From 274d32d0aa5bc7c8bc6a908590dcbc8741fd8872 Mon Sep 17 00:00:00 2001
From: Aleksandar Pesic <peske.nis@gmail.com>
Date: Fri, 4 Dec 2020 14:56:34 +0100
Subject: [PATCH] Prepare for the new wireguard-go API.

Signed-off-by: Aleksandar Pesic <peske.nis@gmail.com>
---
 wgengine/router/ifconfig_windows.go | 35 +++++++++++++----------------
 wgengine/router/router_windows.go   |  9 ++++++--
 2 files changed, 23 insertions(+), 21 deletions(-)

diff --git a/wgengine/router/ifconfig_windows.go b/wgengine/router/ifconfig_windows.go
index ee4a62b13..2bbd29eb9 100644
--- a/wgengine/router/ifconfig_windows.go
+++ b/wgengine/router/ifconfig_windows.go
@@ -39,12 +39,8 @@ import (
 // address a few rare corner cases, but is unlikely to significantly
 // help with MTU issues compared to a static 1280B implementation.
 func monitorDefaultRoutes(tun *tun.NativeTun) (*winipcfg.RouteChangeCallback, error) {
-	guid := tun.GUID()
-	ourLuid, err := winipcfg.LUIDFromGUID(&guid)
+	ourLuid := winipcfg.LUID(tun.LUID())
 	lastMtu := uint32(0)
-	if err != nil {
-		return nil, fmt.Errorf("error mapping GUID %v to LUID: %w", guid, err)
-	}
 	doIt := func() error {
 		mtu, err := getDefaultRouteMTU()
 		if err != nil {
@@ -91,7 +87,7 @@ func monitorDefaultRoutes(tun *tun.NativeTun) (*winipcfg.RouteChangeCallback, er
 		}
 		return nil
 	}
-	err = doIt()
+	err := doIt()
 	if err != nil {
 		return nil, err
 	}
@@ -159,7 +155,7 @@ func getDefaultRouteMTU() (uint32, error) {
 
 // setPrivateNetwork marks the provided network adapter's category to private.
 // It returns (false, nil) if the adapter was not found.
-func setPrivateNetwork(ifcGUID *windows.GUID) (bool, error) {
+func setPrivateNetwork(ifcLUID winipcfg.LUID) (bool, error) {
 	// NLM_NETWORK_CATEGORY values.
 	const (
 		categoryPublic  = 0
@@ -167,6 +163,11 @@ func setPrivateNetwork(ifcGUID *windows.GUID) (bool, error) {
 		categoryDomain  = 2
 	)
 
+	ifcGUID, err := ifcLUID.GUID()
+	if err != nil {
+		return false, fmt.Errorf("ifcLUID.GUID: %v", err)
+	}
+
 	// Lock OS thread when using OLE, which seems to be a requirement
 	// from the Microsoft docs. go-ole doesn't seem to handle it automatically.
 	// https://github.com/tailscale/tailscale/issues/921#issuecomment-727526807
@@ -222,12 +223,8 @@ func setPrivateNetwork(ifcGUID *windows.GUID) (bool, error) {
 	return false, nil
 }
 
-// interfaceFromGUID returns IPAdapterAddresses with specified GUID.
-func interfaceFromGUID(guid *windows.GUID, flags winipcfg.GAAFlags) (*winipcfg.IPAdapterAddresses, error) {
-	luid, err := winipcfg.LUIDFromGUID(guid)
-	if err != nil {
-		return nil, err
-	}
+// interfaceFromLUID returns IPAdapterAddresses with specified GUID.
+func interfaceFromLUID(luid winipcfg.LUID, flags winipcfg.GAAFlags) (*winipcfg.IPAdapterAddresses, error) {
 	addresses, err := winipcfg.GetAdaptersAddresses(windows.AF_UNSPEC, flags)
 	if err != nil {
 		return nil, err
@@ -237,13 +234,13 @@ func interfaceFromGUID(guid *windows.GUID, flags winipcfg.GAAFlags) (*winipcfg.I
 			return addr, nil
 		}
 	}
-	return nil, fmt.Errorf("interfaceFromGUID: interface with LUID %v (from GUID %v) not found", luid, guid)
+	return nil, fmt.Errorf("interfaceFromLUID: interface with LUID %v not found", luid)
 }
 
 func configureInterface(cfg *Config, tun *tun.NativeTun) error {
 	const mtu = 0
-	guid := tun.GUID()
-	iface, err := interfaceFromGUID(&guid,
+	luid := winipcfg.LUID(tun.LUID())
+	iface, err := interfaceFromLUID(luid,
 		// Issue 474: on early boot, when the network is still
 		// coming up, if the Tailscale service comes up first,
 		// the Tailscale adapter it finds might not have the
@@ -260,7 +257,7 @@ func configureInterface(cfg *Config, tun *tun.NativeTun) error {
 		// does.
 		const tries = 20
 		for i := 0; i < tries; i++ {
-			found, err := setPrivateNetwork(&guid)
+			found, err := setPrivateNetwork(luid)
 			if err != nil {
 				log.Printf("setPrivateNetwork(try=%d): %v", i, err)
 			} else {
@@ -271,7 +268,7 @@ func configureInterface(cfg *Config, tun *tun.NativeTun) error {
 			}
 			time.Sleep(1 * time.Second)
 		}
-		log.Printf("setPrivateNetwork: adapter %v not found after %d tries, giving up", guid, tries)
+		log.Printf("setPrivateNetwork: adapter LUID %v not found after %d tries, giving up", luid, tries)
 	}()
 
 	var firstGateway4 *net.IP
@@ -353,7 +350,7 @@ func configureInterface(cfg *Config, tun *tun.NativeTun) error {
 	}
 
 	// Re-read interface after syncAddresses.
-	iface, err = interfaceFromGUID(&guid,
+	iface, err = interfaceFromLUID(luid,
 		// Issue 474: on early boot, when the network is still
 		// coming up, if the Tailscale service comes up first,
 		// the Tailscale adapter it finds might not have the
diff --git a/wgengine/router/router_windows.go b/wgengine/router/router_windows.go
index 50e65dd32..0194ef0a1 100644
--- a/wgengine/router/router_windows.go
+++ b/wgengine/router/router_windows.go
@@ -37,10 +37,15 @@ func newUserspaceRouter(logf logger.Logf, wgdev *device.Device, tundev tun.Devic
 	}
 
 	nativeTun := tundev.(*tun.NativeTun)
-	guid := nativeTun.GUID().String()
+	luid := winipcfg.LUID(nativeTun.LUID())
+	guid, err := luid.GUID()
+	if err != nil {
+		return nil, err
+	}
+
 	mconfig := dns.ManagerConfig{
 		Logf:          logf,
-		InterfaceName: guid,
+		InterfaceName: guid.String(),
 	}
 
 	return &winRouter{