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_CONTAINER_DLL_remove (k_buckets[current_bucket].head,
744 k_buckets[current_bucket].tail,
746 GNUNET_assert (k_buckets[current_bucket].peers_size > 0);
747 k_buckets[current_bucket].peers_size--;
748 while ( (closest_bucket > 0) &&
749 (k_buckets[closest_bucket].peers_size == 0) )
752 if (to_remove->th != NULL)
754 GNUNET_CORE_notify_transmit_ready_cancel (to_remove->th);
755 to_remove->th = NULL;
758 while (NULL != (pos = to_remove->head))
760 GNUNET_CONTAINER_DLL_remove (to_remove->head,
766 GNUNET_STATISTICS_update (GDS_stats,
767 gettext_noop ("# Queued messages discarded (peer disconnected)"), discarded,
769 GNUNET_free (to_remove);
774 * Called when core is ready to send a message we asked for
775 * out to the destination.
777 * @param cls the 'struct PeerInfo' of the target peer
778 * @param size number of bytes available in buf
779 * @param buf where the callee should write the message
780 * @return number of bytes written to buf
783 core_transmit_notify (void *cls, size_t size, void *buf)
785 struct PeerInfo *peer = cls;
787 struct P2PPendingMessage *pending;
792 while ( (NULL != (pending = peer->head)) &&
793 (GNUNET_TIME_absolute_get_remaining (pending->timeout).rel_value == 0) )
795 peer->pending_count--;
796 GNUNET_CONTAINER_DLL_remove (peer->head, peer->tail, pending);
797 GNUNET_free (pending);
801 /* no messages pending */
807 = GNUNET_CORE_notify_transmit_ready (coreAPI, GNUNET_YES,
809 GNUNET_TIME_absolute_get_remaining (pending->timeout),
810 &peer->id, ntohs (pending->msg->size),
811 &core_transmit_notify, peer);
812 GNUNET_break (NULL != peer->th);
816 while ( (NULL != (pending = peer->head)) &&
817 (size - off >= (msize = ntohs (pending->msg->size))) )
819 GNUNET_STATISTICS_update (GDS_stats,
820 gettext_noop ("# Bytes transmitted to other peers"), msize,
822 memcpy (&cbuf[off], pending->msg, msize);
824 peer->pending_count--;
825 GNUNET_CONTAINER_DLL_remove (peer->head, peer->tail, pending);
826 GNUNET_free (pending);
828 if (peer->head != NULL)
831 = GNUNET_CORE_notify_transmit_ready (coreAPI, GNUNET_YES,
833 GNUNET_TIME_absolute_get_remaining (pending->timeout),
835 &core_transmit_notify, peer);
836 GNUNET_break (NULL != peer->th);
843 * Transmit all messages in the peer's message queue.
845 * @param peer message queue to process
848 process_peer_queue (struct PeerInfo *peer)
850 struct P2PPendingMessage *pending;
852 if (NULL == (pending = peer->head))
854 if (NULL != peer->th)
856 GNUNET_STATISTICS_update (GDS_stats,
857 gettext_noop ("# Bytes of bandwdith requested from core"),
858 ntohs (pending->msg->size),
861 = GNUNET_CORE_notify_transmit_ready (coreAPI, GNUNET_YES,
863 GNUNET_TIME_absolute_get_remaining (pending->timeout),
865 ntohs (pending->msg->size),
866 &core_transmit_notify, peer);
867 GNUNET_break (NULL != peer->th);
872 * To how many peers should we (on average) forward the request to
873 * obtain the desired target_replication count (on average).
875 * @param hop_count number of hops the message has traversed
876 * @param target_replication the number of total paths desired
877 * @return Some number of peers to forward the message to
880 get_forward_count (uint32_t hop_count,
881 uint32_t target_replication)
883 uint32_t random_value;
884 uint32_t forward_count;
887 if (hop_count > GDS_NSE_get () * 6.0)
889 /* forcefully terminate */
892 if (hop_count > GDS_NSE_get () * 4.0)
894 /* Once we have reached our ideal number of hops, only forward to 1 peer */
897 /* bound by system-wide maximum */
898 target_replication = GNUNET_MIN (MAXIMUM_REPLICATION_LEVEL,
901 1 + (target_replication - 1.0) / (GDS_NSE_get () +
902 ((float) (target_replication - 1.0) *
904 /* Set forward count to floor of target_value */
905 forward_count = (uint32_t) target_value;
906 /* Subtract forward_count (floor) from target_value (yields value between 0 and 1) */
907 target_value = target_value - forward_count;
909 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, UINT32_MAX);
910 if (random_value < (target_value * UINT32_MAX))
912 return forward_count;
917 * Compute the distance between have and target as a 32-bit value.
918 * Differences in the lower bits must count stronger than differences
919 * in the higher bits.
921 * @return 0 if have==target, otherwise a number
922 * that is larger as the distance between
923 * the two hash codes increases
926 get_distance (const GNUNET_HashCode * target, const GNUNET_HashCode * have)
933 /* We have to represent the distance between two 2^9 (=512)-bit
934 * numbers as a 2^5 (=32)-bit number with "0" being used for the
935 * two numbers being identical; furthermore, we need to
936 * guarantee that a difference in the number of matching
937 * bits is always represented in the result.
939 * We use 2^32/2^9 numerical values to distinguish between
940 * hash codes that have the same LSB bit distance and
941 * use the highest 2^9 bits of the result to signify the
942 * number of (mis)matching LSB bits; if we have 0 matching
943 * and hence 512 mismatching LSB bits we return -1 (since
944 * 512 itself cannot be represented with 9 bits) */
946 /* first, calculate the most significant 9 bits of our
947 * result, aka the number of LSBs */
948 bucket = GNUNET_CRYPTO_hash_matching_bits (target, have);
949 /* bucket is now a value between 0 and 512 */
951 return 0; /* perfect match */
953 return (unsigned int) -1; /* LSB differs; use max (if we did the bit-shifting
954 * below, we'd end up with max+1 (overflow)) */
956 /* calculate the most significant bits of the final result */
957 msb = (512 - bucket) << (32 - 9);
958 /* calculate the 32-9 least significant bits of the final result by
959 * looking at the differences in the 32-9 bits following the
960 * mismatching bit at 'bucket' */
963 (i < sizeof (GNUNET_HashCode) * 8) && (i < bucket + 1 + 32 - 9); i++)
965 if (GNUNET_CRYPTO_hash_get_bit (target, i) !=
966 GNUNET_CRYPTO_hash_get_bit (have, i))
967 lsb |= (1 << (bucket + 32 - 9 - i)); /* first bit set will be 10,
968 * last bit set will be 31 -- if
969 * i does not reach 512 first... */
976 * Check whether my identity is closer than any known peers. If a
977 * non-null bloomfilter is given, check if this is the closest peer
978 * that hasn't already been routed to.
980 * @param key hash code to check closeness to
981 * @param bloom bloomfilter, exclude these entries from the decision
982 * @return GNUNET_YES if node location is closest,
983 * GNUNET_NO otherwise.
986 am_closest_peer (const GNUNET_HashCode *key,
987 const struct GNUNET_CONTAINER_BloomFilter *bloom)
993 struct PeerInfo *pos;
995 if (0 == memcmp (&my_identity.hashPubKey, key, sizeof (GNUNET_HashCode)))
997 bucket_num = find_bucket (key);
998 bits = GNUNET_CRYPTO_hash_matching_bits (&my_identity.hashPubKey, key);
999 pos = k_buckets[bucket_num].head;
1001 while ((pos != NULL) && (count < bucket_size))
1003 if ((bloom != NULL) &&
1005 GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)))
1008 continue; /* Skip already checked entries */
1010 other_bits = GNUNET_CRYPTO_hash_matching_bits (&pos->id.hashPubKey, key);
1011 if (other_bits > bits)
1013 if (other_bits == bits) /* We match the same number of bits */
1017 /* No peers closer, we are the closest! */
1023 * Select a peer from the routing table that would be a good routing
1024 * destination for sending a message for "key". The resulting peer
1025 * must not be in the set of blocked peers.<p>
1027 * Note that we should not ALWAYS select the closest peer to the
1028 * target, peers further away from the target should be chosen with
1029 * exponentially declining probability.
1031 * FIXME: double-check that this is fine
1034 * @param key the key we are selecting a peer to route to
1035 * @param bloom a bloomfilter containing entries this request has seen already
1036 * @param hops how many hops has this message traversed thus far
1037 * @return Peer to route to, or NULL on error
1039 static struct PeerInfo *
1040 select_peer (const GNUNET_HashCode *key,
1041 const struct GNUNET_CONTAINER_BloomFilter *bloom,
1046 unsigned int selected;
1047 struct PeerInfo *pos;
1049 unsigned int smallest_distance;
1050 struct PeerInfo *chosen;
1052 if (hops >= GDS_NSE_get ())
1054 /* greedy selection (closest peer that is not in bloomfilter) */
1055 smallest_distance = UINT_MAX;
1057 for (bc = 0; bc < closest_bucket; bc++)
1059 pos = k_buckets[bc].head;
1061 while ((pos != NULL) && (count < bucket_size))
1063 if ( (bloom == NULL) ||
1065 GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)) )
1067 dist = get_distance (key, &pos->id.hashPubKey);
1068 if (dist < smallest_distance)
1071 smallest_distance = dist;
1076 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1077 "Excluded peer `%s' due to BF match in greedy routing for %s\n",
1078 GNUNET_i2s (&pos->id),
1080 GNUNET_STATISTICS_update (GDS_stats,
1081 gettext_noop ("# Peers excluded from routing due to Bloomfilter"), 1,
1089 GNUNET_STATISTICS_update (GDS_stats,
1090 gettext_noop ("# Peer selection failed"), 1,
1095 /* select "random" peer */
1096 /* count number of peers that are available and not filtered */
1098 for (bc = closest_bucket; bc < MAX_BUCKETS; bc++)
1100 pos = k_buckets[bc].head;
1101 while ((pos != NULL) && (count < bucket_size))
1103 if ( (bloom != NULL) &&
1105 GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)) )
1107 GNUNET_STATISTICS_update (GDS_stats,
1108 gettext_noop ("# Peers excluded from routing due to Bloomfilter"), 1,
1110 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1111 "Excluded peer `%s' due to BF match in random routing for %s\n",
1112 GNUNET_i2s (&pos->id),
1115 continue; /* Ignore bloomfiltered peers */
1121 if (count == 0) /* No peers to select from! */
1123 GNUNET_STATISTICS_update (GDS_stats,
1124 gettext_noop ("# Peer selection failed"), 1,
1128 /* Now actually choose a peer */
1129 selected = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, count);
1131 for (bc = closest_bucket; bc < MAX_BUCKETS; bc++)
1133 pos = k_buckets[bc].head;
1134 while ((pos != NULL) && (count < bucket_size))
1136 if ( (bloom != NULL) &&
1138 GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)) )
1141 continue; /* Ignore bloomfiltered peers */
1143 if (0 == selected--)
1154 * Compute the set of peers that the given request should be
1157 * @param key routing key
1158 * @param bloom bloom filter excluding peers as targets, all selected
1159 * peers will be added to the bloom filter
1160 * @param hop_count number of hops the request has traversed so far
1161 * @param target_replication desired number of replicas
1162 * @param targets where to store an array of target peers (to be
1163 * free'd by the caller)
1164 * @return number of peers returned in 'targets'.
1167 get_target_peers (const GNUNET_HashCode *key,
1168 struct GNUNET_CONTAINER_BloomFilter *bloom,
1170 uint32_t target_replication,
1171 struct PeerInfo ***targets)
1175 struct PeerInfo **rtargets;
1176 struct PeerInfo *nxt;
1178 GNUNET_assert (NULL != bloom);
1179 ret = get_forward_count (hop_count, target_replication);
1185 rtargets = GNUNET_malloc (sizeof (struct PeerInfo*) * ret);
1186 for (off = 0; off < ret; off++)
1188 nxt = select_peer (key, bloom, hop_count);
1191 rtargets[off] = nxt;
1192 GNUNET_break (GNUNET_NO ==
1193 GNUNET_CONTAINER_bloomfilter_test (bloom, &nxt->id.hashPubKey));
1194 GNUNET_CONTAINER_bloomfilter_add (bloom, &rtargets[off]->id.hashPubKey);
1196 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1197 "Selected %u/%u peers at hop %u for %s (target was %u)\n",
1199 GNUNET_CONTAINER_multihashmap_size (all_known_peers),
1200 (unsigned int) hop_count,
1205 GNUNET_free (rtargets);
1209 *targets = rtargets;
1215 * Perform a PUT operation. Forwards the given request to other
1216 * peers. Does not store the data locally. Does not give the
1217 * data to local clients. May do nothing if this is the only
1218 * peer in the network (or if we are the closest peer in the
1221 * @param type type of the block
1222 * @param options routing options
1223 * @param desired_replication_level desired replication count
1224 * @param expiration_time when does the content expire
1225 * @param hop_count how many hops has this message traversed so far
1226 * @param bf Bloom filter of peers this PUT has already traversed
1227 * @param key key for the content
1228 * @param put_path_length number of entries in put_path
1229 * @param put_path peers this request has traversed so far (if tracked)
1230 * @param data payload to store
1231 * @param data_size number of bytes in data
1234 GDS_NEIGHBOURS_handle_put (enum GNUNET_BLOCK_Type type,
1235 enum GNUNET_DHT_RouteOption options,
1236 uint32_t desired_replication_level,
1237 struct GNUNET_TIME_Absolute expiration_time,
1239 struct GNUNET_CONTAINER_BloomFilter *bf,
1240 const GNUNET_HashCode *key,
1241 unsigned int put_path_length,
1242 struct GNUNET_PeerIdentity *put_path,
1246 unsigned int target_count;
1248 struct PeerInfo **targets;
1249 struct PeerInfo *target;
1250 struct P2PPendingMessage *pending;
1252 struct PeerPutMessage *ppm;
1253 struct GNUNET_PeerIdentity *pp;
1255 GNUNET_assert (NULL != bf);
1256 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1257 "Adding myself (%s) to PUT bloomfilter for %s\n",
1258 GNUNET_i2s (&my_identity),
1260 GNUNET_CONTAINER_bloomfilter_add (bf, &my_identity.hashPubKey);
1261 GNUNET_STATISTICS_update (GDS_stats,
1262 gettext_noop ("# PUT requests routed"), 1,
1264 target_count = get_target_peers (key, bf, hop_count,
1265 desired_replication_level,
1267 if (0 == target_count)
1269 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1270 "Routing PUT for %s terminates after %u hops at %s\n",
1272 (unsigned int) hop_count,
1273 GNUNET_i2s (&my_identity));
1276 msize = put_path_length * sizeof (struct GNUNET_PeerIdentity) + data_size + sizeof (struct PeerPutMessage);
1277 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1279 put_path_length = 0;
1280 msize = data_size + sizeof (struct PeerPutMessage);
1282 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1287 GNUNET_STATISTICS_update (GDS_stats,
1288 gettext_noop ("# PUT messages queued for transmission"), target_count,
1290 for (i=0;i<target_count;i++)
1292 target = targets[i];
1293 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1294 "Routing PUT for %s after %u hops to %s\n",
1296 (unsigned int) hop_count,
1297 GNUNET_i2s (&target->id));
1298 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1299 pending->importance = 0; /* FIXME */
1300 pending->timeout = expiration_time;
1301 ppm = (struct PeerPutMessage*) &pending[1];
1302 pending->msg = &ppm->header;
1303 ppm->header.size = htons (msize);
1304 ppm->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_P2P_PUT);
1305 ppm->options = htonl (options);
1306 ppm->type = htonl (type);
1307 ppm->hop_count = htonl (hop_count + 1);
1308 ppm->desired_replication_level = htonl (desired_replication_level);
1309 ppm->put_path_length = htonl (put_path_length);
1310 ppm->expiration_time = GNUNET_TIME_absolute_hton (expiration_time);
1311 GNUNET_break (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (bf, &target->id.hashPubKey));
1312 GNUNET_assert (GNUNET_OK ==
1313 GNUNET_CONTAINER_bloomfilter_get_raw_data (bf,
1317 pp = (struct GNUNET_PeerIdentity*) &ppm[1];
1318 memcpy (pp, put_path, sizeof (struct GNUNET_PeerIdentity) * put_path_length);
1319 memcpy (&pp[put_path_length], data, data_size);
1320 GNUNET_CONTAINER_DLL_insert_tail (target->head,
1323 target->pending_count++;
1324 process_peer_queue (target);
1326 GNUNET_free (targets);
1331 * Perform a GET operation. Forwards the given request to other
1332 * peers. Does not lookup the key locally. May do nothing if this is
1333 * the only peer in the network (or if we are the closest peer in the
1336 * @param type type of the block
1337 * @param options routing options
1338 * @param desired_replication_level desired replication count
1339 * @param hop_count how many hops did this request traverse so far?
1340 * @param key key for the content
1341 * @param xquery extended query
1342 * @param xquery_size number of bytes in xquery
1343 * @param reply_bf bloomfilter to filter duplicates
1344 * @param reply_bf_mutator mutator for reply_bf
1345 * @param peer_bf filter for peers not to select (again)
1348 GDS_NEIGHBOURS_handle_get (enum GNUNET_BLOCK_Type type,
1349 enum GNUNET_DHT_RouteOption options,
1350 uint32_t desired_replication_level,
1352 const GNUNET_HashCode *key,
1355 const struct GNUNET_CONTAINER_BloomFilter *reply_bf,
1356 uint32_t reply_bf_mutator,
1357 struct GNUNET_CONTAINER_BloomFilter *peer_bf)
1359 unsigned int target_count;
1361 struct PeerInfo **targets;
1362 struct PeerInfo *target;
1363 struct P2PPendingMessage *pending;
1365 struct PeerGetMessage *pgm;
1367 size_t reply_bf_size;
1369 GNUNET_assert (NULL != peer_bf);
1370 GNUNET_STATISTICS_update (GDS_stats,
1371 gettext_noop ("# GET requests routed"), 1,
1373 target_count = get_target_peers (key, peer_bf, hop_count,
1374 desired_replication_level,
1376 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1377 "Adding myself (%s) to GET bloomfilter for %s\n",
1378 GNUNET_i2s (&my_identity),
1380 GNUNET_CONTAINER_bloomfilter_add (peer_bf, &my_identity.hashPubKey);
1381 if (0 == target_count)
1383 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1384 "Routing GET for %s terminates after %u hops at %s\n",
1386 (unsigned int) hop_count,
1387 GNUNET_i2s (&my_identity));
1390 reply_bf_size = GNUNET_CONTAINER_bloomfilter_get_size (reply_bf);
1391 msize = xquery_size + sizeof (struct PeerGetMessage) + reply_bf_size;
1392 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1397 GNUNET_STATISTICS_update (GDS_stats,
1398 gettext_noop ("# GET messages queued for transmission"), target_count,
1400 /* forward request */
1401 for (i=0;i<target_count;i++)
1403 target = targets[i];
1404 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1405 "Routing GET for %s after %u hops to %s\n",
1407 (unsigned int) hop_count,
1408 GNUNET_i2s (&target->id));
1409 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1410 pending->importance = 0; /* FIXME */
1411 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1412 pgm = (struct PeerGetMessage*) &pending[1];
1413 pending->msg = &pgm->header;
1414 pgm->header.size = htons (msize);
1415 pgm->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_P2P_GET);
1416 pgm->options = htonl (options);
1417 pgm->type = htonl (type);
1418 pgm->hop_count = htonl (hop_count + 1);
1419 pgm->desired_replication_level = htonl (desired_replication_level);
1420 pgm->xquery_size = htonl (xquery_size);
1421 pgm->bf_mutator = reply_bf_mutator;
1422 GNUNET_break (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (peer_bf, &target->id.hashPubKey));
1423 GNUNET_assert (GNUNET_OK ==
1424 GNUNET_CONTAINER_bloomfilter_get_raw_data (peer_bf,
1428 xq = (char *) &pgm[1];
1429 memcpy (xq, xquery, xquery_size);
1430 if (NULL != reply_bf)
1431 GNUNET_assert (GNUNET_OK ==
1432 GNUNET_CONTAINER_bloomfilter_get_raw_data (reply_bf,
1435 GNUNET_CONTAINER_DLL_insert_tail (target->head,
1438 target->pending_count++;
1439 process_peer_queue (target);
1441 GNUNET_free (targets);
1446 * Handle a reply (route to origin). Only forwards the reply back to
1447 * the given peer. Does not do local caching or forwarding to local
1450 * @param target neighbour that should receive the block (if still connected)
1451 * @param type type of the block
1452 * @param expiration_time when does the content expire
1453 * @param key key for the content
1454 * @param put_path_length number of entries in put_path
1455 * @param put_path peers the original PUT traversed (if tracked)
1456 * @param get_path_length number of entries in put_path
1457 * @param get_path peers this reply has traversed so far (if tracked)
1458 * @param data payload of the reply
1459 * @param data_size number of bytes in data
1462 GDS_NEIGHBOURS_handle_reply (const struct GNUNET_PeerIdentity *target,
1463 enum GNUNET_BLOCK_Type type,
1464 struct GNUNET_TIME_Absolute expiration_time,
1465 const GNUNET_HashCode *key,
1466 unsigned int put_path_length,
1467 const struct GNUNET_PeerIdentity *put_path,
1468 unsigned int get_path_length,
1469 const struct GNUNET_PeerIdentity *get_path,
1473 struct PeerInfo *pi;
1474 struct P2PPendingMessage *pending;
1476 struct PeerResultMessage *prm;
1477 struct GNUNET_PeerIdentity *paths;
1479 msize = data_size + sizeof (struct PeerResultMessage) +
1480 (get_path_length + put_path_length) * sizeof (struct GNUNET_PeerIdentity);
1481 if ( (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
1482 (get_path_length > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) ||
1483 (put_path_length > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) ||
1484 (data_size > GNUNET_SERVER_MAX_MESSAGE_SIZE) )
1489 pi = GNUNET_CONTAINER_multihashmap_get (all_known_peers,
1490 &target->hashPubKey);
1493 /* peer disconnected in the meantime, drop reply */
1496 GNUNET_STATISTICS_update (GDS_stats,
1497 gettext_noop ("# RESULT messages queued for transmission"), 1,
1499 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1500 pending->importance = 0; /* FIXME */
1501 pending->timeout = expiration_time;
1502 prm = (struct PeerResultMessage*) &pending[1];
1503 pending->msg = &prm->header;
1504 prm->header.size = htons (msize);
1505 prm->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_P2P_RESULT);
1506 prm->type = htonl (type);
1507 prm->put_path_length = htonl (put_path_length);
1508 prm->get_path_length = htonl (get_path_length);
1509 prm->expiration_time = GNUNET_TIME_absolute_hton (expiration_time);
1511 paths = (struct GNUNET_PeerIdentity*) &prm[1];
1512 memcpy (paths, put_path, put_path_length * sizeof (struct GNUNET_PeerIdentity));
1513 memcpy (&paths[put_path_length],
1514 get_path, get_path_length * sizeof (struct GNUNET_PeerIdentity));
1515 memcpy (&paths[put_path_length + get_path_length],
1517 GNUNET_CONTAINER_DLL_insert (pi->head,
1520 pi->pending_count++;
1521 process_peer_queue (pi);
1526 * To be called on core init/fail.
1528 * @param cls service closure
1529 * @param server handle to the server for this service
1530 * @param identity the public identity of this peer
1533 core_init (void *cls, struct GNUNET_CORE_Handle *server,
1534 const struct GNUNET_PeerIdentity *identity)
1536 GNUNET_assert (server != NULL);
1537 my_identity = *identity;
1542 * Core handler for p2p put requests.
1544 * @param cls closure
1545 * @param peer sender of the request
1546 * @param message message
1547 * @param peer peer identity this notification is about
1548 * @param atsi performance data
1549 * @return GNUNET_OK to keep the connection open,
1550 * GNUNET_SYSERR to close it (signal serious error)
1553 handle_dht_p2p_put (void *cls,
1554 const struct GNUNET_PeerIdentity *peer,
1555 const struct GNUNET_MessageHeader *message,
1556 const struct GNUNET_TRANSPORT_ATS_Information
1559 const struct PeerPutMessage *put;
1560 const struct GNUNET_PeerIdentity *put_path;
1561 const void *payload;
1564 size_t payload_size;
1565 enum GNUNET_DHT_RouteOption options;
1566 struct GNUNET_CONTAINER_BloomFilter *bf;
1567 GNUNET_HashCode test_key;
1569 msize = ntohs (message->size);
1570 if (msize < sizeof (struct PeerPutMessage))
1572 GNUNET_break_op (0);
1575 put = (const struct PeerPutMessage*) message;
1576 putlen = ntohl (put->put_path_length);
1577 if ( (msize < sizeof (struct PeerPutMessage) + putlen * sizeof (struct GNUNET_PeerIdentity)) ||
1578 (putlen > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) )
1580 GNUNET_break_op (0);
1583 GNUNET_STATISTICS_update (GDS_stats,
1584 gettext_noop ("# P2P PUT requests received"), 1,
1586 put_path = (const struct GNUNET_PeerIdentity*) &put[1];
1587 payload = &put_path[putlen];
1588 options = ntohl (put->options);
1589 payload_size = msize - (sizeof (struct PeerPutMessage) +
1590 putlen * sizeof (struct GNUNET_PeerIdentity));
1591 switch (GNUNET_BLOCK_get_key (GDS_block_context,
1593 payload, payload_size,
1597 if (0 != memcmp (&test_key, &put->key, sizeof (GNUNET_HashCode)))
1599 GNUNET_break_op (0);
1604 GNUNET_break_op (0);
1607 /* cannot verify, good luck */
1610 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1611 "PUT for %s at %s\n",
1612 GNUNET_h2s (&put->key),
1613 GNUNET_i2s (&my_identity));
1614 bf = GNUNET_CONTAINER_bloomfilter_init (put->bloomfilter,
1616 GNUNET_CONSTANTS_BLOOMFILTER_K);
1617 GNUNET_break_op (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (bf, &peer->hashPubKey));
1619 struct GNUNET_PeerIdentity pp[putlen+1];
1621 /* extend 'put path' by sender */
1622 if (0 != (options & GNUNET_DHT_RO_RECORD_ROUTE))
1624 memcpy (pp, put_path, putlen * sizeof (struct GNUNET_PeerIdentity));
1631 /* give to local clients */
1632 GDS_CLIENTS_handle_reply (GNUNET_TIME_absolute_ntoh (put->expiration_time),
1641 if ( (0 != (options & GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE)) ||
1642 (am_closest_peer (&put->key,
1644 GDS_DATACACHE_handle_put (GNUNET_TIME_absolute_ntoh (put->expiration_time),
1650 /* route to other peers */
1651 GDS_NEIGHBOURS_handle_put (ntohl (put->type),
1653 ntohl (put->desired_replication_level),
1654 GNUNET_TIME_absolute_ntoh (put->expiration_time),
1655 ntohl (put->hop_count),
1662 GNUNET_CONTAINER_bloomfilter_free (bf);
1668 * We have received a FIND PEER request. Send matching
1671 * @param sender sender of the FIND PEER request
1672 * @param key peers close to this key are desired
1673 * @param bf peers matching this bf are excluded
1674 * @param bf_mutator mutator for bf
1677 handle_find_peer (const struct GNUNET_PeerIdentity *sender,
1678 const GNUNET_HashCode *key,
1679 struct GNUNET_CONTAINER_BloomFilter *bf,
1680 uint32_t bf_mutator)
1683 struct PeerBucket *bucket;
1684 struct PeerInfo *peer;
1685 unsigned int choice;
1686 GNUNET_HashCode mhash;
1687 const struct GNUNET_HELLO_Message *hello;
1689 /* first, check about our own HELLO */
1690 if (NULL != GDS_my_hello)
1692 GNUNET_BLOCK_mingle_hash (&my_identity.hashPubKey, bf_mutator, &mhash);
1693 if ( (NULL == bf) ||
1694 (GNUNET_YES != GNUNET_CONTAINER_bloomfilter_test (bf, &mhash)) )
1696 GDS_NEIGHBOURS_handle_reply (sender,
1697 GNUNET_BLOCK_TYPE_DHT_HELLO,
1698 GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_HELLO_ADDRESS_EXPIRATION),
1703 GNUNET_HELLO_size ((const struct GNUNET_HELLO_Message*) GDS_my_hello));
1707 GNUNET_STATISTICS_update (GDS_stats,
1708 gettext_noop ("# FIND PEER requests ignored due to Bloomfilter"), 1,
1714 GNUNET_STATISTICS_update (GDS_stats,
1715 gettext_noop ("# FIND PEER requests ignored due to lack of HELLO"), 1,
1719 /* then, also consider sending a random HELLO from the closest bucket */
1720 if (0 == memcmp (&my_identity.hashPubKey, key, sizeof (GNUNET_HashCode)))
1721 bucket_idx = closest_bucket;
1723 bucket_idx = GNUNET_MIN (closest_bucket, find_bucket (key));
1724 if (bucket_idx == GNUNET_SYSERR)
1726 bucket = &k_buckets[bucket_idx];
1727 if (bucket->peers_size == 0)
1729 choice = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
1730 bucket->peers_size);
1731 peer = bucket->head;
1734 GNUNET_assert (peer != NULL);
1738 choice = bucket->peers_size;
1743 return; /* no non-masked peer available */
1745 peer = bucket->head;
1746 GNUNET_BLOCK_mingle_hash (&peer->id.hashPubKey, bf_mutator, &mhash);
1747 hello = GDS_HELLO_get (&peer->id);
1749 while ( (hello == NULL) ||
1750 (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (bf, &mhash)) );
1751 GDS_NEIGHBOURS_handle_reply (sender,
1752 GNUNET_BLOCK_TYPE_DHT_HELLO,
1753 GNUNET_TIME_relative_to_absolute (GNUNET_CONSTANTS_HELLO_ADDRESS_EXPIRATION),
1758 GNUNET_HELLO_size (hello));
1763 * Core handler for p2p get requests.
1765 * @param cls closure
1766 * @param peer sender of the request
1767 * @param message message
1768 * @param peer peer identity this notification is about
1769 * @param atsi performance data
1770 * @return GNUNET_OK to keep the connection open,
1771 * GNUNET_SYSERR to close it (signal serious error)
1774 handle_dht_p2p_get (void *cls, const struct GNUNET_PeerIdentity *peer,
1775 const struct GNUNET_MessageHeader *message,
1776 const struct GNUNET_TRANSPORT_ATS_Information
1779 struct PeerGetMessage *get;
1780 uint32_t xquery_size;
1781 size_t reply_bf_size;
1783 enum GNUNET_BLOCK_Type type;
1784 enum GNUNET_DHT_RouteOption options;
1785 enum GNUNET_BLOCK_EvaluationResult eval;
1786 struct GNUNET_CONTAINER_BloomFilter *reply_bf;
1787 struct GNUNET_CONTAINER_BloomFilter *peer_bf;
1790 GNUNET_break (0 != memcmp (peer, &my_identity, sizeof (struct GNUNET_PeerIdentity)));
1791 /* parse and validate message */
1792 msize = ntohs (message->size);
1793 if (msize < sizeof (struct PeerGetMessage))
1795 GNUNET_break_op (0);
1798 get = (struct PeerGetMessage *) message;
1799 xquery_size = ntohl (get->xquery_size);
1800 if (msize < sizeof (struct PeerGetMessage) + xquery_size)
1802 GNUNET_break_op (0);
1805 GNUNET_STATISTICS_update (GDS_stats,
1806 gettext_noop ("# P2P GET requests received"), 1,
1808 reply_bf_size = msize - (sizeof (struct PeerGetMessage) + xquery_size);
1809 type = ntohl (get->type);
1810 options = ntohl (get->options);
1811 xquery = (const char*) &get[1];
1813 if (reply_bf_size > 0)
1814 reply_bf = GNUNET_CONTAINER_bloomfilter_init (&xquery[xquery_size],
1816 GNUNET_CONSTANTS_BLOOMFILTER_K);
1817 eval = GNUNET_BLOCK_evaluate (GDS_block_context,
1822 xquery, xquery_size,
1824 if (eval != GNUNET_BLOCK_EVALUATION_REQUEST_VALID)
1826 /* request invalid or block type not supported */
1827 GNUNET_break_op (eval == GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED);
1828 if (NULL != reply_bf)
1829 GNUNET_CONTAINER_bloomfilter_free (reply_bf);
1833 GNUNET_CONTAINER_bloomfilter_init (get->bloomfilter,
1835 GNUNET_CONSTANTS_BLOOMFILTER_K);
1836 GNUNET_break_op (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (peer_bf, &peer->hashPubKey));
1837 /* remember request for routing replies */
1838 GDS_ROUTING_add (peer,
1842 xquery, xquery_size,
1843 reply_bf, get->bf_mutator);
1844 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1845 "GET for %s at %s after %u hops\n",
1846 GNUNET_h2s (&get->key),
1847 GNUNET_i2s (&my_identity),
1848 (unsigned int) ntohl (get->hop_count));
1849 /* local lookup (this may update the reply_bf) */
1850 if ( (0 != (options & GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE)) ||
1851 (am_closest_peer (&get->key,
1854 if ( (0 != (options & GNUNET_DHT_RO_FIND_PEER)))
1856 GNUNET_STATISTICS_update (GDS_stats,
1857 gettext_noop ("# P2P FIND PEER requests processed"), 1,
1859 handle_find_peer (peer,
1866 eval = GDS_DATACACHE_handle_get (&get->key,
1868 xquery, xquery_size,
1875 GNUNET_STATISTICS_update (GDS_stats,
1876 gettext_noop ("# P2P GET requests ONLY routed"), 1,
1880 /* P2P forwarding */
1881 if (eval != GNUNET_BLOCK_EVALUATION_OK_LAST)
1882 GDS_NEIGHBOURS_handle_get (type,
1884 ntohl (get->desired_replication_level),
1885 ntohl (get->hop_count),
1887 xquery, xquery_size,
1892 if (NULL != reply_bf)
1893 GNUNET_CONTAINER_bloomfilter_free (reply_bf);
1894 GNUNET_CONTAINER_bloomfilter_free (peer_bf);
1900 * Core handler for p2p result messages.
1902 * @param cls closure
1903 * @param message message
1904 * @param peer peer identity this notification is about
1905 * @param atsi performance data
1906 * @return GNUNET_YES (do not cut p2p connection)
1909 handle_dht_p2p_result (void *cls, const struct GNUNET_PeerIdentity *peer,
1910 const struct GNUNET_MessageHeader *message,
1911 const struct GNUNET_TRANSPORT_ATS_Information
1914 const struct PeerResultMessage *prm;
1915 const struct GNUNET_PeerIdentity *put_path;
1916 const struct GNUNET_PeerIdentity *get_path;
1918 uint32_t get_path_length;
1919 uint32_t put_path_length;
1922 enum GNUNET_BLOCK_Type type;
1924 /* parse and validate message */
1925 msize = ntohs (message->size);
1926 if (msize < sizeof (struct PeerResultMessage))
1928 GNUNET_break_op (0);
1931 prm = (struct PeerResultMessage *) message;
1932 put_path_length = ntohl (prm->put_path_length);
1933 get_path_length = ntohl (prm->get_path_length);
1934 if ( (msize < sizeof (struct PeerResultMessage) +
1935 (get_path_length + put_path_length) * sizeof (struct GNUNET_PeerIdentity)) ||
1936 (get_path_length > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) ||
1937 (put_path_length > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)) )
1939 GNUNET_break_op (0);
1942 GNUNET_STATISTICS_update (GDS_stats,
1943 gettext_noop ("# P2P RESULTS received"), 1,
1945 put_path = (const struct GNUNET_PeerIdentity*) &prm[1];
1946 get_path = &put_path[put_path_length];
1947 type = ntohl (prm->type);
1948 data = (const void*) &get_path[get_path_length];
1949 data_size = msize - (sizeof (struct PeerResultMessage) +
1950 (get_path_length + put_path_length) * sizeof (struct GNUNET_PeerIdentity));
1952 /* if we got a HELLO, consider it for our own routing table */
1953 if (type == GNUNET_BLOCK_TYPE_DHT_HELLO)
1955 const struct GNUNET_MessageHeader *h;
1956 struct GNUNET_PeerIdentity pid;
1959 /* Should be a HELLO, validate and consider using it! */
1960 if (data_size < sizeof (struct GNUNET_MessageHeader))
1962 GNUNET_break_op (0);
1966 if (data_size != ntohs (h->size))
1968 GNUNET_break_op (0);
1972 GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message*) h,
1975 GNUNET_break_op (0);
1978 if (0 != memcmp (&my_identity, &pid, sizeof (struct GNUNET_PeerIdentity)))
1980 bucket = find_bucket (&pid.hashPubKey);
1981 if ( (bucket >= 0) &&
1982 (k_buckets[bucket].peers_size < bucket_size) )
1984 if (NULL != GDS_transport_handle)
1986 GNUNET_TRANSPORT_offer_hello (GDS_transport_handle,
1988 GNUNET_TRANSPORT_try_connect (GDS_transport_handle,
1995 /* append 'peer' to 'get_path' */
1997 struct GNUNET_PeerIdentity xget_path[get_path_length+1];
1999 memcpy (xget_path, get_path, get_path_length * sizeof (struct GNUNET_PeerIdentity));
2000 xget_path[get_path_length] = *peer;
2003 /* forward to local clients */
2004 GDS_CLIENTS_handle_reply (GNUNET_TIME_absolute_ntoh (prm->expiration_time),
2014 /* forward to other peers */
2015 GDS_ROUTING_process (type,
2016 GNUNET_TIME_absolute_ntoh (prm->expiration_time),
2030 * Initialize neighbours subsystem.
2032 * @return GNUNET_OK on success, GNUNET_SYSERR on error
2035 GDS_NEIGHBOURS_init ()
2037 static struct GNUNET_CORE_MessageHandler core_handlers[] = {
2038 {&handle_dht_p2p_get, GNUNET_MESSAGE_TYPE_DHT_P2P_GET, 0},
2039 {&handle_dht_p2p_put, GNUNET_MESSAGE_TYPE_DHT_P2P_PUT, 0},
2040 {&handle_dht_p2p_result, GNUNET_MESSAGE_TYPE_DHT_P2P_RESULT, 0},
2043 unsigned long long temp_config_num;
2046 GNUNET_CONFIGURATION_get_value_number (GDS_cfg, "DHT", "bucket_size",
2048 bucket_size = (unsigned int) temp_config_num;
2049 atsAPI = GNUNET_ATS_init (GDS_cfg, NULL, NULL);
2050 coreAPI = GNUNET_CORE_connect (GDS_cfg,
2054 &handle_core_connect,
2055 &handle_core_disconnect,
2059 if (coreAPI == NULL)
2060 return GNUNET_SYSERR;
2061 all_known_peers = GNUNET_CONTAINER_multihashmap_create (256);
2067 * Shutdown neighbours subsystem.
2070 GDS_NEIGHBOURS_done ()
2072 if (coreAPI == NULL)
2074 GNUNET_CORE_disconnect (coreAPI);
2076 GNUNET_ATS_shutdown (atsAPI);
2078 GNUNET_assert (0 == GNUNET_CONTAINER_multihashmap_size (all_known_peers));
2079 GNUNET_CONTAINER_multihashmap_destroy (all_known_peers);
2080 all_known_peers = NULL;
2081 if (GNUNET_SCHEDULER_NO_TASK != find_peer_task)
2083 GNUNET_SCHEDULER_cancel (find_peer_task);
2084 find_peer_task = GNUNET_SCHEDULER_NO_TASK;
2089 /* end of gnunet-service-dht_neighbours.c */