GNUnet  0.10.x
plugin_block_dht.c
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1 /*
2  This file is part of GNUnet
3  Copyright (C) 2010, 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 
28 #include "platform.h"
29 #include "gnunet_constants.h"
30 #include "gnunet_hello_lib.h"
31 #include "gnunet_block_plugin.h"
32 #include "gnunet_block_group_lib.h"
33 
34 #define DEBUG_DHT GNUNET_EXTRA_LOGGING
35 
40 #define BLOOMFILTER_K 16
41 
42 
55 static struct GNUNET_BLOCK_Group *
58  uint32_t nonce,
59  const void *raw_data,
60  size_t raw_data_size,
61  va_list va)
62 {
63  unsigned int bf_size;
64  const char *guard;
65 
66  guard = va_arg(va, const char *);
67  if (0 == strcmp(guard,
68  "seen-set-size"))
70  unsigned int),
72  else if (0 == strcmp(guard,
73  "filter-size"))
74  bf_size = va_arg(va, unsigned int);
75  else
76  {
77  GNUNET_break(0);
78  bf_size = 8;
79  }
80  GNUNET_break(NULL == va_arg(va, const char *));
82  bf_size,
84  type,
85  nonce,
86  raw_data,
87  raw_data_size);
88 }
89 
90 
109  struct GNUNET_BLOCK_Context *ctx,
110  enum GNUNET_BLOCK_Type type,
111  struct GNUNET_BLOCK_Group *group,
113  const struct GNUNET_HashCode *query,
114  const void *xquery,
115  size_t xquery_size,
116  const void *reply_block,
117  size_t reply_block_size)
118 {
119  const struct GNUNET_HELLO_Message *hello;
120  struct GNUNET_PeerIdentity pid;
121  const struct GNUNET_MessageHeader *msg;
122  struct GNUNET_HashCode phash;
123 
124  if (type != GNUNET_BLOCK_TYPE_DHT_HELLO)
126  if (0 != xquery_size)
127  {
128  GNUNET_break_op(0);
130  }
131  if (NULL == reply_block)
133  if (reply_block_size < sizeof(struct GNUNET_MessageHeader))
134  {
135  GNUNET_break_op(0);
137  }
138  msg = reply_block;
139  if (reply_block_size != ntohs(msg->size))
140  {
141  GNUNET_break_op(0);
143  }
144  hello = reply_block;
145  if (GNUNET_OK != GNUNET_HELLO_get_id(hello, &pid))
146  {
147  GNUNET_break_op(0);
149  }
150  GNUNET_CRYPTO_hash(&pid,
151  sizeof(pid),
152  &phash);
153  if (GNUNET_YES ==
155  &phash))
158 }
159 
160 
172 static int
174  enum GNUNET_BLOCK_Type type,
175  const void *block,
176  size_t block_size,
177  struct GNUNET_HashCode *key)
178 {
179  const struct GNUNET_MessageHeader *msg;
180  const struct GNUNET_HELLO_Message *hello;
181  struct GNUNET_PeerIdentity *pid;
182 
183  if (type != GNUNET_BLOCK_TYPE_DHT_HELLO)
184  return GNUNET_SYSERR;
185  if (block_size < sizeof(struct GNUNET_MessageHeader))
186  {
188  "block-dht",
189  _("Block not of type %u\n"),
191  return GNUNET_NO;
192  }
193  msg = block;
194  if (block_size != ntohs(msg->size))
195  {
197  "block-dht",
198  _("Size mismatch for block\n"),
200  return GNUNET_NO;
201  }
202  hello = block;
203  memset(key, 0, sizeof(*key));
204  pid = (struct GNUNET_PeerIdentity *)key;
205  if (GNUNET_OK != GNUNET_HELLO_get_id(hello, pid))
206  {
208  "block-dht",
209  _("Block of type %u is malformed\n"),
211  return GNUNET_NO;
212  }
213  return GNUNET_OK;
214 }
215 
216 
220 void *
222 {
223  static enum GNUNET_BLOCK_Type types[] =
224  {
226  GNUNET_BLOCK_TYPE_ANY /* end of list */
227  };
228  struct GNUNET_BLOCK_PluginFunctions *api;
229 
234  api->types = types;
235  return api;
236 }
237 
238 
242 void *
244 {
245  struct GNUNET_BLOCK_PluginFunctions *api = cls;
246 
247  GNUNET_free(api);
248  return NULL;
249 }
250 
251 /* end of plugin_block_dht.c */
Block does not match query (invalid result)
int GNUNET_HELLO_get_id(const struct GNUNET_HELLO_Message *hello, struct GNUNET_PeerIdentity *peer)
Get the peer identity from a HELLO message.
Definition: hello.c:662
void * libgnunet_plugin_block_dht_init(void *cls)
Entry point for the plugin.
Handle to an initialized block library.
Definition: block.c:53
A HELLO message is used to exchange information about transports with other peers.
struct GNUNET_MessageHeader * msg
Definition: 005.c:2
enum GNUNET_BLOCK_Type * types
0-terminated array of block types supported by this plugin.
Any type of block, used as a wildcard when searching.
GNUNET_BLOCK_EvaluationFunction evaluate
Main function of a block plugin.
GNUNET_BLOCK_Type
Blocks in the datastore and the datacache must have a unique type.
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:173
Each plugin is required to return a pointer to a struct of this type as the return value from its ent...
#define GNUNET_NO
Definition: gnunet_common.h:78
#define GNUNET_OK
Named constants for return values.
Definition: gnunet_common.h:75
#define GNUNET_new(type)
Allocate a struct or union of the given type.
static struct GNUNET_BLOCK_Group * block_plugin_dht_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.
uint16_t size
The length of the struct (in bytes, including the length field itself), in big-endian format...
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? Sized so that do not have to re-size the filter too often (to keep it cheap).
Definition: bg_bf.c:248
#define GNUNET_break(cond)
Use this for internal assertion violations that are not fatal (can be handled) but should not occur...
static struct GNUNET_DNSSTUB_Context * ctx
Context for DNS resolution.
#define _(String)
GNU gettext support macro.
Definition: platform.h:181
Valid result, but suppressed because it is a duplicate.
#define GNUNET_break_op(cond)
Use this for assertion violations caused by other peers (i.e.
void GNUNET_CRYPTO_hash(const void *block, size_t size, struct GNUNET_HashCode *ret)
Compute hash of a given block.
Definition: crypto_hash.c:44
Type of a block that contains a HELLO for a peer (for DHT and CADET find-peer operations).
A 512-bit hashcode.
Valid result, and there may be more.
struct GNUNET_HashCode key
The key used in the DHT.
#define GNUNET_SYSERR
Definition: gnunet_common.h:76
GNUNET_BLOCK_GroupCreateFunction create_group
Create a block group to process a bunch of blocks in a shared context (i.e.
GNUNET_BLOCK_EvaluationResult
Possible ways for how a block may relate to a query.
Specified block type not supported by this plugin.
#define BLOOMFILTER_K
Number of bits we set per entry in the bloomfilter.
GNUNET_BLOCK_GetKeyFunction get_key
Obtain the key for a given block (if possible).
The identity of the host (wraps the signing key of the peer).
static int block_plugin_dht_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.
Query format does not match block type (invalid query).
Block group data.
enum GNUNET_TESTBED_UnderlayLinkModelType type
the type of this model
Header for all communications.
#define GNUNET_YES
Definition: gnunet_common.h:77
void * libgnunet_plugin_block_dht_done(void *cls)
Exit point from the plugin.
#define GNUNET_log_from(kind, comp,...)
static struct GNUNET_PeerIdentity pid
Identity of the peer we transmit to / connect to.
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:212
void * cls
Closure for all of the callbacks.
GNUNET_BLOCK_EvaluationOptions
Flags that can be set to control the evaluation.
Query is valid, no reply given.
#define GNUNET_free(ptr)
Wrapper around free.
static enum GNUNET_BLOCK_EvaluationResult block_plugin_dht_evaluate(void *cls, struct GNUNET_BLOCK_Context *ctx, enum GNUNET_BLOCK_Type type, struct GNUNET_BLOCK_Group *group, enum GNUNET_BLOCK_EvaluationOptions eo, 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 or a request.