// 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.vsock;

using zx;
using fuchsia.hardware.vsock;

/// Collection of objects that represent an open connection.
resource struct ConnectionTransport {
    /// `data` socket that is ultimately given to the underlying vsock driver and
    /// is where all incoming data can be received from.
    zx.handle:SOCKET data;
    /// `Connection` interface that is retained by a vsock service that can be
    /// used to manipulate the state of a connection or perform more complex
    /// operations than just sending and receiving on a socket.
    request<Connection> con;
};

/// Interface for manipulating the state of an active connection.
protocol Connection {
    /// Trigger asynchronous shutdown. The underlying channel will be closed
    /// once shutdown is complete. Shutdown has an implicit barrier as any already
    /// queued sends will complete, but any additional sends will generate errors
    Shutdown();
    /// Send a VMO. The reply indicates that the VMO send has finished and that
    /// data may be queued on the socket again without causing races.
    SendVmo(zx.handle:VMO vmo, uint64 off, uint64 len) -> (zx.status status);
};

/// Interface presented by a listener to accept or reject connections
protocol Acceptor {
    /// The response is either a `ConnectionTransport` to indicate that the connection
    /// is accepted, or none to indicate that it should be rejected.
    Accept(fuchsia.hardware.vsock.Addr addr) -> (ConnectionTransport? con);
};

/// Exposed by a service that can act as a bridge to the underlying vsock driver and
/// provides the ability for listeners to be multiplexed by port and manages dynamic
/// port allocation for outbound connections.
[Discoverable]
protocol Connector {
    /// Attempt to establish a connection to the specified remote cid/port pair.
    /// No local port is specified as an ephemeral one will automatically be allocated.
    Connect(uint32 remote_cid, uint32 remote_port, ConnectionTransport con) -> (zx.status status, uint32 local_port);
    /// Registers a listener for a local port. There can only be one listener for
    /// a single port at a time.
    Listen(uint32 local_port, Acceptor acceptor) -> (zx.status status);
};