JavaNIO实现的内网穿透工具

package org.yuriey.fasttunnel.eventloop.server; import org.yuriey.fasttunnel.Bootstrap; import org.yuriey.fasttunnel.ServerBootstrap; import org.yuriey.fasttunnel.common.ChannelUtil; import org.yuriey.fasttunnel.common.Global; import org.yuriey.fasttunnel.config.Tunnel; import org.yuriey.fasttunnel.handler.ChannelHandler; import org.yuriey.fasttunnel.handler.server.FrontendServerChannelHandler; import java.io.IOException; import java.net.InetSocketAddress; import java.nio.ByteBuffer; import java.nio.channels.SelectionKey; import java.nio.channels.ServerSocketChannel; import java.nio.channels.SocketChannel; import java.util.Map; public class FrontendServerEventLoop extends ServerEventLoop { public FrontendServerEventLoop(Bootstrap bootstrap) { super(bootstrap); } @Override public Acceptor createAcceptor(ServerSocketChannel serverSocketChannel) { return new FrontendAcceptor(serverSocketChannel); } class FrontendAcceptor extends Acceptor { public FrontendAcceptor(ServerSocketChannel serverSocketChannel) { super(serverSocketChannel); } @Override protected ChannelHandler createChannelHandler(SocketChannel channel) { return new FrontendServerChannelHandler(bootstrap, FrontendServerEventLoop.this, channel); } @Override protected void postAccept(ServerSocketChannel serverSocketChannel, SocketChannel channel) { // 接收连接后，根据时间戳生成id，该id发送给客户端，当客户端和目标主机建立了连接， // 会同时与服务端建立隧道，并发送该id建立对应关系 Long id = System.currentTimeMillis(); Global.putFrontendChannel(id, channel); FrontendServerEventLoop.this.addOpenChannel(serverSocketChannel); FrontendServerEventLoop.this.addOpenChannel(channel); SelectionKey key = channel.keyFor(selector); if (key != null && key.isValid() && key.attachment() instanceof ChannelHandler handler) { ((FrontendServerChannelHandler) handler).setId(id); } //向Client写入连接请求 try { int port = ((InetSocketAddress) serverSocketChannel.getLocalAddress()).getPort(); if (!writeConnectRequest2Client(port, id)) { ChannelUtil.closeChannel(channel, FrontendServerEventLoop.this); } } catch (IOException e) { logger.error("connect request error."); } } private boolean writeConnectRequest2Client(int port, long id) throws IOException { // 根据监听的端口从配置文件找到对应的目标主机 Tunnel tunnel = Global.getTunnel(port); if (tunnel != null) { // port端口对应的目标主机 String destination = tunnel.getDestination(); // clientHost为转发数据的客户端 String clientHost = tunnel.getClientHost(); // 从在线的客户端列表中查找并匹配 for (Map.Entry<String, SocketChannel> e : Global.getClientSessions().entrySet()) { String host = e.getKey(); SocketChannel client = e.getValue(); if (host.equals(clientHost)) { String message = String.join(":", String.valueOf(id), destination); message = message.concat("#"); return ChannelUtil.interestWrite(client, ((ServerBootstrap) bootstrap).getServerEventLoop(), ByteBuffer.wrap(message.getBytes())); } } } return false; } } }