/*
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_room.h
* @brief GNUnet MESSENGER service
*/
#ifndef GNUNET_SERVICE_MESSENGER_ROOM_H
#define GNUNET_SERVICE_MESSENGER_ROOM_H
#include "platform.h"
#include "gnunet_cadet_service.h"
#include "gnunet_container_lib.h"
#include "gnunet_crypto_lib.h"
#include "gnunet_identity_service.h"
#include "gnunet_mq_lib.h"
#include "gnunet_messenger_service.h"
#include "gnunet-service-messenger_basement.h"
#include "gnunet-service-messenger_handle.h"
#include "gnunet-service-messenger_message_state.h"
#include "gnunet-service-messenger_list_messages.h"
#include "messenger_api_list_tunnels.h"
#include "gnunet-service-messenger_member_store.h"
#include "gnunet-service-messenger_message_store.h"
#include "gnunet-service-messenger_operation_store.h"
#include "messenger_api_ego.h"
#define GNUNET_MESSENGER_IDLE_DELAY GNUNET_TIME_relative_multiply \
(GNUNET_TIME_relative_get_second_ (), 5)
#define GNUNET_MESSENGER_REQUEST_DELAY GNUNET_TIME_relative_multiply \
(GNUNET_TIME_relative_get_minute_ (), 5)
#define GNUNET_MESSENGER_MERGE_DELAY GNUNET_TIME_relative_multiply \
(GNUNET_TIME_relative_get_second_ (), 30)
struct GNUNET_MESSENGER_SrvTunnel;
struct GNUNET_MESSENGER_MemberSession;
struct GNUNET_MESSENGER_SrvRoom
{
struct GNUNET_MESSENGER_Service *service;
struct GNUNET_MESSENGER_SrvHandle *host;
struct GNUNET_CADET_Port *port;
struct GNUNET_HashCode key;
struct GNUNET_CONTAINER_MultiPeerMap *tunnels;
struct GNUNET_MESSENGER_MemberStore member_store;
struct GNUNET_MESSENGER_MessageStore message_store;
struct GNUNET_MESSENGER_OperationStore operation_store;
struct GNUNET_MESSENGER_ListTunnels basement;
struct GNUNET_MESSENGER_MessageState state;
struct GNUNET_HashCode *peer_message;
struct GNUNET_MESSENGER_ListMessages handling;
struct GNUNET_SCHEDULER_Task *idle;
};
/**
* Creates and allocates a new room for a handle with a given key.
*
* @param[in/out] handle Handle
* @param[in] key Key of room
* @return New room
*/
struct GNUNET_MESSENGER_SrvRoom*
create_room (struct GNUNET_MESSENGER_SrvHandle *handle, const struct GNUNET_HashCode *key);
/**
* Destroys a room and frees its memory fully.
*
* @param[in/out] room Room
*/
void
destroy_room (struct GNUNET_MESSENGER_SrvRoom *room);
/**
* Returns the used member store of a given room.
*
* @param[in/out] room Room
* @return Member store
*/
struct GNUNET_MESSENGER_MemberStore*
get_room_member_store (struct GNUNET_MESSENGER_SrvRoom *room);
/**
* Returns the used message store of a given room.
*
* @param[in/out] room Room
* @return Message store
*/
struct GNUNET_MESSENGER_MessageStore*
get_room_message_store (struct GNUNET_MESSENGER_SrvRoom *room);
/**
* Returns the used operation store of a given room.
*
* @param[in/out] room Room
* @return Operation store
*/
struct GNUNET_MESSENGER_OperationStore*
get_room_operation_store (struct GNUNET_MESSENGER_SrvRoom *room);
/**
* Tries to open a room for a given handle. If the room has already been opened, the handle
* will locally join the room.
*
* Calling this method should result in joining a room and sending a peer message as well for this peer.
*
* If the function returns #GNUNET_YES the port for this room is guaranteed to be open for incoming connections.
*
* @param[in/out] room Room
* @param[in/out] handle Handle
* @return #GNUNET_YES on success, #GNUNET_NO on failure.
*/
int
open_room (struct GNUNET_MESSENGER_SrvRoom *room, struct GNUNET_MESSENGER_SrvHandle *handle);
/**
* Connects a tunnel to a hosting peer of a room through a so called door which is represented by
* a peer identity of a hosting peer. During the connection the handle will join the room as a member, waiting for
* an info message from the selected host.
*
* @param[in/out] room Room
* @param[in/out] handle Handle
* @param[in] door Peer identity
* @return #GNUNET_YES on success, #GNUNET_NO on failure.
*/
int
enter_room_at (struct GNUNET_MESSENGER_SrvRoom *room, struct GNUNET_MESSENGER_SrvHandle *handle,
const struct GNUNET_PeerIdentity *door);
/**
* Packs a message depending on the selected mode into a newly allocated envelope. It will set the
* timestamp of the message, the sender id and the previous messages hash automatically before packing. The message
* will be signed by the handles EGO.
*
* If the optional hash parameter is a valid pointer, its value will be overridden by the signed messages hash.
*
* If mode is set to #GNUNET_MESSENGER_PACK_MODE_ENVELOPE, the function returns a valid envelope to send
* through a message queue, otherwise NULL.
*
* @param[in] room Room
* @param[in] handle Handle
* @param[in/out] message Message
* @param[out] hash Hash of message
* @param[in] mode Packing mode
* @return New envelope or NULL
*/
struct GNUNET_MQ_Envelope*
pack_room_message (const struct GNUNET_MESSENGER_SrvRoom *room, const struct GNUNET_MESSENGER_SrvHandle *handle,
struct GNUNET_MESSENGER_Message *message, struct GNUNET_HashCode *hash, int mode);
/**
* Sends a message from a given handle into a room. The hash parameter will be
* updated with the hash-value resulting from the sent message.
*
* The function handles packing the message automatically and will call linked message-events locally even if
* the message won't be sent to another peer.
*
* The function returns #GNUNET_YES on success, #GNUNET_NO if message is null and
* #GNUNET_SYSERR if the message was known already.
*
* @param[in/out] room Room
* @param[in/out] handle Handle
* @param[in/out] message Message
* @return #GNUNET_YES on success, #GNUNET_NO or #GNUNET_SYSERR otherwise.
*/
int
send_room_message (struct GNUNET_MESSENGER_SrvRoom *room, struct GNUNET_MESSENGER_SrvHandle *handle,
struct GNUNET_MESSENGER_Message *message);
/**
* Forwards a message with a given hash to a specific tunnel inside of a room.
*
* @param[in/out] room Room
* @param[in/out] tunnel Tunnel
* @param[in/out] message Message
* @param[in] hash Hash of message
*/
void
forward_room_message (struct GNUNET_MESSENGER_SrvRoom *room, struct GNUNET_MESSENGER_SrvTunnel *tunnel,
struct GNUNET_MESSENGER_Message *message, const struct GNUNET_HashCode *hash);
/**
* Checks the current state of opening a given room from this peer and re-publishes it
* if necessary to a selected tunnel or to all connected tunnels if necessary or if the
* selected tunnel is NULL.
*
* @param[in/out] room Room
* @param[in/out] tunnel Tunnel
*/
void
check_room_peer_status (struct GNUNET_MESSENGER_SrvRoom *room, struct GNUNET_MESSENGER_SrvTunnel *tunnel);
/**
* Reduces all current forks inside of the message history of a room to one remaining last message
* by merging them down. All merge messages will be sent from a given handle.
*
* @param[in/out] room Room
* @param[in/out] handle Handle
*/
void
merge_room_last_messages (struct GNUNET_MESSENGER_SrvRoom *room, struct GNUNET_MESSENGER_SrvHandle *handle);
/**
* Deletes a message from the room with a given hash in a specific delay if
* the provided member by its session is permitted to do so.
*
* @param[in/out] room Room
* @param[in/out] session Member session
* @param[in] hash Hash of message
* @param[in] delay Delay of deletion
* @return #GNUNET_YES on success, #GNUNET_NO if permission gets denied, #GNUNET_SYSERR on operation failure
*/
int
delete_room_message (struct GNUNET_MESSENGER_SrvRoom *room, struct GNUNET_MESSENGER_MemberSession *session,
const struct GNUNET_HashCode *hash, const struct GNUNET_TIME_Relative delay);
/**
* Returns the CADET handle from a rooms service.
*
* @param[in/out] room Room
* @return CADET handle
*/
struct GNUNET_CADET_Handle*
get_room_cadet (struct GNUNET_MESSENGER_SrvRoom *room);
/**
* Returns the shared secret you need to access a room.
*
* @param[in] room Room
* @return Shared secret
*/
const struct GNUNET_HashCode*
get_room_key (const struct GNUNET_MESSENGER_SrvRoom *room);
/**
* Returns a tunnel inside of a room leading towards a given peer if such a tunnel exists,
* otherwise NULL.
*
* @param[in] room Room
* @param[in] peer Peer identity
* @return Tunnel or NULL
*/
const struct GNUNET_MESSENGER_SrvTunnel*
get_room_tunnel (const struct GNUNET_MESSENGER_SrvRoom *room, const struct GNUNET_PeerIdentity *peer);
/**
* Method called whenever a message is found during a request in a room.
*
* @param[in/out] cls Closure from #request_room_message
* @param[in/out] room Room
* @param[in] message Message or NULL
* @param[in] hash Hash of message
*/
typedef void (GNUNET_MESSENGER_MessageRequestCallback) (
void *cls, struct GNUNET_MESSENGER_SrvRoom *room,
const struct GNUNET_MESSENGER_Message *message,
const struct GNUNET_HashCode *hash
);
/**
* Requests a message from a room identified by a given hash. If the message is found,
* the selected callback will be called with it and the provided closure. If no matching message
* is found but it wasn't deleted the selected callback will be called with #NULL as message instead.
* In case of deletion the next available previous message will be used to call the callback.
*
* It is also possible that the given callback will not be called if the requesting session is not
* permitted!
*
* @param[in/out] room Room
* @param[in] hash Hash of message
* @param[in] callback Callback to process result
* @param[in] cls Closure for the callback
* @return #GNUNET_YES if the request could be processed, otherwise #GNUNET_NO
*/
int
request_room_message (struct GNUNET_MESSENGER_SrvRoom *room, const struct GNUNET_HashCode *hash,
const struct GNUNET_MESSENGER_MemberSession *session,
GNUNET_MESSENGER_MessageRequestCallback callback, void* cls);
/**
* Checks for potential collisions with member ids and solves them changing active handles ids if they
* use an already used member id (comparing public key and timestamp).
*
* @param[in/out] room Room
* @param[in] public_key Public key of EGO
* @param[in] member_id Member ID
* @param[in] timestamp Timestamp
*/
void
solve_room_member_collisions (struct GNUNET_MESSENGER_SrvRoom *room, const struct GNUNET_IDENTITY_PublicKey *public_key,
const struct GNUNET_ShortHashCode *member_id, struct GNUNET_TIME_Absolute timestamp);
/**
* Rebuilds the decentralized structure for a room by ensuring all required connections are made
* depending on the amount of peers and this peers index in the list of them.
*
* @param[in/out] room Room
*/
void
rebuild_room_basement_structure (struct GNUNET_MESSENGER_SrvRoom *room);
/**
* Loads the local configuration for a given room of a service which contains the last messages hash
* and the ruleset for general access of new members.
*
* @param[out] room Room
*/
void
load_room (struct GNUNET_MESSENGER_SrvRoom *room);
/**
* Saves the configuration for a given room of a service which contains the last messages hash
* and the ruleset for general access of new members locally.
*
* @param[in] room Room
*/
void
save_room (struct GNUNET_MESSENGER_SrvRoom *room);
#endif //GNUNET_SERVICE_MESSENGER_ROOM_H