/*
This file is part of GNUnet.
Copyright (C) 2020--2021 GNUnet e.V.
GNUnet is free software: you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License,
or (at your option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see .
SPDX-License-Identifier: AGPL3.0-or-later
*/
/**
* @author Tobias Frisch
* @file src/messenger/gnunet-service-messenger_tunnel.h
* @brief GNUnet MESSENGER service
*/
#ifndef GNUNET_SERVICE_MESSENGER_TUNNEL_H
#define GNUNET_SERVICE_MESSENGER_TUNNEL_H
#include "platform.h"
#include "gnunet_cadet_service.h"
#include "gnunet_peer_lib.h"
#include "gnunet_crypto_lib.h"
#include "gnunet-service-messenger_room.h"
#include "gnunet-service-messenger_message_state.h"
struct GNUNET_MESSENGER_SrvTunnel
{
struct GNUNET_MESSENGER_SrvRoom *room;
struct GNUNET_CADET_Channel *channel;
GNUNET_PEER_Id peer;
uint32_t messenger_version;
struct GNUNET_HashCode *peer_message;
struct GNUNET_MESSENGER_MessageState state;
};
/**
* Creates and allocates a tunnel of a room to a specific peer identity (called door).
*
* @param[in/out] room Room
* @param[in] door Peer identity
* @return New tunnel
*/
struct GNUNET_MESSENGER_SrvTunnel*
create_tunnel (struct GNUNET_MESSENGER_SrvRoom *room,
const struct GNUNET_PeerIdentity *door);
/**
* Destroys a tunnel and frees its memory fully.
*
* @param[in/out] tunnel
*/
void
destroy_tunnel (struct GNUNET_MESSENGER_SrvTunnel *tunnel);
/**
* Binds a CADET channel to a tunnel and replaces its channel
* the tunnel is currently bound to if necessary.
*
* @param[in/out] tunnel Tunnel
* @param[in/out] channel CADET channel
*/
void
bind_tunnel (struct GNUNET_MESSENGER_SrvTunnel *tunnel,
struct GNUNET_CADET_Channel *channel);
/**
* Tries to connect a tunnel by creating a new CADET channel and binding it.
* The function returns #GNUNET_YES on success, otherwise #GNUNET_NO.
*
* @param[in/out] tunnel Tunnel
* @return #GNUNET_YES on success, otherwise #GNUNET_NO
*/
int
connect_tunnel (struct GNUNET_MESSENGER_SrvTunnel *tunnel);
/**
* Disconnects and unbinds a channel from a tunnel. The actual disconnection
* will be asynchronous.
*
* @param[in/out] tunnel Tunnel
*/
void
disconnect_tunnel (struct GNUNET_MESSENGER_SrvTunnel *tunnel);
/**
* Returns the status of a currently bound channel of a tunnel.
*
* @param[in] tunnel Tunnel
* @return #GNUNET_YES or #GNUNET_NO
*/
int
is_tunnel_connected (const struct GNUNET_MESSENGER_SrvTunnel *tunnel);
/**
* Sends an envelope containing a message with a given hash through
* a tunnel.
*
* @param[in/out] tunnel Tunnel
* @param[in/out] env Envelope
* @param[in] hash Hash of message
*/
void
send_tunnel_envelope (struct GNUNET_MESSENGER_SrvTunnel *tunnel,
struct GNUNET_MQ_Envelope *env,
const struct GNUNET_HashCode *hash);
/**
* Sends a message by packing it automatically into an envelope and passing it
* through the tunnel. The used handle will sign the message and
* the hash will be calculated and stored.
*
* @param[in/out] tunnel Tunnel
* @param[in/out] handle Handle
* @param[in/out] message Message
* @return #GNUNET_YES on success, GNUNET_NO otherwise
*/
int
send_tunnel_message (struct GNUNET_MESSENGER_SrvTunnel *tunnel,
void *handle,
struct GNUNET_MESSENGER_Message *message);
/**
* Forwards a given message with a known hash through a tunnel.
*
* @param[in/out] tunnel Tunnel
* @param[in] message Message
* @param[in] hash Hash of message
*/
void
forward_tunnel_message (struct GNUNET_MESSENGER_SrvTunnel *tunnel,
const struct GNUNET_MESSENGER_Message *message,
const struct GNUNET_HashCode *hash);
/**
* Returns the hash of the latest peer message published through a given tunnel
* and matching the tunnels peer identity. If no peer message has been linked to the tunnel
* yet, NULL gets returned.
*
* @param[in] tunnel Tunnel
* @return Hash of peer message or NULL
*/
const struct GNUNET_HashCode*
get_tunnel_peer_message (const struct GNUNET_MESSENGER_SrvTunnel *tunnel);
/**
* Writes the peer identity of the peer connected via tunnel to this peer into
* the peer parameter.
*
* @param[in] tunnel Tunnel
* @param[out] peer Peer identity
*/
void
get_tunnel_peer_identity (const struct GNUNET_MESSENGER_SrvTunnel *tunnel,
struct GNUNET_PeerIdentity *peer);
/**
* Returns the current messenger version the peer connected via a given tunnel
* has reported to be using if it was compatible during updating.
*
* @see update_tunnel_messenger_version
*
* @param[in] tunnel Tunnel
* @return Version of messenger
*/
uint32_t
get_tunnel_messenger_version (const struct GNUNET_MESSENGER_SrvTunnel *tunnel);
/**
* Updates the messenger version of the tunnel to a given version if
* it is compatible to the running peer of the service. Depending on success it
* returns #GNUNET_OK or #GNUNET_SYSERR on failure.
*
* @param[in/out] tunnel Tunnel
* @param[in] version Version of messenger
*/
int
update_tunnel_messenger_version (struct GNUNET_MESSENGER_SrvTunnel *tunnel,
uint32_t version);
#endif //GNUNET_SERVICE_MESSENGER_TUNNEL_H