merchant

Merchant backend to process payments, run by merchants
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taler-merchant-httpd_private-post-webhooks.c (7290B)


      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 taler-merchant-httpd_private-post-webhooks.c
     22  * @brief implementing POST /webhooks request handling
     23  * @author Priscilla HUANG
     24  */
     25 #include "platform.h"
     26 #include "taler-merchant-httpd_private-post-webhooks.h"
     27 #include "taler-merchant-httpd_helper.h"
     28 #include <taler/taler_json_lib.h>
     29 
     30 
     31 /**
     32  * How often do we retry the simple INSERT database transaction?
     33  */
     34 #define MAX_RETRIES 3
     35 
     36 
     37 /**
     38  * Check if the two webhooks are identical.
     39  *
     40  * @param w1 webhook to compare
     41  * @param w2 other webhook to compare
     42  * @return true if they are 'equal', false if not or of payto_uris is not an array
     43  */
     44 static bool
     45 webhooks_equal (const struct TALER_MERCHANTDB_WebhookDetails *w1,
     46                 const struct TALER_MERCHANTDB_WebhookDetails *w2)
     47 {
     48   return ( (0 == strcmp (w1->event_type,
     49                          w2->event_type)) &&
     50            (0 == strcmp (w1->url,
     51                          w2->url)) &&
     52            (0 == strcmp (w1->http_method,
     53                          w2->http_method)) &&
     54            ( ( (NULL == w1->header_template) &&
     55                (NULL == w2->header_template) ) ||
     56              ( (NULL != w1->header_template) &&
     57                (NULL != w2->header_template) &&
     58                (0 == strcmp (w1->header_template,
     59                              w2->header_template)) ) ) &&
     60            ( ( (NULL == w1->body_template) &&
     61                (NULL == w2->body_template) ) ||
     62              ( (NULL != w1->body_template) &&
     63                (NULL != w2->body_template) &&
     64                (0 == strcmp (w1->body_template,
     65                              w2->body_template)) )  ) );
     66 }
     67 
     68 
     69 MHD_RESULT
     70 TMH_private_post_webhooks (const struct TMH_RequestHandler *rh,
     71                            struct MHD_Connection *connection,
     72                            struct TMH_HandlerContext *hc)
     73 {
     74   struct TMH_MerchantInstance *mi = hc->instance;
     75   struct TALER_MERCHANTDB_WebhookDetails wb = { 0 };
     76   const char *webhook_id;
     77   enum GNUNET_DB_QueryStatus qs;
     78   struct GNUNET_JSON_Specification spec[] = {
     79     GNUNET_JSON_spec_string ("webhook_id",
     80                              &webhook_id),
     81     GNUNET_JSON_spec_string ("event_type",
     82                              (const char **) &wb.event_type),
     83     TALER_JSON_spec_web_url ("url",
     84                              (const char **) &wb.url),
     85     GNUNET_JSON_spec_string ("http_method",
     86                              (const char **) &wb.http_method),
     87     GNUNET_JSON_spec_mark_optional (
     88       GNUNET_JSON_spec_string ("header_template",
     89                                (const char **) &wb.header_template),
     90       NULL),
     91     GNUNET_JSON_spec_mark_optional (
     92       GNUNET_JSON_spec_string ("body_template",
     93                                (const char **) &wb.body_template),
     94       NULL),
     95     GNUNET_JSON_spec_end ()
     96   };
     97 
     98   GNUNET_assert (NULL != mi);
     99   {
    100     enum GNUNET_GenericReturnValue res;
    101 
    102     res = TALER_MHD_parse_json_data (connection,
    103                                      hc->request_body,
    104                                      spec);
    105     if (GNUNET_OK != res)
    106     {
    107       GNUNET_break_op (0);
    108       return (GNUNET_NO == res)
    109              ? MHD_YES
    110              : MHD_NO;
    111     }
    112   }
    113 
    114 
    115   /* finally, interact with DB until no serialization error */
    116   for (unsigned int i = 0; i<MAX_RETRIES; i++)
    117   {
    118     /* Test if a webhook of this id is known */
    119     struct TALER_MERCHANTDB_WebhookDetails ewb;
    120 
    121     if (GNUNET_OK !=
    122         TMH_db->start (TMH_db->cls,
    123                        "/post webhooks"))
    124     {
    125       GNUNET_break (0);
    126       GNUNET_JSON_parse_free (spec);
    127       return TALER_MHD_reply_with_error (connection,
    128                                          MHD_HTTP_INTERNAL_SERVER_ERROR,
    129                                          TALER_EC_GENERIC_DB_START_FAILED,
    130                                          NULL);
    131     }
    132     qs = TMH_db->lookup_webhook (TMH_db->cls,
    133                                  mi->settings.id,
    134                                  webhook_id,
    135                                  &ewb);
    136     switch (qs)
    137     {
    138     case GNUNET_DB_STATUS_HARD_ERROR:
    139       /* Clean up and fail hard */
    140       GNUNET_break (0);
    141       TMH_db->rollback (TMH_db->cls);
    142       GNUNET_JSON_parse_free (spec);
    143       return TALER_MHD_reply_with_error (connection,
    144                                          MHD_HTTP_INTERNAL_SERVER_ERROR,
    145                                          TALER_EC_GENERIC_DB_FETCH_FAILED,
    146                                          NULL);
    147     case GNUNET_DB_STATUS_SOFT_ERROR:
    148       /* restart transaction */
    149       goto retry;
    150     case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
    151       /* Good, we can proceed! */
    152       break;
    153     case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
    154       /* idempotency check: is ewb == wb? */
    155       {
    156         bool eq;
    157 
    158         eq = webhooks_equal (&wb,
    159                              &ewb);
    160         TALER_MERCHANTDB_webhook_details_free (&ewb);
    161         TMH_db->rollback (TMH_db->cls);
    162         GNUNET_JSON_parse_free (spec);
    163         return eq
    164           ? TALER_MHD_reply_static (connection,
    165                                     MHD_HTTP_NO_CONTENT,
    166                                     NULL,
    167                                     NULL,
    168                                     0)
    169           : TALER_MHD_reply_with_error (connection,
    170                                         MHD_HTTP_CONFLICT,
    171                                         TALER_EC_MERCHANT_PRIVATE_POST_WEBHOOKS_CONFLICT_WEBHOOK_EXISTS,
    172                                         webhook_id);
    173       }
    174     } /* end switch (qs) */
    175 
    176     qs = TMH_db->insert_webhook (TMH_db->cls,
    177                                  mi->settings.id,
    178                                  webhook_id,
    179                                  &wb);
    180     if (GNUNET_DB_STATUS_HARD_ERROR == qs)
    181     {
    182       TMH_db->rollback (TMH_db->cls);
    183       break;
    184     }
    185     if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT == qs)
    186     {
    187       qs = TMH_db->commit (TMH_db->cls);
    188       if (GNUNET_DB_STATUS_SOFT_ERROR != qs)
    189         break;
    190     }
    191 retry:
    192     GNUNET_assert (GNUNET_DB_STATUS_SOFT_ERROR == qs);
    193     TMH_db->rollback (TMH_db->cls);
    194   } /* for RETRIES loop */
    195   GNUNET_JSON_parse_free (spec);
    196   if (qs < 0)
    197   {
    198     GNUNET_break (0);
    199     return TALER_MHD_reply_with_error (
    200       connection,
    201       MHD_HTTP_INTERNAL_SERVER_ERROR,
    202       (GNUNET_DB_STATUS_SOFT_ERROR == qs)
    203       ? TALER_EC_GENERIC_DB_SOFT_FAILURE
    204       : TALER_EC_GENERIC_DB_COMMIT_FAILED,
    205       NULL);
    206   }
    207   return TALER_MHD_reply_static (connection,
    208                                  MHD_HTTP_NO_CONTENT,
    209                                  NULL,
    210                                  NULL,
    211                                  0);
    212 }
    213 
    214 
    215 /* end of taler-merchant-httpd_private-post-webhooks.c */