+/*
+ 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 block/plugin_block_fs.c
+ * @brief blocks used for file-sharing
+ * @author Christian Grothoff
+ */
+
+#include "platform.h"
+#include "plugin_block.h"
+#include "gnunet_signatures.h"
+
+#define DEBUG_FS_BLOCK GNUNET_NO
+
+/**
+ * Number of bits we set per entry in the bloomfilter.
+ * Do not change!
+ */
+#define BLOOMFILTER_K 16
+
+/**
+ * Mingle hash with the mingle_number to produce different bits.
+ */
+static void
+mingle_hash (const GNUNET_HashCode * in,
+ int32_t mingle_number,
+ GNUNET_HashCode * hc)
+{
+ GNUNET_HashCode m;
+
+ GNUNET_CRYPTO_hash (&mingle_number,
+ sizeof (int32_t),
+ &m);
+ GNUNET_CRYPTO_hash_xor (&m, in, hc);
+}
+
+
+/**
+ * Function called to validate a reply or a request. For
+ * request evaluation, simply pass "NULL" for the reply_block.
+ * 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 "get_key" function.
+ *
+ * @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 extrended 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_fs_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)
+{
+ const struct SBlock *sb;
+ GNUNET_HashCode chash;
+ GNUNET_HashCode mhash;
+ const GNUNET_HashCode *nsid;
+ GNUNET_HashCode sh;
+
+ switch (type)
+ {
+ case GNUNET_BLOCK_TYPE_DBLOCK:
+ case GNUNET_BLOCK_TYPE_IBLOCK:
+ if (xquery_size != 0)
+ {
+ GNUNET_break_op (0);
+ return GNUNET_BLOCK_EVALUATION_REQUEST_INVALID;
+ }
+ return GNUNET_BLOCK_EVALUATION_OK_LAST;
+ case GNUNET_BLOCK_TYPE_KBLOCK:
+ case GNUNET_BLOCK_TYPE_NBLOCK:
+ if (xquery_size != 0)
+ {
+ GNUNET_break_op (0);
+ return GNUNET_BLOCK_EVALUATION_REQUEST_INVALID;
+ }
+ if (reply_block == NULL)
+ return GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
+ GNUNET_CRYPTO_hash (reply_block,
+ reply_block_size,
+ &chash);
+ mingle_hash (&chash, 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,
+ BLOOMFILTER_K);
+ }
+ GNUNET_CONTAINER_bloomfilter_add (*bf, &mhash);
+ return GNUNET_BLOCK_EVALUATION_OK_MORE;
+ case GNUNET_BLOCK_TYPE_SBLOCK:
+ if (xquery_size != sizeof (GNUNET_HashCode))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_BLOCK_EVALUATION_REQUEST_INVALID;
+ }
+ if (reply_block == NULL)
+ return GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
+ nsid = xquery;
+ if (reply_block_size < sizeof (struct NBlock))
+ return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
+ sb = reply_block;
+ GNUNET_CRYPTO_hash (&sb->subspace,
+ sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
+ &sh);
+ if (0 != memcmp (nsid,
+ &sh,
+ sizeof (GNUNET_HashCode)))
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+ _("Reply mismatched in terms of namespace. Discarded.\n"));
+ return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
+ }
+ GNUNET_CRYPTO_hash (reply_block,
+ reply_block_size,
+ &chash);
+ mingle_hash (&chash, 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,
+ BLOOMFILTER_K);
+ }
+ GNUNET_CONTAINER_bloomfilter_add (*bf, &mhash);
+ return GNUNET_BLOCK_EVALUATION_OK_MORE;
+ default:
+ return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
+ }
+}
+
+
+/**
+ * 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_fs_get_key (void *cls,
+ enum GNUNET_BLOCK_Type type,
+ const void *block,
+ size_t block_size,
+ GNUNET_HashCode *key)
+{
+ const struct KBlock *kb;
+ const struct SBlock *sb;
+ const struct NBlock *nb;
+
+ switch (type)
+ {
+ case GNUNET_BLOCK_TYPE_DBLOCK:
+ case GNUNET_BLOCK_TYPE_IBLOCK:
+ GNUNET_CRYPTO_hash (block, block_size, key);
+ return GNUNET_OK;
+ case GNUNET_BLOCK_TYPE_KBLOCK:
+ if (block_size < sizeof (struct KBlock))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ kb = block;
+ if (block_size - sizeof (struct KBlock) !=
+ ntohl (kb->purpose.size)
+ - sizeof (struct GNUNET_CRYPTO_RsaSignaturePurpose)
+ - sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded) )
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ if (GNUNET_OK !=
+ GNUNET_CRYPTO_rsa_verify (GNUNET_SIGNATURE_PURPOSE_FS_KBLOCK,
+ &kb->purpose,
+ &kb->signature,
+ &kb->keyspace))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ if (key != NULL)
+ GNUNET_CRYPTO_hash (&kb->keyspace,
+ sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
+ key);
+ return GNUNET_OK;
+ case GNUNET_BLOCK_TYPE_SBLOCK:
+ if (block_size < sizeof (struct SBlock))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ sb = block;
+ if (block_size !=
+ ntohl (sb->purpose.size) + sizeof (struct GNUNET_CRYPTO_RsaSignature))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ if (GNUNET_OK !=
+ GNUNET_CRYPTO_rsa_verify (GNUNET_SIGNATURE_PURPOSE_FS_SBLOCK,
+ &sb->purpose,
+ &sb->signature,
+ &sb->subspace))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ if (key != NULL)
+ *key = sb->identifier;
+ return GNUNET_OK;
+ case GNUNET_BLOCK_TYPE_NBLOCK:
+ if (block_size < sizeof (struct NBlock))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ nb = block;
+ if (block_size - sizeof (struct NBlock) !=
+ ntohl (nb->ns_purpose.size)
+ - sizeof (struct GNUNET_CRYPTO_RsaSignaturePurpose)
+ - sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded) )
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ if (block_size !=
+ ntohl (nb->ksk_purpose.size) + sizeof (struct GNUNET_CRYPTO_RsaSignature))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ if (GNUNET_OK !=
+ GNUNET_CRYPTO_rsa_verify (GNUNET_SIGNATURE_PURPOSE_FS_NBLOCK_KSIG,
+ &nb->ksk_purpose,
+ &nb->ksk_signature,
+ &nb->keyspace))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ if (GNUNET_OK !=
+ GNUNET_CRYPTO_rsa_verify (GNUNET_SIGNATURE_PURPOSE_FS_NBLOCK,
+ &nb->ns_purpose,
+ &nb->ns_signature,
+ &nb->subspace))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ /* FIXME: we used to xor ID with NSID,
+ why not here? */
+ if (key != NULL)
+ GNUNET_CRYPTO_hash (&nb->keyspace,
+ sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
+ key);
+ return GNUNET_OK;
+ default:
+ return GNUNET_SYSERR;
+ }
+}
+
+
+/**
+ * Entry point for the plugin.
+ */
+void *
+gnunet_plugin_block_fs_init (void *cls)
+{
+ static enum GNUNET_BLOCK_Type types[] =
+ {
+ GNUNET_BLOCK_TYPE_DBLOCK,
+ GNUNET_BLOCK_TYPE_IBLOCK,
+ GNUNET_BLOCK_TYPE_KBLOCK,
+ GNUNET_BLOCK_TYPE_SBLOCK,
+ GNUNET_BLOCK_TYPE_NBLOCK,
+ GNUNET_BLOCK_TYPE_ANY /* end of list */
+ };
+ struct GNUNET_BLOCK_PluginFunctions *api;
+
+ api = GNUNET_malloc (sizeof (struct GNUNET_BLOCK_PluginFunctions));
+ api->evaluate = &block_plugin_fs_evaluate;
+ api->get_key = &block_plugin_fs_get_key;
+ api->types = types;
+ return api;
+}
+
+
+/**
+ * Exit point from the plugin.
+ */
+void *
+gnunet_plugin_block_fs_done (void *cls)
+{
+ struct GNUNET_TRANSPORT_PluginFunctions *api = cls;
+
+ GNUNET_free (api);
+ return NULL;
+}
+
+/* end of plugin_block_fs.c */