src/gns/gnunet-service-gns.c

   1 /*
   2      This file is part of GNUnet.
   3      (C) 2011-2013 Christian Grothoff (and other contributing authors)
   4
   5      GNUnet is free software; you can redistribute it and/or modify
   6      it under the terms of the GNU General Public License as published
   7      by the Free Software Foundation; either version 3, or (at your
   8      option) any later version.
   9
  10      GNUnet is distributed in the hope that it will be useful, but
  11      WITHOUT ANY WARRANTY; without even the implied warranty of
  12      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13      General Public License for more details.
  14
  15      You should have received a copy of the GNU General Public License
  16      along with GNUnet; see the file COPYING.  If not, write to the
  17      Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18      Boston, MA 02111-1307, USA.
  19 */
  20 /**
  21  * @file gns/gnunet-service-gns.c
  22  * @brief GNUnet GNS service
  23  * @author Martin Schanzenbach
  24  * @author Christian Grothoff
  25  *
  26  * TODO:
  27  * - perform conversion of relative expiration times to absolute time
  28  *   when going to DHT!
  29  */
  30 #include "platform.h"
  31 #include "gnunet_util_lib.h"
  32 #include "gnunet_transport_service.h"
  33 #include "gnunet_dns_service.h"
  34 #include "gnunet_dnsparser_lib.h"
  35 #include "gnunet_dht_service.h"
  36 #include "gnunet_namestore_service.h"
  37 #include "gnunet_gns_service.h"
  38 #include "gnunet_statistics_service.h"
  39 #include "gns.h"
  40 #include "gns_common.h"
  41 #include "gnunet-service-gns_resolver.h"
  42 #include "gnunet-service-gns_interceptor.h"
  43 #include "gnunet_protocols.h"
  44
  45 /**
  46  * The initial interval in milliseconds btween puts in
  47  * a zone iteration
  48  */
  49 #define INITIAL_PUT_INTERVAL GNUNET_TIME_UNIT_MILLISECONDS
  50
  51 /**
  52  * The upper bound for the zone iteration interval in milliseconds
  53  */
  54 #define MINIMUM_ZONE_ITERATION_INTERVAL GNUNET_TIME_UNIT_SECONDS
  55
  56 /**
  57  * The default put interval for the zone iteration. In case
  58  * no option is found
  59  */
  60 #define DEFAULT_ZONE_PUBLISH_TIME_WINDOW GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 4)
  61
  62 /**
  63  * The factor the current zone iteration interval is divided by for each
  64  * additional new record
  65  */
  66 #define LATE_ITERATION_SPEEDUP_FACTOR 2
  67
  68 /**
  69  * How long until a DHT PUT attempt should time out?
  70  */
  71 #define DHT_OPERATION_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 60)
  72
  73 /**
  74  * What replication level do we use for DHT PUT operations?
  75  */
  76 #define DHT_GNS_REPLICATION_LEVEL 5
  77
  78
  79 /**
  80  * Handle to a lookup operation from api
  81  */
  82 struct ClientLookupHandle
  83 {
  84
  85   /**
  86    * We keep these in a DLL.
  87    */
  88   struct ClientLookupHandle *next;
  89
  90   /**
  91    * We keep these in a DLL.
  92    */
  93   struct ClientLookupHandle *prev;
  94
  95   /**
  96    * Handle to the requesting client
  97    */
  98   struct GNUNET_SERVER_Client *client;
  99
 100   /**
 101    * Active handle for the lookup.
 102    */
 103   struct GNS_ResolverHandle *lookup;
 104
 105   /**
 106    * request id
 107    */
 108   uint32_t request_id;
 109
 110 };
 111
 112
 113 /**
 114  * Our handle to the DHT
 115  */
 116 static struct GNUNET_DHT_Handle *dht_handle;
 117
 118 /**
 119  * Active DHT put operation (or NULL)
 120  */
 121 static struct GNUNET_DHT_PutHandle *active_put;
 122
 123 /**
 124  * Our handle to the namestore service
 125  */
 126 static struct GNUNET_NAMESTORE_Handle *namestore_handle;
 127
 128 /**
 129  * Handle to iterate over our authoritative zone in namestore
 130  */
 131 static struct GNUNET_NAMESTORE_ZoneIterator *namestore_iter;
 132
 133 /**
 134  * Our notification context.
 135  */
 136 static struct GNUNET_SERVER_NotificationContext *nc;
 137
 138 /**
 139  * Head of the DLL.
 140  */
 141 static struct ClientLookupHandle *clh_head;
 142
 143 /**
 144  * Tail of the DLL.
 145  */
 146 static struct ClientLookupHandle *clh_tail;
 147
 148 /**
 149  * Useful for zone update for DHT put
 150  */
 151 static unsigned long long num_public_records;
 152
 153 /**
 154  * Last seen record count
 155  */
 156 static unsigned long long last_num_public_records;
 157
 158 /**
 159  * Zone iteration PUT interval.
 160  */
 161 static struct GNUNET_TIME_Relative put_interval;
 162
 163 /**
 164  * Time window for zone iteration
 165  */
 166 static struct GNUNET_TIME_Relative zone_publish_time_window;
 167
 168 /**
 169  * zone publish task
 170  */
 171 static GNUNET_SCHEDULER_TaskIdentifier zone_publish_task;
 172
 173 /**
 174  * #GNUNET_YES if zone has never been published before
 175  */
 176 static int first_zone_iteration;
 177
 178 /**
 179  * The lookup timeout
 180  */
 181 static struct GNUNET_TIME_Relative default_lookup_timeout;
 182
 183 /**
 184  * #GNUNET_YES if ipv6 is supported
 185  */
 186 static int v6_enabled;
 187
 188 /**
 189  * #GNUNET_YES if ipv4 is supported
 190  */
 191 static int v4_enabled;
 192
 193 /**
 194  * Handle to the statistics service
 195  */
 196 static struct GNUNET_STATISTICS_Handle *statistics;
 197
 198
 199 /**
 200  * Task run during shutdown.
 201  *
 202  * @param cls unused
 203  * @param tc unused
 204  */
 205 static void
 206 shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 207 {
 208   struct ClientLookupHandle *clh;
 209
 210   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 211               "Shutting down!\n");
 212   GNUNET_SERVER_notification_context_destroy (nc);
 213   while (NULL != (clh = clh_head))
 214   {
 215     GNS_resolver_lookup_cancel (clh->lookup);
 216     GNUNET_CONTAINER_DLL_remove (clh_head, clh_tail, clh);
 217     GNUNET_free (clh);
 218   }
 219
 220   GNS_interceptor_done ();
 221   GNS_resolver_done ();
 222   if (NULL != statistics)
 223   {
 224     GNUNET_STATISTICS_destroy (statistics, GNUNET_NO);
 225     statistics = NULL;
 226   }
 227   if (GNUNET_SCHEDULER_NO_TASK != zone_publish_task)
 228   {
 229     GNUNET_SCHEDULER_cancel (zone_publish_task);
 230     zone_publish_task = GNUNET_SCHEDULER_NO_TASK;
 231   }
 232   if (NULL != namestore_iter)
 233   {
 234     GNUNET_NAMESTORE_zone_iteration_stop (namestore_iter);
 235     namestore_iter = NULL;
 236   }
 237   if (NULL != namestore_handle)
 238   {
 239     GNUNET_NAMESTORE_disconnect (namestore_handle);
 240     namestore_handle = NULL;
 241   }
 242   if (NULL != active_put)
 243   {
 244     GNUNET_DHT_put_cancel (active_put);
 245     active_put = NULL;
 246   }
 247   if (NULL != dht_handle)
 248   {
 249     GNUNET_DHT_disconnect (dht_handle);
 250     dht_handle = NULL;
 251   }
 252 }
 253
 254
 255 /**
 256  * Method called periodically that triggers iteration over authoritative records
 257  *
 258  * @param cls closure
 259  * @param tc task context
 260  */
 261 static void
 262 publish_zone_dht_next (void *cls,
 263                        const struct GNUNET_SCHEDULER_TaskContext *tc)
 264 {
 265   zone_publish_task = GNUNET_SCHEDULER_NO_TASK;
 266   GNUNET_NAMESTORE_zone_iterator_next (namestore_iter);
 267 }
 268
 269
 270 /**
 271  * Periodically iterate over our zone and store everything in dht
 272  *
 273  * @param cls NULL
 274  * @param tc task context
 275  */
 276 static void
 277 publish_zone_dht_start (void *cls,
 278                         const struct GNUNET_SCHEDULER_TaskContext *tc);
 279
 280
 281 /**
 282  * Continuation called from DHT once the PUT operation is done.
 283  *
 284  * @param cls closure, NULL
 285  * @param success #GNUNET_OK on success
 286  */
 287 static void
 288 dht_put_continuation (void *cls,
 289                       int success)
 290 {
 291   struct GNUNET_TIME_Relative next_put_interval;
 292
 293   num_public_records++;
 294   if ( (num_public_records > last_num_public_records) &&
 295        (GNUNET_NO == first_zone_iteration) )
 296   {
 297     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 298                 "Last record count was lower than current record count.  Reducing interval.\n");
 299     put_interval = GNUNET_TIME_relative_divide (zone_publish_time_window,
 300                                                 num_public_records);
 301     next_put_interval = GNUNET_TIME_relative_divide (put_interval,
 302                                                      LATE_ITERATION_SPEEDUP_FACTOR);
 303   }
 304   else
 305     next_put_interval = put_interval;
 306
 307   GNUNET_STATISTICS_set (statistics,
 308                          "Current zone iteration interval (ms)",
 309                          next_put_interval.rel_value_us / 1000LL,
 310                          GNUNET_NO);
 311   zone_publish_task = GNUNET_SCHEDULER_add_delayed (next_put_interval,
 312                                                     &publish_zone_dht_next,
 313                                                     NULL);
 314 }
 315
 316
 317 /**
 318  * Function used to put all records successively into the DHT.
 319  *
 320  * @param cls the closure (NULL)
 321  * @param key the private key of the authority (ours)
 322  * @param name the name of the records, NULL once the iteration is done
 323  * @param rd_count the number of records in @a rd
 324  * @param rd the record data
 325  */
 326 static void
 327 put_gns_record (void *cls,
 328                 const struct GNUNET_CRYPTO_EccPrivateKey *key,
 329                 const char *name,
 330                 unsigned int rd_count,
 331                 const struct GNUNET_NAMESTORE_RecordData *rd)
 332 {
 333   struct GNUNET_NAMESTORE_Block *block;
 334   struct GNUNET_HashCode query;
 335   struct GNUNET_TIME_Absolute expire;
 336   size_t block_size;
 337   struct GNUNET_NAMESTORE_RecordData rd_public[rd_count];
 338   unsigned int rd_public_count;
 339   unsigned int i;
 340
 341   if (NULL == name)
 342   {
 343     /* we're done with one iteration, calculate when to do the next one */
 344     namestore_iter = NULL;
 345     last_num_public_records = num_public_records;
 346     first_zone_iteration = GNUNET_NO;
 347     if (0 == num_public_records)
 348     {
 349       /**
 350        * If no records are known (startup) or none present
 351        * we can safely set the interval to the value for a single
 352        * record
 353        */
 354       put_interval = zone_publish_time_window;
 355       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG | GNUNET_ERROR_TYPE_BULK,
 356                   "No records in namestore database.\n");
 357     }
 358     else
 359     {
 360       put_interval = GNUNET_TIME_relative_divide (zone_publish_time_window,
 361                                                   num_public_records);
 362     }
 363     put_interval = GNUNET_TIME_relative_max (MINIMUM_ZONE_ITERATION_INTERVAL,
 364                                              put_interval);
 365
 366     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 367                 "Zone iteration finished. Adjusted zone iteration interval to %s\n",
 368                 GNUNET_STRINGS_relative_time_to_string (put_interval, GNUNET_YES));
 369     GNUNET_STATISTICS_set (statistics,
 370                            "Current zone iteration interval (in ms)",
 371                            put_interval.rel_value_us / 1000LL,
 372                            GNUNET_NO);
 373     GNUNET_STATISTICS_update (statistics,
 374                               "Number of zone iterations",
 375                               1,
 376                               GNUNET_NO);
 377     GNUNET_STATISTICS_set (statistics,
 378                            "Number of public records in DHT",
 379                            last_num_public_records,
 380                            GNUNET_NO);
 381     if (0 == num_public_records)
 382       zone_publish_task = GNUNET_SCHEDULER_add_delayed (put_interval,
 383                                                         &publish_zone_dht_start,
 384                                                         NULL);
 385     else
 386       zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_start,
 387                                                     NULL);
 388     return;
 389   }
 390
 391   /* filter out records that are not public! */
 392   rd_public_count = 0;
 393   for (i=0;i<rd_count;i++)
 394     if (0 == (rd[i].flags & (GNUNET_NAMESTORE_RF_PRIVATE |
 395                              GNUNET_NAMESTORE_RF_PENDING)))
 396       rd_public[rd_public_count++] = rd[i];
 397
 398
 399   /* We got a set of records to publish */
 400   if (0 == rd_public_count)
 401   {
 402     zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_next,
 403                                                    NULL);
 404     return;
 405   }
 406   expire = GNUNET_NAMESTORE_record_get_expiration_time (rd_public_count,
 407                                                         rd_public);
 408   block = GNUNET_NAMESTORE_block_create (key,
 409                                          expire,
 410                                          name,
 411                                          rd_public,
 412                                          rd_public_count);
 413   block_size = ntohl (block->purpose.size)
 414     + sizeof (struct GNUNET_CRYPTO_EccSignature)
 415     + sizeof (struct GNUNET_CRYPTO_EccPublicKey);
 416   GNUNET_NAMESTORE_query_from_private_key (key,
 417                                            name,
 418                                            &query);
 419
 420   active_put = GNUNET_DHT_put (dht_handle, &query,
 421                                DHT_GNS_REPLICATION_LEVEL,
 422                                GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE,
 423                                GNUNET_BLOCK_TYPE_GNS_NAMERECORD,
 424                                block_size,
 425                                block,
 426                                expire,
 427                                DHT_OPERATION_TIMEOUT,
 428                                &dht_put_continuation,
 429                                NULL);
 430   if (NULL == active_put)
 431   {
 432     GNUNET_break (0);
 433     dht_put_continuation (NULL, GNUNET_NO);
 434   }
 435   GNUNET_free (block);
 436 }
 437
 438
 439 /**
 440  * Periodically iterate over our zone and store everything in dht
 441  *
 442  * @param cls NULL
 443  * @param tc task context
 444  */
 445 static void
 446 publish_zone_dht_start (void *cls,
 447                         const struct GNUNET_SCHEDULER_TaskContext *tc)
 448 {
 449   zone_publish_task = GNUNET_SCHEDULER_NO_TASK;
 450
 451   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 452               "Scheduling DHT zone update!\n");
 453   /* start counting again */
 454   num_public_records = 0;
 455   namestore_iter = GNUNET_NAMESTORE_zone_iteration_start (namestore_handle,
 456                                                           NULL, /* All zones */
 457                                                           &put_gns_record,
 458                                                           NULL);
 459 }
 460
 461
 462 /* END DHT ZONE PROPAGATION */
 463
 464
 465 /**
 466  * Reply to client with the result from our lookup.
 467  *
 468  * @param cls the closure (our client lookup handle)
 469  * @param rd_count the number of records
 470  * @param rd the record data
 471  */
 472 static void
 473 send_lookup_response (void* cls,
 474                       uint32_t rd_count,
 475                       const struct GNUNET_NAMESTORE_RecordData *rd)
 476 {
 477   struct ClientLookupHandle *clh = cls;
 478   struct GNUNET_GNS_ClientLookupResultMessage *rmsg;
 479   size_t len;
 480
 481   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 482               "Sending `%s' message with %d results\n",
 483               "LOOKUP_RESULT",
 484               rd_count);
 485
 486   len = GNUNET_NAMESTORE_records_get_size (rd_count, rd);
 487   rmsg = GNUNET_malloc (len + sizeof (struct GNUNET_GNS_ClientLookupResultMessage));
 488   rmsg->header.type = htons (GNUNET_MESSAGE_TYPE_GNS_LOOKUP_RESULT);
 489   rmsg->header.size = htons (len + sizeof(struct GNUNET_GNS_ClientLookupResultMessage));
 490   rmsg->id = clh->request_id;
 491   rmsg->rd_count = htonl (rd_count);
 492   GNUNET_NAMESTORE_records_serialize (rd_count, rd, len,
 493                                       (char*) &rmsg[1]);
 494   GNUNET_SERVER_notification_context_unicast (nc,
 495                                               clh->client,
 496                                               &rmsg->header,
 497                                               GNUNET_NO);
 498   GNUNET_free (rmsg);
 499   GNUNET_SERVER_receive_done (clh->client,
 500                               GNUNET_OK);
 501   GNUNET_CONTAINER_DLL_remove (clh_head, clh_tail, clh);
 502   GNUNET_free (clh);
 503   GNUNET_STATISTICS_update (statistics,
 504                             "Completed lookups", 1,
 505                             GNUNET_NO);
 506   GNUNET_STATISTICS_update (statistics,
 507                             "Records resolved",
 508                             rd_count,
 509                             GNUNET_NO);
 510 }
 511
 512
 513 /**
 514  * Handle lookup requests from client
 515  *
 516  * @param cls the closure
 517  * @param client the client
 518  * @param message the message
 519  */
 520 static void
 521 handle_lookup (void *cls,
 522                struct GNUNET_SERVER_Client *client,
 523                const struct GNUNET_MessageHeader *message)
 524 {
 525   char name[GNUNET_DNSPARSER_MAX_NAME_LENGTH + 1];
 526   struct ClientLookupHandle *clh;
 527   char *nameptr = name;
 528   const char *utf_in;
 529   const struct GNUNET_CRYPTO_EccPrivateKey *key;
 530   uint16_t msg_size;
 531   const struct GNUNET_GNS_ClientLookupMessage *sh_msg;
 532
 533   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 534               "Received `%s' message\n",
 535               "LOOKUP");
 536   msg_size = ntohs (message->size);
 537   if (msg_size < sizeof (struct GNUNET_GNS_ClientLookupMessage))
 538   {
 539     GNUNET_break (0);
 540     GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
 541     return;
 542   }
 543   sh_msg = (const struct GNUNET_GNS_ClientLookupMessage *) message;
 544   GNUNET_SERVER_notification_context_add (nc, client);
 545   if (GNUNET_YES == ntohl (sh_msg->have_key))
 546     key = &sh_msg->shorten_key;
 547   else
 548     key = NULL;
 549   utf_in = (const char *) &sh_msg[1];
 550   if ( ('\0' != utf_in[msg_size - sizeof (struct GNUNET_GNS_ClientLookupMessage) - 1]) ||
 551        (strlen (utf_in) > GNUNET_DNSPARSER_MAX_NAME_LENGTH) )
 552   {
 553     GNUNET_break (0);
 554     GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
 555     return;
 556   }
 557   GNUNET_STRINGS_utf8_tolower (utf_in, &nameptr);
 558
 559   clh = GNUNET_new (struct ClientLookupHandle);
 560   GNUNET_SERVER_client_set_user_context (client, clh);
 561   GNUNET_CONTAINER_DLL_insert (clh_head, clh_tail, clh);
 562   clh->client = client;
 563   clh->request_id = sh_msg->id;
 564   if ( (GNUNET_DNSPARSER_TYPE_A == ntohl (sh_msg->type)) &&
 565        (GNUNET_OK != v4_enabled) )
 566   {
 567     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 568                 "LOOKUP: Query for A record but AF_INET not supported!");
 569     send_lookup_response (clh, 0, NULL);
 570     return;
 571   }
 572   if ( (GNUNET_DNSPARSER_TYPE_AAAA == ntohl (sh_msg->type)) &&
 573        (GNUNET_OK != v6_enabled) )
 574   {
 575     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 576                 "LOOKUP: Query for AAAA record but AF_INET6 not supported!");
 577     send_lookup_response (clh, 0, NULL);
 578     return;
 579   }
 580   clh->lookup = GNS_resolver_lookup (&sh_msg->zone,
 581                                      ntohl (sh_msg->type),
 582                                      name,
 583                                      key,
 584                                      ntohl (sh_msg->only_cached),
 585                                      &send_lookup_response, clh);
 586   GNUNET_STATISTICS_update (statistics,
 587                             "Lookup attempts",
 588                             1, GNUNET_NO);
 589 }
 590
 591
 592 /**
 593  * One of our clients disconnected, clean up after it.
 594  *
 595  * @param cls NULL
 596  * @param client the client that disconnected
 597  */
 598 static void
 599 notify_client_disconnect (void *cls,
 600                           struct GNUNET_SERVER_Client *client)
 601 {
 602   struct ClientLookupHandle *clh;
 603
 604   if (NULL == client)
 605     return;
 606   clh = GNUNET_SERVER_client_get_user_context (client, struct ClientLookupHandle);
 607   if (NULL == clh)
 608     return;
 609   GNS_resolver_lookup_cancel (clh->lookup);
 610   GNUNET_CONTAINER_DLL_remove (clh_head, clh_tail, clh);
 611   GNUNET_free (clh);
 612 }
 613
 614
 615 /**
 616  * Process GNS requests.
 617  *
 618  * @param cls closure
 619  * @param server the initialized server
 620  * @param c configuration to use
 621  */
 622 static void
 623 run (void *cls, struct GNUNET_SERVER_Handle *server,
 624      const struct GNUNET_CONFIGURATION_Handle *c)
 625 {
 626   static const struct GNUNET_SERVER_MessageHandler handlers[] = {
 627     { &handle_lookup, NULL, GNUNET_MESSAGE_TYPE_GNS_LOOKUP, 0},
 628     {NULL, NULL, 0, 0}
 629   };
 630   struct GNUNET_CRYPTO_EccPublicKey dns_root;
 631   unsigned long long max_parallel_bg_queries = 0;
 632   char *dns_root_name;
 633
 634   v6_enabled = GNUNET_NETWORK_test_pf (PF_INET6);
 635   v4_enabled = GNUNET_NETWORK_test_pf (PF_INET);
 636
 637   namestore_handle = GNUNET_NAMESTORE_connect (c);
 638   if (NULL == namestore_handle)
 639   {
 640     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 641                 _("Failed to connect to the namestore!\n"));
 642     GNUNET_SCHEDULER_shutdown ();
 643     return;
 644   }
 645
 646   put_interval = INITIAL_PUT_INTERVAL;
 647   zone_publish_time_window = DEFAULT_ZONE_PUBLISH_TIME_WINDOW;
 648
 649   if (GNUNET_OK ==
 650       GNUNET_CONFIGURATION_get_value_time (c, "gns",
 651                                            "ZONE_PUBLISH_TIME_WINDOW",
 652                                            &zone_publish_time_window))
 653   {
 654     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 655                 "Time window for zone iteration: %s\n",
 656                 GNUNET_STRINGS_relative_time_to_string (zone_publish_time_window, GNUNET_YES));
 657   }
 658   if (GNUNET_OK ==
 659       GNUNET_CONFIGURATION_get_value_number (c, "gns",
 660                                             "MAX_PARALLEL_BACKGROUND_QUERIES",
 661                                             &max_parallel_bg_queries))
 662   {
 663     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 664                 "Number of allowed parallel background queries: %llu\n",
 665                 max_parallel_bg_queries);
 666   }
 667
 668   if (GNUNET_OK ==
 669       GNUNET_CONFIGURATION_get_value_time (c, "gns",
 670                                            "DEFAULT_LOOKUP_TIMEOUT",
 671                                            &default_lookup_timeout))
 672   {
 673     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 674                 "Default lookup timeout: %s\n",
 675                 GNUNET_STRINGS_relative_time_to_string (default_lookup_timeout,
 676                                                         GNUNET_YES));
 677   }
 678
 679   dht_handle = GNUNET_DHT_connect (c,
 680                                    (unsigned int) max_parallel_bg_queries);
 681   if (NULL == dht_handle)
 682   {
 683     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 684                 _("Could not connect to DHT!\n"));
 685     GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
 686     return;
 687   }
 688
 689   if (GNUNET_OK ==
 690       GNUNET_CONFIGURATION_get_value_string (c, "gns", "DNS_ROOT",
 691                                              &dns_root_name))
 692   {
 693     if (GNUNET_OK !=
 694         GNUNET_CRYPTO_ecc_public_key_from_string (dns_root_name,
 695                                                   strlen (dns_root_name),
 696                                                   &dns_root))
 697     {
 698       GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
 699                                  "gns", "DNS_ROOT",
 700                                  _("valid public key required"));
 701       GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
 702       GNUNET_free (dns_root_name);
 703       return;
 704     }
 705     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 706                 "DNS hijacking with root `%s' enabled. Connecting to DNS service.\n",
 707                 dns_root_name);
 708     GNUNET_free (dns_root_name);
 709     if (GNUNET_SYSERR ==
 710         GNS_interceptor_init (&dns_root, c))
 711     {
 712       GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
 713       return;
 714     }
 715   }
 716   /* FIXME: install client disconnect handle to clean up pending
 717      lookups on client disconnect! */
 718   GNS_resolver_init (namestore_handle, dht_handle,
 719                      c,
 720                      max_parallel_bg_queries);
 721   GNUNET_SERVER_disconnect_notify (server,
 722                                    &notify_client_disconnect,
 723                                    NULL);
 724   /* Schedule periodic put for our records. */
 725   first_zone_iteration = GNUNET_YES;
 726   GNUNET_SERVER_add_handlers (server, handlers);
 727   statistics = GNUNET_STATISTICS_create ("gns", c);
 728   nc = GNUNET_SERVER_notification_context_create (server, 1);
 729   zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_start,
 730                                                 NULL);
 731   GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
 732                                 &shutdown_task, NULL);
 733 }
 734
 735
 736 /**
 737  * The main function for the GNS service.
 738  *
 739  * @param argc number of arguments from the command line
 740  * @param argv command line arguments
 741  * @return 0 ok, 1 on error
 742  */
 743 int
 744 main (int argc, char *const *argv)
 745 {
 746   int ret;
 747
 748   ret =
 749       (GNUNET_OK ==
 750        GNUNET_SERVICE_run (argc, argv, "gns", GNUNET_SERVICE_OPTION_NONE, &run,
 751                            NULL)) ? 0 : 1;
 752   return ret;
 753 }
 754
 755 /* end of gnunet-service-gns.c */