feat(flutter_tools): Added proxy validator IPV6 loopback check (#95159)

* feat(flutter_tools): Added proxy validator IPV6 lookback check

* Remove whitespace.
Co-authored-by: Zachary Anderson <zanderso@users.noreply.github.com>

packages/flutter_tools/lib/src/proxy_validator.dart

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'base/io.dart';
 import 'base/platform.dart';
 import 'doctor_validator.dart';
 
@@ -43,7 +44,7 @@ class ProxyValidator extends DoctorValidator {
       else
         ...<ValidationMessage>[
           ValidationMessage('NO_PROXY is $_noProxy'),
-          for (String host in const <String>['127.0.0.1', 'localhost'])
+          for (final String host in await _getLoopbackAddresses())
             if (_noProxy.contains(host))
               ValidationMessage('NO_PROXY contains $host')
             else
@@ -59,4 +60,21 @@ class ProxyValidator extends DoctorValidator {
       messages,
     );
   }
+
+  Future<List<String>> _getLoopbackAddresses() async {
+    final List<String> loopBackAddresses = <String>['localhost'];
+
+    final List<NetworkInterface> networkInterfaces =
+      await listNetworkInterfaces(includeLinkLocal: true, includeLoopback: true);
+
+    for (final NetworkInterface networkInterface in networkInterfaces) {
+      for (final InternetAddress internetAddress in networkInterface.addresses) {
+        if (internetAddress.isLoopback) {
+          loopBackAddresses.add(internetAddress.address);
+        }
+      }
+    }
+
+    return loopBackAddresses;
+  }
 }

packages/flutter_tools/test/commands.shard/hermetic/proxy_validator_test.dart

@@ -2,6 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:io' as io;
+import 'dart:typed_data';
+
+import 'package:flutter_tools/src/base/io.dart';
 import 'package:flutter_tools/src/base/platform.dart';
 import 'package:flutter_tools/src/doctor_validator.dart';
 import 'package:flutter_tools/src/proxy_validator.dart';
@@ -9,6 +13,30 @@ import 'package:flutter_tools/src/proxy_validator.dart';
 import '../../src/common.dart';
 
 void main() {
+  setUp(() {
+    setNetworkInterfaceLister(
+      ({
+        bool includeLoopback = true,
+        bool includeLinkLocal = true,
+        InternetAddressType type = InternetAddressType.any,
+      }) async {
+        final List<FakeNetworkInterface> interfaces = <FakeNetworkInterface>[
+          FakeNetworkInterface(<FakeInternetAddress>[
+            const FakeInternetAddress('127.0.0.1')
+          ]),
+          FakeNetworkInterface(<FakeInternetAddress>[
+            const FakeInternetAddress('::1')
+          ])
+        ];
+
+        return Future<List<NetworkInterface>>.value(interfaces);
+    });
+  });
+
+  tearDown(() {
+    resetNetworkInterfaceLister();
+  });
+
   testWithoutContext('ProxyValidator does not show if HTTP_PROXY is not set', () {
     final Platform platform = FakePlatform(environment: <String, String>{});
 
@@ -37,16 +65,17 @@ void main() {
     final Platform platform = FakePlatform(
       environment: <String, String>{
         'HTTP_PROXY': 'fakeproxy.local',
-        'NO_PROXY': 'localhost,127.0.0.1',
+        'NO_PROXY': 'localhost,127.0.0.1,::1',
       },
     );
     final ValidationResult results = await ProxyValidator(platform: platform).validate();
 
     expect(results.messages, const <ValidationMessage>[
       ValidationMessage('HTTP_PROXY is set'),
-      ValidationMessage('NO_PROXY is localhost,127.0.0.1'),
-      ValidationMessage('NO_PROXY contains 127.0.0.1'),
+      ValidationMessage('NO_PROXY is localhost,127.0.0.1,::1'),
       ValidationMessage('NO_PROXY contains localhost'),
+      ValidationMessage('NO_PROXY contains 127.0.0.1'),
+      ValidationMessage('NO_PROXY contains ::1'),
     ]);
   });
 
@@ -54,16 +83,17 @@ void main() {
     final Platform platform = FakePlatform(
       environment: <String, String>{
         'http_proxy': 'fakeproxy.local',
-        'no_proxy': 'localhost,127.0.0.1',
+        'no_proxy': 'localhost,127.0.0.1,::1',
       },
     );
     final ValidationResult results = await ProxyValidator(platform: platform).validate();
 
     expect(results.messages, const <ValidationMessage>[
       ValidationMessage('HTTP_PROXY is set'),
-      ValidationMessage('NO_PROXY is localhost,127.0.0.1'),
-      ValidationMessage('NO_PROXY contains 127.0.0.1'),
+      ValidationMessage('NO_PROXY is localhost,127.0.0.1,::1'),
       ValidationMessage('NO_PROXY contains localhost'),
+      ValidationMessage('NO_PROXY contains 127.0.0.1'),
+      ValidationMessage('NO_PROXY contains ::1'),
     ]);
   });
 
@@ -71,31 +101,157 @@ void main() {
     final Platform platform = FakePlatform(
       environment: <String, String>{
         'HTTP_PROXY': 'fakeproxy.local',
-        'NO_PROXY': '127.0.0.1',
+        'NO_PROXY': '127.0.0.1,::1',
       },
     );
     final ValidationResult results = await ProxyValidator(platform: platform).validate();
 
     expect(results.messages, const <ValidationMessage>[
       ValidationMessage('HTTP_PROXY is set'),
-      ValidationMessage('NO_PROXY is 127.0.0.1'),
-      ValidationMessage('NO_PROXY contains 127.0.0.1'),
+      ValidationMessage('NO_PROXY is 127.0.0.1,::1'),
       ValidationMessage.hint('NO_PROXY does not contain localhost'),
+      ValidationMessage('NO_PROXY contains 127.0.0.1'),
+      ValidationMessage('NO_PROXY contains ::1'),
     ]);
   });
 
   testWithoutContext('ProxyValidator reports issues when NO_PROXY is missing 127.0.0.1', () async {
     final Platform platform =  FakePlatform(environment: <String, String>{
       'HTTP_PROXY': 'fakeproxy.local',
-      'NO_PROXY': 'localhost',
+      'NO_PROXY': 'localhost,::1',
     });
     final ValidationResult results = await ProxyValidator(platform: platform).validate();
 
     expect(results.messages, const <ValidationMessage>[
       ValidationMessage('HTTP_PROXY is set'),
-      ValidationMessage('NO_PROXY is localhost'),
+      ValidationMessage('NO_PROXY is localhost,::1'),
+      ValidationMessage('NO_PROXY contains localhost'),
+      ValidationMessage.hint('NO_PROXY does not contain 127.0.0.1'),
+      ValidationMessage('NO_PROXY contains ::1'),
+    ]);
+  });
+
+  testWithoutContext('ProxyValidator reports issues when NO_PROXY is missing ::1', () async {
+    final Platform platform =  FakePlatform(environment: <String, String>{
+      'HTTP_PROXY': 'fakeproxy.local',
+      'NO_PROXY': 'localhost,127.0.0.1',
+    });
+    final ValidationResult results = await ProxyValidator(platform: platform).validate();
+
+    expect(results.messages, const <ValidationMessage>[
+      ValidationMessage('HTTP_PROXY is set'),
+      ValidationMessage('NO_PROXY is localhost,127.0.0.1'),
+      ValidationMessage('NO_PROXY contains localhost'),
+      ValidationMessage('NO_PROXY contains 127.0.0.1'),
+      ValidationMessage.hint('NO_PROXY does not contain ::1'),
+    ]);
+  });
+
+  testWithoutContext('ProxyValidator reports issues when NO_PROXY is missing localhost, 127.0.0.1', () async {
+    final Platform platform = FakePlatform(
+      environment: <String, String>{
+        'HTTP_PROXY': 'fakeproxy.local',
+        'NO_PROXY': '::1',
+      },
+    );
+    final ValidationResult results = await ProxyValidator(platform: platform).validate();
+
+    expect(results.messages, const <ValidationMessage>[
+      ValidationMessage('HTTP_PROXY is set'),
+      ValidationMessage('NO_PROXY is ::1'),
+      ValidationMessage.hint('NO_PROXY does not contain localhost'),
       ValidationMessage.hint('NO_PROXY does not contain 127.0.0.1'),
+      ValidationMessage('NO_PROXY contains ::1'),
+    ]);
+  });
+
+  testWithoutContext('ProxyValidator reports issues when NO_PROXY is missing localhost, ::1', () async {
+    final Platform platform = FakePlatform(
+      environment: <String, String>{
+        'HTTP_PROXY': 'fakeproxy.local',
+        'NO_PROXY': '127.0.0.1',
+      },
+    );
+    final ValidationResult results = await ProxyValidator(platform: platform).validate();
+
+    expect(results.messages, const <ValidationMessage>[
+      ValidationMessage('HTTP_PROXY is set'),
+      ValidationMessage('NO_PROXY is 127.0.0.1'),
+      ValidationMessage.hint('NO_PROXY does not contain localhost'),
+      ValidationMessage('NO_PROXY contains 127.0.0.1'),
+      ValidationMessage.hint('NO_PROXY does not contain ::1'),
+    ]);
+  });
+
+  testWithoutContext('ProxyValidator reports issues when NO_PROXY is missing 127.0.0.1, ::1', () async {
+    final Platform platform = FakePlatform(
+      environment: <String, String>{
+        'HTTP_PROXY': 'fakeproxy.local',
+        'NO_PROXY': 'localhost',
+      },
+    );
+    final ValidationResult results = await ProxyValidator(platform: platform).validate();
+
+    expect(results.messages, const <ValidationMessage>[
+      ValidationMessage('HTTP_PROXY is set'),
+      ValidationMessage('NO_PROXY is localhost'),
       ValidationMessage('NO_PROXY contains localhost'),
+      ValidationMessage.hint('NO_PROXY does not contain 127.0.0.1'),
+      ValidationMessage.hint('NO_PROXY does not contain ::1'),
     ]);
   });
 }
+
+class FakeNetworkInterface extends NetworkInterface {
+  FakeNetworkInterface(List<FakeInternetAddress> addresses):
+        super(FakeNetworkInterfaceDelegate(addresses));
+
+  @override
+  String get name => 'FakeNetworkInterface$index';
+}
+
+class FakeNetworkInterfaceDelegate implements io.NetworkInterface {
+  FakeNetworkInterfaceDelegate(this._fakeAddresses);
+
+  final List<FakeInternetAddress> _fakeAddresses;
+
+  @override
+  List<io.InternetAddress> get addresses => _fakeAddresses;
+
+  @override
+  int get index => addresses.length;
+
+  @override
+  String get name => 'FakeNetworkInterfaceDelegate$index';
+}
+
+class FakeInternetAddress implements io.InternetAddress {
+  const FakeInternetAddress(this._fakeAddress);
+
+  final String _fakeAddress;
+
+  @override
+  String get address => _fakeAddress;
+
+  @override
+  String get host => throw UnimplementedError();
+
+  @override
+  bool get isLinkLocal => throw UnimplementedError();
+
+  @override
+  bool get isLoopback => true;
+
+  @override
+  bool get isMulticast => throw UnimplementedError();
+
+  @override
+  Uint8List get rawAddress => throw UnimplementedError();
+
+  @override
+  Future<io.InternetAddress> reverse() =>
+    throw UnimplementedError();
+
+  @override
+  io.InternetAddressType get type => throw UnimplementedError();
+}