2 This file is part of GNUnet.
3 (C) 2013 Christian Grothoff (and other contributing authors)
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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 * - even _local_ flow control (send ACK only after core took our message) is
32 * not implemented, but should be (easy fix, but needs adjustments to data
34 * - distance updates are not properly communicate to US by core,
35 * and conversely we don't give distance updates properly to the plugin yet
36 * - we send 'ACK' even if a message was dropped due to no route (may
37 * be harmless, but should at least be documented)
40 #include "gnunet_util_lib.h"
41 #include "gnunet_protocols.h"
42 #include "gnunet_core_service.h"
43 #include "gnunet_hello_lib.h"
44 #include "gnunet_peerinfo_service.h"
45 #include "gnunet_statistics_service.h"
46 #include "gnunet_consensus_service.h"
51 * How often do we establish the consensu?
53 #define GNUNET_DV_CONSENSUS_FREQUENCY GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 5)
56 * Maximum number of messages we queue per peer.
58 #define MAX_QUEUE_SIZE 16
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. Hopefully
327 * this client will never change, although if the plugin dies
328 * and returns for some reason it may happen.
330 static struct GNUNET_SERVER_Client *client_handle;
333 * Transmit handle to the plugin.
335 static struct GNUNET_SERVER_TransmitHandle *plugin_transmit_handle;
338 * Head of DLL for client messages
340 static struct PendingMessage *plugin_pending_head;
343 * Tail of DLL for client messages
345 static struct PendingMessage *plugin_pending_tail;
348 * Handle for the statistics service.
350 struct GNUNET_STATISTICS_Handle *stats;
354 * Get distance information from 'atsi'.
356 * @param atsi performance data
357 * @param atsi_count number of entries in atsi
358 * @return connected transport distance
361 get_atsi_distance (const struct GNUNET_ATS_Information *atsi,
362 unsigned int atsi_count)
366 for (i = 0; i < atsi_count; i++)
367 if (ntohl (atsi[i].type) == GNUNET_ATS_QUALITY_NET_DISTANCE)
368 return ntohl (atsi->value);
369 /* FIXME: we do not have distance data? Assume direct neighbor. */
370 return DIRECT_NEIGHBOR_COST;
375 * Function called to notify a client about the socket
376 * begin ready to queue more data. "buf" will be
377 * NULL and "size" zero if the socket was closed for
378 * writing in the meantime.
381 * @param size number of bytes available in buf
382 * @param buf where the callee should write the message
383 * @return number of bytes written to buf
386 transmit_to_plugin (void *cls, size_t size, void *buf)
389 struct PendingMessage *reply;
393 plugin_transmit_handle = NULL;
396 /* client disconnected */
400 while ( (NULL != (reply = plugin_pending_head)) &&
401 (size >= off + (msize = ntohs (reply->msg->size))))
403 GNUNET_CONTAINER_DLL_remove (plugin_pending_head, plugin_pending_tail,
405 memcpy (&cbuf[off], reply->msg, msize);
409 if (NULL != plugin_pending_head)
410 plugin_transmit_handle =
411 GNUNET_SERVER_notify_transmit_ready (client_handle,
413 GNUNET_TIME_UNIT_FOREVER_REL,
414 &transmit_to_plugin, NULL);
420 * Forward a message from another peer to the plugin.
422 * @param message the message to send to the plugin
423 * @param distant_neighbor the original sender of the message
424 * @param distnace distance to the original sender of the message
427 send_data_to_plugin (const struct GNUNET_MessageHeader *message,
428 const struct GNUNET_PeerIdentity *distant_neighbor,
431 struct GNUNET_DV_ReceivedMessage *received_msg;
432 struct PendingMessage *pending_message;
435 if (NULL == client_handle)
437 GNUNET_STATISTICS_update (stats,
438 "# messages discarded (no plugin)",
440 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
441 _("Refusing to queue messages, DV plugin not active.\n"));
444 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
445 "Delivering message from peer `%s'\n",
446 GNUNET_i2s (distant_neighbor));
447 size = sizeof (struct GNUNET_DV_ReceivedMessage) +
448 ntohs (message->size);
449 if (size >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
451 GNUNET_break (0); /* too big */
454 pending_message = GNUNET_malloc (sizeof (struct PendingMessage) + size);
455 received_msg = (struct GNUNET_DV_ReceivedMessage *) &pending_message[1];
456 received_msg->header.size = htons (size);
457 received_msg->header.type = htons (GNUNET_MESSAGE_TYPE_DV_RECV);
458 received_msg->distance = htonl (distance);
459 received_msg->sender = *distant_neighbor;
460 memcpy (&received_msg[1], message, ntohs (message->size));
461 GNUNET_CONTAINER_DLL_insert_tail (plugin_pending_head,
464 if (NULL == plugin_transmit_handle)
465 plugin_transmit_handle =
466 GNUNET_SERVER_notify_transmit_ready (client_handle, size,
467 GNUNET_TIME_UNIT_FOREVER_REL,
468 &transmit_to_plugin, NULL);
473 * Forward a control message to the plugin.
475 * @param message the message to send to the plugin
476 * @param distant_neighbor the original sender of the message
477 * @param distnace distance to the original sender of the message
480 send_control_to_plugin (const struct GNUNET_MessageHeader *message)
482 struct PendingMessage *pending_message;
485 if (NULL == client_handle)
487 GNUNET_STATISTICS_update (stats,
488 "# control messages discarded (no plugin)",
490 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
491 _("Refusing to queue messages, DV plugin not active.\n"));
494 size = ntohs (message->size);
495 pending_message = GNUNET_malloc (sizeof (struct PendingMessage) + size);
496 memcpy (&pending_message[1], message, size);
497 GNUNET_CONTAINER_DLL_insert_tail (plugin_pending_head,
500 if (NULL == plugin_transmit_handle)
501 plugin_transmit_handle =
502 GNUNET_SERVER_notify_transmit_ready (client_handle, size,
503 GNUNET_TIME_UNIT_FOREVER_REL,
504 &transmit_to_plugin, NULL);
509 * Give an ACK message to the plugin, we transmitted a message for it.
511 * @param target peer that received the message
512 * @param uid plugin-chosen UID for the message
515 send_ack_to_plugin (const struct GNUNET_PeerIdentity *target,
518 struct GNUNET_DV_AckMessage ack_msg;
520 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
521 "Delivering ACK for message to peer `%s'\n",
522 GNUNET_i2s (target));
523 ack_msg.header.size = htons (sizeof (ack_msg));
524 ack_msg.header.type = htons (GNUNET_MESSAGE_TYPE_DV_SEND_ACK);
525 ack_msg.uid = htonl (uid);
526 ack_msg.target = *target;
527 send_control_to_plugin (&ack_msg.header);
532 * Give a CONNECT message to the plugin.
534 * @param target peer that connected
535 * @param distance distance to the target
538 send_connect_to_plugin (const struct GNUNET_PeerIdentity *target,
541 struct GNUNET_DV_ConnectMessage cm;
543 if (NULL == client_handle)
545 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
546 "Delivering CONNECT about peer `%s'\n",
547 GNUNET_i2s (target));
548 cm.header.size = htons (sizeof (cm));
549 cm.header.type = htons (GNUNET_MESSAGE_TYPE_DV_CONNECT);
550 cm.distance = htonl (distance);
552 send_control_to_plugin (&cm.header);
557 * Give a DISCONNECT message to the plugin.
559 * @param target peer that disconnected
562 send_disconnect_to_plugin (const struct GNUNET_PeerIdentity *target)
564 struct GNUNET_DV_DisconnectMessage dm;
566 if (NULL == client_handle)
568 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
569 "Delivering DISCONNECT about peer `%s'\n",
570 GNUNET_i2s (target));
571 dm.header.size = htons (sizeof (dm));
572 dm.header.type = htons (GNUNET_MESSAGE_TYPE_DV_DISCONNECT);
573 dm.reserved = htonl (0);
575 send_control_to_plugin (&dm.header);
580 * Function called to transfer a message to another peer
583 * @param cls closure with the direct neighbor
584 * @param size number of bytes available in buf
585 * @param buf where the callee should write the message
586 * @return number of bytes written to buf
589 core_transmit_notify (void *cls, size_t size, void *buf)
591 struct DirectNeighbor *dn = cls;
593 struct PendingMessage *pending;
600 /* peer disconnected */
604 pending = dn->pm_head;
606 while ( (NULL != (pending = dn->pm_head)) &&
607 (size >= off + (msize = ntohs (pending->msg->size))))
610 GNUNET_CONTAINER_DLL_remove (dn->pm_head,
613 memcpy (&cbuf[off], pending->msg, msize);
614 send_ack_to_plugin (&pending->ultimate_target,
616 GNUNET_free (pending);
619 if (NULL != dn->pm_head)
621 GNUNET_CORE_notify_transmit_ready (core_api,
622 GNUNET_YES /* cork */,
624 GNUNET_TIME_UNIT_FOREVER_REL,
627 &core_transmit_notify, dn);
633 * Forward the given payload to the given target.
635 * @param target where to send the message
636 * @param distance expected (remaining) distance to the target
637 * @param sender original sender of the message
638 * @param payload payload of the message
641 forward_payload (struct DirectNeighbor *target,
643 const struct GNUNET_PeerIdentity *sender,
644 const struct GNUNET_MessageHeader *payload)
646 struct PendingMessage *pm;
647 struct RouteMessage *rm;
650 if ( (target->pm_queue_size >= MAX_QUEUE_SIZE) &&
651 (0 != memcmp (sender,
653 sizeof (struct GNUNET_PeerIdentity))) )
655 msize = sizeof (struct RouteMessage) + ntohs (payload->size);
656 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
661 pm = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
662 pm->msg = (const struct GNUNET_MessageHeader *) &pm[1];
663 rm = (struct RouteMessage *) &pm[1];
664 rm->header.size = htons ((uint16_t) msize);
665 rm->header.type = htons (GNUNET_MESSAGE_TYPE_DV_ROUTE);
666 rm->distance = htonl (distance);
667 rm->target = target->peer;
668 rm->sender = *sender;
669 memcpy (&rm[1], payload, ntohs (payload->size));
670 GNUNET_CONTAINER_DLL_insert_tail (target->pm_head,
673 target->pm_queue_size++;
674 if (NULL == target->cth)
675 target->cth = GNUNET_CORE_notify_transmit_ready (core_api,
676 GNUNET_YES /* cork */,
678 GNUNET_TIME_UNIT_FOREVER_REL,
681 &core_transmit_notify, target);
686 * Find a free slot for storing a 'route' in the 'consensi'
687 * set at the given distance.
689 * @param distance distance to use for the set slot
692 get_consensus_slot (uint32_t distance)
694 struct ConsensusSet *cs;
697 cs = &consensi[distance];
699 while ( (i < cs->array_length) &&
700 (NULL != cs->targets[i]) ) i++;
701 if (i == cs->array_length)
702 GNUNET_array_grow (cs->targets,
704 cs->array_length * 2 + 2);
710 * Allocate a slot in the consensus set for a route.
712 * @param route route to initialize
713 * @param distance which consensus set to use
716 allocate_route (struct Route *route,
721 i = get_consensus_slot (distance);
722 route->set_offset = i;
723 consensi[distance].targets[i] = route;
724 route->target.distance = htonl (distance);
729 * Release a slot in the consensus set for a route.
731 * @param route route to release the slot from
734 release_route (struct Route *route)
736 consensi[ntohl (route->target.distance)].targets[route->set_offset] = NULL;
737 route->set_offset = UINT_MAX; /* indicate invalid slot */
742 * Move a route from one consensus set to another.
744 * @param route route to move
745 * @param new_distance new distance for the route (destination set)
748 move_route (struct Route *route,
749 uint32_t new_distance)
753 release_route (route);
754 i = get_consensus_slot (new_distance);
755 route->set_offset = i;
756 consensi[new_distance].targets[i] = route;
757 route->target.distance = htonl (new_distance);
762 * Start creating a new consensus from scratch.
764 * @param cls the 'struct DirectNeighbor' of the peer we're building
765 * a routing consensus with
766 * @param tc scheduler context
769 start_consensus (void *cls,
770 const struct GNUNET_SCHEDULER_TaskContext *tc);
774 * Method called whenever a peer connects.
777 * @param peer peer identity this notification is about
778 * @param atsi performance data
779 * @param atsi_count number of entries in atsi
782 handle_core_connect (void *cls, const struct GNUNET_PeerIdentity *peer,
783 const struct GNUNET_ATS_Information *atsi,
784 unsigned int atsi_count)
786 struct DirectNeighbor *neighbor;
790 /* Check for connect to self message */
791 if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
793 distance = get_atsi_distance (atsi, atsi_count);
794 neighbor = GNUNET_CONTAINER_multihashmap_get (direct_neighbors,
796 if (NULL != neighbor)
801 if (DIRECT_NEIGHBOR_COST != distance)
802 return; /* is a DV-neighbor */
803 neighbor = GNUNET_malloc (sizeof (struct DirectNeighbor));
804 neighbor->peer = *peer;
805 GNUNET_assert (GNUNET_YES ==
806 GNUNET_CONTAINER_multihashmap_put (direct_neighbors,
809 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
810 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
814 send_disconnect_to_plugin (peer);
815 release_route (route);
818 route->next_hop = neighbor;
819 neighbor->consensus_task = GNUNET_SCHEDULER_add_now (&start_consensus,
825 * Called for each 'target' in a neighbor table to free the associated memory.
828 * @param key key of the value
829 * @param value value to free
830 * @return GNUNET_OK to continue to iterate
833 free_targets (void *cls,
834 const struct GNUNET_HashCode *key,
843 * Multihashmap iterator for checking if a given route is
844 * (now) useful to this peer.
846 * @param cls the direct neighbor for the given route
847 * @param key key value stored under
848 * @param value a 'struct Target' that may or may not be useful; not that
849 * the distance in 'target' does not include the first hop yet
850 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
853 check_possible_route (void *cls, const struct GNUNET_HashCode * key, void *value)
855 struct DirectNeighbor *neighbor = cls;
856 struct Target *target = value;
859 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
863 if (ntohl (route->target.distance) > ntohl (target->distance) + 1)
865 /* this 'target' is cheaper than the existing route; switch to alternative route! */
866 move_route (route, ntohl (target->distance) + 1);
867 route->next_hop = neighbor;
868 // FIXME: notify plugin about distance update?
870 return GNUNET_YES; /* got a route to this target already */
872 route = GNUNET_malloc (sizeof (struct Route));
873 route->next_hop = neighbor;
874 route->target.distance = htonl (ntohl (target->distance) + 1);
875 route->target.peer = target->peer;
876 allocate_route (route, ntohl (route->target.distance));
877 GNUNET_assert (GNUNET_YES ==
878 GNUNET_CONTAINER_multihashmap_put (all_routes,
879 &route->target.peer.hashPubKey,
881 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
882 send_connect_to_plugin (&route->target.peer, ntohl (target->distance));
888 * Multihashmap iterator for finding routes that were previously
889 * "hidden" due to a better route (called after a disconnect event).
892 * @param key peer identity of the given direct neighbor
893 * @param value a 'struct DirectNeighbor' to check for additional routes
894 * @return GNUNET_YES to continue iteration
897 refresh_routes (void *cls, const struct GNUNET_HashCode * key, void *value)
899 struct DirectNeighbor *neighbor = value;
901 if (NULL != neighbor->neighbor_table)
902 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table,
903 &check_possible_route,
910 * Check if a target was removed from the set of the other peer; if so,
911 * if we also used it for our route, we need to remove it from our
912 * 'all_routes' set (and later check if an alternative path now exists).
914 * @param cls the 'struct DirectNeighbor'
915 * @param key peer identity for the target
916 * @param value a 'struct Target' previously reachable via the given neighbor
919 check_target_removed (void *cls,
920 const struct GNUNET_HashCode *key,
923 struct DirectNeighbor *neighbor = cls;
924 struct Target *new_target;
925 struct Route *current_route;
927 new_target = GNUNET_CONTAINER_multihashmap_get (neighbor->neighbor_table_consensus,
929 if (NULL == new_target)
931 /* target was revoked, check if it was used */
932 current_route = GNUNET_CONTAINER_multihashmap_get (all_routes,
934 if ( (NULL == current_route) ||
935 (current_route->next_hop != neighbor) )
937 /* didn't matter, wasn't used */
940 /* remove existing route */
941 GNUNET_assert (GNUNET_YES ==
942 GNUNET_CONTAINER_multihashmap_remove (all_routes, key, current_route));
943 send_disconnect_to_plugin (¤t_route->target.peer);
944 GNUNET_free (current_route);
945 neighbor->target_removed = GNUNET_YES;
953 * Check if a target was added to the set of the other peer; if it
954 * was added or impoves the existing route, do the needed updates.
956 * @param cls the 'struct DirectNeighbor'
957 * @param key peer identity for the target
958 * @param value a 'struct Target' now reachable via the given neighbor
961 check_target_added (void *cls,
962 const struct GNUNET_HashCode *key,
965 struct DirectNeighbor *neighbor = cls;
966 struct Target *target = value;
967 struct Route *current_route;
969 /* target was revoked, check if it was used */
970 current_route = GNUNET_CONTAINER_multihashmap_get (all_routes,
972 if (NULL != current_route)
975 if (current_route->next_hop == neighbor)
977 /* we had the same route before, no change */
978 if (ntohl (target->distance) != ntohl (current_route->target.distance))
980 current_route->target.distance = target->distance;
981 // FIXME: notify about distance change...
985 if (ntohl (current_route->target.distance) >= ntohl (target->distance))
987 /* alternative, shorter route exists, ignore */
990 /* new route is better than the existing one, take over! */
991 /* NOTE: minor security issue: malicious peers may advertise
992 very short routes to take over longer paths; as we don't
993 check that the shorter routes actually work, a malicious
994 direct neighbor can use this to DoS our long routes */
995 current_route->next_hop = neighbor;
996 current_route->target.distance = target->distance;
997 // FIXME: notify about distance change
1001 current_route = GNUNET_malloc (sizeof (struct Route));
1002 current_route->next_hop = neighbor;
1003 current_route->target.peer = target->peer;
1004 current_route->target.distance = htonl (ntohl (target->distance) + 1);
1005 GNUNET_assert (GNUNET_YES ==
1006 GNUNET_CONTAINER_multihashmap_put (all_routes,
1007 ¤t_route->target.peer.hashPubKey,
1009 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
1010 send_connect_to_plugin (¤t_route->target.peer,
1011 ntohl (current_route->target.distance));
1018 * The consensus has concluded, clean up and schedule the next one.
1020 * @param cls the 'struct GNUNET_DirectNeighbor' with which we created the consensus
1021 * @param group FIXME
1024 consensus_done_cb (void *cls,
1025 const struct GNUNET_CONSENSUS_Group *group)
1027 struct DirectNeighbor *neighbor = cls;
1029 GNUNET_CONSENSUS_destroy (neighbor->consensus);
1030 neighbor->consensus = NULL;
1031 /* remove targets that disappeared */
1032 neighbor->target_removed = GNUNET_NO;
1033 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table,
1034 &check_target_removed,
1036 if (GNUNET_YES == neighbor->target_removed)
1038 /* check if we got an alternative for the removed routes */
1039 GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
1043 /* add targets that appeared (and check for improved routes) */
1044 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table_consensus,
1045 &check_target_added,
1047 if (NULL != neighbor->neighbor_table)
1049 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table,
1052 GNUNET_CONTAINER_multihashmap_destroy (neighbor->neighbor_table);
1053 neighbor->neighbor_table = NULL;
1055 neighbor->neighbor_table = neighbor->neighbor_table_consensus;
1056 neighbor->neighbor_table_consensus = NULL;
1057 neighbor->consensus_task = GNUNET_SCHEDULER_add_delayed (GNUNET_DV_CONSENSUS_FREQUENCY,
1064 * We inserted the last element into the consensus, get ready to
1065 * insert the next element into the consensus or conclude if
1068 * @param cls the 'struct DirectNeighbor' of the peer we're building
1069 * a routing consensus with
1070 * @param success GNUNET_OK if the last element was added successfully,
1071 * GNUNET_SYSERR if we failed
1074 insert_next_element (void *cls,
1077 struct DirectNeighbor *neighbor = cls;
1078 struct GNUNET_CONSENSUS_Element element;
1080 while ( (DEFAULT_FISHEYE_DEPTH - 1 > neighbor->consensus_insertion_distance) &&
1081 (consensi[neighbor->consensus_insertion_distance].array_length == neighbor->consensus_insertion_offset) )
1083 neighbor->consensus_insertion_offset = 0;
1084 neighbor->consensus_insertion_distance++;
1085 /* skip over NULL entries */
1086 while ( (DEFAULT_FISHEYE_DEPTH - 1 > neighbor->consensus_insertion_distance) &&
1087 (consensi[neighbor->consensus_insertion_distance].array_length < neighbor->consensus_insertion_offset) &&
1088 (NULL == consensi[neighbor->consensus_insertion_distance].targets[neighbor->consensus_insertion_offset]) )
1089 neighbor->consensus_insertion_offset++;
1091 if (DEFAULT_FISHEYE_DEPTH - 1 == neighbor->consensus_insertion_distance)
1093 /* we're done, conclude! */
1094 GNUNET_CONSENSUS_conclude (neighbor->consensus,
1095 GNUNET_DV_CONSENSUS_FREQUENCY,
1101 element.size = sizeof (struct Target);
1102 element.data = &consensi[neighbor->consensus_insertion_distance].targets[neighbor->consensus_insertion_offset++]->target;
1104 /* skip over NULL entries */
1105 while ( (DEFAULT_FISHEYE_DEPTH - 1 > neighbor->consensus_insertion_distance) &&
1106 (consensi[neighbor->consensus_insertion_distance].array_length < neighbor->consensus_insertion_offset) &&
1107 (NULL == consensi[neighbor->consensus_insertion_distance].targets[neighbor->consensus_insertion_offset]) )
1108 neighbor->consensus_insertion_offset++;
1109 GNUNET_CONSENSUS_insert (neighbor->consensus,
1111 &insert_next_element,
1117 * We have learned a new route from the other peer. Add it to the
1118 * route set we're building.
1120 * @param cls the 'struct DirectNeighbor' we're building the consensus with
1121 * @param element the new element we have learned
1122 * @return GNUNET_OK if the valid is well-formed and should be added to the consensus,
1123 * GNUNET_SYSERR if the element should be ignored and not be propagated
1126 learn_route_cb (void *cls,
1127 const struct GNUNET_CONSENSUS_Element *element)
1129 struct DirectNeighbor *neighbor = cls;
1130 struct Target *target;
1132 if (sizeof (struct Target) != element->size)
1134 GNUNET_break_op (0);
1135 return GNUNET_SYSERR;
1137 target = GNUNET_malloc (sizeof (struct Target));
1138 memcpy (target, element->data, sizeof (struct Target));
1140 GNUNET_CONTAINER_multihashmap_put (neighbor->neighbor_table_consensus,
1141 &target->peer.hashPubKey,
1143 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
1145 GNUNET_break_op (0);
1146 GNUNET_free (target);
1147 return GNUNET_SYSERR;
1154 * Start creating a new consensus from scratch.
1156 * @param cls the 'struct DirectNeighbor' of the peer we're building
1157 * a routing consensus with
1158 * @param tc scheduler context
1161 start_consensus (void *cls,
1162 const struct GNUNET_SCHEDULER_TaskContext *tc)
1164 struct DirectNeighbor *neighbor = cls;
1165 struct GNUNET_HashCode session_id;
1166 struct GNUNET_HashCode real_session_id;
1168 neighbor->consensus_task = GNUNET_SCHEDULER_NO_TASK;
1169 neighbor->consensus_insertion_offset = 0;
1170 neighbor->consensus_insertion_distance = 0;
1171 GNUNET_assert (NULL == neighbor->neighbor_table_consensus);
1172 GNUNET_assert (NULL == neighbor->consensus);
1173 neighbor->neighbor_table_consensus = GNUNET_CONTAINER_multihashmap_create (1024, GNUNET_YES);
1174 /* construct session ID seed as XOR of both peer's identities */
1175 GNUNET_CRYPTO_hash_xor (&my_identity.hashPubKey,
1176 &neighbor->peer.hashPubKey,
1178 /* make sure session ID is unique across applications by salting it with 'DV' */
1179 GNUNET_CRYPTO_hkdf (&real_session_id, sizeof (real_session_id),
1180 GCRY_MD_SHA512, GCRY_MD_SHA256,
1182 &session_id, sizeof (session_id),
1184 neighbor->consensus = GNUNET_CONSENSUS_create (cfg,
1190 if (NULL == neighbor->consensus)
1192 neighbor->consensus_task = GNUNET_SCHEDULER_add_delayed (GNUNET_DV_CONSENSUS_FREQUENCY,
1197 insert_next_element (neighbor, GNUNET_OK);
1202 * Core handler for DV data messages. Whatever this message
1203 * contains all we really have to do is rip it out of its
1204 * DV layering and give it to our pal the DV plugin to report
1207 * @param cls closure
1208 * @param peer peer which sent the message (immediate sender)
1209 * @param message the message
1210 * @param atsi transport ATS information (latency, distance, etc.)
1211 * @param atsi_count number of entries in atsi
1212 * @return GNUNET_OK on success, GNUNET_SYSERR if the other peer violated the protocol
1215 handle_dv_route_message (void *cls, const struct GNUNET_PeerIdentity *peer,
1216 const struct GNUNET_MessageHeader *message,
1217 const struct GNUNET_ATS_Information *atsi,
1218 unsigned int atsi_count)
1220 const struct RouteMessage *rm;
1221 const struct GNUNET_MessageHeader *payload;
1222 struct Route *route;
1224 if (ntohs (message->size) < sizeof (struct RouteMessage) + sizeof (struct GNUNET_MessageHeader))
1226 GNUNET_break_op (0);
1227 return GNUNET_SYSERR;
1229 rm = (const struct RouteMessage *) message;
1230 payload = (const struct GNUNET_MessageHeader *) &rm[1];
1231 if (ntohs (message->size) != sizeof (struct RouteMessage) + ntohs (payload->size))
1233 GNUNET_break_op (0);
1234 return GNUNET_SYSERR;
1236 if (0 == memcmp (&rm->target,
1238 sizeof (struct GNUNET_PeerIdentity)))
1240 /* message is for me, check reverse route! */
1241 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
1242 &rm->sender.hashPubKey);
1245 /* don't have reverse route, drop */
1246 GNUNET_STATISTICS_update (stats,
1247 "# message discarded (no reverse route)",
1251 send_data_to_plugin (payload,
1253 ntohl (route->target.distance));
1256 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
1257 &rm->target.hashPubKey);
1260 GNUNET_STATISTICS_update (stats,
1261 "# messages discarded (no route)",
1265 if (ntohl (route->target.distance) > ntohl (rm->distance) + 1)
1267 GNUNET_STATISTICS_update (stats,
1268 "# messages discarded (target too far)",
1272 forward_payload (route->next_hop,
1273 ntohl (route->target.distance),
1281 * Service server's handler for message send requests (which come
1282 * bubbling up to us through the DV plugin).
1284 * @param cls closure
1285 * @param client identification of the client
1286 * @param message the actual message
1289 handle_dv_send_message (void *cls, struct GNUNET_SERVER_Client *client,
1290 const struct GNUNET_MessageHeader *message)
1292 struct Route *route;
1293 const struct GNUNET_DV_SendMessage *msg;
1294 const struct GNUNET_MessageHeader *payload;
1296 if (ntohs (message->size) < sizeof (struct GNUNET_DV_SendMessage) + sizeof (struct GNUNET_MessageHeader))
1299 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1302 msg = (const struct GNUNET_DV_SendMessage *) message;
1303 payload = (const struct GNUNET_MessageHeader *) &msg[1];
1304 if (ntohs (message->size) != sizeof (struct GNUNET_DV_SendMessage) + ntohs (payload->size))
1307 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1310 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
1311 &msg->target.hashPubKey);
1314 /* got disconnected, send ACK anyway?
1315 FIXME: What we really want is an 'NACK' here... */
1316 GNUNET_STATISTICS_update (stats,
1317 "# local messages discarded (no route)",
1319 send_ack_to_plugin (&msg->target, htonl (msg->uid));
1320 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1323 // FIXME: flow control (send ACK only once message has left the queue...)
1324 send_ack_to_plugin (&msg->target, htonl (msg->uid));
1325 forward_payload (route->next_hop,
1326 ntohl (route->target.distance),
1329 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1334 * Multihashmap iterator for freeing routes that go via a particular
1335 * neighbor that disconnected and is thus no longer available.
1337 * @param cls the direct neighbor that is now unavailable
1338 * @param key key value stored under
1339 * @param value a 'struct Route' that may or may not go via neighbor
1341 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
1344 cull_routes (void *cls, const struct GNUNET_HashCode * key, void *value)
1346 struct DirectNeighbor *neighbor = cls;
1347 struct Route *route = value;
1349 if (route->next_hop != neighbor)
1350 return GNUNET_YES; /* not affected */
1351 GNUNET_assert (GNUNET_YES ==
1352 GNUNET_CONTAINER_multihashmap_remove (all_routes, key, value));
1353 release_route (route);
1354 send_disconnect_to_plugin (&route->target.peer);
1355 GNUNET_free (route);
1361 * Cleanup all of the data structures associated with a given neighbor.
1363 * @param neighbor neighbor to clean up
1366 cleanup_neighbor (struct DirectNeighbor *neighbor)
1368 struct PendingMessage *pending;
1370 while (NULL != (pending = neighbor->pm_head))
1372 neighbor->pm_queue_size--;
1373 GNUNET_CONTAINER_DLL_remove (neighbor->pm_head,
1376 GNUNET_free (pending);
1378 GNUNET_CONTAINER_multihashmap_iterate (all_routes,
1381 if (NULL != neighbor->cth)
1383 GNUNET_CORE_notify_transmit_ready_cancel (neighbor->cth);
1384 neighbor->cth = NULL;
1386 if (NULL != neighbor->neighbor_table_consensus)
1388 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table_consensus,
1391 GNUNET_CONTAINER_multihashmap_destroy (neighbor->neighbor_table_consensus);
1392 neighbor->neighbor_table_consensus = NULL;
1394 if (NULL != neighbor->neighbor_table)
1396 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table,
1399 GNUNET_CONTAINER_multihashmap_destroy (neighbor->neighbor_table);
1400 neighbor->neighbor_table = NULL;
1402 if (GNUNET_SCHEDULER_NO_TASK != neighbor->consensus_task)
1404 GNUNET_SCHEDULER_cancel (neighbor->consensus_task);
1405 neighbor->consensus_task = GNUNET_SCHEDULER_NO_TASK;
1407 if (NULL != neighbor->consensus)
1409 GNUNET_CONSENSUS_destroy (neighbor->consensus);
1410 neighbor->consensus = NULL;
1412 GNUNET_assert (GNUNET_YES ==
1413 GNUNET_CONTAINER_multihashmap_remove (direct_neighbors,
1414 &neighbor->peer.hashPubKey,
1416 GNUNET_free (neighbor);
1421 * Method called whenever a given peer disconnects.
1423 * @param cls closure
1424 * @param peer peer identity this notification is about
1427 handle_core_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer)
1429 struct DirectNeighbor *neighbor;
1431 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1432 "Received core peer disconnect message for peer `%s'!\n",
1434 /* Check for disconnect from self message */
1435 if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
1438 GNUNET_CONTAINER_multihashmap_get (direct_neighbors, &peer->hashPubKey);
1439 if (NULL == neighbor)
1441 /* must have been a DV-neighbor, ignore */
1444 cleanup_neighbor (neighbor);
1445 GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
1452 * Multihashmap iterator for freeing routes. Should never be called.
1455 * @param key key value stored under
1456 * @param value the route to be freed
1458 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
1461 free_route (void *cls, const struct GNUNET_HashCode * key, void *value)
1463 struct Route *route = value;
1466 GNUNET_assert (GNUNET_YES ==
1467 GNUNET_CONTAINER_multihashmap_remove (all_routes, key, value));
1468 release_route (route);
1469 send_disconnect_to_plugin (&route->target.peer);
1470 GNUNET_free (route);
1476 * Multihashmap iterator for freeing direct neighbors. Should never be called.
1479 * @param key key value stored under
1480 * @param value the direct neighbor to be freed
1482 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
1485 free_direct_neighbors (void *cls, const struct GNUNET_HashCode * key, void *value)
1487 struct DirectNeighbor *neighbor = value;
1490 cleanup_neighbor (neighbor);
1496 * Task run during shutdown.
1502 shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1504 struct PendingMessage *pending;
1507 GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
1508 &free_direct_neighbors, NULL);
1509 GNUNET_CONTAINER_multihashmap_destroy (direct_neighbors);
1510 GNUNET_CONTAINER_multihashmap_iterate (all_routes,
1512 GNUNET_CONTAINER_multihashmap_destroy (all_routes);
1513 GNUNET_CORE_disconnect (core_api);
1515 GNUNET_STATISTICS_destroy (stats, GNUNET_NO);
1517 while (NULL != (pending = plugin_pending_head))
1519 GNUNET_CONTAINER_DLL_remove (plugin_pending_head,
1520 plugin_pending_tail,
1522 GNUNET_free (pending);
1524 for (i=0;i<DEFAULT_FISHEYE_DEPTH - 1;i++)
1525 GNUNET_array_grow (consensi[i].targets,
1526 consensi[i].array_length,
1532 * Handle START-message. This is the first message sent to us
1533 * by the client (can only be one!).
1535 * @param cls closure (always NULL)
1536 * @param client identification of the client
1537 * @param message the actual message
1540 handle_start (void *cls, struct GNUNET_SERVER_Client *client,
1541 const struct GNUNET_MessageHeader *message)
1543 if (NULL != client_handle)
1545 /* forcefully drop old client */
1546 GNUNET_SERVER_client_disconnect (client_handle);
1547 GNUNET_SERVER_client_drop (client_handle);
1549 client_handle = client;
1550 GNUNET_SERVER_client_keep (client_handle);
1551 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1556 * Called on core init.
1559 * @param server legacy
1560 * @param identity this peer's identity
1563 core_init (void *cls, struct GNUNET_CORE_Handle *server,
1564 const struct GNUNET_PeerIdentity *identity)
1566 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1568 GNUNET_i2s (identity));
1569 my_identity = *identity;
1574 * Process dv requests.
1576 * @param cls closure
1577 * @param server the initialized server
1578 * @param c configuration to use
1581 run (void *cls, struct GNUNET_SERVER_Handle *server,
1582 const struct GNUNET_CONFIGURATION_Handle *c)
1584 static struct GNUNET_CORE_MessageHandler core_handlers[] = {
1585 {&handle_dv_route_message, GNUNET_MESSAGE_TYPE_DV_ROUTE, 0},
1588 static struct GNUNET_SERVER_MessageHandler plugin_handlers[] = {
1589 {&handle_start, NULL,
1590 GNUNET_MESSAGE_TYPE_DV_START,
1591 sizeof (struct GNUNET_MessageHeader) },
1592 { &handle_dv_send_message, NULL,
1593 GNUNET_MESSAGE_TYPE_DV_SEND,
1599 direct_neighbors = GNUNET_CONTAINER_multihashmap_create (128, GNUNET_NO);
1600 all_routes = GNUNET_CONTAINER_multihashmap_create (65536, GNUNET_NO);
1601 core_api = GNUNET_CORE_connect (cfg, NULL,
1603 &handle_core_connect,
1604 &handle_core_disconnect,
1609 if (NULL == core_api)
1611 stats = GNUNET_STATISTICS_create ("dv", cfg);
1612 GNUNET_SERVER_add_handlers (server, plugin_handlers);
1613 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
1614 &shutdown_task, NULL);
1619 * The main function for the dv service.
1621 * @param argc number of arguments from the command line
1622 * @param argv command line arguments
1623 * @return 0 ok, 1 on error
1626 main (int argc, char *const *argv)
1628 return (GNUNET_OK ==
1629 GNUNET_SERVICE_run (argc, argv, "dv", GNUNET_SERVICE_OPTION_NONE,
1630 &run, NULL)) ? 0 : 1;
1633 /* end of gnunet-service-dv.c */