move fake bank implementation to new library to re-use the code in upcoming testcases in preparation of fixing #4399

3 files changed, 549 insertions, 0 deletions

diff --git a/src/bank-lib/Makefile.am b/src/bank-lib/Makefile.am
index dc52f8e0..e833c533 100644
--- a/src/bank-lib/Makefile.am
+++ b/src/bank-lib/Makefile.am
@@ -9,6 +9,9 @@ endif
 lib_LTLIBRARIES = \
   libtalerbank.la
 
+noinst_LTLIBRARIES = \
+  libfakebank.la
+
 libtalerbank_la_LDFLAGS = \
   -version-info 0:0:0 \
   -no-undefined
@@ -24,6 +27,17 @@ libtalerbank_la_LIBADD = \
   -ljansson \
   $(XLIB)
 
+libfakebank_la_SOURCES = \
+  fakebank.c
+
+libfakebank_la_LIBADD = \
+  $(top_builddir)/src/json/libtalerjson.la \
+  -lgnunetjson \
+  -lgnunetutil \
+  -ljansson \
+  $(XLIB)
+
+
 if HAVE_LIBCURL
 libtalerbank_la_LIBADD += -lcurl
 else
diff --git a/src/bank-lib/fakebank.c b/src/bank-lib/fakebank.c
new file mode 100644
index 00000000..8598e007
--- /dev/null
+++ b/src/bank-lib/fakebank.c
@@ -0,0 +1,441 @@
+/*
+  This file is part of TALER
+  (C) 2016 Inria and GNUnet e.V.
+
+  TALER is free software; you can redistribute it and/or modify it under the
+  terms of the GNU 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, If not, see <http://www.gnu.org/licenses/>
+*/
+
+/**
+ * @file bank-lib/fakebank.c
+ * @brief library that fakes being a Taler bank for testcases
+ * @author Christian Grothoff <christian@grothoff.org>
+ */
+
+#include "platform.h"
+#include "fakebank.h"
+
+/**
+ * Maximum POST request size (for /admin/add/incoming)
+ */
+#define REQUEST_BUFFER_MAX (4*1024)
+
+
+
+/**
+ * Details about a transcation we (as the simulated bank) received.
+ */
+struct Transaction
+{
+
+  /**
+   * We store transactions in a DLL.
+   */
+  struct Transaction *next;
+
+  /**
+   * We store transactions in a DLL.
+   */
+  struct Transaction *prev;
+
+  /**
+   * Amount to be transferred.
+   */
+  struct TALER_Amount amount;
+
+  /**
+   * Account to debit.
+   */
+  uint64_t debit_account;
+
+  /**
+   * Account to credit.
+   */
+  uint64_t credit_account;
+
+  /**
+   * Subject of the transfer.
+   */
+  struct TALER_WireTransferIdentifierRawP wtid;
+};
+
+
+/**
+ * Handle for the fake bank.
+ */
+struct FAKEBANK_Handle
+{
+  /**
+   * We store transactions in a DLL.
+   */
+  struct Transaction *transactions_head;
+
+  /**
+   * We store transactions in a DLL.
+   */
+  struct Transaction *transactions_tail;
+
+  /**
+   * HTTP server we run to pretend to be the "test" bank.
+   */
+  struct MHD_Daemon *mhd_bank;
+
+  /**
+   * Task running HTTP server for the "test" bank.
+   */
+  struct GNUNET_SCHEDULER_Task *mhd_task;
+};
+
+
+/**
+ * Check that the @a want_amount was transferred from
+ * the @a want_debit to the @a want_credit account.  If
+ * so, set the @a wtid to the transfer identifier.
+ * If not, return #GNUNET_SYSERR.
+ *
+ * @param h bank instance
+ * @param want_amount transfer amount desired
+ * @param want_debit account that should have been debited
+ * @param want_debit account that should have been credited
+ * @param[out] wtid set to the wire transfer identifier
+ * @return #GNUNET_OK on success
+ */
+int
+FAKEBANK_check (struct FAKEBANK_Handle *h,
+                const struct TALER_Amount *want_amount,
+                uint64_t want_debit,
+                uint64_t want_credit,
+                struct TALER_WireTransferIdentifierRawP *wtid)
+{
+  struct Transaction *t;
+
+  for (t = h->transactions_head; NULL != t; t = t->next)
+  {
+    if ( (want_debit == t->debit_account) &&
+         (want_credit == t->credit_account) &&
+         (0 == TALER_amount_cmp (want_amount,
+                                 &t->amount)) )
+    {
+      GNUNET_CONTAINER_DLL_remove (h->transactions_head,
+                                   h->transactions_tail,
+                                   t);
+      *wtid = t->wtid;
+      GNUNET_free (t);
+      return GNUNET_OK;
+    }
+  }
+  fprintf (stderr,
+           "Did not find matching transaction!\nI have:\n");
+  for (t = h->transactions_head; NULL != t; t = t->next)
+  {
+    char *s;
+
+    s = TALER_amount_to_string (&t->amount);
+    fprintf (stderr,
+             "%llu -> %llu (%s)\n",
+             (unsigned long long) t->debit_account,
+             (unsigned long long) t->credit_account,
+             s);
+    GNUNET_free (s);
+  }
+  return GNUNET_SYSERR;
+}
+
+
+/**
+ * Check that no wire transfers were ordered (or at least none
+ * that have not been taken care of via #FAKEBANK_check()).
+ * If any transactions are onrecord, return #GNUNET_SYSERR.
+ *
+ * @param h bank instance
+ * @return #GNUNET_OK on success
+ */
+int
+FAKEBANK_check_empty (struct FAKEBANK_Handle *h)
+{
+  struct Transaction *t;
+
+  if (NULL == h->transactions_head)
+    return GNUNET_OK;
+
+  fprintf (stderr,
+           "Expected empty transaction set, but I have:\n");
+  for (t = h->transactions_head; NULL != t; t = t->next)
+  {
+    char *s;
+
+    s = TALER_amount_to_string (&t->amount);
+    fprintf (stderr,
+             "%llu -> %llu (%s)\n",
+             (unsigned long long) t->debit_account,
+             (unsigned long long) t->credit_account,
+             s);
+    GNUNET_free (s);
+  }
+  return GNUNET_SYSERR;
+}
+
+
+/**
+ * Stop running the fake bank.
+ *
+ * @param h bank to stop
+ */
+void
+FAKEBANK_stop (struct FAKEBANK_Handle *h)
+{
+  if (NULL != h->mhd_task)
+  {
+    GNUNET_SCHEDULER_cancel (h->mhd_task);
+    h->mhd_task = NULL;
+  }
+  if (NULL != h->mhd_bank)
+  {
+    MHD_stop_daemon (h->mhd_bank);
+    h->mhd_bank = NULL;
+  }
+  GNUNET_free (h);
+}
+
+
+/**
+ * Function called whenever MHD is done with a request.  If the
+ * request was a POST, we may have stored a `struct Buffer *` in the
+ * @a con_cls that might still need to be cleaned up.  Call the
+ * respective function to free the memory.
+ *
+ * @param cls client-defined closure
+ * @param connection connection handle
+ * @param con_cls value as set by the last call to
+ *        the #MHD_AccessHandlerCallback
+ * @param toe reason for request termination
+ * @see #MHD_OPTION_NOTIFY_COMPLETED
+ * @ingroup request
+ */
+static void
+handle_mhd_completion_callback (void *cls,
+                                struct MHD_Connection *connection,
+                                void **con_cls,
+                                enum MHD_RequestTerminationCode toe)
+{
+  /*  struct FAKEBANK_Handle *h = cls; */
+
+  GNUNET_JSON_post_parser_cleanup (*con_cls);
+  *con_cls = NULL;
+}
+
+
+/**
+ * Handle incoming HTTP request.
+ *
+ * @param cls closure for MHD daemon (unused)
+ * @param connection the connection
+ * @param url the requested url
+ * @param method the method (POST, GET, ...)
+ * @param version HTTP version (ignored)
+ * @param upload_data request data
+ * @param upload_data_size size of @a upload_data in bytes
+ * @param con_cls closure for request (a `struct Buffer *`)
+ * @return MHD result code
+ */
+static int
+handle_mhd_request (void *cls,
+                    struct MHD_Connection *connection,
+                    const char *url,
+                    const char *method,
+                    const char *version,
+                    const char *upload_data,
+                    size_t *upload_data_size,
+                    void **con_cls)
+{
+  struct FAKEBANK_Handle *h = cls;
+  enum GNUNET_JSON_PostResult pr;
+  json_t *json;
+  struct Transaction *t;
+  struct MHD_Response *resp;
+  int ret;
+
+  if (0 != strcasecmp (url,
+                       "/admin/add/incoming"))
+  {
+    /* Unexpected URI path, just close the connection. */
+    /* we're rather impolite here, but it's a testcase. */
+    GNUNET_break_op (0);
+    return MHD_NO;
+  }
+  pr = GNUNET_JSON_post_parser (REQUEST_BUFFER_MAX,
+                                con_cls,
+                                upload_data,
+                                upload_data_size,
+                                &json);
+  switch (pr)
+  {
+  case GNUNET_JSON_PR_OUT_OF_MEMORY:
+    GNUNET_break (0);
+    return MHD_NO;
+  case GNUNET_JSON_PR_CONTINUE:
+    return MHD_YES;
+  case GNUNET_JSON_PR_REQUEST_TOO_LARGE:
+    GNUNET_break (0);
+    return MHD_NO;
+  case GNUNET_JSON_PR_JSON_INVALID:
+    GNUNET_break (0);
+    return MHD_NO;
+  case GNUNET_JSON_PR_SUCCESS:
+    break;
+  }
+  t = GNUNET_new (struct Transaction);
+  {
+    struct GNUNET_JSON_Specification spec[] = {
+      GNUNET_JSON_spec_fixed_auto ("wtid", &t->wtid),
+      GNUNET_JSON_spec_uint64 ("debit_account", &t->debit_account),
+      GNUNET_JSON_spec_uint64 ("credit_account", &t->credit_account),
+      TALER_JSON_spec_amount ("amount", &t->amount),
+      GNUNET_JSON_spec_end ()
+    };
+    if (GNUNET_OK !=
+        GNUNET_JSON_parse (json,
+                           spec,
+                           NULL, NULL))
+    {
+      GNUNET_break (0);
+      json_decref (json);
+      return MHD_NO;
+    }
+    GNUNET_CONTAINER_DLL_insert (h->transactions_head,
+                                 h->transactions_tail,
+                                 t);
+  }
+  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+              "Receiving incoming wire transfer: %llu->%llu\n",
+              (unsigned long long) t->debit_account,
+              (unsigned long long) t->credit_account);
+  json_decref (json);
+  resp = MHD_create_response_from_buffer (0, "", MHD_RESPMEM_PERSISTENT);
+  ret = MHD_queue_response (connection,
+                            MHD_HTTP_OK,
+                            resp);
+  MHD_destroy_response (resp);
+  return ret;
+}
+
+
+/**
+ * Task run whenever HTTP server operations are pending.
+ *
+ * @param cls the `struct FAKEBANK_Handle`
+ */
+static void
+run_mhd (void *cls);
+
+
+/**
+ * Schedule MHD.  This function should be called initially when an
+ * MHD is first getting its client socket, and will then automatically
+ * always be called later whenever there is work to be done.
+ */
+static void
+schedule_httpd (struct FAKEBANK_Handle *h)
+{
+  fd_set rs;
+  fd_set ws;
+  fd_set es;
+  struct GNUNET_NETWORK_FDSet *wrs;
+  struct GNUNET_NETWORK_FDSet *wws;
+  int max;
+  int haveto;
+  MHD_UNSIGNED_LONG_LONG timeout;
+  struct GNUNET_TIME_Relative tv;
+
+  FD_ZERO (&rs);
+  FD_ZERO (&ws);
+  FD_ZERO (&es);
+  max = -1;
+  if (MHD_YES != MHD_get_fdset (h->mhd_bank, &rs, &ws, &es, &max))
+  {
+    GNUNET_assert (0);
+    return;
+  }
+  haveto = MHD_get_timeout (h->mhd_bank, &timeout);
+  if (MHD_YES == haveto)
+    tv.rel_value_us = (uint64_t) timeout * 1000LL;
+  else
+    tv = GNUNET_TIME_UNIT_FOREVER_REL;
+  if (-1 != max)
+  {
+    wrs = GNUNET_NETWORK_fdset_create ();
+    wws = GNUNET_NETWORK_fdset_create ();
+    GNUNET_NETWORK_fdset_copy_native (wrs, &rs, max + 1);
+    GNUNET_NETWORK_fdset_copy_native (wws, &ws, max + 1);
+  }
+  else
+  {
+    wrs = NULL;
+    wws = NULL;
+  }
+  if (NULL != h->mhd_task)
+    GNUNET_SCHEDULER_cancel (h->mhd_task);
+  h->mhd_task =
+    GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_DEFAULT,
+                                 tv,
+                                 wrs,
+                                 wws,
+                                 &run_mhd, h);
+  if (NULL != wrs)
+    GNUNET_NETWORK_fdset_destroy (wrs);
+  if (NULL != wws)
+    GNUNET_NETWORK_fdset_destroy (wws);
+}
+
+
+/**
+ * Task run whenever HTTP server operations are pending.
+ *
+ * @param cls the `struct FAKEBANK_Handle`
+ */
+static void
+run_mhd (void *cls)
+{
+  struct FAKEBANK_Handle *h = cls;
+
+  h->mhd_task = NULL;
+  MHD_run (h->mhd_bank);
+  schedule_httpd (h);
+}
+
+
+/**
+ * Start the fake bank.
+ *
+ * @param port port to listen to
+ * @return NULL on error
+ */
+struct FAKEBANK_Handle *
+FAKEBANK_start (uint16_t port)
+{
+  struct FAKEBANK_Handle *h;
+
+  h = GNUNET_new (struct FAKEBANK_Handle);
+  h->mhd_bank = MHD_start_daemon (MHD_USE_DEBUG,
+                                  port,
+                                  NULL, NULL,
+                                  &handle_mhd_request, h,
+                                  MHD_OPTION_NOTIFY_COMPLETED,
+                                  &handle_mhd_completion_callback, h,
+                                  MHD_OPTION_END);
+  if (NULL == h->mhd_bank)
+  {
+    GNUNET_free (h);
+    return NULL;
+  }
+  schedule_httpd (h);
+  return h;
+}
diff --git a/src/bank-lib/fakebank.h b/src/bank-lib/fakebank.h
new file mode 100644
index 00000000..5a4c13cd
--- /dev/null
+++ b/src/bank-lib/fakebank.h
@@ -0,0 +1,94 @@
+/*
+  This file is part of TALER
+  (C) 2016 Inria and GNUnet e.V.
+
+  TALER is free software; you can redistribute it and/or modify it under the
+  terms of the GNU 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, If not, see <http://www.gnu.org/licenses/>
+*/
+
+/**
+ * @file bank-lib/fakebank.h
+ * @brief API for a library that fakes being a Taler bank
+ * @author Christian Grothoff <christian@grothoff.org>
+ */
+#ifndef FAKEBANK_H
+#define FAKEBANK_H
+
+#include "taler_util.h"
+#include <gnunet/gnunet_json_lib.h>
+#include "taler_json_lib.h"
+#include <microhttpd.h>
+
+/**
+ * Handle for the fake bank.
+ */
+struct FAKEBANK_Handle;
+
+
+/**
+ * Start the fake bank.  The fake bank will, like the normal bank,
+ * listen for requests for /admin/add/incoming. However, instead of
+ * executing or storing those requests, it will simply allow querying
+ * whether such a request has been made via #FAKEBANK_check().
+ *
+ * This is useful for writing testcases to check whether the exchange
+ * would have issued the correct wire transfer orders.
+ *
+ * @param port port to listen to
+ * @return NULL on error
+ */
+struct FAKEBANK_Handle *
+FAKEBANK_start (uint16_t port);
+
+
+/**
+ * Check that no wire transfers were ordered (or at least none
+ * that have not been taken care of via #FAKEBANK_check()).
+ * If any transactions are onrecord, return #GNUNET_SYSERR.
+ *
+ * @param h bank instance
+ * @return #GNUNET_OK on success
+ */
+int
+FAKEBANK_check_empty (struct FAKEBANK_Handle *h);
+
+
+/**
+ * Check that the @a want_amount was transferred from the @a
+ * want_debit to the @a want_credit account.  If so, set the @a wtid
+ * to the transfer identifier and remove the transaction from the
+ * list.  If the transaction was not recorded, return #GNUNET_SYSERR.
+ *
+ * @param h bank instance
+ * @param want_amount transfer amount desired
+ * @param want_debit account that should have been debited
+ * @param want_debit account that should have been credited
+ * @param[out] wtid set to the wire transfer identifier
+ * @return #GNUNET_OK on success
+ */
+int
+FAKEBANK_check (struct FAKEBANK_Handle *h,
+                const struct TALER_Amount *want_amount,
+                uint64_t want_debit,
+                uint64_t want_credit,
+                struct TALER_WireTransferIdentifierRawP *wtid);
+
+
+/**
+ * Stop running the fake bank.
+ *
+ * @param h bank to stop
+ */
+void
+FAKEBANK_stop (struct FAKEBANK_Handle *h);
+
+
+#endif