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
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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++)
318 val = htonl (size_estimate_messages[(estimate_index - i + HISTORY_SIZE)
319 % HISTORY_SIZE].matching_bits);
320 weight = 1; /* was: estimate_count + 1 - i; */
322 temp = weight + sumweight;
324 r = q * weight / temp;
325 sum += sumweight * q * r;
329 variance = sum / (sumweight - 1.0);
330 GNUNET_assert (variance >= 0);
331 std_dev = sqrt (variance);
332 current_std_dev = std_dev;
333 current_size_estimate = mean;
335 em->header.size = htons (sizeof (struct GNUNET_NSE_ClientMessage));
336 em->header.type = htons (GNUNET_MESSAGE_TYPE_NSE_ESTIMATE);
337 em->reserved = htonl (0);
338 em->timestamp = GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
339 em->size_estimate = mean - 1.0 / 3.0;
340 em->std_deviation = std_dev;
341 GNUNET_STATISTICS_set (stats,
342 "# nodes in the network (estimate)",
343 (uint64_t) pow (2, mean - 1.0 / 3.0), GNUNET_NO);
348 * Handler for START message from client, triggers an
349 * immediate current network estimate notification.
350 * Also, we remember the client for updates upon future
351 * estimate measurements.
354 * @param client who sent the message
355 * @param message the message received
358 handle_start_message (void *cls, struct GNUNET_SERVER_Client *client,
359 const struct GNUNET_MessageHeader *message)
361 struct GNUNET_NSE_ClientMessage em;
364 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received START message from client\n");
366 GNUNET_SERVER_notification_context_add (nc, client);
367 setup_estimate_message (&em);
368 GNUNET_SERVER_notification_context_unicast (nc, client, &em.header,
370 GNUNET_SERVER_receive_done (client, GNUNET_OK);
375 * How long should we delay a message to go the given number of
378 * @param matching_bits number of matching bits to consider
381 get_matching_bits_delay (uint32_t matching_bits)
383 /* Calculated as: S + f/2 - (f / pi) * (atan(x - p')) */
384 // S is next_timestamp (ignored in return value)
385 // f is frequency (gnunet_nse_interval)
386 // x is matching_bits
387 // p' is current_size_estimate
388 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;
409 ret.rel_value = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
410 (uint32_t) (get_matching_bits_delay
413 (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,
436 sizeof (timestamp.abs_value), ×tamp_hash);
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,
556 "# flood messages transmitted", 1, GNUNET_NO);
558 &size_estimate_messages[idx],
559 sizeof (struct GNUNET_NSE_FloodMessage));
560 GNUNET_STATISTICS_update (stats, "# flood messages sent", 1, GNUNET_NO);
561 return sizeof (struct GNUNET_NSE_FloodMessage);
566 * Task that triggers a NSE P2P transmission.
568 * @param cls the 'struct NSEPeerEntry'
569 * @param tc scheduler context
572 transmit_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
574 struct NSEPeerEntry *peer_entry = cls;
576 peer_entry->transmit_task = GNUNET_SCHEDULER_NO_TASK;
577 GNUNET_assert (NULL == peer_entry->th);
579 = GNUNET_CORE_notify_transmit_ready (coreAPI,
582 GNUNET_TIME_UNIT_FOREVER_REL,
585 GNUNET_NSE_FloodMessage),
586 &transmit_ready, peer_entry);
591 * We've sent on our flood message or one that we received which was
592 * validated and closer than ours. Update the global list of recent
593 * messages and the average. Also re-broadcast the message to any
597 update_network_size_estimate ()
599 struct GNUNET_NSE_ClientMessage em;
601 setup_estimate_message (&em);
602 GNUNET_SERVER_notification_context_broadcast (nc, &em.header, GNUNET_YES);
607 * Setup a flood message in our history array at the given
608 * slot offset for the given timestamp.
610 * @param slot index to use
611 * @param ts timestamp to use
614 setup_flood_message (unsigned int slot, struct GNUNET_TIME_Absolute ts)
616 struct GNUNET_NSE_FloodMessage *fm;
617 uint32_t matching_bits;
619 matching_bits = get_matching_bits (ts, &my_identity);
620 fm = &size_estimate_messages[slot];
621 fm->header.size = htons (sizeof (struct GNUNET_NSE_FloodMessage));
622 fm->header.type = htons (GNUNET_MESSAGE_TYPE_NSE_P2P_FLOOD);
623 fm->hop_count = htonl (0);
624 fm->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_NSE_SEND);
625 fm->purpose.size = htonl (sizeof (struct GNUNET_NSE_FloodMessage)
626 - sizeof (struct GNUNET_MessageHeader)
628 - sizeof (struct GNUNET_CRYPTO_RsaSignature));
629 fm->matching_bits = htonl (matching_bits);
630 fm->timestamp = GNUNET_TIME_absolute_hton (ts);
631 fm->pkey = my_public_key;
632 fm->proof_of_work = my_proof;
633 GNUNET_CRYPTO_rsa_sign (my_private_key, &fm->purpose, &fm->signature);
638 * Schedule transmission for the given peer for the current round based
639 * on what we know about the desired delay.
642 * @param key hash of peer identity
643 * @param value the 'struct NSEPeerEntry'
644 * @return GNUNET_OK (continue to iterate)
647 schedule_current_round (void *cls, const GNUNET_HashCode * key, void *value)
649 struct NSEPeerEntry *peer_entry = value;
650 struct GNUNET_TIME_Relative delay;
652 if (peer_entry->th != NULL)
654 peer_entry->previous_round = GNUNET_NO;
657 if (peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK)
659 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
660 peer_entry->previous_round = GNUNET_NO;
663 get_transmit_delay ((peer_entry->previous_round == GNUNET_NO) ? -1 : 0);
664 peer_entry->transmit_task =
665 GNUNET_SCHEDULER_add_delayed (delay, &transmit_task, peer_entry);
671 * Update our flood message to be sent (and our timestamps).
674 * @param tc context for this message
677 update_flood_message (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
679 struct GNUNET_TIME_Relative offset;
682 flood_task = GNUNET_SCHEDULER_NO_TASK;
683 offset = GNUNET_TIME_absolute_get_remaining (next_timestamp);
684 if (0 != offset.rel_value)
686 /* somehow run early, delay more */
688 = GNUNET_SCHEDULER_add_delayed (offset, &update_flood_message, NULL);
691 current_timestamp = next_timestamp;
692 next_timestamp = GNUNET_TIME_absolute_add (current_timestamp,
693 gnunet_nse_interval);
694 estimate_index = (estimate_index + 1) % HISTORY_SIZE;
695 if (estimate_count < HISTORY_SIZE)
697 if (next_timestamp.abs_value ==
698 GNUNET_TIME_absolute_ntoh (next_message.timestamp).abs_value)
700 /* we received a message for this round way early, use it! */
701 size_estimate_messages[estimate_index] = next_message;
702 size_estimate_messages[estimate_index].hop_count
703 = htonl (1 + ntohl (next_message.hop_count));
706 setup_flood_message (estimate_index, current_timestamp);
707 next_message.matching_bits = htonl (0); /* reset for 'next' round */
709 for (i = 0; i < HISTORY_SIZE; i++)
710 hop_count_max = GNUNET_MAX (ntohl (size_estimate_messages[i].hop_count),
712 GNUNET_CONTAINER_multihashmap_iterate (peers, &schedule_current_round, NULL);
714 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_absolute_get_remaining
715 (next_timestamp), &update_flood_message,
721 * Count the leading zeroes in hash.
724 * @return the number of leading zero bits.
727 count_leading_zeroes (const GNUNET_HashCode * hash)
729 unsigned int hash_count;
732 while ((0 == GNUNET_CRYPTO_hash_get_bit (hash, hash_count)))
739 * Check whether the given public key
740 * and integer are a valid proof of work.
742 * @param pkey the public key
743 * @param val the integer
745 * @return GNUNET_YES if valid, GNUNET_NO if not
748 check_proof_of_work (const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *pkey,
751 char buf[sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded) +
753 GNUNET_HashCode result;
755 memcpy (buf, &val, sizeof (val));
756 memcpy (&buf[sizeof (val)],
757 pkey, sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded));
758 GNUNET_CRYPTO_hash (buf, sizeof (buf), &result);
759 return (count_leading_zeroes (&result) >=
760 nse_work_required) ? GNUNET_YES : GNUNET_NO;
765 * Write our current proof to disk.
773 GNUNET_CONFIGURATION_get_value_filename (cfg, "NSE", "PROOFFILE", &proof))
775 if (sizeof (my_proof) !=
776 GNUNET_DISK_fn_write (proof,
779 GNUNET_DISK_PERM_USER_READ |
780 GNUNET_DISK_PERM_USER_WRITE))
781 GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "write", proof);
788 * Find our proof of work.
790 * @param cls closure (unused)
791 * @param tc task context
794 find_proof (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
796 #define ROUND_SIZE 10
798 char buf[sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded) +
800 GNUNET_HashCode result;
803 proof_task = GNUNET_SCHEDULER_NO_TASK;
804 memcpy (&buf[sizeof (uint64_t)],
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,
818 "Proof of work found: %llu!\n",
819 (unsigned long long) GNUNET_ntohll (counter));
821 for (i = 0; i < HISTORY_SIZE; i++)
822 if (ntohl (size_estimate_messages[i].hop_count) == 0)
824 size_estimate_messages[i].proof_of_work = my_proof;
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,
839 "Testing proofs currently at %llu\n",
840 (unsigned long long) counter);
842 /* remember progress every 100 rounds */
850 proof_task = GNUNET_SCHEDULER_add_delayed (proof_find_delay,
856 * An incoming flood message has been received which claims
857 * to have more bits matching than any we know in this time
858 * period. Verify the signature and/or proof of work.
860 * @param incoming_flood the message to verify
862 * @return GNUNET_YES if the message is verified
863 * GNUNET_NO if the key/signature don't verify
866 verify_message_crypto (const struct GNUNET_NSE_FloodMessage *incoming_flood)
869 check_proof_of_work (&incoming_flood->pkey,
870 incoming_flood->proof_of_work))
872 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
873 _("Proof of work invalid: %llu!\n"),
875 GNUNET_ntohll (incoming_flood->proof_of_work));
880 GNUNET_CRYPTO_rsa_verify (GNUNET_SIGNATURE_PURPOSE_NSE_SEND,
881 &incoming_flood->purpose,
882 &incoming_flood->signature,
883 &incoming_flood->pkey))
893 * Update transmissions for the given peer for the current round based
894 * on updated proximity information.
896 * @param cls peer entry to exclude from updates
897 * @param key hash of peer identity
898 * @param value the 'struct NSEPeerEntry'
899 * @return GNUNET_OK (continue to iterate)
902 update_flood_times (void *cls, const GNUNET_HashCode * key, void *value)
904 struct NSEPeerEntry *exclude = cls;
905 struct NSEPeerEntry *peer_entry = value;
906 struct GNUNET_TIME_Relative delay;
908 if (peer_entry->th != NULL)
909 return GNUNET_OK; /* already active */
910 if (peer_entry == exclude)
911 return GNUNET_OK; /* trigger of the update */
912 if (peer_entry->previous_round == GNUNET_NO)
914 /* still stuck in previous round, no point to update, check that
915 * we are active here though... */
916 GNUNET_break ((peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK) ||
917 (peer_entry->th != NULL));
920 if (peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK)
922 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
923 peer_entry->transmit_task = GNUNET_SCHEDULER_NO_TASK;
925 delay = get_transmit_delay (0);
926 peer_entry->transmit_task = GNUNET_SCHEDULER_add_delayed (delay,
934 * Core handler for size estimate flooding messages.
936 * @param cls closure unused
937 * @param message message
938 * @param peer peer identity this message is from (ignored)
939 * @param atsi performance data (ignored)
943 handle_p2p_size_estimate (void *cls,
944 const struct GNUNET_PeerIdentity *peer,
945 const struct GNUNET_MessageHeader *message,
946 const struct GNUNET_TRANSPORT_ATS_Information *atsi)
948 const struct GNUNET_NSE_FloodMessage *incoming_flood;
949 struct GNUNET_TIME_Absolute ts;
950 struct NSEPeerEntry *peer_entry;
951 uint32_t matching_bits;
956 GNUNET_BIO_write_int64 (wh, GNUNET_TIME_absolute_get ().abs_value);
958 incoming_flood = (const struct GNUNET_NSE_FloodMessage *) message;
959 GNUNET_STATISTICS_update (stats, "# flood messages received", 1, GNUNET_NO);
960 matching_bits = ntohl (incoming_flood->matching_bits);
965 struct GNUNET_PeerIdentity os;
967 GNUNET_CRYPTO_hash (&incoming_flood->pkey,
968 sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
970 GNUNET_snprintf (origin, sizeof (origin), "%s", GNUNET_i2s (&os));
971 GNUNET_snprintf (pred, sizeof (pred), "%s", GNUNET_i2s (peer));
972 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
973 "Flood at %llu from `%s' via `%s' at `%s' with bits %u\n",
975 GNUNET_TIME_absolute_ntoh (incoming_flood->timestamp).abs_value,
976 origin, pred, GNUNET_i2s (&my_identity),
977 (unsigned int) matching_bits);
981 peer_entry = GNUNET_CONTAINER_multihashmap_get (peers, &peer->hashPubKey);
982 if (NULL == peer_entry)
988 ts = GNUNET_TIME_absolute_ntoh (incoming_flood->timestamp);
990 if (ts.abs_value == current_timestamp.abs_value)
991 idx = estimate_index;
992 else if (ts.abs_value ==
993 current_timestamp.abs_value - gnunet_nse_interval.rel_value)
994 idx = (estimate_index + HISTORY_SIZE - 1) % HISTORY_SIZE;
995 else if (ts.abs_value ==
996 next_timestamp.abs_value - gnunet_nse_interval.rel_value)
998 if (matching_bits <= ntohl (next_message.matching_bits))
999 return GNUNET_OK; /* ignore, simply too early/late */
1000 if (GNUNET_YES != verify_message_crypto (incoming_flood))
1002 GNUNET_break_op (0);
1005 next_message = *incoming_flood;
1010 GNUNET_STATISTICS_update (stats,
1011 "# flood messages discarded (clock skew too large)",
1015 if (0 == (memcmp (peer, &my_identity, sizeof (struct GNUNET_PeerIdentity))))
1017 /* send to self, update our own estimate IF this also comes from us! */
1018 if (0 == memcmp (&incoming_flood->pkey,
1019 &my_public_key, sizeof (my_public_key)))
1020 update_network_size_estimate ();
1023 if (matching_bits >= ntohl (size_estimate_messages[idx].matching_bits))
1025 /* cancel transmission from us to this peer for this round */
1026 if (idx == estimate_index)
1028 if (peer_entry->previous_round == GNUNET_YES)
1030 /* cancel any activity for current round */
1031 if (peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK)
1033 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
1034 peer_entry->transmit_task = GNUNET_SCHEDULER_NO_TASK;
1036 if (peer_entry->th != NULL)
1038 GNUNET_CORE_notify_transmit_ready_cancel (peer_entry->th);
1039 peer_entry->th = NULL;
1045 /* cancel previous round only */
1046 peer_entry->previous_round = GNUNET_YES;
1049 if (matching_bits == ntohl (size_estimate_messages[idx].matching_bits))
1051 if (matching_bits <= ntohl (size_estimate_messages[idx].matching_bits))
1053 if ((idx < estimate_index) && (peer_entry->previous_round == GNUNET_YES))
1054 peer_entry->previous_round = GNUNET_NO;
1055 /* push back our result now, that peer is spreading bad information... */
1056 if (NULL == peer_entry->th)
1058 if (peer_entry->transmit_task != GNUNET_SCHEDULER_NO_TASK)
1059 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
1060 peer_entry->transmit_task = GNUNET_SCHEDULER_add_now (&transmit_task,
1063 /* Not closer than our most recent message, no need to do work here */
1064 GNUNET_STATISTICS_update (stats,
1065 "# flood messages ignored (had closer already)",
1069 if (GNUNET_YES != verify_message_crypto (incoming_flood))
1071 GNUNET_break_op (0);
1074 size_estimate_messages[idx] = *incoming_flood;
1075 size_estimate_messages[idx].hop_count =
1076 htonl (ntohl (incoming_flood->hop_count) + 1);
1078 GNUNET_MAX (ntohl (incoming_flood->hop_count) + 1, hop_count_max);
1080 /* have a new, better size estimate, inform clients */
1081 update_network_size_estimate ();
1084 GNUNET_CONTAINER_multihashmap_iterate (peers,
1085 &update_flood_times, peer_entry);
1092 * Method called whenever a peer connects.
1094 * @param cls closure
1095 * @param peer peer identity this notification is about
1096 * @param atsi performance data
1099 handle_core_connect (void *cls, const struct GNUNET_PeerIdentity *peer,
1100 const struct GNUNET_TRANSPORT_ATS_Information *atsi)
1102 struct NSEPeerEntry *peer_entry;
1105 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1106 "Peer `%s' connected to us\n", GNUNET_i2s (peer));
1108 peer_entry = GNUNET_malloc (sizeof (struct NSEPeerEntry));
1109 peer_entry->id = *peer;
1110 GNUNET_CONTAINER_multihashmap_put (peers,
1113 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
1114 peer_entry->transmit_task =
1115 GNUNET_SCHEDULER_add_delayed (get_transmit_delay (-1), &transmit_task,
1121 * Method called whenever a peer disconnects.
1123 * @param cls closure
1124 * @param peer peer identity this notification is about
1127 handle_core_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer)
1129 struct NSEPeerEntry *pos;
1132 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1133 "Peer `%s' disconnected from us\n", GNUNET_i2s (peer));
1135 pos = GNUNET_CONTAINER_multihashmap_get (peers, &peer->hashPubKey);
1141 GNUNET_assert (GNUNET_YES ==
1142 GNUNET_CONTAINER_multihashmap_remove (peers,
1143 &peer->hashPubKey, pos));
1144 if (pos->transmit_task != GNUNET_SCHEDULER_NO_TASK)
1145 GNUNET_SCHEDULER_cancel (pos->transmit_task);
1146 if (pos->th != NULL)
1148 GNUNET_CORE_notify_transmit_ready_cancel (pos->th);
1156 * Task run during shutdown.
1162 shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1164 if (flood_task != GNUNET_SCHEDULER_NO_TASK)
1166 GNUNET_SCHEDULER_cancel (flood_task);
1167 flood_task = GNUNET_SCHEDULER_NO_TASK;
1169 if (proof_task != GNUNET_SCHEDULER_NO_TASK)
1171 GNUNET_SCHEDULER_cancel (proof_task);
1172 proof_task = GNUNET_SCHEDULER_NO_TASK;
1173 write_proof (); /* remember progress */
1177 GNUNET_SERVER_notification_context_destroy (nc);
1180 if (coreAPI != NULL)
1182 GNUNET_CORE_disconnect (coreAPI);
1187 GNUNET_STATISTICS_destroy (stats, GNUNET_NO);
1192 GNUNET_CONTAINER_multihashmap_destroy (peers);
1195 if (my_private_key != NULL)
1197 GNUNET_CRYPTO_rsa_key_free (my_private_key);
1198 my_private_key = NULL;
1200 #if ENABLE_HISTOGRAM
1203 GNUNET_BIO_write_close (wh);
1211 * Called on core init/fail.
1213 * @param cls service closure
1214 * @param server handle to the server for this service
1215 * @param identity the public identity of this peer
1216 * @param publicKey the public key of this peer
1219 core_init (void *cls, struct GNUNET_CORE_Handle *server,
1220 const struct GNUNET_PeerIdentity *identity,
1221 const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *publicKey)
1223 struct GNUNET_TIME_Absolute now;
1224 struct GNUNET_TIME_Absolute prev_time;
1230 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connection to core FAILED!\n");
1232 GNUNET_SCHEDULER_shutdown ();
1236 memcmp (&my_identity, identity,
1237 sizeof (struct GNUNET_PeerIdentity)));
1238 now = GNUNET_TIME_absolute_get ();
1239 current_timestamp.abs_value =
1240 (now.abs_value / gnunet_nse_interval.rel_value) *
1241 gnunet_nse_interval.rel_value;
1242 next_timestamp.abs_value =
1243 current_timestamp.abs_value + gnunet_nse_interval.rel_value;
1245 for (i = 0; i < HISTORY_SIZE; i++)
1247 prev_time.abs_value =
1248 current_timestamp.abs_value - (HISTORY_SIZE - i -
1249 1) * gnunet_nse_interval.rel_value;
1250 setup_flood_message (i, prev_time);
1252 estimate_index = HISTORY_SIZE - 1;
1256 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_absolute_get_remaining
1257 (next_timestamp), &update_flood_message,
1263 * Handle network size estimate clients.
1265 * @param cls closure
1266 * @param server the initialized server
1267 * @param c configuration to use
1270 run (void *cls, struct GNUNET_SERVER_Handle *server,
1271 const struct GNUNET_CONFIGURATION_Handle *c)
1276 static const struct GNUNET_SERVER_MessageHandler handlers[] = {
1277 {&handle_start_message, NULL, GNUNET_MESSAGE_TYPE_NSE_START,
1278 sizeof (struct GNUNET_MessageHeader)},
1281 static const struct GNUNET_CORE_MessageHandler core_handlers[] = {
1282 {&handle_p2p_size_estimate, GNUNET_MESSAGE_TYPE_NSE_P2P_FLOOD,
1283 sizeof (struct GNUNET_NSE_FloodMessage)},
1289 GNUNET_CONFIGURATION_get_value_time (cfg,
1291 &gnunet_nse_interval)) ||
1293 GNUNET_CONFIGURATION_get_value_time (cfg,
1295 &proof_find_delay)) ||
1297 GNUNET_CONFIGURATION_get_value_number (cfg,
1299 &nse_work_required)))
1301 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1303 ("NSE service is lacking key configuration settings. Exiting.\n"));
1304 GNUNET_SCHEDULER_shutdown ();
1307 if (nse_work_required >= sizeof (GNUNET_HashCode) * 8)
1309 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1310 _("Invalid work requirement for NSE service. Exiting.\n"));
1311 GNUNET_SCHEDULER_shutdown ();
1317 GNUNET_CONFIGURATION_get_value_filename (cfg,
1318 "GNUNETD", "HOSTKEY", &keyfile))
1320 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1322 ("NSE service is lacking key configuration settings. Exiting.\n"));
1323 GNUNET_SCHEDULER_shutdown ();
1326 my_private_key = GNUNET_CRYPTO_rsa_key_create_from_file (keyfile);
1327 GNUNET_free (keyfile);
1328 if (my_private_key == NULL)
1330 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1331 _("NSE service could not access hostkey. Exiting.\n"));
1332 GNUNET_SCHEDULER_shutdown ();
1335 GNUNET_CRYPTO_rsa_key_get_public (my_private_key, &my_public_key);
1336 GNUNET_CRYPTO_hash (&my_public_key, sizeof (my_public_key),
1337 &my_identity.hashPubKey);
1339 GNUNET_CONFIGURATION_get_value_filename (cfg, "NSE", "PROOFFILE", &proof))
1341 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1343 ("NSE service is lacking key configuration settings. Exiting.\n"));
1344 if (my_private_key != NULL)
1346 GNUNET_CRYPTO_rsa_key_free (my_private_key);
1347 my_private_key = NULL;
1349 GNUNET_SCHEDULER_shutdown ();
1352 if ((GNUNET_YES != GNUNET_DISK_file_test (proof)) ||
1353 (sizeof (my_proof) !=
1354 GNUNET_DISK_fn_read (proof, &my_proof, sizeof (my_proof))))
1356 GNUNET_free (proof);
1358 GNUNET_SCHEDULER_add_with_priority (GNUNET_SCHEDULER_PRIORITY_IDLE,
1361 peers = GNUNET_CONTAINER_multihashmap_create (128);
1362 GNUNET_SERVER_add_handlers (server, handlers);
1363 nc = GNUNET_SERVER_notification_context_create (server, 1);
1364 /* Connect to core service and register core handlers */
1365 coreAPI = GNUNET_CORE_connect (cfg, /* Main configuration */
1366 CORE_QUEUE_SIZE, /* queue size */
1367 NULL, /* Closure passed to functions */
1368 &core_init, /* Call core_init once connected */
1369 &handle_core_connect, /* Handle connects */
1370 &handle_core_disconnect, /* Handle disconnects */
1371 NULL, /* Do we care about "status" updates? */
1372 NULL, /* Don't want notified about all incoming messages */
1373 GNUNET_NO, /* For header only inbound notification */
1374 NULL, /* Don't want notified about all outbound messages */
1375 GNUNET_NO, /* For header only outbound notification */
1376 core_handlers); /* Register these handlers */
1377 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
1378 &shutdown_task, NULL);
1379 #if ENABLE_HISTOGRAM
1381 GNUNET_CONFIGURATION_get_value_filename (cfg, "NSE", "HISTOGRAM", &proof))
1383 wh = GNUNET_BIO_write_open (proof);
1384 GNUNET_free (proof);
1387 if (coreAPI == NULL)
1389 GNUNET_SCHEDULER_shutdown ();
1392 stats = GNUNET_STATISTICS_create ("nse", cfg);
1397 * The main function for the statistics service.
1399 * @param argc number of arguments from the command line
1400 * @param argv command line arguments
1401 * @return 0 ok, 1 on error
1404 main (int argc, char *const *argv)
1406 return (GNUNET_OK == GNUNET_SERVICE_run (argc, argv,
1408 GNUNET_SERVICE_OPTION_NONE, &run,
1412 /* end of gnunet-service-nse.c */