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,
125 * Create a block context. Loads the block plugins.
127 * @param cfg configuration to use
128 * @return NULL on error
130 struct GNUNET_BLOCK_Context *
131 GNUNET_BLOCK_context_create (const struct GNUNET_CONFIGURATION_Handle *cfg)
133 struct GNUNET_BLOCK_Context *ctx;
135 ctx = GNUNET_new (struct GNUNET_BLOCK_Context);
137 GNUNET_PLUGIN_load_all ("libgnunet_plugin_block_",
146 * Destroy the block context.
148 * @param ctx context to destroy
151 GNUNET_BLOCK_context_destroy (struct GNUNET_BLOCK_Context *ctx)
153 struct Plugin *plugin;
155 for (unsigned int i = 0; i < ctx->num_plugins; i++)
157 plugin = ctx->plugins[i];
158 GNUNET_break (NULL ==
159 GNUNET_PLUGIN_unload (plugin->library_name,
161 GNUNET_free (plugin->library_name);
162 GNUNET_free (plugin);
164 GNUNET_free (ctx->plugins);
170 * Serialize state of a block group.
172 * @param bg group to serialize
173 * @param[out] nonce set to the nonce of the @a bg
174 * @param[out] raw_data set to the serialized state
175 * @param[out] raw_data_size set to the number of bytes in @a raw_data
176 * @return #GNUNET_OK on success, #GNUNET_NO if serialization is not
177 * supported, #GNUNET_SYSERR on error
180 GNUNET_BLOCK_group_serialize (struct GNUNET_BLOCK_Group *bg,
183 size_t *raw_data_size)
190 if (NULL == bg->serialize_cb)
192 return bg->serialize_cb (bg,
200 * Destroy resources used by a block group.
202 * @param bg group to destroy, NULL is allowed
205 GNUNET_BLOCK_group_destroy (struct GNUNET_BLOCK_Group *bg)
214 * Try merging two block groups. Afterwards, @a bg1 should remain
215 * valid and contain the rules from both @a bg1 and @bg2, and
216 * @a bg2 should be destroyed (as part of this call). The latter
217 * should happen even if merging is not supported.
219 * @param[in,out] bg1 first group to merge, is updated
220 * @param bg2 second group to merge, is destroyed
221 * @return #GNUNET_OK on success,
222 * #GNUNET_NO if merge failed due to different nonce
223 * #GNUNET_SYSERR if merging is not supported
226 GNUNET_BLOCK_group_merge (struct GNUNET_BLOCK_Group *bg1,
227 struct GNUNET_BLOCK_Group *bg2)
235 bg2->destroy_cb (bg2);
238 if (NULL == bg1->merge_cb)
239 return GNUNET_SYSERR;
240 GNUNET_assert (bg1->merge_cb == bg1->merge_cb);
241 ret = bg1->merge_cb (bg1,
243 bg2->destroy_cb (bg2);
249 * Find a plugin for the given type.
251 * @param ctx context to search
252 * @param type type to look for
253 * @return NULL if no matching plugin exists
255 static struct GNUNET_BLOCK_PluginFunctions *
256 find_plugin (struct GNUNET_BLOCK_Context *ctx,
257 enum GNUNET_BLOCK_Type type)
259 struct Plugin *plugin;
262 for (unsigned i = 0; i < ctx->num_plugins; i++)
264 plugin = ctx->plugins[i];
266 while (0 != (plugin->api->types[j]))
268 if (type == plugin->api->types[j])
278 * Create a new block group.
280 * @param ctx block context in which the block group is created
281 * @param type type of the block for which we are creating the group
282 * @param nonce random value used to seed the group creation
283 * @param raw_data optional serialized prior state of the group, NULL if unavailable/fresh
284 * @param raw_data_size number of bytes in @a raw_data, 0 if unavailable/fresh
285 * @return block group handle, NULL if block groups are not supported
286 * by this @a type of block (this is not an error)
288 struct GNUNET_BLOCK_Group *
289 GNUNET_BLOCK_group_create (struct GNUNET_BLOCK_Context *ctx,
290 enum GNUNET_BLOCK_Type type,
292 const void *raw_data,
293 size_t raw_data_size,
296 struct GNUNET_BLOCK_PluginFunctions *plugin;
297 struct GNUNET_BLOCK_Group *bg;
300 plugin = find_plugin (ctx,
304 if (NULL == plugin->create_group)
308 bg = plugin->create_group (plugin->cls,
320 * Function called to validate a reply or a request. For
321 * request evaluation, simply pass "NULL" for the reply_block.
322 * Note that it is assumed that the reply has already been
323 * matched to the key (and signatures checked) as it would
324 * be done with the "get_key" function.
326 * @param ctx block contxt
327 * @param type block type
328 * @param block block group to use
329 * @param eo control flags
330 * @param query original query (hash)
331 * @param xquery extended query data (can be NULL, depending on type)
332 * @param xquery_size number of bytes in @a xquery
333 * @param reply_block response to validate
334 * @param reply_block_size number of bytes in @a reply_block
335 * @return characterization of result
337 enum GNUNET_BLOCK_EvaluationResult
338 GNUNET_BLOCK_evaluate (struct GNUNET_BLOCK_Context *ctx,
339 enum GNUNET_BLOCK_Type type,
340 struct GNUNET_BLOCK_Group *group,
341 enum GNUNET_BLOCK_EvaluationOptions eo,
342 const struct GNUNET_HashCode *query,
345 const void *reply_block,
346 size_t reply_block_size)
348 struct GNUNET_BLOCK_PluginFunctions *plugin = find_plugin (ctx,
352 return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
353 return plugin->evaluate (plugin->cls,
367 * Function called to obtain the key for a block.
369 * @param ctx block context
370 * @param type block type
371 * @param block block to get the key for
372 * @param block_size number of bytes in @a block
373 * @param key set to the key (query) for the given block
374 * @return #GNUNET_OK on success, #GNUNET_SYSERR if type not supported
375 * (or if extracting a key from a block of this type does not work)
378 GNUNET_BLOCK_get_key (struct GNUNET_BLOCK_Context *ctx,
379 enum GNUNET_BLOCK_Type type,
382 struct GNUNET_HashCode *key)
384 struct GNUNET_BLOCK_PluginFunctions *plugin = find_plugin (ctx,
388 return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
389 return plugin->get_key (plugin->cls,
398 * Update block group to filter out the given results. Note that the
399 * use of a hash for seen results implies that the caller magically
400 * knows how the specific block engine hashes for filtering
401 * duplicates, so this API may not always apply.
403 * @param bf_mutator mutation value to use
404 * @param seen_results results already seen
405 * @param seen_results_count number of entries in @a seen_results
406 * @return #GNUNET_SYSERR if not supported, #GNUNET_OK on success
409 GNUNET_BLOCK_group_set_seen (struct GNUNET_BLOCK_Group *bg,
410 const struct GNUNET_HashCode *seen_results,
411 unsigned int seen_results_count)
415 if (NULL == bg->mark_seen_cb)
416 return GNUNET_SYSERR;
417 bg->mark_seen_cb (bg,