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3 Copyright (C) 2010-2013 GNUnet e.V.
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7 by the Free Software Foundation, either version 3 of the License,
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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.
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16 along with this program. If not, see <http://www.gnu.org/licenses/>.
20 * @file gns/plugin_block_gns.c
21 * @brief blocks used for GNS records
22 * @author Martin Schanzenbach
23 * @author Christian Grothoff
27 #include "gnunet_block_group_lib.h"
28 #include "gnunet_block_plugin.h"
29 #include "gnunet_namestore_service.h"
30 #include "gnunet_signatures.h"
33 * Number of bits we set per entry in the bloomfilter.
34 * Do not change! -from fs
36 #define BLOOMFILTER_K 16
39 * How big is the BF we use for GNS blocks?
45 * Create a new block group.
47 * @param ctx block context in which the block group is created
48 * @param type type of the block for which we are creating the group
49 * @param nonce random value used to seed the group creation
50 * @param raw_data optional serialized prior state of the group, NULL if unavailable/fresh
51 * @param raw_data_size number of bytes in @a raw_data, 0 if unavailable/fresh
52 * @param va variable arguments specific to @a type
53 * @return block group handle, NULL if block groups are not supported
54 * by this @a type of block (this is not an error)
56 static struct GNUNET_BLOCK_Group *
57 block_plugin_gns_create_group (void *cls,
58 enum GNUNET_BLOCK_Type type,
67 guard = va_arg (va, const char *);
68 if (0 == strcmp (guard,
70 bf_size = GNUNET_BLOCK_GROUP_compute_bloomfilter_size (va_arg (va, unsigned int),
72 else if (0 == strcmp (guard,
74 bf_size = va_arg (va, unsigned int);
78 bf_size = GNS_BF_SIZE;
80 GNUNET_break (NULL == va_arg (va, const char *));
81 return GNUNET_BLOCK_GROUP_bf_create (cls,
92 * Function called to validate a reply or a request. For
93 * request evaluation, simply pass "NULL" for the reply_block.
94 * Note that it is assumed that the reply has already been
95 * matched to the key (and signatures checked) as it would
96 * be done with the "get_key" function.
99 * @param ctx block context
100 * @param type block type
101 * @param bg block group to use for evaluation
102 * @param eo control flags
103 * @param query original query (hash)
104 * @param xquery extrended query data (can be NULL, depending on @a type)
105 * @param xquery_size number of bytes in @a xquery
106 * @param reply_block response to validate
107 * @param reply_block_size number of bytes in @a reply_block
108 * @return characterization of result
110 static enum GNUNET_BLOCK_EvaluationResult
111 block_plugin_gns_evaluate (void *cls,
112 struct GNUNET_BLOCK_Context *ctx,
113 enum GNUNET_BLOCK_Type type,
114 struct GNUNET_BLOCK_Group *bg,
115 enum GNUNET_BLOCK_EvaluationOptions eo,
116 const struct GNUNET_HashCode *query,
119 const void *reply_block,
120 size_t reply_block_size)
122 const struct GNUNET_GNSRECORD_Block *block;
123 struct GNUNET_HashCode h;
124 struct GNUNET_HashCode chash;
126 if (type != GNUNET_BLOCK_TYPE_GNS_NAMERECORD)
127 return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
128 if (NULL == reply_block)
130 if (0 != xquery_size)
133 return GNUNET_BLOCK_EVALUATION_REQUEST_INVALID;
135 return GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
138 /* this is a reply */
139 if (reply_block_size < sizeof (struct GNUNET_GNSRECORD_Block))
142 return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
145 if (ntohl (block->purpose.size) + sizeof (struct GNUNET_CRYPTO_EcdsaSignature) + sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey) !=
149 return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
151 GNUNET_CRYPTO_hash (&block->derived_key,
152 sizeof (block->derived_key),
154 if (0 != memcmp (&h, query, sizeof (struct GNUNET_HashCode)))
157 return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
160 GNUNET_GNSRECORD_block_verify (block))
163 return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
165 GNUNET_CRYPTO_hash (reply_block,
169 GNUNET_BLOCK_GROUP_bf_test_and_set (bg,
171 return GNUNET_BLOCK_EVALUATION_OK_DUPLICATE;
172 return GNUNET_BLOCK_EVALUATION_OK_MORE;
177 * Function called to obtain the key for a block.
180 * @param type block type
181 * @param reply_block block to get the key for
182 * @param reply_block_size number of bytes in @a reply_block
183 * @param key set to the key (query) for the given block
184 * @return #GNUNET_OK on success, #GNUNET_SYSERR if type not supported
185 * (or if extracting a key from a block of this type does not work)
188 block_plugin_gns_get_key (void *cls,
189 enum GNUNET_BLOCK_Type type,
190 const void *reply_block,
191 size_t reply_block_size,
192 struct GNUNET_HashCode *key)
194 const struct GNUNET_GNSRECORD_Block *block;
196 if (type != GNUNET_BLOCK_TYPE_GNS_NAMERECORD)
197 return GNUNET_SYSERR;
198 if (reply_block_size < sizeof (struct GNUNET_GNSRECORD_Block))
201 return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
204 GNUNET_CRYPTO_hash (&block->derived_key,
205 sizeof (block->derived_key),
212 * Entry point for the plugin.
215 libgnunet_plugin_block_gns_init (void *cls)
217 static enum GNUNET_BLOCK_Type types[] =
219 GNUNET_BLOCK_TYPE_GNS_NAMERECORD,
220 GNUNET_BLOCK_TYPE_ANY /* end of list */
222 struct GNUNET_BLOCK_PluginFunctions *api;
224 api = GNUNET_new (struct GNUNET_BLOCK_PluginFunctions);
225 api->evaluate = &block_plugin_gns_evaluate;
226 api->get_key = &block_plugin_gns_get_key;
227 api->create_group = &block_plugin_gns_create_group;
234 * Exit point from the plugin.
237 libgnunet_plugin_block_gns_done (void *cls)
239 struct GNUNET_BLOCK_PluginFunctions *api = cls;
245 /* end of plugin_block_gns.c */