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, 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 record in DHT with expiration `%s' under key %s\n",
 480               GNUNET_STRINGS_absolute_time_to_string (expire),
 481               GNUNET_h2s (&query));
 482   ret = GNUNET_DHT_put (dht_handle, &query,
 483                         DHT_GNS_REPLICATION_LEVEL,
 484                         GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE,
 485                         GNUNET_BLOCK_TYPE_GNS_NAMERECORD,
 486                         block_size,
 487                         block,
 488                         expire,
 489                         DHT_OPERATION_TIMEOUT,
 490                         &dht_put_continuation,
 491                         pc_arg);
 492   GNUNET_free (block);
 493   return ret;
 494 }
 495
 496
 497 /**
 498  * Function used to put all records successively into the DHT.
 499  *
 500  * @param cls the closure (NULL)
 501  * @param key the private key of the authority (ours)
 502  * @param name the name of the records, NULL once the iteration is done
 503  * @param rd_count the number of records in @a rd
 504  * @param rd the record data
 505  */
 506 static void
 507 put_gns_record (void *cls,
 508                 const struct GNUNET_CRYPTO_EcdsaPrivateKey *key,
 509                 const char *name,
 510                 unsigned int rd_count,
 511                 const struct GNUNET_GNSRECORD_Data *rd)
 512 {
 513   struct GNUNET_GNSRECORD_Data rd_public[rd_count];
 514   unsigned int rd_public_count;
 515
 516   if (NULL == name)
 517   {
 518     /* we're done with one iteration, calculate when to do the next one */
 519     namestore_iter = NULL;
 520     last_num_public_records = num_public_records;
 521     first_zone_iteration = GNUNET_NO;
 522     if (0 == num_public_records)
 523     {
 524       /**
 525        * If no records are known (startup) or none present
 526        * we can safely set the interval to the value for a single
 527        * record
 528        */
 529       put_interval = zone_publish_time_window;
 530       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG | GNUNET_ERROR_TYPE_BULK,
 531                   "No records in namestore database.\n");
 532     }
 533     else
 534     {
 535       zone_publish_time_window
 536         = GNUNET_TIME_relative_min (GNUNET_TIME_relative_divide (min_relative_record_time,
 537                                                                  4),
 538                                     zone_publish_time_window_default);
 539       put_interval = GNUNET_TIME_relative_divide (zone_publish_time_window,
 540                                                   num_public_records);
 541     }
 542     /* reset for next iteration */
 543     min_relative_record_time = GNUNET_TIME_UNIT_FOREVER_REL;
 544     put_interval = GNUNET_TIME_relative_max (MINIMUM_ZONE_ITERATION_INTERVAL,
 545                                              put_interval);
 546
 547     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 548                 "Zone iteration finished. Adjusted zone iteration interval to %s\n",
 549                 GNUNET_STRINGS_relative_time_to_string (put_interval, GNUNET_YES));
 550     GNUNET_STATISTICS_set (statistics,
 551                            "Current zone iteration interval (in ms)",
 552                            put_interval.rel_value_us / 1000LL,
 553                            GNUNET_NO);
 554     GNUNET_STATISTICS_update (statistics,
 555                               "Number of zone iterations",
 556                               1,
 557                               GNUNET_NO);
 558     GNUNET_STATISTICS_set (statistics,
 559                            "Number of public records in DHT",
 560                            last_num_public_records,
 561                            GNUNET_NO);
 562     if (0 == num_public_records)
 563       zone_publish_task = GNUNET_SCHEDULER_add_delayed (put_interval,
 564                                                         &publish_zone_dht_start,
 565                                                         NULL);
 566     else
 567       zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_start,
 568                                                     NULL);
 569     return;
 570   }
 571
 572   rd_public_count = convert_records_for_export (rd,
 573                                                 rd_count,
 574                                                 rd_public);
 575
 576   /* We got a set of records to publish */
 577   if (0 == rd_public_count)
 578   {
 579     zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_next,
 580                                                    NULL);
 581     return;
 582   }
 583
 584   active_put = perform_dht_put (key,
 585                                 name,
 586                                 rd_public,
 587                                 rd_public_count,
 588                                 NULL);
 589   if (NULL == active_put)
 590   {
 591     GNUNET_break (0);
 592     dht_put_continuation (NULL, GNUNET_NO);
 593   }
 594 }
 595
 596
 597 /**
 598  * Periodically iterate over our zone and store everything in dht
 599  *
 600  * @param cls NULL
 601  * @param tc task context
 602  */
 603 static void
 604 publish_zone_dht_start (void *cls,
 605                         const struct GNUNET_SCHEDULER_TaskContext *tc)
 606 {
 607   zone_publish_task = GNUNET_SCHEDULER_NO_TASK;
 608
 609   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 610               "Starting DHT zone update!\n");
 611   /* start counting again */
 612   num_public_records = 0;
 613   namestore_iter = GNUNET_NAMESTORE_zone_iteration_start (namestore_handle,
 614                                                           NULL, /* All zones */
 615                                                           &put_gns_record,
 616                                                           NULL);
 617 }
 618
 619
 620 /**
 621  * Process a record that was stored in the namestore
 622  * (invoked by the monitor).
 623  *
 624  * @param cls closure, NULL
 625  * @param zone private key of the zone; NULL on disconnect
 626  * @param label label of the records; NULL on disconnect
 627  * @param rd_count number of entries in @a rd array, 0 if label was deleted
 628  * @param rd array of records with data to store
 629  */
 630 static void
 631 handle_monitor_event (void *cls,
 632                       const struct GNUNET_CRYPTO_EcdsaPrivateKey *zone,
 633                       const char *label,
 634                       unsigned int rd_count,
 635                       const struct GNUNET_GNSRECORD_Data *rd)
 636 {
 637   struct GNUNET_GNSRECORD_Data rd_public[rd_count];
 638   unsigned int rd_public_count;
 639   struct MonitorActivity *ma;
 640
 641   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 642               "Received %u records for label `%s' via namestore monitor\n",
 643               rd_count,
 644               label);
 645   /* filter out records that are not public, and convert to
 646      absolute expiration time. */
 647   rd_public_count = convert_records_for_export (rd, rd_count,
 648                                                 rd_public);
 649   if (0 == rd_public_count)
 650     return; /* nothing to do */
 651   ma = GNUNET_new (struct MonitorActivity);
 652   ma->ph = perform_dht_put (zone, label,
 653                             rd, rd_count,
 654                             ma);
 655   if (NULL == ma->ph)
 656   {
 657     /* PUT failed, do not remember operation */
 658     GNUNET_free (ma);
 659     return;
 660   }
 661   GNUNET_CONTAINER_DLL_insert (ma_head,
 662                                ma_tail,
 663                                ma);
 664 }
 665
 666
 667 /* END DHT ZONE PROPAGATION */
 668
 669
 670 /**
 671  * Reply to client with the result from our lookup.
 672  *
 673  * @param cls the closure (our client lookup handle)
 674  * @param rd_count the number of records in @a rd
 675  * @param rd the record data
 676  */
 677 static void
 678 send_lookup_response (void* cls,
 679                       uint32_t rd_count,
 680                       const struct GNUNET_GNSRECORD_Data *rd)
 681 {
 682   struct ClientLookupHandle *clh = cls;
 683   struct GNUNET_GNS_ClientLookupResultMessage *rmsg;
 684   size_t len;
 685
 686   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 687               "Sending `%s' message with %d results\n",
 688               "LOOKUP_RESULT",
 689               rd_count);
 690
 691   len = GNUNET_GNSRECORD_records_get_size (rd_count, rd);
 692   rmsg = GNUNET_malloc (len + sizeof (struct GNUNET_GNS_ClientLookupResultMessage));
 693   rmsg->header.type = htons (GNUNET_MESSAGE_TYPE_GNS_LOOKUP_RESULT);
 694   rmsg->header.size = htons (len + sizeof(struct GNUNET_GNS_ClientLookupResultMessage));
 695   rmsg->id = clh->request_id;
 696   rmsg->rd_count = htonl (rd_count);
 697   GNUNET_GNSRECORD_records_serialize (rd_count, rd, len,
 698                                       (char*) &rmsg[1]);
 699   GNUNET_SERVER_notification_context_unicast (nc,
 700                                               clh->client,
 701                                               &rmsg->header,
 702                                               GNUNET_NO);
 703   GNUNET_free (rmsg);
 704   GNUNET_CONTAINER_DLL_remove (clh_head, clh_tail, clh);
 705   GNUNET_SERVER_client_set_user_context (clh->client, NULL);
 706   GNUNET_free (clh);
 707   GNUNET_STATISTICS_update (statistics,
 708                             "Completed lookups", 1,
 709                             GNUNET_NO);
 710   GNUNET_STATISTICS_update (statistics,
 711                             "Records resolved",
 712                             rd_count,
 713                             GNUNET_NO);
 714 }
 715
 716
 717 /**
 718  * Handle lookup requests from client
 719  *
 720  * @param cls the closure
 721  * @param client the client
 722  * @param message the message
 723  */
 724 static void
 725 handle_lookup (void *cls,
 726                struct GNUNET_SERVER_Client *client,
 727                const struct GNUNET_MessageHeader *message)
 728 {
 729   char name[GNUNET_DNSPARSER_MAX_NAME_LENGTH + 1];
 730   struct ClientLookupHandle *clh;
 731   char *nameptr = name;
 732   const char *utf_in;
 733   const struct GNUNET_CRYPTO_EcdsaPrivateKey *key;
 734   uint16_t msg_size;
 735   const struct GNUNET_GNS_ClientLookupMessage *sh_msg;
 736
 737   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 738               "Received `%s' message\n",
 739               "LOOKUP");
 740   msg_size = ntohs (message->size);
 741   if (msg_size < sizeof (struct GNUNET_GNS_ClientLookupMessage))
 742   {
 743     GNUNET_break (0);
 744     GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
 745     return;
 746   }
 747   sh_msg = (const struct GNUNET_GNS_ClientLookupMessage *) message;
 748   GNUNET_SERVER_notification_context_add (nc, client);
 749   if (GNUNET_YES == ntohs (sh_msg->have_key))
 750     key = &sh_msg->shorten_key;
 751   else
 752     key = NULL;
 753   utf_in = (const char *) &sh_msg[1];
 754   if ( ('\0' != utf_in[msg_size - sizeof (struct GNUNET_GNS_ClientLookupMessage) - 1]) ||
 755        (strlen (utf_in) > GNUNET_DNSPARSER_MAX_NAME_LENGTH) )
 756   {
 757     GNUNET_break (0);
 758     GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
 759     return;
 760   }
 761   GNUNET_STRINGS_utf8_tolower (utf_in, nameptr);
 762   GNUNET_SERVER_receive_done (client, GNUNET_OK);
 763
 764   clh = GNUNET_new (struct ClientLookupHandle);
 765   GNUNET_SERVER_client_set_user_context (client, clh);
 766   GNUNET_CONTAINER_DLL_insert (clh_head, clh_tail, clh);
 767   clh->client = client;
 768   clh->request_id = sh_msg->id;
 769   if ( (GNUNET_DNSPARSER_TYPE_A == ntohl (sh_msg->type)) &&
 770        (GNUNET_OK != v4_enabled) )
 771   {
 772     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 773                 "LOOKUP: Query for A record but AF_INET not supported!");
 774     send_lookup_response (clh, 0, NULL);
 775     return;
 776   }
 777   if ( (GNUNET_DNSPARSER_TYPE_AAAA == ntohl (sh_msg->type)) &&
 778        (GNUNET_OK != v6_enabled) )
 779   {
 780     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 781                 "LOOKUP: Query for AAAA record but AF_INET6 not supported!");
 782     send_lookup_response (clh, 0, NULL);
 783     return;
 784   }
 785   clh->lookup = GNS_resolver_lookup (&sh_msg->zone,
 786                                      ntohl (sh_msg->type),
 787                                      name,
 788                                      key,
 789                                      ntohl (sh_msg->only_cached),
 790                                      &send_lookup_response, clh);
 791   GNUNET_STATISTICS_update (statistics,
 792                             "Lookup attempts",
 793                             1, GNUNET_NO);
 794 }
 795
 796
 797 /**
 798  * One of our clients disconnected, clean up after it.
 799  *
 800  * @param cls NULL
 801  * @param client the client that disconnected
 802  */
 803 static void
 804 notify_client_disconnect (void *cls,
 805                           struct GNUNET_SERVER_Client *client)
 806 {
 807   struct ClientLookupHandle *clh;
 808
 809   if (NULL == client)
 810     return;
 811   clh = GNUNET_SERVER_client_get_user_context (client, struct ClientLookupHandle);
 812   if (NULL == clh)
 813     return;
 814   GNS_resolver_lookup_cancel (clh->lookup);
 815   GNUNET_CONTAINER_DLL_remove (clh_head, clh_tail, clh);
 816   GNUNET_free (clh);
 817 }
 818
 819
 820 /**
 821  * The zone monitor is now in SYNC with the current state of the
 822  * name store.  Start to perform periodic iterations.
 823  *
 824  * @param cls NULL
 825  */
 826 static void
 827 monitor_sync_event (void *cls)
 828 {
 829   zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_start,
 830                                                 NULL);
 831 }
 832
 833
 834 /**
 835  * Process GNS requests.
 836  *
 837  * @param cls closure
 838  * @param server the initialized server
 839  * @param c configuration to use
 840  */
 841 static void
 842 run (void *cls, struct GNUNET_SERVER_Handle *server,
 843      const struct GNUNET_CONFIGURATION_Handle *c)
 844 {
 845   static const struct GNUNET_SERVER_MessageHandler handlers[] = {
 846     { &handle_lookup, NULL, GNUNET_MESSAGE_TYPE_GNS_LOOKUP, 0},
 847     {NULL, NULL, 0, 0}
 848   };
 849   struct GNUNET_CRYPTO_EcdsaPublicKey dns_root;
 850   unsigned long long max_parallel_bg_queries = 0;
 851   char *dns_root_name;
 852
 853   v6_enabled = GNUNET_NETWORK_test_pf (PF_INET6);
 854   v4_enabled = GNUNET_NETWORK_test_pf (PF_INET);
 855   min_relative_record_time = GNUNET_TIME_UNIT_FOREVER_REL;
 856   namestore_handle = GNUNET_NAMESTORE_connect (c);
 857   if (NULL == namestore_handle)
 858   {
 859     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 860                 _("Failed to connect to the namestore!\n"));
 861     GNUNET_SCHEDULER_shutdown ();
 862     return;
 863   }
 864   namecache_handle = GNUNET_NAMECACHE_connect (c);
 865   if (NULL == namecache_handle)
 866   {
 867     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 868                 _("Failed to connect to the namecache!\n"));
 869     GNUNET_SCHEDULER_shutdown ();
 870     return;
 871   }
 872
 873   put_interval = INITIAL_PUT_INTERVAL;
 874   zone_publish_time_window_default = DEFAULT_ZONE_PUBLISH_TIME_WINDOW;
 875   if (GNUNET_OK ==
 876       GNUNET_CONFIGURATION_get_value_time (c, "gns",
 877                                            "ZONE_PUBLISH_TIME_WINDOW",
 878                                            &zone_publish_time_window_default))
 879   {
 880     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 881                 "Time window for zone iteration: %s\n",
 882                 GNUNET_STRINGS_relative_time_to_string (zone_publish_time_window,
 883                                                         GNUNET_YES));
 884   }
 885   zone_publish_time_window = zone_publish_time_window_default;
 886   if (GNUNET_OK ==
 887       GNUNET_CONFIGURATION_get_value_number (c, "gns",
 888                                             "MAX_PARALLEL_BACKGROUND_QUERIES",
 889                                             &max_parallel_bg_queries))
 890   {
 891     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 892                 "Number of allowed parallel background queries: %llu\n",
 893                 max_parallel_bg_queries);
 894   }
 895
 896   dht_handle = GNUNET_DHT_connect (c,
 897                                    (unsigned int) max_parallel_bg_queries);
 898   if (NULL == dht_handle)
 899   {
 900     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 901                 _("Could not connect to DHT!\n"));
 902     GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
 903     return;
 904   }
 905
 906   if (GNUNET_OK ==
 907       GNUNET_CONFIGURATION_get_value_string (c, "gns", "DNS_ROOT",
 908                                              &dns_root_name))
 909   {
 910     if (GNUNET_OK !=
 911         GNUNET_CRYPTO_ecdsa_public_key_from_string (dns_root_name,
 912                                                     strlen (dns_root_name),
 913                                                     &dns_root))
 914     {
 915       GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
 916                                  "gns", "DNS_ROOT",
 917                                  _("valid public key required"));
 918       GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
 919       GNUNET_free (dns_root_name);
 920       return;
 921     }
 922     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 923                 "DNS hijacking with root `%s' enabled. Connecting to DNS service.\n",
 924                 dns_root_name);
 925     GNUNET_free (dns_root_name);
 926     if (GNUNET_SYSERR ==
 927         GNS_interceptor_init (&dns_root, c))
 928     {
 929       GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
 930       return;
 931     }
 932   }
 933   GNS_resolver_init (namecache_handle,
 934                      dht_handle,
 935                      c,
 936                      max_parallel_bg_queries);
 937   GNS_shorten_init (namestore_handle,
 938                     namecache_handle,
 939                     dht_handle);
 940   GNUNET_SERVER_disconnect_notify (server,
 941                                    &notify_client_disconnect,
 942                                    NULL);
 943   /* Schedule periodic put for our records. */
 944   first_zone_iteration = GNUNET_YES;
 945   GNUNET_SERVER_add_handlers (server, handlers);
 946   statistics = GNUNET_STATISTICS_create ("gns", c);
 947   nc = GNUNET_SERVER_notification_context_create (server, 1);
 948   zmon = GNUNET_NAMESTORE_zone_monitor_start (c,
 949                                               NULL,
 950                                               GNUNET_NO,
 951                                               &handle_monitor_event,
 952                                               &monitor_sync_event,
 953                                               NULL);
 954   GNUNET_break (NULL != zmon);
 955   GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
 956                                 &shutdown_task, NULL);
 957 }
 958
 959
 960 /**
 961  * The main function for the GNS service.
 962  *
 963  * @param argc number of arguments from the command line
 964  * @param argv command line arguments
 965  * @return 0 ok, 1 on error
 966  */
 967 int
 968 main (int argc, char *const *argv)
 969 {
 970   int ret;
 971
 972   ret =
 973       (GNUNET_OK ==
 974        GNUNET_SERVICE_run (argc, argv, "gns", GNUNET_SERVICE_OPTION_NONE, &run,
 975                            NULL)) ? 0 : 1;
 976   return ret;
 977 }
 978
 979 /* end of gnunet-service-gns.c */