1 files changed, 222 insertions, 0 deletions

diff --git a/src/contrib/service/consensus/plugin_block_consensus.c b/src/contrib/service/consensus/plugin_block_consensus.c
new file mode 100644
index 000000000..241d8fc7b
--- /dev/null
+++ b/src/contrib/service/consensus/plugin_block_consensus.c
@@ -0,0 +1,222 @@
+/*
+     This file is part of GNUnet
+     Copyright (C) 2017, 2021 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
+ */
+
+/**
+ * @file consensus/plugin_block_consensus.c
+ * @brief consensus block, either nested block or marker
+ * @author Christian Grothoff
+ */
+
+#include "platform.h"
+#include "consensus_protocol.h"
+#include "gnunet_block_plugin.h"
+#include "gnunet_block_group_lib.h"
+
+
+/**
+ * Our closure.
+ */
+struct BlockContext
+{
+  /**
+   * Configuration to use.
+   */
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Lazily initialized block context.
+   */
+  struct GNUNET_BLOCK_Context *bc;
+};
+
+
+
+/**
+ * Function called to validate a query.
+ *
+ * @param cls closure
+ * @param type block type
+ * @param query original query (hash)
+ * @param xquery extrended query data (can be NULL, depending on type)
+ * @param xquery_size number of bytes in @a xquery
+ * @return #GNUNET_OK if the query is fine, #GNUNET_NO if not
+ */
+static enum GNUNET_GenericReturnValue
+block_plugin_consensus_check_query (void *cls,
+                                    enum GNUNET_BLOCK_Type type,
+                                    const struct GNUNET_HashCode *query,
+                                    const void *xquery,
+                                    size_t xquery_size)
+{
+  /* consensus does not use queries/DHT */
+  GNUNET_break (0);
+  return GNUNET_SYSERR;
+}
+
+
+/**
+ * Function called to validate a block for storage.
+ *
+ * @param cls closure
+ * @param type block type
+ * @param block block data to validate
+ * @param block_size number of bytes in @a block
+ * @return #GNUNET_OK if the block is fine, #GNUNET_NO if not
+ */
+static enum GNUNET_GenericReturnValue
+block_plugin_consensus_check_block (void *cls,
+                                    enum GNUNET_BLOCK_Type type,
+                                    const void *block,
+                                    size_t block_size)
+{
+  struct BlockContext *ctx = cls;
+  const struct ConsensusElement *ce = block;
+
+  if (block_size < sizeof(*ce))
+  {
+    GNUNET_break_op (0);
+    return GNUNET_NO;
+  }
+  if ( (0 != ce->marker) ||
+       (0 == ce->payload_type) )
+    return GNUNET_OK;
+  if (NULL == ctx->bc)
+    ctx->bc = GNUNET_BLOCK_context_create (ctx->cfg);
+  return GNUNET_BLOCK_check_block (ctx->bc,
+                                   ntohl (ce->payload_type),
+                                   &ce[1],
+                                   block_size - sizeof(*ce));
+}
+
+
+/**
+ * Function called to validate a reply to a request.  Note that it is assumed
+ * that the reply has already been matched to the key (and signatures checked)
+ * as it would be done with the GetKeyFunction and the
+ * BlockEvaluationFunction.
+ *
+ * @param cls closure
+ * @param type block type
+ * @param group which block group to use for evaluation
+ * @param query original query (hash)
+ * @param xquery extrended query data (can be NULL, depending on type)
+ * @param xquery_size number of bytes in @a xquery
+ * @param reply_block response to validate
+ * @param reply_block_size number of bytes in @a reply_block
+ * @return characterization of result
+ */
+static enum GNUNET_BLOCK_ReplyEvaluationResult
+block_plugin_consensus_check_reply (
+  void *cls,
+  enum GNUNET_BLOCK_Type type,
+  struct GNUNET_BLOCK_Group *group,
+  const struct GNUNET_HashCode *query,
+  const void *xquery,
+  size_t xquery_size,
+  const void *reply_block,
+  size_t reply_block_size)
+{
+  struct BlockContext *ctx = cls;
+  const struct ConsensusElement *ce = reply_block;
+
+  GNUNET_assert (reply_block_size >= sizeof(struct ConsensusElement));
+  if ( (0 != ce->marker) ||
+       (0 == ce->payload_type) )
+    return GNUNET_BLOCK_REPLY_OK_MORE;
+  if (NULL == ctx->bc)
+    ctx->bc = GNUNET_BLOCK_context_create (ctx->cfg);
+  return GNUNET_BLOCK_check_reply (ctx->bc,
+                                   ntohl (ce->payload_type),
+                                   group,
+                                   query,
+                                   xquery,
+                                   xquery_size,
+                                   &ce[1],
+                                   reply_block_size - sizeof(*ce));
+}
+
+
+/**
+ * Function called to obtain the key for a block.
+ *
+ * @param cls closure
+ * @param type block type
+ * @param block block to get the key for
+ * @param block_size number of bytes in block
+ * @param key set to the key (query) for the given block
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if type not supported
+ *         (or if extracting a key from a block of this type does not work)
+ */
+static enum GNUNET_GenericReturnValue
+block_plugin_consensus_get_key (void *cls,
+                                enum GNUNET_BLOCK_Type type,
+                                const void *block,
+                                size_t block_size,
+                                struct GNUNET_HashCode *key)
+{
+  return GNUNET_SYSERR;
+}
+
+
+/**
+ * Entry point for the plugin.
+ */
+void *
+libgnunet_plugin_block_consensus_init (void *cls)
+{
+  static const enum GNUNET_BLOCK_Type types[] = {
+    GNUNET_BLOCK_TYPE_CONSENSUS_ELEMENT,
+    GNUNET_BLOCK_TYPE_ANY       /* end of list */
+  };
+  const struct GNUNET_CONFIGURATION_Handle *cfg = cls;
+  struct BlockContext *ctx;
+  struct GNUNET_BLOCK_PluginFunctions *api;
+
+  ctx = GNUNET_new (struct BlockContext);
+  ctx->cfg = cfg;
+  api = GNUNET_new (struct GNUNET_BLOCK_PluginFunctions);
+  api->cls = ctx;
+  api->get_key = &block_plugin_consensus_get_key;
+  api->check_query = &block_plugin_consensus_check_query;
+  api->check_block = &block_plugin_consensus_check_block;
+  api->check_reply = &block_plugin_consensus_check_reply;
+  api->types = types;
+  return api;
+}
+
+
+/**
+ * Exit point from the plugin.
+ */
+void *
+libgnunet_plugin_block_consensus_done (void *cls)
+{
+  struct GNUNET_BLOCK_PluginFunctions *api = cls;
+  struct BlockContext *ctx = api->cls;
+
+  if (NULL != ctx->bc)
+    GNUNET_BLOCK_context_destroy (ctx->bc);
+  GNUNET_free (ctx);
+  GNUNET_free (api);
+  return NULL;
+}
+
+
+/* end of plugin_block_consensus.c */