Initial chrome.mdns API.

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

+// Copyright (c) 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/browser/extensions/extension_system.h"
+#include "chrome/common/extensions/api/mdns.h"
+
+namespace extensions {
+
+namespace mdns = api::mdns;
+
+namespace {
+
+// Whitelisted mDNS service types.
+const char kCastServiceType[] = "_googlecast._tcp.local";
+const char kTestServiceType[] = "_testing._tcp.local";
+
+bool IsServiceTypeWhitelisted(const std::string& service_type) {
+  return service_type == kCastServiceType ||
+         service_type == kTestServiceType;
+}
+
+}  // namespace
+
+MDnsAPI::MDnsAPI(Profile* profile) : profile_(profile) {
+  DCHECK(profile_);
+  ExtensionSystem::Get(profile)->event_router()->RegisterObserver(
+      this, mdns::OnServiceList::kEventName);
+}
+
+MDnsAPI::~MDnsAPI() {
+  if (dns_sd_registry_.get()) {
+    dns_sd_registry_->RemoveObserver(this);
+  }
+}
+
+// static
+MDnsAPI* MDnsAPI::Get(Profile* profile) {
+  return ProfileKeyedAPIFactory<MDnsAPI>::GetForProfile(profile);
+}
+
+static base::LazyInstance<ProfileKeyedAPIFactory<MDnsAPI> > g_factory =
+    LAZY_INSTANCE_INITIALIZER;
+
+// static
+ProfileKeyedAPIFactory<MDnsAPI>* MDnsAPI::GetFactoryInstance() {
+  return &g_factory.Get();
+}
+
+void MDnsAPI::SetDnsSdRegistryForTesting(
+    scoped_ptr<DnsSdRegistry> dns_sd_registry) {
+  dns_sd_registry_ = dns_sd_registry.Pass();
+}
+
+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.
+  const EventListenerMap::ListenerList& listeners =
+      extensions::ExtensionSystem::Get(profile_)->event_router()->
+          listeners().GetEventListenersByName(details.event_name);
+  for (EventListenerMap::ListenerList::const_iterator it = listeners.begin();
+       it != listeners.end(); ++it) {
+    base::DictionaryValue* filter = ((*it)->filter.get());
+    for (base::DictionaryValue::Iterator iter(*filter);
+       !iter.IsAtEnd(); iter.Advance()) {
+    }
+
+    std::string filter_value;
+    filter->GetStringASCII(kEventFilterServiceTypeKey, &filter_value);
+    if (filter_value.empty())
+      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> >(
+          service_types_, new_service_types);
+  std::set<std::string> removed_service_types =
+      base::STLSetDifference<std::set<std::string> >(
+          new_service_types, 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 (std::set<std::string>::iterator it = removed_service_types.begin();
+       it != removed_service_types.end(); ++it) {
+    if (IsServiceTypeWhitelisted(*it))
+      registry->UnregisterDnsSdListener(*it);
+  }
+
+  service_types_ = new_service_types;
+}
+
+void MDnsAPI::OnDnsSdEvent(const std::string& service_type,
+                           const DnsSdRegistry::DnsSdServiceList& services) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (services.size() == 0)
+    return;
+
+  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);
+    // TODO(justinlin, mfoltz): Copy data from service list.
+    mdns_service->service_name = service_type;
+    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_profile = profile_;
+  event->filter_info.SetServiceType(service_type);
+
+  // TODO(justinlin): To avoid having listeners without filters getting all
+  // events, modify API to have this event require filters.
+  extensions::ExtensionSystem::Get(profile_)->event_router()->
+      BroadcastEvent(event.Pass());
+}
+
+}  // namespace extensions