From: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri, 22 Mar 2019 22:48:40 +0000 (-0600)
Subject: wintun: query for NetCfgInstanceId several times
X-Git-Tag: 0.0.20190409~8
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2fa80c0cb7453ab830355b4c612192ec3064865c;p=thirdparty%2Fwireguard-go.git

wintun: query for NetCfgInstanceId several times
---

diff --git a/tun/wintun/wintun_windows.go b/tun/wintun/wintun_windows.go
index f2f3684..ba94b11 100644
--- a/tun/wintun/wintun_windows.go
+++ b/tun/wintun/wintun_windows.go
@@ -45,14 +45,25 @@ func MakeWintun(deviceInfoSet setupapi.DevInfo, deviceInfoData *setupapi.DevInfo
 	}
 	defer key.Close()
 
-	// Read the NetCfgInstanceId value.
-	valueStr, valueType, err := key.GetStringValue("NetCfgInstanceId")
+	var valueStr string
+	var valueType uint32
+
+	//TODO: Figure out a way to not need to loop like this.
+	for i := 0; i < 30; i++ {
+		// Read the NetCfgInstanceId value.
+		valueStr, valueType, err = key.GetStringValue("NetCfgInstanceId")
+		if err != nil {
+			time.Sleep(time.Millisecond * 100)
+			continue
+		}
+		if valueType != registry.SZ {
+			return nil, fmt.Errorf("NetCfgInstanceId registry value is not REG_SZ (expected: %v, provided: %v)", registry.SZ, valueType)
+		}
+		break
+	}
 	if err != nil {
 		return nil, errors.New("RegQueryStringValue(\"NetCfgInstanceId\") failed: " + err.Error())
 	}
-	if valueType != registry.SZ {
-		return nil, fmt.Errorf("NetCfgInstanceId registry value is not REG_SZ (expected: %v, provided: %v)", registry.SZ, valueType)
-	}
 
 	// Convert to windows.GUID.
 	ifid, err := guid.FromString(valueStr)