Shadowsocks-workerman-php UDP support added

原来workerman 实现的 shadowsocks 服务器仅支持 TCP，不支持 UDP，这样导致无法直接兼容 OUTLINE 客户端，网上找了一些资料，主要参考了 swoole-ss 这方面的实现，最终实现了 UDP 支持，顺便兼容 OUTLINE。

以下为修改 server.php 的内容

1. 增加 UDP 监听

// 初始化worker，监听$PORT端口
$worker = new Worker('tcp://0.0.0.0:'.$PORT);
 $worker2 = new Worker('udp://0.0.0.0:'.$PORT);
 // 进程数量
$worker->count = $PROCESS_COUNT;
$worker2->count=$worker->count = $PROCESS_COUNT;
// 名称
$worker->name = 'shadowsocks-server';
$worker2->name=$worker->name = 'shadowsocks-server';

// UDP support
$worker2->onMessage=function($connection, $buffer)use($METHOD, $PASSWORD)
{
    if (is_null(@$connection->encryptor)){
        $connection->encryptor = new Encryptor($PASSWORD, $METHOD);
    }
    $buffer = $connection->encryptor->decrypt($buffer);
    // 解析socket5头
    $header_data = parse_socket5_header2($buffer);
    // 头部长度
    $header_len = $header_data[3];
    $host = $header_data[1];
    $port = $header_data[2];
    $address = "udp://$host:$port";
    //echo $address."\n";
    
    $remote_connection = new AsyncUdpConnection($address);
    @$remote_connection->source=$connection;
    $remote_connection->onConnect=function ($remote_connection)use ($buffer,$header_len){
        $remote_connection->send(substr($buffer,$header_len));
    };
    $remote_connection->onMessage=function ($remote_connection,$buffer)use($header_data){
        $_header = pack_header($header_data[1],$header_data[0],$header_data[2]);
        $_data = $remote_connection->source->encryptor->encrypt($_header.$buffer);
        $remote_connection->source->send($_data);
    };
    $remote_connection->connect();
    
};

/*
 UDP 部分 返回客户端 头部数据 by @Zac
 //生成UDP header 它这里给返回解析出来的域名貌似给udp dns域名解析用的
*/
function pack_header($addr,$addr_type,$port){
    $header = '';
    //$ip = pack('N',ip2long($addr));
    //判断是否是合法的公共IPv4地址，192.168.1.1这类的私有IP地址将会排除在外
    /*
     if(filter_var($addr, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4 | FILTER_FLAG_NO_PRIV_RANGE)) {
     // it's valid
     $addr_type = ADDRTYPE_IPV4;
     //判断是否是合法的IPv6地址
     }elseif(filter_var($addr, FILTER_VALIDATE_IP, FILTER_FLAG_NO_RES_RANGE)){
     $addr_type = ADDRTYPE_IPV6;
     }
     */
    switch ($addr_type) {
        case ADDRTYPE_IPV4:
            $header = b"\x01".inet_pton($addr);
            break;
        case ADDRTYPE_IPV6:
            $header = b"\x04".inet_pton($addr);
            break;
        case ADDRTYPE_HOST:
            if(strlen($addr)>255){
                $addr = substr($addr,0,255);
            }
            $header =  b"\x03".chr(strlen($addr)).$addr;
            break;
        default:
            return;
    }
    return $header.pack('n',$port);
}

项目代码： https://github.com/firzen/shadowsocks-php

参考：
https://github.com/walkor/shadowsocks-php
https://github.com/shadowsocksBak/shadowsocks-php