2 This file is part of GNUnet.
3 (C) 2009-2014 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-xdht_neighbours.c
23 * @brief GNUnet DHT service's finger and friend table management code
24 * @author Supriti Singh
28 #include "gnunet_util_lib.h"
29 #include "gnunet_block_lib.h"
30 #include "gnunet_hello_lib.h"
31 #include "gnunet_constants.h"
32 #include "gnunet_protocols.h"
33 #include "gnunet_ats_service.h"
34 #include "gnunet_core_service.h"
35 #include "gnunet_datacache_lib.h"
36 #include "gnunet_transport_service.h"
37 #include "gnunet_dht_service.h"
38 #include "gnunet_statistics_service.h"
39 #include "gnunet-service-xdht.h"
40 #include "gnunet-service-xdht_clients.h"
41 #include "gnunet-service-xdht_datacache.h"
42 #include "gnunet-service-xdht_neighbours.h"
43 #include "gnunet-service-xdht_routing.h"
49 * 1. In X-Vine paper, there is no policy defined for replicating the data to
50 * recover in case of peer failure. We can do it in Chord way. In R5N, the key
51 * is hashed and then data is stored according to the key value generated after
53 * 2. We will keep an entry in routing table even if its a friend for the moment.
54 * Because I am not sure if there is a case where it will not work.
55 * Trail id we can keep but actually there is no trail.
61 * 1. check for memory leaks in all the functions, in all the functions
62 * you should check that if you malloc a variable you should free it also.
63 * 2. make sure you have gnunet_assert for all target friends
64 * 3. pay attention to GNUNET_ntohll and endianess
65 * 4. In trail setup, check that you are adding entry even if its a friend.
66 * same for trail setup and add_trail.
67 * 5. go through whole code
68 * 6. make sure make check passes for minimal things i.e. without congestion,
69 * trail threshold, without multiple trails.
70 * 7. write test cases for checking trail congestion, trail threshold, multiple
73 * 8. while going through the code write the comments for malicious peer.
74 * basic - drop packet, ignore message. Not going to check for behaviour
75 * where a peer changes the value as we handle that case everywhere. s
78 1. friend trails count in case it is finger, routing table trail
79 2. select_closest_peer in compare and update predecessor and successor,
85 * Maximum possible fingers (including predecessor) of a peer
87 #define MAX_FINGERS 65
90 * Maximum allowed number of pending messages per friend peer.
92 #define MAXIMUM_PENDING_PER_FRIEND 64
95 * How long to wait before sending another find finger trail request
97 #define DHT_FIND_FINGER_TRAIL_INTERVAL GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30)
100 * How long at most to wait for transmission of a request to a friend ?
102 #define GET_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 2)
105 * Duration for which I may remain congested.
106 * Note: Its a static value. In future, a peer may do some analysis and calculate
107 * congestion_timeout based on 'some' parameters.
109 #define CONGESTION_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 2)
112 * Maximum number of trails allowed to go through a friend.
114 #define TRAILS_THROUGH_FRIEND_THRESHOLD 64
117 * Maximum number of trails stored per finger.
119 #define MAXIMUM_TRAILS_PER_FINGER 1
122 * Finger map index for predecessor entry in finger table.
124 #define PREDECESSOR_FINGER_ID 64
127 * Wrap around in peer identity circle.
129 #define PEER_IDENTITES_WRAP_AROUND pow(2, 64) - 1
132 * FIXME: Its use only at 3 places check if you can remove it.
133 * To check if a finger is predecessor or not.
135 enum GDS_NEIGHBOURS_finger_type
137 GDS_FINGER_TYPE_PREDECESSOR = 0,
138 GDS_FINGER_TYPE_NON_PREDECESSOR = 1
141 GNUNET_NETWORK_STRUCT_BEGIN
146 struct PeerPutMessage
149 * Type: #GNUNET_MESSAGE_TYPE_XDHT_P2P_PUT
151 struct GNUNET_MessageHeader header;
156 uint32_t options GNUNET_PACKED;
161 uint32_t block_type GNUNET_PACKED;
166 uint32_t hop_count GNUNET_PACKED;
169 * Replication level for this message
170 * In the current implementation, this value is not used.
172 uint32_t desired_replication_level GNUNET_PACKED;
175 * Length of the PUT path that follows (if tracked).
177 uint32_t put_path_length GNUNET_PACKED;
180 * Best known destination (could be my friend or finger) which should
181 * get this message next.
183 struct GNUNET_PeerIdentity best_known_destination;
186 * In case best_known_destination is a finger, then trail to reach
187 * to that finger. Else its default value is 0.
189 struct GNUNET_HashCode intermediate_trail_id;
192 * When does the content expire?
194 struct GNUNET_TIME_AbsoluteNBO expiration_time;
197 * The key to store the value under.
199 struct GNUNET_HashCode key GNUNET_PACKED;
201 /* put path (if tracked) */
210 struct PeerGetMessage
213 * Type: #GNUNET_MESSAGE_TYPE_XDHT_P2P_GET
215 struct GNUNET_MessageHeader header;
220 uint32_t options GNUNET_PACKED;
223 * Desired content type.
225 uint32_t block_type GNUNET_PACKED;
230 uint32_t hop_count GNUNET_PACKED;
233 * Desired replication level for this request.
234 * In the current implementation, this value is not used.
236 uint32_t desired_replication_level GNUNET_PACKED;
239 * Total number of peers in get path.
241 unsigned int get_path_length;
244 * Best known destination (could be my friend or finger) which should
245 * get this message next.
247 struct GNUNET_PeerIdentity best_known_destination;
250 * In case best_known_destination is a finger, then trail to reach
251 * to that finger. Else its default value is 0.
253 struct GNUNET_HashCode intermediate_trail_id;
256 * The key we are looking for.
258 struct GNUNET_HashCode key;
261 /* struct GNUNET_PeerIdentity[]*/
267 struct PeerGetResultMessage
270 * Type: #GNUNET_MESSAGE_TYPE_XDHT_P2P_GET_RESULT
272 struct GNUNET_MessageHeader header;
275 * The type for the data.
277 uint32_t type GNUNET_PACKED;
280 * Number of peers recorded in the outgoing path from source to the
281 * stored location of this message.
283 uint32_t put_path_length GNUNET_PACKED;
286 * Length of the GET path that follows (if tracked).
288 uint32_t get_path_length GNUNET_PACKED;
291 * Peer which queried for get and should get the result.
293 struct GNUNET_PeerIdentity querying_peer;
296 * When does the content expire?
298 struct GNUNET_TIME_Absolute expiration_time;
301 * The key of the corresponding GET request.
303 struct GNUNET_HashCode key;
305 /* put path (if tracked) */
307 /* get path (if tracked) */
314 * P2P Trail setup message
316 struct PeerTrailSetupMessage
319 * Type: #GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP
321 struct GNUNET_MessageHeader header;
324 * Is source_peer trying to setup the trail to a predecessor or any finger.
326 uint32_t is_predecessor;
329 * Peer closest to this value will be our finger.
331 uint64_t final_destination_finger_value;
334 * Source peer which wants to setup the trail to one of its finger.
336 struct GNUNET_PeerIdentity source_peer;
339 * Best known destination (could be my friend or finger) which should
340 * get this message next.
342 struct GNUNET_PeerIdentity best_known_destination;
345 * In case best_known_destination is a finger, then trail id of trail to
346 * reach to this finger.
348 struct GNUNET_HashCode intermediate_trail_id;
351 * Trail id for trail which we are trying to setup.
353 struct GNUNET_HashCode trail_id;
355 /* List of peers which are part of trail setup so far.
356 * Trail does NOT include source_peer and peer which will be closest to
357 * ultimate_destination_finger_value.
358 * struct GNUNET_PeerIdentity trail[]
363 * P2P Trail Setup Result message
365 struct PeerTrailSetupResultMessage
369 * Type: #GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP_RESULT
371 struct GNUNET_MessageHeader header;
374 * Finger to which we have found the path.
376 struct GNUNET_PeerIdentity finger_identity;
379 * Peer which started trail_setup to find trail to finger_identity
381 struct GNUNET_PeerIdentity querying_peer;
384 * Is the trail setup to querying_peer's predecessor or finger?
386 uint32_t is_predecessor;
389 * Value to which finger_identity is the closest peer.
391 uint64_t ulitmate_destination_finger_value;
394 * Identifier of the trail from querying peer to finger_identity, NOT
395 * including both endpoints.
397 struct GNUNET_HashCode trail_id;
399 /* List of peers which are part of the trail from querying peer to
400 * finger_identity, NOT including both endpoints.
401 * struct GNUNET_PeerIdentity trail[]
406 * P2P Verify Successor Message.
408 struct PeerVerifySuccessorMessage
411 * Type: #GNUNET_MESSAGE_TYPE_XDHT_P2P_VERIFY_SUCCESSOR
413 struct GNUNET_MessageHeader header;
416 * Peer which wants to verify its successor.
418 struct GNUNET_PeerIdentity source_peer;
421 * Source Peer's current successor.
423 struct GNUNET_PeerIdentity successor;
426 * Identifier of trail to reach from source_peer to successor.
428 struct GNUNET_HashCode trail_id;
430 /* List of the peers which are part of trail to reach from source_peer
431 * to successor, NOT including them
432 * struct GNUNET_PeerIdentity trail[]
437 * P2P Verify Successor Result Message
439 struct PeerVerifySuccessorResultMessage
442 * Type: #GNUNET_MESSAGE_TYPE_XDHT_P2P_VERIFY_SUCCESSOR_RESULT
444 struct GNUNET_MessageHeader header;
447 * Peer which sent the request to verify its successor.
449 struct GNUNET_PeerIdentity querying_peer;
452 * Successor to which PeerVerifySuccessorMessage was sent.
454 struct GNUNET_PeerIdentity current_successor;
457 * Current Predecessor of source_successor. It can be same as querying peer
458 * or different. In case it is different then it can be querying_peer's
459 * probable successor.
461 struct GNUNET_PeerIdentity probable_successor;
464 * Trail identifier of trail from querying_peer to current_successor.
466 struct GNUNET_HashCode trail_id;
469 * Direction in which we are looking at the trail.
471 uint32_t trail_direction;
473 /* In case probable_successor != querying_peer, then trail to reach from
474 * querying_peer to probable_successor, NOT including end points.
475 * struct GNUNET_PeerIdentity trail[]
480 * P2P Notify New Successor Message.
482 struct PeerNotifyNewSuccessorMessage
485 * Type: #GNUNET_MESSAGE_TYPE_XDHT_P2P_NOTIFY_NEW_SUCCESSOR
487 struct GNUNET_MessageHeader header;
490 * Peer which wants to notify its new successor.
492 struct GNUNET_PeerIdentity source_peer;
495 * New successor of source_peer.
497 struct GNUNET_PeerIdentity new_successor;
500 * Unique identifier of the trail from source_peer to new_successor,
501 * NOT including the endpoints.
503 struct GNUNET_HashCode trail_id;
505 /* List of peers in trail from source_peer to new_successor,
506 * NOT including the endpoints.
507 * struct GNUNET_PeerIdentity trail[]
512 * P2P Trail Compression Message.
514 struct PeerTrailCompressionMessage
517 * Type: #GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_COMPRESSION
519 struct GNUNET_MessageHeader header;
522 * Source peer of this trail.
524 struct GNUNET_PeerIdentity source_peer;
527 * Trail from source_peer to destination_peer compressed such that
528 * new_first_friend is the first hop in the trail from source to
531 struct GNUNET_PeerIdentity new_first_friend;
534 * Unique identifier of trail.
536 struct GNUNET_HashCode trail_id;
541 * P2P Trail Tear Down message.
543 struct PeerTrailTearDownMessage
546 * Type: #GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_TEARDOWN
548 struct GNUNET_MessageHeader header;
551 * Unique identifier of the trail.
553 struct GNUNET_HashCode trail_id;
556 * Direction of trail.
558 uint32_t trail_direction;
563 * P2P Trail Rejection Message.
565 struct PeerTrailRejectionMessage
568 * Type: #GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP_REJECTION
570 struct GNUNET_MessageHeader header;
573 * Peer which wants to set up the trail.
575 struct GNUNET_PeerIdentity source_peer;
578 * Peer which sent trail rejection message as it it congested.
580 struct GNUNET_PeerIdentity congested_peer;
583 * Peer identity closest to this value will be finger of
586 uint64_t ultimate_destination_finger_value;
589 * Is source_peer trying to setup the trail to its predecessor or finger.
591 uint32_t is_predecessor;
594 * Identifier for the trail that source peer is trying to setup.
596 struct GNUNET_HashCode trail_id;
599 * Relative time for which congested_peer will remain congested.
601 struct GNUNET_TIME_Relative congestion_time;
603 /* Trail_list from source_peer to peer which sent the message for trail setup
604 * to congested peer. This trail does NOT include source_peer.
605 struct GNUNET_PeerIdnetity trail[]*/
609 * P2P Add Trail Message.
611 struct PeerAddTrailMessage
614 * Type: #GNUNET_MESSAGE_TYPE_XDHT_P2P_ADD_TRAIL
616 struct GNUNET_MessageHeader header;
619 * Source of the routing trail.
621 struct GNUNET_PeerIdentity source_peer;
624 * Destination of the routing trail.
626 struct GNUNET_PeerIdentity destination_peer;
629 * Unique identifier of the trail from source_peer to destination_peer,
630 * NOT including the endpoints.
632 struct GNUNET_HashCode trail_id;
634 /* Trail from source peer to destination peer, NOT including them.
635 * struct GNUNET_PeerIdentity trail[]
639 GNUNET_NETWORK_STRUCT_END
642 * Linked list of messages to send to a particular other peer.
644 struct P2PPendingMessage
647 * Pointer to next item in the list
649 struct P2PPendingMessage *next;
652 * Pointer to previous item in the list
654 struct P2PPendingMessage *prev;
657 * Message importance level. FIXME: used? useful?
659 unsigned int importance;
662 * When does this message time out?
664 struct GNUNET_TIME_Absolute timeout;
667 * Actual message to be sent, allocated at the end of the struct:
668 * // msg = (cast) &pm[1];
669 * // memcpy (&pm[1], data, len);
671 const struct GNUNET_MessageHeader *msg;
676 * Entry in friend_peermap.
683 struct GNUNET_PeerIdentity id;
686 * Number of trails for which this friend is the first hop or if the friend
689 unsigned int trails_count;
692 * Count of outstanding messages for this friend.
694 unsigned int pending_count;
697 * In case not 0, then amount of time for which this friend is congested.
699 struct GNUNET_TIME_Absolute congestion_timestamp;
702 * Head of pending messages to be sent to this friend.
704 struct P2PPendingMessage *head;
707 * Tail of pending messages to be sent to this friend.
709 struct P2PPendingMessage *tail;
712 * Core handle for sending messages to this friend.
714 struct GNUNET_CORE_TransmitHandle *th;
719 * An individual element of the trail to reach to a finger.
724 * Pointer to next item in the list
726 struct Trail_Element *next;
729 * Pointer to prev item in the list
731 struct Trail_Element *prev;
734 * An element in this trail.
736 struct GNUNET_PeerIdentity peer;
740 * FIXME: removed first_friend_trails_count, need to write a function
741 * to calculate each time we need it. Else, keep a pointer to first
742 * friend of in the trail.
743 * Information about an individual trail.
750 struct Trail_Element *trail_head;
755 struct Trail_Element *trail_tail;
758 * Unique identifier of this trail.
760 struct GNUNET_HashCode trail_id;
763 * Length of trail pointed
765 unsigned int trail_length;
768 * Is there a valid trail entry.
770 unsigned int is_present;
774 * An entry in finger_table
781 struct GNUNET_PeerIdentity finger_identity;
784 * Is any finger stored at this finger index.
786 unsigned int is_present;
789 * Index in finger peer map
791 uint32_t finger_table_index;
794 * Number of trails setup so far for this finger.
795 * Should not cross MAXIMUM_TRAILS_PER_FINGER.
797 uint32_t trails_count;
800 * Array of trails to reach to this finger.
802 struct Trail trail_list[MAXIMUM_TRAILS_PER_FINGER];
807 * Data structure to keep track of closest peer seen so far in find_successor()
812 * Destination finger value.
814 uint64_t destination_finger_value;
817 * Is finger_value a predecessor or any other finger.
819 unsigned int is_predecessor;
822 * Trail id to reach to peer.
823 * In case peer is my identity or friend, it is set to 0.
825 struct GNUNET_HashCode trail_id;
828 * Next destination. In case of friend and my_identity , it is same as next_hop
829 * In case of finger it is finger identity.
831 struct GNUNET_PeerIdentity best_known_destination;
834 * In case best_known_destination is a finger, then first friend in the trail
835 * to reach to it. In other case, same as best_known_destination.
837 struct GNUNET_PeerIdentity next_hop;
842 * Data structure to store the trail chosen to reach to finger.
844 struct Selected_Finger_Trail
847 * First friend in the trail to reach finger.
849 struct FriendInfo friend;
852 * Identifier of this trail.
854 struct GNUNET_HashCode trail_id;
857 * Total number of peers in this trail.
859 unsigned int trail_length;
863 * Task that sends FIND FINGER TRAIL requests. This task is started when we have
864 * get our first friend.
866 static GNUNET_SCHEDULER_TaskIdentifier find_finger_trail_task;
869 * Identity of this peer.
871 static struct GNUNET_PeerIdentity my_identity;
874 * Peer map of all the friends of a peer
876 static struct GNUNET_CONTAINER_MultiPeerMap *friend_peermap;
879 * Array of all the fingers.
881 static struct FingerInfo finger_table [MAX_FINGERS];
886 static struct GNUNET_CORE_Handle *core_api;
889 * The current finger index that we have want to find trail to. We start the
890 * search with value = 0, i.e. successor and then go to PREDCESSOR_FINGER_ID
891 * and decrement it. For any index 63 <= index < 0, if finger is same as successor,
892 * we reset this index to 0.
894 static unsigned int current_search_finger_index;
898 * Called when core is ready to send a message we asked for
899 * out to the destination.
901 * @param cls the 'struct FriendInfo' of the target friend
902 * @param size number of bytes available in buf
903 * @param buf where the callee should write the message
904 * @return number of bytes written to buf
907 core_transmit_notify (void *cls, size_t size, void *buf)
909 struct FriendInfo *peer = cls;
911 struct P2PPendingMessage *pending;
916 while ((NULL != (pending = peer->head)) &&
917 (0 == GNUNET_TIME_absolute_get_remaining (pending->timeout).rel_value_us))
919 peer->pending_count--;
920 GNUNET_CONTAINER_DLL_remove (peer->head, peer->tail, pending);
921 GNUNET_free (pending);
925 /* no messages pending */
931 GNUNET_CORE_notify_transmit_ready (core_api, GNUNET_NO,
932 GNUNET_CORE_PRIO_BEST_EFFORT,
933 GNUNET_TIME_absolute_get_remaining
934 (pending->timeout), &peer->id,
935 ntohs (pending->msg->size),
936 &core_transmit_notify, peer);
937 GNUNET_break (NULL != peer->th);
941 while ((NULL != (pending = peer->head)) &&
942 (size - off >= (msize = ntohs (pending->msg->size))))
944 GNUNET_STATISTICS_update (GDS_stats,
946 ("# Bytes transmitted to other peers"), msize,
948 memcpy (&cbuf[off], pending->msg, msize);
950 peer->pending_count--;
951 GNUNET_CONTAINER_DLL_remove (peer->head, peer->tail, pending);
952 GNUNET_free (pending);
954 if (peer->head != NULL)
957 GNUNET_CORE_notify_transmit_ready (core_api, GNUNET_NO,
958 GNUNET_CORE_PRIO_BEST_EFFORT,
959 GNUNET_TIME_absolute_get_remaining
960 (pending->timeout), &peer->id, msize,
961 &core_transmit_notify, peer);
962 GNUNET_break (NULL != peer->th);
969 * Transmit all messages in the friend's message queue.
971 * @param peer message queue to process
974 process_friend_queue (struct FriendInfo *peer)
976 struct P2PPendingMessage *pending;
978 if (NULL == (pending = peer->head))
980 if (NULL != peer->th)
983 GNUNET_STATISTICS_update (GDS_stats,
985 ("# Bytes of bandwidth requested from core"),
986 ntohs (pending->msg->size), GNUNET_NO);
989 GNUNET_CORE_notify_transmit_ready (core_api, GNUNET_NO,
991 GNUNET_TIME_absolute_get_remaining
992 (pending->timeout), &peer->id,
993 ntohs (pending->msg->size),
994 &core_transmit_notify, peer);
995 GNUNET_break (NULL != peer->th);
1000 * Return friend corresponding to peer.
1005 GDS_NEIGHBOURS_get_friend (struct GNUNET_PeerIdentity peer)
1007 struct FriendInfo *friend;
1008 GNUNET_assert (NULL != (friend =
1009 GNUNET_CONTAINER_multipeermap_get (friend_peermap, &peer)));
1015 * Construct a trail setup message and forward it to target_friend
1016 * @param source_peer Peer which wants to setup the trail
1017 * @param ultimate_destination_finger_value Peer identity closest to this value
1018 * will be finger to @a source_peer
1019 * @param best_known_destination Best known destination (could be finger or friend)
1020 * which should get this message. In case it is
1021 * friend, then it is same as target_friend
1022 * @param target_friend Friend to which message is forwarded now.
1023 * @param trail_length Total number of peers in trail setup so far.
1024 * @param trail_peer_list Trail setup so far
1025 * @param is_predecessor Is @a source_peer looking for trail to a predecessor or not.
1026 * @param trail_id Unique identifier for the trail we are trying to setup.
1027 * @param intermediate_trail_id Trail id of intermediate trail to reach to
1028 * best_known_destination when its a finger. If not
1029 * used then set to 0.
1032 GDS_NEIGHBOURS_send_trail_setup (struct GNUNET_PeerIdentity source_peer,
1033 uint64_t ultimate_destination_finger_value,
1034 struct GNUNET_PeerIdentity best_known_destination,
1035 struct FriendInfo *target_friend,
1036 unsigned int trail_length,
1037 const struct GNUNET_PeerIdentity *trail_peer_list,
1038 unsigned int is_predecessor,
1039 struct GNUNET_HashCode trail_id,
1040 struct GNUNET_HashCode *intermediate_trail_id)
1042 struct P2PPendingMessage *pending;
1043 struct PeerTrailSetupMessage *tsm;
1044 struct GNUNET_PeerIdentity *peer_list;
1047 msize = sizeof (struct PeerTrailSetupMessage) +
1048 (trail_length * sizeof (struct GNUNET_PeerIdentity));
1050 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1056 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1058 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# P2P messages dropped due to full queue"),
1062 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1063 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1064 tsm = (struct PeerTrailSetupMessage *) &pending[1];
1065 pending->msg = &tsm->header;
1066 tsm->header.size = htons (msize);
1067 tsm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP);
1068 tsm->final_destination_finger_value = GNUNET_htonll (ultimate_destination_finger_value);
1069 tsm->source_peer = source_peer;
1070 tsm->best_known_destination = best_known_destination;
1071 tsm->is_predecessor = htonl (is_predecessor);
1072 tsm->trail_id = trail_id;
1074 if (NULL == intermediate_trail_id)
1075 memset (&tsm->intermediate_trail_id, 0, sizeof (tsm->intermediate_trail_id));
1077 tsm->intermediate_trail_id = *intermediate_trail_id;
1079 if (trail_length > 0)
1081 peer_list = (struct GNUNET_PeerIdentity *) &tsm[1];
1082 memcpy (peer_list, trail_peer_list, trail_length * sizeof(struct GNUNET_PeerIdentity));
1085 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1086 target_friend->pending_count++;
1087 process_friend_queue (target_friend);
1092 * Construct a trail setup result message and forward it to target friend.
1093 * @param querying_peer Peer which sent the trail setup request and should get
1095 * @param Finger Peer to which the trail has been setup to.
1096 * @param target_friend Friend to which this message should be forwarded.
1097 * @param trail_length Numbers of peers in the trail.
1098 * @param trail_peer_list Peers which are part of the trail from
1099 * querying_peer to Finger, NOT including them.
1100 * @param is_predecessor Is @a Finger predecessor to @a querying_peer ?
1101 * @param ultimate_destination_finger_value Value to which @a finger is the closest
1103 * @param trail_id Unique identifier of the trail.
1106 GDS_NEIGHBOURS_send_trail_setup_result (struct GNUNET_PeerIdentity querying_peer,
1107 struct GNUNET_PeerIdentity finger,
1108 struct FriendInfo *target_friend,
1109 unsigned int trail_length,
1110 const struct GNUNET_PeerIdentity *trail_peer_list,
1111 unsigned int is_predecessor,
1112 uint64_t ultimate_destination_finger_value,
1113 struct GNUNET_HashCode trail_id)
1115 struct P2PPendingMessage *pending;
1116 struct PeerTrailSetupResultMessage *tsrm;
1117 struct GNUNET_PeerIdentity *peer_list;
1120 msize = sizeof (struct PeerTrailSetupResultMessage) +
1121 (trail_length * sizeof (struct GNUNET_PeerIdentity));
1123 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1129 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1131 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# P2P messages dropped due to full queue"),
1135 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1136 pending->importance = 0;
1137 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1138 tsrm = (struct PeerTrailSetupResultMessage *) &pending[1];
1139 pending->msg = &tsrm->header;
1140 tsrm->header.size = htons (msize);
1141 tsrm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP_RESULT);
1142 tsrm->querying_peer = querying_peer;
1143 tsrm->finger_identity = finger;
1144 tsrm->is_predecessor = htonl (is_predecessor);
1145 tsrm->trail_id = trail_id;
1146 tsrm->ulitmate_destination_finger_value =
1147 GNUNET_htonll (ultimate_destination_finger_value);
1148 peer_list = (struct GNUNET_PeerIdentity *) &tsrm[1];
1149 if (trail_length > 0)
1151 memcpy (peer_list, trail_peer_list, trail_length * sizeof (struct GNUNET_PeerIdentity));
1153 /* Send the message to chosen friend. */
1154 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1155 target_friend->pending_count++;
1156 process_friend_queue (target_friend);
1161 * Send trail rejection message to target friend
1162 * @param source_peer Peer which is trying to setup the trail.
1163 * @param ultimate_destination_finger_value Peer closest to this value will be
1164 * @a source_peer's finger
1165 * @param congested_peer Peer which sent this message as it is congested.
1166 * @param is_predecessor Is source_peer looking for trail to a predecessor or not.
1167 * @param trail_peer_list Trails seen so far in trail setup before getting rejected
1168 * by congested_peer. This does NOT include @a source_peer
1169 * and congested_peer.
1170 * @param trail_length Total number of peers in trail_peer_list, NOT including
1171 * @a source_peer and @a congested_peer
1172 * @param trail_id Unique identifier of this trail.
1173 * @param congestion_timeout Duration given by congested peer as an estimate of
1174 * how long it may remain congested.
1177 GDS_NEIGHBOURS_send_trail_rejection (struct GNUNET_PeerIdentity source_peer,
1178 uint64_t ultimate_destination_finger_value,
1179 struct GNUNET_PeerIdentity congested_peer,
1180 unsigned int is_predecessor,
1181 const struct GNUNET_PeerIdentity *trail_peer_list,
1182 unsigned int trail_length,
1183 struct GNUNET_HashCode trail_id,
1184 struct FriendInfo *target_friend,
1185 const struct GNUNET_TIME_Relative congestion_timeout)
1187 struct PeerTrailRejectionMessage *trm;
1188 struct P2PPendingMessage *pending;
1189 struct GNUNET_PeerIdentity *peer_list;
1192 msize = sizeof (struct PeerTrailRejectionMessage) +
1193 (trail_length * sizeof (struct GNUNET_PeerIdentity));
1195 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1201 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1203 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# P2P messages dropped due to full queue"),
1207 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1208 pending->importance = 0;
1209 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1210 trm = (struct PeerTrailRejectionMessage *)&pending[1];
1211 pending->msg = &trm->header;
1212 trm->header.size = htons (msize);
1213 trm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP_REJECTION);
1214 trm->source_peer = source_peer;
1215 trm->congested_peer = congested_peer;
1216 trm->congestion_time = congestion_timeout;
1217 trm->is_predecessor = htonl (is_predecessor);
1218 trm->trail_id = trail_id;
1219 trm->ultimate_destination_finger_value =
1220 GNUNET_htonll (ultimate_destination_finger_value);
1222 peer_list = (struct GNUNET_PeerIdentity *) &trm[1];
1223 if (trail_length > 0)
1225 memcpy (peer_list, trail_peer_list, trail_length * sizeof (struct GNUNET_PeerIdentity));
1228 /* Send the message to chosen friend. */
1229 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1230 target_friend->pending_count++;
1231 process_friend_queue (target_friend);
1236 * Construct a verify successor message and forward it to target_friend.
1237 * @param source_peer Peer which wants to verify its successor.
1238 * @param successor Peer which is @a source_peer's current successor.
1239 * @param trail_id Unique Identifier of trail from @a source_peer to @a successor,
1240 * NOT including them.
1241 * @param trail List of peers which are part of trail to reach from @a source_peer
1242 * to @a successor, NOT including them.
1243 * @param trail_length Total number of peers in @a trail.
1244 * @param target_friend Next friend to get this message.
1247 GDS_NEIGHBOURS_send_verify_successor_message (struct GNUNET_PeerIdentity source_peer,
1248 struct GNUNET_PeerIdentity successor,
1249 struct GNUNET_HashCode trail_id,
1250 struct GNUNET_PeerIdentity *trail,
1251 unsigned int trail_length,
1252 struct FriendInfo *target_friend)
1254 struct PeerVerifySuccessorMessage *vsm;
1255 struct P2PPendingMessage *pending;
1256 struct GNUNET_PeerIdentity *peer_list;
1259 msize = sizeof (struct PeerVerifySuccessorMessage);
1260 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1266 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1268 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# P2P messages dropped due to full queue"),
1272 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1273 pending->importance = 0; /* FIXME */
1274 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1275 vsm = (struct PeerVerifySuccessorMessage *) &pending[1];
1276 pending->msg = &vsm->header;
1277 vsm->header.size = htons (msize);
1278 vsm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_VERIFY_SUCCESSOR);
1279 vsm->source_peer = source_peer;
1280 vsm->successor = successor;
1281 vsm->trail_id = trail_id;
1283 if (trail_length > 0)
1285 peer_list = (struct GNUNET_PeerIdentity *) &vsm[1];
1286 memcpy (peer_list, trail, trail_length * sizeof (struct GNUNET_PeerIdentity));
1289 /* Send the message to chosen friend. */
1290 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1291 target_friend->pending_count++;
1292 process_friend_queue (target_friend);
1297 * FIXME: In every function we pass target friend except for this one.
1298 * so, either change everything or this one. also, should se just store
1299 * the pointer to friend in routing table rather than gnunet_peeridentity.
1300 * if yes then we should keep friend info in.h andmake lot of changes.
1301 * Construct a trail teardown message and forward it to target friend.
1302 * @param trail_id Unique identifier of the trail.
1303 * @param trail_direction Direction of trail.
1304 * @param target_friend Friend to get this message.
1307 GDS_NEIGHBOURS_send_trail_teardown (struct GNUNET_HashCode trail_id,
1308 unsigned int trail_direction,
1309 struct GNUNET_PeerIdentity *peer)
1311 struct PeerTrailTearDownMessage *ttdm;
1312 struct P2PPendingMessage *pending;
1313 struct FriendInfo *target_friend;
1316 msize = sizeof (struct PeerTrailTearDownMessage);
1318 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1324 GNUNET_assert (NULL != (target_friend =
1325 GNUNET_CONTAINER_multipeermap_get (friend_peermap, peer)));
1327 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1329 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# P2P messages dropped due to full queue"),
1333 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1334 pending->importance = 0; /* FIXME */
1335 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1336 ttdm = (struct PeerTrailTearDownMessage *) &pending[1];
1337 pending->msg = &ttdm->header;
1338 ttdm->header.size = htons (msize);
1339 ttdm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_TEARDOWN);
1340 ttdm->trail_id = trail_id;
1341 ttdm->trail_direction = htonl (trail_direction);
1343 /* Send the message to chosen friend. */
1345 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1346 target_friend->pending_count++;
1347 process_friend_queue (target_friend);
1352 * Construct a verify successor result message and send it to target_friend
1353 * @param querying_peer Peer which sent the verify successor message.
1354 * @param source_successor Current_successor of @a querying_peer.
1355 * @param current_predecessor Current predecessor of @a successor. Could be same
1356 * or different from @a querying_peer.
1357 * @param trail_id Unique identifier of the trail from @a querying_peer to
1358 * @a successor, NOT including them.
1359 * @param trail List of peers which are part of trail from @a querying_peer to
1360 * @a successor, NOT including them.
1361 * @param trail_length Total number of peers in @a trail
1362 * @param trail_direction Direction in which we are sending the message. In this
1363 * case we are sending result from @a successor to @a querying_peer.
1364 * @param target_friend Next friend to get this message.
1367 GDS_NEIGHBOURS_send_verify_successor_result (struct GNUNET_PeerIdentity querying_peer,
1368 struct GNUNET_PeerIdentity current_successor,
1369 struct GNUNET_PeerIdentity probable_successor,
1370 struct GNUNET_HashCode trail_id,
1371 const struct GNUNET_PeerIdentity *trail,
1372 unsigned int trail_length,
1373 enum GDS_ROUTING_trail_direction trail_direction,
1374 struct FriendInfo *target_friend)
1376 struct PeerVerifySuccessorResultMessage *vsmr;
1377 struct P2PPendingMessage *pending;
1378 struct GNUNET_PeerIdentity *peer_list;
1381 msize = sizeof (struct PeerVerifySuccessorResultMessage) +
1382 (trail_length * sizeof(struct GNUNET_PeerIdentity));
1384 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1390 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1392 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# P2P messages dropped due to full queue"),
1396 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1397 pending->importance = 0; /* FIXME */
1398 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1399 vsmr = (struct PeerVerifySuccessorResultMessage *) &pending[1];
1400 pending->msg = &vsmr->header;
1401 vsmr->header.size = htons (msize);
1402 vsmr->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_VERIFY_SUCCESSOR_RESULT);
1403 vsmr->querying_peer = querying_peer;
1404 vsmr->current_successor = current_successor;
1405 vsmr->probable_successor = probable_successor;
1406 vsmr->trail_direction = htonl (trail_direction);
1407 vsmr->trail_id = trail_id;
1409 if (trail_length > 0)
1411 peer_list = (struct GNUNET_PeerIdentity *) &vsmr[1];
1412 memcpy (peer_list, trail, trail_length * sizeof (struct GNUNET_PeerIdentity));
1415 /* Send the message to chosen friend. */
1416 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1417 target_friend->pending_count++;
1418 process_friend_queue (target_friend);
1423 * Construct a notify new successor message and send it to target_friend
1424 * @param source_peer Peer which wants to notify to its new successor that it
1425 * could be its predecessor.
1426 * @param successor New successor of @a source_peer
1427 * @param successor_trail List of peers in Trail to reach from
1428 * @a source_peer to @a new_successor, NOT including
1430 * @param successor_trail_length Total number of peers in @a new_successor_trail.
1431 * @param successor_trail_id Unique identifier of @a new_successor_trail.
1432 * @param target_friend Next friend to get this message.
1435 GDS_NEIGHBOURS_send_notify_new_successor (struct GNUNET_PeerIdentity source_peer,
1436 struct GNUNET_PeerIdentity successor,
1437 const struct GNUNET_PeerIdentity *successor_trail,
1438 unsigned int successor_trail_length,
1439 struct GNUNET_HashCode succesor_trail_id,
1440 struct FriendInfo *target_friend)
1442 struct PeerNotifyNewSuccessorMessage *nsm;
1443 struct P2PPendingMessage *pending;
1444 struct GNUNET_PeerIdentity *peer_list;
1447 msize = sizeof (struct PeerNotifyNewSuccessorMessage) +
1448 (successor_trail_length * sizeof(struct GNUNET_PeerIdentity));
1450 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1456 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1458 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# P2P messages dropped due to full queue"),
1462 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1463 pending->importance = 0; /* FIXME */
1464 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1465 nsm = (struct PeerNotifyNewSuccessorMessage *) &pending[1];
1466 pending->msg = &nsm->header;
1467 nsm->header.size = htons (msize);
1468 nsm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_NOTIFY_NEW_SUCCESSOR);
1469 nsm->new_successor = successor;
1470 nsm->source_peer = source_peer;
1471 nsm->trail_id = succesor_trail_id;
1473 if (successor_trail_length > 0)
1475 peer_list = (struct GNUNET_PeerIdentity *) &nsm[1];
1476 memcpy (peer_list, successor_trail,
1477 successor_trail_length * sizeof (struct GNUNET_PeerIdentity));
1480 /* Send the message to chosen friend. */
1481 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1482 target_friend->pending_count++;
1483 process_friend_queue (target_friend);
1488 * Construct an add_trail message and send it to target_friend
1489 * @param source_peer Source of the trail.
1490 * @param destination_peer Destination of the trail.
1491 * @param trail_id Unique identifier of the trail from
1492 * @a source_peer to @a destination_peer, NOT including the endpoints.
1493 * @param trail List of peers in Trail from @a source_peer to @a destination_peer,
1494 * NOT including the endpoints.
1495 * @param trail_length Total number of peers in @a trail.
1496 * @param target_friend Next friend to get this message.
1499 GDS_NEIGHBOURS_send_add_trail (struct GNUNET_PeerIdentity source_peer,
1500 struct GNUNET_PeerIdentity destination_peer,
1501 struct GNUNET_HashCode trail_id,
1502 const struct GNUNET_PeerIdentity *trail,
1503 unsigned int trail_length,
1504 struct FriendInfo *target_friend)
1506 struct PeerAddTrailMessage *adm;
1507 struct GNUNET_PeerIdentity *peer_list;
1508 struct P2PPendingMessage *pending;
1511 msize = sizeof (struct PeerAddTrailMessage) +
1512 (trail_length * sizeof(struct GNUNET_PeerIdentity));
1514 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1520 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1522 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# P2P messages dropped due to full queue"),
1526 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1527 pending->importance = 0; /* FIXME */
1528 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1529 adm = (struct PeerAddTrailMessage *) &pending[1];
1530 pending->msg = &adm->header;
1531 adm->header.size = htons (msize);
1532 adm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_ADD_TRAIL);
1533 adm->source_peer = source_peer;
1534 adm->destination_peer = destination_peer;
1535 adm->trail_id = trail_id;
1537 if (trail_length > 0)
1539 peer_list = (struct GNUNET_PeerIdentity *)&adm[1];
1540 memcpy (peer_list, trail, sizeof (struct GNUNET_PeerIdentity) * trail_length);
1542 /* Send the message to chosen friend. */
1543 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1544 target_friend->pending_count++;
1545 process_friend_queue (target_friend);
1551 * Construct a trail compression message and send it to target_friend.
1552 * @param source_peer Source of the trail.
1553 * @param trail_id Unique identifier of trail.
1554 * @param first_friend First hop in compressed trail to reach from source to finger
1555 * @param target_friend Next friend to get this message.
1558 GDS_NEIGHBOURS_send_trail_compression (struct GNUNET_PeerIdentity source_peer,
1559 struct GNUNET_HashCode trail_id,
1560 struct GNUNET_PeerIdentity first_friend,
1561 struct FriendInfo *target_friend)
1563 struct P2PPendingMessage *pending;
1564 struct PeerTrailCompressionMessage *tcm;
1567 msize = sizeof (struct PeerTrailCompressionMessage);
1569 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1575 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1577 GNUNET_STATISTICS_update (GDS_stats,
1578 gettext_noop ("# P2P messages dropped due to full queue"),
1582 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1583 pending->importance = 0; /* FIXME */
1584 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1585 tcm = (struct PeerTrailCompressionMessage *) &pending[1];
1586 pending->msg = &tcm->header;
1587 tcm->header.size = htons (msize);
1588 tcm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_COMPRESSION);
1589 tcm->source_peer = source_peer;
1590 tcm->new_first_friend = first_friend;
1591 tcm->trail_id = trail_id;
1593 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1594 target_friend->pending_count++;
1595 process_friend_queue (target_friend);
1601 * Search my location in trail.
1602 * @param trail List of peers
1603 * @return my_index if found
1604 * -1 if no entry found.
1607 search_my_index (const struct GNUNET_PeerIdentity *trail,
1612 for (i = 0; i < trail_length; i++)
1614 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &trail[i]))
1623 * Check if the friend is congested or have reached maximum number of trails
1624 * it can be part of of.
1625 * @param friend Friend to be checked.
1626 * @return #GNUNET_YES if friend is not congested or have not crossed threshold.
1627 * #GNUNET_NO if friend is either congested or have crossed threshold
1630 is_friend_congested (struct FriendInfo *friend)
1632 if ((friend->trails_count < TRAILS_THROUGH_FRIEND_THRESHOLD) &&
1633 ((0 == GNUNET_TIME_absolute_get_remaining
1634 (friend->congestion_timestamp).rel_value_us)))
1642 * FIXME; not handling the wrap around logic correctly.
1643 * Select closest finger to value.
1644 * @param peer1 First peer
1645 * @param peer2 Second peer
1646 * @param value Value to be compare
1647 * @return Closest peer
1649 static struct GNUNET_PeerIdentity *
1650 select_closest_finger (struct GNUNET_PeerIdentity *peer1,
1651 struct GNUNET_PeerIdentity *peer2,
1654 uint64_t peer1_value;
1655 uint64_t peer2_value;
1657 memcpy (&peer1_value, peer1, sizeof (uint64_t));
1658 memcpy (&peer2_value, peer2, sizeof (uint64_t));
1659 peer1_value = GNUNET_ntohll (peer1_value);
1660 peer2_value = GNUNET_ntohll (peer2_value);
1661 value = GNUNET_ntohll (value); //FIXME: Is it correct to do it here?
1662 // we do it when we get from the network.
1664 if (peer1_value == value)
1669 if (peer2_value == value)
1674 if (peer2_value < peer1_value)
1676 if ((peer2_value < value) && (value < peer1_value))
1680 else if (((peer1_value < value) && (value < PEER_IDENTITES_WRAP_AROUND)) ||
1681 ((0 < value) && (value < peer2_value)))
1687 if (peer1_value < peer2_value)
1689 if ((peer1_value < value) && (value < peer2_value))
1693 else if (((peer2_value < value) && (value < PEER_IDENTITES_WRAP_AROUND)) ||
1694 ((0 < value) && (value < peer1_value)))
1704 * Select closest predecessor to value.
1705 * @param peer1 First peer
1706 * @param peer2 Second peer
1707 * @param value Value to be compare
1708 * @return Peer which precedes value in the network.
1710 static struct GNUNET_PeerIdentity *
1711 select_closest_predecessor (struct GNUNET_PeerIdentity *peer1,
1712 struct GNUNET_PeerIdentity *peer2,
1715 uint64_t peer1_value;
1716 uint64_t peer2_value;
1718 memcpy (&peer1_value, peer1, sizeof (uint64_t));
1719 memcpy (&peer2_value, peer2, sizeof (uint64_t));
1720 peer1_value = GNUNET_ntohll (peer1_value);
1721 peer2_value = GNUNET_ntohll (peer2_value);
1723 if (peer1_value == value)
1726 if (peer2_value == value)
1729 if (peer1_value < peer2_value)
1731 if ((peer1_value < value) && (value < peer2_value))
1733 else if (((peer2_value < value) && (value < PEER_IDENTITES_WRAP_AROUND)) ||
1734 ((PEER_IDENTITES_WRAP_AROUND > value) && (value < peer1_value)))
1738 if (peer2_value < peer1_value)
1740 if ((peer2_value < value) && (value < peer1_value))
1742 else if (((peer1_value < value) && (value < PEER_IDENTITES_WRAP_AROUND)) ||
1743 ((PEER_IDENTITES_WRAP_AROUND > value) && (value < peer2_value)))
1751 * Select the closest peer among two peers (which should not be same)
1752 * with respect to value and finger_table_index
1753 * NOTE: peer1 != peer2
1754 * @param peer1 First peer
1755 * @param peer2 Second peer
1756 * @param value Value relative to which we find the closest
1757 * @param is_predecessor Is value a predecessor or any other finger.
1758 * @return Closest peer among two peers.
1760 static struct GNUNET_PeerIdentity *
1761 select_closest_peer (struct GNUNET_PeerIdentity *peer1,
1762 struct GNUNET_PeerIdentity *peer2,
1764 unsigned int is_predecessor)
1766 struct GNUNET_PeerIdentity *closest_peer;
1768 if (1 == is_predecessor)
1769 closest_peer = select_closest_predecessor (peer1, peer2, value);
1771 closest_peer = select_closest_finger (peer1, peer2, value);
1773 return closest_peer;
1778 * Iterate over the list of all the trails of a finger. In case the first
1779 * friend to reach the finger has reached trail threshold or is congested,
1780 * then don't select it. In case there multiple available good trails to reach
1781 * to Finger, choose the one with shortest trail length.
1782 * Note: We use length as parameter. But we can use any other suitable parameter
1784 * @param finger Finger
1785 * @return struct Selected_Finger_Trail which contains the first friend , trail id
1786 * and trail length. NULL in case none of the trails are free.
1788 static struct Selected_Finger_Trail *
1789 select_finger_trail (struct FingerInfo *finger)
1791 struct FriendInfo *friend;
1792 struct Trail *iterator;
1793 struct Selected_Finger_Trail *finger_trail;
1795 unsigned int flag = 0;
1798 finger_trail = GNUNET_new (struct Selected_Finger_Trail);
1800 /* It can never happen that we have a finger (which is not a friend or my identity),
1801 and we don't have a trail to reach to it. */
1802 GNUNET_assert (finger->trails_count > 0);
1804 for (i = 0; i < finger->trails_count; i++)
1806 iterator = &finger->trail_list[i];
1808 /* No trail stored at this index. */
1809 if (GNUNET_NO == iterator->is_present)
1812 friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
1813 &iterator->trail_head->peer);
1815 /* First friend to reach trail is not free. */
1816 if (GNUNET_YES == is_friend_congested (friend))
1821 /* This is the first time we enter the loop. Set finger trail length to
1822 * trail length of this trail. */
1826 finger_trail->trail_length = iterator->trail_length;
1828 else if (finger_trail->trail_length > iterator->trail_length)
1830 /* Check if the trail length of this trail is least seen so far. If yes then
1831 set finger_trail to this trail.*/
1832 finger_trail->friend = *friend;
1833 finger_trail->trail_id = iterator->trail_id;
1834 finger_trail->trail_length = iterator->trail_length;
1838 /* All the first friend in all the trails to reach to finger are either
1839 congested or have crossed trail threshold. */
1840 if (j == finger->trails_count)
1843 return finger_trail;
1848 * Compare FINGER entry with current successor. If finger's first friend of all
1849 * its trail is not congested and has not crossed trail threshold, then check
1850 * if finger peer identity is closer to final_destination_finger_value than
1851 * current_successor. If yes then update current_successor.
1852 * @param current_successor[in/out]
1855 static struct Closest_Peer *
1856 compare_finger_and_current_successor (struct Closest_Peer *current_closest_peer)
1858 struct FingerInfo *finger;
1859 struct FriendInfo *friend;
1860 struct GNUNET_PeerIdentity *closest_peer;
1861 struct Selected_Finger_Trail *finger_trail;
1864 /* Iterate over finger table. */
1865 for (i = 0; i < MAX_FINGERS; i++)
1867 finger = &finger_table[i];
1869 /* No valid entry at this index, go to next element.*/
1870 if (GNUNET_NO == finger->is_present)
1873 /* If my identity is same as current closest peer then don't consider me*/
1875 GNUNET_CRYPTO_cmp_peer_identity (&finger->finger_identity,
1876 ¤t_closest_peer->best_known_destination))
1879 /* If I am my own finger, then ignore this finger. */
1880 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&finger->finger_identity,
1884 /* If finger is a friend, then do nothing. As we have already checked
1885 * for each friend in compare_friend_and_current_successor(). */
1887 (friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
1888 &finger->finger_identity)))
1891 /* We have a finger which not a friend, not my identity */
1892 /* Choose one of the trail to reach to finger. */
1893 finger_trail = select_finger_trail (finger);
1895 /* In case no trail found, ignore this finger. */
1896 if (NULL == finger_trail)
1899 closest_peer = select_closest_peer (&finger->finger_identity,
1900 ¤t_closest_peer->best_known_destination,
1901 current_closest_peer->destination_finger_value,
1902 current_closest_peer->is_predecessor);
1903 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&finger->finger_identity,
1906 current_closest_peer->best_known_destination = finger->finger_identity;
1907 current_closest_peer->next_hop = finger_trail->friend.id;
1908 current_closest_peer->trail_id = finger_trail->trail_id;
1912 return current_closest_peer;
1917 * Compare friend entry with current successor.
1918 * If friend identity and current_successor is same, then do nothing.
1919 * If friend is not congested and has not crossed trail threshold, then check
1920 * if friend peer identity is closer to final_destination_finger_value than
1921 * current_successor. If yes then update current_successor.
1922 * @param cls closure
1923 * @param key current public key
1924 * @param value struct Closest_Peer
1925 * @return #GNUNET_YES if we should continue to iterate,
1926 * #GNUNET_NO if not.
1929 compare_friend_and_current_closest_peer (void *cls,
1930 const struct GNUNET_PeerIdentity *key,
1933 struct FriendInfo *friend = value;
1934 struct Closest_Peer *current_closest_peer = cls;
1935 struct GNUNET_PeerIdentity *closest_peer;
1937 /* If friend is either congested or has crossed threshold, then don't consider
1939 if (GNUNET_YES == is_friend_congested (friend))
1942 /* If current_closest_peer and friend identity are same, then do nothing.*/
1944 GNUNET_CRYPTO_cmp_peer_identity (&friend->id,
1945 ¤t_closest_peer->best_known_destination))
1948 closest_peer = select_closest_peer (&friend->id,
1949 ¤t_closest_peer->best_known_destination,
1950 current_closest_peer->destination_finger_value,
1951 current_closest_peer->is_predecessor);
1953 /* Is friend the closest successor? */
1954 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&friend->id, closest_peer))
1956 current_closest_peer->best_known_destination = friend->id;
1957 current_closest_peer->next_hop = friend->id;
1965 * Initialize current_successor to my_identity.
1966 * @param my_identity My peer identity
1967 * @return current_successor
1969 static struct Closest_Peer *
1970 init_current_successor (struct GNUNET_PeerIdentity my_identity,
1971 uint64_t destination_finger_value,
1972 unsigned int is_predecessor)
1974 struct Closest_Peer *current_closest_peer;
1976 current_closest_peer = GNUNET_new (struct Closest_Peer);
1977 memset (¤t_closest_peer->trail_id, 0, sizeof (current_closest_peer->trail_id));
1978 current_closest_peer->destination_finger_value = destination_finger_value;
1979 current_closest_peer->is_predecessor = is_predecessor;
1980 current_closest_peer->next_hop = my_identity;
1981 current_closest_peer->best_known_destination = my_identity;
1983 return current_closest_peer;
1988 * Find the successor for destination_finger_value among my_identity, all my
1989 * friend and all my fingers. Don't consider friends or fingers which are either
1990 * congested or have crossed the threshold.
1991 * NOTE: In case a friend is also a finger, then it is always chosen as friend
1993 * @param destination_finger_value Peer closest to this value will be the next successor.
1994 * @param local_best_known_destination[out] Updated to my_identity if I am the
1995 * final destination. Updated to friend
1996 * identity in case a friend is successor,
1997 * updated to finger in case finger is the
1999 * @param new_intermediate_trail_id[out] In case a finger is the
2000 * @a local_best_known_destination,
2001 * then it is the trail to reach it. Else
2003 * @param is_predecessor Are we looking for predecessor or finger?
2004 * @return Next hop to reach to local_best_known_destination. In case my_identity
2005 * or a friend is a local_best_known_destination, then
2006 * next_hop = local_best_known_destination. Else
2007 * next_hop is the first friend to reach to finger (local_best_known_destination)
2009 static struct GNUNET_PeerIdentity *
2010 find_successor (uint64_t destination_finger_value,
2011 struct GNUNET_PeerIdentity *local_best_known_destination,
2012 struct GNUNET_HashCode *new_intermediate_trail_id,
2013 unsigned int is_predecessor)
2015 struct Closest_Peer *current_closest_peer;
2016 struct GNUNET_PeerIdentity *next_hop;
2018 /* Initialize current_successor to my_identity. */
2019 current_closest_peer = init_current_successor (my_identity,
2020 destination_finger_value,
2023 /* Compare each friend entry with current_successor and update current_successor
2024 * with friend if its closest. */
2027 GNUNET_CONTAINER_multipeermap_iterate (friend_peermap,
2028 &compare_friend_and_current_closest_peer,
2029 current_closest_peer));
2031 /* Compare each finger entry with current_successor and update current_successor
2032 * with finger if its closest. */
2033 compare_finger_and_current_successor (current_closest_peer);
2035 *local_best_known_destination = current_closest_peer->best_known_destination;
2036 new_intermediate_trail_id = ¤t_closest_peer->trail_id;
2037 next_hop = GNUNET_new (struct GNUNET_PeerIdentity);
2038 *next_hop = current_closest_peer->next_hop;
2045 * Construct a Put message and send it to target_peer.
2046 * @param key Key for the content
2047 * @param block_type Type of the block
2048 * @param options Routing options
2049 * @param desired_replication_level Desired replication count
2050 * @param best_known_dest Peer to which this message should reach eventually,
2051 * as it is best known destination to me.
2052 * @param intermediate_trail_id Trail id in case
2053 * @param target_peer Peer to which this message will be forwarded.
2054 * @param hop_count Number of hops traversed so far.
2055 * @param put_path_length Total number of peers in @a put_path
2056 * @param put_path Number of peers traversed so far
2057 * @param expiration_time When does the content expire
2058 * @param data Content to store
2059 * @param data_size Size of content @a data in bytes
2062 GDS_NEIGHBOURS_send_put (const struct GNUNET_HashCode *key,
2063 enum GNUNET_BLOCK_Type block_type,
2064 enum GNUNET_DHT_RouteOption options,
2065 uint32_t desired_replication_level,
2066 struct GNUNET_PeerIdentity *best_known_dest,
2067 struct GNUNET_HashCode *intermediate_trail_id,
2068 struct GNUNET_PeerIdentity *target_peer,
2070 uint32_t put_path_length,
2071 struct GNUNET_PeerIdentity *put_path,
2072 struct GNUNET_TIME_Absolute expiration_time,
2073 const void *data, size_t data_size)
2075 struct PeerPutMessage *ppm;
2076 struct P2PPendingMessage *pending;
2077 struct FriendInfo *target_friend;
2078 struct GNUNET_PeerIdentity *pp;
2079 struct GNUNET_PeerIdentity local_best_known_dest;
2082 msize = put_path_length * sizeof (struct GNUNET_PeerIdentity) + data_size +
2083 sizeof (struct PeerPutMessage);
2085 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
2087 put_path_length = 0;
2088 msize = data_size + sizeof (struct PeerPutMessage);
2091 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
2097 /* This is the first call made from clients file. So, we should search for the
2099 if (NULL == target_peer)
2102 struct GNUNET_PeerIdentity *next_hop;
2104 memcpy (&key_value, key, sizeof (uint64_t));
2105 key_value = GNUNET_ntohll (key_value);
2107 next_hop = find_successor (key_value, &local_best_known_dest,
2108 intermediate_trail_id, GDS_FINGER_TYPE_NON_PREDECESSOR);
2109 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&local_best_known_dest, &my_identity))
2111 /* I am the destination but we have already done datacache_put in client file. */
2115 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop);
2116 GNUNET_free (next_hop);
2120 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, target_peer);
2122 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
2123 pending->timeout = expiration_time;
2124 ppm = (struct PeerPutMessage *) &pending[1];
2125 pending->msg = &ppm->header;
2126 ppm->header.size = htons (msize);
2127 ppm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_PUT);
2128 ppm->options = htonl (options);
2129 ppm->block_type = htonl (block_type);
2130 ppm->hop_count = htonl (hop_count + 1);
2131 ppm->desired_replication_level = htonl (desired_replication_level);
2132 ppm->put_path_length = htonl (put_path_length);
2133 ppm->expiration_time = GNUNET_TIME_absolute_hton (expiration_time);
2134 if (NULL == best_known_dest)
2135 ppm->best_known_destination = local_best_known_dest;
2137 ppm->best_known_destination = *best_known_dest;
2139 if (NULL == intermediate_trail_id)
2140 memset (&ppm->intermediate_trail_id, 0, sizeof (ppm->intermediate_trail_id));
2142 ppm->intermediate_trail_id = *intermediate_trail_id;
2143 pp = (struct GNUNET_PeerIdentity *) &ppm[1];
2144 if (put_path_length != 0)
2146 memcpy (pp, put_path,
2147 sizeof (struct GNUNET_PeerIdentity) * put_path_length);
2149 memcpy (&pp[put_path_length], data, data_size);
2151 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
2152 target_friend->pending_count++;
2153 process_friend_queue (target_friend);
2158 * Construct a Get message and send it to target_peer.
2159 * @param key Key for the content
2160 * @param block_type Type of the block
2161 * @param options Routing options
2162 * @param desired_replication_level Desired replication count
2163 * @param best_known_dest Peer which should get this message. Same as target peer
2164 * if best_known_dest is a friend else its a finger.
2165 * @param intermediate_trail_id Trail id to reach to @a best_known_dest
2166 * in case it is a finger else set to 0.
2167 * @param target_peer Peer to which this message will be forwarded.
2168 * @param hop_count Number of hops traversed so far.
2169 * @param data Content to store
2170 * @param data_size Size of content @a data in bytes
2171 * @param get_path_length Total number of peers in @a get_path
2172 * @param get_path Number of peers traversed so far
2175 GDS_NEIGHBOURS_send_get (const struct GNUNET_HashCode *key,
2176 enum GNUNET_BLOCK_Type block_type,
2177 enum GNUNET_DHT_RouteOption options,
2178 uint32_t desired_replication_level,
2179 const struct GNUNET_PeerIdentity *best_known_dest,
2180 struct GNUNET_HashCode *intermediate_trail_id,
2181 struct GNUNET_PeerIdentity *target_peer,
2183 uint32_t get_path_length,
2184 struct GNUNET_PeerIdentity *get_path)
2186 struct PeerGetMessage *pgm;
2187 struct P2PPendingMessage *pending;
2188 struct FriendInfo *target_friend;
2189 struct GNUNET_PeerIdentity local_best_known_dest;
2190 struct GNUNET_PeerIdentity *gp;
2193 msize = sizeof (struct PeerGetMessage) +
2194 (get_path_length * sizeof (struct GNUNET_PeerIdentity));
2196 /* In this case we don't make get_path_length = 0, as we need get path to
2197 * return the message back to querying client. */
2198 if (msize > GNUNET_SERVER_MAX_MESSAGE_SIZE)
2203 /* This is the first time we got request from our own client file. */
2204 if (NULL == target_peer)
2206 struct GNUNET_PeerIdentity *next_hop;
2209 memcpy (&key_value, key, sizeof (uint64_t));
2210 key_value = GNUNET_ntohll (key_value);
2212 /* Find the next destination to forward the packet. */
2213 next_hop = find_successor (key_value, &local_best_known_dest,
2214 intermediate_trail_id, GDS_FINGER_TYPE_NON_PREDECESSOR);
2216 /* I am the destination. I have the data. */
2217 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&my_identity,
2218 &local_best_known_dest))
2220 GDS_DATACACHE_handle_get (key,block_type, NULL, 0,
2221 NULL, 0, 1, &my_identity, NULL,&my_identity);
2227 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop);
2229 GNUNET_free (next_hop);
2233 local_best_known_dest = *best_known_dest;
2234 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, target_peer);
2237 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
2238 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
2239 pending->importance = 0; /* FIXME */
2240 pgm = (struct PeerGetMessage *) &pending[1];
2241 pending->msg = &pgm->header;
2242 pgm->header.size = htons (msize);
2243 pgm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_GET);
2244 pgm->get_path_length = htonl (get_path_length);
2245 pgm->best_known_destination = local_best_known_dest;
2248 if (NULL == intermediate_trail_id)
2249 memset ((void *)&pgm->intermediate_trail_id, 0, sizeof (pgm->intermediate_trail_id));
2251 pgm->intermediate_trail_id = *intermediate_trail_id;
2252 pgm->hop_count = htonl (hop_count + 1);
2253 gp = (struct GNUNET_PeerIdentity *) &pgm[1];
2255 if (get_path_length != 0)
2257 memcpy (gp, get_path, get_path_length * sizeof (struct GNUNET_PeerIdentity));
2260 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
2261 target_friend->pending_count++;
2262 process_friend_queue (target_friend);
2267 * Send the get result to requesting client.
2268 * @param key Key of the requested data.
2269 * @param type Block type
2270 * @param target_peer Next peer to forward the message to.
2271 * @param source_peer Peer which has the data for the key.
2272 * @param put_path_length Number of peers in @a put_path
2273 * @param put_path Path taken to put the data at its stored location.
2274 * @param get_path_length Number of peers in @a get_path
2275 * @param get_path Path taken to reach to the location of the key.
2276 * @param expiration When will this result expire?
2277 * @param data Payload to store
2278 * @param data_size Size of the @a data
2281 GDS_NEIGHBOURS_send_get_result (const struct GNUNET_HashCode *key,
2282 enum GNUNET_BLOCK_Type type,
2283 const struct GNUNET_PeerIdentity *target_peer,
2284 const struct GNUNET_PeerIdentity *source_peer,
2285 unsigned int put_path_length,
2286 const struct GNUNET_PeerIdentity *put_path,
2287 unsigned int get_path_length,
2288 const struct GNUNET_PeerIdentity *get_path,
2289 struct GNUNET_TIME_Absolute expiration,
2290 const void *data, size_t data_size)
2292 struct PeerGetResultMessage *get_result;
2293 struct GNUNET_PeerIdentity *paths;
2294 struct P2PPendingMessage *pending;
2295 struct FriendInfo *target_friend;
2296 int current_path_index;
2299 msize = (put_path_length + get_path_length )* sizeof (struct GNUNET_PeerIdentity) +
2301 sizeof (struct PeerGetResultMessage);
2303 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
2309 current_path_index = 0;
2310 if(get_path_length > 0)
2312 current_path_index = search_my_index(get_path, get_path_length);
2313 if (-1 == current_path_index)
2319 if (0 == current_path_index)
2321 GDS_CLIENTS_handle_reply (expiration, key, get_path_length,
2322 get_path, put_path_length,
2323 put_path, type, data_size, data);
2327 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
2328 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
2329 pending->importance = 0;
2330 get_result = (struct PeerGetResultMessage *)&pending[1];
2331 pending->msg = &get_result->header;
2332 get_result->header.size = htons (msize);
2333 get_result->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_GET_RESULT);
2334 get_result->key = *key;
2335 get_result->querying_peer = *source_peer;
2336 get_result->expiration_time = expiration;
2337 get_result->get_path_length = htonl (get_path_length);
2338 get_result->put_path_length = htonl (put_path_length);
2339 paths = (struct GNUNET_PeerIdentity *)&get_result[1];
2340 memcpy (paths, put_path,
2341 put_path_length * sizeof (struct GNUNET_PeerIdentity));
2342 memcpy (&paths[put_path_length], get_path,
2343 get_path_length * sizeof (struct GNUNET_PeerIdentity));
2344 memcpy (&paths[put_path_length + get_path_length], data, data_size);
2346 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2347 &get_path[current_path_index - 1]);
2348 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
2349 target_friend->pending_count++;
2350 process_friend_queue (target_friend);
2355 * Randomly choose one of your friends (which is not congested and have not crossed
2356 * trail threshold) from the friends_peer map
2357 * @return Friend Randomly chosen friend.
2358 * NULL in case friend peermap is empty, or all the friends are either
2359 * congested or have crossed trail threshold.
2361 static struct FriendInfo *
2362 select_random_friend ()
2364 unsigned int current_size;
2367 struct GNUNET_CONTAINER_MultiPeerMapIterator *iter;
2368 struct GNUNET_PeerIdentity key_ret;
2369 struct FriendInfo *friend;
2371 current_size = GNUNET_CONTAINER_multipeermap_size (friend_peermap);
2374 if (0 == current_size)
2377 index = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, current_size);
2378 iter = GNUNET_CONTAINER_multipeermap_iterator_create (friend_peermap);
2380 /* Iterate till you don't reach to index. */
2381 for (j = 0; j < index ; j++)
2382 GNUNET_assert (GNUNET_YES ==
2383 GNUNET_CONTAINER_multipeermap_iterator_next (iter, NULL, NULL));
2386 /* Reset the index in friend peermap to 0 as we reached to the end. */
2387 if (j == current_size)
2390 GNUNET_CONTAINER_multipeermap_iterator_destroy (iter);
2391 iter = GNUNET_CONTAINER_multipeermap_iterator_create (friend_peermap);
2395 /* Get the friend stored at the index, j*/
2396 GNUNET_assert (GNUNET_YES ==
2397 GNUNET_CONTAINER_multipeermap_iterator_next (iter,
2399 (const void **)&friend));
2401 /* This friend is not congested and has not crossed trail threshold. */
2402 if ((TRAILS_THROUGH_FRIEND_THRESHOLD > friend->trails_count) &&
2403 (0 == GNUNET_TIME_absolute_get_remaining (friend->congestion_timestamp).rel_value_us))
2409 } while (j != index);
2411 GNUNET_CONTAINER_multipeermap_iterator_destroy (iter);
2417 * Compute 64 bit value of finger_identity corresponding to a finger index using
2420 * n.finger[i] = n + pow (2,i),
2422 * n.finger[i] = n - 1, where
2425 * n.finger[i] = 64 bit finger value
2426 * @param finger_index Index corresponding to which we calculate 64 bit value.
2427 * @return 64 bit value.
2430 compute_finger_identity_value (unsigned int finger_index)
2434 memcpy (&my_id64, &my_identity, sizeof (uint64_t));
2435 my_id64 = GNUNET_ntohll (my_id64);
2437 /* Are we looking for immediate predecessor? */
2438 if (PREDECESSOR_FINGER_ID == finger_index)
2439 return (my_id64 -1);
2441 return (my_id64 + (unsigned long) pow (2, finger_index));
2446 * Choose a random friend. Start looking for the trail to reach to
2447 * finger identity corresponding to current_search_finger_index through
2448 * this random friend.
2450 * @param cls closure for this task
2451 * @param tc the context under which the task is running
2454 send_find_finger_trail_message (void *cls,
2455 const struct GNUNET_SCHEDULER_TaskContext *tc)
2457 struct FriendInfo *target_friend;
2458 struct GNUNET_TIME_Relative next_send_time;
2459 struct GNUNET_HashCode trail_id;
2460 unsigned int is_predecessor;
2461 uint64_t finger_id_value;
2463 /* Schedule another send_find_finger_trail_message task. */
2464 next_send_time.rel_value_us =
2465 DHT_FIND_FINGER_TRAIL_INTERVAL.rel_value_us +
2466 GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK,
2467 DHT_FIND_FINGER_TRAIL_INTERVAL.rel_value_us);
2468 find_finger_trail_task =
2469 GNUNET_SCHEDULER_add_delayed (next_send_time, &send_find_finger_trail_message,
2472 /* No space in my routing table. (Source and destination peers also store entries
2473 * in their routing table). */
2474 if (GNUNET_YES == GDS_ROUTING_threshold_reached())
2477 target_friend = select_random_friend ();
2478 if (NULL == target_friend)
2483 finger_id_value = compute_finger_identity_value (current_search_finger_index);
2484 if (PREDECESSOR_FINGER_ID == current_search_finger_index)
2489 /* Generate a unique trail id for trail we are trying to setup. */
2490 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_STRONG,
2491 &trail_id, sizeof (trail_id));
2492 GDS_NEIGHBOURS_send_trail_setup (my_identity, finger_id_value,
2493 target_friend->id, target_friend, 0, NULL,
2494 is_predecessor, trail_id, NULL);
2499 * In case there are already maximum number of possible trails to reach to a
2500 * finger, then check if the new trail's length is lesser than any of the
2502 * If yes then replace that old trail by new trail.
2504 * Note: Here we are taking length as a parameter to choose the best possible
2505 * trail, but there could be other parameters also like:
2506 * 1. duration of existence of a trail - older the better.
2507 * 2. if the new trail is completely disjoint than the
2508 * other trails, then may be choosing it is better.
2510 * @param existing_finger
2511 * @param new_finger_trail
2512 * @param new_finger_trail_length
2513 * @param new_finger_trail_id
2516 select_and_replace_trail (struct FingerInfo *existing_finger,
2517 const struct GNUNET_PeerIdentity *new_trail,
2518 unsigned int new_trail_length,
2519 struct GNUNET_HashCode new_trail_id)
2521 struct Trail *trail_list_iterator;
2522 unsigned int largest_trail_length;
2523 unsigned int largest_trail_index;
2524 struct Trail_Element *trail_element;
2527 largest_trail_length = new_trail_length;
2528 largest_trail_index = MAXIMUM_TRAILS_PER_FINGER + 1;
2530 GNUNET_assert (MAXIMUM_TRAILS_PER_FINGER == existing_finger->trails_count);
2532 for (i = 0; i < existing_finger->trails_count; i++)
2534 trail_list_iterator = &existing_finger->trail_list[i];
2535 if (trail_list_iterator->trail_length > largest_trail_length)
2537 largest_trail_length = trail_list_iterator->trail_length;
2538 largest_trail_index = i;
2542 /* New trail is not better than existing ones. Send trail teardown. */
2543 if (largest_trail_index == (MAXIMUM_TRAILS_PER_FINGER + 1))
2545 struct GNUNET_PeerIdentity next_hop;
2547 memcpy (&next_hop, &new_trail[0], sizeof(struct GNUNET_PeerIdentity));
2548 GDS_ROUTING_remove_trail (new_trail_id);
2549 GDS_NEIGHBOURS_send_trail_teardown (new_trail_id,
2550 GDS_ROUTING_SRC_TO_DEST,
2555 /* Send trail teardown message across the replaced trail. */
2556 struct Trail *replace_trail = &existing_finger->trail_list[largest_trail_index];
2557 GDS_ROUTING_remove_trail (replace_trail->trail_id);
2558 GDS_NEIGHBOURS_send_trail_teardown (replace_trail->trail_id,
2559 GDS_ROUTING_SRC_TO_DEST,
2560 &replace_trail->trail_head->peer);
2561 /* Free the trail. */
2562 while (NULL != (trail_element = replace_trail->trail_head))
2564 GNUNET_CONTAINER_DLL_remove (replace_trail->trail_head,
2565 replace_trail->trail_tail, trail_element);
2566 GNUNET_free_non_null (trail_element);
2569 /* Add new trial at that location. */
2570 replace_trail->is_present = GNUNET_YES;
2571 replace_trail->trail_length = new_trail_length;
2572 replace_trail->trail_id = new_trail_id;
2573 //FIXME: Do we need to add pointers for head and tail.
2575 while (i < new_trail_length)
2577 struct Trail_Element *element = GNUNET_new (struct Trail_Element);
2578 element->peer = new_trail[i];
2580 GNUNET_CONTAINER_DLL_insert_tail (replace_trail->trail_head,
2581 replace_trail->trail_tail,
2588 * Check if the new trail to reach to finger is unique or do we already have
2589 * such a trail present for finger.
2590 * @param existing_finger Finger identity
2591 * @param new_trail New trail to reach @a existing_finger
2592 * @param trail_length Total number of peers in new_trail.
2593 * @return #GNUNET_YES if the new trail is unique
2594 * #GNUNET_NO if same trail is already present.
2597 is_new_trail_unique (struct FingerInfo *existing_finger,
2598 const struct GNUNET_PeerIdentity *new_trail,
2599 unsigned int trail_length)
2601 struct Trail *trail_list_iterator;
2602 struct Trail_Element *trail_element;
2605 int trail_unique = GNUNET_NO;
2607 GNUNET_assert (existing_finger->trails_count > 0);
2609 /* Iterate over list of trails. */
2610 for (i = 0; i < existing_finger->trails_count; i++)
2612 trail_list_iterator = &existing_finger->trail_list[i];
2613 GNUNET_assert (GNUNET_YES == trail_list_iterator->is_present);
2615 /* New trail and existing trail length are not same. */
2616 if (trail_list_iterator->trail_length != trail_length)
2618 trail_unique = GNUNET_YES;
2622 trail_element = trail_list_iterator->trail_head;
2623 for (j = 0; j < trail_list_iterator->trail_length; j++)
2625 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&new_trail[j],
2626 &trail_element->peer))
2628 trail_unique = GNUNET_YES;
2631 trail_element = trail_element->next;
2634 trail_unique = GNUNET_NO;
2637 return trail_unique;
2642 * Add a new trail to existing finger. This function is called only when finger
2643 * is not my own identity or a friend.
2644 * @param existing_finger Finger
2645 * @param new_finger_trail New trail from me to finger, NOT including endpoints
2646 * @param new_finger_trail_length Total number of peers in @a new_finger_trail
2647 * @param new_finger_trail_id Unique identifier of the trail.
2650 add_new_trail (struct FingerInfo *existing_finger,
2651 const struct GNUNET_PeerIdentity *new_trail,
2652 unsigned int new_trail_length,
2653 struct GNUNET_HashCode new_trail_id)
2655 struct Trail *trail_list_iterator;
2656 struct FriendInfo *first_friend;
2659 if (GNUNET_NO == is_new_trail_unique (existing_finger, new_trail,
2665 trail_list_iterator = &existing_finger->trail_list[existing_finger->trails_count];
2666 GNUNET_assert (GNUNET_NO == trail_list_iterator->is_present);
2667 trail_list_iterator->trail_id = new_trail_id;
2668 trail_list_iterator->trail_length = new_trail_length;
2669 existing_finger->trails_count++;
2670 trail_list_iterator->is_present = GNUNET_YES;
2672 /* If finger is a friend then we never call this function. */
2673 GNUNET_assert (new_trail_length > 0);
2675 first_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2677 first_friend->trails_count++;
2679 for (i = 0; i < new_trail_length; i++)
2681 struct Trail_Element *element;
2682 element = GNUNET_new (struct Trail_Element);
2684 element->peer = new_trail[i];
2685 GNUNET_CONTAINER_DLL_insert_tail (trail_list_iterator->trail_head,
2686 trail_list_iterator->trail_tail,
2689 /* Do we need to add trail head and trail tail in the trail list itearator.*/
2695 * FIXME Check if this function is called for opposite direction if yes then
2696 * take it as parameter.
2697 * Get the next hop to send trail teardown message from routing table and
2698 * then delete the entry from routing table. Send trail teardown message for a
2699 * specific trail of a finger.
2700 * @param finger Finger whose trail is to be removed.
2701 * @param trail List of peers in trail from me to a finger, NOT including
2705 send_trail_teardown (struct FingerInfo *finger,
2706 struct Trail *trail)
2708 struct FriendInfo *friend;
2709 struct GNUNET_PeerIdentity *next_hop;
2711 GNUNET_assert (NULL !=
2712 (next_hop = GDS_ROUTING_get_next_hop (trail->trail_id,
2713 GDS_ROUTING_SRC_TO_DEST)));
2714 if (trail->trail_length > 0)
2715 GNUNET_assert (NULL != (friend =
2716 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2717 &trail->trail_head->peer)));
2719 GNUNET_assert (NULL != (friend =
2720 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2721 &finger->finger_identity)));
2723 GNUNET_assert (0 == GNUNET_CRYPTO_cmp_peer_identity (next_hop, &friend->id));
2724 GDS_ROUTING_remove_trail (trail->trail_id);
2725 friend->trails_count--;
2726 GDS_NEIGHBOURS_send_trail_teardown (trail->trail_id,
2727 GDS_ROUTING_SRC_TO_DEST,
2728 &trail->trail_head->peer);
2733 * Send trail teardown message across all the trails to reach to finger.
2734 * @param finger Finger whose all the trail should be freed.
2737 send_all_finger_trails_teardown (struct FingerInfo *finger)
2739 struct Trail *trail;
2742 for (i = 0; i < finger->trails_count; i++)
2744 trail = &finger->trail_list[i];
2745 GNUNET_assert (trail->is_present == GNUNET_YES);
2746 send_trail_teardown (finger, trail);
2752 * Free a specific trail
2753 * @param trail List of peers to be freed.
2756 free_trail (struct Trail *trail)
2758 struct Trail_Element *trail_element;
2760 while (NULL != (trail_element = trail->trail_head))
2762 GNUNET_CONTAINER_DLL_remove (trail->trail_head,
2765 GNUNET_free_non_null (trail_element);
2767 trail->trail_head = NULL;
2768 trail->trail_tail = NULL;
2773 * Free finger and its trail.
2774 * @param finger Finger to be freed.
2777 free_finger (struct FingerInfo *finger, unsigned int finger_table_index)
2779 struct Trail *trail;
2782 /* Free all the trails to reach to finger */
2783 for (i = 0; i < finger->trails_count; i++)
2785 trail = &finger->trail_list[i];
2786 //FIXME: Check if there are any missing entry in this list because of
2787 // how we insert. If not then no need of this check.
2788 if (GNUNET_NO == trail->is_present)
2791 if (trail->trail_length > 0)
2794 trail->is_present = GNUNET_NO;
2798 finger->is_present = GNUNET_NO;
2799 memset ((void *)&finger_table[finger_table_index], 0, sizeof (finger_table[finger_table_index]));
2804 * FIXME: ensure that you are not adding any trail to reach to a friend which
2805 * is a finger. Also decide on should you increment trails count of a friend
2806 * which is also a finger.
2807 * Add a new entry in finger table at finger_table_index.
2808 * In case finger identity is me or a friend, then don't add a trail. NOTE
2809 * trail length to reach to a finger can be 0 only if the finger is a friend
2811 * In case a finger is a friend, then increment the trails count of the friend.
2812 * @param finger_identity Peer Identity of new finger
2813 * @param finger_trail Trail to reach from me to finger (excluding both end points).
2814 * @param finger_trail_length Total number of peers in @a finger_trail.
2815 * @param trail_id Unique identifier of the trail.
2816 * @param finger_table_index Index in finger table.
2819 add_new_finger (struct GNUNET_PeerIdentity finger_identity,
2820 const struct GNUNET_PeerIdentity *finger_trail,
2821 unsigned int finger_trail_length,
2822 struct GNUNET_HashCode trail_id,
2823 unsigned int finger_table_index)
2825 struct FingerInfo *new_entry;
2826 struct FriendInfo *first_trail_hop;
2827 struct Trail *trail;
2830 new_entry = GNUNET_new (struct FingerInfo);
2831 new_entry->finger_identity = finger_identity;
2832 new_entry->finger_table_index = finger_table_index;
2833 new_entry->is_present = GNUNET_YES;
2835 /* If the new entry is my own identity. */
2836 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &finger_identity))
2838 new_entry->trails_count = 0;
2839 finger_table[finger_table_index] = *new_entry;
2843 /* If finger is a friend, then we don't actually have a trail.
2844 * Just a trail id */
2845 if (NULL != GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2848 new_entry->trail_list[0].trail_id = trail_id;
2849 new_entry->trails_count = 1;
2850 new_entry->trail_list[0].is_present = GNUNET_YES;
2851 new_entry->trail_list[0].trail_length = 0;
2852 new_entry->trail_list[0].trail_head = NULL;
2853 new_entry->trail_list[0].trail_tail = NULL;
2854 finger_table[finger_table_index] = *new_entry;
2855 GNUNET_assert (NULL !=
2857 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2858 &finger_identity)));
2859 first_trail_hop->trails_count++;
2863 /* finger trail length can be 0 only in case if finger is my identity or
2864 finger is friend. We should never reach here. */
2865 GNUNET_assert (finger_trail_length > 0);
2867 GNUNET_assert (NULL !=
2869 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2870 &finger_trail[0])));
2871 new_entry->trails_count = 1;
2872 first_trail_hop->trails_count++;
2874 /* Copy the finger trail into trail. */
2875 trail = GNUNET_new (struct Trail);
2876 while (i < finger_trail_length)
2878 struct Trail_Element *element = GNUNET_new (struct Trail_Element);
2880 element->next = NULL;
2881 element->prev = NULL;
2882 element->peer = finger_trail[i];
2883 GNUNET_CONTAINER_DLL_insert_tail (trail->trail_head,
2889 /* Add trail to trail list. */
2890 new_entry->trail_list[0].trail_head = trail->trail_head;
2891 new_entry->trail_list[0].trail_tail = trail->trail_tail;
2892 new_entry->trail_list[0].trail_length = finger_trail_length;
2893 new_entry->trail_list[0].trail_id = trail_id;
2894 new_entry->trail_list[0].is_present = GNUNET_YES;
2895 finger_table[finger_table_index] = *new_entry;
2896 GNUNET_free (new_entry);
2897 GNUNET_free (trail);
2903 * Scan the trail to check if there is any other friend in the trail other than
2904 * first hop. If yes then shortcut the trail, send trail compression message to
2905 * peers which are no longer part of trail and send back the updated trail
2906 * and trail_length to calling function.
2907 * @param finger_identity Finger whose trail we will scan.
2908 * @param finger_trail [in, out] Trail to reach from source to finger,
2909 * @param finger_trail_length Total number of peers in original finger_trail.
2910 * @param finger_trail_id Unique identifier of the finger trail.
2911 * @return updated trail length in case we shortcut the trail, else original
2914 static struct GNUNET_PeerIdentity *
2915 scan_and_compress_trail (struct GNUNET_PeerIdentity finger_identity,
2916 const struct GNUNET_PeerIdentity *trail,
2917 unsigned int trail_length,
2918 struct GNUNET_HashCode trail_id,
2919 int *new_trail_length)
2921 struct FriendInfo *target_friend;
2922 struct GNUNET_PeerIdentity *new_trail;
2925 /* If I am my own finger identity, then we set trail_length = 0.
2926 Note: Here we don't send trail compression message, as no peer in its
2927 trail added an entry in its routing table.*/
2928 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &finger_identity))
2930 *new_trail_length = 0;
2934 /* If finger identity is a friend. */
2935 if (NULL != GNUNET_CONTAINER_multipeermap_get (friend_peermap, &finger_identity))
2937 *new_trail_length = 0;
2939 /* If there is trail to reach this finger/friend */
2940 if (trail_length > 0)
2942 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2944 /* FIXME: In case its finger == friend, then may be we send a trail
2945 teardown message as it does not make any sense to have any routing e
2946 entry in your own routing table.*/
2947 GDS_NEIGHBOURS_send_trail_compression (my_identity,
2948 trail_id, finger_identity,
2954 /* For other cases, when its neither a friend nor my own identity.*/
2955 for (i = trail_length - 1; i > 0; i--)
2957 /* If the element at this index in trail is a friend. */
2958 if (NULL != GNUNET_CONTAINER_multipeermap_get (friend_peermap, &trail[i]))
2960 struct FriendInfo *target_friend;
2963 GNUNET_assert (NULL !=
2965 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2967 GDS_NEIGHBOURS_send_trail_compression (my_identity,
2972 /* Copy the trail from index i to index (trail_length -1) into a new trail
2973 * and update new trail length */
2974 new_trail = GNUNET_malloc (sizeof (struct GNUNET_PeerIdentity) * i);
2975 while (i < trail_length)
2977 memcpy (&new_trail[j], &trail[i], sizeof(struct GNUNET_PeerIdentity));
2981 *new_trail_length = j+1;
2986 /* If we did not compress the trail, return the original trail back.*/
2987 new_trail = GNUNET_malloc (sizeof (struct GNUNET_PeerIdentity) * trail_length);
2988 *new_trail_length = trail_length;
2989 memcpy (new_trail, trail, trail_length * sizeof (struct GNUNET_PeerIdentity));
2995 * Send verify successor message to your current successor over the shortest
2997 * @param successor Current successor.
3000 send_verify_successor_message (struct FingerInfo *successor)
3003 * FIXME: should we send a verify successor message across all the trails
3004 * in case we send through all friends. It complicates the logic, don't
3005 * do it at the moment. Write it as optimization and do it later.
3006 * 1. Here we can have 3 types of fingers
3007 * --> my own identity
3008 * Assumption that the calling function will not send request for
3009 * such successor. Move the logic here.
3010 * --> friend is a finger
3011 * Need to verify if we keep the trails count for a friend. In case of
3012 * friend there is no trail to reach to that friend, so
3013 * 1. no entry in routing table
3015 * 3. no trails count
3016 * 4. but do we increment the count of trails through the friend?
3017 * Trails count is used only to keep a limit on number of trails
3018 * that a friend should be part of. No need to increment the trails
3019 * count for a friend which is a finegr also. so, if finger = friend
3020 * then don't increment the trails count. But if the same friend
3021 * is the first friend to reach to some other finger then increment
3022 * the trails count. Not sure if this design is correct need to verify
3026 struct FriendInfo *target_friend;
3027 struct GNUNET_HashCode trail_id;
3030 for (i = 0; i < successor->trails_count; i++)
3032 struct Trail *trail;
3033 struct Trail_Element *element;
3034 unsigned int trail_length;
3037 trail = &successor->trail_list[i];
3039 /* No trail stored at this index. */
3040 if (GNUNET_YES == trail->is_present)
3043 trail_id = trail->trail_id;
3044 trail_length = trail->trail_length;
3046 /* Copy the trail into peer list. */
3047 element = trail->trail_head;
3048 struct GNUNET_PeerIdentity peer_list[trail_length];
3049 while (j < trail_length)
3051 peer_list[j] = element->peer;
3052 element = element->next;
3056 if (trail_length > 0)
3057 GNUNET_assert (NULL != (target_friend =
3058 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
3061 GNUNET_assert (NULL != (target_friend =
3062 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
3063 &successor->finger_identity)));
3064 GDS_NEIGHBOURS_send_verify_successor_message (my_identity,
3065 successor->finger_identity,
3066 trail_id, peer_list, trail_length,
3074 * Update the current search finger index.
3077 update_current_search_finger_index (struct GNUNET_PeerIdentity finger_identity,
3078 unsigned int finger_table_index)
3080 struct FingerInfo *successor;
3082 if (finger_table_index != current_search_finger_index)
3085 successor = &finger_table[0];
3086 if (GNUNET_NO == successor->is_present)
3089 /* We were looking for immediate successor. */
3090 if (0 == current_search_finger_index)
3092 /* Start looking for immediate predecessor. */
3093 current_search_finger_index = PREDECESSOR_FINGER_ID;
3095 /* If I am not my own successor, then send a verify successor message. */
3096 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &finger_identity))
3098 send_verify_successor_message (successor);
3103 current_search_finger_index = current_search_finger_index - 1;
3109 * Calculate finger_table_index from initial 64 bit finger identity value that
3110 * we send in trail setup message.
3111 * @param ultimate_destination_finger_value Value that we calculated from our
3112 * identity and finger_table_index.
3113 * @param is_predecessor Is the entry for predecessor or not?
3114 * @return finger_table_index Value between 0 <= finger_table_index <= 64
3115 * finger_table_index > PREDECESSOR_FINGER_ID ,
3116 * if no valid finger_table_index is found.
3119 get_finger_table_index (uint64_t ultimate_destination_finger_value,
3120 unsigned int is_predecessor)
3124 unsigned int finger_table_index;
3126 memcpy (&my_id64, &my_identity, sizeof (uint64_t));
3127 my_id64 = GNUNET_ntohll (my_id64);
3129 /* Is this a predecessor finger? */
3130 if (1 == is_predecessor)
3132 diff = my_id64 - ultimate_destination_finger_value;
3134 finger_table_index = PREDECESSOR_FINGER_ID;
3136 finger_table_index = PREDECESSOR_FINGER_ID + 1; //error value
3141 diff = ultimate_destination_finger_value - my_id64;
3142 finger_table_index = (log10 (diff))/(log10 (2));
3145 return finger_table_index;
3150 * Remove finger and its associated data structures from finger table.
3151 * @param finger Finger to be removed.
3154 remove_existing_finger (struct FingerInfo *existing_finger, unsigned int finger_table_index)
3156 struct FingerInfo *finger;
3158 finger = &finger_table[finger_table_index];
3159 GNUNET_assert (GNUNET_YES == finger->is_present);
3161 /* If I am my own finger, then we have no trails. */
3162 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&finger->finger_identity,
3165 finger->is_present = GNUNET_NO;
3166 memset ((void *)&finger_table[finger_table_index], 0, sizeof (finger_table[finger_table_index]));
3170 /* For all other fingers, send trail teardown across all the trails to reach
3171 finger, and free the finger. */
3172 send_all_finger_trails_teardown (finger);
3173 free_finger (finger, finger_table_index);
3179 * This is a test function to print all the entries of friend table.
3182 test_friend_peermap_print ()
3184 struct FriendInfo *friend;
3185 struct GNUNET_CONTAINER_MultiPeerMapIterator *friend_iter;
3186 struct GNUNET_PeerIdentity print_peer;
3187 struct GNUNET_PeerIdentity key_ret;
3190 friend_iter = GNUNET_CONTAINER_multipeermap_iterator_create (friend_peermap);
3192 for (i = 0; i < GNUNET_CONTAINER_multipeermap_size (friend_peermap); i++)
3194 if(GNUNET_YES == GNUNET_CONTAINER_multipeermap_iterator_next (friend_iter,
3196 (const void **)&friend))
3198 memcpy (&print_peer, &key_ret, sizeof (struct GNUNET_PeerIdentity));
3199 FPRINTF (stderr,_("\nSUPU %s, %s, %d, friend = %s, friend->trails_count = %d"),
3200 __FILE__, __func__,__LINE__, GNUNET_i2s(&print_peer), friend->trails_count);
3207 * This is a test function, to print all the entries of finger table.
3210 test_finger_table_print()
3212 struct FingerInfo *finger;
3213 struct GNUNET_PeerIdentity print_peer;
3214 struct Trail *trail;
3219 FPRINTF (stderr,_("\nSUPU************ FINGER_TABLE"));
3220 for (i = 0; i < MAX_FINGERS; i++)
3222 finger = &finger_table[i];
3224 if (GNUNET_NO == finger->is_present)
3227 print_peer = finger->finger_identity;
3228 FPRINTF (stderr,_("\nSUPU %s, %s, %d, finger_table[%d] = %s, trails_count = %d"),
3229 __FILE__, __func__,__LINE__,i,GNUNET_i2s (&print_peer), finger->trails_count);
3232 for (j = 0; j < finger->trails_count; j++)
3234 trail = &finger->trail_list[j];
3235 FPRINTF (stderr,_("\nSUPU %s, %s, %d, trail_id[%d]=%s"),__FILE__, __func__,__LINE__,j, GNUNET_h2s(&trail->trail_id));
3236 struct Trail_Element *element;
3237 element = trail->trail_head;
3238 for (k = 0; k < trail->trail_length; k++)
3240 print_peer = element->peer;
3241 FPRINTF (stderr,_("\nSUPU %s, %s, %d,trail[%d] = %s "),__FILE__, __func__,__LINE__,k, GNUNET_i2s(&print_peer));
3242 element = element->next;
3250 * Check if there is already an entry in finger_table at finger_table_index.
3251 * We get the finger_table_index from 64bit finger value we got from the network.
3252 * -- If yes, then select the closest finger.
3253 * -- If new and existing finger are same, then check if you can store more
3255 * -- If yes then add trail, else keep the best trails to reach to the
3257 * -- If the new finger is closest, remove the existing entry, send trail
3258 * teardown message across all the trails to reach the existing entry.
3259 * Add the new finger.
3260 * -- If new and existing finger are different, and existing finger is closest
3262 * -- Update current_search_finger_index.
3263 * @param finger_identity Peer Identity of new finger
3264 * @param finger_trail Trail to reach the new finger
3265 * @param finger_trail_length Total number of peers in @a new_finger_trail.
3266 * @param is_predecessor Is this entry for predecessor in finger_table?
3267 * @param finger_value 64 bit value of finger identity that we got from network.
3268 * @param finger_trail_id Unique identifier of @finger_trail.
3271 finger_table_add (struct GNUNET_PeerIdentity finger_identity,
3272 const struct GNUNET_PeerIdentity *finger_trail,
3273 unsigned int finger_trail_length,
3274 unsigned int is_predecessor,
3275 uint64_t finger_value,
3276 struct GNUNET_HashCode finger_trail_id)
3278 struct FingerInfo *existing_finger;
3279 struct GNUNET_PeerIdentity *closest_peer;
3280 struct GNUNET_PeerIdentity *updated_trail;
3281 struct FingerInfo *successor;
3282 int updated_finger_trail_length;
3283 unsigned int finger_table_index;
3286 test_friend_peermap_print();
3287 test_finger_table_print();
3290 /* Get the finger_table_index corresponding to finger_value we got from network.*/
3291 finger_table_index = get_finger_table_index (finger_value, is_predecessor);
3293 /* Invalid finger_table_index. */
3294 if ((finger_table_index > PREDECESSOR_FINGER_ID))
3296 GNUNET_break_op (0);
3300 /* If the new entry for any finger table index other than successor or predecessor
3301 * is same as successor then don't add it in finger table,
3302 * reset the current search finger index and exit. */
3303 if ((0 != finger_table_index) &&
3304 (PREDECESSOR_FINGER_ID != finger_table_index) &&
3305 (finger_table_index == current_search_finger_index)) //FIXME; why do I check this cond?
3307 successor = &finger_table[0];
3308 GNUNET_assert (GNUNET_YES == successor->is_present);
3309 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&finger_identity,
3310 &successor->finger_identity))
3312 current_search_finger_index = 0;
3317 existing_finger = &finger_table[finger_table_index];
3319 /* Shorten the trail if possible. */
3320 updated_finger_trail_length = finger_trail_length;
3322 scan_and_compress_trail (finger_identity, finger_trail,
3323 finger_trail_length, finger_trail_id,
3324 &updated_finger_trail_length);
3326 /* No entry present in finger_table for given finger map index. */
3327 if (GNUNET_NO == existing_finger->is_present)
3329 add_new_finger (finger_identity, updated_trail,
3330 updated_finger_trail_length,
3331 finger_trail_id, finger_table_index);
3332 update_current_search_finger_index (finger_identity, finger_table_index);
3333 GNUNET_free_non_null (updated_trail);
3338 /* If existing entry and finger identity are not same. */
3339 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&(existing_finger->finger_identity),
3342 closest_peer = select_closest_peer (&existing_finger->finger_identity,
3347 /* If the new finger is the closest peer. */
3348 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&finger_identity, closest_peer))
3350 remove_existing_finger (existing_finger, finger_table_index);
3351 add_new_finger (finger_identity, updated_trail, updated_finger_trail_length,
3352 finger_trail_id, finger_table_index);
3357 /* If both new and existing entry are same as my_identity, then do nothing. */
3358 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&(existing_finger->finger_identity),
3361 GNUNET_free_non_null (updated_trail);
3364 /* If the existing finger is not a friend. */
3366 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
3367 &existing_finger->finger_identity))
3369 /* If there is space to store more trails. */
3370 if (existing_finger->trails_count < MAXIMUM_TRAILS_PER_FINGER)
3371 add_new_trail (existing_finger, updated_trail,
3372 finger_trail_length, finger_trail_id);
3374 select_and_replace_trail (existing_finger, updated_trail,
3375 finger_trail_length, finger_trail_id);
3378 update_current_search_finger_index (finger_identity, finger_table_index);
3379 GNUNET_free_non_null (updated_trail);
3385 * Core handler for P2P put messages.
3386 * @param cls closure
3387 * @param peer sender of the request
3388 * @param message message
3389 * @return #GNUNET_OK to keep the connection open,
3390 * #GNUNET_SYSERR to close it (signal serious error)
3393 handle_dht_p2p_put (void *cls, const struct GNUNET_PeerIdentity *peer,
3394 const struct GNUNET_MessageHeader *message)
3396 struct PeerPutMessage *put;
3397 struct GNUNET_PeerIdentity *put_path;
3398 struct GNUNET_HashCode test_key;
3399 enum GNUNET_DHT_RouteOption options;
3400 struct GNUNET_PeerIdentity best_known_dest;
3401 struct GNUNET_HashCode intermediate_trail_id;
3402 struct GNUNET_PeerIdentity *next_hop;
3406 size_t payload_size;
3409 msize = ntohs (message->size);
3410 if (msize < sizeof (struct PeerPutMessage))
3412 GNUNET_break_op (0);
3416 put = (struct PeerPutMessage *) message;
3417 putlen = ntohl (put->put_path_length);
3420 sizeof (struct PeerPutMessage) +
3421 putlen * sizeof (struct GNUNET_PeerIdentity)) ||
3423 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)))
3425 GNUNET_break_op (0);
3429 best_known_dest = put->best_known_destination;
3430 put_path = (struct GNUNET_PeerIdentity *) &put[1];
3431 payload = &put_path[putlen];
3432 options = ntohl (put->options);
3433 intermediate_trail_id = put->intermediate_trail_id;
3435 payload_size = msize - (sizeof (struct PeerPutMessage) +
3436 putlen * sizeof (struct GNUNET_PeerIdentity));
3438 switch (GNUNET_BLOCK_get_key (GDS_block_context, ntohl (put->block_type),
3439 payload, payload_size, &test_key))
3442 if (0 != memcmp (&test_key, &put->key, sizeof (struct GNUNET_HashCode)))
3444 char *put_s = GNUNET_strdup (GNUNET_h2s_full (&put->key));
3445 GNUNET_break_op (0);
3446 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3447 "PUT with key `%s' for block with key %s\n",
3448 put_s, GNUNET_h2s_full (&test_key));
3449 GNUNET_free (put_s);
3454 GNUNET_break_op (0);
3457 /* cannot verify, good luck */
3461 if (ntohl (put->block_type) == GNUNET_BLOCK_TYPE_REGEX) /* FIXME: do for all tpyes */
3463 switch (GNUNET_BLOCK_evaluate (GDS_block_context,
3464 ntohl (put->block_type),
3466 NULL, 0, /* bloom filer */
3467 NULL, 0, /* xquery */
3468 payload, payload_size))
3470 case GNUNET_BLOCK_EVALUATION_OK_MORE:
3471 case GNUNET_BLOCK_EVALUATION_OK_LAST:
3474 case GNUNET_BLOCK_EVALUATION_OK_DUPLICATE:
3475 case GNUNET_BLOCK_EVALUATION_RESULT_INVALID:
3476 case GNUNET_BLOCK_EVALUATION_RESULT_IRRELEVANT:
3477 case GNUNET_BLOCK_EVALUATION_REQUEST_VALID:
3478 case GNUNET_BLOCK_EVALUATION_REQUEST_INVALID:
3479 case GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED:
3481 GNUNET_break_op (0);
3486 /* extend 'put path' by sender */
3487 struct GNUNET_PeerIdentity pp[putlen + 1];
3488 if (0 != (options & GNUNET_DHT_RO_RECORD_ROUTE))
3490 memcpy (pp, put_path, putlen * sizeof (struct GNUNET_PeerIdentity));
3497 memcpy (&key_value, &(put->key), sizeof (uint64_t));
3498 if (0 != (GNUNET_CRYPTO_cmp_peer_identity (&best_known_dest, &my_identity)))
3500 next_hop = GDS_ROUTING_get_next_hop (intermediate_trail_id,
3501 GDS_ROUTING_SRC_TO_DEST);
3505 next_hop = find_successor (key_value, &best_known_dest,
3506 &intermediate_trail_id, GDS_FINGER_TYPE_NON_PREDECESSOR);
3509 if (NULL == next_hop)
3511 GNUNET_STATISTICS_update (GDS_stats,
3512 gettext_noop ("# Next hop to forward the packet not found "
3513 "trail setup request, packet dropped."),
3515 return GNUNET_SYSERR;
3518 GDS_CLIENTS_process_put (options,
3519 ntohl (put->block_type),
3520 ntohl (put->hop_count),
3521 ntohl (put->desired_replication_level),
3523 GNUNET_TIME_absolute_ntoh (put->expiration_time),
3528 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &best_known_dest)) /* I am the final destination */
3530 GDS_DATACACHE_handle_put (GNUNET_TIME_absolute_ntoh (put->expiration_time),
3531 &(put->key),putlen, pp, ntohl (put->block_type),
3532 payload_size, payload);
3533 GNUNET_free_non_null (next_hop);
3538 GDS_NEIGHBOURS_send_put (&put->key,
3539 ntohl (put->block_type),ntohl (put->options),
3540 ntohl (put->desired_replication_level),
3541 &best_known_dest, &intermediate_trail_id, next_hop,
3542 ntohl (put->hop_count), putlen, pp,
3543 GNUNET_TIME_absolute_ntoh (put->expiration_time),
3544 payload, payload_size);
3548 return GNUNET_SYSERR;
3553 * Core handler for p2p get requests.
3555 * @param cls closure
3556 * @param peer sender of the request
3557 * @param message message
3558 * @return #GNUNET_OK to keep the connection open,
3559 * #GNUNET_SYSERR to close it (signal serious error)
3562 handle_dht_p2p_get (void *cls, const struct GNUNET_PeerIdentity *peer,
3563 const struct GNUNET_MessageHeader *message)
3565 const struct PeerGetMessage *get;
3566 const struct GNUNET_PeerIdentity *get_path;
3567 struct GNUNET_PeerIdentity best_known_dest;
3568 struct GNUNET_HashCode intermediate_trail_id;
3569 struct GNUNET_PeerIdentity *next_hop;
3570 uint32_t get_length;
3574 msize = ntohs (message->size);
3575 if (msize < sizeof (struct PeerGetMessage))
3577 GNUNET_break_op (0);
3581 get = (const struct PeerGetMessage *)message;
3582 get_length = ntohl (get->get_path_length);
3583 best_known_dest = get->best_known_destination;
3584 intermediate_trail_id = get->intermediate_trail_id;
3585 get_path = (const struct GNUNET_PeerIdentity *)&get[1];
3588 sizeof (struct PeerGetMessage) +
3589 get_length * sizeof (struct GNUNET_PeerIdentity)) ||
3591 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)))
3593 GNUNET_break_op (0);
3597 /* Add sender to get path */
3598 struct GNUNET_PeerIdentity gp[get_length + 1];
3600 memcpy (gp, get_path, get_length * sizeof (struct GNUNET_PeerIdentity));
3601 gp[get_length] = *peer;
3602 get_length = get_length + 1;
3604 memcpy (&key_value, &(get->key), sizeof (uint64_t));
3605 key_value = GNUNET_ntohll (key_value);
3607 /* I am not the final destination. I am part of trail to reach final dest. */
3608 if (0 != (GNUNET_CRYPTO_cmp_peer_identity (&best_known_dest, &my_identity)))
3610 next_hop = GDS_ROUTING_get_next_hop (intermediate_trail_id,
3611 GDS_ROUTING_SRC_TO_DEST);
3615 /* Get the next hop to pass the message to. */
3616 next_hop = find_successor (key_value, &best_known_dest,
3617 &intermediate_trail_id, GDS_FINGER_TYPE_NON_PREDECESSOR);
3620 if (NULL == next_hop)
3622 GNUNET_STATISTICS_update (GDS_stats,
3623 gettext_noop ("# Next hop to forward the packet not found "
3624 "trail setup request, packet dropped."),
3626 return GNUNET_SYSERR;
3628 GDS_CLIENTS_process_get (get->options, get->block_type,get->hop_count,
3629 get->desired_replication_level, get->get_path_length,
3631 /* I am the final destination. */
3632 if (0 == GNUNET_CRYPTO_cmp_peer_identity(&my_identity, &best_known_dest))
3634 struct GNUNET_PeerIdentity final_get_path[get_length+1];
3635 struct GNUNET_PeerIdentity next_hop;
3637 memcpy (final_get_path, gp, get_length * sizeof (struct GNUNET_PeerIdentity));
3638 memcpy (&final_get_path[get_length], &my_identity, sizeof (struct GNUNET_PeerIdentity));
3639 get_length = get_length + 1;
3641 /* Get the next hop to pass the get result message. */
3642 memcpy (&next_hop, &final_get_path[get_length-2], sizeof (struct GNUNET_PeerIdentity));
3643 GDS_DATACACHE_handle_get (&(get->key),(get->block_type), NULL, 0, NULL, 0,
3644 get_length, final_get_path, &next_hop, &my_identity);
3649 GDS_NEIGHBOURS_send_get (&(get->key), get->block_type, get->options,
3650 get->desired_replication_level, &best_known_dest,
3651 &intermediate_trail_id, next_hop, 0,
3654 GNUNET_free_non_null (next_hop);
3655 return GNUNET_SYSERR;
3660 * Core handler for get result
3661 * @param cls closure
3662 * @param peer sender of the request
3663 * @param message message
3664 * @return #GNUNET_OK to keep the connection open,
3665 * #GNUNET_SYSERR to close it (signal serious error)
3668 handle_dht_p2p_get_result (void *cls, const struct GNUNET_PeerIdentity *peer,
3669 const struct GNUNET_MessageHeader *message)
3671 const struct PeerGetResultMessage *get_result;
3672 const struct GNUNET_PeerIdentity *get_path;
3673 const struct GNUNET_PeerIdentity *put_path;
3674 const void *payload;
3675 size_t payload_size;
3677 unsigned int getlen;
3678 unsigned int putlen;
3679 int current_path_index;
3681 msize = ntohs (message->size);
3682 if (msize < sizeof (struct PeerGetResultMessage))
3684 GNUNET_break_op (0);
3688 get_result = (const struct PeerGetResultMessage *)message;
3689 getlen = ntohl (get_result->get_path_length);
3690 putlen = ntohl (get_result->put_path_length);
3693 sizeof (struct PeerGetResultMessage) +
3694 getlen * sizeof (struct GNUNET_PeerIdentity) +
3695 putlen * sizeof (struct GNUNET_PeerIdentity)) ||
3697 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity) ||
3699 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity))))
3701 GNUNET_break_op (0);
3705 put_path = (const struct GNUNET_PeerIdentity *) &get_result[1];
3706 get_path = &put_path[putlen];
3707 payload = (const void *) &get_path[getlen];
3708 payload_size = msize - (sizeof (struct PeerGetResultMessage) +
3709 (getlen + putlen) * sizeof (struct GNUNET_PeerIdentity));
3711 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &(get_path[0]))))
3713 GDS_CLIENTS_handle_reply (get_result->expiration_time, &(get_result->key),
3714 getlen, get_path, putlen,
3715 put_path, get_result->type, payload_size, payload);
3720 current_path_index = search_my_index (get_path, getlen);
3721 if (-1 == current_path_index )
3724 return GNUNET_SYSERR;
3726 GDS_NEIGHBOURS_send_get_result (&(get_result->key), get_result->type,
3727 &get_path[current_path_index - 1],
3728 &(get_result->querying_peer), putlen, put_path,
3729 getlen, get_path, get_result->expiration_time,
3730 payload, payload_size);
3733 return GNUNET_SYSERR;
3738 * Get the best known next destination (local_dest) among your fingers, friends
3739 * and my identity. In case I was part of trail to reach to some other destination
3740 * (current_dest), then compare current_dest and local_dest, and choose the
3742 * @param final_dest_finger_value Peer closest to this value will be
3743 * @a local_best_known_dest
3744 * @param local_best_known_dest[out] Updated to peer identity which is closest to
3745 * @a final_dest_finger_value.
3746 * @param new_intermediate_trail_id In case @a local_best_known_dest is a finger,
3747 * then the trail id to reach to the finger
3748 * @param is_predecessor Is source peer trying to setup trail to its predecessor
3750 * @param current_dest Peer which should get this message ultimately according
3751 * to the peer which sent me this message. It could be me
3752 * or some other peer. In case it is not me, then I am a part
3753 * of trail to reach to that peer.
3756 static struct GNUNET_PeerIdentity *
3757 get_local_best_known_next_hop (uint64_t final_dest_finger_value,
3758 struct GNUNET_PeerIdentity *local_best_known_dest,
3759 struct GNUNET_HashCode *new_intermediate_trail_id,
3760 struct GNUNET_HashCode intermediate_trail_id,
3761 unsigned int is_predecessor,
3762 struct GNUNET_PeerIdentity *current_dest)
3764 struct GNUNET_PeerIdentity *next_hop_to_local_best_known_dest;
3766 /* Choose a local best known hop among your fingers, friends and you. */
3767 next_hop_to_local_best_known_dest = find_successor (final_dest_finger_value,
3768 local_best_known_dest,
3769 new_intermediate_trail_id,
3772 /* Are we just a part of a trail towards a finger (current_destination)? */
3773 if (0 != (GNUNET_CRYPTO_cmp_peer_identity (&my_identity, current_dest)))
3775 struct GNUNET_PeerIdentity *closest_peer;
3777 /* Select best successor among one found locally and current_destination
3778 * that we got from network.*/
3779 closest_peer = select_closest_peer (local_best_known_dest,
3781 final_dest_finger_value,
3784 /* Is current dest (end point of the trail of which I am a part) closest_peer? */
3785 if (0 == GNUNET_CRYPTO_cmp_peer_identity (current_dest, closest_peer))
3787 struct GNUNET_PeerIdentity *next_hop;
3788 next_hop = GDS_ROUTING_get_next_hop (intermediate_trail_id,
3789 GDS_ROUTING_SRC_TO_DEST);
3790 /* FIXME: Here we found next_hop NULL from routing table, but we still
3791 * have a next_hop from find_successor should we not break and choose that
3793 if (NULL == next_hop)
3795 GNUNET_break_op (0);
3798 next_hop_to_local_best_known_dest = next_hop;
3799 local_best_known_dest = current_dest;
3800 *new_intermediate_trail_id = intermediate_trail_id;
3804 GNUNET_assert (NULL != next_hop_to_local_best_known_dest);
3805 return next_hop_to_local_best_known_dest;
3810 * Core handle for PeerTrailSetupMessage.
3811 * @param cls closure
3812 * @param message message
3813 * @param peer peer identity this notification is about
3814 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
3817 handle_dht_p2p_trail_setup (void *cls, const struct GNUNET_PeerIdentity *peer,
3818 const struct GNUNET_MessageHeader *message)
3820 const struct PeerTrailSetupMessage *trail_setup;
3821 const struct GNUNET_PeerIdentity *trail_peer_list;
3822 struct GNUNET_PeerIdentity *local_best_known_dest;
3823 struct GNUNET_PeerIdentity current_dest;
3824 struct GNUNET_PeerIdentity *next_hop_towards_local_best_known_dest;
3825 struct GNUNET_PeerIdentity next_peer;
3826 struct FriendInfo *target_friend;
3827 struct GNUNET_PeerIdentity source;
3828 uint64_t final_dest_finger_val;
3829 struct GNUNET_HashCode new_intermediate_trail_id;
3830 struct GNUNET_HashCode intermediate_trail_id;
3831 struct GNUNET_HashCode trail_id;
3832 unsigned int is_predecessor;
3833 uint32_t trail_length;
3836 msize = ntohs (message->size);
3837 if (msize < sizeof (struct PeerTrailSetupMessage))
3839 GNUNET_break_op (0);
3843 trail_setup = (const struct PeerTrailSetupMessage *) message;
3844 trail_length = (msize - sizeof (struct PeerTrailSetupMessage))/
3845 sizeof (struct GNUNET_PeerIdentity);
3846 if ((msize - sizeof (struct PeerTrailSetupMessage)) %
3847 sizeof (struct GNUNET_PeerIdentity) != 0)
3849 GNUNET_break_op (0);
3853 trail_peer_list = (const struct GNUNET_PeerIdentity *)&trail_setup[1];
3854 current_dest = trail_setup->best_known_destination;
3855 trail_id = trail_setup->trail_id;
3856 final_dest_finger_val =
3857 GNUNET_ntohll (trail_setup->final_destination_finger_value);
3858 source = trail_setup->source_peer;
3859 is_predecessor = ntohl (trail_setup->is_predecessor);
3860 intermediate_trail_id = trail_setup->intermediate_trail_id;
3862 /* Is my routing table full? */
3863 if (GNUNET_YES == GDS_ROUTING_threshold_reached())
3865 /* As my routing table is full, I can no longer handle any more trail
3867 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, peer);
3868 GDS_NEIGHBOURS_send_trail_rejection (source, final_dest_finger_val,
3869 my_identity, is_predecessor,
3870 trail_peer_list, trail_length,
3871 trail_id, target_friend,
3872 CONGESTION_TIMEOUT);
3876 local_best_known_dest = GNUNET_new (struct GNUNET_PeerIdentity);
3878 /* Get the next hop to forward the trail setup request. */
3879 next_hop_towards_local_best_known_dest =
3880 get_local_best_known_next_hop (final_dest_finger_val,
3881 local_best_known_dest,
3882 &new_intermediate_trail_id,
3883 intermediate_trail_id,
3887 /* Am I the final destination? */
3888 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (local_best_known_dest,
3891 /* If I was not the source of this message for which now I am destination */
3892 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&source, &my_identity))
3894 GDS_ROUTING_add (trail_id, *peer, my_identity);
3897 if (0 == trail_length)
3898 memcpy (&next_peer, &source, sizeof (struct GNUNET_PeerIdentity));
3900 memcpy (&next_peer, &trail_peer_list[trail_length-1], sizeof (struct GNUNET_PeerIdentity));
3902 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, &next_peer);
3903 GDS_NEIGHBOURS_send_trail_setup_result (source,
3905 target_friend, trail_length,
3907 final_dest_finger_val,
3908 is_predecessor, trail_id);
3912 /* Add yourself to list of peers. */
3913 struct GNUNET_PeerIdentity peer_list[trail_length + 1];
3915 memcpy (peer_list, trail_peer_list,
3916 trail_length * sizeof (struct GNUNET_PeerIdentity));
3917 peer_list[trail_length] = my_identity;
3919 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
3920 next_hop_towards_local_best_known_dest);
3921 GDS_NEIGHBOURS_send_trail_setup (source,
3922 final_dest_finger_val,
3923 *local_best_known_dest,
3924 target_friend, trail_length + 1, peer_list,
3925 is_predecessor, trail_id,
3926 &new_intermediate_trail_id);
3928 GNUNET_free (local_best_known_dest);
3929 GNUNET_free (next_hop_towards_local_best_known_dest);
3934 /* FIXME: here we are calculating my_index and comparing also in this function.
3935 And we are doing it again here in this function. Re factor the code. */
3937 * FIXME: Should we call this function everywhere in all the handle functions
3938 * where we have a trail to verify from or a trail id. something like
3939 * if prev hop is not same then drop the message.
3940 * Check if sender_peer and peer from which we should receive the message are
3941 * same or different.
3942 * @param trail_peer_list List of peers in trail
3943 * @param trail_length Total number of peers in @a trail_peer_list
3944 * @param sender_peer Peer from which we got the message.
3945 * @param finger_identity Finger to which trail is setup. It is not part of trail.
3946 * @return #GNUNET_YES if sender_peer and peer from which we should receive the
3947 * message are different.
3948 * #GNUNET_NO if sender_peer and peer from which we should receive the
3949 * message are different.
3952 is_sender_peer_correct (const struct GNUNET_PeerIdentity *trail_peer_list,
3953 unsigned int trail_length,
3954 const struct GNUNET_PeerIdentity *sender_peer,
3955 struct GNUNET_PeerIdentity finger_identity,
3956 struct GNUNET_PeerIdentity source_peer)
3960 /* I am the source peer. */
3961 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (&source_peer,
3964 /* Is the first element of the trail is sender_peer.*/
3965 if (trail_length > 0)
3967 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&trail_peer_list[0],
3973 /* Is finger the sender peer? */
3974 if (0 != GNUNET_CRYPTO_cmp_peer_identity (sender_peer,
3981 /* Get my current location in the trail. */
3982 my_index = search_my_index (trail_peer_list, trail_length);
3986 /* I am the last element in the trail. */
3987 if ((trail_length - 1) == my_index)
3989 /* Is finger the sender_peer? */
3990 if (0 != GNUNET_CRYPTO_cmp_peer_identity (sender_peer,
3996 /* Is peer after me in trail the sender peer? */
3997 if (0 != GNUNET_CRYPTO_cmp_peer_identity (sender_peer,
3998 &trail_peer_list[my_index + 1]))
4007 * FIXME: we should also add a case where we search if we are present in the trail
4009 * Core handle for p2p trail setup result messages.
4011 * @param message message
4012 * @param peer sender of this message.
4013 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
4016 handle_dht_p2p_trail_setup_result(void *cls, const struct GNUNET_PeerIdentity *peer,
4017 const struct GNUNET_MessageHeader *message)
4019 const struct PeerTrailSetupResultMessage *trail_result;
4020 const struct GNUNET_PeerIdentity *trail_peer_list;
4021 struct GNUNET_PeerIdentity next_hop;
4022 struct FriendInfo *target_friend;
4023 struct GNUNET_PeerIdentity querying_peer;
4024 struct GNUNET_PeerIdentity finger_identity;
4025 uint32_t trail_length;
4026 uint64_t ulitmate_destination_finger_value;
4027 uint32_t is_predecessor;
4028 struct GNUNET_HashCode trail_id;
4032 msize = ntohs (message->size);
4033 if (msize < sizeof (struct PeerTrailSetupResultMessage))
4035 GNUNET_break_op (0);
4039 trail_result = (const struct PeerTrailSetupResultMessage *) message;
4040 trail_length = (msize - sizeof (struct PeerTrailSetupResultMessage))/
4041 sizeof (struct GNUNET_PeerIdentity);
4042 if ((msize - sizeof (struct PeerTrailSetupResultMessage)) %
4043 sizeof (struct GNUNET_PeerIdentity) != 0)
4045 GNUNET_break_op (0);
4049 is_predecessor = htonl (trail_result->is_predecessor);
4050 querying_peer = trail_result->querying_peer;
4051 finger_identity = trail_result->finger_identity;
4052 trail_id = trail_result->trail_id;
4053 trail_peer_list = (const struct GNUNET_PeerIdentity *) &trail_result[1];
4054 ulitmate_destination_finger_value =
4055 GNUNET_ntohll (trail_result->ulitmate_destination_finger_value);
4057 /* FIXME: here we are calculating my_index and comparing also in this function.
4058 And we are doing it again here in this function. Re factor the code. */
4059 /* Ensure that sender peer is the peer from which we were expecting the message. */
4060 if (GNUNET_NO == is_sender_peer_correct (trail_peer_list,
4062 peer, finger_identity, querying_peer))
4064 GNUNET_break_op (0);
4065 return GNUNET_SYSERR;
4068 /* Am I the one who initiated the query? */
4069 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (&querying_peer,
4072 /* If I am not my own finger identity, then add routing table entry. */
4073 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &finger_identity))
4075 GDS_ROUTING_add (trail_id, my_identity, *peer);
4078 finger_table_add (finger_identity, trail_peer_list,
4079 trail_length, ulitmate_destination_finger_value,
4080 is_predecessor, trail_id);
4084 /* Get my location in the trail. */
4085 my_index = search_my_index(trail_peer_list, trail_length);
4089 return GNUNET_SYSERR;
4092 /* FIXME: CHECK IF YOU ARE PRESENT MORE THAN ONCE IN THE TRAIL, IF YES
4093 THEN REMOVE ALL THE ENTRIES AND CHOOSE THE PEER THERE.*/
4095 next_hop = trail_result->querying_peer;
4097 next_hop = trail_peer_list[my_index - 1];
4099 /* If the querying_peer is its own finger, then don't add an entry in routing
4100 * table as querying peer will discard the trail. */
4101 if (0 != (GNUNET_CRYPTO_cmp_peer_identity (&(trail_result->querying_peer),
4102 &(trail_result->finger_identity))))
4104 GDS_ROUTING_add (trail_id, next_hop, *peer);
4107 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, &next_hop);
4108 GDS_NEIGHBOURS_send_trail_setup_result (querying_peer, finger_identity,
4109 target_friend, trail_length, trail_peer_list,
4111 ulitmate_destination_finger_value,
4119 * @param trail Trail to be inverted
4120 * @param trail_length Total number of peers in the trail.
4121 * @return Updated trail
4123 static struct GNUNET_PeerIdentity *
4124 invert_trail (const struct GNUNET_PeerIdentity *trail,
4125 unsigned int trail_length)
4129 struct GNUNET_PeerIdentity *inverted_trail;
4131 inverted_trail = GNUNET_malloc (sizeof(struct GNUNET_PeerIdentity) *
4134 j = trail_length - 1;
4135 while (i < trail_length)
4137 inverted_trail[i] = trail[j];
4141 return inverted_trail;
4146 * Return the shortest trail to reach from me to my_predecessor.
4147 * @param my_predecessor my current predecessor.
4148 * @param current_trail Trail from source to me.
4149 * @param current_trail_length Total number of peers in @a current_trail
4150 * @param trail_length [out] Total number of peers in selected trail.
4151 * @return Updated trail from source peer to my_predecessor.
4153 static struct GNUNET_PeerIdentity *
4154 trail_source_to_my_predecessor (const struct GNUNET_PeerIdentity *current_trail,
4155 unsigned int current_trail_length,
4156 unsigned int *trail_length)
4158 struct GNUNET_PeerIdentity *trail_me_to_predecessor;
4159 struct Trail *trail;
4160 struct Trail_Element *trail_element;
4161 struct FingerInfo *my_predecessor;
4163 unsigned int shortest_trail_length = 0;
4164 unsigned int trail_index = 0;
4166 my_predecessor = &finger_table[PREDECESSOR_FINGER_ID];
4168 GNUNET_assert (GNUNET_YES == my_predecessor->is_present);
4170 //if my_predecessor is a friend then don't send back any trail. as
4171 // there is no trail.
4174 /* Choose the shortest path from me to my predecessor. */
4175 for (i = 0; i < my_predecessor->trails_count; i++)
4177 trail = &my_predecessor->trail_list[i];
4178 if (trail->trail_length > shortest_trail_length)
4180 shortest_trail_length = trail->trail_length;
4184 *trail_length = shortest_trail_length;
4185 trail_me_to_predecessor = GNUNET_malloc (sizeof (struct GNUNET_PeerIdentity)
4188 /* Copy the selected trail and send this trail to calling function. */
4190 trail = &my_predecessor->trail_list[trail_index];
4191 trail_element = trail->trail_head;
4192 while ( i < shortest_trail_length)
4194 trail_me_to_predecessor[i] = trail_element->peer;
4196 trail_element = trail_element->next;
4199 return trail_me_to_predecessor;
4204 * FIXME In case predecessor is a friend then do we add it in routing table.
4205 * if not then check the logic of trail teardown in case we compress the trail
4206 * such that friend is finger. then do we remove the entry from end points or
4207 * not. Ideally we should remove the entries from end point.
4208 * Add finger as your predecessor. To add, first generate a new trail id, invert
4209 * the trail to get the trail from me to finger, add an entry in your routing
4210 * table, send add trail message to peers which are part of trail from me to
4211 * finger and add finger in finger table.
4214 * @param trail_length
4217 update_predecessor (struct GNUNET_PeerIdentity finger,
4218 struct GNUNET_PeerIdentity *trail,
4219 unsigned int trail_length)
4221 struct GNUNET_HashCode trail_to_new_predecessor_id;
4222 struct GNUNET_PeerIdentity *trail_to_new_predecessor;
4223 struct FriendInfo *target_friend;
4225 /* Generate trail id for trail from me to new predecessor = finger. */
4226 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_STRONG,
4227 &trail_to_new_predecessor_id,
4228 sizeof (trail_to_new_predecessor_id));
4230 /* Finger is a friend. */
4231 if (trail_length == 0)
4233 trail_to_new_predecessor = NULL;
4234 GDS_ROUTING_add (trail_to_new_predecessor_id, finger, my_identity);
4236 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4241 /* Invert the trail to get the trail from me to finger, NOT including the
4243 trail_to_new_predecessor = invert_trail (trail, trail_length);
4245 /* Add an entry in your routing table. */
4246 GDS_ROUTING_add (trail_to_new_predecessor_id,
4247 trail_to_new_predecessor[trail_length - 1],
4251 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4252 &trail_to_new_predecessor[trail_length - 1]);
4255 /* Add entry in routing table of all peers that are part of trail from me
4256 to finger, including finger. */
4257 GDS_NEIGHBOURS_send_add_trail (my_identity,
4259 trail_to_new_predecessor_id,
4260 trail_to_new_predecessor,
4264 add_new_finger (finger, trail_to_new_predecessor, trail_length,
4265 trail_to_new_predecessor_id, PREDECESSOR_FINGER_ID);
4266 GNUNET_free_non_null (trail_to_new_predecessor);
4270 /* 3. In case you are successor, then
4271 * 3.1 check if you have a predecessor
4272 * 3.2 if no predecessor, then add the source of this message as your
4273 * predecessor. To add, first you should generate a new trail id,
4274 * invert the trail, send add trail message across new trail, add
4275 * an entry in finger table. Now, destination also have routing
4276 * table entry so add in your routing table also.
4277 * 3.3 If its closer than existing one, then do everything in step 1 and
4278 * free existing finger.
4279 * 3.3 If its same as the old one, then do nothing.
4280 * 3.4 if its not same as old one, and between source and old one, old one
4281 * is the correct predecessor, then construct a trail from source
4282 * to your old successor. scan the trail to remove duplicate entries.
4283 * 4. send verify successor result, with trail id of trail from source to
4284 * me. And also send the new trail from source to reach to its probable
4287 * 1. this function is called from both verify and notify.
4288 * 2. so write in a way that it is used in both.
4291 * Check if you have a predecessor.
4292 * 1. if no predecessor, then add finger as your predecessor. To add, first
4293 * generate a new trail id, invert the trail to get the trail from me to finger,
4294 * add an entry in your routing table, send add trail message to peers which
4295 * are part of trail from me to finger and add finger in finger table.
4296 * 2. If there is a predecessor, then compare existing one and finger.
4297 * 2.1 If finger is correct predecessor, then remove current_predecessor. And
4298 * do everything in step 1 to add finger into finger table.
4299 * 2.2 If current_predecessor is correct predecessor, the construct a trail from
4300 * finger to current_predecessor.
4303 * @param trail_length
4307 compare_and_update_predecessor (struct GNUNET_PeerIdentity finger,
4308 struct GNUNET_PeerIdentity *trail,
4309 unsigned int trail_length)
4311 struct FingerInfo *current_predecessor;
4312 struct GNUNET_PeerIdentity *closest_peer;
4313 uint64_t predecessor_value;
4314 unsigned int is_predecessor = 1;
4316 current_predecessor = &finger_table[PREDECESSOR_FINGER_ID];
4318 GNUNET_assert (0 != GNUNET_CRYPTO_cmp_peer_identity (&finger, &my_identity));
4320 /* No predecessor. Add finger as your predecessor. */
4321 if (GNUNET_NO == current_predecessor->is_present)
4323 update_predecessor (finger, trail, trail_length);
4327 predecessor_value = compute_finger_identity_value (PREDECESSOR_FINGER_ID);
4328 closest_peer = select_closest_peer (&finger,
4329 ¤t_predecessor->finger_identity,
4330 predecessor_value, is_predecessor);
4332 /* Finger is the closest predecessor. Remove the existing one and add the new
4334 if (0 == GNUNET_CRYPTO_cmp_peer_identity (closest_peer, &finger))
4336 remove_existing_finger (current_predecessor, PREDECESSOR_FINGER_ID);
4337 update_predecessor (finger, trail, trail_length);
4346 * FIXME: if i have no predecessor and I get a new predecessor but the first
4347 * friend to reach to that hop is congested then?
4348 * 1. check if you are the successor or not.
4349 * 2. if not then get the next hop from routing table, and pass the message,
4350 * 3. In case you are successor, then
4351 * 3.1 check if you have a predecessor
4352 * 3.2 if no predecessor, then add the source of this message as your
4353 * predecessor. To add, first you should generate a new trail id,
4354 * invert the trail, send add trail message across new trail, add
4355 * an entry in finger table. Now, destination also have routing
4356 * table entry so add in your routing table also.
4357 * 3.3 If its closer than existing one, then do everything in step 1 and
4358 * free existing finger.
4359 * 3.3 If its same as the old one, then do nothing.
4360 * 3.4 if its not same as old one, and between source and old one, old one
4361 * is the correct predecessor, then choose the shortest path to reach
4362 * from you to your predecessor. Pass this trail to source of this message.
4363 * It is the responsibility of source peer to scan the trail to reach to
4364 * its new probable successor.
4365 * 4. send verify successor result, with trail id of trail from source to
4366 * me. And also send the trail from me to reach to my predecessor, if
4367 * my_predecessor != source.
4369 * Core handle for p2p verify successor messages.
4370 * @param cls closure
4371 * @param message message
4372 * @param peer peer identity this notification is about
4373 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
4376 handle_dht_p2p_verify_successor(void *cls,
4377 const struct GNUNET_PeerIdentity *peer,
4378 const struct GNUNET_MessageHeader *message)
4380 const struct PeerVerifySuccessorMessage *vsm;
4381 struct GNUNET_HashCode trail_id;
4382 struct GNUNET_PeerIdentity successor;
4383 struct GNUNET_PeerIdentity source_peer;
4384 struct GNUNET_PeerIdentity *trail;
4385 struct GNUNET_PeerIdentity *next_hop;
4386 struct GNUNET_PeerIdentity *trail_to_predecessor;
4387 struct FingerInfo *current_predecessor;
4388 struct FriendInfo *target_friend;
4389 unsigned int trail_to_predecessor_length;
4391 unsigned int trail_length;
4393 msize = ntohs (message->size);
4395 /* Here we pass trail to reach from source to successor, and in case successor
4396 * does not have any predecessor, then we will add source as my predecessor.
4397 * So we pass the trail along with trail id. */
4398 if (msize < sizeof (struct PeerVerifySuccessorMessage))
4400 GNUNET_break_op (0);
4404 vsm = (const struct PeerVerifySuccessorMessage *) message;
4405 trail_length = (msize - sizeof (struct PeerVerifySuccessorMessage))/
4406 sizeof (struct GNUNET_PeerIdentity);
4407 if ((msize - sizeof (struct PeerVerifySuccessorMessage)) %
4408 sizeof (struct GNUNET_PeerIdentity) != 0)
4410 GNUNET_break_op (0);
4414 trail_id = vsm->trail_id;
4415 source_peer = vsm->source_peer;
4416 successor = vsm->successor;
4417 trail = (struct GNUNET_PeerIdentity *)&vsm[1];
4419 //FIXME: we can have a check if peer is correct peer which should have
4420 // sent this message. use same function is_sender_peer_correct
4421 // but specify direction so that the function can be used in other functions
4424 /* I am not the successor of source_peer. Pass the message to next_hop on
4426 if(0 != (GNUNET_CRYPTO_cmp_peer_identity (&successor, &my_identity)))
4428 next_hop = GDS_ROUTING_get_next_hop (trail_id, GDS_ROUTING_SRC_TO_DEST);
4429 if (NULL == next_hop)
4432 return GNUNET_SYSERR;
4434 GNUNET_assert (NULL !=
4436 GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop)));
4438 GDS_NEIGHBOURS_send_verify_successor_message (source_peer, successor,
4439 trail_id, trail, trail_length,
4444 /* I am the destination of this message. */
4446 /* Check if the source_peer could be our predecessor and if yes then update
4448 compare_and_update_predecessor (source_peer, trail, trail_length);
4450 current_predecessor = &finger_table[PREDECESSOR_FINGER_ID];
4452 /* Is source of this message NOT my predecessor. */
4453 if (0 != (GNUNET_CRYPTO_cmp_peer_identity (¤t_predecessor->finger_identity,
4456 /* if current predecessor is not a friend, we have a trail to reach to it*/
4457 if (NULL == (GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4458 ¤t_predecessor->finger_identity)))
4460 trail_to_predecessor =
4461 trail_source_to_my_predecessor (trail,
4463 &trail_to_predecessor_length);
4468 trail_to_predecessor = NULL;
4469 trail_to_predecessor_length = 0;
4471 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, peer);
4472 GDS_NEIGHBOURS_send_verify_successor_result (source_peer, my_identity,
4473 current_predecessor->finger_identity,
4474 trail_id, trail_to_predecessor,
4475 trail_to_predecessor_length,
4476 GDS_ROUTING_DEST_TO_SRC,
4478 GNUNET_free_non_null (trail_to_predecessor);
4484 * Construct the trail from me to probable successor that goes through current
4485 * successor. Scan this trail to check if you can shortcut the trail somehow.
4486 * In case we can shortcut the trail, don't send trail compression as we don't
4487 * have any entry in routing table.
4488 * @param current_successor
4489 * @param probable_successor
4490 * @param trail_from_curr_to_probable_successor
4491 * @param trail_from_curr_to_probable_successor_length
4492 * @param trail_to_new_successor_length
4495 static struct GNUNET_PeerIdentity *
4496 get_trail_to_new_successor (struct FingerInfo *current_successor,
4497 struct GNUNET_PeerIdentity probable_successor,
4498 const struct GNUNET_PeerIdentity *trail,
4499 unsigned int trail_length,
4500 unsigned int *trail_to_new_successor_length)
4502 struct GNUNET_PeerIdentity *trail_to_new_successor;
4504 /* If the probable successor is a friend, then we don't need to have a trail
4506 if (NULL != GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4507 &probable_successor))
4509 trail_to_new_successor = NULL;
4510 *trail_to_new_successor_length = 0;
4511 return trail_to_new_successor;
4515 * FIXME: can we some how use the select_finger_trail here??
4516 * complete this logic.
4517 * 1. Choose the shortest trail to reach to current successor.
4518 * 2. append the trail with the current trail
4519 * 3. scan the trail for duplicate elements
4520 * 4. scan the trail for friend
4521 * 5. get the shortest trail.
4522 * 6. send back the trail.
4529 * Compare probable successor and current successor.
4530 * If the probable successor is the correct successor, then construct the trail
4531 * from me to probable successor that goes through current successor. Scan this
4532 * trail to check if you can shortcut the trail somehow. In case we can short
4533 * cut the trail, don't send trail compression as we don't have any entry in
4535 * Once you have scanned trail, then add an entry in finger table.
4536 * Add an entry in routing table (Only if new successor is NOT a friend).
4537 * @param probable_successor Peer which could be our successor
4538 * @param trail_from_curr_to_probable_successor Trail from current successor
4539 * to probable successor, NOT
4541 * @param trail_from_curr_to_probable_successor_length Total number of peers
4542 * in @a trail_from_curr_to_probable_successor
4545 compare_and_update_successor (struct GNUNET_PeerIdentity probable_successor,
4546 const struct GNUNET_PeerIdentity *trail_from_curr_to_probable_successor,
4547 unsigned int trail_from_curr_to_probable_successor_length)
4549 struct GNUNET_PeerIdentity *closest_peer;
4550 struct GNUNET_PeerIdentity *trail_to_new_successor;
4551 struct GNUNET_HashCode trail_id;
4552 unsigned int trail_to_new_successor_length;
4553 uint64_t successor_value;
4554 struct FingerInfo *current_successor;
4555 struct FriendInfo *target_friend;
4556 unsigned int is_predecessor = 0;
4558 current_successor = &finger_table[0];
4559 GNUNET_assert (GNUNET_YES == current_successor->is_present);
4561 /* Compute the 64 bit value of successor identity. We need this as we need to
4562 * find the closest peer w.r.t this value.*/
4563 successor_value = compute_finger_identity_value (0);
4564 closest_peer = select_closest_peer (¤t_successor->finger_identity,
4565 &probable_successor,
4566 successor_value, is_predecessor);
4568 /* If the current_successor is the closest one, then exit. */
4569 if (0 == GNUNET_CRYPTO_cmp_peer_identity (closest_peer,
4570 ¤t_successor->finger_identity))
4573 /* probable successor is the closest_peer. */
4575 /* Get the trail to reach to your new successor. */
4576 trail_to_new_successor = get_trail_to_new_successor (current_successor,
4578 trail_from_curr_to_probable_successor,
4579 trail_from_curr_to_probable_successor_length,
4580 &trail_to_new_successor_length);
4581 /* Remove the existing successor. */
4582 remove_existing_finger (current_successor, 0);
4584 /* Generate a new trail id to reach to your new successor. */
4585 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_STRONG,
4586 &trail_id, sizeof (trail_id));
4587 add_new_finger (probable_successor, trail_to_new_successor,
4588 trail_to_new_successor_length, trail_id, 0);
4590 /* If probable successor is not a friend, then add an entry in your own
4592 if (trail_to_new_successor_length > 0)
4594 GDS_ROUTING_add (trail_id, my_identity, trail_to_new_successor[0]);
4595 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4596 &trail_to_new_successor[0]);
4600 GDS_ROUTING_add (trail_id, my_identity, probable_successor);
4601 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4602 &probable_successor);
4605 GDS_NEIGHBOURS_send_notify_new_successor (my_identity, probable_successor,
4606 trail_from_curr_to_probable_successor,
4607 trail_from_curr_to_probable_successor_length,
4615 * 1. If you are not the querying peer then pass on the message,
4616 * 2. If you are querying peer, then
4617 * 2.1 is new successor same as old one
4618 * 2.1.1 if yes then do noting
4619 * 2.1.2 if no then you need to notify the new one about your existence,
4620 * 2.1.2,1 also you need to remove the older successor, remove entry
4621 * from finger table, send trail teardown message across all the trail
4622 * of older successor. Call notify new successor with new trail id
4623 * and new trail to reach it.
4624 * Core handle for p2p verify successor result messages.
4625 * @param cls closure
4626 * @param message message
4627 * @param peer peer identity this notification is about
4628 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
4631 handle_dht_p2p_verify_successor_result(void *cls,
4632 const struct GNUNET_PeerIdentity *peer,
4633 const struct GNUNET_MessageHeader *message)
4635 const struct PeerVerifySuccessorResultMessage *vsrm;
4636 enum GDS_ROUTING_trail_direction trail_direction;
4637 struct GNUNET_PeerIdentity querying_peer;
4638 struct GNUNET_HashCode trail_id;
4639 struct GNUNET_PeerIdentity *next_hop;
4640 struct FriendInfo *target_friend;
4641 struct GNUNET_PeerIdentity probable_successor;
4642 const struct GNUNET_PeerIdentity *trail;
4643 unsigned int trail_length;
4646 msize = ntohs (message->size);
4647 /* We send a trail to reach from old successor to new successor, if
4648 * old_successor != new_successor.*/
4649 if (msize < sizeof (struct PeerVerifySuccessorResultMessage))
4651 GNUNET_break_op (0);
4655 vsrm = (const struct PeerVerifySuccessorResultMessage *) message;
4656 trail_length = (msize - sizeof (struct PeerVerifySuccessorResultMessage))/
4657 sizeof (struct GNUNET_PeerIdentity);
4659 if ((msize - sizeof (struct PeerVerifySuccessorResultMessage)) %
4660 sizeof (struct GNUNET_PeerIdentity) != 0)
4662 GNUNET_break_op (0);
4666 trail = (const struct GNUNET_PeerIdentity *) &vsrm[1];
4667 querying_peer = vsrm->querying_peer;
4668 trail_direction = ntohl (vsrm->trail_direction);
4669 trail_id = vsrm->trail_id;
4670 probable_successor = vsrm->probable_successor;
4672 //FIXME: add a check to ensure that peer from which you got the message is
4674 /* I am the querying_peer. */
4675 if(0 == (GNUNET_CRYPTO_cmp_peer_identity (&querying_peer, &my_identity)))
4677 compare_and_update_successor (probable_successor, trail, trail_length);
4681 /*If you are not the querying peer then pass on the message */
4682 GNUNET_assert (NULL != (next_hop =
4683 GDS_ROUTING_get_next_hop (trail_id, trail_direction)));
4684 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop);
4685 GDS_NEIGHBOURS_send_verify_successor_result (querying_peer,
4686 vsrm->current_successor,
4687 probable_successor, trail_id,
4690 trail_direction, target_friend);
4696 * Add entry in your routing table if source of the message is not a friend.
4697 * Irrespective if destination peer accepts source peer as predecessor or not,
4698 * we need to add an entry. So, that in next round to verify successor, source
4699 * is able to reach to its successor.
4700 * Check if you are the new successor of this message
4701 * 1. If yes the call function compare_and_update_successor(). This function
4702 * checks if source is real predecessor or not and take action accordingly.
4703 * 2. If not then find the next hop to find the message from the trail that
4704 * you got from the message and pass on the message.
4705 * Core handle for p2p notify new successor messages.
4706 * @param cls closure
4707 * @param message message
4708 * @param peer peer identity this notification is about
4709 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
4712 handle_dht_p2p_notify_new_successor(void *cls,
4713 const struct GNUNET_PeerIdentity *peer,
4714 const struct GNUNET_MessageHeader *message)
4716 const struct PeerNotifyNewSuccessorMessage *nsm;
4717 struct GNUNET_PeerIdentity *trail;
4718 struct GNUNET_PeerIdentity source;
4719 struct GNUNET_PeerIdentity new_successor;
4720 struct GNUNET_HashCode trail_id;
4721 struct GNUNET_PeerIdentity next_hop;
4722 struct FriendInfo *target_friend;
4725 uint32_t trail_length;
4727 msize = ntohs (message->size);
4728 /* We have the trail to reach from source to new successor. */
4729 if (msize < sizeof (struct PeerNotifyNewSuccessorMessage))
4731 GNUNET_break_op (0);
4735 nsm = (const struct PeerNotifyNewSuccessorMessage *) message;
4736 trail_length = (msize - sizeof (struct PeerNotifyNewSuccessorMessage))/
4737 sizeof (struct GNUNET_PeerIdentity);
4738 if ((msize - sizeof (struct PeerTrailRejectionMessage)) %
4739 sizeof (struct GNUNET_PeerIdentity) != 0)
4741 GNUNET_break_op (0);
4745 trail = (struct GNUNET_PeerIdentity *) &nsm[1];
4746 source = nsm->source_peer;
4747 new_successor = nsm->new_successor;
4748 trail_id = nsm->trail_id;
4750 //FIXME: add a check to make sure peer is correct.
4752 /* I am the new_successor to source_peer. */
4753 if ( 0 == GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &new_successor))
4755 /* Add an entry in routing table only if new predecessor is not a friend. */
4756 if (NULL == GNUNET_CONTAINER_multipeermap_get(friend_peermap, &source))
4758 GDS_ROUTING_add (trail_id, *peer, my_identity);
4760 compare_and_update_predecessor (source, trail, trail_length);
4764 /* I am part of trail to reach to successor. */
4765 my_index = search_my_index (trail, trail_length);
4768 GNUNET_break_op (0);
4769 return GNUNET_SYSERR;
4771 if (trail_length == my_index)
4772 next_hop = new_successor;
4774 next_hop = trail[my_index + 1];
4776 /* Add an entry in routing table for trail from source to its new successor. */
4777 GNUNET_assert (GNUNET_OK == GDS_ROUTING_add (trail_id, *peer, next_hop));
4778 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, &next_hop);
4779 GDS_NEIGHBOURS_send_notify_new_successor (source, new_successor, trail,
4781 trail_id, target_friend);
4788 * 1. Set the congestion timeout for the friend which is congested and sent
4790 * 2. Check if you were the source of this message
4791 * 2.1 If yes then exit. find_finger_trail_task is scheduled periodically.
4792 * So, we will eventually send a new request to setup trail to finger.
4793 * 2. Check if you can handle more trails through you. (Routing table space)
4794 * 2.1 If not then you are congested. Set your congestion time and pass this
4795 * message to peer before you in the trail setup so far.
4796 * 2.2 If yes, the call find_successor(). It will give you the next hop to
4797 * pass this message.
4798 * 2.2.1 If you are the final destination, then send back the trail setup
4800 * 2.2.2 If you are not the final dest, then send trail setup message to
4802 * Core handler for P2P trail rejection message
4803 * @param cls closure
4804 * @param message message
4805 * @param peer peer identity this notification is about
4806 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
4809 handle_dht_p2p_trail_setup_rejection (void *cls,
4810 const struct GNUNET_PeerIdentity *peer,
4811 const struct GNUNET_MessageHeader *message)
4813 const struct PeerTrailRejectionMessage *trail_rejection;
4814 unsigned int trail_length;
4815 const struct GNUNET_PeerIdentity *trail_peer_list;
4816 struct FriendInfo *target_friend;
4817 struct GNUNET_TIME_Relative congestion_timeout;
4818 struct GNUNET_HashCode trail_id;
4819 struct GNUNET_PeerIdentity next_destination;
4820 struct GNUNET_HashCode new_intermediate_trail_id;
4821 struct GNUNET_PeerIdentity next_peer;
4822 struct GNUNET_PeerIdentity source;
4823 struct GNUNET_PeerIdentity *next_hop;
4824 uint64_t ultimate_destination_finger_value;
4825 unsigned int is_predecessor;
4828 msize = ntohs (message->size);
4829 /* We are passing the trail setup so far. */
4830 if (msize < sizeof (struct PeerTrailRejectionMessage))
4832 GNUNET_break_op (0);
4836 trail_rejection = (const struct PeerTrailRejectionMessage *) message;
4837 trail_length = (msize - sizeof (struct PeerTrailRejectionMessage))/
4838 sizeof (struct GNUNET_PeerIdentity);
4839 if ((msize - sizeof (struct PeerTrailRejectionMessage)) %
4840 sizeof (struct GNUNET_PeerIdentity) != 0)
4842 GNUNET_break_op (0);
4846 trail_peer_list = (const struct GNUNET_PeerIdentity *)&trail_rejection[1];
4847 is_predecessor = ntohl (trail_rejection->is_predecessor);
4848 congestion_timeout = trail_rejection->congestion_time;
4849 source = trail_rejection->source_peer;
4850 trail_id = trail_rejection->trail_id;
4851 ultimate_destination_finger_value =
4852 GNUNET_ntohll (trail_rejection->ultimate_destination_finger_value);
4854 /* First set the congestion time of the friend that sent you this message. */
4855 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, peer);
4856 target_friend->congestion_timestamp =
4857 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(),
4858 congestion_timeout);
4860 /* I am the source peer which wants to setup the trail. Do nothing.
4861 * send_find_finger_trail_task is scheduled periodically.*/
4862 if(0 == (GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &source)))
4865 /* If I am congested then pass this message to peer before me in trail. */
4866 if(GNUNET_YES == GDS_ROUTING_threshold_reached())
4868 struct GNUNET_PeerIdentity *new_trail;
4869 unsigned int new_trail_length;
4871 /* Remove yourself from the trail setup so far. */
4872 if (trail_length == 1)
4875 new_trail_length = 0;
4880 memcpy (&next_hop , &trail_peer_list[trail_length - 2],
4881 sizeof (struct GNUNET_PeerIdentity));
4883 /* Remove myself from the trail. */
4884 new_trail_length = trail_length -1;
4885 new_trail = GNUNET_malloc (new_trail_length * sizeof (struct GNUNET_PeerIdentity));
4886 memcpy (new_trail, trail_peer_list, new_trail_length * sizeof (struct GNUNET_PeerIdentity));
4889 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop);
4890 GDS_NEIGHBOURS_send_trail_rejection (source,
4891 ultimate_destination_finger_value,
4892 my_identity, is_predecessor,
4893 new_trail,new_trail_length,trail_id,
4894 target_friend, CONGESTION_TIMEOUT);
4895 GNUNET_free (new_trail);
4899 /* Look for next_hop to pass the trail setup message */
4900 next_hop = find_successor (ultimate_destination_finger_value,
4902 &new_intermediate_trail_id,
4905 /* Am I the final destination? */
4906 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (next_hop, &my_identity)))
4908 /* Add an entry in routing table only
4909 * 1. If I am not the original source which sent the request for trail setup
4910 * 2. If trail length > 0.
4911 * NOTE: In case trail length > 0 and source is my friend, then also I add
4912 * an entry in routing table,as we will send a trail compression message
4915 if ((0 != GNUNET_CRYPTO_cmp_peer_identity (&source, &my_identity)) ||
4917 GNUNET_assert (GNUNET_YES == GDS_ROUTING_add (trail_id, *peer, my_identity));
4919 if (0 == trail_length)
4922 next_peer = trail_peer_list[trail_length-1];
4924 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, &next_peer);
4925 GDS_NEIGHBOURS_send_trail_setup_result (source,
4927 target_friend, trail_length,
4930 ultimate_destination_finger_value,
4935 struct GNUNET_PeerIdentity peer_list[trail_length + 1];
4937 memcpy (peer_list, trail_peer_list, trail_length * sizeof (struct GNUNET_PeerIdentity));
4938 peer_list[trail_length] = my_identity;
4940 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop);
4941 GDS_NEIGHBOURS_send_trail_setup (source,
4942 ultimate_destination_finger_value,
4944 target_friend, trail_length + 1, peer_list,
4945 is_predecessor, trail_id,
4946 &new_intermediate_trail_id);
4948 GNUNET_free (next_hop);
4954 * If you are the new first friend, then update prev hop to source of this message
4955 * else get the next hop and pass this message forward to ultimately reach
4957 * Core handle for p2p trail tear compression messages.
4958 * @param cls closure
4959 * @param message message
4960 * @param peer peer identity this notification is about
4961 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
4964 handle_dht_p2p_trail_compression (void *cls, const struct GNUNET_PeerIdentity *peer,
4965 const struct GNUNET_MessageHeader *message)
4967 const struct PeerTrailCompressionMessage *trail_compression;
4968 struct GNUNET_PeerIdentity *next_hop;
4969 struct FriendInfo *target_friend;
4970 struct GNUNET_HashCode trail_id;
4973 msize = ntohs (message->size);
4974 /* Here we pass only the trail id. */
4975 if (msize != sizeof (struct PeerTrailCompressionMessage))
4977 GNUNET_break_op (0);
4981 trail_compression = (const struct PeerTrailCompressionMessage *) message;
4982 trail_id = trail_compression->trail_id;
4983 //FIXME: again check if peer is the correct peer. same logic as
4984 //trail teardown make a generic function.
4986 /* Am I the new first friend to reach to finger of this trail. */
4987 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (&(trail_compression->new_first_friend),
4990 /* Update your prev hop to source of this message. */
4991 GDS_ROUTING_update_trail_prev_hop (trail_id,
4992 trail_compression->source_peer);
4996 /* Pass the message to next hop to finally reach to new_first_friend. */
4997 next_hop = GDS_ROUTING_get_next_hop (trail_id, GDS_ROUTING_SRC_TO_DEST);
4998 if (NULL == next_hop)
5004 GNUNET_assert (NULL != (target_friend =
5005 GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop)));
5006 GDS_NEIGHBOURS_send_trail_compression (trail_compression->source_peer,
5008 trail_compression->new_first_friend,
5015 * Remove entry from your own routing table and pass the message to next
5016 * peer in the trail.
5017 * Core handler for trail teardown message.
5018 * @param cls closure
5019 * @param message message
5020 * @param peer sender of this messsage.
5021 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
5024 handle_dht_p2p_trail_teardown (void *cls, const struct GNUNET_PeerIdentity *peer,
5025 const struct GNUNET_MessageHeader *message)
5027 const struct PeerTrailTearDownMessage *trail_teardown;
5028 enum GDS_ROUTING_trail_direction trail_direction;
5029 struct GNUNET_HashCode trail_id;
5030 //struct GNUNET_PeerIdentity *prev_hop;
5031 struct GNUNET_PeerIdentity *next_hop;
5033 msize = ntohs (message->size);
5035 /* Here we pass only the trail id. */
5036 if (msize != sizeof (struct PeerTrailTearDownMessage))
5038 GNUNET_break_op (0);
5042 trail_teardown = (const struct PeerTrailTearDownMessage *) message;
5043 trail_direction = ntohl (trail_teardown->trail_direction);
5044 trail_id = trail_teardown->trail_id;
5046 /* Check if peer is the real peer from which we should get this message.*/
5047 /* Get the prev_hop for this trail by getting the next hop in opposite direction. */
5048 /* FIXME: is using negation of trail direction correct. */
5050 GNUNET_assert (NULL != (prev_hop =
5051 GDS_ROUTING_get_next_hop (trail_id, !trail_direction)));
5052 if (0 != GNUNET_CRYPTO_cmp_peer_identity (prev_hop, peer))
5055 return GNUNET_SYSERR;
5059 next_hop = GDS_ROUTING_get_next_hop (trail_id, trail_direction);
5060 if (NULL == next_hop)
5063 return GNUNET_SYSERR;
5066 GNUNET_assert (GNUNET_YES == GDS_ROUTING_remove_trail (trail_id));
5068 /* If next_hop is my_identity, it means I am the final destination. */
5069 if (0 == GNUNET_CRYPTO_cmp_peer_identity (next_hop, &my_identity))
5072 /* If not final destination, then send a trail teardown message to next hop.*/
5073 GDS_NEIGHBOURS_send_trail_teardown (trail_id, trail_direction, next_hop);
5074 //GNUNET_free_non_null (next_hop);
5080 * Add an entry in your routing table. If you are destination of this message
5081 * then next_hop in routing table should be your own identity. If you are NOT
5082 * destination, then get the next hop and forward message to it.
5083 * Core handle for p2p add trail message.
5084 * @param cls closure
5085 * @param message message
5086 * @param peer peer identity this notification is about
5087 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
5090 handle_dht_p2p_add_trail (void *cls, const struct GNUNET_PeerIdentity *peer,
5091 const struct GNUNET_MessageHeader *message)
5093 const struct PeerAddTrailMessage *add_trail;
5094 const struct GNUNET_PeerIdentity *trail;
5095 struct GNUNET_HashCode trail_id;
5096 struct GNUNET_PeerIdentity destination_peer;
5097 struct GNUNET_PeerIdentity source_peer;
5098 struct GNUNET_PeerIdentity next_hop;
5099 unsigned int trail_length;
5100 unsigned int my_index;
5103 msize = ntohs (message->size);
5104 /* In this message we pass the whole trail from source to destination as we
5105 * are adding that trail.*/
5106 if (msize < sizeof (struct PeerAddTrailMessage))
5108 GNUNET_break_op (0);
5112 add_trail = (const struct PeerAddTrailMessage *) message;
5113 trail_length = (msize - sizeof (struct PeerAddTrailMessage))/
5114 sizeof (struct GNUNET_PeerIdentity);
5115 if ((msize - sizeof (struct PeerAddTrailMessage)) %
5116 sizeof (struct GNUNET_PeerIdentity) != 0)
5118 GNUNET_break_op (0);
5122 trail = (const struct GNUNET_PeerIdentity *)&add_trail[1];
5123 destination_peer = add_trail->destination_peer;
5124 source_peer = add_trail->source_peer;
5125 trail_id = add_trail->trail_id;
5127 //FIXME: add a check that sender peer is not malicious. Make it a generic
5128 // function so that it can be used in all other functions where we need the
5129 // same functionality.
5131 /* I am not the destination of the trail. */
5132 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &destination_peer))
5134 struct FriendInfo *target_friend;
5136 /* Get my location in the trail. */
5137 my_index = search_my_index (trail, trail_length);
5138 if (GNUNET_SYSERR == my_index)
5140 GNUNET_break_op (0);
5141 return GNUNET_SYSERR;
5145 next_hop = source_peer;
5147 next_hop = trail[trail_length - 1];
5149 /* Add in your routing table. */
5150 GNUNET_assert (GNUNET_OK == GDS_ROUTING_add (trail_id, next_hop, *peer));
5151 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, &next_hop);
5152 GDS_NEIGHBOURS_send_add_trail (source_peer, destination_peer, trail_id,
5153 trail, trail_length, target_friend);
5157 /* I am the destination. Add an entry in routing table. */
5158 GNUNET_assert (GNUNET_OK == GDS_ROUTING_add (trail_id, *peer, my_identity));
5164 * Free the finger trail in which the first friend to reach to a finger is
5165 * disconnected_friend. Also remove entry from routing table for that particular
5167 * @param disconnected_friend PeerIdentity of friend which got disconnected
5168 * @param remove_finger Finger whose trail we need to check if it has
5169 * disconnected_friend as the first hop.
5170 * @return Total number of trails in which disconnected_friend was the first
5174 remove_matching_trails (const struct GNUNET_PeerIdentity *disconnected_friend,
5175 struct FingerInfo *remove_finger)
5177 unsigned int matching_trails_count;
5180 /* Number of trails with disconnected_friend as the first hop in the trail
5181 * to reach from me to remove_finger, NOT including endpoints. */
5182 matching_trails_count = 0;
5184 /* Iterate over all the trails of finger. */
5185 for (i = 0; i < remove_finger->trails_count; i++)
5187 struct Trail *trail;
5188 trail = &remove_finger->trail_list[i];
5190 if (GNUNET_NO == trail->is_present)
5193 /*FIXME: This is here to ensure that no finger which is a friend should ever call this
5194 function. remove afterwards.*/
5195 GNUNET_assert (trail->trail_length > 0);
5197 /* First friend to reach to finger is disconnected_peer. */
5198 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&trail->trail_head->peer,
5199 disconnected_friend))
5201 struct GNUNET_PeerIdentity *next_hop;
5202 struct FriendInfo *remove_friend;
5204 remove_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
5205 disconnected_friend);
5206 remove_friend->trails_count--;
5207 next_hop = GDS_ROUTING_get_next_hop (trail->trail_id, GDS_ROUTING_SRC_TO_DEST);
5208 GNUNET_assert (0 == (GNUNET_CRYPTO_cmp_peer_identity (disconnected_friend,
5210 matching_trails_count++;
5211 GDS_ROUTING_remove_trail (trail->trail_id);
5214 trail->is_present = GNUNET_NO;
5217 return matching_trails_count;
5222 * FIXME; make sure you handle friend correctle. remove entry from you
5223 * routing table if you are the source.
5224 * Iterate over finger_table entries.
5225 * 0. Ignore finger which is my_identity or if no valid entry present at
5226 * that finger index.
5227 * 1. If disconnected_friend is a finger, then remove the routing entry from
5228 your own table. Free the trail.
5229 * 2. Check if disconnected_friend is the first friend in the trail to reach to a finger.
5230 * 2.1 Remove all the trails and entry from routing table in which disconnected
5231 * friend is the first friend in the trail. If disconnected_friend is the
5232 * first friend in all the trails to reach finger, then remove the finger.
5233 * @param disconnected_friend Peer identity of friend which got disconnected.
5236 remove_matching_fingers (const struct GNUNET_PeerIdentity *disconnected_friend)
5238 struct FingerInfo *remove_finger;
5239 struct FriendInfo *remove_friend;
5240 int removed_trails_count;
5243 /* Iterate over finger table entries. */
5244 for (i = 0; i < MAX_FINGERS; i++)
5246 remove_finger = &finger_table[i];
5248 /* No finger stored at this trail index. */
5249 if (GNUNET_NO == remove_finger->is_present)
5252 /* I am my own finger, then ignore this finger. */
5253 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&remove_finger->finger_identity,
5257 /* Is disconnected_friend a finger? */
5258 if (0 == GNUNET_CRYPTO_cmp_peer_identity (disconnected_friend,
5259 &remove_finger->finger_identity))
5261 struct GNUNET_PeerIdentity *next_hop;
5262 struct GNUNET_HashCode trail_id;
5264 GNUNET_assert (GNUNET_YES == (remove_finger->trail_list[0].is_present));
5265 trail_id = remove_finger->trail_list[0].trail_id;
5267 GNUNET_assert (NULL !=
5269 GDS_ROUTING_get_next_hop (trail_id, GDS_ROUTING_SRC_TO_DEST)));
5270 /* As finger is a friend, you have no trail as such but you have entry in routing
5271 * table of source and dest, so next_hop will be same as finger identity. */
5273 (GNUNET_CRYPTO_cmp_peer_identity (next_hop,
5274 &remove_finger->finger_identity)));
5275 GDS_ROUTING_remove_trail (trail_id);
5276 remove_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
5277 disconnected_friend);
5278 remove_friend->trails_count--;
5279 remove_finger->is_present = GNUNET_NO;
5280 memset ((void *)&finger_table[i], 0, sizeof (finger_table[i]));
5284 /* If finger is a friend but not disconnected_friend, then continue. */
5285 if (NULL != GNUNET_CONTAINER_multipeermap_get (friend_peermap,
5286 &remove_finger->finger_identity))
5289 /* Iterate over the list of trails to reach remove_finger. Check if
5290 * disconnected_friend makis the first friend in any of the trail. */
5291 removed_trails_count = remove_matching_trails (disconnected_friend,
5294 /* All the finger trails had disconnected_friend as the first friend,
5295 * so free the finger. */
5296 if (removed_trails_count == remove_finger->trails_count)
5298 remove_finger->is_present = GNUNET_NO;
5299 memset ((void *)&finger_table[i], 0, sizeof (finger_table[i]));
5306 * Method called whenever a peer disconnects.
5308 * @param cls closure
5309 * @param peer peer identity this notification is about
5312 handle_core_disconnect (void *cls,
5313 const struct GNUNET_PeerIdentity *peer)
5315 struct FriendInfo *remove_friend;
5317 /* If disconnected to own identity, then return. */
5318 if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
5321 GNUNET_assert (NULL != (remove_friend =
5322 GNUNET_CONTAINER_multipeermap_get (friend_peermap, peer)));
5324 /* Remove fingers with peer as first friend or if peer is a finger. */
5325 remove_matching_fingers (peer);
5327 /* Remove any trail from routing table of which peer is a part of. This function
5328 * internally sends a trail teardown message in the direction of which
5329 * disconnected peer is not part of. */
5330 GDS_ROUTING_remove_trail_by_peer (peer);
5332 GNUNET_assert (0 == remove_friend->trails_count);
5333 /* Remove peer from friend_peermap. */
5334 GNUNET_assert (GNUNET_YES ==
5335 GNUNET_CONTAINER_multipeermap_remove (friend_peermap,
5339 if (0 != GNUNET_CONTAINER_multipeermap_size (friend_peermap))
5342 /* If there are no more friends in friend_peermap, then don't schedule
5343 * find_finger_trail_task. */
5344 if (GNUNET_SCHEDULER_NO_TASK != find_finger_trail_task)
5346 GNUNET_SCHEDULER_cancel (find_finger_trail_task);
5347 find_finger_trail_task = GNUNET_SCHEDULER_NO_TASK;
5356 * Method called whenever a peer connects.
5358 * @param cls closure
5359 * @param peer_identity peer identity this notification is about
5362 handle_core_connect (void *cls, const struct GNUNET_PeerIdentity *peer_identity)
5364 struct FriendInfo *friend;
5366 /* Check for connect to self message */
5367 if (0 == memcmp (&my_identity, peer_identity, sizeof (struct GNUNET_PeerIdentity)))
5370 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connected to %s\n", GNUNET_i2s (peer_identity));
5372 /* If peer already exists in our friend_peermap, then exit. */
5373 if (GNUNET_YES == GNUNET_CONTAINER_multipeermap_contains (friend_peermap,
5380 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# peers connected"), 1,
5383 friend = GNUNET_new (struct FriendInfo);
5384 friend->id = *peer_identity;
5386 GNUNET_assert (GNUNET_OK ==
5387 GNUNET_CONTAINER_multipeermap_put (friend_peermap,
5388 peer_identity, friend,
5389 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
5392 /* got a first connection, good time to start with FIND FINGER TRAIL requests...*/
5393 if (GNUNET_SCHEDULER_NO_TASK == find_finger_trail_task)
5394 find_finger_trail_task = GNUNET_SCHEDULER_add_now (&send_find_finger_trail_message, NULL);
5399 * To be called on core init/fail.
5401 * @param cls service closure
5402 * @param identity the public identity of this peer
5405 core_init (void *cls,
5406 const struct GNUNET_PeerIdentity *identity)
5408 my_identity = *identity;
5409 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
5410 "my_indentity = %s\n",GNUNET_i2s(&my_identity));
5415 * Initialize finger table entries.
5418 finger_table_init ()
5423 /* FIXME: here we have set the whole entry of finger table to 0, so do we
5424 * need to initialize the trails to 0 */
5425 for(i = 0; i < MAX_FINGERS; i++)
5427 finger_table[i].is_present = GNUNET_NO;
5428 for (j = 0; j < MAXIMUM_TRAILS_PER_FINGER; j++)
5429 finger_table[i].trail_list[j].is_present = GNUNET_NO;
5430 memset ((void *)&finger_table[i], 0, sizeof (finger_table[i]));
5436 * Initialize neighbours subsystem.
5437 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
5440 GDS_NEIGHBOURS_init (void)
5442 static struct GNUNET_CORE_MessageHandler core_handlers[] = {
5443 {&handle_dht_p2p_put, GNUNET_MESSAGE_TYPE_XDHT_P2P_PUT, 0},
5444 {&handle_dht_p2p_get, GNUNET_MESSAGE_TYPE_XDHT_P2P_GET, 0},
5445 {&handle_dht_p2p_get_result, GNUNET_MESSAGE_TYPE_XDHT_P2P_GET_RESULT, 0},
5446 {&handle_dht_p2p_trail_setup, GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP, 0},
5447 {&handle_dht_p2p_trail_setup_result, GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP_RESULT, 0},
5448 {&handle_dht_p2p_verify_successor, GNUNET_MESSAGE_TYPE_XDHT_P2P_VERIFY_SUCCESSOR, 0},
5449 {&handle_dht_p2p_verify_successor_result, GNUNET_MESSAGE_TYPE_XDHT_P2P_VERIFY_SUCCESSOR_RESULT, 0},
5450 {&handle_dht_p2p_notify_new_successor, GNUNET_MESSAGE_TYPE_XDHT_P2P_NOTIFY_NEW_SUCCESSOR, 0},
5451 {&handle_dht_p2p_trail_setup_rejection, GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP_REJECTION, 0},
5452 {&handle_dht_p2p_trail_compression, GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_COMPRESSION,
5453 sizeof (struct PeerTrailCompressionMessage)},
5454 {&handle_dht_p2p_trail_teardown, GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_TEARDOWN,
5455 sizeof (struct PeerTrailTearDownMessage)},
5456 {&handle_dht_p2p_add_trail, GNUNET_MESSAGE_TYPE_XDHT_P2P_ADD_TRAIL, 0},
5461 GNUNET_CORE_connect (GDS_cfg, NULL, &core_init, &handle_core_connect,
5462 &handle_core_disconnect, NULL, GNUNET_NO, NULL,
5463 GNUNET_NO, core_handlers);
5464 if (NULL == core_api)
5465 return GNUNET_SYSERR;
5467 friend_peermap = GNUNET_CONTAINER_multipeermap_create (256, GNUNET_NO);
5468 finger_table_init ();
5475 * Shutdown neighbours subsystem.
5478 GDS_NEIGHBOURS_done (void)
5480 if (NULL == core_api)
5483 GNUNET_CORE_disconnect (core_api);
5486 GNUNET_assert (0 == GNUNET_CONTAINER_multipeermap_size (friend_peermap));
5487 GNUNET_CONTAINER_multipeermap_destroy (friend_peermap);
5488 friend_peermap = NULL;
5490 if (GNUNET_SCHEDULER_NO_TASK != find_finger_trail_task)
5493 GNUNET_SCHEDULER_cancel (find_finger_trail_task);
5494 find_finger_trail_task = GNUNET_SCHEDULER_NO_TASK;
5502 * @return my identity
5504 struct GNUNET_PeerIdentity
5505 GDS_NEIGHBOURS_get_my_id (void)