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)
1323 struct GNUNET_PeerIdentity *test_peer;
1324 test_peer = GNUNET_new (struct GNUNET_PeerIdentity);
1325 memcpy (test_peer, &peer, sizeof (struct GNUNET_PeerIdentity));
1326 GNUNET_assert (NULL != (target_friend =
1327 GNUNET_CONTAINER_multipeermap_get (friend_peermap, test_peer)));
1329 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1331 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# P2P messages dropped due to full queue"),
1335 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1336 pending->importance = 0; /* FIXME */
1337 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1338 ttdm = (struct PeerTrailTearDownMessage *) &pending[1];
1339 pending->msg = &ttdm->header;
1340 ttdm->header.size = htons (msize);
1341 ttdm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_TEARDOWN);
1342 ttdm->trail_id = trail_id;
1343 ttdm->trail_direction = htonl (trail_direction);
1345 /* Send the message to chosen friend. */
1346 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1347 target_friend->pending_count++;
1348 process_friend_queue (target_friend);
1353 * Construct a verify successor result message and send it to target_friend
1354 * @param querying_peer Peer which sent the verify successor message.
1355 * @param source_successor Current_successor of @a querying_peer.
1356 * @param current_predecessor Current predecessor of @a successor. Could be same
1357 * or different from @a querying_peer.
1358 * @param trail_id Unique identifier of the trail from @a querying_peer to
1359 * @a successor, NOT including them.
1360 * @param trail List of peers which are part of trail from @a querying_peer to
1361 * @a successor, NOT including them.
1362 * @param trail_length Total number of peers in @a trail
1363 * @param trail_direction Direction in which we are sending the message. In this
1364 * case we are sending result from @a successor to @a querying_peer.
1365 * @param target_friend Next friend to get this message.
1368 GDS_NEIGHBOURS_send_verify_successor_result (struct GNUNET_PeerIdentity querying_peer,
1369 struct GNUNET_PeerIdentity current_successor,
1370 struct GNUNET_PeerIdentity probable_successor,
1371 struct GNUNET_HashCode trail_id,
1372 const struct GNUNET_PeerIdentity *trail,
1373 unsigned int trail_length,
1374 enum GDS_ROUTING_trail_direction trail_direction,
1375 struct FriendInfo *target_friend)
1377 struct PeerVerifySuccessorResultMessage *vsmr;
1378 struct P2PPendingMessage *pending;
1379 struct GNUNET_PeerIdentity *peer_list;
1382 msize = sizeof (struct PeerVerifySuccessorResultMessage) +
1383 (trail_length * sizeof(struct GNUNET_PeerIdentity));
1385 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1391 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1393 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# P2P messages dropped due to full queue"),
1397 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1398 pending->importance = 0; /* FIXME */
1399 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1400 vsmr = (struct PeerVerifySuccessorResultMessage *) &pending[1];
1401 pending->msg = &vsmr->header;
1402 vsmr->header.size = htons (msize);
1403 vsmr->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_VERIFY_SUCCESSOR_RESULT);
1404 vsmr->querying_peer = querying_peer;
1405 vsmr->current_successor = current_successor;
1406 vsmr->probable_successor = probable_successor;
1407 vsmr->trail_direction = htonl (trail_direction);
1408 vsmr->trail_id = trail_id;
1410 if (trail_length > 0)
1412 peer_list = (struct GNUNET_PeerIdentity *) &vsmr[1];
1413 memcpy (peer_list, trail, trail_length * sizeof (struct GNUNET_PeerIdentity));
1416 /* Send the message to chosen friend. */
1417 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1418 target_friend->pending_count++;
1419 process_friend_queue (target_friend);
1424 * Construct a notify new successor message and send it to target_friend
1425 * @param source_peer Peer which wants to notify to its new successor that it
1426 * could be its predecessor.
1427 * @param successor New successor of @a source_peer
1428 * @param successor_trail List of peers in Trail to reach from
1429 * @a source_peer to @a new_successor, NOT including
1431 * @param successor_trail_length Total number of peers in @a new_successor_trail.
1432 * @param successor_trail_id Unique identifier of @a new_successor_trail.
1433 * @param target_friend Next friend to get this message.
1436 GDS_NEIGHBOURS_send_notify_new_successor (struct GNUNET_PeerIdentity source_peer,
1437 struct GNUNET_PeerIdentity successor,
1438 const struct GNUNET_PeerIdentity *successor_trail,
1439 unsigned int successor_trail_length,
1440 struct GNUNET_HashCode succesor_trail_id,
1441 struct FriendInfo *target_friend)
1443 struct PeerNotifyNewSuccessorMessage *nsm;
1444 struct P2PPendingMessage *pending;
1445 struct GNUNET_PeerIdentity *peer_list;
1448 msize = sizeof (struct PeerNotifyNewSuccessorMessage) +
1449 (successor_trail_length * sizeof(struct GNUNET_PeerIdentity));
1451 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1457 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1459 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# P2P messages dropped due to full queue"),
1463 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1464 pending->importance = 0; /* FIXME */
1465 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1466 nsm = (struct PeerNotifyNewSuccessorMessage *) &pending[1];
1467 pending->msg = &nsm->header;
1468 nsm->header.size = htons (msize);
1469 nsm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_NOTIFY_NEW_SUCCESSOR);
1470 nsm->new_successor = successor;
1471 nsm->source_peer = source_peer;
1472 nsm->trail_id = succesor_trail_id;
1474 if (successor_trail_length > 0)
1476 peer_list = (struct GNUNET_PeerIdentity *) &nsm[1];
1477 memcpy (peer_list, successor_trail,
1478 successor_trail_length * sizeof (struct GNUNET_PeerIdentity));
1481 /* Send the message to chosen friend. */
1482 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1483 target_friend->pending_count++;
1484 process_friend_queue (target_friend);
1489 * Construct an add_trail message and send it to target_friend
1490 * @param source_peer Source of the trail.
1491 * @param destination_peer Destination of the trail.
1492 * @param trail_id Unique identifier of the trail from
1493 * @a source_peer to @a destination_peer, NOT including the endpoints.
1494 * @param trail List of peers in Trail from @a source_peer to @a destination_peer,
1495 * NOT including the endpoints.
1496 * @param trail_length Total number of peers in @a trail.
1497 * @param target_friend Next friend to get this message.
1500 GDS_NEIGHBOURS_send_add_trail (struct GNUNET_PeerIdentity source_peer,
1501 struct GNUNET_PeerIdentity destination_peer,
1502 struct GNUNET_HashCode trail_id,
1503 const struct GNUNET_PeerIdentity *trail,
1504 unsigned int trail_length,
1505 struct FriendInfo *target_friend)
1507 struct PeerAddTrailMessage *adm;
1508 struct GNUNET_PeerIdentity *peer_list;
1509 struct P2PPendingMessage *pending;
1512 msize = sizeof (struct PeerAddTrailMessage) +
1513 (trail_length * sizeof(struct GNUNET_PeerIdentity));
1515 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1521 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1523 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# P2P messages dropped due to full queue"),
1527 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1528 pending->importance = 0; /* FIXME */
1529 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1530 adm = (struct PeerAddTrailMessage *) &pending[1];
1531 pending->msg = &adm->header;
1532 adm->header.size = htons (msize);
1533 adm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_ADD_TRAIL);
1534 adm->source_peer = source_peer;
1535 adm->destination_peer = destination_peer;
1536 adm->trail_id = trail_id;
1538 if (trail_length > 0)
1540 peer_list = (struct GNUNET_PeerIdentity *)&adm[1];
1541 memcpy (peer_list, trail, sizeof (struct GNUNET_PeerIdentity) * trail_length);
1543 /* Send the message to chosen friend. */
1544 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1545 target_friend->pending_count++;
1546 process_friend_queue (target_friend);
1552 * Construct a trail compression message and send it to target_friend.
1553 * @param source_peer Source of the trail.
1554 * @param trail_id Unique identifier of trail.
1555 * @param first_friend First hop in compressed trail to reach from source to finger
1556 * @param target_friend Next friend to get this message.
1559 GDS_NEIGHBOURS_send_trail_compression (struct GNUNET_PeerIdentity source_peer,
1560 struct GNUNET_HashCode trail_id,
1561 struct GNUNET_PeerIdentity first_friend,
1562 struct FriendInfo *target_friend)
1564 struct P2PPendingMessage *pending;
1565 struct PeerTrailCompressionMessage *tcm;
1568 msize = sizeof (struct PeerTrailCompressionMessage);
1570 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1576 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1578 GNUNET_STATISTICS_update (GDS_stats,
1579 gettext_noop ("# P2P messages dropped due to full queue"),
1583 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1584 pending->importance = 0; /* FIXME */
1585 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1586 tcm = (struct PeerTrailCompressionMessage *) &pending[1];
1587 pending->msg = &tcm->header;
1588 tcm->header.size = htons (msize);
1589 tcm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_COMPRESSION);
1590 tcm->source_peer = source_peer;
1591 tcm->new_first_friend = first_friend;
1592 tcm->trail_id = trail_id;
1594 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1595 target_friend->pending_count++;
1596 process_friend_queue (target_friend);
1602 * Search my location in trail.
1603 * @param trail List of peers
1604 * @return my_index if found
1605 * -1 if no entry found.
1608 search_my_index (const struct GNUNET_PeerIdentity *trail,
1613 for (i = 0; i < trail_length; i++)
1615 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &trail[i]))
1624 * Check if the friend is congested or have reached maximum number of trails
1625 * it can be part of of.
1626 * @param friend Friend to be checked.
1627 * @return #GNUNET_YES if friend is not congested or have not crossed threshold.
1628 * #GNUNET_NO if friend is either congested or have crossed threshold
1631 is_friend_congested (struct FriendInfo *friend)
1633 if ((friend->trails_count < TRAILS_THROUGH_FRIEND_THRESHOLD) &&
1634 ((0 == GNUNET_TIME_absolute_get_remaining
1635 (friend->congestion_timestamp).rel_value_us)))
1643 * FIXME; not handling the wrap around logic correctly.
1644 * Select closest finger to value.
1645 * @param peer1 First peer
1646 * @param peer2 Second peer
1647 * @param value Value to be compare
1648 * @return Closest peer
1650 static struct GNUNET_PeerIdentity *
1651 select_closest_finger (struct GNUNET_PeerIdentity *peer1,
1652 struct GNUNET_PeerIdentity *peer2,
1655 uint64_t peer1_value;
1656 uint64_t peer2_value;
1658 memcpy (&peer1_value, peer1, sizeof (uint64_t));
1659 memcpy (&peer2_value, peer2, sizeof (uint64_t));
1660 peer1_value = GNUNET_ntohll (peer1_value);
1661 peer2_value = GNUNET_ntohll (peer2_value);
1662 //value = GNUNET_ntohll (value); //FIXME: Is it correct to do it here?
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)
1814 GNUNET_assert (NULL !=
1816 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
1817 &iterator->trail_head->peer)));
1819 /* First friend to reach trail is not free. */
1820 if (GNUNET_YES == is_friend_congested (friend))
1825 /* This is the first time we enter the loop. Set finger trail length to
1826 * trail length of this trail. */
1830 finger_trail->trail_length = iterator->trail_length;
1831 finger_trail->friend = *friend;
1832 finger_trail->trail_id = iterator->trail_id;
1834 else if (finger_trail->trail_length > iterator->trail_length)
1836 /* Check if the trail length of this trail is least seen so far. If yes then
1837 set finger_trail to this trail.*/
1838 finger_trail->friend = *friend;
1839 finger_trail->trail_id = iterator->trail_id;
1840 finger_trail->trail_length = iterator->trail_length;
1844 /* All the first friend in all the trails to reach to finger are either
1845 congested or have crossed trail threshold. */
1846 if (j == finger->trails_count)
1849 return finger_trail;
1854 * This is a test function, to print all the entries of finger table.
1857 test_finger_table_print()
1859 struct FingerInfo *finger;
1860 struct GNUNET_PeerIdentity print_peer;
1861 struct Trail *trail;
1866 FPRINTF (stderr,_("\nSUPU************ FINGER_TABLE"));
1867 for (i = 0; i < MAX_FINGERS; i++)
1869 finger = &finger_table[i];
1871 if (GNUNET_NO == finger->is_present)
1874 print_peer = finger->finger_identity;
1875 FPRINTF (stderr,_("\nSUPU %s, %s, %d, finger_table[%d] = %s, trails_count = %d"),
1876 __FILE__, __func__,__LINE__,i,GNUNET_i2s (&print_peer), finger->trails_count);
1879 for (j = 0; j < finger->trails_count; j++)
1881 trail = &finger->trail_list[j];
1882 FPRINTF (stderr,_("\nSUPU %s, %s, %d, trail_id[%d]=%s"),__FILE__, __func__,__LINE__,j, GNUNET_h2s(&trail->trail_id));
1883 struct Trail_Element *element;
1884 element = trail->trail_head;
1885 for (k = 0; k < trail->trail_length; k++)
1887 print_peer = element->peer;
1888 FPRINTF (stderr,_("\nSUPU %s, %s, %d,trail[%d] = %s "),__FILE__, __func__,__LINE__,k, GNUNET_i2s(&print_peer));
1889 element = element->next;
1897 * Compare FINGER entry with current successor. If finger's first friend of all
1898 * its trail is not congested and has not crossed trail threshold, then check
1899 * if finger peer identity is closer to final_destination_finger_value than
1900 * current_successor. If yes then update current_successor.
1901 * @param current_successor[in/out]
1904 static struct Closest_Peer *
1905 compare_finger_and_current_successor (struct Closest_Peer *current_closest_peer)
1907 struct FingerInfo *finger;
1908 struct FriendInfo *friend;
1909 struct GNUNET_PeerIdentity *closest_peer;
1910 struct Selected_Finger_Trail *finger_trail;
1913 /* Iterate over finger table. */
1914 for (i = 0; i < MAX_FINGERS; i++)
1916 finger = &finger_table[i];
1918 /* No valid entry at this index, go to next element.*/
1919 if (GNUNET_NO == finger->is_present)
1922 /* If my identity is same as current closest peer then don't consider me*/
1924 GNUNET_CRYPTO_cmp_peer_identity (&finger->finger_identity,
1925 ¤t_closest_peer->best_known_destination))
1928 /* If I am my own finger, then ignore this finger. */
1929 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&finger->finger_identity,
1933 /* If finger is a friend, then do nothing. As we have already checked
1934 * for each friend in compare_friend_and_current_successor(). */
1936 (friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
1937 &finger->finger_identity)))
1941 /* We have a finger which not a friend, not my identity */
1942 /* Choose one of the trail to reach to finger. */
1943 finger_trail = select_finger_trail (finger);
1945 /* In case no trail found, ignore this finger. */
1946 if (NULL == finger_trail)
1949 closest_peer = select_closest_peer (&finger->finger_identity,
1950 ¤t_closest_peer->best_known_destination,
1951 current_closest_peer->destination_finger_value,
1952 current_closest_peer->is_predecessor);
1954 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&finger->finger_identity,
1957 current_closest_peer->best_known_destination = finger->finger_identity;
1958 current_closest_peer->next_hop = finger_trail->friend.id;
1959 current_closest_peer->trail_id = finger_trail->trail_id;
1963 return current_closest_peer;
1968 * Compare friend entry with current successor.
1969 * If friend identity and current_successor is same, then do nothing.
1970 * If friend is not congested and has not crossed trail threshold, then check
1971 * if friend peer identity is closer to final_destination_finger_value than
1972 * current_successor. If yes then update current_successor.
1973 * @param cls closure
1974 * @param key current public key
1975 * @param value struct Closest_Peer
1976 * @return #GNUNET_YES if we should continue to iterate,
1977 * #GNUNET_NO if not.
1980 compare_friend_and_current_closest_peer (void *cls,
1981 const struct GNUNET_PeerIdentity *key,
1984 struct FriendInfo *friend = value;
1985 struct Closest_Peer *current_closest_peer = cls;
1986 struct GNUNET_PeerIdentity *closest_peer;
1988 /* If friend is either congested or has crossed threshold, then don't consider
1990 if (GNUNET_YES == is_friend_congested (friend))
1993 /* If current_closest_peer and friend identity are same, then do nothing.*/
1995 GNUNET_CRYPTO_cmp_peer_identity (&friend->id,
1996 ¤t_closest_peer->best_known_destination))
1999 closest_peer = select_closest_peer (&friend->id,
2000 ¤t_closest_peer->best_known_destination,
2001 current_closest_peer->destination_finger_value,
2002 current_closest_peer->is_predecessor);
2004 /* Is friend the closest successor? */
2005 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&friend->id, closest_peer))
2007 current_closest_peer->best_known_destination = friend->id;
2008 current_closest_peer->next_hop = friend->id;
2016 * Initialize current_successor to my_identity.
2017 * @param my_identity My peer identity
2018 * @return current_successor
2020 static struct Closest_Peer *
2021 init_current_successor (struct GNUNET_PeerIdentity my_identity,
2022 uint64_t destination_finger_value,
2023 unsigned int is_predecessor)
2025 struct Closest_Peer *current_closest_peer;
2027 current_closest_peer = GNUNET_new (struct Closest_Peer);
2028 memset (¤t_closest_peer->trail_id, 0, sizeof (current_closest_peer->trail_id));
2029 current_closest_peer->destination_finger_value = destination_finger_value;
2030 current_closest_peer->is_predecessor = is_predecessor;
2031 current_closest_peer->next_hop = my_identity;
2032 current_closest_peer->best_known_destination = my_identity;
2034 return current_closest_peer;
2039 * Find the successor for destination_finger_value among my_identity, all my
2040 * friend and all my fingers. Don't consider friends or fingers which are either
2041 * congested or have crossed the threshold.
2042 * NOTE: In case a friend is also a finger, then it is always chosen as friend
2044 * @param destination_finger_value Peer closest to this value will be the next successor.
2045 * @param local_best_known_destination[out] Updated to my_identity if I am the
2046 * final destination. Updated to friend
2047 * identity in case a friend is successor,
2048 * updated to finger in case finger is the
2050 * @param new_intermediate_trail_id[out] In case a finger is the
2051 * @a local_best_known_destination,
2052 * then it is the trail to reach it. Else
2054 * @param is_predecessor Are we looking for predecessor or finger?
2055 * @return Next hop to reach to local_best_known_destination. In case my_identity
2056 * or a friend is a local_best_known_destination, then
2057 * next_hop = local_best_known_destination. Else
2058 * next_hop is the first friend to reach to finger (local_best_known_destination)
2060 static struct GNUNET_PeerIdentity *
2061 find_successor (uint64_t destination_finger_value,
2062 struct GNUNET_PeerIdentity *local_best_known_destination,
2063 struct GNUNET_HashCode *new_intermediate_trail_id,
2064 unsigned int is_predecessor)
2066 struct Closest_Peer *current_closest_peer;
2067 struct GNUNET_PeerIdentity *next_hop;
2069 /* Initialize current_successor to my_identity. */
2070 current_closest_peer = init_current_successor (my_identity,
2071 destination_finger_value,
2074 /* Compare each friend entry with current_successor and update current_successor
2075 * with friend if its closest. */
2078 GNUNET_CONTAINER_multipeermap_iterate (friend_peermap,
2079 &compare_friend_and_current_closest_peer,
2080 current_closest_peer));
2082 /* Compare each finger entry with current_successor and update current_successor
2083 * with finger if its closest. */
2084 compare_finger_and_current_successor (current_closest_peer);
2086 *local_best_known_destination = current_closest_peer->best_known_destination;
2087 new_intermediate_trail_id = ¤t_closest_peer->trail_id;
2088 next_hop = GNUNET_new (struct GNUNET_PeerIdentity);
2089 *next_hop = current_closest_peer->next_hop;
2096 * Construct a Put message and send it to target_peer.
2097 * @param key Key for the content
2098 * @param block_type Type of the block
2099 * @param options Routing options
2100 * @param desired_replication_level Desired replication count
2101 * @param best_known_dest Peer to which this message should reach eventually,
2102 * as it is best known destination to me.
2103 * @param intermediate_trail_id Trail id in case
2104 * @param target_peer Peer to which this message will be forwarded.
2105 * @param hop_count Number of hops traversed so far.
2106 * @param put_path_length Total number of peers in @a put_path
2107 * @param put_path Number of peers traversed so far
2108 * @param expiration_time When does the content expire
2109 * @param data Content to store
2110 * @param data_size Size of content @a data in bytes
2113 GDS_NEIGHBOURS_send_put (const struct GNUNET_HashCode *key,
2114 enum GNUNET_BLOCK_Type block_type,
2115 enum GNUNET_DHT_RouteOption options,
2116 uint32_t desired_replication_level,
2117 struct GNUNET_PeerIdentity *best_known_dest,
2118 struct GNUNET_HashCode *intermediate_trail_id,
2119 struct GNUNET_PeerIdentity *target_peer,
2121 uint32_t put_path_length,
2122 struct GNUNET_PeerIdentity *put_path,
2123 struct GNUNET_TIME_Absolute expiration_time,
2124 const void *data, size_t data_size)
2126 struct PeerPutMessage *ppm;
2127 struct P2PPendingMessage *pending;
2128 struct FriendInfo *target_friend;
2129 struct GNUNET_PeerIdentity *pp;
2130 struct GNUNET_PeerIdentity local_best_known_dest;
2133 msize = put_path_length * sizeof (struct GNUNET_PeerIdentity) + data_size +
2134 sizeof (struct PeerPutMessage);
2136 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
2138 put_path_length = 0;
2139 msize = data_size + sizeof (struct PeerPutMessage);
2142 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
2148 /* This is the first call made from clients file. So, we should search for the
2150 if (NULL == target_peer)
2153 struct GNUNET_PeerIdentity *next_hop;
2155 memcpy (&key_value, key, sizeof (uint64_t));
2156 key_value = GNUNET_ntohll (key_value);
2158 next_hop = find_successor (key_value, &local_best_known_dest,
2159 intermediate_trail_id, GDS_FINGER_TYPE_NON_PREDECESSOR);
2160 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&local_best_known_dest, &my_identity))
2162 /* I am the destination but we have already done datacache_put in client file. */
2166 GNUNET_assert (NULL !=
2167 (target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop)));
2168 GNUNET_free (next_hop);
2172 GNUNET_assert (NULL !=
2174 GNUNET_CONTAINER_multipeermap_get (friend_peermap, target_peer)));
2176 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
2177 pending->timeout = expiration_time;
2178 ppm = (struct PeerPutMessage *) &pending[1];
2179 pending->msg = &ppm->header;
2180 ppm->header.size = htons (msize);
2181 ppm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_PUT);
2182 ppm->options = htonl (options);
2183 ppm->block_type = htonl (block_type);
2184 ppm->hop_count = htonl (hop_count + 1);
2185 ppm->desired_replication_level = htonl (desired_replication_level);
2186 ppm->put_path_length = htonl (put_path_length);
2187 ppm->expiration_time = GNUNET_TIME_absolute_hton (expiration_time);
2188 if (NULL == best_known_dest)
2189 ppm->best_known_destination = local_best_known_dest;
2191 ppm->best_known_destination = *best_known_dest;
2193 if (NULL == intermediate_trail_id)
2194 memset (&ppm->intermediate_trail_id, 0, sizeof (ppm->intermediate_trail_id));
2196 ppm->intermediate_trail_id = *intermediate_trail_id;
2197 pp = (struct GNUNET_PeerIdentity *) &ppm[1];
2198 if (put_path_length != 0)
2200 memcpy (pp, put_path,
2201 sizeof (struct GNUNET_PeerIdentity) * put_path_length);
2203 memcpy (&pp[put_path_length], data, data_size);
2205 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
2206 target_friend->pending_count++;
2207 process_friend_queue (target_friend);
2212 * Construct a Get message and send it to target_peer.
2213 * @param key Key for the content
2214 * @param block_type Type of the block
2215 * @param options Routing options
2216 * @param desired_replication_level Desired replication count
2217 * @param best_known_dest Peer which should get this message. Same as target peer
2218 * if best_known_dest is a friend else its a finger.
2219 * @param intermediate_trail_id Trail id to reach to @a best_known_dest
2220 * in case it is a finger else set to 0.
2221 * @param target_peer Peer to which this message will be forwarded.
2222 * @param hop_count Number of hops traversed so far.
2223 * @param data Content to store
2224 * @param data_size Size of content @a data in bytes
2225 * @param get_path_length Total number of peers in @a get_path
2226 * @param get_path Number of peers traversed so far
2229 GDS_NEIGHBOURS_send_get (const struct GNUNET_HashCode *key,
2230 enum GNUNET_BLOCK_Type block_type,
2231 enum GNUNET_DHT_RouteOption options,
2232 uint32_t desired_replication_level,
2233 const struct GNUNET_PeerIdentity *best_known_dest,
2234 struct GNUNET_HashCode *intermediate_trail_id,
2235 struct GNUNET_PeerIdentity *target_peer,
2237 uint32_t get_path_length,
2238 struct GNUNET_PeerIdentity *get_path)
2240 struct PeerGetMessage *pgm;
2241 struct P2PPendingMessage *pending;
2242 struct FriendInfo *target_friend;
2243 struct GNUNET_PeerIdentity local_best_known_dest;
2244 struct GNUNET_PeerIdentity *gp;
2247 msize = sizeof (struct PeerGetMessage) +
2248 (get_path_length * sizeof (struct GNUNET_PeerIdentity));
2250 /* In this case we don't make get_path_length = 0, as we need get path to
2251 * return the message back to querying client. */
2252 if (msize > GNUNET_SERVER_MAX_MESSAGE_SIZE)
2257 /* This is the first time we got request from our own client file. */
2258 if (NULL == target_peer)
2260 struct GNUNET_PeerIdentity *next_hop;
2263 memcpy (&key_value, key, sizeof (uint64_t));
2264 key_value = GNUNET_ntohll (key_value);
2266 /* Find the next destination to forward the packet. */
2267 next_hop = find_successor (key_value, &local_best_known_dest,
2268 intermediate_trail_id, GDS_FINGER_TYPE_NON_PREDECESSOR);
2270 /* I am the destination. I have the data. */
2271 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&my_identity,
2272 &local_best_known_dest))
2274 GDS_DATACACHE_handle_get (key,block_type, NULL, 0,
2275 NULL, 0, 1, &my_identity, NULL,&my_identity);
2281 GNUNET_assert (NULL !=
2283 GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop)));
2285 GNUNET_free (next_hop);
2289 local_best_known_dest = *best_known_dest;
2290 GNUNET_assert (NULL !=
2292 GNUNET_CONTAINER_multipeermap_get (friend_peermap, target_peer)));
2295 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
2296 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
2297 pending->importance = 0; /* FIXME */
2298 pgm = (struct PeerGetMessage *) &pending[1];
2299 pending->msg = &pgm->header;
2300 pgm->header.size = htons (msize);
2301 pgm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_GET);
2302 pgm->get_path_length = htonl (get_path_length);
2303 pgm->best_known_destination = local_best_known_dest;
2306 if (NULL == intermediate_trail_id)
2307 memset ((void *)&pgm->intermediate_trail_id, 0, sizeof (pgm->intermediate_trail_id));
2309 pgm->intermediate_trail_id = *intermediate_trail_id;
2310 pgm->hop_count = htonl (hop_count + 1);
2311 gp = (struct GNUNET_PeerIdentity *) &pgm[1];
2313 if (get_path_length != 0)
2315 memcpy (gp, get_path, get_path_length * sizeof (struct GNUNET_PeerIdentity));
2318 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
2319 target_friend->pending_count++;
2320 process_friend_queue (target_friend);
2325 * Send the get result to requesting client.
2326 * @param key Key of the requested data.
2327 * @param type Block type
2328 * @param target_peer Next peer to forward the message to.
2329 * @param source_peer Peer which has the data for the key.
2330 * @param put_path_length Number of peers in @a put_path
2331 * @param put_path Path taken to put the data at its stored location.
2332 * @param get_path_length Number of peers in @a get_path
2333 * @param get_path Path taken to reach to the location of the key.
2334 * @param expiration When will this result expire?
2335 * @param data Payload to store
2336 * @param data_size Size of the @a data
2339 GDS_NEIGHBOURS_send_get_result (const struct GNUNET_HashCode *key,
2340 enum GNUNET_BLOCK_Type type,
2341 const struct GNUNET_PeerIdentity *target_peer,
2342 const struct GNUNET_PeerIdentity *source_peer,
2343 unsigned int put_path_length,
2344 const struct GNUNET_PeerIdentity *put_path,
2345 unsigned int get_path_length,
2346 const struct GNUNET_PeerIdentity *get_path,
2347 struct GNUNET_TIME_Absolute expiration,
2348 const void *data, size_t data_size)
2350 struct PeerGetResultMessage *get_result;
2351 struct GNUNET_PeerIdentity *paths;
2352 struct P2PPendingMessage *pending;
2353 struct FriendInfo *target_friend;
2354 int current_path_index;
2357 msize = (put_path_length + get_path_length )* sizeof (struct GNUNET_PeerIdentity) +
2359 sizeof (struct PeerGetResultMessage);
2361 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
2367 current_path_index = 0;
2368 if(get_path_length > 0)
2370 current_path_index = search_my_index(get_path, get_path_length);
2371 if (-1 == current_path_index)
2377 if (0 == current_path_index)
2379 GDS_CLIENTS_handle_reply (expiration, key, get_path_length,
2380 get_path, put_path_length,
2381 put_path, type, data_size, data);
2385 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
2386 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
2387 pending->importance = 0;
2388 get_result = (struct PeerGetResultMessage *)&pending[1];
2389 pending->msg = &get_result->header;
2390 get_result->header.size = htons (msize);
2391 get_result->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_GET_RESULT);
2392 get_result->key = *key;
2393 get_result->querying_peer = *source_peer;
2394 get_result->expiration_time = expiration;
2395 get_result->get_path_length = htonl (get_path_length);
2396 get_result->put_path_length = htonl (put_path_length);
2397 paths = (struct GNUNET_PeerIdentity *)&get_result[1];
2398 memcpy (paths, put_path,
2399 put_path_length * sizeof (struct GNUNET_PeerIdentity));
2400 memcpy (&paths[put_path_length], get_path,
2401 get_path_length * sizeof (struct GNUNET_PeerIdentity));
2402 memcpy (&paths[put_path_length + get_path_length], data, data_size);
2404 GNUNET_assert (NULL !=
2406 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2407 &get_path[current_path_index - 1])));
2408 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
2409 target_friend->pending_count++;
2410 process_friend_queue (target_friend);
2415 * Randomly choose one of your friends (which is not congested and have not crossed
2416 * trail threshold) from the friends_peer map
2417 * @return Friend Randomly chosen friend.
2418 * NULL in case friend peermap is empty, or all the friends are either
2419 * congested or have crossed trail threshold.
2421 static struct FriendInfo *
2422 select_random_friend ()
2424 unsigned int current_size;
2427 struct GNUNET_CONTAINER_MultiPeerMapIterator *iter;
2428 struct GNUNET_PeerIdentity key_ret;
2429 struct FriendInfo *friend;
2431 current_size = GNUNET_CONTAINER_multipeermap_size (friend_peermap);
2434 if (0 == current_size)
2437 index = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, current_size);
2438 iter = GNUNET_CONTAINER_multipeermap_iterator_create (friend_peermap);
2440 /* Iterate till you don't reach to index. */
2441 for (j = 0; j < index ; j++)
2442 GNUNET_assert (GNUNET_YES ==
2443 GNUNET_CONTAINER_multipeermap_iterator_next (iter, NULL, NULL));
2446 /* Reset the index in friend peermap to 0 as we reached to the end. */
2447 if (j == current_size)
2450 GNUNET_CONTAINER_multipeermap_iterator_destroy (iter);
2451 iter = GNUNET_CONTAINER_multipeermap_iterator_create (friend_peermap);
2455 /* Get the friend stored at the index, j*/
2456 GNUNET_assert (GNUNET_YES ==
2457 GNUNET_CONTAINER_multipeermap_iterator_next (iter,
2459 (const void **)&friend));
2461 /* This friend is not congested and has not crossed trail threshold. */
2462 if ((TRAILS_THROUGH_FRIEND_THRESHOLD > friend->trails_count) &&
2463 (0 == GNUNET_TIME_absolute_get_remaining (friend->congestion_timestamp).rel_value_us))
2469 } while (j != index);
2471 GNUNET_CONTAINER_multipeermap_iterator_destroy (iter);
2477 * Compute 64 bit value of finger_identity corresponding to a finger index using
2480 * n.finger[i] = n + pow (2,i),
2482 * n.finger[i] = n - 1, where
2485 * n.finger[i] = 64 bit finger value
2486 * @param finger_index Index corresponding to which we calculate 64 bit value.
2487 * @return 64 bit value.
2490 compute_finger_identity_value (unsigned int finger_index)
2494 memcpy (&my_id64, &my_identity, sizeof (uint64_t));
2495 my_id64 = GNUNET_ntohll (my_id64);
2497 /* Are we looking for immediate predecessor? */
2498 if (PREDECESSOR_FINGER_ID == finger_index)
2499 return (my_id64 -1);
2501 return (my_id64 + (unsigned long) pow (2, finger_index));
2506 * Choose a random friend. Start looking for the trail to reach to
2507 * finger identity corresponding to current_search_finger_index through
2508 * this random friend.
2510 * @param cls closure for this task
2511 * @param tc the context under which the task is running
2514 send_find_finger_trail_message (void *cls,
2515 const struct GNUNET_SCHEDULER_TaskContext *tc)
2517 struct FriendInfo *target_friend;
2518 struct GNUNET_TIME_Relative next_send_time;
2519 struct GNUNET_HashCode trail_id;
2520 unsigned int is_predecessor;
2521 uint64_t finger_id_value;
2523 /* Schedule another send_find_finger_trail_message task. */
2524 next_send_time.rel_value_us =
2525 DHT_FIND_FINGER_TRAIL_INTERVAL.rel_value_us +
2526 GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK,
2527 DHT_FIND_FINGER_TRAIL_INTERVAL.rel_value_us);
2528 find_finger_trail_task =
2529 GNUNET_SCHEDULER_add_delayed (next_send_time, &send_find_finger_trail_message,
2532 /* No space in my routing table. (Source and destination peers also store entries
2533 * in their routing table). */
2534 if (GNUNET_YES == GDS_ROUTING_threshold_reached())
2537 target_friend = select_random_friend ();
2538 if (NULL == target_friend)
2543 finger_id_value = compute_finger_identity_value (current_search_finger_index);
2544 if (PREDECESSOR_FINGER_ID == current_search_finger_index)
2549 /* Generate a unique trail id for trail we are trying to setup. */
2550 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_STRONG,
2551 &trail_id, sizeof (trail_id));
2552 GDS_NEIGHBOURS_send_trail_setup (my_identity, finger_id_value,
2553 target_friend->id, target_friend, 0, NULL,
2554 is_predecessor, trail_id, NULL);
2559 * In case there are already maximum number of possible trails to reach to a
2560 * finger, then check if the new trail's length is lesser than any of the
2562 * If yes then replace that old trail by new trail.
2564 * Note: Here we are taking length as a parameter to choose the best possible
2565 * trail, but there could be other parameters also like:
2566 * 1. duration of existence of a trail - older the better.
2567 * 2. if the new trail is completely disjoint than the
2568 * other trails, then may be choosing it is better.
2570 * @param existing_finger
2571 * @param new_finger_trail
2572 * @param new_finger_trail_length
2573 * @param new_finger_trail_id
2576 select_and_replace_trail (struct FingerInfo *existing_finger,
2577 const struct GNUNET_PeerIdentity *new_trail,
2578 unsigned int new_trail_length,
2579 struct GNUNET_HashCode new_trail_id)
2581 struct Trail *trail_list_iterator;
2582 unsigned int largest_trail_length;
2583 unsigned int largest_trail_index;
2584 struct Trail_Element *trail_element;
2587 largest_trail_length = new_trail_length;
2588 largest_trail_index = MAXIMUM_TRAILS_PER_FINGER + 1;
2590 GNUNET_assert (MAXIMUM_TRAILS_PER_FINGER == existing_finger->trails_count);
2592 for (i = 0; i < existing_finger->trails_count; i++)
2594 trail_list_iterator = &existing_finger->trail_list[i];
2595 if (trail_list_iterator->trail_length > largest_trail_length)
2597 largest_trail_length = trail_list_iterator->trail_length;
2598 largest_trail_index = i;
2602 /* New trail is not better than existing ones. Send trail teardown. */
2603 if (largest_trail_index == (MAXIMUM_TRAILS_PER_FINGER + 1))
2605 struct GNUNET_PeerIdentity next_hop;
2607 memcpy (&next_hop, &new_trail[0], sizeof(struct GNUNET_PeerIdentity));
2608 GDS_ROUTING_remove_trail (new_trail_id);
2609 GDS_NEIGHBOURS_send_trail_teardown (new_trail_id,
2610 GDS_ROUTING_SRC_TO_DEST,
2615 /* Send trail teardown message across the replaced trail. */
2616 struct Trail *replace_trail = &existing_finger->trail_list[largest_trail_index];
2617 GNUNET_assert (GNUNET_YES == GDS_ROUTING_remove_trail (replace_trail->trail_id));
2618 GDS_NEIGHBOURS_send_trail_teardown (replace_trail->trail_id,
2619 GDS_ROUTING_SRC_TO_DEST,
2620 replace_trail->trail_head->peer);
2621 /* Free the trail. */
2622 while (NULL != (trail_element = replace_trail->trail_head))
2624 GNUNET_CONTAINER_DLL_remove (replace_trail->trail_head,
2625 replace_trail->trail_tail, trail_element);
2626 GNUNET_free_non_null (trail_element);
2629 /* Add new trial at that location. */
2630 replace_trail->is_present = GNUNET_YES;
2631 replace_trail->trail_length = new_trail_length;
2632 replace_trail->trail_id = new_trail_id;
2633 //FIXME: Do we need to add pointers for head and tail.
2635 while (i < new_trail_length)
2637 struct Trail_Element *element = GNUNET_new (struct Trail_Element);
2638 element->peer = new_trail[i];
2640 GNUNET_CONTAINER_DLL_insert_tail (replace_trail->trail_head,
2641 replace_trail->trail_tail,
2648 * Check if the new trail to reach to finger is unique or do we already have
2649 * such a trail present for finger.
2650 * @param existing_finger Finger identity
2651 * @param new_trail New trail to reach @a existing_finger
2652 * @param trail_length Total number of peers in new_trail.
2653 * @return #GNUNET_YES if the new trail is unique
2654 * #GNUNET_NO if same trail is already present.
2657 is_new_trail_unique (struct FingerInfo *existing_finger,
2658 const struct GNUNET_PeerIdentity *new_trail,
2659 unsigned int trail_length)
2661 struct Trail *trail_list_iterator;
2662 struct Trail_Element *trail_element;
2665 int trail_unique = GNUNET_NO;
2667 GNUNET_assert (existing_finger->trails_count > 0);
2669 /* Iterate over list of trails. */
2670 for (i = 0; i < existing_finger->trails_count; i++)
2672 trail_list_iterator = &existing_finger->trail_list[i];
2673 GNUNET_assert (GNUNET_YES == trail_list_iterator->is_present);
2675 /* New trail and existing trail length are not same. */
2676 if (trail_list_iterator->trail_length != trail_length)
2678 trail_unique = GNUNET_YES;
2682 trail_element = trail_list_iterator->trail_head;
2683 for (j = 0; j < trail_list_iterator->trail_length; j++)
2685 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&new_trail[j],
2686 &trail_element->peer))
2688 trail_unique = GNUNET_YES;
2691 trail_element = trail_element->next;
2694 trail_unique = GNUNET_NO;
2697 return trail_unique;
2702 * Add a new trail to existing finger. This function is called only when finger
2703 * is not my own identity or a friend.
2704 * @param existing_finger Finger
2705 * @param new_finger_trail New trail from me to finger, NOT including endpoints
2706 * @param new_finger_trail_length Total number of peers in @a new_finger_trail
2707 * @param new_finger_trail_id Unique identifier of the trail.
2710 add_new_trail (struct FingerInfo *existing_finger,
2711 const struct GNUNET_PeerIdentity *new_trail,
2712 unsigned int new_trail_length,
2713 struct GNUNET_HashCode new_trail_id)
2715 struct Trail *trail_list_iterator;
2716 struct FriendInfo *first_friend;
2719 if (GNUNET_NO == is_new_trail_unique (existing_finger, new_trail,
2725 trail_list_iterator = &existing_finger->trail_list[existing_finger->trails_count];
2726 GNUNET_assert (GNUNET_NO == trail_list_iterator->is_present);
2727 trail_list_iterator->trail_id = new_trail_id;
2728 trail_list_iterator->trail_length = new_trail_length;
2729 existing_finger->trails_count++;
2730 trail_list_iterator->is_present = GNUNET_YES;
2732 /* If finger is a friend then we never call this function. */
2733 GNUNET_assert (new_trail_length > 0);
2735 first_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2737 first_friend->trails_count++;
2739 for (i = 0; i < new_trail_length; i++)
2741 struct Trail_Element *element;
2742 element = GNUNET_new (struct Trail_Element);
2744 element->peer = new_trail[i];
2745 GNUNET_CONTAINER_DLL_insert_tail (trail_list_iterator->trail_head,
2746 trail_list_iterator->trail_tail,
2749 /* Do we need to add trail head and trail tail in the trail list itearator.*/
2755 * FIXME Check if this function is called for opposite direction if yes then
2756 * take it as parameter.
2757 * Get the next hop to send trail teardown message from routing table and
2758 * then delete the entry from routing table. Send trail teardown message for a
2759 * specific trail of a finger.
2760 * @param finger Finger whose trail is to be removed.
2761 * @param trail List of peers in trail from me to a finger, NOT including
2765 send_trail_teardown (struct FingerInfo *finger,
2766 struct Trail *trail)
2768 struct FriendInfo *friend;
2769 struct GNUNET_PeerIdentity *next_hop;
2771 GNUNET_assert (NULL !=
2772 (next_hop = GDS_ROUTING_get_next_hop (trail->trail_id,
2773 GDS_ROUTING_SRC_TO_DEST)));
2774 if (trail->trail_length > 0)
2775 GNUNET_assert (NULL != (friend =
2776 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2777 &trail->trail_head->peer)));
2780 GNUNET_assert (NULL != (friend =
2781 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2782 &finger->finger_identity)));
2784 GNUNET_assert (0 == GNUNET_CRYPTO_cmp_peer_identity (next_hop, &friend->id));
2785 GNUNET_assert (GNUNET_YES == GDS_ROUTING_remove_trail (trail->trail_id));
2786 friend->trails_count--;
2787 GDS_NEIGHBOURS_send_trail_teardown (trail->trail_id,
2788 GDS_ROUTING_SRC_TO_DEST,
2794 * Send trail teardown message across all the trails to reach to finger.
2795 * @param finger Finger whose all the trail should be freed.
2798 send_all_finger_trails_teardown (struct FingerInfo *finger)
2802 for (i = 0; i < finger->trails_count; i++)
2804 struct Trail *trail;
2806 trail = &finger->trail_list[i];
2807 GNUNET_assert (trail->is_present == GNUNET_YES);
2808 send_trail_teardown (finger, trail);
2814 * Free a specific trail
2815 * @param trail List of peers to be freed.
2818 free_trail (struct Trail *trail)
2820 struct Trail_Element *trail_element;
2822 while (NULL != (trail_element = trail->trail_head))
2824 GNUNET_CONTAINER_DLL_remove (trail->trail_head,
2827 GNUNET_free_non_null (trail_element);
2829 trail->trail_head = NULL;
2830 trail->trail_tail = NULL;
2835 * Free finger and its trail.
2836 * @param finger Finger to be freed.
2839 free_finger (struct FingerInfo *finger, unsigned int finger_table_index)
2841 struct Trail *trail;
2844 /* Free all the trails to reach to finger */
2845 for (i = 0; i < finger->trails_count; i++)
2847 trail = &finger->trail_list[i];
2848 //FIXME: Check if there are any missing entry in this list because of
2849 // how we insert. If not then no need of this check.
2850 if (GNUNET_NO == trail->is_present)
2853 if (trail->trail_length > 0)
2856 trail->is_present = GNUNET_NO;
2860 finger->is_present = GNUNET_NO;
2861 memset ((void *)&finger_table[finger_table_index], 0, sizeof (finger_table[finger_table_index]));
2866 * FIXME: ensure that you are not adding any trail to reach to a friend which
2867 * is a finger. Also decide on should you increment trails count of a friend
2868 * which is also a finger.
2869 * Add a new entry in finger table at finger_table_index.
2870 * In case finger identity is me or a friend, then don't add a trail. NOTE
2871 * trail length to reach to a finger can be 0 only if the finger is a friend
2873 * In case a finger is a friend, then increment the trails count of the friend.
2874 * @param finger_identity Peer Identity of new finger
2875 * @param finger_trail Trail to reach from me to finger (excluding both end points).
2876 * @param finger_trail_length Total number of peers in @a finger_trail.
2877 * @param trail_id Unique identifier of the trail.
2878 * @param finger_table_index Index in finger table.
2881 add_new_finger (struct GNUNET_PeerIdentity finger_identity,
2882 const struct GNUNET_PeerIdentity *finger_trail,
2883 unsigned int finger_trail_length,
2884 struct GNUNET_HashCode trail_id,
2885 unsigned int finger_table_index)
2887 struct FingerInfo *new_entry;
2888 struct FriendInfo *first_trail_hop;
2889 struct Trail *trail;
2892 new_entry = GNUNET_new (struct FingerInfo);
2893 new_entry->finger_identity = finger_identity;
2894 new_entry->finger_table_index = finger_table_index;
2895 new_entry->is_present = GNUNET_YES;
2897 /* If the new entry is my own identity. */
2898 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &finger_identity))
2900 new_entry->trails_count = 0;
2901 finger_table[finger_table_index] = *new_entry;
2905 /* If finger is a friend, then we don't actually have a trail.
2906 * Just a trail id */
2907 if (NULL != GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2910 new_entry->trail_list[0].trail_id = trail_id;
2911 new_entry->trails_count = 1;
2912 new_entry->trail_list[0].is_present = GNUNET_YES;
2913 new_entry->trail_list[0].trail_length = 0;
2914 new_entry->trail_list[0].trail_head = NULL;
2915 new_entry->trail_list[0].trail_tail = NULL;
2916 finger_table[finger_table_index] = *new_entry;
2917 GNUNET_assert (NULL !=
2919 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2920 &finger_identity)));
2921 first_trail_hop->trails_count++;
2925 /* finger trail length can be 0 only in case if finger is my identity or
2926 finger is friend. We should never reach here. */
2927 GNUNET_assert (finger_trail_length > 0);
2929 GNUNET_assert (NULL !=
2931 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2932 &finger_trail[0])));
2933 new_entry->trails_count = 1;
2934 first_trail_hop->trails_count++;
2936 /* Copy the finger trail into trail. */
2937 trail = GNUNET_new (struct Trail);
2938 while (i < finger_trail_length)
2940 struct Trail_Element *element = GNUNET_new (struct Trail_Element);
2942 element->next = NULL;
2943 element->prev = NULL;
2944 element->peer = finger_trail[i];
2945 GNUNET_CONTAINER_DLL_insert_tail (trail->trail_head,
2951 /* Add trail to trail list. */
2952 new_entry->trail_list[0].trail_head = trail->trail_head;
2953 new_entry->trail_list[0].trail_tail = trail->trail_tail;
2954 new_entry->trail_list[0].trail_length = finger_trail_length;
2955 new_entry->trail_list[0].trail_id = trail_id;
2956 new_entry->trail_list[0].is_present = GNUNET_YES;
2957 finger_table[finger_table_index] = *new_entry;
2958 GNUNET_free (new_entry);
2959 GNUNET_free (trail);
2965 * Scan the trail to check if there is any other friend in the trail other than
2966 * first hop. If yes then shortcut the trail, send trail compression message to
2967 * peers which are no longer part of trail and send back the updated trail
2968 * and trail_length to calling function.
2969 * @param finger_identity Finger whose trail we will scan.
2970 * @param finger_trail [in, out] Trail to reach from source to finger,
2971 * @param finger_trail_length Total number of peers in original finger_trail.
2972 * @param finger_trail_id Unique identifier of the finger trail.
2973 * @return updated trail length in case we shortcut the trail, else original
2976 static struct GNUNET_PeerIdentity *
2977 scan_and_compress_trail (struct GNUNET_PeerIdentity finger_identity,
2978 const struct GNUNET_PeerIdentity *trail,
2979 unsigned int trail_length,
2980 struct GNUNET_HashCode trail_id,
2981 int *new_trail_length)
2983 struct FriendInfo *target_friend;
2984 struct GNUNET_PeerIdentity *new_trail;
2987 /* If I am my own finger identity, then we set trail_length = 0.
2988 Note: Here we don't send trail compression message, as no peer in its
2989 trail added an entry in its routing table.*/
2990 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &finger_identity))
2992 *new_trail_length = 0;
2996 /* If finger identity is a friend. */
2997 if (NULL != GNUNET_CONTAINER_multipeermap_get (friend_peermap, &finger_identity))
2999 *new_trail_length = 0;
3001 /* If there is trail to reach this finger/friend */
3002 if (trail_length > 0)
3004 GNUNET_assert (NULL !=
3006 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
3009 /* Before you send a trail compression, get the routing entry
3010 from you routing table. update the fields in routing table
3011 to update your next hop to finger identity. */
3012 GDS_ROUTING_update_trail_next_hop (trail_id, finger_identity);
3013 GDS_NEIGHBOURS_send_trail_compression (my_identity,
3014 trail_id, finger_identity,
3020 /* For other cases, when its neither a friend nor my own identity.*/
3021 for (i = trail_length - 1; i > 0; i--)
3023 /* If the element at this index in trail is a friend. */
3024 if (NULL != GNUNET_CONTAINER_multipeermap_get (friend_peermap, &trail[i]))
3026 struct FriendInfo *target_friend;
3029 GNUNET_assert (NULL !=
3031 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
3033 GNUNET_assert (NULL !=
3034 (GNUNET_CONTAINER_multipeermap_get (friend_peermap,
3036 GDS_ROUTING_update_trail_next_hop (trail_id, trail[i]);
3037 GDS_NEIGHBOURS_send_trail_compression (my_identity,
3042 /* Copy the trail from index i to index (trail_length -1) into a new trail
3043 * and update new trail length */
3044 new_trail = GNUNET_malloc (sizeof (struct GNUNET_PeerIdentity) * i);
3045 while (i < trail_length)
3047 memcpy (&new_trail[j], &trail[i], sizeof(struct GNUNET_PeerIdentity));
3051 *new_trail_length = j+1;
3056 /* If we did not compress the trail, return the original trail back.*/
3057 new_trail = GNUNET_malloc (sizeof (struct GNUNET_PeerIdentity) * trail_length);
3058 *new_trail_length = trail_length;
3059 memcpy (new_trail, trail, trail_length * sizeof (struct GNUNET_PeerIdentity));
3065 * Send verify successor message to your current successor over the shortest
3067 * @param successor Current successor.
3070 send_verify_successor_message (struct FingerInfo *successor)
3073 * FIXME: should we send a verify successor message across all the trails
3074 * in case we send through all friends. It complicates the logic, don't
3075 * do it at the moment. Write it as optimization and do it later.
3076 * 1. Here we can have 3 types of fingers
3077 * --> my own identity
3078 * Assumption that the calling function will not send request for
3079 * such successor. Move the logic here.
3080 * --> friend is a finger
3081 * Need to verify if we keep the trails count for a friend. In case of
3082 * friend there is no trail to reach to that friend, so
3083 * 1. no entry in routing table
3085 * 3. no trails count
3086 * 4. but do we increment the count of trails through the friend?
3087 * Trails count is used only to keep a limit on number of trails
3088 * that a friend should be part of. No need to increment the trails
3089 * count for a friend which is a finegr also. so, if finger = friend
3090 * then don't increment the trails count. But if the same friend
3091 * is the first friend to reach to some other finger then increment
3092 * the trails count. Not sure if this design is correct need to verify
3096 struct FriendInfo *target_friend;
3097 struct GNUNET_HashCode trail_id;
3100 for (i = 0; i < successor->trails_count; i++)
3102 struct Trail *trail;
3103 struct Trail_Element *element;
3104 unsigned int trail_length;
3107 trail = &successor->trail_list[i];
3109 /* No trail stored at this index. */
3110 if (GNUNET_YES == trail->is_present)
3113 trail_id = trail->trail_id;
3114 trail_length = trail->trail_length;
3116 /* Copy the trail into peer list. */
3117 element = trail->trail_head;
3118 struct GNUNET_PeerIdentity peer_list[trail_length];
3119 while (j < trail_length)
3121 peer_list[j] = element->peer;
3122 element = element->next;
3126 if (trail_length > 0)
3127 GNUNET_assert (NULL != (target_friend =
3128 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
3131 GNUNET_assert (NULL != (target_friend =
3132 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
3133 &successor->finger_identity)));
3134 GDS_NEIGHBOURS_send_verify_successor_message (my_identity,
3135 successor->finger_identity,
3136 trail_id, peer_list, trail_length,
3144 * Update the current search finger index.
3147 update_current_search_finger_index (struct GNUNET_PeerIdentity finger_identity,
3148 unsigned int finger_table_index)
3150 struct FingerInfo *successor;
3152 if (finger_table_index != current_search_finger_index)
3155 successor = &finger_table[0];
3156 if (GNUNET_NO == successor->is_present)
3159 /* We were looking for immediate successor. */
3160 if (0 == current_search_finger_index)
3162 /* Start looking for immediate predecessor. */
3163 current_search_finger_index = PREDECESSOR_FINGER_ID;
3165 /* If I am not my own successor, then send a verify successor message. */
3166 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &finger_identity))
3168 send_verify_successor_message (successor);
3173 current_search_finger_index = current_search_finger_index - 1;
3179 * Calculate finger_table_index from initial 64 bit finger identity value that
3180 * we send in trail setup message.
3181 * @param ultimate_destination_finger_value Value that we calculated from our
3182 * identity and finger_table_index.
3183 * @param is_predecessor Is the entry for predecessor or not?
3184 * @return finger_table_index Value between 0 <= finger_table_index <= 64
3185 * finger_table_index > PREDECESSOR_FINGER_ID ,
3186 * if no valid finger_table_index is found.
3189 get_finger_table_index (uint64_t ultimate_destination_finger_value,
3190 unsigned int is_predecessor)
3194 unsigned int finger_table_index;
3196 memcpy (&my_id64, &my_identity, sizeof (uint64_t));
3197 my_id64 = GNUNET_ntohll (my_id64);
3199 /* Is this a predecessor finger? */
3200 if (1 == is_predecessor)
3202 diff = my_id64 - ultimate_destination_finger_value;
3204 finger_table_index = PREDECESSOR_FINGER_ID;
3206 finger_table_index = PREDECESSOR_FINGER_ID + 1; //error value
3211 diff = ultimate_destination_finger_value - my_id64;
3212 finger_table_index = (log10 (diff))/(log10 (2));
3215 return finger_table_index;
3220 * Remove finger and its associated data structures from finger table.
3221 * @param finger Finger to be removed.
3224 remove_existing_finger (struct FingerInfo *existing_finger, unsigned int finger_table_index)
3226 struct FingerInfo *finger;
3228 finger = &finger_table[finger_table_index];
3229 GNUNET_assert (GNUNET_YES == finger->is_present);
3231 /* If I am my own finger, then we have no trails. */
3232 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&finger->finger_identity,
3235 finger->is_present = GNUNET_NO;
3236 memset ((void *)&finger_table[finger_table_index], 0, sizeof (finger_table[finger_table_index]));
3240 /* For all other fingers, send trail teardown across all the trails to reach
3241 finger, and free the finger. */
3242 send_all_finger_trails_teardown (finger);
3243 free_finger (finger, finger_table_index);
3249 * This is a test function to print all the entries of friend table.
3252 test_friend_peermap_print ()
3254 struct FriendInfo *friend;
3255 struct GNUNET_CONTAINER_MultiPeerMapIterator *friend_iter;
3256 struct GNUNET_PeerIdentity print_peer;
3257 struct GNUNET_PeerIdentity key_ret;
3260 friend_iter = GNUNET_CONTAINER_multipeermap_iterator_create (friend_peermap);
3262 for (i = 0; i < GNUNET_CONTAINER_multipeermap_size (friend_peermap); i++)
3264 if(GNUNET_YES == GNUNET_CONTAINER_multipeermap_iterator_next (friend_iter,
3266 (const void **)&friend))
3268 memcpy (&print_peer, &key_ret, sizeof (struct GNUNET_PeerIdentity));
3269 FPRINTF (stderr,_("\nSUPU %s, %s, %d, friend = %s, friend->trails_count = %d"),
3270 __FILE__, __func__,__LINE__, GNUNET_i2s(&print_peer), friend->trails_count);
3277 * Check if there is already an entry in finger_table at finger_table_index.
3278 * We get the finger_table_index from 64bit finger value we got from the network.
3279 * -- If yes, then select the closest finger.
3280 * -- If new and existing finger are same, then check if you can store more
3282 * -- If yes then add trail, else keep the best trails to reach to the
3284 * -- If the new finger is closest, remove the existing entry, send trail
3285 * teardown message across all the trails to reach the existing entry.
3286 * Add the new finger.
3287 * -- If new and existing finger are different, and existing finger is closest
3289 * -- Update current_search_finger_index.
3290 * @param finger_identity Peer Identity of new finger
3291 * @param finger_trail Trail to reach the new finger
3292 * @param finger_trail_length Total number of peers in @a new_finger_trail.
3293 * @param is_predecessor Is this entry for predecessor in finger_table?
3294 * @param finger_value 64 bit value of finger identity that we got from network.
3295 * @param finger_trail_id Unique identifier of @finger_trail.
3298 finger_table_add (struct GNUNET_PeerIdentity finger_identity,
3299 const struct GNUNET_PeerIdentity *finger_trail,
3300 unsigned int finger_trail_length,
3301 unsigned int is_predecessor,
3302 uint64_t finger_value,
3303 struct GNUNET_HashCode finger_trail_id)
3305 struct FingerInfo *existing_finger;
3306 struct GNUNET_PeerIdentity *closest_peer;
3307 struct GNUNET_PeerIdentity *updated_trail;
3308 struct FingerInfo *successor;
3309 int updated_finger_trail_length;
3310 unsigned int finger_table_index;
3311 //GDS_ROUTING_test_print();
3313 //test_friend_peermap_print();
3314 //test_finger_table_print();
3317 /* Get the finger_table_index corresponding to finger_value we got from network.*/
3318 finger_table_index = get_finger_table_index (finger_value, is_predecessor);
3320 /* Invalid finger_table_index. */
3321 if ((finger_table_index > PREDECESSOR_FINGER_ID))
3323 GNUNET_break_op (0);
3327 /* If the new entry for any finger table index other than successor or predecessor
3328 * is same as successor then don't add it in finger table,
3329 * reset the current search finger index and exit. */
3330 if ((0 != finger_table_index) &&
3331 (PREDECESSOR_FINGER_ID != finger_table_index) &&
3332 (finger_table_index == current_search_finger_index)) //FIXME; why do I check this cond?
3334 successor = &finger_table[0];
3335 GNUNET_assert (GNUNET_YES == successor->is_present);
3336 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&finger_identity,
3337 &successor->finger_identity))
3339 current_search_finger_index = 0;
3344 existing_finger = &finger_table[finger_table_index];
3346 /* Shorten the trail if possible. */
3347 updated_finger_trail_length = finger_trail_length;
3349 scan_and_compress_trail (finger_identity, finger_trail,
3350 finger_trail_length, finger_trail_id,
3351 &updated_finger_trail_length);
3353 /* No entry present in finger_table for given finger map index. */
3354 if (GNUNET_NO == existing_finger->is_present)
3356 add_new_finger (finger_identity, updated_trail,
3357 updated_finger_trail_length,
3358 finger_trail_id, finger_table_index);
3359 update_current_search_finger_index (finger_identity, finger_table_index);
3360 GNUNET_free_non_null (updated_trail);
3365 /* If existing entry and finger identity are not same. */
3366 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&(existing_finger->finger_identity),
3369 closest_peer = select_closest_peer (&existing_finger->finger_identity,
3374 /* If the new finger is the closest peer. */
3375 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&finger_identity, closest_peer))
3377 remove_existing_finger (existing_finger, finger_table_index);
3378 add_new_finger (finger_identity, updated_trail, updated_finger_trail_length,
3379 finger_trail_id, finger_table_index);
3384 /* If both new and existing entry are same as my_identity, then do nothing. */
3385 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&(existing_finger->finger_identity),
3388 GNUNET_free_non_null (updated_trail);
3391 /* If the existing finger is not a friend. */
3393 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
3394 &existing_finger->finger_identity))
3396 /* If there is space to store more trails. */
3397 if (existing_finger->trails_count < MAXIMUM_TRAILS_PER_FINGER)
3398 add_new_trail (existing_finger, updated_trail,
3399 finger_trail_length, finger_trail_id);
3401 select_and_replace_trail (existing_finger, updated_trail,
3402 finger_trail_length, finger_trail_id);
3405 update_current_search_finger_index (finger_identity, finger_table_index);
3406 GNUNET_free_non_null (updated_trail);
3412 * Core handler for P2P put messages.
3413 * @param cls closure
3414 * @param peer sender of the request
3415 * @param message message
3416 * @return #GNUNET_OK to keep the connection open,
3417 * #GNUNET_SYSERR to close it (signal serious error)
3420 handle_dht_p2p_put (void *cls, const struct GNUNET_PeerIdentity *peer,
3421 const struct GNUNET_MessageHeader *message)
3423 struct PeerPutMessage *put;
3424 struct GNUNET_PeerIdentity *put_path;
3425 struct GNUNET_HashCode test_key;
3426 enum GNUNET_DHT_RouteOption options;
3427 struct GNUNET_PeerIdentity best_known_dest;
3428 struct GNUNET_HashCode intermediate_trail_id;
3429 struct GNUNET_PeerIdentity *next_hop;
3433 size_t payload_size;
3436 msize = ntohs (message->size);
3437 if (msize < sizeof (struct PeerPutMessage))
3439 GNUNET_break_op (0);
3443 put = (struct PeerPutMessage *) message;
3444 putlen = ntohl (put->put_path_length);
3447 sizeof (struct PeerPutMessage) +
3448 putlen * sizeof (struct GNUNET_PeerIdentity)) ||
3450 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)))
3452 GNUNET_break_op (0);
3456 best_known_dest = put->best_known_destination;
3457 put_path = (struct GNUNET_PeerIdentity *) &put[1];
3458 payload = &put_path[putlen];
3459 options = ntohl (put->options);
3460 intermediate_trail_id = put->intermediate_trail_id;
3462 payload_size = msize - (sizeof (struct PeerPutMessage) +
3463 putlen * sizeof (struct GNUNET_PeerIdentity));
3465 switch (GNUNET_BLOCK_get_key (GDS_block_context, ntohl (put->block_type),
3466 payload, payload_size, &test_key))
3469 if (0 != memcmp (&test_key, &put->key, sizeof (struct GNUNET_HashCode)))
3471 char *put_s = GNUNET_strdup (GNUNET_h2s_full (&put->key));
3472 GNUNET_break_op (0);
3473 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3474 "PUT with key `%s' for block with key %s\n",
3475 put_s, GNUNET_h2s_full (&test_key));
3476 GNUNET_free (put_s);
3481 GNUNET_break_op (0);
3484 /* cannot verify, good luck */
3488 if (ntohl (put->block_type) == GNUNET_BLOCK_TYPE_REGEX) /* FIXME: do for all tpyes */
3490 switch (GNUNET_BLOCK_evaluate (GDS_block_context,
3491 ntohl (put->block_type),
3493 NULL, 0, /* bloom filer */
3494 NULL, 0, /* xquery */
3495 payload, payload_size))
3497 case GNUNET_BLOCK_EVALUATION_OK_MORE:
3498 case GNUNET_BLOCK_EVALUATION_OK_LAST:
3501 case GNUNET_BLOCK_EVALUATION_OK_DUPLICATE:
3502 case GNUNET_BLOCK_EVALUATION_RESULT_INVALID:
3503 case GNUNET_BLOCK_EVALUATION_RESULT_IRRELEVANT:
3504 case GNUNET_BLOCK_EVALUATION_REQUEST_VALID:
3505 case GNUNET_BLOCK_EVALUATION_REQUEST_INVALID:
3506 case GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED:
3508 GNUNET_break_op (0);
3513 /* extend 'put path' by sender */
3514 struct GNUNET_PeerIdentity pp[putlen + 1];
3515 if (0 != (options & GNUNET_DHT_RO_RECORD_ROUTE))
3517 memcpy (pp, put_path, putlen * sizeof (struct GNUNET_PeerIdentity));
3524 memcpy (&key_value, &(put->key), sizeof (uint64_t));
3525 if (0 != (GNUNET_CRYPTO_cmp_peer_identity (&best_known_dest, &my_identity)))
3527 next_hop = GDS_ROUTING_get_next_hop (intermediate_trail_id,
3528 GDS_ROUTING_SRC_TO_DEST);
3532 key_value = GNUNET_ntohll (key_value);
3533 next_hop = find_successor (key_value, &best_known_dest,
3534 &intermediate_trail_id, GDS_FINGER_TYPE_NON_PREDECESSOR);
3537 if (NULL == next_hop)
3539 GNUNET_STATISTICS_update (GDS_stats,
3540 gettext_noop ("# Next hop to forward the packet not found "
3541 "trail setup request, packet dropped."),
3543 return GNUNET_SYSERR;
3546 GDS_CLIENTS_process_put (options,
3547 ntohl (put->block_type),
3548 ntohl (put->hop_count),
3549 ntohl (put->desired_replication_level),
3551 GNUNET_TIME_absolute_ntoh (put->expiration_time),
3556 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &best_known_dest)) /* I am the final destination */
3558 GDS_DATACACHE_handle_put (GNUNET_TIME_absolute_ntoh (put->expiration_time),
3559 &(put->key),putlen, pp, ntohl (put->block_type),
3560 payload_size, payload);
3561 GNUNET_free_non_null (next_hop);
3566 GDS_NEIGHBOURS_send_put (&put->key,
3567 ntohl (put->block_type),ntohl (put->options),
3568 ntohl (put->desired_replication_level),
3569 &best_known_dest, &intermediate_trail_id, next_hop,
3570 ntohl (put->hop_count), putlen, pp,
3571 GNUNET_TIME_absolute_ntoh (put->expiration_time),
3572 payload, payload_size);
3576 return GNUNET_SYSERR;
3581 * Core handler for p2p get requests.
3583 * @param cls closure
3584 * @param peer sender of the request
3585 * @param message message
3586 * @return #GNUNET_OK to keep the connection open,
3587 * #GNUNET_SYSERR to close it (signal serious error)
3590 handle_dht_p2p_get (void *cls, const struct GNUNET_PeerIdentity *peer,
3591 const struct GNUNET_MessageHeader *message)
3593 const struct PeerGetMessage *get;
3594 const struct GNUNET_PeerIdentity *get_path;
3595 struct GNUNET_PeerIdentity best_known_dest;
3596 struct GNUNET_HashCode intermediate_trail_id;
3597 struct GNUNET_PeerIdentity *next_hop;
3598 uint32_t get_length;
3602 msize = ntohs (message->size);
3603 if (msize < sizeof (struct PeerGetMessage))
3605 GNUNET_break_op (0);
3609 get = (const struct PeerGetMessage *)message;
3610 get_length = ntohl (get->get_path_length);
3611 best_known_dest = get->best_known_destination;
3612 intermediate_trail_id = get->intermediate_trail_id;
3613 get_path = (const struct GNUNET_PeerIdentity *)&get[1];
3616 sizeof (struct PeerGetMessage) +
3617 get_length * sizeof (struct GNUNET_PeerIdentity)) ||
3619 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)))
3621 GNUNET_break_op (0);
3625 /* Add sender to get path */
3626 struct GNUNET_PeerIdentity gp[get_length + 1];
3628 memcpy (gp, get_path, get_length * sizeof (struct GNUNET_PeerIdentity));
3629 gp[get_length] = *peer;
3630 get_length = get_length + 1;
3632 memcpy (&key_value, &(get->key), sizeof (uint64_t));
3633 key_value = GNUNET_ntohll (key_value);
3635 /* I am not the final destination. I am part of trail to reach final dest. */
3636 if (0 != (GNUNET_CRYPTO_cmp_peer_identity (&best_known_dest, &my_identity)))
3638 next_hop = GDS_ROUTING_get_next_hop (intermediate_trail_id,
3639 GDS_ROUTING_SRC_TO_DEST);
3643 /* Get the next hop to pass the message to. */
3644 next_hop = find_successor (key_value, &best_known_dest,
3645 &intermediate_trail_id, GDS_FINGER_TYPE_NON_PREDECESSOR);
3648 if (NULL == next_hop)
3650 GNUNET_STATISTICS_update (GDS_stats,
3651 gettext_noop ("# Next hop to forward the packet not found "
3652 "trail setup request, packet dropped."),
3654 return GNUNET_SYSERR;
3656 GDS_CLIENTS_process_get (get->options, get->block_type,get->hop_count,
3657 get->desired_replication_level, get->get_path_length,
3659 /* I am the final destination. */
3660 if (0 == GNUNET_CRYPTO_cmp_peer_identity(&my_identity, &best_known_dest))
3662 struct GNUNET_PeerIdentity final_get_path[get_length+1];
3663 struct GNUNET_PeerIdentity next_hop;
3665 memcpy (final_get_path, gp, get_length * sizeof (struct GNUNET_PeerIdentity));
3666 memcpy (&final_get_path[get_length], &my_identity, sizeof (struct GNUNET_PeerIdentity));
3667 get_length = get_length + 1;
3669 /* Get the next hop to pass the get result message. */
3670 memcpy (&next_hop, &final_get_path[get_length-2], sizeof (struct GNUNET_PeerIdentity));
3671 GDS_DATACACHE_handle_get (&(get->key),(get->block_type), NULL, 0, NULL, 0,
3672 get_length, final_get_path, &next_hop, &my_identity);
3677 GDS_NEIGHBOURS_send_get (&(get->key), get->block_type, get->options,
3678 get->desired_replication_level, &best_known_dest,
3679 &intermediate_trail_id, next_hop, 0,
3682 GNUNET_free_non_null (next_hop);
3683 return GNUNET_SYSERR;
3688 * Core handler for get result
3689 * @param cls closure
3690 * @param peer sender of the request
3691 * @param message message
3692 * @return #GNUNET_OK to keep the connection open,
3693 * #GNUNET_SYSERR to close it (signal serious error)
3696 handle_dht_p2p_get_result (void *cls, const struct GNUNET_PeerIdentity *peer,
3697 const struct GNUNET_MessageHeader *message)
3699 const struct PeerGetResultMessage *get_result;
3700 const struct GNUNET_PeerIdentity *get_path;
3701 const struct GNUNET_PeerIdentity *put_path;
3702 const void *payload;
3703 size_t payload_size;
3705 unsigned int getlen;
3706 unsigned int putlen;
3707 int current_path_index;
3709 msize = ntohs (message->size);
3710 if (msize < sizeof (struct PeerGetResultMessage))
3712 GNUNET_break_op (0);
3716 get_result = (const struct PeerGetResultMessage *)message;
3717 getlen = ntohl (get_result->get_path_length);
3718 putlen = ntohl (get_result->put_path_length);
3721 sizeof (struct PeerGetResultMessage) +
3722 getlen * sizeof (struct GNUNET_PeerIdentity) +
3723 putlen * sizeof (struct GNUNET_PeerIdentity)) ||
3725 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity) ||
3727 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity))))
3729 GNUNET_break_op (0);
3733 put_path = (const struct GNUNET_PeerIdentity *) &get_result[1];
3734 get_path = &put_path[putlen];
3735 payload = (const void *) &get_path[getlen];
3736 payload_size = msize - (sizeof (struct PeerGetResultMessage) +
3737 (getlen + putlen) * sizeof (struct GNUNET_PeerIdentity));
3739 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &(get_path[0]))))
3741 GDS_CLIENTS_handle_reply (get_result->expiration_time, &(get_result->key),
3742 getlen, get_path, putlen,
3743 put_path, get_result->type, payload_size, payload);
3748 current_path_index = search_my_index (get_path, getlen);
3749 if (-1 == current_path_index )
3752 return GNUNET_SYSERR;
3754 GDS_NEIGHBOURS_send_get_result (&(get_result->key), get_result->type,
3755 &get_path[current_path_index - 1],
3756 &(get_result->querying_peer), putlen, put_path,
3757 getlen, get_path, get_result->expiration_time,
3758 payload, payload_size);
3761 return GNUNET_SYSERR;
3766 * Get the best known next destination (local_dest) among your fingers, friends
3767 * and my identity. In case I was part of trail to reach to some other destination
3768 * (current_dest), then compare current_dest and local_dest, and choose the
3770 * @param final_dest_finger_value Peer closest to this value will be
3771 * @a local_best_known_dest
3772 * @param local_best_known_dest[out] Updated to peer identity which is closest to
3773 * @a final_dest_finger_value.
3774 * @param new_intermediate_trail_id In case @a local_best_known_dest is a finger,
3775 * then the trail id to reach to the finger
3776 * @param is_predecessor Is source peer trying to setup trail to its predecessor
3778 * @param current_dest Peer which should get this message ultimately according
3779 * to the peer which sent me this message. It could be me
3780 * or some other peer. In case it is not me, then I am a part
3781 * of trail to reach to that peer.
3784 static struct GNUNET_PeerIdentity *
3785 get_local_best_known_next_hop (uint64_t final_dest_finger_value,
3786 struct GNUNET_PeerIdentity *local_best_known_dest,
3787 struct GNUNET_HashCode *new_intermediate_trail_id,
3788 struct GNUNET_HashCode intermediate_trail_id,
3789 unsigned int is_predecessor,
3790 struct GNUNET_PeerIdentity *current_dest)
3792 struct GNUNET_PeerIdentity *next_hop_to_local_best_known_dest;
3794 /* Choose a local best known hop among your fingers, friends and you. */
3795 next_hop_to_local_best_known_dest = find_successor (final_dest_finger_value,
3796 local_best_known_dest,
3797 new_intermediate_trail_id,
3800 /* Are we just a part of a trail towards a finger (current_destination)? */
3801 if (0 != (GNUNET_CRYPTO_cmp_peer_identity (&my_identity, current_dest)))
3803 struct GNUNET_PeerIdentity print_peer;
3804 memcpy(&print_peer, current_dest, sizeof (struct GNUNET_PeerIdentity));
3806 struct GNUNET_PeerIdentity *closest_peer;
3808 /* Select best successor among one found locally and current_destination
3809 * that we got from network.*/
3810 if (0 != GNUNET_CRYPTO_cmp_peer_identity (local_best_known_dest, current_dest))
3812 closest_peer = select_closest_peer (local_best_known_dest,
3814 final_dest_finger_value,
3817 /* Is current dest (end point of the trail of which I am a part) closest_peer? */
3818 if (0 == GNUNET_CRYPTO_cmp_peer_identity (current_dest, closest_peer))
3820 struct GNUNET_PeerIdentity *next_hop;
3821 next_hop = GDS_ROUTING_get_next_hop (intermediate_trail_id,
3822 GDS_ROUTING_SRC_TO_DEST);
3823 /* FIXME: Here we found next_hop NULL from routing table, but we still
3824 * have a next_hop from find_successor should we not break and choose that
3826 if (NULL == next_hop)
3828 GNUNET_break_op (0);
3831 next_hop_to_local_best_known_dest = next_hop;
3832 local_best_known_dest = current_dest;
3833 *new_intermediate_trail_id = intermediate_trail_id;
3838 GNUNET_assert (NULL != next_hop_to_local_best_known_dest);
3839 return next_hop_to_local_best_known_dest;
3844 * Core handle for PeerTrailSetupMessage.
3845 * @param cls closure
3846 * @param message message
3847 * @param peer peer identity this notification is about
3848 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
3851 handle_dht_p2p_trail_setup (void *cls, const struct GNUNET_PeerIdentity *peer,
3852 const struct GNUNET_MessageHeader *message)
3854 const struct PeerTrailSetupMessage *trail_setup;
3855 const struct GNUNET_PeerIdentity *trail_peer_list;
3856 struct GNUNET_PeerIdentity *local_best_known_dest;
3857 struct GNUNET_PeerIdentity current_dest;
3858 struct GNUNET_PeerIdentity *next_hop_towards_local_best_known_dest;
3859 struct FriendInfo *target_friend;
3860 struct GNUNET_PeerIdentity source;
3861 uint64_t final_dest_finger_val;
3862 struct GNUNET_HashCode new_intermediate_trail_id;
3863 struct GNUNET_HashCode intermediate_trail_id;
3864 struct GNUNET_HashCode trail_id;
3865 unsigned int is_predecessor;
3866 uint32_t trail_length;
3869 msize = ntohs (message->size);
3870 if (msize < sizeof (struct PeerTrailSetupMessage))
3872 GNUNET_break_op (0);
3876 trail_setup = (const struct PeerTrailSetupMessage *) message;
3877 trail_length = (msize - sizeof (struct PeerTrailSetupMessage))/
3878 sizeof (struct GNUNET_PeerIdentity);
3879 if ((msize - sizeof (struct PeerTrailSetupMessage)) %
3880 sizeof (struct GNUNET_PeerIdentity) != 0)
3882 GNUNET_break_op (0);
3886 trail_peer_list = (const struct GNUNET_PeerIdentity *)&trail_setup[1];
3887 current_dest = trail_setup->best_known_destination;
3888 trail_id = trail_setup->trail_id;
3889 final_dest_finger_val =
3890 GNUNET_ntohll (trail_setup->final_destination_finger_value);
3891 source = trail_setup->source_peer;
3892 is_predecessor = ntohl (trail_setup->is_predecessor);
3893 intermediate_trail_id = trail_setup->intermediate_trail_id;
3895 /* Is my routing table full? */
3896 if (GNUNET_YES == GDS_ROUTING_threshold_reached())
3898 /* As my routing table is full, I can no longer handle any more trail
3900 GNUNET_assert (NULL !=
3902 GNUNET_CONTAINER_multipeermap_get (friend_peermap, peer)));
3903 GDS_NEIGHBOURS_send_trail_rejection (source, final_dest_finger_val,
3904 my_identity, is_predecessor,
3905 trail_peer_list, trail_length,
3906 trail_id, target_friend,
3907 CONGESTION_TIMEOUT);
3911 local_best_known_dest = GNUNET_new (struct GNUNET_PeerIdentity);
3913 /* Get the next hop to forward the trail setup request. */
3914 next_hop_towards_local_best_known_dest =
3915 get_local_best_known_next_hop (final_dest_finger_val,
3916 local_best_known_dest,
3917 &new_intermediate_trail_id,
3918 intermediate_trail_id,
3922 GNUNET_assert (NULL != local_best_known_dest);
3923 GNUNET_assert (NULL != next_hop_towards_local_best_known_dest);
3924 /* Am I the final destination? */
3925 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (local_best_known_dest,
3928 /* FIXME: check that you always add trail entry even if your finger is
3930 /* If I was not the source of this message for which now I am destination */
3931 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&source, &my_identity))
3933 GDS_ROUTING_add (trail_id, *peer, my_identity);
3936 GNUNET_assert (NULL !=
3938 GNUNET_CONTAINER_multipeermap_get (friend_peermap, peer)));
3939 GDS_NEIGHBOURS_send_trail_setup_result (source,
3941 target_friend, trail_length,
3943 final_dest_finger_val,
3944 is_predecessor, trail_id);
3948 /* Add yourself to list of peers. */
3949 struct GNUNET_PeerIdentity peer_list[trail_length + 1];
3951 memcpy (peer_list, trail_peer_list,
3952 trail_length * sizeof (struct GNUNET_PeerIdentity));
3953 peer_list[trail_length] = my_identity;
3954 GNUNET_assert (NULL !=
3956 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
3957 next_hop_towards_local_best_known_dest)));
3958 GDS_NEIGHBOURS_send_trail_setup (source,
3959 final_dest_finger_val,
3960 *local_best_known_dest,
3961 target_friend, trail_length + 1, peer_list,
3962 is_predecessor, trail_id,
3963 &new_intermediate_trail_id);
3965 GNUNET_free (local_best_known_dest);
3966 GNUNET_free (next_hop_towards_local_best_known_dest);
3971 /* FIXME: here we are calculating my_index and comparing also in this function.
3972 And we are doing it again here in this function. Re factor the code. */
3974 * FIXME: Should we call this function everywhere in all the handle functions
3975 * where we have a trail to verify from or a trail id. something like
3976 * if prev hop is not same then drop the message.
3977 * Check if sender_peer and peer from which we should receive the message are
3978 * same or different.
3979 * @param trail_peer_list List of peers in trail
3980 * @param trail_length Total number of peers in @a trail_peer_list
3981 * @param sender_peer Peer from which we got the message.
3982 * @param finger_identity Finger to which trail is setup. It is not part of trail.
3983 * @return #GNUNET_YES if sender_peer and peer from which we should receive the
3984 * message are different.
3985 * #GNUNET_NO if sender_peer and peer from which we should receive the
3986 * message are different.
3989 is_sender_peer_correct (const struct GNUNET_PeerIdentity *trail_peer_list,
3990 unsigned int trail_length,
3991 const struct GNUNET_PeerIdentity *sender_peer,
3992 struct GNUNET_PeerIdentity finger_identity,
3993 struct GNUNET_PeerIdentity source_peer)
3997 /* I am the source peer. */
3998 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (&source_peer,
4001 /* Is the first element of the trail is sender_peer.*/
4002 if (trail_length > 0)
4004 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&trail_peer_list[0],
4010 /* Is finger the sender peer? */
4011 if (0 != GNUNET_CRYPTO_cmp_peer_identity (sender_peer,
4018 /* Get my current location in the trail. */
4019 my_index = search_my_index (trail_peer_list, trail_length);
4023 /* I am the last element in the trail. */
4024 if ((trail_length - 1) == my_index)
4026 /* Is finger the sender_peer? */
4027 if (0 != GNUNET_CRYPTO_cmp_peer_identity (sender_peer,
4033 /* Is peer after me in trail the sender peer? */
4034 if (0 != GNUNET_CRYPTO_cmp_peer_identity (sender_peer,
4035 &trail_peer_list[my_index + 1]))
4044 * FIXME: we should also add a case where we search if we are present in the trail
4046 * Core handle for p2p trail setup result messages.
4048 * @param message message
4049 * @param peer sender of this message.
4050 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
4053 handle_dht_p2p_trail_setup_result(void *cls, const struct GNUNET_PeerIdentity *peer,
4054 const struct GNUNET_MessageHeader *message)
4056 const struct PeerTrailSetupResultMessage *trail_result;
4057 const struct GNUNET_PeerIdentity *trail_peer_list;
4058 struct GNUNET_PeerIdentity next_hop;
4059 struct FriendInfo *target_friend;
4060 struct GNUNET_PeerIdentity querying_peer;
4061 struct GNUNET_PeerIdentity finger_identity;
4062 uint32_t trail_length;
4063 uint64_t ulitmate_destination_finger_value;
4064 uint32_t is_predecessor;
4065 struct GNUNET_HashCode trail_id;
4069 msize = ntohs (message->size);
4070 if (msize < sizeof (struct PeerTrailSetupResultMessage))
4072 GNUNET_break_op (0);
4076 trail_result = (const struct PeerTrailSetupResultMessage *) message;
4077 trail_length = (msize - sizeof (struct PeerTrailSetupResultMessage))/
4078 sizeof (struct GNUNET_PeerIdentity);
4079 if ((msize - sizeof (struct PeerTrailSetupResultMessage)) %
4080 sizeof (struct GNUNET_PeerIdentity) != 0)
4082 GNUNET_break_op (0);
4086 is_predecessor = htonl (trail_result->is_predecessor);
4087 querying_peer = trail_result->querying_peer;
4088 finger_identity = trail_result->finger_identity;
4089 trail_id = trail_result->trail_id;
4090 trail_peer_list = (const struct GNUNET_PeerIdentity *) &trail_result[1];
4091 ulitmate_destination_finger_value =
4092 GNUNET_ntohll (trail_result->ulitmate_destination_finger_value);
4094 /* FIXME: here we are calculating my_index and comparing also in this function.
4095 And we are doing it again here in this function. Re factor the code. */
4096 /* Ensure that sender peer is the peer from which we were expecting the message. */
4098 if (GNUNET_NO == is_sender_peer_correct (trail_peer_list,
4100 peer, finger_identity, querying_peer))
4102 GNUNET_break_op (0);
4103 return GNUNET_SYSERR;
4107 /* Am I the one who initiated the query? */
4108 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (&querying_peer,
4111 /* If I am not my own finger identity, then add routing table entry. */
4112 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &finger_identity))
4114 /* FIXME: check that you always add trail entry even if your finger is
4116 GDS_ROUTING_add (trail_id, my_identity, *peer);
4119 finger_table_add (finger_identity, trail_peer_list,
4120 trail_length, ulitmate_destination_finger_value,
4121 is_predecessor, trail_id);
4125 /* Get my location in the trail. */
4126 my_index = search_my_index(trail_peer_list, trail_length);
4130 return GNUNET_SYSERR;
4133 /* FIXME: CHECK IF YOU ARE PRESENT MORE THAN ONCE IN THE TRAIL, IF YES
4134 THEN REMOVE ALL THE ENTRIES AND CHOOSE THE PEER THERE.*/
4136 next_hop = trail_result->querying_peer;
4138 next_hop = trail_peer_list[my_index - 1];
4140 /* If the querying_peer is its own finger, then don't add an entry in routing
4141 * table as querying peer will discard the trail. */
4142 if (0 != (GNUNET_CRYPTO_cmp_peer_identity (&(trail_result->querying_peer),
4143 &(trail_result->finger_identity))))
4145 /* FIXME: check that you always add trail entry even if your finger is
4147 GDS_ROUTING_add (trail_id, next_hop, *peer);
4150 GNUNET_assert (NULL !=
4152 GNUNET_CONTAINER_multipeermap_get (friend_peermap, &next_hop)));
4153 GDS_NEIGHBOURS_send_trail_setup_result (querying_peer, finger_identity,
4154 target_friend, trail_length, trail_peer_list,
4156 ulitmate_destination_finger_value,
4164 * @param trail Trail to be inverted
4165 * @param trail_length Total number of peers in the trail.
4166 * @return Updated trail
4168 static struct GNUNET_PeerIdentity *
4169 invert_trail (const struct GNUNET_PeerIdentity *trail,
4170 unsigned int trail_length)
4174 struct GNUNET_PeerIdentity *inverted_trail;
4176 inverted_trail = GNUNET_malloc (sizeof(struct GNUNET_PeerIdentity) *
4179 j = trail_length - 1;
4180 while (i < trail_length)
4182 inverted_trail[i] = trail[j];
4186 return inverted_trail;
4191 * Return the shortest trail to reach from me to my_predecessor.
4192 * @param my_predecessor my current predecessor.
4193 * @param current_trail Trail from source to me.
4194 * @param current_trail_length Total number of peers in @a current_trail
4195 * @param trail_length [out] Total number of peers in selected trail.
4196 * @return Updated trail from source peer to my_predecessor.
4198 static struct GNUNET_PeerIdentity *
4199 trail_source_to_my_predecessor (const struct GNUNET_PeerIdentity *current_trail,
4200 unsigned int current_trail_length,
4201 unsigned int *trail_length)
4203 struct GNUNET_PeerIdentity *trail_me_to_predecessor;
4204 struct Trail *trail;
4205 struct Trail_Element *trail_element;
4206 struct FingerInfo *my_predecessor;
4208 unsigned int shortest_trail_length = 0;
4209 unsigned int trail_index = 0;
4211 my_predecessor = &finger_table[PREDECESSOR_FINGER_ID];
4213 GNUNET_assert (GNUNET_YES == my_predecessor->is_present);
4215 //if my_predecessor is a friend then don't send back any trail. as
4216 // there is no trail.
4219 /* Choose the shortest path from me to my predecessor. */
4220 for (i = 0; i < my_predecessor->trails_count; i++)
4222 trail = &my_predecessor->trail_list[i];
4223 if (trail->trail_length > shortest_trail_length)
4225 shortest_trail_length = trail->trail_length;
4229 *trail_length = shortest_trail_length;
4230 trail_me_to_predecessor = GNUNET_malloc (sizeof (struct GNUNET_PeerIdentity)
4233 /* Copy the selected trail and send this trail to calling function. */
4235 trail = &my_predecessor->trail_list[trail_index];
4236 trail_element = trail->trail_head;
4237 while ( i < shortest_trail_length)
4239 trail_me_to_predecessor[i] = trail_element->peer;
4241 trail_element = trail_element->next;
4244 return trail_me_to_predecessor;
4249 * FIXME In case predecessor is a friend then do we add it in routing table.
4250 * if not then check the logic of trail teardown in case we compress the trail
4251 * such that friend is finger. then do we remove the entry from end points or
4252 * not. Ideally we should remove the entries from end point.
4253 * Add finger as your predecessor. To add, first generate a new trail id, invert
4254 * the trail to get the trail from me to finger, add an entry in your routing
4255 * table, send add trail message to peers which are part of trail from me to
4256 * finger and add finger in finger table.
4259 * @param trail_length
4262 update_predecessor (struct GNUNET_PeerIdentity finger,
4263 struct GNUNET_PeerIdentity *trail,
4264 unsigned int trail_length)
4266 struct GNUNET_HashCode trail_to_new_predecessor_id;
4267 struct GNUNET_PeerIdentity *trail_to_new_predecessor;
4268 struct FriendInfo *target_friend;
4270 /* Generate trail id for trail from me to new predecessor = finger. */
4271 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_STRONG,
4272 &trail_to_new_predecessor_id,
4273 sizeof (trail_to_new_predecessor_id));
4275 /* Finger is a friend. */
4276 if (trail_length == 0)
4278 trail_to_new_predecessor = NULL;
4279 /* FIXME: check that you always add trail entry even if your finger is
4281 GDS_ROUTING_add (trail_to_new_predecessor_id, finger, my_identity);
4282 GNUNET_assert (NULL != (target_friend =
4283 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4288 /* Invert the trail to get the trail from me to finger, NOT including the
4290 trail_to_new_predecessor = invert_trail (trail, trail_length);
4291 /* FIXME: check that you always add trail entry even if your finger is
4293 /* Add an entry in your routing table. */
4294 GDS_ROUTING_add (trail_to_new_predecessor_id,
4295 trail_to_new_predecessor[trail_length - 1],
4298 GNUNET_assert (NULL != (target_friend =
4299 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4300 &trail_to_new_predecessor[trail_length - 1])));
4303 /* Add entry in routing table of all peers that are part of trail from me
4304 to finger, including finger. */
4305 GDS_NEIGHBOURS_send_add_trail (my_identity,
4307 trail_to_new_predecessor_id,
4308 trail_to_new_predecessor,
4312 add_new_finger (finger, trail_to_new_predecessor, trail_length,
4313 trail_to_new_predecessor_id, PREDECESSOR_FINGER_ID);
4314 GNUNET_free_non_null (trail_to_new_predecessor);
4318 /* 3. In case you are successor, then
4319 * 3.1 check if you have a predecessor
4320 * 3.2 if no predecessor, then add the source of this message as your
4321 * predecessor. To add, first you should generate a new trail id,
4322 * invert the trail, send add trail message across new trail, add
4323 * an entry in finger table. Now, destination also have routing
4324 * table entry so add in your routing table also.
4325 * 3.3 If its closer than existing one, then do everything in step 1 and
4326 * free existing finger.
4327 * 3.3 If its same as the old one, then do nothing.
4328 * 3.4 if its not same as old one, and between source and old one, old one
4329 * is the correct predecessor, then construct a trail from source
4330 * to your old successor. scan the trail to remove duplicate entries.
4331 * 4. send verify successor result, with trail id of trail from source to
4332 * me. And also send the new trail from source to reach to its probable
4335 * 1. this function is called from both verify and notify.
4336 * 2. so write in a way that it is used in both.
4339 * Check if you have a predecessor.
4340 * 1. if no predecessor, then add finger as your predecessor. To add, first
4341 * generate a new trail id, invert the trail to get the trail from me to finger,
4342 * add an entry in your routing table, send add trail message to peers which
4343 * are part of trail from me to finger and add finger in finger table.
4344 * 2. If there is a predecessor, then compare existing one and finger.
4345 * 2.1 If finger is correct predecessor, then remove current_predecessor. And
4346 * do everything in step 1 to add finger into finger table.
4347 * 2.2 If current_predecessor is correct predecessor, the construct a trail from
4348 * finger to current_predecessor.
4351 * @param trail_length
4355 compare_and_update_predecessor (struct GNUNET_PeerIdentity finger,
4356 struct GNUNET_PeerIdentity *trail,
4357 unsigned int trail_length)
4359 struct FingerInfo *current_predecessor;
4360 struct GNUNET_PeerIdentity *closest_peer;
4361 uint64_t predecessor_value;
4362 unsigned int is_predecessor = 1;
4364 current_predecessor = &finger_table[PREDECESSOR_FINGER_ID];
4366 GNUNET_assert (0 != GNUNET_CRYPTO_cmp_peer_identity (&finger, &my_identity));
4368 /* No predecessor. Add finger as your predecessor. */
4369 if (GNUNET_NO == current_predecessor->is_present)
4371 update_predecessor (finger, trail, trail_length);
4375 predecessor_value = compute_finger_identity_value (PREDECESSOR_FINGER_ID);
4376 closest_peer = select_closest_peer (&finger,
4377 ¤t_predecessor->finger_identity,
4378 predecessor_value, is_predecessor);
4380 /* Finger is the closest predecessor. Remove the existing one and add the new
4382 if (0 == GNUNET_CRYPTO_cmp_peer_identity (closest_peer, &finger))
4384 remove_existing_finger (current_predecessor, PREDECESSOR_FINGER_ID);
4385 update_predecessor (finger, trail, trail_length);
4394 * FIXME: if i have no predecessor and I get a new predecessor but the first
4395 * friend to reach to that hop is congested then?
4396 * 1. check if you are the successor or not.
4397 * 2. if not then get the next hop from routing table, and pass the message,
4398 * 3. In case you are successor, then
4399 * 3.1 check if you have a predecessor
4400 * 3.2 if no predecessor, then add the source of this message as your
4401 * predecessor. To add, first you should generate a new trail id,
4402 * invert the trail, send add trail message across new trail, add
4403 * an entry in finger table. Now, destination also have routing
4404 * table entry so add in your routing table also.
4405 * 3.3 If its closer than existing one, then do everything in step 1 and
4406 * free existing finger.
4407 * 3.3 If its same as the old one, then do nothing.
4408 * 3.4 if its not same as old one, and between source and old one, old one
4409 * is the correct predecessor, then choose the shortest path to reach
4410 * from you to your predecessor. Pass this trail to source of this message.
4411 * It is the responsibility of source peer to scan the trail to reach to
4412 * its new probable successor.
4413 * 4. send verify successor result, with trail id of trail from source to
4414 * me. And also send the trail from me to reach to my predecessor, if
4415 * my_predecessor != source.
4417 * Core handle for p2p verify successor messages.
4418 * @param cls closure
4419 * @param message message
4420 * @param peer peer identity this notification is about
4421 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
4424 handle_dht_p2p_verify_successor(void *cls,
4425 const struct GNUNET_PeerIdentity *peer,
4426 const struct GNUNET_MessageHeader *message)
4428 const struct PeerVerifySuccessorMessage *vsm;
4429 struct GNUNET_HashCode trail_id;
4430 struct GNUNET_PeerIdentity successor;
4431 struct GNUNET_PeerIdentity source_peer;
4432 struct GNUNET_PeerIdentity *trail;
4433 struct GNUNET_PeerIdentity *next_hop;
4434 struct GNUNET_PeerIdentity *trail_to_predecessor;
4435 struct FingerInfo *current_predecessor;
4436 struct FriendInfo *target_friend;
4437 unsigned int trail_to_predecessor_length;
4439 unsigned int trail_length;
4441 msize = ntohs (message->size);
4443 /* Here we pass trail to reach from source to successor, and in case successor
4444 * does not have any predecessor, then we will add source as my predecessor.
4445 * So we pass the trail along with trail id. */
4446 if (msize < sizeof (struct PeerVerifySuccessorMessage))
4448 GNUNET_break_op (0);
4452 vsm = (const struct PeerVerifySuccessorMessage *) message;
4453 trail_length = (msize - sizeof (struct PeerVerifySuccessorMessage))/
4454 sizeof (struct GNUNET_PeerIdentity);
4455 if ((msize - sizeof (struct PeerVerifySuccessorMessage)) %
4456 sizeof (struct GNUNET_PeerIdentity) != 0)
4458 GNUNET_break_op (0);
4462 trail_id = vsm->trail_id;
4463 source_peer = vsm->source_peer;
4464 successor = vsm->successor;
4465 trail = (struct GNUNET_PeerIdentity *)&vsm[1];
4467 //FIXME: we can have a check if peer is correct peer which should have
4468 // sent this message. use same function is_sender_peer_correct
4469 // but specify direction so that the function can be used in other functions
4472 /* I am not the successor of source_peer. Pass the message to next_hop on
4474 if(0 != (GNUNET_CRYPTO_cmp_peer_identity (&successor, &my_identity)))
4476 next_hop = GDS_ROUTING_get_next_hop (trail_id, GDS_ROUTING_SRC_TO_DEST);
4477 if (NULL == next_hop)
4480 return GNUNET_SYSERR;
4482 GNUNET_assert (NULL !=
4484 GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop)));
4486 GDS_NEIGHBOURS_send_verify_successor_message (source_peer, successor,
4487 trail_id, trail, trail_length,
4492 /* I am the destination of this message. */
4494 /* Check if the source_peer could be our predecessor and if yes then update
4496 compare_and_update_predecessor (source_peer, trail, trail_length);
4498 current_predecessor = &finger_table[PREDECESSOR_FINGER_ID];
4500 /* Is source of this message NOT my predecessor. */
4501 if (0 != (GNUNET_CRYPTO_cmp_peer_identity (¤t_predecessor->finger_identity,
4504 /* if current predecessor is not a friend, we have a trail to reach to it*/
4505 if (NULL == (GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4506 ¤t_predecessor->finger_identity)))
4508 trail_to_predecessor =
4509 trail_source_to_my_predecessor (trail,
4511 &trail_to_predecessor_length);
4516 trail_to_predecessor = NULL;
4517 trail_to_predecessor_length = 0;
4519 GNUNET_assert (NULL !=
4521 GNUNET_CONTAINER_multipeermap_get (friend_peermap, peer)));
4522 GDS_NEIGHBOURS_send_verify_successor_result (source_peer, my_identity,
4523 current_predecessor->finger_identity,
4524 trail_id, trail_to_predecessor,
4525 trail_to_predecessor_length,
4526 GDS_ROUTING_DEST_TO_SRC,
4528 GNUNET_free_non_null (trail_to_predecessor);
4534 * Construct the trail from me to probable successor that goes through current
4535 * successor. Scan this trail to check if you can shortcut the trail somehow.
4536 * In case we can shortcut the trail, don't send trail compression as we don't
4537 * have any entry in routing table.
4538 * @param current_successor
4539 * @param probable_successor
4540 * @param trail_from_curr_to_probable_successor
4541 * @param trail_from_curr_to_probable_successor_length
4542 * @param trail_to_new_successor_length
4545 static struct GNUNET_PeerIdentity *
4546 get_trail_to_new_successor (struct FingerInfo *current_successor,
4547 struct GNUNET_PeerIdentity probable_successor,
4548 const struct GNUNET_PeerIdentity *trail,
4549 unsigned int trail_length,
4550 unsigned int *trail_to_new_successor_length)
4552 struct GNUNET_PeerIdentity *trail_to_new_successor;
4554 /* If the probable successor is a friend, then we don't need to have a trail
4556 if (NULL != GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4557 &probable_successor))
4559 trail_to_new_successor = NULL;
4560 *trail_to_new_successor_length = 0;
4561 return trail_to_new_successor;
4565 * FIXME: can we some how use the select_finger_trail here??
4566 * complete this logic.
4567 * 1. Choose the shortest trail to reach to current successor.
4568 * 2. append the trail with the current trail
4569 * 3. scan the trail for duplicate elements
4570 * 4. scan the trail for friend
4571 * 5. get the shortest trail.
4572 * 6. send back the trail.
4579 * Compare probable successor and current successor.
4580 * If the probable successor is the correct successor, then construct the trail
4581 * from me to probable successor that goes through current successor. Scan this
4582 * trail to check if you can shortcut the trail somehow. In case we can short
4583 * cut the trail, don't send trail compression as we don't have any entry in
4585 * Once you have scanned trail, then add an entry in finger table.
4586 * Add an entry in routing table (Only if new successor is NOT a friend).
4587 * @param probable_successor Peer which could be our successor
4588 * @param trail_from_curr_to_probable_successor Trail from current successor
4589 * to probable successor, NOT
4591 * @param trail_from_curr_to_probable_successor_length Total number of peers
4592 * in @a trail_from_curr_to_probable_successor
4595 compare_and_update_successor (struct GNUNET_PeerIdentity probable_successor,
4596 const struct GNUNET_PeerIdentity *trail_from_curr_to_probable_successor,
4597 unsigned int trail_from_curr_to_probable_successor_length)
4599 struct GNUNET_PeerIdentity *closest_peer;
4600 struct GNUNET_PeerIdentity *trail_to_new_successor;
4601 struct GNUNET_HashCode trail_id;
4602 unsigned int trail_to_new_successor_length;
4603 uint64_t successor_value;
4604 struct FingerInfo *current_successor;
4605 struct FriendInfo *target_friend;
4606 unsigned int is_predecessor = 0;
4608 current_successor = &finger_table[0];
4609 GNUNET_assert (GNUNET_YES == current_successor->is_present);
4611 /* Compute the 64 bit value of successor identity. We need this as we need to
4612 * find the closest peer w.r.t this value.*/
4613 successor_value = compute_finger_identity_value (0);
4614 closest_peer = select_closest_peer (¤t_successor->finger_identity,
4615 &probable_successor,
4616 successor_value, is_predecessor);
4618 /* If the current_successor is the closest one, then exit. */
4619 if (0 == GNUNET_CRYPTO_cmp_peer_identity (closest_peer,
4620 ¤t_successor->finger_identity))
4623 /* probable successor is the closest_peer. */
4625 /* Get the trail to reach to your new successor. */
4626 trail_to_new_successor = get_trail_to_new_successor (current_successor,
4628 trail_from_curr_to_probable_successor,
4629 trail_from_curr_to_probable_successor_length,
4630 &trail_to_new_successor_length);
4631 /* Remove the existing successor. */
4632 remove_existing_finger (current_successor, 0);
4634 /* Generate a new trail id to reach to your new successor. */
4635 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_STRONG,
4636 &trail_id, sizeof (trail_id));
4637 add_new_finger (probable_successor, trail_to_new_successor,
4638 trail_to_new_successor_length, trail_id, 0);
4640 /* If probable successor is not a friend, then add an entry in your own
4642 if (trail_to_new_successor_length > 0)
4644 /* FIXME: check that you always add trail entry even if your finger is
4646 GDS_ROUTING_add (trail_id, my_identity, trail_to_new_successor[0]);
4647 GNUNET_assert (NULL !=
4648 (target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4649 &trail_to_new_successor[0])));
4653 /* FIXME: check that you always add trail entry even if your finger is
4655 GDS_ROUTING_add (trail_id, my_identity, probable_successor);
4656 GNUNET_assert (NULL !=
4658 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4659 &probable_successor)));
4662 GDS_NEIGHBOURS_send_notify_new_successor (my_identity, probable_successor,
4663 trail_from_curr_to_probable_successor,
4664 trail_from_curr_to_probable_successor_length,
4672 * 1. If you are not the querying peer then pass on the message,
4673 * 2. If you are querying peer, then
4674 * 2.1 is new successor same as old one
4675 * 2.1.1 if yes then do noting
4676 * 2.1.2 if no then you need to notify the new one about your existence,
4677 * 2.1.2,1 also you need to remove the older successor, remove entry
4678 * from finger table, send trail teardown message across all the trail
4679 * of older successor. Call notify new successor with new trail id
4680 * and new trail to reach it.
4681 * Core handle for p2p verify successor result messages.
4682 * @param cls closure
4683 * @param message message
4684 * @param peer peer identity this notification is about
4685 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
4688 handle_dht_p2p_verify_successor_result(void *cls,
4689 const struct GNUNET_PeerIdentity *peer,
4690 const struct GNUNET_MessageHeader *message)
4692 const struct PeerVerifySuccessorResultMessage *vsrm;
4693 enum GDS_ROUTING_trail_direction trail_direction;
4694 struct GNUNET_PeerIdentity querying_peer;
4695 struct GNUNET_HashCode trail_id;
4696 struct GNUNET_PeerIdentity *next_hop;
4697 struct FriendInfo *target_friend;
4698 struct GNUNET_PeerIdentity probable_successor;
4699 const struct GNUNET_PeerIdentity *trail;
4700 unsigned int trail_length;
4703 msize = ntohs (message->size);
4704 /* We send a trail to reach from old successor to new successor, if
4705 * old_successor != new_successor.*/
4706 if (msize < sizeof (struct PeerVerifySuccessorResultMessage))
4708 GNUNET_break_op (0);
4712 vsrm = (const struct PeerVerifySuccessorResultMessage *) message;
4713 trail_length = (msize - sizeof (struct PeerVerifySuccessorResultMessage))/
4714 sizeof (struct GNUNET_PeerIdentity);
4716 if ((msize - sizeof (struct PeerVerifySuccessorResultMessage)) %
4717 sizeof (struct GNUNET_PeerIdentity) != 0)
4719 GNUNET_break_op (0);
4723 trail = (const struct GNUNET_PeerIdentity *) &vsrm[1];
4724 querying_peer = vsrm->querying_peer;
4725 trail_direction = ntohl (vsrm->trail_direction);
4726 trail_id = vsrm->trail_id;
4727 probable_successor = vsrm->probable_successor;
4729 //FIXME: add a check to ensure that peer from which you got the message is
4731 /* I am the querying_peer. */
4732 if(0 == (GNUNET_CRYPTO_cmp_peer_identity (&querying_peer, &my_identity)))
4734 compare_and_update_successor (probable_successor, trail, trail_length);
4738 /*If you are not the querying peer then pass on the message */
4739 GNUNET_assert (NULL != (next_hop =
4740 GDS_ROUTING_get_next_hop (trail_id, trail_direction)));
4741 GNUNET_assert (NULL !=
4743 GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop)));
4744 GDS_NEIGHBOURS_send_verify_successor_result (querying_peer,
4745 vsrm->current_successor,
4746 probable_successor, trail_id,
4749 trail_direction, target_friend);
4755 * Add entry in your routing table if source of the message is not a friend.
4756 * Irrespective if destination peer accepts source peer as predecessor or not,
4757 * we need to add an entry. So, that in next round to verify successor, source
4758 * is able to reach to its successor.
4759 * Check if you are the new successor of this message
4760 * 1. If yes the call function compare_and_update_successor(). This function
4761 * checks if source is real predecessor or not and take action accordingly.
4762 * 2. If not then find the next hop to find the message from the trail that
4763 * you got from the message and pass on the message.
4764 * Core handle for p2p notify new successor messages.
4765 * @param cls closure
4766 * @param message message
4767 * @param peer peer identity this notification is about
4768 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
4771 handle_dht_p2p_notify_new_successor(void *cls,
4772 const struct GNUNET_PeerIdentity *peer,
4773 const struct GNUNET_MessageHeader *message)
4775 const struct PeerNotifyNewSuccessorMessage *nsm;
4776 struct GNUNET_PeerIdentity *trail;
4777 struct GNUNET_PeerIdentity source;
4778 struct GNUNET_PeerIdentity new_successor;
4779 struct GNUNET_HashCode trail_id;
4780 struct GNUNET_PeerIdentity next_hop;
4781 struct FriendInfo *target_friend;
4784 uint32_t trail_length;
4786 msize = ntohs (message->size);
4787 /* We have the trail to reach from source to new successor. */
4788 if (msize < sizeof (struct PeerNotifyNewSuccessorMessage))
4790 GNUNET_break_op (0);
4794 nsm = (const struct PeerNotifyNewSuccessorMessage *) message;
4795 trail_length = (msize - sizeof (struct PeerNotifyNewSuccessorMessage))/
4796 sizeof (struct GNUNET_PeerIdentity);
4797 if ((msize - sizeof (struct PeerTrailRejectionMessage)) %
4798 sizeof (struct GNUNET_PeerIdentity) != 0)
4800 GNUNET_break_op (0);
4804 trail = (struct GNUNET_PeerIdentity *) &nsm[1];
4805 source = nsm->source_peer;
4806 new_successor = nsm->new_successor;
4807 trail_id = nsm->trail_id;
4809 //FIXME: add a check to make sure peer is correct.
4811 /* I am the new_successor to source_peer. */
4812 if ( 0 == GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &new_successor))
4814 GDS_ROUTING_add (trail_id, *peer, my_identity);
4815 compare_and_update_predecessor (source, trail, trail_length);
4819 /* I am part of trail to reach to successor. */
4820 my_index = search_my_index (trail, trail_length);
4823 GNUNET_break_op (0);
4824 return GNUNET_SYSERR;
4826 if (trail_length == my_index)
4827 next_hop = new_successor;
4829 next_hop = trail[my_index + 1];
4831 /* Add an entry in routing table for trail from source to its new successor. */
4832 GNUNET_assert (GNUNET_OK == GDS_ROUTING_add (trail_id, *peer, next_hop));
4833 GNUNET_assert (NULL !=
4835 GNUNET_CONTAINER_multipeermap_get (friend_peermap, &next_hop)));
4836 GDS_NEIGHBOURS_send_notify_new_successor (source, new_successor, trail,
4838 trail_id, target_friend);
4845 * 1. Set the congestion timeout for the friend which is congested and sent
4847 * 2. Check if you were the source of this message
4848 * 2.1 If yes then exit. find_finger_trail_task is scheduled periodically.
4849 * So, we will eventually send a new request to setup trail to finger.
4850 * 2. Check if you can handle more trails through you. (Routing table space)
4851 * 2.1 If not then you are congested. Set your congestion time and pass this
4852 * message to peer before you in the trail setup so far.
4853 * 2.2 If yes, the call find_successor(). It will give you the next hop to
4854 * pass this message.
4855 * 2.2.1 If you are the final destination, then send back the trail setup
4857 * 2.2.2 If you are not the final dest, then send trail setup message to
4859 * Core handler for P2P trail rejection message
4860 * @param cls closure
4861 * @param message message
4862 * @param peer peer identity this notification is about
4863 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
4866 handle_dht_p2p_trail_setup_rejection (void *cls,
4867 const struct GNUNET_PeerIdentity *peer,
4868 const struct GNUNET_MessageHeader *message)
4870 const struct PeerTrailRejectionMessage *trail_rejection;
4871 unsigned int trail_length;
4872 const struct GNUNET_PeerIdentity *trail_peer_list;
4873 struct FriendInfo *target_friend;
4874 struct GNUNET_TIME_Relative congestion_timeout;
4875 struct GNUNET_HashCode trail_id;
4876 struct GNUNET_PeerIdentity next_destination;
4877 struct GNUNET_HashCode new_intermediate_trail_id;
4878 struct GNUNET_PeerIdentity next_peer;
4879 struct GNUNET_PeerIdentity source;
4880 struct GNUNET_PeerIdentity *next_hop;
4881 uint64_t ultimate_destination_finger_value;
4882 unsigned int is_predecessor;
4885 msize = ntohs (message->size);
4886 /* We are passing the trail setup so far. */
4887 if (msize < sizeof (struct PeerTrailRejectionMessage))
4889 GNUNET_break_op (0);
4893 trail_rejection = (const struct PeerTrailRejectionMessage *) message;
4894 trail_length = (msize - sizeof (struct PeerTrailRejectionMessage))/
4895 sizeof (struct GNUNET_PeerIdentity);
4896 if ((msize - sizeof (struct PeerTrailRejectionMessage)) %
4897 sizeof (struct GNUNET_PeerIdentity) != 0)
4899 GNUNET_break_op (0);
4903 trail_peer_list = (const struct GNUNET_PeerIdentity *)&trail_rejection[1];
4904 is_predecessor = ntohl (trail_rejection->is_predecessor);
4905 congestion_timeout = trail_rejection->congestion_time;
4906 source = trail_rejection->source_peer;
4907 trail_id = trail_rejection->trail_id;
4908 ultimate_destination_finger_value =
4909 GNUNET_ntohll (trail_rejection->ultimate_destination_finger_value);
4911 /* First set the congestion time of the friend that sent you this message. */
4912 GNUNET_assert (NULL !=
4914 GNUNET_CONTAINER_multipeermap_get (friend_peermap, peer)));
4915 target_friend->congestion_timestamp =
4916 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(),
4917 congestion_timeout);
4919 /* I am the source peer which wants to setup the trail. Do nothing.
4920 * send_find_finger_trail_task is scheduled periodically.*/
4921 if(0 == (GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &source)))
4924 /* If I am congested then pass this message to peer before me in trail. */
4925 if(GNUNET_YES == GDS_ROUTING_threshold_reached())
4927 struct GNUNET_PeerIdentity *new_trail;
4928 unsigned int new_trail_length;
4930 /* Remove yourself from the trail setup so far. */
4931 if (trail_length == 1)
4934 new_trail_length = 0;
4939 memcpy (&next_hop , &trail_peer_list[trail_length - 2],
4940 sizeof (struct GNUNET_PeerIdentity));
4942 /* Remove myself from the trail. */
4943 new_trail_length = trail_length -1;
4944 new_trail = GNUNET_malloc (new_trail_length * sizeof (struct GNUNET_PeerIdentity));
4945 memcpy (new_trail, trail_peer_list, new_trail_length * sizeof (struct GNUNET_PeerIdentity));
4948 GNUNET_assert (NULL !=
4950 GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop)));
4951 GDS_NEIGHBOURS_send_trail_rejection (source,
4952 ultimate_destination_finger_value,
4953 my_identity, is_predecessor,
4954 new_trail,new_trail_length,trail_id,
4955 target_friend, CONGESTION_TIMEOUT);
4956 GNUNET_free (new_trail);
4960 /* Look for next_hop to pass the trail setup message */
4961 next_hop = find_successor (ultimate_destination_finger_value,
4963 &new_intermediate_trail_id,
4966 /* Am I the final destination? */
4967 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (next_hop, &my_identity)))
4969 /* Add an entry in routing table only
4970 * 1. If I am not the original source which sent the request for trail setup
4971 FIXME: check that you always add trail entry even if your finger is
4973 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&source, &my_identity))
4974 GNUNET_assert (GNUNET_YES == GDS_ROUTING_add (trail_id, *peer, my_identity));
4976 if (0 == trail_length)
4979 next_peer = trail_peer_list[trail_length-1];
4981 GNUNET_assert (NULL !=
4983 GNUNET_CONTAINER_multipeermap_get (friend_peermap, &next_peer)));
4984 GDS_NEIGHBOURS_send_trail_setup_result (source,
4986 target_friend, trail_length,
4989 ultimate_destination_finger_value,
4994 struct GNUNET_PeerIdentity peer_list[trail_length + 1];
4996 memcpy (peer_list, trail_peer_list, trail_length * sizeof (struct GNUNET_PeerIdentity));
4997 peer_list[trail_length] = my_identity;
4999 GNUNET_assert (NULL !=
5001 GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop)));
5002 GDS_NEIGHBOURS_send_trail_setup (source,
5003 ultimate_destination_finger_value,
5005 target_friend, trail_length + 1, peer_list,
5006 is_predecessor, trail_id,
5007 &new_intermediate_trail_id);
5009 GNUNET_free (next_hop);
5015 * If you are the new first friend, then update prev hop to source of this message
5016 * else get the next hop and pass this message forward to ultimately reach
5018 * Core handle for p2p trail tear compression messages.
5019 * @param cls closure
5020 * @param message message
5021 * @param peer peer identity this notification is about
5022 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
5025 handle_dht_p2p_trail_compression (void *cls, const struct GNUNET_PeerIdentity *peer,
5026 const struct GNUNET_MessageHeader *message)
5028 const struct PeerTrailCompressionMessage *trail_compression;
5029 struct GNUNET_PeerIdentity *next_hop;
5030 struct FriendInfo *target_friend;
5031 struct GNUNET_HashCode trail_id;
5034 msize = ntohs (message->size);
5035 /* Here we pass only the trail id. */
5036 if (msize != sizeof (struct PeerTrailCompressionMessage))
5038 GNUNET_break_op (0);
5042 trail_compression = (const struct PeerTrailCompressionMessage *) message;
5043 trail_id = trail_compression->trail_id;
5044 //FIXME: again check if peer is the correct peer. same logic as
5045 //trail teardown make a generic function.
5047 /* Am I the new first friend to reach to finger of this trail. */
5048 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (&(trail_compression->new_first_friend),
5051 GNUNET_assert (NULL != GNUNET_CONTAINER_multipeermap_get (friend_peermap, &trail_compression->source_peer));
5052 /* Update your prev hop to source of this message. */
5053 GNUNET_assert (GNUNET_SYSERR !=
5054 (GDS_ROUTING_update_trail_prev_hop (trail_id,
5055 trail_compression->source_peer)));
5058 //GDS_ROUTING_test_print();
5059 /* Pass the message to next hop to finally reach to new_first_friend. */
5060 next_hop = GDS_ROUTING_get_next_hop (trail_id, GDS_ROUTING_SRC_TO_DEST);
5061 if (NULL == next_hop)
5067 GNUNET_assert (NULL != (target_friend =
5068 GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop)));
5069 GDS_NEIGHBOURS_send_trail_compression (trail_compression->source_peer,
5071 trail_compression->new_first_friend,
5078 * Remove entry from your own routing table and pass the message to next
5079 * peer in the trail.
5080 * Core handler for trail teardown message.
5081 * @param cls closure
5082 * @param message message
5083 * @param peer sender of this messsage.
5084 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
5087 handle_dht_p2p_trail_teardown (void *cls, const struct GNUNET_PeerIdentity *peer,
5088 const struct GNUNET_MessageHeader *message)
5090 const struct PeerTrailTearDownMessage *trail_teardown;
5091 enum GDS_ROUTING_trail_direction trail_direction;
5092 struct GNUNET_HashCode trail_id;
5093 struct GNUNET_PeerIdentity *next_hop;
5096 msize = ntohs (message->size);
5098 /* Here we pass only the trail id. */
5099 if (msize != sizeof (struct PeerTrailTearDownMessage))
5101 GNUNET_break_op (0);
5105 trail_teardown = (const struct PeerTrailTearDownMessage *) message;
5106 trail_direction = ntohl (trail_teardown->trail_direction);
5107 trail_id = trail_teardown->trail_id;
5109 /* Check if peer is the real peer from which we should get this message.*/
5110 /* Get the prev_hop for this trail by getting the next hop in opposite direction. */
5111 /* FIXME: is using negation of trail direction correct. */
5113 GNUNET_assert (NULL != (prev_hop =
5114 GDS_ROUTING_get_next_hop (trail_id, !trail_direction)));
5115 if (0 != GNUNET_CRYPTO_cmp_peer_identity (prev_hop, peer))
5118 return GNUNET_SYSERR;
5122 next_hop = GDS_ROUTING_get_next_hop (trail_id, trail_direction);
5124 if (NULL == next_hop)
5127 return GNUNET_SYSERR;
5130 GNUNET_assert (GNUNET_YES == GDS_ROUTING_remove_trail (trail_id));
5132 /* I am the next hop, which means I am the final destination. */
5133 if (0 == GNUNET_CRYPTO_cmp_peer_identity (next_hop, &my_identity))
5139 /* If not final destination, then send a trail teardown message to next hop.*/
5140 GNUNET_assert (NULL != GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop));
5141 GDS_NEIGHBOURS_send_trail_teardown (trail_id, trail_direction, *next_hop);
5149 * Add an entry in your routing table. If you are destination of this message
5150 * then next_hop in routing table should be your own identity. If you are NOT
5151 * destination, then get the next hop and forward message to it.
5152 * Core handle for p2p add trail message.
5153 * @param cls closure
5154 * @param message message
5155 * @param peer peer identity this notification is about
5156 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
5159 handle_dht_p2p_add_trail (void *cls, const struct GNUNET_PeerIdentity *peer,
5160 const struct GNUNET_MessageHeader *message)
5162 const struct PeerAddTrailMessage *add_trail;
5163 const struct GNUNET_PeerIdentity *trail;
5164 struct GNUNET_HashCode trail_id;
5165 struct GNUNET_PeerIdentity destination_peer;
5166 struct GNUNET_PeerIdentity source_peer;
5167 struct GNUNET_PeerIdentity next_hop;
5168 unsigned int trail_length;
5169 unsigned int my_index;
5172 msize = ntohs (message->size);
5173 /* In this message we pass the whole trail from source to destination as we
5174 * are adding that trail.*/
5175 if (msize < sizeof (struct PeerAddTrailMessage))
5177 GNUNET_break_op (0);
5181 add_trail = (const struct PeerAddTrailMessage *) message;
5182 trail_length = (msize - sizeof (struct PeerAddTrailMessage))/
5183 sizeof (struct GNUNET_PeerIdentity);
5184 if ((msize - sizeof (struct PeerAddTrailMessage)) %
5185 sizeof (struct GNUNET_PeerIdentity) != 0)
5187 GNUNET_break_op (0);
5191 trail = (const struct GNUNET_PeerIdentity *)&add_trail[1];
5192 destination_peer = add_trail->destination_peer;
5193 source_peer = add_trail->source_peer;
5194 trail_id = add_trail->trail_id;
5196 //FIXME: add a check that sender peer is not malicious. Make it a generic
5197 // function so that it can be used in all other functions where we need the
5198 // same functionality.
5200 /* I am not the destination of the trail. */
5201 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &destination_peer))
5203 struct FriendInfo *target_friend;
5205 /* Get my location in the trail. */
5206 my_index = search_my_index (trail, trail_length);
5209 GNUNET_break_op (0);
5210 return GNUNET_SYSERR;
5214 next_hop = source_peer;
5216 next_hop = trail[trail_length - 1];
5217 /* FIXME: check that you always add trail entry even if your finger is
5219 /* Add in your routing table. */
5220 GNUNET_assert (GNUNET_OK == GDS_ROUTING_add (trail_id, next_hop, *peer));
5221 GNUNET_assert (NULL !=
5223 GNUNET_CONTAINER_multipeermap_get (friend_peermap, &next_hop)));
5224 GDS_NEIGHBOURS_send_add_trail (source_peer, destination_peer, trail_id,
5225 trail, trail_length, target_friend);
5228 /* FIXME: check that you always add trail entry even if your finger is
5230 /* I am the destination. Add an entry in routing table. */
5231 GNUNET_assert (GNUNET_OK == GDS_ROUTING_add (trail_id, *peer, my_identity));
5237 * Free the finger trail in which the first friend to reach to a finger is
5238 * disconnected_friend. Also remove entry from routing table for that particular
5240 * @param disconnected_friend PeerIdentity of friend which got disconnected
5241 * @param remove_finger Finger whose trail we need to check if it has
5242 * disconnected_friend as the first hop.
5243 * @return Total number of trails in which disconnected_friend was the first
5247 remove_matching_trails (const struct GNUNET_PeerIdentity *disconnected_friend,
5248 struct FingerInfo *remove_finger)
5250 unsigned int matching_trails_count;
5253 /* Number of trails with disconnected_friend as the first hop in the trail
5254 * to reach from me to remove_finger, NOT including endpoints. */
5255 matching_trails_count = 0;
5257 /* Iterate over all the trails of finger. */
5258 for (i = 0; i < remove_finger->trails_count; i++)
5260 struct Trail *trail;
5261 trail = &remove_finger->trail_list[i];
5263 if (GNUNET_NO == trail->is_present)
5266 /*FIXME: This is here to ensure that no finger which is a friend should ever call this
5267 function. remove afterwards.*/
5268 GNUNET_assert (trail->trail_length > 0);
5270 /* First friend to reach to finger is disconnected_peer. */
5271 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&trail->trail_head->peer,
5272 disconnected_friend))
5274 struct GNUNET_PeerIdentity *next_hop;
5275 struct FriendInfo *remove_friend;
5277 remove_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
5278 disconnected_friend);
5279 remove_friend->trails_count--;
5280 next_hop = GDS_ROUTING_get_next_hop (trail->trail_id, GDS_ROUTING_SRC_TO_DEST);
5281 GNUNET_assert (0 == (GNUNET_CRYPTO_cmp_peer_identity (disconnected_friend,
5283 matching_trails_count++;
5284 GNUNET_assert (GNUNET_YES == GDS_ROUTING_remove_trail (trail->trail_id));
5287 trail->is_present = GNUNET_NO;
5290 return matching_trails_count;
5295 * Iterate over finger_table entries.
5296 * 0. Ignore finger which is my_identity or if no valid entry present at
5297 * that finger index.
5298 * 1. If disconnected_friend is a finger, then remove the routing entry from
5299 your own table. Free the trail.
5300 * 2. Check if disconnected_friend is the first friend in the trail to reach to a finger.
5301 * 2.1 Remove all the trails and entry from routing table in which disconnected
5302 * friend is the first friend in the trail. If disconnected_friend is the
5303 * first friend in all the trails to reach finger, then remove the finger.
5304 * @param disconnected_friend Peer identity of friend which got disconnected.
5307 remove_matching_fingers (const struct GNUNET_PeerIdentity *disconnected_peer)
5309 struct FingerInfo *remove_finger;
5310 struct FriendInfo *remove_friend;
5311 int removed_trails_count;
5314 /* Iterate over finger table entries. */
5315 for (i = 0; i < MAX_FINGERS; i++)
5317 remove_finger = &finger_table[i];
5319 /* No finger stored at this trail index. */
5320 if (GNUNET_NO == remove_finger->is_present)
5323 /* I am my own finger, then ignore this finger. */
5324 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&remove_finger->finger_identity,
5328 /* Is disconnected_peer a finger? */
5329 if (0 == GNUNET_CRYPTO_cmp_peer_identity (disconnected_peer,
5330 &remove_finger->finger_identity))
5332 struct GNUNET_PeerIdentity *next_hop;
5333 struct GNUNET_HashCode trail_id;
5335 GNUNET_assert (GNUNET_YES == (remove_finger->trail_list[0].is_present));
5336 /* FIXME: I am adding this check just to ensure that for a finger which
5337 is also a friend, we are storing only one trail and not more. REMOVE
5339 GNUNET_assert (1 == remove_finger->trails_count);
5340 trail_id = remove_finger->trail_list[0].trail_id;
5342 GNUNET_assert (NULL !=
5344 GDS_ROUTING_get_next_hop (trail_id, GDS_ROUTING_SRC_TO_DEST)));
5345 /* As finger is a friend, you have no trail as such but you have entry in routing
5346 * table of source and dest, so next_hop will be same as finger identity. */
5348 (GNUNET_CRYPTO_cmp_peer_identity (next_hop,
5349 &remove_finger->finger_identity)));
5350 GNUNET_assert (GNUNET_YES == GDS_ROUTING_remove_trail (trail_id));
5351 remove_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
5353 remove_friend->trails_count--;
5354 remove_finger->is_present = GNUNET_NO;
5355 memset ((void *)&finger_table[i], 0, sizeof (finger_table[i]));
5359 /* If finger is a friend but not disconnected_friend, then continue. */
5360 if (NULL != GNUNET_CONTAINER_multipeermap_get (friend_peermap,
5361 &remove_finger->finger_identity))
5364 /* Iterate over the list of trails to reach remove_finger. Check if
5365 * disconnected_friend makis the first friend in any of the trail. */
5366 removed_trails_count = remove_matching_trails (disconnected_peer,
5369 /* All the finger trails had disconnected_friend as the first friend,
5370 * so free the finger. */
5371 if (removed_trails_count == remove_finger->trails_count)
5373 remove_finger->is_present = GNUNET_NO;
5374 memset ((void *)&finger_table[i], 0, sizeof (finger_table[i]));
5381 * Method called whenever a peer disconnects.
5383 * @param cls closure
5384 * @param peer peer identity this notification is about
5387 handle_core_disconnect (void *cls,
5388 const struct GNUNET_PeerIdentity *peer)
5390 struct FriendInfo *remove_friend;
5392 /* If disconnected to own identity, then return. */
5393 if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
5396 GNUNET_assert (NULL != (remove_friend =
5397 GNUNET_CONTAINER_multipeermap_get (friend_peermap, peer)));
5399 /* Remove fingers with peer as first friend or if peer is a finger. */
5400 remove_matching_fingers (peer);
5402 /* Remove any trail from routing table of which peer is a part of. This function
5403 * internally sends a trail teardown message in the direction of which
5404 * disconnected peer is not part of. */
5405 GNUNET_assert (GNUNET_SYSERR != GDS_ROUTING_remove_trail_by_peer (peer));
5407 GNUNET_assert (0 == remove_friend->trails_count);
5409 /* Remove peer from friend_peermap. */
5410 GNUNET_assert (GNUNET_YES ==
5411 GNUNET_CONTAINER_multipeermap_remove (friend_peermap,
5415 if (0 != GNUNET_CONTAINER_multipeermap_size (friend_peermap))
5418 /* If there are no more friends in friend_peermap, then don't schedule
5419 * find_finger_trail_task. */
5420 if (GNUNET_SCHEDULER_NO_TASK != find_finger_trail_task)
5422 GNUNET_SCHEDULER_cancel (find_finger_trail_task);
5423 find_finger_trail_task = GNUNET_SCHEDULER_NO_TASK;
5432 * Method called whenever a peer connects.
5434 * @param cls closure
5435 * @param peer_identity peer identity this notification is about
5438 handle_core_connect (void *cls, const struct GNUNET_PeerIdentity *peer_identity)
5440 struct FriendInfo *friend;
5442 /* Check for connect to self message */
5443 if (0 == memcmp (&my_identity, peer_identity, sizeof (struct GNUNET_PeerIdentity)))
5446 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connected to %s\n", GNUNET_i2s (peer_identity));
5448 /* If peer already exists in our friend_peermap, then exit. */
5449 if (GNUNET_YES == GNUNET_CONTAINER_multipeermap_contains (friend_peermap,
5456 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# peers connected"), 1,
5459 friend = GNUNET_new (struct FriendInfo);
5460 friend->id = *peer_identity;
5462 GNUNET_assert (GNUNET_OK ==
5463 GNUNET_CONTAINER_multipeermap_put (friend_peermap,
5464 peer_identity, friend,
5465 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
5468 /* got a first connection, good time to start with FIND FINGER TRAIL requests...*/
5469 if (GNUNET_SCHEDULER_NO_TASK == find_finger_trail_task)
5470 find_finger_trail_task = GNUNET_SCHEDULER_add_now (&send_find_finger_trail_message, NULL);
5475 * To be called on core init/fail.
5477 * @param cls service closure
5478 * @param identity the public identity of this peer
5481 core_init (void *cls,
5482 const struct GNUNET_PeerIdentity *identity)
5484 my_identity = *identity;
5485 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
5486 "my_indentity = %s\n",GNUNET_i2s(&my_identity));
5491 * Initialize finger table entries.
5494 finger_table_init ()
5499 for(i = 0; i < MAX_FINGERS; i++)
5501 finger_table[i].is_present = GNUNET_NO;
5502 for (j = 0; j < MAXIMUM_TRAILS_PER_FINGER; j++)
5503 finger_table[i].trail_list[j].is_present = GNUNET_NO;
5504 memset ((void *)&finger_table[i], 0, sizeof (finger_table[i]));
5510 * Initialize neighbours subsystem.
5511 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
5514 GDS_NEIGHBOURS_init (void)
5516 static struct GNUNET_CORE_MessageHandler core_handlers[] = {
5517 {&handle_dht_p2p_put, GNUNET_MESSAGE_TYPE_XDHT_P2P_PUT, 0},
5518 {&handle_dht_p2p_get, GNUNET_MESSAGE_TYPE_XDHT_P2P_GET, 0},
5519 {&handle_dht_p2p_get_result, GNUNET_MESSAGE_TYPE_XDHT_P2P_GET_RESULT, 0},
5520 {&handle_dht_p2p_trail_setup, GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP, 0},
5521 {&handle_dht_p2p_trail_setup_result, GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP_RESULT, 0},
5522 {&handle_dht_p2p_verify_successor, GNUNET_MESSAGE_TYPE_XDHT_P2P_VERIFY_SUCCESSOR, 0},
5523 {&handle_dht_p2p_verify_successor_result, GNUNET_MESSAGE_TYPE_XDHT_P2P_VERIFY_SUCCESSOR_RESULT, 0},
5524 {&handle_dht_p2p_notify_new_successor, GNUNET_MESSAGE_TYPE_XDHT_P2P_NOTIFY_NEW_SUCCESSOR, 0},
5525 {&handle_dht_p2p_trail_setup_rejection, GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP_REJECTION, 0},
5526 {&handle_dht_p2p_trail_compression, GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_COMPRESSION,
5527 sizeof (struct PeerTrailCompressionMessage)},
5528 {&handle_dht_p2p_trail_teardown, GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_TEARDOWN,
5529 sizeof (struct PeerTrailTearDownMessage)},
5530 {&handle_dht_p2p_add_trail, GNUNET_MESSAGE_TYPE_XDHT_P2P_ADD_TRAIL, 0},
5535 GNUNET_CORE_connect (GDS_cfg, NULL, &core_init, &handle_core_connect,
5536 &handle_core_disconnect, NULL, GNUNET_NO, NULL,
5537 GNUNET_NO, core_handlers);
5538 if (NULL == core_api)
5539 return GNUNET_SYSERR;
5541 friend_peermap = GNUNET_CONTAINER_multipeermap_create (256, GNUNET_NO);
5542 finger_table_init ();
5549 * Shutdown neighbours subsystem.
5552 GDS_NEIGHBOURS_done (void)
5554 if (NULL == core_api)
5557 GNUNET_CORE_disconnect (core_api);
5560 GNUNET_assert (0 == GNUNET_CONTAINER_multipeermap_size (friend_peermap));
5561 GNUNET_CONTAINER_multipeermap_destroy (friend_peermap);
5562 friend_peermap = NULL;
5564 if (GNUNET_SCHEDULER_NO_TASK != find_finger_trail_task)
5567 GNUNET_SCHEDULER_cancel (find_finger_trail_task);
5568 find_finger_trail_task = GNUNET_SCHEDULER_NO_TASK;
5576 * @return my identity
5578 struct GNUNET_PeerIdentity
5579 GDS_NEIGHBOURS_get_my_id (void)