/*
This file is part of TALER
Copyright (C) 2016, 2017 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-aggregator.c
* @brief Process that aggregates outgoing transactions and executes them
* @author Christian Grothoff
*/
#include "platform.h"
#include
#include
#include
#include "taler_exchangedb_lib.h"
#include "taler_exchangedb_plugin.h"
#include "taler_json_lib.h"
#include "taler_wire_lib.h"
/**
* Information we keep for each loaded wire plugin.
*/
struct WirePlugin
{
/**
* Plugins are kept in a DLL.
*/
struct WirePlugin *next;
/**
* Plugins are kept in a DLL.
*/
struct WirePlugin *prev;
/**
* Handle to the plugin.
*/
struct TALER_WIRE_Plugin *wire_plugin;
/**
* Name of the plugin.
*/
char *type;
/**
* Wire transfer fee structure.
*/
struct TALER_EXCHANGEDB_AggregateFees *af;
};
/**
* Data we keep to #run_transfers(). There is at most
* one of these around at any given point in time.
*/
struct WirePrepareData
{
/**
* Database session for all of our transactions.
*/
struct TALER_EXCHANGEDB_Session *session;
/**
* Wire execution handle.
*/
struct TALER_WIRE_ExecuteHandle *eh;
/**
* Wire plugin used for this preparation.
*/
struct WirePlugin *wp;
/**
* Row ID of the transfer.
*/
unsigned long long row_id;
};
/**
* Information about one aggregation process to be executed. There is
* at most one of these around at any given point in time.
*/
struct AggregationUnit
{
/**
* Public key of the merchant.
*/
struct TALER_MerchantPublicKeyP merchant_pub;
/**
* Total amount to be transferred, before subtraction of @e wire_fee and rounding down.
*/
struct TALER_Amount total_amount;
/**
* Final amount to be transferred (after fee and rounding down).
*/
struct TALER_Amount final_amount;
/**
* Wire fee we charge for @e wp at @e execution_time.
*/
struct TALER_Amount wire_fee;
/**
* Hash of @e wire.
*/
struct GNUNET_HashCode h_wire;
/**
* Wire transfer identifier we use.
*/
struct TALER_WireTransferIdentifierRawP wtid;
/**
* Row ID of the transaction that started it all.
*/
unsigned long long row_id;
/**
* The current time.
*/
struct GNUNET_TIME_Absolute execution_time;
/**
* Wire details of the merchant.
*/
json_t *wire;
/**
* Wire plugin to be used for the preparation.
*/
struct WirePlugin *wp;
/**
* Database session for all of our transactions.
*/
struct TALER_EXCHANGEDB_Session *session;
/**
* Wire preparation handle.
*/
struct TALER_WIRE_PrepareHandle *ph;
/**
* Array of #aggregation_limit row_ids from the
* aggregation.
*/
unsigned long long *additional_rows;
/**
* Offset specifying how many #additional_rows are in use.
*/
unsigned int rows_offset;
/**
* Set to #GNUNET_YES if we have to abort due to failure.
*/
int failed;
};
/**
* Context we use while closing a reserve.
*/
struct CloseTransferContext
{
/**
* Handle for preparing the wire transfer.
*/
struct TALER_WIRE_PrepareHandle *ph;
/**
* Our database session.
*/
struct TALER_EXCHANGEDB_Session *session;
/**
* Wire transfer method.
*/
char *type;
};
/**
* Active context while processing reserve closing,
* or NULL.
*/
static struct CloseTransferContext *ctc;
/**
* Which currency is used by this exchange?
*/
static char *exchange_currency_string;
/**
* What is the base URL of this exchange?
*/
static char *exchange_base_url;
/**
* The exchange's configuration (global)
*/
static struct GNUNET_CONFIGURATION_Handle *cfg;
/**
* Our DB plugin.
*/
static struct TALER_EXCHANGEDB_Plugin *db_plugin;
/**
* Head of list of loaded wire plugins.
*/
static struct WirePlugin *wp_head;
/**
* Tail of list of loaded wire plugins.
*/
static struct WirePlugin *wp_tail;
/**
* Next task to run, if any.
*/
static struct GNUNET_SCHEDULER_Task *task;
/**
* If we are currently executing a transfer, information about
* the active transfer is here. Otherwise, this variable is NULL.
*/
static struct WirePrepareData *wpd;
/**
* If we are currently aggregating transactions, information about the
* active aggregation is here. Otherwise, this variable is NULL.
*/
static struct AggregationUnit *au;
/**
* Value to return from main(). #GNUNET_OK on success, #GNUNET_SYSERR
* on serious errors.
*/
static int global_ret;
/**
* #GNUNET_YES if we are in test mode and should exit when idle.
*/
static int test_mode;
/**
* Did #run_reserve_closures() have any work during its last run?
*/
static int reserves_idle;
/**
* Limit on the number of transactions we aggregate at once. Note
* that the limit must be big enough to ensure that when transactions
* of the smallest possible unit are aggregated, they do surpass the
* "tiny" threshold beyond which we never trigger a wire transaction!
*
* Note: do not change here, Postgres requires us to hard-code the
* LIMIT in the prepared statement.
*/
static unsigned int aggregation_limit = TALER_EXCHANGEDB_MATCHING_DEPOSITS_LIMIT;
/**
* Extract wire plugin type from @a wire address
*
* @param wire a wire address
* @return NULL if @a wire is ill-formed
*/
const char *
extract_type (const json_t *wire)
{
const char *type;
json_t *t;
t = json_object_get (wire, "type");
if (NULL == t)
{
GNUNET_break (0);
return NULL;
}
type = json_string_value (t);
if (NULL == type)
{
GNUNET_break (0);
return NULL;
}
return type;
}
/**
* Advance the "af" pointer in @a wp to point to the
* currently valid record.
*
* @param wp wire transfer fee data structure to update
* @param now timestamp to update fees to
*/
static void
advance_fees (struct WirePlugin *wp,
struct GNUNET_TIME_Absolute now)
{
struct TALER_EXCHANGEDB_AggregateFees *af;
/* First, try to see if we have current fee information in memory */
af = wp->af;
while ( (NULL != af) &&
(af->end_date.abs_value_us < now.abs_value_us) )
{
struct TALER_EXCHANGEDB_AggregateFees *n = af->next;
GNUNET_free (af);
af = n;
}
wp->af = af;
}
/**
* Update wire transfer fee data structure in @a wp.
*
* @param wp wire transfer fee data structure to update
* @param now timestamp to update fees to
* @param session DB session to use
* @return #GNUNET_OK on success, #GNUNET_SYSERR if we
* lack current fee information (and need to exit)
*/
static int
update_fees (struct WirePlugin *wp,
struct GNUNET_TIME_Absolute now,
struct TALER_EXCHANGEDB_Session *session)
{
advance_fees (wp,
now);
if (NULL != wp->af)
return GNUNET_OK;
/* Let's try to load it from disk... */
wp->af = TALER_EXCHANGEDB_fees_read (cfg,
wp->type);
advance_fees (wp,
now);
for (struct TALER_EXCHANGEDB_AggregateFees *p = wp->af;
NULL != p;
p = p->next)
{
if (GNUNET_SYSERR ==
db_plugin->insert_wire_fee (db_plugin->cls,
session,
wp->type,
p->start_date,
p->end_date,
&p->wire_fee,
&p->master_sig))
{
TALER_EXCHANGEDB_fees_free (wp->af);
wp->af = NULL;
return GNUNET_SYSERR;
}
}
if (NULL != wp->af)
return GNUNET_OK;
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Failed to find current wire transfer fees for `%s'\n",
wp->type);
return GNUNET_SYSERR;
}
/**
* Find the wire plugin for the given wire address.
*
* @param type wire plugin type we need a plugin for
* @return NULL on error
*/
static struct WirePlugin *
find_plugin (const char *type)
{
struct WirePlugin *wp;
if (NULL == type)
return NULL;
for (wp = wp_head; NULL != wp; wp = wp->next)
if (0 == strcmp (type,
wp->type))
return wp;
wp = GNUNET_new (struct WirePlugin);
wp->wire_plugin = TALER_WIRE_plugin_load (cfg,
type);
if (NULL == wp->wire_plugin)
{
fprintf (stderr,
"Failed to load wire plugin for `%s'\n",
type);
GNUNET_free (wp);
return NULL;
}
wp->type = GNUNET_strdup (type);
GNUNET_CONTAINER_DLL_insert (wp_head,
wp_tail,
wp);
return wp;
}
/**
* We're being aborted with CTRL-C (or SIGTERM). Shut down.
*
* @param cls closure
*/
static void
shutdown_task (void *cls)
{
struct WirePlugin *wp;
if (NULL != task)
{
GNUNET_SCHEDULER_cancel (task);
task = NULL;
}
if (NULL != wpd)
{
if (NULL != wpd->eh)
{
wpd->wp->wire_plugin->execute_wire_transfer_cancel (wpd->wp->wire_plugin->cls,
wpd->eh);
wpd->eh = NULL;
}
db_plugin->rollback (db_plugin->cls,
wpd->session);
GNUNET_free (wpd);
wpd = NULL;
}
if (NULL != au)
{
if (NULL != au->ph)
{
au->wp->wire_plugin->prepare_wire_transfer_cancel (au->wp->wire_plugin->cls,
au->ph);
au->ph = NULL;
}
db_plugin->rollback (db_plugin->cls,
au->session);
GNUNET_free_non_null (au->additional_rows);
if (NULL != au->wire)
json_decref (au->wire);
au = NULL;
GNUNET_free (au);
}
TALER_EXCHANGEDB_plugin_unload (db_plugin);
while (NULL != (wp = wp_head))
{
GNUNET_CONTAINER_DLL_remove (wp_head,
wp_tail,
wp);
TALER_WIRE_plugin_unload (wp->wire_plugin);
TALER_EXCHANGEDB_fees_free (wp->af);
GNUNET_free (wp->type);
GNUNET_free (wp);
}
GNUNET_CONFIGURATION_destroy (cfg);
cfg = NULL;
}
/**
* Parse configuration parameters for the exchange server into the
* corresponding global variables.
*
* @return #GNUNET_OK on success
*/
static int
exchange_serve_process_config ()
{
if (GNUNET_OK !=
GNUNET_CONFIGURATION_get_value_string (cfg,
"taler",
"currency",
&exchange_currency_string))
{
GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
"taler",
"currency");
return GNUNET_SYSERR;
}
if (strlen (exchange_currency_string) >= TALER_CURRENCY_LEN)
{
fprintf (stderr,
"Currency `%s' longer than the allowed limit of %u characters.",
exchange_currency_string,
(unsigned int) TALER_CURRENCY_LEN);
return GNUNET_SYSERR;
}
if (NULL ==
(db_plugin = TALER_EXCHANGEDB_plugin_load (cfg)))
{
fprintf (stderr,
"Failed to initialize DB subsystem\n");
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* Function called with details about deposits that have been made,
* with the goal of executing the corresponding wire transaction.
*
* @param cls NULL
* @param row_id identifies database entry
* @param merchant_pub public key of the merchant
* @param coin_pub public key of the coin
* @param amount_with_fee amount that was deposited including fee
* @param deposit_fee amount the exchange gets to keep as transaction fees
* @param h_contract_terms hash of the proposal data known to merchant and customer
* @param wire_deadline by which the merchant adviced that he would like the
* wire transfer to be executed
* @param wire wire details for the merchant
* @return #GNUNET_OK to continue to iterate, #GNUNET_SYSERR to stop
*/
static int
deposit_cb (void *cls,
uint64_t row_id,
const struct TALER_MerchantPublicKeyP *merchant_pub,
const struct TALER_CoinSpendPublicKeyP *coin_pub,
const struct TALER_Amount *amount_with_fee,
const struct TALER_Amount *deposit_fee,
const struct GNUNET_HashCode *h_contract_terms,
struct GNUNET_TIME_Absolute wire_deadline,
const json_t *wire)
{
au->merchant_pub = *merchant_pub;
if (GNUNET_OK !=
TALER_amount_subtract (&au->total_amount,
amount_with_fee,
deposit_fee))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Fatally malformed record at row %llu\n",
(unsigned long long) row_id);
return GNUNET_SYSERR;
}
au->row_id = row_id;
GNUNET_assert (NULL == au->wire);
au->wire = json_incref ((json_t *) wire);
TALER_JSON_hash (au->wire,
&au->h_wire);
GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_NONCE,
&au->wtid,
sizeof (au->wtid));
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Starting aggregation under H(WTID)=%s\n",
TALER_B2S (&au->wtid));
au->wp = find_plugin (extract_type (au->wire));
if (NULL == au->wp)
return GNUNET_SYSERR;
/* make sure we have current fees */
au->execution_time = GNUNET_TIME_absolute_get ();
(void) GNUNET_TIME_round_abs (&au->execution_time);
if (GNUNET_OK !=
update_fees (au->wp,
au->execution_time,
au->session))
return GNUNET_SYSERR;
au->wire_fee = au->wp->af->wire_fee;
if (GNUNET_OK !=
db_plugin->insert_aggregation_tracking (db_plugin->cls,
au->session,
&au->wtid,
row_id))
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
if (GNUNET_OK !=
db_plugin->mark_deposit_done (db_plugin->cls,
au->session,
row_id))
{
GNUNET_break (0);
au->failed = GNUNET_YES;
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* Function called with details about another deposit we
* can aggregate into an existing aggregation unit.
*
* @param cls NULL
* @param row_id identifies database entry
* @param merchant_pub public key of the merchant
* @param coin_pub public key of the coin
* @param amount_with_fee amount that was deposited including fee
* @param deposit_fee amount the exchange gets to keep as transaction fees
* @param h_contract_terms hash of the proposal data known to merchant and customer
* @param wire_deadline by which the merchant adviced that he would like the
* wire transfer to be executed
* @param wire wire details for the merchant
* @return #GNUNET_OK to continue to iterate, #GNUNET_SYSERR to stop
*/
static int
aggregate_cb (void *cls,
uint64_t row_id,
const struct TALER_MerchantPublicKeyP *merchant_pub,
const struct TALER_CoinSpendPublicKeyP *coin_pub,
const struct TALER_Amount *amount_with_fee,
const struct TALER_Amount *deposit_fee,
const struct GNUNET_HashCode *h_contract_terms,
struct GNUNET_TIME_Absolute wire_deadline,
const json_t *wire)
{
struct TALER_Amount delta;
GNUNET_break (0 ==
memcmp (&au->merchant_pub,
merchant_pub,
sizeof (struct TALER_MerchantPublicKeyP)));
/* compute contribution of this coin after fees */
if (GNUNET_OK !=
TALER_amount_subtract (&delta,
amount_with_fee,
deposit_fee))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Fatally malformed record at %llu\n",
(unsigned long long) row_id);
return GNUNET_SYSERR;
}
/* add to total */
if (GNUNET_OK !=
TALER_amount_add (&au->total_amount,
&au->total_amount,
&delta))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Overflow or currency incompatibility during aggregation at %llu\n",
(unsigned long long) row_id);
/* Skip this one, but keep going! */
return GNUNET_OK;
}
if (au->rows_offset >= aggregation_limit)
{
/* Bug: we asked for at most #aggregation_limit results! */
GNUNET_break (0);
/* Skip this one, but keep going. */
return GNUNET_OK;
}
if (NULL == au->additional_rows)
au->additional_rows = GNUNET_new_array (aggregation_limit,
unsigned long long);
/* "append" to our list of rows */
au->additional_rows[au->rows_offset++] = row_id;
/* insert into aggregation tracking table */
if (GNUNET_OK !=
db_plugin->insert_aggregation_tracking (db_plugin->cls,
au->session,
&au->wtid,
row_id))
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
if (GNUNET_OK !=
db_plugin->mark_deposit_done (db_plugin->cls,
au->session,
row_id))
{
GNUNET_break (0);
au->failed = GNUNET_YES;
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* Function to be called with the prepared transfer data
* when running an aggregation on a merchant.
*
* @param cls closure with the `struct AggregationUnit`
* @param buf transaction data to persist, NULL on error
* @param buf_size number of bytes in @a buf, 0 on error
*/
static void
prepare_cb (void *cls,
const char *buf,
size_t buf_size);
/**
* Main work function that finds and triggers transfers for reserves
* closures.
*
* @param cls closure
*/
static void
run_reserve_closures (void *cls);
/**
* Main work function that queries the DB and aggregates transactions
* into larger wire transfers.
*
* @param cls NULL
*/
static void
run_aggregation (void *cls);
/**
* Function to be called with the prepared transfer data
* when closing a reserve.
*
* @param cls closure with a `struct CloseTransferContext`
* @param buf transaction data to persist, NULL on error
* @param buf_size number of bytes in @a buf, 0 on error
*/
static void
prepare_close_cb (void *cls,
const char *buf,
size_t buf_size)
{
GNUNET_assert (cls == ctc);
ctc->ph = NULL;
if (NULL == buf)
{
GNUNET_break (0); /* why? how to best recover? */
db_plugin->rollback (db_plugin->cls,
ctc->session);
/* start again */
GNUNET_free (ctc->type);
GNUNET_free (ctc);
ctc = NULL;
task = GNUNET_SCHEDULER_add_now (&run_aggregation,
NULL);
return;
}
/* Commit our intention to execute the wire transfer! */
if (GNUNET_OK !=
db_plugin->wire_prepare_data_insert (db_plugin->cls,
ctc->session,
ctc->type,
buf,
buf_size))
{
GNUNET_break (0); /* why? how to best recover? */
db_plugin->rollback (db_plugin->cls,
ctc->session);
/* start again */
task = GNUNET_SCHEDULER_add_now (&run_aggregation,
NULL);
GNUNET_free (ctc->type);
GNUNET_free (ctc);
ctc = NULL;
return;
}
/* finally commit */
if (GNUNET_OK !=
db_plugin->commit (db_plugin->cls,
ctc->session))
{
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Failed to commit database transaction!\n");
}
GNUNET_free (ctc->type);
GNUNET_free (ctc);
ctc = NULL;
task = GNUNET_SCHEDULER_add_now (&run_aggregation,
NULL);
}
/**
* Function called with details about expired reserves.
* We trigger the reserve closure by inserting the respective
* closing record and prewire instructions into the respective
* tables.
*
* @param cls a `struct TALER_EXCHANGEDB_Session *`
* @param reserve_pub public key of the reserve
* @param left amount left in the reserve
* @param account_details information about the reserve's bank account
* @param expiration_date when did the reserve expire
* @return #GNUNET_OK to continue to iterate, #GNUNET_SYSERR to stop
*/
static int
expired_reserve_cb (void *cls,
const struct TALER_ReservePublicKeyP *reserve_pub,
const struct TALER_Amount *left,
const json_t *account_details,
struct GNUNET_TIME_Absolute expiration_date)
{
struct TALER_EXCHANGEDB_Session *session = cls;
struct GNUNET_TIME_Absolute now;
struct TALER_WireTransferIdentifierRawP wtid;
struct TALER_Amount amount_without_fee;
const struct TALER_Amount *closing_fee;
int ret;
int iret;
const char *type;
struct WirePlugin *wp;
GNUNET_assert (NULL == ctc);
now = GNUNET_TIME_absolute_get ();
/* lookup wire plugin */
type = extract_type (account_details);
if (NULL == type)
{
GNUNET_break (0);
db_plugin->rollback (db_plugin->cls,
session);
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
return GNUNET_SYSERR;
}
wp = find_plugin (type);
if (NULL == wp)
{
GNUNET_break (0);
db_plugin->rollback (db_plugin->cls,
session);
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
return GNUNET_SYSERR;
}
/* lookup `closing_fee` */
if (GNUNET_OK !=
update_fees (wp,
now,
session))
{
GNUNET_break (0);
db_plugin->rollback (db_plugin->cls,
session);
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
return GNUNET_SYSERR;
}
closing_fee = &wp->af->closing_fee;
/* calculate transfer amount */
ret = TALER_amount_subtract (&amount_without_fee,
left,
closing_fee);
if ( (GNUNET_SYSERR == ret) ||
(GNUNET_NO == ret) )
{
/* Closing fee higher than remaining balance, close
without wire transfer. */
closing_fee = left;
TALER_amount_get_zero (left->currency,
&amount_without_fee);
}
/* NOTE: sizeof (*reserve_pub) == sizeof (wtid) right now, but to
be future-compatible, we use the memset + min construction */
memset (&wtid,
0,
sizeof (wtid));
memcpy (&wtid,
reserve_pub,
GNUNET_MIN (sizeof (wtid),
sizeof (*reserve_pub)));
iret = db_plugin->insert_reserve_closed (db_plugin->cls,
session,
reserve_pub,
now,
account_details,
&wtid,
left,
closing_fee);
if ( (GNUNET_OK == ret) &&
(GNUNET_OK == iret) )
{
/* success, perform wire transfer */
if (GNUNET_SYSERR ==
wp->wire_plugin->amount_round (wp->wire_plugin->cls,
&amount_without_fee))
{
GNUNET_break (0);
db_plugin->rollback (db_plugin->cls,
session);
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
return GNUNET_SYSERR;
}
ctc = GNUNET_new (struct CloseTransferContext);
ctc->session = session;
ctc->type = GNUNET_strdup (type);
ctc->ph
= wp->wire_plugin->prepare_wire_transfer (wp->wire_plugin->cls,
au->wire,
&amount_without_fee,
exchange_base_url,
&wtid,
&prepare_close_cb,
ctc);
if (NULL == ctc->ph)
{
GNUNET_break (0);
db_plugin->rollback (db_plugin->cls,
session);
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
GNUNET_free (ctc->type);
GNUNET_free (ctc);
ctc = NULL;
}
return GNUNET_SYSERR;
}
/* Check for hard failure */
if (GNUNET_SYSERR == iret)
{
GNUNET_break (0);
db_plugin->rollback (db_plugin->cls,
session);
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
return GNUNET_SYSERR;
}
/* Reserve balance was almost zero; just commit */
if (GNUNET_OK !=
db_plugin->commit (db_plugin->cls,
session))
{
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Failed to commit database transaction!\n");
}
task = GNUNET_SCHEDULER_add_now (&run_reserve_closures,
NULL);
return GNUNET_SYSERR;
}
/**
* Main work function that finds and triggers transfers for reserves
* closures.
*
* @param cls closure
*/
static void
run_reserve_closures (void *cls)
{
struct TALER_EXCHANGEDB_Session *session;
int ret;
const struct GNUNET_SCHEDULER_TaskContext *tc;
task = NULL;
reserves_idle = GNUNET_NO;
tc = GNUNET_SCHEDULER_get_task_context ();
if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
return;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Checking for reserves to close\n");
if (NULL == (session = db_plugin->get_session (db_plugin->cls)))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Failed to obtain database session!\n");
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
return;
}
if (GNUNET_OK !=
db_plugin->start (db_plugin->cls,
session))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Failed to start database transaction!\n");
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
return;
}
ret = db_plugin->get_expired_reserves (db_plugin->cls,
session,
GNUNET_TIME_absolute_get (),
&expired_reserve_cb,
session);
if (GNUNET_SYSERR == ret)
{
GNUNET_break (0);
db_plugin->rollback (db_plugin->cls,
session);
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
return;
}
if (GNUNET_NO == ret)
{
reserves_idle = GNUNET_YES;
db_plugin->rollback (db_plugin->cls,
session);
task = GNUNET_SCHEDULER_add_now (&run_aggregation,
NULL);
return;
}
}
/**
* Main work function that queries the DB and aggregates transactions
* into larger wire transfers.
*
* @param cls NULL
*/
static void
run_aggregation (void *cls)
{
static int swap;
struct TALER_EXCHANGEDB_Session *session;
unsigned int i;
int ret;
const struct GNUNET_SCHEDULER_TaskContext *tc;
task = NULL;
tc = GNUNET_SCHEDULER_get_task_context ();
if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
return;
if (0 == (++swap % 2))
{
task = GNUNET_SCHEDULER_add_now (&run_reserve_closures,
NULL);
return;
}
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Checking for ready deposits to aggregate\n");
if (NULL == (session = db_plugin->get_session (db_plugin->cls)))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Failed to obtain database session!\n");
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
return;
}
if (GNUNET_OK !=
db_plugin->start_deferred_wire_out (db_plugin->cls,
session))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Failed to start database transaction!\n");
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
return;
}
au = GNUNET_new (struct AggregationUnit);
au->session = session;
ret = db_plugin->get_ready_deposit (db_plugin->cls,
session,
&deposit_cb,
au);
if (0 >= ret)
{
if (NULL != au->wire)
json_decref (au->wire);
GNUNET_free (au);
au = NULL;
db_plugin->rollback (db_plugin->cls,
session);
if (GNUNET_SYSERR == ret)
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Failed to execute deposit iteration!\n");
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
return;
}
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"No more ready deposits, going to sleep\n");
if (GNUNET_YES == test_mode)
{
/* in test mode, shutdown if we end up being idle */
GNUNET_SCHEDULER_shutdown ();
}
else
{
/* nothing to do, sleep for a minute and try again */
if (GNUNET_NO == reserves_idle)
task = GNUNET_SCHEDULER_add_now (&run_reserve_closures,
NULL);
else
task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
&run_aggregation,
NULL);
}
return;
}
/* Now try to find other deposits to aggregate */
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Found ready deposit for %s, aggregating\n",
TALER_B2S (&au->merchant_pub));
ret = db_plugin->iterate_matching_deposits (db_plugin->cls,
session,
&au->h_wire,
&au->merchant_pub,
&aggregate_cb,
au,
aggregation_limit);
if ( (GNUNET_SYSERR == ret) ||
(GNUNET_YES == au->failed) )
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Failed to execute deposit iteration!\n");
GNUNET_free_non_null (au->additional_rows);
json_decref (au->wire);
GNUNET_free (au);
au = NULL;
db_plugin->rollback (db_plugin->cls,
session);
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
return;
}
/* Subtract wire transfer fee and round to the unit supported by the
wire transfer method; Check if after rounding down, we still have
an amount to transfer, and if not mark as 'tiny'. */
if ( (GNUNET_OK !=
TALER_amount_subtract (&au->final_amount,
&au->total_amount,
&au->wire_fee)) ||
(GNUNET_SYSERR ==
au->wp->wire_plugin->amount_round (au->wp->wire_plugin->cls,
&au->final_amount)) ||
( (0 == au->final_amount.value) &&
(0 == au->final_amount.fraction) ) )
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Aggregate value too low for transfer\n");
/* Rollback ongoing transaction, as we will not use the respective
WTID and thus need to remove the tracking data */
db_plugin->rollback (db_plugin->cls,
session);
/* Start another transaction to mark all* of the selected deposits
*as minor! */
if (GNUNET_OK !=
db_plugin->start (db_plugin->cls,
session))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Failed to start database transaction!\n");
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
GNUNET_free_non_null (au->additional_rows);
if (NULL != au->wire)
json_decref (au->wire);
GNUNET_free (au);
au = NULL;
return;
}
/* Mark transactions by row_id as minor */
ret = GNUNET_OK;
if (GNUNET_OK !=
db_plugin->mark_deposit_tiny (db_plugin->cls,
session,
au->row_id))
ret = GNUNET_SYSERR;
else
for (i=0;irows_offset;i++)
if (GNUNET_OK !=
db_plugin->mark_deposit_tiny (db_plugin->cls,
session,
au->additional_rows[i]))
ret = GNUNET_SYSERR;
/* commit */
if (GNUNET_OK !=
db_plugin->commit (db_plugin->cls,
session))
{
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Failed to commit database transaction!\n");
}
GNUNET_free_non_null (au->additional_rows);
if (NULL != au->wire)
json_decref (au->wire);
GNUNET_free (au);
au = NULL;
/* start again */
task = GNUNET_SCHEDULER_add_now (&run_aggregation,
NULL);
return;
}
{
char *amount_s;
amount_s = TALER_amount_to_string (&au->final_amount);
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Preparing wire transfer of %s to %s\n",
amount_s,
TALER_B2S (&au->merchant_pub));
GNUNET_free (amount_s);
}
au->ph = au->wp->wire_plugin->prepare_wire_transfer (au->wp->wire_plugin->cls,
au->wire,
&au->final_amount,
exchange_base_url,
&au->wtid,
&prepare_cb,
au);
if (NULL == au->ph)
{
GNUNET_break (0); /* why? how to best recover? */
db_plugin->rollback (db_plugin->cls,
session);
GNUNET_free_non_null (au->additional_rows);
if (NULL != au->wire)
json_decref (au->wire);
GNUNET_free (au);
au = NULL;
/* start again */
task = GNUNET_SCHEDULER_add_now (&run_aggregation,
NULL);
return;
}
/* otherwise we continue with #prepare_cb(), see below */
}
/**
* Execute the wire transfers that we have committed to
* do.
*
* @param cls pointer to an `int` which we will return from main()
*/
static void
run_transfers (void *cls);
/**
* Function to be called with the prepared transfer data.
*
* @param cls NULL
* @param buf transaction data to persist, NULL on error
* @param buf_size number of bytes in @a buf, 0 on error
*/
static void
prepare_cb (void *cls,
const char *buf,
size_t buf_size)
{
struct TALER_EXCHANGEDB_Session *session = au->session;
GNUNET_free_non_null (au->additional_rows);
if (NULL == buf)
{
GNUNET_break (0); /* why? how to best recover? */
db_plugin->rollback (db_plugin->cls,
session);
/* start again */
task = GNUNET_SCHEDULER_add_now (&run_aggregation,
NULL);
if (NULL != au->wire)
{
json_decref (au->wire);
au->wire = NULL;
}
GNUNET_free (au);
au = NULL;
return;
}
/* Commit our intention to execute the wire transfer! */
if (GNUNET_OK !=
db_plugin->wire_prepare_data_insert (db_plugin->cls,
session,
au->wp->type,
buf,
buf_size))
{
GNUNET_break (0); /* why? how to best recover? */
db_plugin->rollback (db_plugin->cls,
session);
/* start again */
task = GNUNET_SCHEDULER_add_now (&run_aggregation,
NULL);
if (NULL != au->wire)
{
json_decref (au->wire);
au->wire = NULL;
}
GNUNET_free (au);
au = NULL;
return;
}
/* Commit the WTID data to 'wire_out' to finally satisfy aggregation
table constraints */
if (GNUNET_OK !=
db_plugin->store_wire_transfer_out (db_plugin->cls,
session,
au->execution_time,
&au->wtid,
au->wire,
&au->final_amount))
{
GNUNET_break (0); /* why? how to best recover? */
db_plugin->rollback (db_plugin->cls,
session);
/* start again */
task = GNUNET_SCHEDULER_add_now (&run_aggregation,
NULL);
if (NULL != au->wire)
{
json_decref (au->wire);
au->wire = NULL;
}
GNUNET_free (au);
au = NULL;
return;
}
if (NULL != au->wire)
{
json_decref (au->wire);
au->wire = NULL;
}
GNUNET_free (au);
au = NULL;
/* Now we can finally commit the overall transaction, as we are
again consistent if all of this passes. */
if (GNUNET_OK !=
db_plugin->commit (db_plugin->cls,
session))
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Failed to commit database transaction!\n");
/* try again */
task = GNUNET_SCHEDULER_add_now (&run_aggregation,
NULL);
return;
}
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Preparation complete, switching to transfer mode\n");
/* run alternative task: actually do wire transfer! */
task = GNUNET_SCHEDULER_add_now (&run_transfers,
NULL);
}
/**
* Function called with the result from the execute step.
*
* @param cls NULL
* @param success #GNUNET_OK on success, #GNUNET_SYSERR on failure
* @param serial_id unique ID of the wire transfer in the bank's records; UINT64_MAX on error
* @param emsg NULL on success, otherwise an error message
*/
static void
wire_confirm_cb (void *cls,
int success,
uint64_t serial_id,
const char *emsg)
{
struct TALER_EXCHANGEDB_Session *session = wpd->session;
wpd->eh = NULL;
if (GNUNET_SYSERR == success)
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Wire transaction failed: %s\n",
emsg);
db_plugin->rollback (db_plugin->cls,
session);
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
GNUNET_free (wpd);
wpd = NULL;
return;
}
if (GNUNET_OK !=
db_plugin->wire_prepare_data_mark_finished (db_plugin->cls,
session,
wpd->row_id))
{
GNUNET_break (0); /* why!? */
db_plugin->rollback (db_plugin->cls,
session);
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
GNUNET_free (wpd);
wpd = NULL;
return;
}
GNUNET_free (wpd);
wpd = NULL;
if (GNUNET_OK !=
db_plugin->commit (db_plugin->cls,
session))
{
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Failed to commit database transaction!\n");
/* try again */
task = GNUNET_SCHEDULER_add_now (&run_aggregation,
NULL);
return;
}
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Wire transfer complete\n");
/* continue with #run_transfers(), just to guard
against the unlikely case that there are more. */
task = GNUNET_SCHEDULER_add_now (&run_transfers,
NULL);
}
/**
* Callback with data about a prepared transaction.
*
* @param cls NULL
* @param rowid row identifier used to mark prepared transaction as done
* @param wire_method wire method the preparation was done for
* @param buf transaction data that was persisted, NULL on error
* @param buf_size number of bytes in @a buf, 0 on error
*/
static void
wire_prepare_cb (void *cls,
uint64_t rowid,
const char *wire_method,
const char *buf,
size_t buf_size)
{
wpd->row_id = rowid;
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Starting wire transfer %llu\n",
(unsigned long long) rowid);
wpd->wp = find_plugin (wire_method);
wpd->eh = wpd->wp->wire_plugin->execute_wire_transfer (wpd->wp->wire_plugin->cls,
buf,
buf_size,
&wire_confirm_cb,
NULL);
if (NULL == wpd->eh)
{
GNUNET_break (0); /* why? how to best recover? */
db_plugin->rollback (db_plugin->cls,
wpd->session);
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
GNUNET_free (wpd);
wpd = NULL;
return;
}
}
/**
* Execute the wire transfers that we have committed to
* do.
*
* @param cls NULL
*/
static void
run_transfers (void *cls)
{
int ret;
struct TALER_EXCHANGEDB_Session *session;
const struct GNUNET_SCHEDULER_TaskContext *tc;
task = NULL;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Checking for pending wire transfers\n");
tc = GNUNET_SCHEDULER_get_task_context ();
if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
return;
if (NULL == (session = db_plugin->get_session (db_plugin->cls)))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Failed to obtain database session!\n");
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
return;
}
if (GNUNET_OK !=
db_plugin->start (db_plugin->cls,
session))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"Failed to start database transaction!\n");
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
return;
}
wpd = GNUNET_new (struct WirePrepareData);
wpd->session = session;
ret = db_plugin->wire_prepare_data_get (db_plugin->cls,
session,
&wire_prepare_cb,
NULL);
if (GNUNET_SYSERR == ret)
{
GNUNET_break (0); /* why? how to best recover? */
db_plugin->rollback (db_plugin->cls,
session);
global_ret = GNUNET_SYSERR;
GNUNET_SCHEDULER_shutdown ();
GNUNET_free (wpd);
wpd = NULL;
return;
}
if (GNUNET_NO == ret)
{
/* no more prepared wire transfers, go back to aggregation! */
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"No more pending wire transfers, starting aggregation\n");
db_plugin->rollback (db_plugin->cls,
session);
task = GNUNET_SCHEDULER_add_now (&run_aggregation,
NULL);
GNUNET_free (wpd);
wpd = NULL;
return;
}
/* otherwise, continues in #wire_prepare_cb() */
}
/**
* First task.
*
* @param cls closure, NULL
* @param args remaining command-line arguments
* @param cfgfile name of the configuration file used (for saving, can be NULL!)
* @param c configuration
*/
static void
run (void *cls,
char *const *args,
const char *cfgfile,
const struct GNUNET_CONFIGURATION_Handle *c)
{
if (GNUNET_OK !=
GNUNET_CONFIGURATION_get_value_string (c,
"exchange",
"BASE_URL",
&exchange_base_url))
{
GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
"exchange",
"BASE_URL");
global_ret = 1;
return;
}
cfg = GNUNET_CONFIGURATION_dup (c);
if (GNUNET_OK != exchange_serve_process_config ())
{
GNUNET_CONFIGURATION_destroy (cfg);
cfg = NULL;
global_ret = 1;
return;
}
task = GNUNET_SCHEDULER_add_now (&run_transfers,
NULL);
GNUNET_SCHEDULER_add_shutdown (&shutdown_task,
cls);
}
/**
* The main function of the taler-exchange-aggregator.
*
* @param argc number of arguments from the command line
* @param argv command line arguments
* @return 0 ok, 1 on error
*/
int
main (int argc,
char *const *argv)
{
struct GNUNET_GETOPT_CommandLineOption options[] = {
GNUNET_GETOPT_option_flag ('t',
"test",
"run in test mode and exit when idle",
&test_mode),
GNUNET_GETOPT_option_version (VERSION "-" VCS_VERSION),
GNUNET_GETOPT_OPTION_END
};
if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv,
&argc, &argv))
return 2;
if (GNUNET_OK !=
GNUNET_PROGRAM_run (argc, argv,
"taler-exchange-aggregator",
gettext_noop ("background process that aggregates and executes wire transfers to merchants"),
options,
&run, NULL))
{
GNUNET_free ((void*) argv);
return 1;
}
GNUNET_free ((void*) argv);
return global_ret;
}
/* end of taler-exchange-aggregator.c */