/*
This file is part of TALER
Copyright (C) 2014-2017 Inria & GNUnet e.V.
TALER 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, or (at your option) any later version.
TALER 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
TALER; see the file COPYING. If not, see
*/
/**
* @file taler-exchange-httpd_refresh_link.c
* @brief Handle /refresh/link requests
* @author Florian Dold
* @author Benedikt Mueller
* @author Christian Grothoff
*/
#include "platform.h"
#include
#include
#include
#include "taler-exchange-httpd_parsing.h"
#include "taler-exchange-httpd_mhd.h"
#include "taler-exchange-httpd_refresh_link.h"
#include "taler-exchange-httpd_responses.h"
#include "taler-exchange-httpd_keystate.h"
/**
* @brief Information for each session a coin was melted into.
*/
struct TEH_RESPONSE_LinkSessionInfo
{
/**
* Transfer public key of the coin.
*/
struct TALER_TransferPublicKeyP transfer_pub;
/**
* Linked data of coins being created in the session.
*/
struct TALER_EXCHANGEDB_LinkDataList *ldl;
};
/**
* Closure for #handle_transfer_data().
*/
struct HTD_Context
{
/**
* Public key of the coin that we are tracing.
*/
struct TALER_CoinSpendPublicKeyP coin_pub;
/**
* Session link data we collect.
*/
struct TEH_RESPONSE_LinkSessionInfo *sessions;
/**
* Database session. Nothing to do with @a sessions.
*/
struct TALER_EXCHANGEDB_Session *session;
/**
* MHD connection, for queueing replies.
*/
struct MHD_Connection *connection;
/**
* Number of sessions the coin was melted into.
*/
unsigned int num_sessions;
/**
* How are we expected to proceed. #GNUNET_SYSERR if we
* failed to return an error (should return #MHD_NO).
* #GNUNET_NO if we succeeded in queueing an MHD error
* (should return #MHD_YES from #TEH_execute_refresh_link),
* #GNUNET_OK if we should call #reply_refresh_link_success().
*/
int status;
};
/**
* Send a response for "/refresh/link".
*
* @param connection the connection to send the response to
* @param num_sessions number of sessions the coin was used in
* @param sessions array of @a num_session entries with
* information for each session
* @return a MHD result code
*/
static int
reply_refresh_link_success (struct MHD_Connection *connection,
unsigned int num_sessions,
const struct TEH_RESPONSE_LinkSessionInfo *sessions)
{
json_t *mlist;
int res;
mlist = json_array ();
for (unsigned int i=0;inext)
{
json_t *obj;
obj = json_object ();
json_object_set_new (obj,
"denom_pub",
GNUNET_JSON_from_rsa_public_key (pos->denom_pub.rsa_public_key));
json_object_set_new (obj,
"ev_sig",
GNUNET_JSON_from_rsa_signature (pos->ev_sig.rsa_signature));
GNUNET_assert (0 ==
json_array_append_new (list,
obj));
}
root = json_object ();
json_object_set_new (root,
"new_coins",
list);
json_object_set_new (root,
"transfer_pub",
GNUNET_JSON_from_data_auto (&sessions[i].transfer_pub));
GNUNET_assert (0 ==
json_array_append_new (mlist,
root));
}
res = TEH_RESPONSE_reply_json (connection,
mlist,
MHD_HTTP_OK);
json_decref (mlist);
return res;
}
/**
* Function called with the session hashes and transfer secret
* information for a given coin. Gets the linkage data and
* builds the reply for the client.
*
*
* @param cls closure, a `struct HTD_Context`
* @param session_hash a session the coin was melted in
* @param transfer_pub public transfer key for the session
*/
static void
handle_transfer_data (void *cls,
const struct GNUNET_HashCode *session_hash,
const struct TALER_TransferPublicKeyP *transfer_pub)
{
struct HTD_Context *ctx = cls;
struct TALER_EXCHANGEDB_LinkDataList *ldl;
struct TEH_RESPONSE_LinkSessionInfo *lsi;
enum GNUNET_DB_QueryStatus qs;
if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT != ctx->status)
return;
ldl = NULL;
qs = TEH_plugin->get_link_data_list (TEH_plugin->cls,
ctx->session,
session_hash,
&ldl);
if (qs <= 0)
{
if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == qs)
ctx->status = GNUNET_DB_STATUS_HARD_ERROR;
else
ctx->status = qs;
return;
}
GNUNET_assert (NULL != ldl);
GNUNET_array_grow (ctx->sessions,
ctx->num_sessions,
ctx->num_sessions + 1);
lsi = &ctx->sessions[ctx->num_sessions - 1];
lsi->transfer_pub = *transfer_pub;
lsi->ldl = ldl;
}
/**
* Free session data kept in @a ctx
*
* @param ctx context to clean up
*/
static void
purge_context (struct HTD_Context *ctx)
{
for (unsigned int i=0;inum_sessions;i++)
TEH_plugin->free_link_data_list (TEH_plugin->cls,
ctx->sessions[i].ldl);
GNUNET_free_non_null (ctx->sessions);
ctx->sessions = NULL;
ctx->num_sessions = 0;
}
/**
* Execute a "/refresh/link". Returns the linkage information that
* will allow the owner of a coin to follow the refresh trail to
* the refreshed coin.
*
* If it returns a non-error code, the transaction logic MUST
* NOT queue a MHD response. IF it returns an hard error, the
* transaction logic MUST queue a MHD response and set @a mhd_ret. IF
* it returns the soft error code, the function MAY be called again to
* retry and MUST not queue a MHD response.
*
* @param cls closure
* @param connection MHD request which triggered the transaction
* @param session database session to use
* @param[out] mhd_ret set to MHD response status for @a connection,
* if transaction failed (!)
* @return transaction status
*/
static enum GNUNET_DB_QueryStatus
refresh_link_transaction (void *cls,
struct MHD_Connection *connection,
struct TALER_EXCHANGEDB_Session *session,
int *mhd_ret)
{
struct HTD_Context *ctx = cls;
enum GNUNET_DB_QueryStatus qs;
ctx->session = session;
ctx->status = GNUNET_DB_STATUS_SUCCESS_ONE_RESULT;
qs = TEH_plugin->get_transfer (TEH_plugin->cls,
session,
&ctx->coin_pub,
&handle_transfer_data,
ctx);
ctx->session = NULL;
if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == qs)
{
*mhd_ret = TEH_RESPONSE_reply_arg_unknown (connection,
TALER_EC_REFRESH_LINK_COIN_UNKNOWN,
"coin_pub");
return GNUNET_DB_STATUS_HARD_ERROR;
}
if (0 < qs)
{
qs = ctx->status;
if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == qs)
{
*mhd_ret = TEH_RESPONSE_reply_json_pack (ctx->connection,
MHD_HTTP_NOT_FOUND,
"{s:s}",
"error",
"link data not found (link)");
return GNUNET_DB_STATUS_HARD_ERROR;
}
return qs;
}
purge_context (ctx);
return qs;
}
/**
* Handle a "/refresh/link" request. Note that for "/refresh/link"
* we do use a simple HTTP GET, and a HTTP POST!
*
* @param rh context of the handler
* @param connection the MHD connection to handle
* @param[in,out] connection_cls the connection's closure (can be updated)
* @param upload_data upload data
* @param[in,out] upload_data_size number of bytes (left) in @a upload_data
* @return MHD result code
*/
int
TEH_REFRESH_handler_refresh_link (struct TEH_RequestHandler *rh,
struct MHD_Connection *connection,
void **connection_cls,
const char *upload_data,
size_t *upload_data_size)
{
int mhd_ret;
int res;
struct HTD_Context ctx;
memset (&ctx,
0,
sizeof (ctx));
res = TEH_PARSE_mhd_request_arg_data (connection,
"coin_pub",
&ctx.coin_pub,
sizeof (struct TALER_CoinSpendPublicKeyP));
if (GNUNET_SYSERR == res)
return MHD_NO;
if (GNUNET_OK != res)
return MHD_YES;
if (GNUNET_OK !=
TEH_DB_run_transaction (connection,
&mhd_ret,
&refresh_link_transaction,
&ctx))
{
purge_context (&ctx);
return mhd_ret;
}
mhd_ret = reply_refresh_link_success (connection,
ctx.num_sessions,
ctx.sessions);
purge_context (&ctx);
return mhd_ret;
}
/* end of taler-exchange-httpd_refresh_link.c */