summaryrefslogtreecommitdiff
path: root/src/lib/exchange_api_reserves_get.c
blob: 236cc0c73f42d3dbef404ae5cc2927f4d48c4307 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
/*
  This file is part of TALER
  Copyright (C) 2014-2020 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 "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_exchange_service.h"
#include "taler_json_lib.h"
#include "exchange_api_handle.h"
#include "taler_signatures.h"
#include "exchange_api_curl_defaults.h"


/**
 * @brief A /reserves/ GET Handle
 */
struct TALER_EXCHANGE_ReservesGetHandle
{

  /**
   * The connection to exchange this request handle will use
   */
  struct TALER_EXCHANGE_Handle *exchange;

  /**
   * 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 int
handle_reserves_get_ok (struct TALER_EXCHANGE_ReservesGetHandle *rgh,
                        const json_t *j)
{
  json_t *history;
  unsigned int len;
  struct TALER_Amount balance;
  struct TALER_Amount balance_from_history;
  struct GNUNET_JSON_Specification spec[] = {
    TALER_JSON_spec_amount ("balance", &balance),
    GNUNET_JSON_spec_end ()
  };
  struct TALER_EXCHANGE_HttpResponse hr = {
    .reply = j,
    .http_status = MHD_HTTP_OK
  };

  if (GNUNET_OK !=
      GNUNET_JSON_parse (j,
                         spec,
                         NULL,
                         NULL))
  {
    GNUNET_break_op (0);
    return GNUNET_SYSERR;
  }
  history = json_object_get (j,
                             "history");
  if (NULL == history)
  {
    GNUNET_break_op (0);
    return GNUNET_SYSERR;
  }
  len = json_array_size (history);
  {
    struct TALER_EXCHANGE_ReserveHistory *rhistory;

    rhistory = GNUNET_new_array (len,
                                 struct TALER_EXCHANGE_ReserveHistory);
    if (GNUNET_OK !=
        TALER_EXCHANGE_parse_reserve_history (rgh->exchange,
                                              history,
                                              &rgh->reserve_pub,
                                              balance.currency,
                                              &balance_from_history,
                                              len,
                                              rhistory))
    {
      GNUNET_break_op (0);
      TALER_EXCHANGE_free_reserve_history (rhistory,
                                           len);
      return GNUNET_SYSERR;
    }
    if (0 !=
        TALER_amount_cmp (&balance_from_history,
                          &balance))
    {
      /* exchange cannot add up balances!? */
      GNUNET_break_op (0);
      TALER_EXCHANGE_free_reserve_history (rhistory,
                                           len);
      return GNUNET_SYSERR;
    }
    if (NULL != rgh->cb)
    {
      rgh->cb (rgh->cb_cls,
               &hr,
               &balance,
               len,
               rhistory);
      rgh->cb = NULL;
    }
    TALER_EXCHANGE_free_reserve_history (rhistory,
                                         len);
  }
  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_HttpResponse hr = {
    .reply = j,
    .http_status = (unsigned int) response_code
  };

  rgh->job = NULL;
  switch (response_code)
  {
  case 0:
    hr.ec = TALER_EC_INVALID_RESPONSE;
    break;
  case MHD_HTTP_OK:
    if (GNUNET_OK !=
        handle_reserves_get_ok (rgh,
                                j))
    {
      hr.http_status = 0;
      hr.ec = TALER_EC_RESERVE_STATUS_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 */
    hr.ec = TALER_JSON_get_error_code (j);
    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 */
    hr.ec = TALER_JSON_get_error_code (j);
    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 */
    hr.ec = TALER_JSON_get_error_code (j);
    hr.hint = TALER_JSON_get_error_hint (j);
    break;
  default:
    /* unexpected response code */
    GNUNET_break_op (0);
    hr.ec = TALER_JSON_get_error_code (j);
    hr.hint = TALER_JSON_get_error_hint (j);
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "Unexpected response code %u/%d\n",
                (unsigned int) response_code,
                (int) hr.ec);
    break;
  }
  if (NULL != rgh->cb)
  {
    rgh->cb (rgh->cb_cls,
             &hr,
             NULL,
             0, NULL);
    rgh->cb = NULL;
  }
  TALER_EXCHANGE_reserves_get_cancel (rgh);
}


/**
 * Submit a request to obtain the transaction history of a reserve
 * from the exchange.  Note that while we return the full response to the
 * caller for further processing, we do already verify that the
 * response is well-formed (i.e. that signatures included in the
 * response are all valid and add up to the balance).  If the exchange's
 * reply is not well-formed, we return an HTTP status code of zero to
 * @a cb.
 *
 * @param exchange the exchange handle; the exchange must be ready to operate
 * @param reserve_pub public key of the reserve to inspect
 * @param cb the callback to call when a reply for this request is available
 * @param cb_cls closure for the above callback
 * @return a handle for this request; NULL if the inputs are invalid (i.e.
 *         signatures fail to verify).  In this case, the callback is not called.
 */
struct TALER_EXCHANGE_ReservesGetHandle *
TALER_EXCHANGE_reserves_get (struct TALER_EXCHANGE_Handle *exchange,
                             const struct
                             TALER_ReservePublicKeyP *reserve_pub,
                             TALER_EXCHANGE_ReservesGetCallback cb,
                             void *cb_cls)
{
  struct TALER_EXCHANGE_ReservesGetHandle *rgh;
  struct GNUNET_CURL_Context *ctx;
  CURL *eh;
  char arg_str[sizeof (struct TALER_ReservePublicKeyP) * 2 + 16];

  if (GNUNET_YES !=
      TEAH_handle_is_ready (exchange))
  {
    GNUNET_break (0);
    return NULL;
  }
  {
    char pub_str[sizeof (struct TALER_ReservePublicKeyP) * 2];
    char *end;

    end = GNUNET_STRINGS_data_to_string (reserve_pub,
                                         sizeof (struct
                                                 TALER_ReservePublicKeyP),
                                         pub_str,
                                         sizeof (pub_str));
    *end = '\0';
    GNUNET_snprintf (arg_str,
                     sizeof (arg_str),
                     "/reserves/%s",
                     pub_str);
  }
  rgh = GNUNET_new (struct TALER_EXCHANGE_ReservesGetHandle);
  rgh->exchange = exchange;
  rgh->cb = cb;
  rgh->cb_cls = cb_cls;
  rgh->reserve_pub = *reserve_pub;
  rgh->url = TEAH_path_to_url (exchange,
                               arg_str);
  eh = TALER_EXCHANGE_curl_easy_get_ (rgh->url);
  if (NULL == eh)
  {
    GNUNET_break (0);
    GNUNET_free (rgh->url);
    GNUNET_free (rgh);
    return NULL;
  }
  ctx = TEAH_handle_to_context (exchange);
  rgh->job = GNUNET_CURL_job_add (ctx,
                                  eh,
                                  &handle_reserves_get_finished,
                                  rgh);
  return rgh;
}


/**
 * Cancel a reserve status request.  This function cannot be used
 * on a request handle if a response is already served for it.
 *
 * @param rgh the reserve status request handle
 */
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_reserve.c */