GNUnet  0.17.6
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 
55 static struct GNUNET_BLOCK_Group *
58  const void *raw_data,
59  size_t raw_data_size,
60  va_list va)
61 {
62  unsigned int bf_size;
63  const char *guard;
64 
65  guard = va_arg (va, const char *);
66  if (0 == strcmp (guard,
67  "seen-set-size"))
68  bf_size = GNUNET_BLOCK_GROUP_compute_bloomfilter_size (va_arg (va, unsigned
69  int),
71  else if (0 == strcmp (guard,
72  "filter-size"))
73  bf_size = va_arg (va, unsigned int);
74  else
75  {
76  GNUNET_break (0);
77  bf_size = 8;
78  }
79  GNUNET_break (NULL == va_arg (va, const char *));
80  return GNUNET_BLOCK_GROUP_bf_create (cls,
81  bf_size,
83  type,
84  raw_data,
85  raw_data_size);
86 }
87 
88 
100 static enum GNUNET_GenericReturnValue
102  enum GNUNET_BLOCK_Type type,
103  const struct GNUNET_HashCode *query,
104  const void *xquery,
105  size_t xquery_size)
106 {
107  switch (type)
108  {
110  if (0 != xquery_size)
111  {
112  GNUNET_break_op (0);
113  return GNUNET_NO;
114  }
115  return GNUNET_OK;
116  default:
117  GNUNET_break (0);
118  return GNUNET_SYSERR;
119  }
120 }
121 
122 
132 static enum GNUNET_GenericReturnValue
134  enum GNUNET_BLOCK_Type type,
135  const void *block,
136  size_t block_size)
137 {
138  const struct GNUNET_DNS_Advertisement *ad;
139 
140  switch (type)
141  {
143  if (sizeof(struct GNUNET_DNS_Advertisement) != block_size)
144  {
145  GNUNET_break_op (0);
146  return GNUNET_NO;
147  }
148  ad = block;
149 
150  if (ntohl (ad->purpose.size) !=
151  sizeof(struct GNUNET_DNS_Advertisement)
152  - sizeof(struct GNUNET_CRYPTO_EddsaSignature))
153  {
154  GNUNET_break_op (0);
155  return GNUNET_NO;
156  }
159  {
161  "DNS advertisement has expired\n");
162  return GNUNET_NO;
163  }
164  if (GNUNET_OK !=
166  &ad->purpose,
167  &ad->signature,
168  &ad->peer.public_key))
169  {
170  GNUNET_break_op (0);
171  return GNUNET_NO;
172  }
173  return GNUNET_OK;
174  default:
175  GNUNET_break (0);
176  return GNUNET_SYSERR;
177  }
178 }
179 
180 
199  void *cls,
200  enum GNUNET_BLOCK_Type type,
201  struct GNUNET_BLOCK_Group *group,
202  const struct GNUNET_HashCode *query,
203  const void *xquery,
204  size_t xquery_size,
205  const void *reply_block,
206  size_t reply_block_size)
207 {
208  struct GNUNET_HashCode phash;
209 
210  switch (type)
211  {
213  GNUNET_CRYPTO_hash (reply_block,
214  reply_block_size,
215  &phash);
216  if (GNUNET_YES ==
218  &phash))
221  default:
222  GNUNET_break (0);
224  }
225 }
226 
227 
239 static enum GNUNET_GenericReturnValue
240 block_plugin_dns_get_key (void *cls,
241  enum GNUNET_BLOCK_Type type,
242  const void *block,
243  size_t block_size,
244  struct GNUNET_HashCode *key)
245 {
247  {
248  GNUNET_break (0);
249  return GNUNET_SYSERR;
250  }
251  return GNUNET_NO;
252 }
253 
254 
258 void *
260 {
261  static enum GNUNET_BLOCK_Type types[] = {
263  GNUNET_BLOCK_TYPE_ANY /* end of list */
264  };
265  struct GNUNET_BLOCK_PluginFunctions *api;
266 
273  api->types = types;
274  return api;
275 }
276 
277 
281 void *
283 {
284  struct GNUNET_BLOCK_PluginFunctions *api = cls;
285 
286  GNUNET_free (api);
287  return NULL;
288 }
289 
290 
291 /* end of plugin_block_dns.c */
struct GNUNET_HashCode key
The key used in the DHT.
API for block plugins.
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.
enum GNUNET_GenericReturnValue 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:232
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:268
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, 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:173
@ 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:702
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_log(kind,...)
GNUNET_GenericReturnValue
Named constants for return values.
Definition: gnunet_common.h:96
@ GNUNET_OK
Definition: gnunet_common.h:99
@ GNUNET_YES
@ GNUNET_NO
Definition: gnunet_common.h:98
@ GNUNET_SYSERR
Definition: gnunet_common.h:97
#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.
static struct GNUNET_BLOCK_Group * block_plugin_dns_create_group(void *cls, enum GNUNET_BLOCK_Type type, const void *raw_data, size_t raw_data_size, va_list va)
Create a new block group.
void * libgnunet_plugin_block_dns_done(void *cls)
Exit point from the plugin.
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