/*
This file is part of GNUnet.
Copyright (C) 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_member_session.h
* @brief GNUnet MESSENGER service
*/
#ifndef GNUNET_SERVICE_MESSENGER_MEMBER_SESSION_H
#define GNUNET_SERVICE_MESSENGER_MEMBER_SESSION_H
#include "platform.h"
#include "gnunet_crypto_lib.h"
#include "gnunet_container_lib.h"
#include "gnunet_identity_service.h"
#include "gnunet_time_lib.h"
#include "gnunet-service-messenger_member.h"
#include "messenger_api_contact.h"
struct GNUNET_MESSENGER_MemberSession {
struct GNUNET_MESSENGER_Member *member;
struct GNUNET_IDENTITY_PublicKey public_key;
struct GNUNET_HashCode context;
struct GNUNET_MESSENGER_Contact *contact;
struct GNUNET_CONTAINER_MultiHashMap *history;
struct GNUNET_MESSENGER_ListMessages messages;
struct GNUNET_MESSENGER_MemberSession* prev;
struct GNUNET_MESSENGER_MemberSession* next;
struct GNUNET_TIME_Absolute start;
int closed;
int completed;
};
/**
* Creates and allocates a new member session of a member with a given
* public key.
*
* If the creation fails, NULL gets returned.
*
* @param[in/out] member Member
* @param[in] pubkey Public key of EGO
* @return New member session
*/
struct GNUNET_MESSENGER_MemberSession*
create_member_session (struct GNUNET_MESSENGER_Member *member,
const struct GNUNET_IDENTITY_PublicKey *pubkey);
/**
* Creates and allocates a new member session closing and replacing a given
* other session of the same member. The new session could have significant
* changes to the members public key or its member id depending on the used
* message to switch session. The new session will be linked to the old
* one.
*
* @param[in/out] session Old member session
* @param[in] message Message
* @param[in] hash Hash of message
* @return New member session
*/
struct GNUNET_MESSENGER_MemberSession*
switch_member_session (struct GNUNET_MESSENGER_MemberSession *session,
const struct GNUNET_MESSENGER_Message *message,
const struct GNUNET_HashCode *hash);
/**
* Destroys a member session and frees its memory fully.
*
* @param[in/out] session Member session
*/
void
destroy_member_session(struct GNUNET_MESSENGER_MemberSession* session);
/**
* Resets a given member session which re-opens a member
* session for new usage. Every connection to other sessions will be
* be dropped. The member sessions messages will be cleared but old
* history from uncompleted sessions however can be reused!
*
* @param[in/out] session Member session
* @param[in] hash Hash of initial message (JOIN message!)
* @return #GNUNET_OK on success, #GNUNET_SYSERR otherwise
*/
int
reset_member_session (struct GNUNET_MESSENGER_MemberSession* session,
const struct GNUNET_HashCode *hash);
/**
* Closes a given member session which opens the request
* for completion of the given member session.
*
* Closing a session may complete a session and can't be used without
* a reset! ( @see #reset_member_session() )
*
* @param[in/out] session Member session
*/
void
close_member_session (struct GNUNET_MESSENGER_MemberSession* session);
/**
* Returns if the given member session has been closed.
*
* @param[in] session Member session
* @return #GNUNET_YES or #GNUNET_NO
*/
int
is_member_session_closed (const struct GNUNET_MESSENGER_MemberSession* session);
/**
* Returns if the given member session has been completed.
*
* A completed member session can't verify any message as its own and
* it won't add any message to its history.
*
* @param[in] session Member session
* @return #GNUNET_YES or #GNUNET_NO
*/
int
is_member_session_completed (const struct GNUNET_MESSENGER_MemberSession* session);
/**
* Returns the timestamp of the member session's start.
*
* @param[in] session Member session
* @return Absolute timestamp
*/
struct GNUNET_TIME_Absolute
get_member_session_start (const struct GNUNET_MESSENGER_MemberSession* session);
/**
* Returns the key of the room a given member session belongs to.
*
* @param[in] session Member session
* @return Key of room
*/
const struct GNUNET_HashCode*
get_member_session_key (const struct GNUNET_MESSENGER_MemberSession* session);
/**
* Returns the member id of a given member session.
*
* @param[in] session Member session
* @return Member id
*/
const struct GNUNET_ShortHashCode*
get_member_session_id (const struct GNUNET_MESSENGER_MemberSession* session);
/**
* Returns the public key from an EGO of a given member session.
*
* @param[in] session Member session
* @return Public key of EGO
*/
const struct GNUNET_IDENTITY_PublicKey*
get_member_session_public_key (const struct GNUNET_MESSENGER_MemberSession* session);
/**
* Returns the member context of a given member session.
*
* @param[in] session Member session
* @return Member context as hash
*/
const struct GNUNET_HashCode*
get_member_session_context (const struct GNUNET_MESSENGER_MemberSession* session);
/**
* Retruns the contact which is connected to a given member session.
*
* @param[in] session Member session
* @return Contact
*/
struct GNUNET_MESSENGER_Contact*
get_member_session_contact (struct GNUNET_MESSENGER_MemberSession* session);
/**
* Verifies a given member session as sender of a selected message and
* its hash. The function returns #GNUNET_OK if the message session is verified
* as sender, otherwise #GNUNET_SYSERR.
*
* @see #is_member_session_completed() for verification.
*
* @param[in] session Member session
* @param[in] message Message
* @param[in] hash Hash of message
* @return #GNUNET_OK on success, otherwise #GNUNET_SYSERR
*/
int
verify_member_session_as_sender (const struct GNUNET_MESSENGER_MemberSession *session,
const struct GNUNET_MESSENGER_Message *message,
const struct GNUNET_HashCode *hash);
/**
* Checks the history of a session for a specific message which is identified
* by its hash and if the ownership flag is set, if the message is
* owned by the sessions contact.
*
* @param[in] session Member session
* @param[in] hash Hash of message
* @param[in] ownership Ownership flag
* @return #GNUNET_YES if found, otherwise #GNUNET_NO
*/
int
check_member_session_history (const struct GNUNET_MESSENGER_MemberSession *session,
const struct GNUNET_HashCode *hash, int ownership);
/**
* Adds a given message to the history of a session using the messages
* hash. The ownership will be set automatically.
*
* @see #is_member_session_completed() for updating a history.
*
* @param[in/out] session Member session
* @param[in] message Message
* @param[in] hash Hash of message
*/
void
update_member_session_history (struct GNUNET_MESSENGER_MemberSession *session,
const struct GNUNET_MESSENGER_Message *message,
const struct GNUNET_HashCode *hash);
/**
* Removes a message from the history of a session using the messages
* hash.
*
* @param[in/out] session Member session
* @param[in] hash Hash of message
*/
void
clear_member_session_history (struct GNUNET_MESSENGER_MemberSession *session,
const struct GNUNET_HashCode *hash);
/**
* Loads data from a directory into a new allocated and created member
* session of a member if the required information can be read from the
* content of the given directory.
*
* @param[out] member Member
* @param[in] directory Path to a directory
*/
void
load_member_session (struct GNUNET_MESSENGER_Member *member, const char *directory);
/**
* Loads the connection from one session to another through the
* next attribute. Necessary information will be loaded from a configuration
* file inside of a given directory.
*
* @param[in/out] session Member session
* @param[in] directory Path to a directory
*/
void
load_member_session_next (struct GNUNET_MESSENGER_MemberSession *session, const char *directory);
/**
* Saves data from a member session into a directory which can be
* load to restore the member session completely.
*
* @param[in] session Member session
* @param[in] directory Path to a directory
*/
void
save_member_session (struct GNUNET_MESSENGER_MemberSession *session, const char *directory);
#endif //GNUNET_SERVICE_MESSENGER_MEMBER_SESSION_H