2 This file is part of GNUnet.
3 (C) 2001-2013 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
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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.
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17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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22 * @file mesh/gnunet-service-mesh_connection.c
23 * @brief GNUnet MESH service connection handling
24 * @author Bartlomiej Polot
28 #include "gnunet_util_lib.h"
30 #include "gnunet_statistics_service.h"
32 #include "mesh_path.h"
33 #include "mesh_protocol_enc.h"
35 #include "gnunet-service-mesh_connection.h"
36 #include "gnunet-service-mesh_peer.h"
37 #include "gnunet-service-mesh_tunnel.h"
38 #include "gnunet-service-mesh_channel.h"
41 #define LOG(level, ...) GNUNET_log_from (level,"mesh-con",__VA_ARGS__)
43 #define MESH_MAX_POLL_TIME GNUNET_TIME_relative_multiply (\
44 GNUNET_TIME_UNIT_MINUTES,\
49 /******************************************************************************/
50 /******************************** STRUCTS **********************************/
51 /******************************************************************************/
54 * Struct to encapsulate all the Flow Control information to a peer to which
55 * we are directly connected (on a core level).
57 struct MeshFlowControl
60 * Connection this controls.
62 struct MeshConnection *c;
65 * How many messages are in the queue on this connection.
70 * How many messages do we accept in the queue.
72 unsigned int queue_max;
80 * ID of the last packet sent towards the peer.
82 uint32_t last_pid_sent;
85 * ID of the last packet received from the peer.
87 uint32_t last_pid_recv;
90 * Last ACK sent to the peer (peer can't send more than this PID).
92 uint32_t last_ack_sent;
95 * Last ACK sent towards the origin (for traffic towards leaf node).
97 uint32_t last_ack_recv;
100 * Task to poll the peer in case of a lost ACK causes stall.
102 GNUNET_SCHEDULER_TaskIdentifier poll_task;
105 * How frequently to poll for ACKs.
107 struct GNUNET_TIME_Relative poll_time;
111 * Keep a record of the last messages sent on this connection.
113 struct MeshConnectionPerformance
116 * Circular buffer for storing measurements.
118 double usecsperbyte[AVG_MSGS];
121 * Running average of @c usecsperbyte.
126 * How many values of @c usecsperbyte are valid.
131 * Index of the next "free" position in @c usecsperbyte.
138 * Struct containing all information regarding a connection to a peer.
140 struct MeshConnection
143 * Tunnel this connection is part of.
145 struct MeshTunnel3 *t;
148 * Flow control information for traffic fwd.
150 struct MeshFlowControl fwd_fc;
153 * Flow control information for traffic bck.
155 struct MeshFlowControl bck_fc;
158 * Measure connection performance on the endpoint.
160 struct MeshConnectionPerformance *perf;
163 * ID of the connection.
165 struct GNUNET_HashCode id;
168 * State of the connection.
170 enum MeshConnectionState state;
173 * Path being used for the tunnel.
175 struct MeshPeerPath *path;
178 * Position of the local peer in the path.
180 unsigned int own_pos;
183 * Task to keep the used paths alive at the owner,
184 * time tunnel out on all the other peers.
186 GNUNET_SCHEDULER_TaskIdentifier fwd_maintenance_task;
189 * Task to keep the used paths alive at the destination,
190 * time tunnel out on all the other peers.
192 GNUNET_SCHEDULER_TaskIdentifier bck_maintenance_task;
195 * Pending message count.
197 int pending_messages;
200 * Destroy flag: if true, destroy on last message.
205 /******************************************************************************/
206 /******************************* GLOBALS ***********************************/
207 /******************************************************************************/
210 * Global handle to the statistics service.
212 extern struct GNUNET_STATISTICS_Handle *stats;
215 * Local peer own ID (memory efficient handle).
217 extern GNUNET_PEER_Id myid;
220 * Local peer own ID (full value).
222 extern struct GNUNET_PeerIdentity my_full_id;
225 * Connections known, indexed by cid (MeshConnection).
227 static struct GNUNET_CONTAINER_MultiHashMap *connections;
230 * How many connections are we willing to maintain.
231 * Local connections are always allowed, even if there are more connections than max.
233 static unsigned long long max_connections;
236 * How many messages *in total* are we willing to queue, divide by number of
237 * connections to get connection queue size.
239 static unsigned long long max_msgs_queue;
242 * How often to send path keepalives. Paths timeout after 4 missed.
244 static struct GNUNET_TIME_Relative refresh_connection_time;
247 /******************************************************************************/
248 /******************************** STATIC ***********************************/
249 /******************************************************************************/
251 #if 0 // avoid compiler warning for unused static function
253 fc_debug (struct MeshFlowControl *fc)
255 LOG (GNUNET_ERROR_TYPE_DEBUG, " IN: %u/%u\n",
256 fc->last_pid_recv, fc->last_ack_sent);
257 LOG (GNUNET_ERROR_TYPE_DEBUG, " OUT: %u/%u\n",
258 fc->last_pid_sent, fc->last_ack_recv);
259 LOG (GNUNET_ERROR_TYPE_DEBUG, " QUEUE: %u/%u\n",
260 fc->queue_n, fc->queue_max);
264 connection_debug (struct MeshConnection *c)
268 LOG (GNUNET_ERROR_TYPE_DEBUG, "*** DEBUG NULL CONNECTION ***\n");
271 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s:%X\n",
272 peer2s (c->t->peer), GMC_2s (c));
273 LOG (GNUNET_ERROR_TYPE_DEBUG, " state: %u, pending msgs: %u\n",
274 c->state, c->pending_messages);
275 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD FC\n");
276 fc_debug (&c->fwd_fc);
277 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK FC\n");
278 fc_debug (&c->bck_fc);
283 * Get string description for tunnel state.
285 * @param s Tunnel state.
287 * @return String representation.
290 GMC_state2s (enum MeshConnectionState s)
294 case MESH_CONNECTION_NEW:
295 return "MESH_CONNECTION_NEW";
296 case MESH_CONNECTION_SENT:
297 return "MESH_CONNECTION_SENT";
298 case MESH_CONNECTION_ACK:
299 return "MESH_CONNECTION_ACK";
300 case MESH_CONNECTION_READY:
301 return "MESH_CONNECTION_READY";
303 return "MESH_CONNECTION_STATE_ERROR";
309 * Initialize a Flow Control structure to the initial state.
311 * @param fc Flow Control structure to initialize.
314 fc_init (struct MeshFlowControl *fc)
317 fc->last_pid_sent = (uint32_t) -1; /* Next (expected) = 0 */
318 fc->last_pid_recv = (uint32_t) -1;
319 fc->last_ack_sent = (uint32_t) 0;
320 fc->last_ack_recv = (uint32_t) 0;
321 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
322 fc->poll_time = GNUNET_TIME_UNIT_SECONDS;
324 fc->queue_max = (max_msgs_queue / max_connections) + 1;
331 * @param cid Connection ID.
333 static struct MeshConnection *
334 connection_get (const struct GNUNET_HashCode *cid)
336 return GNUNET_CONTAINER_multihashmap_get (connections, cid);
341 connection_change_state (struct MeshConnection* c,
342 enum MeshConnectionState state)
344 LOG (GNUNET_ERROR_TYPE_DEBUG,
345 "Connection %s state was %s\n",
346 GMC_2s (c), GMC_state2s (c->state));
347 LOG (GNUNET_ERROR_TYPE_DEBUG,
348 "Connection %s state is now %s\n",
349 GMC_2s (c), GMC_state2s (state));
355 * Send an ACK on the connection, informing the predecessor about
356 * the available buffer space. Should not be called in case the peer
357 * is origin (no predecessor).
359 * Note that for fwd ack, the FWD mean forward *traffic* (root->dest),
360 * the ACK itself goes "back" (dest->root).
362 * @param c Connection on which to send the ACK.
363 * @param buffer How much space free to advertise?
364 * @param fwd Is this FWD ACK? (Going dest->owner)
367 send_ack (struct MeshConnection *c, unsigned int buffer, int fwd)
369 struct MeshFlowControl *next_fc;
370 struct MeshFlowControl *prev_fc;
371 struct GNUNET_MESH_ACK msg;
375 /* If origin, there is no connection to send ACKs. Wrong function! */
376 if (GMC_is_origin (c, fwd))
382 next_fc = fwd ? &c->fwd_fc : &c->bck_fc;
383 prev_fc = fwd ? &c->bck_fc : &c->fwd_fc;
385 LOG (GNUNET_ERROR_TYPE_DEBUG,
386 "connection send %s ack on %s\n",
387 fwd ? "FWD" : "BCK", GMC_2s (c));
389 /* Check if we need to transmit the ACK */
390 delta = prev_fc->last_ack_sent - prev_fc->last_pid_recv;
391 if (3 < delta && buffer < delta)
393 LOG (GNUNET_ERROR_TYPE_DEBUG, "Not sending ACK, buffer > 3\n");
394 LOG (GNUNET_ERROR_TYPE_DEBUG,
395 " last pid recv: %u, last ack sent: %u\n",
396 prev_fc->last_pid_recv, prev_fc->last_ack_sent);
400 /* Ok, ACK might be necessary, what PID to ACK? */
401 ack = prev_fc->last_pid_recv + buffer;
402 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK %u\n", ack);
403 LOG (GNUNET_ERROR_TYPE_DEBUG,
404 " last pid %u, last ack %u, qmax %u, q %u\n",
405 prev_fc->last_pid_recv, prev_fc->last_ack_sent,
406 next_fc->queue_max, next_fc->queue_n);
407 if (ack == prev_fc->last_ack_sent)
409 LOG (GNUNET_ERROR_TYPE_DEBUG, "Not sending FWD ACK, not needed\n");
413 prev_fc->last_ack_sent = ack;
415 /* Build ACK message and send on connection */
416 msg.header.size = htons (sizeof (msg));
417 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_ACK);
418 msg.ack = htonl (ack);
421 GMC_send_prebuilt_message (&msg.header, c, NULL, !fwd);
426 * Callback called when a queued message is sent.
428 * Calculates the average time and connection packet tracking.
430 * @param cls Closure.
431 * @param c Connection this message was on.
432 * @param type Type of message sent.
433 * @param fwd Was this a FWD going message?
434 * @param size Size of the message.
435 * @param wait Time spent waiting for core (only the time for THIS message)
438 message_sent (void *cls,
439 struct MeshConnection *c, uint16_t type,
440 int fwd, size_t size,
441 struct GNUNET_TIME_Relative wait)
443 struct MeshConnectionPerformance *p;
444 struct MeshFlowControl *fc;
447 fc = fwd ? &c->fwd_fc : &c->bck_fc;
448 LOG (GNUNET_ERROR_TYPE_DEBUG, "! sent %s\n", GNUNET_MESH_DEBUG_M2S (type));
449 LOG (GNUNET_ERROR_TYPE_DEBUG, "! Q_N- %p %u\n", fc, fc->queue_n);
450 c->pending_messages--;
451 if (GNUNET_YES == c->destroy && 0 == c->pending_messages)
453 LOG (GNUNET_ERROR_TYPE_DEBUG, "! destroying connection!\n");
457 /* Send ACK if needed, after accounting for sent ID in fc->queue_n */
460 case GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED:
463 LOG (GNUNET_ERROR_TYPE_DEBUG,
464 "! accounting pid %u\n",
466 GMC_send_ack (c, fwd);
471 LOG (GNUNET_ERROR_TYPE_DEBUG, "! message sent!\n");
474 return; /* Only endpoints are interested in timing. */
477 usecsperbyte = ((double) wait.rel_value_us) / size;
478 if (p->size == AVG_MSGS)
480 /* Array is full. Substract oldest value, add new one and store. */
481 p->avg -= (p->usecsperbyte[p->idx] / AVG_MSGS);
482 p->usecsperbyte[p->idx] = usecsperbyte;
483 p->avg += (p->usecsperbyte[p->idx] / AVG_MSGS);
487 /* Array not yet full. Add current value to avg and store. */
488 p->usecsperbyte[p->idx] = usecsperbyte;
490 p->avg += p->usecsperbyte[p->idx];
494 p->idx = (p->idx + 1) % AVG_MSGS;
498 // c->t->pending_messages--;
499 // if (GNUNET_YES == c->t->destroy && 0 == t->pending_messages)
501 // LOG (GNUNET_ERROR_TYPE_DEBUG, "* destroying tunnel!\n");
502 // GMT_destroy (c->t);
509 * Get the previous hop in a connection
511 * @param c Connection.
513 * @return Previous peer in the connection.
515 static struct MeshPeer *
516 get_prev_hop (const struct MeshConnection *c)
520 if (0 == c->own_pos || c->path->length < 2)
521 id = c->path->peers[0];
523 id = c->path->peers[c->own_pos - 1];
525 return GMP_get_short (id);
530 * Get the next hop in a connection
532 * @param c Connection.
534 * @return Next peer in the connection.
536 static struct MeshPeer *
537 get_next_hop (const struct MeshConnection *c)
541 if ((c->path->length - 1) == c->own_pos || c->path->length < 2)
542 id = c->path->peers[c->path->length - 1];
544 id = c->path->peers[c->own_pos + 1];
546 return GMP_get_short (id);
551 * Get the hop in a connection.
553 * @param c Connection.
554 * @param fwd Next hop?
556 * @return Next peer in the connection.
558 static struct MeshPeer *
559 get_hop (struct MeshConnection *c, int fwd)
562 return get_next_hop (c);
563 return get_prev_hop (c);
568 * Is traffic coming from this sender 'FWD' traffic?
570 * @param c Connection to check.
571 * @param sender Peer identity of neighbor.
573 * @return GNUNET_YES in case the sender is the 'prev' hop and therefore
574 * the traffic is 'FWD'. GNUNET_NO for BCK. GNUNET_SYSERR for errors.
577 is_fwd (const struct MeshConnection *c,
578 const struct GNUNET_PeerIdentity *sender)
582 id = GNUNET_PEER_search (sender);
583 if (GMP_get_short_id (get_prev_hop (c)) == id)
586 if (GMP_get_short_id (get_next_hop (c)) == id)
590 return GNUNET_SYSERR;
595 * Sends a CONNECTION ACK message in reponse to a received CONNECTION_CREATE
596 * or a first CONNECTION_ACK directed to us.
598 * @param connection Connection to confirm.
599 * @param fwd Should we send it FWD?
600 * (First (~SYNACK) goes BCK, second (~ACK) goes FWD)
603 send_connection_ack (struct MeshConnection *connection, int fwd)
605 struct MeshTunnel3 *t;
608 LOG (GNUNET_ERROR_TYPE_DEBUG, "Send connection ack\n");
609 GMP_queue_add (get_hop (connection, fwd), NULL,
610 GNUNET_MESSAGE_TYPE_MESH_CONNECTION_ACK,
611 sizeof (struct GNUNET_MESH_ConnectionACK),
612 connection, NULL, fwd,
613 &message_sent, NULL);
614 if (MESH_TUNNEL3_NEW == GMT_get_state (t))
615 GMT_change_state (t, MESH_TUNNEL3_WAITING);
616 if (MESH_CONNECTION_READY != connection->state)
617 connection_change_state (connection, MESH_CONNECTION_SENT);
622 * Send a notification that a connection is broken.
624 * @param c Connection that is broken.
625 * @param id1 Peer that has disconnected.
626 * @param id2 Peer that has disconnected.
627 * @param fwd Direction towards which to send it.
630 send_broken (struct MeshConnection *c,
631 const struct GNUNET_PeerIdentity *id1,
632 const struct GNUNET_PeerIdentity *id2,
635 struct GNUNET_MESH_ConnectionBroken msg;
637 msg.header.size = htons (sizeof (struct GNUNET_MESH_ConnectionBroken));
638 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CONNECTION_BROKEN);
642 GMC_send_prebuilt_message (&msg.header, c, NULL, fwd);
648 * Send keepalive packets for a connection.
650 * @param c Connection to keep alive..
651 * @param fwd Is this a FWD keepalive? (owner -> dest).
654 connection_keepalive (struct MeshConnection *c, int fwd)
656 struct GNUNET_MESH_ConnectionKeepAlive *msg;
657 size_t size = sizeof (struct GNUNET_MESH_ConnectionKeepAlive);
661 type = fwd ? GNUNET_MESSAGE_TYPE_MESH_FWD_KEEPALIVE :
662 GNUNET_MESSAGE_TYPE_MESH_BCK_KEEPALIVE;
664 LOG (GNUNET_ERROR_TYPE_DEBUG,
665 "sending %s keepalive for connection %s]\n",
666 fwd ? "FWD" : "BCK", GMC_2s (c));
668 msg = (struct GNUNET_MESH_ConnectionKeepAlive *) cbuf;
669 msg->header.size = htons (size);
670 msg->header.type = htons (type);
673 GMC_send_prebuilt_message (&msg->header, c, NULL, fwd);
678 * Send CONNECTION_{CREATE/ACK} packets for a connection.
680 * @param c Connection for which to send the message.
681 * @param fwd If GNUNET_YES, send CREATE, otherwise send ACK.
684 connection_recreate (struct MeshConnection *c, int fwd)
686 LOG (GNUNET_ERROR_TYPE_DEBUG, "sending connection recreate\n");
690 send_connection_ack (c, GNUNET_NO);
695 * Generic connection timer management.
696 * Depending on the role of the peer in the connection will send the
697 * appropriate message (build or keepalive)
699 * @param c Conncetion to maintain.
703 connection_maintain (struct MeshConnection *c, int fwd)
705 if (MESH_TUNNEL3_SEARCHING == GMT_get_state (c->t))
707 /* TODO DHT GET with RO_BART */
712 case MESH_CONNECTION_NEW:
714 case MESH_CONNECTION_SENT:
715 connection_recreate (c, fwd);
717 case MESH_CONNECTION_READY:
718 connection_keepalive (c, fwd);
727 connection_fwd_keepalive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
729 struct MeshConnection *c = cls;
731 c->fwd_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
732 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
735 connection_maintain (c, GNUNET_YES);
736 c->fwd_maintenance_task = GNUNET_SCHEDULER_add_delayed (refresh_connection_time,
737 &connection_fwd_keepalive,
743 connection_bck_keepalive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
745 struct MeshConnection *c = cls;
747 c->bck_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
748 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
751 connection_maintain (c, GNUNET_NO);
752 c->bck_maintenance_task = GNUNET_SCHEDULER_add_delayed (refresh_connection_time,
753 &connection_bck_keepalive,
759 * @brief Re-initiate traffic on this connection if necessary.
761 * Check if there is traffic queued towards this peer
762 * and the core transmit handle is NULL (traffic was stalled).
763 * If so, call core tmt rdy.
765 * @param c Connection on which initiate traffic.
766 * @param fwd Is this about fwd traffic?
769 connection_unlock_queue (struct MeshConnection *c, int fwd)
771 struct MeshPeer *peer;
773 LOG (GNUNET_ERROR_TYPE_DEBUG,
774 "connection_unlock_queue %s on %s\n",
775 fwd ? "FWD" : "BCK", GMC_2s (c));
777 if (GMC_is_terminal (c, fwd))
779 LOG (GNUNET_ERROR_TYPE_DEBUG, " is terminal!\n");
783 peer = get_hop (c, fwd);
784 GMP_queue_unlock (peer, c);
789 * Cancel all transmissions that belong to a certain connection.
791 * @param c Connection which to cancel.
792 * @param fwd Cancel fwd traffic?
795 connection_cancel_queues (struct MeshConnection *c, int fwd)
798 struct MeshFlowControl *fc;
799 struct MeshPeer *peer;
807 fc = fwd ? &c->fwd_fc : &c->bck_fc;
808 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task)
810 GNUNET_SCHEDULER_cancel (fc->poll_task);
811 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
813 peer = get_hop (c, fwd);
814 GMP_queue_cancel (peer, c);
819 * Function called if a connection has been stalled for a while,
820 * possibly due to a missed ACK. Poll the neighbor about its ACK status.
822 * @param cls Closure (poll ctx).
823 * @param tc TaskContext.
826 connection_poll (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
828 struct MeshFlowControl *fc = cls;
829 struct GNUNET_MESH_Poll msg;
830 struct MeshConnection *c;
832 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
833 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
839 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** Polling!\n");
840 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** connection [%s]\n", GMC_2s (c));
841 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** %s\n",
842 fc == &c->fwd_fc ? "FWD" : "BCK");
844 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_POLL);
845 msg.header.size = htons (sizeof (msg));
846 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** pid (%u)!\n", fc->last_pid_sent);
847 GMC_send_prebuilt_message (&msg.header, c, NULL, fc == &c->fwd_fc);
848 fc->poll_time = GNUNET_TIME_STD_BACKOFF (fc->poll_time);
849 fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time,
850 &connection_poll, fc);
855 * Timeout function due to lack of keepalive/traffic from the owner.
856 * Destroys connection if called.
858 * @param cls Closure (connection to destroy).
859 * @param tc TaskContext.
862 connection_fwd_timeout (void *cls,
863 const struct GNUNET_SCHEDULER_TaskContext *tc)
865 struct MeshConnection *c = cls;
867 c->fwd_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
868 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
870 LOG (GNUNET_ERROR_TYPE_DEBUG,
871 "Connection %s[%X] FWD timed out. Destroying.\n",
875 if (GMC_is_origin (c, GNUNET_YES)) /* If local, leave. */
883 * Timeout function due to lack of keepalive/traffic from the destination.
884 * Destroys connection if called.
886 * @param cls Closure (connection to destroy).
887 * @param tc TaskContext
890 connection_bck_timeout (void *cls,
891 const struct GNUNET_SCHEDULER_TaskContext *tc)
893 struct MeshConnection *c = cls;
895 c->bck_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
896 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
899 LOG (GNUNET_ERROR_TYPE_DEBUG,
900 "Connection %s[%X] FWD timed out. Destroying.\n",
901 GMT_2s (c->t), c->id);
903 if (GMC_is_origin (c, GNUNET_NO)) /* If local, leave. */
911 * Resets the connection timeout task, some other message has done the
913 * - For the first peer on the direction this means to send
914 * a keepalive or a path confirmation message (either create or ACK).
915 * - For all other peers, this means to destroy the connection,
916 * due to lack of activity.
917 * Starts the tiemout if no timeout was running (connection just created).
919 * @param c Connection whose timeout to reset.
920 * @param fwd Is this forward?
922 * TODO use heap to improve efficiency of scheduler.
925 connection_reset_timeout (struct MeshConnection *c, int fwd)
927 GNUNET_SCHEDULER_TaskIdentifier *ti;
928 GNUNET_SCHEDULER_Task f;
930 ti = fwd ? &c->fwd_maintenance_task : &c->bck_maintenance_task;
932 if (GNUNET_SCHEDULER_NO_TASK != *ti)
933 GNUNET_SCHEDULER_cancel (*ti);
935 if (GMC_is_origin (c, fwd)) /* Endpoint */
937 f = fwd ? &connection_fwd_keepalive : &connection_bck_keepalive;
938 *ti = GNUNET_SCHEDULER_add_delayed (refresh_connection_time, f, c);
942 struct GNUNET_TIME_Relative delay;
944 delay = GNUNET_TIME_relative_multiply (refresh_connection_time, 4);
945 f = fwd ? &connection_fwd_timeout : &connection_bck_timeout;
946 *ti = GNUNET_SCHEDULER_add_delayed (delay, f, c);
952 * Add the connection to the list of both neighbors.
954 * @param c Connection.
957 register_neighbors (struct MeshConnection *c)
959 struct MeshPeer *peer;
961 peer = get_next_hop (c);
962 if (GNUNET_NO == GMP_is_neighbor (peer))
967 GMP_add_connection (peer, c);
968 peer = get_prev_hop (c);
969 if (GNUNET_NO == GMP_is_neighbor (peer))
974 GMP_add_connection (peer, c);
979 * Remove the connection from the list of both neighbors.
981 * @param c Connection.
984 unregister_neighbors (struct MeshConnection *c)
986 struct MeshPeer *peer;
988 peer = get_next_hop (c);
989 GMP_remove_connection (peer, c);
991 peer = get_prev_hop (c);
992 GMP_remove_connection (peer, c);
998 * Bind the connection to the peer and the tunnel to that peer.
1000 * If the peer has no tunnel, create one. Update tunnel and connection
1001 * data structres to reflect new status.
1003 * @param c Connection.
1007 add_to_peer (struct MeshConnection *c, struct MeshPeer *peer)
1009 GMP_add_tunnel (peer);
1010 c->t = GMP_get_tunnel (peer);
1011 GMT_add_connection (c->t, c);
1014 /******************************************************************************/
1015 /******************************** API ***********************************/
1016 /******************************************************************************/
1019 * Core handler for connection creation.
1021 * @param cls Closure (unused).
1022 * @param peer Sender (neighbor).
1023 * @param message Message.
1025 * @return GNUNET_OK to keep the connection open,
1026 * GNUNET_SYSERR to close it (signal serious error)
1029 GMC_handle_create (void *cls, const struct GNUNET_PeerIdentity *peer,
1030 const struct GNUNET_MessageHeader *message)
1032 struct GNUNET_MESH_ConnectionCreate *msg;
1033 struct GNUNET_PeerIdentity *id;
1034 struct GNUNET_HashCode *cid;
1035 struct MeshPeerPath *path;
1036 struct MeshPeer *dest_peer;
1037 struct MeshPeer *orig_peer;
1038 struct MeshConnection *c;
1039 unsigned int own_pos;
1043 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1044 LOG (GNUNET_ERROR_TYPE_DEBUG, "Received a connection create msg\n");
1047 size = ntohs (message->size);
1048 if (size < sizeof (struct GNUNET_MESH_ConnectionCreate))
1050 GNUNET_break_op (0);
1054 /* Calculate hops */
1055 size -= sizeof (struct GNUNET_MESH_ConnectionCreate);
1056 if (size % sizeof (struct GNUNET_PeerIdentity))
1058 GNUNET_break_op (0);
1061 size /= sizeof (struct GNUNET_PeerIdentity);
1064 GNUNET_break_op (0);
1067 LOG (GNUNET_ERROR_TYPE_DEBUG, " path has %u hops.\n", size);
1069 /* Get parameters */
1070 msg = (struct GNUNET_MESH_ConnectionCreate *) message;
1072 id = (struct GNUNET_PeerIdentity *) &msg[1];
1073 LOG (GNUNET_ERROR_TYPE_DEBUG,
1074 " connection %s (%s).\n",
1075 GNUNET_h2s (cid), GNUNET_i2s (id));
1077 /* Create connection */
1078 c = connection_get (cid);
1082 LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating path...\n");
1083 path = path_new (size);
1085 for (i = 0; i < size; i++)
1087 LOG (GNUNET_ERROR_TYPE_DEBUG, " ... adding %s\n",
1088 GNUNET_i2s (&id[i]));
1089 path->peers[i] = GNUNET_PEER_intern (&id[i]);
1090 if (path->peers[i] == myid)
1093 if (own_pos == 0 && path->peers[own_pos] != myid)
1095 /* create path: self not found in path through self */
1096 GNUNET_break_op (0);
1097 path_destroy (path);
1100 LOG (GNUNET_ERROR_TYPE_DEBUG, " Own position: %u\n", own_pos);
1101 GMP_add_path_to_all (path, GNUNET_NO);
1102 LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating connection\n");
1103 c = GMC_new (cid, NULL, path_duplicate (path), own_pos);
1106 connection_reset_timeout (c, GNUNET_YES);
1112 if (MESH_CONNECTION_NEW == c->state)
1113 connection_change_state (c, MESH_CONNECTION_SENT);
1115 /* Remember peers */
1116 dest_peer = GMP_get (&id[size - 1]);
1117 orig_peer = GMP_get (&id[0]);
1119 /* Is it a connection to us? */
1120 if (c->own_pos == size - 1)
1122 LOG (GNUNET_ERROR_TYPE_DEBUG, " It's for us!\n");
1123 GMP_add_path_to_origin (orig_peer, path, GNUNET_YES);
1125 add_to_peer (c, orig_peer);
1126 if (MESH_TUNNEL3_NEW == GMT_get_state (c->t))
1127 GMT_change_state (c->t, MESH_TUNNEL3_WAITING);
1129 send_connection_ack (c, GNUNET_NO);
1130 if (MESH_CONNECTION_SENT == c->state)
1131 connection_change_state (c, MESH_CONNECTION_ACK);
1133 /* Keep tunnel alive in direction dest->owner*/
1134 connection_reset_timeout (c, GNUNET_NO);
1138 /* It's for somebody else! Retransmit. */
1139 LOG (GNUNET_ERROR_TYPE_DEBUG, " Retransmitting.\n");
1140 GMP_add_path (dest_peer, path_duplicate (path), GNUNET_NO);
1141 GMP_add_path_to_origin (orig_peer, path, GNUNET_NO);
1142 GMC_send_prebuilt_message (message, c, NULL, GNUNET_YES);
1149 * Core handler for path confirmations.
1151 * @param cls closure
1152 * @param message message
1153 * @param peer peer identity this notification is about
1155 * @return GNUNET_OK to keep the connection open,
1156 * GNUNET_SYSERR to close it (signal serious error)
1159 GMC_handle_confirm (void *cls, const struct GNUNET_PeerIdentity *peer,
1160 const struct GNUNET_MessageHeader *message)
1162 struct GNUNET_MESH_ConnectionACK *msg;
1163 struct MeshConnection *c;
1164 struct MeshPeerPath *p;
1165 struct MeshPeer *pi;
1168 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1169 LOG (GNUNET_ERROR_TYPE_DEBUG, "Received a connection ACK msg\n");
1170 msg = (struct GNUNET_MESH_ConnectionACK *) message;
1171 LOG (GNUNET_ERROR_TYPE_DEBUG, " on connection %s\n",
1172 GNUNET_h2s (&msg->cid));
1173 c = connection_get (&msg->cid);
1176 GNUNET_STATISTICS_update (stats, "# control on unknown connection",
1178 LOG (GNUNET_ERROR_TYPE_DEBUG, " don't know the connection!\n");
1183 LOG (GNUNET_ERROR_TYPE_DEBUG, " via peer %s\n",
1185 pi = GMP_get (peer);
1186 if (get_next_hop (c) == pi)
1188 LOG (GNUNET_ERROR_TYPE_DEBUG, " SYNACK\n");
1190 if (MESH_CONNECTION_SENT == c->state)
1191 connection_change_state (c, MESH_CONNECTION_ACK);
1193 else if (get_prev_hop (c) == pi)
1195 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK\n");
1197 connection_change_state (c, MESH_CONNECTION_READY);
1201 GNUNET_break_op (0);
1204 connection_reset_timeout (c, fwd);
1206 /* Add path to peers? */
1210 GMP_add_path_to_all (p, GNUNET_YES);
1217 /* Message for us as creator? */
1218 if (GMC_is_origin (c, GNUNET_YES))
1220 LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection (SYN)ACK for us!\n");
1221 connection_change_state (c, MESH_CONNECTION_READY);
1222 GMT_change_state (c->t, MESH_TUNNEL3_READY);
1223 send_connection_ack (c, GNUNET_YES);
1224 GMT_send_queued_data (c->t, GNUNET_YES);
1228 /* Message for us as destination? */
1229 if (GMC_is_terminal (c, GNUNET_YES))
1231 LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection ACK for us!\n");
1232 connection_change_state (c, MESH_CONNECTION_READY);
1233 GMT_change_state (c->t, MESH_TUNNEL3_READY);
1234 GMT_send_queued_data (c->t, GNUNET_NO);
1238 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
1239 GMC_send_prebuilt_message (message, c, NULL, fwd);
1245 * Core handler for notifications of broken paths
1247 * @param cls Closure (unused).
1248 * @param id Peer identity of sending neighbor.
1249 * @param message Message.
1251 * @return GNUNET_OK to keep the connection open,
1252 * GNUNET_SYSERR to close it (signal serious error)
1255 GMC_handle_broken (void* cls,
1256 const struct GNUNET_PeerIdentity* id,
1257 const struct GNUNET_MessageHeader* message)
1259 struct GNUNET_MESH_ConnectionBroken *msg;
1260 struct MeshConnection *c;
1263 LOG (GNUNET_ERROR_TYPE_DEBUG,
1264 "Received a CONNECTION BROKEN msg from %s\n", GNUNET_i2s (id));
1265 msg = (struct GNUNET_MESH_ConnectionBroken *) message;
1266 LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n",
1267 GNUNET_i2s (&msg->peer1));
1268 LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n",
1269 GNUNET_i2s (&msg->peer2));
1270 c = connection_get (&msg->cid);
1273 GNUNET_break_op (0);
1277 fwd = is_fwd (c, id);
1278 connection_cancel_queues (c, !fwd);
1279 if (GMC_is_terminal (c, fwd))
1281 if (0 < c->pending_messages)
1282 c->destroy = GNUNET_YES;
1288 GMC_send_prebuilt_message (message, c, NULL, fwd);
1289 c->destroy = GNUNET_YES;
1298 * Core handler for tunnel destruction
1300 * @param cls Closure (unused).
1301 * @param peer Peer identity of sending neighbor.
1302 * @param message Message.
1304 * @return GNUNET_OK to keep the connection open,
1305 * GNUNET_SYSERR to close it (signal serious error)
1308 GMC_handle_destroy (void *cls, const struct GNUNET_PeerIdentity *peer,
1309 const struct GNUNET_MessageHeader *message)
1311 struct GNUNET_MESH_ConnectionDestroy *msg;
1312 struct MeshConnection *c;
1315 msg = (struct GNUNET_MESH_ConnectionDestroy *) message;
1316 LOG (GNUNET_ERROR_TYPE_DEBUG,
1317 "Got a CONNECTION DESTROY message from %s\n",
1319 LOG (GNUNET_ERROR_TYPE_DEBUG,
1320 " for connection %s\n",
1321 GNUNET_h2s (&msg->cid));
1322 c = connection_get (&msg->cid);
1325 /* Probably already got the message from another path,
1326 * destroyed the tunnel and retransmitted to children.
1329 GNUNET_STATISTICS_update (stats, "# control on unknown tunnel",
1333 fwd = is_fwd (c, peer);
1334 if (GNUNET_SYSERR == fwd)
1336 GNUNET_break_op (0);
1339 GMC_send_prebuilt_message (message, c, NULL, fwd);
1340 c->destroy = GNUNET_YES;
1346 * Generic handler for mesh network encrypted traffic.
1348 * @param peer Peer identity this notification is about.
1349 * @param msg Encrypted message.
1351 * @return GNUNET_OK to keep the connection open,
1352 * GNUNET_SYSERR to close it (signal serious error)
1355 handle_mesh_encrypted (const struct GNUNET_PeerIdentity *peer,
1356 const struct GNUNET_MESH_Encrypted *msg)
1358 struct MeshConnection *c;
1359 struct MeshPeer *neighbor;
1360 struct MeshFlowControl *fc;
1361 GNUNET_PEER_Id peer_id;
1369 size = ntohs (msg->header.size);
1371 sizeof (struct GNUNET_MESH_Encrypted) +
1372 sizeof (struct GNUNET_MessageHeader))
1374 GNUNET_break_op (0);
1377 type = ntohs (msg->header.type);
1378 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1379 LOG (GNUNET_ERROR_TYPE_DEBUG, "got a %s message from %s\n",
1380 GNUNET_MESH_DEBUG_M2S (type), GNUNET_i2s (peer));
1382 /* Check connection */
1383 c = connection_get (&msg->cid);
1386 GNUNET_STATISTICS_update (stats, "# unknown connection", 1, GNUNET_NO);
1387 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING connection unknown\n");
1391 /* Check if origin is as expected */
1392 neighbor = get_prev_hop (c);
1393 peer_id = GNUNET_PEER_search (peer);
1394 if (peer_id == GMP_get_short_id (neighbor))
1400 neighbor = get_next_hop (c);
1401 if (peer_id == GMP_get_short_id (neighbor))
1407 /* Unexpected peer sending traffic on a connection. */
1408 GNUNET_break_op (0);
1414 fc = fwd ? &c->bck_fc : &c->fwd_fc;
1415 pid = ntohl (msg->pid);
1416 if (GMC_is_pid_bigger (pid, fc->last_ack_sent))
1418 GNUNET_STATISTICS_update (stats, "# unsolicited message", 1, GNUNET_NO);
1419 LOG (GNUNET_ERROR_TYPE_DEBUG,
1420 "WARNING Received PID %u, (prev %u), ACK %u\n",
1421 pid, fc->last_pid_recv, fc->last_ack_sent);
1424 if (GNUNET_NO == GMC_is_pid_bigger (pid, fc->last_pid_recv))
1426 GNUNET_STATISTICS_update (stats, "# duplicate PID", 1, GNUNET_NO);
1427 LOG (GNUNET_ERROR_TYPE_DEBUG,
1428 " Pid %u not expected (%u+), dropping!\n",
1429 pid, fc->last_pid_recv + 1);
1432 if (MESH_CONNECTION_SENT == c->state || MESH_CONNECTION_ACK == c->state)
1433 connection_change_state (c, MESH_CONNECTION_READY);
1434 connection_reset_timeout (c, fwd);
1435 fc->last_pid_recv = pid;
1437 /* Is this message for us? */
1438 if (GMC_is_terminal (c, fwd))
1440 /* TODO signature verification */
1441 LOG (GNUNET_ERROR_TYPE_DEBUG, " message for us!\n");
1442 GNUNET_STATISTICS_update (stats, "# messages received", 1, GNUNET_NO);
1449 fc->last_pid_recv = pid;
1450 GMT_handle_encrypted (c->t, msg, fwd);
1451 GMC_send_ack (c, fwd);
1455 /* Message not for us: forward to next hop */
1456 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
1457 ttl = ntohl (msg->ttl);
1458 LOG (GNUNET_ERROR_TYPE_DEBUG, " ttl: %u\n", ttl);
1461 GNUNET_STATISTICS_update (stats, "# TTL drops", 1, GNUNET_NO);
1462 LOG (GNUNET_ERROR_TYPE_WARNING, " TTL is 0, DROPPING!\n");
1463 GMC_send_ack (c, fwd);
1466 GNUNET_STATISTICS_update (stats, "# messages forwarded", 1, GNUNET_NO);
1468 GMC_send_prebuilt_message (&msg->header, c, NULL, fwd);
1475 * Core handler for encrypted mesh network traffic (channel mgmt, data).
1477 * @param cls Closure (unused).
1478 * @param message Message received.
1479 * @param peer Peer who sent the message.
1481 * @return GNUNET_OK to keep the connection open,
1482 * GNUNET_SYSERR to close it (signal serious error)
1485 GMC_handle_encrypted (void *cls, const struct GNUNET_PeerIdentity *peer,
1486 const struct GNUNET_MessageHeader *message)
1488 return handle_mesh_encrypted (peer,
1489 (struct GNUNET_MESH_Encrypted *)message);
1494 * Core handler for mesh network traffic point-to-point acks.
1496 * @param cls closure
1497 * @param message message
1498 * @param peer peer identity this notification is about
1500 * @return GNUNET_OK to keep the connection open,
1501 * GNUNET_SYSERR to close it (signal serious error)
1504 GMC_handle_ack (void *cls, const struct GNUNET_PeerIdentity *peer,
1505 const struct GNUNET_MessageHeader *message)
1507 struct GNUNET_MESH_ACK *msg;
1508 struct MeshConnection *c;
1509 struct MeshFlowControl *fc;
1514 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1515 LOG (GNUNET_ERROR_TYPE_DEBUG, "Got an ACK packet from %s!\n",
1517 msg = (struct GNUNET_MESH_ACK *) message;
1519 c = connection_get (&msg->cid);
1523 GNUNET_STATISTICS_update (stats, "# ack on unknown connection", 1,
1528 /* Is this a forward or backward ACK? */
1529 id = GNUNET_PEER_search (peer);
1530 if (GMP_get_short_id (get_next_hop (c)) == id)
1532 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD ACK\n");
1536 else if (GMP_get_short_id (get_prev_hop (c)) == id)
1538 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK ACK\n");
1544 GNUNET_break_op (0);
1548 ack = ntohl (msg->ack);
1549 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK %u (was %u)\n",
1550 ack, fc->last_ack_recv);
1551 if (GMC_is_pid_bigger (ack, fc->last_ack_recv))
1552 fc->last_ack_recv = ack;
1554 /* Cancel polling if the ACK is big enough. */
1555 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task &&
1556 GMC_is_pid_bigger (fc->last_ack_recv, fc->last_pid_sent))
1558 LOG (GNUNET_ERROR_TYPE_DEBUG, " Cancel poll\n");
1559 GNUNET_SCHEDULER_cancel (fc->poll_task);
1560 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
1561 fc->poll_time = GNUNET_TIME_UNIT_SECONDS;
1564 connection_unlock_queue (c, fwd);
1571 * Core handler for mesh network traffic point-to-point ack polls.
1573 * @param cls closure
1574 * @param message message
1575 * @param peer peer identity this notification is about
1577 * @return GNUNET_OK to keep the connection open,
1578 * GNUNET_SYSERR to close it (signal serious error)
1581 GMC_handle_poll (void *cls, const struct GNUNET_PeerIdentity *peer,
1582 const struct GNUNET_MessageHeader *message)
1584 struct GNUNET_MESH_Poll *msg;
1585 struct MeshConnection *c;
1586 struct MeshFlowControl *fc;
1591 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1592 LOG (GNUNET_ERROR_TYPE_DEBUG, "Got a POLL packet from %s!\n",
1595 msg = (struct GNUNET_MESH_Poll *) message;
1597 c = connection_get (&msg->cid);
1601 GNUNET_STATISTICS_update (stats, "# poll on unknown connection", 1,
1603 GNUNET_break_op (0);
1607 /* Is this a forward or backward ACK?
1608 * Note: a poll should never be needed in a loopback case,
1609 * since there is no possiblility of packet loss there, so
1610 * this way of discerining FWD/BCK should not be a problem.
1612 id = GNUNET_PEER_search (peer);
1613 if (GMP_get_short_id (get_next_hop (c)) == id)
1615 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD ACK\n");
1618 else if (GMP_get_short_id (get_prev_hop (c)) == id)
1620 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK ACK\n");
1625 GNUNET_break_op (0);
1629 pid = ntohl (msg->pid);
1630 LOG (GNUNET_ERROR_TYPE_DEBUG, " PID %u, OLD %u\n",
1631 pid, fc->last_pid_recv);
1632 fc->last_pid_recv = pid;
1633 fwd = fc == &c->fwd_fc;
1634 GMC_send_ack (c, fwd);
1641 * Core handler for mesh keepalives.
1643 * @param cls closure
1644 * @param message message
1645 * @param peer peer identity this notification is about
1646 * @return GNUNET_OK to keep the connection open,
1647 * GNUNET_SYSERR to close it (signal serious error)
1649 * TODO: Check who we got this from, to validate route.
1652 GMC_handle_keepalive (void *cls, const struct GNUNET_PeerIdentity *peer,
1653 const struct GNUNET_MessageHeader *message)
1655 struct GNUNET_MESH_ConnectionKeepAlive *msg;
1656 struct MeshConnection *c;
1657 struct MeshPeer *neighbor;
1660 msg = (struct GNUNET_MESH_ConnectionKeepAlive *) message;
1661 LOG (GNUNET_ERROR_TYPE_DEBUG, "got a keepalive packet from %s\n",
1664 c = connection_get (&msg->cid);
1667 GNUNET_STATISTICS_update (stats, "# keepalive on unknown connection", 1,
1672 fwd = GNUNET_MESSAGE_TYPE_MESH_FWD_KEEPALIVE == ntohs (message->type) ?
1673 GNUNET_YES : GNUNET_NO;
1675 /* Check if origin is as expected */
1676 neighbor = get_hop (c, fwd);
1677 if (GNUNET_PEER_search (peer) != GMP_get_short_id (neighbor))
1679 GNUNET_break_op (0);
1683 connection_change_state (c, MESH_CONNECTION_READY);
1684 connection_reset_timeout (c, fwd);
1686 if (GMC_is_terminal (c, fwd))
1689 GNUNET_STATISTICS_update (stats, "# keepalives forwarded", 1, GNUNET_NO);
1690 GMC_send_prebuilt_message (message, c, NULL, fwd);
1697 * Send an ACK on the appropriate connection/channel, depending on
1698 * the direction and the position of the peer.
1700 * @param c Which connection to send the hop-by-hop ACK.
1701 * @param fwd Is this a fwd ACK? (will go dest->root)
1704 GMC_send_ack (struct MeshConnection *c, int fwd)
1706 unsigned int buffer;
1708 LOG (GNUNET_ERROR_TYPE_DEBUG,
1709 "GMC send %s ACK on %s\n",
1710 fwd ? "FWD" : "BCK", GMC_2s (c));
1718 /* Get available buffer space */
1719 if (GMC_is_terminal (c, fwd))
1721 LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from all channels\n");
1722 buffer = GMT_get_buffer (c->t, fwd);
1726 LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from one connection\n");
1727 buffer = GMC_get_buffer (c, fwd);
1729 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer available: %u\n", buffer);
1731 /* Send available buffer space */
1732 if (GMC_is_origin (c, fwd))
1734 GNUNET_assert (NULL != c->t);
1735 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channels...\n");
1738 LOG (GNUNET_ERROR_TYPE_DEBUG, " really sending!\n");
1739 GMT_unchoke_channels (c->t, fwd);
1744 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on connection\n");
1745 send_ack (c, buffer, fwd);
1751 * Initialize the connections subsystem
1753 * @param c Configuration handle.
1756 GMC_init (const struct GNUNET_CONFIGURATION_Handle *c)
1758 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
1760 GNUNET_CONFIGURATION_get_value_number (c, "MESH", "MAX_MSGS_QUEUE",
1763 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
1764 "MESH", "MAX_MSGS_QUEUE", "MISSING");
1765 GNUNET_SCHEDULER_shutdown ();
1770 GNUNET_CONFIGURATION_get_value_number (c, "MESH", "MAX_CONNECTIONS",
1773 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
1774 "MESH", "MAX_CONNECTIONS", "MISSING");
1775 GNUNET_SCHEDULER_shutdown ();
1780 GNUNET_CONFIGURATION_get_value_time (c, "MESH", "REFRESH_CONNECTION_TIME",
1781 &refresh_connection_time))
1783 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
1784 "MESH", "REFRESH_CONNECTION_TIME", "MISSING");
1785 GNUNET_SCHEDULER_shutdown ();
1788 connections = GNUNET_CONTAINER_multihashmap_create (1024, GNUNET_YES);
1792 * Shut down the connections subsystem.
1797 GNUNET_CONTAINER_multihashmap_destroy (connections);
1801 struct MeshConnection *
1802 GMC_new (const struct GNUNET_HashCode *cid,
1803 struct MeshTunnel3 *t,
1804 struct MeshPeerPath *p,
1805 unsigned int own_pos)
1807 struct MeshConnection *c;
1809 c = GNUNET_new (struct MeshConnection);
1811 GNUNET_CONTAINER_multihashmap_put (connections, &c->id, c,
1812 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST);
1813 fc_init (&c->fwd_fc);
1814 fc_init (&c->bck_fc);
1819 if (own_pos > p->length - 1)
1825 c->own_pos = own_pos;
1830 c->fwd_maintenance_task =
1831 GNUNET_SCHEDULER_add_delayed (refresh_connection_time,
1832 &connection_fwd_keepalive, c);
1834 register_neighbors (c);
1840 GMC_destroy (struct MeshConnection *c)
1845 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying connection %s\n", GMC_2s (c));
1847 /* Cancel all traffic */
1848 connection_cancel_queues (c, GNUNET_YES);
1849 connection_cancel_queues (c, GNUNET_NO);
1851 /* Cancel maintainance task (keepalive/timeout) */
1852 if (GNUNET_SCHEDULER_NO_TASK != c->fwd_maintenance_task)
1853 GNUNET_SCHEDULER_cancel (c->fwd_maintenance_task);
1854 if (GNUNET_SCHEDULER_NO_TASK != c->bck_maintenance_task)
1855 GNUNET_SCHEDULER_cancel (c->bck_maintenance_task);
1857 /* Unregister from neighbors */
1858 unregister_neighbors (c);
1861 GNUNET_STATISTICS_update (stats, "# connections", -1, GNUNET_NO);
1863 GMT_remove_connection (c->t, c);
1868 * Get the connection ID.
1870 * @param c Connection to get the ID from.
1872 * @return ID of the connection.
1874 const struct GNUNET_HashCode *
1875 GMC_get_id (const struct MeshConnection *c)
1882 * Get the connection path.
1884 * @param c Connection to get the path from.
1886 * @return path used by the connection.
1888 const struct MeshPeerPath *
1889 GMC_get_path (const struct MeshConnection *c)
1896 * Get the connection state.
1898 * @param c Connection to get the state from.
1900 * @return state of the connection.
1902 enum MeshConnectionState
1903 GMC_get_state (const struct MeshConnection *c)
1909 * Get the connection tunnel.
1911 * @param c Connection to get the tunnel from.
1913 * @return tunnel of the connection.
1915 struct MeshTunnel3 *
1916 GMC_get_tunnel (const struct MeshConnection *c)
1923 * Get free buffer space in a connection.
1925 * @param c Connection.
1926 * @param fwd Is query about FWD traffic?
1928 * @return Free buffer space [0 - max_msgs_queue/max_connections]
1931 GMC_get_buffer (struct MeshConnection *c, int fwd)
1933 struct MeshFlowControl *fc;
1935 fc = fwd ? &c->fwd_fc : &c->bck_fc;
1937 return (fc->queue_max - fc->queue_n);
1941 * Get how many messages have we allowed to send to us from a direction.
1943 * @param c Connection.
1944 * @param fwd Are we asking about traffic from FWD (BCK messages)?
1946 * @return last_ack_sent - last_pid_recv
1949 GMC_get_allowed (struct MeshConnection *c, int fwd)
1951 struct MeshFlowControl *fc;
1953 fc = fwd ? &c->fwd_fc : &c->bck_fc;
1954 if (GMC_is_pid_bigger(fc->last_pid_recv, fc->last_ack_sent))
1958 return (fc->last_ack_sent - fc->last_pid_recv);
1962 * Get messages queued in a connection.
1964 * @param c Connection.
1965 * @param fwd Is query about FWD traffic?
1967 * @return Number of messages queued.
1970 GMC_get_qn (struct MeshConnection *c, int fwd)
1972 struct MeshFlowControl *fc;
1974 fc = fwd ? &c->fwd_fc : &c->bck_fc;
1981 * Allow the connection to advertise a buffer of the given size.
1983 * The connection will send an @c fwd ACK message (so: in direction !fwd)
1984 * allowing up to last_pid_recv + buffer.
1986 * @param c Connection.
1987 * @param buffer How many more messages the connection can accept.
1988 * @param fwd Is this about FWD traffic? (The ack will go dest->root).
1991 GMC_allow (struct MeshConnection *c, unsigned int buffer, int fwd)
1993 send_ack (c, buffer, fwd);
1998 * Notify other peers on a connection of a broken link. Mark connections
1999 * to destroy after all traffic has been sent.
2001 * @param c Connection on which there has been a disconnection.
2002 * @param peer Peer that disconnected.
2005 GMC_notify_broken (struct MeshConnection *c,
2006 struct MeshPeer *peer)
2010 fwd = peer == get_prev_hop (c);
2012 connection_cancel_queues (c, !fwd);
2013 if (GMC_is_terminal (c, fwd))
2015 /* Local shutdown, no one to notify about this. */
2020 send_broken (c, &my_full_id, GMP_get_id (peer), fwd);
2022 /* Connection will have at least one pending message
2023 * (the one we just scheduled), so no point in checking whether to
2024 * destroy immediately. */
2025 c->destroy = GNUNET_YES;
2032 * Is this peer the first one on the connection?
2034 * @param c Connection.
2035 * @param fwd Is this about fwd traffic?
2037 * @return GNUNET_YES if origin, GNUNET_NO if relay/terminal.
2040 GMC_is_origin (struct MeshConnection *c, int fwd)
2042 if (!fwd && c->path->length - 1 == c->own_pos )
2044 if (fwd && 0 == c->own_pos)
2051 * Is this peer the last one on the connection?
2053 * @param c Connection.
2054 * @param fwd Is this about fwd traffic?
2055 * Note that the ROOT is the terminal for BCK traffic!
2057 * @return GNUNET_YES if terminal, GNUNET_NO if relay/origin.
2060 GMC_is_terminal (struct MeshConnection *c, int fwd)
2062 return GMC_is_origin (c, !fwd);
2067 * See if we are allowed to send by the next hop in the given direction.
2069 * @param c Connection.
2070 * @param fwd Is this about fwd traffic?
2072 * @return GNUNET_YES in case it's OK.
2075 GMC_is_sendable (struct MeshConnection *c, int fwd)
2077 struct MeshFlowControl *fc;
2079 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2080 if (GMC_is_pid_bigger (fc->last_ack_recv, fc->last_pid_sent))
2086 * Sends an already built message on a connection, properly registering
2087 * all used resources.
2089 * @param message Message to send. Function makes a copy of it.
2090 * If message is not hop-by-hop, decrements TTL of copy.
2091 * @param c Connection on which this message is transmitted.
2092 * @param ch Channel on which this message is transmitted, or NULL.
2093 * @param fwd Is this a fwd message?
2096 GMC_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2097 struct MeshConnection *c,
2098 struct MeshChannel *ch,
2101 struct MeshFlowControl *fc;
2107 size = ntohs (message->size);
2108 data = GNUNET_malloc (size);
2109 memcpy (data, message, size);
2110 type = ntohs (message->type);
2111 LOG (GNUNET_ERROR_TYPE_DEBUG, "Send %s (%u) on connection %s\n",
2112 GNUNET_MESH_DEBUG_M2S (type), size, GMC_2s (c));
2114 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2115 droppable = GNUNET_YES;
2118 struct GNUNET_MESH_Encrypted *emsg;
2119 struct GNUNET_MESH_ACK *amsg;
2120 struct GNUNET_MESH_Poll *pmsg;
2121 struct GNUNET_MESH_ConnectionDestroy *dmsg;
2122 struct GNUNET_MESH_ConnectionBroken *bmsg;
2125 case GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED:
2126 emsg = (struct GNUNET_MESH_Encrypted *) data;
2127 ttl = ntohl (emsg->ttl);
2130 GNUNET_break_op (0);
2134 emsg->ttl = htonl (ttl - 1);
2135 emsg->pid = htonl (fwd ? c->fwd_fc.next_pid++ : c->bck_fc.next_pid++);
2136 LOG (GNUNET_ERROR_TYPE_DEBUG, " Q_N+ %p %u\n", fc, fc->queue_n);
2138 LOG (GNUNET_ERROR_TYPE_DEBUG, "pid %u\n", ntohl (emsg->pid));
2139 LOG (GNUNET_ERROR_TYPE_DEBUG, "last pid %u\n", fc->last_pid_sent);
2140 LOG (GNUNET_ERROR_TYPE_DEBUG, " ack %u\n", fc->last_ack_recv);
2141 if (GMC_is_pid_bigger (fc->last_pid_sent + 1, fc->last_ack_recv))
2143 GMC_start_poll (c, fwd);
2147 case GNUNET_MESSAGE_TYPE_MESH_ACK:
2148 amsg = (struct GNUNET_MESH_ACK *) data;
2150 LOG (GNUNET_ERROR_TYPE_DEBUG, " ack %u\n", ntohl (amsg->ack));
2151 droppable = GNUNET_NO;
2154 case GNUNET_MESSAGE_TYPE_MESH_POLL:
2155 pmsg = (struct GNUNET_MESH_Poll *) data;
2157 pmsg->pid = htonl (fwd ? c->fwd_fc.last_pid_sent : c->bck_fc.last_pid_sent);
2158 LOG (GNUNET_ERROR_TYPE_DEBUG, " poll %u\n", ntohl (pmsg->pid));
2159 droppable = GNUNET_NO;
2162 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_DESTROY:
2163 dmsg = (struct GNUNET_MESH_ConnectionDestroy *) data;
2168 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_BROKEN:
2169 bmsg = (struct GNUNET_MESH_ConnectionBroken *) data;
2174 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_CREATE:
2175 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_ACK:
2182 if (fc->queue_n > fc->queue_max && droppable)
2184 GNUNET_STATISTICS_update (stats, "# messages dropped (buffer full)",
2187 LOG (GNUNET_ERROR_TYPE_DEBUG,
2188 "queue full: %u/%u\n",
2189 fc->queue_n, fc->queue_max);
2190 if (GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED == type)
2192 return; /* Drop this message */
2195 c->pending_messages++;
2197 GMP_queue_add (get_hop (c, fwd), data, type, size, c, ch, fwd,
2198 &message_sent, NULL);
2203 * Sends a CREATE CONNECTION message for a path to a peer.
2204 * Changes the connection and tunnel states if necessary.
2206 * @param connection Connection to create.
2209 GMC_send_create (struct MeshConnection *connection)
2211 enum MeshTunnel3State state;
2214 size = sizeof (struct GNUNET_MESH_ConnectionCreate);
2215 size += connection->path->length * sizeof (struct GNUNET_PeerIdentity);
2216 LOG (GNUNET_ERROR_TYPE_DEBUG, "Send connection create\n");
2217 GMP_queue_add (get_next_hop (connection), NULL,
2218 GNUNET_MESSAGE_TYPE_MESH_CONNECTION_CREATE,
2219 size, connection, NULL,
2220 GNUNET_YES, &message_sent, NULL);
2221 state = GMT_get_state (connection->t);
2222 if (MESH_TUNNEL3_SEARCHING == state || MESH_TUNNEL3_NEW == state)
2223 GMT_change_state (connection->t, MESH_TUNNEL3_WAITING);
2224 if (MESH_CONNECTION_NEW == connection->state)
2225 connection_change_state (connection, MESH_CONNECTION_SENT);
2230 * Send a message to all peers in this connection that the connection
2231 * is no longer valid.
2233 * If some peer should not receive the message, it should be zero'ed out
2234 * before calling this function.
2236 * @param c The connection whose peers to notify.
2239 GMC_send_destroy (struct MeshConnection *c)
2241 struct GNUNET_MESH_ConnectionDestroy msg;
2243 if (GNUNET_YES == c->destroy)
2246 msg.header.size = htons (sizeof (msg));
2247 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CONNECTION_DESTROY);;
2249 LOG (GNUNET_ERROR_TYPE_DEBUG,
2250 " sending connection destroy for connection %s\n",
2253 if (GNUNET_NO == GMC_is_terminal (c, GNUNET_YES))
2254 GMC_send_prebuilt_message (&msg.header, c, NULL, GNUNET_YES);
2255 if (GNUNET_NO == GMC_is_terminal (c, GNUNET_NO))
2256 GMC_send_prebuilt_message (&msg.header, c, NULL, GNUNET_NO);
2257 c->destroy = GNUNET_YES;
2262 * @brief Start a polling timer for the connection.
2264 * When a neighbor does not accept more traffic on the connection it could be
2265 * caused by a simple congestion or by a lost ACK. Polling enables to check
2266 * for the lastest ACK status for a connection.
2268 * @param c Connection.
2269 * @param fwd Should we poll in the FWD direction?
2272 GMC_start_poll (struct MeshConnection *c, int fwd)
2274 struct MeshFlowControl *fc;
2276 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2277 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task)
2281 fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time,
2288 * @brief Stop polling a connection for ACKs.
2290 * Once we have enough ACKs for future traffic, polls are no longer necessary.
2292 * @param c Connection.
2293 * @param fwd Should we stop the poll in the FWD direction?
2296 GMC_stop_poll (struct MeshConnection *c, int fwd)
2298 struct MeshFlowControl *fc;
2300 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2301 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task)
2303 GNUNET_SCHEDULER_cancel (fc->poll_task);
2304 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
2309 * Get a (static) string for a connection.
2311 * @param c Connection.
2314 GMC_2s (struct MeshConnection *c)
2318 static char buf[128];
2320 sprintf (buf, "%s (->%s)", GNUNET_h2s (&c->id), GMT_2s (c->t));
2323 return GNUNET_h2s (&c->id);