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)
578 GML_send_data (ch->dest, msg, ch->lid_dest);
579 ch->dest_rel->client_ready = GNUNET_NO;
580 ch->dest_rel->mid_recv++;
583 add_buffered_data (msg, ch->dest_rel);
587 if (ch->root_rel->client_ready)
589 GML_send_data (ch->root, msg, ch->lid_root);
590 ch->root_rel->client_ready = GNUNET_NO;
591 ch->root_rel->mid_recv++;
594 add_buffered_data (msg, ch->root_rel);
600 * Send a buffered message to the client, for in order delivery or
601 * as result of client ACK.
603 * @param ch Channel on which to empty the message buffer.
604 * @param c Client to send to.
605 * @param fwd Is this to send FWD data?.
608 send_client_buffered_data (struct CadetChannel *ch,
609 struct CadetClient *c,
612 struct CadetReliableMessage *copy;
613 struct CadetChannelReliability *rel;
615 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_buffered_data\n");
616 rel = fwd ? ch->dest_rel : ch->root_rel;
617 if (GNUNET_NO == rel->client_ready)
619 LOG (GNUNET_ERROR_TYPE_DEBUG, "client not ready\n");
623 copy = rel->head_recv;
624 /* We never buffer channel management messages */
627 if (copy->mid == rel->mid_recv || GNUNET_NO == ch->reliable)
629 struct GNUNET_CADET_Data *msg = (struct GNUNET_CADET_Data *) ©[1];
631 LOG (GNUNET_ERROR_TYPE_DEBUG, " have %u! now expecting %u\n",
632 copy->mid, rel->mid_recv + 1);
633 send_client_data (ch, msg, fwd);
635 GNUNET_CONTAINER_DLL_remove (rel->head_recv, rel->tail_recv, copy);
636 LOG (GNUNET_ERROR_TYPE_DEBUG, " COPYFREE RECV %p\n", copy);
638 GCCH_send_data_ack (ch, fwd);
642 LOG (GNUNET_ERROR_TYPE_DEBUG, " reliable && don't have %u, next is %u\n",
643 rel->mid_recv, copy->mid);
644 if (GNUNET_YES == ch->destroy)
646 /* We don't have the next data piece and the remote peer has closed the
647 * channel. We won't receive it anymore, so just destroy the channel.
648 * FIXME: wait some time to allow other connections to
649 * deliver missing messages
651 send_destroy (ch, GNUNET_YES);
656 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_buffered_data END\n");
661 * Allow a client to send more data.
663 * In case the client was already allowed to send data, do nothing.
666 * @param fwd Is this a FWD ACK? (FWD ACKs are sent to root)
669 send_client_ack (struct CadetChannel *ch, int fwd)
671 struct CadetChannelReliability *rel = fwd ? ch->root_rel : ch->dest_rel;
672 struct CadetClient *c = fwd ? ch->root : ch->dest;
676 GNUNET_break (GNUNET_NO != ch->destroy);
679 LOG (GNUNET_ERROR_TYPE_DEBUG,
680 " sending %s ack to client on channel %s\n",
681 GC_f2s (fwd), GCCH_2s (ch));
689 if (GNUNET_YES == rel->client_allowed)
691 LOG (GNUNET_ERROR_TYPE_DEBUG, " already allowed\n");
694 rel->client_allowed = GNUNET_YES;
696 GML_send_ack (c, fwd ? ch->lid_root : ch->lid_dest);
701 * Notify the root that the destination rejected the channel.
703 * @param ch Rejected channel.
706 send_client_nack (struct CadetChannel *ch)
708 if (NULL == ch->root)
713 GML_send_channel_nack (ch->root, ch->lid_root);
718 * We haven't received an ACK after a certain time: restransmit the message.
720 * @param cls Closure (CadetChannelReliability with the message to restransmit)
721 * @param tc TaskContext.
724 channel_retransmit_message (void *cls,
725 const struct GNUNET_SCHEDULER_TaskContext *tc)
727 struct CadetChannelReliability *rel = cls;
728 struct CadetReliableMessage *copy;
729 struct CadetChannel *ch;
730 struct GNUNET_CADET_Data *payload;
733 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
734 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
738 copy = rel->head_sent;
745 payload = (struct GNUNET_CADET_Data *) ©[1];
746 fwd = (rel == ch->root_rel);
748 /* Message not found in the queue that we are going to use. */
749 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RETRANSMIT %u\n", copy->mid);
751 GCCH_send_prebuilt_message (&payload->header, ch, fwd, copy);
752 GNUNET_STATISTICS_update (stats, "# data retransmitted", 1, GNUNET_NO);
757 * We haven't received an Channel ACK after a certain time: resend the CREATE.
759 * @param cls Closure (CadetChannelReliability of the channel to recreate)
760 * @param tc TaskContext.
763 channel_recreate (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
765 struct CadetChannelReliability *rel = cls;
767 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
768 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
771 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RE-CREATE\n");
772 GNUNET_STATISTICS_update (stats, "# data retransmitted", 1, GNUNET_NO);
774 if (rel == rel->ch->root_rel)
776 send_create (rel->ch);
778 else if (rel == rel->ch->dest_rel)
780 send_ack (rel->ch, GNUNET_YES, GNUNET_NO);
791 * Message has been sent: start retransmission timer.
793 * @param cls Closure (queue structure).
795 * @param q Queue handler (no longer valid).
796 * @param type Type of message.
797 * @param size Size of the message.
800 ch_message_sent (void *cls,
801 struct CadetTunnel *t,
802 struct CadetTunnelQueue *q,
803 uint16_t type, size_t size)
805 struct CadetChannelQueue *chq = cls;
806 struct CadetReliableMessage *copy = chq->copy;
807 struct CadetChannelReliability *rel;
809 LOG (GNUNET_ERROR_TYPE_DEBUG, "channel message sent callback %s\n",
814 case GNUNET_MESSAGE_TYPE_CADET_DATA:
815 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SENT DATA MID %u\n", copy->mid);
816 GNUNET_assert (chq == copy->chq);
817 copy->timestamp = GNUNET_TIME_absolute_get ();
819 if (GNUNET_SCHEDULER_NO_TASK == rel->retry_task)
821 LOG (GNUNET_ERROR_TYPE_DEBUG, "!! scheduling retry in 4 * %s\n",
822 GNUNET_STRINGS_relative_time_to_string (rel->expected_delay,
824 if (0 != rel->expected_delay.rel_value_us)
826 LOG (GNUNET_ERROR_TYPE_DEBUG, "!! delay != 0\n");
828 GNUNET_TIME_relative_multiply (rel->expected_delay,
829 CADET_RETRANSMIT_MARGIN);
833 LOG (GNUNET_ERROR_TYPE_DEBUG, "!! delay reset\n");
834 rel->retry_timer = CADET_RETRANSMIT_TIME;
836 LOG (GNUNET_ERROR_TYPE_DEBUG, "!! using delay %s\n",
837 GNUNET_STRINGS_relative_time_to_string (rel->retry_timer,
840 GNUNET_SCHEDULER_add_delayed (rel->retry_timer,
841 &channel_retransmit_message, rel);
845 LOG (GNUNET_ERROR_TYPE_DEBUG, "!! retry task %u\n", rel->retry_task);
851 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
852 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
853 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
854 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SENT %s\n", GC_m2s (chq->type));
856 GNUNET_assert (rel->uniq == chq);
859 if (CADET_CHANNEL_READY != rel->ch->state
860 && GNUNET_MESSAGE_TYPE_CADET_DATA_ACK != type
861 && GNUNET_NO == rel->ch->destroy)
863 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == rel->retry_task);
864 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! STD BACKOFF %s\n",
865 GNUNET_STRINGS_relative_time_to_string (rel->retry_timer,
867 rel->retry_timer = GNUNET_TIME_STD_BACKOFF (rel->retry_timer);
868 rel->retry_task = GNUNET_SCHEDULER_add_delayed (rel->retry_timer,
869 &channel_recreate, rel);
882 * send a channel create message.
884 * @param ch Channel for which to send.
887 send_create (struct CadetChannel *ch)
889 struct GNUNET_CADET_ChannelCreate msgcc;
891 msgcc.header.size = htons (sizeof (msgcc));
892 msgcc.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE);
893 msgcc.chid = htonl (ch->gid);
894 msgcc.port = htonl (ch->port);
895 msgcc.opt = htonl (channel_get_options (ch));
897 GCCH_send_prebuilt_message (&msgcc.header, ch, GNUNET_YES, NULL);
902 * Confirm we got a channel create or FWD ack.
904 * @param ch The channel to confirm.
905 * @param fwd Should we send a FWD ACK? (going dest->root)
906 * @param reaction This ACK is a reaction to a duplicate CREATE, don't save.
909 send_ack (struct CadetChannel *ch, int fwd, int reaction)
911 struct GNUNET_CADET_ChannelManage msg;
913 msg.header.size = htons (sizeof (msg));
914 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK);
915 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending channel %s ack for channel %s\n",
916 GC_f2s (fwd), GCCH_2s (ch));
918 msg.chid = htonl (ch->gid);
919 GCCH_send_prebuilt_message (&msg.header, ch, !fwd, reaction ? &msg : NULL);
924 * Send a message and don't keep any info about it: we won't need to cancel it
927 * @param msg Header of the message to fire away.
928 * @param ch Channel on which the message should go.
929 * @param force Is this a forced (undroppable) message?
932 fire_and_forget (const struct GNUNET_MessageHeader *msg,
933 struct CadetChannel *ch,
936 GNUNET_break (NULL == GCT_send_prebuilt_message (msg, ch->t, NULL,
942 * Notify that a channel create didn't succeed.
944 * @param ch The channel to reject.
947 send_nack (struct CadetChannel *ch)
949 struct GNUNET_CADET_ChannelManage msg;
951 msg.header.size = htons (sizeof (msg));
952 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK);
953 LOG (GNUNET_ERROR_TYPE_DEBUG,
954 " sending channel NACK for channel %s\n",
957 msg.chid = htonl (ch->gid);
958 GCCH_send_prebuilt_message (&msg.header, ch, GNUNET_NO, NULL);
963 * Destroy all reliable messages queued for a channel,
964 * during a channel destruction.
965 * Frees the reliability structure itself.
967 * @param rel Reliability data for a channel.
970 channel_rel_free_all (struct CadetChannelReliability *rel)
972 struct CadetReliableMessage *copy;
973 struct CadetReliableMessage *next;
978 for (copy = rel->head_recv; NULL != copy; copy = next)
981 GNUNET_CONTAINER_DLL_remove (rel->head_recv, rel->tail_recv, copy);
982 LOG (GNUNET_ERROR_TYPE_DEBUG, " COPYFREE BATCH RECV %p\n", copy);
983 GNUNET_break (NULL == copy->chq);
986 for (copy = rel->head_sent; NULL != copy; copy = next)
989 GNUNET_CONTAINER_DLL_remove (rel->head_sent, rel->tail_sent, copy);
990 LOG (GNUNET_ERROR_TYPE_DEBUG, " COPYFREE BATCH %p\n", copy);
991 if (NULL != copy->chq)
993 if (NULL != copy->chq->tq)
995 GCT_cancel (copy->chq->tq);
996 /* ch_message_sent will free copy->q */
1000 GNUNET_free (copy->chq);
1006 if (NULL != rel->uniq && NULL != rel->uniq->tq)
1008 GCT_cancel (rel->uniq->tq);
1009 /* ch_message_sent is called freeing uniq */
1011 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
1013 GNUNET_SCHEDULER_cancel (rel->retry_task);
1014 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
1021 * Mark future messages as ACK'd.
1023 * @param rel Reliability data.
1024 * @param msg DataACK message with a bitfield of future ACK'd messages.
1027 channel_rel_free_sent (struct CadetChannelReliability *rel,
1028 const struct GNUNET_CADET_DataACK *msg)
1030 struct CadetReliableMessage *copy;
1031 struct CadetReliableMessage *next;
1038 bitfield = msg->futures;
1039 mid = ntohl (msg->mid);
1040 LOG (GNUNET_ERROR_TYPE_DEBUG, "free_sent_reliable %u %llX\n", mid, bitfield);
1041 LOG (GNUNET_ERROR_TYPE_DEBUG, " rel %p, head %p\n", rel, rel->head_sent);
1042 for (i = 0, copy = rel->head_sent;
1043 i < 64 && NULL != copy && 0 != bitfield;
1046 LOG (GNUNET_ERROR_TYPE_DEBUG, " trying bit %u (mid %u)\n", i, mid + i + 1);
1048 if (0 == (bitfield & mask))
1051 LOG (GNUNET_ERROR_TYPE_DEBUG, " set!\n");
1052 /* Bit was set, clear the bit from the bitfield */
1055 /* The i-th bit was set. Do we have that copy? */
1056 /* Skip copies with mid < target */
1057 target = mid + i + 1;
1058 LOG (GNUNET_ERROR_TYPE_DEBUG, " target %u\n", target);
1059 while (NULL != copy && GC_is_pid_bigger (target, copy->mid))
1062 /* Did we run out of copies? (previously freed, it's ok) */
1065 LOG (GNUNET_ERROR_TYPE_DEBUG, "run out of copies...\n");
1069 /* Did we overshoot the target? (previously freed, it's ok) */
1070 if (GC_is_pid_bigger (copy->mid, target))
1072 LOG (GNUNET_ERROR_TYPE_DEBUG, " next copy %u\n", copy->mid);
1076 /* Now copy->mid == target, free it */
1078 GNUNET_break (GNUNET_YES != rel_message_free (copy, GNUNET_YES));
1081 LOG (GNUNET_ERROR_TYPE_DEBUG, "free_sent_reliable END\n");
1086 * Destroy a reliable message after it has been acknowledged, either by
1087 * direct mid ACK or bitfield. Updates the appropriate data structures and
1088 * timers and frees all memory.
1090 * @param copy Message that is no longer needed: remote peer got it.
1091 * @param update_time Is the timing information relevant?
1092 * If this message is ACK in a batch the timing information
1093 * is skewed by the retransmission, count only for the
1094 * retransmitted message.
1096 * @return #GNUNET_YES if channel was destroyed as a result of the call,
1097 * #GNUNET_NO otherwise.
1100 rel_message_free (struct CadetReliableMessage *copy, int update_time)
1102 struct CadetChannelReliability *rel;
1103 struct GNUNET_TIME_Relative time;
1106 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Freeing %u\n", copy->mid);
1109 time = GNUNET_TIME_absolute_get_duration (copy->timestamp);
1110 if (0 == rel->expected_delay.rel_value_us)
1111 rel->expected_delay = time;
1114 rel->expected_delay.rel_value_us *= 7;
1115 rel->expected_delay.rel_value_us += time.rel_value_us;
1116 rel->expected_delay.rel_value_us /= 8;
1118 LOG (GNUNET_ERROR_TYPE_INFO, "!!! took %s, new delay %s\n",
1119 GNUNET_STRINGS_relative_time_to_string (time, GNUNET_NO),
1120 GNUNET_STRINGS_relative_time_to_string (rel->expected_delay,
1122 rel->retry_timer = rel->expected_delay;
1126 LOG (GNUNET_ERROR_TYPE_INFO, "!!! batch free, ignoring timing\n");
1128 rel->ch->pending_messages--;
1129 if (NULL != copy->chq)
1131 GCT_cancel (copy->chq->tq);
1132 /* copy->q is set to NULL by ch_message_sent */
1134 GNUNET_CONTAINER_DLL_remove (rel->head_sent, rel->tail_sent, copy);
1135 LOG (GNUNET_ERROR_TYPE_DEBUG, " COPYFREE %p\n", copy);
1138 if (GNUNET_NO != rel->ch->destroy && 0 == rel->ch->pending_messages)
1140 GCCH_destroy (rel->ch);
1148 * Channel was ACK'd by remote peer, mark as ready and cancel retransmission.
1150 * @param ch Channel to mark as ready.
1151 * @param fwd Was the ACK message a FWD ACK? (dest->root, SYNACK)
1154 channel_confirm (struct CadetChannel *ch, int fwd)
1156 struct CadetChannelReliability *rel;
1157 enum CadetChannelState oldstate;
1159 rel = fwd ? ch->root_rel : ch->dest_rel;
1162 GNUNET_break (GNUNET_NO != ch->destroy);
1165 LOG (GNUNET_ERROR_TYPE_DEBUG, " channel confirm %s %s\n",
1166 GC_f2s (fwd), GCCH_2s (ch));
1167 oldstate = ch->state;
1168 ch->state = CADET_CHANNEL_READY;
1170 if (CADET_CHANNEL_READY != oldstate || GNUNET_YES == is_loopback (ch))
1172 rel->client_ready = GNUNET_YES;
1173 rel->expected_delay = rel->retry_timer;
1174 LOG (GNUNET_ERROR_TYPE_DEBUG, " !! retry timer confirm %s\n",
1175 GNUNET_STRINGS_relative_time_to_string (rel->retry_timer, GNUNET_NO));
1176 if (GCT_get_connections_buffer (ch->t) > 0 || GCT_is_loopback (ch->t))
1177 send_client_ack (ch, fwd);
1179 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
1181 GNUNET_SCHEDULER_cancel (rel->retry_task);
1182 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
1184 else if (NULL != rel->uniq)
1186 GCT_cancel (rel->uniq->tq);
1187 /* ch_message_sent will free and NULL uniq */
1191 if (GNUNET_NO == is_loopback (ch))
1193 /* We SHOULD have been trying to retransmit this! */
1199 /* In case of a FWD ACK (SYNACK) send a BCK ACK (ACK). */
1200 if (GNUNET_YES == fwd)
1201 send_ack (ch, GNUNET_NO, GNUNET_NO);
1206 * Save a copy to retransmit in case it gets lost.
1208 * Initializes all needed callbacks and timers.
1210 * @param ch Channel this message goes on.
1211 * @param msg Message to copy.
1212 * @param fwd Is this fwd traffic?
1214 static struct CadetReliableMessage *
1215 channel_save_copy (struct CadetChannel *ch,
1216 const struct GNUNET_MessageHeader *msg,
1219 struct CadetChannelReliability *rel;
1220 struct CadetReliableMessage *copy;
1225 rel = fwd ? ch->root_rel : ch->dest_rel;
1226 mid = rel->mid_send - 1;
1227 type = ntohs (msg->type);
1228 size = ntohs (msg->size);
1230 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SAVE %u %s\n", mid, GC_m2s (type));
1231 copy = GNUNET_malloc (sizeof (struct CadetReliableMessage) + size);
1232 LOG (GNUNET_ERROR_TYPE_DEBUG, " at %p\n", copy);
1236 memcpy (©[1], msg, size);
1237 GNUNET_CONTAINER_DLL_insert_tail (rel->head_sent, rel->tail_sent, copy);
1238 ch->pending_messages++;
1245 * Create a new channel.
1247 * @param t Tunnel this channel is in.
1248 * @param owner Client that owns the channel, NULL for foreign channels.
1249 * @param lid_root Local ID for root client.
1251 * @return A new initialized channel. NULL on error.
1253 static struct CadetChannel *
1254 channel_new (struct CadetTunnel *t,
1255 struct CadetClient *owner,
1256 CADET_ChannelNumber lid_root)
1258 struct CadetChannel *ch;
1260 ch = GNUNET_new (struct CadetChannel);
1262 ch->lid_root = lid_root;
1265 GNUNET_STATISTICS_update (stats, "# channels", 1, GNUNET_NO);
1269 ch->gid = GCT_get_next_chid (t);
1270 GML_channel_add (owner, lid_root, ch);
1272 GCT_add_channel (t, ch);
1279 * Handle a loopback message: call the appropriate handler for the message type.
1281 * @param ch Channel this message is on.
1282 * @param msgh Message header.
1283 * @param fwd Is this FWD traffic?
1286 handle_loopback (struct CadetChannel *ch,
1287 const struct GNUNET_MessageHeader *msgh,
1292 type = ntohs (msgh->type);
1293 LOG (GNUNET_ERROR_TYPE_DEBUG,
1294 "Loopback %s %s message!\n",
1295 GC_f2s (fwd), GC_m2s (type));
1299 case GNUNET_MESSAGE_TYPE_CADET_DATA:
1300 /* Don't send hop ACK, wait for client to ACK */
1301 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SEND loopback %u (%u)\n",
1302 ntohl (((struct GNUNET_CADET_Data *) msgh)->mid), ntohs (msgh->size));
1303 GCCH_handle_data (ch, (struct GNUNET_CADET_Data *) msgh, fwd);
1306 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
1307 GCCH_handle_data_ack (ch, (struct GNUNET_CADET_DataACK *) msgh, fwd);
1310 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
1311 GCCH_handle_create (ch->t,
1312 (struct GNUNET_CADET_ChannelCreate *) msgh);
1315 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
1316 GCCH_handle_ack (ch,
1317 (struct GNUNET_CADET_ChannelManage *) msgh,
1321 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
1322 GCCH_handle_nack (ch);
1325 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
1326 GCCH_handle_destroy (ch,
1327 (struct GNUNET_CADET_ChannelManage *) msgh,
1332 GNUNET_break_op (0);
1333 LOG (GNUNET_ERROR_TYPE_DEBUG,
1334 "end-to-end message not known (%u)\n",
1335 ntohs (msgh->type));
1341 /******************************************************************************/
1342 /******************************** API ***********************************/
1343 /******************************************************************************/
1346 * Destroy a channel and free all resources.
1348 * @param ch Channel to destroy.
1351 GCCH_destroy (struct CadetChannel *ch)
1353 struct CadetClient *c;
1354 struct CadetTunnel *t;
1358 if (2 == ch->destroy)
1359 return; /* recursive call */
1362 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying channel %s:%u\n",
1363 GCT_2s (ch->t), ch->gid);
1369 GML_channel_remove (c, ch->lid_root, ch);
1375 GML_channel_remove (c, ch->lid_dest, ch);
1378 channel_rel_free_all (ch->root_rel);
1379 channel_rel_free_all (ch->dest_rel);
1382 GCT_remove_channel (t, ch);
1383 GNUNET_STATISTICS_update (stats, "# channels", -1, GNUNET_NO);
1386 GCT_destroy_if_empty (t);
1391 * Get the channel's public ID.
1393 * @param ch Channel.
1395 * @return ID used to identify the channel with the remote peer.
1398 GCCH_get_id (const struct CadetChannel *ch)
1405 * Get the channel tunnel.
1407 * @param ch Channel to get the tunnel from.
1409 * @return tunnel of the channel.
1411 struct CadetTunnel *
1412 GCCH_get_tunnel (const struct CadetChannel *ch)
1419 * Get free buffer space towards the client on a specific channel.
1421 * @param ch Channel.
1422 * @param fwd Is query about FWD traffic?
1424 * @return Free buffer space [0 - 64]
1427 GCCH_get_buffer (struct CadetChannel *ch, int fwd)
1429 struct CadetChannelReliability *rel;
1431 rel = fwd ? ch->dest_rel : ch->root_rel;
1433 /* If rel is NULL it means that the end is not yet created,
1434 * most probably is a loopback channel at the point of sending
1435 * the ChannelCreate to itself.
1440 return (64 - rel->n_recv);
1445 * Get flow control status of end point: is client allow to send?
1447 * @param ch Channel.
1448 * @param fwd Is query about FWD traffic? (Request root status).
1450 * @return #GNUNET_YES if client is allowed to send us data.
1453 GCCH_get_allowed (struct CadetChannel *ch, int fwd)
1455 struct CadetChannelReliability *rel;
1457 rel = fwd ? ch->root_rel : ch->dest_rel;
1461 /* Probably shutting down: root/dest NULL'ed to mark disconnection */
1462 GNUNET_break (GNUNET_NO != ch->destroy);
1466 return rel->client_allowed;
1471 * Is the root client for this channel on this peer?
1473 * @param ch Channel.
1474 * @param fwd Is this for fwd traffic?
1476 * @return #GNUNET_YES in case it is.
1479 GCCH_is_origin (struct CadetChannel *ch, int fwd)
1481 struct CadetClient *c;
1483 c = fwd ? ch->root : ch->dest;
1489 * Is the destination client for this channel on this peer?
1491 * @param ch Channel.
1492 * @param fwd Is this for fwd traffic?
1494 * @return #GNUNET_YES in case it is.
1497 GCCH_is_terminal (struct CadetChannel *ch, int fwd)
1499 struct CadetClient *c;
1501 c = fwd ? ch->dest : ch->root;
1507 * Send an end-to-end ACK message for the most recent in-sequence payload.
1509 * If channel is not reliable, do nothing.
1511 * @param ch Channel this is about.
1512 * @param fwd Is for FWD traffic? (ACK dest->owner)
1515 GCCH_send_data_ack (struct CadetChannel *ch, int fwd)
1517 struct GNUNET_CADET_DataACK msg;
1518 struct CadetChannelReliability *rel;
1519 struct CadetReliableMessage *copy;
1524 if (GNUNET_NO == ch->reliable)
1527 rel = fwd ? ch->dest_rel : ch->root_rel;
1528 ack = rel->mid_recv - 1;
1530 msg.header.type = htons (GNUNET_MESSAGE_TYPE_CADET_DATA_ACK);
1531 msg.header.size = htons (sizeof (msg));
1532 msg.chid = htonl (ch->gid);
1533 msg.mid = htonl (ack);
1536 for (copy = rel->head_recv; NULL != copy; copy = copy->next)
1538 if (copy->type != GNUNET_MESSAGE_TYPE_CADET_DATA)
1540 LOG (GNUNET_ERROR_TYPE_DEBUG, " Type %s, expected DATA\n",
1541 GC_m2s (copy->type));
1544 GNUNET_assert (copy->mid > ack);
1545 delta = copy->mid - (ack + 1);
1548 mask = 0x1LL << delta;
1549 msg.futures |= mask;
1550 LOG (GNUNET_ERROR_TYPE_DEBUG,
1551 " setting bit for %u (delta %u) (%llX) -> %llX\n",
1552 copy->mid, delta, mask, msg.futures);
1554 LOG (GNUNET_ERROR_TYPE_INFO, "===> DATA_ACK for %u + %llX\n",
1557 GCCH_send_prebuilt_message (&msg.header, ch, !fwd, NULL);
1558 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_data_ack END\n");
1563 * Allow a client to send us more data, in case it was choked.
1565 * @param ch Channel.
1566 * @param fwd Is this about FWD traffic? (Root client).
1569 GCCH_allow_client (struct CadetChannel *ch, int fwd)
1571 struct CadetChannelReliability *rel;
1572 unsigned int buffer;
1574 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMCH allow\n");
1576 if (CADET_CHANNEL_READY != ch->state)
1578 LOG (GNUNET_ERROR_TYPE_DEBUG, " channel not ready yet!\n");
1582 if (GNUNET_YES == ch->reliable)
1584 rel = fwd ? ch->root_rel : ch->dest_rel;
1587 GNUNET_break (GNUNET_NO != ch->destroy);
1590 if (NULL != rel->head_sent)
1592 if (64 <= rel->mid_send - rel->head_sent->mid)
1594 LOG (GNUNET_ERROR_TYPE_DEBUG, " too big MID gap! Wait for ACK.\n");
1599 LOG (GNUNET_ERROR_TYPE_DEBUG, " gap ok: %u - %u\n",
1600 rel->head_sent->mid, rel->mid_send);
1601 struct CadetReliableMessage *aux;
1602 for (aux = rel->head_sent; NULL != aux; aux = aux->next)
1604 LOG (GNUNET_ERROR_TYPE_DEBUG, " - sent MID %u\n", aux->mid);
1610 LOG (GNUNET_ERROR_TYPE_DEBUG, " head sent is NULL\n");
1614 if (is_loopback (ch))
1615 buffer = GCCH_get_buffer (ch, fwd);
1617 buffer = GCT_get_connections_buffer (ch->t);
1621 LOG (GNUNET_ERROR_TYPE_DEBUG, " no buffer space.\n");
1625 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space %u, allowing\n", buffer);
1626 send_client_ack (ch, fwd);
1633 * @param ch Channel.
1636 GCCH_debug (struct CadetChannel *ch)
1640 LOG (GNUNET_ERROR_TYPE_DEBUG, "*** DEBUG NULL CHANNEL ***\n");
1643 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %s:%X (%p)\n",
1644 GCT_2s (ch->t), ch->gid, ch);
1645 LOG (GNUNET_ERROR_TYPE_DEBUG, " root %p/%p\n",
1646 ch->root, ch->root_rel);
1647 if (NULL != ch->root)
1649 LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->root));
1650 LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n",
1651 ch->root_rel->client_ready ? "YES" : "NO");
1652 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_root);
1654 LOG (GNUNET_ERROR_TYPE_DEBUG, " dest %p/%p\n",
1655 ch->dest, ch->dest_rel);
1656 if (NULL != ch->dest)
1658 LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->dest));
1659 LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n",
1660 ch->dest_rel->client_ready ? "YES" : "NO");
1661 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_dest);
1667 * Handle an ACK given by a client.
1669 * Mark client as ready and send him any buffered data we could have for him.
1671 * @param ch Channel.
1672 * @param fwd Is this a "FWD ACK"? (FWD ACKs are sent by dest and go BCK)
1675 GCCH_handle_local_ack (struct CadetChannel *ch, int fwd)
1677 struct CadetChannelReliability *rel;
1678 struct CadetClient *c;
1680 rel = fwd ? ch->dest_rel : ch->root_rel;
1681 c = fwd ? ch->dest : ch->root;
1683 rel->client_ready = GNUNET_YES;
1684 send_client_buffered_data (ch, c, fwd);
1686 if (GNUNET_YES == ch->destroy && 0 == rel->n_recv)
1688 send_destroy (ch, GNUNET_YES);
1691 /* if loopback is marked for destruction, no need to ACK to the other peer,
1692 * it requested the destruction and is already gone, therefore, else if.
1694 else if (is_loopback (ch))
1696 unsigned int buffer;
1698 buffer = GCCH_get_buffer (ch, fwd);
1700 GCCH_allow_client (ch, fwd);
1704 GCT_send_connection_acks (ch->t);
1709 * Handle data given by a client.
1711 * Check whether the client is allowed to send in this tunnel, save if channel
1712 * is reliable and send an ACK to the client if there is still buffer space
1715 * @param ch Channel.
1716 * @param c Client which sent the data.
1717 * @param message Message.
1718 * @param fwd Is this a FWD data?
1720 * @return GNUNET_OK if everything goes well, GNUNET_SYSERR in case of en error.
1723 GCCH_handle_local_data (struct CadetChannel *ch,
1724 struct CadetClient *c,
1725 struct GNUNET_MessageHeader *message,
1728 struct CadetChannelReliability *rel;
1729 struct GNUNET_CADET_Data *payload;
1730 size_t size = ntohs (message->size);
1731 uint16_t p2p_size = sizeof(struct GNUNET_CADET_Data) + size;
1732 unsigned char cbuf[p2p_size];
1734 /* Is the client in the channel? */
1741 GNUNET_break_op (0);
1742 return GNUNET_SYSERR;
1745 rel = fwd ? ch->root_rel : ch->dest_rel;
1747 if (GNUNET_NO == rel->client_allowed)
1749 GNUNET_break_op (0);
1750 return GNUNET_SYSERR;
1753 rel->client_allowed = GNUNET_NO;
1755 /* Ok, everything is correct, send the message. */
1756 payload = (struct GNUNET_CADET_Data *) cbuf;
1757 payload->mid = htonl (rel->mid_send);
1759 memcpy (&payload[1], message, size);
1760 payload->header.size = htons (p2p_size);
1761 payload->header.type = htons (GNUNET_MESSAGE_TYPE_CADET_DATA);
1762 payload->chid = htonl (ch->gid);
1763 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channel...\n");
1764 GCCH_send_prebuilt_message (&payload->header, ch, fwd, NULL);
1766 if (is_loopback (ch))
1768 if (GCCH_get_buffer (ch, fwd) > 0)
1769 GCCH_allow_client (ch, fwd);
1774 if (GCT_get_connections_buffer (ch->t) > 0)
1776 GCCH_allow_client (ch, fwd);
1784 * Handle a channel destroy requested by a client.
1786 * Destroy the channel and the tunnel in case this was the last channel.
1788 * @param ch Channel.
1789 * @param c Client that requested the destruction (to avoid notifying him).
1790 * @param is_root Is the request coming from root?
1793 GCCH_handle_local_destroy (struct CadetChannel *ch,
1794 struct CadetClient *c,
1797 ch->destroy = GNUNET_YES;
1798 /* Cleanup after the tunnel */
1799 if (GNUNET_NO == is_root && c == ch->dest)
1801 LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is destination.\n", GML_2s (c));
1802 GML_client_delete_channel (c, ch, ch->lid_dest);
1805 if (GNUNET_YES == is_root && c == ch->root)
1807 LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is owner.\n", GML_2s (c));
1808 GML_client_delete_channel (c, ch, ch->lid_root);
1812 send_destroy (ch, GNUNET_NO);
1813 if (0 == ch->pending_messages)
1819 * Handle a channel create requested by a client.
1821 * Create the channel and the tunnel in case this was the first0 channel.
1823 * @param c Client that requested the creation (will be the root).
1824 * @param msg Create Channel message.
1826 * @return GNUNET_OK if everything went fine, GNUNET_SYSERR otherwise.
1829 GCCH_handle_local_create (struct CadetClient *c,
1830 struct GNUNET_CADET_ChannelMessage *msg)
1832 struct CadetChannel *ch;
1833 struct CadetTunnel *t;
1834 struct CadetPeer *peer;
1835 CADET_ChannelNumber chid;
1837 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s:%u\n",
1838 GNUNET_i2s (&msg->peer), ntohl (msg->port));
1839 chid = ntohl (msg->channel_id);
1841 /* Sanity check for duplicate channel IDs */
1842 if (NULL != GML_channel_get (c, chid))
1845 return GNUNET_SYSERR;
1848 peer = GCP_get (&msg->peer);
1849 GCP_add_tunnel (peer);
1850 t = GCP_get_tunnel (peer);
1852 if (GCP_get_short_id (peer) == myid)
1854 GCT_change_cstate (t, CADET_TUNNEL_READY);
1858 /* FIXME change to a tunnel API, eliminate ch <-> peer connection */
1862 /* Create channel */
1863 ch = channel_new (t, c, chid);
1867 return GNUNET_SYSERR;
1869 ch->port = ntohl (msg->port);
1870 channel_set_options (ch, ntohl (msg->opt));
1872 /* In unreliable channels, we'll use the DLL to buffer BCK data */
1873 ch->root_rel = GNUNET_new (struct CadetChannelReliability);
1874 ch->root_rel->ch = ch;
1875 ch->root_rel->retry_timer = CADET_RETRANSMIT_TIME;
1876 ch->root_rel->expected_delay.rel_value_us = 0;
1878 LOG (GNUNET_ERROR_TYPE_DEBUG, "CREATED CHANNEL %s\n", GCCH_2s (ch));
1887 * Handler for cadet network payload traffic.
1889 * @param ch Channel for the message.
1890 * @param msg Unencryted data message.
1891 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1892 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1893 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1894 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1897 GCCH_handle_data (struct CadetChannel *ch,
1898 const struct GNUNET_CADET_Data *msg,
1901 struct CadetChannelReliability *rel;
1902 struct CadetClient *c;
1905 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1906 if (GNUNET_SYSERR == fwd)
1908 if (is_loopback (ch))
1910 /* It is a loopback channel after all... */
1914 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1917 /* Initialize FWD/BCK data */
1918 c = fwd ? ch->dest : ch->root;
1919 rel = fwd ? ch->dest_rel : ch->root_rel;
1923 GNUNET_break (GNUNET_NO != ch->destroy);
1927 if (CADET_CHANNEL_READY != ch->state)
1929 if (GNUNET_NO == fwd)
1931 /* If we are the root, this means the other peer has sent traffic before
1932 * receiving our ACK. Even if the SYNACK goes missing, no traffic should
1933 * be sent before the ACK.
1935 GNUNET_break_op (0);
1938 /* If we are the dest, this means that the SYNACK got to the root but
1939 * the ACK went missing. Treat this as an ACK.
1941 channel_confirm (ch, GNUNET_NO);
1944 GNUNET_STATISTICS_update (stats, "# data received", 1, GNUNET_NO);
1946 mid = ntohl (msg->mid);
1947 LOG (GNUNET_ERROR_TYPE_INFO, "<=== DATA %u %s on channel %s\n",
1948 mid, GC_f2s (fwd), GCCH_2s (ch));
1950 if (GNUNET_NO == ch->reliable ||
1951 ( !GC_is_pid_bigger (rel->mid_recv, mid) &&
1952 GC_is_pid_bigger (rel->mid_recv + 64, mid) ) )
1954 LOG (GNUNET_ERROR_TYPE_DEBUG, "RECV %u (%u)\n",
1955 mid, ntohs (msg->header.size));
1956 if (GNUNET_YES == ch->reliable)
1958 /* Is this the exact next expected messasge? */
1959 if (mid == rel->mid_recv)
1961 LOG (GNUNET_ERROR_TYPE_DEBUG, "as expected, sending to client\n");
1962 send_client_data (ch, msg, fwd);
1966 LOG (GNUNET_ERROR_TYPE_DEBUG, "save for later\n");
1967 add_buffered_data (msg, rel);
1972 /* Tunnel is unreliable: send to clients directly */
1973 /* FIXME: accept Out Of Order traffic */
1974 rel->mid_recv = mid + 1;
1975 send_client_data (ch, msg, fwd);
1980 GNUNET_break_op (GC_is_pid_bigger (rel->mid_recv, mid));
1981 LOG (GNUNET_ERROR_TYPE_WARNING,
1982 "MID %u on channel %s not expected (window: %u - %u). Dropping!\n",
1983 mid, GCCH_2s (ch), rel->mid_recv, rel->mid_recv + 63);
1986 GCCH_send_data_ack (ch, fwd);
1991 * Handler for cadet network traffic end-to-end ACKs.
1993 * @param ch Channel on which we got this message.
1994 * @param msg Data message.
1995 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1996 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1997 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1998 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2001 GCCH_handle_data_ack (struct CadetChannel *ch,
2002 const struct GNUNET_CADET_DataACK *msg,
2005 struct CadetChannelReliability *rel;
2006 struct CadetReliableMessage *copy;
2007 struct CadetReliableMessage *next;
2011 /* If this is a remote (non-loopback) channel, find 'fwd'. */
2012 if (GNUNET_SYSERR == fwd)
2014 if (is_loopback (ch))
2016 /* It is a loopback channel after all... */
2020 /* Inverted: if message came 'FWD' is a 'BCK ACK'. */
2021 fwd = (NULL != ch->dest) ? GNUNET_NO : GNUNET_YES;
2024 ack = ntohl (msg->mid);
2025 LOG (GNUNET_ERROR_TYPE_INFO, "<=== %s ACK %u + %llX\n",
2026 GC_f2s (fwd), ack, msg->futures);
2028 if (GNUNET_YES == fwd)
2038 GNUNET_break_op (GNUNET_NO != ch->destroy);
2042 /* Free ACK'd copies: no need to retransmit those anymore FIXME refactor */
2043 for (work = GNUNET_NO, copy = rel->head_sent; copy != NULL; copy = next)
2045 if (GC_is_pid_bigger (copy->mid, ack))
2047 LOG (GNUNET_ERROR_TYPE_DEBUG, " head %u, out!\n", copy->mid);
2048 channel_rel_free_sent (rel, msg);
2052 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %u\n", copy->mid);
2054 if (GNUNET_YES == rel_message_free (copy, GNUNET_YES))
2058 /* ACK client if needed and possible */
2059 GCCH_allow_client (ch, fwd);
2061 /* If some message was free'd, update the retransmission delay */
2062 if (GNUNET_YES == work)
2064 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
2066 GNUNET_SCHEDULER_cancel (rel->retry_task);
2067 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
2068 if (NULL != rel->head_sent && NULL == rel->head_sent->chq)
2070 struct GNUNET_TIME_Absolute new_target;
2071 struct GNUNET_TIME_Relative delay;
2073 delay = GNUNET_TIME_relative_multiply (rel->retry_timer,
2074 CADET_RETRANSMIT_MARGIN);
2075 new_target = GNUNET_TIME_absolute_add (rel->head_sent->timestamp,
2077 delay = GNUNET_TIME_absolute_get_remaining (new_target);
2079 GNUNET_SCHEDULER_add_delayed (delay,
2080 &channel_retransmit_message,
2086 /* Work was done but no task was pending? Shouldn't happen! */
2094 * Handler for channel create messages.
2096 * Does not have fwd parameter because it's always 'FWD': channel is incoming.
2098 * @param t Tunnel this channel will be in.
2099 * @param msg Channel crate message.
2101 struct CadetChannel *
2102 GCCH_handle_create (struct CadetTunnel *t,
2103 const struct GNUNET_CADET_ChannelCreate *msg)
2105 CADET_ChannelNumber chid;
2106 struct CadetChannel *ch;
2107 struct CadetClient *c;
2111 reaction = GNUNET_NO;
2112 chid = ntohl (msg->chid);
2113 ch = GCT_get_channel (t, chid);
2116 /* Create channel */
2117 ch = channel_new (t, NULL, 0);
2119 channel_set_options (ch, ntohl (msg->opt));
2120 new_channel = GNUNET_YES;
2124 new_channel = GNUNET_NO;
2127 if (GNUNET_YES == new_channel || GCT_is_loopback (t))
2129 /* Find a destination client */
2130 ch->port = ntohl (msg->port);
2131 LOG (GNUNET_ERROR_TYPE_DEBUG, " port %u\n", ch->port);
2132 c = GML_client_get_by_port (ch->port);
2135 LOG (GNUNET_ERROR_TYPE_DEBUG, " no client has port registered\n");
2136 if (is_loopback (ch))
2138 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback: destroy on handler\n");
2143 LOG (GNUNET_ERROR_TYPE_DEBUG, " not loopback: destroy now\n");
2151 LOG (GNUNET_ERROR_TYPE_DEBUG, " client %p has port registered\n", c);
2154 add_destination (ch, c);
2155 if (GNUNET_YES == ch->reliable)
2156 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Reliable\n");
2158 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Not Reliable\n");
2160 send_client_create (ch);
2161 ch->state = CADET_CHANNEL_SENT;
2165 LOG (GNUNET_ERROR_TYPE_DEBUG, " duplicate create channel\n");
2166 reaction = GNUNET_YES;
2167 if (GNUNET_SCHEDULER_NO_TASK != ch->dest_rel->retry_task)
2169 LOG (GNUNET_ERROR_TYPE_DEBUG, " clearing retry task\n");
2170 /* we were waiting to re-send our 'SYNACK', wait no more! */
2171 GNUNET_SCHEDULER_cancel (ch->dest_rel->retry_task);
2172 ch->dest_rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
2175 send_ack (ch, GNUNET_YES, reaction);
2182 * Handler for channel NACK messages.
2184 * NACK messages always go dest -> root, no need for 'fwd' or 'msg' parameter.
2186 * @param ch Channel.
2189 GCCH_handle_nack (struct CadetChannel *ch)
2191 send_client_nack (ch);
2197 * Handler for channel ack messages.
2199 * @param ch Channel.
2200 * @param msg Message.
2201 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2202 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2203 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2204 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2207 GCCH_handle_ack (struct CadetChannel *ch,
2208 const struct GNUNET_CADET_ChannelManage *msg,
2211 /* If this is a remote (non-loopback) channel, find 'fwd'. */
2212 if (GNUNET_SYSERR == fwd)
2214 if (is_loopback (ch))
2216 /* It is a loopback channel after all... */
2220 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
2223 channel_confirm (ch, !fwd);
2228 * Handler for channel destroy messages.
2230 * @param ch Channel to be destroyed of.
2231 * @param msg Message.
2232 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2233 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2234 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2235 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2238 GCCH_handle_destroy (struct CadetChannel *ch,
2239 const struct GNUNET_CADET_ChannelManage *msg,
2242 struct CadetChannelReliability *rel;
2244 /* If this is a remote (non-loopback) channel, find 'fwd'. */
2245 if (GNUNET_SYSERR == fwd)
2247 if (is_loopback (ch))
2249 /* It is a loopback channel after all... */
2253 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
2257 if ( (fwd && NULL == ch->dest) || (!fwd && NULL == ch->root) )
2259 /* Not for us (don't destroy twice a half-open loopback channel) */
2263 rel = fwd ? ch->dest_rel : ch->root_rel;
2264 if (0 == rel->n_recv)
2266 send_destroy (ch, GNUNET_YES);
2271 ch->destroy = GNUNET_YES;
2277 * Sends an already built message on a channel.
2279 * If the channel is on a loopback tunnel, notifies the appropriate destination
2282 * On a normal channel passes the message to the tunnel for encryption and
2283 * sending on a connection.
2285 * This function DOES NOT save the message for retransmission.
2287 * @param message Message to send. Function makes a copy of it.
2288 * @param ch Channel on which this message is transmitted.
2289 * @param fwd Is this a fwd message?
2290 * @param existing_copy This is a retransmission, don't save a copy.
2293 GCCH_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2294 struct CadetChannel *ch, int fwd,
2295 void *existing_copy)
2297 struct CadetChannelQueue *chq;
2300 type = ntohs (message->type);
2301 LOG (GNUNET_ERROR_TYPE_INFO, "===> %s %s on channel %s\n",
2302 GC_m2s (type), GC_f2s (fwd), GCCH_2s (ch));
2304 if (GCT_is_loopback (ch->t))
2306 handle_loopback (ch, message, fwd);
2312 struct GNUNET_CADET_Data *payload;
2313 case GNUNET_MESSAGE_TYPE_CADET_DATA:
2315 payload = (struct GNUNET_CADET_Data *) message;
2316 LOG (GNUNET_ERROR_TYPE_INFO, "===> %s %u\n",
2317 GC_m2s (type), ntohl (payload->mid));
2318 if (GNUNET_YES == ch->reliable)
2320 chq = GNUNET_new (struct CadetChannelQueue);
2322 if (NULL == existing_copy)
2323 chq->copy = channel_save_copy (ch, message, fwd);
2326 chq->copy = (struct CadetReliableMessage *) existing_copy;
2327 if (NULL != chq->copy->chq)
2329 /* Last retransmission was queued but not yet sent!
2330 * This retransmission was scheduled by a ch_message_sent which
2331 * followed a very fast RTT, so the tiny delay made the
2332 * retransmission function to execute before the previous
2333 * retransmitted message even had a chance to leave the peer.
2334 * Cancel this message and wait until the pending
2335 * retransmission leaves the peer and ch_message_sent starts
2336 * the timer for the next one.
2339 LOG (GNUNET_ERROR_TYPE_DEBUG,
2340 " exisitng copy not yet transmitted!\n");
2343 LOG (GNUNET_ERROR_TYPE_DEBUG,
2344 " using existing copy: %p {r:%p q:%p t:%u}\n",
2346 chq->copy->rel, chq->copy->chq, chq->copy->type);
2348 LOG (GNUNET_ERROR_TYPE_DEBUG, " new chq: %p\n", chq);
2349 chq->copy->chq = chq;
2350 chq->tq = GCT_send_prebuilt_message (message, ch->t, NULL,
2351 NULL != existing_copy,
2352 &ch_message_sent, chq);
2353 /* q itself is stored in copy */
2354 GNUNET_assert (NULL != chq->tq || GNUNET_NO != ch->destroy);
2358 fire_and_forget (message, ch, GNUNET_NO);
2363 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_ACK:
2364 if (GNUNET_YES == fwd || NULL != existing_copy)
2366 /* BCK ACK (going FWD) is just a response for a SYNACK, don't keep*/
2367 fire_and_forget (message, ch, GNUNET_YES);
2371 case GNUNET_MESSAGE_TYPE_CADET_DATA_ACK:
2372 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE:
2373 chq = GNUNET_new (struct CadetChannelQueue);
2375 chq->rel = fwd ? ch->root_rel : ch->dest_rel;
2376 if (NULL != chq->rel->uniq)
2378 if (NULL != chq->rel->uniq->tq)
2380 GCT_cancel (chq->rel->uniq->tq);
2381 /* ch_message_sent is called, freeing and NULLing uniq */
2386 GNUNET_free (chq->rel->uniq);
2389 chq->tq = GCT_send_prebuilt_message (message, ch->t, NULL, GNUNET_YES,
2390 &ch_message_sent, chq);
2391 if (NULL == chq->tq)
2394 GCT_debug (ch->t, GNUNET_ERROR_TYPE_ERROR);
2399 chq->rel->uniq = chq;
2403 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY:
2404 case GNUNET_MESSAGE_TYPE_CADET_CHANNEL_NACK:
2405 fire_and_forget (message, ch, GNUNET_YES);
2411 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s unknown!\n", GC_m2s (type));
2412 fire_and_forget (message, ch, GNUNET_YES);
2418 * Get the static string for identification of the channel.
2420 * @param ch Channel.
2422 * @return Static string with the channel IDs.
2425 GCCH_2s (const struct CadetChannel *ch)
2427 static char buf[64];
2430 return "(NULL Channel)";
2432 sprintf (buf, "%s:%u gid:%X (%X / %X)",
2433 GCT_2s (ch->t), ch->port, ch->gid, ch->lid_root, ch->lid_dest);