2 This file is part of GNUnet.
3 (C) 2013 Christian Grothoff (and other contributing authors)
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6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
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22 * @file dv/gnunet-service-dv.c
23 * @brief the distance vector service, primarily handles gossip of nearby
24 * peers and sending/receiving DV messages from core and decapsulating
27 * @author Christian Grothoff
28 * @author Nathan Evans
31 * - distance updates are not properly communicate to US by core/transport/ats
34 #include "gnunet_util_lib.h"
35 #include "gnunet_protocols.h"
36 #include "gnunet_core_service.h"
37 #include "gnunet_hello_lib.h"
38 #include "gnunet_peerinfo_service.h"
39 #include "gnunet_statistics_service.h"
40 #include "gnunet_consensus_service.h"
46 * How often do we establish the consensu?
48 #define GNUNET_DV_CONSENSUS_FREQUENCY GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 5)
51 * Maximum number of messages we queue per peer.
53 #define MAX_QUEUE_SIZE 16
56 * Maximum number of messages we queue towards the clients/plugin.
58 #define MAX_QUEUE_SIZE_PLUGIN 1024
61 * The default fisheye depth, from how many hops away will
64 #define DEFAULT_FISHEYE_DEPTH 3
67 * How many hops is a direct neighbor away?
69 #define DIRECT_NEIGHBOR_COST 1
72 GNUNET_NETWORK_STRUCT_BEGIN
75 * Information about a peer DV can route to. These entries are what
76 * we use as the binary format to establish consensus to create our
77 * routing table and as the address format in the HELLOs.
83 * Identity of the peer we can reach.
85 struct GNUNET_PeerIdentity peer;
88 * How many hops (1-3) is this peer away? in network byte order
90 uint32_t distance GNUNET_PACKED;
96 * Message exchanged between DV services (via core), requesting a
97 * message to be routed.
102 * Type: GNUNET_MESSAGE_TYPE_DV_ROUTE
104 struct GNUNET_MessageHeader header;
107 * Expected (remaining) distance. Must be always smaller than
108 * DEFAULT_FISHEYE_DEPTH, should be zero at the target. Must
109 * be decremented by one at each hop. Peers must not forward
110 * these messages further once the counter has reached zero.
112 uint32_t distance GNUNET_PACKED;
115 * The (actual) target of the message (this peer, if distance is zero).
117 struct GNUNET_PeerIdentity target;
120 * The (actual) sender of the message.
122 struct GNUNET_PeerIdentity sender;
126 GNUNET_NETWORK_STRUCT_END
130 * Linked list of messages to send to clients.
132 struct PendingMessage
135 * Pointer to next item in the list
137 struct PendingMessage *next;
140 * Pointer to previous item in the list
142 struct PendingMessage *prev;
145 * Actual message to be sent, allocated after this struct.
147 const struct GNUNET_MessageHeader *msg;
150 * Ultimate target for the message.
152 struct GNUNET_PeerIdentity ultimate_target;
155 * Unique ID of the message.
163 * Information about a direct neighbor (core-level, excluding
164 * DV-links, only DV-enabled peers).
166 struct DirectNeighbor
170 * Identity of the peer.
172 struct GNUNET_PeerIdentity peer;
175 * Head of linked list of messages to send to this peer.
177 struct PendingMessage *pm_head;
180 * Tail of linked list of messages to send to this peer.
182 struct PendingMessage *pm_tail;
185 * Transmit handle to core service.
187 struct GNUNET_CORE_TransmitHandle *cth;
190 * Routing table of the neighbor, NULL if not yet established.
191 * Keys are peer identities, values are 'struct Target' entries.
192 * Note that the distances in the targets are from the point-of-view
193 * of the peer, not from us!
195 struct GNUNET_CONTAINER_MultiHashMap *neighbor_table;
198 * Updated routing table of the neighbor, under construction,
199 * NULL if we are not currently building it.
200 * Keys are peer identities, values are 'struct Target' entries.
201 * Note that the distances in the targets are from the point-of-view
202 * of the peer, not from us!
204 struct GNUNET_CONTAINER_MultiHashMap *neighbor_table_consensus;
207 * Active consensus, if we are currently synchronizing the
210 struct GNUNET_CONSENSUS_Handle *consensus;
213 * ID of the task we use to (periodically) update our consensus
216 GNUNET_SCHEDULER_TaskIdentifier consensus_task;
219 * At what offset are we, with respect to inserting our own routes
220 * into the consensus?
222 unsigned int consensus_insertion_offset;
225 * At what distance are we, with respect to inserting our own routes
226 * into the consensus?
228 unsigned int consensus_insertion_distance;
231 * Number of messages currently in the 'pm_XXXX'-DLL.
233 unsigned int pm_queue_size;
236 * Flag set within 'check_target_removed' to trigger full global route refresh.
244 * A route includes information about the next hop,
245 * the target, and the ultimate distance to the
252 * Which peer do we need to forward the message to?
254 struct DirectNeighbor *next_hop;
257 * What would be the target, and how far is it away?
259 struct Target target;
262 * Offset of this target in the respective consensus set.
264 unsigned int set_offset;
270 * Set of targets we bring to a consensus; all targets in a set have a
271 * distance equal to the sets distance (which is implied by the array
278 * Array of targets in the set, may include NULL entries if a
279 * neighbor has disconnected; the targets are allocated with the
280 * respective container (all_routes), not here.
282 struct Route **targets;
285 * Size of the 'targets' array.
287 unsigned int array_length;
293 * Hashmap of all of our direct neighbors (no DV routing).
295 static struct GNUNET_CONTAINER_MultiHashMap *direct_neighbors;
298 * Hashmap with all routes that we currently support; contains
299 * routing information for all peers from distance 2
300 * up to distance DEFAULT_FISHEYE_DEPTH.
302 static struct GNUNET_CONTAINER_MultiHashMap *all_routes;
305 * Array of consensus sets we expose to the outside world. Sets
306 * are structured by the distance to the target.
308 static struct ConsensusSet consensi[DEFAULT_FISHEYE_DEPTH - 1];
311 * Handle to the core service api.
313 static struct GNUNET_CORE_Handle *core_api;
316 * The identity of our peer.
318 static struct GNUNET_PeerIdentity my_identity;
321 * The configuration for this service.
323 static const struct GNUNET_CONFIGURATION_Handle *cfg;
326 * The client, the DV plugin connected to us (or an event monitor).
327 * Hopefully this client will never change, although if the plugin
328 * dies and returns for some reason it may happen.
330 static struct GNUNET_SERVER_NotificationContext *nc;
333 * Handle for the statistics service.
335 struct GNUNET_STATISTICS_Handle *stats;
339 * Get distance information from 'atsi'.
341 * @param atsi performance data
342 * @param atsi_count number of entries in atsi
343 * @return connected transport distance
346 get_atsi_distance (const struct GNUNET_ATS_Information *atsi,
347 unsigned int atsi_count)
351 for (i = 0; i < atsi_count; i++)
352 if (ntohl (atsi[i].type) == GNUNET_ATS_QUALITY_NET_DISTANCE)
353 return ntohl (atsi->value);
354 /* FIXME: we do not have distance data? Assume direct neighbor. */
355 return DIRECT_NEIGHBOR_COST;
360 * Forward a message from another peer to the plugin.
362 * @param message the message to send to the plugin
363 * @param origin the original sender of the message
364 * @param distance distance to the original sender of the message
367 send_data_to_plugin (const struct GNUNET_MessageHeader *message,
368 const struct GNUNET_PeerIdentity *origin,
371 struct GNUNET_DV_ReceivedMessage *received_msg;
374 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
375 "Delivering message from peer `%s'\n",
376 GNUNET_i2s (origin));
377 size = sizeof (struct GNUNET_DV_ReceivedMessage) +
378 ntohs (message->size);
379 if (size >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
381 GNUNET_break (0); /* too big */
384 received_msg = GNUNET_malloc (size);
385 received_msg->header.size = htons (size);
386 received_msg->header.type = htons (GNUNET_MESSAGE_TYPE_DV_RECV);
387 received_msg->distance = htonl (distance);
388 received_msg->sender = *origin;
389 memcpy (&received_msg[1], message, ntohs (message->size));
390 GNUNET_SERVER_notification_context_broadcast (nc,
391 &received_msg->header,
393 GNUNET_free (received_msg);
398 * Forward a control message to the plugin.
400 * @param message the message to send to the plugin
403 send_control_to_plugin (const struct GNUNET_MessageHeader *message)
405 GNUNET_SERVER_notification_context_broadcast (nc,
412 * Give an (N)ACK message to the plugin, we transmitted a message for it.
414 * @param target peer that received the message
415 * @param uid plugin-chosen UID for the message
416 * @param nack GNUNET_NO to send ACK, GNUNET_YES to send NACK
419 send_ack_to_plugin (const struct GNUNET_PeerIdentity *target,
423 struct GNUNET_DV_AckMessage ack_msg;
425 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
426 "Delivering ACK for message to peer `%s'\n",
427 GNUNET_i2s (target));
428 ack_msg.header.size = htons (sizeof (ack_msg));
429 ack_msg.header.type = htons ((GNUNET_YES == nack)
430 ? GNUNET_MESSAGE_TYPE_DV_SEND_NACK
431 : GNUNET_MESSAGE_TYPE_DV_SEND_ACK);
432 ack_msg.uid = htonl (uid);
433 ack_msg.target = *target;
434 send_control_to_plugin (&ack_msg.header);
439 * Send a DISTANCE_CHANGED message to the plugin.
441 * @param peer peer with a changed distance
442 * @param distance new distance to the peer
445 send_distance_change_to_plugin (const struct GNUNET_PeerIdentity *peer,
448 struct GNUNET_DV_DistanceUpdateMessage du_msg;
450 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
451 "Delivering DISTANCE_CHANGED for message about peer `%s'\n",
453 du_msg.header.size = htons (sizeof (du_msg));
454 du_msg.header.type = htons (GNUNET_MESSAGE_TYPE_DV_DISTANCE_CHANGED);
455 du_msg.distance = htonl (distance);
457 send_control_to_plugin (&du_msg.header);
462 * Give a CONNECT message to the plugin.
464 * @param target peer that connected
465 * @param distance distance to the target
468 send_connect_to_plugin (const struct GNUNET_PeerIdentity *target,
471 struct GNUNET_DV_ConnectMessage cm;
473 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
474 "Delivering CONNECT about peer `%s'\n",
475 GNUNET_i2s (target));
476 cm.header.size = htons (sizeof (cm));
477 cm.header.type = htons (GNUNET_MESSAGE_TYPE_DV_CONNECT);
478 cm.distance = htonl (distance);
480 send_control_to_plugin (&cm.header);
485 * Give a DISCONNECT message to the plugin.
487 * @param target peer that disconnected
490 send_disconnect_to_plugin (const struct GNUNET_PeerIdentity *target)
492 struct GNUNET_DV_DisconnectMessage dm;
494 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
495 "Delivering DISCONNECT about peer `%s'\n",
496 GNUNET_i2s (target));
497 dm.header.size = htons (sizeof (dm));
498 dm.header.type = htons (GNUNET_MESSAGE_TYPE_DV_DISCONNECT);
499 dm.reserved = htonl (0);
501 send_control_to_plugin (&dm.header);
506 * Function called to transfer a message to another peer
509 * @param cls closure with the direct neighbor
510 * @param size number of bytes available in buf
511 * @param buf where the callee should write the message
512 * @return number of bytes written to buf
515 core_transmit_notify (void *cls, size_t size, void *buf)
517 struct DirectNeighbor *dn = cls;
519 struct PendingMessage *pending;
526 /* peer disconnected */
530 pending = dn->pm_head;
532 while ( (NULL != (pending = dn->pm_head)) &&
533 (size >= off + (msize = ntohs (pending->msg->size))))
536 GNUNET_CONTAINER_DLL_remove (dn->pm_head,
539 memcpy (&cbuf[off], pending->msg, msize);
540 if (0 != pending->uid)
541 send_ack_to_plugin (&pending->ultimate_target,
544 GNUNET_free (pending);
547 if (NULL != dn->pm_head)
549 GNUNET_CORE_notify_transmit_ready (core_api,
550 GNUNET_YES /* cork */,
552 GNUNET_TIME_UNIT_FOREVER_REL,
555 &core_transmit_notify, dn);
561 * Forward the given payload to the given target.
563 * @param target where to send the message
564 * @param uid unique ID for the message
565 * @param ultimate_target ultimate recipient for the message
566 * @param distance expected (remaining) distance to the target
567 * @param sender original sender of the message
568 * @param payload payload of the message
571 forward_payload (struct DirectNeighbor *target,
574 const struct GNUNET_PeerIdentity *sender,
575 const struct GNUNET_PeerIdentity *ultimate_target,
576 const struct GNUNET_MessageHeader *payload)
578 struct PendingMessage *pm;
579 struct RouteMessage *rm;
582 if ( (target->pm_queue_size >= MAX_QUEUE_SIZE) &&
583 (0 != memcmp (sender,
585 sizeof (struct GNUNET_PeerIdentity))) )
587 GNUNET_break (0 == uid);
590 msize = sizeof (struct RouteMessage) + ntohs (payload->size);
591 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
596 pm = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
597 pm->ultimate_target = *ultimate_target;
599 pm->msg = (const struct GNUNET_MessageHeader *) &pm[1];
600 rm = (struct RouteMessage *) &pm[1];
601 rm->header.size = htons ((uint16_t) msize);
602 rm->header.type = htons (GNUNET_MESSAGE_TYPE_DV_ROUTE);
603 rm->distance = htonl (distance);
604 rm->target = target->peer;
605 rm->sender = *sender;
606 memcpy (&rm[1], payload, ntohs (payload->size));
607 GNUNET_CONTAINER_DLL_insert_tail (target->pm_head,
610 target->pm_queue_size++;
611 if (NULL == target->cth)
612 target->cth = GNUNET_CORE_notify_transmit_ready (core_api,
613 GNUNET_YES /* cork */,
615 GNUNET_TIME_UNIT_FOREVER_REL,
618 &core_transmit_notify, target);
623 * Find a free slot for storing a 'route' in the 'consensi'
624 * set at the given distance.
626 * @param distance distance to use for the set slot
629 get_consensus_slot (uint32_t distance)
631 struct ConsensusSet *cs;
634 cs = &consensi[distance];
636 while ( (i < cs->array_length) &&
637 (NULL != cs->targets[i]) ) i++;
638 if (i == cs->array_length)
639 GNUNET_array_grow (cs->targets,
641 cs->array_length * 2 + 2);
647 * Allocate a slot in the consensus set for a route.
649 * @param route route to initialize
650 * @param distance which consensus set to use
653 allocate_route (struct Route *route,
658 i = get_consensus_slot (distance);
659 route->set_offset = i;
660 consensi[distance].targets[i] = route;
661 route->target.distance = htonl (distance);
666 * Release a slot in the consensus set for a route.
668 * @param route route to release the slot from
671 release_route (struct Route *route)
673 consensi[ntohl (route->target.distance)].targets[route->set_offset] = NULL;
674 route->set_offset = UINT_MAX; /* indicate invalid slot */
679 * Move a route from one consensus set to another.
681 * @param route route to move
682 * @param new_distance new distance for the route (destination set)
685 move_route (struct Route *route,
686 uint32_t new_distance)
690 release_route (route);
691 i = get_consensus_slot (new_distance);
692 route->set_offset = i;
693 consensi[new_distance].targets[i] = route;
694 route->target.distance = htonl (new_distance);
699 * Start creating a new consensus from scratch.
701 * @param cls the 'struct DirectNeighbor' of the peer we're building
702 * a routing consensus with
703 * @param tc scheduler context
706 start_consensus (void *cls,
707 const struct GNUNET_SCHEDULER_TaskContext *tc);
711 * Method called whenever a peer connects.
714 * @param peer peer identity this notification is about
715 * @param atsi performance data
716 * @param atsi_count number of entries in atsi
719 handle_core_connect (void *cls, const struct GNUNET_PeerIdentity *peer,
720 const struct GNUNET_ATS_Information *atsi,
721 unsigned int atsi_count)
723 struct DirectNeighbor *neighbor;
727 /* Check for connect to self message */
728 if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
730 distance = get_atsi_distance (atsi, atsi_count);
731 neighbor = GNUNET_CONTAINER_multihashmap_get (direct_neighbors,
733 if (NULL != neighbor)
738 if (DIRECT_NEIGHBOR_COST != distance)
739 return; /* is a DV-neighbor */
740 GNUNET_STATISTICS_update (stats,
741 "# peers connected (1-hop)",
743 neighbor = GNUNET_malloc (sizeof (struct DirectNeighbor));
744 neighbor->peer = *peer;
745 GNUNET_assert (GNUNET_YES ==
746 GNUNET_CONTAINER_multihashmap_put (direct_neighbors,
749 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
750 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
754 send_disconnect_to_plugin (peer);
755 release_route (route);
758 neighbor->consensus_task = GNUNET_SCHEDULER_add_now (&start_consensus,
764 * Called for each 'target' in a neighbor table to free the associated memory.
767 * @param key key of the value
768 * @param value value to free
769 * @return GNUNET_OK to continue to iterate
772 free_targets (void *cls,
773 const struct GNUNET_HashCode *key,
782 * Multihashmap iterator for checking if a given route is
783 * (now) useful to this peer.
785 * @param cls the direct neighbor for the given route
786 * @param key key value stored under
787 * @param value a 'struct Target' that may or may not be useful; not that
788 * the distance in 'target' does not include the first hop yet
789 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
792 check_possible_route (void *cls, const struct GNUNET_HashCode * key, void *value)
794 struct DirectNeighbor *neighbor = cls;
795 struct Target *target = value;
798 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
802 if (ntohl (route->target.distance) > ntohl (target->distance) + 1)
804 /* this 'target' is cheaper than the existing route; switch to alternative route! */
805 move_route (route, ntohl (target->distance) + 1);
806 route->next_hop = neighbor;
807 send_distance_change_to_plugin (&target->peer, ntohl (target->distance) + 1);
809 return GNUNET_YES; /* got a route to this target already */
811 route = GNUNET_malloc (sizeof (struct Route));
812 route->next_hop = neighbor;
813 route->target.distance = htonl (ntohl (target->distance) + 1);
814 route->target.peer = target->peer;
815 allocate_route (route, ntohl (route->target.distance));
816 GNUNET_assert (GNUNET_YES ==
817 GNUNET_CONTAINER_multihashmap_put (all_routes,
818 &route->target.peer.hashPubKey,
820 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
821 send_connect_to_plugin (&route->target.peer, ntohl (target->distance));
827 * Multihashmap iterator for finding routes that were previously
828 * "hidden" due to a better route (called after a disconnect event).
831 * @param key peer identity of the given direct neighbor
832 * @param value a 'struct DirectNeighbor' to check for additional routes
833 * @return GNUNET_YES to continue iteration
836 refresh_routes (void *cls, const struct GNUNET_HashCode * key, void *value)
838 struct DirectNeighbor *neighbor = value;
840 if (NULL != neighbor->neighbor_table)
841 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table,
842 &check_possible_route,
849 * Check if a target was removed from the set of the other peer; if so,
850 * if we also used it for our route, we need to remove it from our
851 * 'all_routes' set (and later check if an alternative path now exists).
853 * @param cls the 'struct DirectNeighbor'
854 * @param key peer identity for the target
855 * @param value a 'struct Target' previously reachable via the given neighbor
858 check_target_removed (void *cls,
859 const struct GNUNET_HashCode *key,
862 struct DirectNeighbor *neighbor = cls;
863 struct Target *new_target;
864 struct Route *current_route;
866 new_target = GNUNET_CONTAINER_multihashmap_get (neighbor->neighbor_table_consensus,
868 if (NULL == new_target)
870 /* target was revoked, check if it was used */
871 current_route = GNUNET_CONTAINER_multihashmap_get (all_routes,
873 if ( (NULL == current_route) ||
874 (current_route->next_hop != neighbor) )
876 /* didn't matter, wasn't used */
879 /* remove existing route */
880 GNUNET_assert (GNUNET_YES ==
881 GNUNET_CONTAINER_multihashmap_remove (all_routes, key, current_route));
882 send_disconnect_to_plugin (¤t_route->target.peer);
883 GNUNET_free (current_route);
884 neighbor->target_removed = GNUNET_YES;
892 * Check if a target was added to the set of the other peer; if it
893 * was added or impoves the existing route, do the needed updates.
895 * @param cls the 'struct DirectNeighbor'
896 * @param key peer identity for the target
897 * @param value a 'struct Target' now reachable via the given neighbor
900 check_target_added (void *cls,
901 const struct GNUNET_HashCode *key,
904 struct DirectNeighbor *neighbor = cls;
905 struct Target *target = value;
906 struct Route *current_route;
908 /* target was revoked, check if it was used */
909 current_route = GNUNET_CONTAINER_multihashmap_get (all_routes,
911 if (NULL != current_route)
914 if (current_route->next_hop == neighbor)
916 /* we had the same route before, no change */
917 if (ntohl (target->distance) + 1 != ntohl (current_route->target.distance))
919 current_route->target.distance = htonl (ntohl (target->distance) + 1);
920 send_distance_change_to_plugin (&target->peer, ntohl (target->distance) + 1);
924 if (ntohl (current_route->target.distance) >= ntohl (target->distance) + 1)
926 /* alternative, shorter route exists, ignore */
929 /* new route is better than the existing one, take over! */
930 /* NOTE: minor security issue: malicious peers may advertise
931 very short routes to take over longer paths; as we don't
932 check that the shorter routes actually work, a malicious
933 direct neighbor can use this to DoS our long routes */
934 current_route->next_hop = neighbor;
935 current_route->target.distance = htonl (ntohl (target->distance) + 1);
936 send_distance_change_to_plugin (&target->peer, ntohl (target->distance) + 1);
940 current_route = GNUNET_malloc (sizeof (struct Route));
941 current_route->next_hop = neighbor;
942 current_route->target.peer = target->peer;
943 current_route->target.distance = htonl (ntohl (target->distance) + 1);
944 GNUNET_assert (GNUNET_YES ==
945 GNUNET_CONTAINER_multihashmap_put (all_routes,
946 ¤t_route->target.peer.hashPubKey,
948 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
949 send_connect_to_plugin (¤t_route->target.peer,
950 ntohl (current_route->target.distance));
957 * The consensus has concluded, clean up and schedule the next one.
959 * @param cls the 'struct GNUNET_DirectNeighbor' with which we created the consensus
963 consensus_done_cb (void *cls,
964 const struct GNUNET_CONSENSUS_Group *group)
966 struct DirectNeighbor *neighbor = cls;
968 GNUNET_CONSENSUS_destroy (neighbor->consensus);
969 neighbor->consensus = NULL;
970 /* remove targets that disappeared */
971 neighbor->target_removed = GNUNET_NO;
972 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table,
973 &check_target_removed,
975 if (GNUNET_YES == neighbor->target_removed)
977 /* check if we got an alternative for the removed routes */
978 GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
982 /* add targets that appeared (and check for improved routes) */
983 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table_consensus,
986 if (NULL != neighbor->neighbor_table)
988 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table,
991 GNUNET_CONTAINER_multihashmap_destroy (neighbor->neighbor_table);
992 neighbor->neighbor_table = NULL;
994 neighbor->neighbor_table = neighbor->neighbor_table_consensus;
995 neighbor->neighbor_table_consensus = NULL;
996 neighbor->consensus_task = GNUNET_SCHEDULER_add_delayed (GNUNET_DV_CONSENSUS_FREQUENCY,
1003 * We inserted the last element into the consensus, get ready to
1004 * insert the next element into the consensus or conclude if
1007 * @param cls the 'struct DirectNeighbor' of the peer we're building
1008 * a routing consensus with
1009 * @param success GNUNET_OK if the last element was added successfully,
1010 * GNUNET_SYSERR if we failed
1013 insert_next_element (void *cls,
1016 struct DirectNeighbor *neighbor = cls;
1017 struct GNUNET_CONSENSUS_Element element;
1019 while ( (DEFAULT_FISHEYE_DEPTH - 1 > neighbor->consensus_insertion_distance) &&
1020 (consensi[neighbor->consensus_insertion_distance].array_length == neighbor->consensus_insertion_offset) )
1022 neighbor->consensus_insertion_offset = 0;
1023 neighbor->consensus_insertion_distance++;
1024 /* skip over NULL entries */
1025 while ( (DEFAULT_FISHEYE_DEPTH - 1 > neighbor->consensus_insertion_distance) &&
1026 (consensi[neighbor->consensus_insertion_distance].array_length < neighbor->consensus_insertion_offset) &&
1027 (NULL == consensi[neighbor->consensus_insertion_distance].targets[neighbor->consensus_insertion_offset]) )
1028 neighbor->consensus_insertion_offset++;
1030 if (DEFAULT_FISHEYE_DEPTH - 1 == neighbor->consensus_insertion_distance)
1032 /* we're done, conclude! */
1033 GNUNET_CONSENSUS_conclude (neighbor->consensus,
1034 GNUNET_DV_CONSENSUS_FREQUENCY,
1040 element.size = sizeof (struct Target);
1041 element.data = &consensi[neighbor->consensus_insertion_distance].targets[neighbor->consensus_insertion_offset++]->target;
1043 /* skip over NULL entries */
1044 while ( (DEFAULT_FISHEYE_DEPTH - 1 > neighbor->consensus_insertion_distance) &&
1045 (consensi[neighbor->consensus_insertion_distance].array_length < neighbor->consensus_insertion_offset) &&
1046 (NULL == consensi[neighbor->consensus_insertion_distance].targets[neighbor->consensus_insertion_offset]) )
1047 neighbor->consensus_insertion_offset++;
1048 GNUNET_CONSENSUS_insert (neighbor->consensus,
1050 &insert_next_element,
1056 * We have learned a new route from the other peer. Add it to the
1057 * route set we're building.
1059 * @param cls the 'struct DirectNeighbor' we're building the consensus with
1060 * @param element the new element we have learned
1061 * @return GNUNET_OK if the valid is well-formed and should be added to the consensus,
1062 * GNUNET_SYSERR if the element should be ignored and not be propagated
1065 learn_route_cb (void *cls,
1066 const struct GNUNET_CONSENSUS_Element *element)
1068 struct DirectNeighbor *neighbor = cls;
1069 struct Target *target;
1071 if (NULL == element)
1073 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1074 "Failed to establish DV consensus, will try again later\n");
1075 GNUNET_CONSENSUS_destroy (neighbor->consensus);
1076 if (NULL != neighbor->neighbor_table_consensus)
1078 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table_consensus,
1081 GNUNET_CONTAINER_multihashmap_destroy (neighbor->neighbor_table_consensus);
1082 neighbor->neighbor_table_consensus = NULL;
1084 neighbor->consensus = NULL;
1085 neighbor->consensus_task = GNUNET_SCHEDULER_add_delayed (GNUNET_DV_CONSENSUS_FREQUENCY,
1088 return GNUNET_SYSERR;
1090 if (sizeof (struct Target) != element->size)
1092 GNUNET_break_op (0);
1093 return GNUNET_SYSERR;
1095 target = GNUNET_malloc (sizeof (struct Target));
1096 memcpy (target, element->data, sizeof (struct Target));
1098 GNUNET_CONTAINER_multihashmap_put (neighbor->neighbor_table_consensus,
1099 &target->peer.hashPubKey,
1101 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
1103 GNUNET_break_op (0);
1104 GNUNET_free (target);
1105 return GNUNET_SYSERR;
1112 * Start creating a new consensus from scratch.
1114 * @param cls the 'struct DirectNeighbor' of the peer we're building
1115 * a routing consensus with
1116 * @param tc scheduler context
1119 start_consensus (void *cls,
1120 const struct GNUNET_SCHEDULER_TaskContext *tc)
1122 struct DirectNeighbor *neighbor = cls;
1123 struct GNUNET_HashCode session_id;
1124 struct GNUNET_HashCode real_session_id;
1126 neighbor->consensus_task = GNUNET_SCHEDULER_NO_TASK;
1127 neighbor->consensus_insertion_offset = 0;
1128 neighbor->consensus_insertion_distance = 0;
1129 GNUNET_assert (NULL == neighbor->neighbor_table_consensus);
1130 GNUNET_assert (NULL == neighbor->consensus);
1131 neighbor->neighbor_table_consensus = GNUNET_CONTAINER_multihashmap_create (1024, GNUNET_YES);
1132 /* construct session ID seed as XOR of both peer's identities */
1133 GNUNET_CRYPTO_hash_xor (&my_identity.hashPubKey,
1134 &neighbor->peer.hashPubKey,
1136 /* make sure session ID is unique across applications by salting it with 'DV' */
1137 GNUNET_CRYPTO_hkdf (&real_session_id, sizeof (real_session_id),
1138 GCRY_MD_SHA512, GCRY_MD_SHA256,
1140 &session_id, sizeof (session_id),
1142 neighbor->consensus = GNUNET_CONSENSUS_create (cfg,
1148 if (NULL == neighbor->consensus)
1150 neighbor->consensus_task = GNUNET_SCHEDULER_add_delayed (GNUNET_DV_CONSENSUS_FREQUENCY,
1155 insert_next_element (neighbor, GNUNET_OK);
1160 * Core handler for DV data messages. Whatever this message
1161 * contains all we really have to do is rip it out of its
1162 * DV layering and give it to our pal the DV plugin to report
1165 * @param cls closure
1166 * @param peer peer which sent the message (immediate sender)
1167 * @param message the message
1168 * @param atsi transport ATS information (latency, distance, etc.)
1169 * @param atsi_count number of entries in atsi
1170 * @return GNUNET_OK on success, GNUNET_SYSERR if the other peer violated the protocol
1173 handle_dv_route_message (void *cls, const struct GNUNET_PeerIdentity *peer,
1174 const struct GNUNET_MessageHeader *message,
1175 const struct GNUNET_ATS_Information *atsi,
1176 unsigned int atsi_count)
1178 const struct RouteMessage *rm;
1179 const struct GNUNET_MessageHeader *payload;
1180 struct Route *route;
1182 if (ntohs (message->size) < sizeof (struct RouteMessage) + sizeof (struct GNUNET_MessageHeader))
1184 GNUNET_break_op (0);
1185 return GNUNET_SYSERR;
1187 rm = (const struct RouteMessage *) message;
1188 payload = (const struct GNUNET_MessageHeader *) &rm[1];
1189 if (ntohs (message->size) != sizeof (struct RouteMessage) + ntohs (payload->size))
1191 GNUNET_break_op (0);
1192 return GNUNET_SYSERR;
1194 if (0 == memcmp (&rm->target,
1196 sizeof (struct GNUNET_PeerIdentity)))
1198 /* message is for me, check reverse route! */
1199 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
1200 &rm->sender.hashPubKey);
1203 /* don't have reverse route, drop */
1204 GNUNET_STATISTICS_update (stats,
1205 "# message discarded (no reverse route)",
1209 send_data_to_plugin (payload,
1211 ntohl (route->target.distance));
1214 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
1215 &rm->target.hashPubKey);
1218 GNUNET_STATISTICS_update (stats,
1219 "# messages discarded (no route)",
1223 if (ntohl (route->target.distance) > ntohl (rm->distance) + 1)
1225 GNUNET_STATISTICS_update (stats,
1226 "# messages discarded (target too far)",
1230 forward_payload (route->next_hop,
1231 ntohl (route->target.distance),
1241 * Service server's handler for message send requests (which come
1242 * bubbling up to us through the DV plugin).
1244 * @param cls closure
1245 * @param client identification of the client
1246 * @param message the actual message
1249 handle_dv_send_message (void *cls, struct GNUNET_SERVER_Client *client,
1250 const struct GNUNET_MessageHeader *message)
1252 struct Route *route;
1253 const struct GNUNET_DV_SendMessage *msg;
1254 const struct GNUNET_MessageHeader *payload;
1256 if (ntohs (message->size) < sizeof (struct GNUNET_DV_SendMessage) + sizeof (struct GNUNET_MessageHeader))
1259 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1262 msg = (const struct GNUNET_DV_SendMessage *) message;
1263 GNUNET_break (0 != ntohl (msg->uid));
1264 payload = (const struct GNUNET_MessageHeader *) &msg[1];
1265 if (ntohs (message->size) != sizeof (struct GNUNET_DV_SendMessage) + ntohs (payload->size))
1268 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1271 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
1272 &msg->target.hashPubKey);
1275 /* got disconnected */
1276 GNUNET_STATISTICS_update (stats,
1277 "# local messages discarded (no route)",
1279 send_ack_to_plugin (&msg->target, ntohl (msg->uid), GNUNET_YES);
1280 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1283 forward_payload (route->next_hop,
1284 ntohl (route->target.distance),
1289 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1294 * Multihashmap iterator for freeing routes that go via a particular
1295 * neighbor that disconnected and is thus no longer available.
1297 * @param cls the direct neighbor that is now unavailable
1298 * @param key key value stored under
1299 * @param value a 'struct Route' that may or may not go via neighbor
1301 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
1304 cull_routes (void *cls, const struct GNUNET_HashCode * key, void *value)
1306 struct DirectNeighbor *neighbor = cls;
1307 struct Route *route = value;
1309 if (route->next_hop != neighbor)
1310 return GNUNET_YES; /* not affected */
1311 GNUNET_assert (GNUNET_YES ==
1312 GNUNET_CONTAINER_multihashmap_remove (all_routes, key, value));
1313 release_route (route);
1314 send_disconnect_to_plugin (&route->target.peer);
1315 GNUNET_free (route);
1321 * Cleanup all of the data structures associated with a given neighbor.
1323 * @param neighbor neighbor to clean up
1326 cleanup_neighbor (struct DirectNeighbor *neighbor)
1328 struct PendingMessage *pending;
1330 while (NULL != (pending = neighbor->pm_head))
1332 neighbor->pm_queue_size--;
1333 GNUNET_CONTAINER_DLL_remove (neighbor->pm_head,
1336 GNUNET_free (pending);
1338 GNUNET_CONTAINER_multihashmap_iterate (all_routes,
1341 if (NULL != neighbor->cth)
1343 GNUNET_CORE_notify_transmit_ready_cancel (neighbor->cth);
1344 neighbor->cth = NULL;
1346 if (NULL != neighbor->neighbor_table_consensus)
1348 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table_consensus,
1351 GNUNET_CONTAINER_multihashmap_destroy (neighbor->neighbor_table_consensus);
1352 neighbor->neighbor_table_consensus = NULL;
1354 if (NULL != neighbor->neighbor_table)
1356 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table,
1359 GNUNET_CONTAINER_multihashmap_destroy (neighbor->neighbor_table);
1360 neighbor->neighbor_table = NULL;
1362 if (GNUNET_SCHEDULER_NO_TASK != neighbor->consensus_task)
1364 GNUNET_SCHEDULER_cancel (neighbor->consensus_task);
1365 neighbor->consensus_task = GNUNET_SCHEDULER_NO_TASK;
1367 if (NULL != neighbor->consensus)
1369 GNUNET_CONSENSUS_destroy (neighbor->consensus);
1370 neighbor->consensus = NULL;
1372 GNUNET_assert (GNUNET_YES ==
1373 GNUNET_CONTAINER_multihashmap_remove (direct_neighbors,
1374 &neighbor->peer.hashPubKey,
1376 GNUNET_free (neighbor);
1381 * Method called whenever a given peer disconnects.
1383 * @param cls closure
1384 * @param peer peer identity this notification is about
1387 handle_core_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer)
1389 struct DirectNeighbor *neighbor;
1391 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1392 "Received core peer disconnect message for peer `%s'!\n",
1394 /* Check for disconnect from self message */
1395 if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
1398 GNUNET_CONTAINER_multihashmap_get (direct_neighbors, &peer->hashPubKey);
1399 if (NULL == neighbor)
1401 /* must have been a DV-neighbor, ignore */
1404 GNUNET_STATISTICS_update (stats,
1405 "# peers connected (1-hop)",
1407 cleanup_neighbor (neighbor);
1408 GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
1415 * Multihashmap iterator for freeing routes. Should never be called.
1418 * @param key key value stored under
1419 * @param value the route to be freed
1421 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
1424 free_route (void *cls, const struct GNUNET_HashCode * key, void *value)
1426 struct Route *route = value;
1429 GNUNET_assert (GNUNET_YES ==
1430 GNUNET_CONTAINER_multihashmap_remove (all_routes, key, value));
1431 release_route (route);
1432 send_disconnect_to_plugin (&route->target.peer);
1433 GNUNET_free (route);
1439 * Multihashmap iterator for freeing direct neighbors. Should never be called.
1442 * @param key key value stored under
1443 * @param value the direct neighbor to be freed
1445 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
1448 free_direct_neighbors (void *cls, const struct GNUNET_HashCode * key, void *value)
1450 struct DirectNeighbor *neighbor = value;
1453 cleanup_neighbor (neighbor);
1459 * Task run during shutdown.
1465 shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1469 GNUNET_CORE_disconnect (core_api);
1471 GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
1472 &free_direct_neighbors, NULL);
1473 GNUNET_CONTAINER_multihashmap_iterate (all_routes,
1475 GNUNET_CONTAINER_multihashmap_destroy (direct_neighbors);
1476 GNUNET_CONTAINER_multihashmap_destroy (all_routes);
1477 GNUNET_STATISTICS_destroy (stats, GNUNET_NO);
1479 GNUNET_SERVER_notification_context_destroy (nc);
1481 for (i=0;i<DEFAULT_FISHEYE_DEPTH - 1;i++)
1482 GNUNET_array_grow (consensi[i].targets,
1483 consensi[i].array_length,
1489 * Notify newly connected client about an existing route.
1491 * @param cls the 'struct GNUNET_SERVER_Client'
1492 * @param key peer identity
1493 * @param value the XXX.
1494 * @return GNUNET_OK (continue to iterate)
1497 add_route (void *cls,
1498 const struct GNUNET_HashCode *key,
1501 struct GNUNET_SERVER_Client *client = cls;
1502 struct Route *route = value;
1503 struct GNUNET_DV_ConnectMessage cm;
1505 cm.header.size = htons (sizeof (cm));
1506 cm.header.type = htons (GNUNET_MESSAGE_TYPE_DV_CONNECT);
1507 cm.distance = htonl (route->target.distance);
1508 cm.peer = route->target.peer;
1510 GNUNET_SERVER_notification_context_unicast (nc,
1519 * Handle START-message. This is the first message sent to us
1520 * by the client (can only be one!).
1522 * @param cls closure (always NULL)
1523 * @param client identification of the client
1524 * @param message the actual message
1527 handle_start (void *cls, struct GNUNET_SERVER_Client *client,
1528 const struct GNUNET_MessageHeader *message)
1530 GNUNET_SERVER_notification_context_add (nc, client);
1531 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1532 GNUNET_CONTAINER_multihashmap_iterate (all_routes,
1539 * Called on core init.
1542 * @param server legacy
1543 * @param identity this peer's identity
1546 core_init (void *cls, struct GNUNET_CORE_Handle *server,
1547 const struct GNUNET_PeerIdentity *identity)
1549 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1551 GNUNET_i2s (identity));
1552 my_identity = *identity;
1557 * Process dv requests.
1559 * @param cls closure
1560 * @param server the initialized server
1561 * @param c configuration to use
1564 run (void *cls, struct GNUNET_SERVER_Handle *server,
1565 const struct GNUNET_CONFIGURATION_Handle *c)
1567 static struct GNUNET_CORE_MessageHandler core_handlers[] = {
1568 {&handle_dv_route_message, GNUNET_MESSAGE_TYPE_DV_ROUTE, 0},
1571 static struct GNUNET_SERVER_MessageHandler plugin_handlers[] = {
1572 {&handle_start, NULL,
1573 GNUNET_MESSAGE_TYPE_DV_START,
1574 sizeof (struct GNUNET_MessageHeader) },
1575 { &handle_dv_send_message, NULL,
1576 GNUNET_MESSAGE_TYPE_DV_SEND,
1582 direct_neighbors = GNUNET_CONTAINER_multihashmap_create (128, GNUNET_NO);
1583 all_routes = GNUNET_CONTAINER_multihashmap_create (65536, GNUNET_NO);
1584 core_api = GNUNET_CORE_connect (cfg, NULL,
1586 &handle_core_connect,
1587 &handle_core_disconnect,
1592 if (NULL == core_api)
1594 nc = GNUNET_SERVER_notification_context_create (server,
1595 MAX_QUEUE_SIZE_PLUGIN);
1596 stats = GNUNET_STATISTICS_create ("dv", cfg);
1597 GNUNET_SERVER_add_handlers (server, plugin_handlers);
1598 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
1599 &shutdown_task, NULL);
1604 * The main function for the dv service.
1606 * @param argc number of arguments from the command line
1607 * @param argv command line arguments
1608 * @return 0 ok, 1 on error
1611 main (int argc, char *const *argv)
1613 return (GNUNET_OK ==
1614 GNUNET_SERVICE_run (argc, argv, "dv", GNUNET_SERVICE_OPTION_NONE,
1615 &run, NULL)) ? 0 : 1;
1618 /* end of gnunet-service-dv.c */