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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"
47 #if ENABLE_NSE_HISTOGRAM
48 #include "gnunet_testbed_logger_service.h"
55 * Should messages be delayed randomly? This option should be set to
56 * #GNUNET_NO only for experiments, not in production.
58 #define USE_RANDOM_DELAYS GNUNET_YES
61 * Generate extensive debug-level log messages?
63 #define DEBUG_NSE GNUNET_NO
66 * Over how many values do we calculate the weighted average?
68 #define HISTORY_SIZE 64
71 * Message priority to use.
73 #define NSE_PRIORITY GNUNET_CORE_PRIO_CRITICAL_CONTROL
76 #define log2(a) (log(a)/log(2))
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;
94 #if ENABLE_NSE_HISTOGRAM
97 * Handle to test if testbed logger service is running or not
99 struct GNUNET_CLIENT_TestHandle *logger_test;
102 * Handle for writing when we received messages to disk.
104 static struct GNUNET_TESTBED_LOGGER_Handle *lh;
107 * Handle for writing message received timestamp information to disk.
109 static struct GNUNET_BIO_WriteHandle *histogram;
115 * Per-peer information.
121 * Core handle for sending messages to this peer.
123 struct GNUNET_CORE_TransmitHandle *th;
126 * What is the identity of the peer?
128 struct GNUNET_PeerIdentity id;
131 * Task scheduled to send message to this peer.
133 struct GNUNET_SCHEDULER_Task * transmit_task;
136 * Did we receive or send a message about the previous round
137 * to this peer yet? #GNUNET_YES if the previous round has
138 * been taken care of.
142 #if ENABLE_NSE_HISTOGRAM
145 * Amount of messages received from this peer on this round.
147 unsigned int received_messages;
150 * Amount of messages transmitted to this peer on this round.
152 unsigned int transmitted_messages;
155 * Which size did we tell the peer the network is?
157 unsigned int last_transmitted_size;
164 GNUNET_NETWORK_STRUCT_BEGIN
167 * Network size estimate reply; sent when "this"
168 * peer's timer has run out before receiving a
169 * valid reply from another peer.
171 struct GNUNET_NSE_FloodMessage
174 * Type: #GNUNET_MESSAGE_TYPE_NSE_P2P_FLOOD
176 struct GNUNET_MessageHeader header;
179 * Number of hops this message has taken so far.
181 uint32_t hop_count GNUNET_PACKED;
186 struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
189 * The current timestamp value (which all
190 * peers should agree on).
192 struct GNUNET_TIME_AbsoluteNBO timestamp;
195 * Number of matching bits between the hash
196 * of timestamp and the initiator's public
199 uint32_t matching_bits GNUNET_PACKED;
202 * Public key of the originator.
204 struct GNUNET_PeerIdentity origin;
207 * Proof of work, causing leading zeros when hashed with pkey.
209 uint64_t proof_of_work GNUNET_PACKED;
212 * Signature (over range specified in purpose).
214 struct GNUNET_CRYPTO_EddsaSignature signature;
216 GNUNET_NETWORK_STRUCT_END
219 * Handle to our current configuration.
221 static const struct GNUNET_CONFIGURATION_Handle *cfg;
224 * Handle to the statistics service.
226 static struct GNUNET_STATISTICS_Handle *stats;
229 * Handle to the core service.
231 static struct GNUNET_CORE_Handle *core_api;
234 * Map of all connected peers.
236 static struct GNUNET_CONTAINER_MultiPeerMap *peers;
239 * The current network size estimate. Number of bits matching on
242 static double current_size_estimate;
245 * The standard deviation of the last #HISTORY_SIZE network
248 static double current_std_dev = NAN;
251 * Current hop counter estimate (estimate for network diameter).
253 static uint32_t hop_count_max;
256 * Message for the next round, if we got any.
258 static struct GNUNET_NSE_FloodMessage next_message;
261 * Array of recent size estimate messages.
263 static struct GNUNET_NSE_FloodMessage size_estimate_messages[HISTORY_SIZE];
266 * Index of most recent estimate.
268 static unsigned int estimate_index;
271 * Number of valid entries in the history.
273 static unsigned int estimate_count;
276 * Task scheduled to update our flood message for the next round.
278 static struct GNUNET_SCHEDULER_Task * flood_task;
281 * Task scheduled to compute our proof.
283 static struct GNUNET_SCHEDULER_Task * proof_task;
286 * Notification context, simplifies client broadcasts.
288 static struct GNUNET_SERVER_NotificationContext *nc;
291 * The next major time.
293 static struct GNUNET_TIME_Absolute next_timestamp;
296 * The current major time.
298 static struct GNUNET_TIME_Absolute current_timestamp;
301 * The private key of this peer.
303 static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
306 * The peer identity of this peer.
308 static struct GNUNET_PeerIdentity my_identity;
311 * Proof of work for this peer.
313 static uint64_t my_proof;
316 * Handle to this serivce's server.
318 static struct GNUNET_SERVER_Handle *srv;
322 * Initialize a message to clients with the current network
325 * @param em message to fill in
328 setup_estimate_message (struct GNUNET_NSE_ClientMessage *em)
340 /* Weighted incremental algorithm for stddev according to West (1979) */
352 for (i = 0; i < estimate_count; i++)
354 j = (estimate_index - i + HISTORY_SIZE) % HISTORY_SIZE;
355 val = htonl (size_estimate_messages[j].matching_bits);
356 weight = estimate_count + 1 - i;
358 temp = weight + sumweight;
360 r = q * weight / temp;
362 sum += sumweight * q * r;
365 if (estimate_count > 0)
366 variance = (sum / sumweight) * estimate_count / (estimate_count - 1.0);
368 /* trivial version for debugging */
371 /* non-weighted trivial version */
377 for (i = 0; i < estimate_count; i++)
379 j = (estimate_index - i + HISTORY_SIZE) % HISTORY_SIZE;
380 val = htonl (size_estimate_messages[j].matching_bits);
384 if (0 != estimate_count)
386 mean = sum / estimate_count;
387 variance = (vsq - mean * sum) / (estimate_count - 1.0); // terrible for numerical stability...
391 std_dev = sqrt (variance);
393 std_dev = variance; /* must be infinity due to estimate_count == 0 */
394 current_std_dev = std_dev;
395 current_size_estimate = mean;
397 em->header.size = htons (sizeof (struct GNUNET_NSE_ClientMessage));
398 em->header.type = htons (GNUNET_MESSAGE_TYPE_NSE_ESTIMATE);
399 em->reserved = htonl (0);
400 em->timestamp = GNUNET_TIME_absolute_hton (GNUNET_TIME_absolute_get ());
401 double se = mean - 0.332747;
402 j = GNUNET_CONTAINER_multipeermap_size (peers);
404 j = 1; /* Avoid log2(0); can only happen if CORE didn't report
405 connection to self yet */
407 em->size_estimate = GNUNET_hton_double (GNUNET_MAX (se,
409 em->std_deviation = GNUNET_hton_double (std_dev);
410 GNUNET_STATISTICS_set (stats,
411 "# nodes in the network (estimate)",
412 (uint64_t) pow (2, GNUNET_MAX (se,
419 * Handler for START message from client, triggers an
420 * immediate current network estimate notification.
421 * Also, we remember the client for updates upon future
422 * estimate measurements.
425 * @param client who sent the message
426 * @param message the message received
429 handle_start_message (void *cls,
430 struct GNUNET_SERVER_Client *client,
431 const struct GNUNET_MessageHeader *message)
433 struct GNUNET_NSE_ClientMessage em;
435 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
436 "Received START message from client\n");
437 GNUNET_SERVER_notification_context_add (nc, client);
438 setup_estimate_message (&em);
439 GNUNET_SERVER_notification_context_unicast (nc, client, &em.header,
441 GNUNET_SERVER_receive_done (client, GNUNET_OK);
446 * How long should we delay a message to go the given number of
449 * @param matching_bits number of matching bits to consider
452 get_matching_bits_delay (uint32_t matching_bits)
454 /* Calculated as: S + f/2 - (f / pi) * (atan(x - p')) */
455 // S is next_timestamp (ignored in return value)
456 // f is frequency (gnunet_nse_interval)
457 // x is matching_bits
458 // p' is current_size_estimate
459 return ((double) gnunet_nse_interval.rel_value_us / (double) 2.0) -
460 ((gnunet_nse_interval.rel_value_us / M_PI) *
461 atan (matching_bits - current_size_estimate));
466 * What delay randomization should we apply for a given number of matching bits?
468 * @param matching_bits number of matching bits
469 * @return random delay to apply
471 static struct GNUNET_TIME_Relative
472 get_delay_randomization (uint32_t matching_bits)
474 #if USE_RANDOM_DELAYS
475 struct GNUNET_TIME_Relative ret;
479 d = get_matching_bits_delay (matching_bits);
480 i = (uint32_t) (d / (double) (hop_count_max + 1));
481 ret.rel_value_us = i;
482 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
483 "Randomizing flood using latencies up to %s\n",
484 GNUNET_STRINGS_relative_time_to_string (ret,
486 ret.rel_value_us = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, i + 1);
489 return GNUNET_TIME_UNIT_ZERO;
495 * Calculate the 'proof-of-work' hash (an expensive hash).
497 * @param buf data to hash
498 * @param buf_len number of bytes in @a buf
499 * @param result where to write the resulting hash
502 pow_hash (const void *buf,
504 struct GNUNET_HashCode *result)
507 gcry_kdf_derive (buf, buf_len,
510 "gnunet-proof-of-work", strlen ("gnunet-proof-of-work"),
511 2 /* iterations; keep cost of individual op small */,
512 sizeof (struct GNUNET_HashCode), result));
517 * Get the number of matching bits that the given timestamp has to the given peer ID.
519 * @param timestamp time to generate key
520 * @param id peer identity to compare with
521 * @return number of matching bits
524 get_matching_bits (struct GNUNET_TIME_Absolute timestamp,
525 const struct GNUNET_PeerIdentity *id)
527 struct GNUNET_HashCode timestamp_hash;
528 struct GNUNET_HashCode pid_hash;
530 GNUNET_CRYPTO_hash (×tamp.abs_value_us,
531 sizeof (timestamp.abs_value_us),
533 GNUNET_CRYPTO_hash (id,
534 sizeof (struct GNUNET_PeerIdentity),
536 return GNUNET_CRYPTO_hash_matching_bits (×tamp_hash,
542 * Get the transmission delay that should be applied for a
545 * @param round_offset -1 for the previous round (random delay between 0 and 50ms)
546 * 0 for the current round (based on our proximity to time key)
547 * @return delay that should be applied
549 static struct GNUNET_TIME_Relative
550 get_transmit_delay (int round_offset)
552 struct GNUNET_TIME_Relative ret;
553 struct GNUNET_TIME_Absolute tgt;
555 uint32_t matching_bits;
557 switch (round_offset)
560 /* previous round is randomized between 0 and 50 ms */
561 #if USE_RANDOM_DELAYS
562 ret.rel_value_us = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK, 50);
564 ret = GNUNET_TIME_UNIT_ZERO;
566 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
567 "Transmitting previous round behind schedule in %s\n",
568 GNUNET_STRINGS_relative_time_to_string (ret, GNUNET_YES));
571 /* current round is based on best-known matching_bits */
573 ntohl (size_estimate_messages[estimate_index].matching_bits);
574 dist_delay = get_matching_bits_delay (matching_bits);
575 dist_delay += get_delay_randomization (matching_bits).rel_value_us;
576 ret.rel_value_us = (uint64_t) dist_delay;
577 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
578 "For round %s, delay for %u matching bits is %s\n",
579 GNUNET_STRINGS_absolute_time_to_string (current_timestamp),
580 (unsigned int) matching_bits,
581 GNUNET_STRINGS_relative_time_to_string (ret,
583 /* now consider round start time and add delay to it */
584 tgt = GNUNET_TIME_absolute_add (current_timestamp, ret);
585 return GNUNET_TIME_absolute_get_remaining (tgt);
588 return GNUNET_TIME_UNIT_FOREVER_REL;
593 * Task that triggers a NSE P2P transmission.
595 * @param cls the `struct NSEPeerEntry *`
598 transmit_task_cb (void *cls);
602 * Called when core is ready to send a message we asked for
603 * out to the destination.
605 * @param cls closure with the `struct NSEPeerEntry *`
606 * @param size number of bytes available in @a buf
607 * @param buf where the callee should write the message
608 * @return number of bytes written to @a buf
611 transmit_ready (void *cls,
615 struct NSEPeerEntry *peer_entry = cls;
618 peer_entry->th = NULL;
621 /* client disconnected */
624 GNUNET_assert (size >= sizeof (struct GNUNET_NSE_FloodMessage));
625 idx = estimate_index;
626 if (GNUNET_NO == peer_entry->previous_round)
628 idx = (idx + HISTORY_SIZE - 1) % HISTORY_SIZE;
629 peer_entry->previous_round = GNUNET_YES;
630 peer_entry->transmit_task =
631 GNUNET_SCHEDULER_add_delayed (get_transmit_delay (0),
635 if ((0 == ntohl (size_estimate_messages[idx].hop_count)) &&
636 (NULL != proof_task))
638 GNUNET_STATISTICS_update (stats,
639 "# flood messages not generated (no proof yet)",
643 if (0 == ntohs (size_estimate_messages[idx].header.size))
645 GNUNET_STATISTICS_update (stats,
646 "# flood messages not generated (lack of history)",
650 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
651 "In round %s, sending to `%s' estimate with %u bits\n",
652 GNUNET_STRINGS_absolute_time_to_string (GNUNET_TIME_absolute_ntoh (size_estimate_messages[idx].timestamp)),
653 GNUNET_i2s (&peer_entry->id),
654 (unsigned int) ntohl (size_estimate_messages[idx].matching_bits));
655 if (ntohl (size_estimate_messages[idx].hop_count) == 0)
656 GNUNET_STATISTICS_update (stats, "# flood messages started", 1, GNUNET_NO);
657 GNUNET_STATISTICS_update (stats, "# flood messages transmitted", 1,
659 #if ENABLE_NSE_HISTOGRAM
660 peer_entry->transmitted_messages++;
661 peer_entry->last_transmitted_size =
662 ntohl(size_estimate_messages[idx].matching_bits);
664 memcpy (buf, &size_estimate_messages[idx],
665 sizeof (struct GNUNET_NSE_FloodMessage));
666 return sizeof (struct GNUNET_NSE_FloodMessage);
671 * Task that triggers a NSE P2P transmission.
673 * @param cls the `struct NSEPeerEntry *`
676 transmit_task_cb (void *cls)
678 struct NSEPeerEntry *peer_entry = cls;
680 peer_entry->transmit_task = NULL;
682 GNUNET_assert (NULL == peer_entry->th);
684 GNUNET_CORE_notify_transmit_ready (core_api, GNUNET_NO,
686 GNUNET_TIME_UNIT_FOREVER_REL,
689 GNUNET_NSE_FloodMessage),
690 &transmit_ready, peer_entry);
695 * We've sent on our flood message or one that we received which was
696 * validated and closer than ours. Update the global list of recent
697 * messages and the average. Also re-broadcast the message to any
701 update_network_size_estimate ()
703 struct GNUNET_NSE_ClientMessage em;
705 setup_estimate_message (&em);
706 GNUNET_SERVER_notification_context_broadcast (nc,
713 * Setup a flood message in our history array at the given
714 * slot offset for the given timestamp.
716 * @param slot index to use
717 * @param ts timestamp to use
720 setup_flood_message (unsigned int slot,
721 struct GNUNET_TIME_Absolute ts)
723 struct GNUNET_NSE_FloodMessage *fm;
724 uint32_t matching_bits;
726 matching_bits = get_matching_bits (ts, &my_identity);
727 fm = &size_estimate_messages[slot];
728 fm->header.size = htons (sizeof (struct GNUNET_NSE_FloodMessage));
729 fm->header.type = htons (GNUNET_MESSAGE_TYPE_NSE_P2P_FLOOD);
730 fm->hop_count = htonl (0);
731 fm->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_NSE_SEND);
733 htonl (sizeof (struct GNUNET_NSE_FloodMessage) -
734 sizeof (struct GNUNET_MessageHeader) - sizeof (uint32_t) -
735 sizeof (struct GNUNET_CRYPTO_EddsaSignature));
736 fm->matching_bits = htonl (matching_bits);
737 fm->timestamp = GNUNET_TIME_absolute_hton (ts);
738 fm->origin = my_identity;
739 fm->proof_of_work = my_proof;
740 if (nse_work_required > 0)
741 GNUNET_assert (GNUNET_OK ==
742 GNUNET_CRYPTO_eddsa_sign (my_private_key, &fm->purpose,
745 memset (&fm->signature, 0, sizeof (fm->signature));
750 * Schedule transmission for the given peer for the current round based
751 * on what we know about the desired delay.
754 * @param key hash of peer identity
755 * @param value the `struct NSEPeerEntry`
756 * @return #GNUNET_OK (continue to iterate)
759 schedule_current_round (void *cls,
760 const struct GNUNET_PeerIdentity * key,
763 struct NSEPeerEntry *peer_entry = value;
764 struct GNUNET_TIME_Relative delay;
766 if (NULL != peer_entry->th)
768 peer_entry->previous_round = GNUNET_NO;
771 if (NULL != peer_entry->transmit_task)
773 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
774 peer_entry->previous_round = GNUNET_NO;
776 #if ENABLE_NSE_HISTOGRAM
777 if (peer_entry->received_messages > 1)
778 GNUNET_STATISTICS_update(stats, "# extra messages",
779 peer_entry->received_messages - 1, GNUNET_NO);
780 peer_entry->transmitted_messages = 0;
781 peer_entry->last_transmitted_size = 0;
782 peer_entry->received_messages = 0;
785 get_transmit_delay ((peer_entry->previous_round == GNUNET_NO) ? -1 : 0);
786 peer_entry->transmit_task =
787 GNUNET_SCHEDULER_add_delayed (delay,
795 * Update our flood message to be sent (and our timestamps).
800 update_flood_message (void *cls)
802 struct GNUNET_TIME_Relative offset;
806 offset = GNUNET_TIME_absolute_get_remaining (next_timestamp);
807 if (0 != offset.rel_value_us)
809 /* somehow run early, delay more */
811 GNUNET_SCHEDULER_add_delayed (offset,
812 &update_flood_message, NULL);
815 estimate_index = (estimate_index + 1) % HISTORY_SIZE;
816 if (estimate_count < HISTORY_SIZE)
818 current_timestamp = next_timestamp;
820 GNUNET_TIME_absolute_add (current_timestamp, gnunet_nse_interval);
821 if ((current_timestamp.abs_value_us ==
822 GNUNET_TIME_absolute_ntoh (next_message.timestamp).abs_value_us) &&
823 (get_matching_bits (current_timestamp, &my_identity) <
824 ntohl(next_message.matching_bits)))
826 /* we received a message for this round way early, use it! */
827 size_estimate_messages[estimate_index] = next_message;
828 size_estimate_messages[estimate_index].hop_count =
829 htonl (1 + ntohl (next_message.hop_count));
832 setup_flood_message (estimate_index, current_timestamp);
833 next_message.matching_bits = htonl (0); /* reset for 'next' round */
835 for (i = 0; i < HISTORY_SIZE; i++)
837 GNUNET_MAX (ntohl (size_estimate_messages[i].hop_count), hop_count_max);
838 GNUNET_CONTAINER_multipeermap_iterate (peers,
839 &schedule_current_round,
842 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_absolute_get_remaining
844 &update_flood_message,
850 * Count the leading zeroes in hash.
852 * @param hash to count leading zeros in
853 * @return the number of leading zero bits.
856 count_leading_zeroes (const struct GNUNET_HashCode *hash)
858 unsigned int hash_count;
861 while (0 == GNUNET_CRYPTO_hash_get_bit (hash, hash_count))
868 * Check whether the given public key and integer are a valid proof of
871 * @param pkey the public key
872 * @param val the integer
873 * @return #GNUNET_YES if valid, #GNUNET_NO if not
876 check_proof_of_work (const struct GNUNET_CRYPTO_EddsaPublicKey *pkey,
879 char buf[sizeof (struct GNUNET_CRYPTO_EddsaPublicKey) +
880 sizeof (val)] GNUNET_ALIGN;
881 struct GNUNET_HashCode result;
883 memcpy (buf, &val, sizeof (val));
884 memcpy (&buf[sizeof (val)], pkey,
885 sizeof (struct GNUNET_CRYPTO_EddsaPublicKey));
886 pow_hash (buf, sizeof (buf), &result);
887 return (count_leading_zeroes (&result) >=
888 nse_work_required) ? GNUNET_YES : GNUNET_NO;
893 * Write our current proof to disk.
901 GNUNET_CONFIGURATION_get_value_filename (cfg, "NSE", "PROOFFILE", &proof))
903 if (sizeof (my_proof) !=
904 GNUNET_DISK_fn_write (proof, &my_proof, sizeof (my_proof),
905 GNUNET_DISK_PERM_USER_READ |
906 GNUNET_DISK_PERM_USER_WRITE))
907 GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "write", proof);
914 * Find our proof of work.
916 * @param cls closure (unused)
919 find_proof (void *cls)
921 #define ROUND_SIZE 10
923 char buf[sizeof (struct GNUNET_CRYPTO_EddsaPublicKey) +
924 sizeof (uint64_t)] GNUNET_ALIGN;
925 struct GNUNET_HashCode result;
929 memcpy (&buf[sizeof (uint64_t)], &my_identity,
930 sizeof (struct GNUNET_PeerIdentity));
933 while ((counter != UINT64_MAX) && (i < ROUND_SIZE))
935 memcpy (buf, &counter, sizeof (uint64_t));
936 pow_hash (buf, sizeof (buf), &result);
937 if (nse_work_required <= count_leading_zeroes (&result))
940 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Proof of work found: %llu!\n",
941 (unsigned long long) GNUNET_ntohll (counter));
943 setup_flood_message (estimate_index, current_timestamp);
949 if (my_proof / (100 * ROUND_SIZE) < counter / (100 * ROUND_SIZE))
951 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
952 "Testing proofs currently at %llu\n",
953 (unsigned long long) counter);
954 /* remember progress every 100 rounds */
963 GNUNET_SCHEDULER_add_delayed_with_priority (proof_find_delay,
964 GNUNET_SCHEDULER_PRIORITY_IDLE,
970 * An incoming flood message has been received which claims
971 * to have more bits matching than any we know in this time
972 * period. Verify the signature and/or proof of work.
974 * @param incoming_flood the message to verify
975 * @return #GNUNET_YES if the message is verified
976 * #GNUNET_NO if the key/signature don't verify
979 verify_message_crypto (const struct GNUNET_NSE_FloodMessage *incoming_flood)
982 check_proof_of_work (&incoming_flood->origin.public_key,
983 incoming_flood->proof_of_work))
985 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
986 "Proof of work invalid: %llu!\n",
988 GNUNET_ntohll (incoming_flood->proof_of_work));
992 if ((nse_work_required > 0) &&
994 GNUNET_CRYPTO_eddsa_verify (GNUNET_SIGNATURE_PURPOSE_NSE_SEND,
995 &incoming_flood->purpose,
996 &incoming_flood->signature,
997 &incoming_flood->origin.public_key)))
1007 * Update transmissions for the given peer for the current round based
1008 * on updated proximity information.
1010 * @param cls peer entry to exclude from updates
1011 * @param key hash of peer identity
1012 * @param value the `struct NSEPeerEntry *` of a peer to transmit to
1013 * @return #GNUNET_OK (continue to iterate)
1016 update_flood_times (void *cls,
1017 const struct GNUNET_PeerIdentity *key,
1020 struct NSEPeerEntry *exclude = cls;
1021 struct NSEPeerEntry *peer_entry = value;
1022 struct GNUNET_TIME_Relative delay;
1024 if (NULL != peer_entry->th)
1025 return GNUNET_OK; /* already active */
1026 if (peer_entry == exclude)
1027 return GNUNET_OK; /* trigger of the update */
1028 if (peer_entry->previous_round == GNUNET_NO)
1030 /* still stuck in previous round, no point to update, check that
1031 * we are active here though... */
1032 if ( (NULL == peer_entry->transmit_task) &&
1033 (NULL == peer_entry->th) )
1039 if (NULL != peer_entry->transmit_task)
1041 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
1042 peer_entry->transmit_task = NULL;
1044 delay = get_transmit_delay (0);
1045 peer_entry->transmit_task =
1046 GNUNET_SCHEDULER_add_delayed (delay,
1047 &transmit_task_cb, peer_entry);
1053 * Core handler for size estimate flooding messages.
1055 * @param cls closure unused
1056 * @param message message
1057 * @param peer peer identity this message is from (ignored)
1060 handle_p2p_size_estimate (void *cls,
1061 const struct GNUNET_PeerIdentity *peer,
1062 const struct GNUNET_MessageHeader *message)
1064 const struct GNUNET_NSE_FloodMessage *incoming_flood;
1065 struct GNUNET_TIME_Absolute ts;
1066 struct NSEPeerEntry *peer_entry;
1067 uint32_t matching_bits;
1070 #if ENABLE_NSE_HISTOGRAM
1074 t = GNUNET_TIME_absolute_get().abs_value_us;
1076 GNUNET_TESTBED_LOGGER_write (lh, &t, sizeof (uint64_t));
1077 if (NULL != histogram)
1078 GNUNET_BIO_write_int64 (histogram, t);
1081 incoming_flood = (const struct GNUNET_NSE_FloodMessage *) message;
1082 GNUNET_STATISTICS_update (stats, "# flood messages received", 1, GNUNET_NO);
1083 matching_bits = ntohl (incoming_flood->matching_bits);
1088 struct GNUNET_PeerIdentity os;
1090 GNUNET_snprintf (origin,
1093 GNUNET_i2s (&incoming_flood->origin));
1094 GNUNET_snprintf (pred,
1098 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1099 "Flood at %s from `%s' via `%s' at `%s' with bits %u\n",
1100 GNUNET_STRINGS_absolute_time_to_string (GNUNET_TIME_absolute_ntoh (incoming_flood->timestamp)),
1101 origin, pred, GNUNET_i2s (&my_identity),
1102 (unsigned int) matching_bits);
1106 peer_entry = GNUNET_CONTAINER_multipeermap_get (peers, peer);
1107 if (NULL == peer_entry)
1112 #if ENABLE_NSE_HISTOGRAM
1113 peer_entry->received_messages++;
1114 if (peer_entry->transmitted_messages > 0 &&
1115 peer_entry->last_transmitted_size >= matching_bits)
1116 GNUNET_STATISTICS_update(stats, "# cross messages", 1, GNUNET_NO);
1119 ts = GNUNET_TIME_absolute_ntoh (incoming_flood->timestamp);
1120 if (ts.abs_value_us == current_timestamp.abs_value_us)
1121 idx = estimate_index;
1122 else if (ts.abs_value_us ==
1123 current_timestamp.abs_value_us - gnunet_nse_interval.rel_value_us)
1124 idx = (estimate_index + HISTORY_SIZE - 1) % HISTORY_SIZE;
1125 else if (ts.abs_value_us == next_timestamp.abs_value_us)
1127 if (matching_bits <= ntohl (next_message.matching_bits))
1128 return GNUNET_OK; /* ignore, simply too early/late */
1129 if (GNUNET_YES != verify_message_crypto (incoming_flood))
1131 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1132 "Peer %s is likely ill-configured!\n",
1134 GNUNET_break_op (0);
1137 next_message = *incoming_flood;
1142 GNUNET_STATISTICS_update (stats,
1143 "# flood messages discarded (clock skew too large)",
1147 if (0 == (memcmp (peer, &my_identity, sizeof (struct GNUNET_PeerIdentity))))
1149 /* send to self, update our own estimate IF this also comes from us! */
1151 memcmp (&incoming_flood->origin,
1152 &my_identity, sizeof (my_identity)))
1153 update_network_size_estimate ();
1156 if (matching_bits == ntohl (size_estimate_messages[idx].matching_bits))
1158 /* Cancel transmission in the other direction, as this peer clearly has
1159 up-to-date information already. Even if we didn't talk to this peer in
1160 the previous round, we should no longer send it stale information as it
1161 told us about the current round! */
1162 peer_entry->previous_round = GNUNET_YES;
1163 if (idx != estimate_index)
1165 /* do not transmit information for the previous round to this peer
1166 anymore (but allow current round) */
1169 /* got up-to-date information for current round, cancel transmission to
1170 * this peer altogether */
1171 if (NULL != peer_entry->transmit_task)
1173 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
1174 peer_entry->transmit_task = NULL;
1176 if (NULL != peer_entry->th)
1178 GNUNET_CORE_notify_transmit_ready_cancel (peer_entry->th);
1179 peer_entry->th = NULL;
1183 if (matching_bits < ntohl (size_estimate_messages[idx].matching_bits))
1185 if ((idx < estimate_index) && (peer_entry->previous_round == GNUNET_YES)) {
1186 peer_entry->previous_round = GNUNET_NO;
1188 /* push back our result now, that peer is spreading bad information... */
1189 if (NULL == peer_entry->th)
1191 if (peer_entry->transmit_task != NULL)
1192 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
1193 peer_entry->transmit_task =
1194 GNUNET_SCHEDULER_add_now (&transmit_task_cb, peer_entry);
1196 /* Not closer than our most recent message, no need to do work here */
1197 GNUNET_STATISTICS_update (stats,
1198 "# flood messages ignored (had closer already)",
1202 if (GNUNET_YES != verify_message_crypto (incoming_flood))
1204 GNUNET_break_op (0);
1207 GNUNET_assert (matching_bits >
1208 ntohl (size_estimate_messages[idx].matching_bits));
1209 /* Cancel transmission in the other direction, as this peer clearly has
1210 * up-to-date information already.
1212 peer_entry->previous_round = GNUNET_YES;
1213 if (idx == estimate_index)
1215 /* cancel any activity for current round */
1216 if (peer_entry->transmit_task != NULL)
1218 GNUNET_SCHEDULER_cancel (peer_entry->transmit_task);
1219 peer_entry->transmit_task = NULL;
1221 if (peer_entry->th != NULL)
1223 GNUNET_CORE_notify_transmit_ready_cancel (peer_entry->th);
1224 peer_entry->th = NULL;
1227 size_estimate_messages[idx] = *incoming_flood;
1228 size_estimate_messages[idx].hop_count =
1229 htonl (ntohl (incoming_flood->hop_count) + 1);
1231 GNUNET_MAX (ntohl (incoming_flood->hop_count) + 1, hop_count_max);
1232 GNUNET_STATISTICS_set (stats,
1233 "# estimated network diameter",
1234 hop_count_max, GNUNET_NO);
1236 /* have a new, better size estimate, inform clients */
1237 update_network_size_estimate ();
1240 GNUNET_CONTAINER_multipeermap_iterate (peers, &update_flood_times,
1247 * Method called whenever a peer connects. Sets up the PeerEntry and
1248 * schedules the initial size info transmission to this peer.
1250 * @param cls closure
1251 * @param peer peer identity this notification is about
1254 handle_core_connect (void *cls,
1255 const struct GNUNET_PeerIdentity *peer)
1257 struct NSEPeerEntry *peer_entry;
1259 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1260 "Peer `%s' connected to us\n",
1262 peer_entry = GNUNET_new (struct NSEPeerEntry);
1263 peer_entry->id = *peer;
1264 GNUNET_assert (GNUNET_OK ==
1265 GNUNET_CONTAINER_multipeermap_put (peers,
1268 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
1269 peer_entry->transmit_task =
1270 GNUNET_SCHEDULER_add_delayed (get_transmit_delay (-1),
1273 GNUNET_STATISTICS_update (stats,
1274 "# peers connected",
1281 * Method called whenever a peer disconnects. Deletes the PeerEntry and cancels
1282 * any pending transmission requests to that peer.
1284 * @param cls closure
1285 * @param peer peer identity this notification is about
1288 handle_core_disconnect (void *cls,
1289 const struct GNUNET_PeerIdentity *peer)
1291 struct NSEPeerEntry *pos;
1293 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1294 "Peer `%s' disconnected from us\n",
1296 pos = GNUNET_CONTAINER_multipeermap_get (peers, peer);
1302 GNUNET_assert (GNUNET_YES ==
1303 GNUNET_CONTAINER_multipeermap_remove (peers, peer,
1305 if (pos->transmit_task != NULL) {
1306 GNUNET_SCHEDULER_cancel (pos->transmit_task);
1307 pos->transmit_task = NULL;
1309 if (NULL != pos->th)
1311 GNUNET_CORE_notify_transmit_ready_cancel (pos->th);
1315 GNUNET_STATISTICS_update (stats, "# peers connected", -1, GNUNET_NO);
1319 #if ENABLE_NSE_HISTOGRAM
1321 * Functions of this type are called to notify a successful transmission of the
1322 * message to the logger service
1325 * @param size the amount of data sent (ignored)
1328 flush_comp_cb (void *cls,
1331 GNUNET_TESTBED_LOGGER_disconnect (lh);
1338 * Task run during shutdown.
1343 shutdown_task (void *cls)
1345 if (NULL != flood_task)
1347 GNUNET_SCHEDULER_cancel (flood_task);
1350 if (NULL != proof_task)
1352 GNUNET_SCHEDULER_cancel (proof_task);
1354 write_proof (); /* remember progress */
1358 GNUNET_SERVER_notification_context_destroy (nc);
1361 if (NULL != core_api)
1363 GNUNET_CORE_disconnect (core_api);
1368 GNUNET_STATISTICS_destroy (stats, GNUNET_NO);
1373 GNUNET_CONTAINER_multipeermap_destroy (peers);
1376 if (NULL != my_private_key)
1378 GNUNET_free (my_private_key);
1379 my_private_key = NULL;
1381 #if ENABLE_NSE_HISTOGRAM
1382 if (NULL != logger_test)
1384 GNUNET_CLIENT_service_test_cancel (logger_test);
1389 struct GNUNET_TIME_Relative timeout;
1390 timeout = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30);
1391 GNUNET_TESTBED_LOGGER_flush (lh, timeout, &flush_comp_cb, NULL);
1393 if (NULL != histogram)
1395 GNUNET_BIO_write_close (histogram);
1403 * Called on core init/fail.
1405 * @param cls service closure
1406 * @param identity the public identity of this peer
1409 core_init (void *cls,
1410 const struct GNUNET_PeerIdentity *identity)
1412 struct GNUNET_TIME_Absolute now;
1413 struct GNUNET_TIME_Absolute prev_time;
1415 if (NULL == identity)
1417 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Connection to core FAILED!\n");
1418 GNUNET_SCHEDULER_shutdown ();
1422 memcmp (&my_identity, identity,
1423 sizeof (struct GNUNET_PeerIdentity)));
1424 now = GNUNET_TIME_absolute_get ();
1425 current_timestamp.abs_value_us =
1426 (now.abs_value_us / gnunet_nse_interval.rel_value_us) *
1427 gnunet_nse_interval.rel_value_us;
1429 GNUNET_TIME_absolute_add (current_timestamp, gnunet_nse_interval);
1430 estimate_index = HISTORY_SIZE - 1;
1432 if (GNUNET_YES == check_proof_of_work (&my_identity.public_key, my_proof))
1434 int idx = (estimate_index + HISTORY_SIZE - 1) % HISTORY_SIZE;
1435 prev_time.abs_value_us =
1436 current_timestamp.abs_value_us - gnunet_nse_interval.rel_value_us;
1437 setup_flood_message (idx, prev_time);
1438 setup_flood_message (estimate_index, current_timestamp);
1442 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_absolute_get_remaining
1444 &update_flood_message,
1448 #if ENABLE_NSE_HISTOGRAM
1450 * Function called with the status of the testbed logger service
1453 * @param status GNUNET_YES if the service is running,
1454 * GNUNET_NO if the service is not running
1455 * GNUNET_SYSERR if the configuration is invalid
1458 status_cb (void *cls, int status)
1461 if (GNUNET_YES != status)
1463 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Testbed logger not running\n");
1466 if (NULL == (lh = GNUNET_TESTBED_LOGGER_connect (cfg)))
1468 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1469 "Cannot connect to the testbed logger. Exiting.\n");
1470 GNUNET_SCHEDULER_shutdown ();
1477 * Handle network size estimate clients.
1479 * @param cls closure
1480 * @param server the initialized server
1481 * @param c configuration to use
1485 struct GNUNET_SERVER_Handle *server,
1486 const struct GNUNET_CONFIGURATION_Handle *c)
1488 static const struct GNUNET_SERVER_MessageHandler handlers[] = {
1489 {&handle_start_message, NULL, GNUNET_MESSAGE_TYPE_NSE_START,
1490 sizeof (struct GNUNET_MessageHeader)},
1493 static const struct GNUNET_CORE_MessageHandler core_handlers[] = {
1494 {&handle_p2p_size_estimate, GNUNET_MESSAGE_TYPE_NSE_P2P_FLOOD,
1495 sizeof (struct GNUNET_NSE_FloodMessage)},
1499 struct GNUNET_CRYPTO_EddsaPrivateKey *pk;
1504 GNUNET_CONFIGURATION_get_value_time (cfg, "NSE", "INTERVAL",
1505 &gnunet_nse_interval))
1507 GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
1509 GNUNET_SCHEDULER_shutdown ();
1513 GNUNET_CONFIGURATION_get_value_time (cfg, "NSE", "WORKDELAY",
1516 GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
1517 "NSE", "WORKDELAY");
1518 GNUNET_SCHEDULER_shutdown ();
1522 GNUNET_CONFIGURATION_get_value_number (cfg, "NSE", "WORKBITS",
1523 &nse_work_required))
1525 GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
1527 GNUNET_SCHEDULER_shutdown ();
1530 if (nse_work_required >= sizeof (struct GNUNET_HashCode) * 8)
1532 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
1535 _("Value is too large.\n"));
1536 GNUNET_SCHEDULER_shutdown ();
1540 #if ENABLE_NSE_HISTOGRAM
1542 char *histogram_dir;
1546 GNUNET_CONFIGURATION_get_value_filename (cfg, "NSE", "HISTOGRAM_DIR",
1549 GNUNET_assert (0 < GNUNET_asprintf (&histogram_fn, "%s/timestamps",
1551 GNUNET_free (histogram_dir);
1552 histogram = GNUNET_BIO_write_open (histogram_fn);
1553 GNUNET_free (histogram_fn);
1554 if (NULL == histogram)
1555 GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Unable to open histogram file\n");
1558 GNUNET_CLIENT_service_test ("testbed-logger", cfg,
1559 GNUNET_TIME_UNIT_SECONDS,
1565 GNUNET_SCHEDULER_add_shutdown (&shutdown_task,
1567 pk = GNUNET_CRYPTO_eddsa_key_create_from_configuration (cfg);
1568 GNUNET_assert (NULL != pk);
1569 my_private_key = pk;
1570 GNUNET_CRYPTO_eddsa_key_get_public (my_private_key,
1571 &my_identity.public_key);
1573 GNUNET_CONFIGURATION_get_value_filename (cfg, "NSE", "PROOFFILE", &proof))
1575 GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR, "NSE", "PROOFFILE");
1576 GNUNET_free (my_private_key);
1577 my_private_key = NULL;
1578 GNUNET_SCHEDULER_shutdown ();
1581 if ((GNUNET_YES != GNUNET_DISK_file_test (proof)) ||
1582 (sizeof (my_proof) !=
1583 GNUNET_DISK_fn_read (proof, &my_proof, sizeof (my_proof))))
1585 GNUNET_free (proof);
1587 GNUNET_SCHEDULER_add_with_priority (GNUNET_SCHEDULER_PRIORITY_IDLE,
1590 peers = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_NO);
1591 GNUNET_SERVER_add_handlers (srv, handlers);
1592 nc = GNUNET_SERVER_notification_context_create (srv, 1);
1593 /* Connect to core service and register core handlers */
1594 core_api = GNUNET_CORE_connect (cfg, /* Main configuration */
1595 NULL, /* Closure passed to functions */
1596 &core_init, /* Call core_init once connected */
1597 &handle_core_connect, /* Handle connects */
1598 &handle_core_disconnect, /* Handle disconnects */
1599 NULL, /* Don't want notified about all incoming messages */
1600 GNUNET_NO, /* For header only inbound notification */
1601 NULL, /* Don't want notified about all outbound messages */
1602 GNUNET_NO, /* For header only outbound notification */
1603 core_handlers); /* Register these handlers */
1604 if (NULL == core_api)
1606 GNUNET_SCHEDULER_shutdown ();
1609 stats = GNUNET_STATISTICS_create ("nse", cfg);
1614 * The main function for the network size estimation service.
1616 * @param argc number of arguments from the command line
1617 * @param argv command line arguments
1618 * @return 0 ok, 1 on error
1624 return (GNUNET_OK ==
1625 GNUNET_SERVICE_run (argc, argv, "nse", GNUNET_SERVICE_OPTION_NONE,
1626 &run, NULL)) ? 0 : 1;
1630 #if defined(LINUX) && defined(__GLIBC__)
1634 * MINIMIZE heap size (way below 128k) since this process doesn't need much.
1636 void __attribute__ ((constructor))
1637 GNUNET_ARM_memory_init ()
1639 mallopt (M_TRIM_THRESHOLD, 4 * 1024);
1640 mallopt (M_TOP_PAD, 1 * 1024);
1647 /* end of gnunet-service-nse.c */