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