2 This file is part of GNUnet.
3 (C) 2009, 2010, 2011 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file 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 * Task for scheduling preference updates
325 GNUNET_SCHEDULER_TaskIdentifier preference_task;
328 * What is the identity of the peer?
330 struct GNUNET_PeerIdentity id;
334 * What is the average latency for replies received?
336 struct GNUNET_TIME_Relative latency;
339 * Transport level distance to peer.
341 unsigned int distance;
348 * Peers are grouped into buckets.
355 struct PeerInfo *head;
360 struct PeerInfo *tail;
363 * Number of peers in the bucket.
365 unsigned int peers_size;
370 * The lowest currently used bucket, initially 0 (for 0-bits matching bucket).
372 static unsigned int closest_bucket;
375 * How many peers have we added since we sent out our last
378 static unsigned int newly_found_peers;
381 * The buckets. Array of size MAX_BUCKET_SIZE. Offset 0 means 0 bits matching.
383 static struct PeerBucket k_buckets[MAX_BUCKETS];
386 * Hash map of all known peers, for easy removal from k_buckets on disconnect.
388 static struct GNUNET_CONTAINER_MultiHashMap *all_known_peers;
391 * Maximum size for each bucket.
393 static unsigned int bucket_size = DEFAULT_BUCKET_SIZE;
396 * Task that sends FIND PEER requests.
398 static GNUNET_SCHEDULER_TaskIdentifier find_peer_task;
401 * Identity of this peer.
403 static struct GNUNET_PeerIdentity my_identity;
408 static struct GNUNET_CORE_Handle *coreAPI;
413 static struct GNUNET_ATS_PerformanceHandle *atsAPI;
418 * Find the optimal bucket for this key.
420 * @param hc the hashcode to compare our identity to
421 * @return the proper bucket index, or GNUNET_SYSERR
422 * on error (same hashcode)
425 find_bucket (const GNUNET_HashCode * hc)
429 bits = GNUNET_CRYPTO_hash_matching_bits (&my_identity.hashPubKey, hc);
430 if (bits == MAX_BUCKETS)
432 /* How can all bits match? Got my own ID? */
434 return GNUNET_SYSERR;
436 return MAX_BUCKETS - bits - 1;
441 * Let GNUnet core know that we like the given peer.
443 * @param cls the 'struct PeerInfo' of the peer
444 * @param tc scheduler context.
447 update_core_preference (void *cls,
448 const struct GNUNET_SCHEDULER_TaskContext *tc)
450 struct PeerInfo *peer = cls;
452 unsigned int matching;
455 peer->preference_task = GNUNET_SCHEDULER_NO_TASK;
456 if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
459 GNUNET_CRYPTO_hash_matching_bits (&my_identity.hashPubKey,
460 &peer->id.hashPubKey);
463 bucket = find_bucket (&peer->id.hashPubKey);
464 if (bucket == GNUNET_SYSERR)
468 GNUNET_assert (k_buckets[bucket].peers_size != 0);
469 preference = (1LL << matching) / k_buckets[bucket].peers_size;
473 peer->preference_task
474 = GNUNET_SCHEDULER_add_delayed (DHT_DEFAULT_PREFERENCE_INTERVAL,
475 &update_core_preference, peer);
478 GNUNET_STATISTICS_update (GDS_stats,
479 gettext_noop ("# Preference updates given to core"), 1,
481 GNUNET_ATS_change_preference (atsAPI, &peer->id,
482 GNUNET_ATS_PREFERENCE_BANDWIDTH,
484 GNUNET_ATS_PREFERENCE_END);
485 peer->preference_task
486 = GNUNET_SCHEDULER_add_delayed (DHT_DEFAULT_PREFERENCE_INTERVAL,
487 &update_core_preference, peer);
494 * Closure for 'add_known_to_bloom'.
496 struct BloomConstructorContext
499 * Bloom filter under construction.
501 struct GNUNET_CONTAINER_BloomFilter *bloom;
511 * Add each of the peers we already know to the bloom filter of
512 * the request so that we don't get duplicate HELLOs.
514 * @param cls the 'struct BloomConstructorContext'.
515 * @param key peer identity to add to the bloom filter
516 * @param value value the peer information (unused)
517 * @return GNUNET_YES (we should continue to iterate)
520 add_known_to_bloom (void *cls, const GNUNET_HashCode * key, void *value)
522 struct BloomConstructorContext *ctx = cls;
525 GNUNET_BLOCK_mingle_hash (key, ctx->bf_mutator, &mh);
527 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
528 "Adding known peer (%s) to bloomfilter for FIND PEER with mutation %u\n",
532 GNUNET_CONTAINER_bloomfilter_add (ctx->bloom, &mh);
538 * Task to send a find peer message for our own peer identifier
539 * so that we can find the closest peers in the network to ourselves
540 * and attempt to connect to them.
542 * @param cls closure for this task
543 * @param tc the context under which the task is running
546 send_find_peer_message (void *cls,
547 const struct GNUNET_SCHEDULER_TaskContext *tc)
549 struct GNUNET_TIME_Relative next_send_time;
550 struct BloomConstructorContext bcc;
551 struct GNUNET_CONTAINER_BloomFilter *peer_bf;
553 find_peer_task = GNUNET_SCHEDULER_NO_TASK;
554 if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
556 if (newly_found_peers > bucket_size)
558 /* If we are finding many peers already, no need to send out our request right now! */
559 find_peer_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MINUTES,
560 &send_find_peer_message, NULL);
561 newly_found_peers = 0;
564 bcc.bf_mutator = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, UINT32_MAX);
566 GNUNET_CONTAINER_bloomfilter_init (NULL, DHT_BLOOM_SIZE, GNUNET_CONSTANTS_BLOOMFILTER_K);
567 GNUNET_CONTAINER_multihashmap_iterate (all_known_peers,
570 GNUNET_STATISTICS_update (GDS_stats,
571 gettext_noop ("# FIND PEER messages initiated"), 1,
573 peer_bf = GNUNET_CONTAINER_bloomfilter_init (NULL,
575 GNUNET_CONSTANTS_BLOOMFILTER_K);
576 // FIXME: pass priority!?
577 GDS_NEIGHBOURS_handle_get (GNUNET_BLOCK_TYPE_DHT_HELLO,
578 GNUNET_DHT_RO_FIND_PEER,
579 FIND_PEER_REPLICATION_LEVEL,
581 &my_identity.hashPubKey,
583 bcc.bloom, bcc.bf_mutator,
585 GNUNET_CONTAINER_bloomfilter_free (peer_bf);
586 GNUNET_CONTAINER_bloomfilter_free (bcc.bloom);
587 /* schedule next round */
588 next_send_time.rel_value =
589 DHT_MINIMUM_FIND_PEER_INTERVAL.rel_value +
590 GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK,
591 DHT_MAXIMUM_FIND_PEER_INTERVAL.rel_value / (newly_found_peers+1));
592 newly_found_peers = 0;
593 find_peer_task = GNUNET_SCHEDULER_add_delayed (next_send_time,
594 &send_find_peer_message,
600 * Method called whenever a peer connects.
603 * @param peer peer identity this notification is about
604 * @param atsi performance data
605 * @param atsi_count number of records in 'atsi'
608 handle_core_connect (void *cls, const struct GNUNET_PeerIdentity *peer,
609 const struct GNUNET_ATS_Information *atsi,
610 unsigned int atsi_count)
612 struct PeerInfo *ret;
615 /* Check for connect to self message */
616 if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
619 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
620 "Connected %s to %s\n",
621 GNUNET_i2s (&my_identity),
622 GNUNET_h2s (&peer->hashPubKey));
625 GNUNET_CONTAINER_multihashmap_contains (all_known_peers,
631 GNUNET_STATISTICS_update (GDS_stats,
632 gettext_noop ("# Peers connected"), 1,
634 peer_bucket = find_bucket (&peer->hashPubKey);
635 GNUNET_assert ( (peer_bucket >= 0) && (peer_bucket < MAX_BUCKETS) );
636 ret = GNUNET_malloc (sizeof (struct PeerInfo));
638 ret->latency = latency;
639 ret->distance = distance;
642 GNUNET_CONTAINER_DLL_insert_tail (k_buckets[peer_bucket].head,
643 k_buckets[peer_bucket].tail, ret);
644 k_buckets[peer_bucket].peers_size++;
645 closest_bucket = GNUNET_MAX (closest_bucket,
647 if ( (peer_bucket > 0) &&
648 (k_buckets[peer_bucket].peers_size <= bucket_size) )
650 ret->preference_task = GNUNET_SCHEDULER_add_now (&update_core_preference, ret);
653 GNUNET_assert (GNUNET_OK ==
654 GNUNET_CONTAINER_multihashmap_put (all_known_peers,
655 &peer->hashPubKey, ret,
656 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
657 if (1 == GNUNET_CONTAINER_multihashmap_size (all_known_peers))
659 /* got a first connection, good time to start with FIND PEER requests... */
660 find_peer_task = GNUNET_SCHEDULER_add_now (&send_find_peer_message,
667 * Method called whenever a peer disconnects.
670 * @param peer peer identity this notification is about
673 handle_core_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer)
675 struct PeerInfo *to_remove;
677 struct P2PPendingMessage *pos;
678 unsigned int discarded;
680 /* Check for disconnect from self message */
681 if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
684 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
685 "Disconnected %s from %s\n",
686 GNUNET_i2s (&my_identity),
687 GNUNET_h2s (&peer->hashPubKey));
690 GNUNET_CONTAINER_multihashmap_get (all_known_peers, &peer->hashPubKey);
691 if (NULL == to_remove)
696 GNUNET_STATISTICS_update (GDS_stats,
697 gettext_noop ("# Peers connected"), -1,
699 GNUNET_assert (GNUNET_YES ==
700 GNUNET_CONTAINER_multihashmap_remove (all_known_peers,
703 if (GNUNET_SCHEDULER_NO_TASK != to_remove->preference_task)
705 GNUNET_SCHEDULER_cancel (to_remove->preference_task);
706 to_remove->preference_task = GNUNET_SCHEDULER_NO_TASK;
708 current_bucket = find_bucket (&to_remove->id.hashPubKey);
709 GNUNET_assert (current_bucket >= 0);
710 GNUNET_CONTAINER_DLL_remove (k_buckets[current_bucket].head,
711 k_buckets[current_bucket].tail,
713 GNUNET_assert (k_buckets[current_bucket].peers_size > 0);
714 k_buckets[current_bucket].peers_size--;
715 while ( (closest_bucket > 0) &&
716 (k_buckets[closest_bucket].peers_size == 0) )
719 if (to_remove->th != NULL)
721 GNUNET_CORE_notify_transmit_ready_cancel (to_remove->th);
722 to_remove->th = NULL;
725 while (NULL != (pos = to_remove->head))
727 GNUNET_CONTAINER_DLL_remove (to_remove->head,
733 GNUNET_STATISTICS_update (GDS_stats,
734 gettext_noop ("# Queued messages discarded (peer disconnected)"), discarded,
736 GNUNET_free (to_remove);
741 * Called when core is ready to send a message we asked for
742 * out to the destination.
744 * @param cls the 'struct PeerInfo' of the target peer
745 * @param size number of bytes available in buf
746 * @param buf where the callee should write the message
747 * @return number of bytes written to buf
750 core_transmit_notify (void *cls, size_t size, void *buf)
752 struct PeerInfo *peer = cls;
754 struct P2PPendingMessage *pending;
759 while ( (NULL != (pending = peer->head)) &&
760 (GNUNET_TIME_absolute_get_remaining (pending->timeout).rel_value == 0) )
762 peer->pending_count--;
763 GNUNET_CONTAINER_DLL_remove (peer->head, peer->tail, pending);
764 GNUNET_free (pending);
768 /* no messages pending */
774 = GNUNET_CORE_notify_transmit_ready (coreAPI, GNUNET_YES,
776 GNUNET_TIME_absolute_get_remaining (pending->timeout),
777 &peer->id, ntohs (pending->msg->size),
778 &core_transmit_notify, peer);
779 GNUNET_break (NULL != peer->th);
783 while ( (NULL != (pending = peer->head)) &&
784 (size - off >= (msize = ntohs (pending->msg->size))) )
786 GNUNET_STATISTICS_update (GDS_stats,
787 gettext_noop ("# Bytes transmitted to other peers"), msize,
789 memcpy (&cbuf[off], pending->msg, msize);
791 peer->pending_count--;
792 GNUNET_CONTAINER_DLL_remove (peer->head, peer->tail, pending);
793 GNUNET_free (pending);
795 if (peer->head != NULL)
798 = GNUNET_CORE_notify_transmit_ready (coreAPI, GNUNET_YES,
800 GNUNET_TIME_absolute_get_remaining (pending->timeout),
802 &core_transmit_notify, peer);
803 GNUNET_break (NULL != peer->th);
810 * Transmit all messages in the peer's message queue.
812 * @param peer message queue to process
815 process_peer_queue (struct PeerInfo *peer)
817 struct P2PPendingMessage *pending;
819 if (NULL == (pending = peer->head))
821 if (NULL != peer->th)
823 GNUNET_STATISTICS_update (GDS_stats,
824 gettext_noop ("# Bytes of bandwdith requested from core"),
825 ntohs (pending->msg->size),
828 = GNUNET_CORE_notify_transmit_ready (coreAPI, GNUNET_YES,
830 GNUNET_TIME_absolute_get_remaining (pending->timeout),
832 ntohs (pending->msg->size),
833 &core_transmit_notify, peer);
834 GNUNET_break (NULL != peer->th);
839 * To how many peers should we (on average) forward the request to
840 * obtain the desired target_replication count (on average).
842 * @param hop_count number of hops the message has traversed
843 * @param target_replication the number of total paths desired
844 * @return Some number of peers to forward the message to
847 get_forward_count (uint32_t hop_count,
848 uint32_t target_replication)
850 uint32_t random_value;
851 uint32_t forward_count;
854 if (hop_count > GDS_NSE_get () * 6.0)
856 /* forcefully terminate */
859 if (hop_count > GDS_NSE_get () * 4.0)
861 /* Once we have reached our ideal number of hops, only forward to 1 peer */
864 /* bound by system-wide maximum */
865 target_replication = GNUNET_MIN (MAXIMUM_REPLICATION_LEVEL,
868 1 + (target_replication - 1.0) / (GDS_NSE_get () +
869 ((float) (target_replication - 1.0) *
871 /* Set forward count to floor of target_value */
872 forward_count = (uint32_t) target_value;
873 /* Subtract forward_count (floor) from target_value (yields value between 0 and 1) */
874 target_value = target_value - forward_count;
876 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, UINT32_MAX);
877 if (random_value < (target_value * UINT32_MAX))
879 return forward_count;
884 * Compute the distance between have and target as a 32-bit value.
885 * Differences in the lower bits must count stronger than differences
886 * in the higher bits.
888 * @return 0 if have==target, otherwise a number
889 * that is larger as the distance between
890 * the two hash codes increases
893 get_distance (const GNUNET_HashCode * target, const GNUNET_HashCode * have)
900 /* We have to represent the distance between two 2^9 (=512)-bit
901 * numbers as a 2^5 (=32)-bit number with "0" being used for the
902 * two numbers being identical; furthermore, we need to
903 * guarantee that a difference in the number of matching
904 * bits is always represented in the result.
906 * We use 2^32/2^9 numerical values to distinguish between
907 * hash codes that have the same LSB bit distance and
908 * use the highest 2^9 bits of the result to signify the
909 * number of (mis)matching LSB bits; if we have 0 matching
910 * and hence 512 mismatching LSB bits we return -1 (since
911 * 512 itself cannot be represented with 9 bits) */
913 /* first, calculate the most significant 9 bits of our
914 * result, aka the number of LSBs */
915 bucket = GNUNET_CRYPTO_hash_matching_bits (target, have);
916 /* bucket is now a value between 0 and 512 */
918 return 0; /* perfect match */
920 return (unsigned int) -1; /* LSB differs; use max (if we did the bit-shifting
921 * below, we'd end up with max+1 (overflow)) */
923 /* calculate the most significant bits of the final result */
924 msb = (512 - bucket) << (32 - 9);
925 /* calculate the 32-9 least significant bits of the final result by
926 * looking at the differences in the 32-9 bits following the
927 * mismatching bit at 'bucket' */
930 (i < sizeof (GNUNET_HashCode) * 8) && (i < bucket + 1 + 32 - 9); i++)
932 if (GNUNET_CRYPTO_hash_get_bit (target, i) !=
933 GNUNET_CRYPTO_hash_get_bit (have, i))
934 lsb |= (1 << (bucket + 32 - 9 - i)); /* first bit set will be 10,
935 * last bit set will be 31 -- if
936 * i does not reach 512 first... */
943 * Check whether my identity is closer than any known peers. If a
944 * non-null bloomfilter is given, check if this is the closest peer
945 * that hasn't already been routed to.
947 * @param key hash code to check closeness to
948 * @param bloom bloomfilter, exclude these entries from the decision
949 * @return GNUNET_YES if node location is closest,
950 * GNUNET_NO otherwise.
953 am_closest_peer (const GNUNET_HashCode *key,
954 const struct GNUNET_CONTAINER_BloomFilter *bloom)
960 struct PeerInfo *pos;
962 if (0 == memcmp (&my_identity.hashPubKey, key, sizeof (GNUNET_HashCode)))
964 bucket_num = find_bucket (key);
965 GNUNET_assert (bucket_num >= 0);
966 bits = GNUNET_CRYPTO_hash_matching_bits (&my_identity.hashPubKey, key);
967 pos = k_buckets[bucket_num].head;
969 while ((pos != NULL) && (count < bucket_size))
971 if ((bloom != NULL) &&
973 GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)))
976 continue; /* Skip already checked entries */
978 other_bits = GNUNET_CRYPTO_hash_matching_bits (&pos->id.hashPubKey, key);
979 if (other_bits > bits)
981 if (other_bits == bits) /* We match the same number of bits */
985 /* No peers closer, we are the closest! */
991 * Select a peer from the routing table that would be a good routing
992 * destination for sending a message for "key". The resulting peer
993 * must not be in the set of blocked peers.<p>
995 * Note that we should not ALWAYS select the closest peer to the
996 * target, peers further away from the target should be chosen with
997 * exponentially declining probability.
999 * FIXME: double-check that this is fine
1002 * @param key the key we are selecting a peer to route to
1003 * @param bloom a bloomfilter containing entries this request has seen already
1004 * @param hops how many hops has this message traversed thus far
1005 * @return Peer to route to, or NULL on error
1007 static struct PeerInfo *
1008 select_peer (const GNUNET_HashCode *key,
1009 const struct GNUNET_CONTAINER_BloomFilter *bloom,
1014 unsigned int selected;
1015 struct PeerInfo *pos;
1017 unsigned int smallest_distance;
1018 struct PeerInfo *chosen;
1020 if (hops >= GDS_NSE_get ())
1022 /* greedy selection (closest peer that is not in bloomfilter) */
1023 smallest_distance = UINT_MAX;
1025 for (bc = 0; bc < closest_bucket; bc++)
1027 pos = k_buckets[bc].head;
1029 while ((pos != NULL) && (count < bucket_size))
1031 if ( (bloom == NULL) ||
1033 GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)) )
1035 dist = get_distance (key, &pos->id.hashPubKey);
1036 if (dist < smallest_distance)
1039 smallest_distance = dist;
1045 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1046 "Excluded peer `%s' due to BF match in greedy routing for %s\n",
1047 GNUNET_i2s (&pos->id),
1050 GNUNET_STATISTICS_update (GDS_stats,
1051 gettext_noop ("# Peers excluded from routing due to Bloomfilter"), 1,
1059 GNUNET_STATISTICS_update (GDS_stats,
1060 gettext_noop ("# Peer selection failed"), 1,
1065 /* select "random" peer */
1066 /* count number of peers that are available and not filtered */
1068 for (bc = 0; bc < closest_bucket; bc++)
1070 pos = k_buckets[bc].head;
1071 while ((pos != NULL) && (count < bucket_size))
1073 if ( (bloom != NULL) &&
1075 GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)) )
1077 GNUNET_STATISTICS_update (GDS_stats,
1078 gettext_noop ("# Peers excluded from routing due to Bloomfilter"), 1,
1081 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1082 "Excluded peer `%s' due to BF match in random routing for %s\n",
1083 GNUNET_i2s (&pos->id),
1087 continue; /* Ignore bloomfiltered peers */
1093 if (count == 0) /* No peers to select from! */
1095 GNUNET_STATISTICS_update (GDS_stats,
1096 gettext_noop ("# Peer selection failed"), 1,
1100 /* Now actually choose a peer */
1101 selected = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, count);
1103 for (bc = 0; bc < closest_bucket; bc++)
1105 pos = k_buckets[bc].head;
1106 while ((pos != NULL) && (count < bucket_size))
1108 if ( (bloom != NULL) &&
1110 GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)) )
1113 continue; /* Ignore bloomfiltered peers */
1115 if (0 == selected--)
1126 * Compute the set of peers that the given request should be
1129 * @param key routing key
1130 * @param bloom bloom filter excluding peers as targets, all selected
1131 * peers will be added to the bloom filter
1132 * @param hop_count number of hops the request has traversed so far
1133 * @param target_replication desired number of replicas
1134 * @param targets where to store an array of target peers (to be
1135 * free'd by the caller)
1136 * @return number of peers returned in 'targets'.
1139 get_target_peers (const GNUNET_HashCode *key,
1140 struct GNUNET_CONTAINER_BloomFilter *bloom,
1142 uint32_t target_replication,
1143 struct PeerInfo ***targets)
1147 struct PeerInfo **rtargets;
1148 struct PeerInfo *nxt;
1150 GNUNET_assert (NULL != bloom);
1151 ret = get_forward_count (hop_count, target_replication);
1157 rtargets = GNUNET_malloc (sizeof (struct PeerInfo*) * ret);
1158 for (off = 0; off < ret; off++)
1160 nxt = select_peer (key, bloom, hop_count);
1163 rtargets[off] = nxt;
1164 GNUNET_break (GNUNET_NO ==
1165 GNUNET_CONTAINER_bloomfilter_test (bloom, &nxt->id.hashPubKey));
1166 GNUNET_CONTAINER_bloomfilter_add (bloom, &rtargets[off]->id.hashPubKey);
1169 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1170 "Selected %u/%u peers at hop %u for %s (target was %u)\n",
1172 GNUNET_CONTAINER_multihashmap_size (all_known_peers),
1173 (unsigned int) hop_count,
1179 GNUNET_free (rtargets);
1183 *targets = rtargets;
1189 * Perform a PUT operation. Forwards the given request to other
1190 * peers. Does not store the data locally. Does not give the
1191 * data to local clients. May do nothing if this is the only
1192 * peer in the network (or if we are the closest peer in the
1195 * @param type type of the block
1196 * @param options routing options
1197 * @param desired_replication_level desired replication count
1198 * @param expiration_time when does the content expire
1199 * @param hop_count how many hops has this message traversed so far
1200 * @param bf Bloom filter of peers this PUT has already traversed
1201 * @param key key for the content
1202 * @param put_path_length number of entries in put_path
1203 * @param put_path peers this request has traversed so far (if tracked)
1204 * @param data payload to store
1205 * @param data_size number of bytes in data
1208 GDS_NEIGHBOURS_handle_put (enum GNUNET_BLOCK_Type type,
1209 enum GNUNET_DHT_RouteOption options,
1210 uint32_t desired_replication_level,
1211 struct GNUNET_TIME_Absolute expiration_time,
1213 struct GNUNET_CONTAINER_BloomFilter *bf,
1214 const GNUNET_HashCode *key,
1215 unsigned int put_path_length,
1216 struct GNUNET_PeerIdentity *put_path,
1220 unsigned int target_count;
1222 struct PeerInfo **targets;
1223 struct PeerInfo *target;
1224 struct P2PPendingMessage *pending;
1226 struct PeerPutMessage *ppm;
1227 struct GNUNET_PeerIdentity *pp;
1229 GNUNET_assert (NULL != bf);
1231 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1232 "Adding myself (%s) to PUT bloomfilter for %s\n",
1233 GNUNET_i2s (&my_identity),
1236 GNUNET_CONTAINER_bloomfilter_add (bf, &my_identity.hashPubKey);
1237 GNUNET_STATISTICS_update (GDS_stats,
1238 gettext_noop ("# PUT requests routed"), 1,
1240 target_count = get_target_peers (key, bf, hop_count,
1241 desired_replication_level,
1243 if (0 == target_count)
1246 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1247 "Routing PUT for %s terminates after %u hops at %s\n",
1249 (unsigned int) hop_count,
1250 GNUNET_i2s (&my_identity));
1254 msize = put_path_length * sizeof (struct GNUNET_PeerIdentity) + data_size + sizeof (struct PeerPutMessage);
1255 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1257 put_path_length = 0;
1258 msize = data_size + sizeof (struct PeerPutMessage);
1260 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1263 GNUNET_free (targets);
1266 GNUNET_STATISTICS_update (GDS_stats,
1267 gettext_noop ("# PUT messages queued for transmission"), target_count,
1269 for (i=0;i<target_count;i++)
1271 target = targets[i];
1273 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1274 "Routing PUT for %s after %u hops to %s\n",
1276 (unsigned int) hop_count,
1277 GNUNET_i2s (&target->id));
1279 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1280 pending->importance = 0; /* FIXME */
1281 pending->timeout = expiration_time;
1282 ppm = (struct PeerPutMessage*) &pending[1];
1283 pending->msg = &ppm->header;
1284 ppm->header.size = htons (msize);
1285 ppm->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_P2P_PUT);
1286 ppm->options = htonl (options);
1287 ppm->type = htonl (type);
1288 ppm->hop_count = htonl (hop_count + 1);
1289 ppm->desired_replication_level = htonl (desired_replication_level);
1290 ppm->put_path_length = htonl (put_path_length);
1291 ppm->expiration_time = GNUNET_TIME_absolute_hton (expiration_time);
1292 GNUNET_break (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (bf, &target->id.hashPubKey));
1293 GNUNET_assert (GNUNET_OK ==
1294 GNUNET_CONTAINER_bloomfilter_get_raw_data (bf,
1298 pp = (struct GNUNET_PeerIdentity*) &ppm[1];
1299 memcpy (pp, put_path, sizeof (struct GNUNET_PeerIdentity) * put_path_length);
1300 memcpy (&pp[put_path_length], data, data_size);
1301 GNUNET_CONTAINER_DLL_insert_tail (target->head,
1304 target->pending_count++;
1305 process_peer_queue (target);
1307 GNUNET_free (targets);
1312 * Perform a GET operation. Forwards the given request to other
1313 * peers. Does not lookup the key locally. May do nothing if this is
1314 * the only peer in the network (or if we are the closest peer in the
1317 * @param type type of the block
1318 * @param options routing options
1319 * @param desired_replication_level desired replication count
1320 * @param hop_count how many hops did this request traverse so far?
1321 * @param key key for the content
1322 * @param xquery extended query
1323 * @param xquery_size number of bytes in xquery
1324 * @param reply_bf bloomfilter to filter duplicates
1325 * @param reply_bf_mutator mutator for reply_bf
1326 * @param peer_bf filter for peers not to select (again)
1329 GDS_NEIGHBOURS_handle_get (enum GNUNET_BLOCK_Type type,
1330 enum GNUNET_DHT_RouteOption options,
1331 uint32_t desired_replication_level,
1333 const GNUNET_HashCode *key,
1336 const struct GNUNET_CONTAINER_BloomFilter *reply_bf,
1337 uint32_t reply_bf_mutator,
1338 struct GNUNET_CONTAINER_BloomFilter *peer_bf)
1340 unsigned int target_count;
1342 struct PeerInfo **targets;
1343 struct PeerInfo *target;
1344 struct P2PPendingMessage *pending;
1346 struct PeerGetMessage *pgm;
1348 size_t reply_bf_size;
1350 GNUNET_assert (NULL != peer_bf);
1351 GNUNET_STATISTICS_update (GDS_stats,
1352 gettext_noop ("# GET requests routed"), 1,
1354 target_count = get_target_peers (key, peer_bf, hop_count,
1355 desired_replication_level,
1358 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1359 "Adding myself (%s) to GET bloomfilter for %s\n",
1360 GNUNET_i2s (&my_identity),
1363 GNUNET_CONTAINER_bloomfilter_add (peer_bf, &my_identity.hashPubKey);
1364 if (0 == target_count)
1367 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1368 "Routing GET for %s terminates after %u hops at %s\n",
1370 (unsigned int) hop_count,
1371 GNUNET_i2s (&my_identity));
1375 reply_bf_size = GNUNET_CONTAINER_bloomfilter_get_size (reply_bf);
1376 msize = xquery_size + sizeof (struct PeerGetMessage) + reply_bf_size;
1377 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1380 GNUNET_free (targets);
1383 GNUNET_STATISTICS_update (GDS_stats,
1384 gettext_noop ("# GET messages queued for transmission"), target_count,
1386 /* forward request */
1387 for (i=0;i<target_count;i++)
1389 target = targets[i];
1391 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1392 "Routing GET for %s after %u hops to %s\n",
1394 (unsigned int) hop_count,
1395 GNUNET_i2s (&target->id));
1397 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1398 pending->importance = 0; /* FIXME */
1399 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1400 pgm = (struct PeerGetMessage*) &pending[1];
1401 pending->msg = &pgm->header;
1402 pgm->header.size = htons (msize);
1403 pgm->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_P2P_GET);
1404 pgm->options = htonl (options);
1405 pgm->type = htonl (type);
1406 pgm->hop_count = htonl (hop_count + 1);
1407 pgm->desired_replication_level = htonl (desired_replication_level);
1408 pgm->xquery_size = htonl (xquery_size);
1409 pgm->bf_mutator = reply_bf_mutator;
1410 GNUNET_break (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (peer_bf, &target->id.hashPubKey));
1411 GNUNET_assert (GNUNET_OK ==
1412 GNUNET_CONTAINER_bloomfilter_get_raw_data (peer_bf,
1416 xq = (char *) &pgm[1];
1417 memcpy (xq, xquery, xquery_size);
1418 if (NULL != reply_bf)
1419 GNUNET_assert (GNUNET_OK ==
1420 GNUNET_CONTAINER_bloomfilter_get_raw_data (reply_bf,
1423 GNUNET_CONTAINER_DLL_insert_tail (target->head,
1426 target->pending_count++;
1427 process_peer_queue (target);
1429 GNUNET_free (targets);
1434 * Handle a reply (route to origin). Only forwards the reply back to
1435 * the given peer. Does not do local caching or forwarding to local
1438 * @param target neighbour that should receive the block (if still connected)
1439 * @param type type of the block
1440 * @param expiration_time when does the content expire
1441 * @param key key for the content
1442 * @param put_path_length number of entries in put_path
1443 * @param put_path peers the original PUT traversed (if tracked)
1444 * @param get_path_length number of entries in put_path
1445 * @param get_path peers this reply has traversed so far (if tracked)
1446 * @param data payload of the reply
1447 * @param data_size number of bytes in data
1450 GDS_NEIGHBOURS_handle_reply (const struct GNUNET_PeerIdentity *target,
1451 enum GNUNET_BLOCK_Type type,
1452 struct GNUNET_TIME_Absolute expiration_time,
1453 const GNUNET_HashCode *key,
1454 unsigned int put_path_length,
1455 const struct GNUNET_PeerIdentity *put_path,
1456 unsigned int get_path_length,
1457 const struct GNUNET_PeerIdentity *get_path,
1461 struct PeerInfo *pi;
1462 struct P2PPendingMessage *pending;
1464 struct PeerResultMessage *prm;
1465 struct GNUNET_PeerIdentity *paths;
1467 msize = data_size + sizeof (struct PeerResultMessage) +
1468 (get_path_length + put_path_length) * sizeof (struct GNUNET_PeerIdentity);
1469 if ( (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
1470 (get_path_length > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) ||
1471 (put_path_length > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) ||
1472 (data_size > GNUNET_SERVER_MAX_MESSAGE_SIZE) )
1477 pi = GNUNET_CONTAINER_multihashmap_get (all_known_peers,
1478 &target->hashPubKey);
1481 /* peer disconnected in the meantime, drop reply */
1484 GNUNET_STATISTICS_update (GDS_stats,
1485 gettext_noop ("# RESULT messages queued for transmission"), 1,
1487 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1488 pending->importance = 0; /* FIXME */
1489 pending->timeout = expiration_time;
1490 prm = (struct PeerResultMessage*) &pending[1];
1491 pending->msg = &prm->header;
1492 prm->header.size = htons (msize);
1493 prm->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_P2P_RESULT);
1494 prm->type = htonl (type);
1495 prm->put_path_length = htonl (put_path_length);
1496 prm->get_path_length = htonl (get_path_length);
1497 prm->expiration_time = GNUNET_TIME_absolute_hton (expiration_time);
1499 paths = (struct GNUNET_PeerIdentity*) &prm[1];
1500 memcpy (paths, put_path, put_path_length * sizeof (struct GNUNET_PeerIdentity));
1501 memcpy (&paths[put_path_length],
1502 get_path, get_path_length * sizeof (struct GNUNET_PeerIdentity));
1503 memcpy (&paths[put_path_length + get_path_length],
1505 GNUNET_CONTAINER_DLL_insert (pi->head,
1508 pi->pending_count++;
1509 process_peer_queue (pi);
1514 * To be called on core init/fail.
1516 * @param cls service closure
1517 * @param server handle to the server for this service
1518 * @param identity the public identity of this peer
1521 core_init (void *cls, struct GNUNET_CORE_Handle *server,
1522 const struct GNUNET_PeerIdentity *identity)
1524 GNUNET_assert (server != NULL);
1525 my_identity = *identity;
1530 * Core handler for p2p put requests.
1532 * @param cls closure
1533 * @param peer sender of the request
1534 * @param message message
1535 * @param peer peer identity this notification is about
1536 * @param atsi performance data
1537 * @param atsi_count number of records in 'atsi'
1538 * @return GNUNET_OK to keep the connection open,
1539 * GNUNET_SYSERR to close it (signal serious error)
1542 handle_dht_p2p_put (void *cls,
1543 const struct GNUNET_PeerIdentity *peer,
1544 const struct GNUNET_MessageHeader *message,
1545 const struct GNUNET_ATS_Information
1547 unsigned int atsi_count)
1549 const struct PeerPutMessage *put;
1550 const struct GNUNET_PeerIdentity *put_path;
1551 const void *payload;
1554 size_t payload_size;
1555 enum GNUNET_DHT_RouteOption options;
1556 struct GNUNET_CONTAINER_BloomFilter *bf;
1557 GNUNET_HashCode test_key;
1559 msize = ntohs (message->size);
1560 if (msize < sizeof (struct PeerPutMessage))
1562 GNUNET_break_op (0);
1565 put = (const struct PeerPutMessage*) message;
1566 putlen = ntohl (put->put_path_length);
1567 if ( (msize < sizeof (struct PeerPutMessage) + putlen * sizeof (struct GNUNET_PeerIdentity)) ||
1568 (putlen > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) )
1570 GNUNET_break_op (0);
1573 GNUNET_STATISTICS_update (GDS_stats,
1574 gettext_noop ("# P2P PUT requests received"), 1,
1576 put_path = (const struct GNUNET_PeerIdentity*) &put[1];
1577 payload = &put_path[putlen];
1578 options = ntohl (put->options);
1579 payload_size = msize - (sizeof (struct PeerPutMessage) +
1580 putlen * sizeof (struct GNUNET_PeerIdentity));
1581 switch (GNUNET_BLOCK_get_key (GDS_block_context,
1583 payload, payload_size,
1587 if (0 != memcmp (&test_key, &put->key, sizeof (GNUNET_HashCode)))
1589 GNUNET_break_op (0);
1594 GNUNET_break_op (0);
1597 /* cannot verify, good luck */
1601 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1602 "PUT for %s at %s\n",
1603 GNUNET_h2s (&put->key),
1604 GNUNET_i2s (&my_identity));
1606 bf = GNUNET_CONTAINER_bloomfilter_init (put->bloomfilter,
1608 GNUNET_CONSTANTS_BLOOMFILTER_K);
1609 GNUNET_break_op (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (bf, &peer->hashPubKey));
1611 struct GNUNET_PeerIdentity pp[putlen+1];
1613 /* extend 'put path' by sender */
1614 if (0 != (options & GNUNET_DHT_RO_RECORD_ROUTE))
1616 memcpy (pp, put_path, putlen * sizeof (struct GNUNET_PeerIdentity));
1623 /* give to local clients */
1624 GDS_CLIENTS_handle_reply (GNUNET_TIME_absolute_ntoh (put->expiration_time),
1633 if ( (0 != (options & GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE)) ||
1634 (am_closest_peer (&put->key,
1636 GDS_DATACACHE_handle_put (GNUNET_TIME_absolute_ntoh (put->expiration_time),
1642 /* route to other peers */
1643 GDS_NEIGHBOURS_handle_put (ntohl (put->type),
1645 ntohl (put->desired_replication_level),
1646 GNUNET_TIME_absolute_ntoh (put->expiration_time),
1647 ntohl (put->hop_count),
1654 GNUNET_CONTAINER_bloomfilter_free (bf);
1660 * We have received a FIND PEER request. Send matching
1663 * @param sender sender of the FIND PEER request
1664 * @param key peers close to this key are desired
1665 * @param bf peers matching this bf are excluded
1666 * @param bf_mutator mutator for bf
1669 handle_find_peer (const struct GNUNET_PeerIdentity *sender,
1670 const GNUNET_HashCode *key,
1671 struct GNUNET_CONTAINER_BloomFilter *bf,
1672 uint32_t bf_mutator)
1675 struct PeerBucket *bucket;
1676 struct PeerInfo *peer;
1677 unsigned int choice;
1678 GNUNET_HashCode mhash;
1679 const struct GNUNET_HELLO_Message *hello;
1681 /* first, check about our own HELLO */
1682 if (NULL != GDS_my_hello)
1684 GNUNET_BLOCK_mingle_hash (&my_identity.hashPubKey, bf_mutator, &mhash);
1685 if ( (NULL == bf) ||
1686 (GNUNET_YES != GNUNET_CONTAINER_bloomfilter_test (bf, &mhash)) )
1688 GDS_NEIGHBOURS_handle_reply (sender,
1689 GNUNET_BLOCK_TYPE_DHT_HELLO,
1690 GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_HELLO_ADDRESS_EXPIRATION),
1695 GNUNET_HELLO_size ((const struct GNUNET_HELLO_Message*) GDS_my_hello));
1699 GNUNET_STATISTICS_update (GDS_stats,
1700 gettext_noop ("# FIND PEER requests ignored due to Bloomfilter"), 1,
1706 GNUNET_STATISTICS_update (GDS_stats,
1707 gettext_noop ("# FIND PEER requests ignored due to lack of HELLO"), 1,
1711 /* then, also consider sending a random HELLO from the closest bucket */
1712 if (0 == memcmp (&my_identity.hashPubKey, key, sizeof (GNUNET_HashCode)))
1713 bucket_idx = closest_bucket;
1715 bucket_idx = GNUNET_MIN (closest_bucket, find_bucket (key));
1716 if (bucket_idx == GNUNET_SYSERR)
1718 bucket = &k_buckets[bucket_idx];
1719 if (bucket->peers_size == 0)
1721 choice = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
1722 bucket->peers_size);
1723 peer = bucket->head;
1726 GNUNET_assert (peer != NULL);
1730 choice = bucket->peers_size;
1735 return; /* no non-masked peer available */
1737 peer = bucket->head;
1738 GNUNET_BLOCK_mingle_hash (&peer->id.hashPubKey, bf_mutator, &mhash);
1739 hello = GDS_HELLO_get (&peer->id);
1741 while ( (hello == NULL) ||
1742 (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (bf, &mhash)) );
1743 GDS_NEIGHBOURS_handle_reply (sender,
1744 GNUNET_BLOCK_TYPE_DHT_HELLO,
1745 GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_HELLO_ADDRESS_EXPIRATION),
1750 GNUNET_HELLO_size (hello));
1755 * Core handler for p2p get requests.
1757 * @param cls closure
1758 * @param peer sender of the request
1759 * @param message message
1760 * @param peer peer identity this notification is about
1761 * @param atsi performance data
1762 * @param atsi_count number of records in 'atsi'
1763 * @return GNUNET_OK to keep the connection open,
1764 * GNUNET_SYSERR to close it (signal serious error)
1767 handle_dht_p2p_get (void *cls, const struct GNUNET_PeerIdentity *peer,
1768 const struct GNUNET_MessageHeader *message,
1769 const struct GNUNET_ATS_Information
1771 unsigned int atsi_count)
1773 struct PeerGetMessage *get;
1774 uint32_t xquery_size;
1775 size_t reply_bf_size;
1777 enum GNUNET_BLOCK_Type type;
1778 enum GNUNET_DHT_RouteOption options;
1779 enum GNUNET_BLOCK_EvaluationResult eval;
1780 struct GNUNET_CONTAINER_BloomFilter *reply_bf;
1781 struct GNUNET_CONTAINER_BloomFilter *peer_bf;
1784 GNUNET_break (0 != memcmp (peer, &my_identity, sizeof (struct GNUNET_PeerIdentity)));
1785 /* parse and validate message */
1786 msize = ntohs (message->size);
1787 if (msize < sizeof (struct PeerGetMessage))
1789 GNUNET_break_op (0);
1792 get = (struct PeerGetMessage *) message;
1793 xquery_size = ntohl (get->xquery_size);
1794 if (msize < sizeof (struct PeerGetMessage) + xquery_size)
1796 GNUNET_break_op (0);
1799 GNUNET_STATISTICS_update (GDS_stats,
1800 gettext_noop ("# P2P GET requests received"), 1,
1802 reply_bf_size = msize - (sizeof (struct PeerGetMessage) + xquery_size);
1803 type = ntohl (get->type);
1804 options = ntohl (get->options);
1805 xquery = (const char*) &get[1];
1807 if (reply_bf_size > 0)
1808 reply_bf = GNUNET_CONTAINER_bloomfilter_init (&xquery[xquery_size],
1810 GNUNET_CONSTANTS_BLOOMFILTER_K);
1811 eval = GNUNET_BLOCK_evaluate (GDS_block_context,
1816 xquery, xquery_size,
1818 if (eval != GNUNET_BLOCK_EVALUATION_REQUEST_VALID)
1820 /* request invalid or block type not supported */
1821 GNUNET_break_op (eval == GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED);
1822 if (NULL != reply_bf)
1823 GNUNET_CONTAINER_bloomfilter_free (reply_bf);
1827 GNUNET_CONTAINER_bloomfilter_init (get->bloomfilter,
1829 GNUNET_CONSTANTS_BLOOMFILTER_K);
1830 GNUNET_break_op (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (peer_bf, &peer->hashPubKey));
1831 /* remember request for routing replies */
1832 GDS_ROUTING_add (peer,
1836 xquery, xquery_size,
1837 reply_bf, get->bf_mutator);
1839 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1840 "GET for %s at %s after %u hops\n",
1841 GNUNET_h2s (&get->key),
1842 GNUNET_i2s (&my_identity),
1843 (unsigned int) ntohl (get->hop_count));
1845 /* local lookup (this may update the reply_bf) */
1846 if ( (0 != (options & GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE)) ||
1847 (am_closest_peer (&get->key,
1850 if ( (0 != (options & GNUNET_DHT_RO_FIND_PEER)))
1852 GNUNET_STATISTICS_update (GDS_stats,
1853 gettext_noop ("# P2P FIND PEER requests processed"), 1,
1855 handle_find_peer (peer,
1862 eval = GDS_DATACACHE_handle_get (&get->key,
1864 xquery, xquery_size,
1871 GNUNET_STATISTICS_update (GDS_stats,
1872 gettext_noop ("# P2P GET requests ONLY routed"), 1,
1876 /* P2P forwarding */
1877 if (eval != GNUNET_BLOCK_EVALUATION_OK_LAST)
1878 GDS_NEIGHBOURS_handle_get (type,
1880 ntohl (get->desired_replication_level),
1881 ntohl (get->hop_count),
1883 xquery, xquery_size,
1888 if (NULL != reply_bf)
1889 GNUNET_CONTAINER_bloomfilter_free (reply_bf);
1890 GNUNET_CONTAINER_bloomfilter_free (peer_bf);
1896 * Core handler for p2p result messages.
1898 * @param cls closure
1899 * @param message message
1900 * @param peer peer identity this notification is about
1901 * @param atsi performance data
1902 * @param atsi_count number of records in 'atsi'
1903 * @return GNUNET_YES (do not cut p2p connection)
1906 handle_dht_p2p_result (void *cls, const struct GNUNET_PeerIdentity *peer,
1907 const struct GNUNET_MessageHeader *message,
1908 const struct GNUNET_ATS_Information
1910 unsigned int atsi_count)
1912 const struct PeerResultMessage *prm;
1913 const struct GNUNET_PeerIdentity *put_path;
1914 const struct GNUNET_PeerIdentity *get_path;
1916 uint32_t get_path_length;
1917 uint32_t put_path_length;
1920 enum GNUNET_BLOCK_Type type;
1922 /* parse and validate message */
1923 msize = ntohs (message->size);
1924 if (msize < sizeof (struct PeerResultMessage))
1926 GNUNET_break_op (0);
1929 prm = (struct PeerResultMessage *) message;
1930 put_path_length = ntohl (prm->put_path_length);
1931 get_path_length = ntohl (prm->get_path_length);
1932 if ( (msize < sizeof (struct PeerResultMessage) +
1933 (get_path_length + put_path_length) * sizeof (struct GNUNET_PeerIdentity)) ||
1934 (get_path_length > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) ||
1935 (put_path_length > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) )
1937 GNUNET_break_op (0);
1940 GNUNET_STATISTICS_update (GDS_stats,
1941 gettext_noop ("# P2P RESULTS received"), 1,
1943 put_path = (const struct GNUNET_PeerIdentity*) &prm[1];
1944 get_path = &put_path[put_path_length];
1945 type = ntohl (prm->type);
1946 data = (const void*) &get_path[get_path_length];
1947 data_size = msize - (sizeof (struct PeerResultMessage) +
1948 (get_path_length + put_path_length) * sizeof (struct GNUNET_PeerIdentity));
1950 /* if we got a HELLO, consider it for our own routing table */
1951 if (type == GNUNET_BLOCK_TYPE_DHT_HELLO)
1953 const struct GNUNET_MessageHeader *h;
1954 struct GNUNET_PeerIdentity pid;
1957 /* Should be a HELLO, validate and consider using it! */
1958 if (data_size < sizeof (struct GNUNET_MessageHeader))
1960 GNUNET_break_op (0);
1964 if (data_size != ntohs (h->size))
1966 GNUNET_break_op (0);
1970 GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message*) h,
1973 GNUNET_break_op (0);
1976 if (0 != memcmp (&my_identity, &pid, sizeof (struct GNUNET_PeerIdentity)))
1978 bucket = find_bucket (&pid.hashPubKey);
1979 if ( (bucket >= 0) &&
1980 (k_buckets[bucket].peers_size < bucket_size) )
1982 if (NULL != GDS_transport_handle)
1984 GNUNET_TRANSPORT_offer_hello (GDS_transport_handle,
1986 GNUNET_TRANSPORT_try_connect (GDS_transport_handle,
1993 /* append 'peer' to 'get_path' */
1995 struct GNUNET_PeerIdentity xget_path[get_path_length+1];
1997 memcpy (xget_path, get_path, get_path_length * sizeof (struct GNUNET_PeerIdentity));
1998 xget_path[get_path_length] = *peer;
2001 /* forward to local clients */
2002 GDS_CLIENTS_handle_reply (GNUNET_TIME_absolute_ntoh (prm->expiration_time),
2012 /* forward to other peers */
2013 GDS_ROUTING_process (type,
2014 GNUNET_TIME_absolute_ntoh (prm->expiration_time),
2028 * Initialize neighbours subsystem.
2030 * @return GNUNET_OK on success, GNUNET_SYSERR on error
2033 GDS_NEIGHBOURS_init ()
2035 static struct GNUNET_CORE_MessageHandler core_handlers[] = {
2036 {&handle_dht_p2p_get, GNUNET_MESSAGE_TYPE_DHT_P2P_GET, 0},
2037 {&handle_dht_p2p_put, GNUNET_MESSAGE_TYPE_DHT_P2P_PUT, 0},
2038 {&handle_dht_p2p_result, GNUNET_MESSAGE_TYPE_DHT_P2P_RESULT, 0},
2041 unsigned long long temp_config_num;
2044 GNUNET_CONFIGURATION_get_value_number (GDS_cfg, "DHT", "bucket_size",
2046 bucket_size = (unsigned int) temp_config_num;
2047 atsAPI = GNUNET_ATS_performance_init (GDS_cfg, NULL, NULL);
2048 coreAPI = GNUNET_CORE_connect (GDS_cfg,
2052 &handle_core_connect,
2053 &handle_core_disconnect,
2057 if (coreAPI == NULL)
2058 return GNUNET_SYSERR;
2059 all_known_peers = GNUNET_CONTAINER_multihashmap_create (256);
2065 * Shutdown neighbours subsystem.
2068 GDS_NEIGHBOURS_done ()
2070 if (coreAPI == NULL)
2072 GNUNET_CORE_disconnect (coreAPI);
2074 GNUNET_ATS_performance_done (atsAPI);
2076 GNUNET_assert (0 == GNUNET_CONTAINER_multihashmap_size (all_known_peers));
2077 GNUNET_CONTAINER_multihashmap_destroy (all_known_peers);
2078 all_known_peers = NULL;
2079 if (GNUNET_SCHEDULER_NO_TASK != find_peer_task)
2081 GNUNET_SCHEDULER_cancel (find_peer_task);
2082 find_peer_task = GNUNET_SCHEDULER_NO_TASK;
2087 /* end of gnunet-service-dht_neighbours.c */