这是一个简单的Fullcone网络打洞脚本，用于测试FullCone网络内网穿透的理论可行性

client.js

const http = require('http');
const localPort = 18000; //这是本地即将暴露的端口
const endpoint_url = '' //这是部署了server.js的服务器的ip地址
const endpoint_port = 13000 //这是部署了server.js的服务器的端口
const req = http.request({
    host: endpoint_url,
    port: endpoint_port,
    method: 'GET',
    localPort: localPort
}, (res) => {
    res.on('data', (data) => {
        const { ip, port } = JSON.parse(data.toString());
        console.log(`127.0.0.1:${localPort} -> ${ip}:${port}`);
        console.log(`http://${ip}:${port}`);
        http.createServer((req, res) => {
            console.log(`Request from ${req.connection.remoteAddress}`);
            res.writeHead(200, { 'Content-Type': 'text/plain' });
            res.end(`Working at ${new Date()}`);
        }).listen(localPort); //通过server.js探测到映射对，然后在本地启动一个服务器，外网访问ip:port会被映射到本地的localPort，从而实现了内网穿透
    })
});
req.end();

server.js

const http = require('http');
const server = http.createServer((req, res) => {
  res.writeHead(200, { 'Content-Type': 'application/json' });
  const ip = req.connection.remoteAddress.match(/\d+\.\d+\.\d+\.\d+/)[0];
  const port = req.connection.remotePort;
  console.log(`Request from ${ip}:${port}`);
  setInterval(() => {
    try {
      const req = http.request({
        host: ip,
        port: port,
        method: 'GET'
      })
      req.end();
    } catch (e) { }
  }, 1000); //该定时器会每秒向客户端发送一个请求，使得映射关系不会因为长时间没有通信而被销毁，从而实现锁定映射关系
  res.end(JSON.stringify({ ip, port }));
}).listen(13000);