genode/repos/os/include/uplink_session/uplink_session.h
2023-05-30 12:03:29 +02:00

111 lines
2.9 KiB
C++

/*
* \brief Uplink session interface
* \author Martin Stein
* \date 2020-11-30
*/
/*
* Copyright (C) 2020 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU Affero General Public License version 3.
*/
#ifndef _UPLINK_SESSION__UPLINK_SESSION_H_
#define _UPLINK_SESSION__UPLINK_SESSION_H_
/* Genode includes */
#include <session/session.h>
#include <packet_stream_tx/packet_stream_tx.h>
#include <packet_stream_rx/packet_stream_rx.h>
namespace Uplink {
struct Session;
using Genode::Packet_stream_sink;
using Genode::Packet_stream_source;
typedef Genode::Packet_descriptor Packet_descriptor;
}
/*
* Uplink session interface
*
* An Uplink session corresponds to a network adaptor, which can be used to
* transmit and receive network packets. Payload is communicated over the
* packet-stream interface set up between 'Session_client' and
* 'Session_server'.
*
* Even though the methods 'tx', 'tx_channel', 'rx', and 'rx_channel' are
* specific for the client side of the Uplink session interface, they are part of
* the abstract 'Session' class to enable the client-side use of the Uplink
* interface via a pointer to the abstract 'Session' class. This way, we can
* transparently co-locate the packet-stream server with the client in same
* program.
*/
struct Uplink::Session : Genode::Session
{
enum { QUEUE_SIZE = 1024 };
/*
* Types used by the client stub code and server implementation
*
* The acknowledgement queue has always the same size as the submit
* queue. We access the packet content as a char pointer.
*/
typedef Genode::Packet_stream_policy<Genode::Packet_descriptor,
QUEUE_SIZE, QUEUE_SIZE, char> Policy;
typedef Packet_stream_tx::Channel<Policy> Tx;
typedef Packet_stream_rx::Channel<Policy> Rx;
/**
* \noapi
*/
static const char *service_name() { return "Uplink"; }
/*
* An Uplink session consumes a dataspace capability for the server-side
* session object, a session capability, two packet-stream dataspaces for
* rx and tx, and four signal context capabilities for the data-flow
* signals.
*/
static constexpr unsigned CAP_QUOTA = 8;
virtual ~Session() { }
/**
* Request packet-transmission channel
*/
virtual Tx *tx_channel() { return 0; }
/**
* Request packet-reception channel
*/
virtual Rx *rx_channel() { return 0; }
/**
* Request client-side packet-stream interface of tx channel
*/
virtual Tx::Source *tx() { return 0; }
/**
* Request client-side packet-stream interface of rx channel
*/
virtual Rx::Sink *rx() { return 0; }
/*******************
** RPC interface **
*******************/
GENODE_RPC(Rpc_tx_cap, Genode::Capability<Tx>, _tx_cap);
GENODE_RPC(Rpc_rx_cap, Genode::Capability<Rx>, _rx_cap);
GENODE_RPC_INTERFACE(Rpc_tx_cap, Rpc_rx_cap);
};
#endif /* _UPLINK_SESSION__UPLINK_SESSION_H_ */