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

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_BROWSER_EXTENSIONS_API_MDNS_MDNS_API_H_
   6 #define CHROME_BROWSER_EXTENSIONS_API_MDNS_MDNS_API_H_
   7
   8 #include <map>
   9 #include <set>
  10 #include <string>
  11
  12 #include "base/gtest_prod_util.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/threading/thread_checker.h"
  15 #include "chrome/browser/extensions/api/mdns/dns_sd_registry.h"
  16 #include "chrome/common/extensions/api/mdns.h"
  17 #include "extensions/browser/api/async_api_function.h"
  18 #include "extensions/browser/browser_context_keyed_api_factory.h"
  19 #include "extensions/browser/event_router.h"
  20 #include "extensions/browser/extension_function.h"
  21
  22 namespace content {
  23 class BrowserContext;
  24 }
  25
  26 namespace extensions {
  27
  28 class DnsSdRegistry;
  29
  30 // MDnsAPI is instantiated with the profile and will listen for extensions that
  31 // register listeners for the chrome.mdns extension API. It will use a registry
  32 // class to start the mDNS listener process (if necessary) and observe new
  33 // service events to dispatch them to registered extensions.
  34 class MDnsAPI : public BrowserContextKeyedAPI,
  35                 public EventRouter::Observer,
  36                 public DnsSdRegistry::DnsSdObserver {
  37  public:
  38   explicit MDnsAPI(content::BrowserContext* context);
  39   ~MDnsAPI() override;
  40
  41   static MDnsAPI* Get(content::BrowserContext* context);
  42
  43   // BrowserContextKeyedAPI implementation.
  44   static BrowserContextKeyedAPIFactory<MDnsAPI>* GetFactoryInstance();
  45
  46   // Used to mock out the DnsSdRegistry for testing.
  47   void SetDnsSdRegistryForTesting(scoped_ptr<DnsSdRegistry> registry);
  48
  49   // Immediately issues a multicast DNS query for all service types.
  50   // NOTE: Discovery queries are sent to all event handlers associated with
  51   // |this| service's BrowserContext.
  52   void ForceDiscovery();
  53
  54  protected:
  55   // Retrieve an instance of the registry. Lazily created when needed.
  56   virtual DnsSdRegistry* dns_sd_registry();
  57
  58   // Gets the list of mDNS event listeners.
  59   virtual const extensions::EventListenerMap::ListenerList& GetEventListeners();
  60
  61  private:
  62   FRIEND_TEST_ALL_PREFIXES(MDnsAPIDiscoveryTest,
  63                            ServiceListenersAddedAndRemoved);
  64
  65   typedef std::map<std::string, int> ServiceTypeCounts;
  66   friend class BrowserContextKeyedAPIFactory<MDnsAPI>;
  67
  68   // EventRouter::Observer:
  69   void OnListenerAdded(const EventListenerInfo& details) override;
  70   void OnListenerRemoved(const EventListenerInfo& details) override;
  71
  72   // DnsSdRegistry::Observer
  73   void OnDnsSdEvent(const std::string& service_type,
  74                     const DnsSdRegistry::DnsSdServiceList& services) override;
  75
  76   // BrowserContextKeyedAPI implementation.
  77   static const char* service_name() {
  78     return "MDnsAPI";
  79   }
  80
  81   static const bool kServiceIsCreatedWithBrowserContext = true;
  82   static const bool kServiceIsNULLWhileTesting = true;
  83
  84   // Update the current list of service types and update the registry.
  85   void UpdateMDnsListeners();
  86
  87   // Write a message to the consoles of extensions listening to a given service
  88   // type.
  89   void WriteToConsole(const std::string& service_type,
  90                       content::ConsoleMessageLevel level,
  91                       const std::string& message);
  92
  93   // Returns true if an extension or platform app |extension_id| is allowed to
  94   // listen to mDNS events for |service_type|.
  95   virtual bool IsMDnsAllowed(const std::string& extension_id,
  96                              const std::string& service_type) const;
  97
  98   // Finds all all the valid listeners of the mdns.onServiceList event and
  99   // filters them by service type if |service_type_filter| is non-empty.
 100   // The list of extensions with active listeners is written to |extension_ids|,
 101   // if non-null.
 102   // The counts for each service type are output to |service_type_counts|, if
 103   // non-null.
 104   void GetValidOnServiceListListeners(const std::string& service_type_filter,
 105                                       std::set<std::string>* extension_ids,
 106                                       ServiceTypeCounts* service_type_counts);
 107
 108   // Ensure methods are only called on UI thread.
 109   base::ThreadChecker thread_checker_;
 110   content::BrowserContext* const browser_context_;
 111   // Lazily created on first access and destroyed with this API class.
 112   scoped_ptr<DnsSdRegistry> dns_sd_registry_;
 113   // Count of active listeners per service type, saved from the previous
 114   // invocation of UpdateMDnsListeners().
 115   ServiceTypeCounts prev_service_counts_;
 116
 117   DISALLOW_COPY_AND_ASSIGN(MDnsAPI);
 118 };
 119
 120 class MdnsForceDiscoveryFunction : public UIThreadExtensionFunction {
 121  public:
 122   MdnsForceDiscoveryFunction();
 123
 124  protected:
 125   ~MdnsForceDiscoveryFunction() override;
 126
 127  private:
 128   // UIThreadExtensionFunction override.
 129   ResponseAction Run() override;
 130
 131   DECLARE_EXTENSION_FUNCTION("mdns.forceDiscovery", MDNS_FORCEDISCOVERY);
 132   DISALLOW_COPY_AND_ASSIGN(MdnsForceDiscoveryFunction);
 133 };
 134
 135 }  // namespace extensions
 136
 137 #endif  // CHROME_BROWSER_EXTENSIONS_API_MDNS_MDNS_API_H_