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 2, or (at your
+ 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
*/
#include "platform.h"
#include "gnunet_util_lib.h"
+#include "gnunet_constants.h"
#include "gnunet_signatures.h"
#include "gnunet_block_lib.h"
+#include "gnunet_block_plugin.h"
+
/**
- * Check if the given KBlock is well-formed.
+ * Handle for a plugin.
+ */
+struct Plugin
+{
+ /**
+ * Name of the shared library.
+ */
+ char *library_name;
+
+ /**
+ * Plugin API.
+ */
+ struct GNUNET_BLOCK_PluginFunctions *api;
+};
+
+
+/**
+ * Handle to an initialized block library.
+ */
+struct GNUNET_BLOCK_Context
+{
+ /**
+ * Array of our plugins.
+ */
+ struct Plugin **plugins;
+
+ /**
+ * Size of the 'plugins' array.
+ */
+ unsigned int num_plugins;
+
+ /**
+ * Our configuration.
+ */
+ const struct GNUNET_CONFIGURATION_Handle *cfg;
+};
+
+
+/**
+ * Mingle hash with the mingle_number to produce different bits.
*
- * @param kb the kblock data (or at least "dsize" bytes claiming to be one)
- * @param dsize size of "kb" in bytes; check for < sizeof(struct KBlock)!
- * @param query where to store the query that this block answers
- * @return GNUNET_OK if this is actually a well-formed KBlock
+ * @param in original hash code
+ * @param mingle_number number for hash permutation
+ * @param hc where to store the result.
*/
-static int
-check_kblock (const struct KBlock *kb,
- size_t dsize,
- GNUNET_HashCode *query)
+void
+GNUNET_BLOCK_mingle_hash (const struct GNUNET_HashCode *in,
+ uint32_t mingle_number,
+ struct GNUNET_HashCode *hc)
{
- if (dsize < sizeof (struct KBlock))
- {
- GNUNET_break_op (0);
- return GNUNET_SYSERR;
- }
- if (dsize - 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 (query != NULL)
- GNUNET_CRYPTO_hash (&kb->keyspace,
- sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
- query);
- return GNUNET_OK;
+ struct GNUNET_HashCode m;
+
+ GNUNET_CRYPTO_hash (&mingle_number, sizeof (uint32_t), &m);
+ GNUNET_CRYPTO_hash_xor (&m, in, hc);
}
/**
- * Check if the given NBlock is well-formed.
+ * Add a plugin to the list managed by the block library.
*
- * @param nb the nblock data (or at least "dsize" bytes claiming to be one)
- * @param dsize size of "nb" in bytes; check for < sizeof(struct NBlock)!
- * @param query where to store the query that this block answers
- * @return GNUNET_OK if this is actually a well-formed NBlock
+ * @param cls the block context
+ * @param library_name name of the plugin
+ * @param lib_ret the plugin API
*/
-static int
-check_nblock (const struct NBlock *nb,
- size_t dsize,
- GNUNET_HashCode *query)
+static void
+add_plugin (void *cls,
+ const char *library_name,
+ void *lib_ret)
{
- if (dsize < sizeof (struct NBlock))
- {
- GNUNET_break_op (0);
- return GNUNET_SYSERR;
- }
- if (dsize - 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 (dsize !=
- 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;
- }
- if (query != NULL)
- GNUNET_CRYPTO_hash (&nb->keyspace,
- sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
- query);
- return GNUNET_OK;
+ struct GNUNET_BLOCK_Context *ctx = cls;
+ struct GNUNET_BLOCK_PluginFunctions *api = lib_ret;
+ struct Plugin *plugin;
+
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Loading block plugin `%s'\n",
+ library_name);
+ plugin = GNUNET_new (struct Plugin);
+ plugin->api = api;
+ plugin->library_name = GNUNET_strdup (library_name);
+ GNUNET_array_append (ctx->plugins, ctx->num_plugins, plugin);
}
+
/**
- * Check if the given SBlock is well-formed.
+ * Create a block context. Loads the block plugins.
*
- * @param sb the sblock data (or at least "dsize" bytes claiming to be one)
- * @param dsize size of "kb" in bytes; check for < sizeof(struct SBlock)!
- * @param query where to store the query that this block answers
- * @return GNUNET_OK if this is actually a well-formed SBlock
+ * @param cfg configuration to use
+ * @return NULL on error
*/
-static int
-check_sblock (const struct SBlock *sb,
- size_t dsize,
- GNUNET_HashCode *query)
+struct GNUNET_BLOCK_Context *
+GNUNET_BLOCK_context_create (const struct GNUNET_CONFIGURATION_Handle *cfg)
{
- if (dsize < sizeof (struct SBlock))
- {
- GNUNET_break_op (0);
- return GNUNET_SYSERR;
- }
- if (dsize !=
- 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))
+ struct GNUNET_BLOCK_Context *ctx;
+
+ ctx = GNUNET_new (struct GNUNET_BLOCK_Context);
+ ctx->cfg = cfg;
+ GNUNET_PLUGIN_load_all ("libgnunet_plugin_block_", NULL, &add_plugin, ctx);
+ return ctx;
+}
+
+
+/**
+ * Destroy the block context.
+ *
+ * @param ctx context to destroy
+ */
+void
+GNUNET_BLOCK_context_destroy (struct GNUNET_BLOCK_Context *ctx)
+{
+ unsigned int i;
+ struct Plugin *plugin;
+
+ for (i = 0; i < ctx->num_plugins; i++)
+ {
+ plugin = ctx->plugins[i];
+ GNUNET_break (NULL ==
+ GNUNET_PLUGIN_unload (plugin->library_name, plugin->api));
+ GNUNET_free (plugin->library_name);
+ GNUNET_free (plugin);
+ }
+ GNUNET_free (ctx->plugins);
+ GNUNET_free (ctx);
+}
+
+
+/**
+ * Find a plugin for the given type.
+ *
+ * @param ctx context to search
+ * @param type type to look for
+ * @return NULL if no matching plugin exists
+ */
+static struct GNUNET_BLOCK_PluginFunctions *
+find_plugin (struct GNUNET_BLOCK_Context *ctx,
+ enum GNUNET_BLOCK_Type type)
+{
+ struct Plugin *plugin;
+ unsigned int i;
+ unsigned int j;
+
+ for (i = 0; i < ctx->num_plugins; i++)
+ {
+ plugin = ctx->plugins[i];
+ j = 0;
+ while (0 != (plugin->api->types[j]))
{
- GNUNET_break_op (0);
- return GNUNET_SYSERR;
+ if (type == plugin->api->types[j])
+ return plugin->api;
+ j++;
}
- if (query != NULL)
- *query = sb->identifier;
- return GNUNET_OK;
+ }
+ return NULL;
+}
+
+
+/**
+ * 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 ctx block contxt
+ * @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 @a bf
+ * @param xquery extended 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
+ */
+enum GNUNET_BLOCK_EvaluationResult
+GNUNET_BLOCK_evaluate (struct GNUNET_BLOCK_Context *ctx,
+ enum GNUNET_BLOCK_Type type,
+ const struct 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)
+{
+ struct GNUNET_BLOCK_PluginFunctions *plugin = find_plugin (ctx, type);
+
+ if (plugin == NULL)
+ return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
+ return plugin->evaluate (plugin->cls, type, query, bf, bf_mutator, xquery,
+ xquery_size, reply_block, reply_block_size);
}
/**
- * Check if the given block is well-formed (and of the given type).
+ * Function called to obtain the key for a block.
*
- * @param type type of the block
- * @param block the block data (or at least "size" bytes claiming to be one)
- * @param size size of "kb" in bytes; check that it is large enough
- * @param query where to store the query that this block answers
- * @return GNUNET_OK if this is actually a well-formed block,
- * GNUNET_NO if we could not determine the query,
- * GNUNET_SYSERR if the block is malformed
+ * @param ctx block context
+ * @param type block type
+ * @param block block to get the key for
+ * @param block_size number of bytes in @a 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)
*/
int
-GNUNET_BLOCK_check_block (enum GNUNET_BLOCK_Type type,
- const void *block,
- size_t size,
- GNUNET_HashCode *query)
+GNUNET_BLOCK_get_key (struct GNUNET_BLOCK_Context *ctx,
+ enum GNUNET_BLOCK_Type type, const void *block,
+ size_t block_size, struct GNUNET_HashCode * key)
{
- /* first, validate! */
- switch (type)
- {
- case GNUNET_BLOCK_TYPE_DBLOCK:
- case GNUNET_BLOCK_TYPE_IBLOCK:
- GNUNET_CRYPTO_hash (block, size, query);
- break;
- case GNUNET_BLOCK_TYPE_KBLOCK:
- if (GNUNET_OK !=
- check_kblock (block,
- size,
- query))
- return GNUNET_SYSERR;
- break;
- case GNUNET_BLOCK_TYPE_SBLOCK:
- if (GNUNET_OK !=
- check_sblock (block,
- size,
- query))
- return GNUNET_SYSERR;
- break;
- case GNUNET_BLOCK_TYPE_NBLOCK:
- if (GNUNET_OK !=
- check_nblock (block,
- size,
- query))
- return GNUNET_SYSERR;
- return GNUNET_OK;
- case GNUNET_BLOCK_TYPE_ONDEMAND:
- if (size != sizeof (struct OnDemandBlock))
- return GNUNET_SYSERR;
- memset (query, 0, sizeof (GNUNET_HashCode));
- return GNUNET_NO;
- default:
- /* unknown block type */
- GNUNET_break_op (0);
- return GNUNET_SYSERR;
- }
- return GNUNET_OK;
+ struct GNUNET_BLOCK_PluginFunctions *plugin = find_plugin (ctx, type);
+
+ if (plugin == NULL)
+ return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
+ return plugin->get_key (plugin->cls, type, block, block_size, key);
+}
+
+
+/**
+ * How many bytes should a bloomfilter be if we have already seen
+ * entry_count responses? Note that GNUNET_CONSTANTS_BLOOMFILTER_K gives us the number
+ * of bits set per entry. Furthermore, we should not re-size the
+ * filter too often (to keep it cheap).
+ *
+ * Since other peers will also add entries but not resize the filter,
+ * we should generally pick a slightly larger size than what the
+ * strict math would suggest.
+ *
+ * @param entry_count expected number of entries in the Bloom filter
+ * @return must be a power of two and smaller or equal to 2^15.
+ */
+static size_t
+compute_bloomfilter_size (unsigned int entry_count)
+{
+ size_t size;
+ unsigned int ideal = (entry_count * GNUNET_CONSTANTS_BLOOMFILTER_K) / 4;
+ uint16_t max = 1 << 15;
+
+ if (entry_count > max)
+ return max;
+ size = 8;
+ while ((size < max) && (size < ideal))
+ size *= 2;
+ if (size > max)
+ return max;
+ return size;
+}
+
+
+/**
+ * Construct a bloom filter that would filter out the given
+ * results.
+ *
+ * @param bf_mutator mutation value to use
+ * @param seen_results results already seen
+ * @param seen_results_count number of entries in @a seen_results
+ * @return NULL if seen_results_count is 0, otherwise a BF
+ * that would match the given results.
+ */
+struct GNUNET_CONTAINER_BloomFilter *
+GNUNET_BLOCK_construct_bloomfilter (int32_t bf_mutator,
+ const struct GNUNET_HashCode * seen_results,
+ unsigned int seen_results_count)
+{
+ struct GNUNET_CONTAINER_BloomFilter *bf;
+ struct GNUNET_HashCode mhash;
+ unsigned int i;
+ size_t nsize;
+
+ nsize = compute_bloomfilter_size (seen_results_count);
+ bf = GNUNET_CONTAINER_bloomfilter_init (NULL, nsize,
+ GNUNET_CONSTANTS_BLOOMFILTER_K);
+ for (i = 0; i < seen_results_count; i++)
+ {
+ GNUNET_BLOCK_mingle_hash (&seen_results[i], bf_mutator, &mhash);
+ GNUNET_CONTAINER_bloomfilter_add (bf, &mhash);
+ }
+ return bf;
}
projects / oweals / gnunet.git / blobdiff