/*
This file is part of TALER
Copyright (C) 2015-2022 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_dbevents.h"
#include "taler-exchange-httpd_responses.h"
#include "taler-exchange-httpd_keys.h"
#include "taler-exchange-httpd_wire.h"
#include "taler_json_lib.h"
#include "taler_mhd_lib.h"
#include
/**
* Information we track about wire fees.
*/
struct WireFeeSet
{
/**
* Kept in a DLL.
*/
struct WireFeeSet *next;
/**
* Kept in a DLL.
*/
struct WireFeeSet *prev;
/**
* Actual fees.
*/
struct TALER_WireFeeSet fees;
/**
* Start date of fee validity (inclusive).
*/
struct GNUNET_TIME_Timestamp start_date;
/**
* End date of fee validity (exclusive).
*/
struct GNUNET_TIME_Timestamp end_date;
/**
* Wire method the fees apply to.
*/
char *method;
};
/**
* State we keep per thread to cache the /wire response.
*/
struct WireStateHandle
{
/**
* Cached reply for /wire response.
*/
struct MHD_Response *wire_reply;
/**
* ETag for this response (if any).
*/
char *etag;
/**
* head of DLL of wire fees.
*/
struct WireFeeSet *wfs_head;
/**
* Tail of DLL of wire fees.
*/
struct WireFeeSet *wfs_tail;
/**
* Earliest timestamp of all the wire methods when we have no more fees.
*/
struct GNUNET_TIME_Absolute cache_expiration;
/**
* @e cache_expiration time, formatted.
*/
char dat[128];
/**
* 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* Used to check when we are outdated and need to be re-generated.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;
/**
* HTTP status to return with this response.
*/
unsigned int http_status;
};
/**
* Stores the latest generation of our wire response.
*/
static struct WireStateHandle *wire_state;
/**
* Handler listening for wire updates by other exchange
* services.
*/
static struct GNUNET_DB_EventHandler *wire_eh;
/**
* Counter incremented whenever we have a reason to re-build the #wire_state
* because something external changed.
*/
static 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)
{
struct WireFeeSet *wfs;
while (NULL != (wfs = wsh->wfs_head))
{
GNUNET_CONTAINER_DLL_remove (wsh->wfs_head,
wsh->wfs_tail,
wfs);
GNUNET_free (wfs->method);
GNUNET_free (wfs);
}
MHD_destroy_response (wsh->wire_reply);
GNUNET_free (wsh->etag);
GNUNET_free (wsh);
}
/**
* Function called whenever another exchange process has updated
* the wire data in the database.
*
* @param cls NULL
* @param extra unused
* @param extra_size number of bytes in @a extra unused
*/
static void
wire_update_event_cb (void *cls,
const void *extra,
size_t extra_size)
{
(void) cls;
(void) extra;
(void) extra_size;
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Received /wire update event\n");
TEH_check_invariants ();
wire_generation++;
}
enum GNUNET_GenericReturnValue
TEH_wire_init ()
{
struct GNUNET_DB_EventHeaderP es = {
.size = htons (sizeof (es)),
.type = htons (TALER_DBEVENT_EXCHANGE_KEYS_UPDATED),
};
wire_eh = TEH_plugin->event_listen (TEH_plugin->cls,
GNUNET_TIME_UNIT_FOREVER_REL,
&es,
&wire_update_event_cb,
NULL);
if (NULL == wire_eh)
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
void
TEH_wire_done ()
{
if (NULL != wire_state)
{
destroy_wire_state (wire_state);
wire_state = NULL;
}
if (NULL != wire_eh)
{
TEH_plugin->event_listen_cancel (TEH_plugin->cls,
wire_eh);
wire_eh = NULL;
}
}
/**
* 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,
GNUNET_JSON_PACK (
GNUNET_JSON_pack_string ("payto_uri",
payto_uri),
GNUNET_JSON_pack_data_auto ("master_sig",
master_sig))))
{
GNUNET_break (0); /* out of memory!? */
return;
}
}
/**
* Closure for #add_wire_fee().
*/
struct AddContext
{
/**
* Wire method the fees are for.
*/
char *wire_method;
/**
* Wire state we are building.
*/
struct WireStateHandle *wsh;
/**
* Array to append the fee to.
*/
json_t *a;
/**
* Context we hash "everything" we add into. This is used
* to compute the etag. Technically, we only hash the
* master_sigs, as they imply the rest.
*/
struct GNUNET_HashContext *hc;
/**
* Set to the maximum end-date seen.
*/
struct GNUNET_TIME_Absolute max_seen;
};
/**
* Add information about a wire account to @a cls.
*
* @param cls a `struct AddContext`
* @param fees the wire fees 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_WireFeeSet *fees,
struct GNUNET_TIME_Timestamp start_date,
struct GNUNET_TIME_Timestamp end_date,
const struct TALER_MasterSignatureP *master_sig)
{
struct AddContext *ac = cls;
struct WireFeeSet *wfs;
GNUNET_CRYPTO_hash_context_read (ac->hc,
master_sig,
sizeof (*master_sig));
ac->max_seen = GNUNET_TIME_absolute_max (ac->max_seen,
end_date.abs_time);
wfs = GNUNET_new (struct WireFeeSet);
wfs->start_date = start_date;
wfs->end_date = end_date;
wfs->fees = *fees;
wfs->method = GNUNET_strdup (ac->wire_method);
GNUNET_CONTAINER_DLL_insert (ac->wsh->wfs_head,
ac->wsh->wfs_tail,
wfs);
if (0 !=
json_array_append_new (
ac->a,
GNUNET_JSON_PACK (
TALER_JSON_pack_amount ("wire_fee",
&fees->wire),
TALER_JSON_pack_amount ("wad_fee",
&fees->wad),
TALER_JSON_pack_amount ("closing_fee",
&fees->closing),
GNUNET_JSON_pack_timestamp ("start_date",
start_date),
GNUNET_JSON_pack_timestamp ("end_date",
end_date),
GNUNET_JSON_pack_data_auto ("sig",
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;
uint64_t wg = wire_generation; /* must be obtained FIRST */
enum GNUNET_DB_QueryStatus qs;
struct WireStateHandle *wsh;
struct GNUNET_HashContext *hc;
wsh = GNUNET_new (struct WireStateHandle);
wsh->wire_generation = wg;
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);
wsh->http_status = MHD_HTTP_INTERNAL_SERVER_ERROR;
wsh->wire_reply
= TALER_MHD_make_error (TALER_EC_GENERIC_DB_FETCH_FAILED,
"get_wire_accounts");
return wsh;
}
if (0 == json_array_size (wire_accounts_array))
{
json_decref (wire_accounts_array);
wsh->http_status = MHD_HTTP_INTERNAL_SERVER_ERROR;
wsh->wire_reply
= TALER_MHD_make_error (TALER_EC_EXCHANGE_WIRE_NO_ACCOUNTS_CONFIGURED,
NULL);
return wsh;
}
wire_fee_object = json_object ();
GNUNET_assert (NULL != wire_fee_object);
wsh->cache_expiration = GNUNET_TIME_UNIT_FOREVER_ABS;
hc = GNUNET_CRYPTO_hash_context_start ();
{
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)
{
wsh->http_status = MHD_HTTP_INTERNAL_SERVER_ERROR;
wsh->wire_reply
= TALER_MHD_make_error (
TALER_EC_EXCHANGE_WIRE_INVALID_PAYTO_CONFIGURED,
payto_uri);
json_decref (wire_accounts_array);
json_decref (wire_fee_object);
GNUNET_CRYPTO_hash_context_abort (hc);
return wsh;
}
if (NULL == json_object_get (wire_fee_object,
wire_method))
{
struct AddContext ac = {
.wire_method = wire_method,
.wsh = wsh,
.a = json_array (),
.hc = hc
};
GNUNET_assert (NULL != ac.a);
qs = TEH_plugin->get_wire_fees (TEH_plugin->cls,
wire_method,
&add_wire_fee,
&ac);
if (0 > qs)
{
GNUNET_break (0);
json_decref (ac.a);
json_decref (wire_fee_object);
json_decref (wire_accounts_array);
GNUNET_free (wire_method);
wsh->http_status = MHD_HTTP_INTERNAL_SERVER_ERROR;
wsh->wire_reply
= TALER_MHD_make_error (TALER_EC_GENERIC_DB_FETCH_FAILED,
"get_wire_fees");
GNUNET_CRYPTO_hash_context_abort (hc);
return wsh;
}
if (0 == json_array_size (ac.a))
{
json_decref (ac.a);
json_decref (wire_accounts_array);
json_decref (wire_fee_object);
wsh->http_status = MHD_HTTP_INTERNAL_SERVER_ERROR;
wsh->wire_reply
= TALER_MHD_make_error (TALER_EC_EXCHANGE_WIRE_FEES_NOT_CONFIGURED,
wire_method);
GNUNET_free (wire_method);
GNUNET_CRYPTO_hash_context_abort (hc);
return wsh;
}
wsh->cache_expiration = GNUNET_TIME_absolute_min (ac.max_seen,
wsh->cache_expiration);
GNUNET_assert (0 ==
json_object_set_new (wire_fee_object,
wire_method,
ac.a));
}
GNUNET_free (wire_method);
}
}
wsh->wire_reply = TALER_MHD_MAKE_JSON_PACK (
GNUNET_JSON_pack_array_steal ("accounts",
wire_accounts_array),
GNUNET_JSON_pack_object_steal ("fees",
wire_fee_object),
GNUNET_JSON_pack_data_auto ("master_public_key",
&TEH_master_public_key));
{
struct GNUNET_TIME_Timestamp m;
m = GNUNET_TIME_absolute_to_timestamp (wsh->cache_expiration);
TALER_MHD_get_date_string (m.abs_time,
wsh->dat);
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"Setting 'Expires' header for '/wire' to '%s'\n",
wsh->dat);
GNUNET_break (MHD_YES ==
MHD_add_response_header (wsh->wire_reply,
MHD_HTTP_HEADER_EXPIRES,
wsh->dat));
}
/* Set cache control headers: our response varies depending on these headers */
GNUNET_break (MHD_YES ==
MHD_add_response_header (wsh->wire_reply,
MHD_HTTP_HEADER_VARY,
MHD_HTTP_HEADER_ACCEPT_ENCODING));
/* Information is always public, revalidate after 1 day */
GNUNET_break (MHD_YES ==
MHD_add_response_header (wsh->wire_reply,
MHD_HTTP_HEADER_CACHE_CONTROL,
"public,max-age=86400"));
{
struct GNUNET_HashCode h;
char etag[sizeof (h) * 2];
char *end;
GNUNET_CRYPTO_hash_context_finish (hc,
&h);
end = GNUNET_STRINGS_data_to_string (&h,
sizeof (h),
etag,
sizeof (etag));
*end = '\0';
wsh->etag = GNUNET_strdup (etag);
GNUNET_break (MHD_YES ==
MHD_add_response_header (wsh->wire_reply,
MHD_HTTP_HEADER_ETAG,
etag));
}
wsh->http_status = MHD_HTTP_OK;
return wsh;
}
void
TEH_wire_update_state (void)
{
struct GNUNET_DB_EventHeaderP es = {
.size = htons (sizeof (es)),
.type = htons (TALER_DBEVENT_EXCHANGE_WIRE_UPDATED),
};
TEH_plugin->event_notify (TEH_plugin->cls,
&es,
NULL,
0);
wire_generation++;
}
/**
* 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;
old_wsh = wire_state;
if ( (NULL == old_wsh) ||
(old_wsh->wire_generation < wire_generation) )
{
struct WireStateHandle *wsh;
TEH_check_invariants ();
wsh = build_wire_state ();
wire_state = wsh;
if (NULL != old_wsh)
destroy_wire_state (old_wsh);
TEH_check_invariants ();
return wsh;
}
return old_wsh;
}
MHD_RESULT
TEH_handler_wire (struct TEH_RequestContext *rc,
const char *const args[])
{
struct WireStateHandle *wsh;
(void) args;
wsh = get_wire_state ();
if (NULL == wsh)
return TALER_MHD_reply_with_error (rc->connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_EXCHANGE_GENERIC_BAD_CONFIGURATION,
NULL);
{
const char *etag;
etag = MHD_lookup_connection_value (rc->connection,
MHD_HEADER_KIND,
MHD_HTTP_HEADER_IF_NONE_MATCH);
if ( (NULL != etag) &&
(MHD_HTTP_OK == wsh->http_status) &&
(NULL != wsh->etag) &&
(0 == strcmp (etag,
wsh->etag)) )
{
MHD_RESULT ret;
struct MHD_Response *resp;
resp = MHD_create_response_from_buffer (0,
NULL,
MHD_RESPMEM_PERSISTENT);
TALER_MHD_add_global_headers (resp);
GNUNET_break (MHD_YES ==
MHD_add_response_header (resp,
MHD_HTTP_HEADER_EXPIRES,
wsh->dat));
GNUNET_break (MHD_YES ==
MHD_add_response_header (resp,
MHD_HTTP_HEADER_ETAG,
wsh->etag));
ret = MHD_queue_response (rc->connection,
MHD_HTTP_NOT_MODIFIED,
resp);
GNUNET_break (MHD_YES == ret);
MHD_destroy_response (resp);
return ret;
}
}
return MHD_queue_response (rc->connection,
wsh->http_status,
wsh->wire_reply);
}
const struct TALER_WireFeeSet *
TEH_wire_fees_by_time (
struct GNUNET_TIME_Timestamp ts,
const char *method)
{
struct WireStateHandle *wsh = get_wire_state ();
for (struct WireFeeSet *wfs = wsh->wfs_head;
NULL != wfs;
wfs = wfs->next)
{
if (0 != strcmp (method,
wfs->method))
continue;
if ( (GNUNET_TIME_timestamp_cmp (wfs->start_date,
>,
ts)) ||
(GNUNET_TIME_timestamp_cmp (ts,
>=,
wfs->end_date)) )
continue;
return &wfs->fees;
}
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"No wire fees for method `%s' at %s configured\n",
method,
GNUNET_TIME_timestamp2s (ts));
return NULL;
}
/* end of taler-exchange-httpd_wire.c */