2 This file is part of GNUnet
3 Copyright (C) 2013, 2017 GNUnet e.V.
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 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 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 Boston, MA 02110-1301, USA.
22 * @file dns/plugin_block_dns.c
23 * @brief block plugin for advertising a DNS exit service
24 * @author Christian Grothoff
26 * Note that this plugin might more belong with EXIT and PT
27 * as those two are using this type of block. Still, this
28 * might be a natural enough place for people to find the code...
31 #include "gnunet_block_plugin.h"
32 #include "block_dns.h"
33 #include "gnunet_signatures.h"
34 #include "gnunet_block_group_lib.h"
38 * Number of bits we set per entry in the bloomfilter.
41 #define BLOOMFILTER_K 16
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_dns_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);
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.
96 * @param ctx block context
97 * @param type block type
98 * @param bg group to evaluate 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_dns_evaluate (void *cls,
109 struct GNUNET_BLOCK_Context *ctx,
110 enum GNUNET_BLOCK_Type type,
111 struct GNUNET_BLOCK_Group *bg,
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_DNS_Advertisement *ad;
120 struct GNUNET_HashCode phash;
124 case GNUNET_BLOCK_TYPE_DNS:
125 if (0 != xquery_size)
126 return GNUNET_BLOCK_EVALUATION_REQUEST_INVALID;
128 if (NULL == reply_block)
129 return GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
131 if (sizeof (struct GNUNET_DNS_Advertisement) != reply_block_size)
134 return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
138 if (ntohl (ad->purpose.size) !=
139 sizeof (struct GNUNET_DNS_Advertisement) -
140 sizeof (struct GNUNET_CRYPTO_EddsaSignature))
143 return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
146 GNUNET_TIME_absolute_get_remaining (GNUNET_TIME_absolute_ntoh
147 (ad->expiration_time)).rel_value_us)
149 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
150 "DNS advertisement has expired\n");
151 return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
154 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_DNS_RECORD,
157 &ad->peer.public_key))
160 return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
162 GNUNET_CRYPTO_hash (reply_block,
166 GNUNET_BLOCK_GROUP_bf_test_and_set (bg,
168 return GNUNET_BLOCK_EVALUATION_OK_DUPLICATE;
169 return GNUNET_BLOCK_EVALUATION_OK_MORE;
171 return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
177 * Function called to obtain the key for a block.
180 * @param type block type
181 * @param block block to get the key for
182 * @param block_size number of bytes in @a 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_dns_get_key (void *cls,
189 enum GNUNET_BLOCK_Type type,
192 struct GNUNET_HashCode *key)
194 /* we cannot extract a key from a block of this type */
195 return GNUNET_SYSERR;
200 * Entry point for the plugin.
203 libgnunet_plugin_block_dns_init (void *cls)
205 static enum GNUNET_BLOCK_Type types[] =
207 GNUNET_BLOCK_TYPE_DNS,
208 GNUNET_BLOCK_TYPE_ANY /* end of list */
210 struct GNUNET_BLOCK_PluginFunctions *api;
212 api = GNUNET_new (struct GNUNET_BLOCK_PluginFunctions);
213 api->evaluate = &block_plugin_dns_evaluate;
214 api->get_key = &block_plugin_dns_get_key;
215 api->create_group = &block_plugin_dns_create_group;
222 * Exit point from the plugin.
225 libgnunet_plugin_block_dns_done (void *cls)
227 struct GNUNET_BLOCK_PluginFunctions *api = cls;
233 /* end of plugin_block_dns.c */