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// Copyright 2019 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CAST_COMMON_CHANNEL_VIRTUAL_CONNECTION_H_
#define CAST_COMMON_CHANNEL_VIRTUAL_CONNECTION_H_
#include <array>
#include <cstdint>
#include <string>
namespace openscreen {
namespace cast {
// Transport system on top of CastSocket that allows routing messages over a
// single socket to different virtual endpoints (e.g. system messages vs.
// messages for a particular app).
struct VirtualConnection {
// Virtual connections can have slightly different semantics for a particular
// endpoint based on its type.
enum class Type {
// Normal connections. Receiver applications should not exit while they
// still have strong connections open (e.g. active senders).
kStrong,
// Same as strong except if the connected endpoint is a receiver
// application, it may stop if its only remaining open connections are all
// weak.
kWeak,
// Receiver applications do not receive connected/disconnected notifications
// about these connections. The following additional conditions apply:
// - Receiver app can still receive "urn:x-cast:com.google.cast.media"
// messages over invisible connections.
// - Receiver app can only send broadcast messages over an invisible
// connection.
kInvisible,
kMinValue = kStrong,
kMaxValue = kInvisible,
};
// Cast V2 protocol version constants. Must be in sync with
// proto/cast_channel.proto.
enum class ProtocolVersion {
kV2_1_0,
kV2_1_1,
kV2_1_2,
kV2_1_3,
};
enum CloseReason {
kUnknown,
kFirstReason = kUnknown,
// Underlying socket has been closed by peer. This happens when Cast sender
// closed transport connection normally without graceful virtual connection
// close. Though it is not an error, graceful virtual connection in advance
// is better.
kTransportClosed,
// Underlying socket has been aborted by peer. Peer is no longer reachable
// because of app crash or network error.
kTransportAborted,
// Messages sent from peer are in wrong format or too long.
kTransportInvalidMessage,
// Underlying socket has been idle for a long period. This only happens when
// heartbeat is enabled and there is a network error.
kTransportTooLongInactive,
// The virtual connection has been closed by this endpoint.
kClosedBySelf,
// The virtual connection has been closed by the peer gracefully.
kClosedByPeer,
kLastReason = kClosedByPeer,
};
struct AssociatedData {
Type type;
std::string user_agent;
// Last two bytes of the peer's IP address, whether IPv4 or IPv6.
std::array<uint8_t, 2> ip_fragment;
ProtocolVersion max_protocol_version;
};
// |local_id| and |peer_id| can be one of several formats:
// - sender-0 or receiver-0: identifies the appropriate platform endpoint of
// the device. Authentication and transport-related messages use these.
// - sender-12345: Possible form of a Cast sender ID. The number portion is
// randomly generated and intended to be unique within that device.
// - Random decimal number: Possible form of a Cast sender ID. Also randomly
// generated and intended to be unique within that device.
// - GUID-style hex string: Random string identifying a particular receiver
// app on the device.
std::string local_id;
std::string peer_id;
int32_t socket_id;
};
inline bool operator==(const VirtualConnection& a, const VirtualConnection& b) {
return a.local_id == b.local_id && a.peer_id == b.peer_id &&
a.socket_id == b.socket_id;
}
inline bool operator!=(const VirtualConnection& a, const VirtualConnection& b) {
return !(a == b);
}
} // namespace cast
} // namespace openscreen
#endif // CAST_COMMON_CHANNEL_VIRTUAL_CONNECTION_H_
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