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;
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);
970 * Transmit all messages in the friend's message queue.
972 * @param peer message queue to process
975 process_friend_queue (struct FriendInfo *peer)
977 struct P2PPendingMessage *pending;
979 if (NULL == (pending = peer->head))
981 if (NULL != peer->th)
984 GNUNET_STATISTICS_update (GDS_stats,
986 ("# Bytes of bandwidth requested from core"),
987 ntohs (pending->msg->size), GNUNET_NO);
990 GNUNET_CORE_notify_transmit_ready (core_api, GNUNET_NO,
992 GNUNET_TIME_absolute_get_remaining
993 (pending->timeout), &peer->id,
994 ntohs (pending->msg->size),
995 &core_transmit_notify, peer);
996 GNUNET_break (NULL != peer->th);
1001 * Return friend corresponding to peer.
1006 GDS_NEIGHBOURS_get_friend (struct GNUNET_PeerIdentity peer)
1008 struct FriendInfo *friend;
1009 GNUNET_assert (NULL != (friend =
1010 GNUNET_CONTAINER_multipeermap_get (friend_peermap, &peer)));
1016 * Construct a trail setup message and forward it to target_friend
1017 * @param source_peer Peer which wants to setup the trail
1018 * @param ultimate_destination_finger_value Peer identity closest to this value
1019 * will be finger to @a source_peer
1020 * @param best_known_destination Best known destination (could be finger or friend)
1021 * which should get this message. In case it is
1022 * friend, then it is same as target_friend
1023 * @param target_friend Friend to which message is forwarded now.
1024 * @param trail_length Total number of peers in trail setup so far.
1025 * @param trail_peer_list Trail setup so far
1026 * @param is_predecessor Is @a source_peer looking for trail to a predecessor or not.
1027 * @param trail_id Unique identifier for the trail we are trying to setup.
1028 * @param intermediate_trail_id Trail id of intermediate trail to reach to
1029 * best_known_destination when its a finger. If not
1030 * used then set to 0.
1033 GDS_NEIGHBOURS_send_trail_setup (struct GNUNET_PeerIdentity source_peer,
1034 uint64_t ultimate_destination_finger_value,
1035 struct GNUNET_PeerIdentity best_known_destination,
1036 struct FriendInfo *target_friend,
1037 unsigned int trail_length,
1038 const struct GNUNET_PeerIdentity *trail_peer_list,
1039 unsigned int is_predecessor,
1040 struct GNUNET_HashCode trail_id,
1041 struct GNUNET_HashCode *intermediate_trail_id)
1043 struct P2PPendingMessage *pending;
1044 struct PeerTrailSetupMessage *tsm;
1045 struct GNUNET_PeerIdentity *peer_list;
1048 msize = sizeof (struct PeerTrailSetupMessage) +
1049 (trail_length * sizeof (struct GNUNET_PeerIdentity));
1051 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1057 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1059 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# P2P messages dropped due to full queue"),
1063 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1064 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1065 tsm = (struct PeerTrailSetupMessage *) &pending[1];
1066 pending->msg = &tsm->header;
1067 tsm->header.size = htons (msize);
1068 tsm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP);
1069 tsm->final_destination_finger_value = GNUNET_htonll (ultimate_destination_finger_value);
1070 tsm->source_peer = source_peer;
1071 tsm->best_known_destination = best_known_destination;
1072 tsm->is_predecessor = htonl (is_predecessor);
1073 tsm->trail_id = trail_id;
1075 if (NULL == intermediate_trail_id)
1076 memset (&tsm->intermediate_trail_id, 0, sizeof (tsm->intermediate_trail_id));
1078 tsm->intermediate_trail_id = *intermediate_trail_id;
1080 if (trail_length > 0)
1082 peer_list = (struct GNUNET_PeerIdentity *) &tsm[1];
1083 memcpy (peer_list, trail_peer_list, trail_length * sizeof(struct GNUNET_PeerIdentity));
1086 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1087 target_friend->pending_count++;
1088 process_friend_queue (target_friend);
1093 * Construct a trail setup result message and forward it to target friend.
1094 * @param querying_peer Peer which sent the trail setup request and should get
1096 * @param Finger Peer to which the trail has been setup to.
1097 * @param target_friend Friend to which this message should be forwarded.
1098 * @param trail_length Numbers of peers in the trail.
1099 * @param trail_peer_list Peers which are part of the trail from
1100 * querying_peer to Finger, NOT including them.
1101 * @param is_predecessor Is @a Finger predecessor to @a querying_peer ?
1102 * @param ultimate_destination_finger_value Value to which @a finger is the closest
1104 * @param trail_id Unique identifier of the trail.
1107 GDS_NEIGHBOURS_send_trail_setup_result (struct GNUNET_PeerIdentity querying_peer,
1108 struct GNUNET_PeerIdentity finger,
1109 struct FriendInfo *target_friend,
1110 unsigned int trail_length,
1111 const struct GNUNET_PeerIdentity *trail_peer_list,
1112 unsigned int is_predecessor,
1113 uint64_t ultimate_destination_finger_value,
1114 struct GNUNET_HashCode trail_id)
1116 struct P2PPendingMessage *pending;
1117 struct PeerTrailSetupResultMessage *tsrm;
1118 struct GNUNET_PeerIdentity *peer_list;
1121 msize = sizeof (struct PeerTrailSetupResultMessage) +
1122 (trail_length * sizeof (struct GNUNET_PeerIdentity));
1124 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1130 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1132 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# P2P messages dropped due to full queue"),
1136 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1137 pending->importance = 0;
1138 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1139 tsrm = (struct PeerTrailSetupResultMessage *) &pending[1];
1140 pending->msg = &tsrm->header;
1141 tsrm->header.size = htons (msize);
1142 tsrm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP_RESULT);
1143 tsrm->querying_peer = querying_peer;
1144 tsrm->finger_identity = finger;
1145 tsrm->is_predecessor = htonl (is_predecessor);
1146 tsrm->trail_id = trail_id;
1147 tsrm->ulitmate_destination_finger_value =
1148 GNUNET_htonll (ultimate_destination_finger_value);
1149 peer_list = (struct GNUNET_PeerIdentity *) &tsrm[1];
1150 if (trail_length > 0)
1152 memcpy (peer_list, trail_peer_list, trail_length * sizeof (struct GNUNET_PeerIdentity));
1154 /* Send the message to chosen friend. */
1155 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1156 target_friend->pending_count++;
1157 process_friend_queue (target_friend);
1162 * Send trail rejection message to target friend
1163 * @param source_peer Peer which is trying to setup the trail.
1164 * @param ultimate_destination_finger_value Peer closest to this value will be
1165 * @a source_peer's finger
1166 * @param congested_peer Peer which sent this message as it is congested.
1167 * @param is_predecessor Is source_peer looking for trail to a predecessor or not.
1168 * @param trail_peer_list Trails seen so far in trail setup before getting rejected
1169 * by congested_peer. This does NOT include @a source_peer
1170 * and congested_peer.
1171 * @param trail_length Total number of peers in trail_peer_list, NOT including
1172 * @a source_peer and @a congested_peer
1173 * @param trail_id Unique identifier of this trail.
1174 * @param congestion_timeout Duration given by congested peer as an estimate of
1175 * how long it may remain congested.
1178 GDS_NEIGHBOURS_send_trail_rejection (struct GNUNET_PeerIdentity source_peer,
1179 uint64_t ultimate_destination_finger_value,
1180 struct GNUNET_PeerIdentity congested_peer,
1181 unsigned int is_predecessor,
1182 const struct GNUNET_PeerIdentity *trail_peer_list,
1183 unsigned int trail_length,
1184 struct GNUNET_HashCode trail_id,
1185 struct FriendInfo *target_friend,
1186 const struct GNUNET_TIME_Relative congestion_timeout)
1188 struct PeerTrailRejectionMessage *trm;
1189 struct P2PPendingMessage *pending;
1190 struct GNUNET_PeerIdentity *peer_list;
1193 msize = sizeof (struct PeerTrailRejectionMessage) +
1194 (trail_length * sizeof (struct GNUNET_PeerIdentity));
1196 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1202 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1204 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# P2P messages dropped due to full queue"),
1208 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1209 pending->importance = 0;
1210 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1211 trm = (struct PeerTrailRejectionMessage *)&pending[1];
1212 pending->msg = &trm->header;
1213 trm->header.size = htons (msize);
1214 trm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP_REJECTION);
1215 trm->source_peer = source_peer;
1216 trm->congested_peer = congested_peer;
1217 trm->congestion_time = congestion_timeout;
1218 trm->is_predecessor = htonl (is_predecessor);
1219 trm->trail_id = trail_id;
1220 trm->ultimate_destination_finger_value =
1221 GNUNET_htonll (ultimate_destination_finger_value);
1223 peer_list = (struct GNUNET_PeerIdentity *) &trm[1];
1224 if (trail_length > 0)
1226 memcpy (peer_list, trail_peer_list, trail_length * sizeof (struct GNUNET_PeerIdentity));
1229 /* Send the message to chosen friend. */
1230 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1231 target_friend->pending_count++;
1232 process_friend_queue (target_friend);
1237 * Construct a verify successor message and forward it to target_friend.
1238 * @param source_peer Peer which wants to verify its successor.
1239 * @param successor Peer which is @a source_peer's current successor.
1240 * @param trail_id Unique Identifier of trail from @a source_peer to @a successor,
1241 * NOT including them.
1242 * @param trail List of peers which are part of trail to reach from @a source_peer
1243 * to @a successor, NOT including them.
1244 * @param trail_length Total number of peers in @a trail.
1245 * @param target_friend Next friend to get this message.
1248 GDS_NEIGHBOURS_send_verify_successor_message (struct GNUNET_PeerIdentity source_peer,
1249 struct GNUNET_PeerIdentity successor,
1250 struct GNUNET_HashCode trail_id,
1251 struct GNUNET_PeerIdentity *trail,
1252 unsigned int trail_length,
1253 struct FriendInfo *target_friend)
1255 struct PeerVerifySuccessorMessage *vsm;
1256 struct P2PPendingMessage *pending;
1257 struct GNUNET_PeerIdentity *peer_list;
1260 msize = sizeof (struct PeerVerifySuccessorMessage);
1261 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1267 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1269 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# P2P messages dropped due to full queue"),
1273 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1274 pending->importance = 0; /* FIXME */
1275 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1276 vsm = (struct PeerVerifySuccessorMessage *) &pending[1];
1277 pending->msg = &vsm->header;
1278 vsm->header.size = htons (msize);
1279 vsm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_VERIFY_SUCCESSOR);
1280 vsm->source_peer = source_peer;
1281 vsm->successor = successor;
1282 vsm->trail_id = trail_id;
1284 if (trail_length > 0)
1286 peer_list = (struct GNUNET_PeerIdentity *) &vsm[1];
1287 memcpy (peer_list, trail, trail_length * sizeof (struct GNUNET_PeerIdentity));
1290 /* Send the message to chosen friend. */
1291 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
1292 target_friend->pending_count++;
1293 process_friend_queue (target_friend);
1298 * FIXME: In every function we pass target friend except for this one.
1299 * so, either change everything or this one. also, should se just store
1300 * the pointer to friend in routing table rather than gnunet_peeridentity.
1301 * if yes then we should keep friend info in.h andmake lot of changes.
1302 * Construct a trail teardown message and forward it to target friend.
1303 * @param trail_id Unique identifier of the trail.
1304 * @param trail_direction Direction of trail.
1305 * @param target_friend Friend to get this message.
1308 GDS_NEIGHBOURS_send_trail_teardown (struct GNUNET_HashCode trail_id,
1309 unsigned int trail_direction,
1310 struct GNUNET_PeerIdentity *peer)
1312 struct PeerTrailTearDownMessage *ttdm;
1313 struct P2PPendingMessage *pending;
1314 struct FriendInfo *target_friend;
1317 msize = sizeof (struct PeerTrailTearDownMessage);
1319 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1325 GNUNET_assert (NULL != (target_friend =
1326 GNUNET_CONTAINER_multipeermap_get (friend_peermap, peer)));
1328 if (target_friend->pending_count >= MAXIMUM_PENDING_PER_FRIEND)
1330 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# P2P messages dropped due to full queue"),
1334 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
1335 pending->importance = 0; /* FIXME */
1336 pending->timeout = GNUNET_TIME_relative_to_absolute (GET_TIMEOUT);
1337 ttdm = (struct PeerTrailTearDownMessage *) &pending[1];
1338 pending->msg = &ttdm->header;
1339 ttdm->header.size = htons (msize);
1340 ttdm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_TEARDOWN);
1341 ttdm->trail_id = trail_id;
1342 ttdm->trail_direction = htonl (trail_direction);
1344 /* 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?
1663 // we do it when we get from the network.
1665 if (peer1_value == value)
1670 if (peer2_value == value)
1675 if (peer2_value < peer1_value)
1677 if ((peer2_value < value) && (value < peer1_value))
1681 else if (((peer1_value < value) && (value < PEER_IDENTITES_WRAP_AROUND)) ||
1682 ((0 < value) && (value < peer2_value)))
1688 if (peer1_value < peer2_value)
1690 if ((peer1_value < value) && (value < peer2_value))
1694 else if (((peer2_value < value) && (value < PEER_IDENTITES_WRAP_AROUND)) ||
1695 ((0 < value) && (value < peer1_value)))
1705 * Select closest predecessor to value.
1706 * @param peer1 First peer
1707 * @param peer2 Second peer
1708 * @param value Value to be compare
1709 * @return Peer which precedes value in the network.
1711 static struct GNUNET_PeerIdentity *
1712 select_closest_predecessor (struct GNUNET_PeerIdentity *peer1,
1713 struct GNUNET_PeerIdentity *peer2,
1716 uint64_t peer1_value;
1717 uint64_t peer2_value;
1719 memcpy (&peer1_value, peer1, sizeof (uint64_t));
1720 memcpy (&peer2_value, peer2, sizeof (uint64_t));
1721 peer1_value = GNUNET_ntohll (peer1_value);
1722 peer2_value = GNUNET_ntohll (peer2_value);
1724 if (peer1_value == value)
1727 if (peer2_value == value)
1730 if (peer1_value < peer2_value)
1732 if ((peer1_value < value) && (value < peer2_value))
1734 else if (((peer2_value < value) && (value < PEER_IDENTITES_WRAP_AROUND)) ||
1735 ((PEER_IDENTITES_WRAP_AROUND > value) && (value < peer1_value)))
1739 if (peer2_value < peer1_value)
1741 if ((peer2_value < value) && (value < peer1_value))
1743 else if (((peer1_value < value) && (value < PEER_IDENTITES_WRAP_AROUND)) ||
1744 ((PEER_IDENTITES_WRAP_AROUND > value) && (value < peer2_value)))
1752 * Select the closest peer among two peers (which should not be same)
1753 * with respect to value and finger_table_index
1754 * NOTE: peer1 != peer2
1755 * @param peer1 First peer
1756 * @param peer2 Second peer
1757 * @param value Value relative to which we find the closest
1758 * @param is_predecessor Is value a predecessor or any other finger.
1759 * @return Closest peer among two peers.
1761 static struct GNUNET_PeerIdentity *
1762 select_closest_peer (struct GNUNET_PeerIdentity *peer1,
1763 struct GNUNET_PeerIdentity *peer2,
1765 unsigned int is_predecessor)
1767 struct GNUNET_PeerIdentity *closest_peer;
1769 if (1 == is_predecessor)
1770 closest_peer = select_closest_predecessor (peer1, peer2, value);
1772 closest_peer = select_closest_finger (peer1, peer2, value);
1774 return closest_peer;
1779 * Iterate over the list of all the trails of a finger. In case the first
1780 * friend to reach the finger has reached trail threshold or is congested,
1781 * then don't select it. In case there multiple available good trails to reach
1782 * to Finger, choose the one with shortest trail length.
1783 * Note: We use length as parameter. But we can use any other suitable parameter
1785 * @param finger Finger
1786 * @return struct Selected_Finger_Trail which contains the first friend , trail id
1787 * and trail length. NULL in case none of the trails are free.
1789 static struct Selected_Finger_Trail *
1790 select_finger_trail (struct FingerInfo *finger)
1792 struct FriendInfo *friend;
1793 struct Trail *iterator;
1794 struct Selected_Finger_Trail *finger_trail;
1796 unsigned int flag = 0;
1799 finger_trail = GNUNET_new (struct Selected_Finger_Trail);
1801 /* It can never happen that we have a finger (which is not a friend or my identity),
1802 and we don't have a trail to reach to it. */
1803 GNUNET_assert (finger->trails_count > 0);
1805 for (i = 0; i < finger->trails_count; i++)
1807 iterator = &finger->trail_list[i];
1809 /* No trail stored at this index. */
1810 if (GNUNET_NO == iterator->is_present)
1813 friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
1814 &iterator->trail_head->peer);
1816 /* First friend to reach trail is not free. */
1817 if (GNUNET_YES == is_friend_congested (friend))
1822 /* This is the first time we enter the loop. Set finger trail length to
1823 * trail length of this trail. */
1827 finger_trail->trail_length = iterator->trail_length;
1829 else if (finger_trail->trail_length > iterator->trail_length)
1831 /* Check if the trail length of this trail is least seen so far. If yes then
1832 set finger_trail to this trail.*/
1833 finger_trail->friend = *friend;
1834 finger_trail->trail_id = iterator->trail_id;
1835 finger_trail->trail_length = iterator->trail_length;
1839 /* All the first friend in all the trails to reach to finger are either
1840 congested or have crossed trail threshold. */
1841 if (j == finger->trails_count)
1844 return finger_trail;
1849 * Compare FINGER entry with current successor. If finger's first friend of all
1850 * its trail is not congested and has not crossed trail threshold, then check
1851 * if finger peer identity is closer to final_destination_finger_value than
1852 * current_successor. If yes then update current_successor.
1853 * @param current_successor[in/out]
1856 static struct Closest_Peer *
1857 compare_finger_and_current_successor (struct Closest_Peer *current_closest_peer)
1859 struct FingerInfo *finger;
1860 struct FriendInfo *friend;
1861 struct GNUNET_PeerIdentity *closest_peer;
1862 struct Selected_Finger_Trail *finger_trail;
1865 /* Iterate over finger table. */
1866 for (i = 0; i < MAX_FINGERS; i++)
1868 finger = &finger_table[i];
1870 /* No valid entry at this index, go to next element.*/
1871 if (GNUNET_NO == finger->is_present)
1874 /* If my identity is same as current closest peer then don't consider me*/
1876 GNUNET_CRYPTO_cmp_peer_identity (&finger->finger_identity,
1877 ¤t_closest_peer->best_known_destination))
1880 /* If I am my own finger, then ignore this finger. */
1881 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&finger->finger_identity,
1885 /* If finger is a friend, then do nothing. As we have already checked
1886 * for each friend in compare_friend_and_current_successor(). */
1888 (friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
1889 &finger->finger_identity)))
1892 /* We have a finger which not a friend, not my identity */
1893 /* Choose one of the trail to reach to finger. */
1894 finger_trail = select_finger_trail (finger);
1896 /* In case no trail found, ignore this finger. */
1897 if (NULL == finger_trail)
1900 closest_peer = select_closest_peer (&finger->finger_identity,
1901 ¤t_closest_peer->best_known_destination,
1902 current_closest_peer->destination_finger_value,
1903 current_closest_peer->is_predecessor);
1904 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&finger->finger_identity,
1907 current_closest_peer->best_known_destination = finger->finger_identity;
1908 current_closest_peer->next_hop = finger_trail->friend.id;
1909 current_closest_peer->trail_id = finger_trail->trail_id;
1913 return current_closest_peer;
1918 * Compare friend entry with current successor.
1919 * If friend identity and current_successor is same, then do nothing.
1920 * If friend is not congested and has not crossed trail threshold, then check
1921 * if friend peer identity is closer to final_destination_finger_value than
1922 * current_successor. If yes then update current_successor.
1923 * @param cls closure
1924 * @param key current public key
1925 * @param value struct Closest_Peer
1926 * @return #GNUNET_YES if we should continue to iterate,
1927 * #GNUNET_NO if not.
1930 compare_friend_and_current_closest_peer (void *cls,
1931 const struct GNUNET_PeerIdentity *key,
1934 struct FriendInfo *friend = value;
1935 struct Closest_Peer *current_closest_peer = cls;
1936 struct GNUNET_PeerIdentity *closest_peer;
1938 /* If friend is either congested or has crossed threshold, then don't consider
1940 if (GNUNET_YES == is_friend_congested (friend))
1943 /* If current_closest_peer and friend identity are same, then do nothing.*/
1945 GNUNET_CRYPTO_cmp_peer_identity (&friend->id,
1946 ¤t_closest_peer->best_known_destination))
1949 closest_peer = select_closest_peer (&friend->id,
1950 ¤t_closest_peer->best_known_destination,
1951 current_closest_peer->destination_finger_value,
1952 current_closest_peer->is_predecessor);
1954 /* Is friend the closest successor? */
1955 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&friend->id, closest_peer))
1957 current_closest_peer->best_known_destination = friend->id;
1958 current_closest_peer->next_hop = friend->id;
1966 * Initialize current_successor to my_identity.
1967 * @param my_identity My peer identity
1968 * @return current_successor
1970 static struct Closest_Peer *
1971 init_current_successor (struct GNUNET_PeerIdentity my_identity,
1972 uint64_t destination_finger_value,
1973 unsigned int is_predecessor)
1975 struct Closest_Peer *current_closest_peer;
1977 current_closest_peer = GNUNET_new (struct Closest_Peer);
1978 memset (¤t_closest_peer->trail_id, 0, sizeof (current_closest_peer->trail_id));
1979 current_closest_peer->destination_finger_value = destination_finger_value;
1980 current_closest_peer->is_predecessor = is_predecessor;
1981 current_closest_peer->next_hop = my_identity;
1982 current_closest_peer->best_known_destination = my_identity;
1984 return current_closest_peer;
1989 * Find the successor for destination_finger_value among my_identity, all my
1990 * friend and all my fingers. Don't consider friends or fingers which are either
1991 * congested or have crossed the threshold.
1992 * NOTE: In case a friend is also a finger, then it is always chosen as friend
1994 * @param destination_finger_value Peer closest to this value will be the next successor.
1995 * @param local_best_known_destination[out] Updated to my_identity if I am the
1996 * final destination. Updated to friend
1997 * identity in case a friend is successor,
1998 * updated to finger in case finger is the
2000 * @param new_intermediate_trail_id[out] In case a finger is the
2001 * @a local_best_known_destination,
2002 * then it is the trail to reach it. Else
2004 * @param is_predecessor Are we looking for predecessor or finger?
2005 * @return Next hop to reach to local_best_known_destination. In case my_identity
2006 * or a friend is a local_best_known_destination, then
2007 * next_hop = local_best_known_destination. Else
2008 * next_hop is the first friend to reach to finger (local_best_known_destination)
2010 static struct GNUNET_PeerIdentity *
2011 find_successor (uint64_t destination_finger_value,
2012 struct GNUNET_PeerIdentity *local_best_known_destination,
2013 struct GNUNET_HashCode *new_intermediate_trail_id,
2014 unsigned int is_predecessor)
2016 struct Closest_Peer *current_closest_peer;
2017 struct GNUNET_PeerIdentity *next_hop;
2019 /* Initialize current_successor to my_identity. */
2020 current_closest_peer = init_current_successor (my_identity,
2021 destination_finger_value,
2024 /* Compare each friend entry with current_successor and update current_successor
2025 * with friend if its closest. */
2028 GNUNET_CONTAINER_multipeermap_iterate (friend_peermap,
2029 &compare_friend_and_current_closest_peer,
2030 current_closest_peer));
2032 /* Compare each finger entry with current_successor and update current_successor
2033 * with finger if its closest. */
2034 compare_finger_and_current_successor (current_closest_peer);
2036 *local_best_known_destination = current_closest_peer->best_known_destination;
2037 new_intermediate_trail_id = ¤t_closest_peer->trail_id;
2038 next_hop = GNUNET_new (struct GNUNET_PeerIdentity);
2039 *next_hop = current_closest_peer->next_hop;
2046 * Construct a Put message and send it to target_peer.
2047 * @param key Key for the content
2048 * @param block_type Type of the block
2049 * @param options Routing options
2050 * @param desired_replication_level Desired replication count
2051 * @param best_known_dest Peer to which this message should reach eventually,
2052 * as it is best known destination to me.
2053 * @param intermediate_trail_id Trail id in case
2054 * @param target_peer Peer to which this message will be forwarded.
2055 * @param hop_count Number of hops traversed so far.
2056 * @param put_path_length Total number of peers in @a put_path
2057 * @param put_path Number of peers traversed so far
2058 * @param expiration_time When does the content expire
2059 * @param data Content to store
2060 * @param data_size Size of content @a data in bytes
2063 GDS_NEIGHBOURS_send_put (const struct GNUNET_HashCode *key,
2064 enum GNUNET_BLOCK_Type block_type,
2065 enum GNUNET_DHT_RouteOption options,
2066 uint32_t desired_replication_level,
2067 struct GNUNET_PeerIdentity *best_known_dest,
2068 struct GNUNET_HashCode *intermediate_trail_id,
2069 struct GNUNET_PeerIdentity *target_peer,
2071 uint32_t put_path_length,
2072 struct GNUNET_PeerIdentity *put_path,
2073 struct GNUNET_TIME_Absolute expiration_time,
2074 const void *data, size_t data_size)
2076 struct PeerPutMessage *ppm;
2077 struct P2PPendingMessage *pending;
2078 struct FriendInfo *target_friend;
2079 struct GNUNET_PeerIdentity *pp;
2080 struct GNUNET_PeerIdentity local_best_known_dest;
2083 msize = put_path_length * sizeof (struct GNUNET_PeerIdentity) + data_size +
2084 sizeof (struct PeerPutMessage);
2086 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
2088 put_path_length = 0;
2089 msize = data_size + sizeof (struct PeerPutMessage);
2092 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
2098 /* This is the first call made from clients file. So, we should search for the
2100 if (NULL == target_peer)
2103 struct GNUNET_PeerIdentity *next_hop;
2105 memcpy (&key_value, key, sizeof (uint64_t));
2106 next_hop = find_successor (key_value, &local_best_known_dest,
2107 intermediate_trail_id, GDS_FINGER_TYPE_NON_PREDECESSOR);
2108 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&local_best_known_dest, &my_identity))
2110 /* I am the destination but we have already done datacache_put in client file. */
2114 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop);
2115 GNUNET_free (next_hop);
2119 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, target_peer);
2121 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
2122 pending->timeout = expiration_time;
2123 ppm = (struct PeerPutMessage *) &pending[1];
2124 pending->msg = &ppm->header;
2125 ppm->header.size = htons (msize);
2126 ppm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_PUT);
2127 ppm->options = htonl (options);
2128 ppm->block_type = htonl (block_type);
2129 ppm->hop_count = htonl (hop_count + 1);
2130 ppm->desired_replication_level = htonl (desired_replication_level);
2131 ppm->put_path_length = htonl (put_path_length);
2132 ppm->expiration_time = GNUNET_TIME_absolute_hton (expiration_time);
2133 if (NULL == best_known_dest)
2134 ppm->best_known_destination = local_best_known_dest;
2136 ppm->best_known_destination = *best_known_dest;
2138 if (NULL == intermediate_trail_id)
2139 memset (&ppm->intermediate_trail_id, 0, sizeof (ppm->intermediate_trail_id));
2141 ppm->intermediate_trail_id = *intermediate_trail_id;
2142 pp = (struct GNUNET_PeerIdentity *) &ppm[1];
2143 if (put_path_length != 0)
2145 memcpy (pp, put_path,
2146 sizeof (struct GNUNET_PeerIdentity) * put_path_length);
2148 memcpy (&pp[put_path_length], data, data_size);
2149 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
2150 target_friend->pending_count++;
2151 process_friend_queue (target_friend);
2156 * Construct a Get message and send it to target_peer.
2157 * @param key Key for the content
2158 * @param block_type Type of the block
2159 * @param options Routing options
2160 * @param desired_replication_level Desired replication count
2161 * @param best_known_dest Peer which should get this message. Same as target peer
2162 * if best_known_dest is a friend else its a finger.
2163 * @param intermediate_trail_id Trail id to reach to @a best_known_dest
2164 * in case it is a finger else set to 0.
2165 * @param target_peer Peer to which this message will be forwarded.
2166 * @param hop_count Number of hops traversed so far.
2167 * @param data Content to store
2168 * @param data_size Size of content @a data in bytes
2169 * @param get_path_length Total number of peers in @a get_path
2170 * @param get_path Number of peers traversed so far
2173 GDS_NEIGHBOURS_send_get (const struct GNUNET_HashCode *key,
2174 enum GNUNET_BLOCK_Type block_type,
2175 enum GNUNET_DHT_RouteOption options,
2176 uint32_t desired_replication_level,
2177 const struct GNUNET_PeerIdentity *best_known_dest,
2178 struct GNUNET_HashCode *intermediate_trail_id,
2179 struct GNUNET_PeerIdentity *target_peer,
2181 uint32_t get_path_length,
2182 struct GNUNET_PeerIdentity *get_path)
2184 struct PeerGetMessage *pgm;
2185 struct P2PPendingMessage *pending;
2186 struct FriendInfo *target_friend;
2187 struct GNUNET_PeerIdentity local_best_known_dest;
2188 struct GNUNET_PeerIdentity *gp;
2191 msize = sizeof (struct PeerGetMessage) +
2192 (get_path_length * sizeof (struct GNUNET_PeerIdentity));
2194 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
2196 get_path_length = 0;
2197 msize = sizeof (struct PeerPutMessage);
2200 if (msize > GNUNET_SERVER_MAX_MESSAGE_SIZE)
2206 /* This is the first time we got request from our own client file. */
2207 if (NULL == target_peer)
2209 struct GNUNET_PeerIdentity *next_hop;
2212 memcpy (&key_value, key, sizeof (uint64_t)); //FIXME: endianess of key?
2214 /* Find the next destination to forward the packet. */
2215 next_hop = find_successor (key_value, &local_best_known_dest,
2216 intermediate_trail_id, GDS_FINGER_TYPE_NON_PREDECESSOR);
2218 /* I am the destination. I have the data. */
2219 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&my_identity,
2220 &local_best_known_dest))
2222 GDS_DATACACHE_handle_get (key,block_type, NULL, 0,
2223 NULL, 0, 1, &my_identity, NULL,&my_identity);
2229 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop);
2231 GNUNET_free (next_hop);
2235 local_best_known_dest = *best_known_dest;
2236 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, target_peer);
2239 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
2240 pending->importance = 0; /* FIXME */
2241 pgm = (struct PeerGetMessage *) &pending[1];
2242 pending->msg = &pgm->header;
2243 pgm->header.size = htons (msize);
2244 pgm->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_GET);
2245 pgm->get_path_length = htonl (get_path_length);
2246 pgm->best_known_destination = local_best_known_dest;
2248 if (NULL == intermediate_trail_id)
2249 memset (&pgm->intermediate_trail_id, 0, sizeof (pgm->intermediate_trail_id));
2251 pgm->intermediate_trail_id = *intermediate_trail_id;
2252 pgm->hop_count = htonl (hop_count + 1);
2254 if (get_path_length != 0)
2256 gp = (struct GNUNET_PeerIdentity *) &pgm[1];
2257 memcpy (gp, get_path, get_path_length * sizeof (struct GNUNET_PeerIdentity));
2259 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
2260 target_friend->pending_count++;
2261 process_friend_queue (target_friend);
2266 * Send the get result to requesting client.
2267 * @param key Key of the requested data.
2268 * @param type Block type
2269 * @param target_peer Next peer to forward the message to.
2270 * @param source_peer Peer which has the data for the key.
2271 * @param put_path_length Number of peers in @a put_path
2272 * @param put_path Path taken to put the data at its stored location.
2273 * @param get_path_length Number of peers in @a get_path
2274 * @param get_path Path taken to reach to the location of the key.
2275 * @param expiration When will this result expire?
2276 * @param data Payload to store
2277 * @param data_size Size of the @a data
2280 GDS_NEIGHBOURS_send_get_result (const struct GNUNET_HashCode *key,
2281 enum GNUNET_BLOCK_Type type,
2282 struct GNUNET_PeerIdentity *target_peer,
2283 struct GNUNET_PeerIdentity *source_peer,
2284 unsigned int put_path_length,
2285 const struct GNUNET_PeerIdentity *put_path,
2286 unsigned int get_path_length,
2287 struct GNUNET_PeerIdentity *get_path,
2288 struct GNUNET_TIME_Absolute expiration,
2289 const void *data, size_t data_size)
2291 struct PeerGetResultMessage *get_result;
2292 struct GNUNET_PeerIdentity *get_result_path;
2293 struct GNUNET_PeerIdentity *pp;
2294 struct P2PPendingMessage *pending;
2295 struct FriendInfo *target_friend;
2296 int current_path_index;
2299 msize = get_path_length * sizeof (struct GNUNET_PeerIdentity) + data_size +
2300 sizeof (struct PeerPutMessage);
2302 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
2308 current_path_index = -1;
2309 if(get_path_length > 0)
2311 current_path_index = search_my_index(get_path, get_path_length);
2312 if (-1 == current_path_index)
2318 if (0 == current_path_index)
2320 GDS_CLIENTS_handle_reply (expiration, key, get_path_length,
2321 get_path, put_path_length,
2322 put_path, type, data_size, data);
2326 pending = GNUNET_malloc (sizeof (struct P2PPendingMessage) + msize);
2327 pending->importance = 0;
2328 get_result = (struct PeerGetResultMessage *)&pending[1];
2329 pending->msg = &get_result->header;
2330 get_result->header.size = htons (msize);
2331 get_result->header.type = htons (GNUNET_MESSAGE_TYPE_XDHT_P2P_GET_RESULT);
2332 get_result->key = *key;
2333 /* FIXME: check if you are passing the correct querying_peer as described in
2334 the get_result documentation. */
2335 memcpy (&(get_result->querying_peer), source_peer, sizeof (struct GNUNET_PeerIdentity));
2336 get_result->expiration_time = expiration;
2337 get_result_path = (struct GNUNET_PeerIdentity *)&get_result[1];
2338 if (get_path_length != 0)
2339 memcpy (get_result_path, get_path,
2340 sizeof (struct GNUNET_PeerIdentity) * get_path_length);
2341 memcpy (&get_result_path[get_path_length], data, data_size);
2343 /* FIXME: Is this correct? */
2344 if (put_path_length != 0)
2346 pp = (struct GNUNET_PeerIdentity *)&get_result_path[1];
2347 memcpy (pp, put_path,sizeof (struct GNUNET_PeerIdentity) * put_path_length);
2350 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2351 &get_result_path[current_path_index - 1]);
2352 GNUNET_CONTAINER_DLL_insert_tail (target_friend->head, target_friend->tail, pending);
2353 target_friend->pending_count++;
2354 process_friend_queue (target_friend);
2359 * Randomly choose one of your friends (which is not congested and have not crossed
2360 * trail threshold) from the friends_peer map
2361 * @return Friend Randomly chosen friend.
2362 * NULL in case friend peermap is empty, or all the friends are either
2363 * congested or have crossed trail threshold.
2365 static struct FriendInfo *
2366 select_random_friend ()
2368 unsigned int current_size;
2371 struct GNUNET_CONTAINER_MultiPeerMapIterator *iter;
2372 struct GNUNET_PeerIdentity key_ret;
2373 struct FriendInfo *friend;
2375 current_size = GNUNET_CONTAINER_multipeermap_size (friend_peermap);
2378 if (0 == current_size)
2381 index = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, current_size);
2382 iter = GNUNET_CONTAINER_multipeermap_iterator_create (friend_peermap);
2384 /* Iterate till you don't reach to index. */
2385 for (j = 0; j < index ; j++)
2386 GNUNET_assert (GNUNET_YES ==
2387 GNUNET_CONTAINER_multipeermap_iterator_next (iter, NULL, NULL));
2390 /* Reset the index in friend peermap to 0 as we reached to the end. */
2391 if (j == current_size)
2394 GNUNET_CONTAINER_multipeermap_iterator_destroy (iter);
2395 iter = GNUNET_CONTAINER_multipeermap_iterator_create (friend_peermap);
2399 /* Get the friend stored at the index, j*/
2400 GNUNET_assert (GNUNET_YES ==
2401 GNUNET_CONTAINER_multipeermap_iterator_next (iter,
2403 (const void **)&friend));
2405 /* This friend is not congested and has not crossed trail threshold. */
2406 if ((TRAILS_THROUGH_FRIEND_THRESHOLD > friend->trails_count) &&
2407 (0 == GNUNET_TIME_absolute_get_remaining (friend->congestion_timestamp).rel_value_us))
2413 } while (j != index);
2415 GNUNET_CONTAINER_multipeermap_iterator_destroy (iter);
2421 * Compute 64 bit value of finger_identity corresponding to a finger index using
2424 * n.finger[i] = n + pow (2,i),
2426 * n.finger[i] = n - 1, where
2429 * n.finger[i] = 64 bit finger value
2430 * @param finger_index Index corresponding to which we calculate 64 bit value.
2431 * @return 64 bit value.
2434 compute_finger_identity_value (unsigned int finger_index)
2438 memcpy (&my_id64, &my_identity, sizeof (uint64_t));
2439 my_id64 = GNUNET_ntohll (my_id64);
2441 /* Are we looking for immediate predecessor? */
2442 if (PREDECESSOR_FINGER_ID == finger_index)
2443 return (my_id64 -1);
2445 return (my_id64 + (unsigned long) pow (2, finger_index));
2450 * Choose a random friend. Start looking for the trail to reach to
2451 * finger identity corresponding to current_search_finger_index through
2452 * this random friend.
2454 * @param cls closure for this task
2455 * @param tc the context under which the task is running
2458 send_find_finger_trail_message (void *cls,
2459 const struct GNUNET_SCHEDULER_TaskContext *tc)
2461 struct FriendInfo *target_friend;
2462 struct GNUNET_TIME_Relative next_send_time;
2463 struct GNUNET_HashCode trail_id;
2464 unsigned int is_predecessor;
2465 uint64_t finger_id_value;
2467 /* Schedule another send_find_finger_trail_message task. */
2468 next_send_time.rel_value_us =
2469 DHT_FIND_FINGER_TRAIL_INTERVAL.rel_value_us +
2470 GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK,
2471 DHT_FIND_FINGER_TRAIL_INTERVAL.rel_value_us);
2472 find_finger_trail_task =
2473 GNUNET_SCHEDULER_add_delayed (next_send_time, &send_find_finger_trail_message,
2476 /* No space in my routing table. (Source and destination peers also store entries
2477 * in their routing table). */
2478 if (GNUNET_YES == GDS_ROUTING_threshold_reached())
2481 target_friend = select_random_friend ();
2482 if (NULL == target_friend)
2487 finger_id_value = compute_finger_identity_value (current_search_finger_index);
2488 if (PREDECESSOR_FINGER_ID == current_search_finger_index)
2493 /* Generate a unique trail id for trail we are trying to setup. */
2494 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_STRONG,
2495 &trail_id, sizeof (trail_id));
2496 GDS_NEIGHBOURS_send_trail_setup (my_identity, finger_id_value,
2497 target_friend->id, target_friend, 0, NULL,
2498 is_predecessor, trail_id, NULL);
2503 * In case there are already maximum number of possible trails to reach to a
2504 * finger, then check if the new trail's length is lesser than any of the
2506 * If yes then replace that old trail by new trail.
2508 * Note: Here we are taking length as a parameter to choose the best possible
2509 * trail, but there could be other parameters also like:
2510 * 1. duration of existence of a trail - older the better.
2511 * 2. if the new trail is completely disjoint than the
2512 * other trails, then may be choosing it is better.
2514 * @param existing_finger
2515 * @param new_finger_trail
2516 * @param new_finger_trail_length
2517 * @param new_finger_trail_id
2520 select_and_replace_trail (struct FingerInfo *existing_finger,
2521 const struct GNUNET_PeerIdentity *new_trail,
2522 unsigned int new_trail_length,
2523 struct GNUNET_HashCode new_trail_id)
2525 struct Trail *trail_list_iterator;
2526 unsigned int largest_trail_length;
2527 unsigned int largest_trail_index;
2528 struct Trail_Element *trail_element;
2531 largest_trail_length = new_trail_length;
2532 largest_trail_index = MAXIMUM_TRAILS_PER_FINGER + 1;
2534 GNUNET_assert (MAXIMUM_TRAILS_PER_FINGER == existing_finger->trails_count);
2536 for (i = 0; i < existing_finger->trails_count; i++)
2538 trail_list_iterator = &existing_finger->trail_list[i];
2539 if (trail_list_iterator->trail_length > largest_trail_length)
2541 largest_trail_length = trail_list_iterator->trail_length;
2542 largest_trail_index = i;
2546 /* New trail is not better than existing ones. Send trail teardown. */
2547 if (largest_trail_index == (MAXIMUM_TRAILS_PER_FINGER + 1))
2549 struct GNUNET_PeerIdentity next_hop;
2551 memcpy (&next_hop, &new_trail[0], sizeof(struct GNUNET_PeerIdentity));
2552 GDS_ROUTING_remove_trail (new_trail_id);
2553 GDS_NEIGHBOURS_send_trail_teardown (new_trail_id,
2554 GDS_ROUTING_SRC_TO_DEST,
2559 /* Send trail teardown message across the replaced trail. */
2560 struct Trail *replace_trail = &existing_finger->trail_list[largest_trail_index];
2561 GDS_ROUTING_remove_trail (replace_trail->trail_id);
2562 GDS_NEIGHBOURS_send_trail_teardown (replace_trail->trail_id,
2563 GDS_ROUTING_SRC_TO_DEST,
2564 &replace_trail->trail_head->peer);
2565 /* Free the trail. */
2566 while (NULL != (trail_element = replace_trail->trail_head))
2568 GNUNET_CONTAINER_DLL_remove (replace_trail->trail_head,
2569 replace_trail->trail_tail, trail_element);
2570 GNUNET_free_non_null (trail_element);
2573 /* Add new trial at that location. */
2574 replace_trail->is_present = GNUNET_YES;
2575 replace_trail->trail_length = new_trail_length;
2576 replace_trail->trail_id = new_trail_id;
2577 //FIXME: Do we need to add pointers for head and tail.
2579 while (i < new_trail_length)
2581 struct Trail_Element *element = GNUNET_new (struct Trail_Element);
2582 element->peer = new_trail[i];
2584 GNUNET_CONTAINER_DLL_insert_tail (replace_trail->trail_head,
2585 replace_trail->trail_tail,
2592 * Check if the new trail to reach to finger is unique or do we already have
2593 * such a trail present for finger.
2594 * @param existing_finger Finger identity
2595 * @param new_trail New trail to reach @a existing_finger
2596 * @param trail_length Total number of peers in new_trail.
2597 * @return #GNUNET_YES if the new trail is unique
2598 * #GNUNET_NO if same trail is already present.
2601 is_new_trail_unique (struct FingerInfo *existing_finger,
2602 const struct GNUNET_PeerIdentity *new_trail,
2603 unsigned int trail_length)
2605 struct Trail *trail_list_iterator;
2606 struct Trail_Element *trail_element;
2609 int trail_unique = GNUNET_NO;
2611 GNUNET_assert (existing_finger->trails_count > 0);
2613 /* Iterate over list of trails. */
2614 for (i = 0; i < existing_finger->trails_count; i++)
2616 trail_list_iterator = &existing_finger->trail_list[i];
2617 GNUNET_assert (GNUNET_YES == trail_list_iterator->is_present);
2619 /* New trail and existing trail length are not same. */
2620 if (trail_list_iterator->trail_length != trail_length)
2622 trail_unique = GNUNET_YES;
2626 trail_element = trail_list_iterator->trail_head;
2627 for (j = 0; j < trail_list_iterator->trail_length; j++)
2629 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&new_trail[j],
2630 &trail_element->peer))
2632 trail_unique = GNUNET_YES;
2635 trail_element = trail_element->next;
2638 trail_unique = GNUNET_NO;
2641 return trail_unique;
2646 * Add a new trail to existing finger. This function is called only when finger
2647 * is not my own identity or a friend.
2648 * @param existing_finger Finger
2649 * @param new_finger_trail New trail from me to finger, NOT including endpoints
2650 * @param new_finger_trail_length Total number of peers in @a new_finger_trail
2651 * @param new_finger_trail_id Unique identifier of the trail.
2654 add_new_trail (struct FingerInfo *existing_finger,
2655 const struct GNUNET_PeerIdentity *new_trail,
2656 unsigned int new_trail_length,
2657 struct GNUNET_HashCode new_trail_id)
2659 struct Trail *trail_list_iterator;
2660 struct FriendInfo *first_friend;
2663 if (GNUNET_NO == is_new_trail_unique (existing_finger, new_trail,
2669 trail_list_iterator = &existing_finger->trail_list[existing_finger->trails_count];
2670 GNUNET_assert (GNUNET_NO == trail_list_iterator->is_present);
2671 trail_list_iterator->trail_id = new_trail_id;
2672 trail_list_iterator->trail_length = new_trail_length;
2673 existing_finger->trails_count++;
2674 trail_list_iterator->is_present = GNUNET_YES;
2676 /* If finger is a friend then we never call this function. */
2677 GNUNET_assert (new_trail_length > 0);
2679 first_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2681 first_friend->trails_count++;
2683 for (i = 0; i < new_trail_length; i++)
2685 struct Trail_Element *element;
2686 element = GNUNET_new (struct Trail_Element);
2688 element->peer = new_trail[i];
2689 GNUNET_CONTAINER_DLL_insert_tail (trail_list_iterator->trail_head,
2690 trail_list_iterator->trail_tail,
2693 /* Do we need to add trail head and trail tail in the trail list itearator.*/
2699 * FIXME Check if this function is called for opposite direction if yes then
2700 * take it as parameter.
2701 * Get the next hop to send trail teardown message from routing table and
2702 * then delete the entry from routing table. Send trail teardown message for a
2703 * specific trail of a finger.
2704 * @param finger Finger whose trail is to be removed.
2705 * @param trail List of peers in trail from me to a finger, NOT including
2709 send_trail_teardown (struct FingerInfo *finger,
2710 struct Trail *trail)
2712 struct FriendInfo *friend;
2713 struct GNUNET_PeerIdentity *next_hop;
2715 GNUNET_assert (NULL !=
2716 (next_hop = GDS_ROUTING_get_next_hop (trail->trail_id,
2717 GDS_ROUTING_SRC_TO_DEST)));
2718 if (trail->trail_length > 0)
2719 GNUNET_assert (NULL != (friend =
2720 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2721 &trail->trail_head->peer)));
2723 GNUNET_assert (NULL != (friend =
2724 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2725 &finger->finger_identity)));
2727 GNUNET_assert (0 == GNUNET_CRYPTO_cmp_peer_identity (next_hop, &friend->id));
2728 GDS_ROUTING_remove_trail (trail->trail_id);
2729 friend->trails_count--;
2730 GDS_NEIGHBOURS_send_trail_teardown (trail->trail_id,
2731 GDS_ROUTING_SRC_TO_DEST,
2732 &trail->trail_head->peer);
2737 * Send trail teardown message across all the trails to reach to finger.
2738 * @param finger Finger whose all the trail should be freed.
2741 send_all_finger_trails_teardown (struct FingerInfo *finger)
2743 struct Trail *trail;
2746 for (i = 0; i < finger->trails_count; i++)
2748 trail = &finger->trail_list[i];
2749 GNUNET_assert (trail->is_present == GNUNET_YES);
2750 send_trail_teardown (finger, trail);
2756 * Free a specific trail
2757 * @param trail List of peers to be freed.
2760 free_trail (struct Trail *trail)
2762 struct Trail_Element *trail_element;
2764 while (NULL != (trail_element = trail->trail_head))
2766 GNUNET_CONTAINER_DLL_remove (trail->trail_head,
2769 GNUNET_free_non_null (trail_element);
2771 trail->trail_head = NULL;
2772 trail->trail_tail = NULL;
2777 * Free finger and its trail.
2778 * @param finger Finger to be freed.
2781 free_finger (struct FingerInfo *finger, unsigned int finger_table_index)
2783 struct Trail *trail;
2786 /* Free all the trails to reach to finger */
2787 for (i = 0; i < finger->trails_count; i++)
2789 trail = &finger->trail_list[i];
2790 //FIXME: Check if there are any missing entry in this list because of
2791 // how we insert. If not then no need of this check.
2792 if (GNUNET_NO == trail->is_present)
2795 if (trail->trail_length > 0)
2798 trail->is_present = GNUNET_NO;
2802 finger->is_present = GNUNET_NO;
2803 memset ((void *)&finger_table[finger_table_index], 0, sizeof (finger_table[finger_table_index]));
2808 * FIXME: ensure that you are not adding any trail to reach to a friend which
2809 * is a finger. Also decide on should you increment trails count of a friend
2810 * which is also a finger.
2811 * Add a new entry in finger table at finger_table_index.
2812 * In case finger identity is me or a friend, then don't add a trail. NOTE
2813 * trail length to reach to a finger can be 0 only if the finger is a friend
2815 * In case a finger is a friend, then increment the trails count of the friend.
2816 * @param finger_identity Peer Identity of new finger
2817 * @param finger_trail Trail to reach from me to finger (excluding both end points).
2818 * @param finger_trail_length Total number of peers in @a finger_trail.
2819 * @param trail_id Unique identifier of the trail.
2820 * @param finger_table_index Index in finger table.
2823 add_new_finger (struct GNUNET_PeerIdentity finger_identity,
2824 const struct GNUNET_PeerIdentity *finger_trail,
2825 unsigned int finger_trail_length,
2826 struct GNUNET_HashCode trail_id,
2827 unsigned int finger_table_index)
2829 struct FingerInfo *new_entry;
2830 struct FriendInfo *first_trail_hop;
2831 struct Trail *trail;
2834 new_entry = GNUNET_new (struct FingerInfo);
2835 new_entry->finger_identity = finger_identity;
2836 new_entry->finger_table_index = finger_table_index;
2837 new_entry->is_present = GNUNET_YES;
2839 /* If the new entry is my own identity. */
2840 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &finger_identity))
2842 new_entry->trails_count = 0;
2843 finger_table[finger_table_index] = *new_entry;
2847 /* If finger is a friend, then we don't actually have a trail.
2848 * Just a trail id */
2849 if (NULL != GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2852 new_entry->trail_list[0].trail_id = trail_id;
2853 new_entry->trails_count = 1;
2854 new_entry->trail_list[0].is_present = GNUNET_YES;
2855 new_entry->trail_list[0].trail_length = 0;
2856 new_entry->trail_list[0].trail_head = NULL;
2857 new_entry->trail_list[0].trail_tail = NULL;
2858 finger_table[finger_table_index] = *new_entry;
2859 GNUNET_assert (NULL !=
2861 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2862 &finger_identity)));
2863 first_trail_hop->trails_count++;
2867 /* finger trail length can be 0 only in case if finger is my identity or
2868 finger is friend. We should never reach here. */
2869 GNUNET_assert (finger_trail_length > 0);
2871 GNUNET_assert (NULL !=
2873 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2874 &finger_trail[0])));
2875 new_entry->trails_count = 1;
2876 first_trail_hop->trails_count++;
2878 /* Copy the finger trail into trail. */
2879 trail = GNUNET_new (struct Trail);
2880 while (i < finger_trail_length)
2882 struct Trail_Element *element = GNUNET_new (struct Trail_Element);
2884 element->next = NULL;
2885 element->prev = NULL;
2886 element->peer = finger_trail[i];
2887 GNUNET_CONTAINER_DLL_insert_tail (trail->trail_head,
2893 /* Add trail to trail list. */
2894 new_entry->trail_list[0].trail_head = trail->trail_head;
2895 new_entry->trail_list[0].trail_tail = trail->trail_tail;
2896 new_entry->trail_list[0].trail_length = finger_trail_length;
2897 new_entry->trail_list[0].trail_id = trail_id;
2898 new_entry->trail_list[0].is_present = GNUNET_YES;
2899 finger_table[finger_table_index] = *new_entry;
2900 GNUNET_free (new_entry);
2901 GNUNET_free (trail);
2907 * Scan the trail to check if there is any other friend in the trail other than
2908 * first hop. If yes then shortcut the trail, send trail compression message to
2909 * peers which are no longer part of trail and send back the updated trail
2910 * and trail_length to calling function.
2911 * @param finger_identity Finger whose trail we will scan.
2912 * @param finger_trail [in, out] Trail to reach from source to finger,
2913 * @param finger_trail_length Total number of peers in original finger_trail.
2914 * @param finger_trail_id Unique identifier of the finger trail.
2915 * @return updated trail length in case we shortcut the trail, else original
2918 static struct GNUNET_PeerIdentity *
2919 scan_and_compress_trail (struct GNUNET_PeerIdentity finger_identity,
2920 const struct GNUNET_PeerIdentity *trail,
2921 unsigned int trail_length,
2922 struct GNUNET_HashCode trail_id,
2923 int *new_trail_length)
2925 struct FriendInfo *target_friend;
2926 struct GNUNET_PeerIdentity *new_trail;
2929 /* If I am my own finger identity, then we set trail_length = 0.
2930 Note: Here we don't send trail compression message, as no peer in its
2931 trail added an entry in its routing table.*/
2932 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &finger_identity))
2934 *new_trail_length = 0;
2938 /* If finger identity is a friend. */
2939 if (NULL != GNUNET_CONTAINER_multipeermap_get (friend_peermap, &finger_identity))
2941 *new_trail_length = 0;
2943 /* If there is trail to reach this finger/friend */
2944 if (trail_length > 0)
2946 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2948 /* FIXME: In case its finger == friend, then may be we send a trail
2949 teardown message as it does not make any sense to have any routing e
2950 entry in your own routing table.*/
2951 GDS_NEIGHBOURS_send_trail_compression (my_identity,
2952 trail_id, finger_identity,
2958 /* For other cases, when its neither a friend nor my own identity.*/
2959 for (i = trail_length - 1; i > 0; i--)
2961 /* If the element at this index in trail is a friend. */
2962 if (NULL != GNUNET_CONTAINER_multipeermap_get (friend_peermap, &trail[i]))
2964 struct FriendInfo *target_friend;
2967 GNUNET_assert (NULL !=
2969 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
2971 GDS_NEIGHBOURS_send_trail_compression (my_identity,
2976 /* Copy the trail from index i to index (trail_length -1) into a new trail
2977 * and update new trail length */
2978 new_trail = GNUNET_malloc (sizeof (struct GNUNET_PeerIdentity) * i);
2979 while (i < trail_length)
2981 memcpy (&new_trail[j], &trail[i], sizeof(struct GNUNET_PeerIdentity));
2985 *new_trail_length = j+1;
2990 /* If we did not compress the trail, return the original trail back.*/
2991 new_trail = GNUNET_malloc (sizeof (struct GNUNET_PeerIdentity) * trail_length);
2992 *new_trail_length = trail_length;
2993 memcpy (new_trail, trail, trail_length * sizeof (struct GNUNET_PeerIdentity));
2999 * Send verify successor message to your current successor over the shortest
3001 * @param successor Current successor.
3004 send_verify_successor_message (struct FingerInfo *successor)
3007 * FIXME: should we send a verify successor message across all the trails
3008 * in case we send through all friends. It complicates the logic, don't
3009 * do it at the moment. Write it as optimization and do it later.
3010 * 1. Here we can have 3 types of fingers
3011 * --> my own identity
3012 * Assumption that the calling function will not send request for
3013 * such successor. Move the logic here.
3014 * --> friend is a finger
3015 * Need to verify if we keep the trails count for a friend. In case of
3016 * friend there is no trail to reach to that friend, so
3017 * 1. no entry in routing table
3019 * 3. no trails count
3020 * 4. but do we increment the count of trails through the friend?
3021 * Trails count is used only to keep a limit on number of trails
3022 * that a friend should be part of. No need to increment the trails
3023 * count for a friend which is a finegr also. so, if finger = friend
3024 * then don't increment the trails count. But if the same friend
3025 * is the first friend to reach to some other finger then increment
3026 * the trails count. Not sure if this design is correct need to verify
3030 struct FriendInfo *target_friend;
3031 struct GNUNET_HashCode trail_id;
3034 for (i = 0; i < successor->trails_count; i++)
3036 struct Trail *trail;
3037 struct Trail_Element *element;
3038 unsigned int trail_length;
3041 trail = &successor->trail_list[i];
3043 /* No trail stored at this index. */
3044 if (GNUNET_YES == trail->is_present)
3047 trail_id = trail->trail_id;
3048 trail_length = trail->trail_length;
3050 /* Copy the trail into peer list. */
3051 element = trail->trail_head;
3052 struct GNUNET_PeerIdentity peer_list[trail_length];
3053 while (j < trail_length)
3055 peer_list[j] = element->peer;
3056 element = element->next;
3060 if (trail_length > 0)
3061 GNUNET_assert (NULL != (target_friend =
3062 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
3065 GNUNET_assert (NULL != (target_friend =
3066 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
3067 &successor->finger_identity)));
3068 GDS_NEIGHBOURS_send_verify_successor_message (my_identity,
3069 successor->finger_identity,
3070 trail_id, peer_list, trail_length,
3078 * Update the current search finger index.
3081 update_current_search_finger_index (struct GNUNET_PeerIdentity finger_identity,
3082 unsigned int finger_table_index)
3084 struct FingerInfo *successor;
3086 if (finger_table_index != current_search_finger_index)
3089 successor = &finger_table[0];
3090 if (GNUNET_NO == successor->is_present)
3093 /* We were looking for immediate successor. */
3094 if (0 == current_search_finger_index)
3096 /* Start looking for immediate predecessor. */
3097 current_search_finger_index = PREDECESSOR_FINGER_ID;
3099 /* If I am not my own successor, then send a verify successor message. */
3100 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &finger_identity))
3102 send_verify_successor_message (successor);
3107 current_search_finger_index = current_search_finger_index - 1;
3113 * Calculate finger_table_index from initial 64 bit finger identity value that
3114 * we send in trail setup message.
3115 * @param ultimate_destination_finger_value Value that we calculated from our
3116 * identity and finger_table_index.
3117 * @param is_predecessor Is the entry for predecessor or not?
3118 * @return finger_table_index Value between 0 <= finger_table_index <= 64
3119 * finger_table_index > PREDECESSOR_FINGER_ID ,
3120 * if no valid finger_table_index is found.
3123 get_finger_table_index (uint64_t ultimate_destination_finger_value,
3124 unsigned int is_predecessor)
3128 unsigned int finger_table_index;
3130 memcpy (&my_id64, &my_identity, sizeof (uint64_t));
3131 my_id64 = GNUNET_ntohll (my_id64);
3133 /* Is this a predecessor finger? */
3134 if (1 == is_predecessor)
3136 diff = my_id64 - ultimate_destination_finger_value;
3138 finger_table_index = PREDECESSOR_FINGER_ID;
3140 finger_table_index = PREDECESSOR_FINGER_ID + 1; //error value
3145 diff = ultimate_destination_finger_value - my_id64;
3146 finger_table_index = (log10 (diff))/(log10 (2));
3149 return finger_table_index;
3154 * Remove finger and its associated data structures from finger table.
3155 * @param finger Finger to be removed.
3158 remove_existing_finger (struct FingerInfo *existing_finger, unsigned int finger_table_index)
3160 struct FingerInfo *finger;
3162 finger = &finger_table[finger_table_index];
3163 GNUNET_assert (GNUNET_YES == finger->is_present);
3165 /* If I am my own finger, then we have no trails. */
3166 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&finger->finger_identity,
3169 finger->is_present = GNUNET_NO;
3170 memset ((void *)&finger_table[finger_table_index], 0, sizeof (finger_table[finger_table_index]));
3174 /* For all other fingers, send trail teardown across all the trails to reach
3175 finger, and free the finger. */
3176 send_all_finger_trails_teardown (finger);
3177 free_finger (finger, finger_table_index);
3183 * This is a test function to print all the entries of friend table.
3186 test_friend_peermap_print ()
3188 struct FriendInfo *friend;
3189 struct GNUNET_CONTAINER_MultiPeerMapIterator *friend_iter;
3190 struct GNUNET_PeerIdentity print_peer;
3191 struct GNUNET_PeerIdentity key_ret;
3194 friend_iter = GNUNET_CONTAINER_multipeermap_iterator_create (friend_peermap);
3196 for (i = 0; i < GNUNET_CONTAINER_multipeermap_size (friend_peermap); i++)
3198 if(GNUNET_YES == GNUNET_CONTAINER_multipeermap_iterator_next (friend_iter,
3200 (const void **)&friend))
3202 memcpy (&print_peer, &key_ret, sizeof (struct GNUNET_PeerIdentity));
3203 FPRINTF (stderr,_("\nSUPU %s, %s, %d, friend = %s, friend->trails_count = %d"),
3204 __FILE__, __func__,__LINE__, GNUNET_i2s(&print_peer), friend->trails_count);
3211 * This is a test function, to print all the entries of finger table.
3214 test_finger_table_print()
3216 struct FingerInfo *finger;
3217 struct GNUNET_PeerIdentity print_peer;
3218 struct Trail *trail;
3223 FPRINTF (stderr,_("\nSUPU************ FINGER_TABLE"));
3224 for (i = 0; i < MAX_FINGERS; i++)
3226 finger = &finger_table[i];
3228 if (GNUNET_NO == finger->is_present)
3231 print_peer = finger->finger_identity;
3232 FPRINTF (stderr,_("\nSUPU %s, %s, %d, finger_table[%d] = %s, trails_count = %d"),
3233 __FILE__, __func__,__LINE__,i,GNUNET_i2s (&print_peer), finger->trails_count);
3236 for (j = 0; j < finger->trails_count; j++)
3238 trail = &finger->trail_list[j];
3239 FPRINTF (stderr,_("\nSUPU %s, %s, %d, trail_id[%d]=%s"),__FILE__, __func__,__LINE__,j, GNUNET_h2s(&trail->trail_id));
3240 struct Trail_Element *element;
3241 element = trail->trail_head;
3242 for (k = 0; k < trail->trail_length; k++)
3244 print_peer = element->peer;
3245 FPRINTF (stderr,_("\nSUPU %s, %s, %d,trail[%d] = %s "),__FILE__, __func__,__LINE__,k, GNUNET_i2s(&print_peer));
3246 element = element->next;
3254 * Check if there is already an entry in finger_table at finger_table_index.
3255 * We get the finger_table_index from 64bit finger value we got from the network.
3256 * -- If yes, then select the closest finger.
3257 * -- If new and existing finger are same, then check if you can store more
3259 * -- If yes then add trail, else keep the best trails to reach to the
3261 * -- If the new finger is closest, remove the existing entry, send trail
3262 * teardown message across all the trails to reach the existing entry.
3263 * Add the new finger.
3264 * -- If new and existing finger are different, and existing finger is closest
3266 * -- Update current_search_finger_index.
3267 * @param finger_identity Peer Identity of new finger
3268 * @param finger_trail Trail to reach the new finger
3269 * @param finger_trail_length Total number of peers in @a new_finger_trail.
3270 * @param is_predecessor Is this entry for predecessor in finger_table?
3271 * @param finger_value 64 bit value of finger identity that we got from network.
3272 * @param finger_trail_id Unique identifier of @finger_trail.
3275 finger_table_add (struct GNUNET_PeerIdentity finger_identity,
3276 const struct GNUNET_PeerIdentity *finger_trail,
3277 unsigned int finger_trail_length,
3278 unsigned int is_predecessor,
3279 uint64_t finger_value,
3280 struct GNUNET_HashCode finger_trail_id)
3282 struct FingerInfo *existing_finger;
3283 struct GNUNET_PeerIdentity *closest_peer;
3284 struct GNUNET_PeerIdentity *updated_trail;
3285 struct FingerInfo *successor;
3286 int updated_finger_trail_length;
3287 unsigned int finger_table_index;
3290 test_friend_peermap_print();
3291 test_finger_table_print();
3294 /* Get the finger_table_index corresponding to finger_value we got from network.*/
3295 finger_table_index = get_finger_table_index (finger_value, is_predecessor);
3297 /* Invalid finger_table_index. */
3298 if ((finger_table_index > PREDECESSOR_FINGER_ID))
3300 GNUNET_break_op (0);
3304 /* If the new entry for any finger table index other than successor or predecessor
3305 * is same as successor then don't add it in finger table,
3306 * reset the current search finger index and exit. */
3307 if ((0 != finger_table_index) &&
3308 (PREDECESSOR_FINGER_ID != finger_table_index) &&
3309 (finger_table_index == current_search_finger_index)) //FIXME; why do I check this cond?
3311 successor = &finger_table[0];
3312 GNUNET_assert (GNUNET_YES == successor->is_present);
3313 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&finger_identity,
3314 &successor->finger_identity))
3316 current_search_finger_index = 0;
3321 existing_finger = &finger_table[finger_table_index];
3323 /* Shorten the trail if possible. */
3324 updated_finger_trail_length = finger_trail_length;
3326 scan_and_compress_trail (finger_identity, finger_trail,
3327 finger_trail_length, finger_trail_id,
3328 &updated_finger_trail_length);
3330 /* No entry present in finger_table for given finger map index. */
3331 if (GNUNET_NO == existing_finger->is_present)
3333 add_new_finger (finger_identity, updated_trail,
3334 updated_finger_trail_length,
3335 finger_trail_id, finger_table_index);
3336 update_current_search_finger_index (finger_identity, finger_table_index);
3337 GNUNET_free_non_null (updated_trail);
3342 /* If existing entry and finger identity are not same. */
3343 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&(existing_finger->finger_identity),
3346 closest_peer = select_closest_peer (&existing_finger->finger_identity,
3351 /* If the new finger is the closest peer. */
3352 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&finger_identity, closest_peer))
3354 remove_existing_finger (existing_finger, finger_table_index);
3355 add_new_finger (finger_identity, updated_trail, updated_finger_trail_length,
3356 finger_trail_id, finger_table_index);
3361 /* If both new and existing entry are same as my_identity, then do nothing. */
3362 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&(existing_finger->finger_identity),
3365 GNUNET_free_non_null (updated_trail);
3368 /* If the existing finger is not a friend. */
3370 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
3371 &existing_finger->finger_identity))
3373 /* If there is space to store more trails. */
3374 if (existing_finger->trails_count < MAXIMUM_TRAILS_PER_FINGER)
3375 add_new_trail (existing_finger, updated_trail,
3376 finger_trail_length, finger_trail_id);
3378 select_and_replace_trail (existing_finger, updated_trail,
3379 finger_trail_length, finger_trail_id);
3382 update_current_search_finger_index (finger_identity, finger_table_index);
3383 GNUNET_free_non_null (updated_trail);
3389 * Core handler for P2P put messages.
3390 * @param cls closure
3391 * @param peer sender of the request
3392 * @param message message
3393 * @return #GNUNET_OK to keep the connection open,
3394 * #GNUNET_SYSERR to close it (signal serious error)
3397 handle_dht_p2p_put (void *cls, const struct GNUNET_PeerIdentity *peer,
3398 const struct GNUNET_MessageHeader *message)
3400 struct PeerPutMessage *put;
3401 struct GNUNET_PeerIdentity *put_path;
3402 struct GNUNET_HashCode test_key;
3403 enum GNUNET_DHT_RouteOption options;
3404 struct GNUNET_PeerIdentity best_known_dest;
3405 struct GNUNET_HashCode intermediate_trail_id;
3406 struct GNUNET_PeerIdentity *next_hop;
3410 size_t payload_size;
3413 msize = ntohs (message->size);
3414 if (msize < sizeof (struct PeerPutMessage))
3416 GNUNET_break_op (0);
3420 put = (struct PeerPutMessage *) message;
3421 putlen = ntohl (put->put_path_length);
3424 sizeof (struct PeerPutMessage) +
3425 putlen * sizeof (struct GNUNET_PeerIdentity)) ||
3427 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)))
3429 GNUNET_break_op (0);
3433 best_known_dest = put->best_known_destination;
3434 put_path = (struct GNUNET_PeerIdentity *) &put[1];
3435 payload = &put_path[putlen];
3436 options = ntohl (put->options);
3437 intermediate_trail_id = put->intermediate_trail_id;
3439 payload_size = msize - (sizeof (struct PeerPutMessage) +
3440 putlen * sizeof (struct GNUNET_PeerIdentity));
3442 switch (GNUNET_BLOCK_get_key (GDS_block_context, ntohl (put->block_type),
3443 payload, payload_size, &test_key))
3446 if (0 != memcmp (&test_key, &put->key, sizeof (struct GNUNET_HashCode)))
3448 char *put_s = GNUNET_strdup (GNUNET_h2s_full (&put->key));
3449 GNUNET_break_op (0);
3450 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3451 "PUT with key `%s' for block with key %s\n",
3452 put_s, GNUNET_h2s_full (&test_key));
3453 GNUNET_free (put_s);
3458 GNUNET_break_op (0);
3461 /* cannot verify, good luck */
3465 if (ntohl (put->block_type) == GNUNET_BLOCK_TYPE_REGEX) /* FIXME: do for all tpyes */
3467 switch (GNUNET_BLOCK_evaluate (GDS_block_context,
3468 ntohl (put->block_type),
3470 NULL, 0, /* bloom filer */
3471 NULL, 0, /* xquery */
3472 payload, payload_size))
3474 case GNUNET_BLOCK_EVALUATION_OK_MORE:
3475 case GNUNET_BLOCK_EVALUATION_OK_LAST:
3478 case GNUNET_BLOCK_EVALUATION_OK_DUPLICATE:
3479 case GNUNET_BLOCK_EVALUATION_RESULT_INVALID:
3480 case GNUNET_BLOCK_EVALUATION_RESULT_IRRELEVANT:
3481 case GNUNET_BLOCK_EVALUATION_REQUEST_VALID:
3482 case GNUNET_BLOCK_EVALUATION_REQUEST_INVALID:
3483 case GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED:
3485 GNUNET_break_op (0);
3490 /* extend 'put path' by sender */
3491 struct GNUNET_PeerIdentity pp[putlen + 1];
3492 if (0 != (options & GNUNET_DHT_RO_RECORD_ROUTE))
3494 memcpy (pp, put_path, putlen * sizeof (struct GNUNET_PeerIdentity));
3501 memcpy (&key_value, &(put->key), sizeof (uint64_t));
3502 if (0 != (GNUNET_CRYPTO_cmp_peer_identity (&best_known_dest, &my_identity)))
3504 next_hop = GDS_ROUTING_get_next_hop (intermediate_trail_id,
3505 GDS_ROUTING_SRC_TO_DEST);
3509 next_hop = find_successor (key_value, &best_known_dest,
3510 &intermediate_trail_id, GDS_FINGER_TYPE_NON_PREDECESSOR);
3513 if (NULL == next_hop)
3515 GNUNET_STATISTICS_update (GDS_stats,
3516 gettext_noop ("# Next hop to forward the packet not found "
3517 "trail setup request, packet dropped."),
3519 return GNUNET_SYSERR;
3522 GDS_CLIENTS_process_put (options,
3523 ntohl (put->block_type),
3524 ntohl (put->hop_count),
3525 ntohl (put->desired_replication_level),
3527 GNUNET_TIME_absolute_ntoh (put->expiration_time),
3532 if (0 == GNUNET_CRYPTO_cmp_peer_identity(&my_identity, &best_known_dest)) /* I am the final destination */
3534 GDS_DATACACHE_handle_put (GNUNET_TIME_absolute_ntoh (put->expiration_time),
3535 &(put->key),putlen, pp, ntohl (put->block_type),
3536 payload_size, payload);
3537 GNUNET_free_non_null (next_hop);
3542 GDS_NEIGHBOURS_send_put (&put->key,
3543 ntohl (put->block_type),ntohl (put->options),
3544 ntohl (put->desired_replication_level),
3545 &best_known_dest, &intermediate_trail_id, next_hop,
3546 ntohl (put->hop_count), putlen, pp,
3547 GNUNET_TIME_absolute_ntoh (put->expiration_time),
3548 payload, payload_size);
3552 return GNUNET_SYSERR;
3557 * Core handler for p2p get requests.
3559 * @param cls closure
3560 * @param peer sender of the request
3561 * @param message message
3562 * @return #GNUNET_OK to keep the connection open,
3563 * #GNUNET_SYSERR to close it (signal serious error)
3566 handle_dht_p2p_get (void *cls, const struct GNUNET_PeerIdentity *peer,
3567 const struct GNUNET_MessageHeader *message)
3569 const struct PeerGetMessage *get;
3570 const struct GNUNET_PeerIdentity *get_path;
3571 struct GNUNET_PeerIdentity best_known_dest;
3572 struct GNUNET_HashCode intermediate_trail_id;
3573 struct GNUNET_PeerIdentity *next_hop;
3574 uint32_t get_length;
3578 msize = ntohs (message->size);
3579 if (msize < sizeof (struct PeerGetMessage))
3581 GNUNET_break_op (0);
3585 get = (const struct PeerGetMessage *)message;
3586 get_length = ntohl (get->get_path_length);
3587 best_known_dest = get->best_known_destination;
3588 intermediate_trail_id = get->intermediate_trail_id;
3589 get_path = (const struct GNUNET_PeerIdentity *)&get[1];
3592 sizeof (struct PeerGetMessage) +
3593 get_length * sizeof (struct GNUNET_PeerIdentity)) ||
3595 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity)))
3597 GNUNET_break_op (0);
3601 /* Add sender to get path */
3602 struct GNUNET_PeerIdentity gp[get_length + 1];
3604 memcpy (gp, get_path, get_length * sizeof (struct GNUNET_PeerIdentity));
3605 gp[get_length + 1] = *peer;
3606 get_length = get_length + 1;
3608 memcpy (&key_value, &(get->key), sizeof (uint64_t));
3610 /* I am not the final destination. I am part of trail to reach final dest. */
3611 if (0 != (GNUNET_CRYPTO_cmp_peer_identity (&best_known_dest, &my_identity)))
3613 next_hop = GDS_ROUTING_get_next_hop (intermediate_trail_id,
3614 GDS_ROUTING_SRC_TO_DEST);
3618 /* Get the next hop to pass the message to. */
3619 next_hop = find_successor (key_value, &best_known_dest,
3620 &intermediate_trail_id, GDS_FINGER_TYPE_NON_PREDECESSOR);
3623 if (NULL == next_hop)
3625 GNUNET_STATISTICS_update (GDS_stats,
3626 gettext_noop ("# Next hop to forward the packet not found "
3627 "trail setup request, packet dropped."),
3629 return GNUNET_SYSERR;
3632 /* I am the final destination. */
3633 if (0 == GNUNET_CRYPTO_cmp_peer_identity(&my_identity, &best_known_dest))
3635 struct GNUNET_PeerIdentity final_get_path[get_length+1];
3636 struct GNUNET_PeerIdentity next_hop;
3638 memcpy (final_get_path, gp, get_length * sizeof (struct GNUNET_PeerIdentity));
3639 memcpy (&final_get_path[get_length+1], &my_identity, sizeof (struct GNUNET_PeerIdentity));
3640 get_length = get_length + 1;
3642 /* Get the next hop to pass the get result message. */
3643 memcpy (&next_hop, &final_get_path[get_length-2], sizeof (struct GNUNET_PeerIdentity));
3644 GDS_DATACACHE_handle_get (&(get->key),(get->block_type), NULL, 0, NULL, 0,
3645 get_length, final_get_path, &next_hop, &my_identity);
3650 GDS_NEIGHBOURS_send_get (&(get->key), get->block_type, get->options,
3651 get->desired_replication_level, &best_known_dest,
3652 &intermediate_trail_id, next_hop, 0,
3655 GNUNET_free_non_null (next_hop);
3656 return GNUNET_SYSERR;
3661 * Core handler for get result
3662 * @param cls closure
3663 * @param peer sender of the request
3664 * @param message message
3665 * @return #GNUNET_OK to keep the connection open,
3666 * #GNUNET_SYSERR to close it (signal serious error)
3669 handle_dht_p2p_get_result (void *cls, const struct GNUNET_PeerIdentity *peer,
3670 const struct GNUNET_MessageHeader *message)
3672 struct PeerGetResultMessage *get_result;
3673 struct GNUNET_PeerIdentity *get_path;
3674 struct GNUNET_PeerIdentity *put_path;
3676 size_t payload_size;
3678 unsigned int getlen;
3679 unsigned int putlen;
3680 int current_path_index;
3682 msize = ntohs (message->size);
3683 if (msize < sizeof (struct PeerGetResultMessage))
3685 GNUNET_break_op (0);
3689 get_result = (struct PeerGetResultMessage *)message;
3690 getlen = ntohl (get_result->get_path_length);
3691 putlen = ntohl (get_result->put_path_length);
3694 sizeof (struct PeerGetResultMessage) +
3695 getlen * sizeof (struct GNUNET_PeerIdentity) +
3696 putlen * sizeof (struct GNUNET_PeerIdentity)) ||
3698 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity) ||
3700 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_PeerIdentity))))
3702 GNUNET_break_op (0);
3706 get_path = (struct GNUNET_PeerIdentity *) &get_result[1];
3707 payload = &get_path[getlen];
3708 payload_size = msize - (sizeof (struct PeerGetResultMessage) +
3709 getlen * sizeof (struct GNUNET_PeerIdentity));
3712 put_path = &get_path[1];
3714 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &(get_path[0]))))
3716 GDS_CLIENTS_handle_reply (get_result->expiration_time, &(get_result->key),
3717 getlen, get_path, putlen,
3718 put_path, get_result->type, payload_size, payload);
3723 current_path_index = search_my_index (get_path, getlen);
3724 if (GNUNET_SYSERR == current_path_index )
3727 return GNUNET_SYSERR;
3729 GDS_NEIGHBOURS_send_get_result (&(get_result->key), get_result->type,
3730 &get_path[current_path_index - 1],
3731 &(get_result->querying_peer), putlen, put_path,
3732 getlen, get_path, get_result->expiration_time,
3733 payload, payload_size);
3736 return GNUNET_SYSERR;
3741 * Get the best known next destination (local_dest) among your fingers, friends
3742 * and my identity. In case I was part of trail to reach to some other destination
3743 * (current_dest), then compare current_dest and local_dest, and choose the
3745 * @param final_dest_finger_value Peer closest to this value will be
3746 * @a local_best_known_dest
3747 * @param local_best_known_dest[out] Updated to peer identity which is closest to
3748 * @a final_dest_finger_value.
3749 * @param new_intermediate_trail_id In case @a local_best_known_dest is a finger,
3750 * then the trail id to reach to the finger
3751 * @param is_predecessor Is source peer trying to setup trail to its predecessor
3753 * @param current_dest Peer which should get this message ultimately according
3754 * to the peer which sent me this message. It could be me
3755 * or some other peer. In case it is not me, then I am a part
3756 * of trail to reach to that peer.
3759 static struct GNUNET_PeerIdentity *
3760 get_local_best_known_next_hop (uint64_t final_dest_finger_value,
3761 struct GNUNET_PeerIdentity *local_best_known_dest,
3762 struct GNUNET_HashCode *new_intermediate_trail_id,
3763 struct GNUNET_HashCode intermediate_trail_id,
3764 unsigned int is_predecessor,
3765 struct GNUNET_PeerIdentity *current_dest)
3767 struct GNUNET_PeerIdentity *next_hop_to_local_best_known_dest;
3769 /* Choose a local best known hop among your fingers, friends and you. */
3770 next_hop_to_local_best_known_dest = find_successor (final_dest_finger_value,
3771 local_best_known_dest,
3772 new_intermediate_trail_id,
3775 /* Are we just a part of a trail towards a finger (current_destination)? */
3776 if (0 != (GNUNET_CRYPTO_cmp_peer_identity (&my_identity, current_dest)))
3778 struct GNUNET_PeerIdentity *closest_peer;
3780 /* Select best successor among one found locally and current_destination
3781 * that we got from network.*/
3782 closest_peer = select_closest_peer (local_best_known_dest,
3784 final_dest_finger_value,
3787 /* Is current dest (end point of the trail of which I am a part) closest_peer? */
3788 if (0 == GNUNET_CRYPTO_cmp_peer_identity (current_dest, closest_peer))
3790 struct GNUNET_PeerIdentity *next_hop;
3791 next_hop = GDS_ROUTING_get_next_hop (intermediate_trail_id,
3792 GDS_ROUTING_SRC_TO_DEST);
3793 /* FIXME: Here we found next_hop NULL from routing table, but we still
3794 * have a next_hop from find_successor should we not break and choose that
3796 if (NULL == next_hop)
3798 GNUNET_break_op (0);
3801 next_hop_to_local_best_known_dest = next_hop;
3802 local_best_known_dest = current_dest;
3803 *new_intermediate_trail_id = intermediate_trail_id;
3807 GNUNET_assert (NULL != next_hop_to_local_best_known_dest);
3808 return next_hop_to_local_best_known_dest;
3813 * Core handle for PeerTrailSetupMessage.
3814 * @param cls closure
3815 * @param message message
3816 * @param peer peer identity this notification is about
3817 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
3820 handle_dht_p2p_trail_setup (void *cls, const struct GNUNET_PeerIdentity *peer,
3821 const struct GNUNET_MessageHeader *message)
3823 const struct PeerTrailSetupMessage *trail_setup;
3824 const struct GNUNET_PeerIdentity *trail_peer_list;
3825 struct GNUNET_PeerIdentity *local_best_known_dest;
3826 struct GNUNET_PeerIdentity current_dest;
3827 struct GNUNET_PeerIdentity *next_hop_towards_local_best_known_dest;
3828 struct GNUNET_PeerIdentity next_peer;
3829 struct FriendInfo *target_friend;
3830 struct GNUNET_PeerIdentity source;
3831 uint64_t final_dest_finger_val;
3832 struct GNUNET_HashCode new_intermediate_trail_id;
3833 struct GNUNET_HashCode intermediate_trail_id;
3834 struct GNUNET_HashCode trail_id;
3835 unsigned int is_predecessor;
3836 uint32_t trail_length;
3839 msize = ntohs (message->size);
3840 if (msize < sizeof (struct PeerTrailSetupMessage))
3842 GNUNET_break_op (0);
3846 trail_setup = (const struct PeerTrailSetupMessage *) message;
3847 trail_length = (msize - sizeof (struct PeerTrailSetupMessage))/
3848 sizeof (struct GNUNET_PeerIdentity);
3849 if ((msize - sizeof (struct PeerTrailSetupMessage)) %
3850 sizeof (struct GNUNET_PeerIdentity) != 0)
3852 GNUNET_break_op (0);
3856 trail_peer_list = (const struct GNUNET_PeerIdentity *)&trail_setup[1];
3857 current_dest = trail_setup->best_known_destination;
3858 trail_id = trail_setup->trail_id;
3859 final_dest_finger_val =
3860 GNUNET_ntohll (trail_setup->final_destination_finger_value);
3861 source = trail_setup->source_peer;
3862 is_predecessor = ntohl (trail_setup->is_predecessor);
3863 intermediate_trail_id = trail_setup->intermediate_trail_id;
3865 /* Is my routing table full? */
3866 if (GNUNET_YES == GDS_ROUTING_threshold_reached())
3868 /* As my routing table is full, I can no longer handle any more trail
3870 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, peer);
3871 GDS_NEIGHBOURS_send_trail_rejection (source, final_dest_finger_val,
3872 my_identity, is_predecessor,
3873 trail_peer_list, trail_length,
3874 trail_id, target_friend,
3875 CONGESTION_TIMEOUT);
3879 local_best_known_dest = GNUNET_new (struct GNUNET_PeerIdentity);
3881 /* Get the next hop to forward the trail setup request. */
3882 next_hop_towards_local_best_known_dest =
3883 get_local_best_known_next_hop (final_dest_finger_val,
3884 local_best_known_dest,
3885 &new_intermediate_trail_id,
3886 intermediate_trail_id,
3890 /* Am I the final destination? */
3891 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (local_best_known_dest,
3894 /* If I was not the source of this message for which now I am destination */
3895 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&source, &my_identity))
3897 GDS_ROUTING_add (trail_id, *peer, my_identity);
3900 if (0 == trail_length)
3901 memcpy (&next_peer, &source, sizeof (struct GNUNET_PeerIdentity));
3903 memcpy (&next_peer, &trail_peer_list[trail_length-1], sizeof (struct GNUNET_PeerIdentity));
3905 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, &next_peer);
3906 GDS_NEIGHBOURS_send_trail_setup_result (source,
3908 target_friend, trail_length,
3910 final_dest_finger_val,
3911 is_predecessor, trail_id);
3915 /* Add yourself to list of peers. */
3916 struct GNUNET_PeerIdentity peer_list[trail_length + 1];
3918 memcpy (peer_list, trail_peer_list,
3919 trail_length * sizeof (struct GNUNET_PeerIdentity));
3920 peer_list[trail_length] = my_identity;
3922 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
3923 next_hop_towards_local_best_known_dest);
3924 GDS_NEIGHBOURS_send_trail_setup (source,
3925 final_dest_finger_val,
3926 *local_best_known_dest,
3927 target_friend, trail_length + 1, peer_list,
3928 is_predecessor, trail_id,
3929 &new_intermediate_trail_id);
3931 GNUNET_free (local_best_known_dest);
3932 GNUNET_free (next_hop_towards_local_best_known_dest);
3937 /* FIXME: here we are calculating my_index and comparing also in this function.
3938 And we are doing it again here in this function. Re factor the code. */
3940 * FIXME: Should we call this function everywhere in all the handle functions
3941 * where we have a trail to verify from or a trail id. something like
3942 * if prev hop is not same then drop the message.
3943 * Check if sender_peer and peer from which we should receive the message are
3944 * same or different.
3945 * @param trail_peer_list List of peers in trail
3946 * @param trail_length Total number of peers in @a trail_peer_list
3947 * @param sender_peer Peer from which we got the message.
3948 * @param finger_identity Finger to which trail is setup. It is not part of trail.
3949 * @return #GNUNET_YES if sender_peer and peer from which we should receive the
3950 * message are different.
3951 * #GNUNET_NO if sender_peer and peer from which we should receive the
3952 * message are different.
3955 is_sender_peer_correct (const struct GNUNET_PeerIdentity *trail_peer_list,
3956 unsigned int trail_length,
3957 const struct GNUNET_PeerIdentity *sender_peer,
3958 struct GNUNET_PeerIdentity finger_identity,
3959 struct GNUNET_PeerIdentity source_peer)
3963 /* I am the source peer. */
3964 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (&source_peer,
3967 /* Is the first element of the trail is sender_peer.*/
3968 if (trail_length > 0)
3970 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&trail_peer_list[0],
3976 /* Is finger the sender peer? */
3977 if (0 != GNUNET_CRYPTO_cmp_peer_identity (sender_peer,
3984 /* Get my current location in the trail. */
3985 my_index = search_my_index (trail_peer_list, trail_length);
3989 /* I am the last element in the trail. */
3990 if ((trail_length - 1) == my_index)
3992 /* Is finger the sender_peer? */
3993 if (0 != GNUNET_CRYPTO_cmp_peer_identity (sender_peer,
3999 /* Is peer after me in trail the sender peer? */
4000 if (0 != GNUNET_CRYPTO_cmp_peer_identity (sender_peer,
4001 &trail_peer_list[my_index + 1]))
4010 * FIXME: we should also add a case where we search if we are present in the trail
4012 * Core handle for p2p trail setup result messages.
4014 * @param message message
4015 * @param peer sender of this message.
4016 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
4019 handle_dht_p2p_trail_setup_result(void *cls, const struct GNUNET_PeerIdentity *peer,
4020 const struct GNUNET_MessageHeader *message)
4022 const struct PeerTrailSetupResultMessage *trail_result;
4023 const struct GNUNET_PeerIdentity *trail_peer_list;
4024 struct GNUNET_PeerIdentity next_hop;
4025 struct FriendInfo *target_friend;
4026 struct GNUNET_PeerIdentity querying_peer;
4027 struct GNUNET_PeerIdentity finger_identity;
4028 uint32_t trail_length;
4029 uint64_t ulitmate_destination_finger_value;
4030 uint32_t is_predecessor;
4031 struct GNUNET_HashCode trail_id;
4035 msize = ntohs (message->size);
4036 if (msize < sizeof (struct PeerTrailSetupResultMessage))
4038 GNUNET_break_op (0);
4042 trail_result = (const struct PeerTrailSetupResultMessage *) message;
4043 trail_length = (msize - sizeof (struct PeerTrailSetupResultMessage))/
4044 sizeof (struct GNUNET_PeerIdentity);
4045 if ((msize - sizeof (struct PeerTrailSetupResultMessage)) %
4046 sizeof (struct GNUNET_PeerIdentity) != 0)
4048 GNUNET_break_op (0);
4052 is_predecessor = htonl (trail_result->is_predecessor);
4053 querying_peer = trail_result->querying_peer;
4054 finger_identity = trail_result->finger_identity;
4055 trail_id = trail_result->trail_id;
4056 trail_peer_list = (const struct GNUNET_PeerIdentity *) &trail_result[1];
4057 ulitmate_destination_finger_value =
4058 GNUNET_ntohll (trail_result->ulitmate_destination_finger_value);
4060 /* FIXME: here we are calculating my_index and comparing also in this function.
4061 And we are doing it again here in this function. Re factor the code. */
4062 /* Ensure that sender peer is the peer from which we were expecting the message. */
4063 if (GNUNET_NO == is_sender_peer_correct (trail_peer_list,
4065 peer, finger_identity, querying_peer))
4067 GNUNET_break_op (0);
4068 return GNUNET_SYSERR;
4071 /* Am I the one who initiated the query? */
4072 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (&querying_peer,
4075 /* If I am not my own finger identity, then add routing table entry. */
4076 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &finger_identity))
4078 GDS_ROUTING_add (trail_id, my_identity, *peer);
4081 finger_table_add (finger_identity, trail_peer_list,
4082 trail_length, ulitmate_destination_finger_value,
4083 is_predecessor, trail_id);
4087 /* Get my location in the trail. */
4088 my_index = search_my_index(trail_peer_list, trail_length);
4092 return GNUNET_SYSERR;
4095 /* FIXME: CHECK IF YOU ARE PRESENT MORE THAN ONCE IN THE TRAIL, IF YES
4096 THEN REMOVE ALL THE ENTRIES AND CHOOSE THE PEER THERE.*/
4098 next_hop = trail_result->querying_peer;
4100 next_hop = trail_peer_list[my_index - 1];
4102 /* If the querying_peer is its own finger, then don't add an entry in routing
4103 * table as querying peer will discard the trail. */
4104 if (0 != (GNUNET_CRYPTO_cmp_peer_identity (&(trail_result->querying_peer),
4105 &(trail_result->finger_identity))))
4107 GDS_ROUTING_add (trail_id, next_hop, *peer);
4110 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, &next_hop);
4111 GDS_NEIGHBOURS_send_trail_setup_result (querying_peer, finger_identity,
4112 target_friend, trail_length, trail_peer_list,
4114 ulitmate_destination_finger_value,
4122 * @param trail Trail to be inverted
4123 * @param trail_length Total number of peers in the trail.
4124 * @return Updated trail
4126 static struct GNUNET_PeerIdentity *
4127 invert_trail (const struct GNUNET_PeerIdentity *trail,
4128 unsigned int trail_length)
4132 struct GNUNET_PeerIdentity *inverted_trail;
4134 inverted_trail = GNUNET_malloc (sizeof(struct GNUNET_PeerIdentity) *
4137 j = trail_length - 1;
4138 while (i < trail_length)
4140 inverted_trail[i] = trail[j];
4144 return inverted_trail;
4149 * Return the shortest trail to reach from me to my_predecessor.
4150 * @param my_predecessor my current predecessor.
4151 * @param current_trail Trail from source to me.
4152 * @param current_trail_length Total number of peers in @a current_trail
4153 * @param trail_length [out] Total number of peers in selected trail.
4154 * @return Updated trail from source peer to my_predecessor.
4156 static struct GNUNET_PeerIdentity *
4157 trail_source_to_my_predecessor (const struct GNUNET_PeerIdentity *current_trail,
4158 unsigned int current_trail_length,
4159 unsigned int *trail_length)
4161 struct GNUNET_PeerIdentity *trail_me_to_predecessor;
4162 struct Trail *trail;
4163 struct Trail_Element *trail_element;
4164 struct FingerInfo *my_predecessor;
4166 unsigned int shortest_trail_length = 0;
4167 unsigned int trail_index = 0;
4169 my_predecessor = &finger_table[PREDECESSOR_FINGER_ID];
4171 GNUNET_assert (GNUNET_YES == my_predecessor->is_present);
4173 //if my_predecessor is a friend then don't send back any trail. as
4174 // there is no trail.
4177 /* Choose the shortest path from me to my predecessor. */
4178 for (i = 0; i < my_predecessor->trails_count; i++)
4180 trail = &my_predecessor->trail_list[i];
4181 if (trail->trail_length > shortest_trail_length)
4183 shortest_trail_length = trail->trail_length;
4187 *trail_length = shortest_trail_length;
4188 trail_me_to_predecessor = GNUNET_malloc (sizeof (struct GNUNET_PeerIdentity)
4191 /* Copy the selected trail and send this trail to calling function. */
4193 trail = &my_predecessor->trail_list[trail_index];
4194 trail_element = trail->trail_head;
4195 while ( i < shortest_trail_length)
4197 trail_me_to_predecessor[i] = trail_element->peer;
4199 trail_element = trail_element->next;
4202 return trail_me_to_predecessor;
4207 * FIXME In case predecessor is a friend then do we add it in routing table.
4208 * if not then check the logic of trail teardown in case we compress the trail
4209 * such that friend is finger. then do we remove the entry from end points or
4210 * not. Ideally we should remove the entries from end point.
4211 * Add finger as your predecessor. To add, first generate a new trail id, invert
4212 * the trail to get the trail from me to finger, add an entry in your routing
4213 * table, send add trail message to peers which are part of trail from me to
4214 * finger and add finger in finger table.
4217 * @param trail_length
4220 update_predecessor (struct GNUNET_PeerIdentity finger,
4221 struct GNUNET_PeerIdentity *trail,
4222 unsigned int trail_length)
4224 struct GNUNET_HashCode trail_to_new_predecessor_id;
4225 struct GNUNET_PeerIdentity *trail_to_new_predecessor;
4226 struct FriendInfo *target_friend;
4228 /* Generate trail id for trail from me to new predecessor = finger. */
4229 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_STRONG,
4230 &trail_to_new_predecessor_id,
4231 sizeof (trail_to_new_predecessor_id));
4233 /* Finger is a friend. */
4234 if (trail_length == 0)
4236 trail_to_new_predecessor = NULL;
4237 GDS_ROUTING_add (trail_to_new_predecessor_id, finger, my_identity);
4239 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4244 /* Invert the trail to get the trail from me to finger, NOT including the
4246 trail_to_new_predecessor = invert_trail (trail, trail_length);
4248 /* Add an entry in your routing table. */
4249 GDS_ROUTING_add (trail_to_new_predecessor_id,
4250 trail_to_new_predecessor[trail_length - 1],
4254 GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4255 &trail_to_new_predecessor[trail_length - 1]);
4258 /* Add entry in routing table of all peers that are part of trail from me
4259 to finger, including finger. */
4260 GDS_NEIGHBOURS_send_add_trail (my_identity,
4262 trail_to_new_predecessor_id,
4263 trail_to_new_predecessor,
4267 add_new_finger (finger, trail_to_new_predecessor, trail_length,
4268 trail_to_new_predecessor_id, PREDECESSOR_FINGER_ID);
4269 GNUNET_free_non_null (trail_to_new_predecessor);
4273 /* 3. In case you are successor, then
4274 * 3.1 check if you have a predecessor
4275 * 3.2 if no predecessor, then add the source of this message as your
4276 * predecessor. To add, first you should generate a new trail id,
4277 * invert the trail, send add trail message across new trail, add
4278 * an entry in finger table. Now, destination also have routing
4279 * table entry so add in your routing table also.
4280 * 3.3 If its closer than existing one, then do everything in step 1 and
4281 * free existing finger.
4282 * 3.3 If its same as the old one, then do nothing.
4283 * 3.4 if its not same as old one, and between source and old one, old one
4284 * is the correct predecessor, then construct a trail from source
4285 * to your old successor. scan the trail to remove duplicate entries.
4286 * 4. send verify successor result, with trail id of trail from source to
4287 * me. And also send the new trail from source to reach to its probable
4290 * 1. this function is called from both verify and notify.
4291 * 2. so write in a way that it is used in both.
4294 * Check if you have a predecessor.
4295 * 1. if no predecessor, then add finger as your predecessor. To add, first
4296 * generate a new trail id, invert the trail to get the trail from me to finger,
4297 * add an entry in your routing table, send add trail message to peers which
4298 * are part of trail from me to finger and add finger in finger table.
4299 * 2. If there is a predecessor, then compare existing one and finger.
4300 * 2.1 If finger is correct predecessor, then remove current_predecessor. And
4301 * do everything in step 1 to add finger into finger table.
4302 * 2.2 If current_predecessor is correct predecessor, the construct a trail from
4303 * finger to current_predecessor.
4306 * @param trail_length
4310 compare_and_update_predecessor (struct GNUNET_PeerIdentity finger,
4311 struct GNUNET_PeerIdentity *trail,
4312 unsigned int trail_length)
4314 struct FingerInfo *current_predecessor;
4315 struct GNUNET_PeerIdentity *closest_peer;
4316 uint64_t predecessor_value;
4317 unsigned int is_predecessor = 1;
4319 current_predecessor = &finger_table[PREDECESSOR_FINGER_ID];
4321 GNUNET_assert (0 != GNUNET_CRYPTO_cmp_peer_identity (&finger, &my_identity));
4323 /* No predecessor. Add finger as your predecessor. */
4324 if (GNUNET_NO == current_predecessor->is_present)
4326 update_predecessor (finger, trail, trail_length);
4330 predecessor_value = compute_finger_identity_value (PREDECESSOR_FINGER_ID);
4331 closest_peer = select_closest_peer (&finger,
4332 ¤t_predecessor->finger_identity,
4333 predecessor_value, is_predecessor);
4335 /* Finger is the closest predecessor. Remove the existing one and add the new
4337 if (0 == GNUNET_CRYPTO_cmp_peer_identity (closest_peer, &finger))
4339 remove_existing_finger (current_predecessor, PREDECESSOR_FINGER_ID);
4340 update_predecessor (finger, trail, trail_length);
4349 * FIXME: if i have no predecessor and I get a new predecessor but the first
4350 * friend to reach to that hop is congested then?
4351 * 1. check if you are the successor or not.
4352 * 2. if not then get the next hop from routing table, and pass the message,
4353 * 3. In case you are successor, then
4354 * 3.1 check if you have a predecessor
4355 * 3.2 if no predecessor, then add the source of this message as your
4356 * predecessor. To add, first you should generate a new trail id,
4357 * invert the trail, send add trail message across new trail, add
4358 * an entry in finger table. Now, destination also have routing
4359 * table entry so add in your routing table also.
4360 * 3.3 If its closer than existing one, then do everything in step 1 and
4361 * free existing finger.
4362 * 3.3 If its same as the old one, then do nothing.
4363 * 3.4 if its not same as old one, and between source and old one, old one
4364 * is the correct predecessor, then choose the shortest path to reach
4365 * from you to your predecessor. Pass this trail to source of this message.
4366 * It is the responsibility of source peer to scan the trail to reach to
4367 * its new probable successor.
4368 * 4. send verify successor result, with trail id of trail from source to
4369 * me. And also send the trail from me to reach to my predecessor, if
4370 * my_predecessor != source.
4372 * Core handle for p2p verify successor messages.
4373 * @param cls closure
4374 * @param message message
4375 * @param peer peer identity this notification is about
4376 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
4379 handle_dht_p2p_verify_successor(void *cls,
4380 const struct GNUNET_PeerIdentity *peer,
4381 const struct GNUNET_MessageHeader *message)
4383 const struct PeerVerifySuccessorMessage *vsm;
4384 struct GNUNET_HashCode trail_id;
4385 struct GNUNET_PeerIdentity successor;
4386 struct GNUNET_PeerIdentity source_peer;
4387 struct GNUNET_PeerIdentity *trail;
4388 struct GNUNET_PeerIdentity *next_hop;
4389 struct GNUNET_PeerIdentity *trail_to_predecessor;
4390 struct FingerInfo *current_predecessor;
4391 struct FriendInfo *target_friend;
4392 unsigned int trail_to_predecessor_length;
4394 unsigned int trail_length;
4396 msize = ntohs (message->size);
4398 /* Here we pass trail to reach from source to successor, and in case successor
4399 * does not have any predecessor, then we will add source as my predecessor.
4400 * So we pass the trail along with trail id. */
4401 if (msize < sizeof (struct PeerVerifySuccessorMessage))
4403 GNUNET_break_op (0);
4407 vsm = (const struct PeerVerifySuccessorMessage *) message;
4408 trail_length = (msize - sizeof (struct PeerVerifySuccessorMessage))/
4409 sizeof (struct GNUNET_PeerIdentity);
4410 if ((msize - sizeof (struct PeerVerifySuccessorMessage)) %
4411 sizeof (struct GNUNET_PeerIdentity) != 0)
4413 GNUNET_break_op (0);
4417 trail_id = vsm->trail_id;
4418 source_peer = vsm->source_peer;
4419 successor = vsm->successor;
4420 trail = (struct GNUNET_PeerIdentity *)&vsm[1];
4422 //FIXME: we can have a check if peer is correct peer which should have
4423 // sent this message. use same function is_sender_peer_correct
4424 // but specify direction so that the function can be used in other functions
4427 /* I am not the successor of source_peer. Pass the message to next_hop on
4429 if(0 != (GNUNET_CRYPTO_cmp_peer_identity (&successor, &my_identity)))
4431 next_hop = GDS_ROUTING_get_next_hop (trail_id, GDS_ROUTING_SRC_TO_DEST);
4432 if (NULL == next_hop)
4435 return GNUNET_SYSERR;
4437 GNUNET_assert (NULL !=
4439 GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop)));
4441 GDS_NEIGHBOURS_send_verify_successor_message (source_peer, successor,
4442 trail_id, trail, trail_length,
4447 /* I am the destination of this message. */
4449 /* Check if the source_peer could be our predecessor and if yes then update
4451 compare_and_update_predecessor (source_peer, trail, trail_length);
4453 current_predecessor = &finger_table[PREDECESSOR_FINGER_ID];
4455 /* Is source of this message NOT my predecessor. */
4456 if (0 != (GNUNET_CRYPTO_cmp_peer_identity (¤t_predecessor->finger_identity,
4459 /* if current predecessor is not a friend, we have a trail to reach to it*/
4460 if (NULL == (GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4461 ¤t_predecessor->finger_identity)))
4463 trail_to_predecessor =
4464 trail_source_to_my_predecessor (trail,
4466 &trail_to_predecessor_length);
4471 trail_to_predecessor = NULL;
4472 trail_to_predecessor_length = 0;
4474 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, peer);
4475 GDS_NEIGHBOURS_send_verify_successor_result (source_peer, my_identity,
4476 current_predecessor->finger_identity,
4477 trail_id, trail_to_predecessor,
4478 trail_to_predecessor_length,
4479 GDS_ROUTING_DEST_TO_SRC,
4481 GNUNET_free_non_null (trail_to_predecessor);
4487 * Construct the trail from me to probable successor that goes through current
4488 * successor. Scan this trail to check if you can shortcut the trail somehow.
4489 * In case we can shortcut the trail, don't send trail compression as we don't
4490 * have any entry in routing table.
4491 * @param current_successor
4492 * @param probable_successor
4493 * @param trail_from_curr_to_probable_successor
4494 * @param trail_from_curr_to_probable_successor_length
4495 * @param trail_to_new_successor_length
4498 static struct GNUNET_PeerIdentity *
4499 get_trail_to_new_successor (struct FingerInfo *current_successor,
4500 struct GNUNET_PeerIdentity probable_successor,
4501 const struct GNUNET_PeerIdentity *trail,
4502 unsigned int trail_length,
4503 unsigned int *trail_to_new_successor_length)
4505 struct GNUNET_PeerIdentity *trail_to_new_successor;
4507 /* If the probable successor is a friend, then we don't need to have a trail
4509 if (NULL != GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4510 &probable_successor))
4512 trail_to_new_successor = NULL;
4513 *trail_to_new_successor_length = 0;
4514 return trail_to_new_successor;
4518 * FIXME: can we some how use the select_finger_trail here??
4519 * complete this logic.
4520 * 1. Choose the shortest trail to reach to current successor.
4521 * 2. append the trail with the current trail
4522 * 3. scan the trail for duplicate elements
4523 * 4. scan the trail for friend
4524 * 5. get the shortest trail.
4525 * 6. send back the trail.
4532 * Compare probable successor and current successor.
4533 * If the probable successor is the correct successor, then construct the trail
4534 * from me to probable successor that goes through current successor. Scan this
4535 * trail to check if you can shortcut the trail somehow. In case we can short
4536 * cut the trail, don't send trail compression as we don't have any entry in
4538 * Once you have scanned trail, then add an entry in finger table.
4539 * Add an entry in routing table (Only if new successor is NOT a friend).
4540 * @param probable_successor Peer which could be our successor
4541 * @param trail_from_curr_to_probable_successor Trail from current successor
4542 * to probable successor, NOT
4544 * @param trail_from_curr_to_probable_successor_length Total number of peers
4545 * in @a trail_from_curr_to_probable_successor
4548 compare_and_update_successor (struct GNUNET_PeerIdentity probable_successor,
4549 const struct GNUNET_PeerIdentity *trail_from_curr_to_probable_successor,
4550 unsigned int trail_from_curr_to_probable_successor_length)
4552 struct GNUNET_PeerIdentity *closest_peer;
4553 struct GNUNET_PeerIdentity *trail_to_new_successor;
4554 struct GNUNET_HashCode trail_id;
4555 unsigned int trail_to_new_successor_length;
4556 uint64_t successor_value;
4557 struct FingerInfo *current_successor;
4558 struct FriendInfo *target_friend;
4559 unsigned int is_predecessor = 0;
4561 current_successor = &finger_table[0];
4562 GNUNET_assert (GNUNET_YES == current_successor->is_present);
4564 /* Compute the 64 bit value of successor identity. We need this as we need to
4565 * find the closest peer w.r.t this value.*/
4566 successor_value = compute_finger_identity_value (0);
4567 closest_peer = select_closest_peer (¤t_successor->finger_identity,
4568 &probable_successor,
4569 successor_value, is_predecessor);
4571 /* If the current_successor is the closest one, then exit. */
4572 if (0 == GNUNET_CRYPTO_cmp_peer_identity (closest_peer,
4573 ¤t_successor->finger_identity))
4576 /* probable successor is the closest_peer. */
4578 /* Get the trail to reach to your new successor. */
4579 trail_to_new_successor = get_trail_to_new_successor (current_successor,
4581 trail_from_curr_to_probable_successor,
4582 trail_from_curr_to_probable_successor_length,
4583 &trail_to_new_successor_length);
4584 /* Remove the existing successor. */
4585 remove_existing_finger (current_successor, 0);
4587 /* Generate a new trail id to reach to your new successor. */
4588 GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_STRONG,
4589 &trail_id, sizeof (trail_id));
4590 add_new_finger (probable_successor, trail_to_new_successor,
4591 trail_to_new_successor_length, trail_id, 0);
4593 /* If probable successor is not a friend, then add an entry in your own
4595 if (trail_to_new_successor_length > 0)
4597 GDS_ROUTING_add (trail_id, my_identity, trail_to_new_successor[0]);
4598 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4599 &trail_to_new_successor[0]);
4603 GDS_ROUTING_add (trail_id, my_identity, probable_successor);
4604 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
4605 &probable_successor);
4608 GDS_NEIGHBOURS_send_notify_new_successor (my_identity, probable_successor,
4609 trail_from_curr_to_probable_successor,
4610 trail_from_curr_to_probable_successor_length,
4618 * 1. If you are not the querying peer then pass on the message,
4619 * 2. If you are querying peer, then
4620 * 2.1 is new successor same as old one
4621 * 2.1.1 if yes then do noting
4622 * 2.1.2 if no then you need to notify the new one about your existence,
4623 * 2.1.2,1 also you need to remove the older successor, remove entry
4624 * from finger table, send trail teardown message across all the trail
4625 * of older successor. Call notify new successor with new trail id
4626 * and new trail to reach it.
4627 * Core handle for p2p verify successor result messages.
4628 * @param cls closure
4629 * @param message message
4630 * @param peer peer identity this notification is about
4631 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
4634 handle_dht_p2p_verify_successor_result(void *cls,
4635 const struct GNUNET_PeerIdentity *peer,
4636 const struct GNUNET_MessageHeader *message)
4638 const struct PeerVerifySuccessorResultMessage *vsrm;
4639 enum GDS_ROUTING_trail_direction trail_direction;
4640 struct GNUNET_PeerIdentity querying_peer;
4641 struct GNUNET_HashCode trail_id;
4642 struct GNUNET_PeerIdentity *next_hop;
4643 struct FriendInfo *target_friend;
4644 struct GNUNET_PeerIdentity probable_successor;
4645 const struct GNUNET_PeerIdentity *trail;
4646 unsigned int trail_length;
4649 msize = ntohs (message->size);
4650 /* We send a trail to reach from old successor to new successor, if
4651 * old_successor != new_successor.*/
4652 if (msize < sizeof (struct PeerVerifySuccessorResultMessage))
4654 GNUNET_break_op (0);
4658 vsrm = (const struct PeerVerifySuccessorResultMessage *) message;
4659 trail_length = (msize - sizeof (struct PeerVerifySuccessorResultMessage))/
4660 sizeof (struct GNUNET_PeerIdentity);
4662 if ((msize - sizeof (struct PeerVerifySuccessorResultMessage)) %
4663 sizeof (struct GNUNET_PeerIdentity) != 0)
4665 GNUNET_break_op (0);
4669 trail = (const struct GNUNET_PeerIdentity *) &vsrm[1];
4670 querying_peer = vsrm->querying_peer;
4671 trail_direction = ntohl (vsrm->trail_direction);
4672 trail_id = vsrm->trail_id;
4673 probable_successor = vsrm->probable_successor;
4675 //FIXME: add a check to ensure that peer from which you got the message is
4677 /* I am the querying_peer. */
4678 if(0 == (GNUNET_CRYPTO_cmp_peer_identity (&querying_peer, &my_identity)))
4680 compare_and_update_successor (probable_successor, trail, trail_length);
4684 /*If you are not the querying peer then pass on the message */
4685 GNUNET_assert (NULL != (next_hop =
4686 GDS_ROUTING_get_next_hop (trail_id, trail_direction)));
4687 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop);
4688 GDS_NEIGHBOURS_send_verify_successor_result (querying_peer,
4689 vsrm->current_successor,
4690 probable_successor, trail_id,
4693 trail_direction, target_friend);
4699 * Add entry in your routing table if source of the message is not a friend.
4700 * Irrespective if destination peer accepts source peer as predecessor or not,
4701 * we need to add an entry. So, that in next round to verify successor, source
4702 * is able to reach to its successor.
4703 * Check if you are the new successor of this message
4704 * 1. If yes the call function compare_and_update_successor(). This function
4705 * checks if source is real predecessor or not and take action accordingly.
4706 * 2. If not then find the next hop to find the message from the trail that
4707 * you got from the message and pass on the message.
4708 * Core handle for p2p notify new successor messages.
4709 * @param cls closure
4710 * @param message message
4711 * @param peer peer identity this notification is about
4712 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
4715 handle_dht_p2p_notify_new_successor(void *cls,
4716 const struct GNUNET_PeerIdentity *peer,
4717 const struct GNUNET_MessageHeader *message)
4719 const struct PeerNotifyNewSuccessorMessage *nsm;
4720 struct GNUNET_PeerIdentity *trail;
4721 struct GNUNET_PeerIdentity source;
4722 struct GNUNET_PeerIdentity new_successor;
4723 struct GNUNET_HashCode trail_id;
4724 struct GNUNET_PeerIdentity next_hop;
4725 struct FriendInfo *target_friend;
4728 uint32_t trail_length;
4730 msize = ntohs (message->size);
4731 /* We have the trail to reach from source to new successor. */
4732 if (msize < sizeof (struct PeerNotifyNewSuccessorMessage))
4734 GNUNET_break_op (0);
4738 nsm = (const struct PeerNotifyNewSuccessorMessage *) message;
4739 trail_length = (msize - sizeof (struct PeerNotifyNewSuccessorMessage))/
4740 sizeof (struct GNUNET_PeerIdentity);
4741 if ((msize - sizeof (struct PeerTrailRejectionMessage)) %
4742 sizeof (struct GNUNET_PeerIdentity) != 0)
4744 GNUNET_break_op (0);
4748 trail = (struct GNUNET_PeerIdentity *) &nsm[1];
4749 source = nsm->source_peer;
4750 new_successor = nsm->new_successor;
4751 trail_id = nsm->trail_id;
4753 //FIXME: add a check to make sure peer is correct.
4755 /* I am the new_successor to source_peer. */
4756 if ( 0 == GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &new_successor))
4758 /* Add an entry in routing table only if new predecessor is not a friend. */
4759 if (NULL == GNUNET_CONTAINER_multipeermap_get(friend_peermap, &source))
4761 GDS_ROUTING_add (trail_id, *peer, my_identity);
4763 compare_and_update_predecessor (source, trail, trail_length);
4767 /* I am part of trail to reach to successor. */
4768 my_index = search_my_index (trail, trail_length);
4771 GNUNET_break_op (0);
4772 return GNUNET_SYSERR;
4774 if (trail_length == my_index)
4775 next_hop = new_successor;
4777 next_hop = trail[my_index + 1];
4779 /* Add an entry in routing table for trail from source to its new successor. */
4780 GNUNET_assert (GNUNET_OK == GDS_ROUTING_add (trail_id, *peer, next_hop));
4781 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, &next_hop);
4782 GDS_NEIGHBOURS_send_notify_new_successor (source, new_successor, trail,
4784 trail_id, target_friend);
4791 * 1. Set the congestion timeout for the friend which is congested and sent
4793 * 2. Check if you were the source of this message
4794 * 2.1 If yes then exit. find_finger_trail_task is scheduled periodically.
4795 * So, we will eventually send a new request to setup trail to finger.
4796 * 2. Check if you can handle more trails through you. (Routing table space)
4797 * 2.1 If not then you are congested. Set your congestion time and pass this
4798 * message to peer before you in the trail setup so far.
4799 * 2.2 If yes, the call find_successor(). It will give you the next hop to
4800 * pass this message.
4801 * 2.2.1 If you are the final destination, then send back the trail setup
4803 * 2.2.2 If you are not the final dest, then send trail setup message to
4805 * Core handler for P2P trail rejection message
4806 * @param cls closure
4807 * @param message message
4808 * @param peer peer identity this notification is about
4809 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
4812 handle_dht_p2p_trail_setup_rejection (void *cls,
4813 const struct GNUNET_PeerIdentity *peer,
4814 const struct GNUNET_MessageHeader *message)
4816 const struct PeerTrailRejectionMessage *trail_rejection;
4817 unsigned int trail_length;
4818 const struct GNUNET_PeerIdentity *trail_peer_list;
4819 struct FriendInfo *target_friend;
4820 struct GNUNET_TIME_Relative congestion_timeout;
4821 struct GNUNET_HashCode trail_id;
4822 struct GNUNET_PeerIdentity next_destination;
4823 struct GNUNET_HashCode new_intermediate_trail_id;
4824 struct GNUNET_PeerIdentity next_peer;
4825 struct GNUNET_PeerIdentity source;
4826 struct GNUNET_PeerIdentity *next_hop;
4827 uint64_t ultimate_destination_finger_value;
4828 unsigned int is_predecessor;
4831 msize = ntohs (message->size);
4832 /* We are passing the trail setup so far. */
4833 if (msize < sizeof (struct PeerTrailRejectionMessage))
4835 GNUNET_break_op (0);
4839 trail_rejection = (const struct PeerTrailRejectionMessage *) message;
4840 trail_length = (msize - sizeof (struct PeerTrailRejectionMessage))/
4841 sizeof (struct GNUNET_PeerIdentity);
4842 if ((msize - sizeof (struct PeerTrailRejectionMessage)) %
4843 sizeof (struct GNUNET_PeerIdentity) != 0)
4845 GNUNET_break_op (0);
4849 trail_peer_list = (const struct GNUNET_PeerIdentity *)&trail_rejection[1];
4850 is_predecessor = ntohl (trail_rejection->is_predecessor);
4851 congestion_timeout = trail_rejection->congestion_time;
4852 source = trail_rejection->source_peer;
4853 trail_id = trail_rejection->trail_id;
4854 ultimate_destination_finger_value =
4855 GNUNET_ntohll (trail_rejection->ultimate_destination_finger_value);
4857 /* First set the congestion time of the friend that sent you this message. */
4858 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, peer);
4859 target_friend->congestion_timestamp =
4860 GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get(),
4861 congestion_timeout);
4863 /* I am the source peer which wants to setup the trail. Do nothing.
4864 * send_find_finger_trail_task is scheduled periodically.*/
4865 if(0 == (GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &source)))
4868 /* If I am congested then pass this message to peer before me in trail. */
4869 if(GNUNET_YES == GDS_ROUTING_threshold_reached())
4871 struct GNUNET_PeerIdentity *new_trail;
4872 unsigned int new_trail_length;
4874 /* Remove yourself from the trail setup so far. */
4875 if (trail_length == 1)
4878 new_trail_length = 0;
4883 memcpy (&next_hop , &trail_peer_list[trail_length - 2],
4884 sizeof (struct GNUNET_PeerIdentity));
4886 /* Remove myself from the trail. */
4887 new_trail_length = trail_length -1;
4888 new_trail = GNUNET_malloc (new_trail_length * sizeof (struct GNUNET_PeerIdentity));
4889 memcpy (new_trail, trail_peer_list, new_trail_length * sizeof (struct GNUNET_PeerIdentity));
4892 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop);
4893 GDS_NEIGHBOURS_send_trail_rejection (source,
4894 ultimate_destination_finger_value,
4895 my_identity, is_predecessor,
4896 new_trail,new_trail_length,trail_id,
4897 target_friend, CONGESTION_TIMEOUT);
4898 GNUNET_free (new_trail);
4902 /* Look for next_hop to pass the trail setup message */
4903 next_hop = find_successor (ultimate_destination_finger_value,
4905 &new_intermediate_trail_id,
4908 /* Am I the final destination? */
4909 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (next_hop, &my_identity)))
4911 /* Add an entry in routing table only
4912 * 1. If I am not the original source which sent the request for trail setup
4913 * 2. If trail length > 0.
4914 * NOTE: In case trail length > 0 and source is my friend, then also I add
4915 * an entry in routing table,as we will send a trail compression message
4918 if ((0 != GNUNET_CRYPTO_cmp_peer_identity (&source, &my_identity)) ||
4920 GNUNET_assert (GNUNET_YES == GDS_ROUTING_add (trail_id, *peer, my_identity));
4922 if (0 == trail_length)
4925 next_peer = trail_peer_list[trail_length-1];
4927 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, &next_peer);
4928 GDS_NEIGHBOURS_send_trail_setup_result (source,
4930 target_friend, trail_length,
4933 ultimate_destination_finger_value,
4938 struct GNUNET_PeerIdentity peer_list[trail_length + 1];
4940 memcpy (peer_list, trail_peer_list, trail_length * sizeof (struct GNUNET_PeerIdentity));
4941 peer_list[trail_length] = my_identity;
4943 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop);
4944 GDS_NEIGHBOURS_send_trail_setup (source,
4945 ultimate_destination_finger_value,
4947 target_friend, trail_length + 1, peer_list,
4948 is_predecessor, trail_id,
4949 &new_intermediate_trail_id);
4951 GNUNET_free (next_hop);
4957 * If you are the new first friend, then update prev hop to source of this message
4958 * else get the next hop and pass this message forward to ultimately reach
4960 * Core handle for p2p trail tear compression messages.
4961 * @param cls closure
4962 * @param message message
4963 * @param peer peer identity this notification is about
4964 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
4967 handle_dht_p2p_trail_compression (void *cls, const struct GNUNET_PeerIdentity *peer,
4968 const struct GNUNET_MessageHeader *message)
4970 const struct PeerTrailCompressionMessage *trail_compression;
4971 struct GNUNET_PeerIdentity *next_hop;
4972 struct FriendInfo *target_friend;
4973 struct GNUNET_HashCode trail_id;
4976 msize = ntohs (message->size);
4977 /* Here we pass only the trail id. */
4978 if (msize != sizeof (struct PeerTrailCompressionMessage))
4980 GNUNET_break_op (0);
4984 trail_compression = (const struct PeerTrailCompressionMessage *) message;
4985 trail_id = trail_compression->trail_id;
4986 //FIXME: again check if peer is the correct peer. same logic as
4987 //trail teardown make a generic function.
4989 /* Am I the new first friend to reach to finger of this trail. */
4990 if (0 == (GNUNET_CRYPTO_cmp_peer_identity (&(trail_compression->new_first_friend),
4993 /* Update your prev hop to source of this message. */
4994 GDS_ROUTING_update_trail_prev_hop (trail_id,
4995 trail_compression->source_peer);
4999 /* Pass the message to next hop to finally reach to new_first_friend. */
5000 next_hop = GDS_ROUTING_get_next_hop (trail_id, GDS_ROUTING_SRC_TO_DEST);
5001 if (NULL == next_hop)
5007 GNUNET_assert (NULL != (target_friend =
5008 GNUNET_CONTAINER_multipeermap_get (friend_peermap, next_hop)));
5009 GDS_NEIGHBOURS_send_trail_compression (trail_compression->source_peer,
5011 trail_compression->new_first_friend,
5018 * Remove entry from your own routing table and pass the message to next
5019 * peer in the trail.
5020 * Core handler for trail teardown message.
5021 * @param cls closure
5022 * @param message message
5023 * @param peer sender of this messsage.
5024 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
5027 handle_dht_p2p_trail_teardown (void *cls, const struct GNUNET_PeerIdentity *peer,
5028 const struct GNUNET_MessageHeader *message)
5030 const struct PeerTrailTearDownMessage *trail_teardown;
5031 enum GDS_ROUTING_trail_direction trail_direction;
5032 struct GNUNET_HashCode trail_id;
5033 //struct GNUNET_PeerIdentity *prev_hop;
5034 struct GNUNET_PeerIdentity *next_hop;
5036 msize = ntohs (message->size);
5038 /* Here we pass only the trail id. */
5039 if (msize != sizeof (struct PeerTrailTearDownMessage))
5041 GNUNET_break_op (0);
5045 trail_teardown = (const struct PeerTrailTearDownMessage *) message;
5046 trail_direction = ntohl (trail_teardown->trail_direction);
5047 trail_id = trail_teardown->trail_id;
5049 /* Check if peer is the real peer from which we should get this message.*/
5050 /* Get the prev_hop for this trail by getting the next hop in opposite direction. */
5051 /* FIXME: is using negation of trail direction correct. */
5053 GNUNET_assert (NULL != (prev_hop =
5054 GDS_ROUTING_get_next_hop (trail_id, !trail_direction)));
5055 if (0 != GNUNET_CRYPTO_cmp_peer_identity (prev_hop, peer))
5058 return GNUNET_SYSERR;
5062 next_hop = GDS_ROUTING_get_next_hop (trail_id, trail_direction);
5063 if (NULL == next_hop)
5066 return GNUNET_SYSERR;
5069 GNUNET_assert (GNUNET_YES == GDS_ROUTING_remove_trail (trail_id));
5071 /* If next_hop is my_identity, it means I am the final destination. */
5072 if (0 == GNUNET_CRYPTO_cmp_peer_identity (next_hop, &my_identity))
5075 /* If not final destination, then send a trail teardown message to next hop.*/
5076 GDS_NEIGHBOURS_send_trail_teardown (trail_id, trail_direction, next_hop);
5077 //GNUNET_free_non_null (next_hop);
5083 * Add an entry in your routing table. If you are destination of this message
5084 * then next_hop in routing table should be your own identity. If you are NOT
5085 * destination, then get the next hop and forward message to it.
5086 * Core handle for p2p add trail message.
5087 * @param cls closure
5088 * @param message message
5089 * @param peer peer identity this notification is about
5090 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
5093 handle_dht_p2p_add_trail (void *cls, const struct GNUNET_PeerIdentity *peer,
5094 const struct GNUNET_MessageHeader *message)
5096 const struct PeerAddTrailMessage *add_trail;
5097 const struct GNUNET_PeerIdentity *trail;
5098 struct GNUNET_HashCode trail_id;
5099 struct GNUNET_PeerIdentity destination_peer;
5100 struct GNUNET_PeerIdentity source_peer;
5101 struct GNUNET_PeerIdentity next_hop;
5102 unsigned int trail_length;
5103 unsigned int my_index;
5106 msize = ntohs (message->size);
5107 /* In this message we pass the whole trail from source to destination as we
5108 * are adding that trail.*/
5109 if (msize < sizeof (struct PeerAddTrailMessage))
5111 GNUNET_break_op (0);
5115 add_trail = (const struct PeerAddTrailMessage *) message;
5116 trail_length = (msize - sizeof (struct PeerAddTrailMessage))/
5117 sizeof (struct GNUNET_PeerIdentity);
5118 if ((msize - sizeof (struct PeerAddTrailMessage)) %
5119 sizeof (struct GNUNET_PeerIdentity) != 0)
5121 GNUNET_break_op (0);
5125 trail = (const struct GNUNET_PeerIdentity *)&add_trail[1];
5126 destination_peer = add_trail->destination_peer;
5127 source_peer = add_trail->source_peer;
5128 trail_id = add_trail->trail_id;
5130 //FIXME: add a check that sender peer is not malicious. Make it a generic
5131 // function so that it can be used in all other functions where we need the
5132 // same functionality.
5134 /* I am not the destination of the trail. */
5135 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&my_identity, &destination_peer))
5137 struct FriendInfo *target_friend;
5139 /* Get my location in the trail. */
5140 my_index = search_my_index (trail, trail_length);
5141 if (GNUNET_SYSERR == my_index)
5143 GNUNET_break_op (0);
5144 return GNUNET_SYSERR;
5148 next_hop = source_peer;
5150 next_hop = trail[trail_length - 1];
5152 /* Add in your routing table. */
5153 GNUNET_assert (GNUNET_OK == GDS_ROUTING_add (trail_id, next_hop, *peer));
5154 target_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap, &next_hop);
5155 GDS_NEIGHBOURS_send_add_trail (source_peer, destination_peer, trail_id,
5156 trail, trail_length, target_friend);
5160 /* I am the destination. Add an entry in routing table. */
5161 GNUNET_assert (GNUNET_OK == GDS_ROUTING_add (trail_id, *peer, my_identity));
5167 * Free the finger trail in which the first friend to reach to a finger is
5168 * disconnected_friend. Also remove entry from routing table for that particular
5170 * @param disconnected_friend PeerIdentity of friend which got disconnected
5171 * @param remove_finger Finger whose trail we need to check if it has
5172 * disconnected_friend as the first hop.
5173 * @return Total number of trails in which disconnected_friend was the first
5177 remove_matching_trails (const struct GNUNET_PeerIdentity *disconnected_friend,
5178 struct FingerInfo *remove_finger)
5180 unsigned int matching_trails_count;
5183 /* Number of trails with disconnected_friend as the first hop in the trail
5184 * to reach from me to remove_finger, NOT including endpoints. */
5185 matching_trails_count = 0;
5187 /* Iterate over all the trails of finger. */
5188 for (i = 0; i < remove_finger->trails_count; i++)
5190 struct Trail *trail;
5191 trail = &remove_finger->trail_list[i];
5193 if (GNUNET_NO == trail->is_present)
5196 /*FIXME: This is here to ensure that no finger which is a friend should ever call this
5197 function. remove afterwards.*/
5198 GNUNET_assert (trail->trail_length > 0);
5200 /* First friend to reach to finger is disconnected_peer. */
5201 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&trail->trail_head->peer,
5202 disconnected_friend))
5204 struct GNUNET_PeerIdentity *next_hop;
5205 struct FriendInfo *remove_friend;
5207 remove_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
5208 disconnected_friend);
5209 remove_friend->trails_count--;
5210 next_hop = GDS_ROUTING_get_next_hop (trail->trail_id, GDS_ROUTING_SRC_TO_DEST);
5211 GNUNET_assert (0 == (GNUNET_CRYPTO_cmp_peer_identity (disconnected_friend,
5213 matching_trails_count++;
5214 GDS_ROUTING_remove_trail (trail->trail_id);
5217 trail->is_present = GNUNET_NO;
5220 return matching_trails_count;
5225 * FIXME; make sure you handle friend correctle. remove entry from you
5226 * routing table if you are the source.
5227 * Iterate over finger_table entries.
5228 * 0. Ignore finger which is my_identity or if no valid entry present at
5229 * that finger index.
5230 * 1. If disconnected_friend is a finger, then remove the routing entry from
5231 your own table. Free the trail.
5232 * 2. Check if disconnected_friend is the first friend in the trail to reach to a finger.
5233 * 2.1 Remove all the trails and entry from routing table in which disconnected
5234 * friend is the first friend in the trail. If disconnected_friend is the
5235 * first friend in all the trails to reach finger, then remove the finger.
5236 * @param disconnected_friend Peer identity of friend which got disconnected.
5239 remove_matching_fingers (const struct GNUNET_PeerIdentity *disconnected_friend)
5241 struct FingerInfo *remove_finger;
5242 struct FriendInfo *remove_friend;
5243 int removed_trails_count;
5246 /* Iterate over finger table entries. */
5247 for (i = 0; i < MAX_FINGERS; i++)
5249 remove_finger = &finger_table[i];
5251 /* No finger stored at this trail index. */
5252 if (GNUNET_NO == remove_finger->is_present)
5255 /* I am my own finger, then ignore this finger. */
5256 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&remove_finger->finger_identity,
5260 /* Is disconnected_friend a finger? */
5261 if (0 == GNUNET_CRYPTO_cmp_peer_identity (disconnected_friend,
5262 &remove_finger->finger_identity))
5264 struct GNUNET_PeerIdentity *next_hop;
5265 struct GNUNET_HashCode trail_id;
5267 GNUNET_assert (GNUNET_YES == (remove_finger->trail_list[0].is_present));
5268 trail_id = remove_finger->trail_list[0].trail_id;
5270 GNUNET_assert (NULL !=
5272 GDS_ROUTING_get_next_hop (trail_id, GDS_ROUTING_SRC_TO_DEST)));
5273 /* As finger is a friend, you have no trail as such but you have entry in routing
5274 * table of source and dest, so next_hop will be same as finger identity. */
5276 (GNUNET_CRYPTO_cmp_peer_identity (next_hop,
5277 &remove_finger->finger_identity)));
5278 GDS_ROUTING_remove_trail (trail_id);
5279 remove_friend = GNUNET_CONTAINER_multipeermap_get (friend_peermap,
5280 disconnected_friend);
5281 remove_friend->trails_count--;
5282 remove_finger->is_present = GNUNET_NO;
5283 memset ((void *)&finger_table[i], 0, sizeof (finger_table[i]));
5287 /* If finger is a friend but not disconnected_friend, then continue. */
5288 if (NULL != GNUNET_CONTAINER_multipeermap_get (friend_peermap,
5289 &remove_finger->finger_identity))
5292 /* Iterate over the list of trails to reach remove_finger. Check if
5293 * disconnected_friend makis the first friend in any of the trail. */
5294 removed_trails_count = remove_matching_trails (disconnected_friend,
5297 /* All the finger trails had disconnected_friend as the first friend,
5298 * so free the finger. */
5299 if (removed_trails_count == remove_finger->trails_count)
5301 remove_finger->is_present = GNUNET_NO;
5302 memset ((void *)&finger_table[i], 0, sizeof (finger_table[i]));
5309 * Method called whenever a peer disconnects.
5311 * @param cls closure
5312 * @param peer peer identity this notification is about
5315 handle_core_disconnect (void *cls,
5316 const struct GNUNET_PeerIdentity *peer)
5318 struct FriendInfo *remove_friend;
5320 /* If disconnected to own identity, then return. */
5321 if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
5324 GNUNET_assert (NULL != (remove_friend =
5325 GNUNET_CONTAINER_multipeermap_get (friend_peermap, peer)));
5327 /* Remove fingers with peer as first friend or if peer is a finger. */
5328 remove_matching_fingers (peer);
5330 /* Remove any trail from routing table of which peer is a part of. This function
5331 * internally sends a trail teardown message in the direction of which
5332 * disconnected peer is not part of. */
5333 GDS_ROUTING_remove_trail_by_peer (peer);
5335 GNUNET_assert (0 == remove_friend->trails_count);
5336 /* Remove peer from friend_peermap. */
5337 GNUNET_assert (GNUNET_YES ==
5338 GNUNET_CONTAINER_multipeermap_remove (friend_peermap,
5342 if (0 != GNUNET_CONTAINER_multipeermap_size (friend_peermap))
5345 /* If there are no more friends in friend_peermap, then don't schedule
5346 * find_finger_trail_task. */
5347 if (GNUNET_SCHEDULER_NO_TASK != find_finger_trail_task)
5349 GNUNET_SCHEDULER_cancel (find_finger_trail_task);
5350 find_finger_trail_task = GNUNET_SCHEDULER_NO_TASK;
5359 * Method called whenever a peer connects.
5361 * @param cls closure
5362 * @param peer_identity peer identity this notification is about
5365 handle_core_connect (void *cls, const struct GNUNET_PeerIdentity *peer_identity)
5367 struct FriendInfo *friend;
5369 /* Check for connect to self message */
5370 if (0 == memcmp (&my_identity, peer_identity, sizeof (struct GNUNET_PeerIdentity)))
5373 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connected to %s\n", GNUNET_i2s (peer_identity));
5375 /* If peer already exists in our friend_peermap, then exit. */
5376 if (GNUNET_YES == GNUNET_CONTAINER_multipeermap_contains (friend_peermap,
5383 GNUNET_STATISTICS_update (GDS_stats, gettext_noop ("# peers connected"), 1,
5386 friend = GNUNET_new (struct FriendInfo);
5387 friend->id = *peer_identity;
5389 GNUNET_assert (GNUNET_OK ==
5390 GNUNET_CONTAINER_multipeermap_put (friend_peermap,
5391 peer_identity, friend,
5392 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
5395 /* got a first connection, good time to start with FIND FINGER TRAIL requests...*/
5396 if (GNUNET_SCHEDULER_NO_TASK == find_finger_trail_task)
5397 find_finger_trail_task = GNUNET_SCHEDULER_add_now (&send_find_finger_trail_message, NULL);
5402 * To be called on core init/fail.
5404 * @param cls service closure
5405 * @param identity the public identity of this peer
5408 core_init (void *cls,
5409 const struct GNUNET_PeerIdentity *identity)
5411 my_identity = *identity;
5412 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
5413 "my_indentity = %s\n",GNUNET_i2s(&my_identity));
5415 FPRINTF (stderr,_("\nSUPU %s, %s, %d, my_identity = %s"),
5416 __FILE__, __func__,__LINE__, GNUNET_i2s (&my_identity));
5422 * Initialize finger table entries.
5425 finger_table_init ()
5430 /* FIXME: here we have set the whole entry of finger table to 0, so do we
5431 * need to initialize the trails to 0 */
5432 for(i = 0; i < MAX_FINGERS; i++)
5434 finger_table[i].is_present = GNUNET_NO;
5435 for (j = 0; j < MAXIMUM_TRAILS_PER_FINGER; j++)
5436 finger_table[i].trail_list[j].is_present = GNUNET_NO;
5437 memset ((void *)&finger_table[i], 0, sizeof (finger_table[i]));
5443 * Initialize neighbours subsystem.
5444 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
5447 GDS_NEIGHBOURS_init (void)
5449 static struct GNUNET_CORE_MessageHandler core_handlers[] = {
5450 {&handle_dht_p2p_put, GNUNET_MESSAGE_TYPE_XDHT_P2P_PUT, 0},
5451 {&handle_dht_p2p_get, GNUNET_MESSAGE_TYPE_XDHT_P2P_GET, 0},
5452 {&handle_dht_p2p_get_result, GNUNET_MESSAGE_TYPE_XDHT_P2P_GET_RESULT, 0},
5453 {&handle_dht_p2p_trail_setup, GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP, 0},
5454 {&handle_dht_p2p_trail_setup_result, GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP_RESULT, 0},
5455 {&handle_dht_p2p_verify_successor, GNUNET_MESSAGE_TYPE_XDHT_P2P_VERIFY_SUCCESSOR, 0},
5456 {&handle_dht_p2p_verify_successor_result, GNUNET_MESSAGE_TYPE_XDHT_P2P_VERIFY_SUCCESSOR_RESULT, 0},
5457 {&handle_dht_p2p_notify_new_successor, GNUNET_MESSAGE_TYPE_XDHT_P2P_NOTIFY_NEW_SUCCESSOR, 0},
5458 {&handle_dht_p2p_trail_setup_rejection, GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_SETUP_REJECTION, 0},
5459 {&handle_dht_p2p_trail_compression, GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_COMPRESSION,
5460 sizeof (struct PeerTrailCompressionMessage)},
5461 {&handle_dht_p2p_trail_teardown, GNUNET_MESSAGE_TYPE_XDHT_P2P_TRAIL_TEARDOWN,
5462 sizeof (struct PeerTrailTearDownMessage)},
5463 {&handle_dht_p2p_add_trail, GNUNET_MESSAGE_TYPE_XDHT_P2P_ADD_TRAIL, 0},
5468 GNUNET_CORE_connect (GDS_cfg, NULL, &core_init, &handle_core_connect,
5469 &handle_core_disconnect, NULL, GNUNET_NO, NULL,
5470 GNUNET_NO, core_handlers);
5471 if (NULL == core_api)
5472 return GNUNET_SYSERR;
5474 friend_peermap = GNUNET_CONTAINER_multipeermap_create (256, GNUNET_NO);
5475 finger_table_init ();
5482 * Shutdown neighbours subsystem.
5485 GDS_NEIGHBOURS_done (void)
5487 if (NULL == core_api)
5490 GNUNET_CORE_disconnect (core_api);
5493 GNUNET_assert (0 == GNUNET_CONTAINER_multipeermap_size (friend_peermap));
5494 GNUNET_CONTAINER_multipeermap_destroy (friend_peermap);
5495 friend_peermap = NULL;
5497 if (GNUNET_SCHEDULER_NO_TASK != find_finger_trail_task)
5500 GNUNET_SCHEDULER_cancel (find_finger_trail_task);
5501 find_finger_trail_task = GNUNET_SCHEDULER_NO_TASK;
5509 * @return my identity
5511 struct GNUNET_PeerIdentity
5512 GDS_NEIGHBOURS_get_my_id (void)