first rough-cut implementation of /reserves//history endpoint

src/exchange/Makefile.am

@@ -108,6 +108,7 @@ taler_exchange_httpd_SOURCES = \
   taler-exchange-httpd_refreshes_reveal.c taler-exchange-httpd_refreshes_reveal.h \
   taler-exchange-httpd_refund.c taler-exchange-httpd_refund.h \
   taler-exchange-httpd_reserves_get.c taler-exchange-httpd_reserves_get.h \
+  taler-exchange-httpd_reserves_history.c taler-exchange-httpd_reserves_history.h \
   taler-exchange-httpd_reserves_status.c taler-exchange-httpd_reserves_status.h \
   taler-exchange-httpd_responses.c taler-exchange-httpd_responses.h \
   taler-exchange-httpd_terms.c taler-exchange-httpd_terms.h \

src/exchange/taler-exchange-httpd.c

@@ -48,6 +48,7 @@
 #include "taler-exchange-httpd_refreshes_reveal.h"
 #include "taler-exchange-httpd_refund.h"
 #include "taler-exchange-httpd_reserves_get.h"
+#include "taler-exchange-httpd_reserves_history.h"
 #include "taler-exchange-httpd_reserves_status.h"
 #include "taler-exchange-httpd_terms.h"
 #include "taler-exchange-httpd_transfers_get.h"
@@ -358,6 +359,10 @@ handle_post_reserves (struct TEH_RequestContext *rc,
       .op = "status",
       .handler = &TEH_handler_reserves_status
     },
+    {
+      .op = "history",
+      .handler = &TEH_handler_reserves_history
+    },
     {
       .op = NULL,
       .handler = NULL

src/exchange/taler-exchange-httpd_reserves_history.c

@@ -0,0 +1,228 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2014-2022 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 Affero General Public License for more details.
+
+  You should have received a copy of the GNU Affero General Public License along with
+  TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file taler-exchange-httpd_reserves_history.c
+ * @brief Handle /reserves/$RESERVE_PUB/history requests
+ * @author Florian Dold
+ * @author Benedikt Mueller
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <gnunet/gnunet_util_lib.h>
+#include <jansson.h>
+#include "taler_mhd_lib.h"
+#include "taler_json_lib.h"
+#include "taler_dbevents.h"
+#include "taler-exchange-httpd_keys.h"
+#include "taler-exchange-httpd_reserves_history.h"
+#include "taler-exchange-httpd_responses.h"
+
+
+/**
+ * Closure for #reserve_history_transaction.
+ */
+struct ReserveHistoryContext
+{
+  /**
+   * Public key of the reserve the inquiry is about.
+   */
+  const struct TALER_ReservePublicKeyP *reserve_pub;
+
+  /**
+   * Timestamp of the request.
+   */
+  struct GNUNET_TIME_Timestamp timestamp;
+
+  /**
+   * Client signature approving the request.
+   */
+  struct TALER_ReserveSignatureP reserve_sig;
+
+  /**
+   * History of the reserve, set in the callback.
+   */
+  struct TALER_EXCHANGEDB_ReserveHistory *rh;
+
+  /**
+   * Global fees applying to the request.
+   */
+  const struct TEH_GlobalFee *gf;
+
+  /**
+   * Current reserve balance.
+   */
+  struct TALER_Amount balance;
+};
+
+
+/**
+ * Send reserve history to client.
+ *
+ * @param connection connection to the client
+ * @param rh reserve history to return
+ * @return MHD result code
+ */
+static MHD_RESULT
+reply_reserve_history_success (struct MHD_Connection *connection,
+                               const struct ReserveHistoryContext *rhc)
+{
+  const struct TALER_EXCHANGEDB_ReserveHistory *rh = rhc->rh;
+  json_t *json_history;
+
+  json_history = TEH_RESPONSE_compile_reserve_history (rh);
+  if (NULL == json_history)
+    return TALER_MHD_reply_with_error (connection,
+                                       MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                       TALER_EC_GENERIC_JSON_ALLOCATION_FAILURE,
+                                       NULL);
+  return TALER_MHD_REPLY_JSON_PACK (
+    connection,
+    MHD_HTTP_OK,
+    TALER_JSON_pack_amount ("balance",
+                            &rhc->balance),
+    GNUNET_JSON_pack_array_steal ("history",
+                                  json_history));
+}
+
+
+/**
+ * Function implementing /reserves/$RID/history transaction.  Given the public
+ * key of a reserve, return the associated transaction history.  Runs the
+ * transaction logic; IF it returns a non-error code, the transaction logic
+ * MUST NOT queue a MHD response.  IF it returns an hard error, the
+ * transaction logic MUST queue a MHD response and set @a mhd_ret.  IF it
+ * returns the soft error code, the function MAY be called again to retry and
+ * MUST not queue a MHD response.
+ *
+ * @param cls a `struct ReserveHistoryContext *`
+ * @param connection MHD request which triggered the transaction
+ * @param[out] mhd_ret set to MHD response status for @a connection,
+ *             if transaction failed (!); unused
+ * @return transaction status
+ */
+static enum GNUNET_DB_QueryStatus
+reserve_history_transaction (void *cls,
+                             struct MHD_Connection *connection,
+                             MHD_RESULT *mhd_ret)
+{
+  struct ReserveHistoryContext *rsc = cls;
+  enum GNUNET_DB_QueryStatus qs;
+
+  // FIXME: first deduct rsc->gf->fees.history from balance!
+  // FIXME: pass rsc.gf->history_expiration?
+  qs = TEH_plugin->get_reserve_history (TEH_plugin->cls,
+                                        rsc->reserve_pub,
+                                        &rsc->balance,
+                                        &rsc->rh);
+  if (GNUNET_DB_STATUS_HARD_ERROR == qs)
+  {
+    GNUNET_break (0);
+    *mhd_ret
+      = TALER_MHD_reply_with_error (connection,
+                                    MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                    TALER_EC_GENERIC_DB_FETCH_FAILED,
+                                    "get_reserve_history");
+  }
+  return qs;
+}
+
+
+MHD_RESULT
+TEH_handler_reserves_history (struct TEH_RequestContext *rc,
+                              const struct TALER_ReservePublicKeyP *reserve_pub,
+                              const json_t *root)
+{
+  struct ReserveHistoryContext rsc;
+  MHD_RESULT mhd_ret;
+  struct GNUNET_JSON_Specification spec[] = {
+    GNUNET_JSON_spec_timestamp ("request_timestamp",
+                                &rsc.timestamp),
+    GNUNET_JSON_spec_fixed_auto ("reserve_sig",
+                                 &rsc.reserve_sig),
+    GNUNET_JSON_spec_end ()
+  };
+  struct GNUNET_TIME_Timestamp now;
+
+  rsc.reserve_pub = reserve_pub;
+  {
+    enum GNUNET_GenericReturnValue res;
+
+    res = TALER_MHD_parse_json_data (rc->connection,
+                                     root,
+                                     spec);
+    if (GNUNET_SYSERR == res)
+    {
+      GNUNET_break (0);
+      return MHD_NO; /* hard failure */
+    }
+    if (GNUNET_NO == res)
+    {
+      GNUNET_break_op (0);
+      return MHD_YES; /* failure */
+    }
+  }
+  now = GNUNET_TIME_timestamp_get ();
+  /* FIXME: check that 'timestamp' is close to 'now' */
+
+  rsc.gf = TEH_keys_global_fee_by_time (TEH_keys_get_state (),
+                                        rsc.timestamp);
+  if (NULL == rsc.gf)
+  {
+    GNUNET_break_op (0);
+    return TALER_MHD_reply_with_error (rc->connection,
+                                       MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                       TALER_EC_EXCHANGE_GENERIC_BAD_CONFIGURATION,
+                                       NULL);
+  }
+  if (GNUNET_OK !=
+      TALER_wallet_reserve_history_verify (rsc.timestamp,
+                                           &rsc.gf->fees.history,
+                                           reserve_pub,
+                                           &rsc.reserve_sig))
+  {
+    GNUNET_break_op (0);
+    return TALER_MHD_reply_with_error (rc->connection,
+                                       MHD_HTTP_FORBIDDEN,
+                                       TALER_EC_EXCHANGE_RESERVES_HISTORY_BAD_SIGNATURE,
+                                       NULL);
+  }
+  rsc.rh = NULL;
+  if (GNUNET_OK !=
+      TEH_DB_run_transaction (rc->connection,
+                              "get reserve history",
+                              TEH_MT_REQUEST_OTHER,
+                              &mhd_ret,
+                              &reserve_history_transaction,
+                              &rsc))
+  {
+    return mhd_ret;
+  }
+  if (NULL == rsc.rh)
+  {
+    return TALER_MHD_reply_with_error (rc->connection,
+                                       MHD_HTTP_NOT_FOUND,
+                                       TALER_EC_EXCHANGE_RESERVES_STATUS_UNKNOWN,
+                                       NULL);
+  }
+  mhd_ret = reply_reserve_history_success (rc->connection,
+                                           &rsc);
+  TEH_plugin->free_reserve_history (TEH_plugin->cls,
+                                    rsc.rh);
+  return mhd_ret;
+}
+
+
+/* end of taler-exchange-httpd_reserves_history.c */

src/exchange/taler-exchange-httpd_reserves_history.h

@@ -0,0 +1,43 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2014-2020 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 Affero General Public License for more details.
+
+  You should have received a copy of the GNU Affero General Public License along with
+  TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file taler-exchange-httpd_reserves_history.h
+ * @brief Handle /reserves/$RESERVE_PUB HISTORY requests
+ * @author Florian Dold
+ * @author Benedikt Mueller
+ * @author Christian Grothoff
+ */
+#ifndef TALER_EXCHANGE_HTTPD_RESERVES_HISTORY_H
+#define TALER_EXCHANGE_HTTPD_RESERVES_HISTORY_H
+
+#include <microhttpd.h>
+#include "taler-exchange-httpd.h"
+
+
+/**
+ * Handle a POST "/reserves/$RID/history" request.
+ *
+ * @param rc request context
+ * @param reserve_pub public key of the reserve
+ * @param root uploaded body from the client
+ * @return MHD result code
+ */
+MHD_RESULT
+TEH_handler_reserves_history (struct TEH_RequestContext *rc,
+                              const struct TALER_ReservePublicKeyP *reserve_pub,
+                              const json_t *root);
+
+#endif

src/exchangedb/plugin_exchangedb_postgres.c

@@ -5544,6 +5544,101 @@ postgres_get_reserve_history (void *cls,
 }
 
 
+/**
+ * Get a truncated transaction history associated with the specified
+ * reserve.
+ *
+ * @param cls the `struct PostgresClosure` with the plugin-specific state
+ * @param reserve_pub public key of the reserve
+ * @param[out] balance set to the reserve balance
+ * @param[out] rhp set to known transaction history (NULL if reserve is unknown)
+ * @return transaction status
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_get_reserve_status (void *cls,
+                             const struct TALER_ReservePublicKeyP *reserve_pub,
+                             struct TALER_Amount *balance,
+                             struct TALER_EXCHANGEDB_ReserveHistory **rhp)
+{
+  struct PostgresClosure *pg = cls;
+  struct ReserveHistoryContext rhc;
+  struct
+  {
+    /**
+     * Name of the prepared statement to run.
+     */
+    const char *statement;
+    /**
+     * Function to use to process the results.
+     */
+    GNUNET_PQ_PostgresResultHandler cb;
+  } work[] = {
+    /** #TALER_EXCHANGEDB_RO_BANK_TO_EXCHANGE */
+    { "reserves_in_get_transactions",
+      add_bank_to_exchange },
+    /** #TALER_EXCHANGEDB_RO_WITHDRAW_COIN */
+    { "get_reserves_out",
+      &add_withdraw_coin },
+    /** #TALER_EXCHANGEDB_RO_RECOUP_COIN */
+    { "recoup_by_reserve",
+      &add_recoup },
+    /** #TALER_EXCHANGEDB_RO_EXCHANGE_TO_BANK */
+    { "close_by_reserve",
+      &add_exchange_to_bank },
+    /* List terminator */
+    { NULL,
+      NULL }
+  };
+  enum GNUNET_DB_QueryStatus qs;
+  struct GNUNET_PQ_QueryParam params[] = {
+    GNUNET_PQ_query_param_auto_from_type (reserve_pub),
+    GNUNET_PQ_query_param_end
+  };
+
+  rhc.reserve_pub = reserve_pub;
+  rhc.rh = NULL;
+  rhc.rh_tail = NULL;
+  rhc.pg = pg;
+  rhc.status = GNUNET_OK;
+  GNUNET_assert (GNUNET_OK ==
+                 TALER_amount_set_zero (pg->currency,
+                                        &rhc.balance_in));
+  GNUNET_assert (GNUNET_OK ==
+                 TALER_amount_set_zero (pg->currency,
+                                        &rhc.balance_out));
+  qs = GNUNET_DB_STATUS_SUCCESS_NO_RESULTS; /* make static analysis happy */
+  for (unsigned int i = 0; NULL != work[i].cb; i++)
+  {
+    qs = GNUNET_PQ_eval_prepared_multi_select (pg->conn,
+                                               work[i].statement,
+                                               params,
+                                               work[i].cb,
+                                               &rhc);
+    if ( (0 > qs) ||
+         (GNUNET_OK != rhc.status) )
+      break;
+  }
+  if ( (qs < 0) ||
+       (rhc.status != GNUNET_OK) )
+  {
+    common_free_reserve_history (cls,
+                                 rhc.rh);
+    rhc.rh = NULL;
+    if (qs >= 0)
+    {
+      /* status == SYSERR is a very hard error... */
+      qs = GNUNET_DB_STATUS_HARD_ERROR;
+    }
+  }
+  *rhp = rhc.rh;
+  GNUNET_assert (0 <=
+                 TALER_amount_subtract (balance,
+                                        &rhc.balance_in,
+                                        &rhc.balance_out));
+  return qs;
+}
+
+
 /**
  * Get the balance of the specified reserve.
  *
@@ -12547,6 +12642,7 @@ libtaler_plugin_exchangedb_postgres_init (void *cls)
   plugin->do_recoup_refresh = &postgres_do_recoup_refresh;
   plugin->get_reserve_balance = &postgres_get_reserve_balance;
   plugin->get_reserve_history = &postgres_get_reserve_history;
+  plugin->get_reserve_status = &postgres_get_reserve_status;
   plugin->free_reserve_history = &common_free_reserve_history;
   plugin->count_known_coins = &postgres_count_known_coins;
   plugin->ensure_coin_known = &postgres_ensure_coin_known;

src/include/taler_exchangedb_plugin.h

@@ -2846,6 +2846,23 @@ struct TALER_EXCHANGEDB_Plugin
                          struct TALER_EXCHANGEDB_ReserveHistory **rhp);
 
 
+  /**
+   * Get truncated transaction history associated with the specified
+   * reserve.
+   *
+   * @param cls the @e cls of this struct with the plugin-specific state
+   * @param reserve_pub public key of the reserve
+   * @param[out] balance set to the reserve balance
+   * @param[out] rhp set to known transaction history (NULL if reserve is unknown)
+   * @return transaction status
+   */
+  enum GNUNET_DB_QueryStatus
+  (*get_reserve_status)(void *cls,
+                        const struct TALER_ReservePublicKeyP *reserve_pub,
+                        struct TALER_Amount *balance,
+                        struct TALER_EXCHANGEDB_ReserveHistory **rhp);
+
+
   /**
    * The current reserve balance of the specified reserve.
    *