merchant

taler-merchant-httpd_post-private-donau.c (10355B)

---

 /*
   This file is part of TALER
   Copyright (C) 2024, 2025 Taler Systems SA
 
   TALER is free software; you can redistribute it and/or modify it under the
   terms of the GNU Affero 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 src/backend/taler-merchant-httpd_post-private-donau.c
  * @brief implementation of POST /donau
  * @author Bohdan Potuzhnyi
  * @author Vlada Svirsh
  * @author Christian Grothoff
  */
 #include "platform.h"
 #include <jansson.h>
 #include "donau/donau_service.h"
 #include <taler/taler_json_lib.h>
 #include <taler/taler_dbevents.h>
 #include "taler/taler_merchant_service.h"
 #include "taler-merchant-httpd_post-private-donau.h"
 #include "merchant-database/check_donau_instance.h"
 #include "merchant-database/insert_donau_instance.h"
 #include "merchant-database/event_listen.h"
 #include "merchant-database/event_notify.h"
 
 /**
  * Context for the POST /donau request handler.
  */
 struct PostDonauCtx
 {
   /**
    * Stored in a DLL.
    */
   struct PostDonauCtx *next;
 
   /**
    * Stored in a DLL.
    */
   struct PostDonauCtx *prev;
 
   /**
    * Connection to the MHD server
    */
   struct MHD_Connection *connection;
 
   /**
    * Context of the request handler.
    */
   struct TMH_HandlerContext *hc;
 
   /**
    * URL of the DONAU service
    * to which the charity belongs.
    */
   const char *donau_url;
 
   /**
    * ID of the charity in the DONAU service.
    */
   uint64_t charity_id;
 
   /**
    * Handle returned by DONAU_charities_get(); needed to cancel on
    * connection abort, etc.
    */
   struct DONAU_CharityGetHandle *get_handle;
 
   /**
    * Response to return.
    */
   struct MHD_Response *response;
 
   /**
    * HTTP status for @e response.
    */
   unsigned int http_status;
 
   /**
    * #GNUNET_YES if we are suspended,
    * #GNUNET_NO if not,
    * #GNUNET_SYSERR on shutdown
    */
   enum GNUNET_GenericReturnValue suspended;
 };
 
 
 /**
  * Head of active pay context DLL.
  */
 static struct PostDonauCtx *pdc_head;
 
 /**
  * Tail of active pay context DLL.
  */
 static struct PostDonauCtx *pdc_tail;
 
 
 void
 TMH_force_post_donau_resume ()
 {
   for (struct PostDonauCtx *pdc = pdc_head;
        NULL != pdc;
        pdc = pdc->next)
   {
     if (GNUNET_YES == pdc->suspended)
     {
       pdc->suspended = GNUNET_SYSERR;
       MHD_resume_connection (pdc->connection);
     }
   }
 }
 
 
 /**
  * Callback for DONAU_charities_get() to handle the response.
  *
  * @param cls closure with PostDonauCtx
  * @param gcr response from Donau
  */
 static void
 donau_charity_get_cb (void *cls,
                       const struct DONAU_GetCharityResponse *gcr)
 {
   struct PostDonauCtx *pdc = cls;
   enum GNUNET_DB_QueryStatus qs;
 
   pdc->get_handle = NULL;
   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
               "Processing DONAU charity get response");
   /* Anything but 200 => propagate Donau’s response. */
   if (MHD_HTTP_OK != gcr->hr.http_status)
   {
     pdc->http_status = MHD_HTTP_BAD_GATEWAY;
     pdc->response = TALER_MHD_MAKE_JSON_PACK (
       TALER_MHD_PACK_EC (gcr->hr.ec),
       GNUNET_JSON_pack_uint64 ("donau_http_status",
                                gcr->hr.http_status));
     pdc->suspended = GNUNET_NO;
     MHD_resume_connection (pdc->connection);
     TALER_MHD_daemon_trigger ();
     return;
   }
 
   if (0 !=
       GNUNET_memcmp (&gcr->details.ok.charity.charity_pub.eddsa_pub,
                      &pdc->hc->instance->merchant_pub.eddsa_pub))
   {
     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                 "Charity key at donau does not match our merchant key\n");
     pdc->http_status = MHD_HTTP_CONFLICT;
     pdc->response = TALER_MHD_make_error (
       TALER_EC_GENERIC_PARAMETER_MALFORMED,
       "charity_pub != merchant_pub");
     MHD_resume_connection (pdc->connection);
     TALER_MHD_daemon_trigger ();
     return;
   }
 
   qs = TALER_MERCHANTDB_insert_donau_instance (TMH_db,
                                                pdc->donau_url,
                                                &gcr->details.ok.charity,
                                                pdc->charity_id);
   switch (qs)
   {
   case GNUNET_DB_STATUS_HARD_ERROR:
     GNUNET_break (0);
     pdc->http_status = MHD_HTTP_INTERNAL_SERVER_ERROR;
     pdc->response = TALER_MHD_make_error (
       TALER_EC_GENERIC_DB_STORE_FAILED,
       "insert_donau_instance");
     break;
   case GNUNET_DB_STATUS_SOFT_ERROR:
     GNUNET_break (0);
     pdc->http_status = MHD_HTTP_INTERNAL_SERVER_ERROR;
     pdc->response = TALER_MHD_make_error (
       TALER_EC_GENERIC_DB_STORE_FAILED,
       "insert_donau_instance");
     break;
   case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
     /* presumably idempotent + concurrent, no need to notify, but still respond */
     pdc->http_status = MHD_HTTP_NO_CONTENT;
     pdc->response = MHD_create_response_from_buffer_static (0,
                                                             NULL);
     TALER_MHD_add_global_headers (pdc->response,
                                   false);
     break;
   case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
     {
       struct GNUNET_DB_EventHeaderP es = {
         .size = htons (sizeof (es)),
         .type = htons (TALER_DBEVENT_MERCHANT_DONAU_KEYS)
       };
 
       TALER_MERCHANTDB_event_notify (TMH_db,
                                      &es,
                                      pdc->donau_url,
                                      strlen (pdc->donau_url) + 1);
       pdc->http_status = MHD_HTTP_NO_CONTENT;
       pdc->response = MHD_create_response_from_buffer_static (0,
                                                               NULL);
       TALER_MHD_add_global_headers (pdc->response,
                                     false);
       break;
     }
   }
   pdc->suspended = GNUNET_NO;
   MHD_resume_connection (pdc->connection);
   TALER_MHD_daemon_trigger ();
 }
 
 
 /**
  * Cleanup function for the PostDonauCtx.
  *
  * @param cls closure with PostDonauCtx
  */
 static void
 post_donau_cleanup (void *cls)
 {
   struct PostDonauCtx *pdc = cls;
 
   if (pdc->get_handle)
   {
     DONAU_charity_get_cancel (pdc->get_handle);
     pdc->get_handle = NULL;
   }
   GNUNET_CONTAINER_DLL_remove (pdc_head,
                                pdc_tail,
                                pdc);
   GNUNET_free (pdc);
 }
 
 
 /**
  * Handle a POST "/donau" request.
  *
  * @param rh context of the handler
  * @param connection the MHD connection to handle
  * @param[in,out] hc context with further information about the request
  * @return MHD result code
  */
 enum MHD_Result
 TMH_private_post_donau_instance (const struct TMH_RequestHandler *rh,
                                  struct MHD_Connection *connection,
                                  struct TMH_HandlerContext *hc)
 {
   struct PostDonauCtx *pdc = hc->ctx;
 
   if (NULL == pdc)
   {
     enum GNUNET_DB_QueryStatus qs;
 
     pdc = GNUNET_new (struct PostDonauCtx);
     pdc->connection = connection;
     pdc->hc = hc;
     hc->ctx = pdc;
     hc->cc = &post_donau_cleanup;
     GNUNET_CONTAINER_DLL_insert (pdc_head,
                                  pdc_tail,
                                  pdc);
     {
       struct GNUNET_JSON_Specification spec[] = {
         GNUNET_JSON_spec_string ("donau_url",
                                  &pdc->donau_url),
         GNUNET_JSON_spec_uint64 ("charity_id",
                                  &pdc->charity_id),
         GNUNET_JSON_spec_end ()
       };
 
       if (GNUNET_OK !=
           TALER_MHD_parse_json_data (connection,
                                      hc->request_body,
                                      spec))
       {
         GNUNET_break_op (0);
         return MHD_NO;
       }
     }
     qs = TALER_MERCHANTDB_check_donau_instance (TMH_db,
                                                 &hc->instance->merchant_pub,
                                                 pdc->donau_url,
                                                 pdc->charity_id);
     switch (qs)
     {
     case GNUNET_DB_STATUS_HARD_ERROR:
     case GNUNET_DB_STATUS_SOFT_ERROR:
       GNUNET_break (0);
       pdc->http_status = MHD_HTTP_INTERNAL_SERVER_ERROR;
       return TALER_MHD_reply_with_error (
         connection,
         MHD_HTTP_INTERNAL_SERVER_ERROR,
         TALER_EC_GENERIC_DB_FETCH_FAILED,
         "check_donau_instance");
       break;
     case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
       pdc->http_status = MHD_HTTP_NO_CONTENT;
       pdc->response = MHD_create_response_from_buffer_static (0,
                                                               NULL);
       TALER_MHD_add_global_headers (pdc->response,
                                     false);
       goto respond;
     case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
       /* normal case, continue below */
       break;
     }
 
     {
       struct DONAU_CharityPrivateKeyP cp;
 
       /* Merchant private key IS our charity private key */
       cp.eddsa_priv = hc->instance->merchant_priv.eddsa_priv;
       pdc->get_handle =
         DONAU_charity_get (TMH_curl_ctx,
                            pdc->donau_url,
                            pdc->charity_id,
                            &cp,
                            &donau_charity_get_cb,
                            pdc);
     }
     if (NULL == pdc->get_handle)
     {
       GNUNET_break (0);
       GNUNET_free (pdc);
       return TALER_MHD_reply_with_error (connection,
                                          MHD_HTTP_SERVICE_UNAVAILABLE,
                                          TALER_EC_GENERIC_ALLOCATION_FAILURE,
                                          "Failed to initiate Donau lookup");
     }
     pdc->suspended = GNUNET_YES;
     MHD_suspend_connection (connection);
     return MHD_YES;
   }
 respond:
   if (NULL != pdc->response)
   {
     enum MHD_Result res;
 
     GNUNET_break (GNUNET_NO == pdc->suspended);
     res = MHD_queue_response (pdc->connection,
                               pdc->http_status,
                               pdc->response);
     MHD_destroy_response (pdc->response);
     return res;
   }
   GNUNET_break (GNUNET_SYSERR == pdc->suspended);
   return MHD_NO;
 }