exchange

exchange_api_reserves_get.c (7500B)

---

 /*
   This file is part of TALER
   Copyright (C) 2014-2022 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 lib/exchange_api_reserves_get.c
  * @brief Implementation of the GET /reserves/$RESERVE_PUB requests
  * @author Christian Grothoff
  */
 #include "taler/platform.h"
 #include <jansson.h>
 #include <microhttpd.h> /* just for HTTP status codes */
 #include <gnunet/gnunet_util_lib.h>
 #include <gnunet/gnunet_json_lib.h>
 #include <gnunet/gnunet_curl_lib.h>
 #include "taler/taler_exchange_service.h"
 #include "taler/taler_json_lib.h"
 #include "exchange_api_handle.h"
 #include "taler/taler_signatures.h"
 #include "exchange_api_curl_defaults.h"
 
 
 /**
  * @brief A /reserves/ GET Handle
  */
 struct TALER_EXCHANGE_ReservesGetHandle
 {
 
   /**
    * The url for this request.
    */
   char *url;
 
   /**
    * Handle for the request.
    */
   struct GNUNET_CURL_Job *job;
 
   /**
    * Function to call with the result.
    */
   TALER_EXCHANGE_ReservesGetCallback cb;
 
   /**
    * Public key of the reserve we are querying.
    */
   struct TALER_ReservePublicKeyP reserve_pub;
 
   /**
    * Closure for @a cb.
    */
   void *cb_cls;
 
 };
 
 
 /**
  * We received an #MHD_HTTP_OK status code. Handle the JSON
  * response.
  *
  * @param rgh handle of the request
  * @param j JSON response
  * @return #GNUNET_OK on success
  */
 static enum GNUNET_GenericReturnValue
 handle_reserves_get_ok (struct TALER_EXCHANGE_ReservesGetHandle *rgh,
                         const json_t *j)
 {
   struct TALER_EXCHANGE_ReserveSummary rs = {
     .hr.reply = j,
     .hr.http_status = MHD_HTTP_OK
   };
   struct GNUNET_JSON_Specification spec[] = {
     TALER_JSON_spec_amount_any ("balance",
                                 &rs.details.ok.balance),
     GNUNET_JSON_spec_mark_optional (
       GNUNET_JSON_spec_string (
         "last_origin",
         (const char **) &rs.details.ok.last_origin.full_payto),
       NULL),
     GNUNET_JSON_spec_end ()
   };
 
   if (GNUNET_OK !=
       GNUNET_JSON_parse (j,
                          spec,
                          NULL,
                          NULL))
   {
     GNUNET_break_op (0);
     return GNUNET_SYSERR;
   }
   rgh->cb (rgh->cb_cls,
            &rs);
   rgh->cb = NULL;
   return GNUNET_OK;
 }
 
 
 /**
  * Function called when we're done processing the
  * HTTP /reserves/ GET request.
  *
  * @param cls the `struct TALER_EXCHANGE_ReservesGetHandle`
  * @param response_code HTTP response code, 0 on error
  * @param response parsed JSON result, NULL on error
  */
 static void
 handle_reserves_get_finished (void *cls,
                               long response_code,
                               const void *response)
 {
   struct TALER_EXCHANGE_ReservesGetHandle *rgh = cls;
   const json_t *j = response;
   struct TALER_EXCHANGE_ReserveSummary rs = {
     .hr.reply = j,
     .hr.http_status = (unsigned int) response_code
   };
 
   rgh->job = NULL;
   switch (response_code)
   {
   case 0:
     rs.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
     break;
   case MHD_HTTP_OK:
     if (GNUNET_OK !=
         handle_reserves_get_ok (rgh,
                                 j))
     {
       rs.hr.http_status = 0;
       rs.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
     }
     break;
   case MHD_HTTP_BAD_REQUEST:
     /* This should never happen, either us or the exchange is buggy
        (or API version conflict); just pass JSON reply to the application */
     rs.hr.ec = TALER_JSON_get_error_code (j);
     rs.hr.hint = TALER_JSON_get_error_hint (j);
     break;
   case MHD_HTTP_NOT_FOUND:
     /* Nothing really to verify, this should never
        happen, we should pass the JSON reply to the application */
     rs.hr.ec = TALER_JSON_get_error_code (j);
     rs.hr.hint = TALER_JSON_get_error_hint (j);
     break;
   case MHD_HTTP_INTERNAL_SERVER_ERROR:
     /* Server had an internal issue; we should retry, but this API
        leaves this to the application */
     rs.hr.ec = TALER_JSON_get_error_code (j);
     rs.hr.hint = TALER_JSON_get_error_hint (j);
     break;
   default:
     /* unexpected response code */
     GNUNET_break_op (0);
     rs.hr.ec = TALER_JSON_get_error_code (j);
     rs.hr.hint = TALER_JSON_get_error_hint (j);
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                 "Unexpected response code %u/%d for GET %s\n",
                 (unsigned int) response_code,
                 (int) rs.hr.ec,
                 rgh->url);
     break;
   }
   if (NULL != rgh->cb)
   {
     rgh->cb (rgh->cb_cls,
              &rs);
     rgh->cb = NULL;
   }
   TALER_EXCHANGE_reserves_get_cancel (rgh);
 }
 
 
 struct TALER_EXCHANGE_ReservesGetHandle *
 TALER_EXCHANGE_reserves_get (
   struct GNUNET_CURL_Context *ctx,
   const char *url,
   const struct TALER_ReservePublicKeyP *reserve_pub,
   struct GNUNET_TIME_Relative timeout,
   TALER_EXCHANGE_ReservesGetCallback cb,
   void *cb_cls)
 {
   struct TALER_EXCHANGE_ReservesGetHandle *rgh;
   CURL *eh;
   char arg_str[sizeof (struct TALER_ReservePublicKeyP) * 2 + 16 + 32];
   unsigned int tms
     = (unsigned int) timeout.rel_value_us
       / GNUNET_TIME_UNIT_MILLISECONDS.rel_value_us;
 
   {
     char pub_str[sizeof (struct TALER_ReservePublicKeyP) * 2];
     char *end;
     char timeout_str[32];
 
     end = GNUNET_STRINGS_data_to_string (
       reserve_pub,
       sizeof (*reserve_pub),
       pub_str,
       sizeof (pub_str));
     *end = '\0';
     GNUNET_snprintf (timeout_str,
                      sizeof (timeout_str),
                      "%u",
                      tms);
     if (0 == tms)
       GNUNET_snprintf (arg_str,
                        sizeof (arg_str),
                        "reserves/%s",
                        pub_str);
     else
       GNUNET_snprintf (arg_str,
                        sizeof (arg_str),
                        "reserves/%s?timeout_ms=%s",
                        pub_str,
                        timeout_str);
   }
   rgh = GNUNET_new (struct TALER_EXCHANGE_ReservesGetHandle);
   rgh->cb = cb;
   rgh->cb_cls = cb_cls;
   rgh->reserve_pub = *reserve_pub;
   rgh->url = TALER_url_join (url,
                              arg_str,
                              NULL);
   if (NULL == rgh->url)
   {
     GNUNET_free (rgh);
     return NULL;
   }
   eh = TALER_EXCHANGE_curl_easy_get_ (rgh->url);
   if (NULL == eh)
   {
     GNUNET_break (0);
     GNUNET_free (rgh->url);
     GNUNET_free (rgh);
     return NULL;
   }
   if (0 != tms)
   {
     GNUNET_break (CURLE_OK ==
                   curl_easy_setopt (eh,
                                     CURLOPT_TIMEOUT_MS,
                                     (long) (tms + 100L)));
   }
   rgh->job = GNUNET_CURL_job_add (ctx,
                                   eh,
                                   &handle_reserves_get_finished,
                                   rgh);
   return rgh;
 }
 
 
 void
 TALER_EXCHANGE_reserves_get_cancel (
   struct TALER_EXCHANGE_ReservesGetHandle *rgh)
 {
   if (NULL != rgh->job)
   {
     GNUNET_CURL_job_cancel (rgh->job);
     rgh->job = NULL;
   }
   GNUNET_free (rgh->url);
   GNUNET_free (rgh);
 }
 
 
 /* end of exchange_api_reserves_get.c */