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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.
17 * @file dht/plugin_block_dht.c
18 * @brief block plugin for DHT internals (right now, find-peer requests only);
19 * other plugins should be used to store "useful" data in the
20 * DHT (see fs block plugin)
21 * @author Christian Grothoff
24 #include "gnunet_constants.h"
25 #include "gnunet_hello_lib.h"
26 #include "gnunet_block_plugin.h"
27 #include "gnunet_block_group_lib.h"
29 #define DEBUG_DHT GNUNET_EXTRA_LOGGING
32 * Number of bits we set per entry in the bloomfilter.
35 #define BLOOMFILTER_K 16
39 * Create a new block group.
41 * @param ctx block context in which the block group is created
42 * @param type type of the block for which we are creating the group
43 * @param nonce random value used to seed the group creation
44 * @param raw_data optional serialized prior state of the group, NULL if unavailable/fresh
45 * @param raw_data_size number of bytes in @a raw_data, 0 if unavailable/fresh
46 * @param va variable arguments specific to @a type
47 * @return block group handle, NULL if block groups are not supported
48 * by this @a type of block (this is not an error)
50 static struct GNUNET_BLOCK_Group *
51 block_plugin_dht_create_group (void *cls,
52 enum GNUNET_BLOCK_Type type,
61 guard = va_arg (va, const char *);
62 if (0 == strcmp (guard,
64 bf_size = GNUNET_BLOCK_GROUP_compute_bloomfilter_size (va_arg (va,
67 else if (0 == strcmp (guard,
69 bf_size = va_arg (va, unsigned int);
75 GNUNET_break (NULL == va_arg (va, const char *));
76 return GNUNET_BLOCK_GROUP_bf_create (cls,
87 * Function called to validate a reply or a request. For
88 * request evaluation, simply pass "NULL" for the @a reply_block.
92 * @param type block type
93 * @param group block group to check against
94 * @param eo control flags
95 * @param query original query (hash)
96 * @param xquery extended query data (can be NULL, depending on type)
97 * @param xquery_size number of bytes in @a xquery
98 * @param reply_block response to validate
99 * @param reply_block_size number of bytes in @a reply_block
100 * @return characterization of result
102 static enum GNUNET_BLOCK_EvaluationResult
103 block_plugin_dht_evaluate (void *cls,
104 struct GNUNET_BLOCK_Context *ctx,
105 enum GNUNET_BLOCK_Type type,
106 struct GNUNET_BLOCK_Group *group,
107 enum GNUNET_BLOCK_EvaluationOptions eo,
108 const struct GNUNET_HashCode *query,
111 const void *reply_block,
112 size_t reply_block_size)
114 const struct GNUNET_HELLO_Message *hello;
115 struct GNUNET_PeerIdentity pid;
116 const struct GNUNET_MessageHeader *msg;
117 struct GNUNET_HashCode phash;
119 if (type != GNUNET_BLOCK_TYPE_DHT_HELLO)
120 return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
121 if (0 != xquery_size)
124 return GNUNET_BLOCK_EVALUATION_REQUEST_INVALID;
126 if (NULL == reply_block)
127 return GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
128 if (reply_block_size < sizeof (struct GNUNET_MessageHeader))
131 return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
134 if (reply_block_size != ntohs (msg->size))
137 return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
140 if (GNUNET_OK != GNUNET_HELLO_get_id (hello, &pid))
143 return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
145 GNUNET_CRYPTO_hash (&pid,
149 GNUNET_BLOCK_GROUP_bf_test_and_set (group,
151 return GNUNET_BLOCK_EVALUATION_OK_DUPLICATE;
152 return GNUNET_BLOCK_EVALUATION_OK_MORE;
157 * Function called to obtain the key for a block.
160 * @param type block type
161 * @param block block to get the key for
162 * @param block_size number of bytes @a block
163 * @param[out] key set to the key (query) for the given block
164 * @return #GNUNET_OK on success, #GNUNET_SYSERR if type not supported
165 * (or if extracting a key from a block of this type does not work)
168 block_plugin_dht_get_key (void *cls,
169 enum GNUNET_BLOCK_Type type,
172 struct GNUNET_HashCode *key)
174 const struct GNUNET_MessageHeader *msg;
175 const struct GNUNET_HELLO_Message *hello;
176 struct GNUNET_PeerIdentity *pid;
178 if (type != GNUNET_BLOCK_TYPE_DHT_HELLO)
179 return GNUNET_SYSERR;
180 if (block_size < sizeof (struct GNUNET_MessageHeader))
182 GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
184 _("Block not of type %u\n"),
185 GNUNET_BLOCK_TYPE_DHT_HELLO);
189 if (block_size != ntohs (msg->size))
191 GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
193 _("Size mismatch for block\n"),
194 GNUNET_BLOCK_TYPE_DHT_HELLO);
198 memset (key, 0, sizeof (*key));
199 pid = (struct GNUNET_PeerIdentity *) key;
200 if (GNUNET_OK != GNUNET_HELLO_get_id (hello, pid))
202 GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
204 _("Block of type %u is malformed\n"),
205 GNUNET_BLOCK_TYPE_DHT_HELLO);
213 * Entry point for the plugin.
216 libgnunet_plugin_block_dht_init (void *cls)
218 static enum GNUNET_BLOCK_Type types[] =
220 GNUNET_BLOCK_TYPE_DHT_HELLO,
221 GNUNET_BLOCK_TYPE_ANY /* end of list */
223 struct GNUNET_BLOCK_PluginFunctions *api;
225 api = GNUNET_new (struct GNUNET_BLOCK_PluginFunctions);
226 api->evaluate = &block_plugin_dht_evaluate;
227 api->get_key = &block_plugin_dht_get_key;
228 api->create_group = &block_plugin_dht_create_group;
235 * Exit point from the plugin.
238 libgnunet_plugin_block_dht_done (void *cls)
240 struct GNUNET_BLOCK_PluginFunctions *api = cls;
246 /* end of plugin_block_dht.c */