xjasonlyu/tun2socks

//go:build linux && !(amd64 || arm64)

package tun

import (
    "fmt"
    "os"

    "golang.zx2c4.com/wireguard/tun"
    gun "gvisor.dev/gvisor/pkg/tcpip/link/tun"
)

const (
    offset     = 0 /* IFF_NO_PI */
    defaultMTU = 1500
)

func createTUN(name string, mtu int) (tun.Device, error) {
    nfd, err := gun.Open(name)
    if err != nil {
        return nil, fmt.Errorf("create tun: %w", err)
    }

    fd := os.NewFile(uintptr(nfd), "/dev/net/tun")
    return tun.CreateTUNFromFile(fd, mtu)
}