Class Socks5Server

src/main/java/org/example/Socks5Server.java:12–288

import java.nio.channels.SocketChannel;

public class Socks5Server {
    private static final byte SOCKS_VERSION = 0x05;
    private static final byte NO_AUTHENTICATION = 0x00;
    private static final byte CONNECT_COMMAND = 0x01;
    private static final byte IPV4_ADDRESS = 0x01;
    private static final byte DOMAIN_NAME = 0x03;
    private static final byte IPV6_ADDRESS = 0x04;

    private SocketWrapperBase<?> socketWrapper;
    private ByteBuffer readBuffer;
    private int peekPosition;

    public void handleClient(SocketChannel channel, SocketWrapperBase<?> wrapper) throws IOException {
        this.socketWrapper = wrapper;
        this.readBuffer = wrapper.getSocketBufferHandler().getReadBuffer();
        if (channel == null) {
            throw new IOException("不支持的socket类型");
        }

        try {
            // 处理认证方法协商
            if (!handleAuthenticationNegotiation(channel)) {
                return;
            }

            // 处理连接请求
            if (!handleConnectionRequest(channel)) {
                return;
            }

            // 开始转发数据
            handleDataTransfer(channel);
        } catch (Exception exception) {
            throw exception;
        } finally {
            try {
                channel.close();
            } catch (IOException e) {
                // 忽略关闭时的异常
            }
        }
    }

    private boolean handleAuthenticationNegotiation(SocketChannel channel) throws IOException {
        // 读取版本和方法数量
        ByteBuffer buffer = ByteBuffer.allocate(2);
        if (!peekRead(buffer, 2)) {
            return false;
        }
        buffer.flip();

        byte version = buffer.get();
        if (version != SOCKS_VERSION) {
            return false;
        }

        int numMethods = buffer.get() & 0xFF;