2 This file is part of GNUnet.
3 (C) 2009, 2010, 2011 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
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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.
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17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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22 * @file nse/gnunet-service-nse.c
23 * @brief network size estimation service
24 * @author Nathan Evans
25 * @author Christian Grothoff
27 * The purpose of this service is to estimate the size of the network.
28 * Given a specified interval, each peer hashes the most recent
29 * timestamp which is evenly divisible by that interval. This hash is
30 * compared in distance to the peer identity to choose an offset. The
31 * closer the peer identity to the hashed timestamp, the earlier the
32 * peer sends out a "nearest peer" message. The closest peer's
33 * message should thus be received before any others, which stops
34 * those peer from sending their messages at a later duration. So
35 * every peer should receive the same nearest peer message, and from
36 * this can calculate the expected number of peers in the network.
39 #include "gnunet_util_lib.h"
40 #include "gnunet_constants.h"
41 #include "gnunet_protocols.h"
42 #include "gnunet_signatures.h"
43 #include "gnunet_statistics_service.h"
44 #include "gnunet_core_service.h"
45 #include "gnunet_nse_service.h"
49 * Should messages be delayed randomly? This option should be set to
50 * GNUNET_NO only for experiments, not in production. It should also
51 * be removed once the initial experiments have been completed.
53 #define USE_RANDOM_DELAYS GNUNET_YES
56 * Should we generate a histogram with the time stamps of when we received
57 * NSE messages to disk? (for performance evaluation only, not useful in
58 * production). The associated code should also probably be removed
59 * once we're done with experiments.
61 #define ENABLE_HISTOGRAM GNUNET_NO
64 * Over how many values do we calculate the weighted average?
66 #define HISTORY_SIZE 8
69 * Size of the queue to core.
71 #define CORE_QUEUE_SIZE 2
74 * Message priority to use.
76 #define NSE_PRIORITY 5
79 * Amount of work required (W-bit collisions) for NSE proofs, in collision-bits.
81 static unsigned long long nse_work_required;
84 * Interval for sending network size estimation flood requests.
86 static struct GNUNET_TIME_Relative gnunet_nse_interval;
89 * Interval between proof find runs.
91 static struct GNUNET_TIME_Relative proof_find_delay;
95 * Handle for writing when we received messages to disk.
97 static struct GNUNET_BIO_WriteHandle *wh;
102 * Per-peer information.
108 * Pending message for this peer.
110 struct GNUNET_MessageHeader *pending_message;
113 * Core handle for sending messages to this peer.
115 struct GNUNET_CORE_TransmitHandle *th;
118 * What is the identity of the peer?
120 struct GNUNET_PeerIdentity id;
123 * Task scheduled to send message to this peer.
125 GNUNET_SCHEDULER_TaskIdentifier transmit_task;
128 * Did we receive or send a message about the previous round
129 * to this peer yet? GNUNET_YES if the previous round has
130 * been taken care of.
137 * Network size estimate reply; sent when "this"
138 * peer's timer has run out before receiving a
139 * valid reply from another peer.
141 struct GNUNET_NSE_FloodMessage
144 * Type: GNUNET_MESSAGE_TYPE_NSE_P2P_FLOOD
146 struct GNUNET_MessageHeader header;
149 * Number of hops this message has taken so far.
156 struct GNUNET_CRYPTO_RsaSignaturePurpose purpose;
159 * The current timestamp value (which all
160 * peers should agree on).
162 struct GNUNET_TIME_AbsoluteNBO timestamp;
165 * Number of matching bits between the hash
166 * of timestamp and the initiator's public
169 uint32_t matching_bits;
172 * Public key of the originator.
174 struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded pkey;
177 * Proof of work, causing leading zeros when hashed with pkey.
179 uint64_t proof_of_work;
182 * Signature (over range specified in purpose).
184 struct GNUNET_CRYPTO_RsaSignature signature;
189 * Handle to our current configuration.
191 static const struct GNUNET_CONFIGURATION_Handle *cfg;
194 * Handle to the statistics service.
196 static struct GNUNET_STATISTICS_Handle *stats;
199 * Handle to the core service.
201 static struct GNUNET_CORE_Handle *coreAPI;
204 * Map of all connected peers.
206 static struct GNUNET_CONTAINER_MultiHashMap *peers;
209 * The current network size estimate. Number of bits matching on
212 static double current_size_estimate;
215 * The standard deviation of the last HISTORY_SIZE network
218 static double current_std_dev = NAN;
221 * Current hop counter estimate (estimate for network diameter).
223 static uint32_t hop_count_max;
226 * Message for the next round, if we got any.
228 static struct GNUNET_NSE_FloodMessage next_message;
231 * Array of recent size estimate messages.
233 static struct GNUNET_NSE_FloodMessage size_estimate_messages[HISTORY_SIZE];
236 * Index of most recent estimate.
238 static unsigned int estimate_index;
241 * Number of valid entries in the history.
243 static unsigned int estimate_count;
246 * Task scheduled to update our flood message for the next round.
248 static GNUNET_SCHEDULER_TaskIdentifier flood_task;
251 * Task scheduled to compute our proof.
253 static GNUNET_SCHEDULER_TaskIdentifier proof_task;
256 * Notification context, simplifies client broadcasts.
258 static struct GNUNET_SERVER_NotificationContext *nc;
261 * The next major time.
263 static struct GNUNET_TIME_Absolute next_timestamp;
266 * The current major time.
268 static struct GNUNET_TIME_Absolute current_timestamp;
271 * The public key of this peer.
273 static struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded my_public_key;
276 * The private key of this peer.
278 static struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key;
281 * The peer identity of this peer.
283 static struct GNUNET_PeerIdentity my_identity;
286 * Proof of work for this peer.
288 static uint64_t my_proof;
292 * Initialize a message to clients with the current network
295 * @param em message to fill in
298 setup_estimate_message (struct GNUNET_NSE_ClientMessage *em)
312 /* Weighted incremental algorithm for stddev according to West (1979) */
316 for (i = 0; i < estimate_count; i++)
319 htonl (size_estimate_messages
320 [(estimate_index - i +
321 HISTORY_SIZE) % HISTORY_SIZE].matching_bits);
322 weight = 1; /* was: estimate_count + 1 - i; */
324 temp = weight + sumweight;
326 r = q * weight / temp;
327 sum += sumweight * q * r;
331 variance = sum / (sumweight - 1.0);
332 GNUNET_assert (variance >= 0);
333 std_dev = sqrt (variance);
334 current_std_dev = std_dev;
335 current_size_estimate = mean;
337 em->header.size = htons (sizeof (struct GNUNET_NSE_ClientMessage));
338 em->header.type = htons (GNUNET_MESSAGE_TYPE_NSE_ESTIMATE);
339 em->reserved = htonl (0);
340 em->timestamp = GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
341 em->size_estimate = mean - 1.0 / 3.0;
342 em->std_deviation = std_dev;
343 GNUNET_STATISTICS_set (stats, "# nodes in the network (estimate)",
344 (uint64_t) pow (2, mean - 1.0 / 3.0), GNUNET_NO);
349 * Handler for START message from client, triggers an
350 * immediate current network estimate notification.
351 * Also, we remember the client for updates upon future
352 * estimate measurements.
355 * @param client who sent the message
356 * @param message the message received
359 handle_start_message (void *cls, struct GNUNET_SERVER_Client *client,
360 const struct GNUNET_MessageHeader *message)
362 struct GNUNET_NSE_ClientMessage em;
365 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received START message from client\n");
367 GNUNET_SERVER_notification_context_add (nc, client);
368 setup_estimate_message (&em);
369 GNUNET_SERVER_notification_context_unicast (nc, client, &em.header,
371 GNUNET_SERVER_receive_done (client, GNUNET_OK);
376 * How long should we delay a message to go the given number of
379 * @param matching_bits number of matching bits to consider
382 get_matching_bits_delay (uint32_t matching_bits)
384 /* Calculated as: S + f/2 - (f / pi) * (atan(x - p')) */
385 // S is next_timestamp (ignored in return value)
386 // f is frequency (gnunet_nse_interval)
387 // x is matching_bits
388 // p' is current_size_estimate
389 return ((double) gnunet_nse_interval.rel_value / (double) 2.0) -
390 ((gnunet_nse_interval.rel_value / M_PI) *
391 atan (matching_bits - current_size_estimate));
396 * What delay randomization should we apply for a given number of matching bits?
398 * @param matching_bits number of matching bits
399 * @return random delay to apply
401 static struct GNUNET_TIME_Relative
402 get_delay_randomization (uint32_t matching_bits)
404 #if USE_RANDOM_DELAYS
405 struct GNUNET_TIME_Relative ret;
407 if (matching_bits == 0)
408 return GNUNET_TIME_UNIT_ZERO;
410 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
411 (uint32_t) (get_matching_bits_delay
413 1) / (double) (hop_count_max +
417 return GNUNET_TIME_UNIT_ZERO;
423 * Get the number of matching bits that the given timestamp has to the given peer ID.
425 * @param timestamp time to generate key
426 * @param id peer identity to compare with
427 * @return number of matching bits
430 get_matching_bits (struct GNUNET_TIME_Absolute timestamp,
431 const struct GNUNET_PeerIdentity *id)
433 GNUNET_HashCode timestamp_hash;
435 GNUNET_CRYPTO_hash (×tamp.abs_value, sizeof (timestamp.abs_value),
437 return GNUNET_CRYPTO_hash_matching_bits (×tamp_hash, &id->hashPubKey);
442 * Get the transmission delay that should be applied for a
445 * @param round_offset -1 for the previous round (random delay between 0 and 50ms)
446 * 0 for the current round (based on our proximity to time key)
447 * @return delay that should be applied
449 static struct GNUNET_TIME_Relative
450 get_transmit_delay (int round_offset)
452 struct GNUNET_TIME_Relative ret;
453 struct GNUNET_TIME_Absolute tgt;
455 uint32_t matching_bits;
457 switch (round_offset)
460 /* previous round is randomized between 0 and 50 ms */
461 #if USE_RANDOM_DELAYS
462 ret.rel_value = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK, 50);
464 ret = GNUNET_TIME_UNIT_ZERO;
467 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
468 "Transmitting previous round behind schedule in %llu ms\n",
469 (unsigned long long) ret.rel_value);
473 /* current round is based on best-known matching_bits */
475 ntohl (size_estimate_messages[estimate_index].matching_bits);
476 dist_delay = get_matching_bits_delay (matching_bits);
477 dist_delay += get_delay_randomization (matching_bits).rel_value;
478 ret.rel_value = (uint64_t) dist_delay;
480 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
481 "For round %llu, delay for %u matching bits is %llu ms\n",
482 (unsigned long long) current_timestamp.abs_value,
483 (unsigned int) matching_bits,
484 (unsigned long long) ret.rel_value);
486 /* now consider round start time and add delay to it */
487 tgt = GNUNET_TIME_absolute_add (current_timestamp, ret);
488 return GNUNET_TIME_absolute_get_remaining (tgt);
491 return GNUNET_TIME_UNIT_FOREVER_REL;
496 * Task that triggers a NSE P2P transmission.
498 * @param cls the 'struct NSEPeerEntry'
499 * @param tc scheduler context
502 transmit_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
506 * Called when core is ready to send a message we asked for
507 * out to the destination.
509 * @param cls closure (NULL)
510 * @param size number of bytes available in buf
511 * @param buf where the callee should write the message
512 * @return number of bytes written to buf
515 transmit_ready (void *cls, size_t size, void *buf)
517 struct NSEPeerEntry *peer_entry = cls;
520 peer_entry->th = NULL;
523 /* client disconnected */
526 GNUNET_assert (size >= sizeof (struct GNUNET_NSE_FloodMessage));
527 idx = estimate_index;
528 if (peer_entry->previous_round == GNUNET_NO)
530 idx = (idx + HISTORY_SIZE - 1) % HISTORY_SIZE;
531 peer_entry->previous_round = GNUNET_YES;
532 peer_entry->transmit_task =
533 GNUNET_SCHEDULER_add_delayed (get_transmit_delay (0), &transmit_task,
536 if ((ntohl (size_estimate_messages[idx].hop_count) == 0) &&
537 (GNUNET_SCHEDULER_NO_TASK != proof_task))
539 GNUNET_STATISTICS_update (stats,
540 "# flood messages not generated (no proof yet)",
545 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
546 "In round %llu, sending to `%s' estimate with %u bits\n",
548 GNUNET_TIME_absolute_ntoh (size_estimate_messages[idx].
549 timestamp).abs_value,
550 GNUNET_i2s (&peer_entry->id),
551 (unsigned int) ntohl (size_estimate_messages[idx].matching_bits));
553 if (ntohl (size_estimate_messages[idx].hop_count) == 0)
554 GNUNET_STATISTICS_update (stats, "# flood messages started", 1, GNUNET_NO);
555 GNUNET_STATISTICS_update (stats, "# flood messages transmitted", 1,
557 memcpy (buf, &size_estimate_messages[idx],
558 sizeof (struct GNUNET_NSE_FloodMessage));
559 GNUNET_STATISTICS_update (stats, "# flood messages sent", 1, GNUNET_NO);
560 return sizeof (struct GNUNET_NSE_FloodMessage);
565 * Task that triggers a NSE P2P transmission.
567 * @param cls the 'struct NSEPeerEntry'
568 * @param tc scheduler context
571 transmit_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
573 struct NSEPeerEntry *peer_entry = cls;
575 peer_entry->transmit_task = GNUNET_SCHEDULER_NO_TASK;
576 GNUNET_assert (NULL == peer_entry->th);
578 GNUNET_CORE_notify_transmit_ready (coreAPI, GNUNET_NO, NSE_PRIORITY,
579 GNUNET_TIME_UNIT_FOREVER_REL,
582 GNUNET_NSE_FloodMessage),
583 &transmit_ready, peer_entry);
588 * We've sent on our flood message or one that we received which was
589 * validated and closer than ours. Update the global list of recent
590 * messages and the average. Also re-broadcast the message to any
594 update_network_size_estimate ()
596 struct GNUNET_NSE_ClientMessage em;
598 setup_estimate_message (&em);
599 GNUNET_SERVER_notification_context_broadcast (nc, &em.header, GNUNET_YES);
604 * Setup a flood message in our history array at the given
605 * slot offset for the given timestamp.
607 * @param slot index to use
608 * @param ts timestamp to use
611 setup_flood_message (unsigned int slot, struct GNUNET_TIME_Absolute ts)
613 struct GNUNET_NSE_FloodMessage *fm;
614 uint32_t matching_bits;
616 matching_bits = get_matching_bits (ts, &my_identity);
617 fm = &size_estimate_messages[slot];
618 fm->header.size = htons (sizeof (struct GNUNET_NSE_FloodMessage));
619 fm->header.type = htons (GNUNET_MESSAGE_TYPE_NSE_P2P_FLOOD);
620 fm->hop_count = htonl (0);
621 fm->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_NSE_SEND);
623 htonl (sizeof (struct GNUNET_NSE_FloodMessage) -
624 sizeof (struct GNUNET_MessageHeader) - sizeof (uint32_t) -
625 sizeof (struct GNUNET_CRYPTO_RsaSignature));
626 fm->matching_bits = htonl (matching_bits);
627 fm->timestamp = GNUNET_TIME_absolute_hton (ts);
628 fm->pkey = my_public_key;
629 fm->proof_of_work = my_proof;
630 GNUNET_assert (GNUNET_OK ==
631 GNUNET_CRYPTO_rsa_sign (my_private_key, &fm->purpose, &fm->signature));
636 * Schedule transmission for the given peer for the current round based
637 * on what we know about the desired delay.
640 * @param key hash of peer identity
641 * @param value the 'struct NSEPeerEntry'
642 * @return GNUNET_OK (continue to iterate)
645 schedule_current_round (void *cls, const GNUNET_HashCode * key, void *value)
647 struct NSEPeerEntry *peer_entry = value;
648 struct GNUNET_TIME_Relative delay;
650 if (peer_entry->th != NULL)
652 peer_entry->previous_round = GNUNET_NO;
655 if (peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK)
657 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
658 peer_entry->previous_round = GNUNET_NO;
661 get_transmit_delay ((peer_entry->previous_round == GNUNET_NO) ? -1 : 0);
662 peer_entry->transmit_task =
663 GNUNET_SCHEDULER_add_delayed (delay, &transmit_task, peer_entry);
669 * Update our flood message to be sent (and our timestamps).
672 * @param tc context for this message
675 update_flood_message (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
677 struct GNUNET_TIME_Relative offset;
680 flood_task = GNUNET_SCHEDULER_NO_TASK;
681 offset = GNUNET_TIME_absolute_get_remaining (next_timestamp);
682 if (0 != offset.rel_value)
684 /* somehow run early, delay more */
686 GNUNET_SCHEDULER_add_delayed (offset, &update_flood_message, NULL);
689 current_timestamp = next_timestamp;
691 GNUNET_TIME_absolute_add (current_timestamp, gnunet_nse_interval);
692 estimate_index = (estimate_index + 1) % HISTORY_SIZE;
693 if (estimate_count < HISTORY_SIZE)
695 if (next_timestamp.abs_value ==
696 GNUNET_TIME_absolute_ntoh (next_message.timestamp).abs_value)
698 /* we received a message for this round way early, use it! */
699 size_estimate_messages[estimate_index] = next_message;
700 size_estimate_messages[estimate_index].hop_count =
701 htonl (1 + ntohl (next_message.hop_count));
704 setup_flood_message (estimate_index, current_timestamp);
705 next_message.matching_bits = htonl (0); /* reset for 'next' round */
707 for (i = 0; i < HISTORY_SIZE; i++)
709 GNUNET_MAX (ntohl (size_estimate_messages[i].hop_count), hop_count_max);
710 GNUNET_CONTAINER_multihashmap_iterate (peers, &schedule_current_round, NULL);
712 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_absolute_get_remaining
713 (next_timestamp), &update_flood_message,
719 * Count the leading zeroes in hash.
722 * @return the number of leading zero bits.
725 count_leading_zeroes (const GNUNET_HashCode * hash)
727 unsigned int hash_count;
730 while ((0 == GNUNET_CRYPTO_hash_get_bit (hash, hash_count)))
737 * Check whether the given public key
738 * and integer are a valid proof of work.
740 * @param pkey the public key
741 * @param val the integer
743 * @return GNUNET_YES if valid, GNUNET_NO if not
746 check_proof_of_work (const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *pkey,
749 char buf[sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded) +
751 GNUNET_HashCode result;
753 memcpy (buf, &val, sizeof (val));
754 memcpy (&buf[sizeof (val)], pkey,
755 sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded));
756 GNUNET_CRYPTO_hash (buf, sizeof (buf), &result);
757 return (count_leading_zeroes (&result) >=
758 nse_work_required) ? GNUNET_YES : GNUNET_NO;
763 * Write our current proof to disk.
771 GNUNET_CONFIGURATION_get_value_filename (cfg, "NSE", "PROOFFILE", &proof))
773 if (sizeof (my_proof) !=
774 GNUNET_DISK_fn_write (proof, &my_proof, sizeof (my_proof),
775 GNUNET_DISK_PERM_USER_READ |
776 GNUNET_DISK_PERM_USER_WRITE))
777 GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "write", proof);
784 * Find our proof of work.
786 * @param cls closure (unused)
787 * @param tc task context
790 find_proof (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
792 #define ROUND_SIZE 10
794 char buf[sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded) +
796 GNUNET_HashCode result;
799 proof_task = GNUNET_SCHEDULER_NO_TASK;
800 memcpy (&buf[sizeof (uint64_t)], &my_public_key,
801 sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded));
804 while ((counter != UINT64_MAX) && (i < ROUND_SIZE))
806 memcpy (buf, &counter, sizeof (uint64_t));
807 GNUNET_CRYPTO_hash (buf, sizeof (buf), &result);
808 if (nse_work_required <= count_leading_zeroes (&result))
812 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Proof of work found: %llu!\n",
813 (unsigned long long) GNUNET_ntohll (counter));
815 for (i = 0; i < HISTORY_SIZE; i++)
816 if (ntohl (size_estimate_messages[i].hop_count) == 0)
818 size_estimate_messages[i].proof_of_work = my_proof;
819 GNUNET_assert (GNUNET_OK ==
820 GNUNET_CRYPTO_rsa_sign (my_private_key,
821 &size_estimate_messages[i].purpose,
822 &size_estimate_messages[i].signature));
830 if (my_proof / (100 * ROUND_SIZE) < counter / (100 * ROUND_SIZE))
833 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Testing proofs currently at %llu\n",
834 (unsigned long long) counter);
836 /* remember progress every 100 rounds */
845 GNUNET_SCHEDULER_add_delayed (proof_find_delay, &find_proof, NULL);
850 * An incoming flood message has been received which claims
851 * to have more bits matching than any we know in this time
852 * period. Verify the signature and/or proof of work.
854 * @param incoming_flood the message to verify
856 * @return GNUNET_YES if the message is verified
857 * GNUNET_NO if the key/signature don't verify
860 verify_message_crypto (const struct GNUNET_NSE_FloodMessage *incoming_flood)
863 check_proof_of_work (&incoming_flood->pkey,
864 incoming_flood->proof_of_work))
866 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Proof of work invalid: %llu!\n"),
868 GNUNET_ntohll (incoming_flood->proof_of_work));
873 GNUNET_CRYPTO_rsa_verify (GNUNET_SIGNATURE_PURPOSE_NSE_SEND,
874 &incoming_flood->purpose,
875 &incoming_flood->signature,
876 &incoming_flood->pkey))
886 * Update transmissions for the given peer for the current round based
887 * on updated proximity information.
889 * @param cls peer entry to exclude from updates
890 * @param key hash of peer identity
891 * @param value the 'struct NSEPeerEntry'
892 * @return GNUNET_OK (continue to iterate)
895 update_flood_times (void *cls, const GNUNET_HashCode * key, void *value)
897 struct NSEPeerEntry *exclude = cls;
898 struct NSEPeerEntry *peer_entry = value;
899 struct GNUNET_TIME_Relative delay;
901 if (peer_entry->th != NULL)
902 return GNUNET_OK; /* already active */
903 if (peer_entry == exclude)
904 return GNUNET_OK; /* trigger of the update */
905 if (peer_entry->previous_round == GNUNET_NO)
907 /* still stuck in previous round, no point to update, check that
908 * we are active here though... */
909 GNUNET_break ((peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK) ||
910 (peer_entry->th != NULL));
913 if (peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK)
915 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
916 peer_entry->transmit_task = GNUNET_SCHEDULER_NO_TASK;
918 delay = get_transmit_delay (0);
919 peer_entry->transmit_task =
920 GNUNET_SCHEDULER_add_delayed (delay, &transmit_task, peer_entry);
926 * Core handler for size estimate flooding messages.
928 * @param cls closure unused
929 * @param message message
930 * @param peer peer identity this message is from (ignored)
931 * @param atsi performance data (ignored)
935 handle_p2p_size_estimate (void *cls, const struct GNUNET_PeerIdentity *peer,
936 const struct GNUNET_MessageHeader *message,
937 const struct GNUNET_TRANSPORT_ATS_Information *atsi)
939 const struct GNUNET_NSE_FloodMessage *incoming_flood;
940 struct GNUNET_TIME_Absolute ts;
941 struct NSEPeerEntry *peer_entry;
942 uint32_t matching_bits;
947 GNUNET_BIO_write_int64 (wh, GNUNET_TIME_absolute_get ().abs_value);
949 incoming_flood = (const struct GNUNET_NSE_FloodMessage *) message;
950 GNUNET_STATISTICS_update (stats, "# flood messages received", 1, GNUNET_NO);
951 matching_bits = ntohl (incoming_flood->matching_bits);
956 struct GNUNET_PeerIdentity os;
958 GNUNET_CRYPTO_hash (&incoming_flood->pkey,
959 sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
961 GNUNET_snprintf (origin, sizeof (origin), "%s", GNUNET_i2s (&os));
962 GNUNET_snprintf (pred, sizeof (pred), "%s", GNUNET_i2s (peer));
963 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
964 "Flood at %llu from `%s' via `%s' at `%s' with bits %u\n",
966 GNUNET_TIME_absolute_ntoh (incoming_flood->timestamp).abs_value,
967 origin, pred, GNUNET_i2s (&my_identity),
968 (unsigned int) matching_bits);
972 peer_entry = GNUNET_CONTAINER_multihashmap_get (peers, &peer->hashPubKey);
973 if (NULL == peer_entry)
979 ts = GNUNET_TIME_absolute_ntoh (incoming_flood->timestamp);
981 if (ts.abs_value == current_timestamp.abs_value)
982 idx = estimate_index;
983 else if (ts.abs_value ==
984 current_timestamp.abs_value - gnunet_nse_interval.rel_value)
985 idx = (estimate_index + HISTORY_SIZE - 1) % HISTORY_SIZE;
986 else if (ts.abs_value ==
987 next_timestamp.abs_value - gnunet_nse_interval.rel_value)
989 if (matching_bits <= ntohl (next_message.matching_bits))
990 return GNUNET_OK; /* ignore, simply too early/late */
991 if (GNUNET_YES != verify_message_crypto (incoming_flood))
996 next_message = *incoming_flood;
1001 GNUNET_STATISTICS_update (stats,
1002 "# flood messages discarded (clock skew too large)",
1006 if (0 == (memcmp (peer, &my_identity, sizeof (struct GNUNET_PeerIdentity))))
1008 /* send to self, update our own estimate IF this also comes from us! */
1010 memcmp (&incoming_flood->pkey, &my_public_key, sizeof (my_public_key)))
1011 update_network_size_estimate ();
1014 if (matching_bits >= ntohl (size_estimate_messages[idx].matching_bits))
1016 /* cancel transmission from us to this peer for this round */
1017 if (idx == estimate_index)
1019 if (peer_entry->previous_round == GNUNET_YES)
1021 /* cancel any activity for current round */
1022 if (peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK)
1024 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
1025 peer_entry->transmit_task = GNUNET_SCHEDULER_NO_TASK;
1027 if (peer_entry->th != NULL)
1029 GNUNET_CORE_notify_transmit_ready_cancel (peer_entry->th);
1030 peer_entry->th = NULL;
1036 /* cancel previous round only */
1037 peer_entry->previous_round = GNUNET_YES;
1040 if (matching_bits == ntohl (size_estimate_messages[idx].matching_bits))
1042 if (matching_bits <= ntohl (size_estimate_messages[idx].matching_bits))
1044 if ((idx < estimate_index) && (peer_entry->previous_round == GNUNET_YES))
1045 peer_entry->previous_round = GNUNET_NO;
1046 /* push back our result now, that peer is spreading bad information... */
1047 if (NULL == peer_entry->th)
1049 if (peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK)
1050 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
1051 peer_entry->transmit_task =
1052 GNUNET_SCHEDULER_add_now (&transmit_task, peer_entry);
1054 /* Not closer than our most recent message, no need to do work here */
1055 GNUNET_STATISTICS_update (stats,
1056 "# flood messages ignored (had closer already)",
1060 if (GNUNET_YES != verify_message_crypto (incoming_flood))
1062 GNUNET_break_op (0);
1065 size_estimate_messages[idx] = *incoming_flood;
1066 size_estimate_messages[idx].hop_count =
1067 htonl (ntohl (incoming_flood->hop_count) + 1);
1069 GNUNET_MAX (ntohl (incoming_flood->hop_count) + 1, hop_count_max);
1071 /* have a new, better size estimate, inform clients */
1072 update_network_size_estimate ();
1075 GNUNET_CONTAINER_multihashmap_iterate (peers, &update_flood_times,
1083 * Method called whenever a peer connects.
1085 * @param cls closure
1086 * @param peer peer identity this notification is about
1087 * @param atsi performance data
1090 handle_core_connect (void *cls, const struct GNUNET_PeerIdentity *peer,
1091 const struct GNUNET_TRANSPORT_ATS_Information *atsi)
1093 struct NSEPeerEntry *peer_entry;
1096 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Peer `%s' connected to us\n",
1099 peer_entry = GNUNET_malloc (sizeof (struct NSEPeerEntry));
1100 peer_entry->id = *peer;
1101 GNUNET_CONTAINER_multihashmap_put (peers, &peer->hashPubKey, peer_entry,
1102 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
1103 peer_entry->transmit_task =
1104 GNUNET_SCHEDULER_add_delayed (get_transmit_delay (-1), &transmit_task,
1110 * Method called whenever a peer disconnects.
1112 * @param cls closure
1113 * @param peer peer identity this notification is about
1116 handle_core_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer)
1118 struct NSEPeerEntry *pos;
1121 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Peer `%s' disconnected from us\n",
1124 pos = GNUNET_CONTAINER_multihashmap_get (peers, &peer->hashPubKey);
1130 GNUNET_assert (GNUNET_YES ==
1131 GNUNET_CONTAINER_multihashmap_remove (peers, &peer->hashPubKey,
1133 if (pos->transmit_task != GNUNET_SCHEDULER_NO_TASK)
1134 GNUNET_SCHEDULER_cancel (pos->transmit_task);
1135 if (pos->th != NULL)
1137 GNUNET_CORE_notify_transmit_ready_cancel (pos->th);
1145 * Task run during shutdown.
1151 shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1153 if (flood_task != GNUNET_SCHEDULER_NO_TASK)
1155 GNUNET_SCHEDULER_cancel (flood_task);
1156 flood_task = GNUNET_SCHEDULER_NO_TASK;
1158 if (proof_task != GNUNET_SCHEDULER_NO_TASK)
1160 GNUNET_SCHEDULER_cancel (proof_task);
1161 proof_task = GNUNET_SCHEDULER_NO_TASK;
1162 write_proof (); /* remember progress */
1166 GNUNET_SERVER_notification_context_destroy (nc);
1169 if (coreAPI != NULL)
1171 GNUNET_CORE_disconnect (coreAPI);
1176 GNUNET_STATISTICS_destroy (stats, GNUNET_NO);
1181 GNUNET_CONTAINER_multihashmap_destroy (peers);
1184 if (my_private_key != NULL)
1186 GNUNET_CRYPTO_rsa_key_free (my_private_key);
1187 my_private_key = NULL;
1189 #if ENABLE_HISTOGRAM
1192 GNUNET_BIO_write_close (wh);
1200 * Called on core init/fail.
1202 * @param cls service closure
1203 * @param server handle to the server for this service
1204 * @param identity the public identity of this peer
1205 * @param publicKey the public key of this peer
1208 core_init (void *cls, struct GNUNET_CORE_Handle *server,
1209 const struct GNUNET_PeerIdentity *identity,
1210 const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *publicKey)
1212 struct GNUNET_TIME_Absolute now;
1213 struct GNUNET_TIME_Absolute prev_time;
1219 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connection to core FAILED!\n");
1221 GNUNET_SCHEDULER_shutdown ();
1225 memcmp (&my_identity, identity,
1226 sizeof (struct GNUNET_PeerIdentity)));
1227 now = GNUNET_TIME_absolute_get ();
1228 current_timestamp.abs_value =
1229 (now.abs_value / gnunet_nse_interval.rel_value) *
1230 gnunet_nse_interval.rel_value;
1231 next_timestamp.abs_value =
1232 current_timestamp.abs_value + gnunet_nse_interval.rel_value;
1234 for (i = 0; i < HISTORY_SIZE; i++)
1236 prev_time.abs_value =
1237 current_timestamp.abs_value - (HISTORY_SIZE - i -
1238 1) * gnunet_nse_interval.rel_value;
1239 setup_flood_message (i, prev_time);
1241 estimate_index = HISTORY_SIZE - 1;
1244 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_absolute_get_remaining
1245 (next_timestamp), &update_flood_message,
1251 * Handle network size estimate clients.
1253 * @param cls closure
1254 * @param server the initialized server
1255 * @param c configuration to use
1258 run (void *cls, struct GNUNET_SERVER_Handle *server,
1259 const struct GNUNET_CONFIGURATION_Handle *c)
1264 static const struct GNUNET_SERVER_MessageHandler handlers[] = {
1265 {&handle_start_message, NULL, GNUNET_MESSAGE_TYPE_NSE_START,
1266 sizeof (struct GNUNET_MessageHeader)},
1269 static const struct GNUNET_CORE_MessageHandler core_handlers[] = {
1270 {&handle_p2p_size_estimate, GNUNET_MESSAGE_TYPE_NSE_P2P_FLOOD,
1271 sizeof (struct GNUNET_NSE_FloodMessage)},
1277 GNUNET_CONFIGURATION_get_value_time (cfg, "NSE", "INTERVAL",
1278 &gnunet_nse_interval)) ||
1280 GNUNET_CONFIGURATION_get_value_time (cfg, "NSE", "WORKDELAY",
1281 &proof_find_delay)) ||
1283 GNUNET_CONFIGURATION_get_value_number (cfg, "NSE", "WORKBITS",
1284 &nse_work_required)))
1286 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1288 ("NSE service is lacking key configuration settings. Exiting.\n"));
1289 GNUNET_SCHEDULER_shutdown ();
1292 if (nse_work_required >= sizeof (GNUNET_HashCode) * 8)
1294 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1295 _("Invalid work requirement for NSE service. Exiting.\n"));
1296 GNUNET_SCHEDULER_shutdown ();
1302 GNUNET_CONFIGURATION_get_value_filename (cfg, "GNUNETD", "HOSTKEY",
1305 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1307 ("NSE service is lacking key configuration settings. Exiting.\n"));
1308 GNUNET_SCHEDULER_shutdown ();
1311 my_private_key = GNUNET_CRYPTO_rsa_key_create_from_file (keyfile);
1312 GNUNET_free (keyfile);
1313 if (my_private_key == NULL)
1315 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1316 _("NSE service could not access hostkey. Exiting.\n"));
1317 GNUNET_SCHEDULER_shutdown ();
1320 GNUNET_CRYPTO_rsa_key_get_public (my_private_key, &my_public_key);
1321 GNUNET_CRYPTO_hash (&my_public_key, sizeof (my_public_key),
1322 &my_identity.hashPubKey);
1324 GNUNET_CONFIGURATION_get_value_filename (cfg, "NSE", "PROOFFILE", &proof))
1326 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1328 ("NSE service is lacking key configuration settings. Exiting.\n"));
1329 if (my_private_key != NULL)
1331 GNUNET_CRYPTO_rsa_key_free (my_private_key);
1332 my_private_key = NULL;
1334 GNUNET_SCHEDULER_shutdown ();
1337 if ((GNUNET_YES != GNUNET_DISK_file_test (proof)) ||
1338 (sizeof (my_proof) !=
1339 GNUNET_DISK_fn_read (proof, &my_proof, sizeof (my_proof))))
1341 GNUNET_free (proof);
1343 GNUNET_SCHEDULER_add_with_priority (GNUNET_SCHEDULER_PRIORITY_IDLE,
1346 peers = GNUNET_CONTAINER_multihashmap_create (128);
1347 GNUNET_SERVER_add_handlers (server, handlers);
1348 nc = GNUNET_SERVER_notification_context_create (server, 1);
1349 /* Connect to core service and register core handlers */
1350 coreAPI = GNUNET_CORE_connect (cfg, /* Main configuration */
1351 CORE_QUEUE_SIZE, /* queue size */
1352 NULL, /* Closure passed to functions */
1353 &core_init, /* Call core_init once connected */
1354 &handle_core_connect, /* Handle connects */
1355 &handle_core_disconnect, /* Handle disconnects */
1356 NULL, /* Do we care about "status" updates? */
1357 NULL, /* Don't want notified about all incoming messages */
1358 GNUNET_NO, /* For header only inbound notification */
1359 NULL, /* Don't want notified about all outbound messages */
1360 GNUNET_NO, /* For header only outbound notification */
1361 core_handlers); /* Register these handlers */
1362 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &shutdown_task,
1364 #if ENABLE_HISTOGRAM
1366 GNUNET_CONFIGURATION_get_value_filename (cfg, "NSE", "HISTOGRAM", &proof))
1368 wh = GNUNET_BIO_write_open (proof);
1369 GNUNET_free (proof);
1372 if (coreAPI == NULL)
1374 GNUNET_SCHEDULER_shutdown ();
1377 stats = GNUNET_STATISTICS_create ("nse", cfg);
1382 * The main function for the statistics service.
1384 * @param argc number of arguments from the command line
1385 * @param argv command line arguments
1386 * @return 0 ok, 1 on error
1389 main (int argc, char *const *argv)
1391 return (GNUNET_OK ==
1392 GNUNET_SERVICE_run (argc, argv, "nse", GNUNET_SERVICE_OPTION_NONE,
1393 &run, NULL)) ? 0 : 1;
1396 /* end of gnunet-service-nse.c */