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: EventHandler()69 EventHandler() {}; ~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 Transport()90 Transport() {} ~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 StreamTransport()118 StreamTransport() { } ~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 DatagramTransport()131 DatagramTransport() { } ~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: TransportFactory()142 TransportFactory() { } ~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_ 162