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.
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,
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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, "! Q_N- %p %u\n", fc, fc->queue_n);
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:
462 LOG (GNUNET_ERROR_TYPE_DEBUG,
463 "! accounting pid %u\n",
465 GMC_send_ack (c, fwd);
470 LOG (GNUNET_ERROR_TYPE_DEBUG, "! message sent!\n");
473 return; /* Only endpoints are interested in timing. */
476 usecsperbyte = ((double) wait.rel_value_us) / size;
477 if (p->size == AVG_MSGS)
479 /* Array is full. Substract oldest value, add new one and store. */
480 p->avg -= (p->usecsperbyte[p->idx] / AVG_MSGS);
481 p->usecsperbyte[p->idx] = usecsperbyte;
482 p->avg += (p->usecsperbyte[p->idx] / AVG_MSGS);
486 /* Array not yet full. Add current value to avg and store. */
487 p->usecsperbyte[p->idx] = usecsperbyte;
489 p->avg += p->usecsperbyte[p->idx];
493 p->idx = (p->idx + 1) % AVG_MSGS;
495 // if (NULL != c->t) FIXME
497 // c->t->pending_messages--;
498 // if (GNUNET_YES == c->t->destroy && 0 == t->pending_messages)
500 // LOG (GNUNET_ERROR_TYPE_DEBUG, "* destroying tunnel!\n");
501 // GMT_destroy (c->t);
508 * Get the previous hop in a connection
510 * @param c Connection.
512 * @return Previous peer in the connection.
514 static struct MeshPeer *
515 get_prev_hop (const struct MeshConnection *c)
519 LOG (GNUNET_ERROR_TYPE_DEBUG, "Get prev hop, own pos %u\n", c->own_pos);
520 if (0 == c->own_pos || c->path->length < 2)
521 id = c->path->peers[0];
523 id = c->path->peers[c->own_pos - 1];
525 return GMP_get_short (id);
530 * Get the next hop in a connection
532 * @param c Connection.
534 * @return Next peer in the connection.
536 static struct MeshPeer *
537 get_next_hop (const struct MeshConnection *c)
541 if ((c->path->length - 1) == c->own_pos || c->path->length < 2)
542 id = c->path->peers[c->path->length - 1];
544 id = c->path->peers[c->own_pos + 1];
546 return GMP_get_short (id);
551 * Get the hop in a connection.
553 * @param c Connection.
554 * @param fwd Next hop?
556 * @return Next peer in the connection.
558 static struct MeshPeer *
559 get_hop (struct MeshConnection *c, int fwd)
562 return get_next_hop (c);
563 return get_prev_hop (c);
568 * Is traffic coming from this sender 'FWD' traffic?
570 * @param c Connection to check.
571 * @param sender Peer identity of neighbor.
573 * @return GNUNET_YES in case the sender is the 'prev' hop and therefore
574 * the traffic is 'FWD'. GNUNET_NO for BCK. GNUNET_SYSERR for errors.
577 is_fwd (const struct MeshConnection *c,
578 const struct GNUNET_PeerIdentity *sender)
582 id = GNUNET_PEER_search (sender);
583 if (GMP_get_short_id (get_prev_hop (c)) == id)
586 if (GMP_get_short_id (get_next_hop (c)) == id)
590 return GNUNET_SYSERR;
595 * Sends a CONNECTION ACK message in reponse to a received CONNECTION_CREATE
596 * or a first CONNECTION_ACK directed to us.
598 * @param connection Connection to confirm.
599 * @param fwd Should we send it FWD? (root->dest)
600 * (First (~SYNACK) goes BCK, second (~ACK) goes FWD)
603 send_connection_ack (struct MeshConnection *connection, int fwd)
605 struct MeshTunnel3 *t;
608 LOG (GNUNET_ERROR_TYPE_DEBUG, "Send connection %s ACK\n",
609 !fwd ? "FWD" : "BCK");
610 GMP_queue_add (get_hop (connection, fwd), NULL,
611 GNUNET_MESSAGE_TYPE_MESH_CONNECTION_ACK,
612 sizeof (struct GNUNET_MESH_ConnectionACK),
613 connection, fwd, &message_sent, NULL);
614 if (MESH_TUNNEL3_NEW == GMT_get_state (t))
615 GMT_change_state (t, MESH_TUNNEL3_WAITING);
616 if (MESH_CONNECTION_READY != connection->state)
617 connection_change_state (connection, MESH_CONNECTION_SENT);
622 * Send a notification that a connection is broken.
624 * @param c Connection that is broken.
625 * @param id1 Peer that has disconnected.
626 * @param id2 Peer that has disconnected.
627 * @param fwd Direction towards which to send it.
630 send_broken (struct MeshConnection *c,
631 const struct GNUNET_PeerIdentity *id1,
632 const struct GNUNET_PeerIdentity *id2,
635 struct GNUNET_MESH_ConnectionBroken msg;
637 msg.header.size = htons (sizeof (struct GNUNET_MESH_ConnectionBroken));
638 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CONNECTION_BROKEN);
642 GMC_send_prebuilt_message (&msg.header, c, fwd);
648 * Send keepalive packets for a connection.
650 * @param c Connection to keep alive..
651 * @param fwd Is this a FWD keepalive? (owner -> dest).
654 connection_keepalive (struct MeshConnection *c, int fwd)
656 struct GNUNET_MESH_ConnectionKeepAlive *msg;
657 size_t size = sizeof (struct GNUNET_MESH_ConnectionKeepAlive);
661 type = fwd ? GNUNET_MESSAGE_TYPE_MESH_FWD_KEEPALIVE :
662 GNUNET_MESSAGE_TYPE_MESH_BCK_KEEPALIVE;
664 LOG (GNUNET_ERROR_TYPE_DEBUG,
665 "sending %s keepalive for connection %s]\n",
666 fwd ? "FWD" : "BCK", GMC_2s (c));
668 msg = (struct GNUNET_MESH_ConnectionKeepAlive *) cbuf;
669 msg->header.size = htons (size);
670 msg->header.type = htons (type);
673 GMC_send_prebuilt_message (&msg->header, c, fwd);
678 * Send CONNECTION_{CREATE/ACK} packets for a connection.
680 * @param c Connection for which to send the message.
681 * @param fwd If GNUNET_YES, send CREATE, otherwise send ACK.
684 connection_recreate (struct MeshConnection *c, int fwd)
686 LOG (GNUNET_ERROR_TYPE_DEBUG, "sending connection recreate\n");
690 send_connection_ack (c, GNUNET_NO);
695 * Generic connection timer management.
696 * Depending on the role of the peer in the connection will send the
697 * appropriate message (build or keepalive)
699 * @param c Conncetion to maintain.
703 connection_maintain (struct MeshConnection *c, int fwd)
705 if (MESH_TUNNEL3_SEARCHING == GMT_get_state (c->t))
707 /* TODO DHT GET with RO_BART */
712 case MESH_CONNECTION_NEW:
714 case MESH_CONNECTION_SENT:
715 connection_recreate (c, fwd);
717 case MESH_CONNECTION_READY:
718 connection_keepalive (c, fwd);
727 connection_fwd_keepalive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
729 struct MeshConnection *c = cls;
731 c->fwd_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
732 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
735 connection_maintain (c, GNUNET_YES);
736 c->fwd_maintenance_task = GNUNET_SCHEDULER_add_delayed (refresh_connection_time,
737 &connection_fwd_keepalive,
743 connection_bck_keepalive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
745 struct MeshConnection *c = cls;
747 c->bck_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
748 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
751 connection_maintain (c, GNUNET_NO);
752 c->bck_maintenance_task = GNUNET_SCHEDULER_add_delayed (refresh_connection_time,
753 &connection_bck_keepalive,
759 * @brief Re-initiate traffic on this connection if necessary.
761 * Check if there is traffic queued towards this peer
762 * and the core transmit handle is NULL (traffic was stalled).
763 * If so, call core tmt rdy.
765 * @param c Connection on which initiate traffic.
766 * @param fwd Is this about fwd traffic?
769 connection_unlock_queue (struct MeshConnection *c, int fwd)
771 struct MeshPeer *peer;
773 LOG (GNUNET_ERROR_TYPE_DEBUG,
774 "connection_unlock_queue %s on %s\n",
775 fwd ? "FWD" : "BCK", GMC_2s (c));
777 if (GMC_is_terminal (c, fwd))
779 LOG (GNUNET_ERROR_TYPE_DEBUG, " is terminal!\n");
783 peer = get_hop (c, fwd);
784 GMP_queue_unlock (peer, c);
789 * Cancel all transmissions that belong to a certain connection.
791 * If the connection is scheduled for destruction and no more messages are left,
792 * the connection will be destroyed by the continuation call.
794 * @param c Connection which to cancel. Might be destroyed during this call.
795 * @param fwd Cancel fwd traffic?
798 connection_cancel_queues (struct MeshConnection *c, int fwd)
800 struct MeshFlowControl *fc;
801 struct MeshPeer *peer;
809 fc = fwd ? &c->fwd_fc : &c->bck_fc;
810 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task)
812 GNUNET_SCHEDULER_cancel (fc->poll_task);
813 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
815 peer = get_hop (c, fwd);
816 GMP_queue_cancel (peer, c);
821 * Function called if a connection has been stalled for a while,
822 * possibly due to a missed ACK. Poll the neighbor about its ACK status.
824 * @param cls Closure (poll ctx).
825 * @param tc TaskContext.
828 connection_poll (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
830 struct MeshFlowControl *fc = cls;
831 struct GNUNET_MESH_Poll msg;
832 struct MeshConnection *c;
834 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
835 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
841 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** Polling!\n");
842 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** connection [%s]\n", GMC_2s (c));
843 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** %s\n",
844 fc == &c->fwd_fc ? "FWD" : "BCK");
846 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_POLL);
847 msg.header.size = htons (sizeof (msg));
848 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** pid (%u)!\n", fc->last_pid_sent);
849 GMC_send_prebuilt_message (&msg.header, c, fc == &c->fwd_fc);
850 fc->poll_time = GNUNET_TIME_STD_BACKOFF (fc->poll_time);
851 fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time,
852 &connection_poll, fc);
857 * Timeout function due to lack of keepalive/traffic from the owner.
858 * Destroys connection if called.
860 * @param cls Closure (connection to destroy).
861 * @param tc TaskContext.
864 connection_fwd_timeout (void *cls,
865 const struct GNUNET_SCHEDULER_TaskContext *tc)
867 struct MeshConnection *c = cls;
869 c->fwd_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
870 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
872 LOG (GNUNET_ERROR_TYPE_DEBUG,
873 "Connection %s[%X] FWD timed out. Destroying.\n",
877 if (GMC_is_origin (c, GNUNET_YES)) /* If local, leave. */
885 * Timeout function due to lack of keepalive/traffic from the destination.
886 * Destroys connection if called.
888 * @param cls Closure (connection to destroy).
889 * @param tc TaskContext
892 connection_bck_timeout (void *cls,
893 const struct GNUNET_SCHEDULER_TaskContext *tc)
895 struct MeshConnection *c = cls;
897 c->bck_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
898 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
901 LOG (GNUNET_ERROR_TYPE_DEBUG,
902 "Connection %s[%X] FWD timed out. Destroying.\n",
903 GMT_2s (c->t), c->id);
905 if (GMC_is_origin (c, GNUNET_NO)) /* If local, leave. */
913 * Resets the connection timeout task, some other message has done the
915 * - For the first peer on the direction this means to send
916 * a keepalive or a path confirmation message (either create or ACK).
917 * - For all other peers, this means to destroy the connection,
918 * due to lack of activity.
919 * Starts the tiemout if no timeout was running (connection just created).
921 * @param c Connection whose timeout to reset.
922 * @param fwd Is this forward?
924 * TODO use heap to improve efficiency of scheduler.
927 connection_reset_timeout (struct MeshConnection *c, int fwd)
929 GNUNET_SCHEDULER_TaskIdentifier *ti;
930 GNUNET_SCHEDULER_Task f;
932 ti = fwd ? &c->fwd_maintenance_task : &c->bck_maintenance_task;
934 if (GNUNET_SCHEDULER_NO_TASK != *ti)
935 GNUNET_SCHEDULER_cancel (*ti);
937 if (GMC_is_origin (c, fwd)) /* Endpoint */
939 f = fwd ? &connection_fwd_keepalive : &connection_bck_keepalive;
940 *ti = GNUNET_SCHEDULER_add_delayed (refresh_connection_time, f, c);
944 struct GNUNET_TIME_Relative delay;
946 delay = GNUNET_TIME_relative_multiply (refresh_connection_time, 4);
947 f = fwd ? &connection_fwd_timeout : &connection_bck_timeout;
948 *ti = GNUNET_SCHEDULER_add_delayed (delay, f, c);
954 * Add the connection to the list of both neighbors.
956 * @param c Connection.
959 register_neighbors (struct MeshConnection *c)
961 struct MeshPeer *peer;
963 peer = get_next_hop (c);
964 if (GNUNET_NO == GMP_is_neighbor (peer))
969 GMP_add_connection (peer, c);
970 peer = get_prev_hop (c);
971 if (GNUNET_NO == GMP_is_neighbor (peer))
976 GMP_add_connection (peer, c);
981 * Remove the connection from the list of both neighbors.
983 * @param c Connection.
986 unregister_neighbors (struct MeshConnection *c)
988 struct MeshPeer *peer;
990 peer = get_next_hop (c);
991 GMP_remove_connection (peer, c);
993 peer = get_prev_hop (c);
994 GMP_remove_connection (peer, c);
1000 * Bind the connection to the peer and the tunnel to that peer.
1002 * If the peer has no tunnel, create one. Update tunnel and connection
1003 * data structres to reflect new status.
1005 * @param c Connection.
1009 add_to_peer (struct MeshConnection *c, struct MeshPeer *peer)
1011 GMP_add_tunnel (peer);
1012 c->t = GMP_get_tunnel (peer);
1013 GMT_add_connection (c->t, c);
1016 /******************************************************************************/
1017 /******************************** API ***********************************/
1018 /******************************************************************************/
1021 * Core handler for connection creation.
1023 * @param cls Closure (unused).
1024 * @param peer Sender (neighbor).
1025 * @param message Message.
1027 * @return GNUNET_OK to keep the connection open,
1028 * GNUNET_SYSERR to close it (signal serious error)
1031 GMC_handle_create (void *cls, const struct GNUNET_PeerIdentity *peer,
1032 const struct GNUNET_MessageHeader *message)
1034 struct GNUNET_MESH_ConnectionCreate *msg;
1035 struct GNUNET_PeerIdentity *id;
1036 struct GNUNET_HashCode *cid;
1037 struct MeshPeerPath *path;
1038 struct MeshPeer *dest_peer;
1039 struct MeshPeer *orig_peer;
1040 struct MeshConnection *c;
1041 unsigned int own_pos;
1045 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1046 LOG (GNUNET_ERROR_TYPE_DEBUG, "Received a connection create msg\n");
1049 size = ntohs (message->size);
1050 if (size < sizeof (struct GNUNET_MESH_ConnectionCreate))
1052 GNUNET_break_op (0);
1056 /* Calculate hops */
1057 size -= sizeof (struct GNUNET_MESH_ConnectionCreate);
1058 if (size % sizeof (struct GNUNET_PeerIdentity))
1060 GNUNET_break_op (0);
1063 size /= sizeof (struct GNUNET_PeerIdentity);
1066 GNUNET_break_op (0);
1069 LOG (GNUNET_ERROR_TYPE_DEBUG, " path has %u hops.\n", size);
1071 /* Get parameters */
1072 msg = (struct GNUNET_MESH_ConnectionCreate *) message;
1074 id = (struct GNUNET_PeerIdentity *) &msg[1];
1075 LOG (GNUNET_ERROR_TYPE_DEBUG,
1076 " connection %s (%s).\n",
1077 GNUNET_h2s (cid), GNUNET_i2s (id));
1079 /* Create connection */
1080 c = connection_get (cid);
1084 LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating path...\n");
1085 path = path_new (size);
1087 for (i = 0; i < size; i++)
1089 LOG (GNUNET_ERROR_TYPE_DEBUG, " ... adding %s\n",
1090 GNUNET_i2s (&id[i]));
1091 path->peers[i] = GNUNET_PEER_intern (&id[i]);
1092 if (path->peers[i] == myid)
1095 if (own_pos == 0 && path->peers[own_pos] != myid)
1097 /* create path: self not found in path through self */
1098 GNUNET_break_op (0);
1099 path_destroy (path);
1102 LOG (GNUNET_ERROR_TYPE_DEBUG, " Own position: %u\n", own_pos);
1103 GMP_add_path_to_all (path, GNUNET_NO);
1104 LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating connection\n");
1105 c = GMC_new (cid, NULL, path_duplicate (path), own_pos);
1108 connection_reset_timeout (c, GNUNET_YES);
1114 if (MESH_CONNECTION_NEW == c->state)
1115 connection_change_state (c, MESH_CONNECTION_SENT);
1117 /* Remember peers */
1118 dest_peer = GMP_get (&id[size - 1]);
1119 orig_peer = GMP_get (&id[0]);
1121 /* Is it a connection to us? */
1122 if (c->own_pos == size - 1)
1124 LOG (GNUNET_ERROR_TYPE_DEBUG, " It's for us!\n");
1125 GMP_add_path_to_origin (orig_peer, path, GNUNET_YES);
1127 add_to_peer (c, orig_peer);
1128 if (MESH_TUNNEL3_NEW == GMT_get_state (c->t))
1129 GMT_change_state (c->t, MESH_TUNNEL3_WAITING);
1131 send_connection_ack (c, GNUNET_NO);
1132 if (MESH_CONNECTION_SENT == c->state)
1133 connection_change_state (c, MESH_CONNECTION_ACK);
1135 /* Keep tunnel alive in direction dest->owner*/
1136 connection_reset_timeout (c, GNUNET_NO);
1140 /* It's for somebody else! Retransmit. */
1141 LOG (GNUNET_ERROR_TYPE_DEBUG, " Retransmitting.\n");
1142 GMP_add_path (dest_peer, path_duplicate (path), GNUNET_NO);
1143 GMP_add_path_to_origin (orig_peer, path, GNUNET_NO);
1144 GMC_send_prebuilt_message (message, c, GNUNET_YES);
1151 * Core handler for path confirmations.
1153 * @param cls closure
1154 * @param message message
1155 * @param peer peer identity this notification is about
1157 * @return GNUNET_OK to keep the connection open,
1158 * GNUNET_SYSERR to close it (signal serious error)
1161 GMC_handle_confirm (void *cls, const struct GNUNET_PeerIdentity *peer,
1162 const struct GNUNET_MessageHeader *message)
1164 struct GNUNET_MESH_ConnectionACK *msg;
1165 struct MeshConnection *c;
1166 struct MeshPeerPath *p;
1167 struct MeshPeer *pi;
1170 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1171 LOG (GNUNET_ERROR_TYPE_DEBUG, "Received a connection ACK msg\n");
1172 msg = (struct GNUNET_MESH_ConnectionACK *) message;
1173 LOG (GNUNET_ERROR_TYPE_DEBUG, " on connection %s\n",
1174 GNUNET_h2s (&msg->cid));
1175 c = connection_get (&msg->cid);
1178 GNUNET_STATISTICS_update (stats, "# control on unknown connection",
1180 LOG (GNUNET_ERROR_TYPE_DEBUG, " don't know the connection!\n");
1185 LOG (GNUNET_ERROR_TYPE_DEBUG, " via peer %s\n",
1187 pi = GMP_get (peer);
1188 if (get_next_hop (c) == pi)
1190 LOG (GNUNET_ERROR_TYPE_DEBUG, " SYNACK\n");
1192 if (MESH_CONNECTION_SENT == c->state)
1193 connection_change_state (c, MESH_CONNECTION_ACK);
1195 else if (get_prev_hop (c) == pi)
1197 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK\n");
1199 connection_change_state (c, MESH_CONNECTION_READY);
1203 GNUNET_break_op (0);
1206 connection_reset_timeout (c, fwd);
1208 /* Add path to peers? */
1212 GMP_add_path_to_all (p, GNUNET_YES);
1219 /* Message for us as creator? */
1220 if (GMC_is_origin (c, GNUNET_YES))
1222 LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection (SYN)ACK for us!\n");
1223 connection_change_state (c, MESH_CONNECTION_READY);
1224 GMT_change_state (c->t, MESH_TUNNEL3_READY);
1225 send_connection_ack (c, GNUNET_YES);
1226 GMT_send_queued_data (c->t, GNUNET_YES);
1230 /* Message for us as destination? */
1231 if (GMC_is_terminal (c, GNUNET_YES))
1233 LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection ACK for us!\n");
1234 connection_change_state (c, MESH_CONNECTION_READY);
1235 GMT_change_state (c->t, MESH_TUNNEL3_READY);
1236 GMT_send_queued_data (c->t, GNUNET_NO);
1240 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
1241 GMC_send_prebuilt_message (message, c, fwd);
1247 * Core handler for notifications of broken paths
1249 * @param cls Closure (unused).
1250 * @param id Peer identity of sending neighbor.
1251 * @param message Message.
1253 * @return GNUNET_OK to keep the connection open,
1254 * GNUNET_SYSERR to close it (signal serious error)
1257 GMC_handle_broken (void* cls,
1258 const struct GNUNET_PeerIdentity* id,
1259 const struct GNUNET_MessageHeader* message)
1261 struct GNUNET_MESH_ConnectionBroken *msg;
1262 struct MeshConnection *c;
1265 LOG (GNUNET_ERROR_TYPE_DEBUG,
1266 "Received a CONNECTION BROKEN msg from %s\n", GNUNET_i2s (id));
1267 msg = (struct GNUNET_MESH_ConnectionBroken *) message;
1268 LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n",
1269 GNUNET_i2s (&msg->peer1));
1270 LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n",
1271 GNUNET_i2s (&msg->peer2));
1272 c = connection_get (&msg->cid);
1275 GNUNET_break_op (0);
1279 fwd = is_fwd (c, id);
1280 connection_cancel_queues (c, !fwd);
1281 if (GMC_is_terminal (c, fwd))
1283 if (0 < c->pending_messages)
1284 c->destroy = GNUNET_YES;
1290 GMC_send_prebuilt_message (message, c, fwd);
1291 c->destroy = GNUNET_YES;
1300 * Core handler for tunnel destruction
1302 * @param cls Closure (unused).
1303 * @param peer Peer identity of sending neighbor.
1304 * @param message Message.
1306 * @return GNUNET_OK to keep the connection open,
1307 * GNUNET_SYSERR to close it (signal serious error)
1310 GMC_handle_destroy (void *cls, const struct GNUNET_PeerIdentity *peer,
1311 const struct GNUNET_MessageHeader *message)
1313 struct GNUNET_MESH_ConnectionDestroy *msg;
1314 struct MeshConnection *c;
1317 msg = (struct GNUNET_MESH_ConnectionDestroy *) message;
1318 LOG (GNUNET_ERROR_TYPE_DEBUG,
1319 "Got a CONNECTION DESTROY message from %s\n",
1321 LOG (GNUNET_ERROR_TYPE_DEBUG,
1322 " for connection %s\n",
1323 GNUNET_h2s (&msg->cid));
1324 c = connection_get (&msg->cid);
1327 /* Probably already got the message from another path,
1328 * destroyed the tunnel and retransmitted to children.
1331 GNUNET_STATISTICS_update (stats, "# control on unknown tunnel",
1335 fwd = is_fwd (c, peer);
1336 if (GNUNET_SYSERR == fwd)
1338 GNUNET_break_op (0);
1341 GMC_send_prebuilt_message (message, c, fwd);
1342 c->destroy = GNUNET_YES;
1348 * Generic handler for mesh network encrypted traffic.
1350 * @param peer Peer identity this notification is about.
1351 * @param msg Encrypted message.
1353 * @return GNUNET_OK to keep the connection open,
1354 * GNUNET_SYSERR to close it (signal serious error)
1357 handle_mesh_encrypted (const struct GNUNET_PeerIdentity *peer,
1358 const struct GNUNET_MESH_Encrypted *msg)
1360 struct MeshConnection *c;
1361 struct MeshPeer *neighbor;
1362 struct MeshFlowControl *fc;
1363 GNUNET_PEER_Id peer_id;
1371 size = ntohs (msg->header.size);
1373 sizeof (struct GNUNET_MESH_Encrypted) +
1374 sizeof (struct GNUNET_MessageHeader))
1376 GNUNET_break_op (0);
1379 type = ntohs (msg->header.type);
1380 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1381 LOG (GNUNET_ERROR_TYPE_DEBUG, "got a %s message from %s\n",
1382 GNUNET_MESH_DEBUG_M2S (type), GNUNET_i2s (peer));
1384 /* Check connection */
1385 c = connection_get (&msg->cid);
1388 GNUNET_STATISTICS_update (stats, "# unknown connection", 1, GNUNET_NO);
1389 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING connection unknown\n");
1393 /* Check if origin is as expected */
1394 neighbor = get_prev_hop (c);
1395 peer_id = GNUNET_PEER_search (peer);
1396 if (peer_id == GMP_get_short_id (neighbor))
1402 neighbor = get_next_hop (c);
1403 if (peer_id == GMP_get_short_id (neighbor))
1409 /* Unexpected peer sending traffic on a connection. */
1410 GNUNET_break_op (0);
1416 fc = fwd ? &c->bck_fc : &c->fwd_fc;
1417 pid = ntohl (msg->pid);
1418 if (GMC_is_pid_bigger (pid, fc->last_ack_sent))
1420 GNUNET_STATISTICS_update (stats, "# unsolicited message", 1, GNUNET_NO);
1421 LOG (GNUNET_ERROR_TYPE_DEBUG,
1422 "WARNING Received PID %u, (prev %u), ACK %u\n",
1423 pid, fc->last_pid_recv, fc->last_ack_sent);
1426 if (GNUNET_NO == GMC_is_pid_bigger (pid, fc->last_pid_recv))
1428 GNUNET_STATISTICS_update (stats, "# duplicate PID", 1, GNUNET_NO);
1429 LOG (GNUNET_ERROR_TYPE_DEBUG,
1430 " Pid %u not expected (%u+), dropping!\n",
1431 pid, fc->last_pid_recv + 1);
1434 if (MESH_CONNECTION_SENT == c->state || MESH_CONNECTION_ACK == c->state)
1435 connection_change_state (c, MESH_CONNECTION_READY);
1436 connection_reset_timeout (c, fwd);
1437 fc->last_pid_recv = pid;
1439 /* Is this message for us? */
1440 if (GMC_is_terminal (c, fwd))
1442 /* TODO signature verification */
1443 LOG (GNUNET_ERROR_TYPE_DEBUG, " message for us!\n");
1444 GNUNET_STATISTICS_update (stats, "# messages received", 1, GNUNET_NO);
1451 fc->last_pid_recv = pid;
1452 GMT_handle_encrypted (c->t, msg, fwd);
1453 GMC_send_ack (c, fwd);
1457 /* Message not for us: forward to next hop */
1458 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
1459 ttl = ntohl (msg->ttl);
1460 LOG (GNUNET_ERROR_TYPE_DEBUG, " ttl: %u\n", ttl);
1463 GNUNET_STATISTICS_update (stats, "# TTL drops", 1, GNUNET_NO);
1464 LOG (GNUNET_ERROR_TYPE_WARNING, " TTL is 0, DROPPING!\n");
1465 GMC_send_ack (c, fwd);
1468 GNUNET_STATISTICS_update (stats, "# messages forwarded", 1, GNUNET_NO);
1470 GMC_send_prebuilt_message (&msg->header, c, fwd);
1477 * Core handler for encrypted mesh network traffic (channel mgmt, data).
1479 * @param cls Closure (unused).
1480 * @param message Message received.
1481 * @param peer Peer who sent the message.
1483 * @return GNUNET_OK to keep the connection open,
1484 * GNUNET_SYSERR to close it (signal serious error)
1487 GMC_handle_encrypted (void *cls, const struct GNUNET_PeerIdentity *peer,
1488 const struct GNUNET_MessageHeader *message)
1490 return handle_mesh_encrypted (peer,
1491 (struct GNUNET_MESH_Encrypted *)message);
1496 * Core handler for mesh network traffic point-to-point acks.
1498 * @param cls closure
1499 * @param message message
1500 * @param peer peer identity this notification is about
1502 * @return GNUNET_OK to keep the connection open,
1503 * GNUNET_SYSERR to close it (signal serious error)
1506 GMC_handle_ack (void *cls, const struct GNUNET_PeerIdentity *peer,
1507 const struct GNUNET_MessageHeader *message)
1509 struct GNUNET_MESH_ACK *msg;
1510 struct MeshConnection *c;
1511 struct MeshFlowControl *fc;
1516 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1517 LOG (GNUNET_ERROR_TYPE_DEBUG, "Got an ACK packet from %s!\n",
1519 msg = (struct GNUNET_MESH_ACK *) message;
1521 c = connection_get (&msg->cid);
1525 GNUNET_STATISTICS_update (stats, "# ack on unknown connection", 1,
1530 /* Is this a forward or backward ACK? */
1531 id = GNUNET_PEER_search (peer);
1532 if (GMP_get_short_id (get_next_hop (c)) == id)
1534 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD ACK\n");
1538 else if (GMP_get_short_id (get_prev_hop (c)) == id)
1540 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK ACK\n");
1546 GNUNET_break_op (0);
1550 ack = ntohl (msg->ack);
1551 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK %u (was %u)\n",
1552 ack, fc->last_ack_recv);
1553 if (GMC_is_pid_bigger (ack, fc->last_ack_recv))
1554 fc->last_ack_recv = ack;
1556 /* Cancel polling if the ACK is big enough. */
1557 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task &&
1558 GMC_is_pid_bigger (fc->last_ack_recv, fc->last_pid_sent))
1560 LOG (GNUNET_ERROR_TYPE_DEBUG, " Cancel poll\n");
1561 GNUNET_SCHEDULER_cancel (fc->poll_task);
1562 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
1563 fc->poll_time = GNUNET_TIME_UNIT_SECONDS;
1566 connection_unlock_queue (c, fwd);
1573 * Core handler for mesh network traffic point-to-point ack polls.
1575 * @param cls closure
1576 * @param message message
1577 * @param peer peer identity this notification is about
1579 * @return GNUNET_OK to keep the connection open,
1580 * GNUNET_SYSERR to close it (signal serious error)
1583 GMC_handle_poll (void *cls, const struct GNUNET_PeerIdentity *peer,
1584 const struct GNUNET_MessageHeader *message)
1586 struct GNUNET_MESH_Poll *msg;
1587 struct MeshConnection *c;
1588 struct MeshFlowControl *fc;
1593 LOG (GNUNET_ERROR_TYPE_DEBUG, "\n\n");
1594 LOG (GNUNET_ERROR_TYPE_DEBUG, "Got a POLL packet from %s!\n",
1597 msg = (struct GNUNET_MESH_Poll *) message;
1599 c = connection_get (&msg->cid);
1603 GNUNET_STATISTICS_update (stats, "# poll on unknown connection", 1,
1605 GNUNET_break_op (0);
1609 /* Is this a forward or backward ACK?
1610 * Note: a poll should never be needed in a loopback case,
1611 * since there is no possiblility of packet loss there, so
1612 * this way of discerining FWD/BCK should not be a problem.
1614 id = GNUNET_PEER_search (peer);
1615 if (GMP_get_short_id (get_next_hop (c)) == id)
1617 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD ACK\n");
1620 else if (GMP_get_short_id (get_prev_hop (c)) == id)
1622 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK ACK\n");
1627 GNUNET_break_op (0);
1631 pid = ntohl (msg->pid);
1632 LOG (GNUNET_ERROR_TYPE_DEBUG, " PID %u, OLD %u\n",
1633 pid, fc->last_pid_recv);
1634 fc->last_pid_recv = pid;
1635 fwd = fc == &c->fwd_fc;
1636 GMC_send_ack (c, fwd);
1643 * Core handler for mesh keepalives.
1645 * @param cls closure
1646 * @param message message
1647 * @param peer peer identity this notification is about
1648 * @return GNUNET_OK to keep the connection open,
1649 * GNUNET_SYSERR to close it (signal serious error)
1651 * TODO: Check who we got this from, to validate route.
1654 GMC_handle_keepalive (void *cls, const struct GNUNET_PeerIdentity *peer,
1655 const struct GNUNET_MessageHeader *message)
1657 struct GNUNET_MESH_ConnectionKeepAlive *msg;
1658 struct MeshConnection *c;
1659 struct MeshPeer *neighbor;
1662 msg = (struct GNUNET_MESH_ConnectionKeepAlive *) message;
1663 LOG (GNUNET_ERROR_TYPE_DEBUG, "got a keepalive packet from %s\n",
1666 c = connection_get (&msg->cid);
1669 GNUNET_STATISTICS_update (stats, "# keepalive on unknown connection", 1,
1674 fwd = GNUNET_MESSAGE_TYPE_MESH_FWD_KEEPALIVE == ntohs (message->type) ?
1675 GNUNET_YES : GNUNET_NO;
1677 /* Check if origin is as expected */
1678 neighbor = get_hop (c, fwd);
1679 if (GNUNET_PEER_search (peer) != GMP_get_short_id (neighbor))
1681 GNUNET_break_op (0);
1685 connection_change_state (c, MESH_CONNECTION_READY);
1686 connection_reset_timeout (c, fwd);
1688 if (GMC_is_terminal (c, fwd))
1691 GNUNET_STATISTICS_update (stats, "# keepalives forwarded", 1, GNUNET_NO);
1692 GMC_send_prebuilt_message (message, c, fwd);
1699 * Send an ACK on the appropriate connection/channel, depending on
1700 * the direction and the position of the peer.
1702 * @param c Which connection to send the hop-by-hop ACK.
1703 * @param fwd Is this a fwd ACK? (will go dest->root)
1706 GMC_send_ack (struct MeshConnection *c, int fwd)
1708 unsigned int buffer;
1710 LOG (GNUNET_ERROR_TYPE_DEBUG,
1711 "GMC send %s ACK on %s\n",
1712 fwd ? "FWD" : "BCK", GMC_2s (c));
1720 /* Get available buffer space */
1721 if (GMC_is_terminal (c, fwd))
1723 LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from all channels\n");
1724 buffer = GMT_get_buffer (c->t, fwd);
1728 LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from one connection\n");
1729 buffer = GMC_get_buffer (c, fwd);
1731 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer available: %u\n", buffer);
1733 /* Send available buffer space */
1734 if (GMC_is_origin (c, fwd))
1736 GNUNET_assert (NULL != c->t);
1737 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channels...\n");
1740 LOG (GNUNET_ERROR_TYPE_DEBUG, " really sending!\n");
1741 GMT_unchoke_channels (c->t, fwd);
1746 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on connection\n");
1747 send_ack (c, buffer, fwd);
1753 * Initialize the connections subsystem
1755 * @param c Configuration handle.
1758 GMC_init (const struct GNUNET_CONFIGURATION_Handle *c)
1760 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
1762 GNUNET_CONFIGURATION_get_value_number (c, "MESH", "MAX_MSGS_QUEUE",
1765 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
1766 "MESH", "MAX_MSGS_QUEUE", "MISSING");
1767 GNUNET_SCHEDULER_shutdown ();
1772 GNUNET_CONFIGURATION_get_value_number (c, "MESH", "MAX_CONNECTIONS",
1775 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
1776 "MESH", "MAX_CONNECTIONS", "MISSING");
1777 GNUNET_SCHEDULER_shutdown ();
1782 GNUNET_CONFIGURATION_get_value_time (c, "MESH", "REFRESH_CONNECTION_TIME",
1783 &refresh_connection_time))
1785 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
1786 "MESH", "REFRESH_CONNECTION_TIME", "MISSING");
1787 GNUNET_SCHEDULER_shutdown ();
1790 connections = GNUNET_CONTAINER_multihashmap_create (1024, GNUNET_YES);
1794 * Shut down the connections subsystem.
1799 GNUNET_CONTAINER_multihashmap_destroy (connections);
1803 struct MeshConnection *
1804 GMC_new (const struct GNUNET_HashCode *cid,
1805 struct MeshTunnel3 *t,
1806 struct MeshPeerPath *p,
1807 unsigned int own_pos)
1809 struct MeshConnection *c;
1811 c = GNUNET_new (struct MeshConnection);
1813 GNUNET_CONTAINER_multihashmap_put (connections, &c->id, c,
1814 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST);
1815 fc_init (&c->fwd_fc);
1816 fc_init (&c->bck_fc);
1821 if (own_pos > p->length - 1)
1827 c->own_pos = own_pos;
1832 c->fwd_maintenance_task =
1833 GNUNET_SCHEDULER_add_delayed (refresh_connection_time,
1834 &connection_fwd_keepalive, c);
1836 register_neighbors (c);
1842 GMC_destroy (struct MeshConnection *c)
1847 if (2 == c->destroy) /* cancel queues -> GMP_queue_cancel -> q_destroy -> */
1848 return; /* -> message_sent -> GMC_destroy. Don't loop. */
1851 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying connection %s\n", GMC_2s (c));
1853 /* Cancel all traffic */
1854 connection_cancel_queues (c, GNUNET_YES);
1855 connection_cancel_queues (c, GNUNET_NO);
1857 /* Cancel maintainance task (keepalive/timeout) */
1858 if (GNUNET_SCHEDULER_NO_TASK != c->fwd_maintenance_task)
1859 GNUNET_SCHEDULER_cancel (c->fwd_maintenance_task);
1860 if (GNUNET_SCHEDULER_NO_TASK != c->bck_maintenance_task)
1861 GNUNET_SCHEDULER_cancel (c->bck_maintenance_task);
1863 /* Unregister from neighbors */
1864 unregister_neighbors (c);
1867 GNUNET_STATISTICS_update (stats, "# connections", -1, GNUNET_NO);
1869 GMT_remove_connection (c->t, c);
1871 if (GNUNET_NO == GMC_is_origin (c, GNUNET_YES))
1872 path_destroy (c->path);
1878 * Get the connection ID.
1880 * @param c Connection to get the ID from.
1882 * @return ID of the connection.
1884 const struct GNUNET_HashCode *
1885 GMC_get_id (const struct MeshConnection *c)
1892 * Get the connection path.
1894 * @param c Connection to get the path from.
1896 * @return path used by the connection.
1898 const struct MeshPeerPath *
1899 GMC_get_path (const struct MeshConnection *c)
1906 * Get the connection state.
1908 * @param c Connection to get the state from.
1910 * @return state of the connection.
1912 enum MeshConnectionState
1913 GMC_get_state (const struct MeshConnection *c)
1919 * Get the connection tunnel.
1921 * @param c Connection to get the tunnel from.
1923 * @return tunnel of the connection.
1925 struct MeshTunnel3 *
1926 GMC_get_tunnel (const struct MeshConnection *c)
1933 * Get free buffer space in a connection.
1935 * @param c Connection.
1936 * @param fwd Is query about FWD traffic?
1938 * @return Free buffer space [0 - max_msgs_queue/max_connections]
1941 GMC_get_buffer (struct MeshConnection *c, int fwd)
1943 struct MeshFlowControl *fc;
1945 fc = fwd ? &c->fwd_fc : &c->bck_fc;
1947 return (fc->queue_max - fc->queue_n);
1951 * Get how many messages have we allowed to send to us from a direction.
1953 * @param c Connection.
1954 * @param fwd Are we asking about traffic from FWD (BCK messages)?
1956 * @return last_ack_sent - last_pid_recv
1959 GMC_get_allowed (struct MeshConnection *c, int fwd)
1961 struct MeshFlowControl *fc;
1963 fc = fwd ? &c->fwd_fc : &c->bck_fc;
1964 if (GMC_is_pid_bigger(fc->last_pid_recv, fc->last_ack_sent))
1968 return (fc->last_ack_sent - fc->last_pid_recv);
1972 * Get messages queued in a connection.
1974 * @param c Connection.
1975 * @param fwd Is query about FWD traffic?
1977 * @return Number of messages queued.
1980 GMC_get_qn (struct MeshConnection *c, int fwd)
1982 struct MeshFlowControl *fc;
1984 fc = fwd ? &c->fwd_fc : &c->bck_fc;
1991 * Allow the connection to advertise a buffer of the given size.
1993 * The connection will send an @c fwd ACK message (so: in direction !fwd)
1994 * allowing up to last_pid_recv + buffer.
1996 * @param c Connection.
1997 * @param buffer How many more messages the connection can accept.
1998 * @param fwd Is this about FWD traffic? (The ack will go dest->root).
2001 GMC_allow (struct MeshConnection *c, unsigned int buffer, int fwd)
2003 send_ack (c, buffer, fwd);
2008 * Notify other peers on a connection of a broken link. Mark connections
2009 * to destroy after all traffic has been sent.
2011 * @param c Connection on which there has been a disconnection.
2012 * @param peer Peer that disconnected.
2015 GMC_notify_broken (struct MeshConnection *c,
2016 struct MeshPeer *peer)
2020 fwd = peer == get_prev_hop (c);
2022 if (GNUNET_YES == GMC_is_terminal (c, fwd))
2024 /* Local shutdown, no one to notify about this. */
2028 if (GNUNET_NO == c->destroy)
2029 send_broken (c, &my_full_id, GMP_get_id (peer), fwd);
2031 /* Connection will have at least one pending message
2032 * (the one we just scheduled), so no point in checking whether to
2033 * destroy immediately. */
2034 c->destroy = GNUNET_YES;
2037 * Cancel all queues, if no message is left, connection will be destroyed.
2039 connection_cancel_queues (c, !fwd);
2046 * Is this peer the first one on the connection?
2048 * @param c Connection.
2049 * @param fwd Is this about fwd traffic?
2051 * @return GNUNET_YES if origin, GNUNET_NO if relay/terminal.
2054 GMC_is_origin (struct MeshConnection *c, int fwd)
2056 if (!fwd && c->path->length - 1 == c->own_pos )
2058 if (fwd && 0 == c->own_pos)
2065 * Is this peer the last one on the connection?
2067 * @param c Connection.
2068 * @param fwd Is this about fwd traffic?
2069 * Note that the ROOT is the terminal for BCK traffic!
2071 * @return GNUNET_YES if terminal, GNUNET_NO if relay/origin.
2074 GMC_is_terminal (struct MeshConnection *c, int fwd)
2076 return GMC_is_origin (c, !fwd);
2081 * See if we are allowed to send by the next hop in the given direction.
2083 * @param c Connection.
2084 * @param fwd Is this about fwd traffic?
2086 * @return GNUNET_YES in case it's OK.
2089 GMC_is_sendable (struct MeshConnection *c, int fwd)
2091 struct MeshFlowControl *fc;
2093 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2094 if (GMC_is_pid_bigger (fc->last_ack_recv, fc->last_pid_sent))
2100 * Sends an already built message on a connection, properly registering
2101 * all used resources.
2103 * @param message Message to send. Function makes a copy of it.
2104 * If message is not hop-by-hop, decrements TTL of copy.
2105 * @param c Connection on which this message is transmitted.
2106 * @param fwd Is this a fwd message?
2109 GMC_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2110 struct MeshConnection *c,
2113 struct MeshFlowControl *fc;
2119 size = ntohs (message->size);
2120 data = GNUNET_malloc (size);
2121 memcpy (data, message, size);
2122 type = ntohs (message->type);
2123 LOG (GNUNET_ERROR_TYPE_DEBUG, "Send %s (%u) on connection %s\n",
2124 GNUNET_MESH_DEBUG_M2S (type), size, GMC_2s (c));
2126 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2127 droppable = GNUNET_YES;
2130 struct GNUNET_MESH_Encrypted *emsg;
2131 struct GNUNET_MESH_ACK *amsg;
2132 struct GNUNET_MESH_Poll *pmsg;
2133 struct GNUNET_MESH_ConnectionDestroy *dmsg;
2134 struct GNUNET_MESH_ConnectionBroken *bmsg;
2137 case GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED:
2138 emsg = (struct GNUNET_MESH_Encrypted *) data;
2139 ttl = ntohl (emsg->ttl);
2142 GNUNET_break_op (0);
2146 emsg->ttl = htonl (ttl - 1);
2147 emsg->pid = htonl (fwd ? c->fwd_fc.next_pid++ : c->bck_fc.next_pid++);
2148 LOG (GNUNET_ERROR_TYPE_DEBUG, " Q_N+ %p %u\n", fc, fc->queue_n);
2150 LOG (GNUNET_ERROR_TYPE_DEBUG, "pid %u\n", ntohl (emsg->pid));
2151 LOG (GNUNET_ERROR_TYPE_DEBUG, "last pid %u\n", fc->last_pid_sent);
2152 LOG (GNUNET_ERROR_TYPE_DEBUG, " ack %u\n", fc->last_ack_recv);
2153 if (GMC_is_pid_bigger (fc->last_pid_sent + 1, fc->last_ack_recv))
2155 GMC_start_poll (c, fwd);
2159 case GNUNET_MESSAGE_TYPE_MESH_ACK:
2160 amsg = (struct GNUNET_MESH_ACK *) data;
2162 LOG (GNUNET_ERROR_TYPE_DEBUG, " ack %u\n", ntohl (amsg->ack));
2163 droppable = GNUNET_NO;
2166 case GNUNET_MESSAGE_TYPE_MESH_POLL:
2167 pmsg = (struct GNUNET_MESH_Poll *) data;
2169 pmsg->pid = htonl (fwd ? c->fwd_fc.last_pid_sent : c->bck_fc.last_pid_sent);
2170 LOG (GNUNET_ERROR_TYPE_DEBUG, " poll %u\n", ntohl (pmsg->pid));
2171 droppable = GNUNET_NO;
2174 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_DESTROY:
2175 dmsg = (struct GNUNET_MESH_ConnectionDestroy *) data;
2180 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_BROKEN:
2181 bmsg = (struct GNUNET_MESH_ConnectionBroken *) data;
2186 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_CREATE:
2187 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_ACK:
2194 if (fc->queue_n > fc->queue_max && droppable)
2196 GNUNET_STATISTICS_update (stats, "# messages dropped (buffer full)",
2199 LOG (GNUNET_ERROR_TYPE_DEBUG,
2200 "queue full: %u/%u\n",
2201 fc->queue_n, fc->queue_max);
2202 if (GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED == type)
2204 return; /* Drop this message */
2207 c->pending_messages++;
2209 GMP_queue_add (get_hop (c, fwd), data, type, size, c, fwd,
2210 &message_sent, NULL);
2215 * Sends a CREATE CONNECTION message for a path to a peer.
2216 * Changes the connection and tunnel states if necessary.
2218 * @param connection Connection to create.
2221 GMC_send_create (struct MeshConnection *connection)
2223 enum MeshTunnel3State state;
2226 size = sizeof (struct GNUNET_MESH_ConnectionCreate);
2227 size += connection->path->length * sizeof (struct GNUNET_PeerIdentity);
2228 LOG (GNUNET_ERROR_TYPE_DEBUG, "Send connection create\n");
2229 GMP_queue_add (get_next_hop (connection), NULL,
2230 GNUNET_MESSAGE_TYPE_MESH_CONNECTION_CREATE,
2231 size, connection, GNUNET_YES, &message_sent, NULL);
2232 state = GMT_get_state (connection->t);
2233 if (MESH_TUNNEL3_SEARCHING == state || MESH_TUNNEL3_NEW == state)
2234 GMT_change_state (connection->t, MESH_TUNNEL3_WAITING);
2235 if (MESH_CONNECTION_NEW == connection->state)
2236 connection_change_state (connection, MESH_CONNECTION_SENT);
2241 * Send a message to all peers in this connection that the connection
2242 * is no longer valid.
2244 * If some peer should not receive the message, it should be zero'ed out
2245 * before calling this function.
2247 * @param c The connection whose peers to notify.
2250 GMC_send_destroy (struct MeshConnection *c)
2252 struct GNUNET_MESH_ConnectionDestroy msg;
2254 if (GNUNET_YES == c->destroy)
2257 msg.header.size = htons (sizeof (msg));
2258 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CONNECTION_DESTROY);;
2260 LOG (GNUNET_ERROR_TYPE_DEBUG,
2261 " sending connection destroy for connection %s\n",
2264 if (GNUNET_NO == GMC_is_terminal (c, GNUNET_YES))
2265 GMC_send_prebuilt_message (&msg.header, c, GNUNET_YES);
2266 if (GNUNET_NO == GMC_is_terminal (c, GNUNET_NO))
2267 GMC_send_prebuilt_message (&msg.header, c, GNUNET_NO);
2268 c->destroy = GNUNET_YES;
2273 * @brief Start a polling timer for the connection.
2275 * When a neighbor does not accept more traffic on the connection it could be
2276 * caused by a simple congestion or by a lost ACK. Polling enables to check
2277 * for the lastest ACK status for a connection.
2279 * @param c Connection.
2280 * @param fwd Should we poll in the FWD direction?
2283 GMC_start_poll (struct MeshConnection *c, int fwd)
2285 struct MeshFlowControl *fc;
2287 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2288 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task)
2292 fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time,
2299 * @brief Stop polling a connection for ACKs.
2301 * Once we have enough ACKs for future traffic, polls are no longer necessary.
2303 * @param c Connection.
2304 * @param fwd Should we stop the poll in the FWD direction?
2307 GMC_stop_poll (struct MeshConnection *c, int fwd)
2309 struct MeshFlowControl *fc;
2311 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2312 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task)
2314 GNUNET_SCHEDULER_cancel (fc->poll_task);
2315 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
2320 * Get a (static) string for a connection.
2322 * @param c Connection.
2325 GMC_2s (struct MeshConnection *c)
2329 static char buf[128];
2331 sprintf (buf, "%s (->%s)", GNUNET_h2s (&c->id), GMT_2s (c->t));
2334 return GNUNET_h2s (&c->id);