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
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file 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.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;
109 * Queued poll message, to cancel if not necessary anymore (got ACK).
111 struct MeshConnectionQueue *poll_msg;
114 * Queued poll message, to cancel if not necessary anymore (got ACK).
116 struct MeshConnectionQueue *ack_msg;
120 * Keep a record of the last messages sent on this connection.
122 struct MeshConnectionPerformance
125 * Circular buffer for storing measurements.
127 double usecsperbyte[AVG_MSGS];
130 * Running average of @c usecsperbyte.
135 * How many values of @c usecsperbyte are valid.
140 * Index of the next "free" position in @c usecsperbyte.
147 * Struct containing all information regarding a connection to a peer.
149 struct MeshConnection
152 * Tunnel this connection is part of.
154 struct MeshTunnel3 *t;
157 * Flow control information for traffic fwd.
159 struct MeshFlowControl fwd_fc;
162 * Flow control information for traffic bck.
164 struct MeshFlowControl bck_fc;
167 * Measure connection performance on the endpoint.
169 struct MeshConnectionPerformance *perf;
172 * ID of the connection.
174 struct GNUNET_HashCode id;
177 * State of the connection.
179 enum MeshConnectionState state;
182 * Path being used for the tunnel.
184 struct MeshPeerPath *path;
187 * Position of the local peer in the path.
189 unsigned int own_pos;
192 * Task to keep the used paths alive at the owner,
193 * time tunnel out on all the other peers.
195 GNUNET_SCHEDULER_TaskIdentifier fwd_maintenance_task;
198 * Task to keep the used paths alive at the destination,
199 * time tunnel out on all the other peers.
201 GNUNET_SCHEDULER_TaskIdentifier bck_maintenance_task;
204 * Pending message count.
206 int pending_messages;
209 * Destroy flag: if true, destroy on last message.
215 * Handle for messages queued but not yet sent.
217 struct MeshConnectionQueue
219 struct MeshPeerQueue *q;
224 /******************************************************************************/
225 /******************************* GLOBALS ***********************************/
226 /******************************************************************************/
229 * Global handle to the statistics service.
231 extern struct GNUNET_STATISTICS_Handle *stats;
234 * Local peer own ID (memory efficient handle).
236 extern GNUNET_PEER_Id myid;
239 * Local peer own ID (full value).
241 extern struct GNUNET_PeerIdentity my_full_id;
244 * Connections known, indexed by cid (MeshConnection).
246 static struct GNUNET_CONTAINER_MultiHashMap *connections;
249 * How many connections are we willing to maintain.
250 * Local connections are always allowed, even if there are more connections than max.
252 static unsigned long long max_connections;
255 * How many messages *in total* are we willing to queue, divide by number of
256 * connections to get connection queue size.
258 static unsigned long long max_msgs_queue;
261 * How often to send path keepalives. Paths timeout after 4 missed.
263 static struct GNUNET_TIME_Relative refresh_connection_time;
266 * How often to send path create / ACKs.
268 static struct GNUNET_TIME_Relative create_connection_time;
271 /******************************************************************************/
272 /******************************** STATIC ***********************************/
273 /******************************************************************************/
275 #if 0 // avoid compiler warning for unused static function
277 fc_debug (struct MeshFlowControl *fc)
279 LOG (GNUNET_ERROR_TYPE_DEBUG, " IN: %u/%u\n",
280 fc->last_pid_recv, fc->last_ack_sent);
281 LOG (GNUNET_ERROR_TYPE_DEBUG, " OUT: %u/%u\n",
282 fc->last_pid_sent, fc->last_ack_recv);
283 LOG (GNUNET_ERROR_TYPE_DEBUG, " QUEUE: %u/%u\n",
284 fc->queue_n, fc->queue_max);
288 connection_debug (struct MeshConnection *c)
292 LOG (GNUNET_ERROR_TYPE_DEBUG, "*** DEBUG NULL CONNECTION ***\n");
295 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s:%X\n",
296 peer2s (c->t->peer), GMC_2s (c));
297 LOG (GNUNET_ERROR_TYPE_DEBUG, " state: %u, pending msgs: %u\n",
298 c->state, c->pending_messages);
299 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD FC\n");
300 fc_debug (&c->fwd_fc);
301 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK FC\n");
302 fc_debug (&c->bck_fc);
307 * Get string description for tunnel state.
309 * @param s Tunnel state.
311 * @return String representation.
314 GMC_state2s (enum MeshConnectionState s)
318 case MESH_CONNECTION_NEW:
319 return "MESH_CONNECTION_NEW";
320 case MESH_CONNECTION_SENT:
321 return "MESH_CONNECTION_SENT";
322 case MESH_CONNECTION_ACK:
323 return "MESH_CONNECTION_ACK";
324 case MESH_CONNECTION_READY:
325 return "MESH_CONNECTION_READY";
327 return "MESH_CONNECTION_STATE_ERROR";
333 * Initialize a Flow Control structure to the initial state.
335 * @param fc Flow Control structure to initialize.
338 fc_init (struct MeshFlowControl *fc)
341 fc->last_pid_sent = (uint32_t) -1; /* Next (expected) = 0 */
342 fc->last_pid_recv = (uint32_t) -1;
343 fc->last_ack_sent = (uint32_t) 0;
344 fc->last_ack_recv = (uint32_t) 0;
345 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
346 fc->poll_time = GNUNET_TIME_UNIT_SECONDS;
348 fc->queue_max = (max_msgs_queue / max_connections) + 1;
355 * @param cid Connection ID.
357 static struct MeshConnection *
358 connection_get (const struct GNUNET_HashCode *cid)
360 return GNUNET_CONTAINER_multihashmap_get (connections, cid);
365 connection_change_state (struct MeshConnection* c,
366 enum MeshConnectionState state)
368 LOG (GNUNET_ERROR_TYPE_DEBUG,
369 "Connection %s state was %s\n",
370 GMC_2s (c), GMC_state2s (c->state));
371 LOG (GNUNET_ERROR_TYPE_DEBUG,
372 "Connection %s state is now %s\n",
373 GMC_2s (c), GMC_state2s (state));
379 * Callback called when a queued ACK message is sent.
381 * @param cls Closure (FC).
382 * @param c Connection this message was on.
383 * @param type Type of message sent.
384 * @param fwd Was this a FWD going message?
385 * @param size Size of the message.
389 struct MeshConnection *c,
390 struct MeshConnectionQueue *q,
391 uint16_t type, int fwd, size_t size)
393 struct MeshFlowControl *fc = cls;
400 * Send an ACK on the connection, informing the predecessor about
401 * the available buffer space. Should not be called in case the peer
402 * is origin (no predecessor) in the @c fwd direction.
404 * Note that for fwd ack, the FWD mean forward *traffic* (root->dest),
405 * the ACK itself goes "back" (dest->root).
407 * @param c Connection on which to send the ACK.
408 * @param buffer How much space free to advertise?
409 * @param fwd Is this FWD ACK? (Going dest -> root)
410 * @param force Don't optimize out.
413 send_ack (struct MeshConnection *c, unsigned int buffer, int fwd, int force)
415 struct MeshFlowControl *next_fc;
416 struct MeshFlowControl *prev_fc;
417 struct GNUNET_MESH_ACK msg;
421 /* If origin, there is no connection to send ACKs. Wrong function! */
422 if (GMC_is_origin (c, fwd))
428 next_fc = fwd ? &c->fwd_fc : &c->bck_fc;
429 prev_fc = fwd ? &c->bck_fc : &c->fwd_fc;
431 LOG (GNUNET_ERROR_TYPE_DEBUG,
432 "connection send %s ack on %s\n",
433 fwd ? "FWD" : "BCK", GMC_2s (c));
435 /* Check if we need to transmit the ACK. */
436 delta = prev_fc->last_ack_sent - prev_fc->last_pid_recv;
437 if (3 < delta && buffer < delta && GNUNET_NO == force)
439 LOG (GNUNET_ERROR_TYPE_DEBUG, "Not sending ACK, buffer > 3\n");
440 LOG (GNUNET_ERROR_TYPE_DEBUG,
441 " last pid recv: %u, last ack sent: %u\n",
442 prev_fc->last_pid_recv, prev_fc->last_ack_sent);
446 /* Ok, ACK might be necessary, what PID to ACK? */
447 ack = prev_fc->last_pid_recv + buffer;
448 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK %u\n", ack);
449 LOG (GNUNET_ERROR_TYPE_DEBUG,
450 " last pid %u, last ack %u, qmax %u, q %u\n",
451 prev_fc->last_pid_recv, prev_fc->last_ack_sent,
452 next_fc->queue_max, next_fc->queue_n);
453 if (ack == prev_fc->last_ack_sent && GNUNET_NO == force)
455 LOG (GNUNET_ERROR_TYPE_DEBUG, "Not sending FWD ACK, not needed\n");
459 /* Check if message is already in queue */
460 if (NULL != prev_fc->ack_msg)
462 if (GMC_is_pid_bigger (ack, prev_fc->last_ack_sent))
464 LOG (GNUNET_ERROR_TYPE_DEBUG, " canceling old ACK\n");
465 GMC_cancel (prev_fc->ack_msg);
466 /* GMC_cancel triggers ack_sent(), which clears fc->ack_msg */
470 LOG (GNUNET_ERROR_TYPE_DEBUG, " same ACK already in queue\n");
475 prev_fc->last_ack_sent = ack;
477 /* Build ACK message and send on connection */
478 msg.header.size = htons (sizeof (msg));
479 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_ACK);
480 msg.ack = htonl (ack);
483 prev_fc->ack_msg = GMC_send_prebuilt_message (&msg.header, c, !fwd,
489 * Callback called when a queued message is sent.
491 * Calculates the average time and connection packet tracking.
493 * @param cls Closure (ConnectionQueue Handle).
494 * @param c Connection this message was on.
495 * @param type Type of message sent.
496 * @param fwd Was this a FWD going message?
497 * @param size Size of the message.
498 * @param wait Time spent waiting for core (only the time for THIS message)
501 message_sent (void *cls,
502 struct MeshConnection *c, uint16_t type,
503 int fwd, size_t size,
504 struct GNUNET_TIME_Relative wait)
506 struct MeshConnectionPerformance *p;
507 struct MeshFlowControl *fc;
508 struct MeshConnectionQueue *q = cls;
511 fc = fwd ? &c->fwd_fc : &c->bck_fc;
512 LOG (GNUNET_ERROR_TYPE_DEBUG,
515 GNUNET_MESH_DEBUG_M2S (type));
516 LOG (GNUNET_ERROR_TYPE_DEBUG, "! C_P- %p %u\n", c, c->pending_messages);
521 LOG (GNUNET_ERROR_TYPE_DEBUG, "! calling cont\n");
522 q->cont (q->cont_cls, c, q, type, fwd, size);
526 c->pending_messages--;
527 if (GNUNET_YES == c->destroy && 0 == c->pending_messages)
529 LOG (GNUNET_ERROR_TYPE_DEBUG, "! destroying connection!\n");
533 /* Send ACK if needed, after accounting for sent ID in fc->queue_n */
536 case GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED:
538 LOG (GNUNET_ERROR_TYPE_DEBUG, "! Q_N- %p %u\n", fc, fc->queue_n);
540 LOG (GNUNET_ERROR_TYPE_DEBUG,
541 "! accounting pid %u\n",
543 GMC_send_ack (c, fwd, GNUNET_NO);
546 case GNUNET_MESSAGE_TYPE_MESH_POLL:
550 case GNUNET_MESSAGE_TYPE_MESH_ACK:
557 LOG (GNUNET_ERROR_TYPE_DEBUG, "! message sent!\n");
560 return; /* Only endpoints are interested in timing. */
563 usecsperbyte = ((double) wait.rel_value_us) / size;
564 if (p->size == AVG_MSGS)
566 /* Array is full. Substract oldest value, add new one and store. */
567 p->avg -= (p->usecsperbyte[p->idx] / AVG_MSGS);
568 p->usecsperbyte[p->idx] = usecsperbyte;
569 p->avg += (p->usecsperbyte[p->idx] / AVG_MSGS);
573 /* Array not yet full. Add current value to avg and store. */
574 p->usecsperbyte[p->idx] = usecsperbyte;
576 p->avg += p->usecsperbyte[p->idx];
580 p->idx = (p->idx + 1) % AVG_MSGS;
585 * Get the previous hop in a connection
587 * @param c Connection.
589 * @return Previous peer in the connection.
591 static struct MeshPeer *
592 get_prev_hop (const struct MeshConnection *c)
596 LOG (GNUNET_ERROR_TYPE_DEBUG, "Get prev hop, own pos %u\n", c->own_pos);
597 if (0 == c->own_pos || c->path->length < 2)
598 id = c->path->peers[0];
600 id = c->path->peers[c->own_pos - 1];
602 return GMP_get_short (id);
607 * Get the next hop in a connection
609 * @param c Connection.
611 * @return Next peer in the connection.
613 static struct MeshPeer *
614 get_next_hop (const struct MeshConnection *c)
618 if ((c->path->length - 1) == c->own_pos || c->path->length < 2)
619 id = c->path->peers[c->path->length - 1];
621 id = c->path->peers[c->own_pos + 1];
623 return GMP_get_short (id);
628 * Get the hop in a connection.
630 * @param c Connection.
631 * @param fwd Next hop?
633 * @return Next peer in the connection.
635 static struct MeshPeer *
636 get_hop (struct MeshConnection *c, int fwd)
639 return get_next_hop (c);
640 return get_prev_hop (c);
645 * Is traffic coming from this sender 'FWD' traffic?
647 * @param c Connection to check.
648 * @param sender Peer identity of neighbor.
650 * @return #GNUNET_YES in case the sender is the 'prev' hop and therefore
651 * the traffic is 'FWD'.
652 * #GNUNET_NO for BCK.
653 * #GNUNET_SYSERR for errors.
656 is_fwd (const struct MeshConnection *c,
657 const struct GNUNET_PeerIdentity *sender)
661 id = GNUNET_PEER_search (sender);
662 if (GMP_get_short_id (get_prev_hop (c)) == id)
665 if (GMP_get_short_id (get_next_hop (c)) == id)
669 return GNUNET_SYSERR;
674 * Sends a CONNECTION ACK message in reponse to a received CONNECTION_CREATE
675 * or a first CONNECTION_ACK directed to us.
677 * @param connection Connection to confirm.
678 * @param fwd Should we send it FWD? (root->dest)
679 * (First (~SYNACK) goes BCK, second (~ACK) goes FWD)
682 send_connection_ack (struct MeshConnection *connection, int fwd)
684 struct MeshTunnel3 *t;
687 LOG (GNUNET_ERROR_TYPE_DEBUG, "Send connection %s ACK\n",
688 !fwd ? "FWD" : "BCK");
689 GMP_queue_add (get_hop (connection, fwd), NULL,
690 GNUNET_MESSAGE_TYPE_MESH_CONNECTION_ACK,
691 sizeof (struct GNUNET_MESH_ConnectionACK),
692 connection, fwd, &message_sent, NULL);
693 connection->pending_messages++;
694 if (MESH_TUNNEL3_NEW == GMT_get_state (t))
695 GMT_change_state (t, MESH_TUNNEL3_WAITING);
696 if (MESH_CONNECTION_READY != connection->state)
697 connection_change_state (connection, MESH_CONNECTION_SENT);
702 * Send a notification that a connection is broken.
704 * @param c Connection that is broken.
705 * @param id1 Peer that has disconnected.
706 * @param id2 Peer that has disconnected.
707 * @param fwd Direction towards which to send it.
710 send_broken (struct MeshConnection *c,
711 const struct GNUNET_PeerIdentity *id1,
712 const struct GNUNET_PeerIdentity *id2,
715 struct GNUNET_MESH_ConnectionBroken msg;
717 msg.header.size = htons (sizeof (struct GNUNET_MESH_ConnectionBroken));
718 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CONNECTION_BROKEN);
722 GMC_send_prebuilt_message (&msg.header, c, fwd, NULL, NULL);
728 * Send keepalive packets for a connection.
730 * @param c Connection to keep alive..
731 * @param fwd Is this a FWD keepalive? (owner -> dest).
734 connection_keepalive (struct MeshConnection *c, int fwd)
736 struct GNUNET_MESH_ConnectionKeepAlive *msg;
737 size_t size = sizeof (struct GNUNET_MESH_ConnectionKeepAlive);
741 type = fwd ? GNUNET_MESSAGE_TYPE_MESH_FWD_KEEPALIVE :
742 GNUNET_MESSAGE_TYPE_MESH_BCK_KEEPALIVE;
744 LOG (GNUNET_ERROR_TYPE_DEBUG,
745 "sending %s keepalive for connection %s]\n",
746 fwd ? "FWD" : "BCK", GMC_2s (c));
748 msg = (struct GNUNET_MESH_ConnectionKeepAlive *) cbuf;
749 msg->header.size = htons (size);
750 msg->header.type = htons (type);
753 GMC_send_prebuilt_message (&msg->header, c, fwd, NULL, NULL);
758 * Send CONNECTION_{CREATE/ACK} packets for a connection.
760 * @param c Connection for which to send the message.
761 * @param fwd If #GNUNET_YES, send CREATE, otherwise send ACK.
764 connection_recreate (struct MeshConnection *c, int fwd)
766 LOG (GNUNET_ERROR_TYPE_DEBUG, "sending connection recreate\n");
770 send_connection_ack (c, GNUNET_NO);
775 * Generic connection timer management.
776 * Depending on the role of the peer in the connection will send the
777 * appropriate message (build or keepalive)
779 * @param c Conncetion to maintain.
783 connection_maintain (struct MeshConnection *c, int fwd)
785 if (MESH_TUNNEL3_SEARCHING == GMT_get_state (c->t))
787 /* TODO DHT GET with RO_BART */
792 case MESH_CONNECTION_NEW:
794 case MESH_CONNECTION_SENT:
795 connection_recreate (c, fwd);
797 case MESH_CONNECTION_READY:
798 connection_keepalive (c, fwd);
807 connection_fwd_keepalive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
809 struct MeshConnection *c = cls;
810 struct GNUNET_TIME_Relative delay;
812 c->fwd_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
813 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
816 connection_maintain (c, GNUNET_YES);
817 delay = c->state == MESH_CONNECTION_READY ?
818 refresh_connection_time : create_connection_time;
819 c->fwd_maintenance_task = GNUNET_SCHEDULER_add_delayed (delay,
820 &connection_fwd_keepalive,
826 connection_bck_keepalive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
828 struct MeshConnection *c = cls;
829 struct GNUNET_TIME_Relative delay;
831 c->bck_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
832 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
835 connection_maintain (c, GNUNET_NO);
836 delay = c->state == MESH_CONNECTION_READY ?
837 refresh_connection_time : create_connection_time;
838 c->bck_maintenance_task = GNUNET_SCHEDULER_add_delayed (delay,
839 &connection_bck_keepalive,
845 * @brief Re-initiate traffic on this connection if necessary.
847 * Check if there is traffic queued towards this peer
848 * and the core transmit handle is NULL (traffic was stalled).
849 * If so, call core tmt rdy.
851 * @param c Connection on which initiate traffic.
852 * @param fwd Is this about fwd traffic?
855 connection_unlock_queue (struct MeshConnection *c, int fwd)
857 struct MeshPeer *peer;
859 LOG (GNUNET_ERROR_TYPE_DEBUG,
860 "connection_unlock_queue %s on %s\n",
861 fwd ? "FWD" : "BCK", GMC_2s (c));
863 if (GMC_is_terminal (c, fwd))
865 LOG (GNUNET_ERROR_TYPE_DEBUG, " is terminal!\n");
869 peer = get_hop (c, fwd);
870 GMP_queue_unlock (peer, c);
875 * Cancel all transmissions that belong to a certain connection.
877 * If the connection is scheduled for destruction and no more messages are left,
878 * the connection will be destroyed by the continuation call.
880 * @param c Connection which to cancel. Might be destroyed during this call.
881 * @param fwd Cancel fwd traffic?
884 connection_cancel_queues (struct MeshConnection *c, int fwd)
886 struct MeshFlowControl *fc;
887 struct MeshPeer *peer;
895 fc = fwd ? &c->fwd_fc : &c->bck_fc;
896 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task)
898 GNUNET_SCHEDULER_cancel (fc->poll_task);
899 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
901 peer = get_hop (c, fwd);
902 GMP_queue_cancel (peer, c);
907 * Function called if a connection has been stalled for a while,
908 * possibly due to a missed ACK. Poll the neighbor about its ACK status.
910 * @param cls Closure (poll ctx).
911 * @param tc TaskContext.
914 connection_poll (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
918 * Callback called when a queued POLL message is sent.
920 * @param cls Closure (FC).
921 * @param c Connection this message was on.
922 * @param type Type of message sent.
923 * @param fwd Was this a FWD going message?
924 * @param size Size of the message.
927 poll_sent (void *cls,
928 struct MeshConnection *c,
929 struct MeshConnectionQueue *q,
930 uint16_t type, int fwd, size_t size)
932 struct MeshFlowControl *fc = cls;
934 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL sent, scheduling new one!\n");
936 fc->poll_time = GNUNET_TIME_STD_BACKOFF (fc->poll_time);
937 fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time,
938 &connection_poll, fc);
942 * Function called if a connection has been stalled for a while,
943 * possibly due to a missed ACK. Poll the neighbor about its ACK status.
945 * @param cls Closure (poll ctx).
946 * @param tc TaskContext.
949 connection_poll (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
951 struct MeshFlowControl *fc = cls;
952 struct GNUNET_MESH_Poll msg;
953 struct MeshConnection *c;
955 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
956 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
962 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** Polling!\n");
963 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** connection [%s]\n", GMC_2s (c));
964 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** %s\n",
965 fc == &c->fwd_fc ? "FWD" : "BCK");
967 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_POLL);
968 msg.header.size = htons (sizeof (msg));
969 msg.pid = htonl (fc->last_pid_sent);
970 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** last pid sent: %u!\n", fc->last_pid_sent);
971 fc->poll_msg = GMC_send_prebuilt_message (&msg.header, c, fc == &c->fwd_fc,
977 * Timeout function due to lack of keepalive/traffic from the owner.
978 * Destroys connection if called.
980 * @param cls Closure (connection to destroy).
981 * @param tc TaskContext.
984 connection_fwd_timeout (void *cls,
985 const struct GNUNET_SCHEDULER_TaskContext *tc)
987 struct MeshConnection *c = cls;
989 c->fwd_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
990 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
992 LOG (GNUNET_ERROR_TYPE_DEBUG,
993 "Connection %s[%X] FWD timed out. Destroying.\n",
997 if (GMC_is_origin (c, GNUNET_YES)) /* If local, leave. */
1005 * Timeout function due to lack of keepalive/traffic from the destination.
1006 * Destroys connection if called.
1008 * @param cls Closure (connection to destroy).
1009 * @param tc TaskContext
1012 connection_bck_timeout (void *cls,
1013 const struct GNUNET_SCHEDULER_TaskContext *tc)
1015 struct MeshConnection *c = cls;
1017 c->bck_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
1018 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1021 LOG (GNUNET_ERROR_TYPE_DEBUG,
1022 "Connection %s[%X] FWD timed out. Destroying.\n",
1023 GMT_2s (c->t), c->id);
1025 if (GMC_is_origin (c, GNUNET_NO)) /* If local, leave. */
1033 * Resets the connection timeout task, some other message has done the
1035 * - For the first peer on the direction this means to send
1036 * a keepalive or a path confirmation message (either create or ACK).
1037 * - For all other peers, this means to destroy the connection,
1038 * due to lack of activity.
1039 * Starts the tiemout if no timeout was running (connection just created).
1041 * @param c Connection whose timeout to reset.
1042 * @param fwd Is this forward?
1044 * TODO use heap to improve efficiency of scheduler.
1047 connection_reset_timeout (struct MeshConnection *c, int fwd)
1049 GNUNET_SCHEDULER_TaskIdentifier *ti;
1050 GNUNET_SCHEDULER_Task f;
1052 ti = fwd ? &c->fwd_maintenance_task : &c->bck_maintenance_task;
1054 if (GNUNET_SCHEDULER_NO_TASK != *ti)
1055 GNUNET_SCHEDULER_cancel (*ti);
1057 if (GMC_is_origin (c, fwd)) /* Startpoint */
1059 f = fwd ? &connection_fwd_keepalive : &connection_bck_keepalive;
1060 *ti = GNUNET_SCHEDULER_add_delayed (refresh_connection_time, f, c);
1062 else /* Relay, endpoint. */
1064 struct GNUNET_TIME_Relative delay;
1066 delay = GNUNET_TIME_relative_multiply (refresh_connection_time, 4);
1067 f = fwd ? &connection_fwd_timeout : &connection_bck_timeout;
1068 *ti = GNUNET_SCHEDULER_add_delayed (delay, f, c);
1074 * Add the connection to the list of both neighbors.
1076 * @param c Connection.
1079 register_neighbors (struct MeshConnection *c)
1081 struct MeshPeer *peer;
1083 peer = get_next_hop (c);
1084 if (GNUNET_NO == GMP_is_neighbor (peer))
1089 GMP_add_connection (peer, c);
1090 peer = get_prev_hop (c);
1091 if (GNUNET_NO == GMP_is_neighbor (peer))
1096 GMP_add_connection (peer, c);
1101 * Remove the connection from the list of both neighbors.
1103 * @param c Connection.
1106 unregister_neighbors (struct MeshConnection *c)
1108 struct MeshPeer *peer;
1110 peer = get_next_hop (c);
1111 GMP_remove_connection (peer, c);
1113 peer = get_prev_hop (c);
1114 GMP_remove_connection (peer, c);
1120 * Bind the connection to the peer and the tunnel to that peer.
1122 * If the peer has no tunnel, create one. Update tunnel and connection
1123 * data structres to reflect new status.
1125 * @param c Connection.
1129 add_to_peer (struct MeshConnection *c, struct MeshPeer *peer)
1131 GMP_add_tunnel (peer);
1132 c->t = GMP_get_tunnel (peer);
1133 GMT_add_connection (c->t, c);
1136 /******************************************************************************/
1137 /******************************** API ***********************************/
1138 /******************************************************************************/
1141 * Core handler for connection creation.
1143 * @param cls Closure (unused).
1144 * @param peer Sender (neighbor).
1145 * @param message Message.
1147 * @return GNUNET_OK to keep the connection open,
1148 * GNUNET_SYSERR to close it (signal serious error)
1151 GMC_handle_create (void *cls, const struct GNUNET_PeerIdentity *peer,
1152 const struct GNUNET_MessageHeader *message)
1154 struct GNUNET_MESH_ConnectionCreate *msg;
1155 struct GNUNET_PeerIdentity *id;
1156 struct GNUNET_HashCode *cid;
1157 struct MeshPeerPath *path;
1158 struct MeshPeer *dest_peer;
1159 struct MeshPeer *orig_peer;
1160 struct MeshConnection *c;
1161 unsigned int own_pos;
1165 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1166 LOG (GNUNET_ERROR_TYPE_DEBUG, "Received a connection create msg\n");
1169 size = ntohs (message->size);
1170 if (size < sizeof (struct GNUNET_MESH_ConnectionCreate))
1172 GNUNET_break_op (0);
1176 /* Calculate hops */
1177 size -= sizeof (struct GNUNET_MESH_ConnectionCreate);
1178 if (size % sizeof (struct GNUNET_PeerIdentity))
1180 GNUNET_break_op (0);
1183 size /= sizeof (struct GNUNET_PeerIdentity);
1186 GNUNET_break_op (0);
1189 LOG (GNUNET_ERROR_TYPE_DEBUG, " path has %u hops.\n", size);
1191 /* Get parameters */
1192 msg = (struct GNUNET_MESH_ConnectionCreate *) message;
1194 id = (struct GNUNET_PeerIdentity *) &msg[1];
1195 LOG (GNUNET_ERROR_TYPE_DEBUG,
1196 " connection %s (%s).\n",
1197 GNUNET_h2s (cid), GNUNET_i2s (id));
1199 /* Create connection */
1200 c = connection_get (cid);
1204 LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating path...\n");
1205 path = path_new (size);
1207 for (i = 0; i < size; i++)
1209 LOG (GNUNET_ERROR_TYPE_DEBUG, " ... adding %s\n",
1210 GNUNET_i2s (&id[i]));
1211 path->peers[i] = GNUNET_PEER_intern (&id[i]);
1212 if (path->peers[i] == myid)
1215 if (own_pos == 0 && path->peers[own_pos] != myid)
1217 /* create path: self not found in path through self */
1218 GNUNET_break_op (0);
1219 path_destroy (path);
1222 LOG (GNUNET_ERROR_TYPE_DEBUG, " Own position: %u\n", own_pos);
1223 GMP_add_path_to_all (path, GNUNET_NO);
1224 LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating connection\n");
1225 c = GMC_new (cid, NULL, path_duplicate (path), own_pos);
1228 connection_reset_timeout (c, GNUNET_YES);
1234 if (MESH_CONNECTION_NEW == c->state)
1235 connection_change_state (c, MESH_CONNECTION_SENT);
1237 /* Remember peers */
1238 dest_peer = GMP_get (&id[size - 1]);
1239 orig_peer = GMP_get (&id[0]);
1241 /* Is it a connection to us? */
1242 if (c->own_pos == size - 1)
1244 LOG (GNUNET_ERROR_TYPE_DEBUG, " It's for us!\n");
1245 GMP_add_path_to_origin (orig_peer, path, GNUNET_YES);
1247 add_to_peer (c, orig_peer);
1248 if (MESH_TUNNEL3_NEW == GMT_get_state (c->t))
1249 GMT_change_state (c->t, MESH_TUNNEL3_WAITING);
1251 send_connection_ack (c, GNUNET_NO);
1252 if (MESH_CONNECTION_SENT == c->state)
1253 connection_change_state (c, MESH_CONNECTION_ACK);
1255 /* Keep tunnel alive in direction dest->owner*/
1256 c->bck_maintenance_task =
1257 GNUNET_SCHEDULER_add_delayed (create_connection_time,
1258 &connection_bck_keepalive, c);
1262 /* It's for somebody else! Retransmit. */
1263 LOG (GNUNET_ERROR_TYPE_DEBUG, " Retransmitting.\n");
1264 GMP_add_path (dest_peer, path_duplicate (path), GNUNET_NO);
1265 GMP_add_path_to_origin (orig_peer, path, GNUNET_NO);
1266 GMC_send_prebuilt_message (message, c, GNUNET_YES, NULL, NULL);
1273 * Core handler for path confirmations.
1275 * @param cls closure
1276 * @param message message
1277 * @param peer peer identity this notification is about
1279 * @return GNUNET_OK to keep the connection open,
1280 * GNUNET_SYSERR to close it (signal serious error)
1283 GMC_handle_confirm (void *cls, const struct GNUNET_PeerIdentity *peer,
1284 const struct GNUNET_MessageHeader *message)
1286 struct GNUNET_MESH_ConnectionACK *msg;
1287 struct MeshConnection *c;
1288 struct MeshPeerPath *p;
1289 struct MeshPeer *pi;
1290 enum MeshConnectionState oldstate;
1293 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1294 LOG (GNUNET_ERROR_TYPE_DEBUG, "Received a connection ACK msg\n");
1295 msg = (struct GNUNET_MESH_ConnectionACK *) message;
1296 LOG (GNUNET_ERROR_TYPE_DEBUG, " on connection %s\n",
1297 GNUNET_h2s (&msg->cid));
1298 c = connection_get (&msg->cid);
1301 GNUNET_STATISTICS_update (stats, "# control on unknown connection",
1303 LOG (GNUNET_ERROR_TYPE_DEBUG, " don't know the connection!\n");
1307 oldstate = c->state;
1308 LOG (GNUNET_ERROR_TYPE_DEBUG, " via peer %s\n", GNUNET_i2s (peer));
1309 pi = GMP_get (peer);
1310 if (get_next_hop (c) == pi)
1312 LOG (GNUNET_ERROR_TYPE_DEBUG, " SYNACK\n");
1314 if (MESH_CONNECTION_SENT == oldstate)
1315 connection_change_state (c, MESH_CONNECTION_ACK);
1317 else if (get_prev_hop (c) == pi)
1319 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK\n");
1321 connection_change_state (c, MESH_CONNECTION_READY);
1325 GNUNET_break_op (0);
1329 connection_reset_timeout (c, fwd);
1331 /* Add path to peers? */
1335 GMP_add_path_to_all (p, GNUNET_YES);
1342 /* Message for us as creator? */
1343 if (GMC_is_origin (c, GNUNET_YES))
1345 if (GNUNET_NO != fwd)
1347 GNUNET_break_op (0);
1350 LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection (SYN)ACK for us!\n");
1352 /* If just created, cancel the short timeout and start a long one */
1353 if (MESH_CONNECTION_SENT == oldstate)
1354 connection_reset_timeout (c, GNUNET_YES);
1356 /* Change tunnel state */
1357 if (MESH_TUNNEL3_WAITING == GMT_get_state (c->t))
1358 GMT_change_state (c->t, MESH_TUNNEL3_READY);
1360 /* Send ACK (~TCP ACK)*/
1361 send_connection_ack (c, GNUNET_YES);
1364 /* Message for us as destination? */
1365 if (GMC_is_terminal (c, GNUNET_YES))
1367 if (GNUNET_YES != fwd)
1369 GNUNET_break_op (0);
1372 LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection ACK for us!\n");
1374 /* If just created, cancel the short timeout and start a long one */
1375 if (MESH_CONNECTION_ACK == oldstate)
1376 connection_reset_timeout (c, GNUNET_NO);
1378 /* Change tunnel state */
1379 if (MESH_TUNNEL3_WAITING == GMT_get_state (c->t))
1380 GMT_change_state (c->t, MESH_TUNNEL3_READY);
1385 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
1386 GMC_send_prebuilt_message (message, c, fwd, NULL, NULL);
1392 * Core handler for notifications of broken paths
1394 * @param cls Closure (unused).
1395 * @param id Peer identity of sending neighbor.
1396 * @param message Message.
1398 * @return GNUNET_OK to keep the connection open,
1399 * GNUNET_SYSERR to close it (signal serious error)
1402 GMC_handle_broken (void* cls,
1403 const struct GNUNET_PeerIdentity* id,
1404 const struct GNUNET_MessageHeader* message)
1406 struct GNUNET_MESH_ConnectionBroken *msg;
1407 struct MeshConnection *c;
1410 LOG (GNUNET_ERROR_TYPE_DEBUG,
1411 "Received a CONNECTION BROKEN msg from %s\n", GNUNET_i2s (id));
1412 msg = (struct GNUNET_MESH_ConnectionBroken *) message;
1413 LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n",
1414 GNUNET_i2s (&msg->peer1));
1415 LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n",
1416 GNUNET_i2s (&msg->peer2));
1417 c = connection_get (&msg->cid);
1420 GNUNET_break_op (0);
1424 fwd = is_fwd (c, id);
1425 connection_cancel_queues (c, !fwd);
1426 if (GMC_is_terminal (c, fwd))
1428 if (0 < c->pending_messages)
1429 c->destroy = GNUNET_YES;
1435 GMC_send_prebuilt_message (message, c, fwd, NULL, NULL);
1436 c->destroy = GNUNET_YES;
1445 * Core handler for tunnel destruction
1447 * @param cls Closure (unused).
1448 * @param peer Peer identity of sending neighbor.
1449 * @param message Message.
1451 * @return GNUNET_OK to keep the connection open,
1452 * GNUNET_SYSERR to close it (signal serious error)
1455 GMC_handle_destroy (void *cls, const struct GNUNET_PeerIdentity *peer,
1456 const struct GNUNET_MessageHeader *message)
1458 struct GNUNET_MESH_ConnectionDestroy *msg;
1459 struct MeshConnection *c;
1462 msg = (struct GNUNET_MESH_ConnectionDestroy *) message;
1463 LOG (GNUNET_ERROR_TYPE_DEBUG,
1464 "Got a CONNECTION DESTROY message from %s\n",
1466 LOG (GNUNET_ERROR_TYPE_DEBUG,
1467 " for connection %s\n",
1468 GNUNET_h2s (&msg->cid));
1469 c = connection_get (&msg->cid);
1472 /* Probably already got the message from another path,
1473 * destroyed the tunnel and retransmitted to children.
1476 GNUNET_STATISTICS_update (stats, "# control on unknown tunnel",
1480 fwd = is_fwd (c, peer);
1481 if (GNUNET_SYSERR == fwd)
1483 GNUNET_break_op (0);
1486 GMC_send_prebuilt_message (message, c, fwd, NULL, NULL);
1487 c->destroy = GNUNET_YES;
1493 * Generic handler for mesh network encrypted traffic.
1495 * @param peer Peer identity this notification is about.
1496 * @param msg Encrypted message.
1498 * @return GNUNET_OK to keep the connection open,
1499 * GNUNET_SYSERR to close it (signal serious error)
1502 handle_mesh_encrypted (const struct GNUNET_PeerIdentity *peer,
1503 const struct GNUNET_MESH_Encrypted *msg)
1505 struct MeshConnection *c;
1506 struct MeshPeer *neighbor;
1507 struct MeshFlowControl *fc;
1508 GNUNET_PEER_Id peer_id;
1516 size = ntohs (msg->header.size);
1518 sizeof (struct GNUNET_MESH_Encrypted) +
1519 sizeof (struct GNUNET_MessageHeader))
1521 GNUNET_break_op (0);
1524 type = ntohs (msg->header.type);
1525 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1526 LOG (GNUNET_ERROR_TYPE_DEBUG, "got a %s message (#%u) from %s\n",
1527 GNUNET_MESH_DEBUG_M2S (type), ntohl (msg->pid), GNUNET_i2s (peer));
1529 /* Check connection */
1530 c = connection_get (&msg->cid);
1533 GNUNET_STATISTICS_update (stats, "# unknown connection", 1, GNUNET_NO);
1534 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING connection unknown\n");
1538 /* Check if origin is as expected */
1539 neighbor = get_prev_hop (c);
1540 peer_id = GNUNET_PEER_search (peer);
1541 if (peer_id == GMP_get_short_id (neighbor))
1547 neighbor = get_next_hop (c);
1548 if (peer_id == GMP_get_short_id (neighbor))
1554 /* Unexpected peer sending traffic on a connection. */
1555 GNUNET_break_op (0);
1561 fc = fwd ? &c->bck_fc : &c->fwd_fc;
1562 pid = ntohl (msg->pid);
1563 if (GMC_is_pid_bigger (pid, fc->last_ack_sent))
1565 GNUNET_STATISTICS_update (stats, "# unsolicited message", 1, GNUNET_NO);
1566 LOG (GNUNET_ERROR_TYPE_DEBUG,
1567 "WARNING Received PID %u, (prev %u), ACK %u\n",
1568 pid, fc->last_pid_recv, fc->last_ack_sent);
1571 if (GNUNET_NO == GMC_is_pid_bigger (pid, fc->last_pid_recv))
1573 GNUNET_STATISTICS_update (stats, "# duplicate PID", 1, GNUNET_NO);
1574 LOG (GNUNET_ERROR_TYPE_DEBUG,
1575 " Pid %u not expected (%u+), dropping!\n",
1576 pid, fc->last_pid_recv + 1);
1579 if (MESH_CONNECTION_SENT == c->state || MESH_CONNECTION_ACK == c->state)
1580 connection_change_state (c, MESH_CONNECTION_READY);
1581 connection_reset_timeout (c, fwd);
1582 fc->last_pid_recv = pid;
1584 /* Is this message for us? */
1585 if (GMC_is_terminal (c, fwd))
1587 /* TODO signature verification */
1588 LOG (GNUNET_ERROR_TYPE_DEBUG, " message for us!\n");
1589 GNUNET_STATISTICS_update (stats, "# messages received", 1, GNUNET_NO);
1596 fc->last_pid_recv = pid;
1597 GMT_handle_encrypted (c->t, msg);
1598 GMC_send_ack (c, fwd, GNUNET_NO);
1602 /* Message not for us: forward to next hop */
1603 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
1604 ttl = ntohl (msg->ttl);
1605 LOG (GNUNET_ERROR_TYPE_DEBUG, " ttl: %u\n", ttl);
1608 GNUNET_STATISTICS_update (stats, "# TTL drops", 1, GNUNET_NO);
1609 LOG (GNUNET_ERROR_TYPE_WARNING, " TTL is 0, DROPPING!\n");
1610 GMC_send_ack (c, fwd, GNUNET_NO);
1614 GNUNET_STATISTICS_update (stats, "# messages forwarded", 1, GNUNET_NO);
1615 GMC_send_prebuilt_message (&msg->header, c, fwd, NULL, NULL);
1621 * Generic handler for mesh network encrypted traffic.
1623 * @param peer Peer identity this notification is about.
1624 * @param msg Encrypted message.
1626 * @return GNUNET_OK to keep the connection open,
1627 * GNUNET_SYSERR to close it (signal serious error)
1630 handle_mesh_kx (const struct GNUNET_PeerIdentity *peer,
1631 const struct GNUNET_MESH_KX *msg)
1633 struct MeshConnection *c;
1634 struct MeshPeer *neighbor;
1635 GNUNET_PEER_Id peer_id;
1641 size = ntohs (msg->header.size);
1643 sizeof (struct GNUNET_MESH_Encrypted) +
1644 sizeof (struct GNUNET_MessageHeader))
1646 GNUNET_break_op (0);
1649 type = ntohs (msg->header.type);
1650 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1651 LOG (GNUNET_ERROR_TYPE_DEBUG, "got a %s message from %s\n",
1652 GNUNET_MESH_DEBUG_M2S (type), GNUNET_i2s (peer));
1654 /* Check connection */
1655 c = connection_get (&msg->cid);
1658 GNUNET_STATISTICS_update (stats, "# unknown connection", 1, GNUNET_NO);
1659 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING connection unknown\n");
1663 /* Check if origin is as expected */
1664 neighbor = get_prev_hop (c);
1665 peer_id = GNUNET_PEER_search (peer);
1666 if (peer_id == GMP_get_short_id (neighbor))
1672 neighbor = get_next_hop (c);
1673 if (peer_id == GMP_get_short_id (neighbor))
1679 /* Unexpected peer sending traffic on a connection. */
1680 GNUNET_break_op (0);
1685 /* Count as connection confirmation. */
1686 if (MESH_CONNECTION_SENT == c->state || MESH_CONNECTION_ACK == c->state)
1687 connection_change_state (c, MESH_CONNECTION_READY);
1688 connection_reset_timeout (c, fwd);
1691 if (MESH_TUNNEL3_WAITING == GMT_get_state (c->t))
1692 GMT_change_state (c->t, MESH_TUNNEL3_READY);
1695 /* Is this message for us? */
1696 if (GMC_is_terminal (c, fwd))
1698 LOG (GNUNET_ERROR_TYPE_DEBUG, " message for us!\n");
1699 GNUNET_STATISTICS_update (stats, "# messages received", 1, GNUNET_NO);
1705 GMT_handle_kx (c->t, &msg[1].header);
1709 /* Message not for us: forward to next hop */
1710 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
1711 GNUNET_STATISTICS_update (stats, "# messages forwarded", 1, GNUNET_NO);
1712 GMC_send_prebuilt_message (&msg->header, c, fwd, NULL, NULL);
1719 * Core handler for encrypted mesh network traffic (channel mgmt, data).
1721 * @param cls Closure (unused).
1722 * @param message Message received.
1723 * @param peer Peer who sent the message.
1725 * @return GNUNET_OK to keep the connection open,
1726 * GNUNET_SYSERR to close it (signal serious error)
1729 GMC_handle_encrypted (void *cls, const struct GNUNET_PeerIdentity *peer,
1730 const struct GNUNET_MessageHeader *message)
1732 return handle_mesh_encrypted (peer,
1733 (struct GNUNET_MESH_Encrypted *)message);
1738 * Core handler for key exchange traffic (ephemeral key, ping, pong).
1740 * @param cls Closure (unused).
1741 * @param message Message received.
1742 * @param peer Peer who sent the message.
1744 * @return GNUNET_OK to keep the connection open,
1745 * GNUNET_SYSERR to close it (signal serious error)
1748 GMC_handle_kx (void *cls, const struct GNUNET_PeerIdentity *peer,
1749 const struct GNUNET_MessageHeader *message)
1751 return handle_mesh_kx (peer,
1752 (struct GNUNET_MESH_KX *) message);
1757 * Core handler for mesh network traffic point-to-point acks.
1759 * @param cls closure
1760 * @param message message
1761 * @param peer peer identity this notification is about
1763 * @return GNUNET_OK to keep the connection open,
1764 * GNUNET_SYSERR to close it (signal serious error)
1767 GMC_handle_ack (void *cls, const struct GNUNET_PeerIdentity *peer,
1768 const struct GNUNET_MessageHeader *message)
1770 struct GNUNET_MESH_ACK *msg;
1771 struct MeshConnection *c;
1772 struct MeshFlowControl *fc;
1777 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1778 LOG (GNUNET_ERROR_TYPE_DEBUG, "Got an ACK packet from %s!\n",
1780 msg = (struct GNUNET_MESH_ACK *) message;
1782 c = connection_get (&msg->cid);
1786 GNUNET_STATISTICS_update (stats, "# ack on unknown connection", 1,
1791 /* Is this a forward or backward ACK? */
1792 id = GNUNET_PEER_search (peer);
1793 if (GMP_get_short_id (get_next_hop (c)) == id)
1795 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD ACK\n");
1799 else if (GMP_get_short_id (get_prev_hop (c)) == id)
1801 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK ACK\n");
1807 GNUNET_break_op (0);
1811 ack = ntohl (msg->ack);
1812 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK %u (was %u)\n",
1813 ack, fc->last_ack_recv);
1814 if (GMC_is_pid_bigger (ack, fc->last_ack_recv))
1815 fc->last_ack_recv = ack;
1817 /* Cancel polling if the ACK is big enough. */
1818 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task &&
1819 GMC_is_pid_bigger (fc->last_ack_recv, fc->last_pid_sent))
1821 LOG (GNUNET_ERROR_TYPE_DEBUG, " Cancel poll\n");
1822 GNUNET_SCHEDULER_cancel (fc->poll_task);
1823 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
1824 fc->poll_time = GNUNET_TIME_UNIT_SECONDS;
1827 connection_unlock_queue (c, fwd);
1834 * Core handler for mesh network traffic point-to-point ack polls.
1836 * @param cls closure
1837 * @param message message
1838 * @param peer peer identity this notification is about
1840 * @return GNUNET_OK to keep the connection open,
1841 * GNUNET_SYSERR to close it (signal serious error)
1844 GMC_handle_poll (void *cls, const struct GNUNET_PeerIdentity *peer,
1845 const struct GNUNET_MessageHeader *message)
1847 struct GNUNET_MESH_Poll *msg;
1848 struct MeshConnection *c;
1849 struct MeshFlowControl *fc;
1854 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1855 LOG (GNUNET_ERROR_TYPE_DEBUG,
1856 "Got a POLL packet from %s!\n",
1859 msg = (struct GNUNET_MESH_Poll *) message;
1861 c = connection_get (&msg->cid);
1865 GNUNET_STATISTICS_update (stats, "# poll on unknown connection", 1,
1867 GNUNET_break_op (0);
1871 /* Is this a forward or backward ACK?
1872 * Note: a poll should never be needed in a loopback case,
1873 * since there is no possiblility of packet loss there, so
1874 * this way of discerining FWD/BCK should not be a problem.
1876 id = GNUNET_PEER_search (peer);
1877 if (GMP_get_short_id (get_next_hop (c)) == id)
1879 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD FC\n");
1882 else if (GMP_get_short_id (get_prev_hop (c)) == id)
1884 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK FC\n");
1889 GNUNET_break_op (0);
1893 pid = ntohl (msg->pid);
1894 LOG (GNUNET_ERROR_TYPE_DEBUG, " PID %u, OLD %u\n", pid, fc->last_pid_recv);
1895 fc->last_pid_recv = pid;
1896 fwd = fc == &c->bck_fc;
1897 GMC_send_ack (c, fwd, GNUNET_YES);
1904 * Core handler for mesh keepalives.
1906 * @param cls closure
1907 * @param message message
1908 * @param peer peer identity this notification is about
1909 * @return GNUNET_OK to keep the connection open,
1910 * GNUNET_SYSERR to close it (signal serious error)
1912 * TODO: Check who we got this from, to validate route.
1915 GMC_handle_keepalive (void *cls, const struct GNUNET_PeerIdentity *peer,
1916 const struct GNUNET_MessageHeader *message)
1918 struct GNUNET_MESH_ConnectionKeepAlive *msg;
1919 struct MeshConnection *c;
1920 struct MeshPeer *neighbor;
1923 msg = (struct GNUNET_MESH_ConnectionKeepAlive *) message;
1924 LOG (GNUNET_ERROR_TYPE_DEBUG, "got a keepalive packet from %s\n",
1927 c = connection_get (&msg->cid);
1930 GNUNET_STATISTICS_update (stats, "# keepalive on unknown connection", 1,
1935 fwd = GNUNET_MESSAGE_TYPE_MESH_FWD_KEEPALIVE == ntohs (message->type) ?
1936 GNUNET_YES : GNUNET_NO;
1938 /* Check if origin is as expected */
1939 neighbor = get_hop (c, fwd);
1940 if (GNUNET_PEER_search (peer) != GMP_get_short_id (neighbor))
1942 GNUNET_break_op (0);
1946 connection_change_state (c, MESH_CONNECTION_READY);
1947 connection_reset_timeout (c, fwd);
1949 if (GMC_is_terminal (c, fwd))
1952 GNUNET_STATISTICS_update (stats, "# keepalives forwarded", 1, GNUNET_NO);
1953 GMC_send_prebuilt_message (message, c, fwd, NULL, NULL);
1960 * Send an ACK on the appropriate connection/channel, depending on
1961 * the direction and the position of the peer.
1963 * @param c Which connection to send the hop-by-hop ACK.
1964 * @param fwd Is this a fwd ACK? (will go dest->root).
1965 * @param force Send the ACK even if suboptimal (e.g. requested by POLL).
1968 GMC_send_ack (struct MeshConnection *c, int fwd, int force)
1970 unsigned int buffer;
1972 LOG (GNUNET_ERROR_TYPE_DEBUG,
1973 "GMC send %s ACK on %s\n",
1974 fwd ? "FWD" : "BCK", GMC_2s (c));
1982 /* Get available buffer space */
1983 if (GMC_is_terminal (c, fwd))
1985 LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from all channels\n");
1986 buffer = GMT_get_channels_buffer (c->t);
1990 LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from one connection\n");
1991 buffer = GMC_get_buffer (c, fwd);
1993 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer available: %u\n", buffer);
1994 if (0 == buffer && GNUNET_NO == force)
1997 /* Send available buffer space */
1998 if (GMC_is_origin (c, fwd))
2000 GNUNET_assert (NULL != c->t);
2001 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channels...\n");
2002 GMT_unchoke_channels (c->t);
2006 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on connection\n");
2007 send_ack (c, buffer, fwd, force);
2013 * Initialize the connections subsystem
2015 * @param c Configuration handle.
2018 GMC_init (const struct GNUNET_CONFIGURATION_Handle *c)
2020 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
2022 GNUNET_CONFIGURATION_get_value_number (c, "MESH", "MAX_MSGS_QUEUE",
2025 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
2026 "MESH", "MAX_MSGS_QUEUE", "MISSING");
2027 GNUNET_SCHEDULER_shutdown ();
2032 GNUNET_CONFIGURATION_get_value_number (c, "MESH", "MAX_CONNECTIONS",
2035 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
2036 "MESH", "MAX_CONNECTIONS", "MISSING");
2037 GNUNET_SCHEDULER_shutdown ();
2042 GNUNET_CONFIGURATION_get_value_time (c, "MESH", "REFRESH_CONNECTION_TIME",
2043 &refresh_connection_time))
2045 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
2046 "MESH", "REFRESH_CONNECTION_TIME", "MISSING");
2047 GNUNET_SCHEDULER_shutdown ();
2050 create_connection_time = GNUNET_TIME_UNIT_SECONDS;
2051 connections = GNUNET_CONTAINER_multihashmap_create (1024, GNUNET_YES);
2055 * Shut down the connections subsystem.
2060 GNUNET_CONTAINER_multihashmap_destroy (connections);
2064 struct MeshConnection *
2065 GMC_new (const struct GNUNET_HashCode *cid,
2066 struct MeshTunnel3 *t,
2067 struct MeshPeerPath *p,
2068 unsigned int own_pos)
2070 struct MeshConnection *c;
2072 c = GNUNET_new (struct MeshConnection);
2074 GNUNET_CONTAINER_multihashmap_put (connections, &c->id, c,
2075 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST);
2076 fc_init (&c->fwd_fc);
2077 fc_init (&c->bck_fc);
2082 if (own_pos > p->length - 1)
2088 c->own_pos = own_pos;
2093 c->fwd_maintenance_task =
2094 GNUNET_SCHEDULER_add_delayed (create_connection_time,
2095 &connection_fwd_keepalive, c);
2097 register_neighbors (c);
2103 GMC_destroy (struct MeshConnection *c)
2108 if (2 == c->destroy) /* cancel queues -> GMP_queue_cancel -> q_destroy -> */
2109 return; /* -> message_sent -> GMC_destroy. Don't loop. */
2112 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying connection %s\n", GMC_2s (c));
2114 /* Cancel all traffic */
2115 connection_cancel_queues (c, GNUNET_YES);
2116 connection_cancel_queues (c, GNUNET_NO);
2118 /* Cancel maintainance task (keepalive/timeout) */
2119 if (GNUNET_SCHEDULER_NO_TASK != c->fwd_maintenance_task)
2120 GNUNET_SCHEDULER_cancel (c->fwd_maintenance_task);
2121 if (GNUNET_SCHEDULER_NO_TASK != c->bck_maintenance_task)
2122 GNUNET_SCHEDULER_cancel (c->bck_maintenance_task);
2124 /* Unregister from neighbors */
2125 unregister_neighbors (c);
2128 GNUNET_STATISTICS_update (stats, "# connections", -1, GNUNET_NO);
2130 GMT_remove_connection (c->t, c);
2132 if (GNUNET_NO == GMC_is_origin (c, GNUNET_YES))
2133 path_destroy (c->path);
2135 GNUNET_CONTAINER_multihashmap_remove (connections, &c->id, c);
2141 * Get the connection ID.
2143 * @param c Connection to get the ID from.
2145 * @return ID of the connection.
2147 const struct GNUNET_HashCode *
2148 GMC_get_id (const struct MeshConnection *c)
2155 * Get the connection path.
2157 * @param c Connection to get the path from.
2159 * @return path used by the connection.
2161 const struct MeshPeerPath *
2162 GMC_get_path (const struct MeshConnection *c)
2169 * Get the connection state.
2171 * @param c Connection to get the state from.
2173 * @return state of the connection.
2175 enum MeshConnectionState
2176 GMC_get_state (const struct MeshConnection *c)
2182 * Get the connection tunnel.
2184 * @param c Connection to get the tunnel from.
2186 * @return tunnel of the connection.
2188 struct MeshTunnel3 *
2189 GMC_get_tunnel (const struct MeshConnection *c)
2196 * Get free buffer space in a connection.
2198 * @param c Connection.
2199 * @param fwd Is query about FWD traffic?
2201 * @return Free buffer space [0 - max_msgs_queue/max_connections]
2204 GMC_get_buffer (struct MeshConnection *c, int fwd)
2206 struct MeshFlowControl *fc;
2208 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2210 return (fc->queue_max - fc->queue_n);
2214 * Get how many messages have we allowed to send to us from a direction.
2216 * @param c Connection.
2217 * @param fwd Are we asking about traffic from FWD (BCK messages)?
2219 * @return last_ack_sent - last_pid_recv
2222 GMC_get_allowed (struct MeshConnection *c, int fwd)
2224 struct MeshFlowControl *fc;
2226 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2227 if (GMC_is_pid_bigger(fc->last_pid_recv, fc->last_ack_sent))
2231 return (fc->last_ack_sent - fc->last_pid_recv);
2235 * Get messages queued in a connection.
2237 * @param c Connection.
2238 * @param fwd Is query about FWD traffic?
2240 * @return Number of messages queued.
2243 GMC_get_qn (struct MeshConnection *c, int fwd)
2245 struct MeshFlowControl *fc;
2247 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2254 * Allow the connection to advertise a buffer of the given size.
2256 * The connection will send an @c fwd ACK message (so: in direction !fwd)
2257 * allowing up to last_pid_recv + buffer.
2259 * @param c Connection.
2260 * @param buffer How many more messages the connection can accept.
2261 * @param fwd Is this about FWD traffic? (The ack will go dest->root).
2264 GMC_allow (struct MeshConnection *c, unsigned int buffer, int fwd)
2266 send_ack (c, buffer, fwd, GNUNET_NO);
2271 * Notify other peers on a connection of a broken link. Mark connections
2272 * to destroy after all traffic has been sent.
2274 * @param c Connection on which there has been a disconnection.
2275 * @param peer Peer that disconnected.
2278 GMC_notify_broken (struct MeshConnection *c,
2279 struct MeshPeer *peer)
2283 fwd = peer == get_prev_hop (c);
2285 if (GNUNET_YES == GMC_is_terminal (c, fwd))
2287 /* Local shutdown, no one to notify about this. */
2291 if (GNUNET_NO == c->destroy)
2292 send_broken (c, &my_full_id, GMP_get_id (peer), fwd);
2294 /* Connection will have at least one pending message
2295 * (the one we just scheduled), so no point in checking whether to
2296 * destroy immediately. */
2297 c->destroy = GNUNET_YES;
2300 * Cancel all queues, if no message is left, connection will be destroyed.
2302 connection_cancel_queues (c, !fwd);
2309 * Is this peer the first one on the connection?
2311 * @param c Connection.
2312 * @param fwd Is this about fwd traffic?
2314 * @return #GNUNET_YES if origin, #GNUNET_NO if relay/terminal.
2317 GMC_is_origin (struct MeshConnection *c, int fwd)
2319 if (!fwd && c->path->length - 1 == c->own_pos )
2321 if (fwd && 0 == c->own_pos)
2328 * Is this peer the last one on the connection?
2330 * @param c Connection.
2331 * @param fwd Is this about fwd traffic?
2332 * Note that the ROOT is the terminal for BCK traffic!
2334 * @return #GNUNET_YES if terminal, #GNUNET_NO if relay/origin.
2337 GMC_is_terminal (struct MeshConnection *c, int fwd)
2339 return GMC_is_origin (c, !fwd);
2344 * See if we are allowed to send by the next hop in the given direction.
2346 * @param c Connection.
2347 * @param fwd Is this about fwd traffic?
2349 * @return #GNUNET_YES in case it's OK to send.
2352 GMC_is_sendable (struct MeshConnection *c, int fwd)
2354 struct MeshFlowControl *fc;
2356 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2357 if (GMC_is_pid_bigger (fc->last_ack_recv, fc->last_pid_sent))
2363 * Sends an already built message on a connection, properly registering
2364 * all used resources.
2366 * @param message Message to send. Function makes a copy of it.
2367 * If message is not hop-by-hop, decrements TTL of copy.
2368 * @param c Connection on which this message is transmitted.
2369 * @param fwd Is this a fwd message?
2370 * @param cont Continuation called once message is sent. Can be NULL.
2371 * @param cont_cls Closure for @c cont.
2373 * @return Handle to cancel the message before it's sent. NULL on error.
2374 * Invalid on @c cont call.
2376 struct MeshConnectionQueue *
2377 GMC_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2378 struct MeshConnection *c, int fwd,
2379 GMC_sent cont, void *cont_cls)
2381 struct MeshFlowControl *fc;
2382 struct MeshConnectionQueue *q;
2388 size = ntohs (message->size);
2389 data = GNUNET_malloc (size);
2390 memcpy (data, message, size);
2391 type = ntohs (message->type);
2392 LOG (GNUNET_ERROR_TYPE_DEBUG, "Send %s (%u bytes) on connection %s\n",
2393 GNUNET_MESH_DEBUG_M2S (type), size, GMC_2s (c));
2395 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2396 droppable = GNUNET_YES;
2399 struct GNUNET_MESH_Encrypted *emsg;
2400 struct GNUNET_MESH_KX *kmsg;
2401 struct GNUNET_MESH_ACK *amsg;
2402 struct GNUNET_MESH_Poll *pmsg;
2403 struct GNUNET_MESH_ConnectionDestroy *dmsg;
2404 struct GNUNET_MESH_ConnectionBroken *bmsg;
2407 case GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED:
2408 emsg = (struct GNUNET_MESH_Encrypted *) data;
2409 ttl = ntohl (emsg->ttl);
2412 GNUNET_break_op (0);
2417 emsg->ttl = htonl (ttl - 1);
2418 emsg->pid = htonl (fc->next_pid++);
2419 LOG (GNUNET_ERROR_TYPE_DEBUG, " Q_N+ %p %u\n", fc, fc->queue_n);
2421 LOG (GNUNET_ERROR_TYPE_DEBUG, "pid %u\n", ntohl (emsg->pid));
2422 LOG (GNUNET_ERROR_TYPE_DEBUG, "last pid sent %u\n", fc->last_pid_sent);
2423 LOG (GNUNET_ERROR_TYPE_DEBUG, " ack recv %u\n", fc->last_ack_recv);
2424 if (GMC_is_pid_bigger (fc->last_pid_sent + 1, fc->last_ack_recv))
2426 GMC_start_poll (c, fwd);
2430 case GNUNET_MESSAGE_TYPE_MESH_KX:
2431 kmsg = (struct GNUNET_MESH_KX *) data;
2435 case GNUNET_MESSAGE_TYPE_MESH_ACK:
2436 amsg = (struct GNUNET_MESH_ACK *) data;
2438 LOG (GNUNET_ERROR_TYPE_DEBUG, " ack %u\n", ntohl (amsg->ack));
2439 droppable = GNUNET_NO;
2442 case GNUNET_MESSAGE_TYPE_MESH_POLL:
2443 pmsg = (struct GNUNET_MESH_Poll *) data;
2445 LOG (GNUNET_ERROR_TYPE_DEBUG, " poll %u\n", ntohl (pmsg->pid));
2446 droppable = GNUNET_NO;
2449 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_DESTROY:
2450 dmsg = (struct GNUNET_MESH_ConnectionDestroy *) data;
2455 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_BROKEN:
2456 bmsg = (struct GNUNET_MESH_ConnectionBroken *) data;
2461 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_CREATE:
2462 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_ACK:
2469 if (fc->queue_n > fc->queue_max && droppable)
2471 GNUNET_STATISTICS_update (stats, "# messages dropped (buffer full)",
2474 LOG (GNUNET_ERROR_TYPE_DEBUG,
2475 "queue full: %u/%u\n",
2476 fc->queue_n, fc->queue_max);
2477 if (GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED == type)
2483 return NULL; /* Drop this message */
2486 LOG (GNUNET_ERROR_TYPE_DEBUG, " C_P+ %p %u\n", c, c->pending_messages);
2487 c->pending_messages++;
2489 q = GNUNET_new (struct MeshConnectionQueue);
2490 q->q = GMP_queue_add (get_hop (c, fwd), data, type, size, c, fwd,
2500 q->cont_cls = cont_cls;
2506 * Cancel a previously sent message while it's in the queue.
2508 * ONLY can be called before the continuation given to the send function
2509 * is called. Once the continuation is called, the message is no longer in the
2512 * If the send function was given no continuation, GMC_cancel should
2513 * NOT be called, since it's not possible to determine if the message has
2514 * already been sent.
2516 * @param q Handle to the queue.
2519 GMC_cancel (struct MeshConnectionQueue *q)
2521 LOG (GNUNET_ERROR_TYPE_DEBUG, "! GMC cancel message\n");
2523 /* queue destroy calls message_sent, which calls q->cont and frees q */
2524 GMP_queue_destroy (q->q, GNUNET_YES);
2529 * Sends a CREATE CONNECTION message for a path to a peer.
2530 * Changes the connection and tunnel states if necessary.
2532 * @param connection Connection to create.
2535 GMC_send_create (struct MeshConnection *connection)
2537 enum MeshTunnel3State state;
2540 size = sizeof (struct GNUNET_MESH_ConnectionCreate);
2541 size += connection->path->length * sizeof (struct GNUNET_PeerIdentity);
2542 LOG (GNUNET_ERROR_TYPE_DEBUG, "Send connection create\n");
2543 GMP_queue_add (get_next_hop (connection), NULL,
2544 GNUNET_MESSAGE_TYPE_MESH_CONNECTION_CREATE,
2545 size, connection, GNUNET_YES, &message_sent, NULL);
2546 LOG (GNUNET_ERROR_TYPE_DEBUG, " C_P+ %p %u (create)\n",
2547 connection, connection->pending_messages);
2548 connection->pending_messages++;
2549 state = GMT_get_state (connection->t);
2550 if (MESH_TUNNEL3_SEARCHING == state || MESH_TUNNEL3_NEW == state)
2551 GMT_change_state (connection->t, MESH_TUNNEL3_WAITING);
2552 if (MESH_CONNECTION_NEW == connection->state)
2553 connection_change_state (connection, MESH_CONNECTION_SENT);
2558 * Send a message to all peers in this connection that the connection
2559 * is no longer valid.
2561 * If some peer should not receive the message, it should be zero'ed out
2562 * before calling this function.
2564 * @param c The connection whose peers to notify.
2567 GMC_send_destroy (struct MeshConnection *c)
2569 struct GNUNET_MESH_ConnectionDestroy msg;
2571 if (GNUNET_YES == c->destroy)
2574 msg.header.size = htons (sizeof (msg));
2575 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CONNECTION_DESTROY);;
2577 LOG (GNUNET_ERROR_TYPE_DEBUG,
2578 " sending connection destroy for connection %s\n",
2581 if (GNUNET_NO == GMC_is_terminal (c, GNUNET_YES))
2582 GMC_send_prebuilt_message (&msg.header, c, GNUNET_YES, NULL, NULL);
2583 if (GNUNET_NO == GMC_is_terminal (c, GNUNET_NO))
2584 GMC_send_prebuilt_message (&msg.header, c, GNUNET_NO, NULL, NULL);
2585 c->destroy = GNUNET_YES;
2590 * @brief Start a polling timer for the connection.
2592 * When a neighbor does not accept more traffic on the connection it could be
2593 * caused by a simple congestion or by a lost ACK. Polling enables to check
2594 * for the lastest ACK status for a connection.
2596 * @param c Connection.
2597 * @param fwd Should we poll in the FWD direction?
2600 GMC_start_poll (struct MeshConnection *c, int fwd)
2602 struct MeshFlowControl *fc;
2604 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2605 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task && NULL != fc->poll_msg)
2609 fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time,
2616 * @brief Stop polling a connection for ACKs.
2618 * Once we have enough ACKs for future traffic, polls are no longer necessary.
2620 * @param c Connection.
2621 * @param fwd Should we stop the poll in the FWD direction?
2624 GMC_stop_poll (struct MeshConnection *c, int fwd)
2626 struct MeshFlowControl *fc;
2628 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2629 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task)
2631 GNUNET_SCHEDULER_cancel (fc->poll_task);
2632 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
2637 * Get a (static) string for a connection.
2639 * @param c Connection.
2642 GMC_2s (struct MeshConnection *c)
2646 static char buf[128];
2648 sprintf (buf, "%s (->%s)", GNUNET_h2s (&c->id), GMT_2s (c->t));
2651 return GNUNET_h2s (&c->id);