UDP hole puncher PoC

puncher.go

package main

import (
	"fmt"
	"net"
	"strconv"
	"time"
)

//ServerIP defines the IP and port of the other peer
const ServerIP string = "1.2.3.4:10001"

func main() {
	ServerAddr, err := net.ResolveUDPAddr("udp", ServerIP)
	if err != nil {
		fmt.Println(err)
	}

	LocalAddr, err := net.ResolveUDPAddr("udp", "0.0.0.0:10001")
	if err != nil {
		fmt.Println(err)
	}

	Conn, err := net.DialUDP("udp", LocalAddr, ServerAddr)
	if err != nil {
		fmt.Println(err)
	}

	defer Conn.Close()

	i := 0
	var recvbuf [1024]byte

	for {
		// Send data
		msg := strconv.Itoa(i)
		i++
		sendbuf := []byte(msg)
		_, err := Conn.Write(sendbuf)
		if err != nil {
			fmt.Println(err)
		}
		
		// Wait 1 second
		time.Sleep(time.Second * 1)
		
		// Receive data and print it on screen
		rlen, _, err := Conn.ReadFromUDP(recvbuf[:])
		if err != nil {
			fmt.Println(err)
		} else {
			fmt.Println(string(recvbuf[:rlen]))
		}
	}
}