montag451 / ltun

Linux TUN/TAP module for Lua

Linux TUN/TAP module for Lua

ltun is a Lua module which let you create TUN/TAP device very easily.

License: MIT (see LICENSE)

Dependencies

Lua >= 5.1

Compilation

To compile, just type the following command in the terminal:

make

If you are on a debian-like system and you have installed all the required dependencies, it should work as-is. If you are out of luck, you can tweak the compilation process using the following variables:

• LUA_VERSION
• LUA_CFLAGS

For example, say that you want to compile ltun for Lua 5.1 (by default ltun is compiled for Lua 5.2) you can try:

make LUA_VERSION=5.1

Or for LuaJIT:

make LUA_VERSION=jit

If the Lua development headers are not in a common location, you can try:

make LUA_CFLAGS="-I/path/to/lua/headers"

Documentation

NOTE: On most distributions you will need to be root to create TUN/TAP devices.

To create a TUN device:

local ltun = require('ltun')

local tun = ltun.create()

To create a TAP device:

local ltun = require('ltun')

local tap = ltun.create(ltun.IFF_TAP)

To create a TUN/TAP device with a custom name:

local tun = ltun.create('mytun')

To specify additional flags:

local tun = ltun.create('mytun', ltun.IFF_TUN, ltun.IFF_NO_PI)

Or just:

local tun = ltun.create(ltun.IFF_TUN, ltun.IFF_NO_PI)

You can get/set some parameters of the device directly:

print(tun.name)
tun.addr = '10.8.0.1'
tun.dstaddr = '10.8.0.2'
tun.netmask = '255.255.255.0'
tun.mtu = 1500

If the device is a TAP you can also get/set its MAC address:

tap.hwaddr = '\x00\x11\x22\x33\x44\x55'
print(tap.hwaddr)

To make the device persistent:

tun:persist(true)

To bring up the device:

tun:up()

To bring down the device:

tun:down()

To read/write to the device, use the methods read(size) and write(buf):

buf = tun:read(tun.mtu)
tun:write(buf)

To close the device:

tun:close()

You can also get the file descriptor associated with a TUN/TAP device:

tun:fileno()