1 files changed, 66 insertions, 0 deletions

diff --git a/src/service/messenger/gnunet-service-messenger_basement.c b/src/service/messenger/gnunet-service-messenger_basement.c
new file mode 100644
index 000000000..5d1d475e9
--- /dev/null
+++ b/src/service/messenger/gnunet-service-messenger_basement.c
@@ -0,0 +1,66 @@
+/*
+   This file is part of GNUnet.
+   Copyright (C) 2020--2023 GNUnet e.V.
+
+   GNUnet 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 of the License,
+   or (at your option) any later version.
+
+   GNUnet 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+   SPDX-License-Identifier: AGPL3.0-or-later
+ */
+/**
+ * @author Tobias Frisch
+ * @file src/messenger/gnunet-service-messenger_basement.c
+ * @brief GNUnet MESSENGER service
+ */
+
+#include "gnunet-service-messenger_basement.h"
+
+size_t
+count_of_tunnels (const struct GNUNET_MESSENGER_ListTunnels *tunnels)
+{
+  GNUNET_assert (tunnels);
+
+  const struct GNUNET_MESSENGER_ListTunnel *element;
+  size_t count = 0;
+
+  for (element = tunnels->head; element; element = element->next)
+    count++;
+
+  return count;
+}
+
+
+enum GNUNET_GenericReturnValue
+should_connect_tunnel_to (size_t count,
+                          size_t src,
+                          size_t dst)
+{
+  if ((src + 1) % count == dst % count)
+    return GNUNET_YES;
+
+  return GNUNET_NO;
+}
+
+
+enum GNUNET_GenericReturnValue
+required_connection_between (size_t count,
+                             size_t src,
+                             size_t dst)
+{
+  if (GNUNET_YES == should_connect_tunnel_to (count, src, dst))
+    return GNUNET_YES;
+  if (GNUNET_YES == should_connect_tunnel_to (count, dst, src))
+    return GNUNET_YES;
+
+  return GNUNET_NO;
+}