A simply pthon script to create a tunnel interface.

create_tun.py

#!/usr/bin/env python3

import fcntl
import struct
import os
from scapy.layers.inet import IP
from warnings import warn
from dataclasses import dataclass, field
from typing import List
import subprocess


@dataclass
class apData:
    IFNAMSIZ: int = 16
    IFF_TUN: int = 0x0001
    IFF_TAP: int = 0x0002  # Should we want to tunnel layer 2...
    IFF_NO_PI: int = 0x1000
    TUNSETIFF: int = 0x400454ca
    DEVICE: str = "tun0"
    IP_ADDRESS: str = "10.1.1.1"
    NETMASK: str = "255.255.255.0"
    IP_NETWORK: str = "10.1.1"
    NET_BROADCAST: str = "10.1.1.255"


def create_tun():
    name = "rogue1"
    if len(name) > apData.IFNAMSIZ:
        raise Exception(
            "Tun interface name it too big"
        )
    fd = open('/dev/net/tun', 'r+b')
    ifr_flags = apData.IFF_TUN | apData.IFF_NO_PI
    ifreq = struct.pack('16sH', name, ifr_flags)
    fcntl.ioctl(fd, apData.TUNSETIFF, ifreq)
    if subprocess.call(['ip', 'addr', 'add', apData.IP_ADDRESS, 'dev', apData.DEVICE]):
        warn("Failed to assign ip address to dev")
    if subprocess.call(['ip', 'link', 'set', 'dev', apData.DEVICE, 'up']):
        warn("failed to bring device up")


if __name__ == "create_tun.py":
    create_tun()