merchant

Merchant backend to process payments, run by merchants
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taler-merchant-httpd_post-private-webhooks.c (7530B)


      1 /*
      2   This file is part of TALER
      3   (C) 2022 Taler Systems SA
      4 
      5   TALER is free software; you can redistribute it and/or modify
      6   it under the terms of the GNU Affero General Public License as
      7   published by the Free Software Foundation; either version 3,
      8   or (at your option) any later version.
      9 
     10   TALER is distributed in the hope that it will be useful, but
     11   WITHOUT ANY WARRANTY; without even the implied warranty of
     12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     13   GNU General Public License for more details.
     14 
     15   You should have received a copy of the GNU General Public
     16   License along with TALER; see the file COPYING.  If not,
     17   see <http://www.gnu.org/licenses/>
     18 */
     19 
     20 /**
     21  * @file src/backend/taler-merchant-httpd_post-private-webhooks.c
     22  * @brief implementing POST /webhooks request handling
     23  * @author Priscilla HUANG
     24  */
     25 #include "platform.h"
     26 #include "taler-merchant-httpd_post-private-webhooks.h"
     27 #include "taler-merchant-httpd_helper.h"
     28 #include <taler/taler_json_lib.h>
     29 #include "merchant-database/insert_webhook.h"
     30 #include "merchant-database/lookup_webhook.h"
     31 #include "merchant-database/start.h"
     32 
     33 /**
     34  * How often do we retry the simple INSERT database transaction?
     35  */
     36 #define MAX_RETRIES 3
     37 
     38 
     39 /**
     40  * Check if the two webhooks are identical.
     41  *
     42  * @param w1 webhook to compare
     43  * @param w2 other webhook to compare
     44  * @return true if they are 'equal', false if not or of payto_uris is not an array
     45  */
     46 static bool
     47 webhooks_equal (const struct TALER_MERCHANTDB_WebhookDetails *w1,
     48                 const struct TALER_MERCHANTDB_WebhookDetails *w2)
     49 {
     50   return ( (0 == strcmp (w1->event_type,
     51                          w2->event_type)) &&
     52            (0 == strcmp (w1->url,
     53                          w2->url)) &&
     54            (0 == strcmp (w1->http_method,
     55                          w2->http_method)) &&
     56            ( ( (NULL == w1->header_template) &&
     57                (NULL == w2->header_template) ) ||
     58              ( (NULL != w1->header_template) &&
     59                (NULL != w2->header_template) &&
     60                (0 == strcmp (w1->header_template,
     61                              w2->header_template)) ) ) &&
     62            ( ( (NULL == w1->body_template) &&
     63                (NULL == w2->body_template) ) ||
     64              ( (NULL != w1->body_template) &&
     65                (NULL != w2->body_template) &&
     66                (0 == strcmp (w1->body_template,
     67                              w2->body_template)) )  ) );
     68 }
     69 
     70 
     71 enum MHD_Result
     72 TMH_private_post_webhooks (const struct TMH_RequestHandler *rh,
     73                            struct MHD_Connection *connection,
     74                            struct TMH_HandlerContext *hc)
     75 {
     76   struct TMH_MerchantInstance *mi = hc->instance;
     77   struct TALER_MERCHANTDB_WebhookDetails wb = { 0 };
     78   const char *webhook_id;
     79   enum GNUNET_DB_QueryStatus qs;
     80   struct GNUNET_JSON_Specification spec[] = {
     81     GNUNET_JSON_spec_string ("webhook_id",
     82                              &webhook_id),
     83     GNUNET_JSON_spec_string ("event_type",
     84                              (const char **) &wb.event_type),
     85     TALER_JSON_spec_web_url ("url",
     86                              (const char **) &wb.url),
     87     GNUNET_JSON_spec_string ("http_method",
     88                              (const char **) &wb.http_method),
     89     GNUNET_JSON_spec_mark_optional (
     90       GNUNET_JSON_spec_string ("header_template",
     91                                (const char **) &wb.header_template),
     92       NULL),
     93     GNUNET_JSON_spec_mark_optional (
     94       GNUNET_JSON_spec_string ("body_template",
     95                                (const char **) &wb.body_template),
     96       NULL),
     97     GNUNET_JSON_spec_end ()
     98   };
     99 
    100   GNUNET_assert (NULL != mi);
    101   {
    102     enum GNUNET_GenericReturnValue res;
    103 
    104     res = TALER_MHD_parse_json_data (connection,
    105                                      hc->request_body,
    106                                      spec);
    107     if (GNUNET_OK != res)
    108     {
    109       GNUNET_break_op (0);
    110       return (GNUNET_NO == res)
    111              ? MHD_YES
    112              : MHD_NO;
    113     }
    114   }
    115 
    116 
    117   /* finally, interact with DB until no serialization error */
    118   for (unsigned int i = 0; i<MAX_RETRIES; i++)
    119   {
    120     /* Test if a webhook of this id is known */
    121     struct TALER_MERCHANTDB_WebhookDetails ewb;
    122 
    123     if (GNUNET_OK !=
    124         TALER_MERCHANTDB_start (TMH_db,
    125                                 "/post webhooks"))
    126     {
    127       GNUNET_break (0);
    128       GNUNET_JSON_parse_free (spec);
    129       return TALER_MHD_reply_with_error (connection,
    130                                          MHD_HTTP_INTERNAL_SERVER_ERROR,
    131                                          TALER_EC_GENERIC_DB_START_FAILED,
    132                                          NULL);
    133     }
    134     qs = TALER_MERCHANTDB_lookup_webhook (TMH_db,
    135                                           mi->settings.id,
    136                                           webhook_id,
    137                                           &ewb);
    138     switch (qs)
    139     {
    140     case GNUNET_DB_STATUS_HARD_ERROR:
    141       /* Clean up and fail hard */
    142       GNUNET_break (0);
    143       TALER_MERCHANTDB_rollback (TMH_db);
    144       GNUNET_JSON_parse_free (spec);
    145       return TALER_MHD_reply_with_error (connection,
    146                                          MHD_HTTP_INTERNAL_SERVER_ERROR,
    147                                          TALER_EC_GENERIC_DB_FETCH_FAILED,
    148                                          NULL);
    149     case GNUNET_DB_STATUS_SOFT_ERROR:
    150       /* restart transaction */
    151       goto retry;
    152     case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
    153       /* Good, we can proceed! */
    154       break;
    155     case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
    156       /* idempotency check: is ewb == wb? */
    157       {
    158         bool eq;
    159 
    160         eq = webhooks_equal (&wb,
    161                              &ewb);
    162         TALER_MERCHANTDB_webhook_details_free (&ewb);
    163         TALER_MERCHANTDB_rollback (TMH_db);
    164         GNUNET_JSON_parse_free (spec);
    165         return eq
    166           ? TALER_MHD_reply_static (connection,
    167                                     MHD_HTTP_NO_CONTENT,
    168                                     NULL,
    169                                     NULL,
    170                                     0)
    171           : TALER_MHD_reply_with_error (connection,
    172                                         MHD_HTTP_CONFLICT,
    173                                         TALER_EC_MERCHANT_PRIVATE_POST_WEBHOOKS_CONFLICT_WEBHOOK_EXISTS,
    174                                         webhook_id);
    175       }
    176     } /* end switch (qs) */
    177 
    178     qs = TALER_MERCHANTDB_insert_webhook (TMH_db,
    179                                           mi->settings.id,
    180                                           webhook_id,
    181                                           &wb);
    182     if (GNUNET_DB_STATUS_HARD_ERROR == qs)
    183     {
    184       TALER_MERCHANTDB_rollback (TMH_db);
    185       break;
    186     }
    187     if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT == qs)
    188     {
    189       qs = TALER_MERCHANTDB_commit (TMH_db);
    190       if (GNUNET_DB_STATUS_SOFT_ERROR != qs)
    191         break;
    192     }
    193 retry:
    194     GNUNET_assert (GNUNET_DB_STATUS_SOFT_ERROR == qs);
    195     TALER_MERCHANTDB_rollback (TMH_db);
    196   } /* for RETRIES loop */
    197   GNUNET_JSON_parse_free (spec);
    198   if (qs < 0)
    199   {
    200     GNUNET_break (0);
    201     return TALER_MHD_reply_with_error (
    202       connection,
    203       MHD_HTTP_INTERNAL_SERVER_ERROR,
    204       (GNUNET_DB_STATUS_SOFT_ERROR == qs)
    205       ? TALER_EC_GENERIC_DB_SOFT_FAILURE
    206       : TALER_EC_GENERIC_DB_COMMIT_FAILED,
    207       NULL);
    208   }
    209   return TALER_MHD_reply_static (connection,
    210                                  MHD_HTTP_NO_CONTENT,
    211                                  NULL,
    212                                  NULL,
    213                                  0);
    214 }
    215 
    216 
    217 /* end of taler-merchant-httpd_post-private-webhooks.c */