summaryrefslogtreecommitdiff
path: root/src/dht/gnunet-service-dht_datacache.c
blob: 36047d56194238148f12fa3bef5b81fc645ecf5f (plain)
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
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
/*
     This file is part of GNUnet.
     Copyright (C) 2009, 2010, 2011, 2015, 2017 GNUnet e.V.

     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., 51 Franklin Street, Fifth Floor,
     Boston, MA 02110-1301, USA.
*/
/**
 * @file dht/gnunet-service-dht_datacache.c
 * @brief GNUnet DHT service's datacache integration
 * @author Christian Grothoff
 * @author Nathan Evans
 */
#include "platform.h"
#include "gnunet_datacache_lib.h"
#include "gnunet-service-dht_datacache.h"
#include "gnunet-service-dht_routing.h"
#include "gnunet-service-dht.h"

#define LOG(kind,...) GNUNET_log_from (kind, "dht-dhtcache",__VA_ARGS__)

/**
 * How many "closest" results to we return for migration when
 * asked (at most)?
 */
#define NUM_CLOSEST 42

/**
 * Handle to the datacache service (for inserting/retrieving data)
 */
static struct GNUNET_DATACACHE_Handle *datacache;


/**
 * Handle a datum we've received from another peer.  Cache if
 * possible.
 *
 * @param expiration when will the reply expire
 * @param key the query this reply is for
 * @param put_path_length number of peers in @a put_path
 * @param put_path path the reply took on put
 * @param type type of the reply
 * @param data_size number of bytes in @a data
 * @param data application payload data
 */
void
GDS_DATACACHE_handle_put (struct GNUNET_TIME_Absolute expiration,
                          const struct GNUNET_HashCode *key,
                          unsigned int put_path_length,
                          const struct GNUNET_PeerIdentity *put_path,
                          enum GNUNET_BLOCK_Type type,
                          size_t data_size,
                          const void *data)
{
  int r;

  if (NULL == datacache)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                _("%s request received, but have no datacache!\n"), "PUT");
    return;
  }
  if (data_size >= GNUNET_MAX_MESSAGE_SIZE)
  {
    GNUNET_break (0);
    return;
  }
  /* Put size is actual data size plus struct overhead plus path length (if any) */
  GNUNET_STATISTICS_update (GDS_stats,
                            gettext_noop ("# ITEMS stored in datacache"), 1,
                            GNUNET_NO);
  r = GNUNET_DATACACHE_put (datacache,
                            key,
                            data_size,
                            data,
                            type,
                            expiration,
                            put_path_length,
                            put_path);
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "DATACACHE PUT for key %s [%u] completed (%d) after %u hops\n",
       GNUNET_h2s (key),
       data_size,
       r,
       put_path_length);
}


/**
 * Context containing information about a GET request.
 */
struct GetRequestContext
{
  /**
   * extended query (see gnunet_block_lib.h).
   */
  const void *xquery;

  /**
   * The key this request was about
   */
  struct GNUNET_HashCode key;

  /**
   * Block group to use to evaluate replies (updated)
   */
  struct GNUNET_BLOCK_Group *bg;

  /**
   * Function to call on results.
   */
  GDS_DATACACHE_GetCallback gc;

  /**
   * Closure for @e gc.
   */
  void *gc_cls;

  /**
   * Number of bytes in xquery.
   */
  size_t xquery_size;

  /**
   * Return value to give back.
   */
  enum GNUNET_BLOCK_EvaluationResult eval;

};


/**
 * Iterator for local get request results,
 *
 * @param cls closure for iterator, a `struct GetRequestContext`
 * @param exp when does this value expire?
 * @param key the key this data is stored under
 * @param data_size the size of the data identified by key
 * @param data the actual data
 * @param type the type of the @a data
 * @param put_path_length number of peers in @a put_path
 * @param put_path path the reply took on put
 * @return #GNUNET_OK to continue iteration, anything else
 * to stop iteration.
 */
static int
datacache_get_iterator (void *cls,
                        const struct GNUNET_HashCode *key,
                        size_t data_size,
                        const char *data,
                        enum GNUNET_BLOCK_Type type,
			struct GNUNET_TIME_Absolute exp,
			unsigned int put_path_length,
			const struct GNUNET_PeerIdentity *put_path)
{
  static char non_null;
  struct GetRequestContext *ctx = cls;
  enum GNUNET_BLOCK_EvaluationResult eval;

  if ( (NULL == data) &&
       (0 == data_size) )
    data = &non_null; /* point anywhere, but not to NULL */

  eval
    = GNUNET_BLOCK_evaluate (GDS_block_context,
                             type,
                             ctx->bg,
                             GNUNET_BLOCK_EO_LOCAL_SKIP_CRYPTO,
                             key,
                             ctx->xquery,
                             ctx->xquery_size,
                             data,
                             data_size);
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Found reply for query %s in datacache, evaluation result is %d\n",
       GNUNET_h2s (key),
       (int) eval);
  ctx->eval = eval;
  switch (eval)
  {
  case GNUNET_BLOCK_EVALUATION_OK_MORE:
  case GNUNET_BLOCK_EVALUATION_OK_LAST:
    /* forward to local clients */
    GNUNET_STATISTICS_update (GDS_stats,
                              gettext_noop
                              ("# Good RESULTS found in datacache"), 1,
                              GNUNET_NO);
    ctx->gc (ctx->gc_cls,
             type,
             exp,
             key,
             put_path_length, put_path,
             0, NULL,
             data, data_size);
    break;
  case GNUNET_BLOCK_EVALUATION_OK_DUPLICATE:
    GNUNET_STATISTICS_update (GDS_stats,
                              gettext_noop ("# Duplicate RESULTS found in datacache"),
                              1,
                              GNUNET_NO);
    break;
  case GNUNET_BLOCK_EVALUATION_RESULT_INVALID:
    GNUNET_STATISTICS_update (GDS_stats,
                              gettext_noop ("# Invalid RESULTS found in datacache"),
                              1,
                              GNUNET_NO);
    break;
  case GNUNET_BLOCK_EVALUATION_RESULT_IRRELEVANT:
    GNUNET_STATISTICS_update (GDS_stats,
                              gettext_noop ("# Irrelevant RESULTS found in datacache"),
                              1,
                              GNUNET_NO);
    break;
  case GNUNET_BLOCK_EVALUATION_REQUEST_VALID:
    GNUNET_break (0);
    break;
  case GNUNET_BLOCK_EVALUATION_REQUEST_INVALID:
    GNUNET_break_op (0);
    return GNUNET_SYSERR;
  case GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED:
    GNUNET_STATISTICS_update (GDS_stats,
                              gettext_noop ("# Unsupported RESULTS found in datacache"),
                              1,
                              GNUNET_NO);
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                _("Unsupported block type (%u) in local response!\n"),
                type);
    break;
  }
  return (eval == GNUNET_BLOCK_EVALUATION_OK_LAST) ? GNUNET_NO : GNUNET_OK;
}


/**
 * Handle a GET request we've received from another peer.
 *
 * @param key the query
 * @param type requested data type
 * @param xquery extended query
 * @param xquery_size number of bytes in @a xquery
 * @param bg block group to use for reply evaluation
 * @param gc function to call on the results
 * @param gc_cls closure for @a gc
 * @return evaluation result for the local replies
 */
enum GNUNET_BLOCK_EvaluationResult
GDS_DATACACHE_handle_get (const struct GNUNET_HashCode *key,
                          enum GNUNET_BLOCK_Type type,
                          const void *xquery,
                          size_t xquery_size,
                          struct GNUNET_BLOCK_Group *bg,
                          GDS_DATACACHE_GetCallback gc,
                          void *gc_cls)
{
  struct GetRequestContext ctx;
  unsigned int r;

  if (NULL == datacache)
    return GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
  GNUNET_STATISTICS_update (GDS_stats,
                            gettext_noop ("# GET requests given to datacache"),
                            1,
                            GNUNET_NO);
  ctx.eval = GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
  ctx.key = *key;
  ctx.xquery = xquery;
  ctx.xquery_size = xquery_size;
  ctx.bg = bg;
  ctx.gc = gc;
  ctx.gc_cls = gc_cls;
  r = GNUNET_DATACACHE_get (datacache,
                            key,
                            type,
                            &datacache_get_iterator,
                            &ctx);
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "DATACACHE GET for key %s completed (%d). %u results found.\n",
       GNUNET_h2s (key),
       ctx.eval,
       r);
  return ctx.eval;
}


/**
 * Function called with a random element from the datacache.
 * Stores the key in the closure.
 *
 * @param cls a `struct GNUNET_HashCode *`, where to store the @a key
 * @param key key for the content
 * @param data_size number of bytes in @a data
 * @param data content stored
 * @param type type of the content
 * @param exp when will the content expire?
 * @param path_info_len number of entries in @a path_info
 * @param path_info a path through the network
 * @return #GNUNET_OK to continue iterating, #GNUNET_SYSERR to abort
 */
static int
datacache_random_iterator (void *cls,
                           const struct GNUNET_HashCode *key,
                           size_t data_size,
                           const char *data,
                           enum GNUNET_BLOCK_Type type,
                           struct GNUNET_TIME_Absolute exp,
                           unsigned int path_info_len,
                           const struct GNUNET_PeerIdentity *path_info)
{
  struct GNUNET_HashCode *dest = cls;

  *dest = *key;
  return GNUNET_OK; /* should actually not matter which we return */
}


/**
 * Obtain a random key from the datacache.
 * Used by Whanau for load-balancing.
 *
 * @param[out] key where to store the key of a random element,
 *             randomized by PRNG if datacache is empty
 * @return #GNUNET_OK on success, #GNUNET_SYSERR if the datacache is empty
 */
int
GDS_DATACACHE_get_random_key (struct GNUNET_HashCode *key)
{
  if (0 ==
      GNUNET_DATACACHE_get_random (datacache,
                                   &datacache_random_iterator,
                                   key))
  {
    /* randomize key in this case */
    GNUNET_CRYPTO_hash_create_random (GNUNET_CRYPTO_QUALITY_NONCE,
                                      key);
    return GNUNET_SYSERR;
  }
  return GNUNET_OK;
}


/**
 * Closure for #datacache_get_successors_iterator().
 */
struct SuccContext
{
  /**
   * Function to call on the result
   */
  GDS_DATACACHE_SuccessorCallback cb;

  /**
   * Closure for @e cb.
   */
  void *cb_cls;
};


/**
 * Iterator for local get request results,
 *
 * @param cls closure with the `struct GNUNET_HashCode *` with the trail ID
 * @param key the key this data is stored under
 * @param size the size of the data identified by key
 * @param data the actual data
 * @param type the type of the data
 * @param exp when does this value expire?
 * @param put_path_length number of peers in @a put_path
 * @param put_path path the reply took on put
 * @return #GNUNET_OK to continue iteration, anything else
 * to stop iteration.
 */
static int
datacache_get_successors_iterator (void *cls,
                                   const struct GNUNET_HashCode *key,
                                   size_t size,
                                   const char *data,
                                   enum GNUNET_BLOCK_Type type,
                                   struct GNUNET_TIME_Absolute exp,
                                   unsigned int put_path_length,
                                   const struct GNUNET_PeerIdentity *put_path)
{
  const struct SuccContext *sc = cls;

  /* NOTE: The datacache currently does not store the RO from
     the original 'put', so we don't know the 'correct' option
     at this point anymore.  Thus, we conservatively assume
     that recording is desired (for now). */
  sc->cb (sc->cb_cls,
          GNUNET_DHT_RO_RECORD_ROUTE,
          key,
          type,
          put_path_length, put_path,
          exp,
          data,
          size);
  return GNUNET_OK;
}


/**
 * Handle a request for data close to a key that we have received from
 * another peer.
 *
 * @param key the location at which the peer is looking for data that is close
 * @param cb function to call with the result
 * @param cb_cls closure for @a cb
 */
void
GDS_DATACACHE_get_successors (const struct GNUNET_HashCode *key,
                              GDS_DATACACHE_SuccessorCallback cb,
                              void *cb_cls)
{
  struct SuccContext sc;

  sc.cb = cb;
  sc.cb_cls = cb_cls;
  (void) GNUNET_DATACACHE_get_closest (datacache,
                                       key,
                                       NUM_CLOSEST,
                                       &datacache_get_successors_iterator,
                                       &sc);
}


/**
 * Initialize datacache subsystem.
 */
void
GDS_DATACACHE_init ()
{
  datacache = GNUNET_DATACACHE_create (GDS_cfg, "dhtcache");
}


/**
 * Shutdown datacache subsystem.
 */
void
GDS_DATACACHE_done ()
{
  if (NULL != datacache)
  {
    GNUNET_DATACACHE_destroy (datacache);
    datacache = NULL;
  }
}


/* end of gnunet-service-dht_datacache.c */