100多行PHP代码实现socks5代理服务器

100多行PHP代码实现socks5代理服务器，这次是使用swoole纯异步来写，使用状态机来处理数据。目前用它访问开源中国木有压力，但访问网易新闻就压力山大。我发现我用别的语言写得代理，访问网易新闻都压力大。嘎嘎，学艺不精。

对swoole理解不深，不知道怎么处理socket shutdown只关闭读/写这样，还有就是连接超时，读写超时这种怎么处理。在网上看到作者说要用定时器，感觉好麻烦，所以，这次的代理，虽然个人用，一般不会有什么问题，但离产品级的代理，还有段路要走。

如果要利用多核，就使用process模式，设置worker个数为cpu数量即可。

<?php
class Client
{
    public $connected = true;
    public $data = '';
    public $remote = null;
    public $status = 0;
}
class Server
{
    public $clients = [];
    public function start()
    {
        $server = new swoole_server('0.0.0.0', 8388, SWOOLE_BASE, SWOOLE_SOCK_TCP);
        $server->set([
            'max_conn' => 1000,
            'daemonize' => 1,
            'reactor_num' => 1,
            'worker_num' => 1,
            'dispatch_mode' => 2,
            'buffer_output_size' => 128 * 1024 * 1024,
            'open_cpu_affinity' => 1,
            'open_tcp_nodelay' => 1,
            'log_file' => 'socks5_server.log',
        ]);
        $server->on('connect', [$this, 'onConnect']);
        $server->on('receive', [$this, 'onReceive']);
        $server->on('close', [$this, 'onClose']);
        $server->start();
    }
    public function onConnect($server, $fd, $fromID)
    {
        $this->clients[$fd] = new Client();
    }
    public function onReceive($server, $fd, $fromID, $data)
    {
        ($this->clients[$fd])->data .= $data;
        $this->parse($server, $fd);
    }
    public function onClose($server, $fd, $fromID)
    {
        $client = $this->clients[$fd];
        $client->connected = false;
    }
    private function parse($server, $fd)
    {
        $client = $this->clients[$fd];

        switch ($client->status) {
            case 0: {
                if (strlen($client->data) >= 2) {
                    $request = unpack('c*', substr($client->data, 0, 2));
                    if ($request[1] !== 0x05) {
                        echo '协议不正确:' . $request[1], PHP_EOL;
                        $server->close($fd);
                        break;
                    }
                    $nmethods = $request[2];
                    if (strlen($client->data) >= 2 + $nmethods) {
                        $client->data = substr($client->data, 2 + $nmethods);
                        $server->send($fd, "\x05\x00");
                        $client->status = 1;
                    }
                }
            }
            case 1: {
                if (strlen($client->data) < 5)
                    break;
                $request = unpack('c*', $client->data);
                $aType = $request[4];
                if ($aType === 0x03) { // domain
                    $domainLen = $request[5];
                    if (strlen($client->data) < 5 + $domainLen + 2) {
                        break;
                    }
                    $domain = substr($client->data, 5, $domainLen);
                    $port = unpack('n', substr($client->data, 5 + $domainLen, 2))[1];
                    $client->data = substr($client->data, 5 + $domainLen + 2);
                } else if ($aType === 0x01) { // ipv4
                    $domain = long2ip(unpack('N', substr($client->data, 4, 4))[1]);
                    $port = unpack('n', substr($client->data, 8, 2))[1];
                    $client->data = substr($client->data, 10);
                } else {
                    echo '不支持的atype:' . $aType, PHP_EOL;
                    $server->close($fd);
                    break;
                }

                $remote = new swoole_client(SWOOLE_SOCK_TCP, SWOOLE_SOCK_ASYNC);
                $remote->on('connect', function($cli) use($client, $server, $fd, $remote) {
                    $server->send($fd, "\x05\x00\x00\x01\x00\x00\x00\x00\x00\x00");
                    $client->status = 2;
                    $client->remote = $remote;
                });
                $remote->on("error", function(swoole_client $cli) use($server, $fd) {
                    //$server->send($fd, ""); // todo 连接不上remote
                    echo 'connect to remote error.', PHP_EOL;
                    $server->close($fd);
                });
                $remote->on('receive', function($cli, $data) use($server, $fd, $client) {
                    if (!$client->connected) {
                        echo 'connection has been closed.', PHP_EOL;
                        return;
                    }
                    $server->send($fd, $data);
                });
                $remote->on('close', function($cli) use($server, $fd, $client) {
                    $client->remote = null;
                });
                if ($aType === 0x03) {
                    swoole_async_dns_lookup($domain, function($host, $ip) use($remote, $port, $server, $fd) {
                        //todo 当host为空时的处理。貌似不存在的域名都解析成了本机的外网ip，奇怪
                        if (empty($ip) || empty($host)) {
                            echo "host:{$host}, ip:{$ip}\n";
                            $server->close($fd);
                            return;
                        }
                        $remote->connect($ip, $port);
                    });
                } else {
                    $remote->connect($domain, $port);
                }
            }
            case 2: {
                if (strlen($client->data) === 0) {
                    break;
                }
                if ($client->remote === null) {
                    echo 'remote connection has been closed.', PHP_EOL;
                    break;
                }

                $sendByteCount = $client->remote->send($client->data);
                if ($sendByteCount === false || $sendByteCount < strlen($client->data)) {
                    echo 'data length:' , strlen($client->data), ' send byte count:', $sendByteCount, PHP_EOL;
                    echo $client->data, PHP_EOL;
                    $server->close($fd);
                }
                $client->data = '';
            }
        }
    }
}

(new Server())->start();