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