wintun: Introduce new package for obscuring Windows bits

12 files changed, 527 insertions, 487 deletions

diff --git a/setupapi/setupapi.go b/setupapi/setupapi.go
deleted file mode 100644
index 69703b3..0000000
--- a/setupapi/setupapi.go
+++ /dev/null
@@ -1,6 +0,0 @@
-/* SPDX-License-Identifier: MIT
- *
- * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
- */
-
-package setupapi
diff --git a/tun/tun_windows.go b/tun/tun_windows.go
index d7cd762..6449974 100644
--- a/tun/tun_windows.go
+++ b/tun/tun_windows.go
@@ -5,20 +5,14 @@
 
 package tun
 
-//go:generate go run $GOROOT/src/syscall/mksyscall_windows.go -output ztun_windows.go tun_windows.go
-
 import (
 	"errors"
 	"fmt"
 	"os"
-	"strings"
-	"syscall"
-	"time"
 	"unsafe"
 
-	"git.zx2c4.com/wireguard-go/setupapi"
+	"git.zx2c4.com/wireguard-go/tun/wintun"
 	"golang.org/x/sys/windows"
-	"golang.org/x/sys/windows/registry"
 )
 
 const (
@@ -34,10 +28,6 @@ const (
 	TUN_SIGNAL_MAX = 2
 )
 
-var deviceClassNetGUID = windows.GUID{0x4d36e972, 0xe325, 0x11ce, [8]byte{0xbf, 0xc1, 0x08, 0x00, 0x2b, 0xe1, 0x03, 0x18}}
-
-const TUN_HWID = "Wintun"
-
 type tunPacket struct {
 	size uint32
 	data [TUN_MAX_PACKET_SIZE]byte
@@ -50,7 +40,7 @@ type tunRWQueue struct {
 }
 
 type nativeTun struct {
-	ifid         *windows.GUID
+	wt           *wintun.Wintun
 	tunName      string
 	signalName   *uint16
 	tunFile      *os.File
@@ -64,30 +54,28 @@ type nativeTun struct {
 
 func CreateTUN(ifname string) (TUNDevice, error) {
 	// Does an interface with this name already exist?
-	ifid, err := getInterface(ifname, 0)
-	if ifid == nil || err != nil {
+	wt, err := wintun.GetInterface(ifname, 0)
+	if wt == nil || err != nil {
 		// Interface does not exist or an error occured. Create one.
-		ifid, _, err = createInterface("WireGuard Tunnel Adapter", 0)
+		wt, _, err = wintun.CreateInterface("WireGuard Tunnel Adapter", 0)
 		if err != nil {
 			return nil, err
 		}
 
 		// Set interface name. (Ignore errors.)
-		setInterfaceName(ifid, ifname)
+		wt.SetInterfaceName(ifname)
 	}
 
-	ifidStr := guidToString(ifid)
-
-	signalNameUTF16, err := windows.UTF16PtrFromString(fmt.Sprintf("Global\\WINTUN_EVENT_%s", ifidStr))
+	signalNameUTF16, err := windows.UTF16PtrFromString(wt.SignalEventName())
 	if err != nil {
-		deleteInterface(ifid, 0)
+		wt.DeleteInterface(0)
 		return nil, err
 	}
 
 	// Create instance.
 	tun := &nativeTun{
-		ifid:       ifid,
-		tunName:    fmt.Sprintf("\\\\.\\Global\\WINTUN_DEVICE_%s", ifidStr),
+		wt:         wt,
+		tunName:    wt.DataFileName(),
 		signalName: signalNameUTF16,
 		events:     make(chan TUNEvent, 10),
 		errors:     make(chan error, 1),
@@ -96,7 +84,7 @@ func CreateTUN(ifname string) (TUNDevice, error) {
 	// Create close event.
 	tun.signals[TUN_SIGNAL_CLOSE], err = windows.CreateEvent(nil, 1 /*TRUE*/, 0 /*FALSE*/, nil)
 	if err != nil {
-		deleteInterface(ifid, 0)
+		wt.DeleteInterface(0)
 		return nil, err
 	}
 
@@ -160,7 +148,7 @@ func (tun *nativeTun) closeTUN() (err error) {
 }
 
 func (tun *nativeTun) Name() (string, error) {
-	return getInterfaceName(tun.ifid)
+	return tun.wt.GetInterfaceName()
 }
 
 func (tun *nativeTun) File() *os.File {
@@ -184,7 +172,7 @@ func (tun *nativeTun) Close() error {
 		close(tun.events)
 	}
 
-	_, _, e = deleteInterface(tun.ifid, 0)
+	_, _, e = tun.wt.DeleteInterface(0)
 	if err == nil {
 		err = e
 	}
@@ -317,458 +305,3 @@ func (tun *nativeTun) Write(buff []byte, offset int) (int, error) {
 	// Flush write buffer.
 	return len(buff) - offset, tun.flush()
 }
-
-//
-// getInterface finds interface ID by name.
-//
-// hwndParent is a handle to the top-level window to use for any user
-// interface that is related to non-device-specific actions (such as a select-
-// device dialog box that uses the global class driver list). This handle is
-// optional and can be 0. If a specific top-level window is not required, set
-// hwndParent to 0.
-//
-// Function returns interface ID when the interface was found, or nil
-// otherwise.
-//
-func getInterface(ifname string, hwndParent uintptr) (*windows.GUID, error) {
-	// Create a list of network devices.
-	devInfoList, err := setupapi.SetupDiGetClassDevsEx(&deviceClassNetGUID, "", hwndParent, setupapi.DIGCF_PRESENT, setupapi.DevInfo(0), "")
-	if err != nil {
-		return nil, err
-	}
-	defer devInfoList.Close()
-
-	// Retrieve information associated with a device information set.
-	// TODO: Is this really necessary?
-	_, err = devInfoList.GetDeviceInfoListDetail()
-	if err != nil {
-		return nil, err
-	}
-
-	// TODO: If we're certain we want case-insensitive name comparison, please document the rationale.
-	ifname = strings.ToLower(ifname)
-
-	// Iterate.
-	for index := 0; ; index++ {
-		// Get the device from the list.
-		deviceData, err := devInfoList.EnumDeviceInfo(index)
-		if err != nil {
-			if errWin, ok := err.(syscall.Errno); ok && errWin == 259 /*ERROR_NO_MORE_ITEMS*/ {
-				break
-			}
-			// Something is wrong with this device. Skip it.
-			continue
-		}
-
-		// Get interface ID.
-		ifid, err := getInterfaceId(devInfoList, deviceData, 1)
-		if err != nil {
-			// Something is wrong with this device. Skip it.
-			continue
-		}
-
-		// Get interface name.
-		ifname2, err := getInterfaceName(ifid)
-		if err != nil {
-			// Something is wrong with this device. Skip it.
-			continue
-		}
-
-		if ifname == strings.ToLower(ifname2) {
-			// Interface name found.
-			return ifid, nil
-		}
-	}
-
-	return nil, nil
-}
-
-//
-// createInterface creates a TUN interface.
-//
-// description is a string that supplies the text description of the device.
-// Description is optional and can be "".
-//
-// hwndParent is a handle to the top-level window to use for any user
-// interface that is related to non-device-specific actions (such as a select-
-// device dialog box that uses the global class driver list). This handle is
-// optional and can be 0. If a specific top-level window is not required, set
-// hwndParent to 0.
-//
-// Function returns the network interface ID and a flag if reboot is required.
-//
-func createInterface(description string, hwndParent uintptr) (*windows.GUID, bool, error) {
-	// Create an empty device info set for network adapter device class.
-	devInfoList, err := setupapi.SetupDiCreateDeviceInfoListEx(&deviceClassNetGUID, hwndParent, "")
-	if err != nil {
-		return nil, false, err
-	}
-
-	// Get the device class name from GUID.
-	className, err := setupapi.SetupDiClassNameFromGuidEx(&deviceClassNetGUID, "")
-	if err != nil {
-		return nil, false, err
-	}
-
-	// Create a new device info element and add it to the device info set.
-	deviceData, err := devInfoList.CreateDeviceInfo(className, &deviceClassNetGUID, description, hwndParent, setupapi.DICD_GENERATE_ID)
-	if err != nil {
-		return nil, false, err
-	}
-
-	// Set a device information element as the selected member of a device information set.
-	err = devInfoList.SetSelectedDevice(deviceData)
-	if err != nil {
-		return nil, false, err
-	}
-
-	// Set Plug&Play device hardware ID property.
-	hwid, err := syscall.UTF16FromString(TUN_HWID)
-	if err != nil {
-		return nil, false, err
-	}
-	err = devInfoList.SetDeviceRegistryProperty(deviceData, setupapi.SPDRP_HARDWAREID, setupapi.UTF16ToBuf(append(hwid, 0)))
-	if err != nil {
-		return nil, false, err
-	}
-
-	// Search for the driver.
-	const driverType = setupapi.SPDIT_CLASSDRIVER
-	err = devInfoList.BuildDriverInfoList(deviceData, driverType)
-	if err != nil {
-		return nil, false, err
-	}
-	defer devInfoList.DestroyDriverInfoList(deviceData, driverType)
-
-	driverDate := windows.Filetime{}
-	driverVersion := uint64(0)
-	for index := 0; ; index++ {
-		// Get a driver from the list.
-		driverData, err := devInfoList.EnumDriverInfo(deviceData, driverType, index)
-		if err != nil {
-			if errWin, ok := err.(syscall.Errno); ok && errWin == 259 /*ERROR_NO_MORE_ITEMS*/ {
-				break
-			}
-			// Something is wrong with this driver. Skip it.
-			continue
-		}
-
-		// Check the driver version first, since the check is trivial and will save us iterating over hardware IDs for any driver versioned prior our best match.
-		if driverData.IsNewer(driverDate, driverVersion) {
-			// Get driver info details.
-			driverDetailData, err := devInfoList.GetDriverInfoDetail(deviceData, driverData)
-			if err != nil {
-				// Something is wrong with this driver. Skip it.
-				continue
-			}
-
-			if driverDetailData.IsCompatible(TUN_HWID) {
-				// Matching hardware ID found. Select the driver.
-				err := devInfoList.SetSelectedDriver(deviceData, driverData)
-				if err != nil {
-					// Something is wrong with this driver. Skip it.
-					continue
-				}
-
-				driverDate = driverData.DriverDate
-				driverVersion = driverData.DriverVersion
-			}
-		}
-	}
-
-	if driverVersion == 0 {
-		return nil, false, fmt.Errorf("No driver for device \"%v\" installed", TUN_HWID)
-	}
-
-	// Call appropriate class installer.
-	err = devInfoList.CallClassInstaller(setupapi.DIF_REGISTERDEVICE, deviceData)
-	if err != nil {
-		return nil, false, err
-	}
-
-	// Register device co-installers if any.
-	devInfoList.CallClassInstaller(setupapi.DIF_REGISTER_COINSTALLERS, deviceData)
-
-	// Install interfaces if any.
-	devInfoList.CallClassInstaller(setupapi.DIF_INSTALLINTERFACES, deviceData)
-
-	var ifid *windows.GUID
-	var rebootRequired bool
-
-	// Install the device.
-	err = devInfoList.CallClassInstaller(setupapi.DIF_INSTALLDEVICE, deviceData)
-	if err == nil {
-		// Check if a system reboot is required. (Ignore errors)
-		if ret, _ := checkReboot(devInfoList, deviceData); ret {
-			rebootRequired = true
-		}
-
-		// Get network interface ID from registry. Retry for max 30sec.
-		ifid, err = getInterfaceId(devInfoList, deviceData, 30)
-	}
-
-	if err == nil {
-		return ifid, rebootRequired, nil
-	}
-
-	// The interface failed to install, or the interface ID was unobtainable. Clean-up.
-	removeDeviceParams := setupapi.SP_REMOVEDEVICE_PARAMS{
-		ClassInstallHeader: setupapi.SP_CLASSINSTALL_HEADER{
-			InstallFunction: setupapi.DIF_REMOVE,
-		},
-		Scope: setupapi.DI_REMOVEDEVICE_GLOBAL,
-	}
-	removeDeviceParams.ClassInstallHeader.Size = uint32(unsafe.Sizeof(removeDeviceParams.ClassInstallHeader))
-
-	// Set class installer parameters for DIF_REMOVE.
-	if devInfoList.SetClassInstallParams(deviceData, &removeDeviceParams.ClassInstallHeader, uint32(unsafe.Sizeof(removeDeviceParams))) == nil {
-		// Call appropriate class installer.
-		if devInfoList.CallClassInstaller(setupapi.DIF_REMOVE, deviceData) == nil {
-			// Check if a system reboot is required. (Ignore errors)
-			if ret, _ := checkReboot(devInfoList, deviceData); ret {
-				rebootRequired = true
-			}
-		}
-	}
-
-	return nil, false, err
-}
-
-//
-// deleteInterface deletes a TUN interface.
-//
-// hwndParent is a handle to the top-level window to use for any user
-// interface that is related to non-device-specific actions (such as a select-
-// device dialog box that uses the global class driver list). This handle is
-// optional and can be 0. If a specific top-level window is not required, set
-// hwndParent to 0.
-//
-// Function returns true if the interface was found and deleted and a flag if
-// reboot is required.
-//
-func deleteInterface(ifid *windows.GUID, hwndParent uintptr) (bool, bool, error) {
-	// Create a list of network devices.
-	devInfoList, err := setupapi.SetupDiGetClassDevsEx(&deviceClassNetGUID, "", hwndParent, setupapi.DIGCF_PRESENT, setupapi.DevInfo(0), "")
-	if err != nil {
-		return false, false, err
-	}
-	defer devInfoList.Close()
-
-	// Retrieve information associated with a device information set.
-	// TODO: Is this really necessary?
-	_, err = devInfoList.GetDeviceInfoListDetail()
-	if err != nil {
-		return false, false, err
-	}
-
-	// Iterate.
-	for index := 0; ; index++ {
-		// Get the device from the list.
-		deviceData, err := devInfoList.EnumDeviceInfo(index)
-		if err != nil {
-			if errWin, ok := err.(syscall.Errno); ok && errWin == 259 /*ERROR_NO_MORE_ITEMS*/ {
-				break
-			}
-			// Something is wrong with this device. Skip it.
-			continue
-		}
-
-		// Get interface ID.
-		ifid2, err := getInterfaceId(devInfoList, deviceData, 1)
-		if err != nil {
-			// Something is wrong with this device. Skip it.
-			continue
-		}
-
-		if ifid == ifid2 {
-			// Remove the device.
-			removeDeviceParams := setupapi.SP_REMOVEDEVICE_PARAMS{
-				ClassInstallHeader: setupapi.SP_CLASSINSTALL_HEADER{
-					InstallFunction: setupapi.DIF_REMOVE,
-				},
-				Scope: setupapi.DI_REMOVEDEVICE_GLOBAL,
-			}
-			removeDeviceParams.ClassInstallHeader.Size = uint32(unsafe.Sizeof(removeDeviceParams.ClassInstallHeader))
-
-			// Set class installer parameters for DIF_REMOVE.
-			err = devInfoList.SetClassInstallParams(deviceData, &removeDeviceParams.ClassInstallHeader, uint32(unsafe.Sizeof(removeDeviceParams)))
-			if err != nil {
-				return false, false, err
-			}
-
-			// Call appropriate class installer.
-			err = devInfoList.CallClassInstaller(setupapi.DIF_REMOVE, deviceData)
-			if err != nil {
-				return false, false, err
-			}
-
-			// Check if a system reboot is required. (Ignore errors)
-			if ret, _ := checkReboot(devInfoList, deviceData); ret {
-				return true, true, nil
-			}
-
-			return true, false, nil
-		}
-	}
-
-	return false, false, nil
-}
-
-///
-/// checkReboot checks device install parameters if a system reboot is required.
-///
-func checkReboot(deviceInfoSet setupapi.DevInfo, deviceInfoData *setupapi.SP_DEVINFO_DATA) (bool, error) {
-	devInstallParams, err := deviceInfoSet.GetDeviceInstallParams(deviceInfoData)
-	if err != nil {
-		return false, err
-	}
-
-	if (devInstallParams.Flags & (setupapi.DI_NEEDREBOOT | setupapi.DI_NEEDRESTART)) != 0 {
-		return true, nil
-	}
-
-	return false, nil
-}
-
-// getInterfaceId returns network interface ID.
-//
-// After the device is created, it might take some time before the registry
-// key is populated. numAttempts parameter specifies the number of attempts
-// to read NetCfgInstanceId value from registry. A 1sec sleep is inserted
-// between retry attempts.
-//
-// Function returns the network interface ID.
-//
-func getInterfaceId(deviceInfoSet setupapi.DevInfo, deviceInfoData *setupapi.SP_DEVINFO_DATA, numAttempts int) (*windows.GUID, error) {
-	if numAttempts < 1 {
-		return nil, fmt.Errorf("Invalid numAttempts (expected: >=1, provided: %v)", numAttempts)
-	}
-
-	// Open HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\<class>\<id> registry key.
-	key, err := deviceInfoSet.OpenDevRegKey(deviceInfoData, setupapi.DICS_FLAG_GLOBAL, 0, setupapi.DIREG_DRV, registry.READ)
-	if err != nil {
-		return nil, errors.New("Device-specific registry key open failed: " + err.Error())
-	}
-	defer key.Close()
-
-	for {
-		// Query the NetCfgInstanceId value. Using get_reg_string() right on might clutter the output with error messages while the registry is still being populated.
-		_, _, err = key.GetValue("NetCfgInstanceId", nil)
-		if err != nil {
-			if errWin, ok := err.(syscall.Errno); ok && errWin == windows.ERROR_FILE_NOT_FOUND {
-				numAttempts--
-				if numAttempts > 0 {
-					// Wait and retry.
-					// TODO: Wait for a cancellable event instead.
-					time.Sleep(1000 * time.Millisecond)
-					continue
-				}
-			}
-
-			return nil, errors.New("RegQueryValueEx(\"NetCfgInstanceId\") failed: " + err.Error())
-		}
-
-		// Read the NetCfgInstanceId value now.
-		value, err := getRegStringValue(key, "NetCfgInstanceId")
-		if err != nil {
-			return nil, errors.New("RegQueryStringValue(\"NetCfgInstanceId\") failed: " + err.Error())
-		}
-
-		// Convert to windows.GUID.
-		ifid, err := stringToGUID(value)
-		if err != nil {
-			return nil, fmt.Errorf("NetCfgInstanceId registry value is not a GUID (expected: \"{...}\", provided: \"%v\")", value)
-		}
-
-		return ifid, err
-	}
-}
-
-//
-// getInterfaceName returns network interface name.
-//
-func getInterfaceName(ifid *windows.GUID) (string, error) {
-	// Open network interface registry key.
-	key, err := registry.OpenKey(registry.LOCAL_MACHINE, fmt.Sprintf("SYSTEM\\CurrentControlSet\\Control\\Network\\%v\\%v\\Connection", guidToString(&deviceClassNetGUID), guidToString(ifid)), registry.QUERY_VALUE)
-	if err != nil {
-		return "", errors.New("Network-specific registry key open failed: " + err.Error())
-	}
-	defer key.Close()
-
-	// Get the interface name.
-	return getRegStringValue(key, "Name")
-}
-
-//
-// setInterfaceName sets network interface name.
-//
-func setInterfaceName(ifid *windows.GUID, ifname string) error {
-	// Open network interface registry key.
-	key, err := registry.OpenKey(registry.LOCAL_MACHINE, fmt.Sprintf("SYSTEM\\CurrentControlSet\\Control\\Network\\%v\\%v\\Connection", guidToString(&deviceClassNetGUID), guidToString(ifid)), registry.SET_VALUE)
-	if err != nil {
-		return errors.New("Network-specific registry key open failed: " + err.Error())
-	}
-	defer key.Close()
-
-	// Set the interface name.
-	return key.SetStringValue("Name", ifname)
-}
-
-//sys	clsidFromString(lpsz *uint16, pclsid *windows.GUID) (hr int32) = ole32.CLSIDFromString
-
-//
-// stringToGUID parses "{XXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}" string to GUID.
-//
-func stringToGUID(str string) (*windows.GUID, error) {
-	strUTF16, err := syscall.UTF16PtrFromString(str)
-	if err != nil {
-		return nil, err
-	}
-
-	guid := &windows.GUID{}
-
-	hr := clsidFromString(strUTF16, guid)
-	if hr < 0 {
-		return nil, syscall.Errno(hr)
-	}
-
-	return guid, nil
-}
-
-//
-// guidToString function converts GUID to string
-// "{XXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}".
-//
-// The resulting string is uppercase.
-//
-func guidToString(guid *windows.GUID) string {
-	return fmt.Sprintf("{%06X-%04X-%04X-%04X-%012X}", guid.Data1, guid.Data2, guid.Data3, guid.Data4[:2], guid.Data4[2:])
-}
-
-//
-// getRegStringValue function reads a string value from registry.
-//
-// If the value type is REG_EXPAND_SZ the environment variables are expanded.
-// Should expanding fail, original string value and nil error are returned.
-//
-func getRegStringValue(key registry.Key, name string) (string, error) {
-	// Read string value.
-	value, valueType, err := key.GetStringValue(name)
-	if err != nil {
-		return "", err
-	}
-
-	if valueType != registry.EXPAND_SZ {
-		// Value does not require expansion.
-		return value, nil
-	}
-
-	valueExp, err := registry.ExpandString(value)
-	if err != nil {
-		// Expanding failed: return original sting value.
-		return value, nil
-	}
-
-	// Return expanded value.
-	return valueExp, nil
-}
diff --git a/tun/wintun/guid/guid_windows.go b/tun/wintun/guid/guid_windows.go
new file mode 100644
index 0000000..0078d2c
--- /dev/null
+++ b/tun/wintun/guid/guid_windows.go
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
+ */
+
+package guid
+
+import (
+	"fmt"
+	"syscall"
+
+	"golang.org/x/sys/windows"
+)
+
+//sys	clsidFromString(lpsz *uint16, pclsid *windows.GUID) (hr int32) = ole32.CLSIDFromString
+
+//
+// FromString parses "{XXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}" string to GUID.
+//
+func FromString(str string) (*windows.GUID, error) {
+	strUTF16, err := syscall.UTF16PtrFromString(str)
+	if err != nil {
+		return nil, err
+	}
+
+	guid := &windows.GUID{}
+
+	hr := clsidFromString(strUTF16, guid)
+	if hr < 0 {
+		return nil, syscall.Errno(hr)
+	}
+
+	return guid, nil
+}
+
+//
+// ToString function converts GUID to string
+// "{XXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}".
+//
+// The resulting string is uppercase.
+//
+func ToString(guid *windows.GUID) string {
+	return fmt.Sprintf("{%06X-%04X-%04X-%04X-%012X}", guid.Data1, guid.Data2, guid.Data3, guid.Data4[:2], guid.Data4[2:])
+}
diff --git a/tun/wintun/guid/mksyscall.go b/tun/wintun/guid/mksyscall.go
new file mode 100644
index 0000000..5c956cf
--- /dev/null
+++ b/tun/wintun/guid/mksyscall.go
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
+ */
+
+package guid
+
+//go:generate go run $GOROOT/src/syscall/mksyscall_windows.go -output zguid_windows.go guid_windows.go
diff --git a/tun/ztun_windows.go b/tun/wintun/guid/zguid_windows.go
index 9aa6e11..5467849 100644
--- a/tun/ztun_windows.go
+++ b/tun/wintun/guid/zguid_windows.go
@@ -1,6 +1,6 @@
 // Code generated by 'go generate'; DO NOT EDIT.
 
-package tun
+package guid
 
 import (
 	"syscall"
diff --git a/setupapi/mksyscall.go b/tun/wintun/setupapi/mksyscall.go
index 3447dee..3447dee 100644
--- a/setupapi/mksyscall.go
+++ b/tun/wintun/setupapi/mksyscall.go
diff --git a/setupapi/setupapi_windows.go b/tun/wintun/setupapi/setupapi_windows.go
index 72d4bd8..72d4bd8 100644
--- a/setupapi/setupapi_windows.go
+++ b/tun/wintun/setupapi/setupapi_windows.go
diff --git a/setupapi/setupapi_windows_test.go b/tun/wintun/setupapi/setupapi_windows_test.go
index e6b00c9..e6b00c9 100644
--- a/setupapi/setupapi_windows_test.go
+++ b/tun/wintun/setupapi/setupapi_windows_test.go
diff --git a/setupapi/types_windows.go b/tun/wintun/setupapi/types_windows.go
index c4aeff9..c4aeff9 100644
--- a/setupapi/types_windows.go
+++ b/tun/wintun/setupapi/types_windows.go
diff --git a/setupapi/zsetupapi_windows.go b/tun/wintun/setupapi/zsetupapi_windows.go
index 853b6a7..853b6a7 100644
--- a/setupapi/zsetupapi_windows.go
+++ b/tun/wintun/setupapi/zsetupapi_windows.go
diff --git a/setupapi/zsetupapi_windows_test.go b/tun/wintun/setupapi/zsetupapi_windows_test.go
index 09b9195..09b9195 100644
--- a/setupapi/zsetupapi_windows_test.go
+++ b/tun/wintun/setupapi/zsetupapi_windows_test.go
diff --git a/tun/wintun/wintun_windows.go b/tun/wintun/wintun_windows.go
new file mode 100644
index 0000000..1413c24
--- /dev/null
+++ b/tun/wintun/wintun_windows.go
@@ -0,0 +1,461 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
+ */
+
+package wintun
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"git.zx2c4.com/wireguard-go/tun/wintun/guid"
+	"git.zx2c4.com/wireguard-go/tun/wintun/setupapi"
+	"golang.org/x/sys/windows"
+	"golang.org/x/sys/windows/registry"
+)
+
+type Wintun windows.GUID
+
+var deviceClassNetGUID = windows.GUID{0x4d36e972, 0xe325, 0x11ce, [8]byte{0xbf, 0xc1, 0x08, 0x00, 0x2b, 0xe1, 0x03, 0x18}}
+
+const TUN_HWID = "Wintun"
+
+//
+// GetInterface finds interface ID by name.
+//
+// hwndParent is a handle to the top-level window to use for any user
+// interface that is related to non-device-specific actions (such as a select-
+// device dialog box that uses the global class driver list). This handle is
+// optional and can be 0. If a specific top-level window is not required, set
+// hwndParent to 0.
+//
+// Function returns interface ID when the interface was found, or nil
+// otherwise.
+//
+func GetInterface(ifname string, hwndParent uintptr) (*Wintun, error) {
+	// Create a list of network devices.
+	devInfoList, err := setupapi.SetupDiGetClassDevsEx(&deviceClassNetGUID, "", hwndParent, setupapi.DIGCF_PRESENT, setupapi.DevInfo(0), "")
+	if err != nil {
+		return nil, err
+	}
+	defer devInfoList.Close()
+
+	// Retrieve information associated with a device information set.
+	// TODO: Is this really necessary?
+	_, err = devInfoList.GetDeviceInfoListDetail()
+	if err != nil {
+		return nil, err
+	}
+
+	// TODO: If we're certain we want case-insensitive name comparison, please document the rationale.
+	ifname = strings.ToLower(ifname)
+
+	// Iterate.
+	for index := 0; ; index++ {
+		// Get the device from the list.
+		deviceData, err := devInfoList.EnumDeviceInfo(index)
+		if err != nil {
+			if errWin, ok := err.(syscall.Errno); ok && errWin == 259 /*ERROR_NO_MORE_ITEMS*/ {
+				break
+			}
+			// Something is wrong with this device. Skip it.
+			continue
+		}
+
+		// Get interface ID.
+		ifid, err := getInterfaceId(devInfoList, deviceData, 1)
+		if err != nil {
+			// Something is wrong with this device. Skip it.
+			continue
+		}
+
+		// Get interface name.
+		ifname2, err := ((*Wintun)(ifid)).GetInterfaceName()
+		if err != nil {
+			// Something is wrong with this device. Skip it.
+			continue
+		}
+
+		if ifname == strings.ToLower(ifname2) {
+			// Interface name found.
+			return (*Wintun)(ifid), nil
+		}
+	}
+
+	return nil, nil
+}
+
+//
+// CreateInterface creates a TUN interface.
+//
+// description is a string that supplies the text description of the device.
+// description is optional and can be "".
+//
+// hwndParent is a handle to the top-level window to use for any user
+// interface that is related to non-device-specific actions (such as a select-
+// device dialog box that uses the global class driver list). This handle is
+// optional and can be 0. If a specific top-level window is not required, set
+// hwndParent to 0.
+//
+// Function returns the network interface ID and a flag if reboot is required.
+//
+func CreateInterface(description string, hwndParent uintptr) (*Wintun, bool, error) {
+	// Create an empty device info set for network adapter device class.
+	devInfoList, err := setupapi.SetupDiCreateDeviceInfoListEx(&deviceClassNetGUID, hwndParent, "")
+	if err != nil {
+		return nil, false, err
+	}
+
+	// Get the device class name from GUID.
+	className, err := setupapi.SetupDiClassNameFromGuidEx(&deviceClassNetGUID, "")
+	if err != nil {
+		return nil, false, err
+	}
+
+	// Create a new device info element and add it to the device info set.
+	deviceData, err := devInfoList.CreateDeviceInfo(className, &deviceClassNetGUID, description, hwndParent, setupapi.DICD_GENERATE_ID)
+	if err != nil {
+		return nil, false, err
+	}
+
+	// Set a device information element as the selected member of a device information set.
+	err = devInfoList.SetSelectedDevice(deviceData)
+	if err != nil {
+		return nil, false, err
+	}
+
+	// Set Plug&Play device hardware ID property.
+	hwid, err := syscall.UTF16FromString(TUN_HWID)
+	if err != nil {
+		return nil, false, err
+	}
+	err = devInfoList.SetDeviceRegistryProperty(deviceData, setupapi.SPDRP_HARDWAREID, setupapi.UTF16ToBuf(append(hwid, 0)))
+	if err != nil {
+		return nil, false, err
+	}
+
+	// Search for the driver.
+	const driverType = setupapi.SPDIT_CLASSDRIVER
+	err = devInfoList.BuildDriverInfoList(deviceData, driverType)
+	if err != nil {
+		return nil, false, err
+	}
+	defer devInfoList.DestroyDriverInfoList(deviceData, driverType)
+
+	driverDate := windows.Filetime{}
+	driverVersion := uint64(0)
+	for index := 0; ; index++ {
+		// Get a driver from the list.
+		driverData, err := devInfoList.EnumDriverInfo(deviceData, driverType, index)
+		if err != nil {
+			if errWin, ok := err.(syscall.Errno); ok && errWin == 259 /*ERROR_NO_MORE_ITEMS*/ {
+				break
+			}
+			// Something is wrong with this driver. Skip it.
+			continue
+		}
+
+		// Check the driver version first, since the check is trivial and will save us iterating over hardware IDs for any driver versioned prior our best match.
+		if driverData.IsNewer(driverDate, driverVersion) {
+			// Get driver info details.
+			driverDetailData, err := devInfoList.GetDriverInfoDetail(deviceData, driverData)
+			if err != nil {
+				// Something is wrong with this driver. Skip it.
+				continue
+			}
+
+			if driverDetailData.IsCompatible(TUN_HWID) {
+				// Matching hardware ID found. Select the driver.
+				err := devInfoList.SetSelectedDriver(deviceData, driverData)
+				if err != nil {
+					// Something is wrong with this driver. Skip it.
+					continue
+				}
+
+				driverDate = driverData.DriverDate
+				driverVersion = driverData.DriverVersion
+			}
+		}
+	}
+
+	if driverVersion == 0 {
+		return nil, false, fmt.Errorf("No driver for device \"%v\" installed", TUN_HWID)
+	}
+
+	// Call appropriate class installer.
+	err = devInfoList.CallClassInstaller(setupapi.DIF_REGISTERDEVICE, deviceData)
+	if err != nil {
+		return nil, false, err
+	}
+
+	// Register device co-installers if any.
+	devInfoList.CallClassInstaller(setupapi.DIF_REGISTER_COINSTALLERS, deviceData)
+
+	// Install interfaces if any.
+	devInfoList.CallClassInstaller(setupapi.DIF_INSTALLINTERFACES, deviceData)
+
+	var ifid *windows.GUID
+	var rebootRequired bool
+
+	// Install the device.
+	err = devInfoList.CallClassInstaller(setupapi.DIF_INSTALLDEVICE, deviceData)
+	if err == nil {
+		// Check if a system reboot is required. (Ignore errors)
+		if ret, _ := checkReboot(devInfoList, deviceData); ret {
+			rebootRequired = true
+		}
+
+		// Get network interface ID from registry. Retry for max 30sec.
+		ifid, err = getInterfaceId(devInfoList, deviceData, 30)
+	}
+
+	if err == nil {
+		return (*Wintun)(ifid), rebootRequired, nil
+	}
+
+	// The interface failed to install, or the interface ID was unobtainable. Clean-up.
+	removeDeviceParams := setupapi.SP_REMOVEDEVICE_PARAMS{
+		ClassInstallHeader: setupapi.SP_CLASSINSTALL_HEADER{
+			InstallFunction: setupapi.DIF_REMOVE,
+		},
+		Scope: setupapi.DI_REMOVEDEVICE_GLOBAL,
+	}
+	removeDeviceParams.ClassInstallHeader.Size = uint32(unsafe.Sizeof(removeDeviceParams.ClassInstallHeader))
+
+	// Set class installer parameters for DIF_REMOVE.
+	if devInfoList.SetClassInstallParams(deviceData, &removeDeviceParams.ClassInstallHeader, uint32(unsafe.Sizeof(removeDeviceParams))) == nil {
+		// Call appropriate class installer.
+		if devInfoList.CallClassInstaller(setupapi.DIF_REMOVE, deviceData) == nil {
+			// Check if a system reboot is required. (Ignore errors)
+			if ret, _ := checkReboot(devInfoList, deviceData); ret {
+				rebootRequired = true
+			}
+		}
+	}
+
+	return nil, false, err
+}
+
+//
+// DeleteInterface deletes a TUN interface.
+//
+// hwndParent is a handle to the top-level window to use for any user
+// interface that is related to non-device-specific actions (such as a select-
+// device dialog box that uses the global class driver list). This handle is
+// optional and can be 0. If a specific top-level window is not required, set
+// hwndParent to 0.
+//
+// Function returns true if the interface was found and deleted and a flag if
+// reboot is required.
+//
+func (wintun *Wintun) DeleteInterface(hwndParent uintptr) (bool, bool, error) {
+	ifid := (*windows.GUID)(wintun)
+	// Create a list of network devices.
+	devInfoList, err := setupapi.SetupDiGetClassDevsEx(&deviceClassNetGUID, "", hwndParent, setupapi.DIGCF_PRESENT, setupapi.DevInfo(0), "")
+	if err != nil {
+		return false, false, err
+	}
+	defer devInfoList.Close()
+
+	// Retrieve information associated with a device information set.
+	// TODO: Is this really necessary?
+	_, err = devInfoList.GetDeviceInfoListDetail()
+	if err != nil {
+		return false, false, err
+	}
+
+	// Iterate.
+	for index := 0; ; index++ {
+		// Get the device from the list.
+		deviceData, err := devInfoList.EnumDeviceInfo(index)
+		if err != nil {
+			if errWin, ok := err.(syscall.Errno); ok && errWin == 259 /*ERROR_NO_MORE_ITEMS*/ {
+				break
+			}
+			// Something is wrong with this device. Skip it.
+			continue
+		}
+
+		// Get interface ID.
+		ifid2, err := getInterfaceId(devInfoList, deviceData, 1)
+		if err != nil {
+			// Something is wrong with this device. Skip it.
+			continue
+		}
+
+		if ifid == ifid2 {
+			// Remove the device.
+			removeDeviceParams := setupapi.SP_REMOVEDEVICE_PARAMS{
+				ClassInstallHeader: setupapi.SP_CLASSINSTALL_HEADER{
+					InstallFunction: setupapi.DIF_REMOVE,
+				},
+				Scope: setupapi.DI_REMOVEDEVICE_GLOBAL,
+			}
+			removeDeviceParams.ClassInstallHeader.Size = uint32(unsafe.Sizeof(removeDeviceParams.ClassInstallHeader))
+
+			// Set class installer parameters for DIF_REMOVE.
+			err = devInfoList.SetClassInstallParams(deviceData, &removeDeviceParams.ClassInstallHeader, uint32(unsafe.Sizeof(removeDeviceParams)))
+			if err != nil {
+				return false, false, err
+			}
+
+			// Call appropriate class installer.
+			err = devInfoList.CallClassInstaller(setupapi.DIF_REMOVE, deviceData)
+			if err != nil {
+				return false, false, err
+			}
+
+			// Check if a system reboot is required. (Ignore errors)
+			if ret, _ := checkReboot(devInfoList, deviceData); ret {
+				return true, true, nil
+			}
+
+			return true, false, nil
+		}
+	}
+
+	return false, false, nil
+}
+
+///
+/// checkReboot checks device install parameters if a system reboot is required.
+///
+func checkReboot(deviceInfoSet setupapi.DevInfo, deviceInfoData *setupapi.SP_DEVINFO_DATA) (bool, error) {
+	devInstallParams, err := deviceInfoSet.GetDeviceInstallParams(deviceInfoData)
+	if err != nil {
+		return false, err
+	}
+
+	if (devInstallParams.Flags & (setupapi.DI_NEEDREBOOT | setupapi.DI_NEEDRESTART)) != 0 {
+		return true, nil
+	}
+
+	return false, nil
+}
+
+// getInterfaceId returns network interface ID.
+//
+// After the device is created, it might take some time before the registry
+// key is populated. numAttempts parameter specifies the number of attempts
+// to read NetCfgInstanceId value from registry. A 1sec sleep is inserted
+// between retry attempts.
+//
+// Function returns the network interface ID.
+//
+func getInterfaceId(deviceInfoSet setupapi.DevInfo, deviceInfoData *setupapi.SP_DEVINFO_DATA, numAttempts int) (*windows.GUID, error) {
+	if numAttempts < 1 {
+		return nil, fmt.Errorf("Invalid numAttempts (expected: >=1, provided: %v)", numAttempts)
+	}
+
+	// Open HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\<class>\<id> registry key.
+	key, err := deviceInfoSet.OpenDevRegKey(deviceInfoData, setupapi.DICS_FLAG_GLOBAL, 0, setupapi.DIREG_DRV, registry.READ)
+	if err != nil {
+		return nil, errors.New("Device-specific registry key open failed: " + err.Error())
+	}
+	defer key.Close()
+
+	for {
+		// Query the NetCfgInstanceId value. Using get_reg_string() right on might clutter the output with error messages while the registry is still being populated.
+		_, _, err = key.GetValue("NetCfgInstanceId", nil)
+		if err != nil {
+			if errWin, ok := err.(syscall.Errno); ok && errWin == windows.ERROR_FILE_NOT_FOUND {
+				numAttempts--
+				if numAttempts > 0 {
+					// Wait and retry.
+					// TODO: Wait for a cancellable event instead.
+					time.Sleep(1000 * time.Millisecond)
+					continue
+				}
+			}
+
+			return nil, errors.New("RegQueryValueEx(\"NetCfgInstanceId\") failed: " + err.Error())
+		}
+
+		// Read the NetCfgInstanceId value now.
+		value, err := getRegStringValue(key, "NetCfgInstanceId")
+		if err != nil {
+			return nil, errors.New("RegQueryStringValue(\"NetCfgInstanceId\") failed: " + err.Error())
+		}
+
+		// Convert to windows.GUID.
+		ifid, err := guid.FromString(value)
+		if err != nil {
+			return nil, fmt.Errorf("NetCfgInstanceId registry value is not a GUID (expected: \"{...}\", provided: \"%v\")", value)
+		}
+
+		return ifid, err
+	}
+}
+
+//
+// GetInterfaceName returns network interface name.
+//
+func (wintun *Wintun) GetInterfaceName() (string, error) {
+	ifid := (*windows.GUID)(wintun)
+	// Open network interface registry key.
+	key, err := registry.OpenKey(registry.LOCAL_MACHINE, fmt.Sprintf("SYSTEM\\CurrentControlSet\\Control\\Network\\%v\\%v\\Connection", guid.ToString(&deviceClassNetGUID), guid.ToString(ifid)), registry.QUERY_VALUE)
+	if err != nil {
+		return "", errors.New("Network-specific registry key open failed: " + err.Error())
+	}
+	defer key.Close()
+
+	// Get the interface name.
+	return getRegStringValue(key, "Name")
+}
+
+//
+// SetInterfaceName sets network interface name.
+//
+func (wintun *Wintun) SetInterfaceName(ifname string) error {
+	ifid := (*windows.GUID)(wintun)
+	// Open network interface registry key.
+	key, err := registry.OpenKey(registry.LOCAL_MACHINE, fmt.Sprintf("SYSTEM\\CurrentControlSet\\Control\\Network\\%v\\%v\\Connection", guid.ToString(&deviceClassNetGUID), guid.ToString(ifid)), registry.SET_VALUE)
+	if err != nil {
+		return errors.New("Network-specific registry key open failed: " + err.Error())
+	}
+	defer key.Close()
+
+	// Set the interface name.
+	return key.SetStringValue("Name", ifname)
+}
+
+//
+// getRegStringValue function reads a string value from registry.
+//
+// If the value type is REG_EXPAND_SZ the environment variables are expanded.
+// Should expanding fail, original string value and nil error are returned.
+//
+func getRegStringValue(key registry.Key, name string) (string, error) {
+	// Read string value.
+	value, valueType, err := key.GetStringValue(name)
+	if err != nil {
+		return "", err
+	}
+
+	if valueType != registry.EXPAND_SZ {
+		// Value does not require expansion.
+		return value, nil
+	}
+
+	valueExp, err := registry.ExpandString(value)
+	if err != nil {
+		// Expanding failed: return original sting value.
+		return value, nil
+	}
+
+	// Return expanded value.
+	return valueExp, nil
+}
+
+func (wintun *Wintun) SignalEventName() string {
+	return fmt.Sprintf("Global\\WINTUN_EVENT_%s", guid.ToString((*windows.GUID)(wintun)))
+}
+
+func (wintun *Wintun) DataFileName() string {
+	return fmt.Sprintf("\\\\.\\Global\\WINTUN_DEVICE_%s", guid.ToString((*windows.GUID)(wintun)))
+}
\ No newline at end of file