From 676bb9143461ae25304c414fb19595fef9c310db Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Thu, 19 Apr 2018 15:54:33 +0200
Subject: [PATCH] We can determine the interface name ourselves

---
 main.go      |  2 +-
 tun_linux.go | 10 +++++++---
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/main.go b/main.go
index b12bb09..7742eef 100644
--- a/main.go
+++ b/main.go
@@ -90,7 +90,7 @@ func main() {
 		}
 
 		file := os.NewFile(uintptr(fd), "")
-		return CreateTUNFromFile(interfaceName, file)
+		return CreateTUNFromFile(file)
 	}()
 
 	if err != nil {
diff --git a/tun_linux.go b/tun_linux.go
index 06b5af4..ac9824f 100644
--- a/tun_linux.go
+++ b/tun_linux.go
@@ -308,18 +308,22 @@ func (tun *NativeTun) Close() error {
 	return tun.fd.Close()
 }
 
-func CreateTUNFromFile(name string, fd *os.File) (TUNDevice, error) {
+func CreateTUNFromFile(fd *os.File) (TUNDevice, error) {
 	device := &NativeTun{
 		fd:     fd,
-		name:   name,
 		events: make(chan TUNEvent, 5),
 		errors: make(chan error, 5),
 		nopi:   false,
 	}
+	var err error
+
+	_, err = device.Name()
+	if err != nil {
+		return nil, err
+	}
 
 	// start event listener
 
-	var err error
 	device.index, err = getIFIndex(device.name)
 	if err != nil {
 		return nil, err