aboutsummaryrefslogtreecommitdiff
path: root/src/dht/plugin_block_dht.c
blob: 19467b9c96b207b8c8ce2025ce89adc9b8f26faf (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
/*
     This file is part of GNUnet
     (C) 2010 Christian Grothoff (and other contributing authors)

     GNUnet is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published
     by the Free Software Foundation; either version 3, or (at your
     option) any later version.

     GNUnet is distributed in the hope that it will be useful, but
     WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with GNUnet; see the file COPYING.  If not, write to the
     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
     Boston, MA 02111-1307, USA.
*/

/**
 * @file dht/plugin_block_dht.c
 * @brief block plugin for DHT internals (right now, find-peer requests only);
 *        other plugins should be used to store "useful" data in the
 *        DHT (see fs block plugin)
 * @author Christian Grothoff
 */

#include "platform.h"
#include "gnunet_constants.h"
#include "gnunet_hello_lib.h"
#include "gnunet_block_plugin.h"

#define DEBUG_DHT GNUNET_EXTRA_LOGGING


/**
 * Function called to validate a reply or a request.  For
 * request evaluation, simply pass "NULL" for the reply_block.
 *
 * @param cls closure
 * @param type block type
 * @param query original query (hash)
 * @param bf pointer to bloom filter associated with query; possibly updated (!)
 * @param bf_mutator mutation value for bf
 * @param xquery extended query data (can be NULL, depending on type)
 * @param xquery_size number of bytes in xquery
 * @param reply_block response to validate
 * @param reply_block_size number of bytes in reply block
 * @return characterization of result
 */
static enum GNUNET_BLOCK_EvaluationResult
block_plugin_dht_evaluate (void *cls, enum GNUNET_BLOCK_Type type,
                           const GNUNET_HashCode * query,
                           struct GNUNET_CONTAINER_BloomFilter **bf,
                           int32_t bf_mutator, const void *xquery,
                           size_t xquery_size, const void *reply_block,
                           size_t reply_block_size)
{
  GNUNET_HashCode mhash;
  const struct GNUNET_HELLO_Message *hello;
  struct GNUNET_PeerIdentity pid;
  const struct GNUNET_MessageHeader *msg;

  if (type != GNUNET_BLOCK_TYPE_DHT_HELLO)
    return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
  if (xquery_size != 0)
    return GNUNET_BLOCK_EVALUATION_REQUEST_INVALID;
  if (reply_block_size == 0)
    return GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
  if (reply_block_size < sizeof (struct GNUNET_MessageHeader))
    return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
  msg = reply_block;
  if (reply_block_size != ntohs (msg->size))
    return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
  hello = reply_block;
  if (GNUNET_OK != GNUNET_HELLO_get_id (hello, &pid))
    return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
  if (NULL != bf)
  {
    GNUNET_BLOCK_mingle_hash (&pid.hashPubKey, bf_mutator, &mhash);
    if (NULL != *bf)
    {
      if (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (*bf, &mhash))
        return GNUNET_BLOCK_EVALUATION_OK_DUPLICATE;
    }
    else
    {
      *bf =
          GNUNET_CONTAINER_bloomfilter_init (NULL, 8,
                                             GNUNET_CONSTANTS_BLOOMFILTER_K);
    }
    GNUNET_CONTAINER_bloomfilter_add (*bf, &mhash);
  }
  return GNUNET_BLOCK_EVALUATION_OK_MORE;
}


/**
 * Function called to obtain the key for a block.
 *
 * @param cls closure
 * @param type block type
 * @param block block to get the key for
 * @param block_size number of bytes in block
 * @param key set to the key (query) for the given block
 * @return GNUNET_OK on success, GNUNET_SYSERR if type not supported
 *         (or if extracting a key from a block of this type does not work)
 */
static int
block_plugin_dht_get_key (void *cls, enum GNUNET_BLOCK_Type type,
                          const void *block, size_t block_size,
                          GNUNET_HashCode * key)
{
  const struct GNUNET_MessageHeader *msg;
  const struct GNUNET_HELLO_Message *hello;
  struct GNUNET_PeerIdentity *pid;

  if (type != GNUNET_BLOCK_TYPE_DHT_HELLO)
    return GNUNET_SYSERR;
  if (block_size < sizeof (struct GNUNET_MessageHeader))
  {
    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR, "block-dht",
                     _("Block not of type %u\n"), GNUNET_BLOCK_TYPE_DHT_HELLO);
    return GNUNET_NO;
  }
  msg = block;
  if (block_size != ntohs (msg->size))
  {
    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR, "block-dht",
                     _("Size mismatch for block\n"),
                     GNUNET_BLOCK_TYPE_DHT_HELLO);
    return GNUNET_NO;
  }
  hello = block;
  pid = (struct GNUNET_PeerIdentity *) key;
  if (GNUNET_OK != GNUNET_HELLO_get_id (hello, pid))
  {
    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR, "block-dht",
                     _("Block of type %u is malformed\n"),
                     GNUNET_BLOCK_TYPE_DHT_HELLO);
    return GNUNET_NO;
  }
  return GNUNET_OK;
}


/**
 * Entry point for the plugin.
 */
void *
libgnunet_plugin_block_dht_init (void *cls)
{
  static enum GNUNET_BLOCK_Type types[] =
  {
    GNUNET_BLOCK_TYPE_DHT_HELLO,
    GNUNET_BLOCK_TYPE_ANY       /* end of list */
  };
  struct GNUNET_BLOCK_PluginFunctions *api;

  api = GNUNET_malloc (sizeof (struct GNUNET_BLOCK_PluginFunctions));
  api->evaluate = &block_plugin_dht_evaluate;
  api->get_key = &block_plugin_dht_get_key;
  api->types = types;
  return api;
}


/**
 * Exit point from the plugin.
 */
void *
libgnunet_plugin_block_dht_done (void *cls)
{
  struct GNUNET_TRANSPORT_PluginFunctions *api = cls;

  GNUNET_free (api);
  return NULL;
}

/* end of plugin_block_dht.c */