aboutsummaryrefslogtreecommitdiff
path: root/src/namecache/plugin_namecache_postgres.c
blob: e4b360ef28d2f202df29c89395cd2b862bbf1210 (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
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
/*
 * This file is part of GNUnet
 * Copyright (C) 2009-2013, 2016, 2017 GNUnet e.V.
 *
 * GNUnet is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Affero General Public License as published
 * by the Free Software Foundation, either version 3 of the License,
 * 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
 * Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

    SPDX-License-Identifier: AGPL3.0-or-later
 */

/**
 * @file namecache/plugin_namecache_postgres.c
 * @brief postgres-based namecache backend
 * @author Christian Grothoff
 */
#include "platform.h"
#include "gnunet_namecache_plugin.h"
#include "gnunet_namecache_service.h"
#include "gnunet_gnsrecord_lib.h"
#include "gnunet_pq_lib.h"
#include "namecache.h"


#define LOG(kind, ...) GNUNET_log_from (kind, "namecache-postgres", __VA_ARGS__)


/**
 * Context for all functions in this plugin.
 */
struct Plugin
{
  const struct GNUNET_CONFIGURATION_Handle *cfg;

  /**
   * Native Postgres database handle.
   */
  PGconn *dbh;
};


/**
 * Initialize the database connections and associated
 * data structures (create tables and indices
 * as needed as well).
 *
 * @param plugin the plugin context (state for this module)
 * @return #GNUNET_OK on success
 */
static int
database_setup (struct Plugin *plugin)
{
  struct GNUNET_PQ_ExecuteStatement es_temporary =
    GNUNET_PQ_make_execute ("CREATE TEMPORARY TABLE IF NOT EXISTS ns096blocks ("
                            " query BYTEA NOT NULL DEFAULT '',"
                            " block BYTEA NOT NULL DEFAULT '',"
                            " expiration_time BIGINT NOT NULL DEFAULT 0"
                            ")"
                            "WITH OIDS");
  struct GNUNET_PQ_ExecuteStatement es_default =
    GNUNET_PQ_make_execute ("CREATE TABLE IF NOT EXISTS ns096blocks ("
                            " query BYTEA NOT NULL DEFAULT '',"
                            " block BYTEA NOT NULL DEFAULT '',"
                            " expiration_time BIGINT NOT NULL DEFAULT 0"
                            ")"
                            "WITH OIDS");
  const struct GNUNET_PQ_ExecuteStatement *cr;

  plugin->dbh = GNUNET_PQ_connect_with_cfg (plugin->cfg,
                                            "namecache-postgres");
  if (NULL == plugin->dbh)
    return GNUNET_SYSERR;
  if (GNUNET_YES ==
      GNUNET_CONFIGURATION_get_value_yesno (plugin->cfg,
                                            "namecache-postgres",
                                            "TEMPORARY_TABLE"))
  {
    cr = &es_temporary;
  }
  else
  {
    cr = &es_default;
  }

  {
    struct GNUNET_PQ_ExecuteStatement es[] = {
      *cr,
      GNUNET_PQ_make_try_execute (
        "CREATE INDEX ir_query_hash ON ns096blocks (query,expiration_time)"),
      GNUNET_PQ_make_try_execute (
        "CREATE INDEX ir_block_expiration ON ns096blocks (expiration_time)"),
      GNUNET_PQ_EXECUTE_STATEMENT_END
    };

    if (GNUNET_OK !=
        GNUNET_PQ_exec_statements (plugin->dbh,
                                   es))
    {
      PQfinish (plugin->dbh);
      plugin->dbh = NULL;
      return GNUNET_SYSERR;
    }
  }

  {
    struct GNUNET_PQ_PreparedStatement ps[] = {
      GNUNET_PQ_make_prepare ("cache_block",
                              "INSERT INTO ns096blocks (query, block, expiration_time) VALUES "
                              "($1, $2, $3)", 3),
      GNUNET_PQ_make_prepare ("expire_blocks",
                              "DELETE FROM ns096blocks WHERE expiration_time<$1",
                              1),
      GNUNET_PQ_make_prepare ("delete_block",
                              "DELETE FROM ns096blocks WHERE query=$1 AND expiration_time<=$2",
                              2),
      GNUNET_PQ_make_prepare ("lookup_block",
                              "SELECT block FROM ns096blocks WHERE query=$1"
                              " ORDER BY expiration_time DESC LIMIT 1", 1),
      GNUNET_PQ_PREPARED_STATEMENT_END
    };

    if (GNUNET_OK !=
        GNUNET_PQ_prepare_statements (plugin->dbh,
                                      ps))
    {
      PQfinish (plugin->dbh);
      plugin->dbh = NULL;
      return GNUNET_SYSERR;
    }
  }

  return GNUNET_OK;
}


/**
 * Removes any expired block.
 *
 * @param plugin the plugin
 */
static void
namecache_postgres_expire_blocks (struct Plugin *plugin)
{
  struct GNUNET_TIME_Absolute now = GNUNET_TIME_absolute_get ();
  struct GNUNET_PQ_QueryParam params[] = {
    GNUNET_PQ_query_param_absolute_time (&now),
    GNUNET_PQ_query_param_end
  };
  enum GNUNET_DB_QueryStatus res;

  res = GNUNET_PQ_eval_prepared_non_select (plugin->dbh,
                                            "expire_blocks",
                                            params);
  GNUNET_break (GNUNET_DB_STATUS_HARD_ERROR != res);
}


/**
 * Delete older block in the datastore.
 *
 * @param plugin the plugin
 * @param query query for the block
 * @param expiration_time how old does the block have to be for deletion
 */
static void
delete_old_block (struct Plugin *plugin,
                  const struct GNUNET_HashCode *query,
                  struct GNUNET_TIME_AbsoluteNBO expiration_time)
{
  struct GNUNET_PQ_QueryParam params[] = {
    GNUNET_PQ_query_param_auto_from_type (query),
    GNUNET_PQ_query_param_absolute_time_nbo (&expiration_time),
    GNUNET_PQ_query_param_end
  };
  enum GNUNET_DB_QueryStatus res;

  res = GNUNET_PQ_eval_prepared_non_select (plugin->dbh,
                                            "delete_block",
                                            params);
  GNUNET_break (GNUNET_DB_STATUS_HARD_ERROR != res);
}


/**
 * Cache a block in the datastore.
 *
 * @param cls closure (internal context for the plugin)
 * @param block block to cache
 * @return #GNUNET_OK on success, else #GNUNET_SYSERR
 */
static int
namecache_postgres_cache_block (void *cls,
                                const struct GNUNET_GNSRECORD_Block *block)
{
  struct Plugin *plugin = cls;
  struct GNUNET_HashCode query;
  size_t block_size = ntohl (block->purpose.size)
                      + sizeof(struct GNUNET_CRYPTO_EcdsaPublicKey)
                      + sizeof(struct GNUNET_CRYPTO_EcdsaSignature);
  struct GNUNET_PQ_QueryParam params[] = {
    GNUNET_PQ_query_param_auto_from_type (&query),
    GNUNET_PQ_query_param_fixed_size (block, block_size),
    GNUNET_PQ_query_param_absolute_time_nbo (&block->expiration_time),
    GNUNET_PQ_query_param_end
  };
  enum GNUNET_DB_QueryStatus res;

  namecache_postgres_expire_blocks (plugin);
  GNUNET_CRYPTO_hash (&block->derived_key,
                      sizeof(struct GNUNET_CRYPTO_EcdsaPublicKey),
                      &query);
  if (block_size > 64 * 65536)
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  delete_old_block (plugin,
                    &query,
                    block->expiration_time);

  res = GNUNET_PQ_eval_prepared_non_select (plugin->dbh,
                                            "cache_block",
                                            params);
  if (0 > res)
    return GNUNET_SYSERR;
  return GNUNET_OK;
}


/**
 * Get the block for a particular zone and label in the
 * datastore.  Will return at most one result to the iterator.
 *
 * @param cls closure (internal context for the plugin)
 * @param query hash of public key derived from the zone and the label
 * @param iter function to call with the result
 * @param iter_cls closure for @a iter
 * @return #GNUNET_OK on success, #GNUNET_NO if there were no results, #GNUNET_SYSERR on error
 */
static int
namecache_postgres_lookup_block (void *cls,
                                 const struct GNUNET_HashCode *query,
                                 GNUNET_NAMECACHE_BlockCallback iter,
                                 void *iter_cls)
{
  struct Plugin *plugin = cls;
  size_t bsize;
  struct GNUNET_GNSRECORD_Block *block;
  struct GNUNET_PQ_QueryParam params[] = {
    GNUNET_PQ_query_param_auto_from_type (query),
    GNUNET_PQ_query_param_end
  };
  struct GNUNET_PQ_ResultSpec rs[] = {
    GNUNET_PQ_result_spec_variable_size ("block",
                                         (void **) &block,
                                         &bsize),
    GNUNET_PQ_result_spec_end
  };
  enum GNUNET_DB_QueryStatus res;

  res = GNUNET_PQ_eval_prepared_singleton_select (plugin->dbh,
                                                  "lookup_block",
                                                  params,
                                                  rs);
  if (0 > res)
  {
    LOG (GNUNET_ERROR_TYPE_WARNING,
         "Failing lookup block in namecache (postgres error)\n");
    return GNUNET_SYSERR;
  }
  if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == res)
  {
    /* no result */
    LOG (GNUNET_ERROR_TYPE_DEBUG,
         "Ending iteration (no more results)\n");
    return GNUNET_NO;
  }
  if ((bsize < sizeof(*block)) ||
      (bsize != ntohl (block->purpose.size)
       + sizeof(struct GNUNET_CRYPTO_EcdsaPublicKey)
       + sizeof(struct GNUNET_CRYPTO_EcdsaSignature)))
  {
    GNUNET_break (0);
    LOG (GNUNET_ERROR_TYPE_DEBUG,
         "Failing lookup (corrupt block)\n");
    GNUNET_PQ_cleanup_result (rs);
    return GNUNET_SYSERR;
  }
  iter (iter_cls,
        block);
  GNUNET_PQ_cleanup_result (rs);
  return GNUNET_OK;
}


/**
 * Shutdown database connection and associate data
 * structures.
 *
 * @param plugin the plugin context (state for this module)
 */
static void
database_shutdown (struct Plugin *plugin)
{
  PQfinish (plugin->dbh);
  plugin->dbh = NULL;
}


/**
 * Entry point for the plugin.
 *
 * @param cls the `struct GNUNET_NAMECACHE_PluginEnvironment *`
 * @return NULL on error, otherwise the plugin context
 */
void *
libgnunet_plugin_namecache_postgres_init (void *cls)
{
  static struct Plugin plugin;
  const struct GNUNET_CONFIGURATION_Handle *cfg = cls;
  struct GNUNET_NAMECACHE_PluginFunctions *api;

  if (NULL != plugin.cfg)
    return NULL;                /* can only initialize once! */
  memset (&plugin, 0, sizeof(struct Plugin));
  plugin.cfg = cfg;
  if (GNUNET_OK != database_setup (&plugin))
  {
    database_shutdown (&plugin);
    return NULL;
  }
  api = GNUNET_new (struct GNUNET_NAMECACHE_PluginFunctions);
  api->cls = &plugin;
  api->cache_block = &namecache_postgres_cache_block;
  api->lookup_block = &namecache_postgres_lookup_block;
  LOG (GNUNET_ERROR_TYPE_INFO,
       "Postgres namecache plugin running\n");
  return api;
}


/**
 * Exit point from the plugin.
 *
 * @param cls the plugin context (as returned by "init")
 * @return always NULL
 */
void *
libgnunet_plugin_namecache_postgres_done (void *cls)
{
  struct GNUNET_NAMECACHE_PluginFunctions *api = cls;
  struct Plugin *plugin = api->cls;

  database_shutdown (plugin);
  plugin->cfg = NULL;
  GNUNET_free (api);
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Postgres namecache plugin is finished\n");
  return NULL;
}

/* end of plugin_namecache_postgres.c */