GNUnet  0.11.x
plugin_block_dns.c
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1 /*
2  This file is part of GNUnet
3  Copyright (C) 2013, 2017 GNUnet e.V.
4 
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.
9 
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.
14 
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/>.
17 
18  SPDX-License-Identifier: AGPL3.0-or-later
19  */
20 
30 #include "platform.h"
31 #include "gnunet_block_plugin.h"
32 #include "block_dns.h"
33 #include "gnunet_signatures.h"
34 #include "gnunet_block_group_lib.h"
35 
36 
41 #define BLOOMFILTER_K 16
42 
43 
56 static struct GNUNET_BLOCK_Group *
59  uint32_t nonce,
60  const void *raw_data,
61  size_t raw_data_size,
62  va_list va)
63 {
64  unsigned int bf_size;
65  const char *guard;
66 
67  guard = va_arg (va, const char *);
68  if (0 == strcmp (guard,
69  "seen-set-size"))
70  bf_size = GNUNET_BLOCK_GROUP_compute_bloomfilter_size (va_arg (va, unsigned
71  int),
73  else if (0 == strcmp (guard,
74  "filter-size"))
75  bf_size = va_arg (va, unsigned int);
76  else
77  {
78  GNUNET_break (0);
79  bf_size = 8;
80  }
81  GNUNET_break (NULL == va_arg (va, const char *));
82  return GNUNET_BLOCK_GROUP_bf_create (cls,
83  bf_size,
85  type,
86  nonce,
87  raw_data,
88  raw_data_size);
89 }
90 
91 
103 static enum GNUNET_GenericReturnValue
105  enum GNUNET_BLOCK_Type type,
106  const struct GNUNET_HashCode *query,
107  const void *xquery,
108  size_t xquery_size)
109 {
110  switch (type)
111  {
113  if (0 != xquery_size)
114  {
115  GNUNET_break_op (0);
116  return GNUNET_NO;
117  }
118  return GNUNET_OK;
119  default:
120  GNUNET_break (0);
121  return GNUNET_SYSERR;
122  }
123 }
124 
125 
135 static enum GNUNET_GenericReturnValue
137  enum GNUNET_BLOCK_Type type,
138  const void *block,
139  size_t block_size)
140 {
141  const struct GNUNET_DNS_Advertisement *ad;
142 
143  switch (type)
144  {
146  if (sizeof(struct GNUNET_DNS_Advertisement) != block_size)
147  {
148  GNUNET_break_op (0);
149  return GNUNET_NO;
150  }
151  ad = block;
152 
153  if (ntohl (ad->purpose.size) !=
154  sizeof(struct GNUNET_DNS_Advertisement)
155  - sizeof(struct GNUNET_CRYPTO_EddsaSignature))
156  {
157  GNUNET_break_op (0);
158  return GNUNET_NO;
159  }
162  {
164  "DNS advertisement has expired\n");
165  return GNUNET_NO;
166  }
167  if (GNUNET_OK !=
169  &ad->purpose,
170  &ad->signature,
171  &ad->peer.public_key))
172  {
173  GNUNET_break_op (0);
174  return GNUNET_NO;
175  }
176  return GNUNET_OK;
177  default:
178  GNUNET_break (0);
179  return GNUNET_SYSERR;
180  }
181 }
182 
183 
202  void *cls,
203  enum GNUNET_BLOCK_Type type,
204  struct GNUNET_BLOCK_Group *group,
205  const struct GNUNET_HashCode *query,
206  const void *xquery,
207  size_t xquery_size,
208  const void *reply_block,
209  size_t reply_block_size)
210 {
211  struct GNUNET_HashCode phash;
212 
213  switch (type)
214  {
216  GNUNET_CRYPTO_hash (reply_block,
217  reply_block_size,
218  &phash);
219  if (GNUNET_YES ==
221  &phash))
224  default:
225  GNUNET_break (0);
227  }
228 }
229 
230 
242 static enum GNUNET_GenericReturnValue
243 block_plugin_dns_get_key (void *cls,
244  enum GNUNET_BLOCK_Type type,
245  const void *block,
246  size_t block_size,
247  struct GNUNET_HashCode *key)
248 {
250  {
251  GNUNET_break (0);
252  return GNUNET_SYSERR;
253  }
254  return GNUNET_NO;
255 }
256 
257 
261 void *
263 {
264  static enum GNUNET_BLOCK_Type types[] = {
266  GNUNET_BLOCK_TYPE_ANY /* end of list */
267  };
268  struct GNUNET_BLOCK_PluginFunctions *api;
269 
276  api->types = types;
277  return api;
278 }
279 
280 
284 void *
286 {
287  struct GNUNET_BLOCK_PluginFunctions *api = cls;
288 
289  GNUNET_free (api);
290  return NULL;
291 }
292 
293 
294 /* end of plugin_block_dns.c */
struct GNUNET_HashCode key
The key used in the DHT.
#define GNUNET_log(kind,...)
GNUNET_GenericReturnValue
Named constants for return values.
Definition: gnunet_common.h:92
@ GNUNET_OK
Definition: gnunet_common.h:95
@ GNUNET_YES
Definition: gnunet_common.h:97
@ GNUNET_NO
Definition: gnunet_common.h:94
@ GNUNET_SYSERR
Definition: gnunet_common.h:93
GNUNET_BLOCK_Type
WARNING: This header is generated! In order to add DHT block types, you must register them in GANA,...
@ GNUNET_BLOCK_TYPE_DNS
Block for storing DNS exit service advertisements.
@ GNUNET_BLOCK_TYPE_ANY
Identifier for any block.
#define GNUNET_SIGNATURE_PURPOSE_DNS_RECORD
Signature on a GNUNET_DNS_Advertisement.
int GNUNET_BLOCK_GROUP_bf_test_and_set(struct GNUNET_BLOCK_Group *bg, const struct GNUNET_HashCode *hc)
Test if hc is contained in the Bloom filter of bg.
Definition: bg_bf.c:214
size_t GNUNET_BLOCK_GROUP_compute_bloomfilter_size(unsigned int entry_count, unsigned int k)
How many bytes should a bloomfilter be if we have already seen entry_count responses?...
Definition: bg_bf.c:250
GNUNET_BLOCK_ReplyEvaluationResult
Possible ways for how a block may relate to a query.
struct GNUNET_BLOCK_Group * GNUNET_BLOCK_GROUP_bf_create(void *cls, size_t bf_size, unsigned int bf_k, enum GNUNET_BLOCK_Type type, uint32_t nonce, const void *raw_data, size_t raw_data_size)
Create a new block group that filters duplicates using a Bloom filter.
Definition: bg_bf.c:174
@ GNUNET_BLOCK_REPLY_OK_MORE
Valid result, and there may be more.
@ GNUNET_BLOCK_REPLY_OK_DUPLICATE
Valid result, but suppressed because it is a duplicate.
@ GNUNET_BLOCK_REPLY_TYPE_NOT_SUPPORTED
Specified block type not supported by any plugin.
enum GNUNET_GenericReturnValue GNUNET_CRYPTO_eddsa_verify_(uint32_t purpose, const struct GNUNET_CRYPTO_EccSignaturePurpose *validate, const struct GNUNET_CRYPTO_EddsaSignature *sig, const struct GNUNET_CRYPTO_EddsaPublicKey *pub)
Verify EdDSA signature.
Definition: crypto_ecc.c:682
void GNUNET_CRYPTO_hash(const void *block, size_t size, struct GNUNET_HashCode *ret)
Compute hash of a given block.
Definition: crypto_hash.c:41
#define GNUNET_break_op(cond)
Use this for assertion violations caused by other peers (i.e.
#define GNUNET_break(cond)
Use this for internal assertion violations that are not fatal (can be handled) but should not occur.
@ GNUNET_ERROR_TYPE_DEBUG
#define GNUNET_new(type)
Allocate a struct or union of the given type.
#define GNUNET_free(ptr)
Wrapper around free.
struct GNUNET_TIME_Absolute GNUNET_TIME_absolute_ntoh(struct GNUNET_TIME_AbsoluteNBO a)
Convert absolute time from network byte order.
Definition: time.c:736
bool GNUNET_TIME_absolute_is_past(struct GNUNET_TIME_Absolute abs)
Test if abs is truly in the past (excluding now).
Definition: time.c:668
void * libgnunet_plugin_block_dns_init(void *cls)
Entry point for the plugin.
static enum GNUNET_BLOCK_ReplyEvaluationResult block_plugin_dns_check_reply(void *cls, enum GNUNET_BLOCK_Type type, struct GNUNET_BLOCK_Group *group, const struct GNUNET_HashCode *query, const void *xquery, size_t xquery_size, const void *reply_block, size_t reply_block_size)
Function called to validate a reply to a request.
static enum GNUNET_GenericReturnValue block_plugin_dns_check_block(void *cls, enum GNUNET_BLOCK_Type type, const void *block, size_t block_size)
Function called to validate a block for storage.
#define BLOOMFILTER_K
Number of bits we set per entry in the bloomfilter.
static enum GNUNET_GenericReturnValue block_plugin_dns_check_query(void *cls, enum GNUNET_BLOCK_Type type, const struct GNUNET_HashCode *query, const void *xquery, size_t xquery_size)
Function called to validate a query.
static enum GNUNET_GenericReturnValue block_plugin_dns_get_key(void *cls, enum GNUNET_BLOCK_Type type, const void *block, size_t block_size, struct GNUNET_HashCode *key)
Function called to obtain the key for a block.
void * libgnunet_plugin_block_dns_done(void *cls)
Exit point from the plugin.
static struct GNUNET_BLOCK_Group * block_plugin_dns_create_group(void *cls, enum GNUNET_BLOCK_Type type, uint32_t nonce, const void *raw_data, size_t raw_data_size, va_list va)
Create a new block group.
Block group data.
Each plugin is required to return a pointer to a struct of this type as the return value from its ent...
enum GNUNET_BLOCK_Type * types
0-terminated array of block types supported by this plugin.
GNUNET_BLOCK_QueryEvaluationFunction check_query
Check that a query is well-formed.
GNUNET_BLOCK_BlockEvaluationFunction check_block
Check that a block is well-formed.
GNUNET_BLOCK_GetKeyFunction get_key
Obtain the key for a given block (if possible).
GNUNET_BLOCK_ReplyEvaluationFunction check_reply
Check that a reply block matches a query.
GNUNET_BLOCK_GroupCreateFunction create_group
Create a block group to process a bunch of blocks in a shared context (i.e.
void * cls
Closure for all of the callbacks.
uint32_t size
How many bytes does this signature sign? (including this purpose header); in network byte order (!...
an ECC signature using EdDSA.
This is the structure describing an DNS exit service.
Definition: block_dns.h:41
struct GNUNET_PeerIdentity peer
The peer providing this service.
Definition: block_dns.h:61
struct GNUNET_TIME_AbsoluteNBO expiration_time
When does this signature expire?
Definition: block_dns.h:56
struct GNUNET_CRYPTO_EddsaSignature signature
Signature of the peer affirming that it is offering the service.
Definition: block_dns.h:45
struct GNUNET_CRYPTO_EccSignaturePurpose purpose
Beginning of signed portion of the record, signs everything until the end of the struct.
Definition: block_dns.h:51
A 512-bit hashcode.
struct GNUNET_CRYPTO_EddsaPublicKey public_key
enum GNUNET_TESTBED_UnderlayLinkModelType type
the type of this model