// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

library fuchsia.overnet.protocol;

using zx;

/// A single message proxied from a Zircon channel over an Overnet stream.
struct ZirconChannelMessage {
    /// Bytes part of the payload.
    vector<uint8>:zx.CHANNEL_MAX_MSG_BYTES bytes;
    /// Handles part of the payload.
    vector<ZirconHandle>:zx.CHANNEL_MAX_MSG_HANDLES handles;
};

/// A single handle to be proxied.
/// Not all Zircon types are supported.
xunion ZirconHandle {
    /// A proxied channel.
    ChannelHandle channel;
    /// A proxied socket.
    SocketHandle socket;
};

/// A proxied channel.
struct ChannelHandle {
    /// The Overnet proxy stream that was created to carry this channel.
    /// The protocol over said stream will be a `ZirconChannel`.
    StreamId stream_id;
};

/// A proxied socket.
struct SocketHandle {
    /// The Overnet proxy stream that was created to carry this socket.
    /// The protocol over said stream will be a `ZirconSocket`.
    StreamId stream_id;
    /// Socket options, per `zx_socket_create`.
    uint32 options;
};


/// Proxy protocol for channels.
/// This protocol is published for each side of the Overnet stream.
[Transport="OvernetInternal"]
protocol ZirconChannel {
    /// Send a message to the stream's peer.
    Message(ZirconChannelMessage message);
};

/// Proxy protocol for sockets.
/// This protocol is published for each side of the Overnet stream.
[Transport="OvernetInternal"]
protocol ZirconSocket {
    /// Send some bytes to the stream's peer.
    /// For datagram sockets, this is one datagram.
    /// For stream sockets, this is the next bundle of bytes.
    Message(vector<uint8> bytes);
    /// Send a control message to the stream's peer.
    Control(vector<uint8> bytes);
    /// Share a handle to the stream's peer (to be collected via zx_socket_accept).
    Share(SocketHandle socket);
};