2 This file is part of GNUnet.
3 Copyright (C) 2009-2015 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.
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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.
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,
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21 * @file dht/gnunet-service-wdht_neighbours.c
22 * @brief GNUnet DHT service's finger and friend table management code
23 * @author Supriti Singh
26 #include "gnunet_util_lib.h"
27 #include "gnunet_block_lib.h"
28 #include "gnunet_hello_lib.h"
29 #include "gnunet_constants.h"
30 #include "gnunet_protocols.h"
31 #include "gnunet_ats_service.h"
32 #include "gnunet_core_service.h"
33 #include "gnunet_datacache_lib.h"
34 #include "gnunet_transport_service.h"
35 #include "gnunet_dht_service.h"
36 #include "gnunet_statistics_service.h"
37 #include "gnunet-service-wdht.h"
38 #include "gnunet-service-wdht_clients.h"
39 #include "gnunet-service-wdht_datacache.h"
40 #include "gnunet-service-wdht_neighbours.h"
41 #include "gnunet-service-wdht_nse.h"
48 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, __VA_ARGS__)
51 * Trail timeout. After what time do trails always die?
53 #define TRAIL_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 42)
56 * Random walk delay. How often do we walk the overlay?
58 #define RANDOM_WALK_DELAY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 42)
61 * The number of layered ID to use.
63 #define NUMBER_LAYERED_ID 8
66 * The number of random walk to launch at the beginning of the initialization
68 /* FIXME: find a better value */
69 #define NUMBER_RANDOM_WALK 20
72 /******************* The db structure and related functions *******************/
75 * Entry in #friends_peermap.
81 * Information we keep per trail.
87 * MDLL entry in the list of all trails with the same predecessor.
89 struct Trail *prev_succ;
92 * MDLL entry in the list of all trails with the same predecessor.
94 struct Trail *next_succ;
97 * MDLL entry in the list of all trails with the same predecessor.
99 struct Trail *prev_pred;
102 * MDLL entry in the list of all trails with the same predecessor.
104 struct Trail *next_pred;
107 * Our predecessor in the trail, NULL if we are initiator (?).
109 struct FriendInfo *pred;
112 * Our successor in the trail, NULL if we are the last peer.
114 struct FriendInfo *succ;
117 * Identifier of the trail with the predecessor.
119 struct GNUNET_HashCode pred_id;
122 * Identifier of the trail with the successor.
124 struct GNUNET_HashCode succ_id;
127 * When does this trail expire.
129 struct GNUNET_TIME_Absolute expiration_time;
132 * Location of this trail in the heap.
134 struct GNUNET_CONTAINER_HeapNode *hn;
137 * If this peer started the to create a Finger (and thus @e pred is
138 * NULL), this is the Finger we are trying to intialize.
140 struct Finger **finger;
146 * Entry in #friends_peermap.
153 struct GNUNET_PeerIdentity id;
158 struct Trail *pred_head;
163 struct Trail *pred_tail;
168 struct Trail *succ_head;
173 struct Trail *succ_tail;
176 * Core handle for sending messages to this friend.
178 struct GNUNET_MQ_Handle *mq;
202 struct FingerTable *ft;
207 struct GNUNET_HashCode destination;
210 * #GNUNET_YES if a response has been received. Otherwise #GNUNET_NO.
219 * Array of our fingers, unsorted.
221 struct Finger **fingers;
224 * Array of sorted fingers (sorted by destination, valid fingers first).
226 struct Finger **sorted_fingers;
229 * Size of the finger array.
231 unsigned int finger_array_size;
234 * Number of valid entries in @e sorted_fingers (contiguous from offset 0)
236 unsigned int number_valid_fingers;
239 * Which offset in @e fingers will we redo next.
241 unsigned int walk_offset;
244 * Is the finger array sorted?
251 /*********************** end of the db structure part ***********************/
254 GNUNET_NETWORK_STRUCT_BEGIN
257 * Setup a finger using the underlay topology ("social network").
259 struct RandomWalkMessage
262 * Type: #GNUNET_MESSAGE_TYPE_WDHT_RANDOM_WALK
264 struct GNUNET_MessageHeader header;
267 * Number of hops this message has taken so far, we stop at
270 uint16_t hops_taken GNUNET_PACKED;
273 * Layer for the request, in NBO.
275 uint16_t layer GNUNET_PACKED;
278 * Unique (random) identifier this peer will use to
279 * identify the trail (in future messages).
281 struct GNUNET_HashCode trail_id;
286 * Response to a `struct RandomWalkMessage`.
288 struct RandomWalkResponseMessage
291 * Type: #GNUNET_MESSAGE_TYPE_WDHT_RANDOM_WALK_RESPONSE
293 struct GNUNET_MessageHeader header;
296 * Zero, for alignment.
298 uint32_t reserved GNUNET_PACKED;
301 * Unique (random) identifier from the
302 * `struct RandomWalkMessage`.
304 struct GNUNET_HashCode trail_id;
307 * Random location in the respective layer where the
308 * random path of the finger setup terminated.
310 struct GNUNET_HashCode location;
315 * Response to an event that causes a trail to die.
317 struct TrailDestroyMessage
320 * Type: #GNUNET_MESSAGE_TYPE_WDHT_TRAIL_DESTROY
322 struct GNUNET_MessageHeader header;
325 * Zero, for alignment.
327 uint32_t reserved GNUNET_PACKED;
330 * Unique (random) identifier this peer will use to
331 * identify the finger (in future messages).
333 struct GNUNET_HashCode trail_id;
339 * Send a message along a trail.
341 struct FindSuccessorMessage
344 * Type: #GNUNET_MESSAGE_TYPE_WDHT_FIND_SUCCESSOR
346 struct GNUNET_MessageHeader header;
349 * Zero, for alignment.
351 uint32_t reserved GNUNET_PACKED;
354 * Unique (random) identifier this peer will use to
355 * identify the finger (in future messages).
357 struct GNUNET_HashCode trail_id;
360 * Key for which we would like close values returned.
361 * identify the finger (in future messages).
363 struct GNUNET_HashCode key;
369 * Send a message along a trail.
371 struct TrailRouteMessage
374 * Type: #GNUNET_MESSAGE_TYPE_WDHT_TRAIL_ROUTE
376 struct GNUNET_MessageHeader header;
379 * #GNUNET_YES if the path should be recorded, #GNUNET_NO if not; in NBO.
381 uint16_t record_path GNUNET_PACKED;
384 * Length of the recorded trail, 0 if @e record_path is #GNUNET_NO; in NBO.
386 uint16_t path_length GNUNET_PACKED;
389 * Unique (random) identifier this peer will use to
390 * identify the finger (in future messages).
392 struct GNUNET_HashCode trail_id;
395 * Path the message has taken so far (excluding sender).
397 /* struct GNUNET_PeerIdentity path[path_length]; */
399 /* followed by payload (another `struct GNUNET_MessageHeader`) to
400 send along the trail */
407 struct PeerPutMessage
410 * Type: #GNUNET_MESSAGE_TYPE_WDHT_PUT
412 struct GNUNET_MessageHeader header;
417 uint32_t options GNUNET_PACKED;
422 uint32_t block_type GNUNET_PACKED;
427 uint32_t hop_count GNUNET_PACKED;
430 * Replication level for this message
431 * In the current implementation, this value is not used.
433 uint32_t desired_replication_level GNUNET_PACKED;
436 * Length of the PUT path that follows (if tracked).
438 uint32_t put_path_length GNUNET_PACKED;
441 * When does the content expire?
443 struct GNUNET_TIME_AbsoluteNBO expiration_time;
446 * The key to store the value under.
448 struct GNUNET_HashCode key GNUNET_PACKED;
450 /* put path (if tracked) */
459 struct PeerGetMessage
462 * Type: #GNUNET_MESSAGE_TYPE_WDHT_GET
464 struct GNUNET_MessageHeader header;
469 uint32_t options GNUNET_PACKED;
472 * Desired content type.
474 uint32_t block_type GNUNET_PACKED;
479 uint32_t hop_count GNUNET_PACKED;
482 * Desired replication level for this request.
483 * In the current implementation, this value is not used.
485 uint32_t desired_replication_level GNUNET_PACKED;
488 * Total number of peers in get path.
490 unsigned int get_path_length;
493 * The key we are looking for.
495 struct GNUNET_HashCode key;
498 /* struct GNUNET_PeerIdentity[]*/
505 struct PeerGetResultMessage
508 * Type: #GNUNET_MESSAGE_TYPE_WDHT_GET_RESULT
510 struct GNUNET_MessageHeader header;
513 * The type for the data.
515 uint32_t type GNUNET_PACKED;
518 * Number of peers recorded in the outgoing path from source to the
519 * stored location of this message.
521 uint32_t put_path_length GNUNET_PACKED;
524 * Length of the GET path that follows (if tracked).
526 uint32_t get_path_length GNUNET_PACKED;
529 * Peer which queried for get and should get the result.
531 struct GNUNET_PeerIdentity querying_peer;
534 * When does the content expire?
536 struct GNUNET_TIME_Absolute expiration_time;
539 * The key of the corresponding GET request.
541 struct GNUNET_HashCode key;
543 /* put path (if tracked) */
545 /* get path (if tracked) */
551 GNUNET_NETWORK_STRUCT_END
555 * Contains all the layered IDs of this peer.
557 struct GNUNET_PeerIdentity layered_id[NUMBER_LAYERED_ID];
560 * Task to timeout trails that have expired.
562 static struct GNUNET_SCHEDULER_Task *trail_timeout_task;
565 * Task to perform random walks.
567 static struct GNUNET_SCHEDULER_Task *random_walk_task;
570 * Identity of this peer.
572 static struct GNUNET_PeerIdentity my_identity;
575 * Peer map of all the friends of a peer
577 static struct GNUNET_CONTAINER_MultiPeerMap *friends_peermap;
582 static struct FingerTable fingers[NUMBER_LAYERED_ID];
585 * Tail map, mapping tail identifiers to `struct Trail`s
587 static struct GNUNET_CONTAINER_MultiHashMap *trail_map;
590 * Tail heap, organizing trails by expiration time.
592 static struct GNUNET_CONTAINER_Heap *trail_heap;
597 static struct GNUNET_CORE_Handle *core_api;
601 * Handle the put request from the client.
603 * @param key Key for the content
604 * @param block_type Type of the block
605 * @param options Routing options
606 * @param desired_replication_level Desired replication count
607 * @param expiration_time When does the content expire
608 * @param data Content to store
609 * @param data_size Size of content @a data in bytes
612 GDS_NEIGHBOURS_handle_put (const struct GNUNET_HashCode *key,
613 enum GNUNET_BLOCK_Type block_type,
614 enum GNUNET_DHT_RouteOption options,
615 uint32_t desired_replication_level,
616 struct GNUNET_TIME_Absolute expiration_time,
620 GDS_DATACACHE_handle_put (expiration_time,
627 GDS_CLIENTS_process_put (options,
639 * Handle the get request from the client file. If I am destination do
640 * datacache put and return. Else find the target friend and forward message
643 * @param key Key for the content
644 * @param block_type Type of the block
645 * @param options Routing options
646 * @param desired_replication_level Desired replication count
649 GDS_NEIGHBOURS_handle_get (const struct GNUNET_HashCode *key,
650 enum GNUNET_BLOCK_Type block_type,
651 enum GNUNET_DHT_RouteOption options,
652 uint32_t desired_replication_level)
654 // find closest finger(s) on all layers
655 // use TrailRoute with PeerGetMessage embedded to contact peer
660 * Delete a trail, it died (timeout, link failure, etc.).
662 * @param trail trail to delete from all data structures
663 * @param inform_pred should we notify the predecessor?
664 * @param inform_succ should we inform the successor?
667 delete_trail (struct Trail *trail,
671 struct FriendInfo *friend;
672 struct GNUNET_MQ_Envelope *env;
673 struct TrailDestroyMessage *tdm;
674 struct Finger *finger;
676 friend = trail->pred;
679 if (GNUNET_YES == inform_pred)
681 env = GNUNET_MQ_msg (tdm,
682 GNUNET_MESSAGE_TYPE_WDHT_TRAIL_DESTROY);
683 tdm->trail_id = trail->pred_id;
684 GNUNET_MQ_send (friend->mq,
687 GNUNET_CONTAINER_MDLL_remove (pred,
692 friend = trail->succ;
695 if (GNUNET_YES == inform_succ)
697 env = GNUNET_MQ_msg (tdm,
698 GNUNET_MESSAGE_TYPE_WDHT_TRAIL_DESTROY);
699 tdm->trail_id = trail->pred_id;
700 GNUNET_MQ_send (friend->mq,
703 GNUNET_CONTAINER_MDLL_remove (succ,
708 GNUNET_break (trail ==
709 GNUNET_CONTAINER_heap_remove_node (trail->hn));
710 finger = *trail->finger;
713 *trail->finger = NULL;
714 GNUNET_free (finger);
721 * Send the get result to requesting client.
723 * @param trail_id trail identifying where to send the result to, NULL for us
724 * @param key Key of the requested data.
725 * @param type Block type
726 * @param put_path_length Number of peers in @a put_path
727 * @param put_path Path taken to put the data at its stored location.
728 * @param expiration When will this result expire?
729 * @param data Payload to store
730 * @param data_size Size of the @a data
733 GDS_NEIGHBOURS_send_get_result (const struct GNUNET_HashCode *trail_id,
734 const struct GNUNET_HashCode *key,
735 enum GNUNET_BLOCK_Type type,
736 unsigned int put_path_length,
737 const struct GNUNET_PeerIdentity *put_path,
738 struct GNUNET_TIME_Absolute expiration,
742 // TRICKY: need to introduce some context to remember trail from
748 * Method called whenever a peer disconnects.
751 * @param peer peer identity this notification is about
754 handle_core_disconnect (void *cls,
755 const struct GNUNET_PeerIdentity *peer)
757 struct FriendInfo *remove_friend;
760 /* If disconnected to own identity, then return. */
761 if (0 == memcmp (&my_identity,
763 sizeof (struct GNUNET_PeerIdentity)))
766 if (NULL == (remove_friend =
767 GNUNET_CONTAINER_multipeermap_get (friends_peermap,
774 GNUNET_assert (GNUNET_YES ==
775 GNUNET_CONTAINER_multipeermap_remove (friends_peermap,
778 while (NULL != (t = remove_friend->succ_head))
782 while (NULL != (t = remove_friend->pred_head))
786 GNUNET_MQ_destroy (remove_friend->mq);
787 GNUNET_free (remove_friend);
789 GNUNET_CONTAINER_multipeermap_size (friends_peermap))
791 GNUNET_SCHEDULER_cancel (random_walk_task);
792 random_walk_task = NULL;
798 * Pick random friend from friends for random walk.
800 static struct FriendInfo *
801 pick_random_friend ()
803 // TODO: need to extend peermap API to return random entry...
804 // (Note: same extension exists for hashmap API).
805 return NULL; // FIXME...
810 * Initiate a random walk.
816 do_random_walk (void *cls,
817 const struct GNUNET_SCHEDULER_TaskContext *tc)
819 static unsigned int walk_layer;
820 struct FriendInfo *friend;
821 struct GNUNET_MQ_Envelope *env;
822 struct RandomWalkMessage *rwm;
823 struct FingerTable *ft;
824 struct Finger *finger;
827 random_walk_task = NULL;
828 friend = pick_random_friend ();
830 trail = GNUNET_new (struct Trail);
831 /* We create the random walk so, no predecessor */
832 trail->succ = friend;
833 GNUNET_CRYPTO_hash_create_random (GNUNET_CRYPTO_QUALITY_NONCE,
836 GNUNET_CONTAINER_multihashmap_put (trail_map,
839 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
845 GNUNET_CONTAINER_MDLL_insert (succ,
849 env = GNUNET_MQ_msg (rwm,
850 GNUNET_MESSAGE_TYPE_WDHT_RANDOM_WALK);
851 rwm->hops_taken = htonl (0);
852 rwm->trail_id = trail->succ_id;
853 GNUNET_MQ_send (friend->mq,
855 /* clean up 'old' entry (implicitly via trail cleanup) */
856 ft = &fingers[walk_layer];
858 if ( (NULL != ft->fingers) &&
859 (NULL != (finger = ft->fingers[ft->walk_offset])) )
860 delete_trail (finger->trail,
863 if (ft->finger_array_size < 42)
865 // FIXME: must have finger array of the right size here,
866 // FIXME: growing / shrinking are tricy -- with pointers
870 GNUNET_assert (NULL == ft->fingers[ft->walk_offset]);
872 finger = GNUNET_new (struct Finger);
873 finger->trail = trail;
874 trail->finger = &ft->fingers[ft->walk_offset];
876 ft->fingers[ft->walk_offset] = finger;
877 ft->is_sorted = GNUNET_NO;
878 ft->walk_offset = (ft->walk_offset + 1) % ft->finger_array_size;
880 walk_layer = (walk_layer + 1) % NUMBER_LAYERED_ID;
881 random_walk_task = GNUNET_SCHEDULER_add_delayed (RANDOM_WALK_DELAY,
888 * Method called whenever a peer connects.
891 * @param peer_identity peer identity this notification is about
894 handle_core_connect (void *cls,
895 const struct GNUNET_PeerIdentity *peer_identity)
897 struct FriendInfo *friend;
899 /* Check for connect to self message */
900 if (0 == memcmp (&my_identity,
902 sizeof (struct GNUNET_PeerIdentity)))
905 /* If peer already exists in our friend_peermap, then exit. */
907 GNUNET_CONTAINER_multipeermap_contains (friends_peermap,
914 friend = GNUNET_new (struct FriendInfo);
915 friend->id = *peer_identity;
916 friend->mq = GNUNET_CORE_mq_create (core_api,
918 GNUNET_assert (GNUNET_OK ==
919 GNUNET_CONTAINER_multipeermap_put (friends_peermap,
922 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
923 if (NULL == random_walk_task)
925 /* random walk needs to be started -- we have a first connection */
926 random_walk_task = GNUNET_SCHEDULER_add_now (&do_random_walk,
933 * To be called on core init/fail.
935 * @param cls service closure
936 * @param identity the public identity of this peer
939 core_init (void *cls,
940 const struct GNUNET_PeerIdentity *identity)
942 my_identity = *identity;
947 * Handle a `struct RandomWalkMessage` from a
948 * #GNUNET_MESSAGE_TYPE_WDHT_RANDOM_WALK message.
950 * @param cls closure (NULL)
951 * @param peer sender identity
952 * @param message the setup message
953 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
956 handle_dht_p2p_random_walk (void *cls,
957 const struct GNUNET_PeerIdentity *peer,
958 const struct GNUNET_MessageHeader *message)
960 const struct RandomWalkMessage *m;
962 struct FriendInfo *pred;
964 m = (const struct RandomWalkMessage *) message;
965 pred = GNUNET_CONTAINER_multipeermap_get (friends_peermap,
967 t = GNUNET_new (struct Trail);
968 t->pred_id = m->trail_id;
970 t->expiration_time = GNUNET_TIME_relative_to_absolute (TRAIL_TIMEOUT);
972 GNUNET_CONTAINER_multihashmap_put (trail_map,
975 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
979 return GNUNET_SYSERR;
981 GNUNET_CONTAINER_MDLL_insert (pred,
985 if (ntohl (m->hops_taken) > GDS_NSE_get ())
987 /* We are the last hop, generate response */
988 struct GNUNET_MQ_Envelope *env;
989 struct RandomWalkResponseMessage *rwrm;
992 env = GNUNET_MQ_msg (rwrm,
993 GNUNET_MESSAGE_TYPE_WDHT_RANDOM_WALK_RESPONSE);
994 rwrm->reserved = htonl (0);
995 rwrm->trail_id = m->trail_id;
996 layer = ntohs (m->layer);
998 (void) GDS_DATACACHE_get_random_key (&rwrm->location);
1001 struct FingerTable *ft;
1003 if (layer > NUMBER_LAYERED_ID)
1005 GNUNET_break_op (0);
1006 // FIXME: clean up 't'...
1007 return GNUNET_SYSERR;
1009 ft = &fingers[layer-1];
1010 if (0 == ft->number_valid_fingers)
1012 GNUNET_CRYPTO_hash_create_random (GNUNET_CRYPTO_QUALITY_NONCE,
1019 f = ft->fingers[GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
1020 ft->number_valid_fingers)];
1021 rwrm->location = f->destination;
1024 GNUNET_MQ_send (pred->mq,
1029 struct GNUNET_MQ_Envelope *env;
1030 struct RandomWalkMessage *rwm;
1031 struct FriendInfo *succ;
1033 /* extend the trail by another random hop */
1034 succ = pick_random_friend ();
1035 GNUNET_CRYPTO_hash_create_random (GNUNET_CRYPTO_QUALITY_NONCE,
1039 GNUNET_CONTAINER_multihashmap_put (trail_map,
1042 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
1045 GNUNET_CONTAINER_MDLL_remove (pred,
1052 GNUNET_CONTAINER_MDLL_insert (succ,
1056 env = GNUNET_MQ_msg (rwm,
1057 GNUNET_MESSAGE_TYPE_WDHT_RANDOM_WALK);
1058 rwm->hops_taken = htons (1 + ntohs (m->hops_taken));
1059 rwm->layer = m->layer;
1060 rwm->trail_id = t->succ_id;
1061 GNUNET_MQ_send (succ->mq,
1069 * Handle a `struct RandomWalkResponseMessage` from a GNUNET_MESSAGE_TYPE_WDHT_RANDOM_WALK_RESPONSE
1072 * @param cls closure (NULL)
1073 * @param peer sender identity
1074 * @param message the setup response message
1075 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
1078 handle_dht_p2p_random_walk_response (void *cls,
1079 const struct GNUNET_PeerIdentity *peer,
1080 const struct GNUNET_MessageHeader *message)
1082 const struct RandomWalkResponseMessage *rwrm;
1084 rwrm = (const struct RandomWalkResponseMessage *) message;
1085 // 1) lookup trail => find Finger entry => fill in 'destination' and mark valid, move to end of sorted array, mark unsorted, update links from 'trails'
1088 * 1 check if we are the correct layer
1089 * 1.a if true : add the returned value (finger) in the db structure
1090 * 1.b if true : do nothing
1092 /* FIXME: add the value in db structure 1.a */
1099 * Handle a `struct TrailDestroyMessage`.
1101 * @param cls closure (NULL)
1102 * @param peer sender identity
1103 * @param message the finger destroy message
1104 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
1107 handle_dht_p2p_trail_destroy (void *cls,
1108 const struct GNUNET_PeerIdentity *peer,
1109 const struct GNUNET_MessageHeader *message)
1111 const struct TrailDestroyMessage *tdm;
1113 tdm = (const struct TrailDestroyMessage *) message;
1117 * 1 check if message comme from a trail (that we still remember...)
1118 * 1.a.1 if true: send the destroy message to the rest trail
1119 * 1.a.2 clean the trail structure
1120 * 1.a.3 did i have to remove the trail and ID from the db structure?
1121 * 1.b if false: do nothing
1129 * Handler for a message we received along some trail.
1131 * @param cls closure
1132 * @param trail_id trail identifier
1133 * @param message the message we got
1134 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
1137 (*TrailHandlerCallback)(void *cls,
1138 const struct GNUNET_HashCode *trail_id,
1139 const struct GNUNET_MessageHandler *message);
1143 * Definition of a handler for a message received along some trail.
1148 * NULL for end-of-list.
1150 TrailHandlerCallback callback;
1153 * Closure for @e callback.
1158 * Message type this handler addresses.
1160 uint16_t message_type;
1163 * Use 0 for variable-size.
1165 uint16_t message_size;
1170 * Handle a `struct TrailRouteMessage`.
1172 * @param cls closure (NULL)
1173 * @param peer sender identity
1174 * @param message the finger destroy message
1175 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
1178 handle_dht_p2p_trail_route (void *cls,
1179 const struct GNUNET_PeerIdentity *peer,
1180 const struct GNUNET_MessageHeader *message)
1182 const struct TrailRouteMessage *trm;
1184 trm = (const struct TrailRouteMessage *) message;
1188 * 1 check if message comme from a trail
1189 * 1.a.1 if trail not finished with us, continue to forward
1190 * 1.a.2 otherwise handle body message embedded in trail
1197 * Handle a `struct FindSuccessorMessage` from a #GNUNET_MESSAGE_TYPE_WDHT_SUCCESSOR_FIND
1200 * @param cls closure (NULL)
1201 * @param trail_id path to the originator
1202 * @param message the finger setup message
1203 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
1206 handle_dht_p2p_successor_find (void *cls,
1207 const struct GNUNET_HashCode *trail_id,
1208 const struct GNUNET_MessageHeader *message)
1210 const struct FindSuccessorMessage *fsm;
1212 fsm = (const struct FindSuccessorMessage *) message;
1213 // locate trail (for sending reply), if not exists, fail nicely.
1214 // otherwise, go to datacache and return 'top k' elements closest to 'key'
1215 // as "PUT" messages via the trail (need to extend DB API!)
1217 GDS_DATACACHE_get_successors (trail_id,
1225 * Handle a `struct PeerGetMessage`.
1227 * @param cls closure (NULL)
1228 * @param trail_id path to the originator
1229 * @param message the peer get message
1230 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
1233 handle_dht_p2p_peer_get (void *cls,
1234 const struct GNUNET_HashCode *trail_id,
1235 const struct GNUNET_MessageHeader *message)
1237 const struct PeerGetMessage *pgm;
1239 // FIXME: note: never called like this, message embedded with trail route!
1240 pgm = (const struct PeerGetMessage *) message;
1241 // -> lookup in datacache (figure out way to remember trail!)
1244 * 1 extract the result
1246 * 3 send it using the good trail
1248 * What do i do when i don't have the key/value?
1256 * Handle a `struct PeerGetResultMessage`.
1258 * @param cls closure (NULL)
1259 * @param trail_id path to the originator
1260 * @param message the peer get result message
1261 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
1264 handle_dht_p2p_peer_get_result (void *cls,
1265 const struct GNUNET_HashCode *trail_id,
1266 const struct GNUNET_MessageHeader *message)
1268 const struct PeerGetResultMessage *pgrm;
1270 pgrm = (const struct PeerGetResultMessage *) message;
1271 // pretty much: parse, & pass to client (there is some call for that...)
1274 GDS_CLIENTS_process_get (options,
1279 (void) GDS_DATACACHE_handle_get (trail_id,
1292 * Handle a `struct PeerPutMessage`.
1294 * @param cls closure (NULL)
1295 * @param trail_id path to the originator
1296 * @param message the peer put message
1297 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
1300 handle_dht_p2p_peer_put (void *cls,
1301 const struct GNUNET_HashCode *trail_id,
1302 const struct GNUNET_MessageHeader *message)
1304 const struct PeerGetResultMessage *pgrm;
1306 pgrm = (const struct PeerGetResultMessage *) message;
1307 // parse & store in datacache, this is in response to us asking for successors.
1310 * 1 check the size of the message
1311 * 2 use the API to add the value in the "database". Check on the xdht file, how to do it.
1312 * 3 Did i a have to return a notification or did i have to return GNUNET_[OK|SYSERR]?
1315 GDS_DATACACHE_handle_put (expiration_time,
1321 GDS_CLIENTS_process_put (options,
1335 * Initialize neighbours subsystem.
1336 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
1339 GDS_NEIGHBOURS_init (void)
1341 static const struct GNUNET_CORE_MessageHandler core_handlers[] = {
1342 { &handle_dht_p2p_random_walk,
1343 GNUNET_MESSAGE_TYPE_WDHT_RANDOM_WALK,
1344 sizeof (struct RandomWalkMessage) },
1345 { &handle_dht_p2p_random_walk_response,
1346 GNUNET_MESSAGE_TYPE_WDHT_RANDOM_WALK_RESPONSE,
1347 sizeof (struct RandomWalkResponseMessage) },
1348 { &handle_dht_p2p_trail_destroy,
1349 GNUNET_MESSAGE_TYPE_WDHT_TRAIL_DESTROY,
1350 sizeof (struct TrailDestroyMessage) },
1351 { &handle_dht_p2p_trail_route,
1352 GNUNET_MESSAGE_TYPE_WDHT_TRAIL_ROUTE,
1358 GNUNET_CORE_connect (GDS_cfg, NULL,
1360 &handle_core_connect,
1361 &handle_core_disconnect,
1366 if (NULL == core_api)
1367 return GNUNET_SYSERR;
1368 friends_peermap = GNUNET_CONTAINER_multipeermap_create (256, GNUNET_NO);
1369 trail_map = GNUNET_CONTAINER_multihashmap_create (1024, GNUNET_YES);
1370 trail_heap = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
1376 * Shutdown neighbours subsystem.
1379 GDS_NEIGHBOURS_done (void)
1381 if (NULL == core_api)
1383 GNUNET_CORE_disconnect (core_api);
1385 GNUNET_assert (0 == GNUNET_CONTAINER_multipeermap_size (friends_peermap));
1386 GNUNET_CONTAINER_multipeermap_destroy (friends_peermap);
1387 friends_peermap = NULL;
1388 GNUNET_assert (0 == GNUNET_CONTAINER_multihashmap_size (trail_map));
1389 GNUNET_CONTAINER_multihashmap_destroy (trail_map);
1391 GNUNET_CONTAINER_heap_destroy (trail_heap);
1399 * @return my identity
1401 struct GNUNET_PeerIdentity
1402 GDS_NEIGHBOURS_get_my_id (void)
1407 /* end of gnunet-service-wdht_neighbours.c */