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)
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 * DLL of messages received out of order.
118 struct MeshReliableMessage *head_recv;
119 struct MeshReliableMessage *tail_recv;
127 * Next MID to use for outgoing traffic.
132 * Next MID expected for incoming traffic.
137 * Can we send data to the client?
142 * Can the client send data to us?
147 * Task to resend/poll in case no ACK is received.
149 GNUNET_SCHEDULER_TaskIdentifier retry_task;
152 * Counter for exponential backoff.
154 struct GNUNET_TIME_Relative retry_timer;
157 * How long does it usually take to get an ACK.
159 struct GNUNET_TIME_Relative expected_delay;
164 * Struct containing all information regarding a channel to a remote client.
169 * Tunnel this channel is in.
171 struct MeshTunnel3 *t;
174 * Destination port of the channel.
179 * Global channel number ( < GNUNET_MESH_LOCAL_CHANNEL_ID_CLI)
181 MESH_ChannelNumber gid;
184 * Local tunnel number for root (owner) client.
185 * ( >= GNUNET_MESH_LOCAL_CHANNEL_ID_CLI or 0 )
187 MESH_ChannelNumber lid_root;
190 * Local tunnel number for local destination clients (incoming number)
191 * ( >= GNUNET_MESH_LOCAL_CHANNEL_ID_SERV or 0).
193 MESH_ChannelNumber lid_dest;
198 enum MeshChannelState state;
201 * Is the tunnel bufferless (minimum latency)?
206 * Is the tunnel reliable?
211 * Last time the channel was used
213 struct GNUNET_TIME_Absolute timestamp;
216 * Client owner of the tunnel, if any
218 struct MeshClient *root;
221 * Client destination of the tunnel, if any.
223 struct MeshClient *dest;
226 * Flag to signal the destruction of the channel.
227 * If this is set GNUNET_YES the channel will be destroyed
228 * when the queue is empty.
233 * Total messages pending for this channel, payload or not.
235 unsigned int pending_messages;
239 * Only present (non-NULL) at the owner of a tunnel.
241 struct MeshChannelReliability *root_rel;
245 * Only present (non-NULL) at the destination of a tunnel.
247 struct MeshChannelReliability *dest_rel;
252 /******************************************************************************/
253 /******************************* GLOBALS ***********************************/
254 /******************************************************************************/
257 * Global handle to the statistics service.
259 extern struct GNUNET_STATISTICS_Handle *stats;
262 * Local peer own ID (memory efficient handle).
264 extern GNUNET_PEER_Id myid;
267 /******************************************************************************/
268 /******************************** STATIC ***********************************/
269 /******************************************************************************/
272 * Destroy a reliable message after it has been acknowledged, either by
273 * direct mid ACK or bitfield. Updates the appropriate data structures and
274 * timers and frees all memory.
276 * @param copy Message that is no longer needed: remote peer got it.
277 * @param update_time Is the timing information relevant?
278 * If this message is ACK in a batch the timing information
279 * is skewed by the retransmission, count only for the
280 * retransmitted message.
283 rel_message_free (struct MeshReliableMessage *copy, int update_time);
286 * We have received a message out of order, or the client is not ready.
287 * Buffer it until we receive an ACK from the client or the missing
288 * message from the channel.
290 * @param msg Message to buffer (MUST be of type MESH_DATA).
291 * @param rel Reliability data to the corresponding direction.
294 add_buffered_data (const struct GNUNET_MESH_Data *msg,
295 struct MeshChannelReliability *rel)
297 struct MeshReliableMessage *copy;
298 struct MeshReliableMessage *prev;
302 size = ntohs (msg->header.size);
303 mid = ntohl (msg->mid);
305 LOG (GNUNET_ERROR_TYPE_DEBUG, "add_buffered_data %u\n", mid);
307 copy = GNUNET_malloc (sizeof (*copy) + size);
310 copy->type = GNUNET_MESSAGE_TYPE_MESH_DATA;
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, GNUNET_YES);
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 copy->timestamp = GNUNET_TIME_absolute_get();
674 rel->retry_timer = GNUNET_TIME_STD_BACKOFF (rel->retry_timer);
675 rel->retry_task = GNUNET_SCHEDULER_add_delayed (rel->retry_timer,
676 &channel_retransmit_message,
682 * Destroy a reliable message after it has been acknowledged, either by
683 * direct mid ACK or bitfield. Updates the appropriate data structures and
684 * timers and frees all memory.
686 * @param copy Message that is no longer needed: remote peer got it.
687 * @param update_time Is the timing information relevant?
688 * If this message is ACK in a batch the timing information
689 * is skewed by the retransmission, count only for the
690 * retransmitted message.
693 rel_message_free (struct MeshReliableMessage *copy, int update_time)
695 struct MeshChannelReliability *rel;
696 struct GNUNET_TIME_Relative time;
699 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Freeing %u\n", copy->mid);
702 time = GNUNET_TIME_absolute_get_duration (copy->timestamp);
703 rel->expected_delay.rel_value_us *= 7;
704 rel->expected_delay.rel_value_us += time.rel_value_us;
705 rel->expected_delay.rel_value_us /= 8;
706 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! took %s\n",
707 GNUNET_STRINGS_relative_time_to_string (time, GNUNET_NO));
708 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! new expected delay %s\n",
709 GNUNET_STRINGS_relative_time_to_string (rel->expected_delay,
711 rel->retry_timer = rel->expected_delay;
715 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! batch free, ignoring timing\n");
717 GNUNET_CONTAINER_DLL_remove (rel->head_sent, rel->tail_sent, copy);
723 * Confirm we got a channel create.
725 * @param ch The channel to confirm.
726 * @param fwd Should we send a FWD ACK? (going dest->root)
729 channel_send_ack (struct MeshChannel *ch, int fwd)
731 struct GNUNET_MESH_ChannelManage msg;
733 msg.header.size = htons (sizeof (msg));
734 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK);
735 LOG (GNUNET_ERROR_TYPE_DEBUG,
736 " sending channel %s ack for channel %s\n",
737 fwd ? "FWD" : "BCK", GMCH_2s (ch));
739 msg.chid = htonl (ch->gid);
740 GMCH_send_prebuilt_message (&msg.header, ch, !fwd);
745 * Notify that a channel create didn't succeed.
747 * @param ch The channel to reject.
750 channel_send_nack (struct MeshChannel *ch)
752 struct GNUNET_MESH_ChannelManage msg;
754 msg.header.size = htons (sizeof (msg));
755 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK);
756 LOG (GNUNET_ERROR_TYPE_DEBUG,
757 " sending channel NACK for channel %s\n",
760 msg.chid = htonl (ch->gid);
761 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_NO);
766 * Channel was ACK'd by remote peer, mark as ready and cancel retransmission.
768 * @param ch Channel to mark as ready.
769 * @param fwd Was the ACK message a FWD ACK? (dest->root, SYNACK)
772 channel_confirm (struct MeshChannel *ch, int fwd)
774 struct MeshChannelReliability *rel;
775 struct MeshReliableMessage *copy;
776 struct MeshReliableMessage *next;
778 LOG (GNUNET_ERROR_TYPE_DEBUG,
779 " channel confirm %s %s:%X\n",
780 fwd ? "FWD" : "BCK", GMT_2s (ch->t), ch->gid);
781 ch->state = MESH_CHANNEL_READY;
783 rel = fwd ? ch->root_rel : ch->dest_rel;
784 rel->client_ready = GNUNET_YES;
785 for (copy = rel->head_sent; NULL != copy; copy = next)
787 struct GNUNET_MessageHeader *msg;
790 msg = (struct GNUNET_MessageHeader *) ©[1];
791 if (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE)
793 rel_message_free (copy, GNUNET_YES);
797 send_client_ack (ch, fwd);
799 /* In case of a FWD ACK (SYNACK) send a BCK ACK (ACK). */
801 channel_send_ack (ch, !fwd);
806 * Save a copy to retransmit in case it gets lost.
808 * Initializes all needed callbacks and timers.
810 * @param ch Channel this message goes on.
811 * @param msg Message to copy.
812 * @param fwd Is this fwd traffic?
815 channel_save_copy (struct MeshChannel *ch,
816 const struct GNUNET_MessageHeader *msg,
819 struct MeshChannelReliability *rel;
820 struct MeshReliableMessage *copy;
825 rel = fwd ? ch->root_rel : ch->dest_rel;
826 mid = rel->mid_send - 1;
827 type = ntohs (msg->type);
828 size = ntohs (msg->size);
830 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SAVE %u %s\n",
831 mid, GNUNET_MESH_DEBUG_M2S (type));
832 copy = GNUNET_malloc (sizeof (struct MeshReliableMessage) + size);
834 copy->timestamp = GNUNET_TIME_absolute_get ();
837 memcpy (©[1], msg, size);
838 GNUNET_CONTAINER_DLL_insert_tail (rel->head_sent, rel->tail_sent, copy);
839 if (GNUNET_SCHEDULER_NO_TASK == rel->retry_task)
842 GNUNET_TIME_relative_multiply (rel->expected_delay,
843 MESH_RETRANSMIT_MARGIN);
845 GNUNET_SCHEDULER_add_delayed (rel->retry_timer,
846 &channel_retransmit_message,
853 * Destroy a channel and free all resources.
855 * @param ch Channel to destroy.
858 channel_destroy (struct MeshChannel *ch)
860 struct MeshClient *c;
865 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying channel %s:%u\n",
866 GMT_2s (ch->t), ch->gid);
872 GML_channel_remove (c, ch->lid_root, ch);
878 GML_channel_remove (c, ch->lid_dest, ch);
881 channel_rel_free_all (ch->root_rel);
882 channel_rel_free_all (ch->dest_rel);
884 GMT_remove_channel (ch->t, ch);
885 GNUNET_STATISTICS_update (stats, "# channels", -1, GNUNET_NO);
892 * Create a new channel.
894 * @param t Tunnel this channel is in.
895 * @param owner Client that owns the channel, NULL for foreign channels.
896 * @param lid_root Local ID for root client.
898 * @return A new initialized channel. NULL on error.
900 static struct MeshChannel *
901 channel_new (struct MeshTunnel3 *t,
902 struct MeshClient *owner,
903 MESH_ChannelNumber lid_root)
905 struct MeshChannel *ch;
907 ch = GNUNET_new (struct MeshChannel);
909 ch->lid_root = lid_root;
912 GNUNET_STATISTICS_update (stats, "# channels", 1, GNUNET_NO);
916 ch->gid = GMT_get_next_chid (t);
917 GML_channel_add (owner, lid_root, ch);
919 GMT_add_channel (t, ch);
926 * Set options in a channel, extracted from a bit flag field
928 * @param ch Channel to set options to.
929 * @param options Bit array in host byte order.
932 channel_set_options (struct MeshChannel *ch, uint32_t options)
934 ch->nobuffer = (options & GNUNET_MESH_OPTION_NOBUFFER) != 0 ?
935 GNUNET_YES : GNUNET_NO;
936 ch->reliable = (options & GNUNET_MESH_OPTION_RELIABLE) != 0 ?
937 GNUNET_YES : GNUNET_NO;
941 is_loopback (const struct MeshChannel *ch)
944 return GMT_is_loopback (ch->t);
946 return (NULL != ch->root && NULL != ch->dest);
951 * Handle a loopback message: call the appropriate handler for the message type.
953 * @param ch Channel this message is on.
954 * @param msgh Message header.
955 * @param fwd Is this FWD traffic?
958 handle_loopback (struct MeshChannel *ch,
959 const struct GNUNET_MessageHeader *msgh,
964 type = ntohs (msgh->type);
965 LOG (GNUNET_ERROR_TYPE_DEBUG,
966 "Loopback %s %s message!\n",
967 fwd ? "FWD" : "BCK", GNUNET_MESH_DEBUG_M2S (type));
971 case GNUNET_MESSAGE_TYPE_MESH_DATA:
972 /* Don't send hop ACK, wait for client to ACK */
973 GMCH_handle_data (ch, (struct GNUNET_MESH_Data *) msgh, fwd);
976 case GNUNET_MESSAGE_TYPE_MESH_DATA_ACK:
977 GMCH_handle_data_ack (ch, (struct GNUNET_MESH_DataACK *) msgh, fwd);
980 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
981 GMCH_handle_create (ch->t,
982 (struct GNUNET_MESH_ChannelCreate *) msgh);
985 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
987 (struct GNUNET_MESH_ChannelManage *) msgh,
991 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK:
992 GMCH_handle_nack (ch);
995 case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
996 GMCH_handle_destroy (ch,
997 (struct GNUNET_MESH_ChannelManage *) msgh,
1002 GNUNET_break_op (0);
1003 LOG (GNUNET_ERROR_TYPE_DEBUG,
1004 "end-to-end message not known (%u)\n",
1005 ntohs (msgh->type));
1011 /******************************************************************************/
1012 /******************************** API ***********************************/
1013 /******************************************************************************/
1019 * @param ch Channel.
1024 GMCH_get_id (const struct MeshChannel *ch)
1031 * Get the channel tunnel.
1033 * @param ch Channel to get the tunnel from.
1035 * @return tunnel of the channel.
1037 struct MeshTunnel3 *
1038 GMCH_get_tunnel (const struct MeshChannel *ch)
1045 * Get free buffer space towards the client on a specific channel.
1047 * @param ch Channel.
1048 * @param fwd Is query about FWD traffic?
1050 * @return Free buffer space [0 - 64]
1053 GMCH_get_buffer (struct MeshChannel *ch, int fwd)
1055 struct MeshChannelReliability *rel;
1057 rel = fwd ? ch->dest_rel : ch->root_rel;
1059 /* If rel is NULL it means that the end is not yet created,
1060 * most probably is a loopback channel at the point of sending
1061 * the ChannelCreate to itself.
1066 return (64 - rel->n_recv);
1071 * Get flow control status of end point: is client allow to send?
1073 * @param ch Channel.
1074 * @param fwd Is query about FWD traffic? (Request root status).
1076 * @return #GNUNET_YES if client is allowed to send us data.
1079 GMCH_get_allowed (struct MeshChannel *ch, int fwd)
1081 struct MeshChannelReliability *rel;
1083 rel = fwd ? ch->root_rel : ch->dest_rel;
1085 return rel->client_allowed;
1090 * Is the root client for this channel on this peer?
1092 * @param ch Channel.
1093 * @param fwd Is this for fwd traffic?
1095 * @return #GNUNET_YES in case it is.
1098 GMCH_is_origin (struct MeshChannel *ch, int fwd)
1100 struct MeshClient *c;
1102 c = fwd ? ch->root : ch->dest;
1108 * Is the destination client for this channel on this peer?
1110 * @param ch Channel.
1111 * @param fwd Is this for fwd traffic?
1113 * @return #GNUNET_YES in case it is.
1116 GMCH_is_terminal (struct MeshChannel *ch, int fwd)
1118 struct MeshClient *c;
1120 c = fwd ? ch->dest : ch->root;
1126 * Notify the destination client that a new incoming channel was created.
1128 * @param ch Channel that was created.
1131 GMCH_send_create (struct MeshChannel *ch)
1135 if (NULL == ch->dest)
1139 opt |= GNUNET_YES == ch->reliable ? GNUNET_MESH_OPTION_RELIABLE : 0;
1140 opt |= GNUNET_YES == ch->nobuffer ? GNUNET_MESH_OPTION_NOBUFFER : 0;
1141 GML_send_channel_create (ch->dest, ch->lid_dest, ch->port, opt,
1142 GMT_get_destination (ch->t));
1147 * Notify a client that the channel is no longer valid.
1149 * @param ch Channel that is destroyed.
1152 GMCH_send_destroy (struct MeshChannel *ch)
1154 struct GNUNET_MESH_ChannelManage msg;
1156 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY);
1157 msg.header.size = htons (sizeof (msg));
1158 msg.chid = htonl (ch->gid);
1160 /* If root is not NULL, notify.
1161 * If it's NULL, check lid_root. When a local destroy comes in, root
1162 * is set to NULL but lid_root is left untouched. In this case, do nothing,
1163 * the client is the one who reuqested the channel to be destroyed.
1165 if (NULL != ch->root)
1166 GML_send_channel_destroy (ch->root, ch->lid_root);
1167 else if (0 == ch->lid_root)
1168 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_NO);
1170 if (NULL != ch->dest)
1171 GML_send_channel_destroy (ch->dest, ch->lid_dest);
1172 else if (0 == ch->lid_dest)
1173 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_YES);
1178 * Send data on a channel.
1180 * If the destination is local, send it to client, otherwise encrypt and
1184 * @param msg Message.
1185 * @param fwd Is this a fwd (root->dest) message?
1188 GMCH_send_data (struct MeshChannel *ch,
1189 const struct GNUNET_MESH_Data *msg,
1192 if (GMCH_is_terminal (ch, fwd))
1194 GML_send_data (fwd ? ch->dest : ch->root,
1196 fwd ? ch->lid_dest : ch->lid_root);
1200 GMT_send_prebuilt_message (&msg->header, ch->t, ch, fwd);
1206 * Send an end-to-end ACK message for the most recent in-sequence payload.
1208 * If channel is not reliable, do nothing.
1210 * @param ch Channel this is about.
1211 * @param fwd Is for FWD traffic? (ACK dest->owner)
1214 GMCH_send_data_ack (struct MeshChannel *ch, int fwd)
1216 struct GNUNET_MESH_DataACK msg;
1217 struct MeshChannelReliability *rel;
1218 struct MeshReliableMessage *copy;
1223 if (GNUNET_NO == ch->reliable)
1227 rel = fwd ? ch->dest_rel : ch->root_rel;
1228 ack = rel->mid_recv - 1;
1229 LOG (GNUNET_ERROR_TYPE_DEBUG,
1230 " !! Send DATA_ACK for %u\n",
1233 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_DATA_ACK);
1234 msg.header.size = htons (sizeof (msg));
1235 msg.chid = htonl (ch->gid);
1237 for (copy = rel->head_recv; NULL != copy; copy = copy->next)
1239 if (copy->type != GNUNET_MESSAGE_TYPE_MESH_DATA)
1241 LOG (GNUNET_ERROR_TYPE_DEBUG,
1242 "!! Type %s, expected DATA\n",
1243 GNUNET_MESH_DEBUG_M2S (copy->type));
1246 if (copy->mid == ack + 1)
1251 delta = copy->mid - (ack + 1);
1254 mask = 0x1LL << delta;
1255 msg.futures |= mask;
1256 LOG (GNUNET_ERROR_TYPE_DEBUG,
1257 " !! setting bit for %u (delta %u) (%llX) -> %llX\n",
1258 copy->mid, delta, mask, msg.futures);
1260 msg.mid = htonl (ack);
1261 LOG (GNUNET_ERROR_TYPE_DEBUG,
1262 "!!! ACK for %u, futures %llX\n",
1265 GMCH_send_prebuilt_message (&msg.header, ch, !fwd);
1266 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_data_ack END\n");
1271 * Allow a client to send us more data, in case it was choked.
1273 * @param ch Channel.
1274 * @param fwd Is this about FWD traffic? (Root client).
1277 GMCH_allow_client (struct MeshChannel *ch, int fwd)
1279 struct MeshChannelReliability *rel;
1280 unsigned int buffer;
1282 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMCH allow\n");
1284 if (MESH_CHANNEL_READY != ch->state)
1286 LOG (GNUNET_ERROR_TYPE_DEBUG, " channel not ready yet!\n");
1290 if (GNUNET_YES == ch->reliable)
1292 rel = fwd ? ch->root_rel : ch->dest_rel;
1298 if (NULL != rel->head_sent && 64 <= rel->mid_send - rel->head_sent->mid)
1300 LOG (GNUNET_ERROR_TYPE_DEBUG, " too big MID gap! Wait for ACK.\n");
1305 if (is_loopback (ch))
1306 buffer = GMCH_get_buffer (ch, fwd);
1308 buffer = GMT_get_connections_buffer (ch->t);
1312 LOG (GNUNET_ERROR_TYPE_DEBUG, " no buffer space.\n");
1316 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space %u, allowing\n", buffer);
1317 send_client_ack (ch, fwd);
1324 * @param ch Channel.
1327 GMCH_debug (struct MeshChannel *ch)
1331 LOG (GNUNET_ERROR_TYPE_DEBUG, "*** DEBUG NULL CHANNEL ***\n");
1334 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %s:%X (%p)\n",
1335 GMT_2s (ch->t), ch->gid, ch);
1336 LOG (GNUNET_ERROR_TYPE_DEBUG, " root %p/%p\n",
1337 ch->root, ch->root_rel);
1338 if (NULL != ch->root)
1340 LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->root));
1341 LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n",
1342 ch->root_rel->client_ready ? "YES" : "NO");
1343 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_root);
1345 LOG (GNUNET_ERROR_TYPE_DEBUG, " dest %p/%p\n",
1346 ch->dest, ch->dest_rel);
1347 if (NULL != ch->dest)
1349 LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->dest));
1350 LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n",
1351 ch->dest_rel->client_ready ? "YES" : "NO");
1352 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_dest);
1358 * Handle an ACK given by a client.
1360 * Mark client as ready and send him any buffered data we could have for him.
1362 * @param ch Channel.
1363 * @param fwd Is this a "FWD ACK"? (FWD ACKs are sent by dest and go BCK)
1366 GMCH_handle_local_ack (struct MeshChannel *ch, int fwd)
1368 struct MeshChannelReliability *rel;
1369 struct MeshClient *c;
1371 rel = fwd ? ch->dest_rel : ch->root_rel;
1372 c = fwd ? ch->dest : ch->root;
1374 rel->client_ready = GNUNET_YES;
1375 send_client_buffered_data (ch, c, fwd);
1376 if (is_loopback (ch))
1378 unsigned int buffer;
1380 buffer = GMCH_get_buffer (ch, fwd);
1382 GMCH_allow_client (ch, fwd);
1386 GMT_send_connection_acks (ch->t);
1391 * Handle data given by a client.
1393 * Check whether the client is allowed to send in this tunnel, save if channel
1394 * is reliable and send an ACK to the client if there is still buffer space
1397 * @param ch Channel.
1398 * @param c Client which sent the data.
1399 * @param message Message.
1400 * @param fwd Is this a FWD data?
1402 * @return GNUNET_OK if everything goes well, GNUNET_SYSERR in case of en error.
1405 GMCH_handle_local_data (struct MeshChannel *ch,
1406 struct MeshClient *c,
1407 struct GNUNET_MessageHeader *message,
1410 struct MeshChannelReliability *rel;
1411 struct GNUNET_MESH_Data *payload;
1412 size_t size = ntohs (message->size);
1413 uint16_t p2p_size = sizeof(struct GNUNET_MESH_Data) + size;
1414 unsigned char cbuf[p2p_size];
1416 /* Is the client in the channel? */
1423 GNUNET_break_op (0);
1424 return GNUNET_SYSERR;
1427 rel = fwd ? ch->root_rel : ch->dest_rel;
1429 if (GNUNET_NO == rel->client_allowed)
1431 GNUNET_break_op (0);
1432 return GNUNET_SYSERR;
1435 rel->client_allowed = GNUNET_NO;
1437 /* Ok, everything is correct, send the message. */
1438 payload = (struct GNUNET_MESH_Data *) cbuf;
1439 payload->mid = htonl (rel->mid_send);
1441 memcpy (&payload[1], message, size);
1442 payload->header.size = htons (p2p_size);
1443 payload->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_DATA);
1444 payload->chid = htonl (ch->gid);
1445 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channel...\n");
1446 if (GNUNET_YES == ch->reliable)
1447 channel_save_copy (ch, &payload->header, fwd);
1448 GMCH_send_prebuilt_message (&payload->header, ch, fwd);
1450 if (is_loopback (ch))
1452 if (GMCH_get_buffer (ch, fwd) > 0)
1453 send_client_ack (ch, fwd);
1458 if (GMT_get_connections_buffer (ch->t) > 0)
1460 send_client_ack (ch, fwd);
1468 * Handle a channel destroy requested by a client.
1470 * Destroy the channel and the tunnel in case this was the last channel.
1472 * @param ch Channel.
1473 * @param c Client that requested the destruction (to avoid notifying him).
1476 GMCH_handle_local_destroy (struct MeshChannel *ch,
1477 struct MeshClient *c)
1479 struct MeshTunnel3 *t;
1481 /* Cleanup after the tunnel */
1484 LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is destination.\n", GML_2s (c));
1485 GML_client_delete_channel (c, ch, ch->lid_dest);
1490 LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is owner.\n", GML_2s (c));
1491 GML_client_delete_channel (c, ch, ch->lid_root);
1496 GMCH_send_destroy (ch);
1497 channel_destroy (ch);
1498 GMT_destroy_if_empty (t);
1503 * Handle a channel create requested by a client.
1505 * Create the channel and the tunnel in case this was the first0 channel.
1507 * @param c Client that requested the creation (will be the root).
1508 * @param msg Create Channel message.
1510 * @return GNUNET_OK if everything went fine, GNUNET_SYSERR otherwise.
1513 GMCH_handle_local_create (struct MeshClient *c,
1514 struct GNUNET_MESH_ChannelMessage *msg)
1516 struct MeshChannel *ch;
1517 struct MeshTunnel3 *t;
1518 struct MeshPeer *peer;
1519 MESH_ChannelNumber chid;
1521 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s:%u\n",
1522 GNUNET_i2s (&msg->peer), ntohl (msg->port));
1523 chid = ntohl (msg->channel_id);
1525 /* Sanity check for duplicate channel IDs */
1526 if (NULL != GML_channel_get (c, chid))
1529 return GNUNET_SYSERR;
1532 peer = GMP_get (&msg->peer);
1533 GMP_add_tunnel (peer);
1534 t = GMP_get_tunnel (peer);
1536 if (GMP_get_short_id (peer) == myid)
1538 GMT_change_state (t, MESH_TUNNEL3_READY);
1545 /* Create channel */
1546 ch = channel_new (t, c, chid);
1550 return GNUNET_SYSERR;
1552 ch->port = ntohl (msg->port);
1553 channel_set_options (ch, ntohl (msg->opt));
1555 /* In unreliable channels, we'll use the DLL to buffer BCK data */
1556 ch->root_rel = GNUNET_new (struct MeshChannelReliability);
1557 ch->root_rel->ch = ch;
1558 ch->root_rel->expected_delay = MESH_RETRANSMIT_TIME;
1560 LOG (GNUNET_ERROR_TYPE_DEBUG, "CREATED CHANNEL %s\n", GMCH_2s (ch));
1562 /* Send create channel */
1564 struct GNUNET_MESH_ChannelCreate msgcc;
1566 msgcc.header.size = htons (sizeof (msgcc));
1567 msgcc.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE);
1568 msgcc.chid = htonl (ch->gid);
1569 msgcc.port = msg->port;
1570 msgcc.opt = msg->opt;
1572 GMT_send_prebuilt_message (&msgcc.header, t, ch, GNUNET_YES);
1579 * Handler for mesh network payload traffic.
1581 * @param ch Channel for the message.
1582 * @param msg Unencryted data message.
1583 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1584 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1585 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1586 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1589 GMCH_handle_data (struct MeshChannel *ch,
1590 const struct GNUNET_MESH_Data *msg,
1593 struct MeshChannelReliability *rel;
1594 struct MeshClient *c;
1597 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1598 if (GNUNET_SYSERR == fwd)
1600 if (is_loopback (ch))
1602 /* It is a loopback channel after all... */
1606 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1609 /* Initialize FWD/BCK data */
1610 c = fwd ? ch->dest : ch->root;
1611 rel = fwd ? ch->dest_rel : ch->root_rel;
1619 GNUNET_STATISTICS_update (stats, "# data received", 1, GNUNET_NO);
1621 mid = ntohl (msg->mid);
1622 LOG (GNUNET_ERROR_TYPE_DEBUG, "!! got mid %u\n", mid);
1624 if (GNUNET_NO == ch->reliable ||
1625 ( !GMC_is_pid_bigger (rel->mid_recv, mid) &&
1626 GMC_is_pid_bigger (rel->mid_recv + 64, mid) ) )
1628 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RECV %u\n", mid);
1629 if (GNUNET_YES == ch->reliable)
1631 /* Is this the exact next expected messasge? */
1632 if (mid == rel->mid_recv)
1634 LOG (GNUNET_ERROR_TYPE_DEBUG, "as expected\n");
1636 send_client_data (ch, msg, fwd);
1640 LOG (GNUNET_ERROR_TYPE_DEBUG, "save for later\n");
1641 add_buffered_data (msg, rel);
1646 /* Tunnel is unreliable: send to clients directly */
1647 /* FIXME: accept Out Of Order traffic */
1648 rel->mid_recv = mid + 1;
1649 send_client_data (ch, msg, fwd);
1654 GNUNET_break_op (0);
1655 LOG (GNUNET_ERROR_TYPE_DEBUG,
1656 " MID %u not expected (%u - %u), dropping!\n",
1657 mid, rel->mid_recv, rel->mid_recv + 63);
1660 GMCH_send_data_ack (ch, fwd);
1665 * Handler for mesh network traffic end-to-end ACKs.
1667 * @param ch Channel on which we got this message.
1668 * @param msg Data message.
1669 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1670 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1671 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1672 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1675 GMCH_handle_data_ack (struct MeshChannel *ch,
1676 const struct GNUNET_MESH_DataACK *msg,
1679 struct MeshChannelReliability *rel;
1680 struct MeshReliableMessage *copy;
1681 struct MeshReliableMessage *next;
1685 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1686 if (GNUNET_SYSERR == fwd)
1688 if (is_loopback (ch))
1690 /* It is a loopback channel after all... */
1694 /* Inverted: if message came 'FWD' is a 'BCK ACK'. */
1695 fwd = (NULL != ch->dest) ? GNUNET_NO : GNUNET_YES;
1698 ack = ntohl (msg->mid);
1699 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! %s ACK %u\n",
1700 (GNUNET_YES == fwd) ? "FWD" : "BCK", ack);
1702 if (GNUNET_YES == fwd)
1712 GNUNET_break_op (0);
1716 /* Free ACK'd copies: no need to retransmit those anymore */
1717 for (work = GNUNET_NO, copy = rel->head_sent; copy != NULL; copy = next)
1719 if (GMC_is_pid_bigger (copy->mid, ack))
1721 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! head %u, out!\n", copy->mid);
1722 channel_rel_free_sent (rel, msg);
1726 LOG (GNUNET_ERROR_TYPE_DEBUG, " !! id %u\n", copy->mid);
1728 rel_message_free (copy, GNUNET_YES);
1731 /* ACK client if needed */
1732 GMCH_allow_client (ch, fwd);
1734 /* If some message was free'd, update the retransmission delay */
1735 if (GNUNET_YES == work)
1737 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
1739 GNUNET_SCHEDULER_cancel (rel->retry_task);
1740 if (NULL == rel->head_sent)
1742 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
1746 struct GNUNET_TIME_Absolute new_target;
1747 struct GNUNET_TIME_Relative delay;
1749 delay = GNUNET_TIME_relative_multiply (rel->retry_timer,
1750 MESH_RETRANSMIT_MARGIN);
1751 new_target = GNUNET_TIME_absolute_add (rel->head_sent->timestamp,
1753 delay = GNUNET_TIME_absolute_get_remaining (new_target);
1755 GNUNET_SCHEDULER_add_delayed (delay,
1756 &channel_retransmit_message,
1767 * Handler for channel create messages.
1769 * Does not have fwd parameter because it's always 'FWD': channel is incoming.
1771 * @param t Tunnel this channel will be in.
1772 * @param msg Channel crate message.
1774 struct MeshChannel *
1775 GMCH_handle_create (struct MeshTunnel3 *t,
1776 const struct GNUNET_MESH_ChannelCreate *msg)
1778 MESH_ChannelNumber chid;
1779 struct MeshChannel *ch;
1780 struct MeshClient *c;
1783 chid = ntohl (msg->chid);
1785 ch = GMT_get_channel (t, chid);
1788 /* Create channel */
1789 ch = channel_new (t, NULL, 0);
1792 channel_set_options (ch, ntohl (msg->opt));
1794 /* Find a destination client */
1795 port = ntohl (msg->port);
1796 LOG (GNUNET_ERROR_TYPE_DEBUG, " port %u\n", port);
1797 c = GML_client_get_by_port (port);
1800 /* TODO send reject */
1801 LOG (GNUNET_ERROR_TYPE_DEBUG, " no client has port registered\n");
1802 if (is_loopback (ch))
1804 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback: destroy on handler\n");
1805 channel_send_nack (ch);
1809 LOG (GNUNET_ERROR_TYPE_DEBUG, " not loopback: destroy now\n");
1810 channel_send_nack (ch);
1811 channel_destroy (ch);
1817 LOG (GNUNET_ERROR_TYPE_DEBUG, " client %p has port registered\n", c);
1820 add_destination (ch, c);
1821 if (GNUNET_YES == ch->reliable)
1822 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Reliable\n");
1824 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Not Reliable\n");
1826 GMCH_send_create (ch);
1827 channel_send_ack (ch, GNUNET_YES);
1834 * Handler for channel NACK messages.
1836 * NACK messages always go dest -> root, no need for 'fwd' or 'msg' parameter.
1838 * @param ch Channel.
1841 GMCH_handle_nack (struct MeshChannel *ch)
1843 send_client_nack (ch);
1844 channel_destroy (ch);
1849 * Handler for channel ack messages.
1851 * @param ch Channel.
1852 * @param msg Message.
1853 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1854 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1855 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1856 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1859 GMCH_handle_ack (struct MeshChannel *ch,
1860 const struct GNUNET_MESH_ChannelManage *msg,
1863 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1864 if (GNUNET_SYSERR == fwd)
1866 if (is_loopback (ch))
1868 /* It is a loopback channel after all... */
1872 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1875 channel_confirm (ch, !fwd);
1880 * Handler for channel destroy messages.
1882 * @param ch Channel to be destroyed of.
1883 * @param msg Message.
1884 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1885 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1886 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1887 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1890 GMCH_handle_destroy (struct MeshChannel *ch,
1891 const struct GNUNET_MESH_ChannelManage *msg,
1894 struct MeshTunnel3 *t;
1896 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1897 if (GNUNET_SYSERR == fwd)
1899 if (is_loopback (ch))
1901 /* It is a loopback channel after all... */
1905 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1909 if ( (fwd && NULL == ch->dest) || (!fwd && NULL == ch->root) )
1911 /* Not for us (don't destroy twice a half-open loopback channel) */
1916 GMCH_send_destroy (ch);
1917 channel_destroy (ch);
1918 GMT_destroy_if_empty (t);
1923 * Sends an already built message on a channel.
1925 * If the channel is on a loopback tunnel, notifies the appropriate destination
1928 * On a normal channel passes the message to the tunnel for encryption and
1929 * sending on a connection.
1931 * This function DOES NOT save the message for retransmission.
1933 * @param message Message to send. Function makes a copy of it.
1934 * @param ch Channel on which this message is transmitted.
1935 * @param fwd Is this a fwd message?
1938 GMCH_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1939 struct MeshChannel *ch, int fwd)
1941 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMCH Send %s %s on channel %s\n",
1942 fwd ? "FWD" : "BCK", GNUNET_MESH_DEBUG_M2S (ntohs (message->type)),
1945 if (GMT_is_loopback (ch->t))
1947 handle_loopback (ch, message, fwd);
1951 GMT_send_prebuilt_message (message, ch->t, ch, fwd);
1956 * Get the static string for identification of the channel.
1958 * @param ch Channel.
1960 * @return Static string with the channel IDs.
1963 GMCH_2s (const struct MeshChannel *ch)
1965 static char buf[64];
1968 return "(NULL Channel)";
1970 sprintf (buf, "%s:%X (%X / %X)",
1971 GMT_2s (ch->t), ch->gid, ch->lid_root, ch->lid_dest);