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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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 8
70 * Size of the queue to core.
72 #define CORE_QUEUE_SIZE 2
75 * Message priority to use.
77 #define NSE_PRIORITY 5
80 * Amount of work required (W-bit collisions) for NSE proofs, in collision-bits.
82 static unsigned long long nse_work_required;
85 * Interval for sending network size estimation flood requests.
87 static struct GNUNET_TIME_Relative gnunet_nse_interval;
90 * Interval between proof find runs.
92 static struct GNUNET_TIME_Relative proof_find_delay;
96 * Handle for writing when we received messages to disk.
98 static struct GNUNET_BIO_WriteHandle *wh;
103 * Per-peer information.
109 * Pending message for this peer.
111 struct GNUNET_MessageHeader *pending_message;
114 * Core handle for sending messages to this peer.
116 struct GNUNET_CORE_TransmitHandle *th;
119 * What is the identity of the peer?
121 struct GNUNET_PeerIdentity id;
124 * Task scheduled to send message to this peer.
126 GNUNET_SCHEDULER_TaskIdentifier transmit_task;
129 * Did we receive or send a message about the previous round
130 * to this peer yet? GNUNET_YES if the previous round has
131 * been taken care of.
138 * Network size estimate reply; sent when "this"
139 * peer's timer has run out before receiving a
140 * valid reply from another peer.
142 struct GNUNET_NSE_FloodMessage
145 * Type: GNUNET_MESSAGE_TYPE_NSE_P2P_FLOOD
147 struct GNUNET_MessageHeader header;
150 * Number of hops this message has taken so far.
152 uint32_t hop_count GNUNET_PACKED;
157 struct GNUNET_CRYPTO_RsaSignaturePurpose purpose;
160 * The current timestamp value (which all
161 * peers should agree on).
163 struct GNUNET_TIME_AbsoluteNBO timestamp;
166 * Number of matching bits between the hash
167 * of timestamp and the initiator's public
170 uint32_t matching_bits GNUNET_PACKED;
173 * Public key of the originator.
175 struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded pkey;
178 * Proof of work, causing leading zeros when hashed with pkey.
180 uint64_t proof_of_work GNUNET_PACKED;
183 * Signature (over range specified in purpose).
185 struct GNUNET_CRYPTO_RsaSignature signature;
190 * Handle to our current configuration.
192 static const struct GNUNET_CONFIGURATION_Handle *cfg;
195 * Handle to the statistics service.
197 static struct GNUNET_STATISTICS_Handle *stats;
200 * Handle to the core service.
202 static struct GNUNET_CORE_Handle *coreAPI;
205 * Map of all connected peers.
207 static struct GNUNET_CONTAINER_MultiHashMap *peers;
210 * The current network size estimate. Number of bits matching on
213 static double current_size_estimate;
216 * The standard deviation of the last HISTORY_SIZE network
219 static double current_std_dev = NAN;
222 * Current hop counter estimate (estimate for network diameter).
224 static uint32_t hop_count_max;
227 * Message for the next round, if we got any.
229 static struct GNUNET_NSE_FloodMessage next_message;
232 * Array of recent size estimate messages.
234 static struct GNUNET_NSE_FloodMessage size_estimate_messages[HISTORY_SIZE];
237 * Index of most recent estimate.
239 static unsigned int estimate_index;
242 * Number of valid entries in the history.
244 static unsigned int estimate_count;
247 * Task scheduled to update our flood message for the next round.
249 static GNUNET_SCHEDULER_TaskIdentifier flood_task;
252 * Task scheduled to compute our proof.
254 static GNUNET_SCHEDULER_TaskIdentifier proof_task;
257 * Notification context, simplifies client broadcasts.
259 static struct GNUNET_SERVER_NotificationContext *nc;
262 * The next major time.
264 static struct GNUNET_TIME_Absolute next_timestamp;
267 * The current major time.
269 static struct GNUNET_TIME_Absolute current_timestamp;
272 * The public key of this peer.
274 static struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded my_public_key;
277 * The private key of this peer.
279 static struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key;
282 * The peer identity of this peer.
284 static struct GNUNET_PeerIdentity my_identity;
287 * Proof of work for this peer.
289 static uint64_t my_proof;
293 * Initialize a message to clients with the current network
296 * @param em message to fill in
299 setup_estimate_message (struct GNUNET_NSE_ClientMessage *em)
314 /* Weighted incremental algorithm for stddev according to West (1979) */
318 for (i = 0; i < estimate_count; i++)
321 htonl (size_estimate_messages
322 [(estimate_index - i +
323 HISTORY_SIZE) % HISTORY_SIZE].matching_bits);
324 weight = 1; /* was: estimate_count + 1 - i; */
326 temp = weight + sumweight;
328 r = q * weight / temp;
329 sum += sumweight * q * r;
333 variance = sum / (sumweight - 1.0);
334 GNUNET_assert (variance >= 0);
335 std_dev = sqrt (variance);
336 current_std_dev = std_dev;
337 current_size_estimate = mean;
339 em->header.size = htons (sizeof (struct GNUNET_NSE_ClientMessage));
340 em->header.type = htons (GNUNET_MESSAGE_TYPE_NSE_ESTIMATE);
341 em->reserved = htonl (0);
342 em->timestamp = GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
343 em->size_estimate = mean - 0.332747;
344 nsize = log2 (GNUNET_CONTAINER_multihashmap_size (peers) + 1);
345 if (em->size_estimate < nsize)
346 em->size_estimate = nsize;
347 em->std_deviation = std_dev;
348 GNUNET_STATISTICS_set (stats, "# nodes in the network (estimate)",
349 (uint64_t) pow (2, mean - 1.0 / 3.0), GNUNET_NO);
354 * Handler for START message from client, triggers an
355 * immediate current network estimate notification.
356 * Also, we remember the client for updates upon future
357 * estimate measurements.
360 * @param client who sent the message
361 * @param message the message received
364 handle_start_message (void *cls, struct GNUNET_SERVER_Client *client,
365 const struct GNUNET_MessageHeader *message)
367 struct GNUNET_NSE_ClientMessage em;
370 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received START message from client\n");
372 GNUNET_SERVER_notification_context_add (nc, client);
373 setup_estimate_message (&em);
374 GNUNET_SERVER_notification_context_unicast (nc, client, &em.header,
376 GNUNET_SERVER_receive_done (client, GNUNET_OK);
381 * How long should we delay a message to go the given number of
384 * @param matching_bits number of matching bits to consider
387 get_matching_bits_delay (uint32_t matching_bits)
389 /* Calculated as: S + f/2 - (f / pi) * (atan(x - p')) */
390 // S is next_timestamp (ignored in return value)
391 // f is frequency (gnunet_nse_interval)
392 // x is matching_bits
393 // p' is current_size_estimate
394 return ((double) gnunet_nse_interval.rel_value / (double) 2.0) -
395 ((gnunet_nse_interval.rel_value / M_PI) *
396 atan (matching_bits - current_size_estimate));
401 * What delay randomization should we apply for a given number of matching bits?
403 * @param matching_bits number of matching bits
404 * @return random delay to apply
406 static struct GNUNET_TIME_Relative
407 get_delay_randomization (uint32_t matching_bits)
409 #if USE_RANDOM_DELAYS
410 struct GNUNET_TIME_Relative ret;
412 if (matching_bits == 0)
413 return GNUNET_TIME_UNIT_ZERO;
415 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
416 (uint32_t) (get_matching_bits_delay
418 1) / (double) (hop_count_max +
422 return GNUNET_TIME_UNIT_ZERO;
428 * Get the number of matching bits that the given timestamp has to the given peer ID.
430 * @param timestamp time to generate key
431 * @param id peer identity to compare with
432 * @return number of matching bits
435 get_matching_bits (struct GNUNET_TIME_Absolute timestamp,
436 const struct GNUNET_PeerIdentity *id)
438 GNUNET_HashCode timestamp_hash;
440 GNUNET_CRYPTO_hash (×tamp.abs_value, sizeof (timestamp.abs_value),
442 return GNUNET_CRYPTO_hash_matching_bits (×tamp_hash, &id->hashPubKey);
447 * Get the transmission delay that should be applied for a
450 * @param round_offset -1 for the previous round (random delay between 0 and 50ms)
451 * 0 for the current round (based on our proximity to time key)
452 * @return delay that should be applied
454 static struct GNUNET_TIME_Relative
455 get_transmit_delay (int round_offset)
457 struct GNUNET_TIME_Relative ret;
458 struct GNUNET_TIME_Absolute tgt;
460 uint32_t matching_bits;
462 switch (round_offset)
465 /* previous round is randomized between 0 and 50 ms */
466 #if USE_RANDOM_DELAYS
467 ret.rel_value = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK, 50);
469 ret = GNUNET_TIME_UNIT_ZERO;
472 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
473 "Transmitting previous round behind schedule in %llu ms\n",
474 (unsigned long long) ret.rel_value);
478 /* current round is based on best-known matching_bits */
480 ntohl (size_estimate_messages[estimate_index].matching_bits);
481 dist_delay = get_matching_bits_delay (matching_bits);
482 dist_delay += get_delay_randomization (matching_bits).rel_value;
483 ret.rel_value = (uint64_t) dist_delay;
485 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
486 "For round %llu, delay for %u matching bits is %llu ms\n",
487 (unsigned long long) current_timestamp.abs_value,
488 (unsigned int) matching_bits,
489 (unsigned long long) ret.rel_value);
491 /* now consider round start time and add delay to it */
492 tgt = GNUNET_TIME_absolute_add (current_timestamp, ret);
493 return GNUNET_TIME_absolute_get_remaining (tgt);
496 return GNUNET_TIME_UNIT_FOREVER_REL;
501 * Task that triggers a NSE P2P transmission.
503 * @param cls the 'struct NSEPeerEntry'
504 * @param tc scheduler context
507 transmit_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
511 * Called when core is ready to send a message we asked for
512 * out to the destination.
514 * @param cls closure (NULL)
515 * @param size number of bytes available in buf
516 * @param buf where the callee should write the message
517 * @return number of bytes written to buf
520 transmit_ready (void *cls, size_t size, void *buf)
522 struct NSEPeerEntry *peer_entry = cls;
525 peer_entry->th = NULL;
528 /* client disconnected */
531 GNUNET_assert (size >= sizeof (struct GNUNET_NSE_FloodMessage));
532 idx = estimate_index;
533 if (peer_entry->previous_round == GNUNET_NO)
535 idx = (idx + HISTORY_SIZE - 1) % HISTORY_SIZE;
536 peer_entry->previous_round = GNUNET_YES;
537 peer_entry->transmit_task =
538 GNUNET_SCHEDULER_add_delayed (get_transmit_delay (0), &transmit_task,
541 if ((ntohl (size_estimate_messages[idx].hop_count) == 0) &&
542 (GNUNET_SCHEDULER_NO_TASK != proof_task))
544 GNUNET_STATISTICS_update (stats,
545 "# flood messages not generated (no proof yet)",
550 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
551 "In round %llu, sending to `%s' estimate with %u bits\n",
553 GNUNET_TIME_absolute_ntoh (size_estimate_messages[idx].
554 timestamp).abs_value,
555 GNUNET_i2s (&peer_entry->id),
556 (unsigned int) ntohl (size_estimate_messages[idx].matching_bits));
558 if (ntohl (size_estimate_messages[idx].hop_count) == 0)
559 GNUNET_STATISTICS_update (stats, "# flood messages started", 1, GNUNET_NO);
560 GNUNET_STATISTICS_update (stats, "# flood messages transmitted", 1,
562 memcpy (buf, &size_estimate_messages[idx],
563 sizeof (struct GNUNET_NSE_FloodMessage));
564 GNUNET_STATISTICS_update (stats, "# flood messages sent", 1, GNUNET_NO);
565 return sizeof (struct GNUNET_NSE_FloodMessage);
570 * Task that triggers a NSE P2P transmission.
572 * @param cls the 'struct NSEPeerEntry'
573 * @param tc scheduler context
576 transmit_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
578 struct NSEPeerEntry *peer_entry = cls;
580 peer_entry->transmit_task = GNUNET_SCHEDULER_NO_TASK;
581 GNUNET_assert (NULL == peer_entry->th);
583 GNUNET_CORE_notify_transmit_ready (coreAPI, GNUNET_NO, NSE_PRIORITY,
584 GNUNET_TIME_UNIT_FOREVER_REL,
587 GNUNET_NSE_FloodMessage),
588 &transmit_ready, peer_entry);
593 * We've sent on our flood message or one that we received which was
594 * validated and closer than ours. Update the global list of recent
595 * messages and the average. Also re-broadcast the message to any
599 update_network_size_estimate ()
601 struct GNUNET_NSE_ClientMessage em;
603 setup_estimate_message (&em);
604 GNUNET_SERVER_notification_context_broadcast (nc, &em.header, GNUNET_YES);
609 * Setup a flood message in our history array at the given
610 * slot offset for the given timestamp.
612 * @param slot index to use
613 * @param ts timestamp to use
616 setup_flood_message (unsigned int slot, struct GNUNET_TIME_Absolute ts)
618 struct GNUNET_NSE_FloodMessage *fm;
619 uint32_t matching_bits;
621 matching_bits = get_matching_bits (ts, &my_identity);
622 fm = &size_estimate_messages[slot];
623 fm->header.size = htons (sizeof (struct GNUNET_NSE_FloodMessage));
624 fm->header.type = htons (GNUNET_MESSAGE_TYPE_NSE_P2P_FLOOD);
625 fm->hop_count = htonl (0);
626 fm->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_NSE_SEND);
628 htonl (sizeof (struct GNUNET_NSE_FloodMessage) -
629 sizeof (struct GNUNET_MessageHeader) - sizeof (uint32_t) -
630 sizeof (struct GNUNET_CRYPTO_RsaSignature));
631 fm->matching_bits = htonl (matching_bits);
632 fm->timestamp = GNUNET_TIME_absolute_hton (ts);
633 fm->pkey = my_public_key;
634 fm->proof_of_work = my_proof;
635 GNUNET_assert (GNUNET_OK ==
636 GNUNET_CRYPTO_rsa_sign (my_private_key, &fm->purpose, &fm->signature));
641 * Schedule transmission for the given peer for the current round based
642 * on what we know about the desired delay.
645 * @param key hash of peer identity
646 * @param value the 'struct NSEPeerEntry'
647 * @return GNUNET_OK (continue to iterate)
650 schedule_current_round (void *cls, const GNUNET_HashCode * key, void *value)
652 struct NSEPeerEntry *peer_entry = value;
653 struct GNUNET_TIME_Relative delay;
655 if (peer_entry->th != NULL)
657 peer_entry->previous_round = GNUNET_NO;
660 if (peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK)
662 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
663 peer_entry->previous_round = GNUNET_NO;
666 get_transmit_delay ((peer_entry->previous_round == GNUNET_NO) ? -1 : 0);
667 peer_entry->transmit_task =
668 GNUNET_SCHEDULER_add_delayed (delay, &transmit_task, peer_entry);
674 * Update our flood message to be sent (and our timestamps).
677 * @param tc context for this message
680 update_flood_message (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
682 struct GNUNET_TIME_Relative offset;
685 flood_task = GNUNET_SCHEDULER_NO_TASK;
686 offset = GNUNET_TIME_absolute_get_remaining (next_timestamp);
687 if (0 != offset.rel_value)
689 /* somehow run early, delay more */
691 GNUNET_SCHEDULER_add_delayed (offset, &update_flood_message, NULL);
694 current_timestamp = next_timestamp;
696 GNUNET_TIME_absolute_add (current_timestamp, gnunet_nse_interval);
697 estimate_index = (estimate_index + 1) % HISTORY_SIZE;
698 if (estimate_count < HISTORY_SIZE)
700 if (next_timestamp.abs_value ==
701 GNUNET_TIME_absolute_ntoh (next_message.timestamp).abs_value)
703 /* we received a message for this round way early, use it! */
704 size_estimate_messages[estimate_index] = next_message;
705 size_estimate_messages[estimate_index].hop_count =
706 htonl (1 + ntohl (next_message.hop_count));
709 setup_flood_message (estimate_index, current_timestamp);
710 next_message.matching_bits = htonl (0); /* reset for 'next' round */
712 for (i = 0; i < HISTORY_SIZE; i++)
714 GNUNET_MAX (ntohl (size_estimate_messages[i].hop_count), hop_count_max);
715 GNUNET_CONTAINER_multihashmap_iterate (peers, &schedule_current_round, NULL);
717 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_absolute_get_remaining
718 (next_timestamp), &update_flood_message,
724 * Count the leading zeroes in hash.
727 * @return the number of leading zero bits.
730 count_leading_zeroes (const GNUNET_HashCode * hash)
732 unsigned int hash_count;
735 while ((0 == GNUNET_CRYPTO_hash_get_bit (hash, hash_count)))
742 * Check whether the given public key
743 * and integer are a valid proof of work.
745 * @param pkey the public key
746 * @param val the integer
748 * @return GNUNET_YES if valid, GNUNET_NO if not
751 check_proof_of_work (const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *pkey,
754 char buf[sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded) +
756 GNUNET_HashCode result;
758 memcpy (buf, &val, sizeof (val));
759 memcpy (&buf[sizeof (val)], pkey,
760 sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded));
761 GNUNET_CRYPTO_hash (buf, sizeof (buf), &result);
762 return (count_leading_zeroes (&result) >=
763 nse_work_required) ? GNUNET_YES : GNUNET_NO;
768 * Write our current proof to disk.
776 GNUNET_CONFIGURATION_get_value_filename (cfg, "NSE", "PROOFFILE", &proof))
778 if (sizeof (my_proof) !=
779 GNUNET_DISK_fn_write (proof, &my_proof, sizeof (my_proof),
780 GNUNET_DISK_PERM_USER_READ |
781 GNUNET_DISK_PERM_USER_WRITE))
782 GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "write", proof);
789 * Find our proof of work.
791 * @param cls closure (unused)
792 * @param tc task context
795 find_proof (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
797 #define ROUND_SIZE 10
799 char buf[sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded) +
801 GNUNET_HashCode result;
804 proof_task = GNUNET_SCHEDULER_NO_TASK;
805 memcpy (&buf[sizeof (uint64_t)], &my_public_key,
806 sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded));
809 while ((counter != UINT64_MAX) && (i < ROUND_SIZE))
811 memcpy (buf, &counter, sizeof (uint64_t));
812 GNUNET_CRYPTO_hash (buf, sizeof (buf), &result);
813 if (nse_work_required <= count_leading_zeroes (&result))
817 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Proof of work found: %llu!\n",
818 (unsigned long long) GNUNET_ntohll (counter));
820 for (i = 0; i < HISTORY_SIZE; i++)
821 if (ntohl (size_estimate_messages[i].hop_count) == 0)
823 size_estimate_messages[i].proof_of_work = my_proof;
824 GNUNET_assert (GNUNET_OK ==
825 GNUNET_CRYPTO_rsa_sign (my_private_key,
826 &size_estimate_messages[i].purpose,
827 &size_estimate_messages[i].signature));
835 if (my_proof / (100 * ROUND_SIZE) < counter / (100 * ROUND_SIZE))
838 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Testing proofs currently at %llu\n",
839 (unsigned long long) counter);
841 /* remember progress every 100 rounds */
850 GNUNET_SCHEDULER_add_delayed (proof_find_delay, &find_proof, NULL);
855 * An incoming flood message has been received which claims
856 * to have more bits matching than any we know in this time
857 * period. Verify the signature and/or proof of work.
859 * @param incoming_flood the message to verify
861 * @return GNUNET_YES if the message is verified
862 * GNUNET_NO if the key/signature don't verify
865 verify_message_crypto (const struct GNUNET_NSE_FloodMessage *incoming_flood)
868 check_proof_of_work (&incoming_flood->pkey,
869 incoming_flood->proof_of_work))
871 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Proof of work invalid: %llu!\n"),
873 GNUNET_ntohll (incoming_flood->proof_of_work));
878 GNUNET_CRYPTO_rsa_verify (GNUNET_SIGNATURE_PURPOSE_NSE_SEND,
879 &incoming_flood->purpose,
880 &incoming_flood->signature,
881 &incoming_flood->pkey))
891 * Update transmissions for the given peer for the current round based
892 * on updated proximity information.
894 * @param cls peer entry to exclude from updates
895 * @param key hash of peer identity
896 * @param value the 'struct NSEPeerEntry'
897 * @return GNUNET_OK (continue to iterate)
900 update_flood_times (void *cls, const GNUNET_HashCode * key, void *value)
902 struct NSEPeerEntry *exclude = cls;
903 struct NSEPeerEntry *peer_entry = value;
904 struct GNUNET_TIME_Relative delay;
906 if (peer_entry->th != NULL)
907 return GNUNET_OK; /* already active */
908 if (peer_entry == exclude)
909 return GNUNET_OK; /* trigger of the update */
910 if (peer_entry->previous_round == GNUNET_NO)
912 /* still stuck in previous round, no point to update, check that
913 * we are active here though... */
914 GNUNET_break ((peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK) ||
915 (peer_entry->th != NULL));
918 if (peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK)
920 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
921 peer_entry->transmit_task = GNUNET_SCHEDULER_NO_TASK;
923 delay = get_transmit_delay (0);
924 peer_entry->transmit_task =
925 GNUNET_SCHEDULER_add_delayed (delay, &transmit_task, peer_entry);
931 * Core handler for size estimate flooding messages.
933 * @param cls closure unused
934 * @param message message
935 * @param peer peer identity this message is from (ignored)
936 * @param atsi performance data (ignored)
940 handle_p2p_size_estimate (void *cls, const struct GNUNET_PeerIdentity *peer,
941 const struct GNUNET_MessageHeader *message,
942 const struct GNUNET_TRANSPORT_ATS_Information *atsi)
944 const struct GNUNET_NSE_FloodMessage *incoming_flood;
945 struct GNUNET_TIME_Absolute ts;
946 struct NSEPeerEntry *peer_entry;
947 uint32_t matching_bits;
952 GNUNET_BIO_write_int64 (wh, GNUNET_TIME_absolute_get ().abs_value);
954 incoming_flood = (const struct GNUNET_NSE_FloodMessage *) message;
955 GNUNET_STATISTICS_update (stats, "# flood messages received", 1, GNUNET_NO);
956 matching_bits = ntohl (incoming_flood->matching_bits);
961 struct GNUNET_PeerIdentity os;
963 GNUNET_CRYPTO_hash (&incoming_flood->pkey,
964 sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
966 GNUNET_snprintf (origin, sizeof (origin), "%s", GNUNET_i2s (&os));
967 GNUNET_snprintf (pred, sizeof (pred), "%s", GNUNET_i2s (peer));
968 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
969 "Flood at %llu from `%s' via `%s' at `%s' with bits %u\n",
971 GNUNET_TIME_absolute_ntoh (incoming_flood->timestamp).abs_value,
972 origin, pred, GNUNET_i2s (&my_identity),
973 (unsigned int) matching_bits);
977 peer_entry = GNUNET_CONTAINER_multihashmap_get (peers, &peer->hashPubKey);
978 if (NULL == peer_entry)
984 ts = GNUNET_TIME_absolute_ntoh (incoming_flood->timestamp);
986 if (ts.abs_value == current_timestamp.abs_value)
987 idx = estimate_index;
988 else if (ts.abs_value ==
989 current_timestamp.abs_value - gnunet_nse_interval.rel_value)
990 idx = (estimate_index + HISTORY_SIZE - 1) % HISTORY_SIZE;
991 else if (ts.abs_value ==
992 next_timestamp.abs_value - gnunet_nse_interval.rel_value)
994 if (matching_bits <= ntohl (next_message.matching_bits))
995 return GNUNET_OK; /* ignore, simply too early/late */
996 if (GNUNET_YES != verify_message_crypto (incoming_flood))
1001 next_message = *incoming_flood;
1006 GNUNET_STATISTICS_update (stats,
1007 "# flood messages discarded (clock skew too large)",
1011 if (0 == (memcmp (peer, &my_identity, sizeof (struct GNUNET_PeerIdentity))))
1013 /* send to self, update our own estimate IF this also comes from us! */
1015 memcmp (&incoming_flood->pkey, &my_public_key, sizeof (my_public_key)))
1016 update_network_size_estimate ();
1019 if (matching_bits >= ntohl (size_estimate_messages[idx].matching_bits))
1021 /* cancel transmission from us to this peer for this round */
1022 if (idx == estimate_index)
1024 if (peer_entry->previous_round == GNUNET_YES)
1026 /* cancel any activity for current round */
1027 if (peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK)
1029 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
1030 peer_entry->transmit_task = GNUNET_SCHEDULER_NO_TASK;
1032 if (peer_entry->th != NULL)
1034 GNUNET_CORE_notify_transmit_ready_cancel (peer_entry->th);
1035 peer_entry->th = NULL;
1041 /* cancel previous round only */
1042 peer_entry->previous_round = GNUNET_YES;
1045 if (matching_bits == ntohl (size_estimate_messages[idx].matching_bits))
1047 if (matching_bits <= ntohl (size_estimate_messages[idx].matching_bits))
1049 if ((idx < estimate_index) && (peer_entry->previous_round == GNUNET_YES))
1050 peer_entry->previous_round = GNUNET_NO;
1051 /* push back our result now, that peer is spreading bad information... */
1052 if (NULL == peer_entry->th)
1054 if (peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK)
1055 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
1056 peer_entry->transmit_task =
1057 GNUNET_SCHEDULER_add_now (&transmit_task, peer_entry);
1059 /* Not closer than our most recent message, no need to do work here */
1060 GNUNET_STATISTICS_update (stats,
1061 "# flood messages ignored (had closer already)",
1065 if (GNUNET_YES != verify_message_crypto (incoming_flood))
1067 GNUNET_break_op (0);
1070 size_estimate_messages[idx] = *incoming_flood;
1071 size_estimate_messages[idx].hop_count =
1072 htonl (ntohl (incoming_flood->hop_count) + 1);
1074 GNUNET_MAX (ntohl (incoming_flood->hop_count) + 1, hop_count_max);
1076 /* have a new, better size estimate, inform clients */
1077 update_network_size_estimate ();
1080 GNUNET_CONTAINER_multihashmap_iterate (peers, &update_flood_times,
1088 * Method called whenever a peer connects.
1090 * @param cls closure
1091 * @param peer peer identity this notification is about
1092 * @param atsi performance data
1095 handle_core_connect (void *cls, const struct GNUNET_PeerIdentity *peer,
1096 const struct GNUNET_TRANSPORT_ATS_Information *atsi)
1098 struct NSEPeerEntry *peer_entry;
1101 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Peer `%s' connected to us\n",
1104 peer_entry = GNUNET_malloc (sizeof (struct NSEPeerEntry));
1105 peer_entry->id = *peer;
1106 GNUNET_CONTAINER_multihashmap_put (peers, &peer->hashPubKey, peer_entry,
1107 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
1108 peer_entry->transmit_task =
1109 GNUNET_SCHEDULER_add_delayed (get_transmit_delay (-1), &transmit_task,
1115 * Method called whenever a peer disconnects.
1117 * @param cls closure
1118 * @param peer peer identity this notification is about
1121 handle_core_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer)
1123 struct NSEPeerEntry *pos;
1126 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Peer `%s' disconnected from us\n",
1129 pos = GNUNET_CONTAINER_multihashmap_get (peers, &peer->hashPubKey);
1135 GNUNET_assert (GNUNET_YES ==
1136 GNUNET_CONTAINER_multihashmap_remove (peers, &peer->hashPubKey,
1138 if (pos->transmit_task != GNUNET_SCHEDULER_NO_TASK)
1139 GNUNET_SCHEDULER_cancel (pos->transmit_task);
1140 if (pos->th != NULL)
1142 GNUNET_CORE_notify_transmit_ready_cancel (pos->th);
1150 * Task run during shutdown.
1156 shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1158 if (flood_task != GNUNET_SCHEDULER_NO_TASK)
1160 GNUNET_SCHEDULER_cancel (flood_task);
1161 flood_task = GNUNET_SCHEDULER_NO_TASK;
1163 if (proof_task != GNUNET_SCHEDULER_NO_TASK)
1165 GNUNET_SCHEDULER_cancel (proof_task);
1166 proof_task = GNUNET_SCHEDULER_NO_TASK;
1167 write_proof (); /* remember progress */
1171 GNUNET_SERVER_notification_context_destroy (nc);
1174 if (coreAPI != NULL)
1176 GNUNET_CORE_disconnect (coreAPI);
1181 GNUNET_STATISTICS_destroy (stats, GNUNET_NO);
1186 GNUNET_CONTAINER_multihashmap_destroy (peers);
1189 if (my_private_key != NULL)
1191 GNUNET_CRYPTO_rsa_key_free (my_private_key);
1192 my_private_key = NULL;
1194 #if ENABLE_HISTOGRAM
1197 GNUNET_BIO_write_close (wh);
1205 * Called on core init/fail.
1207 * @param cls service closure
1208 * @param server handle to the server for this service
1209 * @param identity the public identity of this peer
1210 * @param publicKey the public key of this peer
1213 core_init (void *cls, struct GNUNET_CORE_Handle *server,
1214 const struct GNUNET_PeerIdentity *identity,
1215 const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *publicKey)
1217 struct GNUNET_TIME_Absolute now;
1218 struct GNUNET_TIME_Absolute prev_time;
1224 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connection to core FAILED!\n");
1226 GNUNET_SCHEDULER_shutdown ();
1230 memcmp (&my_identity, identity,
1231 sizeof (struct GNUNET_PeerIdentity)));
1232 now = GNUNET_TIME_absolute_get ();
1233 current_timestamp.abs_value =
1234 (now.abs_value / gnunet_nse_interval.rel_value) *
1235 gnunet_nse_interval.rel_value;
1236 next_timestamp.abs_value =
1237 current_timestamp.abs_value + gnunet_nse_interval.rel_value;
1239 for (i = 0; i < HISTORY_SIZE; i++)
1241 prev_time.abs_value =
1242 current_timestamp.abs_value - (HISTORY_SIZE - i -
1243 1) * gnunet_nse_interval.rel_value;
1244 setup_flood_message (i, prev_time);
1246 estimate_index = HISTORY_SIZE - 1;
1249 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_absolute_get_remaining
1250 (next_timestamp), &update_flood_message,
1256 * Handle network size estimate clients.
1258 * @param cls closure
1259 * @param server the initialized server
1260 * @param c configuration to use
1263 run (void *cls, struct GNUNET_SERVER_Handle *server,
1264 const struct GNUNET_CONFIGURATION_Handle *c)
1269 static const struct GNUNET_SERVER_MessageHandler handlers[] = {
1270 {&handle_start_message, NULL, GNUNET_MESSAGE_TYPE_NSE_START,
1271 sizeof (struct GNUNET_MessageHeader)},
1274 static const struct GNUNET_CORE_MessageHandler core_handlers[] = {
1275 {&handle_p2p_size_estimate, GNUNET_MESSAGE_TYPE_NSE_P2P_FLOOD,
1276 sizeof (struct GNUNET_NSE_FloodMessage)},
1282 GNUNET_CONFIGURATION_get_value_time (cfg, "NSE", "INTERVAL",
1283 &gnunet_nse_interval)) ||
1285 GNUNET_CONFIGURATION_get_value_time (cfg, "NSE", "WORKDELAY",
1286 &proof_find_delay)) ||
1288 GNUNET_CONFIGURATION_get_value_number (cfg, "NSE", "WORKBITS",
1289 &nse_work_required)))
1291 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1293 ("NSE service is lacking key configuration settings. Exiting.\n"));
1294 GNUNET_SCHEDULER_shutdown ();
1297 if (nse_work_required >= sizeof (GNUNET_HashCode) * 8)
1299 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1300 _("Invalid work requirement for NSE service. Exiting.\n"));
1301 GNUNET_SCHEDULER_shutdown ();
1307 GNUNET_CONFIGURATION_get_value_filename (cfg, "GNUNETD", "HOSTKEY",
1310 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1312 ("NSE service is lacking key configuration settings. Exiting.\n"));
1313 GNUNET_SCHEDULER_shutdown ();
1316 my_private_key = GNUNET_CRYPTO_rsa_key_create_from_file (keyfile);
1317 GNUNET_free (keyfile);
1318 if (my_private_key == NULL)
1320 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1321 _("NSE service could not access hostkey. Exiting.\n"));
1322 GNUNET_SCHEDULER_shutdown ();
1325 GNUNET_CRYPTO_rsa_key_get_public (my_private_key, &my_public_key);
1326 GNUNET_CRYPTO_hash (&my_public_key, sizeof (my_public_key),
1327 &my_identity.hashPubKey);
1329 GNUNET_CONFIGURATION_get_value_filename (cfg, "NSE", "PROOFFILE", &proof))
1331 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1333 ("NSE service is lacking key configuration settings. Exiting.\n"));
1334 if (my_private_key != NULL)
1336 GNUNET_CRYPTO_rsa_key_free (my_private_key);
1337 my_private_key = NULL;
1339 GNUNET_SCHEDULER_shutdown ();
1342 if ((GNUNET_YES != GNUNET_DISK_file_test (proof)) ||
1343 (sizeof (my_proof) !=
1344 GNUNET_DISK_fn_read (proof, &my_proof, sizeof (my_proof))))
1346 GNUNET_free (proof);
1348 GNUNET_SCHEDULER_add_with_priority (GNUNET_SCHEDULER_PRIORITY_IDLE,
1351 peers = GNUNET_CONTAINER_multihashmap_create (128);
1352 GNUNET_SERVER_add_handlers (server, handlers);
1353 nc = GNUNET_SERVER_notification_context_create (server, 1);
1354 /* Connect to core service and register core handlers */
1355 coreAPI = GNUNET_CORE_connect (cfg, /* Main configuration */
1356 CORE_QUEUE_SIZE, /* queue size */
1357 NULL, /* Closure passed to functions */
1358 &core_init, /* Call core_init once connected */
1359 &handle_core_connect, /* Handle connects */
1360 &handle_core_disconnect, /* Handle disconnects */
1361 NULL, /* Do we care about "status" updates? */
1362 NULL, /* Don't want notified about all incoming messages */
1363 GNUNET_NO, /* For header only inbound notification */
1364 NULL, /* Don't want notified about all outbound messages */
1365 GNUNET_NO, /* For header only outbound notification */
1366 core_handlers); /* Register these handlers */
1367 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &shutdown_task,
1369 #if ENABLE_HISTOGRAM
1371 GNUNET_CONFIGURATION_get_value_filename (cfg, "NSE", "HISTOGRAM", &proof))
1373 wh = GNUNET_BIO_write_open (proof);
1374 GNUNET_free (proof);
1377 if (coreAPI == NULL)
1379 GNUNET_SCHEDULER_shutdown ();
1382 stats = GNUNET_STATISTICS_create ("nse", cfg);
1387 * The main function for the statistics service.
1389 * @param argc number of arguments from the command line
1390 * @param argv command line arguments
1391 * @return 0 ok, 1 on error
1394 main (int argc, char *const *argv)
1396 return (GNUNET_OK ==
1397 GNUNET_SERVICE_run (argc, argv, "nse", GNUNET_SERVICE_OPTION_NONE,
1398 &run, NULL)) ? 0 : 1;
1401 /* end of gnunet-service-nse.c */