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 cadet/gnunet-service-cadet_connection.c
23 * @brief GNUnet CADET service connection handling
24 * @author Bartlomiej Polot
28 #include "gnunet_util_lib.h"
30 #include "gnunet_statistics_service.h"
32 #include "cadet_path.h"
33 #include "cadet_protocol.h"
35 #include "gnunet-service-cadet_connection.h"
36 #include "gnunet-service-cadet_peer.h"
37 #include "gnunet-service-cadet_tunnel.h"
40 #define LOG(level, ...) GNUNET_log_from (level,"cadet-con",__VA_ARGS__)
42 #define CADET_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 CadetFlowControl
59 * Connection this controls.
61 struct CadetConnection *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;
74 * ID of the last packet sent towards the peer.
76 uint32_t last_pid_sent;
79 * ID of the last packet received from the peer.
81 uint32_t last_pid_recv;
84 * Last ACK sent to the peer (peer can't send more than this PID).
86 uint32_t last_ack_sent;
89 * Last ACK sent towards the origin (for traffic towards leaf node).
91 uint32_t last_ack_recv;
94 * Task to poll the peer in case of a lost ACK causes stall.
96 GNUNET_SCHEDULER_TaskIdentifier poll_task;
99 * How frequently to poll for ACKs.
101 struct GNUNET_TIME_Relative poll_time;
104 * Queued poll message, to cancel if not necessary anymore (got ACK).
106 struct CadetConnectionQueue *poll_msg;
109 * Queued poll message, to cancel if not necessary anymore (got ACK).
111 struct CadetConnectionQueue *ack_msg;
115 * Keep a record of the last messages sent on this connection.
117 struct CadetConnectionPerformance
120 * Circular buffer for storing measurements.
122 double usecsperbyte[AVG_MSGS];
125 * Running average of @c usecsperbyte.
130 * How many values of @c usecsperbyte are valid.
135 * Index of the next "free" position in @c usecsperbyte.
142 * Struct containing all information regarding a connection to a peer.
144 struct CadetConnection
147 * Tunnel this connection is part of.
149 struct CadetTunnel *t;
152 * Flow control information for traffic fwd.
154 struct CadetFlowControl fwd_fc;
157 * Flow control information for traffic bck.
159 struct CadetFlowControl bck_fc;
162 * Measure connection performance on the endpoint.
164 struct CadetConnectionPerformance *perf;
167 * ID of the connection.
169 struct GNUNET_CADET_Hash id;
172 * State of the connection.
174 enum CadetConnectionState state;
177 * Path being used for the tunnel. At the origin of the connection
178 * it's a pointer to the destination's path pool, otherwise just a copy.
180 struct CadetPeerPath *path;
183 * Position of the local peer in the path.
185 unsigned int own_pos;
188 * Task to keep the used paths alive at the owner,
189 * time tunnel out on all the other peers.
191 GNUNET_SCHEDULER_TaskIdentifier fwd_maintenance_task;
194 * Task to keep the used paths alive at the destination,
195 * time tunnel out on all the other peers.
197 GNUNET_SCHEDULER_TaskIdentifier bck_maintenance_task;
200 * Queue handle for maintainance traffic. One handle for FWD and BCK since
201 * one peer never needs to maintain both directions (no loopback connections).
203 struct CadetPeerQueue *maintenance_q;
206 * Counter to do exponential backoff when creating a connection (max 64).
208 unsigned short create_retry;
211 * Pending message count.
213 int pending_messages;
216 * Destroy flag: if true, destroy on last message.
222 * Handle for messages queued but not yet sent.
224 struct CadetConnectionQueue
227 * Peer queue handle, to cancel if necessary.
229 struct CadetPeerQueue *q;
232 * Was this a forced message? (Do not account for it)
237 * Continuation to call once sent.
242 * Closure for @c cont.
247 /******************************************************************************/
248 /******************************* GLOBALS ***********************************/
249 /******************************************************************************/
252 * Global handle to the statistics service.
254 extern struct GNUNET_STATISTICS_Handle *stats;
257 * Local peer own ID (memory efficient handle).
259 extern GNUNET_PEER_Id myid;
262 * Local peer own ID (full value).
264 extern struct GNUNET_PeerIdentity my_full_id;
267 * Connections known, indexed by cid (CadetConnection).
269 static struct GNUNET_CONTAINER_MultiHashMap *connections;
272 * How many connections are we willing to maintain.
273 * Local connections are always allowed, even if there are more connections than max.
275 static unsigned long long max_connections;
278 * How many messages *in total* are we willing to queue, divide by number of
279 * connections to get connection queue size.
281 static unsigned long long max_msgs_queue;
284 * How often to send path keepalives. Paths timeout after 4 missed.
286 static struct GNUNET_TIME_Relative refresh_connection_time;
289 * How often to send path create / ACKs.
291 static struct GNUNET_TIME_Relative create_connection_time;
294 /******************************************************************************/
295 /******************************** STATIC ***********************************/
296 /******************************************************************************/
298 #if 0 // avoid compiler warning for unused static function
300 fc_debug (struct CadetFlowControl *fc)
302 LOG (GNUNET_ERROR_TYPE_DEBUG, " IN: %u/%u\n",
303 fc->last_pid_recv, fc->last_ack_sent);
304 LOG (GNUNET_ERROR_TYPE_DEBUG, " OUT: %u/%u\n",
305 fc->last_pid_sent, fc->last_ack_recv);
306 LOG (GNUNET_ERROR_TYPE_DEBUG, " QUEUE: %u/%u\n",
307 fc->queue_n, fc->queue_max);
311 connection_debug (struct CadetConnection *c)
315 LOG (GNUNET_ERROR_TYPE_DEBUG, "*** DEBUG NULL CONNECTION ***\n");
318 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s:%X\n",
319 peer2s (c->t->peer), GCC_2s (c));
320 LOG (GNUNET_ERROR_TYPE_DEBUG, " state: %u, pending msgs: %u\n",
321 c->state, c->pending_messages);
322 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD FC\n");
323 fc_debug (&c->fwd_fc);
324 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK FC\n");
325 fc_debug (&c->bck_fc);
331 * Schedule next keepalive task, taking in consideration
332 * the connection state and number of retries.
334 * @param c Connection for which to schedule the next keepalive.
335 * @param fwd Direction for the next keepalive.
338 schedule_next_keepalive (struct CadetConnection *c, int fwd);
342 * Resets the connection timeout task, some other message has done the
344 * - For the first peer on the direction this means to send
345 * a keepalive or a path confirmation message (either create or ACK).
346 * - For all other peers, this means to destroy the connection,
347 * due to lack of activity.
348 * Starts the timeout if no timeout was running (connection just created).
350 * @param c Connection whose timeout to reset.
351 * @param fwd Is this forward?
354 connection_reset_timeout (struct CadetConnection *c, int fwd);
358 * Get string description for tunnel state. Reentrant.
360 * @param s Tunnel state.
362 * @return String representation.
365 GCC_state2s (enum CadetConnectionState s)
369 case CADET_CONNECTION_NEW:
370 return "CADET_CONNECTION_NEW";
371 case CADET_CONNECTION_SENT:
372 return "CADET_CONNECTION_SENT";
373 case CADET_CONNECTION_ACK:
374 return "CADET_CONNECTION_ACK";
375 case CADET_CONNECTION_READY:
376 return "CADET_CONNECTION_READY";
377 case CADET_CONNECTION_DESTROYED:
378 return "CADET_CONNECTION_DESTROYED";
380 return "CADET_CONNECTION_STATE_ERROR";
386 * Initialize a Flow Control structure to the initial state.
388 * @param fc Flow Control structure to initialize.
391 fc_init (struct CadetFlowControl *fc)
393 fc->last_pid_sent = (uint32_t) -1; /* Next (expected) = 0 */
394 fc->last_pid_recv = (uint32_t) -1;
395 fc->last_ack_sent = (uint32_t) 0;
396 fc->last_ack_recv = (uint32_t) 0;
397 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
398 fc->poll_time = GNUNET_TIME_UNIT_SECONDS;
400 fc->queue_max = (max_msgs_queue / max_connections) + 1;
407 * @param cid Connection ID.
409 static struct CadetConnection *
410 connection_get (const struct GNUNET_CADET_Hash *cid)
412 return GNUNET_CONTAINER_multihashmap_get (connections, GC_h2hc (cid));
417 connection_change_state (struct CadetConnection* c,
418 enum CadetConnectionState state)
420 LOG (GNUNET_ERROR_TYPE_DEBUG,
421 "Connection %s state %s -> %s\n",
422 GCC_2s (c), GCC_state2s (c->state), GCC_state2s (state));
423 if (CADET_CONNECTION_DESTROYED == c->state)
425 LOG (GNUNET_ERROR_TYPE_DEBUG, "state not changing anymore\n");
429 if (CADET_CONNECTION_READY == state)
435 * Callback called when a queued ACK message is sent.
437 * @param cls Closure (FC).
438 * @param c Connection this message was on.
439 * @param q Queue handler this call invalidates.
440 * @param type Type of message sent.
441 * @param fwd Was this a FWD going message?
442 * @param size Size of the message.
446 struct CadetConnection *c,
447 struct CadetConnectionQueue *q,
448 uint16_t type, int fwd, size_t size)
450 struct CadetFlowControl *fc = cls;
457 * Send an ACK on the connection, informing the predecessor about
458 * the available buffer space. Should not be called in case the peer
459 * is origin (no predecessor) in the @c fwd direction.
461 * Note that for fwd ack, the FWD mean forward *traffic* (root->dest),
462 * the ACK itself goes "back" (dest->root).
464 * @param c Connection on which to send the ACK.
465 * @param buffer How much space free to advertise?
466 * @param fwd Is this FWD ACK? (Going dest -> root)
467 * @param force Don't optimize out.
470 send_ack (struct CadetConnection *c, unsigned int buffer, int fwd, int force)
472 struct CadetFlowControl *next_fc;
473 struct CadetFlowControl *prev_fc;
474 struct GNUNET_CADET_ACK msg;
478 /* If origin, there is no connection to send ACKs. Wrong function! */
479 if (GCC_is_origin (c, fwd))
481 LOG (GNUNET_ERROR_TYPE_DEBUG, "connection %s is origin in %s\n",
482 GCC_2s (c), GC_f2s (fwd));
487 next_fc = fwd ? &c->fwd_fc : &c->bck_fc;
488 prev_fc = fwd ? &c->bck_fc : &c->fwd_fc;
490 LOG (GNUNET_ERROR_TYPE_DEBUG, "connection send %s ack on %s\n",
491 GC_f2s (fwd), GCC_2s (c));
493 /* Check if we need to transmit the ACK. */
494 delta = prev_fc->last_ack_sent - prev_fc->last_pid_recv;
495 if (3 < delta && buffer < delta && GNUNET_NO == force)
497 LOG (GNUNET_ERROR_TYPE_DEBUG, "Not sending ACK, buffer > 3\n");
498 LOG (GNUNET_ERROR_TYPE_DEBUG,
499 " last pid recv: %u, last ack sent: %u\n",
500 prev_fc->last_pid_recv, prev_fc->last_ack_sent);
504 /* Ok, ACK might be necessary, what PID to ACK? */
505 ack = prev_fc->last_pid_recv + buffer;
506 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK %u\n", ack);
507 LOG (GNUNET_ERROR_TYPE_DEBUG,
508 " last pid %u, last ack %u, qmax %u, q %u\n",
509 prev_fc->last_pid_recv, prev_fc->last_ack_sent,
510 next_fc->queue_max, next_fc->queue_n);
511 if (ack == prev_fc->last_ack_sent && GNUNET_NO == force)
513 LOG (GNUNET_ERROR_TYPE_DEBUG, "Not sending FWD ACK, not needed\n");
517 /* Check if message is already in queue */
518 if (NULL != prev_fc->ack_msg)
520 if (GC_is_pid_bigger (ack, prev_fc->last_ack_sent))
522 LOG (GNUNET_ERROR_TYPE_DEBUG, " canceling old ACK\n");
523 GCC_cancel (prev_fc->ack_msg);
524 /* GCC_cancel triggers ack_sent(), which clears fc->ack_msg */
528 LOG (GNUNET_ERROR_TYPE_DEBUG, " same ACK already in queue\n");
533 prev_fc->last_ack_sent = ack;
535 /* Build ACK message and send on connection */
536 msg.header.size = htons (sizeof (msg));
537 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_ACK);
538 msg.ack = htonl (ack);
541 prev_fc->ack_msg = GCC_send_prebuilt_message (&msg.header, 0, ack, c,
544 GNUNET_assert (NULL != prev_fc->ack_msg);
549 * Callback called when a connection queued message is sent.
551 * Calculates the average time and connection packet tracking.
553 * @param cls Closure (ConnectionQueue Handle).
554 * @param c Connection this message was on.
555 * @param sent Was it really sent? (Could have been canceled)
556 * @param type Type of message sent.
557 * @param pid Packet ID, or 0 if not applicable (create, destroy, etc).
558 * @param fwd Was this a FWD going message?
559 * @param size Size of the message.
560 * @param wait Time spent waiting for core (only the time for THIS message)
563 conn_message_sent (void *cls,
564 struct CadetConnection *c, int sent,
565 uint16_t type, uint32_t pid, int fwd, size_t size,
566 struct GNUNET_TIME_Relative wait)
568 struct CadetConnectionPerformance *p;
569 struct CadetFlowControl *fc;
570 struct CadetConnectionQueue *q = cls;
574 LOG (GNUNET_ERROR_TYPE_DEBUG, "connection message_sent\n");
576 fc = fwd ? &c->fwd_fc : &c->bck_fc;
577 LOG (GNUNET_ERROR_TYPE_DEBUG, " %ssent %s %s\n",
578 sent ? "" : "not ", GC_f2s (fwd), GC_m2s (type));
584 LOG (GNUNET_ERROR_TYPE_DEBUG, " calling cont\n");
585 q->cont (q->cont_cls, c, q, type, fwd, size);
589 else if (type == GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED)
591 /* If NULL == q and ENCRYPTED == type, message must have been ch_mngmnt */
600 if (type != GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN
601 && type != GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY)
603 LOG (GNUNET_ERROR_TYPE_ERROR, "Message %s sent on NULL connection!\n",
608 LOG (GNUNET_ERROR_TYPE_DEBUG, " C_P- %p %u\n", c, c->pending_messages);
609 c->pending_messages--;
610 if (GNUNET_YES == c->destroy && 0 == c->pending_messages)
612 LOG (GNUNET_ERROR_TYPE_DEBUG, "! destroying connection!\n");
616 /* Send ACK if needed, after accounting for sent ID in fc->queue_n */
619 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE:
620 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_ACK:
621 c->maintenance_q = NULL;
622 /* Don't trigger a keepalive for sent ACKs, only SYN and SYNACKs */
623 if (GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE == type || !fwd)
624 schedule_next_keepalive (c, fwd);
627 case GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED:
628 if (GNUNET_YES == sent)
630 GNUNET_assert (NULL != q);
631 fc->last_pid_sent = pid; // FIXME
632 GCC_send_ack (c, fwd, GNUNET_NO);
633 connection_reset_timeout (c, fwd);
636 LOG (GNUNET_ERROR_TYPE_DEBUG, "! Q_N- %p %u\n", fc, fc->queue_n);
637 if (GNUNET_NO == forced)
640 LOG (GNUNET_ERROR_TYPE_DEBUG,
641 "! accounting pid %u\n",
646 LOG (GNUNET_ERROR_TYPE_DEBUG,
647 "! forced, Q_N not accounting pid %u\n",
652 case GNUNET_MESSAGE_TYPE_CADET_KX:
653 if (GNUNET_YES == sent)
654 connection_reset_timeout (c, fwd);
657 case GNUNET_MESSAGE_TYPE_CADET_POLL:
661 case GNUNET_MESSAGE_TYPE_CADET_ACK:
668 LOG (GNUNET_ERROR_TYPE_DEBUG, "! message sent!\n");
671 return; /* Only endpoints are interested in timing. */
674 usecsperbyte = ((double) wait.rel_value_us) / size;
675 if (p->size == AVG_MSGS)
677 /* Array is full. Substract oldest value, add new one and store. */
678 p->avg -= (p->usecsperbyte[p->idx] / AVG_MSGS);
679 p->usecsperbyte[p->idx] = usecsperbyte;
680 p->avg += (p->usecsperbyte[p->idx] / AVG_MSGS);
684 /* Array not yet full. Add current value to avg and store. */
685 p->usecsperbyte[p->idx] = usecsperbyte;
687 p->avg += p->usecsperbyte[p->idx];
691 p->idx = (p->idx + 1) % AVG_MSGS;
696 * Get the previous hop in a connection
698 * @param c Connection.
700 * @return Previous peer in the connection.
702 static struct CadetPeer *
703 get_prev_hop (const struct CadetConnection *c)
707 LOG (GNUNET_ERROR_TYPE_DEBUG, " get prev hop %s [%u/%u]\n",
708 GCC_2s (c), c->own_pos, c->path->length);
709 if (0 == c->own_pos || c->path->length < 2)
710 id = c->path->peers[0];
712 id = c->path->peers[c->own_pos - 1];
714 LOG (GNUNET_ERROR_TYPE_DEBUG, " ID: %s (%u)\n",
715 GNUNET_i2s (GNUNET_PEER_resolve2 (id)), id);
717 return GCP_get_short (id);
722 * Get the next hop in a connection
724 * @param c Connection.
726 * @return Next peer in the connection.
728 static struct CadetPeer *
729 get_next_hop (const struct CadetConnection *c)
733 LOG (GNUNET_ERROR_TYPE_DEBUG, " get next hop %s [%u/%u]\n",
734 GCC_2s (c), c->own_pos, c->path->length);
735 if ((c->path->length - 1) == c->own_pos || c->path->length < 2)
736 id = c->path->peers[c->path->length - 1];
738 id = c->path->peers[c->own_pos + 1];
740 LOG (GNUNET_ERROR_TYPE_DEBUG, " ID: %s (%u)\n",
741 GNUNET_i2s (GNUNET_PEER_resolve2 (id)), id);
743 return GCP_get_short (id);
748 * Get the hop in a connection.
750 * @param c Connection.
751 * @param fwd Next hop?
753 * @return Next peer in the connection.
755 static struct CadetPeer *
756 get_hop (struct CadetConnection *c, int fwd)
759 return get_next_hop (c);
760 return get_prev_hop (c);
765 * Is traffic coming from this sender 'FWD' traffic?
767 * @param c Connection to check.
768 * @param sender Peer identity of neighbor.
770 * @return #GNUNET_YES in case the sender is the 'prev' hop and therefore
771 * the traffic is 'FWD'.
772 * #GNUNET_NO for BCK.
773 * #GNUNET_SYSERR for errors.
776 is_fwd (const struct CadetConnection *c,
777 const struct GNUNET_PeerIdentity *sender)
781 id = GNUNET_PEER_search (sender);
782 if (GCP_get_short_id (get_prev_hop (c)) == id)
785 if (GCP_get_short_id (get_next_hop (c)) == id)
789 return GNUNET_SYSERR;
794 * Sends a CONNECTION ACK message in reponse to a received CONNECTION_CREATE
795 * or a first CONNECTION_ACK directed to us.
797 * @param connection Connection to confirm.
798 * @param fwd Should we send it FWD? (root->dest)
799 * (First (~SYNACK) goes BCK, second (~ACK) goes FWD)
802 send_connection_ack (struct CadetConnection *connection, int fwd)
804 struct CadetTunnel *t;
807 LOG (GNUNET_ERROR_TYPE_INFO, "===> {%14s ACK} on connection %s\n",
808 GC_f2s (!fwd), GCC_2s (connection));
809 GCP_queue_add (get_hop (connection, fwd), NULL,
810 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_ACK, 0, 0,
811 sizeof (struct GNUNET_CADET_ConnectionACK),
812 connection, fwd, &conn_message_sent, NULL);
813 connection->pending_messages++;
814 if (CADET_TUNNEL_NEW == GCT_get_cstate (t))
815 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
816 if (CADET_CONNECTION_READY != connection->state)
817 connection_change_state (connection, CADET_CONNECTION_SENT);
822 * Send a notification that a connection is broken.
824 * @param c Connection that is broken.
825 * @param id1 Peer that has disconnected.
826 * @param id2 Peer that has disconnected.
827 * @param fwd Direction towards which to send it.
830 send_broken (struct CadetConnection *c,
831 const struct GNUNET_PeerIdentity *id1,
832 const struct GNUNET_PeerIdentity *id2,
835 struct GNUNET_CADET_ConnectionBroken msg;
837 msg.header.size = htons (sizeof (struct GNUNET_CADET_ConnectionBroken));
838 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN);
842 GNUNET_assert (NULL == GCC_send_prebuilt_message (&msg.header, 0, 0, c, fwd,
843 GNUNET_YES, NULL, NULL));
848 * Send a notification that a connection is broken, when a connection
849 * isn't even known to the local peer.
851 * @param connection_id Connection ID.
852 * @param id1 Peer that has disconnected, probably local peer.
853 * @param id2 Peer that has disconnected can be NULL if unknown.
854 * @param peer Peer to notify (neighbor who sent the connection).
857 send_broken_unknown (const struct GNUNET_CADET_Hash *connection_id,
858 const struct GNUNET_PeerIdentity *id1,
859 const struct GNUNET_PeerIdentity *id2,
860 const struct GNUNET_PeerIdentity *peer_id)
862 struct GNUNET_CADET_ConnectionBroken *msg;
863 struct CadetPeer *neighbor;
865 LOG (GNUNET_ERROR_TYPE_INFO, "===> BROKEN on unknown connection %s\n",
866 GNUNET_h2s (GC_h2hc (connection_id)));
868 msg = GNUNET_new (struct GNUNET_CADET_ConnectionBroken);
869 msg->header.size = htons (sizeof (struct GNUNET_CADET_ConnectionBroken));
870 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN);
871 msg->cid = *connection_id;
876 memset (&msg->peer2, 0, sizeof (msg->peer2));
877 neighbor = GCP_get (peer_id);
878 GCP_queue_add (neighbor, msg, GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN,
879 0, 2, sizeof (struct GNUNET_CADET_ConnectionBroken),
880 NULL, GNUNET_SYSERR, /* connection, fwd */
881 NULL, NULL); /* continuation */
886 * Send keepalive packets for a connection.
888 * @param c Connection to keep alive..
889 * @param fwd Is this a FWD keepalive? (owner -> dest).
892 send_connection_keepalive (struct CadetConnection *c, int fwd)
894 struct GNUNET_MessageHeader msg;
895 struct CadetFlowControl *fc;
897 LOG (GNUNET_ERROR_TYPE_INFO,
898 "keepalive %s for connection %s\n",
899 GC_f2s (fwd), GCC_2s (c));
901 fc = fwd ? &c->fwd_fc : &c->bck_fc;
904 LOG (GNUNET_ERROR_TYPE_INFO, "not sending keepalive, traffic in queue\n");
907 GNUNET_STATISTICS_update (stats, "# keepalives sent", 1, GNUNET_NO);
909 GNUNET_assert (NULL != c->t);
910 msg.size = htons (sizeof (msg));
911 msg.type = htons (GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE);
913 GNUNET_assert (NULL ==
914 GCT_send_prebuilt_message (&msg, c->t, c,
915 GNUNET_NO, NULL, NULL));
920 * Send CONNECTION_{CREATE/ACK} packets for a connection.
922 * @param c Connection for which to send the message.
923 * @param fwd If #GNUNET_YES, send CREATE, otherwise send ACK.
926 connection_recreate (struct CadetConnection *c, int fwd)
928 LOG (GNUNET_ERROR_TYPE_DEBUG, "sending connection recreate\n");
932 send_connection_ack (c, GNUNET_NO);
937 * Generic connection timer management.
938 * Depending on the role of the peer in the connection will send the
939 * appropriate message (build or keepalive)
941 * @param c Conncetion to maintain.
945 connection_maintain (struct CadetConnection *c, int fwd)
947 if (GNUNET_NO != c->destroy)
950 if (CADET_TUNNEL_SEARCHING == GCT_get_cstate (c->t))
952 /* TODO DHT GET with RO_BART */
957 case CADET_CONNECTION_NEW:
960 case CADET_CONNECTION_SENT:
961 connection_recreate (c, fwd);
963 case CADET_CONNECTION_READY:
964 send_connection_keepalive (c, fwd);
974 * Keep the connection alive.
976 * @param c Connection to keep alive.
977 * @param fwd Direction.
978 * @param shutdown Are we shutting down? (Don't send traffic)
979 * Non-zero value for true, not necessarily GNUNET_YES.
982 connection_keepalive (struct CadetConnection *c, int fwd, int shutdown)
984 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s keepalive for %s\n",
985 GC_f2s (fwd), GCC_2s (c));
988 c->fwd_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
990 c->bck_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
992 if (GNUNET_NO != shutdown)
995 connection_maintain (c, fwd);
997 /* Next execution will be scheduled by message_sent */
1002 * Keep the connection alive in the FWD direction.
1004 * @param cls Closure (connection to keepalive).
1005 * @param tc TaskContext.
1008 connection_fwd_keepalive (void *cls,
1009 const struct GNUNET_SCHEDULER_TaskContext *tc)
1011 connection_keepalive ((struct CadetConnection *) cls,
1013 tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN);
1018 * Keep the connection alive in the BCK direction.
1020 * @param cls Closure (connection to keepalive).
1021 * @param tc TaskContext.
1024 connection_bck_keepalive (void *cls,
1025 const struct GNUNET_SCHEDULER_TaskContext *tc)
1027 connection_keepalive ((struct CadetConnection *) cls,
1029 tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN);
1034 * Schedule next keepalive task, taking in consideration
1035 * the connection state and number of retries.
1037 * If the peer is not the origin, do nothing.
1039 * @param c Connection for which to schedule the next keepalive.
1040 * @param fwd Direction for the next keepalive.
1043 schedule_next_keepalive (struct CadetConnection *c, int fwd)
1045 struct GNUNET_TIME_Relative delay;
1046 GNUNET_SCHEDULER_TaskIdentifier *task_id;
1047 GNUNET_SCHEDULER_Task keepalive_task;
1049 if (GNUNET_NO == GCC_is_origin (c, fwd))
1052 /* Calculate delay to use, depending on the state of the connection */
1053 if (CADET_CONNECTION_READY == c->state)
1055 delay = refresh_connection_time;
1059 if (1 > c->create_retry)
1060 c->create_retry = 1;
1061 delay = GNUNET_TIME_relative_multiply (create_connection_time,
1063 if (c->create_retry < 64)
1064 c->create_retry *= 2;
1067 /* Select direction-dependent parameters */
1068 if (GNUNET_YES == fwd)
1070 task_id = &c->fwd_maintenance_task;
1071 keepalive_task = &connection_fwd_keepalive;
1075 task_id = &c->bck_maintenance_task;
1076 keepalive_task = &connection_bck_keepalive;
1079 /* Check that no one scheduled it before us */
1080 if (GNUNET_SCHEDULER_NO_TASK != *task_id)
1082 /* No need for a _break. It can happen for instance when sending a SYNACK
1083 * for a duplicate SYN: the first SYNACK scheduled the task. */
1084 GNUNET_SCHEDULER_cancel (*task_id);
1087 /* Schedule the task */
1088 *task_id = GNUNET_SCHEDULER_add_delayed (delay, keepalive_task, c);
1089 LOG (GNUNET_ERROR_TYPE_DEBUG, "next keepalive in %s\n",
1090 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
1095 * @brief Re-initiate traffic on this connection if necessary.
1097 * Check if there is traffic queued towards this peer
1098 * and the core transmit handle is NULL (traffic was stalled).
1099 * If so, call core tmt rdy.
1101 * @param c Connection on which initiate traffic.
1102 * @param fwd Is this about fwd traffic?
1105 connection_unlock_queue (struct CadetConnection *c, int fwd)
1107 struct CadetPeer *peer;
1109 LOG (GNUNET_ERROR_TYPE_DEBUG,
1110 "connection_unlock_queue %s on %s\n",
1111 GC_f2s (fwd), GCC_2s (c));
1113 if (GCC_is_terminal (c, fwd))
1115 LOG (GNUNET_ERROR_TYPE_DEBUG, " is terminal!\n");
1119 peer = get_hop (c, fwd);
1120 GCP_queue_unlock (peer, c);
1125 * Cancel all transmissions that belong to a certain connection.
1127 * If the connection is scheduled for destruction and no more messages are left,
1128 * the connection will be destroyed by the continuation call.
1130 * @param c Connection which to cancel. Might be destroyed during this call.
1131 * @param fwd Cancel fwd traffic?
1134 connection_cancel_queues (struct CadetConnection *c, int fwd)
1136 struct CadetFlowControl *fc;
1137 struct CadetPeer *peer;
1139 LOG (GNUNET_ERROR_TYPE_DEBUG,
1140 " *** Cancel %s queues for connection %s\n",
1141 GC_f2s (fwd), GCC_2s (c));
1148 fc = fwd ? &c->fwd_fc : &c->bck_fc;
1149 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task)
1151 GNUNET_SCHEDULER_cancel (fc->poll_task);
1152 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
1153 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** Cancel POLL in ccq for fc %p\n", fc);
1155 peer = get_hop (c, fwd);
1156 GCP_queue_cancel (peer, c);
1161 * Function called if a connection has been stalled for a while,
1162 * possibly due to a missed ACK. Poll the neighbor about its ACK status.
1164 * @param cls Closure (poll ctx).
1165 * @param tc TaskContext.
1168 connection_poll (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
1172 * Callback called when a queued POLL message is sent.
1174 * @param cls Closure (FC).
1175 * @param c Connection this message was on.
1176 * @param q Queue handler this call invalidates.
1177 * @param type Type of message sent.
1178 * @param fwd Was this a FWD going message?
1179 * @param size Size of the message.
1182 poll_sent (void *cls,
1183 struct CadetConnection *c,
1184 struct CadetConnectionQueue *q,
1185 uint16_t type, int fwd, size_t size)
1187 struct CadetFlowControl *fc = cls;
1189 if (2 == c->destroy)
1191 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL canceled on shutdown\n");
1194 LOG (GNUNET_ERROR_TYPE_DEBUG,
1195 " *** POLL sent for , scheduling new one!\n");
1196 fc->poll_msg = NULL;
1197 fc->poll_time = GNUNET_TIME_STD_BACKOFF (fc->poll_time);
1198 fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time,
1199 &connection_poll, fc);
1200 LOG (GNUNET_ERROR_TYPE_DEBUG, " task %u\n", fc->poll_task);
1205 * Function called if a connection has been stalled for a while,
1206 * possibly due to a missed ACK. Poll the neighbor about its ACK status.
1208 * @param cls Closure (poll ctx).
1209 * @param tc TaskContext.
1212 connection_poll (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1214 struct CadetFlowControl *fc = cls;
1215 struct GNUNET_CADET_Poll msg;
1216 struct CadetConnection *c;
1218 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
1219 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1225 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** Polling connection %s %s\n",
1226 GCC_2s (c), fc == &c->fwd_fc ? "FWD" : "BCK");
1228 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_POLL);
1229 msg.header.size = htons (sizeof (msg));
1230 msg.pid = htonl (fc->last_pid_sent);
1231 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** last pid sent: %u!\n", fc->last_pid_sent);
1233 GCC_send_prebuilt_message (&msg.header, 0, fc->last_pid_sent, c,
1234 fc == &c->fwd_fc, GNUNET_YES, &poll_sent, fc);
1235 GNUNET_assert (NULL != fc->poll_msg);
1240 * Timeout function due to lack of keepalive/traffic from the owner.
1241 * Destroys connection if called.
1243 * @param cls Closure (connection to destroy).
1244 * @param tc TaskContext.
1247 connection_fwd_timeout (void *cls,
1248 const struct GNUNET_SCHEDULER_TaskContext *tc)
1250 struct CadetConnection *c = cls;
1252 c->fwd_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
1253 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1256 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s FWD timed out. Destroying.\n",
1258 if (GCC_is_origin (c, GNUNET_YES)) /* If local, leave. */
1269 * Timeout function due to lack of keepalive/traffic from the destination.
1270 * Destroys connection if called.
1272 * @param cls Closure (connection to destroy).
1273 * @param tc TaskContext
1276 connection_bck_timeout (void *cls,
1277 const struct GNUNET_SCHEDULER_TaskContext *tc)
1279 struct CadetConnection *c = cls;
1281 c->bck_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
1282 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1285 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s BCK timed out. Destroying.\n",
1288 if (GCC_is_origin (c, GNUNET_NO)) /* If local, leave. */
1299 * Resets the connection timeout task, some other message has done the
1301 * - For the first peer on the direction this means to send
1302 * a keepalive or a path confirmation message (either create or ACK).
1303 * - For all other peers, this means to destroy the connection,
1304 * due to lack of activity.
1305 * Starts the timeout if no timeout was running (connection just created).
1307 * @param c Connection whose timeout to reset.
1308 * @param fwd Is this forward?
1310 * TODO use heap to improve efficiency of scheduler.
1313 connection_reset_timeout (struct CadetConnection *c, int fwd)
1315 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s reset timeout\n", GC_f2s (fwd));
1317 if (GCC_is_origin (c, fwd)) /* Startpoint */
1319 schedule_next_keepalive (c, fwd);
1321 else /* Relay, endpoint. */
1323 struct GNUNET_TIME_Relative delay;
1324 GNUNET_SCHEDULER_TaskIdentifier *ti;
1325 GNUNET_SCHEDULER_Task f;
1327 ti = fwd ? &c->fwd_maintenance_task : &c->bck_maintenance_task;
1329 if (GNUNET_SCHEDULER_NO_TASK != *ti)
1330 GNUNET_SCHEDULER_cancel (*ti);
1331 delay = GNUNET_TIME_relative_multiply (refresh_connection_time, 4);
1332 f = fwd ? &connection_fwd_timeout : &connection_bck_timeout;
1333 *ti = GNUNET_SCHEDULER_add_delayed (delay, f, c);
1339 * Add the connection to the list of both neighbors.
1341 * @param c Connection.
1343 * @return #GNUNET_OK if everything went fine
1344 * #GNUNET_SYSERR if the was an error and @c c is malformed.
1347 register_neighbors (struct CadetConnection *c)
1349 struct CadetPeer *next_peer;
1350 struct CadetPeer *prev_peer;
1352 next_peer = get_next_hop (c);
1353 prev_peer = get_prev_hop (c);
1355 LOG (GNUNET_ERROR_TYPE_DEBUG, "register neighbors for connection %s\n",
1357 path_debug (c->path);
1358 LOG (GNUNET_ERROR_TYPE_DEBUG, "own pos %u\n", c->own_pos);
1359 LOG (GNUNET_ERROR_TYPE_DEBUG, "putting connection %s to next peer %p\n",
1360 GCC_2s (c), next_peer);
1361 LOG (GNUNET_ERROR_TYPE_DEBUG, "next peer %p %s\n", next_peer, GCP_2s (next_peer));
1362 LOG (GNUNET_ERROR_TYPE_DEBUG, "putting connection %s to prev peer %p\n",
1363 GCC_2s (c), prev_peer);
1364 LOG (GNUNET_ERROR_TYPE_DEBUG, "prev peer %p %s\n", prev_peer, GCP_2s (prev_peer));
1366 if (GNUNET_NO == GCP_is_neighbor (next_peer)
1367 || GNUNET_NO == GCP_is_neighbor (prev_peer))
1369 if (GCC_is_origin (c, GNUNET_YES))
1370 GNUNET_STATISTICS_update (stats, "# local bad paths", 1, GNUNET_NO);
1371 GNUNET_STATISTICS_update (stats, "# bad paths", 1, GNUNET_NO);
1373 LOG (GNUNET_ERROR_TYPE_DEBUG, " register neighbors failed\n");
1374 LOG (GNUNET_ERROR_TYPE_DEBUG, " prev: %s, neighbor?: %d\n",
1375 GCP_2s (prev_peer), GCP_is_neighbor (prev_peer));
1376 LOG (GNUNET_ERROR_TYPE_DEBUG, " next: %s, neighbor?: %d\n",
1377 GCP_2s (next_peer), GCP_is_neighbor (next_peer));
1378 return GNUNET_SYSERR;
1381 GCP_add_connection (next_peer, c);
1382 GCP_add_connection (prev_peer, c);
1389 * Remove the connection from the list of both neighbors.
1391 * @param c Connection.
1394 unregister_neighbors (struct CadetConnection *c)
1396 struct CadetPeer *peer;
1398 peer = get_next_hop (c);
1399 if (GNUNET_OK != GCP_remove_connection (peer, c))
1401 GNUNET_assert (CADET_CONNECTION_NEW == c->state
1402 || CADET_CONNECTION_DESTROYED == c->state);
1403 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate: %u\n", c->state);
1404 if (NULL != c->t) GCT_debug (c->t, GNUNET_ERROR_TYPE_DEBUG);
1407 peer = get_prev_hop (c);
1408 if (GNUNET_OK != GCP_remove_connection (peer, c))
1410 GNUNET_assert (CADET_CONNECTION_NEW == c->state
1411 || CADET_CONNECTION_DESTROYED == c->state);
1412 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate: %u\n", c->state);
1413 if (NULL != c->t) GCT_debug (c->t, GNUNET_ERROR_TYPE_DEBUG);
1419 * Bind the connection to the peer and the tunnel to that peer.
1421 * If the peer has no tunnel, create one. Update tunnel and connection
1422 * data structres to reflect new status.
1424 * @param c Connection.
1428 add_to_peer (struct CadetConnection *c, struct CadetPeer *peer)
1430 GCP_add_tunnel (peer);
1431 c->t = GCP_get_tunnel (peer);
1432 GCT_add_connection (c->t, c);
1437 * Builds a path from a PeerIdentity array.
1439 * @param peers PeerIdentity array.
1440 * @param size Size of the @c peers array.
1441 * @param own_pos Output parameter: own position in the path.
1443 * @return Fixed and shortened path.
1445 static struct CadetPeerPath *
1446 build_path_from_peer_ids (struct GNUNET_PeerIdentity *peers,
1448 unsigned int *own_pos)
1450 struct CadetPeerPath *path;
1451 GNUNET_PEER_Id shortid;
1454 unsigned int offset;
1457 LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating path...\n");
1458 path = path_new (size);
1461 for (i = 0; i < size; i++)
1463 LOG (GNUNET_ERROR_TYPE_DEBUG, " - %u: taking %s\n",
1464 i, GNUNET_i2s (&peers[i]));
1465 shortid = GNUNET_PEER_intern (&peers[i]);
1467 /* Check for loops / duplicates */
1468 for (j = 0; j < i - offset; j++)
1470 if (path->peers[j] == shortid)
1472 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists at pos %u\n", j);
1474 LOG (GNUNET_ERROR_TYPE_DEBUG, " offset now %u\n", offset);
1475 GNUNET_PEER_change_rc (shortid, -1);
1478 LOG (GNUNET_ERROR_TYPE_DEBUG, " storing at %u\n", i - offset);
1479 path->peers[i - offset] = shortid;
1480 if (path->peers[i - offset] == myid)
1481 *own_pos = i - offset;
1483 path->length -= offset;
1485 if (path->peers[*own_pos] != myid)
1487 /* create path: self not found in path through self */
1488 GNUNET_break_op (0);
1489 path_destroy (path);
1498 * Log receipt of message on stderr (INFO level).
1500 * @param message Message received.
1501 * @param peer Peer who sent the message.
1502 * @param hash Connection ID.
1505 log_message (const struct GNUNET_MessageHeader *message,
1506 const struct GNUNET_PeerIdentity *peer,
1507 const struct GNUNET_CADET_Hash *hash)
1509 LOG (GNUNET_ERROR_TYPE_INFO, "<-- %s on connection %s from %s\n",
1510 GC_m2s (ntohs (message->type)), GNUNET_h2s (GC_h2hc (hash)),
1514 /******************************************************************************/
1515 /******************************** API ***********************************/
1516 /******************************************************************************/
1519 * Core handler for connection creation.
1521 * @param cls Closure (unused).
1522 * @param peer Sender (neighbor).
1523 * @param message Message.
1525 * @return GNUNET_OK to keep the connection open,
1526 * GNUNET_SYSERR to close it (signal serious error)
1529 GCC_handle_create (void *cls, const struct GNUNET_PeerIdentity *peer,
1530 const struct GNUNET_MessageHeader *message)
1532 struct GNUNET_CADET_ConnectionCreate *msg;
1533 struct GNUNET_PeerIdentity *id;
1534 struct GNUNET_CADET_Hash *cid;
1535 struct CadetPeerPath *path;
1536 struct CadetPeer *dest_peer;
1537 struct CadetPeer *orig_peer;
1538 struct CadetConnection *c;
1539 unsigned int own_pos;
1543 size = ntohs (message->size);
1544 if (size < sizeof (struct GNUNET_CADET_ConnectionCreate))
1546 GNUNET_break_op (0);
1550 /* Calculate hops */
1551 size -= sizeof (struct GNUNET_CADET_ConnectionCreate);
1552 if (size % sizeof (struct GNUNET_PeerIdentity))
1554 GNUNET_break_op (0);
1557 size /= sizeof (struct GNUNET_PeerIdentity);
1560 GNUNET_break_op (0);
1563 LOG (GNUNET_ERROR_TYPE_DEBUG, " path has %u hops.\n", size);
1565 /* Get parameters */
1566 msg = (struct GNUNET_CADET_ConnectionCreate *) message;
1568 log_message (message, peer, cid);
1569 id = (struct GNUNET_PeerIdentity *) &msg[1];
1570 LOG (GNUNET_ERROR_TYPE_DEBUG, " origin: %s\n", GNUNET_i2s (id));
1572 /* Create connection */
1573 c = connection_get (cid);
1576 path = build_path_from_peer_ids ((struct GNUNET_PeerIdentity *) &msg[1],
1582 GNUNET_break_op (0);
1583 path_destroy (path);
1586 LOG (GNUNET_ERROR_TYPE_DEBUG, " Own position: %u\n", own_pos);
1587 LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating connection\n");
1588 c = GCC_new (cid, NULL, path_duplicate (path), own_pos);
1591 if (path->length - 1 == own_pos)
1593 /* If we are destination, why did the creation fail? */
1597 send_broken_unknown (cid, &my_full_id,
1598 GNUNET_PEER_resolve2 (path->peers[own_pos + 1]),
1600 path_destroy (path);
1603 GCP_add_path_to_all (path, GNUNET_NO);
1604 connection_reset_timeout (c, GNUNET_YES);
1608 path = path_duplicate (c->path);
1610 if (CADET_CONNECTION_NEW == c->state)
1611 connection_change_state (c, CADET_CONNECTION_SENT);
1613 /* Remember peers */
1614 dest_peer = GCP_get (&id[size - 1]);
1615 orig_peer = GCP_get (&id[0]);
1617 /* Is it a connection to us? */
1618 if (c->own_pos == path->length - 1)
1620 LOG (GNUNET_ERROR_TYPE_DEBUG, " It's for us!\n");
1621 GCP_add_path_to_origin (orig_peer, path_duplicate (path), GNUNET_YES);
1623 add_to_peer (c, orig_peer);
1624 if (CADET_TUNNEL_NEW == GCT_get_cstate (c->t))
1625 GCT_change_cstate (c->t, CADET_TUNNEL_WAITING);
1627 send_connection_ack (c, GNUNET_NO);
1628 if (CADET_CONNECTION_SENT == c->state)
1629 connection_change_state (c, CADET_CONNECTION_ACK);
1633 /* It's for somebody else! Retransmit. */
1634 LOG (GNUNET_ERROR_TYPE_DEBUG, " Retransmitting.\n");
1635 GCP_add_path (dest_peer, path_duplicate (path), GNUNET_NO);
1636 GCP_add_path_to_origin (orig_peer, path_duplicate (path), GNUNET_NO);
1637 GNUNET_assert (NULL == GCC_send_prebuilt_message (message, 0, 0, c,
1638 GNUNET_YES, GNUNET_YES,
1641 path_destroy (path);
1647 * Core handler for path confirmations.
1649 * @param cls closure
1650 * @param message message
1651 * @param peer peer identity this notification is about
1653 * @return GNUNET_OK to keep the connection open,
1654 * GNUNET_SYSERR to close it (signal serious error)
1657 GCC_handle_confirm (void *cls, const struct GNUNET_PeerIdentity *peer,
1658 const struct GNUNET_MessageHeader *message)
1660 struct GNUNET_CADET_ConnectionACK *msg;
1661 struct CadetConnection *c;
1662 struct CadetPeerPath *p;
1663 struct CadetPeer *pi;
1664 enum CadetConnectionState oldstate;
1667 msg = (struct GNUNET_CADET_ConnectionACK *) message;
1668 log_message (message, peer, &msg->cid);
1669 c = connection_get (&msg->cid);
1672 GNUNET_STATISTICS_update (stats, "# control on unknown connection",
1674 LOG (GNUNET_ERROR_TYPE_DEBUG, " don't know the connection!\n");
1675 send_broken_unknown (&msg->cid, &my_full_id, NULL, peer);
1679 if (GNUNET_NO != c->destroy)
1681 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection being destroyed\n");
1685 oldstate = c->state;
1686 LOG (GNUNET_ERROR_TYPE_DEBUG, " via peer %s\n", GNUNET_i2s (peer));
1687 pi = GCP_get (peer);
1688 if (get_next_hop (c) == pi)
1690 LOG (GNUNET_ERROR_TYPE_DEBUG, " SYNACK\n");
1692 if (CADET_CONNECTION_SENT == oldstate)
1693 connection_change_state (c, CADET_CONNECTION_ACK);
1695 else if (get_prev_hop (c) == pi)
1697 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK\n");
1699 connection_change_state (c, CADET_CONNECTION_READY);
1703 GNUNET_break_op (0);
1707 connection_reset_timeout (c, fwd);
1709 /* Add path to peers? */
1713 GCP_add_path_to_all (p, GNUNET_YES);
1720 /* Message for us as creator? */
1721 if (GCC_is_origin (c, GNUNET_YES))
1723 if (GNUNET_NO != fwd)
1725 GNUNET_break_op (0);
1728 LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection (SYN)ACK for us!\n");
1730 /* If just created, cancel the short timeout and start a long one */
1731 if (CADET_CONNECTION_SENT == oldstate)
1732 connection_reset_timeout (c, GNUNET_YES);
1734 /* Change connection state */
1735 connection_change_state (c, CADET_CONNECTION_READY);
1736 send_connection_ack (c, GNUNET_YES);
1738 /* Change tunnel state, trigger KX */
1739 if (CADET_TUNNEL_WAITING == GCT_get_cstate (c->t))
1740 GCT_change_cstate (c->t, CADET_TUNNEL_READY);
1745 /* Message for us as destination? */
1746 if (GCC_is_terminal (c, GNUNET_YES))
1748 if (GNUNET_YES != fwd)
1750 GNUNET_break_op (0);
1753 LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection ACK for us!\n");
1755 /* If just created, cancel the short timeout and start a long one */
1756 if (CADET_CONNECTION_ACK == oldstate)
1757 connection_reset_timeout (c, GNUNET_NO);
1759 /* Change tunnel state */
1760 if (CADET_TUNNEL_WAITING == GCT_get_cstate (c->t))
1761 GCT_change_cstate (c->t, CADET_TUNNEL_READY);
1766 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
1767 GNUNET_assert (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
1768 GNUNET_YES, NULL, NULL));
1774 * Core handler for notifications of broken connections.
1776 * @param cls Closure (unused).
1777 * @param id Peer identity of sending neighbor.
1778 * @param message Message.
1780 * @return GNUNET_OK to keep the connection open,
1781 * GNUNET_SYSERR to close it (signal serious error)
1784 GCC_handle_broken (void* cls,
1785 const struct GNUNET_PeerIdentity* id,
1786 const struct GNUNET_MessageHeader* message)
1788 struct GNUNET_CADET_ConnectionBroken *msg;
1789 struct CadetConnection *c;
1790 struct CadetTunnel *t;
1793 msg = (struct GNUNET_CADET_ConnectionBroken *) message;
1794 log_message (message, id, &msg->cid);
1795 LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n",
1796 GNUNET_i2s (&msg->peer1));
1797 LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n",
1798 GNUNET_i2s (&msg->peer2));
1799 c = connection_get (&msg->cid);
1802 LOG (GNUNET_ERROR_TYPE_DEBUG, " duplicate CONNECTION_BROKEN\n");
1806 fwd = is_fwd (c, id);
1807 if (GCC_is_terminal (c, fwd))
1809 struct GNUNET_MessageHeader *out_msg;
1810 struct CadetPeer *neighbor;
1811 struct CadetPeer *endpoint;
1813 neighbor = get_hop (c, !fwd);
1814 endpoint = GCP_get_short (c->path->peers[c->path->length - 1]);
1815 path_invalidate (c->path);
1816 GCP_notify_broken_link (endpoint, &msg->peer1, &msg->peer2);
1817 c->state = CADET_CONNECTION_DESTROYED;
1819 while (NULL != (out_msg = GCP_connection_pop (neighbor, c)))
1821 GNUNET_assert (NULL ==
1822 GCT_send_prebuilt_message (out_msg, t, NULL, GNUNET_YES,
1830 GNUNET_assert (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
1831 GNUNET_YES, NULL, NULL));
1832 c->destroy = GNUNET_YES;
1833 connection_cancel_queues (c, !fwd);
1842 * Core handler for tunnel destruction
1844 * @param cls Closure (unused).
1845 * @param peer Peer identity of sending neighbor.
1846 * @param message Message.
1848 * @return GNUNET_OK to keep the connection open,
1849 * GNUNET_SYSERR to close it (signal serious error)
1852 GCC_handle_destroy (void *cls, const struct GNUNET_PeerIdentity *peer,
1853 const struct GNUNET_MessageHeader *message)
1855 struct GNUNET_CADET_ConnectionDestroy *msg;
1856 struct CadetConnection *c;
1859 msg = (struct GNUNET_CADET_ConnectionDestroy *) message;
1860 log_message (message, peer, &msg->cid);
1861 c = connection_get (&msg->cid);
1864 /* Probably already got the message from another path,
1865 * destroyed the tunnel and retransmitted to children.
1868 GNUNET_STATISTICS_update (stats, "# control on unknown connection",
1870 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection unknown: already destroyed?\n");
1873 fwd = is_fwd (c, peer);
1874 if (GNUNET_SYSERR == fwd)
1876 GNUNET_break_op (0); /* FIXME */
1879 if (GNUNET_NO == GCC_is_terminal (c, fwd))
1880 GNUNET_assert (NULL == GCC_send_prebuilt_message (message, 0, 0, c, fwd,
1881 GNUNET_YES, NULL, NULL));
1882 else if (0 == c->pending_messages)
1884 LOG (GNUNET_ERROR_TYPE_DEBUG, " directly destroying connection!\n");
1888 c->destroy = GNUNET_YES;
1889 c->state = CADET_CONNECTION_DESTROYED;
1892 GCT_remove_connection (c->t, c);
1900 * Generic handler for cadet network encrypted traffic.
1902 * @param peer Peer identity this notification is about.
1903 * @param msg Encrypted message.
1905 * @return GNUNET_OK to keep the connection open,
1906 * GNUNET_SYSERR to close it (signal serious error)
1909 handle_cadet_encrypted (const struct GNUNET_PeerIdentity *peer,
1910 const struct GNUNET_CADET_Encrypted *msg)
1912 struct CadetConnection *c;
1913 struct CadetPeer *neighbor;
1914 struct CadetFlowControl *fc;
1915 GNUNET_PEER_Id peer_id;
1921 log_message (&msg->header, peer, &msg->cid);
1924 size = ntohs (msg->header.size);
1926 sizeof (struct GNUNET_CADET_Encrypted) +
1927 sizeof (struct GNUNET_MessageHeader))
1929 GNUNET_break_op (0);
1933 /* Check connection */
1934 c = connection_get (&msg->cid);
1937 GNUNET_STATISTICS_update (stats, "# unknown connection", 1, GNUNET_NO);
1938 LOG (GNUNET_ERROR_TYPE_DEBUG, "enc on unknown connection %s\n",
1939 GNUNET_h2s (GC_h2hc (&msg->cid)));
1940 send_broken_unknown (&msg->cid, &my_full_id, NULL, peer);
1944 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s\n", GCC_2s (c));
1946 /* Check if origin is as expected */
1947 neighbor = get_prev_hop (c);
1948 peer_id = GNUNET_PEER_search (peer);
1949 if (peer_id == GCP_get_short_id (neighbor))
1955 neighbor = get_next_hop (c);
1956 if (peer_id == GCP_get_short_id (neighbor))
1962 /* Unexpected peer sending traffic on a connection. */
1963 GNUNET_break_op (0);
1969 fc = fwd ? &c->bck_fc : &c->fwd_fc;
1970 pid = ntohl (msg->pid);
1971 LOG (GNUNET_ERROR_TYPE_DEBUG, " PID %u (expected %u+)\n",
1972 pid, fc->last_pid_recv + 1);
1973 if (GC_is_pid_bigger (pid, fc->last_ack_sent))
1975 GNUNET_STATISTICS_update (stats, "# unsolicited message", 1, GNUNET_NO);
1976 GNUNET_break_op (0);
1977 LOG (GNUNET_ERROR_TYPE_WARNING,
1978 "Received PID %u, (prev %u), ACK %u\n",
1979 pid, fc->last_pid_recv, fc->last_ack_sent);
1982 if (GNUNET_NO == GC_is_pid_bigger (pid, fc->last_pid_recv))
1984 GNUNET_STATISTICS_update (stats, "# duplicate PID", 1, GNUNET_NO);
1985 LOG (GNUNET_ERROR_TYPE_DEBUG,
1986 " PID %u not expected (%u+), dropping!\n",
1987 pid, fc->last_pid_recv + 1);
1990 if (CADET_CONNECTION_SENT == c->state || CADET_CONNECTION_ACK == c->state)
1991 connection_change_state (c, CADET_CONNECTION_READY);
1992 connection_reset_timeout (c, fwd);
1993 fc->last_pid_recv = pid;
1995 /* Is this message for us? */
1996 if (GCC_is_terminal (c, fwd))
1998 LOG (GNUNET_ERROR_TYPE_DEBUG, " message for us!\n");
1999 GNUNET_STATISTICS_update (stats, "# messages received", 1, GNUNET_NO);
2003 GNUNET_break (GNUNET_NO != c->destroy);
2006 fc->last_pid_recv = pid;
2007 GCT_handle_encrypted (c->t, msg);
2008 GCC_send_ack (c, fwd, GNUNET_NO);
2012 /* Message not for us: forward to next hop */
2013 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
2014 ttl = ntohl (msg->ttl);
2015 LOG (GNUNET_ERROR_TYPE_DEBUG, " ttl: %u\n", ttl);
2018 GNUNET_STATISTICS_update (stats, "# TTL drops", 1, GNUNET_NO);
2019 LOG (GNUNET_ERROR_TYPE_WARNING, " TTL is 0, DROPPING!\n");
2020 GCC_send_ack (c, fwd, GNUNET_NO);
2024 GNUNET_STATISTICS_update (stats, "# messages forwarded", 1, GNUNET_NO);
2025 GNUNET_assert (NULL == GCC_send_prebuilt_message (&msg->header, 0, 0, c, fwd,
2026 GNUNET_NO, NULL, NULL));
2032 * Generic handler for cadet network encrypted traffic.
2034 * @param peer Peer identity this notification is about.
2035 * @param msg Encrypted message.
2037 * @return GNUNET_OK to keep the connection open,
2038 * GNUNET_SYSERR to close it (signal serious error)
2041 handle_cadet_kx (const struct GNUNET_PeerIdentity *peer,
2042 const struct GNUNET_CADET_KX *msg)
2044 struct CadetConnection *c;
2045 struct CadetPeer *neighbor;
2046 GNUNET_PEER_Id peer_id;
2050 log_message (&msg->header, peer, &msg->cid);
2053 size = ntohs (msg->header.size);
2055 sizeof (struct GNUNET_CADET_KX) +
2056 sizeof (struct GNUNET_MessageHeader))
2058 GNUNET_break_op (0);
2062 /* Check connection */
2063 c = connection_get (&msg->cid);
2066 GNUNET_STATISTICS_update (stats, "# unknown connection", 1, GNUNET_NO);
2067 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx on unknown connection %s\n",
2068 GNUNET_h2s (GC_h2hc (&msg->cid)));
2069 send_broken_unknown (&msg->cid, &my_full_id, NULL, peer);
2072 LOG (GNUNET_ERROR_TYPE_DEBUG, " on connection %s\n", GCC_2s (c));
2074 /* Check if origin is as expected */
2075 neighbor = get_prev_hop (c);
2076 peer_id = GNUNET_PEER_search (peer);
2077 if (peer_id == GCP_get_short_id (neighbor))
2083 neighbor = get_next_hop (c);
2084 if (peer_id == GCP_get_short_id (neighbor))
2090 /* Unexpected peer sending traffic on a connection. */
2091 GNUNET_break_op (0);
2096 /* Count as connection confirmation. */
2097 if (CADET_CONNECTION_SENT == c->state || CADET_CONNECTION_ACK == c->state)
2099 connection_change_state (c, CADET_CONNECTION_READY);
2102 if (CADET_TUNNEL_WAITING == GCT_get_cstate (c->t))
2103 GCT_change_cstate (c->t, CADET_TUNNEL_READY);
2106 connection_reset_timeout (c, fwd);
2108 /* Is this message for us? */
2109 if (GCC_is_terminal (c, fwd))
2111 LOG (GNUNET_ERROR_TYPE_DEBUG, " message for us!\n");
2112 GNUNET_STATISTICS_update (stats, "# messages received", 1, GNUNET_NO);
2118 GCT_handle_kx (c->t, &msg[1].header);
2122 /* Message not for us: forward to next hop */
2123 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
2124 GNUNET_STATISTICS_update (stats, "# messages forwarded", 1, GNUNET_NO);
2125 GNUNET_assert (NULL == GCC_send_prebuilt_message (&msg->header, 0, 0, c, fwd,
2126 GNUNET_NO, NULL, NULL));
2133 * Core handler for encrypted cadet network traffic (channel mgmt, data).
2135 * @param cls Closure (unused).
2136 * @param message Message received.
2137 * @param peer Peer who sent the message.
2139 * @return GNUNET_OK to keep the connection open,
2140 * GNUNET_SYSERR to close it (signal serious error)
2143 GCC_handle_encrypted (void *cls, const struct GNUNET_PeerIdentity *peer,
2144 const struct GNUNET_MessageHeader *message)
2146 return handle_cadet_encrypted (peer,
2147 (struct GNUNET_CADET_Encrypted *)message);
2152 * Core handler for key exchange traffic (ephemeral key, ping, pong).
2154 * @param cls Closure (unused).
2155 * @param message Message received.
2156 * @param peer Peer who sent the message.
2158 * @return GNUNET_OK to keep the connection open,
2159 * GNUNET_SYSERR to close it (signal serious error)
2162 GCC_handle_kx (void *cls, const struct GNUNET_PeerIdentity *peer,
2163 const struct GNUNET_MessageHeader *message)
2165 return handle_cadet_kx (peer,
2166 (struct GNUNET_CADET_KX *) message);
2171 * Core handler for cadet network traffic point-to-point acks.
2173 * @param cls closure
2174 * @param message message
2175 * @param peer peer identity this notification is about
2177 * @return GNUNET_OK to keep the connection open,
2178 * GNUNET_SYSERR to close it (signal serious error)
2181 GCC_handle_ack (void *cls, const struct GNUNET_PeerIdentity *peer,
2182 const struct GNUNET_MessageHeader *message)
2184 struct GNUNET_CADET_ACK *msg;
2185 struct CadetConnection *c;
2186 struct CadetFlowControl *fc;
2191 msg = (struct GNUNET_CADET_ACK *) message;
2192 log_message (message, peer, &msg->cid);
2193 c = connection_get (&msg->cid);
2196 GNUNET_STATISTICS_update (stats, "# ack on unknown connection", 1,
2198 send_broken_unknown (&msg->cid, &my_full_id, NULL, peer);
2202 /* Is this a forward or backward ACK? */
2203 id = GNUNET_PEER_search (peer);
2204 if (GCP_get_short_id (get_next_hop (c)) == id)
2206 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD ACK\n");
2210 else if (GCP_get_short_id (get_prev_hop (c)) == id)
2212 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK ACK\n");
2218 GNUNET_break_op (0);
2222 ack = ntohl (msg->ack);
2223 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK %u (was %u)\n",
2224 ack, fc->last_ack_recv);
2225 if (GC_is_pid_bigger (ack, fc->last_ack_recv))
2226 fc->last_ack_recv = ack;
2228 /* Cancel polling if the ACK is big enough. */
2229 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task &&
2230 GC_is_pid_bigger (fc->last_ack_recv, fc->last_pid_sent))
2232 LOG (GNUNET_ERROR_TYPE_DEBUG, " Cancel poll\n");
2233 GNUNET_SCHEDULER_cancel (fc->poll_task);
2234 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
2235 fc->poll_time = GNUNET_TIME_UNIT_SECONDS;
2238 connection_unlock_queue (c, fwd);
2245 * Core handler for cadet network traffic point-to-point ack polls.
2247 * @param cls closure
2248 * @param message message
2249 * @param peer peer identity this notification is about
2251 * @return GNUNET_OK to keep the connection open,
2252 * GNUNET_SYSERR to close it (signal serious error)
2255 GCC_handle_poll (void *cls, const struct GNUNET_PeerIdentity *peer,
2256 const struct GNUNET_MessageHeader *message)
2258 struct GNUNET_CADET_Poll *msg;
2259 struct CadetConnection *c;
2260 struct CadetFlowControl *fc;
2265 msg = (struct GNUNET_CADET_Poll *) message;
2266 log_message (message, peer, &msg->cid);
2267 c = connection_get (&msg->cid);
2270 GNUNET_STATISTICS_update (stats, "# poll on unknown connection", 1,
2272 LOG (GNUNET_ERROR_TYPE_DEBUG, "POLL message on unknown connection %s!\n",
2273 GNUNET_h2s (GC_h2hc (&msg->cid)));
2274 send_broken_unknown (&msg->cid, &my_full_id, NULL, peer);
2278 /* Is this a forward or backward ACK?
2279 * Note: a poll should never be needed in a loopback case,
2280 * since there is no possiblility of packet loss there, so
2281 * this way of discerining FWD/BCK should not be a problem.
2283 id = GNUNET_PEER_search (peer);
2284 if (GCP_get_short_id (get_next_hop (c)) == id)
2286 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD FC\n");
2289 else if (GCP_get_short_id (get_prev_hop (c)) == id)
2291 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK FC\n");
2296 GNUNET_break_op (0);
2300 pid = ntohl (msg->pid);
2301 LOG (GNUNET_ERROR_TYPE_DEBUG, " PID %u, OLD %u\n", pid, fc->last_pid_recv);
2302 fc->last_pid_recv = pid;
2303 fwd = fc == &c->bck_fc;
2304 GCC_send_ack (c, fwd, GNUNET_YES);
2311 * Send an ACK on the appropriate connection/channel, depending on
2312 * the direction and the position of the peer.
2314 * @param c Which connection to send the hop-by-hop ACK.
2315 * @param fwd Is this a fwd ACK? (will go dest->root).
2316 * @param force Send the ACK even if suboptimal (e.g. requested by POLL).
2319 GCC_send_ack (struct CadetConnection *c, int fwd, int force)
2321 unsigned int buffer;
2323 LOG (GNUNET_ERROR_TYPE_DEBUG,
2324 "GMC send %s ACK on %s\n",
2325 GC_f2s (fwd), GCC_2s (c));
2333 if (GNUNET_NO != c->destroy)
2335 LOG (GNUNET_ERROR_TYPE_DEBUG, " being destroyed, why bother...\n");
2339 /* Get available buffer space */
2340 if (GCC_is_terminal (c, fwd))
2342 LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from all channels\n");
2343 buffer = GCT_get_channels_buffer (c->t);
2347 LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from one connection\n");
2348 buffer = GCC_get_buffer (c, fwd);
2350 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer available: %u\n", buffer);
2351 if (0 == buffer && GNUNET_NO == force)
2354 /* Send available buffer space */
2355 if (GCC_is_origin (c, fwd))
2357 GNUNET_assert (NULL != c->t);
2358 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channels...\n");
2359 GCT_unchoke_channels (c->t);
2363 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on connection\n");
2364 send_ack (c, buffer, fwd, force);
2370 * Initialize the connections subsystem
2372 * @param c Configuration handle.
2375 GCC_init (const struct GNUNET_CONFIGURATION_Handle *c)
2377 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
2379 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "MAX_MSGS_QUEUE",
2382 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
2383 "CADET", "MAX_MSGS_QUEUE", "MISSING");
2384 GNUNET_SCHEDULER_shutdown ();
2389 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "MAX_CONNECTIONS",
2392 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
2393 "CADET", "MAX_CONNECTIONS", "MISSING");
2394 GNUNET_SCHEDULER_shutdown ();
2399 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REFRESH_CONNECTION_TIME",
2400 &refresh_connection_time))
2402 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
2403 "CADET", "REFRESH_CONNECTION_TIME", "MISSING");
2404 GNUNET_SCHEDULER_shutdown ();
2407 create_connection_time = GNUNET_TIME_UNIT_SECONDS;
2408 connections = GNUNET_CONTAINER_multihashmap_create (1024, GNUNET_NO);
2413 * Destroy each connection on shutdown.
2415 * @param cls Closure (unused).
2416 * @param key Current key code (CID, unused).
2417 * @param value Value in the hash map (connection)
2419 * @return #GNUNET_YES, because we should continue to iterate,
2422 shutdown_iterator (void *cls,
2423 const struct GNUNET_HashCode *key,
2426 struct CadetConnection *c = value;
2434 * Shut down the connections subsystem.
2439 GNUNET_CONTAINER_multihashmap_iterate (connections, &shutdown_iterator, NULL);
2440 GNUNET_CONTAINER_multihashmap_destroy (connections);
2445 struct CadetConnection *
2446 GCC_new (const struct GNUNET_CADET_Hash *cid,
2447 struct CadetTunnel *t,
2448 struct CadetPeerPath *p,
2449 unsigned int own_pos)
2451 struct CadetConnection *c;
2453 c = GNUNET_new (struct CadetConnection);
2455 GNUNET_assert (GNUNET_OK ==
2456 GNUNET_CONTAINER_multihashmap_put (connections,
2458 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
2459 fc_init (&c->fwd_fc);
2460 fc_init (&c->bck_fc);
2465 GNUNET_assert (own_pos <= p->length - 1);
2466 c->own_pos = own_pos;
2470 if (GNUNET_OK != register_neighbors (c))
2474 path_invalidate (c->path);
2487 GCC_destroy (struct CadetConnection *c)
2495 if (2 == c->destroy) /* cancel queues -> GCP_queue_cancel -> q_destroy -> */
2496 return; /* -> message_sent -> GCC_destroy. Don't loop. */
2499 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying connection %s\n", GCC_2s (c));
2500 LOG (GNUNET_ERROR_TYPE_DEBUG, " fc's f: %p, b: %p\n",
2501 &c->fwd_fc, &c->bck_fc);
2502 LOG (GNUNET_ERROR_TYPE_DEBUG, " fc tasks f: %u, b: %u\n",
2503 c->fwd_fc.poll_task, c->bck_fc.poll_task);
2505 /* Cancel all traffic */
2506 if (NULL != c->path)
2508 connection_cancel_queues (c, GNUNET_YES);
2509 connection_cancel_queues (c, GNUNET_NO);
2510 unregister_neighbors (c);
2513 LOG (GNUNET_ERROR_TYPE_DEBUG, " fc tasks f: %u, b: %u\n",
2514 c->fwd_fc.poll_task, c->bck_fc.poll_task);
2516 /* Cancel maintainance task (keepalive/timeout) */
2517 if (NULL != c->fwd_fc.poll_msg)
2519 GCC_cancel (c->fwd_fc.poll_msg);
2520 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL msg FWD canceled\n");
2522 if (NULL != c->bck_fc.poll_msg)
2524 GCC_cancel (c->bck_fc.poll_msg);
2525 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL msg BCK canceled\n");
2528 /* Delete from tunnel */
2530 GCT_remove_connection (c->t, c);
2532 if (GNUNET_NO == GCC_is_origin (c, GNUNET_YES) && NULL != c->path)
2533 path_destroy (c->path);
2534 if (GNUNET_SCHEDULER_NO_TASK != c->fwd_maintenance_task)
2535 GNUNET_SCHEDULER_cancel (c->fwd_maintenance_task);
2536 if (GNUNET_SCHEDULER_NO_TASK != c->bck_maintenance_task)
2537 GNUNET_SCHEDULER_cancel (c->bck_maintenance_task);
2538 if (GNUNET_SCHEDULER_NO_TASK != c->fwd_fc.poll_task)
2540 GNUNET_SCHEDULER_cancel (c->fwd_fc.poll_task);
2541 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL FWD canceled\n");
2543 if (GNUNET_SCHEDULER_NO_TASK != c->bck_fc.poll_task)
2545 GNUNET_SCHEDULER_cancel (c->bck_fc.poll_task);
2546 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL BCK canceled\n");
2549 GNUNET_break (GNUNET_YES ==
2550 GNUNET_CONTAINER_multihashmap_remove (connections,
2553 GNUNET_STATISTICS_update (stats, "# connections", -1, GNUNET_NO);
2558 * Get the connection ID.
2560 * @param c Connection to get the ID from.
2562 * @return ID of the connection.
2564 const struct GNUNET_CADET_Hash *
2565 GCC_get_id (const struct CadetConnection *c)
2572 * Get the connection ID.
2574 * @param c Connection to get the ID from.
2576 * @return ID of the connection.
2578 const struct GNUNET_HashCode *
2579 GCC_get_h (const struct CadetConnection *c)
2581 return GC_h2hc (&c->id);
2586 * Get the connection path.
2588 * @param c Connection to get the path from.
2590 * @return path used by the connection.
2592 const struct CadetPeerPath *
2593 GCC_get_path (const struct CadetConnection *c)
2595 if (GNUNET_NO == c->destroy)
2602 * Get the connection state.
2604 * @param c Connection to get the state from.
2606 * @return state of the connection.
2608 enum CadetConnectionState
2609 GCC_get_state (const struct CadetConnection *c)
2615 * Get the connection tunnel.
2617 * @param c Connection to get the tunnel from.
2619 * @return tunnel of the connection.
2621 struct CadetTunnel *
2622 GCC_get_tunnel (const struct CadetConnection *c)
2629 * Get free buffer space in a connection.
2631 * @param c Connection.
2632 * @param fwd Is query about FWD traffic?
2634 * @return Free buffer space [0 - max_msgs_queue/max_connections]
2637 GCC_get_buffer (struct CadetConnection *c, int fwd)
2639 struct CadetFlowControl *fc;
2641 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2643 return (fc->queue_max - fc->queue_n);
2647 * Get how many messages have we allowed to send to us from a direction.
2649 * @param c Connection.
2650 * @param fwd Are we asking about traffic from FWD (BCK messages)?
2652 * @return last_ack_sent - last_pid_recv
2655 GCC_get_allowed (struct CadetConnection *c, int fwd)
2657 struct CadetFlowControl *fc;
2659 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2660 if (GC_is_pid_bigger(fc->last_pid_recv, fc->last_ack_sent))
2664 return (fc->last_ack_sent - fc->last_pid_recv);
2668 * Get messages queued in a connection.
2670 * @param c Connection.
2671 * @param fwd Is query about FWD traffic?
2673 * @return Number of messages queued.
2676 GCC_get_qn (struct CadetConnection *c, int fwd)
2678 struct CadetFlowControl *fc;
2680 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2687 * Get next PID to use.
2689 * @param c Connection.
2690 * @param fwd Is query about FWD traffic?
2692 * @return Last PID used + 1.
2695 GCC_get_pid (struct CadetConnection *c, int fwd)
2697 struct CadetFlowControl *fc;
2699 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2701 return fc->last_pid_sent + 1;
2706 * Allow the connection to advertise a buffer of the given size.
2708 * The connection will send an @c fwd ACK message (so: in direction !fwd)
2709 * allowing up to last_pid_recv + buffer.
2711 * @param c Connection.
2712 * @param buffer How many more messages the connection can accept.
2713 * @param fwd Is this about FWD traffic? (The ack will go dest->root).
2716 GCC_allow (struct CadetConnection *c, unsigned int buffer, int fwd)
2718 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowing %s %u messages %s\n",
2719 GCC_2s (c), buffer, GC_f2s (fwd));
2720 send_ack (c, buffer, fwd, GNUNET_NO);
2725 * Notify other peers on a connection of a broken link. Mark connections
2726 * to destroy after all traffic has been sent.
2728 * @param c Connection on which there has been a disconnection.
2729 * @param peer Peer that disconnected.
2732 GCC_notify_broken (struct CadetConnection *c,
2733 struct CadetPeer *peer)
2737 LOG (GNUNET_ERROR_TYPE_DEBUG,
2738 " notify broken on %s due to %s disconnect\n",
2739 GCC_2s (c), GCP_2s (peer));
2741 fwd = peer == get_prev_hop (c);
2743 if (GNUNET_YES == GCC_is_terminal (c, fwd))
2745 /* Local shutdown, no one to notify about this. */
2749 if (GNUNET_NO == c->destroy)
2750 send_broken (c, &my_full_id, GCP_get_id (peer), fwd);
2752 /* Connection will have at least one pending message
2753 * (the one we just scheduled), so no point in checking whether to
2754 * destroy immediately. */
2755 c->destroy = GNUNET_YES;
2756 c->state = CADET_CONNECTION_DESTROYED;
2759 * Cancel all queues, if no message is left, connection will be destroyed.
2761 connection_cancel_queues (c, !fwd);
2768 * Is this peer the first one on the connection?
2770 * @param c Connection.
2771 * @param fwd Is this about fwd traffic?
2773 * @return #GNUNET_YES if origin, #GNUNET_NO if relay/terminal.
2776 GCC_is_origin (struct CadetConnection *c, int fwd)
2778 if (!fwd && c->path->length - 1 == c->own_pos )
2780 if (fwd && 0 == c->own_pos)
2787 * Is this peer the last one on the connection?
2789 * @param c Connection.
2790 * @param fwd Is this about fwd traffic?
2791 * Note that the ROOT is the terminal for BCK traffic!
2793 * @return #GNUNET_YES if terminal, #GNUNET_NO if relay/origin.
2796 GCC_is_terminal (struct CadetConnection *c, int fwd)
2798 return GCC_is_origin (c, !fwd);
2803 * See if we are allowed to send by the next hop in the given direction.
2805 * @param c Connection.
2806 * @param fwd Is this about fwd traffic?
2808 * @return #GNUNET_YES in case it's OK to send.
2811 GCC_is_sendable (struct CadetConnection *c, int fwd)
2813 struct CadetFlowControl *fc;
2815 LOG (GNUNET_ERROR_TYPE_DEBUG, " checking sendability of %s traffic on %s\n",
2816 GC_f2s (fwd), GCC_2s (c));
2822 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2823 LOG (GNUNET_ERROR_TYPE_DEBUG,
2824 " last ack recv: %u, last pid sent: %u\n",
2825 fc->last_ack_recv, fc->last_pid_sent);
2826 if (GC_is_pid_bigger (fc->last_ack_recv, fc->last_pid_sent))
2828 LOG (GNUNET_ERROR_TYPE_DEBUG, " sendable\n");
2831 LOG (GNUNET_ERROR_TYPE_DEBUG, " not sendable\n");
2837 * Check if this connection is a direct one (never trim a direct connection).
2839 * @param c Connection.
2841 * @return #GNUNET_YES in case it's a direct connection, #GNUNET_NO otherwise.
2844 GCC_is_direct (struct CadetConnection *c)
2846 return (c->path->length == 2) ? GNUNET_YES : GNUNET_NO;
2850 * Sends an already built message on a connection, properly registering
2851 * all used resources.
2853 * @param message Message to send. Function makes a copy of it.
2854 * If message is not hop-by-hop, decrements TTL of copy.
2855 * @param payload_type Type of payload, in case the message is encrypted.
2856 * @param c Connection on which this message is transmitted.
2857 * @param fwd Is this a fwd message?
2858 * @param force Force the connection to accept the message (buffer overfill).
2859 * @param cont Continuation called once message is sent. Can be NULL.
2860 * @param cont_cls Closure for @c cont.
2862 * @return Handle to cancel the message before it's sent.
2863 * NULL on error or if @c cont is NULL.
2864 * Invalid on @c cont call.
2866 struct CadetConnectionQueue *
2867 GCC_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2868 uint16_t payload_type, uint32_t payload_id,
2869 struct CadetConnection *c, int fwd, int force,
2870 GCC_sent cont, void *cont_cls)
2872 struct CadetFlowControl *fc;
2873 struct CadetConnectionQueue *q;
2879 size = ntohs (message->size);
2880 data = GNUNET_malloc (size);
2881 memcpy (data, message, size);
2882 type = ntohs (message->type);
2883 LOG (GNUNET_ERROR_TYPE_INFO, "--> %s (%s %u) on connection %s (%u bytes)\n",
2884 GC_m2s (type), GC_m2s (payload_type), payload_id, GCC_2s (c), size);
2886 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2887 droppable = GNUNET_NO == force;
2890 struct GNUNET_CADET_Encrypted *emsg;
2891 struct GNUNET_CADET_KX *kmsg;
2892 struct GNUNET_CADET_ACK *amsg;
2893 struct GNUNET_CADET_Poll *pmsg;
2894 struct GNUNET_CADET_ConnectionDestroy *dmsg;
2895 struct GNUNET_CADET_ConnectionBroken *bmsg;
2898 case GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED:
2899 emsg = (struct GNUNET_CADET_Encrypted *) data;
2900 ttl = ntohl (emsg->ttl);
2903 GNUNET_break_op (0);
2908 emsg->ttl = htonl (ttl - 1);
2909 emsg->pid = htonl (0);
2910 LOG (GNUNET_ERROR_TYPE_DEBUG, " Q_N+ %p %u\n", fc, fc->queue_n);
2911 LOG (GNUNET_ERROR_TYPE_DEBUG, "last pid sent %u\n", fc->last_pid_sent);
2912 LOG (GNUNET_ERROR_TYPE_DEBUG, " ack recv %u\n", fc->last_ack_recv);
2913 if (GNUNET_YES == droppable)
2919 LOG (GNUNET_ERROR_TYPE_DEBUG, " not droppable, Q_N stays the same\n");
2921 if (GC_is_pid_bigger (fc->last_pid_sent + 1, fc->last_ack_recv))
2923 GCC_start_poll (c, fwd);
2927 case GNUNET_MESSAGE_TYPE_CADET_KX:
2928 kmsg = (struct GNUNET_CADET_KX *) data;
2932 case GNUNET_MESSAGE_TYPE_CADET_ACK:
2933 amsg = (struct GNUNET_CADET_ACK *) data;
2935 LOG (GNUNET_ERROR_TYPE_DEBUG, " ack %u\n", ntohl (amsg->ack));
2936 droppable = GNUNET_NO;
2939 case GNUNET_MESSAGE_TYPE_CADET_POLL:
2940 pmsg = (struct GNUNET_CADET_Poll *) data;
2942 LOG (GNUNET_ERROR_TYPE_DEBUG, " poll %u\n", ntohl (pmsg->pid));
2943 droppable = GNUNET_NO;
2946 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY:
2947 dmsg = (struct GNUNET_CADET_ConnectionDestroy *) data;
2951 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN:
2952 bmsg = (struct GNUNET_CADET_ConnectionBroken *) data;
2956 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
2959 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE:
2960 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_ACK:
2969 if (fc->queue_n > fc->queue_max && droppable)
2971 GNUNET_STATISTICS_update (stats, "# messages dropped (buffer full)",
2974 LOG (GNUNET_ERROR_TYPE_DEBUG,
2975 "queue full: %u/%u\n",
2976 fc->queue_n, fc->queue_max);
2977 if (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED == type)
2982 return NULL; /* Drop this message */
2985 LOG (GNUNET_ERROR_TYPE_DEBUG, " C_P+ %p %u\n", c, c->pending_messages);
2986 c->pending_messages++;
2988 q = GNUNET_new (struct CadetConnectionQueue);
2989 q->forced = !droppable;
2990 q->q = GCP_queue_add (get_hop (c, fwd), data, type, payload_type, payload_id,
2991 size, c, fwd, &conn_message_sent, q);
2994 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING dropping msg on %s\n", GCC_2s (c));
3000 q->cont_cls = cont_cls;
3001 return (NULL == cont) ? NULL : q;
3006 * Cancel a previously sent message while it's in the queue.
3008 * ONLY can be called before the continuation given to the send function
3009 * is called. Once the continuation is called, the message is no longer in the
3012 * @param q Handle to the queue.
3015 GCC_cancel (struct CadetConnectionQueue *q)
3017 LOG (GNUNET_ERROR_TYPE_DEBUG, "! GMC cancel message\n");
3019 /* queue destroy calls message_sent, which calls q->cont and frees q */
3020 GCP_queue_destroy (q->q, GNUNET_YES, GNUNET_NO, 0);
3025 * Sends a CREATE CONNECTION message for a path to a peer.
3026 * Changes the connection and tunnel states if necessary.
3028 * @param connection Connection to create.
3031 GCC_send_create (struct CadetConnection *connection)
3033 enum CadetTunnelCState state;
3036 size = sizeof (struct GNUNET_CADET_ConnectionCreate);
3037 size += connection->path->length * sizeof (struct GNUNET_PeerIdentity);
3039 LOG (GNUNET_ERROR_TYPE_INFO, "===> %s on connection %s (%u bytes)\n",
3040 GC_m2s (GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE),
3041 GCC_2s (connection), size);
3042 LOG (GNUNET_ERROR_TYPE_DEBUG, " C_P+ %p %u (create)\n",
3043 connection, connection->pending_messages);
3044 connection->pending_messages++;
3046 connection->maintenance_q =
3047 GCP_queue_add (get_next_hop (connection), NULL,
3048 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE, 0, 0,
3049 size, connection, GNUNET_YES, &conn_message_sent, NULL);
3051 state = GCT_get_cstate (connection->t);
3052 if (CADET_TUNNEL_SEARCHING == state || CADET_TUNNEL_NEW == state)
3053 GCT_change_cstate (connection->t, CADET_TUNNEL_WAITING);
3054 if (CADET_CONNECTION_NEW == connection->state)
3055 connection_change_state (connection, CADET_CONNECTION_SENT);
3060 * Send a message to all peers in this connection that the connection
3061 * is no longer valid.
3063 * If some peer should not receive the message, it should be zero'ed out
3064 * before calling this function.
3066 * @param c The connection whose peers to notify.
3069 GCC_send_destroy (struct CadetConnection *c)
3071 struct GNUNET_CADET_ConnectionDestroy msg;
3073 if (GNUNET_YES == c->destroy)
3076 msg.header.size = htons (sizeof (msg));
3077 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY);
3079 LOG (GNUNET_ERROR_TYPE_DEBUG,
3080 " sending connection destroy for connection %s\n",
3083 if (GNUNET_NO == GCC_is_terminal (c, GNUNET_YES))
3084 GNUNET_assert (NULL == GCC_send_prebuilt_message (&msg.header, 0, 0, c,
3085 GNUNET_YES, GNUNET_YES,
3087 if (GNUNET_NO == GCC_is_terminal (c, GNUNET_NO))
3088 GNUNET_assert (NULL == GCC_send_prebuilt_message (&msg.header, 0, 0, c,
3089 GNUNET_NO, GNUNET_YES,
3091 c->destroy = GNUNET_YES;
3092 c->state = CADET_CONNECTION_DESTROYED;
3097 * @brief Start a polling timer for the connection.
3099 * When a neighbor does not accept more traffic on the connection it could be
3100 * caused by a simple congestion or by a lost ACK. Polling enables to check
3101 * for the lastest ACK status for a connection.
3103 * @param c Connection.
3104 * @param fwd Should we poll in the FWD direction?
3107 GCC_start_poll (struct CadetConnection *c, int fwd)
3109 struct CadetFlowControl *fc;
3111 fc = fwd ? &c->fwd_fc : &c->bck_fc;
3112 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL %s requested\n",
3114 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task || NULL != fc->poll_msg)
3116 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** not needed (%u, %p)\n",
3117 fc->poll_task, fc->poll_msg);
3120 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL started on request\n");
3121 fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time,
3128 * @brief Stop polling a connection for ACKs.
3130 * Once we have enough ACKs for future traffic, polls are no longer necessary.
3132 * @param c Connection.
3133 * @param fwd Should we stop the poll in the FWD direction?
3136 GCC_stop_poll (struct CadetConnection *c, int fwd)
3138 struct CadetFlowControl *fc;
3140 fc = fwd ? &c->fwd_fc : &c->bck_fc;
3141 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task)
3143 GNUNET_SCHEDULER_cancel (fc->poll_task);
3144 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
3149 * Get a (static) string for a connection.
3151 * @param c Connection.
3154 GCC_2s (const struct CadetConnection *c)
3161 static char buf[128];
3163 sprintf (buf, "%s (->%s)",
3164 GNUNET_h2s (GC_h2hc (GCC_get_id (c))), GCT_2s (c->t));
3167 return GNUNET_h2s (GC_h2hc (&c->id));