From: Avery Pennarun <apenwarr@gmail.com>
Date: Fri, 5 Apr 2019 06:26:40 +0000 (-0400)
Subject: wintun: quickly ignore non-Wintun devices
X-Git-Tag: 0.0.20200121~13
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c85e4a410f27986a2967a49c0155633c716bf3ca;p=thirdparty%2Fwireguard-go.git

wintun: quickly ignore non-Wintun devices

Some devices take ~2 seconds to enumerate on Windows if we try to get
their instance name.  The hardware id property, on the other hand,
is available right away.

Signed-off-by: Avery Pennarun <apenwarr@gmail.com>
[zx2c4: inlined this to where it makes sense, reused setupapi const]
---

diff --git a/tun/wintun/wintun_windows.go b/tun/wintun/wintun_windows.go
index e6dc141..a49242f 100644
--- a/tun/wintun/wintun_windows.go
+++ b/tun/wintun/wintun_windows.go
@@ -131,6 +131,15 @@ func (pool Pool) GetInterface(ifname string) (*Interface, error) {
 			continue
 		}
 
+		// Check the Hardware ID to make sure it's a real Wintun device first. This avoids doing slow operations on non-Wintun devices.
+		property, err := devInfoList.DeviceRegistryProperty(deviceData, setupapi.SPDRP_HARDWAREID)
+		if err != nil {
+			continue
+		}
+		if hwids, ok := property.([]string); ok && len(hwids) > 0 && hwids[0] != hardwareID {
+			continue
+		}
+
 		wintun, err := makeWintun(devInfoList, deviceData, pool)
 		if err != nil {
 			continue
@@ -494,6 +503,15 @@ func (pool Pool) DeleteMatchingInterfaces(matches func(wintun *Interface) bool)
 			continue
 		}
 
+		// Check the Hardware ID to make sure it's a real Wintun device first. This avoids doing slow operations on non-Wintun devices.
+		property, err := devInfoList.DeviceRegistryProperty(deviceData, setupapi.SPDRP_HARDWAREID)
+		if err != nil {
+			continue
+		}
+		if hwids, ok := property.([]string); ok && len(hwids) > 0 && hwids[0] != hardwareID {
+			continue
+		}
+
 		err = devInfoList.BuildDriverInfoList(deviceData, setupapi.SPDIT_COMPATDRIVER)
 		if err != nil {
 			continue