summaryrefslogtreecommitdiff
path: root/src/namestore/gnunet-namestore-fcfsd.c
blob: 313aea6fc7e31e5a73f28ea5d5324e08a3ad0134 (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
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
/*
     This file is part of GNUnet.
     Copyright (C) 2012-2014 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 gnunet-namestore-fcfsd.c
 * @brief HTTP daemon that offers first-come-first-serve GNS domain registration
 * @author Christian Grothoff
 *
 * TODO:
 * - need to track active zone info requests so we can cancel them
 *   during shutdown, right?
 * - the code currently contains a 'race' between checking that the
 *   domain name is available and allocating it to the new public key
 *   (should this race be solved by namestore or by fcfsd?)
 * - nicer error reporting to browser
 */
#include "platform.h"
#include <microhttpd.h>
#include "gnunet_util_lib.h"
#include "gnunet_identity_service.h"
#include "gnunet_gnsrecord_lib.h"
#include "gnunet_namestore_service.h"
#include "gnunet_mhd_compat.h"

/**
 * Invalid method page.
 */
#define METHOD_ERROR \
  "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\"><html lang=\"en\" xmlns=\"http://www.w3.org/1999/xhtml\"><html><head><title>Illegal request</title></head><body>Go away.</body></html>"

/**
 * Front page. (/)
 */
#define MAIN_PAGE \
  "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\"><html lang=\"en\" xmlns=\"http://www.w3.org/1999/xhtml\"><html><head><title>GNUnet FCFS Authority Name Registration Service</title></head><body><form action=\"S\" method=\"post\">What is your desired domain name? (at most 63 lowercase characters, no dots allowed.) <input type=\"text\" name=\"domain\" /> <p> What is your public key? (Copy from gnunet-setup.) <input type=\"text\" name=\"pkey\" /> <input type=\"submit\" value=\"Next\" /><br/><a href=./Zoneinfo> List of all registered names </a></body></html>"

/**
 * Second page (/S)
 */
#define SUBMIT_PAGE \
  "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\"><html lang=\"en\" xmlns=\"http://www.w3.org/1999/xhtml\"><html><head><title>%s</title></head><body>%s</body></html>"

/**
 * Fcfs zoneinfo page (/Zoneinfo)
 */
#define ZONEINFO_PAGE \
  "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\"><html lang=\"en\" xmlns=\"http://www.w3.org/1999/xhtml\"><html><head><title>FCFS Zoneinfo</title></head><body><h1> FCFS Zoneinfo </h1><table border=\"1\"><th>name</th><th>PKEY</th>%s</table></body></html>"

#define FCFS_ZONEINFO_URL "/Zoneinfo"

/**
 * Mime type for HTML pages.
 */
#define MIME_HTML "text/html"

/**
 * Name of our cookie.
 */
#define COOKIE_NAME "namestore-fcfsd"

#define DEFAULT_ZONEINFO_BUFSIZE 2048

/**
 * Phases a request goes through.
 */
enum Phase
{
  /**
   * Start phase (parsing POST, checking).
   */
  RP_START = 0,

  /**
   * Lookup to see if the domain name is taken.
   */
  RP_LOOKUP,

  /**
   * Storing of the record.
   */
  RP_PUT,

  /**
   * We're done with success.
   */
  RP_SUCCESS,

  /**
   * Send failure message.
   */
  RP_FAIL
};


/**
 * Data kept per request.
 */
struct Request
{
  /**
   * Associated session.
   */
  // FIXME: struct Session *session;

  /**
   * Post processor handling form data (IF this is
   * a POST request).
   */
  struct MHD_PostProcessor *pp;

  /**
   * MHD Connection
   */
  struct MHD_Connection *con;
  /**
   * URL to serve in response to this POST (if this request
   * was a 'POST')
   */
  const char *post_url;

  /**
   * Active request with the namestore.
   */
  struct GNUNET_NAMESTORE_QueueEntry *qe;

  /**
   * Active lookup iterator
   * TODO: deprecate or fix lookup by label and use above member
   */
  struct GNUNET_NAMESTORE_ZoneIterator *lookup_it;
  /**
   * Active iteration with the namestore.
   */
  struct GNUNET_NAMESTORE_ZoneIterator *zi;

  /**
   * Current processing phase.
   */
  enum Phase phase;

  /**
   * Domain name submitted via form.
   */
  char domain_name[64];

  /**
   * Public key submitted via form.
   */
  char public_key[128];

  struct GNUNET_IDENTITY_PublicKey pub;
};

/**
 * Zoneinfo request
 */
struct ZoneinfoRequest
{
  /**
   * List iterator
   */
  struct GNUNET_NAMESTORE_ZoneIterator *list_it;

  /**
   * Buffer
   */
  char*zoneinfo;

  /**
   * Buffer length
   */
  size_t buf_len;

  /**
   * Buffer write offset
   */
  size_t write_offset;
};

/**
 * MHD daemon reference.
 */
static struct MHD_Daemon *httpd;

/**
 * Main HTTP task.
 */
static struct GNUNET_SCHEDULER_Task *httpd_task;

/**
 * Handle to the namestore.
 */
static struct GNUNET_NAMESTORE_Handle *ns;

/**
 * Private key for the fcfsd zone.
 */
static struct GNUNET_IDENTITY_PrivateKey fcfs_zone_pkey;

/**
 * Connection to identity service.
 */
static struct GNUNET_IDENTITY_Handle *identity;

/**
 * Zoneinfo page we currently use.
 */
static struct MHD_Response *info_page;

/**
 * Task that runs #update_zoneinfo_page peridicially.
 */
static struct GNUNET_SCHEDULER_Task *uzp_task;

/**
 * Request for our ego.
 */
static struct GNUNET_IDENTITY_Operation *id_op;

/**
 * Port we use for the HTTP server.
 */
static unsigned long long port;

/**
 * Name of the zone we manage.
 */
static char *zone;


/**
 * Task run whenever HTTP server operations are pending.
 *
 * @param cls unused
 */
static void
do_httpd (void *cls);


/**
 * Schedule task to run MHD server now.
 */
static void
run_httpd_now ()
{
  if (NULL != httpd_task)
  {
    GNUNET_SCHEDULER_cancel (httpd_task);
    httpd_task = NULL;
  }
  httpd_task = GNUNET_SCHEDULER_add_now (&do_httpd, NULL);
}


/**
 * Create fresh version of zone information.
 */
static void
update_zoneinfo_page (void *cls);


/**
 * Function called on error in zone iteration.
 */
static void
zone_iteration_error (void *cls)
{
  struct ZoneinfoRequest *zr = cls;

  zr->list_it = NULL;
  GNUNET_free (zr->zoneinfo);
  GNUNET_SCHEDULER_cancel (uzp_task);
  uzp_task = GNUNET_SCHEDULER_add_now (&update_zoneinfo_page,
                                       NULL);
}


/**
 * Function called once the zone iteration is done.
 */
static void
zone_iteration_end (void *cls)
{
  struct ZoneinfoRequest *zr = cls;
  struct MHD_Response *response;
  char*full_page;

  zr->list_it = NULL;

  /* return static form */
  GNUNET_asprintf (&full_page,
                   ZONEINFO_PAGE,
                   zr->zoneinfo);
  response = MHD_create_response_from_buffer (strlen (full_page),
                                              (void *) full_page,
                                              MHD_RESPMEM_MUST_FREE);
  MHD_add_response_header (response,
                           MHD_HTTP_HEADER_CONTENT_TYPE,
                           MIME_HTML);
  MHD_destroy_response (info_page);
  info_page = response;
  GNUNET_free (zr->zoneinfo);
}


/**
 * Process a record that was stored in the namestore, adding
 * the information to the HTML.
 *
 * @param cls closure with the `struct ZoneinfoRequest *`
 * @param zone_key private key of the zone; NULL on disconnect
 * @param name label of the records; NULL on disconnect
 * @param rd_len number of entries in @a rd array, 0 if label was deleted
 * @param rd array of records with data to store
 */
static void
iterate_cb (void *cls,
            const struct GNUNET_IDENTITY_PrivateKey *zone_key,
            const char *name,
            unsigned int rd_len,
            const struct GNUNET_GNSRECORD_Data *rd)
{
  struct ZoneinfoRequest *zr = cls;
  size_t bytes_free;
  char*pkey;
  char*new_buf;

  (void) zone_key;
  if (1 != rd_len)
  {
    GNUNET_NAMESTORE_zone_iterator_next (zr->list_it,
                                         1);
    return;
  }

  if ((GNUNET_GNSRECORD_TYPE_PKEY != rd->record_type) &&
      (GNUNET_GNSRECORD_TYPE_EDKEY != rd->record_type))
  {
    GNUNET_NAMESTORE_zone_iterator_next (zr->list_it,
                                         1);
    return;
  }

  bytes_free = zr->buf_len - zr->write_offset;
  pkey = GNUNET_GNSRECORD_value_to_string (rd->record_type,
                                           rd->data,
                                           rd->data_size);
  if (NULL == pkey)
  {
    GNUNET_break (0);
    GNUNET_NAMESTORE_zone_iterator_next (zr->list_it,
                                         1);
    return;
  }
  if (bytes_free < (strlen (name) + strlen (pkey) + 40))
  {
    new_buf = GNUNET_malloc (zr->buf_len * 2);
    GNUNET_memcpy (new_buf, zr->zoneinfo, zr->write_offset);
    GNUNET_free (zr->zoneinfo);
    zr->zoneinfo = new_buf;
    zr->buf_len *= 2;
  }
  sprintf (zr->zoneinfo + zr->write_offset,
           "<tr><td>%s</td><td>%s</td></tr>",
           name,
           pkey);
  zr->write_offset = strlen (zr->zoneinfo);
  GNUNET_NAMESTORE_zone_iterator_next (zr->list_it,
                                       1);
  GNUNET_free (pkey);
}


/**
 * Handler that returns FCFS zoneinfo page.
 *
 * @param connection connection to use
 */
static int
serve_zoneinfo_page (struct MHD_Connection *connection)
{
  return MHD_queue_response (connection,
                             MHD_HTTP_OK,
                             info_page);
}


/**
 * Create fresh version of zone information.
 */
static void
update_zoneinfo_page (void *cls)
{
  static struct ZoneinfoRequest zr;

  (void) cls;
  uzp_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
                                           &update_zoneinfo_page,
                                           NULL);
  if (NULL != zr.list_it)
    return;
  zr.zoneinfo = GNUNET_malloc (DEFAULT_ZONEINFO_BUFSIZE);
  zr.buf_len = DEFAULT_ZONEINFO_BUFSIZE;
  zr.write_offset = 0;
  zr.list_it = GNUNET_NAMESTORE_zone_iteration_start (ns,
                                                      &fcfs_zone_pkey,
                                                      &zone_iteration_error,
                                                      &zr,
                                                      &iterate_cb,
                                                      &zr,
                                                      &zone_iteration_end,
                                                      &zr);
}


/**
 * Handler that returns a simple static HTTP page.
 *
 * @param connection connection to use
 * @return #MHD_YES on success
 */
static int
serve_main_page (struct MHD_Connection *connection)
{
  int ret;
  struct MHD_Response *response;

  /* return static form */
  response = MHD_create_response_from_buffer (strlen (MAIN_PAGE),
                                              (void *) MAIN_PAGE,
                                              MHD_RESPMEM_PERSISTENT);
  MHD_add_response_header (response,
                           MHD_HTTP_HEADER_CONTENT_TYPE,
                           MIME_HTML);
  ret = MHD_queue_response (connection,
                            MHD_HTTP_OK,
                            response);
  MHD_destroy_response (response);
  return ret;
}


/**
 * Send the 'SUBMIT_PAGE'.
 *
 * @param info information string to send to the user
 * @param request request information
 * @param connection connection to use
 */
static int
fill_s_reply (const char *info,
              struct Request *request,
              struct MHD_Connection *connection)
{
  int ret;
  char *reply;
  struct MHD_Response *response;

  (void) request;
  GNUNET_asprintf (&reply,
                   SUBMIT_PAGE,
                   info,
                   info);
  /* return static form */
  response = MHD_create_response_from_buffer (strlen (reply),
                                              (void *) reply,
                                              MHD_RESPMEM_MUST_FREE);
  MHD_add_response_header (response,
                           MHD_HTTP_HEADER_CONTENT_TYPE,
                           MIME_HTML);
  ret = MHD_queue_response (connection,
                            MHD_HTTP_OK,
                            response);
  MHD_destroy_response (response);
  return ret;
}


/**
 * Iterator over key-value pairs where the value
 * maybe made available in increments and/or may
 * not be zero-terminated.  Used for processing
 * POST data.
 *
 * @param cls user-specified closure
 * @param kind type of the value
 * @param key 0-terminated key for the value
 * @param filename name of the uploaded file, NULL if not known
 * @param content_type mime-type of the data, NULL if not known
 * @param transfer_encoding encoding of the data, NULL if not known
 * @param data pointer to size bytes of data at the
 *              specified offset
 * @param off offset of data in the overall value
 * @param size number of bytes in data available
 * @return #MHD_YES to continue iterating,
 *         #MHD_NO to abort the iteration
 */
static MHD_RESULT
post_iterator (void *cls,
               enum MHD_ValueKind kind,
               const char *key,
               const char *filename,
               const char *content_type,
               const char *transfer_encoding,
               const char *data,
               uint64_t off,
               size_t size)
{
  struct Request *request = cls;

  (void) kind;
  (void) filename;
  (void) content_type;
  (void) transfer_encoding;
  if (0 == strcmp ("domain", key))
  {
    if (size + off >= sizeof(request->domain_name))
      size = sizeof(request->domain_name) - off - 1;
    GNUNET_memcpy (&request->domain_name[off],
                   data,
                   size);
    request->domain_name[size + off] = '\0';
    return MHD_YES;
  }
  if (0 == strcmp ("pkey", key))
  {
    if (size + off >= sizeof(request->public_key))
      size = sizeof(request->public_key) - off - 1;
    GNUNET_memcpy (&request->public_key[off],
                   data,
                   size);
    request->public_key[size + off] = '\0';
    return MHD_YES;
  }
  GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
              _ ("Unsupported form value `%s'\n"),
              key);
  return MHD_YES;
}


/**
 * Continuation called to notify client about result of the
 * operation.
 *
 * @param cls closure
 * @param success #GNUNET_SYSERR on failure (including timeout/queue drop/failure to validate)
 *                #GNUNET_NO if content was already there
 *                #GNUNET_YES (or other positive value) on success
 * @param emsg NULL on success, otherwise an error message
 */
static void
put_continuation (void *cls,
                  int32_t success,
                  const char *emsg)
{
  struct Request *request = cls;

  request->qe = NULL;
  if (0 >= success)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                _ ("Failed to create record for domain `%s': %s\n"),
                request->domain_name,
                emsg);
    request->phase = RP_FAIL;
  }
  else
    request->phase = RP_SUCCESS;
  MHD_resume_connection (request->con);
  run_httpd_now ();
}


/**
 * Function called if we had an error in zone-to-name mapping.
 */
static void
zone_to_name_error (void *cls)
{
  struct Request *request = cls;

  GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
              _ ("Error when mapping zone to name\n"));
  request->phase = RP_FAIL;
  MHD_resume_connection (request->con);
  run_httpd_now ();
}


/**
 * Test if a name mapping was found, if so, refuse.  If not, initiate storing of the record.
 *
 * @param cls closure
 * @param zone_key public key of the zone
 * @param name name that is being mapped (at most 255 characters long)
 * @param rd_count number of entries in @a rd array
 * @param rd array of records with data to store
 */
static void
zone_to_name_cb (void *cls,
                 const struct GNUNET_IDENTITY_PrivateKey *zone_key,
                 const char *name,
                 unsigned int rd_count,
                 const struct GNUNET_GNSRECORD_Data *rd)
{
  struct Request *request = cls;
  struct GNUNET_GNSRECORD_Data r;
  char *rdata;

  (void) rd;
  (void) zone_key;
  request->qe = NULL;
  if (0 != rd_count)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                _ ("Found existing name `%s' for the given key\n"),
                name);
    request->phase = RP_FAIL;
    MHD_resume_connection (request->con);
    run_httpd_now ();
    return;
  }
  if (GNUNET_OK != GNUNET_GNSRECORD_data_from_identity (&request->pub,
                                                        &rdata,
                                                        &r.data_size,
                                                        &r.record_type))
  {
    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                _ ("Error creating record data.\n"));
    request->phase = RP_FAIL;
    MHD_resume_connection (request->con);
    run_httpd_now ();
    return;
  }

  r.data = rdata;
  r.expiration_time = UINT64_MAX;
  r.flags = GNUNET_GNSRECORD_RF_NONE;
  request->qe = GNUNET_NAMESTORE_records_store (ns,
                                                &fcfs_zone_pkey,
                                                request->domain_name,
                                                1, &r,
                                                &put_continuation,
                                                request);
  GNUNET_free (rdata);
}


/**
 * We encountered an error in the name lookup.
 */
static void
lookup_it_error (void *cls)
{
  struct Request *request = cls;

  MHD_resume_connection (request->con);
  request->qe = NULL;
  request->phase = RP_FAIL;
  run_httpd_now ();
}


/**
 * We got a block back from the namestore.  Decrypt it
 * and continue to process the result.
 *
 * @param cls the 'struct Request' we are processing
 * @param zonekey private key of the zone; NULL on disconnect
 * @param label label of the records; NULL on disconnect
 * @param rd_count number of entries in @a rd array, 0 if label was deleted
 * @param rd array of records with data to store
 */
static void
lookup_it_processor (void *cls,
                     const struct GNUNET_IDENTITY_PrivateKey *zonekey,
                     const char *label,
                     unsigned int rd_count,
                     const struct GNUNET_GNSRECORD_Data *rd)
{
  struct Request *request = cls;

  (void) label;
  (void) rd;
  (void) zonekey;
  if (0 == strcmp (label, request->domain_name))
  {
    GNUNET_break (0 != rd_count);
    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                _ ("Found %u existing records for domain `%s'\n"),
                rd_count,
                request->domain_name);
    request->phase = RP_FAIL;
  }
  GNUNET_NAMESTORE_zone_iterator_next (request->lookup_it, 1);
}


static void
lookup_it_finished (void *cls)
{
  struct Request *request = cls;

  if (RP_FAIL == request->phase)
  {
    MHD_resume_connection (request->con);
    run_httpd_now ();
    return;
  }
  if (GNUNET_OK !=
      GNUNET_IDENTITY_public_key_from_string (request->public_key,
                                              &request->pub))
  {
    GNUNET_break (0);
    request->phase = RP_FAIL;
    MHD_resume_connection (request->con);
    run_httpd_now ();
    return;
  }
  request->qe = GNUNET_NAMESTORE_zone_to_name (ns,
                                               &fcfs_zone_pkey,
                                               &request->pub,
                                               &zone_to_name_error,
                                               request,
                                               &zone_to_name_cb,
                                               request);
}


/**
 * Main MHD callback for handling requests.
 *
 * @param cls unused
 * @param connection MHD connection handle
 * @param url the requested url
 * @param method the HTTP method used ("GET", "PUT", etc.)
 * @param version the HTTP version string ("HTTP/1.1" for version 1.1, etc.)
 * @param upload_data the data being uploaded (excluding HEADERS,
 *        for a POST that fits into memory and that is encoded
 *        with a supported encoding, the POST data will NOT be
 *        given in upload_data and is instead available as
 *        part of MHD_get_connection_values; very large POST
 *        data *will* be made available incrementally in
 *        upload_data)
 * @param upload_data_size set initially to the size of the
 *        @a upload_data provided; the method must update this
 *        value to the number of bytes NOT processed;
 * @param ptr pointer to location where we store the 'struct Request'
 * @return #MHD_YES if the connection was handled successfully,
 *         #MHD_NO if the socket must be closed due to a serious
 *         error while handling the request
 */
static MHD_RESULT
create_response (void *cls,
                 struct MHD_Connection *connection,
                 const char *url,
                 const char *method,
                 const char *version,
                 const char *upload_data,
                 size_t *upload_data_size,
                 void **ptr)
{
  struct MHD_Response *response;
  struct Request *request;
  struct GNUNET_IDENTITY_PublicKey pub;
  MHD_RESULT ret;

  (void) cls;
  (void) version;
  if ((0 == strcmp (method, MHD_HTTP_METHOD_GET)) ||
      (0 == strcmp (method, MHD_HTTP_METHOD_HEAD)))
  {
    if (0 == strcmp (url, FCFS_ZONEINFO_URL))
      ret = serve_zoneinfo_page (connection);
    else
      ret = serve_main_page (connection);
    if (ret != MHD_YES)
      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                  _ ("Failed to create page for `%s'\n"),
                  url);
    return ret;
  }
  if (0 == strcmp (method, MHD_HTTP_METHOD_POST))
  {
    request = *ptr;
    if (NULL == request)
    {
      request = GNUNET_new (struct Request);
      request->con = connection;
      *ptr = request;
      request->pp = MHD_create_post_processor (connection,
                                               1024,
                                               &post_iterator,
                                               request);
      if (NULL == request->pp)
      {
        GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                    _ ("Failed to setup post processor for `%s'\n"),
                    url);
        return MHD_NO;       /* internal error */
      }
      return MHD_YES;
    }
    if (NULL != request->pp)
    {
      /* evaluate POST data */
      MHD_post_process (request->pp,
                        upload_data,
                        *upload_data_size);
      if (0 != *upload_data_size)
      {
        *upload_data_size = 0;
        return MHD_YES;
      }
      /* done with POST data, serve response */
      MHD_destroy_post_processor (request->pp);
      request->pp = NULL;
    }
    if (GNUNET_OK !=
        GNUNET_IDENTITY_public_key_from_string (request->public_key,
                                                &pub))
    {
      /* parse error */
      return fill_s_reply ("Failed to parse given public key",
                           request, connection);
    }
    switch (request->phase)
    {
    case RP_START:
      if (NULL != strchr (request->domain_name, (int) '.'))
      {
        GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                    _ ("Domain name must not contain `.'\n"));
        request->phase = RP_FAIL;
        return fill_s_reply ("Domain name must not contain `.', sorry.",
                             request,
                             connection);
      }
      if (NULL != strchr (request->domain_name, (int) '+'))
      {
        GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                    _ ("Domain name must not contain `+'\n"));
        request->phase = RP_FAIL;
        return fill_s_reply ("Domain name must not contain `+', sorry.",
                             request, connection);
      }
      request->phase = RP_LOOKUP;
      MHD_suspend_connection (request->con);
      request->lookup_it
        = GNUNET_NAMESTORE_zone_iteration_start (ns,
                                                 &fcfs_zone_pkey,
                                                 &lookup_it_error,
                                                 request,
                                                 &lookup_it_processor,
                                                 request,
                                                 &lookup_it_finished,
                                                 request);
      break;

    case RP_LOOKUP:
      break;

    case RP_PUT:
      break;

    case RP_FAIL:
      return fill_s_reply ("Request failed, sorry.",
                           request, connection);

    case RP_SUCCESS:
      return fill_s_reply ("Success.",
                           request, connection);

    default:
      GNUNET_break (0);
      return MHD_NO;
    }
    return MHD_YES;   /* will have a reply later... */
  }
  /* unsupported HTTP method */
  response = MHD_create_response_from_buffer (strlen (METHOD_ERROR),
                                              (void *) METHOD_ERROR,
                                              MHD_RESPMEM_PERSISTENT);
  ret = MHD_queue_response (connection,
                            MHD_HTTP_NOT_ACCEPTABLE,
                            response);
  MHD_destroy_response (response);
  return ret;
}


/**
 * Callback called upon completion of a request.
 * Decrements session reference counter.
 *
 * @param cls not used
 * @param connection connection that completed
 * @param con_cls session handle
 * @param toe status code
 */
static void
request_completed_callback (void *cls,
                            struct MHD_Connection *connection,
                            void **con_cls,
                            enum MHD_RequestTerminationCode toe)
{
  struct Request *request = *con_cls;

  (void) cls;
  (void) connection;
  (void) toe;
  if (NULL == request)
    return;
  if (NULL != request->pp)
    MHD_destroy_post_processor (request->pp);
  if (NULL != request->qe)
    GNUNET_NAMESTORE_cancel (request->qe);
  GNUNET_free (request);
}


#define UNSIGNED_MHD_LONG_LONG unsigned MHD_LONG_LONG


/**
 * Schedule tasks to run MHD server.
 */
static void
run_httpd ()
{
  fd_set rs;
  fd_set ws;
  fd_set es;
  struct GNUNET_NETWORK_FDSet *wrs;
  struct GNUNET_NETWORK_FDSet *wws;
  struct GNUNET_NETWORK_FDSet *wes;
  int max;
  int haveto;
  UNSIGNED_MHD_LONG_LONG timeout;
  struct GNUNET_TIME_Relative tv;

  FD_ZERO (&rs);
  FD_ZERO (&ws);
  FD_ZERO (&es);
  wrs = GNUNET_NETWORK_fdset_create ();
  wes = GNUNET_NETWORK_fdset_create ();
  wws = GNUNET_NETWORK_fdset_create ();
  max = -1;
  GNUNET_assert (MHD_YES ==
                 MHD_get_fdset (httpd,
                                &rs,
                                &ws,
                                &es,
                                &max));
  haveto = MHD_get_timeout (httpd,
                            &timeout);
  if (haveto == MHD_YES)
    tv.rel_value_us = (uint64_t) timeout * 1000LL;
  else
    tv = GNUNET_TIME_UNIT_FOREVER_REL;
  GNUNET_NETWORK_fdset_copy_native (wrs,
                                    &rs,
                                    max + 1);
  GNUNET_NETWORK_fdset_copy_native (wws,
                                    &ws,
                                    max + 1);
  GNUNET_NETWORK_fdset_copy_native (wes,
                                    &es,
                                    max + 1);
  httpd_task =
    GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_HIGH,
                                 tv,
                                 wrs,
                                 wws,
                                 &do_httpd,
                                 NULL);
  GNUNET_NETWORK_fdset_destroy (wrs);
  GNUNET_NETWORK_fdset_destroy (wws);
  GNUNET_NETWORK_fdset_destroy (wes);
}


/**
 * Task run whenever HTTP server operations are pending.
 *
 * @param cls unused
 */
static void
do_httpd (void *cls)
{
  (void) cls;
  httpd_task = NULL;
  MHD_run (httpd);
  run_httpd ();
}


/**
 * Task run on shutdown.  Cleans up everything.
 *
 * @param cls unused
 */
static void
do_shutdown (void *cls)
{
  (void) cls;
  if (NULL != httpd_task)
  {
    GNUNET_SCHEDULER_cancel (httpd_task);
    httpd_task = NULL;
  }
  if (NULL != uzp_task)
  {
    GNUNET_SCHEDULER_cancel (uzp_task);
    uzp_task = NULL;
  }
  if (NULL != ns)
  {
    GNUNET_NAMESTORE_disconnect (ns);
    ns = NULL;
  }
  if (NULL != httpd)
  {
    MHD_stop_daemon (httpd);
    httpd = NULL;
  }
  if (NULL != id_op)
  {
    GNUNET_IDENTITY_cancel (id_op);
    id_op = NULL;
  }
  if (NULL != identity)
  {
    GNUNET_IDENTITY_disconnect (identity);
    identity = NULL;
  }
}


/**
 * Method called to inform about the egos of this peer.
 *
 * When used with #GNUNET_IDENTITY_create or #GNUNET_IDENTITY_get, this
 * function is only called ONCE, and 'NULL' being passed in @a ego does
 * indicate an error (for example because name is taken or no default value is
 * known).  If @a ego is non-NULL and if '*ctx' is set in those callbacks, the
 * value WILL be passed to a subsequent call to the identity callback of
 * #GNUNET_IDENTITY_connect (if that one was not NULL).
 *
 * @param cls closure, NULL
 * @param ego ego handle
 * @param ctx context for application to store data for this ego
 *                 (during the lifetime of this process, initially NULL)
 * @param name name assigned by the user for this ego,
 *                   NULL if the user just deleted the ego and it
 *                   must thus no longer be used
 */
static void
identity_cb (void *cls,
             struct GNUNET_IDENTITY_Ego *ego,
             void **ctx,
             const char *name)
{
  int options;

  (void) cls;
  (void) ctx;
  if (NULL == name)
    return;
  if (0 != strcmp (name,
                   zone))
    return;
  if (NULL == ego)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                _ ("No ego configured for `fcfsd` subsystem\n"));
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
  fcfs_zone_pkey = *GNUNET_IDENTITY_ego_get_private_key (ego);

  options = MHD_USE_DUAL_STACK | MHD_USE_DEBUG | MHD_ALLOW_SUSPEND_RESUME;
  do
  {
    httpd = MHD_start_daemon (options,
                              (uint16_t) port,
                              NULL, NULL,
                              &create_response, NULL,
                              MHD_OPTION_CONNECTION_LIMIT, (unsigned int) 128,
                              MHD_OPTION_PER_IP_CONNECTION_LIMIT, (unsigned
                                                                   int) 1,
                              MHD_OPTION_CONNECTION_TIMEOUT, (unsigned int) 16,
                              MHD_OPTION_CONNECTION_MEMORY_LIMIT, (size_t) (4
                                                                            *
                                                                            1024),
                              MHD_OPTION_NOTIFY_COMPLETED,
                              &request_completed_callback, NULL,
                              MHD_OPTION_END);
    if (MHD_USE_DEBUG == options)
      break;
    options = MHD_USE_DEBUG;
  }
  while (NULL == httpd);
  if (NULL == httpd)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                _ ("Failed to start HTTP server\n"));
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
  run_httpd ();
}


/**
 * Main function that will be run.
 *
 * @param cls closure
 * @param args remaining command-line arguments
 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
 * @param cfg configuration
 */
static void
run (void *cls,
     char *const *args,
     const char *cfgfile,
     const struct GNUNET_CONFIGURATION_Handle *cfg)
{
  (void) cls;
  (void) args;
  (void) cfgfile;
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_number (cfg,
                                             "fcfsd",
                                             "HTTPPORT",
                                             &port))
  {
    GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
                               "fcfsd", "HTTPPORT");
    return;
  }
  ns = GNUNET_NAMESTORE_connect (cfg);
  if (NULL == ns)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                _ ("Failed to connect to namestore\n"));
    return;
  }
  identity = GNUNET_IDENTITY_connect (cfg,
                                      &identity_cb,
                                      NULL);
  if (NULL == identity)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                _ ("Failed to connect to identity\n"));
    return;
  }
  uzp_task = GNUNET_SCHEDULER_add_now (&update_zoneinfo_page,
                                       NULL);
  GNUNET_SCHEDULER_add_shutdown (&do_shutdown,
                                 NULL);
}


/**
 * The main function for the fcfs daemon.
 *
 * @param argc number of arguments from the command line
 * @param argv command line arguments
 * @return 0 ok, 1 on error
 */
int
main (int argc,
      char *const *argv)
{
  struct GNUNET_GETOPT_CommandLineOption options[] = {
    GNUNET_GETOPT_option_mandatory
      (GNUNET_GETOPT_option_string ('z',
                                    "zone",
                                    "EGO",
                                    gettext_noop (
                                      "name of the zone that is to be managed by FCFSD"),
                                    &zone)),
    GNUNET_GETOPT_OPTION_END
  };
  int ret;

  if (GNUNET_OK !=
      GNUNET_STRINGS_get_utf8_args (argc, argv,
                                    &argc, &argv))
    return 2;

  GNUNET_log_setup ("fcfsd",
                    "WARNING",
                    NULL);
  ret =
    (GNUNET_OK ==
     GNUNET_PROGRAM_run (argc,
                         argv,
                         "gnunet-namestore-fcfsd",
                         _ (
                           "GNU Name System First Come First Serve name registration service"),
                         options,
                         &run, NULL)) ? 0 : 1;
  GNUNET_free_nz ((void *) argv);
  // FIXME
  // GNUNET_CRYPTO_ecdsa_key_clear (&fcfs_zone_pkey);
  return ret;
}


/* end of gnunet-namestore-fcfsd.c */