Add flag to not publish the observatory port over mDNS (flutter#21883)

common/settings.cc

@@ -46,6 +46,8 @@ std::string Settings::ToString() const {
   stream << "enable_dart_profiling: " << enable_dart_profiling << std::endl;
   stream << "disable_dart_asserts: " << disable_dart_asserts << std::endl;
   stream << "enable_observatory: " << enable_observatory << std::endl;
+  stream << "enable_observatory_publication: " << enable_observatory_publication
+         << std::endl;
   stream << "observatory_host: " << observatory_host << std::endl;
   stream << "observatory_port: " << observatory_port << std::endl;
   stream << "use_test_fonts: " << use_test_fonts << std::endl;

common/settings.h

@@ -126,6 +126,11 @@ struct Settings {
   // Whether the Dart VM service should be enabled.
   bool enable_observatory = false;
 
+  // Whether to publish the observatory URL over mDNS.
+  // On iOS 14 this prompts a local network permission dialog,
+  // which cannot be accepted or dismissed in a CI environment.
+  bool enable_observatory_publication = true;
+
   // The IP address to which the Dart VM service is bound.
   std::string observatory_host;
 

shell/common/switches.cc

@@ -221,6 +221,10 @@ Settings SettingsFromCommandLine(const fml::CommandLine& command_line) {
   settings.enable_observatory =
       !command_line.HasOption(FlagForSwitch(Switch::DisableObservatory));
 
+  // Enable mDNS Observatory Publication
+  settings.enable_observatory_publication = !command_line.HasOption(
+      FlagForSwitch(Switch::DisableObservatoryPublication));
+
   // Set Observatory Host
   if (command_line.HasOption(FlagForSwitch(Switch::DeviceObservatoryHost))) {
     command_line.GetOptionValue(FlagForSwitch(Switch::DeviceObservatoryHost),

shell/common/switches.h

@@ -79,6 +79,9 @@ DEF_SWITCH(DisableObservatory,
            "disable-observatory",
            "Disable the Dart Observatory. The observatory is never available "
            "in release mode.")
+DEF_SWITCH(DisableObservatoryPublication,
+           "disable-observatory-publication",
+           "Disable mDNS Dart Observatory publication.")
 DEF_SWITCH(IPv6,
            "ipv6",
            "Bind to the IPv6 localhost address for the Dart Observatory. "

shell/platform/darwin/ios/framework/Source/FlutterEngine.mm

@@ -547,7 +547,8 @@ - (BOOL)createShell:(NSString*)entrypoint
     if (!_platformViewsController) {
       _platformViewsController.reset(new flutter::FlutterPlatformViewsController());
     }
-    _publisher.reset([[FlutterObservatoryPublisher alloc] init]);
+    _publisher.reset([[FlutterObservatoryPublisher alloc]
+        initWithEnableObservatoryPublication:settings.enable_observatory_publication]);
     [self maybeSetupPlatformViewChannels];
     _shell->GetIsGpuDisabledSyncSwitch()->SetSwitch(_isGpuDisabled ? true : false);
     if (profilerEnabled) {

shell/platform/darwin/ios/framework/Source/FlutterObservatoryPublisher.h

@@ -9,6 +9,11 @@
 
 @interface FlutterObservatoryPublisher : NSObject
 
+- (instancetype)initWithEnableObservatoryPublication:(BOOL)enableObservatoryPublication
+    NS_DESIGNATED_INITIALIZER;
+- (instancetype)init NS_UNAVAILABLE;
++ (instancetype)new NS_UNAVAILABLE;
+
 @property(nonatomic, readonly) NSURL* url;
 
 @end

shell/platform/darwin/ios/framework/Source/FlutterObservatoryPublisher.mm

@@ -9,6 +9,9 @@
 #if FLUTTER_RELEASE
 
 @implementation FlutterObservatoryPublisher
+- (instancetype)initWithEnableObservatoryPublication:(BOOL)enableObservatoryPublication {
+  return [super init];
+}
 @end
 
 #else  // FLUTTER_RELEASE
@@ -37,26 +40,23 @@ @implementation FlutterObservatoryPublisher
 #include <net/if.h>
 
 #include "flutter/fml/logging.h"
-#include "flutter/fml/make_copyable.h"
 #include "flutter/fml/memory/weak_ptr.h"
 #include "flutter/fml/message_loop.h"
 #include "flutter/fml/platform/darwin/scoped_nsobject.h"
-#include "flutter/fml/task_runner.h"
 #include "flutter/runtime/dart_service_isolate.h"
 
 @protocol FlutterObservatoryPublisherDelegate
-- (instancetype)initWithOwner:(FlutterObservatoryPublisher*)owner;
-- (void)publishServiceProtocolPort:(NSString*)uri;
+- (void)publishServiceProtocolPort:(NSURL*)uri;
 - (void)stopService;
-
-@property(readonly) fml::scoped_nsobject<NSURL> url;
 @end
 
 @interface FlutterObservatoryPublisher ()
-- (NSData*)createTxtData:(NSURL*)url;
++ (NSData*)createTxtData:(NSURL*)url;
 
-@property(readonly) NSString* serviceName;
+@property(readonly, class) NSString* serviceName;
 @property(readonly) fml::scoped_nsobject<NSObject<FlutterObservatoryPublisherDelegate>> delegate;
+@property(nonatomic, readwrite) NSURL* url;
+@property(readonly) BOOL enableObservatoryPublication;
 
 @end
 
@@ -68,31 +68,17 @@ @interface ObservatoryDNSServiceDelegate : NSObject <FlutterObservatoryPublisher
 @end
 
 @implementation ObservatoryDNSServiceDelegate {
-  fml::scoped_nsobject<FlutterObservatoryPublisher> _owner;
   DNSServiceRef _dnsServiceRef;
 }
 
-@synthesize url;
-
-- (instancetype)initWithOwner:(FlutterObservatoryPublisher*)owner {
-  self = [super init];
-  NSAssert(self, @"Super must not return null on init.");
-  _owner.reset([owner retain]);
-  return self;
-}
-
 - (void)stopService {
   if (_dnsServiceRef) {
     DNSServiceRefDeallocate(_dnsServiceRef);
     _dnsServiceRef = NULL;
   }
 }
 
-- (void)publishServiceProtocolPort:(NSString*)uri {
-  // uri comes in as something like 'http://127.0.0.1:XXXXX/' where XXXXX is the port
-  // number.
-  url.reset([[NSURL alloc] initWithString:uri]);
-
+- (void)publishServiceProtocolPort:(NSURL*)url {
   DNSServiceFlags flags = kDNSServiceFlagsDefault;
 #if TARGET_IPHONE_SIMULATOR
   // Simulator needs to use local loopback explicitly to work.
@@ -105,11 +91,11 @@ - (void)publishServiceProtocolPort:(NSString*)uri {
   const char* domain = "local.";  // default domain
   uint16_t port = [[url port] unsignedShortValue];
 
-  NSData* txtData = [_owner createTxtData:url.get()];
-  int err =
-      DNSServiceRegister(&_dnsServiceRef, flags, interfaceIndex,
-                         [_owner.get().serviceName UTF8String], registrationType, domain, NULL,
-                         htons(port), txtData.length, txtData.bytes, registrationCallback, NULL);
+  NSData* txtData = [FlutterObservatoryPublisher createTxtData:url];
+  int err = DNSServiceRegister(&_dnsServiceRef, flags, interfaceIndex,
+                               FlutterObservatoryPublisher.serviceName.UTF8String, registrationType,
+                               domain, NULL, htons(port), txtData.length, txtData.bytes,
+                               registrationCallback, NULL);
 
   if (err != 0) {
     FML_LOG(ERROR) << "Failed to register observatory port with mDNS with error " << err << ".";
@@ -122,8 +108,8 @@ - (void)publishServiceProtocolPort:(NSString*)uri {
                      << "to the 'NSBonjourServices' key in your Info.plist for the Debug/"
                      << "Profile configurations. "
                      << "For more information, see "
-                     // Update link to a specific header as needed.
-                     << "https://flutter.dev/docs/development/add-to-app/ios/project-setup";
+                     << "https://flutter.dev/docs/development/add-to-app/ios/"
+                        "project-setup#local-network-privacy-permissions";
     }
   } else {
     DNSServiceSetDispatchQueue(_dnsServiceRef, dispatch_get_main_queue());
@@ -162,34 +148,21 @@ static void DNSSD_API registrationCallback(DNSServiceRef sdRef,
 @end
 
 @implementation ObservatoryNSNetServiceDelegate {
-  fml::scoped_nsobject<FlutterObservatoryPublisher> _owner;
   fml::scoped_nsobject<NSNetService> _netService;
 }
 
-@synthesize url;
-
-- (instancetype)initWithOwner:(FlutterObservatoryPublisher*)owner {
-  self = [super init];
-  NSAssert(self, @"Super must not return null on init.");
-  _owner.reset([owner retain]);
-  return self;
-}
-
 - (void)stopService {
   [_netService.get() stop];
   [_netService.get() setDelegate:nil];
 }
 
-- (void)publishServiceProtocolPort:(NSString*)uri {
-  // uri comes in as something like 'http://127.0.0.1:XXXXX/' where XXXXX is the port
-  // number.
-  url.reset([[NSURL alloc] initWithString:uri]);
-
-  NSNetService* netServiceTmp = [[NSNetService alloc] initWithDomain:@"local."
-                                                                type:@"_dartobservatory._tcp."
-                                                                name:_owner.get().serviceName
-                                                                port:[[url port] intValue]];
-  [netServiceTmp setTXTRecordData:[_owner createTxtData:url.get()]];
+- (void)publishServiceProtocolPort:(NSURL*)url {
+  NSNetService* netServiceTmp =
+      [[NSNetService alloc] initWithDomain:@"local."
+                                      type:@"_dartobservatory._tcp."
+                                      name:FlutterObservatoryPublisher.serviceName
+                                      port:[[url port] intValue]];
+  [netServiceTmp setTXTRecordData:[FlutterObservatoryPublisher createTxtData:url]];
   _netService.reset(netServiceTmp);
   [_netService.get() setDelegate:self];
   [_netService.get() publish];
@@ -211,19 +184,16 @@ @implementation FlutterObservatoryPublisher {
   std::unique_ptr<fml::WeakPtrFactory<FlutterObservatoryPublisher>> _weakFactory;
 }
 
-- (NSURL*)url {
-  return [_delegate.get().url autorelease];
-}
-
-- (instancetype)init {
+- (instancetype)initWithEnableObservatoryPublication:(BOOL)enableObservatoryPublication {
   self = [super init];
   NSAssert(self, @"Super must not return null on init.");
 
   if (@available(iOS 9.3, *)) {
-    _delegate.reset([[ObservatoryDNSServiceDelegate alloc] initWithOwner:self]);
+    _delegate.reset([[ObservatoryDNSServiceDelegate alloc] init]);
   } else {
-    _delegate.reset([[ObservatoryNSNetServiceDelegate alloc] initWithOwner:self]);
+    _delegate.reset([[ObservatoryNSNetServiceDelegate alloc] init]);
   }
+  _enableObservatoryPublication = enableObservatoryPublication;
   _weakFactory = std::make_unique<fml::WeakPtrFactory<FlutterObservatoryPublisher>>(self);
 
   fml::MessageLoop::EnsureInitializedForCurrentThread();
@@ -233,9 +203,15 @@ - (instancetype)init {
        runner = fml::MessageLoop::GetCurrent().GetTaskRunner()](const std::string& uri) {
         if (!uri.empty()) {
           runner->PostTask([weak, uri]() {
+            // uri comes in as something like 'http://127.0.0.1:XXXXX/' where XXXXX is the port
+            // number.
             if (weak) {
-              [[weak.get() delegate]
-                  publishServiceProtocolPort:[NSString stringWithUTF8String:uri.c_str()]];
+              NSURL* url =
+                  [[NSURL alloc] initWithString:[NSString stringWithUTF8String:uri.c_str()]];
+              weak.get().url = url;
+              if (weak.get().enableObservatoryPublication) {
+                [[weak.get() delegate] publishServiceProtocolPort:url];
+              }
             }
           });
         }
@@ -244,11 +220,11 @@ - (instancetype)init {
   return self;
 }
 
-- (NSString*)serviceName {
++ (NSString*)serviceName {
   return NSBundle.mainBundle.bundleIdentifier;
 }
 
-- (NSData*)createTxtData:(NSURL*)url {
++ (NSData*)createTxtData:(NSURL*)url {
   // Check to see if there's an authentication code. If there is, we'll provide
   // it as a txt record so flutter tools can establish a connection.
   NSString* path = [[url path] substringFromIndex:MIN(1, [[url path] length])];
@@ -261,6 +237,7 @@ - (NSData*)createTxtData:(NSURL*)url {
 
 - (void)dealloc {
   [_delegate stopService];
+  [_url release];
 
   flutter::DartServiceIsolate::RemoveServerStatusCallback(std::move(_callbackHandle));
   [super dealloc];