    public function onWorkerError($serv,$worker_id,$worker_pid,$exit_code){
        $this->log("Worker {$worker_id} error:{$exit_code}.");
    }

    public function onConnect($serv,$fd,$from_id){
        if(count($this->server->connections) <= $this->max_connection){
            $info = $this->getConnectionInfo($fd);
            if($this->isIpAllow($info['remote_ip'])){
                //建立服务器连接
                $cli = new Client(SWOOLE_SOCK_TCP, SWOOLE_SOCK_ASYNC); //异步非阻塞
                $cli->on('connect',array($this,'onServerConnect'));
                $cli->on('receive',array($this,'onServerReceive'));
                $cli->on('error',array($this,'onServerError'));
                $cli->on('close',array($this,'onServerClose'));
                $cli->fd = $fd;
                $ip = gethostbyname($this->smtp_host);
                if($cli->connect($ip,$this->smtp_port) !== false){
                    $this->connection[$fd] = $cli;
                }else{
                    $this->close($fd);
                    $this->log('Cannot connect to SMTP server. Connection #'.$fd.' close.');
                }
            }else{
                $this->log('Blocked clinet connection, IP deny : '.$info['remote_ip'],'warn');
                $this->server->close($fd);
                $this->log('Connection #'.$fd.' close.');
            }
        }else{
            $this->log('Blocked clinet connection, too many connections.','warn');
            $this->server->close($fd);
        }
    }

    public function onReceive($serv,$fd,$from_id,$recv_data){
        $info = $this->getConnectionInfo($fd);
        $this->log("[P <-- C]\t".trim($recv_data));
        //禁止使用STARTTLS
        if(strtoupper(trim($recv_data)) == 'STARTTLS'){
            $this->server->send($fd,"502 Not implemented".self::EOF);
            $this->log("[P --> C]\t502 Not implemented");
        }else{

            //重置登陆验证
            if(preg_match('/^AUTH\s+LOGIN(.*)/', $recv_data,$m)){
                $m[1] = trim($m[1]);
                if(empty($m[1])){
                    //只发送AUTH LOGIN 接下来将发送用户名
                    $this->connection[$fd]->user = $this->smtp_user;
                }else{
                    $recv_data = 'AUTH LOGIN '.base64_encode($this->smtp_user).self::EOF;
                    $this->connection[$fd]->pass = $this->smtp_pass;
                }
            }else{
                //if(preg_match('/^HELO.*|^EHLO.*/', $recv_data)){
                //    $recv_data = 'HELO '.$this->smtp_host.self::EOF;
                //}
                //重置密码
                if(!empty($this->connection[$fd]->pass)){
                    $recv_data = base64_encode($this->connection[$fd]->pass).self::EOF;
                    $this->connection[$fd]->pass = '';
                }
                //重置用户名
                if(!empty($this->connection[$fd]->user)){
                    $recv_data = base64_encode($this->connection[$fd]->user).self::EOF;
                    $this->connection[$fd]->user = '';
                    $this->connection[$fd]->pass = $this->smtp_pass;
                }

                //重置mail from
                if(preg_match('/^MAIL\s+FROM:.*/', $recv_data)){
                    $recv_data = 'MAIL FROM:<'.$this->smtp_from.'>'.self::EOF;
                }
            }

            if($this->connection[$fd]->isConnected()){
                $this->connection[$fd]->send($recv_data);
                $this->log("[P --> S]\t".trim($recv_data));
            }
        }

    }

    public function onClose($serv,$fd,$from_id){
        if(isset($this->connection[$fd])){
            if($this->connection[$fd]->isConnected()){
                $this->connection[$fd]->close();
                $this->log('Connection on SMTP server close.');
            }
        }
        $this->log('Connection #'.$fd.' close. Flush the logs.','debug',true);
    }

    /*---------------------------------------------
     *
     * 服务器连接事件回调
     *
     ----------------------------------------------*/

    public function onServerConnect($cli){
        $this->log('Connected to SMTP server.');
    }

    public function onServerReceive($cli,$data){
        $this->log("[P <-- S]\t".trim($data));
        if($this->server->send($cli->fd,$data)){
            $this->log("[P --> C]\t".trim($data));
        }
    }

    public function onServerError($cli){
        $this->server->close($cli->fd);
        $this->log('Connection on SMTP server error: '.$cli->errCode.' '.socket_strerror($cli->errCode),'warn');
    }

    public function onServerClose($cli){
        $this->log('Connection on SMTP server close.');
        $this->server->close($cli->fd);
    }

    /**
     * IP地址过滤
     * @param unknown $ip
     * @return boolean
     */
    public function isIpAllow($ip){
        $pass = false;
        if(isset($this->setting['ip']['allow'])){
            foreach ($this->setting['ip']['allow'] as $addr){
                $pattern = '/'.str_replace('*','\d+',str_replace('.', '\.', $addr)).'/';
                if(preg_match($pattern, $ip) && !empty($addr)){
                    $pass = true;
                    break;
                }
            }
        }
        if($pass){
            if(isset($this->setting['ip']['deny'])){
                foreach ($this->setting['ip']['deny'] as $addr){
                    $pattern = '/'.str_replace('*','\d+',str_replace('.', '\.', $addr)).'/';
                    if(preg_match($pattern, $ip) && !empty($addr)){
                        $pass = false;
                        break;
                    }
                }
            }
        }
        return $pass;
    }

}

class Client extends swoole_client{
    /**
     * 记录当前连接
     * @var unknown
     */
    public $fd ;

    public $user = '';

    /**
     * smtp登陆密码
     * @var unknown
     */
    public $pass = '';
}

　　配置文件例子：

　　

/**
 *  运行配置
*/
return array(
        'worker_num' => 12,
        'log_file' => BASE_PATH.'/logs/proxyserver.log',
        'pid_file' => BASE_PATH.'/logs/proxyserver.pid',
        'heartbeat_idle_time' => 300,
        'heartbeat_check_interval' => 60,
        'max_connection' => 50,   
　　　　　//配置真实的smtp信息
        'smtp_host' => '',
        'smtp_port' => 25,
        'smtp_user' => '',
        'smtp_pass' => '',
        'smtp_from' => '',
        'ip' => array(
            'allow' => array('192.168.0.*'),
            'deny' => array('192.168.10.*','192.168.100.*'),
        )
);

　　运行例子：

　　

defined('BASE_PATH') or define('BASE_PATH', __DIR__);
defined('DEBUG_ON') or define('DEBUG_ON', true);
//服务器配置
require BASE_PATH.'/CSmtpProxy.php';

$settings = require BASE_PATH.'/conf/config.php';

CSmtpProxy::setPidFile($settings['pid_file']);

CSmtpProxy::start(function(){
	global $settings;
	$serv = new CSmtpProxy('0.0.0.0', 25);
	$serv->daemonize();
	$serv->run($settings);
});

　　应用配置：

　　smtp host: 192.168.0.*  //指定smtpproxy 运行的服务器IP。

　　　　　port: 25

　　　　　user: xxxx  //随意填写

　　　　　pass:  xxxx  //随意填写

　　　　　from: xxxx@xxxx.com // 根据情况填写

——————————————————————————————————————————————————————

　　存在的问题：

　　　　1、不支持ssl模式；

　　　　2、应用的from还是要填写正确，否则发出的邮件发件人会显示错误。