2 This file is part of GNUnet.
3 (C) 2013 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file 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 #include "gnunet_util_lib.h"
32 #include "gnunet_protocols.h"
33 #include "gnunet_core_service.h"
34 #include "gnunet_hello_lib.h"
35 #include "gnunet_peerinfo_service.h"
36 #include "gnunet_statistics_service.h"
37 #include "gnunet_consensus_service.h"
38 #include "gnunet_ats_service.h"
44 * How often do we establish the consensu?
46 #define GNUNET_DV_CONSENSUS_FREQUENCY GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 5)
49 * Maximum number of messages we queue per peer.
51 #define MAX_QUEUE_SIZE 16
54 * Maximum number of messages we queue towards the clients/plugin.
56 #define MAX_QUEUE_SIZE_PLUGIN 1024
59 * The default fisheye depth, from how many hops away will
62 #define DEFAULT_FISHEYE_DEPTH 3
65 * How many hops is a direct neighbor away?
67 #define DIRECT_NEIGHBOR_COST 1
70 GNUNET_NETWORK_STRUCT_BEGIN
73 * Information about a peer DV can route to. These entries are what
74 * we use as the binary format to establish consensus to create our
75 * routing table and as the address format in the HELLOs.
81 * Identity of the peer we can reach.
83 struct GNUNET_PeerIdentity peer;
86 * How many hops (1-3) is this peer away? in network byte order
88 uint32_t distance GNUNET_PACKED;
94 * Message exchanged between DV services (via core), requesting a
95 * message to be routed.
100 * Type: GNUNET_MESSAGE_TYPE_DV_ROUTE
102 struct GNUNET_MessageHeader header;
105 * Expected (remaining) distance. Must be always smaller than
106 * DEFAULT_FISHEYE_DEPTH, should be zero at the target. Must
107 * be decremented by one at each hop. Peers must not forward
108 * these messages further once the counter has reached zero.
110 uint32_t distance GNUNET_PACKED;
113 * The (actual) target of the message (this peer, if distance is zero).
115 struct GNUNET_PeerIdentity target;
118 * The (actual) sender of the message.
120 struct GNUNET_PeerIdentity sender;
124 GNUNET_NETWORK_STRUCT_END
128 * Linked list of messages to send to clients.
130 struct PendingMessage
133 * Pointer to next item in the list
135 struct PendingMessage *next;
138 * Pointer to previous item in the list
140 struct PendingMessage *prev;
143 * Actual message to be sent, allocated after this struct.
145 const struct GNUNET_MessageHeader *msg;
148 * Ultimate target for the message.
150 struct GNUNET_PeerIdentity ultimate_target;
153 * Unique ID of the message.
161 * Information about a direct neighbor (core-level, excluding
162 * DV-links, only DV-enabled peers).
164 struct DirectNeighbor
168 * Identity of the peer.
170 struct GNUNET_PeerIdentity peer;
173 * Head of linked list of messages to send to this peer.
175 struct PendingMessage *pm_head;
178 * Tail of linked list of messages to send to this peer.
180 struct PendingMessage *pm_tail;
183 * Transmit handle to core service.
185 struct GNUNET_CORE_TransmitHandle *cth;
188 * Routing table of the neighbor, NULL if not yet established.
189 * Keys are peer identities, values are 'struct Target' entries.
190 * Note that the distances in the targets are from the point-of-view
191 * of the peer, not from us!
193 struct GNUNET_CONTAINER_MultiHashMap *neighbor_table;
196 * Updated routing table of the neighbor, under construction,
197 * NULL if we are not currently building it.
198 * Keys are peer identities, values are 'struct Target' entries.
199 * Note that the distances in the targets are from the point-of-view
200 * of the peer, not from us!
202 struct GNUNET_CONTAINER_MultiHashMap *neighbor_table_consensus;
205 * Active consensus, if we are currently synchronizing the
208 struct GNUNET_CONSENSUS_Handle *consensus;
211 * ID of the task we use to (periodically) update our consensus
214 GNUNET_SCHEDULER_TaskIdentifier consensus_task;
217 * At what offset are we, with respect to inserting our own routes
218 * into the consensus?
220 unsigned int consensus_insertion_offset;
223 * At what distance are we, with respect to inserting our own routes
224 * into the consensus?
226 unsigned int consensus_insertion_distance;
229 * Number of messages currently in the 'pm_XXXX'-DLL.
231 unsigned int pm_queue_size;
234 * Flag set within 'check_target_removed' to trigger full global route refresh.
239 * Our distance to this peer, 0 for unknown.
244 * Is this neighbor connected at the core level?
252 * A route includes information about the next hop,
253 * the target, and the ultimate distance to the
260 * Which peer do we need to forward the message to?
262 struct DirectNeighbor *next_hop;
265 * What would be the target, and how far is it away?
267 struct Target target;
270 * Offset of this target in the respective consensus set.
272 unsigned int set_offset;
278 * Set of targets we bring to a consensus; all targets in a set have a
279 * distance equal to the sets distance (which is implied by the array
286 * Array of targets in the set, may include NULL entries if a
287 * neighbor has disconnected; the targets are allocated with the
288 * respective container (all_routes), not here.
290 struct Route **targets;
293 * Size of the 'targets' array.
295 unsigned int array_length;
301 * Hashmap of all of our neighbors; processing these usually requires
302 * first checking to see if the peer is core-connected and if the
303 * distance is 1, in which case they are direct neighbors.
305 static struct GNUNET_CONTAINER_MultiHashMap *direct_neighbors;
308 * Hashmap with all routes that we currently support; contains
309 * routing information for all peers from distance 2
310 * up to distance DEFAULT_FISHEYE_DEPTH.
312 static struct GNUNET_CONTAINER_MultiHashMap *all_routes;
315 * Array of consensus sets we expose to the outside world. Sets
316 * are structured by the distance to the target.
318 static struct ConsensusSet consensi[DEFAULT_FISHEYE_DEPTH - 1];
321 * Handle to the core service api.
323 static struct GNUNET_CORE_Handle *core_api;
326 * The identity of our peer.
328 static struct GNUNET_PeerIdentity my_identity;
331 * The configuration for this service.
333 static const struct GNUNET_CONFIGURATION_Handle *cfg;
336 * The client, the DV plugin connected to us (or an event monitor).
337 * Hopefully this client will never change, although if the plugin
338 * dies and returns for some reason it may happen.
340 static struct GNUNET_SERVER_NotificationContext *nc;
343 * Handle for the statistics service.
345 static struct GNUNET_STATISTICS_Handle *stats;
348 * Handle to ATS service.
350 static struct GNUNET_ATS_PerformanceHandle *ats;
354 * Start creating a new consensus from scratch.
356 * @param cls the 'struct DirectNeighbor' of the peer we're building
357 * a routing consensus with
358 * @param tc scheduler context
361 start_consensus (void *cls,
362 const struct GNUNET_SCHEDULER_TaskContext *tc);
366 * Forward a message from another peer to the plugin.
368 * @param message the message to send to the plugin
369 * @param origin the original sender of the message
370 * @param distance distance to the original sender of the message
373 send_data_to_plugin (const struct GNUNET_MessageHeader *message,
374 const struct GNUNET_PeerIdentity *origin,
377 struct GNUNET_DV_ReceivedMessage *received_msg;
380 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
381 "Delivering message from peer `%s'\n",
382 GNUNET_i2s (origin));
383 size = sizeof (struct GNUNET_DV_ReceivedMessage) +
384 ntohs (message->size);
385 if (size >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
387 GNUNET_break (0); /* too big */
390 received_msg = GNUNET_malloc (size);
391 received_msg->header.size = htons (size);
392 received_msg->header.type = htons (GNUNET_MESSAGE_TYPE_DV_RECV);
393 received_msg->distance = htonl (distance);
394 received_msg->sender = *origin;
395 memcpy (&received_msg[1], message, ntohs (message->size));
396 GNUNET_SERVER_notification_context_broadcast (nc,
397 &received_msg->header,
399 GNUNET_free (received_msg);
404 * Forward a control message to the plugin.
406 * @param message the message to send to the plugin
409 send_control_to_plugin (const struct GNUNET_MessageHeader *message)
411 GNUNET_SERVER_notification_context_broadcast (nc,
418 * Give an (N)ACK message to the plugin, we transmitted a message for it.
420 * @param target peer that received the message
421 * @param uid plugin-chosen UID for the message
422 * @param nack GNUNET_NO to send ACK, GNUNET_YES to send NACK
425 send_ack_to_plugin (const struct GNUNET_PeerIdentity *target,
429 struct GNUNET_DV_AckMessage ack_msg;
431 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
432 "Delivering ACK for message to peer `%s'\n",
433 GNUNET_i2s (target));
434 ack_msg.header.size = htons (sizeof (ack_msg));
435 ack_msg.header.type = htons ((GNUNET_YES == nack)
436 ? GNUNET_MESSAGE_TYPE_DV_SEND_NACK
437 : GNUNET_MESSAGE_TYPE_DV_SEND_ACK);
438 ack_msg.uid = htonl (uid);
439 ack_msg.target = *target;
440 send_control_to_plugin (&ack_msg.header);
445 * Send a DISTANCE_CHANGED message to the plugin.
447 * @param peer peer with a changed distance
448 * @param distance new distance to the peer
451 send_distance_change_to_plugin (const struct GNUNET_PeerIdentity *peer,
454 struct GNUNET_DV_DistanceUpdateMessage du_msg;
456 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
457 "Delivering DISTANCE_CHANGED for message about peer `%s'\n",
459 du_msg.header.size = htons (sizeof (du_msg));
460 du_msg.header.type = htons (GNUNET_MESSAGE_TYPE_DV_DISTANCE_CHANGED);
461 du_msg.distance = htonl (distance);
463 send_control_to_plugin (&du_msg.header);
468 * Give a CONNECT message to the plugin.
470 * @param target peer that connected
471 * @param distance distance to the target
474 send_connect_to_plugin (const struct GNUNET_PeerIdentity *target,
477 struct GNUNET_DV_ConnectMessage cm;
479 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
480 "Delivering CONNECT about peer `%s'\n",
481 GNUNET_i2s (target));
482 cm.header.size = htons (sizeof (cm));
483 cm.header.type = htons (GNUNET_MESSAGE_TYPE_DV_CONNECT);
484 cm.distance = htonl (distance);
486 send_control_to_plugin (&cm.header);
491 * Give a DISCONNECT message to the plugin.
493 * @param target peer that disconnected
496 send_disconnect_to_plugin (const struct GNUNET_PeerIdentity *target)
498 struct GNUNET_DV_DisconnectMessage dm;
500 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
501 "Delivering DISCONNECT about peer `%s'\n",
502 GNUNET_i2s (target));
503 dm.header.size = htons (sizeof (dm));
504 dm.header.type = htons (GNUNET_MESSAGE_TYPE_DV_DISCONNECT);
505 dm.reserved = htonl (0);
507 send_control_to_plugin (&dm.header);
512 * Function called to transfer a message to another peer
515 * @param cls closure with the direct neighbor
516 * @param size number of bytes available in buf
517 * @param buf where the callee should write the message
518 * @return number of bytes written to buf
521 core_transmit_notify (void *cls, size_t size, void *buf)
523 struct DirectNeighbor *dn = cls;
525 struct PendingMessage *pending;
532 /* peer disconnected */
536 pending = dn->pm_head;
538 while ( (NULL != (pending = dn->pm_head)) &&
539 (size >= off + (msize = ntohs (pending->msg->size))))
542 GNUNET_CONTAINER_DLL_remove (dn->pm_head,
545 memcpy (&cbuf[off], pending->msg, msize);
546 if (0 != pending->uid)
547 send_ack_to_plugin (&pending->ultimate_target,
550 GNUNET_free (pending);
553 if (NULL != dn->pm_head)
555 GNUNET_CORE_notify_transmit_ready (core_api,
556 GNUNET_YES /* cork */,
558 GNUNET_TIME_UNIT_FOREVER_REL,
561 &core_transmit_notify, dn);
567 * Forward the given payload to the given target.
569 * @param target where to send the message
570 * @param uid unique ID for the message
571 * @param ultimate_target ultimate recipient for the message
572 * @param distance expected (remaining) distance to the target
573 * @param sender original sender of the message
574 * @param payload payload of the message
577 forward_payload (struct DirectNeighbor *target,
580 const struct GNUNET_PeerIdentity *sender,
581 const struct GNUNET_PeerIdentity *ultimate_target,
582 const struct GNUNET_MessageHeader *payload)
584 struct PendingMessage *pm;
585 struct RouteMessage *rm;
588 if ( (target->pm_queue_size >= MAX_QUEUE_SIZE) &&
589 (0 != memcmp (sender,
591 sizeof (struct GNUNET_PeerIdentity))) )
593 GNUNET_break (0 == uid);
596 msize = sizeof (struct RouteMessage) + ntohs (payload->size);
597 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
602 pm = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
603 pm->ultimate_target = *ultimate_target;
605 pm->msg = (const struct GNUNET_MessageHeader *) &pm[1];
606 rm = (struct RouteMessage *) &pm[1];
607 rm->header.size = htons ((uint16_t) msize);
608 rm->header.type = htons (GNUNET_MESSAGE_TYPE_DV_ROUTE);
609 rm->distance = htonl (distance);
610 rm->target = target->peer;
611 rm->sender = *sender;
612 memcpy (&rm[1], payload, ntohs (payload->size));
613 GNUNET_CONTAINER_DLL_insert_tail (target->pm_head,
616 target->pm_queue_size++;
617 if (NULL == target->cth)
618 target->cth = GNUNET_CORE_notify_transmit_ready (core_api,
619 GNUNET_YES /* cork */,
621 GNUNET_TIME_UNIT_FOREVER_REL,
624 &core_transmit_notify, target);
629 * Find a free slot for storing a 'route' in the 'consensi'
630 * set at the given distance.
632 * @param distance distance to use for the set slot
635 get_consensus_slot (uint32_t distance)
637 struct ConsensusSet *cs;
640 cs = &consensi[distance];
642 while ( (i < cs->array_length) &&
643 (NULL != cs->targets[i]) ) i++;
644 if (i == cs->array_length)
645 GNUNET_array_grow (cs->targets,
647 cs->array_length * 2 + 2);
653 * Allocate a slot in the consensus set for a route.
655 * @param route route to initialize
656 * @param distance which consensus set to use
659 allocate_route (struct Route *route,
664 i = get_consensus_slot (distance);
665 route->set_offset = i;
666 consensi[distance].targets[i] = route;
667 route->target.distance = htonl (distance);
672 * Release a slot in the consensus set for a route.
674 * @param route route to release the slot from
677 release_route (struct Route *route)
679 consensi[ntohl (route->target.distance)].targets[route->set_offset] = NULL;
680 route->set_offset = UINT_MAX; /* indicate invalid slot */
685 * Move a route from one consensus set to another.
687 * @param route route to move
688 * @param new_distance new distance for the route (destination set)
691 move_route (struct Route *route,
692 uint32_t new_distance)
696 release_route (route);
697 i = get_consensus_slot (new_distance);
698 route->set_offset = i;
699 consensi[new_distance].targets[i] = route;
700 route->target.distance = htonl (new_distance);
705 * A peer is now connected to us at distance 1. Initiate DV exchange.
707 * @param neighbor entry for the neighbor at distance 1
710 handle_direct_connect (struct DirectNeighbor *neighbor)
714 GNUNET_STATISTICS_update (stats,
715 "# peers connected (1-hop)",
717 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
718 &neighbor->peer.hashPubKey);
721 send_disconnect_to_plugin (&neighbor->peer);
722 release_route (route);
725 neighbor->consensus_task = GNUNET_SCHEDULER_add_now (&start_consensus,
731 * Method called whenever a peer connects.
734 * @param peer peer identity this notification is about
737 handle_core_connect (void *cls, const struct GNUNET_PeerIdentity *peer)
739 struct DirectNeighbor *neighbor;
741 /* Check for connect to self message */
742 if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
744 /* check if entry exists */
745 neighbor = GNUNET_CONTAINER_multihashmap_get (direct_neighbors,
747 if (NULL != neighbor)
749 GNUNET_break (GNUNET_YES != neighbor->connected);
750 neighbor->connected = GNUNET_YES;
751 if (DIRECT_NEIGHBOR_COST != neighbor->distance)
753 handle_direct_connect (neighbor);
756 neighbor = GNUNET_malloc (sizeof (struct DirectNeighbor));
757 neighbor->peer = *peer;
758 GNUNET_assert (GNUNET_YES ==
759 GNUNET_CONTAINER_multihashmap_put (direct_neighbors,
762 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
763 neighbor->connected = GNUNET_YES;
764 neighbor->distance = 0; /* unknown */
769 * Called for each 'target' in a neighbor table to free the associated memory.
772 * @param key key of the value
773 * @param value value to free
774 * @return GNUNET_OK to continue to iterate
777 free_targets (void *cls,
778 const struct GNUNET_HashCode *key,
787 * Multihashmap iterator for checking if a given route is
788 * (now) useful to this peer.
790 * @param cls the direct neighbor for the given route
791 * @param key key value stored under
792 * @param value a 'struct Target' that may or may not be useful; not that
793 * the distance in 'target' does not include the first hop yet
794 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
797 check_possible_route (void *cls, const struct GNUNET_HashCode * key, void *value)
799 struct DirectNeighbor *neighbor = cls;
800 struct Target *target = value;
803 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
807 if (ntohl (route->target.distance) > ntohl (target->distance) + 1)
809 /* this 'target' is cheaper than the existing route; switch to alternative route! */
810 move_route (route, ntohl (target->distance) + 1);
811 route->next_hop = neighbor;
812 send_distance_change_to_plugin (&target->peer, ntohl (target->distance) + 1);
814 return GNUNET_YES; /* got a route to this target already */
816 route = GNUNET_malloc (sizeof (struct Route));
817 route->next_hop = neighbor;
818 route->target.distance = htonl (ntohl (target->distance) + 1);
819 route->target.peer = target->peer;
820 allocate_route (route, ntohl (route->target.distance));
821 GNUNET_assert (GNUNET_YES ==
822 GNUNET_CONTAINER_multihashmap_put (all_routes,
823 &route->target.peer.hashPubKey,
825 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
826 send_connect_to_plugin (&route->target.peer, ntohl (target->distance));
832 * Multihashmap iterator for finding routes that were previously
833 * "hidden" due to a better route (called after a disconnect event).
836 * @param key peer identity of the given direct neighbor
837 * @param value a 'struct DirectNeighbor' to check for additional routes
838 * @return GNUNET_YES to continue iteration
841 refresh_routes (void *cls, const struct GNUNET_HashCode * key, void *value)
843 struct DirectNeighbor *neighbor = value;
845 if ( (GNUNET_YES != neighbor->connected) ||
846 (DIRECT_NEIGHBOR_COST != neighbor->distance) )
848 if (NULL != neighbor->neighbor_table)
849 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table,
850 &check_possible_route,
857 * Get distance information from 'atsi'.
859 * @param atsi performance data
860 * @param atsi_count number of entries in atsi
861 * @return connected transport distance
864 get_atsi_distance (const struct GNUNET_ATS_Information *atsi,
869 for (i = 0; i < atsi_count; i++)
870 if (ntohl (atsi[i].type) == GNUNET_ATS_QUALITY_NET_DISTANCE)
871 return ntohl (atsi->value);
872 /* If we do not have explicit distance data, assume direct neighbor. */
873 return DIRECT_NEIGHBOR_COST;
878 * Multihashmap iterator for freeing routes that go via a particular
879 * neighbor that disconnected and is thus no longer available.
881 * @param cls the direct neighbor that is now unavailable
882 * @param key key value stored under
883 * @param value a 'struct Route' that may or may not go via neighbor
885 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
888 cull_routes (void *cls, const struct GNUNET_HashCode * key, void *value)
890 struct DirectNeighbor *neighbor = cls;
891 struct Route *route = value;
893 if (route->next_hop != neighbor)
894 return GNUNET_YES; /* not affected */
895 GNUNET_assert (GNUNET_YES ==
896 GNUNET_CONTAINER_multihashmap_remove (all_routes, key, value));
897 release_route (route);
898 send_disconnect_to_plugin (&route->target.peer);
905 * Handle the case that a direct connection to a peer is
906 * disrupted. Remove all routes via that peer and
907 * stop the consensus with it.
909 * @param neighbor peer that was disconnected (or at least is no
910 * longer at distance 1)
913 handle_direct_disconnect (struct DirectNeighbor *neighbor)
915 GNUNET_CONTAINER_multihashmap_iterate (all_routes,
918 if (NULL != neighbor->cth)
920 GNUNET_CORE_notify_transmit_ready_cancel (neighbor->cth);
921 neighbor->cth = NULL;
923 if (NULL != neighbor->neighbor_table_consensus)
925 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table_consensus,
928 GNUNET_CONTAINER_multihashmap_destroy (neighbor->neighbor_table_consensus);
929 neighbor->neighbor_table_consensus = NULL;
931 if (NULL != neighbor->neighbor_table)
933 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table,
936 GNUNET_CONTAINER_multihashmap_destroy (neighbor->neighbor_table);
937 neighbor->neighbor_table = NULL;
939 if (GNUNET_SCHEDULER_NO_TASK != neighbor->consensus_task)
941 GNUNET_SCHEDULER_cancel (neighbor->consensus_task);
942 neighbor->consensus_task = GNUNET_SCHEDULER_NO_TASK;
944 if (NULL != neighbor->consensus)
946 GNUNET_CONSENSUS_destroy (neighbor->consensus);
947 neighbor->consensus = NULL;
953 * Function that is called with QoS information about an address; used
954 * to update our current distance to another peer.
957 * @param address the address
958 * @param active is this address in active use
959 * @param bandwidth_out assigned outbound bandwidth for the connection
960 * @param bandwidth_in assigned inbound bandwidth for the connection
961 * @param ats performance data for the address (as far as known)
962 * @param ats_count number of performance records in 'ats'
965 handle_ats_update (void *cls,
966 const struct GNUNET_HELLO_Address *address,
968 struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out,
969 struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in,
970 const struct GNUNET_ATS_Information *ats,
973 struct DirectNeighbor *neighbor;
976 if (GNUNET_NO == active)
978 distance = get_atsi_distance (ats, ats_count);
979 /* check if entry exists */
980 neighbor = GNUNET_CONTAINER_multihashmap_get (direct_neighbors,
981 &address->peer.hashPubKey);
982 if (NULL != neighbor)
984 if ( (DIRECT_NEIGHBOR_COST == neighbor->distance) &&
985 (DIRECT_NEIGHBOR_COST == distance) )
986 return; /* no change */
987 if (DIRECT_NEIGHBOR_COST == neighbor->distance)
989 neighbor->distance = distance;
990 GNUNET_STATISTICS_update (stats,
991 "# peers connected (1-hop)",
993 handle_direct_disconnect (neighbor);
994 GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
999 neighbor->distance = distance;
1000 if (DIRECT_NEIGHBOR_COST != neighbor->distance)
1002 if (GNUNET_YES != neighbor->connected)
1004 handle_direct_connect (neighbor);
1007 neighbor = GNUNET_malloc (sizeof (struct DirectNeighbor));
1008 neighbor->peer = address->peer;
1009 GNUNET_assert (GNUNET_YES ==
1010 GNUNET_CONTAINER_multihashmap_put (direct_neighbors,
1011 &address->peer.hashPubKey,
1013 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
1014 neighbor->connected = GNUNET_NO; /* not yet */
1015 neighbor->distance = distance;
1020 * Check if a target was removed from the set of the other peer; if so,
1021 * if we also used it for our route, we need to remove it from our
1022 * 'all_routes' set (and later check if an alternative path now exists).
1024 * @param cls the 'struct DirectNeighbor'
1025 * @param key peer identity for the target
1026 * @param value a 'struct Target' previously reachable via the given neighbor
1029 check_target_removed (void *cls,
1030 const struct GNUNET_HashCode *key,
1033 struct DirectNeighbor *neighbor = cls;
1034 struct Target *new_target;
1035 struct Route *current_route;
1037 new_target = GNUNET_CONTAINER_multihashmap_get (neighbor->neighbor_table_consensus,
1039 if (NULL == new_target)
1041 /* target was revoked, check if it was used */
1042 current_route = GNUNET_CONTAINER_multihashmap_get (all_routes,
1044 if ( (NULL == current_route) ||
1045 (current_route->next_hop != neighbor) )
1047 /* didn't matter, wasn't used */
1050 /* remove existing route */
1051 GNUNET_assert (GNUNET_YES ==
1052 GNUNET_CONTAINER_multihashmap_remove (all_routes, key, current_route));
1053 send_disconnect_to_plugin (¤t_route->target.peer);
1054 GNUNET_free (current_route);
1055 neighbor->target_removed = GNUNET_YES;
1063 * Check if a target was added to the set of the other peer; if it
1064 * was added or impoves the existing route, do the needed updates.
1066 * @param cls the 'struct DirectNeighbor'
1067 * @param key peer identity for the target
1068 * @param value a 'struct Target' now reachable via the given neighbor
1071 check_target_added (void *cls,
1072 const struct GNUNET_HashCode *key,
1075 struct DirectNeighbor *neighbor = cls;
1076 struct Target *target = value;
1077 struct Route *current_route;
1079 /* target was revoked, check if it was used */
1080 current_route = GNUNET_CONTAINER_multihashmap_get (all_routes,
1082 if (NULL != current_route)
1085 if (current_route->next_hop == neighbor)
1087 /* we had the same route before, no change */
1088 if (ntohl (target->distance) + 1 != ntohl (current_route->target.distance))
1090 current_route->target.distance = htonl (ntohl (target->distance) + 1);
1091 send_distance_change_to_plugin (&target->peer, ntohl (target->distance) + 1);
1095 if (ntohl (current_route->target.distance) >= ntohl (target->distance) + 1)
1097 /* alternative, shorter route exists, ignore */
1100 /* new route is better than the existing one, take over! */
1101 /* NOTE: minor security issue: malicious peers may advertise
1102 very short routes to take over longer paths; as we don't
1103 check that the shorter routes actually work, a malicious
1104 direct neighbor can use this to DoS our long routes */
1105 current_route->next_hop = neighbor;
1106 current_route->target.distance = htonl (ntohl (target->distance) + 1);
1107 send_distance_change_to_plugin (&target->peer, ntohl (target->distance) + 1);
1111 current_route = GNUNET_malloc (sizeof (struct Route));
1112 current_route->next_hop = neighbor;
1113 current_route->target.peer = target->peer;
1114 current_route->target.distance = htonl (ntohl (target->distance) + 1);
1115 GNUNET_assert (GNUNET_YES ==
1116 GNUNET_CONTAINER_multihashmap_put (all_routes,
1117 ¤t_route->target.peer.hashPubKey,
1119 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
1120 send_connect_to_plugin (¤t_route->target.peer,
1121 ntohl (current_route->target.distance));
1128 * The consensus has concluded, clean up and schedule the next one.
1130 * @param cls the 'struct GNUNET_DirectNeighbor' with which we created the consensus
1133 consensus_done_cb (void *cls)
1135 struct DirectNeighbor *neighbor = cls;
1137 GNUNET_CONSENSUS_destroy (neighbor->consensus);
1138 neighbor->consensus = NULL;
1139 /* remove targets that disappeared */
1140 neighbor->target_removed = GNUNET_NO;
1141 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table,
1142 &check_target_removed,
1144 if (GNUNET_YES == neighbor->target_removed)
1146 /* check if we got an alternative for the removed routes */
1147 GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
1151 /* add targets that appeared (and check for improved routes) */
1152 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table_consensus,
1153 &check_target_added,
1155 if (NULL != neighbor->neighbor_table)
1157 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table,
1160 GNUNET_CONTAINER_multihashmap_destroy (neighbor->neighbor_table);
1161 neighbor->neighbor_table = NULL;
1163 neighbor->neighbor_table = neighbor->neighbor_table_consensus;
1164 neighbor->neighbor_table_consensus = NULL;
1165 neighbor->consensus_task = GNUNET_SCHEDULER_add_delayed (GNUNET_DV_CONSENSUS_FREQUENCY,
1172 * We inserted the last element into the consensus, get ready to
1173 * insert the next element into the consensus or conclude if
1176 * @param cls the 'struct DirectNeighbor' of the peer we're building
1177 * a routing consensus with
1178 * @param success GNUNET_OK if the last element was added successfully,
1179 * GNUNET_SYSERR if we failed
1182 insert_next_element (void *cls,
1185 struct DirectNeighbor *neighbor = cls;
1186 struct GNUNET_CONSENSUS_Element element;
1188 while ( (DEFAULT_FISHEYE_DEPTH - 1 > neighbor->consensus_insertion_distance) &&
1189 (consensi[neighbor->consensus_insertion_distance].array_length == neighbor->consensus_insertion_offset) )
1191 neighbor->consensus_insertion_offset = 0;
1192 neighbor->consensus_insertion_distance++;
1193 /* skip over NULL entries */
1194 while ( (DEFAULT_FISHEYE_DEPTH - 1 > neighbor->consensus_insertion_distance) &&
1195 (consensi[neighbor->consensus_insertion_distance].array_length < neighbor->consensus_insertion_offset) &&
1196 (NULL == consensi[neighbor->consensus_insertion_distance].targets[neighbor->consensus_insertion_offset]) )
1197 neighbor->consensus_insertion_offset++;
1199 if (DEFAULT_FISHEYE_DEPTH - 1 == neighbor->consensus_insertion_distance)
1201 /* we're done, conclude! */
1202 GNUNET_CONSENSUS_conclude (neighbor->consensus,
1203 GNUNET_DV_CONSENSUS_FREQUENCY,
1208 element.size = sizeof (struct Target);
1209 element.data = &consensi[neighbor->consensus_insertion_distance].targets[neighbor->consensus_insertion_offset++]->target;
1211 /* skip over NULL entries */
1212 while ( (DEFAULT_FISHEYE_DEPTH - 1 > neighbor->consensus_insertion_distance) &&
1213 (consensi[neighbor->consensus_insertion_distance].array_length < neighbor->consensus_insertion_offset) &&
1214 (NULL == consensi[neighbor->consensus_insertion_distance].targets[neighbor->consensus_insertion_offset]) )
1215 neighbor->consensus_insertion_offset++;
1216 GNUNET_CONSENSUS_insert (neighbor->consensus,
1218 &insert_next_element,
1224 * We have learned a new route from the other peer. Add it to the
1225 * route set we're building.
1227 * @param cls the 'struct DirectNeighbor' we're building the consensus with
1228 * @param element the new element we have learned
1229 * @return GNUNET_OK if the valid is well-formed and should be added to the consensus,
1230 * GNUNET_SYSERR if the element should be ignored and not be propagated
1233 learn_route_cb (void *cls,
1234 const struct GNUNET_CONSENSUS_Element *element)
1236 struct DirectNeighbor *neighbor = cls;
1237 struct Target *target;
1239 if (NULL == element)
1241 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1242 "Failed to establish DV consensus, will try again later\n");
1243 GNUNET_CONSENSUS_destroy (neighbor->consensus);
1244 if (NULL != neighbor->neighbor_table_consensus)
1246 GNUNET_CONTAINER_multihashmap_iterate (neighbor->neighbor_table_consensus,
1249 GNUNET_CONTAINER_multihashmap_destroy (neighbor->neighbor_table_consensus);
1250 neighbor->neighbor_table_consensus = NULL;
1252 neighbor->consensus = NULL;
1253 neighbor->consensus_task = GNUNET_SCHEDULER_add_delayed (GNUNET_DV_CONSENSUS_FREQUENCY,
1256 return GNUNET_SYSERR;
1258 if (sizeof (struct Target) != element->size)
1260 GNUNET_break_op (0);
1261 return GNUNET_SYSERR;
1263 target = GNUNET_malloc (sizeof (struct Target));
1264 memcpy (target, element->data, sizeof (struct Target));
1266 GNUNET_CONTAINER_multihashmap_put (neighbor->neighbor_table_consensus,
1267 &target->peer.hashPubKey,
1269 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
1271 GNUNET_break_op (0);
1272 GNUNET_free (target);
1273 return GNUNET_SYSERR;
1280 * Start creating a new consensus from scratch.
1282 * @param cls the 'struct DirectNeighbor' of the peer we're building
1283 * a routing consensus with
1284 * @param tc scheduler context
1287 start_consensus (void *cls,
1288 const struct GNUNET_SCHEDULER_TaskContext *tc)
1290 struct DirectNeighbor *neighbor = cls;
1291 struct GNUNET_HashCode session_id;
1292 struct GNUNET_HashCode real_session_id;
1294 neighbor->consensus_task = GNUNET_SCHEDULER_NO_TASK;
1295 neighbor->consensus_insertion_offset = 0;
1296 neighbor->consensus_insertion_distance = 0;
1297 GNUNET_assert (NULL == neighbor->neighbor_table_consensus);
1298 GNUNET_assert (NULL == neighbor->consensus);
1299 neighbor->neighbor_table_consensus = GNUNET_CONTAINER_multihashmap_create (1024, GNUNET_YES);
1300 /* construct session ID seed as XOR of both peer's identities */
1301 GNUNET_CRYPTO_hash_xor (&my_identity.hashPubKey,
1302 &neighbor->peer.hashPubKey,
1304 /* make sure session ID is unique across applications by salting it with 'DV' */
1305 GNUNET_CRYPTO_hkdf (&real_session_id, sizeof (real_session_id),
1306 GCRY_MD_SHA512, GCRY_MD_SHA256,
1308 &session_id, sizeof (session_id),
1310 neighbor->consensus = GNUNET_CONSENSUS_create (cfg,
1316 if (NULL == neighbor->consensus)
1318 neighbor->consensus_task = GNUNET_SCHEDULER_add_delayed (GNUNET_DV_CONSENSUS_FREQUENCY,
1323 insert_next_element (neighbor, GNUNET_OK);
1328 * Core handler for DV data messages. Whatever this message
1329 * contains all we really have to do is rip it out of its
1330 * DV layering and give it to our pal the DV plugin to report
1333 * @param cls closure
1334 * @param peer peer which sent the message (immediate sender)
1335 * @param message the message
1336 * @return GNUNET_OK on success, GNUNET_SYSERR if the other peer violated the protocol
1339 handle_dv_route_message (void *cls, const struct GNUNET_PeerIdentity *peer,
1340 const struct GNUNET_MessageHeader *message)
1342 const struct RouteMessage *rm;
1343 const struct GNUNET_MessageHeader *payload;
1344 struct Route *route;
1346 if (ntohs (message->size) < sizeof (struct RouteMessage) + sizeof (struct GNUNET_MessageHeader))
1348 GNUNET_break_op (0);
1349 return GNUNET_SYSERR;
1351 rm = (const struct RouteMessage *) message;
1352 payload = (const struct GNUNET_MessageHeader *) &rm[1];
1353 if (ntohs (message->size) != sizeof (struct RouteMessage) + ntohs (payload->size))
1355 GNUNET_break_op (0);
1356 return GNUNET_SYSERR;
1358 if (0 == memcmp (&rm->target,
1360 sizeof (struct GNUNET_PeerIdentity)))
1362 /* message is for me, check reverse route! */
1363 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
1364 &rm->sender.hashPubKey);
1367 /* don't have reverse route, drop */
1368 GNUNET_STATISTICS_update (stats,
1369 "# message discarded (no reverse route)",
1373 send_data_to_plugin (payload,
1375 ntohl (route->target.distance));
1378 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
1379 &rm->target.hashPubKey);
1382 GNUNET_STATISTICS_update (stats,
1383 "# messages discarded (no route)",
1387 if (ntohl (route->target.distance) > ntohl (rm->distance) + 1)
1389 GNUNET_STATISTICS_update (stats,
1390 "# messages discarded (target too far)",
1394 forward_payload (route->next_hop,
1395 ntohl (route->target.distance),
1405 * Service server's handler for message send requests (which come
1406 * bubbling up to us through the DV plugin).
1408 * @param cls closure
1409 * @param client identification of the client
1410 * @param message the actual message
1413 handle_dv_send_message (void *cls, struct GNUNET_SERVER_Client *client,
1414 const struct GNUNET_MessageHeader *message)
1416 struct Route *route;
1417 const struct GNUNET_DV_SendMessage *msg;
1418 const struct GNUNET_MessageHeader *payload;
1420 if (ntohs (message->size) < sizeof (struct GNUNET_DV_SendMessage) + sizeof (struct GNUNET_MessageHeader))
1423 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1426 msg = (const struct GNUNET_DV_SendMessage *) message;
1427 GNUNET_break (0 != ntohl (msg->uid));
1428 payload = (const struct GNUNET_MessageHeader *) &msg[1];
1429 if (ntohs (message->size) != sizeof (struct GNUNET_DV_SendMessage) + ntohs (payload->size))
1432 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
1435 route = GNUNET_CONTAINER_multihashmap_get (all_routes,
1436 &msg->target.hashPubKey);
1439 /* got disconnected */
1440 GNUNET_STATISTICS_update (stats,
1441 "# local messages discarded (no route)",
1443 send_ack_to_plugin (&msg->target, ntohl (msg->uid), GNUNET_YES);
1444 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1447 forward_payload (route->next_hop,
1448 ntohl (route->target.distance),
1453 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1458 * Cleanup all of the data structures associated with a given neighbor.
1460 * @param neighbor neighbor to clean up
1463 cleanup_neighbor (struct DirectNeighbor *neighbor)
1465 struct PendingMessage *pending;
1467 while (NULL != (pending = neighbor->pm_head))
1469 neighbor->pm_queue_size--;
1470 GNUNET_CONTAINER_DLL_remove (neighbor->pm_head,
1473 GNUNET_free (pending);
1475 handle_direct_disconnect (neighbor);
1476 GNUNET_assert (GNUNET_YES ==
1477 GNUNET_CONTAINER_multihashmap_remove (direct_neighbors,
1478 &neighbor->peer.hashPubKey,
1480 GNUNET_free (neighbor);
1485 * Method called whenever a given peer disconnects.
1487 * @param cls closure
1488 * @param peer peer identity this notification is about
1491 handle_core_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer)
1493 struct DirectNeighbor *neighbor;
1495 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1496 "Received core peer disconnect message for peer `%s'!\n",
1498 /* Check for disconnect from self message */
1499 if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
1502 GNUNET_CONTAINER_multihashmap_get (direct_neighbors, &peer->hashPubKey);
1503 if (NULL == neighbor)
1508 GNUNET_break (GNUNET_YES == neighbor->connected);
1509 neighbor->connected = GNUNET_NO;
1510 if (DIRECT_NEIGHBOR_COST == neighbor->distance)
1512 GNUNET_STATISTICS_update (stats,
1513 "# peers connected (1-hop)",
1516 cleanup_neighbor (neighbor);
1517 GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
1524 * Multihashmap iterator for freeing routes. Should never be called.
1527 * @param key key value stored under
1528 * @param value the route to be freed
1530 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
1533 free_route (void *cls, const struct GNUNET_HashCode * key, void *value)
1535 struct Route *route = value;
1538 GNUNET_assert (GNUNET_YES ==
1539 GNUNET_CONTAINER_multihashmap_remove (all_routes, key, value));
1540 release_route (route);
1541 send_disconnect_to_plugin (&route->target.peer);
1542 GNUNET_free (route);
1548 * Multihashmap iterator for freeing direct neighbors. Should never be called.
1551 * @param key key value stored under
1552 * @param value the direct neighbor to be freed
1554 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
1557 free_direct_neighbors (void *cls, const struct GNUNET_HashCode * key, void *value)
1559 struct DirectNeighbor *neighbor = value;
1562 cleanup_neighbor (neighbor);
1568 * Task run during shutdown.
1574 shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1578 GNUNET_CORE_disconnect (core_api);
1580 GNUNET_ATS_performance_done (ats);
1582 GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
1583 &free_direct_neighbors, NULL);
1584 GNUNET_CONTAINER_multihashmap_iterate (all_routes,
1586 GNUNET_CONTAINER_multihashmap_destroy (direct_neighbors);
1587 GNUNET_CONTAINER_multihashmap_destroy (all_routes);
1588 GNUNET_STATISTICS_destroy (stats, GNUNET_NO);
1590 GNUNET_SERVER_notification_context_destroy (nc);
1592 for (i=0;i<DEFAULT_FISHEYE_DEPTH - 1;i++)
1593 GNUNET_array_grow (consensi[i].targets,
1594 consensi[i].array_length,
1600 * Notify newly connected client about an existing route.
1602 * @param cls the 'struct GNUNET_SERVER_Client'
1603 * @param key peer identity
1604 * @param value the XXX.
1605 * @return GNUNET_OK (continue to iterate)
1608 add_route (void *cls,
1609 const struct GNUNET_HashCode *key,
1612 struct GNUNET_SERVER_Client *client = cls;
1613 struct Route *route = value;
1614 struct GNUNET_DV_ConnectMessage cm;
1616 cm.header.size = htons (sizeof (cm));
1617 cm.header.type = htons (GNUNET_MESSAGE_TYPE_DV_CONNECT);
1618 cm.distance = htonl (route->target.distance);
1619 cm.peer = route->target.peer;
1621 GNUNET_SERVER_notification_context_unicast (nc,
1630 * Handle START-message. This is the first message sent to us
1631 * by the client (can only be one!).
1633 * @param cls closure (always NULL)
1634 * @param client identification of the client
1635 * @param message the actual message
1638 handle_start (void *cls, struct GNUNET_SERVER_Client *client,
1639 const struct GNUNET_MessageHeader *message)
1641 GNUNET_SERVER_notification_context_add (nc, client);
1642 GNUNET_SERVER_receive_done (client, GNUNET_OK);
1643 GNUNET_CONTAINER_multihashmap_iterate (all_routes,
1650 * Called on core init.
1653 * @param server legacy
1654 * @param identity this peer's identity
1657 core_init (void *cls, struct GNUNET_CORE_Handle *server,
1658 const struct GNUNET_PeerIdentity *identity)
1660 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1662 GNUNET_i2s (identity));
1663 my_identity = *identity;
1668 * Process dv requests.
1670 * @param cls closure
1671 * @param server the initialized server
1672 * @param c configuration to use
1675 run (void *cls, struct GNUNET_SERVER_Handle *server,
1676 const struct GNUNET_CONFIGURATION_Handle *c)
1678 static struct GNUNET_CORE_MessageHandler core_handlers[] = {
1679 {&handle_dv_route_message, GNUNET_MESSAGE_TYPE_DV_ROUTE, 0},
1682 static struct GNUNET_SERVER_MessageHandler plugin_handlers[] = {
1683 {&handle_start, NULL,
1684 GNUNET_MESSAGE_TYPE_DV_START,
1685 sizeof (struct GNUNET_MessageHeader) },
1686 { &handle_dv_send_message, NULL,
1687 GNUNET_MESSAGE_TYPE_DV_SEND,
1693 direct_neighbors = GNUNET_CONTAINER_multihashmap_create (128, GNUNET_NO);
1694 all_routes = GNUNET_CONTAINER_multihashmap_create (65536, GNUNET_NO);
1695 core_api = GNUNET_CORE_connect (cfg, NULL,
1697 &handle_core_connect,
1698 &handle_core_disconnect,
1703 if (NULL == core_api)
1705 ats = GNUNET_ATS_performance_init (cfg, &handle_ats_update, NULL);
1708 GNUNET_CORE_disconnect (core_api);
1711 nc = GNUNET_SERVER_notification_context_create (server,
1712 MAX_QUEUE_SIZE_PLUGIN);
1713 stats = GNUNET_STATISTICS_create ("dv", cfg);
1714 GNUNET_SERVER_add_handlers (server, plugin_handlers);
1715 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
1716 &shutdown_task, NULL);
1721 * The main function for the dv service.
1723 * @param argc number of arguments from the command line
1724 * @param argv command line arguments
1725 * @return 0 ok, 1 on error
1728 main (int argc, char *const *argv)
1730 return (GNUNET_OK ==
1731 GNUNET_SERVICE_run (argc, argv, "dv", GNUNET_SERVICE_OPTION_NONE,
1732 &run, NULL)) ? 0 : 1;
1735 /* end of gnunet-service-dv.c */