100 lines of PHP code to implement socks5 proxy server, 100 lines of socks5

100 lines of PHP code to implement socks5 proxy server, 100 lines of socks5_PHP tutorial

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Release： 2016-07-12 08:53:01

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100 lines of PHP code to implement socks5 proxy server, 100 lines of socks5

Two days ago, I saw a guy on station B asking for 100 yuan to assemble a computer to play LOL with smooth picture quality. I suddenly thought about something interesting that I could achieve (simplely) with 100 lines of code. I mainly do PHP development, so I have this article.

Of course, since PHP (not counting swoole extension) itself is not good at network server programming, this agent is just a toy and is a bit far away from daily use. If you want to use a stable and reliable encryption (so you can learn to surf the Internet) proxy, you can use this: https://github.com/momaer/asocks-go is also 100 lines of code and implemented using go.

During the writing process, I found that PHP multi-threading is still difficult. For example, I started thinking about creating a new thread for each connection. But this thread must be saved (for example, saved to an array), such as this one in the official example: https://github.com/krakjoe/pthreads/blob/master/examples/SocketServer.php should be placed $clients array, otherwise, you can try (curl -L an address that requires 301) and you will know what happens.

This example says that in the real world, do something here to ensure clients not running are destroyed. However, it does not talk about how to destroy connections that are no longer running. kindness. I tried putting $clients into a class, passing the class to the thread class, and then unsetting the corresponding connection in $clients when the thread class was about to end, to no avail.

Then, the following is a proxy implemented using a thread pool. Logically speaking, the pool needs to be shut down() when exiting, and the monitoring socket must also be shut down. But with hundreds of lines of code, there is no need to force it. With ctrl c, it Let the operating system reclaim resources.

Why is PHP not good at network programming? First of all, I used the stream_socket_XXX related functions. Why not use socket extension? Because there is a problem with the socket extension, see: https://github.com/krakjoe/pthreads/issues/581 And stream_set_timeout does not work for advanced operations such as stream_socket_recvfrom, see: http://php.net /manual/en/function.stream-set-timeout.php These need to be considered when writing a proxy. For example, when connecting to a remote target server, there is no timeout control, and the thread pool can easily become full.

For testing, just use curl. By the way, currently only remote dns resolution is supported. Why? Because this toy will later enable Hedou to learn to access the Internet: curl --socks5-hostname 127.0.0.1:1080 http://ip.cn

Class Pipe extends Threaded
{
  private $client;
  private $remote;
  public function __construct($client, $remote) 
  {
    $this->client = $client;
    $this->remote = $remote; 
  }
  public function run()
  {
    for ( ; ; ) {
        $data = stream_socket_recvfrom($this->client, 4096);
        if ($data === false || strlen($data) === 0) {
          break;
        } 
        $sendBytes = stream_socket_sendto($this->remote, $data);
        if ($sendBytes <= 0) {
          break;
        }
    }
    stream_socket_shutdown($this->client, STREAM_SHUT_RD);
    stream_socket_shutdown($this->remote, STREAM_SHUT_WR);
  }
}

Class Client extends Threaded
{
  public $fd;
  public function __construct($fd)
  {
    $this->fd = $fd; 
  }

  public function run()
  {
    $data = stream_socket_recvfrom($this->fd, 2);
    $data = unpack('c*', $data);
    if ($data[1] !== 0x05) {
      stream_socket_shutdown($this->fd, STREAM_SHUT_RDWR);
      echo '协议不正确.', PHP_EOL;
      return;
    }
    $nmethods = $data[2];
    $data = stream_socket_recvfrom($this->fd, $nmethods);
    stream_socket_sendto($this->fd, "\x05\x00");
    $data = stream_socket_recvfrom($this->fd, 4);
    $data = unpack('c*', $data);
    $addressType = $data[4];
    if ($addressType === 0x03) { // domain
      $domainLength = unpack('c', stream_socket_recvfrom($this->fd, 1))[1];
      $data = stream_socket_recvfrom($this->fd, $domainLength + 2);
      $domain = substr($data, 0, $domainLength);
      $port = unpack("n", substr($data, -2))[1];
    } else {
      stream_socket_shutdown($this->fd, STREAM_SHUT_RDWR);
      echo '请使用远程dns解析.', PHP_EOL;
    }

    stream_socket_sendto($this->fd, "\x05\x00\x00\x01\x00\x00\x00\x00\x00\x00");
    echo "{$domain}:{$port}", PHP_EOL;
    $remote = stream_socket_client("tcp://{$domain}:{$port}");
    if ($remote === false) {
      stream_socket_shutdown($this->fd, STREAM_SHUT_RDWR);
      return;
    }

    $pool = $this->worker->pipePool;

    $pipe1 = new Pipe($remote, $this->fd);
    $pipe2 = new Pipe($this->fd, $remote);

    $pool->submit($pipe1);
    $pool->submit($pipe2);
  }
}

class ProxyWorker extends Worker
{
  public $pipePool;
  public function __construct($pipePool)
  {
    $this->pipePool = $pipePool;
  }
}

$server = stream_socket_server('tcp://0.0.0.0:1080', $errno, $errstr);
if ($server === false)
  exit($errstr);

$pipePool = new Pool(200, Worker::class);
$pool = new Pool(50, 'ProxyWorker', [$pipePool]);

for( ; ; ) {
  $fd = @stream_socket_accept($server, 60);
  if ($fd === false)
    continue;
  $pool->submit(new Client($fd));
}

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