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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11 WITHOUT ANY WARRANTY; without even the implied warranty of
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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 distnace 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
401 * @param distant_neighbor the original sender of the message
402 * @param distnace distance to the original sender of the message
405 send_control_to_plugin (const struct GNUNET_MessageHeader *message)
407 GNUNET_SERVER_notification_context_broadcast (nc,
414 * Give an (N)ACK message to the plugin, we transmitted a message for it.
416 * @param target peer that received the message
417 * @param uid plugin-chosen UID for the message
418 * @param nack GNUNET_NO to send ACK, GNUNET_YES to send NACK
421 send_ack_to_plugin (const struct GNUNET_PeerIdentity *target,
425 struct GNUNET_DV_AckMessage ack_msg;
427 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
428 "Delivering ACK for message to peer `%s'\n",
429 GNUNET_i2s (target));
430 ack_msg.header.size = htons (sizeof (ack_msg));
431 ack_msg.header.type = htons ((GNUNET_YES == nack)
432 ? GNUNET_MESSAGE_TYPE_DV_SEND_NACK
433 : GNUNET_MESSAGE_TYPE_DV_SEND_ACK);
434 ack_msg.uid = htonl (uid);
435 ack_msg.target = *target;
436 send_control_to_plugin (&ack_msg.header);
441 * Send a DISTANCE_CHANGED message to the plugin.
443 * @param peer peer with a changed distance
444 * @param distance new distance to the peer
447 send_distance_change_to_plugin (const struct GNUNET_PeerIdentity *peer,
450 struct GNUNET_DV_DistanceUpdateMessage du_msg;
452 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
453 "Delivering DISTANCE_CHANGED for message about peer `%s'\n",
455 du_msg.header.size = htons (sizeof (du_msg));
456 du_msg.header.type = htons (GNUNET_MESSAGE_TYPE_DV_DISTANCE_CHANGED);
457 du_msg.distance = htonl (distance);
459 send_control_to_plugin (&du_msg.header);
464 * Give a CONNECT message to the plugin.
466 * @param target peer that connected
467 * @param distance distance to the target
470 send_connect_to_plugin (const struct GNUNET_PeerIdentity *target,
473 struct GNUNET_DV_ConnectMessage cm;
475 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
476 "Delivering CONNECT about peer `%s'\n",
477 GNUNET_i2s (target));
478 cm.header.size = htons (sizeof (cm));
479 cm.header.type = htons (GNUNET_MESSAGE_TYPE_DV_CONNECT);
480 cm.distance = htonl (distance);
482 send_control_to_plugin (&cm.header);
487 * Give a DISCONNECT message to the plugin.
489 * @param target peer that disconnected
492 send_disconnect_to_plugin (const struct GNUNET_PeerIdentity *target)
494 struct GNUNET_DV_DisconnectMessage dm;
496 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
497 "Delivering DISCONNECT about peer `%s'\n",
498 GNUNET_i2s (target));
499 dm.header.size = htons (sizeof (dm));
500 dm.header.type = htons (GNUNET_MESSAGE_TYPE_DV_DISCONNECT);
501 dm.reserved = htonl (0);
503 send_control_to_plugin (&dm.header);
508 * Function called to transfer a message to another peer
511 * @param cls closure with the direct neighbor
512 * @param size number of bytes available in buf
513 * @param buf where the callee should write the message
514 * @return number of bytes written to buf
517 core_transmit_notify (void *cls, size_t size, void *buf)
519 struct DirectNeighbor *dn = cls;
521 struct PendingMessage *pending;
528 /* peer disconnected */
532 pending = dn->pm_head;
534 while ( (NULL != (pending = dn->pm_head)) &&
535 (size >= off + (msize = ntohs (pending->msg->size))))
538 GNUNET_CONTAINER_DLL_remove (dn->pm_head,
541 memcpy (&cbuf[off], pending->msg, msize);
542 if (0 != pending->uid)
543 send_ack_to_plugin (&pending->ultimate_target,
546 GNUNET_free (pending);
549 if (NULL != dn->pm_head)
551 GNUNET_CORE_notify_transmit_ready (core_api,
552 GNUNET_YES /* cork */,
554 GNUNET_TIME_UNIT_FOREVER_REL,
557 &core_transmit_notify, dn);
563 * Forward the given payload to the given target.
565 * @param target where to send the message
566 * @param uid unique ID for the message
567 * @param ultimate_target ultimate recipient for the message
568 * @param distance expected (remaining) distance to the target
569 * @param sender original sender of the message
570 * @param payload payload of the message
573 forward_payload (struct DirectNeighbor *target,
576 const struct GNUNET_PeerIdentity *sender,
577 const struct GNUNET_PeerIdentity *ultimate_target,
578 const struct GNUNET_MessageHeader *payload)
580 struct PendingMessage *pm;
581 struct RouteMessage *rm;
584 if ( (target->pm_queue_size >= MAX_QUEUE_SIZE) &&
585 (0 != memcmp (sender,
587 sizeof (struct GNUNET_PeerIdentity))) )
589 GNUNET_break (0 == uid);
592 msize = sizeof (struct RouteMessage) + ntohs (payload->size);
593 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
598 pm = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
599 pm->ultimate_target = *ultimate_target;
601 pm->msg = (const struct GNUNET_MessageHeader *) &pm[1];
602 rm = (struct RouteMessage *) &pm[1];
603 rm->header.size = htons ((uint16_t) msize);
604 rm->header.type = htons (GNUNET_MESSAGE_TYPE_DV_ROUTE);
605 rm->distance = htonl (distance);
606 rm->target = target->peer;
607 rm->sender = *sender;
608 memcpy (&rm[1], payload, ntohs (payload->size));
609 GNUNET_CONTAINER_DLL_insert_tail (target->pm_head,
612 target->pm_queue_size++;
613 if (NULL == target->cth)
614 target->cth = GNUNET_CORE_notify_transmit_ready (core_api,
615 GNUNET_YES /* cork */,
617 GNUNET_TIME_UNIT_FOREVER_REL,
620 &core_transmit_notify, target);
625 * Find a free slot for storing a 'route' in the 'consensi'
626 * set at the given distance.
628 * @param distance distance to use for the set slot
631 get_consensus_slot (uint32_t distance)
633 struct ConsensusSet *cs;
636 cs = &consensi[distance];
638 while ( (i < cs->array_length) &&
639 (NULL != cs->targets[i]) ) i++;
640 if (i == cs->array_length)
641 GNUNET_array_grow (cs->targets,
643 cs->array_length * 2 + 2);
649 * Allocate a slot in the consensus set for a route.
651 * @param route route to initialize
652 * @param distance which consensus set to use
655 allocate_route (struct Route *route,
660 i = get_consensus_slot (distance);
661 route->set_offset = i;
662 consensi[distance].targets[i] = route;
663 route->target.distance = htonl (distance);
668 * Release a slot in the consensus set for a route.
670 * @param route route to release the slot from
673 release_route (struct Route *route)
675 consensi[ntohl (route->target.distance)].targets[route->set_offset] = NULL;
676 route->set_offset = UINT_MAX; /* indicate invalid slot */
681 * Move a route from one consensus set to another.
683 * @param route route to move
684 * @param new_distance new distance for the route (destination set)
687 move_route (struct Route *route,
688 uint32_t new_distance)
692 release_route (route);
693 i = get_consensus_slot (new_distance);
694 route->set_offset = i;
695 consensi[new_distance].targets[i] = route;
696 route->target.distance = htonl (new_distance);
701 * Start creating a new consensus from scratch.
703 * @param cls the 'struct DirectNeighbor' of the peer we're building
704 * a routing consensus with
705 * @param tc scheduler context
708 start_consensus (void *cls,
709 const struct GNUNET_SCHEDULER_TaskContext *tc);
713 * Method called whenever a peer connects.
716 * @param peer peer identity this notification is about
717 * @param atsi performance data
718 * @param atsi_count number of entries in atsi
721 handle_core_connect (void *cls, const struct GNUNET_PeerIdentity *peer,
722 const struct GNUNET_ATS_Information *atsi,
723 unsigned int atsi_count)
725 struct DirectNeighbor *neighbor;
729 /* Check for connect to self message */
730 if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
732 distance = get_atsi_distance (atsi, atsi_count);
733 neighbor = GNUNET_CONTAINER_multihashmap_get (direct_neighbors,
735 if (NULL != neighbor)
740 if (DIRECT_NEIGHBOR_COST != distance)
741 return; /* is a DV-neighbor */
742 GNUNET_STATISTICS_update (stats,
743 "# peers connected (1-hop)",
745 neighbor = GNUNET_malloc (sizeof (struct DirectNeighbor));
746 neighbor->peer = *peer;
747 GNUNET_assert (GNUNET_YES ==
748 GNUNET_CONTAINER_multihashmap_put (direct_neighbors,
751 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
752 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
756 send_disconnect_to_plugin (peer);
757 release_route (route);
760 neighbor->consensus_task = GNUNET_SCHEDULER_add_now (&start_consensus,
766 * Called for each 'target' in a neighbor table to free the associated memory.
769 * @param key key of the value
770 * @param value value to free
771 * @return GNUNET_OK to continue to iterate
774 free_targets (void *cls,
775 const struct GNUNET_HashCode *key,
784 * Multihashmap iterator for checking if a given route is
785 * (now) useful to this peer.
787 * @param cls the direct neighbor for the given route
788 * @param key key value stored under
789 * @param value a 'struct Target' that may or may not be useful; not that
790 * the distance in 'target' does not include the first hop yet
791 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
794 check_possible_route (void *cls, const struct GNUNET_HashCode * key, void *value)
796 struct DirectNeighbor *neighbor = cls;
797 struct Target *target = value;
800 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
804 if (ntohl (route->target.distance) > ntohl (target->distance) + 1)
806 /* this 'target' is cheaper than the existing route; switch to alternative route! */
807 move_route (route, ntohl (target->distance) + 1);
808 route->next_hop = neighbor;
809 send_distance_change_to_plugin (&target->peer, ntohl (target->distance) + 1);
811 return GNUNET_YES; /* got a route to this target already */
813 route = GNUNET_malloc (sizeof (struct Route));
814 route->next_hop = neighbor;
815 route->target.distance = htonl (ntohl (target->distance) + 1);
816 route->target.peer = target->peer;
817 allocate_route (route, ntohl (route->target.distance));
818 GNUNET_assert (GNUNET_YES ==
819 GNUNET_CONTAINER_multihashmap_put (all_routes,
820 &route->target.peer.hashPubKey,
822 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
823 send_connect_to_plugin (&route->target.peer, ntohl (target->distance));
829 * Multihashmap iterator for finding routes that were previously
830 * "hidden" due to a better route (called after a disconnect event).
833 * @param key peer identity of the given direct neighbor
834 * @param value a 'struct DirectNeighbor' to check for additional routes
835 * @return GNUNET_YES to continue iteration
838 refresh_routes (void *cls, const struct GNUNET_HashCode * key, void *value)
840 struct DirectNeighbor *neighbor = value;
842 if (NULL != neighbor->neighbor_table)
843 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table,
844 &check_possible_route,
851 * Check if a target was removed from the set of the other peer; if so,
852 * if we also used it for our route, we need to remove it from our
853 * 'all_routes' set (and later check if an alternative path now exists).
855 * @param cls the 'struct DirectNeighbor'
856 * @param key peer identity for the target
857 * @param value a 'struct Target' previously reachable via the given neighbor
860 check_target_removed (void *cls,
861 const struct GNUNET_HashCode *key,
864 struct DirectNeighbor *neighbor = cls;
865 struct Target *new_target;
866 struct Route *current_route;
868 new_target = GNUNET_CONTAINER_multihashmap_get (neighbor->neighbor_table_consensus,
870 if (NULL == new_target)
872 /* target was revoked, check if it was used */
873 current_route = GNUNET_CONTAINER_multihashmap_get (all_routes,
875 if ( (NULL == current_route) ||
876 (current_route->next_hop != neighbor) )
878 /* didn't matter, wasn't used */
881 /* remove existing route */
882 GNUNET_assert (GNUNET_YES ==
883 GNUNET_CONTAINER_multihashmap_remove (all_routes, key, current_route));
884 send_disconnect_to_plugin (¤t_route->target.peer);
885 GNUNET_free (current_route);
886 neighbor->target_removed = GNUNET_YES;
894 * Check if a target was added to the set of the other peer; if it
895 * was added or impoves the existing route, do the needed updates.
897 * @param cls the 'struct DirectNeighbor'
898 * @param key peer identity for the target
899 * @param value a 'struct Target' now reachable via the given neighbor
902 check_target_added (void *cls,
903 const struct GNUNET_HashCode *key,
906 struct DirectNeighbor *neighbor = cls;
907 struct Target *target = value;
908 struct Route *current_route;
910 /* target was revoked, check if it was used */
911 current_route = GNUNET_CONTAINER_multihashmap_get (all_routes,
913 if (NULL != current_route)
916 if (current_route->next_hop == neighbor)
918 /* we had the same route before, no change */
919 if (ntohl (target->distance) + 1 != ntohl (current_route->target.distance))
921 current_route->target.distance = htonl (ntohl (target->distance) + 1);
922 send_distance_change_to_plugin (&target->peer, ntohl (target->distance) + 1);
926 if (ntohl (current_route->target.distance) >= ntohl (target->distance) + 1)
928 /* alternative, shorter route exists, ignore */
931 /* new route is better than the existing one, take over! */
932 /* NOTE: minor security issue: malicious peers may advertise
933 very short routes to take over longer paths; as we don't
934 check that the shorter routes actually work, a malicious
935 direct neighbor can use this to DoS our long routes */
936 current_route->next_hop = neighbor;
937 current_route->target.distance = htonl (ntohl (target->distance) + 1);
938 send_distance_change_to_plugin (&target->peer, ntohl (target->distance) + 1);
942 current_route = GNUNET_malloc (sizeof (struct Route));
943 current_route->next_hop = neighbor;
944 current_route->target.peer = target->peer;
945 current_route->target.distance = htonl (ntohl (target->distance) + 1);
946 GNUNET_assert (GNUNET_YES ==
947 GNUNET_CONTAINER_multihashmap_put (all_routes,
948 ¤t_route->target.peer.hashPubKey,
950 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
951 send_connect_to_plugin (¤t_route->target.peer,
952 ntohl (current_route->target.distance));
959 * The consensus has concluded, clean up and schedule the next one.
961 * @param cls the 'struct GNUNET_DirectNeighbor' with which we created the consensus
965 consensus_done_cb (void *cls,
966 const struct GNUNET_CONSENSUS_Group *group)
968 struct DirectNeighbor *neighbor = cls;
970 GNUNET_CONSENSUS_destroy (neighbor->consensus);
971 neighbor->consensus = NULL;
972 /* remove targets that disappeared */
973 neighbor->target_removed = GNUNET_NO;
974 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table,
975 &check_target_removed,
977 if (GNUNET_YES == neighbor->target_removed)
979 /* check if we got an alternative for the removed routes */
980 GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
984 /* add targets that appeared (and check for improved routes) */
985 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table_consensus,
988 if (NULL != neighbor->neighbor_table)
990 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table,
993 GNUNET_CONTAINER_multihashmap_destroy (neighbor->neighbor_table);
994 neighbor->neighbor_table = NULL;
996 neighbor->neighbor_table = neighbor->neighbor_table_consensus;
997 neighbor->neighbor_table_consensus = NULL;
998 neighbor->consensus_task = GNUNET_SCHEDULER_add_delayed (GNUNET_DV_CONSENSUS_FREQUENCY,
1005 * We inserted the last element into the consensus, get ready to
1006 * insert the next element into the consensus or conclude if
1009 * @param cls the 'struct DirectNeighbor' of the peer we're building
1010 * a routing consensus with
1011 * @param success GNUNET_OK if the last element was added successfully,
1012 * GNUNET_SYSERR if we failed
1015 insert_next_element (void *cls,
1018 struct DirectNeighbor *neighbor = cls;
1019 struct GNUNET_CONSENSUS_Element element;
1021 while ( (DEFAULT_FISHEYE_DEPTH - 1 > neighbor->consensus_insertion_distance) &&
1022 (consensi[neighbor->consensus_insertion_distance].array_length == neighbor->consensus_insertion_offset) )
1024 neighbor->consensus_insertion_offset = 0;
1025 neighbor->consensus_insertion_distance++;
1026 /* skip over NULL entries */
1027 while ( (DEFAULT_FISHEYE_DEPTH - 1 > neighbor->consensus_insertion_distance) &&
1028 (consensi[neighbor->consensus_insertion_distance].array_length < neighbor->consensus_insertion_offset) &&
1029 (NULL == consensi[neighbor->consensus_insertion_distance].targets[neighbor->consensus_insertion_offset]) )
1030 neighbor->consensus_insertion_offset++;
1032 if (DEFAULT_FISHEYE_DEPTH - 1 == neighbor->consensus_insertion_distance)
1034 /* we're done, conclude! */
1035 GNUNET_CONSENSUS_conclude (neighbor->consensus,
1036 GNUNET_DV_CONSENSUS_FREQUENCY,
1042 element.size = sizeof (struct Target);
1043 element.data = &consensi[neighbor->consensus_insertion_distance].targets[neighbor->consensus_insertion_offset++]->target;
1045 /* skip over NULL entries */
1046 while ( (DEFAULT_FISHEYE_DEPTH - 1 > neighbor->consensus_insertion_distance) &&
1047 (consensi[neighbor->consensus_insertion_distance].array_length < neighbor->consensus_insertion_offset) &&
1048 (NULL == consensi[neighbor->consensus_insertion_distance].targets[neighbor->consensus_insertion_offset]) )
1049 neighbor->consensus_insertion_offset++;
1050 GNUNET_CONSENSUS_insert (neighbor->consensus,
1052 &insert_next_element,
1058 * We have learned a new route from the other peer. Add it to the
1059 * route set we're building.
1061 * @param cls the 'struct DirectNeighbor' we're building the consensus with
1062 * @param element the new element we have learned
1063 * @return GNUNET_OK if the valid is well-formed and should be added to the consensus,
1064 * GNUNET_SYSERR if the element should be ignored and not be propagated
1067 learn_route_cb (void *cls,
1068 const struct GNUNET_CONSENSUS_Element *element)
1070 struct DirectNeighbor *neighbor = cls;
1071 struct Target *target;
1073 if (NULL == element)
1075 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1076 "Failed to establish DV consensus, will try again later\n");
1077 GNUNET_CONSENSUS_destroy (neighbor->consensus);
1078 if (NULL != neighbor->neighbor_table_consensus)
1080 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table_consensus,
1083 GNUNET_CONTAINER_multihashmap_destroy (neighbor->neighbor_table_consensus);
1084 neighbor->neighbor_table_consensus = NULL;
1086 neighbor->consensus = NULL;
1087 neighbor->consensus_task = GNUNET_SCHEDULER_add_delayed (GNUNET_DV_CONSENSUS_FREQUENCY,
1090 return GNUNET_SYSERR;
1092 if (sizeof (struct Target) != element->size)
1094 GNUNET_break_op (0);
1095 return GNUNET_SYSERR;
1097 target = GNUNET_malloc (sizeof (struct Target));
1098 memcpy (target, element->data, sizeof (struct Target));
1100 GNUNET_CONTAINER_multihashmap_put (neighbor->neighbor_table_consensus,
1101 &target->peer.hashPubKey,
1103 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
1105 GNUNET_break_op (0);
1106 GNUNET_free (target);
1107 return GNUNET_SYSERR;
1114 * Start creating a new consensus from scratch.
1116 * @param cls the 'struct DirectNeighbor' of the peer we're building
1117 * a routing consensus with
1118 * @param tc scheduler context
1121 start_consensus (void *cls,
1122 const struct GNUNET_SCHEDULER_TaskContext *tc)
1124 struct DirectNeighbor *neighbor = cls;
1125 struct GNUNET_HashCode session_id;
1126 struct GNUNET_HashCode real_session_id;
1128 neighbor->consensus_task = GNUNET_SCHEDULER_NO_TASK;
1129 neighbor->consensus_insertion_offset = 0;
1130 neighbor->consensus_insertion_distance = 0;
1131 GNUNET_assert (NULL == neighbor->neighbor_table_consensus);
1132 GNUNET_assert (NULL == neighbor->consensus);
1133 neighbor->neighbor_table_consensus = GNUNET_CONTAINER_multihashmap_create (1024, GNUNET_YES);
1134 /* construct session ID seed as XOR of both peer's identities */
1135 GNUNET_CRYPTO_hash_xor (&my_identity.hashPubKey,
1136 &neighbor->peer.hashPubKey,
1138 /* make sure session ID is unique across applications by salting it with 'DV' */
1139 GNUNET_CRYPTO_hkdf (&real_session_id, sizeof (real_session_id),
1140 GCRY_MD_SHA512, GCRY_MD_SHA256,
1142 &session_id, sizeof (session_id),
1144 neighbor->consensus = GNUNET_CONSENSUS_create (cfg,
1150 if (NULL == neighbor->consensus)
1152 neighbor->consensus_task = GNUNET_SCHEDULER_add_delayed (GNUNET_DV_CONSENSUS_FREQUENCY,
1157 insert_next_element (neighbor, GNUNET_OK);
1162 * Core handler for DV data messages. Whatever this message
1163 * contains all we really have to do is rip it out of its
1164 * DV layering and give it to our pal the DV plugin to report
1167 * @param cls closure
1168 * @param peer peer which sent the message (immediate sender)
1169 * @param message the message
1170 * @param atsi transport ATS information (latency, distance, etc.)
1171 * @param atsi_count number of entries in atsi
1172 * @return GNUNET_OK on success, GNUNET_SYSERR if the other peer violated the protocol
1175 handle_dv_route_message (void *cls, const struct GNUNET_PeerIdentity *peer,
1176 const struct GNUNET_MessageHeader *message,
1177 const struct GNUNET_ATS_Information *atsi,
1178 unsigned int atsi_count)
1180 const struct RouteMessage *rm;
1181 const struct GNUNET_MessageHeader *payload;
1182 struct Route *route;
1184 if (ntohs (message->size) < sizeof (struct RouteMessage) + sizeof (struct GNUNET_MessageHeader))
1186 GNUNET_break_op (0);
1187 return GNUNET_SYSERR;
1189 rm = (const struct RouteMessage *) message;
1190 payload = (const struct GNUNET_MessageHeader *) &rm[1];
1191 if (ntohs (message->size) != sizeof (struct RouteMessage) + ntohs (payload->size))
1193 GNUNET_break_op (0);
1194 return GNUNET_SYSERR;
1196 if (0 == memcmp (&rm->target,
1198 sizeof (struct GNUNET_PeerIdentity)))
1200 /* message is for me, check reverse route! */
1201 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
1202 &rm->sender.hashPubKey);
1205 /* don't have reverse route, drop */
1206 GNUNET_STATISTICS_update (stats,
1207 "# message discarded (no reverse route)",
1211 send_data_to_plugin (payload,
1213 ntohl (route->target.distance));
1216 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
1217 &rm->target.hashPubKey);
1220 GNUNET_STATISTICS_update (stats,
1221 "# messages discarded (no route)",
1225 if (ntohl (route->target.distance) > ntohl (rm->distance) + 1)
1227 GNUNET_STATISTICS_update (stats,
1228 "# messages discarded (target too far)",
1232 forward_payload (route->next_hop,
1233 ntohl (route->target.distance),
1243 * Service server's handler for message send requests (which come
1244 * bubbling up to us through the DV plugin).
1246 * @param cls closure
1247 * @param client identification of the client
1248 * @param message the actual message
1251 handle_dv_send_message (void *cls, struct GNUNET_SERVER_Client *client,
1252 const struct GNUNET_MessageHeader *message)
1254 struct Route *route;
1255 const struct GNUNET_DV_SendMessage *msg;
1256 const struct GNUNET_MessageHeader *payload;
1258 if (ntohs (message->size) < sizeof (struct GNUNET_DV_SendMessage) + sizeof (struct GNUNET_MessageHeader))
1261 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1264 msg = (const struct GNUNET_DV_SendMessage *) message;
1265 GNUNET_break (0 != ntohl (msg->uid));
1266 payload = (const struct GNUNET_MessageHeader *) &msg[1];
1267 if (ntohs (message->size) != sizeof (struct GNUNET_DV_SendMessage) + ntohs (payload->size))
1270 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1273 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
1274 &msg->target.hashPubKey);
1277 /* got disconnected */
1278 GNUNET_STATISTICS_update (stats,
1279 "# local messages discarded (no route)",
1281 send_ack_to_plugin (&msg->target, ntohl (msg->uid), GNUNET_YES);
1282 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1285 forward_payload (route->next_hop,
1286 ntohl (route->target.distance),
1291 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1296 * Multihashmap iterator for freeing routes that go via a particular
1297 * neighbor that disconnected and is thus no longer available.
1299 * @param cls the direct neighbor that is now unavailable
1300 * @param key key value stored under
1301 * @param value a 'struct Route' that may or may not go via neighbor
1303 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
1306 cull_routes (void *cls, const struct GNUNET_HashCode * key, void *value)
1308 struct DirectNeighbor *neighbor = cls;
1309 struct Route *route = value;
1311 if (route->next_hop != neighbor)
1312 return GNUNET_YES; /* not affected */
1313 GNUNET_assert (GNUNET_YES ==
1314 GNUNET_CONTAINER_multihashmap_remove (all_routes, key, value));
1315 release_route (route);
1316 send_disconnect_to_plugin (&route->target.peer);
1317 GNUNET_free (route);
1323 * Cleanup all of the data structures associated with a given neighbor.
1325 * @param neighbor neighbor to clean up
1328 cleanup_neighbor (struct DirectNeighbor *neighbor)
1330 struct PendingMessage *pending;
1332 while (NULL != (pending = neighbor->pm_head))
1334 neighbor->pm_queue_size--;
1335 GNUNET_CONTAINER_DLL_remove (neighbor->pm_head,
1338 GNUNET_free (pending);
1340 GNUNET_CONTAINER_multihashmap_iterate (all_routes,
1343 if (NULL != neighbor->cth)
1345 GNUNET_CORE_notify_transmit_ready_cancel (neighbor->cth);
1346 neighbor->cth = NULL;
1348 if (NULL != neighbor->neighbor_table_consensus)
1350 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table_consensus,
1353 GNUNET_CONTAINER_multihashmap_destroy (neighbor->neighbor_table_consensus);
1354 neighbor->neighbor_table_consensus = NULL;
1356 if (NULL != neighbor->neighbor_table)
1358 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table,
1361 GNUNET_CONTAINER_multihashmap_destroy (neighbor->neighbor_table);
1362 neighbor->neighbor_table = NULL;
1364 if (GNUNET_SCHEDULER_NO_TASK != neighbor->consensus_task)
1366 GNUNET_SCHEDULER_cancel (neighbor->consensus_task);
1367 neighbor->consensus_task = GNUNET_SCHEDULER_NO_TASK;
1369 if (NULL != neighbor->consensus)
1371 GNUNET_CONSENSUS_destroy (neighbor->consensus);
1372 neighbor->consensus = NULL;
1374 GNUNET_assert (GNUNET_YES ==
1375 GNUNET_CONTAINER_multihashmap_remove (direct_neighbors,
1376 &neighbor->peer.hashPubKey,
1378 GNUNET_free (neighbor);
1383 * Method called whenever a given peer disconnects.
1385 * @param cls closure
1386 * @param peer peer identity this notification is about
1389 handle_core_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer)
1391 struct DirectNeighbor *neighbor;
1393 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1394 "Received core peer disconnect message for peer `%s'!\n",
1396 /* Check for disconnect from self message */
1397 if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
1400 GNUNET_CONTAINER_multihashmap_get (direct_neighbors, &peer->hashPubKey);
1401 if (NULL == neighbor)
1403 /* must have been a DV-neighbor, ignore */
1406 GNUNET_STATISTICS_update (stats,
1407 "# peers connected (1-hop)",
1409 cleanup_neighbor (neighbor);
1410 GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
1417 * Multihashmap iterator for freeing routes. Should never be called.
1420 * @param key key value stored under
1421 * @param value the route to be freed
1423 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
1426 free_route (void *cls, const struct GNUNET_HashCode * key, void *value)
1428 struct Route *route = value;
1431 GNUNET_assert (GNUNET_YES ==
1432 GNUNET_CONTAINER_multihashmap_remove (all_routes, key, value));
1433 release_route (route);
1434 send_disconnect_to_plugin (&route->target.peer);
1435 GNUNET_free (route);
1441 * Multihashmap iterator for freeing direct neighbors. Should never be called.
1444 * @param key key value stored under
1445 * @param value the direct neighbor to be freed
1447 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
1450 free_direct_neighbors (void *cls, const struct GNUNET_HashCode * key, void *value)
1452 struct DirectNeighbor *neighbor = value;
1455 cleanup_neighbor (neighbor);
1461 * Task run during shutdown.
1467 shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1471 GNUNET_CORE_disconnect (core_api);
1473 GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
1474 &free_direct_neighbors, NULL);
1475 GNUNET_CONTAINER_multihashmap_iterate (all_routes,
1477 GNUNET_CONTAINER_multihashmap_destroy (direct_neighbors);
1478 GNUNET_CONTAINER_multihashmap_destroy (all_routes);
1479 GNUNET_STATISTICS_destroy (stats, GNUNET_NO);
1481 GNUNET_SERVER_notification_context_destroy (nc);
1483 for (i=0;i<DEFAULT_FISHEYE_DEPTH - 1;i++)
1484 GNUNET_array_grow (consensi[i].targets,
1485 consensi[i].array_length,
1491 * Notify newly connected client about an existing route.
1493 * @param cls the 'struct GNUNET_SERVER_Client'
1494 * @param key peer identity
1495 * @param value the XXX.
1496 * @return GNUNET_OK (continue to iterate)
1499 add_route (void *cls,
1500 const struct GNUNET_HashCode *key,
1503 struct GNUNET_SERVER_Client *client = cls;
1504 struct Route *route = value;
1505 struct GNUNET_DV_ConnectMessage cm;
1507 cm.header.size = htons (sizeof (cm));
1508 cm.header.type = htons (GNUNET_MESSAGE_TYPE_DV_CONNECT);
1509 cm.distance = htonl (route->target.distance);
1510 cm.peer = route->target.peer;
1512 GNUNET_SERVER_notification_context_unicast (nc,
1521 * Handle START-message. This is the first message sent to us
1522 * by the client (can only be one!).
1524 * @param cls closure (always NULL)
1525 * @param client identification of the client
1526 * @param message the actual message
1529 handle_start (void *cls, struct GNUNET_SERVER_Client *client,
1530 const struct GNUNET_MessageHeader *message)
1532 GNUNET_SERVER_notification_context_add (nc, client);
1533 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1534 GNUNET_CONTAINER_multihashmap_iterate (all_routes,
1541 * Called on core init.
1544 * @param server legacy
1545 * @param identity this peer's identity
1548 core_init (void *cls, struct GNUNET_CORE_Handle *server,
1549 const struct GNUNET_PeerIdentity *identity)
1551 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1553 GNUNET_i2s (identity));
1554 my_identity = *identity;
1559 * Process dv requests.
1561 * @param cls closure
1562 * @param server the initialized server
1563 * @param c configuration to use
1566 run (void *cls, struct GNUNET_SERVER_Handle *server,
1567 const struct GNUNET_CONFIGURATION_Handle *c)
1569 static struct GNUNET_CORE_MessageHandler core_handlers[] = {
1570 {&handle_dv_route_message, GNUNET_MESSAGE_TYPE_DV_ROUTE, 0},
1573 static struct GNUNET_SERVER_MessageHandler plugin_handlers[] = {
1574 {&handle_start, NULL,
1575 GNUNET_MESSAGE_TYPE_DV_START,
1576 sizeof (struct GNUNET_MessageHeader) },
1577 { &handle_dv_send_message, NULL,
1578 GNUNET_MESSAGE_TYPE_DV_SEND,
1584 direct_neighbors = GNUNET_CONTAINER_multihashmap_create (128, GNUNET_NO);
1585 all_routes = GNUNET_CONTAINER_multihashmap_create (65536, GNUNET_NO);
1586 core_api = GNUNET_CORE_connect (cfg, NULL,
1588 &handle_core_connect,
1589 &handle_core_disconnect,
1594 if (NULL == core_api)
1596 nc = GNUNET_SERVER_notification_context_create (server,
1597 MAX_QUEUE_SIZE_PLUGIN);
1598 stats = GNUNET_STATISTICS_create ("dv", cfg);
1599 GNUNET_SERVER_add_handlers (server, plugin_handlers);
1600 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
1601 &shutdown_task, NULL);
1606 * The main function for the dv service.
1608 * @param argc number of arguments from the command line
1609 * @param argv command line arguments
1610 * @return 0 ok, 1 on error
1613 main (int argc, char *const *argv)
1615 return (GNUNET_OK ==
1616 GNUNET_SERVICE_run (argc, argv, "dv", GNUNET_SERVICE_OPTION_NONE,
1617 &run, NULL)) ? 0 : 1;
1620 /* end of gnunet-service-dv.c */