2 This file is part of GNUnet.
3 (C) 2011-2013 Christian Grothoff (and other contributing authors)
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.
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.
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.
21 * @file gns/gnunet-service-gns.c
22 * @brief GNU Name System (main service)
23 * @author Martin Schanzenbach
24 * @author Christian Grothoff
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"
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"
42 * The initial interval in milliseconds btween puts in
45 #define INITIAL_PUT_INTERVAL GNUNET_TIME_UNIT_MILLISECONDS
48 * The upper bound for the zone iteration interval in milliseconds
50 #define MINIMUM_ZONE_ITERATION_INTERVAL GNUNET_TIME_UNIT_SECONDS
53 * The default put interval for the zone iteration. In case
56 #define DEFAULT_ZONE_PUBLISH_TIME_WINDOW GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 4)
59 * The factor the current zone iteration interval is divided by for each
60 * additional new record
62 #define LATE_ITERATION_SPEEDUP_FACTOR 2
65 * How long until a DHT PUT attempt should time out?
67 #define DHT_OPERATION_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 60)
70 * What replication level do we use for DHT PUT operations?
72 #define DHT_GNS_REPLICATION_LEVEL 5
76 * Handle to a lookup operation from api
78 struct ClientLookupHandle
82 * We keep these in a DLL.
84 struct ClientLookupHandle *next;
87 * We keep these in a DLL.
89 struct ClientLookupHandle *prev;
92 * Handle to the requesting client
94 struct GNUNET_SERVER_Client *client;
97 * Active handle for the lookup.
99 struct GNS_ResolverHandle *lookup;
110 * Our handle to the DHT
112 static struct GNUNET_DHT_Handle *dht_handle;
115 * Active DHT put operation (or NULL)
117 static struct GNUNET_DHT_PutHandle *active_put;
120 * Our handle to the namestore service
122 static struct GNUNET_NAMESTORE_Handle *namestore_handle;
125 * Our handle to the namecache service
127 static struct GNUNET_NAMECACHE_Handle *namecache_handle;
130 * Handle to iterate over our authoritative zone in namestore
132 static struct GNUNET_NAMESTORE_ZoneIterator *namestore_iter;
135 * Our notification context.
137 static struct GNUNET_SERVER_NotificationContext *nc;
142 static struct ClientLookupHandle *clh_head;
147 static struct ClientLookupHandle *clh_tail;
150 * Useful for zone update for DHT put
152 static unsigned long long num_public_records;
155 * Last seen record count
157 static unsigned long long last_num_public_records;
160 * Minimum relative expiration time of records seem during the current
163 static struct GNUNET_TIME_Relative min_relative_record_time;
166 * Zone iteration PUT interval.
168 static struct GNUNET_TIME_Relative put_interval;
171 * Default time window for zone iteration
173 static struct GNUNET_TIME_Relative zone_publish_time_window_default;
176 * Time window for zone iteration, adjusted based on relative record
177 * expiration times in our zone.
179 static struct GNUNET_TIME_Relative zone_publish_time_window;
184 static GNUNET_SCHEDULER_TaskIdentifier zone_publish_task;
187 * #GNUNET_YES if zone has never been published before
189 static int first_zone_iteration;
192 * #GNUNET_YES if ipv6 is supported
194 static int v6_enabled;
197 * #GNUNET_YES if ipv4 is supported
199 static int v4_enabled;
202 * Handle to the statistics service
204 static struct GNUNET_STATISTICS_Handle *statistics;
208 * Task run during shutdown.
214 shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
216 struct ClientLookupHandle *clh;
218 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
220 GNUNET_SERVER_notification_context_destroy (nc);
221 while (NULL != (clh = clh_head))
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);
229 GNS_interceptor_done ();
230 GNS_resolver_done ();
232 if (NULL != statistics)
234 GNUNET_STATISTICS_destroy (statistics, GNUNET_NO);
237 if (GNUNET_SCHEDULER_NO_TASK != zone_publish_task)
239 GNUNET_SCHEDULER_cancel (zone_publish_task);
240 zone_publish_task = GNUNET_SCHEDULER_NO_TASK;
242 if (NULL != namestore_iter)
244 GNUNET_NAMESTORE_zone_iteration_stop (namestore_iter);
245 namestore_iter = NULL;
247 if (NULL != namestore_handle)
249 GNUNET_NAMESTORE_disconnect (namestore_handle);
250 namestore_handle = NULL;
252 if (NULL != namecache_handle)
254 GNUNET_NAMECACHE_disconnect (namecache_handle);
255 namecache_handle = NULL;
257 if (NULL != active_put)
259 GNUNET_DHT_put_cancel (active_put);
262 if (NULL != dht_handle)
264 GNUNET_DHT_disconnect (dht_handle);
271 * Method called periodically that triggers iteration over authoritative records
274 * @param tc task context
277 publish_zone_dht_next (void *cls,
278 const struct GNUNET_SCHEDULER_TaskContext *tc)
280 zone_publish_task = GNUNET_SCHEDULER_NO_TASK;
281 GNUNET_NAMESTORE_zone_iterator_next (namestore_iter);
286 * Periodically iterate over our zone and store everything in dht
289 * @param tc task context
292 publish_zone_dht_start (void *cls,
293 const struct GNUNET_SCHEDULER_TaskContext *tc);
297 * Continuation called from DHT once the PUT operation is done.
299 * @param cls closure, NULL
300 * @param success #GNUNET_OK on success
303 dht_put_continuation (void *cls,
306 struct GNUNET_TIME_Relative next_put_interval;
309 num_public_records++;
310 if ( (num_public_records > last_num_public_records) &&
311 (GNUNET_NO == first_zone_iteration) )
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,
317 next_put_interval = GNUNET_TIME_relative_divide (put_interval,
318 LATE_ITERATION_SPEEDUP_FACTOR);
321 next_put_interval = put_interval;
323 GNUNET_STATISTICS_set (statistics,
324 "Current zone iteration interval (ms)",
325 next_put_interval.rel_value_us / 1000LL,
327 zone_publish_task = GNUNET_SCHEDULER_add_delayed (next_put_interval,
328 &publish_zone_dht_next,
334 * Function used to put all records successively into the DHT.
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
343 put_gns_record (void *cls,
344 const struct GNUNET_CRYPTO_EcdsaPrivateKey *key,
346 unsigned int rd_count,
347 const struct GNUNET_GNSRECORD_Data *rd)
349 struct GNUNET_GNSRECORD_Block *block;
350 struct GNUNET_HashCode query;
351 struct GNUNET_TIME_Absolute expire;
352 struct GNUNET_TIME_Absolute now;
354 struct GNUNET_GNSRECORD_Data rd_public[rd_count];
355 unsigned int rd_public_count;
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)
367 * If no records are known (startup) or none present
368 * we can safely set the interval to the value for a single
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");
377 zone_publish_time_window
378 = GNUNET_TIME_relative_min (GNUNET_TIME_relative_divide (min_relative_record_time,
380 zone_publish_time_window_default);
381 put_interval = GNUNET_TIME_relative_divide (zone_publish_time_window,
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,
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,
396 GNUNET_STATISTICS_update (statistics,
397 "Number of zone iterations",
400 GNUNET_STATISTICS_set (statistics,
401 "Number of public records in DHT",
402 last_num_public_records,
404 if (0 == num_public_records)
405 zone_publish_task = GNUNET_SCHEDULER_add_delayed (put_interval,
406 &publish_zone_dht_start,
409 zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_start,
414 /* filter out records that are not public, and convert to
415 absolute expiration time. */
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)))
422 rd_public[rd_public_count] = rd[i];
423 if (0 != (rd[i].flags & GNUNET_GNSRECORD_RF_RELATIVE_EXPIRATION))
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);
431 else if (rd_public[rd_public_count].expiration_time < now.abs_value_us)
433 /* record already expired, skip it */
439 /* We got a set of records to publish */
440 if (0 == rd_public_count)
442 zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_next,
446 expire = GNUNET_GNSRECORD_record_get_expiration_time (rd_public_count,
448 block = GNUNET_GNSRECORD_block_create (key,
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,
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,
469 DHT_OPERATION_TIMEOUT,
470 &dht_put_continuation,
472 if (NULL == active_put)
475 dht_put_continuation (NULL, GNUNET_NO);
482 * Periodically iterate over our zone and store everything in dht
485 * @param tc task context
488 publish_zone_dht_start (void *cls,
489 const struct GNUNET_SCHEDULER_TaskContext *tc)
491 zone_publish_task = GNUNET_SCHEDULER_NO_TASK;
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 */
504 /* END DHT ZONE PROPAGATION */
508 * Reply to client with the result from our lookup.
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
515 send_lookup_response (void* cls,
517 const struct GNUNET_GNSRECORD_Data *rd)
519 struct ClientLookupHandle *clh = cls;
520 struct GNUNET_GNS_ClientLookupResultMessage *rmsg;
523 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
524 "Sending `%s' message with %d results\n",
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,
536 GNUNET_SERVER_notification_context_unicast (nc,
541 GNUNET_CONTAINER_DLL_remove (clh_head, clh_tail, clh);
542 GNUNET_SERVER_client_set_user_context (clh->client, NULL);
544 GNUNET_STATISTICS_update (statistics,
545 "Completed lookups", 1,
547 GNUNET_STATISTICS_update (statistics,
555 * Handle lookup requests from client
557 * @param cls the closure
558 * @param client the client
559 * @param message the message
562 handle_lookup (void *cls,
563 struct GNUNET_SERVER_Client *client,
564 const struct GNUNET_MessageHeader *message)
566 char name[GNUNET_DNSPARSER_MAX_NAME_LENGTH + 1];
567 struct ClientLookupHandle *clh;
568 char *nameptr = name;
570 const struct GNUNET_CRYPTO_EcdsaPrivateKey *key;
572 const struct GNUNET_GNS_ClientLookupMessage *sh_msg;
574 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
575 "Received `%s' message\n",
577 msg_size = ntohs (message->size);
578 if (msg_size < sizeof (struct GNUNET_GNS_ClientLookupMessage))
581 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
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;
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) )
595 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
598 GNUNET_STRINGS_utf8_tolower (utf_in, &nameptr);
599 GNUNET_SERVER_receive_done (client, GNUNET_OK);
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) )
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);
614 if ( (GNUNET_DNSPARSER_TYPE_AAAA == ntohl (sh_msg->type)) &&
615 (GNUNET_OK != v6_enabled) )
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);
622 clh->lookup = GNS_resolver_lookup (&sh_msg->zone,
623 ntohl (sh_msg->type),
626 ntohl (sh_msg->only_cached),
627 &send_lookup_response, clh);
628 GNUNET_STATISTICS_update (statistics,
635 * One of our clients disconnected, clean up after it.
638 * @param client the client that disconnected
641 notify_client_disconnect (void *cls,
642 struct GNUNET_SERVER_Client *client)
644 struct ClientLookupHandle *clh;
648 clh = GNUNET_SERVER_client_get_user_context (client, struct ClientLookupHandle);
651 GNS_resolver_lookup_cancel (clh->lookup);
652 GNUNET_CONTAINER_DLL_remove (clh_head, clh_tail, clh);
658 * Process GNS requests.
661 * @param server the initialized server
662 * @param c configuration to use
665 run (void *cls, struct GNUNET_SERVER_Handle *server,
666 const struct GNUNET_CONFIGURATION_Handle *c)
668 static const struct GNUNET_SERVER_MessageHandler handlers[] = {
669 { &handle_lookup, NULL, GNUNET_MESSAGE_TYPE_GNS_LOOKUP, 0},
672 struct GNUNET_CRYPTO_EcdsaPublicKey dns_root;
673 unsigned long long max_parallel_bg_queries = 0;
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)
682 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
683 _("Failed to connect to the namestore!\n"));
684 GNUNET_SCHEDULER_shutdown ();
687 namecache_handle = GNUNET_NAMECACHE_connect (c);
688 if (NULL == namecache_handle)
690 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
691 _("Failed to connect to the namecache!\n"));
692 GNUNET_SCHEDULER_shutdown ();
696 put_interval = INITIAL_PUT_INTERVAL;
697 zone_publish_time_window_default = DEFAULT_ZONE_PUBLISH_TIME_WINDOW;
699 GNUNET_CONFIGURATION_get_value_time (c, "gns",
700 "ZONE_PUBLISH_TIME_WINDOW",
701 &zone_publish_time_window_default))
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,
708 zone_publish_time_window = zone_publish_time_window_default;
710 GNUNET_CONFIGURATION_get_value_number (c, "gns",
711 "MAX_PARALLEL_BACKGROUND_QUERIES",
712 &max_parallel_bg_queries))
714 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
715 "Number of allowed parallel background queries: %llu\n",
716 max_parallel_bg_queries);
719 dht_handle = GNUNET_DHT_connect (c,
720 (unsigned int) max_parallel_bg_queries);
721 if (NULL == dht_handle)
723 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
724 _("Could not connect to DHT!\n"));
725 GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
730 GNUNET_CONFIGURATION_get_value_string (c, "gns", "DNS_ROOT",
734 GNUNET_CRYPTO_ecdsa_public_key_from_string (dns_root_name,
735 strlen (dns_root_name),
738 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
740 _("valid public key required"));
741 GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
742 GNUNET_free (dns_root_name);
745 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
746 "DNS hijacking with root `%s' enabled. Connecting to DNS service.\n",
748 GNUNET_free (dns_root_name);
750 GNS_interceptor_init (&dns_root, c))
752 GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
756 GNS_resolver_init (namecache_handle,
759 max_parallel_bg_queries);
760 GNS_shorten_init (namestore_handle,
763 GNUNET_SERVER_disconnect_notify (server,
764 ¬ify_client_disconnect,
766 /* Schedule periodic put for our records. */
767 first_zone_iteration = GNUNET_YES;
768 GNUNET_SERVER_add_handlers (server, handlers);
769 statistics = GNUNET_STATISTICS_create ("gns", c);
770 nc = GNUNET_SERVER_notification_context_create (server, 1);
771 zone_publish_task = GNUNET_SCHEDULER_add_now (&publish_zone_dht_start,
773 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
774 &shutdown_task, NULL);
779 * The main function for the GNS service.
781 * @param argc number of arguments from the command line
782 * @param argv command line arguments
783 * @return 0 ok, 1 on error
786 main (int argc, char *const *argv)
792 GNUNET_SERVICE_run (argc, argv, "gns", GNUNET_SERVICE_OPTION_NONE, &run,
797 /* end of gnunet-service-gns.c */