tor: tear down client deterministically on stop (ENV-3101)

CHANGELOG.md

@@ -4,6 +4,13 @@ SPDX-FileCopyrightText: 2024 Foundation Devices Inc.
 SPDX-License-Identifier: MIT
 -->
 
+## 0.2.1
+
+* Tear down the Tor client deterministically on `stop()`: await the proxy
+  accept loop, cancel accepted connections, and dispose the Rust client
+  instead of waiting for Dart GC, which left `tor_cache/dir.lock` held and
+  forced a restarted client's directory store into silent read-only mode.
+
 ## 0.0.9
 
 * Bumped arti to version 1.4.3

example/pubspec.lock

@@ -398,7 +398,7 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "0.2.0"
+    version: "0.2.1"
   typed_data:
     dependency: transitive
     description:

ios/tor/rust_lib_tor.xcframework/Info.plist

@@ -8,32 +8,32 @@
 			<key>BinaryPath</key>
 			<string>rust_lib_tor.framework/rust_lib_tor</string>
 			<key>LibraryIdentifier</key>
-			<string>ios-arm64</string>
+			<string>ios-arm64_x86_64-simulator</string>
 			<key>LibraryPath</key>
 			<string>rust_lib_tor.framework</string>
 			<key>SupportedArchitectures</key>
 			<array>
 				<string>arm64</string>
+				<string>x86_64</string>
 			</array>
 			<key>SupportedPlatform</key>
 			<string>ios</string>
+			<key>SupportedPlatformVariant</key>
+			<string>simulator</string>
 		</dict>
 		<dict>
 			<key>BinaryPath</key>
 			<string>rust_lib_tor.framework/rust_lib_tor</string>
 			<key>LibraryIdentifier</key>
-			<string>ios-arm64_x86_64-simulator</string>
+			<string>ios-arm64</string>
 			<key>LibraryPath</key>
 			<string>rust_lib_tor.framework</string>
 			<key>SupportedArchitectures</key>
 			<array>
 				<string>arm64</string>
-				<string>x86_64</string>
 			</array>
 			<key>SupportedPlatform</key>
 			<string>ios</string>
-			<key>SupportedPlatformVariant</key>
-			<string>simulator</string>
 		</dict>
 	</array>
 	<key>CFBundlePackageType</key>

ios/tor/rust_lib_tor.xcframework/ios-arm64/rust_lib_tor.framework/Info.plist

@@ -15,7 +15,7 @@
   <key>CFBundlePackageType</key>
   <string>FMWK</string>
   <key>CFBundleShortVersionString</key>
-  <string>0.2.0</string>
+  <string>0.2.1</string>
   <key>CFBundleSupportedPlatforms</key>
   <array>
     <string>iPhoneOS</string>

ios/tor/rust_lib_tor.xcframework/ios-arm64_x86_64-simulator/rust_lib_tor.framework/Info.plist

@@ -15,7 +15,7 @@
   <key>CFBundlePackageType</key>
   <string>FMWK</string>
   <key>CFBundleShortVersionString</key>
-  <string>0.2.0</string>
+  <string>0.2.1</string>
   <key>CFBundleSupportedPlatforms</key>
   <array>
     <string>iPhoneSimulator</string>

lib/tor.dart

@@ -48,8 +48,7 @@ class Tor {
   bool _started = false;
 
   /// True while the client is starting or re-bootstrapping.
-  bool get starting =>
-      _startInFlight != null || _bootstrapInFlight != null;
+  bool get starting => _startInFlight != null || _bootstrapInFlight != null;
 
   Future<void>? _startInFlight;
   Future<void>? _bootstrapInFlight;
@@ -197,6 +196,9 @@ class Tor {
       _client = torInstance.client;
       _proxy = torInstance.proxy;
       _proxyPort = torInstance.socksPort;
+      // The getters above clone; free the container now instead of at GC so
+      // it cannot keep an extra client reference (and dir.lock) alive.
+      torInstance.dispose();
       _started = true;
       _bootstrapped = true; // startTor creates a bootstrapped client
 
@@ -258,6 +260,7 @@ class Tor {
   /// Stops the proxy
   Future<void> stop() async {
     final proxy = _proxy;
+    final client = _client;
 
     // Stop publishing the route before awaiting native shutdown so callers
     // cannot start new work against a proxy that is being torn down.
@@ -268,22 +271,14 @@ class Tor {
     _bootstrapped = false;
     broadcastState();
 
-    if (proxy == null) {
-      return;
-    }
-
     try {
-      // This is now safe! FRB catches any panic and throws PanicException
-      await rust.stopProxy(proxy: proxy);
-    } on rust.TorError catch (e) {
-      if (kDebugMode) {
-        print('Error stopping proxy: $e');
-      }
-    } on PanicException catch (e) {
-      // Previously this would SIGABRT the app, now it's catchable!
-      if (kDebugMode) {
-        print('Proxy stop panicked (caught safely): ${e.message}');
+      if (proxy != null) {
+        await rust.stopProxy(proxy: proxy);
       }
+    } finally {
+      // Drop the Rust client now instead of at GC: a lingering client holds
+      // tor_cache/dir.lock, forcing a restarted client's dirmgr into read-only.
+      client?.dispose();
     }
   }
 

pubspec.yaml

@@ -4,7 +4,7 @@
 
 name: tor
 description: A multi-platform Flutter plugin for managing a Tor proxy. Based on arti.
-version: 0.2.0
+version: 0.2.1
 homepage: https://github.com/Foundation-Devices/tor
 
 environment:

rust/Cargo.toml

@@ -4,7 +4,7 @@
 
 [package]
 name = "rust_lib_tor"
-version = "0.2.0"
+version = "0.2.1"
 authors = ["Igor Cota <igor@foundation.xyz>"]
 edition = "2021"
 
@@ -13,8 +13,10 @@ crate-type = ["cdylib", "staticlib", "rlib"]
 
 [dependencies]
 flutter_rust_bridge = "=2.11.1"
+futures = "0.3"
 lazy_static = "1.4"
 tokio = { version = "1", features = ["full"] }
+tokio-util = { version = "0.7", features = ["rt"] }
 libc = "0.2"
 liblzma = { version = "0.4.7", features = ["static"] }
 arti-client = { version = "0.44.0", features = ["static", "onion-service-client"] }
@@ -27,6 +29,9 @@ anyhow = "1.0.79"
 time = "0.3.36"
 thiserror = "1.0"
 
+[dev-dependencies]
+tempfile = "3"
+
 [target.'cfg(target_os = "ios")'.dependencies]
 # Specific version for iOS
 security-framework = "=2.10.0"