Go Program with User-Space TCP Stack and TUN Adapter
This article explains how to write a Go program that utilizes a user-space TCP stack to establish a connection with a remote server and writes to a TUN adapter (wintun.dll). The program specifies the TUN device IP (e.g., 192.168...).
Prerequisites
Before diving into the Go program, ensure you have the following prerequisites:
- Go programming language: Download and install Go from official Go download page.
- wintun.dll: Download the TUN adapter driver for Windows from WinTun GitHub releases.
Go Program
Create a new Go file (e.g., main.go) and paste the following code:
package main
import (
"fmt"
"net"
"os"
"syscall"
)
func main() {
// Set TUN device IP (e.g., 192.168.1.1)
const tunDeviceIP = "192.168.1.1"
// Open TUN device
tunFD, err := syscall.Syscall(syscall.SYS_OPEN, uintptr(os.Argv[1]), syscall.O_RDWR, 0)
if err != 0 {
fmt.Println("Error opening TUN device:", err)
return
}
defer syscall.Syscall(syscall.SYS_CLOSE, tunFD)
// Set TUN device IP
ipAddr := net.ParseIP(tunDeviceIP)
err = syscall.SetsockoptInt(tunFD, syscall.SOL_SOCKET, syscall.SO_BINDTODEVICE, 1)
if err != nil {
fmt.Println("Error setting TUN device IP:", err)
return
}
err = syscall.SetsockoptIPv4Addr(tunFD, syscall.SOL_SOCKET, syscall.SO_BINDTODEVICE, &syscall.SockaddrIn4{Addr: ipAddr, Port: 0})
if err != nil {
fmt.Println("Error setting TUN device IP:", err)
return
}
// Create TCP connection to remote server
conn, err := net.Dial("tcp", "remote_server:port")
if err != nil {
fmt.Println("Error connecting to remote server:", err)
return
}
defer conn.Close()
// Write data to TCP connection and TUN device
data := []byte("Hello, World!")
_, err = conn.Write(data)
if err != nil {
fmt.Println("Error writing to TCP connection:", err)
return
}
_, err = syscall.Write(tunFD, data)
if err != nil {
fmt.Println("Error writing to TUN device:", err)
return
}
fmt.Println("Data sent successfully.")
}
Running the Program
To run the program, execute the following command:
go run main.go
References
- Go programming language: Go official website
- WinTun TUN adapter: WinTun GitHub repository