first rough-cut implementation of POST /reserves//status

1 files changed, 199 insertions, 0 deletions

diff --git a/src/exchange/taler-exchange-httpd_reserves_status.c b/src/exchange/taler-exchange-httpd_reserves_status.c
new file mode 100644
index 000000000..0b6ee2d30
--- /dev/null
+++ b/src/exchange/taler-exchange-httpd_reserves_status.c
@@ -0,0 +1,199 @@
+/*
+  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_status.c
+ * @brief Handle /reserves/$RESERVE_PUB STATUS 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_status.h"
+#include "taler-exchange-httpd_responses.h"
+
+
+/**
+ * Closure for #reserve_status_transaction.
+ */
+struct ReserveStatusContext
+{
+  /**
+   * Public key of the reserve the inquiry is about.
+   */
+  const struct TALER_ReservePublicKeyP *reserve_pub;
+
+  /**
+   * History of the reserve, set in the callback.
+   */
+  struct TALER_EXCHANGEDB_ReserveHistory *rh;
+
+  /**
+   * Current reserve balance.
+   */
+  struct TALER_Amount balance;
+};
+
+
+/**
+ * Send reserve status to client.
+ *
+ * @param connection connection to the client
+ * @param rh reserve history to return
+ * @return MHD result code
+ */
+static MHD_RESULT
+reply_reserve_status_success (struct MHD_Connection *connection,
+                              const struct ReserveStatusContext *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/ STATUS transaction.
+ * Execute a /reserves/ STATUS.  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 ReserveStatusContext *`
+ * @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_status_transaction (void *cls,
+                            struct MHD_Connection *connection,
+                            MHD_RESULT *mhd_ret)
+{
+  struct ReserveStatusContext *rsc = cls;
+  enum GNUNET_DB_QueryStatus qs;
+
+  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_status");
+  }
+  return qs;
+}
+
+
+MHD_RESULT
+TEH_handler_reserves_status (struct TEH_RequestContext *rc,
+                             const struct TALER_ReservePublicKeyP *reserve_pub,
+                             const json_t *root)
+{
+  struct ReserveStatusContext rsc;
+  MHD_RESULT mhd_ret;
+  struct GNUNET_TIME_Timestamp timestamp;
+  struct TALER_ReserveSignatureP reserve_sig;
+  struct GNUNET_JSON_Specification spec[] = {
+    GNUNET_JSON_spec_timestamp ("request_timestamp",
+                                &timestamp),
+    GNUNET_JSON_spec_fixed_auto ("reserve_sig",
+                                 &reserve_sig),
+    GNUNET_JSON_spec_end ()
+  };
+
+  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 */
+    }
+  }
+  if (GNUNET_OK !=
+      TALER_wallet_reserve_status_verify (timestamp,
+                                          reserve_pub,
+                                          &reserve_sig))
+  {
+    GNUNET_break_op (0);
+    return TALER_MHD_reply_with_error (rc->connection,
+                                       MHD_HTTP_FORBIDDEN,
+                                       TALER_EC_EXCHANGE_RESERVES_STATUS_BAD_SIGNATURE,
+                                       NULL);
+  }
+  rsc.rh = NULL;
+  if (GNUNET_OK !=
+      TEH_DB_run_transaction (rc->connection,
+                              "get reserve status",
+                              TEH_MT_REQUEST_OTHER,
+                              &mhd_ret,
+                              &reserve_status_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_status_success (rc->connection,
+                                          &rsc);
+  TEH_plugin->free_reserve_history (TEH_plugin->cls,
+                                    rsc.rh);
+  return mhd_ret;
+}
+
+
+/* end of taler-exchange-httpd_reserves_status.c */