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 "mesh_protocol.h"
30 #include "gnunet-service-mesh_channel.h"
31 #include "gnunet-service-mesh_local.h"
32 #include "gnunet-service-mesh_tunnel.h"
33 #include "gnunet-service-mesh_peer.h"
35 #define LOG(level, ...) GNUNET_log_from(level,"mesh-chn",__VA_ARGS__)
37 #define MESH_RETRANSMIT_TIME GNUNET_TIME_UNIT_SECONDS
38 #define MESH_RETRANSMIT_MARGIN 4
42 * All the states a connection can be in.
47 * Uninitialized status, should never appear in operation.
52 * Connection create message sent, waiting for ACK.
57 * Connection confirmed, ready to carry traffic.
64 * Info holder for channel messages in queues.
66 struct MeshChannelQueue
71 struct MeshTunnel3Queue *q;
74 * Message type (DATA/DATA_ACK)
79 * Message copy (for DATAs, to start retransmission timer)
81 struct MeshReliableMessage *copy;
84 * Reliability (for DATA_ACKs, to access rel->ack_q)
86 struct MeshChannelReliability *rel;
91 * Info needed to retry a message in case it gets lost.
93 struct MeshReliableMessage
96 * Double linked list, FIFO style
98 struct MeshReliableMessage *next;
99 struct MeshReliableMessage *prev;
102 * Type of message (payload, channel management).
107 * Tunnel Reliability queue this message is in.
109 struct MeshChannelReliability *rel;
112 * ID of the message (ACK needed to free)
119 struct MeshChannelQueue *q;
122 * When was this message issued (to calculate ACK delay)
124 struct GNUNET_TIME_Absolute timestamp;
126 /* struct GNUNET_MESH_Data with payload */
131 * Info about the traffic state for a client in a channel.
133 struct MeshChannelReliability
136 * Channel this is about.
138 struct MeshChannel *ch;
141 * DLL of messages sent and not yet ACK'd.
143 struct MeshReliableMessage *head_sent;
144 struct MeshReliableMessage *tail_sent;
147 * DLL of messages received out of order.
149 struct MeshReliableMessage *head_recv;
150 struct MeshReliableMessage *tail_recv;
158 * Next MID to use for outgoing traffic.
163 * Next MID expected for incoming traffic.
168 * Handle for queued unique data CREATE, DATA_ACK.
170 struct MeshChannelQueue *uniq;
173 * Can we send data to the client?
178 * Can the client send data to us?
183 * Task to resend/poll in case no ACK is received.
185 GNUNET_SCHEDULER_TaskIdentifier retry_task;
188 * Counter for exponential backoff.
190 struct GNUNET_TIME_Relative retry_timer;
193 * How long does it usually take to get an ACK.
195 struct GNUNET_TIME_Relative expected_delay;
200 * Struct containing all information regarding a channel to a remote client.
205 * Tunnel this channel is in.
207 struct MeshTunnel3 *t;
210 * Destination port of the channel.
215 * Global channel number ( < GNUNET_MESH_LOCAL_CHANNEL_ID_CLI)
217 MESH_ChannelNumber gid;
220 * Local tunnel number for root (owner) client.
221 * ( >= GNUNET_MESH_LOCAL_CHANNEL_ID_CLI or 0 )
223 MESH_ChannelNumber lid_root;
226 * Local tunnel number for local destination clients (incoming number)
227 * ( >= GNUNET_MESH_LOCAL_CHANNEL_ID_SERV or 0).
229 MESH_ChannelNumber lid_dest;
234 enum MeshChannelState state;
237 * Is the tunnel bufferless (minimum latency)?
242 * Is the tunnel reliable?
247 * Last time the channel was used
249 struct GNUNET_TIME_Absolute timestamp;
252 * Client owner of the tunnel, if any
254 struct MeshClient *root;
257 * Client destination of the tunnel, if any.
259 struct MeshClient *dest;
262 * Flag to signal the destruction of the channel.
263 * If this is set GNUNET_YES the channel will be destroyed
264 * when the queue is empty.
269 * Total (reliable) messages pending ACK for this channel.
271 unsigned int pending_messages;
275 * Only present (non-NULL) at the owner of a tunnel.
277 struct MeshChannelReliability *root_rel;
281 * Only present (non-NULL) at the destination of a tunnel.
283 struct MeshChannelReliability *dest_rel;
288 /******************************************************************************/
289 /******************************* GLOBALS ***********************************/
290 /******************************************************************************/
293 * Global handle to the statistics service.
295 extern struct GNUNET_STATISTICS_Handle *stats;
298 * Local peer own ID (memory efficient handle).
300 extern GNUNET_PEER_Id myid;
303 /******************************************************************************/
304 /******************************** STATIC ***********************************/
305 /******************************************************************************/
308 * Destroy a reliable message after it has been acknowledged, either by
309 * direct mid ACK or bitfield. Updates the appropriate data structures and
310 * timers and frees all memory.
312 * @param copy Message that is no longer needed: remote peer got it.
313 * @param update_time Is the timing information relevant?
314 * If this message is ACK in a batch the timing information
315 * is skewed by the retransmission, count only for the
316 * retransmitted message.
319 rel_message_free (struct MeshReliableMessage *copy, int update_time);
322 * send a channel create message.
324 * @param ch Channel for which to send.
327 send_create (struct MeshChannel *ch);
330 * Confirm we got a channel create, FWD ack.
332 * @param ch The channel to confirm.
333 * @param fwd Should we send a FWD ACK? (going dest->root)
336 send_ack (struct MeshChannel *ch, int fwd);
341 * We have received a message out of order, or the client is not ready.
342 * Buffer it until we receive an ACK from the client or the missing
343 * message from the channel.
345 * @param msg Message to buffer (MUST be of type MESH_DATA).
346 * @param rel Reliability data to the corresponding direction.
349 add_buffered_data (const struct GNUNET_MESH_Data *msg,
350 struct MeshChannelReliability *rel)
352 struct MeshReliableMessage *copy;
353 struct MeshReliableMessage *prev;
357 size = ntohs (msg->header.size);
358 mid = ntohl (msg->mid);
360 LOG (GNUNET_ERROR_TYPE_DEBUG, "add_buffered_data %u\n", mid);
362 copy = GNUNET_malloc (sizeof (*copy) + size);
365 copy->type = GNUNET_MESSAGE_TYPE_MESH_DATA;
366 memcpy (©[1], msg, size);
370 // FIXME do something better than O(n), although n < 64...
371 // FIXME start from the end (most messages are the latest ones)
372 for (prev = rel->head_recv; NULL != prev; prev = prev->next)
374 LOG (GNUNET_ERROR_TYPE_DEBUG, " prev %u\n", prev->mid);
375 if (GM_is_pid_bigger (prev->mid, mid))
377 LOG (GNUNET_ERROR_TYPE_DEBUG, " bingo!\n");
378 GNUNET_CONTAINER_DLL_insert_before (rel->head_recv, rel->tail_recv,
383 LOG (GNUNET_ERROR_TYPE_DEBUG, " insert at tail!\n");
384 GNUNET_CONTAINER_DLL_insert_tail (rel->head_recv, rel->tail_recv, copy);
385 LOG (GNUNET_ERROR_TYPE_DEBUG, "add_buffered_data END\n");
389 * Add a destination client to a channel, initializing all data structures
390 * in the channel and the client.
392 * @param ch Channel to which add the destination.
393 * @param c Client which to add to the channel.
396 add_destination (struct MeshChannel *ch, struct MeshClient *c)
398 if (NULL != ch->dest)
404 /* Assign local id as destination */
405 ch->lid_dest = GML_get_next_chid (c);
407 /* Store in client's hashmap */
408 GML_channel_add (c, ch->lid_dest, ch);
410 GNUNET_break (NULL == ch->dest_rel);
411 ch->dest_rel = GNUNET_new (struct MeshChannelReliability);
412 ch->dest_rel->ch = ch;
413 ch->dest_rel->expected_delay.rel_value_us = 0;
420 * Set options in a channel, extracted from a bit flag field.
422 * @param ch Channel to set options to.
423 * @param options Bit array in host byte order.
426 channel_set_options (struct MeshChannel *ch, uint32_t options)
428 ch->nobuffer = (options & GNUNET_MESH_OPTION_NOBUFFER) != 0 ?
429 GNUNET_YES : GNUNET_NO;
430 ch->reliable = (options & GNUNET_MESH_OPTION_RELIABLE) != 0 ?
431 GNUNET_YES : GNUNET_NO;
436 * Get a bit flag field with the options of a channel.
438 * @param ch Channel to get options from.
440 * @return Bit array in host byte order.
443 channel_get_options (struct MeshChannel *ch)
449 options |= GNUNET_MESH_OPTION_NOBUFFER;
451 options |= GNUNET_MESH_OPTION_RELIABLE;
458 * Notify the destination client that a new incoming channel was created.
460 * @param ch Channel that was created.
463 send_client_create (struct MeshChannel *ch)
467 if (NULL == ch->dest)
471 opt |= GNUNET_YES == ch->reliable ? GNUNET_MESH_OPTION_RELIABLE : 0;
472 opt |= GNUNET_YES == ch->nobuffer ? GNUNET_MESH_OPTION_NOBUFFER : 0;
473 GML_send_channel_create (ch->dest, ch->lid_dest, ch->port, opt,
474 GMT_get_destination (ch->t));
480 * Send data to a client.
482 * If the client is ready, send directly, otherwise buffer while listening
486 * @param msg Message.
487 * @param fwd Is this a fwd (root->dest) message?
490 send_client_data (struct MeshChannel *ch,
491 const struct GNUNET_MESH_Data *msg,
496 if (ch->dest_rel->client_ready)
497 GML_send_data (ch->dest, msg, ch->lid_dest);
499 add_buffered_data (msg, ch->dest_rel);
503 if (ch->root_rel->client_ready)
504 GML_send_data (ch->root, msg, ch->lid_root);
506 add_buffered_data (msg, ch->root_rel);
512 * Send a buffered message to the client, for in order delivery or
513 * as result of client ACK.
515 * @param ch Channel on which to empty the message buffer.
516 * @param c Client to send to.
517 * @param fwd Is this to send FWD data?.
520 send_client_buffered_data (struct MeshChannel *ch,
521 struct MeshClient *c,
524 struct MeshReliableMessage *copy;
525 struct MeshChannelReliability *rel;
527 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_buffered_data\n");
528 rel = fwd ? ch->dest_rel : ch->root_rel;
529 if (GNUNET_NO == rel->client_ready)
531 LOG (GNUNET_ERROR_TYPE_DEBUG, "client not ready\n");
535 copy = rel->head_recv;
536 /* We never buffer channel management messages */
539 if (copy->mid == rel->mid_recv || GNUNET_NO == ch->reliable)
541 struct GNUNET_MESH_Data *msg = (struct GNUNET_MESH_Data *) ©[1];
543 LOG (GNUNET_ERROR_TYPE_DEBUG,
544 " have %u! now expecting %u\n",
545 copy->mid, rel->mid_recv + 1);
546 send_client_data (ch, msg, fwd);
549 GNUNET_CONTAINER_DLL_remove (rel->head_recv, rel->tail_recv, copy);
550 LOG (GNUNET_ERROR_TYPE_DEBUG, " COPYFREE RECV %p\n", copy);
555 LOG (GNUNET_ERROR_TYPE_DEBUG,
556 " reliable && don't have %u, next is %u\n",
562 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_buffered_data END\n");
567 * Allow a client to send more data.
569 * In case the client was already allowed to send data, do nothing.
572 * @param fwd Is this a FWD ACK? (FWD ACKs are sent to root)
575 send_client_ack (struct MeshChannel *ch, int fwd)
577 struct MeshChannelReliability *rel = fwd ? ch->root_rel : ch->dest_rel;
579 LOG (GNUNET_ERROR_TYPE_DEBUG,
580 " sending %s ack to client on channel %s\n",
581 GM_f2s (fwd), GMCH_2s (ch));
589 if (GNUNET_YES == rel->client_allowed)
591 LOG (GNUNET_ERROR_TYPE_DEBUG, " already allowed\n");
594 rel->client_allowed = GNUNET_YES;
596 GML_send_ack (fwd ? ch->root : ch->dest, fwd ? ch->lid_root : ch->lid_dest);
601 * Notify the root that the destination rejected the channel.
603 * @param ch Rejected channel.
606 send_client_nack (struct MeshChannel *ch)
608 if (NULL == ch->root)
613 GML_send_nack (ch->root, ch->lid_root);
618 * We haven't received an ACK after a certain time: restransmit the message.
620 * @param cls Closure (MeshChannelReliability with the message to restransmit)
621 * @param tc TaskContext.
624 channel_retransmit_message (void *cls,
625 const struct GNUNET_SCHEDULER_TaskContext *tc)
627 struct MeshChannelReliability *rel = cls;
628 struct MeshReliableMessage *copy;
629 struct MeshChannel *ch;
630 struct GNUNET_MESH_Data *payload;
633 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
634 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
638 copy = rel->head_sent;
645 payload = (struct GNUNET_MESH_Data *) ©[1];
646 fwd = (rel == ch->root_rel);
648 /* Message not found in the queue that we are going to use. */
649 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RETRANSMIT %u\n", copy->mid);
651 GMCH_send_prebuilt_message (&payload->header, ch, fwd, copy);
652 GNUNET_STATISTICS_update (stats, "# data retransmitted", 1, GNUNET_NO);
657 * We haven't received an Channel ACK after a certain time: resend the CREATE.
659 * @param cls Closure (MeshChannelReliability of the channel to recreate)
660 * @param tc TaskContext.
663 channel_recreate (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
665 struct MeshChannelReliability *rel = cls;
667 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
668 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
671 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RE-CREATE\n");
672 GNUNET_STATISTICS_update (stats, "# data retransmitted", 1, GNUNET_NO);
674 if (rel == rel->ch->root_rel)
676 send_create (rel->ch);
678 else if (rel == rel->ch->dest_rel)
680 send_ack (rel->ch, GNUNET_YES);
691 * Message has been sent: start retransmission timer.
693 * @param cls Closure (queue structure).
695 * @param q Queue handler (no longer valid).
696 * @param type Type of message.
697 * @param size Size of the message.
700 ch_message_sent (void *cls,
701 struct MeshTunnel3 *t,
702 struct MeshTunnel3Queue *q,
703 uint16_t type, size_t size)
705 struct MeshChannelQueue *ch_q = cls;
706 struct MeshReliableMessage *copy = ch_q->copy;
707 struct MeshChannelReliability *rel;
711 case GNUNET_MESSAGE_TYPE_MESH_DATA:
712 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SENT %u %s (c: %p, q: %p)\n",
713 copy->mid, GM_m2s (type), copy, copy->q);
714 GNUNET_assert (ch_q == copy->q);
715 copy->timestamp = GNUNET_TIME_absolute_get ();
717 if (GNUNET_SCHEDULER_NO_TASK == rel->retry_task)
719 if (0 != rel->expected_delay.rel_value_us)
722 GNUNET_TIME_relative_multiply (rel->expected_delay,
723 MESH_RETRANSMIT_MARGIN);
727 rel->retry_timer = MESH_RETRANSMIT_TIME;
730 GNUNET_SCHEDULER_add_delayed (rel->retry_timer,
731 &channel_retransmit_message, rel);
737 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
738 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
739 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
740 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SENT %s\n", GM_m2s (type));
742 GNUNET_assert (rel->uniq == ch_q);
745 if (MESH_CHANNEL_READY != rel->ch->state
746 && GNUNET_MESSAGE_TYPE_MESH_DATA_ACK != type)
748 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == rel->retry_task);
749 rel->retry_timer = GNUNET_TIME_STD_BACKOFF (rel->retry_timer);
750 rel->retry_task = GNUNET_SCHEDULER_add_delayed (rel->retry_timer,
751 &channel_recreate, rel);
765 * send a channel create message.
767 * @param ch Channel for which to send.
770 send_create (struct MeshChannel *ch)
772 struct GNUNET_MESH_ChannelCreate msgcc;
774 msgcc.header.size = htons (sizeof (msgcc));
775 msgcc.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE);
776 msgcc.chid = htonl (ch->gid);
777 msgcc.port = htonl (ch->port);
778 msgcc.opt = htonl (channel_get_options (ch));
780 GMCH_send_prebuilt_message (&msgcc.header, ch, GNUNET_YES, NULL);
785 * Confirm we got a channel create, FWD ack.
787 * @param ch The channel to confirm.
788 * @param fwd Should we send a FWD ACK? (going dest->root)
791 send_ack (struct MeshChannel *ch, int fwd)
793 struct GNUNET_MESH_ChannelManage msg;
795 msg.header.size = htons (sizeof (msg));
796 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK);
797 LOG (GNUNET_ERROR_TYPE_DEBUG,
798 " sending channel %s ack for channel %s\n",
799 GM_f2s (fwd), GMCH_2s (ch));
801 msg.chid = htonl (ch->gid);
802 GMCH_send_prebuilt_message (&msg.header, ch, !fwd, NULL);
807 * Sent a message and don't keep any info about it: we won't need to cancel it
810 * @param msg Header of the message to fire away.
811 * @param ch Channel on which the message should go.
812 * @param force Is this a forced (undroppable) message?
815 fire_and_forget (const struct GNUNET_MessageHeader *msg,
816 struct MeshChannel *ch,
819 GNUNET_break (NULL == GMT_send_prebuilt_message (msg, ch->t, ch, force,
825 * Notify that a channel create didn't succeed.
827 * @param ch The channel to reject.
830 send_nack (struct MeshChannel *ch)
832 struct GNUNET_MESH_ChannelManage msg;
834 msg.header.size = htons (sizeof (msg));
835 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK);
836 LOG (GNUNET_ERROR_TYPE_DEBUG,
837 " sending channel NACK for channel %s\n",
840 msg.chid = htonl (ch->gid);
841 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_NO, NULL);
846 * Notify a client that the channel is no longer valid.
848 * @param ch Channel that is destroyed.
849 * @param local_only Should we avoid sending it to other peers?
852 send_destroy (struct MeshChannel *ch, int local_only)
854 struct GNUNET_MESH_ChannelManage msg;
856 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY);
857 msg.header.size = htons (sizeof (msg));
858 msg.chid = htonl (ch->gid);
860 /* If root is not NULL, notify.
861 * If it's NULL, check lid_root. When a local destroy comes in, root
862 * is set to NULL but lid_root is left untouched. In this case, do nothing,
863 * the client is the one who reuqested the channel to be destroyed.
865 if (NULL != ch->root)
866 GML_send_channel_destroy (ch->root, ch->lid_root);
867 else if (0 == ch->lid_root && GNUNET_NO == local_only)
868 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_NO, NULL);
870 if (NULL != ch->dest)
871 GML_send_channel_destroy (ch->dest, ch->lid_dest);
872 else if (0 == ch->lid_dest && GNUNET_NO == local_only)
873 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_YES, NULL);
878 * Destroy all reliable messages queued for a channel,
879 * during a channel destruction.
880 * Frees the reliability structure itself.
882 * @param rel Reliability data for a channel.
885 channel_rel_free_all (struct MeshChannelReliability *rel)
887 struct MeshReliableMessage *copy;
888 struct MeshReliableMessage *next;
893 for (copy = rel->head_recv; NULL != copy; copy = next)
896 GNUNET_CONTAINER_DLL_remove (rel->head_recv, rel->tail_recv, copy);
897 LOG (GNUNET_ERROR_TYPE_DEBUG, " COPYFREE BATCH RECV %p\n", copy);
900 for (copy = rel->head_sent; NULL != copy; copy = next)
903 GNUNET_CONTAINER_DLL_remove (rel->head_sent, rel->tail_sent, copy);
904 LOG (GNUNET_ERROR_TYPE_DEBUG, " COPYFREE BATCH %p\n", copy);
907 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
909 GNUNET_SCHEDULER_cancel (rel->retry_task);
911 if (NULL != rel->uniq)
912 GMT_cancel (rel->uniq->q);
918 * Mark future messages as ACK'd.
920 * @param rel Reliability data.
921 * @param msg DataACK message with a bitfield of future ACK'd messages.
924 channel_rel_free_sent (struct MeshChannelReliability *rel,
925 const struct GNUNET_MESH_DataACK *msg)
927 struct MeshReliableMessage *copy;
928 struct MeshReliableMessage *next;
935 bitfield = msg->futures;
936 mid = ntohl (msg->mid);
937 LOG (GNUNET_ERROR_TYPE_DEBUG,
938 "!!! free_sent_reliable %u %llX\n",
940 LOG (GNUNET_ERROR_TYPE_DEBUG,
941 " rel %p, head %p\n",
942 rel, rel->head_sent);
943 for (i = 0, copy = rel->head_sent;
944 i < 64 && NULL != copy && 0 != bitfield;
947 LOG (GNUNET_ERROR_TYPE_DEBUG,
948 " trying bit %u (mid %u)\n",
951 if (0 == (bitfield & mask))
954 LOG (GNUNET_ERROR_TYPE_DEBUG, " set!\n");
955 /* Bit was set, clear the bit from the bitfield */
958 /* The i-th bit was set. Do we have that copy? */
959 /* Skip copies with mid < target */
960 target = mid + i + 1;
961 LOG (GNUNET_ERROR_TYPE_DEBUG, " target %u\n", target);
962 while (NULL != copy && GM_is_pid_bigger (target, copy->mid))
965 /* Did we run out of copies? (previously freed, it's ok) */
968 LOG (GNUNET_ERROR_TYPE_DEBUG, "run out of copies...\n");
972 /* Did we overshoot the target? (previously freed, it's ok) */
973 if (GM_is_pid_bigger (copy->mid, target))
975 LOG (GNUNET_ERROR_TYPE_DEBUG, " next copy %u\n", copy->mid);
979 /* Now copy->mid == target, free it */
981 rel_message_free (copy, GNUNET_YES);
984 LOG (GNUNET_ERROR_TYPE_DEBUG, "free_sent_reliable END\n");
989 * Destroy a reliable message after it has been acknowledged, either by
990 * direct mid ACK or bitfield. Updates the appropriate data structures and
991 * timers and frees all memory.
993 * @param copy Message that is no longer needed: remote peer got it.
994 * @param update_time Is the timing information relevant?
995 * If this message is ACK in a batch the timing information
996 * is skewed by the retransmission, count only for the
997 * retransmitted message.
1000 rel_message_free (struct MeshReliableMessage *copy, int update_time)
1002 struct MeshChannelReliability *rel;
1003 struct GNUNET_TIME_Relative time;
1006 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Freeing %u\n", copy->mid);
1009 time = GNUNET_TIME_absolute_get_duration (copy->timestamp);
1010 if (0 == rel->expected_delay.rel_value_us)
1011 rel->expected_delay = time;
1014 rel->expected_delay.rel_value_us *= 7;
1015 rel->expected_delay.rel_value_us += time.rel_value_us;
1016 rel->expected_delay.rel_value_us /= 8;
1018 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! took %s\n",
1019 GNUNET_STRINGS_relative_time_to_string (time, GNUNET_NO));
1020 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! new expected delay %s\n",
1021 GNUNET_STRINGS_relative_time_to_string (rel->expected_delay,
1023 rel->retry_timer = rel->expected_delay;
1027 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! batch free, ignoring timing\n");
1029 rel->ch->pending_messages--;
1030 if (GNUNET_NO != rel->ch->destroy && 0 == rel->ch->pending_messages)
1032 struct MeshTunnel3 *t = rel->ch->t;
1033 GMCH_destroy (rel->ch);
1034 GMT_destroy_if_empty (t);
1036 if (NULL != copy->q)
1038 GMT_cancel (copy->q->q);
1040 GNUNET_CONTAINER_DLL_remove (rel->head_sent, rel->tail_sent, copy);
1041 LOG (GNUNET_ERROR_TYPE_DEBUG, " COPYFREE %p\n", copy);
1047 * Channel was ACK'd by remote peer, mark as ready and cancel retransmission.
1049 * @param ch Channel to mark as ready.
1050 * @param fwd Was the ACK message a FWD ACK? (dest->root, SYNACK)
1053 channel_confirm (struct MeshChannel *ch, int fwd)
1055 struct MeshChannelReliability *rel;
1056 enum MeshChannelState oldstate;
1058 LOG (GNUNET_ERROR_TYPE_DEBUG,
1059 " channel confirm %s %s:%X\n",
1060 GM_f2s (fwd), GMT_2s (ch->t), ch->gid);
1061 oldstate = ch->state;
1062 ch->state = MESH_CHANNEL_READY;
1064 rel = fwd ? ch->root_rel : ch->dest_rel;
1065 rel->client_ready = GNUNET_YES;
1066 rel->expected_delay = rel->retry_timer;
1067 send_client_ack (ch, fwd);
1069 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
1071 GNUNET_SCHEDULER_cancel (rel->retry_task);
1072 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
1074 else if (NULL != rel->uniq)
1076 GMT_cancel (rel->uniq->q);
1077 /* ch_sent_message will free and NULL uniq */
1081 /* We SHOULD have been trying to retransmit this! */
1082 GNUNET_break (oldstate == MESH_CHANNEL_READY);
1085 /* In case of a FWD ACK (SYNACK) send a BCK ACK (ACK). */
1086 if (GNUNET_YES == fwd)
1087 send_ack (ch, GNUNET_NO);
1092 * Save a copy to retransmit in case it gets lost.
1094 * Initializes all needed callbacks and timers.
1096 * @param ch Channel this message goes on.
1097 * @param msg Message to copy.
1098 * @param fwd Is this fwd traffic?
1100 static struct MeshReliableMessage *
1101 channel_save_copy (struct MeshChannel *ch,
1102 const struct GNUNET_MessageHeader *msg,
1105 struct MeshChannelReliability *rel;
1106 struct MeshReliableMessage *copy;
1111 rel = fwd ? ch->root_rel : ch->dest_rel;
1112 mid = rel->mid_send - 1;
1113 type = ntohs (msg->type);
1114 size = ntohs (msg->size);
1116 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SAVE %u %s\n", mid, GM_m2s (type));
1117 copy = GNUNET_malloc (sizeof (struct MeshReliableMessage) + size);
1118 LOG (GNUNET_ERROR_TYPE_DEBUG, " at %p\n", copy);
1122 memcpy (©[1], msg, size);
1123 GNUNET_CONTAINER_DLL_insert_tail (rel->head_sent, rel->tail_sent, copy);
1124 ch->pending_messages++;
1131 * Create a new channel.
1133 * @param t Tunnel this channel is in.
1134 * @param owner Client that owns the channel, NULL for foreign channels.
1135 * @param lid_root Local ID for root client.
1137 * @return A new initialized channel. NULL on error.
1139 static struct MeshChannel *
1140 channel_new (struct MeshTunnel3 *t,
1141 struct MeshClient *owner,
1142 MESH_ChannelNumber lid_root)
1144 struct MeshChannel *ch;
1146 ch = GNUNET_new (struct MeshChannel);
1148 ch->lid_root = lid_root;
1151 GNUNET_STATISTICS_update (stats, "# channels", 1, GNUNET_NO);
1155 ch->gid = GMT_get_next_chid (t);
1156 GML_channel_add (owner, lid_root, ch);
1158 GMT_add_channel (t, ch);
1165 * Test if the channel is loopback: both root and dest are on the local peer.
1167 * @param ch Channel to test.
1169 * @return #GNUNET_YES if channel is loopback, #NGUNET_NO otherwise.
1172 is_loopback (const struct MeshChannel *ch)
1175 return GMT_is_loopback (ch->t);
1177 return (NULL != ch->root && NULL != ch->dest);
1182 * Handle a loopback message: call the appropriate handler for the message type.
1184 * @param ch Channel this message is on.
1185 * @param msgh Message header.
1186 * @param fwd Is this FWD traffic?
1189 handle_loopback (struct MeshChannel *ch,
1190 const struct GNUNET_MessageHeader *msgh,
1195 type = ntohs (msgh->type);
1196 LOG (GNUNET_ERROR_TYPE_DEBUG,
1197 "Loopback %s %s message!\n",
1198 GM_f2s (fwd), GM_m2s (type));
1202 case GNUNET_MESSAGE_TYPE_MESH_DATA:
1203 /* Don't send hop ACK, wait for client to ACK */
1204 GMCH_handle_data (ch, (struct GNUNET_MESH_Data *) msgh, fwd);
1207 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
1208 GMCH_handle_data_ack (ch, (struct GNUNET_MESH_DataACK *) msgh, fwd);
1211 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
1212 GMCH_handle_create (ch->t,
1213 (struct GNUNET_MESH_ChannelCreate *) msgh);
1216 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
1217 GMCH_handle_ack (ch,
1218 (struct GNUNET_MESH_ChannelManage *) msgh,
1222 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK:
1223 GMCH_handle_nack (ch);
1226 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
1227 GMCH_handle_destroy (ch,
1228 (struct GNUNET_MESH_ChannelManage *) msgh,
1233 GNUNET_break_op (0);
1234 LOG (GNUNET_ERROR_TYPE_DEBUG,
1235 "end-to-end message not known (%u)\n",
1236 ntohs (msgh->type));
1242 /******************************************************************************/
1243 /******************************** API ***********************************/
1244 /******************************************************************************/
1247 * Destroy a channel and free all resources.
1249 * @param ch Channel to destroy.
1252 GMCH_destroy (struct MeshChannel *ch)
1254 struct MeshClient *c;
1259 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying channel %s:%u\n",
1260 GMT_2s (ch->t), ch->gid);
1266 GML_channel_remove (c, ch->lid_root, ch);
1272 GML_channel_remove (c, ch->lid_dest, ch);
1275 channel_rel_free_all (ch->root_rel);
1276 channel_rel_free_all (ch->dest_rel);
1278 GMT_remove_channel (ch->t, ch);
1279 GNUNET_STATISTICS_update (stats, "# channels", -1, GNUNET_NO);
1288 * @param ch Channel.
1293 GMCH_get_id (const struct MeshChannel *ch)
1300 * Get the channel tunnel.
1302 * @param ch Channel to get the tunnel from.
1304 * @return tunnel of the channel.
1306 struct MeshTunnel3 *
1307 GMCH_get_tunnel (const struct MeshChannel *ch)
1314 * Get free buffer space towards the client on a specific channel.
1316 * @param ch Channel.
1317 * @param fwd Is query about FWD traffic?
1319 * @return Free buffer space [0 - 64]
1322 GMCH_get_buffer (struct MeshChannel *ch, int fwd)
1324 struct MeshChannelReliability *rel;
1326 rel = fwd ? ch->dest_rel : ch->root_rel;
1328 /* If rel is NULL it means that the end is not yet created,
1329 * most probably is a loopback channel at the point of sending
1330 * the ChannelCreate to itself.
1335 return (64 - rel->n_recv);
1340 * Get flow control status of end point: is client allow to send?
1342 * @param ch Channel.
1343 * @param fwd Is query about FWD traffic? (Request root status).
1345 * @return #GNUNET_YES if client is allowed to send us data.
1348 GMCH_get_allowed (struct MeshChannel *ch, int fwd)
1350 struct MeshChannelReliability *rel;
1352 rel = fwd ? ch->root_rel : ch->dest_rel;
1356 /* Probably shutting down: root/dest NULL'ed to mark disconnection */
1357 GNUNET_break (GNUNET_NO != ch->destroy);
1361 return rel->client_allowed;
1366 * Is the root client for this channel on this peer?
1368 * @param ch Channel.
1369 * @param fwd Is this for fwd traffic?
1371 * @return #GNUNET_YES in case it is.
1374 GMCH_is_origin (struct MeshChannel *ch, int fwd)
1376 struct MeshClient *c;
1378 c = fwd ? ch->root : ch->dest;
1384 * Is the destination client for this channel on this peer?
1386 * @param ch Channel.
1387 * @param fwd Is this for fwd traffic?
1389 * @return #GNUNET_YES in case it is.
1392 GMCH_is_terminal (struct MeshChannel *ch, int fwd)
1394 struct MeshClient *c;
1396 c = fwd ? ch->dest : ch->root;
1402 * Send an end-to-end ACK message for the most recent in-sequence payload.
1404 * If channel is not reliable, do nothing.
1406 * @param ch Channel this is about.
1407 * @param fwd Is for FWD traffic? (ACK dest->owner)
1410 GMCH_send_data_ack (struct MeshChannel *ch, int fwd)
1412 struct GNUNET_MESH_DataACK msg;
1413 struct MeshChannelReliability *rel;
1414 struct MeshReliableMessage *copy;
1419 if (GNUNET_NO == ch->reliable)
1423 rel = fwd ? ch->dest_rel : ch->root_rel;
1424 ack = rel->mid_recv - 1;
1425 LOG (GNUNET_ERROR_TYPE_DEBUG,
1426 " !! Send DATA_ACK for %u\n",
1429 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_DATA_ACK);
1430 msg.header.size = htons (sizeof (msg));
1431 msg.chid = htonl (ch->gid);
1433 for (copy = rel->head_recv; NULL != copy; copy = copy->next)
1435 if (copy->type != GNUNET_MESSAGE_TYPE_MESH_DATA)
1437 LOG (GNUNET_ERROR_TYPE_DEBUG,
1438 "!! Type %s, expected DATA\n",
1439 GM_m2s (copy->type));
1442 if (copy->mid == ack + 1)
1447 delta = copy->mid - (ack + 1);
1450 mask = 0x1LL << delta;
1451 msg.futures |= mask;
1452 LOG (GNUNET_ERROR_TYPE_DEBUG,
1453 " !! setting bit for %u (delta %u) (%llX) -> %llX\n",
1454 copy->mid, delta, mask, msg.futures);
1456 msg.mid = htonl (ack);
1457 LOG (GNUNET_ERROR_TYPE_DEBUG,
1458 "!!! ACK for %u, futures %llX\n",
1461 GMCH_send_prebuilt_message (&msg.header, ch, !fwd, NULL);
1462 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_data_ack END\n");
1467 * Allow a client to send us more data, in case it was choked.
1469 * @param ch Channel.
1470 * @param fwd Is this about FWD traffic? (Root client).
1473 GMCH_allow_client (struct MeshChannel *ch, int fwd)
1475 struct MeshChannelReliability *rel;
1476 unsigned int buffer;
1478 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMCH allow\n");
1480 if (MESH_CHANNEL_READY != ch->state)
1482 LOG (GNUNET_ERROR_TYPE_DEBUG, " channel not ready yet!\n");
1486 if (GNUNET_YES == ch->reliable)
1488 rel = fwd ? ch->root_rel : ch->dest_rel;
1491 GNUNET_break (GNUNET_NO != ch->destroy);
1494 if (NULL != rel->head_sent && 64 <= rel->mid_send - rel->head_sent->mid)
1496 LOG (GNUNET_ERROR_TYPE_DEBUG, " too big MID gap! Wait for ACK.\n");
1501 if (is_loopback (ch))
1502 buffer = GMCH_get_buffer (ch, fwd);
1504 buffer = GMT_get_connections_buffer (ch->t);
1508 LOG (GNUNET_ERROR_TYPE_DEBUG, " no buffer space.\n");
1512 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space %u, allowing\n", buffer);
1513 send_client_ack (ch, fwd);
1520 * @param ch Channel.
1523 GMCH_debug (struct MeshChannel *ch)
1527 LOG (GNUNET_ERROR_TYPE_DEBUG, "*** DEBUG NULL CHANNEL ***\n");
1530 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %s:%X (%p)\n",
1531 GMT_2s (ch->t), ch->gid, ch);
1532 LOG (GNUNET_ERROR_TYPE_DEBUG, " root %p/%p\n",
1533 ch->root, ch->root_rel);
1534 if (NULL != ch->root)
1536 LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->root));
1537 LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n",
1538 ch->root_rel->client_ready ? "YES" : "NO");
1539 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_root);
1541 LOG (GNUNET_ERROR_TYPE_DEBUG, " dest %p/%p\n",
1542 ch->dest, ch->dest_rel);
1543 if (NULL != ch->dest)
1545 LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->dest));
1546 LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n",
1547 ch->dest_rel->client_ready ? "YES" : "NO");
1548 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_dest);
1554 * Handle an ACK given by a client.
1556 * Mark client as ready and send him any buffered data we could have for him.
1558 * @param ch Channel.
1559 * @param fwd Is this a "FWD ACK"? (FWD ACKs are sent by dest and go BCK)
1562 GMCH_handle_local_ack (struct MeshChannel *ch, int fwd)
1564 struct MeshChannelReliability *rel;
1565 struct MeshClient *c;
1567 rel = fwd ? ch->dest_rel : ch->root_rel;
1568 c = fwd ? ch->dest : ch->root;
1570 rel->client_ready = GNUNET_YES;
1571 send_client_buffered_data (ch, c, fwd);
1572 if (is_loopback (ch))
1574 unsigned int buffer;
1576 buffer = GMCH_get_buffer (ch, fwd);
1578 GMCH_allow_client (ch, fwd);
1582 GMT_send_connection_acks (ch->t);
1587 * Handle data given by a client.
1589 * Check whether the client is allowed to send in this tunnel, save if channel
1590 * is reliable and send an ACK to the client if there is still buffer space
1593 * @param ch Channel.
1594 * @param c Client which sent the data.
1595 * @param message Message.
1596 * @param fwd Is this a FWD data?
1598 * @return GNUNET_OK if everything goes well, GNUNET_SYSERR in case of en error.
1601 GMCH_handle_local_data (struct MeshChannel *ch,
1602 struct MeshClient *c,
1603 struct GNUNET_MessageHeader *message,
1606 struct MeshChannelReliability *rel;
1607 struct GNUNET_MESH_Data *payload;
1608 size_t size = ntohs (message->size);
1609 uint16_t p2p_size = sizeof(struct GNUNET_MESH_Data) + size;
1610 unsigned char cbuf[p2p_size];
1612 /* Is the client in the channel? */
1619 GNUNET_break_op (0);
1620 return GNUNET_SYSERR;
1623 rel = fwd ? ch->root_rel : ch->dest_rel;
1625 if (GNUNET_NO == rel->client_allowed)
1627 GNUNET_break_op (0);
1628 return GNUNET_SYSERR;
1631 rel->client_allowed = GNUNET_NO;
1633 /* Ok, everything is correct, send the message. */
1634 payload = (struct GNUNET_MESH_Data *) cbuf;
1635 payload->mid = htonl (rel->mid_send);
1637 memcpy (&payload[1], message, size);
1638 payload->header.size = htons (p2p_size);
1639 payload->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_DATA);
1640 payload->chid = htonl (ch->gid);
1641 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channel...\n");
1642 GMCH_send_prebuilt_message (&payload->header, ch, fwd, NULL);
1644 if (is_loopback (ch))
1646 if (GMCH_get_buffer (ch, fwd) > 0)
1647 send_client_ack (ch, fwd);
1652 if (GMT_get_connections_buffer (ch->t) > 0)
1654 send_client_ack (ch, fwd);
1662 * Handle a channel destroy requested by a client.
1664 * Destroy the channel and the tunnel in case this was the last channel.
1666 * @param ch Channel.
1667 * @param c Client that requested the destruction (to avoid notifying him).
1668 * @param is_root Is the request coming from root?
1671 GMCH_handle_local_destroy (struct MeshChannel *ch,
1672 struct MeshClient *c,
1675 struct MeshTunnel3 *t;
1677 ch->destroy = GNUNET_YES;
1678 /* Cleanup after the tunnel */
1679 if (GNUNET_NO == is_root && c == ch->dest)
1681 LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is destination.\n", GML_2s (c));
1682 GML_client_delete_channel (c, ch, ch->lid_dest);
1685 if (GNUNET_YES == is_root && c == ch->root)
1687 LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is owner.\n", GML_2s (c));
1688 GML_client_delete_channel (c, ch, ch->lid_root);
1693 send_destroy (ch, GNUNET_NO);
1694 if (0 == ch->pending_messages)
1697 GMT_destroy_if_empty (t);
1703 * Handle a channel create requested by a client.
1705 * Create the channel and the tunnel in case this was the first0 channel.
1707 * @param c Client that requested the creation (will be the root).
1708 * @param msg Create Channel message.
1710 * @return GNUNET_OK if everything went fine, GNUNET_SYSERR otherwise.
1713 GMCH_handle_local_create (struct MeshClient *c,
1714 struct GNUNET_MESH_ChannelMessage *msg)
1716 struct MeshChannel *ch;
1717 struct MeshTunnel3 *t;
1718 struct MeshPeer *peer;
1719 MESH_ChannelNumber chid;
1721 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s:%u\n",
1722 GNUNET_i2s (&msg->peer), ntohl (msg->port));
1723 chid = ntohl (msg->channel_id);
1725 /* Sanity check for duplicate channel IDs */
1726 if (NULL != GML_channel_get (c, chid))
1729 return GNUNET_SYSERR;
1732 peer = GMP_get (&msg->peer);
1733 GMP_add_tunnel (peer);
1734 t = GMP_get_tunnel (peer);
1736 if (GMP_get_short_id (peer) == myid)
1738 GMT_change_cstate (t, MESH_TUNNEL3_READY);
1745 /* Create channel */
1746 ch = channel_new (t, c, chid);
1750 return GNUNET_SYSERR;
1752 ch->port = ntohl (msg->port);
1753 channel_set_options (ch, ntohl (msg->opt));
1755 /* In unreliable channels, we'll use the DLL to buffer BCK data */
1756 ch->root_rel = GNUNET_new (struct MeshChannelReliability);
1757 ch->root_rel->ch = ch;
1758 ch->root_rel->retry_timer = GNUNET_TIME_UNIT_SECONDS;
1759 ch->root_rel->expected_delay.rel_value_us = 0;
1761 LOG (GNUNET_ERROR_TYPE_DEBUG, "CREATED CHANNEL %s\n", GMCH_2s (ch));
1770 * Handler for mesh network payload traffic.
1772 * @param ch Channel for the message.
1773 * @param msg Unencryted data message.
1774 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1775 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1776 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1777 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1780 GMCH_handle_data (struct MeshChannel *ch,
1781 const struct GNUNET_MESH_Data *msg,
1784 struct MeshChannelReliability *rel;
1785 struct MeshClient *c;
1788 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1789 if (GNUNET_SYSERR == fwd)
1791 if (is_loopback (ch))
1793 /* It is a loopback channel after all... */
1797 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1800 /* Initialize FWD/BCK data */
1801 c = fwd ? ch->dest : ch->root;
1802 rel = fwd ? ch->dest_rel : ch->root_rel;
1810 GNUNET_STATISTICS_update (stats, "# data received", 1, GNUNET_NO);
1812 mid = ntohl (msg->mid);
1813 LOG (GNUNET_ERROR_TYPE_DEBUG, "!! got mid %u\n", mid);
1815 if (GNUNET_NO == ch->reliable ||
1816 ( !GM_is_pid_bigger (rel->mid_recv, mid) &&
1817 GM_is_pid_bigger (rel->mid_recv + 64, mid) ) )
1819 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RECV %u\n", mid);
1820 if (GNUNET_YES == ch->reliable)
1822 /* Is this the exact next expected messasge? */
1823 if (mid == rel->mid_recv)
1825 LOG (GNUNET_ERROR_TYPE_DEBUG, "as expected\n");
1827 send_client_data (ch, msg, fwd);
1831 LOG (GNUNET_ERROR_TYPE_DEBUG, "save for later\n");
1832 add_buffered_data (msg, rel);
1837 /* Tunnel is unreliable: send to clients directly */
1838 /* FIXME: accept Out Of Order traffic */
1839 rel->mid_recv = mid + 1;
1840 send_client_data (ch, msg, fwd);
1845 GNUNET_break_op (GM_is_pid_bigger (rel->mid_recv, mid));
1846 LOG (GNUNET_ERROR_TYPE_DEBUG,
1847 " !!! MID %u not expected (%u - %u), dropping!\n",
1848 mid, rel->mid_recv, rel->mid_recv + 63);
1851 GMCH_send_data_ack (ch, fwd);
1856 * Handler for mesh network traffic end-to-end ACKs.
1858 * @param ch Channel on which we got this message.
1859 * @param msg Data message.
1860 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1861 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1862 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1863 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1866 GMCH_handle_data_ack (struct MeshChannel *ch,
1867 const struct GNUNET_MESH_DataACK *msg,
1870 struct MeshChannelReliability *rel;
1871 struct MeshReliableMessage *copy;
1872 struct MeshReliableMessage *next;
1876 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1877 if (GNUNET_SYSERR == fwd)
1879 if (is_loopback (ch))
1881 /* It is a loopback channel after all... */
1885 /* Inverted: if message came 'FWD' is a 'BCK ACK'. */
1886 fwd = (NULL != ch->dest) ? GNUNET_NO : GNUNET_YES;
1889 ack = ntohl (msg->mid);
1890 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! %s ACK %u\n",
1891 (GNUNET_YES == fwd) ? "FWD" : "BCK", ack);
1893 if (GNUNET_YES == fwd)
1903 GNUNET_break_op (0);
1907 /* Free ACK'd copies: no need to retransmit those anymore */
1908 for (work = GNUNET_NO, copy = rel->head_sent; copy != NULL; copy = next)
1910 if (GM_is_pid_bigger (copy->mid, ack))
1912 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! head %u, out!\n", copy->mid);
1913 channel_rel_free_sent (rel, msg);
1917 LOG (GNUNET_ERROR_TYPE_DEBUG, " !! id %u\n", copy->mid);
1919 rel_message_free (copy, GNUNET_YES);
1922 /* ACK client if needed */
1923 GMCH_allow_client (ch, fwd);
1925 /* If some message was free'd, update the retransmission delay */
1926 if (GNUNET_YES == work)
1928 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
1930 GNUNET_SCHEDULER_cancel (rel->retry_task);
1931 if (NULL != rel->head_sent && NULL == rel->head_sent->q)
1933 struct GNUNET_TIME_Absolute new_target;
1934 struct GNUNET_TIME_Relative delay;
1936 delay = GNUNET_TIME_relative_multiply (rel->retry_timer,
1937 MESH_RETRANSMIT_MARGIN);
1938 new_target = GNUNET_TIME_absolute_add (rel->head_sent->timestamp,
1940 delay = GNUNET_TIME_absolute_get_remaining (new_target);
1942 GNUNET_SCHEDULER_add_delayed (delay,
1943 &channel_retransmit_message,
1946 else /* either no more traffic to ack or traffic has just been queued */
1948 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
1951 else /* work was done but no task was pending? shouldn't happen! */
1960 * Handler for channel create messages.
1962 * Does not have fwd parameter because it's always 'FWD': channel is incoming.
1964 * @param t Tunnel this channel will be in.
1965 * @param msg Channel crate message.
1967 struct MeshChannel *
1968 GMCH_handle_create (struct MeshTunnel3 *t,
1969 const struct GNUNET_MESH_ChannelCreate *msg)
1971 MESH_ChannelNumber chid;
1972 struct MeshChannel *ch;
1973 struct MeshClient *c;
1975 chid = ntohl (msg->chid);
1977 ch = GMT_get_channel (t, chid);
1980 /* Create channel */
1981 ch = channel_new (t, NULL, 0);
1984 channel_set_options (ch, ntohl (msg->opt));
1986 /* Find a destination client */
1987 ch->port = ntohl (msg->port);
1988 LOG (GNUNET_ERROR_TYPE_DEBUG, " port %u\n", ch->port);
1989 c = GML_client_get_by_port (ch->port);
1992 LOG (GNUNET_ERROR_TYPE_DEBUG, " no client has port registered\n");
1993 if (is_loopback (ch))
1995 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback: destroy on handler\n");
2000 LOG (GNUNET_ERROR_TYPE_DEBUG, " not loopback: destroy now\n");
2008 LOG (GNUNET_ERROR_TYPE_DEBUG, " client %p has port registered\n", c);
2011 add_destination (ch, c);
2012 if (GNUNET_YES == ch->reliable)
2013 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Reliable\n");
2015 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Not Reliable\n");
2017 send_client_create (ch);
2018 send_ack (ch, GNUNET_YES);
2025 * Handler for channel NACK messages.
2027 * NACK messages always go dest -> root, no need for 'fwd' or 'msg' parameter.
2029 * @param ch Channel.
2032 GMCH_handle_nack (struct MeshChannel *ch)
2034 send_client_nack (ch);
2040 * Handler for channel ack messages.
2042 * @param ch Channel.
2043 * @param msg Message.
2044 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2045 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2046 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2047 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2050 GMCH_handle_ack (struct MeshChannel *ch,
2051 const struct GNUNET_MESH_ChannelManage *msg,
2054 /* If this is a remote (non-loopback) channel, find 'fwd'. */
2055 if (GNUNET_SYSERR == fwd)
2057 if (is_loopback (ch))
2059 /* It is a loopback channel after all... */
2063 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
2066 channel_confirm (ch, !fwd);
2071 * Handler for channel destroy messages.
2073 * @param ch Channel to be destroyed of.
2074 * @param msg Message.
2075 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
2076 * #GNUNET_YES if message is FWD on the respective channel (loopback)
2077 * #GNUNET_NO if message is BCK on the respective channel (loopback)
2078 * #GNUNET_SYSERR if message on a one-ended channel (remote)
2081 GMCH_handle_destroy (struct MeshChannel *ch,
2082 const struct GNUNET_MESH_ChannelManage *msg,
2085 struct MeshTunnel3 *t;
2087 /* If this is a remote (non-loopback) channel, find 'fwd'. */
2088 if (GNUNET_SYSERR == fwd)
2090 if (is_loopback (ch))
2092 /* It is a loopback channel after all... */
2096 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
2100 if ( (fwd && NULL == ch->dest) || (!fwd && NULL == ch->root) )
2102 /* Not for us (don't destroy twice a half-open loopback channel) */
2107 send_destroy (ch, GNUNET_YES);
2109 GMT_destroy_if_empty (t);
2114 * Sends an already built message on a channel.
2116 * If the channel is on a loopback tunnel, notifies the appropriate destination
2119 * On a normal channel passes the message to the tunnel for encryption and
2120 * sending on a connection.
2122 * This function DOES NOT save the message for retransmission.
2124 * @param message Message to send. Function makes a copy of it.
2125 * @param ch Channel on which this message is transmitted.
2126 * @param fwd Is this a fwd message?
2127 * @param existing_copy This is a retransmission, don't save a copy.
2130 GMCH_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
2131 struct MeshChannel *ch, int fwd,
2132 void *existing_copy)
2134 struct MeshChannelQueue *q;
2137 type = ntohs (message->type);
2138 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMCH Send %s %s on channel %s\n",
2139 GM_f2s (fwd), GM_m2s (type),
2142 if (GMT_is_loopback (ch->t))
2144 handle_loopback (ch, message, fwd);
2150 case GNUNET_MESSAGE_TYPE_MESH_DATA:
2152 if (GNUNET_YES == ch->reliable)
2154 q = GNUNET_new (struct MeshChannelQueue);
2156 if (NULL == existing_copy)
2157 q->copy = channel_save_copy (ch, message, fwd);
2160 q->copy = (struct MeshReliableMessage *) existing_copy;
2161 if (NULL != q->copy->q)
2163 /* Last retransmission was queued but not yet sent!
2164 * This retransmission was scheduled by a ch_message_sent which
2165 * followed a very fast RTT, so the tiny delay made the
2166 * retransmission function to execute before the previous
2167 * retransmitted message even had a chance to leave the peer.
2168 * Cancel this message and wait until the pending
2169 * retransmission leaves the peer and ch_message_sent starts
2170 * the timer for the next one.
2173 LOG (GNUNET_ERROR_TYPE_DEBUG,
2174 " exisitng copy not yet transmitted!\n");
2177 LOG (GNUNET_ERROR_TYPE_DEBUG,
2178 " using existing copy: %p {r:%p q:%p t:%u}\n",
2180 q->copy->rel, q->copy->q, q->copy->type);
2182 LOG (GNUNET_ERROR_TYPE_DEBUG, " new q: %p\n", q);
2184 q->q = GMT_send_prebuilt_message (message, ch->t, ch,
2185 NULL != existing_copy,
2186 &ch_message_sent, q);
2187 /* q itself is stored in copy */
2191 fire_and_forget (message, ch, GNUNET_NO);
2196 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
2197 if (GNUNET_YES == fwd)
2199 /* BCK ACK (going FWD) is just a response for a SYNACK, don't keep*/
2200 fire_and_forget (message, ch, GNUNET_YES);
2204 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
2205 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
2206 q = GNUNET_new (struct MeshChannelQueue);
2208 q->rel = fwd ? ch->root_rel : ch->dest_rel;
2209 if (NULL != q->rel->uniq)
2211 if (NULL != q->rel->uniq->q)
2213 GMT_cancel (q->rel->uniq->q);
2214 /* ch_message_sent is called, freeing and NULLing uniq */
2218 GNUNET_free (q->rel->uniq);
2221 q->q = GMT_send_prebuilt_message (message, ch->t, ch, GNUNET_YES,
2222 &ch_message_sent, q);
2227 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
2228 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK:
2229 fire_and_forget (message, ch, GNUNET_YES);
2235 LOG (GNUNET_ERROR_TYPE_DEBUG, "type %s unknown!\n", GM_m2s (type));
2236 fire_and_forget (message, ch, GNUNET_YES);
2242 * Get the static string for identification of the channel.
2244 * @param ch Channel.
2246 * @return Static string with the channel IDs.
2249 GMCH_2s (const struct MeshChannel *ch)
2251 static char buf[64];
2254 return "(NULL Channel)";
2256 sprintf (buf, "%s:%u gid:%X (%X / %X)",
2257 GMT_2s (ch->t), ch->port, ch->gid, ch->lid_root, ch->lid_dest);