Line data    Source code

       1              : /*
       2              :    This file is part of Challenger
       3              :    Copyright (C) 2024 Taler Systems SA
       4              : 
       5              :    Challenger is free software; you can redistribute it and/or modify it under the
       6              :    terms of the GNU General Public License as published by the Free Software
       7              :    Foundation; either version 3, or (at your option) any later version.
       8              : 
       9              :    Challenger is distributed in the hope that it will be useful, but WITHOUT ANY
      10              :    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
      11              :    A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
      12              : 
      13              :    You should have received a copy of the GNU General Public License along with
      14              :    Challenger; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
      15              :  */
      16              : /**
      17              :  * @file src/challengerdb/update_client.c
      18              :  * @brief Implementation of the update_client function for Postgres
      19              :  * @author Christian Grothoff
      20              :  */
      21              : #include "platform.h"
      22              : #include <taler/taler_error_codes.h>
      23              : #include <taler/taler_dbevents.h>
      24              : #include <taler/taler_pq_lib.h>
      25              : #include "update_client.h"
      26              : #include "pg_helper.h"
      27              : 
      28              : enum GNUNET_DB_QueryStatus
      29            4 : CHALLENGERDB_update_client (struct CHALLENGERDB_PostgresContext *ctx,
      30              :                             uint64_t client_id,
      31              :                             const char *client_redirect_uri,
      32              :                             const char *client_secret,
      33              :                             bool *uri_conflict)
      34              : {
      35            4 :   struct GNUNET_PQ_QueryParam params[] = {
      36            4 :     GNUNET_PQ_query_param_uint64 (&client_id),
      37            4 :     GNUNET_PQ_query_param_string (client_redirect_uri),
      38              :     NULL == client_secret
      39            4 :     ? GNUNET_PQ_query_param_null ()
      40            4 :     : GNUNET_PQ_query_param_string (client_secret),
      41              :     GNUNET_PQ_query_param_end
      42              :   };
      43              :   bool updated;
      44              :   bool conflict;
      45            4 :   struct GNUNET_PQ_ResultSpec rs[] = {
      46            4 :     GNUNET_PQ_result_spec_bool ("updated",
      47              :                                 &updated),
      48            4 :     GNUNET_PQ_result_spec_bool ("uri_conflict",
      49              :                                 &conflict),
      50              :     GNUNET_PQ_result_spec_end
      51              :   };
      52              :   enum GNUNET_DB_QueryStatus qs;
      53              : 
      54            4 :   *uri_conflict = false;
      55              :   /* "No rows updated" has two very different causes here: the client does
      56              :      not exist, or another client already uses @a client_redirect_uri (which
      57              :      violates clients_uri_key, and GNUnet maps a unique violation to
      58              :      NO_RESULTS -- indistinguishable from "not found" at the API).  So detect
      59              :      the collision ourselves and refuse the UPDATE in that case, and report
      60              :      which of the two happened. */
      61            4 :   PREPARE (ctx,
      62              :            "update_client",
      63              :            "WITH target AS ("
      64              :            "  SELECT client_serial_id"
      65              :            "    FROM clients"
      66              :            "   WHERE client_serial_id=$1"
      67              :            "), taken AS ("
      68              :            "  SELECT client_serial_id"
      69              :            "    FROM clients"
      70              :            "   WHERE uri=$2"
      71              :            "     AND client_serial_id<>$1"
      72              :            "), upd AS ("
      73              :            "  UPDATE clients"
      74              :            "     SET uri=$2"
      75              :            "        ,client_secret=COALESCE($3,client_secret)"
      76              :            "   WHERE client_serial_id=$1"
      77              :            "     AND NOT EXISTS (SELECT 1 FROM taken)"
      78              :            "  RETURNING client_serial_id"
      79              :            ") SELECT"
      80              :            "   EXISTS (SELECT 1 FROM upd) AS updated"
      81              :            "  ,(     EXISTS (SELECT 1 FROM target)"
      82              :            "     AND EXISTS (SELECT 1 FROM taken) ) AS uri_conflict;");
      83            4 :   qs = GNUNET_PQ_eval_prepared_singleton_select (ctx->conn,
      84              :                                                  "update_client",
      85              :                                                  params,
      86              :                                                  rs);
      87            4 :   if (0 > qs)
      88            0 :     return qs;
      89            4 :   if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == qs)
      90              :   {
      91              :     /* Our SELECT always yields exactly one row, so zero rows can only be a
      92              :        unique violation on clients.uri: another transaction inserted the URI
      93              :        after our snapshot was taken. */
      94            0 :     *uri_conflict = true;
      95            0 :     return qs;
      96              :   }
      97            4 :   *uri_conflict = conflict;
      98              :   return updated
      99              :          ? GNUNET_DB_STATUS_SUCCESS_ONE_RESULT
     100            4 :          : GNUNET_DB_STATUS_SUCCESS_NO_RESULTS;
     101              : }