2 This file is part of GNUnet.
3 (C) 2013 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
23 #include "gnunet_util_lib.h"
25 #include "gnunet_statistics_service.h"
28 #include "cadet_protocol.h"
30 #include "gnunet-service-cadet_channel.h"
31 #include "gnunet-service-cadet_local.h"
32 #include "gnunet-service-cadet_tunnel.h"
33 #include "gnunet-service-cadet_peer.h"
35 #define LOG(level, ...) GNUNET_log_from(level,"cadet-chn",__VA_ARGS__)
37 #define CADET_RETRANSMIT_TIME GNUNET_TIME_relative_multiply(\
38 GNUNET_TIME_UNIT_MILLISECONDS, 250)
39 #define CADET_RETRANSMIT_MARGIN 4
43 * All the states a connection can be in.
45 enum CadetChannelState
48 * Uninitialized status, should never appear in operation.
53 * Connection create message sent, waiting for ACK.
58 * Connection confirmed, ready to carry traffic.
65 * Info holder for channel messages in queues.
67 struct CadetChannelQueue
72 struct CadetTunnelQueue *tq;
75 * Message type (DATA/DATA_ACK)
80 * Message copy (for DATAs, to start retransmission timer)
82 struct CadetReliableMessage *copy;
85 * Reliability (for DATA_ACKs, to access rel->ack_q)
87 struct CadetChannelReliability *rel;
92 * Info needed to retry a message in case it gets lost.
94 struct CadetReliableMessage
97 * Double linked list, FIFO style
99 struct CadetReliableMessage *next;
100 struct CadetReliableMessage *prev;
103 * Type of message (payload, channel management).
108 * Tunnel Reliability queue this message is in.
110 struct CadetChannelReliability *rel;
113 * ID of the message (ACK needed to free)
120 struct CadetChannelQueue *chq;
123 * When was this message issued (to calculate ACK delay)
125 struct GNUNET_TIME_Absolute timestamp;
127 /* struct GNUNET_CADET_Data with payload */
132 * Info about the traffic state for a client in a channel.
134 struct CadetChannelReliability
137 * Channel this is about.
139 struct CadetChannel *ch;
142 * DLL of messages sent and not yet ACK'd.
144 struct CadetReliableMessage *head_sent;
145 struct CadetReliableMessage *tail_sent;
148 * DLL of messages received out of order.
150 struct CadetReliableMessage *head_recv;
151 struct CadetReliableMessage *tail_recv;
159 * Next MID to use for outgoing traffic.
164 * Next MID expected for incoming traffic.
169 * Handle for queued unique data CREATE, DATA_ACK.
171 struct CadetChannelQueue *uniq;
174 * Can we send data to the client?
179 * Can the client send data to us?
184 * Task to resend/poll in case no ACK is received.
186 GNUNET_SCHEDULER_TaskIdentifier retry_task;
189 * Counter for exponential backoff.
191 struct GNUNET_TIME_Relative retry_timer;
194 * How long does it usually take to get an ACK.
196 struct GNUNET_TIME_Relative expected_delay;
201 * Struct containing all information regarding a channel to a remote client.
206 * Tunnel this channel is in.
208 struct CadetTunnel *t;
211 * Destination port of the channel.
216 * Global channel number ( < GNUNET_CADET_LOCAL_CHANNEL_ID_CLI)
218 CADET_ChannelNumber gid;
221 * Local tunnel number for root (owner) client.
222 * ( >= GNUNET_CADET_LOCAL_CHANNEL_ID_CLI or 0 )
224 CADET_ChannelNumber lid_root;
227 * Local tunnel number for local destination clients (incoming number)
228 * ( >= GNUNET_CADET_LOCAL_CHANNEL_ID_SERV or 0).
230 CADET_ChannelNumber lid_dest;
235 enum CadetChannelState state;
238 * Is the tunnel bufferless (minimum latency)?
243 * Is the tunnel reliable?
248 * Last time the channel was used
250 struct GNUNET_TIME_Absolute timestamp;
253 * Client owner of the tunnel, if any
255 struct CadetClient *root;
258 * Client destination of the tunnel, if any.
260 struct CadetClient *dest;
263 * Flag to signal the destruction of the channel.
264 * If this is set GNUNET_YES the channel will be destroyed
265 * when the queue is empty.
270 * Total (reliable) messages pending ACK for this channel.
272 unsigned int pending_messages;
276 * Only present (non-NULL) at the owner of a tunnel.
278 struct CadetChannelReliability *root_rel;
282 * Only present (non-NULL) at the destination of a tunnel.
284 struct CadetChannelReliability *dest_rel;
289 /******************************************************************************/
290 /******************************* GLOBALS ***********************************/
291 /******************************************************************************/
294 * Global handle to the statistics service.
296 extern struct GNUNET_STATISTICS_Handle *stats;
299 * Local peer own ID (memory efficient handle).
301 extern GNUNET_PEER_Id myid;
304 /******************************************************************************/
305 /******************************** STATIC ***********************************/
306 /******************************************************************************/
310 * Destroy a reliable message after it has been acknowledged, either by
311 * direct mid ACK or bitfield. Updates the appropriate data structures and
312 * timers and frees all memory.
314 * @param copy Message that is no longer needed: remote peer got it.
315 * @param update_time Is the timing information relevant?
316 * If this message is ACK in a batch the timing information
317 * is skewed by the retransmission, count only for the
318 * retransmitted message.
320 * @return #GNUNET_YES if channel was destroyed as a result of the call,
321 * #GNUNET_NO otherwise.
324 rel_message_free (struct CadetReliableMessage *copy, int update_time);
327 * send a channel create message.
329 * @param ch Channel for which to send.
332 send_create (struct CadetChannel *ch);
335 * Confirm we got a channel create, FWD ack.
337 * @param ch The channel to confirm.
338 * @param fwd Should we send a FWD ACK? (going dest->root)
339 * @param reaction This ACK is a reaction to a duplicate CREATE, don't save.
342 send_ack (struct CadetChannel *ch, int fwd, int reaction);
347 * Test if the channel is loopback: both root and dest are on the local peer.
349 * @param ch Channel to test.
351 * @return #GNUNET_YES if channel is loopback, #GNUNET_NO otherwise.
354 is_loopback (const struct CadetChannel *ch)
357 return GCT_is_loopback (ch->t);
359 return (NULL != ch->root && NULL != ch->dest);
364 * Save a copy of the data message for later retransmission.
366 * @param msg Message to copy.
367 * @param mid Message ID.
368 * @param rel Reliability data for retransmission.
370 static struct CadetReliableMessage *
371 copy_message (const struct GNUNET_CADET_Data *msg, uint32_t mid,
372 struct CadetChannelReliability *rel)
374 struct CadetReliableMessage *copy;
377 size = ntohs (msg->header.size);
378 copy = GNUNET_malloc (sizeof (*copy) + size);
381 copy->type = GNUNET_MESSAGE_TYPE_CADET_DATA;
382 memcpy (©[1], msg, size);
388 * We have received a message out of order, or the client is not ready.
389 * Buffer it until we receive an ACK from the client or the missing
390 * message from the channel.
392 * @param msg Message to buffer (MUST be of type CADET_DATA).
393 * @param rel Reliability data to the corresponding direction.
396 add_buffered_data (const struct GNUNET_CADET_Data *msg,
397 struct CadetChannelReliability *rel)
399 struct CadetReliableMessage *copy;
400 struct CadetReliableMessage *prev;
403 mid = ntohl (msg->mid);
405 LOG (GNUNET_ERROR_TYPE_DEBUG, "add_buffered_data %u\n", mid);
409 // FIXME do something better than O(n), although n < 64...
410 // FIXME start from the end (most messages are the latest ones)
411 for (prev = rel->head_recv; NULL != prev; prev = prev->next)
413 LOG (GNUNET_ERROR_TYPE_DEBUG, " prev %u\n", prev->mid);
414 if (prev->mid == mid)
416 LOG (GNUNET_ERROR_TYPE_DEBUG, " already there!\n");
419 else if (GC_is_pid_bigger (prev->mid, mid))
421 LOG (GNUNET_ERROR_TYPE_DEBUG, " bingo!\n");
422 copy = copy_message (msg, mid, rel);
423 GNUNET_CONTAINER_DLL_insert_before (rel->head_recv, rel->tail_recv,
428 copy = copy_message (msg, mid, rel);
429 LOG (GNUNET_ERROR_TYPE_DEBUG, " insert at tail!\n");
430 GNUNET_CONTAINER_DLL_insert_tail (rel->head_recv, rel->tail_recv, copy);
431 LOG (GNUNET_ERROR_TYPE_DEBUG, "add_buffered_data END\n");
436 * Add a destination client to a channel, initializing all data structures
437 * in the channel and the client.
439 * @param ch Channel to which add the destination.
440 * @param c Client which to add to the channel.
443 add_destination (struct CadetChannel *ch, struct CadetClient *c)
445 if (NULL != ch->dest)
451 /* Assign local id as destination */
452 ch->lid_dest = GML_get_next_chid (c);
454 /* Store in client's hashmap */
455 GML_channel_add (c, ch->lid_dest, ch);
457 GNUNET_break (NULL == ch->dest_rel);
458 ch->dest_rel = GNUNET_new (struct CadetChannelReliability);
459 ch->dest_rel->ch = ch;
460 ch->dest_rel->expected_delay.rel_value_us = 0;
461 ch->dest_rel->retry_timer = CADET_RETRANSMIT_TIME;
468 * Set options in a channel, extracted from a bit flag field.
470 * @param ch Channel to set options to.
471 * @param options Bit array in host byte order.
474 channel_set_options (struct CadetChannel *ch, uint32_t options)
476 ch->nobuffer = (options & GNUNET_CADET_OPTION_NOBUFFER) != 0 ?
477 GNUNET_YES : GNUNET_NO;
478 ch->reliable = (options & GNUNET_CADET_OPTION_RELIABLE) != 0 ?
479 GNUNET_YES : GNUNET_NO;
484 * Get a bit flag field with the options of a channel.
486 * @param ch Channel to get options from.
488 * @return Bit array in host byte order.
491 channel_get_options (struct CadetChannel *ch)
497 options |= GNUNET_CADET_OPTION_NOBUFFER;
499 options |= GNUNET_CADET_OPTION_RELIABLE;
506 * Notify a client that the channel is no longer valid.
508 * @param ch Channel that is destroyed.
509 * @param local_only Should we avoid sending it to other peers?
512 send_destroy (struct CadetChannel *ch, int local_only)
514 struct GNUNET_CADET_ChannelManage msg;
516 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY);
517 msg.header.size = htons (sizeof (msg));
518 msg.chid = htonl (ch->gid);
520 /* If root is not NULL, notify.
521 * If it's NULL, check lid_root. When a local destroy comes in, root
522 * is set to NULL but lid_root is left untouched. In this case, do nothing,
523 * the client is the one who requested the channel to be destroyed.
525 if (NULL != ch->root)
526 GML_send_channel_destroy (ch->root, ch->lid_root);
527 else if (0 == ch->lid_root && GNUNET_NO == local_only)
528 GCCH_send_prebuilt_message (&msg.header, ch, GNUNET_NO, NULL);
530 if (NULL != ch->dest)
531 GML_send_channel_destroy (ch->dest, ch->lid_dest);
532 else if (0 == ch->lid_dest && GNUNET_NO == local_only)
533 GCCH_send_prebuilt_message (&msg.header, ch, GNUNET_YES, NULL);
538 * Notify the destination client that a new incoming channel was created.
540 * @param ch Channel that was created.
543 send_client_create (struct CadetChannel *ch)
547 if (NULL == ch->dest)
551 opt |= GNUNET_YES == ch->reliable ? GNUNET_CADET_OPTION_RELIABLE : 0;
552 opt |= GNUNET_YES == ch->nobuffer ? GNUNET_CADET_OPTION_NOBUFFER : 0;
553 GML_send_channel_create (ch->dest, ch->lid_dest, ch->port, opt,
554 GCT_get_destination (ch->t));
560 * Send data to a client.
562 * If the client is ready, send directly, otherwise buffer while listening
566 * @param msg Message.
567 * @param fwd Is this a fwd (root->dest) message?
570 send_client_data (struct CadetChannel *ch,
571 const struct GNUNET_CADET_Data *msg,
576 if (ch->dest_rel->client_ready)
577 GML_send_data (ch->dest, msg, ch->lid_dest);
579 add_buffered_data (msg, ch->dest_rel);
583 if (ch->root_rel->client_ready)
584 GML_send_data (ch->root, msg, ch->lid_root);
586 add_buffered_data (msg, ch->root_rel);
592 * Send a buffered message to the client, for in order delivery or
593 * as result of client ACK.
595 * @param ch Channel on which to empty the message buffer.
596 * @param c Client to send to.
597 * @param fwd Is this to send FWD data?.
600 send_client_buffered_data (struct CadetChannel *ch,
601 struct CadetClient *c,
604 struct CadetReliableMessage *copy;
605 struct CadetChannelReliability *rel;
607 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_buffered_data\n");
608 rel = fwd ? ch->dest_rel : ch->root_rel;
609 if (GNUNET_NO == rel->client_ready)
611 LOG (GNUNET_ERROR_TYPE_DEBUG, "client not ready\n");
615 copy = rel->head_recv;
616 /* We never buffer channel management messages */
619 if (copy->mid == rel->mid_recv || GNUNET_NO == ch->reliable)
621 struct GNUNET_CADET_Data *msg = (struct GNUNET_CADET_Data *) ©[1];
623 LOG (GNUNET_ERROR_TYPE_DEBUG, " have %u! now expecting %u\n",
624 copy->mid, rel->mid_recv + 1);
625 send_client_data (ch, msg, fwd);
628 GCCH_send_data_ack (ch, fwd);
629 GNUNET_CONTAINER_DLL_remove (rel->head_recv, rel->tail_recv, copy);
630 LOG (GNUNET_ERROR_TYPE_DEBUG, " COPYFREE RECV %p\n", copy);
635 LOG (GNUNET_ERROR_TYPE_DEBUG, " reliable && don't have %u, next is %u\n",
636 rel->mid_recv, copy->mid);
637 if (GNUNET_YES == ch->destroy)
639 /* We don't have the next data piece and the remote peer has closed the
640 * channel. We won't receive it anymore, so just destroy the channel.
641 * FIXME: wait some time to allow other connections to
642 * deliver missing messages
644 send_destroy (ch, GNUNET_YES);
649 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_buffered_data END\n");
654 * Allow a client to send more data.
656 * In case the client was already allowed to send data, do nothing.
659 * @param fwd Is this a FWD ACK? (FWD ACKs are sent to root)
662 send_client_ack (struct CadetChannel *ch, int fwd)
664 struct CadetChannelReliability *rel = fwd ? ch->root_rel : ch->dest_rel;
665 struct CadetClient *c = fwd ? ch->root : ch->dest;
669 GNUNET_break (GNUNET_NO != ch->destroy);
672 LOG (GNUNET_ERROR_TYPE_DEBUG,
673 " sending %s ack to client on channel %s\n",
674 GC_f2s (fwd), GCCH_2s (ch));
682 if (GNUNET_YES == rel->client_allowed)
684 LOG (GNUNET_ERROR_TYPE_DEBUG, " already allowed\n");
687 rel->client_allowed = GNUNET_YES;
689 GML_send_ack (c, fwd ? ch->lid_root : ch->lid_dest);
694 * Notify the root that the destination rejected the channel.
696 * @param ch Rejected channel.
699 send_client_nack (struct CadetChannel *ch)
701 if (NULL == ch->root)
706 GML_send_channel_nack (ch->root, ch->lid_root);
711 * We haven't received an ACK after a certain time: restransmit the message.
713 * @param cls Closure (CadetChannelReliability with the message to restransmit)
714 * @param tc TaskContext.
717 channel_retransmit_message (void *cls,
718 const struct GNUNET_SCHEDULER_TaskContext *tc)
720 struct CadetChannelReliability *rel = cls;
721 struct CadetReliableMessage *copy;
722 struct CadetChannel *ch;
723 struct GNUNET_CADET_Data *payload;
726 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
727 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
731 copy = rel->head_sent;
738 payload = (struct GNUNET_CADET_Data *) ©[1];
739 fwd = (rel == ch->root_rel);
741 /* Message not found in the queue that we are going to use. */
742 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RETRANSMIT %u\n", copy->mid);
744 GCCH_send_prebuilt_message (&payload->header, ch, fwd, copy);
745 GNUNET_STATISTICS_update (stats, "# data retransmitted", 1, GNUNET_NO);
750 * We haven't received an Channel ACK after a certain time: resend the CREATE.
752 * @param cls Closure (CadetChannelReliability of the channel to recreate)
753 * @param tc TaskContext.
756 channel_recreate (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
758 struct CadetChannelReliability *rel = cls;
760 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
761 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
764 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RE-CREATE\n");
765 GNUNET_STATISTICS_update (stats, "# data retransmitted", 1, GNUNET_NO);
767 if (rel == rel->ch->root_rel)
769 send_create (rel->ch);
771 else if (rel == rel->ch->dest_rel)
773 send_ack (rel->ch, GNUNET_YES, GNUNET_NO);
784 * Message has been sent: start retransmission timer.
786 * @param cls Closure (queue structure).
788 * @param q Queue handler (no longer valid).
789 * @param type Type of message.
790 * @param size Size of the message.
793 ch_message_sent (void *cls,
794 struct CadetTunnel *t,
795 struct CadetTunnelQueue *q,
796 uint16_t type, size_t size)
798 struct CadetChannelQueue *chq = cls;
799 struct CadetReliableMessage *copy = chq->copy;
800 struct CadetChannelReliability *rel;
802 LOG (GNUNET_ERROR_TYPE_DEBUG, "channel message sent callback %s\n",
807 case GNUNET_MESSAGE_TYPE_CADET_DATA:
808 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SENT DATA MID %u\n", copy->mid);
809 GNUNET_assert (chq == copy->chq);
810 copy->timestamp = GNUNET_TIME_absolute_get ();
812 if (GNUNET_SCHEDULER_NO_TASK == rel->retry_task)
814 LOG (GNUNET_ERROR_TYPE_DEBUG, "!! scheduling retry in 4 * %s\n",
815 GNUNET_STRINGS_relative_time_to_string (rel->expected_delay,
817 if (0 != rel->expected_delay.rel_value_us)
819 LOG (GNUNET_ERROR_TYPE_DEBUG, "!! delay != 0\n");
821 GNUNET_TIME_relative_multiply (rel->expected_delay,
822 CADET_RETRANSMIT_MARGIN);
826 LOG (GNUNET_ERROR_TYPE_DEBUG, "!! delay reset\n");
827 rel->retry_timer = CADET_RETRANSMIT_TIME;
829 LOG (GNUNET_ERROR_TYPE_DEBUG, "!! using delay %s\n",
830 GNUNET_STRINGS_relative_time_to_string (rel->retry_timer,
833 GNUNET_SCHEDULER_add_delayed (rel->retry_timer,
834 &channel_retransmit_message, rel);
838 LOG (GNUNET_ERROR_TYPE_DEBUG, "!! retry task %u\n", rel->retry_task);
844 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
845 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
846 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
847 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SENT %s\n", GC_m2s (chq->type));
849 GNUNET_assert (rel->uniq == chq);
852 if (CADET_CHANNEL_READY != rel->ch->state
853 && GNUNET_MESSAGE_TYPE_CADET_DATA_ACK != type
854 && GNUNET_NO == rel->ch->destroy)
856 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == rel->retry_task);
857 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! STD BACKOFF %s\n",
858 GNUNET_STRINGS_relative_time_to_string (rel->retry_timer,
860 rel->retry_timer = GNUNET_TIME_STD_BACKOFF (rel->retry_timer);
861 rel->retry_task = GNUNET_SCHEDULER_add_delayed (rel->retry_timer,
862 &channel_recreate, rel);
875 * send a channel create message.
877 * @param ch Channel for which to send.
880 send_create (struct CadetChannel *ch)
882 struct GNUNET_CADET_ChannelCreate msgcc;
884 msgcc.header.size = htons (sizeof (msgcc));
885 msgcc.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE);
886 msgcc.chid = htonl (ch->gid);
887 msgcc.port = htonl (ch->port);
888 msgcc.opt = htonl (channel_get_options (ch));
890 GCCH_send_prebuilt_message (&msgcc.header, ch, GNUNET_YES, NULL);
895 * Confirm we got a channel create or FWD ack.
897 * @param ch The channel to confirm.
898 * @param fwd Should we send a FWD ACK? (going dest->root)
899 * @param reaction This ACK is a reaction to a duplicate CREATE, don't save.
902 send_ack (struct CadetChannel *ch, int fwd, int reaction)
904 struct GNUNET_CADET_ChannelManage msg;
906 msg.header.size = htons (sizeof (msg));
907 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK);
908 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending channel %s ack for channel %s\n",
909 GC_f2s (fwd), GCCH_2s (ch));
911 msg.chid = htonl (ch->gid);
912 GCCH_send_prebuilt_message (&msg.header, ch, !fwd, reaction ? &msg : NULL);
917 * Send a message and don't keep any info about it: we won't need to cancel it
920 * @param msg Header of the message to fire away.
921 * @param ch Channel on which the message should go.
922 * @param force Is this a forced (undroppable) message?
925 fire_and_forget (const struct GNUNET_MessageHeader *msg,
926 struct CadetChannel *ch,
929 GNUNET_break (NULL == GCT_send_prebuilt_message (msg, ch->t, NULL,
935 * Notify that a channel create didn't succeed.
937 * @param ch The channel to reject.
940 send_nack (struct CadetChannel *ch)
942 struct GNUNET_CADET_ChannelManage msg;
944 msg.header.size = htons (sizeof (msg));
945 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK);
946 LOG (GNUNET_ERROR_TYPE_DEBUG,
947 " sending channel NACK for channel %s\n",
950 msg.chid = htonl (ch->gid);
951 GCCH_send_prebuilt_message (&msg.header, ch, GNUNET_NO, NULL);
956 * Destroy all reliable messages queued for a channel,
957 * during a channel destruction.
958 * Frees the reliability structure itself.
960 * @param rel Reliability data for a channel.
963 channel_rel_free_all (struct CadetChannelReliability *rel)
965 struct CadetReliableMessage *copy;
966 struct CadetReliableMessage *next;
971 for (copy = rel->head_recv; NULL != copy; copy = next)
974 GNUNET_CONTAINER_DLL_remove (rel->head_recv, rel->tail_recv, copy);
975 LOG (GNUNET_ERROR_TYPE_DEBUG, " COPYFREE BATCH RECV %p\n", copy);
976 GNUNET_break (NULL == copy->chq);
979 for (copy = rel->head_sent; NULL != copy; copy = next)
982 GNUNET_CONTAINER_DLL_remove (rel->head_sent, rel->tail_sent, copy);
983 LOG (GNUNET_ERROR_TYPE_DEBUG, " COPYFREE BATCH %p\n", copy);
984 if (NULL != copy->chq)
986 if (NULL != copy->chq->tq)
988 GCT_cancel (copy->chq->tq);
989 /* ch_message_sent will free copy->q */
993 GNUNET_free (copy->chq);
999 if (NULL != rel->uniq && NULL != rel->uniq->tq)
1001 GCT_cancel (rel->uniq->tq);
1002 /* ch_message_sent is called freeing uniq */
1004 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
1006 GNUNET_SCHEDULER_cancel (rel->retry_task);
1007 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
1014 * Mark future messages as ACK'd.
1016 * @param rel Reliability data.
1017 * @param msg DataACK message with a bitfield of future ACK'd messages.
1020 channel_rel_free_sent (struct CadetChannelReliability *rel,
1021 const struct GNUNET_CADET_DataACK *msg)
1023 struct CadetReliableMessage *copy;
1024 struct CadetReliableMessage *next;
1031 bitfield = msg->futures;
1032 mid = ntohl (msg->mid);
1033 LOG (GNUNET_ERROR_TYPE_DEBUG, "free_sent_reliable %u %llX\n", mid, bitfield);
1034 LOG (GNUNET_ERROR_TYPE_DEBUG, " rel %p, head %p\n", rel, rel->head_sent);
1035 for (i = 0, copy = rel->head_sent;
1036 i < 64 && NULL != copy && 0 != bitfield;
1039 LOG (GNUNET_ERROR_TYPE_DEBUG, " trying bit %u (mid %u)\n", i, mid + i + 1);
1041 if (0 == (bitfield & mask))
1044 LOG (GNUNET_ERROR_TYPE_DEBUG, " set!\n");
1045 /* Bit was set, clear the bit from the bitfield */
1048 /* The i-th bit was set. Do we have that copy? */
1049 /* Skip copies with mid < target */
1050 target = mid + i + 1;
1051 LOG (GNUNET_ERROR_TYPE_DEBUG, " target %u\n", target);
1052 while (NULL != copy && GC_is_pid_bigger (target, copy->mid))
1055 /* Did we run out of copies? (previously freed, it's ok) */
1058 LOG (GNUNET_ERROR_TYPE_DEBUG, "run out of copies...\n");
1062 /* Did we overshoot the target? (previously freed, it's ok) */
1063 if (GC_is_pid_bigger (copy->mid, target))
1065 LOG (GNUNET_ERROR_TYPE_DEBUG, " next copy %u\n", copy->mid);
1069 /* Now copy->mid == target, free it */
1071 GNUNET_break (GNUNET_YES != rel_message_free (copy, GNUNET_YES));
1074 LOG (GNUNET_ERROR_TYPE_DEBUG, "free_sent_reliable END\n");
1079 * Destroy a reliable message after it has been acknowledged, either by
1080 * direct mid ACK or bitfield. Updates the appropriate data structures and
1081 * timers and frees all memory.
1083 * @param copy Message that is no longer needed: remote peer got it.
1084 * @param update_time Is the timing information relevant?
1085 * If this message is ACK in a batch the timing information
1086 * is skewed by the retransmission, count only for the
1087 * retransmitted message.
1089 * @return #GNUNET_YES if channel was destroyed as a result of the call,
1090 * #GNUNET_NO otherwise.
1093 rel_message_free (struct CadetReliableMessage *copy, int update_time)
1095 struct CadetChannelReliability *rel;
1096 struct GNUNET_TIME_Relative time;
1099 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Freeing %u\n", copy->mid);
1102 time = GNUNET_TIME_absolute_get_duration (copy->timestamp);
1103 if (0 == rel->expected_delay.rel_value_us)
1104 rel->expected_delay = time;
1107 rel->expected_delay.rel_value_us *= 7;
1108 rel->expected_delay.rel_value_us += time.rel_value_us;
1109 rel->expected_delay.rel_value_us /= 8;
1111 LOG (GNUNET_ERROR_TYPE_INFO, "!!! took %s, new delay %s\n",
1112 GNUNET_STRINGS_relative_time_to_string (time, GNUNET_NO),
1113 GNUNET_STRINGS_relative_time_to_string (rel->expected_delay,
1115 rel->retry_timer = rel->expected_delay;
1119 LOG (GNUNET_ERROR_TYPE_INFO, "!!! batch free, ignoring timing\n");
1121 rel->ch->pending_messages--;
1122 if (NULL != copy->chq)
1124 GCT_cancel (copy->chq->tq);
1125 /* copy->q is set to NULL by ch_message_sent */
1127 GNUNET_CONTAINER_DLL_remove (rel->head_sent, rel->tail_sent, copy);
1128 LOG (GNUNET_ERROR_TYPE_DEBUG, " COPYFREE %p\n", copy);
1131 if (GNUNET_NO != rel->ch->destroy && 0 == rel->ch->pending_messages)
1133 GCCH_destroy (rel->ch);
1141 * Channel was ACK'd by remote peer, mark as ready and cancel retransmission.
1143 * @param ch Channel to mark as ready.
1144 * @param fwd Was the ACK message a FWD ACK? (dest->root, SYNACK)
1147 channel_confirm (struct CadetChannel *ch, int fwd)
1149 struct CadetChannelReliability *rel;
1150 enum CadetChannelState oldstate;
1152 rel = fwd ? ch->root_rel : ch->dest_rel;
1155 GNUNET_break (GNUNET_NO != ch->destroy);
1158 LOG (GNUNET_ERROR_TYPE_DEBUG, " channel confirm %s %s\n",
1159 GC_f2s (fwd), GCCH_2s (ch));
1160 oldstate = ch->state;
1161 ch->state = CADET_CHANNEL_READY;
1163 if (CADET_CHANNEL_READY != oldstate || GNUNET_YES == is_loopback (ch))
1165 rel->client_ready = GNUNET_YES;
1166 rel->expected_delay = rel->retry_timer;
1167 LOG (GNUNET_ERROR_TYPE_DEBUG, " !! retry timer confirm %s\n",
1168 GNUNET_STRINGS_relative_time_to_string (rel->retry_timer, GNUNET_NO));
1169 if (GCT_get_connections_buffer (ch->t) > 0 || GCT_is_loopback (ch->t))
1170 send_client_ack (ch, fwd);
1172 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
1174 GNUNET_SCHEDULER_cancel (rel->retry_task);
1175 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
1177 else if (NULL != rel->uniq)
1179 GCT_cancel (rel->uniq->tq);
1180 /* ch_message_sent will free and NULL uniq */
1184 if (GNUNET_NO == is_loopback (ch))
1186 /* We SHOULD have been trying to retransmit this! */
1192 /* In case of a FWD ACK (SYNACK) send a BCK ACK (ACK). */
1193 if (GNUNET_YES == fwd)
1194 send_ack (ch, GNUNET_NO, GNUNET_NO);
1199 * Save a copy to retransmit in case it gets lost.
1201 * Initializes all needed callbacks and timers.
1203 * @param ch Channel this message goes on.
1204 * @param msg Message to copy.
1205 * @param fwd Is this fwd traffic?
1207 static struct CadetReliableMessage *
1208 channel_save_copy (struct CadetChannel *ch,
1209 const struct GNUNET_MessageHeader *msg,
1212 struct CadetChannelReliability *rel;
1213 struct CadetReliableMessage *copy;
1218 rel = fwd ? ch->root_rel : ch->dest_rel;
1219 mid = rel->mid_send - 1;
1220 type = ntohs (msg->type);
1221 size = ntohs (msg->size);
1223 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SAVE %u %s\n", mid, GC_m2s (type));
1224 copy = GNUNET_malloc (sizeof (struct CadetReliableMessage) + size);
1225 LOG (GNUNET_ERROR_TYPE_DEBUG, " at %p\n", copy);
1229 memcpy (©[1], msg, size);
1230 GNUNET_CONTAINER_DLL_insert_tail (rel->head_sent, rel->tail_sent, copy);
1231 ch->pending_messages++;
1238 * Create a new channel.
1240 * @param t Tunnel this channel is in.
1241 * @param owner Client that owns the channel, NULL for foreign channels.
1242 * @param lid_root Local ID for root client.
1244 * @return A new initialized channel. NULL on error.
1246 static struct CadetChannel *
1247 channel_new (struct CadetTunnel *t,
1248 struct CadetClient *owner,
1249 CADET_ChannelNumber lid_root)
1251 struct CadetChannel *ch;
1253 ch = GNUNET_new (struct CadetChannel);
1255 ch->lid_root = lid_root;
1258 GNUNET_STATISTICS_update (stats, "# channels", 1, GNUNET_NO);
1262 ch->gid = GCT_get_next_chid (t);
1263 GML_channel_add (owner, lid_root, ch);
1265 GCT_add_channel (t, ch);
1272 * Handle a loopback message: call the appropriate handler for the message type.
1274 * @param ch Channel this message is on.
1275 * @param msgh Message header.
1276 * @param fwd Is this FWD traffic?
1279 handle_loopback (struct CadetChannel *ch,
1280 const struct GNUNET_MessageHeader *msgh,
1285 type = ntohs (msgh->type);
1286 LOG (GNUNET_ERROR_TYPE_DEBUG,
1287 "Loopback %s %s message!\n",
1288 GC_f2s (fwd), GC_m2s (type));
1292 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1293 /* Don't send hop ACK, wait for client to ACK */
1294 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SEND loopback %u (%u)\n",
1295 ntohl (((struct GNUNET_CADET_Data *) msgh)->mid), ntohs (msgh->size));
1296 GCCH_handle_data (ch, (struct GNUNET_CADET_Data *) msgh, fwd);
1299 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1300 GCCH_handle_data_ack (ch, (struct GNUNET_CADET_DataACK *) msgh, fwd);
1303 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1304 GCCH_handle_create (ch->t,
1305 (struct GNUNET_CADET_ChannelCreate *) msgh);
1308 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1309 GCCH_handle_ack (ch,
1310 (struct GNUNET_CADET_ChannelManage *) msgh,
1314 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1315 GCCH_handle_nack (ch);
1318 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1319 GCCH_handle_destroy (ch,
1320 (struct GNUNET_CADET_ChannelManage *) msgh,
1325 GNUNET_break_op (0);
1326 LOG (GNUNET_ERROR_TYPE_DEBUG,
1327 "end-to-end message not known (%u)\n",
1328 ntohs (msgh->type));
1334 /******************************************************************************/
1335 /******************************** API ***********************************/
1336 /******************************************************************************/
1339 * Destroy a channel and free all resources.
1341 * @param ch Channel to destroy.
1344 GCCH_destroy (struct CadetChannel *ch)
1346 struct CadetClient *c;
1347 struct CadetTunnel *t;
1351 if (2 == ch->destroy)
1352 return; /* recursive call */
1355 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying channel %s:%u\n",
1356 GCT_2s (ch->t), ch->gid);
1362 GML_channel_remove (c, ch->lid_root, ch);
1368 GML_channel_remove (c, ch->lid_dest, ch);
1371 channel_rel_free_all (ch->root_rel);
1372 channel_rel_free_all (ch->dest_rel);
1375 GCT_remove_channel (t, ch);
1376 GNUNET_STATISTICS_update (stats, "# channels", -1, GNUNET_NO);
1379 GCT_destroy_if_empty (t);
1384 * Get the channel's public ID.
1386 * @param ch Channel.
1388 * @return ID used to identify the channel with the remote peer.
1391 GCCH_get_id (const struct CadetChannel *ch)
1398 * Get the channel tunnel.
1400 * @param ch Channel to get the tunnel from.
1402 * @return tunnel of the channel.
1404 struct CadetTunnel *
1405 GCCH_get_tunnel (const struct CadetChannel *ch)
1412 * Get free buffer space towards the client on a specific channel.
1414 * @param ch Channel.
1415 * @param fwd Is query about FWD traffic?
1417 * @return Free buffer space [0 - 64]
1420 GCCH_get_buffer (struct CadetChannel *ch, int fwd)
1422 struct CadetChannelReliability *rel;
1424 rel = fwd ? ch->dest_rel : ch->root_rel;
1426 /* If rel is NULL it means that the end is not yet created,
1427 * most probably is a loopback channel at the point of sending
1428 * the ChannelCreate to itself.
1433 return (64 - rel->n_recv);
1438 * Get flow control status of end point: is client allow to send?
1440 * @param ch Channel.
1441 * @param fwd Is query about FWD traffic? (Request root status).
1443 * @return #GNUNET_YES if client is allowed to send us data.
1446 GCCH_get_allowed (struct CadetChannel *ch, int fwd)
1448 struct CadetChannelReliability *rel;
1450 rel = fwd ? ch->root_rel : ch->dest_rel;
1454 /* Probably shutting down: root/dest NULL'ed to mark disconnection */
1455 GNUNET_break (GNUNET_NO != ch->destroy);
1459 return rel->client_allowed;
1464 * Is the root client for this channel on this peer?
1466 * @param ch Channel.
1467 * @param fwd Is this for fwd traffic?
1469 * @return #GNUNET_YES in case it is.
1472 GCCH_is_origin (struct CadetChannel *ch, int fwd)
1474 struct CadetClient *c;
1476 c = fwd ? ch->root : ch->dest;
1482 * Is the destination client for this channel on this peer?
1484 * @param ch Channel.
1485 * @param fwd Is this for fwd traffic?
1487 * @return #GNUNET_YES in case it is.
1490 GCCH_is_terminal (struct CadetChannel *ch, int fwd)
1492 struct CadetClient *c;
1494 c = fwd ? ch->dest : ch->root;
1500 * Send an end-to-end ACK message for the most recent in-sequence payload.
1502 * If channel is not reliable, do nothing.
1504 * @param ch Channel this is about.
1505 * @param fwd Is for FWD traffic? (ACK dest->owner)
1508 GCCH_send_data_ack (struct CadetChannel *ch, int fwd)
1510 struct GNUNET_CADET_DataACK msg;
1511 struct CadetChannelReliability *rel;
1512 struct CadetReliableMessage *copy;
1517 if (GNUNET_NO == ch->reliable)
1520 rel = fwd ? ch->dest_rel : ch->root_rel;
1521 ack = rel->mid_recv - 1;
1522 LOG (GNUNET_ERROR_TYPE_INFO, "===> DATA_ACK for %u\n", ack);
1524 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_DATA_ACK);
1525 msg.header.size = htons (sizeof (msg));
1526 msg.chid = htonl (ch->gid);
1527 msg.mid = htonl (ack);
1530 for (copy = rel->head_recv; NULL != copy; copy = copy->next)
1532 if (copy->type != GNUNET_MESSAGE_TYPE_CADET_DATA)
1534 LOG (GNUNET_ERROR_TYPE_DEBUG, " Type %s, expected DATA\n",
1535 GC_m2s (copy->type));
1538 delta = copy->mid - (ack + 1);
1541 mask = 0x1LL << delta;
1542 msg.futures |= mask;
1543 LOG (GNUNET_ERROR_TYPE_DEBUG,
1544 " setting bit for %u (delta %u) (%llX) -> %llX\n",
1545 copy->mid, delta, mask, msg.futures);
1547 LOG (GNUNET_ERROR_TYPE_DEBUG, " final futures: %llX\n", ack, msg.futures);
1549 GCCH_send_prebuilt_message (&msg.header, ch, !fwd, NULL);
1550 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_data_ack END\n");
1555 * Allow a client to send us more data, in case it was choked.
1557 * @param ch Channel.
1558 * @param fwd Is this about FWD traffic? (Root client).
1561 GCCH_allow_client (struct CadetChannel *ch, int fwd)
1563 struct CadetChannelReliability *rel;
1564 unsigned int buffer;
1566 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMCH allow\n");
1568 if (CADET_CHANNEL_READY != ch->state)
1570 LOG (GNUNET_ERROR_TYPE_DEBUG, " channel not ready yet!\n");
1574 if (GNUNET_YES == ch->reliable)
1576 rel = fwd ? ch->root_rel : ch->dest_rel;
1579 GNUNET_break (GNUNET_NO != ch->destroy);
1582 if (NULL != rel->head_sent)
1584 if (64 <= rel->mid_send - rel->head_sent->mid)
1586 LOG (GNUNET_ERROR_TYPE_DEBUG, " too big MID gap! Wait for ACK.\n");
1591 LOG (GNUNET_ERROR_TYPE_DEBUG, " gap ok: %u - %u\n",
1592 rel->head_sent->mid, rel->mid_send);
1593 struct CadetReliableMessage *aux;
1594 for (aux = rel->head_sent; NULL != aux; aux = aux->next)
1596 LOG (GNUNET_ERROR_TYPE_DEBUG, " - sent MID %u\n", aux->mid);
1602 LOG (GNUNET_ERROR_TYPE_DEBUG, " head sent is NULL\n");
1606 if (is_loopback (ch))
1607 buffer = GCCH_get_buffer (ch, fwd);
1609 buffer = GCT_get_connections_buffer (ch->t);
1613 LOG (GNUNET_ERROR_TYPE_DEBUG, " no buffer space.\n");
1617 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space %u, allowing\n", buffer);
1618 send_client_ack (ch, fwd);
1625 * @param ch Channel.
1628 GCCH_debug (struct CadetChannel *ch)
1632 LOG (GNUNET_ERROR_TYPE_DEBUG, "*** DEBUG NULL CHANNEL ***\n");
1635 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %s:%X (%p)\n",
1636 GCT_2s (ch->t), ch->gid, ch);
1637 LOG (GNUNET_ERROR_TYPE_DEBUG, " root %p/%p\n",
1638 ch->root, ch->root_rel);
1639 if (NULL != ch->root)
1641 LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->root));
1642 LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n",
1643 ch->root_rel->client_ready ? "YES" : "NO");
1644 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_root);
1646 LOG (GNUNET_ERROR_TYPE_DEBUG, " dest %p/%p\n",
1647 ch->dest, ch->dest_rel);
1648 if (NULL != ch->dest)
1650 LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->dest));
1651 LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n",
1652 ch->dest_rel->client_ready ? "YES" : "NO");
1653 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_dest);
1659 * Handle an ACK given by a client.
1661 * Mark client as ready and send him any buffered data we could have for him.
1663 * @param ch Channel.
1664 * @param fwd Is this a "FWD ACK"? (FWD ACKs are sent by dest and go BCK)
1667 GCCH_handle_local_ack (struct CadetChannel *ch, int fwd)
1669 struct CadetChannelReliability *rel;
1670 struct CadetClient *c;
1672 rel = fwd ? ch->dest_rel : ch->root_rel;
1673 c = fwd ? ch->dest : ch->root;
1675 rel->client_ready = GNUNET_YES;
1676 send_client_buffered_data (ch, c, fwd);
1678 if (GNUNET_YES == ch->destroy && 0 == rel->n_recv)
1680 send_destroy (ch, GNUNET_YES);
1683 /* if loopback is marked for destruction, no need to ACK to the other peer,
1684 * it requested the destruction and is already gone, therefore, else if.
1686 else if (is_loopback (ch))
1688 unsigned int buffer;
1690 buffer = GCCH_get_buffer (ch, fwd);
1692 GCCH_allow_client (ch, fwd);
1696 GCT_send_connection_acks (ch->t);
1701 * Handle data given by a client.
1703 * Check whether the client is allowed to send in this tunnel, save if channel
1704 * is reliable and send an ACK to the client if there is still buffer space
1707 * @param ch Channel.
1708 * @param c Client which sent the data.
1709 * @param message Message.
1710 * @param fwd Is this a FWD data?
1712 * @return GNUNET_OK if everything goes well, GNUNET_SYSERR in case of en error.
1715 GCCH_handle_local_data (struct CadetChannel *ch,
1716 struct CadetClient *c,
1717 struct GNUNET_MessageHeader *message,
1720 struct CadetChannelReliability *rel;
1721 struct GNUNET_CADET_Data *payload;
1722 size_t size = ntohs (message->size);
1723 uint16_t p2p_size = sizeof(struct GNUNET_CADET_Data) + size;
1724 unsigned char cbuf[p2p_size];
1726 /* Is the client in the channel? */
1733 GNUNET_break_op (0);
1734 return GNUNET_SYSERR;
1737 rel = fwd ? ch->root_rel : ch->dest_rel;
1739 if (GNUNET_NO == rel->client_allowed)
1741 GNUNET_break_op (0);
1742 return GNUNET_SYSERR;
1745 rel->client_allowed = GNUNET_NO;
1747 /* Ok, everything is correct, send the message. */
1748 payload = (struct GNUNET_CADET_Data *) cbuf;
1749 payload->mid = htonl (rel->mid_send);
1751 memcpy (&payload[1], message, size);
1752 payload->header.size = htons (p2p_size);
1753 payload->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_DATA);
1754 payload->chid = htonl (ch->gid);
1755 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channel...\n");
1756 GCCH_send_prebuilt_message (&payload->header, ch, fwd, NULL);
1758 if (is_loopback (ch))
1760 if (GCCH_get_buffer (ch, fwd) > 0)
1761 GCCH_allow_client (ch, fwd);
1766 if (GCT_get_connections_buffer (ch->t) > 0)
1768 GCCH_allow_client (ch, fwd);
1776 * Handle a channel destroy requested by a client.
1778 * Destroy the channel and the tunnel in case this was the last channel.
1780 * @param ch Channel.
1781 * @param c Client that requested the destruction (to avoid notifying him).
1782 * @param is_root Is the request coming from root?
1785 GCCH_handle_local_destroy (struct CadetChannel *ch,
1786 struct CadetClient *c,
1789 ch->destroy = GNUNET_YES;
1790 /* Cleanup after the tunnel */
1791 if (GNUNET_NO == is_root && c == ch->dest)
1793 LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is destination.\n", GML_2s (c));
1794 GML_client_delete_channel (c, ch, ch->lid_dest);
1797 if (GNUNET_YES == is_root && c == ch->root)
1799 LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is owner.\n", GML_2s (c));
1800 GML_client_delete_channel (c, ch, ch->lid_root);
1804 send_destroy (ch, GNUNET_NO);
1805 if (0 == ch->pending_messages)
1811 * Handle a channel create requested by a client.
1813 * Create the channel and the tunnel in case this was the first0 channel.
1815 * @param c Client that requested the creation (will be the root).
1816 * @param msg Create Channel message.
1818 * @return GNUNET_OK if everything went fine, GNUNET_SYSERR otherwise.
1821 GCCH_handle_local_create (struct CadetClient *c,
1822 struct GNUNET_CADET_ChannelMessage *msg)
1824 struct CadetChannel *ch;
1825 struct CadetTunnel *t;
1826 struct CadetPeer *peer;
1827 CADET_ChannelNumber chid;
1829 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s:%u\n",
1830 GNUNET_i2s (&msg->peer), ntohl (msg->port));
1831 chid = ntohl (msg->channel_id);
1833 /* Sanity check for duplicate channel IDs */
1834 if (NULL != GML_channel_get (c, chid))
1837 return GNUNET_SYSERR;
1840 peer = GCP_get (&msg->peer);
1841 GCP_add_tunnel (peer);
1842 t = GCP_get_tunnel (peer);
1844 if (GCP_get_short_id (peer) == myid)
1846 GCT_change_cstate (t, CADET_TUNNEL_READY);
1850 /* FIXME change to a tunnel API, eliminate ch <-> peer connection */
1854 /* Create channel */
1855 ch = channel_new (t, c, chid);
1859 return GNUNET_SYSERR;
1861 ch->port = ntohl (msg->port);
1862 channel_set_options (ch, ntohl (msg->opt));
1864 /* In unreliable channels, we'll use the DLL to buffer BCK data */
1865 ch->root_rel = GNUNET_new (struct CadetChannelReliability);
1866 ch->root_rel->ch = ch;
1867 ch->root_rel->retry_timer = CADET_RETRANSMIT_TIME;
1868 ch->root_rel->expected_delay.rel_value_us = 0;
1870 LOG (GNUNET_ERROR_TYPE_DEBUG, "CREATED CHANNEL %s\n", GCCH_2s (ch));
1879 * Handler for cadet network payload traffic.
1881 * @param ch Channel for the message.
1882 * @param msg Unencryted data message.
1883 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1884 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1885 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1886 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1889 GCCH_handle_data (struct CadetChannel *ch,
1890 const struct GNUNET_CADET_Data *msg,
1893 struct CadetChannelReliability *rel;
1894 struct CadetClient *c;
1897 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1898 if (GNUNET_SYSERR == fwd)
1900 if (is_loopback (ch))
1902 /* It is a loopback channel after all... */
1906 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1909 /* Initialize FWD/BCK data */
1910 c = fwd ? ch->dest : ch->root;
1911 rel = fwd ? ch->dest_rel : ch->root_rel;
1915 GNUNET_break (GNUNET_NO != ch->destroy);
1919 if (CADET_CHANNEL_READY != ch->state)
1921 if (GNUNET_NO == fwd)
1923 /* If we are the root, this means the other peer has sent traffic before
1924 * receiving our ACK. Even if the SYNACK goes missing, no traffic should
1925 * be sent before the ACK.
1927 GNUNET_break_op (0);
1930 /* If we are the dest, this means that the SYNACK got to the root but
1931 * the ACK went missing. Treat this as an ACK.
1933 channel_confirm (ch, GNUNET_NO);
1936 GNUNET_STATISTICS_update (stats, "# data received", 1, GNUNET_NO);
1938 mid = ntohl (msg->mid);
1939 LOG (GNUNET_ERROR_TYPE_INFO, "<=== DATA %u %s on channel %s\n",
1940 mid, GC_f2s (fwd), GCCH_2s (ch));
1942 if (GNUNET_NO == ch->reliable ||
1943 ( !GC_is_pid_bigger (rel->mid_recv, mid) &&
1944 GC_is_pid_bigger (rel->mid_recv + 64, mid) ) )
1946 LOG (GNUNET_ERROR_TYPE_DEBUG, "RECV %u (%u)\n",
1947 mid, ntohs (msg->header.size));
1948 if (GNUNET_YES == ch->reliable)
1950 /* Is this the exact next expected messasge? */
1951 if (mid == rel->mid_recv)
1953 LOG (GNUNET_ERROR_TYPE_DEBUG, "as expected, sending to client\n");
1955 send_client_data (ch, msg, fwd);
1959 LOG (GNUNET_ERROR_TYPE_DEBUG, "save for later\n");
1960 add_buffered_data (msg, rel);
1965 /* Tunnel is unreliable: send to clients directly */
1966 /* FIXME: accept Out Of Order traffic */
1967 rel->mid_recv = mid + 1;
1968 send_client_data (ch, msg, fwd);
1973 GNUNET_break_op (GC_is_pid_bigger (rel->mid_recv, mid));
1974 LOG (GNUNET_ERROR_TYPE_WARNING,
1975 "MID %u on channel %s not expected (window: %u - %u). Dropping!\n",
1976 mid, GCCH_2s (ch), rel->mid_recv, rel->mid_recv + 63);
1979 GCCH_send_data_ack (ch, fwd);
1984 * Handler for cadet network traffic end-to-end ACKs.
1986 * @param ch Channel on which we got this message.
1987 * @param msg Data message.
1988 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1989 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1990 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1991 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1994 GCCH_handle_data_ack (struct CadetChannel *ch,
1995 const struct GNUNET_CADET_DataACK *msg,
1998 struct CadetChannelReliability *rel;
1999 struct CadetReliableMessage *copy;
2000 struct CadetReliableMessage *next;
2004 /* If this is a remote (non-loopback) channel, find 'fwd'. */
2005 if (GNUNET_SYSERR == fwd)
2007 if (is_loopback (ch))
2009 /* It is a loopback channel after all... */
2013 /* Inverted: if message came 'FWD' is a 'BCK ACK'. */
2014 fwd = (NULL != ch->dest) ? GNUNET_NO : GNUNET_YES;
2017 ack = ntohl (msg->mid);
2018 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s ACK %u + %X\n",
2019 GC_f2s (fwd), ack, msg->futures);
2021 if (GNUNET_YES == fwd)
2031 GNUNET_break_op (GNUNET_NO != ch->destroy);
2035 /* Free ACK'd copies: no need to retransmit those anymore FIXME refactor */
2036 for (work = GNUNET_NO, copy = rel->head_sent; copy != NULL; copy = next)
2038 if (GC_is_pid_bigger (copy->mid, ack))
2040 LOG (GNUNET_ERROR_TYPE_DEBUG, " head %u, out!\n", copy->mid);
2041 channel_rel_free_sent (rel, msg);
2045 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %u\n", copy->mid);
2047 if (GNUNET_YES == rel_message_free (copy, GNUNET_YES))
2051 /* ACK client if needed and possible */
2052 GCCH_allow_client (ch, fwd);
2054 /* If some message was free'd, update the retransmission delay */
2055 if (GNUNET_YES == work)
2057 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
2059 GNUNET_SCHEDULER_cancel (rel->retry_task);
2060 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
2061 if (NULL != rel->head_sent && NULL == rel->head_sent->chq)
2063 struct GNUNET_TIME_Absolute new_target;
2064 struct GNUNET_TIME_Relative delay;
2066 delay = GNUNET_TIME_relative_multiply (rel->retry_timer,
2067 CADET_RETRANSMIT_MARGIN);
2068 new_target = GNUNET_TIME_absolute_add (rel->head_sent->timestamp,
2070 delay = GNUNET_TIME_absolute_get_remaining (new_target);
2072 GNUNET_SCHEDULER_add_delayed (delay,
2073 &channel_retransmit_message,
2079 /* Work was done but no task was pending? Shouldn't happen! */
2087 * Handler for channel create messages.
2089 * Does not have fwd parameter because it's always 'FWD': channel is incoming.
2091 * @param t Tunnel this channel will be in.
2092 * @param msg Channel crate message.
2094 struct CadetChannel *
2095 GCCH_handle_create (struct CadetTunnel *t,
2096 const struct GNUNET_CADET_ChannelCreate *msg)
2098 CADET_ChannelNumber chid;
2099 struct CadetChannel *ch;
2100 struct CadetClient *c;
2104 reaction = GNUNET_NO;
2105 chid = ntohl (msg->chid);
2106 ch = GCT_get_channel (t, chid);
2109 /* Create channel */
2110 ch = channel_new (t, NULL, 0);
2112 channel_set_options (ch, ntohl (msg->opt));
2113 new_channel = GNUNET_YES;
2117 new_channel = GNUNET_NO;
2120 if (GNUNET_YES == new_channel || GCT_is_loopback (t))
2122 /* Find a destination client */
2123 ch->port = ntohl (msg->port);
2124 LOG (GNUNET_ERROR_TYPE_DEBUG, " port %u\n", ch->port);
2125 c = GML_client_get_by_port (ch->port);
2128 LOG (GNUNET_ERROR_TYPE_DEBUG, " no client has port registered\n");
2129 if (is_loopback (ch))
2131 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback: destroy on handler\n");
2136 LOG (GNUNET_ERROR_TYPE_DEBUG, " not loopback: destroy now\n");
2144 LOG (GNUNET_ERROR_TYPE_DEBUG, " client %p has port registered\n", c);
2147 add_destination (ch, c);
2148 if (GNUNET_YES == ch->reliable)
2149 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Reliable\n");
2151 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Not Reliable\n");
2153 send_client_create (ch);
2154 ch->state = CADET_CHANNEL_SENT;
2158 LOG (GNUNET_ERROR_TYPE_DEBUG, " duplicate create channel\n");
2159 reaction = GNUNET_YES;
2160 if (GNUNET_SCHEDULER_NO_TASK != ch->dest_rel->retry_task)
2162 LOG (GNUNET_ERROR_TYPE_DEBUG, " clearing retry task\n");
2163 /* we were waiting to re-send our 'SYNACK', wait no more! */
2164 GNUNET_SCHEDULER_cancel (ch->dest_rel->retry_task);
2165 ch->dest_rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
2168 send_ack (ch, GNUNET_YES, reaction);
2175 * Handler for channel NACK messages.
2177 * NACK messages always go dest -> root, no need for 'fwd' or 'msg' parameter.
2179 * @param ch Channel.
2182 GCCH_handle_nack (struct CadetChannel *ch)
2184 send_client_nack (ch);
2190 * Handler for channel ack messages.
2192 * @param ch Channel.
2193 * @param msg Message.
2194 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2195 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2196 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2197 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2200 GCCH_handle_ack (struct CadetChannel *ch,
2201 const struct GNUNET_CADET_ChannelManage *msg,
2204 /* If this is a remote (non-loopback) channel, find 'fwd'. */
2205 if (GNUNET_SYSERR == fwd)
2207 if (is_loopback (ch))
2209 /* It is a loopback channel after all... */
2213 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
2216 channel_confirm (ch, !fwd);
2221 * Handler for channel destroy messages.
2223 * @param ch Channel to be destroyed of.
2224 * @param msg Message.
2225 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2226 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2227 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2228 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2231 GCCH_handle_destroy (struct CadetChannel *ch,
2232 const struct GNUNET_CADET_ChannelManage *msg,
2235 struct CadetChannelReliability *rel;
2237 /* If this is a remote (non-loopback) channel, find 'fwd'. */
2238 if (GNUNET_SYSERR == fwd)
2240 if (is_loopback (ch))
2242 /* It is a loopback channel after all... */
2246 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
2250 if ( (fwd && NULL == ch->dest) || (!fwd && NULL == ch->root) )
2252 /* Not for us (don't destroy twice a half-open loopback channel) */
2256 rel = fwd ? ch->dest_rel : ch->root_rel;
2257 if (0 == rel->n_recv)
2259 send_destroy (ch, GNUNET_YES);
2264 ch->destroy = GNUNET_YES;
2270 * Sends an already built message on a channel.
2272 * If the channel is on a loopback tunnel, notifies the appropriate destination
2275 * On a normal channel passes the message to the tunnel for encryption and
2276 * sending on a connection.
2278 * This function DOES NOT save the message for retransmission.
2280 * @param message Message to send. Function makes a copy of it.
2281 * @param ch Channel on which this message is transmitted.
2282 * @param fwd Is this a fwd message?
2283 * @param existing_copy This is a retransmission, don't save a copy.
2286 GCCH_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2287 struct CadetChannel *ch, int fwd,
2288 void *existing_copy)
2290 struct CadetChannelQueue *chq;
2293 type = ntohs (message->type);
2294 LOG (GNUNET_ERROR_TYPE_INFO, "===> %s %s on channel %s\n",
2295 GC_m2s (type), GC_f2s (fwd), GCCH_2s (ch));
2297 if (GCT_is_loopback (ch->t))
2299 handle_loopback (ch, message, fwd);
2305 struct GNUNET_CADET_Data *payload;
2306 case GNUNET_MESSAGE_TYPE_CADET_DATA:
2308 payload = (struct GNUNET_CADET_Data *) message;
2309 LOG (GNUNET_ERROR_TYPE_INFO, "===> %s %u\n",
2310 GC_m2s (type), ntohl (payload->mid));
2311 if (GNUNET_YES == ch->reliable)
2313 chq = GNUNET_new (struct CadetChannelQueue);
2315 if (NULL == existing_copy)
2316 chq->copy = channel_save_copy (ch, message, fwd);
2319 chq->copy = (struct CadetReliableMessage *) existing_copy;
2320 if (NULL != chq->copy->chq)
2322 /* Last retransmission was queued but not yet sent!
2323 * This retransmission was scheduled by a ch_message_sent which
2324 * followed a very fast RTT, so the tiny delay made the
2325 * retransmission function to execute before the previous
2326 * retransmitted message even had a chance to leave the peer.
2327 * Cancel this message and wait until the pending
2328 * retransmission leaves the peer and ch_message_sent starts
2329 * the timer for the next one.
2332 LOG (GNUNET_ERROR_TYPE_DEBUG,
2333 " exisitng copy not yet transmitted!\n");
2336 LOG (GNUNET_ERROR_TYPE_DEBUG,
2337 " using existing copy: %p {r:%p q:%p t:%u}\n",
2339 chq->copy->rel, chq->copy->chq, chq->copy->type);
2341 LOG (GNUNET_ERROR_TYPE_DEBUG, " new chq: %p\n", chq);
2342 chq->copy->chq = chq;
2343 chq->tq = GCT_send_prebuilt_message (message, ch->t, NULL,
2344 NULL != existing_copy,
2345 &ch_message_sent, chq);
2346 /* q itself is stored in copy */
2347 GNUNET_assert (NULL != chq->tq || GNUNET_NO != ch->destroy);
2351 fire_and_forget (message, ch, GNUNET_NO);
2356 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
2357 if (GNUNET_YES == fwd || NULL != existing_copy)
2359 /* BCK ACK (going FWD) is just a response for a SYNACK, don't keep*/
2360 fire_and_forget (message, ch, GNUNET_YES);
2364 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
2365 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
2366 chq = GNUNET_new (struct CadetChannelQueue);
2368 chq->rel = fwd ? ch->root_rel : ch->dest_rel;
2369 if (NULL != chq->rel->uniq)
2371 if (NULL != chq->rel->uniq->tq)
2373 GCT_cancel (chq->rel->uniq->tq);
2374 /* ch_message_sent is called, freeing and NULLing uniq */
2379 GNUNET_free (chq->rel->uniq);
2382 chq->tq = GCT_send_prebuilt_message (message, ch->t, NULL, GNUNET_YES,
2383 &ch_message_sent, chq);
2384 if (NULL == chq->tq)
2391 chq->rel->uniq = chq;
2395 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
2396 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
2397 fire_and_forget (message, ch, GNUNET_YES);
2403 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s unknown!\n", GC_m2s (type));
2404 fire_and_forget (message, ch, GNUNET_YES);
2410 * Get the static string for identification of the channel.
2412 * @param ch Channel.
2414 * @return Static string with the channel IDs.
2417 GCCH_2s (const struct CadetChannel *ch)
2419 static char buf[64];
2422 return "(NULL Channel)";
2424 sprintf (buf, "%s:%u gid:%X (%X / %X)",
2425 GCT_2s (ch->t), ch->port, ch->gid, ch->lid_root, ch->lid_dest);