diff options
Diffstat (limited to 'src/backend/taler-merchant-httpd_tip-reserve-helper.c')
| -rw-r--r-- | src/backend/taler-merchant-httpd_tip-reserve-helper.c | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/src/backend/taler-merchant-httpd_tip-reserve-helper.c b/src/backend/taler-merchant-httpd_tip-reserve-helper.c new file mode 100644 index 00000000..dc161955 --- /dev/null +++ b/src/backend/taler-merchant-httpd_tip-reserve-helper.c @@ -0,0 +1,329 @@ +/* + This file is part of TALER + (C) 2018--2019 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 General Public License for more details. + + You should have received a copy of the GNU General Public License along with + TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/> +*/ +/** + * @file backend/taler-merchant-httpd_tip-reserve-helper.c + * @brief helper functions to check the status of a tipping reserve + * @author Christian Grothoff + */ +#include "platform.h" +#include "taler-merchant-httpd_tip-reserve-helper.h" + + +/** + * Resume the given context and send the given response. Stores the response + * in the @a ctr and signals MHD to resume the connection. Also ensures MHD + * runs immediately. + * + * @param ctr tip reserve query helper context + * @param response_code response code to use + * @param response response data to send back + */ +static void +resume_with_response (struct CheckTipReserve *ctr, + unsigned int response_code, + struct MHD_Response *response) +{ + ctr->response_code = response_code; + ctr->response = response; + GNUNET_assert (GNUNET_YES == ctr->suspended); + ctr->suspended = GNUNET_NO; + MHD_resume_connection (ctr->connection); + TMH_trigger_daemon (); /* we resumed, kick MHD */ +} + + +/** + * Function called with the result of the /reserve/status request + * for the tipping reserve. Update our database balance with the + * result. + * + * @param cls closure with a `struct CheckTipReserve *' + * @param http_status HTTP response code, #MHD_HTTP_OK (200) for successful status request + * 0 if the exchange's reply is bogus (fails to follow the protocol) + * @param ec taler-specific error code, #TALER_EC_NONE on success + * @param[in] json original response in JSON format (useful only for diagnostics) + * @param balance current balance in the reserve, NULL on error + * @param history_length number of entries in the transaction history, 0 on error + * @param history detailed transaction history, NULL on error + */ +static void +handle_status (void *cls, + unsigned int http_status, + enum TALER_ErrorCode ec, + const json_t *json, + const struct TALER_Amount *balance, + unsigned int history_length, + const struct TALER_EXCHANGE_ReserveHistory *history) +{ + struct CheckTipReserve *ctr = cls; + + ctr->rsh = NULL; + ctr->reserve_expiration = GNUNET_TIME_UNIT_ZERO_ABS; + if (MHD_HTTP_NOT_FOUND == http_status) + { + resume_with_response (ctr, + MHD_HTTP_NOT_FOUND, + TMH_RESPONSE_make_error (ec, + "Reserve unknown at exchange")); + return; + } + if (MHD_HTTP_OK != http_status) + { + GNUNET_break_op (0); + resume_with_response (ctr, + MHD_HTTP_SERVICE_UNAVAILABLE, + TMH_RESPONSE_make_error (ec, + "Exchange returned error code for reserve status")); + return; + } + + if (0 == history_length) + { + GNUNET_break_op (0); + resume_with_response (ctr, + MHD_HTTP_SERVICE_UNAVAILABLE, + TMH_RESPONSE_make_error (TALER_EC_TIP_QUERY_RESERVE_HISTORY_FAILED_EMPTY, + "Exchange returned empty reserve history")); + return; + } + + if (TALER_EXCHANGE_RTT_DEPOSIT != history[0].type) + { + GNUNET_break_op (0); + resume_with_response (ctr, + MHD_HTTP_SERVICE_UNAVAILABLE, + TMH_RESPONSE_make_error (TALER_EC_TIP_QUERY_RESERVE_HISTORY_INVALID_NO_DEPOSIT, + "Exchange returned invalid reserve history")); + return; + } + + if (GNUNET_OK != + TALER_amount_get_zero (history[0].amount.currency, + &ctr->amount_withdrawn)) + { + GNUNET_break_op (0); + resume_with_response (ctr, + MHD_HTTP_SERVICE_UNAVAILABLE, + TMH_RESPONSE_make_error (TALER_EC_TIP_QUERY_RESERVE_HISTORY_INVALID_CURRENCY, + "Exchange returned invalid reserve history")); + return; + } + + if (0 != strcasecmp (TMH_currency, + history[0].amount.currency)) + { + GNUNET_break_op (0); + resume_with_response (ctr, + MHD_HTTP_SERVICE_UNAVAILABLE, + TMH_RESPONSE_make_error (TALER_EC_TIP_QUERY_RESERVE_CURRENCY_MISSMATCH, + "Exchange currency unexpected")); + return; + } + + if (GNUNET_YES == ctr->none_authorized) + ctr->amount_authorized = ctr->amount_withdrawn; + ctr->amount_deposited = ctr->amount_withdrawn; + + /* Update DB based on status! */ + for (unsigned int i=0;i<history_length;i++) + { + switch (history[i].type) + { + case TALER_EXCHANGE_RTT_DEPOSIT: + { + enum GNUNET_DB_QueryStatus qs; + struct GNUNET_HashCode uuid; + struct GNUNET_TIME_Absolute deposit_expiration; + + deposit_expiration = GNUNET_TIME_absolute_add (history[i].details.in_details.timestamp, + ctr->idle_reserve_expiration_time); + /* We're interested in the latest DEPOSIT timestamp, since this determines the + * reserve's expiration date. Note that the history isn't chronologically ordered. */ + ctr->reserve_expiration = GNUNET_TIME_absolute_max (ctr->reserve_expiration, + deposit_expiration); + GNUNET_CRYPTO_hash (history[i].details.in_details.wire_reference, + history[i].details.in_details.wire_reference_size, + &uuid); + qs = db->enable_tip_reserve_TR (db->cls, + &ctr->reserve_priv, + &uuid, + &history[i].amount, + deposit_expiration); + if (GNUNET_OK != + TALER_amount_add (&ctr->amount_deposited, + &ctr->amount_deposited, + &history[i].amount)) + { + GNUNET_break_op (0); + resume_with_response (ctr, + MHD_HTTP_INTERNAL_SERVER_ERROR, + TMH_RESPONSE_make_error (TALER_EC_TIP_QUERY_RESERVE_HISTORY_ARITHMETIC_ISSUE_DEPOSIT, + "Exchange returned invalid reserve history (amount overflow)")); + return; + } + + if (0 > qs) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + _("Database error updating tipping reserve status: %d\n"), + qs); + } + } + break; + case TALER_EXCHANGE_RTT_WITHDRAWAL: + if (GNUNET_OK != + TALER_amount_add (&ctr->amount_withdrawn, + &ctr->amount_withdrawn, + &history[i].amount)) + { + GNUNET_break_op (0); + resume_with_response (ctr, + MHD_HTTP_INTERNAL_SERVER_ERROR, + TMH_RESPONSE_make_error (TALER_EC_TIP_QUERY_RESERVE_HISTORY_ARITHMETIC_ISSUE_WITHDRAW, + "Exchange returned invalid reserve history (amount overflow)")); + return; + } + break; + case TALER_EXCHANGE_RTT_PAYBACK: + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + _("Encountered unsupported /payback operation on tipping reserve\n")); + /* FIXME: probably should count these like deposits!? */ + break; + case TALER_EXCHANGE_RTT_CLOSE: + /* We count 'closing' amounts just like withdrawals */ + if (GNUNET_OK != + TALER_amount_add (&ctr->amount_withdrawn, + &ctr->amount_withdrawn, + &history[i].amount)) + { + GNUNET_break_op (0); + resume_with_response (ctr, + MHD_HTTP_INTERNAL_SERVER_ERROR, + TMH_RESPONSE_make_error (TALER_EC_TIP_QUERY_RESERVE_HISTORY_ARITHMETIC_ISSUE_CLOSED, + "Exchange returned invalid reserve history (amount overflow)")); + return; + } + break; + } + } + + /* normal, non-error continuation */ + resume_with_response (ctr, + 0, + NULL); +} + + +/** + * Function called with the result of a #TMH_EXCHANGES_find_exchange() + * operation. Given the exchange handle, we will then interrogate + * the exchange about the status of the tipping reserve. + * + * @param cls closure with a `struct CheckTipReserve *` + * @param eh handle to the exchange context + * @param wire_fee current applicable wire fee for dealing with @a eh, NULL if not available + * @param exchange_trusted #GNUNET_YES if this exchange is trusted by config + */ +static void +exchange_cont (void *cls, + struct TALER_EXCHANGE_Handle *eh, + const struct TALER_Amount *wire_fee, + int exchange_trusted) +{ + struct CheckTipReserve *ctr = cls; + struct TALER_ReservePublicKeyP reserve_pub; + const struct TALER_EXCHANGE_Keys *keys; + + ctr->fo = NULL; + if (NULL == eh) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + _("Failed to contact exchange configured for tipping!\n")); + resume_with_response (ctr, + MHD_HTTP_SERVICE_UNAVAILABLE, + TMH_RESPONSE_make_error (TALER_EC_TIP_QUERY_RESERVE_STATUS_FAILED_EXCHANGE_DOWN, + "Unable to obtain /keys from exchange")); + return; + } + keys = TALER_EXCHANGE_get_keys (eh); + GNUNET_assert (NULL != keys); + ctr->idle_reserve_expiration_time + = keys->reserve_closing_delay; + GNUNET_CRYPTO_eddsa_key_get_public (&ctr->reserve_priv.eddsa_priv, + &reserve_pub.eddsa_pub); + ctr->rsh = TALER_EXCHANGE_reserve_status (eh, + &reserve_pub, + &handle_status, + ctr); +} + + +/** + * Check the status of the given reserve at the given exchange. + * Suspends the MHD connection while this is happening and resumes + * processing once we know the reserve status (or once an error + * code has been determined). + * + * @param[in,out] ctr context for checking the reserve status + * @param tip_exchange the URL of the exchange to query + */ +void +TMH_check_tip_reserve (struct CheckTipReserve *ctr, + const char *tip_exchange) +{ + MHD_suspend_connection (ctr->connection); + ctr->suspended = GNUNET_YES; + ctr->fo = TMH_EXCHANGES_find_exchange (tip_exchange, + NULL, + &exchange_cont, + ctr); + if (NULL == ctr->fo) + { + GNUNET_break (0); + resume_with_response (ctr, + MHD_HTTP_INTERNAL_SERVER_ERROR, + TMH_RESPONSE_make_error (TALER_EC_INTERNAL_INVARIANT_FAILURE, + "Unable to find exchange handle")); + } +} + + +/** + * Clean up any state that might be left in @a ctr. + * + * @param[in] context to clean up + */ +void +TMH_check_tip_reserve_cleanup (struct CheckTipReserve *ctr) +{ + if (NULL != ctr->rsh) + { + TALER_EXCHANGE_reserve_status_cancel (ctr->rsh); + ctr->rsh = NULL; + } + if (NULL != ctr->fo) + { + TMH_EXCHANGES_find_exchange_cancel (ctr->fo); + ctr->fo = NULL; + } + if (NULL != ctr->response) + { + MHD_destroy_response (ctr->response); + ctr->response = NULL; + } +} + +/* end of taler-merchant-httpd_tip-reserve-helper.c */ |