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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16 along with GNUnet; see the file COPYING. If not, write to the
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"
40 #define LOG(level, ...) GNUNET_log_from (level,"mesh-con",__VA_ARGS__)
42 #define MESH_MAX_POLL_TIME GNUNET_TIME_relative_multiply (\
43 GNUNET_TIME_UNIT_MINUTES,\
48 /******************************************************************************/
49 /******************************** STRUCTS **********************************/
50 /******************************************************************************/
53 * Struct to encapsulate all the Flow Control information to a peer to which
54 * we are directly connected (on a core level).
56 struct MeshFlowControl
59 * Connection this controls.
61 struct MeshConnection *c;
64 * How many messages are in the queue on this connection.
69 * How many messages do we accept in the queue.
71 unsigned int queue_max;
79 * ID of the last packet sent towards the peer.
81 uint32_t last_pid_sent;
84 * ID of the last packet received from the peer.
86 uint32_t last_pid_recv;
89 * Last ACK sent to the peer (peer can't send more than this PID).
91 uint32_t last_ack_sent;
94 * Last ACK sent towards the origin (for traffic towards leaf node).
96 uint32_t last_ack_recv;
99 * Task to poll the peer in case of a lost ACK causes stall.
101 GNUNET_SCHEDULER_TaskIdentifier poll_task;
104 * How frequently to poll for ACKs.
106 struct GNUNET_TIME_Relative poll_time;
110 * Keep a record of the last messages sent on this connection.
112 struct MeshConnectionPerformance
115 * Circular buffer for storing measurements.
117 double usecsperbyte[AVG_MSGS];
120 * Running average of @c usecsperbyte.
125 * How many values of @c usecsperbyte are valid.
130 * Index of the next "free" position in @c usecsperbyte.
137 * Struct containing all information regarding a connection to a peer.
139 struct MeshConnection
142 * Tunnel this connection is part of.
144 struct MeshTunnel3 *t;
147 * Flow control information for traffic fwd.
149 struct MeshFlowControl fwd_fc;
152 * Flow control information for traffic bck.
154 struct MeshFlowControl bck_fc;
157 * Measure connection performance on the endpoint.
159 struct MeshConnectionPerformance *perf;
162 * ID of the connection.
164 struct GNUNET_HashCode id;
167 * State of the connection.
169 enum MeshConnectionState state;
172 * Path being used for the tunnel.
174 struct MeshPeerPath *path;
177 * Position of the local peer in the path.
179 unsigned int own_pos;
182 * Task to keep the used paths alive at the owner,
183 * time tunnel out on all the other peers.
185 GNUNET_SCHEDULER_TaskIdentifier fwd_maintenance_task;
188 * Task to keep the used paths alive at the destination,
189 * time tunnel out on all the other peers.
191 GNUNET_SCHEDULER_TaskIdentifier bck_maintenance_task;
194 * Pending message count.
196 int pending_messages;
199 * Destroy flag: if true, destroy on last message.
204 /******************************************************************************/
205 /******************************* GLOBALS ***********************************/
206 /******************************************************************************/
209 * Global handle to the statistics service.
211 extern struct GNUNET_STATISTICS_Handle *stats;
214 * Local peer own ID (memory efficient handle).
216 extern GNUNET_PEER_Id myid;
219 * Local peer own ID (full value).
221 extern struct GNUNET_PeerIdentity my_full_id;
224 * Connections known, indexed by cid (MeshConnection).
226 static struct GNUNET_CONTAINER_MultiHashMap *connections;
229 * How many connections are we willing to maintain.
230 * Local connections are always allowed, even if there are more connections than max.
232 static unsigned long long max_connections;
235 * How many messages *in total* are we willing to queue, divide by number of
236 * connections to get connection queue size.
238 static unsigned long long max_msgs_queue;
241 * How often to send path keepalives. Paths timeout after 4 missed.
243 static struct GNUNET_TIME_Relative refresh_connection_time;
246 /******************************************************************************/
247 /******************************** STATIC ***********************************/
248 /******************************************************************************/
250 #if 0 // avoid compiler warning for unused static function
252 fc_debug (struct MeshFlowControl *fc)
254 LOG (GNUNET_ERROR_TYPE_DEBUG, " IN: %u/%u\n",
255 fc->last_pid_recv, fc->last_ack_sent);
256 LOG (GNUNET_ERROR_TYPE_DEBUG, " OUT: %u/%u\n",
257 fc->last_pid_sent, fc->last_ack_recv);
258 LOG (GNUNET_ERROR_TYPE_DEBUG, " QUEUE: %u/%u\n",
259 fc->queue_n, fc->queue_max);
263 connection_debug (struct MeshConnection *c)
267 LOG (GNUNET_ERROR_TYPE_DEBUG, "*** DEBUG NULL CONNECTION ***\n");
270 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s:%X\n",
271 peer2s (c->t->peer), GMC_2s (c));
272 LOG (GNUNET_ERROR_TYPE_DEBUG, " state: %u, pending msgs: %u\n",
273 c->state, c->pending_messages);
274 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD FC\n");
275 fc_debug (&c->fwd_fc);
276 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK FC\n");
277 fc_debug (&c->bck_fc);
282 * Get string description for tunnel state.
284 * @param s Tunnel state.
286 * @return String representation.
289 GMC_state2s (enum MeshConnectionState s)
293 case MESH_CONNECTION_NEW:
294 return "MESH_CONNECTION_NEW";
295 case MESH_CONNECTION_SENT:
296 return "MESH_CONNECTION_SENT";
297 case MESH_CONNECTION_ACK:
298 return "MESH_CONNECTION_ACK";
299 case MESH_CONNECTION_READY:
300 return "MESH_CONNECTION_READY";
302 return "MESH_CONNECTION_STATE_ERROR";
308 * Initialize a Flow Control structure to the initial state.
310 * @param fc Flow Control structure to initialize.
313 fc_init (struct MeshFlowControl *fc)
316 fc->last_pid_sent = (uint32_t) -1; /* Next (expected) = 0 */
317 fc->last_pid_recv = (uint32_t) -1;
318 fc->last_ack_sent = (uint32_t) 0;
319 fc->last_ack_recv = (uint32_t) 0;
320 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
321 fc->poll_time = GNUNET_TIME_UNIT_SECONDS;
323 fc->queue_max = (max_msgs_queue / max_connections) + 1;
330 * @param cid Connection ID.
332 static struct MeshConnection *
333 connection_get (const struct GNUNET_HashCode *cid)
335 return GNUNET_CONTAINER_multihashmap_get (connections, cid);
340 connection_change_state (struct MeshConnection* c,
341 enum MeshConnectionState state)
343 LOG (GNUNET_ERROR_TYPE_DEBUG,
344 "Connection %s state was %s\n",
345 GMC_2s (c), GMC_state2s (c->state));
346 LOG (GNUNET_ERROR_TYPE_DEBUG,
347 "Connection %s state is now %s\n",
348 GMC_2s (c), GMC_state2s (state));
354 * Send an ACK on the connection, informing the predecessor about
355 * the available buffer space. Should not be called in case the peer
356 * is origin (no predecessor).
358 * Note that for fwd ack, the FWD mean forward *traffic* (root->dest),
359 * the ACK itself goes "back" (dest->root).
361 * @param c Connection on which to send the ACK.
362 * @param buffer How much space free to advertise?
363 * @param fwd Is this FWD ACK? (Going dest->owner)
366 send_ack (struct MeshConnection *c, unsigned int buffer, int fwd)
368 struct MeshFlowControl *next_fc;
369 struct MeshFlowControl *prev_fc;
370 struct GNUNET_MESH_ACK msg;
374 /* If origin, there is no connection to send ACKs. Wrong function! */
375 if (GMC_is_origin (c, fwd))
381 next_fc = fwd ? &c->fwd_fc : &c->bck_fc;
382 prev_fc = fwd ? &c->bck_fc : &c->fwd_fc;
384 LOG (GNUNET_ERROR_TYPE_DEBUG,
385 "connection send %s ack on %s\n",
386 fwd ? "FWD" : "BCK", GMC_2s (c));
388 /* Check if we need to transmit the ACK */
389 delta = prev_fc->last_ack_sent - prev_fc->last_pid_recv;
390 if (3 < delta && buffer < delta)
392 LOG (GNUNET_ERROR_TYPE_DEBUG, "Not sending ACK, buffer > 3\n");
393 LOG (GNUNET_ERROR_TYPE_DEBUG,
394 " last pid recv: %u, last ack sent: %u\n",
395 prev_fc->last_pid_recv, prev_fc->last_ack_sent);
399 /* Ok, ACK might be necessary, what PID to ACK? */
400 ack = prev_fc->last_pid_recv + buffer;
401 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK %u\n", ack);
402 LOG (GNUNET_ERROR_TYPE_DEBUG,
403 " last pid %u, last ack %u, qmax %u, q %u\n",
404 prev_fc->last_pid_recv, prev_fc->last_ack_sent,
405 next_fc->queue_max, next_fc->queue_n);
406 if (ack == prev_fc->last_ack_sent)
408 LOG (GNUNET_ERROR_TYPE_DEBUG, "Not sending FWD ACK, not needed\n");
412 prev_fc->last_ack_sent = ack;
414 /* Build ACK message and send on connection */
415 msg.header.size = htons (sizeof (msg));
416 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_ACK);
417 msg.ack = htonl (ack);
420 GMC_send_prebuilt_message (&msg.header, c, !fwd);
425 * Callback called when a queued message is sent.
427 * Calculates the average time and connection packet tracking.
429 * @param cls Closure.
430 * @param c Connection this message was on.
431 * @param type Type of message sent.
432 * @param fwd Was this a FWD going message?
433 * @param size Size of the message.
434 * @param wait Time spent waiting for core (only the time for THIS message)
437 message_sent (void *cls,
438 struct MeshConnection *c, uint16_t type,
439 int fwd, size_t size,
440 struct GNUNET_TIME_Relative wait)
442 struct MeshConnectionPerformance *p;
443 struct MeshFlowControl *fc;
446 fc = fwd ? &c->fwd_fc : &c->bck_fc;
447 LOG (GNUNET_ERROR_TYPE_DEBUG, "! sent %s\n", GNUNET_MESH_DEBUG_M2S (type));
448 LOG (GNUNET_ERROR_TYPE_DEBUG, "! C_P- %p %u\n", c, c->pending_messages);
449 c->pending_messages--;
450 if (GNUNET_YES == c->destroy && 0 == c->pending_messages)
452 LOG (GNUNET_ERROR_TYPE_DEBUG, "! destroying connection!\n");
456 /* Send ACK if needed, after accounting for sent ID in fc->queue_n */
459 case GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED:
461 LOG (GNUNET_ERROR_TYPE_DEBUG, "! Q_N- %p %u\n", fc, fc->queue_n);
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;
499 * Get the previous hop in a connection
501 * @param c Connection.
503 * @return Previous peer in the connection.
505 static struct MeshPeer *
506 get_prev_hop (const struct MeshConnection *c)
510 LOG (GNUNET_ERROR_TYPE_DEBUG, "Get prev hop, own pos %u\n", c->own_pos);
511 if (0 == c->own_pos || c->path->length < 2)
512 id = c->path->peers[0];
514 id = c->path->peers[c->own_pos - 1];
516 return GMP_get_short (id);
521 * Get the next hop in a connection
523 * @param c Connection.
525 * @return Next peer in the connection.
527 static struct MeshPeer *
528 get_next_hop (const struct MeshConnection *c)
532 if ((c->path->length - 1) == c->own_pos || c->path->length < 2)
533 id = c->path->peers[c->path->length - 1];
535 id = c->path->peers[c->own_pos + 1];
537 return GMP_get_short (id);
542 * Get the hop in a connection.
544 * @param c Connection.
545 * @param fwd Next hop?
547 * @return Next peer in the connection.
549 static struct MeshPeer *
550 get_hop (struct MeshConnection *c, int fwd)
553 return get_next_hop (c);
554 return get_prev_hop (c);
559 * Is traffic coming from this sender 'FWD' traffic?
561 * @param c Connection to check.
562 * @param sender Peer identity of neighbor.
564 * @return #GNUNET_YES in case the sender is the 'prev' hop and therefore
565 * the traffic is 'FWD'.
566 * #GNUNET_NO for BCK.
567 * #GNUNET_SYSERR for errors.
570 is_fwd (const struct MeshConnection *c,
571 const struct GNUNET_PeerIdentity *sender)
575 id = GNUNET_PEER_search (sender);
576 if (GMP_get_short_id (get_prev_hop (c)) == id)
579 if (GMP_get_short_id (get_next_hop (c)) == id)
583 return GNUNET_SYSERR;
588 * Sends a CONNECTION ACK message in reponse to a received CONNECTION_CREATE
589 * or a first CONNECTION_ACK directed to us.
591 * @param connection Connection to confirm.
592 * @param fwd Should we send it FWD? (root->dest)
593 * (First (~SYNACK) goes BCK, second (~ACK) goes FWD)
596 send_connection_ack (struct MeshConnection *connection, int fwd)
598 struct MeshTunnel3 *t;
601 LOG (GNUNET_ERROR_TYPE_DEBUG, "Send connection %s ACK\n",
602 !fwd ? "FWD" : "BCK");
603 GMP_queue_add (get_hop (connection, fwd), NULL,
604 GNUNET_MESSAGE_TYPE_MESH_CONNECTION_ACK,
605 sizeof (struct GNUNET_MESH_ConnectionACK),
606 connection, fwd, &message_sent, NULL);
607 connection->pending_messages++;
608 if (MESH_TUNNEL3_NEW == GMT_get_state (t))
609 GMT_change_state (t, MESH_TUNNEL3_WAITING);
610 if (MESH_CONNECTION_READY != connection->state)
611 connection_change_state (connection, MESH_CONNECTION_SENT);
616 * Send a notification that a connection is broken.
618 * @param c Connection that is broken.
619 * @param id1 Peer that has disconnected.
620 * @param id2 Peer that has disconnected.
621 * @param fwd Direction towards which to send it.
624 send_broken (struct MeshConnection *c,
625 const struct GNUNET_PeerIdentity *id1,
626 const struct GNUNET_PeerIdentity *id2,
629 struct GNUNET_MESH_ConnectionBroken msg;
631 msg.header.size = htons (sizeof (struct GNUNET_MESH_ConnectionBroken));
632 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CONNECTION_BROKEN);
636 GMC_send_prebuilt_message (&msg.header, c, fwd);
642 * Send keepalive packets for a connection.
644 * @param c Connection to keep alive..
645 * @param fwd Is this a FWD keepalive? (owner -> dest).
648 connection_keepalive (struct MeshConnection *c, int fwd)
650 struct GNUNET_MESH_ConnectionKeepAlive *msg;
651 size_t size = sizeof (struct GNUNET_MESH_ConnectionKeepAlive);
655 type = fwd ? GNUNET_MESSAGE_TYPE_MESH_FWD_KEEPALIVE :
656 GNUNET_MESSAGE_TYPE_MESH_BCK_KEEPALIVE;
658 LOG (GNUNET_ERROR_TYPE_DEBUG,
659 "sending %s keepalive for connection %s]\n",
660 fwd ? "FWD" : "BCK", GMC_2s (c));
662 msg = (struct GNUNET_MESH_ConnectionKeepAlive *) cbuf;
663 msg->header.size = htons (size);
664 msg->header.type = htons (type);
667 GMC_send_prebuilt_message (&msg->header, c, fwd);
672 * Send CONNECTION_{CREATE/ACK} packets for a connection.
674 * @param c Connection for which to send the message.
675 * @param fwd If #GNUNET_YES, send CREATE, otherwise send ACK.
678 connection_recreate (struct MeshConnection *c, int fwd)
680 LOG (GNUNET_ERROR_TYPE_DEBUG, "sending connection recreate\n");
684 send_connection_ack (c, GNUNET_NO);
689 * Generic connection timer management.
690 * Depending on the role of the peer in the connection will send the
691 * appropriate message (build or keepalive)
693 * @param c Conncetion to maintain.
697 connection_maintain (struct MeshConnection *c, int fwd)
699 if (MESH_TUNNEL3_SEARCHING == GMT_get_state (c->t))
701 /* TODO DHT GET with RO_BART */
706 case MESH_CONNECTION_NEW:
708 case MESH_CONNECTION_SENT:
709 connection_recreate (c, fwd);
711 case MESH_CONNECTION_READY:
712 connection_keepalive (c, fwd);
721 connection_fwd_keepalive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
723 struct MeshConnection *c = cls;
725 c->fwd_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
726 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
729 connection_maintain (c, GNUNET_YES);
730 c->fwd_maintenance_task = GNUNET_SCHEDULER_add_delayed (refresh_connection_time,
731 &connection_fwd_keepalive,
737 connection_bck_keepalive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
739 struct MeshConnection *c = cls;
741 c->bck_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
742 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
745 connection_maintain (c, GNUNET_NO);
746 c->bck_maintenance_task = GNUNET_SCHEDULER_add_delayed (refresh_connection_time,
747 &connection_bck_keepalive,
753 * @brief Re-initiate traffic on this connection if necessary.
755 * Check if there is traffic queued towards this peer
756 * and the core transmit handle is NULL (traffic was stalled).
757 * If so, call core tmt rdy.
759 * @param c Connection on which initiate traffic.
760 * @param fwd Is this about fwd traffic?
763 connection_unlock_queue (struct MeshConnection *c, int fwd)
765 struct MeshPeer *peer;
767 LOG (GNUNET_ERROR_TYPE_DEBUG,
768 "connection_unlock_queue %s on %s\n",
769 fwd ? "FWD" : "BCK", GMC_2s (c));
771 if (GMC_is_terminal (c, fwd))
773 LOG (GNUNET_ERROR_TYPE_DEBUG, " is terminal!\n");
777 peer = get_hop (c, fwd);
778 GMP_queue_unlock (peer, c);
783 * Cancel all transmissions that belong to a certain connection.
785 * If the connection is scheduled for destruction and no more messages are left,
786 * the connection will be destroyed by the continuation call.
788 * @param c Connection which to cancel. Might be destroyed during this call.
789 * @param fwd Cancel fwd traffic?
792 connection_cancel_queues (struct MeshConnection *c, int fwd)
794 struct MeshFlowControl *fc;
795 struct MeshPeer *peer;
803 fc = fwd ? &c->fwd_fc : &c->bck_fc;
804 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task)
806 GNUNET_SCHEDULER_cancel (fc->poll_task);
807 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
809 peer = get_hop (c, fwd);
810 GMP_queue_cancel (peer, c);
815 * Function called if a connection has been stalled for a while,
816 * possibly due to a missed ACK. Poll the neighbor about its ACK status.
818 * @param cls Closure (poll ctx).
819 * @param tc TaskContext.
822 connection_poll (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
824 struct MeshFlowControl *fc = cls;
825 struct GNUNET_MESH_Poll msg;
826 struct MeshConnection *c;
828 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
829 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
835 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** Polling!\n");
836 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** connection [%s]\n", GMC_2s (c));
837 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** %s\n",
838 fc == &c->fwd_fc ? "FWD" : "BCK");
840 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_POLL);
841 msg.header.size = htons (sizeof (msg));
842 msg.pid = htonl (fc->last_pid_sent);
843 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** last pid sent: %u!\n", fc->last_pid_sent);
844 GMC_send_prebuilt_message (&msg.header, c, fc == &c->fwd_fc);
845 fc->poll_time = GNUNET_TIME_STD_BACKOFF (fc->poll_time);
846 fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time,
847 &connection_poll, fc);
852 * Timeout function due to lack of keepalive/traffic from the owner.
853 * Destroys connection if called.
855 * @param cls Closure (connection to destroy).
856 * @param tc TaskContext.
859 connection_fwd_timeout (void *cls,
860 const struct GNUNET_SCHEDULER_TaskContext *tc)
862 struct MeshConnection *c = cls;
864 c->fwd_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
865 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
867 LOG (GNUNET_ERROR_TYPE_DEBUG,
868 "Connection %s[%X] FWD timed out. Destroying.\n",
872 if (GMC_is_origin (c, GNUNET_YES)) /* If local, leave. */
880 * Timeout function due to lack of keepalive/traffic from the destination.
881 * Destroys connection if called.
883 * @param cls Closure (connection to destroy).
884 * @param tc TaskContext
887 connection_bck_timeout (void *cls,
888 const struct GNUNET_SCHEDULER_TaskContext *tc)
890 struct MeshConnection *c = cls;
892 c->bck_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
893 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
896 LOG (GNUNET_ERROR_TYPE_DEBUG,
897 "Connection %s[%X] FWD timed out. Destroying.\n",
898 GMT_2s (c->t), c->id);
900 if (GMC_is_origin (c, GNUNET_NO)) /* If local, leave. */
908 * Resets the connection timeout task, some other message has done the
910 * - For the first peer on the direction this means to send
911 * a keepalive or a path confirmation message (either create or ACK).
912 * - For all other peers, this means to destroy the connection,
913 * due to lack of activity.
914 * Starts the tiemout if no timeout was running (connection just created).
916 * @param c Connection whose timeout to reset.
917 * @param fwd Is this forward?
919 * TODO use heap to improve efficiency of scheduler.
922 connection_reset_timeout (struct MeshConnection *c, int fwd)
924 GNUNET_SCHEDULER_TaskIdentifier *ti;
925 GNUNET_SCHEDULER_Task f;
927 ti = fwd ? &c->fwd_maintenance_task : &c->bck_maintenance_task;
929 if (GNUNET_SCHEDULER_NO_TASK != *ti)
930 GNUNET_SCHEDULER_cancel (*ti);
932 if (GMC_is_origin (c, fwd)) /* Endpoint */
934 f = fwd ? &connection_fwd_keepalive : &connection_bck_keepalive;
935 *ti = GNUNET_SCHEDULER_add_delayed (refresh_connection_time, f, c);
939 struct GNUNET_TIME_Relative delay;
941 delay = GNUNET_TIME_relative_multiply (refresh_connection_time, 4);
942 f = fwd ? &connection_fwd_timeout : &connection_bck_timeout;
943 *ti = GNUNET_SCHEDULER_add_delayed (delay, f, c);
949 * Add the connection to the list of both neighbors.
951 * @param c Connection.
954 register_neighbors (struct MeshConnection *c)
956 struct MeshPeer *peer;
958 peer = get_next_hop (c);
959 if (GNUNET_NO == GMP_is_neighbor (peer))
964 GMP_add_connection (peer, c);
965 peer = get_prev_hop (c);
966 if (GNUNET_NO == GMP_is_neighbor (peer))
971 GMP_add_connection (peer, c);
976 * Remove the connection from the list of both neighbors.
978 * @param c Connection.
981 unregister_neighbors (struct MeshConnection *c)
983 struct MeshPeer *peer;
985 peer = get_next_hop (c);
986 GMP_remove_connection (peer, c);
988 peer = get_prev_hop (c);
989 GMP_remove_connection (peer, c);
995 * Bind the connection to the peer and the tunnel to that peer.
997 * If the peer has no tunnel, create one. Update tunnel and connection
998 * data structres to reflect new status.
1000 * @param c Connection.
1004 add_to_peer (struct MeshConnection *c, struct MeshPeer *peer)
1006 GMP_add_tunnel (peer);
1007 c->t = GMP_get_tunnel (peer);
1008 GMT_add_connection (c->t, c);
1011 /******************************************************************************/
1012 /******************************** API ***********************************/
1013 /******************************************************************************/
1016 * Core handler for connection creation.
1018 * @param cls Closure (unused).
1019 * @param peer Sender (neighbor).
1020 * @param message Message.
1022 * @return GNUNET_OK to keep the connection open,
1023 * GNUNET_SYSERR to close it (signal serious error)
1026 GMC_handle_create (void *cls, const struct GNUNET_PeerIdentity *peer,
1027 const struct GNUNET_MessageHeader *message)
1029 struct GNUNET_MESH_ConnectionCreate *msg;
1030 struct GNUNET_PeerIdentity *id;
1031 struct GNUNET_HashCode *cid;
1032 struct MeshPeerPath *path;
1033 struct MeshPeer *dest_peer;
1034 struct MeshPeer *orig_peer;
1035 struct MeshConnection *c;
1036 unsigned int own_pos;
1040 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1041 LOG (GNUNET_ERROR_TYPE_DEBUG, "Received a connection create msg\n");
1044 size = ntohs (message->size);
1045 if (size < sizeof (struct GNUNET_MESH_ConnectionCreate))
1047 GNUNET_break_op (0);
1051 /* Calculate hops */
1052 size -= sizeof (struct GNUNET_MESH_ConnectionCreate);
1053 if (size % sizeof (struct GNUNET_PeerIdentity))
1055 GNUNET_break_op (0);
1058 size /= sizeof (struct GNUNET_PeerIdentity);
1061 GNUNET_break_op (0);
1064 LOG (GNUNET_ERROR_TYPE_DEBUG, " path has %u hops.\n", size);
1066 /* Get parameters */
1067 msg = (struct GNUNET_MESH_ConnectionCreate *) message;
1069 id = (struct GNUNET_PeerIdentity *) &msg[1];
1070 LOG (GNUNET_ERROR_TYPE_DEBUG,
1071 " connection %s (%s).\n",
1072 GNUNET_h2s (cid), GNUNET_i2s (id));
1074 /* Create connection */
1075 c = connection_get (cid);
1079 LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating path...\n");
1080 path = path_new (size);
1082 for (i = 0; i < size; i++)
1084 LOG (GNUNET_ERROR_TYPE_DEBUG, " ... adding %s\n",
1085 GNUNET_i2s (&id[i]));
1086 path->peers[i] = GNUNET_PEER_intern (&id[i]);
1087 if (path->peers[i] == myid)
1090 if (own_pos == 0 && path->peers[own_pos] != myid)
1092 /* create path: self not found in path through self */
1093 GNUNET_break_op (0);
1094 path_destroy (path);
1097 LOG (GNUNET_ERROR_TYPE_DEBUG, " Own position: %u\n", own_pos);
1098 GMP_add_path_to_all (path, GNUNET_NO);
1099 LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating connection\n");
1100 c = GMC_new (cid, NULL, path_duplicate (path), own_pos);
1103 connection_reset_timeout (c, GNUNET_YES);
1109 if (MESH_CONNECTION_NEW == c->state)
1110 connection_change_state (c, MESH_CONNECTION_SENT);
1112 /* Remember peers */
1113 dest_peer = GMP_get (&id[size - 1]);
1114 orig_peer = GMP_get (&id[0]);
1116 /* Is it a connection to us? */
1117 if (c->own_pos == size - 1)
1119 LOG (GNUNET_ERROR_TYPE_DEBUG, " It's for us!\n");
1120 GMP_add_path_to_origin (orig_peer, path, GNUNET_YES);
1122 add_to_peer (c, orig_peer);
1123 if (MESH_TUNNEL3_NEW == GMT_get_state (c->t))
1124 GMT_change_state (c->t, MESH_TUNNEL3_WAITING);
1126 send_connection_ack (c, GNUNET_NO);
1127 if (MESH_CONNECTION_SENT == c->state)
1128 connection_change_state (c, MESH_CONNECTION_ACK);
1130 /* Keep tunnel alive in direction dest->owner*/
1131 connection_reset_timeout (c, GNUNET_NO);
1135 /* It's for somebody else! Retransmit. */
1136 LOG (GNUNET_ERROR_TYPE_DEBUG, " Retransmitting.\n");
1137 GMP_add_path (dest_peer, path_duplicate (path), GNUNET_NO);
1138 GMP_add_path_to_origin (orig_peer, path, GNUNET_NO);
1139 GMC_send_prebuilt_message (message, c, GNUNET_YES);
1146 * Core handler for path confirmations.
1148 * @param cls closure
1149 * @param message message
1150 * @param peer peer identity this notification is about
1152 * @return GNUNET_OK to keep the connection open,
1153 * GNUNET_SYSERR to close it (signal serious error)
1156 GMC_handle_confirm (void *cls, const struct GNUNET_PeerIdentity *peer,
1157 const struct GNUNET_MessageHeader *message)
1159 struct GNUNET_MESH_ConnectionACK *msg;
1160 struct MeshConnection *c;
1161 struct MeshPeerPath *p;
1162 struct MeshPeer *pi;
1165 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1166 LOG (GNUNET_ERROR_TYPE_DEBUG, "Received a connection ACK msg\n");
1167 msg = (struct GNUNET_MESH_ConnectionACK *) message;
1168 LOG (GNUNET_ERROR_TYPE_DEBUG, " on connection %s\n",
1169 GNUNET_h2s (&msg->cid));
1170 c = connection_get (&msg->cid);
1173 GNUNET_STATISTICS_update (stats, "# control on unknown connection",
1175 LOG (GNUNET_ERROR_TYPE_DEBUG, " don't know the connection!\n");
1180 LOG (GNUNET_ERROR_TYPE_DEBUG, " via peer %s\n",
1182 pi = GMP_get (peer);
1183 if (get_next_hop (c) == pi)
1185 LOG (GNUNET_ERROR_TYPE_DEBUG, " SYNACK\n");
1187 if (MESH_CONNECTION_SENT == c->state)
1188 connection_change_state (c, MESH_CONNECTION_ACK);
1190 else if (get_prev_hop (c) == pi)
1192 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK\n");
1194 connection_change_state (c, MESH_CONNECTION_READY);
1198 GNUNET_break_op (0);
1201 connection_reset_timeout (c, fwd);
1203 /* Add path to peers? */
1207 GMP_add_path_to_all (p, GNUNET_YES);
1214 /* Message for us as creator? */
1215 if (GMC_is_origin (c, GNUNET_YES))
1217 LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection (SYN)ACK for us!\n");
1218 connection_change_state (c, MESH_CONNECTION_READY);
1219 if (MESH_TUNNEL3_WAITING == GMT_get_state (c->t))
1220 GMT_change_state (c->t, MESH_TUNNEL3_READY);
1221 send_connection_ack (c, GNUNET_YES);
1225 /* Message for us as destination? */
1226 if (GMC_is_terminal (c, GNUNET_YES))
1228 LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection ACK for us!\n");
1229 connection_change_state (c, MESH_CONNECTION_READY);
1230 if (MESH_TUNNEL3_WAITING == GMT_get_state (c->t))
1231 GMT_change_state (c->t, MESH_TUNNEL3_READY);
1235 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
1236 GMC_send_prebuilt_message (message, c, fwd);
1242 * Core handler for notifications of broken paths
1244 * @param cls Closure (unused).
1245 * @param id Peer identity of sending neighbor.
1246 * @param message Message.
1248 * @return GNUNET_OK to keep the connection open,
1249 * GNUNET_SYSERR to close it (signal serious error)
1252 GMC_handle_broken (void* cls,
1253 const struct GNUNET_PeerIdentity* id,
1254 const struct GNUNET_MessageHeader* message)
1256 struct GNUNET_MESH_ConnectionBroken *msg;
1257 struct MeshConnection *c;
1260 LOG (GNUNET_ERROR_TYPE_DEBUG,
1261 "Received a CONNECTION BROKEN msg from %s\n", GNUNET_i2s (id));
1262 msg = (struct GNUNET_MESH_ConnectionBroken *) message;
1263 LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n",
1264 GNUNET_i2s (&msg->peer1));
1265 LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n",
1266 GNUNET_i2s (&msg->peer2));
1267 c = connection_get (&msg->cid);
1270 GNUNET_break_op (0);
1274 fwd = is_fwd (c, id);
1275 connection_cancel_queues (c, !fwd);
1276 if (GMC_is_terminal (c, fwd))
1278 if (0 < c->pending_messages)
1279 c->destroy = GNUNET_YES;
1285 GMC_send_prebuilt_message (message, c, fwd);
1286 c->destroy = GNUNET_YES;
1295 * Core handler for tunnel destruction
1297 * @param cls Closure (unused).
1298 * @param peer Peer identity of sending neighbor.
1299 * @param message Message.
1301 * @return GNUNET_OK to keep the connection open,
1302 * GNUNET_SYSERR to close it (signal serious error)
1305 GMC_handle_destroy (void *cls, const struct GNUNET_PeerIdentity *peer,
1306 const struct GNUNET_MessageHeader *message)
1308 struct GNUNET_MESH_ConnectionDestroy *msg;
1309 struct MeshConnection *c;
1312 msg = (struct GNUNET_MESH_ConnectionDestroy *) message;
1313 LOG (GNUNET_ERROR_TYPE_DEBUG,
1314 "Got a CONNECTION DESTROY message from %s\n",
1316 LOG (GNUNET_ERROR_TYPE_DEBUG,
1317 " for connection %s\n",
1318 GNUNET_h2s (&msg->cid));
1319 c = connection_get (&msg->cid);
1322 /* Probably already got the message from another path,
1323 * destroyed the tunnel and retransmitted to children.
1326 GNUNET_STATISTICS_update (stats, "# control on unknown tunnel",
1330 fwd = is_fwd (c, peer);
1331 if (GNUNET_SYSERR == fwd)
1333 GNUNET_break_op (0);
1336 GMC_send_prebuilt_message (message, c, fwd);
1337 c->destroy = GNUNET_YES;
1343 * Generic handler for mesh network encrypted traffic.
1345 * @param peer Peer identity this notification is about.
1346 * @param msg Encrypted message.
1348 * @return GNUNET_OK to keep the connection open,
1349 * GNUNET_SYSERR to close it (signal serious error)
1352 handle_mesh_encrypted (const struct GNUNET_PeerIdentity *peer,
1353 const struct GNUNET_MESH_Encrypted *msg)
1355 struct MeshConnection *c;
1356 struct MeshPeer *neighbor;
1357 struct MeshFlowControl *fc;
1358 GNUNET_PEER_Id peer_id;
1366 size = ntohs (msg->header.size);
1368 sizeof (struct GNUNET_MESH_Encrypted) +
1369 sizeof (struct GNUNET_MessageHeader))
1371 GNUNET_break_op (0);
1374 type = ntohs (msg->header.type);
1375 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1376 LOG (GNUNET_ERROR_TYPE_DEBUG, "got a %s message from %s\n",
1377 GNUNET_MESH_DEBUG_M2S (type), GNUNET_i2s (peer));
1379 /* Check connection */
1380 c = connection_get (&msg->cid);
1383 GNUNET_STATISTICS_update (stats, "# unknown connection", 1, GNUNET_NO);
1384 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING connection unknown\n");
1388 /* Check if origin is as expected */
1389 neighbor = get_prev_hop (c);
1390 peer_id = GNUNET_PEER_search (peer);
1391 if (peer_id == GMP_get_short_id (neighbor))
1397 neighbor = get_next_hop (c);
1398 if (peer_id == GMP_get_short_id (neighbor))
1404 /* Unexpected peer sending traffic on a connection. */
1405 GNUNET_break_op (0);
1411 fc = fwd ? &c->bck_fc : &c->fwd_fc;
1412 pid = ntohl (msg->pid);
1413 if (GMC_is_pid_bigger (pid, fc->last_ack_sent))
1415 GNUNET_STATISTICS_update (stats, "# unsolicited message", 1, GNUNET_NO);
1416 LOG (GNUNET_ERROR_TYPE_DEBUG,
1417 "WARNING Received PID %u, (prev %u), ACK %u\n",
1418 pid, fc->last_pid_recv, fc->last_ack_sent);
1421 if (GNUNET_NO == GMC_is_pid_bigger (pid, fc->last_pid_recv))
1423 GNUNET_STATISTICS_update (stats, "# duplicate PID", 1, GNUNET_NO);
1424 LOG (GNUNET_ERROR_TYPE_DEBUG,
1425 " Pid %u not expected (%u+), dropping!\n",
1426 pid, fc->last_pid_recv + 1);
1429 if (MESH_CONNECTION_SENT == c->state || MESH_CONNECTION_ACK == c->state)
1430 connection_change_state (c, MESH_CONNECTION_READY);
1431 connection_reset_timeout (c, fwd);
1432 fc->last_pid_recv = pid;
1434 /* Is this message for us? */
1435 if (GMC_is_terminal (c, fwd))
1437 /* TODO signature verification */
1438 LOG (GNUNET_ERROR_TYPE_DEBUG, " message for us!\n");
1439 GNUNET_STATISTICS_update (stats, "# messages received", 1, GNUNET_NO);
1446 fc->last_pid_recv = pid;
1447 GMT_handle_encrypted (c->t, msg);
1448 GMC_send_ack (c, fwd);
1452 /* Message not for us: forward to next hop */
1453 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
1454 ttl = ntohl (msg->ttl);
1455 LOG (GNUNET_ERROR_TYPE_DEBUG, " ttl: %u\n", ttl);
1458 GNUNET_STATISTICS_update (stats, "# TTL drops", 1, GNUNET_NO);
1459 LOG (GNUNET_ERROR_TYPE_WARNING, " TTL is 0, DROPPING!\n");
1460 GMC_send_ack (c, fwd);
1463 GNUNET_STATISTICS_update (stats, "# messages forwarded", 1, GNUNET_NO);
1465 GMC_send_prebuilt_message (&msg->header, c, fwd);
1471 * Generic handler for mesh network encrypted traffic.
1473 * @param peer Peer identity this notification is about.
1474 * @param msg Encrypted message.
1476 * @return GNUNET_OK to keep the connection open,
1477 * GNUNET_SYSERR to close it (signal serious error)
1480 handle_mesh_kx (const struct GNUNET_PeerIdentity *peer,
1481 const struct GNUNET_MESH_KX *msg)
1483 struct MeshConnection *c;
1484 struct MeshPeer *neighbor;
1485 GNUNET_PEER_Id peer_id;
1491 size = ntohs (msg->header.size);
1493 sizeof (struct GNUNET_MESH_Encrypted) +
1494 sizeof (struct GNUNET_MessageHeader))
1496 GNUNET_break_op (0);
1499 type = ntohs (msg->header.type);
1500 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1501 LOG (GNUNET_ERROR_TYPE_DEBUG, "got a %s message from %s\n",
1502 GNUNET_MESH_DEBUG_M2S (type), GNUNET_i2s (peer));
1504 /* Check connection */
1505 c = connection_get (&msg->cid);
1508 GNUNET_STATISTICS_update (stats, "# unknown connection", 1, GNUNET_NO);
1509 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING connection unknown\n");
1513 /* Check if origin is as expected */
1514 neighbor = get_prev_hop (c);
1515 peer_id = GNUNET_PEER_search (peer);
1516 if (peer_id == GMP_get_short_id (neighbor))
1522 neighbor = get_next_hop (c);
1523 if (peer_id == GMP_get_short_id (neighbor))
1529 /* Unexpected peer sending traffic on a connection. */
1530 GNUNET_break_op (0);
1535 /* Count as connection confirmation. */
1536 if (MESH_CONNECTION_SENT == c->state || MESH_CONNECTION_ACK == c->state)
1537 connection_change_state (c, MESH_CONNECTION_READY);
1538 connection_reset_timeout (c, fwd);
1541 if (MESH_TUNNEL3_WAITING == GMT_get_state (c->t))
1542 GMT_change_state (c->t, MESH_TUNNEL3_READY);
1545 /* Is this message for us? */
1546 if (GMC_is_terminal (c, fwd))
1548 LOG (GNUNET_ERROR_TYPE_DEBUG, " message for us!\n");
1549 GNUNET_STATISTICS_update (stats, "# messages received", 1, GNUNET_NO);
1555 GMT_handle_kx (c->t, &msg[1].header);
1559 /* Message not for us: forward to next hop */
1560 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
1561 GNUNET_STATISTICS_update (stats, "# messages forwarded", 1, GNUNET_NO);
1563 GMC_send_prebuilt_message (&msg->header, c, fwd);
1570 * Core handler for encrypted mesh network traffic (channel mgmt, data).
1572 * @param cls Closure (unused).
1573 * @param message Message received.
1574 * @param peer Peer who sent the message.
1576 * @return GNUNET_OK to keep the connection open,
1577 * GNUNET_SYSERR to close it (signal serious error)
1580 GMC_handle_encrypted (void *cls, const struct GNUNET_PeerIdentity *peer,
1581 const struct GNUNET_MessageHeader *message)
1583 return handle_mesh_encrypted (peer,
1584 (struct GNUNET_MESH_Encrypted *)message);
1589 * Core handler for key exchange traffic (ephemeral key, ping, pong).
1591 * @param cls Closure (unused).
1592 * @param message Message received.
1593 * @param peer Peer who sent the message.
1595 * @return GNUNET_OK to keep the connection open,
1596 * GNUNET_SYSERR to close it (signal serious error)
1599 GMC_handle_kx (void *cls, const struct GNUNET_PeerIdentity *peer,
1600 const struct GNUNET_MessageHeader *message)
1602 return handle_mesh_kx (peer,
1603 (struct GNUNET_MESH_KX *) message);
1608 * Core handler for mesh network traffic point-to-point acks.
1610 * @param cls closure
1611 * @param message message
1612 * @param peer peer identity this notification is about
1614 * @return GNUNET_OK to keep the connection open,
1615 * GNUNET_SYSERR to close it (signal serious error)
1618 GMC_handle_ack (void *cls, const struct GNUNET_PeerIdentity *peer,
1619 const struct GNUNET_MessageHeader *message)
1621 struct GNUNET_MESH_ACK *msg;
1622 struct MeshConnection *c;
1623 struct MeshFlowControl *fc;
1628 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1629 LOG (GNUNET_ERROR_TYPE_DEBUG, "Got an ACK packet from %s!\n",
1631 msg = (struct GNUNET_MESH_ACK *) message;
1633 c = connection_get (&msg->cid);
1637 GNUNET_STATISTICS_update (stats, "# ack on unknown connection", 1,
1642 /* Is this a forward or backward ACK? */
1643 id = GNUNET_PEER_search (peer);
1644 if (GMP_get_short_id (get_next_hop (c)) == id)
1646 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD ACK\n");
1650 else if (GMP_get_short_id (get_prev_hop (c)) == id)
1652 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK ACK\n");
1658 GNUNET_break_op (0);
1662 ack = ntohl (msg->ack);
1663 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK %u (was %u)\n",
1664 ack, fc->last_ack_recv);
1665 if (GMC_is_pid_bigger (ack, fc->last_ack_recv))
1666 fc->last_ack_recv = ack;
1668 /* Cancel polling if the ACK is big enough. */
1669 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task &&
1670 GMC_is_pid_bigger (fc->last_ack_recv, fc->last_pid_sent))
1672 LOG (GNUNET_ERROR_TYPE_DEBUG, " Cancel poll\n");
1673 GNUNET_SCHEDULER_cancel (fc->poll_task);
1674 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
1675 fc->poll_time = GNUNET_TIME_UNIT_SECONDS;
1678 connection_unlock_queue (c, fwd);
1685 * Core handler for mesh network traffic point-to-point ack polls.
1687 * @param cls closure
1688 * @param message message
1689 * @param peer peer identity this notification is about
1691 * @return GNUNET_OK to keep the connection open,
1692 * GNUNET_SYSERR to close it (signal serious error)
1695 GMC_handle_poll (void *cls, const struct GNUNET_PeerIdentity *peer,
1696 const struct GNUNET_MessageHeader *message)
1698 struct GNUNET_MESH_Poll *msg;
1699 struct MeshConnection *c;
1700 struct MeshFlowControl *fc;
1705 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1706 LOG (GNUNET_ERROR_TYPE_DEBUG,
1707 "Got a POLL packet from %s!\n",
1710 msg = (struct GNUNET_MESH_Poll *) message;
1712 c = connection_get (&msg->cid);
1716 GNUNET_STATISTICS_update (stats, "# poll on unknown connection", 1,
1718 GNUNET_break_op (0);
1722 /* Is this a forward or backward ACK?
1723 * Note: a poll should never be needed in a loopback case,
1724 * since there is no possiblility of packet loss there, so
1725 * this way of discerining FWD/BCK should not be a problem.
1727 id = GNUNET_PEER_search (peer);
1728 if (GMP_get_short_id (get_next_hop (c)) == id)
1730 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD FC\n");
1733 else if (GMP_get_short_id (get_prev_hop (c)) == id)
1735 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK FC\n");
1740 GNUNET_break_op (0);
1744 pid = ntohl (msg->pid);
1745 LOG (GNUNET_ERROR_TYPE_DEBUG, " PID %u, OLD %u\n", pid, fc->last_pid_recv);
1746 fc->last_pid_recv = pid;
1747 fwd = fc == &c->bck_fc;
1748 GMC_send_ack (c, fwd);
1755 * Core handler for mesh keepalives.
1757 * @param cls closure
1758 * @param message message
1759 * @param peer peer identity this notification is about
1760 * @return GNUNET_OK to keep the connection open,
1761 * GNUNET_SYSERR to close it (signal serious error)
1763 * TODO: Check who we got this from, to validate route.
1766 GMC_handle_keepalive (void *cls, const struct GNUNET_PeerIdentity *peer,
1767 const struct GNUNET_MessageHeader *message)
1769 struct GNUNET_MESH_ConnectionKeepAlive *msg;
1770 struct MeshConnection *c;
1771 struct MeshPeer *neighbor;
1774 msg = (struct GNUNET_MESH_ConnectionKeepAlive *) message;
1775 LOG (GNUNET_ERROR_TYPE_DEBUG, "got a keepalive packet from %s\n",
1778 c = connection_get (&msg->cid);
1781 GNUNET_STATISTICS_update (stats, "# keepalive on unknown connection", 1,
1786 fwd = GNUNET_MESSAGE_TYPE_MESH_FWD_KEEPALIVE == ntohs (message->type) ?
1787 GNUNET_YES : GNUNET_NO;
1789 /* Check if origin is as expected */
1790 neighbor = get_hop (c, fwd);
1791 if (GNUNET_PEER_search (peer) != GMP_get_short_id (neighbor))
1793 GNUNET_break_op (0);
1797 connection_change_state (c, MESH_CONNECTION_READY);
1798 connection_reset_timeout (c, fwd);
1800 if (GMC_is_terminal (c, fwd))
1803 GNUNET_STATISTICS_update (stats, "# keepalives forwarded", 1, GNUNET_NO);
1804 GMC_send_prebuilt_message (message, c, fwd);
1811 * Send an ACK on the appropriate connection/channel, depending on
1812 * the direction and the position of the peer.
1814 * @param c Which connection to send the hop-by-hop ACK.
1815 * @param fwd Is this a fwd ACK? (will go dest->root)
1818 GMC_send_ack (struct MeshConnection *c, int fwd)
1820 unsigned int buffer;
1822 LOG (GNUNET_ERROR_TYPE_DEBUG,
1823 "GMC send %s ACK on %s\n",
1824 fwd ? "FWD" : "BCK", GMC_2s (c));
1832 /* Get available buffer space */
1833 if (GMC_is_terminal (c, fwd))
1835 LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from all channels\n");
1836 buffer = GMT_get_channels_buffer (c->t);
1840 LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from one connection\n");
1841 buffer = GMC_get_buffer (c, fwd);
1843 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer available: %u\n", buffer);
1845 /* Send available buffer space */
1846 if (GMC_is_origin (c, fwd))
1848 GNUNET_assert (NULL != c->t);
1849 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channels...\n");
1852 LOG (GNUNET_ERROR_TYPE_DEBUG, " really sending!\n");
1853 GMT_unchoke_channels (c->t);
1858 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on connection\n");
1859 send_ack (c, buffer, fwd);
1865 * Initialize the connections subsystem
1867 * @param c Configuration handle.
1870 GMC_init (const struct GNUNET_CONFIGURATION_Handle *c)
1872 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
1874 GNUNET_CONFIGURATION_get_value_number (c, "MESH", "MAX_MSGS_QUEUE",
1877 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
1878 "MESH", "MAX_MSGS_QUEUE", "MISSING");
1879 GNUNET_SCHEDULER_shutdown ();
1884 GNUNET_CONFIGURATION_get_value_number (c, "MESH", "MAX_CONNECTIONS",
1887 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
1888 "MESH", "MAX_CONNECTIONS", "MISSING");
1889 GNUNET_SCHEDULER_shutdown ();
1894 GNUNET_CONFIGURATION_get_value_time (c, "MESH", "REFRESH_CONNECTION_TIME",
1895 &refresh_connection_time))
1897 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
1898 "MESH", "REFRESH_CONNECTION_TIME", "MISSING");
1899 GNUNET_SCHEDULER_shutdown ();
1902 connections = GNUNET_CONTAINER_multihashmap_create (1024, GNUNET_YES);
1906 * Shut down the connections subsystem.
1911 GNUNET_CONTAINER_multihashmap_destroy (connections);
1915 struct MeshConnection *
1916 GMC_new (const struct GNUNET_HashCode *cid,
1917 struct MeshTunnel3 *t,
1918 struct MeshPeerPath *p,
1919 unsigned int own_pos)
1921 struct MeshConnection *c;
1923 c = GNUNET_new (struct MeshConnection);
1925 GNUNET_CONTAINER_multihashmap_put (connections, &c->id, c,
1926 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST);
1927 fc_init (&c->fwd_fc);
1928 fc_init (&c->bck_fc);
1933 if (own_pos > p->length - 1)
1939 c->own_pos = own_pos;
1944 c->fwd_maintenance_task =
1945 GNUNET_SCHEDULER_add_delayed (refresh_connection_time,
1946 &connection_fwd_keepalive, c);
1948 register_neighbors (c);
1954 GMC_destroy (struct MeshConnection *c)
1959 if (2 == c->destroy) /* cancel queues -> GMP_queue_cancel -> q_destroy -> */
1960 return; /* -> message_sent -> GMC_destroy. Don't loop. */
1963 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying connection %s\n", GMC_2s (c));
1965 /* Cancel all traffic */
1966 connection_cancel_queues (c, GNUNET_YES);
1967 connection_cancel_queues (c, GNUNET_NO);
1969 /* Cancel maintainance task (keepalive/timeout) */
1970 if (GNUNET_SCHEDULER_NO_TASK != c->fwd_maintenance_task)
1971 GNUNET_SCHEDULER_cancel (c->fwd_maintenance_task);
1972 if (GNUNET_SCHEDULER_NO_TASK != c->bck_maintenance_task)
1973 GNUNET_SCHEDULER_cancel (c->bck_maintenance_task);
1975 /* Unregister from neighbors */
1976 unregister_neighbors (c);
1979 GNUNET_STATISTICS_update (stats, "# connections", -1, GNUNET_NO);
1981 GMT_remove_connection (c->t, c);
1983 if (GNUNET_NO == GMC_is_origin (c, GNUNET_YES))
1984 path_destroy (c->path);
1990 * Get the connection ID.
1992 * @param c Connection to get the ID from.
1994 * @return ID of the connection.
1996 const struct GNUNET_HashCode *
1997 GMC_get_id (const struct MeshConnection *c)
2004 * Get the connection path.
2006 * @param c Connection to get the path from.
2008 * @return path used by the connection.
2010 const struct MeshPeerPath *
2011 GMC_get_path (const struct MeshConnection *c)
2018 * Get the connection state.
2020 * @param c Connection to get the state from.
2022 * @return state of the connection.
2024 enum MeshConnectionState
2025 GMC_get_state (const struct MeshConnection *c)
2031 * Get the connection tunnel.
2033 * @param c Connection to get the tunnel from.
2035 * @return tunnel of the connection.
2037 struct MeshTunnel3 *
2038 GMC_get_tunnel (const struct MeshConnection *c)
2045 * Get free buffer space in a connection.
2047 * @param c Connection.
2048 * @param fwd Is query about FWD traffic?
2050 * @return Free buffer space [0 - max_msgs_queue/max_connections]
2053 GMC_get_buffer (struct MeshConnection *c, int fwd)
2055 struct MeshFlowControl *fc;
2057 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2059 return (fc->queue_max - fc->queue_n);
2063 * Get how many messages have we allowed to send to us from a direction.
2065 * @param c Connection.
2066 * @param fwd Are we asking about traffic from FWD (BCK messages)?
2068 * @return last_ack_sent - last_pid_recv
2071 GMC_get_allowed (struct MeshConnection *c, int fwd)
2073 struct MeshFlowControl *fc;
2075 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2076 if (GMC_is_pid_bigger(fc->last_pid_recv, fc->last_ack_sent))
2080 return (fc->last_ack_sent - fc->last_pid_recv);
2084 * Get messages queued in a connection.
2086 * @param c Connection.
2087 * @param fwd Is query about FWD traffic?
2089 * @return Number of messages queued.
2092 GMC_get_qn (struct MeshConnection *c, int fwd)
2094 struct MeshFlowControl *fc;
2096 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2103 * Allow the connection to advertise a buffer of the given size.
2105 * The connection will send an @c fwd ACK message (so: in direction !fwd)
2106 * allowing up to last_pid_recv + buffer.
2108 * @param c Connection.
2109 * @param buffer How many more messages the connection can accept.
2110 * @param fwd Is this about FWD traffic? (The ack will go dest->root).
2113 GMC_allow (struct MeshConnection *c, unsigned int buffer, int fwd)
2115 send_ack (c, buffer, fwd);
2120 * Notify other peers on a connection of a broken link. Mark connections
2121 * to destroy after all traffic has been sent.
2123 * @param c Connection on which there has been a disconnection.
2124 * @param peer Peer that disconnected.
2127 GMC_notify_broken (struct MeshConnection *c,
2128 struct MeshPeer *peer)
2132 fwd = peer == get_prev_hop (c);
2134 if (GNUNET_YES == GMC_is_terminal (c, fwd))
2136 /* Local shutdown, no one to notify about this. */
2140 if (GNUNET_NO == c->destroy)
2141 send_broken (c, &my_full_id, GMP_get_id (peer), fwd);
2143 /* Connection will have at least one pending message
2144 * (the one we just scheduled), so no point in checking whether to
2145 * destroy immediately. */
2146 c->destroy = GNUNET_YES;
2149 * Cancel all queues, if no message is left, connection will be destroyed.
2151 connection_cancel_queues (c, !fwd);
2158 * Is this peer the first one on the connection?
2160 * @param c Connection.
2161 * @param fwd Is this about fwd traffic?
2163 * @return #GNUNET_YES if origin, #GNUNET_NO if relay/terminal.
2166 GMC_is_origin (struct MeshConnection *c, int fwd)
2168 if (!fwd && c->path->length - 1 == c->own_pos )
2170 if (fwd && 0 == c->own_pos)
2177 * Is this peer the last one on the connection?
2179 * @param c Connection.
2180 * @param fwd Is this about fwd traffic?
2181 * Note that the ROOT is the terminal for BCK traffic!
2183 * @return #GNUNET_YES if terminal, #GNUNET_NO if relay/origin.
2186 GMC_is_terminal (struct MeshConnection *c, int fwd)
2188 return GMC_is_origin (c, !fwd);
2193 * See if we are allowed to send by the next hop in the given direction.
2195 * @param c Connection.
2196 * @param fwd Is this about fwd traffic?
2198 * @return #GNUNET_YES in case it's OK to send.
2201 GMC_is_sendable (struct MeshConnection *c, int fwd)
2203 struct MeshFlowControl *fc;
2205 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2206 if (GMC_is_pid_bigger (fc->last_ack_recv, fc->last_pid_sent))
2212 * Sends an already built message on a connection, properly registering
2213 * all used resources.
2215 * @param message Message to send. Function makes a copy of it.
2216 * If message is not hop-by-hop, decrements TTL of copy.
2217 * @param c Connection on which this message is transmitted.
2218 * @param fwd Is this a fwd message?
2221 GMC_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2222 struct MeshConnection *c,
2225 struct MeshFlowControl *fc;
2231 size = ntohs (message->size);
2232 data = GNUNET_malloc (size);
2233 memcpy (data, message, size);
2234 type = ntohs (message->type);
2235 LOG (GNUNET_ERROR_TYPE_DEBUG, "Send %s (%u bytes) on connection %s\n",
2236 GNUNET_MESH_DEBUG_M2S (type), size, GMC_2s (c));
2238 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2239 droppable = GNUNET_YES;
2242 struct GNUNET_MESH_Encrypted *emsg;
2243 struct GNUNET_MESH_KX *kmsg;
2244 struct GNUNET_MESH_ACK *amsg;
2245 struct GNUNET_MESH_Poll *pmsg;
2246 struct GNUNET_MESH_ConnectionDestroy *dmsg;
2247 struct GNUNET_MESH_ConnectionBroken *bmsg;
2250 case GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED:
2251 emsg = (struct GNUNET_MESH_Encrypted *) data;
2252 ttl = ntohl (emsg->ttl);
2255 GNUNET_break_op (0);
2259 emsg->ttl = htonl (ttl - 1);
2260 emsg->pid = htonl (fwd ? c->fwd_fc.next_pid++ : c->bck_fc.next_pid++);
2261 LOG (GNUNET_ERROR_TYPE_DEBUG, " Q_N+ %p %u\n", fc, fc->queue_n);
2263 LOG (GNUNET_ERROR_TYPE_DEBUG, "pid %u\n", ntohl (emsg->pid));
2264 LOG (GNUNET_ERROR_TYPE_DEBUG, "last pid %u\n", fc->last_pid_sent);
2265 LOG (GNUNET_ERROR_TYPE_DEBUG, " ack %u\n", fc->last_ack_recv);
2266 if (GMC_is_pid_bigger (fc->last_pid_sent + 1, fc->last_ack_recv))
2268 GMC_start_poll (c, fwd);
2272 case GNUNET_MESSAGE_TYPE_MESH_KX:
2273 kmsg = (struct GNUNET_MESH_KX *) data;
2277 case GNUNET_MESSAGE_TYPE_MESH_ACK:
2278 amsg = (struct GNUNET_MESH_ACK *) data;
2280 LOG (GNUNET_ERROR_TYPE_DEBUG, " ack %u\n", ntohl (amsg->ack));
2281 droppable = GNUNET_NO;
2284 case GNUNET_MESSAGE_TYPE_MESH_POLL:
2285 pmsg = (struct GNUNET_MESH_Poll *) data;
2287 LOG (GNUNET_ERROR_TYPE_DEBUG, " poll %u\n", ntohl (pmsg->pid));
2288 droppable = GNUNET_NO;
2291 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_DESTROY:
2292 dmsg = (struct GNUNET_MESH_ConnectionDestroy *) data;
2297 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_BROKEN:
2298 bmsg = (struct GNUNET_MESH_ConnectionBroken *) data;
2303 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_CREATE:
2304 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_ACK:
2311 if (fc->queue_n > fc->queue_max && droppable)
2313 GNUNET_STATISTICS_update (stats, "# messages dropped (buffer full)",
2316 LOG (GNUNET_ERROR_TYPE_DEBUG,
2317 "queue full: %u/%u\n",
2318 fc->queue_n, fc->queue_max);
2319 if (GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED == type)
2321 return; /* Drop this message */
2324 LOG (GNUNET_ERROR_TYPE_DEBUG, " C_P+ %p %u\n", c, c->pending_messages);
2325 c->pending_messages++;
2327 GMP_queue_add (get_hop (c, fwd), data, type, size, c, fwd,
2328 &message_sent, NULL);
2333 * Sends a CREATE CONNECTION message for a path to a peer.
2334 * Changes the connection and tunnel states if necessary.
2336 * @param connection Connection to create.
2339 GMC_send_create (struct MeshConnection *connection)
2341 enum MeshTunnel3State state;
2344 size = sizeof (struct GNUNET_MESH_ConnectionCreate);
2345 size += connection->path->length * sizeof (struct GNUNET_PeerIdentity);
2346 LOG (GNUNET_ERROR_TYPE_DEBUG, "Send connection create\n");
2347 GMP_queue_add (get_next_hop (connection), NULL,
2348 GNUNET_MESSAGE_TYPE_MESH_CONNECTION_CREATE,
2349 size, connection, GNUNET_YES, &message_sent, NULL);
2350 LOG (GNUNET_ERROR_TYPE_DEBUG, " C_P+ %p %u (create)\n",
2351 connection, connection->pending_messages);
2352 connection->pending_messages++;
2353 state = GMT_get_state (connection->t);
2354 if (MESH_TUNNEL3_SEARCHING == state || MESH_TUNNEL3_NEW == state)
2355 GMT_change_state (connection->t, MESH_TUNNEL3_WAITING);
2356 if (MESH_CONNECTION_NEW == connection->state)
2357 connection_change_state (connection, MESH_CONNECTION_SENT);
2362 * Send a message to all peers in this connection that the connection
2363 * is no longer valid.
2365 * If some peer should not receive the message, it should be zero'ed out
2366 * before calling this function.
2368 * @param c The connection whose peers to notify.
2371 GMC_send_destroy (struct MeshConnection *c)
2373 struct GNUNET_MESH_ConnectionDestroy msg;
2375 if (GNUNET_YES == c->destroy)
2378 msg.header.size = htons (sizeof (msg));
2379 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CONNECTION_DESTROY);;
2381 LOG (GNUNET_ERROR_TYPE_DEBUG,
2382 " sending connection destroy for connection %s\n",
2385 if (GNUNET_NO == GMC_is_terminal (c, GNUNET_YES))
2386 GMC_send_prebuilt_message (&msg.header, c, GNUNET_YES);
2387 if (GNUNET_NO == GMC_is_terminal (c, GNUNET_NO))
2388 GMC_send_prebuilt_message (&msg.header, c, GNUNET_NO);
2389 c->destroy = GNUNET_YES;
2394 * @brief Start a polling timer for the connection.
2396 * When a neighbor does not accept more traffic on the connection it could be
2397 * caused by a simple congestion or by a lost ACK. Polling enables to check
2398 * for the lastest ACK status for a connection.
2400 * @param c Connection.
2401 * @param fwd Should we poll in the FWD direction?
2404 GMC_start_poll (struct MeshConnection *c, int fwd)
2406 struct MeshFlowControl *fc;
2408 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2409 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task)
2413 fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time,
2420 * @brief Stop polling a connection for ACKs.
2422 * Once we have enough ACKs for future traffic, polls are no longer necessary.
2424 * @param c Connection.
2425 * @param fwd Should we stop the poll in the FWD direction?
2428 GMC_stop_poll (struct MeshConnection *c, int fwd)
2430 struct MeshFlowControl *fc;
2432 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2433 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task)
2435 GNUNET_SCHEDULER_cancel (fc->poll_task);
2436 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
2441 * Get a (static) string for a connection.
2443 * @param c Connection.
2446 GMC_2s (struct MeshConnection *c)
2450 static char buf[128];
2452 sprintf (buf, "%s (->%s)", GNUNET_h2s (&c->id), GMT_2s (c->t));
2455 return GNUNET_h2s (&c->id);