/*
This file is part of GNUnet.
- (C) 2010 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2010, 2017 GNUnet e.V.
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
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.
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA.
*/
/**
*/
#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"
+
+
+/**
+ * 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;
+};
+
/**
- * Check if the given KBlock is well-formed.
+ * 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))
- {
- GNUNET_break_op (0);
- return GNUNET_SYSERR;
- }
- if (query != NULL)
- *query = sb->identifier;
- return GNUNET_OK;
+ 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);
+}
+
+
+/**
+ * Serialize state of a block group.
+ *
+ * @param bg group to serialize
+ * @param[out] nonce set to the nonce of the @a bg
+ * @param[out] raw_data set to the serialized state
+ * @param[out] raw_data_size set to the number of bytes in @a raw_data
+ * @return #GNUNET_OK on success, #GNUNET_NO if serialization is not
+ * supported, #GNUNET_SYSERR on error
+ */
+int
+GNUNET_BLOCK_group_serialize (struct GNUNET_BLOCK_Group *bg,
+ uint32_t *nonce,
+ void **raw_data,
+ size_t *raw_data_size)
+{
+ *nonce = 0;
+ *raw_data = NULL;
+ *raw_data_size = 0;
+ if (NULL == bg)
+ return GNUNET_NO;
+ if (NULL == bg->serialize_cb)
+ return GNUNET_NO;
+ return bg->serialize_cb (bg,
+ nonce,
+ raw_data,
+ raw_data_size);
+}
+
+
+/**
+ * Destroy resources used by a block group.
+ *
+ * @param bg group to destroy, NULL is allowed
+ */
+void
+GNUNET_BLOCK_group_destroy (struct GNUNET_BLOCK_Group *bg)
+{
+ if (NULL == bg)
+ return;
+ bg->destroy_cb (bg);
}
/**
- * Check if the given block is well-formed (and of the given type).
+ * Try merging two block groups. Afterwards, @a bg1 should remain
+ * valid and contain the rules from both @a bg1 and @bg2, and
+ * @a bg2 should be destroyed (as part of this call). The latter
+ * should happen even if merging is not supported.
*
- * @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[in,out] bg1 first group to merge, is updated
+ * @param bg2 second group to merge, is destroyed
+ * @return #GNUNET_OK on success,
+ * #GNUNET_NO if merge failed due to different nonce
+ * #GNUNET_SYSERR if merging is not supported
*/
int
-GNUNET_BLOCK_check_block (enum GNUNET_BLOCK_Type type,
- const void *block,
- size_t size,
- GNUNET_HashCode *query)
+GNUNET_BLOCK_group_merge (struct GNUNET_BLOCK_Group *bg1,
+ struct GNUNET_BLOCK_Group *bg2)
{
- /* first, validate! */
- switch (type)
+ int ret;
+
+ if (NULL == bg2)
+ return GNUNET_OK;
+ if (NULL == bg1)
+ {
+ bg2->destroy_cb (bg2);
+ return GNUNET_OK;
+ }
+ if (NULL == bg1->merge_cb)
+ return GNUNET_SYSERR;
+ GNUNET_assert (bg1->merge_cb == bg1->merge_cb);
+ ret = bg1->merge_cb (bg1,
+ bg2);
+ bg2->destroy_cb (bg2);
+ return ret;
+}
+
+
+/**
+ * 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 j;
+
+ for (unsigned i = 0; i < ctx->num_plugins; i++)
+ {
+ plugin = ctx->plugins[i];
+ j = 0;
+ while (0 != (plugin->api->types[j]))
{
- 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;
+ if (type == plugin->api->types[j])
+ return plugin->api;
+ j++;
}
+ }
+ return NULL;
+}
+
+
+/**
+ * Create a new block group.
+ *
+ * @param ctx block context in which the block group is created
+ * @param type type of the block for which we are creating the group
+ * @param nonce random value used to seed the group creation
+ * @param raw_data optional serialized prior state of the group, NULL if unavailable/fresh
+ * @param raw_data_size number of bytes in @a raw_data, 0 if unavailable/fresh
+ * @return block group handle, NULL if block groups are not supported
+ * by this @a type of block (this is not an error)
+ */
+struct GNUNET_BLOCK_Group *
+GNUNET_BLOCK_group_create (struct GNUNET_BLOCK_Context *ctx,
+ enum GNUNET_BLOCK_Type type,
+ uint32_t nonce,
+ const void *raw_data,
+ size_t raw_data_size,
+ ...)
+{
+ struct GNUNET_BLOCK_PluginFunctions *plugin;
+ struct GNUNET_BLOCK_Group *bg;
+ va_list ap;
+
+ plugin = find_plugin (ctx,
+ type);
+ if (NULL == plugin->create_group)
+ return NULL;
+ va_start (ap,
+ raw_data_size);
+ bg = plugin->create_group (plugin->cls,
+ type,
+ nonce,
+ raw_data,
+ raw_data_size,
+ ap);
+ va_end (ap);
+ return bg;
+}
+
+
+/**
+ * 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 block block group to use
+ * @param eo control flags
+ * @param query original query (hash)
+ * @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,
+ struct GNUNET_BLOCK_Group *group,
+ enum GNUNET_BLOCK_EvaluationOptions eo,
+ const struct GNUNET_HashCode *query,
+ 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 (NULL == plugin)
+ return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
+ return plugin->evaluate (plugin->cls,
+ type,
+ group,
+ eo,
+ query,
+ xquery,
+ xquery_size,
+ reply_block,
+ reply_block_size);
+}
+
+
+/**
+ * Function called to obtain the key for a block.
+ *
+ * @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_get_key (struct GNUNET_BLOCK_Context *ctx,
+ enum GNUNET_BLOCK_Type type,
+ const void *block,
+ size_t block_size,
+ struct GNUNET_HashCode *key)
+{
+ 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);
+}
+
+
+/**
+ * Update block group to filter out the given results. Note that the
+ * use of a hash for seen results implies that the caller magically
+ * knows how the specific block engine hashes for filtering
+ * duplicates, so this API may not always apply.
+ *
+ * @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 #GNUNET_SYSERR if not supported, #GNUNET_OK on success
+ */
+int
+GNUNET_BLOCK_group_set_seen (struct GNUNET_BLOCK_Group *bg,
+ const struct GNUNET_HashCode *seen_results,
+ unsigned int seen_results_count)
+{
+ if (NULL == bg)
+ return GNUNET_OK;
+ if (NULL == bg->mark_seen_cb)
+ return GNUNET_SYSERR;
+ bg->mark_seen_cb (bg,
+ seen_results,
+ seen_results_count);
return GNUNET_OK;
}