remoting/protocol/transport.h

   1 // Copyright (c) 2012 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 // This file defines the interface for peer-to-peer transport. There
   6 // are two types of transport: StreamTransport and DatagramTransport.
   7 // They must both be created using TransportFactory instances and they
   8 // provide the same interface, except that one should be used for
   9 // reliable stream connection and the other one for unreliable
  10 // datagram connection. The Transport interface itself doesn't provide
  11 // methods to send/receive data. Instead it creates an instance of
  12 // net::Socket or net::SocketStream which provides access to the data
  13 // channel. After a new transport is Initialize()'ed the Connect()
  14 // method must be called. Connect() starts asynchronous creation and
  15 // initialization of the connection socket that can be used later to
  16 // send and receive data. The socket is passed to the callback
  17 // specified in the Connect() call. The Transport object must exist
  18 // during the whole lifetime of the connection socket. Later deletion
  19 // of the connection socket causes teardown of the corresponding
  20 // Transport object.
  21
  22 #ifndef REMOTING_PROTOCOL_TRANSPORT_H_
  23 #define REMOTING_PROTOCOL_TRANSPORT_H_
  24
  25 #include <string>
  26
  27 #include "base/basictypes.h"
  28 #include "base/callback_forward.h"
  29 #include "base/memory/scoped_ptr.h"
  30 #include "base/threading/non_thread_safe.h"
  31 #include "net/base/ip_endpoint.h"
  32
  33 namespace cricket {
  34 class Candidate;
  35 }  // namespace cricket
  36
  37 namespace net {
  38 class Socket;
  39 class StreamSocket;
  40 }  // namespace net
  41
  42 namespace remoting {
  43 namespace protocol {
  44
  45 class ChannelAuthenticator;
  46
  47 struct TransportRoute {
  48   enum RouteType {
  49     DIRECT,
  50     STUN,
  51     RELAY,
  52   };
  53
  54   // Helper method to get string representation of the type.
  55   static std::string GetTypeString(RouteType type);
  56
  57   TransportRoute();
  58   ~TransportRoute();
  59
  60   RouteType type;
  61   net::IPEndPoint remote_address;
  62   net::IPEndPoint local_address;
  63 };
  64
  65 class Transport : public base::NonThreadSafe {
  66  public:
  67   class EventHandler {
  68    public:
  69     EventHandler() {};
  70     virtual ~EventHandler() {};
  71
  72     // Called when the transport generates a new candidate that needs
  73     // to be passed to the AddRemoteCandidate() method on the remote
  74     // end of the connection.
  75     virtual void OnTransportCandidate(Transport* transport,
  76                                       const cricket::Candidate& candidate) = 0;
  77
  78     // Called when transport route changes. Can be called even before
  79     // the transport is connected.
  80     virtual void OnTransportRouteChange(Transport* transport,
  81                                         const TransportRoute& route) = 0;
  82
  83     // Called when when the transport has failed to connect or reconnect.
  84     virtual void OnTransportFailed(Transport* transport) = 0;
  85
  86     // Called when the transport is about to be deleted.
  87     virtual void OnTransportDeleted(Transport* transport) = 0;
  88   };
  89
  90   Transport() {}
  91   virtual ~Transport() {}
  92
  93   // Intialize the transport with the specified parameters.
  94   // |authenticator| is used to secure and authenticate the connection.
  95   virtual void Initialize(const std::string& name,
  96                           Transport::EventHandler* event_handler,
  97                           scoped_ptr<ChannelAuthenticator> authenticator) = 0;
  98
  99   // Adds |candidate| received from the peer.
 100   virtual void AddRemoteCandidate(const cricket::Candidate& candidate) = 0;
 101
 102   // Name of the channel. It is used to identify the channel and
 103   // disambiguate candidates it generates from candidates generated by
 104   // parallel connections.
 105   virtual const std::string& name() const = 0;
 106
 107   // Returns true if the channel is already connected.
 108   virtual bool is_connected() const = 0;
 109
 110  private:
 111   DISALLOW_COPY_AND_ASSIGN(Transport);
 112 };
 113
 114 class StreamTransport : public Transport {
 115  public:
 116   typedef base::Callback<void(scoped_ptr<net::StreamSocket>)> ConnectedCallback;
 117
 118   StreamTransport() { }
 119   virtual ~StreamTransport() { }
 120
 121   virtual void Connect(const ConnectedCallback& callback) = 0;
 122
 123  private:
 124   DISALLOW_COPY_AND_ASSIGN(StreamTransport);
 125 };
 126
 127 class DatagramTransport : public Transport {
 128  public:
 129   typedef base::Callback<void(scoped_ptr<net::Socket>)> ConnectedCallback;
 130
 131   DatagramTransport() { }
 132   virtual ~DatagramTransport() { }
 133
 134   virtual void Connect(const ConnectedCallback& callback) = 0;
 135
 136  private:
 137   DISALLOW_COPY_AND_ASSIGN(DatagramTransport);
 138 };
 139
 140 class TransportFactory {
 141  public:
 142   TransportFactory() { }
 143   virtual ~TransportFactory() { }
 144
 145   // Called to notify transport factory that a new transport might be created
 146   // soon, e.g. when a new session is being created. Implementation may use it
 147   // to start asynchronous preparation, e.g. fetch a new relay token if
 148   // necessary while the session is being authenticated.
 149   virtual void PrepareTokens() = 0;
 150
 151   virtual scoped_ptr<StreamTransport> CreateStreamTransport() = 0;
 152   virtual scoped_ptr<DatagramTransport> CreateDatagramTransport() = 0;
 153
 154  private:
 155   DISALLOW_COPY_AND_ASSIGN(TransportFactory);
 156 };
 157
 158 }  // namespace protocol
 159 }  // namespace remoting
 160
 161 #endif  // REMOTING_PROTOCOL_TRANSPORT_H_