chrome/common/extensions/api/cast_channel.idl

   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 // API for communicating with a Google Cast device over an authenticated
   6 // channel.
   7 namespace cast.channel {
   8
   9   // The state of the channel.
  10   enum ReadyState {
  11     // The channel is connecting.
  12     connecting,
  13     // The channel is open and available for messaging.
  14     open,
  15     // The channel is closing.
  16     closing,
  17     // The channel is closed.
  18     closed
  19   };
  20
  21   // Error conditions that the channel may encounter.  All error conditions
  22   // are terminal.  When an error condition is encountered the API will:
  23   // (1) Transition the channel to readyState == 'closed'.
  24   // (2) Set ChannelInfo.lastError to the error condition.
  25   // (3) Fire an onError event with the error condition.
  26   // (4) Fire an onClose event.
  27   enum ChannelError {
  28     // cast.channel.send() was called when ChannelInfo.readyState != 'open'.
  29     channel_not_open,
  30     // Authentication was requested and the receiver could not be
  31     // authenticated (invalid signature, invalid handhake, TLS error, etc.)
  32     authentication_error,
  33     // A new channel could not be created for reasons unrelated to
  34     // authentication (e.g., there is already an open channel to the same URL).
  35     connect_error,
  36     // There was an error writing or reading from the underlying socket.
  37     socket_error,
  38     // A transport level occurred (like an unparseable message).
  39     transport_error,
  40     // The client attempted to send an unsupported message type through the
  41     // channel.
  42     invalid_message,
  43     // An invalid channel id was passed.
  44     invalid_channel_id,
  45     // Unspecified error.
  46     unknown
  47   };
  48
  49   // Authentication methods that may be required to connect to a Cast receiver.
  50   enum ChannelAuthType {
  51     // SSL over TCP.
  52     ssl,
  53     // SSL over TCP with challenge and receiver signature verification.
  54     ssl_verified
  55   };
  56
  57   // Describes the information needed to connect to a Cast receiver.
  58   // This replaces the prior use of cast:// and casts:// URLs.
  59   dictionary ConnectInfo {
  60     // The IPV4 address of the Cast receiver, e.g. '198.1.0.2'.
  61     // TODO(mfoltz): Investigate whether IPV6 addresses "just work."
  62     DOMString ipAddress;
  63
  64     // The port number to connect to, 0-65535.
  65     long port;
  66
  67     // The authentication method required for the channel.
  68     ChannelAuthType auth;
  69   };
  70
  71   // Describes the state of a channel to a Cast receiver.
  72   dictionary ChannelInfo {
  73     // Id for the channel.
  74     long channelId;
  75
  76     // DEPRECATED: The URL to the receiver.  This field will be removed in a
  77     // future release.
  78     DOMString url;
  79
  80     // Connection information that was used to establish the channel to the
  81     // receiver.
  82     ConnectInfo connectInfo;
  83
  84     // The current state of the channel.
  85     ReadyState readyState;
  86
  87     // If set, the last error condition encountered by the channel.
  88     ChannelError? errorState;
  89   };
  90
  91   // Describes a message sent or received over the channel.  Currently only
  92   // string messages are supported, although ArrayBuffer and Blob types may be
  93   // supported in the future.
  94   dictionary MessageInfo {
  95     // The message namespace.  A namespace is a URN of the form
  96     // urn:cast-x:<namespace> that is used to interpret and route Cast messages.
  97     DOMString namespace_;
  98
  99     // source and destination ids identify the origin and destination of the
 100     // message.  They are used to route messages between endpoints that share a
 101     // device-to-device channel.
 102     //
 103     // For messages between applications:
 104     //   - The sender application id is a unique identifier generated on behalf
 105     //     of the sender application.
 106     //   - The receiver id is always the the session id for the application.
 107     //
 108     // For messages to or from the sender or receiver platform, the special ids
 109     // 'sender-0' and 'receiver-0' can be used.
 110     //
 111     // For messages intended for all endpoints using a given channel, the
 112     // wildcard destination_id '*' can be used.
 113     DOMString sourceId;
 114     DOMString destinationId;
 115
 116     // The content of the message.  Must be either a string or an ArrayBuffer.
 117     any data;
 118   };
 119
 120   // Callback holding the result of a channel operation.
 121   callback ChannelInfoCallback = void (ChannelInfo result);
 122
 123   interface Functions {
 124     // Opens a new channel to the Cast receiver specified by connectInfo.  Only
 125     // one channel may be connected to same receiver from the same extension at
 126     // a time.  If the open request is successful, the callback will be invoked
 127     // with a ChannelInfo with readyState == 'connecting'.  If unsuccessful, the
 128     // callback will be invoked with a ChannelInfo with channel.readyState ==
 129     // 'closed' and channel.errorState will be set to the error condition.
 130     //
 131     // TODO(mfoltz): Convert 'any' to ConnectInfo once all clients are updated
 132     // to not send URLs.
 133     static void open(any connectInfo,
 134                      ChannelInfoCallback callback);
 135
 136     // Sends a message on the channel and invokes callback with the resulting
 137     // channel status.  The channel must be in readyState == 'open'.  If
 138     // unsuccessful, channel.readyState will be set to 'closed',
 139     // channel.errorState will be set to the error condition.
 140     static void send(ChannelInfo channel,
 141                      MessageInfo message,
 142                      ChannelInfoCallback callback);
 143
 144     // Requests that the channel be closed and invokes callback with the
 145     // resulting channel status.  The channel must be in readyState == 'open' or
 146     // 'connecting'.  If successful, onClose will be fired with readyState ==
 147     // 'closed'.  If unsuccessful, channel.readyState will be set to 'closed',
 148     // and channel.errorState will be set to the error condition.
 149     static void close(ChannelInfo channel,
 150                       ChannelInfoCallback callback);
 151   };
 152
 153   // Events on the channel.
 154   interface Events {
 155     // Fired when a message is received on an open channel.
 156     static void onMessage(ChannelInfo channel,
 157                           MessageInfo message);
 158
 159     // Fired when an error occurs as a result of a channel method or a network
 160     // event.
 161     static void onError(ChannelInfo channel);
 162   };
 163 };