code cleanup and additional error checking logic for #6124, but no actual semantic change

3 files changed, 56 insertions, 24 deletions

diff --git a/src/exchange/taler-exchange-httpd_responses.c b/src/exchange/taler-exchange-httpd_responses.c
index 0e7704e47..e2a20243d 100644
--- a/src/exchange/taler-exchange-httpd_responses.c
+++ b/src/exchange/taler-exchange-httpd_responses.c
@@ -433,10 +433,13 @@ TEH_RESPONSE_reply_coin_insufficient_funds (struct MHD_Connection *connection,
   history = TEH_RESPONSE_compile_transaction_history (coin_pub,
                                                       tl);
   if (NULL == history)
+  {
+    GNUNET_break (0);
     return TALER_MHD_reply_with_error (connection,
                                        MHD_HTTP_INTERNAL_SERVER_ERROR,
                                        TALER_EC_COIN_HISTORY_DB_ERROR_INSUFFICIENT_FUNDS,
                                        "failed to convert transaction history to JSON");
+  }
   return TALER_MHD_reply_json_pack (connection,
                                     MHD_HTTP_CONFLICT,
                                     "{s:s, s:I, s:o}",
@@ -462,10 +465,17 @@ TEH_RESPONSE_compile_reserve_history (const struct
   struct TALER_Amount deposit_total;
   struct TALER_Amount withdraw_total;
   json_t *json_history;
-  int ret;
+  enum InitAmounts
+  {
+    /** Nothing initialized */
+    IA_NONE = 0,
+    /** deposit_total initialized */
+    IA_DEPOSIT = 1,
+    /** withdraw_total initialized */
+    IA_WITHDRAW = 2
+  } init = IA_NONE;
 
   json_history = json_array ();
-  ret = 0;
   for (const struct TALER_EXCHANGEDB_ReserveHistory *pos = rh;
        NULL != pos;
        pos = pos->next)
@@ -473,8 +483,11 @@ TEH_RESPONSE_compile_reserve_history (const struct
     switch (pos->type)
     {
     case TALER_EXCHANGEDB_RO_BANK_TO_EXCHANGE:
-      if (0 == (1 & ret))
+      if (0 == (IA_DEPOSIT & init))
+      {
         deposit_total = pos->details.bank->amount;
+        init |= IA_DEPOSIT;
+      }
       else if (GNUNET_OK !=
                TALER_amount_add (&deposit_total,
                                  &deposit_total,
@@ -484,7 +497,6 @@ TEH_RESPONSE_compile_reserve_history (const struct
         json_decref (json_history);
         return NULL;
       }
-      ret |= 1;
       if (0 !=
           json_array_append_new (json_history,
                                  json_pack ("{s:s, s:o, s:s, s:o, s:o}",
@@ -514,9 +526,10 @@ TEH_RESPONSE_compile_reserve_history (const struct
         struct TALER_Amount value;
 
         value = pos->details.withdraw->amount_with_fee;
-        if (0 == (2 & ret))
+        if (0 == (IA_WITHDRAW & init))
         {
           withdraw_total = value;
+          init |= IA_WITHDRAW;
         }
         else
         {
@@ -530,7 +543,6 @@ TEH_RESPONSE_compile_reserve_history (const struct
             return NULL;
           }
         }
-        ret |= 2;
         if (0 !=
             json_array_append_new (json_history,
                                    json_pack ("{s:s, s:o, s:o, s:o, s:o, s:o}",
@@ -568,8 +580,11 @@ TEH_RESPONSE_compile_reserve_history (const struct
         struct TALER_ExchangeSignatureP sig;
 
         recoup = pos->details.recoup;
-        if (0 == (1 & ret))
+        if (0 == (IA_DEPOSIT & init))
+        {
           deposit_total = recoup->value;
+          init |= IA_DEPOSIT;
+        }
         else if (GNUNET_OK !=
                  TALER_amount_add (&deposit_total,
                                    &deposit_total,
@@ -579,7 +594,6 @@ TEH_RESPONSE_compile_reserve_history (const struct
           json_decref (json_history);
           return NULL;
         }
-        ret |= 1;
         pc.purpose.purpose = htonl (TALER_SIGNATURE_EXCHANGE_CONFIRM_RECOUP);
         pc.purpose.size = htonl (sizeof (struct TALER_RecoupConfirmationPS));
         pc.timestamp = GNUNET_TIME_absolute_hton (recoup->timestamp);
@@ -628,9 +642,10 @@ TEH_RESPONSE_compile_reserve_history (const struct
         struct TALER_Amount value;
 
         value = pos->details.closing->amount;
-        if (0 == (2 & ret))
+        if (0 == (IA_WITHDRAW & init))
         {
           withdraw_total = value;
+          init |= IA_WITHDRAW;
         }
         else
         {
@@ -644,7 +659,6 @@ TEH_RESPONSE_compile_reserve_history (const struct
             return NULL;
           }
         }
-        ret |= 2;
         rcc.purpose.purpose = htonl (TALER_SIGNATURE_EXCHANGE_RESERVE_CLOSED);
         rcc.purpose.size = htonl (sizeof (struct
                                           TALER_ReserveCloseConfirmationPS));
@@ -703,15 +717,17 @@ TEH_RESPONSE_compile_reserve_history (const struct
     }
   }
 
-  if (0 == (1 & ret))
+  if (0 == (IA_DEPOSIT & init))
   {
+    /* We should not have gotten here, without deposits no reserve
+       should exist! */
     GNUNET_break (0);
     json_decref (json_history);
     return NULL;
   }
-  if (0 == (2 & ret))
+  if (0 == (IA_WITHDRAW & init))
   {
-    /* did not encounter any withdraw operations, set to zero */
+    /* did not encounter any withdraw operations, set withdraw_total to zero */
     GNUNET_assert (GNUNET_OK ==
                    TALER_amount_get_zero (deposit_total.currency,
                                           &withdraw_total));
diff --git a/src/exchange/taler-exchange-httpd_withdraw.c b/src/exchange/taler-exchange-httpd_withdraw.c
index ddb543c84..1abf1932c 100644
--- a/src/exchange/taler-exchange-httpd_withdraw.c
+++ b/src/exchange/taler-exchange-httpd_withdraw.c
@@ -44,33 +44,40 @@
 /**
  * Send reserve status information to client with the
  * message that we have insufficient funds for the
- * requested /reserve/withdraw operation.
+ * requested withdraw operation.
  *
  * @param connection connection to the client
+ * @param ebalance expected balance based on our database
  * @param rh reserve history to return
  * @return MHD result code
  */
 static int
 reply_reserve_withdraw_insufficient_funds (struct MHD_Connection *connection,
+                                           const struct TALER_Amount *ebalance,
                                            const struct
                                            TALER_EXCHANGEDB_ReserveHistory *rh)
 {
-  json_t *json_balance;
   json_t *json_history;
   struct TALER_Amount balance;
 
   json_history = TEH_RESPONSE_compile_reserve_history (rh,
                                                        &balance);
-  if ((NULL == json_history)
-      /* Address the case where the ptr is not null, but
-       * it fails "internally" to dump as string (= corrupted).  */
-      || (0 == json_dumpb (json_history, NULL, 0, 0)))
+  if (NULL == json_history)
     return TALER_MHD_reply_with_error (connection,
                                        MHD_HTTP_INTERNAL_SERVER_ERROR,
                                        TALER_EC_WITHDRAW_HISTORY_DB_ERROR_INSUFFICIENT_FUNDS,
                                        "balance calculation failure");
-  json_balance = TALER_JSON_from_amount (&balance);
-
+  if (0 !=
+      TALER_amount_cmp (&balance,
+                        ebalance))
+  {
+    GNUNET_break (0);
+    json_decref (json_history);
+    return TALER_MHD_reply_with_error (connection,
+                                       MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                       TALER_EC_WITHDRAW_HISTORY_RESERVE_BALANCE_CORRUPT,
+                                       "internal balance inconsistency error");
+  }
   return TALER_MHD_reply_json_pack (connection,
                                     MHD_HTTP_CONFLICT,
                                     "{s:s, s:I, s:o, s:o}",
@@ -78,7 +85,8 @@ reply_reserve_withdraw_insufficient_funds (struct MHD_Connection *connection,
                                     "code",
                                     (json_int_t)
                                     TALER_EC_WITHDRAW_INSUFFICIENT_FUNDS,
-                                    "balance", json_balance,
+                                    "balance", TALER_JSON_from_amount (
+                                      &balance),
                                     "history", json_history);
 }
 
@@ -285,6 +293,7 @@ withdraw_transaction (void *cls,
       return GNUNET_DB_STATUS_HARD_ERROR;
     }
     *mhd_ret = reply_reserve_withdraw_insufficient_funds (connection,
+                                                          &r.balance,
                                                           rh);
     TEH_plugin->free_reserve_history (TEH_plugin->cls,
                                       rh);
@@ -455,7 +464,7 @@ TEH_RESERVE_handler_reserve_withdraw (const struct TEH_RequestHandler *rh,
                                   &wc.wsrd.reserve_pub.eddsa_pub))
   {
     TALER_LOG_WARNING (
-      "Client supplied invalid signature for /reserve/withdraw request\n");
+      "Client supplied invalid signature for withdraw request\n");
     GNUNET_JSON_parse_free (spec);
     TEH_KS_release (wc.key_state);
     return TALER_MHD_reply_with_error (connection,
@@ -484,7 +493,7 @@ TEH_RESERVE_handler_reserve_withdraw (const struct TEH_RequestHandler *rh,
 
   if (GNUNET_OK !=
       TEH_DB_run_transaction (connection,
-                              "run reserve withdraw",
+                              "run withdraw",
                               &mhd_ret,
                               &withdraw_transaction,
                               &wc))
diff --git a/src/include/taler_error_codes.h b/src/include/taler_error_codes.h
index f485f2da7..e6bd73647 100644
--- a/src/include/taler_error_codes.h
+++ b/src/include/taler_error_codes.h
@@ -382,6 +382,13 @@ enum TALER_ErrorCode
   TALER_EC_DENOMINATION_KEY_LOST = 1116,
 
   /**
+   * The exchange's database entry with the reserve balance summary
+   * is inconsistent with its own history of the reserve.
+   * Returned with an HTTP status of #MHD_HTTP_INTERNAL_SERVER_ERROR.
+   */
+  TALER_EC_WITHDRAW_HISTORY_RESERVE_BALANCE_CORRUPT = 1117,
+
+  /**
    * The exchange failed to obtain the transaction history of the given
    * reserve from the database. This response is provided with HTTP
    * status code MHD_HTTP_INTERNAL_SERVER_ERROR.