log machine id mappings for VS to VS Code (#11308)

* log machine id mappings for VS to VS Code

* update comment

* in case execChildProcess throws

Extension/src/id.ts

@@ -0,0 +1,68 @@
+/* --------------------------------------------------------------------------------------------
+ * Copyright (c) Microsoft Corporation. All Rights Reserved.
+ * See 'LICENSE' in the project root for license information.
+ * ------------------------------------------------------------------------------------------ */
+
+import { execChildProcess } from './common';
+import { isWindows } from './constants';
+import { logLanguageServerEvent } from './telemetry';
+
+/**
+ * Hash the MAC addresses on the machine (Windows-only) and log telemetry.
+ */
+export async function logMachineIdMappings(): Promise<void> {
+    if (!isWindows) {
+        return;
+    }
+
+    const macAddresses = await getMacAddresses();
+
+    // The first MAC address is the one Visual Studio uses
+    const primary = await getMachineId(macAddresses.shift());
+    if (primary) {
+        logLanguageServerEvent('machineIdMap', {primary});
+    }
+
+    // VS Code uses os.networkInterfaces() which has different sorting and availability,
+    // but all MAC addresses are returned by getmac.exe. The ID VS Code uses may change
+    // based on changes to the network configuration. Log the extras so we can assess
+    // how frequently this impacts the machine id.
+    for (const macAddress of macAddresses) {
+        const additional = await getMachineId(macAddress);
+        if (additional) {
+            logLanguageServerEvent('machineIdMap', {additional});
+        }
+    }
+}
+
+/**
+ * Parse the output of getmac.exe to get the list of MAC addresses for the PC.
+ */
+async function getMacAddresses(): Promise<string[]> {
+    try {
+        const output = await execChildProcess('getmac');
+        const regex = /(?:[a-z0-9]{2}[:\-]){5}[a-z0-9]{2}/gmi;
+        return output.match(regex) ?? [];
+    } catch (err) {
+        return [];
+    }
+}
+
+/**
+ * Code below is adapted from:
+ *  - vscode\src\vs\base\node\id.ts
+ */
+
+async function getMachineId(macAddress?: string): Promise<string | undefined> {
+    if (!macAddress) {
+        return undefined;
+    }
+
+    try {
+        const crypto = await import('crypto');
+        const normalized = macAddress.toUpperCase().replace(/:/g, '-');
+        return crypto.createHash('sha256').update(normalized, 'utf8').digest('hex');
+    } catch (err) {
+        return undefined;
+    }
+}

Extension/src/main.ts

@@ -22,6 +22,7 @@ import { PersistentState } from './LanguageServer/persistentState';
 import { CppSettings } from './LanguageServer/settings';
 import { logAndReturn, returns } from './Utility/Async/returns';
 import { CppTools1 } from './cppTools1';
+import { logMachineIdMappings } from './id';
 import { disposeOutputChannels, log } from './logger';
 import { PlatformInformation } from './platform';
 
@@ -214,6 +215,7 @@ function sendTelemetry(info: PlatformInformation): void {
             break;
     }
     Telemetry.logDebuggerEvent("acquisition", telemetryProperties);
+    logMachineIdMappings().catch(logAndReturn.undefined);
 }
 
 async function checkVsixCompatibility(): Promise<void> {