remoting/protocol/session_config.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 #ifndef REMOTING_PROTOCOL_SESSION_CONFIG_H_
   6 #define REMOTING_PROTOCOL_SESSION_CONFIG_H_
   7
   8 #include <list>
   9 #include <string>
  10
  11 #include "base/basictypes.h"
  12 #include "base/memory/scoped_ptr.h"
  13
  14 namespace remoting {
  15 namespace protocol {
  16
  17 extern const int kDefaultStreamVersion;
  18
  19 // Struct for configuration parameters of a single channel.
  20 // Some channels (like video) may have multiple underlying sockets that need
  21 // to be configured simultaneously.
  22 struct ChannelConfig {
  23   enum TransportType {
  24     TRANSPORT_STREAM,
  25     TRANSPORT_MUX_STREAM,
  26     TRANSPORT_DATAGRAM,
  27     TRANSPORT_NONE,
  28   };
  29
  30   enum Codec {
  31     CODEC_UNDEFINED,  // Used for event and control channels.
  32     CODEC_VERBATIM,
  33     CODEC_ZIP,
  34     CODEC_VP8,
  35     CODEC_VP9,
  36     CODEC_OPUS,
  37     CODEC_SPEEX,
  38   };
  39
  40   // Creates a config with transport field set to TRANSPORT_NONE which indicates
  41   // that corresponding channel is disabled.
  42   static ChannelConfig None();
  43
  44   // Default constructor. Equivalent to None().
  45   ChannelConfig();
  46
  47   // Creates a channel config with the specified parameters.
  48   ChannelConfig(TransportType transport, int version, Codec codec);
  49
  50   // operator== is overloaded so that std::find() works with
  51   // std::list<ChannelConfig>.
  52   bool operator==(const ChannelConfig& b) const;
  53
  54   TransportType transport;
  55   int version;
  56   Codec codec;
  57 };
  58
  59 // SessionConfig is used by the chromoting Session to store negotiated
  60 // chromotocol configuration.
  61 class SessionConfig {
  62  public:
  63   SessionConfig();
  64
  65   void set_control_config(const ChannelConfig& control_config) {
  66     control_config_ = control_config;
  67   }
  68   const ChannelConfig& control_config() const { return control_config_; }
  69   void set_event_config(const ChannelConfig& event_config) {
  70     event_config_ = event_config;
  71   }
  72   const ChannelConfig& event_config() const { return event_config_; }
  73   void set_video_config(const ChannelConfig& video_config) {
  74     video_config_ = video_config;
  75   }
  76   const ChannelConfig& video_config() const { return video_config_; }
  77   void set_audio_config(const ChannelConfig& audio_config) {
  78     audio_config_ = audio_config;
  79   }
  80   const ChannelConfig& audio_config() const { return audio_config_; }
  81
  82   bool is_audio_enabled() const {
  83     return audio_config_.transport != ChannelConfig::TRANSPORT_NONE;
  84   }
  85
  86   // Returns true if the control channel supports capabilities.
  87   bool SupportsCapabilities() const;
  88
  89   // Returns a suitable session configuration for use in tests.
  90   static SessionConfig ForTest();
  91
  92  private:
  93   ChannelConfig control_config_;
  94   ChannelConfig event_config_;
  95   ChannelConfig video_config_;
  96   ChannelConfig audio_config_;
  97 };
  98
  99 // Defines session description that is sent from client to the host in the
 100 // session-initiate message. It is different from the regular Config
 101 // because it allows one to specify multiple configurations for each channel.
 102 class CandidateSessionConfig {
 103  public:
 104   static scoped_ptr<CandidateSessionConfig> CreateEmpty();
 105   static scoped_ptr<CandidateSessionConfig> CreateFrom(
 106       const SessionConfig& config);
 107   static scoped_ptr<CandidateSessionConfig> CreateDefault();
 108
 109   ~CandidateSessionConfig();
 110
 111   const std::list<ChannelConfig>& control_configs() const {
 112     return control_configs_;
 113   }
 114
 115   std::list<ChannelConfig>* mutable_control_configs() {
 116     return &control_configs_;
 117   }
 118
 119   const std::list<ChannelConfig>& event_configs() const {
 120     return event_configs_;
 121   }
 122
 123   std::list<ChannelConfig>* mutable_event_configs() {
 124     return &event_configs_;
 125   }
 126
 127   const std::list<ChannelConfig>& video_configs() const {
 128     return video_configs_;
 129   }
 130
 131   std::list<ChannelConfig>* mutable_video_configs() {
 132     return &video_configs_;
 133   }
 134
 135   const std::list<ChannelConfig>& audio_configs() const {
 136     return audio_configs_;
 137   }
 138
 139   std::list<ChannelConfig>* mutable_audio_configs() {
 140     return &audio_configs_;
 141   }
 142
 143   // Selects session configuration that is supported by both participants.
 144   // NULL is returned if such configuration doesn't exist. When selecting
 145   // channel configuration priority is given to the configs listed first
 146   // in |client_config|.
 147   bool Select(const CandidateSessionConfig* client_config,
 148               SessionConfig* result);
 149
 150   // Returns true if |config| is supported.
 151   bool IsSupported(const SessionConfig& config) const;
 152
 153   // Extracts final protocol configuration. Must be used for the description
 154   // received in the session-accept stanza. If the selection is ambiguous
 155   // (e.g. there is more than one configuration for one of the channel)
 156   // or undefined (e.g. no configurations for a channel) then NULL is returned.
 157   bool GetFinalConfig(SessionConfig* result) const;
 158
 159   scoped_ptr<CandidateSessionConfig> Clone() const;
 160
 161   // Helpers for enabling/disabling specific features.
 162   void DisableAudioChannel();
 163   void EnableVideoCodec(ChannelConfig::Codec codec);
 164
 165  private:
 166   CandidateSessionConfig();
 167   explicit CandidateSessionConfig(const CandidateSessionConfig& config);
 168   CandidateSessionConfig& operator=(const CandidateSessionConfig& b);
 169
 170   static bool SelectCommonChannelConfig(
 171       const std::list<ChannelConfig>& host_configs_,
 172       const std::list<ChannelConfig>& client_configs_,
 173       ChannelConfig* config);
 174   static bool IsChannelConfigSupported(const std::list<ChannelConfig>& list,
 175                                        const ChannelConfig& value);
 176
 177   std::list<ChannelConfig> control_configs_;
 178   std::list<ChannelConfig> event_configs_;
 179   std::list<ChannelConfig> video_configs_;
 180   std::list<ChannelConfig> audio_configs_;
 181 };
 182
 183 }  // namespace protocol
 184 }  // namespace remoting
 185
 186 #endif  // REMOTING_PROTOCOL_SESSION_CONFIG_H_