macOS: Detect when updating from the App Store

And show an alert when tunnels are active during updation -- that
might cause the update to not work correctly.

Signed-off-by: Roopesh Chander <roop@roopc.net>

4 files changed, 80 insertions, 0 deletions

diff --git a/WireGuard/WireGuard/Base.lproj/Localizable.strings b/WireGuard/WireGuard/Base.lproj/Localizable.strings
index 8600a63..9cfaef1 100644
--- a/WireGuard/WireGuard/Base.lproj/Localizable.strings
+++ b/WireGuard/WireGuard/Base.lproj/Localizable.strings
@@ -405,3 +405,9 @@
 "macUnusableTunnelMessage" = "The configuration for this tunnel cannot be found in the keychain.";
 "macUnusableTunnelInfo" = "In case this tunnel was created by another user, only that user can view, edit, or activate this tunnel.";
 "macUnusableTunnelButtonTitleDeleteTunnel" = "Delete tunnel";
+
+// Mac App Store updating alert
+
+"macAppStoreUpdatingAlertMessage" = "App Store would like to update WireGuard";
+"macAppStoreUpdatingAlertInfoWithOnDemand (%@)" = "Please disable on-demand for tunnel ‘%@’, deactivate it, and then continue updating in App Store.";
+"macAppStoreUpdatingAlertInfoWithoutOnDemand (%@)" = "Please deactivate tunnel ‘%@’ and then continue updating in App Store.";
diff --git a/WireGuard/WireGuard/UI/macOS/AppDelegate.swift b/WireGuard/WireGuard/UI/macOS/AppDelegate.swift
index e80d971..3e98c20 100644
--- a/WireGuard/WireGuard/UI/macOS/AppDelegate.swift
+++ b/WireGuard/WireGuard/UI/macOS/AppDelegate.swift
@@ -68,6 +68,36 @@ class AppDelegate: NSObject, NSApplicationDelegate {
             NSApp.terminate(nil)
         }
     }
+
+    func applicationShouldTerminate(_ sender: NSApplication) -> NSApplication.TerminateReply {
+        if UserDefaults.standard.bool(forKey: "shouldSuppressAppStoreUpdateDetection") {
+            wg_log(.debug, staticMessage: "App Store update detection is suppressed")
+            return .terminateNow
+        }
+        guard let currentTunnel = tunnelsTracker?.currentTunnel, currentTunnel.status == .active || currentTunnel.status == .activating else {
+            return .terminateNow
+        }
+        guard let appleEvent = NSAppleEventManager.shared().currentAppleEvent else {
+            return .terminateNow
+        }
+        guard MacAppStoreUpdateDetector.isUpdatingFromMacAppStore(quitAppleEvent: appleEvent) else {
+            return .terminateNow
+        }
+        let alert = NSAlert()
+        alert.messageText = tr("macAppStoreUpdatingAlertMessage")
+        if currentTunnel.isActivateOnDemandEnabled {
+            alert.informativeText = tr(format: "macAppStoreUpdatingAlertInfoWithOnDemand (%@)", currentTunnel.name)
+        } else {
+            alert.informativeText = tr(format: "macAppStoreUpdatingAlertInfoWithoutOnDemand (%@)", currentTunnel.name)
+        }
+        NSApp.activate(ignoringOtherApps: true)
+        if let manageWindow = manageTunnelsWindowObject {
+            alert.beginSheetModal(for: manageWindow) { _ in }
+        } else {
+            alert.runModal()
+        }
+        return .terminateCancel
+    }
 }
 
 extension AppDelegate: StatusMenuWindowDelegate {
diff --git a/WireGuard/WireGuard/UI/macOS/MacAppStoreUpdateDetector.swift b/WireGuard/WireGuard/UI/macOS/MacAppStoreUpdateDetector.swift
new file mode 100644
index 0000000..7fbb011
--- /dev/null
+++ b/WireGuard/WireGuard/UI/macOS/MacAppStoreUpdateDetector.swift
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: MIT
+// Copyright © 2018-2019 WireGuard LLC. All Rights Reserved.
+
+import Cocoa
+
+class MacAppStoreUpdateDetector {
+    static func isUpdatingFromMacAppStore(quitAppleEvent: NSAppleEventDescriptor) -> Bool {
+        guard isQuitEvent(quitAppleEvent) else { return false }
+        guard let senderPIDDescriptor = quitAppleEvent.attributeDescriptor(forKeyword: keySenderPIDAttr) else { return false }
+        let pid = senderPIDDescriptor.int32Value
+        guard let executablePath = getExecutablePath(from: pid) else { return false }
+        wg_log(.debug, message: "aevt/quit Apple event received from: \(executablePath)")
+        if executablePath.hasPrefix("/System/Library/") {
+            let executableName = URL(fileURLWithPath: executablePath, isDirectory: false).lastPathComponent
+            return executableName == "com.apple.CommerceKit.StoreAEService"
+        }
+        return false
+    }
+}
+
+private func isQuitEvent(_ event: NSAppleEventDescriptor) -> Bool {
+    if let eventClassDescriptor = event.attributeDescriptor(forKeyword: keyEventClassAttr),
+        let eventIdDescriptor = event.attributeDescriptor(forKeyword: keyEventIDAttr) {
+        return eventClassDescriptor.typeCodeValue == kCoreEventClass && eventIdDescriptor.typeCodeValue == kAEQuitApplication
+    }
+    return false
+}
+
+private func getExecutablePath(from pid: pid_t) -> String? {
+    let bufferSize = Int(PATH_MAX)
+    var buffer = Data(capacity: bufferSize)
+    return buffer.withUnsafeMutableBytes { (ptr: UnsafeMutableRawBufferPointer) -> String? in
+        if let basePtr = ptr.baseAddress {
+            let byteCount = proc_pidpath(pid, basePtr, UInt32(bufferSize))
+            return byteCount > 0 ? String(cString: basePtr.bindMemory(to: CChar.self, capacity: bufferSize)) : nil
+        }
+        return nil
+    }
+}
diff --git a/WireGuard/WireGuard/WireGuard-Bridging-Header.h b/WireGuard/WireGuard/WireGuard-Bridging-Header.h
index 210b3df..81766ab 100644
--- a/WireGuard/WireGuard/WireGuard-Bridging-Header.h
+++ b/WireGuard/WireGuard/WireGuard-Bridging-Header.h
@@ -5,3 +5,8 @@
 #include "ringlogger.h"
 #include "highlighter.h"
 #include "key.h"
+
+#import "TargetConditionals.h"
+#if TARGET_OS_OSX
+#include <libproc.h>
+#endif