Imported Upstream version 0.9.2upstream/0.9.2

1 files changed, 181 insertions, 0 deletions

diff --git a/src/dht/plugin_block_dht.c b/src/dht/plugin_block_dht.c
new file mode 100644
index 0000000..19467b9
--- /dev/null
+++ b/src/dht/plugin_block_dht.c
@@ -0,0 +1,181 @@
+/*
+     This file is part of GNUnet
+     (C) 2010 Christian Grothoff (and other contributing authors)
+
+     GNUnet 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.
+
+     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
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+
+/**
+ * @file dht/plugin_block_dht.c
+ * @brief block plugin for DHT internals (right now, find-peer requests only);
+ *        other plugins should be used to store "useful" data in the
+ *        DHT (see fs block plugin)
+ * @author Christian Grothoff
+ */
+
+#include "platform.h"
+#include "gnunet_constants.h"
+#include "gnunet_hello_lib.h"
+#include "gnunet_block_plugin.h"
+
+#define DEBUG_DHT GNUNET_EXTRA_LOGGING
+
+
+/**
+ * Function called to validate a reply or a request.  For
+ * request evaluation, simply pass "NULL" for the reply_block.
+ *
+ * @param cls closure
+ * @param type block type
+ * @param query original query (hash)
+ * @param bf pointer to bloom filter associated with query; possibly updated (!)
+ * @param bf_mutator mutation value for bf
+ * @param xquery extended query data (can be NULL, depending on type)
+ * @param xquery_size number of bytes in xquery
+ * @param reply_block response to validate
+ * @param reply_block_size number of bytes in reply block
+ * @return characterization of result
+ */
+static enum GNUNET_BLOCK_EvaluationResult
+block_plugin_dht_evaluate (void *cls, enum GNUNET_BLOCK_Type type,
+                           const GNUNET_HashCode * query,
+                           struct GNUNET_CONTAINER_BloomFilter **bf,
+                           int32_t bf_mutator, const void *xquery,
+                           size_t xquery_size, const void *reply_block,
+                           size_t reply_block_size)
+{
+  GNUNET_HashCode mhash;
+  const struct GNUNET_HELLO_Message *hello;
+  struct GNUNET_PeerIdentity pid;
+  const struct GNUNET_MessageHeader *msg;
+
+  if (type != GNUNET_BLOCK_TYPE_DHT_HELLO)
+    return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
+  if (xquery_size != 0)
+    return GNUNET_BLOCK_EVALUATION_REQUEST_INVALID;
+  if (reply_block_size == 0)
+    return GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
+  if (reply_block_size < sizeof (struct GNUNET_MessageHeader))
+    return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
+  msg = reply_block;
+  if (reply_block_size != ntohs (msg->size))
+    return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
+  hello = reply_block;
+  if (GNUNET_OK != GNUNET_HELLO_get_id (hello, &pid))
+    return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
+  if (NULL != bf)
+  {
+    GNUNET_BLOCK_mingle_hash (&pid.hashPubKey, bf_mutator, &mhash);
+    if (NULL != *bf)
+    {
+      if (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (*bf, &mhash))
+        return GNUNET_BLOCK_EVALUATION_OK_DUPLICATE;
+    }
+    else
+    {
+      *bf =
+          GNUNET_CONTAINER_bloomfilter_init (NULL, 8,
+                                             GNUNET_CONSTANTS_BLOOMFILTER_K);
+    }
+    GNUNET_CONTAINER_bloomfilter_add (*bf, &mhash);
+  }
+  return GNUNET_BLOCK_EVALUATION_OK_MORE;
+}
+
+
+/**
+ * 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 int
+block_plugin_dht_get_key (void *cls, enum GNUNET_BLOCK_Type type,
+                          const void *block, size_t block_size,
+                          GNUNET_HashCode * key)
+{
+  const struct GNUNET_MessageHeader *msg;
+  const struct GNUNET_HELLO_Message *hello;
+  struct GNUNET_PeerIdentity *pid;
+
+  if (type != GNUNET_BLOCK_TYPE_DHT_HELLO)
+    return GNUNET_SYSERR;
+  if (block_size < sizeof (struct GNUNET_MessageHeader))
+  {
+    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR, "block-dht",
+                     _("Block not of type %u\n"), GNUNET_BLOCK_TYPE_DHT_HELLO);
+    return GNUNET_NO;
+  }
+  msg = block;
+  if (block_size != ntohs (msg->size))
+  {
+    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR, "block-dht",
+                     _("Size mismatch for block\n"),
+                     GNUNET_BLOCK_TYPE_DHT_HELLO);
+    return GNUNET_NO;
+  }
+  hello = block;
+  pid = (struct GNUNET_PeerIdentity *) key;
+  if (GNUNET_OK != GNUNET_HELLO_get_id (hello, pid))
+  {
+    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR, "block-dht",
+                     _("Block of type %u is malformed\n"),
+                     GNUNET_BLOCK_TYPE_DHT_HELLO);
+    return GNUNET_NO;
+  }
+  return GNUNET_OK;
+}
+
+
+/**
+ * Entry point for the plugin.
+ */
+void *
+libgnunet_plugin_block_dht_init (void *cls)
+{
+  static enum GNUNET_BLOCK_Type types[] =
+  {
+    GNUNET_BLOCK_TYPE_DHT_HELLO,
+    GNUNET_BLOCK_TYPE_ANY       /* end of list */
+  };
+  struct GNUNET_BLOCK_PluginFunctions *api;
+
+  api = GNUNET_malloc (sizeof (struct GNUNET_BLOCK_PluginFunctions));
+  api->evaluate = &block_plugin_dht_evaluate;
+  api->get_key = &block_plugin_dht_get_key;
+  api->types = types;
+  return api;
+}
+
+
+/**
+ * Exit point from the plugin.
+ */
+void *
+libgnunet_plugin_block_dht_done (void *cls)
+{
+  struct GNUNET_TRANSPORT_PluginFunctions *api = cls;
+
+  GNUNET_free (api);
+  return NULL;
+}
+
+/* end of plugin_block_dht.c */