aboutsummaryrefslogtreecommitdiff
path: root/src/pq/db_pq.c
blob: 220ce9f949a5c5e5d46d7ccb3cd813f18410c4cb (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
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
/*
  This file is part of TALER
  Copyright (C) 2014, 2015 Christian Grothoff (and other contributing authors)

  TALER 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.

  TALER 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
  TALER; see the file COPYING.  If not, If not, see <http://www.gnu.org/licenses/>
*/
/**
 * @file pq/db_pq.c
 * @brief helper functions for libpq (PostGres) interactions
 * @author Sree Harsha Totakura <sreeharsha@totakura.in>
 * @author Florian Dold
 * @author Christian Grothoff
 */
#include "platform.h"
#include <gnunet/gnunet_util_lib.h>
#include "taler_pq_lib.h"


/**
 * Execute a prepared statement.
 *
 * @param db_conn database connection
 * @param name name of the prepared statement
 * @param params parameters to the statement
 * @return postgres result
 */
PGresult *
TALER_PQ_exec_prepared (PGconn *db_conn,
                        const char *name,
                        const struct TALER_PQ_QueryParam *params)
{
  unsigned int len;
  unsigned int i;

  /* count the number of parameters */
  i = 0;
  len = 0;
  while (TALER_PQ_QF_END != params[i].format)
  {
    const struct TALER_PQ_QueryParam *x = &params[i];

    switch (x->format)
    {
    case TALER_PQ_QF_FIXED_BLOB:
    case TALER_PQ_QF_VARSIZE_BLOB:
      len++;
      break;
    case TALER_PQ_QF_AMOUNT_NBO:
    case TALER_PQ_QF_AMOUNT:
      len += 3;
      break;
    case TALER_PQ_QF_RSA_PUBLIC_KEY:
    case TALER_PQ_QF_RSA_SIGNATURE:
    case TALER_PQ_QF_TIME_ABSOLUTE:
      len++;
      break;
    default:
      /* format not supported */
      GNUNET_assert (0);
      break;
    }
    i++;
  }

  /* new scope to allow stack allocation without alloca */
  {
    /* Scratch buffer for temporary storage */
    void *scratch[len];
    /* Parameter array we are building for the query */
    void *param_values[len];
    int param_lengths[len];
    int param_formats[len];
    unsigned int off;
    /* How many entries in the scratch buffer are in use? */
    unsigned int soff;
    PGresult *res;

    i = 0;
    off = 0;
    soff = 0;
    while (TALER_PQ_QF_END != params[i].format)
    {
      const struct TALER_PQ_QueryParam *x = &params[i];

      switch (x->format)
      {
      case TALER_PQ_QF_FIXED_BLOB:
      case TALER_PQ_QF_VARSIZE_BLOB:
        param_values[off] = (void *) x->data;
        param_lengths[off] = x->size;
        param_formats[off] = 1;
        off++;
        break;
      case TALER_PQ_QF_AMOUNT_NBO:
        {
          const struct TALER_Amount *amount = x->data;

          param_values[off] = (void *) &amount->value;
          param_lengths[off] = sizeof (amount->value);
          param_formats[off] = 1;
          off++;
          param_values[off] = (void *) &amount->fraction;
          param_lengths[off] = sizeof (amount->fraction);
          param_formats[off] = 1;
          off++;
          param_values[off] = (void *) amount->currency;
          param_lengths[off] = strlen (amount->currency);
          param_formats[off] = 1;
          off++;
        }
        break;
      case TALER_PQ_QF_AMOUNT:
        {
          const struct TALER_Amount *amount_hbo = x->data;
          struct TALER_AmountNBO *amount;

          amount = GNUNET_new (struct TALER_AmountNBO);
          scratch[soff++] = amount;
          TALER_amount_hton (amount,
                             amount_hbo);
          param_values[off] = (void *) &amount->value;
          param_lengths[off] = sizeof (amount->value);
          param_formats[off] = 1;
          off++;
          param_values[off] = (void *) &amount->fraction;
          param_lengths[off] = sizeof (amount->fraction);
          param_formats[off] = 1;
          off++;
          param_values[off] = (void *) amount->currency;
          param_lengths[off] = strlen (amount->currency);
          param_formats[off] = 1;
          off++;
        }
        break;
      case TALER_PQ_QF_RSA_PUBLIC_KEY:
        {
          const struct GNUNET_CRYPTO_rsa_PublicKey *rsa = x->data;
          char *buf;
          size_t buf_size;

          buf_size = GNUNET_CRYPTO_rsa_public_key_encode (rsa,
                                                          &buf);
          scratch[soff++] = buf;
          param_values[off] = (void *) buf;
          param_lengths[off] = buf_size - 1; /* DB doesn't like the trailing \0 */
          param_formats[off] = 1;
          off++;
        }
        break;
      case TALER_PQ_QF_RSA_SIGNATURE:
        {
          const struct GNUNET_CRYPTO_rsa_Signature *sig = x->data;
          char *buf;
          size_t buf_size;

          buf_size = GNUNET_CRYPTO_rsa_signature_encode (sig,
                                                         &buf);
          scratch[soff++] = buf;
          param_values[off] = (void *) buf;
          param_lengths[off] = buf_size - 1; /* DB doesn't like the trailing \0 */
          param_formats[off] = 1;
          off++;
        }
        break;
      case TALER_PQ_QF_TIME_ABSOLUTE:
        {
          const struct GNUNET_TIME_Absolute *at_hbo = x->data;
          struct GNUNET_TIME_AbsoluteNBO *at_nbo;
	  
          at_nbo = GNUNET_new (struct GNUNET_TIME_AbsoluteNBO);
          scratch[soff++] = at_nbo;
	  /* FIXME: this does not work for 'forever' as PQ uses 63-bit integers;
	     should check and handle! (Need testcase!) */
          *at_nbo = GNUNET_TIME_absolute_hton (*at_hbo);
          param_values[off] = (void *) at_nbo;
          param_lengths[off] = sizeof (struct GNUNET_TIME_AbsoluteNBO);
          param_formats[off] = 1;
          off++;
        }
        break;
      default:
        /* format not supported */
        GNUNET_assert (0);
        break;
      }
      i++;
    }
    GNUNET_assert (off == len);
    res = PQexecPrepared (db_conn,
                          name,
                          len,
                          (const char **) param_values,
                          param_lengths,
                          param_formats,
                          1);
    for (off = 0; off < soff; off++)
      GNUNET_free (scratch[off]);
    return res;
  }
}


/**
 * Free all memory that was allocated in @a rs during
 * #TALER_PQ_extract_result().
 *
 * @param rs reult specification to clean up
 */
void
TALER_PQ_cleanup_result (struct TALER_PQ_ResultSpec *rs)
{
  unsigned int i;

  for (i=0; TALER_PQ_RF_END != rs[i].format; i++)
  {
    switch (rs[i].format)
    {
    case TALER_PQ_RF_VARSIZE_BLOB:
      if (NULL != rs[i].dst)
      {
        GNUNET_free (rs[i].dst);
        rs[i].dst = NULL;
        *rs[i].result_size = 0;
      }
      break;
    case TALER_PQ_RF_RSA_PUBLIC_KEY:
      if (NULL != rs[i].dst)
      {
        GNUNET_CRYPTO_rsa_public_key_free (rs[i].dst);
        rs[i].dst = NULL;
      }
      break;
    case TALER_PQ_RF_RSA_SIGNATURE:
      if (NULL != rs[i].dst)
      {
        GNUNET_CRYPTO_rsa_signature_free (rs[i].dst);
        rs[i].dst = NULL;
      }
      break;
    default:
      break;
    }
  }
}


/**
 * Extract results from a query result according to the given specification.
 * If colums are NULL, the destination is not modified, and #GNUNET_NO
 * is returned.
 *
 * @param result result to process
 * @param[in|out] rs result specification to extract for
 * @param row row from the result to extract
 * @return
 *   #GNUNET_YES if all results could be extracted
 *   #GNUNET_NO if at least one result was NULL
 *   #GNUNET_SYSERR if a result was invalid (non-existing field)
 */
int
TALER_PQ_extract_result (PGresult *result,
                         struct TALER_PQ_ResultSpec *rs,
                         int row)
{
  unsigned int i;
  int had_null = GNUNET_NO;

  for (i=0; TALER_PQ_RF_END != rs[i].format; i++)
  {
    struct TALER_PQ_ResultSpec *spec;

    spec = &rs[i];
    switch (spec->format)
    {
    case TALER_PQ_RF_FIXED_BLOB:
    case TALER_PQ_RF_VARSIZE_BLOB:
      {
        size_t len;
        const char *res;
        void *dst;
        int fnum;

        fnum = PQfnumber (result,
                          spec->fname);
        if (fnum < 0)
        {
          GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                      "Field `%s' does not exist in result\n",
                      spec->fname);
          return GNUNET_SYSERR;
        }
        if (PQgetisnull (result,
                         row,
                         fnum))
        {
          had_null = GNUNET_YES;
          continue;
        }

        /* if a field is null, continue but
         * remember that we now return a different result */
        len = PQgetlength (result,
                           row,
                           fnum);
        if ( (0 != spec->dst_size) &&
             (spec->dst_size != len) )
        {
          GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                      "Field `%s' has wrong size (got %u, expected %u)\n",
                      spec->fname,
                      (unsigned int) len,
                      (unsigned int) spec->dst_size);
          TALER_PQ_cleanup_result (rs);
          return GNUNET_SYSERR;
        }
        res = PQgetvalue (result,
                          row,
                          fnum);
        GNUNET_assert (NULL != res);
        if (0 == spec->dst_size)
        {
          if (NULL != spec->result_size)
            *spec->result_size = len;
          spec->dst_size = len;
          dst = GNUNET_malloc (len);
          *((void **) spec->dst) = dst;
        }
        else
          dst = spec->dst;
        memcpy (dst,
                res,
                len);
        break;
      }
    case TALER_PQ_RF_AMOUNT_NBO:
      {
        char *val_name;
        char *frac_name;
        char *curr_name;
        const char *name = spec->fname;
        int ret;

        GNUNET_assert (NULL != spec->dst);
        GNUNET_assert (sizeof (struct TALER_AmountNBO) ==
                       spec->dst_size);
        GNUNET_asprintf (&val_name,
                         "%s_val",
                         name);
        GNUNET_asprintf (&frac_name,
                         "%s_frac",
                         name);
        GNUNET_asprintf (&curr_name,
                         "%s_curr",
                         name);
        ret = TALER_PQ_extract_amount_nbo (result,
                                           row,
                                           val_name,
                                           frac_name,
                                           curr_name,
                                           spec->dst);
        GNUNET_free (val_name);
        GNUNET_free (frac_name);
        GNUNET_free (curr_name);
        if (GNUNET_SYSERR == ret)
          return GNUNET_SYSERR;
        if (GNUNET_OK != ret)
          had_null = GNUNET_YES;
        break;
      }
    case TALER_PQ_RF_AMOUNT:
      {
        char *val_name;
        char *frac_name;
        char *curr_name;
        const char *name = spec->fname;
        int ret;

        GNUNET_assert (NULL != spec->dst);
        GNUNET_assert (sizeof (struct TALER_Amount) ==
                       spec->dst_size);
        GNUNET_asprintf (&val_name,
                         "%s_val",
                         name);
        GNUNET_asprintf (&frac_name,
                         "%s_frac",
                         name);
        GNUNET_asprintf (&curr_name,
                         "%s_curr",
                         name);
        ret = TALER_PQ_extract_amount (result,
                                       row,
                                       val_name,
                                       frac_name,
                                       curr_name,
                                       spec->dst);
        GNUNET_free (val_name);
        GNUNET_free (frac_name);
        GNUNET_free (curr_name);
        if (GNUNET_SYSERR == ret)
          return GNUNET_SYSERR;
        if (GNUNET_OK != ret)
          had_null = GNUNET_YES;
        break;
      }
    case TALER_PQ_RF_RSA_PUBLIC_KEY:
      {
        struct GNUNET_CRYPTO_rsa_PublicKey **pk = spec->dst;
        size_t len;
        const char *res;
        int fnum;

	*pk = NULL;
        fnum = PQfnumber (result,
                          spec->fname);
        if (fnum < 0)
        {
          GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                      "Field `%s' does not exist in result\n",
                      spec->fname);
          return GNUNET_SYSERR;
        }
        if (PQgetisnull (result,
                         row,
                         fnum))
        {
          had_null = GNUNET_YES;
          continue;
        }

        /* if a field is null, continue but
         * remember that we now return a different result */
        len = PQgetlength (result,
                           row,
                           fnum);
        res = PQgetvalue (result,
                          row,
                          fnum);
        *pk = GNUNET_CRYPTO_rsa_public_key_decode (res,
                                                   len);
        if (NULL == *pk)
        {
          GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                      "Field `%s' contains bogus value (fails to decode)\n",
                      spec->fname);
          return GNUNET_SYSERR;
        }
        break;
      }
    case TALER_PQ_RF_RSA_SIGNATURE:
      {
        struct GNUNET_CRYPTO_rsa_Signature **sig = spec->dst;
        size_t len;
        const char *res;
        int fnum;

	*sig = NULL;
        fnum = PQfnumber (result,
                          spec->fname);
        if (fnum < 0)
        {
          GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                      "Field `%s' does not exist in result\n",
                      spec->fname);
          return GNUNET_SYSERR;
        }
        if (PQgetisnull (result,
                         row,
                         fnum))
        {
          had_null = GNUNET_YES;
          continue;
        }

        /* if a field is null, continue but
         * remember that we now return a different result */
        len = PQgetlength (result,
                           row,
                           fnum);
        res = PQgetvalue (result,
                          row,
                          fnum);
        *sig = GNUNET_CRYPTO_rsa_signature_decode (res,
                                                   len);
        if (NULL == *sig)
        {
          GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                      "Field `%s' contains bogus value (fails to decode)\n",
                      spec->fname);
          return GNUNET_SYSERR;
        }
        break;
      }
    case TALER_PQ_RF_TIME_ABSOLUTE:
      {
        struct GNUNET_TIME_Absolute *dst = spec->dst;
	const struct GNUNET_TIME_AbsoluteNBO *res;
	int fnum;

        fnum = PQfnumber (result,
                          spec->fname);
        if (fnum < 0)
        {
          GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                      "Field `%s' does not exist in result\n",
                      spec->fname);
          return GNUNET_SYSERR;
        }
        if (PQgetisnull (result,
                         row,
                         fnum))
        {
          had_null = GNUNET_YES;
          continue;
        }
        GNUNET_assert (NULL != dst);
        GNUNET_assert (sizeof (struct GNUNET_TIME_AbsoluteNBO) ==
                       spec->dst_size);
        res = (const struct GNUNET_TIME_AbsoluteNBO *)
	  PQgetvalue (result,
		      row,
		      fnum);
	/* FIXME: this does not work for 'forever' as PQ uses 63-bit integers;
	   should check and handle! (Need testcase!) */
	*dst = GNUNET_TIME_absolute_ntoh (*res);
        break;
      }

    default:
      GNUNET_assert (0);
      break;
    }
  }
  if (GNUNET_YES == had_null)
    return GNUNET_NO;
  return GNUNET_YES;
}


/**
 * Extract a currency amount from a query result according to the
 * given specification.
 *
 * @param result the result to extract the amount from
 * @param row which row of the result to extract the amount from (needed as results can have multiple rows)
 * @param val_name name of the column with the amount's "value", must include the substring "_val".
 * @param frac_name name of the column with the amount's "fractional" value, must include the substring "_frac".
 * @param curr_name name of the column with the amount's currency name, must include the substring "_curr".
 * @param[out] r_amount_nbo where to store the amount, in network byte order
 * @return
 *   #GNUNET_YES if all results could be extracted
 *   #GNUNET_NO if at least one result was NULL
 *   #GNUNET_SYSERR if a result was invalid (non-existing field)
 */
int
TALER_PQ_extract_amount_nbo (PGresult *result,
                             int row,
                             const char *val_name,
                             const char *frac_name,
                             const char *curr_name,
                             struct TALER_AmountNBO *r_amount_nbo)
{
  int val_num;
  int frac_num;
  int curr_num;
  int len;

  /* These checks are simply to check that clients obey by our naming
     conventions, and not for any functional reason */
  GNUNET_assert (NULL !=
                 strstr (val_name,
                         "_val"));
  GNUNET_assert (NULL !=
                 strstr (frac_name,
                         "_frac"));
  GNUNET_assert (NULL !=
                 strstr (curr_name,
                         "_curr"));
  /* Set return value to invalid in case we don't finish */
  memset (r_amount_nbo,
          0,
          sizeof (struct TALER_AmountNBO));
  val_num = PQfnumber (result,
                       val_name);
  frac_num = PQfnumber (result,
                        frac_name);
  curr_num = PQfnumber (result,
                        curr_name);
  if ( (val_num < 0) ||
       (frac_num < 0) ||
       (curr_num < 0) )
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  if ( (PQgetisnull (result,
                     row,
                     val_num)) ||
       (PQgetisnull (result,
                     row,
                     frac_num)) ||
       (PQgetisnull (result,
                     row,
                     curr_num)) )
  {
    GNUNET_break (0);
    return GNUNET_NO;
  }
  /* Note that Postgres stores value in NBO internally,
     so no conversion needed in this case */
  r_amount_nbo->value = *(uint64_t *) PQgetvalue (result,
                                                  row,
                                                  val_num);
  r_amount_nbo->fraction = *(uint32_t *) PQgetvalue (result,
                                                     row,
                                                     frac_num);
  len = GNUNET_MIN (TALER_CURRENCY_LEN - 1,
                    PQgetlength (result,
                                 row,
                                 curr_num));
  memcpy (r_amount_nbo->currency,
          PQgetvalue (result,
                      row,
                      curr_num),
          len);
  return GNUNET_OK;
}


/**
 * Extract a currency amount from a query result according to the
 * given specification.
 *
 * @param result the result to extract the amount from
 * @param row which row of the result to extract the amount from (needed as
 *          results can have multiple rows)
 * @param val_name name of the column with the amount's "value", must include
 *          the substring "_val".
 * @param frac_name name of the column with the amount's "fractional" value,
 *          must include the substring "_frac".
 * @param curr_name name of the column with the amount's currency name, must
 *          include the substring "_curr".
 * @param[out] r_amount where to store the amount, in host byte order
 * @return
 *   #GNUNET_YES if all results could be extracted
 *   #GNUNET_NO if at least one result was NULL
 *   #GNUNET_SYSERR if a result was invalid (non-existing field)
 */
int
TALER_PQ_extract_amount (PGresult *result,
                         int row,
                         const char *val_name,
                         const char *frac_name,
                         const char *curr_name,
                         struct TALER_Amount *r_amount)
{
  struct TALER_AmountNBO amount_nbo;
  int ret;

  ret = TALER_PQ_extract_amount_nbo (result,
                                     row,
                                     val_name,
                                     frac_name,
                                     curr_name,
                                     &amount_nbo);
  TALER_amount_ntoh (r_amount,
                     &amount_nbo);
  return ret;
}


/* end of pq/db_pq.c */