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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22 * @file dht/gnunet-service-dht_neighbours.c
23 * @brief GNUnet DHT service's bucket and neighbour management code
24 * @author Christian Grothoff
25 * @author Nathan Evans
29 #include "gnunet_block_lib.h"
30 #include "gnunet_util_lib.h"
31 #include "gnunet_hello_lib.h"
32 #include "gnunet_constants.h"
33 #include "gnunet_protocols.h"
34 #include "gnunet_nse_service.h"
35 #include "gnunet_ats_service.h"
36 #include "gnunet_core_service.h"
37 #include "gnunet_datacache_lib.h"
38 #include "gnunet_transport_service.h"
39 #include "gnunet_hello_lib.h"
40 #include "gnunet_dht_service.h"
41 #include "gnunet_statistics_service.h"
42 #include "gnunet-service-dht.h"
43 #include "gnunet-service-dht_clients.h"
44 #include "gnunet-service-dht_datacache.h"
45 #include "gnunet-service-dht_hello.h"
46 #include "gnunet-service-dht_neighbours.h"
47 #include "gnunet-service-dht_nse.h"
48 #include "gnunet-service-dht_routing.h"
53 * How many buckets will we allow total.
55 #define MAX_BUCKETS sizeof (GNUNET_HashCode) * 8
58 * What is the maximum number of peers in a given bucket.
60 #define DEFAULT_BUCKET_SIZE 8
63 * Desired replication level for FIND PEER requests
65 #define FIND_PEER_REPLICATION_LEVEL 4
68 * Maximum allowed replication level for all requests.
70 #define MAXIMUM_REPLICATION_LEVEL 16
73 * How often to update our preference levels for peers in our routing tables.
75 #define DHT_DEFAULT_PREFERENCE_INTERVAL GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 2)
78 * How long at least to wait before sending another find peer request.
80 #define DHT_MINIMUM_FIND_PEER_INTERVAL GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 30)
83 * How long at most to wait before sending another find peer request.
85 #define DHT_MAXIMUM_FIND_PEER_INTERVAL GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 10)
88 * How long at most to wait for transmission of a GET request to another peer?
90 #define GET_TIMEOUT GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 2)
99 * Type: GNUNET_MESSAGE_TYPE_DHT_P2P_PUT
101 struct GNUNET_MessageHeader header;
106 uint32_t options GNUNET_PACKED;
111 uint32_t type GNUNET_PACKED;
116 uint32_t hop_count GNUNET_PACKED;
119 * Replication level for this message
121 uint32_t desired_replication_level GNUNET_PACKED;
124 * Length of the PUT path that follows (if tracked).
126 uint32_t put_path_length GNUNET_PACKED;
129 * When does the content expire?
131 struct GNUNET_TIME_AbsoluteNBO expiration_time;
134 * Bloomfilter (for peer identities) to stop circular routes
136 char bloomfilter[DHT_BLOOM_SIZE];
139 * The key we are storing under.
143 /* put path (if tracked) */
153 struct PeerResultMessage
156 * Type: GNUNET_MESSAGE_TYPE_DHT_P2P_RESULT
158 struct GNUNET_MessageHeader header;
163 uint32_t type GNUNET_PACKED;
166 * Length of the PUT path that follows (if tracked).
168 uint32_t put_path_length GNUNET_PACKED;
171 * Length of the GET path that follows (if tracked).
173 uint32_t get_path_length GNUNET_PACKED;
176 * When does the content expire?
178 struct GNUNET_TIME_AbsoluteNBO expiration_time;
181 * The key of the corresponding GET request.
185 /* put path (if tracked) */
187 /* get path (if tracked) */
197 struct PeerGetMessage
200 * Type: GNUNET_MESSAGE_TYPE_DHT_P2P_GET
202 struct GNUNET_MessageHeader header;
207 uint32_t options GNUNET_PACKED;
210 * Desired content type.
212 uint32_t type GNUNET_PACKED;
217 uint32_t hop_count GNUNET_PACKED;
220 * Desired replication level for this request.
222 uint32_t desired_replication_level GNUNET_PACKED;
225 * Size of the extended query.
227 uint32_t xquery_size;
230 * Bloomfilter mutator.
235 * Bloomfilter (for peer identities) to stop circular routes
237 char bloomfilter[DHT_BLOOM_SIZE];
240 * The key we are looking for.
246 /* result bloomfilter */
252 * Linked list of messages to send to a particular other peer.
254 struct P2PPendingMessage
257 * Pointer to next item in the list
259 struct P2PPendingMessage *next;
262 * Pointer to previous item in the list
264 struct P2PPendingMessage *prev;
267 * Message importance level. FIXME: used? useful?
269 unsigned int importance;
272 * When does this message time out?
274 struct GNUNET_TIME_Absolute timeout;
277 * Actual message to be sent, allocated at the end of the struct:
278 * // msg = (cast) &pm[1];
279 * // memcpy (&pm[1], data, len);
281 const struct GNUNET_MessageHeader *msg;
287 * Entry for a peer in a bucket.
292 * Next peer entry (DLL)
294 struct PeerInfo *next;
297 * Prev peer entry (DLL)
299 struct PeerInfo *prev;
302 * Count of outstanding messages for peer. FIXME: NEEDED?
303 * FIXME: bound queue size!?
305 unsigned int pending_count;
308 * Head of pending messages to be sent to this peer.
310 struct P2PPendingMessage *head;
313 * Tail of pending messages to be sent to this peer.
315 struct P2PPendingMessage *tail;
318 * Core handle for sending messages to this peer.
320 struct GNUNET_CORE_TransmitHandle *th;
323 * Preference update context
325 struct GNUNET_ATS_InformationRequestContext *info_ctx;
328 * Task for scheduling preference updates
330 GNUNET_SCHEDULER_TaskIdentifier preference_task;
333 * What is the identity of the peer?
335 struct GNUNET_PeerIdentity id;
339 * What is the average latency for replies received?
341 struct GNUNET_TIME_Relative latency;
344 * Transport level distance to peer.
346 unsigned int distance;
353 * Peers are grouped into buckets.
360 struct PeerInfo *head;
365 struct PeerInfo *tail;
368 * Number of peers in the bucket.
370 unsigned int peers_size;
375 * The lowest currently used bucket, initially 0 (for 0-bits matching bucket).
377 static unsigned int closest_bucket;
380 * How many peers have we added since we sent out our last
383 static unsigned int newly_found_peers;
386 * The buckets. Array of size MAX_BUCKET_SIZE. Offset 0 means 0 bits matching.
388 static struct PeerBucket k_buckets[MAX_BUCKETS];
391 * Hash map of all known peers, for easy removal from k_buckets on disconnect.
393 static struct GNUNET_CONTAINER_MultiHashMap *all_known_peers;
396 * Maximum size for each bucket.
398 static unsigned int bucket_size = DEFAULT_BUCKET_SIZE;
401 * Task that sends FIND PEER requests.
403 static GNUNET_SCHEDULER_TaskIdentifier find_peer_task;
406 * Identity of this peer.
408 static struct GNUNET_PeerIdentity my_identity;
413 static struct GNUNET_CORE_Handle *coreAPI;
418 static struct GNUNET_ATS_Handle *atsAPI;
423 * Find the optimal bucket for this key.
425 * @param hc the hashcode to compare our identity to
426 * @return the proper bucket index, or GNUNET_SYSERR
427 * on error (same hashcode)
430 find_bucket (const GNUNET_HashCode * hc)
434 bits = GNUNET_CRYPTO_hash_matching_bits (&my_identity.hashPubKey, hc);
435 if (bits == MAX_BUCKETS)
437 /* How can all bits match? Got my own ID? */
439 return GNUNET_SYSERR;
441 return MAX_BUCKETS - bits - 1;
446 * Let GNUnet core know that we like the given peer.
448 * @param cls the 'struct PeerInfo' of the peer
449 * @param tc scheduler context.
452 update_core_preference (void *cls,
453 const struct GNUNET_SCHEDULER_TaskContext *tc);
457 * Function called with statistics about the given peer.
460 * @param peer identifies the peer
461 * @param amount set to the amount that was actually reserved or unreserved;
462 * either the full requested amount or zero (no partial reservations)
463 * @param res_delay if the reservation could not be satisfied (amount was 0), how
464 * long should the client wait until re-trying?
467 update_core_preference_finish (void *cls,
468 const struct GNUNET_PeerIdentity *peer,
470 struct GNUNET_TIME_Relative res_delay)
472 struct PeerInfo *peer_info = cls;
474 peer_info->info_ctx = NULL;
475 peer_info->preference_task
476 = GNUNET_SCHEDULER_add_delayed (DHT_DEFAULT_PREFERENCE_INTERVAL,
477 &update_core_preference, peer_info);
482 * Let GNUnet core know that we like the given peer.
484 * @param cls the 'struct PeerInfo' of the peer
485 * @param tc scheduler context.
488 update_core_preference (void *cls,
489 const struct GNUNET_SCHEDULER_TaskContext *tc)
491 struct PeerInfo *peer = cls;
493 unsigned int matching;
496 peer->preference_task = GNUNET_SCHEDULER_NO_TASK;
497 if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
500 GNUNET_CRYPTO_hash_matching_bits (&my_identity.hashPubKey,
501 &peer->id.hashPubKey);
504 bucket = find_bucket (&peer->id.hashPubKey);
505 if (bucket == GNUNET_SYSERR)
509 GNUNET_assert (k_buckets[bucket].peers_size != 0);
510 preference = (1LL << matching) / k_buckets[bucket].peers_size;
514 peer->preference_task
515 = GNUNET_SCHEDULER_add_delayed (DHT_DEFAULT_PREFERENCE_INTERVAL,
516 &update_core_preference, peer);
519 GNUNET_STATISTICS_update (GDS_stats,
520 gettext_noop ("# Preference updates given to core"), 1,
523 GNUNET_ATS_peer_change_preference (atsAPI, &peer->id,
526 &update_core_preference_finish, peer);
531 * Closure for 'add_known_to_bloom'.
533 struct BloomConstructorContext
536 * Bloom filter under construction.
538 struct GNUNET_CONTAINER_BloomFilter *bloom;
548 * Add each of the peers we already know to the bloom filter of
549 * the request so that we don't get duplicate HELLOs.
551 * @param cls the 'struct BloomConstructorContext'.
552 * @param key peer identity to add to the bloom filter
553 * @param value value the peer information (unused)
554 * @return GNUNET_YES (we should continue to iterate)
557 add_known_to_bloom (void *cls, const GNUNET_HashCode * key, void *value)
559 struct BloomConstructorContext *ctx = cls;
562 GNUNET_BLOCK_mingle_hash (key, ctx->bf_mutator, &mh);
563 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
564 "Adding known peer (%s) to bloomfilter for FIND PEER with mutation %u\n",
567 GNUNET_CONTAINER_bloomfilter_add (ctx->bloom, &mh);
573 * Task to send a find peer message for our own peer identifier
574 * so that we can find the closest peers in the network to ourselves
575 * and attempt to connect to them.
577 * @param cls closure for this task
578 * @param tc the context under which the task is running
581 send_find_peer_message (void *cls,
582 const struct GNUNET_SCHEDULER_TaskContext *tc)
584 struct GNUNET_TIME_Relative next_send_time;
585 struct BloomConstructorContext bcc;
586 struct GNUNET_CONTAINER_BloomFilter *peer_bf;
588 find_peer_task = GNUNET_SCHEDULER_NO_TASK;
589 if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
591 if (newly_found_peers > bucket_size)
593 /* If we are finding many peers already, no need to send out our request right now! */
594 find_peer_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
595 &send_find_peer_message, NULL);
596 newly_found_peers = 0;
599 bcc.bf_mutator = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, UINT32_MAX);
601 GNUNET_CONTAINER_bloomfilter_init (NULL, DHT_BLOOM_SIZE, GNUNET_CONSTANTS_BLOOMFILTER_K);
602 GNUNET_CONTAINER_multihashmap_iterate (all_known_peers,
605 GNUNET_STATISTICS_update (GDS_stats,
606 gettext_noop ("# FIND PEER messages initiated"), 1,
608 peer_bf = GNUNET_CONTAINER_bloomfilter_init (NULL,
610 GNUNET_CONSTANTS_BLOOMFILTER_K);
611 // FIXME: pass priority!?
612 GDS_NEIGHBOURS_handle_get (GNUNET_BLOCK_TYPE_DHT_HELLO,
613 GNUNET_DHT_RO_FIND_PEER,
614 FIND_PEER_REPLICATION_LEVEL,
616 &my_identity.hashPubKey,
618 bcc.bloom, bcc.bf_mutator,
620 GNUNET_CONTAINER_bloomfilter_free (peer_bf);
621 GNUNET_CONTAINER_bloomfilter_free (bcc.bloom);
622 /* schedule next round */
623 next_send_time.rel_value =
624 DHT_MINIMUM_FIND_PEER_INTERVAL.rel_value +
625 GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK,
626 DHT_MAXIMUM_FIND_PEER_INTERVAL.rel_value / (newly_found_peers+1));
627 newly_found_peers = 0;
628 find_peer_task = GNUNET_SCHEDULER_add_delayed (next_send_time,
629 &send_find_peer_message,
635 * Method called whenever a peer connects.
638 * @param peer peer identity this notification is about
639 * @param atsi performance data
642 handle_core_connect (void *cls, const struct GNUNET_PeerIdentity *peer,
643 const struct GNUNET_TRANSPORT_ATS_Information *atsi)
645 struct PeerInfo *ret;
648 /* Check for connect to self message */
649 if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
651 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
652 "Connected %s to %s\n",
653 GNUNET_i2s (&my_identity),
654 GNUNET_h2s (&peer->hashPubKey));
656 GNUNET_CONTAINER_multihashmap_contains (all_known_peers,
662 GNUNET_STATISTICS_update (GDS_stats,
663 gettext_noop ("# Peers connected"), 1,
665 peer_bucket = find_bucket (&peer->hashPubKey);
666 GNUNET_assert ( (peer_bucket >= 0) && (peer_bucket < MAX_BUCKETS) );
667 ret = GNUNET_malloc (sizeof (struct PeerInfo));
669 ret->latency = latency;
670 ret->distance = distance;
673 GNUNET_CONTAINER_DLL_insert_tail (k_buckets[peer_bucket].head,
674 k_buckets[peer_bucket].tail, ret);
675 k_buckets[peer_bucket].peers_size++;
676 closest_bucket = GNUNET_MAX (closest_bucket,
678 if ( (peer_bucket > 0) &&
679 (k_buckets[peer_bucket].peers_size <= bucket_size) )
681 ret->preference_task = GNUNET_SCHEDULER_add_now (&update_core_preference, ret);
684 GNUNET_assert (GNUNET_OK ==
685 GNUNET_CONTAINER_multihashmap_put (all_known_peers,
686 &peer->hashPubKey, ret,
687 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
688 if (1 == GNUNET_CONTAINER_multihashmap_size (all_known_peers))
690 /* got a first connection, good time to start with FIND PEER requests... */
691 find_peer_task = GNUNET_SCHEDULER_add_now (&send_find_peer_message,
698 * Method called whenever a peer disconnects.
701 * @param peer peer identity this notification is about
704 handle_core_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer)
706 struct PeerInfo *to_remove;
708 struct P2PPendingMessage *pos;
709 unsigned int discarded;
711 /* Check for disconnect from self message */
712 if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
714 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
715 "Disconnected %s from %s\n",
716 GNUNET_i2s (&my_identity),
717 GNUNET_h2s (&peer->hashPubKey));
719 GNUNET_CONTAINER_multihashmap_get (all_known_peers, &peer->hashPubKey);
720 if (NULL == to_remove)
725 GNUNET_STATISTICS_update (GDS_stats,
726 gettext_noop ("# Peers connected"), -1,
728 GNUNET_assert (GNUNET_YES ==
729 GNUNET_CONTAINER_multihashmap_remove (all_known_peers,
732 if (NULL != to_remove->info_ctx)
734 GNUNET_ATS_peer_change_preference_cancel (to_remove->info_ctx);
735 to_remove->info_ctx = NULL;
737 if (GNUNET_SCHEDULER_NO_TASK != to_remove->preference_task)
739 GNUNET_SCHEDULER_cancel (to_remove->preference_task);
740 to_remove->preference_task = GNUNET_SCHEDULER_NO_TASK;
742 current_bucket = find_bucket (&to_remove->id.hashPubKey);
743 GNUNET_assert (current_bucket >= 0);
744 GNUNET_CONTAINER_DLL_remove (k_buckets[current_bucket].head,
745 k_buckets[current_bucket].tail,
747 GNUNET_assert (k_buckets[current_bucket].peers_size > 0);
748 k_buckets[current_bucket].peers_size--;
749 while ( (closest_bucket > 0) &&
750 (k_buckets[closest_bucket].peers_size == 0) )
753 if (to_remove->th != NULL)
755 GNUNET_CORE_notify_transmit_ready_cancel (to_remove->th);
756 to_remove->th = NULL;
759 while (NULL != (pos = to_remove->head))
761 GNUNET_CONTAINER_DLL_remove (to_remove->head,
767 GNUNET_STATISTICS_update (GDS_stats,
768 gettext_noop ("# Queued messages discarded (peer disconnected)"), discarded,
770 GNUNET_free (to_remove);
775 * Called when core is ready to send a message we asked for
776 * out to the destination.
778 * @param cls the 'struct PeerInfo' of the target peer
779 * @param size number of bytes available in buf
780 * @param buf where the callee should write the message
781 * @return number of bytes written to buf
784 core_transmit_notify (void *cls, size_t size, void *buf)
786 struct PeerInfo *peer = cls;
788 struct P2PPendingMessage *pending;
793 while ( (NULL != (pending = peer->head)) &&
794 (GNUNET_TIME_absolute_get_remaining (pending->timeout).rel_value == 0) )
796 peer->pending_count--;
797 GNUNET_CONTAINER_DLL_remove (peer->head, peer->tail, pending);
798 GNUNET_free (pending);
802 /* no messages pending */
808 = GNUNET_CORE_notify_transmit_ready (coreAPI, GNUNET_YES,
810 GNUNET_TIME_absolute_get_remaining (pending->timeout),
811 &peer->id, ntohs (pending->msg->size),
812 &core_transmit_notify, peer);
813 GNUNET_break (NULL != peer->th);
817 while ( (NULL != (pending = peer->head)) &&
818 (size - off >= (msize = ntohs (pending->msg->size))) )
820 GNUNET_STATISTICS_update (GDS_stats,
821 gettext_noop ("# Bytes transmitted to other peers"), msize,
823 memcpy (&cbuf[off], pending->msg, msize);
825 peer->pending_count--;
826 GNUNET_CONTAINER_DLL_remove (peer->head, peer->tail, pending);
827 GNUNET_free (pending);
829 if (peer->head != NULL)
832 = GNUNET_CORE_notify_transmit_ready (coreAPI, GNUNET_YES,
834 GNUNET_TIME_absolute_get_remaining (pending->timeout),
836 &core_transmit_notify, peer);
837 GNUNET_break (NULL != peer->th);
844 * Transmit all messages in the peer's message queue.
846 * @param peer message queue to process
849 process_peer_queue (struct PeerInfo *peer)
851 struct P2PPendingMessage *pending;
853 if (NULL == (pending = peer->head))
855 if (NULL != peer->th)
857 GNUNET_STATISTICS_update (GDS_stats,
858 gettext_noop ("# Bytes of bandwdith requested from core"),
859 ntohs (pending->msg->size),
862 = GNUNET_CORE_notify_transmit_ready (coreAPI, GNUNET_YES,
864 GNUNET_TIME_absolute_get_remaining (pending->timeout),
866 ntohs (pending->msg->size),
867 &core_transmit_notify, peer);
868 GNUNET_break (NULL != peer->th);
873 * To how many peers should we (on average) forward the request to
874 * obtain the desired target_replication count (on average).
876 * @param hop_count number of hops the message has traversed
877 * @param target_replication the number of total paths desired
878 * @return Some number of peers to forward the message to
881 get_forward_count (uint32_t hop_count,
882 uint32_t target_replication)
884 uint32_t random_value;
885 uint32_t forward_count;
888 if (hop_count > GDS_NSE_get () * 6.0)
890 /* forcefully terminate */
893 if (hop_count > GDS_NSE_get () * 4.0)
895 /* Once we have reached our ideal number of hops, only forward to 1 peer */
898 /* bound by system-wide maximum */
899 target_replication = GNUNET_MIN (MAXIMUM_REPLICATION_LEVEL,
902 1 + (target_replication - 1.0) / (GDS_NSE_get () +
903 ((float) (target_replication - 1.0) *
905 /* Set forward count to floor of target_value */
906 forward_count = (uint32_t) target_value;
907 /* Subtract forward_count (floor) from target_value (yields value between 0 and 1) */
908 target_value = target_value - forward_count;
910 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, UINT32_MAX);
911 if (random_value < (target_value * UINT32_MAX))
913 return forward_count;
918 * Compute the distance between have and target as a 32-bit value.
919 * Differences in the lower bits must count stronger than differences
920 * in the higher bits.
922 * @return 0 if have==target, otherwise a number
923 * that is larger as the distance between
924 * the two hash codes increases
927 get_distance (const GNUNET_HashCode * target, const GNUNET_HashCode * have)
934 /* We have to represent the distance between two 2^9 (=512)-bit
935 * numbers as a 2^5 (=32)-bit number with "0" being used for the
936 * two numbers being identical; furthermore, we need to
937 * guarantee that a difference in the number of matching
938 * bits is always represented in the result.
940 * We use 2^32/2^9 numerical values to distinguish between
941 * hash codes that have the same LSB bit distance and
942 * use the highest 2^9 bits of the result to signify the
943 * number of (mis)matching LSB bits; if we have 0 matching
944 * and hence 512 mismatching LSB bits we return -1 (since
945 * 512 itself cannot be represented with 9 bits) */
947 /* first, calculate the most significant 9 bits of our
948 * result, aka the number of LSBs */
949 bucket = GNUNET_CRYPTO_hash_matching_bits (target, have);
950 /* bucket is now a value between 0 and 512 */
952 return 0; /* perfect match */
954 return (unsigned int) -1; /* LSB differs; use max (if we did the bit-shifting
955 * below, we'd end up with max+1 (overflow)) */
957 /* calculate the most significant bits of the final result */
958 msb = (512 - bucket) << (32 - 9);
959 /* calculate the 32-9 least significant bits of the final result by
960 * looking at the differences in the 32-9 bits following the
961 * mismatching bit at 'bucket' */
964 (i < sizeof (GNUNET_HashCode) * 8) && (i < bucket + 1 + 32 - 9); i++)
966 if (GNUNET_CRYPTO_hash_get_bit (target, i) !=
967 GNUNET_CRYPTO_hash_get_bit (have, i))
968 lsb |= (1 << (bucket + 32 - 9 - i)); /* first bit set will be 10,
969 * last bit set will be 31 -- if
970 * i does not reach 512 first... */
977 * Check whether my identity is closer than any known peers. If a
978 * non-null bloomfilter is given, check if this is the closest peer
979 * that hasn't already been routed to.
981 * @param key hash code to check closeness to
982 * @param bloom bloomfilter, exclude these entries from the decision
983 * @return GNUNET_YES if node location is closest,
984 * GNUNET_NO otherwise.
987 am_closest_peer (const GNUNET_HashCode *key,
988 const struct GNUNET_CONTAINER_BloomFilter *bloom)
994 struct PeerInfo *pos;
996 if (0 == memcmp (&my_identity.hashPubKey, key, sizeof (GNUNET_HashCode)))
998 bucket_num = find_bucket (key);
999 GNUNET_assert (bucket_num >= 0);
1000 bits = GNUNET_CRYPTO_hash_matching_bits (&my_identity.hashPubKey, key);
1001 pos = k_buckets[bucket_num].head;
1003 while ((pos != NULL) && (count < bucket_size))
1005 if ((bloom != NULL) &&
1007 GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)))
1010 continue; /* Skip already checked entries */
1012 other_bits = GNUNET_CRYPTO_hash_matching_bits (&pos->id.hashPubKey, key);
1013 if (other_bits > bits)
1015 if (other_bits == bits) /* We match the same number of bits */
1019 /* No peers closer, we are the closest! */
1025 * Select a peer from the routing table that would be a good routing
1026 * destination for sending a message for "key". The resulting peer
1027 * must not be in the set of blocked peers.<p>
1029 * Note that we should not ALWAYS select the closest peer to the
1030 * target, peers further away from the target should be chosen with
1031 * exponentially declining probability.
1033 * FIXME: double-check that this is fine
1036 * @param key the key we are selecting a peer to route to
1037 * @param bloom a bloomfilter containing entries this request has seen already
1038 * @param hops how many hops has this message traversed thus far
1039 * @return Peer to route to, or NULL on error
1041 static struct PeerInfo *
1042 select_peer (const GNUNET_HashCode *key,
1043 const struct GNUNET_CONTAINER_BloomFilter *bloom,
1048 unsigned int selected;
1049 struct PeerInfo *pos;
1051 unsigned int smallest_distance;
1052 struct PeerInfo *chosen;
1054 if (hops >= GDS_NSE_get ())
1056 /* greedy selection (closest peer that is not in bloomfilter) */
1057 smallest_distance = UINT_MAX;
1059 for (bc = 0; bc < closest_bucket; bc++)
1061 pos = k_buckets[bc].head;
1063 while ((pos != NULL) && (count < bucket_size))
1065 if ( (bloom == NULL) ||
1067 GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)) )
1069 dist = get_distance (key, &pos->id.hashPubKey);
1070 if (dist < smallest_distance)
1073 smallest_distance = dist;
1078 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1079 "Excluded peer `%s' due to BF match in greedy routing for %s\n",
1080 GNUNET_i2s (&pos->id),
1082 GNUNET_STATISTICS_update (GDS_stats,
1083 gettext_noop ("# Peers excluded from routing due to Bloomfilter"), 1,
1091 GNUNET_STATISTICS_update (GDS_stats,
1092 gettext_noop ("# Peer selection failed"), 1,
1097 /* select "random" peer */
1098 /* count number of peers that are available and not filtered */
1100 for (bc = closest_bucket; bc < MAX_BUCKETS; bc++)
1102 pos = k_buckets[bc].head;
1103 while ((pos != NULL) && (count < bucket_size))
1105 if ( (bloom != NULL) &&
1107 GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)) )
1109 GNUNET_STATISTICS_update (GDS_stats,
1110 gettext_noop ("# Peers excluded from routing due to Bloomfilter"), 1,
1112 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1113 "Excluded peer `%s' due to BF match in random routing for %s\n",
1114 GNUNET_i2s (&pos->id),
1117 continue; /* Ignore bloomfiltered peers */
1123 if (count == 0) /* No peers to select from! */
1125 GNUNET_STATISTICS_update (GDS_stats,
1126 gettext_noop ("# Peer selection failed"), 1,
1130 /* Now actually choose a peer */
1131 selected = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, count);
1133 for (bc = closest_bucket; bc < MAX_BUCKETS; bc++)
1135 pos = k_buckets[bc].head;
1136 while ((pos != NULL) && (count < bucket_size))
1138 if ( (bloom != NULL) &&
1140 GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)) )
1143 continue; /* Ignore bloomfiltered peers */
1145 if (0 == selected--)
1156 * Compute the set of peers that the given request should be
1159 * @param key routing key
1160 * @param bloom bloom filter excluding peers as targets, all selected
1161 * peers will be added to the bloom filter
1162 * @param hop_count number of hops the request has traversed so far
1163 * @param target_replication desired number of replicas
1164 * @param targets where to store an array of target peers (to be
1165 * free'd by the caller)
1166 * @return number of peers returned in 'targets'.
1169 get_target_peers (const GNUNET_HashCode *key,
1170 struct GNUNET_CONTAINER_BloomFilter *bloom,
1172 uint32_t target_replication,
1173 struct PeerInfo ***targets)
1177 struct PeerInfo **rtargets;
1178 struct PeerInfo *nxt;
1180 GNUNET_assert (NULL != bloom);
1181 ret = get_forward_count (hop_count, target_replication);
1187 rtargets = GNUNET_malloc (sizeof (struct PeerInfo*) * ret);
1188 for (off = 0; off < ret; off++)
1190 nxt = select_peer (key, bloom, hop_count);
1193 rtargets[off] = nxt;
1194 GNUNET_break (GNUNET_NO ==
1195 GNUNET_CONTAINER_bloomfilter_test (bloom, &nxt->id.hashPubKey));
1196 GNUNET_CONTAINER_bloomfilter_add (bloom, &rtargets[off]->id.hashPubKey);
1198 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1199 "Selected %u/%u peers at hop %u for %s (target was %u)\n",
1201 GNUNET_CONTAINER_multihashmap_size (all_known_peers),
1202 (unsigned int) hop_count,
1207 GNUNET_free (rtargets);
1211 *targets = rtargets;
1217 * Perform a PUT operation. Forwards the given request to other
1218 * peers. Does not store the data locally. Does not give the
1219 * data to local clients. May do nothing if this is the only
1220 * peer in the network (or if we are the closest peer in the
1223 * @param type type of the block
1224 * @param options routing options
1225 * @param desired_replication_level desired replication count
1226 * @param expiration_time when does the content expire
1227 * @param hop_count how many hops has this message traversed so far
1228 * @param bf Bloom filter of peers this PUT has already traversed
1229 * @param key key for the content
1230 * @param put_path_length number of entries in put_path
1231 * @param put_path peers this request has traversed so far (if tracked)
1232 * @param data payload to store
1233 * @param data_size number of bytes in data
1236 GDS_NEIGHBOURS_handle_put (enum GNUNET_BLOCK_Type type,
1237 enum GNUNET_DHT_RouteOption options,
1238 uint32_t desired_replication_level,
1239 struct GNUNET_TIME_Absolute expiration_time,
1241 struct GNUNET_CONTAINER_BloomFilter *bf,
1242 const GNUNET_HashCode *key,
1243 unsigned int put_path_length,
1244 struct GNUNET_PeerIdentity *put_path,
1248 unsigned int target_count;
1250 struct PeerInfo **targets;
1251 struct PeerInfo *target;
1252 struct P2PPendingMessage *pending;
1254 struct PeerPutMessage *ppm;
1255 struct GNUNET_PeerIdentity *pp;
1257 GNUNET_assert (NULL != bf);
1258 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1259 "Adding myself (%s) to PUT bloomfilter for %s\n",
1260 GNUNET_i2s (&my_identity),
1262 GNUNET_CONTAINER_bloomfilter_add (bf, &my_identity.hashPubKey);
1263 GNUNET_STATISTICS_update (GDS_stats,
1264 gettext_noop ("# PUT requests routed"), 1,
1266 target_count = get_target_peers (key, bf, hop_count,
1267 desired_replication_level,
1269 if (0 == target_count)
1271 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1272 "Routing PUT for %s terminates after %u hops at %s\n",
1274 (unsigned int) hop_count,
1275 GNUNET_i2s (&my_identity));
1278 msize = put_path_length * sizeof (struct GNUNET_PeerIdentity) + data_size + sizeof (struct PeerPutMessage);
1279 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1281 put_path_length = 0;
1282 msize = data_size + sizeof (struct PeerPutMessage);
1284 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1289 GNUNET_STATISTICS_update (GDS_stats,
1290 gettext_noop ("# PUT messages queued for transmission"), target_count,
1292 for (i=0;i<target_count;i++)
1294 target = targets[i];
1295 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1296 "Routing PUT for %s after %u hops to %s\n",
1298 (unsigned int) hop_count,
1299 GNUNET_i2s (&target->id));
1300 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1301 pending->importance = 0; /* FIXME */
1302 pending->timeout = expiration_time;
1303 ppm = (struct PeerPutMessage*) &pending[1];
1304 pending->msg = &ppm->header;
1305 ppm->header.size = htons (msize);
1306 ppm->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_P2P_PUT);
1307 ppm->options = htonl (options);
1308 ppm->type = htonl (type);
1309 ppm->hop_count = htonl (hop_count + 1);
1310 ppm->desired_replication_level = htonl (desired_replication_level);
1311 ppm->put_path_length = htonl (put_path_length);
1312 ppm->expiration_time = GNUNET_TIME_absolute_hton (expiration_time);
1313 GNUNET_break (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (bf, &target->id.hashPubKey));
1314 GNUNET_assert (GNUNET_OK ==
1315 GNUNET_CONTAINER_bloomfilter_get_raw_data (bf,
1319 pp = (struct GNUNET_PeerIdentity*) &ppm[1];
1320 memcpy (pp, put_path, sizeof (struct GNUNET_PeerIdentity) * put_path_length);
1321 memcpy (&pp[put_path_length], data, data_size);
1322 GNUNET_CONTAINER_DLL_insert_tail (target->head,
1325 target->pending_count++;
1326 process_peer_queue (target);
1328 GNUNET_free (targets);
1333 * Perform a GET operation. Forwards the given request to other
1334 * peers. Does not lookup the key locally. May do nothing if this is
1335 * the only peer in the network (or if we are the closest peer in the
1338 * @param type type of the block
1339 * @param options routing options
1340 * @param desired_replication_level desired replication count
1341 * @param hop_count how many hops did this request traverse so far?
1342 * @param key key for the content
1343 * @param xquery extended query
1344 * @param xquery_size number of bytes in xquery
1345 * @param reply_bf bloomfilter to filter duplicates
1346 * @param reply_bf_mutator mutator for reply_bf
1347 * @param peer_bf filter for peers not to select (again)
1350 GDS_NEIGHBOURS_handle_get (enum GNUNET_BLOCK_Type type,
1351 enum GNUNET_DHT_RouteOption options,
1352 uint32_t desired_replication_level,
1354 const GNUNET_HashCode *key,
1357 const struct GNUNET_CONTAINER_BloomFilter *reply_bf,
1358 uint32_t reply_bf_mutator,
1359 struct GNUNET_CONTAINER_BloomFilter *peer_bf)
1361 unsigned int target_count;
1363 struct PeerInfo **targets;
1364 struct PeerInfo *target;
1365 struct P2PPendingMessage *pending;
1367 struct PeerGetMessage *pgm;
1369 size_t reply_bf_size;
1371 GNUNET_assert (NULL != peer_bf);
1372 GNUNET_STATISTICS_update (GDS_stats,
1373 gettext_noop ("# GET requests routed"), 1,
1375 target_count = get_target_peers (key, peer_bf, hop_count,
1376 desired_replication_level,
1378 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1379 "Adding myself (%s) to GET bloomfilter for %s\n",
1380 GNUNET_i2s (&my_identity),
1382 GNUNET_CONTAINER_bloomfilter_add (peer_bf, &my_identity.hashPubKey);
1383 if (0 == target_count)
1385 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1386 "Routing GET for %s terminates after %u hops at %s\n",
1388 (unsigned int) hop_count,
1389 GNUNET_i2s (&my_identity));
1392 reply_bf_size = GNUNET_CONTAINER_bloomfilter_get_size (reply_bf);
1393 msize = xquery_size + sizeof (struct PeerGetMessage) + reply_bf_size;
1394 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1397 GNUNET_free (targets);
1400 GNUNET_STATISTICS_update (GDS_stats,
1401 gettext_noop ("# GET messages queued for transmission"), target_count,
1403 /* forward request */
1404 for (i=0;i<target_count;i++)
1406 target = targets[i];
1407 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1408 "Routing GET for %s after %u hops to %s\n",
1410 (unsigned int) hop_count,
1411 GNUNET_i2s (&target->id));
1412 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1413 pending->importance = 0; /* FIXME */
1414 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1415 pgm = (struct PeerGetMessage*) &pending[1];
1416 pending->msg = &pgm->header;
1417 pgm->header.size = htons (msize);
1418 pgm->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_P2P_GET);
1419 pgm->options = htonl (options);
1420 pgm->type = htonl (type);
1421 pgm->hop_count = htonl (hop_count + 1);
1422 pgm->desired_replication_level = htonl (desired_replication_level);
1423 pgm->xquery_size = htonl (xquery_size);
1424 pgm->bf_mutator = reply_bf_mutator;
1425 GNUNET_break (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (peer_bf, &target->id.hashPubKey));
1426 GNUNET_assert (GNUNET_OK ==
1427 GNUNET_CONTAINER_bloomfilter_get_raw_data (peer_bf,
1431 xq = (char *) &pgm[1];
1432 memcpy (xq, xquery, xquery_size);
1433 if (NULL != reply_bf)
1434 GNUNET_assert (GNUNET_OK ==
1435 GNUNET_CONTAINER_bloomfilter_get_raw_data (reply_bf,
1438 GNUNET_CONTAINER_DLL_insert_tail (target->head,
1441 target->pending_count++;
1442 process_peer_queue (target);
1444 GNUNET_free (targets);
1449 * Handle a reply (route to origin). Only forwards the reply back to
1450 * the given peer. Does not do local caching or forwarding to local
1453 * @param target neighbour that should receive the block (if still connected)
1454 * @param type type of the block
1455 * @param expiration_time when does the content expire
1456 * @param key key for the content
1457 * @param put_path_length number of entries in put_path
1458 * @param put_path peers the original PUT traversed (if tracked)
1459 * @param get_path_length number of entries in put_path
1460 * @param get_path peers this reply has traversed so far (if tracked)
1461 * @param data payload of the reply
1462 * @param data_size number of bytes in data
1465 GDS_NEIGHBOURS_handle_reply (const struct GNUNET_PeerIdentity *target,
1466 enum GNUNET_BLOCK_Type type,
1467 struct GNUNET_TIME_Absolute expiration_time,
1468 const GNUNET_HashCode *key,
1469 unsigned int put_path_length,
1470 const struct GNUNET_PeerIdentity *put_path,
1471 unsigned int get_path_length,
1472 const struct GNUNET_PeerIdentity *get_path,
1476 struct PeerInfo *pi;
1477 struct P2PPendingMessage *pending;
1479 struct PeerResultMessage *prm;
1480 struct GNUNET_PeerIdentity *paths;
1482 msize = data_size + sizeof (struct PeerResultMessage) +
1483 (get_path_length + put_path_length) * sizeof (struct GNUNET_PeerIdentity);
1484 if ( (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
1485 (get_path_length > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) ||
1486 (put_path_length > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) ||
1487 (data_size > GNUNET_SERVER_MAX_MESSAGE_SIZE) )
1492 pi = GNUNET_CONTAINER_multihashmap_get (all_known_peers,
1493 &target->hashPubKey);
1496 /* peer disconnected in the meantime, drop reply */
1499 GNUNET_STATISTICS_update (GDS_stats,
1500 gettext_noop ("# RESULT messages queued for transmission"), 1,
1502 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1503 pending->importance = 0; /* FIXME */
1504 pending->timeout = expiration_time;
1505 prm = (struct PeerResultMessage*) &pending[1];
1506 pending->msg = &prm->header;
1507 prm->header.size = htons (msize);
1508 prm->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_P2P_RESULT);
1509 prm->type = htonl (type);
1510 prm->put_path_length = htonl (put_path_length);
1511 prm->get_path_length = htonl (get_path_length);
1512 prm->expiration_time = GNUNET_TIME_absolute_hton (expiration_time);
1514 paths = (struct GNUNET_PeerIdentity*) &prm[1];
1515 memcpy (paths, put_path, put_path_length * sizeof (struct GNUNET_PeerIdentity));
1516 memcpy (&paths[put_path_length],
1517 get_path, get_path_length * sizeof (struct GNUNET_PeerIdentity));
1518 memcpy (&paths[put_path_length + get_path_length],
1520 GNUNET_CONTAINER_DLL_insert (pi->head,
1523 pi->pending_count++;
1524 process_peer_queue (pi);
1529 * To be called on core init/fail.
1531 * @param cls service closure
1532 * @param server handle to the server for this service
1533 * @param identity the public identity of this peer
1536 core_init (void *cls, struct GNUNET_CORE_Handle *server,
1537 const struct GNUNET_PeerIdentity *identity)
1539 GNUNET_assert (server != NULL);
1540 my_identity = *identity;
1545 * Core handler for p2p put requests.
1547 * @param cls closure
1548 * @param peer sender of the request
1549 * @param message message
1550 * @param peer peer identity this notification is about
1551 * @param atsi performance data
1552 * @return GNUNET_OK to keep the connection open,
1553 * GNUNET_SYSERR to close it (signal serious error)
1556 handle_dht_p2p_put (void *cls,
1557 const struct GNUNET_PeerIdentity *peer,
1558 const struct GNUNET_MessageHeader *message,
1559 const struct GNUNET_TRANSPORT_ATS_Information
1562 const struct PeerPutMessage *put;
1563 const struct GNUNET_PeerIdentity *put_path;
1564 const void *payload;
1567 size_t payload_size;
1568 enum GNUNET_DHT_RouteOption options;
1569 struct GNUNET_CONTAINER_BloomFilter *bf;
1570 GNUNET_HashCode test_key;
1572 msize = ntohs (message->size);
1573 if (msize < sizeof (struct PeerPutMessage))
1575 GNUNET_break_op (0);
1578 put = (const struct PeerPutMessage*) message;
1579 putlen = ntohl (put->put_path_length);
1580 if ( (msize < sizeof (struct PeerPutMessage) + putlen * sizeof (struct GNUNET_PeerIdentity)) ||
1581 (putlen > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) )
1583 GNUNET_break_op (0);
1586 GNUNET_STATISTICS_update (GDS_stats,
1587 gettext_noop ("# P2P PUT requests received"), 1,
1589 put_path = (const struct GNUNET_PeerIdentity*) &put[1];
1590 payload = &put_path[putlen];
1591 options = ntohl (put->options);
1592 payload_size = msize - (sizeof (struct PeerPutMessage) +
1593 putlen * sizeof (struct GNUNET_PeerIdentity));
1594 switch (GNUNET_BLOCK_get_key (GDS_block_context,
1596 payload, payload_size,
1600 if (0 != memcmp (&test_key, &put->key, sizeof (GNUNET_HashCode)))
1602 GNUNET_break_op (0);
1607 GNUNET_break_op (0);
1610 /* cannot verify, good luck */
1613 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1614 "PUT for %s at %s\n",
1615 GNUNET_h2s (&put->key),
1616 GNUNET_i2s (&my_identity));
1617 bf = GNUNET_CONTAINER_bloomfilter_init (put->bloomfilter,
1619 GNUNET_CONSTANTS_BLOOMFILTER_K);
1620 GNUNET_break_op (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (bf, &peer->hashPubKey));
1622 struct GNUNET_PeerIdentity pp[putlen+1];
1624 /* extend 'put path' by sender */
1625 if (0 != (options & GNUNET_DHT_RO_RECORD_ROUTE))
1627 memcpy (pp, put_path, putlen * sizeof (struct GNUNET_PeerIdentity));
1634 /* give to local clients */
1635 GDS_CLIENTS_handle_reply (GNUNET_TIME_absolute_ntoh (put->expiration_time),
1644 if ( (0 != (options & GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE)) ||
1645 (am_closest_peer (&put->key,
1647 GDS_DATACACHE_handle_put (GNUNET_TIME_absolute_ntoh (put->expiration_time),
1653 /* route to other peers */
1654 GDS_NEIGHBOURS_handle_put (ntohl (put->type),
1656 ntohl (put->desired_replication_level),
1657 GNUNET_TIME_absolute_ntoh (put->expiration_time),
1658 ntohl (put->hop_count),
1665 GNUNET_CONTAINER_bloomfilter_free (bf);
1671 * We have received a FIND PEER request. Send matching
1674 * @param sender sender of the FIND PEER request
1675 * @param key peers close to this key are desired
1676 * @param bf peers matching this bf are excluded
1677 * @param bf_mutator mutator for bf
1680 handle_find_peer (const struct GNUNET_PeerIdentity *sender,
1681 const GNUNET_HashCode *key,
1682 struct GNUNET_CONTAINER_BloomFilter *bf,
1683 uint32_t bf_mutator)
1686 struct PeerBucket *bucket;
1687 struct PeerInfo *peer;
1688 unsigned int choice;
1689 GNUNET_HashCode mhash;
1690 const struct GNUNET_HELLO_Message *hello;
1692 /* first, check about our own HELLO */
1693 if (NULL != GDS_my_hello)
1695 GNUNET_BLOCK_mingle_hash (&my_identity.hashPubKey, bf_mutator, &mhash);
1696 if ( (NULL == bf) ||
1697 (GNUNET_YES != GNUNET_CONTAINER_bloomfilter_test (bf, &mhash)) )
1699 GDS_NEIGHBOURS_handle_reply (sender,
1700 GNUNET_BLOCK_TYPE_DHT_HELLO,
1701 GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_HELLO_ADDRESS_EXPIRATION),
1706 GNUNET_HELLO_size ((const struct GNUNET_HELLO_Message*) GDS_my_hello));
1710 GNUNET_STATISTICS_update (GDS_stats,
1711 gettext_noop ("# FIND PEER requests ignored due to Bloomfilter"), 1,
1717 GNUNET_STATISTICS_update (GDS_stats,
1718 gettext_noop ("# FIND PEER requests ignored due to lack of HELLO"), 1,
1722 /* then, also consider sending a random HELLO from the closest bucket */
1723 if (0 == memcmp (&my_identity.hashPubKey, key, sizeof (GNUNET_HashCode)))
1724 bucket_idx = closest_bucket;
1726 bucket_idx = GNUNET_MIN (closest_bucket, find_bucket (key));
1727 if (bucket_idx == GNUNET_SYSERR)
1729 bucket = &k_buckets[bucket_idx];
1730 if (bucket->peers_size == 0)
1732 choice = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
1733 bucket->peers_size);
1734 peer = bucket->head;
1737 GNUNET_assert (peer != NULL);
1741 choice = bucket->peers_size;
1746 return; /* no non-masked peer available */
1748 peer = bucket->head;
1749 GNUNET_BLOCK_mingle_hash (&peer->id.hashPubKey, bf_mutator, &mhash);
1750 hello = GDS_HELLO_get (&peer->id);
1752 while ( (hello == NULL) ||
1753 (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (bf, &mhash)) );
1754 GDS_NEIGHBOURS_handle_reply (sender,
1755 GNUNET_BLOCK_TYPE_DHT_HELLO,
1756 GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_HELLO_ADDRESS_EXPIRATION),
1761 GNUNET_HELLO_size (hello));
1766 * Core handler for p2p get requests.
1768 * @param cls closure
1769 * @param peer sender of the request
1770 * @param message message
1771 * @param peer peer identity this notification is about
1772 * @param atsi performance data
1773 * @return GNUNET_OK to keep the connection open,
1774 * GNUNET_SYSERR to close it (signal serious error)
1777 handle_dht_p2p_get (void *cls, const struct GNUNET_PeerIdentity *peer,
1778 const struct GNUNET_MessageHeader *message,
1779 const struct GNUNET_TRANSPORT_ATS_Information
1782 struct PeerGetMessage *get;
1783 uint32_t xquery_size;
1784 size_t reply_bf_size;
1786 enum GNUNET_BLOCK_Type type;
1787 enum GNUNET_DHT_RouteOption options;
1788 enum GNUNET_BLOCK_EvaluationResult eval;
1789 struct GNUNET_CONTAINER_BloomFilter *reply_bf;
1790 struct GNUNET_CONTAINER_BloomFilter *peer_bf;
1793 GNUNET_break (0 != memcmp (peer, &my_identity, sizeof (struct GNUNET_PeerIdentity)));
1794 /* parse and validate message */
1795 msize = ntohs (message->size);
1796 if (msize < sizeof (struct PeerGetMessage))
1798 GNUNET_break_op (0);
1801 get = (struct PeerGetMessage *) message;
1802 xquery_size = ntohl (get->xquery_size);
1803 if (msize < sizeof (struct PeerGetMessage) + xquery_size)
1805 GNUNET_break_op (0);
1808 GNUNET_STATISTICS_update (GDS_stats,
1809 gettext_noop ("# P2P GET requests received"), 1,
1811 reply_bf_size = msize - (sizeof (struct PeerGetMessage) + xquery_size);
1812 type = ntohl (get->type);
1813 options = ntohl (get->options);
1814 xquery = (const char*) &get[1];
1816 if (reply_bf_size > 0)
1817 reply_bf = GNUNET_CONTAINER_bloomfilter_init (&xquery[xquery_size],
1819 GNUNET_CONSTANTS_BLOOMFILTER_K);
1820 eval = GNUNET_BLOCK_evaluate (GDS_block_context,
1825 xquery, xquery_size,
1827 if (eval != GNUNET_BLOCK_EVALUATION_REQUEST_VALID)
1829 /* request invalid or block type not supported */
1830 GNUNET_break_op (eval == GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED);
1831 if (NULL != reply_bf)
1832 GNUNET_CONTAINER_bloomfilter_free (reply_bf);
1836 GNUNET_CONTAINER_bloomfilter_init (get->bloomfilter,
1838 GNUNET_CONSTANTS_BLOOMFILTER_K);
1839 GNUNET_break_op (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (peer_bf, &peer->hashPubKey));
1840 /* remember request for routing replies */
1841 GDS_ROUTING_add (peer,
1845 xquery, xquery_size,
1846 reply_bf, get->bf_mutator);
1847 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1848 "GET for %s at %s after %u hops\n",
1849 GNUNET_h2s (&get->key),
1850 GNUNET_i2s (&my_identity),
1851 (unsigned int) ntohl (get->hop_count));
1852 /* local lookup (this may update the reply_bf) */
1853 if ( (0 != (options & GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE)) ||
1854 (am_closest_peer (&get->key,
1857 if ( (0 != (options & GNUNET_DHT_RO_FIND_PEER)))
1859 GNUNET_STATISTICS_update (GDS_stats,
1860 gettext_noop ("# P2P FIND PEER requests processed"), 1,
1862 handle_find_peer (peer,
1869 eval = GDS_DATACACHE_handle_get (&get->key,
1871 xquery, xquery_size,
1878 GNUNET_STATISTICS_update (GDS_stats,
1879 gettext_noop ("# P2P GET requests ONLY routed"), 1,
1883 /* P2P forwarding */
1884 if (eval != GNUNET_BLOCK_EVALUATION_OK_LAST)
1885 GDS_NEIGHBOURS_handle_get (type,
1887 ntohl (get->desired_replication_level),
1888 ntohl (get->hop_count),
1890 xquery, xquery_size,
1895 if (NULL != reply_bf)
1896 GNUNET_CONTAINER_bloomfilter_free (reply_bf);
1897 GNUNET_CONTAINER_bloomfilter_free (peer_bf);
1903 * Core handler for p2p result messages.
1905 * @param cls closure
1906 * @param message message
1907 * @param peer peer identity this notification is about
1908 * @param atsi performance data
1909 * @return GNUNET_YES (do not cut p2p connection)
1912 handle_dht_p2p_result (void *cls, const struct GNUNET_PeerIdentity *peer,
1913 const struct GNUNET_MessageHeader *message,
1914 const struct GNUNET_TRANSPORT_ATS_Information
1917 const struct PeerResultMessage *prm;
1918 const struct GNUNET_PeerIdentity *put_path;
1919 const struct GNUNET_PeerIdentity *get_path;
1921 uint32_t get_path_length;
1922 uint32_t put_path_length;
1925 enum GNUNET_BLOCK_Type type;
1927 /* parse and validate message */
1928 msize = ntohs (message->size);
1929 if (msize < sizeof (struct PeerResultMessage))
1931 GNUNET_break_op (0);
1934 prm = (struct PeerResultMessage *) message;
1935 put_path_length = ntohl (prm->put_path_length);
1936 get_path_length = ntohl (prm->get_path_length);
1937 if ( (msize < sizeof (struct PeerResultMessage) +
1938 (get_path_length + put_path_length) * sizeof (struct GNUNET_PeerIdentity)) ||
1939 (get_path_length > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) ||
1940 (put_path_length > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) )
1942 GNUNET_break_op (0);
1945 GNUNET_STATISTICS_update (GDS_stats,
1946 gettext_noop ("# P2P RESULTS received"), 1,
1948 put_path = (const struct GNUNET_PeerIdentity*) &prm[1];
1949 get_path = &put_path[put_path_length];
1950 type = ntohl (prm->type);
1951 data = (const void*) &get_path[get_path_length];
1952 data_size = msize - (sizeof (struct PeerResultMessage) +
1953 (get_path_length + put_path_length) * sizeof (struct GNUNET_PeerIdentity));
1955 /* if we got a HELLO, consider it for our own routing table */
1956 if (type == GNUNET_BLOCK_TYPE_DHT_HELLO)
1958 const struct GNUNET_MessageHeader *h;
1959 struct GNUNET_PeerIdentity pid;
1962 /* Should be a HELLO, validate and consider using it! */
1963 if (data_size < sizeof (struct GNUNET_MessageHeader))
1965 GNUNET_break_op (0);
1969 if (data_size != ntohs (h->size))
1971 GNUNET_break_op (0);
1975 GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message*) h,
1978 GNUNET_break_op (0);
1981 if (0 != memcmp (&my_identity, &pid, sizeof (struct GNUNET_PeerIdentity)))
1983 bucket = find_bucket (&pid.hashPubKey);
1984 if ( (bucket >= 0) &&
1985 (k_buckets[bucket].peers_size < bucket_size) )
1987 if (NULL != GDS_transport_handle)
1989 GNUNET_TRANSPORT_offer_hello (GDS_transport_handle,
1991 GNUNET_TRANSPORT_try_connect (GDS_transport_handle,
1998 /* append 'peer' to 'get_path' */
2000 struct GNUNET_PeerIdentity xget_path[get_path_length+1];
2002 memcpy (xget_path, get_path, get_path_length * sizeof (struct GNUNET_PeerIdentity));
2003 xget_path[get_path_length] = *peer;
2006 /* forward to local clients */
2007 GDS_CLIENTS_handle_reply (GNUNET_TIME_absolute_ntoh (prm->expiration_time),
2017 /* forward to other peers */
2018 GDS_ROUTING_process (type,
2019 GNUNET_TIME_absolute_ntoh (prm->expiration_time),
2033 * Initialize neighbours subsystem.
2035 * @return GNUNET_OK on success, GNUNET_SYSERR on error
2038 GDS_NEIGHBOURS_init ()
2040 static struct GNUNET_CORE_MessageHandler core_handlers[] = {
2041 {&handle_dht_p2p_get, GNUNET_MESSAGE_TYPE_DHT_P2P_GET, 0},
2042 {&handle_dht_p2p_put, GNUNET_MESSAGE_TYPE_DHT_P2P_PUT, 0},
2043 {&handle_dht_p2p_result, GNUNET_MESSAGE_TYPE_DHT_P2P_RESULT, 0},
2046 unsigned long long temp_config_num;
2049 GNUNET_CONFIGURATION_get_value_number (GDS_cfg, "DHT", "bucket_size",
2051 bucket_size = (unsigned int) temp_config_num;
2052 atsAPI = GNUNET_ATS_init (GDS_cfg, NULL, NULL);
2053 coreAPI = GNUNET_CORE_connect (GDS_cfg,
2057 &handle_core_connect,
2058 &handle_core_disconnect,
2062 if (coreAPI == NULL)
2063 return GNUNET_SYSERR;
2064 all_known_peers = GNUNET_CONTAINER_multihashmap_create (256);
2070 * Shutdown neighbours subsystem.
2073 GDS_NEIGHBOURS_done ()
2075 if (coreAPI == NULL)
2077 GNUNET_CORE_disconnect (coreAPI);
2079 GNUNET_ATS_shutdown (atsAPI);
2081 GNUNET_assert (0 == GNUNET_CONTAINER_multihashmap_size (all_known_peers));
2082 GNUNET_CONTAINER_multihashmap_destroy (all_known_peers);
2083 all_known_peers = NULL;
2084 if (GNUNET_SCHEDULER_NO_TASK != find_peer_task)
2086 GNUNET_SCHEDULER_cancel (find_peer_task);
2087 find_peer_task = GNUNET_SCHEDULER_NO_TASK;
2092 /* end of gnunet-service-dht_neighbours.c */