Enable chrome.mdns for Chrome Apps

chrome/browser/extensions/api/mdns/mdns_api.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/api/mdns/mdns_api.h"
 
 #include <vector>
 
 #include "base/lazy_instance.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/common/extensions/api/mdns.h"
+#include "extensions/browser/extension_registry.h"
 
 namespace extensions {
 
 namespace mdns = api::mdns;
 
 namespace {
 
 // Whitelisted mDNS service types.
 const char kCastServiceType[] = "_googlecast._tcp.local";
 const char kPrivetServiceType[] = "_privet._tcp.local";
 const char kTestServiceType[] = "_testing._tcp.local";
 
 bool IsServiceTypeWhitelisted(const std::string& service_type) {
   return service_type == kCastServiceType ||
          service_type == kPrivetServiceType ||
          service_type == kTestServiceType;
 }
 
 }  // namespace
 
 MDnsAPI::MDnsAPI(content::BrowserContext* context) : browser_context_(context) {
   DCHECK(browser_context_);
-  EventRouter::Get(context)
-      ->RegisterObserver(this, mdns::OnServiceList::kEventName);
+  extensions::EventRouter* event_router = EventRouter::Get(context);
+  DCHECK(event_router);
+  event_router->RegisterObserver(this, mdns::OnServiceList::kEventName);
 }
 
 MDnsAPI::~MDnsAPI() {
   if (dns_sd_registry_.get()) {
     dns_sd_registry_->RemoveObserver(this);
   }
 }
 
 // static
 MDnsAPI* MDnsAPI::Get(content::BrowserContext* context) {
   return BrowserContextKeyedAPIFactory<MDnsAPI>::Get(context);
 }
 
 static base::LazyInstance<BrowserContextKeyedAPIFactory<MDnsAPI> > g_factory =
     LAZY_INSTANCE_INITIALIZER;
 
 // static
 BrowserContextKeyedAPIFactory<MDnsAPI>* MDnsAPI::GetFactoryInstance() {
   return g_factory.Pointer();
 }
 
 void MDnsAPI::SetDnsSdRegistryForTesting(
     scoped_ptr<DnsSdRegistry> dns_sd_registry) {
   dns_sd_registry_ = dns_sd_registry.Pass();
+  if (dns_sd_registry_.get())
+    dns_sd_registry_.get()->AddObserver(this);
 }
 
 DnsSdRegistry* MDnsAPI::dns_sd_registry() {
   DCHECK(thread_checker_.CalledOnValidThread());
   if (!dns_sd_registry_.get()) {
     dns_sd_registry_.reset(new extensions::DnsSdRegistry());
     dns_sd_registry_->AddObserver(this);
   }
   return dns_sd_registry_.get();
 }
 
 void MDnsAPI::OnListenerAdded(const EventListenerInfo& details) {
   DCHECK(thread_checker_.CalledOnValidThread());
   UpdateMDnsListeners(details);
 }
 
 void MDnsAPI::OnListenerRemoved(const EventListenerInfo& details) {
   DCHECK(thread_checker_.CalledOnValidThread());
   UpdateMDnsListeners(details);
 }
 
 void MDnsAPI::UpdateMDnsListeners(const EventListenerInfo& details) {
   std::set<std::string> new_service_types;
 
-  // Check all listeners for service type filers.
+  // Check all listeners for service type filters.
   const EventListenerMap::ListenerList& listeners =
       extensions::EventRouter::Get(browser_context_)
           ->listeners()
           .GetEventListenersByName(details.event_name);
   for (EventListenerMap::ListenerList::const_iterator it = listeners.begin();
        it != listeners.end(); ++it) {
     base::DictionaryValue* filter = ((*it)->filter());
 
     std::string filter_value;
     filter->GetStringASCII(kEventFilterServiceTypeKey, &filter_value);
     if (filter_value.empty())
       continue;
+
+    const Extension* extension = ExtensionRegistry::Get(browser_context_)->
+        enabled_extensions().GetByID((*it)->extension_id());
+    // Don't listen for services associated only with disabled extensions.
+    if (!extension)
+      continue;
+
+    // Platform apps may query for all services; other types of extensions are
+    // restricted to a whitelist.
+    if (!extension->is_platform_app() &&
+        !IsServiceTypeWhitelisted(filter_value))
+      continue;
+
     new_service_types.insert(filter_value);
   }
 
   // Find all the added and removed service types since last update.
   std::set<std::string> added_service_types =
       base::STLSetDifference<std::set<std::string> >(
           new_service_types, service_types_);
   std::set<std::string> removed_service_types =
       base::STLSetDifference<std::set<std::string> >(
           service_types_, new_service_types);
 
   // Update the registry.
   DnsSdRegistry* registry = dns_sd_registry();
-  for (std::set<std::string>::iterator it = added_service_types.begin();
-       it != added_service_types.end(); ++it) {
-    if (IsServiceTypeWhitelisted(*it))
-      registry->RegisterDnsSdListener(*it);
+  for (const auto& srv : added_service_types) {
+    registry->RegisterDnsSdListener(srv);
   }
-  for (std::set<std::string>::iterator it = removed_service_types.begin();
-       it != removed_service_types.end(); ++it) {
-    if (IsServiceTypeWhitelisted(*it))
-      registry->UnregisterDnsSdListener(*it);
+  for (const auto& srv : removed_service_types) {
+    registry->UnregisterDnsSdListener(srv);
   }
-
   service_types_ = new_service_types;
 }
 
 void MDnsAPI::OnDnsSdEvent(const std::string& service_type,
                            const DnsSdRegistry::DnsSdServiceList& services) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   std::vector<linked_ptr<mdns::MDnsService> > args;
   for (DnsSdRegistry::DnsSdServiceList::const_iterator it = services.begin();
        it != services.end(); ++it) {
     linked_ptr<mdns::MDnsService> mdns_service =
         make_linked_ptr(new mdns::MDnsService);
     mdns_service->service_name = (*it).service_name;
     mdns_service->service_host_port = (*it).service_host_port;
     mdns_service->ip_address = (*it).ip_address;
     mdns_service->service_data = (*it).service_data;
     args.push_back(mdns_service);
   }
 
   scoped_ptr<base::ListValue> results = mdns::OnServiceList::Create(args);
   scoped_ptr<Event> event(
       new Event(mdns::OnServiceList::kEventName, results.Pass()));
   event->restrict_to_browser_context = browser_context_;
   event->filter_info.SetServiceType(service_type);
 
-  VLOG(1) << "Broadcasting OnServiceList event: " << event.get();
-
   // TODO(justinlin): To avoid having listeners without filters getting all
   // events, modify API to have this event require filters.
+  // TODO(reddaly): If event isn't on whitelist, ensure it does not get
+  // broadcast to extensions.
   extensions::EventRouter::Get(browser_context_)->BroadcastEvent(event.Pass());
 }
 
 }  // namespace extensions