net/dns/mdns_client_impl.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 NET_DNS_MDNS_CLIENT_IMPL_H_
   6 #define NET_DNS_MDNS_CLIENT_IMPL_H_
   7
   8 #include <map>
   9 #include <string>
  10 #include <utility>
  11 #include <vector>
  12
  13 #include "base/cancelable_callback.h"
  14 #include "base/memory/scoped_vector.h"
  15 #include "base/observer_list.h"
  16 #include "net/base/io_buffer.h"
  17 #include "net/base/ip_endpoint.h"
  18 #include "net/dns/mdns_cache.h"
  19 #include "net/dns/mdns_client.h"
  20 #include "net/udp/datagram_server_socket.h"
  21 #include "net/udp/udp_server_socket.h"
  22 #include "net/udp/udp_socket.h"
  23
  24 namespace net {
  25
  26 class MDnsSocketFactoryImpl : public MDnsSocketFactory {
  27  public:
  28   MDnsSocketFactoryImpl() {};
  29   ~MDnsSocketFactoryImpl() override{};
  30
  31   void CreateSockets(ScopedVector<DatagramServerSocket>* sockets) override;
  32
  33  private:
  34   DISALLOW_COPY_AND_ASSIGN(MDnsSocketFactoryImpl);
  35 };
  36
  37 // A connection to the network for multicast DNS clients. It reads data into
  38 // DnsResponse objects and alerts the delegate that a packet has been received.
  39 class NET_EXPORT_PRIVATE MDnsConnection {
  40  public:
  41   class Delegate {
  42    public:
  43     // Handle an mDNS packet buffered in |response| with a size of |bytes_read|.
  44     virtual void HandlePacket(DnsResponse* response, int bytes_read) = 0;
  45     virtual void OnConnectionError(int error) = 0;
  46     virtual ~Delegate() {}
  47   };
  48
  49   explicit MDnsConnection(MDnsConnection::Delegate* delegate);
  50   virtual ~MDnsConnection();
  51
  52   // Both methods return true if at least one of the socket handlers succeeded.
  53   bool Init(MDnsSocketFactory* socket_factory);
  54   void Send(const scoped_refptr<IOBuffer>& buffer, unsigned size);
  55
  56  private:
  57   class SocketHandler {
  58    public:
  59     SocketHandler(scoped_ptr<DatagramServerSocket> socket,
  60                   MDnsConnection* connection);
  61     ~SocketHandler();
  62
  63     int Start();
  64     void Send(const scoped_refptr<IOBuffer>& buffer, unsigned size);
  65
  66    private:
  67     int DoLoop(int rv);
  68     void OnDatagramReceived(int rv);
  69
  70     // Callback for when sending a query has finished.
  71     void SendDone(int rv);
  72
  73     scoped_ptr<DatagramServerSocket> socket_;
  74     MDnsConnection* connection_;
  75     IPEndPoint recv_addr_;
  76     DnsResponse response_;
  77     IPEndPoint multicast_addr_;
  78     bool send_in_progress_;
  79     std::queue<std::pair<scoped_refptr<IOBuffer>, unsigned> > send_queue_;
  80
  81     DISALLOW_COPY_AND_ASSIGN(SocketHandler);
  82   };
  83
  84   // Callback for handling a datagram being received on either ipv4 or ipv6.
  85   void OnDatagramReceived(DnsResponse* response,
  86                           const IPEndPoint& recv_addr,
  87                           int bytes_read);
  88
  89   void PostOnError(SocketHandler* loop, int rv);
  90   void OnError(int rv);
  91
  92   // Only socket handlers which successfully bound and started are kept.
  93   ScopedVector<SocketHandler> socket_handlers_;
  94
  95   Delegate* delegate_;
  96
  97   base::WeakPtrFactory<MDnsConnection> weak_ptr_factory_;
  98
  99   DISALLOW_COPY_AND_ASSIGN(MDnsConnection);
 100 };
 101
 102 class MDnsListenerImpl;
 103
 104 class NET_EXPORT_PRIVATE MDnsClientImpl : public MDnsClient {
 105  public:
 106   // The core object exists while the MDnsClient is listening, and is deleted
 107   // whenever the number of listeners reaches zero. The deletion happens
 108   // asychronously, so destroying the last listener does not immediately
 109   // invalidate the core.
 110   class Core : public base::SupportsWeakPtr<Core>, MDnsConnection::Delegate {
 111    public:
 112     Core();
 113     ~Core() override;
 114
 115     // Initialize the core. Returns true on success.
 116     bool Init(MDnsSocketFactory* socket_factory);
 117
 118     // Send a query with a specific rrtype and name. Returns true on success.
 119     bool SendQuery(uint16 rrtype, std::string name);
 120
 121     // Add/remove a listener to the list of listeners.
 122     void AddListener(MDnsListenerImpl* listener);
 123     void RemoveListener(MDnsListenerImpl* listener);
 124
 125     // Query the cache for records of a specific type and name.
 126     void QueryCache(uint16 rrtype, const std::string& name,
 127                     std::vector<const RecordParsed*>* records) const;
 128
 129     // Parse the response and alert relevant listeners.
 130     void HandlePacket(DnsResponse* response, int bytes_read) override;
 131
 132     void OnConnectionError(int error) override;
 133
 134    private:
 135     typedef std::pair<std::string, uint16> ListenerKey;
 136     typedef std::map<ListenerKey, ObserverList<MDnsListenerImpl>* >
 137     ListenerMap;
 138
 139     // Alert listeners of an update to the cache.
 140     void AlertListeners(MDnsCache::UpdateType update_type,
 141                         const ListenerKey& key, const RecordParsed* record);
 142
 143     // Schedule a cache cleanup to a specific time, cancelling other cleanups.
 144     void ScheduleCleanup(base::Time cleanup);
 145
 146     // Clean up the cache and schedule a new cleanup.
 147     void DoCleanup();
 148
 149     // Callback for when a record is removed from the cache.
 150     void OnRecordRemoved(const RecordParsed* record);
 151
 152     void NotifyNsecRecord(const RecordParsed* record);
 153
 154     // Delete and erase the observer list for |key|. Only deletes the observer
 155     // list if is empty.
 156     void CleanupObserverList(const ListenerKey& key);
 157
 158     ListenerMap listeners_;
 159
 160     MDnsCache cache_;
 161
 162     base::CancelableClosure cleanup_callback_;
 163     base::Time scheduled_cleanup_;
 164
 165     scoped_ptr<MDnsConnection> connection_;
 166
 167     DISALLOW_COPY_AND_ASSIGN(Core);
 168   };
 169
 170   MDnsClientImpl();
 171   ~MDnsClientImpl() override;
 172
 173   // MDnsClient implementation:
 174   scoped_ptr<MDnsListener> CreateListener(
 175       uint16 rrtype,
 176       const std::string& name,
 177       MDnsListener::Delegate* delegate) override;
 178
 179   scoped_ptr<MDnsTransaction> CreateTransaction(
 180       uint16 rrtype,
 181       const std::string& name,
 182       int flags,
 183       const MDnsTransaction::ResultCallback& callback) override;
 184
 185   bool StartListening(MDnsSocketFactory* socket_factory) override;
 186   void StopListening() override;
 187   bool IsListening() const override;
 188
 189   Core* core() { return core_.get(); }
 190
 191  private:
 192   scoped_ptr<Core> core_;
 193
 194   DISALLOW_COPY_AND_ASSIGN(MDnsClientImpl);
 195 };
 196
 197 class MDnsListenerImpl : public MDnsListener,
 198                          public base::SupportsWeakPtr<MDnsListenerImpl> {
 199  public:
 200   MDnsListenerImpl(uint16 rrtype,
 201                    const std::string& name,
 202                    MDnsListener::Delegate* delegate,
 203                    MDnsClientImpl* client);
 204
 205   ~MDnsListenerImpl() override;
 206
 207   // MDnsListener implementation:
 208   bool Start() override;
 209
 210   // Actively refresh any received records.
 211   void SetActiveRefresh(bool active_refresh) override;
 212
 213   const std::string& GetName() const override;
 214
 215   uint16 GetType() const override;
 216
 217   MDnsListener::Delegate* delegate() { return delegate_; }
 218
 219   // Alert the delegate of a record update.
 220   void HandleRecordUpdate(MDnsCache::UpdateType update_type,
 221                           const RecordParsed* record_parsed);
 222
 223   // Alert the delegate of the existence of an Nsec record.
 224   void AlertNsecRecord();
 225
 226  private:
 227   void ScheduleNextRefresh();
 228   void DoRefresh();
 229
 230   uint16 rrtype_;
 231   std::string name_;
 232   MDnsClientImpl* client_;
 233   MDnsListener::Delegate* delegate_;
 234
 235   base::Time last_update_;
 236   uint32 ttl_;
 237   bool started_;
 238   bool active_refresh_;
 239
 240   base::CancelableClosure next_refresh_;
 241   DISALLOW_COPY_AND_ASSIGN(MDnsListenerImpl);
 242 };
 243
 244 class MDnsTransactionImpl : public base::SupportsWeakPtr<MDnsTransactionImpl>,
 245                             public MDnsTransaction,
 246                             public MDnsListener::Delegate {
 247  public:
 248   MDnsTransactionImpl(uint16 rrtype,
 249                       const std::string& name,
 250                       int flags,
 251                       const MDnsTransaction::ResultCallback& callback,
 252                       MDnsClientImpl* client);
 253   ~MDnsTransactionImpl() override;
 254
 255   // MDnsTransaction implementation:
 256   bool Start() override;
 257
 258   const std::string& GetName() const override;
 259   uint16 GetType() const override;
 260
 261   // MDnsListener::Delegate implementation:
 262   void OnRecordUpdate(MDnsListener::UpdateType update,
 263                       const RecordParsed* record) override;
 264   void OnNsecRecord(const std::string& name, unsigned type) override;
 265
 266   void OnCachePurged() override;
 267
 268  private:
 269   bool is_active() { return !callback_.is_null(); }
 270
 271   void Reset();
 272
 273   // Trigger the callback and reset all related variables.
 274   void TriggerCallback(MDnsTransaction::Result result,
 275                        const RecordParsed* record);
 276
 277   // Internal callback for when a cache record is found.
 278   void CacheRecordFound(const RecordParsed* record);
 279
 280   // Signal the transactionis over and release all related resources.
 281   void SignalTransactionOver();
 282
 283   // Reads records from the cache and calls the callback for every
 284   // record read.
 285   void ServeRecordsFromCache();
 286
 287   // Send a query to the network and set up a timeout to time out the
 288   // transaction. Returns false if it fails to start listening on the network
 289   // or if it fails to send a query.
 290   bool QueryAndListen();
 291
 292   uint16 rrtype_;
 293   std::string name_;
 294   MDnsTransaction::ResultCallback callback_;
 295
 296   scoped_ptr<MDnsListener> listener_;
 297   base::CancelableCallback<void()> timeout_;
 298
 299   MDnsClientImpl* client_;
 300
 301   bool started_;
 302   int flags_;
 303
 304   DISALLOW_COPY_AND_ASSIGN(MDnsTransactionImpl);
 305 };
 306
 307 }  // namespace net
 308 #endif  // NET_DNS_MDNS_CLIENT_IMPL_H_