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 GNU Name System (main service)
  23  * @author Martin Schanzenbach
  24  * @author Christian Grothoff
  25  */
  26 #include "platform.h"
  27 #include "gnunet_util_lib.h"
  28 #include "gnunet_dns_service.h"
  29 #include "gnunet_dnsparser_lib.h"
  30 #include "gnunet_dht_service.h"
  31 #include "gnunet_namecache_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 "gnunet-service-gns_resolver.h"
  37 #include "gnunet-service-gns_shorten.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  * Our handle to the namecache service
 126  */
 127 static struct GNUNET_NAMECACHE_Handle *namecache_handle;
 128
 129 /**
 130  * Handle to iterate over our authoritative zone in namestore
 131  */
 132 static struct GNUNET_NAMESTORE_ZoneIterator *namestore_iter;
 133
 134 /**
 135  * Our notification context.
 136  */
 137 static struct GNUNET_SERVER_NotificationContext *nc;
 138
 139 /**
 140  * Head of the DLL.
 141  */
 142 static struct ClientLookupHandle *clh_head;
 143
 144 /**
 145  * Tail of the DLL.
 146  */
 147 static struct ClientLookupHandle *clh_tail;
 148
 149 /**
 150  * Useful for zone update for DHT put
 151  */
 152 static unsigned long long num_public_records;
 153
 154 /**
 155  * Last seen record count
 156  */
 157 static unsigned long long last_num_public_records;
 158
 159 /**
 160  * Zone iteration PUT interval.
 161  */
 162 static struct GNUNET_TIME_Relative put_interval;
 163
 164 /**
 165  * Time window for zone iteration
 166  */
 167 static struct GNUNET_TIME_Relative zone_publish_time_window;
 168
 169 /**
 170  * zone publish task
 171  */
 172 static GNUNET_SCHEDULER_TaskIdentifier zone_publish_task;
 173
 174 /**
 175  * #GNUNET_YES if zone has never been published before
 176  */
 177 static int first_zone_iteration;
 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     GNUNET_SERVER_client_set_user_context (clh->client, NULL);
 212     GNS_resolver_lookup_cancel (clh->lookup);
 213     GNUNET_CONTAINER_DLL_remove (clh_head, clh_tail, clh);
 214     GNUNET_free (clh);
 215   }
 216
 217   GNS_interceptor_done ();
 218   GNS_resolver_done ();
 219   GNS_shorten_done ();
 220   if (NULL != statistics)
 221   {
 222     GNUNET_STATISTICS_destroy (statistics, GNUNET_NO);
 223     statistics = NULL;
 224   }
 225   if (GNUNET_SCHEDULER_NO_TASK != zone_publish_task)
 226   {
 227     GNUNET_SCHEDULER_cancel (zone_publish_task);
 228     zone_publish_task = GNUNET_SCHEDULER_NO_TASK;
 229   }
 230   if (NULL != namestore_iter)
 231   {
 232     GNUNET_NAMESTORE_zone_iteration_stop (namestore_iter);
 233     namestore_iter = NULL;
 234   }
 235   if (NULL != namestore_handle)
 236   {
 237     GNUNET_NAMESTORE_disconnect (namestore_handle);
 238     namestore_handle = NULL;
 239   }
 240   if (NULL != namecache_handle)
 241   {
 242     GNUNET_NAMECACHE_disconnect (namecache_handle);
 243     namecache_handle = NULL;
 244   }
 245   if (NULL != active_put)
 246   {
 247     GNUNET_DHT_put_cancel (active_put);
 248     active_put = NULL;
 249   }
 250   if (NULL != dht_handle)
 251   {
 252     GNUNET_DHT_disconnect (dht_handle);
 253     dht_handle = NULL;
 254   }
 255 }
 256
 257
 258 /**
 259  * Method called periodically that triggers iteration over authoritative records
 260  *
 261  * @param cls closure
 262  * @param tc task context
 263  */
 264 static void
 265 publish_zone_dht_next (void *cls,
 266                        const struct GNUNET_SCHEDULER_TaskContext *tc)
 267 {
 268   zone_publish_task = GNUNET_SCHEDULER_NO_TASK;
 269   GNUNET_NAMESTORE_zone_iterator_next (namestore_iter);
 270 }
 271
 272
 273 /**
 274  * Periodically iterate over our zone and store everything in dht
 275  *
 276  * @param cls NULL
 277  * @param tc task context
 278  */
 279 static void
 280 publish_zone_dht_start (void *cls,
 281                         const struct GNUNET_SCHEDULER_TaskContext *tc);
 282
 283
 284 /**
 285  * Continuation called from DHT once the PUT operation is done.
 286  *
 287  * @param cls closure, NULL
 288  * @param success #GNUNET_OK on success
 289  */
 290 static void
 291 dht_put_continuation (void *cls,
 292                       int success)
 293 {
 294   struct GNUNET_TIME_Relative next_put_interval;
 295
 296   active_put = NULL;
 297   num_public_records++;
 298   if ( (num_public_records > last_num_public_records) &&
 299        (GNUNET_NO == first_zone_iteration) )
 300   {
 301     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 302                 "Last record count was lower than current record count.  Reducing interval.\n");
 303     put_interval = GNUNET_TIME_relative_divide (zone_publish_time_window,
 304                                                 num_public_records);
 305     next_put_interval = GNUNET_TIME_relative_divide (put_interval,
 306                                                      LATE_ITERATION_SPEEDUP_FACTOR);
 307   }
 308   else
 309     next_put_interval = put_interval;
 310
 311   GNUNET_STATISTICS_set (statistics,
 312                          "Current zone iteration interval (ms)",
 313                          next_put_interval.rel_value_us / 1000LL,
 314                          GNUNET_NO);
 315   zone_publish_task = GNUNET_SCHEDULER_add_delayed (next_put_interval,
 316                                                     &publish_zone_dht_next,
 317                                                     NULL);
 318 }
 319
 320
 321 /**
 322  * Function used to put all records successively into the DHT.
 323  *
 324  * @param cls the closure (NULL)
 325  * @param key the private key of the authority (ours)
 326  * @param name the name of the records, NULL once the iteration is done
 327  * @param rd_count the number of records in @a rd
 328  * @param rd the record data
 329  */
 330 static void
 331 put_gns_record (void *cls,
 332                 const struct GNUNET_CRYPTO_EcdsaPrivateKey *key,
 333                 const char *name,
 334                 unsigned int rd_count,
 335                 const struct GNUNET_GNSRECORD_Data *rd)
 336 {
 337   struct GNUNET_GNSRECORD_Block *block;
 338   struct GNUNET_HashCode query;
 339   struct GNUNET_TIME_Absolute expire;
 340   struct GNUNET_TIME_Absolute now;
 341   size_t block_size;
 342   struct GNUNET_GNSRECORD_Data rd_public[rd_count];
 343   unsigned int rd_public_count;
 344   unsigned int i;
 345
 346   if (NULL == name)
 347   {
 348     /* we're done with one iteration, calculate when to do the next one */
 349     namestore_iter = NULL;
 350     last_num_public_records = num_public_records;
 351     first_zone_iteration = GNUNET_NO;
 352     if (0 == num_public_records)
 353     {
 354       /**
 355        * If no records are known (startup) or none present
 356        * we can safely set the interval to the value for a single
 357        * record
 358        */
 359       put_interval = zone_publish_time_window;
 360       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG | GNUNET_ERROR_TYPE_BULK,
 361                   "No records in namestore database.\n");
 362     }
 363     else
 364     {
 365       put_interval = GNUNET_TIME_relative_divide (zone_publish_time_window,
 366                                                   num_public_records);
 367     }
 368     put_interval = GNUNET_TIME_relative_max (MINIMUM_ZONE_ITERATION_INTERVAL,
 369                                              put_interval);
 370
 371     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 372                 "Zone iteration finished. Adjusted zone iteration interval to %s\n",
 373                 GNUNET_STRINGS_relative_time_to_string (put_interval, GNUNET_YES));
 374     GNUNET_STATISTICS_set (statistics,
 375                            "Current zone iteration interval (in ms)",
 376                            put_interval.rel_value_us / 1000LL,
 377                            GNUNET_NO);
 378     GNUNET_STATISTICS_update (statistics,
 379                               "Number of zone iterations",
 380                               1,
 381                               GNUNET_NO);
 382     GNUNET_STATISTICS_set (statistics,
 383                            "Number of public records in DHT",
 384                            last_num_public_records,
 385                            GNUNET_NO);
 386     if (0 == num_public_records)
 387       zone_publish_task = GNUNET_SCHEDULER_add_delayed (put_interval,
 388                                                         &publish_zone_dht_start,
 389                                                         NULL);
 390     else
 391       zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_start,
 392                                                     NULL);
 393     return;
 394   }
 395
 396   /* filter out records that are not public, and convert to
 397      absolute expiration time. */
 398   rd_public_count = 0;
 399   now = GNUNET_TIME_absolute_get ();
 400   for (i=0;i<rd_count;i++)
 401     if (0 == (rd[i].flags & (GNUNET_GNSRECORD_RF_PRIVATE |
 402                              GNUNET_GNSRECORD_RF_PENDING)))
 403     {
 404       rd_public[rd_public_count] = rd[i];
 405       if (0 != (rd[i].flags & GNUNET_GNSRECORD_RF_RELATIVE_EXPIRATION))
 406       {
 407         rd_public[rd_public_count].flags &= ~GNUNET_GNSRECORD_RF_RELATIVE_EXPIRATION;
 408         rd_public[rd_public_count].expiration_time += now.abs_value_us;
 409       }
 410       rd_public_count++;
 411     }
 412
 413   /* We got a set of records to publish */
 414   if (0 == rd_public_count)
 415   {
 416     zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_next,
 417                                                    NULL);
 418     return;
 419   }
 420   expire = GNUNET_GNSRECORD_record_get_expiration_time (rd_public_count,
 421                                                         rd_public);
 422   block = GNUNET_GNSRECORD_block_create (key,
 423                                          expire,
 424                                          name,
 425                                          rd_public,
 426                                          rd_public_count);
 427   block_size = ntohl (block->purpose.size)
 428     + sizeof (struct GNUNET_CRYPTO_EcdsaSignature)
 429     + sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey);
 430   GNUNET_GNSRECORD_query_from_private_key (key,
 431                                            name,
 432                                            &query);
 433
 434   active_put = GNUNET_DHT_put (dht_handle, &query,
 435                                DHT_GNS_REPLICATION_LEVEL,
 436                                GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE,
 437                                GNUNET_BLOCK_TYPE_GNS_NAMERECORD,
 438                                block_size,
 439                                block,
 440                                expire,
 441                                DHT_OPERATION_TIMEOUT,
 442                                &dht_put_continuation,
 443                                NULL);
 444   if (NULL == active_put)
 445   {
 446     GNUNET_break (0);
 447     dht_put_continuation (NULL, GNUNET_NO);
 448   }
 449   GNUNET_free (block);
 450 }
 451
 452
 453 /**
 454  * Periodically iterate over our zone and store everything in dht
 455  *
 456  * @param cls NULL
 457  * @param tc task context
 458  */
 459 static void
 460 publish_zone_dht_start (void *cls,
 461                         const struct GNUNET_SCHEDULER_TaskContext *tc)
 462 {
 463   zone_publish_task = GNUNET_SCHEDULER_NO_TASK;
 464
 465   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 466               "Scheduling DHT zone update!\n");
 467   /* start counting again */
 468   num_public_records = 0;
 469   namestore_iter = GNUNET_NAMESTORE_zone_iteration_start (namestore_handle,
 470                                                           NULL, /* All zones */
 471                                                           &put_gns_record,
 472                                                           NULL);
 473 }
 474
 475
 476 /* END DHT ZONE PROPAGATION */
 477
 478
 479 /**
 480  * Reply to client with the result from our lookup.
 481  *
 482  * @param cls the closure (our client lookup handle)
 483  * @param rd_count the number of records in @a rd
 484  * @param rd the record data
 485  */
 486 static void
 487 send_lookup_response (void* cls,
 488                       uint32_t rd_count,
 489                       const struct GNUNET_GNSRECORD_Data *rd)
 490 {
 491   struct ClientLookupHandle *clh = cls;
 492   struct GNUNET_GNS_ClientLookupResultMessage *rmsg;
 493   size_t len;
 494
 495   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 496               "Sending `%s' message with %d results\n",
 497               "LOOKUP_RESULT",
 498               rd_count);
 499
 500   len = GNUNET_GNSRECORD_records_get_size (rd_count, rd);
 501   rmsg = GNUNET_malloc (len + sizeof (struct GNUNET_GNS_ClientLookupResultMessage));
 502   rmsg->header.type = htons (GNUNET_MESSAGE_TYPE_GNS_LOOKUP_RESULT);
 503   rmsg->header.size = htons (len + sizeof(struct GNUNET_GNS_ClientLookupResultMessage));
 504   rmsg->id = clh->request_id;
 505   rmsg->rd_count = htonl (rd_count);
 506   GNUNET_GNSRECORD_records_serialize (rd_count, rd, len,
 507                                       (char*) &rmsg[1]);
 508   GNUNET_SERVER_notification_context_unicast (nc,
 509                                               clh->client,
 510                                               &rmsg->header,
 511                                               GNUNET_NO);
 512   GNUNET_free (rmsg);
 513   GNUNET_CONTAINER_DLL_remove (clh_head, clh_tail, clh);
 514   GNUNET_SERVER_client_set_user_context (clh->client, NULL);
 515   GNUNET_free (clh);
 516   GNUNET_STATISTICS_update (statistics,
 517                             "Completed lookups", 1,
 518                             GNUNET_NO);
 519   GNUNET_STATISTICS_update (statistics,
 520                             "Records resolved",
 521                             rd_count,
 522                             GNUNET_NO);
 523 }
 524
 525
 526 /**
 527  * Handle lookup requests from client
 528  *
 529  * @param cls the closure
 530  * @param client the client
 531  * @param message the message
 532  */
 533 static void
 534 handle_lookup (void *cls,
 535                struct GNUNET_SERVER_Client *client,
 536                const struct GNUNET_MessageHeader *message)
 537 {
 538   char name[GNUNET_DNSPARSER_MAX_NAME_LENGTH + 1];
 539   struct ClientLookupHandle *clh;
 540   char *nameptr = name;
 541   const char *utf_in;
 542   const struct GNUNET_CRYPTO_EcdsaPrivateKey *key;
 543   uint16_t msg_size;
 544   const struct GNUNET_GNS_ClientLookupMessage *sh_msg;
 545
 546   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 547               "Received `%s' message\n",
 548               "LOOKUP");
 549   msg_size = ntohs (message->size);
 550   if (msg_size < sizeof (struct GNUNET_GNS_ClientLookupMessage))
 551   {
 552     GNUNET_break (0);
 553     GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
 554     return;
 555   }
 556   sh_msg = (const struct GNUNET_GNS_ClientLookupMessage *) message;
 557   GNUNET_SERVER_notification_context_add (nc, client);
 558   if (GNUNET_YES == ntohs (sh_msg->have_key))
 559     key = &sh_msg->shorten_key;
 560   else
 561     key = NULL;
 562   utf_in = (const char *) &sh_msg[1];
 563   if ( ('\0' != utf_in[msg_size - sizeof (struct GNUNET_GNS_ClientLookupMessage) - 1]) ||
 564        (strlen (utf_in) > GNUNET_DNSPARSER_MAX_NAME_LENGTH) )
 565   {
 566     GNUNET_break (0);
 567     GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
 568     return;
 569   }
 570   GNUNET_STRINGS_utf8_tolower (utf_in, &nameptr);
 571   GNUNET_SERVER_receive_done (client, GNUNET_OK);
 572
 573   clh = GNUNET_new (struct ClientLookupHandle);
 574   GNUNET_SERVER_client_set_user_context (client, clh);
 575   GNUNET_CONTAINER_DLL_insert (clh_head, clh_tail, clh);
 576   clh->client = client;
 577   clh->request_id = sh_msg->id;
 578   if ( (GNUNET_DNSPARSER_TYPE_A == ntohl (sh_msg->type)) &&
 579        (GNUNET_OK != v4_enabled) )
 580   {
 581     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 582                 "LOOKUP: Query for A record but AF_INET not supported!");
 583     send_lookup_response (clh, 0, NULL);
 584     return;
 585   }
 586   if ( (GNUNET_DNSPARSER_TYPE_AAAA == ntohl (sh_msg->type)) &&
 587        (GNUNET_OK != v6_enabled) )
 588   {
 589     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 590                 "LOOKUP: Query for AAAA record but AF_INET6 not supported!");
 591     send_lookup_response (clh, 0, NULL);
 592     return;
 593   }
 594   clh->lookup = GNS_resolver_lookup (&sh_msg->zone,
 595                                      ntohl (sh_msg->type),
 596                                      name,
 597                                      key,
 598                                      ntohl (sh_msg->only_cached),
 599                                      &send_lookup_response, clh);
 600   GNUNET_STATISTICS_update (statistics,
 601                             "Lookup attempts",
 602                             1, GNUNET_NO);
 603 }
 604
 605
 606 /**
 607  * One of our clients disconnected, clean up after it.
 608  *
 609  * @param cls NULL
 610  * @param client the client that disconnected
 611  */
 612 static void
 613 notify_client_disconnect (void *cls,
 614                           struct GNUNET_SERVER_Client *client)
 615 {
 616   struct ClientLookupHandle *clh;
 617
 618   if (NULL == client)
 619     return;
 620   clh = GNUNET_SERVER_client_get_user_context (client, struct ClientLookupHandle);
 621   if (NULL == clh)
 622     return;
 623   GNS_resolver_lookup_cancel (clh->lookup);
 624   GNUNET_CONTAINER_DLL_remove (clh_head, clh_tail, clh);
 625   GNUNET_free (clh);
 626 }
 627
 628
 629 /**
 630  * Process GNS requests.
 631  *
 632  * @param cls closure
 633  * @param server the initialized server
 634  * @param c configuration to use
 635  */
 636 static void
 637 run (void *cls, struct GNUNET_SERVER_Handle *server,
 638      const struct GNUNET_CONFIGURATION_Handle *c)
 639 {
 640   static const struct GNUNET_SERVER_MessageHandler handlers[] = {
 641     { &handle_lookup, NULL, GNUNET_MESSAGE_TYPE_GNS_LOOKUP, 0},
 642     {NULL, NULL, 0, 0}
 643   };
 644   struct GNUNET_CRYPTO_EcdsaPublicKey dns_root;
 645   unsigned long long max_parallel_bg_queries = 0;
 646   char *dns_root_name;
 647
 648   v6_enabled = GNUNET_NETWORK_test_pf (PF_INET6);
 649   v4_enabled = GNUNET_NETWORK_test_pf (PF_INET);
 650
 651   namestore_handle = GNUNET_NAMESTORE_connect (c);
 652   if (NULL == namestore_handle)
 653   {
 654     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 655                 _("Failed to connect to the namestore!\n"));
 656     GNUNET_SCHEDULER_shutdown ();
 657     return;
 658   }
 659   namecache_handle = GNUNET_NAMECACHE_connect (c);
 660   if (NULL == namecache_handle)
 661   {
 662     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 663                 _("Failed to connect to the namecache!\n"));
 664     GNUNET_SCHEDULER_shutdown ();
 665     return;
 666   }
 667
 668   put_interval = INITIAL_PUT_INTERVAL;
 669   zone_publish_time_window = DEFAULT_ZONE_PUBLISH_TIME_WINDOW;
 670
 671   if (GNUNET_OK ==
 672       GNUNET_CONFIGURATION_get_value_time (c, "gns",
 673                                            "ZONE_PUBLISH_TIME_WINDOW",
 674                                            &zone_publish_time_window))
 675   {
 676     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 677                 "Time window for zone iteration: %s\n",
 678                 GNUNET_STRINGS_relative_time_to_string (zone_publish_time_window, GNUNET_YES));
 679   }
 680   if (GNUNET_OK ==
 681       GNUNET_CONFIGURATION_get_value_number (c, "gns",
 682                                             "MAX_PARALLEL_BACKGROUND_QUERIES",
 683                                             &max_parallel_bg_queries))
 684   {
 685     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 686                 "Number of allowed parallel background queries: %llu\n",
 687                 max_parallel_bg_queries);
 688   }
 689
 690   dht_handle = GNUNET_DHT_connect (c,
 691                                    (unsigned int) max_parallel_bg_queries);
 692   if (NULL == dht_handle)
 693   {
 694     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 695                 _("Could not connect to DHT!\n"));
 696     GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
 697     return;
 698   }
 699
 700   if (GNUNET_OK ==
 701       GNUNET_CONFIGURATION_get_value_string (c, "gns", "DNS_ROOT",
 702                                              &dns_root_name))
 703   {
 704     if (GNUNET_OK !=
 705         GNUNET_CRYPTO_ecdsa_public_key_from_string (dns_root_name,
 706                                                   strlen (dns_root_name),
 707                                                   &dns_root))
 708     {
 709       GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
 710                                  "gns", "DNS_ROOT",
 711                                  _("valid public key required"));
 712       GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
 713       GNUNET_free (dns_root_name);
 714       return;
 715     }
 716     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 717                 "DNS hijacking with root `%s' enabled. Connecting to DNS service.\n",
 718                 dns_root_name);
 719     GNUNET_free (dns_root_name);
 720     if (GNUNET_SYSERR ==
 721         GNS_interceptor_init (&dns_root, c))
 722     {
 723       GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
 724       return;
 725     }
 726   }
 727   GNS_resolver_init (namestore_handle,
 728                      namecache_handle,
 729                      dht_handle,
 730                      c,
 731                      max_parallel_bg_queries);
 732   GNS_shorten_init (namestore_handle,
 733                     namecache_handle,
 734                     dht_handle);
 735   GNUNET_SERVER_disconnect_notify (server,
 736                                    &notify_client_disconnect,
 737                                    NULL);
 738   /* Schedule periodic put for our records. */
 739   first_zone_iteration = GNUNET_YES;
 740   GNUNET_SERVER_add_handlers (server, handlers);
 741   statistics = GNUNET_STATISTICS_create ("gns", c);
 742   nc = GNUNET_SERVER_notification_context_create (server, 1);
 743   zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_start,
 744                                                 NULL);
 745   GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
 746                                 &shutdown_task, NULL);
 747 }
 748
 749
 750 /**
 751  * The main function for the GNS service.
 752  *
 753  * @param argc number of arguments from the command line
 754  * @param argv command line arguments
 755  * @return 0 ok, 1 on error
 756  */
 757 int
 758 main (int argc, char *const *argv)
 759 {
 760   int ret;
 761
 762   ret =
 763       (GNUNET_OK ==
 764        GNUNET_SERVICE_run (argc, argv, "gns", GNUNET_SERVICE_OPTION_NONE, &run,
 765                            NULL)) ? 0 : 1;
 766   return ret;
 767 }
 768
 769 /* end of gnunet-service-gns.c */