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
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.
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.
40 #include "gnunet_util_lib.h"
41 #include "gnunet_constants.h"
42 #include "gnunet_protocols.h"
43 #include "gnunet_signatures.h"
44 #include "gnunet_statistics_service.h"
45 #include "gnunet_core_service.h"
46 #include "gnunet_nse_service.h"
50 * Should messages be delayed randomly? This option should be set to
51 * GNUNET_NO only for experiments, not in production. It should also
52 * be removed once the initial experiments have been completed.
54 #define USE_RANDOM_DELAYS GNUNET_YES
57 * Should we generate a histogram with the time stamps of when we received
58 * NSE messages to disk? (for performance evaluation only, not useful in
59 * production). The associated code should also probably be removed
60 * once we're done with experiments.
62 #define ENABLE_HISTOGRAM GNUNET_NO
65 * Over how many values do we calculate the weighted average?
67 #define HISTORY_SIZE 64
70 * Message priority to use.
72 #define NSE_PRIORITY 5
75 #define log2(a) (log(a)/log(2))
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.
151 uint32_t hop_count GNUNET_PACKED;
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 GNUNET_PACKED;
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 GNUNET_PACKED;
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)
309 /* Weighted incremental algorithm for stddev according to West (1979) */
321 for (i = 0; i < estimate_count; i++)
323 j = (estimate_index - i + HISTORY_SIZE) % HISTORY_SIZE;
324 val = htonl (size_estimate_messages[j].matching_bits);
325 weight = estimate_count + 1 - i;
327 temp = weight + sumweight;
329 r = q * weight / temp;
331 sum += sumweight * q * r;
334 if (estimate_count > 0)
335 variance = (sum / sumweight) * estimate_count / (estimate_count - 1.0);
337 /* trivial version for debugging */
340 /* non-weighted trivial version */
346 for (i = 0; i < estimate_count; i++)
348 j = (estimate_index - i + HISTORY_SIZE) % HISTORY_SIZE;
349 val = htonl (size_estimate_messages[j].matching_bits);
353 if (0 != estimate_count)
355 mean = sum / estimate_count;
356 variance = (vsq - mean * sum) / (estimate_count - 1.0); // terrible for numerical stability...
359 GNUNET_assert (variance >= 0);
360 std_dev = sqrt (variance);
361 current_std_dev = std_dev;
362 current_size_estimate = mean;
364 em->header.size = htons (sizeof (struct GNUNET_NSE_ClientMessage));
365 em->header.type = htons (GNUNET_MESSAGE_TYPE_NSE_ESTIMATE);
366 em->reserved = htonl (0);
367 em->timestamp = GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
368 em->size_estimate = mean - 0.332747;
369 nsize = log2 (GNUNET_CONTAINER_multihashmap_size (peers) + 1);
370 if (em->size_estimate < nsize)
371 em->size_estimate = nsize;
372 em->std_deviation = std_dev;
373 GNUNET_STATISTICS_set (stats, "# nodes in the network (estimate)",
374 (uint64_t) pow (2, mean - 1.0 / 3.0), GNUNET_NO);
379 * Handler for START message from client, triggers an
380 * immediate current network estimate notification.
381 * Also, we remember the client for updates upon future
382 * estimate measurements.
385 * @param client who sent the message
386 * @param message the message received
389 handle_start_message (void *cls, struct GNUNET_SERVER_Client *client,
390 const struct GNUNET_MessageHeader *message)
392 struct GNUNET_NSE_ClientMessage em;
395 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received START message from client\n");
397 GNUNET_SERVER_notification_context_add (nc, client);
398 setup_estimate_message (&em);
399 GNUNET_SERVER_notification_context_unicast (nc, client, &em.header,
401 GNUNET_SERVER_receive_done (client, GNUNET_OK);
406 * How long should we delay a message to go the given number of
409 * @param matching_bits number of matching bits to consider
412 get_matching_bits_delay (uint32_t matching_bits)
414 /* Calculated as: S + f/2 - (f / pi) * (atan(x - p')) */
415 // S is next_timestamp (ignored in return value)
416 // f is frequency (gnunet_nse_interval)
417 // x is matching_bits
418 // p' is current_size_estimate
419 return ((double) gnunet_nse_interval.rel_value / (double) 2.0) -
420 ((gnunet_nse_interval.rel_value / M_PI) *
421 atan (matching_bits - current_size_estimate));
426 * What delay randomization should we apply for a given number of matching bits?
428 * @param matching_bits number of matching bits
429 * @return random delay to apply
431 static struct GNUNET_TIME_Relative
432 get_delay_randomization (uint32_t matching_bits)
434 #if USE_RANDOM_DELAYS
435 struct GNUNET_TIME_Relative ret;
439 if (matching_bits == 0)
440 return GNUNET_TIME_UNIT_ZERO;
441 d = get_matching_bits_delay (matching_bits - 1);
442 i = (uint32_t) (d / (double) (hop_count_max + 1));
443 ret.rel_value = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, i + 1);
446 return GNUNET_TIME_UNIT_ZERO;
452 * Get the number of matching bits that the given timestamp has to the given peer ID.
454 * @param timestamp time to generate key
455 * @param id peer identity to compare with
456 * @return number of matching bits
459 get_matching_bits (struct GNUNET_TIME_Absolute timestamp,
460 const struct GNUNET_PeerIdentity *id)
462 GNUNET_HashCode timestamp_hash;
464 GNUNET_CRYPTO_hash (×tamp.abs_value, sizeof (timestamp.abs_value),
466 return GNUNET_CRYPTO_hash_matching_bits (×tamp_hash, &id->hashPubKey);
471 * Get the transmission delay that should be applied for a
474 * @param round_offset -1 for the previous round (random delay between 0 and 50ms)
475 * 0 for the current round (based on our proximity to time key)
476 * @return delay that should be applied
478 static struct GNUNET_TIME_Relative
479 get_transmit_delay (int round_offset)
481 struct GNUNET_TIME_Relative ret;
482 struct GNUNET_TIME_Absolute tgt;
484 uint32_t matching_bits;
486 switch (round_offset)
489 /* previous round is randomized between 0 and 50 ms */
490 #if USE_RANDOM_DELAYS
491 ret.rel_value = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK, 50);
493 ret = GNUNET_TIME_UNIT_ZERO;
496 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
497 "Transmitting previous round behind schedule in %llu ms\n",
498 (unsigned long long) ret.rel_value);
502 /* current round is based on best-known matching_bits */
504 ntohl (size_estimate_messages[estimate_index].matching_bits);
505 dist_delay = get_matching_bits_delay (matching_bits);
506 dist_delay += get_delay_randomization (matching_bits).rel_value;
507 ret.rel_value = (uint64_t) dist_delay;
509 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
510 "For round %llu, delay for %u matching bits is %llu ms\n",
511 (unsigned long long) current_timestamp.abs_value,
512 (unsigned int) matching_bits,
513 (unsigned long long) ret.rel_value);
515 /* now consider round start time and add delay to it */
516 tgt = GNUNET_TIME_absolute_add (current_timestamp, ret);
517 return GNUNET_TIME_absolute_get_remaining (tgt);
520 return GNUNET_TIME_UNIT_FOREVER_REL;
525 * Task that triggers a NSE P2P transmission.
527 * @param cls the 'struct NSEPeerEntry'
528 * @param tc scheduler context
531 transmit_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
535 * Called when core is ready to send a message we asked for
536 * out to the destination.
538 * @param cls closure (NULL)
539 * @param size number of bytes available in buf
540 * @param buf where the callee should write the message
541 * @return number of bytes written to buf
544 transmit_ready (void *cls, size_t size, void *buf)
546 struct NSEPeerEntry *peer_entry = cls;
549 peer_entry->th = NULL;
552 /* client disconnected */
555 GNUNET_assert (size >= sizeof (struct GNUNET_NSE_FloodMessage));
556 idx = estimate_index;
557 if (peer_entry->previous_round == GNUNET_NO)
559 idx = (idx + HISTORY_SIZE - 1) % HISTORY_SIZE;
560 peer_entry->previous_round = GNUNET_YES;
561 peer_entry->transmit_task =
562 GNUNET_SCHEDULER_add_delayed (get_transmit_delay (0), &transmit_task,
565 if ((ntohl (size_estimate_messages[idx].hop_count) == 0) &&
566 (GNUNET_SCHEDULER_NO_TASK != proof_task))
568 GNUNET_STATISTICS_update (stats,
569 "# flood messages not generated (no proof yet)",
574 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
575 "In round %llu, sending to `%s' estimate with %u bits\n",
577 GNUNET_TIME_absolute_ntoh (size_estimate_messages[idx].
578 timestamp).abs_value,
579 GNUNET_i2s (&peer_entry->id),
580 (unsigned int) ntohl (size_estimate_messages[idx].matching_bits));
582 if (ntohl (size_estimate_messages[idx].hop_count) == 0)
583 GNUNET_STATISTICS_update (stats, "# flood messages started", 1, GNUNET_NO);
584 GNUNET_STATISTICS_update (stats, "# flood messages transmitted", 1,
586 memcpy (buf, &size_estimate_messages[idx],
587 sizeof (struct GNUNET_NSE_FloodMessage));
588 GNUNET_STATISTICS_update (stats, "# flood messages sent", 1, GNUNET_NO);
589 return sizeof (struct GNUNET_NSE_FloodMessage);
594 * Task that triggers a NSE P2P transmission.
596 * @param cls the 'struct NSEPeerEntry'
597 * @param tc scheduler context
600 transmit_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
602 struct NSEPeerEntry *peer_entry = cls;
604 peer_entry->transmit_task = GNUNET_SCHEDULER_NO_TASK;
605 GNUNET_assert (NULL == peer_entry->th);
607 GNUNET_CORE_notify_transmit_ready (coreAPI, GNUNET_NO, NSE_PRIORITY,
608 GNUNET_TIME_UNIT_FOREVER_REL,
611 GNUNET_NSE_FloodMessage),
612 &transmit_ready, peer_entry);
617 * We've sent on our flood message or one that we received which was
618 * validated and closer than ours. Update the global list of recent
619 * messages and the average. Also re-broadcast the message to any
623 update_network_size_estimate ()
625 struct GNUNET_NSE_ClientMessage em;
627 setup_estimate_message (&em);
628 GNUNET_SERVER_notification_context_broadcast (nc, &em.header, GNUNET_YES);
633 * Setup a flood message in our history array at the given
634 * slot offset for the given timestamp.
636 * @param slot index to use
637 * @param ts timestamp to use
640 setup_flood_message (unsigned int slot, struct GNUNET_TIME_Absolute ts)
642 struct GNUNET_NSE_FloodMessage *fm;
643 uint32_t matching_bits;
645 matching_bits = get_matching_bits (ts, &my_identity);
646 fm = &size_estimate_messages[slot];
647 fm->header.size = htons (sizeof (struct GNUNET_NSE_FloodMessage));
648 fm->header.type = htons (GNUNET_MESSAGE_TYPE_NSE_P2P_FLOOD);
649 fm->hop_count = htonl (0);
650 fm->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_NSE_SEND);
652 htonl (sizeof (struct GNUNET_NSE_FloodMessage) -
653 sizeof (struct GNUNET_MessageHeader) - sizeof (uint32_t) -
654 sizeof (struct GNUNET_CRYPTO_RsaSignature));
655 fm->matching_bits = htonl (matching_bits);
656 fm->timestamp = GNUNET_TIME_absolute_hton (ts);
657 fm->pkey = my_public_key;
658 fm->proof_of_work = my_proof;
659 if (nse_work_required > 0)
660 GNUNET_assert (GNUNET_OK ==
661 GNUNET_CRYPTO_rsa_sign (my_private_key, &fm->purpose,
664 memset (&fm->signature, 0, sizeof (fm->signature));
669 * Schedule transmission for the given peer for the current round based
670 * on what we know about the desired delay.
673 * @param key hash of peer identity
674 * @param value the 'struct NSEPeerEntry'
675 * @return GNUNET_OK (continue to iterate)
678 schedule_current_round (void *cls, const GNUNET_HashCode * key, void *value)
680 struct NSEPeerEntry *peer_entry = value;
681 struct GNUNET_TIME_Relative delay;
683 if (peer_entry->th != NULL)
685 peer_entry->previous_round = GNUNET_NO;
688 if (peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK)
690 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
691 peer_entry->previous_round = GNUNET_NO;
694 get_transmit_delay ((peer_entry->previous_round == GNUNET_NO) ? -1 : 0);
695 peer_entry->transmit_task =
696 GNUNET_SCHEDULER_add_delayed (delay, &transmit_task, peer_entry);
702 * Update our flood message to be sent (and our timestamps).
705 * @param tc context for this message
708 update_flood_message (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
710 struct GNUNET_TIME_Relative offset;
713 flood_task = GNUNET_SCHEDULER_NO_TASK;
714 offset = GNUNET_TIME_absolute_get_remaining (next_timestamp);
715 if (0 != offset.rel_value)
717 /* somehow run early, delay more */
719 GNUNET_SCHEDULER_add_delayed (offset, &update_flood_message, NULL);
722 current_timestamp = next_timestamp;
724 GNUNET_TIME_absolute_add (current_timestamp, gnunet_nse_interval);
725 estimate_index = (estimate_index + 1) % HISTORY_SIZE;
726 if (estimate_count < HISTORY_SIZE)
728 if (next_timestamp.abs_value ==
729 GNUNET_TIME_absolute_ntoh (next_message.timestamp).abs_value)
731 /* we received a message for this round way early, use it! */
732 size_estimate_messages[estimate_index] = next_message;
733 size_estimate_messages[estimate_index].hop_count =
734 htonl (1 + ntohl (next_message.hop_count));
737 setup_flood_message (estimate_index, current_timestamp);
738 next_message.matching_bits = htonl (0); /* reset for 'next' round */
740 for (i = 0; i < HISTORY_SIZE; i++)
742 GNUNET_MAX (ntohl (size_estimate_messages[i].hop_count), hop_count_max);
743 GNUNET_CONTAINER_multihashmap_iterate (peers, &schedule_current_round, NULL);
745 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_absolute_get_remaining
746 (next_timestamp), &update_flood_message,
752 * Count the leading zeroes in hash.
755 * @return the number of leading zero bits.
758 count_leading_zeroes (const GNUNET_HashCode * hash)
760 unsigned int hash_count;
763 while ((0 == GNUNET_CRYPTO_hash_get_bit (hash, hash_count)))
770 * Check whether the given public key
771 * and integer are a valid proof of work.
773 * @param pkey the public key
774 * @param val the integer
776 * @return GNUNET_YES if valid, GNUNET_NO if not
779 check_proof_of_work (const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *pkey,
782 char buf[sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded) +
784 GNUNET_HashCode result;
786 memcpy (buf, &val, sizeof (val));
787 memcpy (&buf[sizeof (val)], pkey,
788 sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded));
789 GNUNET_CRYPTO_hash (buf, sizeof (buf), &result);
790 return (count_leading_zeroes (&result) >=
791 nse_work_required) ? GNUNET_YES : GNUNET_NO;
796 * Write our current proof to disk.
804 GNUNET_CONFIGURATION_get_value_filename (cfg, "NSE", "PROOFFILE", &proof))
806 if (sizeof (my_proof) !=
807 GNUNET_DISK_fn_write (proof, &my_proof, sizeof (my_proof),
808 GNUNET_DISK_PERM_USER_READ |
809 GNUNET_DISK_PERM_USER_WRITE))
810 GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "write", proof);
817 * Find our proof of work.
819 * @param cls closure (unused)
820 * @param tc task context
823 find_proof (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
825 #define ROUND_SIZE 10
827 char buf[sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded) +
829 GNUNET_HashCode result;
832 proof_task = GNUNET_SCHEDULER_NO_TASK;
833 memcpy (&buf[sizeof (uint64_t)], &my_public_key,
834 sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded));
837 while ((counter != UINT64_MAX) && (i < ROUND_SIZE))
839 memcpy (buf, &counter, sizeof (uint64_t));
840 GNUNET_CRYPTO_hash (buf, sizeof (buf), &result);
841 if (nse_work_required <= count_leading_zeroes (&result))
845 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Proof of work found: %llu!\n",
846 (unsigned long long) GNUNET_ntohll (counter));
848 for (i = 0; i < HISTORY_SIZE; i++)
849 if (ntohl (size_estimate_messages[i].hop_count) == 0)
851 size_estimate_messages[i].proof_of_work = my_proof;
852 if (nse_work_required > 0)
853 GNUNET_assert (GNUNET_OK ==
854 GNUNET_CRYPTO_rsa_sign (my_private_key,
855 &size_estimate_messages
857 &size_estimate_messages
860 memset (&size_estimate_messages[i].signature, 0, sizeof (struct GNUNET_CRYPTO_RsaSignature));
868 if (my_proof / (100 * ROUND_SIZE) < counter / (100 * ROUND_SIZE))
871 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Testing proofs currently at %llu\n",
872 (unsigned long long) counter);
874 /* remember progress every 100 rounds */
883 GNUNET_SCHEDULER_add_delayed (proof_find_delay, &find_proof, NULL);
888 * An incoming flood message has been received which claims
889 * to have more bits matching than any we know in this time
890 * period. Verify the signature and/or proof of work.
892 * @param incoming_flood the message to verify
894 * @return GNUNET_YES if the message is verified
895 * GNUNET_NO if the key/signature don't verify
898 verify_message_crypto (const struct GNUNET_NSE_FloodMessage *incoming_flood)
901 check_proof_of_work (&incoming_flood->pkey,
902 incoming_flood->proof_of_work))
904 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Proof of work invalid: %llu!\n"),
906 GNUNET_ntohll (incoming_flood->proof_of_work));
910 if ( (nse_work_required > 0) &&
912 GNUNET_CRYPTO_rsa_verify (GNUNET_SIGNATURE_PURPOSE_NSE_SEND,
913 &incoming_flood->purpose,
914 &incoming_flood->signature,
915 &incoming_flood->pkey)) )
925 * Update transmissions for the given peer for the current round based
926 * on updated proximity information.
928 * @param cls peer entry to exclude from updates
929 * @param key hash of peer identity
930 * @param value the 'struct NSEPeerEntry'
931 * @return GNUNET_OK (continue to iterate)
934 update_flood_times (void *cls, const GNUNET_HashCode * key, void *value)
936 struct NSEPeerEntry *exclude = cls;
937 struct NSEPeerEntry *peer_entry = value;
938 struct GNUNET_TIME_Relative delay;
940 if (peer_entry->th != NULL)
941 return GNUNET_OK; /* already active */
942 if (peer_entry == exclude)
943 return GNUNET_OK; /* trigger of the update */
944 if (peer_entry->previous_round == GNUNET_NO)
946 /* still stuck in previous round, no point to update, check that
947 * we are active here though... */
948 GNUNET_break ((peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK) ||
949 (peer_entry->th != NULL));
952 if (peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK)
954 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
955 peer_entry->transmit_task = GNUNET_SCHEDULER_NO_TASK;
957 delay = get_transmit_delay (0);
958 peer_entry->transmit_task =
959 GNUNET_SCHEDULER_add_delayed (delay, &transmit_task, peer_entry);
965 * Core handler for size estimate flooding messages.
967 * @param cls closure unused
968 * @param message message
969 * @param peer peer identity this message is from (ignored)
970 * @param atsi performance data (ignored)
971 * @param atsi_count number of records in 'atsi'
974 handle_p2p_size_estimate (void *cls, const struct GNUNET_PeerIdentity *peer,
975 const struct GNUNET_MessageHeader *message,
976 const struct GNUNET_ATS_Information *atsi,
977 unsigned int atsi_count)
979 const struct GNUNET_NSE_FloodMessage *incoming_flood;
980 struct GNUNET_TIME_Absolute ts;
981 struct NSEPeerEntry *peer_entry;
982 uint32_t matching_bits;
987 GNUNET_BIO_write_int64 (wh, GNUNET_TIME_absolute_get ().abs_value);
989 incoming_flood = (const struct GNUNET_NSE_FloodMessage *) message;
990 GNUNET_STATISTICS_update (stats, "# flood messages received", 1, GNUNET_NO);
991 matching_bits = ntohl (incoming_flood->matching_bits);
996 struct GNUNET_PeerIdentity os;
998 GNUNET_CRYPTO_hash (&incoming_flood->pkey,
999 sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
1001 GNUNET_snprintf (origin, sizeof (origin), "%s", GNUNET_i2s (&os));
1002 GNUNET_snprintf (pred, sizeof (pred), "%s", GNUNET_i2s (peer));
1003 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1004 "Flood at %llu from `%s' via `%s' at `%s' with bits %u\n",
1005 (unsigned long long)
1006 GNUNET_TIME_absolute_ntoh (incoming_flood->timestamp).abs_value,
1007 origin, pred, GNUNET_i2s (&my_identity),
1008 (unsigned int) matching_bits);
1012 peer_entry = GNUNET_CONTAINER_multihashmap_get (peers, &peer->hashPubKey);
1013 if (NULL == peer_entry)
1019 ts = GNUNET_TIME_absolute_ntoh (incoming_flood->timestamp);
1021 if (ts.abs_value == current_timestamp.abs_value)
1022 idx = estimate_index;
1023 else if (ts.abs_value ==
1024 current_timestamp.abs_value - gnunet_nse_interval.rel_value)
1025 idx = (estimate_index + HISTORY_SIZE - 1) % HISTORY_SIZE;
1026 else if (ts.abs_value ==
1027 next_timestamp.abs_value - gnunet_nse_interval.rel_value)
1029 if (matching_bits <= ntohl (next_message.matching_bits))
1030 return GNUNET_OK; /* ignore, simply too early/late */
1031 if (GNUNET_YES != verify_message_crypto (incoming_flood))
1033 GNUNET_break_op (0);
1036 next_message = *incoming_flood;
1041 GNUNET_STATISTICS_update (stats,
1042 "# flood messages discarded (clock skew too large)",
1046 if (0 == (memcmp (peer, &my_identity, sizeof (struct GNUNET_PeerIdentity))))
1048 /* send to self, update our own estimate IF this also comes from us! */
1050 memcmp (&incoming_flood->pkey, &my_public_key, sizeof (my_public_key)))
1051 update_network_size_estimate ();
1054 if (matching_bits >= ntohl (size_estimate_messages[idx].matching_bits))
1056 /* cancel transmission from us to this peer for this round */
1057 if (idx == estimate_index)
1059 if (peer_entry->previous_round == GNUNET_YES)
1061 /* cancel any activity for current round */
1062 if (peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK)
1064 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
1065 peer_entry->transmit_task = GNUNET_SCHEDULER_NO_TASK;
1067 if (peer_entry->th != NULL)
1069 GNUNET_CORE_notify_transmit_ready_cancel (peer_entry->th);
1070 peer_entry->th = NULL;
1076 /* cancel previous round only */
1077 peer_entry->previous_round = GNUNET_YES;
1080 if (matching_bits == ntohl (size_estimate_messages[idx].matching_bits))
1082 if (matching_bits <= ntohl (size_estimate_messages[idx].matching_bits))
1084 if ((idx < estimate_index) && (peer_entry->previous_round == GNUNET_YES))
1085 peer_entry->previous_round = GNUNET_NO;
1086 /* push back our result now, that peer is spreading bad information... */
1087 if (NULL == peer_entry->th)
1089 if (peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK)
1090 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
1091 peer_entry->transmit_task =
1092 GNUNET_SCHEDULER_add_now (&transmit_task, peer_entry);
1094 /* Not closer than our most recent message, no need to do work here */
1095 GNUNET_STATISTICS_update (stats,
1096 "# flood messages ignored (had closer already)",
1100 if (GNUNET_YES != verify_message_crypto (incoming_flood))
1102 GNUNET_break_op (0);
1105 size_estimate_messages[idx] = *incoming_flood;
1106 size_estimate_messages[idx].hop_count =
1107 htonl (ntohl (incoming_flood->hop_count) + 1);
1109 GNUNET_MAX (ntohl (incoming_flood->hop_count) + 1, hop_count_max);
1111 /* have a new, better size estimate, inform clients */
1112 update_network_size_estimate ();
1115 GNUNET_CONTAINER_multihashmap_iterate (peers, &update_flood_times,
1123 * Method called whenever a peer connects.
1125 * @param cls closure
1126 * @param peer peer identity this notification is about
1127 * @param atsi performance data
1128 * @param atsi_count number of records in 'atsi'
1131 handle_core_connect (void *cls, const struct GNUNET_PeerIdentity *peer,
1132 const struct GNUNET_ATS_Information *atsi,
1133 unsigned int atsi_count)
1135 struct NSEPeerEntry *peer_entry;
1138 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Peer `%s' connected to us\n",
1141 peer_entry = GNUNET_malloc (sizeof (struct NSEPeerEntry));
1142 peer_entry->id = *peer;
1143 GNUNET_assert (GNUNET_OK ==
1144 GNUNET_CONTAINER_multihashmap_put (peers, &peer->hashPubKey, peer_entry,
1145 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
1146 peer_entry->transmit_task =
1147 GNUNET_SCHEDULER_add_delayed (get_transmit_delay (-1), &transmit_task,
1153 * Method called whenever a peer disconnects.
1155 * @param cls closure
1156 * @param peer peer identity this notification is about
1159 handle_core_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer)
1161 struct NSEPeerEntry *pos;
1164 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Peer `%s' disconnected from us\n",
1167 pos = GNUNET_CONTAINER_multihashmap_get (peers, &peer->hashPubKey);
1173 GNUNET_assert (GNUNET_YES ==
1174 GNUNET_CONTAINER_multihashmap_remove (peers, &peer->hashPubKey,
1176 if (pos->transmit_task != GNUNET_SCHEDULER_NO_TASK)
1177 GNUNET_SCHEDULER_cancel (pos->transmit_task);
1178 if (pos->th != NULL)
1180 GNUNET_CORE_notify_transmit_ready_cancel (pos->th);
1188 * Task run during shutdown.
1194 shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1196 if (flood_task != GNUNET_SCHEDULER_NO_TASK)
1198 GNUNET_SCHEDULER_cancel (flood_task);
1199 flood_task = GNUNET_SCHEDULER_NO_TASK;
1201 if (proof_task != GNUNET_SCHEDULER_NO_TASK)
1203 GNUNET_SCHEDULER_cancel (proof_task);
1204 proof_task = GNUNET_SCHEDULER_NO_TASK;
1205 write_proof (); /* remember progress */
1209 GNUNET_SERVER_notification_context_destroy (nc);
1212 if (coreAPI != NULL)
1214 GNUNET_CORE_disconnect (coreAPI);
1219 GNUNET_STATISTICS_destroy (stats, GNUNET_NO);
1224 GNUNET_CONTAINER_multihashmap_destroy (peers);
1227 if (my_private_key != NULL)
1229 GNUNET_CRYPTO_rsa_key_free (my_private_key);
1230 my_private_key = NULL;
1232 #if ENABLE_HISTOGRAM
1235 GNUNET_BIO_write_close (wh);
1243 * Called on core init/fail.
1245 * @param cls service closure
1246 * @param server handle to the server for this service
1247 * @param identity the public identity of this peer
1250 core_init (void *cls, struct GNUNET_CORE_Handle *server,
1251 const struct GNUNET_PeerIdentity *identity)
1253 struct GNUNET_TIME_Absolute now;
1254 struct GNUNET_TIME_Absolute prev_time;
1260 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connection to core FAILED!\n");
1262 GNUNET_SCHEDULER_shutdown ();
1266 memcmp (&my_identity, identity,
1267 sizeof (struct GNUNET_PeerIdentity)));
1268 now = GNUNET_TIME_absolute_get ();
1269 current_timestamp.abs_value =
1270 (now.abs_value / gnunet_nse_interval.rel_value) *
1271 gnunet_nse_interval.rel_value;
1272 next_timestamp.abs_value =
1273 current_timestamp.abs_value + gnunet_nse_interval.rel_value;
1275 for (i = 0; i < HISTORY_SIZE; i++)
1277 prev_time.abs_value =
1278 current_timestamp.abs_value - (HISTORY_SIZE - i -
1279 1) * gnunet_nse_interval.rel_value;
1280 setup_flood_message (i, prev_time);
1282 estimate_index = HISTORY_SIZE - 1;
1285 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_absolute_get_remaining
1286 (next_timestamp), &update_flood_message,
1292 * Handle network size estimate clients.
1294 * @param cls closure
1295 * @param server the initialized server
1296 * @param c configuration to use
1299 run (void *cls, struct GNUNET_SERVER_Handle *server,
1300 const struct GNUNET_CONFIGURATION_Handle *c)
1305 static const struct GNUNET_SERVER_MessageHandler handlers[] = {
1306 {&handle_start_message, NULL, GNUNET_MESSAGE_TYPE_NSE_START,
1307 sizeof (struct GNUNET_MessageHeader)},
1310 static const struct GNUNET_CORE_MessageHandler core_handlers[] = {
1311 {&handle_p2p_size_estimate, GNUNET_MESSAGE_TYPE_NSE_P2P_FLOOD,
1312 sizeof (struct GNUNET_NSE_FloodMessage)},
1318 GNUNET_CONFIGURATION_get_value_time (cfg, "NSE", "INTERVAL",
1319 &gnunet_nse_interval)) ||
1321 GNUNET_CONFIGURATION_get_value_time (cfg, "NSE", "WORKDELAY",
1322 &proof_find_delay)) ||
1324 GNUNET_CONFIGURATION_get_value_number (cfg, "NSE", "WORKBITS",
1325 &nse_work_required)))
1327 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1329 ("NSE service is lacking key configuration settings. Exiting.\n"));
1330 GNUNET_SCHEDULER_shutdown ();
1333 if (nse_work_required >= sizeof (GNUNET_HashCode) * 8)
1335 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1336 _("Invalid work requirement for NSE service. Exiting.\n"));
1337 GNUNET_SCHEDULER_shutdown ();
1343 GNUNET_CONFIGURATION_get_value_filename (cfg, "GNUNETD", "HOSTKEY",
1346 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1348 ("NSE service is lacking key configuration settings. Exiting.\n"));
1349 GNUNET_SCHEDULER_shutdown ();
1352 my_private_key = GNUNET_CRYPTO_rsa_key_create_from_file (keyfile);
1353 GNUNET_free (keyfile);
1354 if (my_private_key == NULL)
1356 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1357 _("NSE service could not access hostkey. Exiting.\n"));
1358 GNUNET_SCHEDULER_shutdown ();
1361 GNUNET_CRYPTO_rsa_key_get_public (my_private_key, &my_public_key);
1362 GNUNET_CRYPTO_hash (&my_public_key, sizeof (my_public_key),
1363 &my_identity.hashPubKey);
1365 GNUNET_CONFIGURATION_get_value_filename (cfg, "NSE", "PROOFFILE", &proof))
1367 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1369 ("NSE service is lacking key configuration settings. Exiting.\n"));
1370 if (my_private_key != NULL)
1372 GNUNET_CRYPTO_rsa_key_free (my_private_key);
1373 my_private_key = NULL;
1375 GNUNET_SCHEDULER_shutdown ();
1378 if ((GNUNET_YES != GNUNET_DISK_file_test (proof)) ||
1379 (sizeof (my_proof) !=
1380 GNUNET_DISK_fn_read (proof, &my_proof, sizeof (my_proof))))
1382 GNUNET_free (proof);
1384 GNUNET_SCHEDULER_add_with_priority (GNUNET_SCHEDULER_PRIORITY_IDLE,
1387 peers = GNUNET_CONTAINER_multihashmap_create (128);
1388 GNUNET_SERVER_add_handlers (server, handlers);
1389 nc = GNUNET_SERVER_notification_context_create (server, 1);
1390 /* Connect to core service and register core handlers */
1391 coreAPI = GNUNET_CORE_connect (cfg, /* Main configuration */
1393 NULL, /* Closure passed to functions */
1394 &core_init, /* Call core_init once connected */
1395 &handle_core_connect, /* Handle connects */
1396 &handle_core_disconnect, /* Handle disconnects */
1397 NULL, /* Don't want notified about all incoming messages */
1398 GNUNET_NO, /* For header only inbound notification */
1399 NULL, /* Don't want notified about all outbound messages */
1400 GNUNET_NO, /* For header only outbound notification */
1401 core_handlers); /* Register these handlers */
1402 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &shutdown_task,
1404 #if ENABLE_HISTOGRAM
1406 GNUNET_CONFIGURATION_get_value_filename (cfg, "NSE", "HISTOGRAM", &proof))
1408 wh = GNUNET_BIO_write_open (proof);
1409 GNUNET_free (proof);
1412 if (coreAPI == NULL)
1414 GNUNET_SCHEDULER_shutdown ();
1417 stats = GNUNET_STATISTICS_create ("nse", cfg);
1422 * The main function for the statistics service.
1424 * @param argc number of arguments from the command line
1425 * @param argv command line arguments
1426 * @return 0 ok, 1 on error
1429 main (int argc, char *const *argv)
1431 return (GNUNET_OK ==
1432 GNUNET_SERVICE_run (argc, argv, "nse", GNUNET_SERVICE_OPTION_NONE,
1433 &run, NULL)) ? 0 : 1;
1436 /* end of gnunet-service-nse.c */