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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
22 * @file dht/plugin_block_dht.c
23 * @brief block plugin for DHT internals (right now, find-peer requests only);
24 * other plugins should be used to store "useful" data in the
25 * DHT (see fs block plugin)
26 * @author Christian Grothoff
29 #include "gnunet_constants.h"
30 #include "gnunet_hello_lib.h"
31 #include "gnunet_block_plugin.h"
32 #include "gnunet_block_group_lib.h"
34 #define DEBUG_DHT GNUNET_EXTRA_LOGGING
37 * Number of bits we set per entry in the bloomfilter.
40 #define BLOOMFILTER_K 16
44 * Create a new block group.
46 * @param ctx block context in which the block group is created
47 * @param type type of the block for which we are creating the group
48 * @param nonce random value used to seed the group creation
49 * @param raw_data optional serialized prior state of the group, NULL if unavailable/fresh
50 * @param raw_data_size number of bytes in @a raw_data, 0 if unavailable/fresh
51 * @param va variable arguments specific to @a type
52 * @return block group handle, NULL if block groups are not supported
53 * by this @a type of block (this is not an error)
55 static struct GNUNET_BLOCK_Group *
56 block_plugin_dht_create_group (void *cls,
57 enum GNUNET_BLOCK_Type type,
66 guard = va_arg (va, const char *);
67 if (0 == strcmp (guard,
69 bf_size = GNUNET_BLOCK_GROUP_compute_bloomfilter_size (va_arg (va,
72 else if (0 == strcmp (guard,
74 bf_size = va_arg (va, unsigned int);
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 @a reply_block.
97 * @param type block type
98 * @param group block group to check against
99 * @param eo control flags
100 * @param query original query (hash)
101 * @param xquery extended query data (can be NULL, depending on type)
102 * @param xquery_size number of bytes in @a xquery
103 * @param reply_block response to validate
104 * @param reply_block_size number of bytes in @a reply_block
105 * @return characterization of result
107 static enum GNUNET_BLOCK_EvaluationResult
108 block_plugin_dht_evaluate (void *cls,
109 struct GNUNET_BLOCK_Context *ctx,
110 enum GNUNET_BLOCK_Type type,
111 struct GNUNET_BLOCK_Group *group,
112 enum GNUNET_BLOCK_EvaluationOptions eo,
113 const struct GNUNET_HashCode *query,
116 const void *reply_block,
117 size_t reply_block_size)
119 const struct GNUNET_HELLO_Message *hello;
120 struct GNUNET_PeerIdentity pid;
121 const struct GNUNET_MessageHeader *msg;
122 struct GNUNET_HashCode phash;
124 if (type != GNUNET_BLOCK_TYPE_DHT_HELLO)
125 return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
126 if (0 != xquery_size)
129 return GNUNET_BLOCK_EVALUATION_REQUEST_INVALID;
131 if (NULL == reply_block)
132 return GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
133 if (reply_block_size < sizeof(struct GNUNET_MessageHeader))
136 return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
139 if (reply_block_size != ntohs (msg->size))
142 return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
145 if (GNUNET_OK != GNUNET_HELLO_get_id (hello, &pid))
148 return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
150 GNUNET_CRYPTO_hash (&pid,
154 GNUNET_BLOCK_GROUP_bf_test_and_set (group,
156 return GNUNET_BLOCK_EVALUATION_OK_DUPLICATE;
157 return GNUNET_BLOCK_EVALUATION_OK_MORE;
162 * Function called to obtain the key for a block.
165 * @param type block type
166 * @param block block to get the key for
167 * @param block_size number of bytes @a block
168 * @param[out] key set to the key (query) for the given block
169 * @return #GNUNET_OK on success, #GNUNET_SYSERR if type not supported
170 * (or if extracting a key from a block of this type does not work)
173 block_plugin_dht_get_key (void *cls,
174 enum GNUNET_BLOCK_Type type,
177 struct GNUNET_HashCode *key)
179 const struct GNUNET_MessageHeader *msg;
180 const struct GNUNET_HELLO_Message *hello;
181 struct GNUNET_PeerIdentity *pid;
183 if (type != GNUNET_BLOCK_TYPE_DHT_HELLO)
184 return GNUNET_SYSERR;
185 if (block_size < sizeof(struct GNUNET_MessageHeader))
187 GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
189 _ ("Block not of type %u\n"),
190 GNUNET_BLOCK_TYPE_DHT_HELLO);
194 if (block_size != ntohs (msg->size))
196 GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
198 _ ("Size mismatch for block\n"),
199 GNUNET_BLOCK_TYPE_DHT_HELLO);
203 memset (key, 0, sizeof(*key));
204 pid = (struct GNUNET_PeerIdentity *) key;
205 if (GNUNET_OK != GNUNET_HELLO_get_id (hello, pid))
207 GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
209 _ ("Block of type %u is malformed\n"),
210 GNUNET_BLOCK_TYPE_DHT_HELLO);
218 * Entry point for the plugin.
221 libgnunet_plugin_block_dht_init (void *cls)
223 static enum GNUNET_BLOCK_Type types[] = {
224 GNUNET_BLOCK_TYPE_DHT_HELLO,
225 GNUNET_BLOCK_TYPE_ANY /* end of list */
227 struct GNUNET_BLOCK_PluginFunctions *api;
229 api = GNUNET_new (struct GNUNET_BLOCK_PluginFunctions);
230 api->evaluate = &block_plugin_dht_evaluate;
231 api->get_key = &block_plugin_dht_get_key;
232 api->create_group = &block_plugin_dht_create_group;
239 * Exit point from the plugin.
242 libgnunet_plugin_block_dht_done (void *cls)
244 struct GNUNET_BLOCK_PluginFunctions *api = cls;
251 /* end of plugin_block_dht.c */