exchange

bank_api_debit.c (11323B)

---

 /*
   This file is part of TALER
   Copyright (C) 2017--2023 Taler Systems SA
 
   TALER is free software; you can redistribute it and/or
   modify it under the terms of the GNU 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 bank-lib/bank_api_debit.c
  * @brief Implementation of the /history/outgoing
  *        requests of the bank's HTTP API.
  * @author Christian Grothoff
  * @author Marcello Stanisci
  */
 #include "bank_api_common.h"
 #include <microhttpd.h> /* just for HTTP status codes */
 #include "taler/taler_signatures.h"
 
 
 /**
  * How much longer than the application-specified timeout
  * do we wait (giving the server a chance to respond)?
  */
 #define GRACE_PERIOD_MS 1000
 
 
 /**
  * @brief A /history/outgoing Handle
  */
 struct TALER_BANK_DebitHistoryHandle
 {
 
   /**
    * The url for this request.
    */
   char *request_url;
 
   /**
    * Handle for the request.
    */
   struct GNUNET_CURL_Job *job;
 
   /**
    * Function to call with the result.
    */
   TALER_BANK_DebitHistoryCallback hcb;
 
   /**
    * Closure for @a cb.
    */
   void *hcb_cls;
 };
 
 
 /**
  * Parse history given in JSON format and invoke the callback on each item.
  *
  * @param hh handle to the account history request
  * @param history JSON array with the history
  * @return #GNUNET_OK if history was valid and @a rhistory and @a balance
  *         were set,
  *         #GNUNET_SYSERR if there was a protocol violation in @a history
  */
 static enum GNUNET_GenericReturnValue
 parse_account_history (struct TALER_BANK_DebitHistoryHandle *hh,
                        const json_t *history)
 {
   struct TALER_BANK_DebitHistoryResponse dhr = {
     .http_status = MHD_HTTP_OK,
     .ec = TALER_EC_NONE,
     .response = history
   };
   const json_t *history_array;
   struct GNUNET_JSON_Specification spec[] = {
     GNUNET_JSON_spec_array_const ("outgoing_transactions",
                                   &history_array),
     TALER_JSON_spec_full_payto_uri ("debit_account",
                                     &dhr.details.ok.debit_account_uri),
     GNUNET_JSON_spec_end ()
   };
 
   if (GNUNET_OK !=
       GNUNET_JSON_parse (history,
                          spec,
                          NULL,
                          NULL))
   {
     GNUNET_break_op (0);
     return GNUNET_SYSERR;
   }
   {
     size_t len = json_array_size (history_array);
     struct TALER_BANK_DebitDetails *dd;
 
     GNUNET_break_op (0 != len);
     dd = GNUNET_new_array (GNUNET_NZL (len),
                            struct TALER_BANK_DebitDetails);
     for (unsigned int i = 0; i<len; i++)
     {
       struct TALER_BANK_DebitDetails *td = &dd[i];
       bool no_debit_fee;
       struct GNUNET_JSON_Specification hist_spec[] = {
         TALER_JSON_spec_amount_any ("amount",
                                     &td->amount),
         GNUNET_JSON_spec_mark_optional (
           TALER_JSON_spec_amount_any ("debit_fee",
                                       &td->debit_fee),
           &no_debit_fee),
         GNUNET_JSON_spec_timestamp ("date",
                                     &td->execution_date),
         GNUNET_JSON_spec_uint64 ("row_id",
                                  &td->serial_id),
         GNUNET_JSON_spec_fixed_auto ("wtid",
                                      &td->wtid),
         TALER_JSON_spec_full_payto_uri ("credit_account",
                                         &td->credit_account_uri),
         TALER_JSON_spec_web_url ("exchange_base_url",
                                  &td->exchange_base_url),
         GNUNET_JSON_spec_mark_optional (
           GNUNET_JSON_spec_string ("metadata",
                                    &td->metadata),
           NULL),
         GNUNET_JSON_spec_end ()
       };
       json_t *transaction = json_array_get (history_array,
                                             i);
 
       if (GNUNET_OK !=
           GNUNET_JSON_parse (transaction,
                              hist_spec,
                              NULL,
                              NULL))
       {
         GNUNET_break_op (0);
         GNUNET_free (dd);
         return GNUNET_SYSERR;
       }
       if (no_debit_fee)
       {
         GNUNET_assert (GNUNET_OK ==
                        TALER_amount_set_zero (td->amount.currency,
                                               &td->debit_fee));
       }
       else if (GNUNET_YES !=
                TALER_amount_cmp_currency (&td->amount,
                                           &td->debit_fee))
       {
         GNUNET_break_op (0);
         GNUNET_free (dd);
         return GNUNET_SYSERR;
       }
     }
     dhr.details.ok.details_length = len;
     dhr.details.ok.details = dd;
     hh->hcb (hh->hcb_cls,
              &dhr);
     GNUNET_free (dd);
   }
   return GNUNET_OK;
 }
 
 
 /**
  * Function called when we're done processing the
  * HTTP /history/outgoing request.
  *
  * @param cls the `struct TALER_BANK_DebitHistoryHandle`
  * @param response_code HTTP response code, 0 on error
  * @param response parsed JSON result, NULL on error
  */
 static void
 handle_debit_history_finished (void *cls,
                                long response_code,
                                const void *response)
 {
   struct TALER_BANK_DebitHistoryHandle *hh = cls;
   struct TALER_BANK_DebitHistoryResponse dhr = {
     .http_status = response_code,
     .response = response
   };
 
   hh->job = NULL;
   switch (response_code)
   {
   case 0:
     dhr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
     break;
   case MHD_HTTP_OK:
     if (GNUNET_OK !=
         parse_account_history (hh,
                                dhr.response))
     {
       GNUNET_break_op (0);
       dhr.http_status = 0;
       dhr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
       break;
     }
     TALER_BANK_debit_history_cancel (hh);
     return;
   case MHD_HTTP_NO_CONTENT:
     break;
   case MHD_HTTP_BAD_REQUEST:
     /* This should never happen, either us or the bank is buggy
        (or API version conflict); just pass JSON reply to the application */
     GNUNET_break_op (0);
     dhr.ec = TALER_JSON_get_error_code (dhr.response);
     break;
   case MHD_HTTP_UNAUTHORIZED:
     /* Nothing really to verify, bank says the HTTP Authentication
        failed. May happen if HTTP authentication is used and the
        user supplied a wrong username/password combination. */
     dhr.ec = TALER_JSON_get_error_code (dhr.response);
     break;
   case MHD_HTTP_NOT_FOUND:
     /* Nothing really to verify: the bank is either unaware
        of the endpoint (not a bank), or of the account.
        We should pass the JSON (?) reply to the application */
     dhr.ec = TALER_JSON_get_error_code (dhr.response);
     break;
   case MHD_HTTP_INTERNAL_SERVER_ERROR:
     /* Server had an internal issue; we should retry, but this API
        leaves this to the application */
     dhr.ec = TALER_JSON_get_error_code (dhr.response);
     break;
   default:
     /* unexpected response code */
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                 "Unexpected response code %u\n",
                 (unsigned int) response_code);
     dhr.ec = TALER_JSON_get_error_code (dhr.response);
     break;
   }
   hh->hcb (hh->hcb_cls,
            &dhr);
   TALER_BANK_debit_history_cancel (hh);
 }
 
 
 struct TALER_BANK_DebitHistoryHandle *
 TALER_BANK_debit_history (struct GNUNET_CURL_Context *ctx,
                           const struct TALER_BANK_AuthenticationData *auth,
                           uint64_t start_row,
                           int64_t num_results,
                           struct GNUNET_TIME_Relative timeout,
                           TALER_BANK_DebitHistoryCallback hres_cb,
                           void *hres_cb_cls)
 {
   char url[128];
   struct TALER_BANK_DebitHistoryHandle *hh;
   CURL *eh;
   unsigned long long tms;
 
   if (0 == num_results)
   {
     GNUNET_break (0);
     return NULL;
   }
 
   tms = (unsigned long long) (timeout.rel_value_us
                               / GNUNET_TIME_UNIT_MILLISECONDS.rel_value_us);
   if ( ( (UINT64_MAX == start_row) &&
          (0 > num_results) ) ||
        ( (0 == start_row) &&
          (0 < num_results) ) )
   {
     if ( (0 < num_results) &&
          (! GNUNET_TIME_relative_is_zero (timeout)) )
       GNUNET_snprintf (url,
                        sizeof (url),
                        "history/outgoing?limit=%lld&timeout_ms=%llu",
                        (long long) num_results,
                        tms);
     else
       GNUNET_snprintf (url,
                        sizeof (url),
                        "history/outgoing?limit=%lld",
                        (long long) num_results);
   }
   else
   {
     if ( (0 < num_results) &&
          (! GNUNET_TIME_relative_is_zero (timeout)) )
       GNUNET_snprintf (url,
                        sizeof (url),
                        "history/outgoing?limit=%lld&offset=%llu&timeout_ms=%llu",
                        (long long) num_results,
                        (unsigned long long) start_row,
                        tms);
     else
       GNUNET_snprintf (url,
                        sizeof (url),
                        "history/outgoing?limit=%lld&offset=%llu",
                        (long long) num_results,
                        (unsigned long long) start_row);
   }
   hh = GNUNET_new (struct TALER_BANK_DebitHistoryHandle);
   hh->hcb = hres_cb;
   hh->hcb_cls = hres_cb_cls;
   hh->request_url = TALER_url_join (auth->wire_gateway_url,
                                     url,
                                     NULL);
   if (NULL == hh->request_url)
   {
     GNUNET_free (hh);
     GNUNET_break (0);
     return NULL;
   }
   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
               "Requesting debit history at `%s'\n",
               hh->request_url);
   eh = curl_easy_init ();
   if ( (NULL == eh) ||
        (GNUNET_OK !=
         TALER_BANK_setup_auth_ (eh,
                                 auth)) ||
        (CURLE_OK !=
         curl_easy_setopt (eh,
                           CURLOPT_URL,
                           hh->request_url)) )
   {
     GNUNET_break (0);
     TALER_BANK_debit_history_cancel (hh);
     if (NULL != eh)
       curl_easy_cleanup (eh);
     return NULL;
   }
   if (0 != tms)
   {
     GNUNET_break (CURLE_OK ==
                   curl_easy_setopt (eh,
                                     CURLOPT_TIMEOUT_MS,
                                     (long) tms + GRACE_PERIOD_MS));
   }
   hh->job = GNUNET_CURL_job_add2 (ctx,
                                   eh,
                                   NULL,
                                   &handle_debit_history_finished,
                                   hh);
   if (NULL == hh->job)
   {
     GNUNET_break (0);
     /* GNUNET_CURL_job_add2() already released @a eh */
     TALER_BANK_debit_history_cancel (hh);
     return NULL;
   }
   return hh;
 }
 
 
 void
 TALER_BANK_debit_history_cancel (struct TALER_BANK_DebitHistoryHandle *hh)
 {
   if (NULL != hh->job)
   {
     GNUNET_CURL_job_cancel (hh->job);
     hh->job = NULL;
   }
   GNUNET_free (hh->request_url);
   GNUNET_free (hh);
 }
 
 
 /* end of bank_api_debit.c */