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 (GM_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 GM_f2s (fwd), 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 * Notify a client that the channel is no longer valid.
509 * @param ch Channel that is destroyed.
510 * @param local_only Should we try to send it to other peers?
513 send_destroy (struct MeshChannel *ch, int local_only)
515 struct GNUNET_MESH_ChannelManage msg;
517 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY);
518 msg.header.size = htons (sizeof (msg));
519 msg.chid = htonl (ch->gid);
521 /* If root is not NULL, notify.
522 * If it's NULL, check lid_root. When a local destroy comes in, root
523 * is set to NULL but lid_root is left untouched. In this case, do nothing,
524 * the client is the one who reuqested the channel to be destroyed.
526 if (NULL != ch->root)
527 GML_send_channel_destroy (ch->root, ch->lid_root);
528 else if (0 == ch->lid_root && GNUNET_NO == local_only)
529 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_NO, GNUNET_NO);
531 if (NULL != ch->dest)
532 GML_send_channel_destroy (ch->dest, ch->lid_dest);
533 else if (0 == ch->lid_dest && GNUNET_NO == local_only)
534 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_YES, GNUNET_NO);
539 * Destroy all reliable messages queued for a channel,
540 * during a channel destruction.
541 * Frees the reliability structure itself.
543 * @param rel Reliability data for a channel.
546 channel_rel_free_all (struct MeshChannelReliability *rel)
548 struct MeshReliableMessage *copy;
549 struct MeshReliableMessage *next;
554 for (copy = rel->head_recv; NULL != copy; copy = next)
557 GNUNET_CONTAINER_DLL_remove (rel->head_recv, rel->tail_recv, copy);
560 for (copy = rel->head_sent; NULL != copy; copy = next)
563 GNUNET_CONTAINER_DLL_remove (rel->head_sent, rel->tail_sent, copy);
566 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
567 GNUNET_SCHEDULER_cancel (rel->retry_task);
573 * Mark future messages as ACK'd.
575 * @param rel Reliability data.
576 * @param msg DataACK message with a bitfield of future ACK'd messages.
579 channel_rel_free_sent (struct MeshChannelReliability *rel,
580 const struct GNUNET_MESH_DataACK *msg)
582 struct MeshReliableMessage *copy;
583 struct MeshReliableMessage *next;
590 bitfield = msg->futures;
591 mid = ntohl (msg->mid);
592 LOG (GNUNET_ERROR_TYPE_DEBUG,
593 "!!! free_sent_reliable %u %llX\n",
595 LOG (GNUNET_ERROR_TYPE_DEBUG,
596 " rel %p, head %p\n",
597 rel, rel->head_sent);
598 for (i = 0, copy = rel->head_sent;
599 i < 64 && NULL != copy && 0 != bitfield;
602 LOG (GNUNET_ERROR_TYPE_DEBUG,
603 " trying bit %u (mid %u)\n",
606 if (0 == (bitfield & mask))
609 LOG (GNUNET_ERROR_TYPE_DEBUG, " set!\n");
610 /* Bit was set, clear the bit from the bitfield */
613 /* The i-th bit was set. Do we have that copy? */
614 /* Skip copies with mid < target */
615 target = mid + i + 1;
616 LOG (GNUNET_ERROR_TYPE_DEBUG, " target %u\n", target);
617 while (NULL != copy && GM_is_pid_bigger (target, copy->mid))
620 /* Did we run out of copies? (previously freed, it's ok) */
623 LOG (GNUNET_ERROR_TYPE_DEBUG, "run out of copies...\n");
627 /* Did we overshoot the target? (previously freed, it's ok) */
628 if (GM_is_pid_bigger (copy->mid, target))
630 LOG (GNUNET_ERROR_TYPE_DEBUG, " next copy %u\n", copy->mid);
634 /* Now copy->mid == target, free it */
636 rel_message_free (copy, GNUNET_YES);
639 LOG (GNUNET_ERROR_TYPE_DEBUG, "free_sent_reliable END\n");
644 * We haven't received an ACK after a certain time: restransmit the message.
646 * @param cls Closure (MeshReliableMessage with the message to restransmit)
647 * @param tc TaskContext.
650 channel_retransmit_message (void *cls,
651 const struct GNUNET_SCHEDULER_TaskContext *tc)
653 struct MeshChannelReliability *rel = cls;
654 struct MeshReliableMessage *copy;
655 struct MeshChannel *ch;
656 struct GNUNET_MESH_Data *payload;
659 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
660 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
664 copy = rel->head_sent;
671 payload = (struct GNUNET_MESH_Data *) ©[1];
672 fwd = (rel == ch->root_rel);
674 /* Message not found in the queue that we are going to use. */
675 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RETRANSMIT %u\n", copy->mid);
677 GMCH_send_prebuilt_message (&payload->header, ch, fwd, GNUNET_YES);
678 GNUNET_STATISTICS_update (stats, "# data retransmitted", 1, GNUNET_NO);
680 copy->timestamp = GNUNET_TIME_absolute_get();
681 rel->retry_timer = GNUNET_TIME_STD_BACKOFF (rel->retry_timer);
682 rel->retry_task = GNUNET_SCHEDULER_add_delayed (rel->retry_timer,
683 &channel_retransmit_message,
689 * Destroy a reliable message after it has been acknowledged, either by
690 * direct mid ACK or bitfield. Updates the appropriate data structures and
691 * timers and frees all memory.
693 * @param copy Message that is no longer needed: remote peer got it.
694 * @param update_time Is the timing information relevant?
695 * If this message is ACK in a batch the timing information
696 * is skewed by the retransmission, count only for the
697 * retransmitted message.
700 rel_message_free (struct MeshReliableMessage *copy, int update_time)
702 struct MeshChannelReliability *rel;
703 struct GNUNET_TIME_Relative time;
706 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Freeing %u\n", copy->mid);
709 time = GNUNET_TIME_absolute_get_duration (copy->timestamp);
710 rel->expected_delay.rel_value_us *= 7;
711 rel->expected_delay.rel_value_us += time.rel_value_us;
712 rel->expected_delay.rel_value_us /= 8;
713 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! took %s\n",
714 GNUNET_STRINGS_relative_time_to_string (time, GNUNET_NO));
715 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! new expected delay %s\n",
716 GNUNET_STRINGS_relative_time_to_string (rel->expected_delay,
718 rel->retry_timer = rel->expected_delay;
722 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! batch free, ignoring timing\n");
724 GNUNET_CONTAINER_DLL_remove (rel->head_sent, rel->tail_sent, copy);
730 * Confirm we got a channel create.
732 * @param ch The channel to confirm.
733 * @param fwd Should we send a FWD ACK? (going dest->root)
736 channel_send_ack (struct MeshChannel *ch, int fwd)
738 struct GNUNET_MESH_ChannelManage msg;
740 msg.header.size = htons (sizeof (msg));
741 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK);
742 LOG (GNUNET_ERROR_TYPE_DEBUG,
743 " sending channel %s ack for channel %s\n",
744 GM_f2s (fwd), GMCH_2s (ch));
746 msg.chid = htonl (ch->gid);
747 GMCH_send_prebuilt_message (&msg.header, ch, !fwd, GNUNET_NO);
752 * Notify that a channel create didn't succeed.
754 * @param ch The channel to reject.
757 channel_send_nack (struct MeshChannel *ch)
759 struct GNUNET_MESH_ChannelManage msg;
761 msg.header.size = htons (sizeof (msg));
762 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_NACK);
763 LOG (GNUNET_ERROR_TYPE_DEBUG,
764 " sending channel NACK for channel %s\n",
767 msg.chid = htonl (ch->gid);
768 GMCH_send_prebuilt_message (&msg.header, ch, GNUNET_NO, GNUNET_NO);
773 * Channel was ACK'd by remote peer, mark as ready and cancel retransmission.
775 * @param ch Channel to mark as ready.
776 * @param fwd Was the ACK message a FWD ACK? (dest->root, SYNACK)
779 channel_confirm (struct MeshChannel *ch, int fwd)
781 struct MeshChannelReliability *rel;
782 struct MeshReliableMessage *copy;
783 struct MeshReliableMessage *next;
785 LOG (GNUNET_ERROR_TYPE_DEBUG,
786 " channel confirm %s %s:%X\n",
787 GM_f2s (fwd), GMT_2s (ch->t), ch->gid);
788 ch->state = MESH_CHANNEL_READY;
790 rel = fwd ? ch->root_rel : ch->dest_rel;
791 rel->client_ready = GNUNET_YES;
792 for (copy = rel->head_sent; NULL != copy; copy = next)
794 struct GNUNET_MessageHeader *msg;
797 msg = (struct GNUNET_MessageHeader *) ©[1];
798 if (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE)
800 rel_message_free (copy, GNUNET_YES);
804 send_client_ack (ch, fwd);
806 /* In case of a FWD ACK (SYNACK) send a BCK ACK (ACK). */
808 channel_send_ack (ch, !fwd);
813 * Message has been sent: start retransmission timer.
815 * @param cls Closure (copy sent).
817 * @param q Queue handler (no longer valid).
818 * @param type Type of message.
819 * @param size Size of the message.
822 message_sent (void *cls,
823 struct MeshTunnel3 *t,
824 struct MeshTunnel3Queue *q,
825 uint16_t type, size_t size)
827 struct MeshReliableMessage *copy = cls;
828 struct MeshChannelReliability *rel = copy->rel;
830 copy->timestamp = GNUNET_TIME_absolute_get ();
831 if (GNUNET_SCHEDULER_NO_TASK == rel->retry_task)
834 GNUNET_TIME_relative_multiply (rel->expected_delay,
835 MESH_RETRANSMIT_MARGIN);
837 GNUNET_SCHEDULER_add_delayed (rel->retry_timer,
838 &channel_retransmit_message,
845 * Save a copy to retransmit in case it gets lost.
847 * Initializes all needed callbacks and timers.
849 * @param ch Channel this message goes on.
850 * @param msg Message to copy.
851 * @param fwd Is this fwd traffic?
853 static struct MeshReliableMessage *
854 channel_save_copy (struct MeshChannel *ch,
855 const struct GNUNET_MessageHeader *msg,
858 struct MeshChannelReliability *rel;
859 struct MeshReliableMessage *copy;
864 rel = fwd ? ch->root_rel : ch->dest_rel;
865 mid = rel->mid_send - 1;
866 type = ntohs (msg->type);
867 size = ntohs (msg->size);
869 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! SAVE %u %s\n",
871 copy = GNUNET_malloc (sizeof (struct MeshReliableMessage) + size);
875 memcpy (©[1], msg, size);
876 GNUNET_CONTAINER_DLL_insert_tail (rel->head_sent, rel->tail_sent, copy);
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 GM_f2s (fwd), GM_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 /******************************************************************************/
1007 * Destroy a channel and free all resources.
1009 * @param ch Channel to destroy.
1012 GMCH_destroy (struct MeshChannel *ch)
1014 struct MeshClient *c;
1019 LOG (GNUNET_ERROR_TYPE_DEBUG, "destroying channel %s:%u\n",
1020 GMT_2s (ch->t), ch->gid);
1026 GML_channel_remove (c, ch->lid_root, ch);
1032 GML_channel_remove (c, ch->lid_dest, ch);
1035 channel_rel_free_all (ch->root_rel);
1036 channel_rel_free_all (ch->dest_rel);
1038 GMT_remove_channel (ch->t, ch);
1039 GNUNET_STATISTICS_update (stats, "# channels", -1, GNUNET_NO);
1048 * @param ch Channel.
1053 GMCH_get_id (const struct MeshChannel *ch)
1060 * Get the channel tunnel.
1062 * @param ch Channel to get the tunnel from.
1064 * @return tunnel of the channel.
1066 struct MeshTunnel3 *
1067 GMCH_get_tunnel (const struct MeshChannel *ch)
1074 * Get free buffer space towards the client on a specific channel.
1076 * @param ch Channel.
1077 * @param fwd Is query about FWD traffic?
1079 * @return Free buffer space [0 - 64]
1082 GMCH_get_buffer (struct MeshChannel *ch, int fwd)
1084 struct MeshChannelReliability *rel;
1086 rel = fwd ? ch->dest_rel : ch->root_rel;
1088 /* If rel is NULL it means that the end is not yet created,
1089 * most probably is a loopback channel at the point of sending
1090 * the ChannelCreate to itself.
1095 return (64 - rel->n_recv);
1100 * Get flow control status of end point: is client allow to send?
1102 * @param ch Channel.
1103 * @param fwd Is query about FWD traffic? (Request root status).
1105 * @return #GNUNET_YES if client is allowed to send us data.
1108 GMCH_get_allowed (struct MeshChannel *ch, int fwd)
1110 struct MeshChannelReliability *rel;
1112 rel = fwd ? ch->root_rel : ch->dest_rel;
1114 return rel->client_allowed;
1119 * Is the root client for this channel on this peer?
1121 * @param ch Channel.
1122 * @param fwd Is this for fwd traffic?
1124 * @return #GNUNET_YES in case it is.
1127 GMCH_is_origin (struct MeshChannel *ch, int fwd)
1129 struct MeshClient *c;
1131 c = fwd ? ch->root : ch->dest;
1137 * Is the destination client for this channel on this peer?
1139 * @param ch Channel.
1140 * @param fwd Is this for fwd traffic?
1142 * @return #GNUNET_YES in case it is.
1145 GMCH_is_terminal (struct MeshChannel *ch, int fwd)
1147 struct MeshClient *c;
1149 c = fwd ? ch->dest : ch->root;
1155 * Notify the destination client that a new incoming channel was created.
1157 * @param ch Channel that was created.
1160 GMCH_send_create (struct MeshChannel *ch)
1164 if (NULL == ch->dest)
1168 opt |= GNUNET_YES == ch->reliable ? GNUNET_MESH_OPTION_RELIABLE : 0;
1169 opt |= GNUNET_YES == ch->nobuffer ? GNUNET_MESH_OPTION_NOBUFFER : 0;
1170 GML_send_channel_create (ch->dest, ch->lid_dest, ch->port, opt,
1171 GMT_get_destination (ch->t));
1177 * Send an end-to-end ACK message for the most recent in-sequence payload.
1179 * If channel is not reliable, do nothing.
1181 * @param ch Channel this is about.
1182 * @param fwd Is for FWD traffic? (ACK dest->owner)
1185 GMCH_send_data_ack (struct MeshChannel *ch, int fwd)
1187 struct GNUNET_MESH_DataACK msg;
1188 struct MeshChannelReliability *rel;
1189 struct MeshReliableMessage *copy;
1194 if (GNUNET_NO == ch->reliable)
1198 rel = fwd ? ch->dest_rel : ch->root_rel;
1199 ack = rel->mid_recv - 1;
1200 LOG (GNUNET_ERROR_TYPE_DEBUG,
1201 " !! Send DATA_ACK for %u\n",
1204 msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_DATA_ACK);
1205 msg.header.size = htons (sizeof (msg));
1206 msg.chid = htonl (ch->gid);
1208 for (copy = rel->head_recv; NULL != copy; copy = copy->next)
1210 if (copy->type != GNUNET_MESSAGE_TYPE_MESH_DATA)
1212 LOG (GNUNET_ERROR_TYPE_DEBUG,
1213 "!! Type %s, expected DATA\n",
1214 GM_m2s (copy->type));
1217 if (copy->mid == ack + 1)
1222 delta = copy->mid - (ack + 1);
1225 mask = 0x1LL << delta;
1226 msg.futures |= mask;
1227 LOG (GNUNET_ERROR_TYPE_DEBUG,
1228 " !! setting bit for %u (delta %u) (%llX) -> %llX\n",
1229 copy->mid, delta, mask, msg.futures);
1231 msg.mid = htonl (ack);
1232 LOG (GNUNET_ERROR_TYPE_DEBUG,
1233 "!!! ACK for %u, futures %llX\n",
1236 GMCH_send_prebuilt_message (&msg.header, ch, !fwd, GNUNET_NO);
1237 LOG (GNUNET_ERROR_TYPE_DEBUG, "send_data_ack END\n");
1242 * Allow a client to send us more data, in case it was choked.
1244 * @param ch Channel.
1245 * @param fwd Is this about FWD traffic? (Root client).
1248 GMCH_allow_client (struct MeshChannel *ch, int fwd)
1250 struct MeshChannelReliability *rel;
1251 unsigned int buffer;
1253 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMCH allow\n");
1255 if (MESH_CHANNEL_READY != ch->state)
1257 LOG (GNUNET_ERROR_TYPE_DEBUG, " channel not ready yet!\n");
1261 if (GNUNET_YES == ch->reliable)
1263 rel = fwd ? ch->root_rel : ch->dest_rel;
1269 if (NULL != rel->head_sent && 64 <= rel->mid_send - rel->head_sent->mid)
1271 LOG (GNUNET_ERROR_TYPE_DEBUG, " too big MID gap! Wait for ACK.\n");
1276 if (is_loopback (ch))
1277 buffer = GMCH_get_buffer (ch, fwd);
1279 buffer = GMT_get_connections_buffer (ch->t);
1283 LOG (GNUNET_ERROR_TYPE_DEBUG, " no buffer space.\n");
1287 LOG (GNUNET_ERROR_TYPE_DEBUG, " buffer space %u, allowing\n", buffer);
1288 send_client_ack (ch, fwd);
1295 * @param ch Channel.
1298 GMCH_debug (struct MeshChannel *ch)
1302 LOG (GNUNET_ERROR_TYPE_DEBUG, "*** DEBUG NULL CHANNEL ***\n");
1305 LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %s:%X (%p)\n",
1306 GMT_2s (ch->t), ch->gid, ch);
1307 LOG (GNUNET_ERROR_TYPE_DEBUG, " root %p/%p\n",
1308 ch->root, ch->root_rel);
1309 if (NULL != ch->root)
1311 LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->root));
1312 LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n",
1313 ch->root_rel->client_ready ? "YES" : "NO");
1314 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_root);
1316 LOG (GNUNET_ERROR_TYPE_DEBUG, " dest %p/%p\n",
1317 ch->dest, ch->dest_rel);
1318 if (NULL != ch->dest)
1320 LOG (GNUNET_ERROR_TYPE_DEBUG, " cli %s\n", GML_2s (ch->dest));
1321 LOG (GNUNET_ERROR_TYPE_DEBUG, " ready %s\n",
1322 ch->dest_rel->client_ready ? "YES" : "NO");
1323 LOG (GNUNET_ERROR_TYPE_DEBUG, " id %X\n", ch->lid_dest);
1329 * Handle an ACK given by a client.
1331 * Mark client as ready and send him any buffered data we could have for him.
1333 * @param ch Channel.
1334 * @param fwd Is this a "FWD ACK"? (FWD ACKs are sent by dest and go BCK)
1337 GMCH_handle_local_ack (struct MeshChannel *ch, int fwd)
1339 struct MeshChannelReliability *rel;
1340 struct MeshClient *c;
1342 rel = fwd ? ch->dest_rel : ch->root_rel;
1343 c = fwd ? ch->dest : ch->root;
1345 rel->client_ready = GNUNET_YES;
1346 send_client_buffered_data (ch, c, fwd);
1347 if (is_loopback (ch))
1349 unsigned int buffer;
1351 buffer = GMCH_get_buffer (ch, fwd);
1353 GMCH_allow_client (ch, fwd);
1357 GMT_send_connection_acks (ch->t);
1362 * Handle data given by a client.
1364 * Check whether the client is allowed to send in this tunnel, save if channel
1365 * is reliable and send an ACK to the client if there is still buffer space
1368 * @param ch Channel.
1369 * @param c Client which sent the data.
1370 * @param message Message.
1371 * @param fwd Is this a FWD data?
1373 * @return GNUNET_OK if everything goes well, GNUNET_SYSERR in case of en error.
1376 GMCH_handle_local_data (struct MeshChannel *ch,
1377 struct MeshClient *c,
1378 struct GNUNET_MessageHeader *message,
1381 struct MeshChannelReliability *rel;
1382 struct GNUNET_MESH_Data *payload;
1383 size_t size = ntohs (message->size);
1384 uint16_t p2p_size = sizeof(struct GNUNET_MESH_Data) + size;
1385 unsigned char cbuf[p2p_size];
1387 /* Is the client in the channel? */
1394 GNUNET_break_op (0);
1395 return GNUNET_SYSERR;
1398 rel = fwd ? ch->root_rel : ch->dest_rel;
1400 if (GNUNET_NO == rel->client_allowed)
1402 GNUNET_break_op (0);
1403 return GNUNET_SYSERR;
1406 rel->client_allowed = GNUNET_NO;
1408 /* Ok, everything is correct, send the message. */
1409 payload = (struct GNUNET_MESH_Data *) cbuf;
1410 payload->mid = htonl (rel->mid_send);
1412 memcpy (&payload[1], message, size);
1413 payload->header.size = htons (p2p_size);
1414 payload->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_DATA);
1415 payload->chid = htonl (ch->gid);
1416 LOG (GNUNET_ERROR_TYPE_DEBUG, " sending on channel...\n");
1417 GMCH_send_prebuilt_message (&payload->header, ch, fwd, GNUNET_NO);
1419 if (is_loopback (ch))
1421 if (GMCH_get_buffer (ch, fwd) > 0)
1422 send_client_ack (ch, fwd);
1427 if (GMT_get_connections_buffer (ch->t) > 0)
1429 send_client_ack (ch, fwd);
1437 * Handle a channel destroy requested by a client.
1439 * Destroy the channel and the tunnel in case this was the last channel.
1441 * @param ch Channel.
1442 * @param c Client that requested the destruction (to avoid notifying him).
1443 * @param is_root Is the request coming from root?
1446 GMCH_handle_local_destroy (struct MeshChannel *ch,
1447 struct MeshClient *c,
1450 struct MeshTunnel3 *t;
1452 /* Cleanup after the tunnel */
1453 if (GNUNET_NO == is_root && c == ch->dest)
1455 LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is destination.\n", GML_2s (c));
1456 GML_client_delete_channel (c, ch, ch->lid_dest);
1459 if (GNUNET_YES == is_root && c == ch->root)
1461 LOG (GNUNET_ERROR_TYPE_DEBUG, " Client %s is owner.\n", GML_2s (c));
1462 GML_client_delete_channel (c, ch, ch->lid_root);
1467 send_destroy (ch, GNUNET_NO);
1469 GMT_destroy_if_empty (t);
1474 * Handle a channel create requested by a client.
1476 * Create the channel and the tunnel in case this was the first0 channel.
1478 * @param c Client that requested the creation (will be the root).
1479 * @param msg Create Channel message.
1481 * @return GNUNET_OK if everything went fine, GNUNET_SYSERR otherwise.
1484 GMCH_handle_local_create (struct MeshClient *c,
1485 struct GNUNET_MESH_ChannelMessage *msg)
1487 struct MeshChannel *ch;
1488 struct MeshTunnel3 *t;
1489 struct MeshPeer *peer;
1490 MESH_ChannelNumber chid;
1492 LOG (GNUNET_ERROR_TYPE_DEBUG, " towards %s:%u\n",
1493 GNUNET_i2s (&msg->peer), ntohl (msg->port));
1494 chid = ntohl (msg->channel_id);
1496 /* Sanity check for duplicate channel IDs */
1497 if (NULL != GML_channel_get (c, chid))
1500 return GNUNET_SYSERR;
1503 peer = GMP_get (&msg->peer);
1504 GMP_add_tunnel (peer);
1505 t = GMP_get_tunnel (peer);
1507 if (GMP_get_short_id (peer) == myid)
1509 GMT_change_cstate (t, MESH_TUNNEL3_READY);
1516 /* Create channel */
1517 ch = channel_new (t, c, chid);
1521 return GNUNET_SYSERR;
1523 ch->port = ntohl (msg->port);
1524 channel_set_options (ch, ntohl (msg->opt));
1526 /* In unreliable channels, we'll use the DLL to buffer BCK data */
1527 ch->root_rel = GNUNET_new (struct MeshChannelReliability);
1528 ch->root_rel->ch = ch;
1529 ch->root_rel->expected_delay = MESH_RETRANSMIT_TIME;
1531 LOG (GNUNET_ERROR_TYPE_DEBUG, "CREATED CHANNEL %s\n", GMCH_2s (ch));
1533 /* Send create channel */
1535 struct GNUNET_MESH_ChannelCreate msgcc;
1537 msgcc.header.size = htons (sizeof (msgcc));
1538 msgcc.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE);
1539 msgcc.chid = htonl (ch->gid);
1540 msgcc.port = msg->port;
1541 msgcc.opt = msg->opt;
1543 GMT_send_prebuilt_message (&msgcc.header, t, ch, GNUNET_YES, NULL, NULL);
1550 * Handler for mesh network payload traffic.
1552 * @param ch Channel for the message.
1553 * @param msg Unencryted data message.
1554 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1555 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1556 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1557 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1560 GMCH_handle_data (struct MeshChannel *ch,
1561 const struct GNUNET_MESH_Data *msg,
1564 struct MeshChannelReliability *rel;
1565 struct MeshClient *c;
1568 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1569 if (GNUNET_SYSERR == fwd)
1571 if (is_loopback (ch))
1573 /* It is a loopback channel after all... */
1577 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1580 /* Initialize FWD/BCK data */
1581 c = fwd ? ch->dest : ch->root;
1582 rel = fwd ? ch->dest_rel : ch->root_rel;
1590 GNUNET_STATISTICS_update (stats, "# data received", 1, GNUNET_NO);
1592 mid = ntohl (msg->mid);
1593 LOG (GNUNET_ERROR_TYPE_DEBUG, "!! got mid %u\n", mid);
1595 if (GNUNET_NO == ch->reliable ||
1596 ( !GM_is_pid_bigger (rel->mid_recv, mid) &&
1597 GM_is_pid_bigger (rel->mid_recv + 64, mid) ) )
1599 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! RECV %u\n", mid);
1600 if (GNUNET_YES == ch->reliable)
1602 /* Is this the exact next expected messasge? */
1603 if (mid == rel->mid_recv)
1605 LOG (GNUNET_ERROR_TYPE_DEBUG, "as expected\n");
1607 send_client_data (ch, msg, fwd);
1611 LOG (GNUNET_ERROR_TYPE_DEBUG, "save for later\n");
1612 add_buffered_data (msg, rel);
1617 /* Tunnel is unreliable: send to clients directly */
1618 /* FIXME: accept Out Of Order traffic */
1619 rel->mid_recv = mid + 1;
1620 send_client_data (ch, msg, fwd);
1625 GNUNET_break_op (0);
1626 LOG (GNUNET_ERROR_TYPE_DEBUG,
1627 " MID %u not expected (%u - %u), dropping!\n",
1628 mid, rel->mid_recv, rel->mid_recv + 63);
1631 GMCH_send_data_ack (ch, fwd);
1636 * Handler for mesh network traffic end-to-end ACKs.
1638 * @param ch Channel on which we got this message.
1639 * @param msg Data message.
1640 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1641 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1642 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1643 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1646 GMCH_handle_data_ack (struct MeshChannel *ch,
1647 const struct GNUNET_MESH_DataACK *msg,
1650 struct MeshChannelReliability *rel;
1651 struct MeshReliableMessage *copy;
1652 struct MeshReliableMessage *next;
1656 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1657 if (GNUNET_SYSERR == fwd)
1659 if (is_loopback (ch))
1661 /* It is a loopback channel after all... */
1665 /* Inverted: if message came 'FWD' is a 'BCK ACK'. */
1666 fwd = (NULL != ch->dest) ? GNUNET_NO : GNUNET_YES;
1669 ack = ntohl (msg->mid);
1670 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! %s ACK %u\n",
1671 (GNUNET_YES == fwd) ? "FWD" : "BCK", ack);
1673 if (GNUNET_YES == fwd)
1683 GNUNET_break_op (0);
1687 /* Free ACK'd copies: no need to retransmit those anymore */
1688 for (work = GNUNET_NO, copy = rel->head_sent; copy != NULL; copy = next)
1690 if (GM_is_pid_bigger (copy->mid, ack))
1692 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! head %u, out!\n", copy->mid);
1693 channel_rel_free_sent (rel, msg);
1697 LOG (GNUNET_ERROR_TYPE_DEBUG, " !! id %u\n", copy->mid);
1699 rel_message_free (copy, GNUNET_YES);
1702 /* ACK client if needed */
1703 GMCH_allow_client (ch, fwd);
1705 /* If some message was free'd, update the retransmission delay */
1706 if (GNUNET_YES == work)
1708 if (GNUNET_SCHEDULER_NO_TASK != rel->retry_task)
1710 GNUNET_SCHEDULER_cancel (rel->retry_task);
1711 if (NULL == rel->head_sent)
1713 rel->retry_task = GNUNET_SCHEDULER_NO_TASK;
1717 struct GNUNET_TIME_Absolute new_target;
1718 struct GNUNET_TIME_Relative delay;
1720 delay = GNUNET_TIME_relative_multiply (rel->retry_timer,
1721 MESH_RETRANSMIT_MARGIN);
1722 new_target = GNUNET_TIME_absolute_add (rel->head_sent->timestamp,
1724 delay = GNUNET_TIME_absolute_get_remaining (new_target);
1726 GNUNET_SCHEDULER_add_delayed (delay,
1727 &channel_retransmit_message,
1738 * Handler for channel create messages.
1740 * Does not have fwd parameter because it's always 'FWD': channel is incoming.
1742 * @param t Tunnel this channel will be in.
1743 * @param msg Channel crate message.
1745 struct MeshChannel *
1746 GMCH_handle_create (struct MeshTunnel3 *t,
1747 const struct GNUNET_MESH_ChannelCreate *msg)
1749 MESH_ChannelNumber chid;
1750 struct MeshChannel *ch;
1751 struct MeshClient *c;
1753 chid = ntohl (msg->chid);
1755 ch = GMT_get_channel (t, chid);
1758 /* Create channel */
1759 ch = channel_new (t, NULL, 0);
1762 channel_set_options (ch, ntohl (msg->opt));
1764 /* Find a destination client */
1765 ch->port = ntohl (msg->port);
1766 LOG (GNUNET_ERROR_TYPE_DEBUG, " port %u\n", ch->port);
1767 c = GML_client_get_by_port (ch->port);
1770 /* TODO send reject */
1771 LOG (GNUNET_ERROR_TYPE_DEBUG, " no client has port registered\n");
1772 if (is_loopback (ch))
1774 LOG (GNUNET_ERROR_TYPE_DEBUG, " loopback: destroy on handler\n");
1775 channel_send_nack (ch);
1779 LOG (GNUNET_ERROR_TYPE_DEBUG, " not loopback: destroy now\n");
1780 channel_send_nack (ch);
1787 LOG (GNUNET_ERROR_TYPE_DEBUG, " client %p has port registered\n", c);
1790 add_destination (ch, c);
1791 if (GNUNET_YES == ch->reliable)
1792 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Reliable\n");
1794 LOG (GNUNET_ERROR_TYPE_DEBUG, "!!! Not Reliable\n");
1796 GMCH_send_create (ch);
1797 channel_send_ack (ch, GNUNET_YES);
1804 * Handler for channel NACK messages.
1806 * NACK messages always go dest -> root, no need for 'fwd' or 'msg' parameter.
1808 * @param ch Channel.
1811 GMCH_handle_nack (struct MeshChannel *ch)
1813 send_client_nack (ch);
1819 * Handler for channel ack messages.
1821 * @param ch Channel.
1822 * @param msg Message.
1823 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1824 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1825 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1826 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1829 GMCH_handle_ack (struct MeshChannel *ch,
1830 const struct GNUNET_MESH_ChannelManage *msg,
1833 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1834 if (GNUNET_SYSERR == fwd)
1836 if (is_loopback (ch))
1838 /* It is a loopback channel after all... */
1842 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1845 channel_confirm (ch, !fwd);
1850 * Handler for channel destroy messages.
1852 * @param ch Channel to be destroyed of.
1853 * @param msg Message.
1854 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
1855 * #GNUNET_YES if message is FWD on the respective channel (loopback)
1856 * #GNUNET_NO if message is BCK on the respective channel (loopback)
1857 * #GNUNET_SYSERR if message on a one-ended channel (remote)
1860 GMCH_handle_destroy (struct MeshChannel *ch,
1861 const struct GNUNET_MESH_ChannelManage *msg,
1864 struct MeshTunnel3 *t;
1866 /* If this is a remote (non-loopback) channel, find 'fwd'. */
1867 if (GNUNET_SYSERR == fwd)
1869 if (is_loopback (ch))
1871 /* It is a loopback channel after all... */
1875 fwd = (NULL != ch->dest) ? GNUNET_YES : GNUNET_NO;
1879 if ( (fwd && NULL == ch->dest) || (!fwd && NULL == ch->root) )
1881 /* Not for us (don't destroy twice a half-open loopback channel) */
1886 send_destroy (ch, GNUNET_YES);
1888 GMT_destroy_if_empty (t);
1893 * Sends an already built message on a channel.
1895 * If the channel is on a loopback tunnel, notifies the appropriate destination
1898 * On a normal channel passes the message to the tunnel for encryption and
1899 * sending on a connection.
1901 * This function DOES NOT save the message for retransmission.
1903 * @param message Message to send. Function makes a copy of it.
1904 * @param ch Channel on which this message is transmitted.
1905 * @param fwd Is this a fwd message?
1906 * @param retransmission Is this a retransmission? (Don't save a copy)
1909 GMCH_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
1910 struct MeshChannel *ch, int fwd,
1913 LOG (GNUNET_ERROR_TYPE_DEBUG, "GMCH Send %s %s on channel %s\n",
1914 GM_f2s (fwd), GM_m2s (ntohs (message->type)),
1917 if (GMT_is_loopback (ch->t))
1919 handle_loopback (ch, message, fwd);
1923 if (GNUNET_YES == ch->reliable && GNUNET_NO == retransmission
1924 && ntohs (message->type) == GNUNET_MESSAGE_TYPE_MESH_DATA)
1926 struct MeshReliableMessage *copy;
1928 copy = channel_save_copy (ch, message, fwd);
1929 copy->q = GMT_send_prebuilt_message (message, ch->t, ch, fwd,
1930 &message_sent, copy);
1933 GMT_send_prebuilt_message (message, ch->t, ch, fwd, NULL, NULL);
1938 * Get the static string for identification of the channel.
1940 * @param ch Channel.
1942 * @return Static string with the channel IDs.
1945 GMCH_2s (const struct MeshChannel *ch)
1947 static char buf[64];
1950 return "(NULL Channel)";
1952 sprintf (buf, "%s:%u gid:%X (%X / %X)",
1953 GMT_2s (ch->t), ch->port, ch->gid, ch->lid_root, ch->lid_dest);