aboutsummaryrefslogtreecommitdiff
path: root/src/cadet/gnunet-service-cadet_connection.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/cadet/gnunet-service-cadet_connection.c')
-rw-r--r--src/cadet/gnunet-service-cadet_connection.c3176
1 files changed, 3176 insertions, 0 deletions
diff --git a/src/cadet/gnunet-service-cadet_connection.c b/src/cadet/gnunet-service-cadet_connection.c
new file mode 100644
index 000000000..9c07e006b
--- /dev/null
+++ b/src/cadet/gnunet-service-cadet_connection.c
@@ -0,0 +1,3176 @@
1/*
2 This file is part of GNUnet.
3 (C) 2001-2013 Christian Grothoff (and other contributing authors)
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., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
19*/
20
21/**
22 * @file cadet/gnunet-service-cadet_connection.c
23 * @brief GNUnet CADET service connection handling
24 * @author Bartlomiej Polot
25 */
26
27#include "platform.h"
28#include "gnunet_util_lib.h"
29
30#include "gnunet_statistics_service.h"
31
32#include "cadet_path.h"
33#include "cadet_protocol.h"
34#include "cadet.h"
35#include "gnunet-service-cadet_connection.h"
36#include "gnunet-service-cadet_peer.h"
37#include "gnunet-service-cadet_tunnel.h"
38
39
40#define LOG(level, ...) GNUNET_log_from (level,"cadet-con",__VA_ARGS__)
41
42#define CADET_MAX_POLL_TIME GNUNET_TIME_relative_multiply (\
43 GNUNET_TIME_UNIT_MINUTES,\
44 10)
45#define AVG_MSGS 32
46
47
48/******************************************************************************/
49/******************************** STRUCTS **********************************/
50/******************************************************************************/
51
52/**
53 * Struct to encapsulate all the Flow Control information to a peer to which
54 * we are directly connected (on a core level).
55 */
56struct CadetFlowControl
57{
58 /**
59 * Connection this controls.
60 */
61 struct CadetConnection *c;
62
63 /**
64 * How many messages are in the queue on this connection.
65 */
66 unsigned int queue_n;
67
68 /**
69 * How many messages do we accept in the queue.
70 */
71 unsigned int queue_max;
72
73 /**
74 * ID of the last packet sent towards the peer.
75 */
76 uint32_t last_pid_sent;
77
78 /**
79 * ID of the last packet received from the peer.
80 */
81 uint32_t last_pid_recv;
82
83 /**
84 * Last ACK sent to the peer (peer can't send more than this PID).
85 */
86 uint32_t last_ack_sent;
87
88 /**
89 * Last ACK sent towards the origin (for traffic towards leaf node).
90 */
91 uint32_t last_ack_recv;
92
93 /**
94 * Task to poll the peer in case of a lost ACK causes stall.
95 */
96 GNUNET_SCHEDULER_TaskIdentifier poll_task;
97
98 /**
99 * How frequently to poll for ACKs.
100 */
101 struct GNUNET_TIME_Relative poll_time;
102
103 /**
104 * Queued poll message, to cancel if not necessary anymore (got ACK).
105 */
106 struct CadetConnectionQueue *poll_msg;
107
108 /**
109 * Queued poll message, to cancel if not necessary anymore (got ACK).
110 */
111 struct CadetConnectionQueue *ack_msg;
112};
113
114/**
115 * Keep a record of the last messages sent on this connection.
116 */
117struct CadetConnectionPerformance
118{
119 /**
120 * Circular buffer for storing measurements.
121 */
122 double usecsperbyte[AVG_MSGS];
123
124 /**
125 * Running average of @c usecsperbyte.
126 */
127 double avg;
128
129 /**
130 * How many values of @c usecsperbyte are valid.
131 */
132 uint16_t size;
133
134 /**
135 * Index of the next "free" position in @c usecsperbyte.
136 */
137 uint16_t idx;
138};
139
140
141/**
142 * Struct containing all information regarding a connection to a peer.
143 */
144struct CadetConnection
145{
146 /**
147 * Tunnel this connection is part of.
148 */
149 struct CadetTunnel3 *t;
150
151 /**
152 * Flow control information for traffic fwd.
153 */
154 struct CadetFlowControl fwd_fc;
155
156 /**
157 * Flow control information for traffic bck.
158 */
159 struct CadetFlowControl bck_fc;
160
161 /**
162 * Measure connection performance on the endpoint.
163 */
164 struct CadetConnectionPerformance *perf;
165
166 /**
167 * ID of the connection.
168 */
169 struct GNUNET_CADET_Hash id;
170
171 /**
172 * State of the connection.
173 */
174 enum CadetConnectionState state;
175
176 /**
177 * Path being used for the tunnel. At the origin of the connection
178 * it's a pointer to the destination's path pool, otherwise just a copy.
179 */
180 struct CadetPeerPath *path;
181
182 /**
183 * Position of the local peer in the path.
184 */
185 unsigned int own_pos;
186
187 /**
188 * Task to keep the used paths alive at the owner,
189 * time tunnel out on all the other peers.
190 */
191 GNUNET_SCHEDULER_TaskIdentifier fwd_maintenance_task;
192
193 /**
194 * Task to keep the used paths alive at the destination,
195 * time tunnel out on all the other peers.
196 */
197 GNUNET_SCHEDULER_TaskIdentifier bck_maintenance_task;
198
199 /**
200 * Queue handle for maintainance traffic. One handle for FWD and BCK since
201 * one peer never needs to maintain both directions (no loopback connections).
202 */
203 struct CadetPeerQueue *maintenance_q;
204
205 /**
206 * Counter to do exponential backoff when creating a connection (max 64).
207 */
208 unsigned short create_retry;
209
210 /**
211 * Pending message count.
212 */
213 int pending_messages;
214
215 /**
216 * Destroy flag: if true, destroy on last message.
217 */
218 int destroy;
219};
220
221/**
222 * Handle for messages queued but not yet sent.
223 */
224struct CadetConnectionQueue
225{
226 /**
227 * Peer queue handle, to cancel if necessary.
228 */
229 struct CadetPeerQueue *q;
230
231 /**
232 * Was this a forced message? (Do not account for it)
233 */
234 int forced;
235
236 /**
237 * Continuation to call once sent.
238 */
239 GMC_sent cont;
240
241 /**
242 * Closure for @c cont.
243 */
244 void *cont_cls;
245};
246
247/******************************************************************************/
248/******************************* GLOBALS ***********************************/
249/******************************************************************************/
250
251/**
252 * Global handle to the statistics service.
253 */
254extern struct GNUNET_STATISTICS_Handle *stats;
255
256/**
257 * Local peer own ID (memory efficient handle).
258 */
259extern GNUNET_PEER_Id myid;
260
261/**
262 * Local peer own ID (full value).
263 */
264extern struct GNUNET_PeerIdentity my_full_id;
265
266/**
267 * Connections known, indexed by cid (CadetConnection).
268 */
269static struct GNUNET_CONTAINER_MultiHashMap *connections;
270
271/**
272 * How many connections are we willing to maintain.
273 * Local connections are always allowed, even if there are more connections than max.
274 */
275static unsigned long long max_connections;
276
277/**
278 * How many messages *in total* are we willing to queue, divide by number of
279 * connections to get connection queue size.
280 */
281static unsigned long long max_msgs_queue;
282
283/**
284 * How often to send path keepalives. Paths timeout after 4 missed.
285 */
286static struct GNUNET_TIME_Relative refresh_connection_time;
287
288/**
289 * How often to send path create / ACKs.
290 */
291static struct GNUNET_TIME_Relative create_connection_time;
292
293
294/******************************************************************************/
295/******************************** STATIC ***********************************/
296/******************************************************************************/
297
298#if 0 // avoid compiler warning for unused static function
299static void
300fc_debug (struct CadetFlowControl *fc)
301{
302 LOG (GNUNET_ERROR_TYPE_DEBUG, " IN: %u/%u\n",
303 fc->last_pid_recv, fc->last_ack_sent);
304 LOG (GNUNET_ERROR_TYPE_DEBUG, " OUT: %u/%u\n",
305 fc->last_pid_sent, fc->last_ack_recv);
306 LOG (GNUNET_ERROR_TYPE_DEBUG, " QUEUE: %u/%u\n",
307 fc->queue_n, fc->queue_max);
308}
309
310static void
311connection_debug (struct CadetConnection *c)
312{
313 if (NULL == c)
314 {
315 LOG (GNUNET_ERROR_TYPE_DEBUG, "*** DEBUG NULL CONNECTION ***\n");
316 return;
317 }
318 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s:%X\n",
319 peer2s (c->t->peer), GMC_2s (c));
320 LOG (GNUNET_ERROR_TYPE_DEBUG, " state: %u, pending msgs: %u\n",
321 c->state, c->pending_messages);
322 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD FC\n");
323 fc_debug (&c->fwd_fc);
324 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK FC\n");
325 fc_debug (&c->bck_fc);
326}
327#endif
328
329
330/**
331 * Schedule next keepalive task, taking in consideration
332 * the connection state and number of retries.
333 *
334 * @param c Connection for which to schedule the next keepalive.
335 * @param fwd Direction for the next keepalive.
336 */
337static void
338schedule_next_keepalive (struct CadetConnection *c, int fwd);
339
340
341/**
342 * Resets the connection timeout task, some other message has done the
343 * task's job.
344 * - For the first peer on the direction this means to send
345 * a keepalive or a path confirmation message (either create or ACK).
346 * - For all other peers, this means to destroy the connection,
347 * due to lack of activity.
348 * Starts the timeout if no timeout was running (connection just created).
349 *
350 * @param c Connection whose timeout to reset.
351 * @param fwd Is this forward?
352 */
353static void
354connection_reset_timeout (struct CadetConnection *c, int fwd);
355
356
357/**
358 * Get string description for tunnel state. Reentrant.
359 *
360 * @param s Tunnel state.
361 *
362 * @return String representation.
363 */
364static const char *
365GMC_state2s (enum CadetConnectionState s)
366{
367 switch (s)
368 {
369 case CADET_CONNECTION_NEW:
370 return "CADET_CONNECTION_NEW";
371 case CADET_CONNECTION_SENT:
372 return "CADET_CONNECTION_SENT";
373 case CADET_CONNECTION_ACK:
374 return "CADET_CONNECTION_ACK";
375 case CADET_CONNECTION_READY:
376 return "CADET_CONNECTION_READY";
377 case CADET_CONNECTION_DESTROYED:
378 return "CADET_CONNECTION_DESTROYED";
379 default:
380 return "CADET_CONNECTION_STATE_ERROR";
381 }
382}
383
384
385/**
386 * Initialize a Flow Control structure to the initial state.
387 *
388 * @param fc Flow Control structure to initialize.
389 */
390static void
391fc_init (struct CadetFlowControl *fc)
392{
393 fc->last_pid_sent = (uint32_t) -1; /* Next (expected) = 0 */
394 fc->last_pid_recv = (uint32_t) -1;
395 fc->last_ack_sent = (uint32_t) 0;
396 fc->last_ack_recv = (uint32_t) 0;
397 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
398 fc->poll_time = GNUNET_TIME_UNIT_SECONDS;
399 fc->queue_n = 0;
400 fc->queue_max = (max_msgs_queue / max_connections) + 1;
401}
402
403
404/**
405 * Find a connection.
406 *
407 * @param cid Connection ID.
408 */
409static struct CadetConnection *
410connection_get (const struct GNUNET_CADET_Hash *cid)
411{
412 return GNUNET_CONTAINER_multihashmap_get (connections, GM_h2hc (cid));
413}
414
415
416static void
417connection_change_state (struct CadetConnection* c,
418 enum CadetConnectionState state)
419{
420 LOG (GNUNET_ERROR_TYPE_DEBUG,
421 "Connection %s state %s -> %s\n",
422 GMC_2s (c), GMC_state2s (c->state), GMC_state2s (state));
423 if (CADET_CONNECTION_DESTROYED == c->state)
424 {
425 LOG (GNUNET_ERROR_TYPE_DEBUG, "state not changing anymore\n");
426 return;
427 }
428 c->state = state;
429 if (CADET_CONNECTION_READY == state)
430 c->create_retry = 1;
431}
432
433
434/**
435 * Callback called when a queued ACK message is sent.
436 *
437 * @param cls Closure (FC).
438 * @param c Connection this message was on.
439 * @param q Queue handler this call invalidates.
440 * @param type Type of message sent.
441 * @param fwd Was this a FWD going message?
442 * @param size Size of the message.
443 */
444static void
445ack_sent (void *cls,
446 struct CadetConnection *c,
447 struct CadetConnectionQueue *q,
448 uint16_t type, int fwd, size_t size)
449{
450 struct CadetFlowControl *fc = cls;
451
452 fc->ack_msg = NULL;
453}
454
455
456/**
457 * Send an ACK on the connection, informing the predecessor about
458 * the available buffer space. Should not be called in case the peer
459 * is origin (no predecessor) in the @c fwd direction.
460 *
461 * Note that for fwd ack, the FWD mean forward *traffic* (root->dest),
462 * the ACK itself goes "back" (dest->root).
463 *
464 * @param c Connection on which to send the ACK.
465 * @param buffer How much space free to advertise?
466 * @param fwd Is this FWD ACK? (Going dest -> root)
467 * @param force Don't optimize out.
468 */
469static void
470send_ack (struct CadetConnection *c, unsigned int buffer, int fwd, int force)
471{
472 struct CadetFlowControl *next_fc;
473 struct CadetFlowControl *prev_fc;
474 struct GNUNET_CADET_ACK msg;
475 uint32_t ack;
476 int delta;
477
478 /* If origin, there is no connection to send ACKs. Wrong function! */
479 if (GMC_is_origin (c, fwd))
480 {
481 LOG (GNUNET_ERROR_TYPE_DEBUG, "connection %s is origin in %s\n",
482 GMC_2s (c), GM_f2s (fwd));
483 GNUNET_break (0);
484 return;
485 }
486
487 next_fc = fwd ? &c->fwd_fc : &c->bck_fc;
488 prev_fc = fwd ? &c->bck_fc : &c->fwd_fc;
489
490 LOG (GNUNET_ERROR_TYPE_DEBUG, "connection send %s ack on %s\n",
491 GM_f2s (fwd), GMC_2s (c));
492
493 /* Check if we need to transmit the ACK. */
494 delta = prev_fc->last_ack_sent - prev_fc->last_pid_recv;
495 if (3 < delta && buffer < delta && GNUNET_NO == force)
496 {
497 LOG (GNUNET_ERROR_TYPE_DEBUG, "Not sending ACK, buffer > 3\n");
498 LOG (GNUNET_ERROR_TYPE_DEBUG,
499 " last pid recv: %u, last ack sent: %u\n",
500 prev_fc->last_pid_recv, prev_fc->last_ack_sent);
501 return;
502 }
503
504 /* Ok, ACK might be necessary, what PID to ACK? */
505 ack = prev_fc->last_pid_recv + buffer;
506 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK %u\n", ack);
507 LOG (GNUNET_ERROR_TYPE_DEBUG,
508 " last pid %u, last ack %u, qmax %u, q %u\n",
509 prev_fc->last_pid_recv, prev_fc->last_ack_sent,
510 next_fc->queue_max, next_fc->queue_n);
511 if (ack == prev_fc->last_ack_sent && GNUNET_NO == force)
512 {
513 LOG (GNUNET_ERROR_TYPE_DEBUG, "Not sending FWD ACK, not needed\n");
514 return;
515 }
516
517 /* Check if message is already in queue */
518 if (NULL != prev_fc->ack_msg)
519 {
520 if (GM_is_pid_bigger (ack, prev_fc->last_ack_sent))
521 {
522 LOG (GNUNET_ERROR_TYPE_DEBUG, " canceling old ACK\n");
523 GMC_cancel (prev_fc->ack_msg);
524 /* GMC_cancel triggers ack_sent(), which clears fc->ack_msg */
525 }
526 else
527 {
528 LOG (GNUNET_ERROR_TYPE_DEBUG, " same ACK already in queue\n");
529 return;
530 }
531 }
532
533 prev_fc->last_ack_sent = ack;
534
535 /* Build ACK message and send on connection */
536 msg.header.size = htons (sizeof (msg));
537 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_ACK);
538 msg.ack = htonl (ack);
539 msg.cid = c->id;
540
541 prev_fc->ack_msg = GMC_send_prebuilt_message (&msg.header,
542 GNUNET_MESSAGE_TYPE_CADET_ACK,
543 ack, c, !fwd, GNUNET_YES,
544 &ack_sent, prev_fc);
545}
546
547
548/**
549 * Callback called when a connection queued message is sent.
550 *
551 * Calculates the average time and connection packet tracking.
552 *
553 * @param cls Closure (ConnectionQueue Handle).
554 * @param c Connection this message was on.
555 * @param sent Was it really sent? (Could have been canceled)
556 * @param type Type of message sent.
557 * @param pid Packet ID, or 0 if not applicable (create, destroy, etc).
558 * @param fwd Was this a FWD going message?
559 * @param size Size of the message.
560 * @param wait Time spent waiting for core (only the time for THIS message)
561 */
562static void
563conn_message_sent (void *cls,
564 struct CadetConnection *c, int sent,
565 uint16_t type, uint32_t pid, int fwd, size_t size,
566 struct GNUNET_TIME_Relative wait)
567{
568 struct CadetConnectionPerformance *p;
569 struct CadetFlowControl *fc;
570 struct CadetConnectionQueue *q = cls;
571 double usecsperbyte;
572 int forced;
573
574 LOG (GNUNET_ERROR_TYPE_DEBUG, "connection message_sent\n");
575
576 fc = fwd ? &c->fwd_fc : &c->bck_fc;
577 LOG (GNUNET_ERROR_TYPE_DEBUG, " %ssent %s %s\n",
578 sent ? "" : "not ", GM_f2s (fwd), GM_m2s (type));
579 if (NULL != q)
580 {
581 forced = q->forced;
582 if (NULL != q->cont)
583 {
584 LOG (GNUNET_ERROR_TYPE_DEBUG, " calling cont\n");
585 q->cont (q->cont_cls, c, q, type, fwd, size);
586 }
587 GNUNET_free (q);
588 }
589 else if (type == GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED)
590 {
591 /* If NULL == q and ENCRYPTED == type, message must have been ch_mngmnt */
592 forced = GNUNET_YES;
593 }
594 else
595 {
596 forced = GNUNET_NO;
597 }
598 if (NULL == c)
599 {
600 GNUNET_break (type == GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN ||
601 type == GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY);
602 LOG (GNUNET_ERROR_TYPE_ERROR, "Message %s sent on NULL connection!\n",
603 GM_m2s (type));
604 return;
605 }
606 LOG (GNUNET_ERROR_TYPE_DEBUG, " C_P- %p %u\n", c, c->pending_messages);
607 c->pending_messages--;
608 if (GNUNET_YES == c->destroy && 0 == c->pending_messages)
609 {
610 LOG (GNUNET_ERROR_TYPE_DEBUG, "! destroying connection!\n");
611 GMC_destroy (c);
612 return;
613 }
614 /* Send ACK if needed, after accounting for sent ID in fc->queue_n */
615 switch (type)
616 {
617 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE:
618 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_ACK:
619 c->maintenance_q = NULL;
620 /* Don't trigger a keepalive for sent ACKs, only SYN and SYNACKs */
621 if (GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE == type || !fwd)
622 schedule_next_keepalive (c, fwd);
623 break;
624
625 case GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED:
626 if (GNUNET_YES == sent)
627 {
628 GNUNET_assert (NULL != q);
629 fc->last_pid_sent = pid; // FIXME
630 GMC_send_ack (c, fwd, GNUNET_NO);
631 connection_reset_timeout (c, fwd);
632 }
633
634 LOG (GNUNET_ERROR_TYPE_DEBUG, "! Q_N- %p %u\n", fc, fc->queue_n);
635 if (GNUNET_NO == forced)
636 {
637 fc->queue_n--;
638 LOG (GNUNET_ERROR_TYPE_DEBUG,
639 "! accounting pid %u\n",
640 fc->last_pid_sent);
641 }
642 else
643 {
644 LOG (GNUNET_ERROR_TYPE_DEBUG,
645 "! forced, Q_N not accounting pid %u\n",
646 fc->last_pid_sent);
647 }
648 break;
649
650 case GNUNET_MESSAGE_TYPE_CADET_KX:
651 if (GNUNET_YES == sent)
652 connection_reset_timeout (c, fwd);
653 break;
654
655 case GNUNET_MESSAGE_TYPE_CADET_POLL:
656 fc->poll_msg = NULL;
657 break;
658
659 case GNUNET_MESSAGE_TYPE_CADET_ACK:
660 fc->ack_msg = NULL;
661 break;
662
663 default:
664 break;
665 }
666 LOG (GNUNET_ERROR_TYPE_DEBUG, "! message sent!\n");
667
668 if (NULL == c->perf)
669 return; /* Only endpoints are interested in timing. */
670
671 p = c->perf;
672 usecsperbyte = ((double) wait.rel_value_us) / size;
673 if (p->size == AVG_MSGS)
674 {
675 /* Array is full. Substract oldest value, add new one and store. */
676 p->avg -= (p->usecsperbyte[p->idx] / AVG_MSGS);
677 p->usecsperbyte[p->idx] = usecsperbyte;
678 p->avg += (p->usecsperbyte[p->idx] / AVG_MSGS);
679 }
680 else
681 {
682 /* Array not yet full. Add current value to avg and store. */
683 p->usecsperbyte[p->idx] = usecsperbyte;
684 p->avg *= p->size;
685 p->avg += p->usecsperbyte[p->idx];
686 p->size++;
687 p->avg /= p->size;
688 }
689 p->idx = (p->idx + 1) % AVG_MSGS;
690}
691
692
693/**
694 * Get the previous hop in a connection
695 *
696 * @param c Connection.
697 *
698 * @return Previous peer in the connection.
699 */
700static struct CadetPeer *
701get_prev_hop (const struct CadetConnection *c)
702{
703 GNUNET_PEER_Id id;
704
705 LOG (GNUNET_ERROR_TYPE_DEBUG, " get prev hop %s [%u/%u]\n",
706 GMC_2s (c), c->own_pos, c->path->length);
707 if (0 == c->own_pos || c->path->length < 2)
708 id = c->path->peers[0];
709 else
710 id = c->path->peers[c->own_pos - 1];
711
712 LOG (GNUNET_ERROR_TYPE_DEBUG, " ID: %s (%u)\n",
713 GNUNET_i2s (GNUNET_PEER_resolve2 (id)), id);
714
715 return GMP_get_short (id);
716}
717
718
719/**
720 * Get the next hop in a connection
721 *
722 * @param c Connection.
723 *
724 * @return Next peer in the connection.
725 */
726static struct CadetPeer *
727get_next_hop (const struct CadetConnection *c)
728{
729 GNUNET_PEER_Id id;
730
731 LOG (GNUNET_ERROR_TYPE_DEBUG, " get next hop %s [%u/%u]\n",
732 GMC_2s (c), c->own_pos, c->path->length);
733 if ((c->path->length - 1) == c->own_pos || c->path->length < 2)
734 id = c->path->peers[c->path->length - 1];
735 else
736 id = c->path->peers[c->own_pos + 1];
737
738 LOG (GNUNET_ERROR_TYPE_DEBUG, " ID: %s (%u)\n",
739 GNUNET_i2s (GNUNET_PEER_resolve2 (id)), id);
740
741 return GMP_get_short (id);
742}
743
744
745/**
746 * Get the hop in a connection.
747 *
748 * @param c Connection.
749 * @param fwd Next hop?
750 *
751 * @return Next peer in the connection.
752 */
753static struct CadetPeer *
754get_hop (struct CadetConnection *c, int fwd)
755{
756 if (fwd)
757 return get_next_hop (c);
758 return get_prev_hop (c);
759}
760
761
762/**
763 * Is traffic coming from this sender 'FWD' traffic?
764 *
765 * @param c Connection to check.
766 * @param sender Peer identity of neighbor.
767 *
768 * @return #GNUNET_YES in case the sender is the 'prev' hop and therefore
769 * the traffic is 'FWD'.
770 * #GNUNET_NO for BCK.
771 * #GNUNET_SYSERR for errors.
772 */
773static int
774is_fwd (const struct CadetConnection *c,
775 const struct GNUNET_PeerIdentity *sender)
776{
777 GNUNET_PEER_Id id;
778
779 id = GNUNET_PEER_search (sender);
780 if (GMP_get_short_id (get_prev_hop (c)) == id)
781 return GNUNET_YES;
782
783 if (GMP_get_short_id (get_next_hop (c)) == id)
784 return GNUNET_NO;
785
786 GNUNET_break (0);
787 return GNUNET_SYSERR;
788}
789
790
791/**
792 * Sends a CONNECTION ACK message in reponse to a received CONNECTION_CREATE
793 * or a first CONNECTION_ACK directed to us.
794 *
795 * @param connection Connection to confirm.
796 * @param fwd Should we send it FWD? (root->dest)
797 * (First (~SYNACK) goes BCK, second (~ACK) goes FWD)
798 */
799static void
800send_connection_ack (struct CadetConnection *connection, int fwd)
801{
802 struct CadetTunnel3 *t;
803
804 t = connection->t;
805 LOG (GNUNET_ERROR_TYPE_INFO, "===> {%14s ACK} on connection %s\n",
806 GM_f2s (!fwd), GMC_2s (connection));
807 GMP_queue_add (get_hop (connection, fwd), NULL,
808 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_ACK,
809 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_ACK, 0,
810 sizeof (struct GNUNET_CADET_ConnectionACK),
811 connection, fwd, &conn_message_sent, NULL);
812 connection->pending_messages++;
813 if (CADET_TUNNEL3_NEW == GMT_get_cstate (t))
814 GMT_change_cstate (t, CADET_TUNNEL3_WAITING);
815 if (CADET_CONNECTION_READY != connection->state)
816 connection_change_state (connection, CADET_CONNECTION_SENT);
817}
818
819
820/**
821 * Send a notification that a connection is broken.
822 *
823 * @param c Connection that is broken.
824 * @param id1 Peer that has disconnected.
825 * @param id2 Peer that has disconnected.
826 * @param fwd Direction towards which to send it.
827 */
828static void
829send_broken (struct CadetConnection *c,
830 const struct GNUNET_PeerIdentity *id1,
831 const struct GNUNET_PeerIdentity *id2,
832 int fwd)
833{
834 struct GNUNET_CADET_ConnectionBroken msg;
835
836 msg.header.size = htons (sizeof (struct GNUNET_CADET_ConnectionBroken));
837 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN);
838 msg.cid = c->id;
839 msg.peer1 = *id1;
840 msg.peer2 = *id2;
841 GMC_send_prebuilt_message (&msg.header,
842 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN, 0,
843 c, fwd, GNUNET_YES, NULL, NULL);
844}
845
846
847/**
848 * Send a notification that a connection is broken, when a connection
849 * isn't even known to the local peer.
850 *
851 * @param connection_id Connection ID.
852 * @param id1 Peer that has disconnected, probably local peer.
853 * @param id2 Peer that has disconnected can be NULL if unknown.
854 * @param peer Peer to notify (neighbor who sent the connection).
855 */
856static void
857send_broken_unknown (const struct GNUNET_CADET_Hash *connection_id,
858 const struct GNUNET_PeerIdentity *id1,
859 const struct GNUNET_PeerIdentity *id2,
860 const struct GNUNET_PeerIdentity *peer_id)
861{
862 struct GNUNET_CADET_ConnectionBroken *msg;
863 struct CadetPeer *neighbor;
864
865 LOG (GNUNET_ERROR_TYPE_INFO, "===> BROKEN on unknown connection %s\n",
866 GNUNET_h2s (GM_h2hc (connection_id)));
867
868 msg = GNUNET_new (struct GNUNET_CADET_ConnectionBroken);
869 msg->header.size = htons (sizeof (struct GNUNET_CADET_ConnectionBroken));
870 msg->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN);
871 msg->cid = *connection_id;
872 msg->peer1 = *id1;
873 if (NULL != id2)
874 msg->peer2 = *id2;
875 else
876 memset (&msg->peer2, 0, sizeof (msg->peer2));
877 neighbor = GMP_get (peer_id);
878 GMP_queue_add (neighbor, msg,
879 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN,
880 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN, 2,
881 sizeof (struct GNUNET_CADET_ConnectionBroken),
882 NULL, GNUNET_SYSERR, /* connection, fwd */
883 NULL, NULL); /* continuation */
884}
885
886
887/**
888 * Send keepalive packets for a connection.
889 *
890 * @param c Connection to keep alive..
891 * @param fwd Is this a FWD keepalive? (owner -> dest).
892 */
893static void
894send_connection_keepalive (struct CadetConnection *c, int fwd)
895{
896 struct GNUNET_MessageHeader msg;
897 struct CadetFlowControl *fc;
898
899 LOG (GNUNET_ERROR_TYPE_INFO,
900 "keepalive %s for connection %s\n",
901 GM_f2s (fwd), GMC_2s (c));
902
903 fc = fwd ? &c->fwd_fc : &c->bck_fc;
904 if (0 < fc->queue_n)
905 {
906 LOG (GNUNET_ERROR_TYPE_INFO, "not sending keepalive, traffic in queue\n");
907 }
908
909 GNUNET_STATISTICS_update (stats, "# keepalives sent", 1, GNUNET_NO);
910
911 GNUNET_assert (NULL != c->t);
912 msg.size = htons (sizeof (msg));
913 msg.type = htons (GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE);
914
915 GNUNET_assert (NULL ==
916 GMT_send_prebuilt_message (&msg, c->t, c,
917 GNUNET_NO, NULL, NULL));
918}
919
920
921/**
922 * Send CONNECTION_{CREATE/ACK} packets for a connection.
923 *
924 * @param c Connection for which to send the message.
925 * @param fwd If #GNUNET_YES, send CREATE, otherwise send ACK.
926 */
927static void
928connection_recreate (struct CadetConnection *c, int fwd)
929{
930 LOG (GNUNET_ERROR_TYPE_DEBUG, "sending connection recreate\n");
931 if (fwd)
932 GMC_send_create (c);
933 else
934 send_connection_ack (c, GNUNET_NO);
935}
936
937
938/**
939 * Generic connection timer management.
940 * Depending on the role of the peer in the connection will send the
941 * appropriate message (build or keepalive)
942 *
943 * @param c Conncetion to maintain.
944 * @param fwd Is FWD?
945 */
946static void
947connection_maintain (struct CadetConnection *c, int fwd)
948{
949 if (GNUNET_NO != c->destroy)
950 return;
951
952 if (CADET_TUNNEL3_SEARCHING == GMT_get_cstate (c->t))
953 {
954 /* TODO DHT GET with RO_BART */
955 return;
956 }
957 switch (c->state)
958 {
959 case CADET_CONNECTION_NEW:
960 GNUNET_break (0);
961 /* fall-through */
962 case CADET_CONNECTION_SENT:
963 connection_recreate (c, fwd);
964 break;
965 case CADET_CONNECTION_READY:
966 send_connection_keepalive (c, fwd);
967 break;
968 default:
969 break;
970 }
971}
972
973
974
975/**
976 * Keep the connection alive.
977 *
978 * @param c Connection to keep alive.
979 * @param fwd Direction.
980 * @param shutdown Are we shutting down? (Don't send traffic)
981 * Non-zero value for true, not necessarily GNUNET_YES.
982 */
983static void
984connection_keepalive (struct CadetConnection *c, int fwd, int shutdown)
985{
986 LOG (GNUNET_ERROR_TYPE_DEBUG, "%s keepalive for %s\n",
987 GM_f2s (fwd), GMC_2s (c));
988
989 if (fwd)
990 c->fwd_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
991 else
992 c->bck_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
993
994 if (GNUNET_NO != shutdown)
995 return;
996
997 connection_maintain (c, fwd);
998
999 /* Next execution will be scheduled by message_sent */
1000}
1001
1002
1003/**
1004 * Keep the connection alive in the FWD direction.
1005 *
1006 * @param cls Closure (connection to keepalive).
1007 * @param tc TaskContext.
1008 */
1009static void
1010connection_fwd_keepalive (void *cls,
1011 const struct GNUNET_SCHEDULER_TaskContext *tc)
1012{
1013 connection_keepalive ((struct CadetConnection *) cls,
1014 GNUNET_YES,
1015 tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN);
1016}
1017
1018
1019/**
1020 * Keep the connection alive in the BCK direction.
1021 *
1022 * @param cls Closure (connection to keepalive).
1023 * @param tc TaskContext.
1024 */
1025static void
1026connection_bck_keepalive (void *cls,
1027 const struct GNUNET_SCHEDULER_TaskContext *tc)
1028{
1029 connection_keepalive ((struct CadetConnection *) cls,
1030 GNUNET_NO,
1031 tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN);
1032}
1033
1034
1035/**
1036 * Schedule next keepalive task, taking in consideration
1037 * the connection state and number of retries.
1038 *
1039 * If the peer is not the origin, do nothing.
1040 *
1041 * @param c Connection for which to schedule the next keepalive.
1042 * @param fwd Direction for the next keepalive.
1043 */
1044static void
1045schedule_next_keepalive (struct CadetConnection *c, int fwd)
1046{
1047 struct GNUNET_TIME_Relative delay;
1048 GNUNET_SCHEDULER_TaskIdentifier *task_id;
1049 GNUNET_SCHEDULER_Task keepalive_task;
1050
1051 if (GNUNET_NO == GMC_is_origin (c, fwd))
1052 return;
1053
1054 /* Calculate delay to use, depending on the state of the connection */
1055 if (CADET_CONNECTION_READY == c->state)
1056 {
1057 delay = refresh_connection_time;
1058 }
1059 else
1060 {
1061 if (1 > c->create_retry)
1062 c->create_retry = 1;
1063 delay = GNUNET_TIME_relative_multiply (create_connection_time,
1064 c->create_retry);
1065 if (c->create_retry < 64)
1066 c->create_retry *= 2;
1067 }
1068
1069 /* Select direction-dependent parameters */
1070 if (GNUNET_YES == fwd)
1071 {
1072 task_id = &c->fwd_maintenance_task;
1073 keepalive_task = &connection_fwd_keepalive;
1074 }
1075 else
1076 {
1077 task_id = &c->bck_maintenance_task;
1078 keepalive_task = &connection_bck_keepalive;
1079 }
1080
1081 /* Check that no one scheduled it before us */
1082 if (GNUNET_SCHEDULER_NO_TASK != *task_id)
1083 {
1084 /* No need for a _break. It can happen for instance when sending a SYNACK
1085 * for a duplicate SYN: the first SYNACK scheduled the task. */
1086 GNUNET_SCHEDULER_cancel (*task_id);
1087 }
1088
1089 /* Schedule the task */
1090 *task_id = GNUNET_SCHEDULER_add_delayed (delay, keepalive_task, c);
1091 LOG (GNUNET_ERROR_TYPE_DEBUG, "next keepalive in %s\n",
1092 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
1093}
1094
1095
1096/**
1097 * @brief Re-initiate traffic on this connection if necessary.
1098 *
1099 * Check if there is traffic queued towards this peer
1100 * and the core transmit handle is NULL (traffic was stalled).
1101 * If so, call core tmt rdy.
1102 *
1103 * @param c Connection on which initiate traffic.
1104 * @param fwd Is this about fwd traffic?
1105 */
1106static void
1107connection_unlock_queue (struct CadetConnection *c, int fwd)
1108{
1109 struct CadetPeer *peer;
1110
1111 LOG (GNUNET_ERROR_TYPE_DEBUG,
1112 "connection_unlock_queue %s on %s\n",
1113 GM_f2s (fwd), GMC_2s (c));
1114
1115 if (GMC_is_terminal (c, fwd))
1116 {
1117 LOG (GNUNET_ERROR_TYPE_DEBUG, " is terminal!\n");
1118 return;
1119 }
1120
1121 peer = get_hop (c, fwd);
1122 GMP_queue_unlock (peer, c);
1123}
1124
1125
1126/**
1127 * Cancel all transmissions that belong to a certain connection.
1128 *
1129 * If the connection is scheduled for destruction and no more messages are left,
1130 * the connection will be destroyed by the continuation call.
1131 *
1132 * @param c Connection which to cancel. Might be destroyed during this call.
1133 * @param fwd Cancel fwd traffic?
1134 */
1135static void
1136connection_cancel_queues (struct CadetConnection *c, int fwd)
1137{
1138 struct CadetFlowControl *fc;
1139 struct CadetPeer *peer;
1140
1141 LOG (GNUNET_ERROR_TYPE_DEBUG,
1142 " *** Cancel %s queues for connection %s\n",
1143 GM_f2s (fwd), GMC_2s (c));
1144 if (NULL == c)
1145 {
1146 GNUNET_break (0);
1147 return;
1148 }
1149
1150 fc = fwd ? &c->fwd_fc : &c->bck_fc;
1151 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task)
1152 {
1153 GNUNET_SCHEDULER_cancel (fc->poll_task);
1154 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
1155 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** Cancel POLL in ccq for fc %p\n", fc);
1156 }
1157 peer = get_hop (c, fwd);
1158 GMP_queue_cancel (peer, c);
1159}
1160
1161
1162/**
1163 * Function called if a connection has been stalled for a while,
1164 * possibly due to a missed ACK. Poll the neighbor about its ACK status.
1165 *
1166 * @param cls Closure (poll ctx).
1167 * @param tc TaskContext.
1168 */
1169static void
1170connection_poll (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
1171
1172
1173/**
1174 * Callback called when a queued POLL message is sent.
1175 *
1176 * @param cls Closure (FC).
1177 * @param c Connection this message was on.
1178 * @param q Queue handler this call invalidates.
1179 * @param type Type of message sent.
1180 * @param fwd Was this a FWD going message?
1181 * @param size Size of the message.
1182 */
1183static void
1184poll_sent (void *cls,
1185 struct CadetConnection *c,
1186 struct CadetConnectionQueue *q,
1187 uint16_t type, int fwd, size_t size)
1188{
1189 struct CadetFlowControl *fc = cls;
1190
1191 if (2 == c->destroy)
1192 {
1193 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL canceled on shutdown\n");
1194 return;
1195 }
1196 LOG (GNUNET_ERROR_TYPE_DEBUG,
1197 " *** POLL sent for , scheduling new one!\n");
1198 fc->poll_msg = NULL;
1199 fc->poll_time = GNUNET_TIME_STD_BACKOFF (fc->poll_time);
1200 fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time,
1201 &connection_poll, fc);
1202 LOG (GNUNET_ERROR_TYPE_DEBUG, " task %u\n", fc->poll_task);
1203
1204}
1205
1206/**
1207 * Function called if a connection has been stalled for a while,
1208 * possibly due to a missed ACK. Poll the neighbor about its ACK status.
1209 *
1210 * @param cls Closure (poll ctx).
1211 * @param tc TaskContext.
1212 */
1213static void
1214connection_poll (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1215{
1216 struct CadetFlowControl *fc = cls;
1217 struct GNUNET_CADET_Poll msg;
1218 struct CadetConnection *c;
1219
1220 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
1221 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1222 {
1223 return;
1224 }
1225
1226 c = fc->c;
1227 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** Polling connection %s %s\n",
1228 GMC_2s (c), fc == &c->fwd_fc ? "FWD" : "BCK");
1229
1230 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_POLL);
1231 msg.header.size = htons (sizeof (msg));
1232 msg.pid = htonl (fc->last_pid_sent);
1233 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** last pid sent: %u!\n", fc->last_pid_sent);
1234 fc->poll_msg =
1235 GMC_send_prebuilt_message (&msg.header,
1236 GNUNET_MESSAGE_TYPE_CADET_POLL,
1237 fc->last_pid_sent,
1238 c, fc == &c->fwd_fc, GNUNET_YES,
1239 &poll_sent, fc);
1240}
1241
1242
1243/**
1244 * Timeout function due to lack of keepalive/traffic from the owner.
1245 * Destroys connection if called.
1246 *
1247 * @param cls Closure (connection to destroy).
1248 * @param tc TaskContext.
1249 */
1250static void
1251connection_fwd_timeout (void *cls,
1252 const struct GNUNET_SCHEDULER_TaskContext *tc)
1253{
1254 struct CadetConnection *c = cls;
1255
1256 c->fwd_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
1257 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1258 return;
1259
1260 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s FWD timed out. Destroying.\n",
1261 GMC_2s (c));
1262 if (GMC_is_origin (c, GNUNET_YES)) /* If local, leave. */
1263 {
1264 GNUNET_break (0);
1265 return;
1266 }
1267
1268 GMC_destroy (c);
1269}
1270
1271
1272/**
1273 * Timeout function due to lack of keepalive/traffic from the destination.
1274 * Destroys connection if called.
1275 *
1276 * @param cls Closure (connection to destroy).
1277 * @param tc TaskContext
1278 */
1279static void
1280connection_bck_timeout (void *cls,
1281 const struct GNUNET_SCHEDULER_TaskContext *tc)
1282{
1283 struct CadetConnection *c = cls;
1284
1285 c->bck_maintenance_task = GNUNET_SCHEDULER_NO_TASK;
1286 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1287 return;
1288
1289 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s BCK timed out. Destroying.\n",
1290 GMC_2s (c));
1291
1292 if (GMC_is_origin (c, GNUNET_NO)) /* If local, leave. */
1293 {
1294 GNUNET_break (0);
1295 return;
1296 }
1297
1298 GMC_destroy (c);
1299}
1300
1301
1302/**
1303 * Resets the connection timeout task, some other message has done the
1304 * task's job.
1305 * - For the first peer on the direction this means to send
1306 * a keepalive or a path confirmation message (either create or ACK).
1307 * - For all other peers, this means to destroy the connection,
1308 * due to lack of activity.
1309 * Starts the timeout if no timeout was running (connection just created).
1310 *
1311 * @param c Connection whose timeout to reset.
1312 * @param fwd Is this forward?
1313 *
1314 * TODO use heap to improve efficiency of scheduler.
1315 */
1316static void
1317connection_reset_timeout (struct CadetConnection *c, int fwd)
1318{
1319 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connection %s reset timeout\n", GM_f2s (fwd));
1320
1321 if (GMC_is_origin (c, fwd)) /* Startpoint */
1322 {
1323 schedule_next_keepalive (c, fwd);
1324 }
1325 else /* Relay, endpoint. */
1326 {
1327 struct GNUNET_TIME_Relative delay;
1328 GNUNET_SCHEDULER_TaskIdentifier *ti;
1329 GNUNET_SCHEDULER_Task f;
1330
1331 ti = fwd ? &c->fwd_maintenance_task : &c->bck_maintenance_task;
1332
1333 if (GNUNET_SCHEDULER_NO_TASK != *ti)
1334 GNUNET_SCHEDULER_cancel (*ti);
1335 delay = GNUNET_TIME_relative_multiply (refresh_connection_time, 4);
1336 f = fwd ? &connection_fwd_timeout : &connection_bck_timeout;
1337 *ti = GNUNET_SCHEDULER_add_delayed (delay, f, c);
1338 }
1339}
1340
1341
1342/**
1343 * Add the connection to the list of both neighbors.
1344 *
1345 * @param c Connection.
1346 *
1347 * @return #GNUNET_OK if everything went fine
1348 * #GNUNET_SYSERR if the was an error and @c c is malformed.
1349 */
1350static int
1351register_neighbors (struct CadetConnection *c)
1352{
1353 struct CadetPeer *next_peer;
1354 struct CadetPeer *prev_peer;
1355
1356 next_peer = get_next_hop (c);
1357 prev_peer = get_prev_hop (c);
1358
1359 LOG (GNUNET_ERROR_TYPE_DEBUG, "register neighbors for connection %s\n",
1360 GMC_2s (c));
1361 path_debug (c->path);
1362 LOG (GNUNET_ERROR_TYPE_DEBUG, "own pos %u\n", c->own_pos);
1363 LOG (GNUNET_ERROR_TYPE_DEBUG, "putting connection %s to next peer %p\n",
1364 GMC_2s (c), next_peer);
1365 LOG (GNUNET_ERROR_TYPE_DEBUG, "next peer %p %s\n", next_peer, GMP_2s (next_peer));
1366 LOG (GNUNET_ERROR_TYPE_DEBUG, "putting connection %s to prev peer %p\n",
1367 GMC_2s (c), prev_peer);
1368 LOG (GNUNET_ERROR_TYPE_DEBUG, "prev peer %p %s\n", prev_peer, GMP_2s (prev_peer));
1369
1370 if (GNUNET_NO == GMP_is_neighbor (next_peer)
1371 || GNUNET_NO == GMP_is_neighbor (prev_peer))
1372 {
1373 if (GMC_is_origin (c, GNUNET_YES))
1374 GNUNET_STATISTICS_update (stats, "# local bad paths", 1, GNUNET_NO);
1375 GNUNET_STATISTICS_update (stats, "# bad paths", 1, GNUNET_NO);
1376
1377 LOG (GNUNET_ERROR_TYPE_DEBUG, " register neighbors failed\n");
1378 LOG (GNUNET_ERROR_TYPE_DEBUG, " prev: %s, neighbor?: %d\n",
1379 GMP_2s (prev_peer), GMP_is_neighbor (prev_peer));
1380 LOG (GNUNET_ERROR_TYPE_DEBUG, " next: %s, neighbor?: %d\n",
1381 GMP_2s (next_peer), GMP_is_neighbor (next_peer));
1382 return GNUNET_SYSERR;
1383 }
1384
1385 GMP_add_connection (next_peer, c);
1386 GMP_add_connection (prev_peer, c);
1387
1388 return GNUNET_OK;
1389}
1390
1391
1392/**
1393 * Remove the connection from the list of both neighbors.
1394 *
1395 * @param c Connection.
1396 */
1397static void
1398unregister_neighbors (struct CadetConnection *c)
1399{
1400 struct CadetPeer *peer;
1401
1402 peer = get_next_hop (c);
1403 if (GNUNET_OK != GMP_remove_connection (peer, c))
1404 {
1405 GNUNET_assert (CADET_CONNECTION_NEW == c->state
1406 || CADET_CONNECTION_DESTROYED == c->state);
1407 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate: %u\n", c->state);
1408 if (NULL != c->t) GMT_debug (c->t);
1409 }
1410
1411 peer = get_prev_hop (c);
1412 if (GNUNET_OK != GMP_remove_connection (peer, c))
1413 {
1414 GNUNET_assert (CADET_CONNECTION_NEW == c->state
1415 || CADET_CONNECTION_DESTROYED == c->state);
1416 LOG (GNUNET_ERROR_TYPE_DEBUG, " cstate: %u\n", c->state);
1417 if (NULL != c->t) GMT_debug (c->t);
1418 }
1419}
1420
1421
1422/**
1423 * Bind the connection to the peer and the tunnel to that peer.
1424 *
1425 * If the peer has no tunnel, create one. Update tunnel and connection
1426 * data structres to reflect new status.
1427 *
1428 * @param c Connection.
1429 * @param peer Peer.
1430 */
1431static void
1432add_to_peer (struct CadetConnection *c, struct CadetPeer *peer)
1433{
1434 GMP_add_tunnel (peer);
1435 c->t = GMP_get_tunnel (peer);
1436 GMT_add_connection (c->t, c);
1437}
1438
1439
1440/**
1441 * Builds a path from a PeerIdentity array.
1442 *
1443 * @param peers PeerIdentity array.
1444 * @param size Size of the @c peers array.
1445 * @param own_pos Output parameter: own position in the path.
1446 *
1447 * @return Fixed and shortened path.
1448 */
1449static struct CadetPeerPath *
1450build_path_from_peer_ids (struct GNUNET_PeerIdentity *peers,
1451 unsigned int size,
1452 unsigned int *own_pos)
1453{
1454 struct CadetPeerPath *path;
1455 GNUNET_PEER_Id shortid;
1456 unsigned int i;
1457 unsigned int j;
1458 unsigned int offset;
1459
1460 /* Create path */
1461 LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating path...\n");
1462 path = path_new (size);
1463 *own_pos = 0;
1464 offset = 0;
1465 for (i = 0; i < size; i++)
1466 {
1467 LOG (GNUNET_ERROR_TYPE_DEBUG, " - %u: taking %s\n",
1468 i, GNUNET_i2s (&peers[i]));
1469 shortid = GNUNET_PEER_intern (&peers[i]);
1470
1471 /* Check for loops / duplicates */
1472 for (j = 0; j < i - offset; j++)
1473 {
1474 if (path->peers[j] == shortid)
1475 {
1476 LOG (GNUNET_ERROR_TYPE_DEBUG, " already exists at pos %u\n", j);
1477 offset = i - j;
1478 LOG (GNUNET_ERROR_TYPE_DEBUG, " offset now %u\n", offset);
1479 GNUNET_PEER_change_rc (shortid, -1);
1480 }
1481 }
1482 LOG (GNUNET_ERROR_TYPE_DEBUG, " storing at %u\n", i - offset);
1483 path->peers[i - offset] = shortid;
1484 if (path->peers[i - offset] == myid)
1485 *own_pos = i - offset;
1486 }
1487 path->length -= offset;
1488
1489 if (path->peers[*own_pos] != myid)
1490 {
1491 /* create path: self not found in path through self */
1492 GNUNET_break_op (0);
1493 path_destroy (path);
1494 return NULL;
1495 }
1496
1497 return path;
1498}
1499
1500
1501/**
1502 * Log receipt of message on stderr (INFO level).
1503 *
1504 * @param message Message received.
1505 * @param peer Peer who sent the message.
1506 * @param hash Connection ID.
1507 */
1508static void
1509log_message (const struct GNUNET_MessageHeader *message,
1510 const struct GNUNET_PeerIdentity *peer,
1511 const struct GNUNET_CADET_Hash *hash)
1512{
1513 LOG (GNUNET_ERROR_TYPE_INFO, "<-- %s on connection %s from %s\n",
1514 GM_m2s (ntohs (message->type)), GNUNET_h2s (GM_h2hc (hash)),
1515 GNUNET_i2s (peer));
1516}
1517
1518/******************************************************************************/
1519/******************************** API ***********************************/
1520/******************************************************************************/
1521
1522/**
1523 * Core handler for connection creation.
1524 *
1525 * @param cls Closure (unused).
1526 * @param peer Sender (neighbor).
1527 * @param message Message.
1528 *
1529 * @return GNUNET_OK to keep the connection open,
1530 * GNUNET_SYSERR to close it (signal serious error)
1531 */
1532int
1533GMC_handle_create (void *cls, const struct GNUNET_PeerIdentity *peer,
1534 const struct GNUNET_MessageHeader *message)
1535{
1536 struct GNUNET_CADET_ConnectionCreate *msg;
1537 struct GNUNET_PeerIdentity *id;
1538 struct GNUNET_CADET_Hash *cid;
1539 struct CadetPeerPath *path;
1540 struct CadetPeer *dest_peer;
1541 struct CadetPeer *orig_peer;
1542 struct CadetConnection *c;
1543 unsigned int own_pos;
1544 uint16_t size;
1545
1546 /* Check size */
1547 size = ntohs (message->size);
1548 if (size < sizeof (struct GNUNET_CADET_ConnectionCreate))
1549 {
1550 GNUNET_break_op (0);
1551 return GNUNET_OK;
1552 }
1553
1554 /* Calculate hops */
1555 size -= sizeof (struct GNUNET_CADET_ConnectionCreate);
1556 if (size % sizeof (struct GNUNET_PeerIdentity))
1557 {
1558 GNUNET_break_op (0);
1559 return GNUNET_OK;
1560 }
1561 size /= sizeof (struct GNUNET_PeerIdentity);
1562 if (1 > size)
1563 {
1564 GNUNET_break_op (0);
1565 return GNUNET_OK;
1566 }
1567 LOG (GNUNET_ERROR_TYPE_DEBUG, " path has %u hops.\n", size);
1568
1569 /* Get parameters */
1570 msg = (struct GNUNET_CADET_ConnectionCreate *) message;
1571 cid = &msg->cid;
1572 log_message (message, peer, cid);
1573 id = (struct GNUNET_PeerIdentity *) &msg[1];
1574 LOG (GNUNET_ERROR_TYPE_DEBUG, " origin: %s\n", GNUNET_i2s (id));
1575
1576 /* Create connection */
1577 c = connection_get (cid);
1578 if (NULL == c)
1579 {
1580 path = build_path_from_peer_ids ((struct GNUNET_PeerIdentity *) &msg[1],
1581 size, &own_pos);
1582 if (NULL == path)
1583 return GNUNET_OK;
1584 if (0 == own_pos)
1585 {
1586 GNUNET_break_op (0);
1587 path_destroy (path);
1588 return GNUNET_OK;
1589 }
1590 LOG (GNUNET_ERROR_TYPE_DEBUG, " Own position: %u\n", own_pos);
1591 LOG (GNUNET_ERROR_TYPE_DEBUG, " Creating connection\n");
1592 c = GMC_new (cid, NULL, path_duplicate (path), own_pos);
1593 if (NULL == c)
1594 {
1595 if (path->length - 1 == own_pos)
1596 {
1597 /* If we are destination, why did the creation fail? */
1598 GNUNET_break (0);
1599 return GNUNET_OK;
1600 }
1601 send_broken_unknown (cid, &my_full_id,
1602 GNUNET_PEER_resolve2 (path->peers[own_pos + 1]),
1603 peer);
1604 path_destroy (path);
1605 return GNUNET_OK;
1606 }
1607 GMP_add_path_to_all (path, GNUNET_NO);
1608 connection_reset_timeout (c, GNUNET_YES);
1609 }
1610 else
1611 {
1612 path = path_duplicate (c->path);
1613 }
1614 if (CADET_CONNECTION_NEW == c->state)
1615 connection_change_state (c, CADET_CONNECTION_SENT);
1616
1617 /* Remember peers */
1618 dest_peer = GMP_get (&id[size - 1]);
1619 orig_peer = GMP_get (&id[0]);
1620
1621 /* Is it a connection to us? */
1622 if (c->own_pos == path->length - 1)
1623 {
1624 LOG (GNUNET_ERROR_TYPE_DEBUG, " It's for us!\n");
1625 GMP_add_path_to_origin (orig_peer, path_duplicate (path), GNUNET_YES);
1626
1627 add_to_peer (c, orig_peer);
1628 if (CADET_TUNNEL3_NEW == GMT_get_cstate (c->t))
1629 GMT_change_cstate (c->t, CADET_TUNNEL3_WAITING);
1630
1631 send_connection_ack (c, GNUNET_NO);
1632 if (CADET_CONNECTION_SENT == c->state)
1633 connection_change_state (c, CADET_CONNECTION_ACK);
1634 }
1635 else
1636 {
1637 /* It's for somebody else! Retransmit. */
1638 LOG (GNUNET_ERROR_TYPE_DEBUG, " Retransmitting.\n");
1639 GMP_add_path (dest_peer, path_duplicate (path), GNUNET_NO);
1640 GMP_add_path_to_origin (orig_peer, path_duplicate (path), GNUNET_NO);
1641 GMC_send_prebuilt_message (message,
1642 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE, 0,
1643 c, GNUNET_YES, GNUNET_YES,
1644 NULL, NULL);
1645 }
1646 path_destroy (path);
1647 return GNUNET_OK;
1648}
1649
1650
1651/**
1652 * Core handler for path confirmations.
1653 *
1654 * @param cls closure
1655 * @param message message
1656 * @param peer peer identity this notification is about
1657 *
1658 * @return GNUNET_OK to keep the connection open,
1659 * GNUNET_SYSERR to close it (signal serious error)
1660 */
1661int
1662GMC_handle_confirm (void *cls, const struct GNUNET_PeerIdentity *peer,
1663 const struct GNUNET_MessageHeader *message)
1664{
1665 struct GNUNET_CADET_ConnectionACK *msg;
1666 struct CadetConnection *c;
1667 struct CadetPeerPath *p;
1668 struct CadetPeer *pi;
1669 enum CadetConnectionState oldstate;
1670 int fwd;
1671
1672 msg = (struct GNUNET_CADET_ConnectionACK *) message;
1673 log_message (message, peer, &msg->cid);
1674 c = connection_get (&msg->cid);
1675 if (NULL == c)
1676 {
1677 GNUNET_STATISTICS_update (stats, "# control on unknown connection",
1678 1, GNUNET_NO);
1679 LOG (GNUNET_ERROR_TYPE_DEBUG, " don't know the connection!\n");
1680 send_broken_unknown (&msg->cid, &my_full_id, NULL, peer);
1681 return GNUNET_OK;
1682 }
1683
1684 if (GNUNET_NO != c->destroy)
1685 {
1686 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection being destroyed\n");
1687 return GNUNET_OK;
1688 }
1689
1690 oldstate = c->state;
1691 LOG (GNUNET_ERROR_TYPE_DEBUG, " via peer %s\n", GNUNET_i2s (peer));
1692 pi = GMP_get (peer);
1693 if (get_next_hop (c) == pi)
1694 {
1695 LOG (GNUNET_ERROR_TYPE_DEBUG, " SYNACK\n");
1696 fwd = GNUNET_NO;
1697 if (CADET_CONNECTION_SENT == oldstate)
1698 connection_change_state (c, CADET_CONNECTION_ACK);
1699 }
1700 else if (get_prev_hop (c) == pi)
1701 {
1702 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK\n");
1703 fwd = GNUNET_YES;
1704 connection_change_state (c, CADET_CONNECTION_READY);
1705 }
1706 else
1707 {
1708 GNUNET_break_op (0);
1709 return GNUNET_OK;
1710 }
1711
1712 connection_reset_timeout (c, fwd);
1713
1714 /* Add path to peers? */
1715 p = c->path;
1716 if (NULL != p)
1717 {
1718 GMP_add_path_to_all (p, GNUNET_YES);
1719 }
1720 else
1721 {
1722 GNUNET_break (0);
1723 }
1724
1725 /* Message for us as creator? */
1726 if (GMC_is_origin (c, GNUNET_YES))
1727 {
1728 if (GNUNET_NO != fwd)
1729 {
1730 GNUNET_break_op (0);
1731 return GNUNET_OK;
1732 }
1733 LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection (SYN)ACK for us!\n");
1734
1735 /* If just created, cancel the short timeout and start a long one */
1736 if (CADET_CONNECTION_SENT == oldstate)
1737 connection_reset_timeout (c, GNUNET_YES);
1738
1739 /* Change connection state */
1740 connection_change_state (c, CADET_CONNECTION_READY);
1741 send_connection_ack (c, GNUNET_YES);
1742
1743 /* Change tunnel state, trigger KX */
1744 if (CADET_TUNNEL3_WAITING == GMT_get_cstate (c->t))
1745 GMT_change_cstate (c->t, CADET_TUNNEL3_READY);
1746
1747 return GNUNET_OK;
1748 }
1749
1750 /* Message for us as destination? */
1751 if (GMC_is_terminal (c, GNUNET_YES))
1752 {
1753 if (GNUNET_YES != fwd)
1754 {
1755 GNUNET_break_op (0);
1756 return GNUNET_OK;
1757 }
1758 LOG (GNUNET_ERROR_TYPE_DEBUG, " Connection ACK for us!\n");
1759
1760 /* If just created, cancel the short timeout and start a long one */
1761 if (CADET_CONNECTION_ACK == oldstate)
1762 connection_reset_timeout (c, GNUNET_NO);
1763
1764 /* Change tunnel state */
1765 if (CADET_TUNNEL3_WAITING == GMT_get_cstate (c->t))
1766 GMT_change_cstate (c->t, CADET_TUNNEL3_READY);
1767
1768 return GNUNET_OK;
1769 }
1770
1771 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
1772 GMC_send_prebuilt_message (message,
1773 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_ACK, 0,
1774 c, fwd, GNUNET_YES, NULL, NULL);
1775 return GNUNET_OK;
1776}
1777
1778
1779/**
1780 * Core handler for notifications of broken connections.
1781 *
1782 * @param cls Closure (unused).
1783 * @param id Peer identity of sending neighbor.
1784 * @param message Message.
1785 *
1786 * @return GNUNET_OK to keep the connection open,
1787 * GNUNET_SYSERR to close it (signal serious error)
1788 */
1789int
1790GMC_handle_broken (void* cls,
1791 const struct GNUNET_PeerIdentity* id,
1792 const struct GNUNET_MessageHeader* message)
1793{
1794 struct GNUNET_CADET_ConnectionBroken *msg;
1795 struct CadetConnection *c;
1796 int fwd;
1797
1798 msg = (struct GNUNET_CADET_ConnectionBroken *) message;
1799 log_message (message, id, &msg->cid);
1800 LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n",
1801 GNUNET_i2s (&msg->peer1));
1802 LOG (GNUNET_ERROR_TYPE_DEBUG, " regarding %s\n",
1803 GNUNET_i2s (&msg->peer2));
1804 c = connection_get (&msg->cid);
1805 if (NULL == c)
1806 {
1807 LOG (GNUNET_ERROR_TYPE_DEBUG, " duplicate CONNECTION_BROKEN\n");
1808 return GNUNET_OK;
1809 }
1810
1811 fwd = is_fwd (c, id);
1812 if (GMC_is_terminal (c, fwd))
1813 {
1814 struct GNUNET_MessageHeader *out_msg;
1815 struct CadetPeer *neighbor;
1816 struct CadetPeer *endpoint;
1817
1818 neighbor = get_hop (c, !fwd);
1819 endpoint = GMP_get_short (c->path->peers[c->path->length - 1]);
1820 path_invalidate (c->path);
1821 GMP_notify_broken_link (endpoint, &msg->peer1, &msg->peer2);
1822 c->state = CADET_CONNECTION_DESTROYED;
1823 while (NULL != (out_msg = GMP_connection_pop (neighbor, c)))
1824 {
1825 GNUNET_assert (NULL ==
1826 GMT_send_prebuilt_message (out_msg, c->t, NULL, GNUNET_YES,
1827 NULL, NULL));
1828 }
1829
1830 GMC_destroy (c);
1831 }
1832 else
1833 {
1834 GMC_send_prebuilt_message (message,
1835 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN, 0,
1836 c, fwd, GNUNET_YES, NULL, NULL);
1837 c->destroy = GNUNET_YES;
1838 connection_cancel_queues (c, !fwd);
1839 }
1840
1841 return GNUNET_OK;
1842
1843}
1844
1845
1846/**
1847 * Core handler for tunnel destruction
1848 *
1849 * @param cls Closure (unused).
1850 * @param peer Peer identity of sending neighbor.
1851 * @param message Message.
1852 *
1853 * @return GNUNET_OK to keep the connection open,
1854 * GNUNET_SYSERR to close it (signal serious error)
1855 */
1856int
1857GMC_handle_destroy (void *cls, const struct GNUNET_PeerIdentity *peer,
1858 const struct GNUNET_MessageHeader *message)
1859{
1860 struct GNUNET_CADET_ConnectionDestroy *msg;
1861 struct CadetConnection *c;
1862 int fwd;
1863
1864 msg = (struct GNUNET_CADET_ConnectionDestroy *) message;
1865 log_message (message, peer, &msg->cid);
1866 c = connection_get (&msg->cid);
1867 if (NULL == c)
1868 {
1869 /* Probably already got the message from another path,
1870 * destroyed the tunnel and retransmitted to children.
1871 * Safe to ignore.
1872 */
1873 GNUNET_STATISTICS_update (stats, "# control on unknown connection",
1874 1, GNUNET_NO);
1875 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection unknown: already destroyed?\n");
1876 return GNUNET_OK;
1877 }
1878 fwd = is_fwd (c, peer);
1879 if (GNUNET_SYSERR == fwd)
1880 {
1881 GNUNET_break_op (0); /* FIXME */
1882 return GNUNET_OK;
1883 }
1884 if (GNUNET_NO == GMC_is_terminal (c, fwd))
1885 GMC_send_prebuilt_message (message,
1886 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY, 0,
1887 c, fwd, GNUNET_YES, NULL, NULL);
1888 else if (0 == c->pending_messages)
1889 {
1890 LOG (GNUNET_ERROR_TYPE_DEBUG, " directly destroying connection!\n");
1891 GMC_destroy (c);
1892 return GNUNET_OK;
1893 }
1894 c->destroy = GNUNET_YES;
1895 c->state = CADET_CONNECTION_DESTROYED;
1896 if (NULL != c->t)
1897 {
1898 GMT_remove_connection (c->t, c);
1899 c->t = NULL;
1900 }
1901
1902 return GNUNET_OK;
1903}
1904
1905/**
1906 * Generic handler for cadet network encrypted traffic.
1907 *
1908 * @param peer Peer identity this notification is about.
1909 * @param msg Encrypted message.
1910 *
1911 * @return GNUNET_OK to keep the connection open,
1912 * GNUNET_SYSERR to close it (signal serious error)
1913 */
1914static int
1915handle_cadet_encrypted (const struct GNUNET_PeerIdentity *peer,
1916 const struct GNUNET_CADET_Encrypted *msg)
1917{
1918 struct CadetConnection *c;
1919 struct CadetPeer *neighbor;
1920 struct CadetFlowControl *fc;
1921 GNUNET_PEER_Id peer_id;
1922 uint32_t pid;
1923 uint32_t ttl;
1924 size_t size;
1925 int fwd;
1926
1927 log_message (&msg->header, peer, &msg->cid);
1928
1929 /* Check size */
1930 size = ntohs (msg->header.size);
1931 if (size <
1932 sizeof (struct GNUNET_CADET_Encrypted) +
1933 sizeof (struct GNUNET_MessageHeader))
1934 {
1935 GNUNET_break_op (0);
1936 return GNUNET_OK;
1937 }
1938
1939 /* Check connection */
1940 c = connection_get (&msg->cid);
1941 if (NULL == c)
1942 {
1943 GNUNET_STATISTICS_update (stats, "# unknown connection", 1, GNUNET_NO);
1944 LOG (GNUNET_ERROR_TYPE_DEBUG, "enc on unknown connection %s\n",
1945 GNUNET_h2s (GM_h2hc (&msg->cid)));
1946 send_broken_unknown (&msg->cid, &my_full_id, NULL, peer);
1947 return GNUNET_OK;
1948 }
1949
1950 LOG (GNUNET_ERROR_TYPE_DEBUG, " connection %s\n", GMC_2s (c));
1951
1952 /* Check if origin is as expected */
1953 neighbor = get_prev_hop (c);
1954 peer_id = GNUNET_PEER_search (peer);
1955 if (peer_id == GMP_get_short_id (neighbor))
1956 {
1957 fwd = GNUNET_YES;
1958 }
1959 else
1960 {
1961 neighbor = get_next_hop (c);
1962 if (peer_id == GMP_get_short_id (neighbor))
1963 {
1964 fwd = GNUNET_NO;
1965 }
1966 else
1967 {
1968 /* Unexpected peer sending traffic on a connection. */
1969 GNUNET_break_op (0);
1970 return GNUNET_OK;
1971 }
1972 }
1973
1974 /* Check PID */
1975 fc = fwd ? &c->bck_fc : &c->fwd_fc;
1976 pid = ntohl (msg->pid);
1977 LOG (GNUNET_ERROR_TYPE_DEBUG, " PID %u (expected %u+)\n",
1978 pid, fc->last_pid_recv + 1);
1979 if (GM_is_pid_bigger (pid, fc->last_ack_sent))
1980 {
1981 GNUNET_STATISTICS_update (stats, "# unsolicited message", 1, GNUNET_NO);
1982 GNUNET_break_op (0);
1983 LOG (GNUNET_ERROR_TYPE_WARNING,
1984 "Received PID %u, (prev %u), ACK %u\n",
1985 pid, fc->last_pid_recv, fc->last_ack_sent);
1986 return GNUNET_OK;
1987 }
1988 if (GNUNET_NO == GM_is_pid_bigger (pid, fc->last_pid_recv))
1989 {
1990 GNUNET_STATISTICS_update (stats, "# duplicate PID", 1, GNUNET_NO);
1991 LOG (GNUNET_ERROR_TYPE_DEBUG,
1992 " PID %u not expected (%u+), dropping!\n",
1993 pid, fc->last_pid_recv + 1);
1994 return GNUNET_OK;
1995 }
1996 if (CADET_CONNECTION_SENT == c->state || CADET_CONNECTION_ACK == c->state)
1997 connection_change_state (c, CADET_CONNECTION_READY);
1998 connection_reset_timeout (c, fwd);
1999 fc->last_pid_recv = pid;
2000
2001 /* Is this message for us? */
2002 if (GMC_is_terminal (c, fwd))
2003 {
2004 LOG (GNUNET_ERROR_TYPE_DEBUG, " message for us!\n");
2005 GNUNET_STATISTICS_update (stats, "# messages received", 1, GNUNET_NO);
2006
2007 if (NULL == c->t)
2008 {
2009 GNUNET_break (GNUNET_NO != c->destroy);
2010 return GNUNET_OK;
2011 }
2012 fc->last_pid_recv = pid;
2013 GMT_handle_encrypted (c->t, msg);
2014 GMC_send_ack (c, fwd, GNUNET_NO);
2015 return GNUNET_OK;
2016 }
2017
2018 /* Message not for us: forward to next hop */
2019 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
2020 ttl = ntohl (msg->ttl);
2021 LOG (GNUNET_ERROR_TYPE_DEBUG, " ttl: %u\n", ttl);
2022 if (ttl == 0)
2023 {
2024 GNUNET_STATISTICS_update (stats, "# TTL drops", 1, GNUNET_NO);
2025 LOG (GNUNET_ERROR_TYPE_WARNING, " TTL is 0, DROPPING!\n");
2026 GMC_send_ack (c, fwd, GNUNET_NO);
2027 return GNUNET_OK;
2028 }
2029
2030 GNUNET_STATISTICS_update (stats, "# messages forwarded", 1, GNUNET_NO);
2031 GMC_send_prebuilt_message (&msg->header,
2032 GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED, 0,
2033 c, fwd, GNUNET_NO, NULL, NULL);
2034
2035 return GNUNET_OK;
2036}
2037
2038/**
2039 * Generic handler for cadet network encrypted traffic.
2040 *
2041 * @param peer Peer identity this notification is about.
2042 * @param msg Encrypted message.
2043 *
2044 * @return GNUNET_OK to keep the connection open,
2045 * GNUNET_SYSERR to close it (signal serious error)
2046 */
2047static int
2048handle_cadet_kx (const struct GNUNET_PeerIdentity *peer,
2049 const struct GNUNET_CADET_KX *msg)
2050{
2051 struct CadetConnection *c;
2052 struct CadetPeer *neighbor;
2053 GNUNET_PEER_Id peer_id;
2054 size_t size;
2055 int fwd;
2056
2057 log_message (&msg->header, peer, &msg->cid);
2058
2059 /* Check size */
2060 size = ntohs (msg->header.size);
2061 if (size <
2062 sizeof (struct GNUNET_CADET_KX) +
2063 sizeof (struct GNUNET_MessageHeader))
2064 {
2065 GNUNET_break_op (0);
2066 return GNUNET_OK;
2067 }
2068
2069 /* Check connection */
2070 c = connection_get (&msg->cid);
2071 if (NULL == c)
2072 {
2073 GNUNET_STATISTICS_update (stats, "# unknown connection", 1, GNUNET_NO);
2074 LOG (GNUNET_ERROR_TYPE_DEBUG, "kx on unknown connection %s\n",
2075 GNUNET_h2s (GM_h2hc (&msg->cid)));
2076 send_broken_unknown (&msg->cid, &my_full_id, NULL, peer);
2077 return GNUNET_OK;
2078 }
2079 LOG (GNUNET_ERROR_TYPE_DEBUG, " on connection %s\n", GMC_2s (c));
2080
2081 /* Check if origin is as expected */
2082 neighbor = get_prev_hop (c);
2083 peer_id = GNUNET_PEER_search (peer);
2084 if (peer_id == GMP_get_short_id (neighbor))
2085 {
2086 fwd = GNUNET_YES;
2087 }
2088 else
2089 {
2090 neighbor = get_next_hop (c);
2091 if (peer_id == GMP_get_short_id (neighbor))
2092 {
2093 fwd = GNUNET_NO;
2094 }
2095 else
2096 {
2097 /* Unexpected peer sending traffic on a connection. */
2098 GNUNET_break_op (0);
2099 return GNUNET_OK;
2100 }
2101 }
2102
2103 /* Count as connection confirmation. */
2104 if (CADET_CONNECTION_SENT == c->state || CADET_CONNECTION_ACK == c->state)
2105 {
2106 connection_change_state (c, CADET_CONNECTION_READY);
2107 if (NULL != c->t)
2108 {
2109 if (CADET_TUNNEL3_WAITING == GMT_get_cstate (c->t))
2110 GMT_change_cstate (c->t, CADET_TUNNEL3_READY);
2111 }
2112 }
2113 connection_reset_timeout (c, fwd);
2114
2115 /* Is this message for us? */
2116 if (GMC_is_terminal (c, fwd))
2117 {
2118 LOG (GNUNET_ERROR_TYPE_DEBUG, " message for us!\n");
2119 GNUNET_STATISTICS_update (stats, "# messages received", 1, GNUNET_NO);
2120 if (NULL == c->t)
2121 {
2122 GNUNET_break (0);
2123 return GNUNET_OK;
2124 }
2125 GMT_handle_kx (c->t, &msg[1].header);
2126 return GNUNET_OK;
2127 }
2128
2129 /* Message not for us: forward to next hop */
2130 LOG (GNUNET_ERROR_TYPE_DEBUG, " not for us, retransmitting...\n");
2131 GNUNET_STATISTICS_update (stats, "# messages forwarded", 1, GNUNET_NO);
2132 GMC_send_prebuilt_message (&msg->header, GNUNET_MESSAGE_TYPE_CADET_KX, 0,
2133 c, fwd, GNUNET_NO, NULL, NULL);
2134
2135 return GNUNET_OK;
2136}
2137
2138
2139/**
2140 * Core handler for encrypted cadet network traffic (channel mgmt, data).
2141 *
2142 * @param cls Closure (unused).
2143 * @param message Message received.
2144 * @param peer Peer who sent the message.
2145 *
2146 * @return GNUNET_OK to keep the connection open,
2147 * GNUNET_SYSERR to close it (signal serious error)
2148 */
2149int
2150GMC_handle_encrypted (void *cls, const struct GNUNET_PeerIdentity *peer,
2151 const struct GNUNET_MessageHeader *message)
2152{
2153 return handle_cadet_encrypted (peer,
2154 (struct GNUNET_CADET_Encrypted *)message);
2155}
2156
2157
2158/**
2159 * Core handler for key exchange traffic (ephemeral key, ping, pong).
2160 *
2161 * @param cls Closure (unused).
2162 * @param message Message received.
2163 * @param peer Peer who sent the message.
2164 *
2165 * @return GNUNET_OK to keep the connection open,
2166 * GNUNET_SYSERR to close it (signal serious error)
2167 */
2168int
2169GMC_handle_kx (void *cls, const struct GNUNET_PeerIdentity *peer,
2170 const struct GNUNET_MessageHeader *message)
2171{
2172 return handle_cadet_kx (peer,
2173 (struct GNUNET_CADET_KX *) message);
2174}
2175
2176
2177/**
2178 * Core handler for cadet network traffic point-to-point acks.
2179 *
2180 * @param cls closure
2181 * @param message message
2182 * @param peer peer identity this notification is about
2183 *
2184 * @return GNUNET_OK to keep the connection open,
2185 * GNUNET_SYSERR to close it (signal serious error)
2186 */
2187int
2188GMC_handle_ack (void *cls, const struct GNUNET_PeerIdentity *peer,
2189 const struct GNUNET_MessageHeader *message)
2190{
2191 struct GNUNET_CADET_ACK *msg;
2192 struct CadetConnection *c;
2193 struct CadetFlowControl *fc;
2194 GNUNET_PEER_Id id;
2195 uint32_t ack;
2196 int fwd;
2197
2198 msg = (struct GNUNET_CADET_ACK *) message;
2199 log_message (message, peer, &msg->cid);
2200 c = connection_get (&msg->cid);
2201 if (NULL == c)
2202 {
2203 GNUNET_STATISTICS_update (stats, "# ack on unknown connection", 1,
2204 GNUNET_NO);
2205 send_broken_unknown (&msg->cid, &my_full_id, NULL, peer);
2206 return GNUNET_OK;
2207 }
2208
2209 /* Is this a forward or backward ACK? */
2210 id = GNUNET_PEER_search (peer);
2211 if (GMP_get_short_id (get_next_hop (c)) == id)
2212 {
2213 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD ACK\n");
2214 fc = &c->fwd_fc;
2215 fwd = GNUNET_YES;
2216 }
2217 else if (GMP_get_short_id (get_prev_hop (c)) == id)
2218 {
2219 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK ACK\n");
2220 fc = &c->bck_fc;
2221 fwd = GNUNET_NO;
2222 }
2223 else
2224 {
2225 GNUNET_break_op (0);
2226 return GNUNET_OK;
2227 }
2228
2229 ack = ntohl (msg->ack);
2230 LOG (GNUNET_ERROR_TYPE_DEBUG, " ACK %u (was %u)\n",
2231 ack, fc->last_ack_recv);
2232 if (GM_is_pid_bigger (ack, fc->last_ack_recv))
2233 fc->last_ack_recv = ack;
2234
2235 /* Cancel polling if the ACK is big enough. */
2236 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task &&
2237 GM_is_pid_bigger (fc->last_ack_recv, fc->last_pid_sent))
2238 {
2239 LOG (GNUNET_ERROR_TYPE_DEBUG, " Cancel poll\n");
2240 GNUNET_SCHEDULER_cancel (fc->poll_task);
2241 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
2242 fc->poll_time = GNUNET_TIME_UNIT_SECONDS;
2243 }
2244
2245 connection_unlock_queue (c, fwd);
2246
2247 return GNUNET_OK;
2248}
2249
2250
2251/**
2252 * Core handler for cadet network traffic point-to-point ack polls.
2253 *
2254 * @param cls closure
2255 * @param message message
2256 * @param peer peer identity this notification is about
2257 *
2258 * @return GNUNET_OK to keep the connection open,
2259 * GNUNET_SYSERR to close it (signal serious error)
2260 */
2261int
2262GMC_handle_poll (void *cls, const struct GNUNET_PeerIdentity *peer,
2263 const struct GNUNET_MessageHeader *message)
2264{
2265 struct GNUNET_CADET_Poll *msg;
2266 struct CadetConnection *c;
2267 struct CadetFlowControl *fc;
2268 GNUNET_PEER_Id id;
2269 uint32_t pid;
2270 int fwd;
2271
2272 msg = (struct GNUNET_CADET_Poll *) message;
2273 log_message (message, peer, &msg->cid);
2274 c = connection_get (&msg->cid);
2275 if (NULL == c)
2276 {
2277 GNUNET_STATISTICS_update (stats, "# poll on unknown connection", 1,
2278 GNUNET_NO);
2279 LOG (GNUNET_ERROR_TYPE_DEBUG, "POLL message on unknown connection %s!\n",
2280 GNUNET_h2s (GM_h2hc (&msg->cid)));
2281 send_broken_unknown (&msg->cid, &my_full_id, NULL, peer);
2282 return GNUNET_OK;
2283 }
2284
2285 /* Is this a forward or backward ACK?
2286 * Note: a poll should never be needed in a loopback case,
2287 * since there is no possiblility of packet loss there, so
2288 * this way of discerining FWD/BCK should not be a problem.
2289 */
2290 id = GNUNET_PEER_search (peer);
2291 if (GMP_get_short_id (get_next_hop (c)) == id)
2292 {
2293 LOG (GNUNET_ERROR_TYPE_DEBUG, " FWD FC\n");
2294 fc = &c->fwd_fc;
2295 }
2296 else if (GMP_get_short_id (get_prev_hop (c)) == id)
2297 {
2298 LOG (GNUNET_ERROR_TYPE_DEBUG, " BCK FC\n");
2299 fc = &c->bck_fc;
2300 }
2301 else
2302 {
2303 GNUNET_break_op (0);
2304 return GNUNET_OK;
2305 }
2306
2307 pid = ntohl (msg->pid);
2308 LOG (GNUNET_ERROR_TYPE_DEBUG, " PID %u, OLD %u\n", pid, fc->last_pid_recv);
2309 fc->last_pid_recv = pid;
2310 fwd = fc == &c->bck_fc;
2311 GMC_send_ack (c, fwd, GNUNET_YES);
2312
2313 return GNUNET_OK;
2314}
2315
2316
2317/**
2318 * Send an ACK on the appropriate connection/channel, depending on
2319 * the direction and the position of the peer.
2320 *
2321 * @param c Which connection to send the hop-by-hop ACK.
2322 * @param fwd Is this a fwd ACK? (will go dest->root).
2323 * @param force Send the ACK even if suboptimal (e.g. requested by POLL).
2324 */
2325void
2326GMC_send_ack (struct CadetConnection *c, int fwd, int force)
2327{
2328 unsigned int buffer;
2329
2330 LOG (GNUNET_ERROR_TYPE_DEBUG,
2331 "GMC send %s ACK on %s\n",
2332 GM_f2s (fwd), GMC_2s (c));
2333
2334 if (NULL == c)
2335 {
2336 GNUNET_break (0);
2337 return;
2338 }
2339
2340 if (GNUNET_NO != c->destroy)
2341 {
2342 LOG (GNUNET_ERROR_TYPE_DEBUG, " being destroyed, why bother...\n");
2343 return;
2344 }
2345
2346 /* Get available buffer space */
2347 if (GMC_is_terminal (c, fwd))
2348 {
2349 LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from all channels\n");
2350 buffer = GMT_get_channels_buffer (c->t);
2351 }
2352 else
2353 {
2354 LOG (GNUNET_ERROR_TYPE_DEBUG, " getting from one connection\n");
2355 buffer = GMC_get_buffer (c, fwd);
2356 }
2357 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer available: %u\n", buffer);
2358 if (0 == buffer && GNUNET_NO == force)
2359 return;
2360
2361 /* Send available buffer space */
2362 if (GMC_is_origin (c, fwd))
2363 {
2364 GNUNET_assert (NULL != c->t);
2365 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channels...\n");
2366 GMT_unchoke_channels (c->t);
2367 }
2368 else
2369 {
2370 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on connection\n");
2371 send_ack (c, buffer, fwd, force);
2372 }
2373}
2374
2375
2376/**
2377 * Initialize the connections subsystem
2378 *
2379 * @param c Configuration handle.
2380 */
2381void
2382GMC_init (const struct GNUNET_CONFIGURATION_Handle *c)
2383{
2384 LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
2385 if (GNUNET_OK !=
2386 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "MAX_MSGS_QUEUE",
2387 &max_msgs_queue))
2388 {
2389 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
2390 "CADET", "MAX_MSGS_QUEUE", "MISSING");
2391 GNUNET_SCHEDULER_shutdown ();
2392 return;
2393 }
2394
2395 if (GNUNET_OK !=
2396 GNUNET_CONFIGURATION_get_value_number (c, "CADET", "MAX_CONNECTIONS",
2397 &max_connections))
2398 {
2399 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
2400 "CADET", "MAX_CONNECTIONS", "MISSING");
2401 GNUNET_SCHEDULER_shutdown ();
2402 return;
2403 }
2404
2405 if (GNUNET_OK !=
2406 GNUNET_CONFIGURATION_get_value_time (c, "CADET", "REFRESH_CONNECTION_TIME",
2407 &refresh_connection_time))
2408 {
2409 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
2410 "CADET", "REFRESH_CONNECTION_TIME", "MISSING");
2411 GNUNET_SCHEDULER_shutdown ();
2412 return;
2413 }
2414 create_connection_time = GNUNET_TIME_UNIT_SECONDS;
2415 connections = GNUNET_CONTAINER_multihashmap_create (1024, GNUNET_NO);
2416}
2417
2418
2419/**
2420 * Destroy each connection on shutdown.
2421 *
2422 * @param cls Closure (unused).
2423 * @param key Current key code (CID, unused).
2424 * @param value Value in the hash map (connection)
2425 *
2426 * @return #GNUNET_YES, because we should continue to iterate,
2427 */
2428static int
2429shutdown_iterator (void *cls,
2430 const struct GNUNET_HashCode *key,
2431 void *value)
2432{
2433 struct CadetConnection *c = value;
2434
2435 GMC_destroy (c);
2436 return GNUNET_YES;
2437}
2438
2439
2440/**
2441 * Shut down the connections subsystem.
2442 */
2443void
2444GMC_shutdown (void)
2445{
2446 GNUNET_CONTAINER_multihashmap_iterate (connections, &shutdown_iterator, NULL);
2447 GNUNET_CONTAINER_multihashmap_destroy (connections);
2448 connections = NULL;
2449}
2450
2451
2452struct CadetConnection *
2453GMC_new (const struct GNUNET_CADET_Hash *cid,
2454 struct CadetTunnel3 *t,
2455 struct CadetPeerPath *p,
2456 unsigned int own_pos)
2457{
2458 struct CadetConnection *c;
2459
2460 c = GNUNET_new (struct CadetConnection);
2461 c->id = *cid;
2462 GNUNET_assert (GNUNET_OK ==
2463 GNUNET_CONTAINER_multihashmap_put (connections,
2464 GMC_get_h (c), c,
2465 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
2466 fc_init (&c->fwd_fc);
2467 fc_init (&c->bck_fc);
2468 c->fwd_fc.c = c;
2469 c->bck_fc.c = c;
2470
2471 c->t = t;
2472 GNUNET_assert (own_pos <= p->length - 1);
2473 c->own_pos = own_pos;
2474 c->path = p;
2475 p->c = c;
2476
2477 if (GNUNET_OK != register_neighbors (c))
2478 {
2479 if (0 == own_pos)
2480 {
2481 path_invalidate (c->path);
2482 c->t = NULL;
2483 c->path = NULL;
2484 }
2485 GMC_destroy (c);
2486 return NULL;
2487 }
2488
2489 return c;
2490}
2491
2492
2493void
2494GMC_destroy (struct CadetConnection *c)
2495{
2496 if (NULL == c)
2497 {
2498 GNUNET_break (0);
2499 return;
2500 }
2501
2502 if (2 == c->destroy) /* cancel queues -> GMP_queue_cancel -> q_destroy -> */
2503 return; /* -> message_sent -> GMC_destroy. Don't loop. */
2504 c->destroy = 2;
2505
2506 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying connection %s\n", GMC_2s (c));
2507 LOG (GNUNET_ERROR_TYPE_DEBUG, " fc's f: %p, b: %p\n",
2508 &c->fwd_fc, &c->bck_fc);
2509 LOG (GNUNET_ERROR_TYPE_DEBUG, " fc tasks f: %u, b: %u\n",
2510 c->fwd_fc.poll_task, c->bck_fc.poll_task);
2511
2512 /* Cancel all traffic */
2513 if (NULL != c->path)
2514 {
2515 connection_cancel_queues (c, GNUNET_YES);
2516 connection_cancel_queues (c, GNUNET_NO);
2517 unregister_neighbors (c);
2518 }
2519
2520 LOG (GNUNET_ERROR_TYPE_DEBUG, " fc tasks f: %u, b: %u\n",
2521 c->fwd_fc.poll_task, c->bck_fc.poll_task);
2522
2523 /* Cancel maintainance task (keepalive/timeout) */
2524 if (NULL != c->fwd_fc.poll_msg)
2525 {
2526 GMC_cancel (c->fwd_fc.poll_msg);
2527 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL msg FWD canceled\n");
2528 }
2529 if (NULL != c->bck_fc.poll_msg)
2530 {
2531 GMC_cancel (c->bck_fc.poll_msg);
2532 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL msg BCK canceled\n");
2533 }
2534
2535 /* Delete from tunnel */
2536 if (NULL != c->t)
2537 GMT_remove_connection (c->t, c);
2538
2539 if (GNUNET_NO == GMC_is_origin (c, GNUNET_YES) && NULL != c->path)
2540 path_destroy (c->path);
2541 if (GNUNET_SCHEDULER_NO_TASK != c->fwd_maintenance_task)
2542 GNUNET_SCHEDULER_cancel (c->fwd_maintenance_task);
2543 if (GNUNET_SCHEDULER_NO_TASK != c->bck_maintenance_task)
2544 GNUNET_SCHEDULER_cancel (c->bck_maintenance_task);
2545 if (GNUNET_SCHEDULER_NO_TASK != c->fwd_fc.poll_task)
2546 {
2547 GNUNET_SCHEDULER_cancel (c->fwd_fc.poll_task);
2548 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL FWD canceled\n");
2549 }
2550 if (GNUNET_SCHEDULER_NO_TASK != c->bck_fc.poll_task)
2551 {
2552 GNUNET_SCHEDULER_cancel (c->bck_fc.poll_task);
2553 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL BCK canceled\n");
2554 }
2555
2556 GNUNET_break (GNUNET_YES ==
2557 GNUNET_CONTAINER_multihashmap_remove (connections,
2558 GMC_get_h (c), c));
2559
2560 GNUNET_STATISTICS_update (stats, "# connections", -1, GNUNET_NO);
2561 GNUNET_free (c);
2562}
2563
2564/**
2565 * Get the connection ID.
2566 *
2567 * @param c Connection to get the ID from.
2568 *
2569 * @return ID of the connection.
2570 */
2571const struct GNUNET_CADET_Hash *
2572GMC_get_id (const struct CadetConnection *c)
2573{
2574 return &c->id;
2575}
2576
2577
2578/**
2579 * Get the connection ID.
2580 *
2581 * @param c Connection to get the ID from.
2582 *
2583 * @return ID of the connection.
2584 */
2585const struct GNUNET_HashCode *
2586GMC_get_h (const struct CadetConnection *c)
2587{
2588 return GM_h2hc (&c->id);
2589}
2590
2591
2592/**
2593 * Get the connection path.
2594 *
2595 * @param c Connection to get the path from.
2596 *
2597 * @return path used by the connection.
2598 */
2599const struct CadetPeerPath *
2600GMC_get_path (const struct CadetConnection *c)
2601{
2602 if (GNUNET_NO == c->destroy)
2603 return c->path;
2604 return NULL;
2605}
2606
2607
2608/**
2609 * Get the connection state.
2610 *
2611 * @param c Connection to get the state from.
2612 *
2613 * @return state of the connection.
2614 */
2615enum CadetConnectionState
2616GMC_get_state (const struct CadetConnection *c)
2617{
2618 return c->state;
2619}
2620
2621/**
2622 * Get the connection tunnel.
2623 *
2624 * @param c Connection to get the tunnel from.
2625 *
2626 * @return tunnel of the connection.
2627 */
2628struct CadetTunnel3 *
2629GMC_get_tunnel (const struct CadetConnection *c)
2630{
2631 return c->t;
2632}
2633
2634
2635/**
2636 * Get free buffer space in a connection.
2637 *
2638 * @param c Connection.
2639 * @param fwd Is query about FWD traffic?
2640 *
2641 * @return Free buffer space [0 - max_msgs_queue/max_connections]
2642 */
2643unsigned int
2644GMC_get_buffer (struct CadetConnection *c, int fwd)
2645{
2646 struct CadetFlowControl *fc;
2647
2648 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2649
2650 return (fc->queue_max - fc->queue_n);
2651}
2652
2653/**
2654 * Get how many messages have we allowed to send to us from a direction.
2655 *
2656 * @param c Connection.
2657 * @param fwd Are we asking about traffic from FWD (BCK messages)?
2658 *
2659 * @return last_ack_sent - last_pid_recv
2660 */
2661unsigned int
2662GMC_get_allowed (struct CadetConnection *c, int fwd)
2663{
2664 struct CadetFlowControl *fc;
2665
2666 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2667 if (GM_is_pid_bigger(fc->last_pid_recv, fc->last_ack_sent))
2668 {
2669 return 0;
2670 }
2671 return (fc->last_ack_sent - fc->last_pid_recv);
2672}
2673
2674/**
2675 * Get messages queued in a connection.
2676 *
2677 * @param c Connection.
2678 * @param fwd Is query about FWD traffic?
2679 *
2680 * @return Number of messages queued.
2681 */
2682unsigned int
2683GMC_get_qn (struct CadetConnection *c, int fwd)
2684{
2685 struct CadetFlowControl *fc;
2686
2687 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2688
2689 return fc->queue_n;
2690}
2691
2692
2693/**
2694 * Get next PID to use.
2695 *
2696 * @param c Connection.
2697 * @param fwd Is query about FWD traffic?
2698 *
2699 * @return Last PID used + 1.
2700 */
2701unsigned int
2702GMC_get_pid (struct CadetConnection *c, int fwd)
2703{
2704 struct CadetFlowControl *fc;
2705
2706 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2707
2708 return fc->last_pid_sent + 1;
2709}
2710
2711
2712/**
2713 * Allow the connection to advertise a buffer of the given size.
2714 *
2715 * The connection will send an @c fwd ACK message (so: in direction !fwd)
2716 * allowing up to last_pid_recv + buffer.
2717 *
2718 * @param c Connection.
2719 * @param buffer How many more messages the connection can accept.
2720 * @param fwd Is this about FWD traffic? (The ack will go dest->root).
2721 */
2722void
2723GMC_allow (struct CadetConnection *c, unsigned int buffer, int fwd)
2724{
2725 LOG (GNUNET_ERROR_TYPE_DEBUG, " allowing %s %u messages %s\n",
2726 GMC_2s (c), buffer, GM_f2s (fwd));
2727 send_ack (c, buffer, fwd, GNUNET_NO);
2728}
2729
2730
2731/**
2732 * Notify other peers on a connection of a broken link. Mark connections
2733 * to destroy after all traffic has been sent.
2734 *
2735 * @param c Connection on which there has been a disconnection.
2736 * @param peer Peer that disconnected.
2737 */
2738void
2739GMC_notify_broken (struct CadetConnection *c,
2740 struct CadetPeer *peer)
2741{
2742 int fwd;
2743
2744 LOG (GNUNET_ERROR_TYPE_DEBUG,
2745 " notify broken on %s due to %s disconnect\n",
2746 GMC_2s (c), GMP_2s (peer));
2747
2748 fwd = peer == get_prev_hop (c);
2749
2750 if (GNUNET_YES == GMC_is_terminal (c, fwd))
2751 {
2752 /* Local shutdown, no one to notify about this. */
2753 GMC_destroy (c);
2754 return;
2755 }
2756 if (GNUNET_NO == c->destroy)
2757 send_broken (c, &my_full_id, GMP_get_id (peer), fwd);
2758
2759 /* Connection will have at least one pending message
2760 * (the one we just scheduled), so no point in checking whether to
2761 * destroy immediately. */
2762 c->destroy = GNUNET_YES;
2763 c->state = CADET_CONNECTION_DESTROYED;
2764
2765 /**
2766 * Cancel all queues, if no message is left, connection will be destroyed.
2767 */
2768 connection_cancel_queues (c, !fwd);
2769
2770 return;
2771}
2772
2773
2774/**
2775 * Is this peer the first one on the connection?
2776 *
2777 * @param c Connection.
2778 * @param fwd Is this about fwd traffic?
2779 *
2780 * @return #GNUNET_YES if origin, #GNUNET_NO if relay/terminal.
2781 */
2782int
2783GMC_is_origin (struct CadetConnection *c, int fwd)
2784{
2785 if (!fwd && c->path->length - 1 == c->own_pos )
2786 return GNUNET_YES;
2787 if (fwd && 0 == c->own_pos)
2788 return GNUNET_YES;
2789 return GNUNET_NO;
2790}
2791
2792
2793/**
2794 * Is this peer the last one on the connection?
2795 *
2796 * @param c Connection.
2797 * @param fwd Is this about fwd traffic?
2798 * Note that the ROOT is the terminal for BCK traffic!
2799 *
2800 * @return #GNUNET_YES if terminal, #GNUNET_NO if relay/origin.
2801 */
2802int
2803GMC_is_terminal (struct CadetConnection *c, int fwd)
2804{
2805 return GMC_is_origin (c, !fwd);
2806}
2807
2808
2809/**
2810 * See if we are allowed to send by the next hop in the given direction.
2811 *
2812 * @param c Connection.
2813 * @param fwd Is this about fwd traffic?
2814 *
2815 * @return #GNUNET_YES in case it's OK to send.
2816 */
2817int
2818GMC_is_sendable (struct CadetConnection *c, int fwd)
2819{
2820 struct CadetFlowControl *fc;
2821
2822 LOG (GNUNET_ERROR_TYPE_DEBUG, " checking sendability of %s traffic on %s\n",
2823 GM_f2s (fwd), GMC_2s (c));
2824 if (NULL == c)
2825 {
2826 GNUNET_break (0);
2827 return GNUNET_YES;
2828 }
2829 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2830 LOG (GNUNET_ERROR_TYPE_DEBUG,
2831 " last ack recv: %u, last pid sent: %u\n",
2832 fc->last_ack_recv, fc->last_pid_sent);
2833 if (GM_is_pid_bigger (fc->last_ack_recv, fc->last_pid_sent))
2834 {
2835 LOG (GNUNET_ERROR_TYPE_DEBUG, " sendable\n");
2836 return GNUNET_YES;
2837 }
2838 LOG (GNUNET_ERROR_TYPE_DEBUG, " not sendable\n");
2839 return GNUNET_NO;
2840}
2841
2842
2843/**
2844 * Check if this connection is a direct one (never trim a direct connection).
2845 *
2846 * @param c Connection.
2847 *
2848 * @return #GNUNET_YES in case it's a direct connection, #GNUNET_NO otherwise.
2849 */
2850int
2851GMC_is_direct (struct CadetConnection *c)
2852{
2853 return (c->path->length == 2) ? GNUNET_YES : GNUNET_NO;
2854}
2855
2856/**
2857 * Sends an already built message on a connection, properly registering
2858 * all used resources.
2859 *
2860 * @param message Message to send. Function makes a copy of it.
2861 * If message is not hop-by-hop, decrements TTL of copy.
2862 * @param payload_type Type of payload, in case the message is encrypted.
2863 * @param c Connection on which this message is transmitted.
2864 * @param fwd Is this a fwd message?
2865 * @param force Force the connection to accept the message (buffer overfill).
2866 * @param cont Continuation called once message is sent. Can be NULL.
2867 * @param cont_cls Closure for @c cont.
2868 *
2869 * @return Handle to cancel the message before it's sent.
2870 * NULL on error or if @c cont is NULL.
2871 * Invalid on @c cont call.
2872 */
2873struct CadetConnectionQueue *
2874GMC_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2875 uint16_t payload_type, uint32_t payload_id,
2876 struct CadetConnection *c, int fwd, int force,
2877 GMC_sent cont, void *cont_cls)
2878{
2879 struct CadetFlowControl *fc;
2880 struct CadetConnectionQueue *q;
2881 void *data;
2882 size_t size;
2883 uint16_t type;
2884 int droppable;
2885
2886 size = ntohs (message->size);
2887 data = GNUNET_malloc (size);
2888 memcpy (data, message, size);
2889 type = ntohs (message->type);
2890 LOG (GNUNET_ERROR_TYPE_INFO, "--> %s (%s %u) on connection %s (%u bytes)\n",
2891 GM_m2s (type), GM_m2s (payload_type), payload_id, GMC_2s (c), size);
2892
2893 fc = fwd ? &c->fwd_fc : &c->bck_fc;
2894 droppable = GNUNET_NO == force;
2895 switch (type)
2896 {
2897 struct GNUNET_CADET_Encrypted *emsg;
2898 struct GNUNET_CADET_KX *kmsg;
2899 struct GNUNET_CADET_ACK *amsg;
2900 struct GNUNET_CADET_Poll *pmsg;
2901 struct GNUNET_CADET_ConnectionDestroy *dmsg;
2902 struct GNUNET_CADET_ConnectionBroken *bmsg;
2903 uint32_t ttl;
2904
2905 case GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED:
2906 emsg = (struct GNUNET_CADET_Encrypted *) data;
2907 ttl = ntohl (emsg->ttl);
2908 if (0 == ttl)
2909 {
2910 GNUNET_break_op (0);
2911 GNUNET_free (data);
2912 return NULL;
2913 }
2914 emsg->cid = c->id;
2915 emsg->ttl = htonl (ttl - 1);
2916 emsg->pid = htonl (0);
2917 LOG (GNUNET_ERROR_TYPE_DEBUG, " Q_N+ %p %u\n", fc, fc->queue_n);
2918 LOG (GNUNET_ERROR_TYPE_DEBUG, "last pid sent %u\n", fc->last_pid_sent);
2919 LOG (GNUNET_ERROR_TYPE_DEBUG, " ack recv %u\n", fc->last_ack_recv);
2920 if (GNUNET_YES == droppable)
2921 {
2922 fc->queue_n++;
2923 }
2924 else
2925 {
2926 LOG (GNUNET_ERROR_TYPE_DEBUG, " not droppable, Q_N stays the same\n");
2927 }
2928 if (GM_is_pid_bigger (fc->last_pid_sent + 1, fc->last_ack_recv))
2929 {
2930 GMC_start_poll (c, fwd);
2931 }
2932 break;
2933
2934 case GNUNET_MESSAGE_TYPE_CADET_KX:
2935 kmsg = (struct GNUNET_CADET_KX *) data;
2936 kmsg->cid = c->id;
2937 break;
2938
2939 case GNUNET_MESSAGE_TYPE_CADET_ACK:
2940 amsg = (struct GNUNET_CADET_ACK *) data;
2941 amsg->cid = c->id;
2942 LOG (GNUNET_ERROR_TYPE_DEBUG, " ack %u\n", ntohl (amsg->ack));
2943 droppable = GNUNET_NO;
2944 break;
2945
2946 case GNUNET_MESSAGE_TYPE_CADET_POLL:
2947 pmsg = (struct GNUNET_CADET_Poll *) data;
2948 pmsg->cid = c->id;
2949 LOG (GNUNET_ERROR_TYPE_DEBUG, " poll %u\n", ntohl (pmsg->pid));
2950 droppable = GNUNET_NO;
2951 break;
2952
2953 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY:
2954 dmsg = (struct GNUNET_CADET_ConnectionDestroy *) data;
2955 dmsg->cid = c->id;
2956 break;
2957
2958 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN:
2959 bmsg = (struct GNUNET_CADET_ConnectionBroken *) data;
2960 bmsg->cid = c->id;
2961 break;
2962
2963 case GNUNET_MESSAGE_TYPE_CADET_KEEPALIVE:
2964 GNUNET_break (0);
2965 /* falltrough */
2966 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE:
2967 case GNUNET_MESSAGE_TYPE_CADET_CONNECTION_ACK:
2968 break;
2969
2970 default:
2971 GNUNET_break (0);
2972 GNUNET_free (data);
2973 return NULL;
2974 }
2975
2976 if (fc->queue_n > fc->queue_max && droppable)
2977 {
2978 GNUNET_STATISTICS_update (stats, "# messages dropped (buffer full)",
2979 1, GNUNET_NO);
2980 GNUNET_break (0);
2981 LOG (GNUNET_ERROR_TYPE_DEBUG,
2982 "queue full: %u/%u\n",
2983 fc->queue_n, fc->queue_max);
2984 if (GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED == type)
2985 {
2986 fc->queue_n--;
2987 }
2988 GNUNET_free (data);
2989 return NULL; /* Drop this message */
2990 }
2991
2992 LOG (GNUNET_ERROR_TYPE_DEBUG, " C_P+ %p %u\n", c, c->pending_messages);
2993// c->pending_messages++;
2994
2995 q = GNUNET_new (struct CadetConnectionQueue);
2996 q->forced = !droppable;
2997 q->q = GMP_queue_add (get_hop (c, fwd), data, type, payload_type, payload_id,
2998 size, c, fwd, &conn_message_sent, q);
2999 if (NULL == q->q)
3000 {
3001 LOG (GNUNET_ERROR_TYPE_DEBUG, "WARNING dropping msg on %s\n", GMC_2s (c));
3002 GNUNET_free (data);
3003 GNUNET_free (q);
3004 return NULL;
3005 }
3006 q->cont = cont;
3007 q->cont_cls = cont_cls;
3008 return (NULL == cont) ? NULL : q;
3009}
3010
3011
3012/**
3013 * Cancel a previously sent message while it's in the queue.
3014 *
3015 * ONLY can be called before the continuation given to the send function
3016 * is called. Once the continuation is called, the message is no longer in the
3017 * queue.
3018 *
3019 * @param q Handle to the queue.
3020 */
3021void
3022GMC_cancel (struct CadetConnectionQueue *q)
3023{
3024 LOG (GNUNET_ERROR_TYPE_DEBUG, "! GMC cancel message\n");
3025
3026 /* queue destroy calls message_sent, which calls q->cont and frees q */
3027 GMP_queue_destroy (q->q, GNUNET_YES, GNUNET_NO, 0);
3028}
3029
3030
3031/**
3032 * Sends a CREATE CONNECTION message for a path to a peer.
3033 * Changes the connection and tunnel states if necessary.
3034 *
3035 * @param connection Connection to create.
3036 */
3037void
3038GMC_send_create (struct CadetConnection *connection)
3039{
3040 enum CadetTunnel3CState state;
3041 size_t size;
3042
3043 size = sizeof (struct GNUNET_CADET_ConnectionCreate);
3044 size += connection->path->length * sizeof (struct GNUNET_PeerIdentity);
3045
3046 LOG (GNUNET_ERROR_TYPE_INFO, "===> %s on connection %s (%u bytes)\n",
3047 GM_m2s (GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE),
3048 GMC_2s (connection), size);
3049 LOG (GNUNET_ERROR_TYPE_DEBUG, " C_P+ %p %u (create)\n",
3050 connection, connection->pending_messages);
3051 connection->pending_messages++;
3052
3053 connection->maintenance_q =
3054 GMP_queue_add (get_next_hop (connection), NULL,
3055 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE,
3056 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE, 0,
3057 size, connection, GNUNET_YES, &conn_message_sent, NULL);
3058
3059 state = GMT_get_cstate (connection->t);
3060 if (CADET_TUNNEL3_SEARCHING == state || CADET_TUNNEL3_NEW == state)
3061 GMT_change_cstate (connection->t, CADET_TUNNEL3_WAITING);
3062 if (CADET_CONNECTION_NEW == connection->state)
3063 connection_change_state (connection, CADET_CONNECTION_SENT);
3064}
3065
3066
3067/**
3068 * Send a message to all peers in this connection that the connection
3069 * is no longer valid.
3070 *
3071 * If some peer should not receive the message, it should be zero'ed out
3072 * before calling this function.
3073 *
3074 * @param c The connection whose peers to notify.
3075 */
3076void
3077GMC_send_destroy (struct CadetConnection *c)
3078{
3079 struct GNUNET_CADET_ConnectionDestroy msg;
3080
3081 if (GNUNET_YES == c->destroy)
3082 return;
3083
3084 msg.header.size = htons (sizeof (msg));
3085 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY);;
3086 msg.cid = c->id;
3087 LOG (GNUNET_ERROR_TYPE_DEBUG,
3088 " sending connection destroy for connection %s\n",
3089 GMC_2s (c));
3090
3091 if (GNUNET_NO == GMC_is_terminal (c, GNUNET_YES))
3092 GMC_send_prebuilt_message (&msg.header,
3093 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY, 0,
3094 c, GNUNET_YES, GNUNET_YES, NULL, NULL);
3095 if (GNUNET_NO == GMC_is_terminal (c, GNUNET_NO))
3096 GMC_send_prebuilt_message (&msg.header,
3097 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY, 0,
3098 c, GNUNET_NO, GNUNET_YES, NULL, NULL);
3099 c->destroy = GNUNET_YES;
3100 c->state = CADET_CONNECTION_DESTROYED;
3101}
3102
3103
3104/**
3105 * @brief Start a polling timer for the connection.
3106 *
3107 * When a neighbor does not accept more traffic on the connection it could be
3108 * caused by a simple congestion or by a lost ACK. Polling enables to check
3109 * for the lastest ACK status for a connection.
3110 *
3111 * @param c Connection.
3112 * @param fwd Should we poll in the FWD direction?
3113 */
3114void
3115GMC_start_poll (struct CadetConnection *c, int fwd)
3116{
3117 struct CadetFlowControl *fc;
3118
3119 fc = fwd ? &c->fwd_fc : &c->bck_fc;
3120 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL %s requested\n",
3121 GM_f2s (fwd));
3122 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task || NULL != fc->poll_msg)
3123 {
3124 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** not needed (%u, %p)\n",
3125 fc->poll_task, fc->poll_msg);
3126 return;
3127 }
3128 LOG (GNUNET_ERROR_TYPE_DEBUG, " *** POLL started on request\n");
3129 fc->poll_task = GNUNET_SCHEDULER_add_delayed (fc->poll_time,
3130 &connection_poll,
3131 fc);
3132}
3133
3134
3135/**
3136 * @brief Stop polling a connection for ACKs.
3137 *
3138 * Once we have enough ACKs for future traffic, polls are no longer necessary.
3139 *
3140 * @param c Connection.
3141 * @param fwd Should we stop the poll in the FWD direction?
3142 */
3143void
3144GMC_stop_poll (struct CadetConnection *c, int fwd)
3145{
3146 struct CadetFlowControl *fc;
3147
3148 fc = fwd ? &c->fwd_fc : &c->bck_fc;
3149 if (GNUNET_SCHEDULER_NO_TASK != fc->poll_task)
3150 {
3151 GNUNET_SCHEDULER_cancel (fc->poll_task);
3152 fc->poll_task = GNUNET_SCHEDULER_NO_TASK;
3153 }
3154}
3155
3156/**
3157 * Get a (static) string for a connection.
3158 *
3159 * @param c Connection.
3160 */
3161const char *
3162GMC_2s (const struct CadetConnection *c)
3163{
3164 if (NULL == c)
3165 return "NULL";
3166
3167 if (NULL != c->t)
3168 {
3169 static char buf[128];
3170
3171 sprintf (buf, "%s (->%s)",
3172 GNUNET_h2s (GM_h2hc (GMC_get_id (c))), GMT_2s (c->t));
3173 return buf;
3174 }
3175 return GNUNET_h2s (GM_h2hc (&c->id));
3176}
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-01 08:24:57 +0000