implement merchant_api_post_transfers.c

1 files changed, 314 insertions, 0 deletions

diff --git a/src/lib/merchant_api_get_transfers.c b/src/lib/merchant_api_get_transfers.c
new file mode 100644
index 00000000..5743f2fe
--- /dev/null
+++ b/src/lib/merchant_api_get_transfers.c
@@ -0,0 +1,314 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2014-2017, 2020 Taler Systems SA
+
+  TALER is free software; you can redistribute it and/or modify it under the
+  terms of the GNU Lesser General Public License as published by the Free Software
+  Foundation; either version 2.1, 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 Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License along with
+  TALER; see the file COPYING.LGPL.  If not, see
+  <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file lib/merchant_api_track_transfer.c
+ * @brief Implementation of the /track/transfer request of the
+ * merchant's HTTP API
+ * @author Marcello Stanisci
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <curl/curl.h>
+#include <jansson.h>
+#include <microhttpd.h> /* just for HTTP status codes */
+#include <gnunet/gnunet_util_lib.h>
+#include <gnunet/gnunet_curl_lib.h>
+#include "taler_merchant_service.h"
+#include <taler/taler_json_lib.h>
+#include <taler/taler_signatures.h>
+
+
+/**
+ * @brief A Handle for tracking wire transfers.
+ */
+struct TALER_MERCHANT_TrackTransferHandle
+{
+
+  /**
+   * The url for this request.
+   */
+  char *url;
+
+  /**
+   * Handle for the request.
+   */
+  struct GNUNET_CURL_Job *job;
+
+  /**
+   * Function to call with the result.
+   */
+  TALER_MERCHANT_TrackTransferCallback cb;
+
+  /**
+   * Closure for @a cb.
+   */
+  void *cb_cls;
+
+  /**
+   * Reference to the execution context.
+   */
+  struct GNUNET_CURL_Context *ctx;
+};
+
+
+/**
+ * We got a #MHD_HTTP_OK response for the /track/transfer request.
+ * Check that the response is well-formed and if it is, call the
+ * callback.  If not, return an error code.
+ *
+ * This code is very similar to
+ * exchange_api_transfers_get.c::check_transfers_get_response_ok.
+ * (Except we do not check the signature, as that was done by the
+ * backend which we trust already.)
+ * Any changes should likely be reflected there as well.
+ *
+ * @param wdh handle to the operation
+ * @param json response we got
+ * @return #GNUNET_OK if we are done and all is well,
+ *         #GNUNET_SYSERR if the response was bogus
+ */
+static int
+check_transfers_get_response_ok (
+  struct TALER_MERCHANT_TrackTransferHandle *wdh,
+  const json_t *json)
+{
+  json_t *deposits;
+  struct GNUNET_HashCode h_wire;
+  struct TALER_Amount total_amount;
+  struct TALER_MerchantPublicKeyP merchant_pub;
+  unsigned int num_details;
+  struct TALER_ExchangePublicKeyP exchange_pub;
+  struct GNUNET_JSON_Specification inner_spec[] = {
+    TALER_JSON_spec_amount ("total", &total_amount),
+    GNUNET_JSON_spec_fixed_auto ("merchant_pub", &merchant_pub),
+    GNUNET_JSON_spec_fixed_auto ("h_wire", &h_wire),
+    GNUNET_JSON_spec_json ("deposits_sums", &deposits),
+    GNUNET_JSON_spec_fixed_auto ("exchange_pub", &exchange_pub),
+    GNUNET_JSON_spec_end ()
+  };
+  struct TALER_MERCHANT_HttpResponse hr = {
+    .http_status = MHD_HTTP_OK,
+    .reply = json
+  };
+
+  if (GNUNET_OK !=
+      GNUNET_JSON_parse (json,
+                         inner_spec,
+                         NULL, NULL))
+  {
+    GNUNET_break_op (0);
+    return GNUNET_SYSERR;
+  }
+  num_details = json_array_size (deposits);
+  {
+    struct TALER_MERCHANT_TrackTransferDetails details[num_details];
+
+    for (unsigned int i = 0; i<num_details; i++)
+    {
+      struct TALER_MERCHANT_TrackTransferDetails *detail = &details[i];
+      json_t *deposit = json_array_get (deposits, i);
+      struct GNUNET_JSON_Specification spec_detail[] = {
+        GNUNET_JSON_spec_string ("order_id", &detail->order_id),
+        TALER_JSON_spec_amount ("deposit_value", &detail->deposit_value),
+        TALER_JSON_spec_amount ("deposit_fee", &detail->deposit_fee),
+        GNUNET_JSON_spec_end ()
+      };
+
+      if (GNUNET_OK !=
+          GNUNET_JSON_parse (deposit,
+                             spec_detail,
+                             NULL, NULL))
+      {
+        GNUNET_break_op (0);
+        GNUNET_JSON_parse_free (inner_spec);
+        return GNUNET_SYSERR;
+      }
+    }
+    wdh->cb (wdh->cb_cls,
+             &hr,
+             &exchange_pub,
+             &h_wire,
+             &total_amount,
+             num_details,
+             details);
+  }
+  GNUNET_JSON_parse_free (inner_spec);
+  return GNUNET_OK;
+}
+
+
+/**
+ * Function called when we're done processing the
+ * HTTP /track/transfer request.
+ *
+ * @param cls the `struct TALER_MERCHANT_TrackTransferHandle`
+ * @param response_code HTTP response code, 0 on error
+ * @param json response body, NULL if not in JSON
+ */
+static void
+handle_transfers_get_finished (void *cls,
+                               long response_code,
+                               const void *response)
+{
+  struct TALER_MERCHANT_TrackTransferHandle *tdo = cls;
+  const json_t *json = response;
+  struct TALER_MERCHANT_HttpResponse hr = {
+    .http_status = (unsigned int) response_code,
+    .reply = json
+  };
+
+  tdo->job = NULL;
+  switch (response_code)
+  {
+  case 0:
+    hr.ec = TALER_EC_INVALID_RESPONSE;
+    break;
+  case MHD_HTTP_OK:
+    if (GNUNET_OK ==
+        check_transfers_get_response_ok (tdo,
+                                         json))
+    {
+      TALER_MERCHANT_track_transfer_cancel (tdo);
+      return;
+    }
+    GNUNET_break_op (0);
+    hr.http_status = 0;
+    hr.ec = TALER_EC_INVALID_RESPONSE; // TODO: use more specific code!
+    break;
+  case MHD_HTTP_FAILED_DEPENDENCY:
+    /* Not a reason to break execution.  */
+    TALER_MERCHANT_parse_error_details_ (json,
+                                         response_code,
+                                         &hr);
+    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 (json);
+    hr.hint = TALER_JSON_get_error_hint (json);
+    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 (json);
+    hr.hint = TALER_JSON_get_error_hint (json);
+    break;
+  default:
+    /* unexpected response code */
+    GNUNET_break_op (0);
+    TALER_MERCHANT_parse_error_details_ (json,
+                                         response_code,
+                                         &hr);
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unexpected response code %u/%d\n",
+                (unsigned int) response_code,
+                (int) hr.ec);
+    response_code = 0;
+    break;
+  }
+  tdo->cb (tdo->cb_cls,
+           &hr,
+           NULL,
+           NULL,
+           NULL,
+           0,
+           NULL);
+  TALER_MERCHANT_track_transfer_cancel (tdo);
+}
+
+
+/**
+ * Request backend to return transfers associated with a given wtid.
+ *
+ * @param ctx execution context
+ * @param backend_url base URL of the backend
+ * @param wire_method wire method used for the wire transfer
+ * @param wtid base32 string indicating a wtid
+ * @param exchange_url base URL of the exchange in charge of returning the wanted information
+ * @param track_transfer_cb the callback to call when a reply for this request is available
+ * @param track_transfer_cb_cls closure for @a contract_cb
+ * @return a handle for this request
+ */
+struct TALER_MERCHANT_TrackTransferHandle *
+TALER_MERCHANT_track_transfer (
+  struct GNUNET_CURL_Context *ctx,
+  const char *backend_url,
+  const char *wire_method,
+  const struct TALER_WireTransferIdentifierRawP *wtid,
+  const char *exchange_url,
+  TALER_MERCHANT_TrackTransferCallback track_transfer_cb,
+  void *track_transfer_cb_cls)
+{
+  struct TALER_MERCHANT_TrackTransferHandle *tdo;
+  CURL *eh;
+  char *wtid_str;
+
+  wtid_str = GNUNET_STRINGS_data_to_string_alloc (
+    wtid,
+    sizeof (struct TALER_WireTransferIdentifierRawP));
+  tdo = GNUNET_new (struct TALER_MERCHANT_TrackTransferHandle);
+  tdo->ctx = ctx;
+  tdo->cb = track_transfer_cb; // very last to be called
+  tdo->cb_cls = track_transfer_cb_cls;
+  tdo->url = TALER_url_join (backend_url, "track/transfer",
+                             "wtid", wtid_str,
+                             "exchange", exchange_url,
+                             "wire_method", wire_method,
+                             NULL);
+  GNUNET_free (wtid_str);
+  if (NULL == tdo->url)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Could not construct request URL.\n");
+    GNUNET_free (tdo);
+    return NULL;
+  }
+  eh = curl_easy_init ();
+  GNUNET_assert (CURLE_OK ==
+                 curl_easy_setopt (eh,
+                                   CURLOPT_URL,
+                                   tdo->url));
+  tdo->job = GNUNET_CURL_job_add (ctx,
+                                  eh,
+                                  GNUNET_YES,
+                                  &handle_transfers_get_finished,
+                                  tdo);
+  return tdo;
+}
+
+
+/**
+ * Cancel a /track/transfer request.  This function cannot be used
+ * on a request handle if a response is already served for it.
+ *
+ * @param tdo handle to the tracking operation being cancelled
+ */
+void
+TALER_MERCHANT_track_transfer_cancel (
+  struct TALER_MERCHANT_TrackTransferHandle *tdo)
+{
+  if (NULL != tdo->job)
+  {
+    GNUNET_CURL_job_cancel (tdo->job);
+    tdo->job = NULL;
+  }
+  GNUNET_free (tdo->url);
+  GNUNET_free (tdo);
+}
+
+
+/* end of merchant_api_track_transfer.c */