Interfacing with TUN\TAP for MAC OSX (Lion) using Python

Question

I found the following tun\\tap example program and can not get it to work:

http://www.secdev.org/projects/tuntap_udp/files/tunproxy.py

I have modified the fo

Answer 1

The OSX tun/tap driver seems to work a bit different. The Linux example dynamically allocates a tun interface, which does not work in OSX, at least not in the same way.

I stripped the code to create a basic example of how tun can be used on OSX using a self-selected tun device, printing each packet to the console. I added Scapy as a dependency for pretty printing, but you can replace it by a raw packet dump if you want:

import os, sys
from select import select
from scapy.all import IP

f = os.open("/dev/tun12", os.O_RDWR)
try:
    while 1:
        r = select([f],[],[])[0][0]
        if r == f:
            packet = os.read(f, 4000)
            # print len(packet), packet
            ip = IP(packet)
            ip.show()
except KeyboardInterrupt:
    print "Stopped by user."

You will either have to run this as root, or do a sudo chown your_username /dev/tun12 to be allowed to open the device.

To configure it as a point-to-point interface, type:

$ sudo ifconfig tun12 10.12.0.2 10.12.0.1

Note that the tun12 interface will only be available while /dev/tun12 is open, i.e. while the program is running. If you interrupt the program, your tun interface will disappear, and you will need to configure it again next time you run the program.

If you now ping your endpoint, your packets will be printed to the console:

$ ping 10.12.0.1

Ping itself will print request timeouts, because there is no tunnel endpoint responding to your ping requests.

Answer 2

so about the 'No such file or directory' error when doing:

f = os.open("/dev/tun12", os.O_RDWR)

this worked for me:

brew install Caskroom/cask/tuntap