From 967d1a0f3d7aae4a0720895a2f6e35156b34214b Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Fri, 1 Mar 2019 00:05:57 +0100
Subject: [PATCH] tun: allow special methods in NativeTun

---
 tun/tun.go         |  2 +-
 tun/tun_darwin.go  | 24 ++++++++++++------------
 tun/tun_freebsd.go | 24 ++++++++++++------------
 tun/tun_linux.go   | 28 ++++++++++++++--------------
 tun/tun_openbsd.go | 24 ++++++++++++------------
 tun/tun_windows.go | 28 ++++++++++++++--------------
 6 files changed, 65 insertions(+), 65 deletions(-)

diff --git a/tun/tun.go b/tun/tun.go
index 3493b48..f38ee31 100644
--- a/tun/tun.go
+++ b/tun/tun.go
@@ -28,7 +28,7 @@ type TUNDevice interface {
 	Close() error                   // stops the device and closes the event channel
 }
 
-func (tun *nativeTun) operateOnFd(fn func(fd uintptr)) {
+func (tun *NativeTun) operateOnFd(fn func(fd uintptr)) {
 	sysconn, err := tun.tunFile.SyscallConn()
 	if err != nil {
 		tun.errors <- fmt.Errorf("unable to find sysconn for tunfile: %s", err.Error())
diff --git a/tun/tun_darwin.go b/tun/tun_darwin.go
index 8cb2981..600b156 100644
--- a/tun/tun_darwin.go
+++ b/tun/tun_darwin.go
@@ -31,7 +31,7 @@ type sockaddrCtl struct {
 	scReserved [5]uint32
 }
 
-type nativeTun struct {
+type NativeTun struct {
 	name        string
 	tunFile     *os.File
 	events      chan TUNEvent
@@ -41,7 +41,7 @@ type nativeTun struct {
 
 var sockaddrCtlSize uintptr = 32
 
-func (tun *nativeTun) routineRouteListener(tunIfindex int) {
+func (tun *NativeTun) routineRouteListener(tunIfindex int) {
 	var (
 		statusUp  bool
 		statusMTU int
@@ -160,7 +160,7 @@ func CreateTUN(name string, mtu int) (TUNDevice, error) {
 	if err == nil && name == "utun" {
 		fname := os.Getenv("WG_TUN_NAME_FILE")
 		if fname != "" {
-			ioutil.WriteFile(fname, []byte(tun.(*nativeTun).name+"\n"), 0400)
+			ioutil.WriteFile(fname, []byte(tun.(*NativeTun).name+"\n"), 0400)
 		}
 	}
 
@@ -168,7 +168,7 @@ func CreateTUN(name string, mtu int) (TUNDevice, error) {
 }
 
 func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
-	tun := &nativeTun{
+	tun := &NativeTun{
 		tunFile: file,
 		events:  make(chan TUNEvent, 10),
 		errors:  make(chan error, 1),
@@ -209,7 +209,7 @@ func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
 	return tun, nil
 }
 
-func (tun *nativeTun) Name() (string, error) {
+func (tun *NativeTun) Name() (string, error) {
 	var ifName struct {
 		name [16]byte
 	}
@@ -234,15 +234,15 @@ func (tun *nativeTun) Name() (string, error) {
 	return tun.name, nil
 }
 
-func (tun *nativeTun) File() *os.File {
+func (tun *NativeTun) File() *os.File {
 	return tun.tunFile
 }
 
-func (tun *nativeTun) Events() chan TUNEvent {
+func (tun *NativeTun) Events() chan TUNEvent {
 	return tun.events
 }
 
-func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Read(buff []byte, offset int) (int, error) {
 	select {
 	case err := <-tun.errors:
 		return 0, err
@@ -256,7 +256,7 @@ func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
 	}
 }
 
-func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Write(buff []byte, offset int) (int, error) {
 
 	// reserve space for header
 
@@ -279,7 +279,7 @@ func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
 	return tun.tunFile.Write(buff)
 }
 
-func (tun *nativeTun) Close() error {
+func (tun *NativeTun) Close() error {
 	var err2 error
 	err1 := tun.tunFile.Close()
 	if tun.routeSocket != -1 {
@@ -295,7 +295,7 @@ func (tun *nativeTun) Close() error {
 	return err2
 }
 
-func (tun *nativeTun) setMTU(n int) error {
+func (tun *NativeTun) setMTU(n int) error {
 
 	// open datagram socket
 
@@ -332,7 +332,7 @@ func (tun *nativeTun) setMTU(n int) error {
 	return nil
 }
 
-func (tun *nativeTun) MTU() (int, error) {
+func (tun *NativeTun) MTU() (int, error) {
 
 	// open datagram socket
 
diff --git a/tun/tun_freebsd.go b/tun/tun_freebsd.go
index 9e5c5ad..3a60725 100644
--- a/tun/tun_freebsd.go
+++ b/tun/tun_freebsd.go
@@ -48,7 +48,7 @@ type ifstat struct {
 	Ascii   [_IFSTATMAX]byte
 }
 
-type nativeTun struct {
+type NativeTun struct {
 	name        string
 	tunFile     *os.File
 	events      chan TUNEvent
@@ -56,7 +56,7 @@ type nativeTun struct {
 	routeSocket int
 }
 
-func (tun *nativeTun) routineRouteListener(tunIfindex int) {
+func (tun *NativeTun) routineRouteListener(tunIfindex int) {
 	var (
 		statusUp  bool
 		statusMTU int
@@ -240,7 +240,7 @@ func CreateTUN(name string, mtu int) (TUNDevice, error) {
 		return nil, err
 	}
 
-	tun := nativeTun{tunFile: tunFile}
+	tun := NativeTun{tunFile: tunFile}
 	var assignedName string
 	tun.operateOnFd(func(fd uintptr) {
 		assignedName, err = tunName(fd)
@@ -307,7 +307,7 @@ func CreateTUN(name string, mtu int) (TUNDevice, error) {
 
 func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
 
-	tun := &nativeTun{
+	tun := &NativeTun{
 		tunFile: file,
 		events:  make(chan TUNEvent, 10),
 		errors:  make(chan error, 1),
@@ -348,7 +348,7 @@ func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
 	return tun, nil
 }
 
-func (tun *nativeTun) Name() (string, error) {
+func (tun *NativeTun) Name() (string, error) {
 	var name string
 	var err error
 	tun.operateOnFd(func(fd uintptr) {
@@ -361,15 +361,15 @@ func (tun *nativeTun) Name() (string, error) {
 	return name, nil
 }
 
-func (tun *nativeTun) File() *os.File {
+func (tun *NativeTun) File() *os.File {
 	return tun.tunFile
 }
 
-func (tun *nativeTun) Events() chan TUNEvent {
+func (tun *NativeTun) Events() chan TUNEvent {
 	return tun.events
 }
 
-func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Read(buff []byte, offset int) (int, error) {
 	select {
 	case err := <-tun.errors:
 		return 0, err
@@ -383,7 +383,7 @@ func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
 	}
 }
 
-func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Write(buff []byte, offset int) (int, error) {
 
 	// reserve space for header
 
@@ -406,7 +406,7 @@ func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
 	return tun.tunFile.Write(buff)
 }
 
-func (tun *nativeTun) Close() error {
+func (tun *NativeTun) Close() error {
 	var err3 error
 	err1 := tun.tunFile.Close()
 	err2 := tunDestroy(tun.name)
@@ -426,7 +426,7 @@ func (tun *nativeTun) Close() error {
 	return err3
 }
 
-func (tun *nativeTun) setMTU(n int) error {
+func (tun *NativeTun) setMTU(n int) error {
 	// open datagram socket
 
 	var fd int
@@ -463,7 +463,7 @@ func (tun *nativeTun) setMTU(n int) error {
 	return nil
 }
 
-func (tun *nativeTun) MTU() (int, error) {
+func (tun *NativeTun) MTU() (int, error) {
 	// open datagram socket
 
 	fd, err := unix.Socket(
diff --git a/tun/tun_linux.go b/tun/tun_linux.go
index 17075d9..f808079 100644
--- a/tun/tun_linux.go
+++ b/tun/tun_linux.go
@@ -28,7 +28,7 @@ const (
 	ifReqSize       = unix.IFNAMSIZ + 64
 )
 
-type nativeTun struct {
+type NativeTun struct {
 	tunFile                 *os.File
 	fd                      uintptr
 	fdCancel                *rwcancel.RWCancel
@@ -43,11 +43,11 @@ type nativeTun struct {
 	statusListenersShutdown chan struct{}
 }
 
-func (tun *nativeTun) File() *os.File {
+func (tun *NativeTun) File() *os.File {
 	return tun.tunFile
 }
 
-func (tun *nativeTun) routineHackListener() {
+func (tun *NativeTun) routineHackListener() {
 	defer tun.hackListenerClosed.Unlock()
 	/* This is needed for the detection to work across network namespaces
 	 * If you are reading this and know a better method, please get in touch.
@@ -87,7 +87,7 @@ func createNetlinkSocket() (int, error) {
 	return sock, nil
 }
 
-func (tun *nativeTun) routineNetlinkListener() {
+func (tun *NativeTun) routineNetlinkListener() {
 	defer func() {
 		unix.Close(tun.netlinkSock)
 		tun.hackListenerClosed.Lock()
@@ -157,7 +157,7 @@ func (tun *nativeTun) routineNetlinkListener() {
 	}
 }
 
-func (tun *nativeTun) isUp() (bool, error) {
+func (tun *NativeTun) isUp() (bool, error) {
 	inter, err := net.InterfaceByName(tun.name)
 	return inter.Flags&net.FlagUp != 0, err
 }
@@ -190,7 +190,7 @@ func getIFIndex(name string) (int32, error) {
 	return *(*int32)(unsafe.Pointer(&ifr[unix.IFNAMSIZ])), nil
 }
 
-func (tun *nativeTun) setMTU(n int) error {
+func (tun *NativeTun) setMTU(n int) error {
 	// open datagram socket
 	fd, err := unix.Socket(
 		unix.AF_INET,
@@ -223,7 +223,7 @@ func (tun *nativeTun) setMTU(n int) error {
 	return nil
 }
 
-func (tun *nativeTun) MTU() (int, error) {
+func (tun *NativeTun) MTU() (int, error) {
 	// open datagram socket
 	fd, err := unix.Socket(
 		unix.AF_INET,
@@ -254,7 +254,7 @@ func (tun *nativeTun) MTU() (int, error) {
 	return int(*(*int32)(unsafe.Pointer(&ifr[unix.IFNAMSIZ]))), nil
 }
 
-func (tun *nativeTun) Name() (string, error) {
+func (tun *NativeTun) Name() (string, error) {
 	var ifr [ifReqSize]byte
 	_, _, errno := unix.Syscall(
 		unix.SYS_IOCTL,
@@ -274,7 +274,7 @@ func (tun *nativeTun) Name() (string, error) {
 	return tun.name, nil
 }
 
-func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Write(buff []byte, offset int) (int, error) {
 
 	if tun.nopi {
 		buff = buff[offset:]
@@ -302,7 +302,7 @@ func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
 	return tun.tunFile.Write(buff)
 }
 
-func (tun *nativeTun) doRead(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) doRead(buff []byte, offset int) (int, error) {
 	select {
 	case err := <-tun.errors:
 		return 0, err
@@ -320,7 +320,7 @@ func (tun *nativeTun) doRead(buff []byte, offset int) (int, error) {
 	}
 }
 
-func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Read(buff []byte, offset int) (int, error) {
 	for {
 		n, err := tun.doRead(buff, offset)
 		if err == nil || !rwcancel.RetryAfterError(err) {
@@ -332,11 +332,11 @@ func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
 	}
 }
 
-func (tun *nativeTun) Events() chan TUNEvent {
+func (tun *NativeTun) Events() chan TUNEvent {
 	return tun.events
 }
 
-func (tun *nativeTun) Close() error {
+func (tun *NativeTun) Close() error {
 	var err1 error
 	if tun.statusListenersShutdown != nil {
 		close(tun.statusListenersShutdown)
@@ -394,7 +394,7 @@ func CreateTUN(name string, mtu int) (TUNDevice, error) {
 }
 
 func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
-	tun := &nativeTun{
+	tun := &NativeTun{
 		tunFile:                 file,
 		fd:                      file.Fd(),
 		events:                  make(chan TUNEvent, 5),
diff --git a/tun/tun_openbsd.go b/tun/tun_openbsd.go
index 4e740c5..57edcb4 100644
--- a/tun/tun_openbsd.go
+++ b/tun/tun_openbsd.go
@@ -25,7 +25,7 @@ type ifreq_mtu struct {
 
 const _TUNSIFMODE = 0x8004745d
 
-type nativeTun struct {
+type NativeTun struct {
 	name        string
 	tunFile     *os.File
 	events      chan TUNEvent
@@ -33,7 +33,7 @@ type nativeTun struct {
 	routeSocket int
 }
 
-func (tun *nativeTun) routineRouteListener(tunIfindex int) {
+func (tun *NativeTun) routineRouteListener(tunIfindex int) {
 	var (
 		statusUp  bool
 		statusMTU int
@@ -131,7 +131,7 @@ func CreateTUN(name string, mtu int) (TUNDevice, error) {
 	if err == nil && name == "tun" {
 		fname := os.Getenv("WG_TUN_NAME_FILE")
 		if fname != "" {
-			ioutil.WriteFile(fname, []byte(tun.(*nativeTun).name+"\n"), 0400)
+			ioutil.WriteFile(fname, []byte(tun.(*NativeTun).name+"\n"), 0400)
 		}
 	}
 
@@ -140,7 +140,7 @@ func CreateTUN(name string, mtu int) (TUNDevice, error) {
 
 func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
 
-	tun := &nativeTun{
+	tun := &NativeTun{
 		tunFile: file,
 		events:  make(chan TUNEvent, 10),
 		errors:  make(chan error, 1),
@@ -181,7 +181,7 @@ func CreateTUNFromFile(file *os.File, mtu int) (TUNDevice, error) {
 	return tun, nil
 }
 
-func (tun *nativeTun) Name() (string, error) {
+func (tun *NativeTun) Name() (string, error) {
 	gostat, err := tun.tunFile.Stat()
 	if err != nil {
 		tun.name = ""
@@ -192,15 +192,15 @@ func (tun *nativeTun) Name() (string, error) {
 	return tun.name, nil
 }
 
-func (tun *nativeTun) File() *os.File {
+func (tun *NativeTun) File() *os.File {
 	return tun.tunFile
 }
 
-func (tun *nativeTun) Events() chan TUNEvent {
+func (tun *NativeTun) Events() chan TUNEvent {
 	return tun.events
 }
 
-func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Read(buff []byte, offset int) (int, error) {
 	select {
 	case err := <-tun.errors:
 		return 0, err
@@ -214,7 +214,7 @@ func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
 	}
 }
 
-func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Write(buff []byte, offset int) (int, error) {
 
 	// reserve space for header
 
@@ -237,7 +237,7 @@ func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
 	return tun.tunFile.Write(buff)
 }
 
-func (tun *nativeTun) Close() error {
+func (tun *NativeTun) Close() error {
 	var err2 error
 	err1 := tun.tunFile.Close()
 	if tun.routeSocket != -1 {
@@ -253,7 +253,7 @@ func (tun *nativeTun) Close() error {
 	return err2
 }
 
-func (tun *nativeTun) setMTU(n int) error {
+func (tun *NativeTun) setMTU(n int) error {
 	// open datagram socket
 
 	var fd int
@@ -290,7 +290,7 @@ func (tun *nativeTun) setMTU(n int) error {
 	return nil
 }
 
-func (tun *nativeTun) MTU() (int, error) {
+func (tun *NativeTun) MTU() (int, error) {
 	// open datagram socket
 
 	fd, err := unix.Socket(
diff --git a/tun/tun_windows.go b/tun/tun_windows.go
index e9bf0b7..ed6d7d2 100644
--- a/tun/tun_windows.go
+++ b/tun/tun_windows.go
@@ -34,7 +34,7 @@ type exchgBufWrite struct {
 	packetNum uint32
 }
 
-type nativeTun struct {
+type NativeTun struct {
 	wt           *wintun.Wintun
 	tunName      string
 	signalName   *uint16
@@ -88,7 +88,7 @@ func CreateTUN(ifname string) (TUNDevice, error) {
 	}
 
 	// Create instance.
-	tun := &nativeTun{
+	tun := &NativeTun{
 		wt:         wt,
 		tunName:    wt.DataFileName(),
 		signalName: signalNameUTF16,
@@ -108,7 +108,7 @@ func CreateTUN(ifname string) (TUNDevice, error) {
 	return tun, nil
 }
 
-func (tun *nativeTun) openTUN() error {
+func (tun *NativeTun) openTUN() error {
 	for {
 		// Open interface data pipe.
 		// Data pipe must be opened first, as the interface data available event is created when somebody actually connects to the data pipe.
@@ -140,7 +140,7 @@ func (tun *nativeTun) openTUN() error {
 	}
 }
 
-func (tun *nativeTun) closeTUN() (err error) {
+func (tun *NativeTun) closeTUN() (err error) {
 	tun.tunLock.Lock()
 	defer tun.tunLock.Unlock()
 
@@ -167,7 +167,7 @@ func (tun *nativeTun) closeTUN() (err error) {
 	return
 }
 
-func (tun *nativeTun) getTUN() (*os.File, windows.Handle, error) {
+func (tun *NativeTun) getTUN() (*os.File, windows.Handle, error) {
 	tun.tunLock.Lock()
 	defer tun.tunLock.Unlock()
 
@@ -182,19 +182,19 @@ func (tun *nativeTun) getTUN() (*os.File, windows.Handle, error) {
 	return tun.tunFile, tun.tunDataAvail, nil
 }
 
-func (tun *nativeTun) Name() (string, error) {
+func (tun *NativeTun) Name() (string, error) {
 	return tun.wt.GetInterfaceName()
 }
 
-func (tun *nativeTun) File() *os.File {
+func (tun *NativeTun) File() *os.File {
 	return nil
 }
 
-func (tun *nativeTun) Events() chan TUNEvent {
+func (tun *NativeTun) Events() chan TUNEvent {
 	return tun.events
 }
 
-func (tun *nativeTun) Close() error {
+func (tun *NativeTun) Close() error {
 	windows.SetEvent(tun.userClose)
 	err := windows.CloseHandle(tun.userClose)
 
@@ -215,11 +215,11 @@ func (tun *nativeTun) Close() error {
 	return err
 }
 
-func (tun *nativeTun) MTU() (int, error) {
+func (tun *NativeTun) MTU() (int, error) {
 	return 1500, nil
 }
 
-func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Read(buff []byte, offset int) (int, error) {
 	select {
 	case err := <-tun.errors:
 		return 0, err
@@ -292,7 +292,7 @@ func (tun *nativeTun) Read(buff []byte, offset int) (int, error) {
 
 // Note: flush() and putTunPacket() assume the caller comes only from a single thread; there's no locking.
 
-func (tun *nativeTun) flush() error {
+func (tun *NativeTun) flush() error {
 	// Get TUN data pipe.
 	file, _, err := tun.getTUN()
 	if err != nil {
@@ -312,7 +312,7 @@ func (tun *nativeTun) flush() error {
 	return nil
 }
 
-func (tun *nativeTun) putTunPacket(buff []byte) error {
+func (tun *NativeTun) putTunPacket(buff []byte) error {
 	size := uint32(len(buff))
 	if size == 0 {
 		return errors.New("Empty packet")
@@ -341,7 +341,7 @@ func (tun *nativeTun) putTunPacket(buff []byte) error {
 	return nil
 }
 
-func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
+func (tun *NativeTun) Write(buff []byte, offset int) (int, error) {
 	err := tun.putTunPacket(buff[offset:])
 	if err != nil {
 		return 0, err