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  * Handle for DHT PUT activity triggered from the namestore monitor.
 111  */
 112 struct MonitorActivity
 113 {
 114   /**
 115    * Kept in a DLL.
 116    */
 117   struct MonitorActivity *next;
 118
 119   /**
 120    * Kept in a DLL.
 121    */
 122   struct MonitorActivity *prev;
 123
 124   /**
 125    * Handle for the DHT PUT operation.
 126    */
 127   struct GNUNET_DHT_PutHandle *ph;
 128 };
 129
 130
 131 /**
 132  * Our handle to the DHT
 133  */
 134 static struct GNUNET_DHT_Handle *dht_handle;
 135
 136 /**
 137  * Active DHT put operation (or NULL)
 138  */
 139 static struct GNUNET_DHT_PutHandle *active_put;
 140
 141 /**
 142  * Our handle to the namestore service
 143  */
 144 static struct GNUNET_NAMESTORE_Handle *namestore_handle;
 145
 146 /**
 147  * Our handle to the namecache service
 148  */
 149 static struct GNUNET_NAMECACHE_Handle *namecache_handle;
 150
 151 /**
 152  * Handle to iterate over our authoritative zone in namestore
 153  */
 154 static struct GNUNET_NAMESTORE_ZoneIterator *namestore_iter;
 155
 156 /**
 157  * Handle to monitor namestore changes to instant propagation.
 158  */
 159 static struct GNUNET_NAMESTORE_ZoneMonitor *zmon;
 160
 161 /**
 162  * Our notification context.
 163  */
 164 static struct GNUNET_SERVER_NotificationContext *nc;
 165
 166 /**
 167  * Head of the DLL.
 168  */
 169 static struct ClientLookupHandle *clh_head;
 170
 171 /**
 172  * Tail of the DLL.
 173  */
 174 static struct ClientLookupHandle *clh_tail;
 175
 176 /**
 177  * Head of monitor activities; kept in a DLL.
 178  */
 179 static struct MonitorActivity *ma_head;
 180
 181 /**
 182  * Tail of monitor activities; kept in a DLL.
 183  */
 184 static struct MonitorActivity *ma_tail;
 185
 186 /**
 187  * Useful for zone update for DHT put
 188  */
 189 static unsigned long long num_public_records;
 190
 191 /**
 192  * Last seen record count
 193  */
 194 static unsigned long long last_num_public_records;
 195
 196 /**
 197  * Minimum relative expiration time of records seem during the current
 198  * zone iteration.
 199  */
 200 static struct GNUNET_TIME_Relative min_relative_record_time;
 201
 202 /**
 203  * Zone iteration PUT interval.
 204  */
 205 static struct GNUNET_TIME_Relative put_interval;
 206
 207 /**
 208  * Default time window for zone iteration
 209  */
 210 static struct GNUNET_TIME_Relative zone_publish_time_window_default;
 211
 212 /**
 213  * Time window for zone iteration, adjusted based on relative record
 214  * expiration times in our zone.
 215  */
 216 static struct GNUNET_TIME_Relative zone_publish_time_window;
 217
 218 /**
 219  * zone publish task
 220  */
 221 static GNUNET_SCHEDULER_TaskIdentifier zone_publish_task;
 222
 223 /**
 224  * #GNUNET_YES if zone has never been published before
 225  */
 226 static int first_zone_iteration;
 227
 228 /**
 229  * #GNUNET_YES if ipv6 is supported
 230  */
 231 static int v6_enabled;
 232
 233 /**
 234  * #GNUNET_YES if ipv4 is supported
 235  */
 236 static int v4_enabled;
 237
 238 /**
 239  * Handle to the statistics service
 240  */
 241 static struct GNUNET_STATISTICS_Handle *statistics;
 242
 243
 244 /**
 245  * Task run during shutdown.
 246  *
 247  * @param cls unused
 248  * @param tc unused
 249  */
 250 static void
 251 shutdown_task (void *cls,
 252                const struct GNUNET_SCHEDULER_TaskContext *tc)
 253 {
 254   struct ClientLookupHandle *clh;
 255   struct MonitorActivity *ma;
 256
 257   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 258               "Shutting down!\n");
 259   GNUNET_SERVER_notification_context_destroy (nc);
 260   while (NULL != (clh = clh_head))
 261   {
 262     GNUNET_SERVER_client_set_user_context (clh->client, (void *)NULL);
 263     GNS_resolver_lookup_cancel (clh->lookup);
 264     GNUNET_CONTAINER_DLL_remove (clh_head, clh_tail, clh);
 265     GNUNET_free (clh);
 266   }
 267
 268   GNS_interceptor_done ();
 269   GNS_resolver_done ();
 270   GNS_shorten_done ();
 271   while (NULL != (ma = ma_head))
 272   {
 273     GNUNET_DHT_put_cancel (ma->ph);
 274     GNUNET_CONTAINER_DLL_remove (ma_head,
 275                                  ma_tail,
 276                                  ma);
 277     GNUNET_free (ma);
 278   }
 279   if (NULL != statistics)
 280   {
 281     GNUNET_STATISTICS_destroy (statistics, GNUNET_NO);
 282     statistics = NULL;
 283   }
 284   if (GNUNET_SCHEDULER_NO_TASK != zone_publish_task)
 285   {
 286     GNUNET_SCHEDULER_cancel (zone_publish_task);
 287     zone_publish_task = GNUNET_SCHEDULER_NO_TASK;
 288   }
 289   if (NULL != namestore_iter)
 290   {
 291     GNUNET_NAMESTORE_zone_iteration_stop (namestore_iter);
 292     namestore_iter = NULL;
 293   }
 294   if (NULL != zmon)
 295   {
 296     GNUNET_NAMESTORE_zone_monitor_stop (zmon);
 297     zmon = NULL;
 298   }
 299   if (NULL != namestore_handle)
 300   {
 301     GNUNET_NAMESTORE_disconnect (namestore_handle);
 302     namestore_handle = NULL;
 303   }
 304   if (NULL != namecache_handle)
 305   {
 306     GNUNET_NAMECACHE_disconnect (namecache_handle);
 307     namecache_handle = NULL;
 308   }
 309   if (NULL != active_put)
 310   {
 311     GNUNET_DHT_put_cancel (active_put);
 312     active_put = NULL;
 313   }
 314   if (NULL != dht_handle)
 315   {
 316     GNUNET_DHT_disconnect (dht_handle);
 317     dht_handle = NULL;
 318   }
 319 }
 320
 321
 322 /**
 323  * Method called periodically that triggers iteration over authoritative records
 324  *
 325  * @param cls closure
 326  * @param tc task context
 327  */
 328 static void
 329 publish_zone_dht_next (void *cls,
 330                        const struct GNUNET_SCHEDULER_TaskContext *tc)
 331 {
 332   zone_publish_task = GNUNET_SCHEDULER_NO_TASK;
 333   GNUNET_NAMESTORE_zone_iterator_next (namestore_iter);
 334 }
 335
 336
 337 /**
 338  * Periodically iterate over our zone and store everything in dht
 339  *
 340  * @param cls NULL
 341  * @param tc task context
 342  */
 343 static void
 344 publish_zone_dht_start (void *cls,
 345                         const struct GNUNET_SCHEDULER_TaskContext *tc);
 346
 347
 348 /**
 349  * Continuation called from DHT once the PUT operation is done.
 350  *
 351  * @param cls closure, NULL if called from regular iteration,
 352  *        `struct MonitorActivity` if called from #handle_monitor_event.
 353  * @param success #GNUNET_OK on success
 354  */
 355 static void
 356 dht_put_continuation (void *cls,
 357                       int success)
 358 {
 359   struct MonitorActivity *ma = cls;
 360   struct GNUNET_TIME_Relative next_put_interval;
 361
 362   num_public_records++;
 363   if (NULL == ma)
 364   {
 365     active_put = NULL;
 366     if ( (num_public_records > last_num_public_records) &&
 367          (GNUNET_NO == first_zone_iteration) )
 368     {
 369       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 370                   "Last record count was lower than current record count.  Reducing interval.\n");
 371       put_interval = GNUNET_TIME_relative_divide (zone_publish_time_window,
 372                                                   num_public_records);
 373       next_put_interval = GNUNET_TIME_relative_divide (put_interval,
 374                                                        LATE_ITERATION_SPEEDUP_FACTOR);
 375     }
 376     else
 377       next_put_interval = put_interval;
 378
 379     GNUNET_STATISTICS_set (statistics,
 380                            "Current zone iteration interval (ms)",
 381                            next_put_interval.rel_value_us / 1000LL,
 382                            GNUNET_NO);
 383     zone_publish_task = GNUNET_SCHEDULER_add_delayed (next_put_interval,
 384                                                       &publish_zone_dht_next,
 385                                                       NULL);
 386   }
 387   else
 388   {
 389     GNUNET_CONTAINER_DLL_remove (ma_head,
 390                                  ma_tail,
 391                                  ma);
 392     GNUNET_free (ma);
 393   }
 394 }
 395
 396
 397 /**
 398  * Convert namestore records from the internal format to that
 399  * suitable for publication (removes private records, converts
 400  * to absolute expiration time).
 401  *
 402  * @param rd input records
 403  * @param rd_count size of the @a rd and @a rd_public arrays
 404  * @param rd_public where to write the converted records
 405  * @return number of records written to @a rd_public
 406  */
 407 static unsigned int
 408 convert_records_for_export (const struct GNUNET_GNSRECORD_Data *rd,
 409                             unsigned int rd_count,
 410                             struct GNUNET_GNSRECORD_Data *rd_public)
 411 {
 412   struct GNUNET_TIME_Absolute now;
 413   unsigned int rd_public_count;
 414   unsigned int i;
 415
 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   return rd_public_count;
 439 }
 440
 441
 442 /**
 443  * Store GNS records in the DHT.
 444  *
 445  * @param key key of the zone
 446  * @param label label to store under
 447  * @param rd_public public record data
 448  * @param rd_public_count number of records in @a rd_public
 449  * @param pc_arg closure argument to pass to the #dht_put_continuation
 450  * @return DHT PUT handle, NULL on error
 451  */
 452 static struct GNUNET_DHT_PutHandle *
 453 perform_dht_put (const struct GNUNET_CRYPTO_EcdsaPrivateKey *key,
 454                  const char *label,
 455                  const struct GNUNET_GNSRECORD_Data *rd_public,
 456                  unsigned int rd_public_count,
 457                  void *pc_arg)
 458 {
 459   struct GNUNET_GNSRECORD_Block *block;
 460   struct GNUNET_HashCode query;
 461   struct GNUNET_TIME_Absolute expire;
 462   size_t block_size;
 463   struct GNUNET_DHT_PutHandle *ret;
 464
 465   expire = GNUNET_GNSRECORD_record_get_expiration_time (rd_public_count,
 466                                                         rd_public);
 467   block = GNUNET_GNSRECORD_block_create (key,
 468                                          expire,
 469                                          label,
 470                                          rd_public,
 471                                          rd_public_count);
 472   block_size = ntohl (block->purpose.size)
 473     + sizeof (struct GNUNET_CRYPTO_EcdsaSignature)
 474     + sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey);
 475   GNUNET_GNSRECORD_query_from_private_key (key,
 476                                            label,
 477                                            &query);
 478   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 479               "Storing %u record(s) for label `%s' in DHT with expiration `%s' under key %s\n",
 480               rd_public_count,
 481               label,
 482               GNUNET_STRINGS_absolute_time_to_string (expire),
 483               GNUNET_h2s (&query));
 484   ret = GNUNET_DHT_put (dht_handle, &query,
 485                         DHT_GNS_REPLICATION_LEVEL,
 486                         GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE,
 487                         GNUNET_BLOCK_TYPE_GNS_NAMERECORD,
 488                         block_size,
 489                         block,
 490                         expire,
 491                         DHT_OPERATION_TIMEOUT,
 492                         &dht_put_continuation,
 493                         pc_arg);
 494   GNUNET_free (block);
 495   return ret;
 496 }
 497
 498
 499 /**
 500  * Function used to put all records successively into the DHT.
 501  *
 502  * @param cls the closure (NULL)
 503  * @param key the private key of the authority (ours)
 504  * @param name the name of the records, NULL once the iteration is done
 505  * @param rd_count the number of records in @a rd
 506  * @param rd the record data
 507  */
 508 static void
 509 put_gns_record (void *cls,
 510                 const struct GNUNET_CRYPTO_EcdsaPrivateKey *key,
 511                 const char *name,
 512                 unsigned int rd_count,
 513                 const struct GNUNET_GNSRECORD_Data *rd)
 514 {
 515   struct GNUNET_GNSRECORD_Data rd_public[rd_count];
 516   unsigned int rd_public_count;
 517
 518   if (NULL == name)
 519   {
 520     /* we're done with one iteration, calculate when to do the next one */
 521     namestore_iter = NULL;
 522     last_num_public_records = num_public_records;
 523     first_zone_iteration = GNUNET_NO;
 524     if (0 == num_public_records)
 525     {
 526       /**
 527        * If no records are known (startup) or none present
 528        * we can safely set the interval to the value for a single
 529        * record
 530        */
 531       put_interval = zone_publish_time_window;
 532       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG | GNUNET_ERROR_TYPE_BULK,
 533                   "No records in namestore database.\n");
 534     }
 535     else
 536     {
 537       zone_publish_time_window
 538         = GNUNET_TIME_relative_min (GNUNET_TIME_relative_divide (min_relative_record_time,
 539                                                                  4),
 540                                     zone_publish_time_window_default);
 541       put_interval = GNUNET_TIME_relative_divide (zone_publish_time_window,
 542                                                   num_public_records);
 543     }
 544     /* reset for next iteration */
 545     min_relative_record_time = GNUNET_TIME_UNIT_FOREVER_REL;
 546     put_interval = GNUNET_TIME_relative_max (MINIMUM_ZONE_ITERATION_INTERVAL,
 547                                              put_interval);
 548
 549     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 550                 "Zone iteration finished. Adjusted zone iteration interval to %s\n",
 551                 GNUNET_STRINGS_relative_time_to_string (put_interval, GNUNET_YES));
 552     GNUNET_STATISTICS_set (statistics,
 553                            "Current zone iteration interval (in ms)",
 554                            put_interval.rel_value_us / 1000LL,
 555                            GNUNET_NO);
 556     GNUNET_STATISTICS_update (statistics,
 557                               "Number of zone iterations",
 558                               1,
 559                               GNUNET_NO);
 560     GNUNET_STATISTICS_set (statistics,
 561                            "Number of public records in DHT",
 562                            last_num_public_records,
 563                            GNUNET_NO);
 564     if (0 == num_public_records)
 565       zone_publish_task = GNUNET_SCHEDULER_add_delayed (put_interval,
 566                                                         &publish_zone_dht_start,
 567                                                         NULL);
 568     else
 569       zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_start,
 570                                                     NULL);
 571     return;
 572   }
 573
 574   rd_public_count = convert_records_for_export (rd,
 575                                                 rd_count,
 576                                                 rd_public);
 577
 578   /* We got a set of records to publish */
 579   if (0 == rd_public_count)
 580   {
 581     zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_next,
 582                                                    NULL);
 583     return;
 584   }
 585
 586   active_put = perform_dht_put (key,
 587                                 name,
 588                                 rd_public,
 589                                 rd_public_count,
 590                                 NULL);
 591   if (NULL == active_put)
 592   {
 593     GNUNET_break (0);
 594     dht_put_continuation (NULL, GNUNET_NO);
 595   }
 596 }
 597
 598
 599 /**
 600  * Periodically iterate over our zone and store everything in dht
 601  *
 602  * @param cls NULL
 603  * @param tc task context
 604  */
 605 static void
 606 publish_zone_dht_start (void *cls,
 607                         const struct GNUNET_SCHEDULER_TaskContext *tc)
 608 {
 609   zone_publish_task = GNUNET_SCHEDULER_NO_TASK;
 610
 611   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 612               "Starting DHT zone update!\n");
 613   /* start counting again */
 614   num_public_records = 0;
 615   namestore_iter = GNUNET_NAMESTORE_zone_iteration_start (namestore_handle,
 616                                                           NULL, /* All zones */
 617                                                           &put_gns_record,
 618                                                           NULL);
 619 }
 620
 621
 622 /**
 623  * Process a record that was stored in the namestore
 624  * (invoked by the monitor).
 625  *
 626  * @param cls closure, NULL
 627  * @param zone private key of the zone; NULL on disconnect
 628  * @param label label of the records; NULL on disconnect
 629  * @param rd_count number of entries in @a rd array, 0 if label was deleted
 630  * @param rd array of records with data to store
 631  */
 632 static void
 633 handle_monitor_event (void *cls,
 634                       const struct GNUNET_CRYPTO_EcdsaPrivateKey *zone,
 635                       const char *label,
 636                       unsigned int rd_count,
 637                       const struct GNUNET_GNSRECORD_Data *rd)
 638 {
 639   struct GNUNET_GNSRECORD_Data rd_public[rd_count];
 640   unsigned int rd_public_count;
 641   struct MonitorActivity *ma;
 642
 643   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 644               "Received %u records for label `%s' via namestore monitor\n",
 645               rd_count,
 646               label);
 647   /* filter out records that are not public, and convert to
 648      absolute expiration time. */
 649   rd_public_count = convert_records_for_export (rd, rd_count,
 650                                                 rd_public);
 651   if (0 == rd_public_count)
 652     return; /* nothing to do */
 653   ma = GNUNET_new (struct MonitorActivity);
 654   ma->ph = perform_dht_put (zone, label,
 655                             rd, rd_count,
 656                             ma);
 657   if (NULL == ma->ph)
 658   {
 659     /* PUT failed, do not remember operation */
 660     GNUNET_free (ma);
 661     return;
 662   }
 663   GNUNET_CONTAINER_DLL_insert (ma_head,
 664                                ma_tail,
 665                                ma);
 666 }
 667
 668
 669 /* END DHT ZONE PROPAGATION */
 670
 671
 672 /**
 673  * Reply to client with the result from our lookup.
 674  *
 675  * @param cls the closure (our client lookup handle)
 676  * @param rd_count the number of records in @a rd
 677  * @param rd the record data
 678  */
 679 static void
 680 send_lookup_response (void* cls,
 681                       uint32_t rd_count,
 682                       const struct GNUNET_GNSRECORD_Data *rd)
 683 {
 684   struct ClientLookupHandle *clh = cls;
 685   struct GNUNET_GNS_ClientLookupResultMessage *rmsg;
 686   size_t len;
 687
 688   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 689               "Sending `%s' message with %d results\n",
 690               "LOOKUP_RESULT",
 691               rd_count);
 692
 693   len = GNUNET_GNSRECORD_records_get_size (rd_count, rd);
 694   rmsg = GNUNET_malloc (len + sizeof (struct GNUNET_GNS_ClientLookupResultMessage));
 695   rmsg->header.type = htons (GNUNET_MESSAGE_TYPE_GNS_LOOKUP_RESULT);
 696   rmsg->header.size = htons (len + sizeof(struct GNUNET_GNS_ClientLookupResultMessage));
 697   rmsg->id = clh->request_id;
 698   rmsg->rd_count = htonl (rd_count);
 699   GNUNET_GNSRECORD_records_serialize (rd_count, rd, len,
 700                                       (char*) &rmsg[1]);
 701   GNUNET_SERVER_notification_context_unicast (nc,
 702                                               clh->client,
 703                                               &rmsg->header,
 704                                               GNUNET_NO);
 705   GNUNET_free (rmsg);
 706   GNUNET_CONTAINER_DLL_remove (clh_head, clh_tail, clh);
 707   GNUNET_SERVER_client_set_user_context (clh->client, (void *)NULL);
 708   GNUNET_free (clh);
 709   GNUNET_STATISTICS_update (statistics,
 710                             "Completed lookups", 1,
 711                             GNUNET_NO);
 712   GNUNET_STATISTICS_update (statistics,
 713                             "Records resolved",
 714                             rd_count,
 715                             GNUNET_NO);
 716 }
 717
 718
 719 /**
 720  * Handle lookup requests from client
 721  *
 722  * @param cls the closure
 723  * @param client the client
 724  * @param message the message
 725  */
 726 static void
 727 handle_lookup (void *cls,
 728                struct GNUNET_SERVER_Client *client,
 729                const struct GNUNET_MessageHeader *message)
 730 {
 731   char name[GNUNET_DNSPARSER_MAX_NAME_LENGTH + 1];
 732   struct ClientLookupHandle *clh;
 733   char *nameptr = name;
 734   const char *utf_in;
 735   const struct GNUNET_CRYPTO_EcdsaPrivateKey *key;
 736   uint16_t msg_size;
 737   const struct GNUNET_GNS_ClientLookupMessage *sh_msg;
 738
 739   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 740               "Received `%s' message\n",
 741               "LOOKUP");
 742   msg_size = ntohs (message->size);
 743   if (msg_size < sizeof (struct GNUNET_GNS_ClientLookupMessage))
 744   {
 745     GNUNET_break (0);
 746     GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
 747     return;
 748   }
 749   sh_msg = (const struct GNUNET_GNS_ClientLookupMessage *) message;
 750   GNUNET_SERVER_notification_context_add (nc, client);
 751   if (GNUNET_YES == ntohs (sh_msg->have_key))
 752     key = &sh_msg->shorten_key;
 753   else
 754     key = NULL;
 755   utf_in = (const char *) &sh_msg[1];
 756   if ( ('\0' != utf_in[msg_size - sizeof (struct GNUNET_GNS_ClientLookupMessage) - 1]) ||
 757        (strlen (utf_in) > GNUNET_DNSPARSER_MAX_NAME_LENGTH) )
 758   {
 759     GNUNET_break (0);
 760     GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
 761     return;
 762   }
 763   GNUNET_STRINGS_utf8_tolower (utf_in, nameptr);
 764   GNUNET_SERVER_receive_done (client, GNUNET_OK);
 765
 766   clh = GNUNET_new (struct ClientLookupHandle);
 767   GNUNET_SERVER_client_set_user_context (client, clh);
 768   GNUNET_CONTAINER_DLL_insert (clh_head, clh_tail, clh);
 769   clh->client = client;
 770   clh->request_id = sh_msg->id;
 771   if ( (GNUNET_DNSPARSER_TYPE_A == ntohl (sh_msg->type)) &&
 772        (GNUNET_OK != v4_enabled) )
 773   {
 774     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 775                 "LOOKUP: Query for A record but AF_INET not supported!");
 776     send_lookup_response (clh, 0, NULL);
 777     return;
 778   }
 779   if ( (GNUNET_DNSPARSER_TYPE_AAAA == ntohl (sh_msg->type)) &&
 780        (GNUNET_OK != v6_enabled) )
 781   {
 782     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 783                 "LOOKUP: Query for AAAA record but AF_INET6 not supported!");
 784     send_lookup_response (clh, 0, NULL);
 785     return;
 786   }
 787   clh->lookup = GNS_resolver_lookup (&sh_msg->zone,
 788                                      ntohl (sh_msg->type),
 789                                      name,
 790                                      key,
 791                                      (enum GNUNET_GNS_LocalOptions) ntohs (sh_msg->options),
 792                                      &send_lookup_response, clh);
 793   GNUNET_STATISTICS_update (statistics,
 794                             "Lookup attempts",
 795                             1, GNUNET_NO);
 796 }
 797
 798
 799 /**
 800  * One of our clients disconnected, clean up after it.
 801  *
 802  * @param cls NULL
 803  * @param client the client that disconnected
 804  */
 805 static void
 806 notify_client_disconnect (void *cls,
 807                           struct GNUNET_SERVER_Client *client)
 808 {
 809   struct ClientLookupHandle *clh;
 810
 811   if (NULL == client)
 812     return;
 813   clh = GNUNET_SERVER_client_get_user_context (client, struct ClientLookupHandle);
 814   if (NULL == clh)
 815     return;
 816   GNS_resolver_lookup_cancel (clh->lookup);
 817   GNUNET_CONTAINER_DLL_remove (clh_head, clh_tail, clh);
 818   GNUNET_free (clh);
 819 }
 820
 821
 822 /**
 823  * The zone monitor is now in SYNC with the current state of the
 824  * name store.  Start to perform periodic iterations.
 825  *
 826  * @param cls NULL
 827  */
 828 static void
 829 monitor_sync_event (void *cls)
 830 {
 831   zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_start,
 832                                                 NULL);
 833 }
 834
 835
 836 /**
 837  * Process GNS requests.
 838  *
 839  * @param cls closure
 840  * @param server the initialized server
 841  * @param c configuration to use
 842  */
 843 static void
 844 run (void *cls, struct GNUNET_SERVER_Handle *server,
 845      const struct GNUNET_CONFIGURATION_Handle *c)
 846 {
 847   static const struct GNUNET_SERVER_MessageHandler handlers[] = {
 848     { &handle_lookup, NULL, GNUNET_MESSAGE_TYPE_GNS_LOOKUP, 0},
 849     {NULL, NULL, 0, 0}
 850   };
 851   struct GNUNET_CRYPTO_EcdsaPublicKey dns_root;
 852   unsigned long long max_parallel_bg_queries = 0;
 853   char *dns_root_name;
 854
 855   v6_enabled = GNUNET_NETWORK_test_pf (PF_INET6);
 856   v4_enabled = GNUNET_NETWORK_test_pf (PF_INET);
 857   min_relative_record_time = GNUNET_TIME_UNIT_FOREVER_REL;
 858   namestore_handle = GNUNET_NAMESTORE_connect (c);
 859   if (NULL == namestore_handle)
 860   {
 861     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 862                 _("Failed to connect to the namestore!\n"));
 863     GNUNET_SCHEDULER_shutdown ();
 864     return;
 865   }
 866   namecache_handle = GNUNET_NAMECACHE_connect (c);
 867   if (NULL == namecache_handle)
 868   {
 869     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 870                 _("Failed to connect to the namecache!\n"));
 871     GNUNET_SCHEDULER_shutdown ();
 872     return;
 873   }
 874
 875   put_interval = INITIAL_PUT_INTERVAL;
 876   zone_publish_time_window_default = DEFAULT_ZONE_PUBLISH_TIME_WINDOW;
 877   if (GNUNET_OK ==
 878       GNUNET_CONFIGURATION_get_value_time (c, "gns",
 879                                            "ZONE_PUBLISH_TIME_WINDOW",
 880                                            &zone_publish_time_window_default))
 881   {
 882     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 883                 "Time window for zone iteration: %s\n",
 884                 GNUNET_STRINGS_relative_time_to_string (zone_publish_time_window,
 885                                                         GNUNET_YES));
 886   }
 887   zone_publish_time_window = zone_publish_time_window_default;
 888   if (GNUNET_OK ==
 889       GNUNET_CONFIGURATION_get_value_number (c, "gns",
 890                                             "MAX_PARALLEL_BACKGROUND_QUERIES",
 891                                             &max_parallel_bg_queries))
 892   {
 893     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 894                 "Number of allowed parallel background queries: %llu\n",
 895                 max_parallel_bg_queries);
 896   }
 897
 898   dht_handle = GNUNET_DHT_connect (c,
 899                                    (unsigned int) max_parallel_bg_queries);
 900   if (NULL == dht_handle)
 901   {
 902     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 903                 _("Could not connect to DHT!\n"));
 904     GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
 905     return;
 906   }
 907
 908   if (GNUNET_OK ==
 909       GNUNET_CONFIGURATION_get_value_string (c, "gns", "DNS_ROOT",
 910                                              &dns_root_name))
 911   {
 912     if (GNUNET_OK !=
 913         GNUNET_CRYPTO_ecdsa_public_key_from_string (dns_root_name,
 914                                                     strlen (dns_root_name),
 915                                                     &dns_root))
 916     {
 917       GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
 918                                  "gns", "DNS_ROOT",
 919                                  _("valid public key required"));
 920       GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
 921       GNUNET_free (dns_root_name);
 922       return;
 923     }
 924     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 925                 "DNS hijacking with root `%s' enabled. Connecting to DNS service.\n",
 926                 dns_root_name);
 927     GNUNET_free (dns_root_name);
 928     if (GNUNET_SYSERR ==
 929         GNS_interceptor_init (&dns_root, c))
 930     {
 931       GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
 932       return;
 933     }
 934   }
 935   GNS_resolver_init (namecache_handle,
 936                      dht_handle,
 937                      c,
 938                      max_parallel_bg_queries);
 939   GNS_shorten_init (namestore_handle,
 940                     namecache_handle,
 941                     dht_handle);
 942   GNUNET_SERVER_disconnect_notify (server,
 943                                    &notify_client_disconnect,
 944                                    NULL);
 945   /* Schedule periodic put for our records. */
 946   first_zone_iteration = GNUNET_YES;
 947   GNUNET_SERVER_add_handlers (server, handlers);
 948   statistics = GNUNET_STATISTICS_create ("gns", c);
 949   nc = GNUNET_SERVER_notification_context_create (server, 1);
 950   zmon = GNUNET_NAMESTORE_zone_monitor_start (c,
 951                                               NULL,
 952                                               GNUNET_NO,
 953                                               &handle_monitor_event,
 954                                               &monitor_sync_event,
 955                                               NULL);
 956   GNUNET_break (NULL != zmon);
 957   GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
 958                                 &shutdown_task, NULL);
 959 }
 960
 961
 962 /**
 963  * The main function for the GNS service.
 964  *
 965  * @param argc number of arguments from the command line
 966  * @param argv command line arguments
 967  * @return 0 ok, 1 on error
 968  */
 969 int
 970 main (int argc, char *const *argv)
 971 {
 972   int ret;
 973
 974   ret =
 975       (GNUNET_OK ==
 976        GNUNET_SERVICE_run (argc, argv, "gns", GNUNET_SERVICE_OPTION_NONE, &run,
 977                            NULL)) ? 0 : 1;
 978   return ret;
 979 }
 980
 981 /* end of gnunet-service-gns.c */