simple tcp proxy implement for experiment #php

proxy.php

	/**
	 * @param $lPort 本地端口
	 * @param $rHost 远程主机
	 * @param $rPort 远程端口
	 */
	function actionProxy2($lPort, $rHost, $rPort)
	{
		$recvTimeoutSec = 5;
		$localServer = stream_socket_server("tcp://0.0.0.0:$lPort", $lErrno, $lErrstr);
		if ($localServer === FALSE)
		{
			die('TSocket: Could not connect to 0.0.0.0:'.$lPort.' ('.$lErrstr.' ['.$lErrno.'])');
		}
		else
		{
			echo "Local connect succ...\n";
		}
		//stream_set_blocking($rHandle, false);
		stream_set_blocking($localServer, false);

		$handles = ['local' => $localServer];
		$localToRemoteMap = [];//本地连接和远程连接的mapping
		$localConns = [];//本地连接
		while (true)
		{
			$read = $handles;
			$readable = @stream_select($read,  $_w = NULL, $_e = NULL, 5);
			if ($readable > 0)
			{
				foreach ($read as $item)
				{
					echo "reading...\n";
					$key = array_search($item, $handles);
					if ($key === 'local')
					{
						echo "Accept new connection\n";
						$currentLocalConn = stream_socket_accept($localServer);
						$rHandle = stream_socket_client("tcp://$rHost:$rPort", $errno, $errstr, $recvTimeoutSec);
						if ($rHandle === FALSE)
						{
							echo 'TSocket: Could not connect to '.$rHost.':'.$rPort.' ('.$errstr.' ['.$errno.'])' . "\n";
							@stream_socket_shutdown($currentLocalConn, STREAM_SHUT_RDWR);
							continue;
						}

						$handles[$currentLocalConn] = $currentLocalConn;
						$handles[$rHandle] = $rHandle;
						$localToRemoteMap[$currentLocalConn] = $rHandle;
						$localConns[$currentLocalConn] = $currentLocalConn;
					}
					elseif (isset($localToRemoteMap[$item]))
					{
						$data = @stream_socket_recvfrom($item, 1500);
						if (strlen($data) == 0)
						{
							closeConn($item, $localToRemoteMap[$item], $localToRemoteMap, $localConns, $handles);
						}
						else
						{
							echo "Receive data from local and send to remote: $data\n";
							@stream_socket_sendto($localToRemoteMap[$item], $data);
							//@fwrite($proxyMapping[$item], $data);
						}
					}
					elseif (($localConnId = array_search($item, $localToRemoteMap)) !== false)
					{
						$data = @stream_socket_recvfrom($item, 1500);
						if (strlen($data) == 0)
						{
							$this->closeConn($localConns[$localConnId], $item, $localToRemoteMap, $localConns, $handles);
						}
						else
						{
							echo "Receive data from remote and send to local: $data\n";
							//@stream_socket_sendto($index, $data);
							@fwrite($localConns[$localConnId], $data);
						}
					}
					else
					{
						echo "Error!\n";
						@stream_socket_shutdown($item, STREAM_SHUT_RDWR);
						unset($handles[$item]);
					}
				}
			}
			else
			{
				echo "No readable\n";
			}
		}
	}

	function closeConn($local, $remote, &$localToRemoteMap, &$localConns, &$handles)
	{
		@stream_socket_shutdown($remote, STREAM_SHUT_RDWR);//close remote
		@stream_socket_shutdown($local, STREAM_SHUT_RDWR);//close mapping local
		if(isset($localToRemoteMap[$local])) unset($localToRemoteMap[$local]);//remove local to remote mapping
		if(isset($localConns[$local])) unset($localConns[$local]);//remove local from local conns
		if(isset($handles[$remote])) unset($handles[$remote]);//remove remote from event loop
		if(isset($handles[$local])) unset($handles[$local]);//remove local from event loop
	}