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