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  * Minimum relative expiration time of records seem during the current
 161  * zone iteration.
 162  */
 163 static struct GNUNET_TIME_Relative min_relative_record_time;
 164
 165 /**
 166  * Zone iteration PUT interval.
 167  */
 168 static struct GNUNET_TIME_Relative put_interval;
 169
 170 /**
 171  * Default time window for zone iteration
 172  */
 173 static struct GNUNET_TIME_Relative zone_publish_time_window_default;
 174
 175 /**
 176  * Time window for zone iteration, adjusted based on relative record
 177  * expiration times in our zone.
 178  */
 179 static struct GNUNET_TIME_Relative zone_publish_time_window;
 180
 181 /**
 182  * zone publish task
 183  */
 184 static GNUNET_SCHEDULER_TaskIdentifier zone_publish_task;
 185
 186 /**
 187  * #GNUNET_YES if zone has never been published before
 188  */
 189 static int first_zone_iteration;
 190
 191 /**
 192  * #GNUNET_YES if ipv6 is supported
 193  */
 194 static int v6_enabled;
 195
 196 /**
 197  * #GNUNET_YES if ipv4 is supported
 198  */
 199 static int v4_enabled;
 200
 201 /**
 202  * Handle to the statistics service
 203  */
 204 static struct GNUNET_STATISTICS_Handle *statistics;
 205
 206
 207 /**
 208  * Task run during shutdown.
 209  *
 210  * @param cls unused
 211  * @param tc unused
 212  */
 213 static void
 214 shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 215 {
 216   struct ClientLookupHandle *clh;
 217
 218   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 219               "Shutting down!\n");
 220   GNUNET_SERVER_notification_context_destroy (nc);
 221   while (NULL != (clh = clh_head))
 222   {
 223     GNUNET_SERVER_client_set_user_context (clh->client, NULL);
 224     GNS_resolver_lookup_cancel (clh->lookup);
 225     GNUNET_CONTAINER_DLL_remove (clh_head, clh_tail, clh);
 226     GNUNET_free (clh);
 227   }
 228
 229   GNS_interceptor_done ();
 230   GNS_resolver_done ();
 231   GNS_shorten_done ();
 232   if (NULL != statistics)
 233   {
 234     GNUNET_STATISTICS_destroy (statistics, GNUNET_NO);
 235     statistics = NULL;
 236   }
 237   if (GNUNET_SCHEDULER_NO_TASK != zone_publish_task)
 238   {
 239     GNUNET_SCHEDULER_cancel (zone_publish_task);
 240     zone_publish_task = GNUNET_SCHEDULER_NO_TASK;
 241   }
 242   if (NULL != namestore_iter)
 243   {
 244     GNUNET_NAMESTORE_zone_iteration_stop (namestore_iter);
 245     namestore_iter = NULL;
 246   }
 247   if (NULL != namestore_handle)
 248   {
 249     GNUNET_NAMESTORE_disconnect (namestore_handle);
 250     namestore_handle = NULL;
 251   }
 252   if (NULL != namecache_handle)
 253   {
 254     GNUNET_NAMECACHE_disconnect (namecache_handle);
 255     namecache_handle = NULL;
 256   }
 257   if (NULL != active_put)
 258   {
 259     GNUNET_DHT_put_cancel (active_put);
 260     active_put = NULL;
 261   }
 262   if (NULL != dht_handle)
 263   {
 264     GNUNET_DHT_disconnect (dht_handle);
 265     dht_handle = NULL;
 266   }
 267 }
 268
 269
 270 /**
 271  * Method called periodically that triggers iteration over authoritative records
 272  *
 273  * @param cls closure
 274  * @param tc task context
 275  */
 276 static void
 277 publish_zone_dht_next (void *cls,
 278                        const struct GNUNET_SCHEDULER_TaskContext *tc)
 279 {
 280   zone_publish_task = GNUNET_SCHEDULER_NO_TASK;
 281   GNUNET_NAMESTORE_zone_iterator_next (namestore_iter);
 282 }
 283
 284
 285 /**
 286  * Periodically iterate over our zone and store everything in dht
 287  *
 288  * @param cls NULL
 289  * @param tc task context
 290  */
 291 static void
 292 publish_zone_dht_start (void *cls,
 293                         const struct GNUNET_SCHEDULER_TaskContext *tc);
 294
 295
 296 /**
 297  * Continuation called from DHT once the PUT operation is done.
 298  *
 299  * @param cls closure, NULL
 300  * @param success #GNUNET_OK on success
 301  */
 302 static void
 303 dht_put_continuation (void *cls,
 304                       int success)
 305 {
 306   struct GNUNET_TIME_Relative next_put_interval;
 307
 308   active_put = NULL;
 309   num_public_records++;
 310   if ( (num_public_records > last_num_public_records) &&
 311        (GNUNET_NO == first_zone_iteration) )
 312   {
 313     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 314                 "Last record count was lower than current record count.  Reducing interval.\n");
 315     put_interval = GNUNET_TIME_relative_divide (zone_publish_time_window,
 316                                                 num_public_records);
 317     next_put_interval = GNUNET_TIME_relative_divide (put_interval,
 318                                                      LATE_ITERATION_SPEEDUP_FACTOR);
 319   }
 320   else
 321     next_put_interval = put_interval;
 322
 323   GNUNET_STATISTICS_set (statistics,
 324                          "Current zone iteration interval (ms)",
 325                          next_put_interval.rel_value_us / 1000LL,
 326                          GNUNET_NO);
 327   zone_publish_task = GNUNET_SCHEDULER_add_delayed (next_put_interval,
 328                                                     &publish_zone_dht_next,
 329                                                     NULL);
 330 }
 331
 332
 333 /**
 334  * Function used to put all records successively into the DHT.
 335  *
 336  * @param cls the closure (NULL)
 337  * @param key the private key of the authority (ours)
 338  * @param name the name of the records, NULL once the iteration is done
 339  * @param rd_count the number of records in @a rd
 340  * @param rd the record data
 341  */
 342 static void
 343 put_gns_record (void *cls,
 344                 const struct GNUNET_CRYPTO_EcdsaPrivateKey *key,
 345                 const char *name,
 346                 unsigned int rd_count,
 347                 const struct GNUNET_GNSRECORD_Data *rd)
 348 {
 349   struct GNUNET_GNSRECORD_Block *block;
 350   struct GNUNET_HashCode query;
 351   struct GNUNET_TIME_Absolute expire;
 352   struct GNUNET_TIME_Absolute now;
 353   size_t block_size;
 354   struct GNUNET_GNSRECORD_Data rd_public[rd_count];
 355   unsigned int rd_public_count;
 356   unsigned int i;
 357
 358   if (NULL == name)
 359   {
 360     /* we're done with one iteration, calculate when to do the next one */
 361     namestore_iter = NULL;
 362     last_num_public_records = num_public_records;
 363     first_zone_iteration = GNUNET_NO;
 364     if (0 == num_public_records)
 365     {
 366       /**
 367        * If no records are known (startup) or none present
 368        * we can safely set the interval to the value for a single
 369        * record
 370        */
 371       put_interval = zone_publish_time_window;
 372       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG | GNUNET_ERROR_TYPE_BULK,
 373                   "No records in namestore database.\n");
 374     }
 375     else
 376     {
 377       zone_publish_time_window
 378         = GNUNET_TIME_relative_min (GNUNET_TIME_relative_divide (min_relative_record_time,
 379                                                                  4),
 380                                     zone_publish_time_window_default);
 381       put_interval = GNUNET_TIME_relative_divide (zone_publish_time_window,
 382                                                   num_public_records);
 383     }
 384     /* reset for next iteration */
 385     min_relative_record_time = GNUNET_TIME_UNIT_FOREVER_REL;
 386     put_interval = GNUNET_TIME_relative_max (MINIMUM_ZONE_ITERATION_INTERVAL,
 387                                              put_interval);
 388
 389     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 390                 "Zone iteration finished. Adjusted zone iteration interval to %s\n",
 391                 GNUNET_STRINGS_relative_time_to_string (put_interval, GNUNET_YES));
 392     GNUNET_STATISTICS_set (statistics,
 393                            "Current zone iteration interval (in ms)",
 394                            put_interval.rel_value_us / 1000LL,
 395                            GNUNET_NO);
 396     GNUNET_STATISTICS_update (statistics,
 397                               "Number of zone iterations",
 398                               1,
 399                               GNUNET_NO);
 400     GNUNET_STATISTICS_set (statistics,
 401                            "Number of public records in DHT",
 402                            last_num_public_records,
 403                            GNUNET_NO);
 404     if (0 == num_public_records)
 405       zone_publish_task = GNUNET_SCHEDULER_add_delayed (put_interval,
 406                                                         &publish_zone_dht_start,
 407                                                         NULL);
 408     else
 409       zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_start,
 410                                                     NULL);
 411     return;
 412   }
 413
 414   /* filter out records that are not public, and convert to
 415      absolute expiration time. */
 416   rd_public_count = 0;
 417   now = GNUNET_TIME_absolute_get ();
 418   for (i=0;i<rd_count;i++)
 419     if (0 == (rd[i].flags & (GNUNET_GNSRECORD_RF_PRIVATE |
 420                              GNUNET_GNSRECORD_RF_PENDING)))
 421     {
 422       rd_public[rd_public_count] = rd[i];
 423       if (0 != (rd[i].flags & GNUNET_GNSRECORD_RF_RELATIVE_EXPIRATION))
 424       {
 425         /* GNUNET_GNSRECORD_block_create will convert to absolute time;
 426            we just need to adjust our iteration frequency */
 427         min_relative_record_time.rel_value_us =
 428           GNUNET_MIN (rd_public[rd_public_count].expiration_time,
 429                       min_relative_record_time.rel_value_us);
 430       }
 431       else if (rd_public[rd_public_count].expiration_time < now.abs_value_us)
 432       {
 433         /* record already expired, skip it */
 434         continue;
 435       }
 436       rd_public_count++;
 437     }
 438
 439   /* We got a set of records to publish */
 440   if (0 == rd_public_count)
 441   {
 442     zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_next,
 443                                                    NULL);
 444     return;
 445   }
 446   expire = GNUNET_GNSRECORD_record_get_expiration_time (rd_public_count,
 447                                                         rd_public);
 448   block = GNUNET_GNSRECORD_block_create (key,
 449                                          expire,
 450                                          name,
 451                                          rd_public,
 452                                          rd_public_count);
 453   block_size = ntohl (block->purpose.size)
 454     + sizeof (struct GNUNET_CRYPTO_EcdsaSignature)
 455     + sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey);
 456   GNUNET_GNSRECORD_query_from_private_key (key,
 457                                            name,
 458                                            &query);
 459   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 460               "Storing record in DHT with expiration `%s'\n",
 461               GNUNET_STRINGS_absolute_time_to_string (expire));
 462   active_put = GNUNET_DHT_put (dht_handle, &query,
 463                                DHT_GNS_REPLICATION_LEVEL,
 464                                GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE,
 465                                GNUNET_BLOCK_TYPE_GNS_NAMERECORD,
 466                                block_size,
 467                                block,
 468                                expire,
 469                                DHT_OPERATION_TIMEOUT,
 470                                &dht_put_continuation,
 471                                NULL);
 472   if (NULL == active_put)
 473   {
 474     GNUNET_break (0);
 475     dht_put_continuation (NULL, GNUNET_NO);
 476   }
 477   GNUNET_free (block);
 478 }
 479
 480
 481 /**
 482  * Periodically iterate over our zone and store everything in dht
 483  *
 484  * @param cls NULL
 485  * @param tc task context
 486  */
 487 static void
 488 publish_zone_dht_start (void *cls,
 489                         const struct GNUNET_SCHEDULER_TaskContext *tc)
 490 {
 491   zone_publish_task = GNUNET_SCHEDULER_NO_TASK;
 492
 493   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 494               "Starting DHT zone update!\n");
 495   /* start counting again */
 496   num_public_records = 0;
 497   namestore_iter = GNUNET_NAMESTORE_zone_iteration_start (namestore_handle,
 498                                                           NULL, /* All zones */
 499                                                           &put_gns_record,
 500                                                           NULL);
 501 }
 502
 503
 504 /* END DHT ZONE PROPAGATION */
 505
 506
 507 /**
 508  * Reply to client with the result from our lookup.
 509  *
 510  * @param cls the closure (our client lookup handle)
 511  * @param rd_count the number of records in @a rd
 512  * @param rd the record data
 513  */
 514 static void
 515 send_lookup_response (void* cls,
 516                       uint32_t rd_count,
 517                       const struct GNUNET_GNSRECORD_Data *rd)
 518 {
 519   struct ClientLookupHandle *clh = cls;
 520   struct GNUNET_GNS_ClientLookupResultMessage *rmsg;
 521   size_t len;
 522
 523   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 524               "Sending `%s' message with %d results\n",
 525               "LOOKUP_RESULT",
 526               rd_count);
 527
 528   len = GNUNET_GNSRECORD_records_get_size (rd_count, rd);
 529   rmsg = GNUNET_malloc (len + sizeof (struct GNUNET_GNS_ClientLookupResultMessage));
 530   rmsg->header.type = htons (GNUNET_MESSAGE_TYPE_GNS_LOOKUP_RESULT);
 531   rmsg->header.size = htons (len + sizeof(struct GNUNET_GNS_ClientLookupResultMessage));
 532   rmsg->id = clh->request_id;
 533   rmsg->rd_count = htonl (rd_count);
 534   GNUNET_GNSRECORD_records_serialize (rd_count, rd, len,
 535                                       (char*) &rmsg[1]);
 536   GNUNET_SERVER_notification_context_unicast (nc,
 537                                               clh->client,
 538                                               &rmsg->header,
 539                                               GNUNET_NO);
 540   GNUNET_free (rmsg);
 541   GNUNET_CONTAINER_DLL_remove (clh_head, clh_tail, clh);
 542   GNUNET_SERVER_client_set_user_context (clh->client, NULL);
 543   GNUNET_free (clh);
 544   GNUNET_STATISTICS_update (statistics,
 545                             "Completed lookups", 1,
 546                             GNUNET_NO);
 547   GNUNET_STATISTICS_update (statistics,
 548                             "Records resolved",
 549                             rd_count,
 550                             GNUNET_NO);
 551 }
 552
 553
 554 /**
 555  * Handle lookup requests from client
 556  *
 557  * @param cls the closure
 558  * @param client the client
 559  * @param message the message
 560  */
 561 static void
 562 handle_lookup (void *cls,
 563                struct GNUNET_SERVER_Client *client,
 564                const struct GNUNET_MessageHeader *message)
 565 {
 566   char name[GNUNET_DNSPARSER_MAX_NAME_LENGTH + 1];
 567   struct ClientLookupHandle *clh;
 568   char *nameptr = name;
 569   const char *utf_in;
 570   const struct GNUNET_CRYPTO_EcdsaPrivateKey *key;
 571   uint16_t msg_size;
 572   const struct GNUNET_GNS_ClientLookupMessage *sh_msg;
 573
 574   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 575               "Received `%s' message\n",
 576               "LOOKUP");
 577   msg_size = ntohs (message->size);
 578   if (msg_size < sizeof (struct GNUNET_GNS_ClientLookupMessage))
 579   {
 580     GNUNET_break (0);
 581     GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
 582     return;
 583   }
 584   sh_msg = (const struct GNUNET_GNS_ClientLookupMessage *) message;
 585   GNUNET_SERVER_notification_context_add (nc, client);
 586   if (GNUNET_YES == ntohs (sh_msg->have_key))
 587     key = &sh_msg->shorten_key;
 588   else
 589     key = NULL;
 590   utf_in = (const char *) &sh_msg[1];
 591   if ( ('\0' != utf_in[msg_size - sizeof (struct GNUNET_GNS_ClientLookupMessage) - 1]) ||
 592        (strlen (utf_in) > GNUNET_DNSPARSER_MAX_NAME_LENGTH) )
 593   {
 594     GNUNET_break (0);
 595     GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
 596     return;
 597   }
 598   GNUNET_STRINGS_utf8_tolower (utf_in, &nameptr);
 599   GNUNET_SERVER_receive_done (client, GNUNET_OK);
 600
 601   clh = GNUNET_new (struct ClientLookupHandle);
 602   GNUNET_SERVER_client_set_user_context (client, clh);
 603   GNUNET_CONTAINER_DLL_insert (clh_head, clh_tail, clh);
 604   clh->client = client;
 605   clh->request_id = sh_msg->id;
 606   if ( (GNUNET_DNSPARSER_TYPE_A == ntohl (sh_msg->type)) &&
 607        (GNUNET_OK != v4_enabled) )
 608   {
 609     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 610                 "LOOKUP: Query for A record but AF_INET not supported!");
 611     send_lookup_response (clh, 0, NULL);
 612     return;
 613   }
 614   if ( (GNUNET_DNSPARSER_TYPE_AAAA == ntohl (sh_msg->type)) &&
 615        (GNUNET_OK != v6_enabled) )
 616   {
 617     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 618                 "LOOKUP: Query for AAAA record but AF_INET6 not supported!");
 619     send_lookup_response (clh, 0, NULL);
 620     return;
 621   }
 622   clh->lookup = GNS_resolver_lookup (&sh_msg->zone,
 623                                      ntohl (sh_msg->type),
 624                                      name,
 625                                      key,
 626                                      ntohl (sh_msg->only_cached),
 627                                      &send_lookup_response, clh);
 628   GNUNET_STATISTICS_update (statistics,
 629                             "Lookup attempts",
 630                             1, GNUNET_NO);
 631 }
 632
 633
 634 /**
 635  * One of our clients disconnected, clean up after it.
 636  *
 637  * @param cls NULL
 638  * @param client the client that disconnected
 639  */
 640 static void
 641 notify_client_disconnect (void *cls,
 642                           struct GNUNET_SERVER_Client *client)
 643 {
 644   struct ClientLookupHandle *clh;
 645
 646   if (NULL == client)
 647     return;
 648   clh = GNUNET_SERVER_client_get_user_context (client, struct ClientLookupHandle);
 649   if (NULL == clh)
 650     return;
 651   GNS_resolver_lookup_cancel (clh->lookup);
 652   GNUNET_CONTAINER_DLL_remove (clh_head, clh_tail, clh);
 653   GNUNET_free (clh);
 654 }
 655
 656
 657 /**
 658  * Process GNS requests.
 659  *
 660  * @param cls closure
 661  * @param server the initialized server
 662  * @param c configuration to use
 663  */
 664 static void
 665 run (void *cls, struct GNUNET_SERVER_Handle *server,
 666      const struct GNUNET_CONFIGURATION_Handle *c)
 667 {
 668   static const struct GNUNET_SERVER_MessageHandler handlers[] = {
 669     { &handle_lookup, NULL, GNUNET_MESSAGE_TYPE_GNS_LOOKUP, 0},
 670     {NULL, NULL, 0, 0}
 671   };
 672   struct GNUNET_CRYPTO_EcdsaPublicKey dns_root;
 673   unsigned long long max_parallel_bg_queries = 0;
 674   char *dns_root_name;
 675
 676   v6_enabled = GNUNET_NETWORK_test_pf (PF_INET6);
 677   v4_enabled = GNUNET_NETWORK_test_pf (PF_INET);
 678   min_relative_record_time = GNUNET_TIME_UNIT_FOREVER_REL;
 679   namestore_handle = GNUNET_NAMESTORE_connect (c);
 680   if (NULL == namestore_handle)
 681   {
 682     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 683                 _("Failed to connect to the namestore!\n"));
 684     GNUNET_SCHEDULER_shutdown ();
 685     return;
 686   }
 687   namecache_handle = GNUNET_NAMECACHE_connect (c);
 688   if (NULL == namecache_handle)
 689   {
 690     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 691                 _("Failed to connect to the namecache!\n"));
 692     GNUNET_SCHEDULER_shutdown ();
 693     return;
 694   }
 695
 696   put_interval = INITIAL_PUT_INTERVAL;
 697   zone_publish_time_window_default = DEFAULT_ZONE_PUBLISH_TIME_WINDOW;
 698   if (GNUNET_OK ==
 699       GNUNET_CONFIGURATION_get_value_time (c, "gns",
 700                                            "ZONE_PUBLISH_TIME_WINDOW",
 701                                            &zone_publish_time_window_default))
 702   {
 703     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 704                 "Time window for zone iteration: %s\n",
 705                 GNUNET_STRINGS_relative_time_to_string (zone_publish_time_window,
 706                                                         GNUNET_YES));
 707   }
 708   zone_publish_time_window = zone_publish_time_window_default;
 709   if (GNUNET_OK ==
 710       GNUNET_CONFIGURATION_get_value_number (c, "gns",
 711                                             "MAX_PARALLEL_BACKGROUND_QUERIES",
 712                                             &max_parallel_bg_queries))
 713   {
 714     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 715                 "Number of allowed parallel background queries: %llu\n",
 716                 max_parallel_bg_queries);
 717   }
 718
 719   dht_handle = GNUNET_DHT_connect (c,
 720                                    (unsigned int) max_parallel_bg_queries);
 721   if (NULL == dht_handle)
 722   {
 723     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 724                 _("Could not connect to DHT!\n"));
 725     GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
 726     return;
 727   }
 728
 729   if (GNUNET_OK ==
 730       GNUNET_CONFIGURATION_get_value_string (c, "gns", "DNS_ROOT",
 731                                              &dns_root_name))
 732   {
 733     if (GNUNET_OK !=
 734         GNUNET_CRYPTO_ecdsa_public_key_from_string (dns_root_name,
 735                                                   strlen (dns_root_name),
 736                                                   &dns_root))
 737     {
 738       GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
 739                                  "gns", "DNS_ROOT",
 740                                  _("valid public key required"));
 741       GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
 742       GNUNET_free (dns_root_name);
 743       return;
 744     }
 745     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 746                 "DNS hijacking with root `%s' enabled. Connecting to DNS service.\n",
 747                 dns_root_name);
 748     GNUNET_free (dns_root_name);
 749     if (GNUNET_SYSERR ==
 750         GNS_interceptor_init (&dns_root, c))
 751     {
 752       GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
 753       return;
 754     }
 755   }
 756   GNS_resolver_init (namestore_handle,
 757                      namecache_handle,
 758                      dht_handle,
 759                      c,
 760                      max_parallel_bg_queries);
 761   GNS_shorten_init (namestore_handle,
 762                     namecache_handle,
 763                     dht_handle);
 764   GNUNET_SERVER_disconnect_notify (server,
 765                                    &notify_client_disconnect,
 766                                    NULL);
 767   /* Schedule periodic put for our records. */
 768   first_zone_iteration = GNUNET_YES;
 769   GNUNET_SERVER_add_handlers (server, handlers);
 770   statistics = GNUNET_STATISTICS_create ("gns", c);
 771   nc = GNUNET_SERVER_notification_context_create (server, 1);
 772   zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_start,
 773                                                 NULL);
 774   GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
 775                                 &shutdown_task, NULL);
 776 }
 777
 778
 779 /**
 780  * The main function for the GNS service.
 781  *
 782  * @param argc number of arguments from the command line
 783  * @param argv command line arguments
 784  * @return 0 ok, 1 on error
 785  */
 786 int
 787 main (int argc, char *const *argv)
 788 {
 789   int ret;
 790
 791   ret =
 792       (GNUNET_OK ==
 793        GNUNET_SERVICE_run (argc, argv, "gns", GNUNET_SERVICE_OPTION_NONE, &run,
 794                            NULL)) ? 0 : 1;
 795   return ret;
 796 }
 797
 798 /* end of gnunet-service-gns.c */