前兩天在B站上看到一個小伙紙100元組裝個電腦打LOL畫質流暢,突發奇想100行代碼能(簡單)實現個啥好玩的。我主要是做php開發的,於是就有了本文。
當然,由於php(不算swoole擴展)本身不擅長做網絡服務端編程,所以這個代理,只是個玩具,離日常使用有點距離。如果想使用穩定可靠的加密(所以能禾斗學上網)代理,可以用這個:https://github.com/momaer/asocks-go也是100來行代碼使用go實現。
寫的過程中發現php多線程還是難的。比如我開始想每個連接新建一個線程。但這個線程得保存起來(比如保存到數組),比如官方例子中的這個:https://github.com/krakjoe/pthreads/blob/master/examples/SocketServer.php 要放到$clients這個數組裡,不然,你試試(curl -L一個要301的地址)就知道出現什麼情況了。
這個例子說了in the real world, do something here to ensure clients not running are destroyed 但是,如何把不再運行的連接銷毀卻沒有講。恩。我試了把$clients放到一個類裡,把類傳給線程類,然後在線程類要結束時把$clients裡對應的連接給unset掉,無果。
那,以下就是使用線程池來實現的代理,按道理講,退出時池要shutdown(),監聽socket也要shutdown的,但百行代碼,就不勉強了,隨著ctrl + c,就讓操作系統來回收資源吧。
php不擅長網絡編程體現在哪裡呢?首先我用的是stream_socket_XXX相關的函數,為啥不用socket擴展呢?因為socket擴展有問題,參見:https://github.com/krakjoe/pthreads/issues/581 而stream_set_timeout對stream_socket_recvfrom這些高級操作,不起作用,參見:http://php.net/manual/en/function.stream-set-timeout.php 而這些,在寫代理時都需要考慮的。比如連接遠程目標服務器時,沒有超時控制,很容易就線程池跑滿了。
測試的話,使用curl即可,對了,目前只支持遠程dns解析,為啥呢?因為這個玩具後期可是要實現禾斗學上網的喲: 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 '協議不正確.', 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($this->fd, STREAM_SHUT_RDWR); echo '請使用遠程dns解析.', PHP_EOL; } stream_socket_sendto($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)); }