/*
This file is part of TALER
Copyright (C) 2015-2020 Taler Systems SA
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_wire.c
* @brief Handle /wire requests
* @author Christian Grothoff
*/
#include "platform.h"
#include
#include "taler-exchange-httpd_responses.h"
#include "taler-exchange-httpd_wire.h"
#include "taler_json_lib.h"
#include "taler_mhd_lib.h"
#include
/**
* Thread-local. Contains a pointer to `struct WireStateHandle` or NULL.
* Stores the per-thread latest generation of our wire response.
*/
static pthread_key_t wire_state;
/**
* Counter incremented whenever we have a reason to re-build the #wire_state
* because something external changed (in another thread). The counter is
* manipulated using an atomic update, and thus to ensure that threads notice
* when it changes, the variable MUST be volatile. See #get_wire_state()
* and #TEH_wire_update_state() for uses of this variable.
*/
static volatile uint64_t wire_generation;
/**
* State we keep per thread to cache the /wire response.
*/
struct WireStateHandle
{
/**
* Cached JSON for /wire response.
*/
json_t *wire_reply;
/**
* For which (global) wire_generation was this data structure created?
* Used to check when we are outdated and need to be re-generated.
*/
uint64_t wire_generation;
};
/**
* Free memory associated with @a wsh
*
* @param[in] wsh wire state to destroy
*/
static void
destroy_wire_state (struct WireStateHandle *wsh)
{
json_decref (wsh->wire_reply);
GNUNET_free (wsh);
}
/**
* Free memory associated with wire state. Signature
* suitable for pthread_key_create().
*
* @param[in] cls the `struct WireStateHandle` to destroy
*/static void
destroy_wire_state_cb (void *cls)
{
struct WireStateHandle *wsh = cls;
destroy_wire_state (wsh);
}
/**
* Initialize WIRE submodule.
*
* @return #GNUNET_OK on success
*/
int
TEH_WIRE_init ()
{
if (0 !=
pthread_key_create (&wire_state,
&destroy_wire_state_cb))
return GNUNET_SYSERR;
return GNUNET_OK;
}
/**
* Fully clean up our state.
*/
void
TEH_WIRE_done ()
{
GNUNET_assert (0 ==
pthread_key_delete (wire_state));
}
/**
* Add information about a wire account to @a cls.
*
* @param cls a `json_t *` object to expand with wire account details
* @param payto_uri the exchange bank account URI to add
* @param master_sig master key signature affirming that this is a bank
* account of the exchange (of purpose #TALER_SIGNATURE_MASTER_WIRE_DETAILS)
*/
static void
add_wire_account (void *cls,
const char *payto_uri,
const struct TALER_MasterSignatureP *master_sig)
{
json_t *a = cls;
if (0 !=
json_array_append_new (
a,
json_pack ("{s:s, s:o}",
"payto_uri",
payto_uri,
"master_sig",
GNUNET_JSON_from_data_auto (master_sig))))
{
GNUNET_break (0); /* out of memory!? */
return;
}
}
/**
* Add information about a wire account to @a cls.
*
* @param cls a `json_t *` array to expand with wire account details
* @param wire_fee the wire fee we charge
* @param closing_fee the closing fee we charge
* @param start_date from when are these fees valid (start date)
* @param end_date until when are these fees valid (end date, exclusive)
* @param master_sig master key signature affirming that this is the correct
* fee (of purpose #TALER_SIGNATURE_MASTER_WIRE_FEES)
*/
static void
add_wire_fee (void *cls,
const struct TALER_Amount *wire_fee,
const struct TALER_Amount *closing_fee,
struct GNUNET_TIME_Absolute start_date,
struct GNUNET_TIME_Absolute end_date,
const struct TALER_MasterSignatureP *master_sig)
{
json_t *a = cls;
if (0 !=
json_array_append_new (
a,
json_pack ("{s:o, s:o, s:o, s:o, s:o}",
"wire_fee",
TALER_JSON_from_amount (wire_fee),
"closing_fee",
TALER_JSON_from_amount (closing_fee),
"start_date",
GNUNET_JSON_from_time_abs (start_date),
"end_date",
GNUNET_JSON_from_time_abs (end_date),
"sig",
GNUNET_JSON_from_data_auto (master_sig))))
{
GNUNET_break (0); /* out of memory!? */
return;
}
}
/**
* Create the /wire response from our database state.
*
* @return NULL on error
*/
static struct WireStateHandle *
build_wire_state (void)
{
json_t *wire_accounts_array;
json_t *wire_fee_object;
json_t *wire_reply;
uint64_t wg = wire_generation; /* must be obtained FIRST */
enum GNUNET_DB_QueryStatus qs;
wire_accounts_array = json_array ();
GNUNET_assert (NULL != wire_accounts_array);
qs = TEH_plugin->get_wire_accounts (TEH_plugin->cls,
&add_wire_account,
wire_accounts_array);
if (0 > qs)
{
GNUNET_break (0);
json_decref (wire_accounts_array);
return NULL;
}
if (0 == json_array_size (wire_accounts_array))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"No bank accounts for the exchange configured. Administrator must `enable-account` with taler-exchange-offline!\n");
json_decref (wire_accounts_array);
return NULL;
}
wire_fee_object = json_object ();
GNUNET_assert (NULL != wire_fee_object);
{
json_t *account;
size_t index;
json_array_foreach (wire_accounts_array, index, account) {
char *wire_method;
const char *payto_uri = json_string_value (json_object_get (account,
"payto_uri"));
GNUNET_assert (NULL != payto_uri);
wire_method = TALER_payto_get_method (payto_uri);
if (NULL == wire_method)
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"payto:// URI `%s' stored in our database is malformed\n",
payto_uri);
json_decref (wire_accounts_array);
json_decref (wire_fee_object);
return NULL;
}
if (NULL == json_object_get (wire_fee_object,
wire_method))
{
json_t *a = json_array ();
GNUNET_assert (NULL != a);
qs = TEH_plugin->get_wire_fees (TEH_plugin->cls,
wire_method,
&add_wire_fee,
a);
if (0 > qs)
{
GNUNET_break (0);
json_decref (a);
json_decref (wire_fee_object);
json_decref (wire_accounts_array);
GNUNET_free (wire_method);
return NULL;
}
if (0 == json_array_size (a))
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"No wire fees for `%s' configured. Administrator must set `wire-fee` with taler-exchange-offline!\n",
wire_method);
json_decref (wire_accounts_array);
json_decref (wire_fee_object);
GNUNET_free (wire_method);
return NULL;
}
GNUNET_assert (0 ==
json_object_set_new (wire_fee_object,
wire_method,
a));
}
GNUNET_free (wire_method);
}
}
wire_reply = json_pack (
"{s:O, s:O, s:o}",
"accounts", wire_accounts_array,
"fees", wire_fee_object,
"master_public_key",
GNUNET_JSON_from_data_auto (&TEH_master_public_key));
GNUNET_assert (NULL != wire_reply);
{
struct WireStateHandle *wsh;
wsh = GNUNET_new (struct WireStateHandle);
wsh->wire_reply = wire_reply;
wsh->wire_generation = wg;
return wsh;
}
}
void
TEH_wire_update_state (void)
{
__sync_fetch_and_add (&wire_generation,
1);
}
/**
* Return the current key state for this thread. Possibly
* re-builds the key state if we have reason to believe
* that something changed.
*
* @return NULL on error
*/
struct WireStateHandle *
get_wire_state (void)
{
struct WireStateHandle *old_wsh;
struct WireStateHandle *wsh;
old_wsh = pthread_getspecific (wire_state);
if ( (NULL == old_wsh) ||
(old_wsh->wire_generation < wire_generation) )
{
wsh = build_wire_state ();
if (NULL == wsh)
return NULL;
if (0 != pthread_setspecific (wire_state,
wsh))
{
GNUNET_break (0);
destroy_wire_state (wsh);
return NULL;
}
if (NULL != old_wsh)
destroy_wire_state (old_wsh);
return wsh;
}
return old_wsh;
}
/**
* Handle a "/wire" request.
*
* @param rh context of the handler
* @param connection the MHD connection to handle
* @param args array of additional options (must be empty for this function)
* @return MHD result code
*/
MHD_RESULT
TEH_handler_wire (const struct TEH_RequestHandler *rh,
struct MHD_Connection *connection,
const char *const args[])
{
struct WireStateHandle *wsh;
(void) rh;
(void) args;
wsh = get_wire_state ();
if (NULL == wsh)
return TALER_MHD_reply_with_error (connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_EXCHANGE_GENERIC_BAD_CONFIGURATION,
NULL);
return TALER_MHD_reply_json (connection,
json_incref (wsh->wire_reply),
MHD_HTTP_OK);
}
/* end of taler-exchange-httpd_wire.c */