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_enc.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)
91 * When was this message issued (to calculate ACK delay)
93 struct GNUNET_TIME_Absolute timestamp;
95 /* struct GNUNET_MESH_Data with payload */
100 * Info about the traffic state for a client in a channel.
102 struct MeshChannelReliability
105 * Channel this is about.
107 struct MeshChannel *ch;
110 * DLL of messages sent and not yet ACK'd.
112 struct MeshReliableMessage *head_sent;
113 struct MeshReliableMessage *tail_sent;
116 * Messages pending to send.
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.
284 rel_message_free (struct MeshReliableMessage *copy);
287 * We have received a message out of order, or the client is not ready.
288 * Buffer it until we receive an ACK from the client or the missing
289 * message from the channel.
291 * @param msg Message to buffer (MUST be of type MESH_DATA).
292 * @param rel Reliability data to the corresponding direction.
295 add_buffered_data (const struct GNUNET_MESH_Data *msg,
296 struct MeshChannelReliability *rel)
298 struct MeshReliableMessage *copy;
299 struct MeshReliableMessage *prev;
303 size = ntohs (msg->header.size);
304 mid = ntohl (msg->mid);
306 LOG (GNUNET_ERROR_TYPE_DEBUG, "add_buffered_data %u\n", mid);
308 copy = GNUNET_malloc (sizeof (*copy) + size);
311 memcpy (©[1], msg, size);
315 // FIXME do something better than O(n), although n < 64...
316 // FIXME start from the end (most messages are the latest ones)
317 for (prev = rel->head_recv; NULL != prev; prev = prev->next)
319 LOG (GNUNET_ERROR_TYPE_DEBUG, " prev %u\n", prev->mid);
320 if (GMC_is_pid_bigger (prev->mid, mid))
322 LOG (GNUNET_ERROR_TYPE_DEBUG, " bingo!\n");
323 GNUNET_CONTAINER_DLL_insert_before (rel->head_recv, rel->tail_recv,
328 LOG (GNUNET_ERROR_TYPE_DEBUG, " insert at tail!\n");
329 GNUNET_CONTAINER_DLL_insert_tail (rel->head_recv, rel->tail_recv, copy);
330 LOG (GNUNET_ERROR_TYPE_DEBUG, "add_buffered_data END\n");
334 * Add a destination client to a channel, initializing all data structures
335 * in the channel and the client.
337 * @param ch Channel to which add the destination.
338 * @param c Client which to add to the channel.
341 add_destination (struct MeshChannel *ch, struct MeshClient *c)
343 if (NULL != ch->dest)
349 /* Assign local id as destination */
350 ch->lid_dest = GML_get_next_chid (c);
352 /* Store in client's hashmap */
353 GML_channel_add (c, ch->lid_dest, ch);
355 GNUNET_break (NULL == ch->dest_rel);
356 ch->dest_rel = GNUNET_new (struct MeshChannelReliability);
357 ch->dest_rel->ch = ch;
358 ch->dest_rel->expected_delay = MESH_RETRANSMIT_TIME;
365 * Send data to a client.
367 * If the client is ready, send directly, otherwise buffer while listening
371 * @param msg Message.
372 * @param fwd Is this a fwd (root->dest) message?
375 send_client_data (struct MeshChannel *ch,
376 const struct GNUNET_MESH_Data *msg,
381 if (ch->dest_rel->client_ready)
382 GML_send_data (ch->dest, msg, ch->lid_dest);
384 add_buffered_data (msg, ch->dest_rel);
388 if (ch->root_rel->client_ready)
389 GML_send_data (ch->root, msg, ch->lid_root);
391 add_buffered_data (msg, ch->root_rel);
397 * Send a buffered message to the client, for in order delivery or
398 * as result of client ACK.
400 * @param ch Channel on which to empty the message buffer.
401 * @param c Client to send to.
402 * @param fwd Is this to send FWD data?.
405 send_client_buffered_data (struct MeshChannel *ch,
406 struct MeshClient *c,
409 struct MeshReliableMessage *copy;
410 struct MeshChannelReliability *rel;
412 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_buffered_data\n");
413 rel = fwd ? ch->dest_rel : ch->root_rel;
414 if (GNUNET_NO == rel->client_ready)
416 LOG (GNUNET_ERROR_TYPE_DEBUG, "client not ready\n");
420 copy = rel->head_recv;
421 /* We never buffer channel management messages */
424 if (copy->mid == rel->mid_recv || GNUNET_NO == ch->reliable)
426 struct GNUNET_MESH_Data *msg = (struct GNUNET_MESH_Data *) ©[1];
428 LOG (GNUNET_ERROR_TYPE_DEBUG,
429 " have %u! now expecting %u\n",
430 copy->mid, rel->mid_recv + 1);
431 send_client_data (ch, msg, fwd);
434 GNUNET_CONTAINER_DLL_remove (rel->head_recv, rel->tail_recv, copy);
439 LOG (GNUNET_ERROR_TYPE_DEBUG,
440 " reliable && don't have %u, next is %u\n",
446 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_buffered_data END\n");
451 * Allow a client to send more data.
453 * In case the client was already allowed to send data, do nothing.
456 * @param fwd Is this a FWD ACK? (FWD ACKs are sent to root)
459 send_client_ack (struct MeshChannel *ch, int fwd)
461 struct MeshChannelReliability *rel = fwd ? ch->root_rel : ch->dest_rel;
463 LOG (GNUNET_ERROR_TYPE_DEBUG,
464 " sending %s ack to client on channel %s\n",
465 fwd ? "FWD" : "BCK", GMCH_2s (ch));
473 if (GNUNET_YES == rel->client_allowed)
475 LOG (GNUNET_ERROR_TYPE_DEBUG, " already allowed\n");
478 rel->client_allowed = GNUNET_YES;
480 GML_send_ack (fwd ? ch->root : ch->dest, fwd ? ch->lid_root : ch->lid_dest);
485 * Notify the root that the destination rejected the channel.
487 * @param ch Rejected channel.
490 send_client_nack (struct MeshChannel *ch)
492 if (NULL == ch->root)
497 GML_send_nack (ch->root, ch->lid_root);
502 * Destroy all reliable messages queued for a channel,
503 * during a channel destruction.
504 * Frees the reliability structure itself.
506 * @param rel Reliability data for a channel.
509 channel_rel_free_all (struct MeshChannelReliability *rel)
511 struct MeshReliableMessage *copy;
512 struct MeshReliableMessage *next;
517 for (copy = rel->head_recv; NULL != copy; copy = next)
520 GNUNET_CONTAINER_DLL_remove (rel->head_recv, rel->tail_recv, copy);
523 for (copy = rel->head_sent; NULL != copy; copy = next)
526 GNUNET_CONTAINER_DLL_remove (rel->head_sent, rel->tail_sent, copy);
529 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
530 GNUNET_SCHEDULER_cancel (rel->retry_task);
536 * Mark future messages as ACK'd.
538 * @param rel Reliability data.
539 * @param msg DataACK message with a bitfield of future ACK'd messages.
542 channel_rel_free_sent (struct MeshChannelReliability *rel,
543 const struct GNUNET_MESH_DataACK *msg)
545 struct MeshReliableMessage *copy;
546 struct MeshReliableMessage *next;
553 bitfield = msg->futures;
554 mid = ntohl (msg->mid);
555 LOG (GNUNET_ERROR_TYPE_DEBUG,
556 "free_sent_reliable %u %llX\n",
558 LOG (GNUNET_ERROR_TYPE_DEBUG,
559 " rel %p, head %p\n",
560 rel, rel->head_sent);
561 for (i = 0, copy = rel->head_sent;
562 i < 64 && NULL != copy && 0 != bitfield;
565 LOG (GNUNET_ERROR_TYPE_DEBUG,
566 " trying bit %u (mid %u)\n",
569 if (0 == (bitfield & mask))
572 LOG (GNUNET_ERROR_TYPE_DEBUG, " set!\n");
573 /* Bit was set, clear the bit from the bitfield */
576 /* The i-th bit was set. Do we have that copy? */
577 /* Skip copies with mid < target */
578 target = mid + i + 1;
579 LOG (GNUNET_ERROR_TYPE_DEBUG, " target %u\n", target);
580 while (NULL != copy && GMC_is_pid_bigger (target, copy->mid))
583 /* Did we run out of copies? (previously freed, it's ok) */
586 LOG (GNUNET_ERROR_TYPE_DEBUG, "run out of copies...\n");
590 /* Did we overshoot the target? (previously freed, it's ok) */
591 if (GMC_is_pid_bigger (copy->mid, target))
593 LOG (GNUNET_ERROR_TYPE_DEBUG, " next copy %u\n", copy->mid);
597 /* Now copy->mid == target, free it */
599 rel_message_free (copy);
602 LOG (GNUNET_ERROR_TYPE_DEBUG, "free_sent_reliable END\n");
607 * We haven't received an ACK after a certain time: restransmit the message.
609 * @param cls Closure (MeshReliableMessage with the message to restransmit)
610 * @param tc TaskContext.
613 channel_retransmit_message (void *cls,
614 const struct GNUNET_SCHEDULER_TaskContext *tc)
616 struct MeshChannelReliability *rel = cls;
617 struct MeshReliableMessage *copy;
618 struct MeshChannel *ch;
619 struct GNUNET_MESH_Data *payload;
622 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
623 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
627 copy = rel->head_sent;
634 /* Search the message to be retransmitted in the outgoing queue.
635 * Check only the queue for the connection that is going to be used,
636 * if the message is stuck in some other connection's queue we shouldn't
638 * - cancelling it and sending the new one doesn't guarantee it's delivery,
639 * the old connection could be temporary stalled or the queue happened to
640 * be long at time of insertion.
641 * - not sending the new one could cause terrible delays the old connection
644 // FIXME access to queue elements is limited
645 payload = (struct GNUNET_MESH_Data *) ©[1];
646 fwd = (rel == ch->root_rel);
647 // c = GMT_get_connection (ch->t, fwd);
648 // hop = connection_get_hop (c, fwd);
649 // for (q = hop->queue_head; NULL != q; q = q->next)
651 // if (ntohs (payload->header.type) == q->type && ch == q->ch)
653 // struct GNUNET_MESH_Data *queued_data = q->cls;
655 // if (queued_data->mid == payload->mid)
660 /* Message not found in the queue that we are going to use. */
663 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RETRANSMIT %u\n", copy->mid);
665 GMCH_send_prebuilt_message (&payload->header, ch, fwd);
666 GNUNET_STATISTICS_update (stats, "# data retransmitted", 1, GNUNET_NO);
670 // LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! ALREADY IN QUEUE %u\n", copy->mid);
673 rel->retry_timer = GNUNET_TIME_STD_BACKOFF (rel->retry_timer);
674 rel->retry_task = GNUNET_SCHEDULER_add_delayed (rel->retry_timer,
675 &channel_retransmit_message,
681 * Destroy a reliable message after it has been acknowledged, either by
682 * direct mid ACK or bitfield. Updates the appropriate data structures and
683 * timers and frees all memory.
685 * @param copy Message that is no longer needed: remote peer got it.
688 rel_message_free (struct MeshReliableMessage *copy)
690 struct MeshChannelReliability *rel;
691 struct GNUNET_TIME_Relative time;
694 time = GNUNET_TIME_absolute_get_duration (copy->timestamp);
695 rel->expected_delay.rel_value_us *= 7;
696 rel->expected_delay.rel_value_us += time.rel_value_us;
697 rel->expected_delay.rel_value_us /= 8;
699 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Freeing %u\n", copy->mid);
700 LOG (GNUNET_ERROR_TYPE_DEBUG, " n_sent %u\n", rel->n_sent);
701 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! took %s\n",
702 GNUNET_STRINGS_relative_time_to_string (time, GNUNET_NO));
703 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! new expected delay %s\n",
704 GNUNET_STRINGS_relative_time_to_string (rel->expected_delay,
706 rel->retry_timer = rel->expected_delay;
707 GNUNET_CONTAINER_DLL_remove (rel->head_sent, rel->tail_sent, copy);
713 * Confirm we got a channel create.
715 * @param ch The channel to confirm.
716 * @param fwd Should we send a FWD ACK? (going dest->root)
719 channel_send_ack (struct MeshChannel *ch, int fwd)
721 struct GNUNET_MESH_ChannelManage msg;
723 msg.header.size = htons (sizeof (msg));
724 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK);
725 LOG (GNUNET_ERROR_TYPE_DEBUG,
726 " sending channel %s ack for channel %s\n",
727 fwd ? "FWD" : "BCK", GMCH_2s (ch));
729 msg.chid = htonl (ch->gid);
730 GMCH_send_prebuilt_message (&msg.header, ch, !fwd);
735 * Notify that a channel create didn't succeed.
737 * @param ch The channel to reject.
740 channel_send_nack (struct MeshChannel *ch)
742 struct GNUNET_MESH_ChannelManage msg;
744 msg.header.size = htons (sizeof (msg));
745 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK);
746 LOG (GNUNET_ERROR_TYPE_DEBUG,
747 " sending channel NACK for channel %s\n",
750 msg.chid = htonl (ch->gid);
751 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_NO);
756 * Channel was ACK'd by remote peer, mark as ready and cancel retransmission.
758 * @param ch Channel to mark as ready.
759 * @param fwd Was the ACK message a FWD ACK? (dest->root, SYNACK)
762 channel_confirm (struct MeshChannel *ch, int fwd)
764 struct MeshChannelReliability *rel;
765 struct MeshReliableMessage *copy;
766 struct MeshReliableMessage *next;
768 LOG (GNUNET_ERROR_TYPE_DEBUG,
769 " channel confirm %s %s:%X\n",
770 fwd ? "FWD" : "BCK", GMT_2s (ch->t), ch->gid);
771 ch->state = MESH_CHANNEL_READY;
773 rel = fwd ? ch->root_rel : ch->dest_rel;
774 rel->client_ready = GNUNET_YES;
775 for (copy = rel->head_sent; NULL != copy; copy = next)
777 struct GNUNET_MessageHeader *msg;
780 msg = (struct GNUNET_MessageHeader *) ©[1];
781 if (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE)
783 rel_message_free (copy);
787 send_client_ack (ch, fwd);
789 /* In case of a FWD ACK (SYNACK) send a BCK ACK (ACK). */
791 channel_send_ack (ch, !fwd);
796 * Save a copy to retransmit in case it gets lost.
798 * Initializes all needed callbacks and timers.
800 * @param ch Channel this message goes on.
801 * @param msg Message to copy.
802 * @param fwd Is this fwd traffic?
805 channel_save_copy (struct MeshChannel *ch,
806 const struct GNUNET_MessageHeader *msg,
809 struct MeshChannelReliability *rel;
810 struct MeshReliableMessage *copy;
815 rel = fwd ? ch->root_rel : ch->dest_rel;
817 type = ntohs (msg->type);
818 size = ntohs (msg->size);
820 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SAVE %u\n", mid);
821 copy = GNUNET_malloc (sizeof (struct MeshReliableMessage) + size);
823 copy->timestamp = GNUNET_TIME_absolute_get ();
826 memcpy (©[1], msg, size);
828 LOG (GNUNET_ERROR_TYPE_DEBUG, " n_sent %u\n", rel->n_sent);
829 GNUNET_CONTAINER_DLL_insert_tail (rel->head_sent, rel->tail_sent, copy);
830 if (GNUNET_SCHEDULER_NO_TASK == rel->retry_task)
833 GNUNET_TIME_relative_multiply (rel->expected_delay,
834 MESH_RETRANSMIT_MARGIN);
836 GNUNET_SCHEDULER_add_delayed (rel->retry_timer,
837 &channel_retransmit_message,
844 * Destroy a channel and free all resources.
846 * @param ch Channel to destroy.
849 channel_destroy (struct MeshChannel *ch)
851 struct MeshClient *c;
856 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying channel %s:%u\n",
857 GMT_2s (ch->t), ch->gid);
863 GML_channel_remove (c, ch->lid_root, ch);
869 GML_channel_remove (c, ch->lid_dest, ch);
872 channel_rel_free_all (ch->root_rel);
873 channel_rel_free_all (ch->dest_rel);
875 GMT_remove_channel (ch->t, ch);
876 GNUNET_STATISTICS_update (stats, "# channels", -1, GNUNET_NO);
883 * Create a new channel.
885 * @param t Tunnel this channel is in.
886 * @param owner Client that owns the channel, NULL for foreign channels.
887 * @param lid_root Local ID for root client.
889 * @return A new initialized channel. NULL on error.
891 static struct MeshChannel *
892 channel_new (struct MeshTunnel3 *t,
893 struct MeshClient *owner,
894 MESH_ChannelNumber lid_root)
896 struct MeshChannel *ch;
898 ch = GNUNET_new (struct MeshChannel);
900 ch->lid_root = lid_root;
903 GNUNET_STATISTICS_update (stats, "# channels", 1, GNUNET_NO);
907 ch->gid = GMT_get_next_chid (t);
908 GML_channel_add (owner, lid_root, ch);
910 GMT_add_channel (t, ch);
917 * Set options in a channel, extracted from a bit flag field
919 * @param ch Channel to set options to.
920 * @param options Bit array in host byte order.
923 channel_set_options (struct MeshChannel *ch, uint32_t options)
925 ch->nobuffer = (options & GNUNET_MESH_OPTION_NOBUFFER) != 0 ?
926 GNUNET_YES : GNUNET_NO;
927 ch->reliable = (options & GNUNET_MESH_OPTION_RELIABLE) != 0 ?
928 GNUNET_YES : GNUNET_NO;
932 is_loopback (const struct MeshChannel *ch)
935 return GMT_is_loopback (ch->t);
937 return (NULL != ch->root && NULL != ch->dest);
942 * Handle a loopback message: call the appropriate handler for the message type.
944 * @param ch Channel this message is on.
945 * @param msgh Message header.
946 * @param fwd Is this FWD traffic?
949 handle_loopback (struct MeshChannel *ch,
950 const struct GNUNET_MessageHeader *msgh,
955 type = ntohs (msgh->type);
956 LOG (GNUNET_ERROR_TYPE_DEBUG,
957 "Loopback %s %s message!\n",
958 fwd ? "FWD" : "BCK", GNUNET_MESH_DEBUG_M2S (type));
962 case GNUNET_MESSAGE_TYPE_MESH_DATA:
963 /* Don't send hop ACK, wait for client to ACK */
964 GMCH_handle_data (ch, (struct GNUNET_MESH_Data *) msgh, fwd);
967 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
968 GMCH_handle_data_ack (ch, (struct GNUNET_MESH_DataACK *) msgh, fwd);
971 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
972 GMCH_handle_create (ch->t,
973 (struct GNUNET_MESH_ChannelCreate *) msgh);
976 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
978 (struct GNUNET_MESH_ChannelManage *) msgh,
982 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK:
983 GMCH_handle_nack (ch);
986 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
987 GMCH_handle_destroy (ch,
988 (struct GNUNET_MESH_ChannelManage *) msgh,
994 LOG (GNUNET_ERROR_TYPE_DEBUG,
995 "end-to-end message not known (%u)\n",
1002 /******************************************************************************/
1003 /******************************** API ***********************************/
1004 /******************************************************************************/
1010 * @param ch Channel.
1015 GMCH_get_id (const struct MeshChannel *ch)
1022 * Get the channel tunnel.
1024 * @param ch Channel to get the tunnel from.
1026 * @return tunnel of the channel.
1028 struct MeshTunnel3 *
1029 GMCH_get_tunnel (const struct MeshChannel *ch)
1036 * Get free buffer space towards the client on a specific channel.
1038 * @param ch Channel.
1039 * @param fwd Is query about FWD traffic?
1041 * @return Free buffer space [0 - 64]
1044 GMCH_get_buffer (struct MeshChannel *ch, int fwd)
1046 struct MeshChannelReliability *rel;
1048 rel = fwd ? ch->dest_rel : ch->root_rel;
1050 /* If rel is NULL it means that the end is not yet created,
1051 * most probably is a loopback channel at the point of sending
1052 * the ChannelCreate to itself.
1057 return (64 - rel->n_recv);
1062 * Get flow control status of end point: is client allow to send?
1064 * @param ch Channel.
1065 * @param fwd Is query about FWD traffic? (Request root status).
1067 * @return #GNUNET_YES if client is allowed to send us data.
1070 GMCH_get_allowed (struct MeshChannel *ch, int fwd)
1072 struct MeshChannelReliability *rel;
1074 rel = fwd ? ch->root_rel : ch->dest_rel;
1076 return rel->client_allowed;
1081 * Is the root client for this channel on this peer?
1083 * @param ch Channel.
1084 * @param fwd Is this for fwd traffic?
1086 * @return #GNUNET_YES in case it is.
1089 GMCH_is_origin (struct MeshChannel *ch, int fwd)
1091 struct MeshClient *c;
1093 c = fwd ? ch->root : ch->dest;
1099 * Is the destination client for this channel on this peer?
1101 * @param ch Channel.
1102 * @param fwd Is this for fwd traffic?
1104 * @return #GNUNET_YES in case it is.
1107 GMCH_is_terminal (struct MeshChannel *ch, int fwd)
1109 struct MeshClient *c;
1111 c = fwd ? ch->dest : ch->root;
1117 * Notify the destination client that a new incoming channel was created.
1119 * @param ch Channel that was created.
1122 GMCH_send_create (struct MeshChannel *ch)
1126 if (NULL == ch->dest)
1130 opt |= GNUNET_YES == ch->reliable ? GNUNET_MESH_OPTION_RELIABLE : 0;
1131 opt |= GNUNET_YES == ch->nobuffer ? GNUNET_MESH_OPTION_NOBUFFER : 0;
1132 GML_send_channel_create (ch->dest, ch->lid_dest, ch->port, opt,
1133 GMT_get_destination (ch->t));
1138 * Notify a client that the channel is no longer valid.
1140 * @param ch Channel that is destroyed.
1143 GMCH_send_destroy (struct MeshChannel *ch)
1145 struct GNUNET_MESH_ChannelManage msg;
1147 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY);
1148 msg.header.size = htons (sizeof (msg));
1149 msg.chid = htonl (ch->gid);
1151 /* If root is not NULL, notify.
1152 * If it's NULL, check lid_root. When a local destroy comes in, root
1153 * is set to NULL but lid_root is left untouched. In this case, do nothing,
1154 * the client is the one who reuqested the channel to be destroyed.
1156 if (NULL != ch->root)
1157 GML_send_channel_destroy (ch->root, ch->lid_root);
1158 else if (0 == ch->lid_root)
1159 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_NO);
1161 if (NULL != ch->dest)
1162 GML_send_channel_destroy (ch->dest, ch->lid_dest);
1163 else if (0 == ch->lid_dest)
1164 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_YES);
1169 * Send data on a channel.
1171 * If the destination is local, send it to client, otherwise encrypt and
1175 * @param msg Message.
1176 * @param fwd Is this a fwd (root->dest) message?
1179 GMCH_send_data (struct MeshChannel *ch,
1180 const struct GNUNET_MESH_Data *msg,
1183 if (GMCH_is_terminal (ch, fwd))
1185 GML_send_data (fwd ? ch->dest : ch->root,
1187 fwd ? ch->lid_dest : ch->lid_root);
1191 GMT_send_prebuilt_message (&msg->header, ch->t, ch, fwd);
1197 * Send an end-to-end ACK message for the most recent in-sequence payload.
1199 * If channel is not reliable, do nothing.
1201 * @param ch Channel this is about.
1202 * @param fwd Is for FWD traffic? (ACK dest->owner)
1205 GMCH_send_data_ack (struct MeshChannel *ch, int fwd)
1207 struct GNUNET_MESH_DataACK msg;
1208 struct MeshChannelReliability *rel;
1209 struct MeshReliableMessage *copy;
1214 if (GNUNET_NO == ch->reliable)
1218 rel = fwd ? ch->dest_rel : ch->root_rel;
1219 LOG (GNUNET_ERROR_TYPE_DEBUG,
1220 "send_data_ack for %u\n",
1223 type = GNUNET_MESSAGE_TYPE_MESH_DATA_ACK;
1224 msg.header.type = htons (type);
1225 msg.header.size = htons (sizeof (msg));
1226 msg.chid = htonl (ch->gid);
1227 msg.mid = htonl (rel->mid_recv - 1);
1229 for (copy = rel->head_recv; NULL != copy; copy = copy->next)
1231 if (copy->type != type)
1233 delta = copy->mid - rel->mid_recv;
1236 mask = 0x1LL << delta;
1237 msg.futures |= mask;
1238 LOG (GNUNET_ERROR_TYPE_DEBUG,
1239 " setting bit for %u (delta %u) (%llX) -> %llX\n",
1240 copy->mid, delta, mask, msg.futures);
1242 LOG (GNUNET_ERROR_TYPE_DEBUG, " final futures %llX\n", msg.futures);
1244 GMCH_send_prebuilt_message (&msg.header, ch, fwd);
1245 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_data_ack END\n");
1250 * Allow a client to send us more data, in case it was choked.
1252 * @param ch Channel.
1253 * @param fwd Is this about FWD traffic? (Root client).
1256 GMCH_allow_client (struct MeshChannel *ch, int fwd)
1258 if (MESH_CHANNEL_READY != ch->state)
1261 send_client_ack (ch, fwd);
1268 * @param ch Channel.
1271 GMCH_debug (struct MeshChannel *ch)
1275 LOG (GNUNET_ERROR_TYPE_DEBUG, "*** DEBUG NULL CHANNEL ***\n");
1278 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %s:%X (%p)\n",
1279 GMT_2s (ch->t), ch->gid, ch);
1280 LOG (GNUNET_ERROR_TYPE_DEBUG, " root %p/%p\n",
1281 ch->root, ch->root_rel);
1282 if (NULL != ch->root)
1284 LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->root));
1285 LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n",
1286 ch->root_rel->client_ready ? "YES" : "NO");
1287 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_root);
1289 LOG (GNUNET_ERROR_TYPE_DEBUG, " dest %p/%p\n",
1290 ch->dest, ch->dest_rel);
1291 if (NULL != ch->dest)
1293 LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->dest));
1294 LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n",
1295 ch->dest_rel->client_ready ? "YES" : "NO");
1296 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_dest);
1302 * Handle an ACK given by a client.
1304 * Mark client as ready and send him any buffered data we could have for him.
1306 * @param ch Channel.
1307 * @param fwd Is this a "FWD ACK"? (FWD ACKs are sent by dest and go BCK)
1310 GMCH_handle_local_ack (struct MeshChannel *ch, int fwd)
1312 struct MeshChannelReliability *rel;
1313 struct MeshClient *c;
1315 rel = fwd ? ch->dest_rel : ch->root_rel;
1316 c = fwd ? ch->dest : ch->root;
1318 rel->client_ready = GNUNET_YES;
1319 send_client_buffered_data (ch, c, fwd);
1320 if (is_loopback (ch))
1322 unsigned int buffer;
1324 buffer = GMCH_get_buffer (ch, fwd);
1326 GMCH_allow_client (ch, fwd);
1330 GMT_send_connection_acks (ch->t);
1335 * Handle data given by a client.
1337 * Check whether the client is allowed to send in this tunnel, save if channel
1338 * is reliable and send an ACK to the client if there is still buffer space
1341 * @param ch Channel.
1342 * @param c Client which sent the data.
1343 * @param message Message.
1344 * @param fwd Is this a FWD data?
1346 * @return GNUNET_OK if everything goes well, GNUNET_SYSERR in case of en error.
1349 GMCH_handle_local_data (struct MeshChannel *ch,
1350 struct MeshClient *c,
1351 struct GNUNET_MessageHeader *message,
1354 struct MeshChannelReliability *rel;
1355 struct GNUNET_MESH_Data *payload;
1356 size_t size = ntohs (message->size);
1357 uint16_t p2p_size = sizeof(struct GNUNET_MESH_Data) + size;
1358 unsigned char cbuf[p2p_size];
1360 /* Is the client in the channel? */
1368 return GNUNET_SYSERR;
1371 rel = fwd ? ch->root_rel : ch->dest_rel;
1373 rel->client_allowed = GNUNET_NO;
1375 /* Ok, everything is correct, send the message. */
1376 payload = (struct GNUNET_MESH_Data *) cbuf;
1377 payload->mid = htonl (rel->mid_send);
1379 memcpy (&payload[1], message, size);
1380 payload->header.size = htons (p2p_size);
1381 payload->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_DATA);
1382 payload->chid = htonl (ch->gid);
1383 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channel...\n");
1384 if (GNUNET_YES == ch->reliable)
1385 channel_save_copy (ch, &payload->header, fwd);
1386 GMCH_send_prebuilt_message (&payload->header, ch, fwd);
1388 if (is_loopback (ch))
1390 if (GMCH_get_buffer (ch, fwd) > 0);
1391 send_client_ack (ch, fwd);
1396 if (GMT_get_connections_buffer (ch->t) > 0)
1398 send_client_ack (ch, fwd);
1406 * Handle a channel destroy requested by a client.
1408 * Destroy the channel and the tunnel in case this was the last channel.
1410 * @param ch Channel.
1411 * @param c Client that requested the destruction (to avoid notifying him).
1414 GMCH_handle_local_destroy (struct MeshChannel *ch,
1415 struct MeshClient *c)
1417 struct MeshTunnel3 *t;
1419 /* Cleanup after the tunnel */
1422 LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is destination.\n", GML_2s (c));
1423 GML_client_delete_channel (c, ch, ch->lid_dest);
1428 LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is owner.\n", GML_2s (c));
1429 GML_client_delete_channel (c, ch, ch->lid_root);
1434 GMCH_send_destroy (ch);
1435 channel_destroy (ch);
1436 GMT_destroy_if_empty (t);
1441 * Handle a channel create requested by a client.
1443 * Create the channel and the tunnel in case this was the first0 channel.
1445 * @param c Client that requested the creation (will be the root).
1446 * @param msg Create Channel message.
1448 * @return GNUNET_OK if everything went fine, GNUNET_SYSERR otherwise.
1451 GMCH_handle_local_create (struct MeshClient *c,
1452 struct GNUNET_MESH_ChannelMessage *msg)
1454 struct MeshChannel *ch;
1455 struct MeshTunnel3 *t;
1456 struct MeshPeer *peer;
1457 MESH_ChannelNumber chid;
1459 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s:%u\n",
1460 GNUNET_i2s (&msg->peer), ntohl (msg->port));
1461 chid = ntohl (msg->channel_id);
1463 /* Sanity check for duplicate channel IDs */
1464 if (NULL != GML_channel_get (c, chid))
1467 return GNUNET_SYSERR;
1470 peer = GMP_get (&msg->peer);
1471 GMP_add_tunnel (peer);
1472 t = GMP_get_tunnel (peer);
1474 if (GMP_get_short_id (peer) == myid)
1476 GMT_change_state (t, MESH_TUNNEL3_READY);
1483 /* Create channel */
1484 ch = channel_new (t, c, chid);
1488 return GNUNET_SYSERR;
1490 ch->port = ntohl (msg->port);
1491 channel_set_options (ch, ntohl (msg->opt));
1493 /* In unreliable channels, we'll use the DLL to buffer BCK data */
1494 ch->root_rel = GNUNET_new (struct MeshChannelReliability);
1495 ch->root_rel->ch = ch;
1496 ch->root_rel->expected_delay = MESH_RETRANSMIT_TIME;
1498 LOG (GNUNET_ERROR_TYPE_DEBUG, "CREATED CHANNEL %s\n", GMCH_2s (ch));
1500 /* Send create channel */
1502 struct GNUNET_MESH_ChannelCreate msgcc;
1504 msgcc.header.size = htons (sizeof (msgcc));
1505 msgcc.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE);
1506 msgcc.chid = htonl (ch->gid);
1507 msgcc.port = msg->port;
1508 msgcc.opt = msg->opt;
1510 GMT_send_prebuilt_message (&msgcc.header, t, ch, GNUNET_YES);
1517 * Handler for mesh network payload traffic.
1519 * @param ch Channel for the message.
1520 * @param msg Unencryted data message.
1521 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1522 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1523 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1524 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1527 GMCH_handle_data (struct MeshChannel *ch,
1528 const struct GNUNET_MESH_Data *msg,
1531 struct MeshChannelReliability *rel;
1532 struct MeshClient *c;
1535 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1536 if (GNUNET_SYSERR == fwd)
1538 if (is_loopback (ch))
1540 /* It is a loopback channel after all... */
1544 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1547 /* Initialize FWD/BCK data */
1548 c = fwd ? ch->dest : ch->root;
1549 rel = fwd ? ch->dest_rel : ch->root_rel;
1557 GNUNET_STATISTICS_update (stats, "# data received", 1, GNUNET_NO);
1559 mid = ntohl (msg->mid);
1560 LOG (GNUNET_ERROR_TYPE_DEBUG, " mid %u\n", mid);
1562 if (GNUNET_NO == ch->reliable ||
1563 ( !GMC_is_pid_bigger (rel->mid_recv, mid) &&
1564 GMC_is_pid_bigger (rel->mid_recv + 64, mid) ) )
1566 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RECV %u\n", mid);
1567 if (GNUNET_YES == ch->reliable)
1569 /* Is this the exact next expected messasge? */
1570 if (mid == rel->mid_recv)
1572 LOG (GNUNET_ERROR_TYPE_DEBUG, "as expected\n");
1574 send_client_data (ch, msg, fwd);
1578 LOG (GNUNET_ERROR_TYPE_DEBUG, "save for later\n");
1579 add_buffered_data (msg, rel);
1584 /* Tunnel is unreliable: send to clients directly */
1585 /* FIXME: accept Out Of Order traffic */
1586 rel->mid_recv = mid + 1;
1587 send_client_data (ch, msg, fwd);
1592 GNUNET_break_op (0);
1593 LOG (GNUNET_ERROR_TYPE_DEBUG,
1594 " MID %u not expected (%u - %u), dropping!\n",
1595 mid, rel->mid_recv, rel->mid_recv + 64);
1598 GMCH_send_data_ack (ch, fwd);
1603 * Handler for mesh network traffic end-to-end ACKs.
1605 * @param ch Channel on which we got this message.
1606 * @param msg Data message.
1607 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1608 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1609 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1610 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1613 GMCH_handle_data_ack (struct MeshChannel *ch,
1614 const struct GNUNET_MESH_DataACK *msg,
1617 struct MeshChannelReliability *rel;
1618 struct MeshReliableMessage *copy;
1619 struct MeshReliableMessage *next;
1623 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1624 if (GNUNET_SYSERR == fwd)
1626 if (is_loopback (ch))
1628 /* It is a loopback channel after all... */
1632 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1635 ack = ntohl (msg->mid);
1636 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! %s ACK %u\n",
1637 (GNUNET_YES == fwd) ? "FWD" : "BCK", ack);
1639 if (GNUNET_YES == fwd)
1653 for (work = GNUNET_NO, copy = rel->head_sent; copy != NULL; copy = next)
1655 if (GMC_is_pid_bigger (copy->mid, ack))
1657 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! head %u, out!\n", copy->mid);
1658 channel_rel_free_sent (rel, msg);
1662 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! id %u\n", copy->mid);
1664 rel_message_free (copy);
1666 /* ACK client if needed */
1667 // channel_send_ack (t, type, GNUNET_MESSAGE_TYPE_MESH_UNICAST_ACK == type);
1669 /* If some message was free'd, update the retransmission delay*/
1670 if (GNUNET_YES == work)
1672 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
1674 GNUNET_SCHEDULER_cancel (rel->retry_task);
1675 if (NULL == rel->head_sent)
1677 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
1681 struct GNUNET_TIME_Absolute new_target;
1682 struct GNUNET_TIME_Relative delay;
1684 delay = GNUNET_TIME_relative_multiply (rel->retry_timer,
1685 MESH_RETRANSMIT_MARGIN);
1686 new_target = GNUNET_TIME_absolute_add (rel->head_sent->timestamp,
1688 delay = GNUNET_TIME_absolute_get_remaining (new_target);
1690 GNUNET_SCHEDULER_add_delayed (delay,
1691 &channel_retransmit_message,
1702 * Handler for channel create messages.
1704 * Does not have fwd parameter because it's always 'FWD': channel is incoming.
1706 * @param t Tunnel this channel will be in.
1707 * @param msg Channel crate message.
1709 struct MeshChannel *
1710 GMCH_handle_create (struct MeshTunnel3 *t,
1711 const struct GNUNET_MESH_ChannelCreate *msg)
1713 MESH_ChannelNumber chid;
1714 struct MeshChannel *ch;
1715 struct MeshClient *c;
1718 chid = ntohl (msg->chid);
1720 ch = GMT_get_channel (t, chid);
1723 /* Create channel */
1724 ch = channel_new (t, NULL, 0);
1727 channel_set_options (ch, ntohl (msg->opt));
1729 /* Find a destination client */
1730 port = ntohl (msg->port);
1731 LOG (GNUNET_ERROR_TYPE_DEBUG, " port %u\n", port);
1732 c = GML_client_get_by_port (port);
1735 /* TODO send reject */
1736 LOG (GNUNET_ERROR_TYPE_DEBUG, " no client has port registered\n");
1737 if (is_loopback (ch))
1739 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback: destroy on handler\n");
1740 channel_send_nack (ch);
1744 LOG (GNUNET_ERROR_TYPE_DEBUG, " not loopback: destroy now\n");
1745 channel_send_nack (ch);
1746 channel_destroy (ch);
1752 LOG (GNUNET_ERROR_TYPE_DEBUG, " client %p has port registered\n", c);
1755 add_destination (ch, c);
1756 if (GNUNET_YES == ch->reliable)
1757 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Reliable\n");
1759 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Not Reliable\n");
1761 GMCH_send_create (ch);
1762 channel_send_ack (ch, GNUNET_YES);
1769 * Handler for channel NACK messages.
1771 * NACK messages always go dest -> root, no need for 'fwd' or 'msg' parameter.
1773 * @param ch Channel.
1776 GMCH_handle_nack (struct MeshChannel *ch)
1778 send_client_nack (ch);
1779 channel_destroy (ch);
1784 * Handler for channel ack messages.
1786 * @param ch Channel.
1787 * @param msg Message.
1788 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1789 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1790 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1791 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1794 GMCH_handle_ack (struct MeshChannel *ch,
1795 const struct GNUNET_MESH_ChannelManage *msg,
1798 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1799 if (GNUNET_SYSERR == fwd)
1801 if (is_loopback (ch))
1803 /* It is a loopback channel after all... */
1807 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1810 channel_confirm (ch, !fwd);
1815 * Handler for channel destroy messages.
1817 * @param ch Channel to be destroyed of.
1818 * @param msg Message.
1819 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1820 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1821 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1822 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1825 GMCH_handle_destroy (struct MeshChannel *ch,
1826 const struct GNUNET_MESH_ChannelManage *msg,
1829 struct MeshTunnel3 *t;
1831 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1832 if (GNUNET_SYSERR == fwd)
1834 if (is_loopback (ch))
1836 /* It is a loopback channel after all... */
1840 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1844 if ( (fwd && NULL == ch->dest) || (!fwd && NULL == ch->root) )
1846 /* Not for us (don't destroy twice a half-open loopback channel) */
1851 GMCH_send_destroy (ch);
1852 channel_destroy (ch);
1853 GMT_destroy_if_empty (t);
1858 * Sends an already built message on a channel.
1860 * If the channel is on a loopback tunnel, notifies the appropriate destination
1863 * On a normal channel passes the message to the tunnel for encryption and
1864 * sending on a connection.
1866 * This function DOES NOT save the message for retransmission.
1868 * @param message Message to send. Function makes a copy of it.
1869 * @param ch Channel on which this message is transmitted.
1870 * @param fwd Is this a fwd message?
1873 GMCH_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1874 struct MeshChannel *ch, int fwd)
1876 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMCH Send %s %s on channel %s\n",
1877 fwd ? "FWD" : "BCK", GNUNET_MESH_DEBUG_M2S (ntohs (message->type)),
1880 if (GMT_is_loopback (ch->t))
1882 handle_loopback (ch, message, fwd);
1886 GMT_send_prebuilt_message (message, ch->t, ch, fwd);
1891 * Get the static string for identification of the channel.
1893 * @param ch Channel.
1895 * @return Static string with the channel IDs.
1898 GMCH_2s (const struct MeshChannel *ch)
1900 static char buf[64];
1903 return "(NULL Channel)";
1905 sprintf (buf, "%s:%X (%X / %X)",
1906 GMT_2s (ch->t), ch->gid, ch->lid_root, ch->lid_dest);