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diff --git a/src/cadet/gnunet-service-cadet_connection.c b/src/cadet/gnunet-service-cadet_connection.c
deleted file mode 100644
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1/*
2 This file is part of GNUnet.
3 Copyright (C) 2001-2015 GNUnet e.V.
4
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.
9
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.
14
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., 51 Franklin Street, Fifth Floor,
18 Boston, MA 02110-1301, USA.
19*/
20/**
21 * @file cadet/gnunet-service-cadet_connection.c
22 * @brief GNUnet CADET service connection handling
23 * @author Bartlomiej Polot
24 */
25#include "platform.h"
26#include "gnunet_util_lib.h"
27#include "gnunet_statistics_service.h"
28#include "cadet_path.h"
29#include "cadet_protocol.h"
30#include "cadet.h"
31#include "gnunet-service-cadet_connection.h"
32#include "gnunet-service-cadet_peer.h"
33#include "gnunet-service-cadet_tunnel.h"
34
35
36/**
37 * Should we run somewhat expensive checks on our invariants?
38 */
39#define CHECK_INVARIANTS 0
40
41
42#define LOG(level, ...) GNUNET_log_from (level,"cadet-con",__VA_ARGS__)
43#define LOG2(level, ...) GNUNET_log_from_nocheck(level,"cadet-con",__VA_ARGS__)
44
45
46#define CADET_MAX_POLL_TIME GNUNET_TIME_relative_multiply (\
47 GNUNET_TIME_UNIT_MINUTES,\
48 10)
49#define AVG_MSGS 32
50
51
52/******************************************************************************/
53/******************************** STRUCTS **********************************/
54/******************************************************************************/
55
56/**
57 * Handle for messages queued but not yet sent.
58 */
59struct CadetConnectionQueue
60{
61
62 struct CadetConnectionQueue *next;
63 struct CadetConnectionQueue *prev;
64
65 /**
66 * Peer queue handle, to cancel if necessary.
67 */
68 struct CadetPeerQueue *peer_q;
69
70 /**
71 * Continuation to call once sent.
72 */
73 GCC_sent cont;
74
75 /**
76 * Closure for @e cont.
77 */
78 void *cont_cls;
79
80 /**
81 * Was this a forced message? (Do not account for it)
82 */
83 int forced;
84};
85
86
87/**
88 * Struct to encapsulate all the Flow Control information to a peer to which
89 * we are directly connected (on a core level).
90 */
91struct CadetFlowControl
92{
93 /**
94 * Connection this controls.
95 */
96 struct CadetConnection *c;
97
98 struct CadetConnectionQueue *q_head;
99 struct CadetConnectionQueue *q_tail;
100
101 /**
102 * How many messages are in the queue on this connection.
103 */
104 unsigned int queue_n;
105
106 /**
107 * How many messages do we accept in the queue.
108 * If 0, the connection is broken in this direction (next hop disconnected).
109 */
110 unsigned int queue_max;
111
112 /**
113 * ID of the next packet to send.
114 */
115 struct CadetEncryptedMessageIdentifier next_pid;
116
117 /**
118 * ID of the last packet sent towards the peer.
119 */
120 struct CadetEncryptedMessageIdentifier last_pid_sent;
121
122 /**
123 * ID of the last packet received from the peer.
124 */
125 struct CadetEncryptedMessageIdentifier last_pid_recv;
126
127 /**
128 * Bitmap of past 32 messages received:
129 * - LSB being @c last_pid_recv.
130 * - MSB being @c last_pid_recv - 31 (mod UINTMAX).
131 */
132 uint32_t recv_bitmap;
133
134 /**
135 * Last ACK sent to the peer (peer is not allowed to send
136 * messages with PIDs higher than this value).
137 */
138 struct CadetEncryptedMessageIdentifier last_ack_sent;
139
140 /**
141 * Last ACK sent towards the origin (for traffic towards leaf node).
142 */
143 struct CadetEncryptedMessageIdentifier last_ack_recv;
144
145 /**
146 * Task to poll the peer in case of a lost ACK causes stall.
147 */
148 struct GNUNET_SCHEDULER_Task *poll_task;
149
150 /**
151 * How frequently to poll for ACKs.
152 */
153 struct GNUNET_TIME_Relative poll_time;
154
155 /**
156 * Queued poll message, to cancel if not necessary anymore (got ACK).
157 */
158 struct CadetConnectionQueue *poll_msg;
159
160 /**
161 * Queued poll message, to cancel if not necessary anymore (got ACK).
162 */
163 struct CadetConnectionQueue *ack_msg;
164};
165
166/**
167 * Keep a record of the last messages sent on this connection.
168 */
169struct CadetConnectionPerformance
170{
171 /**
172 * Circular buffer for storing measurements.
173 */
174 double usecsperbyte[AVG_MSGS];
175
176 /**
177 * Running average of @c usecsperbyte.
178 */
179 double avg;
180
181 /**
182 * How many values of @c usecsperbyte are valid.
183 */
184 uint16_t size;
185
186 /**
187 * Index of the next "free" position in @c usecsperbyte.
188 */
189 uint16_t idx;
190};
191
192
193/**
194 * Struct containing all information regarding a connection to a peer.
195 */
196struct CadetConnection
197{
198 /**
199 * Tunnel this connection is part of.
200 */
201 struct CadetTunnel *t;
202
203 /**
204 * Flow control information for traffic fwd.
205 */
206 struct CadetFlowControl fwd_fc;
207
208 /**
209 * Flow control information for traffic bck.
210 */
211 struct CadetFlowControl bck_fc;
212
213 /**
214 * Measure connection performance on the endpoint.
215 */
216 struct CadetConnectionPerformance *perf;
217
218 /**
219 * ID of the connection.
220 */
221 struct GNUNET_CADET_ConnectionTunnelIdentifier id;
222
223 /**
224 * Path being used for the tunnel. At the origin of the connection
225 * it's a pointer to the destination's path pool, otherwise just a copy.
226 */
227 struct CadetPeerPath *path;
228
229 /**
230 * Task to keep the used paths alive at the owner,
231 * time tunnel out on all the other peers.
232 */
233 struct GNUNET_SCHEDULER_Task *fwd_maintenance_task;
234
235 /**
236 * Task to keep the used paths alive at the destination,
237 * time tunnel out on all the other peers.
238 */
239 struct GNUNET_SCHEDULER_Task *bck_maintenance_task;
240
241 /**
242 * Queue handle for maintainance traffic. One handle for FWD and BCK since
243 * one peer never needs to maintain both directions (no loopback connections).
244 */
245 struct CadetPeerQueue *maintenance_q;
246
247 /**
248 * Should equal #get_next_hop(), or NULL if that peer disconnected.
249 */
250 struct CadetPeer *next_peer;
251
252 /**
253 * Should equal #get_prev_hop(), or NULL if that peer disconnected.
254 */
255 struct CadetPeer *prev_peer;
256
257 /**
258 * State of the connection.
259 */
260 enum CadetConnectionState state;
261
262 /**
263 * Position of the local peer in the path.
264 */
265 unsigned int own_pos;
266
267 /**
268 * Pending message count.
269 */
270 unsigned int pending_messages;
271
272 /**
273 * Destroy flag:
274 * - if 0, connection in use.
275 * - if 1, destroy on last message.
276 * - if 2, connection is being destroyed don't re-enter.
277 */
278 int destroy;
279
280 /**
281 * In-connection-map flag. Sometimes, when @e destroy is set but
282 * actual destruction is delayed to enable us to finish processing
283 * queues (i.e. in the direction that is still working), we remove
284 * the connection from the map to prevent it from still being
285 * found (and used) by accident. This flag is set to #GNUNET_YES
286 * for a connection that is not in the #connections map. Should
287 * only be #GNUNET_YES if #destroy is also non-zero.
288 */
289 int was_removed;
290
291 /**
292 * Counter to do exponential backoff when creating a connection (max 64).
293 */
294 unsigned short create_retry;
295
296 /**
297 * Task to check if connection has duplicates.
298 */
299 struct GNUNET_SCHEDULER_Task *check_duplicates_task;
300};
301
302
303/******************************************************************************/
304/******************************* GLOBALS ***********************************/
305/******************************************************************************/
306
307/**
308 * Global handle to the statistics service.
309 */
310extern struct GNUNET_STATISTICS_Handle *stats;
311
312/**
313 * Local peer own ID (memory efficient handle).
314 */
315extern GNUNET_PEER_Id myid;
316
317/**
318 * Local peer own ID (full value).
319 */
320extern struct GNUNET_PeerIdentity my_full_id;
321
322/**
323 * Connections known, indexed by cid (CadetConnection).
324 */
325static struct GNUNET_CONTAINER_MultiShortmap *connections;
326
327/**
328 * How many connections are we willing to maintain.
329 * Local connections are always allowed,
330 * even if there are more connections than max.
331 */
332static unsigned long long max_connections;
333
334/**
335 * How many messages *in total* are we willing to queue, divide by number of
336 * connections to get connection queue size.
337 */
338static unsigned long long max_msgs_queue;
339
340/**
341 * How often to send path keepalives. Paths timeout after 4 missed.
342 */
343static struct GNUNET_TIME_Relative refresh_connection_time;
344
345/**
346 * How often to send path create / ACKs.
347 */
348static struct GNUNET_TIME_Relative create_connection_time;
349
350
351/******************************************************************************/
352/******************************** STATIC ***********************************/
353/******************************************************************************/
354
355
356
357#if 0 // avoid compiler warning for unused static function
358static void
359fc_debug (struct CadetFlowControl *fc)
360{
361 LOG (GNUNET_ERROR_TYPE_DEBUG, " IN: %u/%u\n",
362 ntohl (fc->last_pid_recv.pid),
363 ntohl (fc->last_ack_sent.pid));
364 LOG (GNUNET_ERROR_TYPE_DEBUG, " OUT: %u/%u\n",
365 fc->last_pid_sent, fc->last_ack_recv);
366 LOG (GNUNET_ERROR_TYPE_DEBUG, " QUEUE: %u/%u\n",
367 fc->queue_n, fc->queue_max);
368}
369
370static void
371connection_debug (struct CadetConnection *c)
372{
373 if (NULL == c)
374 {
375 LOG (GNUNET_ERROR_TYPE_INFO, "DEBUG NULL CONNECTION\n");
376 return;
377 }
378 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s:%X\n",
379 peer2s (c->t->peer), GCC_2s (c));
380 LOG (GNUNET_ERROR_TYPE_DEBUG, " state: %u, pending msgs: %u\n",
381 c->state, c->pending_messages);
382 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD FC\n");
383 fc_debug (&c->fwd_fc);
384 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK FC\n");
385 fc_debug (&c->bck_fc);
386}
387#endif
388
389
390/**
391 * Schedule next keepalive task, taking in consideration
392 * the connection state and number of retries.
393 *
394 * @param c Connection for which to schedule the next keepalive.
395 * @param fwd Direction for the next keepalive.
396 */
397static void
398schedule_next_keepalive (struct CadetConnection *c, int fwd);
399
400
401/**
402 * Resets the connection timeout task, some other message has done the
403 * task's job.
404 * - For the first peer on the direction this means to send
405 * a keepalive or a path confirmation message (either create or ACK).
406 * - For all other peers, this means to destroy the connection,
407 * due to lack of activity.
408 * Starts the timeout if no timeout was running (connection just created).
409 *
410 * @param c Connection whose timeout to reset.
411 * @param fwd Is this forward?
412 */
413static void
414connection_reset_timeout (struct CadetConnection *c, int fwd);
415
416
417/**
418 * Get string description for tunnel state. Reentrant.
419 *
420 * @param s Tunnel state.
421 *
422 * @return String representation.
423 */
424static const char *
425GCC_state2s (enum CadetConnectionState s)
426{
427 switch (s)
428 {
429 case CADET_CONNECTION_NEW:
430 return "CADET_CONNECTION_NEW";
431 case CADET_CONNECTION_SENT:
432 return "CADET_CONNECTION_SENT";
433 case CADET_CONNECTION_ACK:
434 return "CADET_CONNECTION_ACK";
435 case CADET_CONNECTION_READY:
436 return "CADET_CONNECTION_READY";
437 case CADET_CONNECTION_DESTROYED:
438 return "CADET_CONNECTION_DESTROYED";
439 case CADET_CONNECTION_BROKEN:
440 return "CADET_CONNECTION_BROKEN";
441 default:
442 GNUNET_break (0);
443 LOG (GNUNET_ERROR_TYPE_ERROR, " conn state %u unknown!\n", s);
444 return "CADET_CONNECTION_STATE_ERROR";
445 }
446}
447
448
449/**
450 * Initialize a Flow Control structure to the initial state.
451 *
452 * @param fc Flow Control structure to initialize.
453 */
454static void
455fc_init (struct CadetFlowControl *fc)
456{
457 fc->next_pid.pid = 0;
458 fc->last_pid_sent.pid = htonl (UINT32_MAX);
459 fc->last_pid_recv.pid = htonl (UINT32_MAX);
460 fc->last_ack_sent.pid = (uint32_t) 0;
461 fc->last_ack_recv.pid = (uint32_t) 0;
462 fc->poll_task = NULL;
463 fc->poll_time = GNUNET_TIME_UNIT_SECONDS;
464 fc->queue_n = 0;
465 fc->queue_max = (max_msgs_queue / max_connections) + 1;
466}
467
468
469/**
470 * Find a connection.
471 *
472 * @param cid Connection ID.
473 *
474 * @return conntection with the given ID @cid or NULL if not found.
475 */
476static struct CadetConnection *
477connection_get (const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid)
478{
479 return GNUNET_CONTAINER_multishortmap_get (connections,
480 &cid->connection_of_tunnel);
481}
482
483
484/**
485 * Change the connection state. Cannot change a connection marked as destroyed.
486 *
487 * @param c Connection to change.
488 * @param state New state to set.
489 */
490static void
491connection_change_state (struct CadetConnection* c,
492 enum CadetConnectionState state)
493{
494 LOG (GNUNET_ERROR_TYPE_DEBUG,
495 "Connection %s state %s -> %s\n",
496 GCC_2s (c), GCC_state2s (c->state), GCC_state2s (state));
497 if (CADET_CONNECTION_DESTROYED <= c->state) /* Destroyed or broken. */
498 {
499 LOG (GNUNET_ERROR_TYPE_DEBUG, "state not changing anymore\n");
500 return;
501 }
502 c->state = state;
503 if (CADET_CONNECTION_READY == state)
504 c->create_retry = 1;
505}
506
507
508/**
509 * Mark a connection as "destroyed", to send all pending traffic and freeing
510 * all associated resources, without accepting new status changes on it.
511 *
512 * @param c Connection to mark as destroyed.
513 */
514static void
515mark_destroyed (struct CadetConnection *c)
516{
517 c->destroy = GNUNET_YES;
518 connection_change_state (c, CADET_CONNECTION_DESTROYED);
519}
520
521
522/**
523 * Function called if a connection has been stalled for a while,
524 * possibly due to a missed ACK. Poll the neighbor about its ACK status.
525 *
526 * @param cls Closure (poll ctx).
527 */
528static void
529send_poll (void *cls);
530
531
532/**
533 * Send an ACK on the connection, informing the predecessor about
534 * the available buffer space. Should not be called in case the peer
535 * is origin (no predecessor) in the @c fwd direction.
536 *
537 * Note that for fwd ack, the FWD mean forward *traffic* (root->dest),
538 * the ACK itself goes "back" (dest->root).
539 *
540 * @param c Connection on which to send the ACK.
541 * @param buffer How much space free to advertise?
542 * @param fwd Is this FWD ACK? (Going dest -> root)
543 * @param force Don't optimize out.
544 */
545static void
546send_ack (struct CadetConnection *c,
547 unsigned int buffer,
548 int fwd,
549 int force)
550{
551 static struct CadetEncryptedMessageIdentifier zero;
552 struct CadetFlowControl *next_fc;
553 struct CadetFlowControl *prev_fc;
554 struct GNUNET_CADET_ConnectionEncryptedAckMessage msg;
555 struct CadetEncryptedMessageIdentifier ack_cemi;
556 int delta;
557
558 GCC_check_connections ();
559 GNUNET_assert (GNUNET_NO == GCC_is_origin (c, fwd));
560
561 next_fc = fwd ? &c->fwd_fc : &c->bck_fc;
562 prev_fc = fwd ? &c->bck_fc : &c->fwd_fc;
563
564 LOG (GNUNET_ERROR_TYPE_DEBUG, "send %s ack on %s\n",
565 GC_f2s (fwd), GCC_2s (c));
566
567 /* Check if we need to transmit the ACK. */
568 delta = ntohl (prev_fc->last_ack_sent.pid) - ntohl (prev_fc->last_pid_recv.pid);
569 if (3 < delta && buffer < delta && GNUNET_NO == force)
570 {
571 LOG (GNUNET_ERROR_TYPE_DEBUG, "Not sending ACK, delta > 3\n");
572 LOG (GNUNET_ERROR_TYPE_DEBUG,
573 " last pid recv: %u, last ack sent: %u\n",
574 ntohl (prev_fc->last_pid_recv.pid),
575 ntohl (prev_fc->last_ack_sent.pid));
576 GCC_check_connections ();
577 return;
578 }
579
580 /* Ok, ACK might be necessary, what PID to ACK? */
581 ack_cemi.pid = htonl (ntohl (prev_fc->last_pid_recv.pid) + buffer);
582 LOG (GNUNET_ERROR_TYPE_DEBUG,
583 " ACK %u, last PID %u, last ACK %u, qmax %u, q %u\n",
584 ntohl (ack_cemi.pid),
585 ntohl (prev_fc->last_pid_recv.pid),
586 ntohl (prev_fc->last_ack_sent.pid),
587 next_fc->queue_max, next_fc->queue_n);
588 if ( (ack_cemi.pid == prev_fc->last_ack_sent.pid) &&
589 (GNUNET_NO == force) )
590 {
591 LOG (GNUNET_ERROR_TYPE_DEBUG, "Not sending FWD ACK, not needed\n");
592 GCC_check_connections ();
593 return;
594 }
595
596 /* Check if message is already in queue */
597 if (NULL != prev_fc->ack_msg)
598 {
599 if (GC_is_pid_bigger (ntohl (ack_cemi.pid),
600 ntohl (prev_fc->last_ack_sent.pid)))
601 {
602 LOG (GNUNET_ERROR_TYPE_DEBUG, " canceling old ACK\n");
603 GCC_cancel (prev_fc->ack_msg);
604 /* GCC_cancel triggers ack_sent(), which clears fc->ack_msg */
605 }
606 else
607 {
608 LOG (GNUNET_ERROR_TYPE_DEBUG, " same ACK already in queue\n");
609 GCC_check_connections ();
610 return;
611 }
612 }
613 GNUNET_break (GC_is_pid_bigger (ntohl (ack_cemi.pid),
614 ntohl (prev_fc->last_ack_sent.pid)));
615 prev_fc->last_ack_sent = ack_cemi;
616
617 /* Build ACK message and send on conn */
618 msg.header.size = htons (sizeof (msg));
619 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CONNECTION_HOP_BY_HOP_ENCRYPTED_ACK);
620 msg.cemi_max = ack_cemi;
621 msg.cid = c->id;
622
623 prev_fc->ack_msg = GCC_send_prebuilt_message (&msg.header,
624 UINT16_MAX,
625 zero,
626 c,
627 !fwd,
628 GNUNET_YES,
629 NULL, NULL);
630 GNUNET_assert (NULL != prev_fc->ack_msg);
631 GCC_check_connections ();
632}
633
634
635/**
636 * Update performance information if we are a connection's endpoint.
637 *
638 * @param c Connection to update.
639 * @param wait How much time did we wait to send the last message.
640 * @param size Size of the last message.
641 */
642static void
643update_perf (struct CadetConnection *c,
644 struct GNUNET_TIME_Relative wait,
645 uint16_t size)
646{
647 struct CadetConnectionPerformance *p;
648 double usecsperbyte;
649
650 if (NULL == c->perf)
651 return; /* Only endpoints are interested in timing. */
652
653 p = c->perf;
654 usecsperbyte = ((double) wait.rel_value_us) / size;
655 if (p->size == AVG_MSGS)
656 {
657 /* Array is full. Substract oldest value, add new one and store. */
658 p->avg -= (p->usecsperbyte[p->idx] / AVG_MSGS);
659 p->usecsperbyte[p->idx] = usecsperbyte;
660 p->avg += (p->usecsperbyte[p->idx] / AVG_MSGS);
661 }
662 else
663 {
664 /* Array not yet full. Add current value to avg and store. */
665 p->usecsperbyte[p->idx] = usecsperbyte;
666 p->avg *= p->size;
667 p->avg += p->usecsperbyte[p->idx];
668 p->size++;
669 p->avg /= p->size;
670 }
671 p->idx = (p->idx + 1) % AVG_MSGS;
672}
673
674
675/**
676 * Callback called when a connection queued message is sent.
677 *
678 * Calculates the average time and connection packet tracking.
679 *
680 * @param cls Closure (ConnectionQueue Handle), can be NULL.
681 * @param c Connection this message was on.
682 * @param fwd Was this a FWD going message?
683 * @param sent Was it really sent? (Could have been canceled)
684 * @param type Type of message sent.
685 * @param payload_type Type of payload, if applicable.
686 * @param pid Message ID, or 0 if not applicable (create, destroy, etc).
687 * @param size Size of the message.
688 * @param wait Time spent waiting for core (only the time for THIS message)
689 */
690static void
691conn_message_sent (void *cls,
692 struct CadetConnection *c,
693 int fwd,
694 int sent,
695 uint16_t type,
696 uint16_t payload_type,
697 struct CadetEncryptedMessageIdentifier pid,
698 size_t size,
699 struct GNUNET_TIME_Relative wait)
700{
701 struct CadetConnectionQueue *q = cls;
702 struct CadetFlowControl *fc;
703 int forced;
704
705 GCC_check_connections ();
706 LOG (GNUNET_ERROR_TYPE_INFO,
707 ">>> %s (%s %4u) on conn %s (%p) %s [%5u] in queue %s\n",
708 GC_m2s (type), GC_m2s (payload_type),
709 ntohl (pid.pid),
710 GCC_2s (c),
711 c,
712 GC_f2s (fwd), size,
713 GNUNET_STRINGS_relative_time_to_string (wait, GNUNET_YES));
714
715 /* If c is NULL, nothing to update. */
716 if (NULL == c)
717 {
718 if (type != GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN
719 && type != GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY)
720 {
721 LOG (GNUNET_ERROR_TYPE_ERROR, "Message %s sent on NULL connection!\n",
722 GC_m2s (type));
723 }
724 GCC_check_connections ();
725 return;
726 }
727
728 LOG (GNUNET_ERROR_TYPE_DEBUG, " %ssent %s %s pid %u\n",
729 sent ? "" : "not ", GC_f2s (fwd),
730 GC_m2s (type), GC_m2s (payload_type),
731 ntohl (pid.pid));
732 GCC_debug (c, GNUNET_ERROR_TYPE_DEBUG);
733
734 /* Update flow control info. */
735 fc = fwd ? &c->fwd_fc : &c->bck_fc;
736
737 if (NULL != q)
738 {
739 GNUNET_CONTAINER_DLL_remove (fc->q_head, fc->q_tail, q);
740 forced = q->forced;
741 if (NULL != q->cont)
742 {
743 LOG (GNUNET_ERROR_TYPE_DEBUG, " calling cont\n");
744 q->cont (q->cont_cls, c, q, type, fwd, size);
745 }
746 GNUNET_free (q);
747 }
748 else /* CONN_CREATE or CONN_ACK */
749 {
750 GNUNET_assert (GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED != type);
751 forced = GNUNET_YES;
752 }
753
754 LOG (GNUNET_ERROR_TYPE_DEBUG, " C_P- %p %u\n", c, c->pending_messages);
755 c->pending_messages--;
756 if ( (GNUNET_YES == c->destroy) &&
757 (0 == c->pending_messages) )
758 {
759 LOG (GNUNET_ERROR_TYPE_DEBUG,
760 "! destroying connection!\n");
761 GCC_destroy (c);
762 GCC_check_connections ();
763 return;
764 }
765
766 /* Send ACK if needed, after accounting for sent ID in fc->queue_n */
767 switch (type)
768 {
769 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE:
770 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE_ACK:
771 c->maintenance_q = NULL;
772 /* Don't trigger a keepalive for sent ACKs, only SYN and SYNACKs */
773 if (GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE == type || !fwd)
774 schedule_next_keepalive (c, fwd);
775 break;
776
777 case GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED:
778 if (GNUNET_YES == sent)
779 {
780 fc->last_pid_sent = pid;
781 if (GC_is_pid_bigger (ntohl (fc->last_pid_sent.pid) + 1,
782 ntohl (fc->last_ack_recv.pid)) )
783 GCC_start_poll (c, fwd);
784 GCC_send_ack (c, fwd, GNUNET_NO);
785 connection_reset_timeout (c, fwd);
786 }
787
788 LOG (GNUNET_ERROR_TYPE_DEBUG, "! Q_N- %p %u\n", fc, fc->queue_n);
789 if (GNUNET_NO == forced)
790 {
791 fc->queue_n--;
792 LOG (GNUNET_ERROR_TYPE_DEBUG,
793 "! accounting pid %u\n",
794 ntohl (fc->last_pid_sent.pid));
795 }
796 else
797 {
798 LOG (GNUNET_ERROR_TYPE_DEBUG,
799 "! forced, Q_N not accounting pid %u\n",
800 ntohl (fc->last_pid_sent.pid));
801 }
802 break;
803
804 case GNUNET_MESSAGE_TYPE_CADET_TUNNEL_KX:
805 if (GNUNET_YES == sent)
806 connection_reset_timeout (c, fwd);
807 break;
808
809 case GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED_POLL:
810 fc->poll_msg = NULL;
811 if (2 == c->destroy)
812 {
813 LOG (GNUNET_ERROR_TYPE_DEBUG, "POLL canceled on shutdown\n");
814 return;
815 }
816 if (0 == fc->queue_max)
817 {
818 LOG (GNUNET_ERROR_TYPE_DEBUG, "POLL cancelled: neighbor disconnected\n");
819 return;
820 }
821 LOG (GNUNET_ERROR_TYPE_DEBUG, "POLL sent for %s, scheduling new one!\n",
822 GCC_2s (c));
823 GNUNET_assert (NULL == fc->poll_task);
824 fc->poll_time = GNUNET_TIME_STD_BACKOFF (fc->poll_time);
825 fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time,
826 &send_poll, fc);
827 LOG (GNUNET_ERROR_TYPE_DEBUG, " task %u\n", fc->poll_task);
828 break;
829
830 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_HOP_BY_HOP_ENCRYPTED_ACK:
831 fc->ack_msg = NULL;
832 break;
833
834 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN:
835 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY:
836 break;
837
838 default:
839 LOG (GNUNET_ERROR_TYPE_ERROR, "%s unknown\n", GC_m2s (type));
840 GNUNET_break (0);
841 break;
842 }
843 LOG (GNUNET_ERROR_TYPE_DEBUG, "! message sent!\n");
844
845 update_perf (c, wait, size);
846 GCC_check_connections ();
847}
848
849
850/**
851 * Get the previous hop in a connection
852 *
853 * @param c Connection.
854 *
855 * @return Previous peer in the connection.
856 */
857static struct CadetPeer *
858get_prev_hop (const struct CadetConnection *c)
859{
860 GNUNET_PEER_Id id;
861
862 if (NULL == c->path)
863 return NULL;
864 LOG (GNUNET_ERROR_TYPE_DEBUG,
865 " get prev hop %s [%u/%u]\n",
866 GCC_2s (c), c->own_pos, c->path->length);
867 if (0 == c->own_pos || c->path->length < 2)
868 id = c->path->peers[0];
869 else
870 id = c->path->peers[c->own_pos - 1];
871
872 LOG (GNUNET_ERROR_TYPE_DEBUG, " ID: %s (%u)\n",
873 GNUNET_i2s (GNUNET_PEER_resolve2 (id)), id);
874
875 return GCP_get_short (id, GNUNET_YES);
876}
877
878
879/**
880 * Get the next hop in a connection
881 *
882 * @param c Connection.
883 *
884 * @return Next peer in the connection.
885 */
886static struct CadetPeer *
887get_next_hop (const struct CadetConnection *c)
888{
889 GNUNET_PEER_Id id;
890
891 if (NULL == c->path)
892 return NULL;
893
894 LOG (GNUNET_ERROR_TYPE_DEBUG, " get next hop %s [%u/%u]\n",
895 GCC_2s (c), c->own_pos, c->path->length);
896 if ((c->path->length - 1) == c->own_pos || c->path->length < 2)
897 id = c->path->peers[c->path->length - 1];
898 else
899 id = c->path->peers[c->own_pos + 1];
900
901 LOG (GNUNET_ERROR_TYPE_DEBUG, " ID: %s (%u)\n",
902 GNUNET_i2s (GNUNET_PEER_resolve2 (id)), id);
903
904 return GCP_get_short (id, GNUNET_YES);
905}
906
907
908/**
909 * Check that the direct neighbours (previous and next hop)
910 * are properly associated with this connection.
911 *
912 * @param c connection to check
913 */
914static void
915check_neighbours (const struct CadetConnection *c)
916{
917 if (NULL == c->path)
918 return; /* nothing to check */
919 GCP_check_connection (get_next_hop (c), c);
920 GCP_check_connection (get_prev_hop (c), c);
921}
922
923
924/**
925 * Helper for #GCC_check_connections(). Calls #check_neighbours().
926 *
927 * @param cls NULL
928 * @param key ignored
929 * @param value the `struct CadetConnection` to check
930 * @return #GNUNET_OK (continue to iterate)
931 */
932static int
933check_connection (void *cls,
934 const struct GNUNET_ShortHashCode *key,
935 void *value)
936{
937 struct CadetConnection *c = value;
938
939 check_neighbours (c);
940 return GNUNET_OK;
941}
942
943
944/**
945 * Check invariants for all connections using #check_neighbours().
946 */
947void
948GCC_check_connections ()
949{
950 if (0 == CHECK_INVARIANTS)
951 return;
952 if (NULL == connections)
953 return;
954 GNUNET_CONTAINER_multishortmap_iterate (connections,
955 &check_connection,
956 NULL);
957}
958
959
960/**
961 * Get the hop in a connection.
962 *
963 * @param c Connection.
964 * @param fwd Next in the FWD direction?
965 *
966 * @return Next peer in the connection.
967 */
968static struct CadetPeer *
969get_hop (struct CadetConnection *c, int fwd)
970{
971 return (fwd) ? get_next_hop (c) : get_prev_hop (c);
972}
973
974
975/**
976 * Get a bit mask for a message received out-of-order.
977 *
978 * @param last_pid_recv Last PID we received prior to the out-of-order.
979 * @param ooo_pid PID of the out-of-order message.
980 */
981static uint32_t
982get_recv_bitmask (struct CadetEncryptedMessageIdentifier last_pid_recv,
983 struct CadetEncryptedMessageIdentifier ooo_pid)
984{
985 // FIXME: should assert that the delta is in range...
986 return 1 << (ntohl (last_pid_recv.pid) - ntohl (ooo_pid.pid));
987}
988
989
990/**
991 * Check is an out-of-order message is ok:
992 * - at most 31 messages behind.
993 * - not duplicate.
994 *
995 * @param last_pid_recv Last in-order PID received.
996 */
997static int
998is_ooo_ok (struct CadetEncryptedMessageIdentifier last_pid_recv,
999 struct CadetEncryptedMessageIdentifier ooo_pid,
1000 uint32_t ooo_bitmap)
1001{
1002 uint32_t mask;
1003
1004 if (GC_is_pid_bigger (ntohl (last_pid_recv.pid) - 31,
1005 ntohl (ooo_pid.pid)))
1006 return GNUNET_NO;
1007
1008 mask = get_recv_bitmask (last_pid_recv,
1009 ooo_pid);
1010 if (0 != (ooo_bitmap & mask))
1011 return GNUNET_NO;
1012
1013 return GNUNET_YES;
1014}
1015
1016
1017/**
1018 * Is traffic coming from this sender 'FWD' traffic?
1019 *
1020 * @param c Connection to check.
1021 * @param sender Short peer identity of neighbor.
1022 *
1023 * @return #GNUNET_YES in case the sender is the 'prev' hop and therefore
1024 * the traffic is 'FWD'.
1025 * #GNUNET_NO for BCK.
1026 * #GNUNET_SYSERR for errors (sender isn't a hop in the connection).
1027 */
1028static int
1029is_fwd (const struct CadetConnection *c,
1030 const struct CadetPeer *sender)
1031{
1032 GNUNET_PEER_Id id;
1033
1034 id = GCP_get_short_id (sender);
1035 if (GCP_get_short_id (get_prev_hop (c)) == id)
1036 return GNUNET_YES;
1037
1038 if (GCP_get_short_id (get_next_hop (c)) == id)
1039 return GNUNET_NO;
1040
1041 return GNUNET_SYSERR;
1042}
1043
1044
1045/**
1046 * Sends a CONNECTION ACK message in reponse to a received CONNECTION_CREATE
1047 * or a first CONNECTION_ACK directed to us.
1048 *
1049 * @param c Connection to confirm.
1050 * @param fwd Should we send it FWD? (root->dest)
1051 * (First (~SYNACK) goes BCK, second (~ACK) goes FWD)
1052 */
1053static void
1054send_connection_ack (struct CadetConnection *c, int fwd)
1055{
1056 static struct CadetEncryptedMessageIdentifier zero;
1057 struct GNUNET_CADET_ConnectionCreateAckMessage msg;
1058 struct CadetTunnel *t;
1059 const uint16_t size = sizeof (struct GNUNET_CADET_ConnectionCreateAckMessage);
1060 const uint16_t type = GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE_ACK;
1061
1062 GCC_check_connections ();
1063 t = c->t;
1064 LOG (GNUNET_ERROR_TYPE_INFO,
1065 "==> %s ({ C %s ACK} 0) on conn %s (%p) %s [%5u]\n",
1066 GC_m2s (type), GC_f2s (!fwd), GCC_2s (c), c, GC_f2s (fwd), size);
1067
1068 msg.header.size = htons (size);
1069 msg.header.type = htons (type);
1070 msg.reserved = htonl (0);
1071 msg.cid = c->id;
1072
1073 GNUNET_assert (NULL == c->maintenance_q);
1074 c->maintenance_q = GCP_send (get_hop (c, fwd),
1075 &msg.header,
1076 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE_ACK,
1077 zero,
1078 c,
1079 fwd,
1080 &conn_message_sent, NULL);
1081 LOG (GNUNET_ERROR_TYPE_DEBUG, " C_P+ %p %u (conn`ACK)\n",
1082 c, c->pending_messages);
1083 c->pending_messages++;
1084
1085 if (CADET_TUNNEL_NEW == GCT_get_cstate (t))
1086 GCT_change_cstate (t, CADET_TUNNEL_WAITING);
1087 if (CADET_CONNECTION_READY != c->state)
1088 connection_change_state (c, CADET_CONNECTION_SENT);
1089 GCC_check_connections ();
1090}
1091
1092
1093/**
1094 * Send a notification that a connection is broken.
1095 *
1096 * @param c Connection that is broken.
1097 * @param id1 Peer that has disconnected.
1098 * @param id2 Peer that has disconnected.
1099 * @param fwd Direction towards which to send it.
1100 */
1101static void
1102send_broken (struct CadetConnection *c,
1103 const struct GNUNET_PeerIdentity *id1,
1104 const struct GNUNET_PeerIdentity *id2,
1105 int fwd)
1106{
1107 static struct CadetEncryptedMessageIdentifier zero;
1108 struct GNUNET_CADET_ConnectionBrokenMessage msg;
1109
1110 GCC_check_connections ();
1111 msg.header.size = htons (sizeof (struct GNUNET_CADET_ConnectionBrokenMessage));
1112 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN);
1113 msg.cid = c->id;
1114 msg.reserved = htonl (0);
1115 msg.peer1 = *id1;
1116 msg.peer2 = *id2;
1117 (void) GCC_send_prebuilt_message (&msg.header,
1118 UINT16_MAX,
1119 zero,
1120 c,
1121 fwd,
1122 GNUNET_YES,
1123 NULL, NULL);
1124 GCC_check_connections ();
1125}
1126
1127
1128/**
1129 * Send a notification that a connection is broken, when a connection
1130 * isn't even known to the local peer or soon to be destroyed.
1131 *
1132 * @param connection_id Connection ID.
1133 * @param id1 Peer that has disconnected, probably local peer.
1134 * @param id2 Peer that has disconnected can be NULL if unknown.
1135 * @param neighbor Peer to notify (neighbor who sent the connection).
1136 */
1137static void
1138send_broken_unknown (const struct GNUNET_CADET_ConnectionTunnelIdentifier *connection_id,
1139 const struct GNUNET_PeerIdentity *id1,
1140 const struct GNUNET_PeerIdentity *id2,
1141 struct CadetPeer *neighbor)
1142{
1143 static struct CadetEncryptedMessageIdentifier zero;
1144 struct GNUNET_CADET_ConnectionBrokenMessage msg;
1145
1146 GCC_check_connections ();
1147 LOG (GNUNET_ERROR_TYPE_INFO, "--> BROKEN on unknown connection %s\n",
1148 GNUNET_sh2s (&connection_id->connection_of_tunnel));
1149
1150 msg.header.size = htons (sizeof (struct GNUNET_CADET_ConnectionBrokenMessage));
1151 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN);
1152 msg.cid = *connection_id;
1153 msg.reserved = htonl (0);
1154 msg.peer1 = *id1;
1155 if (NULL != id2)
1156 msg.peer2 = *id2;
1157 else
1158 memset (&msg.peer2, 0, sizeof (msg.peer2));
1159 GNUNET_assert (NULL != GCP_send (neighbor,
1160 &msg.header,
1161 UINT16_MAX,
1162 zero,
1163 NULL,
1164 GNUNET_SYSERR, /* connection, fwd */
1165 NULL, NULL)); /* continuation */
1166 GCC_check_connections ();
1167}
1168
1169
1170/**
1171 * Send keepalive packets for a connection.
1172 *
1173 * @param c Connection to keep alive..
1174 * @param fwd Is this a FWD keepalive? (owner -> dest).
1175 */
1176static void
1177send_connection_keepalive (struct CadetConnection *c, int fwd)
1178{
1179 struct GNUNET_MessageHeader msg;
1180 struct CadetFlowControl *fc;
1181 int tunnel_ready;
1182
1183 GCC_check_connections ();
1184 LOG (GNUNET_ERROR_TYPE_INFO,
1185 "keepalive %s for connection %s\n",
1186 GC_f2s (fwd), GCC_2s (c));
1187
1188 GNUNET_assert (NULL != c->t);
1189 fc = fwd ? &c->fwd_fc : &c->bck_fc;
1190 tunnel_ready = GNUNET_YES == GCT_has_queued_traffic (c->t)
1191 && CADET_TUNNEL_KEY_OK <= GCT_get_estate (c->t);
1192 if (0 < fc->queue_n || tunnel_ready)
1193 {
1194 LOG (GNUNET_ERROR_TYPE_INFO, "not sending keepalive, traffic in queue\n");
1195 return;
1196 }
1197
1198 GNUNET_STATISTICS_update (stats, "# keepalives sent", 1, GNUNET_NO);
1199
1200 GNUNET_assert (NULL != c->t);
1201 msg.size = htons (sizeof (msg));
1202 msg.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_KEEPALIVE);
1203
1204 GNUNET_assert (NULL ==
1205 GCT_send_prebuilt_message (&msg, c->t, c,
1206 GNUNET_NO, NULL, NULL));
1207 GCC_check_connections ();
1208}
1209
1210
1211/**
1212 * Send CONNECTION_{CREATE/ACK} packets for a connection.
1213 *
1214 * @param c Connection for which to send the message.
1215 * @param fwd If #GNUNET_YES, send CREATE, otherwise send ACK.
1216 */
1217static void
1218connection_recreate (struct CadetConnection *c, int fwd)
1219{
1220 LOG (GNUNET_ERROR_TYPE_DEBUG,
1221 "sending connection recreate\n");
1222 if (fwd)
1223 GCC_send_create (c);
1224 else
1225 send_connection_ack (c, GNUNET_NO);
1226}
1227
1228
1229/**
1230 * Generic connection timer management.
1231 * Depending on the role of the peer in the connection will send the
1232 * appropriate message (build or keepalive)
1233 *
1234 * @param c Conncetion to maintain.
1235 * @param fwd Is FWD?
1236 */
1237static void
1238connection_maintain (struct CadetConnection *c, int fwd)
1239{
1240 if (GNUNET_NO != c->destroy)
1241 {
1242 LOG (GNUNET_ERROR_TYPE_INFO, "not sending keepalive, being destroyed\n");
1243 return;
1244 }
1245
1246 if (NULL == c->t)
1247 {
1248 GNUNET_break (0);
1249 GCC_debug (c, GNUNET_ERROR_TYPE_ERROR);
1250 return;
1251 }
1252
1253 if (CADET_TUNNEL_SEARCHING == GCT_get_cstate (c->t))
1254 {
1255 /* If status is SEARCHING, why is there a connection? Should be WAITING */
1256 GNUNET_break (0);
1257 GCT_debug (c->t, GNUNET_ERROR_TYPE_ERROR);
1258 LOG (GNUNET_ERROR_TYPE_INFO, "not sending keepalive, tunnel SEARCHING\n");
1259 schedule_next_keepalive (c, fwd);
1260 return;
1261 }
1262 switch (c->state)
1263 {
1264 case CADET_CONNECTION_NEW:
1265 GNUNET_break (0);
1266 /* fall-through */
1267 case CADET_CONNECTION_SENT:
1268 connection_recreate (c, fwd);
1269 break;
1270 case CADET_CONNECTION_READY:
1271 send_connection_keepalive (c, fwd);
1272 break;
1273 default:
1274 break;
1275 }
1276}
1277
1278
1279/**
1280 * Keep the connection alive.
1281 *
1282 * @param c Connection to keep alive.
1283 * @param fwd Direction.
1284 */
1285static void
1286connection_keepalive (struct CadetConnection *c,
1287 int fwd)
1288{
1289 GCC_check_connections ();
1290 LOG (GNUNET_ERROR_TYPE_DEBUG,
1291 "%s keepalive for %s\n",
1292 GC_f2s (fwd), GCC_2s (c));
1293
1294 if (fwd)
1295 c->fwd_maintenance_task = NULL;
1296 else
1297 c->bck_maintenance_task = NULL;
1298 connection_maintain (c, fwd);
1299 GCC_check_connections ();
1300 /* Next execution will be scheduled by message_sent or _maintain*/
1301}
1302
1303
1304/**
1305 * Keep the connection alive in the FWD direction.
1306 *
1307 * @param cls Closure (connection to keepalive).
1308 */
1309static void
1310connection_fwd_keepalive (void *cls)
1311{
1312 struct CadetConnection *c = cls;
1313
1314 GCC_check_connections ();
1315 connection_keepalive (c,
1316 GNUNET_YES);
1317 GCC_check_connections ();
1318}
1319
1320
1321/**
1322 * Keep the connection alive in the BCK direction.
1323 *
1324 * @param cls Closure (connection to keepalive).
1325 */
1326static void
1327connection_bck_keepalive (void *cls)
1328{
1329 struct CadetConnection *c = cls;
1330
1331 GCC_check_connections ();
1332 connection_keepalive (c,
1333 GNUNET_NO);
1334 GCC_check_connections ();
1335}
1336
1337
1338/**
1339 * Schedule next keepalive task, taking in consideration
1340 * the connection state and number of retries.
1341 *
1342 * If the peer is not the origin, do nothing.
1343 *
1344 * @param c Connection for which to schedule the next keepalive.
1345 * @param fwd Direction for the next keepalive.
1346 */
1347static void
1348schedule_next_keepalive (struct CadetConnection *c, int fwd)
1349{
1350 struct GNUNET_TIME_Relative delay;
1351 struct GNUNET_SCHEDULER_Task * *task_id;
1352 GNUNET_SCHEDULER_TaskCallback keepalive_task;
1353
1354 GCC_check_connections ();
1355 if (GNUNET_NO == GCC_is_origin (c, fwd))
1356 return;
1357
1358 /* Calculate delay to use, depending on the state of the connection */
1359 if (CADET_CONNECTION_READY == c->state)
1360 {
1361 delay = refresh_connection_time;
1362 }
1363 else
1364 {
1365 if (1 > c->create_retry)
1366 c->create_retry = 1;
1367 delay = GNUNET_TIME_relative_saturating_multiply (create_connection_time,
1368 c->create_retry);
1369 if (c->create_retry < 64) // TODO make configurable
1370 c->create_retry *= 2;
1371 }
1372
1373 /* Select direction-dependent parameters */
1374 if (GNUNET_YES == fwd)
1375 {
1376 task_id = &c->fwd_maintenance_task;
1377 keepalive_task = &connection_fwd_keepalive;
1378 }
1379 else
1380 {
1381 task_id = &c->bck_maintenance_task;
1382 keepalive_task = &connection_bck_keepalive;
1383 }
1384
1385 /* Check that no one scheduled it before us */
1386 if (NULL != *task_id)
1387 {
1388 /* No need for a _break. It can happen for instance when sending a SYNACK
1389 * for a duplicate SYN: the first SYNACK scheduled the task. */
1390 GNUNET_SCHEDULER_cancel (*task_id);
1391 }
1392
1393 /* Schedule the task */
1394 *task_id = GNUNET_SCHEDULER_add_delayed (delay,
1395 keepalive_task,
1396 c);
1397 LOG (GNUNET_ERROR_TYPE_INFO,
1398 "next keepalive for %s in in %s\n",
1399 GCC_2s (c), GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
1400 GCC_check_connections ();
1401}
1402
1403
1404/**
1405 * Cancel all transmissions that belong to a certain connection.
1406 *
1407 * If the connection is scheduled for destruction and no more messages are left,
1408 * the connection will be destroyed by the continuation call.
1409 *
1410 * @param c Connection which to cancel. Might be destroyed during this call.
1411 * @param fwd Cancel fwd traffic?
1412 */
1413static void
1414connection_cancel_queues (struct CadetConnection *c,
1415 int fwd)
1416{
1417 struct CadetFlowControl *fc;
1418
1419 GCC_check_connections ();
1420 LOG (GNUNET_ERROR_TYPE_DEBUG,
1421 "Cancel %s queues for connection %s\n",
1422 GC_f2s (fwd), GCC_2s (c));
1423 if (NULL == c)
1424 {
1425 GNUNET_break (0);
1426 return;
1427 }
1428
1429 fc = fwd ? &c->fwd_fc : &c->bck_fc;
1430 if (NULL != fc->poll_task)
1431 {
1432 GNUNET_SCHEDULER_cancel (fc->poll_task);
1433 fc->poll_task = NULL;
1434 LOG (GNUNET_ERROR_TYPE_DEBUG, " cancelled POLL task for fc %p\n", fc);
1435 }
1436 if (NULL != fc->poll_msg)
1437 {
1438 GCC_cancel (fc->poll_msg);
1439 LOG (GNUNET_ERROR_TYPE_DEBUG, " cancelled POLL msg for fc %p\n", fc);
1440 }
1441
1442 while (NULL != fc->q_head)
1443 {
1444 GCC_cancel (fc->q_head);
1445 }
1446 GCC_check_connections ();
1447}
1448
1449
1450/**
1451 * Function called if a connection has been stalled for a while,
1452 * possibly due to a missed ACK. Poll the neighbor about its ACK status.
1453 *
1454 * @param cls Closure (poll ctx).
1455 */
1456static void
1457send_poll (void *cls)
1458{
1459 static struct CadetEncryptedMessageIdentifier zero;
1460 struct CadetFlowControl *fc = cls;
1461 struct GNUNET_CADET_ConnectionHopByHopPollMessage msg;
1462 struct CadetConnection *c;
1463 int fwd;
1464
1465 fc->poll_task = NULL;
1466 GCC_check_connections ();
1467 c = fc->c;
1468 fwd = fc == &c->fwd_fc;
1469 LOG (GNUNET_ERROR_TYPE_DEBUG, "Polling connection %s %s\n",
1470 GCC_2s (c), GC_f2s (fwd));
1471
1472 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED_POLL);
1473 msg.header.size = htons (sizeof (msg));
1474 msg.cid = c->id;
1475 msg.cemi = fc->last_pid_sent;
1476 LOG (GNUNET_ERROR_TYPE_DEBUG, " last pid sent: %u\n", ntohl (fc->last_pid_sent.pid));
1477 fc->poll_msg
1478 = GCC_send_prebuilt_message (&msg.header,
1479 UINT16_MAX,
1480 zero,
1481 c,
1482 fc == &c->fwd_fc,
1483 GNUNET_YES,
1484 NULL,
1485 NULL);
1486 GNUNET_assert (NULL != fc->poll_msg);
1487 GCC_check_connections ();
1488}
1489
1490
1491/**
1492 * Generic connection timeout implementation.
1493 *
1494 * Timeout function due to lack of keepalive/traffic from an endpoint.
1495 * Destroys connection if called.
1496 *
1497 * @param c Connection to destroy.
1498 * @param fwd Was the timeout from the origin? (FWD timeout)
1499 */
1500static void
1501connection_timeout (struct CadetConnection *c, int fwd)
1502{
1503 GCC_check_connections ();
1504
1505 LOG (GNUNET_ERROR_TYPE_INFO,
1506 "Connection %s %s timed out. Destroying.\n",
1507 GCC_2s (c),
1508 GC_f2s (fwd));
1509 GCC_debug (c, GNUNET_ERROR_TYPE_DEBUG);
1510
1511 if (GCC_is_origin (c, fwd)) /* Loopback? Something is wrong! */
1512 {
1513 GNUNET_break (0);
1514 return;
1515 }
1516
1517 /* If dest, send "broken" notification. */
1518 if (GCC_is_terminal (c, fwd))
1519 {
1520 struct CadetPeer *next_hop;
1521
1522 next_hop = fwd ? get_prev_hop (c) : get_next_hop (c);
1523 send_broken_unknown (&c->id, &my_full_id, NULL, next_hop);
1524 }
1525
1526 GCC_destroy (c);
1527 GCC_check_connections ();
1528}
1529
1530
1531/**
1532 * Timeout function due to lack of keepalive/traffic from the owner.
1533 * Destroys connection if called.
1534 *
1535 * @param cls Closure (connection to destroy).
1536 */
1537static void
1538connection_fwd_timeout (void *cls)
1539{
1540 struct CadetConnection *c = cls;
1541
1542 c->fwd_maintenance_task = NULL;
1543 GCC_check_connections ();
1544 connection_timeout (c, GNUNET_YES);
1545 GCC_check_connections ();
1546}
1547
1548
1549/**
1550 * Timeout function due to lack of keepalive/traffic from the destination.
1551 * Destroys connection if called.
1552 *
1553 * @param cls Closure (connection to destroy).
1554 */
1555static void
1556connection_bck_timeout (void *cls)
1557{
1558 struct CadetConnection *c = cls;
1559
1560 c->bck_maintenance_task = NULL;
1561 GCC_check_connections ();
1562 connection_timeout (c, GNUNET_NO);
1563 GCC_check_connections ();
1564}
1565
1566
1567/**
1568 * Resets the connection timeout task, some other message has done the
1569 * task's job.
1570 * - For the first peer on the direction this means to send
1571 * a keepalive or a path confirmation message (either create or ACK).
1572 * - For all other peers, this means to destroy the connection,
1573 * due to lack of activity.
1574 * Starts the timeout if no timeout was running (connection just created).
1575 *
1576 * @param c Connection whose timeout to reset.
1577 * @param fwd Is this forward?
1578 *
1579 * TODO use heap to improve efficiency of scheduler.
1580 */
1581static void
1582connection_reset_timeout (struct CadetConnection *c, int fwd)
1583{
1584 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s reset timeout\n", GC_f2s (fwd));
1585 if (GCC_is_origin (c, fwd)) /* Startpoint */
1586 {
1587 schedule_next_keepalive (c, fwd);
1588 if (NULL != c->maintenance_q)
1589 {
1590 GCP_send_cancel (c->maintenance_q);
1591 c->maintenance_q = NULL; /* Is set to NULL by conn_message_sent anyway */
1592 }
1593 }
1594 else /* Relay, endpoint. */
1595 {
1596 struct GNUNET_TIME_Relative delay;
1597 struct GNUNET_SCHEDULER_Task * *ti;
1598 GNUNET_SCHEDULER_TaskCallback f;
1599
1600 ti = fwd ? &c->fwd_maintenance_task : &c->bck_maintenance_task;
1601
1602 if (NULL != *ti)
1603 GNUNET_SCHEDULER_cancel (*ti);
1604 delay = GNUNET_TIME_relative_saturating_multiply (refresh_connection_time, 4);
1605 LOG (GNUNET_ERROR_TYPE_DEBUG,
1606 " timing out in %s\n",
1607 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_NO));
1608 f = fwd ? &connection_fwd_timeout : &connection_bck_timeout;
1609 *ti = GNUNET_SCHEDULER_add_delayed (delay, f, c);
1610 }
1611}
1612
1613
1614/**
1615 * Iterator to compare each connection's path with the path of a new connection.
1616 *
1617 * If the connection coincides, the c member of path is set to the connection
1618 * and the destroy flag of the connection is set.
1619 *
1620 * @param cls Closure (new path).
1621 * @param c Connection in the tunnel to check.
1622 */
1623static void
1624check_path (void *cls, struct CadetConnection *c)
1625{
1626 struct CadetConnection *new_conn = cls;
1627 struct CadetPeerPath *path = new_conn->path;
1628
1629 LOG (GNUNET_ERROR_TYPE_DEBUG, " checking %s (%p), length %u\n",
1630 GCC_2s (c), c, c->path->length);
1631
1632 if (c != new_conn
1633 && GNUNET_NO == c->destroy
1634 && CADET_CONNECTION_BROKEN != c->state
1635 && CADET_CONNECTION_DESTROYED != c->state
1636 && path_equivalent (path, c->path))
1637 {
1638 new_conn->destroy = GNUNET_YES; /* Do not mark_destroyed, */
1639 new_conn->path->c = c; /* this is only a flag for the Iterator. */
1640 LOG (GNUNET_ERROR_TYPE_DEBUG, " MATCH!\n");
1641 }
1642}
1643
1644
1645/**
1646 * Finds out if this path is already being used by an existing connection.
1647 *
1648 * Checks the tunnel towards the destination to see if it contains
1649 * any connection with the same path.
1650 *
1651 * If the existing connection is ready, it is kept.
1652 * Otherwise if the sender has a smaller ID that ours, we accept it (and
1653 * the peer will eventually reject our attempt).
1654 *
1655 * @param path Path to check.
1656 * @return #GNUNET_YES if the tunnel has a connection with the same path,
1657 * #GNUNET_NO otherwise.
1658 */
1659static int
1660does_connection_exist (struct CadetConnection *conn)
1661{
1662 struct CadetPeer *p;
1663 struct CadetTunnel *t;
1664 struct CadetConnection *c;
1665
1666 p = GCP_get_short (conn->path->peers[0], GNUNET_NO);
1667 if (NULL == p)
1668 return GNUNET_NO;
1669 t = GCP_get_tunnel (p);
1670 if (NULL == t)
1671 return GNUNET_NO;
1672
1673 LOG (GNUNET_ERROR_TYPE_DEBUG, "Checking for duplicates\n");
1674
1675 GCT_iterate_connections (t, &check_path, conn);
1676
1677 if (GNUNET_YES == conn->destroy)
1678 {
1679 c = conn->path->c;
1680 conn->destroy = GNUNET_NO;
1681 conn->path->c = conn;
1682 LOG (GNUNET_ERROR_TYPE_DEBUG, " found duplicate of %s\n", GCC_2s (conn));
1683 LOG (GNUNET_ERROR_TYPE_DEBUG, " duplicate: %s\n", GCC_2s (c));
1684 GCC_debug (c, GNUNET_ERROR_TYPE_DEBUG);
1685 if (CADET_CONNECTION_READY == c->state)
1686 {
1687 /* The other peer confirmed a live connection with this path,
1688 * why are they trying to duplicate it? */
1689 GNUNET_STATISTICS_update (stats, "# duplicate connections", 1, GNUNET_NO);
1690 return GNUNET_YES;
1691 }
1692 LOG (GNUNET_ERROR_TYPE_DEBUG, " duplicate not ready, connection unique\n");
1693 return GNUNET_NO;
1694 }
1695 else
1696 {
1697 LOG (GNUNET_ERROR_TYPE_DEBUG, " %s has no duplicates\n", GCC_2s (conn));
1698 return GNUNET_NO;
1699 }
1700}
1701
1702
1703/**
1704 * @brief Check if the tunnel this connection belongs to has any other
1705 * connection with the same path, and destroy one if so.
1706 *
1707 * @param cls Closure (connection to check).
1708 */
1709static void
1710check_duplicates (void *cls)
1711{
1712 struct CadetConnection *c = cls;
1713
1714 c->check_duplicates_task = NULL;
1715 if (GNUNET_YES == does_connection_exist (c))
1716 {
1717 GCT_debug (c->t, GNUNET_ERROR_TYPE_DEBUG);
1718 send_broken (c, &my_full_id, &my_full_id, GCC_is_origin (c, GNUNET_YES));
1719 GCC_destroy (c);
1720 }
1721}
1722
1723
1724/**
1725 * Wait for enough time to let any dead connections time out and check for
1726 * any remaining duplicates.
1727 *
1728 * @param c Connection that is a potential duplicate.
1729 */
1730static void
1731schedule_check_duplicates (struct CadetConnection *c)
1732{
1733 struct GNUNET_TIME_Relative delay;
1734
1735 if (NULL != c->check_duplicates_task)
1736 return;
1737 delay = GNUNET_TIME_relative_saturating_multiply (refresh_connection_time, 5);
1738 c->check_duplicates_task = GNUNET_SCHEDULER_add_delayed (delay,
1739 &check_duplicates,
1740 c);
1741}
1742
1743
1744/**
1745 * Add the connection to the list of both neighbors.
1746 *
1747 * @param c Connection.
1748 *
1749 * @return #GNUNET_OK if everything went fine
1750 * #GNUNET_SYSERR if the was an error and @c c is malformed.
1751 */
1752static int
1753register_neighbors (struct CadetConnection *c)
1754{
1755 c->next_peer = get_next_hop (c);
1756 c->prev_peer = get_prev_hop (c);
1757 GNUNET_assert (c->next_peer != c->prev_peer);
1758 LOG (GNUNET_ERROR_TYPE_DEBUG,
1759 "register neighbors for connection %s\n",
1760 GCC_2s (c));
1761 path_debug (c->path);
1762 LOG (GNUNET_ERROR_TYPE_DEBUG,
1763 "own pos %u\n", c->own_pos);
1764 LOG (GNUNET_ERROR_TYPE_DEBUG,
1765 "putting connection %s to next peer %p\n",
1766 GCC_2s (c),
1767 c->next_peer);
1768 LOG (GNUNET_ERROR_TYPE_DEBUG, "next peer %p %s\n",
1769 c->next_peer,
1770 GCP_2s (c->next_peer));
1771 LOG (GNUNET_ERROR_TYPE_DEBUG,
1772 "putting connection %s to prev peer %p\n",
1773 GCC_2s (c),
1774 c->prev_peer);
1775 LOG (GNUNET_ERROR_TYPE_DEBUG,
1776 "prev peer %p %s\n",
1777 c->prev_peer,
1778 GCP_2s (c->prev_peer));
1779
1780 if ( (GNUNET_NO == GCP_is_neighbor (c->next_peer)) ||
1781 (GNUNET_NO == GCP_is_neighbor (c->prev_peer)) )
1782 {
1783 if (GCC_is_origin (c, GNUNET_YES))
1784 GNUNET_STATISTICS_update (stats, "# local bad paths", 1, GNUNET_NO);
1785 GNUNET_STATISTICS_update (stats, "# bad paths", 1, GNUNET_NO);
1786
1787 LOG (GNUNET_ERROR_TYPE_DEBUG,
1788 " register neighbors failed\n");
1789 LOG (GNUNET_ERROR_TYPE_DEBUG,
1790 " prev: %s, neighbor?: %d\n",
1791 GCP_2s (c->prev_peer),
1792 GCP_is_neighbor (c->prev_peer));
1793 LOG (GNUNET_ERROR_TYPE_DEBUG,
1794 " next: %s, neighbor?: %d\n",
1795 GCP_2s (c->next_peer),
1796 GCP_is_neighbor (c->next_peer));
1797 return GNUNET_SYSERR;
1798 }
1799 GCP_add_connection (c->next_peer, c, GNUNET_NO);
1800 GCP_add_connection (c->prev_peer, c, GNUNET_YES);
1801
1802 return GNUNET_OK;
1803}
1804
1805
1806/**
1807 * Remove the connection from the list of both neighbors.
1808 *
1809 * @param c Connection.
1810 */
1811static void
1812unregister_neighbors (struct CadetConnection *c)
1813{
1814// struct CadetPeer *peer; FIXME dont use next_peer, prev_peer
1815 /* Either already unregistered or never got registered, it's ok either way. */
1816 if (NULL == c->path)
1817 return;
1818 if (NULL != c->next_peer)
1819 {
1820 GCP_remove_connection (c->next_peer, c);
1821 c->next_peer = NULL;
1822 }
1823 if (NULL != c->prev_peer)
1824 {
1825 GCP_remove_connection (c->prev_peer, c);
1826 c->prev_peer = NULL;
1827 }
1828}
1829
1830
1831/**
1832 * Invalidates all paths towards all peers that comprise the connection which
1833 * rely on the disconnected peer.
1834 *
1835 * ~O(n^3) (peers in connection * paths/peer * links/path)
1836 *
1837 * @param c Connection whose peers' paths to clean.
1838 * @param disconnected Peer that disconnected.
1839 */
1840static void
1841invalidate_paths (struct CadetConnection *c,
1842 struct CadetPeer *disconnected)
1843{
1844 struct CadetPeer *peer;
1845 unsigned int i;
1846
1847 for (i = 0; i < c->path->length; i++)
1848 {
1849 peer = GCP_get_short (c->path->peers[i], GNUNET_NO);
1850 if (NULL != peer)
1851 GCP_notify_broken_link (peer, &my_full_id, GCP_get_id (disconnected));
1852 }
1853}
1854
1855
1856/**
1857 * Bind the connection to the peer and the tunnel to that peer.
1858 *
1859 * If the peer has no tunnel, create one. Update tunnel and connection
1860 * data structres to reflect new status.
1861 *
1862 * @param c Connection.
1863 * @param peer Peer.
1864 */
1865static void
1866add_to_peer (struct CadetConnection *c,
1867 struct CadetPeer *peer)
1868{
1869 GCP_add_tunnel (peer);
1870 c->t = GCP_get_tunnel (peer);
1871 GCT_add_connection (c->t, c);
1872}
1873
1874
1875/**
1876 * Log receipt of message on stderr (INFO level).
1877 *
1878 * @param message Message received.
1879 * @param peer Peer who sent the message.
1880 * @param conn_id Connection ID of the message.
1881 */
1882static void
1883log_message (const struct GNUNET_MessageHeader *message,
1884 const struct CadetPeer *peer,
1885 const struct GNUNET_CADET_ConnectionTunnelIdentifier *conn_id)
1886{
1887 uint16_t size;
1888 uint16_t type;
1889 char *arrow;
1890
1891 size = ntohs (message->size);
1892 type = ntohs (message->type);
1893 switch (type)
1894 {
1895 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE:
1896 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE_ACK:
1897 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN:
1898 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY:
1899 arrow = "==";
1900 break;
1901 default:
1902 arrow = "--";
1903 }
1904 LOG (GNUNET_ERROR_TYPE_INFO,
1905 "<%s %s on conn %s from %s, %6u bytes\n",
1906 arrow,
1907 GC_m2s (type),
1908 GNUNET_sh2s (&conn_id->connection_of_tunnel),
1909 GCP_2s(peer),
1910 (unsigned int) size);
1911}
1912
1913/******************************************************************************/
1914/******************************** API ***********************************/
1915/******************************************************************************/
1916
1917/**
1918 * Handler for connection creation.
1919 *
1920 * @param peer Message sender (neighbor).
1921 * @param msg Message itself.
1922 */
1923void
1924GCC_handle_create (struct CadetPeer *peer,
1925 const struct GNUNET_CADET_ConnectionCreateMessage *msg)
1926{
1927 static struct CadetEncryptedMessageIdentifier zero;
1928 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid;
1929 struct GNUNET_PeerIdentity *id;
1930 struct CadetPeerPath *path;
1931 struct CadetPeer *dest_peer;
1932 struct CadetPeer *orig_peer;
1933 struct CadetConnection *c;
1934 unsigned int own_pos;
1935 uint16_t size;
1936
1937 GCC_check_connections ();
1938 size = ntohs (msg->header.size);
1939
1940 /* Calculate hops */
1941 size -= sizeof (struct GNUNET_CADET_ConnectionCreateMessage);
1942 if (0 != size % sizeof (struct GNUNET_PeerIdentity))
1943 {
1944 GNUNET_break_op (0);
1945 return;
1946 }
1947 size /= sizeof (struct GNUNET_PeerIdentity);
1948 if (1 > size)
1949 {
1950 GNUNET_break_op (0);
1951 return;
1952 }
1953 LOG (GNUNET_ERROR_TYPE_DEBUG, " path has %u hops.\n", size);
1954
1955 /* Get parameters */
1956 cid = &msg->cid;
1957 log_message (&msg->header, peer, cid);
1958 id = (struct GNUNET_PeerIdentity *) &msg[1];
1959 LOG (GNUNET_ERROR_TYPE_DEBUG, " origin: %s\n", GNUNET_i2s (id));
1960
1961 /* Create connection */
1962 c = connection_get (cid);
1963 if (NULL == c)
1964 {
1965 path = path_build_from_peer_ids ((struct GNUNET_PeerIdentity *) &msg[1],
1966 size, myid, &own_pos);
1967 if (NULL == path)
1968 {
1969 /* Path was malformed, probably our own ID was not in it. */
1970 GNUNET_STATISTICS_update (stats, "# malformed paths", 1, GNUNET_NO);
1971 GNUNET_break_op (0);
1972 return;
1973 }
1974 if (0 == own_pos)
1975 {
1976 /* We received this request from a neighbor, we cannot be origin */
1977 GNUNET_STATISTICS_update (stats, "# fake paths", 1, GNUNET_NO);
1978 GNUNET_break_op (0);
1979 path_destroy (path);
1980 return;
1981 }
1982
1983 LOG (GNUNET_ERROR_TYPE_DEBUG, " Own position: %u\n", own_pos);
1984 LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating connection\n");
1985 c = GCC_new (cid, NULL, path, own_pos);
1986 if (NULL == c)
1987 {
1988 if (path->length - 1 == own_pos)
1989 {
1990 /* If we are destination, why did the creation fail? */
1991 GNUNET_break (0);
1992 path_destroy (path);
1993 GCC_check_connections ();
1994 return;
1995 }
1996 send_broken_unknown (cid, &my_full_id,
1997 GNUNET_PEER_resolve2 (path->peers[own_pos + 1]),
1998 peer);
1999 path_destroy (path);
2000 GCC_check_connections ();
2001 return;
2002 }
2003 GCP_add_path_to_all (path, GNUNET_NO);
2004 connection_reset_timeout (c, GNUNET_YES);
2005 }
2006 else
2007 {
2008 path = path_duplicate (c->path);
2009 }
2010 if (CADET_CONNECTION_NEW == c->state)
2011 connection_change_state (c, CADET_CONNECTION_SENT);
2012
2013 /* Remember peers */
2014 dest_peer = GCP_get (&id[size - 1], GNUNET_YES);
2015 orig_peer = GCP_get (&id[0], GNUNET_YES);
2016
2017 /* Is it a connection to us? */
2018 if (c->own_pos == path->length - 1)
2019 {
2020 LOG (GNUNET_ERROR_TYPE_DEBUG, " It's for us!\n");
2021 GCP_add_path_to_origin (orig_peer, path_duplicate (path), GNUNET_YES);
2022
2023 add_to_peer (c, orig_peer);
2024 if (GNUNET_YES == does_connection_exist (c))
2025 {
2026 /* Peer created a connection equal to one we think exists
2027 * and is fine.
2028 * Solution: Keep both and postpone disambiguation. In the meantime
2029 * the connection will time out or peer will inform us it is broken.
2030 *
2031 * Other options:
2032 * - Use explicit duplicate.
2033 * - Accept new conn and destroy the old. (interruption in higher level)
2034 * - Keep the one with higher ID / created by peer with higher ID. */
2035 schedule_check_duplicates (c);
2036 }
2037
2038 if (CADET_TUNNEL_NEW == GCT_get_cstate (c->t))
2039 GCT_change_cstate (c->t, CADET_TUNNEL_WAITING);
2040 if (NULL == c->maintenance_q)
2041 send_connection_ack (c, GNUNET_NO);
2042 if (CADET_CONNECTION_SENT == c->state)
2043 connection_change_state (c, CADET_CONNECTION_ACK);
2044 }
2045 else
2046 {
2047 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
2048 GCP_add_path (dest_peer, path_duplicate (path), GNUNET_NO);
2049 GCP_add_path_to_origin (orig_peer, path_duplicate (path), GNUNET_NO);
2050 (void) GCC_send_prebuilt_message (&msg->header,
2051 0,
2052 zero,
2053 c,
2054 GNUNET_YES, GNUNET_YES,
2055 NULL, NULL);
2056 }
2057 path_destroy (path);
2058 GCC_check_connections ();
2059}
2060
2061
2062/**
2063 * Handler for connection confirmations.
2064 *
2065 * @param peer Message sender (neighbor).
2066 * @param msg Message itself.
2067 */
2068void
2069GCC_handle_confirm (struct CadetPeer *peer,
2070 const struct GNUNET_CADET_ConnectionCreateAckMessage *msg)
2071{
2072 static struct CadetEncryptedMessageIdentifier zero;
2073 struct CadetConnection *c;
2074 enum CadetConnectionState oldstate;
2075 int fwd;
2076
2077 GCC_check_connections ();
2078 log_message (&msg->header, peer, &msg->cid);
2079 c = connection_get (&msg->cid);
2080 if (NULL == c)
2081 {
2082 GNUNET_STATISTICS_update (stats, "# control on unknown connection",
2083 1, GNUNET_NO);
2084 LOG (GNUNET_ERROR_TYPE_DEBUG,
2085 " don't know the connection!\n");
2086 send_broken_unknown (&msg->cid, &my_full_id, NULL, peer);
2087 GCC_check_connections ();
2088 return;
2089 }
2090 if (GNUNET_NO != c->destroy)
2091 {
2092 GNUNET_assert (CADET_CONNECTION_DESTROYED == c->state);
2093 GNUNET_STATISTICS_update (stats, "# control on dying connection",
2094 1, GNUNET_NO);
2095 LOG (GNUNET_ERROR_TYPE_DEBUG,
2096 "connection %s being destroyed, ignoring confirm\n",
2097 GCC_2s (c));
2098 GCC_check_connections ();
2099 return;
2100 }
2101
2102 oldstate = c->state;
2103 LOG (GNUNET_ERROR_TYPE_DEBUG, " via peer %s\n", GCP_2s (peer));
2104 if (get_next_hop (c) == peer)
2105 {
2106 LOG (GNUNET_ERROR_TYPE_DEBUG, " SYNACK\n");
2107 fwd = GNUNET_NO;
2108 if (CADET_CONNECTION_SENT == oldstate)
2109 connection_change_state (c, CADET_CONNECTION_ACK);
2110 }
2111 else if (get_prev_hop (c) == peer)
2112 {
2113 LOG (GNUNET_ERROR_TYPE_DEBUG, " FINAL ACK\n");
2114 fwd = GNUNET_YES;
2115 connection_change_state (c, CADET_CONNECTION_READY);
2116 }
2117 else
2118 {
2119 GNUNET_STATISTICS_update (stats, "# control on connection from wrong peer",
2120 1, GNUNET_NO);
2121 GNUNET_break_op (0);
2122 return;
2123 }
2124
2125 connection_reset_timeout (c, fwd);
2126
2127 GNUNET_assert (NULL != c->path);
2128 GCP_add_path_to_all (c->path, GNUNET_YES);
2129
2130 /* Message for us as creator? */
2131 if (GNUNET_YES == GCC_is_origin (c, GNUNET_YES))
2132 {
2133 if (GNUNET_NO != fwd)
2134 {
2135 GNUNET_break (0);
2136 return;
2137 }
2138 LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection (SYN)ACK for us!\n");
2139
2140 /* If just created, cancel the short timeout and start a long one */
2141 if (CADET_CONNECTION_SENT == oldstate)
2142 {
2143 c->create_retry = 1;
2144 connection_reset_timeout (c, GNUNET_YES);
2145 }
2146
2147 /* Change connection state, send ACK */
2148 connection_change_state (c, CADET_CONNECTION_READY);
2149 send_connection_ack (c, GNUNET_YES);
2150
2151 /* Change tunnel state, trigger KX */
2152 if (CADET_TUNNEL_WAITING == GCT_get_cstate (c->t))
2153 GCT_change_cstate (c->t, CADET_TUNNEL_READY);
2154 GCC_check_connections ();
2155 return;
2156 }
2157
2158 /* Message for us as destination? */
2159 if (GCC_is_terminal (c, GNUNET_YES))
2160 {
2161 if (GNUNET_YES != fwd)
2162 {
2163 GNUNET_break (0);
2164 return;
2165 }
2166 LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection ACK for us!\n");
2167
2168 /* If just created, cancel the short timeout and start a long one */
2169 if (CADET_CONNECTION_ACK == oldstate)
2170 connection_reset_timeout (c, GNUNET_NO);
2171
2172 /* Change tunnel state */
2173 if (CADET_TUNNEL_WAITING == GCT_get_cstate (c->t))
2174 GCT_change_cstate (c->t, CADET_TUNNEL_READY);
2175 GCC_check_connections ();
2176 }
2177 else
2178 {
2179 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
2180 (void) GCC_send_prebuilt_message (&msg->header, 0,
2181 zero,
2182 c,
2183 fwd,
2184 GNUNET_YES, NULL, NULL);
2185 }
2186 GCC_check_connections ();
2187}
2188
2189
2190/**
2191 * Handler for notifications of broken connections.
2192 *
2193 * @param peer Message sender (neighbor).
2194 * @param msg Message itself.
2195 */
2196void
2197GCC_handle_broken (struct CadetPeer *peer,
2198 const struct GNUNET_CADET_ConnectionBrokenMessage *msg)
2199{
2200 static struct CadetEncryptedMessageIdentifier zero;
2201 struct CadetConnection *c;
2202 struct CadetTunnel *t;
2203 int fwd;
2204
2205 GCC_check_connections ();
2206 log_message (&msg->header, peer, &msg->cid);
2207 LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n", GNUNET_i2s (&msg->peer1));
2208 LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n", GNUNET_i2s (&msg->peer2));
2209 c = connection_get (&msg->cid);
2210 if (NULL == c)
2211 {
2212 LOG (GNUNET_ERROR_TYPE_DEBUG, " duplicate CONNECTION_BROKEN\n");
2213 GNUNET_STATISTICS_update (stats, "# duplicate CONNECTION_BROKEN",
2214 1, GNUNET_NO);
2215 GCC_check_connections ();
2216 return;
2217 }
2218
2219 t = c->t;
2220
2221 fwd = is_fwd (c, peer);
2222 if (GNUNET_SYSERR == fwd)
2223 {
2224 GNUNET_break_op (0);
2225 GCC_check_connections ();
2226 return;
2227 }
2228 mark_destroyed (c);
2229 if (GCC_is_terminal (c, fwd))
2230 {
2231 struct CadetPeer *endpoint;
2232
2233 if (NULL == t)
2234 {
2235 /* A terminal connection should not have 't' set to NULL. */
2236 GNUNET_break (0);
2237 GCC_debug (c, GNUNET_ERROR_TYPE_ERROR);
2238 return;
2239 }
2240 endpoint = GCP_get_short (c->path->peers[c->path->length - 1], GNUNET_YES);
2241 if (2 < c->path->length)
2242 path_invalidate (c->path);
2243 GCP_notify_broken_link (endpoint, &msg->peer1, &msg->peer2);
2244
2245 connection_change_state (c, CADET_CONNECTION_BROKEN);
2246 GCT_remove_connection (t, c);
2247 c->t = NULL;
2248
2249 GCC_destroy (c);
2250 }
2251 else
2252 {
2253 (void) GCC_send_prebuilt_message (&msg->header, 0,
2254 zero, c, fwd,
2255 GNUNET_YES, NULL, NULL);
2256 connection_cancel_queues (c, !fwd);
2257 }
2258 GCC_check_connections ();
2259 return;
2260}
2261
2262
2263/**
2264 * Handler for notifications of destroyed connections.
2265 *
2266 * @param peer Message sender (neighbor).
2267 * @param msg Message itself.
2268 */
2269void
2270GCC_handle_destroy (struct CadetPeer *peer,
2271 const struct GNUNET_CADET_ConnectionDestroyMessage *msg)
2272{
2273 static struct CadetEncryptedMessageIdentifier zero;
2274 struct CadetConnection *c;
2275 int fwd;
2276
2277 GCC_check_connections ();
2278 log_message (&msg->header, peer, &msg->cid);
2279 c = connection_get (&msg->cid);
2280 if (NULL == c)
2281 {
2282 /* Probably already got the message from another path,
2283 * destroyed the tunnel and retransmitted to children.
2284 * Safe to ignore.
2285 */
2286 GNUNET_STATISTICS_update (stats,
2287 "# control on unknown connection",
2288 1, GNUNET_NO);
2289 LOG (GNUNET_ERROR_TYPE_DEBUG,
2290 " connection unknown destroyed: previously destroyed?\n");
2291 GCC_check_connections ();
2292 return;
2293 }
2294
2295 fwd = is_fwd (c, peer);
2296 if (GNUNET_SYSERR == fwd)
2297 {
2298 GNUNET_break_op (0);
2299 GCC_check_connections ();
2300 return;
2301 }
2302
2303 if (GNUNET_NO == GCC_is_terminal (c, fwd))
2304 {
2305 (void) GCC_send_prebuilt_message (&msg->header, 0,
2306 zero, c, fwd,
2307 GNUNET_YES, NULL, NULL);
2308 }
2309 else if (0 == c->pending_messages)
2310 {
2311 LOG (GNUNET_ERROR_TYPE_DEBUG, " directly destroying connection!\n");
2312 GCC_destroy (c);
2313 GCC_check_connections ();
2314 return;
2315 }
2316 mark_destroyed (c);
2317 if (NULL != c->t)
2318 {
2319 GCT_remove_connection (c->t, c);
2320 c->t = NULL;
2321 }
2322 GCC_check_connections ();
2323 return;
2324}
2325
2326
2327/**
2328 * Handler for cadet network traffic hop-by-hop acks.
2329 *
2330 * @param peer Message sender (neighbor).
2331 * @param msg Message itself.
2332 */
2333void
2334GCC_handle_ack (struct CadetPeer *peer,
2335 const struct GNUNET_CADET_ConnectionEncryptedAckMessage *msg)
2336{
2337 struct CadetConnection *c;
2338 struct CadetFlowControl *fc;
2339 struct CadetEncryptedMessageIdentifier ack;
2340 int fwd;
2341
2342 GCC_check_connections ();
2343 log_message (&msg->header, peer, &msg->cid);
2344 c = connection_get (&msg->cid);
2345 if (NULL == c)
2346 {
2347 GNUNET_STATISTICS_update (stats,
2348 "# ack on unknown connection",
2349 1,
2350 GNUNET_NO);
2351 send_broken_unknown (&msg->cid,
2352 &my_full_id,
2353 NULL,
2354 peer);
2355 GCC_check_connections ();
2356 return;
2357 }
2358
2359 /* Is this a forward or backward ACK? */
2360 if (get_next_hop (c) == peer)
2361 {
2362 fc = &c->fwd_fc;
2363 fwd = GNUNET_YES;
2364 }
2365 else if (get_prev_hop (c) == peer)
2366 {
2367 fc = &c->bck_fc;
2368 fwd = GNUNET_NO;
2369 }
2370 else
2371 {
2372 GNUNET_break_op (0);
2373 return;
2374 }
2375
2376 ack = msg->cemi_max;
2377 LOG (GNUNET_ERROR_TYPE_DEBUG, " %s ACK %u (was %u)\n",
2378 GC_f2s (fwd),
2379 ntohl (ack.pid),
2380 ntohl (fc->last_ack_recv.pid));
2381 if (GC_is_pid_bigger (ntohl (ack.pid),
2382 ntohl (fc->last_ack_recv.pid)))
2383 fc->last_ack_recv = ack;
2384
2385 /* Cancel polling if the ACK is big enough. */
2386 if ( (NULL != fc->poll_task) &
2387 GC_is_pid_bigger (ntohl (fc->last_ack_recv.pid),
2388 ntohl (fc->last_pid_sent.pid)))
2389 {
2390 LOG (GNUNET_ERROR_TYPE_DEBUG, " Cancel poll\n");
2391 GNUNET_SCHEDULER_cancel (fc->poll_task);
2392 fc->poll_task = NULL;
2393 fc->poll_time = GNUNET_TIME_UNIT_SECONDS;
2394 }
2395
2396 GCC_check_connections ();
2397}
2398
2399
2400/**
2401 * Handler for cadet network traffic hop-by-hop data counter polls.
2402 *
2403 * @param peer Message sender (neighbor).
2404 * @param msg Message itself.
2405 */
2406void
2407GCC_handle_poll (struct CadetPeer *peer,
2408 const struct GNUNET_CADET_ConnectionHopByHopPollMessage *msg)
2409{
2410 struct CadetConnection *c;
2411 struct CadetFlowControl *fc;
2412 struct CadetEncryptedMessageIdentifier pid;
2413 int fwd;
2414
2415 GCC_check_connections ();
2416 log_message (&msg->header, peer, &msg->cid);
2417 c = connection_get (&msg->cid);
2418 if (NULL == c)
2419 {
2420 GNUNET_STATISTICS_update (stats, "# poll on unknown connection", 1,
2421 GNUNET_NO);
2422 LOG (GNUNET_ERROR_TYPE_DEBUG,
2423 "POLL message on unknown connection %s!\n",
2424 GNUNET_sh2s (&msg->cid.connection_of_tunnel));
2425 send_broken_unknown (&msg->cid,
2426 &my_full_id,
2427 NULL,
2428 peer);
2429 GCC_check_connections ();
2430 return;
2431 }
2432
2433 /* Is this a forward or backward ACK?
2434 * Note: a poll should never be needed in a loopback case,
2435 * since there is no possiblility of packet loss there, so
2436 * this way of discerining FWD/BCK should not be a problem.
2437 */
2438 if (get_next_hop (c) == peer)
2439 {
2440 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD FC\n");
2441 fc = &c->fwd_fc;
2442 }
2443 else if (get_prev_hop (c) == peer)
2444 {
2445 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK FC\n");
2446 fc = &c->bck_fc;
2447 }
2448 else
2449 {
2450 GNUNET_break_op (0);
2451 return;
2452 }
2453
2454 pid = msg->cemi;
2455 LOG (GNUNET_ERROR_TYPE_DEBUG,
2456 " PID %u, OLD %u\n",
2457 ntohl (pid.pid),
2458 ntohl (fc->last_pid_recv.pid));
2459 fc->last_pid_recv = pid;
2460 fwd = fc == &c->bck_fc;
2461 GCC_send_ack (c, fwd, GNUNET_YES);
2462 GCC_check_connections ();
2463}
2464
2465
2466/**
2467 * Check the message against internal state and test if it goes FWD or BCK.
2468 *
2469 * Updates the PID, state and timeout values for the connection.
2470 *
2471 * @param message Message to check. It must belong to an existing connection.
2472 * @param cid Connection ID (even if @a c is NULL, the ID is still needed).
2473 * @param c Connection this message should belong. If NULL, check fails.
2474 * @param sender Neighbor that sent the message.
2475 *
2476 * @return #GNUNET_YES if the message goes FWD.
2477 * #GNUNET_NO if it goes BCK.
2478 * #GNUNET_SYSERR if there is an error (unauthorized sender, ...).
2479 */
2480static int
2481check_message (const struct GNUNET_MessageHeader *message,
2482 const struct GNUNET_CADET_ConnectionTunnelIdentifier* cid,
2483 struct CadetConnection *c,
2484 struct CadetPeer *sender,
2485 struct CadetEncryptedMessageIdentifier pid)
2486{
2487 struct CadetFlowControl *fc;
2488 struct CadetPeer *hop;
2489 int fwd;
2490 uint16_t type;
2491
2492 /* Check connection */
2493 if (NULL == c)
2494 {
2495 GNUNET_STATISTICS_update (stats,
2496 "# unknown connection",
2497 1, GNUNET_NO);
2498 LOG (GNUNET_ERROR_TYPE_DEBUG,
2499 "%s on unknown connection %s\n",
2500 GC_m2s (ntohs (message->type)),
2501 GNUNET_sh2s (&cid->connection_of_tunnel));
2502 GNUNET_break_op (0);
2503 send_broken_unknown (cid,
2504 &my_full_id,
2505 NULL,
2506 sender);
2507 return GNUNET_SYSERR;
2508 }
2509
2510 /* Check if origin is as expected */
2511 hop = get_prev_hop (c);
2512 if (sender == hop)
2513 {
2514 fwd = GNUNET_YES;
2515 }
2516 else
2517 {
2518 hop = get_next_hop (c);
2519 GNUNET_break (hop == c->next_peer);
2520 if (sender == hop)
2521 {
2522 fwd = GNUNET_NO;
2523 }
2524 else
2525 {
2526 /* Unexpected peer sending traffic on a connection. */
2527 GNUNET_break_op (0);
2528 return GNUNET_SYSERR;
2529 }
2530 }
2531
2532 /* Check PID for payload messages */
2533 type = ntohs (message->type);
2534 if (GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED == type)
2535 {
2536 fc = fwd ? &c->bck_fc : &c->fwd_fc;
2537 LOG (GNUNET_ERROR_TYPE_DEBUG, " PID %u (expected in interval [%u,%u])\n",
2538 ntohl (pid.pid),
2539 ntohl (fc->last_pid_recv.pid) + 1,
2540 ntohl (fc->last_ack_sent.pid));
2541 if (GC_is_pid_bigger (ntohl (pid.pid),
2542 ntohl (fc->last_ack_sent.pid)))
2543 {
2544 GNUNET_STATISTICS_update (stats,
2545 "# unsolicited message",
2546 1,
2547 GNUNET_NO);
2548 LOG (GNUNET_ERROR_TYPE_WARNING,
2549 "Received PID %u, (prev %u), ACK %u\n",
2550 pid, fc->last_pid_recv, fc->last_ack_sent);
2551 return GNUNET_SYSERR;
2552 }
2553 if (GC_is_pid_bigger (ntohl (pid.pid),
2554 ntohl (fc->last_pid_recv.pid)))
2555 {
2556 unsigned int delta;
2557
2558 delta = ntohl (pid.pid) - ntohl (fc->last_pid_recv.pid);
2559 fc->last_pid_recv = pid;
2560 fc->recv_bitmap <<= delta;
2561 fc->recv_bitmap |= 1;
2562 }
2563 else
2564 {
2565 GNUNET_STATISTICS_update (stats,
2566 "# out of order PID",
2567 1,
2568 GNUNET_NO);
2569 if (GNUNET_NO == is_ooo_ok (fc->last_pid_recv,
2570 pid,
2571 fc->recv_bitmap))
2572 {
2573 LOG (GNUNET_ERROR_TYPE_WARNING,
2574 "PID %u unexpected (%u+), dropping!\n",
2575 ntohl (pid.pid),
2576 ntohl (fc->last_pid_recv.pid) - 31);
2577 return GNUNET_SYSERR;
2578 }
2579 fc->recv_bitmap |= get_recv_bitmask (fc->last_pid_recv,
2580 pid);
2581 }
2582 }
2583
2584 /* Count as connection confirmation. */
2585 if ( (CADET_CONNECTION_SENT == c->state) ||
2586 (CADET_CONNECTION_ACK == c->state) )
2587 {
2588 connection_change_state (c, CADET_CONNECTION_READY);
2589 if (NULL != c->t)
2590 {
2591 if (CADET_TUNNEL_WAITING == GCT_get_cstate (c->t))
2592 GCT_change_cstate (c->t, CADET_TUNNEL_READY);
2593 }
2594 }
2595 connection_reset_timeout (c, fwd);
2596
2597 return fwd;
2598}
2599
2600
2601/**
2602 * Handler for key exchange traffic (Axolotl KX).
2603 *
2604 * @param peer Message sender (neighbor).
2605 * @param msg Message itself.
2606 */
2607void
2608GCC_handle_kx (struct CadetPeer *peer,
2609 const struct GNUNET_CADET_TunnelKeyExchangeMessage *msg)
2610{
2611 static struct CadetEncryptedMessageIdentifier zero;
2612 const struct GNUNET_CADET_ConnectionTunnelIdentifier* cid;
2613 struct CadetConnection *c;
2614 int fwd;
2615
2616 GCC_check_connections ();
2617 cid = &msg->cid;
2618 log_message (&msg->header, peer, cid);
2619
2620 c = connection_get (cid);
2621 fwd = check_message (&msg->header,
2622 cid,
2623 c,
2624 peer,
2625 zero);
2626
2627 /* If something went wrong, discard message. */
2628 if (GNUNET_SYSERR == fwd)
2629 {
2630 GNUNET_break_op (0);
2631 GCC_check_connections ();
2632 return;
2633 }
2634
2635 /* Is this message for us? */
2636 if (GCC_is_terminal (c, fwd))
2637 {
2638 LOG (GNUNET_ERROR_TYPE_DEBUG, " message for us!\n");
2639 GNUNET_STATISTICS_update (stats, "# received KX", 1, GNUNET_NO);
2640 if (NULL == c->t)
2641 {
2642 GNUNET_break (0);
2643 return;
2644 }
2645 GCT_handle_kx (c->t, msg);
2646 GCC_check_connections ();
2647 return;
2648 }
2649
2650 /* Message not for us: forward to next hop */
2651 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
2652 GNUNET_STATISTICS_update (stats, "# messages forwarded", 1, GNUNET_NO);
2653 (void) GCC_send_prebuilt_message (&msg->header, 0,
2654 zero, c, fwd,
2655 GNUNET_NO, NULL, NULL);
2656 GCC_check_connections ();
2657}
2658
2659
2660/**
2661 * Handler for encrypted cadet network traffic (channel mgmt, data).
2662 *
2663 * @param peer Message sender (neighbor).
2664 * @param msg Message itself.
2665 */
2666void
2667GCC_handle_encrypted (struct CadetPeer *peer,
2668 const struct GNUNET_CADET_TunnelEncryptedMessage *msg)
2669{
2670 static struct CadetEncryptedMessageIdentifier zero;
2671 const struct GNUNET_CADET_ConnectionTunnelIdentifier* cid;
2672 struct CadetConnection *c;
2673 struct CadetEncryptedMessageIdentifier pid;
2674 int fwd;
2675
2676 GCC_check_connections ();
2677 cid = &msg->cid;
2678 pid = msg->cemi;
2679 log_message (&msg->header, peer, cid);
2680
2681 c = connection_get (cid);
2682 fwd = check_message (&msg->header,
2683 cid,
2684 c,
2685 peer,
2686 pid);
2687
2688 /* If something went wrong, discard message. */
2689 if (GNUNET_SYSERR == fwd)
2690 {
2691 GCC_check_connections ();
2692 return;
2693 }
2694
2695 /* Is this message for us? */
2696 if (GCC_is_terminal (c, fwd))
2697 {
2698 GNUNET_STATISTICS_update (stats, "# received encrypted", 1, GNUNET_NO);
2699
2700 if (NULL == c->t)
2701 {
2702 GNUNET_break (GNUNET_NO != c->destroy);
2703 return;
2704 }
2705 GCT_handle_encrypted (c->t, msg);
2706 GCC_send_ack (c, fwd, GNUNET_NO);
2707 GCC_check_connections ();
2708 return;
2709 }
2710
2711 /* Message not for us: forward to next hop */
2712 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
2713 GNUNET_STATISTICS_update (stats, "# messages forwarded", 1, GNUNET_NO);
2714 (void) GCC_send_prebuilt_message (&msg->header, 0,
2715 zero, c, fwd,
2716 GNUNET_NO, NULL, NULL);
2717 GCC_check_connections ();
2718}
2719
2720
2721/**
2722 * Initialize the connections subsystem
2723 *
2724 * @param c Configuration handle.
2725 */
2726void
2727GCC_init (const struct GNUNET_CONFIGURATION_Handle *c)
2728{
2729 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
2730 if (GNUNET_OK !=
2731 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "MAX_MSGS_QUEUE",
2732 &max_msgs_queue))
2733 {
2734 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
2735 "CADET", "MAX_MSGS_QUEUE", "MISSING");
2736 GNUNET_SCHEDULER_shutdown ();
2737 return;
2738 }
2739
2740 if (GNUNET_OK !=
2741 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "MAX_CONNECTIONS",
2742 &max_connections))
2743 {
2744 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
2745 "CADET", "MAX_CONNECTIONS", "MISSING");
2746 GNUNET_SCHEDULER_shutdown ();
2747 return;
2748 }
2749
2750 if (GNUNET_OK !=
2751 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REFRESH_CONNECTION_TIME",
2752 &refresh_connection_time))
2753 {
2754 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
2755 "CADET", "REFRESH_CONNECTION_TIME", "MISSING");
2756 GNUNET_SCHEDULER_shutdown ();
2757 return;
2758 }
2759 create_connection_time = GNUNET_TIME_relative_min (GNUNET_TIME_UNIT_SECONDS,
2760 refresh_connection_time);
2761 connections = GNUNET_CONTAINER_multishortmap_create (1024,
2762 GNUNET_YES);
2763}
2764
2765
2766/**
2767 * Destroy each connection on shutdown.
2768 *
2769 * @param cls Closure (unused).
2770 * @param key Current key code (CID, unused).
2771 * @param value Value in the hash map (`struct CadetConnection`)
2772 *
2773 * @return #GNUNET_YES, because we should continue to iterate
2774 */
2775static int
2776shutdown_iterator (void *cls,
2777 const struct GNUNET_ShortHashCode *key,
2778 void *value)
2779{
2780 struct CadetConnection *c = value;
2781
2782 c->state = CADET_CONNECTION_DESTROYED;
2783 GCC_destroy (c);
2784 return GNUNET_YES;
2785}
2786
2787
2788/**
2789 * Shut down the connections subsystem.
2790 */
2791void
2792GCC_shutdown (void)
2793{
2794 LOG (GNUNET_ERROR_TYPE_DEBUG, "Shutting down connections\n");
2795 GCC_check_connections ();
2796 GNUNET_CONTAINER_multishortmap_iterate (connections,
2797 &shutdown_iterator,
2798 NULL);
2799 GNUNET_CONTAINER_multishortmap_destroy (connections);
2800 connections = NULL;
2801}
2802
2803
2804/**
2805 * Create a connection.
2806 *
2807 * @param cid Connection ID (either created locally or imposed remotely).
2808 * @param t Tunnel this connection belongs to (or NULL for transit connections);
2809 * @param path Path this connection has to use (copy is made).
2810 * @param own_pos Own position in the @c path path.
2811 *
2812 * @return Newly created connection.
2813 * NULL in case of error: own id not in path, wrong neighbors, ...
2814*/
2815struct CadetConnection *
2816GCC_new (const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid,
2817 struct CadetTunnel *t,
2818 struct CadetPeerPath *path,
2819 unsigned int own_pos)
2820{
2821 struct CadetConnection *c;
2822 struct CadetPeerPath *cpath;
2823
2824 GCC_check_connections ();
2825 cpath = path_duplicate (path);
2826 GNUNET_assert (NULL != cpath);
2827 c = GNUNET_new (struct CadetConnection);
2828 c->id = *cid;
2829 GNUNET_assert (GNUNET_OK ==
2830 GNUNET_CONTAINER_multishortmap_put (connections,
2831 &c->id.connection_of_tunnel,
2832 c,
2833 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
2834 fc_init (&c->fwd_fc);
2835 fc_init (&c->bck_fc);
2836 c->fwd_fc.c = c;
2837 c->bck_fc.c = c;
2838
2839 c->t = t;
2840 GNUNET_assert (own_pos <= cpath->length - 1);
2841 c->own_pos = own_pos;
2842 c->path = cpath;
2843 cpath->c = c;
2844 if (GNUNET_OK != register_neighbors (c))
2845 {
2846 if (0 == own_pos)
2847 {
2848 /* We were the origin of this request, this means we have invalid
2849 * info about the paths to reach the destination. We must invalidate
2850 * the *original* path to avoid trying it again in the next minute.
2851 */
2852 if (2 < path->length)
2853 path_invalidate (path);
2854 else
2855 {
2856 GNUNET_break (0);
2857 GCT_debug(t, GNUNET_ERROR_TYPE_WARNING);
2858 }
2859 c->t = NULL;
2860 }
2861 path_destroy (c->path);
2862 c->path = NULL;
2863 GCC_destroy (c);
2864 return NULL;
2865 }
2866 LOG (GNUNET_ERROR_TYPE_INFO, "New connection %s\n", GCC_2s (c));
2867 GCC_check_connections ();
2868 return c;
2869}
2870
2871
2872/**
2873 * Connection is no longer needed: destroy it.
2874 *
2875 * Cancels all pending traffic (including possible DESTROY messages), all
2876 * maintenance tasks and removes the connection from neighbor peers and tunnel.
2877 *
2878 * @param c Connection to destroy.
2879 */
2880void
2881GCC_destroy (struct CadetConnection *c)
2882{
2883 GCC_check_connections ();
2884 if (NULL == c)
2885 {
2886 GNUNET_break (0);
2887 return;
2888 }
2889
2890 if (2 == c->destroy) /* cancel queues -> GCP_queue_cancel -> q_destroy -> */
2891 return; /* -> message_sent -> GCC_destroy. Don't loop. */
2892 c->destroy = 2;
2893
2894 LOG (GNUNET_ERROR_TYPE_DEBUG,
2895 "destroying connection %s\n",
2896 GCC_2s (c));
2897 LOG (GNUNET_ERROR_TYPE_DEBUG,
2898 " fc's f: %p, b: %p\n",
2899 &c->fwd_fc, &c->bck_fc);
2900 LOG (GNUNET_ERROR_TYPE_DEBUG,
2901 " fc tasks f: %u, b: %u\n",
2902 c->fwd_fc.poll_task,
2903 c->bck_fc.poll_task);
2904
2905 /* Cancel all traffic */
2906 if (NULL != c->path)
2907 {
2908 connection_cancel_queues (c, GNUNET_YES);
2909 connection_cancel_queues (c, GNUNET_NO);
2910 if (NULL != c->maintenance_q)
2911 {
2912 GCP_send_cancel (c->maintenance_q);
2913 c->maintenance_q = NULL;
2914 }
2915 }
2916 unregister_neighbors (c);
2917 path_destroy (c->path);
2918 c->path = NULL;
2919
2920 /* Delete from tunnel */
2921 if (NULL != c->t)
2922 GCT_remove_connection (c->t, c);
2923
2924 if (NULL != c->check_duplicates_task)
2925 GNUNET_SCHEDULER_cancel (c->check_duplicates_task);
2926 if (NULL != c->fwd_maintenance_task)
2927 GNUNET_SCHEDULER_cancel (c->fwd_maintenance_task);
2928 if (NULL != c->bck_maintenance_task)
2929 GNUNET_SCHEDULER_cancel (c->bck_maintenance_task);
2930
2931 if (GNUNET_NO == c->was_removed)
2932 {
2933 GNUNET_break (GNUNET_YES ==
2934 GNUNET_CONTAINER_multishortmap_remove (connections,
2935 &c->id.connection_of_tunnel,
2936 c));
2937 }
2938 GNUNET_STATISTICS_update (stats,
2939 "# connections",
2940 -1,
2941 GNUNET_NO);
2942 GNUNET_free (c);
2943 GCC_check_connections ();
2944}
2945
2946
2947/**
2948 * Get the connection ID.
2949 *
2950 * @param c Connection to get the ID from.
2951 *
2952 * @return ID of the connection.
2953 */
2954const struct GNUNET_CADET_ConnectionTunnelIdentifier *
2955GCC_get_id (const struct CadetConnection *c)
2956{
2957 return &c->id;
2958}
2959
2960
2961/**
2962 * Get the connection path.
2963 *
2964 * @param c Connection to get the path from.
2965 *
2966 * @return path used by the connection.
2967 */
2968const struct CadetPeerPath *
2969GCC_get_path (const struct CadetConnection *c)
2970{
2971 if (GNUNET_NO == c->destroy)
2972 return c->path;
2973 return NULL;
2974}
2975
2976
2977/**
2978 * Get the connection state.
2979 *
2980 * @param c Connection to get the state from.
2981 *
2982 * @return state of the connection.
2983 */
2984enum CadetConnectionState
2985GCC_get_state (const struct CadetConnection *c)
2986{
2987 return c->state;
2988}
2989
2990/**
2991 * Get the connection tunnel.
2992 *
2993 * @param c Connection to get the tunnel from.
2994 *
2995 * @return tunnel of the connection.
2996 */
2997struct CadetTunnel *
2998GCC_get_tunnel (const struct CadetConnection *c)
2999{
3000 return c->t;
3001}
3002
3003
3004/**
3005 * Get free buffer space in a connection.
3006 *
3007 * @param c Connection.
3008 * @param fwd Is query about FWD traffic?
3009 *
3010 * @return Free buffer space [0 - max_msgs_queue/max_connections]
3011 */
3012unsigned int
3013GCC_get_buffer (struct CadetConnection *c, int fwd)
3014{
3015 struct CadetFlowControl *fc;
3016
3017 fc = fwd ? &c->fwd_fc : &c->bck_fc;
3018
3019 LOG (GNUNET_ERROR_TYPE_DEBUG, " Get %s buffer on %s: %u - %u\n",
3020 GC_f2s (fwd), GCC_2s (c), fc->queue_max, fc->queue_n);
3021 GCC_debug (c, GNUNET_ERROR_TYPE_DEBUG);
3022
3023 return (fc->queue_max - fc->queue_n);
3024}
3025
3026
3027/**
3028 * Get how many messages have we allowed to send to us from a direction.
3029 *
3030 * @param c Connection.
3031 * @param fwd Are we asking about traffic from FWD (BCK messages)?
3032 *
3033 * @return last_ack_sent - last_pid_recv
3034 */
3035unsigned int
3036GCC_get_allowed (struct CadetConnection *c, int fwd)
3037{
3038 struct CadetFlowControl *fc;
3039
3040 fc = fwd ? &c->fwd_fc : &c->bck_fc;
3041 if ( (CADET_CONNECTION_READY != c->state) ||
3042 GC_is_pid_bigger (ntohl (fc->last_pid_recv.pid),
3043 ntohl (fc->last_ack_sent.pid)) )
3044 {
3045 return 0;
3046 }
3047 return (ntohl (fc->last_ack_sent.pid) - ntohl (fc->last_pid_recv.pid));
3048}
3049
3050
3051/**
3052 * Get messages queued in a connection.
3053 *
3054 * @param c Connection.
3055 * @param fwd Is query about FWD traffic?
3056 *
3057 * @return Number of messages queued.
3058 */
3059unsigned int
3060GCC_get_qn (struct CadetConnection *c, int fwd)
3061{
3062 struct CadetFlowControl *fc;
3063
3064 fc = fwd ? &c->fwd_fc : &c->bck_fc;
3065
3066 return fc->queue_n;
3067}
3068
3069
3070/**
3071 * Get next PID to use.
3072 *
3073 * @param c Connection.
3074 * @param fwd Is query about FWD traffic?
3075 * @return Next PID to use.
3076 */
3077struct CadetEncryptedMessageIdentifier
3078GCC_get_pid (struct CadetConnection *c, int fwd)
3079{
3080 struct CadetFlowControl *fc;
3081 struct CadetEncryptedMessageIdentifier pid;
3082
3083 fc = fwd ? &c->fwd_fc : &c->bck_fc;
3084 pid = fc->next_pid;
3085 fc->next_pid.pid = htonl (1 + ntohl (pid.pid));
3086 return pid;
3087}
3088
3089
3090/**
3091 * Allow the connection to advertise a buffer of the given size.
3092 *
3093 * The connection will send an @c fwd ACK message (so: in direction !fwd)
3094 * allowing up to last_pid_recv + buffer.
3095 *
3096 * @param c Connection.
3097 * @param buffer How many more messages the connection can accept.
3098 * @param fwd Is this about FWD traffic? (The ack will go dest->root).
3099 */
3100void
3101GCC_allow (struct CadetConnection *c, unsigned int buffer, int fwd)
3102{
3103 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowing %s %u messages %s\n",
3104 GCC_2s (c), buffer, GC_f2s (fwd));
3105 send_ack (c, buffer, fwd, GNUNET_NO);
3106}
3107
3108
3109/**
3110 * Notify other peers on a connection of a broken link. Mark connections
3111 * to destroy after all traffic has been sent.
3112 *
3113 * @param c Connection on which there has been a disconnection.
3114 * @param peer Peer that disconnected.
3115 */
3116void
3117GCC_neighbor_disconnected (struct CadetConnection *c, struct CadetPeer *peer)
3118{
3119 struct CadetFlowControl *fc;
3120 char peer_name[16];
3121 int fwd;
3122
3123 GCC_check_connections ();
3124 strncpy (peer_name, GCP_2s (peer), 16);
3125 peer_name[15] = '\0';
3126 LOG (GNUNET_ERROR_TYPE_DEBUG,
3127 "shutting down %s, %s disconnected\n",
3128 GCC_2s (c), peer_name);
3129
3130 invalidate_paths (c, peer);
3131
3132 fwd = is_fwd (c, peer);
3133 if (GNUNET_SYSERR == fwd)
3134 {
3135 GNUNET_break (0);
3136 return;
3137 }
3138 if ( (GNUNET_YES == GCC_is_terminal (c, fwd)) ||
3139 (GNUNET_NO != c->destroy) )
3140 {
3141 /* Local shutdown, or other peer already down (hence 'c->destroy');
3142 so there is no one to notify about this, just clean up. */
3143 GCC_destroy (c);
3144 GCC_check_connections ();
3145 return;
3146 }
3147 /* Mark FlowControl towards the peer as unavaliable. */
3148 fc = fwd ? &c->bck_fc : &c->fwd_fc;
3149 fc->queue_max = 0;
3150
3151 send_broken (c, &my_full_id, GCP_get_id (peer), fwd);
3152
3153 /* Connection will have at least one pending message
3154 * (the one we just scheduled), so delay destruction
3155 * and remove from map so we don't use accidentally. */
3156 mark_destroyed (c);
3157 GNUNET_assert (GNUNET_NO == c->was_removed);
3158 c->was_removed = GNUNET_YES;
3159 GNUNET_break (GNUNET_YES ==
3160 GNUNET_CONTAINER_multishortmap_remove (connections,
3161 &c->id.connection_of_tunnel,
3162 c));
3163 /* Cancel queue in the direction that just died. */
3164 connection_cancel_queues (c, ! fwd);
3165 GCC_stop_poll (c, ! fwd);
3166 unregister_neighbors (c);
3167 GCC_check_connections ();
3168}
3169
3170
3171/**
3172 * Is this peer the first one on the connection?
3173 *
3174 * @param c Connection.
3175 * @param fwd Is this about fwd traffic?
3176 *
3177 * @return #GNUNET_YES if origin, #GNUNET_NO if relay/terminal.
3178 */
3179int
3180GCC_is_origin (struct CadetConnection *c, int fwd)
3181{
3182 if (!fwd && c->path->length - 1 == c->own_pos )
3183 return GNUNET_YES;
3184 if (fwd && 0 == c->own_pos)
3185 return GNUNET_YES;
3186 return GNUNET_NO;
3187}
3188
3189
3190/**
3191 * Is this peer the last one on the connection?
3192 *
3193 * @param c Connection.
3194 * @param fwd Is this about fwd traffic?
3195 * Note that the ROOT is the terminal for BCK traffic!
3196 *
3197 * @return #GNUNET_YES if terminal, #GNUNET_NO if relay/origin.
3198 */
3199int
3200GCC_is_terminal (struct CadetConnection *c, int fwd)
3201{
3202 return GCC_is_origin (c, ! fwd);
3203}
3204
3205
3206/**
3207 * See if we are allowed to send by the next hop in the given direction.
3208 *
3209 * @param c Connection.
3210 * @param fwd Is this about fwd traffic?
3211 *
3212 * @return #GNUNET_YES in case it's OK to send.
3213 */
3214int
3215GCC_is_sendable (struct CadetConnection *c, int fwd)
3216{
3217 struct CadetFlowControl *fc;
3218
3219 LOG (GNUNET_ERROR_TYPE_DEBUG,
3220 " checking sendability of %s traffic on %s\n",
3221 GC_f2s (fwd), GCC_2s (c));
3222 if (NULL == c)
3223 {
3224 GNUNET_break (0);
3225 return GNUNET_YES;
3226 }
3227 fc = fwd ? &c->fwd_fc : &c->bck_fc;
3228 LOG (GNUNET_ERROR_TYPE_DEBUG,
3229 " last ack recv: %u, last pid sent: %u\n",
3230 ntohl (fc->last_ack_recv.pid),
3231 ntohl (fc->last_pid_sent.pid));
3232 if (GC_is_pid_bigger (ntohl (fc->last_ack_recv.pid),
3233 ntohl (fc->last_pid_sent.pid)))
3234 {
3235 LOG (GNUNET_ERROR_TYPE_DEBUG, " sendable\n");
3236 return GNUNET_YES;
3237 }
3238 LOG (GNUNET_ERROR_TYPE_DEBUG, " not sendable\n");
3239 return GNUNET_NO;
3240}
3241
3242
3243/**
3244 * Check if this connection is a direct one (never trim a direct connection).
3245 *
3246 * @param c Connection.
3247 *
3248 * @return #GNUNET_YES in case it's a direct connection, #GNUNET_NO otherwise.
3249 */
3250int
3251GCC_is_direct (struct CadetConnection *c)
3252{
3253 return (c->path->length == 2) ? GNUNET_YES : GNUNET_NO;
3254}
3255
3256
3257/**
3258 * Sends a completely built message on a connection, properly registering
3259 * all used resources.
3260 *
3261 * @param message Message to send.
3262 * @param payload_type Type of payload, in case the message is encrypted.
3263 * 0 for restransmissions (when type is no longer known)
3264 * UINT16_MAX when not applicable.
3265 * @param payload_id ID of the payload (PID, ACK, ...).
3266 * @param c Connection on which this message is transmitted.
3267 * @param fwd Is this a fwd message?
3268 * @param force Force the connection to accept the message (buffer overfill).
3269 * @param cont Continuation called once message is sent. Can be NULL.
3270 * @param cont_cls Closure for @c cont.
3271 *
3272 * @return Handle to cancel the message before it's sent.
3273 * NULL on error.
3274 * Invalid on @c cont call.
3275 */
3276struct CadetConnectionQueue *
3277GCC_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
3278 uint16_t payload_type,
3279 struct CadetEncryptedMessageIdentifier payload_id,
3280 struct CadetConnection *c, int fwd, int force,
3281 GCC_sent cont, void *cont_cls)
3282{
3283 struct CadetFlowControl *fc;
3284 struct CadetConnectionQueue *q;
3285 uint16_t size;
3286 uint16_t type;
3287
3288 size = ntohs (message->size);
3289 type = ntohs (message->type);
3290
3291 GCC_check_connections ();
3292 fc = fwd ? &c->fwd_fc : &c->bck_fc;
3293 if (0 == fc->queue_max)
3294 {
3295 GNUNET_break (0);
3296 return NULL;
3297 }
3298
3299 LOG (GNUNET_ERROR_TYPE_INFO,
3300 "--> %s (%s %4u) on conn %s (%p) %s [%5u]\n",
3301 GC_m2s (type), GC_m2s (payload_type), payload_id, GCC_2s (c), c,
3302 GC_f2s(fwd), size);
3303 switch (type)
3304 {
3305 case GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED:
3306 LOG (GNUNET_ERROR_TYPE_DEBUG, " Q_N+ %p %u, PIDsnt: %u, ACKrcv: %u\n",
3307 fc,
3308 fc->queue_n,
3309 ntohl (fc->last_pid_sent.pid),
3310 ntohl (fc->last_ack_recv.pid));
3311 if (GNUNET_NO == force)
3312 {
3313 fc->queue_n++;
3314 }
3315 break;
3316
3317 case GNUNET_MESSAGE_TYPE_CADET_TUNNEL_KX:
3318 /* nothing to do here */
3319 break;
3320
3321 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE:
3322 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE_ACK:
3323 /* Should've only be used for restransmissions. */
3324 GNUNET_break (0 == payload_type);
3325 break;
3326
3327 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_HOP_BY_HOP_ENCRYPTED_ACK:
3328 case GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED_POLL:
3329 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY:
3330 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN:
3331 GNUNET_assert (GNUNET_YES == force);
3332 break;
3333
3334 default:
3335 GNUNET_break (0);
3336 return NULL;
3337 }
3338
3339 if (fc->queue_n > fc->queue_max && GNUNET_NO == force)
3340 {
3341 GNUNET_STATISTICS_update (stats, "# messages dropped (buffer full)",
3342 1, GNUNET_NO);
3343 GNUNET_break (0);
3344 LOG (GNUNET_ERROR_TYPE_DEBUG, "queue full: %u/%u\n",
3345 fc->queue_n, fc->queue_max);
3346 if (GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED == type)
3347 {
3348 fc->queue_n--;
3349 }
3350 return NULL; /* Drop this message */
3351 }
3352
3353 LOG (GNUNET_ERROR_TYPE_DEBUG, " C_P+ %s %u\n",
3354 GCC_2s (c), c->pending_messages);
3355 c->pending_messages++;
3356
3357 q = GNUNET_new (struct CadetConnectionQueue);
3358 q->cont = cont;
3359 q->cont_cls = cont_cls;
3360 q->forced = force;
3361 GNUNET_CONTAINER_DLL_insert (fc->q_head, fc->q_tail, q);
3362 q->peer_q = GCP_send (get_hop (c, fwd),
3363 message,
3364 payload_type,
3365 payload_id,
3366 c,
3367 fwd,
3368 &conn_message_sent, q);
3369 if (NULL == q->peer_q)
3370 {
3371 LOG (GNUNET_ERROR_TYPE_DEBUG, "dropping msg on %s, NULL q\n", GCC_2s (c));
3372 GNUNET_CONTAINER_DLL_remove (fc->q_head, fc->q_tail, q);
3373 GNUNET_free (q);
3374 GCC_check_connections ();
3375 return NULL;
3376 }
3377 GCC_check_connections ();
3378 return q;
3379}
3380
3381
3382/**
3383 * Cancel a previously sent message while it's in the queue.
3384 *
3385 * ONLY can be called before the continuation given to the send function
3386 * is called. Once the continuation is called, the message is no longer in the
3387 * queue.
3388 *
3389 * @param q Handle to the queue.
3390 */
3391void
3392GCC_cancel (struct CadetConnectionQueue *q)
3393{
3394 LOG (GNUNET_ERROR_TYPE_DEBUG, "! GCC cancel message\n");
3395
3396 /* send_cancel calls message_sent, which calls q->cont and frees q */
3397 GCP_send_cancel (q->peer_q);
3398 GCC_check_connections ();
3399}
3400
3401
3402/**
3403 * Sends a CREATE CONNECTION message for a path to a peer.
3404 * Changes the connection and tunnel states if necessary.
3405 *
3406 * @param c Connection to create.
3407 */
3408void
3409GCC_send_create (struct CadetConnection *c)
3410{
3411 static struct CadetEncryptedMessageIdentifier zero;
3412 enum CadetTunnelCState state;
3413 size_t size;
3414
3415 GCC_check_connections ();
3416 size = sizeof (struct GNUNET_CADET_ConnectionCreateMessage);
3417 size += c->path->length * sizeof (struct GNUNET_PeerIdentity);
3418 {
3419 /* Allocate message on the stack */
3420 unsigned char cbuf[size];
3421 struct GNUNET_CADET_ConnectionCreateMessage *msg;
3422 struct GNUNET_PeerIdentity *peers;
3423
3424
3425 msg = (struct GNUNET_CADET_ConnectionCreateMessage *) cbuf;
3426 msg->header.size = htons (size);
3427 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE);
3428 msg->options = htonl (0);
3429 msg->cid = *GCC_get_id (c);
3430 peers = (struct GNUNET_PeerIdentity *) &msg[1];
3431 for (int i = 0; i < c->path->length; i++)
3432 {
3433 GNUNET_PEER_resolve (c->path->peers[i], peers++);
3434 }
3435 GNUNET_assert (NULL == c->maintenance_q);
3436 c->maintenance_q = GCP_send (get_next_hop (c),
3437 &msg->header,
3438 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE,
3439 zero,
3440 c, GNUNET_YES,
3441 &conn_message_sent, NULL);
3442 }
3443
3444 LOG (GNUNET_ERROR_TYPE_INFO, "==> %s %19s on conn %s (%p) FWD [%5u]\n",
3445 GC_m2s (GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE), "",
3446 GCC_2s (c), c, size);
3447 LOG (GNUNET_ERROR_TYPE_DEBUG, " C_P+ %p %u (create)\n",
3448 c, c->pending_messages);
3449 c->pending_messages++;
3450
3451 state = GCT_get_cstate (c->t);
3452 if (CADET_TUNNEL_SEARCHING == state || CADET_TUNNEL_NEW == state)
3453 GCT_change_cstate (c->t, CADET_TUNNEL_WAITING);
3454 if (CADET_CONNECTION_NEW == c->state)
3455 connection_change_state (c, CADET_CONNECTION_SENT);
3456 GCC_check_connections ();
3457}
3458
3459
3460/**
3461 * Send an ACK on the appropriate connection/channel, depending on
3462 * the direction and the position of the peer.
3463 *
3464 * @param c Which connection to send the hop-by-hop ACK.
3465 * @param fwd Is this a fwd ACK? (will go dest->root).
3466 * @param force Send the ACK even if suboptimal (e.g. requested by POLL).
3467 */
3468void
3469GCC_send_ack (struct CadetConnection *c, int fwd, int force)
3470{
3471 unsigned int buffer;
3472
3473 GCC_check_connections ();
3474 LOG (GNUNET_ERROR_TYPE_DEBUG, "GCC send %s ACK on %s\n",
3475 GC_f2s (fwd), GCC_2s (c));
3476
3477 if (NULL == c)
3478 {
3479 GNUNET_break (0);
3480 return;
3481 }
3482
3483 if (GNUNET_NO != c->destroy)
3484 {
3485 LOG (GNUNET_ERROR_TYPE_DEBUG, " being destroyed, why bother...\n");
3486 GCC_check_connections ();
3487 return;
3488 }
3489
3490 /* Get available buffer space */
3491 if (GCC_is_terminal (c, fwd))
3492 {
3493 LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from all channels\n");
3494 buffer = GCT_get_channels_buffer (c->t);
3495 }
3496 else
3497 {
3498 LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from one connection\n");
3499 buffer = GCC_get_buffer (c, fwd);
3500 }
3501 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer available: %u\n", buffer);
3502 if (0 == buffer && GNUNET_NO == force)
3503 {
3504 GCC_check_connections ();
3505 return;
3506 }
3507
3508 /* Send available buffer space */
3509 if (GNUNET_YES == GCC_is_origin (c, fwd))
3510 {
3511 GNUNET_assert (NULL != c->t);
3512 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channels...\n");
3513 GCT_unchoke_channels (c->t);
3514 }
3515 else
3516 {
3517 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on connection\n");
3518 send_ack (c, buffer, fwd, force);
3519 }
3520 GCC_check_connections ();
3521}
3522
3523
3524/**
3525 * Send a message to all peers in this connection that the connection
3526 * is no longer valid.
3527 *
3528 * If some peer should not receive the message, it should be zero'ed out
3529 * before calling this function.
3530 *
3531 * @param c The connection whose peers to notify.
3532 */
3533void
3534GCC_send_destroy (struct CadetConnection *c)
3535{
3536 static struct CadetEncryptedMessageIdentifier zero;
3537 struct GNUNET_CADET_ConnectionDestroyMessage msg;
3538
3539 if (GNUNET_YES == c->destroy)
3540 return;
3541 GCC_check_connections ();
3542 msg.header.size = htons (sizeof (msg));
3543 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY);
3544 msg.cid = c->id;
3545 msg.reserved = htonl (0);
3546 LOG (GNUNET_ERROR_TYPE_DEBUG,
3547 " sending connection destroy for connection %s\n",
3548 GCC_2s (c));
3549
3550 if (GNUNET_NO == GCC_is_terminal (c, GNUNET_YES))
3551 (void) GCC_send_prebuilt_message (&msg.header,
3552 UINT16_MAX,
3553 zero,
3554 c,
3555 GNUNET_YES, GNUNET_YES, NULL, NULL);
3556 if (GNUNET_NO == GCC_is_terminal (c, GNUNET_NO))
3557 (void) GCC_send_prebuilt_message (&msg.header,
3558 UINT16_MAX,
3559 zero,
3560 c,
3561 GNUNET_NO, GNUNET_YES, NULL, NULL);
3562 mark_destroyed (c);
3563 GCC_check_connections ();
3564}
3565
3566
3567/**
3568 * @brief Start a polling timer for the connection.
3569 *
3570 * When a neighbor does not accept more traffic on the connection it could be
3571 * caused by a simple congestion or by a lost ACK. Polling enables to check
3572 * for the lastest ACK status for a connection.
3573 *
3574 * @param c Connection.
3575 * @param fwd Should we poll in the FWD direction?
3576 */
3577void
3578GCC_start_poll (struct CadetConnection *c, int fwd)
3579{
3580 struct CadetFlowControl *fc;
3581
3582 fc = fwd ? &c->fwd_fc : &c->bck_fc;
3583 LOG (GNUNET_ERROR_TYPE_DEBUG, "POLL %s requested\n",
3584 GC_f2s (fwd));
3585 if (NULL != fc->poll_task || NULL != fc->poll_msg)
3586 {
3587 LOG (GNUNET_ERROR_TYPE_DEBUG, " POLL already in progress (t: %p, m: %p)\n",
3588 fc->poll_task, fc->poll_msg);
3589 return;
3590 }
3591 if (0 == fc->queue_max)
3592 {
3593 /* Should not be needed, traffic should've been cancelled. */
3594 GNUNET_break (0);
3595 LOG (GNUNET_ERROR_TYPE_DEBUG, " POLL not possible, peer disconnected\n");
3596 return;
3597 }
3598 LOG (GNUNET_ERROR_TYPE_DEBUG, "POLL started on request\n");
3599 fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time, &send_poll, fc);
3600}
3601
3602
3603/**
3604 * @brief Stop polling a connection for ACKs.
3605 *
3606 * Once we have enough ACKs for future traffic, polls are no longer necessary.
3607 *
3608 * @param c Connection.
3609 * @param fwd Should we stop the poll in the FWD direction?
3610 */
3611void
3612GCC_stop_poll (struct CadetConnection *c, int fwd)
3613{
3614 struct CadetFlowControl *fc;
3615
3616 fc = fwd ? &c->fwd_fc : &c->bck_fc;
3617 if (NULL != fc->poll_task)
3618 {
3619 GNUNET_SCHEDULER_cancel (fc->poll_task);
3620 fc->poll_task = NULL;
3621 }
3622 if (NULL != fc->poll_msg)
3623 {
3624 GCC_cancel (fc->poll_msg);
3625 fc->poll_msg = NULL;
3626 }
3627}
3628
3629
3630/**
3631 * Get a (static) string for a connection.
3632 *
3633 * @param c Connection.
3634 */
3635const char *
3636GCC_2s (const struct CadetConnection *c)
3637{
3638 if (NULL == c)
3639 return "NULL";
3640
3641 if (NULL != c->t)
3642 {
3643 static char buf[128];
3644
3645 SPRINTF (buf, "%s (->%s)",
3646 GNUNET_sh2s (&GCC_get_id (c)->connection_of_tunnel),
3647 GCT_2s (c->t));
3648 return buf;
3649 }
3650 return GNUNET_sh2s (&c->id.connection_of_tunnel);
3651}
3652
3653
3654/**
3655 * Log all possible info about the connection state.
3656 *
3657 * @param c Connection to debug.
3658 * @param level Debug level to use.
3659 */
3660void
3661GCC_debug (const struct CadetConnection *c, enum GNUNET_ErrorType level)
3662{
3663 int do_log;
3664 char *s;
3665
3666 do_log = GNUNET_get_log_call_status (level & (~GNUNET_ERROR_TYPE_BULK),
3667 "cadet-con",
3668 __FILE__, __FUNCTION__, __LINE__);
3669 if (0 == do_log)
3670 return;
3671
3672 if (NULL == c)
3673 {
3674 LOG2 (level, "CCC DEBUG NULL CONNECTION\n");
3675 return;
3676 }
3677
3678 LOG2 (level, "CCC DEBUG CONNECTION %s\n", GCC_2s (c));
3679 s = path_2s (c->path);
3680 LOG2 (level, "CCC path %s, own pos: %u\n", s, c->own_pos);
3681 GNUNET_free (s);
3682 LOG2 (level, "CCC state: %s, destroy: %u\n",
3683 GCC_state2s (c->state), c->destroy);
3684 LOG2 (level, "CCC pending messages: %u\n", c->pending_messages);
3685 if (NULL != c->perf)
3686 LOG2 (level, "CCC us/byte: %f\n", c->perf->avg);
3687
3688 LOG2 (level, "CCC FWD flow control:\n");
3689 LOG2 (level, "CCC queue: %u/%u\n", c->fwd_fc.queue_n, c->fwd_fc.queue_max);
3690 LOG2 (level, "CCC last PID sent: %5u, recv: %5u\n",
3691 ntohl (c->fwd_fc.last_pid_sent.pid),
3692 ntohl (c->fwd_fc.last_pid_recv.pid));
3693 LOG2 (level, "CCC last ACK sent: %5u, recv: %5u\n",
3694 ntohl (c->fwd_fc.last_ack_sent.pid),
3695 ntohl (c->fwd_fc.last_ack_recv.pid));
3696 LOG2 (level, "CCC recv PID bitmap: %X\n", c->fwd_fc.recv_bitmap);
3697 LOG2 (level, "CCC poll: task %d, msg %p, msg_ack %p)\n",
3698 c->fwd_fc.poll_task, c->fwd_fc.poll_msg, c->fwd_fc.ack_msg);
3699
3700 LOG2 (level, "CCC BCK flow control:\n");
3701 LOG2 (level, "CCC queue: %u/%u\n", c->bck_fc.queue_n, c->bck_fc.queue_max);
3702 LOG2 (level, "CCC last PID sent: %5u, recv: %5u\n",
3703 ntohl (c->bck_fc.last_pid_sent.pid),
3704 ntohl (c->bck_fc.last_pid_recv.pid));
3705 LOG2 (level, "CCC last ACK sent: %5u, recv: %5u\n",
3706 ntohl (c->bck_fc.last_ack_sent.pid),
3707 ntohl (c->bck_fc.last_ack_recv.pid));
3708 LOG2 (level, "CCC recv PID bitmap: %X\n", c->bck_fc.recv_bitmap);
3709 LOG2 (level, "CCC poll: task %d, msg %p, msg_ack %p)\n",
3710 c->bck_fc.poll_task, c->bck_fc.poll_msg, c->bck_fc.ack_msg);
3711
3712 LOG2 (level, "CCC DEBUG CONNECTION END\n");
3713}
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-01 13:41:08 +0000