2 This file is part of GNUnet.
3 Copyright (C) 2010, 2017 GNUnet e.V.
5 GNUnet is free software: you can redistribute it and/or modify it
6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
8 or (at your option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Affero General Public License for more details.
15 You should have received a copy of the GNU Affero General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
18 SPDX-License-Identifier: AGPL3.0-or-later
23 * @brief library for data block manipulation
24 * @author Christian Grothoff
27 #include "gnunet_util_lib.h"
28 #include "gnunet_constants.h"
29 #include "gnunet_signatures.h"
30 #include "gnunet_block_lib.h"
31 #include "gnunet_block_plugin.h"
35 * Handle for a plugin.
40 * Name of the shared library.
47 struct GNUNET_BLOCK_PluginFunctions *api;
52 * Handle to an initialized block library.
54 struct GNUNET_BLOCK_Context
57 * Array of our plugins.
59 struct Plugin **plugins;
62 * Size of the 'plugins' array.
64 unsigned int num_plugins;
69 const struct GNUNET_CONFIGURATION_Handle *cfg;
74 * Mingle hash with the mingle_number to produce different bits.
76 * @param in original hash code
77 * @param mingle_number number for hash permutation
78 * @param hc where to store the result.
81 GNUNET_BLOCK_mingle_hash (const struct GNUNET_HashCode *in,
82 uint32_t mingle_number,
83 struct GNUNET_HashCode *hc)
85 struct GNUNET_HashCode m;
87 GNUNET_CRYPTO_hash (&mingle_number,
90 GNUNET_CRYPTO_hash_xor (&m,
97 * Add a plugin to the list managed by the block library.
99 * @param cls the block context
100 * @param library_name name of the plugin
101 * @param lib_ret the plugin API
104 add_plugin (void *cls,
105 const char *library_name,
108 struct GNUNET_BLOCK_Context *ctx = cls;
109 struct GNUNET_BLOCK_PluginFunctions *api = lib_ret;
110 struct Plugin *plugin;
112 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
113 "Loading block plugin `%s'\n",
115 plugin = GNUNET_new (struct Plugin);
117 plugin->library_name = GNUNET_strdup (library_name);
118 GNUNET_array_append (ctx->plugins,
126 * Create a block context. Loads the block plugins.
128 * @param cfg configuration to use
129 * @return NULL on error
131 struct GNUNET_BLOCK_Context *
132 GNUNET_BLOCK_context_create (const struct GNUNET_CONFIGURATION_Handle *cfg)
134 struct GNUNET_BLOCK_Context *ctx;
136 ctx = GNUNET_new (struct GNUNET_BLOCK_Context);
138 GNUNET_PLUGIN_load_all ("libgnunet_plugin_block_",
147 * Destroy the block context.
149 * @param ctx context to destroy
152 GNUNET_BLOCK_context_destroy (struct GNUNET_BLOCK_Context *ctx)
154 struct Plugin *plugin;
156 for (unsigned int i = 0; i < ctx->num_plugins; i++)
158 plugin = ctx->plugins[i];
159 GNUNET_break (NULL ==
160 GNUNET_PLUGIN_unload (plugin->library_name,
162 GNUNET_free (plugin->library_name);
163 GNUNET_free (plugin);
165 GNUNET_free (ctx->plugins);
171 * Serialize state of a block group.
173 * @param bg group to serialize
174 * @param[out] nonce set to the nonce of the @a bg
175 * @param[out] raw_data set to the serialized state
176 * @param[out] raw_data_size set to the number of bytes in @a raw_data
177 * @return #GNUNET_OK on success, #GNUNET_NO if serialization is not
178 * supported, #GNUNET_SYSERR on error
181 GNUNET_BLOCK_group_serialize (struct GNUNET_BLOCK_Group *bg,
184 size_t *raw_data_size)
191 if (NULL == bg->serialize_cb)
193 return bg->serialize_cb (bg,
201 * Destroy resources used by a block group.
203 * @param bg group to destroy, NULL is allowed
206 GNUNET_BLOCK_group_destroy (struct GNUNET_BLOCK_Group *bg)
215 * Try merging two block groups. Afterwards, @a bg1 should remain
216 * valid and contain the rules from both @a bg1 and @bg2, and
217 * @a bg2 should be destroyed (as part of this call). The latter
218 * should happen even if merging is not supported.
220 * @param[in,out] bg1 first group to merge, is updated
221 * @param bg2 second group to merge, is destroyed
222 * @return #GNUNET_OK on success,
223 * #GNUNET_NO if merge failed due to different nonce
224 * #GNUNET_SYSERR if merging is not supported
227 GNUNET_BLOCK_group_merge (struct GNUNET_BLOCK_Group *bg1,
228 struct GNUNET_BLOCK_Group *bg2)
236 bg2->destroy_cb (bg2);
239 if (NULL == bg1->merge_cb)
240 return GNUNET_SYSERR;
241 GNUNET_assert (bg1->merge_cb == bg1->merge_cb);
242 ret = bg1->merge_cb (bg1,
244 bg2->destroy_cb (bg2);
250 * Find a plugin for the given type.
252 * @param ctx context to search
253 * @param type type to look for
254 * @return NULL if no matching plugin exists
256 static struct GNUNET_BLOCK_PluginFunctions *
257 find_plugin (struct GNUNET_BLOCK_Context *ctx,
258 enum GNUNET_BLOCK_Type type)
260 struct Plugin *plugin;
263 for (unsigned i = 0; i < ctx->num_plugins; i++)
265 plugin = ctx->plugins[i];
267 while (0 != (plugin->api->types[j]))
269 if (type == plugin->api->types[j])
279 * Create a new block group.
281 * @param ctx block context in which the block group is created
282 * @param type type of the block for which we are creating the group
283 * @param nonce random value used to seed the group creation
284 * @param raw_data optional serialized prior state of the group, NULL if unavailable/fresh
285 * @param raw_data_size number of bytes in @a raw_data, 0 if unavailable/fresh
286 * @return block group handle, NULL if block groups are not supported
287 * by this @a type of block (this is not an error)
289 struct GNUNET_BLOCK_Group *
290 GNUNET_BLOCK_group_create (struct GNUNET_BLOCK_Context *ctx,
291 enum GNUNET_BLOCK_Type type,
293 const void *raw_data,
294 size_t raw_data_size,
297 struct GNUNET_BLOCK_PluginFunctions *plugin;
298 struct GNUNET_BLOCK_Group *bg;
301 plugin = find_plugin (ctx,
305 if (NULL == plugin->create_group)
309 bg = plugin->create_group (plugin->cls,
321 * Function called to validate a reply or a request. For
322 * request evaluation, simply pass "NULL" for the reply_block.
323 * Note that it is assumed that the reply has already been
324 * matched to the key (and signatures checked) as it would
325 * be done with the "get_key" function.
327 * @param ctx block contxt
328 * @param type block type
329 * @param block block group to use
330 * @param eo control flags
331 * @param query original query (hash)
332 * @param xquery extended query data (can be NULL, depending on type)
333 * @param xquery_size number of bytes in @a xquery
334 * @param reply_block response to validate
335 * @param reply_block_size number of bytes in @a reply_block
336 * @return characterization of result
338 enum GNUNET_BLOCK_EvaluationResult
339 GNUNET_BLOCK_evaluate (struct GNUNET_BLOCK_Context *ctx,
340 enum GNUNET_BLOCK_Type type,
341 struct GNUNET_BLOCK_Group *group,
342 enum GNUNET_BLOCK_EvaluationOptions eo,
343 const struct GNUNET_HashCode *query,
346 const void *reply_block,
347 size_t reply_block_size)
349 struct GNUNET_BLOCK_PluginFunctions *plugin = find_plugin (ctx,
353 return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
354 return plugin->evaluate (plugin->cls,
368 * Function called to obtain the key for a block.
370 * @param ctx block context
371 * @param type block type
372 * @param block block to get the key for
373 * @param block_size number of bytes in @a block
374 * @param key set to the key (query) for the given block
375 * @return #GNUNET_OK on success, #GNUNET_SYSERR if type not supported
376 * (or if extracting a key from a block of this type does not work)
379 GNUNET_BLOCK_get_key (struct GNUNET_BLOCK_Context *ctx,
380 enum GNUNET_BLOCK_Type type,
383 struct GNUNET_HashCode *key)
385 struct GNUNET_BLOCK_PluginFunctions *plugin = find_plugin (ctx,
389 return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
390 return plugin->get_key (plugin->cls,
399 * Update block group to filter out the given results. Note that the
400 * use of a hash for seen results implies that the caller magically
401 * knows how the specific block engine hashes for filtering
402 * duplicates, so this API may not always apply.
404 * @param bf_mutator mutation value to use
405 * @param seen_results results already seen
406 * @param seen_results_count number of entries in @a seen_results
407 * @return #GNUNET_SYSERR if not supported, #GNUNET_OK on success
410 GNUNET_BLOCK_group_set_seen (struct GNUNET_BLOCK_Group *bg,
411 const struct GNUNET_HashCode *seen_results,
412 unsigned int seen_results_count)
416 if (NULL == bg->mark_seen_cb)
417 return GNUNET_SYSERR;
418 bg->mark_seen_cb (bg,