/* This file is part of libbrandt.
* Copyright (C) 2016 GNUnet e.V.
*
* libbrandt is free software: you can redistribute it and/or modify it under
* the terms of the GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* libbrandt 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with
* libbrandt. If not, see .
*/
/**
* @file brandt.h
* @brief This Header defines the external interface of libbrandt.
*/
#ifndef _BRANDT_BRANDT_H
#define _BRANDT_BRANDT_H
#include
#include
/**
* FIXME.
*/
struct BRANDT_Auction;
/**
* Functions of this type are called by libbrandt to broadcast messages to the
* blackboard of a specific auction.
*
* TODO: how must the message be handled? (encryption, auth, reliability, …)
*
* @param[in] auction_closure Closure pointer representing the respective
* auction. This is the Pointer given to BRANDT_join().
* @param[in] msg The message to be broadcast to all participants of
* @a auction_closure.
* @param[in] msg_len The length of the message @a msg in bytes.
* @return 0 on success, -1 on failure.
*/
typedef int
(*BRANDT_BroadcastCallback)(void * auction_closure,
const void *msg,
size_t msg_len);
/**
* Functions of this type are called by libbrandt to unicast messages to the
* seller of a specific auction.
*
* TODO: how must the message be handled? (encryption, auth, reliability, …)
*
* @param[in] auction_closure Closure pointer representing the respective
* auction. This is the Pointer given to BRANDT_join().
* @param[in] msg The message to be sent to the seller of @a auction_closure.
* @param[in] msg_len The length of the message @a msg in bytes.
* @return 0 on success, -1 on failure.
*/
typedef int
(*BRANDT_UnicastSellerCallback)(void * auction_closure,
const void *msg,
size_t msg_len);
/**
* Functions of this type are called by libbrandt to report the auction outcome
* or malicious/erroneous participants.
*
* TODO: update price type.
* TODO: export proof of erroneous behaviour.
*
* @param[in] auction_closure Closure pointer representing the respective
* auction. This is the Pointer given to BRANDT_join() / BRANDT_new().
* @param[in] bidder_id The numeric Id of the bidder this report refers to.
* @param[in] status 1 if the user @a bidder_id has won the auction, 0 if he has
* lost, -1 if erroneous behaviour was detected.
* @param[in] price The price, the winner has to pay or 0 if the auction result
* is private and the user did not win.
*/
typedef void
(*BRANDT_ReportResultCallback)(void * auction_closure,
unsigned int bidder_id,
int status,
uint16_t price);
void
BRANDT_init ();
/**
* Join an auction described by the @a auction_data parameter.
*
* @param[in] broadcast Pointer to the broadcast callback function
* @param[in] unicast Pointer to the unicast callback function
* @param[in] report Pointer to the report callback function
* @param[in] auction_closure Closure pointer representing the auction. This
* will not be touched by libbrandt. It is only passed to the callbacks.
* @param[in] auction_data The auction information data a an opaque data
* structure. It will be parsed and checked by BRANDT_join().
* @param[in] auction_data_len The length in bytes of the @a auction_data
* structure.
* @return A pointer, which should only be remembered and passed to
* libbrandt functions when the client needs to refer to this auction. This is a
* black-box pointer, do NOT access/change it or the data it points to!
*/
struct BRANDT_Auction *
BRANDT_join (BRANDT_BroadcastCallback broadcast,
BRANDT_UnicastSellerCallback unicast,
BRANDT_ReportResultCallback report,
const void * auction_closure,
const void * auction_data,
size_t auction_data_len);
/* FIXME: where do I specify my bid? */
/* FIXME: Distinguish handles for seller/buyers */
/* FIXME: have cancellation (BRANDT_join_cancel()) */
/* FIXME: provide means to extract a hash from auction data to */
/* tie cryptographic operations to application-readable proposal */
/* FIXME: have separate function to export 'out' variables */
/* FIXME: might want to specify timeout? How do we deal with time? */
/* FIXME: separate creating an auction from starting it; initial */
/* setup needs more auction proposal details (hash, timeout, */
/* bid structure), later we need to know # participants */
/**
* Create a new auction described by the @a auction_data parameter.
*
* @param[in] broadcast Pointer to the broadcast callback function
* @param[in] report Pointer to the report callback function
* @param[in] auction_closure Closure pointer representing the auction. This
* will not be touched by libbrandt. It is only passed to the callbacks.
* @param[out] auction_data The auction information data a an opaque data
* structure. It will be generated by BRANDT_new() and should be distributed to
* all possibly interested bidders.
* @param[out] auction_data_len The length in bytes of the @a auction_data
* structure. Will be filled by BRANDT_new().
* @param[in] num_prices The amount of possible valuations for the sold item(s).
* If 0, a default of 256 will be used. TODO: what about 1, does it work with
* second price auctions?
* @param[in] m The mode of the auction. If 0, it will be a first price auction
* where the winner has to pay the price of his bid. If >0 it will be a second
* price auction selling exactly that amount of items and each winner has to pay
* the price of the highest loosing bid. TODO: what if bidders < m?
* @param[in] outcome_public If 1, the auction winner and price will be public
* to all participants, if 0, this information will only be revealed to the
* winner and the seller. => FIXME: Turn into AuctionMode bit flag!
* @return A pointer, which should only be remembered and passed to
* libbrandt functions when the client needs to refer to this auction. This is a
* black-box pointer, do NOT access/change it or the data it points to!
*/
struct BRANDT_Auction *
BRANDT_new (BRANDT_BroadcastCallback broadcast,
BRANDT_ReportResultCallback report,
const void * auction_closure,
const void ** auction_data,
size_t * auction_data_len,
uint16_t num_prices,
enum BRANDT_AuctionMode m,
int outcome_public);
/**
* Receive a broadcast message related to a specific auction.
*
* @param[in] auction The pointer returned by BRANDT_join() or BRANDT_new() from
* which message @a msg was received.
* @param[in] msg The message that was received.
* @param[in] msg_len The length in bytes of @a msg.
*/
void
BRANDT_got_broadcast (struct BRANDT_Auction *auction,
void * msg,
size_t msg_len);
/**
* Receive a unicast message from a bidder related to a specific auction.
*
* @param[in] auction The pointer returned by BRANDT_new() from which message
* @a msg was received.
* @param[in] msg The message that was received.
* @param[in] msg_len The length in bytes of @a msg.
* TODO: how to link message to sender id within auction?
* ANSWER: on start, know that we have 'n' participants, here give
* participant number (1..n)
*/
void
BRANDT_got_unicast (struct BRANDT_Auction *auction,
void * msg,
size_t msg_len);
/**TODO: Error handling functions? */
#endif /* ifndef _BRANDT_BRANDT_H */