This repository is unmaintained: You should use the more comprehensive and well maintained water library.

TUN/TAP

NOTE: This package is new and should be considered unstable, in terms of both API and function.

tuntap is a native wrapper for interfacing with TUN/TAP network devices in an idiomatic fashion.

Currently supported are Linux and Mac OS X.

go get github.com/jamescun/tuntap

Configuration

The configuration required to open a TUN/TAP device varies by platform. The differences are noted below.

Linux

When creating a TUN/TAP device, Linux expects to be given a name for the new interface, and a new interface will be allocated for it by the kernel module. If left blank, one will be generated (tun|tap)([0-9]+).

tap, err := tuntap.Tap("tap1") // created tap1 device if available
tun, err := tuntap.Tun("")     // created tun device at first available id (tun0)

Mac OS X

On startup, the Mac OS X TUN/TAP kernel extension will allocate multiple TUN/TAP devices, up to the maximum number of each. When creating a TUN/TAP device, Mac OS X expects to be given a path to an unused device. If left blank, this package will attempt to find the first unused one.

tap, err := tuntap.Tap("/dev/tap1") // open tap1 device if unused
tun, err := tuntap.Tun("")          // open first available tun device (tun0)

Additionally, unlike Linux, a TUN/TAP device is not "ready" on OS X until it has an address assigned to it. Any attempt to read from/write to the interface will fail with ErrBusy. It is safe to backoff and try again until a successful operation.

Examples

See the examples directory.