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.
65 * Info needed to retry a message in case it gets lost.
67 struct MeshReliableMessage
70 * Double linked list, FIFO style
72 struct MeshReliableMessage *next;
73 struct MeshReliableMessage *prev;
76 * Type of message (payload, channel management).
81 * Tunnel Reliability queue this message is in.
83 struct MeshChannelReliability *rel;
86 * ID of the message (ACK needed to free)
93 struct MeshTunnel3Queue *q;
96 * When was this message issued (to calculate ACK delay)
98 struct GNUNET_TIME_Absolute timestamp;
100 /* struct GNUNET_MESH_Data with payload */
105 * Info about the traffic state for a client in a channel.
107 struct MeshChannelReliability
110 * Channel this is about.
112 struct MeshChannel *ch;
115 * DLL of messages sent and not yet ACK'd.
117 struct MeshReliableMessage *head_sent;
118 struct MeshReliableMessage *tail_sent;
121 * DLL of messages received out of order.
123 struct MeshReliableMessage *head_recv;
124 struct MeshReliableMessage *tail_recv;
132 * Next MID to use for outgoing traffic.
137 * Next MID expected for incoming traffic.
142 * Can we send data to the client?
147 * Can the client send data to us?
152 * Task to resend/poll in case no ACK is received.
154 GNUNET_SCHEDULER_TaskIdentifier retry_task;
157 * Counter for exponential backoff.
159 struct GNUNET_TIME_Relative retry_timer;
162 * How long does it usually take to get an ACK.
164 struct GNUNET_TIME_Relative expected_delay;
169 * Struct containing all information regarding a channel to a remote client.
174 * Tunnel this channel is in.
176 struct MeshTunnel3 *t;
179 * Destination port of the channel.
184 * Global channel number ( < GNUNET_MESH_LOCAL_CHANNEL_ID_CLI)
186 MESH_ChannelNumber gid;
189 * Local tunnel number for root (owner) client.
190 * ( >= GNUNET_MESH_LOCAL_CHANNEL_ID_CLI or 0 )
192 MESH_ChannelNumber lid_root;
195 * Local tunnel number for local destination clients (incoming number)
196 * ( >= GNUNET_MESH_LOCAL_CHANNEL_ID_SERV or 0).
198 MESH_ChannelNumber lid_dest;
203 enum MeshChannelState state;
206 * Is the tunnel bufferless (minimum latency)?
211 * Is the tunnel reliable?
216 * Last time the channel was used
218 struct GNUNET_TIME_Absolute timestamp;
221 * Client owner of the tunnel, if any
223 struct MeshClient *root;
226 * Client destination of the tunnel, if any.
228 struct MeshClient *dest;
231 * Flag to signal the destruction of the channel.
232 * If this is set GNUNET_YES the channel will be destroyed
233 * when the queue is empty.
238 * Total messages pending for this channel, payload or not.
240 unsigned int pending_messages;
244 * Only present (non-NULL) at the owner of a tunnel.
246 struct MeshChannelReliability *root_rel;
250 * Only present (non-NULL) at the destination of a tunnel.
252 struct MeshChannelReliability *dest_rel;
257 /******************************************************************************/
258 /******************************* GLOBALS ***********************************/
259 /******************************************************************************/
262 * Global handle to the statistics service.
264 extern struct GNUNET_STATISTICS_Handle *stats;
267 * Local peer own ID (memory efficient handle).
269 extern GNUNET_PEER_Id myid;
272 /******************************************************************************/
273 /******************************** STATIC ***********************************/
274 /******************************************************************************/
277 * Destroy a reliable message after it has been acknowledged, either by
278 * direct mid ACK or bitfield. Updates the appropriate data structures and
279 * timers and frees all memory.
281 * @param copy Message that is no longer needed: remote peer got it.
282 * @param update_time Is the timing information relevant?
283 * If this message is ACK in a batch the timing information
284 * is skewed by the retransmission, count only for the
285 * retransmitted message.
288 rel_message_free (struct MeshReliableMessage *copy, int update_time);
291 * We have received a message out of order, or the client is not ready.
292 * Buffer it until we receive an ACK from the client or the missing
293 * message from the channel.
295 * @param msg Message to buffer (MUST be of type MESH_DATA).
296 * @param rel Reliability data to the corresponding direction.
299 add_buffered_data (const struct GNUNET_MESH_Data *msg,
300 struct MeshChannelReliability *rel)
302 struct MeshReliableMessage *copy;
303 struct MeshReliableMessage *prev;
307 size = ntohs (msg->header.size);
308 mid = ntohl (msg->mid);
310 LOG (GNUNET_ERROR_TYPE_DEBUG, "add_buffered_data %u\n", mid);
312 copy = GNUNET_malloc (sizeof (*copy) + size);
315 copy->type = GNUNET_MESSAGE_TYPE_MESH_DATA;
316 memcpy (©[1], msg, size);
320 // FIXME do something better than O(n), although n < 64...
321 // FIXME start from the end (most messages are the latest ones)
322 for (prev = rel->head_recv; NULL != prev; prev = prev->next)
324 LOG (GNUNET_ERROR_TYPE_DEBUG, " prev %u\n", prev->mid);
325 if (GMC_is_pid_bigger (prev->mid, mid))
327 LOG (GNUNET_ERROR_TYPE_DEBUG, " bingo!\n");
328 GNUNET_CONTAINER_DLL_insert_before (rel->head_recv, rel->tail_recv,
333 LOG (GNUNET_ERROR_TYPE_DEBUG, " insert at tail!\n");
334 GNUNET_CONTAINER_DLL_insert_tail (rel->head_recv, rel->tail_recv, copy);
335 LOG (GNUNET_ERROR_TYPE_DEBUG, "add_buffered_data END\n");
339 * Add a destination client to a channel, initializing all data structures
340 * in the channel and the client.
342 * @param ch Channel to which add the destination.
343 * @param c Client which to add to the channel.
346 add_destination (struct MeshChannel *ch, struct MeshClient *c)
348 if (NULL != ch->dest)
354 /* Assign local id as destination */
355 ch->lid_dest = GML_get_next_chid (c);
357 /* Store in client's hashmap */
358 GML_channel_add (c, ch->lid_dest, ch);
360 GNUNET_break (NULL == ch->dest_rel);
361 ch->dest_rel = GNUNET_new (struct MeshChannelReliability);
362 ch->dest_rel->ch = ch;
363 ch->dest_rel->expected_delay = MESH_RETRANSMIT_TIME;
370 * Send data to a client.
372 * If the client is ready, send directly, otherwise buffer while listening
376 * @param msg Message.
377 * @param fwd Is this a fwd (root->dest) message?
380 send_client_data (struct MeshChannel *ch,
381 const struct GNUNET_MESH_Data *msg,
386 if (ch->dest_rel->client_ready)
387 GML_send_data (ch->dest, msg, ch->lid_dest);
389 add_buffered_data (msg, ch->dest_rel);
393 if (ch->root_rel->client_ready)
394 GML_send_data (ch->root, msg, ch->lid_root);
396 add_buffered_data (msg, ch->root_rel);
402 * Send a buffered message to the client, for in order delivery or
403 * as result of client ACK.
405 * @param ch Channel on which to empty the message buffer.
406 * @param c Client to send to.
407 * @param fwd Is this to send FWD data?.
410 send_client_buffered_data (struct MeshChannel *ch,
411 struct MeshClient *c,
414 struct MeshReliableMessage *copy;
415 struct MeshChannelReliability *rel;
417 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_buffered_data\n");
418 rel = fwd ? ch->dest_rel : ch->root_rel;
419 if (GNUNET_NO == rel->client_ready)
421 LOG (GNUNET_ERROR_TYPE_DEBUG, "client not ready\n");
425 copy = rel->head_recv;
426 /* We never buffer channel management messages */
429 if (copy->mid == rel->mid_recv || GNUNET_NO == ch->reliable)
431 struct GNUNET_MESH_Data *msg = (struct GNUNET_MESH_Data *) ©[1];
433 LOG (GNUNET_ERROR_TYPE_DEBUG,
434 " have %u! now expecting %u\n",
435 copy->mid, rel->mid_recv + 1);
436 send_client_data (ch, msg, fwd);
439 GNUNET_CONTAINER_DLL_remove (rel->head_recv, rel->tail_recv, copy);
444 LOG (GNUNET_ERROR_TYPE_DEBUG,
445 " reliable && don't have %u, next is %u\n",
451 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_buffered_data END\n");
456 * Allow a client to send more data.
458 * In case the client was already allowed to send data, do nothing.
461 * @param fwd Is this a FWD ACK? (FWD ACKs are sent to root)
464 send_client_ack (struct MeshChannel *ch, int fwd)
466 struct MeshChannelReliability *rel = fwd ? ch->root_rel : ch->dest_rel;
468 LOG (GNUNET_ERROR_TYPE_DEBUG,
469 " sending %s ack to client on channel %s\n",
470 fwd ? "FWD" : "BCK", GMCH_2s (ch));
478 if (GNUNET_YES == rel->client_allowed)
480 LOG (GNUNET_ERROR_TYPE_DEBUG, " already allowed\n");
483 rel->client_allowed = GNUNET_YES;
485 GML_send_ack (fwd ? ch->root : ch->dest, fwd ? ch->lid_root : ch->lid_dest);
490 * Notify the root that the destination rejected the channel.
492 * @param ch Rejected channel.
495 send_client_nack (struct MeshChannel *ch)
497 if (NULL == ch->root)
502 GML_send_nack (ch->root, ch->lid_root);
507 * Destroy all reliable messages queued for a channel,
508 * during a channel destruction.
509 * Frees the reliability structure itself.
511 * @param rel Reliability data for a channel.
514 channel_rel_free_all (struct MeshChannelReliability *rel)
516 struct MeshReliableMessage *copy;
517 struct MeshReliableMessage *next;
522 for (copy = rel->head_recv; NULL != copy; copy = next)
525 GNUNET_CONTAINER_DLL_remove (rel->head_recv, rel->tail_recv, copy);
528 for (copy = rel->head_sent; NULL != copy; copy = next)
531 GNUNET_CONTAINER_DLL_remove (rel->head_sent, rel->tail_sent, copy);
534 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
535 GNUNET_SCHEDULER_cancel (rel->retry_task);
541 * Mark future messages as ACK'd.
543 * @param rel Reliability data.
544 * @param msg DataACK message with a bitfield of future ACK'd messages.
547 channel_rel_free_sent (struct MeshChannelReliability *rel,
548 const struct GNUNET_MESH_DataACK *msg)
550 struct MeshReliableMessage *copy;
551 struct MeshReliableMessage *next;
558 bitfield = msg->futures;
559 mid = ntohl (msg->mid);
560 LOG (GNUNET_ERROR_TYPE_DEBUG,
561 "!!! free_sent_reliable %u %llX\n",
563 LOG (GNUNET_ERROR_TYPE_DEBUG,
564 " rel %p, head %p\n",
565 rel, rel->head_sent);
566 for (i = 0, copy = rel->head_sent;
567 i < 64 && NULL != copy && 0 != bitfield;
570 LOG (GNUNET_ERROR_TYPE_DEBUG,
571 " trying bit %u (mid %u)\n",
574 if (0 == (bitfield & mask))
577 LOG (GNUNET_ERROR_TYPE_DEBUG, " set!\n");
578 /* Bit was set, clear the bit from the bitfield */
581 /* The i-th bit was set. Do we have that copy? */
582 /* Skip copies with mid < target */
583 target = mid + i + 1;
584 LOG (GNUNET_ERROR_TYPE_DEBUG, " target %u\n", target);
585 while (NULL != copy && GMC_is_pid_bigger (target, copy->mid))
588 /* Did we run out of copies? (previously freed, it's ok) */
591 LOG (GNUNET_ERROR_TYPE_DEBUG, "run out of copies...\n");
595 /* Did we overshoot the target? (previously freed, it's ok) */
596 if (GMC_is_pid_bigger (copy->mid, target))
598 LOG (GNUNET_ERROR_TYPE_DEBUG, " next copy %u\n", copy->mid);
602 /* Now copy->mid == target, free it */
604 rel_message_free (copy, GNUNET_YES);
607 LOG (GNUNET_ERROR_TYPE_DEBUG, "free_sent_reliable END\n");
612 * We haven't received an ACK after a certain time: restransmit the message.
614 * @param cls Closure (MeshReliableMessage with the message to restransmit)
615 * @param tc TaskContext.
618 channel_retransmit_message (void *cls,
619 const struct GNUNET_SCHEDULER_TaskContext *tc)
621 struct MeshChannelReliability *rel = cls;
622 struct MeshReliableMessage *copy;
623 struct MeshChannel *ch;
624 struct GNUNET_MESH_Data *payload;
627 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
628 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
632 copy = rel->head_sent;
639 payload = (struct GNUNET_MESH_Data *) ©[1];
640 fwd = (rel == ch->root_rel);
642 /* Message not found in the queue that we are going to use. */
643 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RETRANSMIT %u\n", copy->mid);
645 GMCH_send_prebuilt_message (&payload->header, ch, fwd, GNUNET_YES);
646 GNUNET_STATISTICS_update (stats, "# data retransmitted", 1, GNUNET_NO);
648 copy->timestamp = GNUNET_TIME_absolute_get();
649 rel->retry_timer = GNUNET_TIME_STD_BACKOFF (rel->retry_timer);
650 rel->retry_task = GNUNET_SCHEDULER_add_delayed (rel->retry_timer,
651 &channel_retransmit_message,
657 * Destroy a reliable message after it has been acknowledged, either by
658 * direct mid ACK or bitfield. Updates the appropriate data structures and
659 * timers and frees all memory.
661 * @param copy Message that is no longer needed: remote peer got it.
662 * @param update_time Is the timing information relevant?
663 * If this message is ACK in a batch the timing information
664 * is skewed by the retransmission, count only for the
665 * retransmitted message.
668 rel_message_free (struct MeshReliableMessage *copy, int update_time)
670 struct MeshChannelReliability *rel;
671 struct GNUNET_TIME_Relative time;
674 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Freeing %u\n", copy->mid);
677 time = GNUNET_TIME_absolute_get_duration (copy->timestamp);
678 rel->expected_delay.rel_value_us *= 7;
679 rel->expected_delay.rel_value_us += time.rel_value_us;
680 rel->expected_delay.rel_value_us /= 8;
681 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! took %s\n",
682 GNUNET_STRINGS_relative_time_to_string (time, GNUNET_NO));
683 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! new expected delay %s\n",
684 GNUNET_STRINGS_relative_time_to_string (rel->expected_delay,
686 rel->retry_timer = rel->expected_delay;
690 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! batch free, ignoring timing\n");
692 GNUNET_CONTAINER_DLL_remove (rel->head_sent, rel->tail_sent, copy);
698 * Confirm we got a channel create.
700 * @param ch The channel to confirm.
701 * @param fwd Should we send a FWD ACK? (going dest->root)
704 channel_send_ack (struct MeshChannel *ch, int fwd)
706 struct GNUNET_MESH_ChannelManage msg;
708 msg.header.size = htons (sizeof (msg));
709 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK);
710 LOG (GNUNET_ERROR_TYPE_DEBUG,
711 " sending channel %s ack for channel %s\n",
712 fwd ? "FWD" : "BCK", GMCH_2s (ch));
714 msg.chid = htonl (ch->gid);
715 GMCH_send_prebuilt_message (&msg.header, ch, !fwd, GNUNET_NO);
720 * Notify that a channel create didn't succeed.
722 * @param ch The channel to reject.
725 channel_send_nack (struct MeshChannel *ch)
727 struct GNUNET_MESH_ChannelManage msg;
729 msg.header.size = htons (sizeof (msg));
730 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK);
731 LOG (GNUNET_ERROR_TYPE_DEBUG,
732 " sending channel NACK for channel %s\n",
735 msg.chid = htonl (ch->gid);
736 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_NO, GNUNET_NO);
741 * Channel was ACK'd by remote peer, mark as ready and cancel retransmission.
743 * @param ch Channel to mark as ready.
744 * @param fwd Was the ACK message a FWD ACK? (dest->root, SYNACK)
747 channel_confirm (struct MeshChannel *ch, int fwd)
749 struct MeshChannelReliability *rel;
750 struct MeshReliableMessage *copy;
751 struct MeshReliableMessage *next;
753 LOG (GNUNET_ERROR_TYPE_DEBUG,
754 " channel confirm %s %s:%X\n",
755 fwd ? "FWD" : "BCK", GMT_2s (ch->t), ch->gid);
756 ch->state = MESH_CHANNEL_READY;
758 rel = fwd ? ch->root_rel : ch->dest_rel;
759 rel->client_ready = GNUNET_YES;
760 for (copy = rel->head_sent; NULL != copy; copy = next)
762 struct GNUNET_MessageHeader *msg;
765 msg = (struct GNUNET_MessageHeader *) ©[1];
766 if (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE)
768 rel_message_free (copy, GNUNET_YES);
772 send_client_ack (ch, fwd);
774 /* In case of a FWD ACK (SYNACK) send a BCK ACK (ACK). */
776 channel_send_ack (ch, !fwd);
780 message_sent (void *cls,
781 struct MeshTunnel3 *t,
782 struct MeshTunnel3Queue *q,
783 uint16_t type, size_t size)
785 struct MeshReliableMessage *copy = cls;
786 struct MeshChannelReliability *rel = copy->rel;
788 copy->timestamp = GNUNET_TIME_absolute_get ();
789 if (GNUNET_SCHEDULER_NO_TASK == rel->retry_task)
792 GNUNET_TIME_relative_multiply (rel->expected_delay,
793 MESH_RETRANSMIT_MARGIN);
795 GNUNET_SCHEDULER_add_delayed (rel->retry_timer,
796 &channel_retransmit_message,
803 * Save a copy to retransmit in case it gets lost.
805 * Initializes all needed callbacks and timers.
807 * @param ch Channel this message goes on.
808 * @param msg Message to copy.
809 * @param fwd Is this fwd traffic?
811 static struct MeshReliableMessage *
812 channel_save_copy (struct MeshChannel *ch,
813 const struct GNUNET_MessageHeader *msg,
816 struct MeshChannelReliability *rel;
817 struct MeshReliableMessage *copy;
822 rel = fwd ? ch->root_rel : ch->dest_rel;
823 mid = rel->mid_send - 1;
824 type = ntohs (msg->type);
825 size = ntohs (msg->size);
827 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SAVE %u %s\n",
828 mid, GNUNET_MESH_DEBUG_M2S (type));
829 copy = GNUNET_malloc (sizeof (struct MeshReliableMessage) + size);
833 memcpy (©[1], msg, size);
834 GNUNET_CONTAINER_DLL_insert_tail (rel->head_sent, rel->tail_sent, copy);
841 * Destroy a channel and free all resources.
843 * @param ch Channel to destroy.
846 channel_destroy (struct MeshChannel *ch)
848 struct MeshClient *c;
853 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying channel %s:%u\n",
854 GMT_2s (ch->t), ch->gid);
860 GML_channel_remove (c, ch->lid_root, ch);
866 GML_channel_remove (c, ch->lid_dest, ch);
869 channel_rel_free_all (ch->root_rel);
870 channel_rel_free_all (ch->dest_rel);
872 GMT_remove_channel (ch->t, ch);
873 GNUNET_STATISTICS_update (stats, "# channels", -1, GNUNET_NO);
880 * Create a new channel.
882 * @param t Tunnel this channel is in.
883 * @param owner Client that owns the channel, NULL for foreign channels.
884 * @param lid_root Local ID for root client.
886 * @return A new initialized channel. NULL on error.
888 static struct MeshChannel *
889 channel_new (struct MeshTunnel3 *t,
890 struct MeshClient *owner,
891 MESH_ChannelNumber lid_root)
893 struct MeshChannel *ch;
895 ch = GNUNET_new (struct MeshChannel);
897 ch->lid_root = lid_root;
900 GNUNET_STATISTICS_update (stats, "# channels", 1, GNUNET_NO);
904 ch->gid = GMT_get_next_chid (t);
905 GML_channel_add (owner, lid_root, ch);
907 GMT_add_channel (t, ch);
914 * Set options in a channel, extracted from a bit flag field
916 * @param ch Channel to set options to.
917 * @param options Bit array in host byte order.
920 channel_set_options (struct MeshChannel *ch, uint32_t options)
922 ch->nobuffer = (options & GNUNET_MESH_OPTION_NOBUFFER) != 0 ?
923 GNUNET_YES : GNUNET_NO;
924 ch->reliable = (options & GNUNET_MESH_OPTION_RELIABLE) != 0 ?
925 GNUNET_YES : GNUNET_NO;
929 is_loopback (const struct MeshChannel *ch)
932 return GMT_is_loopback (ch->t);
934 return (NULL != ch->root && NULL != ch->dest);
939 * Handle a loopback message: call the appropriate handler for the message type.
941 * @param ch Channel this message is on.
942 * @param msgh Message header.
943 * @param fwd Is this FWD traffic?
946 handle_loopback (struct MeshChannel *ch,
947 const struct GNUNET_MessageHeader *msgh,
952 type = ntohs (msgh->type);
953 LOG (GNUNET_ERROR_TYPE_DEBUG,
954 "Loopback %s %s message!\n",
955 fwd ? "FWD" : "BCK", GNUNET_MESH_DEBUG_M2S (type));
959 case GNUNET_MESSAGE_TYPE_MESH_DATA:
960 /* Don't send hop ACK, wait for client to ACK */
961 GMCH_handle_data (ch, (struct GNUNET_MESH_Data *) msgh, fwd);
964 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
965 GMCH_handle_data_ack (ch, (struct GNUNET_MESH_DataACK *) msgh, fwd);
968 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
969 GMCH_handle_create (ch->t,
970 (struct GNUNET_MESH_ChannelCreate *) msgh);
973 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
975 (struct GNUNET_MESH_ChannelManage *) msgh,
979 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK:
980 GMCH_handle_nack (ch);
983 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
984 GMCH_handle_destroy (ch,
985 (struct GNUNET_MESH_ChannelManage *) msgh,
991 LOG (GNUNET_ERROR_TYPE_DEBUG,
992 "end-to-end message not known (%u)\n",
999 /******************************************************************************/
1000 /******************************** API ***********************************/
1001 /******************************************************************************/
1007 * @param ch Channel.
1012 GMCH_get_id (const struct MeshChannel *ch)
1019 * Get the channel tunnel.
1021 * @param ch Channel to get the tunnel from.
1023 * @return tunnel of the channel.
1025 struct MeshTunnel3 *
1026 GMCH_get_tunnel (const struct MeshChannel *ch)
1033 * Get free buffer space towards the client on a specific channel.
1035 * @param ch Channel.
1036 * @param fwd Is query about FWD traffic?
1038 * @return Free buffer space [0 - 64]
1041 GMCH_get_buffer (struct MeshChannel *ch, int fwd)
1043 struct MeshChannelReliability *rel;
1045 rel = fwd ? ch->dest_rel : ch->root_rel;
1047 /* If rel is NULL it means that the end is not yet created,
1048 * most probably is a loopback channel at the point of sending
1049 * the ChannelCreate to itself.
1054 return (64 - rel->n_recv);
1059 * Get flow control status of end point: is client allow to send?
1061 * @param ch Channel.
1062 * @param fwd Is query about FWD traffic? (Request root status).
1064 * @return #GNUNET_YES if client is allowed to send us data.
1067 GMCH_get_allowed (struct MeshChannel *ch, int fwd)
1069 struct MeshChannelReliability *rel;
1071 rel = fwd ? ch->root_rel : ch->dest_rel;
1073 return rel->client_allowed;
1078 * Is the root client for this channel on this peer?
1080 * @param ch Channel.
1081 * @param fwd Is this for fwd traffic?
1083 * @return #GNUNET_YES in case it is.
1086 GMCH_is_origin (struct MeshChannel *ch, int fwd)
1088 struct MeshClient *c;
1090 c = fwd ? ch->root : ch->dest;
1096 * Is the destination client for this channel on this peer?
1098 * @param ch Channel.
1099 * @param fwd Is this for fwd traffic?
1101 * @return #GNUNET_YES in case it is.
1104 GMCH_is_terminal (struct MeshChannel *ch, int fwd)
1106 struct MeshClient *c;
1108 c = fwd ? ch->dest : ch->root;
1114 * Notify the destination client that a new incoming channel was created.
1116 * @param ch Channel that was created.
1119 GMCH_send_create (struct MeshChannel *ch)
1123 if (NULL == ch->dest)
1127 opt |= GNUNET_YES == ch->reliable ? GNUNET_MESH_OPTION_RELIABLE : 0;
1128 opt |= GNUNET_YES == ch->nobuffer ? GNUNET_MESH_OPTION_NOBUFFER : 0;
1129 GML_send_channel_create (ch->dest, ch->lid_dest, ch->port, opt,
1130 GMT_get_destination (ch->t));
1135 * Notify a client that the channel is no longer valid.
1137 * @param ch Channel that is destroyed.
1140 GMCH_send_destroy (struct MeshChannel *ch)
1142 struct GNUNET_MESH_ChannelManage msg;
1144 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY);
1145 msg.header.size = htons (sizeof (msg));
1146 msg.chid = htonl (ch->gid);
1148 /* If root is not NULL, notify.
1149 * If it's NULL, check lid_root. When a local destroy comes in, root
1150 * is set to NULL but lid_root is left untouched. In this case, do nothing,
1151 * the client is the one who reuqested the channel to be destroyed.
1153 if (NULL != ch->root)
1154 GML_send_channel_destroy (ch->root, ch->lid_root);
1155 else if (0 == ch->lid_root)
1156 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_NO, GNUNET_NO);
1158 if (NULL != ch->dest)
1159 GML_send_channel_destroy (ch->dest, ch->lid_dest);
1160 else if (0 == ch->lid_dest)
1161 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_YES, GNUNET_NO);
1166 * Send an end-to-end ACK message for the most recent in-sequence payload.
1168 * If channel is not reliable, do nothing.
1170 * @param ch Channel this is about.
1171 * @param fwd Is for FWD traffic? (ACK dest->owner)
1174 GMCH_send_data_ack (struct MeshChannel *ch, int fwd)
1176 struct GNUNET_MESH_DataACK msg;
1177 struct MeshChannelReliability *rel;
1178 struct MeshReliableMessage *copy;
1183 if (GNUNET_NO == ch->reliable)
1187 rel = fwd ? ch->dest_rel : ch->root_rel;
1188 ack = rel->mid_recv - 1;
1189 LOG (GNUNET_ERROR_TYPE_DEBUG,
1190 " !! Send DATA_ACK for %u\n",
1193 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_DATA_ACK);
1194 msg.header.size = htons (sizeof (msg));
1195 msg.chid = htonl (ch->gid);
1197 for (copy = rel->head_recv; NULL != copy; copy = copy->next)
1199 if (copy->type != GNUNET_MESSAGE_TYPE_MESH_DATA)
1201 LOG (GNUNET_ERROR_TYPE_DEBUG,
1202 "!! Type %s, expected DATA\n",
1203 GNUNET_MESH_DEBUG_M2S (copy->type));
1206 if (copy->mid == ack + 1)
1211 delta = copy->mid - (ack + 1);
1214 mask = 0x1LL << delta;
1215 msg.futures |= mask;
1216 LOG (GNUNET_ERROR_TYPE_DEBUG,
1217 " !! setting bit for %u (delta %u) (%llX) -> %llX\n",
1218 copy->mid, delta, mask, msg.futures);
1220 msg.mid = htonl (ack);
1221 LOG (GNUNET_ERROR_TYPE_DEBUG,
1222 "!!! ACK for %u, futures %llX\n",
1225 GMCH_send_prebuilt_message (&msg.header, ch, !fwd, GNUNET_NO);
1226 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_data_ack END\n");
1231 * Allow a client to send us more data, in case it was choked.
1233 * @param ch Channel.
1234 * @param fwd Is this about FWD traffic? (Root client).
1237 GMCH_allow_client (struct MeshChannel *ch, int fwd)
1239 struct MeshChannelReliability *rel;
1240 unsigned int buffer;
1242 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMCH allow\n");
1244 if (MESH_CHANNEL_READY != ch->state)
1246 LOG (GNUNET_ERROR_TYPE_DEBUG, " channel not ready yet!\n");
1250 if (GNUNET_YES == ch->reliable)
1252 rel = fwd ? ch->root_rel : ch->dest_rel;
1258 if (NULL != rel->head_sent && 64 <= rel->mid_send - rel->head_sent->mid)
1260 LOG (GNUNET_ERROR_TYPE_DEBUG, " too big MID gap! Wait for ACK.\n");
1265 if (is_loopback (ch))
1266 buffer = GMCH_get_buffer (ch, fwd);
1268 buffer = GMT_get_connections_buffer (ch->t);
1272 LOG (GNUNET_ERROR_TYPE_DEBUG, " no buffer space.\n");
1276 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space %u, allowing\n", buffer);
1277 send_client_ack (ch, fwd);
1284 * @param ch Channel.
1287 GMCH_debug (struct MeshChannel *ch)
1291 LOG (GNUNET_ERROR_TYPE_DEBUG, "*** DEBUG NULL CHANNEL ***\n");
1294 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %s:%X (%p)\n",
1295 GMT_2s (ch->t), ch->gid, ch);
1296 LOG (GNUNET_ERROR_TYPE_DEBUG, " root %p/%p\n",
1297 ch->root, ch->root_rel);
1298 if (NULL != ch->root)
1300 LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->root));
1301 LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n",
1302 ch->root_rel->client_ready ? "YES" : "NO");
1303 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_root);
1305 LOG (GNUNET_ERROR_TYPE_DEBUG, " dest %p/%p\n",
1306 ch->dest, ch->dest_rel);
1307 if (NULL != ch->dest)
1309 LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->dest));
1310 LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n",
1311 ch->dest_rel->client_ready ? "YES" : "NO");
1312 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_dest);
1318 * Handle an ACK given by a client.
1320 * Mark client as ready and send him any buffered data we could have for him.
1322 * @param ch Channel.
1323 * @param fwd Is this a "FWD ACK"? (FWD ACKs are sent by dest and go BCK)
1326 GMCH_handle_local_ack (struct MeshChannel *ch, int fwd)
1328 struct MeshChannelReliability *rel;
1329 struct MeshClient *c;
1331 rel = fwd ? ch->dest_rel : ch->root_rel;
1332 c = fwd ? ch->dest : ch->root;
1334 rel->client_ready = GNUNET_YES;
1335 send_client_buffered_data (ch, c, fwd);
1336 if (is_loopback (ch))
1338 unsigned int buffer;
1340 buffer = GMCH_get_buffer (ch, fwd);
1342 GMCH_allow_client (ch, fwd);
1346 GMT_send_connection_acks (ch->t);
1351 * Handle data given by a client.
1353 * Check whether the client is allowed to send in this tunnel, save if channel
1354 * is reliable and send an ACK to the client if there is still buffer space
1357 * @param ch Channel.
1358 * @param c Client which sent the data.
1359 * @param message Message.
1360 * @param fwd Is this a FWD data?
1362 * @return GNUNET_OK if everything goes well, GNUNET_SYSERR in case of en error.
1365 GMCH_handle_local_data (struct MeshChannel *ch,
1366 struct MeshClient *c,
1367 struct GNUNET_MessageHeader *message,
1370 struct MeshChannelReliability *rel;
1371 struct GNUNET_MESH_Data *payload;
1372 size_t size = ntohs (message->size);
1373 uint16_t p2p_size = sizeof(struct GNUNET_MESH_Data) + size;
1374 unsigned char cbuf[p2p_size];
1376 /* Is the client in the channel? */
1383 GNUNET_break_op (0);
1384 return GNUNET_SYSERR;
1387 rel = fwd ? ch->root_rel : ch->dest_rel;
1389 if (GNUNET_NO == rel->client_allowed)
1391 GNUNET_break_op (0);
1392 return GNUNET_SYSERR;
1395 rel->client_allowed = GNUNET_NO;
1397 /* Ok, everything is correct, send the message. */
1398 payload = (struct GNUNET_MESH_Data *) cbuf;
1399 payload->mid = htonl (rel->mid_send);
1401 memcpy (&payload[1], message, size);
1402 payload->header.size = htons (p2p_size);
1403 payload->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_DATA);
1404 payload->chid = htonl (ch->gid);
1405 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channel...\n");
1406 GMCH_send_prebuilt_message (&payload->header, ch, fwd, GNUNET_NO);
1408 if (is_loopback (ch))
1410 if (GMCH_get_buffer (ch, fwd) > 0)
1411 send_client_ack (ch, fwd);
1416 if (GMT_get_connections_buffer (ch->t) > 0)
1418 send_client_ack (ch, fwd);
1426 * Handle a channel destroy requested by a client.
1428 * Destroy the channel and the tunnel in case this was the last channel.
1430 * @param ch Channel.
1431 * @param c Client that requested the destruction (to avoid notifying him).
1434 GMCH_handle_local_destroy (struct MeshChannel *ch,
1435 struct MeshClient *c)
1437 struct MeshTunnel3 *t;
1439 /* Cleanup after the tunnel */
1442 LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is destination.\n", GML_2s (c));
1443 GML_client_delete_channel (c, ch, ch->lid_dest);
1448 LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is owner.\n", GML_2s (c));
1449 GML_client_delete_channel (c, ch, ch->lid_root);
1454 GMCH_send_destroy (ch);
1455 channel_destroy (ch);
1456 GMT_destroy_if_empty (t);
1461 * Handle a channel create requested by a client.
1463 * Create the channel and the tunnel in case this was the first0 channel.
1465 * @param c Client that requested the creation (will be the root).
1466 * @param msg Create Channel message.
1468 * @return GNUNET_OK if everything went fine, GNUNET_SYSERR otherwise.
1471 GMCH_handle_local_create (struct MeshClient *c,
1472 struct GNUNET_MESH_ChannelMessage *msg)
1474 struct MeshChannel *ch;
1475 struct MeshTunnel3 *t;
1476 struct MeshPeer *peer;
1477 MESH_ChannelNumber chid;
1479 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s:%u\n",
1480 GNUNET_i2s (&msg->peer), ntohl (msg->port));
1481 chid = ntohl (msg->channel_id);
1483 /* Sanity check for duplicate channel IDs */
1484 if (NULL != GML_channel_get (c, chid))
1487 return GNUNET_SYSERR;
1490 peer = GMP_get (&msg->peer);
1491 GMP_add_tunnel (peer);
1492 t = GMP_get_tunnel (peer);
1494 if (GMP_get_short_id (peer) == myid)
1496 GMT_change_state (t, MESH_TUNNEL3_READY);
1503 /* Create channel */
1504 ch = channel_new (t, c, chid);
1508 return GNUNET_SYSERR;
1510 ch->port = ntohl (msg->port);
1511 channel_set_options (ch, ntohl (msg->opt));
1513 /* In unreliable channels, we'll use the DLL to buffer BCK data */
1514 ch->root_rel = GNUNET_new (struct MeshChannelReliability);
1515 ch->root_rel->ch = ch;
1516 ch->root_rel->expected_delay = MESH_RETRANSMIT_TIME;
1518 LOG (GNUNET_ERROR_TYPE_DEBUG, "CREATED CHANNEL %s\n", GMCH_2s (ch));
1520 /* Send create channel */
1522 struct GNUNET_MESH_ChannelCreate msgcc;
1524 msgcc.header.size = htons (sizeof (msgcc));
1525 msgcc.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE);
1526 msgcc.chid = htonl (ch->gid);
1527 msgcc.port = msg->port;
1528 msgcc.opt = msg->opt;
1530 GMT_send_prebuilt_message (&msgcc.header, t, ch, GNUNET_YES, NULL, NULL);
1537 * Handler for mesh network payload traffic.
1539 * @param ch Channel for the message.
1540 * @param msg Unencryted data message.
1541 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1542 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1543 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1544 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1547 GMCH_handle_data (struct MeshChannel *ch,
1548 const struct GNUNET_MESH_Data *msg,
1551 struct MeshChannelReliability *rel;
1552 struct MeshClient *c;
1555 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1556 if (GNUNET_SYSERR == fwd)
1558 if (is_loopback (ch))
1560 /* It is a loopback channel after all... */
1564 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1567 /* Initialize FWD/BCK data */
1568 c = fwd ? ch->dest : ch->root;
1569 rel = fwd ? ch->dest_rel : ch->root_rel;
1577 GNUNET_STATISTICS_update (stats, "# data received", 1, GNUNET_NO);
1579 mid = ntohl (msg->mid);
1580 LOG (GNUNET_ERROR_TYPE_DEBUG, "!! got mid %u\n", mid);
1582 if (GNUNET_NO == ch->reliable ||
1583 ( !GMC_is_pid_bigger (rel->mid_recv, mid) &&
1584 GMC_is_pid_bigger (rel->mid_recv + 64, mid) ) )
1586 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RECV %u\n", mid);
1587 if (GNUNET_YES == ch->reliable)
1589 /* Is this the exact next expected messasge? */
1590 if (mid == rel->mid_recv)
1592 LOG (GNUNET_ERROR_TYPE_DEBUG, "as expected\n");
1594 send_client_data (ch, msg, fwd);
1598 LOG (GNUNET_ERROR_TYPE_DEBUG, "save for later\n");
1599 add_buffered_data (msg, rel);
1604 /* Tunnel is unreliable: send to clients directly */
1605 /* FIXME: accept Out Of Order traffic */
1606 rel->mid_recv = mid + 1;
1607 send_client_data (ch, msg, fwd);
1612 GNUNET_break_op (0);
1613 LOG (GNUNET_ERROR_TYPE_DEBUG,
1614 " MID %u not expected (%u - %u), dropping!\n",
1615 mid, rel->mid_recv, rel->mid_recv + 63);
1618 GMCH_send_data_ack (ch, fwd);
1623 * Handler for mesh network traffic end-to-end ACKs.
1625 * @param ch Channel on which we got this message.
1626 * @param msg Data message.
1627 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1628 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1629 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1630 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1633 GMCH_handle_data_ack (struct MeshChannel *ch,
1634 const struct GNUNET_MESH_DataACK *msg,
1637 struct MeshChannelReliability *rel;
1638 struct MeshReliableMessage *copy;
1639 struct MeshReliableMessage *next;
1643 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1644 if (GNUNET_SYSERR == fwd)
1646 if (is_loopback (ch))
1648 /* It is a loopback channel after all... */
1652 /* Inverted: if message came 'FWD' is a 'BCK ACK'. */
1653 fwd = (NULL != ch->dest) ? GNUNET_NO : GNUNET_YES;
1656 ack = ntohl (msg->mid);
1657 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! %s ACK %u\n",
1658 (GNUNET_YES == fwd) ? "FWD" : "BCK", ack);
1660 if (GNUNET_YES == fwd)
1670 GNUNET_break_op (0);
1674 /* Free ACK'd copies: no need to retransmit those anymore */
1675 for (work = GNUNET_NO, copy = rel->head_sent; copy != NULL; copy = next)
1677 if (GMC_is_pid_bigger (copy->mid, ack))
1679 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! head %u, out!\n", copy->mid);
1680 channel_rel_free_sent (rel, msg);
1684 LOG (GNUNET_ERROR_TYPE_DEBUG, " !! id %u\n", copy->mid);
1686 rel_message_free (copy, GNUNET_YES);
1689 /* ACK client if needed */
1690 GMCH_allow_client (ch, fwd);
1692 /* If some message was free'd, update the retransmission delay */
1693 if (GNUNET_YES == work)
1695 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
1697 GNUNET_SCHEDULER_cancel (rel->retry_task);
1698 if (NULL == rel->head_sent)
1700 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
1704 struct GNUNET_TIME_Absolute new_target;
1705 struct GNUNET_TIME_Relative delay;
1707 delay = GNUNET_TIME_relative_multiply (rel->retry_timer,
1708 MESH_RETRANSMIT_MARGIN);
1709 new_target = GNUNET_TIME_absolute_add (rel->head_sent->timestamp,
1711 delay = GNUNET_TIME_absolute_get_remaining (new_target);
1713 GNUNET_SCHEDULER_add_delayed (delay,
1714 &channel_retransmit_message,
1725 * Handler for channel create messages.
1727 * Does not have fwd parameter because it's always 'FWD': channel is incoming.
1729 * @param t Tunnel this channel will be in.
1730 * @param msg Channel crate message.
1732 struct MeshChannel *
1733 GMCH_handle_create (struct MeshTunnel3 *t,
1734 const struct GNUNET_MESH_ChannelCreate *msg)
1736 MESH_ChannelNumber chid;
1737 struct MeshChannel *ch;
1738 struct MeshClient *c;
1741 chid = ntohl (msg->chid);
1743 ch = GMT_get_channel (t, chid);
1746 /* Create channel */
1747 ch = channel_new (t, NULL, 0);
1750 channel_set_options (ch, ntohl (msg->opt));
1752 /* Find a destination client */
1753 port = ntohl (msg->port);
1754 LOG (GNUNET_ERROR_TYPE_DEBUG, " port %u\n", port);
1755 c = GML_client_get_by_port (port);
1758 /* TODO send reject */
1759 LOG (GNUNET_ERROR_TYPE_DEBUG, " no client has port registered\n");
1760 if (is_loopback (ch))
1762 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback: destroy on handler\n");
1763 channel_send_nack (ch);
1767 LOG (GNUNET_ERROR_TYPE_DEBUG, " not loopback: destroy now\n");
1768 channel_send_nack (ch);
1769 channel_destroy (ch);
1775 LOG (GNUNET_ERROR_TYPE_DEBUG, " client %p has port registered\n", c);
1778 add_destination (ch, c);
1779 if (GNUNET_YES == ch->reliable)
1780 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Reliable\n");
1782 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Not Reliable\n");
1784 GMCH_send_create (ch);
1785 channel_send_ack (ch, GNUNET_YES);
1792 * Handler for channel NACK messages.
1794 * NACK messages always go dest -> root, no need for 'fwd' or 'msg' parameter.
1796 * @param ch Channel.
1799 GMCH_handle_nack (struct MeshChannel *ch)
1801 send_client_nack (ch);
1802 channel_destroy (ch);
1807 * Handler for channel ack messages.
1809 * @param ch Channel.
1810 * @param msg Message.
1811 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1812 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1813 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1814 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1817 GMCH_handle_ack (struct MeshChannel *ch,
1818 const struct GNUNET_MESH_ChannelManage *msg,
1821 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1822 if (GNUNET_SYSERR == fwd)
1824 if (is_loopback (ch))
1826 /* It is a loopback channel after all... */
1830 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1833 channel_confirm (ch, !fwd);
1838 * Handler for channel destroy messages.
1840 * @param ch Channel to be destroyed of.
1841 * @param msg Message.
1842 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1843 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1844 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1845 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1848 GMCH_handle_destroy (struct MeshChannel *ch,
1849 const struct GNUNET_MESH_ChannelManage *msg,
1852 struct MeshTunnel3 *t;
1854 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1855 if (GNUNET_SYSERR == fwd)
1857 if (is_loopback (ch))
1859 /* It is a loopback channel after all... */
1863 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1867 if ( (fwd && NULL == ch->dest) || (!fwd && NULL == ch->root) )
1869 /* Not for us (don't destroy twice a half-open loopback channel) */
1874 GMCH_send_destroy (ch);
1875 channel_destroy (ch);
1876 GMT_destroy_if_empty (t);
1881 * Sends an already built message on a channel.
1883 * If the channel is on a loopback tunnel, notifies the appropriate destination
1886 * On a normal channel passes the message to the tunnel for encryption and
1887 * sending on a connection.
1889 * This function DOES NOT save the message for retransmission.
1891 * @param message Message to send. Function makes a copy of it.
1892 * @param ch Channel on which this message is transmitted.
1893 * @param fwd Is this a fwd message?
1894 * @param retransmission Is this a retransmission? (Don't save a copy)
1897 GMCH_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1898 struct MeshChannel *ch, int fwd,
1901 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMCH Send %s %s on channel %s\n",
1902 fwd ? "FWD" : "BCK", GNUNET_MESH_DEBUG_M2S (ntohs (message->type)),
1905 if (GMT_is_loopback (ch->t))
1907 handle_loopback (ch, message, fwd);
1911 if (GNUNET_YES == ch->reliable && GNUNET_NO == retransmission
1912 && ntohs (message->type) == GNUNET_MESSAGE_TYPE_MESH_DATA)
1914 struct MeshReliableMessage *copy;
1916 copy = channel_save_copy (ch, message, fwd);
1917 copy->q = GMT_send_prebuilt_message (message, ch->t, ch, fwd,
1918 &message_sent, copy);
1921 GMT_send_prebuilt_message (message, ch->t, ch, fwd, NULL, NULL);
1926 * Get the static string for identification of the channel.
1928 * @param ch Channel.
1930 * @return Static string with the channel IDs.
1933 GMCH_2s (const struct MeshChannel *ch)
1935 static char buf[64];
1938 return "(NULL Channel)";
1940 sprintf (buf, "%s:%X (%X / %X)",
1941 GMT_2s (ch->t), ch->gid, ch->lid_root, ch->lid_dest);