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_MeshHash id;
177 * State of the connection.
179 enum MeshConnectionState state;
182 * Path being used for the tunnel. At the origin of the connection
183 * it's a pointer to the destination's path pool, otherwise just a copy.
185 struct MeshPeerPath *path;
188 * Position of the local peer in the path.
190 unsigned int own_pos;
193 * Task to keep the used paths alive at the owner,
194 * time tunnel out on all the other peers.
196 GNUNET_SCHEDULER_TaskIdentifier fwd_maintenance_task;
199 * Task to keep the used paths alive at the destination,
200 * time tunnel out on all the other peers.
202 GNUNET_SCHEDULER_TaskIdentifier bck_maintenance_task;
205 * Queue handle for maintainance traffic. One handle for FWD and BCK since
206 * one peer never needs to maintain both directions (no loopback connections).
208 struct MeshPeerQueue *maintenance_q;
211 * Counter to do exponential backoff when creating a connection (max 64).
213 unsigned short create_retry;
216 * Pending message count.
218 int pending_messages;
221 * Destroy flag: if true, destroy on last message.
227 * Handle for messages queued but not yet sent.
229 struct MeshConnectionQueue
232 * Peer queue handle, to cancel if necessary.
234 struct MeshPeerQueue *q;
237 * Was this a forced message? (Do not account for it)
242 * Continuation to call once sent.
247 * Closure for @c cont.
252 /******************************************************************************/
253 /******************************* GLOBALS ***********************************/
254 /******************************************************************************/
257 * Global handle to the statistics service.
259 extern struct GNUNET_STATISTICS_Handle *stats;
262 * Local peer own ID (memory efficient handle).
264 extern GNUNET_PEER_Id myid;
267 * Local peer own ID (full value).
269 extern struct GNUNET_PeerIdentity my_full_id;
272 * Connections known, indexed by cid (MeshConnection).
274 static struct GNUNET_CONTAINER_MultiHashMap *connections;
277 * How many connections are we willing to maintain.
278 * Local connections are always allowed, even if there are more connections than max.
280 static unsigned long long max_connections;
283 * How many messages *in total* are we willing to queue, divide by number of
284 * connections to get connection queue size.
286 static unsigned long long max_msgs_queue;
289 * How often to send path keepalives. Paths timeout after 4 missed.
291 static struct GNUNET_TIME_Relative refresh_connection_time;
294 * How often to send path create / ACKs.
296 static struct GNUNET_TIME_Relative create_connection_time;
299 /******************************************************************************/
300 /******************************** STATIC ***********************************/
301 /******************************************************************************/
303 #if 0 // avoid compiler warning for unused static function
305 fc_debug (struct MeshFlowControl *fc)
307 LOG (GNUNET_ERROR_TYPE_DEBUG, " IN: %u/%u\n",
308 fc->last_pid_recv, fc->last_ack_sent);
309 LOG (GNUNET_ERROR_TYPE_DEBUG, " OUT: %u/%u\n",
310 fc->last_pid_sent, fc->last_ack_recv);
311 LOG (GNUNET_ERROR_TYPE_DEBUG, " QUEUE: %u/%u\n",
312 fc->queue_n, fc->queue_max);
316 connection_debug (struct MeshConnection *c)
320 LOG (GNUNET_ERROR_TYPE_DEBUG, "*** DEBUG NULL CONNECTION ***\n");
323 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s:%X\n",
324 peer2s (c->t->peer), GMC_2s (c));
325 LOG (GNUNET_ERROR_TYPE_DEBUG, " state: %u, pending msgs: %u\n",
326 c->state, c->pending_messages);
327 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD FC\n");
328 fc_debug (&c->fwd_fc);
329 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK FC\n");
330 fc_debug (&c->bck_fc);
336 * Schedule next keepalive task, taking in consideration
337 * the connection state and number of retries.
339 * @param c Connection for which to schedule the next keepalive.
340 * @param fwd Direction for the next keepalive.
343 schedule_next_keepalive (struct MeshConnection *c, int fwd);
347 * Resets the connection timeout task, some other message has done the
349 * - For the first peer on the direction this means to send
350 * a keepalive or a path confirmation message (either create or ACK).
351 * - For all other peers, this means to destroy the connection,
352 * due to lack of activity.
353 * Starts the timeout if no timeout was running (connection just created).
355 * @param c Connection whose timeout to reset.
356 * @param fwd Is this forward?
359 connection_reset_timeout (struct MeshConnection *c, int fwd);
363 * Get string description for tunnel state. Reentrant.
365 * @param s Tunnel state.
367 * @return String representation.
370 GMC_state2s (enum MeshConnectionState s)
374 case MESH_CONNECTION_NEW:
375 return "MESH_CONNECTION_NEW";
376 case MESH_CONNECTION_SENT:
377 return "MESH_CONNECTION_SENT";
378 case MESH_CONNECTION_ACK:
379 return "MESH_CONNECTION_ACK";
380 case MESH_CONNECTION_READY:
381 return "MESH_CONNECTION_READY";
382 case MESH_CONNECTION_DESTROYED:
383 return "MESH_CONNECTION_DESTROYED";
385 return "MESH_CONNECTION_STATE_ERROR";
391 * Initialize a Flow Control structure to the initial state.
393 * @param fc Flow Control structure to initialize.
396 fc_init (struct MeshFlowControl *fc)
399 fc->last_pid_sent = (uint32_t) -1; /* Next (expected) = 0 */
400 fc->last_pid_recv = (uint32_t) -1;
401 fc->last_ack_sent = (uint32_t) 0;
402 fc->last_ack_recv = (uint32_t) 0;
403 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
404 fc->poll_time = GNUNET_TIME_UNIT_SECONDS;
406 fc->queue_max = (max_msgs_queue / max_connections) + 1;
413 * @param cid Connection ID.
415 static struct MeshConnection *
416 connection_get (const struct GNUNET_MeshHash *cid)
418 return GNUNET_CONTAINER_multihashmap_get (connections, GM_h2hc (cid));
423 connection_change_state (struct MeshConnection* c,
424 enum MeshConnectionState state)
426 LOG (GNUNET_ERROR_TYPE_DEBUG,
427 "Connection %s state %s -> %s\n",
428 GMC_2s (c), GMC_state2s (c->state), GMC_state2s (state));
429 if (MESH_CONNECTION_DESTROYED == c->state)
431 LOG (GNUNET_ERROR_TYPE_DEBUG, "state not changing anymore\n");
435 if (MESH_CONNECTION_READY == state)
441 * Callback called when a queued ACK message is sent.
443 * @param cls Closure (FC).
444 * @param c Connection this message was on.
445 * @param q Queue handler this call invalidates.
446 * @param type Type of message sent.
447 * @param fwd Was this a FWD going message?
448 * @param size Size of the message.
452 struct MeshConnection *c,
453 struct MeshConnectionQueue *q,
454 uint16_t type, int fwd, size_t size)
456 struct MeshFlowControl *fc = cls;
463 * Send an ACK on the connection, informing the predecessor about
464 * the available buffer space. Should not be called in case the peer
465 * is origin (no predecessor) in the @c fwd direction.
467 * Note that for fwd ack, the FWD mean forward *traffic* (root->dest),
468 * the ACK itself goes "back" (dest->root).
470 * @param c Connection on which to send the ACK.
471 * @param buffer How much space free to advertise?
472 * @param fwd Is this FWD ACK? (Going dest -> root)
473 * @param force Don't optimize out.
476 send_ack (struct MeshConnection *c, unsigned int buffer, int fwd, int force)
478 struct MeshFlowControl *next_fc;
479 struct MeshFlowControl *prev_fc;
480 struct GNUNET_MESH_ACK msg;
484 /* If origin, there is no connection to send ACKs. Wrong function! */
485 if (GMC_is_origin (c, fwd))
487 LOG (GNUNET_ERROR_TYPE_DEBUG, "connection %s is origin in %s\n",
488 GMC_2s (c), GM_f2s (fwd));
493 next_fc = fwd ? &c->fwd_fc : &c->bck_fc;
494 prev_fc = fwd ? &c->bck_fc : &c->fwd_fc;
496 LOG (GNUNET_ERROR_TYPE_DEBUG, "connection send %s ack on %s\n",
497 GM_f2s (fwd), GMC_2s (c));
499 /* Check if we need to transmit the ACK. */
500 delta = prev_fc->last_ack_sent - prev_fc->last_pid_recv;
501 if (3 < delta && buffer < delta && GNUNET_NO == force)
503 LOG (GNUNET_ERROR_TYPE_DEBUG, "Not sending ACK, buffer > 3\n");
504 LOG (GNUNET_ERROR_TYPE_DEBUG,
505 " last pid recv: %u, last ack sent: %u\n",
506 prev_fc->last_pid_recv, prev_fc->last_ack_sent);
510 /* Ok, ACK might be necessary, what PID to ACK? */
511 ack = prev_fc->last_pid_recv + buffer;
512 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK %u\n", ack);
513 LOG (GNUNET_ERROR_TYPE_DEBUG,
514 " last pid %u, last ack %u, qmax %u, q %u\n",
515 prev_fc->last_pid_recv, prev_fc->last_ack_sent,
516 next_fc->queue_max, next_fc->queue_n);
517 if (ack == prev_fc->last_ack_sent && GNUNET_NO == force)
519 LOG (GNUNET_ERROR_TYPE_DEBUG, "Not sending FWD ACK, not needed\n");
523 /* Check if message is already in queue */
524 if (NULL != prev_fc->ack_msg)
526 if (GM_is_pid_bigger (ack, prev_fc->last_ack_sent))
528 LOG (GNUNET_ERROR_TYPE_DEBUG, " canceling old ACK\n");
529 GMC_cancel (prev_fc->ack_msg);
530 /* GMC_cancel triggers ack_sent(), which clears fc->ack_msg */
534 LOG (GNUNET_ERROR_TYPE_DEBUG, " same ACK already in queue\n");
539 prev_fc->last_ack_sent = ack;
541 /* Build ACK message and send on connection */
542 msg.header.size = htons (sizeof (msg));
543 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_ACK);
544 msg.ack = htonl (ack);
547 prev_fc->ack_msg = GMC_send_prebuilt_message (&msg.header, c,
554 * Callback called when a queued message is sent.
556 * Calculates the average time and connection packet tracking.
558 * @param cls Closure (ConnectionQueue Handle).
559 * @param c Connection this message was on.
560 * @param type Type of message sent.
561 * @param fwd Was this a FWD going message?
562 * @param size Size of the message.
563 * @param wait Time spent waiting for core (only the time for THIS message)
566 message_sent (void *cls,
567 struct MeshConnection *c, uint16_t type,
568 int fwd, size_t size,
569 struct GNUNET_TIME_Relative wait)
571 struct MeshConnectionPerformance *p;
572 struct MeshFlowControl *fc;
573 struct MeshConnectionQueue *q = cls;
577 fc = fwd ? &c->fwd_fc : &c->bck_fc;
578 LOG (GNUNET_ERROR_TYPE_DEBUG,
582 LOG (GNUNET_ERROR_TYPE_DEBUG, "! C_P- %p %u\n", c, c->pending_messages);
588 LOG (GNUNET_ERROR_TYPE_DEBUG, "! calling cont\n");
589 q->cont (q->cont_cls, c, q, type, fwd, size);
593 else if (type == GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED)
595 /* If NULL == q and ENCRYPTED == type, message must have been ch_mngmnt */
602 c->pending_messages--;
603 if (GNUNET_YES == c->destroy && 0 == c->pending_messages)
605 LOG (GNUNET_ERROR_TYPE_DEBUG, "! destroying connection!\n");
609 /* Send ACK if needed, after accounting for sent ID in fc->queue_n */
612 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_CREATE:
613 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_ACK:
614 c->maintenance_q = NULL;
615 /* Don't trigger a keepalive for sent ACKs, only SYN and SYNACKs */
616 if (GNUNET_MESSAGE_TYPE_MESH_CONNECTION_CREATE == type || !fwd)
617 schedule_next_keepalive (c, fwd);
620 case GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED:
622 LOG (GNUNET_ERROR_TYPE_DEBUG, "! Q_N- %p %u\n", fc, fc->queue_n);
623 if (GNUNET_NO == forced)
626 LOG (GNUNET_ERROR_TYPE_DEBUG,
627 "! accounting pid %u\n",
632 LOG (GNUNET_ERROR_TYPE_DEBUG,
633 "! forced, Q_N not accounting pid %u\n",
636 GMC_send_ack (c, fwd, GNUNET_NO);
637 connection_reset_timeout (c, fwd);
640 case GNUNET_MESSAGE_TYPE_MESH_POLL:
644 case GNUNET_MESSAGE_TYPE_MESH_ACK:
651 LOG (GNUNET_ERROR_TYPE_DEBUG, "! message sent!\n");
654 return; /* Only endpoints are interested in timing. */
657 usecsperbyte = ((double) wait.rel_value_us) / size;
658 if (p->size == AVG_MSGS)
660 /* Array is full. Substract oldest value, add new one and store. */
661 p->avg -= (p->usecsperbyte[p->idx] / AVG_MSGS);
662 p->usecsperbyte[p->idx] = usecsperbyte;
663 p->avg += (p->usecsperbyte[p->idx] / AVG_MSGS);
667 /* Array not yet full. Add current value to avg and store. */
668 p->usecsperbyte[p->idx] = usecsperbyte;
670 p->avg += p->usecsperbyte[p->idx];
674 p->idx = (p->idx + 1) % AVG_MSGS;
679 * Get the previous hop in a connection
681 * @param c Connection.
683 * @return Previous peer in the connection.
685 static struct MeshPeer *
686 get_prev_hop (const struct MeshConnection *c)
690 LOG (GNUNET_ERROR_TYPE_DEBUG, " get prev hop %s [%u/%u]\n",
691 GMC_2s (c), c->own_pos, c->path->length);
692 if (0 == c->own_pos || c->path->length < 2)
693 id = c->path->peers[0];
695 id = c->path->peers[c->own_pos - 1];
697 LOG (GNUNET_ERROR_TYPE_DEBUG, " ID: %s (%u)\n",
698 GNUNET_i2s (GNUNET_PEER_resolve2 (id)), id);
700 return GMP_get_short (id);
705 * Get the next hop in a connection
707 * @param c Connection.
709 * @return Next peer in the connection.
711 static struct MeshPeer *
712 get_next_hop (const struct MeshConnection *c)
716 LOG (GNUNET_ERROR_TYPE_DEBUG, " get next hop %s [%u/%u]\n",
717 GMC_2s (c), c->own_pos, c->path->length);
718 if ((c->path->length - 1) == c->own_pos || c->path->length < 2)
719 id = c->path->peers[c->path->length - 1];
721 id = c->path->peers[c->own_pos + 1];
723 LOG (GNUNET_ERROR_TYPE_DEBUG, " ID: %s (%u)\n",
724 GNUNET_i2s (GNUNET_PEER_resolve2 (id)), id);
726 return GMP_get_short (id);
731 * Get the hop in a connection.
733 * @param c Connection.
734 * @param fwd Next hop?
736 * @return Next peer in the connection.
738 static struct MeshPeer *
739 get_hop (struct MeshConnection *c, int fwd)
742 return get_next_hop (c);
743 return get_prev_hop (c);
748 * Is traffic coming from this sender 'FWD' traffic?
750 * @param c Connection to check.
751 * @param sender Peer identity of neighbor.
753 * @return #GNUNET_YES in case the sender is the 'prev' hop and therefore
754 * the traffic is 'FWD'.
755 * #GNUNET_NO for BCK.
756 * #GNUNET_SYSERR for errors.
759 is_fwd (const struct MeshConnection *c,
760 const struct GNUNET_PeerIdentity *sender)
764 id = GNUNET_PEER_search (sender);
765 if (GMP_get_short_id (get_prev_hop (c)) == id)
768 if (GMP_get_short_id (get_next_hop (c)) == id)
772 return GNUNET_SYSERR;
777 * Sends a CONNECTION ACK message in reponse to a received CONNECTION_CREATE
778 * or a first CONNECTION_ACK directed to us.
780 * @param connection Connection to confirm.
781 * @param fwd Should we send it FWD? (root->dest)
782 * (First (~SYNACK) goes BCK, second (~ACK) goes FWD)
785 send_connection_ack (struct MeshConnection *connection, int fwd)
787 struct MeshTunnel3 *t;
790 LOG (GNUNET_ERROR_TYPE_INFO, "=> {%18s ACK} on connection %s\n",
791 GM_f2s (!fwd), GMC_2s (connection));
792 GMP_queue_add (get_hop (connection, fwd), NULL,
793 GNUNET_MESSAGE_TYPE_MESH_CONNECTION_ACK,
794 sizeof (struct GNUNET_MESH_ConnectionACK),
795 connection, fwd, &message_sent, NULL);
796 connection->pending_messages++;
797 if (MESH_TUNNEL3_NEW == GMT_get_cstate (t))
798 GMT_change_cstate (t, MESH_TUNNEL3_WAITING);
799 if (MESH_CONNECTION_READY != connection->state)
800 connection_change_state (connection, MESH_CONNECTION_SENT);
805 * Send a notification that a connection is broken.
807 * @param c Connection that is broken.
808 * @param id1 Peer that has disconnected.
809 * @param id2 Peer that has disconnected.
810 * @param fwd Direction towards which to send it.
813 send_broken (struct MeshConnection *c,
814 const struct GNUNET_PeerIdentity *id1,
815 const struct GNUNET_PeerIdentity *id2,
818 struct GNUNET_MESH_ConnectionBroken msg;
820 msg.header.size = htons (sizeof (struct GNUNET_MESH_ConnectionBroken));
821 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CONNECTION_BROKEN);
825 GMC_send_prebuilt_message (&msg.header, c, fwd, GNUNET_YES, NULL, NULL);
830 * Send a notification that a connection is broken, when a connection
831 * isn't even created.
833 * @param connection_id Connection ID.
834 * @param id1 Peer that has disconnected.
835 * @param id2 Peer that has disconnected.
836 * @param peer Peer to notify (neighbor who sent the connection).
839 send_broken2 (struct GNUNET_MeshHash *connection_id,
840 const struct GNUNET_PeerIdentity *id1,
841 const struct GNUNET_PeerIdentity *id2,
842 GNUNET_PEER_Id peer_id)
844 struct GNUNET_MESH_ConnectionBroken *msg;
845 struct MeshPeer *neighbor;
847 LOG (GNUNET_ERROR_TYPE_INFO, "=> BROKEN on unknown connection %s\n",
848 GNUNET_h2s (GM_h2hc (connection_id)));
850 msg = GNUNET_new (struct GNUNET_MESH_ConnectionBroken);
851 msg->header.size = htons (sizeof (struct GNUNET_MESH_ConnectionBroken));
852 msg->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CONNECTION_BROKEN);
853 msg->cid = *connection_id;
856 neighbor = GMP_get_short (peer_id);
857 GMP_queue_add (neighbor, msg,
858 GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED,
859 sizeof (struct GNUNET_MESH_ConnectionBroken),
860 NULL, GNUNET_SYSERR, /* connection, fwd */
861 NULL, NULL); /* continuation */
866 * Send keepalive packets for a connection.
868 * @param c Connection to keep alive..
869 * @param fwd Is this a FWD keepalive? (owner -> dest).
872 send_connection_keepalive (struct MeshConnection *c, int fwd)
874 struct GNUNET_MessageHeader msg;
876 LOG (GNUNET_ERROR_TYPE_INFO,
877 "keepalive %s for connection %s\n",
878 GM_f2s (fwd), GMC_2s (c));
879 GNUNET_STATISTICS_update (stats, "# keepalives sent", 1, GNUNET_NO);
881 GNUNET_assert (NULL != c->t);
882 msg.size = htons (sizeof (msg));
883 msg.type = htons (GNUNET_MESSAGE_TYPE_MESH_KEEPALIVE);
885 GNUNET_assert (NULL ==
886 GMT_send_prebuilt_message (&msg, c->t, c,
887 GNUNET_NO, NULL, NULL));
892 * Send CONNECTION_{CREATE/ACK} packets for a connection.
894 * @param c Connection for which to send the message.
895 * @param fwd If #GNUNET_YES, send CREATE, otherwise send ACK.
898 connection_recreate (struct MeshConnection *c, int fwd)
900 LOG (GNUNET_ERROR_TYPE_DEBUG, "sending connection recreate\n");
904 send_connection_ack (c, GNUNET_NO);
909 * Generic connection timer management.
910 * Depending on the role of the peer in the connection will send the
911 * appropriate message (build or keepalive)
913 * @param c Conncetion to maintain.
917 connection_maintain (struct MeshConnection *c, int fwd)
919 if (GNUNET_NO != c->destroy)
922 if (MESH_TUNNEL3_SEARCHING == GMT_get_cstate (c->t))
924 /* TODO DHT GET with RO_BART */
929 case MESH_CONNECTION_NEW:
932 case MESH_CONNECTION_SENT:
933 connection_recreate (c, fwd);
935 case MESH_CONNECTION_READY:
936 send_connection_keepalive (c, fwd);
946 * Keep the connection alive.
948 * @param c Connection to keep alive.
949 * @param fwd Direction.
950 * @param shutdown Are we shutting down? (Don't send traffic)
951 * Non-zero value for true, not necessarily GNUNET_YES.
954 connection_keepalive (struct MeshConnection *c, int fwd, int shutdown)
956 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s keepalive for %s\n",
957 GM_f2s (fwd), GMC_2s (c));
960 c->fwd_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
962 c->bck_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
964 if (GNUNET_NO != shutdown)
967 connection_maintain (c, fwd);
969 /* Next execution will be scheduled by message_sent */
974 * Keep the connection alive in the FWD direction.
976 * @param cls Closure (connection to keepalive).
977 * @param tc TaskContext.
980 connection_fwd_keepalive (void *cls,
981 const struct GNUNET_SCHEDULER_TaskContext *tc)
983 connection_keepalive ((struct MeshConnection *) cls,
985 tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN);
990 * Keep the connection alive in the BCK direction.
992 * @param cls Closure (connection to keepalive).
993 * @param tc TaskContext.
996 connection_bck_keepalive (void *cls,
997 const struct GNUNET_SCHEDULER_TaskContext *tc)
999 connection_keepalive ((struct MeshConnection *) cls,
1001 tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN);
1006 * Schedule next keepalive task, taking in consideration
1007 * the connection state and number of retries.
1009 * If the peer is not the origin, do nothing.
1011 * @param c Connection for which to schedule the next keepalive.
1012 * @param fwd Direction for the next keepalive.
1015 schedule_next_keepalive (struct MeshConnection *c, int fwd)
1017 struct GNUNET_TIME_Relative delay;
1018 GNUNET_SCHEDULER_TaskIdentifier *task_id;
1019 GNUNET_SCHEDULER_Task keepalive_task;
1021 if (GNUNET_NO == GMC_is_origin (c, fwd))
1024 /* Calculate delay to use, depending on the state of the connection */
1025 if (MESH_CONNECTION_READY == c->state)
1027 delay = refresh_connection_time;
1031 if (1 > c->create_retry)
1032 c->create_retry = 1;
1033 delay = GNUNET_TIME_relative_multiply (create_connection_time,
1035 if (c->create_retry < 64)
1036 c->create_retry *= 2;
1039 /* Select direction-dependent parameters */
1040 if (GNUNET_YES == fwd)
1042 task_id = &c->fwd_maintenance_task;
1043 keepalive_task = &connection_fwd_keepalive;
1047 task_id = &c->bck_maintenance_task;
1048 keepalive_task = &connection_bck_keepalive;
1051 /* Check that no one scheduled it before us */
1052 if (GNUNET_SCHEDULER_NO_TASK != *task_id)
1054 /* No need for a _break. It can happen for instance when sending a SYNACK
1055 * for a duplicate SYN: the first SYNACK scheduled the task. */
1056 GNUNET_SCHEDULER_cancel (*task_id);
1059 /* Schedule the task */
1060 *task_id = GNUNET_SCHEDULER_add_delayed (delay, keepalive_task, c);
1061 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "next keepalive in %s\n",
1062 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
1067 * @brief Re-initiate traffic on this connection if necessary.
1069 * Check if there is traffic queued towards this peer
1070 * and the core transmit handle is NULL (traffic was stalled).
1071 * If so, call core tmt rdy.
1073 * @param c Connection on which initiate traffic.
1074 * @param fwd Is this about fwd traffic?
1077 connection_unlock_queue (struct MeshConnection *c, int fwd)
1079 struct MeshPeer *peer;
1081 LOG (GNUNET_ERROR_TYPE_DEBUG,
1082 "connection_unlock_queue %s on %s\n",
1083 GM_f2s (fwd), GMC_2s (c));
1085 if (GMC_is_terminal (c, fwd))
1087 LOG (GNUNET_ERROR_TYPE_DEBUG, " is terminal!\n");
1091 peer = get_hop (c, fwd);
1092 GMP_queue_unlock (peer, c);
1097 * Cancel all transmissions that belong to a certain connection.
1099 * If the connection is scheduled for destruction and no more messages are left,
1100 * the connection will be destroyed by the continuation call.
1102 * @param c Connection which to cancel. Might be destroyed during this call.
1103 * @param fwd Cancel fwd traffic?
1106 connection_cancel_queues (struct MeshConnection *c, int fwd)
1108 struct MeshFlowControl *fc;
1109 struct MeshPeer *peer;
1111 LOG (GNUNET_ERROR_TYPE_DEBUG,
1112 " *** Cancel %s queues for connection %s\n",
1113 GM_f2s (fwd), GMC_2s (c));
1120 fc = fwd ? &c->fwd_fc : &c->bck_fc;
1121 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task)
1123 GNUNET_SCHEDULER_cancel (fc->poll_task);
1124 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
1125 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** Cancel POLL in ccq for fc %p\n", fc);
1127 peer = get_hop (c, fwd);
1128 GMP_queue_cancel (peer, c);
1133 * Function called if a connection has been stalled for a while,
1134 * possibly due to a missed ACK. Poll the neighbor about its ACK status.
1136 * @param cls Closure (poll ctx).
1137 * @param tc TaskContext.
1140 connection_poll (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
1144 * Callback called when a queued POLL message is sent.
1146 * @param cls Closure (FC).
1147 * @param c Connection this message was on.
1148 * @param q Queue handler this call invalidates.
1149 * @param type Type of message sent.
1150 * @param fwd Was this a FWD going message?
1151 * @param size Size of the message.
1154 poll_sent (void *cls,
1155 struct MeshConnection *c,
1156 struct MeshConnectionQueue *q,
1157 uint16_t type, int fwd, size_t size)
1159 struct MeshFlowControl *fc = cls;
1161 if (2 == c->destroy)
1163 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL canceled on shutdown\n");
1166 LOG (GNUNET_ERROR_TYPE_DEBUG,
1167 " *** POLL sent for , scheduling new one!\n");
1168 fc->poll_msg = NULL;
1169 fc->poll_time = GNUNET_TIME_STD_BACKOFF (fc->poll_time);
1170 fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time,
1171 &connection_poll, fc);
1172 LOG (GNUNET_ERROR_TYPE_DEBUG, " task %u\n", fc->poll_task);
1177 * Function called if a connection has been stalled for a while,
1178 * possibly due to a missed ACK. Poll the neighbor about its ACK status.
1180 * @param cls Closure (poll ctx).
1181 * @param tc TaskContext.
1184 connection_poll (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1186 struct MeshFlowControl *fc = cls;
1187 struct GNUNET_MESH_Poll msg;
1188 struct MeshConnection *c;
1190 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
1191 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1197 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** Polling!\n");
1198 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** connection [%s]\n", GMC_2s (c));
1199 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** %s\n",
1200 fc == &c->fwd_fc ? "FWD" : "BCK");
1202 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_POLL);
1203 msg.header.size = htons (sizeof (msg));
1204 msg.pid = htonl (fc->last_pid_sent);
1205 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** last pid sent: %u!\n", fc->last_pid_sent);
1206 fc->poll_msg = GMC_send_prebuilt_message (&msg.header, c,
1207 fc == &c->fwd_fc, GNUNET_YES,
1213 * Timeout function due to lack of keepalive/traffic from the owner.
1214 * Destroys connection if called.
1216 * @param cls Closure (connection to destroy).
1217 * @param tc TaskContext.
1220 connection_fwd_timeout (void *cls,
1221 const struct GNUNET_SCHEDULER_TaskContext *tc)
1223 struct MeshConnection *c = cls;
1225 c->fwd_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
1226 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1229 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s FWD timed out. Destroying.\n",
1231 if (GMC_is_origin (c, GNUNET_YES)) /* If local, leave. */
1242 * Timeout function due to lack of keepalive/traffic from the destination.
1243 * Destroys connection if called.
1245 * @param cls Closure (connection to destroy).
1246 * @param tc TaskContext
1249 connection_bck_timeout (void *cls,
1250 const struct GNUNET_SCHEDULER_TaskContext *tc)
1252 struct MeshConnection *c = cls;
1254 c->bck_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
1255 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1258 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s BCK timed out. Destroying.\n",
1261 if (GMC_is_origin (c, GNUNET_NO)) /* If local, leave. */
1272 * Resets the connection timeout task, some other message has done the
1274 * - For the first peer on the direction this means to send
1275 * a keepalive or a path confirmation message (either create or ACK).
1276 * - For all other peers, this means to destroy the connection,
1277 * due to lack of activity.
1278 * Starts the timeout if no timeout was running (connection just created).
1280 * @param c Connection whose timeout to reset.
1281 * @param fwd Is this forward?
1283 * TODO use heap to improve efficiency of scheduler.
1286 connection_reset_timeout (struct MeshConnection *c, int fwd)
1288 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s reset timeout\n", GM_f2s (fwd));
1290 if (GMC_is_origin (c, fwd)) /* Startpoint */
1292 schedule_next_keepalive (c, fwd);
1294 else /* Relay, endpoint. */
1296 struct GNUNET_TIME_Relative delay;
1297 GNUNET_SCHEDULER_TaskIdentifier *ti;
1298 GNUNET_SCHEDULER_Task f;
1300 ti = fwd ? &c->fwd_maintenance_task : &c->bck_maintenance_task;
1302 if (GNUNET_SCHEDULER_NO_TASK != *ti)
1303 GNUNET_SCHEDULER_cancel (*ti);
1304 delay = GNUNET_TIME_relative_multiply (refresh_connection_time, 4);
1305 f = fwd ? &connection_fwd_timeout : &connection_bck_timeout;
1306 *ti = GNUNET_SCHEDULER_add_delayed (delay, f, c);
1312 * Add the connection to the list of both neighbors.
1314 * @param c Connection.
1316 * @return #GNUNET_OK if everything went fine
1317 * #GNUNET_SYSERR if the was an error and @c c is malformed.
1320 register_neighbors (struct MeshConnection *c)
1322 struct MeshPeer *next_peer;
1323 struct MeshPeer *prev_peer;
1325 next_peer = get_next_hop (c);
1326 prev_peer = get_prev_hop (c);
1328 LOG (GNUNET_ERROR_TYPE_DEBUG, "register neighbors for connection %s\n",
1330 path_debug (c->path);
1331 LOG (GNUNET_ERROR_TYPE_DEBUG, "own pos %u\n", c->own_pos);
1332 LOG (GNUNET_ERROR_TYPE_DEBUG, "putting connection %s to next peer %p\n",
1333 GMC_2s (c), next_peer);
1334 LOG (GNUNET_ERROR_TYPE_DEBUG, "next peer %p %s\n", next_peer, GMP_2s (next_peer));
1335 LOG (GNUNET_ERROR_TYPE_DEBUG, "putting connection %s to prev peer %p\n",
1336 GMC_2s (c), prev_peer);
1337 LOG (GNUNET_ERROR_TYPE_DEBUG, "prev peer %p %s\n", prev_peer, GMP_2s (prev_peer));
1339 if (GNUNET_NO == GMP_is_neighbor (next_peer)
1340 || GNUNET_NO == GMP_is_neighbor (prev_peer))
1342 if (GMC_is_origin (c, GNUNET_YES))
1343 GNUNET_STATISTICS_update (stats, "# local bad paths", 1, GNUNET_NO);
1344 GNUNET_STATISTICS_update (stats, "# bad paths", 1, GNUNET_NO);
1346 LOG (GNUNET_ERROR_TYPE_DEBUG, " register neighbors failed\n");
1347 LOG (GNUNET_ERROR_TYPE_DEBUG, " prev: %s, neighbor?: %d\n",
1348 GMP_2s (prev_peer), GMP_is_neighbor (prev_peer));
1349 LOG (GNUNET_ERROR_TYPE_DEBUG, " next: %s, neighbor?: %d\n",
1350 GMP_2s (next_peer), GMP_is_neighbor (next_peer));
1351 return GNUNET_SYSERR;
1354 GMP_add_connection (next_peer, c);
1355 GMP_add_connection (prev_peer, c);
1362 * Remove the connection from the list of both neighbors.
1364 * @param c Connection.
1367 unregister_neighbors (struct MeshConnection *c)
1369 struct MeshPeer *peer;
1371 peer = get_next_hop (c);
1372 if (GNUNET_OK != GMP_remove_connection (peer, c))
1374 GNUNET_assert (MESH_CONNECTION_NEW == c->state
1375 || MESH_CONNECTION_DESTROYED == c->state);
1376 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate: %u\n", c->state);
1377 if (NULL != c->t) GMT_debug (c->t);
1380 peer = get_prev_hop (c);
1381 if (GNUNET_OK != GMP_remove_connection (peer, c))
1383 GNUNET_assert (MESH_CONNECTION_NEW == c->state
1384 || MESH_CONNECTION_DESTROYED == c->state);
1385 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate: %u\n", c->state);
1386 if (NULL != c->t) GMT_debug (c->t);
1392 * Bind the connection to the peer and the tunnel to that peer.
1394 * If the peer has no tunnel, create one. Update tunnel and connection
1395 * data structres to reflect new status.
1397 * @param c Connection.
1401 add_to_peer (struct MeshConnection *c, struct MeshPeer *peer)
1403 GMP_add_tunnel (peer);
1404 c->t = GMP_get_tunnel (peer);
1405 GMT_add_connection (c->t, c);
1410 * Builds a path from a PeerIdentity array.
1412 * @param peers PeerIdentity array.
1413 * @param size Size of the @c peers array.
1414 * @param own_pos Output parameter: own position in the path.
1416 * @return Fixed and shortened path.
1418 static struct MeshPeerPath *
1419 build_path_from_peer_ids (struct GNUNET_PeerIdentity *peers,
1421 unsigned int *own_pos)
1423 struct MeshPeerPath *path;
1424 GNUNET_PEER_Id shortid;
1427 unsigned int offset;
1430 LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating path...\n");
1431 path = path_new (size);
1434 for (i = 0; i < size; i++)
1436 LOG (GNUNET_ERROR_TYPE_DEBUG, " - %u: taking %s\n",
1437 i, GNUNET_i2s (&peers[i]));
1438 shortid = GNUNET_PEER_intern (&peers[i]);
1440 /* Check for loops / duplicates */
1441 for (j = 0; j < i - offset; j++)
1443 if (path->peers[j] == shortid)
1445 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists at pos %u\n", j);
1447 LOG (GNUNET_ERROR_TYPE_DEBUG, " offset now\n", offset);
1448 GNUNET_PEER_change_rc (shortid, -1);
1451 LOG (GNUNET_ERROR_TYPE_DEBUG, " storing at %u\n", i - offset);
1452 path->peers[i - offset] = shortid;
1453 if (path->peers[i] == myid)
1456 path->length -= offset;
1458 if (path->peers[*own_pos] != myid)
1460 /* create path: self not found in path through self */
1461 GNUNET_break_op (0);
1462 path_destroy (path);
1471 * Log receipt of message on stderr (INFO level).
1473 * @param message Message received.
1474 * @param peer Peer who sent the message.
1475 * @param hash Connection ID.
1478 log_message (const struct GNUNET_MessageHeader *message,
1479 const struct GNUNET_PeerIdentity *peer,
1480 const struct GNUNET_MeshHash *hash)
1482 LOG (GNUNET_ERROR_TYPE_INFO, "<- %s on connection %s from %s\n",
1483 GM_m2s (ntohs (message->type)), GNUNET_h2s (GM_h2hc (hash)),
1487 /******************************************************************************/
1488 /******************************** API ***********************************/
1489 /******************************************************************************/
1492 * Core handler for connection creation.
1494 * @param cls Closure (unused).
1495 * @param peer Sender (neighbor).
1496 * @param message Message.
1498 * @return GNUNET_OK to keep the connection open,
1499 * GNUNET_SYSERR to close it (signal serious error)
1502 GMC_handle_create (void *cls, const struct GNUNET_PeerIdentity *peer,
1503 const struct GNUNET_MessageHeader *message)
1505 struct GNUNET_MESH_ConnectionCreate *msg;
1506 struct GNUNET_PeerIdentity *id;
1507 struct GNUNET_MeshHash *cid;
1508 struct MeshPeerPath *path;
1509 struct MeshPeer *dest_peer;
1510 struct MeshPeer *orig_peer;
1511 struct MeshConnection *c;
1512 unsigned int own_pos;
1516 size = ntohs (message->size);
1517 if (size < sizeof (struct GNUNET_MESH_ConnectionCreate))
1519 GNUNET_break_op (0);
1523 /* Calculate hops */
1524 size -= sizeof (struct GNUNET_MESH_ConnectionCreate);
1525 if (size % sizeof (struct GNUNET_PeerIdentity))
1527 GNUNET_break_op (0);
1530 size /= sizeof (struct GNUNET_PeerIdentity);
1533 GNUNET_break_op (0);
1536 LOG (GNUNET_ERROR_TYPE_DEBUG, " path has %u hops.\n", size);
1538 /* Get parameters */
1539 msg = (struct GNUNET_MESH_ConnectionCreate *) message;
1541 log_message (message, peer, cid);
1542 id = (struct GNUNET_PeerIdentity *) &msg[1];
1543 LOG (GNUNET_ERROR_TYPE_DEBUG, " origin: %s\n", GNUNET_i2s (id));
1545 /* Create connection */
1546 c = connection_get (cid);
1549 path = build_path_from_peer_ids ((struct GNUNET_PeerIdentity *) &msg[1],
1555 GNUNET_break_op (0);
1556 path_destroy (path);
1559 LOG (GNUNET_ERROR_TYPE_DEBUG, " Own position: %u\n", own_pos);
1560 LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating connection\n");
1561 c = GMC_new (cid, NULL, path_duplicate (path), own_pos);
1564 if (path->length - 1 == own_pos)
1566 /* If we are destination, why did the creation fail? */
1570 send_broken2 (cid, &my_full_id,
1571 GNUNET_PEER_resolve2 (path->peers[own_pos + 1]),
1572 path->peers[own_pos - 1]);
1573 path_destroy (path);
1576 GMP_add_path_to_all (path, GNUNET_NO);
1577 connection_reset_timeout (c, GNUNET_YES);
1581 path = path_duplicate (c->path);
1583 if (MESH_CONNECTION_NEW == c->state)
1584 connection_change_state (c, MESH_CONNECTION_SENT);
1586 /* Remember peers */
1587 dest_peer = GMP_get (&id[size - 1]);
1588 orig_peer = GMP_get (&id[0]);
1590 /* Is it a connection to us? */
1591 if (c->own_pos == size - 1)
1593 LOG (GNUNET_ERROR_TYPE_DEBUG, " It's for us!\n");
1594 GMP_add_path_to_origin (orig_peer, path_duplicate (path), GNUNET_YES);
1596 add_to_peer (c, orig_peer);
1597 if (MESH_TUNNEL3_NEW == GMT_get_cstate (c->t))
1598 GMT_change_cstate (c->t, MESH_TUNNEL3_WAITING);
1600 send_connection_ack (c, GNUNET_NO);
1601 if (MESH_CONNECTION_SENT == c->state)
1602 connection_change_state (c, MESH_CONNECTION_ACK);
1606 /* It's for somebody else! Retransmit. */
1607 LOG (GNUNET_ERROR_TYPE_DEBUG, " Retransmitting.\n");
1608 GMP_add_path (dest_peer, path_duplicate (path), GNUNET_NO);
1609 GMP_add_path_to_origin (orig_peer, path_duplicate (path), GNUNET_NO);
1610 GMC_send_prebuilt_message (message, c, GNUNET_YES, GNUNET_YES,
1613 path_destroy (path);
1619 * Core handler for path confirmations.
1621 * @param cls closure
1622 * @param message message
1623 * @param peer peer identity this notification is about
1625 * @return GNUNET_OK to keep the connection open,
1626 * GNUNET_SYSERR to close it (signal serious error)
1629 GMC_handle_confirm (void *cls, const struct GNUNET_PeerIdentity *peer,
1630 const struct GNUNET_MessageHeader *message)
1632 struct GNUNET_MESH_ConnectionACK *msg;
1633 struct MeshConnection *c;
1634 struct MeshPeerPath *p;
1635 struct MeshPeer *pi;
1636 enum MeshConnectionState oldstate;
1639 msg = (struct GNUNET_MESH_ConnectionACK *) message;
1640 log_message (message, peer, &msg->cid);
1641 c = connection_get (&msg->cid);
1644 GNUNET_STATISTICS_update (stats, "# control on unknown connection",
1646 LOG (GNUNET_ERROR_TYPE_DEBUG, " don't know the connection!\n");
1650 if (GNUNET_NO != c->destroy)
1652 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection being destroyed\n");
1656 oldstate = c->state;
1657 LOG (GNUNET_ERROR_TYPE_DEBUG, " via peer %s\n", GNUNET_i2s (peer));
1658 pi = GMP_get (peer);
1659 if (get_next_hop (c) == pi)
1661 LOG (GNUNET_ERROR_TYPE_DEBUG, " SYNACK\n");
1663 if (MESH_CONNECTION_SENT == oldstate)
1664 connection_change_state (c, MESH_CONNECTION_ACK);
1666 else if (get_prev_hop (c) == pi)
1668 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK\n");
1670 connection_change_state (c, MESH_CONNECTION_READY);
1674 GNUNET_break_op (0);
1678 connection_reset_timeout (c, fwd);
1680 /* Add path to peers? */
1684 GMP_add_path_to_all (p, GNUNET_YES);
1691 /* Message for us as creator? */
1692 if (GMC_is_origin (c, GNUNET_YES))
1694 if (GNUNET_NO != fwd)
1696 GNUNET_break_op (0);
1699 LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection (SYN)ACK for us!\n");
1701 /* If just created, cancel the short timeout and start a long one */
1702 if (MESH_CONNECTION_SENT == oldstate)
1703 connection_reset_timeout (c, GNUNET_YES);
1705 /* Change connection state */
1706 connection_change_state (c, MESH_CONNECTION_READY);
1707 send_connection_ack (c, GNUNET_YES);
1709 /* Change tunnel state, trigger KX */
1710 if (MESH_TUNNEL3_WAITING == GMT_get_cstate (c->t))
1711 GMT_change_cstate (c->t, MESH_TUNNEL3_READY);
1716 /* Message for us as destination? */
1717 if (GMC_is_terminal (c, GNUNET_YES))
1719 if (GNUNET_YES != fwd)
1721 GNUNET_break_op (0);
1724 LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection ACK for us!\n");
1726 /* If just created, cancel the short timeout and start a long one */
1727 if (MESH_CONNECTION_ACK == oldstate)
1728 connection_reset_timeout (c, GNUNET_NO);
1730 /* Change tunnel state */
1731 if (MESH_TUNNEL3_WAITING == GMT_get_cstate (c->t))
1732 GMT_change_cstate (c->t, MESH_TUNNEL3_READY);
1737 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
1738 GMC_send_prebuilt_message (message, c, fwd, GNUNET_YES, NULL, NULL);
1744 * Core handler for notifications of broken paths
1746 * @param cls Closure (unused).
1747 * @param id Peer identity of sending neighbor.
1748 * @param message Message.
1750 * @return GNUNET_OK to keep the connection open,
1751 * GNUNET_SYSERR to close it (signal serious error)
1754 GMC_handle_broken (void* cls,
1755 const struct GNUNET_PeerIdentity* id,
1756 const struct GNUNET_MessageHeader* message)
1758 struct GNUNET_MESH_ConnectionBroken *msg;
1759 struct MeshConnection *c;
1762 msg = (struct GNUNET_MESH_ConnectionBroken *) message;
1763 log_message (message, id, &msg->cid);
1764 LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n",
1765 GNUNET_i2s (&msg->peer1));
1766 LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n",
1767 GNUNET_i2s (&msg->peer2));
1768 c = connection_get (&msg->cid);
1771 GNUNET_break_op (0);
1775 fwd = is_fwd (c, id);
1776 if (GMC_is_terminal (c, fwd))
1778 path_invalidate (c->path);
1779 if (0 < c->pending_messages)
1780 c->destroy = GNUNET_YES;
1786 GMC_send_prebuilt_message (message, c, fwd, GNUNET_YES, NULL, NULL);
1787 c->destroy = GNUNET_YES;
1788 connection_cancel_queues (c, !fwd);
1797 * Core handler for tunnel destruction
1799 * @param cls Closure (unused).
1800 * @param peer Peer identity of sending neighbor.
1801 * @param message Message.
1803 * @return GNUNET_OK to keep the connection open,
1804 * GNUNET_SYSERR to close it (signal serious error)
1807 GMC_handle_destroy (void *cls, const struct GNUNET_PeerIdentity *peer,
1808 const struct GNUNET_MessageHeader *message)
1810 struct GNUNET_MESH_ConnectionDestroy *msg;
1811 struct MeshConnection *c;
1814 msg = (struct GNUNET_MESH_ConnectionDestroy *) message;
1815 log_message (message, peer, &msg->cid);
1816 c = connection_get (&msg->cid);
1819 /* Probably already got the message from another path,
1820 * destroyed the tunnel and retransmitted to children.
1823 GNUNET_STATISTICS_update (stats, "# control on unknown connection",
1825 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection unknown: already destroyed?\n");
1828 fwd = is_fwd (c, peer);
1829 if (GNUNET_SYSERR == fwd)
1831 GNUNET_break_op (0); /* FIXME */
1834 if (GNUNET_NO == GMC_is_terminal (c, fwd))
1835 GMC_send_prebuilt_message (message, c, fwd, GNUNET_YES, NULL, NULL);
1836 else if (0 == c->pending_messages)
1838 LOG (GNUNET_ERROR_TYPE_DEBUG, "! directly destroying connection!\n");
1842 c->destroy = GNUNET_YES;
1843 c->state = MESH_CONNECTION_DESTROYED;
1846 GMT_remove_connection (c->t, c);
1854 * Generic handler for mesh network encrypted traffic.
1856 * @param peer Peer identity this notification is about.
1857 * @param msg Encrypted message.
1859 * @return GNUNET_OK to keep the connection open,
1860 * GNUNET_SYSERR to close it (signal serious error)
1863 handle_mesh_encrypted (const struct GNUNET_PeerIdentity *peer,
1864 const struct GNUNET_MESH_Encrypted *msg)
1866 struct MeshConnection *c;
1867 struct MeshPeer *neighbor;
1868 struct MeshFlowControl *fc;
1869 GNUNET_PEER_Id peer_id;
1875 log_message (&msg->header, peer, &msg->cid);
1878 size = ntohs (msg->header.size);
1880 sizeof (struct GNUNET_MESH_Encrypted) +
1881 sizeof (struct GNUNET_MessageHeader))
1883 GNUNET_break_op (0);
1887 /* Check connection */
1888 c = connection_get (&msg->cid);
1891 GNUNET_STATISTICS_update (stats, "# unknown connection", 1, GNUNET_NO);
1892 LOG (GNUNET_ERROR_TYPE_DEBUG, "enc on unknown connection %s\n",
1893 GNUNET_h2s (GM_h2hc (&msg->cid)));
1897 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s\n", GMC_2s (c));
1899 /* Check if origin is as expected */
1900 neighbor = get_prev_hop (c);
1901 peer_id = GNUNET_PEER_search (peer);
1902 if (peer_id == GMP_get_short_id (neighbor))
1908 neighbor = get_next_hop (c);
1909 if (peer_id == GMP_get_short_id (neighbor))
1915 /* Unexpected peer sending traffic on a connection. */
1916 GNUNET_break_op (0);
1922 fc = fwd ? &c->bck_fc : &c->fwd_fc;
1923 pid = ntohl (msg->pid);
1924 if (GM_is_pid_bigger (pid, fc->last_ack_sent))
1926 GNUNET_STATISTICS_update (stats, "# unsolicited message", 1, GNUNET_NO);
1927 LOG (GNUNET_ERROR_TYPE_DEBUG,
1928 "WARNING Received PID %u, (prev %u), ACK %u\n",
1929 pid, fc->last_pid_recv, fc->last_ack_sent);
1932 if (GNUNET_NO == GM_is_pid_bigger (pid, fc->last_pid_recv))
1934 GNUNET_STATISTICS_update (stats, "# duplicate PID", 1, GNUNET_NO);
1935 LOG (GNUNET_ERROR_TYPE_DEBUG,
1936 " Pid %u not expected (%u+), dropping!\n",
1937 pid, fc->last_pid_recv + 1);
1940 if (MESH_CONNECTION_SENT == c->state || MESH_CONNECTION_ACK == c->state)
1941 connection_change_state (c, MESH_CONNECTION_READY);
1942 connection_reset_timeout (c, fwd);
1943 fc->last_pid_recv = pid;
1945 /* Is this message for us? */
1946 if (GMC_is_terminal (c, fwd))
1948 LOG (GNUNET_ERROR_TYPE_DEBUG, " message for us!\n");
1949 GNUNET_STATISTICS_update (stats, "# messages received", 1, GNUNET_NO);
1953 GNUNET_break (GNUNET_NO != c->destroy);
1956 fc->last_pid_recv = pid;
1957 GMT_handle_encrypted (c->t, msg);
1958 GMC_send_ack (c, fwd, GNUNET_NO);
1962 /* Message not for us: forward to next hop */
1963 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
1964 ttl = ntohl (msg->ttl);
1965 LOG (GNUNET_ERROR_TYPE_DEBUG, " ttl: %u\n", ttl);
1968 GNUNET_STATISTICS_update (stats, "# TTL drops", 1, GNUNET_NO);
1969 LOG (GNUNET_ERROR_TYPE_WARNING, " TTL is 0, DROPPING!\n");
1970 GMC_send_ack (c, fwd, GNUNET_NO);
1974 GNUNET_STATISTICS_update (stats, "# messages forwarded", 1, GNUNET_NO);
1975 GMC_send_prebuilt_message (&msg->header, c, fwd, GNUNET_NO, NULL, NULL);
1981 * Generic handler for mesh network encrypted traffic.
1983 * @param peer Peer identity this notification is about.
1984 * @param msg Encrypted message.
1986 * @return GNUNET_OK to keep the connection open,
1987 * GNUNET_SYSERR to close it (signal serious error)
1990 handle_mesh_kx (const struct GNUNET_PeerIdentity *peer,
1991 const struct GNUNET_MESH_KX *msg)
1993 struct MeshConnection *c;
1994 struct MeshPeer *neighbor;
1995 GNUNET_PEER_Id peer_id;
1999 log_message (&msg->header, peer, &msg->cid);
2002 size = ntohs (msg->header.size);
2004 sizeof (struct GNUNET_MESH_KX) +
2005 sizeof (struct GNUNET_MessageHeader))
2007 GNUNET_break_op (0);
2011 /* Check connection */
2012 c = connection_get (&msg->cid);
2015 GNUNET_STATISTICS_update (stats, "# unknown connection", 1, GNUNET_NO);
2016 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx on unknown connection %s\n",
2017 GNUNET_h2s (GM_h2hc (&msg->cid)));
2020 LOG (GNUNET_ERROR_TYPE_DEBUG, " on connection %s\n", GMC_2s (c));
2022 /* Check if origin is as expected */
2023 neighbor = get_prev_hop (c);
2024 peer_id = GNUNET_PEER_search (peer);
2025 if (peer_id == GMP_get_short_id (neighbor))
2031 neighbor = get_next_hop (c);
2032 if (peer_id == GMP_get_short_id (neighbor))
2038 /* Unexpected peer sending traffic on a connection. */
2039 GNUNET_break_op (0);
2044 /* Count as connection confirmation. */
2045 if (MESH_CONNECTION_SENT == c->state || MESH_CONNECTION_ACK == c->state)
2047 connection_change_state (c, MESH_CONNECTION_READY);
2050 if (MESH_TUNNEL3_WAITING == GMT_get_cstate (c->t))
2051 GMT_change_cstate (c->t, MESH_TUNNEL3_READY);
2054 connection_reset_timeout (c, fwd);
2056 /* Is this message for us? */
2057 if (GMC_is_terminal (c, fwd))
2059 LOG (GNUNET_ERROR_TYPE_DEBUG, " message for us!\n");
2060 GNUNET_STATISTICS_update (stats, "# messages received", 1, GNUNET_NO);
2066 GMT_handle_kx (c->t, &msg[1].header);
2070 /* Message not for us: forward to next hop */
2071 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
2072 GNUNET_STATISTICS_update (stats, "# messages forwarded", 1, GNUNET_NO);
2073 GMC_send_prebuilt_message (&msg->header, c, fwd, GNUNET_NO, NULL, NULL);
2080 * Core handler for encrypted mesh network traffic (channel mgmt, data).
2082 * @param cls Closure (unused).
2083 * @param message Message received.
2084 * @param peer Peer who sent the message.
2086 * @return GNUNET_OK to keep the connection open,
2087 * GNUNET_SYSERR to close it (signal serious error)
2090 GMC_handle_encrypted (void *cls, const struct GNUNET_PeerIdentity *peer,
2091 const struct GNUNET_MessageHeader *message)
2093 return handle_mesh_encrypted (peer,
2094 (struct GNUNET_MESH_Encrypted *)message);
2099 * Core handler for key exchange traffic (ephemeral key, ping, pong).
2101 * @param cls Closure (unused).
2102 * @param message Message received.
2103 * @param peer Peer who sent the message.
2105 * @return GNUNET_OK to keep the connection open,
2106 * GNUNET_SYSERR to close it (signal serious error)
2109 GMC_handle_kx (void *cls, const struct GNUNET_PeerIdentity *peer,
2110 const struct GNUNET_MessageHeader *message)
2112 return handle_mesh_kx (peer,
2113 (struct GNUNET_MESH_KX *) message);
2118 * Core handler for mesh network traffic point-to-point acks.
2120 * @param cls closure
2121 * @param message message
2122 * @param peer peer identity this notification is about
2124 * @return GNUNET_OK to keep the connection open,
2125 * GNUNET_SYSERR to close it (signal serious error)
2128 GMC_handle_ack (void *cls, const struct GNUNET_PeerIdentity *peer,
2129 const struct GNUNET_MessageHeader *message)
2131 struct GNUNET_MESH_ACK *msg;
2132 struct MeshConnection *c;
2133 struct MeshFlowControl *fc;
2138 msg = (struct GNUNET_MESH_ACK *) message;
2139 log_message (message, peer, &msg->cid);
2140 c = connection_get (&msg->cid);
2143 GNUNET_STATISTICS_update (stats, "# ack on unknown connection", 1,
2148 /* Is this a forward or backward ACK? */
2149 id = GNUNET_PEER_search (peer);
2150 if (GMP_get_short_id (get_next_hop (c)) == id)
2152 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD ACK\n");
2156 else if (GMP_get_short_id (get_prev_hop (c)) == id)
2158 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK ACK\n");
2164 GNUNET_break_op (0);
2168 ack = ntohl (msg->ack);
2169 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK %u (was %u)\n",
2170 ack, fc->last_ack_recv);
2171 if (GM_is_pid_bigger (ack, fc->last_ack_recv))
2172 fc->last_ack_recv = ack;
2174 /* Cancel polling if the ACK is big enough. */
2175 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task &&
2176 GM_is_pid_bigger (fc->last_ack_recv, fc->last_pid_sent))
2178 LOG (GNUNET_ERROR_TYPE_DEBUG, " Cancel poll\n");
2179 GNUNET_SCHEDULER_cancel (fc->poll_task);
2180 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
2181 fc->poll_time = GNUNET_TIME_UNIT_SECONDS;
2184 connection_unlock_queue (c, fwd);
2191 * Core handler for mesh network traffic point-to-point ack polls.
2193 * @param cls closure
2194 * @param message message
2195 * @param peer peer identity this notification is about
2197 * @return GNUNET_OK to keep the connection open,
2198 * GNUNET_SYSERR to close it (signal serious error)
2201 GMC_handle_poll (void *cls, const struct GNUNET_PeerIdentity *peer,
2202 const struct GNUNET_MessageHeader *message)
2204 struct GNUNET_MESH_Poll *msg;
2205 struct MeshConnection *c;
2206 struct MeshFlowControl *fc;
2211 msg = (struct GNUNET_MESH_Poll *) message;
2212 log_message (message, peer, &msg->cid);
2213 c = connection_get (&msg->cid);
2216 GNUNET_STATISTICS_update (stats, "# poll on unknown connection", 1,
2218 LOG (GNUNET_ERROR_TYPE_DEBUG,
2219 "WARNING POLL message on unknown connection %s!\n",
2220 GNUNET_h2s (GM_h2hc (&msg->cid)));
2224 /* Is this a forward or backward ACK?
2225 * Note: a poll should never be needed in a loopback case,
2226 * since there is no possiblility of packet loss there, so
2227 * this way of discerining FWD/BCK should not be a problem.
2229 id = GNUNET_PEER_search (peer);
2230 if (GMP_get_short_id (get_next_hop (c)) == id)
2232 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD FC\n");
2235 else if (GMP_get_short_id (get_prev_hop (c)) == id)
2237 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK FC\n");
2242 GNUNET_break_op (0);
2246 pid = ntohl (msg->pid);
2247 LOG (GNUNET_ERROR_TYPE_DEBUG, " PID %u, OLD %u\n", pid, fc->last_pid_recv);
2248 fc->last_pid_recv = pid;
2249 fwd = fc == &c->bck_fc;
2250 GMC_send_ack (c, fwd, GNUNET_YES);
2257 * Send an ACK on the appropriate connection/channel, depending on
2258 * the direction and the position of the peer.
2260 * @param c Which connection to send the hop-by-hop ACK.
2261 * @param fwd Is this a fwd ACK? (will go dest->root).
2262 * @param force Send the ACK even if suboptimal (e.g. requested by POLL).
2265 GMC_send_ack (struct MeshConnection *c, int fwd, int force)
2267 unsigned int buffer;
2269 LOG (GNUNET_ERROR_TYPE_DEBUG,
2270 "GMC send %s ACK on %s\n",
2271 GM_f2s (fwd), GMC_2s (c));
2279 if (GNUNET_NO != c->destroy)
2281 LOG (GNUNET_ERROR_TYPE_DEBUG, " being destroyed, why bother...\n");
2285 /* Get available buffer space */
2286 if (GMC_is_terminal (c, fwd))
2288 LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from all channels\n");
2289 buffer = GMT_get_channels_buffer (c->t);
2293 LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from one connection\n");
2294 buffer = GMC_get_buffer (c, fwd);
2296 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer available: %u\n", buffer);
2297 if (0 == buffer && GNUNET_NO == force)
2300 /* Send available buffer space */
2301 if (GMC_is_origin (c, fwd))
2303 GNUNET_assert (NULL != c->t);
2304 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channels...\n");
2305 GMT_unchoke_channels (c->t);
2309 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on connection\n");
2310 send_ack (c, buffer, fwd, force);
2316 * Initialize the connections subsystem
2318 * @param c Configuration handle.
2321 GMC_init (const struct GNUNET_CONFIGURATION_Handle *c)
2323 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
2325 GNUNET_CONFIGURATION_get_value_number (c, "MESH", "MAX_MSGS_QUEUE",
2328 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
2329 "MESH", "MAX_MSGS_QUEUE", "MISSING");
2330 GNUNET_SCHEDULER_shutdown ();
2335 GNUNET_CONFIGURATION_get_value_number (c, "MESH", "MAX_CONNECTIONS",
2338 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
2339 "MESH", "MAX_CONNECTIONS", "MISSING");
2340 GNUNET_SCHEDULER_shutdown ();
2345 GNUNET_CONFIGURATION_get_value_time (c, "MESH", "REFRESH_CONNECTION_TIME",
2346 &refresh_connection_time))
2348 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
2349 "MESH", "REFRESH_CONNECTION_TIME", "MISSING");
2350 GNUNET_SCHEDULER_shutdown ();
2353 create_connection_time = GNUNET_TIME_UNIT_SECONDS;
2354 connections = GNUNET_CONTAINER_multihashmap_create (1024, GNUNET_YES);
2359 * Destroy each connection on shutdown.
2361 * @param cls Closure (unused).
2362 * @param key Current key code (CID, unused).
2363 * @param value Value in the hash map (connection)
2365 * @return #GNUNET_YES, because we should continue to iterate,
2368 shutdown_iterator (void *cls,
2369 const struct GNUNET_HashCode *key,
2372 struct MeshConnection *c = value;
2380 * Shut down the connections subsystem.
2385 GNUNET_CONTAINER_multihashmap_iterate (connections, &shutdown_iterator, NULL);
2386 GNUNET_CONTAINER_multihashmap_destroy (connections);
2391 struct MeshConnection *
2392 GMC_new (const struct GNUNET_MeshHash *cid,
2393 struct MeshTunnel3 *t,
2394 struct MeshPeerPath *p,
2395 unsigned int own_pos)
2397 struct MeshConnection *c;
2399 c = GNUNET_new (struct MeshConnection);
2401 GNUNET_assert (GNUNET_OK ==
2402 GNUNET_CONTAINER_multihashmap_put (connections,
2404 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
2405 fc_init (&c->fwd_fc);
2406 fc_init (&c->bck_fc);
2411 GNUNET_assert (own_pos <= p->length - 1);
2412 c->own_pos = own_pos;
2415 if (GNUNET_OK != register_neighbors (c))
2419 path_invalidate (c->path);
2432 GMC_destroy (struct MeshConnection *c)
2440 if (2 == c->destroy) /* cancel queues -> GMP_queue_cancel -> q_destroy -> */
2441 return; /* -> message_sent -> GMC_destroy. Don't loop. */
2444 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying connection %s\n", GMC_2s (c));
2445 LOG (GNUNET_ERROR_TYPE_DEBUG, " fc's f: %p, b: %p\n",
2446 &c->fwd_fc, &c->bck_fc);
2447 LOG (GNUNET_ERROR_TYPE_DEBUG, " fc tasks f: %u, b: %u\n",
2448 c->fwd_fc.poll_task, c->bck_fc.poll_task);
2450 /* Cancel all traffic */
2451 if (NULL != c->path)
2453 connection_cancel_queues (c, GNUNET_YES);
2454 connection_cancel_queues (c, GNUNET_NO);
2455 unregister_neighbors (c);
2458 LOG (GNUNET_ERROR_TYPE_DEBUG, " fc tasks f: %u, b: %u\n",
2459 c->fwd_fc.poll_task, c->bck_fc.poll_task);
2461 /* Cancel maintainance task (keepalive/timeout) */
2462 if (NULL != c->fwd_fc.poll_msg)
2464 GMC_cancel (c->fwd_fc.poll_msg);
2465 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL msg FWD canceled\n");
2467 if (NULL != c->bck_fc.poll_msg)
2469 GMC_cancel (c->bck_fc.poll_msg);
2470 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL msg BCK canceled\n");
2473 /* Delete from tunnel */
2475 GMT_remove_connection (c->t, c);
2477 if (GNUNET_NO == GMC_is_origin (c, GNUNET_YES) && NULL != c->path)
2478 path_destroy (c->path);
2479 if (GNUNET_SCHEDULER_NO_TASK != c->fwd_maintenance_task)
2480 GNUNET_SCHEDULER_cancel (c->fwd_maintenance_task);
2481 if (GNUNET_SCHEDULER_NO_TASK != c->bck_maintenance_task)
2482 GNUNET_SCHEDULER_cancel (c->bck_maintenance_task);
2483 if (GNUNET_SCHEDULER_NO_TASK != c->fwd_fc.poll_task)
2485 GNUNET_SCHEDULER_cancel (c->fwd_fc.poll_task);
2486 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL FWD canceled\n");
2488 if (GNUNET_SCHEDULER_NO_TASK != c->bck_fc.poll_task)
2490 GNUNET_SCHEDULER_cancel (c->bck_fc.poll_task);
2491 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL BCK canceled\n");
2494 GNUNET_break (GNUNET_YES ==
2495 GNUNET_CONTAINER_multihashmap_remove (connections,
2498 GNUNET_STATISTICS_update (stats, "# connections", -1, GNUNET_NO);
2503 * Get the connection ID.
2505 * @param c Connection to get the ID from.
2507 * @return ID of the connection.
2509 const struct GNUNET_MeshHash *
2510 GMC_get_id (const struct MeshConnection *c)
2517 * Get the connection ID.
2519 * @param c Connection to get the ID from.
2521 * @return ID of the connection.
2523 const struct GNUNET_HashCode *
2524 GMC_get_h (const struct MeshConnection *c)
2526 return GM_h2hc (&c->id);
2531 * Get the connection path.
2533 * @param c Connection to get the path from.
2535 * @return path used by the connection.
2537 const struct MeshPeerPath *
2538 GMC_get_path (const struct MeshConnection *c)
2540 if (GNUNET_NO == c->destroy)
2547 * Get the connection state.
2549 * @param c Connection to get the state from.
2551 * @return state of the connection.
2553 enum MeshConnectionState
2554 GMC_get_state (const struct MeshConnection *c)
2560 * Get the connection tunnel.
2562 * @param c Connection to get the tunnel from.
2564 * @return tunnel of the connection.
2566 struct MeshTunnel3 *
2567 GMC_get_tunnel (const struct MeshConnection *c)
2574 * Get free buffer space in a connection.
2576 * @param c Connection.
2577 * @param fwd Is query about FWD traffic?
2579 * @return Free buffer space [0 - max_msgs_queue/max_connections]
2582 GMC_get_buffer (struct MeshConnection *c, int fwd)
2584 struct MeshFlowControl *fc;
2586 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2588 return (fc->queue_max - fc->queue_n);
2592 * Get how many messages have we allowed to send to us from a direction.
2594 * @param c Connection.
2595 * @param fwd Are we asking about traffic from FWD (BCK messages)?
2597 * @return last_ack_sent - last_pid_recv
2600 GMC_get_allowed (struct MeshConnection *c, int fwd)
2602 struct MeshFlowControl *fc;
2604 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2605 if (GM_is_pid_bigger(fc->last_pid_recv, fc->last_ack_sent))
2609 return (fc->last_ack_sent - fc->last_pid_recv);
2613 * Get messages queued in a connection.
2615 * @param c Connection.
2616 * @param fwd Is query about FWD traffic?
2618 * @return Number of messages queued.
2621 GMC_get_qn (struct MeshConnection *c, int fwd)
2623 struct MeshFlowControl *fc;
2625 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2632 * Allow the connection to advertise a buffer of the given size.
2634 * The connection will send an @c fwd ACK message (so: in direction !fwd)
2635 * allowing up to last_pid_recv + buffer.
2637 * @param c Connection.
2638 * @param buffer How many more messages the connection can accept.
2639 * @param fwd Is this about FWD traffic? (The ack will go dest->root).
2642 GMC_allow (struct MeshConnection *c, unsigned int buffer, int fwd)
2644 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowing %s %u messages %s\n",
2645 GMC_2s (c), buffer, GM_f2s (fwd));
2646 send_ack (c, buffer, fwd, GNUNET_NO);
2651 * Notify other peers on a connection of a broken link. Mark connections
2652 * to destroy after all traffic has been sent.
2654 * @param c Connection on which there has been a disconnection.
2655 * @param peer Peer that disconnected.
2658 GMC_notify_broken (struct MeshConnection *c,
2659 struct MeshPeer *peer)
2663 LOG (GNUNET_ERROR_TYPE_DEBUG,
2664 " notify broken on %s due to %s disconnect\n",
2665 GMC_2s (c), GMP_2s (peer));
2667 fwd = peer == get_prev_hop (c);
2669 if (GNUNET_YES == GMC_is_terminal (c, fwd))
2671 /* Local shutdown, no one to notify about this. */
2675 if (GNUNET_NO == c->destroy)
2676 send_broken (c, &my_full_id, GMP_get_id (peer), fwd);
2678 /* Connection will have at least one pending message
2679 * (the one we just scheduled), so no point in checking whether to
2680 * destroy immediately. */
2681 c->destroy = GNUNET_YES;
2682 c->state = MESH_CONNECTION_DESTROYED;
2685 * Cancel all queues, if no message is left, connection will be destroyed.
2687 connection_cancel_queues (c, !fwd);
2694 * Is this peer the first one on the connection?
2696 * @param c Connection.
2697 * @param fwd Is this about fwd traffic?
2699 * @return #GNUNET_YES if origin, #GNUNET_NO if relay/terminal.
2702 GMC_is_origin (struct MeshConnection *c, int fwd)
2704 if (!fwd && c->path->length - 1 == c->own_pos )
2706 if (fwd && 0 == c->own_pos)
2713 * Is this peer the last one on the connection?
2715 * @param c Connection.
2716 * @param fwd Is this about fwd traffic?
2717 * Note that the ROOT is the terminal for BCK traffic!
2719 * @return #GNUNET_YES if terminal, #GNUNET_NO if relay/origin.
2722 GMC_is_terminal (struct MeshConnection *c, int fwd)
2724 return GMC_is_origin (c, !fwd);
2729 * See if we are allowed to send by the next hop in the given direction.
2731 * @param c Connection.
2732 * @param fwd Is this about fwd traffic?
2734 * @return #GNUNET_YES in case it's OK to send.
2737 GMC_is_sendable (struct MeshConnection *c, int fwd)
2739 struct MeshFlowControl *fc;
2746 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2747 if (GM_is_pid_bigger (fc->last_ack_recv, fc->last_pid_sent))
2753 * Sends an already built message on a connection, properly registering
2754 * all used resources.
2756 * @param message Message to send. Function makes a copy of it.
2757 * If message is not hop-by-hop, decrements TTL of copy.
2758 * @param c Connection on which this message is transmitted.
2759 * @param fwd Is this a fwd message?
2760 * @param force Force the connection to accept the message (buffer overfill).
2761 * @param cont Continuation called once message is sent. Can be NULL.
2762 * @param cont_cls Closure for @c cont.
2764 * @return Handle to cancel the message before it's sent.
2765 * NULL on error or if @c cont is NULL.
2766 * Invalid on @c cont call.
2768 struct MeshConnectionQueue *
2769 GMC_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2770 struct MeshConnection *c, int fwd, int force,
2771 GMC_sent cont, void *cont_cls)
2773 struct MeshFlowControl *fc;
2774 struct MeshConnectionQueue *q;
2780 size = ntohs (message->size);
2781 data = GNUNET_malloc (size);
2782 memcpy (data, message, size);
2783 type = ntohs (message->type);
2784 LOG (GNUNET_ERROR_TYPE_INFO, "-> %s on connection %s (%u bytes)\n",
2785 GM_m2s (type), GMC_2s (c), size);
2787 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2788 droppable = GNUNET_NO == force;
2791 struct GNUNET_MESH_Encrypted *emsg;
2792 struct GNUNET_MESH_KX *kmsg;
2793 struct GNUNET_MESH_ACK *amsg;
2794 struct GNUNET_MESH_Poll *pmsg;
2795 struct GNUNET_MESH_ConnectionDestroy *dmsg;
2796 struct GNUNET_MESH_ConnectionBroken *bmsg;
2799 case GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED:
2800 emsg = (struct GNUNET_MESH_Encrypted *) data;
2801 ttl = ntohl (emsg->ttl);
2804 GNUNET_break_op (0);
2809 emsg->ttl = htonl (ttl - 1);
2810 emsg->pid = htonl (fc->next_pid++);
2811 LOG (GNUNET_ERROR_TYPE_DEBUG, " Q_N+ %p %u\n", fc, fc->queue_n);
2812 if (GNUNET_YES == droppable)
2815 LOG (GNUNET_ERROR_TYPE_DEBUG, "pid %u\n", ntohl (emsg->pid));
2816 LOG (GNUNET_ERROR_TYPE_DEBUG, "last pid sent %u\n", fc->last_pid_sent);
2817 LOG (GNUNET_ERROR_TYPE_DEBUG, " ack recv %u\n", fc->last_ack_recv);
2821 LOG (GNUNET_ERROR_TYPE_DEBUG, " not droppable, Q_N stays the same\n");
2823 if (GM_is_pid_bigger (fc->last_pid_sent + 1, fc->last_ack_recv))
2825 GMC_start_poll (c, fwd);
2829 case GNUNET_MESSAGE_TYPE_MESH_KX:
2830 kmsg = (struct GNUNET_MESH_KX *) data;
2834 case GNUNET_MESSAGE_TYPE_MESH_ACK:
2835 amsg = (struct GNUNET_MESH_ACK *) data;
2837 LOG (GNUNET_ERROR_TYPE_DEBUG, " ack %u\n", ntohl (amsg->ack));
2838 droppable = GNUNET_NO;
2841 case GNUNET_MESSAGE_TYPE_MESH_POLL:
2842 pmsg = (struct GNUNET_MESH_Poll *) data;
2844 LOG (GNUNET_ERROR_TYPE_DEBUG, " poll %u\n", ntohl (pmsg->pid));
2845 droppable = GNUNET_NO;
2848 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_DESTROY:
2849 dmsg = (struct GNUNET_MESH_ConnectionDestroy *) data;
2853 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_BROKEN:
2854 bmsg = (struct GNUNET_MESH_ConnectionBroken *) data;
2858 case GNUNET_MESSAGE_TYPE_MESH_KEEPALIVE:
2861 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_CREATE:
2862 case GNUNET_MESSAGE_TYPE_MESH_CONNECTION_ACK:
2871 if (fc->queue_n > fc->queue_max && droppable)
2873 GNUNET_STATISTICS_update (stats, "# messages dropped (buffer full)",
2876 LOG (GNUNET_ERROR_TYPE_DEBUG,
2877 "queue full: %u/%u\n",
2878 fc->queue_n, fc->queue_max);
2879 if (GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED == type)
2885 return NULL; /* Drop this message */
2888 LOG (GNUNET_ERROR_TYPE_DEBUG, " C_P+ %p %u\n", c, c->pending_messages);
2889 c->pending_messages++;
2891 q = GNUNET_new (struct MeshConnectionQueue);
2892 q->forced = !droppable;
2893 q->q = GMP_queue_add (get_hop (c, fwd), data, type, size, c, fwd,
2897 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING dropping msg on %s\n", GMC_2s (c));
2903 q->cont_cls = cont_cls;
2909 * Cancel a previously sent message while it's in the queue.
2911 * ONLY can be called before the continuation given to the send function
2912 * is called. Once the continuation is called, the message is no longer in the
2915 * @param q Handle to the queue.
2918 GMC_cancel (struct MeshConnectionQueue *q)
2920 LOG (GNUNET_ERROR_TYPE_DEBUG, "! GMC cancel message\n");
2922 /* queue destroy calls message_sent, which calls q->cont and frees q */
2923 GMP_queue_destroy (q->q, GNUNET_YES);
2928 * Sends a CREATE CONNECTION message for a path to a peer.
2929 * Changes the connection and tunnel states if necessary.
2931 * @param connection Connection to create.
2934 GMC_send_create (struct MeshConnection *connection)
2936 enum MeshTunnel3CState state;
2939 size = sizeof (struct GNUNET_MESH_ConnectionCreate);
2940 size += connection->path->length * sizeof (struct GNUNET_PeerIdentity);
2942 LOG (GNUNET_ERROR_TYPE_INFO, "=> %s on connection %s (%u bytes)\n",
2943 GM_m2s (GNUNET_MESSAGE_TYPE_MESH_CONNECTION_CREATE),
2944 GMC_2s (connection), size);
2945 LOG (GNUNET_ERROR_TYPE_DEBUG, " C_P+ %p %u (create)\n",
2946 connection, connection->pending_messages);
2947 connection->pending_messages++;
2949 connection->maintenance_q =
2950 GMP_queue_add (get_next_hop (connection), NULL,
2951 GNUNET_MESSAGE_TYPE_MESH_CONNECTION_CREATE,
2952 size, connection, GNUNET_YES, &message_sent, NULL);
2954 state = GMT_get_cstate (connection->t);
2955 if (MESH_TUNNEL3_SEARCHING == state || MESH_TUNNEL3_NEW == state)
2956 GMT_change_cstate (connection->t, MESH_TUNNEL3_WAITING);
2957 if (MESH_CONNECTION_NEW == connection->state)
2958 connection_change_state (connection, MESH_CONNECTION_SENT);
2963 * Send a message to all peers in this connection that the connection
2964 * is no longer valid.
2966 * If some peer should not receive the message, it should be zero'ed out
2967 * before calling this function.
2969 * @param c The connection whose peers to notify.
2972 GMC_send_destroy (struct MeshConnection *c)
2974 struct GNUNET_MESH_ConnectionDestroy msg;
2976 if (GNUNET_YES == c->destroy)
2979 msg.header.size = htons (sizeof (msg));
2980 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CONNECTION_DESTROY);;
2982 LOG (GNUNET_ERROR_TYPE_DEBUG,
2983 " sending connection destroy for connection %s\n",
2986 if (GNUNET_NO == GMC_is_terminal (c, GNUNET_YES))
2987 GMC_send_prebuilt_message (&msg.header, c,
2988 GNUNET_YES, GNUNET_YES, NULL, NULL);
2989 if (GNUNET_NO == GMC_is_terminal (c, GNUNET_NO))
2990 GMC_send_prebuilt_message (&msg.header, c,
2991 GNUNET_NO, GNUNET_YES, NULL, NULL);
2992 c->destroy = GNUNET_YES;
2993 c->state = MESH_CONNECTION_DESTROYED;
2998 * @brief Start a polling timer for the connection.
3000 * When a neighbor does not accept more traffic on the connection it could be
3001 * caused by a simple congestion or by a lost ACK. Polling enables to check
3002 * for the lastest ACK status for a connection.
3004 * @param c Connection.
3005 * @param fwd Should we poll in the FWD direction?
3008 GMC_start_poll (struct MeshConnection *c, int fwd)
3010 struct MeshFlowControl *fc;
3012 fc = fwd ? &c->fwd_fc : &c->bck_fc;
3013 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL %s requested\n",
3015 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task || NULL != fc->poll_msg)
3017 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** not needed (%u, %p)\n",
3018 fc->poll_task, fc->poll_msg);
3021 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL started on request\n");
3022 fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time,
3029 * @brief Stop polling a connection for ACKs.
3031 * Once we have enough ACKs for future traffic, polls are no longer necessary.
3033 * @param c Connection.
3034 * @param fwd Should we stop the poll in the FWD direction?
3037 GMC_stop_poll (struct MeshConnection *c, int fwd)
3039 struct MeshFlowControl *fc;
3041 fc = fwd ? &c->fwd_fc : &c->bck_fc;
3042 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task)
3044 GNUNET_SCHEDULER_cancel (fc->poll_task);
3045 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
3050 * Get a (static) string for a connection.
3052 * @param c Connection.
3055 GMC_2s (const struct MeshConnection *c)
3062 static char buf[128];
3064 sprintf (buf, "%s (->%s)", GNUNET_h2s (GM_h2hc (GMC_get_id(c))), GMT_2s (c->t));
3067 return GNUNET_h2s (GM_h2hc (&c->id));